Modelling The Landfill Process Using Gassim2

摘要

The prediction of landfill gas generation is an important exercise for both operators and regulators of landfill sites.The GasSim2 model,developed for this purpose by Golder Associates (UK) Ltd on behalf of the Environment Agency,is used to predict gas generation and subsequent emissions to air and land in order to assess whether emissions exceed acceptable limits.A number of other models for the prediction of landfill processes exist,and they have evolved significantly over the last decade.In order to compare individual models' strengths and weaknesses and therefore enable further development,a formal framework was designed by researchers at Southampton University.A challenge was set to modellers to predict the performance of a laboratory experiment on biodegradable waste.The data provided,including waste composition,cellulose and hemicellulose content,leachate recirculation and experimental layout,were manipulated to fit into GasSim2.A number of difficulties were experienced in modelling,including scaling the laboratory experiment to the required scale of the model,categorisation of the waste stream and the length of the model timestep.Model results indicate a potential for gas production of 17·7-47·6 m~3/t dry waste per year initially,decreasing over time.