Degradation of Acid Red B by Manganese doped iron oxychloride and Permonosulfate: Performance and Inhomogeneous Activation Mechanism

Abstract manganese doped iron oxychloride (Mn-FeOCl) was synthesized by partial pyrolysis method. The Mn-FeOCl was used as heterogeneous catalyst to activate permonosulfate (PMS) for the degradation of azo dye acid red B(ARB) for the first time. The Mn-FeOCl was characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction spectroscopy (XRD). The effects of Mn-FeOCl dosage, PMS concentration, initial pH value, Cl ion concentration and humic acid (HA) dosage on the degradation of ARB by Mn-FeOCl/PMS were investigated. Results showed that the ARB was degraded effectively by Mn-FeOCl/PMS. The mineralization rate of ARB reached 42.5%. As the Mn-FeOCl dosage was 0.1g/L, PMS concentration was 1mmol/L, and ARB concentration was 0.05mmol/L, the degradation rate of ARB reached 99.4% in 30 minutes. With the increase of PMS dosage, Mn-FeOCl dosage, Cl− ion concentration and initial pH value, the decolorization effect of ARB increased. The reaction mechanism was analyzed by free radical quenching experiment and XPS. The main active species were determined as ·OH and SO4·− which generated by PMS activation. The SO4·−−was the main active species.