Molecular analysis of bacterial community in the tap water with different water ages of a drinking water distribution system

2018 ◽  
Vol 12 (3) ◽  
Author(s):  
Feng Wang ◽  
Weiying Li ◽  
Yue Li ◽  
Junpeng Zhang ◽  
Jiping Chen ◽  
...  
Keyword(s):  
Drinking Water ◽  
Bacterial Community ◽  
Molecular Analysis ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Tap Water ◽  
Drinking Water Distribution System ◽  
Drinking Water Distribution

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.

scholarly journals Spatiotemporal Changes of Antibiotic Resistance and Bacterial Communities in Drinking Water Distribution System in Wrocław, Poland

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2601
Author(s):  
Agata Siedlecka ◽  
Mirela Wolf-Baca ◽  
Katarzyna Piekarska
Keyword(s):  
Drinking Water ◽  
Antibiotic Resistance ◽  
Water Treatment ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Tap Water ◽  
Resistant Bacteria ◽  
Drinking Water Distribution System ◽  
Drinking Water Distribution

Antibiotic resistance of bacteria is an emerging problem in drinking water treatment. This paper presents the comparison of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) prevalence during the summer and winter season in a full-scale drinking water distribution system (DWDS) supplied by two water treatment plants (WTPs). The effect of distance from WTP and physical–chemical water parameters on its microbial properties was also tested. Bacterial consortia dwelling in bulk tap water were additionally compared by means of denaturating gradient gel electrophoresis (DGGE). The results showed that among ARB, bacteria resistant to ceftazidime (CAZ) were the most abundant, followed by bacteria resistant to amoxicillin (AML), ciprofloxacin (CIP), and tetracycline (TE). Numerous ARGs were detected in tested tap water samples. Only CAZ resistant bacteria were more prevalent in the season of increased antibiotic consumption, and only AML resistant bacteria relative abundances increase was statistically significant with the distance from a WTP. The investigated tap water meets all legal requirements. It is therefore safe to drink according to the law. Nevertheless, because antibiotic resistance could pose a threat to consumer health, it should be further monitored in DWDSs.

Role of inorganic phosphorus in controlling regrowth in water distribution system

1997 ◽  
Vol 35 (8) ◽  
pp. 37-44 ◽  
Author(s):  
A. Sathasivan ◽  
S. Ohgaki ◽  
K. Yamamoto ◽  
N. Kamiko
Keyword(s):  
Drinking Water ◽  
Organic Carbon ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Tap Water ◽  
Pure Water ◽  
Inorganic Phosphorus ◽  
Drinking Water Distribution System ◽  
Drinking Water Distribution

Conventionally organic carbon is assumed to be the limiting nutrient of regrowth. Inorganic phosphorus in comparison to carbon should be a good candidate for regrowth control because it can be measured and controlled. It may be able to limit regrowth in drinking water distribution systems. In order to clarify whether inorganic phosphorus can really control or limit regrowth, three kinds of bioassays were performed: 1. for different combinations of acetate, phosphorus, and other inorganic nutrients added to different test tubes containing pure water, 2. for different tap water dilutions with pure water, and 3. for different phosphorus addition to test tubes containing all nutrients but phosphorus. The inoculum used was taken from a drinking water distribution system carrying chlorinated groundwater. Results indicated the following: 1. tap water bacteria cannot grow on simple organic carbon source (acetate) alone, 2. not organic carbon but inorganic nutrients limited the growth in tap water, and 3. tap water bacterial growth was suppressed when phosphorus was not present and it was not affected by over-presence of phosphorus when carbon or other nutrients became limiting. This gave a clue that phosphorus might play a major role in controlling regrowth in drinking water distribution system.

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