S.M.L. Stubbé, A. Pelgrim-Adams, G. Szántó, D. Halem
Abstract. Household Water Treatment and safe Storage (HWTS) systems aim to provide safe drinking water in an affordable manner to users where safe piped water supply is either not feasible or not reliable. In this study the effectiveness, economic parameters and costs of three selected HWTS systems were identified. The selected systems are SODIS, ceramic filter and biosand filter. These options were selected based on their accessibility, affordability and available scientific data. Data was obtained through peer-reviewed literature, reports, web-pages and informal sources. The findings show a wide dispersion for log removal of effectiveness of the HWTS systems. For bacteria (E. coli), log removals of 1–9 (SODIS), 0.5–7.2 (ceramic) and 0–3 (biosand) were reported. In the case of viruses (mostly echovirus and bacteriophages), log removals of 0–4.3 (SODIS), 0.09–2.4 (ceramic) and 0–7 (biosand) were found. The dispersions of log removals for both bacteria and viruses range from non-protective to highly protective according to WHO performance targets. The reported costs of HWTS systems show a wide range as well. The price per cubic meter water is found to be EUR 0–8 (SODIS), EUR 0.37–6.4 (ceramic) and EUR 0.08–12.3 (biosand). The retail prices found are: negligible (SODIS), USD 1.9–30 (ceramic) and USD 7–100 (biosand). No relationship was observed between removal efficiency and economics of the three systems.
{"title":"Household water treatment and safe storage – effectiveness and economics","authors":"S.M.L. Stubbé, A. Pelgrim-Adams, G. Szántó, D. Halem","doi":"10.5194/DWES-9-9-2016","DOIUrl":"https://doi.org/10.5194/DWES-9-9-2016","url":null,"abstract":"Abstract. Household Water Treatment and safe Storage (HWTS) systems aim to provide safe drinking water in an affordable manner to users where safe piped water supply is either not feasible or not reliable. In this study the effectiveness, economic parameters and costs of three selected HWTS systems were identified. The selected systems are SODIS, ceramic filter and biosand filter. These options were selected based on their accessibility, affordability and available scientific data. Data was obtained through peer-reviewed literature, reports, web-pages and informal sources. The findings show a wide dispersion for log removal of effectiveness of the HWTS systems. For bacteria (E. coli), log removals of 1–9 (SODIS), 0.5–7.2 (ceramic) and 0–3 (biosand) were reported. In the case of viruses (mostly echovirus and bacteriophages), log removals of 0–4.3 (SODIS), 0.09–2.4 (ceramic) and 0–7 (biosand) were found. The dispersions of log removals for both bacteria and viruses range from non-protective to highly protective according to WHO performance targets. The reported costs of HWTS systems show a wide range as well. The price per cubic meter water is found to be EUR 0–8 (SODIS), EUR 0.37–6.4 (ceramic) and EUR 0.08–12.3 (biosand). The retail prices found are: negligible (SODIS), USD 1.9–30 (ceramic) and USD 7–100 (biosand). No relationship was observed between removal efficiency and economics of the three systems.","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":"9 1","pages":"9-18"},"PeriodicalIF":0.0,"publicationDate":"2015-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71222399","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 heating of drinking water in households contributes significantly to the emission of greenhouse gases. As a water utility aiming to operate at a climate neutral level by 2020, Waternet needs to reduce its CO2 emission by 53?kton?yr?1. To contribute to this ambition, a pilot project was carried out in Uilenstede, Amstelveen, the Netherlands, to recover the shower heat energy with a shower heat exchanger from Dutch Solar Systems. An experimental setup was built in the Waternet laboratory to evaluate the claimed efficiencies. The energy recovery efficiency observed in the lab was 61–64?% under winter conditions and 57–62?% under summer conditions, while the energy recovery efficiency observed in Uilenstede was 57?% in December 2014. Based on the observations, 4?% of the total energy consumption of households in Amsterdam (electricity and gas) can be recovered with a shower heat exchanger installed in all households in Amsterdam, which also means a 54?kton?year?1 CO2 emission reduction can be achieved.
{"title":"Shower heat exchanger: Reuse of energy from heated drinking water for CO2 reduction","authors":"Z. Deng, S. Mol, J. Hoek","doi":"10.5194/DWES-9-1-2016","DOIUrl":"https://doi.org/10.5194/DWES-9-1-2016","url":null,"abstract":"The heating of drinking water in households contributes significantly to the emission of greenhouse gases. As a water utility aiming to operate at a climate neutral level by 2020, Waternet needs to reduce its CO2 emission by 53?kton?yr?1. To contribute to this ambition, a pilot project was carried out in Uilenstede, Amstelveen, the Netherlands, to recover the shower heat energy with a shower heat exchanger from Dutch Solar Systems. An experimental setup was built in the Waternet laboratory to evaluate the claimed efficiencies. The energy recovery efficiency observed in the lab was 61–64?% under winter conditions and 57–62?% under summer conditions, while the energy recovery efficiency observed in Uilenstede was 57?% in December 2014. Based on the observations, 4?% of the total energy consumption of households in Amsterdam (electricity and gas) can be recovered with a shower heat exchanger installed in all households in Amsterdam, which also means a 54?kton?year?1 CO2 emission reduction can be achieved.","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":"9 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2015-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71222503","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}
Drinking water companies (are intending to) implement advanced oxidation processes (AOP) in their treatment schemes to increase the barrier against organic micropollutants (OMPs). It is necessary to decompose the excessive hydrogen peroxide after applying AOP to avoid negative effects in the following, often biological, treatment steps. A drinking water company in the western part of the Netherlands investigated decomposition of about 5.75 mg L?1 hydrogen peroxide in pre-treated Meuse river water with different catalysts on pilot scale. In down flow operation, the necessary reactor empty bed contact time (EBCT) with the commonly used granulated activated carbon (GAC) and waste ground water filter gravel (MCFgw) were found equal with 149 s, corresponding with a conversion rate constant r of 0.021 s?1. The EBCT of the fine coating of ground water filter gravel (MC) was significantly shorter with a little more than 10 s (r = 0.30 s?1). In up flow operation, with a flow rate of 20 m h?1, the EBCT of coating MC increased till about 100 s (r = 0.031 s?1), from which can be concluded, that the performance of this waste material is better compared with GAC, in both up and down flow operation. The necessary EBCT at average filtration rate of full scale dual layer filter material (MCFsw) amounted to 209 s (r= 0.015 s?1). Regarding the average residence time in the full scale filters of 700 s, applying AOP in front of the filters could be an interesting alternative which makes a separate decomposition installation superfluous, on the condition that the primary functions of the filters are not affected.
饮用水公司(打算)在其处理方案中实施高级氧化工艺(AOP)，以增加对有机微污染物(OMPs)的屏障。在应用AOP之后，有必要分解过量的过氧化氢，以避免在接下来的(通常是生物的)处理步骤中产生负面影响。荷兰西部的一家饮用水公司调查了大约5.75 mg L?用不同催化剂预处理默兹河水中的过氧化氢。下流运行时，反应器空床与常用颗粒状活性炭(GAC)和废弃地下水滤石(MCFgw)的接触时间为149 s，对应的转化率常数r为0.021 s?1。地下水过滤砾石(MC)细密包覆层的EBCT显著缩短，略大于10 s (r = 0.30 s?1)。在上流工况下，流速为20 m h?1、涂层MC的EBCT增加到100 s左右(r = 0.031 s?1)，由此可以看出，无论在上下流动操作中，该废料的性能都优于GAC。全尺寸双层滤料(MCFsw)平均过滤速率下所需EBCT为209 s (r= 0.015 s?1)。考虑到全尺寸过滤器中的平均停留时间为700秒，在过滤器前面应用AOP可能是一个有趣的替代方案，在过滤器的主要功能不受影响的情况下，它使单独的分解安装变得多余。
{"title":"Natural manganese deposits as catalyst for decomposing hydrogen peroxide","authors":"A. H. Knol, K. Lekkerkerker-Teunissen, J. V. Dijk","doi":"10.5194/DWES-8-3-2015","DOIUrl":"https://doi.org/10.5194/DWES-8-3-2015","url":null,"abstract":"Drinking water companies (are intending to) implement advanced oxidation processes (AOP) in their treatment schemes to increase the barrier against organic micropollutants (OMPs). It is necessary to decompose the excessive hydrogen peroxide after applying AOP to avoid negative effects in the following, often biological, treatment steps. A drinking water company in the western part of the Netherlands investigated decomposition of about 5.75 mg L?1 hydrogen peroxide in pre-treated Meuse river water with different catalysts on pilot scale. In down flow operation, the necessary reactor empty bed contact time (EBCT) with the commonly used granulated activated carbon (GAC) and waste ground water filter gravel (MCFgw) were found equal with 149 s, corresponding with a conversion rate constant r of 0.021 s?1. The EBCT of the fine coating of ground water filter gravel (MC) was significantly shorter with a little more than 10 s (r = 0.30 s?1). In up flow operation, with a flow rate of 20 m h?1, the EBCT of coating MC increased till about 100 s (r = 0.031 s?1), from which can be concluded, that the performance of this waste material is better compared with GAC, in both up and down flow operation. The necessary EBCT at average filtration rate of full scale dual layer filter material (MCFsw) amounted to 209 s (r= 0.015 s?1). Regarding the average residence time in the full scale filters of 700 s, applying AOP in front of the filters could be an interesting alternative which makes a separate decomposition installation superfluous, on the condition that the primary functions of the filters are not affected.","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":"8 1","pages":"3-8"},"PeriodicalIF":0.0,"publicationDate":"2015-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71222715","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 Preface: CCWI 2013 by B. Brunone et al. (2014), a mistake has been corrected. Please see the corrected text in the paragraph below. Next editions of CCWI and Water Distribution Systems Analysis (WDSA) Conferences have been already planned by the relevant Committees (probably the most organized non-formal groups!): WDSA2015 in Austin (TX), CCWI2015 in Leicester (UK), WDSA2016 in Cartagena de Indias (CO), CCWI2016 in Amsterdam (NL), CCWI2017 in Sheffield (UK), and WDSA2018 and CCWI2018 as a joint conference. The CCWI Standing Committee involves Dragan Savic and Zoran Kapelan (University of Exeter), Joby Boxall (University of Sheffield), and Bogumil Ulanicki (De Montfort University). The WDSA Standing Committee within EWRI (Environmental and Water Research Institute) is chaired by Dominic Boccelli (University of Cincinnati), with Morris Maslia (Agency for Toxic Substances and Disease Registry, Atlanta, Georgia) as Vice Chair, J. E. (Kobus) van Zyl (University of Cape Town, South Africa) as Secretary, and Avi Ostfeld (Technion, Haifa, Israel), as Past Chair.
B. Brunone et al.(2014)在前言:CCWI 2013中更正了一个错误。请参阅下面一段的更正文本。CCWI和供水系统分析(WDSA)会议的下一届会议已经由相关委员会(可能是最有组织的非正式团体!)计划:奥斯汀(德克萨斯州)的WDSA2015，莱斯特(英国)的CCWI2015，卡塔赫纳(CO)的WDSA2016，阿姆斯特丹(NL)的CCWI2016，谢菲尔德(英国)的CCWI2017以及WDSA2018和CCWI2018作为联合会议。CCWI常务委员会成员包括来自埃克塞特大学的Dragan Savic和Zoran Kapelan，来自谢菲尔德大学的Joby Boxall和来自德蒙特福德大学的Bogumil Ulanicki。EWRI(环境与水研究所)内的WDSA常务委员会由Dominic Boccelli(辛辛那提大学)担任主席，Morris Maslia(乔治亚州亚特兰大有毒物质和疾病登记处)担任副主席，J. E. (Kobus) van Zyl(南非开普敦大学)担任秘书，Avi Ostfeld(以色列海法理工学院)担任前任主席。
{"title":"Corrigendum to \"Preface: CCWI 2013\" published in Drink. Water Eng. Sci., 7, 99–100, 2014","authors":"B. Brunone, M. Ferrante, S. Meniconi, L. Berardi","doi":"10.5194/DWES-8-1-2015","DOIUrl":"https://doi.org/10.5194/DWES-8-1-2015","url":null,"abstract":"In the Preface: CCWI 2013 by B. Brunone et al. (2014), a mistake has been corrected. Please see the corrected text in the paragraph below. Next editions of CCWI and Water Distribution Systems Analysis (WDSA) Conferences have been already planned by the relevant Committees (probably the most organized non-formal groups!): WDSA2015 in Austin (TX), CCWI2015 in Leicester (UK), WDSA2016 in Cartagena de Indias (CO), CCWI2016 in Amsterdam (NL), CCWI2017 in Sheffield (UK), and WDSA2018 and CCWI2018 as a joint conference. The CCWI Standing Committee involves Dragan Savic and Zoran Kapelan (University of Exeter), Joby Boxall (University of Sheffield), and Bogumil Ulanicki (De Montfort University). The WDSA Standing Committee within EWRI (Environmental and Water Research Institute) is chaired by Dominic Boccelli (University of Cincinnati), with Morris Maslia (Agency for Toxic Substances and Disease Registry, Atlanta, Georgia) as Vice Chair, J. E. (Kobus) van Zyl (University of Cape Town, South Africa) as Secretary, and Avi Ostfeld (Technion, Haifa, Israel), as Past Chair.","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":"8 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2015-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71222218","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}
Since 1991 “Computing and Control for the Water Industry – CCWI” is a well-established series of bi-annual meetings. On 2–4 September 2013, the 12th edition (CCWI2013) was held in Perugia (Italy) and was focused on Information for Water Systems and Smart Cities. CCWI2013 emphasized the integration between the more conventional themes of the analysis and planning of water systems and information technology. Such an integration offers opportunities for design solutions and innovative models for the challenging problems of water system management in an urban perspective, a key concept for smart cities (Brunone and Giustolisi, 2014). The large number of presentations – more than 200 with many young researchers from Europe and overseas – confirmed the interest for CCWI2013 themes and the increasing success of CCWI Conferences (Fig. 1). This CCWI2013 special issue contains a selection of extended CCWI2013 papers which give a taste of the Proceedings of the Conference published on Procedia Engineering Elsevier (www.sciencedirect.com/science/journal/ 18777058/70). In fact their topics range from sustainabilitybased indicators of the urban water systems (Behzadian et al., 2014), design and control parameters in water treatment (Ramphal and Sibiya, 2014), numerical simulation of the transition between surface and pressurized flow (Fernandez-Pato and Garcia-Navarro, 2014) to optimisation of pump and valve schedules in complex large-scale water distribution networks (Skworcow et al., 2014), and a real data-based model to simulate the behavior of a pumping station equipped with variable speed pumps (Capponi et al., 2014). Figure 1. Last nine editions of CCWI conferences: number of papers published in the proceedings (from Brunone and Giustolisi, 2014).
{"title":"Preface: CCWI 2013","authors":"B. Brunone, M. Ferrante, S. Meniconi, L. Berardi","doi":"10.5194/DWES-7-99-2014","DOIUrl":"https://doi.org/10.5194/DWES-7-99-2014","url":null,"abstract":"Since 1991 “Computing and Control for the Water Industry – CCWI” is a well-established series of bi-annual meetings. On 2–4 September 2013, the 12th edition (CCWI2013) was held in Perugia (Italy) and was focused on Information for Water Systems and Smart Cities. CCWI2013 emphasized the integration between the more conventional themes of the analysis and planning of water systems and information technology. Such an integration offers opportunities for design solutions and innovative models for the challenging problems of water system management in an urban perspective, a key concept for smart cities (Brunone and Giustolisi, 2014). The large number of presentations – more than 200 with many young researchers from Europe and overseas – confirmed the interest for CCWI2013 themes and the increasing success of CCWI Conferences (Fig. 1). This CCWI2013 special issue contains a selection of extended CCWI2013 papers which give a taste of the Proceedings of the Conference published on Procedia Engineering Elsevier (www.sciencedirect.com/science/journal/ 18777058/70). In fact their topics range from sustainabilitybased indicators of the urban water systems (Behzadian et al., 2014), design and control parameters in water treatment (Ramphal and Sibiya, 2014), numerical simulation of the transition between surface and pressurized flow (Fernandez-Pato and Garcia-Navarro, 2014) to optimisation of pump and valve schedules in complex large-scale water distribution networks (Skworcow et al., 2014), and a real data-based model to simulate the behavior of a pumping station equipped with variable speed pumps (Capponi et al., 2014). Figure 1. Last nine editions of CCWI conferences: number of papers published in the proceedings (from Brunone and Giustolisi, 2014).","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":"7 1","pages":"99-100"},"PeriodicalIF":0.0,"publicationDate":"2014-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71222095","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}
C. Capponi, M. Ferrante, M. Pedroni, B. Brunone, S. Meniconi, M. Zaghini, F. Leoni
Abstract. Pump speed, input power, pressure and discharge data are analyzed for evaluating functioning conditions of Casale pumping station in Mantova, Italy, managed by TeaAcque. A model based on the affinity laws is used to simulate the behavior of the installed variable speed pumps. Quadratic and cubic polynomial curves are used to fit the pump data given by the affinity laws. Such curves allow predicting the efficiency when the functioning conditions change. The relationship between the rotation speed and the efficiency is also derived.
{"title":"Functioning conditions of the Casale pumping station in Mantova, Italy","authors":"C. Capponi, M. Ferrante, M. Pedroni, B. Brunone, S. Meniconi, M. Zaghini, F. Leoni","doi":"10.5194/DWES-7-93-2014","DOIUrl":"https://doi.org/10.5194/DWES-7-93-2014","url":null,"abstract":"Abstract. Pump speed, input power, pressure and discharge data are analyzed for evaluating functioning conditions of Casale pumping station in Mantova, Italy, managed by TeaAcque. A model based on the affinity laws is used to simulate the behavior of the installed variable speed pumps. Quadratic and cubic polynomial curves are used to fit the pump data given by the affinity laws. Such curves allow predicting the efficiency when the functioning conditions change. The relationship between the rotation speed and the efficiency is also derived.","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":"42 1","pages":"93-97"},"PeriodicalIF":0.0,"publicationDate":"2014-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71222044","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 most commonly used hydraulic network models used in the drinking water community exclusively consider fully filled pipes. However, water flow numerical simulation in urban pipe systems may require to model transitions between surface flow and pressurized flow in steady and transient situations. The governing equations for both flow types are different and this must be taken into account in order to get a complete numerical model for solving dynamically transients. In this work, a numerical simulation tool is developed, capable of simulating pipe networks mainly unpressurized, with isolated points of pressurization. For this purpose, the mathematical model is reformulated by means of the Preissmann slot method. This technique provides a reasonable estimation of the water pressure in cases of pressurization. The numerical model is based on the first order Roe's scheme, in the frame of finite volume methods. The novelty of the method is that it is adapted to abrupt transient situations, with subcritical and supercritical flows. The validation has been done by means of several cases with analytic solutions or empirical laboratory data. It has also been applied to some more complex and realistic cases, like junctions or pipe networks.
{"title":"Finite volume simulation of unsteady water pipe flow","authors":"J. Fernández-Pato, P. García-Navarro","doi":"10.5194/DWES-7-83-2014","DOIUrl":"https://doi.org/10.5194/DWES-7-83-2014","url":null,"abstract":"Abstract. The most commonly used hydraulic network models used in the drinking water community exclusively consider fully filled pipes. However, water flow numerical simulation in urban pipe systems may require to model transitions between surface flow and pressurized flow in steady and transient situations. The governing equations for both flow types are different and this must be taken into account in order to get a complete numerical model for solving dynamically transients. In this work, a numerical simulation tool is developed, capable of simulating pipe networks mainly unpressurized, with isolated points of pressurization. For this purpose, the mathematical model is reformulated by means of the Preissmann slot method. This technique provides a reasonable estimation of the water pressure in cases of pressurization. The numerical model is based on the first order Roe's scheme, in the frame of finite volume methods. The novelty of the method is that it is adapted to abrupt transient situations, with subcritical and supercritical flows. The validation has been done by means of several cases with analytic solutions or empirical laboratory data. It has also been applied to some more complex and realistic cases, like junctions or pipe networks.","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":"7 1","pages":"83-92"},"PeriodicalIF":0.0,"publicationDate":"2014-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71221955","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 size and structural characteristics of floc particles are important design and control parameters in water treatment and should be rapidly monitored with a reasonable amount of accuracy. In this study, a photometric dispersion analyser (PDA) coupled to standard jar test experiments was used to optimize coagulation-flocculation parameters while monitoring floc size and structure as well as the rate of floc formation during coagulation using alum. The optimal coagulation conditions were as follows: sample pH 8; alum dosage, 3 mg L−1 as Al3+; G value, 172 s−1; rapid mixing time, 20 s. These conditions resulted in unstable treated water having a calcium carbonate precipitation potential (CCPP) of −15 mg L−1 as CaCO3 and required a slaked lime dosage of 17 mg L−1 as CaCO3 to equilibrate CCPP to acceptable levels. PDA data revealed that aggregation rate and steady-state variance are primary parameters as both have substantial influence on coagulation-flocculation efficiency. However, the average steady state ratio, although an important parameter, had a lessened impact on coagulation-flocculation efficiency. The results of this study showed that the PDA instrument is an important tool in coagulation kinetic studies and can be employed as an additional tool in the optimization of coagulation conditions.
{"title":"Optimization of coagulation-flocculation parameters using a photometric dispersion analyser","authors":"S. Ramphal, M. Sibiya","doi":"10.5194/DWES-7-73-2014","DOIUrl":"https://doi.org/10.5194/DWES-7-73-2014","url":null,"abstract":"Abstract. The size and structural characteristics of floc particles are important design and control parameters in water treatment and should be rapidly monitored with a reasonable amount of accuracy. In this study, a photometric dispersion analyser (PDA) coupled to standard jar test experiments was used to optimize coagulation-flocculation parameters while monitoring floc size and structure as well as the rate of floc formation during coagulation using alum. The optimal coagulation conditions were as follows: sample pH 8; alum dosage, 3 mg L−1 as Al3+; G value, 172 s−1; rapid mixing time, 20 s. These conditions resulted in unstable treated water having a calcium carbonate precipitation potential (CCPP) of −15 mg L−1 as CaCO3 and required a slaked lime dosage of 17 mg L−1 as CaCO3 to equilibrate CCPP to acceptable levels. PDA data revealed that aggregation rate and steady-state variance are primary parameters as both have substantial influence on coagulation-flocculation efficiency. However, the average steady state ratio, although an important parameter, had a lessened impact on coagulation-flocculation efficiency. The results of this study showed that the PDA instrument is an important tool in coagulation kinetic studies and can be employed as an additional tool in the optimization of coagulation conditions.","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":"7 1","pages":"73-82"},"PeriodicalIF":0.0,"publicationDate":"2014-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5194/DWES-7-73-2014","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71222306","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. This paper considers optimisation of pump and valve schedules in complex large-scale water distribution networks (WDN), taking into account pressure aspects such as minimum service pressure and pressure-dependent leakage. An optimisation model is automatically generated in the GAMS language from a hydraulic model in the EPANET format and from additional files describing operational constraints, electricity tariffs and pump station configurations. The paper describes in details how each hydraulic component is modelled. To reduce the size of the optimisation problem the full hydraulic model is simplified using module reduction algorithm, while retaining the nonlinear characteristics of the model. Subsequently, a nonlinear programming solver CONOPT is used to solve the optimisation model, which is in the form of Nonlinear Programming with Discontinuous Derivatives (DNLP). The results produced by CONOPT are processed further by heuristic algorithms to generate integer solution. The proposed approached was tested on a large-scale WDN model provided in the EPANET format. The considered WDN included complex structures and interactions between pump stations. Solving of several scenarios considering different horizons, time steps, operational constraints, demand levels and topological changes demonstrated ability of the approach to automatically generate and solve optimisation problems for a variety of requirements.
{"title":"Pump schedules optimisation with pressure aspects in complex large-scale water distribution systems","authors":"P. Skworcow, Daniel Paluszczyszyn, B. Ulanicki","doi":"10.5194/DWES-7-53-2014","DOIUrl":"https://doi.org/10.5194/DWES-7-53-2014","url":null,"abstract":"Abstract. This paper considers optimisation of pump and valve schedules in complex large-scale water distribution networks (WDN), taking into account pressure aspects such as minimum service pressure and pressure-dependent leakage. An optimisation model is automatically generated in the GAMS language from a hydraulic model in the EPANET format and from additional files describing operational constraints, electricity tariffs and pump station configurations. The paper describes in details how each hydraulic component is modelled. To reduce the size of the optimisation problem the full hydraulic model is simplified using module reduction algorithm, while retaining the nonlinear characteristics of the model. Subsequently, a nonlinear programming solver CONOPT is used to solve the optimisation model, which is in the form of Nonlinear Programming with Discontinuous Derivatives (DNLP). The results produced by CONOPT are processed further by heuristic algorithms to generate integer solution. The proposed approached was tested on a large-scale WDN model provided in the EPANET format. The considered WDN included complex structures and interactions between pump stations. Solving of several scenarios considering different horizons, time steps, operational constraints, demand levels and topological changes demonstrated ability of the approach to automatically generate and solve optimisation problems for a variety of requirements.","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":"7 1","pages":"53-62"},"PeriodicalIF":0.0,"publicationDate":"2014-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71222328","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}
K. Behzadian, Z. Kapelan, G. Venkatesh, H. Brattebø, S. Sægrov
Abstract. This paper presents the "WaterMet2" model for long-term assessment of urban water system (UWS) performance which will be used for strategic planning of the integrated UWS. WaterMet2 quantifies the principal water-related flows and other metabolism-based fluxes in the UWS such as materials, chemicals, energy and greenhouse gas emissions. The suggested model is demonstrated through sustainability-based assessment of an integrated real-life UWS for a daily time-step over a 30-year planning horizon. The integrated UWS modelled by WaterMet2 includes both water supply and wastewater systems. Given a rapid population growth, WaterMet2 calculates six quantitative sustainability-based indicators of the UWS. The result of the water supply reliability (94%) shows the need for appropriate intervention options over the planning horizon. Five intervention strategies are analysed in WaterMet2 and their quantified performance is compared with respect to the criteria. Multi-criteria decision analysis is then used to rank the intervention strategies based on different weights from the involved stakeholders' perspectives. The results demonstrate that the best and robust strategies are those which improve the performance of both water supply and wastewater systems.
{"title":"WaterMet2 : A tool for integrated analysis of sustainability-based performance of urban water systems","authors":"K. Behzadian, Z. Kapelan, G. Venkatesh, H. Brattebø, S. Sægrov","doi":"10.5194/DWES-7-63-2014","DOIUrl":"https://doi.org/10.5194/DWES-7-63-2014","url":null,"abstract":"Abstract. This paper presents the \"WaterMet2\" model for long-term assessment of urban water system (UWS) performance which will be used for strategic planning of the integrated UWS. WaterMet2 quantifies the principal water-related flows and other metabolism-based fluxes in the UWS such as materials, chemicals, energy and greenhouse gas emissions. The suggested model is demonstrated through sustainability-based assessment of an integrated real-life UWS for a daily time-step over a 30-year planning horizon. The integrated UWS modelled by WaterMet2 includes both water supply and wastewater systems. Given a rapid population growth, WaterMet2 calculates six quantitative sustainability-based indicators of the UWS. The result of the water supply reliability (94%) shows the need for appropriate intervention options over the planning horizon. Five intervention strategies are analysed in WaterMet2 and their quantified performance is compared with respect to the criteria. Multi-criteria decision analysis is then used to rank the intervention strategies based on different weights from the involved stakeholders' perspectives. The results demonstrate that the best and robust strategies are those which improve the performance of both water supply and wastewater systems.","PeriodicalId":53581,"journal":{"name":"Drinking Water Engineering and Science","volume":"39 1","pages":"63-72"},"PeriodicalIF":0.0,"publicationDate":"2014-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71222267","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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