A. Moghaddam, A. Faridhosseini, H. Rezaei, Roya Peirovi-Minaee, A. Ziaei
Abstract. In this research, reliability indicators of water distribution networks were evaluated under pipe failure conditions. The case studies included two benchmark networks and one real-life water distribution network in Iran with more hydraulic constraints. Some important reliability indicators were presented, such as resilience index, network resilience, modified resilience index, and minimum surplus head index. GANetXL was used to do the one-objective and two-objective optimization of the previously mentioned water distribution networks in order to not only minimize the cost but also maximize the reliability indicators. Moreover, the results of a statistical analysis for each pipe were used to determine the sensitive pipes that were of the most failure probability. GANetXL is an optimization tool in the Microsoft Excel environment and works based on a genetic algorithm. GANetXL has the capability of being linked to EPANET (hydraulic simulation software). The results obtained clearly showed that network resilience index was poor performance when compared with the other indexes under pipe failure conditions, especially in real-life networks that include small pipe diameters. It was also showed that if a water distribution network was optimized only in terms of cost, then there would be an unacceptable pressure drop at some nodes in case of pipe failure.
{"title":"The evaluation of hydraulic reliability indices in water distribution networks under pipe failure conditions","authors":"A. Moghaddam, A. Faridhosseini, H. Rezaei, Roya Peirovi-Minaee, A. Ziaei","doi":"10.5194/dwes-15-13-2022","DOIUrl":"https://doi.org/10.5194/dwes-15-13-2022","url":null,"abstract":"Abstract. In this research, reliability indicators of water distribution networks were evaluated under pipe failure conditions. The case studies included two\u0000benchmark networks and one real-life water distribution network in Iran with more hydraulic constraints. Some important reliability indicators were presented, such as resilience index, network resilience, modified resilience index, and minimum surplus head index. GANetXL was used to do the one-objective and two-objective optimization of the previously mentioned water distribution networks in order to not only minimize the cost but also maximize the reliability indicators. Moreover, the results of a statistical analysis for each pipe were used to determine the sensitive pipes that were of the most failure probability. GANetXL is an optimization tool in the Microsoft Excel environment and works based on a genetic algorithm. GANetXL has the capability of being linked to EPANET (hydraulic simulation software). The results obtained clearly showed that network resilience index was poor performance when compared with the other indexes under pipe failure conditions, especially in real-life networks that include small pipe diameters. It was also showed that if a water distribution network was optimized only in terms of cost, then there would be an unacceptable pressure drop at some nodes in case of pipe failure.\u0000","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46322272","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}
Abstract. Drinking water distribution networks form an essential part of modern-day critical infrastructure. Sectorizing a network into district metered areas is a key technique for pressure management and water loss reduction. Sectorizing an existing network from scratch is, however, an exceedingly complex design task that designs in a well-studied general mathematical problem. Numerical optimization techniques such as evolutionary algorithms can be used to search for near-optimal solutions to such problems, but doing so within a reasonable timeframe remains an ongoing challenge. In this work, we introduce two heuristic tricks that use information of the network structure and information of the operational requirements of the drinking water distribution network to modify the basic evolutionary algorithm used to solve the general problem. These techniques not only reduce the time required to find good solutions, but also ensure that these solutions better match the requirements of drinking water practice. Both techniques were demonstrated by applying them in the sectorization of the actual distribution network of a large city.
{"title":"Technical note: Graph theory-based heuristics to aid in the implementation of optimized drinking water network sectorization","authors":"M. M. Rokstad, Karel A van Laarhoven","doi":"10.5194/dwes-2021-11","DOIUrl":"https://doi.org/10.5194/dwes-2021-11","url":null,"abstract":"Abstract. Drinking water distribution networks form an essential part of modern-day critical infrastructure. Sectorizing a network into district metered areas is a key technique for pressure management and water loss reduction. Sectorizing an existing network from scratch is, however, an exceedingly complex design task that designs in a well-studied general mathematical problem. Numerical optimization techniques such as evolutionary algorithms can be used to search for near-optimal solutions to such problems, but doing so within a reasonable timeframe remains an ongoing challenge. In this work, we introduce two heuristic tricks that use information of the network structure and information of the operational requirements of the drinking water distribution network to modify the basic evolutionary algorithm used to solve the general problem. These techniques not only reduce the time required to find good solutions, but also ensure that these solutions better match the requirements of drinking water practice. Both techniques were demonstrated by applying them in the sectorization of the actual distribution network of a large city.\u0000","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44652611","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}
S. Adio, Emmanuel A. Osowade, A. Muritala, A. Fadairo, K. Oladepo, S. Obayopo, Paul O. Fase
Abstract. The enormous problems caused by the scarcity of potable water and the transmission of waterborne diseases such as cholera, dracunculiasis, hepatitis, typhoid and filariasis in some parts of Nigeria have created a public health concern. Every day thousands of lives are lost due to contact with waterborne diseases. The insufficient medical resources available in developing countries are deployed towards the treatment of waterborne diseases that can easily be avoided if potable water can be made available. This study seeks to investigate the purification of four different water samples (namely water from flowing rivers, freshly dug well or groundwater, rainwater from the rooftops and heavily polluted dirty water) consumed by the people in the local community using a solar desalination method. A single basin solar still was constructed, and experimental studies were carried out to determine the influence of solar insolation and temperature variations on the yield of the distillate for both the passive and active solar stills tested. The quality of the distillate was tested by measuring the total dissolved solid (TDS) and electrical conductivity (EC) and later comparing it to the World Health Organization (WHO) standard for drinkable water. The values obtained after desalination fall within the acceptable/tolerable range for TDS and EC, in accordance with the WHO standard for drinkable water. This analysis provides an indigenous distillation method to enhance the production of drinkable water at a low cost.
{"title":"Solar distillation of impure water from four different water sources under the southwestern Nigerian climate","authors":"S. Adio, Emmanuel A. Osowade, A. Muritala, A. Fadairo, K. Oladepo, S. Obayopo, Paul O. Fase","doi":"10.5194/DWES-14-81-2021","DOIUrl":"https://doi.org/10.5194/DWES-14-81-2021","url":null,"abstract":"Abstract. The enormous problems caused by the scarcity of potable water\u0000and the transmission of waterborne diseases such as cholera, dracunculiasis, hepatitis, typhoid and filariasis in some parts of Nigeria have created a public health concern. Every day thousands of lives are lost due to contact with waterborne diseases. The insufficient medical resources available in developing countries are deployed towards the treatment of waterborne diseases that can easily be avoided if potable water can be made available. This study seeks to investigate the purification of four different water samples\u0000(namely water from flowing rivers, freshly dug well or groundwater,\u0000rainwater from the rooftops and heavily polluted dirty water) consumed by\u0000the people in the local community using a solar desalination method. A single basin solar still was constructed, and experimental studies were carried out to determine the influence of solar insolation and temperature variations on the yield of the distillate for both the passive and active solar stills tested. The quality of the distillate was tested by measuring the total dissolved solid (TDS) and electrical conductivity (EC) and later comparing it to the World Health Organization (WHO) standard for drinkable water. The values obtained after desalination fall within the acceptable/tolerable range for TDS and EC, in accordance with the WHO standard for drinkable water. This analysis provides an indigenous distillation method to enhance the production of drinkable water at a low cost.","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":"14 1","pages":"81-94"},"PeriodicalIF":0.0,"publicationDate":"2021-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43596165","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}
Jolijn van Engelenburg, Erik van Slobbe, A. Teuling, R. Uijlenhoet, P. Hellegers
Abstract. Developments such as climate change and a growing demand for drinking water threaten the sustainability of drinking water supply worldwide. To deal with this threat, adaptation of drinking water supply systems is imperative, not only on a global and national scale but particularly on a local scale. This investigation sought to establish characteristics that describe the sustainability of local drinking water supply. The hypothesis of this research was that sustainability characteristics depend on the context that is analysed, and therefore, a variety of cases must be analysed to reach a better understanding of the sustainability of drinking water supply in the Netherlands. Therefore, three divergent cases on drinking water supply in the Netherlands were analysed. One case related to a short-term development (2018 summer drought), and two concerned long-term phenomena (changes in water quality and growth in drinking water demand). We used an integrated systems approach, describing the local drinking water supply system in terms of hydrological, technical, and socio-economic characteristics that determine the sustainability of a local drinking water supply system. To gain a perspective on the case study findings that are broader than the Dutch context, the sustainability aspects identified were paired with global aspects concerning sustainable drinking water supply. This resulted in the following set of hydrological, technical, and socio-economic sustainability characteristics: (1) water quality, water resource availability, and impact of drinking water abstraction; (2) reliability and resilience of the technical system and energy use and environmental impact; (3) drinking water availability, water governance, and land and water use. Elaboration of these sustainability characteristics and criteria into a sustainability assessment can provide information on the challenges and trade-offs inherent in the sustainable development and management of a local drinking water supply system.
{"title":"Sustainability characteristics of drinking water supply in the Netherlands","authors":"Jolijn van Engelenburg, Erik van Slobbe, A. Teuling, R. Uijlenhoet, P. Hellegers","doi":"10.5194/DWES-14-1-2021","DOIUrl":"https://doi.org/10.5194/DWES-14-1-2021","url":null,"abstract":"Abstract. Developments such as climate change and a growing demand for drinking water threaten the sustainability of drinking water supply worldwide. To deal with\u0000this threat, adaptation of drinking water supply systems is imperative, not\u0000only on a global and national scale but particularly on a local scale. This investigation sought to establish characteristics that describe the\u0000sustainability of local drinking water supply. The hypothesis of this\u0000research was that sustainability characteristics depend on the context that\u0000is analysed, and therefore, a variety of cases must be analysed to reach a\u0000better understanding of the sustainability of drinking water supply in the\u0000Netherlands. Therefore, three divergent cases on drinking water supply in\u0000the Netherlands were analysed. One case related to a short-term development\u0000(2018 summer drought), and two concerned long-term phenomena (changes in\u0000water quality and growth in drinking water demand). We used an integrated\u0000systems approach, describing the local drinking water supply system in terms of hydrological, technical, and socio-economic characteristics that\u0000determine the sustainability of a local drinking water supply system. To\u0000gain a perspective on the case study findings that are broader than the Dutch context, the sustainability aspects identified were paired with global aspects concerning sustainable drinking water supply. This resulted in the following set of hydrological, technical, and socio-economic sustainability characteristics: (1) water quality, water resource availability, and impact of drinking water abstraction; (2) reliability and resilience of the technical system and energy use and environmental impact; (3) drinking water availability, water governance, and land and water use. Elaboration of these sustainability characteristics and criteria into a sustainability assessment can provide information on the challenges and trade-offs inherent in the sustainable development and management of a local drinking water supply system.\u0000","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43609451","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}
M. Al-Furaiji, M. Kadhom, Khairi R. Kalash, B. Waisi, N. Albayati
Abstract. The forward osmosis (FO) process has been considered to be a viable option for water desalination in comparison to the traditional processes like reverse osmosis, regarding energy consumption and economical operation. In this work, a polyacrylonitrile (PAN) nanofiber support layer was prepared using the electrospinning process as a modern method. Then, an interfacial polymerization reaction between m -phenylenediamine (MPD) and trimesoyl chloride (TMC) was carried out to generate a polyamide selective thin-film composite (TFC) membrane on the support layer. The TFC membrane was tested in FO mode (feed solution facing the active layer) using the standard methodology and compared to a commercially available cellulose triacetate membrane (CTA). The synthesized membrane showed a high performance in terms of water flux (16 Lm −2 h −1 ) but traded the salt rejection (4 gm −2 h −1 ) compared with the commercial CTA membrane (water flux = 13 Lm −2 h −1 and salt rejection = 3 gm −2 h −1 ) at no applied pressure and room temperature. Scanning electron microscopy (SEM), contact angle, mechanical properties, porosity, and performance characterizations were conducted to examine the membrane.
{"title":"Preparation of thin-film composite membranes supported with electrospun nanofibers for desalination by forward osmosis","authors":"M. Al-Furaiji, M. Kadhom, Khairi R. Kalash, B. Waisi, N. Albayati","doi":"10.5194/dwes-13-51-2020","DOIUrl":"https://doi.org/10.5194/dwes-13-51-2020","url":null,"abstract":"Abstract. The forward osmosis (FO) process has been considered to be a viable option for water desalination in comparison to the traditional processes like reverse\u0000osmosis, regarding energy consumption and economical operation. In this\u0000work, a polyacrylonitrile (PAN) nanofiber support layer was prepared using the electrospinning process as a modern method. Then, an interfacial\u0000polymerization reaction between m -phenylenediamine (MPD) and trimesoyl chloride (TMC) was carried out to generate a polyamide selective thin-film composite (TFC) membrane on the support layer. The TFC membrane was tested\u0000in FO mode (feed solution facing the active layer) using the standard\u0000methodology and compared to a commercially available cellulose triacetate\u0000membrane (CTA). The synthesized membrane showed a high performance in terms\u0000of water flux (16 Lm −2 h −1 ) but traded the salt rejection (4 gm −2 h −1 ) compared with the commercial CTA membrane (water flux = 13 Lm −2 h −1 and salt rejection = 3 gm −2 h −1 ) at\u0000no applied pressure and room temperature. Scanning electron microscopy\u0000(SEM), contact angle, mechanical properties, porosity, and performance\u0000characterizations were conducted to examine the membrane.","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":"13 1","pages":"51-57"},"PeriodicalIF":0.0,"publicationDate":"2020-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49424388","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}
Abstract. The forward osmosis (FO) process has been considered for desalination as a competitive option with respect to the traditional reverse osmosis process. The interfacial polymerization (IP) reaction between two monomers (i.e., m-phenylenediamine, MPD, and 1,3,5-benzenetricarbonyl chloride, TMC) is typically used to prepare the selective polyamide layer that prevents salts and allows water molecules to pass. In this research, we investigated the effect of preparation conditions (MPD contact time, TMC reaction time, and addition of an amine salt) on the FO performance in terms of water flux and salt flux. The results showed that increasing MPD contact time resulted in a significant increase in the water flux and salt flux. However, increasing TMC reaction time caused a decline in both the water flux and the salt flux. The optimum condition that gave the highest water flux (64 L m−2 h−1) was found to be as 5 min for MPD and 1 min for TMC. The addition of an amine salt of camphorsulfonic acid-triethylamine (CSA-TEA) was able to have an apparent effect on the FO process by increasing the water flux (74.5 L m−2 h−1).
摘要与传统的反渗透工艺相比，正渗透(FO)工艺被认为是一种具有竞争力的脱盐工艺。两个单体(即间苯二胺，MPD和1,3,5-苯三羰基氯，TMC)之间的界面聚合(IP)反应通常用于制备选择性聚酰胺层，该层可以阻止盐并允许水分子通过。在本研究中，我们考察了制备条件(MPD接触时间、TMC反应时间和胺盐的加入)对水通量和盐通量性能的影响。结果表明，随着MPD接触时间的增加，水通量和盐通量显著增加。但随着TMC反应时间的延长，水通量和盐通量均呈下降趋势。最佳水通量(64 L m−2 h−1)为MPD为5 min, TMC为1 min。樟脑磺酸-三乙胺胺盐(CSA-TEA)的加入能够通过增加水通量(74.5 L m−2 h−1)对FO过程产生明显的影响。
{"title":"Evaluation of thin film composite forward osmosis membranes: effect of polyamide preparation conditions","authors":"Aya Mohammed Kadhom, M. Al-Furaiji, Z. N. Abudi","doi":"10.5194/dwes-2020-33","DOIUrl":"https://doi.org/10.5194/dwes-2020-33","url":null,"abstract":"Abstract. The forward osmosis (FO) process has been considered for\u0000desalination as a competitive option with respect to the traditional reverse osmosis process. The interfacial polymerization (IP) reaction between two monomers (i.e., m-phenylenediamine, MPD, and 1,3,5-benzenetricarbonyl chloride, TMC) is typically used to prepare the selective polyamide layer that prevents salts and allows water molecules to pass. In this research, we investigated the effect of preparation conditions (MPD contact time, TMC reaction time, and addition of an amine salt) on the FO performance in terms of water flux and salt flux. The results showed that increasing MPD contact time resulted in a significant increase in the water flux and salt flux. However, increasing TMC reaction time caused a decline in both the water flux and the salt flux. The optimum condition that gave the highest water flux (64 L m−2 h−1) was found to be as 5 min for MPD and 1 min for TMC. The addition of an amine salt of camphorsulfonic acid-triethylamine (CSA-TEA) was able to have an apparent effect on the FO process by increasing the water flux (74.5 L m−2 h−1).\u0000","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48258330","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}
Pub Date : 2020-10-15DOI: 10.5194/dwes-2020-30-supplement
O. Kramer, P. D. de Moel, S. Raaghav, E. Baars, W. H. van Vugt, W. Breugem, J. Padding, J. P. van der Hoek
Abstract. Natural particles are frequently applied in drinking water treatment processes in fixed bed reactors, fluidised bed reactors, and sedimentation processes to clarify water and to concentrate solids. When particles settle, it has been found that, in terms of hydraulics, natural particles behave differently when compared to perfectly round spheres. To estimate the terminal settling velocity of single solid particles in a liquid system, a comprehensive collection of equations is available. For perfectly round spheres, the settling velocity can be calculated quite accurately. However, for naturally polydisperse non-spherical particles, experimentally measured settling velocities of individual particles show considerable spread from the calculated average values. This work aims to analyse and explain the different causes of this spread. To this end, terminal settling experiments were conducted in a quiescent fluid with particles varying in density, size, and shape. For the settling experiments, opaque and transparent spherical polydisperse and monodisperse glass beads were selected. In this study, we also examined drinking-water-related particles, like calcite pellets and crushed calcite seeding material grains, which are both applied in drinking water softening. Polydisperse calcite pellets were sieved and separated to acquire more uniformly dispersed samples. In addition, a wide variety of grains with different densities, sizes, and shapes were investigated for their terminal settling velocity and behaviour. The derived drag coefficient was compared with well-known models such as the one of Brown and Lawler (2003). A sensitivity analysis showed that the spread is caused, to a lesser extent, by variations in fluid properties, measurement errors, and wall effects. Natural variations in specific particle density, path trajectory instabilities, and distinctive multi-particle settling behaviour caused a slightly larger degree of the spread. In contrast, a greater spread is caused by variations in particle size, shape, and orientation. In terms of robust process designs and adequate process optimisation for fluidisation and sedimentation of natural granules, it is therefore crucial to take into consideration the influence of the natural variations in the settling velocity when using predictive models of round spheres.
{"title":"Can terminal settling velocity and drag of natural particles in water ever be predicted accurately?","authors":"O. Kramer, P. D. de Moel, S. Raaghav, E. Baars, W. H. van Vugt, W. Breugem, J. Padding, J. P. van der Hoek","doi":"10.5194/dwes-2020-30-supplement","DOIUrl":"https://doi.org/10.5194/dwes-2020-30-supplement","url":null,"abstract":"Abstract. Natural particles are frequently applied in drinking water treatment processes in fixed bed reactors, fluidised bed reactors, and sedimentation processes to clarify water and to concentrate solids. When particles settle, it has been found that, in terms of hydraulics, natural particles behave differently when compared to perfectly round spheres. To estimate the terminal settling velocity of single solid particles in a liquid system, a comprehensive collection of equations is available. For perfectly round spheres, the settling velocity can be calculated quite accurately. However, for naturally polydisperse non-spherical particles, experimentally measured settling velocities of individual particles show considerable spread from the calculated average values. This work aims to analyse and explain the different causes of this spread. To this end, terminal settling experiments were conducted in a quiescent fluid with particles varying in density, size, and shape. For the settling experiments, opaque and transparent spherical polydisperse and monodisperse glass beads were selected. In this study, we also examined drinking-water-related particles, like calcite pellets and crushed calcite seeding material grains, which are both applied in drinking water softening. Polydisperse calcite pellets were sieved and separated to acquire more uniformly dispersed samples. In addition, a wide variety of grains with different densities, sizes, and shapes were investigated for their terminal settling velocity and behaviour. The derived drag coefficient was compared with well-known models such as the one of Brown and Lawler (2003). A sensitivity analysis showed that the spread is caused, to a lesser extent, by variations in fluid properties, measurement errors, and wall effects. Natural variations in specific particle density, path trajectory instabilities, and distinctive multi-particle settling behaviour caused a slightly larger degree of the spread. In contrast, a greater spread is caused by variations in particle size, shape, and orientation. In terms of robust process designs and adequate process optimisation for fluidisation and sedimentation of natural granules, it is therefore crucial to take into consideration the influence of the natural variations in the settling velocity when using predictive models of round spheres.","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41764866","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}
Abstract. The role of a drinking water distribution network (DWDN) is to supply high-quality water at the necessary pressure at various times of the day for several consumption scenarios. Locating and identifying water leakage areas has become a major concern for managers of the water supply, to optimize and improve constancy of supply. In this paper, we present the results of field research conducted to detect and to locate leaks in the DWDN focusing on the resolution of the Fixed And Variable Area Discharge (FAVAD) equation by use of the prediction algorithms in conjunction with hydraulic modeling and the Geographical Information System (GIS). The leak localization method is applied in the oldest part of Casablanca. We have used, in this research, two methodologies in different leak episodes: (i) the first episode is based on a simulation of artificial leaks on the MATLAB platform using the EPANET code to establish a database of pressures that describes the network's behavior in the presence of leaks. The data thus established have been fed into a machine learning algorithm called random forest, which will forecast the leakage rate and its location in the network; (ii) the second was field-testing a real simulation of artificial leaks by opening and closing of hydrants, on different locations with a leak size of 6 and 17 L s −1 . The two methods converged to comparable results. The leak position is spotted within a 100 m radius of the actual leaks.
摘要饮用水分配网络（DWDN）的作用是在一天中的不同时间以必要的压力为多种消费场景提供高质量的水。定位和识别漏水区域已成为供水管理者的主要关注点，以优化和提高供水的稳定性。在本文中，我们介绍了为检测和定位WDN中的泄漏而进行的现场研究的结果，重点是通过使用预测算法结合水力建模和地理信息系统（GIS）来解决固定和可变面积流量（FAVAD）方程。泄漏定位方法应用于卡萨布兰卡最古老的地区。在这项研究中，我们在不同的泄漏事件中使用了两种方法：（i）第一个事件是基于MATLAB平台上的人工泄漏模拟，使用EPANET代码建立压力数据库，描述网络在存在泄漏时的行为。这样建立的数据被输入到一个称为随机森林的机器学习算法中，该算法将预测泄漏率及其在网络中的位置；（ii）第二个是通过打开和关闭消防栓，在泄漏尺寸为6和17的不同位置进行人工泄漏的真实模拟现场测试 L s−1。这两种方法的结果相近。泄漏位置在100 m实际泄漏的半径。
{"title":"Prelocalization and leak detection in drinking water distribution networks using modeling-based algorithms: a case study for the city of Casablanca (Morocco)","authors":"Faycal Taghlabi, Laila Sour, A. Agoumi","doi":"10.5194/DWES-13-29-2020","DOIUrl":"https://doi.org/10.5194/DWES-13-29-2020","url":null,"abstract":"Abstract. The role of a drinking water distribution network (DWDN)\u0000is to supply high-quality water at the necessary pressure at various times\u0000of the day for several consumption scenarios. Locating and identifying water\u0000leakage areas has become a major concern for managers of the water supply,\u0000to optimize and improve constancy of supply. In this paper, we present the\u0000results of field research conducted to detect and to locate leaks in the\u0000DWDN focusing on the resolution of the Fixed And Variable Area Discharge\u0000(FAVAD) equation by use of the prediction algorithms in conjunction with\u0000hydraulic modeling and the Geographical Information System (GIS). The leak\u0000localization method is applied in the oldest part of Casablanca. We have\u0000used, in this research, two methodologies in different leak episodes: (i) the\u0000first episode is based on a simulation of artificial leaks on the MATLAB\u0000platform using the EPANET code to establish a database of pressures that\u0000describes the network's behavior in the presence of leaks. The data thus\u0000established have been fed into a machine learning algorithm called random forest,\u0000which will forecast the leakage rate and its location in the network;\u0000(ii) the second was field-testing a real simulation of artificial leaks by\u0000opening and closing of hydrants, on different locations with a leak size of\u00006 and 17 L s −1 . The two methods converged to comparable results. The leak\u0000position is spotted within a 100 m radius of the actual leaks.","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":"13 1","pages":"29-41"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41587101","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}
Abstract. The objective of this study is to prepare a cellulose paper that was impregnated with silver nanoparticles (AgNPs) for the purpose of water purification (disinfection and filtration). AgNP papers were prepared by chemical reduction of silver nitrate (AgNO3) with various concentrations (0.005 M, 0.015 M, 0.03 M, and 0.05 M) using sodium borohydride (NaBH4) as a reducing agent. Two ratios for NaBH4/AgNO3 of 2:1 and 10:1 were used to show the effect of reduction on the formation and removal efficiencies of AgNPs. AgNP papers were characterized using scanning electron microscopy and transmission electron microscopy. An acid digestion using HCl acid followed by analyzing the samples in an atomic absorption spectrometer (ASS) was conducted to measure the silver concentration in AgNP papers. TEM images showed that the silver nanoparticle size in the papers varied from 1.3 to 75 nm. Water samples, after filtration through AgNP papers, were analyzed using ASS to measure the silver concentration in the effluent water. AgNP paper antibacterial efficiency ranged from 99 % to 100 % for both reduction ratios. The average silver content in the effluent water for the three replicates ranged from 0 to 0.082 mg L−1, which meets the United States Environmental Protection Agency (US-EPA) guideline for drinking water of less than 0.1 mg L−1. Turbidity tests showed that these papers can be usefully used as point-of-use filters as the turbidity reduced to less than 1 NTU (Nephelometric Turbidity Units).
{"title":"Surface-water purification using cellulose paper impregnated with silver nanoparticles","authors":"S. Raheem, A. H. Al-Fatlawi","doi":"10.5194/dwes-2020-23","DOIUrl":"https://doi.org/10.5194/dwes-2020-23","url":null,"abstract":"Abstract. The objective of this study is to prepare a cellulose paper that was impregnated with silver nanoparticles (AgNPs) for the purpose of water\u0000purification (disinfection and filtration). AgNP papers were prepared by chemical reduction of silver nitrate (AgNO3) with various\u0000concentrations (0.005 M, 0.015 M, 0.03 M, and 0.05 M) using sodium borohydride (NaBH4) as a reducing\u0000agent. Two ratios for NaBH4/AgNO3 of 2:1 and 10:1 were used to show the effect of reduction on the formation and removal\u0000efficiencies of AgNPs. AgNP papers were characterized using scanning electron microscopy and transmission electron microscopy. An acid digestion\u0000using HCl acid followed by analyzing the samples in an atomic absorption spectrometer (ASS) was conducted to measure the silver concentration in AgNP\u0000papers. TEM images showed that the silver nanoparticle size in the papers varied from 1.3 to 75 nm. Water samples, after filtration through AgNP papers, were analyzed using ASS to measure the silver concentration in the effluent water. AgNP paper\u0000antibacterial efficiency ranged from 99 % to 100 % for both reduction ratios. The average silver content in the effluent water for the three\u0000replicates ranged from 0 to 0.082 mg L−1, which meets the United States Environmental Protection Agency (US-EPA) guideline for drinking\u0000water of less than 0.1 mg L−1. Turbidity tests showed that these papers can be usefully used as point-of-use filters as the turbidity\u0000reduced to less than 1 NTU (Nephelometric Turbidity Units).\u0000","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46144720","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}
Abstract. It is common for bottled water and other assorted drinks to be seen displayed outside stores and in the sun in most parts of Nigeria. The country is mostly hot year-round, and over the course of the year, temperatures can rise to as high as 40 ∘C around March–April in the study area. The leaching effect of chemicals from polyethylene terephthalate (PET) bottled water was investigated for five commercially available bottled water brands. Temperature, pH, antimony, bisphenol A (BPA), and nitrate levels were measured on days 0, 14, and 28 for control samples and samples exposed to direct sunlight, using destructive sampling technique. Antimony was not detected in brands A, B, and E in the baseline measurement at day 0, while brands C and D had low values; after 28 d all the control samples still had antimony levels within the United States Environmental Protection Agency (US EPA) standard. Meanwhile, all the samples exposed to sunlight exceeded US EPA standard levels at 14 and 28 d, except brand A which was within limit at 14 d with value of 4.59 µg L−1. All control and exposed samples were below the European Union Drinking Water Directive (EU DWD) total daily intake (TDI) of BPA (0.05 mg per kilogram of body weight)−1 d−1. Values obtained for nitrate showed that all control samples did not exceed the US EPA guideline level for nitrates in drinking water for days 0, 14, and 28, while three of the samples, i.e. brands C, D, and E, exceeded the guideline level at day 28. Exposure of bottled water to sunlight was seen to impair the quality of the water for consumption.
{"title":"Evaluation of changes in some physico-chemical properties of bottled water exposed to sunlight in Bauchi State, Nigeria","authors":"R. Daffi, F. Wamyil","doi":"10.5194/dwes-2020-19","DOIUrl":"https://doi.org/10.5194/dwes-2020-19","url":null,"abstract":"Abstract. It is common for bottled water and other assorted drinks to be seen displayed outside stores and in the sun in most parts of Nigeria. The country is mostly hot year-round, and over the course of the year, temperatures can rise to as high as 40 ∘C around March–April in the study area. The leaching effect of chemicals from polyethylene terephthalate (PET) bottled water was investigated for five commercially available bottled water brands. Temperature, pH, antimony, bisphenol A (BPA), and nitrate levels were measured on days 0, 14, and 28 for control samples and samples exposed to direct sunlight, using destructive sampling technique. Antimony was not detected in brands A, B, and E in the baseline measurement at day 0, while brands C and D had low values; after 28 d all the control\u0000samples still had antimony levels within the United States Environmental\u0000Protection Agency (US EPA) standard. Meanwhile, all the samples exposed to\u0000sunlight exceeded US EPA standard levels at 14 and 28 d, except brand A\u0000which was within limit at 14 d with value of 4.59 µg L−1. All control\u0000and exposed samples were below the European Union Drinking Water Directive\u0000(EU DWD) total daily intake (TDI) of BPA (0.05 mg per kilogram of body\u0000weight)−1 d−1. Values obtained for nitrate showed that all control samples did not exceed the US EPA guideline level for nitrates in drinking water for days 0, 14, and 28, while three of the samples, i.e. brands C, D, and E, exceeded the guideline level at day 28. Exposure of bottled water to sunlight was seen to impair the quality of the water for consumption.\u0000","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71218492","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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