Roethlin Remo L, Meister Aurélia C E, Gilli Adrian, Lennartz Sinikka T, Amsler Helen Eri, Dittrich Maria, Wehrli Bernhard, Schönbächler Maria, Dubois Nathalie
Department of Surface Waters Research and Management, Eawag, Überlandstrasse 133, Dübendorf, 8600 Switzerland.
Geological Institute, Department of Earth and Planetary Sciences, ETH Zurich, Sonneggstrasse 5, Zurich, 8092 Switzerland.
Swiss J Geosci. 2024;117(1):22. doi: 10.1186/s00015-024-00471-6. Epub 2024 Dec 24.
Industrial activities of a silk dyeing factory in Thalwil, on the shore of Lake Zurich, Switzerland, caused extreme Sn contamination of lake sediments. In this study, we determine the contamination source, spread, and age using a multiproxy approach. We used X-ray fluorescence spectroscopy (XRF) core scanning and further geochemical analyses to assess the contamination spreading and thickness in the sedimentary column. We found elevated Sn levels throughout sediments of Lake Zurich, ranging from 177 in front of the former silk factory to 0.05 at the southeast end (background: ca. 0.006 ). The rapid concentration drop away from the shore suggests quick precipitation of a sparingly soluble inorganic Sn compound, which is confirmed by Scanning Electron Microscope Imaging in tandem with Energy-dispersive XRF spectroscopy (SEM-EDX) data. The Sn XRF profile of a varved core indicates a contamination onset in the early 1890s, a maximum around 1900, and a gradual decrease to low levels in the 1940s. High Sn concentrations in turbidite layers from the deep basin indicate that mass movements physically remobilised Sn. However, in stable conditions, in-situ porewater measurements (conc. < 0.5 ) using dialyse plates show little Sn remobilisation into the lake water (0.05 ). The low remobilisation, reducing conditions, and high sulphide contents in the contaminated layers suggest that Sn is firmly bound to the sediments. Combined with the low toxicity of Sn, we conclude that the Sn contamination poses no threat to lake biota or drinking water production.
The online version contains supplementary material available at 10.1186/s00015-024-00471-6.
瑞士苏黎世湖岸边塔尔维尔一家丝绸印染厂的工业活动导致湖泊沉积物受到严重的锡污染。在本研究中，我们采用多指标方法确定污染来源、扩散情况和年代。我们使用X射线荧光光谱（XRF）岩芯扫描及进一步的地球化学分析来评估沉积柱中的污染扩散和厚度。我们发现苏黎世湖沉积物中的锡含量普遍升高，从前丝绸厂前的177μg/g到东南端的0.05μg/g（背景值：约0.006μg/g）。离岸边迅速下降的浓度表明一种微溶无机锡化合物快速沉淀，扫描电子显微镜成像与能量色散XRF光谱（SEM - EDX）数据证实了这一点。一个纹层岩芯的锡XRF剖面表明污染始于19世纪90年代初，1900年左右达到峰值，20世纪40年代逐渐降至低水平。深盆浊积层中的高锡浓度表明大规模运动使锡发生了物理再迁移。然而，在稳定条件下，使用透析板进行的原位孔隙水测量（浓度<0.5μg/g）显示很少有锡再迁移到湖水中（0.05μg/g）。污染层中低再迁移率、还原条件和高硫化物含量表明锡与沉积物紧密结合。结合锡的低毒性，我们得出结论，锡污染对湖泊生物群或饮用水生产不构成威胁。
在线版本包含可在10.1186/s00015 - 024 - 00471 - 6获取的补充材料。
