Granular activated carbon was used for the removal of 18-crown-6 from aqueous solution by adsorption. The influence of two experimental parameters, initial 18-crown-6 concentration and temperature, on the adsorption kinetics was evaluated. The kinetics data obtained were modeled by pseudo-first-order and pseudo-second-order models, respectively. The process of adsorption follows a pseudo-second-order rate model. The most important result of the present study is that the correlation coefficient is not a sufficient criterion for selection of a kinetic model, and therefore several criteria are suggested for its selection. (c) 2006 Elsevier Inc. All rights reserved.