Environmental risk assessment on electrokinetic remediation of soil contaminated with heavy metals

초록

In this study, Electrokinetic (EK) process was used as a soil remediation technology to remove heavy metals. Natural chelating agents were applied in order to enhance the system performance and the environmental risk of the system was evaluated using pollution index (PI) and Danger index (DI), where both index was concerned the fraction of remaining heavy metals in soil. Electrokinetic remediation technology has been applied for soil contaminated with either organic or inorganic pollutants, or both. When low level of DC current is applied into target soil using electrodes, contaminants are forced to transport toward anode or cathode due to several mechanisms including electromigration, electrophoresis, electroosmosis, and electrolysis, etc. As an in-situ technology, EK remediation is available for sites difficult to be excavated (for example, residence, historic sites, railway etc.) and it is cost-effective, reducing cost from excavation. Three types of soil contaminated with heavy metals such as As, Cu, Pb, Zn, etc. were tested with EK system using natural chelating agents (NCAs). NCAs have potential to increase the mobility of heavy metals, which have 4 possible mechanisms: (1) competitive adsorption on soil surface