Rice husk and sugarcane bagasse were chemically impregnated with ZnCl2 and carbonized at 700 degrees C in a large-scale rotary furnace. The activated carbons (ACs) obtained had BET surface area of 811 and 864 m(2)/g, respectively, and were essentially microporous. The adsorption of arsenic, humic acid, phenol and a municipal solid waste landfill leachate was examined. Both ACs showed the best adsorption behaviour towards phenol, removing around 80% at the equilibrium time of 4 h. The adsorption isotherms for arsenic and humic acid were also favourable, although the maximum loadings achieved were lower than that of phenol. Finally. the rice husk AC showed 60% and 70% removal efficiency for colour and COD, respectively, when tested on a landfill leachate. (C) 2008 Elsevier B.V. All rights reserved.