Electrodialysis reversal (EDR) and ion exchange as polishing treatment forperchlorate treatment

Due to the development of a new analytical method that lowered the perchlor ate detection limit to 4 mug/L, perchlorate has been detected in many drink ing water sources. Perchlorate contamination is now recognized as a widespr ead concern affecting many water utilities. Furthermore, perchlorate is a v ery stable substance in aquatic systems and is therefore difficult to remov e with conventional treatment processes. Magna Water Company in Utah, USA, provides chlorinated groundwater as potable water to the northwest section of Salt Lake County. The groundwater of one of their wells is contaminated with low levels of perchlorate and concentrations are expected to rise due to plume migration. High hardness, alkalinity, and TDS characterize this gr oundwater. An electrodialysis reversal (EDR) pilot unit was installed at an uncontaminated well. Various perchlorate levels were spiked into the feed water to test the full range of possible perchlorate concentrations. This p aper provides EDR performance and cost data for perchlorate treatment. Base d on perchlorate removal, the production cost varies between $1.10 and $1.5 0 per 1000 gal ($0.30 and $0.40/m(3)). The presented data allow comparison with other treatment processes.