Catalytic wet air oxidation of Aqueous solutions of substituted phenols

Catalytic wet air oxidation (CWAO) of aqueous solutions of phenol, 2-chlorophenol and 4-nitrophenol were studied using Cu/CeO2 with 4% of copper as catalytic material. The catalyst was prepared by an impregnation method and characterized by X-ray diffraction (XRD), BET surface area, oxygen storage capacity (OSC), temperature programmed reduction (TPR), electron paramagnetic resonance (EPR) and XPS. The reaction was carried out in a batch reactor at T=160 °C and 1.0 MPa. Cu/CeO2 catalyst was found effective in CWAO. On the basis of characterization data, it is suggested that the high activity of the copper–ceria catalyst is related to the modification of the structural and redox properties of the cerium oxide on copper addition. The ratio BOD5/COD was measured to evaluate the biodegradability. Pretreatment by CWAO under operating conditions resulted in effluents whose biodegradation rates were significantly higher than those of the original.