Toxic metals in oil sands : review of human health implications, environmental impact, and potential remediation using membrane-based approach

Abstract

The upsurge in energy needs is the primary influencing factor for the shift of attention from conventional hydrocarbon resources to unconventional resources. In the process of exploiting unconventional oil resources such as oil sands, priority pollutants such as heavy metals are released into the environment. Thus, there are health and environmental risks associated with exploration and mining practices. This study seeks to present an overview of the health and environmental effects of these toxic metals in oil sands. Predominantly, the sources of these pollutants in oil sands are biogenic processes and weathering of source rocks. The toxicity of metals is dependent upon the nature of the metals as well as its affinity to bond with the silicate matrix. The consumption of plants and water from rivers, lakes, and streams with proximity to oil sand deposits could pose severe health risks to consumers, as significant amounts of Hg and other toxic metals are leached during oil recovery and other developmental processes. This review pointed to the use of membrane-based processes and other integrated approaches as vital remediation strategies employed for the restoration of resources to their pristine state and metal recovery. It is recommended that exploration practices and technologies should be improved towards the reduction of on-site metal pollution or off-site metallic contamination during refining or waste management.