MCM-41 has been synthesized and modified in order to graft amine groups on its surface. The modified NH2-MCM-41 adsorbent was characterized by using XRD, SEM, surface area and porosity analyzer, and FT-IR. This characterized adsorbent was investigated for uranium adsorption using the batch method. The central composite design (CCD) combined with the response surface methodology (RSM) was selected to determine the effects of parameters and their interactions for the removal of UO22+ ions. The optimum values of the parameters determined were 4.2 for the initial pH, 60 degrees C for the temperature, 90 mg L-1 for the initial concentration and 173 min for the shaking time using the response surface methodology. Delta H degrees and Delta S degrees were calculated from the slope and the intercept of plots of In K-d versus 1/T. The isotherm models, Langmuir, Freundlich, Dubinin-Radushkevich (D-R) have been studied to explain the adsorption characteristics. (C) 2010 Elsevier B.V. All rights reserved.