scholarly journals Influencing factors in the occurrence of injured coliforms in the drinking water distribution system in the city of La Plata, Argentina

2009 ◽  
Vol 8 (2) ◽  
pp. 205-211 ◽  
Author(s):  
María Alejandra Córdoba ◽  
Valeria Fernanda Del Coco ◽  
Marta Cecilia Minvielle ◽  
Juan Ángel Basualdo
Keyword(s):  
Drinking Water ◽  
Influencing Factors ◽  
Distribution System ◽  
Water Distribution ◽  
Membrane Filter ◽  
Klebsiella Oxytoca ◽  
Enterobacter Agglomerans ◽  
Drinking Water Contamination ◽  
La Plata ◽  
Drinking Water Distribution

The objective of this study was to evaluate the influencing factors in the occurrence of coliforms in the drinking water in La Plata (Argentina) from June 1999 to June 2001. A total of 180 samples were collected from Rio de La Plata (102 samples) and Puelche Aquifer (78 samples); 45 samples were collected for each of the four seasons. The membrane filter procedure was used for isolating bacteria, and each sample was tested for chlorine and pH. The highest percentage of samples positive for coliforms in the two tested media was obtained in summer while the highest percentage of negative samples was obtained in winter. No Escherichia coli was isolated. The percentage of injured coliforms fluctuated between 70 and 100%. The most frequently isolated bacteria was Enterobacter cloacae in summer, Enterobacter agglomerans in autumn and Klebsiella oxytoca in winter and spring. Significant correlations were observed between coliforms and the distance from the initial treatment point, and with the level of free chlorine. We conclude that drinking water contamination in La Plata occurs in the distribution system due to increased temperatures and reduced disinfectant levels, which result in bacterial regrowth.

scholarly journals Detection of drinking water contamination by an optical real-time bacteria sensor

2018 ◽  
Vol 1 (2) ◽  
pp. 160-168 ◽  
Author(s):  
B. Højris ◽  
S. N. Kornholt ◽  
S. C. B. Christensen ◽  
H.-J. Albrechtsen ◽  
L. S. Olesen
Keyword(s):  
Drinking Water ◽  
Real Time ◽  
Distribution System ◽  
Water Distribution ◽  
Grab Sampling ◽  
Drinking Water Contamination ◽  
Bird Droppings ◽  
Drinking Water Distribution ◽  
Bacteria Sensor ◽  
Pollution Events

Abstract In a drinking water distribution system, little is known about the characteristics of a microbiological pollution, how it enters the system, and how it can be detected. The drinking water industry has relied on various pollution indicators, through grab sampling and laboratory analyses, revealing results long after the water has been used. To be able to react more proactively to pollution events, many drinking water distributors supplement grab sampling with proportional sampling and/or real-time sensors. We have tested the ability of a new bacteria monitor to detect four different pollution events: wastewater intrusion, rainwater runoff, resuspension of drinking water sediments, and bird droppings entering the distribution system. The monitor response, in terms of bacteria and abiotic particle concentrations, was compared with traditional laboratory methods. The results illustrate the benefits of using such real-time bacteria sensors for monitoring the dynamics of drinking water microbiology and for early warning of potential pollution events.

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

Understanding and forecasting taste-and-odour formation in a drinking water distribution system: case study of Lyon (France)

2009 ◽  
Vol 9 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Elise Corbi ◽  
Valérie Jacquemet ◽  
Alain Quendo ◽  
Francine Manciot ◽  
Adeline Lamy ◽  
...  
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Distribution Network ◽  
Drinking Water Distribution ◽  
First Results ◽  
Mechanisms Of Formation

Lyon, France has the opportunity to distribute in abundance a groundwater resource with a good quality for drinking water. However, the length and the complexity of the distribution network can lead to consumer complaints in some areas of the water distribution system. In order to improve the organoleptic quality of distributed water, the water supplier wants to get a better understanding of potential taste and odour formation and to succeed in controlling it. Since 2006, activities have been taken with targeted analyses and sensory evaluation of water, taking into account both the consumers' private networks and the citywide distribution network. The first results were focused on the occurrence of bromophenols along the water distribution system, the understanding of the mechanisms of formation of such compounds, as well as their incidence on taste-and-odour events at the consumer's home.

scholarly journals The Seasonality of Nitrite Concentrations in a Chloraminated Drinking Water Distribution System

2018 ◽  
Vol 15 (8) ◽  
pp. 1756 ◽  
Author(s):  
Pirjo-Liisa Rantanen ◽  
Ilkka Mellin ◽  
Minna Keinänen-Toivola ◽  
Merja Ahonen ◽  
Riku Vahala
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Tap Water ◽  
Drinking Water Distribution System ◽  
Ammonium Oxidation ◽  
Water Age ◽  
Sampling Campaign ◽  
Drinking Water Distribution

We studied the seasonal variation of nitrite exposure in a drinking water distribution system (DWDS) with monochloramine disinfection in the Helsinki Metropolitan Area. In Finland, tap water is the main source of drinking water, and thus the nitrite in tap water increases nitrite exposure. Our data included both the obligatory monitoring and a sampling campaign data from a sampling campaign. Seasonality was evaluated by comparing a nitrite time series to temperature and by calculating the seasonal indices of the nitrite time series. The main drivers of nitrite seasonality were the temperature and the water age. We observed that with low water ages (median: 6.7 h) the highest nitrite exposure occurred during the summer months, and with higher water ages (median: 31 h) during the winter months. With the highest water age (190 h), nitrite concentrations were the lowest. At a low temperature, the high nitrite concentrations in the winter were caused by the decelerated ammonium oxidation. The dominant reaction at low water ages was ammonium oxidation into nitrite and, at high water ages, it was nitrite oxidation into nitrate. These results help to direct monitoring appropriately to gain exact knowledge of nitrite exposure. Also, possible future process changes and additional disinfection measures can be designed appropriately to minimize extra nitrite exposure.

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