强化反硝化除磷对A^2O工艺微生物种群变化的影响

Effect of enhancing denitrifying phosphorus removal on microbial population variation in A^2O process

强化A2O工艺中的反硝化除磷比例,是提高该工艺处理低C/N比污水时脱氮除磷效率的有效途径。采用52.5 L的A2O反应器处理实际生活污水,研究了系统在不同的反硝化除磷比例情况下微生物的种群变化及关系。试验结果表明,随着水质条件及运行状态的改变,系统反硝化除磷的比例也在变化,同时微生物种群结构表现为一种动态的演替过程,工艺条件与微生物的种群结构具有很强的映射关系。测序结果表明,具有传统除磷功能的Acinetobacter在系统反硝化除磷得到强化的时候会逐渐被淘汰,而Uncultured Chlorobi bacterium会逐渐得到增殖,可能是系统中具有反硝化除磷功能的微生物。

Enhanced denitrifying phosphorus removal in anaerobic-anoxic/oxic （A^2O） process is an effective way to increase the removal efficiency of nitrogen and phosphorus when treating low C/N ratio domestic wastewater. In this study, a 52.5L pilot-scale reactor, based on plug-flow A^2O configuration, was used to treat domestic wastewater. In addition, the microbial population variation was investigated by polymerase chain reaction-denaturing gradient gel electrophoresis （PCR DGGE）. The results showed that the microbial community structure and dominant bacteria changed with the variation of wastewater quality and operating parameters. The dynamic change of microbial population was consistent with the variation of operation. Sequence results of DGGE bands showed that the dominant bacterial community in the system was Proteobacteria. Acinetobacter may be responsible for the traditional biological phosphorus removal in the system, but it disappeared gradually with the enhancement of denitrifying phosphorus removal.Uncultured Chlorobi bacterium increased with the enhancement of denitrifying phosphorus removal and it might be the major denitrifying phosphate accumulating organisms （DPAOs） in the system.