Experimental study on car washing wastewater treatment by coagulation and nano filtration method

With the increase of car ownership in China, the number of car-wash has increased. This directly causes the increase of water consumption and vehicle washing wastewater. China is facing not only the shortage of water resources, but also the serious pollution of water resources. Therefore, the recovery and treatment of car washing wastewater is imminent. The existing handing) of wastewater include coagulation treatment, membrane biological reaction method, membrane filtration physical treatment and air float filtration method. In this research the coagulation treatment is used as the pre-treatment, the nano filtration membrane is used to treat the wastewater, and the concentrated water after nano filtration enters into the municipal sewage. Using this method, the removal rate of turbidity, COD and LAS reach the expected levels. The test shows that the car wash wastewater treated by our method has reached the discharge standard.