Patent ID: 8801910

Claim:
A method for desalination and purification of a liquid electrolyte utilizing a system that includes a liquid conduit that has an inlet port, at least one outlet port for desalinated and purified liquid, and at least one outlet port for waste liquid and that includes a first electrode and a second-electrode-and-ion-selective-boundary configuration selected from (a) a second electrode and at least one distinct ion-selective boundary and (b) a second electrode that also serves as the ion-selective boundary, wherein the ion-selective boundary has a charge and is contained in the liquid conduit adjacent to a porous medium that defines pore channels that are filled with the liquid and that have a surface charge, wherein the charge of the ion-selective boundary and surface charge of the pore channels share a sign, the method comprising: flowing a liquid including at least one charged species selected from dissolved ions, charged particles, and charged droplets into the inlet port and through the pore channels, forming a thin diffuse electrochemical double layer at an interface of the liquid and the charged surface of the pore channels in the porous medium with a liquid bulk volume beyond the double layer in the pore channels; applying a voltage differential between the electrodes across the porous medium to draw charged species in the liquid to the electrodes, wherein at least some of the charged species with a charge opposite to that of the first electrode flow to the first electrode and at least some of the charged species with a charge opposite to that of the second electrode flow to the second electrode; via the application of the voltage differential, producing brine at the electrodes by either Faradaic reactions or by capacitive charging and discharging and creating a shock in the charged-species concentration in the bulk volume of the liquid within the pore channels, wherein the concentration of the charged species in a depleted zone of the liquid bulk volume between the shock and the ion-selective boundary is substantially lower than the concentration of charged species in the liquid bulk volume between the shock and the first electrode, and wherein electric current flows primarily through the double layers or micropores in the region between the shock and the ion-selective boundary, while electric current flows primarily through the liquid bulk volume in the region between the shock and the first electrode; extracting desalinated and purified liquid from the depleted zone of the bulk volume in the porous medium by flow to the at least one outlet port for desalinated and purified liquid between the shock and the ion-selective boundary; and flowing waste liquid including charged species on an opposite side of the shock from the depleted zone, wherein at least one outlet port for waste liquid is separated across the porous medium from the at least one outlet port for desalinated and purified liquid by the shock and not by a membrane.