Protozoan Community Diversity in Membrane Bioreactor
膜生物反应器系统中原生动物的群落特征

Continuous monitoring on the microbial character was performed in the sludge in MBR compared with traditional active sludge process. It was found that the sludge retention time (SRT) and temperature were the dominant factors that control protozoan diversity. The extra-long SRT exhibited a negative effect on the activity of protozoa. When SRT decreased from 350 d to 30 d, protozoan diversity increased significantly. Subsequently, the structure of protozoa community in the MBR was found to be quite sensitive to environment temperature, and protozoan diversity continuously increased with the increasing temperature from 11 to 25℃ . The dominant population was alternate and in some order: running Ciliata , Epistylis and Opercularia, Rotifers , then Aeolosomatidae . Further analysis showed that MBR reactor harbored a lower detectable microbial diversity compared with the TOD reactor at the same temperature and SRT.