scholarly journals Monitoring Residual Chlorine Decay and Coliform Contamination in Water Distribution Network of Kampala, Uganda

2011 ◽  
Vol 15 (1) ◽  
Author(s):  
J Ecura ◽  
J Okot-Okumu ◽  
TO Okurut
Keyword(s):  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Residual Chlorine ◽  
Chlorine Decay

scholarly journals Residual Chlorine Decay in Juja Water Distribution Network using EPANET Model

2019 ◽  
Vol 9 (1) ◽  
pp. 332-334 ◽  
Keyword(s):  
Water Distribution ◽  
Distribution Network ◽  
Treatment Plant ◽  
Water Distribution Network ◽  
Residual Chlorine ◽  
Simulation Tool ◽  
First Order ◽  
Water Company ◽  
Field Samples ◽  
Chlorine Decay

The current study was carried out to analyze the residual chlorine decay analysis within the existing Juja water distribution network. The study used EPANET as a simulation tool. From the field samples, the first-order bulk decay coefficient Kb was found equal to - 0.04 . The wall coefficient Kw was assumed to - 4.0 mg/ /day as guided by literature. The analysis shows that the entire supply area of the existing distribution network faces higher residual chlorine concentration (0.70 to 0.8 mg/l) from 9 am. The study recommended the reducing of the initial chlorine added at the treatment plant and the optimization of the network, which will provide a proper residual chlorine dosage to reduce Juja consumers exposure to health risk and also to be economically reasonable for the water company in charge

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.

Application of Artificial Neural Network for Reducing of Chlorine Residual Concentration in Water Distribution Network

2008 ◽  
Vol 3 (2) ◽  
Author(s):  
Jayong Koo ◽  
Toyono Inakazu ◽  
Akira Koizumi ◽  
Yasuhiro Arai ◽  
Kyoungpil Kim ◽  
...  
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Residual Chlorine ◽  
Trial And Error ◽  
Ann Model ◽  
Residual Concentration ◽  
Dead End

It is difficult to estimate residual chlorine at the dead-end area of the water distribution network because chlorine consumption is influenced by various factors. Therefore, there are many water utilities that control the amounts of chlorine in reservoirs using empirical trial-and-error methods to maintain safe levels of residual chlorine in the distribution system. In this study, an ANN model of residual chlorine concentration is proposed which could be used to reduce in chlorine use in water distribution system. The ANN model with best performance was selected by training and verification. The five scenarios for the reduction in chlorine use were analyzed by setting the input chlorine as low as 0.05~0.25 mg/L compared with the input chlorine observed in the time series. Case 4 is the best to be satisfied with the input condition (0.4 mg/L or more) and output condition (0.34 mg/L or more) at the same time. It is possible to reduce chlorine in use up to 0.2 mg/L in the maximum amount.

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 Forming DMAs in a water distribution network considering the operating pressure and the chlorine residual concentration as the design parameters

2017 ◽  
Vol 19 (6) ◽  
pp. 900-910 ◽  
Author(s):  
Konstantinos Gonelas ◽  
Apostolos Chondronasios ◽  
Vasilis Kanakoudis ◽  
Menelaos Patelis ◽  
Panagiota Korkana
Keyword(s):  
Water Distribution ◽  
Optimal Allocation ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Disinfection Byproducts ◽  
Design Parameters ◽  
Residual Chlorine ◽  
Operating Pressure ◽  
Water Losses ◽  
Residual Concentration

Abstract Dividing a water distribution network (WDN) in the optimal district metered areas (DMAs) formation is one task that usually troubles water utility managers. The present paper utilizes optimization methods to achieve desired segmentation conditions in terms of (a) operating pressure reduction, thus reducing the system's real water losses and (b) residual chlorine concentration reduction thus preventing disinfection byproducts' growth. Exploiting the numerous possibilities offered by the inter-connection of Matlab and EPANET software tools, an algorithm is developed in C++ language. The algorithm reads all significant data of a WDN as an output of EPANET. The first algorithm calculates the optimal allocation of a given number of closed isolation valves in terms of water losses' reduction, considering restrictions for network's proper operation. The second algorithm calculates the optimal formation of DMAs in terms of water quality improvement. Both algorithms can be applied in any WDN. The outcome is the optimal set of closed pipes that leads to the optimal formation of DMAs in a given network. The closing of pipes (by installing isolation valves) determines the optimal formation of DMAs. The basic concept of both algorithms and their application in a case study network's hydraulic model are presented.

scholarly journals Modeling of residual chlorine in a drinking water network in times of pandemic of the SARS-CoV-2 (COVID-19)

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Fernando García-Ávila ◽  
Alex Avilés-Añazco ◽  
Juan Ordoñez-Jara ◽  
Christian Guanuchi-Quezada ◽  
Lisveth Flores del Pino ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Decay Rates ◽  
Residual Chlorine ◽  
The Novel ◽  
Drinking Water Distribution ◽  
Reaction Constant ◽  
Novel Coronavirus

AbstractDue to the outbreak of the novel coronavirus disease there is a need for public water supply of the highest quality. Adequate levels of chlorine allow immediate elimination of harmful bacteria and viruses and provide a protective residual throughout the drinking water distribution network (DWDN). Therefore, a residual chlorine decay model was developed to predict chlorine levels in a real drinking water distribution network. The model allowed determining human exposure to drinking water with a deficit of residual chlorine, considering that it is currently necessary for the population to have clean water to combat coronavirus Covid 19. The chlorine bulk decay rates (kb) and the reaction constant of chlorine with the pipe wall (kw) were experimentally determined. Average kb and kw values of 3.7 d− 1 and 0.066 m d− 1 were obtained, respectively. The values of kb and kw were used in EPANET to simulate the chlorine concentrations in a DWDN. The residual chlorine concentrations simulated by the properly calibrated and validated model were notably close to the actual concentrations measured at different points of the DWDN. The results showed that maintaining a chlorine concentration of 0.87 mg L− 1 in the distribution tank, the residual chlorine values in the nodes complied with the Ecuadorian standard (0.3 mg L− 1); meanwhile, about 45% of the nodes did not comply with what is recommended by the WHO as a mechanism to combat the current pandemic (0.5 mg L− 1). This study demonstrated that residual chlorine modeling is a valuable tool for monitoring water quality in the distribution network, allowing to control residual chlorine levels in this pandemic season.

scholarly journals Simulation of Pressure Head and Chlorine Decay in a Water Distribution Network: A Case Study

2019 ◽  
Vol 13 (1) ◽  
pp. 58-68
Author(s):  
M. O. A. Alsaydalani
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Distribution Network ◽  
Extended Period ◽  
Water Distribution Network ◽  
Simulation Models ◽  
Pressure Head ◽  
Minimum Requirement ◽  
Quality Of Water ◽  
Chlorine Decay

Background: The main issue in the operation of water distribution systems arises from the pressure deficiency resulting from events such as loss from leaks and bursts and loss of hydraulic capacity due to deterioration of aging water pipes. Such conditions affect the hydraulic performance of the system and the quality of water. Objective This paper investigates the hydraulic and water quality behavior of a selected water distribution network in Makkah city using the EPANET software. Methodology: The system was simulated under different hydraulic conditions including a loss of hydraulic capacity with pipe age and the presence of 30% leakage in the network over varying time conditions by employing extended period simulation models. Results and Conclusion: The results show that increasing pipe roughness with pipe age resulted in significantly low-pressure heads at the end of the network-particularly during peak demand hours. It also resulted in an increase in the rate of chlorine decay. Leakage in the network significantly affects the pressure head, resulting in pressure deficiency at some points in the network to below the minimum requirement during regular operation. The highest leakage rate occurs at periods of low demand where the pressure head in the network is high.

Modelling the chlorine decay process in a distribution network using a pilot system

2014 ◽  
Vol 9 (4) ◽  
pp. 534-550
Author(s):  
R. Buamah ◽  
K. Akodwaa-Boadi ◽  
M. Paintsil ◽  
E. K. Baah-Ennumh ◽  
A. A. Adjaottor
Keyword(s):  
Cast Iron ◽  
Distribution System ◽  
Water Distribution ◽  
Batch Reactor ◽  
Distribution Network ◽  
Bulk Water ◽  
Residual Chlorine ◽  
Pipe Material ◽  
Bulk Fluid ◽  
Chlorine Decay

Chlorine is one of the many disinfectants used to ensure bacteriological safety of drinking water. Usually residual chlorine is maintained within the distribution network to combat any probable re-contamination of the distributed water. This residual free chlorine, however, decays in water due to its reaction with the bulk water and the pipe material or deposits on the pipe walls. This study aimed at determining and modelling chlorine decay in the Kumasi water distribution network (KWDN) and determined locations where residual chlorine boosting is necessary. A double-jacketed batch reactor and a constructed pilot distribution system (PDS) were used to determine the bulk and wall decay coefficients. The PDS was run using aged PVC pipes (15–20 years), asbestos concrete pipes (40–50 years) and cast iron pipes (84 years) that have been in use in the KWDN. The SynerGEE® hydraulic model was used to identify the ‘zero chlorine’ points and predict top-up quantities. The bulk decay coefficient was found to be 0.053 h−1 within 8 hours at 26 °C and the residual chlorine decayed within the bulk fluid by 32–34% of its initial dose. Under the conditions tested, the cast iron pipes had the highest overall decay coefficients (K). Five locations within the network were identified as probable chlorine boosting points).

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