Abstract: Analysis and evaluation of catalytic ozonation technology in the third-stage (deep) treatment of wastewater is of great significance to the selection of wastewater quality improvement technology in refining and chemical enterprises. Through on-site investigation, operational water quality data collection and sampling analysis of two typical heterogeneous catalytic ozonation units for oily and saline wastewater in industrial operation, the results of statistics and analysis of chemical oxygen demand (COD) in inlet and outlet water showed that the catalytic ozonation had a certain effect on the removal of COD in oily and saline wastewater, but the deactivation of the catalyst was faster. After a period of operation, the average removal concentration of COD was only about 10 mg/L, which was similar to that of non-catalytic ozonation and had little effect on improving biological oxygen demand (BOD5).

Key words: refinery wastewater, advanced treatment, ozone, catalytic oxidation