Formation of Elevated Temperatures in Municipal Solid Waste Landfills: These are not your typical Smokey hill tops or mountains!
Some municipal solid waste landfills in the United States are exhibiting subsurface temperatures nearing 150 °C and refered to as elevated temperature landfills (ETLFs). These temperatures are well above normal landfill operations, which typically range between 40 and 65 °C. ETLFs are a relatively new phenomenon and have unique characteristics and challenges including substantial changes in the composition and quantity of landfill gas and leachate, rapid waste subsidence, and in some cases, elevated liquid and gas pressures. These conditions, alone or in combination, may affect the waste containment system - engineered barriers (liners and covers), gas and leachate collection infrastructure, and the physical stability of the waste mass. Research has been performed to help quantify the contributing factors that may lead to the formation of ETLFs. In this presentation, Ducoste discusses a numerical model that was used to predict heat generation, transport and accumulation from biological and chemical reactions that occur in MSW landfills. The model includes reactions that potentially generate heat such as aerobic and anaerobic biological reactions, anaerobic metal corrosion, acid-base reactions, ash hydration and carbonation, and pyrolysis. The model offers key insights into the heat propagation and accumulation in different parts of the landfill geometry and provides some potential strategies to mitigate these elevated temperatures.
Dr. Joel Ducoste is the Associate Dean for Faculty Advancement and a Professor in the Civil, Construction, and Environmental Engineering Department at North Carolina State University (NCSU). He holds a B.S. (1988) and M.Eng. (1989) in Mechanical Engineering from Rensselaer Polytechnic Institute, and a Ph.D. in Environmental Engineering (1996) from the University of Illinois at Urbana-Champaign. Dr. Ducoste is a Board Certified Environmental Engineering member of the American Academy of Environmental Engineers and Scientists (AAEES) through eminence. Dr. Ducoste is a recognized expert in modeling water and wastewater treatment processes using Computational Fluid Dynamics (CFD). His current research interests include physico-chemical processes in water treatment, computational fluid dynamics modeling, water/wastewater process optimization, wastewater sewer collection system sustainability, plant biosystems engineering, solid waste process modeling, and disinfection of aerosol pathogens. Dr. Ducoste has served on several advisory and professional society boards including the U.S. Environmental Protection Agency (USEPA) Board of Scientific Counselors, EPA Science Advisory Board, advisory boards of engineering departments, and the Association of Environmental Engineering and Science Professor (AEESP) (served as its President). Dr. Ducoste is a member of AWWA, WEF, AEESP, and AAEES and a fellow of WEF. Prior to joining NC State University, Dr. Ducoste was a senior process engineer at CH2M Hill and before that as an advance-manufacturing engineer at GE Aircraft Engines.