Modeling of Leachate Characteristics and Clogging of Gravel Drainage Mesocosms Permeated with Landfill Leachate

Abstract

A two-dimensional numerical model, BioClog, is used to estimate the leachate characteristics and leachate-induced clogging of laboratory mesocosms permeated with real municipal solid waste landfill leachate. The model is used to examine mesocosms with 38-mm (nominal diameter) gravel subjected to different durations of leachate permeation, mesocosms run-in series, and mesocosms with 19-mm gravel. A comparison of the calculated and measured leachate concentrations indicates that the model provided reasonable predictions of the effluent chemical oxygen demand (COD) and calcium concentrations. The calculated porosities within the saturated drainage layers are general in encouraging agreement with the measured values from all experimental mesocosms. The calculated and measured hydraulic conductivities are in reasonable agreement. The modeling results indicated that reducing the mass loading for the drainage layers and increasing the particle size of granular media can be expected to extend the time before clogging of drainage layers, and therefore, to extend the service life of landfill leachate collection systems.