At present,most oil fields have entered the middle and later stages of oil exploitation,and the water content of the crude oil produced has reached 70% to 80%,and some oil fields have even reached 90%.After separation of oil and water,a large amount of oily sewage is generated.If the oily sewage is directly discharged without treatment,it will not only cause pollution of the soil and water sources,but also cause economic losses to the country,but also endanger the interests of the oil field.In view of the characteristics of high suspended matter and organic matter concentration in the oil field sewage,the flocculation method is used to pretreat the oil field sewage to remove suspended solids; after flocculation and sedimentation treatment,the oil field sewage is subjected to deep treatment of supercritical water oxidation to remove the high concentration of oil field sewage refractory organic matter.Optimize the operation parameters of each process and draw the conclusions: (1) The best treatment conditions obtained by the flocculation sedimentation process are: when the pH is 7,the dosage of PAC is 1200 mg/L and the dosage of PAM is 50 mg/L,the treatment effect is the best.The pretreatment of flocculation agent makes COD removal reached 60%. (2) Under sufficient oxygen supply conditions, supercritical water oxidation has a good treatment effect.When the reaction temperature is 44,the reaction pressure is 24 MPa,and the reaction residence time is 10 min,COD removal can be much greater than 90 %.Orthogonal test results show that the reaction temperature is the most critical factor affecting the treatment effect.
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