Laboratory Study on the Permeability of Fresh Municipal Solid Waste

Abstract

In this study, the permeability of fresh municipal solid waste (MSW) was investigated to understand the relationship between the permeation rate and hydraulic gradients, and the relationship between the permeability coefficient and the initial density. A large-scale permeability test apparatus was used and 15 fresh MSW samples were examined. Three mixture proportions were adopted and five initial densities of 0.7, 0.8, 0.9, 1.0, and 1.1 g/cm3 were selected for each mixture proportion. It was found that the seepage did not occur until the hydraulic gradient reached a critical value and the critical hydraulic gradient increased with the initial density. The permeation rate increased with the hydraulic gradient. A linear relationship was found between permeation rate and hydraulic gradient. It was also found that the permeability coefficient decreased gradually with the initial density of fresh MSW and they followed a linear relationship with the fitted coefficients greater than 0.99. In addition, the prediction model of the permeability coefficient was proposed. Furthermore, the permeability coefficient of fresh MSW was found to have some interrelationship with the sample’s mixture proportions and the organic content. Under the same condition, the permeability coefficient decreased with the organic content. The range of the permeability coefficient obtained for different mixture proportions along with other findings from this study could provide a reference guide for the analysis of the permeability of a landfill.