| 摘要 |
PROBLEM TO BE SOLVED: To effectively wash earth and sand contaminated with oil such as fuel oil. SOLUTION: In this device, contaminated earth and sand to be treated is introduced in a separation tank 2, and from the bottom part thereof, detergent is caused to flow into the contaminated earth and sand to agitate and mix them, and the separated oil components and the detergent used for washing are recovered from the upper part of the separation tank to a recovery tank 3. By spraying the detergent while the contaminated earth and sand are transferred being agitated by a rotary screen, mixing agitation is performed. The contaminated earth and sand and the detergent are mixed and agitated in a mixing tank 1, and the oil contents and the detergent used for washing are separated by a centrifuge. As the detergent, water solution of water glass such ass sodium silicate is used. As the detergent, water solution of organic solvent is used, and also it is regenerated by a distillation device. After washing with the detergent, finish washing with fresh water is performed, and the fresh water used for the finish washing is recovered and the oil components are adsorbed and recovered by an adsorption tank 5. |
