A／O-膜生物反应器和A^2O系统中有机物分子量分布的对比研究

Comparison of A/O-MBR and A^2O process through molecular weight distribution of organic matters

采用凝胶过滤色谱(GPC)对A/O-膜生物反应器(A/O-MBR)和A2O系统中有机物分子量分布进行了对比研究。结果表明,A/O-MBR系统中由进水到好氧滤液的有机物分子量分布依次变宽,其趋势恰好与A2O系统相反;A/O-MBR好氧滤液的有机物分子量分布远宽于A2O好氧滤液。A/O-MBR好氧滤液中重均分子量(Mw)>107u的有机物占总有机物质量的3.4%,表明正是由于膜的截留作用导致这类大分子有机物在MBR中的累积,而无法像A2O系统一样随出水流走;A/O-MBR系统各段污泥混合液的胞外聚合物(EPS)的分子量分布较分散,说明A/O-MBR系统中微生物新陈代谢产物多,并在膜的截留作用下最终造成了这些产物在膜表面大量的沉积。

A comparison between anoxie/aerobie membrane bioreactor （A/O-MBR） and anaerobic/anoxic/aerobic activated sludge process （A^2O） was carried out through distributions of molecular weight of organic matters. The results showed that the molecular weight distribution of A/O-MBR became wider following the procedure of the process and was contrary to that of A^2O. Although the molecular weight distribution of filtrate of A/O MBR aerobic tank was much wider than that of filtrate of A^2O aerobic tank, the effluent of A/O-MBR was not influenced because of the filtration function of the membrane. The molecular weight distribution of A/O-MBR EPS was much wider than that of A^2O EPS. These organics accumulated in the MBR because of filtration function of the membrane, so the or ganics with Mw more than 10^7 u took up 55.8% of the total membrane foulants.