Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-27T20:20:54.595Z Has data issue: false hasContentIssue false
  • English
  • Français

Molecular Structure and Binding Sites of Cobalt(II) Surface Complexes on Kaolinite from X-Ray Absorption Spectroscopy

Published online by Cambridge University Press:  28 February 2024

Peggy A. O'Day ,
George A. Parks  and
Gordon E. Brown Jr.
Peggy A. O'Day
Affiliation:
Surface and Aqueous Geochemistry Group, School of Earth Sciences, Stanford University, Stanford, California 94305, USA
George A. Parks
Affiliation:
Surface and Aqueous Geochemistry Group, School of Earth Sciences, Stanford University, Stanford, California 94305, USA
Gordon E. Brown Jr.
Affiliation:
Surface and Aqueous Geochemistry Group, School of Earth Sciences, Stanford University, Stanford, California 94305, USA
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.

X-ray absorption spectroscopy (XAS) was used to determine the local molecular environment of Co(II) surface complexes sorbed on three different kaolinites at ambient temperature and pressure in contact with an aqueous solution. Interatomic distances and types and numbers of backscattering atoms have been derived from analysis of the extended X-ray absorption fine structure (EXAFS). These data show that, at the lowest amounts of Co uptake on kaolinite (0.20–0.32 µmol m−2), Co is surrounded by ≈6 O atoms at 2.04–2.08 Å and a small number or Al or Si atoms (N = 0.6–1.5) at two distinct distances, 2.67–2.72 Å and 3.38–3.43 Å. These results indicate that Co bonds to the kaolinite surface as octahedrally coordinated, bidentate inner-sphere mononuclear complexes at low surface coverages, confirming indirect evidence from solution studies that a fraction of sorbed Co forms strongly bound complexes on kaolinite. In addition to inner-sphere complexes identified by EXAFS spectroscopy, solution studies provide evidence for the presence of weakly bound, outer-sphere Co complexes that cannot be detected directly by EXAFS. One orientation for inner-sphere complexes indicated by XAS is bidentate bonding of Co to oxygen atoms at two Al-O-Si edge sites or an Al-O-Si and Al-OH (inner hydroxyl) edge site, i.e., corner-sharing between Co octahedra and Al and Si polyhedra. At slightly higher surface sorption densities (0.51–0.57/ µmol m−2), the presence of a small number of second-neighbor Co atoms (average NCo < 1) at 3.10–3.13 Å indicates the formation of oxy- or hydroxy-bridged, multinuclear surface complexes in addition to mononuclear complexes. At these surface coverages, Co-Co and Co-Al/Si distances derived from EXAFS are consistent with edge-sharing between Co and Al octahedra on either edges or (001) faces of the aluminol sheet in kaolinite. Multinuclear complexes form on kaolinite at low surface sorption densities equivalent to <5% coverage by a monolayer of oxygen-ligated Co octahedra over the N2-BET surface area. These spectroscopic results have several implications for macroscopic modeling of metal ion uptake on kaolinite: 1) Primary binding sites on the kaolinite surface at low uptake are edge, non-bridging Al-OH inner hydroxyl sites and edge Al-O-Si bridging oxygen sites, not Si-OH sites typically assumed in sorption models; 2) specific adsorption of Co is via bidentate, inner-sphere complexation; and 3) at slightly higher uptake but still a small fraction of monolayer coverage, formation of Co multinuclear complexes, primarily edge-sharing with Al-OH octahedra, begins to dominate sorption.

Keywords

CobaltEXAFSKaoliniteSorptionSurface complex
Type
Research Article
Information
Clays and Clay Minerals , Volume 42 , Issue 3 , June 1994 , pp. 337 - 355
Copyright
Copyright © 1994, Clay Minerals Society

References

Ashley, C. A., and Doniach, S., (1975) Theory of extended X-ray absorption fine structure (EXAFS) in crystalline solids: Phys. Rev. B11, 1279–1288.CrossRefGoogle Scholar
Baes, C. F. Jr. and Mesmer, R. E., (1976) The Hydrolysis of Cations: John Wiley & Sons, New York, 489 pp.Google Scholar
Bancroft, G. M., and Hyland, M. M., (1990) Spectroscopic studies of adsorption/reduction reactions of aqueous metal complexes on sulphide surfaces: in Mineral-Water Interface Geochemistry, Hochella, M. F. Jr. and White, A. F., eds., Reviews in Mineralogy 23, Mineralogical Society of America, Washington, D.C., 511–558.CrossRefGoogle Scholar
Bish, D. L., and Von Dreele, R. B., (1989) Rietveld refinement of non-hydrogen atomic positions in kaolinite: Clays & Clay Minerals 37, 289–296.CrossRefGoogle Scholar
Bleam, W. F., and McBride, M. B., (1985) Cluster formation vs. isolated-site adsorption. A study of Mn(II) and Mg(II) adsorption on boehmite and goethite: J. Colloid Interface Sci. 103, 124–132.CrossRefGoogle Scholar
Bol, W., Gerrits, G. J. A., and van Panthaleon van Eck, C. L., (1970) The hydration of divalent cations in aqueous solution. An X-ray investigation with isomorphous replacement: J. Appl. Cryst. 3, 486–492.CrossRefGoogle Scholar
Bolland, M. D. A., Posner, A. M., and Quirk, J. P., (1976) Surface charge in kaolinites in aqueous suspension: Aust. J. Soil Res. 14, 197–216.CrossRefGoogle Scholar
Bolland, M. D. A., Posner, A. M., and Quirk, J. P., (1980) pH-independent and pH-dependent surface charges on kaolinite: Clays & Clay Minerals 28, 412–418.CrossRefGoogle Scholar
Brown, G. E. Jr. () Spectroscopic studies of chemisorption reaction mechanisms at oxide-water interfaces: in Mineral-Water Interface Geochemistry, Hochella, M. F. Jr. and White, A. F., 1990 eds., Reviews in Mineralogy 23, Mineralogical Society of America, Washington, D.C., 309–363.CrossRefGoogle Scholar
Brown, G. E. Jr., Calas, G., Waychunas, G. A., and Petiau, J., (1988) X-ray absorption spectroscopy and its applications in mineralogy and geochemistry: in Spectroscopic Methods in Mineralogy and Geology, F. C. Hawthorne ed., Reviews in Mineralogy 18, Mineralogical Society of America, Washington, D.C., 431–512.CrossRefGoogle Scholar
Brown, G. E. Jr. and Parks, G. A., (1989) Synchrotron-based x-ray absorption studies of cation environments in earth materials: Reviews of Geophysics 27, 519–533.CrossRefGoogle Scholar
Brown, G. E. Jr., Parks, G. A., and Chisholm-Brause, C. J., (1989) In-situ x-ray absorption spectroscopic studies of ions at oxide-water interfaces: Chimia 43, 248–256.Google Scholar
Calas, G., and Petiau, J., (1983) Coordination of iron in oxide glasses through high-resolution K-edge spectra: Information from the pre-edge: Solid State Comm. 48, 625–629.CrossRefGoogle Scholar
Carroll, S. A., and Walther, J. V., (1990) Temperature dependence of kaolinite dissolution rates. Amer. J. Sci. 290, 797–810.CrossRefGoogle Scholar
Carroll-Webb, S. A., and Walther, J. V., (1988) A surface complex reaction model for the pH-dependence of corundum and kaolinite dissolution rates: Geochim. Cosmochim. Acta 52, 2609–2623.CrossRefGoogle Scholar
Charlet, L., and Manceau, A., (1992) X-ray absorption spectroscopic study of the sorption of Cr(II) at the oxide-water interface. II. Adsorption, coprecipitation, and surface precipitation on hydrous ferric oxide: J. Colloid Interface Sci. 148, 443–458.CrossRefGoogle Scholar
Chisholm-Brause, C. J., (1991) Spectroscopic and equilibrium study of cobalt(II) sorption complexes at oxide/water interfaces: Doctoral thesis, Stanford University, Stanford, California, 118 pp.Google Scholar
Chisholm-Brause, C. J., Hayes, K. F., Roe, A. L., Brown, G. E. Jr., Parks, G. A., and Leckie, J. O., (1990a) Spectroscopic investigation of Pb(II) complexes at the γ-Al2O3/water interface: Geochim. Cosmochim. Acta 54, 1897–1909.CrossRefGoogle Scholar
Chisholm-Brause, C. J., O'Day, P. A., Brown, G. E. Jr., and Parks, G. A., (1990b) Evidence for multinuclear metalion complexes at solid/water interfaces from X-ray absorption spectroscopy: Nature 348, 528–530.CrossRefGoogle ScholarPubMed
Combes, J. M., Manceau, A., Calas, G., and Bottero, J. Y., (1989) Formation of ferric oxides from aqueous solutions: A polyhedral approach by X-ray absorption spectroscopy. I. Hydrolysis and formation of ferric gels: Geochim. Cosmochim. Acta 53, 583–594.CrossRefGoogle Scholar
Combes, J. M., Manceau, A., and Calas, G., (1990) Formation of ferric oxides from aqueous solutions: A polyhedral approach by X-ray absorption spectroscopy. II. Hematite formation from ferric gels: Geochim. Cosmochim. Acta 54, 1083–1091.CrossRefGoogle Scholar
Cowan, C. E., Zachara, J. M., Smith, S. C., and Resch, C. T., (1992) Individual sorbent contributions to cadmium sorption on ultisols of mixed mineralogy: Soil Sci. Soc. Am. J. 56, 1084–1094.CrossRefGoogle Scholar
Cramer, S. P., and Hodgson, K. O., (1979) X-ray absorption spectroscopy: A new structural method and its applications to bioinorganic chemistry: Prog. Inorg. Chem. 25, 1–39.Google Scholar
Crozier, E. D., Rehr, J. J., and Ingalls, R., (1988) Amorphous and liquid systems: in X-ray Absorption: Principles, Applications, Techniques of EXAFS, SEXAFS, and XANES, Koningsberger, D. C., and Prins, R., eds., Chemical Analysis 92, John Wiley & Sons, New York, 373–442.Google Scholar
Davis, J. A., and Hayes, K. F., 1986 eds. () Geochemical Processes at Mineral Surfaces, ACS Symposium Series 323, 683 pp.Google Scholar
Davis, J. A., and Kent, D. B., (1990) Surface complexation modeling in aqueous geochemistry: in Mineral-Water Interface Geochemistry, Hochella, M. F. Jr. and White, A. F., eds., Reviews in Mineralogy 23, Mineralogical Society of America, Washington, D.C., 177–260.CrossRefGoogle Scholar
Davison, N., McWhinnie, W. R., and Hooper, A., (1991) X-ray photoelectron spectroscopy study of cobalt(II) and nickel(II) sorbed on hectorite and montmorillonite: Clays & Clay Minerals 39, 22–27.CrossRefGoogle Scholar
Dent, A. J., Ramsay, J. D. F., and Swanton, W., (1992) An EXAFS study of uranyl ion in solution and sorbed onto silica and montmorillonite clay colloids: J. Colloid Interface Sci. 150, 45–60.CrossRefGoogle Scholar
Dillard, J. G., and Koppelman, M. H., (1982) X-ray photoelectron spectroscopic (XPS) surface characterization of cobalt on the surface of kaolinite: J. Colloid Interface Sci. 87, 46–55.CrossRefGoogle Scholar
Dzombak, D. A., and Morel, F. M. M., (1990) Surface Complexation Modeling: Hydrous Ferric Oxide: John Wiley & Sons, New York, 393 pp.Google Scholar
Farley, K. J., Dzombak, D. A., and Morel, F. M. M., (1985) A surface precipitation model for the sorption of cations on metal oxides: J. Colloid Interface Sci. 106, 226–242.CrossRefGoogle Scholar
Farrah, H., Hatton, D., and Pickering, W. F., (1980) The affinity of metal ions for clay surfaces: Chem. Geology 28, 55–56.CrossRefGoogle Scholar
Feitknecht, W., and Schindler, P., (1963) Solubility constants of metal oxides, metal hydroxides and metal hydroxide salts in aqueous solution: Pure Applied Chem. 6, 130–199.CrossRefGoogle Scholar
Ferris, A. P., and Jepson, W. B., (1975) The exchange capacities of kaolinite and the preparation of homoionic clays: J. Colloid Interface Sci. 51, 245–259.CrossRefGoogle Scholar
Follet, E. A. C., (1965) The retention of amorphous, colloidal “ferric hydroxide” by kaolinites: J. Soil Sci. 16, 334–341.CrossRefGoogle Scholar
Fordham, A. W., (1973) The location of iron-55, strontium-85, and iodide-125 sorbed by kaolinite and dickite particles: Clays & Clay Minerals 21, 175–184.CrossRefGoogle Scholar
Gayer, K. H., and Garrett, A. B., (1950) The solubility of cobalt hydroxide, Co(OH)2, in solutions of hydrochloric acid and sodium hydroxide at 25°C: J. Amer. Chem. Soc. 72, 3921–3923.CrossRefGoogle Scholar
Giese, R. F. Jr. () Kaolin minerals: Structures and stabilities: in Hydrous Phyllosilicates, Bailey, S. W., 1988 ed., Reviews in Mineralogy 19, Mineralogical Society of America, Washington, D.C., 29–66.CrossRefGoogle Scholar
Grim, R. E., (1968) Clay Mineralogy: McGraw-Hill, New York, 596 pp.Google Scholar
Hahn, J. E., and Hodgson, K. O., (1983) Polarized x-ray absorption spectroscopy: in Inorganic Chemistry: Toward the 21st Century, Chisholm, M. H., ed., ACS Symposium Series 211, Washington, D.C., 432–444.Google Scholar
Hayes, K. F., and Leckie, J. O., (1987) Modeling ionic strength effects on cation adsorption at hydrous oxide/solution interfaces: J. Colloid Interface Sci. 115, 564–572.CrossRefGoogle Scholar
Hayes, K. F., Roe, A. L., Brown, G. E. Jr., Hodgson, K. O., Leckie, J. O., and Parks, G. A., (1987) In situ X-ray absorption study of surface complexes at oxide/water interfaces: Selenium oxyanions on α-FeOOH: Science 238, 783–786.CrossRefGoogle Scholar
Heald, S. M., and Stern, E. A., (1977) Anisotropic X-ray absorption in layered compounds: Phys. Rev. B16, 5549–5559.CrossRefGoogle Scholar
Hochella, M. F. Jr. and White, A. F., 1990 eds. () Mineral-Water Interface Geochemistry, Reviews in Mineralogy 23, Mineralogical Society of America, Washington, D.C., 603 pp.CrossRefGoogle Scholar
Jackson, M. L., (1975) Soil Chemical Analysis—Advanced Course, 2nd ed., published by the author, Department of Soil Science, University of Wisconsin, Madison, Wisconsin, 894 pp.Google Scholar
Jepson, W. B., and Rowse, J. B., (1975) The composition of kaolinite—an electron microscope microprobe study: Clays & Clay Minerals 28, 310–317.CrossRefGoogle Scholar
Koningsberger, D. C., and Prins, R., 1988 eds. () X-ray Absorption: Principles, Applications, Techniques of EXAFS, SEXAFS, and XANES, Chemical Analysis 92, John Wiley & Sons, New York, 673 pp.Google Scholar
Koppelman, M. H., and Dillard, J. G., (1975) An ESCA study of sorbed metal ions on clay minerals: in Marine Chemistry in the Coastal Environment, Church, T. M., ed., ACS Symposium Series 18, Washington, D.C., 186–201.CrossRefGoogle Scholar
Koppelman, M. H., and Dillard, J. G., (1977) A study of the adsorption of Ni(II) and Cu(II) by clay minerals: Clays & Clay Minerals 25, 457–462.CrossRefGoogle Scholar
Koppelman, M. H., Emerson, A. B., and Dillard, J. G., (1980) Adsorbed Cr(III) on chlorite, illite, and kaolinite: An X-ray photoelectron spectroscopic study: Clays & Clay Minerals 28, 119–124.CrossRefGoogle Scholar
Lee, S. Y., Jackson, M. L., and Brown, J. L., (1975) Micaceous occlusions in kaolinite observed by ultramicrotomy and high resolution electron microscopy: Clays & Clay Minerals 23, 125–129.CrossRefGoogle Scholar
Lim, C. H., Jackson, M. L., Koons, R. D., and Helmke, P. A., (1980) Kaolins: Sources of differences in cation-exchange capacities and cesium retention: Clays & Clay Minerals 28, 223–229.CrossRefGoogle Scholar
Lotmar, W., and Feitknecht, W., (1936) Uber anderungen der ionenabstande in hydroxyd-schichtengittern: Z. Krist. A93, 368–378.Google Scholar
Lytle, F. W., (1989) Experimental X-ray absorption spectroscopy: in Applications of Synchrotron Radiation, Winick, H., et al., eds., Gordon and Breach Science Publ., 135–223.Google Scholar
Lytle, F. W., Sandstrom, D. R., Marques, E. C., Wong, J., Spiro, C. L., Huffman, G. P., and Huggins, F. E., (1984) Measurement of soft x-ray absorption spectra with a fluorescence ion chamber detector: Nucl. Instr. and Meth. 226, 542–548.CrossRefGoogle Scholar
Manceau, A., Bonnin, D., Kaiser, P., and Fretigny, C., (1988) Polarized EXAFS of biotite and chlorite: Phys. Chem. Minerals 16, 180–185.CrossRefGoogle Scholar
Manceau, A., and Charlet, L., (1992) X-ray absorption spectroscopic study of the sorption of Cr(II) at the oxide-water interface. I. Molecular mechanism of Cr(III) oxidation on Mn oxides: J. Colloid Interface Sci. 148, 425–442.CrossRefGoogle Scholar
Manceau, A., Charlet, L., Boisset, M. C., Didier, B., and Spadini, L., (1992) Sorption and speciation of heavy metals on hydrous Fe and Mn oxides. From microscopic to macroscopic: Applied Clay Sci. 7, 201–223.CrossRefGoogle Scholar
Manceau, A., and Combes, J. M., (1988) Structure of Mn and Fe oxides and oxyhydroxides: A topological approach by EXAFS: Phys. Chem. Minerals 15, 283–295.CrossRefGoogle Scholar
May, H. M., Kinniburgh, D. G., Helmke, P. A., and Jackson, M. L., (1986) Aqueous dissolution, solubilities and thermodynamic stabilities of common aluminosilicate clay minerals: Kaolinite and smectites: Geochim. Cosmochim. Acta 50, 1667–1677.CrossRefGoogle Scholar
McBride, M. B., (1976) Origin and position of exchange sites in kaolinite: An ESR study: Clays & Clay Minerals 24, 88–92.CrossRefGoogle Scholar
McBride, M. B., (1978) Copper(II) interactions with kaolinite: Factors controlling adsorption. Clays & Clay Minerals 26, 101–106.CrossRefGoogle Scholar
McBride, M. B., Fraser, A. R., and McHardy, W. J., (1984) Cu2+ interaction with microcrystalline gibbsite. Evidence for oriented chemisorbed copper ions: Clays & Clay Minerals 32, 12–18.CrossRefGoogle Scholar
McMaster, W. H., Del Grande, N. K., Mallett, J. H., and Hubbell, J. H., (1969) Compilation of x-ray cross sections III: U.S. Atom. Energ. Comm. UCRL–50174.Google Scholar
Motschi, H., (1984) Correlation of EPR parameters with thermodynamic stability constants for copper(II) complexes. Copper(II)-EPR as a probe for the surface complexation at the oxide/water interface: Colloids Surf. 9, 333–347.CrossRefGoogle Scholar
Motschi, H., (1987) Aspects of the molecular structure in surface complexes; spectroscopic investigations: in Aquatic Surface Chemistry, Stumm, W., ed., Wiley-Interscience, New York, 111–125.Google Scholar
Mustre de Leon, J., Rehr, J. J., and Zabinsky, S. I., (1991) Ab initio curved-waved x-ray-absorption fine structure: Phys. Rev. B44, 4146–4156.CrossRefGoogle Scholar
O'Day, P. A., (1992) Structure, bonding, and site preference of cobalt(II) sorption complexes on kaolinite and quartz from solution and spectroscopic studies: Doctoral thesis, Stanford University, Stanford, California, 208 pp.Google Scholar
O'Day, P. A., Brown, G. E. Jr., and Parks, G. A., (1991) EXAFS study of aqueous Co(II) sorption complexes on kaolinite and quartz surfaces: in X-ray Absorption Fine Structure, Hasnain, S. S., ed., Ellis Horwood Ltd., London, 260–262.Google Scholar
O'Day, P. A., Brown, G. E. Jr., and Parks, G. A., (1994a) X-ray absorption spectroscopy of cobalt(II) multinuclear surface complexes and surface precipitates on kaolinite: J. Colloid Interface Sci., in press.Google Scholar
O'Day, P. A., Rehr, J. J., Zabinsky, S. I., and Brown, G. E. Jr. 1994b() Extended X-ray absorption fine structure (EXAFS) analysis of disorder and multiple-scattering in complex crystalline solids: J. Amer. Chem. Soc., in press.Google Scholar
Parfitt, R. L., (1978) Anion adsorption by soils and soil materials: Adv. Agron. 30, 1–50.Google Scholar
Rehr, J. J., and Albers, R. C., (1990) Scattering-matrix formulation of curved-wave multiple-scattering theory: Application to X-ray-absorption fine structure: Phys. Rev. B41, 8139–8149.CrossRefGoogle Scholar
Rehr, J. J., Albers, R. C., and Zabinsky, S. I., (1992) High-order multiple-scattering calculations of X-ray-absorption fine structure: Phys. Rev. Lett. 69, 3937–3400.CrossRefGoogle ScholarPubMed
Rehr, J. J., Mustre de Leon, J., Zabinsky, S. I., and Albers, R. C., (1991) Theoretical X-ray absorption fine structure standards: J. Amer. Chem. Soc. 113, 5135–5140.CrossRefGoogle Scholar
Report on the international workshops on standards and criteria in XAFS (): in X-ray Absorption Fine Structure, Hasnain, S. S., 1991 ed., Ellis Horwood Ltd., London, 751–770.Google Scholar
Riese, A. C., (1982) Adsorption of radium and thorium onto quartz and kaolinite: A comparison of solution/surface equilibria models: Doctoral thesis, Colorado School of Mines, Golden, Colorado, 210 pp.Google Scholar
Roe, A. L., Hayes, K. F., Chisholm-Brause, C. J., Brown, G. E. Jr., Parks, G. A., and Leckie, J. O., (1991) X-ray absorption study of lead complexes at α-FeOOH/water interfaces: Langmuir 7, 367–373.CrossRefGoogle Scholar
Sayers, D. E., and Bunker, B. A., (1988) Data analysis: in X-ray Absorption: Principles, Applications, Techniques of EXAFS, SEXAFS, and XANES, Koningsberger, D. C., and Prins, R., eds., Chemical Analysis 92, John Wiley & Sons, New York, 211–253.Google Scholar
Sayers, D. E., Stern, E. A., and Lytle, F. W., (1971) New technique for investigating noncrystalline structures Fourier analysis of the Extended X-ray-Absorption Fine Structure: Phys. Rev. Lett. 27, 1204–1207.CrossRefGoogle Scholar
Schenk, C. V., Dillard, J. G., and Murray, J. W., (1983) Surface analysis and the adsorption of Co(II) on goethite: J. Colloid Interface Sci. 95, 398–409.CrossRefGoogle Scholar
Schindler, P. W., Liechti, P., and Westall, J. C., (1987) Adsorption of copper, cadmium, and lead from aqueous solution to the kaolinite/water interface: Neth. J. Agri. Sci. 35, 219–230.Google Scholar
Schindler, P. W., and Stumm, W., (1987) The surface chemistry of oxides, hydroxides, and oxide minerals: in Aquatic Surface Chemistry, Stumm, W., ed., Wiley-Interscience, New York, 83–110.Google Scholar
Schofield, R. K., and Samson, H. R., (1954) Flocculation of kaolinite due to the attraction of oppositely charged crystal faces: Faraday Soc. Diss. 18, 135–145.CrossRefGoogle Scholar
Singh, S. P. N., and Mattigod, S. V., (1992) Modeling boron adsorption on kaolinite: Clays & Clay Minerals 40, 192–205.CrossRefGoogle Scholar
Sposito, G., (1984) The Surface Chemistry of Soils: Oxford University Press, New York, 234 pp.Google Scholar
Sposito, G., (1989) The Chemistry of Soils: Oxford University Press, New York, 277 pp.Google Scholar
Stern, E. A., (1988) Theory of EXAFS: in X-ray Absorption: Principles, Applications, Techniques of EXAFS, SEXAFS, and XANES, Koningsberger, D. C., and Prins, R., eds., Chemical Analysis 92, John Wiley & Sons, New York, 3–51.Google Scholar
Stern, E. A., Sayers, D. E., and Lytle, F. W., (1975) Extended X-ray absorption fine structure technique. III. Determination of physical parameters: Phys. Rev. B11, 4836–4846.CrossRefGoogle Scholar
Stumm, W., 1987 ed. () Aquatic Surface Chemistry: Wiley-Interscience, New York, 520 pp.Google Scholar
Stumm, W., (1992) Chemistry of the Solid-Water Interface: Wiley-Interscience, New York, 428 pp.Google Scholar
Talibudeen, O., (1981) Cation exchange in soils: in The Chemistry of Soil Processes, Greenland, D. J., and Hayes, M. H. B., eds., John Wiley & Sons, New York, 115–177.Google Scholar
Talibudeen, O., and Goulding, K. W. T., (1983) Apparent charge heterogeneity in kaolins in relation to their 2: 1 phyllosilicate content: Clays & Clay Minerals 31, 137–142.CrossRefGoogle Scholar
Teo, B.-K., (1986) EXAFS: Basic Principles and Data Analysis. Inorganic Chemistry Concepts 9, Springer-Verlag, Berlin, 349 pp.CrossRefGoogle Scholar
Teo, B.-K., and Joy, D. C., 1981 eds. () EXAFS Spectroscopy, Plenum Press, New York, 275 pp.CrossRefGoogle Scholar
Tewari, P. H., Campbell, A. B., and Lee, W., (1972) Adsorption of Co2+ by oxides from aqueous solution: Can. J. Chem. 50, 1642–1648.CrossRefGoogle Scholar
Tewari, P. H., and Lee, W., (1975) Adsorption of Co(II) at the oxide-water interface. J. Colloid Interface Sci. 52, 77–88.CrossRefGoogle Scholar
Tewari, P. H., and McIntyre, N. S., (1975) Characterization of adsorbed Co(II) at the oxide-water interface: AICHE Symposium Series 71(150), 134–137.Google Scholar
van Olphen, H., (1977) In Introduction to Clay Colloid Chemistry, 2nd ed.: Wiley-Interscience, New York, 301 pp.Google Scholar
Waychunas, G. A., and Brown, G. E. Jr. 1990() Polarized X-ray absorption spectroscopy of metal ions in minerals: Identification of near-edge electronic transitions and scattering resonances and application to site geometry determinations: Phys. Chem. Minerals 17, 420–430.CrossRefGoogle Scholar
Waychunas, G. A., Brown, G. E. Jr., and Apted, M. A., (1983) X-ray K-edge absorption spectra of Fe minerals and model compounds: Near-edge structure: Phys. Chem. Minerals 9, 212–215.CrossRefGoogle Scholar
Wieland, E., and Stumm, W., (1992) Dissolution kinetics of kaolinite in acidic aqueous solutions at 25°C: Geochim. Cosmochim. Acta 56, 3339–3355.CrossRefGoogle Scholar
Winick, H., and Doniach, S., 1980 eds. () Synchrotron Radiation Research: Plenum Press, New York, 680 pp.CrossRefGoogle Scholar
Xie, Z., and Walther, J. V., (1992) Incongruent dissolution and surface area of kaolinite: Geochim. Cosmochim. Acta 56, 3357–3363.CrossRefGoogle Scholar
Young, R. A., and Hewat, A. W., (1988) Verification of the triclinic crystal structure of kaolinite: Clays & Clay Minerals 36, 225–232.CrossRefGoogle Scholar
Zachara, J. M., Cowan, C. E., Schmidt, R. L., and Ainsworth, C. C., (1988) Chromate adsorption by kaolinite: Clays & Clay Minerals 36, 317–326.CrossRefGoogle Scholar
Zachara, J. M., Resch, C. T., and Smith, S. C., (1994) Influence of humic substances on Co2+ sorption by a subsurface mineral separate and its mineralogical components: Geochim. Cosmochim. Acta 58, 553–566.CrossRefGoogle Scholar