Recovery of uranium from aqueous solutions by trioctylamine impregnated polyurethane foam†

Abstract

Polyurethane foams can be used as effective sorbents for the separation and concentration of trace amounts of metal ions. In this work, the sorption and desorption behaviour of uranium(VI) was investigated in dilute uranyl sulfate solutions on an open-cell polyurethane foam impregnated with trioctylamine (TOA) used as an extractant. The parameters affecting uranium extraction such as uranium concentration, ratio of solution volume to foam weight (ml g^–1), pH, concentration, retention time and temperature were studied and optimum conditions were determined. Seven different stripping reactants, (NH₄)₂SO₄, Na₂CO₃, NH₄Cl, NaCl, NaNO₃, NaCl–H₂SO₄, NH₄NO₃–HNO₃, were tested for extracting uranium from the polyurethane foam impregnated with TOA into the aqueous phase again. High stripping efficiences were obtained with 1 M NaCl–0.5 M HCl, 1 M NaCl–0.05 M H₂SO₄ and 0.9 M NH₄NO₃–0.1 M HNO₃ solutions.