Michail L. Giannitsopoulos, P. Leinster, David C. Butler, Mike Smith, M. Rivas Casado
Preparedness for flood emergency response is crucial for effective flood management. The need for advanced flood decision support tools that aid flood management has been recognized by several authors. This work examines the variability that currently exists across England with regard to the Unmanned Aerial System (UAS) data collection and processing strategy in flood emergency events. Expert elicitation was carried out using a tailored questionnaire about UAS deployment in three flood emergency scenarios. The survey highlighted that reduced equipment assembly time, a national network of appropriately qualified UAS pilots and the effective UAS deployment when on-site, can reduce the response time to flood emergency. For improved comparability and reduced bias in data collection and interpretation, clear guidelines on which data products are most beneficial for particular purposes, processing time required, platform and sensor selection may also be necessary. We consider that releasing a comprehensive documentation pack, which includes guidelines, standards and protocols that detail the methods, tools, technology, quantity and quality of data, to UAS pilots on a flood emergency call, will enhance the timely response.
{"title":"Towards the coordinated and fit-for-purpose deployment of Unmanned Aerial Systems (UASs) for flood risk management in England","authors":"Michail L. Giannitsopoulos, P. Leinster, David C. Butler, Mike Smith, M. Rivas Casado","doi":"10.2166/aqua.2022.101","DOIUrl":"https://doi.org/10.2166/aqua.2022.101","url":null,"abstract":"\u0000 Preparedness for flood emergency response is crucial for effective flood management. The need for advanced flood decision support tools that aid flood management has been recognized by several authors. This work examines the variability that currently exists across England with regard to the Unmanned Aerial System (UAS) data collection and processing strategy in flood emergency events. Expert elicitation was carried out using a tailored questionnaire about UAS deployment in three flood emergency scenarios. The survey highlighted that reduced equipment assembly time, a national network of appropriately qualified UAS pilots and the effective UAS deployment when on-site, can reduce the response time to flood emergency. For improved comparability and reduced bias in data collection and interpretation, clear guidelines on which data products are most beneficial for particular purposes, processing time required, platform and sensor selection may also be necessary. We consider that releasing a comprehensive documentation pack, which includes guidelines, standards and protocols that detail the methods, tools, technology, quantity and quality of data, to UAS pilots on a flood emergency call, will enhance the timely response.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75522150","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}
Ensuring a continuous water supply (CWS) for households is beneficial for the current global drinking water, sanitation, and hygiene agenda. Despite improvements in water supply, intermittent water supply (IWS) remains prevalent in rural areas. To determine the factors that lead to different water supply modes for villages, we select 38 village-level water utilities covered by the Chinese Safe Drinking Water Project for fuzzy set qualitative comparative analysis to identify causal configurations (‘pathways’) that lead to IWS or CWS across systems. Six configurations of water supply mode are identified on the basis of the outcomes of each case. Among these, three configurations for adopting CWS are determined. Configuration 1 features water utility with government subsidy and bills using a water meter. Configuration 2 features water utility with small population coverage, government subsidy, and villager participation in the management. Configuration 3 features a water utility collectively managed and owned by a rich village and water-saving initiatives. Configurations that lack meter-based bills, government subsidies, and water-saving initiatives are the main paths for IWS. Results highlight the uniqueness of the configurational approach in understanding different water supply patterns across various cases and emphasise the importance of government subsidies, villager participation, water-saving programmes, and water meter-based billing to achieve CWS.
{"title":"Identification of pathways that lead to continuous or intermittent water supply by conducting a qualitative comparative analysis of rural water utilities in China","authors":"Yan Tong, Liangxin Fan, Haipeng Niu","doi":"10.2166/aqua.2022.052","DOIUrl":"https://doi.org/10.2166/aqua.2022.052","url":null,"abstract":"Ensuring a continuous water supply (CWS) for households is beneficial for the current global drinking water, sanitation, and hygiene agenda. Despite improvements in water supply, intermittent water supply (IWS) remains prevalent in rural areas. To determine the factors that lead to different water supply modes for villages, we select 38 village-level water utilities covered by the Chinese Safe Drinking Water Project for fuzzy set qualitative comparative analysis to identify causal configurations (‘pathways’) that lead to IWS or CWS across systems. Six configurations of water supply mode are identified on the basis of the outcomes of each case. Among these, three configurations for adopting CWS are determined. Configuration 1 features water utility with government subsidy and bills using a water meter. Configuration 2 features water utility with small population coverage, government subsidy, and villager participation in the management. Configuration 3 features a water utility collectively managed and owned by a rich village and water-saving initiatives. Configurations that lack meter-based bills, government subsidies, and water-saving initiatives are the main paths for IWS. Results highlight the uniqueness of the configurational approach in understanding different water supply patterns across various cases and emphasise the importance of government subsidies, villager participation, water-saving programmes, and water meter-based billing to achieve CWS.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90377262","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}
Bruna Fioramonte, M. A. Campos, S. R. de Freitas, R. Basso
The demand for water has led to an increase in scarcity events in several urban regions. In an urban context, water consumption in buildings plays an important role and rainwater harvesting is one of the ways that consumption can be reduced. One of the input variables for the dimensioning of rainwater tanks is the pluviometric regime's characteristics in the region where the rainwater harvesting system (RWHS) is to be installed. In this study, a bibliometric and systematic literature review was carried out on the types of rainfall data used in the dimensioning of the elements of RWHS. Worldwide, the most-used data comes from meteorological stations, with a historical series size of 30 years, however, other types of data and different sizes of historical series are also used. From this study, it was possible to synthesise the regions where differentiation data can be collected, as well as their characteristics, enabling the researchers to quickly access the definition of separation data collection parameters.
{"title":"Rainfall data used for rainwater harvesting systems: a bibliometric and systematic literature review","authors":"Bruna Fioramonte, M. A. Campos, S. R. de Freitas, R. Basso","doi":"10.2166/aqua.2022.034","DOIUrl":"https://doi.org/10.2166/aqua.2022.034","url":null,"abstract":"\u0000 The demand for water has led to an increase in scarcity events in several urban regions. In an urban context, water consumption in buildings plays an important role and rainwater harvesting is one of the ways that consumption can be reduced. One of the input variables for the dimensioning of rainwater tanks is the pluviometric regime's characteristics in the region where the rainwater harvesting system (RWHS) is to be installed. In this study, a bibliometric and systematic literature review was carried out on the types of rainfall data used in the dimensioning of the elements of RWHS. Worldwide, the most-used data comes from meteorological stations, with a historical series size of 30 years, however, other types of data and different sizes of historical series are also used. From this study, it was possible to synthesise the regions where differentiation data can be collected, as well as their characteristics, enabling the researchers to quickly access the definition of separation data collection parameters.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76982002","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 losses in water distribution systems (WDSs) cause inefficiency of water resources and increase operating costs. Water loss management (WLM) methods generally have high initial investment and operating costs. However, the budget planned within the scope of WLM in administrations is generally limited. Therefore, the most appropriate method should be determined by considering the budget conditions and cost–benefit analysis. The aim of this study is to propose a new economic water loss level (EWLL) model in WDSs with the different budget constraints of 5, 15 and 20% of the annual income. This EWLL model was developed by the discrete stochastic optimization algorithm. The EWLL and economically recoverable leakage volumes were determined by considering the budget constraints. Moreover, the most appropriate methods were determined to reach the EWLL values defined according to the budget constraints. The EWLL was calculated as 8.62% by the optimization model without budget constraints. Moreover, the EWLL values with budget constraints of 5, 15 and 20% of the annual income were determined as 56.82, 21.14 and 18.02%, respectively. This EWLL model will make a significant contribution to the annual planning in WLM depending on the budget constraints of the administrations.
{"title":"Analyzing the economic water loss level with a discrete stochastic optimization algorithm by considering budget constraints","authors":"S. Yilmaz, M. Firat, Abdullah Ateş, Ö. Özdemir","doi":"10.2166/aqua.2022.060","DOIUrl":"https://doi.org/10.2166/aqua.2022.060","url":null,"abstract":"\u0000 Water losses in water distribution systems (WDSs) cause inefficiency of water resources and increase operating costs. Water loss management (WLM) methods generally have high initial investment and operating costs. However, the budget planned within the scope of WLM in administrations is generally limited. Therefore, the most appropriate method should be determined by considering the budget conditions and cost–benefit analysis. The aim of this study is to propose a new economic water loss level (EWLL) model in WDSs with the different budget constraints of 5, 15 and 20% of the annual income. This EWLL model was developed by the discrete stochastic optimization algorithm. The EWLL and economically recoverable leakage volumes were determined by considering the budget constraints. Moreover, the most appropriate methods were determined to reach the EWLL values defined according to the budget constraints. The EWLL was calculated as 8.62% by the optimization model without budget constraints. Moreover, the EWLL values with budget constraints of 5, 15 and 20% of the annual income were determined as 56.82, 21.14 and 18.02%, respectively. This EWLL model will make a significant contribution to the annual planning in WLM depending on the budget constraints of the administrations.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84230342","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}
Simulation and prediction of precipitation time series changes are important for revealing global climate change patterns and understanding surface hydrological processes. However, precipitation is influenced by a variety of factors together, showing the characteristics of nonlinear variation patterns. Given that backpropagation (BP) neural network has a strong mapping ability for nonlinear fitting, we consider using BP neural network for precipitation prediction, then use Sparrow Search Algorithm (SSA) to optimize BP network initial threshold and weight information to improve the efficiency of precipitation prediction. To further enhance model predictive performance, the Markov model is employed to predict the residual series of the SSA-BP model, so as to finally construct a combined SSA-BP-Markov model of precipitation. In this paper, the model is used to simulate the rainfall prediction in Zhengzhou City, Henan Province, China, and to compare and analyze with the other traditional models. The empirical prediction results show that the SSA-BP-Markov model is more accurate and the convergence of the algorithm is better. The model provides a new way of thinking for precipitation prediction and is also useful for predicting precipitation in other regions.
{"title":"A combined model based on sparrow search optimized BP neural network and Markov chain for precipitation prediction in Zhengzhou City, China","authors":"N. Guo, Zhaocai Wang","doi":"10.2166/aqua.2022.047","DOIUrl":"https://doi.org/10.2166/aqua.2022.047","url":null,"abstract":"\u0000 Simulation and prediction of precipitation time series changes are important for revealing global climate change patterns and understanding surface hydrological processes. However, precipitation is influenced by a variety of factors together, showing the characteristics of nonlinear variation patterns. Given that backpropagation (BP) neural network has a strong mapping ability for nonlinear fitting, we consider using BP neural network for precipitation prediction, then use Sparrow Search Algorithm (SSA) to optimize BP network initial threshold and weight information to improve the efficiency of precipitation prediction. To further enhance model predictive performance, the Markov model is employed to predict the residual series of the SSA-BP model, so as to finally construct a combined SSA-BP-Markov model of precipitation. In this paper, the model is used to simulate the rainfall prediction in Zhengzhou City, Henan Province, China, and to compare and analyze with the other traditional models. The empirical prediction results show that the SSA-BP-Markov model is more accurate and the convergence of the algorithm is better. The model provides a new way of thinking for precipitation prediction and is also useful for predicting precipitation in other regions.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75678550","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 three-dimensional (3D) computational fluid dynamics (CFD) approach is developed to elaborate the water-hammer pipe flow and 3D detailed dynamic characteristics of a closing ball valve. The proposed CFD approach considers the water compressibility and the viscous sublayer, which are sometimes neglected in previous studies. Comparisons of the CFD results, the measured pressures and the one-dimensional results, demonstrate that the current 3D CFD approach better reproduces the experimental pressure oscillations while helping to visualize the associated physical processes and to further explore the 3D transient characteristics. The mean velocity distributions in the radial direction significantly change as the pipe transient progresses, which is closely associated with transient shear stress. Mean velocity variations at the valve during the closing process undergo three distinct stages: slight change, then drastic reduction, and finally slowing down. Head loss coefficient and discharge coefficient of the valve change as the valve closing time shortens.
{"title":"3D CFD simulation and analysis of transient flow in a water pipeline","authors":"Yun Cao, Ling Zhou, C. Ou, Haoyu Fang, Deyou Liu","doi":"10.2166/aqua.2022.023","DOIUrl":"https://doi.org/10.2166/aqua.2022.023","url":null,"abstract":"\u0000 A three-dimensional (3D) computational fluid dynamics (CFD) approach is developed to elaborate the water-hammer pipe flow and 3D detailed dynamic characteristics of a closing ball valve. The proposed CFD approach considers the water compressibility and the viscous sublayer, which are sometimes neglected in previous studies. Comparisons of the CFD results, the measured pressures and the one-dimensional results, demonstrate that the current 3D CFD approach better reproduces the experimental pressure oscillations while helping to visualize the associated physical processes and to further explore the 3D transient characteristics. The mean velocity distributions in the radial direction significantly change as the pipe transient progresses, which is closely associated with transient shear stress. Mean velocity variations at the valve during the closing process undergo three distinct stages: slight change, then drastic reduction, and finally slowing down. Head loss coefficient and discharge coefficient of the valve change as the valve closing time shortens.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78338549","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}
Economic and social development have worsened the situation of water pollution and even the ecological environment. It is helpful to quantify the water pollution ecological environment losses for decision-makers to formulate reasonable pollution control plans. However, the current quantitative analyses led by economic methods are not comprehensive and systematic. Therefore, based on the emergy theory and method system of eco-economics, this study analyzed the internal energy flow process of the water-polluted ecosystem, discussed the composition of water-polluted ecological environment loss, and proposed a quantitative model of water-polluted ecological environment loss based on the emergy analysis method. It can reasonably quantify the ecological environment loss caused by water pollution and provide a reference for optimizing regional industrial layout, scientifically formulating pollution control planning, and promoting the sustainable development of the ecosystem. Taking Kaifeng City in Henan Province as an example, the rationality of the model is verified. The results show that the annual average total energy value of water pollution ecological environment loss in Kaifeng City is 3.83 × 1020sej, equivalent to 145 million yuan (0.76) of Kaifeng's GDP in 2018.
{"title":"Research on quantification method of water pollution ecological environment losses","authors":"C. Lv, Yabo Jue, Xi Guo, M. Ling, D. Yan","doi":"10.2166/aqua.2022.002","DOIUrl":"https://doi.org/10.2166/aqua.2022.002","url":null,"abstract":"\u0000 Economic and social development have worsened the situation of water pollution and even the ecological environment. It is helpful to quantify the water pollution ecological environment losses for decision-makers to formulate reasonable pollution control plans. However, the current quantitative analyses led by economic methods are not comprehensive and systematic. Therefore, based on the emergy theory and method system of eco-economics, this study analyzed the internal energy flow process of the water-polluted ecosystem, discussed the composition of water-polluted ecological environment loss, and proposed a quantitative model of water-polluted ecological environment loss based on the emergy analysis method. It can reasonably quantify the ecological environment loss caused by water pollution and provide a reference for optimizing regional industrial layout, scientifically formulating pollution control planning, and promoting the sustainable development of the ecosystem. Taking Kaifeng City in Henan Province as an example, the rationality of the model is verified. The results show that the annual average total energy value of water pollution ecological environment loss in Kaifeng City is 3.83 × 1020sej, equivalent to 145 million yuan (0.76) of Kaifeng's GDP in 2018.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82455690","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}
Reducing the quantity of water in recent years has increased the competition between development projects and the environment. Wetlands are increasingly under pressure due to human activities. The most serious threats to wetlands are excessive agriculture and the diversion of water for irrigation. In recent years, due to water shortage and drought, wetland dryness in Iran has caused many problems, including the dust crisis. Therefore, planning at the basin scale is necessary to achieve sustainable development, which emphasizes the employment of mathematical models. In this study, using a reliability-based simulation–optimization approach, development planning in the Karkheh basin with the following two objectives is investigated: (1) total area under cultivation of agricultural development sectors and (2) supply reliability of the environmental flow requirement. The Water Evaluation and Planning (WEAP) model is used for the simulation of water resources and the multi-objective particle swarm optimization (MOPSO) algorithm is employed for optimization. The results show that in addition to significantly improving the supply reliability of the wetland requirement (from 55 to 79%), the design of agricultural development projects has been optimized. The reliability-based model has prevented unsustainable developments in the basin. Also, the average supply reliability of agricultural demands has increased from 51% (in previous studies) to 72%.
{"title":"Sustainable water resource planning at the basin scale with simultaneous goals of agricultural development and wetland conservation","authors":"A. Hatamkhani, A. KhazaiePoul, A. Moridi","doi":"10.2166/aqua.2022.025","DOIUrl":"https://doi.org/10.2166/aqua.2022.025","url":null,"abstract":"\u0000 Reducing the quantity of water in recent years has increased the competition between development projects and the environment. Wetlands are increasingly under pressure due to human activities. The most serious threats to wetlands are excessive agriculture and the diversion of water for irrigation. In recent years, due to water shortage and drought, wetland dryness in Iran has caused many problems, including the dust crisis. Therefore, planning at the basin scale is necessary to achieve sustainable development, which emphasizes the employment of mathematical models. In this study, using a reliability-based simulation–optimization approach, development planning in the Karkheh basin with the following two objectives is investigated: (1) total area under cultivation of agricultural development sectors and (2) supply reliability of the environmental flow requirement. The Water Evaluation and Planning (WEAP) model is used for the simulation of water resources and the multi-objective particle swarm optimization (MOPSO) algorithm is employed for optimization. The results show that in addition to significantly improving the supply reliability of the wetland requirement (from 55 to 79%), the design of agricultural development projects has been optimized. The reliability-based model has prevented unsustainable developments in the basin. Also, the average supply reliability of agricultural demands has increased from 51% (in previous studies) to 72%.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90938836","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}
The ability of heavy metals to accumulate in living organisms, combined with the fact that they are not biodegradable, necessitates an expansion and improvement of the existing water purification methods. An effective mixing of contaminated water with heavy metals and magnetic nanoparticles is crucial for water treatment applications. In the present work, electromagnetic and shear mixing are combined to explore optimization mixing strategies. Mixing is studied through simulations under various initial conditions for two streams that are loaded with nanoparticles and one contaminated water stream that lies between the nanoparticle streams. In the present work, magnetic mixing is superimposed with a time-modulated gradient external magnetic field. The results show that as the radius ratio between the nanoparticles and the heavy metals increases, the external magnetic field is more effective insofar as the mixing of the nanoparticles is concerned. Moreover, for simulations where the radius ratio is higher or equal to 10, an effective mixing is achieved. By comparing the velocity ratios, a better mixing is achieved in the case of higher velocity ratios. Also, minor effects on mixing are observed by comparing the ratios Vp/Vc = 10 and Vp/Vc = 20.
{"title":"Mixing of Fe3O4 nanoparticles under electromagnetic and shear conditions for wastewater treatment applications","authors":"C. Liosis, E. Karvelas, T. Karakasidis, I. Sarris","doi":"10.2166/aqua.2022.080","DOIUrl":"https://doi.org/10.2166/aqua.2022.080","url":null,"abstract":"\u0000 The ability of heavy metals to accumulate in living organisms, combined with the fact that they are not biodegradable, necessitates an expansion and improvement of the existing water purification methods. An effective mixing of contaminated water with heavy metals and magnetic nanoparticles is crucial for water treatment applications. In the present work, electromagnetic and shear mixing are combined to explore optimization mixing strategies. Mixing is studied through simulations under various initial conditions for two streams that are loaded with nanoparticles and one contaminated water stream that lies between the nanoparticle streams. In the present work, magnetic mixing is superimposed with a time-modulated gradient external magnetic field. The results show that as the radius ratio between the nanoparticles and the heavy metals increases, the external magnetic field is more effective insofar as the mixing of the nanoparticles is concerned. Moreover, for simulations where the radius ratio is higher or equal to 10, an effective mixing is achieved. By comparing the velocity ratios, a better mixing is achieved in the case of higher velocity ratios. Also, minor effects on mixing are observed by comparing the ratios Vp/Vc = 10 and Vp/Vc = 20.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82027389","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}
To keep chlorine concentration at acceptable levels, chlorine is usually injected into the water distribution system (WDS). To protect the health of human beings, the chlorine concentration at consumers’ nodes should be kept at appropriate levels. However, these levels are difficult to determine due to the presence of fuzzy uncertainties. To deal with fuzziness at both sides of the constraints in the optimization model of booster chlorination, we propose a fuzzy credibility–constrained quadratic programming (FCCQP) model with a consideration of credibility levels and weight coefficients. The proposed model is applied to two WDSs to obtain the booster cost under uncertain conditions. The results indicate that the booster cost increases with the credibility level for lower chlorine concentration ζL. In addition, the booster cost decreases with the weight coefficient w. The booster cost function curves along with the variation of weight coefficients are concave and convex for scenario 1 and scenario 2, respectively. These results can help managers to make informed decisions on disinfection injection under conditions of fuzzy uncertainties.
{"title":"Fuzzy credibility–constrained quadratic optimization for booster chlorination of the water distribution system under uncertainty","authors":"Yumin Wang, G. Zhu","doi":"10.2166/aqua.2022.010","DOIUrl":"https://doi.org/10.2166/aqua.2022.010","url":null,"abstract":"\u0000 To keep chlorine concentration at acceptable levels, chlorine is usually injected into the water distribution system (WDS). To protect the health of human beings, the chlorine concentration at consumers’ nodes should be kept at appropriate levels. However, these levels are difficult to determine due to the presence of fuzzy uncertainties. To deal with fuzziness at both sides of the constraints in the optimization model of booster chlorination, we propose a fuzzy credibility–constrained quadratic programming (FCCQP) model with a consideration of credibility levels and weight coefficients. The proposed model is applied to two WDSs to obtain the booster cost under uncertain conditions. The results indicate that the booster cost increases with the credibility level for lower chlorine concentration ζL. In addition, the booster cost decreases with the weight coefficient w. The booster cost function curves along with the variation of weight coefficients are concave and convex for scenario 1 and scenario 2, respectively. These results can help managers to make informed decisions on disinfection injection under conditions of fuzzy uncertainties.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76741240","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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