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Antony, France

The Water European Framework Directive requires the implementation of programs to monitor the chemical quality of water bodies (freshwater, transition water and seawater), based on grab measurements of concentrations of various contaminants (metals, organic compounds). The results are limited by several analytical difficulties, and the poor representativity because of the temporal variability of contamination. The passive sampling techniques, which basically consist of concentrating substances on a submerged device for a given period, and analyzing accumulated substances, should improve the monitoring, by simplifying analytical issues (lower detection limits, analysis in a simpler matrix), and allowing time integration of the contamination. Here, we present two passive sampling techniques of contaminants that are validated in aquatic environments: the Diffusive Gradient in Thin film (DGT) for metals and the Semipermeable Membrane Device (SPMD) for hydrophobic organic compounds. Both systems allow estimating a timeweighted average concentration of "labile" contaminants, the most bioavailable ones. After a presentation of each tool, examples of applications in river, seawater and wastewater are proposed.

Limam R.D.,UR HBAN | Limam R.D.,French Atomic Energy Commission | Limam R.D.,University of Evry Val dEssonne | Limam R.D.,University of Carthage | And 8 more authors.
Canadian Journal of Microbiology | Year: 2010

We collected samples of anaerobic landfill leachate from municipal solid waste landfill (Vert-le-Grand, France) and constructed 16S rRNA clone libraries using primers targeting Planctomycetes and relatives (Pla46F and 1390R). Analyses of 16S rRNA gene sequences resulted in the abundant representation of WWE2-related Lentisphaerae, members of the phylum Lentisphaerae, in the clone library (98% of the retrieved sequences). Although the sequences that are phylogenetically affiliated with the cultured isolate Victivallis vadensis were identified (WWE2 subgroup II), the majority of the sequences were affiliated with an uncultured Lentisphaerae lineage (WWE2 subgroup I). We designed oligonucleotides probes targeting the specific 16S rRNA gene regions of those 2 subgroups. Fluorescence in situ hybridization confirmed the abundance of the uncultivated WWE2 subgroup I in our leachate samples.

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