Composition selection manner, the composition extracting equipment, being the manner which selects soil cleaning manner

摘要

PPROBLEM TO BE SOLVED: To provide a method for cheaply cleaning a soil containing PCB using a mixed solvent of water, a hydrophilic solvent and a hydrophobic solvent. PSOLUTION: A solvent extraction method has an extraction step for extracting the hydrophilic solvent from the mixed solvent containing water, the hydrophilic solvent with the lower boiling point than water, the hydrophobic solvent with the higher boiling point than water and PCB by distillation, a separation step for separating water and the hydrophobic solvent, which are contained in a concentrated liquid remaining in the extraction step, according to the difference of the specific weight, and a step for purifying the hydrophobic solvent by distilling the PCB containing hydrophobic solvent separated in the separation step. PCOPYRIGHT: (C)2008,JPO&INPIT