Christophe Darnault, Assistant Professor au Department of Environmental Engineering & Earth Sciences, Clemson University donnera une conférence le vendredi 5 mai 2017 à 10h30 dans l'amphithéâtre de l'Osuc et à 15h dans l'aquarium du BRGM ayant pour titre Flow and Transport in Porous Media: Applications in Environment and Energy

Abstract : Flow and transport in porous media with applications in environment and energy are complex phenomena that encompass a wide range of disciplines, including physics, chemistry, biology, earth sciences, hydrology, soil and water engineering, and reservoir engineering. Understanding flow and contaminants transport processes in porous media is critical for the mitigation of their impacts, the development of effective remediation procedures, the exploitation and management of subsurface resources --aquifer systems and petroleum reservoirs, and the protection of the environment and public health. The release of emerging contaminants, such as engineered nanomaterials, into the environment; the prevalence of microbial pathogens due to wildlife and agricultural activities in rural and agricultural watersheds; and the discharge of radionuclide wastes during storage, handling, and disposal of nuclear materials in groundwater systems are inevitable. To study the fate and transport of these contaminants in the vadose zone, we have investigated their mobility under different hydrodynamic and biogeochemical conditions found in the natural environment. We have demonstrated the critical role that preferential flow (macropore flow and fingered flow); transient in water content and velocity; transient in solution chemistry, gas-water interfaces; solid interfaces; system heterogeneities; plants and microbes; and their interactions and feedback have in the flow, transport, and retention of contaminants in the vadose zone. Mobilization of crude oil from geologic formations is essential for the exploitation of petroleum reservoirs and the oil recovery process. We have explored the ability of nanoparticles to improve the efficiency of the chemical-enhanced oil recovery process (EOR) that uses surfactant flooding by examining interfacial and rheological properties of multiphase systems and sandstone-crude oil-nanofluid systems. To elucidate the individual contribution of the mechanisms and natural parameters affecting the flow phenomena, transport, and retention of these contaminants, as well as to quantify and visualize them, we have developed monitoring methods and tools using physical, chemical, microbiological, molecular, and non-intrusive technologies. The results of our research will contribute to the development and validation of flow, fate, and transport models of contaminants from pore scale to watershed scale for management and protection of groundwater resources, petroleum reservoirs, public health, ecosystem sustainability, risk assessment, and life-cycle analysis.