Activation of Persulfate by Magnetic MnFe2O4-bentonite for Catalytic Degradation of 2,4-Dichlorophenol in Aqueous Solutions

Magnetic MnFe2O4-bentonite was synthesized by chemical co-precipitation method（CCM） and applied as catalyst in heterogeneous activation of persulfate（PS） to oxidize a target pollutant, 2,4-dichlorophenol（2,4-DCP）, in aqueous solutions. The surface morphology and structure of MnFe2On-bentonite were characterized by X-ray diffraction（XRD）, scanning electron microscope（SEM）, energy dispersive X-ray（EDX） and X-ray photoelectron spectroscopy（XPS） analyses.The catalytic activity of MnFe2O4-bentonite for 2,4-DCP degradation was evaluated considering the effects of various process parameters, such as mass ratio of MnFe2O4 to bentonite, concentration of catalyst, PS concentration, and pH. The MnFe2O4-bentonite hybrid exhibited higher catalytic activity than pure MnFe2O4. Treatment with 5 g/L MnFe2O4-bentonite at 30℃ for 240 rain oxidized 92% of 100 mg/L 2,4-DCP（70.2% mineralization）, whereas treatment with pure MnFe2O4 under the same condition oxidized only 70% of the pollutant. This result indicate the erdlanced performance of the activated PS. Moreover, MnFe2O4-bentonite exhibits stable performance with minimal loss in activity after five successive runs. Thus, MnFe2O4-bentonite could be a promising catalyst in oxidative degradation of 2,4-DCE