臭氧对膜法水处理中膜污染的影响

Effect of Ozone on Membrane Fouling in Water and Wastewater Treatment:a Research Review

膜过滤是一种高效水处理技术,包括污水处理中的膜-生物反应器(membrane bioreactor,MBR)和针对二级生物处理出水(生产再生水)、地表水(生产饮用水)的膜过滤工艺等,其中膜污染是制约膜工艺应用的一个主要问题.臭氧具有强氧化性,在水处理上得到了广泛的应用.近十几年来,针对臭氧-膜过滤组合工艺的研究正变得越来越多,因此本文对这些研究进行了系统综述与分析.在MBR组合臭氧控制膜污染方面的研究中,目前结论相对较少.可以通过对MBR进水预臭氧化或者投加适量臭氧到MBR混合液这2种方式来减轻MBR膜污染.在针对微污染水的臭氧-膜过滤组合工艺中,根据臭氧的功能和结构形式主要分为3种,分别是污染膜臭氧清洗、分离式臭氧-膜工艺和一体式臭氧-膜工艺.绝大部分报道认为臭氧可以有效地控制膜污染的发展,但也有少数投加臭氧后膜污染加剧的情况.目前,臭氧化影响膜污染机制的研究主要集中在有机物方面,根据原水水质和工艺结构参数等的不同,颗粒物、微生物和无机物质也在这个过程中起着相应的作用.另外,在迄今为止的研究中,还缺乏对于臭氧投加方式和分散方式的统一衡量和比较标准.作者建议应该加强对一体式臭氧-膜组合工艺的研究,并且要注意臭氧投加的工艺经济性.

As a high efficient water and wastewater treatment technology, membrane filtration has been mainly used in wastewater treatment as membrane bioreactor, in reclaiming secondary effluent, treating surface water and potable water, and etc. Membrane fouling is a main obstacle to the wide application of membrane technology. Ozone has strong oxidizing power and has been utilized widely in water and wastewatcr treatment. In recent years, researches on combined process of ozone-membrane filtration are increasing. This paper does reviews and analysis of these researches. It is noticed that there has been a few of researches on the ozone treatment plus MBR process. Pre-ozonation of feed to MBR and slight ozonation of the mixed liquid in MBR may be used to relieve membrane fouling. Combined processes of ozone-membrane filtration can be divided into three classes in terms of the function of ozone and the system configuration： ① cleaning the fouled membrane with ozone; ② separate ozone-membrane filtration process; ③ integrated ozone-membrane filtration process. Although most reports supported that ozonation can control membrane fouling development, there were contrary results. At present, researches on the mechanisms of ozone＇ s effect on membrane fouling control concentrated on the change of organic composition of the filtration inlluent under ozonation, however, particulate substances, microbial and inorganic substances may also be affected and then play roles in membrane fouling, depending on source water quality and process configuration. Moreover,there have not been common parameters to evaluate the ozone diffusion equipment and efficiency. The authors suggest that further researches should emphasize on integrated ozone-membrane process, and more attention should be paid to the cost-effectiveness of the combined process.