Study On The Treatment Of Chinese Oil Field Produced Water In Africaby Coagulation Precipitation-Biological Aerated Filterprocess

African crude oil have been accounted for more than 20% of Chinese oil imports. In order to meet the needs of national economic development, China needs to continue to be imported from overseas in the future, which includes Africa. This involves the relationship between environmentand development. China must pay enough attention to the treatment of produced water.According to the characteristics of the produced water which comes from oil production base in Africa,this paper carried out the selection and integration of treatment technology for produced water, and put forward the coagulationprecipitation-BAF(biological aerated filter) process. This research aims to promote the development of African produced water’streatment by processing wastewater treatment demonstration. After the treatment of coagulationprecipitation-BAF, produced water can reach the discharge standard, so as to reduce the pollution of environment in Africa.We draw the following conclusions:1. Under the condition of laboratory setting. Coagulation and sedimentation reach to its best treatment effect when the dosage of PAM is 60mg/L, the dosage of PAC is 200mg/L and the sedimentation time is more than 30 min. At this time, the SS in wastewater can drop to 8 mg/L and the oil content can drop to 5.2 mg/L.2. By the studying of ceramsite, volcanic and zeolite, it is found that ceramsite has the shortest membrane-forming time and the number is 15 days. Ceramsite has an excellent removal efficiency of SS, oil and COD in wastewater, the removal efficiency is 93%-97%, 82%-89%, 70%-71% respectively.3. Pilot study of coagulationprecipitation-BAF shows that due to the environmental differences in field and laboratory, the output after coagulation sedimentation is not satisfied when the dosage of PAC is 200 mg/L, PAM is 60 mg/L. Adjust the PAM dosage to 70 mg/L, PAC dosage remain the same, the output can be much better, SS in output wastewater is less than 10 mg/L, oil content is less than 5 mg/L.Continue the pilot test after adjust the related parameters. 15 days later, the equipment reached a stable state. The removal efficiency of SS, oil and COD are 93%, 87%, 71% respectively. The output wastewater is better than the recommended standards of the oil production base in Africa.4.When the wastewater treatment amount of coagulationprecipitation-BAF is 2.5 m3/h, the investment of equipment is 191,800 RMB. For one ton wastewater, the reagent cost is 0.92 RMB, the electricity need is about 1.3 k W·h.In conclusion, the SS, oil and COD in produced water of oilfield in Africa can be removed effectively and economically. The output can meet the asked standards of Africa oilfield.