浸没式PAC-AMBRs系统中PAC缓解膜污染的研究进展

浸没式粉末活性炭-好氧膜生物反应器(powdered activated carbon-aerobic membrane bioreactors,PAC-AMBRs)是一种利用PAC吸附性、微生物降解性和膜分离特性的新型废水处理技术。本文重点分析了近20年来浸没式PAC-AMBRs系统直接投加PAC缓解膜污染机制的研究成果,探讨了PAC通过对污泥絮体和溶解性有机物的综合影响缓解膜污染的机制,分析了PAC投加量和补充率对膜污染的影响。通过分析可知PAC缓解膜污染是一个综合作用的结果。以PAC为载体形成的污泥絮体在膜表面形成结构疏松和抗压性强的滤饼层,不仅能有效降低滤饼层阻力(cake resistance,R_c),还可以作为自成型动态膜截留溶解性有机物和悬浮微生物等来减少此类污染物造成的膜污染。PAC通过吸附和/或表面附着的微生物降解溶解性有机物的协同作用降低其造成的过滤阻力。定期排出和补充一定量的PAC可以提高缓解膜污染的效率。

Research status of membrane fouling mitigation by PAC in submerged PAC-AMBRs

The submerged powdered activated carbon-aerobic membrane bioreactors (PAC-AMBRs) are new wastewater treatment technology, which integrates PAC adsorption, microbial degradation, and membrane separation. This review focuses on the previously published research on the mechanism of directly adding PAC to the submerged PAC-AMBRs system to alleviate membrane fouling in the past 20 years. The membrane fouling mitigation mechanism of sludge flocs and dissolved organic matters by PAC is analyzed comprehensively. The effects of PAC dosage and replenishment rate on membrane fouling are discussed. It is concluded that the fouling mitigation by PAC is a comprehensive process. The cake layer formed by sludge flocs with PAC as a carrier had a loose structure and strong pressure resistance. It not only effectively reduces the cake resistance but also is used as a self-forming dynamic membrane, intercepting dissolves organic matter and suspends microorganisms and reducing membrane fouling. Dissolved organic matter is removed through the synergistic effect of PAC adsorption and/or microbial degradation on PAC, reducing membrane fouling and improving permeate flux. Regular discharge and supplement of a certain amount of PAC can improve the efficiency of fouling alleviation.