在线混凝-平板陶瓷膜过滤处理长江原水特性研究

Study on treatment of Yangtze River raw water using online coagulation-plate ceramic membrane filtration process

以在线混凝-平板陶瓷膜过滤工艺为研究对象,考察了向长江原水中投加不同混凝剂时膜污染的控制效果以及对出水水质的影响。结果表明,在膜通量为120 L/(h·m^2)工况下,在线混凝预处理可有效降低比跨膜压差的增量,与直接过滤相比,有机物的去除效果均能够提高2倍以上。从工艺的透过性和选择性考量,投加铝盐的处理效果均优于铁盐,这与泥饼层的形成过程及结构相关。混凝剂投加量对膜污染的影响程度较大,对有机物的去除效果影响较小。投加混凝剂可降低原水中富里酸、蛋白质类有机物含量,能够有效缓解膜污染。相同条件下,投加4 mg/L PAC的处理效果最佳。

Taking online coagulation-plate ceramic membrane filtration process as the research object,the effect of different coagulants on membrane fouling control of Yangtze River raw water as well as the effluent water quality were investigated.The results showed that,online coagulation pretreatment could effectively reduce the incremental quantity of the transmembrane pressure under membrane flux of 120 L/(h·m^2).Compared with direct filtration,the removal efficiency of organic matters could be increased by more than two times.Considering the permeability and selectivity of the combined process,the treatment effect by aluminium salt was better than that by iron salt,which was related to the formation process and structure of the sludge cake layer.Coagulant dosage had a greater impact on membrane fouling and a smaller impact on organic matters removal.Adding coagulant could reduce the content of fulvic acid and protein organic matters in raw water,which effectively alleviated the membrane fouling.Under the same condition,adding 4 mg/L PAC could get the best water treatment effect.