N 2 O emission and bacterial community dynamics during realization of the partial nitrification process.

In this study, greenhouse gas emissions and microbial community succession during the realization of the partial nitrification (PN) process were studied. The results show that N 2 O emission mainly occurred in the aerobic stage and the PN reactor released about 20 mg of N 2 O gas each cycle. There is a positive correlation between the dissolved N 2 O concentration and the temperature of a typical cycle. High-throughput sequencing was used to illustrate succession in the microbial community structure. The most significant microfloral change during the PN startup process was that some aerobic bacteria were relatively enriched and some anaerobic bacteria were weeded out. The ammonia oxidizing bacteria (AOB) like Nitrosomonadaceae were enriched on account of the suitable external environment. Pseudomonas whose main function is denitrification declined and Planctomyces (anammox) showed the same tendency. This study comprehensively demonstrates the fluctuations of dissolved and emitted N 2 O while researching the succession of the microbial community in the culture of the PN process.