STRUCTURES AND OCCURRENCE OF TERNARY OXIDE-METAL-LIGAND COMPLEXES

The co-adsorption of metals and organic molecules onto oxide surfaces and the formation of ternary complexes are believed to be common and important processes in soils and aquifers. These reactions may alter the sorptive capacity of the oxide host, modify or reverse its surface charge, and passivate or activate the host with regards to dissolution and other surface-mediated reactions. Modification of the surface chemistry of the oxide host is of geochemical importance because of the roles of these solid phases in moderating the trace-metal compositions of natural waters. Factors that may drive the formation of ternary complexes at oxide-water interfaces will be discussed. A review of case studies in which the structures/compositions of ternary surface complexes have been identified will be presented.