Recovery of Cobalt Ions and 60Co Radionuclide from EDTA-Containing Aqueous Solutions

The recovery of cobalt ions and trace amounts of 60Co radionuclide from solutions containing ethylenediaminetetraacetic acid (EDTA) was studied using oxidative destruction, isotope exchange between stable and radioactive cobalt, and displacement of Co(II, III) from EDTA complexes by Fe(III) ions. Oxidative destruction of Co complexes was achieved using solutions of potassium permanganate, hydrogen peroxide with UV irradiation, and ozone. Conditions for maximum Co recovery from solutions, namely, solution pH, temperature, and process duration, were determined. The 98–99% efficiency of 60Co recovery can be achieved using isotope exchange between stable and radioactive cobalt as well as displacement of Co(II, III) from EDTA complexes by Fe(III) ions at 60–90°C.