Abstract: An electrochemical system includes first and second endplates and a plurality of electrochemical units disposed between the first and second endplates. Each of the plurality of electrochemical units includes a porous anode disposed in an anode compartment, a porous cathode disposed in a cathode compartment, and a center compartment disposed between and separated from the anode compartment and the cathode compartment by cation exchange membranes.

Abstract: A method of operating an electrochemical device includes periodically discharging a volume of concentrate reject in a timed batch cycle and replacing the concentrate reject with feed water. An electrochemical water treatment system includes a recycle line having a valve controlled by a control module. The control module periodically opens the valve to discharge concentrate reject from the recycle line in a batch timed cycle. The recycle line is fed with feed water to replace the discharged concentrate reject.

Abstract: A water treatment system for producing potable water and water for irrigation from saline water, the system includes an electrodialysis apparatus including one or more monovalent selective membranes and having an inlet fluidly connectable to a source of water to be treated, a diluate outlet, and a concentrate outlet, a nanofiltration apparatus positioned downstream of the electrodialysis apparatus and having an inlet fluidly connectable to the diluate outlet of the electrodialysis apparatus, a permeate outlet, and a retentate outlet, and an electrolyzer in fluid communication with one of the concentrate outlet and the retentate outlet, and configured to generate a product stream including one or more of chlorine gas, hypochlorite ion, sodium hydroxide, sulfuric acid, hydrochloric acid, or sodium hypochlorite.

Abstract: A module comprises a cell stack having a plurality of alternating ion depleting compartments and ion concentrating compartments, an inlet manifold configured to facilitate a flow of fluid into the cell stack, and a first flow distribution system, associated with the inlet manifold, including a first ramp to promote the circulation of the flow of fluid into the cell stack.

Abstract: A system for the treatment of phosphate-containing wastewater comprises a pretreatment subsystem including a mixing chamber configured to mix a potassium-based salt with the wastewater to precipitate K2SiF6 from the wastewater, a solids-liquid separator to separate the precipitated K2SiF6 from the wastewater and form a pretreated wastewater, and a mixing chamber to dilute the pretreated wastewater with raw wastewater, and a filtration subsystem including a first filtration configured to receive the pretreated wastewater and remove particles to form a first effluent, a second filtration unit remove divalent ions from the first effluent and form a second effluent, and a third filtration unit configured to remove additional dissolved solids from the second effluent and form a third effluent suitable for discharge to the environment.

Abstract: An electrochemical separation device includes a first electrode, a second electrode, a cell stack including alternating depleting compartments and concentrating compartments disposed between the first electrode and the second electrode, an inlet manifold configured to introduce a fluid to one of the depleting compartments or the concentrating compartments an outlet manifold, and one or more of a fluid flow director disposed within the inlet manifold and having a surface configured to alter a flow path of the fluid introduced into the inlet manifold and direct the fluid into the one of the depleting compartments or the concentrating compartments, and a second fluid flow director disposed within the outlet manifold and having a surface configured to alter a flow path of the fluid introduced into the outlet manifold via one of the depleting compartments or the concentrating compartments.

Abstract: Apparatuses for the generation of carbon dioxide and hydrogen from a water having a carbonate species are disclosed. The apparatus includes an anodic compartment having an anode disposed on a first side of the anodic compartment and a cathodic compartment having a cathode disposed on a first side of the cathodic compartment. The apparatus further includes a first cation permeable fluidic separator disposed on a second side of the anodic compartment and a second cation permeable fluidic separator disposed on a second side of the cationic compartment. A center compartment is defined between the first cation permeable fluidic separator and the second cation permeable fluidic separator. The apparatus further includes a flow control system configured to independently control flow of water through each of the anodic compartment, the cathodic compartment, and the center compartment. Methods of generating hydrogen, carbon dioxide, and oxygen from seawater using the apparatus are also disclosed.

Abstract: Systems for water desalination are disclosed. The systems include a source of non-potable water, a low pressure nanofiltration device, a first electrodialysis unit, a second electrodialysis unit, and recycle conduits. Methods of water desalination including directing non-potable water to a low pressure nanofiltration device, a first electrodialysis unit, and a second electrodialysis unit are also disclosed. Methods of facilitating water desalination by providing a water desalination system are also disclosed.

Abstract: An electrochemical separation device includes a first electrode, a second electrode, and a cell stack including a plurality of sub-blocks each having alternating depleting compartments and concentrating compartments and each including frame and channel portions disposed between the first electrode and the second electrode. An internal seal formed of a first material is disposed between and in contact with the channel portions between adjacent sub-blocks in the cell stack and configured to prevent leakage between depleting compartments and concentrating compartments in the adjacent sub-blocks. An external seal formed of a second material having at least one material parameter different from the first material is disposed between and in contact with the frames of the adjacent sub-blocks in the cell stack and configured to prevent leakage from an internal volume of the electrochemical separation device to outside of the electrochemical separation device.

Abstract: Self-cleaning electrochemical cells, systems including self-cleaning electrochemical cells, and methods of operating self-cleaning electrochemical cells are disclosed. The self-cleaning electrochemical cell can include a plurality of concentric electrodes disposed in a housing, a fluid channel defined between the concentric electrodes, and an electrical connector positioned at a distal end of a concentric electrode and electrically connected to the electrode. The electrical connectors may be configured to provide a substantially even current distribution to the concentric electrode and minimize a zone of reduced velocity occurring downstream from the electrical connector. The electrical connector may be configured to cause a temperature of an electrolyte solution to increase by less than about 0.5° C. while transmitting at least 100 W of power.

Abstract: An electrochemical separation device includes a first electrode, a second electrode, and a cell stack including a plurality of sub-blocks each having alternating depleting compartments and concentrating compartments and each including frame and channel portions disposed between the first electrode and the second electrode. An internal seal formed of a first material is disposed between and in contact with the channel portions between adjacent sub-blocks in the cell stack and configured to prevent leakage between depleting compartments and concentrating compartments in the adjacent sub-blocks. An external seal formed of a second material having at least one material parameter different from the first material is disposed between and in contact with the frames of the adjacent sub-blocks in the cell stack and configured to prevent leakage from an internal volume of the electrochemical separation device to outside of the electrochemical separation device.

Abstract: Self-cleaning electrochemical cells, systems including self-cleaning electrochemical cells, and methods of operating self-cleaning electrochemical cells are disclosed. The self-cleaning electrochemical cell can include a plurality of concentric electrodes disposed in a housing, for example, a cathode and an anode, a fluid channel defined between the concentric electrodes, a separator residing between the concentric electrodes, first and second end caps coupled to respective ends of the housing, and an inlet cone. The separators may be configured to localize the electrodes and dimensioned to minimize a zone of reduced velocity occurring downstream from the separator. The end caps and inlet cone may be dimensioned to maintain fully developed flow and minimize pressure drop across the electrochemical cell.

Abstract: Water filtration systems are disclosed. The water filtration systems include a regenerative media filter vessel comprising a housing, an inlet, and an outlet, a diffuser fluidly connected to the inlet and disposed within the regenerative media filter vessel, and at least one pump configured to direct water through the water filtration system. The housing of the regenerative media filter vessel comprises a concave lower portion centered about a vertical axis of the vessel. The position of the diffuser along a height of the regenerative media filter vessel is determined by at least a ratio of the height to an inner diameter of the regenerative media filter vessel and a radius of curvature of the concave lower portion. A regenerative media filter including a diffuser having asymmetrically spaced apertures is also disclosed.

Abstract: Self-cleaning electrochemical cells, systems including self-cleaning electrochemical cells, and methods of operating self-cleaning electrochemical cells are disclosed. The self-cleaning electrochemical cell can include a plurality of concentric electrodes disposed in a housing, for example, a cathode and an anode, a fluid channel defined between the concentric electrodes, a separator residing between the concentric electrodes, first and second end caps coupled to respective ends of the housing, and an inlet cone. The separators may be configured to localize the electrodes and dimensioned to minimize a zone of reduced velocity occurring downstream from the separator. The end caps and inlet cone may be dimensioned to maintain fully developed flow and minimize pressure drop across the electrochemical cell.

Abstract: An electrochemical separation device includes a first electrode, a second electrode, a cell stack including alternating depleting compartments and concentrating compartments disposed between the first electrode and the second electrode, an inlet manifold configured to introduce a fluid to one of the depleting compartments or the concentrating compartments an outlet manifold, and one or more of a fluid flow director disposed within the inlet manifold and having a surface configured to alter a flow path of the fluid introduced into the inlet manifold and direct the fluid into the one of the depleting compartments or the concentrating compartments, and a second fluid flow director disposed within the outlet manifold and having a surface configured to alter a flow path of the fluid introduced into the outlet manifold via one of the depleting compartments or the concentrating compartments.

Abstract: An electrochemical separation device includes a first electrode, a second electrode, and a cell stack including a plurality of sub-blocks each having alternating depleting compartments and concentrating compartments and each including frame and channel portions disposed between the first electrode and the second electrode. An internal seal formed of a first material is disposed between and in contact with the channel portions between adjacent sub-blocks in the cell stack and configured to prevent leakage between depleting compartments and concentrating compartments in the adjacent sub-blocks. An external seal formed of a second material having at least one material parameter different from the first material is disposed between and in contact with the frames of the adjacent sub-blocks in the cell stack and configured to prevent leakage from an internal volume of the electrochemical separation device to outside of the electrochemical separation device.

Abstract: A method of providing water suitable for irrigation use includes feeding pre-treated water to an electrodialysis apparatus, treating the pre-treated water in the electrodialysis apparatus by selectively removing either one or both of monovalent anionic and monovalent cationic species from the pre-treated water while retaining either one or both of multivalent anionic and multivalent cationic species to produce a treated water stream having a lower ratio of monovalent ions to multivalent ions than the pre-treated water, and directing the treated water into an irrigation water distribution system.

Abstract: Self-cleaning electrochemical cells, systems including self-cleaning electrochemical cells, and methods of operating self-cleaning electrochemical cells are disclosed. The self-cleaning electrochemical cell can include a plurality of concentric electrodes disposed in a housing, a fluid channel defined between the concentric electrodes, and an electrical connector positioned at a distal end of a concentric electrode and electrically connected to the electrode. The electrical connectors may be configured to provide a substantially even current distribution to the concentric electrode and minimize a zone of reduced velocity occurring downstream from the electrical connector. The electrical connector may be configured to cause a temperature of an electrolyte solution to increase by less than about 0.5° C. while transmitting at least 100 W of power.

Abstract: An electrochemical separation device includes a first electrode, a second electrode, a cell stack including alternating depleting compartments and concentrating compartments disposed between the first electrode and the second electrode, an inlet manifold configured to introduce a fluid to one of the depleting compartments or the concentrating compartments an outlet manifold, and one or more of a fluid flow director disposed within the inlet manifold and having a surface configured to alter a flow path of the fluid introduced into the inlet manifold and direct the fluid into the one of the depleting compartments or the concentrating compartments, and a second fluid flow director disposed within the outlet manifold and having a surface configured to alter a flow path of the fluid introduced into the outlet manifold via one of the depleting compartments or the concentrating compartments.