| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the amount of activated sludge effectively by a method in which organic sludge, after, being digested anaerobically, is added with ozone and subjected further to aeration treatment in the presence of aerobic microorganisms. SOLUTION: Organic sludge 1 is first digested anaerobically in an anaerobic digestion process 2 to be reduced of its weight. After that, solid-liquid separation is conducted by a UF membrane to obtain separated liquid 4 containing no substantial SS. The separated liquid 4 is discharged outside the system. Besides, most of membrane-separated sludge 5 is refluxed to the digestion process 2 as reflux sludge 8. The residue of the membrane-separated sludge (transfer sludge 6) is supplied to an ozone oxidation tank 7 to be subjected to oxidation by ozone. Solubilized sludge 10 is led to an aerobic digestion tank 9 to be separated into carbon dioxide gas and water by various aerobic microorganisms. Sludge discharged from the digestion tank 9 is separated into concentrated sludge and supernatant, the supernatant is discharged to a system, and the concentrated sludge is refluxed to the oxidation tank 7 or digestion tank 9 to be treated.</p> |
