Adsorption and interaction mechanisms of Chi-g-P(AM-DMDAAC) assisted settling of kaolinite in a two-step flocculation process

Xu, Ruijing; Zou, Wenjie; Wang, Ting; Huang, Jun; Zhang, Zhijun; Xu, Chaohe

doi:10.1016/j.scitotenv.2021.151576

Cited by 27 publications

(12 citation statements)

References 47 publications

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Section: Resultsmentioning

confidence: 99%

“…Better performances for this order of addition have been reported in other MFT flocculation studies, [14,16,17] but it does not seem to be universally true for all flocculations. [12,13,18,27] T A B L E 2 Elemental analysis, degrees of hydrolysis, and zeta potentials of HPAM samples. Control experiments using only the HPAM or PVBTMAC were also done.…”

Section: Flocculation Experimentsmentioning

confidence: 99%

“…[6][7][8] Recent MFT flocculations with two polymers show that they can outperform single flocculants. [7,[10][11][12][13][14][15][16][17] Lu et al treated oil sands tailings with a commercial anionic PAM and the natural cationic polymer chitosan, showing that the dual system promoted faster settling rates than chitosan, and higher supernatant clarities than anionic PAM. [17] Loerke et al treated MFT with dual polymer flocculants, followed by filtration to enhance dewatering.…”

Section: Introductionmentioning

confidence: 99%

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Flocculating oil sands tailings with dual anionic/cationic polymers: Dose and charge density effects

Dixon

Soares

2023

Can J Chem Eng

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A two‐step process, with anionic hydrolyzed polyacrylamide (HPAM) and cationic poly(vinylbenzyl trimethylammonium chloride) (PVBTMAC), was used to flocculate oil sands mature fine tailings (MFT). The charge density of HPAM and the dosages of HPAM and PVBTMAC were varied to maximize the dewatering of MFT and minimize the turbidity of the supernatant. The dual flocculant system performed better at lower doses than when used alone. The best HPAM charge density for fast initial settling rate and high sediment solids content was 32%, but it increased to 38% for best sediment dewatering, as measured by capillary suction time. The clearest supernatants were found when the zeta potential approached 0 mV because the cationic PVBTMAC neutralized the surface charges of the particles suspended in the MFT. More importantly, undiluted MFT was flocculated with the HPAM/PVBTMAC system and then filtered at low‐pressure (69 kPag), resulting in a filter cake with a high solids content of 61 wt.%. This study shows that treating MFT with a combination of anionic and cationic polymer is a flexible way to optimize flocculation performance.

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Section: Resultsmentioning

confidence: 99%

Section: Flocculation Experimentsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Flocculating oil sands tailings with dual anionic/cationic polymers: Dose and charge density effects

Dixon

Soares

2023

Can J Chem Eng

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“…Certain compounds are present on specific types of biocoagulants/bioflocculants, such as chitin and chitosan. The chitosan molecular chain contains abundant amino and hydroxyl active groups, which have good flocculation, chelating, and ion-exchange properties, and are ideal cationic flocculants [ 17 , 18 ]. Chitosan is mainly formed through adsorption bridging, electric neutralization, and group reactions to aggregate flocculated substances into macromolecules and precipitates [ 17 , 18 ].…”

Section: Introductionmentioning

confidence: 99%

“…The chitosan molecular chain contains abundant amino and hydroxyl active groups, which have good flocculation, chelating, and ion-exchange properties, and are ideal cationic flocculants [ 17 , 18 ]. Chitosan is mainly formed through adsorption bridging, electric neutralization, and group reactions to aggregate flocculated substances into macromolecules and precipitates [ 17 , 18 ]. Chen [ 19 ] synthesized a new type of chelating flocculant with a branched structure by combining chitosan and PAM, and a flocculation test was performed on simulated wastewater.…”

Section: Introductionmentioning

confidence: 99%

The Synergistic Effects of Al3+ and Chitosan on the Solid–Liquid Separation of Coal Wastewater and Their Mechanism of Action

Chang

Dong

et al. 2022

Polymers

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It is important to identify an environmentally friendly and efficient flocculant that can replace polyacrylamide for the solid–liquid separation of coal wastewater. In this study, to explore whether chitosan can be used as an environmentally friendly and efficient flocculant for the solid–liquid separation of coal wastewater, AlCl3–chitosan was used to conduct flocculation–sedimentation and dewatering tests under different chitosan dosages and shear-strength conditions for the prepared coal wastewater. Focused beam reflectance was measured to dynamically monitor the number of refractory fine particles, and the settled flocs were photographed and analyzed with microscopy to explore the effect of AlCl3–chitosan on the flocculation settlement effect and floc characteristics. The synergistic mechanisms of AlCl3 and chitosan were investigated using quartz crystal dissipative microbalance and zeta potential measurement. The results showed that the addition of chitosan can significantly improve the flocculation–sedimentation and dewatering effects of coal wastewater. A reasonable dosage under a certain shear strength is conducive to the reduction of fine slime particles, which results in a compact floc structure, increases the floc size, and improves the settling effect. The synergistic effect of AlCl3–chitosan improved the electric neutralization and adsorption bridging abilities of the chitosan, and the mixed solution of AlCl3 and chitosan had stronger adsorption on the carbon surface. This study provides a new approach to the selection of flocculants for coal wastewater treatment.

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Application of molecular dynamics simulations in interface interaction of clay: Current status and perspectives

Chen

Chu

Cheng

et al. 2023

Asia-Pacific J Chem Eng

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To understand the research progress of molecular dynamics (MD) method in the field of clay minerals, the application of MD in the interface interaction of clay minerals is reviewed in this paper. MD simulations have become the indispensable means to study mineral interface effects. Clay minerals are common associated minerals with hydrophilic surface, the ease of argillization, negative electricity, and the ability of forming impurities and defects. They are widely concerned in the fields of mine wastewater treatment, fine clay mineral flotation, shale oil and gas exploitation, and so forth. In addition, clay minerals are considered as natural adsorbents due to their large specific surface area, but their complex interface interactions hinder their effective utilization. Therefore, it is particularly important to reveal the interaction mechanism of clay interface at the atomic/molecular level by means of software simulation technology. In this review, our focus is on the applications of MD method in the field of clay mineral interface interaction, such as clay/gas interface, clay/water interface, agents and clay/water interface, and mineral particle and clay/water interface. Furthermore, the history and shortcomings of MD simulation are summarized. The research and effective utilization of clay interface are summarized and prospected as well.

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Adsorption and interaction mechanisms of Chi-g-P(AM-DMDAAC) assisted settling of kaolinite in a two-step flocculation process

Cited by 27 publications

References 47 publications

Flocculating oil sands tailings with dual anionic/cationic polymers: Dose and charge density effects

Flocculating oil sands tailings with dual anionic/cationic polymers: Dose and charge density effects

The Synergistic Effects of Al3+ and Chitosan on the Solid–Liquid Separation of Coal Wastewater and Their Mechanism of Action

Application of molecular dynamics simulations in interface interaction of clay: Current status and perspectives

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