[Microbial Community Structure for Sewage Wastewater Treatment Plants in Winter]

Constructing an effective control strategy for the daily operation of sewage treatment plants daily operation is an important criterion for the removal performances of nutrient stable in winter. To investigate microbial community structure, functional groups, and relationships between population dynamics and effluent variation, activated sludge obtained from 4 plants, which were running stably in a low temperature period (8-15℃) in northern China, were sampled. The high-throughput sequencing results indicated that the microbial community had good richness in the low temperature period during which the abundance of Actinobacteria increased. Nitrosomonas, a key functional ammonia oxidation bacterium, was greatly affected by the decreasing temperature, while Denitrifies, a highly diverse core group with wide distribution, maintained stable abundance indicating less influence of decreasing temperature. The denitrification efficiency was only associated with the mixed liquor reflux ratio. Tetrasphaera was widely present in four processes and played an important role for the removal of biological phosphorus. Sludge bulking phenomena caused by filamentous bacteria overgrowth occurred frequently in winter; however the quality of effluents was slightly influenced.