Search International and National Patent Collections

1. (WO2004026774) METHOD OF REDUCING VOLUME OF SLUDGE AND APPARATUS THEREFOR

Pub. No.:    WO/2004/026774    International Application No.:    PCT/JP2003/010732
Publication Date: Apr 1, 2004 International Filing Date: Aug 26, 2003
IPC: C02F 1/66
C02F 3/12
C02F 11/18
Applicants: KOGA, Takeshi

MATSUMOTO, Shigeki

Inventors: MATSUMOTO, Shigeki

Title: METHOD OF REDUCING VOLUME OF SLUDGE AND APPARATUS THEREFOR
Abstract:
The pH value of excess sludge withdrawn from biological oxidation tank (2) is adjusted to 8-14, and charged into solubilization unit (3). The sludge withdrawn from the solubilization unit (3) is heated at 110 to 350°C under a pressure higher than the saturated water vapor pressure so as to effect solubilization into the state of being microbially easily decomposable. The thus solubilized sludge is returned to the biological oxidation tank (2). The pH value within the biological oxidation tank (2) is adjusted to 5-9. The use of the above method of treating excess sludge and apparatus therefor enables substantially reducing the volume of excess sludge easily with economic advantage.