Provided are hybrid electrochemical and membrane-based systems for removing silica from water stream to achieve ultra-pure water. The silica concentration of a feed water stream may dictate the most effective and economical variation of disclosed hybrid processes to use. For example, for a feed water stream having a silica concentration of 1-30 ppm, a hybrid system for treating the feed water includes an electrodialysis reversal unit, the electrodialysis reversal unit comprising an inlet stream and a product outlet stream; a reverse osmosis unit, the reverse osmosis unit comprising an inlet stream and a product outlet stream, wherein the inlet stream of the reverse osmosis unit comprises the product outlet stream of the electrodialysis reversal unit; and an electrodeionization unit, the electrodeionization unit comprising an inlet stream and a product outlet stream, wherein the inlet stream of the electrodeionization unit comprises the product outlet stream of the reverse osmosis unit.

Various examples related to resin wafer technologies including ionomers and resin wafers with solution processable ionomers and their production are provided. In one example, a wafer includes an ion conducting layer having ion-exchange resin particles and an ionomer binder coating the ion-exchange resin particles. The ionomer binder can bind the ion-exchange resin particles together in the ion conducting layer. In another example, the wafer can contain water dissociation catalysts for promoting water-splitting in the wafers.

A quaternary ammonium group-grafted cation resin and a preparation method thereof are provided. The preparation method includes: adding a chloromethylated cross-linked polystyrene (PS) resin, trimethylamine hydrochloride, and a 20% sodium hydroxide aqueous solution successively to a reactor for a reaction under stirring at 30° C. to 40° C.; filtering a resulting reaction solution, followed by washing and drying to obtain a quaternary ammonium group-grafted resin; adding the quaternary ammonium group-grafted resin, 1,2-dichloroethane, silver sulfate, concentrated sulfuric acid, and fuming sulfuric acid successively for a reaction for 1 hour at 50° C. to 60° C., a reaction for 1 hour at 70° C. to 80° C., and a reaction for 5 hours at 115° C. to 125° C.; and cooling a resulting reaction solution to room temperature, followed by diluting, filtering, washing and drying to obtain the quaternary ammonium group-grafted cation resin.

A switching system of an EDR water purifier has a first inlet end, a second inlet end, a first three-way solenoid valve, a second three-way solenoid valve, a third three-way solenoid valve, a fourth three-way solenoid valve, an EDR membrane stack, a first outlet end, and a second outlet end. The EDR membrane stack has a first inlet port, a second inlet port, a first outlet port, a second outlet port, a first electrode, and a second electrode. Each three-way solenoid valve has an inlet opening, a first outlet opening, and a second outlet opening. Each outlet opening of each three-way solenoid valve can be turned open or closed for switching two water routes passing the EDR membrane stack. Therefore, speed of forming limescale decreases, lifespan of the EDR membrane stack is prolonged, and water-purifying efficiency is improved.

A switching system has two inlet ends, two outlet ends, and an EDR membrane stack. Each inlet end and each outlet end are connected to both a primary branch and a secondary branch. Solenoid valves are mounted on each primary branch and each secondary branch to switch between opening and closing. The EDR membrane stack has two inlets, two outlets, and two electrodes. One inlet is connected to the primary branch of the two inlet ends while the other is connected to the secondary branch of the two inlet ends. One outlet is connected to the primary branch of the two outlet ends while the other is connected to the secondary branch of the two outlet ends. The polarity of the two electrodes is interchangeable to realize the reverse polarity of the electrodes. The two water flows that pass through the EDR membrane stack are interchangeable.

A switching system for an EDR water purifier has a first raw-water inlet end, a second raw-water inlet end, two four-way solenoid valves, an EDR membrane stack, a freshwater outlet end, and a wastewater outlet end. Each four-way solenoid valve has a first inlet end, a second inlet end, a first outlet end, and a second outlet end. The first inlet end of each four-way solenoid valve can communicate with one of the first outlet end and the second outlet end of the same four-way solenoid valve, and the second inlet end of the same four-way solenoid valve can communicate with the other one of the first outlet end and the second outlet end, to execute water-route switching. By switching two water routes passing through the EDR membrane stack, forming of limescale is alleviated, lifespan of the EDR membrane stack is extended, and water-purifying efficiency is improved.

The disclosure relates to systems, devices, and methods for flow control in a reverse osmosis filtration system, such as within a medical device. The systems, devices, and methods can respond to changes in permeate flow rate and solute concentration by adjusting feed water and concentrate water rates. Multiple feedback loops adjust parameters to meet water flow rate and purity requirements.

Disclosed are wastewater treatment systems and methods for semiconductor fabrication process. The method comprises performing first concentration on wastewater discharged from a semiconductor process chamber, and performing second concentration on concentrated wastewater or at least a portion of the wastewater concentrated by the first concentration. The step of performing the first concentration includes performing in a first electrodialysis apparatus an ion exchange between the wastewater and first treatment water. The step of performing the second concentration includes allowing the concentrated wastewater to circulate in a second electrodialysis apparatus, allowing second treatment water to circulate in the second electrodialysis apparatus, providing a power to an anode and a cathode of the second electrodialysis apparatus to perform an ion exchange between the second treatment water and the concentrated wastewater, and joining a portion of the concentrated wastewater to the second treatment water.

The present disclosure is directed to an electrodialytic stack with a concentrate stream that moves through a concentrate flow path bounded by a central ion exchange membrane and a first outer ion exchange membrane. A dilute stream moves through a dilute flow path bounded by the central ion exchange membrane and a second outer ion exchange membrane. A redox shuttle loop is separated from the concentrate and dilute streams by the first and second outer ion exchange membranes, respectively. The outer ion exchange membranes are a different type than the central ion exchange membrane. Electrodes are operable to apply a voltage across the stack. At least one collection of ion exchange materials is located in at least one of the flow paths. The ion exchange materials migrate ions between the central ion exchange membrane and at least one of the outer ion exchange membranes.

A water-softening system includes a filter device including filter units that are provided in at least some of a plurality of supply channels arranged in parallel to supply raw water to a consumption site and that remove at least part of ionic matter contained in supplied raw water by electro-deionization and discharge soft water containing less ionic matter than the raw water, a plurality of supply valves provided in the plurality of supply channels to open or close the supply channels, and a processor connected to the filter device and the plurality of supply valves. The processor determines whether water is supplied to the consumption site and controls at least one of the plurality of supply valves to remain open to maintain a state in which water is allowed to be supplied to the consumption site, when it is determined that no water is supplied to the consumption site.