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 KOH| 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.

► A new iminodiacetic resin product was prepared with a simple and clean route.
► The relationship between metal characteristic and adsorption capacity was found.
► The interaction mechanisms and binding mode of metal ions with resins were studied.