Fenton-like degradation of 2,4-dichlorophenol using Fe3O4 magnetic nanoparticles

Fenton-like degradation of 2,4-dichlorophenol (2,4-DCP) in aqueous solution was investigated over Fe3O4 magnetic nanoparticles (MNPs) as catalyst. The obtained samples were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM). X-ray photoelectron spectroscopy (XPS), nitrogen adsorption-desorption isotherms, and physical property measurement system (PPMS). The catalytic results showed that Fe3O4 MNPs presented good properties for the degradation and mineralization of 2,4-DCP, achieving complete decomposition of 2,4-DCP and 51% of TOC removal after 180 min at reaction conditions of H2O2 12 mM, Fe3O4 MNPs 1.0 g/L, 2,4-DCP 100 mg/L, pH 3.0 and T30 degrees C. The effect of different reaction parameters such as initial pH, H2O2 dosage, Fe3O4 MNPs addition, initial concentration of 2.4-DCP and temperature on two-stage first-order kinetics of 2,4-DCP degradation was studied. A high utilization efficiency of H2O2 calculated as 73% was observed. According to the analyses of iron leaching, reactive oxidizing species and degradation intermediates, a possible mechanistic steps of 2,4-DCP degradation dominated by center dot OH reactions (especially by free center dot OH in the bulk solution) were proposed. Besides, stability and reusability of Fe3O4 MNPs were tested. (C) 2012 Elsevier B.V. All rights reserved.