Abstract: The present invention is directed to an electrochemical device for at least partially removing or reducing a target ionic species from an aqueous solution using faradaic immobilization, the electrochemical device including at least one first electrode and at least one second electrode with different void fraction and surface area properties, due to differences in void fraction (also referred to as void ratio) of the at least one first and the at least one second electrode, water flows through an electrode with a high porosity, while the aqueous solution does not flow through an electrode with a low porosity. The asymmetry of the electrodes provides a desired voltage distribution across the device, which equates to a different voltage at each electrode, to control the speciation of the target ionic species at the anode and the cathode.

Abstract: Applicant's faradic porosity cell combines adsorption (physical and capacitive) and faradic immobilization of a target species by optimizing electrode porosity, applied E, and Pourbaix operating regions. The optimization parameters are (i) physical adsorption; (ii) capacitive adsorption; (iii) electrochemical pH modulation; (iv) electrochemical peroxide (H2O2) generation; (v) electrodeposition (e.g., electroplating, electrophoretic deposition); (vi) electrochemical oxidation or reduction; (vii) precipitation; (viii) pore mouth diameter profile, and (ix) electrode spacing, and (xi) flow-by vs. flow-through vs. carbon block cell design.