| 摘要 |
<p>PROBLEM TO BE SOLVED: To efficiently make org. matter difficult to biologically decompose in sewage easy to decompose and to treat it irrespective of a change in the sewage quality, to increase an org. matter removal rate by biological treatment in a treating tank and to enhance the sewage treating capacity. SOLUTION: This device is provided with an ozone aeration tank 4 (ozone reaction tank) provided in a front stage of a reaction tank 2 (biological treating tank) and making org. matter difficult to biologically decompose easy to decompose and to treat it by ozone aeration, an ozonizer 5 for injecting an ozone gas into the tank 4, a UV meter 6 (absorptiometer) for measuring the quality of the sewage flowing into the tank 4, a dissolved ozone densitometer 10 for measuring the dissolved ozone concn. at the sewage flow outlet of the tank 4 and a controller 8 for controlling the injection amt. of the ozone gas into the tank 4 from the ozonizer 5 based on the measured results of the UV meter 6 and the densitometer 10. The target concn. SV(DO3 ) is set to 0<≈SV(DO3 ) and the dissolved ozone concn. at the sewage flow outlet of the tank 4 is maintained to the target concn. SV(DO3 ) by the combination control of an FF control system 12 and an FB control system 13.</p> |
