重力驱动式动态膜生物反应器的膜清洗再生方式优化研究

Optimization of Membrane Cleaning Strategies for Stable Operation of A Gravity-Driven Aerobic Dynamic Membrane Bioreactor

构建了重力驱动式好氧动态膜生物反应器(DMBR)处理生活污水,比较不同物理清洗方法(空气反冲洗、表面刷洗和组合方式)对动态膜再生的影响,探究了动态膜的形成过程和过滤机理,解析DMBR的污染物去除性能。研究结果表明,动态膜的形成伴随着出水颗粒物粒径的不断减少,5 min后颗粒粒径分布基本稳定,动态膜形成阶段符合滤饼过滤模型,稳定运行阶段符合标准过滤模型。DMBR对浊度、NH_(4)^(+)-N、COD和SCOD的平均去除率分别为99.6%、94.0%、93.2%和82.8%。空气反冲洗辅助刷洗不仅可以去除微网表面的污染层,还可去除对DMBR长期运行有影响的污染物,五个过滤周期的初始通量恢复率均达到93.1%以上。

A gravity-driven aerobic dynamic membrane bioreactor(DMBR)was constructed for the treatment of domestic wastewater.The effects of different physical cleaning methods(air backwashing,surface brushing and combination methods)on the regeneration of dynamic membranes were compared,the formation process and filtration mechanism of dynamic membranes were investigated.The pollutant removal performance of DMBR was analyzed.The results showed that the formation of the dynamic membrane was accompanied by the decreasing particle size of effluent particles,and the particle size distribution was stable after 5 min.The dynamic membrane formation stage followed the filter cake filtration model,and the stable operation stage followed the standard filtration model.The average removal rates of turbidity,NH_(4)^(+)-N,COD and SCOD by the DMBR were 99.6%,94.0%,93.2%and 82.8%,respectively.The air backwash-assisted washing not only removed the contaminated layer on the surface of the micro-mesh but also removed the particulate matter that is potentially contaminating the DMBR during the long-term operation.The initial flux recovery rate can be more than 93.1%after the five filtration cycles.