Electrodialysis pilot test using a nitrate selective electrodialysis membrane

Electrodialysis is a desalination process used to produce water for potable, industrial and chemical use. In Southern California, desalination plants are proposed to produce drinkable water. Electrodialysis (ED) and reverse osmosis (RO) are two membrane processes considered for these facilities.; The Arlington Desalter is an existing RO treatment plant in Riverside, California, that removes minerals and nitrates from brackish groundwater. Electrodialysis and RO are competing processes, though no full-scale potable water ED plants have been installed locally. Electrodialysis offers comparable water treatment with smaller concentrate discharges.; This project tested a new nitrate selective ED membrane. The ED unit was installed parallel to the Arlington Desalter RO units. Two pilot tests were performed. The first test featured a constant 78% recovery rate, while the second test incrementally increased the recovery rate to 95%. The tests showed that ED produced potable quality water consistent with RO product water, at a decreased concentrate volume.