Abstract: To investigate the rate of removing heavy metal Cd from paddy field soil with electric dehydration based on Electrokinetic geotextile (EKG), a leaching-electric dehydration laboratory simulation experiment was conducted. The variations of pH value of soil and the removal rate of Cd were inspected under different voltage gradients (1,2,3,4,5 V/cm) and electrode spacings (20, 30, 40, 50 cm) after leaching with FeCl₃. Results show that during the electric repair, the pH value of soil fluctuated between 2.2-2.5; the electric removal rate of Cd in soil increased with the climbing of voltage gradient, while decreased with the expansion of electrode spacing, and the removal rate was up to 47%; moreover, the energy consumption per unit of electric removal rate is positively correlated with the voltage gradient and the electrode spacing. The research finding demonstrates that electrokinetic dehydration with EKG as electrode material could control the pH value of soil effectively and promote the efficient removal of movable Cd in pore water of soil.

Key words: paddy field soil, heavy metal Cd, electrokinetic geosynthetics (EKG), leaching, electric dehydration, removal rate, pH value