Practical Application of Novel Physical Ballast Washing System to Soil Remediation In Polluted Rail Yard

초록

Rail yards are apt to be polluted by petroleum or various kinds of heavy metal during the operation of rail cars. For this reason, many soil remediation projects are carried out, and the polluted ballast gravels should be remediated as well. Water washing method using detergent or chemical treatment using oxidant is conventionally used for the treatment of polluted ballast gravels. In this study, novel ballast gravel treatment method, dry washing method, was introduced for the field application. In dry washing method, chips made of alumina or melamine resin were blasted on the surface of polluted ballast gravels by using compressed air. The pollutants residing on the surface of the ballast gravels could be successfully removed while there was no significant damage on ballast gravels themselves. The treatment time was very short compared with that of water washing method, and the amount of secondary pollutants was also very small because no water is used. A pilot-scale treatment system was prepared. The maximum capacity of this system was 0.1 m3/h. This system was installed in a soil remediation sites, and the feasibility study on the treatment of polluted ballast gravels was carried out. This system could remediate the polluted ballast gravels efficiently and quickly. Treatment results of this system were presented in this study.