Abstract:
Systems and methods for the desalination of seawater or brackish water for the purpose of obtaining potable water. Systems may include a combination of electrodialysis and electrodeionization modules. The system configuration and process controls may achieve low energy consumption and stable operation.
Abstract:
A reverse electrodialyzer has a plurality of concentrated compartments and diluted compartments arranged alternatively. The concentrated compartments and the diluted compartments are formed by successive alternatively arranged oppositely charged ion exchange membranes between two electrodes. A brine solution is fed into the concentrated compartments, and a diluted solution is into the diluted compartments, the salinity of the diluted solution being lower than the salinity of the brine solution. Ions from the brine solution in the concentrated compartments pass through the membranes to the diluted solution in the diluted compartments forming a diluted brine solution in the concentrated compartments. The brine solution is extracted from the concentrated compartments for disposal. An electrical energy is produced due to the concentration difference of the brine solution and the diluted solution.
Abstract:
Electrochemical separation devices are configured for lower energy consumption. Techniques for reducing shadow effect may involve providing distance between a spacer screen and an adjacent ion-selective membrane. A spacer having a screen that is thin relative to a surrounding frame may be used. Mild pressure may also be applied to a compartment to promote distance between a spacer screen and an adjacent ion-selective membrane.
Abstract:
Reverse electrodialysis (RED) may be used to neutralize acid and caustic effluent waste streams, such as in the semiconductor industry. Power may be generated while waste streams are treated by converting chemical energy into electric energy. A bipolar membrane may be integrated into the RED system. Alternatively, an anion exchange membrane and a cation exchange membrane may be overlapped and used in place of a bipolar membrane. A cell pair with four membranes and four chambers, without a bipolar membrane, may also be implemented.