Claims for Patent: 5,238,576

Summary for Patent: 5,238,576

Title:	Ion exchange device for purifying water, process for manufacturing it and its use for removing nitrates and/or nitrates from water
Abstract:	The present invention relates to an ion exchange device for purifying water by reducing the nitrite and/or nitrate content, consisting of at least one container with a basic anion exchanger in chloride and/or sulphate form arranged therein and at least one additional basic anion exchanger layer in hydroxyl form or a hydroxyl-group-containing layer, in which the anion exchanger layers are arranged one behind the other directly and/or with the interposition of an intermediate layer and the anion exchange layer(s) in chloride and/or sulphate form is/are arranged not as a mixture but in (a) separate layer(s). The chloride and/or sulphate containing layer is arranged near or beneath the inlet aperture, preferably beneath the filter layer and/or (in the direction of flow of the water) in front of the anion exchange layer in the form of hydroxyl or containing hydroxyl groups. This invention also relates to processes for manufacturing and for using the ion exchange device to remove nitrates and/or nitrates from water.
Inventor(s):	Affonso; Alvaro (D-6380 Bad Homburg v.d.H., DE)
Assignee:
Application Number:	07/663,904
Patent Claims:	1. An ion exchange device for selectively decreasing the nitrite and nitrate content of water, said device comprising at least one exchange container containing first and second basic anion exchange layers, said first anion exchange layer being selected from the group consisting of basic anion exchange material in chloride form, basic anion exchange material in sulfate form, and a combination of separate sublayers of basic anion exchange material in chloride and sulfate form, and said second basic anion exchange layer being selected from the group consisting of basic anion exchange material in hydroxyl form and hydroxyl group-containing anion exchange material, wherein said second basic anion exchange layer is a weakly basic material selected from the group consisting of anion exchange materials containing more than 50% tertiary amino groups and anion exchange materials containing mixed hydroxyl groups and chloride groups. 2. An ion exchange device according to claim 1, wherein at least one intermediate filter layer is interposed between said first and second basic anion exchange layers. 3. An ion exchange device according to claim 1, wherein said first basic anion exchange layer directly precedes said second basic anion exchange layer. 4. An ion exchange device according to claim 1, wherein an activated carbon-containing filter layer is provided preceding said first basic anion exchange layer. 5. An ion exchange device according to claim 4, wherein said activated carbon-containing filter layer contains finely divided plastic particles selected from the group consisting of polyolefins and fluoropolymers. 6. An ion exchange device according to claim 5, wherein said plastic particles have a mean particle diameter of 0.01 to 100 .mu.m. 7. An ion exchange device according to claim 1, wherein said first and second basic anion exchange layers are arranged such that water flowing through said device passes first through said first layer and subsequently through said second layer. 8. An ion exchange device according to claim 1, wherein said second basic anion exchange layer is weakly basic. 9. An ion exchange device according to claim 1, wherein said second basic anion exchange layer is a weakly basic anion exchange material containing more than 65% tertiary amino groups. 10. An ion exchange device according to claim 1, wherein said second basic anion exchange layer is a medium strongly or strongly basic anion exchange material and said second and first basic anion exchange layers, respectively, are present in a volume ratio of 0.05:1 to 0.8:1. 11. An ion exchange device according to claim 10, wherein said second and first basic anion exchange layers are present in a volume ratio of 0.1:1 to 0.6:1. 12. An ion exchange device according to claim 1, wherein said second basic anion exchange layer is a weakly basic anion exchange material and said second and first basic anion exchange layers, respectively, are present in a volume ratio of 0.3:1 to 0.9:1. 13. An ion exchange device according to claim 12, wherein said second and first basic anion exchange layers are present in a volume ratio of 0.4:1 to 0.7:1. 14. A process for producing an ion exchange device for selectively removing nitrate and nitrite from water, said process comprising providing separate first and second anion exchange layers in a suitable ion exchange container, said first basic anion exchange layer being selected from the group consisting of basic anion exchange material in chloride form, basic anion exchange material in sulfate form, and a combination of separate sublayers of basic anion exchange material in chloride and sulfate form, and said second ion exchange layer being selected from the group consisting of basic anion exchange material in hydroxyl form and hydroxyl group-containing anion exchange material, wherein said second basic anion exchange layer is a weakly basic material selected from the group consisting of anion exchange materials containing more than 50% tertiary amino groups and anion exchange materials containing mixed hydroxyl groups and chloride groups. 15. A process according to claim 14, wherein an activated carbon-containing filter layer is provided in said container arranged such that water flowing through said container first flows through said filter layer and thereafter through said first and second basic anion exchange layers. 16. A process according to claim 14, wherein the ion exchange material of at least one of said first and second anion exchange layers in the container is moistened or wet, and the ion exchange material of the other of said first and second anion exchange layers is thereafter introduced into the container to form a separate layer. 17. A process according to claim 16, wherein an anion exchange material selected from the group consisting of the basic hydroxyl group-containing anion exchange material of the second anion exchange layer and the basic sulfate group containing anion exchange material of the first anion exchange layer is moistened or wet with sterile water prior to introduction into the container. 18. A process according to claim 14, wherein the ion exchange device comprises a series of at least two ion exchange containers arranged such that water flows in a given direction first through one and then through another of said containers, and said second basic anion exchange layer is provided in a downstream one of said containers while said first basic anion exchange layer is provided in a preceding anion exchange container in the direction of water flow. 19. A method of selectively removing nitrate and nitrite from water comprising the steps of passing the water through first and second basic anion exchange layers, said first anion exchange layer being selected from the group consisting of basic anion exchange material in chloride form, basic anion exchange material in sulfate form, and a combination of separate sublayers of basic anion exchange material in chloride and sulfate form, and said second basic anion exchange layer being selected from the group consisting of a basic anion exchange material in hydroxyl form and a hydroxyl group-containing anion exchange material, wherein said second basic anion exchange layers is a weakly basic material selected from the group consisting of anion exchange materials containing more than 50% tertiary amino groups and anion exchange materials containing mixed hydroxyl groups and chloride groups, whereby nitrate and nitrite are removed from the water to produce water of improved drinking quality. 20. A method according to claim 19, wherein the water is first passed through an activated carbon-containing filter, then through said first basic anion exchange layer, and thereafter through said second basic anion exchange layer.

Details for Patent 5,238,576

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Merck Sharp & Dohme Corp.	ZOSTAVAX	zoster vaccine live	For Injection	125123	05/25/2006		2010-08-24