Granular activated carbons were obtained from grape seeds by pyrolysis at 600 degrees C and subsequent physical activation with CO2 (750-900 degrees C, 1-3 h, 25-74% burn-off). The carbon and ash content increased during the activation, reaching values of 79.0% and 11.4%, respectively. Essentially microporous materials with BET surface areas between 380 and 714m(2)/g were obtained. The performance of the activated carbon in the adsorption of diuron in aqueous phase was studied within the 15-45 degrees C temperature range. Equilibrium data showed that the maximum uptake increased with temperature from 120 to 470 mu mol/g, also evidencing some dependence of the adsorption mechanism on temperature. Data were fitted to five isotherm models [Langmuir, Freundlich, Dubinin-Radushkevich, BET, and GAB (Guggenheim, Anderson, and de Boer)]. Kinetic data were analyzed using first-and second-order rate equations and intraparticle diffusion model. The second-order rate constant values obtained (2.8-13.5 x 10(-3) g/mu mol min) showed that the hollow core morphology of the material favors the adsorption kinetics.