and intraparticle diffusion seem significant in the rate-controlling step, but the pseudo-second-order chemical reaction kinetics provide the best correlation for the experimental data. The enthalpy change for the process was found to be exothermic, and the δS θ values were calculated to be negative for the adsorption of Pb(II) and Cd(II) ions onto CCS. Negative free enthalpy change values indicated that the adsorption process was feasible. The studies of the kinetics, isotherm, and thermodynamics indicated that the adsorption of CCS was more effective for Pb(II) ions than for Cd(II) ions.