| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method of purifying heavy metal contaminated soil excellent in cost performance.SOLUTION: A method of purifying heavy metal contaminated soil includes: a first process S1 of cracking heavy metal contaminated soil; a second process S2 of washing the soil cracked in the first process with an acidic solution; a third process S3 of adding and mixing the soil washed by the acidic solution in the second process with iron powder absorbing heavy metal; and a fourth process S4 of separating the iron powder from the soil to which the iron powder absorbing heavy metal in the third process is added. In the third process, an elution amount, an iron addition amount, mixing time and the repetition number of use times satisfy the following inequation: X>0.6×C0 {1-1/exp(t/4)}/(θ/n)+0.5, where X:iron powder addition amount to the soil weight (weight %), C0:elution amount of soil before washing (mg/L),θ:absorption amount at an equilibrium state to a reference value of soil elution amount of heavy metal (g/kg), t:mixing time of soil slurry and iron powder after completion of iron powder addition (minutes) and n:repetition number of use times of iron powder.</p> |
