scholarly journals Estimation of NRW using Main Parameters of Water Distribution Systems

10.29007/1gpk ◽  
2018 ◽  
Author(s):  
Dongwoo Jang ◽  
Gyewoon Choi ◽  
Jintak Choi ◽  
Hyoseon Park
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Model Simulation ◽  
Tap Water ◽  
Water Distribution Systems ◽  
Ann Model ◽  
Effective Parameters ◽  
Operational Parameters ◽  
Water Losses ◽  
The Relationship

The non-revenue water (NRW) is the water losses from unbilled authorized consumption, obvious losses and actual losses among the total amount of water supply (tap water supplied from water purification plants) in the water distribution systems. Various studies analyze data using statistical methods and identify the relationship as a method to estimate the NRW. For estimating the NRW of the water distribution systems, selected main parameters were used to this study. The main parameters were used to ANN model simulation, and compared to observed NRW data to determine the accuracy of NRW estimation. In the results, the method using artificial neural network was found to be more accurate in estimating the NRW than multiple regression analysis. In this study, the effective parameters of the NRW were determined, especially physical and operational parameters have high relationship to the NRW estimation.

Kinetic aspects of biofilm formation on surfaces exposed to drinking water

1995 ◽  
Vol 32 (8) ◽  
pp. 61-65 ◽  
Author(s):  
D. van der Kooij ◽  
H. S. Vrouwenvelder ◽  
H. R. Veenendaal
Keyword(s):  
Drinking Water ◽  
Biofilm Formation ◽  
Distribution Systems ◽  
Water Distribution ◽  
Formation Rate ◽  
Water Distribution Systems ◽  
Acetate Concentration ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
The Relationship

Biofilm formation in drinking water distribution systems should be limited to prevent the multiplication of undesirable bacteria and other organisms. Certain types of drinking water with an AOC concentration below 10 μg of acetate-C eq/l can support the growth of Aeromonas. Therefore, the effect of acetate at a concentration of 10 μg of C/l on the biofilm formation rate (BFR) of drinking water with a low AOC concentration (3.2 μg C/l) was determined. Drinking water without acetate had a BFR of 3.9 pg ATP/cm2.day, whereas a BFR value of 362 pg ATP/cm2.day was found with acetate added. These data indicate that a low acetate concentration strongly affects biofilm formation, and that only a small fraction of AOC is available for biofilm formation. Aeromonads did not multiply in the biofilm despite their ability to grow at a concentration of 10 μg of acetate-C/l. Further investigations are needed to elucidate the relationship between substrate concentration and biofilm formation in drinking water distribution systems and the growth of undesirable bacteria in these biofilms.

Occurrence of disinfection by-products in tap water distribution systems and their associated health risk

2013 ◽  
Vol 185 (9) ◽  
pp. 7675-7691 ◽  
Author(s):  
Jin Lee ◽  
Eun-Sook Kim ◽  
Bang-Sik Roh ◽  
Seog-Won Eom ◽  
Kyung-Duk Zoh
Keyword(s):  
Health Risk ◽  
Distribution Systems ◽  
Water Distribution ◽  
Tap Water ◽  
Water Distribution Systems ◽  
By Products

A model to simulate leakage through joints in water distribution systems

2015 ◽  
Vol 15 (4) ◽  
pp. 852-863 ◽  
Author(s):  
Carmine Covelli ◽  
Luca Cozzolino ◽  
Luigi Cimorelli ◽  
Renata Della Morte ◽  
Domenico Pianese
Keyword(s):  
Atmospheric Pressure ◽  
Distribution Systems ◽  
Water Distribution ◽  
Pressure Effect ◽  
Water Distribution Systems ◽  
Outer Side ◽  
Preliminary Evaluation ◽  
Considerable Part ◽  
Water Losses ◽  
Background Leakage

The water loss is a phenomenon frequently observed within water distribution systems. A considerable part of water losses occurs either because of the incorrect assembly of joints or because of the fatigue and ageing of the material used to ensure a watertight seal. Moreover, such a leakage is very difficult to detect and to assess. In this work, we present a novel formulation for modelling the pressure effect on the background leakage through the joints. The proposed approach is based on the preliminary evaluation of the enlargement Δω, due to pressure, of the existing space between the outer side of the spigot end of a pipe and the inner wall of the hub end of the adjacent pipe (which is characterised by the area ωatm at atmospheric pressure). Furthermore, the whole procedure is based on the evaluation, by field data or calibration, of a parameter ξ representing the rate of enlarged area ω that, for several reasons, may be not covered by the gasket, ω being the value, at pressure p, of the area above defined.

scholarly journals Analysis of water losses in two selected water distribution systems

2017 ◽  
Vol 17 ◽  
pp. 00062 ◽  
Author(s):  
Anna Musz-Pomorska ◽  
Małgorzata Iwanek ◽  
Katarzyna Parafian ◽  
Katarzyna Wójcik
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Water Losses

scholarly journals Virus contamination from operation and maintenance events in small drinking water distribution systems

2011 ◽  
Vol 9 (4) ◽  
pp. 799-812 ◽  
Author(s):  
Elisabetta Lambertini ◽  
Susan K. Spencer ◽  
Burney A. Kieke ◽  
Frank J. Loge ◽  
Mark A. Borchardt
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Tap Water ◽  
Water Distribution Systems ◽  
Ultraviolet Disinfection ◽  
Drinking Water Distribution Systems ◽  
Virus Contamination ◽  
Drinking Water Distribution

We tested the association of common events in drinking water distribution systems with contamination of household tap water with human enteric viruses. Viruses were enumerated by qPCR in the tap water of 14 municipal systems that use non-disinfected groundwater. Ultraviolet disinfection was installed at all active wellheads to reduce virus contributions from groundwater to the distribution systems. As no residual disinfectant was added to the water, any increase in virus levels measured downstream at household taps would be indicative of distribution system intrusions. Utility operators reported events through written questionnaires. Virus outcome measures were related to distribution system events using binomial and gamma regression. Virus concentrations were elevated in the wells, reduced or eliminated by ultraviolet disinfection, and elevated again in distribution systems, showing that viruses were, indeed, directly entering the systems. Pipe installation was significantly associated with higher virus levels, whereas hydrant flushing was significantly associated with lower virus levels. Weak positive associations were observed for water tower maintenance, valve exercising, and cutting open a water main. Coliform bacteria detections from routine monitoring were not associated with viruses. Understanding when distribution systems are most vulnerable to virus contamination, and taking precautionary measures, will ensure delivery of safe drinking water.

scholarly journals Prevalence of Antibiotic Resistance in Drinking Water Treatment and Distribution Systems

2009 ◽  
Vol 75 (17) ◽  
pp. 5714-5718 ◽  
Author(s):  
Chuanwu Xi ◽  
Yongli Zhang ◽  
Carl F. Marrs ◽  
Wen Ye ◽  
Carl Simon ◽  
...  
Keyword(s):  
Drinking Water ◽  
Antibiotic Resistance ◽  
Water Treatment ◽  
Distribution Systems ◽  
Water Distribution ◽  
Tap Water ◽  
Water Distribution Systems ◽  
Drinking Water Treatment ◽  
Molecular Techniques ◽  
Source Water

ABSTRACT The occurrence and spread of antibiotic-resistant bacteria (ARB) are pressing public health problems worldwide, and aquatic ecosystems are a recognized reservoir for ARB. We used culture-dependent methods and quantitative molecular techniques to detect and quantify ARB and antibiotic resistance genes (ARGs) in source waters, drinking water treatment plants, and tap water from several cities in Michigan and Ohio. We found ARGs and heterotrophic ARB in all finished water and tap water tested, although the amounts were small. The quantities of most ARGs were greater in tap water than in finished water and source water. In general, the levels of bacteria were higher in source water than in tap water, and the levels of ARB were higher in tap water than in finished water, indicating that there was regrowth of bacteria in drinking water distribution systems. Elevated resistance to some antibiotics was observed during water treatment and in tap water. Water treatment might increase the antibiotic resistance of surviving bacteria, and water distribution systems may serve as an important reservoir for the spread of antibiotic resistance to opportunistic pathogens.

scholarly journals A Clonal Lineage of Fusarium oxysporum Circulates in the Tap Water of Different French Hospitals

2016 ◽  
Vol 82 (21) ◽  
pp. 6483-6489 ◽  
Author(s):  
Véronique Edel-Hermann ◽  
Marc Sautour ◽  
Nadine Gautheron ◽  
Julie Laurent ◽  
Serge Aho ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Distribution Systems ◽  
Water Distribution ◽  
Tap Water ◽  
Water Distribution Systems ◽  
Intergenic Spacer ◽  
Human Infection ◽  
Clonal Lineage ◽  
Water Networks ◽  
Content Type

ABSTRACTFusarium oxysporumis typically a soilborne fungus but can also be found in aquatic environments. In hospitals, water distribution systems may be reservoirs for the fungi responsible for nosocomial infections.F. oxysporumwas previously detected in the water distribution systems of five French hospitals. Sixty-eight isolates from water representative of all hospital units that were previously sampled and characterized by translation elongation factor 1α sequence typing were subjected to microsatellite analysis and full-length ribosomal intergenic spacer (IGS) sequence typing. All but three isolates shared common microsatellite loci and a common two-locus sequence type (ST). This ST has an international geographical distribution in both the water networks of hospitals and among clinical isolates. The ST dominant in water was not detected among 300 isolates ofF. oxysporumthat originated from surrounding soils. Further characterization of 15 isolates by vegetative compatibility testing allowed us to conclude that a clonal lineage ofF. oxysporumcirculates in the tap water of the different hospitals.IMPORTANCEWe demonstrated that a clonal lineage ofFusarium oxysporuminhabits the water distribution systems of several French hospitals. This clonal lineage, which appears to be particularly adapted to water networks, represents a potential risk for human infection and raises questions about its worldwide distribution.

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