This is probably painfully obvious, but I keeping getting the impression that aqueous ions can be separated spatially via electrostatic force. For example, dissolve some sodium chloride in water, and then put the container in an electric field. Wouldn't the sodium ions migrate to the negative side and the chloride ions migrate to the positive side? I also don't see why this process can't be used in the industrialized separation of elements, even though the ions repel each other, if the external field is strong enough it should be possible to separate ions on a large scale. Maybe I do not have a proper understanding on the magnitude of the "inter-ionic" forces in the solution, either way, I would like to know why electrostatic separation of ions is (presumably) not possible.