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Contribution of modeling to the knowledge of trace elements behaviour and speciation in estuaries ArchiMer
Gonzalez, Jean-louis; Dange, Catherine; Thouvenin, Benedicte.
Geochemical models are excellent tools for the understanding of trace elements dynamics, in particular in complex environments like estuaries. Their aim is to reproduce numerically the biogeochemical processes observed in the field or laboratory. The development and the use of this kind of tool requires: - in-situ data on the distribution in space and time of the elements studied and relationship with the environmental variables. - experimental data (mainly based on the use of radioactive analogues of the studied elements) for evaluation of model parameters and the validation of model assumptions. The model must be capable not only of reproducing the distribution of metals between the dissolved and particulate phases, but also of evaluating the...
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Ano: 2002 URL: https://archimer.ifremer.fr/doc/00479/59099/61737.pdf
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Etude du comportement des éléments traces en milieu estuarien : approche expérimentale et modélisation : Application à l'étude de la spéciation de Cd, Co et Cs dans les estuaires majeurs français (Seine, Loire, Gironde, Rhône) ArchiMer
Dange, Catherine.
Most of trace elements have a non conservative behavior in estuarine environments. It is the case of cadmium, cobalt and caesium for which the fate in estuarine and coastal zones is largely controlled by their distribution between water and suspended particles, which generally have high residence times or can be definitely deposited in these areas. Metallic contaminants and radionuclides can be present under various species : dissolved (mineral and organic complexes), colloidal and particulate forms (adsorbed, precipitated) or integrated by various mechanisms in the organisms. Such distributions are the result of processes (physical, chemical, biological) which are controlled by many factors (ionic strengh, pH, Eh, major cations concentration, nature and...
Tipo: Text Palavras-chave: Modeling; French estuaries; Caesium; Cobalt; Cadmium; Radionuclides; Trace metals; Speciation; Modélisation; Estuaires français; Cesium; Cobalt; Cadmium; Radionucléides; Métal trace; Speciation.
Ano: 2002 URL: http://archimer.ifremer.fr/doc/2002/these-183.pdf
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Rôle des particules sur le comportement et la spéciation de métaux traces: exemple du cadmium ArchiMer
Gonzalez, Jean-louis; Thouvenin, Benedicte; Dange, Catherine.
The role of particles in the fate and speciation of trace metals in macrotidal estuaries was studied using a surface complexation model (MOCO). Cadmium was selected as the target metal contaminant due to its reactivity in estuaries: cadmium behavior is mainly controlled by heterogeneous processes (sorption/desorption) related to salinity and suspended matter gradients.Various scenarios of suspended matter distribution according to salinity were simulated. The impact of surface properties (specific surface area, density of surface sites, acidity instrinsic properties and complexation constant) was evaluated using data collected on particles from the Gironde, Loire and Seine estuaries.
Tipo: Text Palavras-chave: Particles; Speciation; Sorption/desorption; Cadmium; Modeling; Surface properties.
Ano: 2007 URL: https://archimer.ifremer.fr/doc/00480/59152/61781.pdf
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Role of particle sorption properties in the behavior and speciation of trace metals in macrotidal estuaries: The cadmium example ArchiMer
Gonzalez, Jean-louis; Thouvenin, Benedicte; Dange, Catherine; Chiffoleau, Jean-francois; Boutier, Bernard.
The role of particles in the fate and speciation of trace metals in macrotidal estuaries was studied using a surface complexation model (MOCO). Cadmium was selected as the target metal contaminant due to its reactivity in estuaries: cadmium behavior is mainly controlled by heterogeneous processes (sorption/desorption) related to salinity and suspended matter gradients. Various scenarios of suspended matter distribution according to salinity were simulated. The impact of surface properties (specific surface area, density of surface sites, acido-basic properties, and complexation constant) was evaluated using data collected on particles from the Gironde, Loire, and Seine estuaries. Our results show that particle surface properties, evaluated on the basis...
Tipo: Text Palavras-chave: Turbidity maximum; Speciation; Sorption; Particles; Modeling; Macrotidal estuaries; Cadmium.
Ano: 2006 URL: http://archimer.ifremer.fr/doc/2006/publication-2005.pdf
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Spéciation des contaminants métalliques en milieu estuarien : Intérêt de la modélisation et application au cadmium ArchiMer
Gonzalez, Jean-louis; Dange, Catherine; Thouvenin, Benedicte.
In estuarine environment, cadmium has a nonconservative behavior. It can be present under various species: dissolved (mineral and organic complexes), colloidal and particulate forms (adsorbed, precipitated), or integrated by various mechanisms in the organisms. This distribution is the result of processes (physical, chemical and biological) which are controlled by many factors (salinity, pH, Eh, nature and concentration of suspended matter, primary production). Geochemical modeling is a very useful approach to understand the dynamics of this type of contaminant, especially in the complex systems which are the estuaries. A speciation model was used to simulate the measurements taken (dissolved and particulate Cd) during various cruises carried out in the...
Tipo: Text Palavras-chave: Cadmium; Estuary; Speciation; Modeling; Surface complexation; Cadmium; Estuaire; Spéciation; Modélisation; Complexation de surface.
Ano: 2001 URL: https://archimer.ifremer.fr/doc/00480/59120/61749.pdf
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