Aluminum Content of Soil Extracts as a Function of pH and Ionic Strength

Abstract

The concentration of aluminum in the soil extract cannot presently be predicted from ion activity product considerations alone. Aluminum concentration in solution can be estimated from pH and ionic strength of a soil extract by the following empirical equations urn:x-wiley:03615995:saj2sssaj197403615995003800060020x:equation:saj2sssaj197403615995003800060020x-math-0001The aluminum concentration in the extracts of several soils were calculated using published data for pH and ionic strength and compared with the experimentally determined values.

Free Energy of Formation of Beidellite from Apparent Solubility Measurements

“…Stability constants have not been derived for polymeric anionic complexes which some investigators (Plumb and Swaine, 1964;Marshall et al, 1973) have postulated may form in the alkaline range. Consideration of the cationic complex, AI6(OH)a~ -(Richbnrg and Adams, 1970), did not change significantly the calculated activity of A1 a + in slightly alkaline soil extracts (Misra et al, 1974). Smith and Hem (1972) concluded that the concentration of measured A1 in dilute solutions, resulting from the aging of aluminum hydroxide complexes, could be assigned to the four simple monomeric species by equilibrium calculations.…”