EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Silver stable isotopic ratios determined in contaminated soils

Ales Vaněk1, Maria Vaňková2, Martin Mihaljevič2, and Vojtěch Ettler2
Ales Vaněk et al.
  • 1Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Kamýcká 129, 16500 Praha 6, Czech Republic
  • 2Charles University, Faculty of Science, Albertov 6, 12800 Praha 2, Czech Republic

Silver isotopic fractionation(s) during metallurgical processes (or other high-T processes) and its fate in mining- and smelter-affected environments, Ag-contaminated soils/sediments remain entirely unknown. Regarding the Ag-ore processing (roasting/smelting technologies), it can be assumed that, similarly to other isotopic systems (e.g., Tl and Cu), the isotopically lighter Ag (enriched in 107Ag) enters the smelter emissions (fly ash), and isotopically heavier Ag (enriched in 109Ag) remains in the residual metal phase. Our preliminary data from the Ag-contaminated soils around a former primary Ag-smelter at Příbram (Czech Rep.) indicate an apparent variability of ε109Ag within soil profiles. The identified ε109Ag values presented for the forest soil profile (Fig. 1) recorded ~0 in the organic horizon (O), ~0-+1 in the organo-mineral horizons (A1 and A2), and up to +7 in the mineral horizon (B). This finding suggests both the isotopically-lighter Ag fraction present in the topsoil (Fig. 1), as well as enhanced 107Ag release during high-T smelting operations, i.e., relative to geogenic Ag (local ore). However, the question that clearly remains to date is to which degree the alteration/chemical processes in soil could have produced the Ag isotopic fractionation and which type of mechanisms (e.g. Ag(I)→Ag0) could represent the key geochemical controls.

Fig. 1 An example of vertical evolution of Ag isotopic signatures (ε109Ag, relative to the NIST SRM 978a Ag standard) and Ag concentrations in a forest soil profile, ~1 km away from a former primary Ag-smelter (Příbram, Czech Rep.). The Ag isotopic data are assigned an estimated error of ±0.7 ε109Ag (2sigma), which is based on our long-term reproducibility of multiple separate analyses (n = 6) of NIST SRM 2782 (Industrial Sludge) (Vaněk et al., unpublished data).

How to cite: Vaněk, A., Vaňková, M., Mihaljevič, M., and Ettler, V.: Silver stable isotopic ratios determined in contaminated soils, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-2055,, 2023.