Removal of Gaseous Hydrogen Sulfide by a FeOCl/H(2)O(2) Wet Oxidation System

[Image: see text] The removal of gaseous hydrogen sulfide using FeOCl/H(2)O(2) was studied. The effects of the FeOCl dosage, the H(2)O(2) concentration, the reaction temperature, and the gas flow rate on the removal of H(2)S were investigated. The reaction products were analyzed, and the characterization of FeOCl was carried out by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and electron paramagnetic resonance spectroscopy. Furthermore, radical quenching experiments were carried out using butylated hydroxytoluene, isopropanol, and benzoquinone. It was found that the H(2)S removal rate for a H(2)S gas concentration of 160 ppm reached 85.6% when bubbling through 100 mL of an aqueous solution containing FeOCl (1 g/L) and H(2)O(2) (0.33 mol/L) at 293 K with a flow rate of 135 mL/min. Although the dissolution of chlorine in FeOCl was found to result in reduced catalytic performance, the activity was restored after soaking the catalyst in concentrated hydrochloric acid (37%) and subsequent calcination. The mechanism of H(2)S removal was also discussed, and it was found that this process was controlled by H(2)S diffusion. FeOCl was found to activate H(2)O(2) and produce radicals, such as (•)OH and (•)O(2)(–), resulting in the formation of a water film rich in radicals on the FeOCl surface. Following the diffusion of H(2)S into the water film, it underwent oxidation by radicals to produce SO(4)(2–). Overall, the catalyst and the product can be effectively separated.