Data/hora: 12/06/2024 14:39:39

Provedor de dados: 	5	
País: 	France	
Título: 	Methylmercury formation in the anoxic waters of the Petit-Saut reservoir (French Guiana) and its spreading in the adjacent Sinnamary river	
Autores: 	Coquery, M; Cossa, Daniel; Azemard, S; Peretyazhko, T; Charlet, L.	
Data: 	2003-05	
Ano: 	2003	
Resumo: 	The present work was carried out on the hydroelectric reservoir Petit-Saut on the Sinnamary river in French Guiana. Measurements were performed during the wet and dry seasons along a longitudinal gradient, from upstream of the reservoir in two inflow rivers, to the Sinnamary estuary downstream of the dam. Gold extraction has led to a marked increase in suspended matter and total mercury (HgT) in one of the rivers. Dissolved monomethylmercury (MMHg) measured in surface waters were similar for both rivers: 0.03-0.05 ng l(-1) (1.0-1.7% of the dissolved HgT). These results indicate similar methylation efficiency and/or transfer of MMHg into the dissolved fraction of the water column, independently of the amounts of inorganic mercury transported. Dissolved MMHg concentrations in surface waters of the reservoir were similar to those in the rivers, but were more than 10 times higher in deep anoxic waters, up to 0.6 ng l(-1) (20 % of dissolved HgT). The MMHg concentration profiles in the water column suggest that methylation occurs mainly in anoxic waters and sediments in relation with the activity of sulfate reducing bacteria. Dissolved MMHg concentrations measured in the Sinnamary at the base of the dam were still high (0.5 - 0.6 ng l(-1); 20 to 35% of the dissolved HgT).	
Tipo: 	Text	
Idioma: 	Inglês	
Identificador: 	https://archimer.ifremer.fr/doc/2003/publication-5283.pdf

DOI:10.1051/jp4:20030308

https://archimer.ifremer.fr/doc/00000/5283/	
Editor: 	EDP Sciences	
Formato: 	application/pdf	
Fonte: 	Journal de Physique IV (1155-4339) (EDP Sciences), 2003-05 , Vol. 107 , P. 327-331	
Fonte: 	EDP Sciences

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