Chiang Mai Journal of Science

Fenton and Fenton-like reactions are well known to be a very effective method in the removal of many hazardous organic pollutants. The reactions are activated by the mixtures of hydrogen peroxide (H₂O₂) and catalysts (metal iron; Fe⁰, Fe²⁺ and Fe³⁺) to generate hydroxyl free radical (OH^l), which is a strong oxidizing agent in the acidic pH range of 2.5 - 3.0. This study aimed to observe a synergistic catalytic action on Fenton and Fenton-like reactions with a combination of catalysts for Methyl Orange decolorization using experimental methodology via multilevel factorial design. It was revealed that efficiency of decolorization from a synergistic catalytic action was higher than the reactions with either Fe⁰, Fe²⁺ or Fe³⁺ alone on Methyl Orange decolorization. In the mixtures with Fe⁰, Fe²⁺, and H₂O₂ at pH 3 within 10 min, efficiencies of Methyl Orange removal with initial concentration of 75 mg/l were 84 and 99 % when the reaction systems were added with 10 mg/l of each synergistic catalyst and 25 and 50 mg/l of H₂O₂ with the rate of decolorization of 6.69 and 7.47 mg/l/min, respectively.