Enhancing the adsorption of vapor-phase mercury chloride with an innovative composite sulfur-impregnated activated carbon

► The innovative composite sulfur-impregnation process successfully combined the impregnation of vapor-phase S0 and aqueous-phase Na2S onto the surface of activated carbons originally derived from the pyrolysis of waste tires. ► Maximum adsorptive capacity of HgCl2 up to 5236 μg-HgCl2/g-C was observed for the composite sulfur-impregnated AC, which was approximately 73 times higher than those for the single S0 or Na2S sulfur-impregnated AC. ► Furthermore, the adsorptive capacity of HgCl2 at temperatures below 70 °C was dominated by physical-adsorption, while that above 70 °C was dominated by chemisorption.