Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-07T07:24:05.207Z Has data issue: false hasContentIssue false
  • English
  • Français

A Model for the Mechanism of Fe3+ to Fe2+ Reduction in Dioctahedral Smectites

Published online by Cambridge University Press:  28 February 2024

V. A. Drits  and
A. Manceau
V. A. Drits
Affiliation:
Environmental Geochemistry Group, LGIT-IRIGM, University Joseph Fourier and CNRS, 38041 Grenoble Cedex 9, France Geological Institute of the Russian Academy of Sciences, 7 Pyzhevsky Street, 109017 Moscow, Russia
A. Manceau
Affiliation:
Environmental Geochemistry Group, LGIT-IRIGM, University Joseph Fourier and CNRS, 38041 Grenoble Cedex 9, France
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

A model to compensate the 2:1 layer having excess negative charge owing to the reduction of Fe3+ to Fe2+ by sodium dithionite buffered with citrate-bicarbonate in nontronite, beidellite, and montmorillonite is proposed. This model is based on reassessing published experimental data for Fe-containing smectites and on a recently published structural model for reduced Garfield nontronite. In the reduced state, Fe2+ cations remain six-fold coordinated, and increases of negative charge in the 2:1 layer are compensated by the sorption of Na+ and H+ from solution. Some of the incorporated protons react with structural OH groups to cause dehydroxylation. Also, some protons bond with undersaturated oxygen atoms of the octahedral sheet. The amount of Na+ (p) and H+ (ni) cations incorporated in the structure as a function of the amount of Fe reduction can be described quantitatively by two equations: p = m/(1 + K0mrel) and ni = K0mrel/(1 + K0mrel); with K0 = CEC (9.32 − 1.06mtot + 0.02mtot2), where mtot is the total Fe content in the smectite, m is the Fe2+ content, mrel is the reduction level (m/mtot), CEC is the cation-exchange capacity, and K0 is a constant specific to the smectite. The model can predict, from the chemical composition of a smectite, the modifications of its properties as a function of reduction level. Based on this model, the structural mechanism of Fe3+ reduction in montmorillonite differs from that determined in nontronite and beidellite owing to differences in the distribution of cations over trans- and cis-octahedral sites.

Keywords

CMS Source Clay SWa-1Dioctahedral SmectiteIron ReductionStructural Formula
Type
Research Article
Information
Clays and Clay Minerals , Volume 48 , Issue 2 , April 2000 , pp. 185 - 195
Copyright
Copyright © 2000, The Clay Minerals Society

References

Chen, S.Z. Low, P.E. and Roth, C.B., 1987 Relation between potassium fixation and the oxidation state of octahedral iron Soil Science Society of America Journal 51 82–86 10.2136/sssaj1987.03615995005100010017x.CrossRefGoogle Scholar
Drits, V.A. Plançon, A. Sakharov, B.A. Besson, G. Tsipursky, S.I. and Tchoubar, C., 1984 Diffraction effects calculated for structural models of K-saturated montmorillonite containing different types of defects Clay Minerals 19 541–561 10.1180/claymin.1984.019.4.03.Google Scholar
Drits, V.A. Weber, A.I. Salyn, A.L. and Tsipursky, S.I., 1993 X-ray identification of one-layer illite varieties: Application to the study of illites around uranium deposits of Canada Clays and Clay Minerals 41 389–398 10.1346/CCMN.1993.0410316.CrossRefGoogle Scholar
Drits, V.A. Besson, G. and Muller, E., 1995 An improved model for structural transformation of heat-treated aluminous dioctahedral 2:1 layer silicates Clays and Clay Minerals 43 718–731 10.1346/CCMN.1995.0430608.CrossRefGoogle Scholar
Dunitz, J.D., 1956 The structure of sodium dithionite and the nature of the dithionite ion Acta Crystallographica 9 579–586 10.1107/S0365110X56001601.CrossRefGoogle Scholar
Egashira, K. and Ohtsubo, M., 1983 Swelling and mineralogy of smectites in paddy soils derived from marine alluvium, Japan Geoderma 29 119–127 10.1016/0016-7061(83)90036-8.CrossRefGoogle Scholar
Ernstsen, V., 1998 Reduction of nitrate by Fe2+ in clay minerals Clays and Clay Minerals 44 599–608 10.1346/CCMN.1996.0440503.CrossRefGoogle Scholar
Gan, H. Stucki, J.W. and Bailey, G.W., 1992 Reduction of structural iron in ferruginous smectites by free radicals Clays and Clay Minerals 40 659–665 10.1346/CCMN.1992.0400605.CrossRefGoogle Scholar
Gates, W.P. Jaunet, A.M. Tessier, D. Cole, M.A. Wilkinson, H.T. and Stucki, J.W., 1998 Swelling and texture of ironbearing smectites reduced by bacteria Clays and Clay Minerals 46 487–497 10.1346/CCMN.1998.0460502.CrossRefGoogle Scholar
Güven, N. and Bailey, S.W., 1991 Smectites Hydrous Phyllosilicates (Exclusive of Micas), Reviews in Mineralogy, Volume 19 Washington, D.C. Mineralogical Society of America 497–560.Google Scholar
Heller-Kallai, L., 1997 Reduction and reoxidation of nontronite. The data reassessed Clays and Clay Minerals 45 476–479 10.1346/CCMN.1997.0450316.CrossRefGoogle Scholar
Khaled, E.M. and Stucki, J.W., 1991 Effect of iron oxidation state on cation fixation in smectites Soil Science Society of America Journal 55 550–554 10.2136/sssaj1991.03615995005500020045x.CrossRefGoogle Scholar
Lear, P.R. and Stucki, J.W., 1985 The role of structural hydrogen in the reduction and reoxidation of iron in nontronite Clays and Clay Minerals 33 539–545 10.1346/CCMN.1985.0330609.CrossRefGoogle Scholar
Lear, P.R. and Stucki, J.W., 1989 Effects of iron oxidation state on the specific area of nontronites Clays and Clay Minerals 37 547–552 10.1346/CCMN.1989.0370607.CrossRefGoogle Scholar
Low, P.F. Roth, C.B. and Stucki, J.W., 1983 System and method for rapid beneficiation of bentonite clay .Google Scholar
Lynn, S. Rinker, R.G. and Corcoran, W.H., 1964 The monomerization rate of dithionite ion in aqueous solution Journal of Physical Chemistry 68 2363 10.1021/j100790a505.CrossRefGoogle Scholar
Manceau, A. Drits, V.A. Lanson, B. Chateigner, D. Wu, J. Huo, D.F. Gates, W.P. and Stucki, J.W., 2000 Oxidationreduction mechanism of iron in dioctahedral smectites. 2. Structural chemistry of reduced Garfield nontronite American Mineralogist 85 153–172 10.2138/am-2000-0115.CrossRefGoogle Scholar
Muller, E. Drits, V.A. Plancjon, A. Besson, G. and Tsipursky, S., 2000 Structural transformation of heat-treated Fe3+-rich dioctahedral micas. Part I: Characterization of the structural transformation Clay Minerals .Google Scholar
Rinker, R.G. Gordon, T.P. Mason, D.M. and Corcoran, W.H., 1958 The presence of the SO2− radical ion in aqueous solutions of sodium dithionite Journal of Physical Chemistry 63 302 10.1021/j150572a042.CrossRefGoogle Scholar
Roth, C.B. Tullock, R.J. and Serratosa, J.M., 1973 Deprotonation of nontronite resulting from chemical reduction of structural ferric iron Proceeding of the International Clay Conference Madrid Division Ciencas C.S.I.C. 107–114.Google Scholar
Rozenson, I. and Heller-Kallai, L., 1976 Reduction and oxidation of Fe3+ in dioctahedral smectite. 1: Reduction with hydrazine and dithionite Clays and Clay Minerals 24 271–282 10.1346/CCMN.1976.0240601.CrossRefGoogle Scholar
Russell, J.D. Goodman, B.A. and Fraser, A.R., 1979 Infrared and Mossbauer studies of reduced nontronites Clays and Clay Minerals 27 63–71 10.1346/CCMN.1979.0270108.CrossRefGoogle Scholar
Shen, S. Stucki, J.W. and Boast, C.W., 1992 Effects of structural iron reduction on the hydraulic conductivity of Na-smectite Clays and Clay Minerals 40 381–386 10.1346/CCMN.1992.0400402.CrossRefGoogle Scholar
Stucki, J.W., Stucki, J.W. Goodman, B.A. and Schwertmann, U., 1988 Structural iron in smectites Iron in Soils and Clay Minerals Dordrecht Riedel Publishing Company 625–676 10.1007/978-94-009-4007-9_17.CrossRefGoogle Scholar
Stucki, J.W. and Roth, C.B., 1976 Interpretation of infrared spectra of oxidized and reduced nontronite Clays and Clay Minerals 24 293–296 10.1346/CCMN.1976.0240604.CrossRefGoogle Scholar
Stucki, J.W. and Roth, C.B., 1977 Oxidation-reduction mechanism for structural iron in nontronite Soil Science Society of America Journal 41 808–814 10.2136/sssaj1977.03615995004100040041x.CrossRefGoogle Scholar
Stucki, J.W. and Tessier, D., 1991 Effects of iron oxidation state on the structural order of Na-nontronite Clays and Clay Minerals 39 137–143 10.1346/CCMN.1991.0390204.CrossRefGoogle Scholar
Stucki, J.W. Roth, C.B. and Baitinger, W.E., 1976 Analysis of iron-bearing clay minerals by electron spectroscopy for chemical analysis (ESCA) Clays and Clay Minerals 24 289–292 10.1346/CCMN.1976.0240603.CrossRefGoogle Scholar
Stucki, J.W. Golden, D.C. and Roth, C.B., 1984 Effects of reduction and reoxidation of structural iron on the surface charge and dissolution of dioctahedral smectites Clays and Clay Minerals 32 350–356 10.1346/CCMN.1984.0320502.CrossRefGoogle Scholar
Stucki, J.W. Komadel, P. and Wilkinson, H.T., 1987 The microbial reduction of structural iron3+ in smectites Soil Science Society of America Journal 51 1663–1665 10.2136/sssaj1987.03615995005100060047x.CrossRefGoogle Scholar
Stucki, J.W. Bailey, G.W. and Gan, H., 1996 Oxidationreduction mechanisms in iron-bearing phyllosilicates Applied Clay Science 10 417–430 10.1016/0169-1317(96)00002-6.CrossRefGoogle Scholar
Tsipursky, S.I. and Drits, V.A., 1984 The distribution of cations in the 2:1 layers of dioctahedral smectites studied by oblique-texture electron diffraction Clay Minerals 19 177–193 10.1180/claymin.1984.019.2.05.CrossRefGoogle Scholar
Tsipursky, S.I. Kamenova, M.Y. Drits, V.A. and Konta, J., 1985 Structural transformation of Fe3+-containing 2:1 dioctahedral phyllosilicates in the course of dehydroxylation European Clay Conference Praha Univerzita Karlova Praha 564–577.Google Scholar