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

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.

2005 ◽  
Vol 14 (6) ◽  
pp. 487-493 ◽  
Author(s):  
Bilge Hapcioglu ◽  
Yildiz Yegenoglu ◽  
Zayre Erturan ◽  
Yasar Nakipoglu ◽  
Halim Issever

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 668
Author(s):  
Alexandra Spyropoulou ◽  
Yannis G. Lazarou ◽  
Chrysi Laspidou

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.


2019 ◽  
pp. 419-440
Author(s):  
Anita Benes

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.


2003 ◽  
Vol 47 (5) ◽  
pp. 149-154 ◽  
Author(s):  
J.W. Santo Domingo ◽  
M.C. Meckes ◽  
J.M. Simpson ◽  
B. Sloss ◽  
D.J. Reasoner

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.


2009 ◽  
Vol 43 (4) ◽  
pp. 1075-1087 ◽  
Author(s):  
Alex Francisque ◽  
Manuel J. Rodriguez ◽  
Luis F. Miranda-Moreno ◽  
Rehan Sadiq ◽  
François Proulx

2005 ◽  
Vol 52 (8) ◽  
pp. 181-189 ◽  
Author(s):  
J. Långmark ◽  
M.V. Storey ◽  
N.J. Ashbolt ◽  
T.A. Stenström

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.


Sign in / Sign up

Export Citation Format

Share Document