连续/间歇曝气MBBR-亚硝化工艺性能及N2O释放特性

采用移动床生物膜反应器（MBBR），利用载体固定化氨氧化菌（AOB），分别以连续曝气和间歇曝气方式长期平行运行两套MBBR亚硝化反应器（RC和RI反应器），分析对比不同曝气方式下亚硝化工艺性能和强温室气体（N₂O和NO）释放特性.结果表明：两种曝气方式均能实现亚硝化工艺，但RI出水NO₂^--N平均浓度较RC高20%左右，且出水NO₂^--N和NO₃^--N浓度波动性更小，因此间歇曝气条件下具有更好的亚硝化效果，更易形成稳定的亚硝化体系.在线测定两种体系N₂O和NO释放特性可知，RC比RI减少NO释放量约87.3%，增加N₂O释放量约57.5%.16S rDNA高通量测序结果表明，Nitrosomonas为AOB主要菌属，相对丰度最高分别为8%和10.06%，最低分别为2.19%和2.26%.间歇曝气方式下反应器可获得更高的AOB相对丰度.

MBBR-nitrification process performance and N2O emission characteristics with continuous/intermittent aeration regimes

In this study, a moving-bed Biofilm reactor (MBBR) was used to immobilize ammonia-oxidizing bacteria (AOB) on carriers. Two MBBR-AOB reactors were operated under continuous aeration (RC) and intermittent aeration (RI) in parallel. The variationsin the nitritation performance and nitrous oxide and nitric oxide emission characteristics were analyzed under different aeration regimes. The results showed that both aeration methods can achieve partial nitrification, but the average effluent concentration of NO₂^--N was approximately 20% higher in the RI than that in the RC; also, the degree of fluctuation of effluent NO₂^--N and NO₃^--Nwere smaller in the RI than that in the RC. Therefore, intermittent aeration mode had better nitritation performance, and it was easier to achieve a stable nitritation system. Online measurement of gaseous N₂O and NO showed that RC reduced the release of NO by about 87.3% and increased the release of N₂O by about 57.5%. The 16S rDNA high-throughput sequencing revealed that Nitrosomonas was the main AOB genus, and its highest relative abundance in the RC and RI modes was 8% and 10.06% respectively,and the lowest was 2.19% and 2.26% respectively. Our findings suggest running MBBR nitritation reactor with intermittent aeration mode couldachievea higher AOB relative abundance.