Occurrence and Succession of Bacterial Community in O3/BAC Process of Drinking Water Treatment

In the drinking water industry, a common advanced treatment process is comprised of treatment with ozone, followed by biological-activated carbon (O-3/BAC). However, the bacterial community formation and succession procedures associated with activated carbon have rarely been reported. In this study, the dynamics of bacterial communities at three different depths were investigated using a pilot-scale O-3/BAC filter. The average chemical oxygen demand (CODMn), turbidity removal and dissolved oxygen (DO) consumption rate of the filter were 26.43%, 16.57% and 16.4% during the operation period, respectively. Bacterial communities dominated by proteobacteria and Bacteroidetes attached on activated carbon were determined by polymerase chain reaction-density gradient gel electrophoresis (PCR-DGGE). Principal component analysis (PCA) revealed that the compositions and structures of bacterial communities in different layers clustered after fluctuation. A redundancy analysis (RDA) indicated that Ramlibacter henchirensis was positively correlated to chemical oxygen demand (CODMn) removal and nitrate-N removal, and Georgfuchsia toluolica also showed a positive correlation with CODMn removal. Aquabacterium parvum and Phaeobacterium nitratireducens were positively-correlated with turbidity removal. Pedobacter glucosidilyticus and Pseudomonas sp. were associated with high dissolved oxygen (DO) consumption. These results provide insight into the succession characteristics of the bacterial community of O-3/BAC treatment and the interactions of the bacterial community with filter operation performance.