Abstract: To investigate the feasibility of electrokinetic soil processing on the removal of Cd from Cd-contaminated red soils, a laboratory experiment was conducted. A constant direct current density of 0.5mA/cm² was applied. The result shows that the Cd-removal efficiency is remarkably pH-dependent, which is caused by the change of Cd retention capacity of the red soils under different pH conditions. The initial Cd concentration is 1.490g/kg and over 79% of it is removed from the red soils after treatment for 96h. The energy expenditure per unit volume at the end of experiment is about 77.6kW•h/m³ and the capital consumed by the whole experiment is 42.6RMB Yuan/m3, which suggests that the electrokinetic soil processing is a promising technology for remedying Cd-contaminated red soils due to its high removal efficiency and low energy consumption.

Key words: cadmium; electrokinetic soil processing; red soil; electroosmosis