Electrodialysis systems with decreased concentration gradients at high recovery rates

1. An electrodialysis system comprising:

a plurality of electrodialysis devices, wherein each electrodialysis device of the plurality of electrodialysis devices comprises a product inlet stream, a product outlet stream, a brine inlet stream, and a brine outlet stream,

wherein the product inlet stream for a first electrodialysis device comprises the brine outlet stream of a second electrodialysis device.

2. The system of claim 1 , comprising a feed stream, wherein the brine inlet stream for the second electrodialysis device comprises the feed stream.

3. The system of claim 2 , wherein the brine inlet stream of the first electrodialysis device comprises the outlet stream of a brine tank, and the inlet stream of the brine tank comprises the brine outlet stream of the first electrodialysis device.

4. The system of claim 2 , wherein the product inlet stream of the second electrodialysis device comprises the product outlet stream of the first electrodialysis device.

5. The system of claim 2 , wherein an ionic concentration of the brine outlet stream of the second electrodialysis device is greater than an ionic concentration of the feed stream.

6. The system of claim 2 , wherein an ionic concentration of the product inlet stream of the first electrodialysis device is greater than an ionic concentration of the feed stream.

7. The system of claim 1 , comprising a feed stream, wherein the brine inlet stream for a third electrodialysis device comprises the feed stream.

8. The system of claim 7 , wherein the third electrodialysis device is between the first electrodialysis device and the second electrodialysis device.

9. The system of claim 7 , wherein the brine inlet stream of the second electrodialysis device comprises the brine outlet stream of the third electrodialysis device.

10. The system of claim 7 , wherein the product inlet stream of the third electrodialysis device comprises the product outlet stream of the first electrodialysis device.

11. The system of claim 1 , wherein a first portion of a feed stream is the brine inlet stream for the second electrodialysis device and a second portion of the feed stream is the brine inlet stream for a third electrodialysis device.

12. The system of claim 11 , wherein the product inlet stream for the first electrodialysis device comprises the brine outlet stream of the second electrodialysis device and the brine outlet stream of the third electrodialysis device.

13. The system of claim 1 , wherein an ionic concentration of the brine inlet stream of the second electrodialysis device is less than 10 times an ionic concentration of the product inlet stream of the second electrodialysis device.

14. The system of claim 1 , wherein the electrodialysis system is configured to remove at least one of arsenic ions, fluoride ions, perchlorate ions, lithium ions, gold ions, or silver ions.

15. A method of purifying water comprising:

routing a brine outlet stream of a second electrodialysis device of a plurality of electrodialysis devices to a first electrodialysis device of the plurality of electrodialysis devices, wherein a product inlet stream of the first electrodialysis device comprises a brine outlet stream of the second electrodialysis device.

16. The method of claim 15 , comprising:

routing a brine inlet stream of the second electrodialysis device, wherein the brine inlet stream of the second electrodialysis device comprises a feed stream.

17. The method of claim 16 , comprising routing a brine inlet stream of the first electrodialysis device, wherein the brine inlet stream of the first electrodialysis device comprises a brine outlet stream of a brine tank, and a brine inlet stream of the brine tank comprises a brine outlet of the first electrodialysis device.

18. The method of claim 16 , comprising routing a product inlet stream of the second electrodialysis device, wherein the product inlet stream of the second electrodialysis device comprises a product outlet stream of the first electrodialysis device.

19. The method of claim 16 , wherein an ionic concentration of the brine outlet stream of the second electrodialysis device is greater than an ionic concentration of the feed stream.

20. The method of claim 15 , comprising:

routing a brine inlet stream of a third electrodialysis device, wherein the brine inlet stream of the third electrodialysis device comprises a feed stream.

21. The method of claim 20 , wherein the third electrodialysis device is positioned between the first electrodialysis device and the second electrodialysis device.

22. The method of claim 20 , wherein a brine inlet stream of the second electrodialysis device comprises a brine outlet stream of the third electrodialysis device.

23. The method of claim 20 , comprising routing a product inlet stream of the third electrodialysis device, wherein the product inlet stream of the third electrodialysis device comprises a product outlet stream of the first electrodialysis device.

24. The method of claim 15 , comprising routing a first portion of a feed stream and a second portion of the feed stream, wherein the first portion of the feed stream is a brine inlet stream for the second electrodialysis device, and the second portion of the feed stream is a brine inlet for a third electrodialysis device.

25. The method of claim 24 , wherein the product inlet stream for the first electrodialysis device comprises the brine outlet stream of the second electrodialysis device and a brine outlet stream of the third electrodialysis device.

26. The method of claim 15 , wherein an ionic concentration of a brine inlet stream of the second electrodialysis device is less than 10 times an ionic concentration of a product inlet stream of the second electrodialysis device.

27. The method of claim 15 , wherein the method of purifying water is configured to remove at least one of arsenic ions, fluoride ions, perchlorate ions, lithium ions, gold ions, or silver ions.