Controls on Soluble Pu Concentrations in PuO2/Magnetite Suspensions

Journal Article · Tue Nov 06 04:00:00 EST 2012 · Environmental Science & Technology, 46(21):11610-11617

DOI:https://doi.org/10.1021/es3028956· OSTI ID:1059612

Felmy, Andrew R; Moore, Dean A; Pearce, Carolyn I; Conradson, Steven D; Qafoku, Odeta; Buck, Edgar C; Rosso, Kevin M; Ilton, Eugene S

Time-dependent reduction of PuO2(am) was studied over a range of pH values in the presence of aqueous Fe(II) and magnetite (Fe3O4) nanoparticles. At early time frames (up to 56 days) very little aqueous Pu was mobilized from PuO2(am), even though measured pH and redox potentials, coupled to equilibrium thermodynamic modeling indicated the potential for significant reduction of PuO2(am) to relatively soluble Pu(III). Introduction of Eu(III) or Nd(III) to the suspensions as competitive cations to displace possible sorbed Pu(III) resulted in the release of significant concentrations of aqueous Pu. However, the similarity of aqueous Pu concentrations that resulted from the introduction of Eu(III)/Nd(III) to suspensions with and without magnetite indicated that the Pu was displaced from the PuO2(am), not from magnetite. The fact that soluble forms of Pu can be displaced from the surface of PuO2(am) represents a potential, but previously unidentified, source of Pu to aqueous solution or subsurface groundwaters.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1059612
• Report Number(s): PNNL-SA-83931; 42318; KP1702030
• Journal Information: Environmental Science & Technology, 46(21):11610-11617, Journal Name: Environmental Science & Technology, 46(21):11610-11617
• Country of Publication: United States
• Language: English

Related Subjects

Environmental Molecular Sciences Laboratory