Paper Title
Preparation of Amino-Functionalized Silica Gel adsorbents for adsorption of Heavy Metal Ions

Abstract
The preparation of amino-functionalized silica gel adsorbents (APTS-Cr(III)-Si and APTS-Fe(III)-Si) for selective solid-phase extraction of Cr(III) and Fe(III), respectively, from aqueous solutions. The adsorbent materials were prepared by a surface imprinting technique using 3-aminopropyltrimethoxysilane as the surface modifying ligand. The effects of solution pH, sorption time, temperature, and initial metal ion concentration upon adsorption characteristics were investigated. The adsorption isotherms for Langmuir and Freundlich evaluated the adsorption processes. By optimizing the parameters, the synthesized materials could be used successfully for selective removal of trivalent cations from a mixture of cations in dilute aqueous solution. Keywords - Adsorption isotherm, aminofunctionalized silica gel, solid-phase extraction (SPE)