Preparation of coal-based microfiltration carbon membrane and application in oily wastewater treatment

The coal-based microfiltration carbon membrane with low cost for the treatment of oily wastewater was prepared by carbonization of tubular carbonaceous precursor obtained by extrusion method. The pore size of carbon membrane was controlled by adjusting the particle size of coal. Effects of pore size of carbon membrane, transmembrane pressure and crossflow velocity on the filtration flux were investigated in the treatment of oily wastewater. The results indicate it is feasible to treat oily wastewater by coal-base microfiltration carbon membrane. The carbon membrane with pore size of 1.0 μm and the operation conditions of 0.10 MPa transmembrane pressure and 0.1 m/s crossflow velocity are recommended. After treated by coal-based microfiltration carbon membrane, the oil rejection coefficients of oily wastewater are up to 97%, and the oil concentrations of the permeate are less than 10 mg/L, which can meet the National Discharge Standard of China for wastewater.