Title:
CLEANING AGENT, CLEANING LIQUID AND CLEANING METHOD FOR AROMATIC POLYAMIDE REVERSE OSMOSIS MEMBRANES
Document Type and Number:
WIPO Patent Application WO/2023/053504
Kind Code:
A1
Abstract:
The present invention provides a cleaning agent, a cleaning liquid and a cleaning method, which are capable of effectively removing a contaminant that is not able to be sufficiently removed by conventional cleaning liquids in cases where aromatic polyamide reverse osmosis membranes used in water treatments are contaminated and the performances of the aromatic polyamide reverse osmosis membranes such as the permeation flux and the desalination rate are deteriorated. The present invention provides a cleaning agent for aromatic polyamide reverse osmosis membranes, the cleaning agent being composed of an aqueous solution which has a pH of 13 or more and contains a stabilized halogen, a chelating agent that contains one or more substances selected from among aliphatic carboxylic acids containing no amino group, phosphonic acid compounds containing no amino group, polyphosphoric acids and salts thereof, and an alkaline agent. According to the present invention, an aromatic polyamide reverse osmosis membrane is cleaned with use of a cleaning liquid that is composed of an aqueous solution of this cleaning agent. A chloramine compound which is obtained by mixing a compound having a primary amino group with hypochlorous acid and/or a hypochlorite is suitable for use as the stabilized halogen.
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Inventors:
FUJII AKIHIRO (SG)
WONG XIN YEE (SG)
WONG XIN YEE (SG)
Application Number:
PCT/JP2022/011877
Publication Date:
April 06, 2023
Filing Date:
March 16, 2022
Export Citation:
Assignee:
KURITA WATER IND LTD (JP)
International Classes:
B01D61/10; B01D65/06; B01D71/56; C11D1/02; C11D3/20; C11D3/26; C11D3/34; C11D3/36; C11D17/08
Foreign References:
| JP2015097991A | 2015-05-28 | |||
| JP2008229418A | 2008-10-02 | |||
| JP2016215125A | 2016-12-22 | |||
| JP2008132421A | 2008-06-12 | |||
| JP2015097991A | 2015-05-28 | |||
| JP2021159591A | 2021-10-11 |
Attorney, Agent or Firm:
SHIGENO, Tsuyoshi et al. (JP)
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