Biofilms in an urban water distribution system: measurement of biofilm biomass, pathogens and pathogen persistence within the Greater Stockholm area, Sweden

2005 ◽  
Vol 52 (8) ◽  
pp. 181-189 ◽  
Author(s):  
J. Långmark ◽  
M.V. Storey ◽  
N.J. Ashbolt ◽  
T.A. Stenström
Keyword(s):  
Distribution System ◽  
Pilot Plant ◽  
Water Distribution ◽  
Water Distribution System ◽  
Microbial Pathogens ◽  
Urban Water ◽  
Uv Treatment ◽  
Aesthetic Quality ◽  
Wide Range ◽  
The Impact

Distribution pipe biofilms can provide sites for the concentration of a wide range of microbial pathogens, thereby acting as a potential source of continual microbial exposure and furthermore can affect the aesthetic quality of water. In a joint project between Stockholm Water, the MISTRA “Sustainable Urban Water” program, the Swedish Institute for Infectious Disease Control and the Royal Technical University, Stockholm, the aim of the current study was to investigate biofilms formed in an urban water distribution system, and quantify the impact of such biofilms on potential pathogen accumulation and persistence within the Greater Stockholm Area, Sweden. When used for primary disinfection, ultra-violet (UV) treatment had no measurable influence on biofilm formation within the distribution system when compared to conventional chlorination. Biofilms produced within a model pilot-plant were found to be representative to those that had formed within the larger municipal water distribution system, demonstrating the applicability of the novel pilot-plant for future studies. Polystyrene microspheres (1.0μm) and Salmonella bacteriophages demonstrated their ability to accumulate and persist within the model pilot-plant system, where the means of primary disinfection (UV-treatment, chlorination) had no influence on such phenomena. With the exception of aeromonads, potential pathogens and faecal indicators could not be detected within biofilms from the Stockholm water distribution system. Results from this investigation may provide information for water treatment and distribution management strategies, and fill key data gaps that presently hinder the refinement of microbial risk models.

scholarly journals Mercury Speciation in the Water Distribution System of Skiathos Island, Greece

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 668
Author(s):  
Alexandra Spyropoulou ◽  
Yannis G. Lazarou ◽  
Chrysi Laspidou
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Tap Water ◽  
World Health Organisation ◽  
World Health ◽  
Urban Water ◽  
Groundwater Salinization ◽  
The World ◽  
Standard Set

In recent years, mercury (Hg) concentration that exceeds the Maximum Contaminant Level Standard set by the World Health Organisation for drinking water has been detected in the groundwater of Skiathos Island in Greece. The island single source of urban water is groundwater; as a result, tap water has been characterised as unsafe for drinking and people rely on bottled water for their everyday needs. The origin and speciation of Hg in the aquifer is investigated with the use of the Pourbaix diagram, while the possible correlation with groundwater salinization due to seawater intrusion is examined.

Variations of DBPs precursors according to location within the distribution system

2009 ◽  
Vol 9 (4) ◽  
pp. 413-421
Author(s):  
C. Beaulieu ◽  
M. J. Rodriguez ◽  
J.-B. Sérodes
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Spatial Behavior ◽  
Haloacetic Acids ◽  
Formation Potential ◽  
The Impact ◽  
By Products

Little information is available on the evolution of remaining organic matter (ROM) in a water distribution system (WDS) and its impact on the generation of disinfection by-products (DBPs). This research involves the characterization, through sample fractionation processes and experimental chlorination tests, of the reactivity of DBP precursors occurring within a WDS. The study is based on samples collected in various locations of a WDS during a complete year. For each sample, six fractions were generated to determine their potential for formation of trihalomethanes (THMs) and haloacetic acids (HAAs). Fractionation processes on ROM demonstrated that the spatial behavior of precursors for THMs differs from that for precursors of HAAs. In addition, experimental chlorination tests showed that the reactivity of the investigated fractions, in terms of DBP formation potential (DBPfp), was different from each other according to location in the WDS. DBPfp for the studied fractions changed drastically during water treatment. However, changes of DBPfp for fractions were relatively low between the beginning and the extremity of the distribution system. Since the results of this research confirm that the ability to produce DBPs is related to the nature of the fractions, they could be useful to evaluate the impact of re-chlorination on DBP formation in a WDS.

Investigation of the Impact of Anti-Negative Pressure Facility on a Water Distribution System

2013 ◽  
Vol 316-317 ◽  
pp. 719-722
Author(s):  
Huan Huan Wang ◽  
Shu Ming Liu ◽  
Fan Lin Meng ◽  
Lu Bai
Keyword(s):  
Water Supply ◽  
Negative Pressure ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Simulation Method ◽  
Water Tank ◽  
Research Activities ◽  
High Level ◽  
The Impact

High level water tank is a commonly used facility to satisfy water demand for people living in high building, which is also the so-called secondary water supply system (SWSS) in China. Due to lack of maintenance, water quality problem has been frequently reported in the SWSS. In the last few decades, anti-negative pressure facility (ANPF) has emerged as a revolutionary approach for solving the pollution in the SWSS. ANPF makes good use of the municipal pipeline pressure, which is the improvement of traditional water supply. However, most of recent research activities mainly focus on the influence of part of water distribution system (WDS). In this paper, the software of EPANET has been applied in the SWSS calculation and simulation. Besides that, the SWSS with ANPF simulation method is proposed to evaluate the effect of other all nodes pressure in the WDS using hydraulic model. As the cases study, the paper analyzed two WDSs with ANPF. After simulation of the SWSS, the result of WDS, which is smaller, indicates that 6 out of the 9 nodes are affected with ANPF and that of WDS, which is larger, demonstrates that 37 out of the 41 nodes are affected and the affected nodes are focused on the confluent of pipes, especially around the ANPF.

scholarly journals The Roman aqueduct of Brigetio

2019 ◽  
pp. 419-440
Author(s):  
Anita Benes
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Urban Water ◽  
National Museum ◽  
Water Pipes ◽  
Archaeological Material ◽  
Literary Sources ◽  
Available Information

The aim of the present study is to examine the literary sources and the archaeological material regarding the aqueduct of Brigetio. Based on the available information the paper examines the problem of the localization of the source which supplied the aqueduct. The catalogue includes the descriptions of the lead and terracotta water pipes from Brigetio now in the Roman collection of the Hungarian National Museum. The results are presented with regards to the construction of the urban water distribution system.

Molecular characterization of bacteria inhabiting a water distribution system simulator

2003 ◽  
Vol 47 (5) ◽  
pp. 149-154 ◽  
Author(s):  
J.W. Santo Domingo ◽  
M.C. Meckes ◽  
J.M. Simpson ◽  
B. Sloss ◽  
D.J. Reasoner
Keyword(s):  
16S Rdna ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Heterotrophic Bacteria ◽  
Feed Water ◽  
Ammonia Oxidizing Bacteria ◽  
16S Rdna Pcr ◽  
The Impact

The objective of this study was to monitor the impact of chlorination and chloramination treatments on heterotrophic bacteria (HB) and ammonia-oxidizing bacteria (AOB) inhabiting a water distribution system simulator. HB densities decreased while AOB densities increased when chloramine was added. AOB densities decreased below detection limits after the disinfection treatment was switched back to chlorination. The presence of AOB was confirmed using a group-specific 16S rDNA-PCR method. 16S rDNA sequence analysis showed that most bacterial isolates from feed water, discharge water, and biofilm samples were α-Proteobacteria or β-Proteobacteria. The latter bacterial groups were also numerically dominant among the sequences recovered from water and biofilm 16S rDNA clone libraries. The relative frequency of each culturable bacterial group was different for each sample examined. Denaturing gradient gel electrophoresis analysis of total community 16S rDNA genes showed notable differences between the microbial community structure of biofilm samples and feed water. The results of this study suggest that disinfection treatments could influence the type of bacterial community inhabiting water distribution systems.

A comparison of methods and models for the analysis of water distribution pipe biofilms

2002 ◽  
Vol 2 (4) ◽  
pp. 73-80 ◽  
Author(s):  
M.V. Storey ◽  
N.J. Ashbolt
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Heterotrophic Bacteria ◽  
Urban Water ◽  
Bacterial Cells ◽  
Indicator Organisms ◽  
Protein Determination ◽  
Biofilm Growth ◽  
South Wales

The suitability of three experimental devices: biofilm reactors™ (BR), biofilm exosamplers™ (BE), and modified robbins devices (MRD), for the analysis of water distribution pipe biofilms was examined in situ within an urban water distribution system (Rouse Hill Development Area, New South Wales). Stainless steel (ss) and unplasticized polyvinyl chloride (uPVC) coupons were conditioned with biofilm in each device for a period of 70 days. Biofilm removal techniques (sonication and stomaching) were evaluated and optimized for this study. A multiparametric quantification of biofilm biomass using total protein (NanoOrange™ protein determination) and carbohydrate (phenol-sulfuric assay) content, total number of bacterial cells (BacLight™ Live/Dead® Bacterial Viability Kit) and total number of heterotrophic bacteria (R2A plate counts) is proposed. The presence of biofilm-associated faecal indicator organisms (Enterococci, E. coli, somatic, F-RNA and B40-8 bacteriophages) was assayed for each biofilm homogenate. Variability both within and between biofilm devices was observed. Notwithstanding the shortcomings of the inherent heterogeneity observed with biofilm quantification, the relatively inexpensive biofilm devices were shown to yield reliable and comparable information on biofilm growth within an urban water distribution system. Furthermore, the multiparametric measurement of biofilm biomass was shown to provide a reliable and holistic quantification of distribution pipe biofilms.

scholarly journals Fractal-based Planning of Urban Water Distribution System in China

2014 ◽  
Vol 89 ◽  
pp. 886-892 ◽  
Author(s):  
S. Qi ◽  
J. Ye ◽  
J. Gao ◽  
W. Wu ◽  
J. Wang ◽  
...  
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Urban Water

scholarly journals Near-optimal scheduling of device activation in water distribution systems to reduce the impact of a contamination event

2011 ◽  
Vol 14 (2) ◽  
pp. 345-365 ◽  
Author(s):  
S. Alvisi ◽  
M. Franchini ◽  
M. Gavanelli ◽  
M. Nonato
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Optimal Scheduling ◽  
Mixed Integer ◽  
Maximum Speed ◽  
Contaminated Water ◽  
Flow Control Devices ◽  
The Impact

This paper proposes an innovative procedure for identifying, in the event of accidental or intentional contamination of a water distribution system, the optimal scheduling of activation of a pre-selected set of flow control devices which will serve to minimise the volume of contaminated water consumed by users after the detection of the contaminant in the system. The constraints are represented by the number of available response teams and the maximum speed at which these teams can travel along the roadway. The optimal scheduling of device activation is sought by means of an optimisation process based on a genetic algorithm (GA) which interacts with a mixed integer linear programming (MILP) solver in order to ensure the feasibility of the scheduling identified. The optimisation procedure is coupled to a hydraulic and quality simulator, which enables a calculation of the volumes of contaminated water consumed by users, and a dynamic cache memory, which, by storing information on the system's behaviour as the optimisation process progresses, serves to limit the computational times. The application of the procedure to a highly complex real water distribution system shows that the optimisation process is robust and efficacious and produces a smaller volume of contaminated water consumed by the users than when the activation of all the devices was completed in the shortest amount of time.

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