Grant: Applied Research and Development Grants - Level 2

The oil sands industry is saddled with a tailings inventory exceeding 1.21 Bm3 (osip.alberta.ca). The majority of this volume is stored as mature fine tailings (MFT), a stable slurry suspension containing ~30% solids that can persist for decades. Reducing the volume of stored tailings by accelerating the rate of dewatering and densification is a high priority for oil sands operators. Several tailings treatment technologies have been developed 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 dewatering technology by accessing water trapped in suspension and releasing it to the environment through evapotranspiration, thereby increasing solids content and shear strength. The proposed study builds on previous work whereby native, upland, Boreal plant species were successfully augmented with amendments such as bacteria and hydrolyzed proteins to dewater thickened tailings and centrifuge cake. With the objective of targeting untreated MFT, the proposed study aims to develop a progressive, plant mediated dewatering technology capable of supporting plants on the surface of the fluid MFT. In addition, we will optimize a microbial and organic amendment to augment plant growth and investigate the mechanism by which plant growth is enhanced by examining nutrient content in the plant and soil, and gene expression from root associated 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 expertise from the Centre for Boreal Research, the Applied Bio-Nanotechnology Industrial Research program, and the Centre for Oil Sands Sustainability within the Northern Alberta Institute of Technology (NAIT), the molecular biology unit at the Laurentian Forestry Centre, and Canadian Natural. If successful, this project will result in a cost effective, progressive dewatering prototype capable of passively transforming tailings into a soil system suitable for reclamation, and will be scalable for field deployment