Treatability of Perchlorate in Groundwater Using Ion Exchange Technology - Phase II

Since 1997, several perchlorate treatment technologies have proven to be technically feasible at drinking-water treatment scale: biological reduction, ion exchange, reverse osmosis (RO) membranes, and granular activated carbon (GAC). The objectives of this project were to demonstrate the long-term performance of conventional ion-exchange technology for perchlorate removal and evaluate three disparate alternatives (chemical, biological, electrolytic) for brine treatment and reuse. This project evaluated three fundamentally different brine treatment and reuse processes. The first process, the biological brine treatment system, operated as a sequencing batch reactor (SBR). The second process, the physical/chemical brine treatment system, employed a high-pressure and high-temperature catalytic process to reduce the nitrate and perchlorate in the spent brine. The last process, a simple bipolar electrochemical cell, electrolytically reduced the perchlorate and/or nitrate present in the spent ion exchange brine. Potential users of the treatment technologies developed in this research include all municipalities required to treat perchlorate- and/or nitrate-contaminated groundwater. The treatment processes evaluated in this research are applicable to both existing and future ion exchange systems, and could be applied to decontaminating high-pressure membrane reject streams as well.