Catalytic ozonation of hard COD in coking wastewater with Fe2O3/Al2O3-SiC: From catalyst design to industrial application

Abstract

Development of robust, reactive, and inexpensive catalyst for pollutants abatement with catalytic ozonation is of great significance. Herein, the effect of a robust and easy-recovery catalyst, Fe2O3/Al2O3-SiC, for the catalytic ozonation of hardly biodegradable COD (hard COD) in coking wastewater had been explored. Al-O-Si bond formed on modified SiC through the substitution of hydrogen in surficial Si-OH groups by Al3+. The Lewis acid sites improved the adsorption of ozone and facilitated the formation of ·OH and O2·−. For coking wastewater treatment, the removal ratio of hard COD and the generation speed of hydroxyl radical (Rct) in the catalytic ozonation process were 71% and 253% higher than those in the ozonation group, respectively. Ozone utilization increased from 0.44 g COD removed/g O3 in the ozonation group to 1.42 g COD removed/g O3 in the Fe2O3/Al2O3-SiC catalytic ozonation group. In a full-scale application, Fe2O3/Al2O3-SiC catalytic ozonation decreased the consumption of O3 to 60 mg L−1 and decreased the operation cost by 50%. These results provided an approachable way for sharing the extraordinary capacity of ozone for contaminants remediation in industrial applications.