A two-dimensional analytical model for organic contaminant transport in cutoff wall and aquifer system

Cutoff walls are widely used as in-situ geoenvironmental barriers to isolate the contaminants caused by landfill leakage, chemical storage tank accidents, and mining activities. A two-dimensional analytical solution is developed to investigate the behavior of organic chemical transport in cutoff wall and aquifer. The method of Laplace transforms and finite Fourier cosine transform is adopted to derive the solution for a finite domain. The proposed analytical solutions are verified by the numerical approach. The effects of contaminant source distribution, aquifer scale, direction of flow rate, degradation, adsorption, and thickness of cutoff wall were investigated. The investigation of non-uniformly distribution of contamination sources indicates that the 1-D models lead to a more conservative result compared to the 2-D models. Biodegradation will be a dominant process and significantly enhance the performances of the barrier system when the half-life of contaminant is less than 4 years. Furthermore, the effect of dimension on breakthrough time can be augmented with the increase of distribution coefficient.