Our work involves experimental and simulation studies of the adsorption breakthrough and equilibria of ethyl benzene (a pollutant commonly encountered in industrial waste streams) on activated carbon in the presence of supercritical carbon dioxide. Frontal and single breakthrough saturations were analyzed for a range of operating conditions of pressure (100-130 bar) and temperature (313-338 K). The equilibrium data correlated well with the Langmuir isotherm. The adsorption process was successfully modeled by a three-parameter model with comparable fitting parameters for the two types of breakthrough curves.