Impacts of Cocontaminants on the Performances of Perchlorate and Nitrate Specialty Ion-Exchange Resins

The influence of anionic inorganic cocontaminants including nitrate, Cr(VI), Se(VI), and As(V) on the application of nitrate and perchlorate specialty resins in water treatment was investigated. It was found that nitrate can be removed from waters using perchlorate specialty resins, but the resin is poorly regenerated. Perchlorate was not easily removed from either nitrate or perchlorate specialty resins. Simultaneous removal of nitrate and Cr(VI) was optimal when using nitrate specialty resin. Perchlorate/nitrate specialty resins were inefficient in removing As (V), but can exchange Cr(VI) or Se(VI). A major concern is the presence of high levels of Cr(VI), As(V), or Se(VI) in the waste brine, which affects waste brine disposal and cost. Perchlorate specialty resins showed very low run length for Cr (VI), As(V), or Se(VI). Nitrate specialty resins were very efficient in removing Cr(VI), and they can be easily regenerated.