REMOVING UREA FROM SALINE WATER SOLUTIONS PARTICULARLY IN AN ARTIFICIAL KIDNEY

• US 3,617,545 A
• Filed: 03/12/1970
• Issued: 11/02/1971
• Est. Priority Date: 03/13/1969
• Status: Expired due to Term

• Current Assignee: Claude Duchesne, Jean-Claude Dubois
• Original Assignee: Claude Duchesne, Jean-Claude Dubois
• Inventors: Dubois, Jean-Claude, Duchesne, Claude
• Primary Examiner(s): Zaharna, Samih N.
• Assistant Examiner(s): Barnes, Richard
• Application Number:
  US05/019,018
• Time in Patent Office: 600 Days
• Field of Search: 210/22,321 204/18P,301
• US Class Current: 210/632
• CPC Class Codes: A61M 1/1696 with dialysate regeneration
• CPC Class Codes: A61M 1/3472 with treatment of the filtrate
• CPC Class Codes: A61M 1/3486 Biological, chemical treatment, e.g. chemical precipitation; treatment by absorbents
• CPC Class Codes: B01D 61/44 Ion-selective electrodialysis
• CPC Class Codes: B01D 61/461 comprising only a single cell, only one anion or cation exchange membrane or one pair of anion and cation membranes

Abstract

Urea is removed from ultrafiltrate or dialysate by demineralizing the saline solution thereof, hydrolyzing the urea to ammonium carbonate, removing the carbonate with a cationic exchange resin and then remineralizing the resulting solution. An electrodialyzer for employing this method is described.

Claims

2. The method of claim 1, wherein the product of (d) is contacted with an activated carbon, whereby any uric acid or creatinine present in said saline water solution is removed.

3. The method of claim 2, wherein the filtrate obtained in claim 2 is contacted with an anionic exchange resin, whereby phosphates and sulfates present in said saline water solution are removed.

4. The method of claim 1, wherein the urea of the demineralized solution is hydrolyzed with urease to ammonium carbonate in (b).

5. The method of claim 4, wherein the urease is enveloped in a capsule of a water-permeable plastic material in (b).

6. The method of claim 3, wherein the anionic exchange resin is one equilibrated with ions present in said saLine solution.

7. Apparatus for removing urea from blood comprising in combination a. an electrodialyzer comprising anode and cathode compartments separated by concentrating compartments which are separated by dilution compartments;

b. means for charging a saline water solution containing urea to a dilution compartment of said electrodialyzer;

c. a hydrolysis vessel and means for connecting the same with the exit of said dilution compartment;

d. a column of cationic exchange resin and means for connecting the same with the exit of said hydrolysis vessel;

e. and means connecting the exit of the column of (d) with concentrating compartments of said electrodialyzer.

8. Apparatus of claim 7, containing (f) a column of activated carbon and means for connecting the same with the exit of said concentrating compartments.

9. Apparatus of claim 8, containing (g) a column of an anionic exchange resin and means for connecting the same with the exit of said activated carbon column.

10. Apparatus of claim 9, wherein (c), (d), (e), (f) and (g) are contained in a single processing column.

11. Apparatus of claim 7, wherein the hydrolysis vessel contains a diaphragm which retains urease.

12. Apparatus of claim 9, wherein the anionic exchange resin is one equilibrated with ions present in said saline solution.