Previous entrained-flow tests conducted under elemental mercury (Hg-0)-laden air found that significant amounts of oxidized mercury (Hg2+) are not adsorbed onto cupric chloride-impregnated carbon (CuCl2-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 CuCl2-AC and DARCO Hg-LH.These test results suggested that CuCl2-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 CuCl2 is re-adsorbed at the site Of CuCl2-AC available for adsorption. The resultant oxidized mercury was also found to be easily re-adsorbed onto CuCl2-AC and DARCO Hg-LH in the filter connected to the entrained-flow reactor. (C) 2009 Elsevier B.V. All rights reserved.