将化学混凝方法与陶瓷膜微滤技术相结合,对汽车厂阴极电泳漆废水进行了治理。以石灰乳、聚丙烯酰胺(PAM)作絮凝剂,pH值为6.7时,混凝过程对COD去除率的贡献约63%,之后的微滤使废水中COD的去除率增加到85%。在流速为4.2m/s,跨膜压差0.10MPa,温度30℃时,膜稳定通量约250L/(m^2·h)。处理后出水可作为涂装车问循环冲洗水用;对COD〈700mg/L的废水,处理后出水可以直接排放。研究表明混凝前处理过程有助于提高膜的渗透速率,降低膜污染,改善出水水质。
A combination of coagulation and microfiltration with zirconia membrane was developed to treat cathodic electrocoating wastewater. The removal of COD is 63% at pH of 6.7 and with lime as coagulant. After coagulation, the supematant was treated with microfiltration using zirconia membrane (mean pore size of 0.2 IZ m), and the removal of COD increases to 85%. At a cross flow velocity of4.2m/s, trans-membrane pressure of 0.10MPa, and the steady flux was about 250 L/m^·2h, the results of filtration tests showed that the membrane fouling decreased; the permeate flux increased and permeate quality was improved with coagulation .The permeate obtained after coagulation and micro-filtration could be used as rinsing water in electrocoating process or discharge.