Effective Removal of Vanadium in Wastewater by Activated Iron: A Combined Experimental and Dft Studies

Abstract

In this study, activated iron was prepared by reduced iron powder, which was used to treat vanadium pollution in simulated wastewater as well as in actual wastewater through batch experiments. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) of activated iron before and after reactions were carried out. The results showed that the final vanadium removal rate by activated iron in wastewater could reach more than 90% under the optimal reaction conditions. In addition, the interactions between Fe3O4, Fe and H3VO4 were investigated by density functional theory (DFT), which showed a good agreement with experimental data. The vanadium removal mechanism involved a variety of reactions, such as redox reaction of V(V) to V(III) and V(IV), adsorption by electrostatic attraction on the Fe (110), (111), and (311) and Fe3O4 (001), (110), (111) and (311) crystal surfaces, precipitation and co-precipitation to form the Fe-V precipitate.

Keywords: reduced iron powder, activated iron, vanadium, Wastewater, density functional theory (DFT), Reaction mechanism