MBR中厌氧氨氧化菌群落结构及膜污染性能研究

Microbial Community Composition and Membrane Fouling Performance of Anaerobic Ammonia Oxidation Membrane Bioreactor

采用浸没式厌氧氨氧化膜生物反应器(Amx IMBR)培养厌氧氨氧化菌,当进水氨氮与亚硝态氮浓度均为450 mg/L、氮负荷为0.6 kg/(m^(3)·d)时,总氮去除率稳定在86%左右,氨氮、亚硝态氮去除率分别稳定在90%、97%以上;氨氮去除量∶亚硝态氮去除量∶硝态氮生成量基本为1∶1∶0.18。Amx IMBR的临界通量为8.63 L/(m^(2)·h),这与长期运行的结果相符。膜污染的来源主要是紧密型胞外聚合物,其中蛋白质和多糖含量分别为2.42、0.84 g/m^(2)。运行过程中,厌氧氨氧化菌形态从红棕色颗粒污泥变成了浮游态污泥,是Amx IMBR最显著的特征之一。高通量分析结果显示,浮游态污泥中的优势菌群主要为拟杆菌门(Bacteroidetes,47.83%)、浮霉菌门(Planctomycetes,21.2%)、变形菌门(Proteobacteria,18.85%),其中优势厌氧氨氧化菌属为Candidatus Kuenenia,相对丰度为17.08%。

Anammox bacteria were cultured in an immersed anaerobic ammonia oxidation membrane bioreactor(Amx IMBR).When NH_(4)^(+)-N and NO_(2)^(-)-N in the influent were both 450 mg/L and nitrogen loading rate was 0.6 kg/(m^(3)·d),the removal rates of TN,NH_(4)^(+)-N and NO_(2)^(-)-N stably reached 86%,above 90%and 97%,respectively.In addition,the ratio ofΔNH_(4)^(+)-N,ΔNO_(2)^(-)-N andΔNO_(3)^(-)-N was basically 1∶1∶0.18.Critical flux of the Amx IMBR was 8.63 L/(m^(2)·h),which was consistent with the long-term operational results.Tightly bound extracellular polymeric substances were the key factors to membrane fouling,in which the content of protein and polysaccharide were 2.42 g/m^(2) and 0.84 g/m^(2),respectively.During the operation,morphology of the Anammox bacteria changed from red granular sludge to planktonic sludge,which was one of the most significant characteristics of the Amx IMBR.High-throughput sequencing results indicated that the dominant microbial species of the Amx IMBR were Bacteroidetes(47.83%),Planctomycetes(21.2%)and Proteobacteria(18.85%).Among them,the dominant Anammox functional bacterium was Candidatus Kuenenia with relative abundance of 17.08%.