A Comprehensive Anaerobic Degradation Model using both Mass and Energy Balance for Bio-Reactor Landfills

Landfills settle due to its weight and biodegradation of waste. Biodegradation-induced settlement is a direct result of rearrangement of waste skeleton in response to the conversion of waste mass into landfill gases. In this manuscript, a Comprehensive Anaerobic Degradation Model using both Mass and Energy Balance for Bio-Reactor Landfills was developed and compared model predations with measured data from Calgary Biocell. The model solves the mass and energy balance of waste decay, and computes the consequential rate of gas generation, and gas flux through the system. The decomposing biomass is represented as cellulose for energy balance computation. The microbial degradation of biomass generates methane, carbon dioxide and water in a exothermic reaction. The heat released due to anaerobic decay is used to calculate the increase in Biocell temperature. Then the decay constant for this Biocell temperature is used to calculate the decomposition of waste for the next time step. The above computation is continued in order to obtain the landfill settlement, temperature and the movement of landfill gas and leachate. The thermal profile predicted by the model matched reasonably well with the field values measured at the Calgary Biocell.