Field Test for Treatment of Contaminated Soil around Railroad Track using Soil Flushing Method

초록

Korean government reinforced the regulation related to soil pollution, recently. Railroad sites are one of main pollution area and several remediation projects have been already performed at high cost. Soil around railroad track has been often polluted by oil drop during the refueling of railcars. Most of contaminants are diesel, which is difficult to treat from the field. The purpose of this study was to investigate the field application of soil flushing method to clean up diesel-contaminated railroad soil. Target site was located in a railcar depot and the amount of contaminated soil was about 30 ton. The used flushing agent was 3.0% (w/w) of Triton X-100. Initially, the pollution level of the target site was assessed with the depth of the soil. High oil concentration was showed mostly between 1 m and 3 m depth, which its value was over 10,000 mg of total petroleum hydrocarbon (TPH) per kilograms. For the oil removal of target soil, the flushing agent was injected uniformly on the surface with a constant gap, and then was extracted periodically from the well installed in the middle of the site. As a result, the residual oil concentration in soil was reduced into less than 2,000 mg TPH/kg soil without the depth of the target site. In conclusion, soil flushing method can be applied efficiently to remediate the railroad soil contaminated by diesel in the field.