Enhanced Catalytic Ozonation of Phenol Degradation by Mn-Loaded γ-Al₂O₃ Catalyst: A Facile Strategy for Treating Organic Wastewater

Abstract

Heterogeneous catalysis ozonation technology can achieve efficient treatment of refractory organics in industrial wastewater due to its advantages including fast reaction speed, high ozone utilization rate, low catalyst loss and low cost and has a broad application prospect. The development of efficient and stable heterogeneous ozone catalytic materials is the key to promoting the application of this technology in industrial wastewater treatment. Based on this, an Mn/Al2O3 catalyst was successfully prepared by impregnation method using 3~5 mm γ-Al2O3 pellets as the carrier, and the surface morphology characteristics, elemental state and phase composition of the catalyst were investigated by SEM-EDX, XRD and XPS. The results showed that Mn was successfully loaded onto the surface of a γ-Al2O3 carrier. On this basis, intermittent single factor experiments were conducted to systematically investigate the effects of catalyst dosage, pH, and ozone concentration on the catalytic performance of phenol. It was found that under the optimal conditions of a catalyst dosage of 100 g (filling height of 14.2 cm), pH of 7, and ozone concentration of 4 mg/L (gas volume of 1 L/min), the removal efficiencies of 800 mL 100 mg/L of simulated phenol wastewater reached 100% after 60 min of reaction. The removal efficiencies of the catalyst still reached 95.8% within 60 min even after the fifth cycle reaction, indicating excellent reusability of the catalyst. This work provides a facile strategy for the treatment of refractory organics in industrial wastewater.

Keywords

• heterogeneous catalytic ozone oxidation
• phenol
• γ-Al₂O₃
• manganese oxide