膜生物反应器系统中原生动物的群落特征

与常规生物处理工艺相比,膜生物反应器(MBR)系统由于污泥停留时间长、污泥浓度高等特点,因此反应器内微生物种群结构呈现不同的特点.通过对MBR系统中原生动物的群落结构进行为期近2年连续的监测结果表明,过长的污泥龄对系统中原生动物的种类与数量均有负面的影响.研究发现:①在长期不排泥的MBR系统中,当环境温度从11℃上升到25℃,原生动物的多样性呈显著上升趋势;②当污泥龄从350 d下降到30 d,MBR系统中原生动物的种类与数量明显增加.特别在较低的环境温度条件下,系统中原生动物的种类与数量随着污泥龄的缩短呈显著的上升趋势;③与相同污泥龄(SRT=30d)的氧化沟(TOD)系统相比,MBR的污泥中原生动物的种类与数量均低于TOD.

Protozoan Community Diversity in Membrane Bioreactor

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.