Abstract: Activated carbon with micropores was prepared from coconut carbon using steam activation by secondary activation. N₂-adsorption isotherm, mathematical models such as D-R equation and BJH methods were used to characterize the properties of the prepared activated carbons. With mercury chloride as pollution targets, the adsorption properties of activated carbon for Hg²⁺ were investigated. The results indicated that the adsorption of Hg²⁺ was obviously influenced by surface area and pore structure of activated carbon. The process of adsorption was a two speed process with rapidly adsorption and slowly adsorption coexisting. This process could be well described by Lagergren pseudo second order model. The adsorption isotherm experiment showed that adsorption of Hg²⁺ on activated carbon is an exothermic and single molecular layer adsorption process. It could be fitted by Langmuir isotherm model.

Key words: activated carbon, mercury chloride, specific surface properties, adsorption kinetics, adsorption isotherm