Bugs and veggies as a progressive dewatering technology for untreated tailings

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The oil sands industry is saddled with a tailings inventory exceeding 1.21 Bm3 (osip.alberta.ca). The majorityof this volume is stored as mature fine tailings (MFT), a stable slurry suspension containing ~30% solids thatcan persist for decades. Reducing the volume of stored tailings by accelerating the rate of dewatering anddensification is a high priority for oil sands operators. Several tailings treatment technologies have beendeveloped to address this problem, however, current costs of implementation limit their deployment at scale.Previous studies have suggested that plants can be employed as a cost effective tailings capping or dewateringtechnology by accessing water trapped in suspension and releasing it to the environment throughevapotranspiration, thereby increasing solids content and shear strength. The proposed study builds on previouswork whereby native, upland, Boreal plant species were successfully augmented with amendments such asbacteria and hydrolyzed proteins to dewater thickened tailings and centrifuge cake. With the objective oftargeting untreated MFT, the proposed study aims to develop a progressive, plant mediated dewateringtechnology capable of supporting plants on the surface of the fluid MFT. In addition, we will optimize amicrobial and organic amendment to augment plant growth and investigate the mechanism by which plantgrowth is enhanced by examining nutrient content in the plant and soil, and gene expression from rootassociated microorganisms. We will also seek to understand how treatments affect the uptake of salts, metals,and hydrocarbons from the tailings into the plants. This highly interdisciplinary project combines expertisefrom the Centre for Boreal Research, the Applied Bio-Nanotechnology Industrial Research program, and theCentre for Oil Sands Sustainability within the Northern Alberta Institute of Technology (NAIT), the molecularbiology unit at the Laurentian Forestry Centre, and Canadian Natural. If successful, this project will result in acost effective, progressive dewatering prototype capable of passively transforming tailings into a soil systemsuitable for reclamation, and will be scalable for field deployment