Characteristics of Water-gas Two-phase CO2 Transport in Unsaturated Zone
包气带水气二相流CO2运移规律

The migration of CO2 in soil was simulated through use of soil column, especially the transformation of CO2 between water and gas phases at wetting front was studied. The soil column in the test was 1m long and the concentration of CO2 solution was 748mg/L. Through analysis, it was shown that CO2 migration in water phase was governed by advection, dispersion, reaction and mass transfer between water and gas phases, that in gas phase by advection, dispersion, mass transfer between two phases. Sampling method under dynamic condition of two phase flow in soil column was approached and mass transfer coefficient from water phase to gas phase was determined as 0.00061. This showed that there was certain mass transformation of CO2 from water phase to gas phase and yet it was not so significant. This study can provide the quantitative scientific bases for safety assessment of geological disposal of low and intermediate level radioactive waste and environmental impact assessment of solid waste disposal by landfilling.