Study On Bio-Chemical Treatment Of Oily Wastewater Under High Salinity Conditions

With the industrial development in local petroleum, the rate of water, contained in oil-field produces, rises year by year. Parts of areas, oil-field produced water' quantity is much larger than it is need to reinject, so much so that oil-field produced waste water needs to be disposed before draining. The produced water in oil-field of high mineral in north-Shannxi is hard to dispose with high salinity. Therefore, the doable and economical biological treatment is full of significance in improving local environment.According to the characteristics of high-salinity oily waster water, the paper adopts Hydrolysis- Acidogenesis-Two Stage Biological Contact Oxidation and SBRprocess to treat the wastewater with systematic testing and theoretical analysis.Some conclusions are inferred from the experiments includes. Through hydrolysis- Acidogenesis, the ratio of BODs/CODcr increases from 0.49 to 0.54, and after remaining in HA reactor 8h and then in BCO reactor 6h, the removal rate of CODcr is up to 84.5% and that of oil is 88.4% . The optimum operating procedures of SBR are: filling(unlimited aeration) 1h, aeration 10h, setting 1h, instantaneously draining, standing-by ,lh. The optimum treatment conditions are : MLVSS 4g/L, sludge loading 0.2~0.4kgCODcr/kgMLSS.d, DO 2.5~3.5mg/L.The economic analysis presents that Hydrolysis- Acidogenesis-Two Stage Biological Contact Oxidation is more economical than SBR. The paper educed the k' of Hydrolysis- Acidogenesis-Two Stage Biological Contact Oxidation, on the basis of experiments by Grau model.