报告人：Associate Professor: Christophe Darnault
Understanding flow and transport processes in the natural environment and agroecosystems is critical for the sustainable exploitation and management of natural resources —soil, water, forests, and fossil fuels, the development of effective remediation procedures, and the protection of the human and ecosystem health. Our research on the soil and water conservation in agricultural and forestry systems investigates the impacts of water reuse and prescribed fires practices on the surface and subsurface processes —hydrology and soil erosion, and water quality within this landscape. We studied the spatial distribution and morphometry of closed depressions change over time in a wastewater spray irrigated karst landscape with bedrock fractures, and modeled the groundwater flow and nitrate transport in the karst aquifer resulting from the reuse and disposal of large volumes of treated wastewater for assessing the sustainability of the use of recycled and treated water for irrigation in agriculture and forestry land uses. Our research on post-fire effects on hydrological and geochemical processes in soil from forest of the Southeastern United States established the soil physico-chemical and hydraulic properties of unburned and burned soils and how these properties relate to infiltration and water repellency phenomena as well as sorption behaviors of polar and nonpolar compounds. The release of emerging contaminants, such as engineered nanomaterials, into the environment; the prevalence of microbial pathogens (Cryptosporidium parvum and Toxoplasma gondii) in the soil and water systems; and the discharge of radionuclides (uranium) during storage, handling, and disposal of nuclear materials in groundwater are inevitable. To study the fate and transport of these contaminants in the subsurface, we have investigated their mobility under different hydrodynamic and biogeochemical conditions found in the environment. We have demonstrated the critical role that preferential flow; transient water content, velocity, and chemistry, gas-water and solid interfaces; system heterogeneities; plants and microbes; and their interactions and feedback have in the flow and contaminants behavior. Mobilization of crude oil is essential for the exploitation of petroleum reservoirs. We have explored the ability of nanoparticles (silica nanoparticles) to improve the efficiency of the chemical-enhanced oil recovery process 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 parameters affecting the flow phenomena, transport processes, and fate 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. Our research results 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 soil and water resources, petroleum reservoirs, public health, ecosystem sustainability, risk assessment, and life-cycle analysis.
Christophe Darnault 简介：
Associate Professor at the Department of Environmental Engineering and Earth Sciences at Clemson University. He is the Chair of the South Carolina Section of the American Society of Agricultural and Biological Engineers. He serves as Associate Editor for Frontiers in Environmental Science – Soil Processes, Frontiers in Earth Science, section Soil Processes, and served as Associate Editor for the Journal of Hydrology (Elsevier). He is one of Clemson’s representatives for the Consortium of Universities for the Advancement of Hydrologic Science, Inc. He has research and teaching experience at Rensselaer Polytechnic Institute and University of Illinois at Chicago. He was also a visiting scholar at Yale University. He received his Ph.D. in Environmental and Water Resources Engineering from Cornell University, and his combined M.S. & B.S. degree (Diplôme d’Ingénieur) in Agricultural, Environmental, and Biological Engineering from the Institut Supérieur d'Agriculture, Lille, France (1995). His experience has also encompassed working as water resources group leader at Environmental Engineering and Technology, Inc. and as project engineer at Malcolm Pirnie, Inc. (now the Water Division of ARCADIS). Dr. Darnault’s teaching and research interests are in the fields of environmental health and engineering/bioengineering, agricultural and biological engineering, hydrological sciences, hydraulic engineering, and soil and water resources engineering and management. Particular contributions include vadose zone processes, multiphase flow in porous media, the fate and transport of pathogenic microorganisms, nanomaterials, non-aqueous phase liquids, radionuclides, and nutrients in soils and geological media under natural conditions; and the development and application of novel methods—including electromagnetic radiations (light transmission, fluorescence, gamma-ray, x-ray), microbiological, and molecular—for the monitoring and visualization of biological/environmental systems and processes.