Synergistic effects of Fe-Mn binary oxide for gaseous arsenic removal in flue gas.

High-efficient and economic sorbents are highly desired for arsenic (As) emission control in flue gas from coal-fired power plant. A series of Fe-Mn binary oxides were prepared by a facile method, and their behaviors for gaseous arsenic removal in flue gas were investigated. The binary oxide exhibited a remarkable synergistic effect for arsenic removal compared with Mn or Fe monometallic oxide. The possible effects of CO 2 , NO, SO 2 , and O 2 on the removal performance were also studied. The adsorption ability was excellent and stable in simulated flue gas conditions. X-ray photoelectron spectroscopy (XPS) and high-performance liquid chromatography atomic fluorescence spectroscopy (HPLC−AFS) coupling system were applied to analyze the species of surface-adsorbed arsenicals and soluble arsenicals. It was confirmed that the good sorption performance resulted from oxidation of As 2 O 3 (As(III)) to As 2 O 5 (As(V)) by Mn oxide and followed by efficient adsorption of As(V) on Fe oxide. Considering the toxicity of pentavalent arsenicals is lower than trivalent arsenicals, the oxidation of arsenic compounds can not only enhance its removal capacity but also decrease the toxicity of arsenicals after capture. ga1 ● A binary oxide exhibited excellent adsorption performance for gaseous arsenic. ● The good removal ability resulted from the synergic effects between Fe and Mn. ● The synthesized sorbents could greatly reduce the toxicity of arsenical in flue gas. [ABSTRACT FROM AUTHOR]