Determination of waste decay rate for a large Finnish landfill by calibrating methane generation models on the basis of methane recovery and emissions.

The aim of this study was to determine the methane (CH4) generation factor (k) and CH4 generation potential (L) for bulk waste in order to calibrate a CH4 generation model (USEPA Landgem 3.02) and provide information on the remaining CH4 generation potential in a large (54 ha) municipal solid waste landfill located in a boreal climate. The CH4 generation model was calibrated by actual CH4 recovery and emission measurement data. Moreover, waste characterisation information from a previous study was considered. The appropriate k for bulk waste was 0.18 in the studied landfill, which indicated a higher rate of degradation than proposed by the Intergovernmental Panel on Climate Change as a default k value of 0.09 for wet conditions in boreal and temperate climes, whereas the calibrated L of 100 m3/t was lower than estimated on the basis of a previous waste characterisation study. The results demonstrate the importance of model calibration, as inappropriate model parameters may result in a large discrepancy (a...