A/O工艺中污泥浓度对微生物群落结构的影响

Effects of sludge concentration on microbial community structure in A/O process

采用A/O工艺处理淀粉厂区废水,结合Miseq高通量测序技术研究了不同污泥浓度(MLSS)对A/O工艺脱氮效果及微生物群落结构的影响.结果显示,当污泥浓度为4066mg/L时(1号池),氨氮(NH_4^+-N)平均去除率高达90.2%;而污泥浓度为2985mg/L时(2号池),去除率仅为67.2%.两池体中优势菌门均为变形菌门、拟杆菌门、绿弯菌门和厚壁菌门,其中变形菌门和拟杆菌门平均丰度分别为40.65%、30.28%和25.25%、33.27%,其相对丰度比例差异较大.在功能基因层面,两池体中所有8个功能基因类别(KEGG,京都基因与基因组百科全书)排序相同,氮代谢相关基因中,硝化酶、反硝化酶、氨化酶的相关功能基因均在1号池中含量高.该工艺中污泥浓度对菌群结构影响显著,高污泥浓度有利于形成高效脱氮菌群结构.

The effect of different sludge concentration （MLSS） on denitrification efficiency and microbial community structure in A/O process for starch industry wastewater treatment were investigated. The 16S rDNA Miseq high throughput sequencing technique was used for bacterial commnutiy analysis. The results showed that the average removal rate of ammonia nitrogen （NH4＋-N） were respectively 90.2% and 67.2% when the concentration of sludge were 4066mg/L and 2985mg/L. The dominant bacteria were Proteobacteria, Bacteroidetes, Chloroflexi and Firmicutes in both of the pools; while the average abundance ratio of Proteobacteria and Bacteroides were 40.65% and 30.28% in the pool No. 1,25.25% and 33.27% in the pool No. 2respectively. In the functional gene level, all of the eight categories （KEGG, Kyoto Encyclopedia of Genes and Genomes） had a same order. The content of nitrogen metabolism related genes, such as, nitrifying ferments, denitrifying enzymes and ammonifying enzymes genes were higher in the pool No. 1. In this study, the sludge concentration has a significant effect on the bacterial structure, and the high sludge concentration is beneficial to the formation of high efficiency denitrifying bacterial community.