Treatment of phenol wastewater by microwave-induced ClO2-CuOx/Al2O3 catalytic oxidation process

Abstract The catalyst of CuO x /Al 2 O 3 was prepared by the dipping-sedimentation method using γ-Al 2 O 3 as a supporter. CuO and Cu 2 O were loaded on the surface of Al 2 O 3 , characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). In the presence of CuO x /Al 2 O 3 , the microwave-induced chlorine dioxide (ClO 2 ) catalytic oxidation process was conducted for the treatment of synthetic wastewater containing 100 mg/L phenol. The factors influencing phenol removal were investigated and the results showed that microwave-induced ClO 2 -CuO x /Al 2 O 3 process could effectively degrade contaminants in a short reaction time with a low oxidant dosage, extensive pH range. Under a given condition (ClO 2 concentration 80 mg/L, microwave power 50 W, contact time 5 min, catalyst dosage 50 g/L, pH 9), phenol removal percentage approached 92.24%, corresponding to 79.13% of COD Cr removal. The removal of phenol by microwave-induced ClO 2 -CuO x /Al 2 O 3 catalytic oxidation process was a complicated non-homogeneous solid/water reaction, which fitted pseudo-first-order by kinetics. Compared with traditional ClO 2 oxidation, ClO 2 catalytic oxidation and microwave-induced ClO 2 oxidation, microwave-induced ClO 2 catalytic oxidation system could significantly enhance the degradation efficiency. It provides an effective technology for the removal of phenol wastewater.