title: Comparison of UV/hydrogen peroxide, potassium ferrate(VI), and ozone in oxidizing the organic fraction of oil sands process-affected water (OSPW).
abstract: The efficiency of three different oxidation processes, UV/H2O2 oxidation, ferrate(VI) oxidation, and ozonation with and without hydroxyl radical (OH) scavenger tert-butyl alcohol (TBA) on the removal of organic compounds from oil sands process-affected water (OSPW) was investigated and compared. The removal of aromatics and naphthenic acids (NAs) was explored by synchronous fluorescence spectra (SFS), ion mobility spectra (IMS), proton and carbon nuclear magnetic resonance ((1)H and (13)C NMR), and ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC TOF-MS). UV/H2O2 oxidation occurred through radical reaction and photolysis, transforming one-ring, two-ring, and three-ring fluorescing aromatics simultaneously and achieving 42.4% of classical NAs removal at 2.0 mM H2O2 and 950 mJ/cm(2) UV dose provided with medium pressure mercury lamp. Ferrate(VI) oxidation exhibited high selectivity, preferentially removing two-ring and three-ring fluorescing aromatics, sulfur-containing NAs (NAs + S), and NAs with high carbon and high hydrogen deficiency. At 2.0 mM Fe(VI), 46.7% of classical NAs was removed. Ozonation achieved almost complete removal of fluorescing aromatics, NAs + S, and classical NAs (NAs with two oxygen atoms) at the dose of 2.0 mM O3. Both molecular ozone reaction and OH reaction were important pathways in transforming the organics in OSPW as supported by ozonation performance with and without TBA. (1)H NMR analyses further confirmed the removal of aromatics and NAs both qualitatively and quantitatively. All the three oxidation processes reduced the acute toxicity towards Vibrio fischeri and on goldfish primary kidney macrophages (PKMs), with ozonation being the most efficient.
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada.
authors.forename: Chengjin
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada.
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Klamerth
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada.
authors.forename: Selamawit Ashagre
authors.initials: SA
authors.lastname: Messele
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada; Department of Biological Sciences, University of Alberta, 11455 Saskatchewan Drive, Edmonton, Alberta, T6G 2W2, Canada.
authors.forename: Arvinder
authors.initials: A
authors.lastname: Singh
authors.affiliation: Department of Biological Sciences, University of Alberta, 11455 Saskatchewan Drive, Edmonton, Alberta, T6G 2W2, Canada.
authors.forename: Miodrag
authors.initials: M
authors.lastname: Belosevic
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada. Electronic address: mgamalel-din@ualberta.ca.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Gamal El-Din
mesh_terms: D048908:Aliivibrio fischeri / Q000378:metabolism; D002264:Carboxylic Acids / Q000737:chemistry; D006861:Hydrogen Peroxide; D061329:Oil and Gas Fields; D010126:Ozone / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D002264:Carboxylic Acids; D014874:Water Pollutants, Chemical; D010126:Ozone; D006861:Hydrogen Peroxide
keywords: Ferrate(VI); Naphthenic acid; Oil sands process-affected water; Ozone; Toxicity; UV/Hydrogen peroxide