title: Bio-physicochemical effects of gamma irradiation treatment for naphthenic acids in oil sands fluid fine tailings.
abstract: Naphthenic acids (NAs) are persistent compounds that are components of most petroleum, including those found in the Athabasca oil sands. Their presence in freshly processed tailings is of significant environmental concern due to their toxicity to aquatic organisms. Gamma irradiation (GI) was used to reduce the toxicity and concentration of NAs in oil sands process water (OSPW) and fluid fine tailings (FFT). This investigation systematically studied the impact of GI on the biogeochemical development and progressive reduction of toxicity using laboratory incubations of fresh and aged tailings under anoxic and oxic conditions. GI reduced NA concentrations in OSPW by up to 97% in OSPW and in FFT by 85%. The GI-treated FFT exhibited increased rates of biogeochemical change, dependent on the age of the tailings source. Dissolved oxygen (DO) flux was enhanced in GI-treated FFT from fresh and aged source materials, whereas hydrogen sulfide (HS(-)) flux was stimulated only in the fresh FFT. Acute toxicity to Vibrio fischeri was immediately reduced following GI treatment of fresh OSPW. GI treatment followed by 4-week incubation reduced toxicity of aged OSPW to V. fischeri.
authors.affiliation: Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada.
authors.forename: Ryan
authors.initials: R
authors.lastname: Boudens
authors.affiliation: Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada.
authors.forename: Thomas
authors.initials: T
authors.lastname: Reid
authors.affiliation: Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada.
authors.forename: Danielle
authors.initials: D
authors.lastname: VanMensel
authors.affiliation: Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada.
authors.forename: Sabari
authors.initials: S
authors.lastname: Prakasan M R
authors.affiliation: Biological Sciences, University of Windsor, Windsor, ON, Canada.
authors.forename: Jan J H
authors.initials: JJH
authors.lastname: Ciborowski
authors.affiliation: Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada. Electronic address: weisener@uwindsor.ca.
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Weisener
mesh_terms: D002264:Carboxylic Acids / Q000032:analysis*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005720:Gamma Rays; D061329:Oil and Gas Fields; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D002264:Carboxylic Acids; D014874:Water Pollutants, Chemical; C046170:naphthenic acid
keywords: Gamma irradiation treatment; Microbial respiration rates; Naphthenic acids; Oil industry pollution; Oil sands process water; Toxicity