曝气对膜生物反应器中膜污染的影响

Effects of Aeration on Membrane Fouling in Membrane Bio-reactor System

膜污染是制约膜生物反应器广泛应用的主要因素,而曝气过程又作为膜污染控制主要的手段而被普遍使用。曝气过程对膜污染的影响可以分为直接影响和间接影响2方面,直接影响主要为改变膜表面的流体动力学环境,增加膜表面的流体剪切力,以减少和去除膜污染物的附着;间接影响主要为改变反应器中混合液的特性,从而优化或劣化膜过滤的环境条件。通过控制曝气过程中的关键要素,可以有效减缓膜污染,促进膜生物反应器在更多领域的应用。

Membrane fouling is one of the main restriction factors to limit the broad applicationof membrane bio-reactor, while aeration is also used to control membrane fouling in almost all cases. The effects of aeration on membrane fouling could be divided into two types, the direct ones and the indirect ones. The direct ones indicated that aeration can change the hydrodynamic conditions on membrane surface, increase shear stress and remove fouling substances. In comparison, the indirect ones could affect the characteristics of mixed liquor then make filtration better or worse. To mitigate membrane fouling effectively, the key factors of aeration should be concentrated and make MBR wide-spreading in other fields.