ABSTRACT
The presence of salts is detrimental to plant growth in soils and also impedes consolidation in disposed mine tailings. The current study conducted small-scale column drying tests on “clean” soil prepared to homogenous initial pore-water concentrations using a model wax column technique. This study characterized the coupling of 1D solute mass transport in unsaturated soils to surface evaporation. Rapid salt accumulation in the top 1 cm of treated soil was observed. This coincided with the profile gravimetric water content for treated soil being higher compared to control soil. However, throughout the experiment, the relative evaporation for treated soil was only a fraction of values for control soil. This is attributed to the surface salt crust acting as a capillary barrier to the upward flux of water through soil to the atmosphere. This study demonstrates the significance of salt crust formation in predicting evaporation from saline soils and mine tailings disposal facilities.
