Degradation of 2,4-dichlorophenol by Electro-Fenton Oxidation Process

An electro-Fenton oxidation system using a gas diffusion electrode as the cathode and Ti/SnO2-Sb2O5-IrO2 as the anode was constructed and used for the degradation of 2,4-dichlorophenol(2,4-DCP).Based on an investigation of the optimal potential for the gas diffusion electrode to generate H2O2,the effects of Fe2+ and reaction time on the degradation of 2,4-DCP were studied.Moreover,the variations of H2O2,Fe2+ and Cl-concentrations during 2,4-DCP degradation were also investigated.The results showed that the degradation of 2,4-DCP was attributed to the co-action of electro-Fenton oxidation and anodic oxidation.Under the cathodic potential of-0.7 V,Fe2+ concentration of 0.15 mmol/L and reaction time of 60 minutes,89.1% of 2,4-DCP was removed.The characteristic absorption peak of 2,4-DCP disappeared completely,and the 2,4-DCP removal rate reached 100% after 120 minutes of treatment.TOC concentration was reduced to 9.15 mg/L,and its removal rate reached 79.4% after 240 minutes of treatment.There was a negative correlation between H2O2 and Fe2+.After degradation,the chlorine in the molecule of 2,4-DCP existed in the form of Cl-in the solution.