MBR污水处理工艺长期运行中的膜强化清洗方式

Enhanced Membrane Cleaning Method of MBR Wastewater Treatment Process during Long-Term Operation

基于上海城镇污水处理厂AAO-MBR膜工艺长期运行中膜不可逆污染严重、离线化学清洗难以恢复理想通量的问题,对其清洗方式进行改进。在原清洗方式的基础上增加草酸二次清洗,探究污染膜产水能力恢复情况,并通过中试试验进行验证。结果表明:膜清洗方式改进后,离线清洗对膜污染物的去除更加彻底,清水通量可恢复至新膜的95.1%,较原清洗方式提高了27.2%。在相同通量下中试运行24 d后,膜运行压力比原清洗方式低18.2 kPa,膜污染速率明显减慢。研究通过改进MBR长期运行平板膜的污染物清洗方法,为今后MBR污水厂膜清洗提供参考,具有较好的工程指导意义。

In order to remove the irreversible membrane fouling during the long-term operation of an anaerobic-anoxic-oxic membrane bioreactor in a municipal wastewater treatment plant(WWTP)in Shanghai,a modified membrane backwashing method was proposed in this study.Twice cleaning of oxalic acid was added on the basis of original cleaning method.The recovery performance of fouled membrane was discussed in detail and verified by the pilot scale experiment.Results showed that the modified membrane cleaning method could remove more membrane foulants,and the water flux could be restored to 95.1%that of the fresh membrane,which was 27.2%higher than the original cleaning method.After 24 days of pilot operation under the same flux,the transmembrane pressure was 18.2 kPa lower than that of original cleaning method,indicating the membrane fouling was significantly mitigated.This study provides reference for the enhanced membrane cleaning of long-term operation MBR WWTP,which has better significance for engineering guidance.