| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a multistage active sludge process utilizing the predatory activity of small organisms, in which while maintaining the stable quality of treated water, further enhancement of disposal efficiency and reduction of the volume of excess sludge generated can be realized. <P>SOLUTION: When organic waste water is subjected to multistage active sludge treatment with a first biological treatment tank 1 in which BOD (Biochemical Oxygen Demand) in organic waste water is subjected to high-load treatment, so as to be converted into microbial cells and a second biological treatment tank 2 in which the converted microbial cells are made to coexist with small organisms preying on the microbial cells, HRT (Hydrological Residence Time) in the first biological treatment tank required for converting 70 to <100% of BOD in the organic waste water as the standard into the microbial cells is obtained, and, with the value as standard HRT, treated water is added to the organic waste water introduced into the first biological treatment tank 1 in such a manner that the HRT in the first biological treatment tank 1 lies in the range of 0.75 to 1.5 times the standard HRT. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
