WATER TREATMENT CHEMICAL FOR MEMBRANE, AND MEMBRANE TREATMENT METHOD

• US 20200129928A1
• Filed: 03/02/2018
• Published: 04/30/2020
• Est. Priority Date: 03/15/2017
• Status: Active Application

• Current Assignee: Kurita Water Industries Limited
• Original Assignee: Kurita Water Industries Limited
• Inventors: ISHII, Kazuki, IKUNO, Nozomu
• Application Number:
  US16/493,588
• Publication Number:
  US 20200129928A1
• Time in Patent Office: Days
• CPC Class Codes: B01D 2311/04 Specific process operations in the feed stream; Feed pretreatment
• CPC Class Codes: B01D 2311/12 Addition of chemical agents
• CPC Class Codes: B01D 2321/168 Use of other chemical agents
• CPC Class Codes: B01D 61/02 Reverse osmosis; Hyperfiltration ; Nanofiltration
• CPC Class Codes: B01D 61/10 Accessories; Auxiliary operations
• CPC Class Codes: B01D 65/08 Prevention of membrane fouling or of concentration polarisation
• CPC Class Codes: C02F 1/441 by reverse osmosis
• CPC Class Codes: C02F 2303/22 Eliminating or preventing deposits, scale removal, scale prevention C02F1/042, C02F1/4602, C02F5/00 take precedence
• CPC Class Codes: C07C 229/16 to carbon atoms of hydrocarbon radicals substituted by amino or carboxyl groups, e.g. ethylenediamine-tetra-acetic acid, iminodiacetic acids
• CPC Class Codes: C07F 9/3808 Acyclic saturated acids which can have further substituents on alkyl
• CPC Class Codes: C07F 9/3817 Acids containing the structure (RX)2P(=X)-alk-N...P (X = O, S, Se)
• CPC Class Codes: C09K 3/00 Materials not provided for elsewhere

Abstract

A water treatment chemical for a membrane, being is a water treatment chemical for preventing membrane contamination caused by an organic compound having a phenolic hydroxy group and including an organic amine having two or more nitrogen atoms and having five or more carboxyl groups or four or more phosphate groups. A membrane treatment method including adding the water treatment chemical for a membrane to water to be treated which contains an organic compound having a phenolic hydroxy group and then subjecting the water to be treated to membrane separation treatment.

Claims

1. A water treatment chemical for a membrane, being a water treatment chemical for preventing membrane contamination caused by an organic compound having a phenolic hydroxy group, and comprising an organic amine having two or more nitrogen atoms and having five or more carboxyl groups or four or more phosphate groups.

2. The water treatment chemical for a membrane according to claim 1, wherein the organic amine is an organic amine represented by any one of the following (1) to (3):

3. The water treatment chemical for a membrane according to claim 2, wherein n in the general formula (1), p and q in the general formula (2), and m in the general formula (3) are each an integer of 1 to 5.

4. The water treatment chemical for a membrane according to claim 1, wherein a molecular weight of the organic amine is 100 to 1000.

5. The water treatment chemical for a membrane according to claim 1, being a water treatment chemical for a reverse osmosis membrane for carrying out reverse osmosis membrane treatment of water to be treated, the water containing an organic compound having a phenolic hydroxy group, wherein a concentration of non-purgeable organic carbon in concentrated water obtained by the reverse osmosis membrane treatment is 0.01 to 100 mg/L.

6. The water treatment chemical for a membrane according to claim 5, wherein a concentration ratio of the reverse osmosis membrane is 3 times or more.

7. A membrane treatment method comprising adding the water treatment chemical for a membrane according to claim 1 to water to be treated, the water containing an organic compound having a phenolic hydroxy group, and then subjecting the water to be treated to membrane separation treatment.

8. The membrane treatment method according to claim 7, wherein the water treatment chemical for a membrane is added to the water to be treated in such a manner that the concentration of the organic amine becomes 0.01 to 20 mg/L.