Membrane Bioreactor for Perchlorate Treatment

Abstract

Several methods have been employed to remove perchlorate, an endocrine disrupting anion, from water. Most of these techniques only separate perchlorate from the bulk liquid producing secondary waste, hence requiring post-treatment processes which increase the operating cost. Biological degradation, a low cost and environment-friendly method, ensures complete conversion of perchlorate to non-toxic Cl− and O2, but requires disinfection process to remove the pathogenic microorganisms before the water is reused. Conventional membrane bioreactor (MBR), particularly pressure-driven and ion exchange MBRs, addresses this constraint by integrating membrane filtration with biodegradation in a hybrid system to prevent microbial contamination of treated water while effectively degrading perchlorate. Gas-transfer MBR is different from the conventional MBR since a gaseous substrate is diffused through a gas-permeable membrane towards the bio-compartment to be used as an electron donor for the microbial reduction of perchlorate. Such configuration can be used in both in situ and ex situ treatment of contaminated sites. This chapter discusses the different types of MBR used for perchlorate treatment, limitation of the process, and some future perspectives.