Department of Chemistry University of New Brunswick Fredericton,NB,E3A6E2 (Canada)

摘要

The neptunium(v) cation,NpO_2~+,contains Np in its most stable oxidation state under a wide range of conditions in aqueous media.Because of its low positive charge,NpO_2~+ does not form strong complexes with ligands so it is difficult to separate neptunium from high-level nuclear wastes by using traditional extracting agents that are effective for separating other actinides.Also,the low tendency of NpO_2~+ to undergo hydrolysis and sorption makes it highly mobile in the subsurface,raising concern in the migration of this radio-nuclide in the environment.