scholarly journals Analysis of water quality characteristic for water distribution systems

2018 ◽  
Vol 9 (2) ◽  
pp. 152-162
Author(s):  
Yumin Wang ◽  
Guangcan Zhu ◽  
Zhonglian Yang
Keyword(s):  
Water Quality ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Quality Characteristic ◽  
Residual Chlorine ◽  
Pipe Length ◽  
Water Quality Characteristic ◽  
Chlorine Decay ◽  
Single Pipe

Abstract Since governments all over the world are paying more attention to water quality in water distribution systems (WDS), a method based on mass balance and first-order chlorine decay model was proposed to assess the efficiency of WDS involving water quality (represented by residual chlorine). The concepts of surplus chlorine factor (S) for nodes in individual pipes and comprehensive surplus chlorine factor (CS) for nodes in WDS were put forward to represent the water quality characteristic of nodes in WDS based on the assumption that the structure of the pipe network and quantity of chlorine dose are definite. The proposed method was applied to two examples of WDS and sensitivity analysis regarding chlorine decay coefficient (k0) was discussed. The results indicated that values of CS for nodes in WDS are affected by the inflow of nodes, which is determined by water demand and pipe length from water sources to nodes. In addition, the value of CS increases with k0 when the inflow of the node is larger than the optimized inflow. The results verified that the deduction of S for a single pipe can be generalized to WDS, and can measure the water quality characteristics for nodes in WDS easily.

scholarly journals Spatial diversity of chlorine residual in a drinking water distribution system: application of an integrated fuzzy logic technique

2014 ◽  
Vol 17 (2) ◽  
pp. 293-306 ◽  
Author(s):  
Donatella Termini ◽  
Gaspare Viviani
Keyword(s):  
Water Quality ◽  
Fuzzy Logic ◽  
Drinking Water ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Residual Chlorine ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
Fuzzy Logic Technique

A reduction in the concentration of chlorine, which is used as a chemical disinfectant for water in drinking water distribution systems, can be considered to be an index of the progressive deterioration of water quality. In this work, attention is given to the spatial distribution of the residual chlorine in drinking water distribution systems. The criterion for grouping the water-quality parameters normally used is highly subjective and often based on data that are not correctly identified. In this paper, a cluster analysis based on fuzzy logic is applied. The advantage of the proposed procedure is that it allows a user to identify (in an automatic way and without any specific assumption) the zonation of the network and easily calibrate the unknown parameters. An analysis of the correlation between the sampling sites for the residual chlorine has been used to assess the applicability of the procedure.

Water Quality Reliability Analysis of Water Distribution Systems Based on Monte-Carlo Simulation

2013 ◽  
Vol 777 ◽  
pp. 401-406 ◽  
Author(s):  
Xia Li ◽  
Ying Sun ◽  
Xiao Han ◽  
Xin Hua Zhao
Keyword(s):  
Water Quality ◽  
Monte Carlo ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Treatment Plant ◽  
High Tech ◽  
Residual Chlorine ◽  
Dynamic Link Library ◽  
High Level

Water distribution systems (WDS) are important urban infrastructures which are designed for safely conveying potable water from treatment plant to users tap with adequate quantity and desired quality. The water quality reliability evaluation of WDS has positive and critical meanings for ensuring water supply security, reliability and maintaining a high level of service. In this paper, firstly the evaluation index of water quality reliability of municipal water distribution systems has been set up which is characterized by the residual chlorine availability. Then, taking into account the random nature of component failures, the variation of water demand through the 24 hours of a day and the chlorine variation of the treated water in water plant through the 24 hours of a day, the Monte Carlo-based reliability model are established based on the dynamic link library toolkit provided by EPANET 2.0 for the hydraulic and water quality calculation engine. Finally, the water quality reliability of each node and system is evaluated taking water network of some region in Tianjin Binhai High-tech Area (BHA) as example. The research results can be applied to the whole process from planning and design to operation of WDS, and the theoretical basis and decision support for optimal design and operation of WDS are provided for designers and decision-makers.

scholarly journals Whole metagenome sequencing of chlorinated drinking water distribution systems

2018 ◽  
Vol 4 (12) ◽  
pp. 2080-2091 ◽  
Author(s):  
Isabel Douterelo ◽  
Carolina Calero-Preciado ◽  
Victor Soria-Carrasco ◽  
Joby B. Boxall
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Quality And Safety ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
Chlorinated Drinking Water ◽  
Metagenome Sequencing

This research highlights the potential of whole metagenome sequencing to help protect drinking water quality and safety.

Experimental study of solute mixing at double-Tee junctions in water distribution systems

2014 ◽  
Vol 15 (3) ◽  
pp. 474-482 ◽  
Author(s):  
Tingchao Yu ◽  
Liang Tao ◽  
Yu Shao ◽  
Tuqiao Zhang
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Mixing State ◽  
Pipe Length ◽  
Incomplete Mixing ◽  
Mixing Behavior ◽  
Tee Junction ◽  
The Cross ◽  
Special Case

Recent studies have focused on mixing behavior at cross junctions, and incomplete mixing at cross junctions in water distribution systems was verified. Nevertheless, the research results on mixing at other junction configurations, such as double-Tee junctions, were insufficient. Double-Tee junctions can potentially be misrepresented as cross junctions because of network skeletonization. Hence, the diffusion and dilution of the contaminants at junctions were largely underestimated. To examine the mixing phenomenon and collect accurate mixing data at the double-Tee junction, a series of laboratory experiments was carried out with various Reynolds number ratios at the inlets and outlets combined with different dimensionless connecting pipe lengths (L/D). Results showed that the dimensionless connecting pipe length served an important function in mixing at double-Tee junctions. The cross junction was the special case of the double-Tee joint when L/D=0. The complete mixing state occurred when L/D→∞. The mixing degree of the double-Tee junction was between the cross junction and the complete mixing state. A conceptual model that described the mixing behavior at double-Tee junctions was developed. The model included the use of the dimensionless parameter φ, which defined the degree of departure from complete mixing.

Influence factors of organic compounds leaching from PE pipes and the potential toxic effects on E. coli and rat C6 glioma cell

2015 ◽  
Vol 16 (2) ◽  
pp. 402-409 ◽  
Author(s):  
Jingqing Liu ◽  
Hongxi Peng ◽  
Shengwei Tan ◽  
Jianmin Wu ◽  
Hamid Bastani ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Glioma Cell ◽  
Distribution Systems ◽  
Water Distribution ◽  
Influence Factors ◽  
C6 Glioma ◽  
Residual Chlorine ◽  
C6 Glioma Cell ◽  
Rat C6 Glioma

Water quality safety is always a hot topic. Recently there has been a great increase in the use of polyethylene (PE) pipes in drinking water distribution systems in China. Some organics can leach from PE pipes into drinking water, which is undoubtedly harmful for consumers. In this study, potential organics leaching from two Chinese brands of PE pipe were investigated in order to determine the potential risk to both consumers and water quality. Their released amounts are characterized by UV254 instead of total organic carbon (TOC). Organics are identified by means of gas chromatography coupled with mass spectrometry (GC-MS). Influencing factors such as types of water, time, pH, residual chlorine are discussed. The cytotoxicity of leaching organics is first put forward in this study, and rat C6 glioma cell is used to assess the effect of leaching organics; the increasing dosage of soaking solution negatively affects morphology and relative viability of rat C6 glioma cell. The results show that residual chlorine, time and temperature have a positive effect on organics release, while pH plays an opposite role.

Prediction of chlorine and trihalomethanes concentration profile in bulk drinking water distribution systems from laboratory data

2003 ◽  
Vol 3 (1-2) ◽  
pp. 239-246 ◽  
Author(s):  
G. Kastl ◽  
I. Fisher ◽  
V. Jegatheesan ◽  
J. Chandy ◽  
K. Clarkson
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Laboratory Data ◽  
Water Distribution Systems ◽  
Optimum Level ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
Chlorine Decay

Nearly all drinking water distribution systems experience a “natural” reduction of disinfection residuals. The most frequently used disinfectant is chlorine, which can decay due to reactions with organic and inorganic compounds in the water and by liquid/solids reaction with the biofilm, pipe walls and sediments. Usually levels of 0.2-0.5 mg/L of free chlorine are required at the point of consumption to maintain bacteriological safety. Higher concentrations are not desirable as they present the problems of taste and odour and increase formation of disinfection by-products. It is usually a considerable concern for the operators of drinking water distribution systems to manage chlorine residuals at the “optimum level”, considering all these issues. This paper describes how the chlorine profile in a drinking water distribution system can be modelled and optimised on the basis of readily and inexpensively available laboratory data. Methods are presented for deriving the laboratory data, fitting a chlorine decay model of bulk water to the data and applying the model, in conjunction with a simplified hydraulic model, to obtain the chlorine profile in a distribution system at steady flow conditions. Two case studies are used to demonstrate the utility of the technique. Melbourne’s Greenvale-Sydenham distribution system is unfiltered and uses chlorination as its only treatment. The chlorine model developed from laboratory data was applied to the whole system and the chlorine profile was shown to be accurately simulated. Biofilm was not found to critically affect chlorine decay. In the other case study, Sydney Water’s Nepean system was modelled from limited hydraulic data. Chlorine decay and trihalomethane (THM) formation in raw and treated water were measured in a laboratory, and a chlorine decay and THM model was derived on the basis of these data. Simulated chlorine and THM profiles agree well with the measured values available. Various applications of this modelling approach are also briefly discussed.

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