| 摘要 |
<p>PROBLEM TO BE SOLVED: To efficiently treat sludge generated in conjunction with aerobic biological treatment of waste water containing organic material and to reduce economical burden required for the sludge treatment. SOLUTION: The waste water A containing organic material is subjected to aerobic biological treatment by a biological treatment system 10, is separated from the sludge and discharged outside the system as treated water C. The sludge D1 which is pulled out of the biological treatment system 10 is subjected to ozone treatment at an ozone treatment part 20 and, thereafter, returned to the biological treatment system 10 though an aeration tank 30 outside the system. The sludge D2 after the ozone treatment is subjected to the aerobic biological treatment in the aeration tank 30 outside the system and is returned to the biological treatment system 10, thereby, the conversion of the sludge outside the system to BOD-causing components is progressed and the discharge quantity required for making the discharged quantity of the sludge zero is reduced.</p> |
