Learn the basics of electrodialysis and reverse osmosis systems.
Electrodialysis uses an electrical potential to move salts selectively through a membrane, leaving fresh water behind as product water. In the RO process, pressure is used for separation by allowing fresh water to move through a membrane, leaving the salts behind. Both of these concepts have been explored by scientists since the turn of the century, but their commercialization for desalting water for municipal purposes has occurred only in the last 30 years.