期刊名称：Research Journal of Environmental and Earth Sciences
印刷版ISSN：2041-0484
电子版ISSN：2041-0492
出版年度：2012
卷号：4
期号：08
页码：807-817
出版社：Maxwell Science Publications
摘要：A study of a model drinking water distribution system, using previously used galvanized steel pipes, was carried out to evaluate the impact of temperature on the growth and survival of total coliform, E. coli and Heterotrophic Plate Count (HPC) bacteria for a maximum of 21 days residence time in the water phase in pipes and their respective glass control bottles. The study showed that for water temperatures of 15, 25 and 37ºC, HPC bacteria initially increased in the first 2-4 days but much higher at 37ºC after which the bacteria began to reduce in numbers. On the other hand, the decline in coliform and E. coli levels was observed after 24 h and this continued until no such bacteria were detected in the water phase. The oligotrophic nature of HPC bacteria allowed them to initially survive and grow in the nutrient-deficient environment, while the copiotrophic coliform and E. coli , which prefer nutritionally rich environments, began to die, hence the decline in their concentration. Whereas the decline in bacteria levels at lower temperatures of 15-25ºC may be attributed to starvation and/or the temperature effect, those at ~37ºC might have been significantly caused by the relatively higher temperature they were subjected to. The results, thus, established that higher water temperature was seen as important factor in reducing the survival of total coliform, E. coli and HPC bacteria in the water phase in drinking water pipes.
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