2012
Maritime transport of liquid and floating chemicals: experimental study of the submarine accidental release following a shipwreck / Mélanie Fuhrer
Thesis jointly supervised by Ecole des Mines d'Alès. PhD jointly supervised by: Gilles DUSSERRE, Research Director at Ecole des Mines d’Alès
Committee: Jacques BOURGOIS, Yann LEREDDE, Frédéric MUTTIN, Claude CASELLAS, Lounès TADRIST, Laurent APRIN, Frédéric HEYMES, Stéphane Le FLOCH
Abstract: Maritime transport quickly increases during the last decade. It is the cheapest way to transport large quantities of goods over long distances. The growth of this trade necessarily leads to an increase in the traffic density and therefore the risk of accident and sinking increases as well. The large amount of chemicals involved in an accident may threaten the environment and human health in case of shipwreck with underwater chemical release. Unfortunately the physicochemical mechanisms occurring during the transfer of a chemical to the sea surface are still poorly understood. Those mechanisms depend on various parameters such as the physicochemical properties of the chemicals and the specific properties of the accident surroundings.
This research was conducted in collaboration with the Ecole des Mines d'Alès and Cedre in a global approach to understand the behaviour of liquid, floating and soluble chemicals released after a shipwreck. This experimental study has been carried out according to 3 main points:
- The phenomenology of a release at the breach. The objectives are to quantify the flow rate and the release pattern,
- The hydrodynamic behaviour of the released chemicals and their fate in the water column,
- The mass transfer of the chemical during its solubilization in the water column.
For each point, the results are compared to those predicted by correlations in the literature in order to propose a global model of consequences that is adapted to the marine pollution management.
Bibliographical reference: http://doc.cedre.fr/index.php?lvl=notice_display&id=9139
Methodological developments for the extraction and analysis of organic pollutants of interest for the marine environment: application to polycyclic...
Thesis jointly supervised by the University of Bordeaux I. PhD jointly supervised by: Hélène BUDZINSKI, CNRS - UMR 5805 in Bordeaux
Committee: Valérie CAMEL, Pierre DOUMENQ, Patrick MAZELLIER, Stéphane LE FLOCH
Abstract: The presence of hydrocarbons in the environment either as a result of oil spills at sea or due to chronic discharge is a major concern because of their ecotoxicity and their potential to bioaccumulate and thus enter the food chain. Therefore, these molecules are closely monitored and reliable analytical methods are required to identify and quantify them, for concentrations ranging from mg/L to ng/L. However, in most cases, laboratory analyses of hydrocarbons, especially aromatic hydrocarbons, are limited to the quantification of 16 polycyclic aromatic hydrocarbons (PAHs) identified by the U.S. Environmental Protection Agency (U.S. EPA) as hazardous to the environment due to their carcinogenic nature. However, polycyclic aromatic sulphur heterocycles (PASHs) and their substituted homologs are, in chemical terms, structurally similar to PAHs, and therefore can pose similar environmental risks, i.e. they can be carcinogenic or mutagenic. In this context, the research work carried out aims to develop methodologies for the extraction and analysis of a wider range of PAHs, PASHs and their alkyl derivatives directly in oil or dissolved in the aqueous phase. Extraction protocols by stir bar sorptive extraction (SBSE) and solid phase microextraction (SPME), and methods of analysis by gas chromatography coupled with mass spectrometry (GC-MS) and with tandem mass spectrometry (GC-MS-MS) have been developed. The results argue in favor of these methodologies both in terms of linearity of the response and in terms of sensitivity. These methodologies that have been successfully applied for the determination of analytes of interest in the water accommodated fraction and water soluble fraction prepared in the laboratory (WAF and WSF). For GC-MS-MS, while it is particularly suitable because it provides an additional level of selectivity, it is a difficult technique to implement, in particular in the case of molecules for which no calibration solutions are available. To overcome this difficulty, a reference oil containing all the target molecules was characterized. For alkylated compounds that are not commercially available, approximations were made by simple MS, based on comparative analysis of response coefficients in MRM (Multiple Reaction Monitoring) and SIM (Single Ion Monitoring) modes. The finalized method was used to characterize the Erika fuel oil, with low variability in the results. This product can be used as a reference for the quantitative analysis of all the families of molecules identified in this study.
Bibliographical reference: http://doc.cedre.fr/index.php?lvl=notice_display&id=9279