Probability design of thickness of composite liners based on organic pollutant diffusion

Diffusion is the main mode for organic pollutant transporting through composite liners. At present, research about the uncertainty of transport parameters and its effect on performance of liners are lack. The design method of liner thickness is mostly deterministic. Based on the existing research on the transport parameters, the effect of variability of transport parameters on concentration and flux at the base of liner using Monte Carlo method have been studied in the paper. The variability of partition coefficient and diffusion coefficient of organic pollutant through geomembrane can be neglected, while the variability of diffusion coefficient and retardation factor has very significant effect. The result of deterministic method is pronounced dangerous. So it is necessary to study the probability characteristics of diffusion and retardation of organic pollution through soils. Taking toluene as an example, the thickness of the liner is designed, which is 1.71-1.81 times of that based on certainty method. It is more reasonable to design the thickness of the liner through the transport calculation based on probabilistic perspective.