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The aqueous geochemistry of metals in the weathering environment: strengths and weaknesses in our understanding of speciation and process

Published online by Cambridge University Press:  05 July 2018

C. D. Curtis
C. D. Curtis*
Affiliation:
University of Manchester Environment Centre and Department of Earth Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK
*
E-mail: [email protected]
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Abstract

Soil profiles developed in different climates and physical settings are highly variable in structure, in mineralogy, in the local biosphere and in the compositions of the soil gas and water phases. Discussion of metals in ‘the weathering environment’ needs to acknowledge and address this diversity.

The thermochemical methods developed by Pourbaix (1949) and Garrels and Christ (1965) remain useful predictors of metal speciation and solubility but the approach is valid only for processes involving carbonates, sulphides, hydroxides and similar minerals in soils and sediments. Almost no primary silicates are thermodynamically stable: they spontaneously decompose to non-equilibrium solid products with metal release determined by kinetics.

Hydrolysis constants for aquo-complexes are useful indicators of metal speciation, mobility and availability. Recent work on soluble soil organic matter confirms that the active ligands are overwhelmingly oxygen based: phenols, carboxylic acids, alcohols. Many of these molecules compete very effectively with aquo-complexes to form strong metal chelates and appear to be responsible for substantial Al and Fe mobilization within and translocation down soil profiles.

It is important to note also that strong clay mineral/organic matter associations (clay-organic complex) will fix metals as a consequence of the same chelation reactions (in this case removing them from solution - retardation).

Keywords

metalsspeciationthermodynamic stabilityaqueous complexesorganic complexes.
Type
Research Article
Information
Mineralogical Magazine , Volume 67 , Issue 2 , April 2003 , pp. 235 - 246
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2003

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References

Boult, S., Jugdaohsingh, R., White, K., Smith, B. and Powell, J. (2001) Evidence that polysaccharide and humic and fulvic acids are co-extracted during analysis but have different roles in the chemistry of natural waters. Applied Geochemistry, 16, 1261—1267.CrossRefGoogle Scholar
Bunting, B.T., (1969) The Geography of Soil. Hutchinson & Co., London, 213 pp.Google Scholar
Campbell, P.G.C. (1995) Interactions between trace metals and aquatic organisms: a critique of the free ion activity model. Pp. 45—102 in: Metal Speciation and Bioavailability in Aquatic Systems (Tessier, R. and Turner, D.R., editors). Wiley, Chichester, UK.Google Scholar
Cotter-Howells, J.D. (1996) Formation of lead phosphate in soil. Environmental Pollution, 93, 9—16.CrossRefGoogle Scholar
Cotter-Howells, J.D. and Paterson, E. (2000) Minerals and soil development. Pp. 91—124 in Environmental Mineralogy (Vaughan, D.J. and Wogelius, R.A., editors). EMU Notes in Mineralogy, 2. European Mineralogical Union, Eotvos University Press, Budapest.Google Scholar
Cotter-Howells, J.D. and Thornton, I. (1991) Sources and pathways of environmental lead to children in a Derbyshire mining village. Environmental Geochemistry and Health, 12, 127—135.CrossRefGoogle Scholar
Drever, J.I. (1997) The Geochemistry of Natural Waters: Surface and Groundwater Environments, 3rd edition. Prentice Hall, New Jersey, 436 pp.Google Scholar
Faure, G. (1998) Principles and Applications of Geochemistry, 2nd edition. Prentice Hall, New Jersey, 600 pp.Google Scholar
Garrels, R.M. and Christ, C.L. (1965) Solutions, Minerals and Equilibria. W.H. Freeman, San Francisco, 450 pp.Google Scholar
Garrels, R.M. and Mackenzie, F.T. (1971) Evolution of Sedimentary Rocks. W.W. Norton, New York, 397 pp.Google Scholar
Hill, D.M. and Aplin, A.C. (1996) Role of colloids as carriers of metals in river waters. Pp. 534—536 in: 4th International Symposium on the Geochemistry of the Earth’s Surface (IAGC) (Bottrell, S.H., editor), University of Leeds, UK.Google Scholar
Huheey, J.E. (1983) Inorganic Chemistry, 3rd edition. Harper International, 936 pp.Google Scholar
Jenny, H. (1941) Factors of Soil Formation: A System of Quantitative Pedology. McGraw Hill, New York.CrossRefGoogle Scholar
Johnson, D.A. (1968) Some Thermodynamic Aspects of Inorganic Chemistry. Cambridge University Press, Cambridge, UK.Google Scholar
Kerven, B. (1995) Chromatographic techniques for the separation of Al and associated ligands present in soil solution. Plant Soil, 171, 29—34.CrossRefGoogle Scholar
Krauskopf, K.B. (1979) Introduction to Geochemistry, 2nd edition. McGraw Hill, New York. 617 pp.Google Scholar
F., Lippmann (1981) The thermodynamic status of clay minerals. Pp. 475—486 in: Proceedings of the International Clay Conference 1981 (van Olphen, H. and Veniale, F., editors). Elsevier, Amsterdam.Google Scholar
Livingstone, D.A. (1963) Chemical composition of rivers and lakes. In Data of Geochemistry, 6th edition (Fleischer, M., editor). USGS Professional Paper 440-G.CrossRefGoogle Scholar
Malinina, M.S., Motuzova, G.V. and Karavanova, E.I. (1996) Effects of organic matter on Hg migration in soils in different geochemical situations. Pp. 424—428 in: 4th International Symposium on the Geochemistry of the Earth's Surface (IAGC) (Bottrell, S.H., editor). University of Leeds, UK.Google Scholar
Nordstrom, K.D. and May, H.M. (1996) Aqueous equilibrium data for mononuclear aluminium species. Pp. 39—80 in: The Environmental Chemistry of Aluminium (Sposito, G., editor). CRC Press, Lewis Publishers, New York.Google Scholar
Pourbaix, M.J.N. (1949) Thermodynamics of Dilute Aqueous Solutions. E. Arnold, London.Google Scholar
Rainbow, P.S. (1995) Physiology, physicochemistry and metal uptake — a crustacean perspective. Marine Pollution Bulletin, 31, 55—59.CrossRefGoogle Scholar
Strakhov, N. (1987) Principles of Lithogenesis, Vol. 1. (translated by Fitzsimmons, J.P.). Oliver & Boyd, Edinburgh.Google Scholar
Ugolini, F.C. and Spaltenstein, H. (1992) Pedosphere. Pp. 123—148 in: Global Biogeochemical Cycles (Butcher, S.S., Charlson, R.J., Orians, G.H. and Wolfe, G.V., editors). Academic Press, New York, 379 pp.CrossRefGoogle Scholar
Valsami-Jones, E., Ragnarsdottir, K.V., Mann, T. and Kemp, A.J. (1996) An experimental investigation of the potential of apatite as a radioactive and industrial waste scavenger. Pp. 686—689 in: 4th International Symposium on the Geochemistry of the Earth's Surface (IAGC) (Bottrell, S.H., editor). University of Leeds, UK.Google Scholar
Vance, G.F., Stevenson, F.J. and Sikora, F.J. (1996) Environmental chemistry of aluminium-organic complexes. Pp. 169—220 in: The Environmental Chemistry of Aluminium (G. Sposito, editor). CRC Press, Lewis Publishers, New York. S12Google Scholar