Continuous separation of radionuclides by shock electrodialysis

A system for separating radioactive nuclides, the system comprising:

• a source of an aqueous radioactive liquid including radioactive nuclides, including cobalt (2+) ions and monovalent cations, wherein the aqueous radioactive liquid has a total salt concentration of less than 0.1 mM;
• a feed conduit for liquid flow from the source of aqueous radioactive liquid;
• a shock electrodialysis device configured to receive the aqueous radioactive liquid from the feed conduit and including:
• a chamber including:
• respective inlets for:
• the aqueous radioactive liquid, wherein the inlet for the radioactive liquid is in fluid communication with the feed conduit from the source;
• an anolyte;
• and
• a catholyte;
• and
• respective outlets for:
• purified water;
• a brine that includes the radioactive nuclides;
• the anolyte;
• and
• the catholyte;
• a porous anode contained in the chamber and configured for flow of the anolyte therethrough;
• a porous cathode contained in the chamber and configured for flow of the catholyte therethrough;
• at least two of the following functioning as ion separators:
• an ion-selective boundary;
• the anode being configured for ion separation;
• and
• the cathode being configured for ion separation,
• wherein the ion separators are configured to selectively pass at least some cations, wherein a channel for flow of the aqueous radioactive liquid from the feed conduit is defined between the ion separators, and wherein the anode and the cathode are configured to drive ionic current in the aqueous radioactive liquid across the channel when the aqueous radioactive liquid fills the channel, and wherein the ion separator is configured to conduct the ionic current;
• and
• a cationic porous medium between the ion-selective boundaries in the channel, wherein the cationic porous medium has a positive surface charge to promote flow of the ionic current across the channel and production of a desalination shock with a region of purified water on one side of the desalination shock and a brine that includes the radioactive nuclides from the aqueous radioactive liquid on an opposite side of the desalination shock and to selectively concentrate the cobalt (2+) ions over monovalent cations in the brine.