Soil Chemistry Group, Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich , CH-8092 Zurich, Switzerland.
Environ Sci Technol. 2015 Jan 6;49(1):177-85. doi: 10.1021/es5044358. Epub 2014 Dec 17.
Mass-dependent fractionation (MDF) and mass-independent fractionation (MIF) may cause characteristic isotope signatures of different mercury (Hg) sources and help understand transformation processes at contaminated sites. Here, we present Hg isotope data of sediments collected near industrial pollution sources in Sweden contaminated with elemental liquid Hg (mainly chlor-alkali industry) or phenyl-Hg (paper industry). The sediments exhibited a wide range of total Hg concentrations from 0.86 to 99 μg g(-1), consisting dominantly of organically-bound Hg and smaller amounts of sulfide-bound Hg. The three phenyl-Hg sites showed very similar Hg isotope signatures (MDF δ(202)Hg: -0.2‰ to -0.5‰; MIF Δ(199)Hg: -0.05‰ to -0.10‰). In contrast, the four sites contaminated with elemental Hg displayed much greater variations (δ(202)Hg: -2.1‰ to 0.6‰; Δ(199)Hg: -0.19‰ to 0.03‰) but with distinct ranges for the different sites. Sequential extractions revealed that sulfide-bound Hg was in some samples up to 1‰ heavier in δ(202)Hg than organically-bound Hg. The selectivity of the sequential extraction was tested on standard materials prepared with enriched Hg isotopes, which also allowed assessing isotope exchange between different Hg pools. Our results demonstrate that different industrial pollution sources can be distinguished on the basis of Hg isotope signatures, which may additionally record fractionation processes between different Hg pools in the sediments.
质量依赖分馏 (MDF) 和质量独立分馏 (MIF) 可能导致不同汞 (Hg) 源的特征同位素特征，并有助于了解污染场地的转化过程。在这里，我们展示了瑞典受元素液态 Hg（主要是氯碱工业）或苯基-Hg（造纸工业）污染的工业污染源附近沉积物中 Hg 同位素数据。这些沉积物的总 Hg 浓度范围很广，从 0.86 到 99μg/g，主要由有机结合态 Hg 和少量的硫化物结合态 Hg 组成。三个苯基-Hg 点表现出非常相似的 Hg 同位素特征（MDF δ(202)Hg：-0.2‰至-0.5‰；MIF Δ(199)Hg：-0.05‰至-0.10‰）。相比之下，四个受元素 Hg 污染的点显示出更大的变化（δ(202)Hg：-2.1‰至 0.6‰；Δ(199)Hg：-0.19‰至 0.03‰），但不同点的范围明显不同。连续提取表明，在一些样品中，硫化物结合态 Hg 的 δ(202)Hg 比有机结合态 Hg 重 1‰。连续提取的选择性在用富集 Hg 同位素制备的标准材料上进行了测试，这也允许评估不同 Hg 库之间的同位素交换。我们的结果表明，不同的工业污染源可以根据 Hg 同位素特征来区分，这些特征可能还记录了沉积物中不同 Hg 库之间的分馏过程。
