The adsorption behaviour of thorium from aqueous solutions by a composite adsorbent has been investigated by a batch technique. The thorium adsorption on composite adsorbent was studied as a function of initial concentration, pH, shaking time and temperature. The sorption of thorium at the determined optimum conditions follows Langnmir, Freundlich and D-R type isotherms. Langmuir constants Q = 0.04 mmol g(-1) and b = 64.94 L mol(-1) and of D-R parameter X-m = 0.04, beta = 0.79 and of sorption energy E = 0.80 and Freundlich constants 1/n = 3.12 and c(m) = 0.012 mmol g(-1) were evaluated. Thermodynamic parameters such as Delta H and Delta S were found to be 37.32 kJ mol(-1) and 206.17 J mol(-1) K-1, respectively. (C) 2007 Elsevier B.V. All rights reserved.