BTEX diffusion and sorption for a geosynthetic clay liner at two temperatures

The diffusion and sorption characteristics of a geosynthetic clay liner (GCL) are examined for a group of volatile aromatic hydrocarbons: benzene, toluene, ethylbenzene, m&p-xylene, and o-xylene (BTEX) at two different temperatures. It is shown that geotextile component of a GCL contributes to the sorption of hydrocarbons by the GCL. While the partitioning coefficients of the BTEX compounds have the order m&p-xylene approximate to ethylbenzene > o-xylene > toluene > benzene, the diffusion coefficients have the order benzene > toluene > ethylbenzene > m&p-xylene approximate to o-xylene. The reduction in diffusion and sorption coefficients with decreasing temperature have opposite effects in terms of the rate of contaminant movement through a GCL. However, it is shown that the decrease in transport due to a reduced diffusion coefficient dominates and mass transport is reduced at lower temperature.