Activation of persulfate by magnetic MnFe2O4-bentonite for catalytic degradation of 2,4-dichlorophenol in aqueous solutions

Magnetic MnFe 2 O 4 -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 MnFe 2 O 4 -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 MnFe 2 O 4 -bentonite for 2,4-DCP degradation was evaluated considering the effects of various process parameters, such as mass ratio of MnFe 2 O 4 to bentonite, concentration of catalyst, PS concentration, and pH. The MnFe 2 O 4 -bentonite hybrid exhibited higher catalytic activity than pure MnFe 2 O 4 . Treatment with 5 g/L MnFe 2 O 4 -bentonite at 30 °C for 240 min oxidized 92% of 100 mg/L 2,4-DCP(70.2% mineralization), whereas treatment with pure MnFe 2 O 4 under the same condition oxidized only 70% of the pollutant. This result indicate the enhanced performance of the activated PS. Moreover, MnFe 2 O 4 -bentonite exhibits stable performance with minimal loss in activity after five successive runs. Thus, MnFe 2 O 4 -bentonite could be a promising catalyst in oxidative degradation of 2,4-DCP.