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Adsorption of Phosphate by Aluminum and Iron in Soils
Author(s) -
Hsu Pa Ho
Publication year - 1964
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1964.03615995002800040009x
Subject(s) - adsorption , phosphate , chemistry , inorganic chemistry , aluminium , amorphous solid , soil water , nuclear chemistry , environmental chemistry , geology , organic chemistry , soil science
A slightly acid soil was treated with dilute phosphate solutions of pH 7 to study the mechanism of phosphate fixation. Two reactions operating at different rates were recognized. The one which proceeded more rapidly is believed to be due to surface adsorption of phosphate on the amorphous aluminum hydroxides and iron oxides already in this soil. The other, a much slower reaction, is due to the surface adsorption on similar amorphous hydroxides and oxides developed during the experiment. Experimental work showed that the solubilities of variscite, of synthetic Al(OH) 2 H 2 PO 4 , and of synthetic Fe(OH) 2 H 2 PO 4 were considerably increased in the presence of this soil indicating that these compounds are not likely to be the products of fixation under these conditions.