An electrochemical sensor with an ion-selective membrane that comprises a crosslinked alkyl methacrylate homopolymer or copolymer of two or more alkyl methacrylates 1. with a covalently attached electrically neutral or electrically charged ionophore that is selective for a target cation or anion, or 2. with a covalently attached cationic or anionic ionic site, or 3. with a covalently attached cationic or anionic ionic site and covalently attached electrically neutral or electrically charged ionophore.

Electrodeionization and electrodialysis systems which eliminate or substantially prevent the feed water from entering the concentrating compartments, for improving the recovery of product water as well as improving the current efficiency. Electro-osmotically generated flows of water entering from the diluting compartments of the stack constitutes the majority of concentrate feed, leading to the production of high purity, desalinated waters in the diluting compartments and highly concentrate solutions in the concentrate compartments.

The present disclosure is directed to ion-exchange systems and devices that can monitor key parameters related to the performance of the ion-exchange device. Specifically, the ion-exchange systems and devices disclosed herein can provide real time voltage drop across groups of membrane pairs using diagnostic spacer borders between the pairs. In addition, the ion-exchange systems and devices disclosed herein can monitor the compression force applied by the compression plates holding the ion-exchange systems and devices together.

A resin-wafer electrodeionization (RW-EDI) apparatus for purifying water for coffee brewing comprises a cathode; an anode; and multiple porous solid resin wafer exchange units arranged in a stack between the cathode and the anode, and an air distributor adapted and arranged to aerate the water to be purified. Each unit comprises a monovalent cation exchange membrane (CEM), an anion exchange membrane (AEM), and an ion exchange resin wafer between the CEM and the AEM, which is in contact with, and in fluid flow connection with the CEM and AEM. Each resin wafer comprises a cation exchange resin and an anion exchange resin. The units are oriented with the CEM facing the cathode and the AEM facing the anode, with space between the units defining ion concentrate chambers. Bipolar ion exchange membranes separate the anode and cathode from their nearest resin wafer exchange units.

A resin-wafer electrodeionization (RW-EDI) apparatus for purifying water for coffee brewing comprises a cathode; an anode; and multiple porous solid resin wafer exchange units arranged in a stack between the cathode and the anode, and an air distributor adapted and arranged to aerate the water to be purified. Each unit comprises a monovalent cation exchange membrane (CEM), an anion exchange membrane (AEM), and an ion exchange resin wafer between the CEM and the AEM, which is in contact with, and in fluid flow connection with the CEM and AEM. Each resin wafer comprises a cation exchange resin and an anion exchange resin. The units are oriented with the CEM facing the cathode and the AEM facing the anode, with space between the units defining ion concentrate chambers. Bipolar ion exchange membranes separate the anode and cathode from their nearest resin wafer exchange units.

An electrodialysis apparatus comprises a first reservoir wherein salt dissolved in solvent is reduced below a threshold concentration and a second reservoir wherein the salt concentration increases. A first electrode contacts a first solution of a first redox-active electrolyte material, and a second electrode contacts a second solution of a second redox-active electrolyte material. A first type of membrane is disposed between the first and second reservoirs and a second type of membrane is disposed between the first electrode and the first reservoir and between the second electrode and the second reservoir. A color measuring device is coupled to at least one of the solutions, and a control system is configured to modify the value of a property of at least one of the first and second solutions in response to detecting a color value of one of the solutions exceeding a threshold color value.

An electrodialysis apparatus comprises a first reservoir wherein salt dissolved in solvent is reduced below a threshold concentration and a second reservoir wherein the salt concentration increases. A first electrode contacts a first solution of a first redox-active electrolyte material, and a second electrode contacts a second solution of a second redox-active electrolyte material. A first type of membrane is disposed between the first and second reservoirs and a second type of membrane is disposed between the first electrode and the first reservoir and between the second electrode and the second reservoir. A color measuring device is coupled to at least one of the solutions, and a control system is configured to modify the value of a property of at least one of the first and second solutions in response to detecting a color value of one of the solutions exceeding a threshold color value.

A water treatment system includes: EDI having deionization chamber that deionizes water that contains boron and concentration chambers in which concentrated water flows; and a cooler to cool the water supplied to deionization chamber or the concentrated water supplied to concentration chambers. Alternatively, water treatment system includes EDI having deionization chamber that deionizes water that contains boron, concentration chambers in which concentrated water flows, and electrode chambers in which electrode water flows; a cooler that adjusts temperature of the water or temperature of the concentrated water supplied to concentration chamber; and a controller that controls the cooler such that the cooler adjusts the temperature of the water supplied to deionization chamber or the temperature of the concentrated water supplied to the concentration chambers within a range of 10-23° C., based on the temperature of the water, temperature of treated water of EDI, the temperature of the concentrated water, or temperature of the electrode water.

A water treatment system includes: EDI having deionization chamber that deionizes water that contains boron and concentration chambers in which concentrated water flows; and a cooler to cool the water supplied to deionization chamber or the concentrated water supplied to concentration chambers. Alternatively, water treatment system includes EDI having deionization chamber that deionizes water that contains boron, concentration chambers in which concentrated water flows, and electrode chambers in which electrode water flows; a cooler that adjusts temperature of the water or temperature of the concentrated water supplied to concentration chamber; and a controller that controls the cooler such that the cooler adjusts the temperature of the water supplied to deionization chamber or the temperature of the concentrated water supplied to the concentration chambers within a range of 10-23° C., based on the temperature of the water, temperature of treated water of EDI, the temperature of the concentrated water, or temperature of the electrode water.

Systems and methods for treating water may involve a first electrochemical separation module that includes at least one ion exchange membrane having a first set of performance characteristics, and a second electrochemical separation module that includes at least one ion exchange membrane having a second set of performance characteristics that is different than the first set of performance characteristics. Performance characteristics may relate to at least one of water loss, electrical resistance, and permselectivity. Staged treatment systems and methods may provide improved efficiency.