Chlorine-age based booster chlorination optimization in water distribution network considering the uncertainty of residuals

2018 ◽  
Vol 19 (3) ◽  
pp. 796-807
Author(s):  
Kunlun Xin ◽  
Xiao Zhou ◽  
Hao Qian ◽  
Hexiang Yan ◽  
Tao Tao

Abstract Booster chlorination has been applied by many utilities for better chlorine-residual maintenance. In this paper, a new water-age based method for optimal location and dosage of booster disinfection has been proposed, as well as an uncertainty analysis of chlorine residuals. Chlorine-age, a novel indicator of water quality, is firstly introduced based on water age. By minimizing the total chlorine-age of nodes in a water distribution network (WDN), a new model for optimal booster location is proposed. The chlorine-age based model is independent of chlorine-decay simulation, and therefore avoids the complexity of obtaining kinetic parameters and prevents misleading results caused by inaccurate simulation of chlorine residuals. The uncertainties of chlorine residuals increase along with the distance and time consumption for delivering water. In this study, chlorine-age is employed to measure the uncertainties of nodal residuals, and optimal chlorine dosage is calculated considering the uncertainties. The proposed method has been tested on an example network and a real-life network to illustrate its validity and applicability. The results have shown that the method is feasible and reliable in practical application.

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2141
Author(s):  
Stavroula Tsitsifli ◽  
Vasilis Kanakoudis

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.


2011 ◽  
Vol 11 (4-5) ◽  
pp. 731-747 ◽  
Author(s):  
MASSIMILIANO CATTAFI ◽  
MARCO GAVANELLI ◽  
MADDALENA NONATO ◽  
STEFANO ALVISI ◽  
MARCO FRANCHINI

AbstractThis paper presents a new application of logic programming to a real-life problem in hydraulic engineering. The work is developed as a collaboration of computer scientists and hydraulic engineers, and applies Constraint Logic Programming to solve a hard combinatorial problem. This application deals with one aspect of the design of a water distribution network, i.e., the valve isolation system design. We take the formulation of the problem by Giustolisi and Savić (2008 Optimal design of isolation valve system for water distribution networks. InProceedings of the 10th Annual Water Distribution Systems Analysis Conference WDSA2008, J. Van Zyl, A. Ilemobade, and H. Jacobs, Eds.) and show how, thanks to constraint propagation, we can get better solutions than the best solution known in the literature for the Apulian distribution network. We believe that the area of the so-calledhydroinformaticscan benefit from the techniques developed in Constraint Logic Programming and possibly from other areas of logic programming, such as Answer Set Programming.


2019 ◽  
Vol 2 (1) ◽  
pp. 11 ◽  
Author(s):  
Arif Susanto ◽  
Purwanto Purwanto ◽  
Agus Hadiyarto

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.


Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 278 ◽  
Author(s):  
Stavroula Chatzivasili ◽  
Katerina Papadimitriou ◽  
Vasilis Kanakoudis

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.


2011 ◽  
Vol 13 (3) ◽  
pp. 390-400 ◽  
Author(s):  
Kui Chang ◽  
Jin Liang Gao ◽  
Wen Yan Wu ◽  
Yi Xing Yuan

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.


Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 601 ◽  
Author(s):  
Stavroula Chatzivasili ◽  
Katerina Papadimitriou ◽  
Vasilis Kanakoudis ◽  
Menelaos Patelis

In the last three decades, the need of achieving a reliable water distribution system has become more eminent for both the consumer’s satisfaction and the efficient management of water sources. The purpose of this paper is to provide an optimal separation of a water distribution network (WDN) into District Metered Areas (DMAs) in order to ensure that the delivered water is of proper age and pressure. At first, the water distribution network is divided into smaller areas via the method of Geometric Partitioning, which is based on Recursive Coordinate Bisection (RCB). Subsequently, Gaussian Mixture Modelling (GMM) solution is applied, obtaining an optimal placement of isolation valves and separation of the WDN into DMAs. The performance of the proposed system is evaluated on two different networks and is compared against the Genetic Algorithm (GA) tool, constituting a very promising approach, especially for sizeable water distribution networks due to the diminished running time and the noteworthy reduction of pressure and water age.


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