Title:
MEMBRANE-SEPARATION METHOD
Document Type and Number:
WIPO Patent Application WO/2012/133620
Kind Code:
A1
Abstract:
A membrane separation method in which the concentration of free chlorine is reduced and the total chlorine concentration is increased using a small amount of chemicals and a simple operation, whereby it is possible to prevent even permeable membranes having low chlorine resistance from being contaminated by slime deposition based on microbial proliferation, and to efficiently perform membrane separation over a prolonged period of time, without any reduction in the removal rate or desalination rate due to degradation of the permeable membrane. When treated water containing free chlorine is fed from L1 to a membrane separation device (4) and subjected to membrane separation by a permeable membrane (4a), one or more sulfamic acid compounds selected from the group consisting of sulfamic acid, combined-chlorine sulfamic acid, and a salt of sulfamic acid or combined-chlorine sulfamic acid are added from L2 to the treated water to convert free chlorine to combined chlorine, and a reduction agent is added as required from L6 to remove residual free chlorine and prevent slime deposition in membrane separation.
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Inventors:
KOWATA KENJI (JP)
HAYAKAWA KUNIHIRO (JP)
KAWAKATSU TAKAHIRO (JP)
HAYAKAWA KUNIHIRO (JP)
KAWAKATSU TAKAHIRO (JP)
Application Number:
PCT/JP2012/058314
Publication Date:
October 04, 2012
Filing Date:
March 29, 2012
Export Citation:
Assignee:
KURITA WATER IND LTD (JP)
KOWATA KENJI (JP)
HAYAKAWA KUNIHIRO (JP)
KAWAKATSU TAKAHIRO (JP)
KOWATA KENJI (JP)
HAYAKAWA KUNIHIRO (JP)
KAWAKATSU TAKAHIRO (JP)
International Classes:
C02F1/44; B01D61/02; B01D61/04; C02F1/58; C02F1/70
Foreign References:
| JP2010201313A | 2010-09-16 | |||
| JPH0432713B2 | 1992-06-01 | |||
| JP2010063998A | 2010-03-25 |
Attorney, Agent or Firm:
YANAGIHARA, SHIGERU (JP)
Shigeru Yanagihara (JP)
Shigeru Yanagihara (JP)
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Claims: