A resin with high adsorption selectivity for Au (III): Preparation, characterization and adsorption properties

In this paper, a novel chelating resin with high adsorption selectivity for Au (III), polystyrene-supported 3-amino-1,2-propanediol (PS-APD), was prepared simply by the reaction of chloromethylated polystyrene with 3-amino-1,2-propanediol. Its structure was characterized by infrared spectroscopy (IR), scanning electron microscope (SEM) and porous structure analysis. The adsorption capabilities of PS-APD for Pb(II), Hg(II), Cu(II), Ni(II) and Au(III) ions were investigated. The results suggested that PS-APD resin possessed much better adsorption capability for Au(III) than for other metal ions. A comparison of the kinetic models on the overall adsorption rate showed that adsorption system was best described by the pseudo second-order kinetics. The adsorption equilibrium data fitted best with the Langmuir isotherm and thermodynamic parameters including ΔG, ΔH and ΔS were calculated. The adsorption mechanism of PS-APD for Au(III) was confirmed by SEM, IR and X-ray photoelectron spectroscopy (XPS), which showed that redox reaction occurred between 3-amino-1,2-propanediol group and Au(III) ions. Adsorption selectivity experiments indicated that PS-APD resin possessed excellent adsorption property to Au(III) ions, offering potential applications in recovery of Au(III) from multi-ionic aqueous systems.

• The synthesized PS-APD resin possessed excellent adsorption selectivity for Au3+.
• The adsorption for Au3+ could be described by the pseudo second-order kinetics.
• Mechanism study showed that Au3+ was reduced to Au(0) by the resin in adsorption.