CONTINUOUS DECOMPOSING METHOD OF HARMFUL SUBSTANCE BY USING GEOTHERMAL WELL AND ITS CONTINUOUS DECOMPOSING DEVICE

摘要

PROBLEM TO BE SOLVED: To efficiently decompose harmful substances and to change the substances into harmless ones without building a large-scale ground facility by sending harmful substances with a carrier fluid to a region of a supercritical water state in a geothermal well to decompose the substances and then pumping the decomposition products to the ground to recover the products in a liquid state. SOLUTION: The geothermal well to be used is prepared by further digging an abandoned geothermal well to the depth in a supercritical water region, or newly digging a well to the depth in a supercritical water region. A decomposing tank 2 and a easing 9 are inserted into the geothermal well thus prepared. The decomposing tank 2, of which the well bottom side is kept sealed is housed in the bottom of the easing 9. A supply means 6 of harmful substances is connected to a mixing tank 1. The harmful substances mixed with water as a carrier fluid or additives in the mixing tank 1 are supplied by a pump P to the decomposing tank 2. The harmful substances are decomposed by the water in a supercritical water state in the decomposing tank 2. The decomposed harmful substances are pumped up to the ground by a discharging means 7 of decomposition products.