Imperial College London
Alternate

ProfessorDominikWeiss

Faculty of Engineering, Department of Earth Science & Engineering

Professor of Environmental Geochemistry
 
 
 
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Contact

 

+44 (0)20 7594 6383d.weiss

 
 
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Location

 

2.39Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@unpublished{Kirby:2020:10.26434/chemrxiv.13032428.v1,
author = {Kirby, M and Sonnenberg, JL and Watson, JS and Weiss, D},
doi = {10.26434/chemrxiv.13032428.v1},
publisher = {American Chemical Society (ACS)},
title = {Prevention of UVI precipitation in alkaline aqueous solutions by the siderophore desferrioxamine B},
url = {http://dx.doi.org/10.26434/chemrxiv.13032428.v1},
year = {2020}
}
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RIS format (EndNote, RefMan)

TY  - UNPB
AB  - In alkaline and saline solutions, uranium VI (UVI) forms uranyl salts, limiting its mobility in leachates released from nuclear waste repositories into groundwater. However, recent experimental and computational work suggested that natural organic molecules widely present in groundwater such as siderophores could potentially prevent solid precipitation because of the formation of stable UVI-siderophore complexes. It is important we assess the impact of siderophores on aqueous UVI chemistry as they could mobilise UVI from contaminated land and radioactive waste storage and disposal sites. Here we test this hypothesis by combining for the first time experimental studies on uranium precipitation in alkaline pH in the presence of desferrioxamine B (DFOB) and electron structure method calculation of uranyl – hydroxamate complexes to assess their stability. Stirred batch experiments containing 0 to 420 µM DFOB, 42 µM UVI and 0.1 M NaCl were conducted at pH 11.5. DFT was employed to explore the relative stability of different UVI-hydroxamate complexes, representative of the local binding mode of DFOB. During the stirred batch experiments, 5%, 11-12%, 41-53%, 95-96% and 100% of UVI passes through the filter membranes (0.2-1 µm pore diameter) after 24 hours when 0, 4.2, 42, 130 and 420 µM DFOB was added to solution. The DFT results suggest one hydroxamate functional group is most likely to complex with UVI with rG calculated as +3 kJ/mol and -9 kJ/mol for [UO2(OH)3(Lmono)]2- and [UO2(OH)2(L)]- respectively. Conversion of the experimentally derived log β (-1.2 ± 0.3) through the equation rG = -2.303RTlogβ provides rG of +7 kJ/mol, similar to the rG of these two complexes. The results of our study confirm that UVI precipitation could be hindered by the formation of a DFOB complex with UVI complexation through a single hydroxamate functional group as a likely mechanism. These results highlight the mobilising effect siderophores
AU  - Kirby,M
AU  - Sonnenberg,JL
AU  - Watson,JS
AU  - Weiss,D
DO  - 10.26434/chemrxiv.13032428.v1
PB  - American Chemical Society (ACS)
PY  - 2020///
TI  - Prevention of UVI precipitation in alkaline aqueous solutions by the siderophore desferrioxamine B
UR  - http://dx.doi.org/10.26434/chemrxiv.13032428.v1
UR  - https://chemrxiv.org/articles/preprint/Prevention_of_UVI_Precipitation_in_Alkaline_Aqueous_Solutions_by_the_Siderophore_Desferrioxamine_B/13032428/1
UR  - http://hdl.handle.net/10044/1/89126
ER  -
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