Adsorption of heavy metals from aqueous media onto synthetic resins

The author studied the preparation of chelating resins with amine, thio and amine/mercaptan and iminoacetic acid functionalities based on Glycidyl methacrylate¿divinylbenzene resin. The resins showed a powerful adsorption behavior towards transition and non-transition metal ions such as Au(III), Hg(II), Ca(II), Mg(II), Cd(II), Zn(II)...etc. The mechanism of interaction between metal ions and resin active sites were clarified. The nature of interaction between the metal ion and the resin was found to be dependent upon the acidity of the medium as well as the type of the conjugate anion.This interaction was found to proceed via complex formation or ion exchange mechanism. The resin samples loaded with metal ions can be regenerated using different mineral acids or acidified thiourea without significant activity loss.