Interaction mechanism of aqueous heavy metals onto a newly synthesized IDA-chelating resin: Isotherms, thermodynamics and kinetics

A newly synthesized IDA (iminodiacetic acid)-chelating resin has been obtained and applied to explore the adsorption isotherms, thermodynamics, kinetics and mechanisms for the removal of heavy metal ions from aqueous solutions. Langmuir model can availably fit the isotherm data from which the obtained adsorption capacity follows the order of Cu(II) > Pb(II) > Cd(II). The thermodynamic constants indicate the spontaneous and endothermic nature. Adsorption kinetic data can be satisfactorily described by the pseudo-second-order equation. The first hydrolysis constant [log K(OH)] of metal ion is extremely relevant with the adsorption capacity. The coordinate conformation and interaction mechanism are further explored by Mass Spectrum and Thermo Gravimetric Analysis. (C) 2011 Elsevier B.V. All rights reserved.