Disclosed is a water softening system including a first filter unit and a second filter unit that selectively performs a removal mode of discharging soft water that contains a smaller amount of an ionic material than source water or a recycling mode of discharging reclaimed water that contains a larger amount of the ionic material than the source water.

A water purification apparatus including a first water purification station for a first internal purified water stream. A valve selects either a first dispense purified water stream or a first continuing water stream or both. An internal reservoir receives the first continuing water stream to hold a volume of second purified water, and provides a second internal purified water stream. A second valve able dispenses the second dispense purified water stream. A second water purification station receives the second internal purified water and provides a third internal purified water stream. A third valve selects from the third internal purified water stream either a third dispense purified water stream, or a third continuing water stream, or both. A recirculation loop returns the third continuing water stream into the internal reservoir. A pump pumps the second internal purified water stream from the internal reservoir around the recirculation loop.

A capacitive deionization device includes, an anode and a cathode configured to oppose active materials to each other to form a passage, the anode and the cathode adsorbing ions based on electric double layers established in pores on the surfaces of the active materials; a concentration controller configured to keep the concentration of ions in liquid flowing into the passage at a level equal to or higher than a predetermined threshold; and a control circuit configured to regulate potential applied between the anode and the cathode at a level lower than an upper limit determined in accordance with the concentration of the ions detected.

The present invention discloses an SWRO and MCDI coupled seawater desalination device system with energy recovery, including a pre-filtering unit, an SWRO treatment unit, an MCDI treatment unit, and a post-filtering unit. The SWRO treatment unit is coupled with the MCDI treatment unit. Seawater desalination is performed through a coupling complementary water passage and circuit design, while water quality is improved, and the continuity of water output from a water passage of the device is kept. By recovering the pressure potential energy of high-pressure brine in the SWRO treatment unit and electric energy released by desorption in the MCDI treatment unit, energy consumption is reduced.

A method of forming an electrode for capacitive deionization includes depositing an slurry onto a substrate, wherein the slurry comprises a porous material, a first crosslinkable hydrophilic polymer, and a crosslinker for the first crosslinkable hydrophilic polymer; annealing the slurry deposited on the substrate to create a crosslinked porous layer on the substrate; depositing an solution comprising an ion-exchange material, a second crosslinkable hydrophilic polymer, and a crosslinker for the second crosslinkable hydrophilic polymer onto the crosslinked porous layer; and optionally annealing and/or drying the solution on the crosslinked porous layer.

A management method of a system for producing an ultrapure water, the system including a boron removal tower including an accommodation space through which water to be processed passes and a boron adsorption resin filling the accommodation space of the boron removal tower, and the boron removal tower including a plurality of sample ports through which a plurality of sample waters to be processed passing through portions having different heights of the boron adsorption resin, are respectively discharged, and determining a replacement cycle of the boron adsorption resin by increasing a passing flow rate of the boron removal tower.

A disclosed portable replenishable scalable electrodialysis device includes conductive members extending the cell length, with a first conductive member connected to a negative polarity current and a second conductive member connected to a positive polarity current source. Each cell includes four membranes, with a first membrane positioned adjacent a first conductive member, a second membrane positioned adjacent a second conductive member, etc. Each cell has five channels, with a first channel positioned between the first membrane and the first conductive member, the second channel positioned between the second membrane and the second conductive member, etc. The device is connected to sources of salt water, diluent water, and water with conductive material, where the water with the conductive material is flowed through a first channel and a second channel, and the salt water is flowed through a third and fourth channel and the diluent is flowed through said fifth channel.

The invention relates to a capacitive electrode comprising: an electrode housing comprising: ˜a number of housing walls that enclose a housing space; and ˜an opening that is operatively connected to the housing space, and wherein the opening is configured to be positioned adjacent an end membrane of a membrane stack; —a capacitive layer that is positioned in the housing space; —a current feeder that is positioned in the housing space and that is in electrical contact with the capacitive layer; —a gel layer that is positioned in contact with the capacitive layer; wherein the gel layer is provided in or adjacent to the opening such that the gel layer seals the opening, or wherein the gel layer is positioned near a bottom housing wall of the housing and the current feeder is positioned in or near the opening.

An electrode with a relatively high surface area is formed substantially from graphene sheets.

A device for enabling controlled movement of ions between a first ion-containing fluid and second ion-containing fluid comprises at least one cationic exchange membrane positioned between the first and second ion-containing fluids, and at least one anionic exchange membrane in parallel with the at least one cationic exchange membrane positioned between the first and second ion-containing fluids. The one or more of the at least one cationic exchange membrane and the at least one anionic exchange membrane is a membrane electrode assembly comprising an ion exchange membrane, and one or more permeable electrodes embedded within the ionic exchange membrane. The number of cationic exchange membranes and the number of anionic exchange membranes is the same, and the ions move through the membrane electrode assembly in response to a variable capacitive charge.