Photo-assisted degradation of dye malachite green solution over Fe³⁺ C₂O₄-loaded resin in the presence of H₂O₂

In order to increase the reaction rate of the heterogeneous Fenton-like oxidation, the catalyst of Fe³⁺C₂O₄/R was used to catalytically decompose H₂O₂ for the removal of malachite green (MG) in aqueous solution under the visible light irradiation condition. The results show that the catalyst of Fe³⁺C₂O₄/R has a better catalytic reactivity to enhance the formation of ·OH compared with that of Fe³⁺/R. The higher the concentration of H₂O₂, the faster the reaction rate is. This reaction follows pseudo-first-order kinetics, the reaction rate constant has a good relativity with the concentration of H₂O₂. The catalyst of Fe³⁺C₂O₄/R could decompose H₂O₂ to degrade MG effectively at pH 3-9, the optimum pH is 6. The removal rate of MG increased with the increase of the dosage of catalyst. With the increase of the concentration of MG, the removal of MG by the adsorption turned to be by the oxidation. Repeated uses of catalyst did not decrease the removal rate of MG. The ferryl and hydroxyl radicals are both the reactive species in the oxidation of MG.