One of the critical challenges in the Canadian oil sand industry is improving processes used to separate bitumen from oil sands and to remove clay particulates from produced oil. The fine clay particles are believed to play a significant role in the oil sands industry, from stabilizing process emulsions to fouling problems in water treatment. Addressing the problems caused by these fine clay particulates is limited by the ability to characterize the hydrocarbon-clay interactions. Scanning Transmission X-ray Microscopy (STXM) is used to study hydrocarbon-clay interactions in controlled model systems, where all components are known, and in process samples extracted from oil sands. To use STXM to study our desired systems, many experimental developments were required. Well developed sample preparation was needed to provide samples free from contaminants and experiments free of artifacts. Clean clays, free of extraneous carbon were required for model studies. A device to reduce photodeposition in the STXM chamber was also required to examine interactions of hydrocarbons on clay surfaces. <p>Using these developments, Near Edge X-ray Absorption Fine Structure (NEXAFS) spectra of model clays and model hydrocarbon mixtures were recorded using the STXM microscope on beamline 5.3.2 at the Advanced Light Source, in Berkeley CA. Using NEXAFS spectroscopy in conjunction with the STXM microscope, allowed us to explore preferential interactions between specific hydrocarbon and fine clay particles (smaller than 1 µm) in our model studies. We were also able to assess the chemistry of the hydrocarbons before association with the clay particles. <p>Process samples, consisting of a set of four bitumen froths extracted from the oil sands were investigated. The carbon chemistry of the froths was assessed and quantitatively analyzed. The findings were correlated with previous confocal microscopy results from our collaborators at CANMET Energy Technology Centre in Devon, Alberta.

This study was designed to determine if Alberta's sulfur blocks were inhabited by microorganisms which contribute to oxidation of elemental sulfur. The first objective was to elucidate a functional method of differentiating between viable and non-viable organisms in environmental samples. The second objective was to use this and other more established microbiological analyses to characterize the microbial population inhabiting the block and determine if they influence elemental sulfur oxidation.<p>In order to differentiate between viable and non-viable microorganisms, I relied on a DNA binding agent called ethidium monoazide bromide (EMA). Based on previous literature, I was able to test its activity in different environmental samples. Treatment with EMA inhibits the amplification of free DNA, whereas DNA protected by the membranes of viable cells is not affected. After finding that killed pure culture cells had a substantial reduction in their DNA amplification I proceeded to inoculate the same species of killed and viable cells into either soil, biofilm, or elemental sulfur samples obtained from Syncrude's Phase I sulfur block. I have found the EMA treatment to be sufficient at inhibiting amplification of DNA from non-viable cells inoculated into both the soil and sulfur samples, but not in the biofilms. <p>In achieving the second objective I designed experiments which tested in vitro and in situ samples of the sulfur block. Bioreactors containing microbiological inoculants from water running off the sulfur block were compared to sterile bioreactors for levels of acidity, sulfate accumulation and microbial population. Comparison between the surface block samples and the matrix samples showed a higher number of bacteria in the surface samples; however, the differences between the two bioreactor treatments were not significant. Bioreactors which received sterile water did not increase in acidity or sulfate accumulation. The two treatments which were inoculated with 10% sulfur block run off increased by 3 and 4.3 mM sulfate, and 8.6 x 10-3 and 1.8 x 10-2 hydronium ion concentration, in the surface and matrix treatments respectively. In situ samples obtained by coring the sulfur blocks showed that microbial inhabitants are present throughout the block depth profile with a discontinuous pattern, which could be attributed to the fractures associated with the solidification of the block and subsequent colonization. The level of microbiological inhabitants ranged from 2.5 to 5.5 log heterotroph colony forming units g-1 sulfur, and 3.19 x 101 to 1.62 x 102 A. thiooxidans amplified copy numbers, and 1.23 x 103 to 1.11 x 104 Eubacteria amplified DNA copy numbers ìg-1 of extracted DNA from EMA treated sulfur block samples. Most probable number counts for autotrophs only detected organisms along the 0-10 cm depth of the block. <p>The results of this study suggest that the use of ethidium monoazide bromide is a suitable method of detecting the large and varied microbial population inhabiting Alberta's sulfur blocks which can influence the level of block oxidation. The level of microorganisms present in the block is varied, which may parallel the varied pockets of air and water collected in the geomorphic fractures. Microbial communities residing in the sulfur block are partially responsible for sulfur oxidation. Methods aimed at reducing the level of sulfur oxidation must aim to reduce both the chemical and biological pathways leading to sulfur oxidation.

The adsorption characteristics of an oil sands tailings water (OSTW) mixture of naphthenic acids were determined using a batch partitioning method for two soils from the Alberta oil sands region. The soils were mineral peat mixtures produced during salvage operations, with Soil 1 having a higher organic carbon fraction (foc) than Soil 2. Naphthenic acids are a significant toxic byproduct of bitumen extraction, and are acutely toxic to aquatic organisms. The sorption of naphthenic acids as affected by a high ionic strength solution was examined using a synthetic groundwater (SGW) mixture.<p>The adsorption isotherms were found to be linear in all cases. All tests were conducted at 4oC, and at a pH of 8.0 ± 0.4, reflective of the conditions in a tailings settling facility near Fort McMurray, AB. The adsorption characteristics of the naphthenic acids in the SGW solution were compared to that of the mixture in Milli-Q water for the two soils. In the presence of SGW, the adsorption coefficient (Kd) for the mixture of naphthenic acids on Soil 1 was an order of magnitude higher than that observed with the same soil and the Milli-Q water mixture, increasing from 1.9 ± 0.2 mL/g to 17.8 ± 1.5 mL/g. The adsorption coefficient for the mixture of naphthenic acids on Soil 2 was also observably higher in the SGW mixture, increasing from 1.3 ± 0.15 mL/g to 3.7 ± 0.2 mL/g. In order to determine whether preferential sorption is exhibited by a particular species within the mixture, the relative fractional abundance of the individual naphthenic acids was plotted as a 3-dimensional histogram for carbon numbers 5 to 37. It was found that for all Z families (where Z is a measure of the number of carbon ring structures), naphthenic acids within the middle range of carbon numbers showed preferential sorption. A two sample t-test confirmed that the naphthenic acids in the carbon number groupings 15 to 24 and 25 to 37 sorbed significantly in the SGW mixture when compared to those in the carbon number grouping of 5 to 14. It was concluded that select constituents of oil sands naphthenic acids mixtures sorb strongly to soil under conditions of elevated salinity and therefore adsorption could be an important attenuating mechanism in groundwater transport. Furthermore, preferential sorption of the individual naphthenic acids is important with respect to toxicity since lower molecular weight naphthenic acids are believed to have a more pronounced toxic effect. Overall, the measured adsorption coefficients indicate that there can be significant sorption of OSTW derived naphthenic acids to soils.

Syncrude Canada Ltd (Syncrude) Mildred Lake operation is the largest producer of crude oil from oil sands mining in Canada. A saline-sodic clay-shale overburden known as the Clearwater Formation (Kc) must be removed in order to access the oil-bearing McMurray Formation (Km). The potential concerns associated with the reclamation of overburden structures include shale weathering and salt release and migration, resulting in salinization of groundwater, surface water, and reclamation soil covers. South Bison Hill (SBH) is one example of a Kc overburden structure located at the Syncrude Mildred Lake Operation. The general objective of this study is to develop a preliminary conceptual/interpretative model of the hydrogeology of the newly reclaimed SBH at the Syncrude mine site. A number of tasks were undertaken to meet this general objective. The first, and most important aspect of this study was to develop a geological model of SBH including pile geometry and depositional history of the hill. Secondly, to gain an understanding of the field conditions, a program was carried out over 2002 and 2003 to obtain pile physical characteristics. The geological model revealed that there are four main geological sections of SBH of different materials using different construction methods. The field data were used to verify the geological model, which illustrated the differences in hydraulic conductivities and geochemical signatures between the different sections. All information was used to develop a simple steady-state numerical seepage model of SBH to be used as a tool to investigate the response of the water levels of SBH to variations in the model parameters. The model illustrated that groundwater flow is largely controlled by a more permeable section on the south side of SBH and an unstructured Kc fill at the base of the pile. A sensitivity analysis was conducted on the model changing the flux into the pile, the permeability of the materials, and most importantly the head value of the tailings facility located on the north side both showing to be influential on the elevation of the water table through SBH.

Currently there are three companies producing bitumen from the Athabasca Oil Sands Region located near Fort McMurray, Alberta, Canada. Extraction of bitumen produces solid (sand) and liquid (water with suspended fine particles) tailings material, called oil sands process affected-materials (OSPM). These waste materials are stored on site due to a zero discharge policy and must be reclaimed when operations end. The OSPM is known to contain naphthenic acids (NAs) and polycyclic aromatic hydrocarbons (PAHs) and has high pH and salinity. A possible method of reclamation is the wet landscape approach, which involves using OSPM to form wetlands that would mimic natural wetland ecological functioning. This study investigated the effects of wetlands formed with OSPM on wood frog larvae (<i>Rana sylvatica</i>), using endpoints including survival, growth, time to metamorphosis, hormonal status, and detoxification enzyme induction [ethoxyresorufin-o-dealkylase (EROD) activity].<p> <i>In-situ</i> caging studies were completed in 2006 and 2007. Four wetlands were studied in 2006 and 14 wetlands were studied in 2007. The 2006 season saw a host of problems that were resolved for the 2007 season. In 2006, tadpole survival did not differ among reference wetlands and old OSPM-affected wetlands but there was 100% mortality of tadpoles in the young OSPM-affected sites that contain the highest concentration of toxic components. Results were similar in 2007, with tadpoles raised in young OSPM-affected wetlands having 41.5%, 62.6%, and 54.7% higher tadpole mortality than old OSPM-affected, young reference, and old reference wetlands, respectively. In 2007, tadpoles from young OSPM-affected sites had delayed metamorphosis (12 days longer than tadpoles from old reference wetlands and 18 days longer than tadpoles in old OSPM-affected wetlands). The thyroid hormone ratios of tadpoles in young OSPM-affected wetlands were between 25% and 42% lower than tadpoles in all other wetlands groups. The EROD activity of tadpoles in young OSPM-affected wetlands was an average 223% higher than those in old OSPM-affected wetlands, showing us that tadpoles were responding to higher levels of contaminants in young OSPM-affected wetlands. Size differences were only noted in 2007, most likely not as a result of exposure to OSPM, but due to differences in population density. The results of this study lead us to believe that toxicity due to OSPM decreases as wetlands get older and OSPM-affected wetlands could support native amphibian populations if they are allowed to mature. Since we considered wetlands to be old if they were seven years or older and the fact that old-OSPM wetlands showed effects on tadpoles similar to those of reference wetlands and showed much less toxicity than young OSPM-affected wetlands, we believe wetlands that are at least seven years old would sustain amphibian life.

Ecosystems are disturbed to extract synthetic crude oil from the Athabasca Oil Sands Region (AOSR) in northern Alberta, Canada. Successful reclamation of mined oil sands sites depends on maximizing water storage and minimizing the potential for erosion. Soil water repellency in the AOSR affects undisturbed sites and consequently reclamation materials. Extreme water repellency may lead to low infiltration rates and hinder reclamation. There is a lack of information about the naturally occurring and pre-existing levels of soil water repellency in the AOSR. Thus, questions arise about the degree of naturally occurring water repellency and the potential for severe water repellency in reclamation soils. Studies were conducted on nine sites in the AOSR in the summers of 2008 and 2009. A range of undisturbed and reclaimed sites, as well as mineral and organic reclamation materials were examined. Five undisturbed Jack Pine stands (classified as A ecosites), four reclaimed sites and reclamation materials including mineral soil, peat and leaf and lichen covering the forest floor (LFH) were studied. For a comparison of methods, one grasslands site in central Saskatchewan was included. Mini and standard tension infiltrometers were compared as a means of measuring soil water repellency index (RI). There was strong variability in RI values between the infiltrometer methods. The mean RI values from the mini infiltrometers were higher than from the standard infiltrometer (9.61 and 3.46, respectively). The variability within sites dominated the variability in RI for the two methods. Despite these obvious trends, RI values between infiltrometer sizes were statistically different for only two individual sites. Increasing the number of sampling points in the second field season did not reduce the variability. The simpler, less expensive mini infiltrometer is as effective as the standard infiltrometer in measuring soil water repellency. This will enable more efficient and extensive monitoring of soil water repellency in reclaimed and undisturbed sites in the AOSR. Soil water repellency of reclaimed and undisturbed sites was investigated in situ using RI, the water droplet penetration time (WDPT) test, and the molarity of ethanol droplet (MED) test. These measures showed similar trends. Variability in soil water repellency was high at both reclaimed and undisturbed sites. The average RI value for the surface of reclaimed sites was higher than that of the subsurface at reclaimed sites; however, there were no statistical differences between RI values of surface reclaimed and undisturbed sites (P =0.213) due to high spatial variability. The critical water content (CWC) of reclamation materials was determined by measuring the contact angle (CA) and WDPT. Generally, CA and WDPT were inversely related to water content, though variability was high and the relationship between water content was weak. The clearest relationship between water repellency and water content was present for the mineral soil samples. Reclaimed mineral soil was generally wettable above gravimetric water contents of 5-10 %, while the coarse textured tarball affected materials were only subcritically water repellent. There was no relationship between water repellency and water content for peat and LFH. The degree of water repellency was statistically higher for peat materials with increasing decomposition levels. The average WDPT was 44, 128 and 217 s for fibric, mesic, and humic peat, respectively. With careful management and monitoring, water repellency may not be a major limitation to reclamation success. The mini tension infiltrometer is an effective method for monitoring soil water repellency in the AOSR.

In an effort to better understand the impacts of nitrogen oxides (NOx) emissions from oil sands development on soils and vegetation, a laboratory experiment was designed, which mimicked the natural and reclaimed boreal forest environment found in the Fort McMurray area. The primary objective of this research was to examine the effects of various types and concentrations of NOx under a controlled laboratory study, and to provide recommendations and management strategies with respect to NOx deposition management. Findings indicated that, for some vegetation types, significant relationships exist between NOx treatment and vegetation height, biomass, and percent total nitrogen responses. Furthermore, some soil chemical parameters exhibited significant differences due to treatment and or soil depth, and some appeared to serve as better indicators of NOx deposition. Recommendations are made with respect to future research considerations and management strategies for NOx emissions including consideration of both eutrophication and acidification potential.

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