Stabilization of Plutonium Nano-Colloids by Epitaxial Distortion on Mineral Surfaces

Powell, Brian A.; Dai, Z. R.; Zavarin, Mavrik; Zhao, Pihong; Kersting, Annie B.

doi:10.1021/es1033487

Cited by 96 publications

(123 citation statements)

References 29 publications

Supporting

Mentioning

111

Contrasting

Order By: Relevance

“…High-resolution transmission electron microscopy (HRTEM) imaging (see Fig. S6 in the supplemental material) indicated that the nanocrystalline Pu(IV)O 2 precipitates have a crystallite dimension of 2 to 3 nm, similar to those previously observed under similar solution conditions (13,42,43). The main features of the corresponding electron diffraction patterns match the face-centered cubic (fcc) Pu(IV)O 2 crystal structure (see Fig.…”

Section: Cellular Pu Sorption and Reduction Pseudomonas Sp Eps-1wsupporting

confidence: 77%

“…NMR analysis was performed to identify functional groups associated with the EPS. The NMR solid-state 13 C{ 1 H} CP-MAS spectrum includes distinctive peaks corresponding to carboxylic acid and acetyl functional groups likely from peptides (see Fig. S5 in the supplemental material).…”

Section: Cellular Pu Sorption and Reduction Pseudomonas Sp Eps-1wmentioning

confidence: 99%

“…At high concentrations (Ͼ10 Ϫ8 Ϯ 1 M), Pu(IV) hydrolyzes to form Pu(IV) oxide precipitates (4,12). This can lead to the formation of intrinsic Pu(IV)O 2 colloids and/or surface precipitates (13).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Interactions of Plutonium with Pseudomonas sp. Strain EPS-1W and Its Extracellular Polymeric Substances

Boggs

Jiao

Dai

et al. 2016

Appl Environ Microbiol

Self Cite

View full text Add to dashboard Cite

Safe and effective nuclear waste disposal, as well as accidental radionuclide releases, necessitates our understanding of the fate of radionuclides in the environment, including their interaction with microorganisms. We examined the sorption of Pu(IV) and Pu(V) to Pseudomonas sp. strain EPS-1W, an aerobic bacterium isolated from plutonium (Pu)-contaminated groundwater collected in the United States at the Nevada National Security Site (NNSS) in Nevada. We compared Pu sorption to cells with and without bound extracellular polymeric substances (EPS). Wild-type cells with intact EPS sorbed Pu(V) more effectively than cells with EPS removed. In contrast, cells with and without EPS showed the same sorption affinity for Pu(IV). In vitro experiments with extracted EPS revealed rapid reduction of Pu(V) to Pu(IV). Transmission electron microscopy indicated that 2-to 3-nm nanocrystalline Pu(IV)O 2 formed on cells equilibrated with high concentrations of Pu(IV) but not Pu(V). Thus, EPS, while facilitating Pu(V) reduction, inhibit the formation of nanocrystalline Pu(IV) precipitates. IMPORTANCEOur results indicate that EPS are an effective reductant for Pu(V) and sorbent for Pu(IV) and may impact Pu redox cycling and mobility in the environment. Additionally, the resulting Pu morphology associated with EPS will depend on the concentration and initial Pu oxidation state. While our results are not directly applicable to the Pu transport situation at the NNSS, the results suggest that, in general, stationary microorganisms and biofilms will tend to limit the migration of Pu and provide an important Pu retardation mechanism in the environment. In a broader sense, our results, along with a growing body of literature, highlight the important role of microorganisms as producers of redox-active organic ligands and therefore as modulators of radionuclide redox transformations and complexation in the subsurface.T he civil production of nuclear energy and military production of nuclear materials have resulted in an estimated worldwide inventory of over 2,000 metric tons of plutonium (Pu) (1). This inventory continues to increase at a rate of approximately 70 metric tons per year as a result of global nuclear energy production (2). Due to its long half-life (24,100 years for 239 Pu) and high radiotoxicity (3), Pu is an important driver in public health risk assessments for nuclear waste repositories and radiologically contaminated sites. However, predicting how Pu behaves in the environment and ultimately calculating its human health risk are limited by our understanding of the dominant biogeochemical processes controlling its behavior.The behavior of Pu in the environment is strongly dependent on its oxidation state and concentration. Among all the actinides, Pu has one of the most complex chemical, redox, and surface sorption behaviors. At low concentrations, Pu can exist as aqueous species in the III, IV, V, and/or VI oxidation states, all of which have different solubilities (4), mineral sorption affinities (5-7), and hence...

show abstract

Section: Cellular Pu Sorption and Reduction Pseudomonas Sp Eps-1wsupporting

confidence: 77%

Section: Cellular Pu Sorption and Reduction Pseudomonas Sp Eps-1wmentioning

confidence: 99%

See 1 more Smart Citation

Interactions of Plutonium with Pseudomonas sp. Strain EPS-1W and Its Extracellular Polymeric Substances

Boggs

Jiao

Dai

et al. 2016

Appl Environ Microbiol

Self Cite

View full text Add to dashboard Cite

show abstract

“…This does not necessarily mean that the tetravalent ions are immobilized. Depending on the groundwater chemistry and the mineral and organic species present in the local environment, both U(IV) and Pu(IV) can be incorporated into aqueous colloids [5,27,28] or U(IV) may be con-3 verted into U(VI) by weathering [29]. In the case of bulk melt glass, the redox state of the material may impact the redox state of groundwater flowing through the test location [30,31], affecting, in turn, the solubility and transport properties of other materials.…”

Section: Introductionmentioning

confidence: 99%

Chemical speciation of U, Fe, and Pu in melt glass from nuclear weapons testing

Pacold

Lukens

Booth

et al. 2016

Journal of Applied Physics

View full text Add to dashboard Cite

Nuclear weapons testing generates large volumes of glassy material that influence the transport of dispersed actinides in the environment and may carry information on the composition of the detonated device. We determine the oxidation state of U and Fe (which is known to buffer the oxidation state of actinide elements and to affect the redox state of groundwater) in samples of melt glass collected from three U.S. nuclear weapons tests. For selected samples, we also determine the coordination geometry of U and Fe, and we report the oxidation state of Pu from one melt glass sample. We find significant variations among the melt glass samples, and in particular, find a clear deviation in one sample from the expected buffering effect of Fe(II)/Fe(III) on the oxidation state of uranium. In the first direct measurement of Pu oxidation state in a nuclear test melt glass, we obtain a result consistent with existing literature that proposes Pu is primarily present as Pu(IV) in post-detonation material. In addition, our measurements imply that highly mobile U(VI) may be produced in significant quantities when melt glass is quenched rapidly following a nuclear detonation, though these products may remain immobile in the vitrified matrices. The observed differences in chemical state among the three samples show that redox conditions can vary dramatically across different nuclear test conditions. The local soil composition, associated device materials, and the rate of quenching are all likely to affect the final redox state of the glass. The resulting variations in glass chemistry are significant for understanding and interpreting debris chemistry, and the later environmental mobility of dispersed material.

show abstract

“…This formulation was not observed in nano-clusters characterized by Soderholm et al (2010). In their recent work, Powell et al (2011) examined the behavior of Pu(IV) surface precipitates and colloids in the presence of goethite and quartz. Transmission electron microscopy (TEM) was used to characterize the morphology of Pu associated with these mineral phases.…”

mentioning

confidence: 99%

Sorption Behavior and Morphology of Plutonium in the Presence of Goethite at 25 and 80C

Zavarin¹,

Zhao²,

Dai³

et al. 2012

View full text Add to dashboard Cite

Stabilization of Plutonium Nano-Colloids by Epitaxial Distortion on Mineral Surfaces

Cited by 96 publications

References 29 publications

Interactions of Plutonium with Pseudomonas sp. Strain EPS-1W and Its Extracellular Polymeric Substances

Interactions of Plutonium with Pseudomonas sp. Strain EPS-1W and Its Extracellular Polymeric Substances

Chemical speciation of U, Fe, and Pu in melt glass from nuclear weapons testing

Sorption Behavior and Morphology of Plutonium in the Presence of Goethite at 25 and 80C

Contact Info

Product

Resources

About