Numerical study on the impact of the coupling of diffuser parameters on the performance of submersible pumps used in town water distribution systems

2019 ◽  
Vol 41 (10) ◽  
Author(s):  
Qingshun Wei ◽  
Xihuan Sun ◽  
Asaad Y. Shamseldin
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Numerical Study ◽  
Water Distribution Systems ◽  
The Impact

scholarly journals Modeling Bacterial Regrowth and Trihalomethane Formation in Water Distribution Systems

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 463
Author(s):  
Gopinathan R. Abhijith ◽  
Leonid Kadinski ◽  
Avi Ostfeld
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Mechanistic Model ◽  
Water Distribution Systems ◽  
Sensitivity Study ◽  
Operating Conditions ◽  
Growth Rate Constant ◽  
Model Parameters ◽  
Bacterial Regrowth ◽  
The Impact

The formation of bacterial regrowth and disinfection by-products is ubiquitous in chlorinated water distribution systems (WDSs) operated with organic loads. A generic, easy-to-use mechanistic model describing the fundamental processes governing the interrelationship between chlorine, total organic carbon (TOC), and bacteria to analyze the spatiotemporal water quality variations in WDSs was developed using EPANET-MSX. The representation of multispecies reactions was simplified to minimize the interdependent model parameters. The physicochemical/biological processes that cannot be experimentally determined were neglected. The effects of source water characteristics and water residence time on controlling bacterial regrowth and Trihalomethane (THM) formation in two well-tested systems under chlorinated and non-chlorinated conditions were analyzed by applying the model. The results established that a 100% increase in the free chlorine concentration and a 50% reduction in the TOC at the source effectuated a 5.87 log scale decrement in the bacteriological activity at the expense of a 60% increase in THM formation. The sensitivity study showed the impact of the operating conditions and the network characteristics in determining parameter sensitivities to model outputs. The maximum specific growth rate constant for bulk phase bacteria was found to be the most sensitive parameter to the predicted bacterial regrowth.

Stochastic approach for performance evaluation regarding water distribution systems

2007 ◽  
Vol 56 (9) ◽  
pp. 29-36 ◽  
Author(s):  
M. Möderl ◽  
T. Fetz ◽  
W. Rauch
Keyword(s):  
Performance Evaluation ◽  
Case Studies ◽  
Distribution Systems ◽  
Water Distribution ◽  
Performance Indicator ◽  
Water Distribution Systems ◽  
Stochastic Approach ◽  
Cumulative Distribution ◽  
Design System ◽  
The Impact

A traditional procedure for performance evaluation of systems is to test approaches on one or more case studies. However, it is well known that the investigation of real case studies is a tedious task. Moreover, due to the limited amount of case studies available it is not certain that all aspects of a problem can be covered in such procedure. With increasing computer power an alternative methodology has emerged, that is the investigation of a multitude of virtual case studies by means of a stochastic consideration of the overall performance. Within the frame of this approach we develop here a modular design system (MDS) for water distribution systems (WDSs). With the algorithmic application of such a MDS it is possible to create a variety of different WDSs. As an example of stochastic performance evaluation the impact of pipe breakages on WDSs is estimated applying a pressure driven performance indicator. This performance indicator is evaluated stochastically. Likewise the performance evaluation of a variety of WDSs is also performed stochastically. Cumulative distribution function, histogram and other statistical properties of 2,280×1,000 performance results of the different WDSs are calculated to highlight the applicability of the introduced stochastic approach.

Regulation response of pilot operated diaphragm pressure reducing valves: laboratory testing and impact on the performance of pressure control modes in water distribution systems

2021 ◽  
Author(s):  
Mouna Doghri ◽  
Sophie Duchesne ◽  
Annie Poulin ◽  
J.-P. Villeneuve
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Pressure Control ◽  
Quebec City ◽  
Real Time Control ◽  
Hydraulic Simulation ◽  
Pressure Setting ◽  
Time Control ◽  
The Impact

Pressure control is recognized as an efficient measure to reduce leaks from water distribution systems. The effectiveness of various pressure control modes, by means of pilot operated diaphragm pressure reducing valves (PRVs), is evaluated in this paper taking into account the sensitivity of the valve to various settings. First, the response of a PRV to consecutive pressure settings variations was experimentally evaluated in the hydraulic simulation laboratory of National Institute for Scientific Research (INRS). These experiments revealed that the studied valve reacts only when the pressure setting variation corresponds to at least 1/6 turn of the pilot valve. Second, a real case study from Quebec City, Canada, was simulated in order to evaluate the impact of the PRV response on three pressure control modes: fixed control, time based control, and real time control (RTC). The results show that RTC of pressure leads to leakage rate reduction on the studied network but that the PRV operational constraints limit the expected performance of RTC.

scholarly journals Risk-based sensor placement methods for burst/leak detection in water distribution systems

2017 ◽  
Vol 17 (6) ◽  
pp. 1663-1672 ◽  
Author(s):  
E. Forconi ◽  
Z. Kapelan ◽  
M. Ferrante ◽  
H. Mahmoud ◽  
C. Capponi
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Social Economic ◽  
Water Distribution Systems ◽  
Water System ◽  
Water Distribution Network ◽  
Leak Detection ◽  
Optimal Placement ◽  
Water Volume ◽  
The Impact

Abstract The optimal placement of sensors for burst/leak detection in water distribution systems is usually formulated as an optimisation problem. In this study three different risk-based functions are used to drive optimal location of a given number of sensors in a water distribution network. A simple function based on likelihood of leak non-detection is compared with two other risk-based functions, where impact and exposure are combined with the leak detection likelihood. The impact is considered proportional to the demand water volume while the exposure is related to the importance of the connections and it is evaluated in social, economic or safety terms. The methods are applied to a district metered area of the Harrogate network by means of a modified EPANET model, to take into account the pressure-driven functioning conditions of the system. The results show that the exposure can lead to a different sensor location ranking with respect to other criteria used and hence the proposed methodology can represent a useful tool for water system managers to distribute the sensors in the network, complying with hydraulic, social and economical requirements.

Evaluation of treatment methods to reduce the corrosivity of soft waters

2006 ◽  
Vol 6 (5) ◽  
pp. 101-110 ◽  
Author(s):  
Y. Jaeger ◽  
S. Oberti ◽  
L. Guichot ◽  
J. Baron
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Iron Corrosion ◽  
Treatment Methods ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
The Impact

Soft waters characterised with low alkalinity tend to reduce the lifetime of pipes in drinking water distribution systems. Consequently, the corrosion induced is likely to deteriorate water quality at the consumer's tap. Two different types of treatment methods are commonly used to control the corrosion effects of soft waters: (i) the addition of phosphate corrosion inhibitors, and (ii) the remineralisation process. In order to facilitate the decision making of network operator to use suitable treatment methods, a comparative pilot-scale experiment was performed. The above two treatment strategies were tested using pipes representing both drinking water distribution systems (used materials: cast iron and steel) and household plumbing systems (used material: copper). The impact of the two techniques was assessed by means of water quality monitoring (pH, metal leaching, etc) and of corrosion measurements using electrochemical probes as well as weight-loss coupons. The results obtained after a 15 month long experiment showed that remineralisation method was clearly the most effective way to control soft water corrosion. The implementation of this method resulted in a 50% reduction in metals leaching and about 40% decrease in iron corrosion rates.

scholarly journals Cr(VI) and Cr(III) Release From Different Layers of Cast Iron Corrosion Scales in Drinking Water Distribution Systems: The Impact of pH, Temperature, Sulfate, and Chloride

2021 ◽  
Author(s):  
Yimei Tian ◽  
Tiantian Yu ◽  
Jingyi Shen ◽  
Guolei Zheng ◽  
Han Li ◽  
...  
Keyword(s):  
Drinking Water ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Extraction Procedure ◽  
Surrounding Water ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
Corrosion Scales ◽  
The Impact

Abstract Chromium accumulated from source water and pipeline lining materials in corrosion scales could potentially be released into bulk water in drinking water distribution systems (DWDS). Chromium behaviors between corrosion scale phase and the surrounding water phase vary spatially in different layers and temporally in different DWDS running periods. In this study, corrosion scales sampled from actual DWDS were first characterized by SEM, XRD, XRF, and the modified BCR three-step sequential extraction procedure. Then scales were divided into the outer and inner layers for subsequent analysis. Static accumulation and release experiments were performed with Cr(VI) and Cr(III) on two distinct scale layers to systematically assess the influence of pH, temperature, sulfate, and chloride. The release behaviors of Cr(VI) under the co-effect of multiple factors were investigated in orthogonal experiments. Results showed that in the outer and inner layers of corrosion scales, chromium exhibited differences in accumulation and release behaviors, with the outer layer accumulating less and releasing more. The mechanisms of chromium retention based on different iron (oxyhydr)oxides were discussed.

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