Experimental study on treatment of vegetable oil wastewater by inorganic ceramic membranes

The vegetable oil processing plants and catering trade often produce a large amount of wastewater, polluting the environment badly. The vegetable oil wastewater was treated by inorganic ceramic membranes. The effects of membrane material and pore size, character of wastewater, operational parameters on the separation behaviors were investigated. The experimental results show that the zirconia membrane with pore size of 0.2 μm has best performance. The steady flux obviously decreases either under high oil mass concentration or under high salt concentration. At the transmembrane pressure of 0.15 MPa, cross-flow velocity of 4 m/s and the temperature of 30°C, the steady flux can reach 150 L/(m² · h); the oil rejection rate achieves more than 98% under all experimental conditions.