| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an organic wastewater treatment method and an organic wastewater treatment apparatus which can eliminate excess sludge at a low cost without heating and temperature control. <P>SOLUTION: Organic wastewater is biologically denitrified in a biological treatment tank 3 having an anaerobic state and an aerobic state. The biologically treated water is subjected to solid-liquid separation in a solid-liquid separation tank 4 into microorganism-containing sludge (microorganism sludge) and treated water. The microorganism sludge is concentrated in a concentration tank 5. The concentrated microorganism sludge in the anaerobic state is mixed with organic wastewater at the upstream stage of the biological treatment tank 3 or in the anaerobic area of the biological treatment tank 3 to anaerobically perform methane fermentation and organic acid fermentation, which promotes the volume reduction of the sludge, and advances softening/destruction of the shells of the microorganism-containing sludge obstructing the sludge volume reduction. In the aerobic area of the biological treatment tank 3, the contents of the microorganism sludge whose shells have been destroyed are used as a BOD source for aerobic bacteria to be reduced, and are self-digested to be reduced. The biologically treated water is introduced into the solid-liquid separation tank 4. A series of such treatment is repeated to repeatedly reduce the volume of the sludge without heating and temperature control. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
