SEASONAL VARIATION OF MICROBIAL COMMUNITY FOR THE TREATMENT OF TAIL WATER IN CONSTRUCTED WETLAND

摘要

Effect of seasons and hydraulic loading rates (HLR) on the treatment performance and the response of the microbial community of vertical flow constructed wetland treating tail water were investigated. The seasonal treatment performance was evaluated at four HLR of 125, 250, 375 and 500 mm/d, respectively. The microbial community was detected by Miseq Illumina platform at HLR 125 and 375 mm/d. The wetland showed significant higher COD and TN, TP at HLR 125 mm/d, compared with other HLR. Overall removal efficiency were 61.47%, 71.40% and 76.31% for COD, TN and TP, respectively. While no significant difference for COD, TN and TP removal were found at HLR of 250, 375 and 500 mm/d. The best removal efficiency for COD and TN were achieved in summer and autumn while the best TP removal was achieved in winter. Nitrification bacteria (Nitrosomonas and Nitrospira) was significantly higher in HLR 125 mm/d, whereas sequences associated with denitrification has no significant difference at the two HLR. The results can partially explain the significant higher NH4+-N removal in HLR 125 mm/d and relatively low nitrogen performance in winter.