Determination of Waste Properties from Settlement Behaviour of a Full Scale Waste Cell Operated As a Landfill Bioreactor

The proper engineering of landfill bioreactors require operation in a manner that maximizes waste decomposition and gas generation while making use of the settlement that occurs. Settlement in landfills consists of interacting multiphase media with each phase exhibiting variations both in time and space. There are mathematical models available to evaluate the processes of biodegradation, gas generation and transport and distribution of moisture within a landfill. At the same time, many existing waste settlement models focus on compression of waste solids but overlook the contribution from other phases. An effective model for landfill settlement should be able to consider settlement, gas generation and fluid transport simultaneously. However, the phase interactions involved in landfill settlement are not well understood. Apart from the theoretical uncertainties in the phase interactions, a major obstacle to developing a multiphase settlement model is the amount of data required to calibrate and validate the model. This manuscript presents data from study of a full scale waste cell currently operated as a landfill bioreactor. The waste cell is equipped with gas collection and leachate recirculation systems, and is instrumented to collect time resolved data. This waste cell is being used as a research facility to study the impact of leachate recirculation on gas production and settlement.