AbstractThe adsorptive capacities of activated carbon for major organic constituents (target compounds) of a wide variety of wastewater were measured in pure water and in actual wastewater samples. Competitive adsorption due to the presence of other orgnic components of total organic carbon of the wastewater (background TOC) reduced carbon capacities for all target compounds in the wastewaters from the respective pure water isotherms. The capacity reduction for a target compound was found to depend on the relative adsorptivity of the target compound versus competing compounds (poorly adsorbed TOC components produced a small reduction in capacity for a more strongly adsorbed target compound), and the fraction of the background TOC attributable to the target compound. Those findings were validated by carbon column adsorption breakthrough data.