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Crystallization of the (Cd,Ca)CO3 solid solution in double diffusion systems: the partitioning behaviour of Cd2+ in calcite at different supersaturation rates

Published online by Cambridge University Press:  05 July 2018

D. Katsikopoulos*
Affiliation:
Departamento de Geología, Universidad de Oviedo, 33005-Oviedo, Spain
Á. Fernandez-Gonzalez
Affiliation:
Departamento de Geología, Universidad de Oviedo, 33005-Oviedo, Spain
M. Prieto
Affiliation:
Departamento de Geología, Universidad de Oviedo, 33005-Oviedo, Spain
*

Abstract

Considering an ideal solid solution, the partitioning of cadmium in calcite was studied at different levels of supersaturation (δ) using counter-diffusion experiments. The effective (non-equilibrium) distribution coefficients of Cd2+ in calcite (DCd), varied between 20 and 100 depending on the initial concentration of reactants and the evolution of supersaturation. A function that relates the DCd with the supersaturation at nucleation was derived: logDCd= —0.40logδ + 2.42. The relationship obtained suggests that in naturalwaters, Cd2+ can be incorporated to a greater degree in calcite when the solid solution-aqueous solutions system is near to equilibrium, which can occur in scenarios where the supersaturation rate and hence the supersaturation level are relatively small.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2008

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References

Andara, A., Heasman, D.M., Fernandez-González, A. and Prieto, M. (2005) Characterization and crystallization of Ba(SO4,SeO4) solid solution. Crystal Growth and Design, 5, 1371–1378.CrossRefGoogle Scholar
Astilleros, J.M., Pina, CM., Fernandez-Diaz, L. and Putnis, A. (2003) Supersaturation functions in binary solid solution-aqueous solution systems. Geochimica et Cosmochimica Acta, 67, 1601–1608.CrossRefGoogle Scholar
Chiarello, R.P., Sturchio, N.C., Grace, J.D., Geissbuhler, P., Sorensen, L.B., Cheng, L., and Xu, S. (1997) Otavite-calcite solid-solution formation at the calcite-water interface studied in situ by synchrotron X-ray scattering. Geochimica et Cosmochimica Acta, 61, 1467–1474.CrossRefGoogle Scholar
Glynn, P.D. and Reardon, EJ. (1990) Solid-solution aqueous solution equilibria: thermodynamic theory and representation. American Journal of Science, 290, 164–201.CrossRefGoogle Scholar
Königsberger, E., Hausner, R. and Gamsjaeger, H. (1991) Solid-solute phase equilibria in aqueous solution. V: The system cadmium carbonate-calcium carbonate-carbon dioxide-water. Geochimica et Cosmochimica Acta, 55, 3505–3514.CrossRefGoogle Scholar
Parkhurst, D.L. and Appelo, C.A.J. (1999) User's guide to PHREEQC (Version 2) - A computer program for speciation, batch-reaction, one-dimensional transport and inverse geochemical calculations. US Geological Survey Water Resources Investigations Report 99–4259. U. S. Geological Survey, Denver, 312 pp.Google Scholar
Pina, CM. and Putnis, A. (2002) The kinetics of nucleation of solid solutions from aqueous solutions: a new model for calculating non-equilibrium distribution coefficients. Geochimica et Cosmochimica Acta, 66, 185–192.CrossRefGoogle Scholar
Prieto, M., Putnis, A., Fernandez-Diaz, L. and Lopez-Andres, S. (1994) Metastability in diffusing-reacting systems. Journal of Crystal Growth, 142, 225–235.CrossRefGoogle Scholar
Prieto, M., Cubillas, P. and Fernandez-Gonzalez, A. (2003) Uptake of dissolved Cd by biogenic and abiogenic aragonite: a comparison with sorption onto calcite. Geochimica et Cosmochimica Acta, 67, 3859–3869.CrossRefGoogle Scholar
Prieto, M., Astilleros, J.M., Pina, CM., Fernandez-Diaz, L. and Putnis, A. (2007) Comment: supersaturation in binary solid solution-aqueous solution systems. American Journal of Science, 307, 1034–1045.CrossRefGoogle Scholar
Stipp, S.L., Parks, G., Nordstrom, K. and Leckie, J. (1993) Solubility-product constant and thermodynamic properties for synthetic otavite, CdCO3(s), and aqueous association constants for the CA(1\)-CO2-H2O system. Geochimica et Cosmochimica Acta, 57, 2699–2713.CrossRefGoogle Scholar