Adsorption of Iron(III), Gold(III), Gallium(III), Thallium(III) and Antimony(V) on Amberlite XAD and Chelex 100 Resins from Hydrochloric Acid Solution

Abstract

Adsorption behavior was investigated for five metals that form chloro-complexes on Amberlite XAD-4, XAD-7, XAD-8 and chelating resin Chelex 100 from hydrochloric acid solution. XAAD-7, XAD-8 and Chelex 100 adsorbed efficiently the metals; suitable hydrochloric acid concentrations were _??_6M for iron(III), _??_0.1M for gold(III), _??_5M for gallium(III), 0.1-8M for thallium(III) and 6-11M for antimony(V) (M=mol l^-1). The metals were also adsorbed considerably on XAD-4 and Unicellex A {only iron(III) and antimony(V) were examined}. The extent of adsorption decreased with an increase in the concentration of the metals and the adsorption isotherms were found to be langmuir type. The capacities of XAD-7, XAD-8 and Chelex 100 for the metals were in the range 0.4-0.9mmol g^-1 (weight after drying at 60°C). When hydrochloric acid is used to elute iron from Chelex 100, 1M hydrochloric acid is suitable but 10M is not. Possible adsorption mechanisms were discussed briefly.