scholarly journals Hydraulic Model Calibration and Performance Assessment of Pressure Managed Areas with Multiple Inlets

2020 ◽  
Author(s):  
Attila Bibok ◽  
Roland Fülöp
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Model Calibration ◽  
Water Distribution ◽  
Real Life ◽  
Distribution Networks ◽  
General Purpose ◽  
Pressure Management ◽  
Pressure Setting ◽  
Drinking Water Distribution

Pressure management is a widely adopted technique in the toolset of drinking water distribution system operators. It has multiple benefits, like reducing physical losses in pipe networks with excessive leakage, prolong the expected lifetime of the pipes and protecting home appliances from unacceptably high pressure. In some cases, even legislation compliance can be the motivation behind pressure management: It is mandatory to supply water at the customer’s connection between 1.5 and 6.0 bar in Hungary since 2011. Diaphragm pressure reducing valves are widespread in the drinking water distribution networks. Although, their sensitivity for gas pocket accumulation in the valve house makes hydraulic calibration of these pressure managed areas a challenging task for hydraulic modelers and network operators. This is especially true when more than one inlet is used to supply the same area in order to increase resilience and flow capacity.This paper investigates the hydraulic properties of pressure reduced areas with multiple inlet points. Model calibration using a single valve and minor loss was found insufficient because the additional pressure loss referenced to the pressure setting has a non-quadratic relationship with flow-rate on the discharge side under real-life circumstances. This phenomenon can be handled by using a PRV (pressure reducing valve) + GPV (general purpose valve) in series.

scholarly journals Monitoring biofilm formation and activity in drinking water distribution networks under oligotrophic conditions

2003 ◽  
Vol 47 (5) ◽  
pp. 91-97 ◽  
Author(s):  
R. Boe-Hansen ◽  
A.C. Martiny ◽  
E. Arvin ◽  
H.-J. Albrechtsen
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Water Distribution ◽  
Removal Rate ◽  
Distribution Networks ◽  
Activity Measurement ◽  
Leucine Incorporation ◽  
Drinking Water Distribution ◽  
In Series ◽  
Biomass Quantification

In this study, the construction a model distribution system suitable for studies of attached and suspended microbial activity in drinking water under controlled circumstances is outlined. The model system consisted of two loops connected in series with a total of 140 biofilm sampling points. The biofilm from the system was studied using 11 different microbial methods and the results were compared and discussed. The methods were used for biomass quantification (AODC, HPC and ATP determination), visualisation of structure (CLSM), activity measurement (leucine incorporation, AOC removal rate, respiration of benzoic acid, CTC and live/dead stains), and microbial diversity profiling (clone libraries and DGGE).

scholarly journals Application of DVC-FISH method in tracking Escherichia coli in drinking water distribution networks

2013 ◽  
Vol 6 (1) ◽  
pp. 25-31 ◽  
Author(s):  
L. Mezule ◽  
S. Larsson ◽  
T. Juhna
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Distribution Networks ◽  
Water Distribution Networks ◽  
Water Safety ◽  
E Coli ◽  
Drinking Water Distribution

Abstract. Sporadic detection of live (viable) Escherichia coli in drinking water and biofilm with molecular methods but not with standard plate counts has raised concerns about the reliability of this indicator in the surveillance of drinking water safety. The aim of this study was to determine spatial distribution of different viability forms of E. coli in a drinking water distribution system which complies with European Drinking Water Directive (98/83/EC). For two years coupons (two week old) and pre-concentrated (100 times with ultrafilters) water samples were collected after treatment plants and from four sites in the distribution network at several distances. The samples were analyzed for total, viable (able to divide as DVC-FISH positive) and cultivable E. coli. The results showed that low numbers of E. coli enters the distribution sytem from the treatment plants and tend to accumulate in the biofilm of water distribution system. Almost all of the samples contained metabolically active E. coli in the range of 1 to 50 cells per litre or cm2 which represented approximately 53% of all E. coli detected. The amount of viable E. coli significantly increased into the network irrespective of the season. The study has shown that DVC-FISH method in combination with water pre-concentration and biofilm sampling allows to better understand the behaviour of E. coli in water distribution networks, thus, it provides new evidences for water safety control.

Assessment of Lisbon drinking water distribution network biofilm colonization and associated hazards

2008 ◽  
Vol 8 (4) ◽  
pp. 421-426
Author(s):  
J. Menaia ◽  
M. Benoliel ◽  
A. Lopes ◽  
C. Neto ◽  
E. Ferreira ◽  
...  
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Network ◽  
Storage Tanks ◽  
Water Pipe ◽  
Cultural Methods ◽  
Drinking Water Distribution ◽  
And Storage

Concerns arise from the possible occurrence of pathogens in drinking water pipe biofilms and storage tank sediments. In these studies, biofilm samples from pipes and sediments from storage tanks of the Lisbon drinking water distribution system were analyzed. Protein determinations and heterotrophic counts on pipe biofilm samples were used to assess the Lisbon network sessile colonization intensity and distribution. Indicator and pathogenic microorganisms were analyzed in pipe biofilm samples, as well as in storage tanks biofilm and sediments, by using cultural methods and PCR, to assess risks. Results have shown that the Lisbon network sessile colonization is relatively weak in intensity. In addition, no meaningful hazards were apparent for both the network biofilm and the storage tanks biofilm and sediments.

Persistence and decontamination of surrogate radioisotopes in a model drinking water distribution system

2009 ◽  
Vol 43 (20) ◽  
pp. 5005-5014 ◽  
Author(s):  
Jeffrey G. Szabo ◽  
Christopher A. Impellitteri ◽  
Shekar Govindaswamy ◽  
John S. Hall
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Drinking Water Distribution System ◽  
Drinking Water Distribution

VULNERABILITY ASSESSMENT OF A DRINKING WATER DISTRIBUTION SYSTEM

2007 ◽  
Vol 2007 (1) ◽  
pp. 449-467
Author(s):  
Stacia L. Thompson ◽  
Elizabeth Casman ◽  
Paul Fischbeck ◽  
Mitchell J. Small ◽  
Jeanne M. VanBriesen
Keyword(s):  
Drinking Water ◽  
Vulnerability Assessment ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Drinking Water Distribution System ◽  
Drinking Water Distribution

Improving water age estimation in a drinking water distribution network by field study and digital modeling

2021 ◽  
Author(s):  
Jon Kristian Rakstang ◽  
Michael B. Waak ◽  
Marius M. Rokstad ◽  
Cynthia Hallé
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Network Model ◽  
Age Estimation ◽  
Water Distribution ◽  
Distribution Network ◽  
Distribution Networks ◽  
Plate Count ◽  
Water Age ◽  
Drinking Water Distribution

<p>Municipal drinking water distribution networks are complex and dynamic systems often spanning many hundreds of kilometers and serving thousands of consumers. Degradation of water quality within a distribution network can be associated to water age (i.e., time elapsed after treatment). Norwegian distribution networks often consist of an intricate combination of pressure zones, in which the transport path(s) between source and consumer is not easily ascertained. Water age is therefore poorly understood in many Norwegian distribution networks. In this study, simulations obtained from a water network model were used to estimate water age in a Norwegian municipal distribution network. A full-scale tracer study using sodium chloride salt was conducted to assess simulation accuracy. Water conductivity provided empirical estimates of salt arrival time at five monitoring stations. These estimates were consistently higher than simulated peak arrival times. Nevertheless, empirical and simulated water age correlated well, indicating that additional network model calibration will improve accuracy. Subsequently, simulated mean water age also correlated strongly with heterotrophic plate count (HPC) monitoring data from the distribution network (Pearson’s R= 0.78, P= 0.00046), indicating biomass accumulation during distribution—perhaps due to bacterial growth or biofilm interactions—and illustrating the importance of water age for water quality. This study demonstrates that Norwegian network models can be calibrated with simple and cost-effective salt tracer studies to improve water age estimates. Improved water age estimation will increase our understanding of water quality dynamics in distribution networks. This can, through digital tools, be used to monitor and control water age, and its impact on biogrowth in the network.</p>

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