Removal of perchlorate and nitrate in an ion exchange membrane bioreactor

The ion exchange membrane bioreactor (IEBM) concept is based on the use of a non-porous ion exchange membrane, acting as a barrier between water, containing one or more target inorganic charged pollutants, and a biological compartment, containing a microbial culture able to degrade (transform) these pollutants to harmless products. In this study, the IEMB process potential for treating drinking water streams, in which ClO4- may be present as a trace ion was evaluated. The results showed that ClO4- and NO3- ions could be simultaneously transported and biologically reduced. For a model polluted stream containing 100 ppb of ClO4- and 60 ppm of NO3-, the concentrations of both ions in the treated stream dropped below the recommended levels of 18 ppb for ClO4- and 25 ppm for NO3-, which corresponded to a treated water production rate of about 30 L/(m(2)h).