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Li Y, Yao S, Dong X, Fan Y, Ma X, Zhu B, Chang M. Preparation of a Lignin-Based Cationic Flocculant and Its Application in Kaolin Suspension Treatment. Polymers (Basel) 2024; 16:1131. [PMID: 38675049 PMCID: PMC11054052 DOI: 10.3390/polym16081131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 04/11/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024] Open
Abstract
The preparation of an environmentally friendly and efficient flocculant for solid-liquid separation in industrial wastewater is highly important. In this study, a novel cationic flocculant (AL-g-PAMA) was synthesized by a thermal initiation method using alkali lignin (AL) as the main chain and acrylamide (AM) and methacrylamido propyl trimethyl ammonium chloride (MAPTAC) as the grafted side chains. The structure, thermal stability, and surface morphology of the copolymers were investigated by various characterization methods. The results indicated the successful synthesis of AL-g-PAMA. AL-g-PAMA was applied to improve solid-liquid separation in kaolin suspensions. The results showed that AL-g-PAMA had excellent flocculation-sedimentation and dewatering efficiency. When the dosage of AL-g-PAMA #5 was 600.0 g/t(s), the thickness of the compressed layer was 2.2 cm, the floc settling velocity was 24.1 cm/min, and the transmittance of the supernatant was 84.0%. The moisture content of the filter cake decreased from 55.0% to 43.4% after treatment with AL-g-PAMA #5. The results of zeta potential and focused beam reflectance measurement (FBRM) analysis indicated that bridging and electroneutralization were the main flocculation mechanisms. Therefore, this study extends the potential for using lignin as a bioflocculant and provides a feasible approach to efficiently purify high-turbidity wastewater.
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Affiliation(s)
- Yan Li
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Suling Yao
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Xianshu Dong
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Yuping Fan
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Xiaomin Ma
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
- State Key Laboratory of Mineral Processing, Beijing 100160, China
| | - Benkang Zhu
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Ming Chang
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
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2
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Wang D, Wang D, Tan X, Yeung A, Liu Q. A review of the roles of constituent minerals and residual bitumen in the solid-liquid separation of oil sands tailings. JOURNAL OF HAZARDOUS MATERIALS 2023; 451:131178. [PMID: 36921411 DOI: 10.1016/j.jhazmat.2023.131178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 03/04/2023] [Accepted: 03/07/2023] [Indexed: 06/18/2023]
Abstract
The efficient dewatering of fluid fine tailings (FFT) generated from warm-water extraction of Canadian oil sands is a major challenge that has limited the timely reclamation of the tailings. It is generally recognized that both chemical amendments and physical/mechanical solid-liquid separation treatments are required to speed up FFT dewatering. Significant efforts have been made to enhance the rate of solid-liquid separation of FFT in the past several decades. The fact that these efforts have met with limited successes calls for a better fundamental understanding of the solid-liquid separation process. In this work, we reviewed and critically analyzed the factors that contribute to the difficult dewatering of FFT, including the role of constituent minerals and residual bitumen. In particular, the effects of mineralogical composition, mineral particle size, and the role of residual bitumen on settling rate, hydraulic conductivity, and filtration rate are reviewed and discussed. This review also points out directions to accelerate the dewatering of FFT, such as reducing the effective volume fraction of swelling clays and releasing bitumen coating from clay surfaces, that may significantly increase the filtration rate of oil sands tailings.
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Affiliation(s)
- Dong Wang
- Department of Chemical and Materials Engineering, University of Alberta, 9211-116 Street, Edmonton, Alberta T6G 1H9, Canada
| | - Daowei Wang
- Department of Chemical and Materials Engineering, University of Alberta, 9211-116 Street, Edmonton, Alberta T6G 1H9, Canada
| | - Xiaoli Tan
- Department of Chemical and Materials Engineering, University of Alberta, 9211-116 Street, Edmonton, Alberta T6G 1H9, Canada
| | - Anthony Yeung
- Department of Chemical and Materials Engineering, University of Alberta, 9211-116 Street, Edmonton, Alberta T6G 1H9, Canada
| | - Qi Liu
- Department of Chemical and Materials Engineering, University of Alberta, 9211-116 Street, Edmonton, Alberta T6G 1H9, Canada.
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3
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Girase CD, Rajput YN, Hatkar VM, Kulkarni RD. Synthesis and characterizations of cationic poly(DADMAC-co-AM) surfactant for hair care applications. JOURNAL OF POLYMER RESEARCH 2022. [DOI: 10.1007/s10965-022-03113-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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4
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Davey S, Soares JBP. Amylopectin graft copolymers for oil sands tailings treatment. CAN J CHEM ENG 2021. [DOI: 10.1002/cjce.24290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Stepheney Davey
- Department of Chemical and Materials Engineering University of Alberta Edmonton Alberta Canada
| | - João B. P. Soares
- Department of Chemical and Materials Engineering University of Alberta Edmonton Alberta Canada
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5
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Saborimanesh N. Toward sustainable remediation of oil sands fine Tailings-A review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 288:112418. [PMID: 33839539 DOI: 10.1016/j.jenvman.2021.112418] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 03/07/2021] [Accepted: 03/16/2021] [Indexed: 06/12/2023]
Abstract
Significant quantities of tailings are produced during the extraction of bitumen from oil sands. Tailings are stored in tailings ponds for several years before they can be appropriately managed. Current fine tailings management approaches include mechanical and/or chemical amendments of fine tailings (FT) to speed up tailings reclamation. However, complex structures of fine tailings, stringent tailings management regulations, failure in production of trafficable deposits with current FT reclamation technologies and biogenic gas (e.g., CH4) generations have prompted the re-evaluation of current FT remediation technologies and exploration of alternative biological treatments (e.g., bioaugmentation and biostimulation). Biological treatments have proven to effectively remediate environmental pollutants by creating favourable environments for the desire microorganisms. Thus their effects on FT reclamation have been increasingly investigated in the last two decades. Many of these studies confirmed that biological treatments can improve FT dewatering and densification. However, other studies found that not all biological treatments can effectively suppress CH4 generations or they may lead to the generation of other biogenic gases (e.g., H2S, N2O, NO). Therefore, it is critical to identify potential environmental risks associated with the biological treatments before their full-scale applications. This review revolved around two questions. First, whether bioaugmentation and biostimulation methods can improve FT reclamation. Secondly, what are the potential environmental issues that may arise from the applications of biological treatments. To address these questions, the existing peer-reviewed documents on fine tailings management were carefully reviewed to provide an introduction to the currently practiced FT reclamation technologies. Further discussions on biological treatments and their potentials and limitations were also presented. Finally, the review highlighted the knowledge gap in the area of biological treatments of FT and provided recommendations for future research.
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Affiliation(s)
- Nayereh Saborimanesh
- Natural Resources Canada, CanmetENERGY, 1 Oil Patch Drive, Devon, AB T9G 1A8, Canada.
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6
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Reduction of asphaltenes adsorbed on kaolinite by polymers based on cardanol. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2020. [DOI: 10.1007/s43153-020-00082-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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7
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Miles SM, Asiedu E, Balaberda AL, Ulrich AC. Oil sands process affected water sourced Trichoderma harzianum demonstrates capacity for mycoremediation of naphthenic acid fraction compounds. CHEMOSPHERE 2020; 258:127281. [PMID: 32540545 DOI: 10.1016/j.chemosphere.2020.127281] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 05/27/2020] [Accepted: 05/30/2020] [Indexed: 06/11/2023]
Abstract
Development of Alberta's oil sands requires large volumes of water, leading to the abundance of oil sands process affected water (OSPW) that must be remediated prior to discharge or reuse. OSPW contains a variety of dissolved organic compounds, however naphthenic acids (NAs) have been found to contribute significantly to the toxicity of OSPW. A fungus, Trichoderma harzianum, isolated directly from OSPW, has previously demonstrated a high tolerance and capacity for growth in the presence of commercial NAs. This study conducted microcosm experiments to elucidate and characterize the capacity of T. harzianum to degrade labile commercial NAs (Merichem), and OSPW-sourced naphthenic acid fraction compounds (NAFCs). Additionally, two model NA compounds, the simple single ring cyclohexane carboxylic acid (CHCA) and complex diamondoid 1-adamanatane carboxylic acid (ADA), were utilized to determine the influence of NA structure on degradation. T. harzianum degraded 14% of CHCA, 13% of ADA, and 23-47% of Merichem NAs. Additionally, Orbitrap mass spectrometry revealed a large change in Z-series within NAFCs. This removal and shift in composition correlated to a 59% and 52% drop in toxicity as per Microtox, for Merichem NAs and NAFCs respectively. This proof of concept experiment confirms that the fungal species T. harzianum can contribute to the biodegradation of complex dissolved organics found in OSPW, including cyclic and diamondoid structures.
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Affiliation(s)
- Sarah M Miles
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Evelyn Asiedu
- Department of Laboratory Medicine and Pathology, Division of Analytical and Environmental Toxicology, University of Alberta, Edmonton, Alberta, Canada
| | - Amy-Lynne Balaberda
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Ania C Ulrich
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada.
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8
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Nittala AK, Gumfekar SP, Soares JBP. Multifunctional CO 2
-switchable polymers for the flocculation of oil sands tailings. J Appl Polym Sci 2019. [DOI: 10.1002/app.47578] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Atreya K. Nittala
- Department of Chemical and Materials Engineering; University of Alberta; Edmonton, T6G 2V4 Alberta Canada
| | - Sarang P. Gumfekar
- Department of Chemical and Materials Engineering; University of Alberta; Edmonton, T6G 2V4 Alberta Canada
| | - João B. P. Soares
- Department of Chemical and Materials Engineering; University of Alberta; Edmonton, T6G 2V4 Alberta Canada
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9
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Entezari I, Rivard B, Vajihinejad V, Wilson WG, Soares JBP, Fisseha B, Beier N. Monitoring tailings flocculation performance using hyperspectral imagery. CAN J CHEM ENG 2019. [DOI: 10.1002/cjce.23493] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Iman Entezari
- Department of Earth and Atmospheric SciencesUniversity of Alberta Edmonton AB Canada
| | - Benoit Rivard
- Department of Earth and Atmospheric SciencesUniversity of Alberta Edmonton AB Canada
| | - Vahid Vajihinejad
- Department of Chemical and Materials EngineeringUniversity of Alberta Edmonton AB Canada
| | - Ward G. Wilson
- Department of Civil and Environmental EngineeringUniversity of Alberta Edmonton AB Canada
| | - João B. P. Soares
- Department of Chemical and Materials EngineeringUniversity of Alberta Edmonton AB Canada
| | - Bereket Fisseha
- Department of Civil and Environmental EngineeringUniversity of Alberta Edmonton AB Canada
| | - Nicholas Beier
- Department of Civil and Environmental EngineeringUniversity of Alberta Edmonton AB Canada
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10
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Suresha PR, Badiger MV. Flocculation of kaolin from aqueous suspension using low dosages of acrylamide‐based cationic flocculants. J Appl Polym Sci 2018. [DOI: 10.1002/app.47286] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- P. R. Suresha
- Polymer Science and Engineering DivisionCSIR‐National Chemical Laboratory Dr. Homi Bhabha Road, Pune 411008 India
| | - Manohar V. Badiger
- Polymer Science and Engineering DivisionCSIR‐National Chemical Laboratory Dr. Homi Bhabha Road, Pune 411008 India
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11
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Gumfekar SP, Vajihinejad V, Soares JBP. Advanced Polymer Flocculants for Solid-Liquid Separation in Oil Sands Tailings. Macromol Rapid Commun 2018; 40:e1800644. [PMID: 30417463 DOI: 10.1002/marc.201800644] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/04/2018] [Indexed: 01/09/2023]
Abstract
The generation of tailings as a by product of the bitumen extraction process is one of the largest environmental footprints of oil sands operations. Most of the tailings treatment technologies use polymer flocculants to induce solid-liquid separation. However, due to the complex composition of tailings, conventional flocculants cannot reach the same performance achieved in other wastewater treatments. Over the last couple of decades, the oil sands industry has used acrylamide-based flocculants to treat tailings, achieving major progress in process optimization and integration with mechanical operations, but they still could not reach the required land reclamation targets. Over the last 5 years, the group designed, synthesized, and tested several novel polymer flocculants tailored for oil sands tailings treatment. This feature article communicates recent developments in these innovative polymers. The article first provides a background on tailings generation and treatment, followed by the description of advanced polymer flocculants categorized according to their microstructures such as linear, branched, and graft. The other tailings remediation technologies and one of the initial works on modeling of tailings flocculation is discussed.
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Affiliation(s)
- Sarang P Gumfekar
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 2V4, Canada
| | - Vahid Vajihinejad
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 2V4, Canada
| | - João B P Soares
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 2V4, Canada
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12
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Gumfekar SP, Soares JBP. Polymer reaction engineering tools to design multifunctional polymer flocculants. CHEMOSPHERE 2018; 210:156-165. [PMID: 29990754 DOI: 10.1016/j.chemosphere.2018.06.175] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 06/13/2018] [Accepted: 06/28/2018] [Indexed: 06/08/2023]
Abstract
A series of multifunctional terpolymers, poly(N-isopropyl acrylamide/2-(methacryloyloxy) ethyl trimethyl ammonium chloride/N-tert-butylacrylamide) [P(NIPAM-MATMAC-BAAM)], were designed to flocculate and dewater oil sands mature fine tailings (MFT). The hydrophobic BAAM comonomer helped in expelling water from the sediments, while the cationic MATMAC comonomer promoted the charge neutralization of negatively charged particles suspended in MFT. The chemical composition distributions of these terpolymers were designed based on the knowledge of the reactivity ratios of all comonomers, instead of by trial and error, as usually done for most polymer flocculants. The binary reactivity ratios of the comonomers were estimated by synthesizing the binary copolymers with various mole fractions of each comonomer in the feed and experimentally measuring the corresponding fraction of comonomer in the copolymers. Polymer reaction engineering tools were used to minimize compositional drift and guarantee the synthesis of terpolymers with narrow chemical composition distributions suitable for MFT dewatering. Focused beam reflectance measurement (FBRM) experiments showed that terpolymers promoted the formation of large MFT flocs (120 μm). The initial settling rate decreased with the increase in flocculant hydrophobicity, likely because the hydrophobic terpolymer segments did not take part in the bridging of the MFT particles. In contrast, the sediment dewaterability increased with the increase in terpolymer hydrophobicity. This study provides guidelines to design a polymer flocculant from first principles and demonstrates the potential of using hydrophobically modified cationic polymers to flocculate MFT effectively.
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Affiliation(s)
- Sarang P Gumfekar
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 2V4, Canada.
| | - João B P Soares
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 2V4, Canada.
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13
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Motta FL, Gaikwad R, Botha L, Soares JBP. Quantifying the effect of polyacrylamide dosage, Na + and Ca 2+ concentrations, and clay particle size on the flocculation of mature fine tailings with robust statistical methods. CHEMOSPHERE 2018; 208:263-272. [PMID: 29879560 DOI: 10.1016/j.chemosphere.2018.05.171] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 05/23/2018] [Accepted: 05/27/2018] [Indexed: 06/08/2023]
Abstract
Polymer-driven flocculation and dewatering of mature fine tailings (MFT) is critical to improve their consolidation. MFT flocculation and dewatering depends on the size of the suspended clay particles, and on the composition and properties of the liquid in which they are dispersed. The effect of water chemistry on the polymer-particle dynamics is nontrivial, particularly for non-spherical, polydisperse particles such as natural clays. In this study, we used a response surface methodology to systematically assess the impact of Na+ and Ca2+ concentration and anionic polyacrylamide dosage in the flocculation and dewatering of MFT. We observed a beneficial synergistic effect between Ca2+ concentration and polyacrylamide dosage, although excess of Ca2+ may reduce polyacrylamide activity. In addition, we investigated the impact of clay particle size on MFT flocculation. Polyacrylamide did not flocculate MFT fractions where the fine clay particles (<2 μm) represented most of the population. Good settling, however, was observed when fine silt particles (from 2 to 44 μm) were present, indicating that the presence and accumulation of larger/heavier particles on the polymer-induced flocs is crucial to form aggregates that readily settle under gravity. The insights gained from this study can contribute to more efficient use of flocculants, more effective use of cations, and better understanding of the impact of particles size in MFT flocculation.
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Affiliation(s)
- Fernanda L Motta
- Department of Chemical and Materials Engineering, University of Alberta, 9211 116 St, Edmonton, AB T6G 1H9, Canada
| | - Rohankumar Gaikwad
- Department of Chemical and Materials Engineering, University of Alberta, 9211 116 St, Edmonton, AB T6G 1H9, Canada
| | - Linda Botha
- Department of Chemical and Materials Engineering, University of Alberta, 9211 116 St, Edmonton, AB T6G 1H9, Canada
| | - João B P Soares
- Department of Chemical and Materials Engineering, University of Alberta, 9211 116 St, Edmonton, AB T6G 1H9, Canada.
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14
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Wilts EM, Herzberger J, Long TE. Addressing water scarcity: cationic polyelectrolytes in water treatment and purification. POLYM INT 2018. [DOI: 10.1002/pi.5569] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Emily M Wilts
- Department of Chemistry; Macromolecules Innovation Institute, Virginia Tech; Blacksburg USA
| | - Jana Herzberger
- Department of Chemistry; Macromolecules Innovation Institute, Virginia Tech; Blacksburg USA
| | - Timothy E Long
- Department of Chemistry; Macromolecules Innovation Institute, Virginia Tech; Blacksburg USA
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15
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Hripko R, Vajihinejad V, LopesMotta F, Soares JBP. Enhanced Flocculation of Oil Sands Mature Fine Tailings Using Hydrophobically Modified Polyacrylamide Copolymers. GLOBAL CHALLENGES (HOBOKEN, NJ) 2018; 2:1700135. [PMID: 31565327 PMCID: PMC6607254 DOI: 10.1002/gch2.201700135] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 01/18/2018] [Indexed: 06/08/2023]
Abstract
Hydrophobically modified acrylamide copolymers dewater oil sands tailings more effectively than anionic polyacrylamide, but the root causes for this enhanced performance have not been investigated systematically. Polyacrylamide-poly(ethylene oxide methyl ether methacrylate) copolymers with different comonomer compositions, hydrophobic chain lengths, and molecular weights to map out these effects systematically are synthetized. Through a statistical design of experiments, it is found out that all three variables above significantly affected flocculation performance and that certain combinations achieve optimal results. The effect of centrifugation on the flocculation and dewatering performance of these polymers is also investigated.
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Affiliation(s)
- Rhys Hripko
- Department of Chemical and Materials EngineeringUniversity of Alberta9211 116 StEdmontonAlbertaT6G 1H9Canada
| | - Vahid Vajihinejad
- Department of Chemical and Materials EngineeringUniversity of Alberta9211 116 StEdmontonAlbertaT6G 1H9Canada
| | - Fernanda LopesMotta
- Department of Chemical and Materials EngineeringUniversity of Alberta9211 116 StEdmontonAlbertaT6G 1H9Canada
| | - João B. P. Soares
- Department of Chemical and Materials EngineeringUniversity of Alberta9211 116 StEdmontonAlbertaT6G 1H9Canada
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16
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Gumfekar SP, Soares JBP. A novel hydrophobically-modified polyelectrolyte for enhanced dewatering of clay suspension. CHEMOSPHERE 2018; 194:422-431. [PMID: 29227890 DOI: 10.1016/j.chemosphere.2017.12.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 11/26/2017] [Accepted: 12/02/2017] [Indexed: 06/07/2023]
Abstract
This work investigates the effect of multifunctional poly (N-isopropyl acrylamide/acrylic acid/N-tert-butylacrylamide) [p(NIPAM-AA-NTBA)] ternary polymer on the sedimentation of kaolin clay - a major fraction of oil sands tailings. A series of linear, uncross-linked p(NIPAM), p(NIPAM/AA), and p(NIPAM/AA/NTBM) were synthesized as random copolymers, where all monomer units were randomly arranged along the polymer backbone and connected by covalent bonds. The ternary copolymer, used as a flocculant, exhibited thermo-sensitivity, anionic nature, and hydrophobic association due to NIPAM, AA, and NTBM, respectively. As the ternary polymer is thermosensitive, it undergoes extended to coil-like conformation, i.e. hydrophilic to hydrophobic transition, above its lower critical solution temperature (LCST). The comonomers NIPAM (above LCST) and NTBM help expel water out of sediments due to their hydrophobicity, while AA promotes charge neutralization of the kaolin clay particles. The effect of number average molecular weight, charge density, and concentration of NTBM on settling behavior of kaolin suspension was examined. Settling test at 50 °C resulted in significantly higher settling rates compared to that at room temperature. Further, the quality of water recovered in each experiment was tested in terms of its turbidity. These results indicate that this novel ternary polymer can be employed to enhance the recovery of water from oil sands tailings containing clays.
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Affiliation(s)
- Sarang P Gumfekar
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 2V4, Canada.
| | - João B P Soares
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 2V4, Canada.
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17
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Gumfekar SP, Rooney TR, Hutchinson RA, Soares JBP. Dewatering Oil Sands Tailings with Degradable Polymer Flocculants. ACS APPLIED MATERIALS & INTERFACES 2017; 9:36290-36300. [PMID: 28945965 DOI: 10.1021/acsami.7b10302] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We synthesized hydrolytically degradable cationic polymers by micellar radical polymerization of a short-chain polyester macromonomer, polycaprolactone choline iodide ester methacrylate (PCL2ChMA) with two polyester units, and used them to flocculate oil sands mature fine tailings (MFT). We evaluated the flocculation performance of the homopolymer and copolymers with 30 mol % acrylamide (AM) by measuring initial settling rate (ISR), supernatant turbidity, and capillary suction time (CST) of the sediments. Flocculants made with trimethylaminoethyl methacrylate chloride (TMAEMC), the monomer corresponding to PCLnChMA with n = 0, have improved performance over poly(PCL2ChMA) at equivalent loadings due to their higher charge density per gram of polymer. However, MFT sediments flocculated using the PCL2ChMA-based polymers are easier to dewater (up to an 85% reduction in CST) after accelerated hydrolytic degradation of the polyester side chains. This study demonstrates the potential of designing cationic polymers that effectively flocculate oil sands tailings ponds, and also further dewater the resulting solids through polymer degradation.
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Affiliation(s)
- Sarang P Gumfekar
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 2V4, Canada
| | - Thomas R Rooney
- Department of Chemical Engineering, Queen's University , Kingston, Ontario K7L 3N6, Canada
| | - Robin A Hutchinson
- Department of Chemical Engineering, Queen's University , Kingston, Ontario K7L 3N6, Canada
| | - João B P Soares
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 2V4, Canada
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