A^(2)O-IFAS工艺生物膜微生物群落的演替及分布特性

The colonization,succession and distribution characteristics of microbial community in biofilm of the mainstream A^(2)O process

在A^(2)O-IFAS工艺中探究了不同功能分区生物膜微生物群落的演替及分布特性.利用该工艺处理实际生活污水,总无机氮去除负荷可达(0.10±0.03)kg·m^(-3)·d^(-1),总无机氮和COD的平均去除率分别为70%和79%.高通量测序结果显示,厌氧氨氧化菌Candidatus_Brocadia在好氧区生物膜中的相对丰度最高(0.43%),其次是缺氧区生物膜、活性污泥和厌氧区生物膜.此外,絮体污泥与好氧区生物膜有着相似的微生物群落,该结果表明,功能区非生物因素可驱使生物膜微生物群落在缺氧区和厌氧区发生演替现象,DO、C/N比等环境因素和微生物的互作机制是驱动微生物群落分布和厌氧氨氧化菌富集的关键.本研究可为主流厌氧氨氧化菌的富集和技术应用提供重要参考.

In this study,the succession and distribution of biofilm microbial communities in different functional zones of an A^(2)O-IFAS reactor was explored.The IFAS reactor was used to treat real domestic wastewater and the total inorganic nitrogen removal loading rate reached(0.10±0.03)kg·m^(-3)·d^(-1).The removal efficiencies of total inorganic nitrogen and COD were 70% and 79%,respectively.The high-throughput sequencing results revealed that aerobic biofilm maintained the highest relative abundance of Candidatus_Brocadia,followed by oxic biofilm,activated sludge and anerobic biofilm.Further analysis suggested that the microbial community of the activated sludge was more similar to aerobic biofilm.Besides,nonbiological factors in functional zones drove the succession of microbial community in anoxic and anaerobic biofilm.The distribution of microbial community as well as the enrichment of anammox bacteria was also driven and determined by DO,C/N ratio and other key environmental factors,together with the interaction mechanisms of microorganisms.This study provides an important reference for the enrichment of anammox bacteria and technical application of mainstream anammox.