Abstract:Non-ferrous smelter flue gas is a major anthropogenic source of arsenic emissions in China.Because the composition of non-ferrous smelter flue gas is complicated, efficient removal of gaseousarsenic remains a significant challenge. Biomass charcoal usually contains abundant functional groupson its surface, which have a strong affinity for arsenic. Therefore, a modified biomass charcoalEnergy Environmental Protectionadsorbent was synthesized by a hydrothermal method from Camellia oleifera shells. The analysis andcharacterization results of the adsorbent confirmed that the prepared biomass charcoal had a porous andspherical structure with a large specific surface area (532.441 m/g) and a well-developed microporousstructure (0.647 cm/g). FTIR confirmed that the prepared biomass charcoal contained a large numberof oxygen-containing functional groups such as C—O and CO. Gaseous arsenic adsorptionexperiments revealed that the optimal adsorption temperature of the biomass charcoal for arsenic was400 ℃, and its maximum arsenic adsorption capacity reached 16.14 mg/g, which was superior to that oftraditional mineral adsorbents. The adsorption capacity of biomass charcoal adsorbent at theconcentrations of 8 g/kg SO, 10 g/kg HCl, and 16% CO maintained an adsorption capacity above 10mg/g, demonstrating a strong resistance to acid gas poisoning. Furthermore, the presence of O insmelting flue gas enhances arsenic removal, whereas HO has a slight inhibitory effect. The final arsenicadsorption product was characterized using X-ray photoelectron spectroscopy (XPS) and inductivelycoupled plasma-high performance liquid chromatography (ICP-HPLC). The dominant arsenic species inthe adsorption product was As, which accounted for 62.7% of total arsenic at 250 ℃ and under a pureN atmosphere. Upon increasing the adsorption temperature to 400 ℃ and O volume concentration to6%, the proportion of As increased to almost 100%, indicating that arsenic oxidation plays a crucialrole in arsenic removal. The proposed arsenic removal mechanism involves the physical adsorption ofgaseous arsenic trioxide on the biomass charcoal surface, followed by oxidation to stable diarsenicpentoxide by the oxygen-containing functional groups, ultimately leading to arsenic purification. Thespent biomass charcoal was regenerated by alkaline boiling. After 10 regeneration cycles, the arsenicremoval efficiency of biomass charcoal decreased by only 30%, demonstrating that the biomasscharcoal from Camellia oleifera shells exhibited good regeneration potential. These results demonstratethe excellent industrial application potential of the biomass charcoal for arsenic pollution control. Close-