Linked Life Data

18657305

Source:http://linkedlifedata.com/resource/pubmed/id/18657305

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-3
pubmed:dateCreated
2008-10-17
pubmed:abstractText
The detailed distribution of mercury was studied in sediments and porewaters of two freshwater lakes, which were selected because of the contrasting conditions they present at their respective sediment-water interface (SWI). One lake is characterized by a SWI that remains oxic all year long whereas the other one shows a clear seasonal variation with the evolution of strongly anoxic conditions through the summer season. The results of the study clearly identify the importance of redox conditions on the geochemical behaviour of Hg at the SWI of both lakes but a very limited influence of an oxidized layer enriched in Fe and Mn oxyhydroxides at the top of the sediment of the oxic lake. In both lakes, a competitive effect on the cycling and mobility of the element was observed between natural organic matter and amorphous or organo-sulfide compounds. The proportion of Hg associated to natural organic matter in sediments showed a general increase with sediment depth. A fraction containing elemental Hg and Hg suspected to be bound to iron sulfides and organo-sulfides constituted the other major fraction of solid Hg in the sediments of both lakes. This second pool of Hg was generally larger at the top of the sediment where the production of dissolved sulfides is usually more detectable and it decreases with depth, suggesting that the metal is partially transferred from one pool being the sulfides including amorphous FeS and organo-sulfides to the organic matter pool. Methyl Hg represented less than 1% of the total Hg in sediments of both lakes. Our results obtained at different times of the summer season from two lakes contrasted by their SWI emphasize the competitive or alternating role played by dissolved and solid natural organic matter and sulfides on the fate of Hg in freshwater systems.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0048-9697
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
405
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
226-38
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
The competitive role of organic carbon and dissolved sulfide in controlling the distribution of mercury in freshwater lake sediments.
pubmed:affiliation
Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada. nbelzile@laurentian.ca
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't