Surface-Treated Activated Carbon for Removal of Phenol from Water

摘要

The phenol adsorption characteristics of porous and non-porous carbons and ion-exchange resins were studied for possible removal of organics from drinking water. The nature of the carbon surface was the most important factor in phenol uptake on non-porous carbons at a given equilibrium concentration. Activated carbons which were oxidized with nitric acid, ammonium persulfate, or hydrogen peroxide gave decreased phenol uptake. The phenol adsorption increased however, if the chemisorbed oxygen was removed by heating in nitrogen gas. A greater increase could be realized if the activated carbons were heated in nitrogen gas at 950C to remove oxygen complexes on their surface. The phenol adsorption appeared to increase when more pi-electrons were available on the basal plane surfaces of the crystallites and reduced by oxygen complexes on edge sites. Water is probably attracted more strongly to the edge sites than is phenol. Activated carbons exhibited better phenol adsorption properties than commercial ion-exchange resins.