Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-15T15:19:11.506Z Has data issue: false hasContentIssue false

Effects of Humic Acid on the Crystallization of Aluminum Hydroxides

Published online by Cambridge University Press:  02 April 2024

A. Singer*
Affiliation:
Department of Soil Science, University of Saskatchewan Saskatoon, Saskatchewan, Canada S7N 0W0
P. M. Huang
Affiliation:
Department of Soil Science, University of Saskatchewan Saskatoon, Saskatchewan, Canada S7N 0W0
*
2Permanent address: Seagram Center for Soil and Water Sciences, The Faculty of Agriculture, The Hebrew University of Jerusalem, Rehovot, Israel.
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.

The effects of humic acid (HA) on the crystallization of precipitation products of Al under mildly acidic to alkaline conditions were investigated. The extent of Al precipitation substantially decreased with increasing HA concentration (0 to 75 µg/ml) in the pH range 6 to 10 during the 80-day aging period. The X-ray powder diffraction (XRD) data show that, at pH 6.0, the amount of pseudoboehmite formed in the systems decreased with the increasing concentration of HA present. The proportion of Al hydroxide polymorphs (gibbsite and bayerite) was greatly influenced by the amounts of HA present in the systems. At pH 6.0 and HA concentration of 37.5 µg/ml, all the precipitation products of Al were noncrystalline. At pH 8.0 and a HA concentration of 12.5 µg/ml, the formation of gibbsite and bayerite was completely inhibited and only pseudoboehmite was evident in the XRD patterns. Further increase in HA concentration (25–75 µg/ml HA) at pH 8.0 resulted in no precipitation of Al, and only a broad peak at ∼3.3 Å, characteristic of HA, was observed. The XRD patterns of the precipitates of Al formed in the absence of HA at pH 10.0 showed the characteristic peaks of bayerite. At pH 10.0, the precipitation products of Al formed even at the HA concentration of 2.5 µg/ml yielded no XRD peaks. Infrared absorption spectra and transmission electron micrographs of the precipitation products of Al formed in the systems studied substantiate the findings obtained by XRD. The data obtained in this study indicate that HA affects the formation of Al hydroxide polymorphs, pseudoboehmites and short-range ordered mineral colloids.

Type
Research Article
Copyright
Copyright © 1990, The Clay Minerals Society

Footnotes

1

Contribution No. R.617 Saskatchewan Institute of Pedology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.

References

Aiken, G. R., Aiken, G. R., McKnight, D. M., Wershaw, R. L. and MacCarthy, P., 1985 Isolation and concentration techniques for aquatic humic substances Humic Substances in Soil, Sediment, and Water New York Wiley 363385.Google Scholar
Bamhisel, R. I. and Rich, C. I., 1965 Gibbsite, bayerite and nordstrandite formation as affected by anions, pH and mineral surfaces Soil Sci. Soc. Amer. Proc. 29 531534.CrossRefGoogle Scholar
Hayes, MHB, Aiken, G. R., McKnight, D. M., Wershaw, R. L. and MacCarthy, P., 1985 Extraction of humic substances from soil Humic Substances from Soil, Sediment, and Water New York Wiley 329362.Google Scholar
Hsu, P. H., 1966 Formation of gibbsite from aging hydroxy aluminum solutions Soil Sci. Soc. Amer. Proc. 30 173176.CrossRefGoogle Scholar
Hsu, P. H., Dixon, J. B. and Weed, S. B., 1977 Aluminum hydroxides and oxyhydroxides Minerals in Soil Environments Wisconsin Soil Science Society of America, Madison 99143.Google Scholar
Huang, P. M., Violante, A., Huang, P. M. and Schnitzer, M., 1986 Influence of organic acids on crystallization and surface properties of precipitation products of aluminum Interactions of Soil Minerals with Natural Organics and Microbes Wisconsin Soil Science Society of America, Madison 159221.CrossRefGoogle Scholar
Kodama, H. and Schnitzer, M., 1980 Effect of fulvic acid on the crystallization of aluminum hydroxides Geoderma 24 195205.CrossRefGoogle Scholar
Kwong, N K K F and Huang, P. M., 1975 Influence of citric acid on the crystallization of aluminum hydroxides Clays & Clay Minerals 23 164165.CrossRefGoogle Scholar
Kwong, N K K F and Huang, P. M., 1977 Influence of citric acid on the hydrolytic reactions of aluminum Soil Sci. Soc. Amer. J. 41 692697.CrossRefGoogle Scholar
Kwong, N K KF and Huang, P.M., 1979 Therelative influence of low-molecular-weight, complexing organic acids on the hydrolysis and precipitation of aluminum Soil Sci. 128 337342.CrossRefGoogle Scholar
Kwong, N K K F Huang, P. M., Mortland, M. M. and Farmer, V. C., 1979 Nature of hydrolytic precipitation products of aluminum as influenced by low molecular weight complexing organic acids Proc. 6th Int. Clay Conf, Oxford, 1979 Amsterdam Elsevier 527536.Google Scholar
Kwong, N K K F and Huang, P. M., 1981 Comparison of the influence of tannic acid and selected low molecular weight organic acids on precipitation products of aluminum Geoderma 26 179193.CrossRefGoogle Scholar
Leenheer, J. A., Aiken, G. R., McKnight, D. M., Wershaw, R. L. and MacCarthy, P., 1985 Fractionation techniques for aquatic humic substances Humic Substances in Soil, Sediment, and Water New York Wiley 409429.Google Scholar
Schnitzer, M., Huang, P. M. and Schnitzer, M., 1986 Binding of humic substances by soil mineral colloids Interactions of Soil Minerals with Natural Organics and Microbes Wisconsin Soil Science Society of America, Madison 78102.Google Scholar
Stevenson, F. J., Aiken, G. R., McKnight, D. M., Wershaw, R. L. and MacCarthy, P., 1985 Geochemistry of soil humic substances Humic Substances in Soil, Sediment, and Water New York Wiley 1352.Google Scholar
Swift, R. S., Aiken, G. R., McKnight, D. M., Wershaw, R. L. and MacCarthy, P., 1985 Fractionation of soil humic substances Humic Substances in Soil, Sediment, and Water New York Wiley 387408.Google Scholar
Tettenhorst, R. and Hofmann, D. A., 1980 Crystal chemistry ofboehmite Clays & Clay Minerals 28 373380.CrossRefGoogle Scholar
Tiessen, H., Bettany, J. R. and Stewart, J. W. B., 1981 An improved method for the determination of carbon in soils and soil extracts by dry combustion Commun. Soil Sci. Pl. Anal. 12 211218.CrossRefGoogle Scholar
Violante, A. and Huang, P. M., 1984 Nature and properties of pseudoboehmite formed in the presence of organic and inorganic ligands Soil Sci. Soc. Amer. J. 48 11931201.CrossRefGoogle Scholar
Violante, A. and Huang, P. M., 1985 Influence of inorganic and organic ligands on the formation of aluminum hydroxides and oxyhydroxides Clays & Clay Minerals 33 181192.CrossRefGoogle Scholar
Violante, A. and Violante, P., 1980 Influence of pH, concentration, and chelating power of organic anions on the synthesis of aluminum hydroxides and oxyhydroxides Clays & Clay Minerals 28 425434.CrossRefGoogle Scholar