Modelling the effects of environmental conditions on the biodegradation of organic material in municipal landfills

The rate of methane production in municipal landfills is influenced by a large number of processes. The relevance of these various interacting processes can be evaluated on the basis of a mechanistic model. The aim of this research is to evaluate the relevance of environmental conditions (pH, temperature, moist content) on the methane production rate in municipal landfills. This evaluation is based on model simulations with the mathematical model described below, and model parameters taken fi-om literature resources or laboratory experiments. The hydrolysis of solid organic matter is regarded as the rate-limiting process. However, reported specific hydrolysis rate constants vary over several orders of magnitude. The question of which hydrolysis rate constant is representative for a landfill section, could be answered more accurately if the rate of hydrolysis is regarded as a function of the type of environmental condition (pH, temperature, moist content), the type of organic material, and the bio availability of the organic material.