温度对AO-MBR运行效果及微生物菌群的影响

监测缺氧-好氧膜生物反应器(AO-MBR)长期运行过程中的膜污染特性、脱氮效果和微生物菌群特征变化,以考察温度的影响。结果发现,随着温度的上升,AO -MBR的平均膜清洗周期由冬季低温时的18d延长至夏季高温时的30d,这可能与污泥黏度、EPS含量和微生物菌群变化有关。在夏季高温时,虽然AO-MBR的污泥总氮负荷较高,但是仍有出水氨氮和总氮浓度低于冬季低温时。对污泥的微生物菌群进行分析发现,夏季的菌群多样性较高,而且参与脱氮的Nitrospirae、Acidobacteria和Plandomycetes相对丰度较高,这可能是夏季脱氮效果较好的原因之一。

Effect of Temperature on Performance and Microbial Community of AO-MBR

The membrane fouling, nitrogen removal effect and microbial community of an anoxic- oxic membrane bioreactor ( AO-MBR) during long-term operation were systematically investigated under different temperatures. The results showed that the average membrane cleaning cycle of the AO-MBR was increased from 18 days to 30 days with the temperature increasing from a low value in the winter to a high value in the summer. This might be related to the change of sludge viscosity, EPS content and microbial community. Although TN load of the sludge in the AO-MBR was higher at high temperature in the summer than that in the winter, the NH4^+;- N and TN concentration in the effluent were lower in some days in the summer than that in the winter. It was found that the sludge had higher diversity in summer according to analysis of the microbial community, and the relative abundance of Nitrospirae, Acidobacteria and Plandomycetes which played a key role in nitrogen removal was higher than those in the winter. This might explain why effective removal of nitrogen was obtained in the summer.