氨氮浓度对MBBR工艺中微生物群落结构的影响

采用移动床生物膜反应器（moving bed biofilm reactor，MBBR）处理模拟废水，考察进水氨氮浓度（20，30，50，100，200 mg/L）对MBBR工艺处理效果的影响，并利用16S rDNA高通量测序技术，分析微生物群落结构变化。结果表明:氨氮浓度为30~100 mg/L时，氨氮浓度越小，越有利于氨氮的去除，对COD去除率影响较小。氨氮浓度为20，50，200 mg/L时，Ottowia为第1优势菌属，相对丰度分别为66.76%、34.40%、53.88%，而氨氮浓度为30，100 mg/L时，Ottowia优势地位被Arcobacter、Hydrogenophaga等取代，说明微生物群落结构发生波动性变化可能与各类起反硝化作用的菌属和Ottowia菌属争夺优势地位有关。与自养型硝化作用有关的菌属相对丰度稳定在0.3%左右，相对丰度受氨氮浓度影响不大，高浓度氨氮对硝化菌属产生的抑制作用，可能是对其微生物活性的抑制。通过研究发现，进水氨氮浓度对MBBR生物膜中的微生物群落结构有一定的影响。

EFFECT OF AMMONIA-NITROGEN CONCENTRATION ON MICROBIAL COMMUNITY STRUCTURE IN A MBBR PROCESS

Moving bed biofilm reactor (MBBR) was used to treat simulated wastewater. The effect of ammonia-nitrogen concentration (20, 30, 50, 100, 200 mg/L) on the treatment efficiency of MBBR was investigated. By using 16S rDNA high-throughput sequencing technique, the changes in the microbial community structure of MBBR under different ammonia-nitrogen concentration were analyzed. The results indicated that the lower ammonia-nitrogen concentration, the more beneficial for the removal of ammonia nitrogen, but the less impact on the removal of COD, when ammonia-nitrogen concentration was 30~100 mg/L. When ammonia-nitrogen concentration was 20, 50 and 200 mg/L, Ottowia was the top dominant bacterial genus, whose relative abundances were 66.76%, 34.40%, 53.88%, respectively. When ammonia-nitrogen concentration was 30, 100 mg/L, Ottowia was replaced by Arcobacter, Hydrogenophag, etc. The fluctuation of microbial community structure may be related to the competition for dominant position between various denitrifying bacteria and Ottowia. The relative abundance of autotrophic nitrification bacteria was stable at about 0.3%, which was not affected by ammonia nitrogen concentration. The inhibiting effect of high concentration ammonia nitrogen on nitrifying bacteria might be due to the inhibition of their microbial activity. The influent ammonia-nitrogen concentration affected the microbial community structure in MBBR biofilm.