AWWA WQTC58898

As a collaborative effort between MWH and the University of Houston, the two primary objectives of this research 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. While addressing these objectives, the underlying requirement of the pilot-scale system was to ensure that the treated water perchlorate concentration remained below the California Department of Public Health Services perchlorate Advisory Action Level of 4 ug/L. Designed, constructed and installed within MWH's Mobile Water Treatment Pilot Trailer, the pilot plant included two parallel ion-exchange columns (clear PVC) that could be operated independently in either co- or counter-current exhaustion and regeneration. For the purposes of this study, the columns were operated in a counter-current mode with up-flow exhaustion and down-flow regeneration. Screens were inserted at the top and bottom of each ion-exchange column to contain the resin in the column during the exhaustion and regeneration modes. The treated water was collected in a clearwell and was also used for rinse water after regeneration. The spent brine solution was either wasted or collected in a holding tank to be fed to the brine treatment system. The treated brine was then returned to the regeneration (sweet) brine tank. Includes table, figures.