Interactions of ions with ionically bonded minerals such as barite (BaSO4) influence the fate and transport of the ions, while the factors that control the sorption of toxic oxyanions on barite remain elusive. In this study, the sorption of arsenate, selenate, and molybdate on the barite (001) surface was examined at pH ~5 using in situ crystal truncation rod analysis, resonant anomalous X-ray reflectivity, and atomic force microscopy. The results show that arsenate and selenate mainly incorporate into the top monolayer of barite, while molybdate primarily adsorbs above the surface. The sorption coverage of arsenate is greater (by ~100%) than that of selenate but similar to that of molybdate. The different incorporation coverages between arsenate and selenate can be explained by their different protonation states at pH 5. The incorporated arsenate may be stabilized by hydrogen bonds between arsenate and oxygen atoms of neighboring sulfate compared to selenate, which exists predominantly in the deprotonated state. The adsorption of molybdate above the surface probably stems from a surface-induced oligomerization, as the anion and the oligomer may be too large for incorporation. Our observation of these different sorption mechanisms demonstrates how the physicochemical properties of the anions control the selective uptake of the toxic metals on the dominant surface of the ionically bonded mineral barite.
Yang, Peng, et al. "Sorption of Arsenate, Selenate, and Molybdate on the Barite (001) Surface." ACS Earth and Space Chemistry, vol. 7, no. 8, Jul. 2023. https://doi.org/10.1021/acsearthspacechem.3c00096
Yang, Peng, Lee, Sang Soo, Fenter, Paul, Bracco, Jacquelyn N., & Stack, Andrew G. (2023). Sorption of Arsenate, Selenate, and Molybdate on the Barite (001) Surface. ACS Earth and Space Chemistry, 7(8). https://doi.org/10.1021/acsearthspacechem.3c00096
Yang, Peng, Lee, Sang Soo, Fenter, Paul, et al., "Sorption of Arsenate, Selenate, and Molybdate on the Barite (001) Surface," ACS Earth and Space Chemistry 7, no. 8 (2023), https://doi.org/10.1021/acsearthspacechem.3c00096
@article{osti_1995651,
author = {Yang, Peng and Lee, Sang Soo and Fenter, Paul and Bracco, Jacquelyn N. and Stack, Andrew G.},
title = {Sorption of Arsenate, Selenate, and Molybdate on the Barite (001) Surface},
annote = {Interactions of ions with ionically bonded minerals such as barite (BaSO4) influence the fate and transport of the ions, while the factors that control the sorption of toxic oxyanions on barite remain elusive. In this study, the sorption of arsenate, selenate, and molybdate on the barite (001) surface was examined at pH ~5 using in situ crystal truncation rod analysis, resonant anomalous X-ray reflectivity, and atomic force microscopy. The results show that arsenate and selenate mainly incorporate into the top monolayer of barite, while molybdate primarily adsorbs above the surface. The sorption coverage of arsenate is greater (by ~100%) than that of selenate but similar to that of molybdate. The different incorporation coverages between arsenate and selenate can be explained by their different protonation states at pH 5. The incorporated arsenate may be stabilized by hydrogen bonds between arsenate and oxygen atoms of neighboring sulfate compared to selenate, which exists predominantly in the deprotonated state. The adsorption of molybdate above the surface probably stems from a surface-induced oligomerization, as the anion and the oligomer may be too large for incorporation. Our observation of these different sorption mechanisms demonstrates how the physicochemical properties of the anions control the selective uptake of the toxic metals on the dominant surface of the ionically bonded mineral barite.},
doi = {10.1021/acsearthspacechem.3c00096},
url = {https://www.osti.gov/biblio/1995651},
journal = {ACS Earth and Space Chemistry},
issn = {ISSN 2472-3452},
number = {8},
volume = {7},
place = {United States},
publisher = {American Chemical Society (ACS)},
year = {2023},
month = {07}}
Argonne National Laboratory (ANL), Argonne, IL (United States); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division (CSGB); USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF)
Grant/Contract Number:
AC02-06CH11357; AC05-00OR22725
OSTI ID:
1995651
Alternate ID(s):
OSTI ID: 2367266
Journal Information:
ACS Earth and Space Chemistry, Journal Name: ACS Earth and Space Chemistry Journal Issue: 8 Vol. 7; ISSN 2472-3452