Elemental sulphur (S⁰) is removed from sour gas deposits (high H₂S) during refinement. The resulting S⁰ is often stored onsite when the costs of shipping S⁰ to market exceeds the costs of storing it in large above ground blocks. With the aid of acidiphilic bacteria, atmospheric air and water oxidize S⁰ to sulphate (SO₄^2-). Long term storage is under consideration; however, oxidation rates and the role of each oxygen source (O_2(g) and H₂O) is not clear. S⁰ oxidation experiments were conducted over a range of temperatures (6-32¡ãC) to investigate reaction rates and isotopic fractionation of O and S isotopes during oxidation. The experiments also investigated the effect of integrating S⁰ oxidizing microorganisms and available nutrients on both the reaction rates and isotope fractionation. Results indicated > 95% of total SO₄^2- generated can be attributed to autotrophic microbial activity. Experiments conducted in a nutrient rich mineral solution showed rates increase with temperature from 0.16 (6¡ãC) to 0.98 (32¡ãC) ¦Ìg S⁰ cm^-2 d^-1 (Q₁₀ ¡Ö 1.7 - 1.9). Experiments conducted in a nutrient poor solution (deionized water) showed oxidation rates did not increase with temperature (0.06 to 0.08 ¦Ìg S⁰ cm^-2 d^-1) between 12 and 32¡ãC. Oxygen isotope analysis of the generated SO₄^2- indicated essentially all oxygen incorporated into the SO₄^2- originated from H₂O. In addition, effluent samples obtained from S⁰ block effluent at SCL indicated ¦Ä¹⁸O_(SO4) generally reflected the ¦Ä¹⁸O_(H2O) in the system at the time of oxidation. While covering the S⁰ blocks with an impermeable cover would undoubtedly minimize total SO₄^2- accumulation in block effluent, the results of this study suggest ¦Ä¹⁸O_(SO4) can also be used to track water movement through the block.

The oil sands operations in northeast Alberta, Canada, employ unconventional processes to produce synthetic crude oil (SCO). Because the extracted bitumen, ¡®the form of oil in oil sands¡¯, is highly viscous, it requires thermal upgrading to produce SCO. Coking technology is used to convert heavy bitumen fractions to lighter volatile fractions. During this process, an enormous volume of solid coke is produced and the metal impurities (e.g. Al, Fe, Mn, Ni, Ti and V) present in bitumen fractions end-up in the coke particles. As coke demands significant space for storage, oil sands companies are exploring options for placing coke into reclamation landscapes for long term storage and recovery. However, coke holds appreciable amounts of potentially leachable metals that may impede the performance of reclamation landscapes. Although two previous coke leaching studies had showed that coke released metals into water at concentrations exceeding the Canadian guidelines for the protection of aquatic life, the ecotoxicological hazard and risk of these metals were not well characterized. Therefore, the overall goal of this research was to characterize the fate and toxicity of metals associated with coke. In this research, the toxicity of coke leachates collected from oil sands field sites and those artificially generated in the laboratory were evaluated using a standard three-brood Ceriodaphnia dubia tests. Coke leachates (CLs) collected over a period of 20 months from two field lysimeters were found to be acutely toxic to C. dubia. Vanadium concentrations were significantly higher (p¡Ü0.05) than concentrations of all other metals in CLs from both lysimeters, and also in leachates from a laboratory batch renewal leaching study. Furthermore, toxic unit (TU) calculations suggested that Ni and V were likely the cause of CL toxicity, but this was not explicitly proven. Therefore, a chronic toxicity identification and evaluation (TIE) approach was adopted to identify and confirm the cause(s) of CL toxicity. Coke was subjected to a 15 day batch leaching process in the laboratory at pH 5.5 and 9.5 in order to characterize the effect of pH on metals release from coke, and to generate CLs for use in TIE tests. The 7-day LC50 estimates for C. dubia survival were 6.3% and 28.7% (v/v) for CLs generated at pH 5.5 and 9.5, respectively. The dissolved concentrations of Mn, Ni and Zn were high (p¡Ü0.05) in pH 5.5 CL, whereas Al, Mo and V were high (p¡Ü0.05) in pH 9.5 CL. Evidence gathered from a series of chronic TIE tests revealed that Ni and V were the cause of toxicity in pH 5.5 CL, whereas V was the primary cause of toxicity in pH 9.5 CL. Further, the influence of bicarbonate, chloride and sulfate ions on metals release, speciation and Ni and V toxicity was investigated. The type and amount of metals released from coke was significantly influenced by the ion type elevated in the leaching solution. Specifically, sulfate influenced mobilization of Ni, Fe, Mn and Zn from coke, whereas bicarbonate enhanced Al, Mo and V releases from coke. With respect to toxicity, increasing bicarbonate decreased the 7-day Ni2+ IC50 from 6.3 to 2.3 ¦Ìg Ni2+/L suggesting enhanced Ni toxicity at high pH or alkalinity. Conversely, sulfate showed a protective effect against V toxicity to C. dubia. The research presented in this thesis suggests that coke will not be inert when stored in reclamation landscapes and that metals, particularly Ni and V, could reach ecotoxicologically relevant levels in surface waters or substrate porewaters, under favourable leaching conditions. Operationally, efforts should focus on remediation and monitoring of metals released from coke, particularly Ni and V, in impacted wetlands, especially before discharging water into natural wetlands and/or local streams and rivers.

The origin of the acoustic emissions from a bed of musical grains, impacted by a pestle, is sought in a boundary layer at the leading front of the pestle. The frequencies of the shear modes of vibration in such a layer are compared with the observed frequencies. It is assumed that such a layer is the result of the fluidization of the grain asperities due to the high stress level at the front end. Such a boundary layer can also account for the emissions from plates of sand sliding on a dune surface and from grains shaken in a jar.

The tailings pond at the Muskeg River Mine is a large structure with a 11 km-long ring dyke that contains process affected water (PAW) and tailings sand. The dyke is made of permeable tailings sand and therefore it is equipped with seepage collection ditches that are designed to collect water from drains in the dyke but also to intercept seepage water not collected by the drains and transmit it to the seepage pond for recycling. The effectiveness of this seepage collection system was examined at the downgradient end of the tailings pond (Study Area) where near-surface permeable sand is present. <br /><br /> Piezometric level measurements were performed and water samples were collected from a network of 21 piezometers and drive points, and at several other critical locations. Concentrations of major chemical tracers of PAW such as naphthenic acids (NAs) show signs of migration of PAW in the permeable sand deposit, beyond the dyke. This interpretation is supported by stable O and H isotope analysis of water. The interpretation of the piezometric and chemical data revealed that the PAW has migrated past the Inner Ditch but not beyond the Outer Ditch. Elevated hydraulic heads beyond the Outer Ditch prevented further migration. Groundwater locally converges and discharges as surface water in the wet area between the two ditches. Thus, the collection ditch system is currently working effectively to contain PAW. <br /><br /> Numerical modeling of the Study Area was able to reasonably recreate the observed hydraulic conditions. Based on these simulations, it is possible that PAW may be migrating through a permeable layer of sand under the bottom of the dyke and pond, and eventually discharging into the wet area between the ditches. The estimated amount of PAW seepage discharged into the wet area is small compared to the total dyke drainage collected by the ditches. <br /><br /> These conditions described above, however, may change with the progress of the current dyke expansion work. The wet area between the ditches will be buried and the local hydraulic condition is expected to alter. This may reverse the hydraulic gradient across the Outer Ditch and perhaps will facilitate migration of PAW beyond the Outer Ditch. It is recommended that the following key chemical parameters be used in future groundwater quality monitoring efforts to track PAW migration at the Muskeg River Mine: Na⁺ Cl^- , SO₄^2- , and Ca²⁺ ions, stable isotopes of hydrogen and oxygen, and Naphthenic acids (NAs. )

Oil sands mining operations in northeastern Alberta are rapidly expanding. Upgrading and extracting the bitumen from the sand requires large volumes of water generating large quantities of oil sands process water/materials (OSPM) which is high in organic content. Some of the major organic components found in OSPM include unrecovered bitumen, polycyclic aromatic compounds (PACs), naphthenic acids (NAs) and humic acids. Concerns of acute and chronic toxicity resulting from OSPM have led to provincial legislation preventing the discharge of OSPM into local water and mandating the reclamation of areas affected by oil sands mining. To date, OSPM is stored on lease in settling basins while the mining companies evaluate reclamation strategies. One of the reclamation strategies involves the use of wetlands constructed with differing amounts of OSPM and organic amendments such as peat. Currently, numerous wetlands, both natural and constructed, are present on oil sands leases. To determine the sustainability of these wetlands for reclamation, the assimilation and flow of carbon and nitrogen within the systems need to be defined. Stable isotope analysis can enhance this understanding. To effectively use stable isotopes in the field, there is the need to determine the changes in stable isotope values occurring from the microbial degradation of organic components such as NAs which contribute a significant portion to the dissolved organic carbon (DOC) in reclamation sites. This study examined the microbial degradation of commercial and oil sands derived NAs by oil sands derived microbial cultures. Changes in stable isotopes values in the biomass (δ13C, δ15N), DOC and dissolved inorganic carbon (DIC) (δ13C) arising from degradation of the DOC were tracked in both static and semi-continuous tests. Utilization of commercial and oil sands derived NAs resulted in minimal change of the DOC stable isotope values. The biomass was 13C enriched for both the commercial (0.3 to 2.9 per mil (‰)) and oil sands derived NAs (3.7 to 8.5 ‰) relative to the DOC stable isotope values. DIC stable isotope values showed higher variability (-5 to +5.5 ‰). The semi-continuous tests showed biomass that was 15N enriched (3.8 to 8.4 ‰) with the assimilation of ammonium. Isotope trends established in the laboratory study provide further understanding into assimilation of carbon and nitrogen compounds in the field. DOC and DIC concentration and carbon stable isotope values were determined for water sampled from 13 oil sands aquatic reclamation sites varying in age, construction and organic material. Both DOC and DIC concentrations were elevated in OSPM affected sites, by an average of 40 mg/L for DOC and 83 mg/L for DIC concentrations. DOC concentrations were also elevated by approximately 10 mg/L at high organic sites. δ13C DOC values were slightly 13C enriched in young sites: 0.6 ‰ compared to δ13C DOC values at the mature sites. Also, from June to July 13C enrichment (0.3 to 1.9 ‰) of the DOC for all sites was seen. Corresponding with the enrichment seen in the DOC, 13C depletion (-8.8 to -0.3 ‰) of the DIC was seen for most sites from June to July. The trends seen from June to July may be a result of the release of readily degradable organics from the spring thaw stimulating the microbial community. The baseline values determined for DOC and DIC may assist future field food web studies.

The tailings pond at the Muskeg River Mine is a large structure with a 11 km-long ring dyke that contains process affected water (PAW) and tailings sand. The dyke is made of permeable tailings sand and therefore it is equipped with seepage collection ditches that are designed to collect water from drains in the dyke but also to intercept seepage water not collected by the drains and transmit it to the seepage pond for recycling. The effectiveness of this seepage collection system was examined at the downgradient end of the tailings pond (Study Area) where near-surface permeable sand is present. <br /><br /> Piezometric level measurements were performed and water samples were collected from a network of 21 piezometers and drive points, and at several other critical locations. Concentrations of major chemical tracers of PAW such as naphthenic acids (NAs) show signs of migration of PAW in the permeable sand deposit, beyond the dyke. This interpretation is supported by stable O and H isotope analysis of water. The interpretation of the piezometric and chemical data revealed that the PAW has migrated past the Inner Ditch but not beyond the Outer Ditch. Elevated hydraulic heads beyond the Outer Ditch prevented further migration. Groundwater locally converges and discharges as surface water in the wet area between the two ditches. Thus, the collection ditch system is currently working effectively to contain PAW. <br /><br /> Numerical modeling of the Study Area was able to reasonably recreate the observed hydraulic conditions. Based on these simulations, it is possible that PAW may be migrating through a permeable layer of sand under the bottom of the dyke and pond, and eventually discharging into the wet area between the ditches. The estimated amount of PAW seepage discharged into the wet area is small compared to the total dyke drainage collected by the ditches. <br /><br /> These conditions described above, however, may change with the progress of the current dyke expansion work. The wet area between the ditches will be buried and the local hydraulic condition is expected to alter. This may reverse the hydraulic gradient across the Outer Ditch and perhaps will facilitate migration of PAW beyond the Outer Ditch. It is recommended that the following key chemical parameters be used in future groundwater quality monitoring efforts to track PAW migration at the Muskeg River Mine: Na⁺ Cl^- , SO₄^2- , and Ca²⁺ ions, stable isotopes of hydrogen and oxygen, and Naphthenic acids (NAs. )

Oil sands mining operations in northeastern Alberta are rapidly expanding. Upgrading and extracting the bitumen from the sand requires large volumes of water generating large quantities of oil sands process water/materials (OSPM) which is high in organic content. Some of the major organic components found in OSPM include unrecovered bitumen, polycyclic aromatic compounds (PACs), naphthenic acids (NAs) and humic acids. Concerns of acute and chronic toxicity resulting from OSPM have led to provincial legislation preventing the discharge of OSPM into local water and mandating the reclamation of areas affected by oil sands mining. To date, OSPM is stored on lease in settling basins while the mining companies evaluate reclamation strategies. One of the reclamation strategies involves the use of wetlands constructed with differing amounts of OSPM and organic amendments such as peat. Currently, numerous wetlands, both natural and constructed, are present on oil sands leases. To determine the sustainability of these wetlands for reclamation, the assimilation and flow of carbon and nitrogen within the systems need to be defined. Stable isotope analysis can enhance this understanding. To effectively use stable isotopes in the field, there is the need to determine the changes in stable isotope values occurring from the microbial degradation of organic components such as NAs which contribute a significant portion to the dissolved organic carbon (DOC) in reclamation sites. This study examined the microbial degradation of commercial and oil sands derived NAs by oil sands derived microbial cultures. Changes in stable isotopes values in the biomass (δ13C, δ15N), DOC and dissolved inorganic carbon (DIC) (δ13C) arising from degradation of the DOC were tracked in both static and semi-continuous tests. Utilization of commercial and oil sands derived NAs resulted in minimal change of the DOC stable isotope values. The biomass was 13C enriched for both the commercial (0.3 to 2.9 per mil (‰)) and oil sands derived NAs (3.7 to 8.5 ‰) relative to the DOC stable isotope values. DIC stable isotope values showed higher variability (-5 to +5.5 ‰). The semi-continuous tests showed biomass that was 15N enriched (3.8 to 8.4 ‰) with the assimilation of ammonium. Isotope trends established in the laboratory study provide further understanding into assimilation of carbon and nitrogen compounds in the field. DOC and DIC concentration and carbon stable isotope values were determined for water sampled from 13 oil sands aquatic reclamation sites varying in age, construction and organic material. Both DOC and DIC concentrations were elevated in OSPM affected sites, by an average of 40 mg/L for DOC and 83 mg/L for DIC concentrations. DOC concentrations were also elevated by approximately 10 mg/L at high organic sites. δ13C DOC values were slightly 13C enriched in young sites: 0.6 ‰ compared to δ13C DOC values at the mature sites. Also, from June to July 13C enrichment (0.3 to 1.9 ‰) of the DOC for all sites was seen. Corresponding with the enrichment seen in the DOC, 13C depletion (-8.8 to -0.3 ‰) of the DIC was seen for most sites from June to July. The trends seen from June to July may be a result of the release of readily degradable organics from the spring thaw stimulating the microbial community. The baseline values determined for DOC and DIC may assist future field food web studies.

Systems methodologies are employed to investigate strategic decision problems regarding the development of the oil sands in Canada. Many countries believe energy to be one of their most important national security factors in today’s competitive global era. Canada is no exception. Energy is an issue in Canadians’ growing concerns related to the conflicting priorities of its economy, environment, and society. Various studies have tried to map out Canada’s establishment as an energy superpower. In particular, the massive resources in Canada must be considered as competitive advantages, and oil sands (tar sands) constitute one of the most crucial elements in terms of non-renewable energy. This thesis describes Canada’s oil sands – their characteristics, cost and market analysis, as well as social, economic, and environmental impacts – in order to clarify conflicts that have arisen in recent years. In addition, the importance, potential, and constraints of the oil sands are examined as leading drivers to the country becoming an energy superpower and are compared with the Canadian Academy of Engineering (CAE)’s studies and recommendations. Multiple-criteria decision analyses based on the ProGrid methodology are carried out at different levels to clarify the structure and current position of Canada’s energy system. An Evaluation Matrix, including multiple criteria, is built, and language ladders with different weights are established to allow various groups of experts to evaluate available options. Based on their evaluations, the strong and weak points of the oil sands are analyzed. At a more detailed level, alternative solutions for water quantity and quality problems in Canada’s oil sands are prioritized with respect to specific criteria, using the ProGrid methodology. The strategic issues in Canada’s oil sands are addressed at different levels, and priorities for decision-making are determined and discussed to guide Canada in becoming an energy superpower.

Elemental sulphur (S⁰) is removed from sour gas deposits (high H₂S) during refinement. The resulting S⁰ is often stored onsite when the costs of shipping S⁰ to market exceeds the costs of storing it in large above ground blocks. With the aid of acidiphilic bacteria, atmospheric air and water oxidize S⁰ to sulphate (SO₄^2-). Long term storage is under consideration; however, oxidation rates and the role of each oxygen source (O_2(g) and H₂O) is not clear. S⁰ oxidation experiments were conducted over a range of temperatures (6-32¡ãC) to investigate reaction rates and isotopic fractionation of O and S isotopes during oxidation. The experiments also investigated the effect of integrating S⁰ oxidizing microorganisms and available nutrients on both the reaction rates and isotope fractionation. Results indicated > 95% of total SO₄^2- generated can be attributed to autotrophic microbial activity. Experiments conducted in a nutrient rich mineral solution showed rates increase with temperature from 0.16 (6¡ãC) to 0.98 (32¡ãC) ¦Ìg S⁰ cm^-2 d^-1 (Q₁₀ ¡Ö 1.7 - 1.9). Experiments conducted in a nutrient poor solution (deionized water) showed oxidation rates did not increase with temperature (0.06 to 0.08 ¦Ìg S⁰ cm^-2 d^-1) between 12 and 32¡ãC. Oxygen isotope analysis of the generated SO₄^2- indicated essentially all oxygen incorporated into the SO₄^2- originated from H₂O. In addition, effluent samples obtained from S⁰ block effluent at SCL indicated ¦Ä¹⁸O_(SO4) generally reflected the ¦Ä¹⁸O_(H2O) in the system at the time of oxidation. While covering the S⁰ blocks with an impermeable cover would undoubtedly minimize total SO₄^2- accumulation in block effluent, the results of this study suggest ¦Ä¹⁸O_(SO4) can also be used to track water movement through the block.

Thesis--University of Michigan. / Includes bibliographical references (vol. 1, leaves 408-421).