Aniline degradation by peroxydisulfate activated with magnetic Fe–Mn oxides composite: efficiency, stability, and mechanism

Magnetic Fe–Mn oxides composite prepared by a chemical co-precipitation method was used as a heterogenous peroxydisulfate (PDS) catalyst for the decomposition of aniline. The catalyst was investigated by X-ray diffraction (XRD) while morphologies of powders were monitored by scanning electron microscope (SEM) and transmission electron microscopy (TEM). The catalytic performance was evaluated including the PDS concentration, catalyst dosages, solution pH value, reaction temperature and reusability. Furthermore, the mechanism of the composite activating PDS was explored through free radical quenching experiment. The result demonstrated that the degradation process kinetic well correlated to the pseudo-first order reaction kinetics. The pseudo-first order rate constant was markedly influenced by the catalyst loading and reaction temperature. The catalyst exhibited good stability, which favored the catalyst to be reused from aquatic environment.