Enhancing Ozone Oxidation of Reverse Osmosis Concentrate Using Activated Carbon-Supported Cu-Co-Mn Catalysts

The refractory organic matters in the reverse osmosis concentrate of coal gasification wastewater were reduced via catalytic ozonation. Activated carbon-supported Cu-Co-Mn catalysts were prepared and the removal efficiency improved 9.6% than Cu-Mn catalysts with the second catalytic activity. The parameters of catalyst preparation were optimized by univariate analysis and response surface methodology. At the loading rate of 6.46%, calcination temperature of 625 degrees C, and calcination time of 5.0 h, the removal efficiency of chemical oxygen demand (COD) was highest at 80.67% under the pH of 9, ozone concentration of 1 g/L, and catalyst dosing rate of 1.10 g/L. It is confirmed that metal oxides were homogeneously distributed in the form of CuO, Co3O4, MnO2, and Mn2O3. Enhancement of specific surface area increased the number of activity sites and oxygen vacancies accelerated the formation of center dot OH. Hence, the activity of ozonation for refractory organic matters was improved. [GRAPHICS] .