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Transformation of 2-Line Ferrihydrite to Goethite at Alkaline pH
[Image: see text] The transformation of 2-line ferrihydrite to goethite from supersaturated solutions at alkaline pH ≥ 13.0 was studied using a combination of benchtop and advanced synchrotron techniques such as X-ray diffraction, thermogravimetric analysis, and X-ray absorption spectroscopy. In com...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Chemical Society
2023
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10603785/ https://www.ncbi.nlm.nih.gov/pubmed/37822288 http://dx.doi.org/10.1021/acs.est.3c05260 |
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author | Furcas, Fabio E. Lothenbach, Barbara Mundra, Shishir Borca, Camelia N. Albert, Cristhiana Carine Isgor, O. Burkan Huthwelker, Thomas Angst, Ueli M. |
author_facet | Furcas, Fabio E. Lothenbach, Barbara Mundra, Shishir Borca, Camelia N. Albert, Cristhiana Carine Isgor, O. Burkan Huthwelker, Thomas Angst, Ueli M. |
author_sort | Furcas, Fabio E. |
collection | PubMed |
description | [Image: see text] The transformation of 2-line ferrihydrite to goethite from supersaturated solutions at alkaline pH ≥ 13.0 was studied using a combination of benchtop and advanced synchrotron techniques such as X-ray diffraction, thermogravimetric analysis, and X-ray absorption spectroscopy. In comparison to the transformation rates at acidic to mildly alkaline environments, the half-life, t(1/2), of 2-line ferrihydrite reduces from several months at pH = 2.0, and approximately 15 days at pH = 10.0, to just under 5 h at pH = 14.0. The calculated-first order rate constants of transformation, k, increase exponentially with respect to the pH and follow the progression log(10)k = log(10)k(0) + a·pH(3). Simultaneous monitoring of the aqueous Fe(III) concentration via inductively coupled plasma optical emission spectroscopy demonstrates that (i) goethite likely precipitates from solution and (ii) its formation is rate-limited by the comparatively slow redissolution of 2-line ferrihydrite. The analysis presented can be used to estimate the transformation rate of naturally occurring 2-line ferrihydrite in aqueous electrolytes characteristic to mine and radioactive waste tailings as well as the formation of corrosion products in cementitious pore solutions. |
format | Online Article Text |
id | pubmed-10603785 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | American Chemical Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-106037852023-10-28 Transformation of 2-Line Ferrihydrite to Goethite at Alkaline pH Furcas, Fabio E. Lothenbach, Barbara Mundra, Shishir Borca, Camelia N. Albert, Cristhiana Carine Isgor, O. Burkan Huthwelker, Thomas Angst, Ueli M. Environ Sci Technol [Image: see text] The transformation of 2-line ferrihydrite to goethite from supersaturated solutions at alkaline pH ≥ 13.0 was studied using a combination of benchtop and advanced synchrotron techniques such as X-ray diffraction, thermogravimetric analysis, and X-ray absorption spectroscopy. In comparison to the transformation rates at acidic to mildly alkaline environments, the half-life, t(1/2), of 2-line ferrihydrite reduces from several months at pH = 2.0, and approximately 15 days at pH = 10.0, to just under 5 h at pH = 14.0. The calculated-first order rate constants of transformation, k, increase exponentially with respect to the pH and follow the progression log(10)k = log(10)k(0) + a·pH(3). Simultaneous monitoring of the aqueous Fe(III) concentration via inductively coupled plasma optical emission spectroscopy demonstrates that (i) goethite likely precipitates from solution and (ii) its formation is rate-limited by the comparatively slow redissolution of 2-line ferrihydrite. The analysis presented can be used to estimate the transformation rate of naturally occurring 2-line ferrihydrite in aqueous electrolytes characteristic to mine and radioactive waste tailings as well as the formation of corrosion products in cementitious pore solutions. American Chemical Society 2023-10-12 /pmc/articles/PMC10603785/ /pubmed/37822288 http://dx.doi.org/10.1021/acs.est.3c05260 Text en © 2023 The Authors. Published by American Chemical Society https://creativecommons.org/licenses/by/4.0/Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Furcas, Fabio E. Lothenbach, Barbara Mundra, Shishir Borca, Camelia N. Albert, Cristhiana Carine Isgor, O. Burkan Huthwelker, Thomas Angst, Ueli M. Transformation of 2-Line Ferrihydrite to Goethite at Alkaline pH |
title | Transformation
of 2-Line Ferrihydrite to Goethite
at Alkaline pH |
title_full | Transformation
of 2-Line Ferrihydrite to Goethite
at Alkaline pH |
title_fullStr | Transformation
of 2-Line Ferrihydrite to Goethite
at Alkaline pH |
title_full_unstemmed | Transformation
of 2-Line Ferrihydrite to Goethite
at Alkaline pH |
title_short | Transformation
of 2-Line Ferrihydrite to Goethite
at Alkaline pH |
title_sort | transformation
of 2-line ferrihydrite to goethite
at alkaline ph |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10603785/ https://www.ncbi.nlm.nih.gov/pubmed/37822288 http://dx.doi.org/10.1021/acs.est.3c05260 |
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