不同运行模式序批式膜生物反应器中污泥特性研究

比较了不同运行模式(AO、AOA及A 2O)对序批式膜生物反应器(SBMBR)污泥特性的影响.结果表明:运行模式对污泥粒径存在明显的影响,曝气时间较长的AO MBR及厌氧末引入缺氧段的A 2O MBR,有助于形成紧密而细小的颗粒.而粒径大且结构松散的污泥耗氧速率较高;充分的好氧时间则有利于耗氧速率的提高.好氧吸磷速率受运行方式影响,且与耗氧速率呈正相关性.适宜的厌氧阶段时长有助于提高污泥厌氧释磷能力;缺氧段及其位置的设置对反硝化除磷菌的选择与富集影响较大.本试验中A 2O MBR中反硝化聚磷菌(DPAOs)比例为40.6%,分别比AO及AOA MBR中提高了0.57和0.34倍.膜反应器中膜污染主要由膜表面滤饼层导致.曝气时间只是控制膜污染的因素之一,膜污染随污泥平均粒径的减小而加重,运行方式对膜污染也起着不可忽视的作用.

Sludge characteristics of sequencing batch membrane bioreactors operated in different modes

The sludge characteristics of sequencing batch membrane bioreactor(SBMBR) were studied in three different operation modes (AO,anaerobic/aerobic; AOA,anaerobic/aerobic/anoxic and A 2O, anaerobic/anoxic/aerobic mode). The results show that operation mode has an obviously effect on particle size. It is beneficial to forming tighter and smaller particle size in AO MBR with longer aeration time and A 2O MBR with anoxic phase introduced at the end of anaerobic stage. Higher specific oxygen uptake rate (\%R\% sou ) can be observed for sludge with larger particle size and loose structure. Longer aeration time is also beneficial to improving the value of \%R\% sou . A suitable length of anaeration time will help to improve the release phosphorus ability of the sludge during anaerobic zone. The choice and enrichment of denitrifying phosphorus accumulating organisms (DPAOs) was greatly influenced by anoxic stage and its location set. In this study, the DPAOs ratio in A 2O MBR is 40.6% which is 0.57 and 0.34 times higher than that in AO and AOA MBR, respectively. Membrane fouling is mainly caused by the surface layer cake. Aeration time, sludge particle size and operation mode all play an unignored role for membrance fouling.