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 language | English (US) |
|---|---|
| Pages (from-to) | 300-308 |
| Number of pages | 9 |
| Journal | Journal of Hazardous Materials |
| Volume | 364 |
| DOIs | |
| State | Published - Feb 15 2019 |
Funding
This research was supported by the Strategic Environmental Research and Development Program (ER-1745) and by the National Natural Science Foundation of China (Grant 21707113 ). We thank Dr. Qing Ma for his technical assistance while performing XAS experiments at the APS. Portions of this work were performed at the DND-CAT Synchrotron Research Center located at Sector 5 of the APS. DND-CAT is supported by the E.I. DuPont de Nemours & Co. , The Dow Chemical Company , the U.S. National Science Foundation through Grant DMR-9304725 , and the State of Illinois through the Department of Commerce and the Board of Higher Education Grant IBHE HECA NWU 96 . This research was supported by the Strategic Environmental Research and Development Program (ER-1745) and by the National Natural Science Foundation of China (Grant 21707113). We thank Dr. Qing Ma for his technical assistance while performing XAS experiments at the APS. Portions of this work were performed at the DND-CAT Synchrotron Research Center located at Sector 5 of the APS. DND-CAT is supported by the E.I. DuPont de Nemours & Co., The Dow Chemical Company, the U.S. National Science Foundation through Grant DMR-9304725, and the State of Illinois through the Department of Commerce and the Board of Higher Education Grant IBHE HECA NWU 96.
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