Treating oily wastewater in oil field by walnut shell filter - Ultrafiltration

Walnut shell filter and ultrafiltration equipment were used to eliminate the suspended solid, suspended particles and oil in the oily wastewater. The performance of the walnut shell filter and ultrafiltration equipment to eliminate oil and turbidity was studied, changes of flux of ultrafiltration equipment and the method for cleaning the membrane were also investigated. The results show that the mass concentration of oil in treated water is reduced from 115.70 to 0.33 mg/L, the amount of suspended particles (≤ 1.0 μrn) is decreased from 1 545 686 individuals per milliliter to 13624 individuals per milliliter, the average removal rate of particles (≤ 1.0 μm) reachs to 99.09%, the mass concentration of suspended solid is dropped from 18.06 to 0.56 mg/L, the coefficient of membrane is increased from 3.16 to 28.61. And the quality of water which was treated by this combination process can meet the Al quality standards of recommended indexes in SY/T5329-94 about the injection water quality for clastic rock oil fields.