Surface analytical studies of feldspar surface reaction with U(VI)

E S Chardon; D Bosbach; F R Livens; I C Lyon; C Marquardt; J Romer; D Schild; P L Wincott; R A Wogelius; D J Vaughan

doi:10.1016/j.gca.2007.06.013

Surface analytical studies of feldspar surface reaction with U(VI)

E S Chardon, D Bosbach, F R Livens, I C Lyon, C Marquardt, J Romer, D Schild, P L Wincott, R A Wogelius, D J Vaughan

Research output: Chapter in Book/Conference proceeding › Conference contribution › peer-review

Abstract

Feldspar minerals are thermodynamically unstable in the
near-surface environment and their surfaces are well known to
react readily with aqueous solutions, leading to incongruent
dissolution at low pH values, but congruent dissolution at
neutral and high pH values. Interactions with mineral surfaces
are an important control on the environmental transport of
trace elements and detrital feldspars are abundant in soils and
sediments.
The interaction of U(VI) ions with the feldspar surface has
been studied. Sorption experiments with uranyl ion (UO2
2+) at
pH 2, 6 and 10 were carried out and measurable uptake,
generally through surface complex formation, was only found
at pH 6 and 10. Reacted surfaces were analysed by X-ray
photoelectron spectroscopy and secondary ion mass
spectrometry. At pH 6 and at an initial U(VI) concentration
above 21.0 μM, precipitation of a surface phase was observed
by atomic force and scanning electron microscopies, and this
was identified as becquerelite (Ca[UO2)3O2(OH)3]2.8H2O) by
grazing incidence X-ray diffraction. Secondary ion mass
spectrometry showed diffusion of uranium into the altered
surface layer.

Original language	English
Title of host publication	GEOCHIMICA ET COSMOCHIMICA ACTA
Publisher	Elsevier BV
Pages	A160-A160
Number of pages	1
Volume	71
Edition	15 Suppl.1
ISBN (Print)	0016-7037
DOIs	https://doi.org/10.1016/j.gca.2007.06.013
Publication status	Published - Aug 2007
Event	17th Annual V M Goldschmidt Conference - Cologne, Germany Duration: 19 Aug 2007 → 24 Aug 2007 https://www.geochemsoc.org/publications/geochemicalnews/gn134jan08/17thvmgoldschmidtconferenc

Conference

Conference	17th Annual V M Goldschmidt Conference
Country/Territory	Germany
City	Cologne
Period	19/08/07 → 24/08/07
Internet address	https://www.geochemsoc.org/publications/geochemicalnews/gn134jan08/17thvmgoldschmidtconferenc

Keywords

Geochemistry & Geophysics

Access to Document

10.1016/j.gca.2007.06.013

Cite this

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title = "Surface analytical studies of feldspar surface reaction with U(VI)",

abstract = "Feldspar minerals are thermodynamically unstable in thenear-surface environment and their surfaces are well known toreact readily with aqueous solutions, leading to incongruentdissolution at low pH values, but congruent dissolution atneutral and high pH values. Interactions with mineral surfacesare an important control on the environmental transport oftrace elements and detrital feldspars are abundant in soils andsediments.The interaction of U(VI) ions with the feldspar surface hasbeen studied. Sorption experiments with uranyl ion (UO22+) atpH 2, 6 and 10 were carried out and measurable uptake,generally through surface complex formation, was only foundat pH 6 and 10. Reacted surfaces were analysed by X-rayphotoelectron spectroscopy and secondary ion massspectrometry. At pH 6 and at an initial U(VI) concentrationabove 21.0 μM, precipitation of a surface phase was observedby atomic force and scanning electron microscopies, and thiswas identified as becquerelite (Ca[UO2)3O2(OH)3]2.8H2O) bygrazing incidence X-ray diffraction. Secondary ion massspectrometry showed diffusion of uranium into the alteredsurface layer. ",

keywords = "Geochemistry & Geophysics",

author = "Chardon, {E S} and D Bosbach and Livens, {F R} and Lyon, {I C} and C Marquardt and J Romer and D Schild and Wincott, {P L} and Wogelius, {R A} and Vaughan, {D J}",

note = "Chardon, E. S. Bosbach, D. Livens, F. R. Lyon, I. C. Marquardt, C. Roemer, J. Schild, D. Wincott, P. L. Wogelius, R. A. Vaughan, D. J. 0 OXFORD 15 Suppl. S 200VC; 17th Annual V M Goldschmidt Conference ; Conference date: 19-08-2007 Through 24-08-2007",

year = "2007",

month = aug,

doi = "10.1016/j.gca.2007.06.013",

language = "English",

isbn = "0016-7037",

volume = "71",

pages = "A160--A160",

booktitle = "GEOCHIMICA ET COSMOCHIMICA ACTA",

publisher = "Elsevier BV",

address = "Netherlands",

edition = "15 Suppl.1",

url = "https://www.geochemsoc.org/publications/geochemicalnews/gn134jan08/17thvmgoldschmidtconferenc",

}

Chardon, ES, Bosbach, D, Livens, FR , Lyon, IC, Marquardt, C, Romer, J, Schild, D, Wincott, PL, Wogelius, RA & Vaughan, DJ 2007, Surface analytical studies of feldspar surface reaction with U(VI). in GEOCHIMICA ET COSMOCHIMICA ACTA. 15 Suppl.1 edn, vol. 71, Elsevier BV, pp. A160-A160, 17th Annual V M Goldschmidt Conference, Cologne, Germany, 19/08/07. https://doi.org/10.1016/j.gca.2007.06.013

TY - GEN

T1 - Surface analytical studies of feldspar surface reaction with U(VI)

AU - Chardon, E S

AU - Bosbach, D

AU - Livens, F R

AU - Lyon, I C

AU - Marquardt, C

AU - Romer, J

AU - Schild, D

AU - Wincott, P L

AU - Wogelius, R A

AU - Vaughan, D J

N1 - Chardon, E. S. Bosbach, D. Livens, F. R. Lyon, I. C. Marquardt, C. Roemer, J. Schild, D. Wincott, P. L. Wogelius, R. A. Vaughan, D. J. 0 OXFORD 15 Suppl. S 200VC

PY - 2007/8

Y1 - 2007/8

N2 - Feldspar minerals are thermodynamically unstable in thenear-surface environment and their surfaces are well known toreact readily with aqueous solutions, leading to incongruentdissolution at low pH values, but congruent dissolution atneutral and high pH values. Interactions with mineral surfacesare an important control on the environmental transport oftrace elements and detrital feldspars are abundant in soils andsediments.The interaction of U(VI) ions with the feldspar surface hasbeen studied. Sorption experiments with uranyl ion (UO22+) atpH 2, 6 and 10 were carried out and measurable uptake,generally through surface complex formation, was only foundat pH 6 and 10. Reacted surfaces were analysed by X-rayphotoelectron spectroscopy and secondary ion massspectrometry. At pH 6 and at an initial U(VI) concentrationabove 21.0 μM, precipitation of a surface phase was observedby atomic force and scanning electron microscopies, and thiswas identified as becquerelite (Ca[UO2)3O2(OH)3]2.8H2O) bygrazing incidence X-ray diffraction. Secondary ion massspectrometry showed diffusion of uranium into the alteredsurface layer.

AB - Feldspar minerals are thermodynamically unstable in thenear-surface environment and their surfaces are well known toreact readily with aqueous solutions, leading to incongruentdissolution at low pH values, but congruent dissolution atneutral and high pH values. Interactions with mineral surfacesare an important control on the environmental transport oftrace elements and detrital feldspars are abundant in soils andsediments.The interaction of U(VI) ions with the feldspar surface hasbeen studied. Sorption experiments with uranyl ion (UO22+) atpH 2, 6 and 10 were carried out and measurable uptake,generally through surface complex formation, was only foundat pH 6 and 10. Reacted surfaces were analysed by X-rayphotoelectron spectroscopy and secondary ion massspectrometry. At pH 6 and at an initial U(VI) concentrationabove 21.0 μM, precipitation of a surface phase was observedby atomic force and scanning electron microscopies, and thiswas identified as becquerelite (Ca[UO2)3O2(OH)3]2.8H2O) bygrazing incidence X-ray diffraction. Secondary ion massspectrometry showed diffusion of uranium into the alteredsurface layer.

KW - Geochemistry & Geophysics

U2 - 10.1016/j.gca.2007.06.013

DO - 10.1016/j.gca.2007.06.013

M3 - Conference contribution

SN - 0016-7037

VL - 71

SP - A160-A160

BT - GEOCHIMICA ET COSMOCHIMICA ACTA

PB - Elsevier BV

T2 - 17th Annual V M Goldschmidt Conference

Y2 - 19 August 2007 through 24 August 2007

ER -

Surface analytical studies of feldspar surface reaction with U(VI)

Abstract

Conference

Keywords

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