Selective sorption of uranyl and ferric ions on phenolic-type resins of glyoxal-bis-2-hydroxyanil and salicylaldehyde-ethylenediimine

Abstract

Glyoxal-bis-2-hydroxyanil (GHA) has been reacted with formaldehyde and salicylaldehyde-ethylenediimine (SED) with a mixture of resorcinol and formaldehyde, to prepare the phenolic-type resins Poly(GHA) and Poly(SED), which have high sorption capacities for UO 2 2+ (455 and 334 mg U/g dry weight of resin) and for Fe 3+ (245 and 77 mg Fe/g dry weight of resin). The sorption of UO 2 2+ is maximum in weakly acidic or neutral solutions (pH 6–7), falling rapidly both at lower and higher pH, while the uptake of Fe 3+, sorbed mainly as anionic complexes, is high even in strongly acidic HCl and H 2SO 4 media. Among other common transition metal ions, only Cu(II) has significant sorption on Poly(GHA) and Poly(SED), the saturation capacities being 61 and 31 mg Cu/g dry weight of resin, respectively. Considering the sea water concentrations of transition metal ions as the equilibrium concentrations in the presence of the resin, concentration factors have been calculated for UO 2 2+ (as tricarbonate complex) and common transition metal ions, yielding the highest values for UO 2 2+ with 68 and 39 L sea water/g dry weight of resin on Poly(GHA) and Poly(SED), respectively.