An investigation on the application of CaII-FeII-FeIII magnetic hydrotalcite-like-compounds for the removal of impurities in aqueous systems

Abstract

The main aim of this study is to investigate the feasibility of utilising novel hydrotalcite-like-compounds as ion-exchangers for the removal of anionic impurities from aqueous solution. Hydrotalcite is naturally occurring, rarely found anionic clay. It has a positively charged layered structure consisting of two metal oxide layers and an interlayer of carbonate anions. Hydrotalcites can, therefore, be used as ion-exchangers. However, the carbonate anion is highly selected by natural hydrotalcite, making the ion-exchange capacity for other anions very low. In this study, several synthetic hydrotalcite-like compounds and a magnetic hydrotalcite-like compound samples were prepared in order to remove anionic impurities from waters. The physical structure and chemical properties of these anionic clays were characterised using standard characterisation techniques. The removal capacities of the synthetic products obtained were then investigated. Magnetic hydrotalcite-like-compound, namely, CaII-FeII-FeIII, was proved to be a good ion-exchanger.