不同电子受体除磷污泥相似性与菌群结构研究

分别以硝酸盐、亚硝酸盐、氧气为电子受体,采用3组SBR反应器培养除磷污泥,连续126d的稳定运行表明:以硝酸盐、亚硝酸盐、氧气为电子受体除磷污泥对TP平均去除率分别为84.8%, 78.7%, 87.4%,出水TP平均浓度分别为0.758, 0.931, 0.632mg/L.采用高通量测序技术对不同电子受体除磷污泥的相似性与菌群结构进行了研究,结果表明,以硝酸盐,亚硝酸盐为电子受体的反硝化除磷污泥具有近似的菌群结构,与好氧除磷污泥菌群结构差异较大.基于各样品主导OTUs序列的系统发育关系及其比例的分布,主导微生物主要可以分为5个簇.通过序列比对,在97%的序列相似度条件下,种泥中聚磷菌与聚糖菌序列比例为0.716%与0.368%,以硝酸盐、亚硝酸盐、氧气为电子受体除磷污泥中聚磷菌与聚糖菌序列比例分别为1.78%, 2.53%, 4.80%与1.44%, 1.32%, 30.9%,厌氧-缺氧条件有利于抑制聚糖菌.亚硝酸盐为反硝化除磷污泥电子受体时潜在公共卫生安全隐患.

Microbial similarity and community structure of phosphorus removal sludge with different electron acceptors

Phosphorus removal sludge with nitrate, nitrite and oxygen as the sole electron acceptor were acclimatized in three parallel sequencing batch reactors, namely RN03, RN02 and R02 respectively. Operation results showed that phosphorus removal rates were 84.8%, 87.4% and 78.7% on average for RN03, RN02 and R02, with effluent TP concentration of 0.758mg/L, 0.931mg/L and 0.632mg/L. High-throughput technology was employed to evaluate the microbial similarity and community structure of phosphorus removal sludge with different electron acceptors. Results indicated that denitrifying phosphorus removal sludge with nitrate and nitrite as electron acceptors exhibited similar bacterial community structure and was distinct from that of aerobic phosphorus removal sludge. The dominant microbial organisms were clustered into five clades based on the phylogenetic relationship of the significant OTUs sequences. Through sequence BLAST, 0.716%, 1.78%, 2.53% and 4.80% of sequences from Seed, RN03, RN02 and R02 could be assigned to Accumulibacter-like sequences at similarity level of 97%; 0.368%, 1.44%, 1.32% and 30.9% of sequences could be assigned to GAO-like sequences, indicating that alternating anaerobic-anoxic condition was favorable toward elimination of GAO. Moreover, potential public health hazard was revealed for nitrite based denitrifying phosphorus removal sludge.