| The proper engineering of landfill bioreactors requires their operation in a manner that maximizes waste decomposition and gas generation while making use of the settlement that occurs. There are a number of advantages to the operation of landfill bioreactors since the landfill gas produced can be collected and used in energy recovery processes such as power generation. The methane present in landfill gas is a potent greenhouse gas and the use landfill gas in energy recovery processes reduces the environmental impact of this gas. In addition, as the waste decomposes, it compacts or consolidates, hence allowing additional refuse to be deposited into the cell. Settlement in landfills consists of interacting multiphase media with each phase exhibiting variations both in time and space. 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 research presents the study of a full scale bioreactor landfill equipped with gas collection and leachate recirculation systems and sophisticated monitoring equipment capable of providing many of the parameters required for a multiphase settlement model. |
