Investigating Air Intrusion and Aerobic Reactions in Municipal Solid Waste Landfills

Abstract:

The design, management, and operation of municipal solid waste landfills involve significant complexities due to the occurrence of thermo-hydro-biochemical processes. The implications to sustainable disposal includes operation of gas wells to limit air intrusion, which facilitates aerobic decomposition. In this study, the TOUGH2 Landfill Bioreactor Model incorporating a variably saturated domain and kinetics-controlled biological reactions, both aerobic and anaerobic, was employed to simulate a 2-D landfill with municipal solid waste. The results of simulations involving air from the atmosphere intruding into an anaerobically operated landfill on the internal temperature, chemical composition of gases, moisture content, and pressure within the landfill are presented and discussed. The results show that the rapid shift from anaerobic to aerobic condition in adjacent of air intrusion location causes an increase of 30 °C within the first few days of intrusion, which even after the fixation of the intrusion, the heat will remain in place for months to years.