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Xu J, Bland GD, Gu Y, Ziaei H, Xiao X, Deonarine A, Reible D, Bireta P, Hoelen TP, Lowry GV. Impacts of Sediment Particle Grain Size and Mercury Speciation on Mercury Bioavailability Potential. Environ Sci Technol 2021; 55:12393-12402. [PMID: 34505768 DOI: 10.1021/acs.est.1c03572] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Particle-specific properties, including size and chemical speciation, affect the reactivity of mercury (Hg) in natural systems (e.g., dissolution or methylation). Here, terrestrial, river, and marine sediments were size-fractionated and characterized to correlate particle-specific properties of Hg-bearing solids with their bioavailability potential and measured biomethylation. Marine sediments contained ∼20-50% of the total Hg in the <0.5 μm size fraction, compared to only 0.5 and 3.0% in this size fraction for terrestrial and river sediments, respectively. X-ray absorption spectroscopy (XAS) analysis indicated that metacinnabar (β-HgS) was the main mercury species in a marine sediment, whereas organic Hg-thiol (Hg(SR)2) was the main mercury species in a terrestrial sediment. Single-particle inductively coupled plasma time-of-flight mass spectrometry analysis of the marine sediment suggests that half of the Hg in the <0.5 μm size fraction existed as individual nanoparticles, which were β-HgS based on XAS analyses. Glutathione-extractable mercury was higher for samples containing Hg(SR)2 species than β-HgS species and correlated well with the amount of Hg biomethylation. This particle-scale understanding of how Hg speciation and particle size affect mercury bioavailability potential helps explain the heterogeneity in Hg methylation in natural sediments.
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Affiliation(s)
- Jiang Xu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
- Center for Environmental Implications of Nanotechnology, Pittsburgh, Pennsylvania 15213, United States
| | - Garret D Bland
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
- Center for Environmental Implications of Nanotechnology, Pittsburgh, Pennsylvania 15213, United States
| | - Yuan Gu
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Hasti Ziaei
- Department of Civil, Environmental, & Construction Engineering, Texas Tech University, Lubbock, Texas 79409, United States
| | - Xiaoyue Xiao
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Amrika Deonarine
- Department of Civil, Environmental, & Construction Engineering, Texas Tech University, Lubbock, Texas 79409, United States
| | - Danny Reible
- Department of Civil, Environmental, & Construction Engineering, Texas Tech University, Lubbock, Texas 79409, United States
| | - Paul Bireta
- Chevron Technical Center (a Chevron U.S.A. Inc. Division), San Ramon, California 94583, United States
| | - Thomas P Hoelen
- Chevron Technical Center (a Chevron U.S.A. Inc. Division), San Ramon, California 94583, United States
| | - Gregory V Lowry
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
- Center for Environmental Implications of Nanotechnology, Pittsburgh, Pennsylvania 15213, United States
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