Origin of tungsten and geochemical controls on its occurrence and mobilization in shallow sediments from Fallon, Nevada, USA
| Autor: | Chad Hobson, Anthony J. Bednar, Harshad Vijay Kulkarni, Ryan Tappero, Paul R. Sheppard, T. Jade Mohajerin, Mark L. Witten, Saugata Datta, Ganga M. Hettiarachchi, Karen H. Johannesson |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Geologic Sediments
Environmental Engineering Health Toxicology and Mutagenesis media_common.quotation_subject 0208 environmental biotechnology chemistry.chemical_element 02 engineering and technology 010501 environmental sciences Tungsten 01 natural sciences Metal Soil Sediment–water interface Environmental Chemistry 0105 earth and related environmental sciences media_common Public Health Environmental and Occupational Health Sediment General Medicine General Chemistry Hydrogen-Ion Concentration Tungsten Compounds Pollution 020801 environmental engineering Speciation X-Ray Absorption Spectroscopy chemistry visual_art Environmental chemistry Soil water Meteoric water visual_art.visual_art_medium Sedimentary rock Adsorption Synchrotrons Nevada |
| Zdroj: | Chemosphere. 260 |
| ISSN: | 1879-1298 |
| Popis: | Tungsten (W) occurrence and speciation was investigated in sediments collected from Fallon, Nevada where previous studies have linked elevated W levels in human body fluids to an unusual cluster of childhood leukemia cases. The speciation of sedimentary W was determined by μ-XRF mapping and μ-XANES. The W content of the analyzed surface sediments ranged between 81 and 25,908 mg/kg, which is significantly higher than the W content in deeper sediments which ranged from 37 to 373 mg/kg at 30 cm depth. The μ-XANES findings reveal that approximately 20–50% of the total W in the shallow sediment occurs in the metallic form (W0); the rest occurs in the oxide form (WVIO3). Because W0 does not occur naturally, its elevated concentrations in surface sediments point toward a local anthropogenic origin. The oxidation of metallic W0 with meteoric waters likely leads to the formation of WVIO3. The chief water-soluble W species was identified as WO42- by chromatographic separation and speciation modeling. These results led us to postulate that W0 particles from a currently unknown but local source(s) is (are) deposited onto the soils and/or surface sediments. The W0 in interaction with meteoric water is oxidized to WVIO3, and as these sediment-water interactions progress, WO42- is formed in the water at pH ∼7. Under pH |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect