Application of Enhanced Coagulation Aided by UF Membrane for Car Wash Wastewater Treatment

The effect and the application ways of enhanced coagulation using KMnO₄ were tested in this article. It was demonstrated that the addition of KMnO₄ to coagulant (PAC) could enhance the efficiency of coagulation, which helped for reducing clogging of ultrafiltration membrane. KMnO₄ is suitable to be used before PAC addition for avoiding large flocculating constituent conforming, which reduces contacting area of KMnO₄ and organic matters. Furthermore, it´s would not oxidize the conformed flocculating constituent and destroy the flocculating. The existence of organic matter could influence the effect of enhanced coagulation on wastewater treatment. Mechanisms that the good effect of enhanced coagulation were analyzed. Four kinds of membrane resistance were tested, which illustrated that the adsorption resistance was the main factor for membrane blocking. Adsorption resistance normally was caused by organic matters. Existence of KMnO₄ would reduce the influence of organic matter on coagulation and two reasons were analyzed. By treating in this way, treated water could be reused for car washing.