title: Impact of precipitation on the treatment of real ion-exchange brine using the H(2)-based membrane biofilm reactor.
abstract: The H(2)-based membrane biofilm reactor (MBfR) was used to remove nitrate and perchlorate from real ion-exchange brine at two different salinities (30- and 50-g/L NaCl). Base production from nitrate reduction to N(2) gas caused the pH to increase, and this exacerbated precipitation of calcium and magnesium carbonates onto the MBfR fibers. The precipitates lowered the H(2) flux to the biofilm and caused a deterioration of denitrification performance that could be reversed by mild citric-acid washing. The addition of acid seems to be the only mechanism to avoid serious precipitation, membrane fouling, and non-optimal pH for denitrification.
authors.affiliation: Center for Environmental Biotechnology, Biodesign Institute at Arizona State University, Tempe, AZ 85287-5701, USA. steppen@asu.edu
authors.forename: Steven W
authors.initials: SW
authors.lastname: Van Ginkel
authors.forename: Youneng
authors.initials: Y
authors.lastname: Tang
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Rittmann
mesh_terms: D001419:Bacteria / Q000254:growth & development / Q000378:metabolism; D001673:Biodegradation, Environmental; D018441:Biofilms / Q000254:growth & development*; D019149:Bioreactors / Q000382:microbiology; D011232:Chemical Precipitation; D058440:Denitrification; D006863:Hydrogen-Ion Concentration; D007474:Ion Exchange; D008567:Membranes, Artificial; D009566:Nitrates / Q000378:metabolism*; D010084:Oxidation-Reduction; D010472:Perchlorates / Q000378:metabolism*; D054712:Salinity; D012492:Salts / Q000737:chemistry; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D008567:Membranes, Artificial; D009566:Nitrates; D010472:Perchlorates; D012492:Salts; C017082:brine; C494474:perchlorate