Treatment of phosphate-containing oily wastewater by coagulation and microfiltration.

The oily wastewater generated from pretreatment unit of electrocoating industry contains oils, phosphate, organic solvents, and surfactants. In order to improve the removal efficiencies of phosphate and oils, to mitigate the membrane fouling, coagulation for ceramic membrane microfiltration of oily wastewater was performed. The results of filtration tests show that the membrane fouling decreased and the permeate flux and quality increased with coagulation as pretreatment.

[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.