A comprehensive study of temperature data during the filling and post-closure phases at a landfill in Québec, Canada: Application of a thermal-mechanical-biological model.

A 12-year field study on municipal solid waste (MSW) stabilization in Northern climates was conducted at Ste. Sophie landfill in Québec, Canada. Temperature and settlement data were collected from 12 instrument bundles placed at varying depths in two vertical columns within the waste during the filling and post-closure phases. The data demonstrated a 12-18 month delay in temperature rise during the filling stages due to frozen or partially frozen MSW and highlighted ambient temperature effects at shallow depths. A thermal-mechanical-biological (TMB) model was developed and calibrated to simulate the impact of temperatures on MSW stabilization, particularly emphasizing landfills without leachate recirculation in Northern climates. The biological model related anaerobic heat generation from MSW with temperature and expended energy from biodegradation. The resultant heat was integrated into the thermal model, allowing for the simulation of heat transfer through conduction. The thermal parameters were expressed as a function of density, which was updated in the mechanical model that combined a Generalized Kelvin-Voigt model with a biodegradation-induced strain term. This term was represented as the ratio of expended energy over time to total potential expended energy of the waste. The TMB model effectively predicted MSW behaviour, considering temperature rise delays in cold and sharp rises in warm conditions. This is essential for optimizing landfill operations by promoting waste stabilization before applying the final cover.