MSW Leachate Inorganic Ion Diffusion through Compacted Soil and HDPE Geomembrane Barrier - Laboratory Experiments and Model Validation

Abstract

This paper presents the experimental and numerical results for soil contamination profiles by leachate with and without the presences of a geomembrane. Soil samples of the Rio das Ostras Landfill were assessed and examined. The batch tests were carried out with local virgin soil and with leachate. Molecular diffusion tests with and without the presences of a geomembrane were compared with the virgin soil of the sanitary landfill of Rio das Ostras (Brazil) and its leachate. The studies focused on the chloride and sodium ions. The model MPHMTP (Multi Phase Heat and Mass Transfer Program) was used in the computer simulations to estimate the diffusion coefficients through the compacted soil and geomembrane over a layer of compacted soil to forecast ion migration and predict the performance of the system in long term operation. The geomembrane used was a 2 mm of the high density polyethylene (HDPE). The results showed that the presence of the geomembrane strongly reduced the ion concentrations in the soil during the experiments carried out.