[Effect of coagulation on the performance of microfiltration in treating phosphorus-containing wastewater].

Treatment of high-concentration phosphorus-containing wastewater produced from automobile painting-industry using microfiltration with and without coagulation pretreatment was studied.The results show that the membrane fouling decreased by reducing the extent of pore plugging and improving the shape of cake layer formed on membrane surface and the permeate flux increased with coagulation as pretreatment.In comparison with direct microfiltration(without coagulation),pretreatment with lime improves removal of phosphate from 11.0% to 99.7%.The permeate obtained from coagulation and microfiltration can meet the national discharge standard and be reused under very safe conditions.With the same cleaning method,the recovery of permeate flux is approximately 18% greater than that of without coagulation pretreatment,which may be due to the differences in the shape of deposited cake and the extent of irreversible fouling.