Microwave-induced catalytic oxidation process for treatment of phenol in water with Fe2O3/Al2O3 catalyst

The ferric oxide catalyst was prepared by the dipping- calcination method using gamma-Al2O3 as a carrier and the microwave- induced oxidation process was developed to treat phenol in water. The catalyst structure was determined by XRD, XRF and N-2 adsorption. The effects of operating conditions on the catalyst activity, the using life of the catalyst and the reaction kinetics were studied. The results show that alpha-Fe2O3 is loaded on the surface of gamma-Al2O3 and the content of alpha-Fe2O3 in the catalyst is 3.71 %. Under the optimal treatment conditions of phenol concentration of 100 mg/L, microwave power of 400 W, irradiation time of 5 min, catalyst amount of 60 g/L, H2O2 concentration of 600 mg/L and pH > 4, a phenol removal rate of 97.98% is obtained. The catalyst can be reused more than 20 times remaining a phenol removal rate of 96. 34 %. The oxidation process can be divided into two stages, both of them are in accord with the first-order reaction kinetics.