The planning and design of water networks in water supply systems are primarily based on demand-driven modeling. The prevailing design provisions, such as minimum diameter, lead to oversizing of the water network, affecting operation. In upstream balancing reservoirs, outflow due to the water transmission network's excessive withdrawal capacity surpasses the available inflow causing flow starvation under intermittent water supply. This flow starvation causes partial flow in the downstream vicinity and forms a standing water column in the balancing reservoir's immediate downstream pipe. Traditional modeling approaches cannot simulate the piped network performance under this phenomenon due to their inability to model partial flow. Hence, a novel modeling approach is developed using a tank with an irregular cross-section, which integrates the hydraulic performance of the tank and the downstream pipe. Additionally, a reservoir and control valve represent the water withdrawal mechanism at the downstream reservoir. The proposed modeling approach simulates performance of a flow-starved water transmission network. A case study based on a real network is used to illustrate the robustness of the proposed approach. The developed modeling approach can serve as a management tool to devise operation schedules, helping better manage the operations of the water networks.
{"title":"Hydraulic modeling approach for evaluating the performance of flow-starved water transmission networks","authors":"A. Sinha, A. Ghorpade, O. Damani, P. Kalbar","doi":"10.2166/aqua.2022.024","DOIUrl":"https://doi.org/10.2166/aqua.2022.024","url":null,"abstract":"\u0000 The planning and design of water networks in water supply systems are primarily based on demand-driven modeling. The prevailing design provisions, such as minimum diameter, lead to oversizing of the water network, affecting operation. In upstream balancing reservoirs, outflow due to the water transmission network's excessive withdrawal capacity surpasses the available inflow causing flow starvation under intermittent water supply. This flow starvation causes partial flow in the downstream vicinity and forms a standing water column in the balancing reservoir's immediate downstream pipe. Traditional modeling approaches cannot simulate the piped network performance under this phenomenon due to their inability to model partial flow. Hence, a novel modeling approach is developed using a tank with an irregular cross-section, which integrates the hydraulic performance of the tank and the downstream pipe. Additionally, a reservoir and control valve represent the water withdrawal mechanism at the downstream reservoir. The proposed modeling approach simulates performance of a flow-starved water transmission network. A case study based on a real network is used to illustrate the robustness of the proposed approach. The developed modeling approach can serve as a management tool to devise operation schedules, helping better manage the operations of the water networks.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90331711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Discoloration events in drinking water distribution systems (DWDSs) caused by iron particles have occurred worldwide, and boiling has been applied in drinking water treatment households globally, but the effects of boiling on iron particles are not clear. Here, the effect of boiling on different kinds of iron particles (including loose deposits from the DWDS and their main components FeOOH, Fe2O3, and Fe3O4) was studied. At 10 mg/L, the turbidity values before/after boiling of Fe2O3, Fe3O4, and FeOOH were 134.00/121.00, 25.07/21.22, and 120.40/114.20 NTU, respectively. All the particles had a lower degree of crystallinity after boiling. After boiling, the number of particles in loose deposits increased and the particle size decreased, while iron oxides were on the contrary. Among the three iron oxides, the existence of Fe3O4 and Fe2O3 had different effects on disinfection by-products (DBPs) formation. The activity of microorganisms was the highest under particle concentration of 0.1 mg/L than other concentrations for all the particles, but the total microbiological risks were still very low after boiling. Thus, the boiling treatment would increase the turbidity and risks of the particles. As the particle concentration under low concentration is hard to be found, this risk is hard to be found.
{"title":"Effects of boiling on iron particles in drinking water","authors":"Penglu Li, Y. Zhuang, Baoyou Shi, Kefeng Zhang","doi":"10.2166/aqua.2022.244","DOIUrl":"https://doi.org/10.2166/aqua.2022.244","url":null,"abstract":"\u0000 Discoloration events in drinking water distribution systems (DWDSs) caused by iron particles have occurred worldwide, and boiling has been applied in drinking water treatment households globally, but the effects of boiling on iron particles are not clear. Here, the effect of boiling on different kinds of iron particles (including loose deposits from the DWDS and their main components FeOOH, Fe2O3, and Fe3O4) was studied. At 10 mg/L, the turbidity values before/after boiling of Fe2O3, Fe3O4, and FeOOH were 134.00/121.00, 25.07/21.22, and 120.40/114.20 NTU, respectively. All the particles had a lower degree of crystallinity after boiling. After boiling, the number of particles in loose deposits increased and the particle size decreased, while iron oxides were on the contrary. Among the three iron oxides, the existence of Fe3O4 and Fe2O3 had different effects on disinfection by-products (DBPs) formation. The activity of microorganisms was the highest under particle concentration of 0.1 mg/L than other concentrations for all the particles, but the total microbiological risks were still very low after boiling. Thus, the boiling treatment would increase the turbidity and risks of the particles. As the particle concentration under low concentration is hard to be found, this risk is hard to be found.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73640961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the current study, an alternative precursor for the production of activated carbon (AC) is introduced using grape wood. The AC structures and functional groups were studied using a scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). The efficiency of prepared AC has been investigated in the removal of Reactive Red 2 (RR2) from an aqueous solution. The effect of main variables, namely dye concentration (100–500 mg L−1), contact time (10–90 min), adsorbent dosage (0.25–12.25 g L−1), and initial pH (3–11) have been assessed on the adsorption process in order to find out the optimum conditions. Langmuir, Freundlich, and Temkin adsorption isotherm models were applied to describe the characteristics of adsorption behavior. Kinetic data were fitted to pseudo-first-order, pseudo-second-order, and intra-particle diffusion models. Based on the results, the highest removal efficiency (97.96%) of RR2 dye was obtained at an initial concentration of 100 mg L−1, adsorbent dose of 12.25 g, contact time of 90 min, and pH 3, which indicated a significant sorption efficiency. The rate of the adsorption fitted well to a pseudo-second-order kinetic model (R2 = 0.99). In addition, the Temkin adsorption isotherm model was found to fit the experimental data (R2 = 0.99).
{"title":"Kinetic and isotherm studies on the removal of reactive Red 2 from aqueous solutions using phosphoric acid activated carbon","authors":"Arezoo Mahmoudi, S. Mousavi, S. Atashkar","doi":"10.2166/aqua.2022.125","DOIUrl":"https://doi.org/10.2166/aqua.2022.125","url":null,"abstract":"\u0000 In the current study, an alternative precursor for the production of activated carbon (AC) is introduced using grape wood. The AC structures and functional groups were studied using a scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). The efficiency of prepared AC has been investigated in the removal of Reactive Red 2 (RR2) from an aqueous solution. The effect of main variables, namely dye concentration (100–500 mg L−1), contact time (10–90 min), adsorbent dosage (0.25–12.25 g L−1), and initial pH (3–11) have been assessed on the adsorption process in order to find out the optimum conditions. Langmuir, Freundlich, and Temkin adsorption isotherm models were applied to describe the characteristics of adsorption behavior. Kinetic data were fitted to pseudo-first-order, pseudo-second-order, and intra-particle diffusion models. Based on the results, the highest removal efficiency (97.96%) of RR2 dye was obtained at an initial concentration of 100 mg L−1, adsorbent dose of 12.25 g, contact time of 90 min, and pH 3, which indicated a significant sorption efficiency. The rate of the adsorption fitted well to a pseudo-second-order kinetic model (R2 = 0.99). In addition, the Temkin adsorption isotherm model was found to fit the experimental data (R2 = 0.99).","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89272902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study examines key factors influencing the economic benefit of rainwater harvesting on the household at the Mongla Upazila in the Bagerhat district of coastal Bangladesh. The household survey questionnaire was used to collect primary data from 1040 households. The Ordinary Least Square (OLS) regression analysis was applied to understand the relationship between economic benefit and factors that can affect economic benefit in the household. The empirical result shows that income (1.103**), storage capacity (0.574***), water price (32708.9***), age of rainwater harvesting (100.083***), and total cost (1.627***) positively impact economic benefit while the number of children (35.531**) has a negative relationship. The finding confirms the validity of statistical hypotheses. In addition, heterogeneity analysis was employed to test the model's strength and robustness check to validate the structural function and efficiency of the regression model. The finding concludes with policy recommendations, especially for rain-intensive countries that focus on (i) formulating and implementing rainwater harvesting policy; (ii) integrating rainwater harvesting as a tool for poverty reduction and achieving sustainable development goals; (iii) minimizing mismanagement of (rain) water that causes floods; (iv) initiate programme and take necessary steps for providing financial and non-financial incentive for rainwater harvesting in commercial, and non-commercial building.
{"title":"Factors influencing economic benefit of rainwater harvesting: an empirical analysis","authors":"M. R. Islam","doi":"10.2166/aqua.2022.040","DOIUrl":"https://doi.org/10.2166/aqua.2022.040","url":null,"abstract":"\u0000 This study examines key factors influencing the economic benefit of rainwater harvesting on the household at the Mongla Upazila in the Bagerhat district of coastal Bangladesh. The household survey questionnaire was used to collect primary data from 1040 households. The Ordinary Least Square (OLS) regression analysis was applied to understand the relationship between economic benefit and factors that can affect economic benefit in the household. The empirical result shows that income (1.103**), storage capacity (0.574***), water price (32708.9***), age of rainwater harvesting (100.083***), and total cost (1.627***) positively impact economic benefit while the number of children (35.531**) has a negative relationship. The finding confirms the validity of statistical hypotheses. In addition, heterogeneity analysis was employed to test the model's strength and robustness check to validate the structural function and efficiency of the regression model. The finding concludes with policy recommendations, especially for rain-intensive countries that focus on (i) formulating and implementing rainwater harvesting policy; (ii) integrating rainwater harvesting as a tool for poverty reduction and achieving sustainable development goals; (iii) minimizing mismanagement of (rain) water that causes floods; (iv) initiate programme and take necessary steps for providing financial and non-financial incentive for rainwater harvesting in commercial, and non-commercial building.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86963676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A novel copolymer was used as an adsorbent for enhanced ammonium removal in an aqueous system; different ratios of styrene–acrylic acid copolymers were synthesized by random free radical polymerization and followed by a sulfonation of styrene (acrylic acid 25%–sulfonated styrene 75%) copolymer [P(AA25/SS75)] attained the highest ammonium adsorption capacity (55.8 mg/g) due to the electrostatic attraction between positively charged NH4+ and negatively charged –COO− and –SO3- groups. FTIR spectra for sulfonated polymers illustrated the appearance of characteristic peaks at 100–1,200 cm−1 indicating that the copolymers were successfully sulfonated. The influence of different experimental factors (i.e., contact time, pH, NH4+ concentration, adsorbent dose) on ammonium ion adsorption was investigated; three adsorption isotherm models including Langmuir, Freundlich, and Temkin were used to study the adsorption mechanism. The results indicated that the equilibrium of adsorption can be reached within 30 min; the highest adsorption capacity can be achieved around pH 7. Furthermore, Freundlich isotherm was the most suitable for fitting the experimental data which might expose the heterogeneity of the adsorbent surface. The regeneration and reusability studies were also implemented, and results showed that P(AA25/PSS75) was stable and regenerable using (1 M) sulfuric acid as a desorbing agent over five cycles.
{"title":"Enhanced ammonium removal from aquatic systems by a novel copolymer","authors":"Waseem A. Gad, Hazem F. Taha, Ibrahim El-Hussein","doi":"10.2166/aqua.2022.075","DOIUrl":"https://doi.org/10.2166/aqua.2022.075","url":null,"abstract":"\u0000 A novel copolymer was used as an adsorbent for enhanced ammonium removal in an aqueous system; different ratios of styrene–acrylic acid copolymers were synthesized by random free radical polymerization and followed by a sulfonation of styrene (acrylic acid 25%–sulfonated styrene 75%) copolymer [P(AA25/SS75)] attained the highest ammonium adsorption capacity (55.8 mg/g) due to the electrostatic attraction between positively charged NH4+ and negatively charged –COO− and –SO3- groups. FTIR spectra for sulfonated polymers illustrated the appearance of characteristic peaks at 100–1,200 cm−1 indicating that the copolymers were successfully sulfonated. The influence of different experimental factors (i.e., contact time, pH, NH4+ concentration, adsorbent dose) on ammonium ion adsorption was investigated; three adsorption isotherm models including Langmuir, Freundlich, and Temkin were used to study the adsorption mechanism. The results indicated that the equilibrium of adsorption can be reached within 30 min; the highest adsorption capacity can be achieved around pH 7. Furthermore, Freundlich isotherm was the most suitable for fitting the experimental data which might expose the heterogeneity of the adsorbent surface. The regeneration and reusability studies were also implemented, and results showed that P(AA25/PSS75) was stable and regenerable using (1 M) sulfuric acid as a desorbing agent over five cycles.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85642398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Developing solutions for lake eutrophication has emerged as a priority area to address the loss of ecosystem balance, reduction in aquatic biodiversity, and the potential production of toxins. Floating bed solutions offer an effective methodology to address this issue. This study uses rice straw as a base for floating bed treatment. Treatment of simulated eutrophic water was analyzed with and without plants in combination with rice straw beds (RS and RS + P). Treatment efficiency was also tested under increased aeration conditions (RS + A). Results demonstrated that average removal efficiencies of the ecological beds assembled with plant and aerator ranged from 81 to 82%, 80 to 85%, 78 to 86%, 61 to 69% for COD, NH4+-N, NO3−-N, and phosphates, respectively. The microbial community structure was also analyzed from the water samples taken from ecological beds assembled with plant and aerator by 16S rRNA gene sequencing. Based on the above results, systems assembled with plants and aerators proved to be efficient for the treatment of eutrophic water.
{"title":"Designing efficient floating bed options for the treatment of eutrophic water","authors":"Sampurna Nandy, D. Kalra, A. Kapley","doi":"10.2166/aqua.2022.100","DOIUrl":"https://doi.org/10.2166/aqua.2022.100","url":null,"abstract":"\u0000 Developing solutions for lake eutrophication has emerged as a priority area to address the loss of ecosystem balance, reduction in aquatic biodiversity, and the potential production of toxins. Floating bed solutions offer an effective methodology to address this issue. This study uses rice straw as a base for floating bed treatment. Treatment of simulated eutrophic water was analyzed with and without plants in combination with rice straw beds (RS and RS + P). Treatment efficiency was also tested under increased aeration conditions (RS + A). Results demonstrated that average removal efficiencies of the ecological beds assembled with plant and aerator ranged from 81 to 82%, 80 to 85%, 78 to 86%, 61 to 69% for COD, NH4+-N, NO3−-N, and phosphates, respectively. The microbial community structure was also analyzed from the water samples taken from ecological beds assembled with plant and aerator by 16S rRNA gene sequencing. Based on the above results, systems assembled with plants and aerators proved to be efficient for the treatment of eutrophic water.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91402126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Niraj S. Topare, Anish Khan, S. V. Khedkar, Shantini A. Bokil
One of the most important problems that the world is currently facing in terms of its impact on the environment is figuring out how to properly manage textile effluents. Photocatalysis has been shown to be successful in the removal of intractable chemicals and is regarded as a viable wastewater treatment technology. This work focused on the photocatalytic degradation of rhodamine-B (RB) in an aqueous solution, as well as the photocatalytic behavior of niobium pentaoxide (Nb2O5) as a photocatalyst was tested. It is important to note that good photocatalytic efficiency is highly dependent on the operating conditions. There are several process parameters that influence RB photocatalytic degradation, including the amount of photocatalyst (Nb2O5) used, the concentration of RB at the start of the reaction, and the pH of the solution optimized under visible-light irradiation. According to the findings, the conditions in which the greatest amount of RB was degraded were those in which the concentration of the catalyst was 10 mg/l, the dosage of the catalyst was 1 mg/l, and the pH was 11. The results also revealed that after utilizing the catalyst three times in a row, catalyst efficiency was maintained, and the degradation rate was maintained at a greater level.
就其对环境的影响而言，世界目前面临的最重要的问题之一是弄清楚如何妥善管理纺织废水。光催化已被证明在去除难处理化学物质方面是成功的，被认为是一种可行的废水处理技术。本文主要研究了罗丹明- b (RB)在水溶液中的光催化降解，并测试了五氧化铌(Nb2O5)作为光催化剂的光催化行为。值得注意的是，良好的光催化效率高度依赖于操作条件。影响RB光催化降解的工艺参数有几个，包括光催化剂(Nb2O5)用量、反应开始时RB的浓度以及可见光照射下优化的溶液pH。结果表明，催化剂浓度为10 mg/l，催化剂投加量为1 mg/l, pH为11时，RB降解量最大。结果还表明，连续三次使用催化剂后，催化剂效率保持不变，降解率保持在较高水平。
{"title":"Niobium pentaoxide (Nb2O5) as an efficient photocatalyst for photocatalytic degradation of rhodamine-B","authors":"Niraj S. Topare, Anish Khan, S. V. Khedkar, Shantini A. Bokil","doi":"10.2166/aqua.2022.218","DOIUrl":"https://doi.org/10.2166/aqua.2022.218","url":null,"abstract":"\u0000 One of the most important problems that the world is currently facing in terms of its impact on the environment is figuring out how to properly manage textile effluents. Photocatalysis has been shown to be successful in the removal of intractable chemicals and is regarded as a viable wastewater treatment technology. This work focused on the photocatalytic degradation of rhodamine-B (RB) in an aqueous solution, as well as the photocatalytic behavior of niobium pentaoxide (Nb2O5) as a photocatalyst was tested. It is important to note that good photocatalytic efficiency is highly dependent on the operating conditions. There are several process parameters that influence RB photocatalytic degradation, including the amount of photocatalyst (Nb2O5) used, the concentration of RB at the start of the reaction, and the pH of the solution optimized under visible-light irradiation. According to the findings, the conditions in which the greatest amount of RB was degraded were those in which the concentration of the catalyst was 10 mg/l, the dosage of the catalyst was 1 mg/l, and the pH was 11. The results also revealed that after utilizing the catalyst three times in a row, catalyst efficiency was maintained, and the degradation rate was maintained at a greater level.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90983969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Household water consumption plays an important role in addressing the problem of water shortage and achieving sustainable water development. To identify, assess, and analyze the impact of a family structure on household water consumption, this study develops a mathematical statistical method to conduct multi-scenario simulations of average annual household water consumption based on data from the 2016 China Family Panel Studies (CFPS). The Kolmogorov–Smirnov test and the two independent sample t-tests were used to obtain the distribution with the highest degree of fitting, and the probability distribution and expected value of average annual household water consumption were obtained from the distribution probability function. The results demonstrated that the Birnbaum–Saunders distribution was the optimal distribution; families comprising one and two generations were dominant in terms of water consumption; and the number of water-saving households was far less than that of households with high levels of water consumption. The findings of this study have valuable implications for water governance and policy optimization.
{"title":"Modeling the impact of a family structure on household water consumption","authors":"Mei Wang, Hanliang Fu, Xinfa Zhou, Zhe Cheng","doi":"10.2166/aqua.2022.166","DOIUrl":"https://doi.org/10.2166/aqua.2022.166","url":null,"abstract":"\u0000 Household water consumption plays an important role in addressing the problem of water shortage and achieving sustainable water development. To identify, assess, and analyze the impact of a family structure on household water consumption, this study develops a mathematical statistical method to conduct multi-scenario simulations of average annual household water consumption based on data from the 2016 China Family Panel Studies (CFPS). The Kolmogorov–Smirnov test and the two independent sample t-tests were used to obtain the distribution with the highest degree of fitting, and the probability distribution and expected value of average annual household water consumption were obtained from the distribution probability function. The results demonstrated that the Birnbaum–Saunders distribution was the optimal distribution; families comprising one and two generations were dominant in terms of water consumption; and the number of water-saving households was far less than that of households with high levels of water consumption. The findings of this study have valuable implications for water governance and policy optimization.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76009129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Water quality simulation is affected by uncertain parameters such as pipe roughness coefficients, chlorine bulk decay coefficients, and chlorine wall decay coefficients, which are usually considered to be fuzzy variables. The minimum and maximum nodal chlorine concentrations and water ages at each α-cut level were obtained by the genetic algorithm (GA) based on EPANET hydraulic and water quality simulation toolkit. The fuzziness of nodal chlorine concentrations and water ages were measured using the fuzziness measure (FM) proposed in this paper. The method was applied to four networks to analyze the fuzziness of nodal chlorine concentrations and water ages. The results indicated that the distribution of nodal chlorine concentrations does not follow typical trapezoid distribution, while the distribution of nodal water ages follows typical trapezoid distribution. In addition, the chlorine concentration and water ages of nodes farther from the source are affected by uncertain parameters to a greater extent. The greater demands of nodes lead to less effects of uncertain parameters on chlorine concentration, and greater effects of uncertain parameters on water ages. This study would help in analyzing the fuzziness of hydraulic and water quality simulation results in WDS under uncertain conditions.
{"title":"Uncertainty analysis of water quality in water distribution system","authors":"Xiaolu Xiong, Yumin Wang","doi":"10.2166/aqua.2022.267","DOIUrl":"https://doi.org/10.2166/aqua.2022.267","url":null,"abstract":"\u0000 Water quality simulation is affected by uncertain parameters such as pipe roughness coefficients, chlorine bulk decay coefficients, and chlorine wall decay coefficients, which are usually considered to be fuzzy variables. The minimum and maximum nodal chlorine concentrations and water ages at each α-cut level were obtained by the genetic algorithm (GA) based on EPANET hydraulic and water quality simulation toolkit. The fuzziness of nodal chlorine concentrations and water ages were measured using the fuzziness measure (FM) proposed in this paper. The method was applied to four networks to analyze the fuzziness of nodal chlorine concentrations and water ages. The results indicated that the distribution of nodal chlorine concentrations does not follow typical trapezoid distribution, while the distribution of nodal water ages follows typical trapezoid distribution. In addition, the chlorine concentration and water ages of nodes farther from the source are affected by uncertain parameters to a greater extent. The greater demands of nodes lead to less effects of uncertain parameters on chlorine concentration, and greater effects of uncertain parameters on water ages. This study would help in analyzing the fuzziness of hydraulic and water quality simulation results in WDS under uncertain conditions.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84461313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Intermittent water supply (IWS) is a typical characteristic of cities in developing countries like India. One of the factors responsible for IWS is unaccounted for water (UFW). Factors like increase in population, upward trends in water demand, water scarcity due to climate change, and asymmetric distribution of water resources are also equally important. However, social relations of water are poorly understood and camouflaged under technicalities associated with IWS. Thus, in this paper, we examine IWS in Indian mega cities and secondary cities with an ethno-economic framework by bringing the data together from various administrative sources like government agencies, allude to its parameters from logistical perspectives, e.g. distances, capacities, population strength, etc., and try to position the water issue with challenges associated with caste, class, gender, religion, region, and governance. The ethno-economic perspective is an attempt to not only complement but also supplement the scientific studies from other disciplines by understanding the real nature of demand and supply problems in urban water management. This paper demonstrates IWS as a multi-dimensional problem and stresses on the human drivers of intermittency.
{"title":"Intermittent water supply in Indian cities: considering the intermittency beyond demand and supply","authors":"S. Satpathy, R. Jha","doi":"10.2166/aqua.2022.149","DOIUrl":"https://doi.org/10.2166/aqua.2022.149","url":null,"abstract":"\u0000 Intermittent water supply (IWS) is a typical characteristic of cities in developing countries like India. One of the factors responsible for IWS is unaccounted for water (UFW). Factors like increase in population, upward trends in water demand, water scarcity due to climate change, and asymmetric distribution of water resources are also equally important. However, social relations of water are poorly understood and camouflaged under technicalities associated with IWS. Thus, in this paper, we examine IWS in Indian mega cities and secondary cities with an ethno-economic framework by bringing the data together from various administrative sources like government agencies, allude to its parameters from logistical perspectives, e.g. distances, capacities, population strength, etc., and try to position the water issue with challenges associated with caste, class, gender, religion, region, and governance. The ethno-economic perspective is an attempt to not only complement but also supplement the scientific studies from other disciplines by understanding the real nature of demand and supply problems in urban water management. This paper demonstrates IWS as a multi-dimensional problem and stresses on the human drivers of intermittency.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72627754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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