Study on the Photocatalytic Oxidation of Malachite Green in UV/Fenton/Citric Acid System

Photo-Fenton reaction is a kind of advanced oxidation technology based on the reaction of hydroxyl radical. In order to further enhance the photocatalytic efficiency, with citric acid as the catalytic additive, and malachite green as the substrate, experiments on the photocatalytic oxidation of organic pollutants in UV/Fenton/Citric acid system were carried out. Effect of Fe(II) concentration, initial pH, concentration of citric acid, H₂O₂ dosage on the decolorization rate were investigated, and the optimal experimental conditions were obtained for the photocatalytic oxidation of malachite green. The results showed that the decolorization rate of malachite reached 82 % within 20 min under the optimal conditions, with Fe(II) concentration controlled at 5 g/L, pH between 3.0 and 5.0, citric acid concentration at 0.75 g/L, dosage of 30% H₂O₂ at 0.05 mL in one milliliter solution.