Uranium Isotope Fractionation during the Anoxic Mobilization of Noncrystalline U(IV) by Ligand Complexation.
Uranium Isotope Fractionation during the Anoxic Mobilization of Noncrystalline U(IV) by Ligand Complexation.
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配体络合非晶 U(IV) 缺氧迁移过程中的铀同位素分馏
DOI：
10.1021/acs.est.0c08623
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发表时间：
--
影响因子：
11.4
通讯作者：
Stefan
中科院分区：
文献类型：
--
作者：
Roebbert;Yvonne;Rosendahl;Chris Daniel;Ashley;Schippers;Bernier- Latmani;Rizlan;Stefan
铀(U)同位素被建议作为追踪铀还原的工具。然而，主要在近地表环境中形成的非晶U（IV）可以在缺氧条件下使用配体络合和再活化。这可能引起额外的铀同位素分馏，并改变铀还原产生的特征。在这里，我们研究了通过配体络合和相关的U同位素分馏来调动非晶U（IV）的效果。通过shewanella oneidensisMR-1还原U(VI) （400 μM）产生非晶U(IV)，随后在批量实验中与EDTA （1 mM）、柠檬酸盐（1 mM）或碳酸氢盐（500 mM）进行动员。与所有被研究的配体的络合都导致U（IV）的显著动员，并导致238u在动员部分的富集（EDTA δ238U = 0.4-0.7‰，柠檬酸盐δ238U = 0.3‰，碳酸氢盐δ238U = 0.2-0.3‰）。对于碳酸氢盐活化，瑞利法是最合适的同位素分馏模型，分馏因子α为1.00026-1.00036。EDTA的活化可以用平衡同位素分馏（α: 1.00039-1.00049）来模拟。结果表明，缺氧条件下铀同位素分馏与铀（IV）动员相关，在将铀同位素应用于修复监测或作为古氧化还原代理时需要考虑。
Uranium (U) isotopes are suggested as a tool to trace U reduction. However, noncrystalline U(IV), formed predominantly in near-surface environments, may be complexed and remobilized using ligands under anoxic conditions. This may cause additional U isotope fractionation and alter the signatures generated by U reduction. Here, we investigate the efficacy of noncrystalline U(IV) mobilization by ligand complexation and the associated U isotope fractionation. Noncrystalline U(IV) was produced via the reduction of U(VI) (400 μM) byShewanella oneidensisMR-1 and was subsequently mobilized with EDTA (1 mM), citrate (1 mM), or bicarbonate (500 mM) in batch experiments. Complexation with all investigated ligands resulted in significant mobilization of U(IV) and led to an enrichment of238U in the mobilized fraction (δ238U = 0.4–0.7 ‰ for EDTA; 0.3 ‰ for citrate; 0.2–0.3 ‰ for bicarbonate). For mobilization with bicarbonate, a Rayleigh approach was the most suitable isotope fractionation model, yielding a fractionation factor α of 1.00026–1.00036. Mobilization with EDTA could be modeled with equilibrium isotope fractionation (α: 1.00039–1.00049). The results show that U isotope fractionation associated with U(IV) mobilization under anoxic conditions is significant and needs to be considered when applying U isotopes in remediation monitoring or as a paleo-redox proxy.
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影响因子：
1.8
作者：
S. Richter;R. Eykens;H. Kühn;Y. Aregbe;A. Verbruggen;S. Weyer
通讯作者：
S. Richter;R. Eykens;H. Kühn;Y. Aregbe;A. Verbruggen;S. Weyer
影响因子：
11.4
作者：
Basu, Anirban;Brown, Shaun T.;Maher, Kate
通讯作者：
Maher, Kate
影响因子：
11.4
作者：
Brennecka, Gregory A.;Wasylenki, Laura E.;Anbar, Ariel D.
通讯作者：
Anbar, Ariel D.
DOI：
10.1063/1.2992616
发表时间：
2008-10
期刊：
The Journal of chemical physics
影响因子：
--
作者：
M. Abe;Tatsuya Suzuki;Y. Fujii;M. Hada;K. Hirao
通讯作者：
M. Abe;Tatsuya Suzuki;Y. Fujii;M. Hada;K. Hirao
影响因子：
2.3
作者：
Yoshinori Suzuki;Kazuya Tanaka;N. Kozai;T. Ohnuki
通讯作者：
Yoshinori Suzuki;Kazuya Tanaka;N. Kozai;T. Ohnuki