Exploring the potential for algal-based bioremediation strategies and toxicological profiling of oil sands process-affected water
Abstract
The generation of toxic tailings water from the Athabasca Oil Sands via hot water extraction processes poses a serious threat to the future sustainability of the region. Liquid tailings are stored in settling ponds on company leases where they continue to accumulate. The absence of an economically feasible method to treat this waste water and unclear environmental guidelines regarding remediation of this waste water has resulted in enormous ponds contaminated with napththenic acids (NAs) and other petroleum organics. An effective solution for sufficient remediation of the tailings ponds and oil sands process-affected water (OSPW) prior to mine closure is critical. To address this issue, we have initiated a study to explore the potential for algal-based bioremediation strategies. We have identified the species Dunaliella tertiolecta as being capable of degrading model NAs as well as a fraction of classical NAs found in OSPW. Furthermore, we have demonstrated enhanced in situ detoxification of OSPW through the biostimulation of indigenous photosynthetic organisms by phosphate supplementation. Detoxification appears to be linked with the reduction of sulfonate compounds which suggest toxicity is not predominantly caused by NAs as was previously believed. In addition to algal remediation studies, we developed the yeast Schizosaccharomyces pombe as a toxicological indicator for OSPW toxicity. Chemical genetic screens corroborate sulfonate toxicity in OSPW and transcriptomic investigations generated hypotheses regarding the mode of OSPW toxicity at the cellular level. Transcriptomic studies suggested that OSPW contaminants affect the integrity of biological membranes and incur oxidative stress. Because the mode of OSPW toxicity is poorly understood, we believe these studies contribute to the need for a comprehensive understanding of OSPW toxicity for site monitoring and remediation purposes.
Description
Keywords
Biology--Cell, Biology--Molecular, Physiology
Citation
Quesnel, D. M. (2015). Exploring the potential for algal-based bioremediation strategies and toxicological profiling of oil sands process-affected water (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/26116