Contribution du compartiment atmosphérique au transfert des HAP dans le bassin versant aval de la Seine (bilan à l'échelle de deux bassins versants expérimentaux)

PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Sci.Terre recherche (751052114) / SudocSudocFranceF

Polycyclic aromatic hydrocarbon transport processes on the scale of a flood event in the rural watershed of Le Bebec, France

International audienceTransport processes of polycyclic aromatic hydrocarbons (PAHs) were investigated in a rural watershed in France, which led to new quantitative results on the scale of a flood event. For that purpose, principal components analysis (PCA) combined with signal decomposition of PAH Breakthrough curves were used. The results obtained by PCA enabled us to distinguish (i) the transport of low molecular weight PAHs in dissolved form and (ii) the transport of high molecular weight PAHs in particulate form. The intermediate molecular weight PAHs are distributed in these two clusters. The application of a signal decomposition method confirms the results of PCA and makes it possible to quantify the mass PAH resulting, respectively, from resuspension (13.3 mg, i.e. 77% of the total mass) and from direct transfer (2.8 mg = 16% of the total mass). For the resuspension phase, desorption of PAH (38% of the total exported mass) could be also distinguished from sediment resuspension (39%)

Investigation of Transport Processes inside Karst Aquifer by Means of STATIS

International audienceEnvironmental data sets are often multidimensional and consequently display complex structure. This article shows the limitations of principal component analysis (PCA) for the study of such three-dimensional (3D) data sets. These limitations can be resolved by the use of the statistical tool STATIS. The inlet (a swallow hole) and the outlet (a spring) of a karst system of the Western Paris basin were sampled during three rain events of various intensities. These 3D geochemical data sets (variables 3 sites 3 dates) for a karst system were analyzed by STATIS method to identify hydrological processes. STATIS proceeds in three steps (interstructure, compromise, and intrastructure), which allows us to focus the analysis of hydrologic systems at different temporal and spatial scales. Compromise plane shows that suspended matter and flood are not simultaneous and highlights a rapid flow, characterized by turbidity and phosphate, which represents a point source contamination, and a ground water flow contaminated by nitrate. Intrastructure plane allows us to compare hydrochemical variations between the swallow hole and the spring lead. By this way, hydrological processes such as direct transfer and resuspension of intrakarstic sediments before and after the flood were identified what cannot be realized by comparison of inlet and outlet breakthrough curves. Finally, results obtained from the same data set by STATIS and a coupled study using PCA and normalized hysteresis curves were compared. This comparison shows the efficiency of STATIS at the identification of transport processes and vulnerability of karst system and its potential for hydrological applications

Contamination métallique et organique des sédiments lacustres aux Etats-Unis : Evolution spatio-temporelle, processus de transport, et identification des sources

ROUEN-BU Sciences (764512102) / SudocSudocFranceF

Cycloclasticus spp. but also Pseudomonas spp. as PAH degrading bacteria in the Seine estuary (France)

International audienc

Cycloclasticus spp. but also Pseudomonas spp. as PAH degrading bacteria in the Seine estuary (France)

International audienc

Evaluation du Potentiel de Dégradation Bactérienne des HAP en Estuaire de Seine

International audienc

Evaluation du potentiel de dégradation bactérienne des HAP (hydrocarbures aromatiques polycycliques) en estuaire de Seine.

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