Preparation and Metal-Adsorption Properties of the Polymer-Coated Silica Gel Having Iminodiacetate Functional Group

A new adsorbent containing an iminodiacetate group has been prepared by the surface modification of a polymer-coated silica gel. The obtained beads (SG–IDA) are porous and have a high specific surface area (≈350 m2 g−1). The adsorption properties of SG-IDA, including the adsorption capacities, equilibrium distribution coefficients (Kd) and adsorption rates, have been examined for divalent metal ions. The selectivity order of SG–IDA is Cu(II)>Pb(II)>Ni(II)>Zn(II)>>Ca(II)>Mg(II). The SG–IDA shows appreciably high Kd values and rapid kinetics toward the adsorption of heavy metal ions. The concentration of 10 ppb level of metal ions [Cu(II), Zn(II), and Cd(II)] has been demonstrated using the SG-IDA column.