ADVECTIVE-DIFFUSIVE TRANSPORT OF D_2O IN UNSATURATED MEDIA UNDER EVAPORATION CONDITION

摘要

Advective-diffusive transport of HTO in unsaturated media was investigated empirically using deuterated water (D_2O) and columns filled with glass beads. The tortuosity factor was evaluated by numerical model calculations corresponding to first experiment for diffusion under no-evaporation condition. Temporal variations in depth profiles of D_2O concentrations in the columns were observed by second experiment, which considers the transferring and spreading of D_2O by pore-water flow caused by evaporation. Measurements and model calculations indicated that diffusion was about two times more efficient than dispersion for D_2O spreading process under this evaporation condition.