AWWA ACE61613

The objectives of this study were to perform a bench scale evaluation for treating perchlorate and nitrate in ISEP spent brine. Specific objectives were to: develop salt (NaCl) tolerant cultures that can reduce perchlorate and nitrate; evaluate the capability of cultures to reduce perchlorate in spent brine produced by ISEP ion-exchange process; determine the effect of varying brine constituents on biological reduction of perchlorate and nitrate; and, perform microbial characterization of the cultures. All the experiments were conducted using spent brine from the ISEP process. Modification included: addition of 3 times the stoichiometric requirement of acetate; adjusting of Mg2+/Na+ ratio to 0.11; flushing with N2 gas for hr; and, operated as SBR (50-60% replacement) with 22 hrs reaction time and 2 hrs settling time. Information is outlined on further topics that include: analysis of spent ISEP brine; long-term brine treatment; matrix evaluation; pH effects; salt tolerance; and, nitrate and sulfate effects.