Preparation, characterization and metal sorption studies of a Chrome-Azurol-S-loaded anion-exchange resin

Abstract

Chrome Azurol S (CS) was mobilized on an strongly basic anion-exchange resin (Dowex 2 × 4, in Cl − form) by batch equilibration. The modified resin was stable in acetate buffer solution and in 0.1 M HCl and H 2SO 4, but it was readily degraded with 2–6 M HCl and HNO 3. Retention of Ba(II), Sr(II), Ca(II), Mg(II), Al(III), Cr(III), Zn(II), Fe(III), Ti(IV), Mn(II), Co(II), Ni(II), Cu(II), Cd(II) and Pb(II) was studied using the batch equilibration method. The uptake and recovery yields were determined by using inductively-coupled plasma atomic emission spectroscopy (for Mg, Al, Cr, Ti, Fe, Mn, Ni, Zn, Cu, Cd and Pb) and atomic absorption spectrophotometry (for Ba, Sr, Ca and Co). The optimum pH value was established for performing a selective separation of Al(III) from the other metal ions. The sorption capacities of the CS-loaded resing for Al(III), Cr(III), Mg(II) (at pH 6), Fe(III) (at pH 5) and Ti(IV) (at pH 4) were 14, 2.9, 0.3, 3 and 3.9 μmoles g −1 respectively. On this basis a method for separating Al(III) from other cations was established.