Evaluation for Biological Reduction of Nitrate and Perchlorate in Brine Water Using the Hydrogen-Based Membrane Biofilm Reactor

Jinwook Chung, Robert Nerenberg, Bruce E. Rittmann
2007 Journal of environmental engineering  
Whereas ion exchange is an attractive technology for treating perchlorate and nitrate in drinking water, a major disadvantage is that the resin must be regenerated using a brine, producing wastes with high concentrations of nitrate, perchlorate, and salt. This study investigates the potential for simultaneous nitrate and perchlorate reductions in high-salt conditions using the H 2 -based membrane biofilm reactor ͑MBfR͒. The autotrophic biological reductions produce harmless N 2 and Cl − ,
more » ... 2 and Cl − , making the brine safe for reuse or disposal. A very high-strength brine ͑ϳ15% salt͒ from a commercial ion-exchange membrane, Purolite, supported biofilm accumulation and allowed slow reduction rates for nitrate and perchlorate. Reduction rates increased significantly when the Purolite brine was diluted by 50% or more. A synthetic high-strength salt medium containing nitrate, perchlorate, or both supported more rapid reduction rates for as high as 20 g / L ͑ϳ2%͒ NaCl, while 40 g / L NaCl slowed reduction by 40% or more, confirming that the microorganisms in the MBfR were inhibited by high salt content. An increase of H 2 pressure gave higher fluxes for 20 g / L NaCl, demonstrating that H 2 availability controlled the reduction kinetics when the system was not salt-inhibited.
doi:10.1061/(asce)0733-9372(2007)133:2(157) fatcat:2g7s27ezdzgi7ablbqj4of7idq