Studies on the reaction mechanism of Cu/SiC catalytic oxidation for degradation of methyl orange in presence of microwave.

The removal of methyl orange (MO) in a copper-loaded silicon carbide (Cu/SiC) system under microwave (MW) irradiation was studied. Cu/SiC was synthesized by employing an impregnation method and the effects of parameters such as reaction time, catalyst dosage, hydrogen peroxide (H2O2) dosage, microwave power and pH on the rate of degradation of MO were also studied. The obtained results showed that almost complete degradation was obtained in the presence of Cu/SiC catalyst within 8 min of irradiation when 100 mL of MO solution (20 mg/L), 3 ml/L of H2O2, 2 g/L of catalyst dose, 600 W of MW power, and pH 7 were applied. The Cu-bearing catalyst with H2O2 formed a Fenton-like system and the rate of generation of hydroxyl radicals (·OH) was also accelerated by subjecting to MW. From the kinetic analysis, it is revealed that the degradation of MO using the MW-Cu/SiC-H2O2 system follows the pseudo-first-order.