Legacy Mercury Re-emission and Subsurface Migration at Contaminated Sites Constrained by Hg Isotopes and Chemical Speciation.

ABSTRACT: The re-emission and subsurface migration of legacy mercury (Hg) are not well understood due to limited knowledge of the driving processes. To investigate these processes at a decommissioned chlor-alkali plant, we used mercury stable isotopes and chemical speciation analysis. The isotopic composition of volatilized Hg(0) was lighter compared to the bulk total Hg (THg) pool in salt-sludge and adjacent surface soil with mean ε²⁰²Hg_Hg(0)-THg values of -3.29 and -2.35‰, respectively. Hg(0) exhibited dichotomous directions (E¹⁹⁹Hg_Hg(0)-THg = 0.17 and -0.16‰) of mass-independent fractionation (MIF) depending on the substrate from which it was emitted. We suggest that the positive MIF enrichment during Hg(0) re-emission from salt-sludge was overal

SUBMITTER: Zhu W 

PROVIDER: S-EPMC10976890 | biostudies-literature | 2024 Mar

REPOSITORIES: biostudies-literature