Abstract
Naphthenic acids are toxic and corrosive substances in oil sands leachates comprising a group of saturated aliphatic and alicyclic carboxylic acids in hydrocarbon deposits (petroleum, oil sands bitumen, and crude oils). In the current study, photolysis was applied to naphthenic acid mixtures and individual compounds to determine the efficacy of a variety of UV/vis radiation sources for reducing both concentration and aryl hydrocarbon (Ah) receptor binding as a measure of toxicity. The results show that the concentrations of neither the compounds nor the mixtures were significantly reduced in Athabasca River water, although compositional changes occurred within the mixtures and Ah receptor binding potential was affected by photolysis. Photolysis at UV254 was the most effective radiation source applied in all instances.
Acknowledgments
The Panel on Energy Research and Development (PERD) and the University of Saskatchewan provided funding for this research. Thanks to Vincent Rogers, Mark Wickstrom, and Karsten Liber at the Toxicology Centre, University of Saskatchewan for the provision and use of the AOS naphthenic acid extract; Chrissy Herman and Natasha Neumann at the Meteorological Service of Canada for installation and maintenance of the CM11 radiometer; Sarah Armstrong and Steve Siciliano at the Soil Science Department, University of Saskatchewan for technical advice and laboratory support for the aryl hydrocarbon receptor assay; Shannon Braithwaite at WateResearch Corp for DOC analyses; and Tyler Birkham at the Department of Civil and Geological Engineering, University of Saskatchewan for Athabasca River water collection.