Effects of resuspension on the mobility and chemical speciation of zinc in contaminated sediments

Minwei Xie*, Marco A. Alsina, Jeffrey Yuen, Aaron I. Packman, Jean François Gaillard

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

Identifying and quantifying the processes governing the mobilization of metals during resuspension events is key to assessing long-term metals efflux from sediments and associated ecological impacts. We investigated the effects of sediment resuspension on the mobilization and chemical speciation of zinc in two-week-long batch experiments using metal-contaminated sediments from Lake DePue (IL, USA). Measurements of dissolved zinc and sulfate allowed us to characterize the kinetics of metal sulfide dissolution and the resulting net release of zinc to the aqueous phase. X-ray absorption spectroscopy (XAS) provided direct insights into the chemical speciation of iron and zinc and their dynamic transformations during resuspension. While ZnS rapidly oxidized during resuspension, dissolved zinc increased only after two days of resuspension. We proposed a kinetic model to explain changes in the chemical speciation of zinc during these experiments as constrained by the dissolved species concentrations and chemical speciation as informed by XAS. Only 15% of the zinc mobilized was released to the aqueous phase while the remaining fraction repartitioned the solid phase either as a carbonate precipitate or as a sorbed species. Our results show that zinc sorption onto particle surfaces and reprecipitation of zinc minerals limit zinc solubility during resuspension of metal-sulfide sediments.

Original languageEnglish (US)
Pages (from-to)300-308
Number of pages9
JournalJournal of Hazardous Materials
Volume364
DOIs
StatePublished - Feb 15 2019

Keywords

  • Contaminated sediment
  • Oxidative dissolution
  • Resuspension
  • Scavenge
  • Zinc mobility

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • Waste Management and Disposal
  • Pollution
  • Health, Toxicology and Mutagenesis

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