膜生物反应器中膜的污染与清洗

Characteristic of membrane pollution and its cleaning in the membrane bioreactor process

通过不同清洗方法对膜通量恢复效果的评价以及对污染膜和各步清洗后对膜表面和断面形貌的观察,对膜生物反应器工艺中的膜污染特征和膜污染进行了研究。结果表明,清水冲洗能消除纤维膜之间淤积的污泥和膜表面松散的污染层,次氯酸钠可以清除膜表面的微生物和有机污染物,而硫酸和柠檬酸能清除膜上的无机物垢。在膜外表面的污染物主要为生物膜和凝胶层污染,而膜内表面的污染物主要为滋生的微生物和无机污染物。对应各步清洗后膜通量的恢复,可以推出,在试验的工艺条件下,无机物污染对膜过滤阻力的影响较大。在此基础上,为延缓膜污染对膜生物反应器提出三点建议。

By an evaluation of the recovery effect of the membrane flux with various cleaning method, the observ-ation of the surface and the section of the polluted membrane and the membrane after every step of cleaning, the characteristics of membrane pollution and its cleaning in the membrane bioreactor(MBR) process are studied. The results show clean water cleaning could remove the sludge filled among the membrane and the incompacted pollutants, while antiformine cleaning could remove most of the microorganism and organic pollutants of the membrane, and sulfuric acid and citric acid could remove the inorganic pollutants. The pollution on the outer surface of membrane is mainly formed by the microorganism and organic matter, while that on the inner surface, the pollution is mainly formed by inorganic matter and the growth of microorganism on membrane internal surface. It could also be concluded that the inorganic pollutant has a big contribution to the membrane filtrate resistant according to the recovery of the membrane flux. Based on this analysis, in order to lessen membrane pollution, three suggestions about MBR are put forward.