Consulta: subjectFacets:"Spéciation"
Registros recuperados: 6
Data/hora: 02/06/2024 05:32:44

Cycle du mercure en estuaire, baie de Seine et pays de Caux
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Laurier, Fabien.
The Seine estuary and its adjacent region Pays de Caux are two significant sources of mercury for coastal marine environments. It is carried through fluvial means for the Seine bay and through karstic fresh water emergences for Pays de Caux's coastal area.  Mercury cycle in the Seine estuary and bay is affected by additional anthropical activities. The estuary's maximal turbidity area acts like a trap and a chemical reactor for fluvial mercury. Within this area, we can confirm: (i) the non conservative behaviour of dissolved mercury; (ii) mercury enrichment of particles when comparing the Seine's and marine environment and we suggest mercury particle redistribution from the organic fraction to the oxyhydroxydes fraction. A large fraction of mercury is...
Tipo: Text
Palavras-chave: Bay of Seine; Pays de Caux; Estuary; Coastal zone; Speciation; Bioavailability; Mercury; Pays de Caux; Seine; Estuaire; Emergence; Zone côtière; Spéciation; Biodisponibilité; Mercure.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/these-1842.pdf

Spéciation des contaminants métalliques en milieu estuarien : Intérêt de la modélisation et application au cadmium
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Spéciation du cuivre en milieu hydrothermal profond et dans les zones de suintements froids
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Aumond, Virginie.
This work presents the copper speciation in the deep ocean and the exchanges existing between different size fractions : particulate, dissolved and colloidal. It focus on the mixing zone between deep sources and seawater. The enhancement of our knowledge and the optimization of instrumentation make possible the development of sampling and analysis strategies accorded with the nature and the accessibility of these extreme environments. A part of this work consisted in the development of effective analysis methods for the quantification of copper and copper’s ligands. Our results showed that physical speciation seems to be essentially controlled by the variations of pH and oxydoreductive caracteristics during the dilution of the hydrothermal fluid by...
Tipo: Text
Palavras-chave: Analyse chimique; Spéciation; Hydrothermal; Cuivre; Sulfures; Dorsale Médio-Atlantique; Lucky Strike; Guaymas; Cuivre -- Spéciation; Bouches hydrothermales.
Ano: 2013
URL: https://archimer.ifremer.fr/doc/00692/80379/83500.pdf

Etude de l’influence de la concentration et de la spéciation de trace de cadmium sur la croissance et la physiologie d’une espèce phytoplanctonique
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Millour, Mathieu.
The aim of this study is to establish a continuous culture of a diatom (Phaeodactylum tricornutum) in a photobioreactor. As soon as the culture is stable and regulated, increasing cadmium amounts are added to the culture to induce a metal stress in order to study its influence on the production of Volatile Reduced Sulphur Compounds (H2S, OCS, MeSH, DMS and DMDS), and on the production of ligands. In this report, the methods used to assess the continuous culture and to analyse RVSC and other ligands production are described. J This study allowed us to assess cadmium impact on the VRSC and on the production of ligands.
Tipo: Text
Palavras-chave: Photobioréacteur; Phaeodactylum tricornutum; Cadmium; Composés Soufrés Réduits et Volatils; Culture en continu; Spéciation; Complexants.; Photobioreactor; Phaeodactylum tricornutum; Cadmium; Volatile Reduced Sulphur j Compound; Continuous culture; Speciation; Ligands.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/00306/41765/40978.pdf

Modélisation des contaminants chimiques dans une colonne d'eau. Modèle MOMO (MORGAN+MOCO).
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Thouvenin, Benedicte; Gonzalez, Jean-louis.
Within the framework of the "Contaminants cycle and modeling" project of the BE department ("Biogeochemistry and Ecotoxicology") in Ifremer, two chemical contaminant modeling software were developed between 1998 and 2011 (Gonzalez JL, 2017): the MORGAN model (Model behavior of ORGANic contaminants in an aquatic environment) and the MOCO model (Surface Complexation MOdel for metallic COntaminants). These two models had been brought together in a single "zero-dimensional" software (known as MOMO), which made it possible to simulate the various processes affecting the behavior of chemical contaminants in a homogeneous mass of water (biodegradation, adsorption/desorption, photolysis, hydrolysis, volatilization, surface complexation, cation exchange,...
Tipo: Text
Palavras-chave: Modelisation; Biogeochimie; Contaminants métalliques et organiques; Spéciation; Modeling; Biochemical; Trace metals - organic contaminants; Speciation.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00686/79771/82993.pdf

Les Stenasellidae (Crustacea Isopoda Asellota Anophtalmes) des eaux souterraines du sultanat d’Oman
Provedor de dados: Naturalis Digital Academic Repository
Autores: Magniez, Guy J.; Stock, Jan H.
Descriptions of four new species of Stenasellus (Aselloidea: Stenasellidae) from the underflow of temporary streams (wadis) in northern part of Oman Sultanate. S. vermeuleni n.sp. (11.2 mm or more) and S. messanai n.sp. (7.7 mm or more) are probably karstic water species, accidentally or locally present in the alluvium. The smaller S. henryi n.sp. (3.5 mm), the most widely spread, seems to be typically an inhabitant of coarse sand and gravel alluvial deposits, and bears hypertrophied gnathopods. S. grafi n.sp. (2 mm), the smallest known Stenasellid, is highly adapted to mesopsammal life; its dwarfism reduces drastically the number of oocytes, but little their size. The species of the arabian Peninsula are strongly related to these of eastern Africa...
Tipo: Article / Letter to the editor
Palavras-chave: Aquifères karstiques; Cohabitation; Espèces fouisseuses (burrowers); Mésopsammiques (mesopsammal); Genus Stenasellus; Stygobies; Milieu interstitiel; Nanisme (dwarfism); Sous-écoulement (underflow); Spéciation.
Ano: 2000
URL: http://www.repository.naturalis.nl/record/505189