Title:
FILTRATION METHOD IN WHICH POROUS MEMBRANE IS USED
Document Type and Number:
WIPO Patent Application WO/2020/100763
Kind Code:
A1
Abstract:
Provided is a filtration method having exceptional filtration properties and cleansing efficiency as well as a long service life. The present invention pertains to a filtration method characterized by including: a filtration step for passing a filtration liquid by means of external-pressure filtration through a module of a porous membrane configured from a three-dimensional mesh-structure resin, thus filtering the filtration liquid; a cleansing step for conducting backwashing in which a cleansing liquid is passed through the porous membrane from the inner-side surface of the membrane and also conducting air bubbling, thereby cleansing the outer-side surface of the porous membrane, the cleansing step being performed after the filtration step; and a discharge step for discharging the cleansing liquid remaining on the outer-side surface and in the interior of the porous membrane, the discharge step being performed after the cleansing step; the filtration method also being characterized in that, in each region of an SEM image of a membrane cross-section taken along a membrane thickness direction orthogonal to the inner-side surface of the porous membrane, the sum total area of a resin part having an area of 1 μm2 or less is 70% or higher with respect to the overall area of the resin part, and/or the sum total area of a resin part having an area of 10 μm2 or higher is 15% or less with respect to the overall area of the resin part.
Inventors:
OKAMURA DAISUKE (JP)
Application Number:
PCT/JP2019/043976
Publication Date:
May 22, 2020
Filing Date:
November 08, 2019
Export Citation:
Assignee:
ASAHI CHEMICAL IND (JP)
International Classes:
B01D65/02; B01D65/06; B01D71/32; B01D71/34; B01D71/36; C02F1/44
Domestic Patent References:
| WO2014069300A1 | 2014-05-08 |
Foreign References:
| JP2018023965A | 2018-02-15 | |||
| JP2015073916A | 2015-04-20 | |||
| JP2008253922A | 2008-10-23 |
Attorney, Agent or Firm:
AOKI, Atsushi et al. (JP)
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