Can the toxicity of naphthenic acids in oil sands process-affected water be mitigated by a green photocatalytic method?

FACETS

Jessie Reynolds¹  Diane M. Orihel²  Barry N. Madison²  Lauren Halliwell³  John V. Headley⁴  Kerry M. Peru⁴  Frank Gu⁵  Tim Leshuk⁵ 

[1] Department of Biology, Queen’s University, Kingston, ON K7L 3N6, Canada;School of Environmental Studies, Queen’s University, Kingston, ON K7L 3N6, Canada Department of Biology, Queen’s University, Kingston, ON K7L 3N6, Canada;School of Environmental Studies, Queen’s University, Kingston, ON K7L 3N6, Canada;Water Science and Technology Directorate, Environment and Climate Change Canada, Saskatoon, SK S7N 3H5, Canada;Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON N2L 3G1, Canada Department of Chemical Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada;

关键词: oil sands;    naphthenic acids;    green engineering;    ecotoxicology;    fish;   

DOI  :  10.1139/facets-2019-0053

来源: DOAJ

【 摘 要 】

Our study evaluates the efficacy of a “green” (i.e., sustainable, recyclable, and reusable) technology to treat waste waters produced by Canada’s oil sands industry. We examined the ability of a novel advanced oxidative method—ultra-violet photocatalysis over titanium dioxide (TiO2)-coated microparticles—to reduce the toxicity of naphthenic acid fraction components (NAFC) to early life stages of the fathead minnow (Pimephales promelas). Lengthening the duration of photocatalysis resulted in greater removal of NAFC from bioassay exposure waters; low- and high-intensity treatments reduced NAFC concentrations to about 20 and 3 mg/L (by Fourier-transformed infrared spectroscopy, FTIR), respectively. Treatments reduced the acute lethality of NAFC to fathead minnows by over half after low-intensity treatment and three-fold after high-intensity treatment. However, incomplete degradation in low-intensity treatments increased the incidence of chronic toxicity relative to untreated NAFC solutions and cardiovascular abnormalities were common even with >80% of NAFC degraded. Our findings demonstrate that photocatalysis over TiO2 microparticles is a promising method for mitigating the toxicity of oil sands process-affected water-derived NAFC to fish native to the oil sands region, but the intensity of the photocatalytic treatment needs to be considered carefully to ensure adequate mineralization of toxic constituents.

【 授权许可】

Unknown