Degradation and Mineralization of Malachite Green Dye in Aqueous Solution by Electro-Fenton Process Using Iron Electrodes

The electrochemical degradation of a synthetic solution of malachite green (MG) was studied using electro-Fenton process (EFP) under batch conditions. The studies used iron electrodes to investigate the influence of operating parameters such as reaction temperature, distance between the electrodes, electrolysis time, and initial dye concentration. The values of 1 cm as distance between the electrodes and 50°C as temperature were found to be the optimum operating parameters for the efficient degradation of MG dye. When the temperature was greater than 50°C, H2O2 self-decomposed. After 30 minutes of electrolysis, TOC removal was only 76.5% when no H2O2 was added to the solutions (ECP), while the presence of H2O2 greatly improved TOC removal by more than 95%. For a solution of 1000 mg L-1 MG dye, degradation was complete after only 30 minutes. Furthermore, despite high removal efficiency of COD in EFP, energy consumption was less than in ECP.