CALCIUM ADSORPTION AT THE RUTILE-WATER INTERFACE: A POTENTIOMETRIC STUDY IN NACL MEDIA TO 250°C - INTERFACIAL AND INTERSPECIES PROCESSES
- 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 | Ridley M.K. | |
dc.contributor.author | Machesky M.L. | |
dc.contributor.author | Wesolowski D.J. | |
dc.contributor.author | Palmer D.A. | |
dc.date.accessioned | 2021-01-09T05:51:38Z | |
dc.date.available | 2021-01-09T05:51:38Z | |
dc.date.issued | 1999 | |
dc.identifier | https://elibrary.ru/item.asp?id=184846 | |
dc.identifier.citation | Geochimica et Cosmochimica Acta, 1999, , 19, 3087-3096 | |
dc.identifier.issn | 0016-7037 | |
dc.identifier.uri | https://repository.geologyscience.ru/handle/123456789/22512 | |
dc.description.abstract | Calcium adsorption by rutile was studied potentiometrically from 25 to 250°C, at ionic strengths of 0.03 and 0.30 m in NaCl media, using two complementary experimental methodologies. In the first, net proton adsorption in the presence and absence of Ca2+ was monitored, and in the second, samples were periodically withdrawn during the course of a titration to determine Ca2+ adsorption directly. These experiments revealed that Ca2+adsorption systematically increased with temperature relative to the pH of zero net proton charge in NaCl media alone (pHznpc(NaCl) - pH). That is, as temperature increased, Ca2+ adsorption commenced at progressively more positive pHznpc(NaCl) - pH values. Increasing ionic strength from 0.03 to 0.30 m NaCl suppressed Ca2+ adsorption at all temperatures as a result of either increased competition from Na+ or greater complexation of Ca2+ by Cl-. Finally, there was no apparent trend in the proton stoichiometric ratios (moles H+ released / moles Ca2+ adsorbed) with increasing temperature. This suggests that the electrostatic and/or chemical processes involved in Ca2+ adsorption do not change greatly with increasing temperature. Favorable entropic effects, related to the increasing ease of releasing Ca2+ waters of hydration, are believed to be primarily responsible for the increase in adsorption with temperature. | |
dc.title | CALCIUM ADSORPTION AT THE RUTILE-WATER INTERFACE: A POTENTIOMETRIC STUDY IN NACL MEDIA TO 250°C - INTERFACIAL AND INTERSPECIES PROCESSES | |
dc.type | Статья |
Files in this item
Files | Size | Format | View |
---|---|---|---|
There are no files associated with this item. |
This item appears in the following Collection(s)
-
ELibrary
Метаданные публикаций с сайта https://www.elibrary.ru