Clay mineral weathering and contaminant dynamics in a caustic aqueous system II. Mineral transformation and microscale partitioning

Sunkyung Choi, Garry Crosson, Karl T. Mueller, Supapan Seraphin, Jon Chorover

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

Microscopic and spectroscopic studies were conducted to assess mineral transformation processes in aqueous suspensions of illite (Il), vermiculite (Vm) and montmorillonite (Mt) that were subjected to weathering in a simulated high-level radioactive tank waste leachate (0.05 M AlT, 2 M Na+, 1 M NO3-, pH ∼14, Cs+ and Sr2+ present as co-contaminants). Time series (0 to 369 d) experiments were conducted at 298 K, with initial [Cs]0 and [Sr]0 concentrations from 10-5 to 10- mol kg-. Incongruent clay dissolution resulted in an accumulation of secondary aluminosilicate precipitates identified as nitrate-sodalite, nitrate-cancrinite and zeolite X, by molecular spectroscopy and electron microscopy (XRD, IR, NMR, SEM-EDS and TEM-EDS). Contaminant fate was dependent on competing uptake to parent clays and weathering products. TEM-EDS results indicated that high Il affinity for Cs was due to adsorption at frayed edge sites. The Il system also comprised Sr-rich aluminous precipitates after 369 d reaction time. In Mt systems, Cs and Sr were co-precipitated into increasingly recalcitrant spheroidal precipitates over the course of the experiment, whereas contaminant association with montmorillonite platelets was less prevalent. In contrast, Cs and Sr were found in association with weathered Vm particles despite the formation of spheroidal aluminosilicate precipitates that were comparable to those formed from Mt. dissolution.

Original languageEnglish (US)
Pages (from-to)4437-4451
Number of pages15
JournalGeochimica et Cosmochimica Acta
Volume69
Issue number18
DOIs
StatePublished - Sep 15 2005

Fingerprint

Bentonite
Caustics
Weathering
Clay minerals
montmorillonite
Minerals
clay mineral
Precipitates
partitioning
weathering
illite
Impurities
Energy dispersive spectroscopy
pollutant
vermiculite
aluminosilicate
mineral
Nitrates
transmission electron microscopy
Dissolution

ASJC Scopus subject areas

  • Geochemistry and Petrology

Cite this

Clay mineral weathering and contaminant dynamics in a caustic aqueous system II. Mineral transformation and microscale partitioning. / Choi, Sunkyung; Crosson, Garry; Mueller, Karl T.; Seraphin, Supapan; Chorover, Jon.

In: Geochimica et Cosmochimica Acta, Vol. 69, No. 18, 15.09.2005, p. 4437-4451.

Research output: Contribution to journalArticle

@article{3dee9bd05409406284fbf5d01af88e2d,
title = "Clay mineral weathering and contaminant dynamics in a caustic aqueous system II. Mineral transformation and microscale partitioning",
abstract = "Microscopic and spectroscopic studies were conducted to assess mineral transformation processes in aqueous suspensions of illite (Il), vermiculite (Vm) and montmorillonite (Mt) that were subjected to weathering in a simulated high-level radioactive tank waste leachate (0.05 M AlT, 2 M Na+, 1 M NO3-, pH ∼14, Cs+ and Sr2+ present as co-contaminants). Time series (0 to 369 d) experiments were conducted at 298 K, with initial [Cs]0 and [Sr]0 concentrations from 10-5 to 10- mol kg-. Incongruent clay dissolution resulted in an accumulation of secondary aluminosilicate precipitates identified as nitrate-sodalite, nitrate-cancrinite and zeolite X, by molecular spectroscopy and electron microscopy (XRD, IR, NMR, SEM-EDS and TEM-EDS). Contaminant fate was dependent on competing uptake to parent clays and weathering products. TEM-EDS results indicated that high Il affinity for Cs was due to adsorption at frayed edge sites. The Il system also comprised Sr-rich aluminous precipitates after 369 d reaction time. In Mt systems, Cs and Sr were co-precipitated into increasingly recalcitrant spheroidal precipitates over the course of the experiment, whereas contaminant association with montmorillonite platelets was less prevalent. In contrast, Cs and Sr were found in association with weathered Vm particles despite the formation of spheroidal aluminosilicate precipitates that were comparable to those formed from Mt. dissolution.",
author = "Sunkyung Choi and Garry Crosson and Mueller, {Karl T.} and Supapan Seraphin and Jon Chorover",
year = "2005",
month = "9",
day = "15",
doi = "10.1016/j.gca.2005.04.004",
language = "English (US)",
volume = "69",
pages = "4437--4451",
journal = "Geochmica et Cosmochimica Acta",
issn = "0016-7037",
publisher = "Elsevier Limited",
number = "18",

}

TY - JOUR

T1 - Clay mineral weathering and contaminant dynamics in a caustic aqueous system II. Mineral transformation and microscale partitioning

AU - Choi, Sunkyung

AU - Crosson, Garry

AU - Mueller, Karl T.

AU - Seraphin, Supapan

AU - Chorover, Jon

PY - 2005/9/15

Y1 - 2005/9/15

N2 - Microscopic and spectroscopic studies were conducted to assess mineral transformation processes in aqueous suspensions of illite (Il), vermiculite (Vm) and montmorillonite (Mt) that were subjected to weathering in a simulated high-level radioactive tank waste leachate (0.05 M AlT, 2 M Na+, 1 M NO3-, pH ∼14, Cs+ and Sr2+ present as co-contaminants). Time series (0 to 369 d) experiments were conducted at 298 K, with initial [Cs]0 and [Sr]0 concentrations from 10-5 to 10- mol kg-. Incongruent clay dissolution resulted in an accumulation of secondary aluminosilicate precipitates identified as nitrate-sodalite, nitrate-cancrinite and zeolite X, by molecular spectroscopy and electron microscopy (XRD, IR, NMR, SEM-EDS and TEM-EDS). Contaminant fate was dependent on competing uptake to parent clays and weathering products. TEM-EDS results indicated that high Il affinity for Cs was due to adsorption at frayed edge sites. The Il system also comprised Sr-rich aluminous precipitates after 369 d reaction time. In Mt systems, Cs and Sr were co-precipitated into increasingly recalcitrant spheroidal precipitates over the course of the experiment, whereas contaminant association with montmorillonite platelets was less prevalent. In contrast, Cs and Sr were found in association with weathered Vm particles despite the formation of spheroidal aluminosilicate precipitates that were comparable to those formed from Mt. dissolution.

AB - Microscopic and spectroscopic studies were conducted to assess mineral transformation processes in aqueous suspensions of illite (Il), vermiculite (Vm) and montmorillonite (Mt) that were subjected to weathering in a simulated high-level radioactive tank waste leachate (0.05 M AlT, 2 M Na+, 1 M NO3-, pH ∼14, Cs+ and Sr2+ present as co-contaminants). Time series (0 to 369 d) experiments were conducted at 298 K, with initial [Cs]0 and [Sr]0 concentrations from 10-5 to 10- mol kg-. Incongruent clay dissolution resulted in an accumulation of secondary aluminosilicate precipitates identified as nitrate-sodalite, nitrate-cancrinite and zeolite X, by molecular spectroscopy and electron microscopy (XRD, IR, NMR, SEM-EDS and TEM-EDS). Contaminant fate was dependent on competing uptake to parent clays and weathering products. TEM-EDS results indicated that high Il affinity for Cs was due to adsorption at frayed edge sites. The Il system also comprised Sr-rich aluminous precipitates after 369 d reaction time. In Mt systems, Cs and Sr were co-precipitated into increasingly recalcitrant spheroidal precipitates over the course of the experiment, whereas contaminant association with montmorillonite platelets was less prevalent. In contrast, Cs and Sr were found in association with weathered Vm particles despite the formation of spheroidal aluminosilicate precipitates that were comparable to those formed from Mt. dissolution.

UR - http://www.scopus.com/inward/record.url?scp=26444500479&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=26444500479&partnerID=8YFLogxK

U2 - 10.1016/j.gca.2005.04.004

DO - 10.1016/j.gca.2005.04.004

M3 - Article

AN - SCOPUS:26444500479

VL - 69

SP - 4437

EP - 4451

JO - Geochmica et Cosmochimica Acta

JF - Geochmica et Cosmochimica Acta

SN - 0016-7037

IS - 18

ER -