Degradation of Orange II in aqueous solution by a novel electro/Fe3O4 process.

The removal of Orange II in aqueous solution by Fe3O4 enhanced anode oxidation (EC/Fe3O4 process) was performed in an electrochemical reactor. The process involved the use of a dimensionally stable anode and a stainless steel cathode. Fe3O4 was performed as particle electrodes to increase mass transfer coefficient and reduce energy consumption. Various parameters were investigated to optimize the process, including initial pH, Fe3O4 dosage and current density. The results indicated that the decolorization of Orange II followed pseudo first-order kinetics. The decolorization was favorable in acidic media than in neutral or alkaline solution, while it increased with the Fe3O4 dosage and current density. The total organic carbon (TOC) removal efficiency was 33.2% after 120 min reaction. The X-ray photoelectron spectroscopy was applied to investigate the surface properties of Fe3O4 before and after reaction.