Abstract
| Original language | English |
|---|---|
| Pages (from-to) | 13139-13148 |
| Number of pages | 10 |
| Journal | Environmental Science and Technology |
| Volume | 49 |
| Issue number | 22 |
| Early online date | 21 Oct 2015 |
| DOIs | |
| Publication status | Published - 17 Nov 2015 |
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Keywords
- nuclear facilities
- radiotoxicity
- microbial reduction
- carbonation
- nanoparticulate
- biotite
- chlorite
- minerals
- X-ray absorption spectroscopy
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Redox interactions of Tc(VII), U(VI), and Np(V) with microbially reduced biotite and chlorite. / Brookshaw, Diana R.; Pattrick, Richard A.D.; Bots, Pieter; Law, Gareth T. W.; Lloyd, Jonathan R.; Mosselmans, J. Fredrick W.; Vaughan, David J.; Dardenne, Kathy; Morris, Katherine.
In: Environmental Science and Technology , Vol. 49, No. 22, 17.11.2015, p. 13139-13148.Research output: Contribution to journal › Article
TY - JOUR
T1 - Redox interactions of Tc(VII), U(VI), and Np(V) with microbially reduced biotite and chlorite
AU - Brookshaw, Diana R.
AU - Pattrick, Richard A.D.
AU - Bots, Pieter
AU - Law, Gareth T. W.
AU - Lloyd, Jonathan R.
AU - Mosselmans, J. Fredrick W.
AU - Vaughan, David J.
AU - Dardenne, Kathy
AU - Morris, Katherine
PY - 2015/11/17
Y1 - 2015/11/17
N2 - Technetium, uranium, and neptunium are contaminants that cause concern at nuclear facilities due to their long half-life, environmental mobility, and radiotoxicity. Here we investigate the impact of microbial reduction of Fe(III) in biotite and chlorite and the role that this has in enhancing mineral reactivity toward soluble TcO4 -, UO2 2+, and NpO2 +. When reacted with unaltered biotite and chlorite, significant sorption of U(VI) occurred in low carbonate (0.2 mM) buffer, while U(VI), Tc(VII), and Np(V) showed low reactivity in high carbonate (30 mM) buffer. On reaction with the microbially reduced minerals, all radionuclides were removed from solution with U(VI) reactivity influenced by carbonate. Analysis by X-ray absorption spectroscopy (XAS) confirmed reductive precipitation to poorly soluble U(IV) in low carbonate conditions and both Tc(VII) and Np(V) in high carbonate buffer were also fully reduced to poorly soluble Tc(IV) and Np(IV) phases. U(VI) reduction was inhibited under high carbonate conditions. Furthermore, EXAFS analysis suggested that in the reaction products, Tc(IV) was associated with Fe, Np(IV) formed nanoparticulate NpO2, and U(IV) formed nanoparticulate UO2 in chlorite and was associated with silica in biotite. Overall, microbial reduction of the Fe(III) associated with biotite and chlorite primed the minerals for reductive scavenging of radionuclides: this has clear implications for the fate of radionuclides in the environment.
AB - Technetium, uranium, and neptunium are contaminants that cause concern at nuclear facilities due to their long half-life, environmental mobility, and radiotoxicity. Here we investigate the impact of microbial reduction of Fe(III) in biotite and chlorite and the role that this has in enhancing mineral reactivity toward soluble TcO4 -, UO2 2+, and NpO2 +. When reacted with unaltered biotite and chlorite, significant sorption of U(VI) occurred in low carbonate (0.2 mM) buffer, while U(VI), Tc(VII), and Np(V) showed low reactivity in high carbonate (30 mM) buffer. On reaction with the microbially reduced minerals, all radionuclides were removed from solution with U(VI) reactivity influenced by carbonate. Analysis by X-ray absorption spectroscopy (XAS) confirmed reductive precipitation to poorly soluble U(IV) in low carbonate conditions and both Tc(VII) and Np(V) in high carbonate buffer were also fully reduced to poorly soluble Tc(IV) and Np(IV) phases. U(VI) reduction was inhibited under high carbonate conditions. Furthermore, EXAFS analysis suggested that in the reaction products, Tc(IV) was associated with Fe, Np(IV) formed nanoparticulate NpO2, and U(IV) formed nanoparticulate UO2 in chlorite and was associated with silica in biotite. Overall, microbial reduction of the Fe(III) associated with biotite and chlorite primed the minerals for reductive scavenging of radionuclides: this has clear implications for the fate of radionuclides in the environment.
KW - nuclear facilities
KW - radiotoxicity
KW - microbial reduction
KW - carbonation
KW - nanoparticulate
KW - biotite
KW - chlorite
KW - minerals
KW - X-ray absorption spectroscopy
U2 - 10.1021/acs.est.5b03463
DO - 10.1021/acs.est.5b03463
M3 - Article
VL - 49
SP - 13139
EP - 13148
JO - Environmental Science and Technology
JF - Environmental Science and Technology
SN - 0013-936X
IS - 22
ER -