Design of a strong-base anion exchanger and its adsorption and elution behavior for rhenium(VII)

Abstract

A novel strong-base anion exchanger (PS-g-4VP-IE) is prepared by γ-irradiation-induced grafting of 4-vinyl pyridine onto polystyrene microspheres, followed by a quaternization process. The effects of absorbed dose and monomer concentration on grafting yield and quaternization time on conversion ratio were investigated in order to obtain optimum synthesis conditions. The FTIR and XPS results effectively manifest the successful synthesis of PS-g-4VP-IE. Furthermore, the effect of solution acidity on adsorption efficiency, adsorption kinetics and adsorption isotherm were investigated in batch-wise experiments. The results reveal that the adsorption towards perrhenate (ReO₄⁻) not only has rather fast adsorption kinetics, but also matches well with the Langmuir isotherm model. Thus, its theoretical maximum adsorption capacity is deduced to be 252 mg g⁻¹, while that of the couterpart is 247 mg g⁻¹ in column experiments. The concentrated elution peak shows the potential application of PS-g-4VP-IE in concentrating ReO₄⁻.