Silver self-regulating water purification compositions and methods

• US 6,254,894 B1
• Filed: 07/08/1999
• Issued: 07/03/2001
• Est. Priority Date: 04/05/1996
• Status: Expired due to Fees

• Current Assignee: Zodiac Pool Systems Incorporated (Fluidra, S.A.)
• Original Assignee: Zodiac Pool Care Incorporated (Fluidra, S.A.)
• Inventors: Bollinger, Mark A., Grenier, Joseph W., Souza, Therese R., Rafter, John D., Denkewicz, Raymond P. Jr.
• Primary Examiner(s): Clardy, S. Mark
• Assistant Examiner(s): PRYOR, ALTON NATHANIEL
• Application Number:
  US09/349,826
• Time in Patent Office: 726 Days
• Field of Search: 424/618, 424/682
• US Class Current: 424/618
• CPC Class Codes: A01N 2300/00 Combinations or mixtures of active ingredients covered by classes A01N27/00 - A01N65/48 with other active or formulation relevant ingredients, e.g. specific carrier materials or surfactants, covered by classes A01N25/00 - A01N65/48
• CPC Class Codes: A01N 59/16 Heavy metals; Compounds thereof
• CPC Class Codes: A61L 2/238 Metals or alloys, e.g. oligodynamic metals
• CPC Class Codes: C02F 1/505 by oligodynamic treatment
• CPC Class Codes: C02F 1/705 Reduction by metals

Abstract

The present invention relates to water purification compositions comprising silver and a second material, such as aluminum or zinc metal, to methods of treating or purifying water using this composition.

Claims

1. A method of purifying water comprising exposing the water to an effective amount of a water purification composition comprising silver and aluminum metal.

2. The method of claim 1, wherein the water purification composition further comprises zinc, copper, or mixtures thereof.

3. The method of claim 1, wherein the silver is metallic silver.

4. The method of claim 2, wherein the aluminum is alloyed with zinc, copper, or both.

5. The method of claim 1, wherein the water purification composition further comprises an inorganic oxide having a point of zero charge between about 4 and about 9.

6. The method of claim 5, wherein the inorganic oxide has a zeta potential less than or equal to about +20 mV in water having a pH of about 5.0 to about 10.

7. The method of claim 5, wherein the inorganic oxide comprises alumina.

8. The method of claim 1, wherein the silver comprises between about 0.1 and about 10 weight percent of the water purification composition.

9. The method of claim 1, wherein the aluminum metal comprises between about 2 and about 95 weight percent of the water purification composition.

10. The method of claim 1,wherein the water purification composition provides a silver ion concentration in water between about 0.01 and about 0.1 ppm when exposed to the water.

11. The method of claim 10, wherein the water purification composition provides a silver ion concentration in water between about 0.01 and about 0.05 ppm when exposed to the water.

12. The method of claim 1, wherein the silver is a source of microbiocidal silver ions in the water and the aluminum flocculates suspended material in the water.

13. The method of claim 1, wherein the composition further comprises zinc or copper.

14. The method of claim 1, wherein the composition further comprises an inorganic oxide having a zeta potential less than or equal to about +20 mV in the water being purified.

15. The method of claim 1, wherein the water is recirculated.

16. The method of claim 1, wherein the water is drinking water.

17. The method of claim 1, wherein the water comprises an oxidizing agent dissolved in the water.

18. The method of claim 14, wherein the inorganic oxide comprises alumina.

19. The method of claim 1, wherein the silver in the composition comprises silver metal in an amount between about 0.1 and about 10 weight percent of the composition.

20. The method of claim 17, wherein the oxidizing agent comprises ozone, chlorine dioxide or free available chlorine.

21. A water purification system comprising:

a water purification composition comprising silver and aluminum metal; and

an oxidizing agent or a source of an oxidizing agent.

22. The water purification system of claim 21, wherein the silver is metallic silver.

23. The water purification system of claim 21, wherein the aluminum metal is alloyed with at least one metal selected from the group consisting of zinc metal and copper metal.

24. The water purification system of claim 21, wherein the oxidizing agent is selected from the group consisting of free available chlorine, ozone, and chlorine dioxide.

25. The water purification system of claim 21, wherein the source of oxidizing agent is selected from the group consisting of dipersulfates, monopersulfates, hypochlorite salts, chlorites, peroxides, perchlorates, hypobromites, percarbonates, chlorine dioxide and permanganates.