Selective Removal of Iron from Aqueous Solution using Ion Imprinted Cyanato-Functionalized Silica Gel Sorbents

Abstract

We combined a surface imprinting technique with sol-gel process for preparing a new iron(III)-imprinted cyanato-functionalized silica gel sorbents using (3-cyanatopropyl)triethoxysilane as the functional monomer, and epichlorohydrin as the cross-linking agent for the selective removal of iron(III) from aqueous solution. The iron(III)-imprinted cyanato-functionalized silica gel was characterized by FT-IR spectra and the static adsorption-desorption method. Maximum binding capacity, optimum pH, and equilibrium binding time were found to be 35.6 mg · g−1, pH 3, and 20 min, respectively. The relative selectivity coefficients of ion imprinted cyanato-functionalized silica gel sorbents for Fe(III)/Ni(II), Fe(III)/Co(II), Fe(III)/Cd(II), and Fe(III)/Pb(II) were 8.56, 11.95, 16.96, and 50.71 times greater than the non-imprinted silica gel, respectively. The iron(III)-imprinted cyanato-functionalized silica gel sorbents could be used repeatedly without significantly decreasing their adsorption capacities.