MBBR泥膜复合系统泥膜竞争关系的影响因素

为探究MBBR泥膜复合硝化系统内泥膜竞争关系,通过小试试验研究了水处理过程中常规因素（污泥浓度、DO、温度、C/N）对MBBR泥膜复合系统硝化效果的影响,分析了系统内污泥容积负荷和移动床生物膜反应器（MBBR,Moving-Bed Biofilm Reactor）生物膜容积负荷变化趋势,进而得出泥膜竞争规律.结果表明,MBBR泥膜复合系统容积负荷均大于单一污泥或MBBR生物膜系统的容积负荷.在一定范围内,污泥浓度、DO、温度与MBBR泥膜复合系统容积负荷呈现正相关,且系统内活性污泥在与MBBR生物膜在竞争DO和基质时优势明显,而MBBR生物膜则具有更强的耐低温能力.进水C/N与MBBR泥膜复合系统硝化负荷呈负相关,且活性污泥在应对进水C/N过高时较MBBR生物膜更具优势,MBBR的“镶嵌”则强化了系统SND效果.微生物群落变化显示MBBR泥膜复合系统内的硝化细菌优势菌属为Nitrospira,且悬浮载体生物膜对其富集能力明显高于活性污泥.

Factors influencing the competition between activated sludge and biofilm in hybrid MBBR nitrification system

In order to explore the competition relationship between activated sludge and biofilm in hybrid MBBRnitrification system, the influence of conventional factors (sludge concentration, DO, temperature, C/N) on the nitrification effect of hybrid MBBR system was studied through lab-scale experiment. The changing trend of sludge volume load and MBBR (moving bed biofilm reactor) biofilm volume load in the system was analyzed, and the competition relationship of sludge membrane was obtained. The sludge concentration, DO and temperature were positively related to the volume load of hybrid MBBR nitrification system in a certain range. In addition, compared with MBBR biofilm, the activated sludge in the system has an obvious advantage in competing for DO and substrate, while MBBR biofilm had a stronger ability of low temperature resistance. The influent C/N was negatively correlated with the nitrification load of hybrid MBBR system, and the activated sludge had more advantages than MBBR biofilm in response to the high influent C/N, and MBBR "inlay" enhanced the SND effect of the system. The results of microbial analysis showed that Nitrospira was the dominant nitrifying bacteria in hybrid MBBR system, and the enrichment capacity of suspension carrier biofilm was significantly higher than that of activated sludge.