Task-specific ionic liquid impregnated resin for zinc(II) recovery from chloride solutions

Abstract

The impregnation of Amberlite XAD-4 with the selected task-specific ionic liquid enables the preparation of an efficient EIR for Zn(II) recovery from HCl and NaCl solutions. It was shown that the Amberlite XAD-4 impregnated with 1-propyl-3-undecanoylpyridinium chloride was very efficient and the Zn(II) uptake increased with the 1-propyl-3-undecanoylpyridinium chloride content in the resin, as well as with HCl and NaCl concentration, and temperature of the process. The speciation studies indicated that Zn(II) was removed as neutral and anionic chloro-complexes according to the ion pair and ion exchange mechanism. Adsorption isotherms were also studied to understand the mechanism of the removal and used models confirmed that the binding of Zn(II) was mainly controlled by chemisorption, with the maximum sorption capacity 210 mg Zn(II) per gram of the resin. Zn(II) can also be easily desorbed using water and diluted chloride solutions, without loss in the adsorption capacity.