Method for improving ultraviolet radiation disinfection of water using aqueous silver

• US 6,982,039 B1
• Filed: 02/19/2004
• Issued: 01/03/2006
• Est. Priority Date: 02/19/2004
• Status: Expired due to Fees

• Current Assignee: The United States Of America As Represented By The Secretary Of The Army
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: Starke, Jeffrey A., Butkus, Michael A., Labare, Michael P., Kelley, Michael B.
• Primary Examiner(s): Hoey, Betsey Morrison
• Application Number:
  US10/780,662
• Time in Patent Office: 684 Days
• Field of Search: 210/748, 210/749, 210/764
• US Class Current: 210/748.1
• CPC Class Codes: C02F 1/00 Treatment of water, waste water, or sewage C02F3/00 - C02F9/00 take precedence
• CPC Class Codes: C02F 1/001 Processes for the treatment of water whereby the filtration technique is of importance C02F1/44 takes precedence; construction of filters in general B01D24/00 - B01D41/00
• CPC Class Codes: C02F 1/283 using coal, charred products, or inorganic mixtures containing them
• CPC Class Codes: C02F 1/32 with ultraviolet light
• CPC Class Codes: C02F 1/42 by ion-exchange ion-exchange in general B01J
• CPC Class Codes: C02F 1/505 by oligodynamic treatment
• CPC Class Codes: C02F 1/76 with halogens or compounds of halogens C02F1/4674 takes precedence
• CPC Class Codes: C02F 2303/18 Removal of treatment agents after treatment
• CPC Class Codes: C02F 9/00 Multistage treatment of water, waste water or sewage

Abstract

A method of disinfecting water is provided including treating water by irradiating the water with ultraviolet light and introducing silver ions to the water. The water may be treated by either initially irradiating the water with ultraviolet light followed by introducing silver ions to the water or by introducing silver ions to the water and thereafter exposing the silver ion-containing water to ultraviolet light.

Claims

1. A method for treating water to disinfect pathogens, including the inactivation of viruses, comprising introducing silver ions to the water and thereafter exposing the silver ion-containing water to ultraviolet light having a fluence of about 1 mJ/cm² to about 200 mJ/cm².

2. The method of disinfecting water of claim 1 wherein the ultraviolet light has a wavelength of about 200 nanometers to about 300 nanometers.

3. The method of disinfecting water of claim 1 wherein the ultraviolet light has a wavelength of about 254 nanometers.

4. The method of disinfecting water of claim 1 wherein silver ions are present as silver nitrate.

5. The method of disinfecting water of claim 1 wherein silver ions are left to remain in the treated water.

6. The method of disinfecting water of claim 1 wherein silver ions are removed from the treated water.

7. The method of disinfecting water of claim 1 wherein the water being treated is drinking water.

8. The method of disinfecting water of claim 1 wherein the water being treated is waste water.

9. The method of disinfecting water of claim 1 wherein the concentration of silver ions in the water is about 0.001 mg/L to about 10.0 mg/L.

10. The method of disinfecting water of claim 1 wherein the concentration of silver ions in the water is about 0.01 mg/L to about 0.5 mg/L.

11. The method of disinfecting water of claim 1 wherein the concentration of silver ions in the water is about 0.08 mg/L to about 0.1 mg/L.

12. The method of disinfecting water of claim 1 wherein the silver is introduced to the water using electrochemical generation.

13. The method of disinfecting water of claim 1 wherein the silver is introduced to the water using a silver-containing ion exchange column.

14. The method of disinfecting water of claim 1 wherein in addition to a virus, the water being treated contains at least one pathogen selected from the group consisting of bacteria, cyanobacteria, subviral pathogens, entervirulent Escherichia coli group, algae, fungi, and protozoa.