Biodegradation of cycloalkanes under different redox conditions

Surface mining and hot water bitumen extraction operations have several issues; the significant one is the management of enormous volumes of fluid fine tailings. Non-aqueous solvent extraction (NAE) process has a potential to reduce environmental impact of oil sands activity by yielding high recovery of bitumen, eliminating production of fluid fine tailings and reducing dependence on fresh water consumption. In addition, mine sites might be reclaimed more rapidly using NAE solids mixed with pristine soils. After NAE extraction of bitumen, the majority of the solvent is recovered from the process and re-used, but a small portion of unrecovered solvent remains incorporated and co-deposited with NAE solids. Finding a way to safely and rapidly remove the unrecovered solvent from NAE will benefit mine site reclamation. Bioremediation is a cost-effective method to treat tailings containing hydrocarbons. The ability to use soil microbial communities for the degradation of residual solvent from NAE solids could reduce the environmental impact if NAE solids are deposited in pits or managed under upland or wetland scenario. In the proposed research, we will be simulating soil-pit (aerobic/anaerobic), upland (aerobic) and wetland (anaerobic) site conditions by setting up microcosm experiments at small-scale in the laboratory and investigate bioremediation of NAE solids impregnated with cyclopentane and cyclohexane under different redox conditions (aerobic, nitrate-reducing, sulfate-reducing and methanogenic).