Application of Internal Circulation (IC) and Two-Step Biochemical Process for Oil Wastewater Treatment

In expectation to improve the properties of production wastewater with both complicated composition and high amount of organic compounds produced by oil and grease processing enterprise, pretreatment, IC anaerobic technology and the two stage biological contact oxidation technology were combined to process the oil wastewater. It was found that the removal rate of COD, oil and ammonia nitrogen could be enhanced to 99.71%, 99.8%, 85.8%, respectively when the concentration of influent COD, grease and ammonia nitrogen were 32500mg/L, 2800mg/L and 95 mg/L. Besides, the effluent quality could keep stable, coming up to the primary standard of the integrated wastewater discharge standard (GB8978-1996). Meanwhile, biogas, a kind of clean secondary energy, was also produced during the treatment process and could be applied in both power generation and steam production, exhibiting excellent technicality and economic.