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Ozonation degrades all detectable organic compound classes in oil sands process‐affected water; an application of high‐performance liquid chromatography/obitrap mass spectrometry
Author(s) -
Pereira Alberto S.,
Islam MD Shahinoor,
Gamal ElDin Mohamed,
Martin Jonathan W.
Publication year - 2013
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.6688
Subject(s) - chemistry , orbitrap , naphthenic acid , oil sands , mass spectrometry , electrospray ionization , chromatography , electrospray , degradation (telecommunications) , tailings , environmental chemistry , ozone , organic chemistry , corrosion , cartography , asphalt , computer science , geography , telecommunications
RATIONALE Surface mining of bitumen in Northern Alberta, Canada, results in large volumes of toxic oil sands process‐affected water (OSPW) that must be contained in tailings ponds. Ozonation has shown great promise as an OSPW treatment process, by decreasing its toxicity and increasing its biodegradability, but the effect of ozonation on the thousands of dissolved organic chemical groups has not yet been examined. METHODS Reversed‐phase liquid chromatography with ultrahigh‐resolution linear ion trap‐orbitrap mass spectrometry was applied to the characterization of treated (utilized ozone doses of 20 and 50 mg O 3 /L) and untreated OSPW. The analysis was performed in positive and negative electrospray ionization modes for each sample (ESI + /ESI – ). RESULTS Semi‐quantitative analysis of ozonated and unozonated samples allowed degradation to be monitored for naphthenic acids (i.e. O 2 species in ESI – mode) and >2000 other organic species belonging to various heteroatom‐containing classes: O x (where x = 1 to 6), NO x (where x = 1 to 4), SO x (where x = 1 to 4), NO 2 S, N, and S. No chlorinated byproducts were detected in any treated sample, but at the low dose (20 mg O 3 /L) some compound classes increased in abundance (e.g. the O 5 class), indicating that they were formed as byproducts at faster rates than they were degraded. Nevertheless, all organic compound classes subsequently diminished at the higher dose (50 mg O 3 /L). For several O x and SO x classes, species observed in ESI + mode (e.g. O 2 + species) were often more recalcitrant to ozonation than the corresponding species detected in ESI – mode (e.g. O 2 – species; naphthenic acids). CONCLUSIONS Ozonation appears to be a very suitable treatment option for OSPW, but the more recalcitrant groups of compounds may help to explain the residual toxicity of ozonated OSPW. Analysis of OSPW constituents in both ionization modes is warranted in all future OSPW fate studies. Copyright © 2013 John Wiley & Sons, Ltd.