Title:
METHOD FOR MEMBRANE SEPARATION
Document Type and Number:
WIPO Patent Application WO/2013/005787
Kind Code:
A1
Abstract:
[Problem] To efficiently prevent permeation-membrane clogging at low cost with a small chemical amount to stably treat water for long while preventing membrane deterioration and trihalomethane generation, even when the water contains a large number of viable cells and is in a highly slimy condition.
[Solution] When water to be treated in which the viable cell number (logCFU/mL) is 3 or larger is treated by membrane separation while intermittently adding a combined-chlorine agent which contains a sulfamic acid compound, the following periods are repeated: a non-addition water-supply period in which the water is supplied for 6-120 hours without adding the combined-chlorine agent; and an intermittent-addition water-supply period which is conducted in the beginning of biofilm formation and in which the water is supplied for 0.5-40 hours while adding the combined-chlorine agent in a concentration sufficient to remove the biofilm. During the intermittent-addition water-supply period, the concentration of the combined-chlorine agent is regulated to 0.5-20 mg/L in terms of total chlorine concentration.
Inventors:
NAKAMURA TAEKO (JP)
KOWATA KENJI (JP)
MATSUMOTO KATSUMI (JP)
KOWATA KENJI (JP)
MATSUMOTO KATSUMI (JP)
Application Number:
PCT/JP2012/067155
Publication Date:
January 10, 2013
Filing Date:
July 05, 2012
Export Citation:
Assignee:
KURITA WATER IND LTD (JP)
NAKAMURA TAEKO (JP)
KOWATA KENJI (JP)
MATSUMOTO KATSUMI (JP)
NAKAMURA TAEKO (JP)
KOWATA KENJI (JP)
MATSUMOTO KATSUMI (JP)
International Classes:
C02F1/44; B01D61/08; B01D65/08; C02F1/50; C02F1/76
Foreign References:
| JP2010201312A | 2010-09-16 | |||
| JP2000042544A | 2000-02-15 | |||
| JP2002320968A | 2002-11-05 | |||
| JPH0938648A | 1997-02-10 | |||
| JP2008012424A | 2008-01-24 | |||
| JP2006263510A | 2006-10-05 |
Attorney, Agent or Firm:
YANAGIHARA, SHIGERU (JP)
Shigeru Yanagihara (JP)
Shigeru Yanagihara (JP)
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Claims: