Mercury Isotope Fractionation during Dark Abiotic Reduction of Hg(II) by Dissolved, Surface-Bound, and Structural Fe(II).

ABSTRACT: Stable mercury (Hg) isotope ratios are an emerging tracer for biogeochemical transformations in environmental systems, but their application requires knowledge of isotopic enrichment factors for individual processes. We investigated Hg isotope fractionation during dark, abiotic reduction of Hg(II) by dissolved iron(Fe)(II), magnetite, and Fe(II) sorbed to boehmite or goethite by analyzing both the reactants and products of laboratory experiments. For homogeneous reduction of Hg(II) by dissolved Fe(II) in continuously purged reactors, the results followed a Rayleigh distillation model with enrichment factors of -2.20 ± 0.16‰ (ε²⁰²Hg) and 0.21 ± 0.02‰ (E¹⁹⁹Hg). In closed system experiments, allowing reequilibration, the initial kinetic fractionation was overprinted by i

SUBMITTER: Schwab L 

PROVIDER: S-EPMC10569049 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature