p-Arsanilic acid decontamination over a wide pH range using biochar-supported manganese ferrite material as an effective persulfate catalyst:Performances and mechanisms

Direct chemical oxidation and pure adsorption could not effectively remove p-Arsanilic acid(p-ASA)and the released inor-ganic arsenic.Herein,one novel biochar supported MnFe_(2)O_(4)(MFB)was synthesized and adopted for p-ASA degradation and synchronous adsorption of the generated inorganic arsenic.The MFB/persulfate(PS)system could remain effective under a wide pH range(3.0-9.0),and the released arsenic could be removed simultaneously by MFB.Mechanism investiga-tion revealed that the functional groups of MFB(i.e.O-C=O and C=O),Fe and Mn oxides on MFB all contributed to PS activation.O_(2)^(·−)and^(1)O_(2)were the main reactive oxygen species(ROS)responsible for p-ASA degradation,and^(1)O_(2)was the predominant ROS.Besides,the MFB possessed superior reusability.Therefore,it is expected to develop a potential method for organic arsenic contaminants removal via an oxidation-adsorption process,and the results could also shed light on the better understanding of the PS activation mechanisms.