| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a biological treatment tank for waste water, in which a circulating flow is formed without necessitating the supply of the power other than the power for prevention of the sedimentation of a microbe-fixed carrier and that for aeration from the outside and the microbe-fixed carrier or a suspended microbe is returned excellently and to provide a biologically treating method. <P>SOLUTION: A screen 12 for separating the microbe-fixed carrier and carrier intakes 13, 13a are arranged on the outflow side of the biological treatment tank in which the microbe-fixed carrier of a suspended state is incorporated. Circulation ducts are arranged for communicating these carrier intakes with the inflow side of the biological treatment tank. Ejector pipes 18, 18a are arranged on the inflow side of the biological treatment tank so that a flow of the microbe-fixed carrier from the outflow side to the inflow side is formed in each of circulation ducts 17, 17a by utilizing a water level difference between the biological treatment tank and a waste water tank arranged on the upstream side of the biological treatment tank, namely, by transforming the positional energy into the kinetic energy. As a result, since a sucking flow is formed on the inflow side even when external energy is not supplied, the water to be treated is mixed with the microbe-fixed carrier by the ejector effect and the circulating flow is formed, and the biological treatment can be effectively performed. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
