Complexation of trace metals by adsorbed natural organic matter

Geochimica et Cosmochimica Acta



The adsorption behavior and solution speciation of Cu(II) and Cd(II) were studied in model systems containing colloidal alumina particles and dissolved natural organic matter. At equilibrium a significant fraction of the alumina surface was covered by adsorbed organic matter. Cu(II) was partitioned primarily between the surface-bound organic matter and dissolved Cu-organic complexes in the aqueous phase. Complexation of Cu2+ with the functional groups of adsorbed organic matter was stronger than complexation with uncovered alumina surface hydroxyls. It is shown that the complexation of Cu(II) by adsorbed organic matter can be described by an apparent stability constant approximately equal to the value found for solution phase equilibria. In contrast, Cd(II) adsorption was not significantly affected by the presence of organic matter at the surface, due to weak complex formation with the organic ligands. The results demonstrate that general models of trace element partitioning in natural waters must consider the presence of adsorbed organic matter. ?? 1984.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Complexation of trace metals by adsorbed natural organic matter
Series title Geochimica et Cosmochimica Acta
DOI 10.1016/0016-7037(84)90095-4
Volume 48
Issue 4
Year Published 1984
Language English
Contributing office(s) Toxic Substances Hydrology Program
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Geochimica et Cosmochimica Acta
First page 679
Last page 691