A DONNAN POTENTIAL MODEL FOR METAL SORPTION ONTO BACILLUS SUBTILIS
- DSpace Home
- →
- Геология России
- →
- ELibrary
- →
- View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.
dc.contributor.author | Yee N. | |
dc.contributor.author | Fowle D.A. | |
dc.contributor.author | Ferris F.G. | |
dc.date.accessioned | 2022-03-21T07:44:19Z | |
dc.date.available | 2022-03-21T07:44:19Z | |
dc.date.issued | 2004 | |
dc.identifier | https://www.elibrary.ru/item.asp?id=12090479 | |
dc.identifier.citation | Geochimica et Cosmochimica Acta, 2004, 68, 18, 3657-3664 | |
dc.identifier.issn | 0016-7037 | |
dc.identifier.uri | https://repository.geologyscience.ru/handle/123456789/36537 | |
dc.description.abstract | In this study, we conducted electrophoretic mobility, potentiometric titration, and metal sorption experiments to investigate the surface charge characteristics of Bacillus subtilis and the electrostatic interactions between metal cations and the cell surface electric field. Electrophoretic mobility experiments performed as a function of pH and ionic strength show an isoelectric point of pH 2.4, with the magnitude of the electrokinetic potential increasing with increasing pH, and decreasing with increasing ionic strength. Potentiometric titration experiments conducted from pH 2.4 to 9 yield an average surface charge excess of 1.6 μmol/mg (dry mass). Corresponding cell wall charge density values were used to calculate the Donnan potential (ΨDON) as function of pH and ionic strength. Metal sorption experiments conducted with Ca(II), Sr(II), and Ba(II) exhibit strong ionic strength dependence, suggesting that the metal ions are bound to the bacterial cell wall via an outer-sphere complexation mechanism. Intrinsic metal sorption constants for the sorption reactions were determined by correcting the apparent sorption constant with the Boltzmann factor. A 1:2 metal-ligand stoichiometry provides the best fit to the experimental data with log K2int values of 5.9 ± 0.3, 6.0 ± 0.2, 6.2 ± 0.2 for Ca(II), Sr(II), and Ba(II) respectively. Electrophoretic mobility measurements of cells sorbed with Ca(II), Sr(II), and Ba(II) support the 1:2 sorption stoichiometry. These results indicate that electrical potential parameters derived from the Donnan model can be applied to predict metal binding onto bacterial surfaces over a wide range of pH and ionic strength conditions. | |
dc.title | A DONNAN POTENTIAL MODEL FOR METAL SORPTION ONTO BACILLUS SUBTILIS | |
dc.type | Статья |
Files in this item
This item appears in the following Collection(s)
-
ELibrary
Метаданные публикаций с сайта https://www.elibrary.ru