Keeping residual chlorine and decreasing unpleasant odor caused by disinfection of tap water

2006 ◽  
Vol 6 (2) ◽  
pp. 193-199 ◽  
Author(s):  
H. Kitazawa
Keyword(s):  
Water Supply ◽  
Distribution System ◽  
Water Distribution ◽  
Tap Water ◽  
Internal Surface ◽  
Water Distribution Network ◽  
Residual Chlorine ◽  
Disinfection Process ◽  
Unpleasant Odor ◽  
Sanitary Conditions

Keeping residual chlorine at a certain level in tap water is effective not only in improving sanitary conditions but also in suppressing the regrowth of microorganisms and preventing the formation of biofilms on the internal surface of distribution pipelines. However, in our recent survey about customer satisfaction, over 50% of the customers were not satisfied with tap water for drinking. One of the main reasons for the dissatisfaction was the odor or taste caused by the disinfection process. We therefore investigated the behavior of residual chlorine in the water distribution network by estimating the chlorine decay coefficients, and discussed measures to decrease the unpleasant odor while maintaining the effect of disinfection. The effective measures are shortening of retention time, replacement of aged pipes, corrosion control of distribution and service pipes, removal of organic substances in water, additional chlorination at water-supply stations, and improvement in water supply facilities with receiving tanks. By adopting these measures, and setting the target value of residual chlorine at representative water taps, we successfully controlled residual chlorine at the outlets of purification plants or water-supply stations by application of the decay coefficient of chlorine in each water distribution system.

scholarly journals Rehabilitation Planning of Water Distribution neTwork through a Reliability – Based Risk Assessment

2017 ◽  
Author(s):  
Marianna D'Ercole ◽  
Maurizio Righetti ◽  
Gema Raspati ◽  
Paolo Bertola ◽  
Rita Maria Ugarelli
Keyword(s):  
Water Supply ◽  
Distribution System ◽  
Water Distribution ◽  
Climate Change Impacts ◽  
Water Distribution Network ◽  
Supply System ◽  
Water Supply System ◽  
Analysis Model ◽  
Output Analysis ◽  
Support Tool

The management of existing water distribution system (WDS) is challenged by ageing of infrastructure, population growth, increasing of urbanization, climate change impacts and environmental pollution. Therefore, there is a need for integrated solutions that support decision makers to plan today, while taking into account the effect of these factors in the mid and long term. The paper is part of a more comprehensive project, where advanced hydraulic analysis for WDS is coupled with a dynamic resources input-output analysis model. The proposed modeling solution can be used to optimize the performance of a water supply system while considering also the energy consumption and consequently the environmental impacts. Therefore, as a support tool in the management of a water supply system also in the intervention planning. Here a possible application is presented for rehabilitation/replacement planning while maximizing the network mechanical reliability and minimizing risk of unsupplied demand and pressure deficit, under given economic constraints.

Investigating disinfectant by-products in Harare potable water supply, Zimbabwe

2018 ◽  
Vol 8 (3) ◽  
pp. 415-428 ◽  
Author(s):  
Kuitakwashe Nhongo ◽  
Zvikomborero Hoko ◽  
Jameson Kugara
Keyword(s):  
Water Supply ◽  
Environmental Protection Agency ◽  
Distribution System ◽  
Water Distribution ◽  
The United States ◽  
World Health ◽  
Residual Chlorine ◽  
By Products ◽  
Trihalomethanes Formation

Abstract Formation of disinfectant by-products was investigated in the Harare water supply system from February to April 2015. Sampling sites were selected from the lake, Morton Jaffray Water Treatment Works and critical points in the distribution system. The spatial variations of trihalomethanes and selected water quality parameters were investigated for 15 sampling points in 5 sampling campaigns to assess suitability for drinking. All trihalomethane species were measured, namely chloroform, bromodichloromethane, dibromochloromethane and bromoform. Only chloroform and bromodichloromethane were detected. The study confirmed that there is trihalomethanes formation in the Harare water distribution system and that it is affected by the residence time and presence of organic matter in the system. However, the levels of trihalomethanes are generally within the levels suggested by the World Health Organization. Only bromodichloromethane presents a risk for long-term exposure as it had levels that exceeded the limit for long-term exposure suggested by the United States Environmental Protection Agency. Bromodichloromethane, turbidity and free residual chlorine levels were not suitable for drinking in some of the zones. Boosting of chlorine residuals is necessary especially in areas with free chlorine less than 0.2 mg/L. Injection of ammonia, periodic cleaning of storage reservoirs, and flushing of lines will reduce trihalomethanes formation.

scholarly journals Promoting equitable water distribution system from Melamchi Water Supply Project in Kathmandu Valley

2020 ◽  
Vol 20 (8) ◽  
pp. 2964-2970
Author(s):  
D. P. Ayadi ◽  
A. Rai ◽  
A. Pandey
Keyword(s):  
Water Supply ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Network ◽  
Supply System ◽  
Kathmandu Valley ◽  
Drinking Water Resources ◽  
Key Issues

Abstract The effective and efficient supply of drinking water resources are key to its long-term use and access. In recent decades, the population of Kathmandu Valley has exploded owing to several factors. The water supply system here has also undergone remarkable changes and efforts have been made to enhance its equitable distribution. The major effort, of course, is the Melamchi Water Supply Project (MWSP). As the project approaches completion of its first phase, we would like to point out several key issues for the water distribution system here and express our opinions on promoting equitable water distribution. For this we conducted a thorough literature review and found that improvement in the water distribution network and water tariff in the valley, along with promotion of alternative mitigation options, are the focal issues for promoting an equitable water distribution system in Kathmandu Valley.

scholarly journals Design and Analysis of Rural Water Supply System Using Loop 4.0 and Water Gems V8i for Nava Shihora Zone 1

2019 ◽  
Vol 9 (1) ◽  
pp. 2258-2266
Keyword(s):  
Water Supply ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Extended Period ◽  
Supply System ◽  
Water Supply System ◽  
Residual Chlorine ◽  
Residual Pressure ◽  
Rural Water

The study presents the hydraulic design and analysis of Rural Water Distribution System (WDS) for Nava shihora region of zone 1 of the state of Gujarat, India. Water supply distribution system is designed for this study for population estimated for future 30 years. LOOP 4.0 and Water Gems v8i software have been used and the results are compared to determine the economical size of pipes for water distribution system. The economical size of pipes of water supply distribution system is designed by considering the constraints; residual pressure at each node, velocity of flow in pipe, head loos in pipes, material of pipes, elevated service reservoir level, peak factor and available commercial pipe diameters. Further water distribution system has been analyzed for extended period simulation (EPS) for the present population scenario for intermittent water supply using Water Gems v8i. Further water supply system is analyzed the residual chlorine concentration at nodes and in the pipe links and also the total cost of water supply system of rural region is estimated.

scholarly journals Rehabilitation Planning of Water Distribution Network through a Reliability – Based Risk Assessment

2018 ◽  
Author(s):  
Marianna D'Ercole ◽  
Maurizio Righetti ◽  
Gema Raspati ◽  
Paolo Bertola ◽  
Rita Maria Ugarelli
Keyword(s):  
Water Supply ◽  
Distribution System ◽  
Water Distribution ◽  
Climate Change Impacts ◽  
Water Distribution Network ◽  
Supply System ◽  
Water Supply System ◽  
Analysis Model ◽  
Output Analysis ◽  
Support Tool

The management of existing water distribution system (WDS) is challenged by ageing of infrastructure, population growth, increasing of urbanization, climate change impacts and environmental pollution. Therefore, there is a need for integrated solutions that support decision makers to plan today, while taking into account the effect of these factors in the mid and long term. The paper is part of a more comprehensive project, where advanced hydraulic analysis for WDS is coupled with a dynamic resources input-output analysis model. The proposed modeling solution can be used to optimize the performance of a water supply system while considering also the energy consumption and consequently the environmental impacts. Therefore, as a support tool in the management of a water supply system also in the intervention planning. Here a possible application is presented for rehabilitation/replacement planning while maximizing the network mechanical reliability and minimizing risk of unsupplied demand and pressure deficit, under given economic constraints.

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.

Determination of Neutral Point in Water Distribution Network Pipes with Variable Discharge on Route

2014 ◽  
Vol 909 ◽  
pp. 428-432 ◽  
Author(s):  
Ioan Sarbu ◽  
Gabriel Ostafe
Keyword(s):  
Water Supply ◽  
Distribution System ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Neutral Point ◽  
Water Supply Systems ◽  
Proposed Model

Distribution networks are an essential part of all water supply systems. Distribution system costs within any water supply scheme may be equal to or greater than 60% of the entire cost of the project. The reliability of supply is much greater in the case of looped networks. The pipe networks have concentrated outflows or uniform outflow along the length of each pipe. In some pipes with variable discharge of a looped distribution network, water velocity could be reversed between its extremities. Thus, it is a water stall point denominated neutral point in which the discharge is null. In this paper a mathematical model for the determination of water stall point location in the pipes with distributed consumption is developed. This model has been implemented in a computer program for PC microsystems. Numerical example will be presented to demonstrate the accuracy and efficiency of the proposed model.

scholarly journals Assessment Of Potable Water Supply Sources In Ilorin Metropolis, Kwara State, Nigeria

2013 ◽  
Vol 3 (1) ◽  
pp. 1-4 ◽  
Author(s):  
JJ Musa ◽  
GA Fumen
Keyword(s):  
Water Supply ◽  
Distribution System ◽  
Water Distribution ◽  
Tap Water ◽  
Life Quality ◽  
Vital Role ◽  
Research Approach ◽  
Residential Areas ◽  
Potable Water Supply ◽  
Approach Method

Water distribution system plays a vital role in preserving and providing a desirable life quality to the public. In this regards, the reliability of supply is a major component. This study was conducted using the investigative research approach method; 5000 questionnaires which were randomly distributed round the township of Ilorin and 4658 (93.16%) were returned. Among them, 2350 respondents said that they have their own wells dugged in their respective homes, 1100 respondents had their taps running at specific periods of the week, 750 individuals said that they have boreholes available, 308 people declared that they make use of the streams and rivers running around their areas while about 150 of the remaining buy water from the water vendors so they cannot tell the exact source of the water. It was discovered that majority of the residential areas in Ilorin do not depend on the tap water supply rather they depend on dugged wells and bore holes. Int. J. Agril. Res. Innov. & Tech. 3 (1): 1-4, June, 2013 DOI: http://dx.doi.org/10.3329/ijarit.v3i1.16042

Dezincification of Brass Water Meters in a Long-term Study: Effects of Anions, Alkalinity, and Residual Chlorine

2021 ◽  
Author(s):  
Shu-Ju Chao ◽  
Ming-Han Tsai ◽  
Rui-Pei Yu ◽  
Lap-Cuong Hua ◽  
Chi-Chang Hu ◽  
...  
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Tap Water ◽  
Residual Chlorine ◽  
Term Study ◽  
Water Characteristics ◽  
Long Term Study ◽  
Water Meters ◽  
Mixed Water

The dezincification of brass water meters in a water distribution system is affected by tap water characteristics. However, the effect of mixed water quality on corrosion and scaling formation on...

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