| 摘要 |
PURPOSE:To redude a BOD value of waste water in a small-sized installation, by an active sludge process accompanied with the aeration of waste water under a compressed atmosphere in a line mixer having a mechanically strong agitation ability. CONSTITUTION:After coarse solids are separated, waste water is fed to a line mixer 5 by a pressure pump 4. In the mixer 5, the waste water is compressed by controlling an opening rate of a sequeezing valve 9 in the midway of a discharge pipe 10. At the same time, active sludge is introduced through a pump 7 by compressed air from a compressor 6, to rapidly and uniformly agitate the waste water. The waste water is then carried to a floatation vessel 11 where a flocculant is added in the waste water. In the vessel 11, sludge grains adhere onto fine air bubbles and float, while precipitable ingredients are precipitated by the flocculant. Thus, the waste water is forcibly contacted with the active sludge and air, and oxidized biologically. Consequently, waste water can be disposed at a high efficiency in a small-sized installation. |
