Electrokinetic Remediation of Heavy Metals-Contaminated Soil Pretreated with Humic Substances

초록

Recently it was reported that soil near a metal refinery facility in South Korea has been contaminated seriously with heavy metals including arsenic, copper, lead, and zinc. For a long time, dust containing heavy metals from the chimney of the refinery facility has polluted surrounding soil and it was suspected to be the main reason for the deceased from cancer who had lived around the area. Electrokinetic remediation technology has been applied to transport and remove heavy metals from soil effectively. Especially, several chemical additives, such as EDTA, could achieve enhanced effects on the mobilization of heavy metals, which were bonded strongly with soil particles. It is important to decide the appropriate additives in electrokinetic remediation systems because of their potential to be secondary pollutants. Natural organic matters (NOMs), such as humic acid and fulvic acid, have been known to be biodegradable chelating agents. They have several functional groups including hydroxyl, phenolic, and carboxylic groups, which are likely to form chelating bonds with certain heavy metals, which may increase the solubility of heavy metals. NOMs also compete with heavy metals for bonding sites on soil surface, which enhance the mobilization of metals. In this study, natural organic matters were applied in electrokinetic remediation of soil from a metal refinery facility, which was contaminated with As, Cu, and Pb. The target soil was pretreated with NOMs to enhance the mobilization of heavy metals in EK system.