title: Fluorescence spectroscopy for monitoring reduction of natural organic matter and halogenated furanone precursors by biofiltration.
abstract: The application of fluorescence spectroscopy to monitor natural organic matter (NOM) reduction as a function of biofiltration performance was investigated. This study was conducted at pilot-scale where a conventional media filter was compared to six biofilters employing varying enhancement strategies. Overall reductions of NOM were identified by measuring dissolved organic carbon (DOC), and UV absorbance at 254 nm, as well as characterization of organic sub-fractions by liquid chromatography-organic carbon detection (LC-OCD) and parallel factors analysis (PARAFAC) of fluorescence excitation-emission matrices (FEEM). The biofilter using granular activated carbon media, with exhausted absorptive capacity, was found to provide the highest removal of all identified PARAFAC components. A microbial or processed humic-like component was found to be most amenable to biodegradation by biofilters and removal by conventional treatment. One refractory humic-like component, detectable only by FEEM-PARAFAC, was not well removed by biofiltration or conventional treatment. All biofilters removed protein-like material to a high degree relative to conventional treatment. The formation potential of two halogenated furanones, 3-chloro-4(dichloromethyl)-2(5H)-furanone (MX) and mucochloric acid (MCA), as well as overall treated water genotoxicity are also reported. Using the organic characterization results possible halogenated furanone and genotoxicity precursors are identified. Comparison of FEEM-PARAFAC and LC-OCD results revealed polysaccharides as potential MX/MCA precursors.
authors.affiliation: Department of Civil Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario M5S 1A4, Canada. Electronic address: nicolas.peleato@mail.utoronto.ca.
authors.forename: Nicolás M
authors.initials: NM
authors.lastname: Peleato
authors.affiliation: Department of Civil Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario M5S 1A4, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: McKie
authors.affiliation: Department of Civil Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario M5S 1A4, Canada.
authors.forename: Lizbeth
authors.initials: L
authors.lastname: Taylor-Edmonds
authors.affiliation: Department of Civil Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario M5S 1A4, Canada.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Andrews
authors.affiliation: Department of Chemical Engineering, University of Waterloo, 200 University Avenue W, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Raymond L
authors.initials: RL
authors.lastname: Legge
authors.affiliation: Department of Civil Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario M5S 1A4, Canada.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Andrews
mesh_terms: D001673:Biodegradation, Environmental; D004784:Environmental Monitoring / Q000379:methods*; D005163:Factor Analysis, Statistical; D005374:Filtration; D005663:Furans / Q000032:analysis*; D054879:Halogenation; D006812:Humic Substances / Q000032:analysis*; D010865:Pilot Projects; D013050:Spectrometry, Fluorescence / Q000379:methods; D018508:Water Purification
chemical_list: D005663:Furans; D006812:Humic Substances
keywords: Biofiltration; Disinfection by-products; Fluorescence spectroscopy; Genotoxicity; Halogenated furanones; Natural organic matter