水动力条件对MBR中超滤膜不可逆污染的影响

Effect of hydrodynamic conditions on hydraulically irreversible fouling of UF membrane in MBR

为考察MBR处理微污染水过程中水动力条件对超滤膜水力不可逆污染的影响，介绍了水力不可逆膜污染的计算方法，探讨曝气、反冲洗、通量、水温等运行参数的影响并进行优化。结果表明：间歇曝气时，曝气时间、强度及反冲洗时间的选取需考虑MBR的净水效能，实验条件下，2 min的曝气时间是必需的，较优的曝气强度为30～36 m3／（ m2·h）；较长的反冲洗时间有利于控制膜的不可逆污染，反冲洗时间的确定尚需考虑超滤系统的产水率；过滤通量显著影响超滤膜的不可逆污染速率，PVDF、PVC膜的过滤通量分别不应高于31.5，14.0 L／（m2·h），长期运行中膜污染的评价尚需考虑温度的影响。

To investigate the effect of hydrodynamic conditions on hydraulically irreversible fouling of UF membrane in MBR for treating micro-polluted water, the method of determination of hydraulically irreversible fouling of UF membrane was introduced, and the effects of aeration, backwashing, flux and temperature on irreversible fouling were discussed. The results showed that the pollutant removal of MBR should be taken into account when selecting the time and flow of aeration. The duration of 2 min was necessary during intermittent aeration, with the optimal aeration intensity of 30-36 m3/（m2·h）. Prolonged backwashing duration was found to control the hydraulically irreversible fouling. The production of UF membrane in MBR should also be considered when determining the proper backwashing duration. The permeate fluxes influenced the hydraulically irreversible fouling rate significantly, and the values of PVDF and PVC membranes should be no more than 31.5 and 14.0 L/（m2·h） to maintain the long-term stable operation. Meanwhile, the impact of temperature on irreversible fouling should be considered.