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Goethite Dispersibility in Solutions of Variable Ionic Strength and Soluble Organic Matter Content

Published online by Cambridge University Press:  28 February 2024

A. C. Herrera Ramos*
Affiliation:
Department of Soil, Crop & Atmospheric Sciences, Cornell University, Ithaca, New York 14853
M. B. McBride
Affiliation:
Department of Soil, Crop & Atmospheric Sciences, Cornell University, Ithaca, New York 14853
*
1Present address: 36 avenida 11–91, zona 5, Jardines de la Asuncion; Guatemala City, Guatemala.
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Abstract

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The degree of flocculation of aqueous suspensions of microcrystalline goethite was measured in salts of monovalent, divalent and trivalent cations at pH 6.0–6.5 over a range of ionic strengths using light scattering measurements at 650 nm. Varying concentrations of soluble humic material as well as the organic ligands, salicylate and citrate, were tested for their effect on flocculation. It was found that KCl and NaCl induced flocculation at lower ionic strength than CaCl2, while AlCl3 favored dispersion at all ionic strengths tested. The simple organic ligands promoted flocculation at low concentration, with citrate having a more pronounced effect than salicylate. At higher concentrations, these ligands reversed their effect, inducing a more dispersed state of the oxide. The organic ligand effect on dispersibility was modified by the particular metal cation present, with Ca2+ being more conducive to flocculation than K+. Soluble humic materials affected goethite flocculation in a qualitatively similar way to that of the simple organic ligands, that is low concentrations favored flocculation while high concentrations induced dispersion. This dispersing effect was partially suppressed by the presence of Ca2+, and completely suppressed by Al3+. Thus, soluble humic substances at relatively high concentrations appear to have a marked dispersing effect on goethite in the absence of polyvalent cations, and a strongly flocculating effect in their presence.

The results can be explained qualitatively by a simple oxide surface charge model, in which chemi-sorption of multivalent cations or organic ligands alters the surface charge. Reactions that increase the magnitude of positive or negative surface charge favor dispersion, while those that reduce the magnitude of charge favor flocculation.

Type
Research Article
Copyright
Copyright © 1996, The Clay Minerals Society

References

Atkinson, R.J., Posner, A.M. and Quirk, J.P.. 1967. Adsorption of potential-determining ions at the ferric oxide-aqueous electrolyte interface. J Phys Chem 71: 550555.CrossRefGoogle Scholar
Bartoli, F., Burtin, G. and Guerif, J.. 1992. Influence of organic matter on aggregation in Oxisols rich in gibbsite or in goethite. II. Clay dispersion, aggregation strength, and water-stability. Geoderma 54: 259274.CrossRefGoogle Scholar
Biber, M.V. and Stumm, W.. 1994. An in-situ ATR-FTIR study, the surface coordination of salicylic acid on aluminum and iron (III) oxides. Environ Sci Technol 28: 763768.CrossRefGoogle Scholar
Cornell, R.M. and Schindler, P.W.. 1980. Infrared study of the adsorption of hydroxycarboxylic acids on α-FeOOH and amorphous Fe(III) hydroxide. Colloid & Polymer Sci 258: 11711175.CrossRefGoogle Scholar
Davis, J.A.. 1982. Adsorption of natural dissolved organic matter at the oxide/water interface. Geochim et Cosmochim Acta 46: 23812393.CrossRefGoogle Scholar
Fontes, M.P.F., Alvarenga, R.C., Gjorup, G.B. and Nascif, P.S.. 1992a. Influence of calcium salts and mechanical stresses in the water dispersible clay (WDC) of Brazilian oxisols. Agron Abstr p. 370.Google Scholar
Fontes, M.R., Weed, S.B. and Bowen, L.H.. 1992b. Association of microcrystalline goethite and humic acid in some oxisols from Brazil. Soil Sci Soc Am J 56: 982990.CrossRefGoogle Scholar
Greenberg, A.E., Trussell, R.R. and Clesceri, L.S.. 1992. Standard methods for the examination of water and wastewater, including bottom sediment and sludges. American Public Health Association, American Water Works Association. New York: Water Pollution Central Federation. p. 16.Google Scholar
Gu, B. and Doner, H.E.. 1993. Dispersion and aggregation of soils as influenced by organic and inorganic polymers. Soil Sci Soc Am J 57: 709716.CrossRefGoogle Scholar
Gu, B., Schmidt, J., Chen, Z., Liang, L. and McCarthy, J.F.. 1994. Adsorption and desorption of natural organic matter on iron oxide, mechanisms and models. Environ Sci Technol 28: 3846.CrossRefGoogle ScholarPubMed
Huang, C.P. and Stumm, W.. 1973. Specific adsorption of cations on hydrous γ-Al2O3. J Colloid Int Sci 43: 409420.CrossRefGoogle Scholar
Liang, L. and Morgan, J.J.. 1990. Chemical aspects of iron oxide coagulation in water, laboratory studies and implications for natural systems. Aquatic Sci 52: 3255.CrossRefGoogle Scholar
Lumsdon, D.G. and Evans, L.J.. 1994. Surface complexation model parameters for goethite (α-FeOOH). J Colloid Int Sci 164: 119125.CrossRefGoogle Scholar
Muneer, M. and Oades, J.M.. 1989. The role of Ca-organic interactions in soil aggregate stability. III. Mechanisms and models. Australian J Soil Research 27: 411423.CrossRefGoogle Scholar
Oades, J.M.. 1989. An introduction to organic matter in mineral soils. In: Dixon, J.B., Weed, S.B., editors. Minerals In Soil Environments. 2nd ed. Madison, WI: Soil Sci Soc Am. p. 89159.Google Scholar
O'Melia, C.R.. 1987. Particle-particle interactions. In: Stumm, W., editor. Aquatic Surface Chemistry. New York: John Wiley) and Sons. p. 385403.Google Scholar
Ong, H.L. and Bisque, R.E.. 1968. Coagulation of humic colloids by metal ions. Soil Sci 106: 220224.CrossRefGoogle Scholar
Peng, F.F. and Di, P.. 1994. Effect of multivalent salts-calcium and aluminum on the flocculation of kaolin suspension with anionic polyacrylamide. J Colloid Int Sci 164: 229237.CrossRefGoogle Scholar
Quirk, J.P. and Aylmore, L.A.G.. 1971. Domains and quasi-crystalline regions in clay systems. Soil Sci Soc Am Proc 35: 652654.CrossRefGoogle Scholar
Sholkovitz, E.R.. 1976. Flocculation of dissolved organic and inorganic matter during the mixing of river water and sea-water. Geochim Cosmochim Acta 40: 831.CrossRefGoogle Scholar
Sletten, R.S. and Benjamin, M.M.. 1994. Mobilization of Fe- and Al-hydroxides by fulvic and humic acids. Agron Abstr p. 256.Google Scholar
Steel, R.G.D. and Torrie, J.H.. 1980. Principles and Procedures of Statistics. 2nd ed. New York: McGraw-Hill. 633p.Google Scholar
Stumm, W., Kummert, R. and Sigg, L.. 1980. A ligand exchange model for the adsorption of inorganic and organic ligands at hydrous oxide interfaces. Croatica Chem Acta 53: 291312.Google Scholar
Stumm, W.. 1992. Chemistry of the Solid-Water Interface, Processes at the Mineral-Water and Particle-Water Interface in Natural Systems. New York: J. Wiley and Sons. 428p.Google Scholar
Tipping, E. and Higgins, D.C.. 1982. The effect of adsorbed humic substances on the colloid stability of haematite particles. Colloids & Surfaces 5: 8592.CrossRefGoogle Scholar
van der Marel, H.W. and Beutelspacher, H.. 1976. Atlas of Infrared Spectroscopy of Clay Minerals and their Admixtures. Amsterdam: Elsevier. 396p.Google Scholar
van Olphen, H.. 1977. An Introduction to Clay Colloid Chemistry. 2nd edition. New York: John Wiley and Sons. 318 p.Google Scholar
Wilson, M.J.. 1987. A Handbook of Determinative Methods in Clay Mineralogy. New York: Chapman and Hall. 320p.Google Scholar
Yost, E.C., Tejedor-Tejedor, M.I. and Anderson, M.A.. 1990. In situ CIR-FTIR characterization of salicylate complexes at the goethite/aqueous solution interface. Environ Sci Technol 24: 822828.CrossRefGoogle Scholar