Removal of Pb(II) from aqueous solution using ethylene diamine tetra acetic acid-Zr(IV) iodate composite cation exchanger: Kinetics, isotherms and thermodynamic studies

•EDTA-Zr(IV) iodate cation exchanger was synthesized by sol–gel method.•EDTA-Zr(IV) iodate was found to be highly selective for Pb(II) metal.•Uptake rate of Pb2+ was fast and equilibrium established within 50 min.•Practical efficiency of the EDTA-Zr(IV) iodate was explored in the synthetic mixture.

EDTA-Zr(IV) iodate was prepared via the incorporation of aqueous solution of EDTA into the inorganic precipitate of Zr(IV) iodate. Distribution coefficient values for different metals showed that EDTA-Zr(IV) iodate had the highest adsorption capacity for Pb(II). The practical applicability of EDTA-Zr(IV) iodate was explored by separating Pb(II) metal from a synthetic mixture of metal ions. Dependence of adsorption on contact time, pH of the solution, exchanger dose and temperature was studied to achieve the optimum conditions. Kinetic studies showed better applicability for pseudo-second-order model. Thermodynamic parameters viz. – entropy change, enthalpy change and Gibb's free energy change were also calculated.

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