A desalination method that may be used to reduce limescale buildup in desalination electrodes. The desalination method includes providing an electrode including a first material having at least one compound of a formula before a desalination step. The formula is A.sub.xFe.sub.yCu.sub.z(CN).sub.6, where A is Na, Li or K, 0.1≤x≤2, 1≤y, and z≤2. The desalination method further includes exchanging A in A.sub.xFe.sub.yCu.sub.z(CN).sub.6 with Ca to form a second material from the first material during the desalination step.

An energy-efficient disinfection or sterilisation of contaminated liquid, such as water contaminated with viruses or microbes includes an asymmetric configuration of a cavitation nozzle made from dielectric material that enables the formation of a single, stable cavitation bubble of a large volume. A low-pressure gaseous plasma is continuously formed inside the cavitation bubble by electrodes to prevent contact of the metallic electrode with liquid water and Ohmic heating of the contaminated water. The electrodes are connected to a high voltage power supply. The power supply enables formation of a continuous stable gaseous discharge inside the cavitation bubble and radicals and radiation useful for destruction of viruses to the levels below the current US EPA standard in few minutes, while the temperature of liquid water remains practically unchanged. Use is not only for hospitals and pharmaceutical companies but the food industry and agriculture as well.

A portable replenishable scalable capacitive deionization device having a plurality of deionization cells, each of the cells having first and second ends, each of the cells including a cell wall, each of the cells having removable end caps covering the cell first and second ends. Each of the cells having first and second conductive members extending the length of each of the deionization cells, the first conductive member electrically connected to a first current source having negative polarity and the second conductive member electrically connected to a second current source having positive polarity. Each of the deionization cells including first, second and third membranes, the first membrane positioned adjacent the first conductive member, the second membrane positioned adjacent the second conductive member, and the third membrane is positioned between the first and second membranes wherein the first, second and third membranes are removable from each of the deionization cells.

Disclosed is an electrolytic cell having an anode and a cathode, wherein the cathode comprises a surface layer which is repellent towards inorganic material. Such repellent layer may be employed to prevent formation of scale on an electrolytic cell. Also disclosed is an apparatus for cleaning seawater that employs such electrolytic cell, . and a system for injecting cleaned seawater into a hydrocarbon reservoir, wherein the system comprises tubing, an injection pump, and the seawater cleaning apparatus employing the disclosed electrolytic cell.

Ion separation media are described herein employing thermoelectric materials and architectures. In some embodiments, an ion separation medium comprises a layer of inorganic nanoparticles having a Seebeck coefficient sufficient to transport ionic species in a liquid medium along surfaces of the layer in the presence of a thermal gradient.

An energy-efficient disinfection or sterilisation of contaminated liquid, such as water contaminated with viruses or microbes includes an asymmetric configuration of a cavitation nozzle made from dielectric material that enables the formation of a single, stable cavitation bubble of a large volume. A low-pressure gaseous plasma is continuously formed inside the cavitation bubble by electrodes to prevent contact of the metallic electrode with liquid water and Ohmic heating of the contaminated water. The electrodes are connected to a high voltage power supply. The power supply enables formation of a continuous stable gaseous discharge inside the cavitation bubble and radicals and radiation useful for destruction of viruses to the levels below the current US EPA standard in few minutes, while the temperature of liquid water remains practically unchanged. Use is not only for hospitals and pharmaceutical companies but the food industry and agriculture as well.

Provided herein are highly porous electrode structures made from natural materials and retaining natural architecture, which are highly permeable and find use in capacitive deionization desalination systems and methods. Also provided herein are methods of making the electrodes and desalination systems, as well as methods of desalinating water.

A desalination cell including an electrode including a material having at least one compound of the following formula: A.sub.xM.sup.I.sub.yM.sup.II.sub.z(CN).sub.6, where A is Na, Li or K, 0≤x≤2, M.sup.I is a first metal, M.sup.II is a second metal, 1≤y, and z≤2. The material is configured to reduce calcium carbonate formation and/or carbon dioxide gas formation during operation of the desalination cell. The first metal may be Fe, Mn, Co, Sc, Ti, Cr or Zn. The second metal is Fe, Mn, Co, Sc, Ti, Cr or Zn. The first metal may be different than the second metal.

Provided is an alkaline water electrolyzer in which leakage of aqueous alkali solutions is prevented. The alkaline water electrolyzer 10 includes an anode chamber frame 11 defining an anode chamber 12; a cathode chamber frame 17 defining a cathode chamber 18; a porous diaphragm 16 disposed between the anode and cathode chamber frames 11 and 17 and partitioning the anode and cathode chambers 12 and 18; an anode gasket 15 disposed on the anode chamber frame 11; and a cathode gasket 21 disposed on the cathode chamber frame 17, wherein when the anode and cathode chamber frames 11 and 17 are fastened, the porous diaphragm 16 is held between the anode and cathode chamber frames 11 and 17 via the anode and cathode gaskets 15 and 21 and the anode and cathode gaskets 15 and 21 are in contact with each other around the peripheral edge of the porous diaphragm 16 by compressing the anode and cathode gaskets 15 and 21.

The present invention provides a method of deionization of a liquid including passing feedwater to be deionized through a deionization fuel cell system, which includes a deionization fuel cell (DFC), containing, inter alia, a cation exchange membrane and an anion exchange membrane and discharging the DFC to produce electricity and deionized liquid, wherein the method does not include a step of charging the fuel cell prior to or following the discharge step. Further provided are deionization fuel cell systems comprising a DFC comprising two or more membranes.