Thanks Lisa. I know the Inorganic  like metals does not adsorb onto the surface of carbon. but I need the Organic pollutant. Among the alcohols, diols, strong acids and bases family, is there any pollutant? Do you have experience with carbon adsorption? Also if the efficiency is about the 50%  is good for me because i want to improved efficiency of pure activated carbon.

The pore size of the activated carbon you are using should match the size of the molecules you want to adsorb. Phenols will be trapped in micropores, which is OK, but some dyes will not because much too big. In this case, the adsorption performances are significantly increased by using mesoporous carbons. You also have to consider surface chemistry, wich is at least as important as porosity for adsorption processes in the liquid phase. At similar pore sizes, for instance basic activated carbons will be far more efficient for trapping acidic species (e.g. phenols in N-doped activated carbons). Similarly, organic compounds of mercury will be adsorbed in S-doped activated carbons. So you have to select the kind of activated crabon you need for trapping organic compounds from water, as not all general-purpose aactivated carbons will work.

Alain

The adsorption depends up on the pore size of the material as well as that of the carbon when it matches then adsorption takes place.Th water soluble compds. like dyes, sugar , low mol. wt. amino acids are not adsorbed on activated carbon.