Nonequilibrium mass transfer of multi-component napl in a soil column venting

This study was conducted to investigate the mass transfer behavior for a multi-component system in the soil venting process. Soil venting experiments were conducted using gasoline-contaminated soil and models of local equilibrium assumption (LEA) and the first-order kinetic approach were used to describe the gasoline volatilization process. However, the focus was on the application of the kinetic model. In both models, thirteen major components of gasoline were selected for the model input and the rest of the gasoline was divided into 11 groups based on the retention times in the gas chromatography of gasoline. The LEA model had the tendency of underestimating the gas concentration at the initial phase and overestimating at the later phase due to the different volatilities of multi-components. In the kinetic model, the estimation of mass transfer coefficient values were carried out by adopting the relationship developed in the single-components system and choosing the appropriate modified Sherwood number. This method resulted in the good agreement with the simulation and the experimental results.