In-situ oil sands operations have been the dominant method of bitumen extraction in Canada since 2012; however, research on contaminants attributed to this method is limited in the peer-reviewed scientific literature, compared to that of open-pit mining. The Cold Lake oil sands region operates using exclusively thermal in-situ extraction techniques, raising the issue of whether oil sands activity is resulting in petroleum hydrocarbon (PHC) contamination in the absence of open-pit mines, upgraders, refineries, tailings ponds, and other bitumen processing operations. The lack of baseline contamination levels prior to oil sands development hampers debate on contamination from the oil sands industry. We address this shortcoming by using regional lake sediment cores to characterize petroleum hydrocarbons and trace their origin within the Cold Lake oil sands deposit. Petroleum hydrocarbons are hydrophobic compounds that bind to sediments, therefore persisting and accumulating in aquatic environments. This thesis examines historical levels of polycyclic aromatic hydrocarbons (PACs), petroleum biomarkers, and n-alkanes in radiometrically dated sediment cores collected from the depocenter of lakes within the Cold Lake heavy oil field. We used alkylated PACs and a suite of petroleum biomarkers to evaluate in-situ operations as potential petroleum-derived contamination sources. We predicted that similarly to open-pit mining, concentrations of PHCs in lake sediments would increase with industrial activity corresponding to proximity from in-situ operations. Like open-pit regions, alkylated PACs in Cold Lake sediments were elevated when compared to unsubstituted parent PACs and were significantly enriched in lake sediments deposited after the onset of oil sands operations. These findings imply that in-situ oil sands activity is driving the enrichment; however, diagnostic ratios and pyrogenic indices confirm a strongly pyrogenic origin in both pre-industrial and more recent sediments. When compared to a Cold Lake bitumen sample, the principal components driving PHC enrichment do not resemble bitumen. Likewise, diagnostic ratios of petroleum biomarkers and n-alkanes do not support bitumen as a significant source of hydrocarbons. PHC inputs in lake sediments are instead from terrestrial vegetation and plant waxes. These findings suggest that bitumen is not significantly contributing to petroleum hydrocarbon enrichment to lakes within the Cold Lake oil field; however, emissions from in-situ activity (natural gas burning, diesel trucks, seismic line cutting etc.) is increasingly abundant in more recent sediment. With >80 % of Canadian bitumen reserves requiring in-situ techniques for extraction, this thesis provides the first assessment of the spatial and temporal relationship between contaminant loading and proximity to in-situ oil sands operations. Additionally, this study allows for the environmental implications of open-pit mining operations to now be compared to that of in-situ techniques.

Bitumen exploitation in Alberta’s oil sand region generates considerable amounts of waste including tailings and process-affected water that needs reclamation. Water capped tailings technology (WCTT) is currently being assessed as a potential wet reclamation strategy in the oil sand by the commission of Base Mine Lake (BML), the first commercial scale Pit Lake. Pit Lakes consist of ~40m of fluid fine tailings (FFT) deposited in old mine pit covered with a ~10m water cap. In order to be successful, pit lakes much achieve the ecological roles of a natural lake, which includes colonization of the water by macrofauna therefore necessitating the water cap to be oxic. Due to the reductive nature of the tailings, oxygen consuming constituents (OCC) such as methane, sulfide and ammonia are released from the FFT into the water cap potentially posing a threat to the success of the reclamation. Additional seasonal effects such as stratification and ice cover may further affect oxygen consumption by isolating parts of the water cap therefore allowing accumulation of OCC. Results shows that BML thermally stratifies during the summer and winter and that oxygen persist throughout the water cap despite reaching low level at the FFT-water interface (FWI) during summer. Consistent with the FFT acting as an OCC source, aqueous CH 4 and NH 4+ concentrations were highest closer to the FWI, decreasing upwards into the water cap. Using linear regression CH 4 was shown to be an important OCC during the summer of 2015 while NH 4+ and CH 4 were both important for the summer of 2016 highlighting the emergence of nitrification in BML. Detailed analysis of seasonal data revealed that accumulation of OCC below the hypolimnion depletes oxygen and favors methanotrophic activity. Results from both studies suggest that methanotrophs have a competitive advantage at low oxygen levels against nitrifiers. / Thesis / Master of Science (MSc) / Bitumen extraction in Alberta’s oil sand region generates substantial amounts of waste including tailings that needs reclamation. Pit Lakes have been proposed as a reclamation strategy, where tailings are deposited into a mined-out pit and covered with a water cap. To achieve the reclamation goal, the lake must be able to sustain life and must therefore maintain an oxic water cap. The underlying tailings poses a threat to the oxygenation of the lake because of the constant release of compounds that have the potential to consume oxygen. Additional seasonal effects due to temperature change may further affect oxygen consumption by isolating parts of the water cap. In this thesis the results of two years of field sampling and analyses show that despite active oxygen consumption from tailings-released compounds, oxic status is achieved in the upper layer of the lake during summer and under ice.

An essential element of the reclamation strategy proposed by the oil sands mining industry in northern Alberta, Canada, includes the creation of wetlands for the bioremediation of mining waste materials. The mining process used to extract oil from these deposits results in the production of large volumes of process-affected water (OSPW) and sediments (OSPS), which must be incorporated into wetlands as a component of the reclaimed landscapes. Wood frogs (<i>Rana sylvatica</i>) are an abundant native species that might be expected to inhabit these reclaimed wetlands. The objective of this study was to determine potential detrimental effects of OSPW and OSPS on the growth and development of wood frogs. Several morphological (weight, length, condition factor) and biochemical (whole body tadpole thyroid hormone and triglyceride concentrations and metamorph hepatic glycogen concentration) endpoints were assessed in conjunction with hatchability and survivability of wood frog eggs and tadpoles exposed to process-affected materials (OSPM) under field and laboratory conditions.<p> As part of this study, assay techniques were optimized to enable simultaneous measurement of whole body 3,5,3-triiodothyronine (T3), thyroxine (T4) and triglyceride (TG) concentrations in wood frog tadpoles. These assays were used to monitor changes in T3, T4 and TG in wood frog tadpoles during development from hatching to metamorphosis (Gosner stages 19-46), to establish baseline levels for subsequent application of the assays to evaluate contaminant effects. The results indicated peak T3 and T4 concentrations occurred during metamorphic climax (Gosner stages 40-46) and prometamorphosis (Gosner stages 31-40), respectively. Maximal TG concentrations were also observed during prometamorphosis. These assays were further employed to assess body condition and development in wood frogs during a field study in 2005, and the following laboratory studies in 2006 and 2007.<p> In summer 2005, 29 reclaimed and five unimpacted wetlands were monitored for use by native amphibians, and tadpoles and newly-metamorphosed wood frogs were collected from a subset of sites as a preliminary assessment of contaminant effects. Endpoints such as metamorph hepatic glycogen and whole body tadpole T3, T4 and triglyceride concentrations were compared among six impacted and three reference wetlands. The surveys indicated 60% of OSPW-impacted wetlands were used by breeding adult amphibians, while wood frog tadpoles and newly-metamorphosed frogs were observed in 37 and 30% of OSPW wetlands, respectively. In general, lower whole body tadpole T3 and triglyceride concentrations were observed in wood frogs from wetlands containing OSPM. In contrast, hepatic glycogen concentrations in newly-metamorphosed frogs and whole body tadpole T4 and T3/T4 concentrations were comparable among the reference and impacted wetlands. In addition, the differences observed in total body weight and length of tadpoles and newly-metamorphosed wood frogs among OSPM and reference sites were likely due to minor differences in developmental stages of the animals collected from the various wetlands, rather than any contaminant effect.<p> In 2006 and 2007, wood frog eggs and tadpoles were exposed to several sources of OSPW and OSPS collected from reclaimed Suncor and Syncrude wetlands under controlled laboratory conditions. Hatchability was reduced in eggs exposed to water from only one of the OSPW sites, compared with the other process-affected ponds and the control water (P<0.05). In contrast, survivability of tadpoles was significantly reduced (P<0.05) in all the impacted sites in both years, with nearly all OSPW sites having <10% survival. The exposure study evaluated the toxicity of five types of OSPS. Results indicated no impact of OSPS exposure on survivability of tadpoles, but showed reduced whole body weight (in three OSPS treatments), length (in two OSPS treatments) and body condition (in one OSPS) of tadpoles exposed to process-affected substrates tested (P<0.05). Whole body T3 and T4 concentrations in tadpoles from OSPS treatments were not different from the control treatment, but tadpole TG concentration was reduced in groups exposed to two impacted substrates (P<0.05). Water quality measurements, including determination of dissolved metals were conducted in an initial attempt to relate any potential toxic effect on wood frog growth and development to specific contaminants.<p> Results of the laboratory studies strongly suggest that exposure to OSPW and OSPS may adversely affect wood frog growth and survival. However, these findings were not entirely consistent with field observations and results of concurrent mesocosm studies. Further research is therefore needed to fully evaluate the suitability of reclaimed oil sands wetlands to support indigenous amphibian population. Future work should focus on the cumulative effects of water and substrates, as well as the effect of OSPM ageing on acute and chronic toxicity.

An essential element of the reclamation strategy proposed by the oil sands mining industry in northern Alberta, Canada, includes the creation of wetlands for the bioremediation of mining waste materials. The mining process used to extract oil from these deposits results in the production of large volumes of process-affected water (OSPW) and sediments (OSPS), which must be incorporated into wetlands as a component of the reclaimed landscapes. Wood frogs (<i>Rana sylvatica</i>) are an abundant native species that might be expected to inhabit these reclaimed wetlands. The objective of this study was to determine potential detrimental effects of OSPW and OSPS on the growth and development of wood frogs. Several morphological (weight, length, condition factor) and biochemical (whole body tadpole thyroid hormone and triglyceride concentrations and metamorph hepatic glycogen concentration) endpoints were assessed in conjunction with hatchability and survivability of wood frog eggs and tadpoles exposed to process-affected materials (OSPM) under field and laboratory conditions.<p> As part of this study, assay techniques were optimized to enable simultaneous measurement of whole body 3,5,3-triiodothyronine (T3), thyroxine (T4) and triglyceride (TG) concentrations in wood frog tadpoles. These assays were used to monitor changes in T3, T4 and TG in wood frog tadpoles during development from hatching to metamorphosis (Gosner stages 19-46), to establish baseline levels for subsequent application of the assays to evaluate contaminant effects. The results indicated peak T3 and T4 concentrations occurred during metamorphic climax (Gosner stages 40-46) and prometamorphosis (Gosner stages 31-40), respectively. Maximal TG concentrations were also observed during prometamorphosis. These assays were further employed to assess body condition and development in wood frogs during a field study in 2005, and the following laboratory studies in 2006 and 2007.<p> In summer 2005, 29 reclaimed and five unimpacted wetlands were monitored for use by native amphibians, and tadpoles and newly-metamorphosed wood frogs were collected from a subset of sites as a preliminary assessment of contaminant effects. Endpoints such as metamorph hepatic glycogen and whole body tadpole T3, T4 and triglyceride concentrations were compared among six impacted and three reference wetlands. The surveys indicated 60% of OSPW-impacted wetlands were used by breeding adult amphibians, while wood frog tadpoles and newly-metamorphosed frogs were observed in 37 and 30% of OSPW wetlands, respectively. In general, lower whole body tadpole T3 and triglyceride concentrations were observed in wood frogs from wetlands containing OSPM. In contrast, hepatic glycogen concentrations in newly-metamorphosed frogs and whole body tadpole T4 and T3/T4 concentrations were comparable among the reference and impacted wetlands. In addition, the differences observed in total body weight and length of tadpoles and newly-metamorphosed wood frogs among OSPM and reference sites were likely due to minor differences in developmental stages of the animals collected from the various wetlands, rather than any contaminant effect.<p> In 2006 and 2007, wood frog eggs and tadpoles were exposed to several sources of OSPW and OSPS collected from reclaimed Suncor and Syncrude wetlands under controlled laboratory conditions. Hatchability was reduced in eggs exposed to water from only one of the OSPW sites, compared with the other process-affected ponds and the control water (P<0.05). In contrast, survivability of tadpoles was significantly reduced (P<0.05) in all the impacted sites in both years, with nearly all OSPW sites having <10% survival. The exposure study evaluated the toxicity of five types of OSPS. Results indicated no impact of OSPS exposure on survivability of tadpoles, but showed reduced whole body weight (in three OSPS treatments), length (in two OSPS treatments) and body condition (in one OSPS) of tadpoles exposed to process-affected substrates tested (P<0.05). Whole body T3 and T4 concentrations in tadpoles from OSPS treatments were not different from the control treatment, but tadpole TG concentration was reduced in groups exposed to two impacted substrates (P<0.05). Water quality measurements, including determination of dissolved metals were conducted in an initial attempt to relate any potential toxic effect on wood frog growth and development to specific contaminants.<p> Results of the laboratory studies strongly suggest that exposure to OSPW and OSPS may adversely affect wood frog growth and survival. However, these findings were not entirely consistent with field observations and results of concurrent mesocosm studies. Further research is therefore needed to fully evaluate the suitability of reclaimed oil sands wetlands to support indigenous amphibian population. Future work should focus on the cumulative effects of water and substrates, as well as the effect of OSPM ageing on acute and chronic toxicity.

In the last decade mineable oil sands production in Canada has grown rapidly. Constraints on the planning and design processes employed by surface mining oil sands operations vary in distinct ways from other commodities mined by both hard and soft rock open pit methods. The unique waste handling needs, including tailings disposal, of contemporary oil sands mining requires specific planning considerations. It is the purpose of this research to analyze and document a conventional hard rock, metal mine planning system, and contrast this with the unconventional mine planning system used by oil sands mines. Systems activity models of both the conventional and unconventional systems are developed in support of documenting and contrasting the two systems. Constraints unique to oil sands mine planning are identified and their impact on the oil sands mine planning system are documented. The impacts of challenging waste handling and storage requirements and a uniquely prescriptive regulatory environment defining mineable ore are identified as key constraints. The research concludes with a proposal for a new planning system to better support the planning of oil sands mines. The proposed system respects the unique waste management considerations in oil sands planning and revisits the current regulatory approach to ensuring resource recovery. The proposed system is compatible with traditional approaches to economic analysis in open pit planning, and with emerging best practices to manage technical and economic uncertainty, improve project optimization, and develop robust mine plans. / Thesis (Ph.D, Mining Engineering) -- Queen's University, 2012-10-02 17:52:18.223

A common challenge during deposition of slurries is segregation as large particles settle through the matrix of fines and water. Whether segregation occurs or not depends on the grain size distribution of the solids, the void ratio or solids content and the rheological properties of the fines-water matrix. The rheological characterization of slurry composed of different grain sizes and varying water chemistry was investigated. The vane yield stress was used to characterize different slurries composed of clay, silt and sand materials. Semi-empirical fractal theory showed good agreement with experimental data for fine slurry. Comparison of yield stress at same concentration but different composition showed a decreasing trend as the composition of either silt or sand material increases. The pore-water effect was studied for representative kaolinite slurry. The yield stress was insensitive for pH values in the acidic and neutral range, while in the basic range it showed significant response depending upon the type of the chemical used to achieve the pH: Ca(OH)2 and NaOH. A modified segmented standpipe was designed and used in a series of experiments to determine concentration profiles during the sedimentation processes. Analyses of the solid content profiles and sand content profiles in the standpipes indicated a capture of sand particles which could be correlated to the yield stress of the fines matrix. Theoretical calculations, however, showed over-prediction of the captured sand size. A correction factor of about 0.2 was applied. Flume test on a high solid content slurries showed that the dynamic segregation is governed by all the factors governing the static case. Beaching profile shapes were not a necessary indication of segregating and non-segregating type of slurries. Modified version plastic theory for flow slides was used to characterise profile shape. Computational fluid dynamics approaches based on kinetic theory and bi-viscous model analysis were implemented and showed a reasonable capability in modelling segregation when compared with experimental results. A statistical formulation for segregation index, SI, was proposed. The index accounts for variation in depth of samples. Finally recommendations for future research are proposed based on the observations and findings made from the study. / Geotechnical Engineering

Canada has the largest known reserve of oil in the world in the form of oil sands: an estimated 1.7 to 2.5 trillion barrels of oil are deposited in combination of the sand, water and clay. The presented research is devoted to bubble-solid surface interaction, which is one of the critical areas of the oil sand processing and it is also a key point for many other processing technologies, such as mineral recovery, froth flotation, soil remediation, de inking of paper, heat transfer in boilers tube, biological and medical sciences. The goal of this work was to investigate new theoretical and practical approaches, which would help in better understanding of fundamentals of the flotation process in oil sands extraction. Among many achievements of this research are: 1)development of the method for generation of a single micro bubble. Dependence of this process on micropipette tip size and inclination, gas type, taper length and other parameters has also been studied (Chapter 3); 2)study of gas bubble - flat surface interactions based on a practical approach of determination of two dynamic parameters, sliding velocity and induction time of a gas bubble. Various types of gas bubbles (CO2, Air, H2, and O2) and collector surfaces (bitumen, treated hydrophobic and hydrophilic silica) were used in sliding velocity and induction time measurements. The sliding velocity of gas bubbles under an inclined collector surface was found to be in a strong dependence of water chemistry, type of gases, temperature, initial separation between bubble and collector surface (Chapter 4); 3)developing an analytical model for predicting bubble sliding velocity based on previously developed models. The model was in a good agreement with experimental results (Chapter 5); 4)establishing a new method for bubble zeta potential measurements. The measurements were in a good agreement with previously studies reported in literature (Chapter 6). Summarized above findings from this research represent valuable advances in understanding oil sands processing. The prospects of future work are provided in Chapter 8. / Chemical Engineering

Chars were obtained from individual fuels and blends with different blend ratios of coal, coke and biomass in Drop Tube Furnace at different temperatures. Based on TGA experimental data, it was shown that the effect of the blending ratio of biomass to other fuels on the reactivity of the co-pyrolyzed chars is more pronounced on the chars prepared at lower temperature, due to the presence of synergetic effects originating from the interaction of the two fuels. SEM images showed differences in shapes and particle size of char particles from biomass and coal/coke. These also show the agglomeration of coal and coke chars with biomass char particles at high temperatures. The agglomeration may be the reason for the non-additive behavior of the blends. BET analysis showed increase in the surface area with an increasing temperature for biomass and coal, but the trend for coke was inversely related to the temperature. / Chemical Engineering

The purpose of this study is to investigate the impact of solvent addition to bitumen froth on the wettability of froth solids. The wettability of solids determines the transportation/partitioning of the solids between phases, which in turn affects the solids and water rejection in a Clark hot water extraction process (CHWE). The impact of solvents treatment on the wettability of froth solids was studied using both a model system and a real bitumen froth system. The vulnerabilities of four kinds of model minerals to hydrocarbon contamination/wettability alteration in different solvents were compared and discussed by considering solvent composition and mineral types. The wettability of solids extracted from the industrial froth using different solvents was also compared. The XRD analysis on these solids confirmed the partitioning behavior of solids observed in model solids system. The results from this study indicate that the composition of paraffinic/aromatic solvent in an industrial froth treatment process could be tailor-optimized to achieve a better solids/water rejection. / Materials Engineering

The impacts of oil sands processed materials (OSPM) on phytoplankton and periphyton community growth and stable carbon and nitrogen isotopes were examined. Estimates of plankton and periphyton community growth, measured as chl a and dry weight, were low and similar in reference and OSPM reclamation wetlands. The use of stable isotope analyses revealed higher δ15N of plankton and periphyton in OSPM wetlands than reference wetlands, possibly due to increased TN concentrations in some OSPM wetlands. In the laboratory, water-soluble fractions (WSF) of two types of OSPM (mature fine tailings, MFT and consolidated tailings, CT) and an amendment material (peat-mineral mixture), potential fill materials in wetland or end pit lake reclamation, were examined for phytoplankton community growth and stable carbon and nitrogen isotopes. All WSF treatments had higher chl a compared to reference water and maximum growth was observed at a 50:50 ratio of peat:CT or peat:MFT. In general, WSFs of peat had the highest concentration of total nitrogen (TN) whereas WSFs of MFT had the highest total phosphorus (TP; 3x higher). The results suggested that the addition of peat as an amendment to OSPM (particularly for MFT), contributing additional TN, could improve phytoplankton community growth in oil sands reclamation. At higher percentages of MFT WSF, there was increased turbidity due to fine clay particles that likely contributed to reduced phytoplankton growth. Turbidity could be an important factor limiting phytoplankton growth and thus reducing dietary resources and biological detritus (via sedimentation) in the initial development of an end pit lake. The WSFs also promoted the unfavourable growth of filamentous algae, highest at intermediate concentrations of peat and CT WSFs and inhibited in MFT WSFs due to light limitation. Stable N isotopes of plankton and filamentous algae suggests that 15N enrichment of algae could be a useful indicator of nutrient inputs, including OSPM seepage into natural aquatic systems, for oil sands regional monitoring programs.