XANES Investigation of Phosphate Sorption in Single and Binary Systems of Iron and Aluminum Oxide Minerals
| Autor: | James D. Martin, Nidhi Khare, Dean Hesterberg |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Boehmite
Goethite Inorganic chemistry Ferric Compounds Phosphates chemistry.chemical_compound Ferrihydrite Adsorption Aluminum Oxide Chemical Precipitation Environmental Chemistry Minerals Spectrum Analysis X-Rays Sorption General Chemistry Phosphate XANES chemistry visual_art Ferritins visual_art.visual_art_medium Phosphate minerals Iron Compounds Nuclear chemistry |
| Zdroj: | Environmental Science & Technology. 39:2152-2160 |
| ISSN: | 1520-5851 0013-936X |
| DOI: | 10.1021/es049237b |
| Popis: | Phosphate sorption on Fe- and Al-oxide minerals helps regulate the solubility and mobility of P in the environment. The objective of this study was to characterize phosphate adsorption and precipitation in single and binary systems of Fe- and Al-oxide minerals. Varying concentrations of phosphate were reacted for 42 h in aqueous suspensions containing goethite, ferrihydrite, boehmite, or noncrystalline (non-xl) Al-hydroxide, and in 1:1 (by mass) mixed-mineral suspensions of goethite/boehmite and ferrihydrite/ non-xl Al-hydroxide at pH 6 and 22 degrees C. X-ray absorption near edge structure (XANES) spectroscopy was used to detect precipitated phosphate and distinguish PO4 associated with Fe(III) versus Al(III) in mixed-mineral systems. Changes in the full width at half-maximum height (fwhm) in the white-line peak in P K-XANES spectra provided evidence for precipitation in Al-oxide single-mineral systems, but not in goethite or ferrihydrite systems. Similarly, adsorption isotherms and XANES data showed evidence for precipitation in goethite/boehmite mixtures, suggesting that mineral interactive effects on PO4 sorption were minimal. However, sorption in ferrihydrite/non-xl Al-hydroxide systems and a lack of XANES evidence for precipitation indicated that mineral interactions inhibited precipitation in these binary mixtures. |
| Databáze: | OpenAIRE |
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