Laboratory investigations of potential sanitary landfill settlement

A laboratory investigation was conducted to develop a method to evaluate sanitary landfill settlement. The investigation involved steps to identify settlement due to compression and biodegradation. Testing was conducted in a respirometer to measure oxygen demand from representative materials and biodegradation accelerated by adding enzymes. Materials were consolidated in a large oedometer. An initial compression ratio was defined. Results showed differing amounts of settlement for mechanical and biological components. Findings included: acceleration of degradation can be accomplished by adding enzymes; an initial compression ratio is a useful tool for laboratory analysis; the coefficient of compressibility was dependent on the amount of biodegradation; laboratory compression ratios agreed well with many field studies; and, the ratio of the secondary compression index to the primary compression index was not constant.