常温厌氧MBR中微生物群落结构与膜污染研究

为考察微生物群落结构与膜污染的关系,在常温下运行厌氧膜生物反应器,并应用末端限制性片段长度多态性分析(T-RFLP)技术,对膜丝表面微生物群落结构变化进行了研究,同时考察了微生物群落结构变化与反应器中溶解性微生物产物(SMP)、胞外聚合物(EPS)的关系.结果表明:在常温状态下膜污染周期约为18d,CODCr的去除率约为93%,运行效果稳定;微生物代谢产物的浓度随着微生物种群的演替呈逐渐升高的趋势,加速了膜污染进程;膜压(pTM)处于缓慢上升期时,膜丝表面微生物优势菌群为Raoultella、Owenweeksia hongkongensis,膜压(pTM)处于稳定上升期时,膜丝表面的优势菌群演替为 Delftia acidovorans、Halothiobacillus neapolitanus,最后当膜压(pTM)处于快速上升期时,bp78的微生物成为了膜丝表面的顶级群落.膜压(pTM)处于缓慢上升期和稳定上升期时,膜压(pTM)与微生物群落结构的多样性呈显著正相关;膜污染进入快速上升期时,膜丝表面出现了顶级群落,此时微生物群落多样性明显降低且与膜压升高呈弱相关;膜丝表面微生物群落均匀度随着膜压(pTM)的升高呈现出先增高后降低的趋势,膜丝表面微生物群落经历了不断附着,相互竞争至顶级群落出现的演替过程.

The relationship between microbial community structure and anaerobic MBR membrane fouling at a room temperature

An anaerobic membrane bioreactor was run at a room temperature to investigate the relationship between microbial community structure and membrane fouling. Changes in the microbial community structure of membrane surfaces were studied by terminal restriction fragment length polymorphism analysis (T-RFLP) technology. The relationship between the microbial community structure and soluble microbial products (SMP), extracellular polymeric substances (EPS) were also investigated. Membrane fouling period was 18d at a room temperature, and the removal rate of CODCr was approximately 93%. The succession of microbial populations made the concentration of microbial metabolites gradually increased and accelerated the process of membrane fouling. The dominant microbial species of membrane surface were Raoultella, Owenweeksia hongkongensis when film pressure was slowly rising. When the pressure rose steadily, the dominant bacteria changed into Delftia acidovorans, Halothiobacillus neapolitanus. At last, the microbe of bp78 become the climax community. When the membrane fouling is through the slow rising period and steady rising period, the pressure (pTM) and the diversity of microbial community structure showed a significant positive correlation. When membrane fouling was in the rapid rising stage, top community appeared on the surface of the membrane silk, and microbial community diversity decreased significantly. At this point, the diversity of microbial community structure showed weakly related with the membrane pressure. The evenness of microbial community on membrane surface increased firstly and then decreased as membrane pressure rose, and the microbe continued to adhere on the membrane surface firstly, and then competed with each other until the top community appeared.