Distribution of mercury species in soil from a mercury-contaminated site
TL;DR: In this paper, the distribution of mercury species was determined in soil from a site with Hg contamination, and the concentration of total Hg ranged from 0.5 to 3000 µg Hg g−1.
Abstract: The distribution of mercury species was determined in soil from a site with Hg contamination. Mercury contamination was primarily confined to the top 40 cm of soil, and the concentration of total Hg ranged from 0.5 to 3000 µg Hg g−1. Of total Hg present, we determined that 91% was inorganic, 0.01% organic (as methyl Hg), and 6% elemental Hg. Furthermore, of total inorganic Hg present, 85% was in the insoluble mercuric sulfide form. Thus, of total Hg present in soil at this contaminated site, 91% was in the relatively insoluble HgS and Hg0 forms.
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TL;DR: In this article, a method for sequential selective extractions (SSEs) for Hg in geological solids, validated with extensive quality assurance procedures, was presented, where Mercury was separated into fractions which "make sense" biogeochemically, rather than being identified by specific compounds.
440 citations
TL;DR: In this paper, the binding forms of mercury (Hg) in contaminated soils were studied by means of a pyrolysis method and a sequential leaching procedure (SEP), and changes of the Hg-binding forms occurring during the sequential extraction procedure were characterized by determination of the thermal mercury release characteristics after each extraction step.
Abstract: Binding forms of mercury (Hg) in contaminated soils were studied by means of a pyrolysis method and a sequential leaching procedure (SEP). Changes of the Hg-binding forms occurring during the sequential extraction procedure were characterized by determination of the thermal mercury release characteristics after each extraction step. Soil samples were selected from the site of a former chloralkali plant, a wood preservation site, and two mining areas contaminated by metallic mercury (Hg0), mercury(II) chloride (HgCl2), or mercury sulfide (HgS), respectively. The results show that Hg0, matrix-bound Hg, and HgS occurring in the studied soils could be identified by their thermal release behavior. In contrast, results obtained from sequential leach ing did not allow the identification of any specific Hg compounds as in all samples most of the Hg is extracted in the nonspecific residual Hg fraction. Results of pyrolitic measurements after each extraction step demonstrated the insufficient selectivity of the use...
301 citations
TL;DR: In this article, an integrating overview of the current knowledge of the mechanisms of mercury evaporation is presented, which is necessary for tracing the fate of mercury in the biological environment and for assessing potential health effects and the impact of anthropogenic mercury emissions on the environment.
Abstract: Understanding the mechanisms of mercury evaporation from soil to the atmosphere is necessary for tracing the fate of mercury in the biological environment and for assessing potential health effects and the impact of anthropogenic mercury emissions on the environment. In this article an integrating overview of the current knowledge of the mechanisms of mercury evaporation is presented. Abiological and biological formation of Hg(0) and/or (CH3)2Hg in the uppermost soil layers are the rate limiting processes of mercury evaporation from soils in background areas; the evaporation rate in background areas is probably strongly influenced by deposited airborne mercury. The evaporation rate limiting factors in mercury enriched mineralized areas with large fractions of total mercury being volatile mercury species (relative to background soil in the non-mineralized vicinity) meteorological variations and the transport characteristics of soils for volatile mercury species. Mercury evaporation rates from background soils are usually <0.2 μg·m–2·h–1 and significantly smaller than from mercury-enriched mineralized areas.
250 citations
TL;DR: Factors affecting Hg release from soil to the atmosphere are reviewed, including how rainfall events drive gaseous elemental mercury flux from soils of low Hg content, and how ambient conditions such as atmospheric O3 concentration play a significant role.
241 citations
TL;DR: Use of this technique, in conjunction with standard microanalytical techniques such as X-ray diffraction and electron probe microanalysis, is beneficial in the prioritization and remediation of mercury-contaminated mine sites.
197 citations
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TL;DR: In this article, the authors applied substrate-electron acceptor combinations and specific metabolic inhibitors to anoxic saltmarsh sediment spiked with mercuric ions (Hg2+) in an effort to identify, by a direct approach, the microorganisms responsible for the synthesis of hazardous monomethylmercury.
Abstract: Substrate-electron acceptor combinations and specific metabolic inhibitors were applied to anoxic saltmarsh sediment spiked with mercuric ions (Hg2+) in an effort to identify, by a direct approach, the microorganisms responsible for the synthesis of hazardous monomethylmercury. 2-Bromoethane sulfonate (30 mM), a specific inhibitor of methanogens, increased monomethylmercury synthesis, whereas sodium molybdate (20 mM), a specific inhibitor of sulfate reducers, decreased Hg2+ methylation by more than 95%. Anaerobic enrichment and isolation procedures yielded a Desulfovibrio desulfuricans culture that vigorously methylated Hg2+ in culture solution and also in samples of presterilized sediment. The Hg2+ methylation activity of sulfate reducers is fully expressed only when sulfate is limiting and fermentable organic substrates are available. To date, sulfate reducers have not been suspected of Hg2+ methylation. Identification of these bacteria as the principal methylators of Hg2+ in anoxic sediments raises questions about the environmental relevance of previous pure culture-based methylation work.
1,195 citations
TL;DR: The mercury cycle in the biosphere and biological methylation of mercury and microbial resistance to mercury and organomercurials are studied.
Abstract: BIOTRANSFORMA nONS OF TOXIC MET AL CAnONS . Mercury . The mercury cycle in the biosphere .. Biological methylation of mercury . Microbial resistance to mercury and organomercurials .
413 citations
TL;DR: Biological mercury methylation was assayed by a new radiochemical technique in the water column and sediments of a mercury-contaminated lake during 24 weeks during 1979.
Abstract: Biological mercury methylation was assayed by a new radiochemical technique in the water column and sediments of a mercury-contaminated lake. In 24 weeks during 1979, there were three episodes of methylating activity in surface floc and in water, each lasting 3 to 5 weeks. Periods of methylation in the water column coincided with surface sediment methylation and appeared to be related to overall microbial activity. Mercury was actively methylated in the presence of bound sulfide.
181 citations