Evaluation of dual permeability of gas flow in municipal solid waste: Experiment and modeling

Non‐homogeneity of permeability largely depends on heterogeneity of the pore structure of waste in a landfill, which contributes to variation in gas flow state. Gas pressure dropping test (GPDT) was one of the most effective methods to describe the gas preferential flow, was used to investigate the gas breakthrough curves in initial pressures, moisture contents and degradation phases in lab test. Dual‐permeability model was developed to quantify the gas preferential flow in waste column. The reliability of the model was verified by a good agreement from the gas flow rate between the simulation results and experimental results. The simulation results show the biodegradation of the waste produced an obviously decrease in the permeability in fracture system due to the variation of the particle distribution. The porosity and mass transfer in fracture system has largely decreased with the continued biodegradation and moisture content increasing. It will be provided useful evidence for assessing the gas preferential flow during the well operation in landfill. © 2015 American Institute of Chemical Engineers Environ Prog, 35: 41–47, 2016