Surface-Treated Activated Carbon for Removal of Phenol from Water

Abstract

Adsorption of phenol from dilute solutions has been studied on porous and nonporous carbons, as well as on ion-exchange resins. At a given equilibrium concentration, uptake of phenol on nonporous carbons per unit area is determined by the nature of the carbon surface. Phenol uptake on porous activated carbons decreases sharply upon surface oxidation. However, progressive elimination of chemisorbed oxygen from the oxidized carbon upon heat treatment at increasing temperatures in N₂ increases the phenol adsorption capacity. The capacity is further enhanced if following heat treatment in N₂ at 950 ddot]C the samples are reacted with H₂ at 300 ddot]C. The mechanism of phenol adsorption on carbons has been discussed. Activated carbons are more effective adsorbents for phenol than commercial ion-exchange resins.