膜生物反应器长期运行条件下膜的清洗方法及机理研究

对实际工程中运行2年以上的MBR的膜使用能谱分析、傅立叶红外光谱和接触角测定等方法对膜表面的污染物特性进行了分析,对膜清洗过程中不同清洗剂的作用效果进行了探讨,并进一步对膜污染过程进行了推测.结果表明,酸性清洗剂对膜的清洗效果较好,膜表面无机污染基本被去除,但不能完全有效去除膜表面有机酸、蛋白质、多糖和多糖类物质等有机污染物;NaOH和NaClO对污染后的膜的清洗效果不佳,原因可能是由于MBR进水为混凝沉淀池出水,长期运行条件下膜污染以无机污染为主,有机污染可能起到了螯合的作用,使无机污染物和有机污染物络合,增加了碱和氧化剂去除有机污染的难度.

Cleaning method and mechanism of a submerged membrane bioreactor for a long-term operation

In order to investigate the fouling reasons and cleaning methods of a submerged membrane bioreactor for more than 2 years operation, SEM-EDS, FTIR and contact angle system, were applied to analyze the membrane fouling layer. The cleaning effects of membrane by different cleaning methods were studied and the fouling process was also suggested. The result showed that the cleaning effects of membrane by acid cleaning were good and acid cleaning could remove most of inorganic foulants, but could not effectively remove organic foulants such as organic acid, protein and polysaccharide. While, the cleaning effects of membrane by NaOH and NaClO were not very good because the influent of MBR was effluent of coagulation-sedimentation tanks. With membrane running lastingly, the membrane foulants were almost inorganic foulants, and inorganic and organic foulants were complex by the chelate effect of organic foulants, so it was very difficult for alkali and oxidant to remove organic foulants.