Title:
FORWARD OSMOSIS WATER TREATMENT METHOD AND APPARATUS
Document Type and Number:
Japanese Patent JP2021159874
Kind Code:
A
Abstract:
To provide a filtration method capable of smoothly performing membrane filtration by lowering the concentration of a thermosensitive agent in a diluted solution with a small amount of heat.SOLUTION: A forward osmosis water treatment method comprises: a positive osmosis step in which treated water 21 containing salts is brought into contact with a thermosensitive agent aqueous solution 12 having a cloud point via a semipermeable membrane; a first heating step in which a diluted thermosensitive agent aqueous solution 24 is heated to a temperature above the cloud point of the thermosensitive agent aqueous solution; a first gravity separation step in which the diluted thermosensitive agent aqueous solution, which has been phase-separated into a first concentrated solution 23 phase and a first diluted solution 26 phase, is separated into a first concentrated solution layer and a first diluted solution layer; a second heating step in which the separated first diluted solution is heated to the cloud point or more; a second gravity separation step in which the first diluted solution, which has been phase-separated into a second concentrated solution 33 phase and a second diluted solution 32 phase, is gravitationally separated into a second concentrated solution layer and a second diluted solution layer; a cooling and circulation step in which the first concentrated solution separated by the first gravity separation step is cooled to a temperature equal to or lower than the cloud point of the thermosensitive agent aqueous solution and then circulated to the positive osmosis step for reuse as the thermosensitive agent aqueous solution; a membrane filtration step in which the second diluted solution separated by the second gravity separation step is treated by a finishing membrane to obtain membrane filtered water and finished membrane concentrated water.SELECTED DRAWING: Figure 1
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Inventors:
KUNUGI AKIRA
TSUJI TAKESHI
FUCHIGAMI KOJI
TOMURA KEIJI
SATO YUYA
OSATO AYA
EGAWA TAKUYA
TSUJI TAKESHI
FUCHIGAMI KOJI
TOMURA KEIJI
SATO YUYA
OSATO AYA
EGAWA TAKUYA
Application Number:
JP2020065473A
Publication Date:
October 11, 2021
Filing Date:
April 01, 2020
Export Citation:
Assignee:
JFE ENG CORP
International Classes:
B01D61/00; C02F1/44; B01D61/58
Attorney, Agent or Firm:
Masahiro Tanaka