• Title, Summary, Keyword: Water distribution system

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Monitoring of Distribution System to Improve Tap Water Quality (수돗물 수질개선을 위한 배수관망시스템 관리 정책 - 수질모니터링을 중심으로 -)

  • Jun, Jesang;Kim, Jakyum
    • Journal of Korean Society of Water and Wastewater
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    • v.19 no.4
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    • pp.411-420
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    • 2005
  • Maintaining a good quality of drinking water produced through appropriate water treatment processes to the tap is as important as improving water quality in a water treatment plant (WTP). The quality of most tap water, however, does not have the same quality as that of the water produced in a WTP due to the contamination in the distribution system while they are delivered through pipes and water tanks. It is very important to maintain water quality in distribution system to water suppliers for consumer's health and safety. Furthermore, it is not possible to investigate the water quality of all points in the distribution system because the system has a wide area and very complex hydraulic characteristics. One economic solution to prevent water quality in distribution system from being deteriorated is monitoring several points that might have the least water quality in the distribution system. If the quality of water of the monitoring points selected by proper ways is better than the quality index of Drinking Water Quality Guidelines suggested by Korean Ministry of Environment, all other points in the distribution system would be safe to drink.

Effect of Reservoirs on Microbiological Water Qualities in a Drinking Water Distribution System

  • Lee Dong-Geun;Kim Sang-Jong;Park Seong-Joo
    • Journal of Microbiology and Biotechnology
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    • v.16 no.7
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    • pp.1060-1067
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    • 2006
  • This study was undertaken to determine the effect of reservoirs on water quality and the distribution of pathogenic and indicator bacteria in a drinking water distribution system (total length 14km). Raw water, disinfected water, and water samples from the distribution system were subjected to physicochemical and microbiological analyses. Most factors encountered at each season included residual chloride, nitrate, turbidity, and phosphorus for heterotrophic bacterial distribution, and hardness, heterotrophic bacteria, sampling site, and DOC (dissolved organic carbon) for bacteria on selective media. No Salmonella or Shigella spp. were detected, but many colonies of opportunistic pathogens were found. Comparing tap water samples taken at similar distances from the water treatment plant, samples that had passed through a reservoir had a higher concentration of heterotrophic bacteria, and a higher rate of colony formation with 10 times as many bacteria on selective media. Based on the results with m-Endo agar, the water in reservoirs appeared safe; however, coliforms and opportunistic pathogenic bacteria such as Pseudomonas aeruginosa were identified on other selective media. This study illustrates that storage reservoirs in the drinking water distribution system have low microbiological water quality by opportunistic pathogens, and therefore, water quality must be controlled.

Application of Rechlorination for Adequate Disinfection Ability in Water Distribution System (관로 내 적정소독능 확보를 위한 재염소 기법의 적용)

  • Lee, Doo-Jin;Kim, Young-Il;Lee, Jong-Min;Jung, Nam-Jung;Kim, Yong-Woon
    • Journal of Korean Society of Water and Wastewater
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    • v.20 no.5
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    • pp.701-707
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    • 2006
  • Disinfectant residual should be maintained to achieve biological stability during distribution of treated water. The wide distribution of retention times associated with storage and transport of water in a network and the reactivity of disinfectants make it difficult to maintain adequate residuals at critical locations. Rechlorination at some intermediate locations may reduce the total disinfectant dose while keeping residuals within specified limits throughout the water distribution system. In order to select the adequate location of rechlorination for achieving to maintain of residual chlorine throughout the distribution system, EPANET was used in this study. EPANET was well predicted chlorine transport and residual loss in the distribution system. Location of rechlorination was selected to maintain 0.4mg/L of residual chlorine throughout a water distribution system by field investigation and model simulation. The quantity of chlorine may reduced 36.7% and provided smooth residual between 0.42 and 0.60mg/L, when rechlorination would be used continuously at strategic location within the distribution system.

Application of the Determination Method of Monitoring Location in Real Water Distribution System (실제 상수관망에 대한 모니터링 지점선정방법의 적용)

  • Park, Yong-Gyun;Jung, Sung-Gyun;Kwon, Hyuk-Jae
    • Journal of Korean Society of Water and Wastewater
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    • v.29 no.6
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    • pp.617-623
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    • 2015
  • In this study, determination methods of monitoring location in water distribution system were suggested and applied to real test bed. Small block of Gwangtan water distribution system is consisted of 582 pipes, 564 junctions, 1 reservoir, and 1 pump station. Small block of Ho Chi Minh water distribution system is consisted of 162 pipes, 148 junctions, and 1 reservoir. Two small block water distribution systems were analyzed by pressure contribution analysis method to determine the optimum monitoring locations. The pressure change was estimated at each junctions by the additional demand at a junction. From the results, the optimum monitoring location can be determined by rank of pressure contribution index at each junctions due to demand change at a junction.

determination of Optimum Pipe diameter Using Multi-Stage Iterative Method in Water Distribution system (다단계 반복기법을 이용한 관로시스템의 최적관경 결정)

  • Han, Geon-Yeon;Park, Jae-Hong
    • Journal of Korea Water Resources Association
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    • v.31 no.3
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    • pp.327-335
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    • 1998
  • The distribution network is an essential part of all water supply systems. The cost of this portion of any sizable water supply system may amount to most of the entire cost of the project. This study tried to reduce the cost of the distribution system through optimization in system design. To determine pipe diameter considered in water distribution system design, a iterative procedure linked the flow analysis model and optimization model was used. Linear theory was introduced to analyze flowrate and revised-simplex method based on linear programming is used to optimize pipe diameter. This model was applied to wter distribution system with 22 and 35 pipes, and rapidly determine optimized commercial pipe diameters. Keywords : water distribution system, revised simplex method, optimum pipe diameters.

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Control of Biofilms in the Drinking Water Distribution System (배·급수관망에서 생물막 제어)

  • Mun, Sungmin;Yoon, Jeyong
    • Journal of Korean Society on Water Environment
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    • v.23 no.1
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    • pp.1-11
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    • 2007
  • The low nutrient environment in drinking water treatment plants and distribution systems cannot to be a good environment for bacterial growth. However, biofilms can be frequently found submerged surface in treatment plants and distribution system. Biofilms in distribution system are harmful, in that they can release organisms, and may cause problems in taste and odor of water. Control of these Biofilms is difficult, and disinfection alone is usually ineffective. Biofilms will not be eliminated from distribution systems by any contemporary technology available now or in the future. Therefore reduction of organic matter, improved disinfection, or a combination of these methods can be useful in controlling distribution system biofilms.

Reliability Analysis for Probability of Pipe Breakage in Water Distribution System (상수관망의 파이프 파괴확률 산정을 위한 신뢰성 해석)

  • Kwon, Hyuk Jae;Lee, Cheol Eung
    • Journal of Korean Society of Water and Wastewater
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    • v.22 no.6
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    • pp.609-617
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    • 2008
  • Water pipes are supposed to deliver the predetermined demand safely to a certain point in water distribution system. However, pipe burst or crack can be happened due to so many reasons such as the water hammer, natural pipe ageing, external impact force, soil condition, and various environments of pipe installation. In the present study, the reliability model which can calculate the probability of pipe breakage was developed regarding unsteady effect such as water hammer. For the reliability model, reliability function was formulated by Barlow formula. AFDA method was applied to calculate the probability of pipe breakage. It was found that the statistical distribution for internal pressure among the random variables of reliability function has a good agreement with the Gumbel distribution after unsteady analysis was performed. Using the present model, the probability of pipe breakage was quantitatively calculated according to random variables such as the pipe diameter, thickness, allowable stress, and internal pressure. Furthermore, it was found that unsteady effect significantly increases the probability of pipe breakage. If this reliability model is used for the design of water distribution system, safe and economical design can be accomplished. And it also can be effectively used for the management and maintenance of water distribution system.

Optimal Policy for a Regional Water Distribution System

  • Ryang, Yong-Joon
    • Journal of the military operations research society of Korea
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    • v.11 no.1
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    • pp.87-110
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    • 1985
  • This paper presents optimum policy of water supply distribution of the Osaka Prefecural Waterworks System located in the midwest of Japanese Islands. Owing to the ever increasing demand for water, the Osaka Prefectural Government endeavors to expand potable and industrial water distribution system to satisfy the growing water demand of the constituents under its jurisdiction. In this regard, the paper discusses a problem of establishing an efficient and effective water distribution system. The criteria to be considered are stability of water level at the reservoirs, stability of flow in the network, and the water treatment and distribution cost. These objective functions may be combined to form a multiple objective optimization problem or may be used independently and formulated into single objective optimization problems.

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Optimal design methodology of district metered area utilizing Geographic Information System (GIS를 이용한 상수관망 소블록 최적설계기법 개발)

  • Kim, Kyoung-Pil;Park, Yong-Gyun;Koo, Ja-Yong
    • Journal of Korean Society of Water and Wastewater
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    • v.29 no.2
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    • pp.223-231
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    • 2015
  • District Metered Area (DMA) construction is one of the most cost effective alternatives for management of water loss (i.e., water leakage) and energy consumption (i.e., water pressure) in water distribution systems. Therefore, it's being implemented to numerous new and existing water distribution systems worldwide. However, due to the complexity of water distribution systems, especially large-scale and highly looped systems, it is still very difficult to define the optimal boundary of DMAs considering all the aspects of water distribution system management requirements. In this study, a DMA design methodology (or a DMA design model) was developed with Geographic Information Systems (GIS) and hydraulic distribution system model to determine the optimal DMA boundary.

An Algorithm for Searching On-Off Valves to Isolate a Subsystem in a Water Distribution System (상수관망의 부분적 격리를 위한 제수밸브 탐색 알고리듬)

  • Jun, Hwan Don;Kim, Joong Hoon
    • Journal of Korean Society of Water and Wastewater
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    • v.20 no.1
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    • pp.35-43
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    • 2006
  • Concerns related to protecting, identifying, and isolating of subsystems of a water distribution network have led to the realization of the increased importance of valves in the system. The most important purpose of valves in water distribution systems is to isolate a subsystem due to breakage, maintenance activities, or contamination. A subsystem called segment is isolated by the closure of adjacent valves. Minimizing the pipe failure impact, an efficient algorithm is required to identify adjacent valves quickly. In this paper, an algorithm to identify adjacent valves to be closed to isolate a subsystem from the remainder of a network when a pipe failure is presented. The algorithm is operated on a matrix called the valve location matrix containing the information of valve locations. An application to an existing water distribution system demonstrates the developed algorithm efficiently locates the adjacent valves for the isolation of a broken pipe.