| Registro completo |
| Provedor de dados: |
ArchiMer
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| País: |
France
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| Título: |
Mercury speciation and exchanges at the air-water interface of a tropical artificial reservoir, French Guiana
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| Autores: |
Muresan Paslaru, Bogdan
Cossa, Daniel
Richard, S
Burban, B
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| Data: |
2007-10
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| Ano: |
2007
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| Palavras-chave: |
Fluxes
Speciation
Mercury
Artificial reservoir
Atmosphere
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| Resumo: |
The distribution and speciation of mercury (Hg) in air, rain, and surface waters from the artificial tropical lake of Petit-Saut in French Guiana were investigated during the 2003/04 period. In the air, total gaseous mercury (TGM) at the dam station averaged 12 +/- 2 pmol m(-3) of which > 98% was gaseous elemental mercury (GEM). GEM distribution depicted a day-night cycling with high concentrations (up to 15 pmol m(-3)) at dawn and low concentrations (down to 5 pmol m(-3)) at nightfall. Reactive gaseous mercury (RGM) represented < 1% of the GEM with a mean concentration of 4 3 fmol m(-3). Diel RGM variations were negatively related to GEM. In the rain, the sum of all Hg species in the unfiltered (HgTUNF) averaged 16 +/- 112 pmol L-1. Temporal distribution of HgTUNF exhibited a pattern of high concentrations during the late dry seasons (up to 57.5 pmol L-1) and low concentrations (down to 2.7 pmol L-1) in the course of the wet seasons. Unfiltered reactive (HgRUNF), dissolved gaseous (DGM) and monomethyl (MMHgUNF.) Hg constituted 20, 5 and 5% of HgTUNF, respectively. All measured Hg species were positively related and displayed negative relationships with the pH of the rain. In the reservoir surface waters, dissolved total mercury (HgTD) averaged 3.4 +/- 1.2 pmol L-1 of which 10% consisted of DGM. DGM showed a trend of high concentrations during the dry seasons (480 +/- 270 finol L-1 and lower (230 +/- 130 finol L-1) in the course of the wet seasons. Diel variations included diurnal photo-induced DGM production (of about 60 firiol L-1 h(-1)) coupled to minute to hour oxidation/ reduction cycles (of > 100 firiol L-1 amplitude). Finally, calculated atmospheric Hg inputs to the Petit-Saut reservoir represented 14 mot yr(-1) whereas DGM evasion reached 23 mol yr(-1). Apportionment among forms of Hg deposition indicated that up to 75% of the total Hg invasive flux follows the rainfall pathway. (C) 2007 Elsevier B.V. All rights reserved.
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| Tipo: |
Text
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| Idioma: |
Inglês
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| Identificador: |
http://archimer.ifremer.fr/doc/2007/publication-3329.pdf
DOI:10.1016/j.scitotenv.2007.06.013
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| Editor: |
Elsevier
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| Relação: |
http://archimer.ifremer.fr/doc/00000/3329/
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| Formato: |
application/pdf
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| Fonte: |
Science of The Total Environment (0048-9697) (Elsevier), 2007-10 , Vol. 385 , N. 1-3 , P. 132-145
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| Direitos: |
2007 Elsevier B.V. All rights reserved
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