厌氧氨氧化启动过程及微生物群落结构特征

采用UASB反应器以体积比1∶2接种实验室培养的具有厌氧氨氧化(ANAMMOX)功能的厌氧污泥和城市污水厂的好氧污泥,耗时17 d成功启动ANAMMOX反应,启动阶段分为菌体水解期、活性提高期和稳定运行期.稳定运行后,逐步提高反应器容积负荷富集厌氧氨氧化菌,当容积负荷由0.10 kg·(m~3·d)~(-1)增至0.44 kg·(m~3·d)~(-1)时,总氮(TN)去除负荷也随之由0.09 kg·(m~3·d)~(-1)提高到0.42 kg·(m~3·d)~(-1),反应器污泥逐渐由浅红色加深,粒径大于0.2 mm的污泥所占比例由10.90%增至38.37%.采用高通量测序对接种污泥和负荷提高期的污泥进行检测,其中绿曲挠菌门(Chloroflexi)、变形菌门(Proteobacteria)、WWE3门、放线菌门(Actinobacteria)、浮霉菌门(Planctomycetes)等占据主导.随着厌氧氨氧化菌富集程度的增大,脱氮功能菌中的变形菌门所占比例逐渐减少,从21.60%降至14.20%,而浮霉菌门随之增多,相对丰度由0.73%升至15.50%.当反应器的容积负荷增到0.44 kg·(m~3·d)~(-1)时,浮霉菌门中,Candidatus Brocadia属、Candidatus Jettenia属和Candidatus Kuenenia属是主要菌属,Candidatus Brocadia属占13.40%,是主要的厌氧氨氧化菌属.

Start-up and Characteristics of the Microbial Community Structure of ANAMMOX

An anaerobic ammonium oxidation (ANAMMOX) reactor was successfully started up in 17 days, with the up-flow anaerobic sludge blanket (UASB) reactor being seeded with mixed anaerobic sludge from laboratory cultures with an ANAMMOX function and aerobic activated sludge from a municipal sewage treatment plant in a volume ratio of 1:2. The processes could be divided into two phases of hydrolysis, enhanced and steady. Anaerobic ammonium oxidation bacteria (AAOB) were enriched by improving the reactor volume load gradually after the steady phase. When the volume load increased from 0.10 kg·(m³·d)^-1 to 0.44 kg·(m³·d)^-1, the removal of total nitrogen (TN) also increased from 0.09 kg·(m³·d)^-1 to 0.42 kg·(m³·d)^-1. The color of the sludge changed from a light red that deepened gradually in the UASB reactor. At that time, the proportion of the sludge particle size greater than 0.2 mm increased from 10.90% to 38.37%.The sludges from the inoculation phase and from the phase when the volume load was increasing were analyzed by high-throughput sequencing, indicating that Chloroflexi, Proteobacteria, WWE3, Actinobacteria, Planctomycetes, and so on were the dominant species. The proportion of Proteobacteriain the denitrification bacteria was gradually reduced from 21.60% to 14.20% with an increase in the degree of AAOB enrichment, while the Planctomycetes increased from 0.73% to 15.50%. Candidatus Brocadia, Candidatus Jettenia, and Candidatus Kuenenia were the main species of Planctomyceteswhen the volume load increased to 0.44 kg·(m³·d)^-1 in the reactor, and the Candidatus Brocadia was the main species of AAOB, which accounted for 13.40%.