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Oil Sands Environmental Management Bibliography

The Cumulative Environmental Management Association (CEMA)partnered with the Oil Sands Research and Information Network (OSRIN) to create the new Oil Sands Environmental Management Bibliography, which includes documents relevant to the environmental management of oil sands development in Alberta. The majority of the documents focus on the mineable oil sands in the Athabasca deposit, though some documents relate to in-situ developments. This bibliography was last updated in November 2014.

Microbial communities in organic substrates used for oil sands reclamation and their link to boreal seedling growth

Authors Beasse, M. L.
Year of Publication: 2012

Citation:
Beasse, M. L. (2012).  Microbial communities in organic substrates used for oil sands reclamation and their link to boreal seedling growth. 97 pages .
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Microbial communities in wetlands of the Athabasca oil sands: Genetic and metabolic characterization

Authors Hadwin, A. K. M.
Year of Publication: 2004

Abstract:
Naphthenic acids are a complex family of naturally occurring cyclic and acyclic carboxylic acids that are present in the acidic fraction of petroleum. Naphthenic acids are acutely toxic to aquatic organisms. Previous studies showed that wetland sediments exposed to oil sands process water containing naphthenic acids had higher rates of naphthenic acid degradation in vitro compared with unexposed wetlands. In this study we compare the microbial community structures in sediments from wetlands exposed to different amounts of oil sands process water using BIOLOG, phospholipid fatty acid analysis and denaturing gradient gel electrophoresis of total bacterial DNA. Community profiles were compared using cluster analysis. BIOLOG profiles were primarily influenced by seasonal trends rather than naphthenic acids content. In contrast, phospholipid fatty acid analysis comparisons clustered communities that had higher levels of residual oil, although this association was not strong. In contrast, cluster diagrams produced from the denaturing gradient gel electrophoresis data clearly separated bacterial communities according to naphthenic acids concentrations, indicating that naphthenic acids content was a major influence on the composition of the bacterial community. In addition, denaturing gradient gel electrophoresis profiles indicated that naphthenic acids-exposed bacterial communities were homogeneous on a scale of meters, whereas unexposed (off-site) wetlands were less homogeneous.

Citation:
Hadwin, A. K. M. (2004).  Microbial communities in wetlands of the Athabasca oil sands: Genetic and metabolic characterization. 173 pages . Abstract
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Microbial communities in wetlands of the Athabasca oil sands: Genetic and metabolic characterization

Authors Hadwin, A. K. M., Del Rio L. F., Pinto L. J., Painter M., Routledge R., & Moore M. M.
Year of Publication: 2006

Abstract:
Naphthenic acids are a complex family of naturally occurring cyclic and acyclic carboxylic acids that are present in the acidic fraction of petroleum. Naphthenic acids are acutely toxic to aquatic organisms. Previous studies showed that wetland sediments exposed to oil sands process water containing naphthenic acids had higher rates of naphthenic acid degradation in vitro compared with unexposed wetlands. In this study we compare the microbial community structures in sediments from wetlands exposed to different amounts of oil sands process water using BIOLOG, phospholipid fatty acid analysis and denaturing gradient gel electrophoresis of total bacterial DNA. Community profiles were compared using cluster analysis. BIOLOG profiles were primarily influenced by seasonal trends rather than naphthenic acids content. In contrast, phospholipid fatty acid analysis comparisons clustered communities that had higher levels of residual oil, although this association was not strong. In contrast, cluster diagrams produced from the denaturing gradient gel electrophoresis data clearly separated bacterial communities according to naphthenic acids concentrations, indicating that naphthenic acids content was a major influence on the composition of the bacterial community. In addition, denaturing gradient gel electrophoresis profiles indicated that naphthenic acids-exposed bacterial communities were homogeneous on a scale of meters, whereas unexposed (off-site) wetlands were less homogeneous.

Citation:
Hadwin, A. K. M., Del Rio L. F., Pinto L. J., Painter M., Routledge R., & Moore M. M. (2006).  Microbial communities in wetlands of the Athabasca oil sands: Genetic and metabolic characterization. 55(1), 10 pages . Abstract
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Microbial communities involved in methane production from hydrocarbons in oil sands tailings

Authors Siddique, T., Penner T., Klassen J., Nesbo C., & Foght J. M.
Year of Publication: 2012

Abstract:
Microbial metabolism of residual hydrocarbons, primarily short-chain n-alkanes and certain monoaromatic hydrocarbons, in oil sands tailings ponds produces large volumes of CH4 in situ. We characterized the microbial communities involved in methanogenic biodegradation of whole naphtha (a bitumen extraction solvent) and its short-chain n-alkane (C6–C10) and BTEX (benzene, toluene, ethylbenzene, and xylenes) components using primary enrichment cultures derived from oil sands tailings. Clone libraries of bacterial 16S rRNA genes amplified from these enrichments showed increased proportions of two orders of Bacteria: Clostridiales and Syntrophobacterales, with Desulfotomaculum and Syntrophus/Smithella as the closest named relatives, respectively. In parallel archaeal clone libraries, sequences affiliated with cultivated acetoclastic methanogens (Methanosaetaceae) were enriched in cultures amended with n-alkanes, whereas hydrogenotrophic methanogens (Methanomicrobiales) were enriched with BTEX. Naphtha-amended cultures harbored a blend of these two archaeal communities. The results imply syntrophic oxidation of hydrocarbons in oil sands tailings, with the activities of different carbon flow pathways to CH4 being influenced by the primary hydrocarbon substrate. These results have implications for predicting greenhouse gas emissions from oil sands tailings repositories.

Citation:
Siddique, T., Penner T., Klassen J., Nesbo C., & Foght J. M. (2012).  Microbial communities involved in methane production from hydrocarbons in oil sands tailings. 46(17), 8 pages . Abstract
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Microbial community structure and nutrient availability in oil sands reclaimed boreal soils

Authors MacKenzie, D. M., & Quideau S. A.
Year of Publication: 2010

Abstract:
Alberta has one of the largest oil reserves in the world, some of which is extracted by surface mining representing a large scale disturbance to forest soils. We examined ecosystem function in reclaimed soils by measuring microbial community structure with phospholipid fatty acid (PLFA) analysis and nutrient availability with plant root simulator (PRS™) probes. Samples were taken from three slope positions, at three sites, on three dates (June and August 2005, and August 2006), and non-metric multi-dimensional scaling ordination was used to examine trends in the data. Repeated measures ANOVA was used to examine trends over time in key response variables identified by ordination. Ordination results revealed distinct differences between the spring and summer microbial community structure across sites, although large site differences were also found between fall measurements in the two consecutive years. Total microbial biomass (TMB) and the fungal to bacterial ratio (FBR) emerged as key response variables for microbial community structure, and repeated measures ANOVA indicated significant site differences for these parameters. Soil nutrient availability was predominantly affected by site, but was also greatly affected by season and by year of sampling. The key response variables for nutrient availability were NH4+ and NO3−, which also varied significantly by site and season, with high NH4+ availability in the spring on vegetated/fertilized sites and high NO3− availability year round on the non-vegetated site. Slope position had an inconsistent effect on the measured parameters which may indicate that these reclaimed soils are not characterized by near surface lateral flow. Seasonal fluctuations in nitrogen and boron availability, reflected in microbial community PLFA profiles, point at possible mechanistic linkages between the functioning of microbial communities and soil mineral nutrient availability.

Citation:
MacKenzie, D. M., & Quideau S. A. (2010).  Microbial community structure and nutrient availability in oil sands reclaimed boreal soils. 44(1), 9 pages . Abstract
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Microbial community structure and operational performance of a fluidized bed biofilm reactor treating oil sands process-affected water

Authors Islam, M. S., Dong T., Sheng Z., Liu Y., & El-Din M. G.
Year of Publication: 2014

Abstract:
This study evaluated the treatment of oil sands process-affected water (OSPW) using a fluidized bed biofilm reactor (FBBR) with granular activated carbon (GAC) as support media. The bioreactor was operated for 120 days at different organic and hydraulic loading rates. The combined GAC adsorption and biodegradation process removed 51% of chemical oxygen demand (COD), 56% of acid-extractable fraction (AEF) and 96% of classical naphthenic acids (NAs) under optimized operational conditions. Bioreactor treatment efficiencies were dependent on the organic loading rate (OLR), and to a lower degree, on the hydraulic loading rate (HLR). Further ultra performance liquid chromatography/high resolution mass spectroscopy (UPLC/HRMS) analysis showed that the removal of classical NAs increased as the carbon number increased. Compared with planktonic bacterial community in OSPW, more diverse microbial structures were found in biofilms colonized on the surface of GAC after 120-day treatment, with various carbon degraders namely Polaromonas jejuensis, Algoriphagus sp., Chelatococcus sp. and Methylobacterium fujisawaense in the GAC-biofilm reactor. The results of this study, therefore, showed that the GAC-biofilm seems to be a promising biological treatment method for OSPW remediation.

Citation:
Islam, M. S., Dong T., Sheng Z., Liu Y., & El-Din M. G. (2014).  Microbial community structure and operational performance of a fluidized bed biofilm reactor treating oil sands process-affected water. 91, 7 pages . Abstract
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Microbial content and metabolic activities in the Syncrude tailings pond

Authors Foght, J. M., Fedorak P. M., Westlake D. W. S., & Boerger H. J.
Year of Publication: 1985

Citation:
Foght, J. M., Fedorak P. M., Westlake D. W. S., & Boerger H. J. (1985).  Microbial content and metabolic activities in the Syncrude tailings pond. 1(2), 7 pages .
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Microbial populations in the Athabasca River

Authors Costerton, J. W., & Geesey G. G.
Year of Publication: 1979

Abstract:
The direct epifluorescence method has been adapted for counting bacteria in the sometimes turbid water of the Athabasca River and this method has been used to quantify planktonic bacteria. Monthly samples over an annual cycle beginning in May 1976 showed this population ranged from 1 x 105 to 2 x 106 cells per millilitre. A statistical analysis of site-to-site variations and averages of bacterial numbers from sites upstream and downstream from Fort McMurray and the GCOS plant site have shown there is no discernible effect on the bacterial populations by either facility. Further, there is a definite site-to-site variation in the bacterial numbers as well as seasonal variations at each site. The direct microscopic examination, including scanning electron microscopy, has shown that the planktonic bacteria are generally free-floating with some colonization of organic detrital materials. Silt particles are generally free of bacteria. The statistical analysis of the ATP measurement showed that this method for estimation of bacterial biomass could not be used in the Athabasca. When bacterial enumeration data were compared to flow, total organic carbon, nitrogen (Kjeldahl), and conductivity, there was no correlation. However there was a slight negative correlation of bacterial numbers with turbidity and total unfilterable residue.

Citation:
Costerton, J. W., & Geesey G. G. (1979).  Microbial populations in the Athabasca River. 66 pages . Abstract
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Microbial reduction of amended sulfate in anaerobic mature fine tailings from oil sand

Authors Salloum, M. J., Dudas M. J., & Fedorak P. M.
Year of Publication: 2002

Abstract:
Bitumen extraction from oil sands has resulted in large tailings ponds, containing suspended material that requires over one hundred years to densify. The mature fine tailings (MFT) have become anaerobic and bubbles of gas are observed on the pond surface. Gypsum has been proposed as an additive to increase the rate of MFT consolidation. In a laboratory study, MFT was amended with sulfate and monitored. Pore water sulfate concentrations declined and bicarbonate concentration increased. Nitrate was depleted within 36 d and the levels of soluble iron remained below 0.8 mg L(-1). Thiosulfate and sulfide were detected only near the end of the experiment. Acid volatile sulfides (AVS) increased until day 39, and then reached a plateau. Methane was not detected throughout the incubation in samples amended with sulfate. The increase in AVS supports sulfide incorporation into the solid phase, however, the plateau after 39 d suggests a secondary fate of reduced sulfide.

Citation:
Salloum, M. J., Dudas M. J., & Fedorak P. M. (2002).  Microbial reduction of amended sulfate in anaerobic mature fine tailings from oil sand. 20(2), 9 pages . Abstract
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Microbial response to fertilization in contrasting soil materials used during oil sands reclamation

Authors Quideau, S. A., Gupta S. D., MacKenzie D. M., & Landhausser S. M.
Year of Publication: 2012

Abstract:
Reclamation practices following open-pit mining typically include the reconstruction of soil-like profiles using a combination of native soil materials, industrial by-products, and fertilizers. Our overall objective was to compare the quality of eight soil materials used during reclamation in the Athabasca oil sands region of western Canada by characterizing their microbial communities as well as their response to a range of fertilization treatments. Materials included two carbon-rich surface soil materials, four B horizons with varying extractable phosphorus and pH, the parent geological material (PGM), and tailings sands (TSS), a by-product of oil extraction. Measured indices of microbial activity included the activities of b-glucosidase, acid phosphatase, and phenol oxidase. Total biomass and structure of the soil microbial community were characterized based on phospholipid fatty acid (PLFA) analysis. Soil materials and fertilization treatments were tested with multivariate regression trees and non-metric multidimensional scaling. Material type, rather than fertilization level, had the largest impact on all microbial parameters, including biomass, activity, and composition. Only the nutrient-poor materials (PGM, TSS, and one of the B horizons) showed a response to fertilization. The microbial composition of three of the four B horizons was more similar to the two carbon-rich surface soil materials than it was to PGM or TSS. Hence, we propose that these subsoil materials present an advantage over the use of the underlying PGM when reconstructing upland sandy soils. Finally, results indicated that soil microbial biomass could be used as a good indicator of seedling growth when no fertilizer was applied.

Citation:
Quideau, S. A., Gupta S. D., MacKenzie D. M., & Landhausser S. M. (2012).  Microbial response to fertilization in contrasting soil materials used during oil sands reclamation. 77(1), 9 pages . Abstract
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Microbial S biogeochemistry of oil sands composite tailings

Authors Warren, L. A., Kendrake K. E., Reid M. L., & Colenbrander Nelson T.
Year of Publication: 2014

Abstract:
Oil sands tailings are important, globally relevant, S reservoirs, known to contain active and diverse microbial communities. However, the potential for S bigeochemical cycling occurring within composite tailings (CT), a mixture of fluid fine tailings, post-processed sand and gypsum (flocculant) used in dry reclamation approaches, has not been examined prior to this study. Biogeochemical characterization of CT solid and porewater samples taken from 5 depths over a 40 meter CT deposit (Mildred Lake, Syncrude Ltd, Fort McMurray, AB, CANADA) revealed distinct depth dependent zones of surficial iron reducing and more extensive sulphate reducing microbial activity. Porewater H2S was detected below 6 meters in the deposit ranging in concentration from 14–300 µM, while much lower concentrations, 1-40 µM, of porewater Fe2+ were restricted to surficial CT samples. Metagenomic (454 pyrosequencing) characterization revealed highly diverse CT microbial communities, with 21 different phyla encountered overall. However, consistent with the porewater geochemical profiles, two depth dependent, structurally distinct communities emerged from multivariate statistical analyses of phylogenetic data (UniFrac http://bmf.colorado.edu/unifrac): a surficial CT zone of Fe3+ reduction and an underlying, more extensive zone of SO42- reduction. These microbial zones were linked to DOC, redox and salinity conditions within the CT deposit. Consistent with the notion that accessible organic carbon was limiting IRB and SRB activity, available SO42- and Fe3+ sources were evident and abundant throughout the deposit. Pilot reclamation is currently focusing on capping CT with a freshwater wetland, reflecting the original boreal forest landscape. However a wetland may provide a more labile organic carbon source for underlying CT associated bacteria, which may stimulate greater H2S generation and/or aid sequestration through IRB driven FeS formation. Recent field and laboratory results from the adjacent CT pilot fen reclamation site suggest that stimulation of H2S generation associated with downwelling fen organic carbon inputs is occurring. These results identify the need to consider the potential for microbial biogeochemical transformations of waste materials to hinder the efficacy of proposed reclamation scenarios.

Citation:
Warren, L. A., Kendrake K. E., Reid M. L., & Colenbrander Nelson T. (2014).  Microbial S biogeochemistry of oil sands composite tailings. Abstract
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Microbial sulfur biogeochemistry of oil sands composite tailings with depth

Authors Kendra, K. E.
Year of Publication: 2013

Abstract:
Surface mining of Alberta’s oil sands has led to significant land disturbance, making reclamation and sustainable development of this resource one of the largest challenges facing the industry today. Syncrude Canada Ltd. has developed an innovative technique to reclaim composite tailings (CT) through constructed wetland landscapes and is currently investigating the viability of a pilot-scale freshwater fen built over sandcapped CT. Unpredicted by abiotic geochemical modelling of CT behaviour, a minor episode of hydrogen sulfide (H2S) gas release was encountered during the initial stages of fen construction indicating microbial activity was likely involved in H2S generation within CT. This thesis investigates the S geochemistry of CT with depth and employed 454 pyrosequencing and functional enrichments to characterize the associated microbial communities in the first S biogeochemical study of oil sands CT. Porewater H2S was detected extensively throughout the deposit with background levels ranging from 14 – 23 μM and a maximum of 301.5 μM detected at 22-24 m of depth. Reduced Fe (Fe2+) was also detected, but confined within surficial depths sampled, ranging from 1.2 – 38.5 μM. Mass balance calculations identify that the Fe2+ generated within the surficial zone of the CT deposit is sufficient to effectively sequester ambient concentrations H2S generated in this deposit through FeS precipitates. Results identifying (1) distinct zones of porewater Fe2+ and H2S, (2) co- occurrence of the highest [H2S] and lowest dissolved organic C (DOC) at 22-24 m consistent with heterotrophic sulfate reducing bacteria (SRB) activity, and (3) the presence of mixed valence Fe biomineral, magnetite, throughout the deposit, are all consistent with microbially- mediated Fe and S cycling occurring within this CT deposit. The cultivation independent identification of several known iron reducing bacteria (IRB) and SRB within CT microbial communities, in conjunction with observed positive growth of IRB and SRB functional iv M.Sc. Thesis – K.E. Kendra; McMaster University – Earth and Environmental Sciences metabolic enrichments, demonstrates widespread capacity for microbial Fe and S activity throughout the CT deposit. Metagenomic characterization of CT microbial communities revealed high diversity (over 20 phyla) over the 5 depths examined. Multivariate statistical analyses (Unifrac) revealed that bacterial community composition and structure was driven by changed in DOC, ORP and salinity and that structuring corresponded with a surficial zone of Fe3+ reduction and an underlying zone of SO42- reduction. Despite the high organic carbon (OC) content of oil sands tailings, much of that C is not considered to be labile and accessible to microbes. Based on the results of this thesis, CT SRB appear to have a greater ability than IRB to utilize recalcitrant OC (e.g. bitumen, naphthenic acids) given the widespread occurrence of porewater [H2S] and surficially restricted [Fe2+] despite accessible pools of Fe3+ and OC with depth. This enhanced understanding of biogeochemical S cycling within CT newly establishes the importance of microbial activity in these processes, identifying the need to incorporate microbially based understanding into on-going development of reclamation strategies in order to manage these waste materials effectively.

Citation:
Kendra, K. E. (2013).  Microbial sulfur biogeochemistry of oil sands composite tailings with depth. 72 pages . Abstract
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Microbially-accelerated consolidation of oil sands tailings. Pathway I: Changes in porewater chemistry

Authors Siddique, T., Kuznetsov P., Kuznetsova A., Arkell N., Young R., Li C., et al.
Year of Publication: 2014

Abstract:
Dispersed clay particles in mine tailings and soft sediments remain suspended for decades, hindering consolidation and challenging effective management of these aqueous slurries. Current geotechnical engineering models of self-weight consolidation of tailings do not consider microbial contribution to sediment behavior, however, here we show that microorganisms indigenous to oil sands tailings change the porewater chemistry and accelerate consolidation of oil sands tailings. A companion paper describes the role of microbes in alteration of clay chemistry in tailings. Microbial metabolism in mature fine tailings (MFT) amended with an organic substrate (hydrolyzed canola meal) produced methane (CH4) and carbon dioxide (CO2). Dissolution of biogenic CO2 lowered the pH of amended MFT to pH 6.4 vs. unamended MFT (pH 7.7). About 12% more porewater was recovered from amended than unamended MFT during 2 months of active microbial metabolism, concomitant with consolidation of tailings. The lower pH in amended MFT dissolved carbonate minerals, thereby releasing divalent cations including calcium (Ca2+) and magnesium (Mg2+) and increasing bicarbonate (HCO−3) in porewater. The higher concentrations increased the ionic strength of the porewater, in turn reducing the thickness of the diffuse double layer (DDL) of clay particles by reducing the surface charge potential (repulsive forces) of the clay particles. The combination of these processes accelerated consolidation of oil sands tailings. In addition, ebullition of biogenic gases created transient physical channels for release of porewater. In contrast, saturating the MFT with non-biogenic CO2 had little effect on consolidation. These results have significant implications for management and reclamation of oil sands tailings ponds and broad importance in anaerobic environments such as contaminated harbors and estuaries containing soft sediments rich in clays and organics.

Citation:
Siddique, T., Kuznetsov P., Kuznetsova A., Arkell N., Young R., Li C., et al. (2014).  Microbially-accelerated consolidation of oil sands tailings. Pathway I: Changes in porewater chemistry. 5(106),  Abstract
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Microbially-accelerated consolidation of oil sands tailings. Pathway II: Solid phase biogeochemistry

Authors Siddique, T., Kuznetsov P., Kuznetsova A., Arocena J. M., Young R., Li C., et al.
Year of Publication: 2014

Abstract:
Consolidation of clay particles in aqueous tailings suspensions is a major obstacle to effective management of oil sands tailings ponds in northern Alberta, Canada. We have observed that microorganisms indigenous to the tailings ponds accelerate consolidation of mature fine tailings (MFT) during active metabolism by using two biogeochemical pathways. In Pathway I, microbes alter porewater chemistry to indirectly increase consolidation of MFT. Here, we describe Pathway II comprising significant, direct and complementary biogeochemical reactions with MFT mineral surfaces. An anaerobic microbial community comprising Bacteria (predominantly Clostridiales, Synergistaceae, and Desulfobulbaceae) and Archaea (Methanolinea/Methanoregula and Methanosaeta) transformed Fe(III) minerals in MFT to amorphous Fe(II) minerals during methanogenic metabolism of an added organic substrate. Synchrotron analyses suggested that ferrihydrite (5Fe2O3. 9H2O) and goethite (α-FeOOH) were the dominant Fe(III) minerals in MFT. The formation of amorphous iron sulfide (FeS) and possibly green rust entrapped and masked electronegative clay surfaces in amended MFT. Both Pathways I and II reduced the surface charge potential (repulsive forces) of the clay particles in MFT, which aided aggregation of clays and formation of networks of pores, as visualized using cryo-scanning electron microscopy (SEM). These reactions facilitated the egress of porewater from MFT and increased consolidation of tailings solids. These results have large-scale implications for management and reclamation of oil sands tailings ponds, a burgeoning environmental issue for the public and government regulators

Citation:
Siddique, T., Kuznetsov P., Kuznetsova A., Arocena J. M., Young R., Li C., et al. (2014).  Microbially-accelerated consolidation of oil sands tailings. Pathway II: Solid phase biogeochemistry. 5, Abstract
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Microbially-mediated fugitive gas production from oil sands tailings and increased tailings densification rates

Authors Fedorak, P. M., Coy D. L., Dudas M. J., Simpson M. J., Renneberg A. J., & MacKinnon M. D.
Year of Publication: 2003

Abstract:
Oil sands in northeastern Alberta, Canada, are strip mined and bitumen is separated from sand and clay by an alkaline hot water extraction process leaving millions of cubic metres of tailings for disposal. These include mature fine tailings (MFT) collected in settling ponds and consolidated or composite tailings (CT) that are produced by the addition of sand and gypsum to hasten dewatering and densification. This laboratory investigation monitored the potential for fugitive gas production in 0.9-m high columns that contained MFT or CT samples from three oil sands companies. Methane was found in columns that contained aged MFT, but not in those that contained fresh MFT. Dissolved or entrapped methane was found in columns containing each of the MFT samples and two of the CT samples. Ethylene was detected in columns containing MFT or CT. This may affect future plans to re-vegetate disturbed areas of the oil sands operations because ethylene strongly influences many phases of plant development. The densification rate of a methanogenic MFT was faster than that of a nonmethanogenic MFT that was placed in a similar column 6 years prior to the start of this investigation, suggesting that methane formation may increase the rate of densification. Key words: consolidated tailings, composite tailings, densification, ethylene, methane, methanogens, oil sands, sulfate-reducing bacteria.

Citation:
Fedorak, P. M., Coy D. L., Dudas M. J., Simpson M. J., Renneberg A. J., & MacKinnon M. D. (2003).  Microbially-mediated fugitive gas production from oil sands tailings and increased tailings densification rates. 2(3), 12 pages . Abstract
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Microbiological evaluation of legume innoculants for oil sands reclamation

Authors Dai, T. S., Page W. J., & Fessenden R. J.
Year of Publication: 1982

Citation:
Dai, T. S., Page W. J., & Fessenden R. J. (1982).  Microbiological evaluation of legume innoculants for oil sands reclamation. 13 pages .
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Microbiological studies of polyacrylamide as a flocculant aid for oil sands tailings

Authors Haveroen, M. E.
Year of Publication: 2005

Abstract:
Polyacrylamide was tested as a flocculation aid by Syncrude Canada Ltd. because of its effectiveness in flocculating tailings without elevating salt concentrations. Residual acrylamide at low concentrations in polyacrylamide formulations has raised environmental concerns, because acrylamide has been considered to be toxic. This study investigated the activities of oil sands microbial consortia in the presence of polyacrylamide or acrylamide under sulfate-reducing or methanogenic conditions in laboratory microcosms. Low concentrations of acrylamide were degraded under aerobic, sulfate-reducing, methanogenic, and simulated environmental conditions by several environmental microbial consortia. Acrylamide at higher concentrations stimulated methanogenesis after an acclimation period. When supplied as a nitrogen source, polyacrylamide significantly enhanced methanogenesis, but under sulfate-reducing conditions, no conclusions could be drawn about polyacrylamide use as a nitrogen source. Acrylamide does not persist under any of the conditions tested in this study, and so likely would not pose an environmental risk when present in oil sands tailings.

Citation:
Haveroen, M. E. (2005).  Microbiological studies of polyacrylamide as a flocculant aid for oil sands tailings. 150 pages . Abstract
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Microbiology of a northern river: Bacterial distribution and relationship to suspended sediment and organic carbon

Authors Geesey, G. G., & Costerton J. W.
Year of Publication: 1979

Abstract:
Epifluorescent microscopy showed as many as 4 × 106 bacteria/mL in the turbid waters of the Athabasca River near the tar sand deposits in northeastern Alberta. The numbers were usually similar upstream and downstream (60 km) from pilot-mining operations. The majority of bacteria existed as free-living cells in spite of the fact there were high concentrations of suspended sediment present (average 220 mg/L) during the ice-free period. Fluctuations in bacterial concentration were positively correlated (r = 0.86, P < 0.05) with total organic carbon concentrations in the river water.

Citation:
Geesey, G. G., & Costerton J. W. (1979).  Microbiology of a northern river: Bacterial distribution and relationship to suspended sediment and organic carbon. 25(9 ), 4 pages . Abstract
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Microcosm assessment of the biogeochemical development of sulfur and oxygen in oil sands fluid fine tailings

Authors Chen, M., Walshe G., Chi Fru E., Ciborowsk J. J. H., & Weisener C. G.
Year of Publication: 2013

Abstract:
Bitumen recovery from Alberta oil sands generates fluid fine tailings, which are retained in tailings ponds where solids settle and release process water. The recovered water is recycled for bitumen extraction, while the resulting tailings are incorporated into various landforms for reclamation, with one option being conversion of tailings basins to viable end pit lakes. Tailings ponds commonly host diverse microbial communities, including SO4-reducing prokaryotes. The highly reducing nature of the hydrogen sulfide produced by these prokaryotes may impact the biogeochemical cycling of key nutrients. However, the behavioral dynamics of hydrogen sulfide production in ponds containing fluid fine tailings remain to be clearly explained. In this study, microcosms are used as analogues of the sediment–water interface of a tailings pond undergoing reclamation to determine sulfide generation patterns and the behavior of O2. In the microcosms, hydrogen sulfide fluxes correlated positively with biotic activity, reaching levels of over 2 × 103 nmol cm−2 s−1, leading to Fe sulfide formation. Depth-related hydrogen sulfide profiles in the microcosms were comparable to those encountered in situ, in Syncrude’s West In-Pit, an active tailing pond. Oxygen diffusion across the fluid fine tailing sediment–water interface was controlled to different degrees by both biotic and abiotic processes. The results have implications for quantitatively estimating the impact of hydrogen sulfide production, O2 availability, and biogeochemical cycling of key nutrients important for the success of life in fluid fine tailings-affected ecosystems. This paper shows that this production of hydrogen sulfide may be a self-limiting process, which will begin to decrease after a period of time.

Citation:
Chen, M., Walshe G., Chi Fru E., Ciborowsk J. J. H., & Weisener C. G. (2013).  Microcosm assessment of the biogeochemical development of sulfur and oxygen in oil sands fluid fine tailings. 37, 10 pages . Abstract
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Microcosm evaluation of community level physiological profiling in oil sands process affected water

Authors Davies, J., Eaton B., & Humphries D.
Year of Publication: 2012

Abstract:
A microcosm-based experiment was conducted to investigate the ability of community level physiological profiling (CLPP) to detect changes in an aquatic microbial community resulting from exposure to oil sands process affected water (OSPW). Detection of the microbial response was done by using the Biolog EcoPlate system, a commercially-available system originally developed for the assessment of rhizosphere microbial communities. The Biolog system consists of a 96-well microtitre plate. Each well on the plate contains both a pure organic compound (the substrate), and a tetrazolium dye. When a microorganism metabolizes the substrate, the dye is reduced into a purple formazan product. The purple colour of each well is characterized using a spectrophotometer measuring optical density (OD) at 590 nm. In this study, we used the EcoPlate version of the Biolog System. Reductions in metabolic activity and inoculum density were detected in the high OSPW group. Overall, indicators of microbial metabolic activity decreased over time. One of these indicators, the sum of substrate means (SSM), showed a dramatic response to weekly water changes. Low cyclicity naphthenic acids demonstrated a reduction over the first and last weeks of the exposure period. Higher cyclicity naphthenic acids demonstrated reductions in the first but not the last week of exposure. The total naphthenic acid (TNA) content of the microcosms appeared to increase over the last week of the exposure period, which may reflect the accumulation of products of microbial metabolism. Our results suggest that inoculum density remains a source of variability for CLPP results. Furthermore, the biological context under which the microbial community forms has a strong influence on its metabolic characteristics. The changes in naphthenic acid concentration (total and speciated) likely reflect adsorption and/or microbial metabolism. Our observation of increased phytoplankton in the presence of OSPW is consistent with the available literature. Additional research will be required to determine if this finding can be developed into an indicator of toxic effect, rather than just the presence/concentration of OSPW.

Citation:
Davies, J., Eaton B., & Humphries D. (2012).  Microcosm evaluation of community level physiological profiling in oil sands process affected water. 33 pages . Abstract
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Micrometeorology and microclimatology of vegetation canopy

Authors Labine, C.
Year of Publication: 1976

Citation:
Labine, C. (1976).  Micrometeorology and microclimatology of vegetation canopy. 6 pages .
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Microorganisms in oil sands tailings ponds influence the properties and behaviour of mature fine tailings (MFT)

Authors Bressler, D., Cardenas M., Fedorak P. M., Guigrd S., Gupta R., Siddique T., et al.
Year of Publication: 2010

Citation:
Bressler, D., Cardenas M., Fedorak P. M., Guigrd S., Gupta R., Siddique T., et al. (2010).  Microorganisms in oil sands tailings ponds influence the properties and behaviour of mature fine tailings (MFT). 3 pages .
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Microscopic observation of structure in oil sands sludge

Authors Mikula, R. J., Payette C., Munoz V., & Lam W. W.
Year of Publication: 1991

Abstract:
Freeze fracture preparation and subsequent direct observation of frozen hydrated samples in an electron microscope has been used to characterize the morphology and composition of oil sands sludges. A card house type of structure has long been suggested to explain the long term stability of sludge to consolidation but the relative role of organic/mineral or mineral/mineral interactions in determining the stability of the structure is not well understood. Electron microscopic techniques are discussed which might allow direct determination of the relationship between the various sludge components_ Evidence is presented which suggests that it is possible to directly observe the sludge structure.

Citation:
Mikula, R. J., Payette C., Munoz V., & Lam W. W. (1991).  Microscopic observation of structure in oil sands sludge. 9 pages . Abstract
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Microwave assisted photocatalytic treatment of naphthenic acids in water

Authors Mishra, S.
Year of Publication: 2009

Abstract:
Naphthenic acids (NAs) are natural constituents of bitumen and crude oil, and predominantly obtained as the by-product of petroleum refining with variable composition and ingredients. Naphthenic acids are composed of alkyl-substituted cycloaliphatic carboxylic acids, with smaller amounts of acyclic aliphatic acids. Naphthenic acids become a significant part of the tailings pond water (TPW) after separation from oil sands material. NAs are soluble in water and are concentrated in TPW as a result of caustic oil sands extraction processes. Tailings ponds near the Athabasca oil sands region near Fort McMurray, Alberta, Canada are contaminated with a variety of toxic organic compounds released in industrial effluent from the oil extraction processes. NAs are among the major water contaminants in those regions because of their toxicity and environmental recalcitrance. They may enter surface water systems due to erosion of riverbank oil sands deposits and through groundwater mixing. Significant environmental and regulatory attention has been focused on the naphthenic acids fraction of oil sands material to address these challenges and potential hazards. Biological, chemical, and photolytic treatments of water contaminated with NAs have been studied, but are either time consuming or involve significant capital investment. There is a growing need to develop more efficient and cost-effective treatment methods. Based on existing literature, microwave and photocatalysis for degradation of naphthenic acids in water may be one solution. A knowledge gap exists in determining the effect of microwave energy and/or photocatalysis on the rate and extent of NAs degradation in contaminated water. Part of this work included evaluation of the physical and chemical properties of NAs. Dielectric properties, important for designing a microwave system, were investigated. Effects of temperature, concentration, and frequency of microwaves on the dielectric properties of NA-water mixtures were studied and were used in designing the treatment systems for NAs. Three laboratory scale systems, (1) photocatalysis, (2) microwave, and (3) microwave assisted photocatalysis systems were designed and developed. Experiments were conducted to determine the NA degradation efficiency of these systems for both commercially available Fluka NAs and those extracted from oil sand process water (OSPW). Effects of water source (deionised and river water) and use of TiO2 catalyst in the degradation process, were also investigated. Degradation kinetics for total NAs as well as individual z-family were calculated. Results show that the three developed treatment systems were able to degrade NAs at a faster rate than the methods reported to date. The concentration of higher molecular weight NAs (z = -4 to -12) decreased more significantly than the lower molecular weight NAs in all the three treatment systems. Toxicity assessments of the NAs samples before and after treatment indicated that photocatalysis and microwave assisted photocatalysis systems decreased the toxicity of Fluka and OSPW NAs completely (up to 5 min IC50 v/v > 90%). The microwave system reduced the toxicity of water containing Fluka NAs from high (5 min IC50 v/v = 15.85%) to moderate (5 min IC50 v/v = 36.45%) toxicity. However, a slight increase in toxicity was noted post-treatment in OSPW NAs. Microwave-assisted photocatalysis was the most rapid degradation system for OSPW NA extracts in water with a half-life of 0.56 h in the presence of TiO2. The microwave system degraded OSPW NAs in water at a more moderate half-life of 3.32 h. The photocatalysis system was the slowest with a half-life of 3.99 h under similar conditions. High and ultra high resolution analysis of NA sample, estimations of cost and further efficiency related research of the developed systems to treat water with microbial load along with chemical contaminants are recommended for future work to further validate these treatment systems.

Citation:
Mishra, S. (2009).  Microwave assisted photocatalytic treatment of naphthenic acids in water. 135 pages . Abstract
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Microwave heating for adsorbents regeneration and oil sands coke activation

Authors Chen, H.
Year of Publication: 2010

Abstract:
Microwave heating has unique advantages compared to convection-radiation heating methods including fast heating rate and selective heating of objects. This thesis studied two applications of microwave heating in the environmental field: adsorbent regeneration and oil sands coke activation. The thermal behavior during microwave heating of select adsorbents when dry or saturated with selected adsorbates was studied to assess the potential for using microwave heating to regenerate adsorbents. Strong microwave-absorbing adsorbents depicted faster heating rate when dry. Weakly microwave-absorbing adsorbents depicted faster heating rate when saturated with polar adsorbates. Fast activation of oil sands coke using microwave heating and KOH was successfully completed. The iodine number of the activated delayed coke obtained after 10 minutes of microwave activation was 1130 mg/g. The short activation time and simplicity of the process demonstrate that microwave-activation is a promising approach to convert oil sands coke into activated carbon adsorbent with high adsorption capacity.

Citation:
Chen, H. (2010).  Microwave heating for adsorbents regeneration and oil sands coke activation. 147 pages . Abstract
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