IEC 120 |
| Ivan Laszak1, Artem V. Gelis2, Mark Jensen1, and Kenneth L. Nash1. (1) Chemistry Division, Argonne National Laboratory, 9700 South Cass Avenue, bldg 200, Argonne, IL 60439, (2) Chemical Technology Division, Argonne National Laboratory, Argonne, IL 60439 |
| The inorganic speciation of Pu(VI) in alkaline media (hydroxide concentration range from 0.0025 to 0.800M) was studied by Visible-NIR and NMR-13C spectroscopy. The experiments were conducted starting from the tris-carbonato species PuO2(CO3)3-4, and progressively increasing hydroxide concentration under inert atmosphere, with simultaneous spectrum recording. The data were analyzed using the deconvolution software Specfit32 in parallel with the NMR-13C spectra. The results show that four Pu(VI) complexes appear to be formed, besides PuO2(CO3)3-4, depending on the chemical conditions reached at the end of the experiments: PuO2(CO3)(OH)22-, PuO2(CO3)(OH)33-, PuO2(OH)3- and PuO2(OH)42-. For each of these were determined their main Visible-NIR spectroscopic features (wavelength of maximum absorption, associated coefficient of absortivity and full width at half maximum) along with the corresponding stability constants extrapolated at zero ionic strength. Speciation calculations are performed to define the limits under which these species are important. Work performed under the auspices of the Environmental Management Science Program, U.S. Department of Energy under contract number W-31-109-ENG-38 |
|
Advanced Technologies for Decontaminating and Managing Radioactive Wastes
1:00 PM-5:00 PM, Tuesday, March 25, 2003 Convention Center -- Room 394, Oral
Division of Industrial and Engineering Chemistry |