Activated carbons (ACs) were impregnated with potassium halides (KX) to enhance the removal efficiency of elemental mercury (Hg0). In this work, the impregnation effect of potassium bromide (KBr) and potassium iodine (KI) were investigated. The surface properties of KXa??ACs were determined by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The pore structures and total pore volumes of the KXa??ACs were analyzed using the N2 /77a??K adsorption isotherms. The Hg0 removal efficiency of KBra??ACs and KIa??ACs was studied under simulated flue gas conditions. The effects of KI and KBr loading, adsorption temperature, and flue gas components on Hg0 removal efficiency were also investigated. The results showed that the Hg0 removal efficiency of the ACs was significantly enhanced by KI or KBr impregnation, and KIa??ACs showed higher Hg0 removal efficiency than KBra??ACs under the same conditions. An increase in KI or KBr loading and higher adsorption temperatures improved the Hg0 removal efficiency, indicating that chemisorption occurred due to the reaction between Xa?? and Hg0. The lower extent of Hg0 removal exhibited by the KBra??ACs than by the KIa??ACs was due to the difficulty of Br2 formation on the surfaces.
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