a new empirical model to estimate landfill gas pollution

background: landfills are the most important producers of methane as human source. so, prediction of landfill gas generation is by far the most important concern of scientists, decision makers, and landfill owners as well as health authorities. almost all the currently used models are based on monod equation first order decay rate which is experimental while the main purpose of this research is to develop a numerical model.   methods: a real scale pilot landfill with 4500 tons of municipal solid waste has been designed, constructed, and operated for two years. required measurements have been done to provide proper data on greenhouse gases emitted by the landfill and monitor its status such as internal temperature, leachate content, and its settlement during two years. afterwards, weighted residual method has been used to develop the numerical model. then, the newly mathematical method has been verified with data from another landfill.   results: measurements showed that the minimum and maximum percentages of methane among landfill gas were 22.3 and 46.1%, respectively. these values for velocity of landfill gas are 0.3 and 0.48 meters per second, in that order.   conclusion: since there is just 0.6 percent error in calculation as compared to real measurements from a landfill in california and most of the models used have ten percent error, this simple empirical numerical model is suggested to be utilized by scientists, decision makers, and landfill owners.