Treatment of Perchlorate‐Contaminated Groundwater Using Highly Selective, Regenerable Ion‐Exchange Technology: A Pilot‐Scale Demonstration

Treatment of perchlorate‐contaminated groundwater using highly selective, regenerable ion‐exchangetechnology has been recently demonstrated at Edwards Air Force Base, California. At an influent concentration ofabout 450 μg/l ClO 4 − , the bifunctional anion‐exchange resin bed treatedapproximately 40,000 empty bed volumes of groundwater before a significant breakthrough ofClO 4 − occurred. The presence of relatively high concentrations of chloride and sulfatein site groundwater did not appear to affect the ability of the bifunctional resin to removeClO 4 − . The spent resin bed was successfully regenerated using theFeCl 3 − HCl regeneration technique recently developed at the Oak Ridge NationalLaboratory, and nearly 100 percent of sorbed ClO 4 − was displaced or recovered afterelution with as little as about two bed volumes of the regenerant solution. In addition, a new methodology wasdeveloped to completely destroy ClO 4 − in the FeCl 3 − HClsolution so that the disposal of perchlorate‐containing hazardous wastes could be eliminated. It istherefore anticipated that these treatment and regeneration technologies may offer an efficient andcost‐effective means to remove ClO 4 − from contaminated groundwater withsignificantly reduced generation of waste requiring disposal. © 2002 Wiley Periodicals, Inc.