Alberta oil Sands: Investigating the chemical and biological evolution within fluid fine tailings-consequences for end pit lake development
THURSDAY, APRIL 12, 2012 - 3:30 PM TO 4:30 PM in PHY 313 at the University of Waterloo
Abstract:
The oil sands deposits in Northern Alberta are one of the largest oil reserves in the world, containing an estimated 2.5 trillion barrels of recoverable bitumen held in a mineral matrix consisting of sand, clay and water. The current practice is to store the tailings in large settling basins, to allow the solids to settle out by gravity forming a denser unconsolidated mass termed fluid fine tailings (FFT). FFT is transferred from settling basins into the mined-out pits, being proposed for a series of end pit lakes, a strategy for sustainable environments being evaluated in the Fort McMurray region. As these end pit lakes (EPL) evolve, significant changes in the physicochemical properties, microbiology and geochemistry can occur affecting both the volume and quality of the intended water cap. To date little information exists on the biogeochemical nature (redox mediated reactions) of the FFT product prior to deposition. Our research program is investigating both the chemistry and the microbial community structure within core samples collected from oil sands tailings basins. To compliment and confirm predictive models there is a need for detailed systematic studies bridging the physical (mineralogy) and chemical (redox chemistry abiotic vs. biotic; cycling of Fe and S) gradients observed. This presentation will provide highlights of past and ongoing investigations.