scholarly journals Variations in bacterial cell counts and water quality parameters in the MWRA drinking water distribution system

2020 ◽  
Author(s):  
◽  
Jill Gosnell
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Distribution System ◽  
Bacterial Cell ◽  
Water Distribution ◽  
Water Distribution System ◽  
Quality Parameters ◽  
Drinking Water Distribution System ◽  
Cell Counts ◽  
Drinking Water Distribution

scholarly journals PHYSICO-CHEMICAL AND BACTERIOLOGICAL COMPOSITION IN A METROPOLITAN DRINKING WATER DISTRIBUTION SYSTEM IN KATHMANDU

2017 ◽  
Vol 22 (1) ◽  
pp. 159-164
Author(s):  
Pratima Tamrakar ◽  
Suman K. Shakya ◽  
Chitra B. Baniya
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Samples ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Drinking Water Distribution System ◽  
Chemical Parameters ◽  
Physico Chemical ◽  
Drinking Water Distribution

The study was concentrated on water quality appraisal in metropolitan drinking water distribution system in Kathmandu during 2011 to 2015 AD. The study covers 24 research areas from surface water sources, treatment plants, processing and water supply networks of public, private and community drinking water suppliers in the main city of Kathmandu valley. Water quality was analyzed under six physical, seventeen chemical and two bacteriological parameters. All tests were conducted in accordance with the procedures laid down in the Standard Methods. Total 320 samples collected during two years of periods. The physico-chemical parameters of tested water samples from sources, reservoirs and taps were found to be within the range of National Drinking Water Quality Standard (NDWQS). The turbidity and pH values for most of the tested water samples from sources, reservoirs and taps except for a few source and tap samples were found to be within the NDWQS guideline values. The chemical parameters values of majority of tested source water samples were below the maximum level. The values of iron, manganese, sodium and chloride content of some source samples were found higher than the maximum permissible level recommended by NDWQS and WHO guideline. Bacteriologically, larger proportion of water samples (sources, reservoirs and taps) were found to be unacceptable. The present study disclosed fecal contamination to be the major problem in drinking water from source to the distribution for city water supply systems in selected metropolitan areas. The physico-chemical qualities of water in most cases were within acceptable limit.Journal of Institute of Science and TechnologyVolume 22, Issue 1, July 2017, page: 159-164

scholarly journals Mapping Dynamics of Bacterial Communities in a Full-Scale Drinking Water Distribution System Using Flow Cytometry

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2137 ◽  
Author(s):  
Caroline Schleich ◽  
Sandy Chan ◽  
Kristjan Pullerits ◽  
Michael D. Besmer ◽  
Catherine J. Paul ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Drinking Water ◽  
Distribution System ◽  
Bacterial Communities ◽  
Water Distribution ◽  
Water Distribution System ◽  
Time Correlation ◽  
Drinking Water Distribution System ◽  
Cell Counts ◽  
Drinking Water Distribution

Microbial monitoring of drinking water is required to guarantee high quality water and to mitigate health hazards. Flow cytometry (FCM) is a fast and robust method that determines bacterial concentrations in liquids. In this study, FCM was applied to monitor the dynamics of the bacterial communities over one year in a full-scale drinking water distribution system (DWDS), following implementation of ultrafiltration (UF) combined with coagulation at the drinking water treatment plant (DWTP). Correlations between the environmental conditions in the DWDS and microbial regrowth were observed, including increases in total cell counts with increasing retention time (correlation coefficient R = 0.89) and increasing water temperature (up to 5.24-fold increase in cell counts during summer). Temporal and spatial biofilm dynamics affecting the water within the DWDS were also observed, such as changes in the percentage of high nucleic acid bacteria with increasing retention time (correlation coefficient R = −0.79). FCM baselines were defined for specific areas in the DWDS to support future management strategies in this DWDS, including a gradual reduction of chloramine.

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