The as-grown CNTs and graphitized CNTs were used as adsorbents to remove 1,2-dichlorobenzene from water. The experiments demonstrate that it takes only 40 min for CNTs to attain equilibrium and the adsorption capacity of as-grown and graphitized CNTs is 30.8 and 28.7 mg/g, respectively, from a 20 mg/l solution. CNTs can be used as adsorbents in a wide pH range of 3-10. Thermodynamic calculations indicate that the adsorption reaction is spontaneous with a high affinity and the adsorption is an endothermic reaction. (C) 2003 Elsevier Science B.V. All rights reserved.