Hydrogen Cyanide Accumulation and Transformations in Non-polluted Salt Marsh Sediments
Author(s)
Kamyshny, A.
Farquhar, J.
Mansaray, Z. F.
Oduro, Harry D.
Date Issued
October 2012
Journal
Aquatic Geochemistry
Publisher
Springer Netherlands
Citation
Kamyshny, A., H. Oduro, Z. F. Mansaray, and J. Farquhar. “Hydrogen Cyanide Accumulation and Transformations in Non-Polluted Salt Marsh Sediments.” Aquat Geochem 19, no. 2 (October 13, 2012): 97–113.
Version
Author's final manuscript
Abstract
While cyanide is known to be produced by many organisms, including plants, bacteria, algae, fungi and some animals, it is generally thought that high levels of cyanide in aquatic systems require anthropogenic sources. Here, we report accumulation of relatively high levels of cyanide in non-polluted salt marsh sediments (up to 230 μmol kg[superscript −1]). Concentrations of free cyanide up to 1.92 μmol L[superscript −1], which are toxic to aquatic life, were detected in the pore-waters. Concentration of total (free and complexed) cyanide in the pore-waters was up to 6.94 μmol L[superscript −1]. Free cyanide, which is released to the marsh sediments, is attributed to processes associated with decomposition of cord grass, Spartina alterniflora, roots and possibly from other sources. This cyanide is rapidly complexed with iron and adsorbed on sedimentary organic matter. The ultimate cyanide sink is, however, associated with formation of thiocyanate by reaction with products of sulfide oxidation by Fe(III) minerals, especially polysulfides. The formation of thiocyanate by this pathway detoxifies two poisonous compounds, polysulfides and hydrogen cyanide, preventing release of free hydrogen cyanide from salt marsh sediments into overlying water or air.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
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Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1007/s10498-012-9180-5
