在黑暗中的同位素分离 通过溶解,表面结合和结构性铁减少Hg (II)
Lorenz Schwab1,2,3, Niklas Gallati1, Sofie M Reiter1
1Department of Environmental Geosciences, Centre for Microbiology and Environmental Systems Science, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria.
Environmental science & technology
|September 25, 2023
概括
这项研究量化了 (Hg) 同位素在铁的非生物降解过程中的分离. 结果显示,不同的铁还原途径具有不同的同位素特征,有助于环境的追踪.
科学领域:
- 环境科学 环境科学
- 地质化学 地质化学
- 同位素地球化学 同位素地球化学
背景情况:
- 稳定的 (Hg) 同位素比为环境生物地球化学过程的有价值的标记物.
- 了解Hg同位素分离因子对于应用这些标记物至关重要.
研究的目的:
- 通过各种铁 (Fe) 物种对Hg的非生物降解过程中的Hg同位素分离进行研究.
- 为了确定特定的Hg(II) 减少路径的丰富系数.
主要方法:
- 实验室实验涉及Hg (II) 通过溶解的Fe (II),磁铁和Fe (II) 吸收到矿物表面进行降解.
- 分析反应剂和产品中的同位素比率.
- 雷利蒸和线性平衡模型的应用.
主要成果:
- 在开放系统中溶解的Fe (II) 显示出动力分离 (ε202Hg = -2.20 ± 0.16‰).
- 用溶解Fe(II) 进行的封闭系统实验显示出平衡分离 (ε202Hg = -2.44 ± 0.17‰).
- 通过磁铁的异质减少导致了较小的分化 (ε202Hg = -1.38 ± 0.07‰).
- 观察到的质量独立分离 (MIF) 与理论预测一致.
结论:
- 在开放系统中,通过溶解的Fe降解产生了独特的动力MIF签名.
- 结合质量依赖和质量独立的分离数据,可以区分非生物降解途径与微生物或光化学途径.
- 这项研究增强了对特定环境过程的同位素丰富因子的数据库.
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