| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a contaminated soil washing method and an arsenic-contaminated soil washing method that can increase the ratio of reusable purified soil while effectively reducing the amount of treatment soil exceeding the elution amount reference value and the like and required to dispose of itself as contaminated soil.SOLUTION: An arsenic-contaminated soil washing method comprises: an alkali extraction process of adding an alkali-containing treatment agent to at least slurried arsenic-contaminated soil or a part of the arsenic-contaminated soil to extract arsenic, adsorbed on soil particles of the contaminated soil, into liquid of the slurry in a dissolved state with alkali; and a decanter classification process of performing decanter classification of the slurried contaminated soil, which is an object to be washed, after the alkali extraction process or a part of the contaminated soil at a predetermined classification point to solid-liquid separate it into slurried fine particles containing a supernatant liquid and being not larger than the classification point, and solids exceeding the classification point.</p> |
