title: Investigation of ozone and peroxone impacts on natural organic matter character and biofiltration performance using fluorescence spectroscopy.
abstract: Impacts of ozonation alone as well as an advanced oxidation process of ozone plus hydrogen peroxide (H2O2+ O3) on organic matter prior to and following biofiltration were studied at pilot-scale. Three biofilters were operated in parallel to assess the effects of varying pre-treatment types and dosages. Conventionally treated water (coagulation/flocculation/sedimentation) was fed to one control biofilter, while the remaining two received water with varying applied doses of O3or H2O2+ O3. Changes in organic matter were characterized using parallel factors analysis (PARAFAC) and fluorescence peak shifts. Intensities of all PARAFAC components were reduced by pre-oxidation, however, individual humic-like components were observed to be impacted to varying degrees upon exposure to O3or H2O2+ O3. While the control biofilter uniformly reduced fluorescence of all PARAFAC components, three of the humic-like components were produced by biofiltration only when pre-oxidation was applied. A fluorescence red shift, which occurred with the application of O3or H2O2+ O3, was attributed to a relative increase in carbonyl-containing components based on previously reported results. A subsequent blue shift in fluorescence caused by biofiltration which received pre-oxidized water indicated that biological treatment readily utilized organics produced by pre-oxidation. The results provide an understanding as to the impacts of organic matter character and pre-oxidation on biofiltration efficiency for organic matter removal.
authors.affiliation: Department of Civil Engineering, University of Toronto, Toronto, 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, Toronto, M5S 1A4, Canada.
authors.forename: Balsher Singh
authors.initials: BS
authors.lastname: Sidhu
authors.affiliation: Department of Chemical Engineering, University of Waterloo, Waterloo, N2L 3G1, Canada.
authors.forename: Raymond L
authors.initials: RL
authors.lastname: Legge
authors.affiliation: Department of Civil Engineering, University of Toronto, Toronto, M5S 1A4, Canada.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Andrews
mesh_terms: D005374:Filtration / Q000379:methods; D006812:Humic Substances; D006861:Hydrogen Peroxide / Q000737:chemistry*; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D006812:Humic Substances; D014874:Water Pollutants, Chemical; D010126:Ozone; D006861:Hydrogen Peroxide
keywords: Advanced oxidation processes; Biofiltration; Drinking water treatment; Fluorescence spectroscopy; Natural organic matter; Ozonation