长期低聚磷条件对AO-SBR系统Accumulibacter代谢特性的影响

Effects of Long-term Poly-P Deficiency on the Metabolic Properties of Accumulibacter in AO-SBR System

为了考察长期低聚磷(Poly-P)条件下Accumulibacter的菌群结构及其代谢特性的变化,采用两个SBR反应器,分别采用乙酸钠和丙酸钠为有机碳源,接种富含Accumulibacter的活性污泥,在进水PO34--P浓度为2. 5 mg·L^(-1)的低磷进水条件下运行60 d,对系统除磷性能、污泥浓度、主要菌群结构的变化进行研究.结果表明,长期低Poly-P条件下两个SBR系统均表现出良好的除磷和去除有机物的性能,但两个系统内的菌群代谢均表现出聚糖菌代谢特征;运行60 d后,丙酸盐系统中AccumulibacterⅠ型仍保持了较高的丰度(40%±7%),表明丙酸盐SBR系统中AccumulibacterⅠ型不仅具有较高的代谢活性,还能够在长期低聚磷条件下以一种不依赖Poly-P的代谢方式进行生存;对比发现,丙酸盐碳源更有利于Accumulibacter适应低磷负荷的运行环境,且在低磷负荷的运行环境下AccumulibacterⅠ型比Ⅱ型更具竞争优势.

To investigate the changes in microbial community structure and metabolic properties of Accumulibacter under long-term Poly-P deficiency,an activated sludge enriched with Accumulibacter was inoculated into two SBR reactors,where sodium acetate and sodium propionate were used separately as organic carbon sources.The two reactors were operated for 60 days with an influent PO34--P concentration of 2.5 mg·L-1.The phosphorus removal performance,sludge production,and changes in the microbial community structure of the systems were analyzed.The results indicated that both SBR systems showed good performance of phosphorus and organic matter removal.However,microorganisms in both systems showed glycogen-accumulating metabolism properties under longterm Poly-P deficiency.In the unfavorable environment of long-term Poly-P deficiency,AccumulibacterⅠmaintained a high abundance(40%±7%)in the propionate SBR system,indicating that AccumulibacterⅠhad higher metabolic activity and its metabolic properties could be independent of Poly-P for survival under Poly-P deficiency for a long period.In comparison,propionate is more conducive to Accumulibacter adaptation to lower phosphorus loads,and AccumulibacterⅠis more competitive than AccumulibacterⅡunder lower phosphorus loads.