Consulta: creatorFacets:"Grimaldi, Michel"
Registros recuperados: 2
Data/hora: 13/06/2024 07:14:30

Methylmercury in tailings ponds of Amazonian gold mines (French Guiana): Field observations and an experimental flocculation method for in situ remediation
Provedor de dados: 5
Autores: Guedron, Stephane; Cossa, Daniel; Grimaldi, Michel; Charlet, Laurent.
Sites of monomethylmercury (MMHg) production in Amazonian regions have been identified in hydraulic reservoirs, lake sediments and wetlands, but tailings ponds have not yet received sufficient attention for this purpose. This work evidenced high MMHg production within the water column and the interstitial water of two tailings ponds of French Guiana Au mines located; (i) in a small scale exploitation (Combat) where Hg was used for Au amalgamation, and (ii) in an industrial on-going Au mine (Yaoni) processing without Hg. The (MMHg)(D) maximum (2.5 ng L-1) occurred in the oxic water column above the sediment-water interface (SWI) of the most recent tailings pond (Combat), where the substrate was fresh, the redox transition was sharp and the pool of total Hg...
Tipo: Text
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00030/14117/12133.pdf

Amazonian former gold mined soils as a source of methylmercury: Evidence from a small scale watershed in French Guiana
Provedor de dados: 5
Autores: Guedron, Stephane; Grimaldi, Michel; Grimaldi, Catherine; Cossa, Daniel; Tisserand, Delphine; Charlet, Laurent.
Total mercury (HgT) and monomethylmercury (MMHg) were investigated in a tropical head watershed (1 km(2)) of French Guiana. The watershed includes a pristine area on the hill slopes and a former gold mined flat in the bottomland. Concentrations of dissolved and particulate HgT and MMHg were measured in rain, throughfall, soil water and at three points along the stream. Samples were taken in-between and during 14 storm events at the beginning and middle of the 2005 and 2006 rainy seasons. Dissolved and particulate HgT concentrations in the stream slightly increased downstream, while dissolved and particulate MMHg concentrations were low at the pristine sub-watershed outlet (median = 0.006 ng L-1 and 1.84 ng g(-1), respectively) and sharply increased at the...
Tipo: Text
Palavras-chave: Mercury; Methylmercury; Tropical watershed; Gold placers; Stream water; Oxisols; Hydromorphic soils.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00035/14628/12134.pdf