不同溶解氧间歇曝气对亚硝酸盐氧化菌的影响

为了解溶解氧对间歇曝气模式下亚硝酸盐氧化菌（NOB）种群结构的影响，在以城市污水为处理对象，以间歇曝气方式运行的SBR反应器中，检测两种主要NOB菌（Nitrospira、Nitrobacter）在低溶解氧运行时期（55d）和高溶解氧运行时期（113d）数量及结构的变化.结果表明，在低溶解氧运行时期Nitrospira的含量远高于Nitrobacter的含量，与Candidatus Nitrospira defluvii相似性较高的菌种为Nitrospira的优势菌种；而进入高溶解氧运行时期后，Nitrospira含量逐渐降低，相反Nitrobacter含量逐渐升高成为主要NOB菌群，并且其大多数菌种与Nitrobacter winogradskyi菌相似.另外，在低溶解氧运行转变为高溶解氧运行阶段出现了一定的亚硝酸积累，并在Nitrobacter成为优势NOB菌群过程中逐渐消失.

Effect of dissolve oxygen on the microbial community of the nitrite-oxidizing bacteria in an intermittent aeration reactor

Nitrospira and Nitrobacter are two dominant types of nitrite-oxidizing bacteria (NOB).To evaluate the effect of dissolved oxygen (DO) on microbial community of NOB under the intermittent-aeration mode, the population and microbial community of this two NOB types were investigated in an aeration reactor with low DO period (55d) and high DO period (113d). Results showed the population of Nitrospira was much higher than that of Nitrobacter during the low DO period (0.2~0.5mg/L), and most clones of Nitrospira was very similar to the clone Candidatus Nitrospira defluvii. After increasing DO to a high level (1.5~2.3mg/L) and operating for 113d, Nitrobacter turned to the dominant group. Most clones of Nitrobacter were distributed to the branch containin Nitrobacter winogradskyi. Furthermore, the nitrite accumulation occurred in this reactor during the shift of population between Nitrospira and Nitrobacter after increasing DO, and it gradually disappeared when Nitrobacter became the dominant NOB group.