Analytical solutions for 1-D transport of organic solutes in multi-layered porous media

Abstract

In this study, the analytical solutions for one-dimensional (1-D) transport of organic solutes in multi-layered porous media are developed by the methods of matrix transfer and variable separation, where the multi-factors such as advection, diffusion, mechanical dispersion, adsorption, degradation, boundary condition type as well as the change of concentration are systematically incorporated for the first time. Compared with the existing analytical solutions solved by the techniques of integral transformation or Laplace transformation, the approaches adopted in this paper are simpler with quicker convergence speed. Also, the proposed analytical solutions are more practical with clear expressions and the consideration of the multi-factors, which can be applied to various engineering cases such as bottom liner system at landfills, covering system of contaminated sediments and vertical barrier system in contaminated sites. Furthermore, the correctness of the derived analytical solutions is effectively validated by comparison with the experimental results, the existing analytical solution and a numerical method. Following this, the effects of different factors on the transport process of a single organic solute in a five-layered media are investigated, and some novel and vital laws are obtained. Overall, this research contributes to appropriately evaluating the transport behaviors in multi-layered porous media.