Simultaneous removal of oil and heavy metals from the contaminated railroad soil in korea

초록

Generally, the contamination of railroad soil has been caused by the oil leakage from the operation of rolling stocks, fueling, and lubrication for the maintenance of track or turnout. Also, heavy metals are main pollutants in the railroad site, which may be resulted in the frictions between wheel and track, the contact between wires and pantographs, and the use of wasted lubricants. Recently, Korean railroad operating company has been performed several large-scale remediation projects to remove oil from the field due to the domestic regulation related to the contaminated soil. However, it is still difficult to clean up efficiently the railroad site polluted by both oil and heavy metals. The purpose of this study was to remove oil and heavy metals simultaneously from the contaminated railroad soil. The target soils were sampled around track and turnout at the workshops of rolling stocks. Initial concentrations of TPH(Total Petroleum Hydrocarbons) and heavy metals(Zn) were much higher than the precaution level defined under the Korean regulation. Various surfactants, acids and oxidized solvents were tested as soil flushing agents. Tergitol and HCl showed the highest removal efficiency of TPH and heavy metals. In future, these results can be applied for the practical remediation of the railroad site with multi-contaminants.