The chemical form in which mercury exists in water is its speciation. Mercury species are distinguishable from one another, stoichiometrically, and with respect to their bioavailability. In addition, mercury can exist in different phases, for example, as gaseous species, as solid phases, or in adsorbed states. Chemical speciation is central to the equilibrium, kinetic, and biogeochemical aspects of mercury in the Everglades Ecosystem.
Everglades surface water contains several components, such as, dissolved organic carbon (DOC), which form strong complexes with inorganic mercury ions in solution. Mercury binding to dissolved organic carbon in Everglades waters is important in mercury toxicity, bioavailability, and transport. However, modeling metal-dissolved organic matter (DOM) interactions to determine the structure of specific binding sites for mercury is largely speculative. Understanding typical mercury binding sites in Everglades DOM may aid in predicting how proposed Everglades remediation strategies, involving environmental transformations and partitioning of DOM, will modify mercury DOM complexation.
Speciation of Hg (II) as a function of solution pH (4 to 8) and dissolved organic carbon concentration (0 to about 35 milligrams per liter) for an Everglades surface water is reported here.
