EARTH AND SAND PURIFYING APPARATUS

摘要

PROBLEM TO BE SOLVED: To treat polluted soil on the spot by making it possible to remove an oil component from oil polluted soil without using a surfactant to constitute an earth and sand purifying apparatus compactly. SOLUTION: This apparatus has a washing tank 3 having air jet orifices arranged on the bottom part thereof and capable of receiving oil polluted soil S along with washing water W and a screw conveyor 15 for discharging soil is disposed to the bottom part of the washing tank 3. A sedimentation tank 4 is disposed adjacent to the washing tank 3 through a first partition weir 7. The sedimentation tank 4 and an oil recovery tank 5 are made adjacent to each other through a second partition weir 8 lower than the first partition weir 7. The washing water W accumulated on the bottom of the oil recovery tank 5 is returned to the washing tank 3 through a circulating passage 26 to be reutilized.