Desalination system and method

Abstract

A desalination system comprises at least one desalination cell. The at least one desalination cell comprises first and second electrodes, an anion exchange layer and a cation ion exchange layer disposed on the respective first and second electrodes, and a spacer disposed between the first and second electrodes. The at least one desalination cell further comprises an ion exchange resin disposed between the first and second electrodes. A desalination system and a method for removing ions from an aqueous stream are also presented.

We claim: 
     
         1 . A desalination system for ion removal from an aqueous stream, comprising:
 a desalination device comprising:
 first and second electrodes; 
 at least one bipolar electrode disposed between the first and second electrodes; 
 a plurality of spacers disposed between each pair of the adjacent electrodes; 
 anion and cation exchange layers disposed on the respective electrodes of each pair of the adjacent electrodes; and 
 ion exchange resin disposed between each pair of adjacent electrodes. 
   
     
     
         2 . The desalination system of  claim 1 , wherein the ion exchange resin comprises a mixture of anion exchange resin beads and cation exchange resin beads. 
     
     
         3 . The desalination system of  claim 2 , wherein a proportion of volumes of the anion exchange resin beads and the cation exchange resin beads is 1:1. 
     
     
         4 . The desalination system of  claim 1 , wherein a distance between each pair of adjacent electrodes is in a range of from about 2 mm to about 20 mm. 
     
     
         5 . The desalination system of  claim 4 , wherein the distance between each pair of adjacent electrodes is about 8 mm. 
     
     
         6 . A method for removing ions from an aqueous stream, comprising:
 passing a first feed stream through an ion exchange resin disposed between an anion exchange layer and a cation exchange layer disposed on respective first and second electrodes of a desalination cell in a charging state of the desalination cell to produce an effluent stream; and   passing a second feed stream through the ion exchange resin to carry ions removed from the first feed stream out of the desalination cell in a discharging state of the desalination cell to produce a concentrate stream.   
     
     
         7 . The method of  claim 6 , further comprising introducing the effluent stream into an EDI apparatus for further processing. 
     
     
         8 . The method of  claim 6 , further comprising redirecting the concentrate stream into the second feed stream. 
     
     
         9 . The method of  claim 6 , wherein the first feed stream acts as the second feed stream in the discharging state of the desalination cell. 
     
     
         10 . The method of  claim 6 , wherein the ion exchange resin comprises an anion exchange resin beads and a cation exchange resin beads mixed with the anion exchange resin beads, and wherein a proportion of volumes of the anion exchange resin beads and the cation exchange resin beads is 1:1. 
     
     
         11 , The method of  claim 6 , wherein a distance between the first and second electrodes is in a range of from about 2 mm to about 20 mm. 
     
     
         12 . The method of  claim 6 , wherein a distance between the first and second electrodes is about 8 mm.