The optimal factors of electro-Fenton process to decolorization the azo ddye methyl orange in aqueous medium

In this study, the electro-Fenton system had been established and graphite plates were selected as electrodes. Azo dye methyl orange was used as the model pollutant. The electrolytic bath was divided into cathode cell and anode cell two parts. The two cells were connected by salt bridge. The kinetics of methyl orange decoloration in these two cells was obtained in the optimal conditions. The results indicate that the decay rate of methyl orange was higher in the cathode cell in the case of lower electric current for more H₂O₂ detected. The discolored rates reach 96.23% and 85.24% with the electric current density 0.5mA/cm² and 2mA/cm² respectively. The kinetics of the cathode process should be regarded as first-order reaction. But in the anode cell the decay rate of methyl orange was increased with the current density increasing when the electric current density under 2mA/cm². The kinetics of the anode process should be regarded as zero-order reaction.