The removal efficiencies and mechanism of aniline degradation by peroxydisulfate activated with magnetic Fe-Mn oxides composite

Abstract

The Fe-Mn oxides composite prepared by a chemical co-precipitation method was used as a heterogenous peroxydisulfate catalyst for the decomposition of aniline. This study investigated the mechanism of aniline degradation by PDS activated with catalyst. Reactive species resulting in the degradation of aniline was investigated via radical quenching experiments with different scavengers, including methanol, tert-butyl alcohol, EDTA and sodium azide. Based on the experiments made here, it is speculated that the predominant reactive species responsible for the degradation of aniline may be holes and singlet molecular oxygen rather than SO4·− and ·OH radicals. The degradation of compounds in catalyst/peroxydisulfate system was put forward. The three possible intermediates were speculated by high performance liquid chromatography-mass spectrometry, and two possible degradation pathways were proposed. HIGHLIGHTS Magnetic Fe-Mn particles based on spinel-type ferrite MnFe2O4 were synthesized.; Diagrammatic sketch of aniline degradation mechanism by peroxydisulfate in the presence of MnFe2O4 system was demonstrated.; Three main intermediate products and two possible paths were studied.;

Keywords

• fe-mn oxides
• intermediate
• oxidation
• peroxydisulfate
• reaction mechanism