Study of an Air Diffusion Activated Carbon Packed Electrode for an Electro-Fenton Wastewater Treatment

Abstract

An air diffusion activated carbon packed electrode was used to promote the in-situ generation of hydrogen peroxide (H2O2) to support an electro-Fenton based method for the degradation of a typical dye, Methyl Orange (MO) at two different concentrations in an aqueous effluent (250mgL−1 and 97mgL−1). Electrochemical experiments were carried out using a one compartment cylindrical cell with granular activated carbon (GAC) configured as an air diffusion cathode. The efficiency of the electrode was explored as a function of H2O2 produced reaching a maximum value of 10mM. Experimental parameters such as applied current (300, 200, 100 and 50mA), initial Fe2+ concentration (0.2, 0.5 and 0.8mM) and electrode stability (10 cycles) were studied. High Total Organic Carbon (TOC) decay (90%) and color removal (100%) were obtained using this electrode under appropriate operation conditions. Consecutive degradation cycles of electro-Fenton process were performed in the electrochemical cell without great loss of the removal efficiency. Considering that, in the proposed packed electrode, the use of air diffusion GAC as cathode results in efficient degradation and cost reduction for the conventional electro-Fenton process, this electrode approach could constitute an excellent alternative for H2O2 generation when compared to conventional carbon electrodes.