CaltechAUTHORS
  A Caltech Library Service

Time Scales for Sorption−Desorption and Surface Precipitation of Uranyl on Goethite

Giammar, Daniel E. and Hering, Janet G. (2001) Time Scales for Sorption−Desorption and Surface Precipitation of Uranyl on Goethite. Environmental Science and Technology, 35 (16). pp. 3332-3337. ISSN 0013-936X. https://resolver.caltech.edu/CaltechAUTHORS:20170315-130320168

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20170315-130320168

Abstract

The sorption of uranium on mineral surfaces can significantly influence the fate and transport of uranium contamination in soils and groundwater. The rates of uranium adsorption and desorption on a synthetic goethite have been evaluated in batch experiments conducted at constant pH of 6 and ionic strength of 0.1 M. Adsorption and desorption reactions following the perturbation of initial states were complete within minutes to hours. Surface−solution exchange rates as measured by an isotope exchange method occur on an even shorter time scale. Although the uranium desorption rate was unaffected by the aging of uranium−goethite suspensions, the aging process appears to remove a portion of adsorbed uranium from a readily exchangeable pool. The distinction between sorption control and precipitation control of the dissolved uranium concentration was also investigated. In heterogeneous nucleation experiments, the dissolved uranium concentration was ultimately controlled by the solubility of a precipitated uranyl oxide hydrate. The X-ray diffraction pattern of the precipitate is characteristic of the mineral schoepite. Precipitation is kinetically hindered at low degrees of supersaturation. In one experiment, metastable sorption controlled dissolved uranium concentrations in excess of the solubility limit for more than 30 d.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1021/es0019981DOIArticle
http://pubs.acs.org/doi/abs/10.1021/es0019981PublisherArticle
Additional Information:© 2001 American Chemical Society. Received for review December 20, 2000. Revised manuscript received May 30, 2001. Accepted May 30, 2001. Publication Date (Web): July 12, 2001. Lee Silver generously provided the ^(235)U spike. Ken Farley provided time and assistance in the operation of his laboratory's Finnigan Element ICP-MS. Funding was provided to D.G. through a National Science Foundation Graduate Fellowship.
Funders:
Funding AgencyGrant Number
NSF Graduate Research FellowshipUNSPECIFIED
Issue or Number:16
Record Number:CaltechAUTHORS:20170315-130320168
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20170315-130320168
Official Citation:Time Scales for Sorption−Desorption and Surface Precipitation of Uranyl on Goethite Daniel E. Giammar and Janet G. Hering Environmental Science & Technology 2001 35 (16), 3332-3337 DOI: 10.1021/es0019981
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:75149
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:16 Mar 2017 17:11
Last Modified:03 Oct 2019 16:47

Repository Staff Only: item control page