Efficient removal of dye from an aqueous phase using activated carbon supported ferrihydrite as heterogeneous Fenton-like catalyst under assistance of microwave irradiation

Ferrihydrite (Fh) stabilized inside porous activated carbon (Fh/AC) was prepared and used as a heterogeneous Fenton-like catalyst for oxidative degradation of methyl orange (MO) in simulated dye wastewater. The prepared catalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and N-2 adsorption-desorption isotherm. It was found that ferrihydrite was highly dispersed on the surface of pretreated AC and the as-prepared Fh/AC exhibited catalytic activity for degradation of MO in the Fenton like system consisting of solid catalyst, hydrogen peroxide (H2O2) and MO solution. With the assistance of microwave (MW) irradiation, the degradation efficiency of MO was significantly enhanced, indicating a synergetic effect of MW and Fenton-like system. The initial pH value of MO solution exerted notable influence on the reaction and acidic condition is more favorable to the degradation of MO. The recyclability of the catalyst was also evaluated by successive batch experiments under optimum conditions. (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.