In the present work, poly(aryl ether ketone) containing pendant carboxyl groups (PEK-L) is prepared to develop efficient adsorbent for heavy metal ions, Cu(II), Pb(II), Co(II), Ni(II), and Cd(II), from aqueous solution. The property of PEK-L is investigated by using FT-IR and XRD analysis. Effects of pH and contact time, kinetics, adsorption isotherms, and thermodynamics are examined in batch experiments. Kinetic experiments indicate that the processes can be simulated by a pseudo-second-order model. Langmuir. Freundlich, and Tempkin models are applied to analyze the experimental data, and the best interpretation for the experimental data is given by the Freundlich isotherm equation. Thermodynamic parameters, the Gibbs free energy change (Delta G degrees), enthalpy change (Delta H degrees), and entropy change (Delta S degrees), are calculated and show that adsorption of heavy metals on PEK-L is spontaneous and endothermic in nature. The regeneration study indicates that PEK-L can be used repeatedly without significantly changed their adsorption capacities and desorption percentage. (C) 2011 Elsevier B.V. All rights reserved.