METHOD FOR CLEANING HEAVY METAL CONTAMINATED SOIL

摘要

PROBLEM TO BE SOLVED: To reduce disposal cost by not only maintaining purification effect but also reducing the volume of a residue containing heavy metal generated by scrubbing.SOLUTION: A method for cleaning a heavy metal contaminated soil includes: a classification step 1 where slurry-shaped earth and sand G1 from which a coarse particle component G2 is separated by allowing water to be added to a contaminated soil G0 contaminated by the heavy metal and by carrying out wet sieve classification thereof is further classified into a sand component S1 and fine grain component S2; a surface treatment step 2 where an acid 7 is added to the classified sand component S1 to allow the surface of a soil particle of the sand component S1 to be fragile; and a scrubbing step 3 where scrubbing of the surface layer portion of a sand component S3 of which surface is treated is carried out by agitation thereof so that the surface layer portion is peeled off and separated from the sand component S3.