Speaker: Ian Vander Meulen, Watershed Hydrology and Ecology Research Division, Environment and Climate Change Canada
Abstract:
The “What? Where? How?” of Naphthenic Acids in the Athabasca Oil Sands Region
Ian J. Vander Meulen,1,2 Dena W. McMartin,2,3 John V. Headley1
- Watershed Hydrology and Ecology Research Division, Water Science & Technology Directorate, Environment and Climate Change Canada. National Hydrology Research Center, 11 Innovation Blvd, Saskatoon, SK.
- Department of Civil, Geological and Environmental Engineering, University of Saskatchewan. 57 Campus Drive, Saskatoon, SK.
- Department of Geography and Environment, University of Lethbridge. 4401 University Drive, Lethbridge, Alberta T1K 3M4, Canada
The Athabasca Oil Sands of northern Alberta, Canada are home to one of the largest global petroleum reserves identified to date. Surface mining generates oil sands process-affected water (OSPW). Despite the enormous complexity of OSPW, naphthenic acids (NAs) and associated naphthenic acid fraction compounds (NAFCs) have been consistently implicated as some of the primary drivers of aquatic toxicity. It is therefore important to understand what naphthenic acids are, where they occur, how they behave in aquatic environments, and what their subsequent fate is in the landscape. Because the oil sands region is ~50-60% wetlands by area, it is particularly important to understand how wetlands may affect chemical behaviour and succession of NAs and NAFCs over time. Empowered by modern high-resolution mass spectrometry analyses, new insights have been gathered that describe biological and physicochemical parameters and mechanisms affecting the behaviour & fate of NAs and NAFCs. These include work that shows how NAFCs mature differently in wetlands depending on the particular conditions of the receiving environments. Further, recent work has included survey studies describing the characteristics of NAFCs already present in the region’s abundant wetlands spatiotemporally. There has also been progress made on describing roles of plants and sediments in contributing to the fate of NAFCs in engineered wetland systems. Using these techniques, the work to comprehensively describe the environmental behaviours and fate of NAs and NAFCs continues such that we might anticipate the extent to which residual toxic effects may persist both on and in reclaimed landscapes.