METHOD FOR CLEANING CONTAMINATED SOIL

PROBLEM TO BE SOLVED: To provide a method for cleaning contaminated soil which reduces cost of a cleaning liquid and of a treatment facility and improves treatment cost of cleaning liquid discarding by reducing exchanging frequency of the cleaning liquid necessary for attaining soil environmental standard by increasing elution of heavy metals or the like from the soil in cleaning of the contaminated soil. SOLUTION: The method for cleaning the soil contaminated with the heavy metals or the like is characterized by that the contaminated soil is cleaned with the cleaning liquid composed of a surfactant and an acid or an alkali, the contaminated soil is slurried and ultrasonic wave motion is applied to the contaminated soil slurry while moving the contaminated soil slurry to separate fine particles of the heavy metals or the like and further the contaminated soil slurry is cleaned with the cleaning liquid composed of the surfactant and an acid/an alkali.