Mineralization of Recalcitrant Organic Pollutants in Pulp and Paper Mill Wastewaters through Ozonation Catalyzed by Cu-Ce Supported on Al2O3

There has been great interest in developing cost-effective and high-performance catalysts for the ozonation treatment of biologically refractory wastewaters. This study developed a novel copper-cerium oxide supported alumina (Cu-Ce/Al2O3) catalyst for the catalytic ozonation of pulp and paper mill wastewater. The evenly distributed composite metal oxides on the surface of catalysts evidently improved the catalytic degradation efficiency. The Cu-Ce/Al2O3/O-3 process increased the total organic carbon (TOC) removal by 6.5%, 9.5%, 24.5%, and 35.5%, compared with Ce/Al2O3/O-3, Cu/Al2O3/O-3, Al2O3/O-3, and ozone alone processes, respectively. The enhanced catalytic ozonation efficiency was mainly ascribed to an increased hydroxyl radical (center dot OH)-mediated ozonation, both in the bulk solution and on the surface of catalysts. The surface hydroxyl groups (-OHs) of Al2O3 along with the deposited Cu-Ce oxides greatly enhanced the catalytic performance. This work illustrated potential applications of Cu-Ce/Al2O3 catalyzed ozonation for the advanced treatment of biologically recalcitrant wastewaters.