This work was supported by US-EPA Interagency Agreement # DW 14936802-01-0, and the USGS-South Florida Ecosystem Initiative Program. Assistance in sample collection by the South Florida Water Management District, in particular Larry Fink and Pete Rawlik, is gratefully acknowledged. Special thanks to Paul Schuster, Janece Koleis and Jason Tregellas (USGS, Boulder, CO) for their assistance in sample collection and processing.
This paper was publised in the Environmental Science & Technology, 1998, Volume 32, No. 21, pp. 3305-3311. This paper was also cited under RESEARCH WATCH page 510A, "Dissolution of cinnabar by DOM - Dissolved organic matter (DOM) interacts with cations in natural waters and soils and affects solubility, mobility, and toxicity of many trace metals. M. Ravichandran and coworkers found that organic matter isolated from the Florida Everglades caused a dramatic increase in mercury release from cinnabar (HgS). Hydrophobic acids dissolved more mercury than hydrophilic acids and other DOM nonacid fractions. Possible mechanisms of dissolutions include surface complexation of mercury and oxidation of surface sulfur species by the organic matter. DOM enhances mercury release from cinnabar under oxic and anoxic conditions. Enhanced cinnabar solubility has geochemical significance: In mercury-contaminated areas and where conditions favor HgS formation, humic substances could enhance mercury mobilization and affect bioavailability."
