Mercury oxidation and adsorption characteristics of chemically promoted activated carbon sorbents

Previous entrained-flow tests conducted under elemental mercury (Hg 0)-laden air found that significant amounts of oxidized mercury (Hg 2+) are not adsorbed onto cupric chloride-impregnated carbon (CuCl 2-AC) and brominated activated carbon (DARCO Hg-LH), but entrained to the gas phase. In this study, these sorbents were tested in a fixed-bed system and a filter-added entrained-flow system to further investigate Hg 0 oxidation and adsorption characteristics of CuCl 2-AC and DARCO Hg-LH. These test results suggested that CuCl 2-AC has different sites available for Hg 0 oxidation and Hg adsorption, and the resultant oxidized mercury generated from the reaction between Hg 0 and CuCl 2 is re-adsorbed at the site of CuCl 2-AC available for adsorption. The resultant oxidized mercury was also found to be easily re-adsorbed onto CuCl 2-AC and DARCO Hg-LH in the filter connected to the entrained-flow reactor.