Selective Separation of Fe(III), Cd(II), and Ni(II) from Dilute Solutions Using Solvent-Impregnated Resins

The aim of this work was to study the separation of Cd(II), Fe(III), and Ni(II) from dilute solutions using solvent-impregnated resins. The separation was performed using Amberlite XAD-2 impregnated with the extractants Cyanex 272 and Cyanex 302.The influence of pH on the extraction of each metal was determined, first using liquid/liquid extraction and then using solvent-impregnated resins. Extraction isotherms and kinetics were then studied at the selected pH. Results showed that Fe(III) can be extracted from aqueous solutions at pH 2 using Amberlite XAD-2 impregnated with Cyanex 272, Cd(II) extracted at pH 2 using Amberlite XAD-2/Cyanex 302, and Ni(II) extracted at pH 8 using Amberlite XAD-2/Cyanex 302. Loaded resins can be regenerated, and the metal ions can be recovered selectively. Two fixed-bed columns arranged in-series (Amberlite XAD-2 impregnated with Cyanex 301 and Cyanex 302, respectively) were successfully used for the separation and recovery of these three metal ions from multi-component solutions.