Phenol Adsorption from Dilute Aqueous Solutions by Carbons

Abstract

The adsorption of phenol from dilute aqueous solutions by seven activated carbons and one non-porous carbon black is reported. It is confirmed that the equilibrium can be described by a modified Dubinin-Radushkevich-Kaganer equation, with exponent n = 4 and Es = (1.03 ± 0.18)Eo. At low equilibrium concentrations, phenol and its derivatives are adsorbed as monolayers by both non-porous and porous carbons. However, water is preferentially adsorbed on the oxygen-containing surface complexes, which reduces the area available to phenol and its derivatives by 71 m2 per mmol of surface oxygen.