Biofilm microbial diversity under conditions of different pipe materials and chlorine residual levels

Microbial diversity and community structure of biofilm in water distribution network (WDN) was investigated through experiments in laboratory in order to secure water quality in WDN. The results suggested that the 47 identified bacteria strains belong to 18 genera from 13 families, among which Sphingobium and Micro-bacterium were dominant. 14 bacteria strains were isolated from cast iron pipes, whose microbial diversity was the highest, followed by stainless steel, 7 bacterial strains. Only three bacteria strains were isolated from polyethylene pipe. Sphingomonas existed in all the three types of pipe materials. Effect of chlorine residual on biofilm microbial diversity varies with pipe materials. Results of this research could support theoretical basis for the control of chlorine-resistant bacteria in WDN, enhancing water quality security in WDN.