Activated carbons (ACs) ware prepared from ubame oak activated with ZnCl2 and from coconut shell char activated simultaneously with KOH and CO2. The influences of specific surface area, pore size distribution and surface chemistry on tannic acid and nitrobenzene adsorption were investigated. ZnCl2 activation increased specific surface area to 1700m(2)/g and mesopore volume to 1.1 cm(3)/g, while KOH-CO2 activation increased specific surface area to 1900m(2)/g and micropore volume to 0.7 cm(3)/g. Highly mesoporous AC adsorbed 4 times more tannic acid than commercially available AC (Filtrasorb 400). The amount of tannic acid adsorbed was proportional to the mesopore surface area and mesopore volume, while the amount of nitrobenzene adsorbed increased with the increase in the specific surface area rather than mesopore volume.