Using electricity to remove impurities from water

Electrodialysis (ED) and Electrodialysis Reversal (EDR)

Brackish water desalination became viable in the early 1950's when GE Water & Process Technologies developed the world's first commercially-applied membrane desalination technology. This breakthrough, called electrodialysis (ED), is an electrochemical separation process in which ions are transferred through ion exchange membranes by means of direct current (DC) voltage. In the ED process, ions are removed from the feed water as the current drives the ions through the membranes to desalinate the process stream. In the early 1970's, ED was updated to electrodialysis reversal (EDR), which provided reversal of the electric field and automatic membrane cleaning. Today, EDR is widely used to economically treat water supplies which are challenging for other technologies to process and where water recovery up to 95% is required.

The ability to remove minerals and salts provides a solution to convert previously unusable waters to high purity resources for drinking water or high purity industrial uses.

Electrodeionization (EDI)

Electrodeionization (EDI) is a mature electrically driven membrane demineralization process used to refine industrial process water to ultra-high purity for use in the power, microelectronics, food, chemical, pharmaceutical, and other industries. GE's EDI systems utilize high-capacity ion exchange membranes to remove not only residual salts but also ionizable aqueous species such as carbon dioxide, silica, ammonia and boron. EDI has an advantage over more traditional ion-exchange processes in that it eliminates the need for the frequently expensive and hazardous chemicals used in the ion exchange resin regeneration process.