Pilot-scale electrokinetic treatment of dispersive soil and feasibility study of sodium ion transport across the soil by electric field relocation

摘要

Electrokinetic treatment is one of the few in situ soil remediation options. Dispersive soils are among the most important and prevalent types of geotechnical problematic soils on the surface of the earth. Upon contact with water, clay minerals of these soils disintegrate and become suspended. This disintegration puts many conventional and hydraulic structures at risk of damage. In a pilot-scale electrokinetic treatment test with a 2D rhombic setup on a 85 x 45 x 28 cm cell of natural fully dispersive soil, it was observed that the areas subjected to one dominant electric field experienced the best remediation results with average sodium ion removal efficiency of 84%. However, areas under two intersecting fields underwent inferior remediation. These results were confirmed in part by the result of ESP and pinhole tests. Feasibility tests on the transport of sodium ion across the soil by stepwise relocation of electric field showed that relocation of DC field leads to effective transport of considerable amounts of sodium to the next location.