title: Performance of biological magnetic powdered activated carbon for drinking water purification.
abstract: Combining the high adsorption capacity of powdered activated carbon (PAC) with magnetic properties of iron oxide nanoparticles (NPs) leads to a promising composite material, magnetic PAC or MPAC, which can be separated from water using magnetic separators. We propose MPAC as an alternative adsorbent in the biological hybrid membrane process and demonstrate that PAC covered with magnetic NPs is suitable as growth support for heterotrophic and nitrifying bacteria. MPAC with mass fractions of 0; 23; 38 and 54% maghemite was colonized in small bioreactors for over 90 days. Although the bacterial community composition (16s rRNA analysis) was different on MPAC compared to PAC, NPs neither inhibited dissolved organic carbon and ammonia biological removals nor contributed to significant adsorption of these compounds. The same amount of active heterotrophic biomass (48 μg C/cm(3)) developed on MPAC with a mass fraction of 54% NPs as on the non-magnetic PAC control. While X-ray diffraction confirmed that size and type of iron oxides did not change over the study period, a loss in magnetization between 10% and 34% was recorded.
authors.affiliation: NSERC Industrial Chair on Drinking Water, Department of Civil, Geological and Mining Engineering, Polytechnique Montreal, P.O. Box 6079, Downtown Station, Montréal, QC H3C 3A7, Canada. Electronic address: kim-maren.lompe@polymtl.ca.
authors.forename: Kim Maren
authors.initials: KM
authors.lastname: Lompe
authors.affiliation: Department of Engineering Physics, Polytechnique Montreal, Montréal, Qc, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Menard
authors.affiliation: NSERC Industrial Chair on Drinking Water, Department of Civil, Geological and Mining Engineering, Polytechnique Montreal, P.O. Box 6079, Downtown Station, Montréal, QC H3C 3A7, Canada.
authors.forename: Benoit
authors.initials: B
authors.lastname: Barbeau
mesh_terms: D000327:Adsorption; D019149:Bioreactors; D002244:Carbon; D002606:Charcoal; D012336:RNA, Ribosomal, 16S; D018508:Water Purification
chemical_list: D012336:RNA, Ribosomal, 16S; D002606:Charcoal; D002244:Carbon
keywords: Biological treatment; Heterotrophic biomass; Hybrid membrane process; Iron oxide nanoparticles; Magnetic powdered activated carbon