METHOD FOR TREATING ORGANIC WASTEWATER

Title:

METHOD FOR TREATING ORGANIC WASTEWATER

Document Type and Number:

WIPO Patent Application WO/2001/062676

Kind Code:

A1

Abstract:

A method for the biological treatment of an organic wastewater which uses a biological treatment apparatus having a biological treatment tank and an activated sludge solid-liquid separation tank, characterized in that it comprises withdrawing a part of the sludge in the biological treatment tank or the activated sludge solid-liquid separation tank and admixing it with a part of a raw water, injecting an ozone gas into the resultant mixture, introducing the mixture containing ozone to a previous treatment tank to carry out an ozone treatment and a biological treatment in the previous treatment tank, introducing a treated liquor from the previous treatment tank to the latter biological treatment tank together with the residual raw water and a part of the sludge in the biological treatment tank or the activated sludge solid-liquid separation tank and at the same time introducing an exhaust gas from the previous treatment tank to the biological treatment tank, to thereby carry out a biological treatment. The method is free from the fear of death of activated sludge and allows both of the volume reduction of excess sludge and the improvement in the quality of a treated water, and further can be employed for reducing the cost for the whole waste water treatment system.

Inventors:

KATSU YOUSEI (JP)
TANAKA TOSHIHIRO (JP)
KOBAYASHI TAKUYA (JP)
ARAKAWA KIYOMI (JP)

Application Number:

PCT/JP2001/001251

Publication Date:

August 30, 2001

Filing Date:

February 21, 2001

Export Citation:

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Assignee:

EBARA CORP (JP)
KATSU YOUSEI (JP)
TANAKA TOSHIHIRO (JP)
KOBAYASHI TAKUYA (JP)
ARAKAWA KIYOMI (JP)

International Classes:

C02F3/34; C02F1/78; C02F3/12; (IPC1-7): C02F3/12; C02F3/34

Foreign References:

JPH09174071A	1997-07-08
JPS5948799U	1984-03-31
JP2000033393A	2000-02-02
JPH08103786A	1996-04-23

Other References: