Enhanced dissolution of cinnabar (mercuric sulfide) by dissolved organic matter isolated from the Florida Everglades

Journal Article · Sun Nov 01 04:00:00 EST 1998 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es9804058· OSTI ID:323747

Ravichandran, M; Ryan, J N ^[1]; Aiken, G R; Reddy, M M ^[2]

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1. Univ. of Colorado, Boulder, CO (United States). Dept. of Civil, Environmental, and Architectural Engineering
2. Geological Survey, Boulder, CO (United States)

Organic matter isolated from the Florida Everglades caused a dramatic increase in mercury release from cinnabar (HgS), a solid with limited solubility. Hydrophobic (a mixture of both humic and fulvic) acids dissolved more mercury than hydrophilic acids and other nonacid fractions of dissolved organic matter (DOM). Cinnabar dissolution by isolated organic matter and natural water samples was inhibited by cations such as Ca{sup 2+}. Dissolution was independent of oxygen content in experimental solutions. Dissolution experiments conducted in Dl water had no detectable dissolved mercury. The presence of various inorganic (chloride, sulfate, or sulfide) and organic ligands (salicylic acid, acetic acid, EDTA, or cysteine) did not enhance the dissolution of mercury from the mineral. Aromatic carbon content in the isolates correlated positively with enhanced cinnabar dissolution. {zeta}-potential measurements indicated sorption of negatively charged organic matter to the negatively charged cinnabar at pH 6.0. Possible mechanisms of dissolution include surface complexation of mercury and oxidation of surface sulfur species by the organic matter.

• OSTI ID: 323747
• Journal Information: Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 21 Vol. 32; ISSN ESTHAG; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
EVERGLADES NATIONAL PARK
MERCURY
MERCURY SULFIDES
ORGANIC COMPOUNDS
WATER CHEMISTRY
WATER POLLUTION