The biosorption of copper(II) ions from aqueous solution by Tectona grandis L.f. was studied in a batch adsorption system as a function of pH, metal ion concentration, adsorbent concentration and adsorbent size. The biosorption capacities and rates of copper(II) ions onto T grandis L.f. were evaluated. The Langmuir, Freundlich, Redlich-Peterson and Temkin adsorption models were applied to describe the isotherms and isotherm constants. Biosorption isothermal data could be well interpreted by the Langmuir model with maximum adsorption capacity of 15.43 mg/g of copper(II) ion on T grandis L.f. leaves powder. The kinetic experimental data properly correlated with the second-order kinetic model. Various thermodynamic parameters such as Delta G degrees, Delta H degrees, and Delta S degrees were calculated indicating that this system was a spontaneous and exothermic process. (c) 2006 Elsevier B.V. All rights reserved.