Biofilms and bacteriological water quality in a domestic installation model simulating daily drinking water consumption

2012 ◽  
Vol 12 (6) ◽  
pp. 720-726 ◽  
Author(s):  
Z. G. Tsvetanova ◽  
D. N. Dimitrov
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Temperature ◽  
Water Consumption ◽  
Bacterial Density ◽  
Plate Count ◽  
Hydrodynamic Characteristics ◽  
Pipe Material ◽  
Drinking Water Supply System ◽  
Pipe Materials

The biofilm formation potential of a drinking water supply system is related to the chemical, microbiological and hydrodynamic characteristics of water, and to the pipe materials in contact with water flow. The goals of this study were: to determine the biofilm dynamics in a model of four drinking water installations, to simulate daily household water consumption; to compare the biofilms developed on different polymer pipe materials and their influence on bacteriological water quality. The results demonstrated that bacterial density of biofilms depended on pipe material type and was influenced by water temperature. The biofilms on polyvinylchloride chlorinated and polyethylene materials had higher bacterial density than biofilms on polypropylene (PP) brands. The effect of the materials, and respectively the biofilms, on drinking water quality was stronger in the overnight stagnation periods, especially during the initial weeks of model operation, than in periods of water consumption. Heterotrophic plate count (HPC) in stagnant or in flowing waters and water temperature followed a similar curve pattern, demonstrating significant seasonal variations. In summer, the HPC values of stagnant waters were raised up to seven times higher than in winter and those of the outlet waters (during the consumption periods) were raised up to four times.

Water Quality Violations and Avoidance Behavior: Evidence from Bottled Water Consumption

2011 ◽  
Vol 101 (3) ◽  
pp. 448-453 ◽  
Author(s):  
Joshua Graff Zivin ◽  
Matthew Neidell ◽  
Wolfram Schlenker
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Willingness To Pay ◽  
Water Consumption ◽  
Avoidance Behavior ◽  
Bottled Water ◽  
Poor Water Quality ◽  
Using Data ◽  
The Impact

We examine the impact of poor water quality on avoidance behavior by estimating the change in bottled water purchases in response to drinking water violations. Using data from a national grocery chain matched with water quality violations, we find an increase in bottled water sales of 22 percent from violations due to microorganisms and 17 percent from violations due to elements and chemicals. Back-of-the envelope calculations yield costs of avoidance behavior at roughly $60 million for all nationwide violations in 2005, which likely reflects a significant understatement of the total willingness to pay to eliminate violations.

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>

scholarly journals Degradation of Bacterial Water Quality in Drinking Water after Bottling

2020 ◽  
Vol 14 (1) ◽  
pp. 78-83
Author(s):  
Ali Shahryari ◽  
Charlotte D. Smith ◽  
Abolfazl Amini
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Heterotrophic Bacteria ◽  
Positive Association ◽  
Ambient Air ◽  
Bottled Water ◽  
Plate Count ◽  
Biochemical Tests ◽  
Storage Duration

Background: The consumption of bottled water globally, including Iran, has increased tremendously in recent years. This study was designed to assess the bacteriological quality of bottled water and its compliance with the drinking water regulations. In addition, we evaluated bottled waters for the presence of a variety of genera of bacteria and the effect of storage duration on the extent of bacterial contamination. Methods: Four hundred samples of bottled water belonging to ten different Iranian brands with various production dates were purchased from supermarkets in Gorgan, Iran, from 2017 to 2018. Bacterial quality of bottled water was assessed using heterotrophic plate count (HPC) followed by usual biochemical tests for identification of bacterial genera, and by the API system. Results: The average HPC of bottled water was 9974 colony-forming units per milliliter (CFU/ml). Twelve genera were isolated, among which Bacillus spp. and Escherichia coli were the most and least abundant, respectively. Statistical analysis showed that there was a positive association between water quality and storage duration so that the highest microbial load occurred within the first to third months after bottling. Furthermore, the highest rate of contamination was observed in May when ambient air temperatures commonly reached 40 °C. Conclusion: The bacterial quality of bottled water was not according to the standard of drinking water quality. This study demonstrated the variation in bacterial levels after bottling, which indicates the presence of waterborne heterotrophic bacteria, some of which can pose severe health risks to consumers.

scholarly journals Temperature Impact on Drinking Water Consumption

2020 ◽  
Vol 2 (1) ◽  
pp. 31
Author(s):  
Dejan Dimkić
Keyword(s):  
Drinking Water ◽  
Water Consumption ◽  
Supply System ◽  
Water Losses ◽  
Production And Consumption ◽  
Consumption Rates ◽  
Drinking Water Supply System ◽  
Temperature Impact ◽  
Time Of Year ◽  
Industrial Demand

The production of water in a drinking water supply system (WSS) comprises all drinking water enter in the net, while the consumption of water generally comprises all billed amounts of water in a WSS. The production and consumption of water in a drinking WSS depend on different factors. Consumption rates depend on the consumer structure and habits, industrial demand, time of year, water pricing, climatic variables, secondary water losses and many other factors. One of the interesting factors is air temperature. It is especially important in the frame of climate change and global warming. Temperature impact on water consumption in a WSS is not uniform temporally (particularly throughout the year) and spatially (different climate regions and countries, different habits and different conditions in each WSS). Obtained correlations for the two biggest cities in Serbia (Belgrade and Niš) are presented in the paper and compared with some examples worldwide.

scholarly journals Drinking Water Quality Risk Management. Risk Analysis of Nitrogen Groundwater Contamination Using Analytica Software

2019 ◽  
Vol 70 (11) ◽  
pp. 3971-3976
Author(s):  
Alice Iordache ◽  
Alexandru Woinaroschy
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Risk Analysis ◽  
Water Supply ◽  
Drinking Water Supply ◽  
Integrated Method ◽  
System Risk ◽  
Health Quality ◽  
Drinking Water Supply System

Drinking water supply is essential for public health, quality of life, sustainable development of economic activity, and environmental protection. In this context, it is important to ensure continuous improvement of all stages of processes to guarantee water quality and safety [1]. The main objectives of the study are: -development of an integrated method and probable risk analysis for a drinking water supply system; -risk assessment of contamination of raw water with nitrate [2].

scholarly journals Household stored water quality in an intermittent water supply network in Panama

2020 ◽  
Vol 10 (2) ◽  
pp. 298-308
Author(s):  
Carlos I. Gonzalez ◽  
John Erickson ◽  
Karina A. Chavarría ◽  
Kara L. Nelson ◽  
Amador Goodridge
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Supply ◽  
Water Storage ◽  
Total Coliform ◽  
Drinking Water Supply ◽  
Coliform Bacteria ◽  
Plate Count ◽  
Probable Number ◽  
Total Coliform Bacteria

Abstract Safe water storage is critical to preserve water quality, especially when intermittent piped drinking water supply creates a need for household storage. This study characterized household storage practices and stored water quality in 94 households (N = 94) among four peri-urban neighborhoods in Arraiján, Panama with varying degrees of supply intermittency. We found that 18 (19.1%) households stored drinking water in unsafe containers. Forty-four (47%) samples of household stored drinking water had residual chlorine levels <0.2 mg/L. While 33 (35.1%) samples were positive for total coliform bacteria, only 23 (24.4%) had >10 most probable number (MPN)/100 mL total coliform bacteria. Eight (44%) samples were positive for Escherichia coli, whereas only one (1.3%) sample from the safe containers was positive. Twenty-nine (30.9%) samples had >500 MPN/mL heterotrophic plate count bacteria. These findings suggest that longer supply interruptions were associated with longer storage times and lower chlorine residual, which were associated with higher concentrations of indicator bacteria. This is one of the first studies in the Central-American region to show an association between the lack of turnover (replacement with fresh water) and greater contamination during household water storage. Thus, when drinking water supply is not completely continuous and household storage is required, decreasing the time between supply periods can facilitate safer water storage. Public awareness and education are also recommended to increase hygiene practices during water collection and storage.

Pipe material and water quality in a holistic view

2001 ◽  
Vol 1 (3) ◽  
pp. 1-10
Author(s):  
T. Hedberg
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Distribution Networks ◽  
Pipe Material ◽  
Treatment Technology ◽  
Water And Wastewater Treatment ◽  
Holistic View ◽  
General Terms ◽  
Research Activities

The new trends in societies towards sustainable development have necessitated a new way of thinking regarding water treatment, the distribution of drinking water and wastewater treatment. A process of implementing new European water directives is ongoing and the consequences and need for coordination of these changes are discussed. Raw water qualities, water treatment technology and drinking water quality have impacts on water quality deterioration in the distribution networks that negatively affect the possibilities for recycling sewage sludge containing valuable nutrients. Measures for coping with these issues are discussed in general terms and suggestions for future strategies and research activities are given.

PSIX-8 Drinking water acidification and chlorination improves microbiological water quality without detrimental effects on performance or hazard side-effects in bulls fed high-concentrate diets

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 438-439
Author(s):  
Marçal Verdú ◽  
Sonia Marti ◽  
Joan Riera ◽  
Carles Medinya ◽  
Jordi Cucurull ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Side Effects ◽  
Water Consumption ◽  
Total Coliform ◽  
Feed Consumption ◽  
Apparent Digestibility ◽  
Coliform Count ◽  
Microbiological Water Quality ◽  
Holstein Bulls

Abstract The aim of this study was to evaluate the effect of drinking water disinfection (chlorination) and conditioning (acidification) on microbiological water quality, water and feed consumption, total tract apparent digestibility and its potential hazard effects on animal health in Holstein bulls fed high-concentrate diets. Twenty-four Holstein bulls (221 ± 20.9 kg of initial BW, and 184 ± 9.9 d of age) were housed individually and fed ad libitum. Animals were assigned to 4 treatments with a 2 x 2 factorial design: drinking water conditioning (with or without acidification) and disinfection (absence or chlorination). Every 28 d, water samples from the tank and drinker were collected to analyze pH, residual chlorine and microbial load. Water consumption was recorded daily, and every 2 wks feed consumption and BW were recorded. At d 0, 14, 98 and 196 blood samples were collected to hematology and clinical chemistry analysis. At d 42 and 147 total tract apparent digestibility was estimated. Data were analyzed with a mixed effects model. In the tank, acidification increased residual free chlorine (0.58 vs. 0.33 ± 0.081 ppm, interaction, P = 0.10) and chlorination reduced (P < 0.01) total coliform count (0.8 vs. 392.7 ± 0.30 CFU / 100 ml) and Clostridium perfringens count (0.0 vs. 9.0 ± 0.13 CFU / 100 ml). In the drinkers, chlorination only tended (P = 0.10) to decrease total coliform count (967.5 vs. 994.7 ± 0.01 CFU / 100 ml). Treatments did not affect daily water consumption, total DMI nor blood parameters. At the end of the study, chlorination tended (P = 0.07) to improve starch total apparent digestibility (98.2 vs 97.7 ± 0.28 %). In fattening bulls’, the conditioning (acidification) and disinfection (chlorination) of drinking water improved its microbiological quality without detrimental effects on water and feed consumption, ruminal digestibility or hazard side-effects.

Effect of temperature and pipe material on biofilm formation and survival of Escherichia coli in used drinking water pipes: a laboratory-based study

2006 ◽  
Vol 54 (3) ◽  
pp. 49-56 ◽  
Author(s):  
J. Silhan ◽  
C.B. Corfitzen ◽  
H.J. Albrechtsen
Keyword(s):  
Drinking Water ◽  
Biofilm Formation ◽  
Water Phase ◽  
Effect Of Temperature ◽  
Plate Count ◽  
Pipe Material ◽  
E Coli ◽  
Water Pipes ◽  
Higher Temperature ◽  
Static Conditions

Segments of used drinking water pipes of galvanised steel (GS), cross-linked polyethylene (PEX), copper pipes (Cu) or new medium-density polyethylene (PE) were investigated for the formation of biofilm and survival of E. coli in biofilm and in the water phase. Pipes were filled with water and incubated at 15 °C or 35 °C under static conditions. Biofilm formation was followed during 32, 40 and 56 (58) d. The most dense biofilm was formed on GS, reaching approximately 4.7×105 CFU/cm2 measured as heterotrophic plate count (HPC), and at the other materials the density reached 3×103 CFU/cm2 on PE and PEX and 5×101 and 5×102 CFU/cm2 on Cu pipes after 58 d at 15 °C. Biofilm HPC values were higher at 35 °C than at 15 °C, with only slightly higher values on the metals, but 100-fold higher on PE and PEX. Adenosine triphosphate (ATP) measurements confirmed the general trends observed by HPC. Higher temperature was seen to be an important factor reducing E. coli survival in the water phase in drinking water pipes. At 15 °C E. coli survived more than 4 d in GS and Cu pipes and 8 d in PE pipes, but was not detected after 48 h at 35 °C. The E. coli survived longer at both temperatures in the glass control bottles than in the drinking water pipes. Despite the obvious biofilm formation, E. coli was not detected in the biofilm at any of the investigated surfaces.

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