A novel synthesis method of mesoporous carbon loaded with Fe3O4 composite for effective adsorption and degradation of sulfamethazine

In this work, mesoporous carbon (MC) loaded with Fe3O4 composite material (Fe3O4/MC) was synthesized using a novel synthesis method. Fe3O4 nano particles distribution was homogeneous on the MC surface through the observation of morphologic and structural techniques. Adsorption amount of SMZ increased as the composite dosage increased, however, it decreased as temperature and pH increased. Results showed that 50.0% SMZ was removed in the Fe3O4/MC + persulfate (PS) system under the following conditions: a SMZ initial concentration of 50 mg.L-1, a Fe3O4/MC dosage of 0.1392 g, a PS dosage of 0.0476 g, at 30 degrees C and a pH of 3.0. Degradation experiments showed that the SMZ removal efficiency was enhanced as both the composite dosage and temperature increased. However, its efficiency decreased as the initial SMZ concentration and pH increased. Increasing the PS concentration caused the SMZ removal efficiency to first increase and then decrease. X-ray photoelectron spectroscopy (XPS) result showed that 1.5% of Fe(II) was transformed into Fe(III), revealing that electron transfer occurred from Fe(II) species. Electron paramagnetic resonance indicated sulfate radicals dominated the reaction process of SMZ degradation in Fe3O4/MC + PS system. Two possible degradation pathways of SMZ could be concluded: cleavage of the S-N bond and smiles-type rearrangement. Overall, it is demonstrated that a novel synthetic method can be successfully used to prepare Fe3O4/MC, which can effectively activate PS to degrade SMZ. (C) 2019 Elsevier B.V. All rights reserved.