WorldCat Identities

Venel, Zélie

Overview
Works: 2 works in 2 publications in 2 languages and 3 library holdings
Roles: Author
Publication Timeline
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Most widely held works by Zélie Venel
Ecotoxicity of polyethylene nanoplastics from the North Atlantic oceanic gyre on freshwater and marine organisms (microalgae and filter-feeding bivalves) by Magalie Baudrimont( )

1 edition published in 2019 in English and held by 2 WorldCat member libraries worldwide

Caractérisation du comportement de nanoplastiques représentatifs de l'environnement dans un gradient de salinité : évaluation de leurs impacts écotoxicologiques sur les huitres de palétuviers Isognomon alatus by Zélie Venel( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

Plastic pollution of surface water is constantly increasing and raises economic and ecological problems. According to recent studies, marine plastic debris breaks down into microparticles and nanoparticles by mechanical and photochemical processes. The nanometric fraction of environmental plastics is still unknown because there are still analytical challenges to characterize nanoparticles at trace concentrations. These particles are potentially toxic due to their composition, size and shape, but can become even more toxic, by aggregation with organic matter, or by surface adsorption of trace metals or organic contaminants. Up to date, there is limited studies about behavior of nanoplastics in transitional waters such as estuaries and mangroves. The aim of this thesis is to (i) characterize physico-chemical behavior of nanoplastic models in a salinity gradient, with an innovative methodology using microfluidics; (ii) study the ecotoxicological impact of these nanoparticles on bivalves, with an exposure representative of in situ conditions.Polystyrene latex, as well as mechanically aged nanoplastics from either pristine polystyrene pellets or from macro-plastics sampled on Guadeloupe beaches (polyethylene, polypropylene), were dispersed across a salinity gradient under dynamic conditions inside a microchip. Results were compared with conventional protocols i.e. dispersing standard nanospheres in a homogeneous saline medium under static conditions. Sizes, concentrations, morphologies, compositions and stability of these nanoparticles were measured as a function of the physicochemical conditions of the medium. Then, the ecotoxicological impact of model nanoplastics dispersed via a salinity gradient was studied on flat tree oysters: Isognomon alatus. Exposures were carried out by direct route at environmental concentrations. Different markers such as metallothionein production and early gene expression have been used to assess the toxicity of nanoplastics. This thesis also allowed the development of one of the most sensitive instruments for the analysis of nanoparticles at ultra-trace concentration: the Laser Induced Breakdown Detection (LIBD). This work highlights the impact of salinity gradients on the behavior of nanoplastics and its importance in the toxicity assessment on bivalves during the transition from freshwater to seawater
 
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Audience Level
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Audience level: 0.97 (from 0.96 for Caractéri ... to 0.97 for Ecotoxicit ...)

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