Method for permeate flow path sanitization in a reverse osmosis system

Patent metadata

Field	Value
Publication number	US-10906005-B2
Application number	US-201916252123-A
Country	US
Kind code	B2
Filing date	Jan 18, 2019
Priority date	Jan 22, 2018
Publication date	Feb 2, 2021
Grant date	Feb 2, 2021

Abstract

The disclosure pertains to sanitizing the permeate flow path of a reverse osmosis system. A method of sanitizing a filtration system is disclosed that can include injecting a biocide into a permeate compartment of an operating reverse osmosis system. The method can also include maintaining pressure in a concentrate compartment of the reverse osmosis system simultaneously while injecting the biocide.

First claim

What is claimed is:

1. A method of sanitizing a filtration system, comprising:
feeding water into a concentrate compartment of an operating reverse osmosis unit;
injecting a biocide into a permeate compartment of the operating reverse osmosis unit, the operating reverse osmosis unit comprising a membrane dividing the concentrate compartment and the permeate compartment, and
allowing the water to pass through the membrane into the permeate compartment, wherein the biocide is sodium hypochlorite, sodium percarbonate, stabilized bromine, an oxidizing halogen, calcium hypochlorite, hypochlorous acid, or any combination thereof.

2. The method of claim 1 , further comprising maintaining pressure in the concentrate compartment of the operating reverse osmosis unit simultaneously while injecting the biocide.

3. The method of claim 2 , wherein the pressure is from about 50 psi to about 1500 psi.

4. The method of claim 1 , wherein the biocide is sodium hypochlorite.

5. The method of claim 1 , wherein the biocide is injected into the permeate compartment at a dosage of about 0.001 ppm to about 3000 ppm.

6. The method of claim 1 , wherein the biocide is injected into the permeate compartment at a dosage of about 0.001 ppm to about 100 ppm.

7. The method of claim 1 , wherein the operating reverse osmosis unit comprises a membrane selected from: a polyamide membrane and a cellulose acetate membrane.

8. The method of claim 1 , wherein the biocide is injected intermittently.

9. The method of claim 1 , wherein the biocide is injected into the permeate compartment via a permeate port.

10. The method of claim 1 , further comprising injecting a surfactant with the biocide.

11. The method of claim 1 , further comprising injecting a detergent with the biocide.

12. The method of claim 1 , further comprising feeding the water from the permeate compartment into a food and beverage process.

13. A method of treating water, comprising:
feeding water into a concentrate compartment of an operating reverse osmosis unit, the operating reverse osmosis unit comprising a membrane dividing the concentrate compartment and a permeate compartment;
pressurizing the water in the concentrate compartment; and
injecting a biocide into the permeate compartment,

wherein the biocide is sodium hypochlorite, calcium hypochlorite, hypochlorous acid, or any combination thereof.

14. The method of claim 13 , wherein the biocide is injected into the permeate compartment at a dosage of about 0.001 ppm to about 3000 ppm.

15. The method of claim 13 , wherein the membrane is a polyamide membrane.

16. The method of claim 13 , further comprising feeding the water from the permeate compartment into a food and beverage process.

Assignees

• Ecolab Usa Inc

Inventors

• Glanz Douglas P
• Majerle Randall
• Van'T Hul Jason

Classifications

• C02F1/441

  by reverse osmosis · CPC title

• B01D71/56

  Polyamides, e.g. polyester-amides · CPC title

• B01D2315/20

  Operation control schemes defined by a periodically repeated sequence comprising filtration cycles combined with cleaning or gas supply, e.g. aeration · CPC title

• C02F1/766

  by means of halogens other than chlorine or of halogenated compounds containing halogen other than chlorine · CPC title

• B01D71/16

  Cellulose acetate · CPC title