Electrodialysis reversal

Water desalination
Methods

Electrodialysis reversal (EDR) is an electrodialysis reversal water desalination membrane process that has been commercially used since the early 1960s.[1] An electric current migrates dissolved salt ions, including fluorides, nitrates and sulfates, through an electrodialysis stack consisting of alternating layers of cationic and anionic ion exchange membranes. Periodically, the direction of ion flow is reversed by reversing the polarity of the applied electric current.[1]

Advanced electrodialysis units can hybridize with reverse osmosis (RO) systems.[2] In an EDR-RO hybrid, the EDR unit functions as a chemical-free softener prior to RO treatment. The RO brine is then sent back into the advanced EDR unit for simultaneous concentration. As such, EDR is used to both pre-treat the RO feed and concentrate the RO brine. This hybrid configuration maximizes the efficiency of both technologies and produces a high concentration brine, greatly increasing recoveries. EDR-RO Hybrids are used in brine management applications; reducing brine disposal liabilities and costs.

See also

References

  1. 1 2 Katz, William E. (January 1979). "The electrodialysis reversal (EDR) process". Desalination 28 (1): 31–40. doi:10.1016/S0011-9164(00)88124-2. Retrieved 2015.
  2. ↑ Frank, Mitchell. "EDR-RO Hybrid Case Study: High Recovery Brackish Water Treatment" (PDF). EDR-RO Hybrid Case Study: High Recovery Brackish Water Treatment. Saltworks Technologies Inc. Retrieved 2015.

External links

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