Investigation of Electro-Fenton process in degradation of phenol from aqueous solutions

Electrochemical methods as one of the advanced oxidation processes (AOPs), have been applied effectively to degrade recalcitrant organics in aqueous solutions. In the present work, the performance of electro-Fenton (EF) method using iron electrodes on the degradation of phenol was studied. In this study, a lab-scale EF batch reactor equipped with four electrodes and a DC power supply was used for removing phenol. The effect of operating parameters such as pH, voltage, H2O2 and initial phenol concentration and operating time were evaluated. We added H2O2 manually to the reactor while iron anode electrode was applied as a ferrous ion source. It was found that initial pH of the solution, initial H2O2 concentration, applied voltages were highly effective on the phenol removal efficiency in this process, so that 87% of phenol after 15 min of reaction at pH=3.0, voltage 26 V and H2O2 100 mg/L was removed. Phenol removal efficiency decreased with increasing pH, so that at pH 10, after 15 min, efficiency was 11%. To remove 99.99% phenol at pH 3, 100 mg/L concentration of H2O2 and voltage 26 V for 60 min was required. Electro-Fenton process using iron electrodes for phenol degradation and remediation of wastewater could be a promising process.