Treatment Of Waste Water Of Oil Fields In Laboratory

This thesis is the study in laboratory of treatment of waste water. The processing system and parameter of biology treatment is decided by experiment. The biodegradability is improved. CODcr and oil can meet the standard.The meaning of the thesis is to help solving the actual problem, saving resource and building up the good visualize for petrochina.The CODcr is not request when the waste water is treated in the old processing system . According to the National Regulatory and Laws, the discharge of produced water should be complied with the second level requirements (CODcr < 150mg/L) of the national standard GB8976-1996 (The Standard of Comprehensive Discharge of Polluted Water ). After the produced water pass through the treatment of present facilities in oil fields, there are still some water unsatisfied to the standard requirements as CODcr in produced water is up to 300 ~ 400 mg/L and oil is about 10 ~30mg/L. Therefore, the key problem for the discharge of produced water is to decrease CODcr and Oil content to the extent of regulatory requirements. There is no mature technique using in produced water. How to improve the biodegradability is important.The article has carried on the studies of screening of the degradeation bacteria and cultivating of active sludge, and determined the important process factors such as pH(7.3), temperature( 25~30 ),treatment period(anaerobic treatment: 12h, aerobic trearment:8h) and so on. The laboratory research results show that A/O combined method is feasible to decrease CODcr in the produced water. After the treatment for high concentration of CODcr and undegradable produced water using A/O combined process, the finally removing rate is 77% for CODcr (the average concentration of CODcr in output water is 101mg/L ), and 84% for oil (the average concentration of oil in output water is 5.9mg/L). The water quality after treatment is obey the requirements of GB8978-1996 "The Standard of Comprehensive Discharge for Polluted Water".It is the starting of A/O processing system. The treating effect need to be validated and applied in the field. The processing system and parameter of biology treatment need to be optimized. The reactor need to be studied thoroughly.