Study on transport and transformation of contaminant through layered soil with large deformation

Abstract

Based on large-deformation consolidation theory and the advection-dispersion equation of contaminant in saturated porous media, a one-dimensional theoretical model for coupled large-deformation and solute transport through layered finite soil is presented. This model comprehensively takes the effect of soil weight, sorption, and biodegradation into account. Model validation and applications are achieved through case studies of double-layered finite soil, with the transport and transformation process of contaminant being reproduced numerically. It is found that the breakthrough time of contaminant obtained from the linear adsorption solution is greater than the case of the non-linear adsorption solution, which can provide a reference for the design of landfill liner. Simulation results also indicate that relevant factors affect the transport of contaminant in layered soil interdependently; comprehensive study is required to assess the capacity of natural clay barrier for contaminant transportation.