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 inorganic arsenic. Herein, one novel biochar supported MnFe2O4 (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 investigation 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 O-1(2) were the main reactive oxygen species (ROS) responsible for p-ASA degradation, and O-1(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. [GRAPHICS] .

Automated summary

A novel biochar supported MnFe2O4 (MFB) was synthesized and used for the degradation of p-Arsanilic acid (p-ASA) and the simultaneous adsorption of released inorganic arsenic. The MFB/ persulfate (PS) system showed high efficiency in removing arsenic under a wide range of pH values.