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| Muresan Paslaru, Bogdan. |
| The mercury cycle was explored in the Petit-Saut reservoir / Sinnamary Estuary continuum in French Guiana. Main processes involve (i) photo-induced reduction, (ii) adsorption and desorption at the particle surfaces, (iii) methylating bacterial activity, (iv) precipitation and dissolution of iron oxyhydroxides and sulfides. Sources of mercury to the Petit-Saut reservoir consist of the partly impacted river-tributaries, the atmospheric deposition and the flooded soils or vegetation. Once into the reservoir, divalent mercury undergoes a large spectrum of transformations including speciation and phase changes. We, here, probe these processes and demonstrate that the Petit-Saut reservoir behaves as a privileged site for atmospheric recycling and in situ... |
| Tipo: Text |
Palavras-chave: Atmosphere; Estuary; Reservoir; French Guiana; Methylmercury; Mercury; Atmosphère; Estuaire; Retenue; Guyane française; Methylmercure; Mercure. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/these-1508.pdf |
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| Muresan Paslaru, Bogdan; Cossa, Daniel; Richard, S; Burban, B. |
| 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... |
| Tipo: Text |
Palavras-chave: Fluxes; Speciation; Mercury; Artificial reservoir; Atmosphere. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3329.pdf |
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| Muresan Paslaru, Bogdan; Cossa, Daniel; Jezequel, D; Prevot, F; Kerbellec, S. |
| Solid sediment, pore and epibenthic waters were collected from the Thau lagoon (France) in order to study the post depositional partition and mobility of mercury and monomethylmercury in an organic rich sediment. Total Hg (HgT) and monomethymercury (MMHg) profiles were produced in both dissolved and solid phases. The distribution of HgT in the solid appeared to be related to the historical changes in the Hg inputs into the lagoon. HgT was in equilibrium between solid and solution in the sulfidic part of the cores, with a mean log Kd of 4.9 +- 0.2. The solid appeared to be a source of HgT for pore water in the upper oxic to suboxic parts of the cores. The MMHg represented a small fraction of HgT: 3-15 % and 0.02-0.80 % in the dissolved and in the solid... |
| Tipo: Text |
Palavras-chave: Fluxes; Partition; Sediment; Lagoon; Methylmercury; Mercury. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2083.pdf |
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