CONDITIONAL FORMATION CONSTANTS FOR ALUMINUM-ORGANIC MATTER COMPLEXES

Abstract

The objective of this study was to determine conditional formation constants which are dependent on pH for Al-organic matter complexes. Potentiometric titrations of H-organic matter in the presence of 0, 0.004 and 0.01 M AlCl3 were carried out by the batch method. The conditional formation constants were calculated by simply relating the amount of complex formed to the amounts of unreacted metal and ligand. The addition of Al3+ resulted in displacement of the titration curves, indicating complex formation. The formation constants (log K′f) increased as the pH increased, illustrating the strong dependence of Al adsorption on pH. Values for log K′f ranged from 1.78 to 3.90 in this study.