Method of cleaning used dialysis fluid using electrodialysis and urea oxidation

Patent metadata

Field	Value
Publication number	US-2019358385-A1
Application number	US-201916535906-A
Country	US
Kind code	A1
Filing date	Aug 8, 2019
Priority date	Dec 31, 2015
Publication date	Nov 28, 2019
Grant date	—

Abstract

A method of cleaning used dialysis fluid having urea to produce a cleaned dialysis fluid, the method including passing the used dialysis fluid having urea through a combination electrodialysis and urea oxidation cell, the cell including (i) a first set of electrodes for separation of the used dialysis fluid having urea into an acid stream and a basic stream, wherein the first set of electrodes includes an anode and a cathode; (ii) one or more second set of electrodes positioned to contact the basic stream with an electrocatalytic surface for decomposition of urea via electrooxidation, wherein the one or more second set of electrodes includes an anode and a cathode; and (iii) at least one power source to provide the first and second sets of electrodes with an electrical charge to activate the electrocatalytic surface.

First claim

1 . A method of cleaning used dialysis fluid having urea to produce a cleaned dialysis fluid, the method comprising:
passing the used dialysis fluid having urea through a combination electrodialysis and urea oxidation cell, the cell including: a first set of electrodes for separation of the used dialysis fluid having urea into an acid stream and a basic stream, wherein the first set of electrodes includes an anode and a cathode; one or more second set of electrodes positioned to contact the basic stream with an electrocatalytic surface for decomposition of urea via electrooxidation, wherein the one or more second set of electrodes includes an anode and a cathode; and at least one power source to provide the first and second sets of electrodes with an electrical charge to activate the electrocatalytic surface.

2 . The method of claim 1 , wherein the combination electrodialysis and urea oxidation cell further includes a first cell including a first bipolar membrane, a first ion exchange membrane, and a second ion exchange membrane, wherein the first ion exchange membrane is positioned adjacent to one side of the first bipolar membrane and the second ion exchange membrane is positioned adjacent to an opposite side of the first bipolar membrane, thereby forming a first compartment between the first bipolar membrane and the first ion exchange membrane and a second compartment between the first bipolar membrane and the second ion exchange membrane, and wherein the one or more second set of electrodes is positioned in the first compartment.

3 . The method of claim 2 , wherein the first ion exchange membrane is an anion exchange membrane or a cation exchange membrane.

4 . The method of claim 2 , wherein the second ion exchange membrane is an anion exchange membrane or a cation exchange membrane.

5 . The method of claim 2 , wherein the combination electrodialysis and urea oxidation cell further includes a second cell including a second bipolar membrane and a third ion exchange membrane, wherein the second cell is positioned adjacent to the first cell, and wherein the second bipolar membrane is positioned between the second ion exchange membrane of the first cell and the third ion exchange membrane, thereby forming a third compartment between the second bipolar membrane and the third ion exchange membrane, and which includes one or more third set of electrodes having an electrocatalytic surface for decomposition of urea via electrooxidation positioned between the second ion exchange membrane and the second bipolar membrane.

6 . The method of claim 5 , wherein the first, second, and third ion exchange membranes are cation exchange membranes or wherein the first, second, and third ion exchange membranes are anion exchange membranes.

7 . The method of claim 1 , wherein the combination electrodialysis and urea oxidation cell further includes a first bipolar membrane, a second bipolar membrane, a first ion exchange membrane, and a second ion exchange membrane, wherein the first ion exchange membrane and the second ion exchange membrane are positioned between the first bipolar membrane and the second bipolar membrane, thereby forming a first compartment between the first bipolar membrane and the first ion exchange membrane, a second compartment between the first ion exchange membrane and the second ion exchange membrane, and which includes a third compartment between the second ion exchange membrane and the second bipolar membrane.

8 . The method of claim 7 , wherein the first ion exchange membrane is a cation exchange membrane and the second ion exchange membrane is an anion exchange membrane.

9 . The method of claim 1 , wherein the dialysis fluid includes one or more salt selected from a sodium salt, a magnesium salt, a calcium salt, lactate, carbonate, acetate, citrate, or phosphate.

10 . The method of claim 1 , further comprising a tank for holding the used dialysis fluid.

11 . The method of claim 1 , wherein the basic stream includes NaOH.

12 . The method of claim 1 , wherein the acid stream includes HCl.

13 . The method of claim 1 , wherein the anodes of the second set of electrodes include a transition metal and/or mixtures thereof and/or alloys thereof.

14 . The method of claim 13 , wherein the transition metal includes cobalt, copper, iron, nickel, platinum, palladium, iridium, ruthenium, or rhodium.

15 . The method of claim 13 , wherein the anodes of the second set of electrodes include nickel, nickel oxide, nickel hydroxide or nickel oxide hydroxide (NiOOH).

16 . The method of claim 1 , which further includes applying a voltage difference across the cathodes and the anodes in the one or more second set of electrodes sufficient to produce nitrogen gas, carbon dioxide gas, and water.

17 . A method of cleaning used dialysis fluid having urea to produce a cleaned dialysis fluid, the method comprising:
contacting the used dialysis fluid with a first set of electrodes including an anode and a cathode to separate the used dialysis fluid into an acid stream and a basic stream; contacting the basic stream with one or more second set of electrodes including an electrocatalytic surface to decompose urea of the used dialysis fluid via electrooxidation, wherein the one or more second set of electrodes includes an anode and a cathode; and electrically charging the first and the second sets of electrodes to activate the electrocatalytic surface.

18 . The method of claim 17 , further comprising providing the first and the second sets of electrodes in a combination electrodialysis and urea oxidation cell.

19 . The method of claim 17 , further comprising applying a voltage difference across the cathode and the anode in the one or more second set of electrodes sufficient to produce nitrogen gas, carbon dioxide gas, and water.

20 . A method of cleaning used dialysis fluid having urea to produce a cleaned dialysis fluid, the method comprising:
contacting the used dialysis fluid with a first set of electrodes including an anode and a cathode to separate the used dialysis fluid into an acid stream and a basic stream; contacting the basic stream with one or more second set of electrodes including an electrocatalytic surface to decompose urea of the used dialysis fluid via electrooxidation to produce an oxidized basic stream, wherein the one or more second set of electrodes includes an anode and a cathode; electrically charging the first and the second sets of electrodes to activate the electrocatalytic surface; and placing the acid stream in fluid communication with the oxidized basic stream to neutralize pH of the cleaned dialysis fluid.

Assignees

• Baxter Int
• Baxter Healthcare Sa

Inventors

• Ding Yuanpang Samuel
• Menzel Bueno Cristian Adolfo
• Yeh Rosa

Classifications

• B01D61/445

  with bipolar membranes; Water splitting · CPC title

• C02F2101/16

  Nitrogen compounds, e.g. ammonia · CPC title

• C25F7/00

  Constructional parts, or assemblies thereof, of cells for electrolytic removal of material from objects (for both electrolytic coating and removal C25D); Servicing or operating · CPC title

• C02F1/4693

  electrodialysis · CPC title

• C25F1/00

  Electrolytic cleaning, degreasing, pickling or descaling · CPC title