[Characteristics of Advanced Treatment of Treated Petrochemical Water by O-BAC and Analysis of Consortium Structure].

The advanced treatment of treated petrochemical water by Ozone-Biological Activated Carbon (O-BAC) was carried out in this study. The effect of O on the removal of Chemical Oxygen Demand (COD) and Spectral Absorption Coefficient (UV) were investigated. The characteristics of organic matter and the microbial consortium structure of BAC were also investigated at 20 mg·L of O dosage concentration, 40 min of O single stage contact time and 1.5 h of the empty bed residence time of BAC. Results showed that the effluent COD concentration of O-BAC was 24 mg·L with the removal efficiency of 40.4%. The COD removal efficiency of O-BAC was higher than that for the BAC process. The UV removal efficiency of O-BAC was 55.1%. Meanwhile, UV correlated with COD with a correlation coefficient of 0.89. The percentage of dissolved organic matters with relative molecular weight less than 1×10 increased from 69.0% to 87.0% after O oxidation. The NPOC removal efficiency of O-BAC (45.8%) was higher than that of the BAC process (23.0%). The NPOC removal efficiency of the BAC unit was mainly achieved by reduction of dissolved organic matters with relative molecular weight less than 1×10. GC-MS analysis results showed that organic substances such as alkanes, unsaturated esters, and phenols had been removed by O oxidation. The micro ecological environment of the BAC unit had been significantly improved after O oxidation, and the genera with relative abundance over 1.0% increased from 6 to 11. The combined O-BAC system can be applied to the advanced treatment of petrochemical treated water.