Inorganic arsenic speciation in the waters of the Penzé estuary (NW France): Seasonal variations and fluxes to the coastal area

Jennifer Vandenhecke (1) , Matthieu Waeles (1) , Jean-Yves Cabon (2) , Cédric Garnier (3) , Ricardo D. Riso (1)

1 LEMAR - Laboratoire des Sciences de l'Environnement Marin (LEMAR)
2 CEMCA - Chimie, Electrochimie Moléculaires et Chimie Analytique
3 PROTEE - Processus de Transfert et d'Echanges dans l'Environnement - EA 3819

Over this one-year study, the variations of inorganic As species were examined monthly along the salinity gradient of the Penzé estuary (NW France) in relation with different biogeochemical parameters. In most cases, dissolved As exhibited a non-conservative behaviour which resulted from the competition between two major processes. In the upstream section of the estuary, a strong input of both total inorganic As and As(III) occurred. Then, the removal of the same species, under precipitation of iron oxides/oxyhydroxides, was observed in the low-salinity range (S < 10). Using our experimental data, the fluxes of the various As species were estimated for the first time in estuarine waters. Inputs from the river were mainly constituted of particulate As (w70%). Conversely, dissolved species were predominant in the net fluxes (w65%) and As(III) accounted for w15% of the dissolved net flux.

Domains: Analytical chemistry; Continental interfaces, environment; Ocean, Atmosphere; Geochemistry; Environmental and Society; Global Changes

Jennifer Vandenhecke, Matthieu Waeles, Jean-Yves Cabon, Cédric Garnier, Ricardo D. Riso. Inorganic arsenic speciation in the waters of the Penzé estuary (NW France): Seasonal variations and fluxes to the coastal area. Estuarine, Coastal and Shelf Science, 2010, 90, pp.221-230. ⟨10.1016/j.ecss.2010.09.003⟩. ⟨hal-01096840⟩