3D-printed AD-EKG for reinforcement and remediation of heavy metal-contaminated soils

Metal electrode corrosion and soil shrinkage in electrokinetic remediation and reinforcement may lead to poor electrode-soil contact and increased interfacial resistance during the mid-to-late stages of electro-osmosis. In this study, two plain-woven electrokinetic geotextiles using carbon fiber and polyester were fabricated to avoid the corrosion of electrodes, and a deformable support (DS) was developed using 3D printing technology to adapt to soil shrinkage. Comparative experiments were conducted to evaluate the performance of different electrode materials and DS in electrokinetic remediation and reinforcement. The results demonstrated that electrokinetic geotextiles with higher carbon fiber content could slow the increase of anodic interfacial resistance and exhibit better electro-osmotic drainage performance. The incorporation of DS could effectively improve the contact between electrode and soil, thereby further enhancing electro-osmotic drainage efficiency. Based on a soil resistivity model and monitoring results of the voltage at both ends of the soil, electric current and cumulative drainage volume, the copper ion content in the soil initially declined and then leveled off in the mid-to-late stages, as validated by both measured and predicted results. Compared to traditional metal electrodes, the adaptive deformable electrokinetic geosynthetics (AD-EKG) achieved more effective performance of electrokinetic remediation and reinforcement.