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Nature of mixed iron and aluminium gels as affected by Fe/Al molar ratio, pH and citrate

Published online by Cambridge University Press:  09 July 2018

A. Violante ,
C. Colombo ,
G. Cinquegrani ,
P. Adamo  and
P. Violante
A. Violante
Affiliation:
Dipartimento di Scienze Chimico-Agrarie, Università di Napoli Federico 11, 80055 Portici, Italy
C. Colombo
Affiliation:
Dipartimento di Scienze Chimico-Agrarie, Università di Napoli Federico 11, 80055 Portici, Italy
G. Cinquegrani
Affiliation:
Dipartimento di Scienze Chimico-Agrarie, Università di Napoli Federico 11, 80055 Portici, Italy
P. Adamo
Affiliation:
Dipartimento di Scienze Chimico-Agrarie, Università di Napoli Federico 11, 80055 Portici, Italy
P. Violante
Affiliation:
Dipartimento di Scienze Chimico-Agrarie, Università di Napoli Federico 11, 80055 Portici, Italy
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Abstract

The nature and mineralogy of mixed Al and Fe(III) gels (initial Fe/Al molar ratios (Ri) of 1.0 and 2.5) formed at pH values ranging from 4.0 to 10.0, both in the presence and absence of citric acid (citrate/Fe + AI molar ratio (Rcit) of 0.01 and 0.1) and aged for a long period at room temperature and at 50°C have been studied. The complexes showed considerable differences in the mineralogy of the precipitation products. The samples formed at Ri = 1.0 contained ferrihydrite at pH 4.0, ferrihydrite + gibbsite at pH 5.0-7.0, and hematite + Al(OH)3 polymorphs + ferrihydrite at pH 9.0-10.0. The samples formed at Ri = 2.5 had greater quantities of poorly crystallized ferrihydrite. Large amounts of Fe+Al (25-82%) were solubilized from the samples aged for 60 days at 50°C by ammonium oxalate. The addition of increasing concentrations of citrate to the gel suspensions containing equimolar amounts of Fe and AI strongly inhibited the formation of Al(OH)3 polymorphs both at pH 5.0 or 8.5 by promoting the formation of short-range ordered materials. Citrate added initially to Fe-Al solutions (R*cit = 0.1) completely inhibited formation of crystals even after 135 days at 50°C.

Type
Research Article
Information
Clay Minerals , Volume 33 , Issue 3 , September 1998 , pp. 511 - 519
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1998

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References

April, R. & Keller, D. 0990) Mineralogy of the rhizosphere in forest soils of the eastern United States: Mineralogical studies of the rizosphere. Biogeochem. 9, 1–8.Google Scholar
Colombo, C. & Violante, A. (1996) Effect of time and temperature on the chemical composition and crystallization of mixed iron aluminum species. Clays Clay Miner. 44, 113–120.Google Scholar
Cornell, R.M. & Schwertmann, U. (1979) Influence of organic anions on the crystallization of ferrihydrite. Clays Clay Miner. 27, 402–410.CrossRefGoogle Scholar
Gastuche, M.C., Bruggenwert, T. & Mortland, M.M. (1964) Crystallization of mixed iron and aluminum gels. Soil Sci. 98, 281-289.Google Scholar
Goh, T.B., Huang, P.M., Dudas, M.J. & Pawluk, S. (1987) Effect of iron on the nature of precipitation products of aluminum. Can. J. Soil Sci. 67, 135–145.Google Scholar
Hsu, P.H. (1989) Aluminum hydroxides and oxyhydroxides. Pp. 331–378 in: Minerals in Soils Environments. 2nd ed. (Dixon, J.B. & Weed, S.R., editors). Soil Science Society of America, Madison, Wisconsin.Google Scholar
Huang, P.M. & Violante, A. (1986) Influence of organic acids on crystallization and surface properties of precipitation products of aluminum. Pp. 159-22t in: Interaction of Soil Minerals with Natural Organic and Microbes (Huang, P.M. & Schnitzer, M., editors). Soil Science Society of America. Spec. Pub. 17, Madison, Wisconsin.Google Scholar
Loeppert, R.H. (1987) Reaction of iron in calcareous systems. Pp. 689–714 in: Iron in Soils and Clay Minerals (Stucki, J.W. et al., editors). Reidel Publ., Dordrecht, The Netherlands.Google Scholar
Schwertmann, U. (1964) Differenziemng der Eisenoxide des Bodens durch photochemische Extraktion mit saurer Ammoniumoxalat-Lósung. Z. Pjlanzenernähr. Bodenk. 105, 194–202.CrossRefGoogle Scholar
Schwertmann, U. & Taylor, R.M. (1989) Iron oxides. Pp. 331–378 in: Minerals in Soils Environments. 2nd ed. (Dixon, J.B. & Weed, S.R., editors). Soil Science Society of America, Madison, Wisconsin.Google Scholar
Singh, S.S. & Kodama, H. (1994) Effect of the presence of aluminum ions in iron solutions on the formation of iron oxyhydroxides (FeOOH) at room temperature under acidic environment. Clays Clay Miner. 42, 606–613.Google Scholar
Vance, G.F., Stevenson, F.J. & Sikra, F.J. (1996) Environmental chemistry of aluminum-organic complexes. Pp.169–220 in: The Environmental Chemistry of Aluminum (Sposito, G., editor). CRC Press, Lewis Publishers, Boca Raton, FL.Google Scholar
Violante, A. & Gianfreda, L. (1995) Adsorption of phosphate on variable charge minerals: Competitive effects of organic ligands. Pp. 29–37 in: Environmental Impacts of Soil Component Interactions. Vol. H. Metals, Other lnorganics, and Microbial Activities. (Huang, P.M. et al., editors). CRC Press, Lewis Publishers, Boca Raton, FL.Google Scholar
Violante, A., Gianfreda, L. & Violante, P. (1993) Effect of prolonged ageing on the transformation of shortrange ordered aluminum precipitation products formed in the presence of organic and inorganic iigands. Clays Clay Miner. 41, 353–359.CrossRefGoogle Scholar
Violante, A. & Huang, P.M. (1985) Influence of inorganic and organic ligands on precipitation products of aluminum. Clays Clay Miner. 33, 181–192.Google Scholar