| Title |
Distribution and Transport of Abiotic & Volatile Pollutants in Wetting and Drying Unsaturated Soils |
| Authors |
구자공 ; 권혁 ( Ja Kong Koo ; Hyuk Kweon ) |
| Abstract |
A vertically one dimensional segment model (DATPUS: Distribution and Transport of Pollutant in Unsaturated Soil) was developed for the prediction of equilibrium distribution and transport of pollutants in unsaturated soil zone during the water infiltration and drainage. The change of water content in soil profile was estimated using the method of characteristic on the kinematic unsaturated flow equation, and this was utilized for the estimation of mobile phase movement of soil water and soil air between segments and through boundaries of the atmosphere and the aquifer. The developed model of pollutant equilibrium distribution among soil grain (immobile phase), soil water, and soil air that can accommodate the effects of soil water content and temperature change was combined with the continuity equation at each segment through time steps. The nonbiodegradable, volatile, and toxic solvents of dichloromethane (DCM) and 1,1,1-trichloroethane (TCE) as a representive priority organic pollutant, were studied experimentally and simulated in sandy soil and silt-clay mixture at temperatures of 4, 20, and 40℃. The quantitive result showed that much severe soil pollution occurs at lower temperatures, deeper DCM plume is developed in unsaturated soil than TCE, and thousand times higher DCM flux is penetrated into groundwater as a pollution potential. |