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Methylmercury Formation in Mercury‐Treated River Sediments During in situ Equilibration
Author(s) -
Jacobs L. W.,
Keeney D. R.
Publication year - 1974
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1974.00472425000300020006x
Subject(s) - methylmercury , mercury (programming language) , environmental chemistry , sediment , chemistry , aqua regia , atomic absorption spectroscopy , mercure , sulfide , extraction (chemistry) , geology , metal , bioaccumulation , chromatography , analytical chemistry (journal) , paleontology , physics , organic chemistry , quantum mechanics , computer science , programming language
An in situ experiment was established at two environmentally different river sites (one each on the Wisconsin and Fox rivers) to evaluate the extent of methylmercury (MeHg) production in and Hg loss from sediments treated with mercuric chloride (HgCl 2 ) or phenylmercuric acetate (PhHgAc). Bulk sediment was collected from each river site, treated with approximately 1, 10, or 100 ppm Hg (oven‐dry basis) as HgCl 2 or PhHgAc, and returned to the river site with untreated controls for 2, 4, or 12 weeks of equilibration with the aquatic environment. After each sample retrieval, the sediments were analyzed for total Hg using an aqua regia digest and flameless atomic absorption spectrophotometry and for MeHg by gas chromatography using a modified extraction procedure which is described. Results suggest that Hg losses from stationary sediments are minimal and that sediment transport is probably the major source of Hg movement in a river system. In both sediments, more MeHg was produced from PhHgAc than from a similar concentration of HgCl 2 , and MeHg concentration increased as the Hg treatment with either compound was increased. The MeHg concentrations found in the Wisconsin River sediments were substantially higher than in the Fox River sediments with a similar Hg treatment. The large differences in MeHg production between these two sediments may be partially attributed to their chemical dissimilarities. The Wisconsin River sediment is acidic and contains more organic materials compared to the Fox River sediment which is more alkaline and contains larger amounts of sulfide sulfur.