FRESH WATER PRODUCTION METHOD

WIPO Patent Application WO/2024/070576

A1

The present invention provides a means for suppressing the progression of fouling of a semipermeable membrane, such as when fresh water is obtained by desalination of seawater, salt water, or the like using a membrane or when water for reuse is obtained by purification of processed wastewater, industrial effluent, or the like. This fresh water production method comprises: a membrane treatment step in which semipermeable membrane supply water is treated using a semipermeable membrane so that said water is separated into permeated water and concentrated water; and at least one of (A) a pretreatment step in which water to be treated is pretreated to obtain the semipermeable membrane supply water, (B) a cleaning step in which the semipermeable membrane is cleaned, and (C) a disinfectant addition step in which a disinfectant is added to the semipermeable membrane. If the biopolymer concentration of the semipermeable membrane supply water exceeds 75 μg C/L, or if the biopolymer concentration of the concentrated water exceeds 75 × 1/(1 − R) μg C/L, R being the recovery rate of the permeated water in the membrane treatment step, running conditions for at least one of the pretreatment step, the cleaning step, and the disinfectant addition step are added or strengthened.

HANADA SHIGEHISA (JP)
HANAKAWA MASAYUKI (JP)
SHIMURA SHUN (JP)

PCT/JP2023/032767

April 04, 2024

September 07, 2023

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TORAY INDUSTRIES (JP)

B01D61/04; B01D61/14; B01D61/58; B01D65/02; B01D69/00; B01D69/02; C02F1/44; C02F1/52

JP2019217504A	2019-12-26
JP2016040029A	2016-03-24
JP2007014902A	2007-01-25
JP2014233658A	2014-12-15

EIKOH, P.C. (JP)

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