Overview of Existing Science to Inform Oil Sands Process Water Release: A Technical Workshop Summary

Abstract

The extraction of oil sands from mining operations in the Athabasca Oil Sands Region uses an alkaline hot water extraction process. The oil sands process water (OSPW) is recycled to facilitate material transport (e.g., ore and tailings), process cooling, and is also reused in the extraction process. The industry has expanded since commercial mining began in 1967 and companies have been accumulating increasing inventories of OSPW. Short‐ and long‐term sustainable water management practices require the ability to return treated water to the environment. The safe release of OSPW needs to be based on sound science and engineering practices to ensure downstream protection of ecological and human health. A significant body of research has contributed to the understanding of the chemistry and toxicity of OSPW. A multistakeholder science workshop was held in September 2017 to summarize the state of science on the toxicity and chemistry of OSPW. The goal of the workshop was to review completed research in the areas of toxicology, chemical analysis, and monitoring to support the release of treated oil sands water. A key outcome from the workshop was identifying research needs to inform future water management practices required to support OSPW return. Another key outcome of the workshop was the recognition that methods are sufficiently developed to characterize chemical and toxicological characteristics of OSPW to address and close knowledge gaps. Industry, government, and local indigenous stakeholders have proceeded to utilize these insights in reviewing policy and regulations. Integr Environ Assess Manag 2019;15:519–527. © 2019 SETAC

Principles and Challenges for Multi-Stakeholder Development of Focused, Tiered, and Triggered, Adaptive Monitoring Programs for Aquatic Environments

“…Stressor-based designs, however, also have disadvantages. In some cases no standard measurement techniques or reference materials may be available, such as 'naphthenic acids' in oil sands process-affected waters [13,14]. Safe exposure levels or guidelines may also not be available or may not be applicable.…”

Microbubble-Enhanced Bitumen Separation from Tailing Slurries with High Solid Contents

“…In addition to the urgency of reducing the environmental footprint and greenhouse gas (GHG) emissions, recovering residual bitumen contents from the tailings using CO 2 bubbles can favorably speed up the process of consolidation and water release characteristics and shorten the time required for land reclamation. 3,4 As one of the most widely used techniques for particle separation, bubble flotation has benefited significantly from nanoscale phenomena using micro/nanobubbles to enhance sustainability. 5−7 Technical advantages exhibited in microbubble floating extraction are high separation efficiency and low economic costs.…”

“…Oil sand tailings contain clays, sands, residual bitumen, and organic chemicals. , Bitumen residues in tailings ponds form harmful components released into the environment with time and create hazardous habitation for the wildlife. In addition to the urgency of reducing the environmental footprint and greenhouse gas (GHG) emissions, recovering residual bitumen contents from the tailings using CO 2 bubbles can favorably speed up the process of consolidation and water release characteristics and shorten the time required for land reclamation. , …”

Microbubble Enhanced Bitumen Separation from Tailing Slurries with High Solid Contents

“…In addition to the urgency of reducing environmental footprint and greenhouse gas (GHG) emissions, recovering residual bitumen contents from the tailings using CO 2 bubbles can favorably speed up the process of consolidation and water release characteristics and shorten the time required for land reclamation. 3,4 As one of the most widely used techniques for particle separation, bubble flotation has benefited significantly from nanoscale phenomena by using micro and nanobubbles for enhancing sustainability. 5,6 Technical advantages exhibited in microbubble floating extraction are high separation efficiency and low economic costs.…”