| 摘要 |
<p>PURPOSE:To increase the amount of O2 dissolved in raw water to be treated for enhancing the power of treating BOD, in a method for bringing a liquid into countercurrent contact with gas in a fluidized bed process, by hermetically sealing a tank and holding the inner pressure of said tank at a high level. CONSTITUTION:Raw water to be treated is supplied through a water supply pipe 11 to the interior of a hermetically sealed tank 10 and circulated therein as a downward stream through a fluidized bed 13 formed from a carrier 14 having specific gravity smaller than that of water. At the same time, air is injected through a sparger pipe 15 into the raw water to be treated and brought into countercurrent contact with the raw water to be treated. Hereon, the inner pressure of the tank 10 is raised above ordinary pressure in a range below about 5kg/cm<2> by a booster. Hence, the dissolution of O2 into the raw water to be treated is acceleratd, and the dissolution ratio of O2 is held at a high level corresponding to the inner pressure and temp. of the tank 10.</p> |
