This paper analyses sanitary landfills as biochemical reactors and par
ticularly the significance of water balance and multi-phase flow in a
landfill system. Field studies reveal a strong coupling between water
content and landfill gas production. This study focuses on evaluation
of field observations on water content, temperature, gas and leachate
production in specially designed and operated landfills. Theoretical s
imulation of multiphase flow conditions - water and gas transport - ha
s been carried out for different components of the landfill system. To
p cover as barrier to gas exchange, 1-D heat transport and heat source
distribution and water percolation reproducing mechanical dispersion
due to presence of waste elements in the sanitary landfill are modelle
d to improve insight into the overall performance of sanitary landfill
s.