Examining Fate and Transport of Heavy Metal in Landfill Site through Numerical Environmental Multimedia Modeling Approach

Abstract

In this study, the environmental multimedia model (EMM) is extended for assessing the heavy metal in a contaminated site. Using numerical analysis, the EMM is advanced as a numerical EMM system (NEMMS) including three computational modules for the source zone, unsaturated zone, and groundwater zone. The NEMMS incorporates a finite-difference method (FDM), finite-element method (FEM), and analytical solutions to analyze the transport of heavy metals in the environment. Additionally, Monte Carlo simulation (MCS) is conducted based on sensitivity analysis to quantify the propagation of parameter uncertainty for in-depth risk assessment. In the case study, the modeling results from both the numerical and analytical methods correspond well to the measured data. The FEM provides better results than FDM under the same conditions for the case study. The most sensitive parameters in the soil and groundwater zones are found to be the retardation factor and hydraulic conductivity. This indicates that the developed NEMMS can provide better spatial and temporal accuracy in assessing the chemical risks to the connected environmental media.