处理低温污水耐冷菌生物膜的研究

Biofilm characteristics of psychrotrophs for low-temperaturesewage treatment

寒冷地区冬季生活污水生物处理效率低，处理后污水排放经常出现不达标的问题．为了提高低温生活污水的生物处理效率，采用孔隙结构发达的软性聚氨酯泡沫为固定化载体，对活性污泥中分离得到的高效耐冷菌群进行固定化，并投加到生物反应器中运行．污水处理系统运行到30d左右时，化学需氧量（COD）的去除率达到82％，生化需氧量（BOD）的去除率达到92％．耐冷菌在载体的多孔结构中形成直径10-30μm的成团簇状分布的生物膜，每克载体附着生物量平均可达800mg左右，位于载体外层空间的生物膜量和生物活性明显高于内层．生物膜中耐冷细菌种群呈多样性分布，主要为各种耐冷球菌和杆菌，少量丝状菌起着生物膜骨架作用．低温生物膜的这些微生物结构为稳定系统、高效处理低温污水提供了基础．

It is always a problem to treat winter sewage effectively in cold area. In order to improve the treatment efficiency of low-temperature sewage, psychrotrophic bacteria isolated from activated sludge were applied to filling materials （Soft Polyurethane Foam） and added into the sewage treatment system. After 30 days＇ continuous running, the COD （Chemical Oxygen Demand） removal rate was improved to 82% and BOD （Biochemical Oxygen Demand） removal rate reached to 92%. Psychrotrophic bacteria initially attached to SPF gradually formed microbial communities sizing from 10 to 30μm, which unevenly distributed throughout the porous space of filling materials. There were around 800mg biomass per gram attached to the filling materials, the biofilms immobilized in outer layer were enriched and more active compared to those in inner layer. The microbial structure developed a heterogeneous colonization pattern mainly composed of cocci and bacilli, and a few filamentous microorganisms playing a skeletal role in the biofilm formation. The microbial characteristics of low-temperature biofilm observed above assured the sewage treatment running stably and efficiently.