纯膜MBBR工艺处理微污染水的工程启动研究

Start?up of Pure MBBR Process for Micro?polluted Water Treatment

采用两级纯膜MBBR工艺处理低基质河道水,研究了启动过程中生物膜的硝化性能,并同步分析了生物膜厚度、生物量及微生物种群变化情况。结果显示,在冬季最不利水温条件下不接种污泥直接原水启动,经过10 d系统调试成功,出水氨氮稳定达标,一、二级MBBR区出水氨氮分别为(1.35±0.38)、(0.43±0.15)mg/L,硝化负荷分别为(0.182±0.026)、(0.066±0.020)kg/(m3·d),系统氨氮去除率达到(88.98±3.03)%,同时,系统具有一定的COD去除能力;启动过程中,负荷增长至第14天达到稳定,生物膜的生物量于第28天达到稳定,一、二级MBBR区的生物量分别为(2.66±0.36)、(2.14±0.19)g/m2,生物膜厚度分别达到(197±23)、(157±17)μm;生物膜负荷具有一定余量,能够抵抗进水负荷冲击。启动阶段,生物膜物种丰富度于第21天基本达到稳定,一级生物膜的物种丰富度、物种分布均匀程度高于二级生物膜,具有更高的物种多样性;生物膜中优势微生物主要有Nitrospira、Hyphomicrobium、Nitrosomonas、Kouleothrix、Pedomicrobium、Pedobacter等,其中硝化菌属Nitrospira在一、二级生物膜中的相对丰度分别达到8.48%~13.60%、6.48%~9.27%,Nitrosomonas的相对丰度分别达到2.89%~5.64%、0.00%~3.48%,而Hyphomicrobium和Pedomicrobium等菌属的存在可能与进水中芳香烃类DOM的转化有关。

A two-stage pure MBBR was applied to treat micro-polluted river water.The nitrification performance of biofilm during start-up was investigated,and the changes in biofilm thickness,biomass and microbial community were analyzed simultaneously.The reactor was directly started at extremely low temperature in winter by feeding raw water without sludge inoculation,and the ammonia nitrogen in effluent reached the standard stably after 10 days of system debugging.The ammonia nitrogen concentrations in the effluent of the first and second stage MBBR were(1.35±0.38)mg/L and(0.43±0.15)mg/L,and the nitrification loads of the first and second stage MBBR were(0.182±0.026)kg/(m3·d)and(0.066±0.020)kg/(m3·d),respectively.The ammonia nitrogen removal efficiency of the system reached(88.98±3.03)%.At the same time,the system had a certain COD removal capacity.During the start-up process,the nitrification load increased and reached stability on day 14,and the biomass of the biofilm tended to be stable on day 28.The biomass of the first and second stage MBBR was(2.66±0.36)g/m2and(2.14±0.19)g/m2,respectively,and the thickness of the biofilm reached(197±23)μm and(157±17)μm,respectively.The biofilm load had a certain redundancy and could resist the impact of the influent load.The species richness of biofilm basically stabilized on day 21,and the species richness and distribution uniformity of the first stage biofilm were higher than those of the second stage biofilm,indicating that the former had higher species diversity.The dominant bacterial genera of the biofilm were Nitrospira,Hypomicrobium,Nitrosomonas,Kouleothrix,Pedomicrobium,Pedobacter,etc.Among them,the relative abundance of Nitrospira in the biofilm from the first and second stage MBBR was 8.48%-13.60%and6.48%-9.27%,respectively,and the relative abundance of Nitrosomonas was 2.89%-5.64%,0.00%-3.48%,respectively.The presence of bacterial genera such as Hyphomicrobium and Pedomicrobium might be related to the transformation of aromatic hydrocarbon DOM in the influent.