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Title: Effects of ammonium on uranium partitioning and kaolinite mineral dissolution

Authors:
; ; ;
Publication Date:
Sponsoring Org.:
USDOE Office of Environmental Management (EM)
OSTI Identifier:
1414312
Grant/Contract Number:
EM0000598
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Journal of Environmental Radioactivity
Additional Journal Information:
Journal Volume: 167; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-12-20 01:28:36; Journal ID: ISSN 0265-931X
Publisher:
Elsevier
Country of Publication:
United Kingdom
Language:
English

Citation Formats

Emerson, Hilary P., Di Pietro, Silvina, Katsenovich, Yelena, and Szecsody, Jim. Effects of ammonium on uranium partitioning and kaolinite mineral dissolution. United Kingdom: N. p., 2017. Web. doi:10.1016/j.jenvrad.2016.11.029.
Emerson, Hilary P., Di Pietro, Silvina, Katsenovich, Yelena, & Szecsody, Jim. Effects of ammonium on uranium partitioning and kaolinite mineral dissolution. United Kingdom. doi:10.1016/j.jenvrad.2016.11.029.
Emerson, Hilary P., Di Pietro, Silvina, Katsenovich, Yelena, and Szecsody, Jim. Wed . "Effects of ammonium on uranium partitioning and kaolinite mineral dissolution". United Kingdom. doi:10.1016/j.jenvrad.2016.11.029.
@article{osti_1414312,
title = {Effects of ammonium on uranium partitioning and kaolinite mineral dissolution},
author = {Emerson, Hilary P. and Di Pietro, Silvina and Katsenovich, Yelena and Szecsody, Jim},
abstractNote = {},
doi = {10.1016/j.jenvrad.2016.11.029},
journal = {Journal of Environmental Radioactivity},
number = C,
volume = 167,
place = {United Kingdom},
year = {Wed Feb 01 00:00:00 EST 2017},
month = {Wed Feb 01 00:00:00 EST 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.jenvrad.2016.11.029

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  • The dissolution kinetics of Ni(II) sorbed to kaolinite at pH 7 were examined as a function of initial aqueous Ni(II) concentrations; the local molecular structure of the Ni surface complexes were determined using extended x-ray absorption fine structure (EXAFS) spectroscopy. The dissolution of kaolinite was nonstoichiometric with a preferential release of Si over Al. The dissolution rate, R{sub Si}, increased with an increase in the aqueous concentration of Ni. A rate law was developed representing a fractional-order dissolution reaction with respect to the surface concentration of Ni. Absorption spectra were obtained from kaolinite samples washed with 0.10 M NaNO{sub 3}more » adjusted to pH 3.4 to remove amorphous Al-hydroxide surface deposits or adsorbed Al and from kaolinite that was untreated. For all samples, EXAFS results revealed the presence of multinuclear Ni surface complexes wit h a similar, but not identical, local structural environment to pure crystalline Ni(OH){sub 2}. The Ni-Ni bond distances were shorter (3.06--3.11 {angstrom}) than in Ni(OH){sub 2}(s) (3.13 {angstrom}) and increased with an increase in surface coverage. Additionally, Al was present in all but the highest surface coverage as a second neighbor backscatterer. At the lower surface coverages, Al is present at 2.69 {angstrom}, indicating the formation of a bidentate Ni surface complex. With increased surface coverage, the d(Ni-Al) increases to 2.96 {angstrom}, which is believed to result from a Ni,Al-hydroxide precipitate. No significant structural differences were found between kaolinite pretreatments. Based on these results, a hypothesized mechanism for Ni sorption on kaolinite is proposed.« less
  • No abstract prepared.
  • The rates of dissolution of beryllium metal in aqueous solutions of nitric sulfuric hydrochloric and hydrofluoric acid, and of ammonium fiuoride, were measured, and the relative rates for equimolar concentrations of the acids under similar conditions were found to be HF > H/sub 2/SO/sub 4/ approx equal HCl> HNO/sub 3/. The rate varies with the source and method of fabrication of the metal. Dissolution of beryllium in nitric acid was examined in detail as a function of acid concentration, temperature, surface properties of the metal, and the presence of hydrofluoric acid. (auth)
  • We developed an analytical chemistry method to quantitatively recover microgram quanties of solid uranium oxides from swipe media using ammonium bifluoride (ABF, NH 4HF 2) solution. Recovery of uranium from surrogate swipe media (filter paper) was demonstrated at initial uranium loading levels between 3 and 20 µg filter -1. Moreover, the optimal conditions for extracting U 3O 8 and UO 2 are using 1 % ABF solution and incubating at 80 °C for one hour. The average uranium recoveries are 100 % for U 3O 8, and 90 % for UO 2. Finally, with this method, uranium concentration as lowmore » as 3 µg filter -1 can be recovered for analysis.« less