Ruminant-Waste Protein Hydrolysates and Their Derivatives as a Bio-Flocculant for Oil Sands Tailing Management

Reclamation of tailings ponds is a critical issue for the oil industry. After years of consolidation, the slurry in tailings ponds, also known as fluid fine tailings, is mainly comprised of residual bitumen, water, and fine clay particles. To reclaim the lands that these ponds occupy, separation of the solid particles from the liquid phase is necessary to facilitate water removal and recycling. Traditionally, synthetic polymers have been used as flocculants to facilitate this process, but they can have negative environmental consequences. The use of biological polymers may provide a more environmentally friendly approach to flocculation, and eventual soil remediation, due to their natural biodegradability. Peptides derived from specified risk materials (SRM), a proteinaceous waste stream derived from the rendering industry, were investigated to assess their viability for this application. While these peptides could achieve >50% settling within 3 h in bench-scale settling tests using kaolinite tailings, crosslinking peptides with glutaraldehyde greatly improved their flocculation performance, leading to a >50% settling in only 10 min. Settling experiments using materials obtained through different reactant ratios during crosslinking identified a local optimum molar reactant ratio of 1:32 (peptide amino groups to glutaraldehyde aldehyde groups), resulting in 81.6% settling after 48 h. Taken together, these data highlight the novelty of crosslinking waste-derived peptides with glutaraldehyde to generate a value-added bioflocculant with potential for tailings ponds consolidation.

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Using Specified Risk Materials-Based Peptides for Oil Sands Fluid Fine Tailings Management

Materials ◽

10.3390/ma14071582 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1582

Author(s):

Yeling Zhu ◽

Yuki Gong ◽

Heather Kaminsky ◽

Michael Chae ◽

Paolo Mussone ◽

...

Keyword(s):

Oil Sands ◽

Colloidal Stability ◽

Free Water ◽

Value Added ◽

Settling Rate ◽

Test Range ◽

Tailings Management ◽

Fine Tailings ◽

Fluid Fine Tailings ◽

Hydrolyzed Polyacrylamide

Fluid fine tailings are produced in huge quantities by Canada’s mined oil sands industry. Due to the high colloidal stability of the contained fine solids, settling of fluid fine tailings can take hundreds of years, making the entrapped water unavailable and posing challenges to public health and the environment. This study focuses on developing value-added aggregation agents from specified risk materials (SRM), a waste protein stream from slaughterhouse industries, to achieve an improved separation of fluid fine tailings into free water and solids. Settling results using synthetic kaolinite slurries demonstrated that, though not as effective as hydrolyzed polyacrylamide, a commercial flocculant, the use of SRM-derived peptides enabled a 2-3-fold faster initial settling rate than the blank control. The pH of synthetic kaolinite tailings was observed to be slightly reduced with increasing peptides dosage in the test range (10–50 kg/ton). The experiments on diluted fluid fine tailings (as a representation of real oil sands tailings) demonstrated an optimum peptides dosage of 14 kg/ton, which resulted in a 4-fold faster initial settling rate compared to the untreated tailings. Overall, this study demonstrates the novelty and feasibility of using SRM-peptides to address intractable oil sands fluid tailings.

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Next-Generation Sequencing of Microbial Communities in the Athabasca River and Its Tributaries in Relation to Oil Sands Mining Activities

Applied and Environmental Microbiology ◽

10.1128/aem.02036-12 ◽

2012 ◽

Vol 78 (21) ◽

pp. 7626-7637 ◽

Cited By ~ 151

Author(s):

Etienne Yergeau ◽

John R. Lawrence ◽

Sylvie Sanschagrin ◽

Marley J. Waiser ◽

Darren R. Korber ◽

...

Keyword(s):

Next Generation Sequencing ◽

Microbial Communities ◽

Oil Sands ◽

Ion Torrent ◽

Content Type ◽

Athabasca River ◽

Fine Tailings ◽

Oil Sands Mining ◽

Tailings Ponds ◽

Generation Sequencing

ABSTRACTThe Athabasca oil sands deposit is the largest reservoir of crude bitumen in the world. Recently, the soaring demand for oil and the availability of modern bitumen extraction technology have heightened exploitation of this reservoir and the potential unintended consequences of pollution in the Athabasca River. The main objective of the present study was to evaluate the potential impacts of oil sands mining on neighboring aquatic microbial community structure. Microbial communities were sampled from sediments in the Athabasca River and its tributaries as well as in oil sands tailings ponds. Bacterial and archaeal 16S rRNA genes were amplified and sequenced using next-generation sequencing technology (454 and Ion Torrent). Sediments were also analyzed for a variety of chemical and physical characteristics. Microbial communities in the fine tailings of the tailings ponds were strikingly distinct from those in the Athabasca River and tributary sediments. Microbial communities in sediments taken close to tailings ponds were more similar to those in the fine tailings of the tailings ponds than to the ones from sediments further away. Additionally, bacterial diversity was significantly lower in tailings pond sediments. Several taxonomic groups ofBacteriaandArchaeashowed significant correlations with the concentrations of different contaminants, highlighting their potential as bioindicators. We also extensively validated Ion Torrent sequencing in the context of environmental studies by comparing Ion Torrent and 454 data sets and by analyzing control samples.

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Linking hydrocarbon biodegradation to greenhouse gas emissions from oil sands tailings and its impact on tailings management

Canadian Journal of Soil Science ◽

10.1139/cjss-2019-0125 ◽

2020 ◽

Vol 100 (4) ◽

pp. 537-545

Author(s):

Tariq Siddique ◽

Alsu Kuznetsova

Keyword(s):

Oil Sands ◽

Solid Phase ◽

Extraction Process ◽

Hydrocarbon Biodegradation ◽

Soil Productivity ◽

Main Research ◽

Fine Tailings ◽

Oil Sands Tailings ◽

Tailings Ponds ◽

Bitumen Extraction

Microbial research for maintaining soil productivity, health, and environment as well as for ecosystem function has been one of the main research focuses in the Department of Renewable Resources (formerly Department of Soil Science) during the last 100 yr. In recent years, microbial research has been expanded to effectively reclaim disturbed land, remediate contaminated sites, and manage soft sediments such as huge volumes of oil sands tailings. This article highlights the microbial processes in tailings ponds that can affect strategies to manage growing inventory of oil sands tailings and reduce associated environmental footprint. Enormous volumes of fluid fine tailings produced during bitumen extraction from oil sands are retained in tailings ponds. Some tailings streams contain residual labile hydrocarbons originated from the hydrocarbon solvents used in the extraction process. Indigenous microorganisms acclimated to the pond environment metabolize certain fractions of the fugitive labile hydrocarbons into biogenic greenhouse gases (GHG) such as methane (CH4) and carbon dioxide (CO2). Long-term (1–7 yr) biodegradation studies conducted using mature fine tailings (MFT) collected from different tailings ponds reveal that the microorganisms sequentially and preferentially biodegrade hydrocarbons under methanogenic conditions. The stoichiometric mathematical model developed on these biodegradation studies can predict GHG emissions from tailings ponds. Production of biogenic gases also affects the porewater and solid-phase chemistry of MFT and accelerates their de-watering and consolidation during active methanogenesis, which is beneficial for recovery of porewater for reuse in the bitumen extraction process and for effective reclamation of consolidated material.

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Methanogenic Biodegradation of iso-Alkanes by Indigenous Microbes from Two Different Oil Sands Tailings Ponds

Microorganisms ◽

10.3390/microorganisms9081569 ◽

2021 ◽

Vol 9 (8) ◽

pp. 1569

Author(s):

Mohd Faidz Mohamad Shahimin ◽

Julia M. Foght ◽

Tariq Siddique

Keyword(s):

Oil Sands ◽

Carbon Chain ◽

Lag Phase ◽

Carbon Chain Length ◽

Oil Sand ◽

Degradation Pattern ◽

Fine Tailings ◽

Oil Sands Tailings ◽

Tailings Ponds ◽

Oil Sands Tailings Ponds

iso-Alkanes, a major fraction of the solvents used in bitumen extraction from oil sand ores, are slow to biodegrade in anaerobic tailings ponds. We investigated methanogenic biodegradation of iso-alkane mixtures comprising either three (2-methylbutane, 2-methylpentane, 3-methylpentane) or five (2-methylbutane, 2-methylpentane, 2-methylhexane, 2-methylheptane, 2-methyloctane) iso-alkanes representing paraffinic and naphtha solvents, respectively. Mature fine tailings (MFT) collected from two tailings ponds, having different residual solvents (paraffinic solvent in Canadian Natural Upgrading Limited (CNUL) and naphtha in Canadian Natural Resources Limited (CNRL)), were amended separately with the two mixtures and incubated in microcosms for ~1600 d. The indigenous microbes in CNUL MFT produced methane from the three-iso-alkane mixture after a lag of ~200 d, completely depleting 2-methylpentane while partially depleting 2-methylbutane and 3-methylpentane. CNRL MFT exhibited a similar degradation pattern for the three iso-alkanes after a lag phase of ~700 d, but required 1200 d before beginning to produce methane from the five-iso-alkane mixture, preferentially depleting components in the order of decreasing carbon chain length. Peptococcaceae members were key iso-alkane-degraders in both CNUL and CNRL MFT but were associated with different archaeal partners. Co-dominance of acetoclastic (Methanosaeta) and hydrogenotrophic (Methanolinea and Methanoregula) methanogens was observed in CNUL MFT during biodegradation of three-iso-alkanes whereas CNRL MFT was enriched in Methanoregula during biodegradation of three-iso-alkanes and in Methanosaeta with five-iso-alkanes. This study highlights the different responses of indigenous methanogenic microbial communities in different oil sands tailings ponds to iso-alkanes.

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Quasi-graphitic carbon shell-induced Cu confinement promotes electrocatalytic CO2 reduction toward C2+ products

Nature Communications ◽

10.1038/s41467-021-24105-9 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Ji-Yong Kim ◽

Deokgi Hong ◽

Jae-Chan Lee ◽

Hyoung Gyun Kim ◽

Sungwoo Lee ◽

...

Keyword(s):

High Efficiency ◽

Co2 Reduction ◽

Value Added ◽

Material Design ◽

Catalyst System ◽

Critical Issue ◽

Reduction Reaction ◽

Catalyst Design ◽

Design Strategies ◽

Faradaic Efficiency

AbstractFor steady electroconversion to value-added chemical products with high efficiency, electrocatalyst reconstruction during electrochemical reactions is a critical issue in catalyst design strategies. Here, we report a reconstruction-immunized catalyst system in which Cu nanoparticles are protected by a quasi-graphitic C shell. This C shell epitaxially grew on Cu with quasi-graphitic bonding via a gas–solid reaction governed by the CO (g) - CO2 (g) - C (s) equilibrium. The quasi-graphitic C shell-coated Cu was stable during the CO2 reduction reaction and provided a platform for rational material design. C2+ product selectivity could be additionally improved by doping p-block elements. These elements modulated the electronic structure of the Cu surface and its binding properties, which can affect the intermediate binding and CO dimerization barrier. B-modified Cu attained a 68.1% Faradaic efficiency for C2H4 at −0.55 V (vs RHE) and a C2H4 cathodic power conversion efficiency of 44.0%. In the case of N-modified Cu, an improved C2+ selectivity of 82.3% at a partial current density of 329.2 mA/cm2 was acquired. Quasi-graphitic C shells, which enable surface stabilization and inner element doping, can realize stable CO2-to-C2H4 conversion over 180 h and allow practical application of electrocatalysts for renewable energy conversion.

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Impact of flocculation-based dewatering on the shear strength of oil sands fine tailings

Canadian Geotechnical Journal ◽

10.1139/cgj-2012-0262 ◽

2013 ◽

Vol 50 (9) ◽

pp. 1001-1007 ◽

Cited By ~ 42

Author(s):

Nicholas Beier ◽

Ward Wilson ◽

Adedeji Dunmola ◽

David Sego

Keyword(s):

Oil Sands ◽

Material Handling ◽

Performance Criteria ◽

Regulatory Requirements ◽

Strength Performance ◽

Tailings Management ◽

Fine Tailings ◽

Fluid Fine Tailings ◽

Management Techniques ◽

Reported Data

The oil sands in northern Alberta have been mined to produce bitumen over the past five decades. Since the 1980s, technical advances have been made in mining, material handling, and bitumen extraction. However, acquiring practical methods to control and reduce the fluid fine tailings build-up has been an ongoing challenge. Recent regulatory changes have driven the industry to review current tailings-management techniques and investigate numerous alternative technologies and processes to manage and reclaim fine tailings. Many of these fine tailings–management techniques involve some form of polymer or chemical addition to promote dewatering and strength gain to meet the regulatory requirements. Based on the reported data, the chemically amended fine tailings deposits have the characteristics of sensitive, metastable deposits, necessitating additional mitigative measures by oil sands operators beyond the regulatory requirements. This paper explores the geotechnical aspects of meeting regulatory strength performance criteria by employing flocculation-based dewatering of fluid fine tailings.

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Quantification of methane sources in the Athabasca Oil Sands Region of Alberta by aircraft mass balance

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-7361-2018 ◽

2018 ◽

Vol 18 (10) ◽

pp. 7361-7378 ◽

Cited By ~ 17

Author(s):

Sabour Baray ◽

Andrea Darlington ◽

Mark Gordon ◽

Katherine L. Hayden ◽

Amy Leithead ◽

...

Keyword(s):

Mass Balance ◽

Oil Sands ◽

Surface Mining ◽

Open Pit ◽

Emission Rates ◽

Athabasca Oil Sands ◽

Emissions Inventory ◽

Athabasca Oil Sands Region ◽

Major Surface ◽

Tailings Ponds

Abstract. Aircraft-based measurements of methane (CH4) and other air pollutants in the Athabasca Oil Sands Region (AOSR) were made during a summer intensive field campaign between 13 August and 7 September 2013 in support of the Joint Canada–Alberta Implementation Plan for Oil Sands Monitoring. Chemical signatures were used to identify CH4 sources from tailings ponds (BTEX VOCs), open pit surface mines (NOy and rBC) and elevated plumes from bitumen upgrading facilities (SO2 and NOy). Emission rates of CH4 were determined for the five primary surface mining facilities in the region using two mass-balance methods. Emission rates from source categories within each facility were estimated when plumes from the sources were spatially separable. Tailings ponds accounted for 45 % of total CH4 emissions measured from the major surface mining facilities in the region, while emissions from operations in the open pit mines accounted for ∼ 50 %. The average open pit surface mining emission rates ranged from 1.2 to 2.8 t of CH4 h−1 for different facilities in the AOSR. Amongst the 19 tailings ponds, Mildred Lake Settling Basin, the oldest pond in the region, was found to be responsible for the majority of tailings ponds emissions of CH4 (> 70 %). The sum of measured emission rates of CH4 from the five major facilities, 19.2 ± 1.1 t CH4 h−1, was similar to a single mass-balance determination of CH4 from all major sources in the AOSR determined from a single flight downwind of the facilities, 23.7 ± 3.7 t CH4 h−1. The measured hourly CH4 emission rate from all facilities in the AOSR is 48 ± 8 % higher than that extracted for 2013 from the Canadian Greenhouse Gas Reporting Program, a legislated facility-reported emissions inventory, converted to hourly units. The measured emissions correspond to an emissions rate of 0.17 ± 0.01 Tg CH4 yr−1 if the emissions are assumed as temporally constant, which is an uncertain assumption. The emission rates reported here are relevant for the summer season. In the future, effort should be devoted to measurements in different seasons to further our understanding of the seasonal parameters impacting fugitive emissions of CH4 and to allow for better estimates of annual emissions and year-to-year variability.

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Addition of Tubifex accelerates dewatering of oil sands tailings

Canadian Journal of Civil Engineering ◽

10.1139/cjce-2016-0308 ◽

2016 ◽

Vol 43 (12) ◽

pp. 1025-1033 ◽

Cited By ~ 1

Author(s):

Xiaojuan Yang ◽

Miguel de Lucas Pardo ◽

Maria Ibanez ◽

Lijun Deng ◽

Luca Sittoni ◽

...

Keyword(s):

Oil Sands ◽

Land Reclamation ◽

Test Results ◽

Anionic Polymer ◽

Fine Tailings ◽

Fluid Fine Tailings ◽

Oil Sands Tailings ◽

Set Up ◽

Solids Content

Accelerating dewatering of fluid fine tailings (FFT) to facilitate land reclamation is a major challenge to the oil sands industry in Canada. A new method was tested, addition of Tubifex to FFT. Tubifex is an indigenous earthworm in Canada. The survival rate tests showed that Tubifex can survive in oil sands tailings and penetrate to 42 cm depth (maximum depth tested). Columns (5 L of FFT) were set-up with tailings alone, Tubifex treated tailings and polymer-Tubifex treated tailings. Test results showed that (a) the final mud–water interface of tailings alone was 26% higher than that of Tubifex treated tailings; (b) solids content of Tubifex treated tailings was 21% more than that of tailings alone; (c) Tubifex was capable to accelerate the dewatering process of both cationic and anionic polymer treated tailings; (d) anionic polymer was superior in facilitating long-term dewatering and its coupled effects with Tubifex were better than the cationic polymer.

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