scholarly journals Water quality comprehensive evaluation method for large water distribution network based on clustering analysis

2011 ◽  
Vol 13 (3) ◽  
pp. 390-400 ◽  
Author(s):  
Kui Chang ◽  
Jin Liang Gao ◽  
Wen Yan Wu ◽  
Yi Xing Yuan
Keyword(s):  
Water Quality ◽  
Quality Indicators ◽  
Water Distribution ◽  
Comprehensive Evaluation ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Residual Chlorine ◽  
Clustering Methods ◽  
Water Age ◽  
Water Quality Indicators

In order to evaluate water quality for a large water distribution network comprehensively, a two-stage classification method was used and the clustering methods, self-organizing map (SOM), K-means method and fuzzy c-mean (FCM), were represented. With these clustering methods, the pipes of a large real water distribution network were divided into some groups considering one or more water quality indicators synchronously. The water quality indicators of residual chlorine, water age, THMs, TAAs, TOC and BDOC are used in this paper. Residual chlorine and water age are two main water quality indicators. THMs and TAAs can represents the disinfection byproducts information. And TOC and BDOC are used to represents biological stability. According to the clustering results, the status of water quality of the water network was analysed. The results showed that the classification of SOM could express the comprehensive water quality in a water distribution network (WDN) directly and vividly by high-dimension water quality indicator projection to a low dimensional topology grid and that two-stage classification method has higher efficiency in comparison to the traditional clustering method. Water quality comprehensive evaluation was of significance for locating water quality monitoring, water network rehabilitation and expansion.

scholarly journals ANALISIS KUALITAS AIR UNTUK KONSENTRASI FLUORIDE PADA SISTEM JARINGAN DISTRIBUSI AIR MINUM DENGAN FLUORIDASI

2019 ◽  
Vol 2 (1) ◽  
pp. 11 ◽  
Author(s):  
Arif Susanto ◽  
Purwanto Purwanto ◽  
Agus Hadiyarto
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Distribution ◽  
Dental Health ◽  
Distribution Network ◽  
Fluoride Concentration ◽  
Water Distribution Network ◽  
Water Supply Systems ◽  
Water Age ◽  
Drinking Water Distribution

Abstract:. The requirement of consumed drinking water so that it does not create disturbance to public health is that it needs a quality monitoring. Water fluoridation in Tembagapura City aims to reach its concentration level toward certain safe level, and it can provide maximum benefits for dental health. Analysis and simulation methods using EPAnet software. The results of hydrolic simulation and water quality for fluoride concentration of each node and link in the drinking water distribution network system have changed in every time change following the drinking water distribution segment. From hydraulic simulations, especially for head and flow at separate points, it consists of simultaneous solution in flow equivalence for every junction and headloss relationship in every link of network as a result of hydraulic balancing. New segment will be made at the end of each link that receives inflow from a node if the quality of the new node is different from the link in the last segment. Every pipe in network contains singular segment where the water quality is in line with the preliminary quality stated in the preliminary node. With the availability of hydraulic model and water quality for fluoride concentration, a further research can be conducted for chlorine decay, growth of by product i.e. Trihalomethans (THMs) as well as water age simultaneously in drinking water supply systems in Tembagapura City.  Keyword: EPAnet, distribution network, fluoride concentration. Abstrak: Persyaratan kualitas air minum yang dikonsumsi masyarakat agar tidak menimbulkan gangguan kesehatan, maka penyelenggara air minum perlu melakukan pemantauan kualitasnya. Fluoridasi air di Kota Tembagapura ditujukan untuk mencapai tingkat konsentrasi fluoride pada level tertentu yang aman dan dapat memberikan manfaat maksimal bagi kesehatan gigi. Metode analisis dan simulasi menggunakan perangkat lunak EPAnet. Hasil simulasi hidrolis dan kualitas air untuk konsentrasi fluoride pada setiap node dan link pada sistem jaringan distribusi air minum berubah pada setiap perubahan waktu mengikuti segmen distribusi air minum tersebut. Dari simulasi hidrolis, khusus untuk head dan aliran pada titik yang terpisah meliputi penyelesaian secara simultan dalam persamaan aliran untuk tiap sambungan (junction), dan hubungan headloss pada setiap link pada jaringan sebagai akibat dari hydrolic balancing. Segmen baru terbentuk pada akhir dari setiap link yang menerima inflow dari sebuah node, jika kualitas node baru berbeda dari link pada segmen terakhir. Setiap pipa dalam jaringan mengandung segmen tunggal, di mana kualitas air sebanding dengan kualitas awal yang ditetapkan di node awal. Dengan tersedianya model hidrolis dan kualitas air untuk konsentrasi fluoride, maka dapat dilakukan penelitian lanjutan untuk peluruhan klorin, pertumbuhan by product yaitu trihalomethans (THMs) serta usia air secara simultan pada sistem penyediaan air minum di Kota Tembagapura.Kata Kunci: EPAnet, jaringan distribusi, konsentrasi fluoride.

scholarly journals Operational and technical performance of a water distribution network in Oman

2021 ◽  
Author(s):  
Ahmed Al Naamani ◽  
Ahmad Sana
Keyword(s):  
Water Quality ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Capital City ◽  
Operational Performance ◽  
Residual Chlorine ◽  
Quality Performance ◽  
Urban Networks ◽  
Technical Performance

Abstract A water distribution network in an urban area in Muscat region (capital city of Oman) is assessed for operational performance using the widely accepted methodology proposed by International Water Association (IWA). The technical performance of this network was assessed using global performance index methods after modifying the performance levels as per local guidelines. A total of 37 operational performance indicators for the network were selected to carryout assessment. Overall operational performance showed high scores whereas some indicators showed unacceptable performance values. The network showed very high technical performance considering nodal pressures. The lower performance for pipe velocity may be attributed to the fact that the network is currently being utilized by 70% of the population for which it was designed. The residual chlorine levels were within the acceptable range of the Public Authority for Water (PAW) showing a very good performance by virtue of water quality. This study will be useful for the decision makers to assess the operational, technical and water quality performance of urban networks and take actions for improvements.

scholarly journals Assessing the Impact of DMAs and the Use of Boosters on Chlorination in a Water Distribution Network in Greece

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2141
Author(s):  
Stavroula Tsitsifli ◽  
Vasilis Kanakoudis
Keyword(s):  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Assessment Process ◽  
Water Volume ◽  
Pressure Management ◽  
Water Age ◽  
Chlorination Process ◽  
Management Measures ◽  
The Impact

Disinfection is one of the most important water treatment processes as it inactivates pathogens providing safe drinking water to the consumers. A fresh-water distribution network is a complex system where constant monitoring of several parameters and related managerial decisions take place in order for the network to operate in the most efficient way. However, there are cases where some of the decisions made to improve the network’s performance level, such as reduction of water losses, may have negative impacts on other significant operational processes such as the disinfection. In particular, the division of a water distribution network into district metered areas (DMAs) and the application of various pressure management measures may impact the effectiveness of the water chlorination process. Two operational measures are assessed in this paper: (a) the use of inline chlorination boosters to achieve more efficient chlorination; and (b) how the DMAs formation impacts the chlorination process. To achieve this, the water distribution network of a Greek town is chosen as a case study where several scenarios are being thoroughly analyzed. The assessment process utilizes the network’s hydraulic simulation model, which is set up in Watergems V8i software, forming the baseline to develop the network’s water quality model. The results proved that inline chlorination boosters ensure a more efficient disinfection, especially at the most remote parts/nodes of the network, compared to conventional chlorination processes (e.g., at the water tanks), achieving 100% safe water volume and consuming almost 50% less chlorine mass. DMAs’ formation results in increased water age values up to 8.27%, especially at the remote parts/nodes of the network and require more time to achieve the necessary minimum effective chlorine concentration of 0.2 mg/L. However, DMAs formation and pressure management measures do not threaten the chlorination’s efficiency. It is important to include water age and residual chlorine as criteria when optimizing water pressure and the division of DMAs.

Improving water age estimation in a drinking water distribution network by field study and digital modeling

2021 ◽  
Author(s):  
Jon Kristian Rakstang ◽  
Michael B. Waak ◽  
Marius M. Rokstad ◽  
Cynthia Hallé
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Network Model ◽  
Age Estimation ◽  
Water Distribution ◽  
Distribution Network ◽  
Distribution Networks ◽  
Plate Count ◽  
Water Age ◽  
Drinking Water Distribution

<p>Municipal drinking water distribution networks are complex and dynamic systems often spanning many hundreds of kilometers and serving thousands of consumers. Degradation of water quality within a distribution network can be associated to water age (i.e., time elapsed after treatment). Norwegian distribution networks often consist of an intricate combination of pressure zones, in which the transport path(s) between source and consumer is not easily ascertained. Water age is therefore poorly understood in many Norwegian distribution networks. In this study, simulations obtained from a water network model were used to estimate water age in a Norwegian municipal distribution network. A full-scale tracer study using sodium chloride salt was conducted to assess simulation accuracy. Water conductivity provided empirical estimates of salt arrival time at five monitoring stations. These estimates were consistently higher than simulated peak arrival times. Nevertheless, empirical and simulated water age correlated well, indicating that additional network model calibration will improve accuracy. Subsequently, simulated mean water age also correlated strongly with heterotrophic plate count (HPC) monitoring data from the distribution network (Pearson’s R= 0.78, P= 0.00046), indicating biomass accumulation during distribution—perhaps due to bacterial growth or biofilm interactions—and illustrating the importance of water age for water quality. This study demonstrates that Norwegian network models can be calibrated with simple and cost-effective salt tracer studies to improve water age estimates. Improved water age estimation will increase our understanding of water quality dynamics in distribution networks. This can, through digital tools, be used to monitor and control water age, and its impact on biogrowth in the network.</p>

scholarly journals Certainty Level of Water Delivery of the Required Quality by Water Supply Networks

2019 ◽  
Vol 16 (10) ◽  
pp. 1860 ◽  
Author(s):  
Marian Kwietniewski ◽  
Katarzyna Miszta-Kruk ◽  
Kaja Niewitecka ◽  
Mirosław Sudoł ◽  
Krzysztof Gaska
Keyword(s):  
Water Quality ◽  
Water Supply ◽  
Quality Indicators ◽  
Distribution System ◽  
Water Distribution ◽  
Water Delivery ◽  
Supply Networks ◽  
Water Quality Indicators ◽  
Water Supply Networks ◽  
Required Quality

The security of water delivery of the required quality by water supply networks is identified with the concept of reliability. Therefore, a method of reliability evaluation of water distribution of the required quality was developed. The method is based on the probabilistic character of secondary water contamination in the water supply network. Data for the method are taken from monitoring of the water distribution system. The method takes into consideration the number and locations of individual measurement points and the results of the tests of water quality indicators at these points. The sets of measurement points and water quality indicators constitute a matrix research (observation) field in the model. The proposed method was implemented to assess the reliability of a water distribution process with respect to water with the required microbiological quality indicators in a real distribution system.

Variabilities in the cost equivalency of decentralized treatment units designed to address network-derived water quality degradation

2006 ◽  
Vol 6 (4) ◽  
pp. 45-56
Author(s):  
J.W. Norton ◽  
W.J. Weber
Keyword(s):  
Water Quality ◽  
Water Distribution ◽  
Distribution Network ◽  
Treatment Plant ◽  
Water Distribution Network ◽  
Functional Requirements ◽  
Treatment Unit ◽  
Advantages And Disadvantages ◽  
Quality Degradation ◽  
The Cost

Factors impacting the cost equivalency point for deploying strategically-located treatment units within a distributed optimal technology network (DOT-Net) to manage network-derived water quality degradation are defined and quantified. The cost equivalency point is essentially the ‘breakeven’ allowable cost for implementing DOT-Net strategy as an alternative to upgrading a central treatment facility to ‘pretreat’ water sufficiently to manage quality degradation within a potable water distribution network. For the purposes of the analysis presented, water quality is assumed to degrade linearly with time as it flows through the distribution network. Disinfection by-product (DBP) formation, selected as a representative water quality degradation parameter, was modeled to predict service population DBP exposure and resulting cost of centralized treatment plant upgrades to meet water quality goals. The equivalency point was determined by apportioning the anticipated cost for upgrading the centralized treatment facilities over the fraction of service connections receiving deficient quality water. Both concentration of DBP precursor material and service population size are found to have limited impact on the equivalency point of a distributed treatment unit. The advantages and disadvantages of various treatment methods available for in-network water treatment are outlined and the ancillary functional requirements of the distributed treatment unit are delineated.

scholarly journals Appraisal of water quality indices for service reservoirs in water distribution networks

2020 ◽  
Vol 81 (8) ◽  
pp. 1606-1614 ◽  
Author(s):  
M. S. Nyirenda ◽  
T. T. Tanyimboh
Keyword(s):  
Water Quality ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Sampling Point ◽  
Quality Indices ◽  
Water Quality Indices ◽  
State Of Water ◽  
Pollution Loads

Abstract The use of water quality indices to aggregate pollution loads in rivers has been widely studied, with researchers using various sub-indices and aggregation methods. These have been used to combine various quality variables at a sampling point in a river into an overall water quality index to compare the state of water quality in different river reaches. Service reservoirs in a water distribution network, like rivers, have complex mixing mechanisms, are subjected to various water quality variables and are variably sized and sited. Water quality indices and the relevant sub-indices are formulated here and applied to service reservoirs within a water distribution network. This is in an attempt to compare holistically the performance of service reservoirs in solutions of optimisation algorithms with regards to water quality.

scholarly journals Evolutionary multi-objective optimization of the design and operation of water distribution network: total cost vs. reliability vs. water quality

2006 ◽  
Vol 8 (3) ◽  
pp. 165-179 ◽  
Author(s):  
Raziyeh Farmani ◽  
Godfrey Walters ◽  
Dragan Savic
Keyword(s):  
Water Quality ◽  
Residence Time ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Loading Conditions ◽  
Pump Operation ◽  
Total Cost ◽  
Multi Objective ◽  
Storage Facilities

An expanded rehabilitation of the hypothetical water distribution network of Anytown, USA is considered. As well as pipe rehabilitation decisions, tank sizing, tank siting and pump operation schedules are considered as design variables. Inclusion of pump operation schedules requires consideration of water system operation over the demand pattern period. Design of distribution storage facilities involves solving numerous issues and trade-offs such as locations, levels and volume. This paper investigates the application of multi-objective evolutionary algorithms in the identification of the pay-off characteristic between total cost, reliability and water quality of Anytown's water distribution system. A new approach is presented for formulation of the model. To provide flexibility, the network must be designed and operated under multiple loading conditions. The cost of the solution includes the capital costs of pipes and tanks as well as the present value of the energy consumed during a specified period. Optimization tends to reduce costs by reducing the diameter of, or completely eliminating, pipes, thus leaving the system with insufficient capacity to respond to pipe breaks or demands that exceed design values without violating required performance levels. Here a resilience index is considered as a second objective to increase the hydraulic reliability and the availability of water during pipe failures. Considering reliability as one of the objectives in the optimization process will decrease the level of vulnerability for the solutions and therefore will result in robust networks. However, oversized distribution mains and storage tanks will have adverse effects on water age with negative effects on water quality due to low flow velocity and little turnover, respectively. Therefore, another objective in the design and operation of distribution systems with storage facilities is the minimization of residence time, thus minimizing deterioration in water quality, which is directly associated with the age of water. Residence time must include not only the time in tanks but also the travel time before and after the water's entry into the storage facilities. The residence time of the water in the network is considered as a surrogate measure of water quality. Results are presented for the pay-off characteristics between total cost, reliability and water quality, for 24 h design and five loading conditions.

scholarly journals Optimizing the Formation of DMAs in a Water Distribution Network through Advanced Modelling

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 278 ◽  
Author(s):  
Stavroula Chatzivasili ◽  
Katerina Papadimitriou ◽  
Vasilis Kanakoudis
Keyword(s):  
Mixture Model ◽  
Water Distribution ◽  
Water Pressure ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Gaussian Mixture ◽  
Optimal Placement ◽  
Water Age ◽  
Optimal Separation ◽  
Student’S T

Water pressure management in a water distribution network (WDN) is a key component applied to achieve desirable water quality as well as a trouble-free operation of the network. This paper presents a hybrid, two-stage approach, to provide optimal separation of a WDN into District Metered Areas (DMAs), improving both water age and pressure. The first stage aims to divide the WDN into smaller areas via the Geometric Partitioning method, which is based on Recursive Coordinate Bisection (RCB). Subsequently, the Student’s t-mixture model (SMM) is applied to each area, providing an optimal placement of isolation valves and separating the network in DMAs. The model is evaluated on a realistic network generated through Watergems and is compared against one variation of it implemented, including the Gaussian Mixture Model (GMM) as well as the Genetic Algorithm (GA) approach, obtaining impressive performance. The implementation of both stages was deployed in a MATLAB environment through the Epanet toolkit. The proposed system is very promising, especially for large size WDNs due to the decreased running time and noteworthy reduction of pressure and water age.

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