Uranium(V) incorporation mechanisms and stability in Fe(II)/Fe(III) (oxyhydr)oxides

Hananah E. Roberts, Katherine Morris, Gareth T. W. Law, J. Frederick W. Mosselmans, Pieter Bots, Kristina Kvashnina, Samuel Shaw

Research output: Contribution to journalArticle

24 Citations (Scopus)
11 Downloads (Pure)

Abstract

Understanding interactions between radionuclides and mineral phases underpins site environmental clean-up and waste management in the nuclear industry. Transport and fate of radionuclides in many subsurface environments are controlled by adsorption, redox and mineral incorporation processes. Interactions of iron (oxyhydr)oxides with uranium have been extensively studied due to the abundance of uranium as an environmental contaminant and ubiquity of iron (oxyhydr)oxides in engineered and natural environments. Despite this, detailed mechanistic information regarding the incorporation of uranium into Fe(II) bearing magnetite and green rust is sparse. Here, we present a co-precipitation study where U(VI) was reacted with environmentally relevant iron(II/III) (oxyhydr)oxide mineral phases. Based on diffraction, microscopic, dissolution and spectroscopic evidence, we show the reduction of U(VI) to U(V) and stabilisation of the U(V) by incorporation within the near-surface and bulk of the particles during co-precipitation with iron (oxyhydr)oxides. U(V) was stable in both magnetite and green rust structures and incorporated via substitution for octahedrally coordinated Fe in a uranate-like coordination environment. As the Fe(II)/Fe(III) ratio increased, a proportion of U(IV) was also precipitated as surface associated UO2. These novel observations have significant implications for the behaviour of uranium within engineered and natural environments.
Original languageEnglish
Pages (from-to)421-426
Number of pages6
JournalEnvironmental Science and Technology Letters
Volume4
Issue number10
Early online date8 Sep 2017
DOIs
Publication statusPublished - 19 Oct 2017

Fingerprint

Uranium
Iron oxides
Oxides
Magnetite
Coprecipitation
Radioisotopes
Bearings (structural)
Minerals
Oxide minerals
Nuclear industry
Waste management
Dissolution
Substitution reactions
Stabilization
Diffraction
Impurities
Iron
Adsorption

Keywords

  • radionuclides
  • environmental cleanup
  • waste management
  • nuclear industry

Cite this

Roberts, Hananah E. ; Morris, Katherine ; Law, Gareth T. W. ; Mosselmans, J. Frederick W. ; Bots, Pieter ; Kvashnina, Kristina ; Shaw, Samuel. / Uranium(V) incorporation mechanisms and stability in Fe(II)/Fe(III) (oxyhydr)oxides. In: Environmental Science and Technology Letters. 2017 ; Vol. 4, No. 10. pp. 421-426.
@article{ad1e217c43ab4b8a976897c9f2ce63f8,
title = "Uranium(V) incorporation mechanisms and stability in Fe(II)/Fe(III) (oxyhydr)oxides",
abstract = "Understanding interactions between radionuclides and mineral phases underpins site environmental clean-up and waste management in the nuclear industry. Transport and fate of radionuclides in many subsurface environments are controlled by adsorption, redox and mineral incorporation processes. Interactions of iron (oxyhydr)oxides with uranium have been extensively studied due to the abundance of uranium as an environmental contaminant and ubiquity of iron (oxyhydr)oxides in engineered and natural environments. Despite this, detailed mechanistic information regarding the incorporation of uranium into Fe(II) bearing magnetite and green rust is sparse. Here, we present a co-precipitation study where U(VI) was reacted with environmentally relevant iron(II/III) (oxyhydr)oxide mineral phases. Based on diffraction, microscopic, dissolution and spectroscopic evidence, we show the reduction of U(VI) to U(V) and stabilisation of the U(V) by incorporation within the near-surface and bulk of the particles during co-precipitation with iron (oxyhydr)oxides. U(V) was stable in both magnetite and green rust structures and incorporated via substitution for octahedrally coordinated Fe in a uranate-like coordination environment. As the Fe(II)/Fe(III) ratio increased, a proportion of U(IV) was also precipitated as surface associated UO2. These novel observations have significant implications for the behaviour of uranium within engineered and natural environments.",
keywords = "radionuclides, environmental cleanup, waste management, nuclear industry",
author = "Roberts, {Hananah E.} and Katherine Morris and Law, {Gareth T. W.} and Mosselmans, {J. Frederick W.} and Pieter Bots and Kristina Kvashnina and Samuel Shaw",
year = "2017",
month = "10",
day = "19",
doi = "10.1021/acs.estlett.7b00348",
language = "English",
volume = "4",
pages = "421--426",
journal = "Environmental Science and Technology Letters",
issn = "2328-8930",
number = "10",

}

Uranium(V) incorporation mechanisms and stability in Fe(II)/Fe(III) (oxyhydr)oxides. / Roberts, Hananah E.; Morris, Katherine; Law, Gareth T. W.; Mosselmans, J. Frederick W.; Bots, Pieter; Kvashnina, Kristina; Shaw, Samuel.

In: Environmental Science and Technology Letters, Vol. 4, No. 10, 19.10.2017, p. 421-426.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Uranium(V) incorporation mechanisms and stability in Fe(II)/Fe(III) (oxyhydr)oxides

AU - Roberts, Hananah E.

AU - Morris, Katherine

AU - Law, Gareth T. W.

AU - Mosselmans, J. Frederick W.

AU - Bots, Pieter

AU - Kvashnina, Kristina

AU - Shaw, Samuel

PY - 2017/10/19

Y1 - 2017/10/19

N2 - Understanding interactions between radionuclides and mineral phases underpins site environmental clean-up and waste management in the nuclear industry. Transport and fate of radionuclides in many subsurface environments are controlled by adsorption, redox and mineral incorporation processes. Interactions of iron (oxyhydr)oxides with uranium have been extensively studied due to the abundance of uranium as an environmental contaminant and ubiquity of iron (oxyhydr)oxides in engineered and natural environments. Despite this, detailed mechanistic information regarding the incorporation of uranium into Fe(II) bearing magnetite and green rust is sparse. Here, we present a co-precipitation study where U(VI) was reacted with environmentally relevant iron(II/III) (oxyhydr)oxide mineral phases. Based on diffraction, microscopic, dissolution and spectroscopic evidence, we show the reduction of U(VI) to U(V) and stabilisation of the U(V) by incorporation within the near-surface and bulk of the particles during co-precipitation with iron (oxyhydr)oxides. U(V) was stable in both magnetite and green rust structures and incorporated via substitution for octahedrally coordinated Fe in a uranate-like coordination environment. As the Fe(II)/Fe(III) ratio increased, a proportion of U(IV) was also precipitated as surface associated UO2. These novel observations have significant implications for the behaviour of uranium within engineered and natural environments.

AB - Understanding interactions between radionuclides and mineral phases underpins site environmental clean-up and waste management in the nuclear industry. Transport and fate of radionuclides in many subsurface environments are controlled by adsorption, redox and mineral incorporation processes. Interactions of iron (oxyhydr)oxides with uranium have been extensively studied due to the abundance of uranium as an environmental contaminant and ubiquity of iron (oxyhydr)oxides in engineered and natural environments. Despite this, detailed mechanistic information regarding the incorporation of uranium into Fe(II) bearing magnetite and green rust is sparse. Here, we present a co-precipitation study where U(VI) was reacted with environmentally relevant iron(II/III) (oxyhydr)oxide mineral phases. Based on diffraction, microscopic, dissolution and spectroscopic evidence, we show the reduction of U(VI) to U(V) and stabilisation of the U(V) by incorporation within the near-surface and bulk of the particles during co-precipitation with iron (oxyhydr)oxides. U(V) was stable in both magnetite and green rust structures and incorporated via substitution for octahedrally coordinated Fe in a uranate-like coordination environment. As the Fe(II)/Fe(III) ratio increased, a proportion of U(IV) was also precipitated as surface associated UO2. These novel observations have significant implications for the behaviour of uranium within engineered and natural environments.

KW - radionuclides

KW - environmental cleanup

KW - waste management

KW - nuclear industry

U2 - 10.1021/acs.estlett.7b00348

DO - 10.1021/acs.estlett.7b00348

M3 - Article

VL - 4

SP - 421

EP - 426

JO - Environmental Science and Technology Letters

JF - Environmental Science and Technology Letters

SN - 2328-8930

IS - 10

ER -