Effect of chemical activation of an activated carbon using zinc chloride on elemental mercury adsorption

Hg0 adsorption experiments with different kinds of activated carbons (ACs) were conducted in nitrogen environment to study the effects of ACs with different surface characteristics on adsorption. Three kinds of ACs prepared by steam activation did not adsorb elemental mercury (Hg0) in nitrogen environment, while another kind of AC prepared by chemical activation using zinc chloride (ZnCl2) showed significant Hg0 adsorption capability in the same experimental conditions because Hg0 was oxidized by the oxidative elements on the surface of AC. ACs without oxidative elements did not adsorb Hg0 through physical adsorption in nitrogen environment. It was therefore concluded that Hg0 adsorption by AC was a chemical adsorption process.