| 摘要 |
PROBLEM TO BE SOLVED: To allow oil content, VOC, and the like to be removed by vacuum evaporation, by installing comparatively simple pipe bodies in a ground to lower a ground water level and simultaneously making the pressure of the inside of a ground negative.SOLUTION: A plurality of pipe bodies 2 are installed in a ground at predetermined intervals, compressed-air is supplied to the pipe bodies 2, and the compressed-air is continuously supplied from the lower parts of the pipe bodies 2 into the ground, thereby bringing water pressure in the ground into a pressurized state. Thereafter, a negative pressure is applied to the pipe bodies 2 to attract water and air of the ground from the lower parts of the pipe bodies 2, thereby lowering a ground water level and simultaneously turning the inside of the ground to a negative pressure. Concretely, a step of continuously supplying the compressed-air into the ground and a step of extracting water and air of the ground are repeated. A compressor 15 for supplying compressed-air to the pipe bodies 2, a lift pump 4 for applying the negative pressure to the pipe bodies 2 to attract water, and a vacuum pump 6 for applying the negative pressure to the pipe bodies 2 to attract air are used therefor. A porous part 2a allowing water and air to flow is provided in the lower part of the pipe body 2. |
