Activated carbon has been prepared from molasses, a natural precursor of vegetable origin resulting from the sugar industry in Morocco. The preparation of the activated carbon from the molasses has been carried out by impregnation of the precursor with sulphuric acid, followed by carbonisation at varying conditions (temperature and gas coverage) in order to optimize preparation parameters. The influence of activation conditions was investigated by determination of adsorption capacity of methylene blue and iodine, the BET surface area, and the pore volume of the activated carbon were determined while the micropore volume was determined by the Dubinin-Radushkevich (DR) equation. The activated materials are mainly microporous and reveal the type I isotherm of the Brunauer classification for nitrogen adsorption. The activated carbons properties in this study were found for activation of the mixture (molasses/sulphuric acid) in steam at 750degreesC. The samples obtained in this condition were highly microporous, with high surface area (greater than or equal to 1200 m(2)/g) and the maximum adsorption capacity of metbylene blue and iodine were 435 and 1430 mg/g, respectively. (C) 2004 Elsevier B.V. All rights reserved.