received by the International Bureau on 19 January 2016 (19.01 .2016)

We claim:

1. A recharger, comprising:

a fluid source configured to contain at least one recharging fluid, wherein the fluid source is fluidly connectable to at least one rechargeable sorbent module for use in sorbent dialysis; and a fluid flow path fluidly connecting the fluid source and the rechargeable sorbent module; wherein the recharging fluid flows from the fluid source into an inlet of the rechargeable sorbent module, and then out of an outlet of the rechargeable sorbent module in the fluid flow path.

2. The recharger of claim 1 , wherein the recharger is configured to releasably hold at least one rechargeable sorbent module and the rechargeable sorbent module contains zirconium phosphate.

3. The recharger of claim 1, further comprising multiple fluid sources each containing at least one recharging fluid, wherein the recharging fluid flows from each of the fluid sources into the inlet of the rechargeable sorbent module, and then out of the outlet of the rechargeable sorbent module.

4. The recharger of claim 3, further comprising a mixer positioned in the fluid flow path in between the at least two fluid sources and the rechargeable sorbent module, such that the recharging fluid flows from each fluid source is mixed prior to the recharging fluid flowing into the rechargeable sorbent module.

5. The recharger of claim 1, further comprising a heater to heat the recharging fluid.

6. The recharger of claim 5, wherein the heater heats the recharging fluid in the fluid source.

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7. The recharger of claim 5, wherein the heater is positioned in the fluid flow path between the fluid source and the rechargeable sorbent module, such that the recharging fluid flows from the fluid source, through the heater, and then into the rechargeable sorbent module.

8. The recharger of claim 1, further comprising a water source fluidly connected to the flow path, wherein water from the water source flows into rechargeable sorbent module in the flow path.

9. The recharger of claim 1, further comprising at least one sensor to measure a characteristic of the recharging fluid.

10. The recharger of claim 9, wherein the sensor is a conductivity sensor.

11. The recharger of claim 1, wherein the fluid source is a storage tank.

12. The recharger of claim 11, wherein the storage tank contains the recharging fluid to recharge multiple rechargeable sorbent modules.

13. The recharger of claim 1, wherein the recharger is configured to releasably hold at least one rechargeable sorbent module, the rechargeable sorbent module fluidly connectable to the fluid source.

14. The recharger of claim 3, wherein a first fluid source contains a sodium salt, a second fluid source contains a base and a third fluid source contains an acid.

15. The recharger of claim 1, wherein any one of a) through g):

a) the fluid source contains sodium chloride, sodium acetate, and acetic acid,

b) the recharger comprises a first fluid source and a second fluid source, wherein the first fluid source contains sodium chloride and sodium acetate, and the second fluid source contains acetic acid;

61 c) the recharger comprises a first fluid source, a second fluid source, and a third fluid source, wherein the first fluid source contains a sodium salt, the second fluid source contains sodium hydroxide, and the third fluid source contains acetic acid;

d) the recharger comprises a first fluid source, a second fluid source, and a third fluid source, wherein the first fluid source contains a saturated solution of sodium chloride, the second fluid source contains a base, and the third fluid source contains an acid;

e) the recharger comprises a first fluid source and a second fluid source, wherein the first fluid source contains sodium chloride and sodium diacetate and the second fluid source contains acetic acid;

f) the recharger comprises a first fluid source, a second fluid source, and a third fluid source, wherein the first fluid source contains a sodium salt, the second fluid source contains sodium acetate and the third fluid source contains acetic acid; and

g) the recharger comprises a first fluid source, and a second fluid source, wherein the first fluid source contains a sodium salt and a base, and the second fluid source contains an acid.

16. The recharger of claim 1, further comprising at least one pump to control the recharging fluid flowing from the fluid source into the fluid flow path.

17. The recharger of claim 4, further comprising a heat exchanger, the heat exchanger comprising at least two compartments, wherein the recharging fluid flows from the fluid source into a first compartment of the heat exchanger prior to entering into the rechargeable sorbent module, and the recharging fluid flows into a second compartment of the heat exchanger after flowing out of the rechargeable sorbent module.

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18. The recharger of claim 1, wherein the recharger is configured to releasably hold at least one rechargeable sorbent module and the rechargeable sorbent module contains zirconium oxide.

19. A method of recharging zirconium phosphate, comprising:

passing a single solution through the zirconium phosphate for ion exchange, wherein passing the single solution through the zirconium phosphate results in zirconium phosphate that will maintain a substantially consistent pH in a dialysate used during dialysis.

20. The method of claim 19, wherein the single solution comprises a sodium salt/buffer solution.

21. The method of claim 19, wherein the pH value of the single solution is predetermined according to a pH profile desired during a next therapy session.

22. The method of claim 19, wherein the single solution is generated through mixing a first solution having a predetermined sodium concentration and a second solution having a predetermined acid concentration.

23. The method of claim 22, wherein the first solution consisting essentially of sodium acetate and sodium chloride and the second solution is an acetic acid solution.

24. The method of claim 22, wherein the first solution and the second solution each are introduced into a mixer at a predetermined concentration.

25. The method of claim 22, further comprising controlling a temperature of the single solution.

26. The method of claim 25, wherein the temperature of the single solution is controlled by controlling a temperature of the first solution and the second solution prior to mixing.

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27. The method of claim 25, wherein the temperature of the single solution is controlled by controlling a heater to heat the solution after mixing.

28. The method of claim 19, wherein one or more components of the single solution are contained in a single fluid source to provide for one or more rechargers in the recharging.

29. The method of claim 22, wherein a third solution is mixed with the first solution and the second solution to generate the single solution for the recharging.

30. The method of claim 22, wherein the first and second solutions are mixed in a recharger used for the recharging of the zirconium phosphate.

31. The method of claim 19, wherein at least one of conductivity and pH of the single solution is measured.

32. The method of claim 19, further comprising adding an acid solution to the zirconium phosphate after the single solution passes through the zirconium phosphate.

33. The method of claim 19, wherein the zirconium phosphate is contained in a sorbent cartridge for use in sorbent dialysis.

34. The method of claim 33, wherein the zirconium phosphate is contained within a reusable module, and wherein the reusable module is detachable from the sorbent cartridge.

35. The method of claim 34, wherein the reusable module further contains zirconium oxide.

36. The method of claim 19, wherein the method is carried out using a recharger.

37. A solution for recharging zirconium phosphate, comprising a combination of at least one sodium salt and at least one acid, the solution having a predetermined pH value that results in a substantially consistent pH in a dialysate passing through the zirconium phosphate after the solution is used for recharging zirconium phosphate.

38. The solution of claim 37, wherein the solution is selected from the group consisting of sodium acetate /acetic acid solution, glycolic/glycolate solution, citric/citrate solution, propionate/propionic solution, phosphate-monobasic solution, or any combination thereof.

39. The solution of claim 37, wherein the solution consists essentially of sodium chloride, sodium acetate and acetic acid.

40. The solution of claim 39, wherein concentrations of the sodium chloride, the sodium acetate, and the acetic acid are about 3.60M, 0.40M , and 0.40M, respectively, or about 3.88M, 0.12M, and 0.40M, respectively.