In the previous study, the authors have investigated the mechanism and the optimum condition of lead removal from contaminated soil by application of sequential treatment of chlorination and warm water extraction. Lead was successfully removed from soil at lower temperature than conventional heat treatment on soil. However, relatively large amount of mixed chloride was required.
In this paper, new soil remediation technique was investigated to overcome the disadvantage of the sequential treatment. In the new method, stable lead complex in soil was chlorinated to be PbCl2 by HCl gas emitted by reaction between SiO2 and MgCl2-CaCl2-KCl mixed chloride. Because of high vapor pressure of PbCl2, lead was eliminated from soil by chlorination volatilization. Lead removal was promoted by enhancing volatilization of PbCl2 by introducing carrier gas and by optimizing mixed chloride composition. Residual lead content was reduced more effectively with small amount of mixed chloride than the sequential treatment.
