A method of chemical extraction and power generator cooling includes receiving an aqueous solution with dissolved inorganic carbon. The method further includes extracting the dissolved inorganic carbon from the aqueous solution and collecting the dissolved inorganic carbon. The aqueous solution is then acidified and supplied to the power generator to cool the power generator.

Provided are a system and a method of treating wastewater. The system includes a wastewater chamber, positive and negative electrode chambers, acid and basic solution chambers and a buffer chamber. The wastewater chamber receives wastewater containing a first ion. The positive and the negative electrode chambers are respectively on opposite sides of the wastewater chamber. The acid chamber is between the wastewater chamber and the positive electrode chamber. The basic chamber is between the wastewater chamber and the negative electrode chamber. The buffer chamber is between one of the acid and the basic chambers and the wastewater chamber, and receives the buffer solution containing the first ion. The interfaces between the wastewater chamber and the buffer chamber and between the one of the acid and the basic chambers and the buffer chamber are ion exchange membranes having the same electrical properties.

A system for treatment of a brine feed, the system including a hybrid reactor, the reactor having a plurality of forward osmosis membranes configured to permit the passage of a draw solution solute through the middle of the membrane to draw water across the membrane wall from the brine feed so as to generate diluted solute, and a plurality of membrane electrode assemblies configured to separate ions of the salt in the brine feed to concentrate the salt ions, each membrane electrode assembly having an anion exchange membrane and a cation exchange membrane; whereby each membrane electrode assembly houses a plurality of forward osmosis membranes therewithin.

A membrane having permselectivity for perchlorate ion is prepared using certain types of quaternary ammonium salts contained in a polymeric matrix material, which may be plasticized. Such membranes are useful in electrodialysis processes, whereby perchlorate-contaminated aqueous compositions are purified.

A membrane having permselectivity for perchlorate ion is prepared using certain types of quaternary ammonium salts contained in a polymeric matrix material, which may be plasticized. Such membranes are useful in electrodialysis processes, whereby perchlorate-contaminated aqueous compositions are purified.

Provided are a curable composition including a compound expressed by General Formula (1) below; a polymerization initiator; and a chain transfer agent, and a cured polymer product. ##STR00001##
In General Formula (1), m represents an integer of 1 to 4, and n represents an integer of 1 to 4. Here, a sum of m and n is not greater than 5. M.sup.A represents a hydrogen ion, an inorganic ion, or an organic ion. Here, an inorganic ion and an organic ion may be bivalent or higher ions. Each of R.sup.1 and R.sup.2 independently represents a hydrogen atom or an alkyl group.

A process for ion-exchanging an exchangeable-ion containing solid material involves several steps. There is a bipolar membrane electrodialysis step, which involves subjecting an aqueous ion-containing solution to a bipolar membrane electrodialysis to produce an acid liquid. The process also contains an ion-exchange step, during which the exchangeable-ion containing solid material is contacted with the acid liquid to conduct ion-exchange to produce a slurry containing the ion-exchanged solid material. It further include a solid-liquid separation step, during which the slurry containing the ion-exchanged solid material is subject to a solid-liquid separation to produce a solid phase and a liquid phase. The pH value of the liquid phase is adjusted to 4-6.5. The pH-adjusted liquid phase is further subject to a solid-liquid separation to produce a treatment liquid.

Methods and circuits for a device for interrupting concentration-related polarisation phenomenon and for self-cleaning of electromembrane processes by application of asymmetric inverse-polarity pulses with high intensity and variable frequency are described. The device, a bipolar switch, is based on the use of solid-state electronics to carry out polarity inversion in a range of frequencies, intensities and pulse widths to prevent or reduce formation of precipitates on the surfaces of the membranes. The inversion protocol, with a frequency that varies as a function of the appearance of dirt on the membranes, as measured by the decrease in voltage or electrical resistance of the membrane cell during electromembrane processes, is also provided. This device and configuration provides application of modulated and stable high-intensity pulses using a second power source. Electromembrane processes can be updated by replacing electrodes, suitable for polarity inversion, and adding a second power source and the bipolar switch described.

Methods and circuits for a device for interrupting concentration-related polarisation phenomenon and for self-cleaning of electromembrane processes by application of asymmetric inverse-polarity pulses with high intensity and variable frequency are described. The device, a bipolar switch, is based on the use of solid-state electronics to carry out polarity inversion in a range of frequencies, intensities and pulse widths to prevent or reduce formation of precipitates on the surfaces of the membranes. The inversion protocol, with a frequency that varies as a function of the appearance of dirt on the membranes, as measured by the decrease in voltage or electrical resistance of the membrane cell during electromembrane processes, is also provided. This device and configuration provides application of modulated and stable high-intensity pulses using a second power source. Electromembrane processes can be updated by replacing electrodes, suitable for polarity inversion, and adding a second power source and the bipolar switch described.

Methods, systems and compositions for recovery of regenerant ions from spent regenerant solution by utilization of electrodialysis are provided. For example, in certain aspects methods for separating spent regenerant using an electrodialysis system comprising selective membranes are described. Furthermore, the invention provides methods for treating a friable solid ion-removal material to prevent fragmentation during regeneration.