Mercury-DOC Interactions: Binding Constants

- The strength of interactions between Hg and DOC (measured as binding constants) is important in the determination of mercury speciation.

- Binding constants, determined by ion-exchange resins, were highest for DOC isolates from theF1 site.

- DOC binds Hg more strongly than some of the strongest binding model ligands (e.g., EDTA, mercaptoacetic acid).

- Strong interactions between mercury and DOC appear to be a result of Hg binding at reduced sulfur sites in organic matter.