중금속 오염 철도토양의 전기역학적 정화: 전해질 조성의 영향

초록

Electrokinetic remediation (EK) process was conducted for railroad soil contaminated with heavy metals containing As, Cu, Pb, Zn, and Cd, where effects of catholyte’s conditions on the performance of system were investigated. In order to enhance the mobilization of heavy metals in soil, nitric acid and EDTA was added into catholyte solution. Nitric acid in catholyte played a role of pH conditioning agent to buffer for hydroxide ions generated from electrolysis of water near cathode and made soil being in low pH condition which increase the solubility of heavy metals. EDTA, the other hand, had chelating potential to form soluble complexes with heavy metals during process. As results, the EK system with 0.1 M of nitric acid in catholyte showed slightly higher electrical current density during operation, followed by increased removal of Cd and Pb.