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In situ measurements of soil nitrogen dynamics is a potential method for evaluating the health of constructed wetlands following oil sands mining. The objective of this study is to measure and compare the soil nitrogen availability of a reclaimed fen (Sandhill fen) with a nutrient-rich reference fen (Poplar fen) and a nutrient-poor reference fen (Pauciflora fen) in the Athabasca oil sands region of northern Alberta. Total Nitrogen (TN), Nitrate (NO3-) and Ammonium (NH4+) supply rates were determined along wetland hillslope transects using Western Ag Innovations Plant Root Simulator (PRSTM) probes at all three sites in 2014. Net N mineralization, net nitrification and net ammonification were determined simultaneously using the buried polyethylene bag sampling method. Overall, TN supply rates were greatest at the poor fen and least at the constructed Sandhill fen. In contrast, mineralization was greatest at the rich fen but again least at the Sandhill fen. Mineralization at the Sandhill fen was controlled evenly by ammonification and nitrification, whereas the two natural sites were controlled by ammonification. Relatively low N supply rates and mineralization at the Sandhill fen were likely due to lower soil organic matter and limited soil moisture in these newly constructed substrates. Spatial differences along the hillslopes also varied among sites. The Sandhill fen had higher TN supply rates at the upslope positions but no significant differences in net N mineralization rates along the hillslopes. The rich fen also had higher TN supply rates at the upslope but greatest mineralization rates downslope. These results highlight the importance of N storage and transport processes and offer insight into the N status of a constructed fen. / Thesis / Master of Science (MSc)

Oil sands mining in Alberta completely transforms the natural boreal landscape of upland forests, wetlands and lakes into open pits, tailings and overburden piles. By law, industry is required to return the landscape to its pre-disturbance land capability. While previous reclamation efforts have mainly focused on upland forest ecosystems, rebuilding wetland systems on soft tailings has only recently become a research focus. The dry, sub-humid climate and high salinity levels of underlying mining material complicate reconstruction of wetlands within this region. In 2012, Syncrude Canada Ltd. completed construction of the Sandhill Fen Watershed (SFW), a 52-ha upland-wetland system to evaluate wetland reclamation strategies. SFW includes an active pumping system, upland hummocks, a fen wetland and underdrains. This study examined the watershed-scale water balance in the first two years after commissioning (2013 and 2014). The first paper presents a semi-distributed water balance approach examining the fluxes and stores of different landscape units. Artificial pumping controlled the water balance in 2013, with approximately double the annual precipitation pumped in and out from May-Oct 2013, causing large water table fluctuations. In 2014, pump management was more passive, and water balance controlled by vertical fluxes. In the second paper, growing season ET rates and controls were assessed using data from three eddy covariance towers in the uplands and lowlands. Average ET rates between uplands and lowlands were similar, with average rates of 2.41 – 2.52 mm d-1. ET was radiatively controlled at all sites. Energy partitioning and ET rates are similar to natural boreal peatlands within the area, however upland areas are expected to increase in ET rates as LAI increases and vegetation matures. This study provides critical quantitative data on the early years of a highly managed watershed. Long-term monitoring is necessary, as water balance dynamics will evolve with vegetation development and climate cycles. / Thesis / Master of Science (MSc)

There is concern over the impact that petroleum related compounds (PRCs) associated with mining activity in the Athabasca Oil Sands Region (AOSR) are having on local wildlife. With the increase in oil sands mining activity in the AOSR there has been a corresponding decline in the fertility of indicator species in the AOSR. One of the primary sources of PRCs in the environment is oil sands process affected water (OSPW), which is stored in tailings ponds. Several PRCs, including naphthenic acid fraction components (NAFC), have endocrine disrupting effects, which may, in part, explain reduced fertility in indicator species. For example, male North American river otters (Lontra canadensis) living in areas impacted by mining activity have lower baculum strength those unaffected by mining activity. Weaker baculums are associated with increases in fracture rates and reduced fertility. Baculum strength is maintained throughout life by bone remodeling, a process that requires the differentiation of osteoblasts. NAFCs can impact several pathways integral to the development and path selection of mesenchymal stem cells into osteoblasts or adipocytes. Therefore, the objective of this thesis was to test the hypothesis that NAFCs inhibit osteoblast differentiation and induce adipocyte differentiation from progenitor cells. We exposed osteoblast progenitor cells and adipocyte progenitor cells to NAFCs. We demonstrated that NAFCs inhibit osteoblast differentiation and activate the glucocorticoid receptor pathway. We also found that NAFCs do not induce adipogenesis in adipocyte precursor cells. Lastly, we showed that NAFCs are PPARγ ligands that inhibit the expression of PPARγ associated genes. These insights into the effects of NAFCs on osteoblast and adipocyte progenitor cells suggest NAFCs may contribute to lower baculum strength and impaired adipose tissue function of animals living in the AOSR. These effects my reduce the fertility and population of wildlife in the AOSR. / Thesis / Master of Science (MSc) / There is concern that chemicals from oil sands mining in the Athabasca oil sands region are hurting the reproductive health of animals in the wild. Some of these animals, including bears, wolves, and river otters, need a bone in their penis called a baculum to reproduce. Studies have shown that some chemicals, including those from mining activity can make the baculum bone weaker. For bone to stay strong, bone cells always need to be developing to fix the bone tissue. The goal of our study was to find how chemicals from mining activity can affect the development of bone cells. We found that a group of chemicals that come from oil sands mining called naphthenic acid fraction components (NAFCs) stop bone cells from developing and making new bone. We also know that having more fat cells in bone is associated with weaker bones. We also looked at whether NAFCs could increase the development of fat cells. However, NAFCs did not increase the development of fat cells. Together, this research shows that NAFCs can make bones like the baculum weaker by slowing the development of new bone, but not by increasing fat cells. Our research suggests that exposure to NAFCs may make baculums weaker which may be bad for the reproductive health of animals living near oil sands mining activity.

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<p>The Athabasca oil sands produce 20% of Canada’s oil, which in turn creates trillions of cubic meters of waste. The Alberta government mandates that oil sands land be reclaimed to its natural state after mining has occurred. Syncrude Canada is currently creating a novel freshwater fen on top of a composite tailings (CT) deposit as a pilot large-scale reclamation project. CT are both microbially and sulfur rich, in addition, the fen could be a potential source of labile organics and sulfate reducing bacteria which could further stimulate sulfur cycling by microorganisms with the potential to stimulate H₂S_(g) generation, a health and safety concern. Therefore, this thesis examines three main research questions regarding this H₂S production within the Sandhill reclamation fen: 1) Is H₂S generation widespread within the porewaters of the CT and sand cap of the developing Sandhill Fen reclamation project? 2)<strong> </strong>Do microbial metabolisms capable of metabolizing Fe and S linked to H₂S generation occur within CT and sand cap of the developing Sandhill Fen? and 3) Will seasonality and ongoing fen construction impact H₂S generation?</p> <p>Field and experimental results herein discuss potential microbial and abiotic metabolisms and pathways that effect sulfur and iron cycling that could affect hydrogen sulfide generation within the composite tailings and developing fen during three seasonal sampling campaigns from June 2010 to July 2011. Results indicate that detectable H₂S_(aq) occurred in the fen porewaters during each sampling campaign, with a trend of increasing H₂S_(aq) concentrations as construction of the fen progressed. Further, enrichment results indicate that microbial sulfur and iron redox reactions are likely affecting the H₂S_(aq) generation. Experimental microcosm results indicate that the CT may contain unstable sulfur species that can contribute to H₂S_(aq) generation and sequestration in the CT as pyrite. Additionally, the evolution of the Sandhill Fen changed the microbial communities that were present <em>in situ</em> as well as shifted dominance of species type in environmental microbial enrichments. The putative function of these bacteria show a shift from autotrophy to increased heterotrophic metabolisms as the fen is being constructed, suggesting the addition of labile organic substrates from the peat and woody debris are both changing the dominant metabolisms and well as increasing microbial diversity to the underlying CT and sand cap of Sandhill Fen. Results of this thesis established widespread microbial Fe and S metabolisms within CT for the first time and indicated that fen reclamation will alter microbial activity with implications for S cycling within CT. Although this thesis covers a short sampling time frame, it is clear that H₂S_(aq) generation is an important factor to consider during large scale CT reclamation. While microorganisms are present and could be impacting Fe and S cycling, the CT materials should be investigated further in regards to their potential for H₂S_(aq) generation. More consideration should be given to inhibiting H₂S_(aq) generation or supporting FeS formation within the reclamation fen.<strong></strong></p> / Master of Science (MSc)

This Master’s degree study examined concentration and isotopic trends of dissolved methane, isotopic trends of phospholipid fatty acids (PLFA), and generated 1st order flux calculations to identify and assess biogeochemical cycling of dissolved methane in the first full-scale demonstration of EPL technology in the Alberta Oil Sands Region (AOSR). Base Mine Lake (BML) was commissioned by Syncrude Canada Ltd. in 2012 to facilitate the long-term storage and remediation of Fluid Fine Tailings (FFT) that are generated as a result of bitumen extraction via the Clark Hot Water Extraction (CHWE) processes. The results of this project provide evidence of methane oxidation by type I methanotrophs in BML, reducing dissolved oxygen concentrations in the hypolimnion layer. The FFT layer is identified as a source zone of fermentative methanogenesis, creating saturated conditions of dissolved gases. Dissolved methane is transferred to the water column primarily by advective processes related to FFT consolidation, while diffusion is a significant secondary transfer mechanism. Dissolved methane concentrations decrease significantly across the FFT-water interface where diffusive flux rates decrease by several orders of magnitude. Concentrations decreased linearly through the hypolimnion to trace concentrations by the metalimnion, resulting in a minor enrichment of δ13C of the residual dissolved methane pool. A minor enrichment of δ13C in C14:0, C16:0, and C16:1 PLFA coincided across the same interval, indicating utilization of a less depleted carbon source further away from the FFT-water interface where dissolved methane concentrations were lower. PLFA δ13C signatures were depleted relative to expected values of typical DOC substrates, further supporting the incorporation of a depleted signature by transfer of depleted carbon from dissolved methane. / Thesis / Master of Science (MSc)

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The objectives of this project were: 1) to ascertain the feasibility of using a two-stage foam separation system, with foam fractionation or air flotation as the second stage, to treat a tarsand extraction wastewater; and, 2) to evaluate the effects of four operational variables on the second stage performance. The wastewater was a tar-in-water emulsion collected during a steamflood extraction experiment conducted by the Department of Energy's Laramie Energy Technology Center on a tarsand deposit in eastern Utah. The four operational variables considered were chemical dose, hydraulic detention time, air flowrate, and temperature. To achieve these objectives a two-stage system was devised. In the first stage, polymer-aided air flotation removed the bulk of the tar. With the second-stage foam fractionation system, 16 trials were conducted using the cationic surfactant, EHDA-Br. In the second-stage air flotation system, 24 trials were conducted, eight with no polymer addition and 16 with the addition of the low molecular weight, strongly cationic polyelectrolyte, Betz 1195. Ten trials were then conducted at the set of conditions believed to give the best treatment of the water. The effluents were tested for TOC, COD, suspended solids (SS), and total solids. It was found that either of the two-stage systems would give TOC, COD, and SS reductions greater than 98 percent, although the polymer-aided air flotation system was found to be the best second stage process. The replicate trials consistently produced data very close to the best treatment achieved in the experimental trials, thus showing the reproducibility and stability of the two-stage process. / M. S.

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