Stress Response of Biofilm in Water Supply Network to Pre-disinfection of Sequential UV and Chlorine
This study sought to examine the change of biofilm in a simulated continuous-flow drinking water distribution system subjected to sequential UV and chlorine disinfection(UV-chlorine)treatments.The different doses of UV-chlorine disinfection were set up to compare the changes in microbial activity,community structure,extracellular polymeric substances(EPS),and metabolic characteristics of biofilm.In contrast to when chlorine disinfection was used,the bacteria in the biofilm following UV-chlorine disinfection displayed apparent aggregation.Gammaproteobacteria,Alphaproteobacteria,and Bacteroidia were the most prevalent bacteria in the biofilm,and residual chlorine had a more substantial impact on the dominant bacterial community than UV radiation.The amount of proteins was more than polysaccharides in EPS.The residual chlorine and UV dosage played an important role in the EPS content.Besides,the key bacterial genera Delftia,Stenotrophomonas,Sphingobium,Pseudomonas,and Methylobacterium had an impact on EPS production Pseudomonas,Methylobacterium,and Sphingobium had chlorine resistance,while Pseudomonas and Delftia were not UV resistant.Theoutcome of this study is bound to understand the biofilm in the pipeline and can provide references for studying the influence of UV-chlorine disinfection on the microbial safety of drinking water.
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维普
