2024

Fate of antibiotics and hormones during hydrothermal carbonization of poultry litter: degradation kinetics and toxicity assessment of filtrates and hydrochars

Campagnano M, Xiao K, Gilboa Y, Cheruty U, Friedler E. Fate of antibiotics and hormones during hydrothermal carbonization of poultry litter: degradation kinetics and toxicity assessment of filtrates and hydrochars. Environmental Research. 2024 May 1;248:118168. https://doi.org/10.1016/j.envres.2024.118168
 

This study investigated degradation kinetics of five selected organic micropollutants (OMPs) present in poultry litter (namely: sulfadiazine, tetracycline, and doxycycline hyclate (antibiotics); estrone and 17-β-estradiol (hormones)) during hydrothermal carbonization (HTC) treatment as the temperature stepwise increased to 250 °C. All five pure OMPs were completely degraded before 250 °C was reached during the HTC process. Nevertheless, presence of poultry litter slowed down the degradation of OMPs. Through elemental mass balance calculation, it is noted that after 15 min (temperature less than 137 °C), 69–82% of organic carbon and 50–66% of organic nitrogen initially consisting part of the target antibiotics were fully mineralized. Both HTC filtrates and hydrochars obtained from poultry litter inhibited Escherichia coli and Bacillus subtilis growth. A combination of high salinity, high nutrients, dissolved organic carbon, and other ions in the filtrate as well as the adsorption of OMPs on hydrochars were probably the reason for the high toxicity.

@article{a62f293fe6034f099de818233768695f,
title = "Fate of antibiotics and hormones during hydrothermal carbonization of poultry litter: degradation kinetics and toxicity assessment of filtrates and hydrochars",
abstract = "This study investigated degradation kinetics of five selected organic micropollutants (OMPs) present in poultry litter (namely: sulfadiazine, tetracycline, and doxycycline hyclate (antibiotics); estrone and 17-β-estradiol (hormones)) during hydrothermal carbonization (HTC) treatment as the temperature stepwise increased to 250 °C. All five pure OMPs were completely degraded before 250 °C was reached during the HTC process. Nevertheless, presence of poultry litter slowed down the degradation of OMPs. Through elemental mass balance calculation, it is noted that after 15 min (temperature less than 137 °C), 69–82% of organic carbon and 50–66% of organic nitrogen initially consisting part of the target antibiotics were fully mineralized. Both HTC filtrates and hydrochars obtained from poultry litter inhibited Escherichia coli and Bacillus subtilis growth. A combination of high salinity, high nutrients, dissolved organic carbon, and other ions in the filtrate as well as the adsorption of OMPs on hydrochars were probably the reason for the high toxicity.",
keywords = "Antibiotics, Degradation kinetics, Elemental mass balance, Hormones, Organic micropollutants, Toxicity assessment",
author = "Micol Campagnano and Keke Xiao and Yael Gilboa and Uta Cheruty and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2024 Elsevier Inc.",
year = "2024",
month = may,
day = "1",
doi = "10.1016/j.envres.2024.118168",
language = "אנגלית",
volume = "248",
journal = "Environmental Research",
issn = "0013-9351",
publisher = "Academic Press Inc.",

}

A combined approach of electrodialysis pretreatment and vacuum UV for removing micropollutants from natural waters

Dubowski Y, Alfiya Y, Gilboa Y, Sabach S, Friedler E. A combined approach of electrodialysis pretreatment and vacuum UV for removing micropollutants from natural waters. Water Research. 2024 Mar 1;251:121152. https://doi.org/10.1016/j.watres.2024.121152
 

Advanced oxidation processes (AOPs) augment traditional water treatment methods, enhancing the removal of persistent contaminants. Efficiency of AOPs that utilize UV radiation for oxidants generation (e.g., ·OH) is reduced in water matrices that contain substants that may act as inner UV filters and/or scavengers for the generated radicals. Among such interfering compounds are major inorganic ions and dissolved organic matter that are naturally present in realistic waters. Thus, to improve AOPs efficiency it is desirable to separate the target pollutants from these natural species before treatment. Here the potential of electrodialysis as such pretreatment was investigated. The impact of this pretreatment on photo-oxidation of the pharmaceutical carbamazepine (CBZ) under VUV (λ<200 nm) irradiation, which yields ·OH generation via water homolysis, was tested in different water matrices. The obtained results indicate that in all tested solutions: Deionized water, groundwater, surface water, and treated wastewater, the addition of electrodialysis pretreatment successfully separated the target micropollutant CBZ from the major natural ions and to some extend the NOM, resulting faster degradation rates of CBZ and its transformation products in the following VUV-based AOP. Energy cost calculations indicated that addition of this pretreatment step reduces the overall energy demand of the system (i.e., energy consumption for the electrodialysis step was smaller than the energy gained by reducing the required VUV irradiation dose).

@article{1388242c87b84acbbe66428f85408bf6,
title = "A combined approach of electrodialysis pretreatment and vacuum UV for removing micropollutants from natural waters",
abstract = "Advanced oxidation processes (AOPs) augment traditional water treatment methods, enhancing the removal of persistent contaminants. Efficiency of AOPs that utilize UV radiation for oxidants generation (e.g., ·OH) is reduced in water matrices that contain substants that may act as inner UV filters and/or scavengers for the generated radicals. Among such interfering compounds are major inorganic ions and dissolved organic matter that are naturally present in realistic waters. Thus, to improve AOPs efficiency it is desirable to separate the target pollutants from these natural species before treatment. Here the potential of electrodialysis as such pretreatment was investigated. The impact of this pretreatment on photo-oxidation of the pharmaceutical carbamazepine (CBZ) under VUV (λ<200 nm) irradiation, which yields ·OH generation via water homolysis, was tested in different water matrices. The obtained results indicate that in all tested solutions: Deionized water, groundwater, surface water, and treated wastewater, the addition of electrodialysis pretreatment successfully separated the target micropollutant CBZ from the major natural ions and to some extend the NOM, resulting faster degradation rates of CBZ and its transformation products in the following VUV-based AOP. Energy cost calculations indicated that addition of this pretreatment step reduces the overall energy demand of the system (i.e., energy consumption for the electrodialysis step was smaller than the energy gained by reducing the required VUV irradiation dose).",
keywords = "Advanced Oxidation Processes (AOP), Carbamazepine, Electrodialysis, Micropollutants, Photochemistry, VUV",
author = "Yael Dubowski and Yuval Alfiya and Yael Gilboa and Sara Sabach and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2024 Elsevier Ltd",
year = "2024",
month = mar,
day = "1",
doi = "10.1016/j.watres.2024.121152",
language = "אנגלית",
volume = "251",
journal = "Water Research",
issn = "0043-1354",
publisher = "Elsevier Ltd.",

}

Evaluation of UVLED disinfection for biofouling control during distribution of wastewater effluent

Randall T, Shlomo I, Wells E, Real B, Ma B, Linden Y et al. Evaluation of UVLED disinfection for biofouling control during distribution of wastewater effluent. Water Reuse. 2024;14(1):80-94. https://doi.org/10.2166/wrd.2024.131
 

A commercially available UVLED flow-through device, operating at 40 mJ/cm2, was examined for biofilm control on irrigation pipe material fed by wastewater effluent. Biofouling was monitored through total coliform counts, crystal violet (CV) staining, and ATP analyses. A UV fluence of 40 mJ/cm2 at 280 nm retarded biofilm formation; however, complete biofilm prevention by UV treatment was not achieved despite a high inactivation of planktonic cells. After 5 days of the study, the total coliform and CV biofilm quantification assays between the UV-treated and control bioreactor coupons were not statistically different. The total coliform counts indicated a stable biofilm cell concentration was reached; the CV assay showed biofilm biomass accumulation with time. The ATP results revealed higher coupon ATP on the UV-treated coupons than the control coupons by day 5. The results provoke an interesting discussion surrounding the contribution of viable cells, represented by total coliforms, and extracellular polymeric substance (EPS) to total biofilm biomass. This study also highlighted a need for further investigation into the relationship between ATP responses and complex UV-stress responses of diverse microbial communities as opposed to pure bacteria cultures.

@article{a249567b0e164d84870a5557301e0dba,
title = "Evaluation of UVLED disinfection for biofouling control during distribution of wastewater effluent",
abstract = "A commercially available UVLED flow-through device, operating at 40 mJ/cm2, was examined for biofilm control on irrigation pipe material fed by wastewater effluent. Biofouling was monitored through total coliform counts, crystal violet (CV) staining, and ATP analyses. A UV fluence of 40 mJ/cm2 at 280 nm retarded biofilm formation; however, complete biofilm prevention by UV treatment was not achieved despite a high inactivation of planktonic cells. After 5 days of the study, the total coliform and CV biofilm quantification assays between the UV-treated and control bioreactor coupons were not statistically different. The total coliform counts indicated a stable biofilm cell concentration was reached; the CV assay showed biofilm biomass accumulation with time. The ATP results revealed higher coupon ATP on the UV-treated coupons than the control coupons by day 5. The results provoke an interesting discussion surrounding the contribution of viable cells, represented by total coliforms, and extracellular polymeric substance (EPS) to total biofilm biomass. This study also highlighted a need for further investigation into the relationship between ATP responses and complex UV-stress responses of diverse microbial communities as opposed to pure bacteria cultures.",
keywords = "biofilm, bioreactor, irrigation, reuse, UV, wastewater",
author = "Tara Randall and Inbar Shlomo and Emma Wells and Breanna Real and Ben Ma and Yarrow Linden and Jasmine Gamboa and Eran Friedler and Linden, {Karl G.}",
note = "Publisher Copyright: {\textcopyright} 2024 The Authors.",
year = "2024",
doi = "10.2166/wrd.2024.131",
language = "אנגלית",
volume = "14",
pages = "80--94",
journal = "Water Reuse",
issn = "2709-6092",
publisher = "IWA Publishing",
number = "1",

}

2023

Photodegradation of Carbamazepine and Acridine with 165-200 nm Radiation from a Microcavity-Plasma VUV Phosphor Lamp

Dubowski Y, Subburaj S, Alfiya Y, Eden JG, Park SJ, Barki D et al. Photodegradation of Carbamazepine and Acridine with 165-200 nm Radiation from a Microcavity-Plasma VUV Phosphor Lamp. ACS ES and T Water. 2023 Sep 8;3(9):2919-2926. https://doi.org/10.1021/acsestwater.3c00167
 

A longstanding obstacle to the application of vacuum ultraviolet (VUV) radiation for advanced water treatment is the absence of efficient, affordable, and powerful lamps. A custom Xe2 microcavity plasma (McP) lamp with an internal phosphor film, generating broadband emission in the 165-200 nm interval, is presented here as an optical source for the degradation of dissolved contaminants. The performance of this lamp was evaluated by comparing measured photodegradation rates for carbamazepine (CBZ, a model compound) with corresponding data obtained with a conventional 254/185 nm Hg lamp. While the oxidant production rate was lower for the McP lamp, it was found to be more effective in photodegrading CBZ for a given energy dosage absorbed by the water. The McP lamp also produced higher concentrations of the byproduct acridine (ARD) but normalization to effective fluence exposure reveals it produced and removed ARD more efficiently than did the Hg lamp. The flat form factor and ability to produce output powers >10 W from a 100 cm2 aperture make the McP lamp promising for photochemical water treatment. Although its emission spectrum is not currently optimized, the data indicate that the lamp spectrum can be engineered to efficiently photodegrade a wide range of challenging water pollutants.

@article{df29c5b1d7d5495094368f2da1144681,
title = "Photodegradation of Carbamazepine and Acridine with 165-200 nm Radiation from a Microcavity-Plasma VUV Phosphor Lamp",
abstract = "A longstanding obstacle to the application of vacuum ultraviolet (VUV) radiation for advanced water treatment is the absence of efficient, affordable, and powerful lamps. A custom Xe2 microcavity plasma (McP) lamp with an internal phosphor film, generating broadband emission in the 165-200 nm interval, is presented here as an optical source for the degradation of dissolved contaminants. The performance of this lamp was evaluated by comparing measured photodegradation rates for carbamazepine (CBZ, a model compound) with corresponding data obtained with a conventional 254/185 nm Hg lamp. While the oxidant production rate was lower for the McP lamp, it was found to be more effective in photodegrading CBZ for a given energy dosage absorbed by the water. The McP lamp also produced higher concentrations of the byproduct acridine (ARD) but normalization to effective fluence exposure reveals it produced and removed ARD more efficiently than did the Hg lamp. The flat form factor and ability to produce output powers >10 W from a 100 cm2 aperture make the McP lamp promising for photochemical water treatment. Although its emission spectrum is not currently optimized, the data indicate that the lamp spectrum can be engineered to efficiently photodegrade a wide range of challenging water pollutants.",
keywords = "VUV, advanced oxidation processes (AOPs), carbamazepine, microcavity plasma array lamps, micropollutants, photochemistry",
author = "Yael Dubowski and Suganya Subburaj and Yuval Alfiya and Eden, {J. Gary} and Park, {Sung Jin} and Debra Barki and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2023 American Chemical Society.",
year = "2023",
month = sep,
day = "8",
doi = "10.1021/acsestwater.3c00167",
language = "אנגלית",
volume = "3",
pages = "2919--2926",
journal = "ACS ES and T Water",
issn = "2690-0637",
publisher = "American Chemical Society",
number = "9",

}

Whole campus wastewater surveillance of SARS-CoV-2 for COVID-19 outbreak management

Sharaby Y, Gilboa Y, Alfiya Y, Sabach S, Cheruti U, Friedler E. Whole campus wastewater surveillance of SARS-CoV-2 for COVID-19 outbreak management. Water Science and Technology. 2023 Feb 15;87(4):910-923. https://doi.org/10.2166/wst.2023.030
 

In this long-term study (eight months), a wastewater-based epidemiology program was initiated as a decision support tool for the detection and containment of COVID-19 spread in the Technion campus. The on-campus students’ accommodations (∼3,300 residents) were divided into housing clusters and monitored through wastewater SARS-CoV-2 surveillance in 10 manholes. Results were used to create a ‘traffic-light’ scheme allowing the Technion’s COVID-19 task force to track COVID-19 spatiotemporal spread on the campus, and consequently, contain it before high morbidity levels develop. Of the 523 sewage samples analysed, 87.4% were negative for SARS-CoV-2 while 11.5% were positive, corroborating morbidity information the COVID-19 task force had. For 7.6% of the SARS-CoV-2 positive samples, the task force had no information about positive resident/s. In these events, new cases were identified after the relevant residents were clinically surge tested for COVID-19. Hence, in these instances, wastewater surveillance provided early warning helping to secure the health of the campus residents by minimising COVID-19 spread. The inflammation biomarker ferritin levels in SARS-CoV-2 positive sewage samples were significantly higher than in negative ones. This may indicate that in the future, ferritin (and other biomarkers) concentrations in wastewater could serve as indicators of infectious and inflammatory disease outbreaks.

@article{f5179821b3be429091f4982bc0545cd9,
title = "Whole campus wastewater surveillance of SARS-CoV-2 for COVID-19 outbreak management",
abstract = "In this long-term study (eight months), a wastewater-based epidemiology program was initiated as a decision support tool for the detection and containment of COVID-19 spread in the Technion campus. The on-campus students{\textquoteright} accommodations (∼3,300 residents) were divided into housing clusters and monitored through wastewater SARS-CoV-2 surveillance in 10 manholes. Results were used to create a {\textquoteleft}traffic-light{\textquoteright} scheme allowing the Technion{\textquoteright}s COVID-19 task force to track COVID-19 spatiotemporal spread on the campus, and consequently, contain it before high morbidity levels develop. Of the 523 sewage samples analysed, 87.4% were negative for SARS-CoV-2 while 11.5% were positive, corroborating morbidity information the COVID-19 task force had. For 7.6% of the SARS-CoV-2 positive samples, the task force had no information about positive resident/s. In these events, new cases were identified after the relevant residents were clinically surge tested for COVID-19. Hence, in these instances, wastewater surveillance provided early warning helping to secure the health of the campus residents by minimising COVID-19 spread. The inflammation biomarker ferritin levels in SARS-CoV-2 positive sewage samples were significantly higher than in negative ones. This may indicate that in the future, ferritin (and other biomarkers) concentrations in wastewater could serve as indicators of infectious and inflammatory disease outbreaks.",
author = "Y. Sharaby and Y. Gilboa and Y. Alfiya and S. Sabach and U. Cheruti and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2023 The Authors.",
year = "2023",
month = feb,
day = "15",
doi = "10.2166/wst.2023.030",
language = "אנגלית",
volume = "87",
pages = "910--923",
journal = "Water Science and Technology",
issn = "0273-1223",
publisher = "IWA Publishing",
number = "4",

}

Assessing water use and reuse options - a holistic analysis of a Model City, coupling dynamic system modelling with Life Cycle Assessment

Gilboa Y, Friedler E, Schütze M. Assessing water use and reuse options - a holistic analysis of a Model City, coupling dynamic system modelling with Life Cycle Assessment. Urban Water Journal. 2023;20(7):844-858. https://doi.org/10.1080/1573062X.2023.2211959
 

A dynamic model, fed with time-variant inputs, of the entire water urban system, coupled with Life Cycle Assessment (LCA) and Life Cycle Costing (LCC), was developed and applied to perform water balance analysis and to assess the environmental and economic aspects of water reuse. Six scenarios using different water sources potable water, rainwater, greywater, and treated wastewater were compared for a future Model City under typical Israeli conditions. The integrated dynamic simulation-LCA-LCC approach considers demands for several water resources and their availability, contains several feedback loops in the water system, and can be applied to any case study. Finally, the combined simulation-LCA-LCC was embedded into an optimisation framework. Results indicate that using treated greywater or treated wastewater for non-potable uses were the most economical scenarios. Business-as-usual scenario, where all urban water functions use potable water, displays the largest negative environmental impacts in all categories compared to using alternative water sources.

@article{0fc7dfe38cfe4e8f832dcd7df873d05d,
title = "Assessing water use and reuse options - a holistic analysis of a Model City, coupling dynamic system modelling with Life Cycle Assessment",
abstract = "A dynamic model, fed with time-variant inputs, of the entire water urban system, coupled with Life Cycle Assessment (LCA) and Life Cycle Costing (LCC), was developed and applied to perform water balance analysis and to assess the environmental and economic aspects of water reuse. Six scenarios using different water sources potable water, rainwater, greywater, and treated wastewater were compared for a future Model City under typical Israeli conditions. The integrated dynamic simulation-LCA-LCC approach considers demands for several water resources and their availability, contains several feedback loops in the water system, and can be applied to any case study. Finally, the combined simulation-LCA-LCC was embedded into an optimisation framework. Results indicate that using treated greywater or treated wastewater for non-potable uses were the most economical scenarios. Business-as-usual scenario, where all urban water functions use potable water, displays the largest negative environmental impacts in all categories compared to using alternative water sources.",
keywords = "alternative water sources, dynamic simulation, Greywater / wastewater reuse, LCA, optimization, rainwater harvesting, Urban water cycle",
author = "Yael Gilboa and Eran Friedler and Manfred Sch{\"u}tze",
note = "Publisher Copyright: {\textcopyright} 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.",
year = "2023",
doi = "10.1080/1573062X.2023.2211959",
language = "אנגלית",
volume = "20",
pages = "844--858",
journal = "Urban Water Journal",
issn = "1573-062X",
publisher = "Taylor and Francis Ltd.",
number = "7",

}

2022

A novel approach for accurate quantification of lake residence time — Lake Kinneret as a case study

Gilboa Y, Friedler E, Talhami F, Gal G. A novel approach for accurate quantification of lake residence time — Lake Kinneret as a case study. Water Research X. 2022 Aug 1;16:100149. https://doi.org/10.1016/j.wroa.2022.100149
 

Water residence time, which is affected by increasing water demands and climate change, plays a crucial role in lakes and reservoirs since it influences many natural physical and ecological processes that eventually impact the water quality of the waterbody. Thus, accurate quantification of the water residence time and its distribution is an important tool in lake management. In this study we present a novel approach for assessing the residence time in lakes and reservoirs. The approach is based on the Leslie matrix model that was originally developed for the analysis of age-structured biological population dynamics. In this approach the water in the lake is divided into different age classes each representing the time since the “parcel” of water entered the lake and provides an overall picture of the water age structure. The traditional approach for calculating residence times, which relies only on the lake volume and annual inflow or outflow volumes thereby disregarding any previous information, is very sensitive to large interannual variation. While the proposed approach produces the fraction and volume distribution curves of all age classes within the lake for each simulated timestep. Thus, in addition to mean residence time, the fraction of young water (FYW), quantifying the “young” fraction of water in the lake can be analyzed. The same is true for any other age class of water. The approach was applied to Lake Kinneret (Sea of Galilee) historical data collected over 32 years (1987-2018) and for prediction of long-term time series based on several future scenarios (inflows and outflows). It offers a more accurate quantification of the mean residence time of water in a lake and can easily be adapted to other waterbodies. Comparison of simulation results may serve as basis for determining the lake's management policy, by controlling the inflows and outflows, that will affect both the mean residence time and the fraction of “young/old” age classes of water.

@article{804d77166af647169e195fcda7a1412f,
title = "A novel approach for accurate quantification of lake residence time — Lake Kinneret as a case study",
abstract = "Water residence time, which is affected by increasing water demands and climate change, plays a crucial role in lakes and reservoirs since it influences many natural physical and ecological processes that eventually impact the water quality of the waterbody. Thus, accurate quantification of the water residence time and its distribution is an important tool in lake management. In this study we present a novel approach for assessing the residence time in lakes and reservoirs. The approach is based on the Leslie matrix model that was originally developed for the analysis of age-structured biological population dynamics. In this approach the water in the lake is divided into different age classes each representing the time since the “parcel” of water entered the lake and provides an overall picture of the water age structure. The traditional approach for calculating residence times, which relies only on the lake volume and annual inflow or outflow volumes thereby disregarding any previous information, is very sensitive to large interannual variation. While the proposed approach produces the fraction and volume distribution curves of all age classes within the lake for each simulated timestep. Thus, in addition to mean residence time, the fraction of young water (FYW), quantifying the “young” fraction of water in the lake can be analyzed. The same is true for any other age class of water. The approach was applied to Lake Kinneret (Sea of Galilee) historical data collected over 32 years (1987-2018) and for prediction of long-term time series based on several future scenarios (inflows and outflows). It offers a more accurate quantification of the mean residence time of water in a lake and can easily be adapted to other waterbodies. Comparison of simulation results may serve as basis for determining the lake's management policy, by controlling the inflows and outflows, that will affect both the mean residence time and the fraction of “young/old” age classes of water.",
keywords = "Fraction of young water, Hydraulic age distribution, Lake Kinneret, Leslie matrix model, Management policy, Mean residence time",
author = "Yael Gilboa and Eran Friedler and Firas Talhami and Gideon Gal",
note = "Publisher Copyright: {\textcopyright} 2022",
year = "2022",
month = aug,
day = "1",
doi = "10.1016/j.wroa.2022.100149",
language = "אנגלית",
volume = "16",
journal = "Water Research X",
issn = "2589-9147",
publisher = "Elsevier Ltd.",

}

Bacterial repair and recovery after UV LED disinfection: implications for water reuse

Randall TE, Linden YS, Gamboa J, Real B, Friedler E, Linden KG. Bacterial repair and recovery after UV LED disinfection: implications for water reuse. Environmental Science: Water Research and Technology. 2022 May 24;8(8):1700-1708. https://doi.org/10.1039/d1ew00836f
 

Concern over water scarcity is turning global attention towards reclaiming wastewater to fulfill unmet water demands. Innovative water treatment solutions, like UV LEDs, can be applied in novel ways to treat wastewater effluent for water reuse. However, the ability of microorganisms to repair and regrow after UV LED disinfection in distribution systems fed by recycled wastewater effluent used for beneficial reuse needs to be understood for system design. Therefore, the objective of this research was to understand conditions that impact bacterial repair and regrowth following UV LED exposure and the significance for UV LED disinfection in reuse settings using Pseudomonas aeruginosa as a test organism. The effect of irradiation with 265 nm and 285 nm UV LEDs on P. aeruginosa repair and regrowth was studied in both low and high nutrient waters and dark and light post-UV conditions. Dark repair and regrowth mechanisms represent scenarios of pipe networks, covered storage and drip irrigation, whereas photorepair could occur in a holding pond during recharge or an agricultural reuse scenario. Interestingly, dark repair and regrowth were not observed in any of the treatment conditions. Water matrix did not have any statistically significant effect on P. aeruginosa recovery. UV light emitted at 265 nm inhibited percent photorepair at higher rates than 285 nm, although 265 nm had the highest absolute photorepair value (103.86 CFU mL−1) after a 5 mJ cm−2 exposure. A water reuse scenario, with 285 nm UV LEDs and fluences up to 100 mJ cm−2, revealed that the maximum photorepair potential was reached within 45 minutes. For fluences 10 mJ cm−2 and higher in wastewater effluent, the maximum P. aeruginosa percent photorepair was 0.81%.

@article{0b8f7117d7c54c7e96a81fdb45a638d0,
title = "Bacterial repair and recovery after UV LED disinfection: implications for water reuse",
abstract = "Concern over water scarcity is turning global attention towards reclaiming wastewater to fulfill unmet water demands. Innovative water treatment solutions, like UV LEDs, can be applied in novel ways to treat wastewater effluent for water reuse. However, the ability of microorganisms to repair and regrow after UV LED disinfection in distribution systems fed by recycled wastewater effluent used for beneficial reuse needs to be understood for system design. Therefore, the objective of this research was to understand conditions that impact bacterial repair and regrowth following UV LED exposure and the significance for UV LED disinfection in reuse settings using Pseudomonas aeruginosa as a test organism. The effect of irradiation with 265 nm and 285 nm UV LEDs on P. aeruginosa repair and regrowth was studied in both low and high nutrient waters and dark and light post-UV conditions. Dark repair and regrowth mechanisms represent scenarios of pipe networks, covered storage and drip irrigation, whereas photorepair could occur in a holding pond during recharge or an agricultural reuse scenario. Interestingly, dark repair and regrowth were not observed in any of the treatment conditions. Water matrix did not have any statistically significant effect on P. aeruginosa recovery. UV light emitted at 265 nm inhibited percent photorepair at higher rates than 285 nm, although 265 nm had the highest absolute photorepair value (103.86 CFU mL−1) after a 5 mJ cm−2 exposure. A water reuse scenario, with 285 nm UV LEDs and fluences up to 100 mJ cm−2, revealed that the maximum photorepair potential was reached within 45 minutes. For fluences 10 mJ cm−2 and higher in wastewater effluent, the maximum P. aeruginosa percent photorepair was 0.81%.",
author = "Randall, {Tara E.} and Linden, {Yarrow S.} and Jasmine Gamboa and Breanna Real and Eran Friedler and Linden, {Karl G.}",
note = "Publisher Copyright: {\textcopyright} 2022 The Royal Society of Chemistry.",
year = "2022",
month = may,
day = "24",
doi = "10.1039/d1ew00836f",
language = "אנגלית",
volume = "8",
pages = "1700--1708",
journal = "Environmental Science: Water Research and Technology",
issn = "2053-1400",
publisher = "Royal Society of Chemistry",
number = "8",

}

Public perceptions and perspectives on alternative sources of water for reuse generated at the household level

Portman ME, Vdov O, Schuetze M, Gilboa Y, Friedler E. Public perceptions and perspectives on alternative sources of water for reuse generated at the household level. Water Reuse. 2022 Mar 2;12(1):157-174. https://doi.org/10.2166/wrd.2022.002
 

Studying perceptions about reuse of alternative water sources informs about conditions necessary for transition to large-scale decentralized water reuse. We administered a perceptions survey to the public based on results of initial open interviews of water management experts in Israel. Experts indicated their views on impediments to widespread household water reuse which became the basis for developing the ques-tionnaire. The latter aimed to understand views among the general public of: (a) willingness to adopt reuse practices from three sources: greywater, air conditioner condensate and roof-harvested rainwater; and (b) preferences for targeted use of these three types of reused water. The survey elicited 372 responses. A maximum-likelihood regression analysis was conducted using independent variables (i.e., demo-graphic characteristics, individual positions regarding the state of the country’s water resources and plans for the provision of domestic water (i.e., desalination), knowledge of the reuse practices and views about risks from various uses of the reused water, including off-premise uses). Willingness to implement reuse practices served as the dependent variable. We found that respondents indicating that they heard of the reuse of the particular types of reuse practices (variable: ‘Knowledge’) was the most significant of the independent variables for all three alternative water sources. Also, using an analytic hierarchy process, we determined that health risks were much more important when com-pared to convenience of use and costs under hypothetical scenarios of both moderate and significant savings in monthly water expenditures.

@article{45e8e60af33344b599676b3a32b43d4e,
title = "Public perceptions and perspectives on alternative sources of water for reuse generated at the household level",
abstract = "Studying perceptions about reuse of alternative water sources informs about conditions necessary for transition to large-scale decentralized water reuse. We administered a perceptions survey to the public based on results of initial open interviews of water management experts in Israel. Experts indicated their views on impediments to widespread household water reuse which became the basis for developing the ques-tionnaire. The latter aimed to understand views among the general public of: (a) willingness to adopt reuse practices from three sources: greywater, air conditioner condensate and roof-harvested rainwater; and (b) preferences for targeted use of these three types of reused water. The survey elicited 372 responses. A maximum-likelihood regression analysis was conducted using independent variables (i.e., demo-graphic characteristics, individual positions regarding the state of the country{\textquoteright}s water resources and plans for the provision of domestic water (i.e., desalination), knowledge of the reuse practices and views about risks from various uses of the reused water, including off-premise uses). Willingness to implement reuse practices served as the dependent variable. We found that respondents indicating that they heard of the reuse of the particular types of reuse practices (variable: {\textquoteleft}Knowledge{\textquoteright}) was the most significant of the independent variables for all three alternative water sources. Also, using an analytic hierarchy process, we determined that health risks were much more important when com-pared to convenience of use and costs under hypothetical scenarios of both moderate and significant savings in monthly water expenditures.",
keywords = "air conditioner condensate, decentralized reuse, household water, household-generated greywater reuse, public perceptions, rainwater harvesting",
author = "Portman, {Michelle E.} and Olga Vdov and Manfred Schuetze and Yael Gilboa and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2022 The Authors.",
year = "2022",
month = mar,
day = "2",
doi = "10.2166/wrd.2022.002",
language = "אנגלית",
volume = "12",
pages = "157--174",
journal = "Water Reuse",
issn = "2709-6092",
publisher = "IWA Publishing",
number = "1",

}

Optimizing the Control of Decentralized Rainwater Harvesting Systems for Reducing Urban Drainage Flows

Snir O, Friedler E, Ostfeld A. Optimizing the Control of Decentralized Rainwater Harvesting Systems for Reducing Urban Drainage Flows. Water (Switzerland). 2022 Feb 1;14(4):571. https://doi.org/10.3390/w14040571
 

The practice of rainwater harvesting (RWH) has been studied extensively in recent years, as it has the potential to alleviate some of the increasing stress on urban water distribution systems and drainage networks. Within the field, an approach of real-time control of rainwater storage is emerging as a method to improve the ability of RWH systems to reduce runoff and urban drainage flows. As applying real-time control on RWH tanks means releasing water that could be used for supply, applying controlled-release policies often hinders the RWH system’s ability to supply water. The suggested study presents an approach that has the potential to improve the capability of a distributed network of RWH systems to mitigate peak drainage flows while substantially reducing the impact on harvested rainwater availability. The suggested method uses a genetic algorithm to generate release policies, which are tailored for any given rain event and initial conditions. The algorithm utilizes the modeled drainage system’s response to a given rainfall pattern and manages to substantially reduce peak drainage flows with little impact on available rainwater when compared to the conventional no-release alternative and other active release methods.

@article{9f02bc51a1bd46339b66ff3e1d5e7432,
title = "Optimizing the Control of Decentralized Rainwater Harvesting Systems for Reducing Urban Drainage Flows",
abstract = "The practice of rainwater harvesting (RWH) has been studied extensively in recent years, as it has the potential to alleviate some of the increasing stress on urban water distribution systems and drainage networks. Within the field, an approach of real-time control of rainwater storage is emerging as a method to improve the ability of RWH systems to reduce runoff and urban drainage flows. As applying real-time control on RWH tanks means releasing water that could be used for supply, applying controlled-release policies often hinders the RWH system{\textquoteright}s ability to supply water. The suggested study presents an approach that has the potential to improve the capability of a distributed network of RWH systems to mitigate peak drainage flows while substantially reducing the impact on harvested rainwater availability. The suggested method uses a genetic algorithm to generate release policies, which are tailored for any given rain event and initial conditions. The algorithm utilizes the modeled drainage system{\textquoteright}s response to a given rainfall pattern and manages to substantially reduce peak drainage flows with little impact on available rainwater when compared to the conventional no-release alternative and other active release methods.",
keywords = "Rainwater harvesting, Real-time control, Stormwater retention, Urban drainage system",
author = "Ofer Snir and Eran Friedler and Avi Ostfeld",
note = "Publisher Copyright: {\textcopyright} 2022 by the authors. Licensee MDPI, Basel, Switzerland.",
year = "2022",
month = feb,
day = "1",
doi = "10.3390/w14040571",
language = "אנגלית",
volume = "14",
journal = "Water (Switzerland)",
issn = "2073-4441",
publisher = "MDPI Multidisciplinary Digital Publishing Institute",
number = "4",

}

Regressing SARS-CoV-2 Sewage Measurements Onto COVID-19 Burden in the Population: A Proof-of-Concept for Quantitative Environmental Surveillance

Bar-Or I, Yaniv K, Shagan M, Ozer E, Weil M, Indenbaum V et al. Regressing SARS-CoV-2 Sewage Measurements Onto COVID-19 Burden in the Population: A Proof-of-Concept for Quantitative Environmental Surveillance. Frontiers in Public Health. 2022 Jan 3;9:561710. https://doi.org/10.3389/fpubh.2021.561710
 

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an RNA virus, a member of the coronavirus family of respiratory viruses that includes severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) and the Middle East respiratory syndrome (MERS). It has had an acute and dramatic impact on health care systems, economies, and societies of affected countries during the past 8 months. Widespread testing and tracing efforts are being employed in many countries in attempts to contain and mitigate this pandemic. Recent data has indicated that fecal shedding of SARS-CoV-2 is common and that the virus RNA can be detected in wastewater. This indicates that wastewater monitoring may provide a potentially efficient tool for the epidemiological surveillance of SARS-CoV-2 infection in large populations at relevant scales. In particular, this provides important means of (i) estimating the extent of outbreaks and their spatial distributions, based primarily on in-sewer measurements, (ii) managing the early-warning system quantitatively and efficiently, and (iii) verifying disease elimination. Here we report different virus concentration methods using polyethylene glycol (PEG), alum, or filtration techniques as well as different RNA extraction methodologies, providing important insights regarding the detection of SARS-CoV-2 RNA in sewage. Virus RNA particles were detected in wastewater in several geographic locations in Israel. In addition, a correlation of virus RNA concentration to morbidity was detected in Bnei-Barak city during April 2020. This study presents a proof of concept for the use of direct raw sewage-associated virus data, during the pandemic in the country as a potential epidemiological tool.

@article{6643725e8e8a446d8b2861ded776134e,
title = "Regressing SARS-CoV-2 Sewage Measurements Onto COVID-19 Burden in the Population: A Proof-of-Concept for Quantitative Environmental Surveillance",
abstract = "Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an RNA virus, a member of the coronavirus family of respiratory viruses that includes severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) and the Middle East respiratory syndrome (MERS). It has had an acute and dramatic impact on health care systems, economies, and societies of affected countries during the past 8 months. Widespread testing and tracing efforts are being employed in many countries in attempts to contain and mitigate this pandemic. Recent data has indicated that fecal shedding of SARS-CoV-2 is common and that the virus RNA can be detected in wastewater. This indicates that wastewater monitoring may provide a potentially efficient tool for the epidemiological surveillance of SARS-CoV-2 infection in large populations at relevant scales. In particular, this provides important means of (i) estimating the extent of outbreaks and their spatial distributions, based primarily on in-sewer measurements, (ii) managing the early-warning system quantitatively and efficiently, and (iii) verifying disease elimination. Here we report different virus concentration methods using polyethylene glycol (PEG), alum, or filtration techniques as well as different RNA extraction methodologies, providing important insights regarding the detection of SARS-CoV-2 RNA in sewage. Virus RNA particles were detected in wastewater in several geographic locations in Israel. In addition, a correlation of virus RNA concentration to morbidity was detected in Bnei-Barak city during April 2020. This study presents a proof of concept for the use of direct raw sewage-associated virus data, during the pandemic in the country as a potential epidemiological tool.",
keywords = "COVID-19, SARS-CoV-2, corona, sewage, surveillance, virus concentration, wastewater based epidemiology",
author = "Itay Bar-Or and Karin Yaniv and Marilou Shagan and Eden Ozer and Merav Weil and Victoria Indenbaum and Michal Elul and Oran Erster and Ella Mendelson and Batya Mannasse and Rachel Shirazi and Esti Kramarsky-Winter and Oded Nir and Hala Abu-Ali and Zeev Ronen and Ehud Rinott and Lewis, {Yair E.} and Eran Friedler and Eden Bitkover and Yossi Paitan and Yakir Berchenko and Ariel Kushmaro",
note = "Publisher Copyright: Copyright {\textcopyright} 2022 Bar-Or, Yaniv, Shagan, Ozer, Weil, Indenbaum, Elul, Erster, Mendelson, Mannasse, Shirazi, Kramarsky-Winter, Nir, Abu-Ali, Ronen, Rinott, Lewis, Friedler, Bitkover, Paitan, Berchenko and Kushmaro.",
year = "2022",
month = jan,
day = "3",
doi = "10.3389/fpubh.2021.561710",
language = "אנגלית",
volume = "9",
journal = "Frontiers in Public Health",
issn = "2296-2565",
publisher = "Frontiers Media S.A.",

}

2021

City-level SARS-CoV-2 sewage surveillance

Yaniv K, Shagan M, Lewis YE, Kramarsky-Winter E, Weil M, Indenbaum V et al. City-level SARS-CoV-2 sewage surveillance. Chemosphere. 2021 Nov;283:131194. https://doi.org/10.1016/j.chemosphere.2021.131194
 

The COVID-19 pandemic created a global crisis impacting not only healthcare systems, but also economics and society. Therefore, it is important to find novel methods for monitoring disease activity. Recent data have indicated that fecal shedding of SARS-CoV-2 is common, and that viral RNA can be detected in wastewater. This suggests that wastewater monitoring is a potentially efficient tool for both epidemiological surveillance, and early warning for SARS-CoV-2 circulation at the population level. In this study we sampled an urban wastewater infrastructure in the city of Ashkelon (̴ 150,000 population), Israel, during the end of the first COVID-19 wave in May 2020 when the number of infections seemed to be waning. We were able to show varying presence of SARS-CoV-2 RNA in wastewater from several locations in the city during two sampling periods, before the resurgence was clinically apparent. This was expressed with a new index, Normalized Viral Load (NVL) which can be used in different area scales to define levels of virus activity such as red (high) or green (no), and to follow morbidity in the population at the tested area. The rise in viral load between the two sampling periods (one week apart) indicated an increase in morbidity that was evident two weeks to a month later in the population. Thus, this methodology may provide an early indication for SARS-CoV-2 infection outbreak in a population before an outbreak is clinically apparent.

@article{b833f917662542a4a0fba6263e60d4dd,
title = "City-level SARS-CoV-2 sewage surveillance",
abstract = "The COVID-19 pandemic created a global crisis impacting not only healthcare systems, but also economics and society. Therefore, it is important to find novel methods for monitoring disease activity. Recent data have indicated that fecal shedding of SARS-CoV-2 is common, and that viral RNA can be detected in wastewater. This suggests that wastewater monitoring is a potentially efficient tool for both epidemiological surveillance, and early warning for SARS-CoV-2 circulation at the population level. In this study we sampled an urban wastewater infrastructure in the city of Ashkelon (̴ 150,000 population), Israel, during the end of the first COVID-19 wave in May 2020 when the number of infections seemed to be waning. We were able to show varying presence of SARS-CoV-2 RNA in wastewater from several locations in the city during two sampling periods, before the resurgence was clinically apparent. This was expressed with a new index, Normalized Viral Load (NVL) which can be used in different area scales to define levels of virus activity such as red (high) or green (no), and to follow morbidity in the population at the tested area. The rise in viral load between the two sampling periods (one week apart) indicated an increase in morbidity that was evident two weeks to a month later in the population. Thus, this methodology may provide an early indication for SARS-CoV-2 infection outbreak in a population before an outbreak is clinically apparent.",
keywords = "Early warning, Normalized viral load, Population monitoring, SARS-CoV-2, Wastewater epidemiology",
author = "Karin Yaniv and Marilou Shagan and Lewis, {Yair E.} and Esti Kramarsky-Winter and Merav Weil and Victoria Indenbaum and Michal Elul and Oran Erster and Brown, {Alin Sela} and Ella Mendelson and Batya Mannasse and Rachel Shirazi and Satish Lakkakula and Oren Miron and Ehud Rinott and Baibich, {Ricardo Gilead} and Iris Bigler and Matan Malul and Rotem Rishti and Asher Brenner and Eran Friedler and Yael Gilboa and Sara Sabach and Yuval Alfiya and Uta Cheruti and {Nadav davidovich}, davidovich and Jacob Moran-Gilad and Yakir Berchenko and Itay Bar-Or and Ariel Kushmaro",
note = "Publisher Copyright: {\textcopyright} 2021 Elsevier Ltd",
year = "2021",
month = nov,
doi = "10.1016/j.chemosphere.2021.131194",
language = "אנגלית",
volume = "283",
journal = "Chemosphere",
issn = "0045-6535",
publisher = "Elsevier Ltd.",

}

Dual benefit of rainwater harvesting—high temporal-resolution stochastic modelling

Snir O, Friedler E. Dual benefit of rainwater harvesting—high temporal-resolution stochastic modelling. Water (Switzerland). 2021 Sep;13(17):2415. https://doi.org/10.3390/w13172415
 

The objective of the presented study was to develop a high-temporal-resolution stochastic rainwater harvesting (RWH) model for assessing the dual benefits of RWH: potable water savings and runoff reduction. Model inputs of rainfall and water demand are used in a stochastic manner, maintaining their natural pattern, while generating realistic noise and temporal variability. The dynamic model solves a mass-balance equation for the rainwater tank, while logging all inflows and outflows from it for post-simulation analysis. The developed model can simulate various building sizes, roof areas, rainwater tank volumes, controlled release policies, and time periods, providing a platform for assessing short-and long-term benefits. Standard passive rainwater harvesting operation and real-time control policies (controlled release) are demonstrated for a 40-apartment building with rainfall data typical for a Mediterranean climate, showing the system’s ability to supply water for non-potable uses, while reducing runoff volumes and flows, with the latter significantly improved when water is intentionally released from the tank prior to an expected overflow. The model could be used to further investigate the effects of rainwater harvesting on the urban water cycle, by coupling it with an urban drainage model and simulating the operation of a distributed network of micro-reservoirs that supply water and mitigate floods.

@article{375a203686494565aca88a40ebb3200b,
title = "Dual benefit of rainwater harvesting—high temporal-resolution stochastic modelling",
abstract = "The objective of the presented study was to develop a high-temporal-resolution stochastic rainwater harvesting (RWH) model for assessing the dual benefits of RWH: potable water savings and runoff reduction. Model inputs of rainfall and water demand are used in a stochastic manner, maintaining their natural pattern, while generating realistic noise and temporal variability. The dynamic model solves a mass-balance equation for the rainwater tank, while logging all inflows and outflows from it for post-simulation analysis. The developed model can simulate various building sizes, roof areas, rainwater tank volumes, controlled release policies, and time periods, providing a platform for assessing short-and long-term benefits. Standard passive rainwater harvesting operation and real-time control policies (controlled release) are demonstrated for a 40-apartment building with rainfall data typical for a Mediterranean climate, showing the system{\textquoteright}s ability to supply water for non-potable uses, while reducing runoff volumes and flows, with the latter significantly improved when water is intentionally released from the tank prior to an expected overflow. The model could be used to further investigate the effects of rainwater harvesting on the urban water cycle, by coupling it with an urban drainage model and simulating the operation of a distributed network of micro-reservoirs that supply water and mitigate floods.",
keywords = "Rainwater harvesting, Realtime control, Runoff minimization, Stochastic simulation, Water saving",
author = "Ofer Snir and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2021 by the authors. Licensee MDPI, Basel, Switzerland.",
year = "2021",
month = sep,
doi = "10.3390/w13172415",
language = "אנגלית",
volume = "13",
journal = "Water (Switzerland)",
issn = "2073-4441",
publisher = "MDPI Multidisciplinary Digital Publishing Institute",
number = "17",

}

H2S removal from groundwater by chemical free advanced oxidation process using UV‐C/VUV radiation

Gilboa Y, Alfiya Y, Sabach S, Friedler E, Dubowski Y. H2S removal from groundwater by chemical free advanced oxidation process using UV‐C/VUV radiation. Molecules. 2021 Jul 1;26(13):4016. https://doi.org/10.3390/molecules26134016
 

Sulfide species may be present in groundwater due to natural processes or due to anthropogenic activity. H2S contamination poses odor nuisance and may also lead to adverse health effects. Advanced oxidation processes (AOPs) are considered promising treatments for hydrogen-sulfide removal from water, but conventional AOPs usually require continuous chemical dosing, as well as post‐treatment, when solid catalysts are applied. Vacuum‐UV (VUV) radiation can generate ∙OH in situ via water photolysis, initiating chemical‐free AOP. The present study investigated the applicability of VUV‐based AOP for removal of H2S both in synthetic solutions and in real ground-water, comparing combined UV‐C/VUV and UV‐C only radiation in a continuous‐flow reactor. In deionized water, H2S degradation was much faster under the combined radiation, dominated by indirect photolysis, and indicated the formation of sulfite intermediates that convert to sulfate at high radiation doses. Sulfide was efficiently removed from natural groundwater by the two examined lamps, with no clear preference between them. However, in anoxic conditions, common in sulfide‐containing groundwater, a small advantage for the combined lamp was observed. These results demonstrate the potential of utilizing VUV‐based AOP for treating H2S contamination in groundwater as a chemical‐free treatment, which can be especially attractive to remote small treatment facilities.

@article{358bb131aa2c4fa88da1979de48aa649,
title = "H2S removal from groundwater by chemical free advanced oxidation process using UV‐C/VUV radiation",
abstract = "Sulfide species may be present in groundwater due to natural processes or due to anthropogenic activity. H2S contamination poses odor nuisance and may also lead to adverse health effects. Advanced oxidation processes (AOPs) are considered promising treatments for hydrogen-sulfide removal from water, but conventional AOPs usually require continuous chemical dosing, as well as post‐treatment, when solid catalysts are applied. Vacuum‐UV (VUV) radiation can generate ∙OH in situ via water photolysis, initiating chemical‐free AOP. The present study investigated the applicability of VUV‐based AOP for removal of H2S both in synthetic solutions and in real ground-water, comparing combined UV‐C/VUV and UV‐C only radiation in a continuous‐flow reactor. In deionized water, H2S degradation was much faster under the combined radiation, dominated by indirect photolysis, and indicated the formation of sulfite intermediates that convert to sulfate at high radiation doses. Sulfide was efficiently removed from natural groundwater by the two examined lamps, with no clear preference between them. However, in anoxic conditions, common in sulfide‐containing groundwater, a small advantage for the combined lamp was observed. These results demonstrate the potential of utilizing VUV‐based AOP for treating H2S contamination in groundwater as a chemical‐free treatment, which can be especially attractive to remote small treatment facilities.",
keywords = "Advanced oxidation process (AOP), vacuum‐UV (VUV), photo‐oxidation, Groundwater, Hydrogen sulfide, Water treatment",
author = "Yael Gilboa and Yuval Alfiya and Sara Sabach and Eran Friedler and Yael Dubowski",
note = "Publisher Copyright: {\textcopyright} 2021 by the authors. Licensee MDPI, Basel, Switzerland.",
year = "2021",
month = jul,
day = "1",
doi = "10.3390/molecules26134016",
language = "אנגלית",
volume = "26",
journal = "Molecules",
issn = "1420-3049",
publisher = "MDPI Multidisciplinary Digital Publishing Institute",
number = "13",

}

Impact of suspended solids and organic matter on chlorine and UV disinfection efficiency of greywater

Friedler E, Chavez DF, Alfiya Y, Gilboa Y, Gross A. Impact of suspended solids and organic matter on chlorine and UV disinfection efficiency of greywater. Water (Switzerland). 2021 Jan 2;13(2):214. https://doi.org/10.3390/w13020214
 

Reusing greywater (GW) can lower domestic water consumption. However, the GW must be treated and disinfected for securing user health. This research studied at the laboratory scale, and in flow-through setups, which are generally used in full-scale GW treatment the disinfection efficiency of the two commonly used technologies (a) chlorination and (b) low-pressure UV irradiation. The disinfection methods were studied under a commonly found range of total suspended solids (TSS; 3.9–233 mg/L) and 5-d biochemical oxygen demand (BOD5) concentrations (0–107 mg/L) as a representative/proxy of bioavailable organic matter. The negative effect of TSS began even at low concentrations (<20 mg/L) and increased consistently with increasing TSS concentrations across all the concentrations tested. On the other hand, the negative effect of BOD5 on FC inactivation was observed only when its concentration was higher than 50 mg/L. Multiple linear regression models were developed following the laboratory results, establishing a correlation between FC inactivation by either chlorination or UV irradiation and initial FC, TSS, and BOD5 concentrations. The models were validated against the results from the flow-through reactors and explained the majority of the variability in the measured FC inactivation. Conversion factors between the laboratory scales and the flow-through reactor experiments were established. These enable the prediction of the required residual chlorine concentration or the UV dose needed for an on-site flow-through reactor. This approach is valuable from both operational and research perspectives.

@article{b8798e5cb6a24b0c82408dca858470de,
title = "Impact of suspended solids and organic matter on chlorine and UV disinfection efficiency of greywater",
abstract = "Reusing greywater (GW) can lower domestic water consumption. However, the GW must be treated and disinfected for securing user health. This research studied at the laboratory scale, and in flow-through setups, which are generally used in full-scale GW treatment the disinfection efficiency of the two commonly used technologies (a) chlorination and (b) low-pressure UV irradiation. The disinfection methods were studied under a commonly found range of total suspended solids (TSS; 3.9–233 mg/L) and 5-d biochemical oxygen demand (BOD5) concentrations (0–107 mg/L) as a representative/proxy of bioavailable organic matter. The negative effect of TSS began even at low concentrations (<20 mg/L) and increased consistently with increasing TSS concentrations across all the concentrations tested. On the other hand, the negative effect of BOD5 on FC inactivation was observed only when its concentration was higher than 50 mg/L. Multiple linear regression models were developed following the laboratory results, establishing a correlation between FC inactivation by either chlorination or UV irradiation and initial FC, TSS, and BOD5 concentrations. The models were validated against the results from the flow-through reactors and explained the majority of the variability in the measured FC inactivation. Conversion factors between the laboratory scales and the flow-through reactor experiments were established. These enable the prediction of the required residual chlorine concentration or the UV dose needed for an on-site flow-through reactor. This approach is valuable from both operational and research perspectives.",
keywords = "BOD, Chlorination, Chlorine flow-through chamber, Chlorine tablet, Flow-through UV reactor, Greywater, Suspended solids, UV disinfection",
author = "Eran Friedler and Chavez, {Diana F.} and Yuval Alfiya and Yael Gilboa and Amit Gross",
note = "Publisher Copyright: {\textcopyright} 2021 by the authors. Licensee MDPI, Basel, Switzerland.",
year = "2021",
month = jan,
day = "2",
doi = "10.3390/w13020214",
language = "אנגלית",
volume = "13",
journal = "Water (Switzerland)",
issn = "2073-4441",
publisher = "MDPI Multidisciplinary Digital Publishing Institute",
number = "2",

}

2020

Framework, procedure, and tools for comprehensive evaluation of sustainable stormwater management: A review

Wu T, Song H, Wang J, Friedler E. Framework, procedure, and tools for comprehensive evaluation of sustainable stormwater management: A review. Water (Switzerland). 2020 May 1;12(5):1231. https://doi.org/10.3390/W12051231
 

Abstract: To better evaluate and enhance the performance and benefit of sustainable stormwater management (SSWM) in developing countries, this study proposes a comprehensive evaluation framework based on thorough literature review. This framework re-classifies evaluation goals and indicators into four aspects-stormwater system, integrated management, social engagement, and urban development. The purpose of this review is to provide a guideline for decision makers to choose appropriate goals and indicators according to different regional context. Meanwhile, a structured procedure for comprehensive evaluation of SSWM is proposed to guide a well-organised decision-making process. Furthermore, pros and cons of eight decision support tools, as well as their functional focus, are compared, aiming to provide references for SSWM in developing countries. Outcomes presented in this review are expected to support decision makers in the process of screening optimal SSWM strategies and monitoring SSWM projects.

@article{d8f73963efea44e0a1d132b94fbc90a9,
title = "Framework, procedure, and tools for comprehensive evaluation of sustainable stormwater management: A review",
abstract = "Abstract: To better evaluate and enhance the performance and benefit of sustainable stormwater management (SSWM) in developing countries, this study proposes a comprehensive evaluation framework based on thorough literature review. This framework re-classifies evaluation goals and indicators into four aspects-stormwater system, integrated management, social engagement, and urban development. The purpose of this review is to provide a guideline for decision makers to choose appropriate goals and indicators according to different regional context. Meanwhile, a structured procedure for comprehensive evaluation of SSWM is proposed to guide a well-organised decision-making process. Furthermore, pros and cons of eight decision support tools, as well as their functional focus, are compared, aiming to provide references for SSWM in developing countries. Outcomes presented in this review are expected to support decision makers in the process of screening optimal SSWM strategies and monitoring SSWM projects.",
keywords = "Comprehensive evaluation framework, Decision support tool, Sponge city, Stormwater management",
author = "Tiange Wu and Haihong Song and Jianbin Wang and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2020 by the authors.",
year = "2020",
month = may,
day = "1",
doi = "10.3390/W12051231",
language = "אנגלית",
volume = "12",
journal = "Water (Switzerland)",
issn = "2073-4441",
publisher = "MDPI Multidisciplinary Digital Publishing Institute",
number = "5",

}

Removal of organic micropollutants from biologically treated greywater using continuous-flow vacuum-UV/UVC photo-reactor

Dubowski Y, Alfiya Y, Gilboa Y, Sabach S, Friedler E. Removal of organic micropollutants from biologically treated greywater using continuous-flow vacuum-UV/UVC photo-reactor. Environmental Science and Pollution Research. 2020 Mar 1;27(7):7578-7587. https://doi.org/10.1007/s11356-019-07399-7
 

Despite growing apprehension regarding the fate of organic micropollutants (MPs) of emerging concern, little attention has been paid to their presence in domestic greywater, where they mainly originate from personal care products. Many MPs are not fully removed in conventional greywater treatments and require additional treatment. Vacuum-UV radiation (VUV) can generate ·OH in situ, via water photolysis, initiating advanced oxidation process (AOP) without any chemical addition. Despite growing interest in VUV-based AOP, its performance in real-life grey- or wastewater matrices has hardly been investigated. The present study investigates the removal of triclosan (TCS) and oxybenzone (BP3), common antibacterial and UV-filter MPs, in deionized water (DIW) and in treated greywater (TGW) using combined UVC/VUV or UVC only radiation in a continuous-flow reactor. Degradation kinetics of these MPs and their transformation products (TPs) were addressed, as well as bacterial growth inhibition of the resulting reactor’s effluent. In DIW, MP degradation was much faster under the combined UVC/VUV irradiation. In TGW, the combined radiation successfully removed both MPs but at lower efficiency than in DIW, as particles and dissolved organic matter (DOM) acted as radical scavengers. Filtration and partial DOM removal prior to irradiation improved the process efficiency and reduced energy requirements under the combined radiation (from 1.6 and 167 to 1.1 and 6.0 kWh m−3·ּorder−1 for TCS and BP3, respectively). VUV radiation also reduced TP concentrations in the effluent. As a result, bacterial growth inhibition of triclosan solution irradiated by VUC/VUV was lower than that irradiated by UVC light alone, for UV dose > 120 mJ cm−2.

@article{272524c563e04334911986c6904f99c2,
title = "Removal of organic micropollutants from biologically treated greywater using continuous-flow vacuum-UV/UVC photo-reactor",
abstract = "Despite growing apprehension regarding the fate of organic micropollutants (MPs) of emerging concern, little attention has been paid to their presence in domestic greywater, where they mainly originate from personal care products. Many MPs are not fully removed in conventional greywater treatments and require additional treatment. Vacuum-UV radiation (VUV) can generate ·OH in situ, via water photolysis, initiating advanced oxidation process (AOP) without any chemical addition. Despite growing interest in VUV-based AOP, its performance in real-life grey- or wastewater matrices has hardly been investigated. The present study investigates the removal of triclosan (TCS) and oxybenzone (BP3), common antibacterial and UV-filter MPs, in deionized water (DIW) and in treated greywater (TGW) using combined UVC/VUV or UVC only radiation in a continuous-flow reactor. Degradation kinetics of these MPs and their transformation products (TPs) were addressed, as well as bacterial growth inhibition of the resulting reactor{\textquoteright}s effluent. In DIW, MP degradation was much faster under the combined UVC/VUV irradiation. In TGW, the combined radiation successfully removed both MPs but at lower efficiency than in DIW, as particles and dissolved organic matter (DOM) acted as radical scavengers. Filtration and partial DOM removal prior to irradiation improved the process efficiency and reduced energy requirements under the combined radiation (from 1.6 and 167 to 1.1 and 6.0 kWh m−3·ּorder−1 for TCS and BP3, respectively). VUV radiation also reduced TP concentrations in the effluent. As a result, bacterial growth inhibition of triclosan solution irradiated by VUC/VUV was lower than that irradiated by UVC light alone, for UV dose > 120 mJ cm−2.",
keywords = "Advanced oxidation process (AOP), Greywater, Micropollutants of emerging concern, Oxybenzone, Triclosan, Vacuum-UV",
author = "Yael Dubowski and Yuval Alfiya and Yael Gilboa and Sara Sabach and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2019, Springer-Verlag GmbH Germany, part of Springer Nature.",
year = "2020",
month = mar,
day = "1",
doi = "10.1007/s11356-019-07399-7",
language = "אנגלית",
volume = "27",
pages = "7578--7587",
journal = "Environmental Science and Pollution Research",
issn = "0944-1344",
publisher = "Springer Science + Business Media",
number = "7",

}

Roof-Harvested rainwater use in household agriculture: Contributions to the sustainable development goals

Amos CC, Rahman A, Gathenya JM, Friedler E, Karim F, Renzaho A. Roof-Harvested rainwater use in household agriculture: Contributions to the sustainable development goals. Water (Switzerland). 2020 Feb 1;12(2):332. https://doi.org/10.3390/w12020332
 

Food and water are at the heart of sustainable development. Roof-harvested rainwater kept in rainwater storage systems (RSS) and used in household agriculture (HA) has the potential to increase yields and supplement household nutrition. Combined systems may contribute to at least eight of the United Nations' 17 Sustainable Development Goals (SDGs). In this paper, a daily analysis tool, ERain, is used to assess what area of vegetables can be reliably irrigated by roof-harvested rainwater. A socio-economic context is built around an orphanage in the semi-humid region of Nakuru, Kenya. Comparisons are made with the semi-arid region of East Pokot. A 225 kL closed masonry tank and a 1 ML open reservoir with an additional 8 kL/day of recycled water entering are analyzed for various roof sizes. The 225 kL RSS connected to 1000 m2 of roof and irrigating 1000 m2 could increase yields from 1850 to 4200 kg/year in Nakuru. If evaporation was controlled, the 1 mL RSS and recycled water system could support 4000 m2 of land, yielding nearly 20,000 kg/year, which is enough to meet the WHO recommended vegetable dietary requirements of the orphanage. A combination of crops, some for consumption and some for sale, could be grown.

@article{fd745dc3e51e4d0dbcbdc87cfd59737e,
title = "Roof-Harvested rainwater use in household agriculture: Contributions to the sustainable development goals",
abstract = "Food and water are at the heart of sustainable development. Roof-harvested rainwater kept in rainwater storage systems (RSS) and used in household agriculture (HA) has the potential to increase yields and supplement household nutrition. Combined systems may contribute to at least eight of the United Nations' 17 Sustainable Development Goals (SDGs). In this paper, a daily analysis tool, ERain, is used to assess what area of vegetables can be reliably irrigated by roof-harvested rainwater. A socio-economic context is built around an orphanage in the semi-humid region of Nakuru, Kenya. Comparisons are made with the semi-arid region of East Pokot. A 225 kL closed masonry tank and a 1 ML open reservoir with an additional 8 kL/day of recycled water entering are analyzed for various roof sizes. The 225 kL RSS connected to 1000 m2 of roof and irrigating 1000 m2 could increase yields from 1850 to 4200 kg/year in Nakuru. If evaporation was controlled, the 1 mL RSS and recycled water system could support 4000 m2 of land, yielding nearly 20,000 kg/year, which is enough to meet the WHO recommended vegetable dietary requirements of the orphanage. A combination of crops, some for consumption and some for sale, could be grown.",
keywords = "Agricultural water use from harvested rainwater, Household agriculture, Kenya, Rainwater harvesting, Rainwater storage systems, Sustainable development goals, Urban agriculture, Village",
author = "Amos, {Caleb Christian} and Ataur Rahman and Gathenya, {John Mwangi} and Eran Friedler and Fazlul Karim and Andre Renzaho",
note = "Publisher Copyright: {\textcopyright} 2020 by the authors.",
year = "2020",
month = feb,
day = "1",
doi = "10.3390/w12020332",
language = "אנגלית",
volume = "12",
journal = "Water (Switzerland)",
issn = "2073-4441",
publisher = "MDPI Multidisciplinary Digital Publishing Institute",
number = "2",

}

מים מן האוויר

הובר ל, כץ א, פרידלר ע, ברודאי ד. מים מן האוויר. הטכניון. 2020;14-15.
 
חוקרים בפקולטה להנדסה אזרחית וסביבתית פיתחו מערכת עצמאית המפיקה מים מהאוויר גם באזורים מדבריים. (מתוך המאמר)
@article{4d4bbccf373d4f638bacb031b8356bc1,
title = "מים מן האוויר",
abstract = "חוקרים בפקולטה להנדסה אזרחית וסביבתית פיתחו מערכת עצמאית המפיקה מים מהאוויר גם באזורים מדבריים. (מתוך המאמר)",
author = "לירון הובר and אילן כץ and ערן פרידלר and דוד ברודאי",
year = "2020",
language = "עברית",
pages = "14--15",
journal = "הטכניון",
issn = "0793-8543",

}

2019

Comparative life cycle sustainability assessment of urban water reuse at various centralization scales

Opher T, Friedler E, Shapira A. Comparative life cycle sustainability assessment of urban water reuse at various centralization scales. International Journal of Life Cycle Assessment. 2019 Jul 1;24(7):1319-1332. https://doi.org/10.1007/s11367-018-1469-1
 

Purpose: Population growth and urbanization lead to increasing water demand, putting significant pressure on natural water sources. The rising amounts of domestic wastewater (WW) in urban areas may be treated to serve as an alternative water source that may alleviate this pressure. This study examines sustainability of utilizing reclaimed domestic wastewater in urban households for toilet flushing and garden irrigation. It models a city characterized by water scarcity, using a coal-based electricity mix. Methods: Four approaches were compared: (0) Business-as-usual (BAU) alternative, where the central WW treatment plant effluent is discharged to nature; (1) central WW treatment and urban reuse of the effluent produced; (2) semi-distributed greywater treatment and reuse, at cluster scale; (3) Distributed greywater treatment and reuse, at building scale. Environmental life cycle assessment (LCA), social LCA (S-LCA), and life cycle costing (LCC) were applied to the system model of the above scenarios, with seawater desalination as the source for potable water. System boundaries include water supply, WW collection, and treatment facilities. Analytical hierarchy process (AHP), a multi-criteria decision analysis (MCDA) methodology, was integrated into the life cycle sustainability assessment (LCSA) framework as a means for weighting sustainability criteria through judgment elicitation from a panel of 20 experts. Results and discussion: Environmentally and socially, the two distributed alternatives perform better in most impact categories. Socially, semi-distributed (cluster scale) reuse is somewhat advantageous over the fully distributed alternative (building scale), due to the benefits of community engagement. Economically, the cluster-level scenario is the most preferable, while the building-scale scenario is the least preferable. A hierarchical representation of the problem’s criteria was constructed, according to the principals of AHP. Each criterion was weighted and those of extreme low importance were eliminated, while maintaining the integrity of the experts’ judgments. Weighted and aggregated sustainability scores revealed that cluster level reclamation, under modeled conditions, is the most sustainable option and the BAU scenario is the least sustainable. The other two alternatives, centralized and fully distributed reclamation, obtained similar intermediate scores. Conclusions: Distributed urban water reuse was found to be more sustainable than current practice. Different alternative solutions are advantageous in different ways, but overall, the reclamation and reuse of greywater at the cluster level seems to be the best option among the three reuse options examined in this assessment. AHP proved an effective method for aggregating the multiple sustainability criteria. The hierarchical view maintains transparency of all local weights while leading to the final weight vector.

@article{fe449af90b694de7975a9e3d1fd98996,
title = "Comparative life cycle sustainability assessment of urban water reuse at various centralization scales",
abstract = "Purpose: Population growth and urbanization lead to increasing water demand, putting significant pressure on natural water sources. The rising amounts of domestic wastewater (WW) in urban areas may be treated to serve as an alternative water source that may alleviate this pressure. This study examines sustainability of utilizing reclaimed domestic wastewater in urban households for toilet flushing and garden irrigation. It models a city characterized by water scarcity, using a coal-based electricity mix. Methods: Four approaches were compared: (0) Business-as-usual (BAU) alternative, where the central WW treatment plant effluent is discharged to nature; (1) central WW treatment and urban reuse of the effluent produced; (2) semi-distributed greywater treatment and reuse, at cluster scale; (3) Distributed greywater treatment and reuse, at building scale. Environmental life cycle assessment (LCA), social LCA (S-LCA), and life cycle costing (LCC) were applied to the system model of the above scenarios, with seawater desalination as the source for potable water. System boundaries include water supply, WW collection, and treatment facilities. Analytical hierarchy process (AHP), a multi-criteria decision analysis (MCDA) methodology, was integrated into the life cycle sustainability assessment (LCSA) framework as a means for weighting sustainability criteria through judgment elicitation from a panel of 20 experts. Results and discussion: Environmentally and socially, the two distributed alternatives perform better in most impact categories. Socially, semi-distributed (cluster scale) reuse is somewhat advantageous over the fully distributed alternative (building scale), due to the benefits of community engagement. Economically, the cluster-level scenario is the most preferable, while the building-scale scenario is the least preferable. A hierarchical representation of the problem{\textquoteright}s criteria was constructed, according to the principals of AHP. Each criterion was weighted and those of extreme low importance were eliminated, while maintaining the integrity of the experts{\textquoteright} judgments. Weighted and aggregated sustainability scores revealed that cluster level reclamation, under modeled conditions, is the most sustainable option and the BAU scenario is the least sustainable. The other two alternatives, centralized and fully distributed reclamation, obtained similar intermediate scores. Conclusions: Distributed urban water reuse was found to be more sustainable than current practice. Different alternative solutions are advantageous in different ways, but overall, the reclamation and reuse of greywater at the cluster level seems to be the best option among the three reuse options examined in this assessment. AHP proved an effective method for aggregating the multiple sustainability criteria. The hierarchical view maintains transparency of all local weights while leading to the final weight vector.",
keywords = "AHP, Clustering, Distributed reuse, Greywater, LCA, LCSA, MCDA, Non-potable, S-LCA, Wastewater",
author = "Tamar Opher and Eran Friedler and Aviad Shapira",
note = "Publisher Copyright: {\textcopyright} 2018, Springer-Verlag GmbH Germany, part of Springer Nature.",
year = "2019",
month = jul,
day = "1",
doi = "10.1007/s11367-018-1469-1",
language = "אנגלית",
volume = "24",
pages = "1319--1332",
journal = "International Journal of Life Cycle Assessment",
issn = "0948-3349",
publisher = "Springer Science + Business Media",
number = "7",

}

Closing the urban water loop: Integrated urban water and wastewater management for increasing sustainability – CLUWAL

Schutze M, Alex J, Snir O, Neta H, Gilboa Y, Vdov O et al. Closing the urban water loop: Integrated urban water and wastewater management for increasing sustainability – CLUWAL. In Proceedings of the Status Conference 2019 September 24 – 25, 2019 Dresden, Germany. 2019. p. 46-51
@inbook{75b1ad7259eb4f51b25095e653e41cde,
title = "Closing the urban water loop: Integrated urban water and wastewater management for increasing sustainability – CLUWAL",
author = "Manfred Schutze and Jens Alex and Ofer Snir and Hagit Neta and Yael Gilboa and Olga Vdov and Michelle Portman and Eran Friedler",
year = "2019",
language = "American English",
pages = "46--51",
booktitle = "Proceedings of the Status Conference 2019 September 24 – 25, 2019 Dresden, Germany",

}

התרומה הגדולה של המתקנים הקטנים

מימון ע, פרידלר ע, גרוס ע. התרומה הגדולה של המתקנים הקטנים. הנדסת מים. 2019;119:33-35.
 
לאחרונה נערך הכנס הבינלאומי ה-15 למערכות קטנות לטיפול במים ושפכים והכנס הבינלאומי ה-7 לתברואה מוכוונת משאבים. SWWS & ROS 2018. הם נערכו בטכניון בחיפה. המארגנים מסכמים את עיקרי המחקרים שהוצגו בהם.
@article{91f053f80d2b4e71bfd078a9a81391d3,
title = "התרומה הגדולה של המתקנים הקטנים",
abstract = "לאחרונה נערך הכנס הבינלאומי ה-15 למערכות קטנות לטיפול במים ושפכים והכנס הבינלאומי ה-7 לתברואה מוכוונת משאבים. SWWS & ROS 2018. הם נערכו בטכניון בחיפה. המארגנים מסכמים את עיקרי המחקרים שהוצגו בהם.",
author = "עדי מימון and ערן פרידלר and עמית גרוס",
year = "2019",
language = "עברית",
volume = "119",
pages = "33--35",
journal = "הנדסת מים",

}

ניהול אינטגרטיבי באגן ובאגם הכנרת

מרקל ד, עמר ד, שמיר א, גזית א, פרידלר ע, וינשטיין י. ניהול אינטגרטיבי באגן ובאגם הכנרת. הנדסת מים. 2019;119:14-18.
 
השינויים שהתחוללו בעשורים האחרונים בכנרת חייבו פעולות נוספות של ניהול האגם ואגן ההיקוות שלו. רשות המים בשילוב גופים נוספים יצרה מנגנון לניהול וניטור האגם הלאומי. בכמה מדדים מרכזיים כבר נרשמה הצלחה לפעילות זו.
@article{ab6a8bbfdf5146e48772717cc05060ea,
title = "ניהול אינטגרטיבי באגן ובאגם הכנרת",
abstract = "השינויים שהתחוללו בעשורים האחרונים בכנרת חייבו פעולות נוספות של ניהול האגם ואגן ההיקוות שלו. רשות המים בשילוב גופים נוספים יצרה מנגנון לניהול וניטור האגם הלאומי. בכמה מדדים מרכזיים כבר נרשמה הצלחה לפעילות זו.",
author = "דורון מרקל and דפנה עמר and אורי שמיר and אביטל גזית and ערן פרידלר and ישי וינשטיין",
year = "2019",
language = "עברית",
volume = "119",
pages = "14--18",
journal = "הנדסת מים",

}

2018

Tracking and simulation of gross solids transport in sewers

Penn R, Schuetze M, Jens A, Friedler E. Tracking and simulation of gross solids transport in sewers. Urban Water Journal. 2018 Jul 3;15(6):584-591. https://doi.org/10.1080/1573062X.2018.1529190
 

Investigation of various phenomena occurring in sewer systems is critical for increasing the sustainability of such systems. Such investigations also includes gross solids (GS) transport. GS transport may be affected by reduction of flows resulting from population decrease and/or reduced domestic water consumption. The present paper reports on the development of a model for describing GS velocity as a function of wastewater flow characteristics. The model was calibrated and validated with field experiments, in which two methods for GS tracking in sewers were developed, using small light sticks tracked by computerized light detector, and RFID based tracking. The model is integrated in a simulator which allows a description of the movement of individual GS through sewer systems. The developed model may assist in analysing existing sewer systems that are subject to changes in their input flows and prevent undesired failures (e.g. sedimentations, blockages, toxic gases) or in designing new systems.

@article{40bf62930f7949dbbafed32edd798d75,
title = "Tracking and simulation of gross solids transport in sewers",
abstract = "Investigation of various phenomena occurring in sewer systems is critical for increasing the sustainability of such systems. Such investigations also includes gross solids (GS) transport. GS transport may be affected by reduction of flows resulting from population decrease and/or reduced domestic water consumption. The present paper reports on the development of a model for describing GS velocity as a function of wastewater flow characteristics. The model was calibrated and validated with field experiments, in which two methods for GS tracking in sewers were developed, using small light sticks tracked by computerized light detector, and RFID based tracking. The model is integrated in a simulator which allows a description of the movement of individual GS through sewer systems. The developed model may assist in analysing existing sewer systems that are subject to changes in their input flows and prevent undesired failures (e.g. sedimentations, blockages, toxic gases) or in designing new systems.",
keywords = "Gross solids transport, in-sewer measurements, modelling",
author = "Roni Penn and Manfred Schuetze and Alex Jens and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2018, {\textcopyright} 2018 Informa UK Limited, trading as Taylor & Francis Group.",
year = "2018",
month = jul,
day = "3",
doi = "10.1080/1573062X.2018.1529190",
language = "אנגלית",
volume = "15",
pages = "584--591",
journal = "Urban Water Journal",
issn = "1573-062X",
publisher = "Taylor and Francis Ltd.",
number = "6",

}

A comparative social life cycle assessment of urban domestic water reuse alternatives

Opher T, Shapira A, Friedler E. A comparative social life cycle assessment of urban domestic water reuse alternatives. International Journal of Life Cycle Assessment. 2018 Jun 1;23(6):1315-1330. https://doi.org/10.1007/s11367-017-1356-1
 

Purpose: The social benefits and impacts of four alternative approaches to urban domestic non-potable water reuse were compared: (1) central wastewater treatment, no urban reuse. Reclaimed water is discharged to nature; (2) central wastewater treatment and urban reuse of the wastewater treatment plant’s tertiary effluent; (3) semi-distributed greywater treatment and reuse, at cluster scale (8 residential buildings); (4) distributed greywater treatment and reuse, within each apartment building. Methods: The impacts of the four aforementioned approaches to water reuse on three relevant stakeholders were investigated: public, community, and consumer. A hierarchical structure of impact categories and sub-categories under these stakeholder groups was established. Expert judgment elicitation was used to attribute weights to the social criteria, through an analytical hierarchy process (AHP). AHP is an established multi-criteria decision analysis method, based on series of pairwise comparisons. It was also used to evaluate impact intensities for both quantitative and qualitative social indicators. All expert judgements were integrated into an overall weight vector, and a comprehensive social score was calculated for each compared scenario. Results and discussion: Public commitment to water saving was ranked as the most important factor in assessing the social impacts of urban domestic reuse, with a weight of 29.6%. Two sub-categories of the community category ranked second: urban landscape and community engagement (12.6% and 12.0%, respectively). The two distributed alternatives are advantageous over the other two approaches in terms of water saving and urban landscape. The semi-distributed alternative has a significant benefit of community engagement, which the other three lack. The business-as-usual (BAU, no reuse) scenario scored highest in the categories: public equality, consumer health concerns, and consumption habits. Final scores for the compared scenarios indicate that central reuse is somewhat more socially beneficial than no urban reuse, but the two distributed alternatives are far better. Conclusions: In social life cycle assessment (SLCA) often quantitative and qualitative criteria/indicators exist side by side and their harmonious integration is challenging. The challenge arising is twofold: quantifying qualitative indicators and homogenizing all indicator evaluations into a uniform comparable scale. Both tasks were achieved in this study using the AHP. The AHP also successfully served as a platform for participatory processes of eliciting expert judgments regarding criteria weights and may be very useful for stakeholder participation in any social assessment. Regarding the case study—distributed urban water reuse was found to be socially beneficial, both in terms of promoting public commitment to conservation of natural water resources and in advancing community engagement.

@article{4301ae1ebb3a4e8eb4b5686d79fdf6db,
title = "A comparative social life cycle assessment of urban domestic water reuse alternatives",
abstract = "Purpose: The social benefits and impacts of four alternative approaches to urban domestic non-potable water reuse were compared: (1) central wastewater treatment, no urban reuse. Reclaimed water is discharged to nature; (2) central wastewater treatment and urban reuse of the wastewater treatment plant{\textquoteright}s tertiary effluent; (3) semi-distributed greywater treatment and reuse, at cluster scale (8 residential buildings); (4) distributed greywater treatment and reuse, within each apartment building. Methods: The impacts of the four aforementioned approaches to water reuse on three relevant stakeholders were investigated: public, community, and consumer. A hierarchical structure of impact categories and sub-categories under these stakeholder groups was established. Expert judgment elicitation was used to attribute weights to the social criteria, through an analytical hierarchy process (AHP). AHP is an established multi-criteria decision analysis method, based on series of pairwise comparisons. It was also used to evaluate impact intensities for both quantitative and qualitative social indicators. All expert judgements were integrated into an overall weight vector, and a comprehensive social score was calculated for each compared scenario. Results and discussion: Public commitment to water saving was ranked as the most important factor in assessing the social impacts of urban domestic reuse, with a weight of 29.6%. Two sub-categories of the community category ranked second: urban landscape and community engagement (12.6% and 12.0%, respectively). The two distributed alternatives are advantageous over the other two approaches in terms of water saving and urban landscape. The semi-distributed alternative has a significant benefit of community engagement, which the other three lack. The business-as-usual (BAU, no reuse) scenario scored highest in the categories: public equality, consumer health concerns, and consumption habits. Final scores for the compared scenarios indicate that central reuse is somewhat more socially beneficial than no urban reuse, but the two distributed alternatives are far better. Conclusions: In social life cycle assessment (SLCA) often quantitative and qualitative criteria/indicators exist side by side and their harmonious integration is challenging. The challenge arising is twofold: quantifying qualitative indicators and homogenizing all indicator evaluations into a uniform comparable scale. Both tasks were achieved in this study using the AHP. The AHP also successfully served as a platform for participatory processes of eliciting expert judgments regarding criteria weights and may be very useful for stakeholder participation in any social assessment. Regarding the case study—distributed urban water reuse was found to be socially beneficial, both in terms of promoting public commitment to conservation of natural water resources and in advancing community engagement.",
keywords = "AHP, Distributed wastewater treatment, Greywater, MCDA, Non potable reuse, Resource management, Source separation",
author = "Tamar Opher and Aviad Shapira and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2017, Springer-Verlag GmbH Germany.",
year = "2018",
month = jun,
day = "1",
doi = "10.1007/s11367-017-1356-1",
language = "אנגלית",
volume = "23",
pages = "1315--1330",
journal = "International Journal of Life Cycle Assessment",
issn = "0948-3349",
publisher = "Springer Science + Business Media",
number = "6",

}

Diurnal patterns of micropollutants concentrations in domestic greywater

Alfiya Y, Dubowski Y, Friedler E. Diurnal patterns of micropollutants concentrations in domestic greywater. Urban Water Journal. 2018 May 28;15(5):399-406. https://doi.org/10.1080/1573062X.2018.1483524
 

In recent years, much interest has been given to presence of micropollutants in municipal wastewater, some of which are suspected to be endocrine disruptors, toxic or carcinogenic. Much less attention has been paid to their presence in greywater. The present research studies the diurnal patterns of micropollutants in greywater and computes their daily loads. Monitoring was carried-out using auto-controlled sampling system, designed to overcome the erratic greywater generation. Two main generation periods were identified: morning (5:00–11:00) and evening-night (18:00–2:00), contributing about 20% and >50% of daily greywater discharge, respectively. Average specific daily greywater discharge was 57 L p−1d−1, which matches reported value for greywater generated by showers and washbasins in Israel. The most frequently detected micropollutants in this study were methylparben (preservative), galaxolide (fragrance) and oxybenzone (UV-filter), which are common ingredients in many personal care-products. Their daily loads were 2, 840, 1, 887 and 728 µg p−1d−1, respectively.

@article{9b5dca52e6c44d2885e6ce94ab602752,
title = "Diurnal patterns of micropollutants concentrations in domestic greywater",
abstract = "In recent years, much interest has been given to presence of micropollutants in municipal wastewater, some of which are suspected to be endocrine disruptors, toxic or carcinogenic. Much less attention has been paid to their presence in greywater. The present research studies the diurnal patterns of micropollutants in greywater and computes their daily loads. Monitoring was carried-out using auto-controlled sampling system, designed to overcome the erratic greywater generation. Two main generation periods were identified: morning (5:00–11:00) and evening-night (18:00–2:00), contributing about 20% and >50% of daily greywater discharge, respectively. Average specific daily greywater discharge was 57 L p−1d−1, which matches reported value for greywater generated by showers and washbasins in Israel. The most frequently detected micropollutants in this study were methylparben (preservative), galaxolide (fragrance) and oxybenzone (UV-filter), which are common ingredients in many personal care-products. Their daily loads were 2, 840, 1, 887 and 728 µg p−1d−1, respectively.",
keywords = "Greywater, daily loads, diurnal pattern, emerging micropollutants, personal care products",
author = "Yuval Alfiya and Yael Dubowski and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2018, {\textcopyright} 2018 Informa UK Limited, trading as Taylor & Francis Group.",
year = "2018",
month = may,
day = "28",
doi = "10.1080/1573062X.2018.1483524",
language = "אנגלית",
volume = "15",
pages = "399--406",
journal = "Urban Water Journal",
issn = "1573-062X",
publisher = "Taylor and Francis Ltd.",
number = "5",

}

Quantitative microbial risk analysis for various bacterial exposure scenarios involving greywater reuse for irrigation

Busgang A, Friedler E, Gilboa Y, Gross A. Quantitative microbial risk analysis for various bacterial exposure scenarios involving greywater reuse for irrigation. Water (Switzerland). 2018 Apr 2;10(4):413. https://doi.org/10.3390/w10040413
 

Greywater reuse can significantly reduce domestic water consumption. While the benefits are promising, risks are still under debate. Using a quantitative microbial risk-assessment model, we assessed the health risks associated with greywater reuse. The pathogens Salmonella enterica, Shigella spp., and Staphylococcus aureus were evaluated due to their possible prevalence in greywater and limited information regarding their potential risk with relation to greywater reuse for irrigation. Various exposure scenarios were investigated. Monte Carlo simulation was used and results were compared to the maximum "acceptable" limit of 10-6 disability-adjusted life years (DALY) set by the World Health Organization. Safe reuse was met for all worst-case exposure scenarios for Staphylococcus aureus, Salmonella enterica and Shigella spp. If their concentrations were kept below 10,000, 50 and 5 cfu/100 mL, respectively. For the best-practice (more realistic) scenarios, safe reuse was met for Staphylococcus aureus if its concentration was kept below 106 cfu/100 mL. Salmonella enterica met the safe reuse requirements if a maximum concentration of 500 cfu/100 mL was maintained and Shigella spp. if a maximum concentration was lower than 5 cfu/100 mL. Based on reported concentrations of these bacteria in greywater, proper treatment and disinfection are recommended.

@article{4200331f1ab34aefbc7ec69fac4a4299,
title = "Quantitative microbial risk analysis for various bacterial exposure scenarios involving greywater reuse for irrigation",
abstract = "Greywater reuse can significantly reduce domestic water consumption. While the benefits are promising, risks are still under debate. Using a quantitative microbial risk-assessment model, we assessed the health risks associated with greywater reuse. The pathogens Salmonella enterica, Shigella spp., and Staphylococcus aureus were evaluated due to their possible prevalence in greywater and limited information regarding their potential risk with relation to greywater reuse for irrigation. Various exposure scenarios were investigated. Monte Carlo simulation was used and results were compared to the maximum {"}acceptable{"} limit of 10-6 disability-adjusted life years (DALY) set by the World Health Organization. Safe reuse was met for all worst-case exposure scenarios for Staphylococcus aureus, Salmonella enterica and Shigella spp. If their concentrations were kept below 10,000, 50 and 5 cfu/100 mL, respectively. For the best-practice (more realistic) scenarios, safe reuse was met for Staphylococcus aureus if its concentration was kept below 106 cfu/100 mL. Salmonella enterica met the safe reuse requirements if a maximum concentration of 500 cfu/100 mL was maintained and Shigella spp. if a maximum concentration was lower than 5 cfu/100 mL. Based on reported concentrations of these bacteria in greywater, proper treatment and disinfection are recommended.",
keywords = "DALY, Greywater, Pathogen, QMRA, Risk assessment",
author = "Allison Busgang and Eran Friedler and Yael Gilboa and Amit Gross",
note = "Publisher Copyright: {\textcopyright} 2018 by the authors.",
year = "2018",
month = apr,
day = "2",
doi = "10.3390/w10040413",
language = "אנגלית",
volume = "10",
journal = "Water (Switzerland)",
issn = "2073-4441",
publisher = "MDPI Multidisciplinary Digital Publishing Institute",
number = "4",

}

Removal of Triclosan from treated wastewater by onsite V-UV/UV-C irradiation

Alfiya Y, Friedler E, Dubowski Y. Removal of Triclosan from treated wastewater by onsite V-UV/UV-C irradiation. In 15th IWA Int. Conf. on Small Water & Wastewater Systems. 2018
@inproceedings{c3a78b10866940f0a8887ebca531ee6b,
title = "Removal of Triclosan from treated wastewater by onsite V-UV/UV-C irradiation",
author = "Yuval Alfiya and Eran Friedler and Yael Dubowski",
year = "2018",
language = "American English",
booktitle = "15th IWA Int. Conf. on Small Water & Wastewater Systems",

}

2017

Photodegradation of micropollutants using V-UV/UV-C processes; Triclosan as a model compound

Alfiya Y, Friedler E, Westphal J, Olsson O, Dubowski Y. Photodegradation of micropollutants using V-UV/UV-C processes; Triclosan as a model compound. Science of the Total Environment. 2017 Dec 1;601-602:397-404. https://doi.org/10.1016/j.scitotenv.2017.05.172
 

Non-potable reuse of treated wastewater is becoming widespread as means to address growing water scarcity. Removal of micropollutants (MPs) from such water often requires advanced oxidation processes using [rad]OH radicals. [rad]OH can be generated in-situ via water photolysis under vacuum-UV (λ < 200 nm) irradiation. The aim of this study was to investigate the potential of unmasking V-UV radiation from low pressure Hg lamps (emitting at 185 and 254 nm), commonly used in decentralized treatment systems, for enhancing MPs removal efficiency. Triclosan, a biocide of limited biodegradability, served as a model compound for MPs that are not very biodegradable. Its degradation kinetics and identification of intermediate products were investigated under 254 nm and under combined 254/185 nm irradiation both in dry thin films and in aqueous solutions. In the latter, degradation was faster under combined 254/185 nm radiation, although the 185 nm radiation accounted for only 4% of the total UV light intensity. In contrast, triclosan photodegradation in dry film did not show significant differences between these irradiation wavelengths, suggesting that the enhanced degradation of dissolved triclosan under combined radiation is mainly due to oxidation by [rad]OH formed via water photolysis under V-UV. This conclusion was supported by slower TCS degradation in aqueous solution when methanol was added as [rad]OH scavenger. Under both irradiation types (254, 254/185 nm) three transformation products (TPs) were identified: 2,8-dichlorodibenzo-p-dioxin, 5-chloro-2-(4- or 2-chlorophenoxy)phenol, and 2-hydroxy-8-chlorodibenzodioxin. In-silico QSAR toxicity assessment predicted potential toxicity and moderate-to-low biodegradability of these TPs. Removal of these TPs was faster under 254/185 nm irradiation. Considering the low cost, simple operation (i.e. no chemicals addition) and small size of such low-pressure mercury lamps, this is a promising direction. Further investigation of the process in flow-through reactors and real wastewater/greywater effluent is needed for its future implementation in small on-site systems for post-treatment of persistent pollutants.

@article{695af547c0714c4796270a87f3612c3d,
title = "Photodegradation of micropollutants using V-UV/UV-C processes; Triclosan as a model compound",
abstract = "Non-potable reuse of treated wastewater is becoming widespread as means to address growing water scarcity. Removal of micropollutants (MPs) from such water often requires advanced oxidation processes using [rad]OH radicals. [rad]OH can be generated in-situ via water photolysis under vacuum-UV (λ < 200 nm) irradiation. The aim of this study was to investigate the potential of unmasking V-UV radiation from low pressure Hg lamps (emitting at 185 and 254 nm), commonly used in decentralized treatment systems, for enhancing MPs removal efficiency. Triclosan, a biocide of limited biodegradability, served as a model compound for MPs that are not very biodegradable. Its degradation kinetics and identification of intermediate products were investigated under 254 nm and under combined 254/185 nm irradiation both in dry thin films and in aqueous solutions. In the latter, degradation was faster under combined 254/185 nm radiation, although the 185 nm radiation accounted for only 4% of the total UV light intensity. In contrast, triclosan photodegradation in dry film did not show significant differences between these irradiation wavelengths, suggesting that the enhanced degradation of dissolved triclosan under combined radiation is mainly due to oxidation by [rad]OH formed via water photolysis under V-UV. This conclusion was supported by slower TCS degradation in aqueous solution when methanol was added as [rad]OH scavenger. Under both irradiation types (254, 254/185 nm) three transformation products (TPs) were identified: 2,8-dichlorodibenzo-p-dioxin, 5-chloro-2-(4- or 2-chlorophenoxy)phenol, and 2-hydroxy-8-chlorodibenzodioxin. In-silico QSAR toxicity assessment predicted potential toxicity and moderate-to-low biodegradability of these TPs. Removal of these TPs was faster under 254/185 nm irradiation. Considering the low cost, simple operation (i.e. no chemicals addition) and small size of such low-pressure mercury lamps, this is a promising direction. Further investigation of the process in flow-through reactors and real wastewater/greywater effluent is needed for its future implementation in small on-site systems for post-treatment of persistent pollutants.",
keywords = "Advanced oxidation process, Decentralized wastewater treatment, Micropollutants, Transformation products, Triclosan, Vacuum ultra-violet",
author = "Yuval Alfiya and Eran Friedler and Janin Westphal and Oliver Olsson and Yael Dubowski",
note = "Publisher Copyright: {\textcopyright} 2017 Elsevier B.V.",
year = "2017",
month = dec,
day = "1",
doi = "10.1016/j.scitotenv.2017.05.172",
language = "אנגלית",
volume = "601-602",
pages = "397--404",
journal = "Science of the Total Environment",
issn = "0048-9697",
publisher = "Elsevier",

}

Quality of roof-harvested rainwater as a function of environmental and air pollution factors in a coastal Mediterranean City (Haifa, Israel)

Friedler E, Gilboa Y, Muklada H. Quality of roof-harvested rainwater as a function of environmental and air pollution factors in a coastal Mediterranean City (Haifa, Israel). Water (Switzerland). 2017 Nov 16;9(11):896. https://doi.org/10.3390/w9110896
 

The quality of roof-harvested rainwater in a Mediterranean climate, which is characterised by dry summers and erratic wet winters, was studied. The effects of environmental factors (rain depth, length of dry period between consecutive rain events, time since the beginning of the rainy season, roof type, wind speed, and wind direction) and air pollution parameters (O3, SO2, NO2, NO, PM2.5, and PM2.5-10) on roof runoff quality were studied. Three roofs of three common types (concrete, steel sheets, and tiles) were constructed. Roof-generated runoff was collected over two rainy seasons ( > 50 rain events) and were analysed for presence of metals, chemical and physical constituents, and faecal coliforms (a total of 23 parameters). Rain depth and runoff volume from each roof were recorded for each rain event. Most parameters examined complied with the Israeli potable water regulations. A stepwise multivariate linear regression established a significant effect of roof type on runoff pollutant concentrations, especially for ones generated by the roof material itself (e.g., Ca from the concrete roof and Zn from roof tiles). A significant effect of various air pollutants on the quality of roof-runoff water was found, as explained by rain washing off pollutants that accumulated in the atmosphere during the antecedent dry period. Both O3 and PM2.5-10 affected 17 quality parameters each. Rain depth affected only four out of the 23 water quality variables. In contrast, the length of the dry period between consecutive rain events was an important factor, affecting 12 roof-runoff quality variables.

@article{0534064a153e421ca0de213b1ec494c5,
title = "Quality of roof-harvested rainwater as a function of environmental and air pollution factors in a coastal Mediterranean City (Haifa, Israel)",
abstract = "The quality of roof-harvested rainwater in a Mediterranean climate, which is characterised by dry summers and erratic wet winters, was studied. The effects of environmental factors (rain depth, length of dry period between consecutive rain events, time since the beginning of the rainy season, roof type, wind speed, and wind direction) and air pollution parameters (O3, SO2, NO2, NO, PM2.5, and PM2.5-10) on roof runoff quality were studied. Three roofs of three common types (concrete, steel sheets, and tiles) were constructed. Roof-generated runoff was collected over two rainy seasons ( > 50 rain events) and were analysed for presence of metals, chemical and physical constituents, and faecal coliforms (a total of 23 parameters). Rain depth and runoff volume from each roof were recorded for each rain event. Most parameters examined complied with the Israeli potable water regulations. A stepwise multivariate linear regression established a significant effect of roof type on runoff pollutant concentrations, especially for ones generated by the roof material itself (e.g., Ca from the concrete roof and Zn from roof tiles). A significant effect of various air pollutants on the quality of roof-runoff water was found, as explained by rain washing off pollutants that accumulated in the atmosphere during the antecedent dry period. Both O3 and PM2.5-10 affected 17 quality parameters each. Rain depth affected only four out of the 23 water quality variables. In contrast, the length of the dry period between consecutive rain events was an important factor, affecting 12 roof-runoff quality variables.",
keywords = "Air pollution, Environmental factors, Mediterranean climate, Rainwater harvesting, Roof runoff quality",
author = "Eran Friedler and Yael Gilboa and Hussein Muklada",
note = "Publisher Copyright: {\textcopyright} 2017 by the authors.",
year = "2017",
month = nov,
day = "16",
doi = "10.3390/w9110896",
language = "אנגלית",
volume = "9",
journal = "Water (Switzerland)",
issn = "2073-4441",
publisher = "MDPI Multidisciplinary Digital Publishing Institute",
number = "11",

}

Sorption and biodegradation of propylparaben in greywater by aerobic attached-growth biomass

Song H, Alfiya Y, Dubowski Y, Friedler E. Sorption and biodegradation of propylparaben in greywater by aerobic attached-growth biomass. Science of the Total Environment. 2017 Nov 15;598:925-930. https://doi.org/10.1016/j.scitotenv.2017.04.032
 

Greywater (GW) is becoming an important alternative water source for non-potable purposes, but requires treatment to remove contaminants, including micropollutants that in GW mainly originate from personal care products. Biofilters are commonly used for onsite GW treatment, but there are still significant knowledge gaps regarding their ability and mechanism of micropollutants removal. This study investigates the removal of propylparaben (PPB) by aerobic attached-growth biomass, quantifying the kinetics and the interplay between sorption and biodegradation. The ability of biomass, collected from a pilot scale biofilter treating real GW, to eliminate PPB from both synthetic greywater (SGW) and deionized (DI) water was studied in laboratory batch experiments. Elimination of PPB was found to proceed via sorption to biomass followed by biodegradation. Sorption of PPB by biomass in SGW and in DI water exhibited similar kinetics, fitting Langmuir isotherm with the maximum adsorbed amount of 9.8 mgPPB gbiomass− 1. PPB biodegradation exhibited first-order kinetics in both SGW and DI water, with a 30 h lag-phase in SGW and no lag-phase in DI water. This difference is attributed to presence of readily-biodegradable organic matter in the SGW. Actual PPB degradation rate in both cases (excluding the lag phase in SGW) was very similar, 62 mgPPB gbiomass− 1 d− 1, yielding almost full mineralization. These findings show the relative contribution of the major processes involved in PPB elimination by biofilters and can be applied for designing GW treatment units.

@article{52c975c8507743e69d854d899c093b51,
title = "Sorption and biodegradation of propylparaben in greywater by aerobic attached-growth biomass",
abstract = "Greywater (GW) is becoming an important alternative water source for non-potable purposes, but requires treatment to remove contaminants, including micropollutants that in GW mainly originate from personal care products. Biofilters are commonly used for onsite GW treatment, but there are still significant knowledge gaps regarding their ability and mechanism of micropollutants removal. This study investigates the removal of propylparaben (PPB) by aerobic attached-growth biomass, quantifying the kinetics and the interplay between sorption and biodegradation. The ability of biomass, collected from a pilot scale biofilter treating real GW, to eliminate PPB from both synthetic greywater (SGW) and deionized (DI) water was studied in laboratory batch experiments. Elimination of PPB was found to proceed via sorption to biomass followed by biodegradation. Sorption of PPB by biomass in SGW and in DI water exhibited similar kinetics, fitting Langmuir isotherm with the maximum adsorbed amount of 9.8 mgPPB gbiomass− 1. PPB biodegradation exhibited first-order kinetics in both SGW and DI water, with a 30 h lag-phase in SGW and no lag-phase in DI water. This difference is attributed to presence of readily-biodegradable organic matter in the SGW. Actual PPB degradation rate in both cases (excluding the lag phase in SGW) was very similar, 62 mgPPB gbiomass− 1 d− 1, yielding almost full mineralization. These findings show the relative contribution of the major processes involved in PPB elimination by biofilters and can be applied for designing GW treatment units.",
keywords = "Greywater, Micropollutants, Personal care products, Propylparaben, Transesterification",
author = "Haihong Song and Yuval Alfiya and Yael Dubowski and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2017 Elsevier B.V.",
year = "2017",
month = nov,
day = "15",
doi = "10.1016/j.scitotenv.2017.04.032",
language = "אנגלית",
volume = "598",
pages = "925--930",
journal = "Science of the Total Environment",
issn = "0048-9697",
publisher = "Elsevier",

}

Simulation method for stochastic generation of domestic wastewater discharges and the effect of greywater reuse on gross solid transport

Penn R, Schütze M, Gorfine M, Friedler E. Simulation method for stochastic generation of domestic wastewater discharges and the effect of greywater reuse on gross solid transport. Urban Water Journal. 2017 Sep 14;14(8):846-852. https://doi.org/10.1080/1573062X.2017.1279188
 

Together with significant water saving, due to lower wastewater discharges, greywater reuse (GWR) may also increase the impacts of faecal matter and other gross solids (GS) on sewer systems (sedimentation, blocking). Modelling and assessments of these effects require detailed descriptions of individual domestic wastewater streams. A novel stochastic methodology to generate such streams was developed and validated. The generator was developed while considering dependencies between in-house water-use events, and their varying degree of elasticity. These generated streams served as input to a sewer model, where scenarios of GWR were simulated and their effects on GS transport were examined. Extensive GWR decreases GS movement mostly in upstream links. Nevertheless, transient high flows, characterising these links, may move stationary GS and prevent blockages. The developed generator can be adopted to other sewer-related studies. Intelligent implementation of the results can assist in introducing GWR, or other water saving measures to the urban sector.

@article{0beb49e430534a0b99cdaf0999d9ec18,
title = "Simulation method for stochastic generation of domestic wastewater discharges and the effect of greywater reuse on gross solid transport",
abstract = "Together with significant water saving, due to lower wastewater discharges, greywater reuse (GWR) may also increase the impacts of faecal matter and other gross solids (GS) on sewer systems (sedimentation, blocking). Modelling and assessments of these effects require detailed descriptions of individual domestic wastewater streams. A novel stochastic methodology to generate such streams was developed and validated. The generator was developed while considering dependencies between in-house water-use events, and their varying degree of elasticity. These generated streams served as input to a sewer model, where scenarios of GWR were simulated and their effects on GS transport were examined. Extensive GWR decreases GS movement mostly in upstream links. Nevertheless, transient high flows, characterising these links, may move stationary GS and prevent blockages. The developed generator can be adopted to other sewer-related studies. Intelligent implementation of the results can assist in introducing GWR, or other water saving measures to the urban sector.",
keywords = "Diurnal patterns, greywater reuse, gross solids, sewers, stochastic generator",
author = "Roni Penn and Manfred Sch{\"u}tze and Malka Gorfine and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2017 Informa UK Limited, trading as Taylor & Francis Group.",
year = "2017",
month = sep,
day = "14",
doi = "10.1080/1573062X.2017.1279188",
language = "אנגלית",
volume = "14",
pages = "846--852",
journal = "Urban Water Journal",
issn = "1573-062X",
publisher = "Taylor and Francis Ltd.",
number = "8",

}

Impacts of onsite greywater reuse on wastewater systems

Penn R, Schütze M, Alex J, Friedler E. Impacts of onsite greywater reuse on wastewater systems. Water Science and Technology. 2017 Apr;75(8):1862-1872. https://doi.org/10.2166/wst.2017.057
 

Together with significant water savings that onsite greywater reuse (GWR) may provide, it may also affect the performance of urban sewer systems and wastewater treatment plants (WWTPs). In order to examine these effects, an integrated stochastic simulation system for GWR in urban areas was developed. The model includes stochastic generators of domestic wastewater streams and gross solids (GSs), a sewer network model which includes hydrodynamic simulation and a GS transport module, and a dynamic process model of the WWTP. The developed model was applied to a case study site in Israel. For the validation of the sewer simulator, field experiments in a real sewer segment were conducted. The paper presents the integration and implementation of these modules and depicts the results of the effects of various GWR scenarios on GS movement in sewers and on the performance of the WWTP.

@article{7473303aa74e422dade74137173616c3,
title = "Impacts of onsite greywater reuse on wastewater systems",
abstract = "Together with significant water savings that onsite greywater reuse (GWR) may provide, it may also affect the performance of urban sewer systems and wastewater treatment plants (WWTPs). In order to examine these effects, an integrated stochastic simulation system for GWR in urban areas was developed. The model includes stochastic generators of domestic wastewater streams and gross solids (GSs), a sewer network model which includes hydrodynamic simulation and a GS transport module, and a dynamic process model of the WWTP. The developed model was applied to a case study site in Israel. For the validation of the sewer simulator, field experiments in a real sewer segment were conducted. The paper presents the integration and implementation of these modules and depicts the results of the effects of various GWR scenarios on GS movement in sewers and on the performance of the WWTP.",
keywords = "Greywater reuse, Gross solid transport, Sewers, Stochastic diurnal patterns, Wastewater treatment plants",
author = "Roni Penn and Manfred Sch{\"u}tze and Jens Alex and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} IWA Publishing 2017.",
year = "2017",
month = apr,
doi = "10.2166/wst.2017.057",
language = "אנגלית",
volume = "75",
pages = "1862--1872",
journal = "Water Science and Technology",
issn = "0273-1223",
publisher = "IWA Publishing",
number = "8",

}

Corrigendum to “Urban rainwater harvesting systems: Research, implementation and future perspectives” [Water Research 115 (2017) 195–209](S0043135417301483)(10.1016/j.watres.2017.02.056)

Campisano A, Butler D, Ward S, Burns MJ, Friedler E, DeBusk K et al. Corrigendum to “Urban rainwater harvesting systems: Research, implementation and future perspectives” [Water Research 115 (2017) 195–209](S0043135417301483)(10.1016/j.watres.2017.02.056). Water Research. 2017;121:386. https://doi.org/10.1016/j.watres.2017.06.002
 

The authors regret that the original author affiliation information was incorrect. The correct affiliation for Dr. Kathy DeBusk is as follows: Department of Biological and Environmental Sciences, Longwood University, 201 High Street, Farmville, VA 23909, USA. The authors would like to apologise for any inconvenience caused.

@article{a1e6207c0e9f4ec196a0180cc1e43092,
title = "Corrigendum to “Urban rainwater harvesting systems: Research, implementation and future perspectives” [Water Research 115 (2017) 195–209](S0043135417301483)(10.1016/j.watres.2017.02.056)",
abstract = "The authors regret that the original author affiliation information was incorrect. The correct affiliation for Dr. Kathy DeBusk is as follows: Department of Biological and Environmental Sciences, Longwood University, 201 High Street, Farmville, VA 23909, USA. The authors would like to apologise for any inconvenience caused.",
author = "Alberto Campisano and David Butler and Sarah Ward and Burns, {Matthew J.} and Eran Friedler and Kathy DeBusk and Fisher-Jeffes, {Lloyd N.} and Enedir Ghisi and Ataur Rahman and Hiroaki Furumai and Mooyoung Han",
note = "Publisher Copyright: {\textcopyright} 2017",
year = "2017",
doi = "10.1016/j.watres.2017.06.002",
language = "אנגלית",
volume = "121",
pages = "386",
journal = "Water Research",
issn = "0043-1354",
publisher = "Elsevier Ltd.",

}

Greywater reuse - Assessment of the health risk induced by Legionella pneumophila

Blanky M, Sharaby Y, Rodríguez-Martínez S, Halpern M, Friedler E. Greywater reuse - Assessment of the health risk induced by Legionella pneumophila. Water Research. 2017;125:410-417. https://doi.org/10.1016/j.watres.2017.08.068
 

Greywater (GW), domestic wastewater excluding the streams generated by toilets and kitchens, can serve as an alternative water source. The main options for GW reuse are toilet flushing and garden irrigation, both generating aerosols. These may transmit inhalable pathogens like Legionella and present a potential health risk. This study quantified the health risk that may arise from inhalation of Legionella-contaminated aerosols due to non-potable GW reuse. Data on Legionella concentrations in potable water and GW was collected. Then, Quantitative Microbial Risk Assessment (QMRA) was performed for two possible exposure scenarios: garden irrigation and toilet flushing. This was performed while considering Legionella seasonality. In order to determine the safety of GW reuse regarding Legionella transmission, the obtained results were compared with estimated tolerable risk levels of infection and of disease. Both limits were expressed as Disability-Adjusted Life Years index (DALY) being 10−4 and 10−5, respectively. The QMRA revealed that the annual risk associated with reuse of treated and chlorinated GW for garden irrigation and toilet flushing was not significantly higher than the risk associated with using potable water for the same two purposes. In all studied scenarios, the health risk stemming from reusing treated and chlorinated GW was acceptable regarding Legionella infection. In contrast, reuse of untreated or treated but unchlorinated GW should not be practiced, as these are associated with significantly higher health risks.

@article{26e84856f4e544969f8d2afaed231f9c,
title = "Greywater reuse - Assessment of the health risk induced by Legionella pneumophila",
abstract = "Greywater (GW), domestic wastewater excluding the streams generated by toilets and kitchens, can serve as an alternative water source. The main options for GW reuse are toilet flushing and garden irrigation, both generating aerosols. These may transmit inhalable pathogens like Legionella and present a potential health risk. This study quantified the health risk that may arise from inhalation of Legionella-contaminated aerosols due to non-potable GW reuse. Data on Legionella concentrations in potable water and GW was collected. Then, Quantitative Microbial Risk Assessment (QMRA) was performed for two possible exposure scenarios: garden irrigation and toilet flushing. This was performed while considering Legionella seasonality. In order to determine the safety of GW reuse regarding Legionella transmission, the obtained results were compared with estimated tolerable risk levels of infection and of disease. Both limits were expressed as Disability-Adjusted Life Years index (DALY) being 10−4 and 10−5, respectively. The QMRA revealed that the annual risk associated with reuse of treated and chlorinated GW for garden irrigation and toilet flushing was not significantly higher than the risk associated with using potable water for the same two purposes. In all studied scenarios, the health risk stemming from reusing treated and chlorinated GW was acceptable regarding Legionella infection. In contrast, reuse of untreated or treated but unchlorinated GW should not be practiced, as these are associated with significantly higher health risks.",
keywords = "DALY, Greywater reuse, Health risk assessment, Legionella pneumophila, QMRA",
author = "Marina Blanky and Yehonatan Sharaby and Sara Rodr{\'i}guez-Mart{\'i}nez and Malka Halpern and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2017 Elsevier Ltd",
year = "2017",
doi = "10.1016/j.watres.2017.08.068",
language = "אנגלית",
volume = "125",
pages = "410--417",
journal = "Water Research",
issn = "0043-1354",
publisher = "Elsevier Ltd.",

}

Urban rainwater harvesting systems: Research, implementation and future perspectives

Campisano A, Butler D, Ward S, Burns MJ, Friedler E, DeBusk K et al. Urban rainwater harvesting systems: Research, implementation and future perspectives. Water Research. 2017;115:195-209. https://doi.org/10.1016/j.watres.2017.02.056
 

While the practice of rainwater harvesting (RWH) can be traced back millennia, the degree of its modern implementation varies greatly across the world, often with systems that do not maximize potential benefits. With a global focus, the pertinent practical, theoretical and social aspects of RWH are reviewed in order to ascertain the state of the art. Avenues for future research are also identified. A major finding is that the degree of RWH systems implementation and the technology selection are strongly influenced by economic constraints and local regulations. Moreover, despite design protocols having been set up in many countries, recommendations are still often organized only with the objective of conserving water without considering other potential benefits associated with the multiple-purpose nature of RWH. It is suggested that future work on RWH addresses three priority challenges. Firstly, more empirical data on system operation is needed to allow improved modelling by taking into account multiple objectives of RWH systems. Secondly, maintenance aspects and how they may impact the quality of collected rainwater should be explored in the future as a way to increase confidence on rainwater use. Finally, research should be devoted to the understanding of how institutional and socio-political support can be best targeted to improve system efficacy and community acceptance.

@article{def9f3f46305427290e124353aa15955,
title = "Urban rainwater harvesting systems: Research, implementation and future perspectives",
abstract = "While the practice of rainwater harvesting (RWH) can be traced back millennia, the degree of its modern implementation varies greatly across the world, often with systems that do not maximize potential benefits. With a global focus, the pertinent practical, theoretical and social aspects of RWH are reviewed in order to ascertain the state of the art. Avenues for future research are also identified. A major finding is that the degree of RWH systems implementation and the technology selection are strongly influenced by economic constraints and local regulations. Moreover, despite design protocols having been set up in many countries, recommendations are still often organized only with the objective of conserving water without considering other potential benefits associated with the multiple-purpose nature of RWH. It is suggested that future work on RWH addresses three priority challenges. Firstly, more empirical data on system operation is needed to allow improved modelling by taking into account multiple objectives of RWH systems. Secondly, maintenance aspects and how they may impact the quality of collected rainwater should be explored in the future as a way to increase confidence on rainwater use. Finally, research should be devoted to the understanding of how institutional and socio-political support can be best targeted to improve system efficacy and community acceptance.",
keywords = "Rainwater harvesting, Stormwater management, Sustainable urban water systems, Water conservation, Water efficiency",
author = "Alberto Campisano and David Butler and Sarah Ward and Burns, {Matthew J.} and Eran Friedler and Kathy DeBusk and Fisher-Jeffes, {Lloyd N.} and Enedir Ghisi and Ataur Rahman and Hiroaki Furumai and Mooyoung Han",
note = "Publisher Copyright: {\textcopyright} 2017",
year = "2017",
doi = "10.1016/j.watres.2017.02.056",
language = "אנגלית",
volume = "115",
pages = "195--209",
journal = "Water Research",
issn = "0043-1354",
publisher = "Elsevier Ltd.",

}

השפעות של השקיית גינות במים אפורים

גרוס ע, אלפיה י, סקלרץ מ, פרידלר ע. השפעות של השקיית גינות במים אפורים. מים והשקיה: ירחון ארגון עובדי המים. 2017;549:40-42.
 
לאורך שבע שנים נבדקה ההשפעה של תכונות הקרקע ב-20 חצרות בהן הגינות מושקות במים אפורים, המטופלים במערכות מסוג אגנים ירוקים אנכיים מסוחררים. בשורה התחתונה לא נצפו שינויים חריגים בהרכב או בתכולת הקרקע המושקית. (מתוך המאמר)
@article{78e829a2ffb84c37ae463f6d6ebf1ff6,
title = "השפעות של השקיית גינות במים אפורים",
abstract = "לאורך שבע שנים נבדקה ההשפעה של תכונות הקרקע ב-20 חצרות בהן הגינות מושקות במים אפורים, המטופלים במערכות מסוג אגנים ירוקים אנכיים מסוחררים. בשורה התחתונה לא נצפו שינויים חריגים בהרכב או בתכולת הקרקע המושקית. (מתוך המאמר)",
author = "עמית גרוס and יובל אלפיה and מנחם סקלרץ and ערן פרידלר",
year = "2017",
language = "עברית",
volume = "549",
pages = "40--42",
journal = "מים והשקיה: ירחון ארגון עובדי המים",
issn = "0333-8835",

}

2016

Assessment of atmospheric moisture harvesting by direct cooling

Gido B, Friedler E, Broday DM. Assessment of atmospheric moisture harvesting by direct cooling. Atmospheric Research. 2016 Dec 15;182:156-162. https://doi.org/10.1016/j.atmosres.2016.07.029
 

The enormous amount of water vapor present in the atmosphere may serve as a potential water resource. An index is proposed for assessing the feasibility and energy requirements of atmospheric moisture harvesting by a direct cooling process. A climate-based analysis of different locations reveals the global potential of this process. We demonstrate that the Moisture Harvesting Index (MHI) can be used for assessing the energy requirements of atmospheric moisture harvesting. The efficiency of atmospheric moisture harvesting is highly weather and climate dependent, with the smallest estimated energy requirement found at the tropical regions of the Philippines (0.23 kW/L). Less favorable locations have much higher energy demands for the operation of an atmospheric moisture harvesting device. In such locations, using the MHI to select the optimal operation time periods (during the day and the year) can reduce the specific energy requirements of the process dramatically. Still, using current technology the energy requirement of atmospheric moisture harvesting by a direct air cooling process is significantly higher than of desalination by reverse osmosis.

@article{1ad4b0b25d15419eaaf86afc0e514cac,
title = "Assessment of atmospheric moisture harvesting by direct cooling",
abstract = "The enormous amount of water vapor present in the atmosphere may serve as a potential water resource. An index is proposed for assessing the feasibility and energy requirements of atmospheric moisture harvesting by a direct cooling process. A climate-based analysis of different locations reveals the global potential of this process. We demonstrate that the Moisture Harvesting Index (MHI) can be used for assessing the energy requirements of atmospheric moisture harvesting. The efficiency of atmospheric moisture harvesting is highly weather and climate dependent, with the smallest estimated energy requirement found at the tropical regions of the Philippines (0.23 kW/L). Less favorable locations have much higher energy demands for the operation of an atmospheric moisture harvesting device. In such locations, using the MHI to select the optimal operation time periods (during the day and the year) can reduce the specific energy requirements of the process dramatically. Still, using current technology the energy requirement of atmospheric moisture harvesting by a direct air cooling process is significantly higher than of desalination by reverse osmosis.",
keywords = "Ambient vapor condensation, Atmospheric moisture, Atmospheric water generators, Humidity harvesting",
author = "Ben Gido and Eran Friedler and Broday, {David M.}",
note = "Publisher Copyright: {\textcopyright} 2016 Elsevier B.V.",
year = "2016",
month = dec,
day = "15",
doi = "10.1016/j.atmosres.2016.07.029",
language = "אנגלית",
volume = "182",
pages = "156--162",
journal = "Atmospheric Research",
issn = "0169-8095",
publisher = "Elsevier BV",

}

Stochastic modelling of the hydraulic performance of an onsite rainwater harvesting system in Mediterranean climate

Muklada H, Gilboa Y, Friedler E. Stochastic modelling of the hydraulic performance of an onsite rainwater harvesting system in Mediterranean climate. Water Science and Technology: Water Supply. 2016 Dec;16(6):1614-1623. https://doi.org/10.2166/ws.2016.082
 

The performance of onsite rainwater harvesting (RWH) system in Mediterranean climate was assessed. A stochastic model quantifying the necessary storage, as a function of rainfall (frequency, depth), roof area, residents' number, specific water use (toilet flushing, laundry) and the required efficiency was developed. Two performance indicators were calculated: Water saving efficiency (RSE) - proportion of water used supplied by the RWH system; and rainwater use efficiency (RUE) - proportion of rainwater actually used. The maximum storage capacity and WSE decreased with increasing number of residents for a given roof area, and with an increasing roof area for constant number of residents. For variable storage volume, RUE increased with increasing storage capacity and reached a maximum with an increase in residents' number and a decrease in the roof area. The model enables to determine WSE and RUE for specific storage volumes or to determine the desired WSE and calculate the necessary storage.

@article{412e32439f5d41399f0f0491e82be975,
title = "Stochastic modelling of the hydraulic performance of an onsite rainwater harvesting system in Mediterranean climate",
abstract = "The performance of onsite rainwater harvesting (RWH) system in Mediterranean climate was assessed. A stochastic model quantifying the necessary storage, as a function of rainfall (frequency, depth), roof area, residents' number, specific water use (toilet flushing, laundry) and the required efficiency was developed. Two performance indicators were calculated: Water saving efficiency (RSE) - proportion of water used supplied by the RWH system; and rainwater use efficiency (RUE) - proportion of rainwater actually used. The maximum storage capacity and WSE decreased with increasing number of residents for a given roof area, and with an increasing roof area for constant number of residents. For variable storage volume, RUE increased with increasing storage capacity and reached a maximum with an increase in residents' number and a decrease in the roof area. The model enables to determine WSE and RUE for specific storage volumes or to determine the desired WSE and calculate the necessary storage.",
keywords = "Alternative water source, Mediterranean climate, Rainwater harvesting, Stochastic modelling, Water saving",
author = "H. Muklada and Y. Gilboa and E. Friedler",
note = "Publisher Copyright: {\textcopyright} IWA Publishing 2016.",
year = "2016",
month = dec,
doi = "10.2166/ws.2016.082",
language = "אנגלית",
volume = "16",
pages = "1614--1623",
journal = "Water Science and Technology: Water Supply",
issn = "1606-9749",
publisher = "IWA Publishing",
number = "6",

}

Comparative LCA of decentralized wastewater treatment alternatives for non-potable urban reuse

Opher T, Friedler E. Comparative LCA of decentralized wastewater treatment alternatives for non-potable urban reuse. Journal of Environmental Management. 2016 Nov 1;182:464-476. https://doi.org/10.1016/j.jenvman.2016.07.080
 

Municipal wastewater (WW) effluent represents a reliable and significant source for reclaimed water, very much needed nowadays. Water reclamation and reuse has become an attractive option for conserving and extending available water sources. The decentralized approach to domestic WW treatment benefits from the advantages of source separation, which makes available simple small-scale systems and on-site reuse, which can be constructed on a short time schedule and occasionally upgraded with new technological developments. In this study we perform a Life Cycle Assessment to compare between the environmental impacts of four alternatives for a hypothetical city's water-wastewater service system. The baseline alternative is the most common, centralized approach for WW treatment, in which WW is conveyed to and treated in a large wastewater treatment plant (WWTP) and is then discharged to a stream. The three alternatives represent different scales of distribution of the WW treatment phase, along with urban irrigation and domestic non-potable water reuse (toilet flushing). The first alternative includes centralized treatment at a WWTP, with part of the reclaimed WW (RWW) supplied back to the urban consumers. The second and third alternatives implement de-centralized greywater (GW) treatment with local reuse, one at cluster level (320 households) and one at building level (40 households). Life cycle impact assessment results show a consistent disadvantage of the prevailing centralized approach under local conditions in Israel, where seawater desalination is the marginal source of water supply. The alternative of source separation and GW reuse at cluster level seems to be the most preferable one, though its environmental performance is only slightly better than GW reuse at building level. Centralized WW treatment with urban reuse of WWTP effluents is not advantageous over decentralized treatment of GW because the supply of RWW back to consumers is very costly in materials and energy. Electricity is a major driver of the impacts in most categories, pertaining mostly to potable water production and supply. Infrastructure was found to have a notable effect on metal depletion, human toxicity and freshwater and marine ecotoxicity. Sensitivity to major model parameters was analyzed. A shift to a larger share of renewable energy sources in the electricity mix results in a dramatic improvement in most impact categories. Switching to a mix of water sources, rather than the marginal source, leads to a significant reduction in most impacts. It is concluded that under the conditions tested, a decentralized approach to urban wastewater management is environmentally preferable to the common centralized system. It is worth exploring such options under different conditions as well, in cases which new urban infrastructure is planned or replacement of old infrastructure is required.

@article{4e0f9b5fa0744303b1f0373193f6e9fc,
title = "Comparative LCA of decentralized wastewater treatment alternatives for non-potable urban reuse",
abstract = "Municipal wastewater (WW) effluent represents a reliable and significant source for reclaimed water, very much needed nowadays. Water reclamation and reuse has become an attractive option for conserving and extending available water sources. The decentralized approach to domestic WW treatment benefits from the advantages of source separation, which makes available simple small-scale systems and on-site reuse, which can be constructed on a short time schedule and occasionally upgraded with new technological developments. In this study we perform a Life Cycle Assessment to compare between the environmental impacts of four alternatives for a hypothetical city's water-wastewater service system. The baseline alternative is the most common, centralized approach for WW treatment, in which WW is conveyed to and treated in a large wastewater treatment plant (WWTP) and is then discharged to a stream. The three alternatives represent different scales of distribution of the WW treatment phase, along with urban irrigation and domestic non-potable water reuse (toilet flushing). The first alternative includes centralized treatment at a WWTP, with part of the reclaimed WW (RWW) supplied back to the urban consumers. The second and third alternatives implement de-centralized greywater (GW) treatment with local reuse, one at cluster level (320 households) and one at building level (40 households). Life cycle impact assessment results show a consistent disadvantage of the prevailing centralized approach under local conditions in Israel, where seawater desalination is the marginal source of water supply. The alternative of source separation and GW reuse at cluster level seems to be the most preferable one, though its environmental performance is only slightly better than GW reuse at building level. Centralized WW treatment with urban reuse of WWTP effluents is not advantageous over decentralized treatment of GW because the supply of RWW back to consumers is very costly in materials and energy. Electricity is a major driver of the impacts in most categories, pertaining mostly to potable water production and supply. Infrastructure was found to have a notable effect on metal depletion, human toxicity and freshwater and marine ecotoxicity. Sensitivity to major model parameters was analyzed. A shift to a larger share of renewable energy sources in the electricity mix results in a dramatic improvement in most impact categories. Switching to a mix of water sources, rather than the marginal source, leads to a significant reduction in most impacts. It is concluded that under the conditions tested, a decentralized approach to urban wastewater management is environmentally preferable to the common centralized system. It is worth exploring such options under different conditions as well, in cases which new urban infrastructure is planned or replacement of old infrastructure is required.",
keywords = "Decentralization, Greywater, Life cycle assessment, Resource management, Urban water cycle, Wastewater reuse",
author = "Tamar Opher and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2016 Elsevier Ltd",
year = "2016",
month = nov,
day = "1",
doi = "10.1016/j.jenvman.2016.07.080",
language = "אנגלית",
volume = "182",
pages = "464--476",
journal = "Journal of Environmental Management",
issn = "0301-4797",
publisher = "Academic Press Inc.",

}

Reducing inventory data requirements for scenario representation in comparative life cycle assessment (LCA), demonstrated on the urban wastewater system

Opher T, Friedler E. Reducing inventory data requirements for scenario representation in comparative life cycle assessment (LCA), demonstrated on the urban wastewater system. Urban Water Journal. 2016 Oct 2;13(7):759-772. https://doi.org/10.1080/1573062X.2015.1036084
 

Wastewater reuse has become an attractive option for alleviating the stress from water resources. Centralized wastewater reuse is a common and continuously expanding practice worldwide, but the advantages of centralized over decentralized approaches are lately being questioned. Life cycle assessment (LCA) is a well-accepted means of assessing the overall environmental performance of service systems, however, construction of a life cycle inventory (LCI) for complex systems such as urban wastewater systems, is very time consuming. Lack of resources and unavailability of data often enforce constraints on the scope of the assessment. In such cases it may be beneficial to consider the approach presented here, which manifests the differences between the studied alternatives. By eliminating processes that remain unchanged, less data and human resources are required in building the inventory, and less parameter uncertainty is introduced into the analysis. The proposed approach is demonstrated through the conceptual modeling steps of an assessment of decentralized urban wastewater reuse alternatives.

@article{c321a878cb1a4f05953f1ac6353ddd55,
title = "Reducing inventory data requirements for scenario representation in comparative life cycle assessment (LCA), demonstrated on the urban wastewater system",
abstract = "Wastewater reuse has become an attractive option for alleviating the stress from water resources. Centralized wastewater reuse is a common and continuously expanding practice worldwide, but the advantages of centralized over decentralized approaches are lately being questioned. Life cycle assessment (LCA) is a well-accepted means of assessing the overall environmental performance of service systems, however, construction of a life cycle inventory (LCI) for complex systems such as urban wastewater systems, is very time consuming. Lack of resources and unavailability of data often enforce constraints on the scope of the assessment. In such cases it may be beneficial to consider the approach presented here, which manifests the differences between the studied alternatives. By eliminating processes that remain unchanged, less data and human resources are required in building the inventory, and less parameter uncertainty is introduced into the analysis. The proposed approach is demonstrated through the conceptual modeling steps of an assessment of decentralized urban wastewater reuse alternatives.",
keywords = "distribution, greywater, life cycle assessment, uncertainty, urban water cycle, wastewater reuse, water resource management",
author = "Tamar Opher and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2015 Taylor & Francis.",
year = "2016",
month = oct,
day = "2",
doi = "10.1080/1573062X.2015.1036084",
language = "אנגלית",
volume = "13",
pages = "759--772",
journal = "Urban Water Journal",
issn = "1573-062X",
publisher = "Taylor and Francis Ltd.",
number = "7",

}

Liquid-Desiccant Vapor Separation Reduces the Energy Requirements of Atmospheric Moisture Harvesting

Gido B, Friedler E, Broday DM. Liquid-Desiccant Vapor Separation Reduces the Energy Requirements of Atmospheric Moisture Harvesting. Environmental Science and Technology. 2016 Aug 2;50(15):8362-8367. https://doi.org/10.1021/acs.est.6b01280
 

An innovative atmospheric moisture harvesting system is proposed, where water vapor is separated from the air prior to cooling and condensation. The system was studied using a model that simulates its three interconnected cycles (air, desiccant, and water) over a range of ambient conditions, and optimal configurations are reported for different operation conditions. Model results were compared to specifications of commercial atmospheric moisture harvesting systems and found to represent saving of 5-65% of the electrical energy requirements due to the vapor separation process. We show that the liquid desiccant separation stage that is integrated into atmospheric moisture harvesting systems can work under a wide range of environmental conditions using low grade or solar heating as a supplementary energy source, and that the performance of the combined system is superior.

@article{fd5e06fb2ccb47b18e605db509f14111,
title = "Liquid-Desiccant Vapor Separation Reduces the Energy Requirements of Atmospheric Moisture Harvesting",
abstract = "An innovative atmospheric moisture harvesting system is proposed, where water vapor is separated from the air prior to cooling and condensation. The system was studied using a model that simulates its three interconnected cycles (air, desiccant, and water) over a range of ambient conditions, and optimal configurations are reported for different operation conditions. Model results were compared to specifications of commercial atmospheric moisture harvesting systems and found to represent saving of 5-65% of the electrical energy requirements due to the vapor separation process. We show that the liquid desiccant separation stage that is integrated into atmospheric moisture harvesting systems can work under a wide range of environmental conditions using low grade or solar heating as a supplementary energy source, and that the performance of the combined system is superior.",
author = "Ben Gido and Eran Friedler and Broday, {David M.}",
note = "Publisher Copyright: {\textcopyright} 2016 American Chemical Society.",
year = "2016",
month = aug,
day = "2",
doi = "10.1021/acs.est.6b01280",
language = "אנגלית",
volume = "50",
pages = "8362--8367",
journal = "Environmental Science and Technology",
issn = "0013-936X",
publisher = "American Chemical Society",
number = "15",

}

Characterization of Biofilm Bacterial Communities in a Vertical Unsaturated-Flow Bioreactor Treating Domestic Greywater

Rodríguez-Martínez S, Dekel A, Aizenberg-Gershtein Y, Gilboa Y, Sharaby Y, Halpern M et al. Characterization of Biofilm Bacterial Communities in a Vertical Unsaturated-Flow Bioreactor Treating Domestic Greywater. Environmental Processes. 2016 Jun 1;3(2):325-340. https://doi.org/10.1007/s40710-016-0162-2
 

Greywater (GW) is wastewater generated from domestic activities without the input of toilet and kitchen. Its reuse can help to reduce the overall potable water consumption in urban areas. In the current study, an extensive greywater treatment unit consisting of an attached growth unsaturated-flow bio-reactor, with “BIOROCK”® medium, was developed. Its performance was studied and the bacterial communities of the BIOROCK® biofilm were characterized through 454-pyrosequencing of 16S rRNA genes. The medium physical properties (porosity and high specific surface) made it possible to support highly diverse and relatively long-term stable bacterial communities that showed spatial variations in their relative abundance. The bacterial communities were dominated by genera previously associated with wastewater environments and that present some kind of degrading activities. Consequently, after treatment, water turbidity was reduced by 83 % and COD removal efficiency was 80 %, demonstrating that most of the biodegradable matter had been removed. Some pathogens were detected, but usually at low abundances. With some minor adjustments and the addition of a chlorination step, the treated greywater generated by this system can be used for non-potable purposes, such as irrigation and toilet flushing.

@article{362dd16ab6254f4489417d64d17f6600,
title = "Characterization of Biofilm Bacterial Communities in a Vertical Unsaturated-Flow Bioreactor Treating Domestic Greywater",
abstract = "Greywater (GW) is wastewater generated from domestic activities without the input of toilet and kitchen. Its reuse can help to reduce the overall potable water consumption in urban areas. In the current study, an extensive greywater treatment unit consisting of an attached growth unsaturated-flow bio-reactor, with “BIOROCK”{\textregistered} medium, was developed. Its performance was studied and the bacterial communities of the BIOROCK{\textregistered} biofilm were characterized through 454-pyrosequencing of 16S rRNA genes. The medium physical properties (porosity and high specific surface) made it possible to support highly diverse and relatively long-term stable bacterial communities that showed spatial variations in their relative abundance. The bacterial communities were dominated by genera previously associated with wastewater environments and that present some kind of degrading activities. Consequently, after treatment, water turbidity was reduced by 83 % and COD removal efficiency was 80 %, demonstrating that most of the biodegradable matter had been removed. Some pathogens were detected, but usually at low abundances. With some minor adjustments and the addition of a chlorination step, the treated greywater generated by this system can be used for non-potable purposes, such as irrigation and toilet flushing.",
keywords = "Bacterial communities, Biofilm, Greywater, Unsaturated-flow bioreactor",
author = "Sara Rodr{\'i}guez-Mart{\'i}nez and Anat Dekel and Yana Aizenberg-Gershtein and Yael Gilboa and Yehonatan Sharaby and Malka Halpern and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2016, Springer International Publishing Switzerland.",
year = "2016",
month = jun,
day = "1",
doi = "10.1007/s40710-016-0162-2",
language = "אנגלית",
volume = "3",
pages = "325--340",
journal = "Environmental Processes",
issn = "2198-7491",
publisher = "Springer Science + Business Media",
number = "2",

}

2015

Epidemiological study for the assessment of health risks associated with graywater reuse for irrigation in arid regions

Busgang A, Friedler E, Ovadia O, Gross A. Epidemiological study for the assessment of health risks associated with graywater reuse for irrigation in arid regions. Science of the Total Environment. 2015 Dec 5;538:230-239. https://doi.org/10.1016/j.scitotenv.2015.08.009
 

Graywater reuse is rapidly gaining popularity as a viable source of reclaimed water, mainly for garden irrigation and toilet flushing. The purpose of this study was to determine, by epidemiological survey, the risk for gastroenteritis symptoms associated with graywater reuse. The study comprised a weekly health questionnaire answered by both graywater users and non-graywater users (control group) regarding their health status over a period of 1year, and periodic sampling for graywater quality. Participants were also asked to respond to a one-time lifestyle questionnaire to assess their level of exposure to graywater or potable water used in garden irrigation. Graywater quality was typical and comparable to previous studies, with average fecal coliform concentration of 103CFU 100ml-1. A Cox Proportional Hazards model indicated a somewhat higher health risk for the control group (P<0.05), suggesting that there was practically no difference in the prevalence of water-related diseases between users of graywater and potable water. Since the concentration of pathogens in the current study was higher than that suggested by quantitative microbial risk assessment (QMRA), yet there was no difference in the prevalence of water-related diseases between control and graywater users, it was postulated that QMRA is conservative and can safely be used toward the establishment of regulations governing graywater reuse.

@article{9636ca958f5f4fada5399317b6097c75,
title = "Epidemiological study for the assessment of health risks associated with graywater reuse for irrigation in arid regions",
abstract = "Graywater reuse is rapidly gaining popularity as a viable source of reclaimed water, mainly for garden irrigation and toilet flushing. The purpose of this study was to determine, by epidemiological survey, the risk for gastroenteritis symptoms associated with graywater reuse. The study comprised a weekly health questionnaire answered by both graywater users and non-graywater users (control group) regarding their health status over a period of 1year, and periodic sampling for graywater quality. Participants were also asked to respond to a one-time lifestyle questionnaire to assess their level of exposure to graywater or potable water used in garden irrigation. Graywater quality was typical and comparable to previous studies, with average fecal coliform concentration of 103CFU 100ml-1. A Cox Proportional Hazards model indicated a somewhat higher health risk for the control group (P<0.05), suggesting that there was practically no difference in the prevalence of water-related diseases between users of graywater and potable water. Since the concentration of pathogens in the current study was higher than that suggested by quantitative microbial risk assessment (QMRA), yet there was no difference in the prevalence of water-related diseases between control and graywater users, it was postulated that QMRA is conservative and can safely be used toward the establishment of regulations governing graywater reuse.",
keywords = "Epidemiology, Gastroenteritis, Graywater, Risk analysis",
author = "Allison Busgang and Eran Friedler and Ofer Ovadia and Amit Gross",
note = "Publisher Copyright: {\textcopyright} 2015 Elsevier B.V.",
year = "2015",
month = dec,
day = "5",
doi = "10.1016/j.scitotenv.2015.08.009",
language = "אנגלית",
volume = "538",
pages = "230--239",
journal = "Science of the Total Environment",
issn = "0048-9697",
publisher = "Elsevier",

}

Effect of land-use change scenarios on nutrients and TSS loads

Gilboa Y, Gal G, Markel D, Rimmer A, Evans BM, Friedler E. Effect of land-use change scenarios on nutrients and TSS loads. Environmental Processes. 2015 Dec 1;2(4):593-607. https://doi.org/10.1007/s40710-015-0109-z
 

The projected growth in population in Israel by 50 % by 2030 will greatly enhance urban density and motivate increased urbanization of rural regions in the country. The Lake Kinneret watershed is a rural region of which only about 3 % of the total area is used for residence, and currently, it is the least populated region in Israel. A significant land-use change and growth of urbanized regions is therefore expected in the near future, leading to changes in water quality management in the watershed. In this study, we attempted to quantify the effects of these possible changes in land-use on the flow and pollutant loads discharged from the watershed into Lake Kinneret. To that end, we calibrated and verified the AVGWLF (ArcView (GIS) Generalized Watershed Loading Function) model to simulate stream flows, sediment and nutrient loads under the conditions of a Mediterranean climate watershed. In addition to AVGWLF model, we used two external tools, namely: the HYdrological Model for Karst Environment (HYMKE) to predict daily flows of streams which were not simulated by the AVGWLF model, and a Mediterranean Multiplication Factor (MMF) which was used to improve sediment transport and nutrient load simulations. The combined suite of tools successfully simulated the observed data (r2 > 0.70 and Nash-Sutcliffe efficiency >0.69 for flowrate, sediment and nutrient), including extreme values. The successful combination of the models provides watershed and lake managers the ability to examine the potential land-use changes and their impact on the watershed and the lake downstream.

@article{6f0c3cdb02424a2ba3924246fb9dfd07,
title = "Effect of land-use change scenarios on nutrients and TSS loads",
abstract = "The projected growth in population in Israel by 50 % by 2030 will greatly enhance urban density and motivate increased urbanization of rural regions in the country. The Lake Kinneret watershed is a rural region of which only about 3 % of the total area is used for residence, and currently, it is the least populated region in Israel. A significant land-use change and growth of urbanized regions is therefore expected in the near future, leading to changes in water quality management in the watershed. In this study, we attempted to quantify the effects of these possible changes in land-use on the flow and pollutant loads discharged from the watershed into Lake Kinneret. To that end, we calibrated and verified the AVGWLF (ArcView (GIS) Generalized Watershed Loading Function) model to simulate stream flows, sediment and nutrient loads under the conditions of a Mediterranean climate watershed. In addition to AVGWLF model, we used two external tools, namely: the HYdrological Model for Karst Environment (HYMKE) to predict daily flows of streams which were not simulated by the AVGWLF model, and a Mediterranean Multiplication Factor (MMF) which was used to improve sediment transport and nutrient load simulations. The combined suite of tools successfully simulated the observed data (r2 > 0.70 and Nash-Sutcliffe efficiency >0.69 for flowrate, sediment and nutrient), including extreme values. The successful combination of the models provides watershed and lake managers the ability to examine the potential land-use changes and their impact on the watershed and the lake downstream.",
keywords = "AVGWLF, HYMKE, Lake Kinneret watershed, Sediment and nutrient loads, Watershed model",
author = "Yael Gilboa and Gideon Gal and Doron Markel and Alon Rimmer and Evans, {Barry M.} and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2015 Springer International Publishing Switzerland.",
year = "2015",
month = dec,
day = "1",
doi = "10.1007/s40710-015-0109-z",
language = "אנגלית",
volume = "2",
pages = "593--607",
journal = "Environmental Processes",
issn = "2198-7491",
publisher = "Springer Science + Business Media",
number = "4",

}

Legionella pneumophila: From potable water to treated greywater; quantification and removal during treatment

Blanky M, Rodríguez-Martínez S, Halpern M, Friedler E. Legionella pneumophila: From potable water to treated greywater; quantification and removal during treatment. Science of the Total Environment. 2015 Nov 5;533:557-565. https://doi.org/10.1016/j.scitotenv.2015.06.121
 

Greywater is an alternative water source that can help alleviate stress on depleted water resources. The main options for greywater reuse are toilet flushing and garden irrigation, both producing aerosols. For that reason transmission of inhalable pathogens like Legionella present a potential risk. To improve the understanding about Legionella in greywater, we traced the pathogen seasonally from the potable water system to the final steps of the greywater treatment in four houses in northern Israel. Physicochemical and microbiological parameters were analyzed in order to assess background greywater quality and to establish possible associations with Legionella. The mean concentrations of Legionella pneumophila isolated from the potable water system were 6.4×102 and 5.9×103cfu/l in cold and hot water respectively. By amending the ISO protocol for Legionella isolation from drinking water, we succeeded in quantifying Legionella in greywater. The mean Legionella concentrations that were found in raw, treated and treated chlorinated greywater were 1.2×105, 2.4×104 and 5.7×103cfu/l respectively. While Legionella counts in potable water presented a seasonal pattern with high concentrations in summer, its counts in greywater presented an almost inversed pattern. Greywater treatment resulted in 95% decrease in Legionella counts. No significant difference was found between Legionella concentrations in potable water and the treated chlorinated greywater. These findings indicate that regarding Legionella, reusing treated chlorinated greywater would exhibit a risk that is very similar to the risk associated with using potable water for the same non-potable uses.

@article{e2b4b52029544162becf23681aad800a,
title = "Legionella pneumophila: From potable water to treated greywater; quantification and removal during treatment",
abstract = "Greywater is an alternative water source that can help alleviate stress on depleted water resources. The main options for greywater reuse are toilet flushing and garden irrigation, both producing aerosols. For that reason transmission of inhalable pathogens like Legionella present a potential risk. To improve the understanding about Legionella in greywater, we traced the pathogen seasonally from the potable water system to the final steps of the greywater treatment in four houses in northern Israel. Physicochemical and microbiological parameters were analyzed in order to assess background greywater quality and to establish possible associations with Legionella. The mean concentrations of Legionella pneumophila isolated from the potable water system were 6.4×102 and 5.9×103cfu/l in cold and hot water respectively. By amending the ISO protocol for Legionella isolation from drinking water, we succeeded in quantifying Legionella in greywater. The mean Legionella concentrations that were found in raw, treated and treated chlorinated greywater were 1.2×105, 2.4×104 and 5.7×103cfu/l respectively. While Legionella counts in potable water presented a seasonal pattern with high concentrations in summer, its counts in greywater presented an almost inversed pattern. Greywater treatment resulted in 95% decrease in Legionella counts. No significant difference was found between Legionella concentrations in potable water and the treated chlorinated greywater. These findings indicate that regarding Legionella, reusing treated chlorinated greywater would exhibit a risk that is very similar to the risk associated with using potable water for the same non-potable uses.",
keywords = "Chlorination, Greywater, Legionella, Removal efficiency, TOC, Treatment",
author = "Marina Blanky and Sara Rodr{\'i}guez-Mart{\'i}nez and Malka Halpern and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2015 Elsevier B.V.",
year = "2015",
month = nov,
day = "5",
doi = "10.1016/j.scitotenv.2015.06.121",
language = "אנגלית",
volume = "533",
pages = "557--565",
journal = "Science of the Total Environment",
issn = "0048-9697",
publisher = "Elsevier",

}

A critical review of methods used to obtain flow patterns and volumes of individual domestic water using appliances

Morrison J, Friedler E. A critical review of methods used to obtain flow patterns and volumes of individual domestic water using appliances. Urban Water Journal. 2015 May 19;12(4):328-343. https://doi.org/10.1080/1573062X.2014.900090
 

Determining the daily flow rates and water use patterns of specific household fixtures and appliances is important for water use monitoring, deriving effective strategies for water demand management, designing onsite water reuse systems, and efficient planning and investment in the urban water sector. Currently, there are a limited number of publications which address the need to measure flow patterns and volumes of individual household water-using appliances, or which analyze the alternatives to do so. This paper critically reviews and compares different methods of obtaining the specific flow patterns and volumes of water used by individual household water-using microcomponents (i.e. toilet, bath/shower, washbasin, washing machine, kitchen sink, dishwasher, etc.) in order to make recommendations about the appropriateness of these methodologies for various applications.

@article{f3681dccc8f3489ea71d97b531bda5c9,
title = "A critical review of methods used to obtain flow patterns and volumes of individual domestic water using appliances",
abstract = "Determining the daily flow rates and water use patterns of specific household fixtures and appliances is important for water use monitoring, deriving effective strategies for water demand management, designing onsite water reuse systems, and efficient planning and investment in the urban water sector. Currently, there are a limited number of publications which address the need to measure flow patterns and volumes of individual household water-using appliances, or which analyze the alternatives to do so. This paper critically reviews and compares different methods of obtaining the specific flow patterns and volumes of water used by individual household water-using microcomponents (i.e. toilet, bath/shower, washbasin, washing machine, kitchen sink, dishwasher, etc.) in order to make recommendations about the appropriateness of these methodologies for various applications.",
keywords = "appliance water use, diurnal flow pattern, domestic water demand, flow pattern analysis, microcomponent water demand, water consumption and prediction",
author = "Jane Morrison and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2014, {\textcopyright} 2014 Taylor & Francis.",
year = "2015",
month = may,
day = "19",
doi = "10.1080/1573062X.2014.900090",
language = "אנגלית",
volume = "12",
pages = "328--343",
journal = "Urban Water Journal",
issn = "1573-062X",
publisher = "Taylor and Francis Ltd.",
number = "4",

}

A continuous active monitoring approach to identify cross-connections between potable water and effluent distribution systems

Friedler E, Alfiya Y, Shaviv A, Gilboa Y, Harussi Y, Raize O. A continuous active monitoring approach to identify cross-connections between potable water and effluent distribution systems. Environmental Monitoring and Assessment. 2015 Mar;187(3):131. https://doi.org/10.1007/s10661-015-4350-8
 

A continuous active monitoring approach was developed for identification of cross-connections between potable water supply systems and treated wastewater effluent reuse distribution systems. The approach is based on monitoring the oxidation reduction potential (ORP) at the potable water system while injecting sulfite (a reducing agent) into the effluent line. A sharp decrease in the ORP of the potable water would indicate a cross-connection event. The approach was tested in batch experiments on treated municipal wastewater effluent of varying degree of treatment, and at dilution ratios of up to 1:100 (effluent/potable). The approach was then examined under continuous flow conditions, which simulated cross-connection events at various dilution ratios (up to 1:100). In the continuous runs, differences between the potable water ORP and the effluent–potable water mixture (containing sulfite as sodium bisulfite (SBS)) ORP were 450–630 mV. This suggests high potential for identifying a cross-connection event. Implementation of the approach includes adding sulfite to effluent used for agricultural irrigation; hence, possible effects on soil and on crops were studied in soil columns and pots planted with basil (Ocimum basilicum) as a model plant. No negative effects of sulfite addition to the irrigation effluent were observed in the irrigated soils and plants, and therefore, it could be safely implemented also in agricultural applications.

@article{af6940e6b73148b2a4dc429252d08cc2,
title = "A continuous active monitoring approach to identify cross-connections between potable water and effluent distribution systems",
abstract = "A continuous active monitoring approach was developed for identification of cross-connections between potable water supply systems and treated wastewater effluent reuse distribution systems. The approach is based on monitoring the oxidation reduction potential (ORP) at the potable water system while injecting sulfite (a reducing agent) into the effluent line. A sharp decrease in the ORP of the potable water would indicate a cross-connection event. The approach was tested in batch experiments on treated municipal wastewater effluent of varying degree of treatment, and at dilution ratios of up to 1:100 (effluent/potable). The approach was then examined under continuous flow conditions, which simulated cross-connection events at various dilution ratios (up to 1:100). In the continuous runs, differences between the potable water ORP and the effluent–potable water mixture (containing sulfite as sodium bisulfite (SBS)) ORP were 450–630 mV. This suggests high potential for identifying a cross-connection event. Implementation of the approach includes adding sulfite to effluent used for agricultural irrigation; hence, possible effects on soil and on crops were studied in soil columns and pots planted with basil (Ocimum basilicum) as a model plant. No negative effects of sulfite addition to the irrigation effluent were observed in the irrigated soils and plants, and therefore, it could be safely implemented also in agricultural applications.",
keywords = "Basil, Cross-connection detection, Dual distribution systems, ORP, Online monitoring, Plants; s, Public health, Soil, Sulfite, Wastewater reuse",
author = "E. Friedler and Y. Alfiya and A. Shaviv and Y. Gilboa and Y. Harussi and O. Raize",
note = "Publisher Copyright: {\textcopyright} 2015, Springer International Publishing Switzerland.",
year = "2015",
month = mar,
doi = "10.1007/s10661-015-4350-8",
language = "אנגלית",
volume = "187",
journal = "Environmental Monitoring and Assessment",
issn = "0167-6369",
publisher = "Springer Netherlands",
number = "3",

}

Greywater reuse

Gross A, Maimon A, Alfiya Y, Friedler E. Greywater reuse. 2015. 301 p.
@book{ce34d494167f4314be00eeb18dd2e1c7,
title = "Greywater reuse",
keywords = "greywater, greywater reuse, Greywater treatment, Decentralised reuse, onsite reuse, Onsite wastewater treatment",
author = "Amit Gross and Adi Maimon and Yuval Alfiya and Eran Friedler",
year = "2015",
language = "American English",
isbn = "9781482255041",

}

Greywater reuse: risk identification, quantification and management

Friedler E, Gross A. Greywater reuse: risk identification, quantification and management. In Memon F, Ward S, editors, Alternative Water Supply Systems. IWA Publishing. 2015. p. 193 https://doi.org/https://doi.org/10.2166/9781780405513
@inbook{83f53a64c42f4640b4444550c565c320,
title = "Greywater reuse: risk identification, quantification and management",
author = "Eran Friedler and Amit Gross",
year = "2015",
doi = "https://doi.org/10.2166/9781780405513",
language = "American English",
isbn = "9781780405506",
pages = "193",
editor = "F Memon and S Ward",
booktitle = "Alternative Water Supply Systems",
publisher = "IWA Publishing",
address = "United Kingdom",

}

Legionella spp. isolation and quantification from greywater

Rodríguez-Martínez S, Blanky M, Friedler E, Halpern M. Legionella spp. isolation and quantification from greywater. MethodsX. 2015;2:458-462. https://doi.org/10.1016/j.mex.2015.11.004
 

Legionella, an opportunistic human pathogen whose natural environment is water, is transmitted to humans through inhalation of contaminated aerosols. Legionella has been isolated from a high diversity of water types. Due its importance as a pathogen, two ISO protocols have been developed for its monitoring. However, these two protocols are not suitable for analyzing Legionella in greywater (GW). GW is domestic wastewater excluding the inputs from toilets and kitchen. It can serve as an alternative water source, mainly for toilet flushing and garden irrigation; both producing aerosols that can cause a risk for Legionella infection. Hence, before reuse, GW has to be treated and its quality needs to be monitored. The difficulty of Legionella isolation from GW strives in the very high load of contaminant bacteria. Here we describe a modification of the ISO protocol 11731:1998 that enables the isolation and quantification of Legionella from GW samples. The following modifications were made:To enable isolation of Legionella from greywater, a pre-filtration step that removes coarse matter is recommended.Legionella can be isolated after a combined acid-thermic treatment that eliminates the high load of contaminant bacteria in the sample.

@article{d9be1bd123fd4a0f8db12cc00e0d4ef6,
title = "Legionella spp. isolation and quantification from greywater",
abstract = "Legionella, an opportunistic human pathogen whose natural environment is water, is transmitted to humans through inhalation of contaminated aerosols. Legionella has been isolated from a high diversity of water types. Due its importance as a pathogen, two ISO protocols have been developed for its monitoring. However, these two protocols are not suitable for analyzing Legionella in greywater (GW). GW is domestic wastewater excluding the inputs from toilets and kitchen. It can serve as an alternative water source, mainly for toilet flushing and garden irrigation; both producing aerosols that can cause a risk for Legionella infection. Hence, before reuse, GW has to be treated and its quality needs to be monitored. The difficulty of Legionella isolation from GW strives in the very high load of contaminant bacteria. Here we describe a modification of the ISO protocol 11731:1998 that enables the isolation and quantification of Legionella from GW samples. The following modifications were made:To enable isolation of Legionella from greywater, a pre-filtration step that removes coarse matter is recommended.Legionella can be isolated after a combined acid-thermic treatment that eliminates the high load of contaminant bacteria in the sample.",
keywords = "Acid-thermictreatment, Culture, Greywater, ISO11731:1998, Legionella isolation, Pre-filtration",
author = "Sara Rodr{\'i}guez-Mart{\'i}nez and Marina Blanky and Eran Friedler and Malka Halpern",
note = "Publisher Copyright: {\textcopyright} 2015 The Authors. Published by Elsevier B.V.",
year = "2015",
doi = "10.1016/j.mex.2015.11.004",
language = "אנגלית",
volume = "2",
pages = "458--462",
journal = "MethodsX",
issn = "2215-0161",
publisher = "Elsevier BV",

}

2014

Defining limits to multiple and simultaneous anthropogenic stressors in a lake ecosystem - Lake Kinneret as a case study

Gilboa Y, Gal G, Friedler E. Defining limits to multiple and simultaneous anthropogenic stressors in a lake ecosystem - Lake Kinneret as a case study. Environmental Modelling and Software. 2014 Nov 1;61:424-432. https://doi.org/10.1016/j.envsoft.2014.05.014
 

In this study we expanded a recently developed approach for defining acceptable levels of management policy that will allow sustainable management of water quality in a lake ecosystem. A three dimensional solution space was created to define all acceptable scenarios of N loads, P loads and lake water level (WL) thus providing an integrated tool for defining the extent of measures that will allow lake ecosystem sustainability. The approach included use of a lake ecosystem model, a quantitative system of composite water quality indices (CWQIs) and defined sustainability criteria for the ecosystem. The approach was tested on the Lake Kinneret (Sea of Galilee) ecosystem and succeeded in defining the range of acceptable management policy through the use of long term simulations of different scenarios. Using the results of the scenarios, a number of polygons were created, defined as relative solution domain area (RSDA), which denote the permissible ranges of nutrient loads at different water levels. The polygon, and hence RSDA, boundaries represent critical values of nutrient loads allowing conservation of the lake water quality at each WL. By integrating all RSDA, a three dimensional solution space was created which defines all acceptable ranges of N loads, P loads and WL thus providing lake managers with an integrated tool for defining the extent of measures that will allow sustainability of the lake ecosystem. This novel approach is unique, and presents an example of implementation of a management tool that integrates an ecosystem model, multiple stressors and quantified water quality indices to determine limits of management actions. This approach may well be implemented to other lakes around the world suffering from water quality deterioration as a result of changes in water level and nutrients loads.

@article{b17e8f83dc9748cf98cb2656f7944f6a,
title = "Defining limits to multiple and simultaneous anthropogenic stressors in a lake ecosystem - Lake Kinneret as a case study",
abstract = "In this study we expanded a recently developed approach for defining acceptable levels of management policy that will allow sustainable management of water quality in a lake ecosystem. A three dimensional solution space was created to define all acceptable scenarios of N loads, P loads and lake water level (WL) thus providing an integrated tool for defining the extent of measures that will allow lake ecosystem sustainability. The approach included use of a lake ecosystem model, a quantitative system of composite water quality indices (CWQIs) and defined sustainability criteria for the ecosystem. The approach was tested on the Lake Kinneret (Sea of Galilee) ecosystem and succeeded in defining the range of acceptable management policy through the use of long term simulations of different scenarios. Using the results of the scenarios, a number of polygons were created, defined as relative solution domain area (RSDA), which denote the permissible ranges of nutrient loads at different water levels. The polygon, and hence RSDA, boundaries represent critical values of nutrient loads allowing conservation of the lake water quality at each WL. By integrating all RSDA, a three dimensional solution space was created which defines all acceptable ranges of N loads, P loads and WL thus providing lake managers with an integrated tool for defining the extent of measures that will allow sustainability of the lake ecosystem. This novel approach is unique, and presents an example of implementation of a management tool that integrates an ecosystem model, multiple stressors and quantified water quality indices to determine limits of management actions. This approach may well be implemented to other lakes around the world suffering from water quality deterioration as a result of changes in water level and nutrients loads.",
keywords = "CWQI, Ecosystem model, Lake ecosystem sustainability, Lake management, Nutrient loads, RSDA, Scenarios, WFD, WL, WQ, WQI",
author = "Yael Gilboa and Gideon Gal and Eran Friedler",
note = "Publisher Copyright: {\textcopyright} 2014 Elsevier Ltd.",
year = "2014",
month = nov,
day = "1",
doi = "10.1016/j.envsoft.2014.05.014",
language = "אנגלית",
volume = "61",
pages = "424--432",
journal = "Environmental Modelling and Software",
issn = "1364-8152",
publisher = "Elsevier BV",

}

Parameters affecting greywater quality and its safety for reuse

Maimon A, Friedler E, Gross A. Parameters affecting greywater quality and its safety for reuse. Science of the Total Environment. 2014 Jul 15;487(1):20-25. https://doi.org/10.1016/j.scitotenv.2014.03.133
 

Reusing greywater (GW) for on-site irrigation is becoming a common practice worldwide. Alongside its benefits, GW reuse might pose health and environmental risks. The current study assesses the risks associated with on-site GW reuse and the main factors affecting them. GW from 34 households in Israel was analyzed for physicochemical parameters, Escherichia coli (as an indicator for rotavirus), Pseudomonas aeruginosa and Staphylococcus aureus. Each participating household filled out a questionnaire about their GW sources, treatment and usages. Quantitative microbial risk assessment (QMRA) was performed based on the measured microbial quality, and on exposure scenarios derived from the questionnaires and literature data. The type of treatment was found to have a significant effect on the quality of the treated GW. The average E. coli counts in GW (which exclude kitchen effluent) treated by professionally-designed system resulted in acceptable risk under all exposure scenarios while the risk from inadequately-treated GW was above the accepted level as set by the WHO. In conclusion, safe GW reuse requires a suitable and well-designed treatment system.

@article{fb116c55371b4a999a0cee4c511ae0e6,
title = "Parameters affecting greywater quality and its safety for reuse",
abstract = "Reusing greywater (GW) for on-site irrigation is becoming a common practice worldwide. Alongside its benefits, GW reuse might pose health and environmental risks. The current study assesses the risks associated with on-site GW reuse and the main factors affecting them. GW from 34 households in Israel was analyzed for physicochemical parameters, Escherichia coli (as an indicator for rotavirus), Pseudomonas aeruginosa and Staphylococcus aureus. Each participating household filled out a questionnaire about their GW sources, treatment and usages. Quantitative microbial risk assessment (QMRA) was performed based on the measured microbial quality, and on exposure scenarios derived from the questionnaires and literature data. The type of treatment was found to have a significant effect on the quality of the treated GW. The average E. coli counts in GW (which exclude kitchen effluent) treated by professionally-designed system resulted in acceptable risk under all exposure scenarios while the risk from inadequately-treated GW was above the accepted level as set by the WHO. In conclusion, safe GW reuse requires a suitable and well-designed treatment system.",
keywords = "Garden irrigation, Greywater, Microbial quality, Onsite reuse, QMRA, Risk assessment",
author = "Adi Maimon and Eran Friedler and Amit Gross",
note = "Funding Information: This research was partially funded by the Tzuk Maccabi Fund and Israel Water Authority . ",
year = "2014",
month = jul,
day = "15",
doi = "10.1016/j.scitotenv.2014.03.133",
language = "אנגלית",
volume = "487",
pages = "20--25",
journal = "Science of the Total Environment",
issn = "0048-9697",
publisher = "Elsevier",
number = "1",

}

Greywater use in Israel and worldwide: Standards and prospects

Oron G, Adel M, Agmon V, Friedler E, Halperin R, Leshem E et al. Greywater use in Israel and worldwide: Standards and prospects. Water Research. 2014 Jul 1;58:92-101. https://doi.org/10.1016/j.watres.2014.03.032
 

Water shortage around the world enhanced the search for alternative sources. Greywater (GW) can serve as a solution for water demands especially in arid and semi-arid zones. However, issues considered which include acceptability of GW segregation as a separate water treated stream, allowing its use onsite. Consequently, it is the one of next forthcoming water resources that will be used, primarily in the growing mega-cities. It will be even more rentable when combined with the roof runoff water harvesting and condensing water from air-conditioning systems. Reuse of GW is as well beneficial in the mega-cities subject to the high expenses associated with wastewater and fresh water conveyance in the opposite direction. The main problem associated with GW reuse is the quality of the water and the targeted reuse options. At least two main options can be identified: the public sector that is ready to reuse the GW and the private sector which raises extra issues related to the reuse risks. These risk stems from the on yard use of GW, relatively close to the household location. The main focus of the Israeli guidelines for GW use is on the private and single house. The problem is less rigorous in public facilities, where the amounts are relatively large and the raw GW is relatively diluted. The two main principles adopted for reuse are: (i) greywater can be minimally treated since it differs from the black wastes, and; (ii) no contact exists with the resident around. The aggravated standards are an indication of the sensitivity issues related to the problem.

@article{8b764791dc9a42e5a8241c7c10986d80,
title = "Greywater use in Israel and worldwide: Standards and prospects",
abstract = "Water shortage around the world enhanced the search for alternative sources. Greywater (GW) can serve as a solution for water demands especially in arid and semi-arid zones. However, issues considered which include acceptability of GW segregation as a separate water treated stream, allowing its use onsite. Consequently, it is the one of next forthcoming water resources that will be used, primarily in the growing mega-cities. It will be even more rentable when combined with the roof runoff water harvesting and condensing water from air-conditioning systems. Reuse of GW is as well beneficial in the mega-cities subject to the high expenses associated with wastewater and fresh water conveyance in the opposite direction. The main problem associated with GW reuse is the quality of the water and the targeted reuse options. At least two main options can be identified: the public sector that is ready to reuse the GW and the private sector which raises extra issues related to the reuse risks. These risk stems from the on yard use of GW, relatively close to the household location. The main focus of the Israeli guidelines for GW use is on the private and single house. The problem is less rigorous in public facilities, where the amounts are relatively large and the raw GW is relatively diluted. The two main principles adopted for reuse are: (i) greywater can be minimally treated since it differs from the black wastes, and; (ii) no contact exists with the resident around. The aggravated standards are an indication of the sensitivity issues related to the problem.",
keywords = "Criteria, Greywater, Private sector, Public sector, Reuse",
author = "Gideon Oron and Mike Adel and Vered Agmon and Eran Friedler and Rami Halperin and Ehud Leshem and Daniel Weinberg",
year = "2014",
month = jul,
day = "1",
doi = "10.1016/j.watres.2014.03.032",
language = "אנגלית",
volume = "58",
pages = "92--101",
journal = "Water Research",
issn = "0043-1354",
publisher = "Elsevier Ltd.",

}

Uncertainty in the river export modelling of pesticides and transformation products

Gassmann M, Khodorkovsky M, Friedler E, Dubowski Y, Olsson O. Uncertainty in the river export modelling of pesticides and transformation products. Environmental Modelling and Software. 2014 Jan;51:35-44. https://doi.org/10.1016/j.envsoft.2013.09.021
 

The modelling of agrochemical pollutants in the environment is burdened by numerous uncertainties. Not only parameter values are uncertain but often also the mass and timing of application. By introducing transformation products (TPs) into modelling, further uncertainty, coming from the dependence of these substances on their parent compounds and the introduction of new model parameters, is likely. The purpose of this study was the investigation of the behaviour of a parsimonious catchment scale model for the assessment of river concentrations of the insecticide Chlorpyrifos (CP) and its two main TPs, Chlorpyrifos Oxon (CPO) and 3,5,6-trichloro-2-pyridinol (TCP) under the influence of uncertain input parameter values. Especially parameter uncertainty and pesticide application uncertainty were investigated by Global Sensitivity Analysis (GSA) and the Generalized Likelihood Uncertainty Estimation (GLUE) method, based on Monte-Carlo sampling.GSA revealed that half-lives and sorption parameters as well as half-lives and transformation parameters were correlated to each other. This means the concepts of modelling sorption and degradation/transformation were correlated. Thus, it may be difficult in modelling studies to optimise parameter values for these modules. Furthermore, we could show that erroneous pesticide application mass and timing were compensated during Monte-Carlo sampling by changing the half-life of CP. However, the introduction of TCP into the calculation of the objective function was able to enhance the identifiability of pesticide application mass. The GLUE analysis showed that CP and TCP were modelled sufficiently, but CPO modelling failed with high uncertainty and insensitive parameters. We assumed a structural error of the model which was especially important for CPO assessment. This shows there is the possibility that a chemical and some of its TPs can be modelled successfully by a specific model structure, but for other TPs the model structure may not be suitable. Concluding, this study confirmed that the introduction of TPs into pesticide fate and export modelling from hydrological catchments amplifies parameter uncertainty and model structure uncertainty.

@article{0a47b3a08fa743ab82e15a937c94fdba,
title = "Uncertainty in the river export modelling of pesticides and transformation products",
abstract = "The modelling of agrochemical pollutants in the environment is burdened by numerous uncertainties. Not only parameter values are uncertain but often also the mass and timing of application. By introducing transformation products (TPs) into modelling, further uncertainty, coming from the dependence of these substances on their parent compounds and the introduction of new model parameters, is likely. The purpose of this study was the investigation of the behaviour of a parsimonious catchment scale model for the assessment of river concentrations of the insecticide Chlorpyrifos (CP) and its two main TPs, Chlorpyrifos Oxon (CPO) and 3,5,6-trichloro-2-pyridinol (TCP) under the influence of uncertain input parameter values. Especially parameter uncertainty and pesticide application uncertainty were investigated by Global Sensitivity Analysis (GSA) and the Generalized Likelihood Uncertainty Estimation (GLUE) method, based on Monte-Carlo sampling.GSA revealed that half-lives and sorption parameters as well as half-lives and transformation parameters were correlated to each other. This means the concepts of modelling sorption and degradation/transformation were correlated. Thus, it may be difficult in modelling studies to optimise parameter values for these modules. Furthermore, we could show that erroneous pesticide application mass and timing were compensated during Monte-Carlo sampling by changing the half-life of CP. However, the introduction of TCP into the calculation of the objective function was able to enhance the identifiability of pesticide application mass. The GLUE analysis showed that CP and TCP were modelled sufficiently, but CPO modelling failed with high uncertainty and insensitive parameters. We assumed a structural error of the model which was especially important for CPO assessment. This shows there is the possibility that a chemical and some of its TPs can be modelled successfully by a specific model structure, but for other TPs the model structure may not be suitable. Concluding, this study confirmed that the introduction of TPs into pesticide fate and export modelling from hydrological catchments amplifies parameter uncertainty and model structure uncertainty.",
keywords = "Chlorpyrifos, GLUE method, Parameter uncertainty, Pesticide, Sensitivity analysis, Transformation product",
author = "Matthias Gassmann and Miriam Khodorkovsky and Eran Friedler and Yael Dubowski and Oliver Olsson",
note = "Funding Information: This study was financed by the state of Lower Saxony, Germany , Ministry of Science and Culture and by the VW foundation . We also would like to thank Doron Markel and Dafna Amar from the Israel Water Authority (IWA) for their support and Alon Rimmer from the Kinneret Limnological Laboratory for sharing his local expertise. During the review process, precious comments were provided by the reviewers which helped to improve the document.",
year = "2014",
month = jan,
doi = "10.1016/j.envsoft.2013.09.021",
language = "אנגלית",
volume = "51",
pages = "35--44",
journal = "Environmental Modelling and Software",
issn = "1364-8152",
publisher = "Elsevier BV",

}

Academics perception towards various water reuse options: University of Trás-os-Montes e Alto-Douro - UTAD Campus (Portugal) as a case study

Matos C, Friedler E, Monteiro A, Rodrigues A, Teixeira R, Bentes I et al. Academics perception towards various water reuse options: University of Trás-os-Montes e Alto-Douro - UTAD Campus (Portugal) as a case study. Urban Water Journal. 2014;11(4):311-322. https://doi.org/10.1080/1573062X.2013.775314
 

Any strategy of water reuse has to achieve social acceptance to be successful. This paper presents the results of a multiple choice survey that attempted to establish the general attitude toward water reuse by asking academics in UTAD (Portugal) a wide range of questions. The survey included 20 reuse options, which were clustered into three reuse categories, specifically: low, medium and high contact levels. Correlation analysis between the level of support of low, medium and high contact options and demographic characteristics, personal and environmental beliefs was performed.Results show that a high proportion of the participants supported low and medium contact reuse options. Correlation was found to exist between the income classes and to the level of support of medium and high reuse options and between education level and the support for high contact reuse options.The responses to the survey suggested that some beliefs influence the level of support.

@article{0c33dae3a207428689cbfa5e53eda3f6,
title = "Academics perception towards various water reuse options: University of Tr{\'a}s-os-Montes e Alto-Douro - UTAD Campus (Portugal) as a case study",
abstract = "Any strategy of water reuse has to achieve social acceptance to be successful. This paper presents the results of a multiple choice survey that attempted to establish the general attitude toward water reuse by asking academics in UTAD (Portugal) a wide range of questions. The survey included 20 reuse options, which were clustered into three reuse categories, specifically: low, medium and high contact levels. Correlation analysis between the level of support of low, medium and high contact options and demographic characteristics, personal and environmental beliefs was performed.Results show that a high proportion of the participants supported low and medium contact reuse options. Correlation was found to exist between the income classes and to the level of support of medium and high reuse options and between education level and the support for high contact reuse options.The responses to the survey suggested that some beliefs influence the level of support.",
keywords = "academic opinion, public acceptance, water reuse",
author = "Cristina Matos and Eran Friedler and Ana Monteiro and Andr{\'e} Rodrigues and Rita Teixeira and Isabel Bentes and Jo{\~a}o Varaj{\~a}o",
year = "2014",
doi = "10.1080/1573062X.2013.775314",
language = "אנגלית",
volume = "11",
pages = "311--322",
journal = "Urban Water Journal",
issn = "1573-062X",
publisher = "Taylor and Francis Ltd.",
number = "4",

}

Assessment of the effects of greywater reuse on gross solids movement in sewer systems

Penn R, Schütze M, Friedler E. Assessment of the effects of greywater reuse on gross solids movement in sewer systems. Water Science and Technology. 2014;69(1):99-105. https://doi.org/10.2166/wst.2013.555
 

Onsite greywater reuse (GWR) and installation of water-efficient toilets (WETs) reduce urban freshwater demand and thus enhance urban water use sustainability. Research on GWR and WETs has generally overlooked their potential effects on municipal sewer systems: GWR and WETs affect the flow regime in sewers, and consequently also in fluence gross solids transport. To asses these impacts, a gross solids transport model was developed. The model is based on approaches found in the literature. Hydrodynamic calculations of sewage flow were performed using the SIMBA6 simulator and then used for the gross solid movement models. Flow characteristics in the up- and downstream sections of the sewer network differ. Therefore different approaches were used to model solids movement in each of these two parts. Each model determines whether a solid moves as a result of a momentary sewage flow, and if it moves, calculation of its velocity is possible. The paper shows the adoption and implementation of two gross solids transport models using SIMBA6 and depicts the results of the effects of various GWR and WET scenarios on gross solids movement in sewers for a real case study in Israel.

@article{560e9b541d7d480eb2893069bd454107,
title = "Assessment of the effects of greywater reuse on gross solids movement in sewer systems",
abstract = "Onsite greywater reuse (GWR) and installation of water-efficient toilets (WETs) reduce urban freshwater demand and thus enhance urban water use sustainability. Research on GWR and WETs has generally overlooked their potential effects on municipal sewer systems: GWR and WETs affect the flow regime in sewers, and consequently also in fluence gross solids transport. To asses these impacts, a gross solids transport model was developed. The model is based on approaches found in the literature. Hydrodynamic calculations of sewage flow were performed using the SIMBA6 simulator and then used for the gross solid movement models. Flow characteristics in the up- and downstream sections of the sewer network differ. Therefore different approaches were used to model solids movement in each of these two parts. Each model determines whether a solid moves as a result of a momentary sewage flow, and if it moves, calculation of its velocity is possible. The paper shows the adoption and implementation of two gross solids transport models using SIMBA6 and depicts the results of the effects of various GWR and WET scenarios on gross solids movement in sewers for a real case study in Israel.",
keywords = "Greywater reuse, Gross solids movement, Modeling, Municipal sewers, Simulation, Water-efficient toilets",
author = "R. Penn and M. Sch{\"u}tze and E. Friedler",
year = "2014",
doi = "10.2166/wst.2013.555",
language = "אנגלית",
volume = "69",
pages = "99--105",
journal = "Water Science and Technology",
issn = "0273-1223",
publisher = "IWA Publishing",
number = "1",

}

Environmental impact of irrigation with greywater treated by recirculating vertical flow constructed wetlands in two climatic regions

Gross A, Alfiya Y, Sklarz M, Maimon A, Friedler E. Environmental impact of irrigation with greywater treated by recirculating vertical flow constructed wetlands in two climatic regions. Water Science and Technology. 2014;69(12):2452-2459. https://doi.org/10.2166/wst.2014.159
 

Reuse of greywater (GW) has raised environmental and public health concerns. Specifically, these concerns relate to onsite treatment operated by non-professionals; systems must therefore be reliable, simple to use and also economically feasible if they are to be widely used. The aims of this study were to: (a) investigate GW treatment efficiency using 20 full-scale recirculating vertical flow constructed wetlands (RVFCWs) operated in households in arid and Mediterranean regions; and (b) study the long-term effects of irrigation with treated GW on soil properties. RVFCW systems were installed and monitored routinely over 3 years. Raw, treated and disinfected treated GW samples were analyzed for various physicochemical and microbial parameters. Native soil plots and nearby freshwater (FW) and treated GW irrigated soil plots were sampled twice a year - at the end of the winter and at the end of the summer. Soil samples were analyzed for various physicochemical and microbial parameters. Overall, the RVFCW proved to be a robust and reliable GW treatment system. The treated GW quality met strict Israeli regulations for urban irrigation. Results also suggest that irrigation with sufficiently treated GW has no adverse effects on soil properties. Yet, continued monitoring to follow longer term trends is recommended.

@article{ea54255bb8d5481d956b9c00f641a405,
title = "Environmental impact of irrigation with greywater treated by recirculating vertical flow constructed wetlands in two climatic regions",
abstract = "Reuse of greywater (GW) has raised environmental and public health concerns. Specifically, these concerns relate to onsite treatment operated by non-professionals; systems must therefore be reliable, simple to use and also economically feasible if they are to be widely used. The aims of this study were to: (a) investigate GW treatment efficiency using 20 full-scale recirculating vertical flow constructed wetlands (RVFCWs) operated in households in arid and Mediterranean regions; and (b) study the long-term effects of irrigation with treated GW on soil properties. RVFCW systems were installed and monitored routinely over 3 years. Raw, treated and disinfected treated GW samples were analyzed for various physicochemical and microbial parameters. Native soil plots and nearby freshwater (FW) and treated GW irrigated soil plots were sampled twice a year - at the end of the winter and at the end of the summer. Soil samples were analyzed for various physicochemical and microbial parameters. Overall, the RVFCW proved to be a robust and reliable GW treatment system. The treated GW quality met strict Israeli regulations for urban irrigation. Results also suggest that irrigation with sufficiently treated GW has no adverse effects on soil properties. Yet, continued monitoring to follow longer term trends is recommended.",
keywords = "Greywater, Reuse, Soil quality",
author = "Amit Gross and Yuval Alfiya and Menachem Sklarz and Adi Maimon and Eran Friedler",
year = "2014",
doi = "10.2166/wst.2014.159",
language = "אנגלית",
volume = "69",
pages = "2452--2459",
journal = "Water Science and Technology",
issn = "0273-1223",
publisher = "IWA Publishing",
number = "12",

}

2013

Multi-objective evolutionary optimization for greywater reuse in municipal sewer systems

Penn R, Eran F, Ostfeld A. Multi-objective evolutionary optimization for greywater reuse in municipal sewer systems. Water Research. 2013 Oct 1;47(15):5911-5920. https://doi.org/10.1016/j.watres.2013.07.012
 

Sustainable design and implementation of greywater reuse (GWR) has to achieve an optimum compromise between costs and potable water demand reduction. Studies show that GWR is an efficient tool for reducing potable water demand. This study presents a multi-objective optimization model for estimating the optimal distribution of different types of GWR homes in an existing municipal sewer system. Six types of GWR homes were examined. The model constrains the momentary wastewater (WW) velocity in the sewer pipes (which is responsible for solids movement). The objective functions in the optimization model are the total WW flow at the outlet of the neighborhoods sewer system and the cost of the on-site GWR treatment system. The optimization routing was achieved by an evolutionary multi-objective optimization coupled with hydrodynamic simulations of a representative sewer system of a neighborhood located at the coast of Israel. The two non-dominated best solutions selected were the ones having either the smallest WW flow discharged at the outlet of the neighborhood sewer system or the lowest daily cost.In both solutions most of the GWR types chosen were the types resulting with the smallest water usage. This lead to only a small difference between the two best solutions, regarding the diurnal patterns of the WW flows at the outlet of the neighborhood sewer system. However, in the upstream link a substantial difference was depicted between the diurnal patterns. This difference occurred since to the upstream links only few homes, implementing the same type of GWR, discharge their WW, and in each solution a different type of GWR was implemented in these upstream homes. To the best of our knowledge this is the first multi-objective optimization model aimed at quantitatively trading off the cost of local/onsite GW spatially distributed reuse treatments, and the total amount of WW flow discharged into the municipal sewer system under unsteady flow conditions.

@article{bf3ff376454743fd88d04cacae841d1f,
title = "Multi-objective evolutionary optimization for greywater reuse in municipal sewer systems",
abstract = "Sustainable design and implementation of greywater reuse (GWR) has to achieve an optimum compromise between costs and potable water demand reduction. Studies show that GWR is an efficient tool for reducing potable water demand. This study presents a multi-objective optimization model for estimating the optimal distribution of different types of GWR homes in an existing municipal sewer system. Six types of GWR homes were examined. The model constrains the momentary wastewater (WW) velocity in the sewer pipes (which is responsible for solids movement). The objective functions in the optimization model are the total WW flow at the outlet of the neighborhoods sewer system and the cost of the on-site GWR treatment system. The optimization routing was achieved by an evolutionary multi-objective optimization coupled with hydrodynamic simulations of a representative sewer system of a neighborhood located at the coast of Israel. The two non-dominated best solutions selected were the ones having either the smallest WW flow discharged at the outlet of the neighborhood sewer system or the lowest daily cost.In both solutions most of the GWR types chosen were the types resulting with the smallest water usage. This lead to only a small difference between the two best solutions, regarding the diurnal patterns of the WW flows at the outlet of the neighborhood sewer system. However, in the upstream link a substantial difference was depicted between the diurnal patterns. This difference occurred since to the upstream links only few homes, implementing the same type of GWR, discharge their WW, and in each solution a different type of GWR was implemented in these upstream homes. To the best of our knowledge this is the first multi-objective optimization model aimed at quantitatively trading off the cost of local/onsite GW spatially distributed reuse treatments, and the total amount of WW flow discharged into the municipal sewer system under unsteady flow conditions.",
keywords = "Greywater, Management, Multi-objective, NSGA-II, Operation, Sewer system",
author = "Roni Penn and Friedler Eran and Avi Ostfeld",
note = "Funding Information: This research was partially supported by a grant from Ministry of Science & Technology of the State of Israel and FZK FORSCHUNGSZENTRUM KARLSRUHE and by Israel Water Authority. ",
year = "2013",
month = oct,
day = "1",
doi = "10.1016/j.watres.2013.07.012",
language = "אנגלית",
volume = "47",
pages = "5911--5920",
journal = "Water Research",
issn = "0043-1354",
publisher = "Elsevier Ltd.",
number = "15",

}

Fate of Pesticides and Their Transformation Products: First Flush Effects in a Semi-Arid Catchment

Olsson O, Khodorkovsky M, Gassmann M, Friedler E, Schneider M, Dubowski Y. Fate of Pesticides and Their Transformation Products: First Flush Effects in a Semi-Arid Catchment. Clean - Soil, Air, Water. 2013 Feb;41(2):134-142. https://doi.org/10.1002/clen.201100545
 

Although it is known for many years, that transformation products (TPs) of pesticides are often more persistent, mobile, and sometimes more toxic than the parent compound, former catchment scale studies of substance release and flushing effects focused only on the parent compound. In this study, four river points were sampled in the Hula Valley, Israel, and samples were analyzed in the lab for chlorpyrifos (CP) and endosulfan residues (including transformation products; TPs). Sampling results of the first rainfall in autumn 2009 identified a strong release of most substances to the rivers. First flush effects of these substances were assessed regarding the risk for drinking water supply and ecology, like fresh water invertebrates and fish. Although, these substances were found in Jordan River water during the first significant rainfall the observed levels are below international drinking water guideline values with no adverse effects on human health in the region. However, the observed CP and chlorpyrifos oxon (CPO) levels are above the acute toxicity for fresh water invertebrates and fish. The study shows that the Hula Valley was an important source of pesticides and TPs at the Upper Jordan River basin and that substance flushing is extremely important for pesticides-monitoring campaigns.

@article{d6316d0aec6e449994e3710a90707fbb,
title = "Fate of Pesticides and Their Transformation Products: First Flush Effects in a Semi-Arid Catchment",
abstract = "Although it is known for many years, that transformation products (TPs) of pesticides are often more persistent, mobile, and sometimes more toxic than the parent compound, former catchment scale studies of substance release and flushing effects focused only on the parent compound. In this study, four river points were sampled in the Hula Valley, Israel, and samples were analyzed in the lab for chlorpyrifos (CP) and endosulfan residues (including transformation products; TPs). Sampling results of the first rainfall in autumn 2009 identified a strong release of most substances to the rivers. First flush effects of these substances were assessed regarding the risk for drinking water supply and ecology, like fresh water invertebrates and fish. Although, these substances were found in Jordan River water during the first significant rainfall the observed levels are below international drinking water guideline values with no adverse effects on human health in the region. However, the observed CP and chlorpyrifos oxon (CPO) levels are above the acute toxicity for fresh water invertebrates and fish. The study shows that the Hula Valley was an important source of pesticides and TPs at the Upper Jordan River basin and that substance flushing is extremely important for pesticides-monitoring campaigns.",
keywords = "Assessment, Chlorpyrifos residues, Endosulfan residues, Monitoring, Upper Jordan River, Water quality",
author = "Oliver Olsson and Miriam Khodorkovsky and Matthias Gassmann and Eran Friedler and Mandy Schneider and Yael Dubowski",
year = "2013",
month = feb,
doi = "10.1002/clen.201100545",
language = "אנגלית",
volume = "41",
pages = "134--142",
journal = "Clean - Soil, Air, Water",
issn = "1863-0650",
publisher = "Wiley-VCH Verlag",
number = "2",

}

Integrated hydro-economic assessment of restoration of the Alexander-Zeimar River (Israel-Palestinian Authority)

Becker N, Friedler E. Integrated hydro-economic assessment of restoration of the Alexander-Zeimar River (Israel-Palestinian Authority). Regional Environmental Change. 2013 Feb;13(1):103-114. https://doi.org/10.1007/s10113-012-0318-1
 

This paper examines hydro-economic aspects of the Alexander-Zeimar basin. The Alexander-Zeimar River is a transboundary river originating in the Palestinian Authority and flowing through Israel to the Mediterranean Sea. Since the 1950s, the river has been used as a sewage outlet. The major purpose of this study is to estimate the costs and benefits derived from a restoration plan, which has been in place in the river since the mid-1990s. A hydrological model combined with market and non-market valuation (travel cost method) techniques was used to estimate the condition of the situation before and after the restoration project was implemented. The total restoration plan was compared to alternative partial plans. Interestingly, a cost-benefit analysis on the different restoration options revealed that only a complete cleanup of the river results in a positive net benefit ($0. 49-3. 23 million annually).

@article{0aa0c3c369334496a123e7abe8463467,
title = "Integrated hydro-economic assessment of restoration of the Alexander-Zeimar River (Israel-Palestinian Authority)",
abstract = "This paper examines hydro-economic aspects of the Alexander-Zeimar basin. The Alexander-Zeimar River is a transboundary river originating in the Palestinian Authority and flowing through Israel to the Mediterranean Sea. Since the 1950s, the river has been used as a sewage outlet. The major purpose of this study is to estimate the costs and benefits derived from a restoration plan, which has been in place in the river since the mid-1990s. A hydrological model combined with market and non-market valuation (travel cost method) techniques was used to estimate the condition of the situation before and after the restoration project was implemented. The total restoration plan was compared to alternative partial plans. Interestingly, a cost-benefit analysis on the different restoration options revealed that only a complete cleanup of the river results in a positive net benefit ($0. 49-3. 23 million annually).",
keywords = "Cost-benefit analysis, Integrated river basin management, Travel cost method",
author = "Nir Becker and Eran Friedler",
note = "Funding Information: Acknowledgments This research was performed within the framework of OPTIMA (Optimization for Sustainable Water Management) and funded by the EU (Contract No. INCO-CT-2004-509091). The authors further wish to thank David Troupin from the Technion for producing the maps and Jane Morrison from McGill Univ. and Jennifer Helgeson from the London School of Economics as well as the editor and two anonymous referees for their helpful comments.",
year = "2013",
month = feb,
doi = "10.1007/s10113-012-0318-1",
language = "אנגלית",
volume = "13",
pages = "103--114",
journal = "Regional Environmental Change",
issn = "1436-3798",
publisher = "Springer Verlag",
number = "1",

}

Modelling the effects of on-site greywater reuse and low flush toilets on municipal sewer systems

Penn R, Schütze M, Friedler E. Modelling the effects of on-site greywater reuse and low flush toilets on municipal sewer systems. Journal of Environmental Management. 2013 Jan 5;114:72-83. https://doi.org/10.1016/j.jenvman.2012.10.044
 

On-site greywater reuse (GWR) and installation of water-efficient toilets (WET) reduce urban freshwater demand. Research on GWR and WET has generally overlooked the effects that GWR may have on municipal sewer systems. This paper discusses and quantifies these effects. The effects of GWR and WET, positive and negative, were studied by modelling a representative urban sewer system. GWR scenarios were modelled and analysed using the SIMBA simulation system. The results show that, as expected, the flow, velocity and proportional depth decrease as GWR increases. Nevertheless, the reduction is not evenly distributed throughout the day but mainly occurs during the morning and evening peaks. Examination of the effects of reduced toilet flush volumes revealed that in some of the GWR scenarios flows, velocities and proportional depths in the sewer were reduced, while in other GWR scenarios discharge volumes, velocities and proportional depths did not change. Further, it is indicated that as a result of GWR and installation of WET, sewer blockage rates are not expected to increase significantly. The results support the option to construct new sewer systems with smaller pipe diameters. The analysis shows that as the penetration of GWR systems increase, and with the installation of WET, concentrations of pollutants also increase. In GWR scenarios (when toilet flush volume is not reduced) the increase in pollutant concentrations is lower than the proportional reduction of sewage flow. Moreover, the results show that the spatial distribution of houses reusing GW does not significantly affect the parameters examined.

@article{7e452a4edc634a2fb9ac75ad48b1c593,
title = "Modelling the effects of on-site greywater reuse and low flush toilets on municipal sewer systems",
abstract = "On-site greywater reuse (GWR) and installation of water-efficient toilets (WET) reduce urban freshwater demand. Research on GWR and WET has generally overlooked the effects that GWR may have on municipal sewer systems. This paper discusses and quantifies these effects. The effects of GWR and WET, positive and negative, were studied by modelling a representative urban sewer system. GWR scenarios were modelled and analysed using the SIMBA simulation system. The results show that, as expected, the flow, velocity and proportional depth decrease as GWR increases. Nevertheless, the reduction is not evenly distributed throughout the day but mainly occurs during the morning and evening peaks. Examination of the effects of reduced toilet flush volumes revealed that in some of the GWR scenarios flows, velocities and proportional depths in the sewer were reduced, while in other GWR scenarios discharge volumes, velocities and proportional depths did not change. Further, it is indicated that as a result of GWR and installation of WET, sewer blockage rates are not expected to increase significantly. The results support the option to construct new sewer systems with smaller pipe diameters. The analysis shows that as the penetration of GWR systems increase, and with the installation of WET, concentrations of pollutants also increase. In GWR scenarios (when toilet flush volume is not reduced) the increase in pollutant concentrations is lower than the proportional reduction of sewage flow. Moreover, the results show that the spatial distribution of houses reusing GW does not significantly affect the parameters examined.",
keywords = "Discharge, Diurnal pattern, Greywater reuse, Low flush toilets, Municipal sewers, Quality",
author = "R. Penn and M. Sch{\"u}tze and E. Friedler",
note = "Funding Information: This research was partially funded by the Grand Water Research Institute , Technion and Israel Water Authority . One of us (R. P.) would like to thank YSEP (Young Scientists Exchange Programme) of BMBF (Germany) – MOST (Israel) that enabled a visit to ifak for a research stay. The authors further wish to thank Ms. Jane Morrison from McGill Univ. Canada for her helpful comments.",
year = "2013",
month = jan,
day = "5",
doi = "10.1016/j.jenvman.2012.10.044",
language = "אנגלית",
volume = "114",
pages = "72--83",
journal = "Journal of Environmental Management",
issn = "0301-4797",
publisher = "Academic Press Inc.",

}

Polyaluminium chloride as an alternative to alum for the direct filtration of drinking water

Zarchi I, Friedler E, Rebhun M. Polyaluminium chloride as an alternative to alum for the direct filtration of drinking water. Environmental Technology (United Kingdom). 2013;34(9):1199-1209. https://doi.org/10.1080/09593330.2012.743594
 

The efficiency of various polyaluminium chloride coagulants (PACls) was compared to the efficiency of aluminium sulfate (alum) in the coagulation-flocculation process preceding direct filtration in drinking water treatment. The comparative study consisted of two separate yet complementary series of experiments: the first series included short (5-7 h) and long (24 h) filter runs conducted at a pilot filtration plant equipped with large filter columns that simulated full-scale filters. Partially treated surface water from the Sea of Galilee, characterized by very low turbidity (~1 NTU), was used. In the second series of experiments, speciation of aluminium in situ was investigated using the ferron assay method. Results from the pilot-scale study indicate that most PACls were as or more efficient a coagulant as alum for direct filtration of surface water without requiring acid addition for pH adjustment and subsequent base addition for re-stabilizing the water. Consequently, cost analysis of the chemicals needed for the process showed that treatment with PACl would be significantly less costly than treatment with alum. The aluminium speciation experiments revealed that the performance of the coagulant is more influenced by the species present during the coagulation process than those present in the original reagents.

@article{3e0466cc379f4887a9f8671e90c01b48,
title = "Polyaluminium chloride as an alternative to alum for the direct filtration of drinking water",
abstract = "The efficiency of various polyaluminium chloride coagulants (PACls) was compared to the efficiency of aluminium sulfate (alum) in the coagulation-flocculation process preceding direct filtration in drinking water treatment. The comparative study consisted of two separate yet complementary series of experiments: the first series included short (5-7 h) and long (24 h) filter runs conducted at a pilot filtration plant equipped with large filter columns that simulated full-scale filters. Partially treated surface water from the Sea of Galilee, characterized by very low turbidity (~1 NTU), was used. In the second series of experiments, speciation of aluminium in situ was investigated using the ferron assay method. Results from the pilot-scale study indicate that most PACls were as or more efficient a coagulant as alum for direct filtration of surface water without requiring acid addition for pH adjustment and subsequent base addition for re-stabilizing the water. Consequently, cost analysis of the chemicals needed for the process showed that treatment with PACl would be significantly less costly than treatment with alum. The aluminium speciation experiments revealed that the performance of the coagulant is more influenced by the species present during the coagulation process than those present in the original reagents.",
keywords = "Alum, Direct filtration, Drinking water treatment, PACl, Speciation",
author = "Idit Zarchi and Eran Friedler and Menahem Rebhun",
note = "Funding Information: This research was supported by Mekorot – Israel{\textquoteright}s national water company.",
year = "2013",
doi = "10.1080/09593330.2012.743594",
language = "אנגלית",
volume = "34",
pages = "1199--1209",
journal = "Environmental Technology (United Kingdom)",
issn = "0959-3330",
publisher = "Taylor and Francis Ltd.",
number = "9",

}

Reliability of on-site greywater treatment systems in Mediterranean and arid environments - A case study

Alfiya Y, Gross A, Sklarz M, Friedler E. Reliability of on-site greywater treatment systems in Mediterranean and arid environments - A case study. Water Science and Technology. 2013;67(6):1389-1395. https://doi.org/10.2166/wst.2013.687
 

On-site greywater (GW) treatment and reuse is gaining popularity. However, a main point of concern is that inadequate treatment of such water may lead to negative environmental and health effects. Maintenance of single-family home GW systems is usually performed by home owners with limited professional support. Therefore, unless GW systems are reliable, environmental and public health might be compromised. This study is aimed at investigating the reliability of on-site recirculated vertical flow constructed wetlands (RVFCW) in 20 single-family homes. In order to ensure reliability, the failure-tree approach was adopted during the design and construction of the systems. The performance of the systems was monitored for 1.5 years, by evaluating treated GW flow and quality, and by recording all malfunctions and maintenance work. Only 39 failures occurred during this period, of which four caused irrigation with impaired quality GW, while the rest led to no irrigation. The mean time between failures (MTBF) was 305 days; two out of the 20 systems suffered from seven malfunctions (each), while nine systems did not fail at all. Thus, it can be postulated that if onsite GW treatment systems are designed with the right controls, and if scheduled (basic and relatively infrequent) maintenance is performed, GW reuse can be safe to the environment and human health.

@article{29f0b530a8da4b609a323ee6c3776da0,
title = "Reliability of on-site greywater treatment systems in Mediterranean and arid environments - A case study",
abstract = "On-site greywater (GW) treatment and reuse is gaining popularity. However, a main point of concern is that inadequate treatment of such water may lead to negative environmental and health effects. Maintenance of single-family home GW systems is usually performed by home owners with limited professional support. Therefore, unless GW systems are reliable, environmental and public health might be compromised. This study is aimed at investigating the reliability of on-site recirculated vertical flow constructed wetlands (RVFCW) in 20 single-family homes. In order to ensure reliability, the failure-tree approach was adopted during the design and construction of the systems. The performance of the systems was monitored for 1.5 years, by evaluating treated GW flow and quality, and by recording all malfunctions and maintenance work. Only 39 failures occurred during this period, of which four caused irrigation with impaired quality GW, while the rest led to no irrigation. The mean time between failures (MTBF) was 305 days; two out of the 20 systems suffered from seven malfunctions (each), while nine systems did not fail at all. Thus, it can be postulated that if onsite GW treatment systems are designed with the right controls, and if scheduled (basic and relatively infrequent) maintenance is performed, GW reuse can be safe to the environment and human health.",
keywords = "Failure-tree analysis, Greywater reuse, Mean time between failures, On-site treatment, Reliability",
author = "Y. Alfiya and A. Gross and M. Sklarz and E. Friedler",
year = "2013",
doi = "10.2166/wst.2013.687",
language = "אנגלית",
volume = "67",
pages = "1389--1395",
journal = "Water Science and Technology",
issn = "0273-1223",
publisher = "IWA Publishing",
number = "6",

}

Wastewater composition

Friedler E, Butler D, Alfiya Y. Wastewater composition. In Larsen T, Udert K, Linert J, editors, Source Separation and Decentralization for Wastewater Management. IWA Publishing. 2013. p. 241 https://doi.org/https://doi.org/10.2166/9781780401072
@inbook{1d3f0a48ef1d4026813daec550f585c7,
title = "Wastewater composition",
author = "Eran Friedler and David Butler and Yuval Alfiya",
year = "2013",
doi = "https://doi.org/10.2166/9781780401072",
language = "American English",
isbn = "9781306301435",
pages = "241",
editor = "T Larsen and K Udert and J Linert",
booktitle = "Source Separation and Decentralization for Wastewater Management",
publisher = "IWA Publishing",
address = "United Kingdom",

}

חומרי הדברה ותוצרי פירוקם - שטיפה באירועי גשם ראשונים (first flush) לנחלי אגן החולה

דובובסקי י, חודורקובסקי מ, אולסון א, גסמן מ, פרידלר ע. חומרי הדברה ותוצרי פירוקם - שטיפה באירועי גשם ראשונים (first flush) לנחלי אגן החולה. אקולוגיה וסביבה. 2013;4(1):24-27.
 
עמק החולה הינו מקור משמעותי של חומרי הדברה ותוצרי הפירוק שלהם באגן ההיקוות של הירדן העליון. לשם הערכת ההשפעה הסביבתית של חומרי ההדברה הנשטפים אל הנחלים יש לבצע ניטור של חומרי ההדברה והן של תוצרי פירוקם. לפי התצפיות ופעילות חקלאית באזור יש למצוא פתרונות לצמצום השימוש בחומרי הדברה מבלי לפגוע בייצור החקלאי. Refereed/Peer-reviewed
@article{0d87d0f8210b4f48b0b40d91204fae6f,
title = "חומרי הדברה ותוצרי פירוקם - שטיפה באירועי גשם ראשונים (first flush) לנחלי אגן החולה",
abstract = "עמק החולה הינו מקור משמעותי של חומרי הדברה ותוצרי הפירוק שלהם באגן ההיקוות של הירדן העליון. לשם הערכת ההשפעה הסביבתית של חומרי ההדברה הנשטפים אל הנחלים יש לבצע ניטור של חומרי ההדברה והן של תוצרי פירוקם. לפי התצפיות ופעילות חקלאית באזור יש למצוא פתרונות לצמצום השימוש בחומרי הדברה מבלי לפגוע בייצור החקלאי. Refereed/Peer-reviewed",
author = "יעל דובובסקי and מרים חודורקובסקי and אוליבר אולסון and מתיאס גסמן and ערן פרידלר",
year = "2013",
language = "עברית",
volume = "4",
pages = "24--27",
journal = "אקולוגיה וסביבה",
number = "1",

}

2012

Evaluation of the effects of greywater reuse on domestic wastewater quality and quantity

Penn R, Hadari M, Friedler E. Evaluation of the effects of greywater reuse on domestic wastewater quality and quantity. Urban Water Journal. 2012 Jun;9(3):137-148. https://doi.org/10.1080/1573062X.2011.652132
 

This simulation study, based on experimental and literature data, evaluates the influence of onsite greywater reuse on domestic wastewater quality and quantity. For this, three scenarios were studied: no reuse; reuse for toilet flushing; reuse for toilet flushing and garden irrigation. Light greywater reuse reduced the daily household wastewater flows by 25-40%. These reductions mainly occurred during the morning and evening peak wastewater generation. Although daily loads of all pollutants decreased, their concentrations in the discharged wastewater increased owing to exclusion of potable water from the wastewater and replacing it by treated light greywater. The proportional concentration increase of most pollutants was lower than the decrease in wastewater discharge, due to degradation during treatment. The highest concentration increase occurred during the morning peak, coinciding with the highest flow reduction. This study is a first step towards quantification of the effects of onsite greywater reuse on sewers and wastewater treatment plants.

@article{7cb803650de743e7b861b6727e711756,
title = "Evaluation of the effects of greywater reuse on domestic wastewater quality and quantity",
abstract = "This simulation study, based on experimental and literature data, evaluates the influence of onsite greywater reuse on domestic wastewater quality and quantity. For this, three scenarios were studied: no reuse; reuse for toilet flushing; reuse for toilet flushing and garden irrigation. Light greywater reuse reduced the daily household wastewater flows by 25-40%. These reductions mainly occurred during the morning and evening peak wastewater generation. Although daily loads of all pollutants decreased, their concentrations in the discharged wastewater increased owing to exclusion of potable water from the wastewater and replacing it by treated light greywater. The proportional concentration increase of most pollutants was lower than the decrease in wastewater discharge, due to degradation during treatment. The highest concentration increase occurred during the morning peak, coinciding with the highest flow reduction. This study is a first step towards quantification of the effects of onsite greywater reuse on sewers and wastewater treatment plants.",
keywords = "domestic wastewater, greywater, onsite reuse, quality, quantity",
author = "Roni Penn and Matan Hadari and Eran Friedler",
note = "Funding Information: This research was partially supported by Israel Water Authority and by The Grand Water Research Institute, Technion. The authors further wish to thank the anonymous reviewers for their thorough and instrumental review.",
year = "2012",
month = jun,
doi = "10.1080/1573062X.2011.652132",
language = "אנגלית",
volume = "9",
pages = "137--148",
journal = "Urban Water Journal",
issn = "1573-062X",
publisher = "Taylor and Francis Ltd.",
number = "3",

}

Some observations on biofouling prediction in pipelines using model trees and artificial neural networks versus logistic regression

Opher T, Rom M, Kronaveter L, Friedler E, Ostfeld A. Some observations on biofouling prediction in pipelines using model trees and artificial neural networks versus logistic regression. Urban Water Journal. 2012 Feb;9(1):11-20. https://doi.org/10.1080/1573062X.2011.633611
 

Biofouling is the phenomenon of micro-organism attachments to wet surfaces. Complete understanding of the mechanisms and rates of biofilms creations are partially understood therefore forecasting their formations is difficult. This study is on biofouling predictions for water distribution systems pipelines using model trees, artificial neural networks, and logistic regression. The three methods were tested through base runs and sensitivity analysis runs using data from the experiment conducted by Simões et al. (2006). The results showed that none of the models were superior for all cases, therefore a single model could not be recommended. This leads to an important conclusion that utilising 'low cost' modelling methods such as logistic regression can be sufficient for providing reliable estimates for biofilm growth potential. 'Low cost' approaches should be applied prior to invoking expensive models such as data driven methods as the latter might not be needed.

@article{87f12dc8650f47cdaa2f850a5978c161,
title = "Some observations on biofouling prediction in pipelines using model trees and artificial neural networks versus logistic regression",
abstract = "Biofouling is the phenomenon of micro-organism attachments to wet surfaces. Complete understanding of the mechanisms and rates of biofilms creations are partially understood therefore forecasting their formations is difficult. This study is on biofouling predictions for water distribution systems pipelines using model trees, artificial neural networks, and logistic regression. The three methods were tested through base runs and sensitivity analysis runs using data from the experiment conducted by Sim{\~o}es et al. (2006). The results showed that none of the models were superior for all cases, therefore a single model could not be recommended. This leads to an important conclusion that utilising 'low cost' modelling methods such as logistic regression can be sufficient for providing reliable estimates for biofilm growth potential. 'Low cost' approaches should be applied prior to invoking expensive models such as data driven methods as the latter might not be needed.",
keywords = "biofouling, data driven modelling, logistic regression, model, pipeline",
author = "Tamar Opher and Meir Rom and Lea Kronaveter and Eran Friedler and Avi Ostfeld",
note = "Funding Information: This work was supported in part by the Israeli Ministry of Industry and Trade under project MAGNET Biofouling Consortium.",
year = "2012",
month = feb,
doi = "10.1080/1573062X.2011.633611",
language = "אנגלית",
volume = "9",
pages = "11--20",
journal = "Urban Water Journal",
issn = "1573-062X",
publisher = "Taylor and Francis Ltd.",
number = "1",

}

Macroeconomic benefits of onsite greywater recycling in semiarid regions suffering from water scarcity - Israel as a case study

Adel ME, Friedler E. Macroeconomic benefits of onsite greywater recycling in semiarid regions suffering from water scarcity - Israel as a case study. In WSUD 2012 - 7th International Conference on Water Sensitive Urban Design: Building the Water Sensitive Community, Final Program and Abstract Book. 2012. (WSUD 2012 - 7th International Conference on Water Sensitive Urban Design: Building the Water Sensitive Community, Final Program and Abstract Book).
 

Unlike other leading water policy nations such as Australia, Canada, Germany, Singapore, the UK and the USA regulatory difficulties prevent Israel from taking advantage of a major water savings opportunity in onsite greywater recycling (GWR) to address its existing and projected long term water deficit. Despite absence of local or international evidence indicating the epidemiological risks, Israel's Ministry of Health continues to actively block any effort to legalise GWR in the residential sector which stands for more than 90% of the national GWR potential. The analysis in this paper relies on a simple model which has been accepted by regulators in all the above mentioned countries. It assumes greywater (i.e. shower, bath, washbasin and laundry water) is recycled onsite and reused primarily for toilet flushing and secondarily for garden irrigation. Although capital and ongoing costs are borne by the taxpayer, the average family cost of living can still be reduced by greywater recycling in the medium and long term. More significant however are the macroeconomic benefits. By 2050 greywater recycling, if widely implemented, can reduce Israel's national water and electricity consumption by 150250 million m3 and 12 TW·h (1 TW = 109 kW) per year respectively. Cumulative savings to Israel's national economy are estimated to be between 3060 billion NIS (816 billion US$) by 2050. This is primarily enabled by reductions in infrastructure spending on water production and distribution since greywater recycling produces a viable alternative for high value potable water exactly where it is needed - on location in high density urban settings. On the other hand, desalination which is the mainstay of the current plan to mitigate current and future water scarcity produces water at sea level and tens to hundreds of kilometers away from the consumer in a process which requires of the order of 4 times more energy per cubic meter of water than greywater recycling. As any desalination engineer knows - it is the last and most expensive option. Onsite decentralised greywater recycling should be, but is not currently, given national priority as a measure to reduce and complement the pressing need for seawater desalination.

@inproceedings{6bf6f9195d0d44588f168a03a8c4aa74,
title = "Macroeconomic benefits of onsite greywater recycling in semiarid regions suffering from water scarcity - Israel as a case study",
abstract = "Unlike other leading water policy nations such as Australia, Canada, Germany, Singapore, the UK and the USA regulatory difficulties prevent Israel from taking advantage of a major water savings opportunity in onsite greywater recycling (GWR) to address its existing and projected long term water deficit. Despite absence of local or international evidence indicating the epidemiological risks, Israel's Ministry of Health continues to actively block any effort to legalise GWR in the residential sector which stands for more than 90% of the national GWR potential. The analysis in this paper relies on a simple model which has been accepted by regulators in all the above mentioned countries. It assumes greywater (i.e. shower, bath, washbasin and laundry water) is recycled onsite and reused primarily for toilet flushing and secondarily for garden irrigation. Although capital and ongoing costs are borne by the taxpayer, the average family cost of living can still be reduced by greywater recycling in the medium and long term. More significant however are the macroeconomic benefits. By 2050 greywater recycling, if widely implemented, can reduce Israel's national water and electricity consumption by 150250 million m3 and 12 TW·h (1 TW = 109 kW) per year respectively. Cumulative savings to Israel's national economy are estimated to be between 3060 billion NIS (816 billion US$) by 2050. This is primarily enabled by reductions in infrastructure spending on water production and distribution since greywater recycling produces a viable alternative for high value potable water exactly where it is needed - on location in high density urban settings. On the other hand, desalination which is the mainstay of the current plan to mitigate current and future water scarcity produces water at sea level and tens to hundreds of kilometers away from the consumer in a process which requires of the order of 4 times more energy per cubic meter of water than greywater recycling. As any desalination engineer knows - it is the last and most expensive option. Onsite decentralised greywater recycling should be, but is not currently, given national priority as a measure to reduce and complement the pressing need for seawater desalination.",
author = "Adel, {M. E.} and E. Friedler",
year = "2012",
language = "אנגלית",
isbn = "9780858258952",
series = "WSUD 2012 - 7th International Conference on Water Sensitive Urban Design: Building the Water Sensitive Community, Final Program and Abstract Book",
booktitle = "WSUD 2012 - 7th International Conference on Water Sensitive Urban Design",
note = "7th International Conference on Water Sensitive Urban Design, WSUD 2012 ; Conference date: 21-02-2012 Through 23-02-2012",

}

Potential impacts of on-site greywater reuse in landscape irrigation

Alfiya Y, Damti O, Stoler-Katz A, Zoubi A, Shaviv A, Friedler E. Potential impacts of on-site greywater reuse in landscape irrigation. Water Science and Technology. 2012;65(4):757-764. https://doi.org/10.2166/wst.2012.903
 

This study investigated the effects of irrigation with different types of waters on soil, plants, and public health. The test plant was ryegrass grown in 12 planters filled with sandy loam soil and irrigated with three types of waters (4 planters for each type): freshwater, raw domestic light greywater (GW), and treated domestic light GW. The sodium adsorption ratio (SAR), EC, pH and alkalinity of the three types of irrigation waters did not differ significantly, suggesting that raw or treated light GW should not exhibit negative effects. Concentrations of anionic and cationic surfactants in the freshwater and the treated GW were about the same, while their concentrations in the raw GW were higher. Surfactant levels in the three drainage water types were low. Some accumulation of surfactants occurred in planters irrigated with raw and treated GW. The COD of the drainage water of planters irrigated with raw GW was higher than the COD of other two drainage water types. Although raw and treated GW contained faecal coliforms, they were hardly detected in the drainage waters. All plants did not show any signs of stress. This may be due to the fact that the GW originated mainly from showers and washbasins.

@article{6d8db3e52f224dc08f23d1c43d9d5d9d,
title = "Potential impacts of on-site greywater reuse in landscape irrigation",
abstract = "This study investigated the effects of irrigation with different types of waters on soil, plants, and public health. The test plant was ryegrass grown in 12 planters filled with sandy loam soil and irrigated with three types of waters (4 planters for each type): freshwater, raw domestic light greywater (GW), and treated domestic light GW. The sodium adsorption ratio (SAR), EC, pH and alkalinity of the three types of irrigation waters did not differ significantly, suggesting that raw or treated light GW should not exhibit negative effects. Concentrations of anionic and cationic surfactants in the freshwater and the treated GW were about the same, while their concentrations in the raw GW were higher. Surfactant levels in the three drainage water types were low. Some accumulation of surfactants occurred in planters irrigated with raw and treated GW. The COD of the drainage water of planters irrigated with raw GW was higher than the COD of other two drainage water types. Although raw and treated GW contained faecal coliforms, they were hardly detected in the drainage waters. All plants did not show any signs of stress. This may be due to the fact that the GW originated mainly from showers and washbasins.",
keywords = "Greywater, Landscape irrigation, Microbial quality, On-site, Ryegrass, SAR, Soil",
author = "Y. Alfiya and O. Damti and A. Stoler-Katz and A. Zoubi and A. Shaviv and E. Friedler",
year = "2012",
doi = "10.2166/wst.2012.903",
language = "אנגלית",
volume = "65",
pages = "757--764",
journal = "Water Science and Technology",
issn = "0273-1223",
publisher = "IWA Publishing",
number = "4",

}

השפעות של שימוש חוזר במים אפורים על מערכות הביוב העירוניות

פן ר, שוטצה מ, פרידלר ע. השפעות של שימוש חוזר במים אפורים על מערכות הביוב העירוניות. מים והשקיה: ירחון ארגון עובדי המים. 2012;525:12-17.
 
כצפוי, עם העלייה בחדירת מערכות מיחזור מים אפורים, ריכוזי המזהמים במי הביוב צפויים לעלות אך קצב היווצרות הסתימות לא צפוי לגדול. כן מסתמן, כי ניתן יהיה להקים מערכות ביוב חדשות עם צנרת בקטרים קטנים יותר או לחבר תורמים נוספים למערכות קיימות. המאמר בחן השפעות של שינויים בספיקות השפכים ובריכוזי המזהמים המשוחררים מבית בודד, בשל שימוש חוזר במים אפורים, על מערכת הביוב העירונית. (מתוך המאמר)
@article{1a034296b3b64541b560186f89be24ae,
title = "השפעות של שימוש חוזר במים אפורים על מערכות הביוב העירוניות",
abstract = "כצפוי, עם העלייה בחדירת מערכות מיחזור מים אפורים, ריכוזי המזהמים במי הביוב צפויים לעלות אך קצב היווצרות הסתימות לא צפוי לגדול. כן מסתמן, כי ניתן יהיה להקים מערכות ביוב חדשות עם צנרת בקטרים קטנים יותר או לחבר תורמים נוספים למערכות קיימות. המאמר בחן השפעות של שינויים בספיקות השפכים ובריכוזי המזהמים המשוחררים מבית בודד, בשל שימוש חוזר במים אפורים, על מערכת הביוב העירונית. (מתוך המאמר)",
author = "רוני פן and מנפרד שוטצה and ערן פרידלר",
year = "2012",
language = "עברית",
volume = "525",
pages = "12--17",
journal = "מים והשקיה: ירחון ארגון עובדי המים",
issn = "0333-8835",

}

2011

Fuel derived pollutants and boating activity patterns in the sea of galilee

Dinerman E, Dubowski Y, Friedler E. Fuel derived pollutants and boating activity patterns in the sea of galilee. Journal of Environmental Management. 2011 Nov;92(11):3002-3010. https://doi.org/10.1016/j.jenvman.2011.07.015
 

MTBE (Methyl tert-Butyl Ether) is a fuel additive that replaced lead as an antiknock compound in internal combustion motors. Few years after its introduction, detectable levels of MTBE were found in various water bodies. MTBE has a very low taste and odor threshold and is a potential carcinogen. Another group of fuel derived toxic compounds that has been detected in water bodies is BTEX (Benzene, Toluene, Ethylbenzene and Xylene). Boating activity and allochthonous contributions from watersheds are the major sources of fuel derived pollutants in lakes. Their concentrations in lakes thus vary as a function of boating activity intensity, lake surface area and depth, weather and wind regime, land-use in the watershed, etc. The Sea of Galilee (Lake Kinneret) is the only recreational lake in Israel and an important freshwater source. In the current study, a sampling campaign was conducted in order to quantify MTBE and BTEX concentrations in Lake Kinneret, its marinas and its main contributing streams. In addition, a boating-use survey was performed in order to estimate MTBE and BTEX contribution of recreational boating. The sampling campaign revealed that, as expected, MTBE concentrations were higher than BTEX, and that near shore (i.e., marina) concentrations were higher than in-lake concentrations. Despite the clear contribution from boating, high MTBE concentrations were found following a major inflow event in winter, indicating the importance of the allochthonous contribution. The contribution from boating during summer, as measured indirectly by in-lake concentrations, is likely underestimated due to enhanced MTBE volatilization due to strong winds and high temperatures. May-September was found to be the main recreational boating season, with continued boating year round. On average, a single boat is active 23 d/y, with 84% of the watercrafts being active only during weekends and holidays. The survey further indicated that boats stay in the lake for 4.5 h on average, which conforms to the unique winds regime that limits afternoon activity due to high winds, and have an average fuel consumption of 14 L/h. The annual load of MTBE and BTEX from recreational boating in Lake Kinneret was estimated at 4430 and 6220 kg/y respectively.

@article{5ad411be9bed40ec8310f81b4683b616,
title = "Fuel derived pollutants and boating activity patterns in the sea of galilee",
abstract = "MTBE (Methyl tert-Butyl Ether) is a fuel additive that replaced lead as an antiknock compound in internal combustion motors. Few years after its introduction, detectable levels of MTBE were found in various water bodies. MTBE has a very low taste and odor threshold and is a potential carcinogen. Another group of fuel derived toxic compounds that has been detected in water bodies is BTEX (Benzene, Toluene, Ethylbenzene and Xylene). Boating activity and allochthonous contributions from watersheds are the major sources of fuel derived pollutants in lakes. Their concentrations in lakes thus vary as a function of boating activity intensity, lake surface area and depth, weather and wind regime, land-use in the watershed, etc. The Sea of Galilee (Lake Kinneret) is the only recreational lake in Israel and an important freshwater source. In the current study, a sampling campaign was conducted in order to quantify MTBE and BTEX concentrations in Lake Kinneret, its marinas and its main contributing streams. In addition, a boating-use survey was performed in order to estimate MTBE and BTEX contribution of recreational boating. The sampling campaign revealed that, as expected, MTBE concentrations were higher than BTEX, and that near shore (i.e., marina) concentrations were higher than in-lake concentrations. Despite the clear contribution from boating, high MTBE concentrations were found following a major inflow event in winter, indicating the importance of the allochthonous contribution. The contribution from boating during summer, as measured indirectly by in-lake concentrations, is likely underestimated due to enhanced MTBE volatilization due to strong winds and high temperatures. May-September was found to be the main recreational boating season, with continued boating year round. On average, a single boat is active 23 d/y, with 84% of the watercrafts being active only during weekends and holidays. The survey further indicated that boats stay in the lake for 4.5 h on average, which conforms to the unique winds regime that limits afternoon activity due to high winds, and have an average fuel consumption of 14 L/h. The annual load of MTBE and BTEX from recreational boating in Lake Kinneret was estimated at 4430 and 6220 kg/y respectively.",
keywords = "BTEX, Boating survey, Lake Kinneret, MTBE, Watershed contribution",
author = "Efrat Dinerman and Yael Dubowski and Eran Friedler",
note = "Funding Information: The research was supported by the Israel Water Authority and by the Grand Water Research Institute, Technion . The authors further wish to thank Dr. D. Markel from Israel Water Authority and Mr. Y. Nitzani from the Lake Kinneret Authority for their invaluable support. ",
year = "2011",
month = nov,
doi = "10.1016/j.jenvman.2011.07.015",
language = "אנגלית",
volume = "92",
pages = "3002--3010",
journal = "Journal of Environmental Management",
issn = "0301-4797",
publisher = "Academic Press Inc.",
number = "11",

}

Disinfection of greywater effluent and regrowth potential of selected bacteria

Friedler E, Yardeni A, Gilboa Y, Alfiya Y. Disinfection of greywater effluent and regrowth potential of selected bacteria. Water Science and Technology. 2011;63(5):931-940. https://doi.org/10.2166/wst.2011.272
 

Chlorination and UV irradiation of RBC (rotating biological contactor)-treated light GW (greywater) was investigated. The ability of chlorine and UV to inactivate indictor bacteria (FC - Faecal Coliforms, HPC - Heterotrophic Plate Count) and specific pathogens (P.a. - Pseudomonas aeruginosa sp., S.a. - Staphylococcus aureus sp.), was assessed and their regrowth potential was examined. The RBC removed 88.5-99.9% of all four bacteria groups. Nevertheless, the treated GW had to be disinfected. Most of the chlorine was consumed during the first 0.5 h, while later its decay rate decreased significantly, leaving enough residual after 6 h to prevent regrowth and to further inactivate bacteria in the stored GW effluent. Under exposure to low UV doses (≤69 mJ/cm2) FC was the most resistant bacteria group, followed by HPC, P.a. and S.a. Exposure to higher doses (≤439 mJs/cm 2) completely inactivated FC, P.a. and S.a., while no further HPC inactivation was observed. FC, P.a. and S.a. did not exhibit regrowth after exposure to all the UV doses applied (up to 6 h storage). HPC did not exhibit regrowth after exposure to low UV doses (19-69 mJ/cm2), while it presented statistically significant regrowth in un-disinfected effluent and after exposure to higher UV doses (147-439 mJ/cm2).

@article{c9eb0f3e601644149b06bee05b06d5ba,
title = "Disinfection of greywater effluent and regrowth potential of selected bacteria",
abstract = "Chlorination and UV irradiation of RBC (rotating biological contactor)-treated light GW (greywater) was investigated. The ability of chlorine and UV to inactivate indictor bacteria (FC - Faecal Coliforms, HPC - Heterotrophic Plate Count) and specific pathogens (P.a. - Pseudomonas aeruginosa sp., S.a. - Staphylococcus aureus sp.), was assessed and their regrowth potential was examined. The RBC removed 88.5-99.9% of all four bacteria groups. Nevertheless, the treated GW had to be disinfected. Most of the chlorine was consumed during the first 0.5 h, while later its decay rate decreased significantly, leaving enough residual after 6 h to prevent regrowth and to further inactivate bacteria in the stored GW effluent. Under exposure to low UV doses (≤69 mJ/cm2) FC was the most resistant bacteria group, followed by HPC, P.a. and S.a. Exposure to higher doses (≤439 mJs/cm 2) completely inactivated FC, P.a. and S.a., while no further HPC inactivation was observed. FC, P.a. and S.a. did not exhibit regrowth after exposure to all the UV doses applied (up to 6 h storage). HPC did not exhibit regrowth after exposure to low UV doses (19-69 mJ/cm2), while it presented statistically significant regrowth in un-disinfected effluent and after exposure to higher UV doses (147-439 mJ/cm2).",
keywords = "Chlorination, Disinfection, Greywater, Microbial quality, Regrowth potential, UV disinfection",
author = "Eran Friedler and Anat Yardeni and Yael Gilboa and Yuval Alfiya",
year = "2011",
doi = "10.2166/wst.2011.272",
language = "אנגלית",
volume = "63",
pages = "931--940",
journal = "Water Science and Technology",
issn = "0273-1223",
publisher = "IWA Publishing",
number = "5",

}

Implementation of an ecosystem model for assessment of management policy based on sustainability criteria

Gilboa Y, Gal G, Parparov A, Friedler E. Implementation of an ecosystem model for assessment of management policy based on sustainability criteria. In MODSIM 2011 - 19th International Congress on Modelling and Simulation - Sustaining Our Future: Understanding and Living with Uncertainty. 2011. p. 2177-2183. (MODSIM 2011 - 19th International Congress on Modelling and Simulation - Sustaining Our Future: Understanding and Living with Uncertainty).
 

We implemented the 1-D lake ecosystem model DYRESM-CAEDYM (DYCD) to the subtropical meso-eutrophic Lake Kinneret, in order to determine an acceptable management policy based on sustainability criteria. The sustainability criteria were defined based on the Lake Kinneret system of water quality indices (WQI) and composite water quality index (CWQI) developed for the lake. The CWQI was evaluated by number of parameters that are monitored routinely at the lake and provide an overall picture of many of the ecosystem processes. Both the WQI and CWQI were applied in conjunction with output from 10 yr model scenarios, which included a wide range of nutrient loads and lake levels. In both cases, the scenarios covered a range wider than that historically observed in the lake. The scenarios included both simple cases of changes to one of the management forcing variables (e.g. lake level) and more complex cases that modified multiple forcing variables in tandem. We used the hydroecological model DYCD and ran it at WLs ranging between -209 to -218 m under varying nutrient loads, 0.56 to 56.6 gNm- 2y -1 and 0.039 to 3.9 gPm- 2y -1. For levels ranging between -209 to -213.4m simulation results allowed us to assess the direct relationships between nutrient loads and CWQI. The graphical solution of these relationships represents a "polygon" of permissible ranges and critical values of nutrient loads allowing conservation of the lake WQ at each WL. We used the combination of the model scenario results and the quantified WQ output to define a 3D (TN, TP and water level) space of acceptable management measures. The space defines the magnitude of management measures that can be performed on the lake ecosystem while sustaining the ecosystem. The results suggest a wider than expected range of management measures that can be used in the lake ecosystem, but the reaction of the ecosystem to the measures is not linear. As a result, reducing management measures does not always lead to improved sustainability. This approach is unique, and the first example of implementation of a management tool that integrates nutrient loads and WL through a WQ system. This approach could be implemented in other lakes around the world that suffer from deterioration in water quality as a result of changes in water level and nutrients loads. The application of a process based model, such as DYCD, has provided a means for examining the impact of external forcing on the lake ecosystem, beyond the observed historical conditions, and over extended periods of time. Our study demonstrates the major advantage associated with the use of process based ecosystem models as a tool for research and management.

@inproceedings{6fb43d677df8417b8aa52fa6834c029d,
title = "Implementation of an ecosystem model for assessment of management policy based on sustainability criteria",
abstract = "We implemented the 1-D lake ecosystem model DYRESM-CAEDYM (DYCD) to the subtropical meso-eutrophic Lake Kinneret, in order to determine an acceptable management policy based on sustainability criteria. The sustainability criteria were defined based on the Lake Kinneret system of water quality indices (WQI) and composite water quality index (CWQI) developed for the lake. The CWQI was evaluated by number of parameters that are monitored routinely at the lake and provide an overall picture of many of the ecosystem processes. Both the WQI and CWQI were applied in conjunction with output from 10 yr model scenarios, which included a wide range of nutrient loads and lake levels. In both cases, the scenarios covered a range wider than that historically observed in the lake. The scenarios included both simple cases of changes to one of the management forcing variables (e.g. lake level) and more complex cases that modified multiple forcing variables in tandem. We used the hydroecological model DYCD and ran it at WLs ranging between -209 to -218 m under varying nutrient loads, 0.56 to 56.6 gNm- 2y -1 and 0.039 to 3.9 gPm- 2y -1. For levels ranging between -209 to -213.4m simulation results allowed us to assess the direct relationships between nutrient loads and CWQI. The graphical solution of these relationships represents a {"}polygon{"} of permissible ranges and critical values of nutrient loads allowing conservation of the lake WQ at each WL. We used the combination of the model scenario results and the quantified WQ output to define a 3D (TN, TP and water level) space of acceptable management measures. The space defines the magnitude of management measures that can be performed on the lake ecosystem while sustaining the ecosystem. The results suggest a wider than expected range of management measures that can be used in the lake ecosystem, but the reaction of the ecosystem to the measures is not linear. As a result, reducing management measures does not always lead to improved sustainability. This approach is unique, and the first example of implementation of a management tool that integrates nutrient loads and WL through a WQ system. This approach could be implemented in other lakes around the world that suffer from deterioration in water quality as a result of changes in water level and nutrients loads. The application of a process based model, such as DYCD, has provided a means for examining the impact of external forcing on the lake ecosystem, beyond the observed historical conditions, and over extended periods of time. Our study demonstrates the major advantage associated with the use of process based ecosystem models as a tool for research and management.",
keywords = "CWQI, Nutrient load permissible range, Sustainability criteria, WQI, Water level, Water quality",
author = "Yael Gilboa and Gideon Gal and Arkadi Parparov and Eran Friedler",
year = "2011",
language = "אנגלית",
isbn = "9780987214317",
series = "MODSIM 2011 - 19th International Congress on Modelling and Simulation - Sustaining Our Future: Understanding and Living with Uncertainty",
pages = "2177--2183",
booktitle = "MODSIM 2011 - 19th International Congress on Modelling and Simulation - Sustaining Our Future",
note = "19th International Congress on Modelling and Simulation - Sustaining Our Future: Understanding and Living with Uncertainty, MODSIM2011 ; Conference date: 12-12-2011 Through 16-12-2011",

}

מידול עומסי נוטריאנטים וסדימנטים מאגן הכנרת באמצעות המודל AVGWLF

גלבוע י, גל ג, מרקל ד, רימר א, אוונס ב, פרידלר ע. מידול עומסי נוטריאנטים וסדימנטים מאגן הכנרת באמצעות המודל AVGWLF. חדשות הכנרת. 2011;32:15-20.
 
שילוב מודלים מספק חיזוי אמין של ספיקות ומזהמים באגן ההיקוות של הכנרת. כל הנתונים הללו יוכלו לספק מידע למדיניות הניהול של הכנרת. כולל מפה : איור 1 : אזור המחקר : תת אגן של הירדן הצפוני המתנקז לגשר הפקק.
@article{df9840d6d034439faf7ce08eda6a5617,
title = "מידול עומסי נוטריאנטים וסדימנטים מאגן הכנרת באמצעות המודל AVGWLF",
abstract = "שילוב מודלים מספק חיזוי אמין של ספיקות ומזהמים באגן ההיקוות של הכנרת. כל הנתונים הללו יוכלו לספק מידע למדיניות הניהול של הכנרת. כולל מפה : איור 1 : אזור המחקר : תת אגן של הירדן הצפוני המתנקז לגשר הפקק.",
author = "יעל גלבוע and גדעון גל and דורון מרקל and אלון רימר and בארי אוונס and ערן פרידלר",
year = "2011",
language = "עברית",
volume = "32",
pages = "15--20",
journal = "חדשות הכנרת",
issn = "0334-9268",

}

2010

Safe on-site reuse of greywater for irrigation - A critical review of current guidelines

Maimon A, Tal A, Friedler E, Gross A. Safe on-site reuse of greywater for irrigation - A critical review of current guidelines. Environmental Science and Technology. 2010 May 1;44(9):3213-3220. https://doi.org/10.1021/es902646g
 

Reuse of greywater for landscape irrigation can significantly reduce domestic water consumption. Alongside its benefits, there are potential drawbacks to greywater reuse, raising legitimate concerns about the impact on human and environmental health. In this review, a risk assessment framework is used to assess the adequacy of different regulations to ensure safe and long-lasting, onsite greywater reuse for irrigation. Existing regulations from around the world are assessed along with a standardized evaluation of measures taken to protect public and environmental health. In most cases, human health considerations currently dominate regulatory strategies, while environmental risks are either ignored or underrepresented. A distinction between single and multiple households was found to be a fundamental component of the regulations which often lead to approved utilization of untreated greywater among single households. We concluded that the use of untreated greywater is not recommended, especially in multihousehold systems as it may compromise public health, with single household systems posing more likely risks to the environment. Existing rules to control greywater use should be further revised toward the establishment of a more advanced regulatory system which can avert the salient potential risks associated with greywater reuse, while exploiting the enormous potential of this alternative water resource.

@article{cbedd60f94ec4be8a4ef2295b932b30d,
title = "Safe on-site reuse of greywater for irrigation - A critical review of current guidelines",
abstract = "Reuse of greywater for landscape irrigation can significantly reduce domestic water consumption. Alongside its benefits, there are potential drawbacks to greywater reuse, raising legitimate concerns about the impact on human and environmental health. In this review, a risk assessment framework is used to assess the adequacy of different regulations to ensure safe and long-lasting, onsite greywater reuse for irrigation. Existing regulations from around the world are assessed along with a standardized evaluation of measures taken to protect public and environmental health. In most cases, human health considerations currently dominate regulatory strategies, while environmental risks are either ignored or underrepresented. A distinction between single and multiple households was found to be a fundamental component of the regulations which often lead to approved utilization of untreated greywater among single households. We concluded that the use of untreated greywater is not recommended, especially in multihousehold systems as it may compromise public health, with single household systems posing more likely risks to the environment. Existing rules to control greywater use should be further revised toward the establishment of a more advanced regulatory system which can avert the salient potential risks associated with greywater reuse, while exploiting the enormous potential of this alternative water resource.",
author = "Adi Maimon and Alon Tal and Eran Friedler and Amit Gross",
year = "2010",
month = may,
day = "1",
doi = "10.1021/es902646g",
language = "אנגלית",
volume = "44",
pages = "3213--3220",
journal = "Environmental Science and Technology",
issn = "0013-936X",
publisher = "American Chemical Society",
number = "9",

}

Performance of UV disinfection and the microbial quality of greywater effluent along a reuse system for toilet flushing

Friedler E, Gilboa Y. Performance of UV disinfection and the microbial quality of greywater effluent along a reuse system for toilet flushing. Science of the Total Environment. 2010 Apr 1;408(9):2109-2117. https://doi.org/10.1016/j.scitotenv.2010.01.051
 

This paper examines the microbial quality of treated RBC (Rotating Biological Contactor) and MBR (Membrane Bioreactor) light greywater along a continuous pilot-scale reuse system for toilet flushing, quantifies the efficiency of UV disinfection unit, and evaluates the regrowth potential of selected microorganisms along the system. The UV disinfection unit was found to be very efficient in reducing faecal coliforms and Staphylococcus aureus. On the other hand, its efficiency of inactivation of HPC (Heterotrophic Plate Count) and Pseudomonas aeruginosa was lower. Some regrowth occurred in the reuse system as a result of HPC regrowth which included opportunistic pathogens such as P. aeruginosa. Although the membrane (UF) of the MBR system removed all bacteria from the greywater, bacteria were observed in the reuse system due to "hopping phenomenon." The microbial quality of the disinfected greywater was found to be equal or even better than the microbial quality of "clean" water in toilet bowls flushed with potable water (and used for excretion). Thus, the added health risk associated with reusing the UV-disinfected greywater for toilet flushing (regarding P. aeruginosa and S. aureus), was found to be insignificant. The UV disinfection unit totally removed (100%) the viral indicator (F-RNA phage, host: E. coli Famp+) injected to the treatment systems simulating transient viral contamination. To conclude, this work contributes to better design of UV disinfection reactors and provides an insight into the long-term behavior of selected microorganisms along on-site greywater reuse systems for toilet flushing.

@article{f1acc9dc692b45039c5269fbbc3697e6,
title = "Performance of UV disinfection and the microbial quality of greywater effluent along a reuse system for toilet flushing",
abstract = "This paper examines the microbial quality of treated RBC (Rotating Biological Contactor) and MBR (Membrane Bioreactor) light greywater along a continuous pilot-scale reuse system for toilet flushing, quantifies the efficiency of UV disinfection unit, and evaluates the regrowth potential of selected microorganisms along the system. The UV disinfection unit was found to be very efficient in reducing faecal coliforms and Staphylococcus aureus. On the other hand, its efficiency of inactivation of HPC (Heterotrophic Plate Count) and Pseudomonas aeruginosa was lower. Some regrowth occurred in the reuse system as a result of HPC regrowth which included opportunistic pathogens such as P. aeruginosa. Although the membrane (UF) of the MBR system removed all bacteria from the greywater, bacteria were observed in the reuse system due to {"}hopping phenomenon.{"} The microbial quality of the disinfected greywater was found to be equal or even better than the microbial quality of {"}clean{"} water in toilet bowls flushed with potable water (and used for excretion). Thus, the added health risk associated with reusing the UV-disinfected greywater for toilet flushing (regarding P. aeruginosa and S. aureus), was found to be insignificant. The UV disinfection unit totally removed (100%) the viral indicator (F-RNA phage, host: E. coli Famp+) injected to the treatment systems simulating transient viral contamination. To conclude, this work contributes to better design of UV disinfection reactors and provides an insight into the long-term behavior of selected microorganisms along on-site greywater reuse systems for toilet flushing.",
keywords = "Bacteria, F-RNA coliphage, Greywater reuse, Health risk, MBR, Microbial quality, RBC, UV disinfection",
author = "Eran Friedler and Yael Gilboa",
year = "2010",
month = apr,
day = "1",
doi = "10.1016/j.scitotenv.2010.01.051",
language = "אנגלית",
volume = "408",
pages = "2109--2117",
journal = "Science of the Total Environment",
issn = "0048-9697",
publisher = "Elsevier",
number = "9",

}

Factors affecting highway runoff quality

Opher T, Friedler E. Factors affecting highway runoff quality. Urban Water Journal. 2010;7(3):155-172. https://doi.org/10.1080/15730621003782339
 

Highway runoff often is a significant non-point pollution source. Though it has been extensively studied there are still open questions regarding the identity and mutual influences of the factors affecting pollutant concentrations in road runoff. This review starts with a description of the main pollutants (heavy metals, refractory organics and suspended matter), then it analyzes interactions existing between them and their fractionation between the particulate and dissolved phases. The third section examines the sources of pollution, being: vehicles which contribute fluid and solid pollutants, roads which contribute suspended solids, and dry and wet atmospheric deposition which is influenced by adjacent land-uses. The last section discusses the importance of the factors affecting road runoff quality, the main of which are traffic, rainfall, local conditions (climate and land use) and highway characteristics. The review reveals that conclusions derived from existing data are often ambiguous and significant knowledge gaps still exist.

@article{15dac1fb459b4dd192a60bab99651ee8,
title = "Factors affecting highway runoff quality",
abstract = "Highway runoff often is a significant non-point pollution source. Though it has been extensively studied there are still open questions regarding the identity and mutual influences of the factors affecting pollutant concentrations in road runoff. This review starts with a description of the main pollutants (heavy metals, refractory organics and suspended matter), then it analyzes interactions existing between them and their fractionation between the particulate and dissolved phases. The third section examines the sources of pollution, being: vehicles which contribute fluid and solid pollutants, roads which contribute suspended solids, and dry and wet atmospheric deposition which is influenced by adjacent land-uses. The last section discusses the importance of the factors affecting road runoff quality, the main of which are traffic, rainfall, local conditions (climate and land use) and highway characteristics. The review reveals that conclusions derived from existing data are often ambiguous and significant knowledge gaps still exist.",
keywords = "Antecedent dry period (ADP), Average annual daily traffic (AADT), First flush, Highway runoff, Washoff, Water quality",
author = "Tamar Opher and Eran Friedler",
year = "2010",
doi = "10.1080/15730621003782339",
language = "אנגלית",
volume = "7",
pages = "155--172",
journal = "Urban Water Journal",
issn = "1573-062X",
publisher = "Taylor and Francis Ltd.",
number = "3",

}

Physicochemical treatment of office and public buildings greywater

Friedler E, Alfiya Y. Physicochemical treatment of office and public buildings greywater. Water Science and Technology. 2010;62(10):2357-2363. https://doi.org/10.2166/wst.2010.499
 

The current study analyses the performance of deep sand filtration of greywater from an office building and the performance of a combined physicochemical process comprising of coagulation, sedimentation and filtration. Raw greywater quality exhibited very high variability with average turbidity of 35 NTU, and TSS, CODt, and BOD of 45, 240, 75 mg/l respectively. The stand-alone filter removed 50 and 70% of the turbidity and TSS, but failed to remove COD and BOD. Quality of the produced effluent was too low to allow any reuse. Clogging rate of the filter was high and under hydraulic loading of 3-4m3/(m2 h) the filtration cycle had to be terminated after 5-8 h. Clogging occurred mainly on the upper layer, indicating the dominance of "cake" filtration mechanism. Addition of coagulation and sedimentation prior to sedimentation dramatically improved effluent quality, reaching overall removal efficiencies of 92, 94, 65 and 57% of turbidity, TSS CODt and BOD respectively. The filtration cycle could be prolonged to 20 h. The effluent produced was of much better quality, yet, it has to be further treated (either biological treatment or membrane filtration). Most of the removal occurred in the coagulation-sedimentation step, while the filter acted as a polishing unit.

@article{58321c0f3aa9430db832ea4af5580d92,
title = "Physicochemical treatment of office and public buildings greywater",
abstract = "The current study analyses the performance of deep sand filtration of greywater from an office building and the performance of a combined physicochemical process comprising of coagulation, sedimentation and filtration. Raw greywater quality exhibited very high variability with average turbidity of 35 NTU, and TSS, CODt, and BOD of 45, 240, 75 mg/l respectively. The stand-alone filter removed 50 and 70% of the turbidity and TSS, but failed to remove COD and BOD. Quality of the produced effluent was too low to allow any reuse. Clogging rate of the filter was high and under hydraulic loading of 3-4m3/(m2 h) the filtration cycle had to be terminated after 5-8 h. Clogging occurred mainly on the upper layer, indicating the dominance of {"}cake{"} filtration mechanism. Addition of coagulation and sedimentation prior to sedimentation dramatically improved effluent quality, reaching overall removal efficiencies of 92, 94, 65 and 57% of turbidity, TSS CODt and BOD respectively. The filtration cycle could be prolonged to 20 h. The effluent produced was of much better quality, yet, it has to be further treated (either biological treatment or membrane filtration). Most of the removal occurred in the coagulation-sedimentation step, while the filter acted as a polishing unit.",
keywords = "Greywater, Offices, On-site reuse, Physicochemical treatment",
author = "Eran Friedler and Yuval Alfiya",
year = "2010",
doi = "10.2166/wst.2010.499",
language = "אנגלית",
volume = "62",
pages = "2357--2363",
journal = "Water Science and Technology",
issn = "0273-1223",
publisher = "IWA Publishing",
number = "10",

}

2009

Adapting empirical equations to Lake Kinneret data by using three calibration methods

Gilboa Y, Friedler E, Gal G. Adapting empirical equations to Lake Kinneret data by using three calibration methods. Ecological Modelling. 2009 Dec 10;220(23):3291-3300. https://doi.org/10.1016/j.ecolmodel.2009.09.007
 

This paper examines whether the relationships between a number of characteristic limnological variables (suspended particulate matter, turbidity, Secchi depth, light attenuation, and chlorophyll a) determined for temperate lakes are consistent with the relationships found in Mediterranean lakes such as Lake Kinneret. We found that the use of published relationships between lake variables may lead to erroneous results when applied indiscriminately to other lake types. We applied linear regression, nonlinear regression and genetic algorithm (GA) approaches in order to fit the relationships to Lake Kinneret data. We showed that linear equations, simple or multivariate that do not require transformation prior to calibration, can be calibrated by simple and quick methods such as linear regression. However, when linear transformation is required prior to calibration the GA calibration produced better results. In addition, we found that the nonlinear regression method yielded a weak prediction, while the GA led to more accurate results. A sensitivity analysis of the GA operators' values indicated that using a crossover probability of 80% produced the best prediction. Furthermore, since the GA sometimes converges to local optimum, it must operate for a number of runs. We found that in our case 20 GA runs provided the most robust results.

@article{96c139521a10458e9bbe84a9ea8c17de,
title = "Adapting empirical equations to Lake Kinneret data by using three calibration methods",
abstract = "This paper examines whether the relationships between a number of characteristic limnological variables (suspended particulate matter, turbidity, Secchi depth, light attenuation, and chlorophyll a) determined for temperate lakes are consistent with the relationships found in Mediterranean lakes such as Lake Kinneret. We found that the use of published relationships between lake variables may lead to erroneous results when applied indiscriminately to other lake types. We applied linear regression, nonlinear regression and genetic algorithm (GA) approaches in order to fit the relationships to Lake Kinneret data. We showed that linear equations, simple or multivariate that do not require transformation prior to calibration, can be calibrated by simple and quick methods such as linear regression. However, when linear transformation is required prior to calibration the GA calibration produced better results. In addition, we found that the nonlinear regression method yielded a weak prediction, while the GA led to more accurate results. A sensitivity analysis of the GA operators' values indicated that using a crossover probability of 80% produced the best prediction. Furthermore, since the GA sometimes converges to local optimum, it must operate for a number of runs. We found that in our case 20 GA runs provided the most robust results.",
keywords = "Calibration, Empirical equations, Genetic algorithms, Lake Kinneret, Linear regression, Nonlinear regression",
author = "Yael Gilboa and Eran Friedler and Gideon Gal",
note = "Funding Information: We thank the Kinneret Limnological Laboratory (KLL) for making data from its Lake Kinneret database available for this study. Specifically, we thank KLL's field crew for collecting the samples and Secchi depth data, Y.Z. Yacobi for the chlorophyll a, and light attenuation data, and the Mekorot Water company for conducting the turbidity and SPM analyses. This research was supported by grants from the Ministry of Science and Technology Israel, and the Federal Ministry of Education and Research, Germany (BMBF).",
year = "2009",
month = dec,
day = "10",
doi = "10.1016/j.ecolmodel.2009.09.007",
language = "אנגלית",
volume = "220",
pages = "3291--3300",
journal = "Ecological Modelling",
issn = "0304-3800",
publisher = "Elsevier",
number = "23",

}

Analysis of the long-term performance of an on-site greywater treatment plant using novel statistical approaches

Aizenchtadt E, Ingman D, Friedler E. Analysis of the long-term performance of an on-site greywater treatment plant using novel statistical approaches. Urban Water Journal. 2009 Oct;6(5):341-354. https://doi.org/10.1080/15730620902795210
 

This paper analyses the performance of three greywater treatment systems: RBC, MBR and stand-alone sand filter. Pollutants' concentrations in raw greywater exhibited a long-term increase. The RBC and MBR exhibited high removal efficiency, while the sand filter performance was much poorer. In order to apply control measures, dynamic regression SPC (DRSPC), SPC (statistical process control) with variable control limits, was developed. DRSPC often better described underlying long-term trends. For RBC effluent, DRSPC had the highest advantage for TKN. For MBR effluent, it had the highest advantage for turbidity and CODt. For the stand-alone sand filter effluent, the DRSPC advantage was much lower. Constant density curves showed low negative correlation between inflow and outflow VSS, and no correlation between inflow and outflow BODt for the RBC. For the MBR, no slope was identified for VSS and low negative slope for BODt. The BODt of the sand filter effluent revealed positive correlation with inflow.

@article{bfc5c0e170bd4b24941fe2be0e4dd30f,
title = "Analysis of the long-term performance of an on-site greywater treatment plant using novel statistical approaches",
abstract = "This paper analyses the performance of three greywater treatment systems: RBC, MBR and stand-alone sand filter. Pollutants' concentrations in raw greywater exhibited a long-term increase. The RBC and MBR exhibited high removal efficiency, while the sand filter performance was much poorer. In order to apply control measures, dynamic regression SPC (DRSPC), SPC (statistical process control) with variable control limits, was developed. DRSPC often better described underlying long-term trends. For RBC effluent, DRSPC had the highest advantage for TKN. For MBR effluent, it had the highest advantage for turbidity and CODt. For the stand-alone sand filter effluent, the DRSPC advantage was much lower. Constant density curves showed low negative correlation between inflow and outflow VSS, and no correlation between inflow and outflow BODt for the RBC. For the MBR, no slope was identified for VSS and low negative slope for BODt. The BODt of the sand filter effluent revealed positive correlation with inflow.",
keywords = "Greywater treatment, MBR, Process control, RBC, SPC, Sand filtration",
author = "Elena Aizenchtadt and Dov Ingman and Eran Friedler",
note = "Funding Information: This research was partially supported by The Israeli Water and Wastewater Authority and by The Grand Water Research Institute, Technion.",
year = "2009",
month = oct,
doi = "10.1080/15730620902795210",
language = "אנגלית",
volume = "6",
pages = "341--354",
journal = "Urban Water Journal",
issn = "1573-062X",
publisher = "Taylor and Francis Ltd.",
number = "5",

}

A preliminary coupled MT-GA model for the prediction of highway runoff quality

Opher T, Friedler E. A preliminary coupled MT-GA model for the prediction of highway runoff quality. Science of the Total Environment. 2009 Jul 15;407(15):4490-4496. https://doi.org/10.1016/j.scitotenv.2009.04.043
 

Pollutants accumulated on road pavement during dry periods are washed off the surface with runoff water during rainfall events, presenting a potentially hazardous non-point source of pollution. Estimation of pollutant loads in these runoff waters is required for developing mitigation and management strategies, yet the numerous factors involved and their complex interconnected influences make straightforward assessment impossible. Data-driven models (DDMs) have lately been used in water and environmental research and have shown very good prediction ability. The proposed methodology of a coupled MT-GA (model tree-genetic algorithm) model provides an effective, accurate and easily calibrated predictive model for EMC (event mean concentration) of highway runoff pollutants. The models were trained and verified using a comprehensive data set of runoff events monitored in various highways in California, USA. EMCs of Cr, Pb, Zn, TOC and TSS were modeled, using different combinations of explanatory variables. The models' prediction ability in terms of correlation between predicted and actual values of both training and verification data was mostly higher than previously reported values. Sensitivity analysis was performed to examine the relative significance of each explanatory variable and the models' response to changes in input values.

@article{343b3df70a034307af286d5fbb00b2d1,
title = "A preliminary coupled MT-GA model for the prediction of highway runoff quality",
abstract = "Pollutants accumulated on road pavement during dry periods are washed off the surface with runoff water during rainfall events, presenting a potentially hazardous non-point source of pollution. Estimation of pollutant loads in these runoff waters is required for developing mitigation and management strategies, yet the numerous factors involved and their complex interconnected influences make straightforward assessment impossible. Data-driven models (DDMs) have lately been used in water and environmental research and have shown very good prediction ability. The proposed methodology of a coupled MT-GA (model tree-genetic algorithm) model provides an effective, accurate and easily calibrated predictive model for EMC (event mean concentration) of highway runoff pollutants. The models were trained and verified using a comprehensive data set of runoff events monitored in various highways in California, USA. EMCs of Cr, Pb, Zn, TOC and TSS were modeled, using different combinations of explanatory variables. The models' prediction ability in terms of correlation between predicted and actual values of both training and verification data was mostly higher than previously reported values. Sensitivity analysis was performed to examine the relative significance of each explanatory variable and the models' response to changes in input values.",
keywords = "Data-driven model (DDM), Event mean concentration (EMC), Genetic algorithm (GA), Highway runoff, Model tree (MT)",
author = "Tamar Opher and Eran Friedler",
note = "Funding Information: This research was funded by the Grand Water Research Institute (GWRI). ",
year = "2009",
month = jul,
day = "15",
doi = "10.1016/j.scitotenv.2009.04.043",
language = "אנגלית",
volume = "407",
pages = "4490--4496",
journal = "Science of the Total Environment",
issn = "0048-9697",
publisher = "Elsevier",
number = "15",

}

Spatial distribution of major microbial groups in a well established constructed wetland treating municipal wastewater

Krasnits E, Friedler E, Sabbah I, Beliavski M, Tarre S, Green M. Spatial distribution of major microbial groups in a well established constructed wetland treating municipal wastewater. Ecological Engineering. 2009 Jul;35(7):1085-1089. https://doi.org/10.1016/j.ecoleng.2009.03.020
 

This paper characterizes the spatial distribution of major microbial populations in a well established subsurface horizontal flow constructed wetland (CWL) that has been in operation for 7 years. The CWL receives partially treated municipal wastewater with an average COD and TSS of 430 and 130 mg L-1, respectively. Results from the seventh year of operation at a loading rate of 11 g-BOD m-2 d-1 show 60% and 70% COD and BOD reduction, respectively. Low oxygen concentrations, typical to subsurface horizontal CWLs, resulted in almost no nitrification. Major microbial groups were characterized by fluorescent in situ hybridization (FISH) at the beginning, center and end of the CWL and at different depths including the root zone. Relatively uniform microbial population distribution was observed, with some evidence for oxygen translocation by plants to the root zone at areas closer to the CWL outlet. Further, depth was found to have a somewhat higher effect on the distribution of the major microbial groups than distance from the inlet. Eubacteria dominated the microbial population at all points consisting almost always more than 85% of the population. About 50% of the Archaea present in the CWL were methane producers. Sulfate-reducing bacteria were observed in significant numbers with low vertical and longitudinal variations. Nitrifying bacteria were present only sparsely (1-3%), while methanotrophic bacteria were found in higher numbers (∼10% of the population).

@article{158ce94d8701404788f27cff49f07a71,
title = "Spatial distribution of major microbial groups in a well established constructed wetland treating municipal wastewater",
abstract = "This paper characterizes the spatial distribution of major microbial populations in a well established subsurface horizontal flow constructed wetland (CWL) that has been in operation for 7 years. The CWL receives partially treated municipal wastewater with an average COD and TSS of 430 and 130 mg L-1, respectively. Results from the seventh year of operation at a loading rate of 11 g-BOD m-2 d-1 show 60% and 70% COD and BOD reduction, respectively. Low oxygen concentrations, typical to subsurface horizontal CWLs, resulted in almost no nitrification. Major microbial groups were characterized by fluorescent in situ hybridization (FISH) at the beginning, center and end of the CWL and at different depths including the root zone. Relatively uniform microbial population distribution was observed, with some evidence for oxygen translocation by plants to the root zone at areas closer to the CWL outlet. Further, depth was found to have a somewhat higher effect on the distribution of the major microbial groups than distance from the inlet. Eubacteria dominated the microbial population at all points consisting almost always more than 85% of the population. About 50% of the Archaea present in the CWL were methane producers. Sulfate-reducing bacteria were observed in significant numbers with low vertical and longitudinal variations. Nitrifying bacteria were present only sparsely (1-3%), while methanotrophic bacteria were found in higher numbers (∼10% of the population).",
keywords = "Constructed wetland microbial populations, FISH, Horizontal flow constructed wetland, Municipal wastewater, Spatial distribution, Subsurface flow constructed wetland",
author = "E. Krasnits and E. Friedler and I. Sabbah and M. Beliavski and S. Tarre and M. Green",
note = "Funding Information: The research was financed by the JNF.",
year = "2009",
month = jul,
doi = "10.1016/j.ecoleng.2009.03.020",
language = "אנגלית",
volume = "35",
pages = "1085--1089",
journal = "Ecological Engineering",
issn = "0925-8574",
publisher = "Elsevier",
number = "7",

}

Development of a data driven model for estimating pollutant levels in highway stormwater runoff

Opher T, Friedler E. Development of a data driven model for estimating pollutant levels in highway stormwater runoff. VDM Verlag Dr. Muller, 2009. 144 p.
@book{a736bf9374954563ab39f45d7d1abea2,
title = "Development of a data driven model for estimating pollutant levels in highway stormwater runoff",
keywords = "runoff, road runoff, Stormwater, runoff pollution, stormwater pollution, transportation, traffic",
author = "Tamar Opher and Eran Friedler",
year = "2009",
language = "American English",
isbn = "9783639150346",
publisher = "VDM Verlag Dr. Muller",

}

Modeling highway runoff pollutant levels using a data driven model

Opher T, Ostfeld A, Friedler E. Modeling highway runoff pollutant levels using a data driven model. Water Science and Technology. 2009;60(1):19-28. https://doi.org/10.2166/wst.2009.289
 

Pollutants accumulated on road pavement during dry periods are washed off the surface with runoff water during rainfall events, presenting a potentially hazardous non-point source of pollution. Estimation of pollutant loads in these runoff waters is required for developing mitigation and management strategies, yet the numerous factors involved and their complex interconnected influences make straightforward assessment almost impossible. Data driven models (DDMs) have lately been used in water and environmental research and have shown very good prediction ability. The proposed methodology of a coupled MT-GA model provides an effective, accurate and easily calibrated predictive model for EMC of highway runoff pollutants. The models were trained and verified using a comprehensive data set of runoff events monitored in various highways in California, USA. EMCs of Cr, Pb, Zn, TOC and TSS were modeled, using different combinations of explanatory variables. The models' prediction ability in terms of correlation between predicted and actual values of both training and verification data was mostly higher than previously reported values. Pb Total was modeled with an outcome of R2 of 0.95 on training data and 0.43 on verification data. The developed model for TOC achieved R2 values of 0.91 and 0.49 on training and verification data respectively.

@article{7fbab3af074b42ca8f83e7a0f1942c6a,
title = "Modeling highway runoff pollutant levels using a data driven model",
abstract = "Pollutants accumulated on road pavement during dry periods are washed off the surface with runoff water during rainfall events, presenting a potentially hazardous non-point source of pollution. Estimation of pollutant loads in these runoff waters is required for developing mitigation and management strategies, yet the numerous factors involved and their complex interconnected influences make straightforward assessment almost impossible. Data driven models (DDMs) have lately been used in water and environmental research and have shown very good prediction ability. The proposed methodology of a coupled MT-GA model provides an effective, accurate and easily calibrated predictive model for EMC of highway runoff pollutants. The models were trained and verified using a comprehensive data set of runoff events monitored in various highways in California, USA. EMCs of Cr, Pb, Zn, TOC and TSS were modeled, using different combinations of explanatory variables. The models' prediction ability in terms of correlation between predicted and actual values of both training and verification data was mostly higher than previously reported values. Pb Total was modeled with an outcome of R2 of 0.95 on training data and 0.43 on verification data. The developed model for TOC achieved R2 values of 0.91 and 0.49 on training and verification data respectively.",
keywords = "Data driven model (DDM), Event mean concentration (EMC), Genetic algorithm (GA), Highway runoff, Model tree (MT)",
author = "T. Opher and A. Ostfeld and E. Friedler",
year = "2009",
doi = "10.2166/wst.2009.289",
language = "אנגלית",
volume = "60",
pages = "19--28",
journal = "Water Science and Technology",
issn = "0273-1223",
publisher = "IWA Publishing",
number = "1",

}

2008

Quality control of wastewater treatment: A new approach

Aizenchtadt E, Ingman D, Friedler E. Quality control of wastewater treatment: A new approach. European Journal of Operational Research. 2008 Sep 1;189(2):445-458. https://doi.org/10.1016/j.ejor.2007.06.001
 

This paper presents a new approach to quality control of wastewater treatment. The first part formulates basic principles of statistical process control (SPC) and Taguchi Method. Then it is shown that the classical SPC technique used in industry, cannot be to applied to wastewater treatment plants without adaptation and that the Taguchi Method is inapplicable in this case. This is followed by an example from literature, which demonstrates the problems of applying the SPC method to wastewater treatment. The third part of the paper presents a case study where the performance of a greywater treatment plant is examined. The performance is analyzed by means of cross-correlation between input and output parameters. A new approach to SPC of wastewater treatment, either "Dynamic SPC" or "linear regression SPC", is presented, and a permeability coefficient is developed (the ratio of the output and input energies). Both are proposed as monitoring tools for wastewater treatment systems.

@article{af361969de374a5a81079a630b1f16a9,
title = "Quality control of wastewater treatment: A new approach",
abstract = "This paper presents a new approach to quality control of wastewater treatment. The first part formulates basic principles of statistical process control (SPC) and Taguchi Method. Then it is shown that the classical SPC technique used in industry, cannot be to applied to wastewater treatment plants without adaptation and that the Taguchi Method is inapplicable in this case. This is followed by an example from literature, which demonstrates the problems of applying the SPC method to wastewater treatment. The third part of the paper presents a case study where the performance of a greywater treatment plant is examined. The performance is analyzed by means of cross-correlation between input and output parameters. A new approach to SPC of wastewater treatment, either {"}Dynamic SPC{"} or {"}linear regression SPC{"}, is presented, and a permeability coefficient is developed (the ratio of the output and input energies). Both are proposed as monitoring tools for wastewater treatment systems.",
keywords = "Cross-correlation, Dynamic SPC, Energy flux, Environment, Quality control, Wastewater treatment",
author = "Elena Aizenchtadt and Dov Ingman and Eran Friedler",
year = "2008",
month = sep,
day = "1",
doi = "10.1016/j.ejor.2007.06.001",
language = "אנגלית",
volume = "189",
pages = "445--458",
journal = "European Journal of Operational Research",
issn = "0377-2217",
publisher = "Elsevier",
number = "2",

}

Control of sulfide in sewer systems by dosage of iron salts: Comparison between theoretical and experimental results, and practical implications

Firer D, Friedler E, Lahav O. Control of sulfide in sewer systems by dosage of iron salts: Comparison between theoretical and experimental results, and practical implications. Science of the Total Environment. 2008 Mar 15;392(1):145-156. https://doi.org/10.1016/j.scitotenv.2007.11.008
 

Removal of sulfide species from municipal sewage conveyance systems by dosage of iron salts is a relatively common practice. However, the reactions that occur between dissolved iron and sulfide species in municipal sewage media have not yet been fully quantified, and practical application relies heavily on empirical experience, which is often site specific. The aim of this work was to combine theoretical considerations and empirical observations to enable a more reliable prediction of the sulfide removal efficiency for a given dosing strategy. Two main questions were addressed, regarding the dominant sulfur species that results from the oxidation of sulfide by Fe(III) and the dominant precipitation reaction between Fe(II) and sulfide species. Comparison of thermodynamic prediction obtained by an equilibrium chemistry-based computer program (MINEQL+) with experimental results obtained by dosing ferrous salts showed that the product of precipitation is FeS under all operational conditions tested. Regarding the reaction between ferric salts and sulfide species, analysis of thermodynamic data suggested that the dominant product of sulfide oxidation under typical pe/pH conditions prevailing in municipal raw wastewater is SO42-. However, comparison between sulfide removal in laboratory experiments conducted with multiple samples of raw municipal sewage with a varying composition, and the prediction of MINEQL+ showed the main sulfide oxidation product to be S0. In order to reduce sulfide in sewage to < 0.1 mgS/l a minimal molar ratio of around 1.3 Fe to 1 S should be applied when ferrous salts are used, as compared with a minimal ratio of 0.9 Fe to 1 S required when ferric salts or a mixture of ferrous and ferric salts (at a 2 Fe(III) to 1 Fe(II) ratio) are used. It appears that the high Fe to S(-II) ratios often recommended in practice can be reduced considerably by applying tight in-line control.

@article{43fa2e2e1004425e92cf0c9b9c3fdf4a,
title = "Control of sulfide in sewer systems by dosage of iron salts: Comparison between theoretical and experimental results, and practical implications",
abstract = "Removal of sulfide species from municipal sewage conveyance systems by dosage of iron salts is a relatively common practice. However, the reactions that occur between dissolved iron and sulfide species in municipal sewage media have not yet been fully quantified, and practical application relies heavily on empirical experience, which is often site specific. The aim of this work was to combine theoretical considerations and empirical observations to enable a more reliable prediction of the sulfide removal efficiency for a given dosing strategy. Two main questions were addressed, regarding the dominant sulfur species that results from the oxidation of sulfide by Fe(III) and the dominant precipitation reaction between Fe(II) and sulfide species. Comparison of thermodynamic prediction obtained by an equilibrium chemistry-based computer program (MINEQL+) with experimental results obtained by dosing ferrous salts showed that the product of precipitation is FeS under all operational conditions tested. Regarding the reaction between ferric salts and sulfide species, analysis of thermodynamic data suggested that the dominant product of sulfide oxidation under typical pe/pH conditions prevailing in municipal raw wastewater is SO42-. However, comparison between sulfide removal in laboratory experiments conducted with multiple samples of raw municipal sewage with a varying composition, and the prediction of MINEQL+ showed the main sulfide oxidation product to be S0. In order to reduce sulfide in sewage to < 0.1 mgS/l a minimal molar ratio of around 1.3 Fe to 1 S should be applied when ferrous salts are used, as compared with a minimal ratio of 0.9 Fe to 1 S required when ferric salts or a mixture of ferrous and ferric salts (at a 2 Fe(III) to 1 Fe(II) ratio) are used. It appears that the high Fe to S(-II) ratios often recommended in practice can be reduced considerably by applying tight in-line control.",
keywords = "Dosing strategy, Ferric iron, Ferrous iron, Sulfide removal, Wastewater",
author = "Dan Firer and Eran Friedler and Ori Lahav",
note = "Funding Information: The financial support of The Grand Water Research Institute, Technion and The Pinhas Sapir Fund for Applied Research in the Municipal Government (Pais – Israel National Lottery) is greatly acknowledged.",
year = "2008",
month = mar,
day = "15",
doi = "10.1016/j.scitotenv.2007.11.008",
language = "אנגלית",
volume = "392",
pages = "145--156",
journal = "Science of the Total Environment",
issn = "0048-9697",
publisher = "Elsevier",
number = "1",

}

Chlorination and coagulation as pretreatments for greywater desalination

Friedler E, Katz I, Dosoretz CG. Chlorination and coagulation as pretreatments for greywater desalination. Desalination. 2008 Mar 1;222(1-3):38-49. https://doi.org/10.1016/j.desal.2007.01.130
 

On-site greywater reclamation is thought to enhance water usage efficiency and decrease urban water demand. Direct membrane filtration is an attractive approach for treatment of greywater in residential areas due to its small footprint and high reliability, as product quality is insensitive to fluctuations in inflow quality. The research evaluated coagulation or chlorination as possible pretreatments for ultrafiltration followed by RO desalination. The system was fed with "light" greywater (avg. TOC, TN and P - 24.9, 4.6 and 0.7 mg L -1; turbidity - 34 NTU). Direct filtration, without pretreatment, resulted in sharp decrease of the UF permeability, due to organic fouling and biofouling. The RO membrane was suspected for phosphate salt scaling. To overcome these drawbacks, coagulation and chlorination were evaluated as pretreatment options prior to UF. Chlorine demand of the greywater was 10-20 mg L -1. Applying this dose and controlling residual chlorine in the UF feed, lowered the fouling rate by 33%. Mass balances calculations indicated that chlorination inhibited microbial activity in the UF system. The partial oxidation of the organic matter, achieved by the chlorination pretreatment, may have changed the properties of the organic matter and thus its reactivity with the UF and RO membranes. Next, ferric chloride was tested as a coagulant. Dosing 50 mg L -1 ferric chloride reduced the UF flux decline rate by 43%, mainly due to a 38% decrease of the organic load. After coagulation, larger particles with narrower size distribution were observed in the feed (average size ~0.5 μm). This upward shift resulted in a more porous filtration cake buildup on the UF membrane, a finding which supports the enhanced performance. Although a positive synergistic effect could be anticipated, the combined coagulation-chlorination process increased fouling rate in the RO membrane probably due to the increase in the concentration polarization phenomenon, as a result of a rise in the concentrations of counter ions associated with the pretreatment reactants and possible surplus of the latter. The results indicate that greywater pretreatment is a prerequisite to hamper UF membrane biofouling. Coagulation was found to be superior to chlorination for the UF. Effluents produced by each of the membranal steps were of excellent quality that can be used for various purposes, being low in organic content, suspended matter and colloids (UF), or desalinated (RO).

@article{7f03b28eaca34a6fa8bc031d0e834dbe,
title = "Chlorination and coagulation as pretreatments for greywater desalination",
abstract = "On-site greywater reclamation is thought to enhance water usage efficiency and decrease urban water demand. Direct membrane filtration is an attractive approach for treatment of greywater in residential areas due to its small footprint and high reliability, as product quality is insensitive to fluctuations in inflow quality. The research evaluated coagulation or chlorination as possible pretreatments for ultrafiltration followed by RO desalination. The system was fed with {"}light{"} greywater (avg. TOC, TN and P - 24.9, 4.6 and 0.7 mg L -1; turbidity - 34 NTU). Direct filtration, without pretreatment, resulted in sharp decrease of the UF permeability, due to organic fouling and biofouling. The RO membrane was suspected for phosphate salt scaling. To overcome these drawbacks, coagulation and chlorination were evaluated as pretreatment options prior to UF. Chlorine demand of the greywater was 10-20 mg L -1. Applying this dose and controlling residual chlorine in the UF feed, lowered the fouling rate by 33%. Mass balances calculations indicated that chlorination inhibited microbial activity in the UF system. The partial oxidation of the organic matter, achieved by the chlorination pretreatment, may have changed the properties of the organic matter and thus its reactivity with the UF and RO membranes. Next, ferric chloride was tested as a coagulant. Dosing 50 mg L -1 ferric chloride reduced the UF flux decline rate by 43%, mainly due to a 38% decrease of the organic load. After coagulation, larger particles with narrower size distribution were observed in the feed (average size ~0.5 μm). This upward shift resulted in a more porous filtration cake buildup on the UF membrane, a finding which supports the enhanced performance. Although a positive synergistic effect could be anticipated, the combined coagulation-chlorination process increased fouling rate in the RO membrane probably due to the increase in the concentration polarization phenomenon, as a result of a rise in the concentrations of counter ions associated with the pretreatment reactants and possible surplus of the latter. The results indicate that greywater pretreatment is a prerequisite to hamper UF membrane biofouling. Coagulation was found to be superior to chlorination for the UF. Effluents produced by each of the membranal steps were of excellent quality that can be used for various purposes, being low in organic content, suspended matter and colloids (UF), or desalinated (RO).",
keywords = "Chlorination, Coagulation, Desalination, Direct membrane filtration, Greywater, Pretreatment, RO, UF",
author = "Eran Friedler and Ilan Katz and Dosoretz, {Carlos G.}",
note = "Funding Information: The financial support of the Grand Water Research Institute (Technion) is greatly appreciated.",
year = "2008",
month = mar,
day = "1",
doi = "10.1016/j.desal.2007.01.130",
language = "אנגלית",
volume = "222",
pages = "38--49",
journal = "Desalination",
issn = "0011-9164",
publisher = "Elsevier",
number = "1-3",

}

The water saving potential and the socio-economic feasibility of greywater reuse within the urban sector - Israel as a case study

Friedler E. The water saving potential and the socio-economic feasibility of greywater reuse within the urban sector - Israel as a case study. International Journal of Environmental Studies. 2008 Feb;65(1):57-69. https://doi.org/10.1080/00207230701846697
 

This paper demonstrates that on-site greywater reuse is acceptable to the Israeli public and is an economically feasible solution for reducing urban water demand. The penetration ratio of greywater reuse in Israel was estimated at 19-31% in 2025 (population ∼10 × 106), which is equivalent to a water saving of 30-51 × 106 m3/y. The public was found to highly support the six reuse options suggested, with an overall average grade of 85%. Nevertheless, people supported public reuse more than reuse in their homes. The economic analysis showed that on-site greywater reuse can be economically feasible especially where water prices continually increase. Under the current Israeli water and sewage tariffs an RBC-based reuse system became economically feasible when building size reached seven storeys (26 flats). The unit cost of greywater was found to be very sensitive to the system's size especially in the small size range.

@article{f2c649d78a364849a3099a634ef22e53,
title = "The water saving potential and the socio-economic feasibility of greywater reuse within the urban sector - Israel as a case study",
abstract = "This paper demonstrates that on-site greywater reuse is acceptable to the Israeli public and is an economically feasible solution for reducing urban water demand. The penetration ratio of greywater reuse in Israel was estimated at 19-31% in 2025 (population ∼10 × 106), which is equivalent to a water saving of 30-51 × 106 m3/y. The public was found to highly support the six reuse options suggested, with an overall average grade of 85%. Nevertheless, people supported public reuse more than reuse in their homes. The economic analysis showed that on-site greywater reuse can be economically feasible especially where water prices continually increase. Under the current Israeli water and sewage tariffs an RBC-based reuse system became economically feasible when building size reached seven storeys (26 flats). The unit cost of greywater was found to be very sensitive to the system's size especially in the small size range.",
keywords = "Economic aspects, Greywater reuse, On-site treatment, Public acceptance, Urban, Water saving potential",
author = "E. Friedler",
note = "Funding Information: The financial support of the Israeli Water Authority and The Grand Water Research Institute, Technion is greatly appreciated. The author further wishes to thank the people who agreed to participate in the survey, and the manufacturers and distributors (local and international) who courteously supplied information on the capital and O&M costs of various components of the treatment and reuse system.",
year = "2008",
month = feb,
doi = "10.1080/00207230701846697",
language = "אנגלית",
volume = "65",
pages = "57--69",
journal = "International Journal of Environmental Studies",
issn = "0020-7233",
publisher = "Taylor and Francis Ltd.",
number = "1",

}

UV disinfection of RBC-treated light greywater effluent: Kinetics, survival and regrowth of selected microorganisms

Gilboa Y, Friedler E. UV disinfection of RBC-treated light greywater effluent: Kinetics, survival and regrowth of selected microorganisms. Water Research. 2008 Feb;42(4-5):1043-1050. https://doi.org/10.1016/j.watres.2007.09.027
 

The microbial quality of raw greywater was found to be much better than that of municipal wastewater, with 1.6×107 cfu ml-1 heterotrophic plate count (HPC), and 3.8×104, 9.9×103, 3.3×103 and 4.6×100 cfu 100 ml-1 faecal coliforms (FC), Staphylococcus aureus sp., Pseudomonas aeruginosa sp. and Clostridium perfringes sp., respectively. Further, three viral indicators monitored (somatic phage, host: Escherichia coli CN13 and F-RNA phages, hosts: E. coli F+amp, E. coli K12) were not present in raw greywater. The greywater was treated by an RBC followed by sedimentation. The treatment removed two orders of magnitude of all bacteria. UV disinfection kinetics, survival and regrowth of HPC, FC, P. aeruginosa sp. and S. aureus sp. were examined. At doses up to 69 mW s cm-2 FC were found to be the most resistant bacteria, followed by HPC, P. aeruginosa sp. and S. aureus sp. (inactivation rate coefficients: 0.0687, 0.113, 0.129 and 0.201 cm2 mW-1 s-1, respectively). At higher doses (69-439 mW s cm-2) all but HPC (which exhibited a tailing curve) were completely eliminated. Microscopic examination showed that FC self-aggregate in the greywater effluent. This provides FC an advantage at low doses, since the concentration of suspended matter (that can provide shelter from UV radiation) in the effluent was very low. FC, P. aeruginosa sp. and S. aureus sp. did not exhibit regrowth up to 6 h after exposure to increasing UV doses (19-439 mW s cm-2). HPC regrowth was proven to be statistically significant in un-disinfected effluent and after irradiation with high UV doses (147 and 439 mW s cm-2). At these doses regrowth resulted from growth of UV-resistant bacteria due to decreased competition with other bacteria eliminated by the irradiation.

@article{e244f996546c43378f75ea02c8ead331,
title = "UV disinfection of RBC-treated light greywater effluent: Kinetics, survival and regrowth of selected microorganisms",
abstract = "The microbial quality of raw greywater was found to be much better than that of municipal wastewater, with 1.6×107 cfu ml-1 heterotrophic plate count (HPC), and 3.8×104, 9.9×103, 3.3×103 and 4.6×100 cfu 100 ml-1 faecal coliforms (FC), Staphylococcus aureus sp., Pseudomonas aeruginosa sp. and Clostridium perfringes sp., respectively. Further, three viral indicators monitored (somatic phage, host: Escherichia coli CN13 and F-RNA phages, hosts: E. coli F+amp, E. coli K12) were not present in raw greywater. The greywater was treated by an RBC followed by sedimentation. The treatment removed two orders of magnitude of all bacteria. UV disinfection kinetics, survival and regrowth of HPC, FC, P. aeruginosa sp. and S. aureus sp. were examined. At doses up to 69 mW s cm-2 FC were found to be the most resistant bacteria, followed by HPC, P. aeruginosa sp. and S. aureus sp. (inactivation rate coefficients: 0.0687, 0.113, 0.129 and 0.201 cm2 mW-1 s-1, respectively). At higher doses (69-439 mW s cm-2) all but HPC (which exhibited a tailing curve) were completely eliminated. Microscopic examination showed that FC self-aggregate in the greywater effluent. This provides FC an advantage at low doses, since the concentration of suspended matter (that can provide shelter from UV radiation) in the effluent was very low. FC, P. aeruginosa sp. and S. aureus sp. did not exhibit regrowth up to 6 h after exposure to increasing UV doses (19-439 mW s cm-2). HPC regrowth was proven to be statistically significant in un-disinfected effluent and after irradiation with high UV doses (147 and 439 mW s cm-2). At these doses regrowth resulted from growth of UV-resistant bacteria due to decreased competition with other bacteria eliminated by the irradiation.",
keywords = "Bacteria, Coliphages, Disinfection kinetics, Greywater, Microbial quality, Regrowth, UV disinfection",
author = "Yael Gilboa and Eran Friedler",
note = "Funding Information: The financial support of the Israeli Water and Wastewater Authority and by The Grand Water Research Institute in the (GWRI) Technion is greatly acknowledged. The authors further wish to thank Assoc. Prof. R. Armon for his valuable advice and support throughout the research. Y. Gilboa further wishes to thank The Zackin Fund (GWRI) for the generous scholarship. ",
year = "2008",
month = feb,
doi = "10.1016/j.watres.2007.09.027",
language = "אנגלית",
volume = "42",
pages = "1043--1050",
journal = "Water Research",
issn = "0043-1354",
publisher = "Elsevier Ltd.",
number = "4-5",

}

Assessment of the reliability of an on-site MBR system for greywater treatment and the associated aesthetic and health risks

Friedler E, Shwartzman Z, Ostfeld A. Assessment of the reliability of an on-site MBR system for greywater treatment and the associated aesthetic and health risks. Water Science and Technology. 2008;57(7):1103-1110. https://doi.org/10.2166/wst.2008.248
 

This study analyses the reliability of an on-site MBR system for greywater treatment and reuse. To achieve this goal simulation was performed based on the IWA ASM1 model which was adapted to describe biological and physical mechanisms for MBR greywater treatment based systems. Model results were found to agree well with experimental data from an on site pilot greywater treatment plant, after which the calibrated model was used in a Monte Carlo mode for generating statistical data on the MBR system performance under different scenarios of failures and inflow loads variations. Effluents quality and their associated risks were successfully estimated.

@article{3574eef393ea4eeb84387e2b617dfe4a,
title = "Assessment of the reliability of an on-site MBR system for greywater treatment and the associated aesthetic and health risks",
abstract = "This study analyses the reliability of an on-site MBR system for greywater treatment and reuse. To achieve this goal simulation was performed based on the IWA ASM1 model which was adapted to describe biological and physical mechanisms for MBR greywater treatment based systems. Model results were found to agree well with experimental data from an on site pilot greywater treatment plant, after which the calibrated model was used in a Monte Carlo mode for generating statistical data on the MBR system performance under different scenarios of failures and inflow loads variations. Effluents quality and their associated risks were successfully estimated.",
keywords = "Greywater reuse, MBR, On-site treatment, Risk assessment, Simulation, Stochastic modeling",
author = "E. Friedler and Z. Shwartzman and A. Ostfeld",
year = "2008",
doi = "10.2166/wst.2008.248",
language = "אנגלית",
volume = "57",
pages = "1103--1110",
journal = "Water Science and Technology",
issn = "0273-1223",
publisher = "IWA Publishing",
number = "7",

}

2007

השפעת חיטוי בקרינת UV על האיכות המיקרוביאלית של מים אפורים

גלבע י, פרידלר ע. השפעת חיטוי בקרינת UV על האיכות המיקרוביאלית של מים אפורים. מים והשקיה: ירחון ארגון עובדי המים. 2007;491:24-30.
 
לאיכות התברואתית של מים אפורים, משנה חשיבות כאשר מדובר בהשבה מקומית זאת בשל המגע ההדוק יחסית בין המים המושבים לבין האוכלוסייה. לכן, המפתח להשבה בטוחה הוא תהליך חיטוי מיטבי.
@article{20c8d042116e42cc8fd194e9696a4200,
title = "השפעת חיטוי בקרינת UV על האיכות המיקרוביאלית של מים אפורים",
abstract = "לאיכות התברואתית של מים אפורים, משנה חשיבות כאשר מדובר בהשבה מקומית זאת בשל המגע ההדוק יחסית בין המים המושבים לבין האוכלוסייה. לכן, המפתח להשבה בטוחה הוא תהליך חיטוי מיטבי.",
author = "יעל גלבע and ערן פרידלר",
year = "2007",
language = "עברית",
volume = "491",
pages = "24--30",
journal = "מים והשקיה: ירחון ארגון עובדי המים",
issn = "0333-8835",

}

2006

Effects of design flow and treatment level on construction and operation costs of municipal wastewater treatment plants and their implications on policy making

Friedler E, Pisanty E. Effects of design flow and treatment level on construction and operation costs of municipal wastewater treatment plants and their implications on policy making. Water Research. 2006 Dec;40(20):3751-3758. https://doi.org/10.1016/j.watres.2006.08.015
 

Construction costs of 55 municipal wastewater treatment plants in Israel (secondary, advanced secondary, and advanced treatment) were analysed in order to derive cost functions expressing the effects of design flow and treatment level on construction costs. Three equations were derived (statistically significant, p<0.01), one for each treatment level. These indicate that economy of scale may become weaker as treatment level rises. Analysis of the distribution of construction costs revealed negative correlation (p<0.05) between the proportional cost of civil engineering and design flow, positive correlation (p<0.05) between the proportional cost of elecromechanical equipment and design flow, and no correlation between the proportional cost of electricity and control and design flow. Operation costs were found to be 20-70% more sensitive than construction costs to treatment level. The share of operation costs as part of the total annual costs was found to increase both with design flow and treatment level, whereas the share of construction costs concurrently decreased. The implication of the findings on policy, and consequently on treatment plants performance is discussed in the last part of the paper.

@article{6ee83c340c9945ffaf5614f68b4af6e8,
title = "Effects of design flow and treatment level on construction and operation costs of municipal wastewater treatment plants and their implications on policy making",
abstract = "Construction costs of 55 municipal wastewater treatment plants in Israel (secondary, advanced secondary, and advanced treatment) were analysed in order to derive cost functions expressing the effects of design flow and treatment level on construction costs. Three equations were derived (statistically significant, p<0.01), one for each treatment level. These indicate that economy of scale may become weaker as treatment level rises. Analysis of the distribution of construction costs revealed negative correlation (p<0.05) between the proportional cost of civil engineering and design flow, positive correlation (p<0.05) between the proportional cost of elecromechanical equipment and design flow, and no correlation between the proportional cost of electricity and control and design flow. Operation costs were found to be 20-70% more sensitive than construction costs to treatment level. The share of operation costs as part of the total annual costs was found to increase both with design flow and treatment level, whereas the share of construction costs concurrently decreased. The implication of the findings on policy, and consequently on treatment plants performance is discussed in the last part of the paper.",
keywords = "Construction, Cost, Design flow, Economy, Effluent quality, Operation, Policy, Wastewater treatment plants",
author = "Eran Friedler and Ehud Pisanty",
year = "2006",
month = dec,
doi = "10.1016/j.watres.2006.08.015",
language = "אנגלית",
volume = "40",
pages = "3751--3758",
journal = "Water Research",
issn = "0043-1354",
publisher = "Elsevier Ltd.",
number = "20",

}

Study of urban population attitudes towards various wastewater reuse options: Israel as a case study

Friedler E, Lahav O, Jizhaki H, Lahav T. Study of urban population attitudes towards various wastewater reuse options: Israel as a case study. Journal of Environmental Management. 2006 Dec;81(4):360-370. https://doi.org/10.1016/j.jenvman.2005.11.013
 

This paper summarizes the findings of a survey (256 participants) conducted to determine the attitude of the Israeli urban public towards various urban water reuse options. Israel is known for its long and successful agricultural water reuse scheme, but to date no large-scale urban reuse projects have been implemented. The survey included 21 reuse options, which were clustered into three reuse categories, namely: low, medium, and high contact levels. Results show that a high proportion of the participants supported medium contact reuse options such as sidewalk landscaping (95%), domestic WC flushing (85%) and firefighting (96%). Higher contact reuse options such as domestic laundry (38%), preserved food (13%), and potable aquifer recharge (11%) found much lesser support. Less than expected support was found for low contact reuse options with 86% for field crop irrigation, 62% for aquifer recharge for agricultural irrigation, and as low as 49% for orchard irrigation. This low support is surprising, since all three options have been practiced on a large scale for over three decades in Israel without any adverse effects to the public. No correlation was found between any biographical characteristic examined (education, gender, income, marital status, having young children, and age) and support for medium contact options. For the medium contact options, the results suggest that perceived financial gain (individual and/or communal) and positive public opinion enhances support, while perceived health effects negatively affects the degree of support. Technology, trust in authorities and awareness of water and environmental issues were found to not have a significant effect on support for medium contact reuse options. Analyzing the four possible reasons for support given by participants who identified themselves as supporters of wastewater reuse revealed that the most important reason for support was "water saving", followed by "minimization of importing water from abroad". These were followed by "infrastructure cost saving" together with "environmental improvement".

@article{89c9cfca88cd40c29d31b91590846305,
title = "Study of urban population attitudes towards various wastewater reuse options: Israel as a case study",
abstract = "This paper summarizes the findings of a survey (256 participants) conducted to determine the attitude of the Israeli urban public towards various urban water reuse options. Israel is known for its long and successful agricultural water reuse scheme, but to date no large-scale urban reuse projects have been implemented. The survey included 21 reuse options, which were clustered into three reuse categories, namely: low, medium, and high contact levels. Results show that a high proportion of the participants supported medium contact reuse options such as sidewalk landscaping (95%), domestic WC flushing (85%) and firefighting (96%). Higher contact reuse options such as domestic laundry (38%), preserved food (13%), and potable aquifer recharge (11%) found much lesser support. Less than expected support was found for low contact reuse options with 86% for field crop irrigation, 62% for aquifer recharge for agricultural irrigation, and as low as 49% for orchard irrigation. This low support is surprising, since all three options have been practiced on a large scale for over three decades in Israel without any adverse effects to the public. No correlation was found between any biographical characteristic examined (education, gender, income, marital status, having young children, and age) and support for medium contact options. For the medium contact options, the results suggest that perceived financial gain (individual and/or communal) and positive public opinion enhances support, while perceived health effects negatively affects the degree of support. Technology, trust in authorities and awareness of water and environmental issues were found to not have a significant effect on support for medium contact reuse options. Analyzing the four possible reasons for support given by participants who identified themselves as supporters of wastewater reuse revealed that the most important reason for support was {"}water saving{"}, followed by {"}minimization of importing water from abroad{"}. These were followed by {"}infrastructure cost saving{"} together with {"}environmental improvement{"}.",
keywords = "Public awareness, Public perception, Urban reuse, Wastewater reuse",
author = "Eran Friedler and Ori Lahav and Hagar Jizhaki and Tali Lahav",
year = "2006",
month = dec,
doi = "10.1016/j.jenvman.2005.11.013",
language = "אנגלית",
volume = "81",
pages = "360--370",
journal = "Journal of Environmental Management",
issn = "0301-4797",
publisher = "Academic Press Inc.",
number = "4",

}

A different approach for predicting reaeration rates in gravity sewers and completely mixed tanks

Lahav O, Binder A, Friedler E. A different approach for predicting reaeration rates in gravity sewers and completely mixed tanks. Water Environment Research. 2006 Jul;78(7):730-739. https://doi.org/10.2175/106143006X101764
 

A new semiempirical approach is presented for predicting air-to-water oxygen transfer rates in mixed tanks and gravity sewers, using methods adopted from mixing theory. First, a flocculation unit was used to impart selected mean velocity gradients (G) into a completely mixed tank, from which oxygen was first removed, and dissolved oxygen concentrations were measured with time. Regression analysis was used to fit the rate of oxygen transfer equation against G. The reaeration rate in completely mixed reactors was found to be proportional to G2 (R2 = 0.987). Subsequently, G was linked to headless in sewers, and the equation was calibrated using a slope-adjustable, 27-m-long, gravity-flow, experimental sewer (internal diameter, D = 0.16 m). Here, the reaeration rate was proportional to G 1 (R2 = 0.981). The equation was compared with existing oxygen transfer models and validated against experimental data from the literature, to which the overall mass transfer coefficient for oxygen, K La, derived by the new approach, conformed well.

@article{9cc3f4c615b445c5a3ce4364978826c5,
title = "A different approach for predicting reaeration rates in gravity sewers and completely mixed tanks",
abstract = "A new semiempirical approach is presented for predicting air-to-water oxygen transfer rates in mixed tanks and gravity sewers, using methods adopted from mixing theory. First, a flocculation unit was used to impart selected mean velocity gradients (G) into a completely mixed tank, from which oxygen was first removed, and dissolved oxygen concentrations were measured with time. Regression analysis was used to fit the rate of oxygen transfer equation against G. The reaeration rate in completely mixed reactors was found to be proportional to G2 (R2 = 0.987). Subsequently, G was linked to headless in sewers, and the equation was calibrated using a slope-adjustable, 27-m-long, gravity-flow, experimental sewer (internal diameter, D = 0.16 m). Here, the reaeration rate was proportional to G 1 (R2 = 0.981). The equation was compared with existing oxygen transfer models and validated against experimental data from the literature, to which the overall mass transfer coefficient for oxygen, K La, derived by the new approach, conformed well.",
keywords = "Gas transfer, Gravity sewers, Mean velocity gradient, Reaeration equation",
author = "Ori Lahav and Assaf Binder and Eran Friedler",
year = "2006",
month = jul,
doi = "10.2175/106143006X101764",
language = "אנגלית",
volume = "78",
pages = "730--739",
journal = "Water Environment Research",
issn = "1061-4303",
publisher = "Water Environment Federation",
number = "7",

}

Comparative study of the microbial quality of greywater treated by three on-site treatment systems

Friedler E, Kovalio R, Ben-Zvi A. Comparative study of the microbial quality of greywater treated by three on-site treatment systems. Environmental Technology (United Kingdom). 2006 Jun;27(6):653-663. https://doi.org/10.1080/09593332708618674
 

This paper analyses the performance of a pilot scale treatment plant, treating light domestic greywater. The treatment included three parallel treatment units: stand-alone sand filtration (SFEB), RBC followed by sand filtration (SFRBC), and an MBR equipped with UF membranes (MBR). The performance of the SPEB unit was rather poor. The RBC and MBR units produced effluent of excellent quality, with COD of 42 and 40 mg l-1, BOD of 1.8 and 1.1 mg l-1, and turbidity of 0.6 and 0.2 NTU respectively. The SFEB failed to remove heterotropbic microorganisms (HPC), while the SFRBC and the MBR exhibited 2.1 and 3.6 logs removal, leading to effluent concentrations of 1.1×105 and 8.8×103 cfu ml-1 respectively. Faecal coliforms (FC) counts were 3.4×105, 1.4×105, 1.1×103 and 3.5×102 cfu 100 ml-1 in raw greywater, and in the SFEB, SFRBC and MBR effluents respectively. Further, in 60% of the samples no FC were detected in the MBR effluent. In order to simulate residence times in full scale systems, effluents were disinfected and stored for 0.5 h, 3 4 6 h (normal operation), and one week (extreme event). The average chlorine demand was 8.1, 3.8 and 2.9 mg l-1 for SFEB, SFRBC and MBR effluents respectively. Low residual chlorine (0.15-0.22 mg l-1) remained in all effluents even after a week-long storage. Disinfection reduced HPC by 5, 2 and 2 orders of magnitude in the SFEB, SFRBC and MBR effluents respectively, with no regrowth in short contact times (up to 6 hours). Some regrowth was observed after a week-long storage leading to 106, 104' and 103' cfu ml-1' (SFEB SFRBC and MBR respectively). Disinfection reduced FC counts in all three types of effluent to 0 cfu 100 ml-1, whilst no FC regrowth was observed after week-long storage. The results show that both RBC and MBR treatment units are viable options for on-site greywater reuse. The disinfection experiments strongly indicate that the health risk associated with the reuse of these effluents is minimal even after long period of storage.

@article{dced50007e6541159b5b70d85c8823f1,
title = "Comparative study of the microbial quality of greywater treated by three on-site treatment systems",
abstract = "This paper analyses the performance of a pilot scale treatment plant, treating light domestic greywater. The treatment included three parallel treatment units: stand-alone sand filtration (SFEB), RBC followed by sand filtration (SFRBC), and an MBR equipped with UF membranes (MBR). The performance of the SPEB unit was rather poor. The RBC and MBR units produced effluent of excellent quality, with COD of 42 and 40 mg l-1, BOD of 1.8 and 1.1 mg l-1, and turbidity of 0.6 and 0.2 NTU respectively. The SFEB failed to remove heterotropbic microorganisms (HPC), while the SFRBC and the MBR exhibited 2.1 and 3.6 logs removal, leading to effluent concentrations of 1.1×105 and 8.8×103 cfu ml-1 respectively. Faecal coliforms (FC) counts were 3.4×105, 1.4×105, 1.1×103 and 3.5×102 cfu 100 ml-1 in raw greywater, and in the SFEB, SFRBC and MBR effluents respectively. Further, in 60% of the samples no FC were detected in the MBR effluent. In order to simulate residence times in full scale systems, effluents were disinfected and stored for 0.5 h, 3 4 6 h (normal operation), and one week (extreme event). The average chlorine demand was 8.1, 3.8 and 2.9 mg l-1 for SFEB, SFRBC and MBR effluents respectively. Low residual chlorine (0.15-0.22 mg l-1) remained in all effluents even after a week-long storage. Disinfection reduced HPC by 5, 2 and 2 orders of magnitude in the SFEB, SFRBC and MBR effluents respectively, with no regrowth in short contact times (up to 6 hours). Some regrowth was observed after a week-long storage leading to 106, 104' and 103' cfu ml-1' (SFEB SFRBC and MBR respectively). Disinfection reduced FC counts in all three types of effluent to 0 cfu 100 ml-1, whilst no FC regrowth was observed after week-long storage. The results show that both RBC and MBR treatment units are viable options for on-site greywater reuse. The disinfection experiments strongly indicate that the health risk associated with the reuse of these effluents is minimal even after long period of storage.",
keywords = "Disinfection, Faecal coliforms, Greywater treatment, Heterotrophic plate count, Microbial quality",
author = "E. Friedler and R. Kovalio and A. Ben-Zvi",
note = "Funding Information: The research was financed by the Israeli Water Commission and by The Grand Water Research Institute in the Technion.",
year = "2006",
month = jun,
doi = "10.1080/09593332708618674",
language = "אנגלית",
volume = "27",
pages = "653--663",
journal = "Environmental Technology (United Kingdom)",
issn = "0959-3330",
publisher = "Taylor and Francis Ltd.",
number = "6",

}

Economic feasibility of on-site greywater reuse in multi-storey buildings

Friedler E, Hadari M. Economic feasibility of on-site greywater reuse in multi-storey buildings. Desalination. 2006 Apr 15;190(1-3):221-234. https://doi.org/10.1016/j.desal.2005.10.007
 

This paper analyses the economic feasibility of on-site greywater reuse in the urban sector. RBC- and MBR-based systems were selected as model systems for the economic analysis. The analysis showed that the investment costs of an RBC-based system consist of less than 0.5% of the price of a flat for buildings of more than 20 flats (five storeys). At a water price of 1.16 US$/m3 and sewage charges of 0.3 US$/m3, the RBC-based system became economically feasible when the building size reached seven storeys (28 flats). The on-site MBR-based system proved to be economically unrealistic, becoming economically feasible only when the building size exceeded 40 storeys. Cluster MBR-based systems, incorporating several buildings together, became feasible when the cluster size was four buildings or more (each 10 storeys high). A subsidy of 0.7 US$/m3 reused resulted in much smaller systems becoming economically feasible: Four-storey buildings (16 flats) for the RBC system and two buildings for the cluster MBR system. The on-site MBR system (single building) remained unfeasible.

@article{52cd85c5201142a0855140fba23e6b8d,
title = "Economic feasibility of on-site greywater reuse in multi-storey buildings",
abstract = "This paper analyses the economic feasibility of on-site greywater reuse in the urban sector. RBC- and MBR-based systems were selected as model systems for the economic analysis. The analysis showed that the investment costs of an RBC-based system consist of less than 0.5% of the price of a flat for buildings of more than 20 flats (five storeys). At a water price of 1.16 US$/m3 and sewage charges of 0.3 US$/m3, the RBC-based system became economically feasible when the building size reached seven storeys (28 flats). The on-site MBR-based system proved to be economically unrealistic, becoming economically feasible only when the building size exceeded 40 storeys. Cluster MBR-based systems, incorporating several buildings together, became feasible when the cluster size was four buildings or more (each 10 storeys high). A subsidy of 0.7 US$/m3 reused resulted in much smaller systems becoming economically feasible: Four-storey buildings (16 flats) for the RBC system and two buildings for the cluster MBR system. The on-site MBR system (single building) remained unfeasible.",
keywords = "Cost benefit analysis, Decentralised reuse, Economic aspects, Greywater reuse, Urban, MBR, On-site treatment, RBC",
author = "Eran Friedler and M. Hadari",
note = "Funding Information: Financial support from the Grand Water Research Institute, the Technion, and the Israeli Water Commission is greatly appreciated. The authors further wish to thank the manufacturers and distributors (local and international) who courteously supplied us information on the capital and O&M costs of various units.",
year = "2006",
month = apr,
day = "15",
doi = "10.1016/j.desal.2005.10.007",
language = "אנגלית",
volume = "190",
pages = "221--234",
journal = "Desalination",
issn = "0011-9164",
publisher = "Elsevier",
number = "1-3",

}

A different approach for predicting H2S(g) emission rates in gravity sewers

Lahav O, Sagiv A, Friedler E. A different approach for predicting H2S(g) emission rates in gravity sewers. Water Research. 2006 Jan;40(2):259-266. https://doi.org/10.1016/j.watres.2005.10.026
 

All detrimental phenomena (malodors, metal corrosion, concrete disintegration, health hazard) associated with hydrogen sulfide in gravity sewers depend on the rate of H2S emission from the aqueous phase to the gas phase of the pipe. In this paper a different approach for predicting H2S(g) emission rates from gravity sewers is presented, using concepts adapted from mixing theory. The mean velocity gradient (G=γSV/μ; S is the slope, V the mean velocity), representing mixing conditions in gravity flow, was used to quantify the rate of H2S (g) emission in part-full gravity sewers. Based on this approach an emission equation was developed. The equation was verified and calibrated by performing 20 experiments in a 27-m gravity-flow experimental-sewer (D=0.16m) at various hydraulic conditions. Results indicate a clear dependency of the sulfide stripping-rate on G1 (R2=0.94) with the following overall emission equation:-d[ST]dt=8×10-7γSV/μwAcs1.024(T-20)(ST1+Ks110- pH+Ks1Ks210-2pH-PpH2SKH), where ST is the total sulfide concentration in the aqueous phase, mg/L; w the flow surface width, m; Acs the cross-sectional area, m2; T the temperature,°C; KH the Henry's constant, mol L-1 atm-1; and PpH2S the partial pressure of H2S(g) in the sewer atmosphere, atm.

@article{a5aed27694e1480780a117c0fa1db90d,
title = "A different approach for predicting H2S(g) emission rates in gravity sewers",
abstract = "All detrimental phenomena (malodors, metal corrosion, concrete disintegration, health hazard) associated with hydrogen sulfide in gravity sewers depend on the rate of H2S emission from the aqueous phase to the gas phase of the pipe. In this paper a different approach for predicting H2S(g) emission rates from gravity sewers is presented, using concepts adapted from mixing theory. The mean velocity gradient (G=γSV/μ; S is the slope, V the mean velocity), representing mixing conditions in gravity flow, was used to quantify the rate of H2S (g) emission in part-full gravity sewers. Based on this approach an emission equation was developed. The equation was verified and calibrated by performing 20 experiments in a 27-m gravity-flow experimental-sewer (D=0.16m) at various hydraulic conditions. Results indicate a clear dependency of the sulfide stripping-rate on G1 (R2=0.94) with the following overall emission equation:-d[ST]dt=8×10-7γSV/μwAcs1.024(T-20)(ST1+Ks110- pH+Ks1Ks210-2pH-PpH2SKH), where ST is the total sulfide concentration in the aqueous phase, mg/L; w the flow surface width, m; Acs the cross-sectional area, m2; T the temperature,°C; KH the Henry's constant, mol L-1 atm-1; and PpH2S the partial pressure of H2S(g) in the sewer atmosphere, atm.",
keywords = "Gas transfer, Gravity sewers, HS emission, Mean velocity gradient",
author = "Ori Lahav and Amitai Sagiv and Eran Friedler",
year = "2006",
month = jan,
doi = "10.1016/j.watres.2005.10.026",
language = "אנגלית",
volume = "40",
pages = "259--266",
journal = "Water Research",
issn = "0043-1354",
publisher = "Elsevier Ltd.",
number = "2",

}

Centralised urban wastewater reuse: What is the public attitude?

Friedler E, Lahav O. Centralised urban wastewater reuse: What is the public attitude? In Mikkelsen PS, Ledin A, Hvitved-Jacobsen T, editors, Urban Drainage 2005. 6-7 ed. 2006. p. 423-430. (Water Science and Technology; 6-7). https://doi.org/10.2166/wst.2006.605
 

Public support is crucial for successful implementation of wastewater reuse projects. This paper analyses the findings of a questionnaire-type survey (256 participants) conducted to determine the attitude of Israeli urban public towards possible urban reuse options. The paper summarises the support / objection to 13 reuse options and the correlation between support and environmental awareness and perceptions. Results show that a high proportion of the participants supported options perceived as low-contact, such as irrigation of public parks (96%), sidewalk landscaping (95%) and use in the construction industry (94%), while higher-contact reuse options found less support (e.g. commercial launderettes, 60%). No correlation was found between biographical characteristics and support (education, gender, income, age). Based on the results, public campaigns in Israel should focus on disseminating information regarding wastewater treatment technologies, discuss health related issues, highlight the positive economic impact of water reuse and generate a positive public opinion, as these factors tend to influence individuals to support reuse projects.

@inbook{d4eb76be15454c759ce882e11b860626,
title = "Centralised urban wastewater reuse: What is the public attitude?",
abstract = "Public support is crucial for successful implementation of wastewater reuse projects. This paper analyses the findings of a questionnaire-type survey (256 participants) conducted to determine the attitude of Israeli urban public towards possible urban reuse options. The paper summarises the support / objection to 13 reuse options and the correlation between support and environmental awareness and perceptions. Results show that a high proportion of the participants supported options perceived as low-contact, such as irrigation of public parks (96%), sidewalk landscaping (95%) and use in the construction industry (94%), while higher-contact reuse options found less support (e.g. commercial launderettes, 60%). No correlation was found between biographical characteristics and support (education, gender, income, age). Based on the results, public campaigns in Israel should focus on disseminating information regarding wastewater treatment technologies, discuss health related issues, highlight the positive economic impact of water reuse and generate a positive public opinion, as these factors tend to influence individuals to support reuse projects.",
keywords = "Public awareness, Public perception, Social aspects, Survey, Wastewater reuse",
author = "Eran Friedler and O. Lahav",
year = "2006",
doi = "10.2166/wst.2006.605",
language = "אנגלית",
isbn = "1843395746",
series = "Water Science and Technology",
number = "6-7",
pages = "423--430",
editor = "P.S. Mikkelsen and A. Ledin and T. Hvitved-Jacobsen",
booktitle = "Urban Drainage 2005",
edition = "6-7",

}

2005

On-site greywater treatment and reuse in multi-storey buildings

Friedler E, Kovalio R, Galil NI. On-site greywater treatment and reuse in multi-storey buildings. Water Science and Technology. 2005;51(10):187-194. https://doi.org/10.2166/wst.2005.0366
 

The paper presents a study of a pilot plant treating light greywater for seven flats. The pilot plant combines biological treatment (RBC) with physicochemical treatment (sand filtration and disinfection). The pilot plant produced effluent of excellent quality, meeting the urban reuse quality regulations, and was very efficient in TSS turbidity and BOD removal: 82%, 98% and 96%, respectively. COD removal was somewhat lower (70-75%) indicating that the greywater may contain slowly-biodegradable organics. The RBC (attached growth biological system) was able to retain most of the solids as a result of bioflocculation; further it was proven to have very stable and reliable performance. Faecal coliforms and heterotrophic reductions were very high (100% and 99.99%, respectively) producing effluent that also met drinking water standards. The combination of low organic matter, nutrients and microbial indicators reduces the regrowth and fouling potentials in the reuse system, thus ensuring safe reuse of the treated greywater for toilet flushing.

@article{f50e7474749945af983ab85d19642ca9,
title = "On-site greywater treatment and reuse in multi-storey buildings",
abstract = "The paper presents a study of a pilot plant treating light greywater for seven flats. The pilot plant combines biological treatment (RBC) with physicochemical treatment (sand filtration and disinfection). The pilot plant produced effluent of excellent quality, meeting the urban reuse quality regulations, and was very efficient in TSS turbidity and BOD removal: 82%, 98% and 96%, respectively. COD removal was somewhat lower (70-75%) indicating that the greywater may contain slowly-biodegradable organics. The RBC (attached growth biological system) was able to retain most of the solids as a result of bioflocculation; further it was proven to have very stable and reliable performance. Faecal coliforms and heterotrophic reductions were very high (100% and 99.99%, respectively) producing effluent that also met drinking water standards. The combination of low organic matter, nutrients and microbial indicators reduces the regrowth and fouling potentials in the reuse system, thus ensuring safe reuse of the treated greywater for toilet flushing.",
keywords = "Biological treatment, Greywater reuse, On-site, Pilot plant, Quality, RBC, Sand filtration",
author = "Eran Friedler and R. Kovalio and Galil, {N. I.}",
year = "2005",
doi = "10.2166/wst.2005.0366",
language = "אנגלית",
volume = "51",
pages = "187--194",
journal = "Water Science and Technology",
issn = "0273-1223",
publisher = "IWA Publishing",
number = "10",

}

חומרי ניקוי למדיחי כלים - כיצד הם משפיעים על המלחת השפכים העירוניים?

נתן א, פרידלר ע, רזניצקי ל. חומרי ניקוי למדיחי כלים - כיצד הם משפיעים על המלחת השפכים העירוניים? מים והשקיה: ירחון ארגון עובדי המים. 2005;461:14-17.
 
עומס זיהום השפכים בנתרן וכלורידים הנובעים מחומרי הניקוי במדיחי הכלים, עולה ועומד השנה על 19-17 טון. עומס הזיהום בבורון בשפכים משפיעה על איכות הקולחין וגורמת לנזקים סביבתיים.
@article{40cdeacecbc04db5a1f49a35e3103d4b,
title = "חומרי ניקוי למדיחי כלים - כיצד הם משפיעים על המלחת השפכים העירוניים?",
abstract = "עומס זיהום השפכים בנתרן וכלורידים הנובעים מחומרי הניקוי במדיחי הכלים, עולה ועומד השנה על 19-17 טון. עומס הזיהום בבורון בשפכים משפיעה על איכות הקולחין וגורמת לנזקים סביבתיים.",
author = "אתי נתן and ערן פרידלר and לינור רזניצקי",
year = "2005",
language = "עברית",
volume = "461",
pages = "14--17",
journal = "מים והשקיה: ירחון ארגון עובדי המים",
issn = "0333-8835",

}

2004

Quality of individual domestic greywater streams and its implication for on-site treatment and reuse possibilities

Friedler E. Quality of individual domestic greywater streams and its implication for on-site treatment and reuse possibilities. Environmental Technology (United Kingdom). 2004;25(9):997-1008. https://doi.org/10.1080/09593330.2004.9619393
 

A sampling campaign was conducted in order to characterise the quality and quantity of individual domestic greywater streams. Based on results, various scenarios of inclusion and / or exclusion of different greywater streams were explored, and their implication for on-site greywater treatment and reuse options are discussed. Domestic greywater was found to contribute as much as 55-70% of the specific daily load of TSS and BOD, in municipal sewage. The kitchen sink was signalled out as a major contributor of VSS, COD, and BCD, with 58%, 42% and 48%, of their total daily load respectively. The washing machine was established as a significant contributor of sodium, phosphate and COD, (40%, 37% and 22% of the total load). The dishwasher, although contributing only 5% of the flow, was found to be a significant contributor of phosphate and boron. The wash basin was found to be the least polluting appliance. As "demand" for greywater within the urban environment is lower than its "production", it is logical to recycle only the less polluted greywater streams. In order to explore the consequences of the above concept on discharge volume, pollutants loads and concentrations, 18 scenarios were studied, in each at least one stream was excluded from the combined greywater stream. Exclusion of the joined stream of the kitchen sink plus the highly polluted streams of the washing machine (wash + 1st rinse) and dishwasher (pre-rinse + wash) significantly improved greywater quality, with the advantage of leaving enough greywater to be reused (65-701/c/d).

@article{642044be2e254a3caf8fcf3ac63a11bf,
title = "Quality of individual domestic greywater streams and its implication for on-site treatment and reuse possibilities",
abstract = "A sampling campaign was conducted in order to characterise the quality and quantity of individual domestic greywater streams. Based on results, various scenarios of inclusion and / or exclusion of different greywater streams were explored, and their implication for on-site greywater treatment and reuse options are discussed. Domestic greywater was found to contribute as much as 55-70% of the specific daily load of TSS and BOD, in municipal sewage. The kitchen sink was signalled out as a major contributor of VSS, COD, and BCD, with 58%, 42% and 48%, of their total daily load respectively. The washing machine was established as a significant contributor of sodium, phosphate and COD, (40%, 37% and 22% of the total load). The dishwasher, although contributing only 5% of the flow, was found to be a significant contributor of phosphate and boron. The wash basin was found to be the least polluting appliance. As {"}demand{"} for greywater within the urban environment is lower than its {"}production{"}, it is logical to recycle only the less polluted greywater streams. In order to explore the consequences of the above concept on discharge volume, pollutants loads and concentrations, 18 scenarios were studied, in each at least one stream was excluded from the combined greywater stream. Exclusion of the joined stream of the kitchen sink plus the highly polluted streams of the washing machine (wash + 1st rinse) and dishwasher (pre-rinse + wash) significantly improved greywater quality, with the advantage of leaving enough greywater to be reused (65-701/c/d).",
keywords = "Alternative water resource, Greywater characterisation, On-site treatment, Stream separation, Sustainable water use",
author = "E. Friedler",
note = "Funding Information: This research is partially financed by the Israeli Ministry of Infrastructure, The Grand Water Research Institute in the Technion, and the Technion V.P.R. Fund – W.",
year = "2004",
doi = "10.1080/09593330.2004.9619393",
language = "אנגלית",
volume = "25",
pages = "997--1008",
journal = "Environmental Technology (United Kingdom)",
issn = "0959-3330",
publisher = "Taylor and Francis Ltd.",
number = "9",

}

שימוש חוזר במים אפורים להדחת אסלות במגזר העירוני - פתרון בר-קיימא לחסכון

פרידלר ע. שימוש חוזר במים אפורים להדחת אסלות במגזר העירוני - פתרון בר-קיימא לחסכון. מים והשקיה: ירחון ארגון עובדי המים. 2004;458:18-22.
 
במסגרת מחקר של הטכניון הוקם בבניין רב קומות מתקן חלוץ להשבת מים אפורים, המייצר קולחים מטוהרים באיכות גבוהה מאוד. מחזור כזה יכול להקטין משמעותית את צריכת המים העירונית, במידה שייושם בקנה מידה גדול תגובתה של הדסה אדן למאמר בגיליון מס' 459, עמוד 31, 2005, ותשובתו של המחבר בעמוד 33
@article{2d95a430c64d4a4791e3b826ae9f871d,
title = "שימוש חוזר במים אפורים להדחת אסלות במגזר העירוני - פתרון בר-קיימא לחסכון",
abstract = "במסגרת מחקר של הטכניון הוקם בבניין רב קומות מתקן חלוץ להשבת מים אפורים, המייצר קולחים מטוהרים באיכות גבוהה מאוד. מחזור כזה יכול להקטין משמעותית את צריכת המים העירונית, במידה שייושם בקנה מידה גדול תגובתה של הדסה אדן למאמר בגיליון מס' 459, עמוד 31, 2005, ותשובתו של המחבר בעמוד 33",
author = "ערן פרידלר",
year = "2004",
language = "עברית",
volume = "458",
pages = "18--22",
journal = "מים והשקיה: ירחון ארגון עובדי המים",
issn = "0333-8835",

}

2003

Simulation model of wastewater stabilization reservoirs

Friedler E, Juanico M, Shelef G. Simulation model of wastewater stabilization reservoirs. Ecological Engineering. 2003 May;20(2):121-145. https://doi.org/10.1016/S0925-8574(03)00009-0
 

Stabilization reservoirs are hypertrophic aquatic systems functioning under non-steady-state conditions. The use of stabilization reservoirs is especially suitable for warm countries suffering from water shortage, where regulation between wastewater production and effluent utilization is needed. Stabilization reservoirs can significantly improve effluent quality; however, only few models have been developed to date. Today, with growing demand for high quality effluent, better understanding of the processes occurring in the reservoirs is needed. This paper describes the development of a mechanistic simulation model that integrates knowledge from the fields of wastewater treatment and limnology. The model has five quality variables in the waterbody and two in the sediment. It was calibrated and verified on three stabilization reservoirs in Israel and exhibited good agreement with observations. Different design and operation alternatives were studied, and some are discussed in this paper. The prediction ability of the model turns it into a useful research and design tool for studying the influence of various design and operation alternatives on the reservoirs' efficiency as wastewater treatment units.

@article{65d9c6e8c4074423be366e9934596ce0,
title = "Simulation model of wastewater stabilization reservoirs",
abstract = "Stabilization reservoirs are hypertrophic aquatic systems functioning under non-steady-state conditions. The use of stabilization reservoirs is especially suitable for warm countries suffering from water shortage, where regulation between wastewater production and effluent utilization is needed. Stabilization reservoirs can significantly improve effluent quality; however, only few models have been developed to date. Today, with growing demand for high quality effluent, better understanding of the processes occurring in the reservoirs is needed. This paper describes the development of a mechanistic simulation model that integrates knowledge from the fields of wastewater treatment and limnology. The model has five quality variables in the waterbody and two in the sediment. It was calibrated and verified on three stabilization reservoirs in Israel and exhibited good agreement with observations. Different design and operation alternatives were studied, and some are discussed in this paper. The prediction ability of the model turns it into a useful research and design tool for studying the influence of various design and operation alternatives on the reservoirs' efficiency as wastewater treatment units.",
keywords = "Modelling, Stabilization reservoirs, Wastewater reuse, Wastewater storage, Wastewater treatment",
author = "Eran Friedler and Marcelo Juanico and Gedalia Shelef",
year = "2003",
month = may,
doi = "10.1016/S0925-8574(03)00009-0",
language = "אנגלית",
volume = "20",
pages = "121--145",
journal = "Ecological Engineering",
issn = "0925-8574",
publisher = "Elsevier",
number = "2",

}

Domestic greywater characterization and its implication on treatment and reuse potential: In: Chapter 7: Effectiveness of water conservation options

Friedler E, Galil N. Domestic greywater characterization and its implication on treatment and reuse potential: In: Chapter 7: Effectiveness of water conservation options. In Maksimovich C, Butler D, Memon F, editors, Effectiveness of water conservation options, In: Advances in Water Supply Management. A.A. Balkema Publishers. 2003. p. 535
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booktitle = "Effectiveness of water conservation options, In: Advances in Water Supply Management",
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}

2001

Water reuse - An integral part of water resources management: Israel as a case study

Friedler E. Water reuse - An integral part of water resources management: Israel as a case study. Water Policy. 2001;3(1):29-39. https://doi.org/10.1016/S1366-7017(01)00003-4
 

Treated wastewater may be considered as a 'new' water resource, which can be added to the general water balance of a region. This 'new' source can substitute conventional water used for irrigation. Israel is presently reusing more than 65% of the total domestic sewage production of the country, and it is planned to reach more than 90% reuse during the next decade. This paper addresses the introduction of reclaimed wastewater in the water balance of the country, its contribution to the protection of the conventional water resources, the similarities and differences between water and wastewater resources management, and the economic benefits of wastewater reuse.

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title = "Water reuse - An integral part of water resources management: Israel as a case study",
abstract = "Treated wastewater may be considered as a 'new' water resource, which can be added to the general water balance of a region. This 'new' source can substitute conventional water used for irrigation. Israel is presently reusing more than 65% of the total domestic sewage production of the country, and it is planned to reach more than 90% reuse during the next decade. This paper addresses the introduction of reclaimed wastewater in the water balance of the country, its contribution to the protection of the conventional water resources, the similarities and differences between water and wastewater resources management, and the economic benefits of wastewater reuse.",
author = "Eran Friedler",
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number = "1",

}

2000

שימוש בקולחין מושבים לשיקום נחלים בישראל

פרידלר ע, חואניקו מ. שימוש בקולחין מושבים לשיקום נחלים בישראל. מים והשקיה: ירחון ארגון עובדי המים. 2000;399:3-11.
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title = "שימוש בקולחין מושבים לשיקום נחלים בישראל",
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year = "2000",
language = "עברית",
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pages = "3--11",
journal = "מים והשקיה: ירחון ארגון עובדי המים",
issn = "0333-8835",

}

1999

At-source domestic wastewater quality

Almeida MC, Butler D, Friedler E. At-source domestic wastewater quality. Urban Water. 1999 Mar;1(1):49-55. https://doi.org/10.1016/s1462-0758(99)00008-4
 

Accurate measurement of flow and quality determinands for single or small numbers of dwellings is difficult due to the intermittent nature of flows at source. In this paper, at-source pollutographs are calculated using an alternative approach based on survey data of domestic appliance usage together with measured flow and loads per use. The wastewater pollutograph is built up from the contributions of various appliances. The individual usage of each appliance has been characterised by its frequency together with discharge, duration and loads. The proposed methodology can be used to derive dry weather flow inputs to water quality models, and to assess the impact of changes in local water use and treatment.

@article{733474d9a95c47849f7d83d1d5785393,
title = "At-source domestic wastewater quality",
abstract = "Accurate measurement of flow and quality determinands for single or small numbers of dwellings is difficult due to the intermittent nature of flows at source. In this paper, at-source pollutographs are calculated using an alternative approach based on survey data of domestic appliance usage together with measured flow and loads per use. The wastewater pollutograph is built up from the contributions of various appliances. The individual usage of each appliance has been characterised by its frequency together with discharge, duration and loads. The proposed methodology can be used to derive dry weather flow inputs to water quality models, and to assess the impact of changes in local water use and treatment.",
keywords = "Domestic appliances, Domestic wastewater, Dry weather flow, Faeces, Flow quality, Toilet paper, Urine, Wastewater reduction, Water closet (WC)",
author = "Almeida, {M. C.} and D. Butler and E. Friedler",
year = "1999",
month = mar,
doi = "10.1016/s1462-0758(99)00008-4",
language = "אנגלית",
volume = "1",
pages = "49--55",
journal = "Urban Water",
issn = "1462-0758",
publisher = "Elsevier BV",
number = "1",

}

Experiences outside Israel

Juanico M, Friedler E. Experiences outside Israel. In Juanico M, Dor I, editors, Reservoirs for wastewater storage and reuse: Ecology, performance & engineering design. Springer Verlag. 1999. p. 283
@inbook{6b90c633d2dd40559f27846a306c0a56,
title = "Experiences outside Israel",
author = "Marcelo Juanico and Eran Friedler",
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language = "American English",
pages = "283",
editor = "M Juanico and I Dor",
booktitle = "Reservoirs for wastewater storage and reuse",
publisher = "Springer Verlag",

}

Hydraulic age distribution

Juanico M, Friedler E. Hydraulic age distribution. In Juanico M, Dor I, editors, Reservoirs for wastewater storage and reuse: Ecology, performance & engineering design. Springer Verlag. 1999. p. 85
@inbook{b94ca58c047148abb4e661f80ca00a44,
title = "Hydraulic age distribution",
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author = "Marcelo Juanico and Eran Friedler",
year = "1999",
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isbn = "9783540655985",
pages = "85",
editor = "M Juanico and I Dor",
booktitle = "Reservoirs for wastewater storage and reuse",
publisher = "Springer Verlag",

}

Modelling

Friedler E. Modelling. In Juanico M, Dor I, editors, Reservoirs for wastewater storage and reuse : Ecology, performance & engineering design. Springer Verlag. 1999. p. 105
@inbook{e24ebc6b735f4d30b3a6a3e104fbe6d3,
title = "Modelling",
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year = "1999",
language = "American English",
isbn = "9783540655985",
pages = "105",
editor = "M Juanico and I Dor",
booktitle = "Reservoirs for wastewater storage and reuse ",
publisher = "Springer Verlag",

}

The Jeezrael Valley project for wastewater reclamation and reuse, Israel

Friedler E. The Jeezrael Valley project for wastewater reclamation and reuse, Israel. Water Science and Technology. 1999;40(4-5):347-354. https://doi.org/10.1016/S0273-1223(99)00517-X
 

The Jeezrael Valley is one of the richest agricultural regions of Israel, with urban communities in and around the valley. Irrigation in the valley follows the general trend of irrigation in Israel, where potable water is replaced by reclaimed wastewater. In the near future, reclaimed effluent is expected to form 80% of all irrigation water used in valley. This paper discusses a new regional wastewater reclamation and reuse project in the Jeezrael Valley which takes advantage of the proximity of the urban communities to the cultivated areas. The project combines semi-intensive wastewater treatment plants situated near the urban areas with wastewater reservoirs situated in the rural areas. The rationale behind the scheme is discussed and the performance during the first year of operation is presented. During this first year this combined reclamation system was able to release effluent of high quality. The system is expected to release effluent of unrestricted irrigation quality when all its components are installed, enabling the reservoirs to be operated in a full sequential batch mode.

@article{2d27ce2080f04416afc93cb345e06473,
title = "The Jeezrael Valley project for wastewater reclamation and reuse, Israel",
abstract = "The Jeezrael Valley is one of the richest agricultural regions of Israel, with urban communities in and around the valley. Irrigation in the valley follows the general trend of irrigation in Israel, where potable water is replaced by reclaimed wastewater. In the near future, reclaimed effluent is expected to form 80% of all irrigation water used in valley. This paper discusses a new regional wastewater reclamation and reuse project in the Jeezrael Valley which takes advantage of the proximity of the urban communities to the cultivated areas. The project combines semi-intensive wastewater treatment plants situated near the urban areas with wastewater reservoirs situated in the rural areas. The rationale behind the scheme is discussed and the performance during the first year of operation is presented. During this first year this combined reclamation system was able to release effluent of high quality. The system is expected to release effluent of unrestricted irrigation quality when all its components are installed, enabling the reservoirs to be operated in a full sequential batch mode.",
keywords = "Aerated lagoons, Anaerobic ponds, Irrigation, Sewage treatment, Wastewater reservoirs, Water reuse",
author = "Eran Friedler",
year = "1999",
doi = "10.1016/S0273-1223(99)00517-X",
language = "אנגלית",
volume = "40",
pages = "347--354",
journal = "Water Science and Technology",
issn = "0273-1223",
publisher = "IWA Publishing",
number = "4-5",
note = "Proceedings of the 1998 6th International Conference on Advanced Wastewater Treatment, Recycling and Reuse ; Conference date: 14-09-1998 Through 16-09-1998",

}

Wastewater reuse for river recovery in semi-arid Israel

Juanico M, Friedler E. Wastewater reuse for river recovery in semi-arid Israel. Water Science and Technology. 1999;40(4-5):43-50. https://doi.org/10.1016/S0273-1223(99)00484-9
 

Most of the water has been captured in the rivers of Israel and they have turned into dry river-beds which deliver only sporadic winter floods. In a semi-arid country where literally every drop of water is used, reclaimed wastewater is the most feasible water source for river recovery. Two topics are addressed in this paper: water quality management in rivers where most of the flowing water is treated wastewater, and the allocations of reclaimed wastewater required for the recovery of rivers and streams. Water quality management must consider that the main source of water to the river has a pollution loading which reduces its capability to absorb other pollution impacts. The allocation of treated wastewater for the revival of rivers may not affect negatively the water balance of the region; it may eventually improve it. An upstream brute allocation of 122 MCM/year of wastewater for the recovery of 14 rivers in Israel may favor downstream reuse of this wastewater, resulting in a small neto allocation and in an increase of the water resources available to the country. The discharge of effluents upstream to revive the river followed by their re-capture downstream for irrigation, implies a further stage in the intensification of water reuse.

@article{c8a57353381748a7af92367998bf10ad,
title = "Wastewater reuse for river recovery in semi-arid Israel",
abstract = "Most of the water has been captured in the rivers of Israel and they have turned into dry river-beds which deliver only sporadic winter floods. In a semi-arid country where literally every drop of water is used, reclaimed wastewater is the most feasible water source for river recovery. Two topics are addressed in this paper: water quality management in rivers where most of the flowing water is treated wastewater, and the allocations of reclaimed wastewater required for the recovery of rivers and streams. Water quality management must consider that the main source of water to the river has a pollution loading which reduces its capability to absorb other pollution impacts. The allocation of treated wastewater for the revival of rivers may not affect negatively the water balance of the region; it may eventually improve it. An upstream brute allocation of 122 MCM/year of wastewater for the recovery of 14 rivers in Israel may favor downstream reuse of this wastewater, resulting in a small neto allocation and in an increase of the water resources available to the country. The discharge of effluents upstream to revive the river followed by their re-capture downstream for irrigation, implies a further stage in the intensification of water reuse.",
keywords = "Mediterranean, River recovery, Water allocations, Water quality, Water reuse",
author = "Marcelo Juanico and Eran Friedler",
year = "1999",
doi = "10.1016/S0273-1223(99)00484-9",
language = "אנגלית",
volume = "40",
pages = "43--50",
journal = "Water Science and Technology",
issn = "0273-1223",
publisher = "IWA Publishing",
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note = "Proceedings of the 1998 6th International Conference on Advanced Wastewater Treatment, Recycling and Reuse ; Conference date: 14-09-1998 Through 16-09-1998",

}

בעיות הנגרמות כתוצאה מהמצאות שמנים ושומנים בשפכים

פרידלר ע, חואניקו מ. בעיות הנגרמות כתוצאה מהמצאות שמנים ושומנים בשפכים. בריאות מהשטח: הבטאון לבריאות הסביבה והמזון. 1999;7:20-22.
@article{ae86f7822f354e5682786a71193f478c,
title = "בעיות הנגרמות כתוצאה מהמצאות שמנים ושומנים בשפכים",
author = "ערן פרידלר and מרסלו חואניקו",
year = "1999",
language = "עברית",
volume = "7",
pages = "20--22",
journal = "בריאות מהשטח: הבטאון לבריאות הסביבה והמזון",
issn = "0793-3444",

}

הצעה לתקן ישראלי לבקרה על שמנים ושומנים אורגניים

פרידלר ע, חואניקו מ. הצעה לתקן ישראלי לבקרה על שמנים ושומנים אורגניים. בריאות מהשטח: הבטאון לבריאות הסביבה והמזון. 1999;7:28-30.
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title = "הצעה לתקן ישראלי לבקרה על שמנים ושומנים אורגניים",
author = "ערן פרידלר and מרסלו חואניקו",
year = "1999",
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journal = "בריאות מהשטח: הבטאון לבריאות הסביבה והמזון",
issn = "0793-3444",

}

ריכוזים אופייניים של שמנים ושומנים בשפכים ביתיים ועירוניים

פרידלר ע, חואניקו מ. ריכוזים אופייניים של שמנים ושומנים בשפכים ביתיים ועירוניים. בריאות מהשטח: הבטאון לבריאות הסביבה והמזון. 1999;7:23-24.
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title = "ריכוזים אופייניים של שמנים ושומנים בשפכים ביתיים ועירוניים",
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journal = "בריאות מהשטח: הבטאון לבריאות הסביבה והמזון",
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}

שמנים ושומנים בשפכים בעסקים הקשורים למזון

פרידלר ע, חואניקו מ. שמנים ושומנים בשפכים בעסקים הקשורים למזון. בריאות מהשטח: הבטאון לבריאות הסביבה והמזון. 1999;7:25-27.
@article{8e597f26623143639e4be44f7a2deac5,
title = "שמנים ושומנים בשפכים בעסקים הקשורים למזון",
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issn = "0793-3444",

}

1998

Enhancing nitrification in vertical flow constructed wetland utilizing a passive air pump

Green M, Friedler E, Safrai I. Enhancing nitrification in vertical flow constructed wetland utilizing a passive air pump. Water Research. 1998 Dec;32(12):3513-3520. https://doi.org/10.1016/S0043-1354(98)00182-1
 

Nitrification of simulated secondary effluent solution using a variant of the vertical how bed constructed wetland was studied. In this system oxygen required for the nitrification process is supplied by a passive air pump. The passive air pump is based on a fill and draw cycle, where oxygen depleted air is removed from the system while fresh air is introduced. Each volume of effluent drained is displaced by an equal volume of fresh air. Spatial and temporal oxygen distribution in the system as a function of drained effluent volume was investigated. Experimental results of nitrification and the corresponding oxygen consumption show good agreement with theoretical calculations based on physicochemical considerations. Observations show that while oxygen distribution within the media was found to be non-uniform at the beginning of each cycle, it approached more uniform distribution with time. The latter resulted mainly from diffusion of oxygen in the gaseous phase.

@article{f5ac6981317c44788c582e6948c72636,
title = "Enhancing nitrification in vertical flow constructed wetland utilizing a passive air pump",
abstract = "Nitrification of simulated secondary effluent solution using a variant of the vertical how bed constructed wetland was studied. In this system oxygen required for the nitrification process is supplied by a passive air pump. The passive air pump is based on a fill and draw cycle, where oxygen depleted air is removed from the system while fresh air is introduced. Each volume of effluent drained is displaced by an equal volume of fresh air. Spatial and temporal oxygen distribution in the system as a function of drained effluent volume was investigated. Experimental results of nitrification and the corresponding oxygen consumption show good agreement with theoretical calculations based on physicochemical considerations. Observations show that while oxygen distribution within the media was found to be non-uniform at the beginning of each cycle, it approached more uniform distribution with time. The latter resulted mainly from diffusion of oxygen in the gaseous phase.",
keywords = "Constructed wetlands, Nitrification, Oxygen balance, Oxygen distribution, Vertical bed",
author = "Michal Green and Eran Friedler and Iris Safrai",
year = "1998",
month = dec,
doi = "10.1016/S0043-1354(98)00182-1",
language = "אנגלית",
volume = "32",
pages = "3513--3520",
journal = "Water Research",
issn = "0043-1354",
publisher = "Elsevier Ltd.",
number = "12",

}

1997

Investigation of alternative method for nitrification in constructed wetlands

Green M, Friedler E, Ruskol Y, Safrai I. Investigation of alternative method for nitrification in constructed wetlands. Water Science and Technology. 1997;35(5):63-70. https://doi.org/10.1016/S0273-1223(97)00053-X
 

Nitrification of secondary effluent using a variant of the vertical flow bed system was investigated. In this vertical flow bed oxygen required for the nitrification process is supplied by a passive air pump. The passive air pump is based on a fill and draw cycle, where oxygen depleted air is removed from the system and fresh air is introduced. Each volume of effluent drained is displaced by an equal volume of fresh air. Experimental results of nitrification and the corresponding oxygen consumption show good agreement with theoretical calculations based on physico-chemical considerations.

@article{6093649dd649443faf7ea16e1f2cd44d,
title = "Investigation of alternative method for nitrification in constructed wetlands",
abstract = "Nitrification of secondary effluent using a variant of the vertical flow bed system was investigated. In this vertical flow bed oxygen required for the nitrification process is supplied by a passive air pump. The passive air pump is based on a fill and draw cycle, where oxygen depleted air is removed from the system and fresh air is introduced. Each volume of effluent drained is displaced by an equal volume of fresh air. Experimental results of nitrification and the corresponding oxygen consumption show good agreement with theoretical calculations based on physico-chemical considerations.",
keywords = "Constructed wetlands, Nitrification, Oxygen balance, Vertical bed",
author = "Michal Green and Eran Friedler and Yuri Ruskol and Iris Safrai",
year = "1997",
doi = "10.1016/S0273-1223(97)00053-X",
language = "אנגלית",
volume = "35",
pages = "63--70",
journal = "Water Science and Technology",
issn = "0273-1223",
publisher = "IWA Publishing",
number = "5",

}

1996

Domestic WC usage patterns

Friedler E, Butler D, Brown DM. Domestic WC usage patterns. Building and Environment. 1996 Jul;31(4):385-392. https://doi.org/10.1016/0360-1323(96)00008-X
 

Despite contributing 30-40% of the total wastewater flow to building drainage systems, little is currently known concerning the detailed usage patterns of the domestic WC. A diary survey of WC usage was carried out on 135 households in southern England over seven consecutive days. Usage was categorised as urine only, faeces only, combined urine and faeces, and other. The urine mode of use followed the expected bimodal pattern of morning and evening peaks, whilst the the number of faecal related flushes peaked only in the morning with no corresponding evening rise. Weekend patterns were shown to differ from week-day usage, particularly in terms of the timing and magnitude of the morning peak. Females were found to use the WC 17% more often than males, whilst males use it 7% more in faecal related mode. Differences were also established between age groups with elderly people apparently having the highest WC usage. The application of cleaning agents was also shown to follow a distinctive diurnal pattern.

@article{ad2ca10dcd204a3399af03a053961086,
title = "Domestic WC usage patterns",
abstract = "Despite contributing 30-40% of the total wastewater flow to building drainage systems, little is currently known concerning the detailed usage patterns of the domestic WC. A diary survey of WC usage was carried out on 135 households in southern England over seven consecutive days. Usage was categorised as urine only, faeces only, combined urine and faeces, and other. The urine mode of use followed the expected bimodal pattern of morning and evening peaks, whilst the the number of faecal related flushes peaked only in the morning with no corresponding evening rise. Weekend patterns were shown to differ from week-day usage, particularly in terms of the timing and magnitude of the morning peak. Females were found to use the WC 17% more often than males, whilst males use it 7% more in faecal related mode. Differences were also established between age groups with elderly people apparently having the highest WC usage. The application of cleaning agents was also shown to follow a distinctive diurnal pattern.",
author = "Eran Friedler and David Butler and Brown, {David M.}",
note = "Funding Information: Acknowlednementa-DMB wishes to acknowledee financial SUD-port from the Postgraduate Training Partnership Award funded by EPSRC. WRc and the Deaartment of Trade and Industrv. E-F wishes to thank the B{\textquoteright}nai-B{\textquoteright}rith Leo-Baek organisation for their financial support. The authors would like to thank all those who gave willingly of their time to participate in the survey.",
year = "1996",
month = jul,
doi = "10.1016/0360-1323(96)00008-X",
language = "אנגלית",
volume = "31",
pages = "385--392",
journal = "Building and Environment",
issn = "0360-1323",
publisher = "Elsevier BV",
number = "4",

}

A study of WC derived sewer solids

Friedler E, Brown DM, Butler D. A study of WC derived sewer solids. Water Science and Technology. 1996;33(9):17-24. https://doi.org/10.1016/0273-1223(96)00365-4
 

Little is currently known about the nature, quantity or variability of WC derived sewer solids. This work describes results of a one week domestic WC usage survey in the UK. Specific attention is paid to solid production including faecal matter, toilet paper and sanitary refuse. Significant quantities of solids were found to be produced. The results illustrate distinctive diurnal usage patterns including the surprisingly low evening faecal related flush usage. Weekend usage exceeded week day usage on average, but with reduced morning peaks. Differences between males and females usage were also noted, in particular the much larger toilet paper usage and sanitary refuse disposal associated with females.

@article{ff69f25cea2747d6b41766d810c4d487,
title = "A study of WC derived sewer solids",
abstract = "Little is currently known about the nature, quantity or variability of WC derived sewer solids. This work describes results of a one week domestic WC usage survey in the UK. Specific attention is paid to solid production including faecal matter, toilet paper and sanitary refuse. Significant quantities of solids were found to be produced. The results illustrate distinctive diurnal usage patterns including the surprisingly low evening faecal related flush usage. Weekend usage exceeded week day usage on average, but with reduced morning peaks. Differences between males and females usage were also noted, in particular the much larger toilet paper usage and sanitary refuse disposal associated with females.",
keywords = "Blackwater, Domestic wastewater, Faeces, Gross solids, Sanitary refuse, Toilet paper, WC",
author = "Eran Friedler and Brown, {David M.} and David Butler",
note = "Funding Information: One of us (DMB) wishes to acknowledge financial support from the Postgraduate Training Partnership Award funded by EPSRC, WRc and the Department of Trade and Industry. The authors would like to thank all those who gave willing of their time to participate in the survey.; Proceedings of the 1995 IAWQ International Specialized Conference on Sewer Solids - Characteristics, Movement, Effects and Control ; Conference date: 06-09-1995 Through 08-09-1995",
year = "1996",
doi = "10.1016/0273-1223(96)00365-4",
language = "אנגלית",
volume = "33",
pages = "17--24",
journal = "Water Science and Technology",
issn = "0273-1223",
publisher = "IWA Publishing",
number = "9",

}

Quantifying the inherent uncertainty in the quantity and quality of domestic wastewater

Friedler E, Butler D. Quantifying the inherent uncertainty in the quantity and quality of domestic wastewater. Water Science and Technology. 1996;33(2):65-75. https://doi.org/10.1016/0273-1223(96)00190-4
 

Results from two surveys in S.E. England are used to illustrate and quantify the inherent uncertainty in the quantity and quality of domestic wastewater at the fundamental level of discharges from domestic appliances. The uncertainties in three principal areas are elucidated. Volumetric discharges are shown to vary significantly for several appliances particularly when used in 'running to waste' mode. Pollutant load also varies and information is presented for a number of different appliance-pollutant combinations. The frequency of use is known to vary throughout the day, but figures are presented to quantify the extent of the spread of the data during each hour of the day. A means of integrating the various elements of uncertainty is proposed. Quantification should enable better control of treatment plants and improve forecasting of the influence of combined sewer overflows on receiving waters, hence enhancing the management of the associated risk.

@article{d8812d522dcf4b0cae8c57f297c11ee8,
title = "Quantifying the inherent uncertainty in the quantity and quality of domestic wastewater",
abstract = "Results from two surveys in S.E. England are used to illustrate and quantify the inherent uncertainty in the quantity and quality of domestic wastewater at the fundamental level of discharges from domestic appliances. The uncertainties in three principal areas are elucidated. Volumetric discharges are shown to vary significantly for several appliances particularly when used in 'running to waste' mode. Pollutant load also varies and information is presented for a number of different appliance-pollutant combinations. The frequency of use is known to vary throughout the day, but figures are presented to quantify the extent of the spread of the data during each hour of the day. A means of integrating the various elements of uncertainty is proposed. Quantification should enable better control of treatment plants and improve forecasting of the influence of combined sewer overflows on receiving waters, hence enhancing the management of the associated risk.",
keywords = "Quality, Quantity, Uncertainty, Variability, Wastewater",
author = "Eran Friedler and David Butler",
year = "1996",
doi = "10.1016/0273-1223(96)00190-4",
language = "אנגלית",
volume = "33",
pages = "65--75",
journal = "Water Science and Technology",
issn = "0273-1223",
publisher = "IWA Publishing",
number = "2",
note = "Proceedings of the 1995 IAWQ Interdisciplinary Symposium on Uncertainty, Risk and Transient Pollution Events ; Conference date: 26-07-1995 Through 28-07-1995",

}

Treatment and storage of wastewater for agricultural irrigation

Friedler E, Juanico M. Treatment and storage of wastewater for agricultural irrigation. International Water and Irrigation. 1996;16(4):26-30.
 

Selection of appropriate technology for municipal sewage treatment and disposal not only requires characterization of the quality of the sewage, but also analysis of the effects that the treated wastewater might have on the agricultural needs and on the environment. To enable the use of treated wastewater for irrigation, it has to comply with sanitary, agrotechnic and environmental quality requirements, which do not always coincide. The primary sanitary needs are low levels of pathogens. The basic agrotechnic requirements are low salts, and storage capacity for regulating between sewage production and effluent demands for irrigation. The environmental needs are low concentration of heavy metals and xenobiotics, controlled level of nutrients and prevention of malodors. A proper combination for achieving these goals may include semi-intensive reactors for partial BOD removal, followed by extensive units for removal of refractory pollutants, pathogens and remaining BOD and providing needed storage capacity.

@misc{b3150a40e7694952b060095c0be03c73,
title = "Treatment and storage of wastewater for agricultural irrigation",
abstract = "Selection of appropriate technology for municipal sewage treatment and disposal not only requires characterization of the quality of the sewage, but also analysis of the effects that the treated wastewater might have on the agricultural needs and on the environment. To enable the use of treated wastewater for irrigation, it has to comply with sanitary, agrotechnic and environmental quality requirements, which do not always coincide. The primary sanitary needs are low levels of pathogens. The basic agrotechnic requirements are low salts, and storage capacity for regulating between sewage production and effluent demands for irrigation. The environmental needs are low concentration of heavy metals and xenobiotics, controlled level of nutrients and prevention of malodors. A proper combination for achieving these goals may include semi-intensive reactors for partial BOD removal, followed by extensive units for removal of refractory pollutants, pathogens and remaining BOD and providing needed storage capacity.",
author = "Eran Friedler and Marcelo Juanico",
year = "1996",
language = "אנגלית",
volume = "16",
pages = "26--30",
journal = "International Water and Irrigation",
issn = "0334-5807",
publisher = "SNER Communications Ltd.",

}

1995

Characterising the quantity and quality of domestic wastewater inflows

Butler D, Friedler E, Gatt K. Characterising the quantity and quality of domestic wastewater inflows. Water Science and Technology. 1995;31(7):13-24. https://doi.org/10.1016/0273-1223(95)00318-H
 

A major source of inflow into sewer networks derives from domestic (sanitary) wastewater. The wastewater is made up of contributions from the various household appliances, influencing both flow quantity and quality. The results from two appliance usage surveys are presented to give detailed insight into the sub-daily variations of flow (quantity) and the relative importance of each appliance throughout the day. The most significant wastewater generating appliance is shown to be the WC, with the least contribution coming from the wash-basin.To establish at-source quality and its variation, limited published information was analysed in conjunction with the survey data The contribution of each appliance to a wastewater pollutant concentration is a combination of both the appliance flow rate and pollutant load, the proportions of which vary throughout the day. Pollutagraphs were produced for BOD, ortho-phosphate, ammonia and nitrate. The WC was found to be a major contributor to all four pollutants and in particular to ammonia. The washing machine was a significant contributor to orthophosphate and nitrate and the wash-basin to ortho-phosphate. Inflow pollutant concentrations were of comparable magnitude to published treatment plant data, although BOD values were found to be higher than expected

@article{b49ac97c5a744df2989a0d84ad749ef9,
title = "Characterising the quantity and quality of domestic wastewater inflows",
abstract = "A major source of inflow into sewer networks derives from domestic (sanitary) wastewater. The wastewater is made up of contributions from the various household appliances, influencing both flow quantity and quality. The results from two appliance usage surveys are presented to give detailed insight into the sub-daily variations of flow (quantity) and the relative importance of each appliance throughout the day. The most significant wastewater generating appliance is shown to be the WC, with the least contribution coming from the wash-basin.To establish at-source quality and its variation, limited published information was analysed in conjunction with the survey data The contribution of each appliance to a wastewater pollutant concentration is a combination of both the appliance flow rate and pollutant load, the proportions of which vary throughout the day. Pollutagraphs were produced for BOD, ortho-phosphate, ammonia and nitrate. The WC was found to be a major contributor to all four pollutants and in particular to ammonia. The washing machine was a significant contributor to orthophosphate and nitrate and the wash-basin to ortho-phosphate. Inflow pollutant concentrations were of comparable magnitude to published treatment plant data, although BOD values were found to be higher than expected",
keywords = "Domestic wastewater, flow quality, flow quantity, per capita daily discharges, sanitary appliances",
author = "David Butler and Eran Friedler and Kevin Gatt",
note = "Funding Information: The work described in this paper forms part of a project funded by the UK Institution of Civil Engineers' R&D Fund and the ConstruC<tion Directorate of the UK Department of the Environment (Contract PECD 7/6/309). One of us (EF) wishes to acknowledge financial support from the Foreign and Commonwealth Office - Clore Foundation and the Royal Society - Israel Academy of Sciences and Humanities. The authors would like to acknowledge Niamh O'Sullivan's contribution to this work.",
year = "1995",
doi = "10.1016/0273-1223(95)00318-H",
language = "אנגלית",
volume = "31",
pages = "13--24",
journal = "Water Science and Technology",
issn = "0273-1223",
publisher = "IWA Publishing",
number = "7",

}

1994

Hydraulic age distribution in perfectly mixed non-steady-state reactors

Juanico M, Friedler E. Hydraulic age distribution in perfectly mixed non-steady-state reactors. Journal of Environmental Engineering (United States). 1994 Nov;120(6):1427-1445. https://doi.org/10.1061/(ASCE)0733-9372(1994)120:6(1427)
 

The Leslie matrix model is applied to the analysis of the hydraulic age distribution of perfectly mixed, non-steady-state flow reactors. The relationship between the hydraulic age distribution and performance of these reactors is discussed, and concepts and algorithms developed in the paper are applied to a case study. Steady-state flow and batch reactors are particular cases of the nonsteady-state flow reactor. The percentage of fresh effluents (PFE) within the reactor is a better descriptor of the reactor performance than the mean residence time. When a reactor is strictly under steady-state flow conditions, the ratio PFE/mean residence time is constant, and only then can the PFE be substituted by the mean residence time. High rate reactions (such as fecal coliforms removal in sewage treatment systems) correlate better with PFE of a few days (1-5 days in the discussed example), and low rate reactions [such as biochemical oxygen demand (BOD) removal] correlate better with the PFE of more days (30 days in the example). Computer algorithms for the calculation of the PFE and mean residence time are provided.

@article{aa9e8a7e26444ee0938c0675826f101e,
title = "Hydraulic age distribution in perfectly mixed non-steady-state reactors",
abstract = "The Leslie matrix model is applied to the analysis of the hydraulic age distribution of perfectly mixed, non-steady-state flow reactors. The relationship between the hydraulic age distribution and performance of these reactors is discussed, and concepts and algorithms developed in the paper are applied to a case study. Steady-state flow and batch reactors are particular cases of the nonsteady-state flow reactor. The percentage of fresh effluents (PFE) within the reactor is a better descriptor of the reactor performance than the mean residence time. When a reactor is strictly under steady-state flow conditions, the ratio PFE/mean residence time is constant, and only then can the PFE be substituted by the mean residence time. High rate reactions (such as fecal coliforms removal in sewage treatment systems) correlate better with PFE of a few days (1-5 days in the discussed example), and low rate reactions [such as biochemical oxygen demand (BOD) removal] correlate better with the PFE of more days (30 days in the example). Computer algorithms for the calculation of the PFE and mean residence time are provided.",
author = "Marcelo Juanico and Eran Friedler",
year = "1994",
month = nov,
doi = "10.1061/(ASCE)0733-9372(1994)120:6(1427)",
language = "אנגלית",
volume = "120",
pages = "1427--1445",
journal = "Journal of Environmental Engineering (United States)",
issn = "0733-9372",
publisher = "American Society of Civil Engineers (ASCE)",
number = "6",

}

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