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Tang S, Huang S, Chen P, Wu Z, Zhao T. Comprehensive assessment of enhancing dewaterability of dredged sediments by starch-based flocculant. RSC Adv 2024; 14:17547-17556. [PMID: 38828273 PMCID: PMC11140457 DOI: 10.1039/d4ra02189d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 05/25/2024] [Indexed: 06/05/2024] Open
Abstract
Dredged sediment poses significant challenges for transportation and subsequent treatment due to its high water content and large volume. Coagulation, a common method of dewatering, can significantly enhance the dewatering performance of dredged sediment. This study synthesized a cationic starch-based flocculant [starch-3-chloro-2-hydroxypropyl trimethylammonium chloride (St-CTA)] through etherification for the flocculation dewatering of dredged sediment. The effectiveness and mechanism of St-CTA as a dewatering flocculant for dredged sediment were investigated. The results demonstrated that when the dosage of St-CTA was 12 mg g-1 TSS (total suspended solids), the dehydration property of dredged sediment substantially improved, with the specific resistance to filtration (SRF) decreasing by 93.3%, the capillary suction time (CST) by 93.5%, and the water content of the filter cake (WC) by 9.7%. The removal rate of turbidity of the supernatant from the conditioned dredged sediment reached 99.6%, accelerating the settling speed and effectively capturing and separating fine particles from the sediment. St-CTA significantly increased the median particle size (D50), altered the microstructure and extracellular polymeric substances (EPS) of the flocs, and increased the fractal dimension of the flocs, making them more compact and conducive to the formation of drainage channels. These findings confirm the feasibility of using potentially environmentally friendly St-CTA as a rapid dewatering conditioning agent for sediment.
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Affiliation(s)
- Shilei Tang
- School of Environment and Energy, South China University of Technology Higher Education Mega Center Guangzhou 510006 P. R. China
| | - Shaobin Huang
- School of Environment and Energy, South China University of Technology Higher Education Mega Center Guangzhou 510006 P. R. China
| | - Pengfei Chen
- School of Environment and Energy, South China University of Technology Higher Education Mega Center Guangzhou 510006 P. R. China
| | - Zhipeng Wu
- School of Environment and Energy, South China University of Technology Higher Education Mega Center Guangzhou 510006 P. R. China
| | - Tianyu Zhao
- School of Environment and Energy, South China University of Technology Higher Education Mega Center Guangzhou 510006 P. R. China
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2
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Ma XY, Liu Z, Xia Z, Su CX, Cheng Y, Yu H, Kang X. Quantitative examination of microstructural transformations of clay-rich sediments in river-dominated deltas under the influence of polluted pore water. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 334:122177. [PMID: 37453684 DOI: 10.1016/j.envpol.2023.122177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 06/21/2023] [Accepted: 07/09/2023] [Indexed: 07/18/2023]
Abstract
Coastal water pollution has a significant impact on sedimentary environments, altering the microstructure of clay-rich sediments and further destabilizing river-dominated delta strata. However, the understanding of the microstructure of clay sediment, influenced by burial depth and pore water chemistry, remains limited due to challenges in quantitatively analyzing clay texture at varying depths. The perturbable of clay microstructures, and the cost of deep sampling have hindered such efforts. To address this issue, this study aims to quantitatively analyze the clay anisotropy at different depths and pore water chemistry through laboratory-simulated sediment samples by using centrifugal modeling and 2DXRD technology. The results suggest that 1DXRD (Orientation index) is prone to generating incorrect conclusions, whereas 2DXRD (pole density) yields more precise and reliable results. Specifically, the results indicated that the introduction of salt ions promoted clay precipitation and stabilized the oriented microstructure at shallower depths. In acidic solutions, clay sediment still contained a certain proportion of edge to face (EF) microstructure at depths less than 6 m, suggesting higher soil thixotropy and lower strength than that of clay sediments in other types of solutions. Overall, our findings provide valuable insights into the relationship between water pollution, delta disappearance, and ocean acidification, highlighting the urgent need for effective environmental management strategies to prevent further damage to fragile coastal ecosystems.
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Affiliation(s)
- Xiong-Ying Ma
- College of Civil Engineering, Hunan University, Changsha, China
| | - Zhan Liu
- CCFEB Civil Engineering Co., Ltd., Changsha, 410004, China
| | - Zhao Xia
- Earth Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Chen-Xi Su
- College of Civil Engineering, Hunan University, Changsha, China
| | - Yin Cheng
- Engineering Technology and Materials Research Center, China Academy of Transportation Sciences, Beijing, China
| | - Hao Yu
- Engineering Technology and Materials Research Center, China Academy of Transportation Sciences, Beijing, China
| | - Xin Kang
- College of Civil Engineering, Hunan University, Changsha, China.
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3
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Wang S, Chen Y, Chen R, Ma X, Kang X. Steerable artificial magnetic bacteria with target delivery ability of calcium carbonate for soil improvement. Appl Microbiol Biotechnol 2023; 107:5687-5700. [PMID: 37480371 DOI: 10.1007/s00253-023-12665-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 06/22/2023] [Accepted: 06/27/2023] [Indexed: 07/24/2023]
Abstract
The microbial-induced carbonate precipitation (MICP) has acquired significant attention due to its immense potential in sustainable engineering applications, particularly in soil improvement. However, the precise control of microbial-induced calcium carbonate precipitation remains a formidable challenge in engineering practices, owing to the uncertain movement paths of bacteria and the nonuniform distribution of soil pores. Taking inspiration from targeted therapy in medicine, this paper presents novel research on the development and validation of magnetically responsive bacteria. These bacteria demonstrate the ability to target calcium carbonate precipitation in a microfluidic chip, thereby promoting an environmentally friendly and ecologically sustainable biomineralization paradigm. The study focuses on investigating the migration of magnetite nanoparticles (MNPs) in aqueous solutions and enhancing the stability of MNP culture liquids. A specially designed microfluidic chip is utilized to simulate natural sand particles and their pores, while an external magnetic field is applied to precisely control the movement path of the artificial magnetic bacteria, enabling targeted precipitation of calcium carbonate at the micron-scale. Verification of the engineered artificial magnetic bacteria and their ability to induce calcium carbonate precipitation is conducted through SEM-EDS analysis, microfluidic chip observations, and the application of the K-means algorithm and ImageJ software to analyze calcium carbonate formation. The influence of the concentration of magnetic nanoparticles on the calcium carbonate production rate was also studied. The results confirm the potential of the artificial magnetic bacteria for future engineering applications. KEY POINTS: • Sporosarcina pasteurii is first time successfully engineered into artificial magnetic bacteria. • The artificial magnetic bacteria show excellent performance of targeted transportation and directional deposition of CaCO3 in microfluidic chip. • The emergence of artificial magnetic bacteria promotes paradigm shift of next generation environmentally friendly biomineralization.
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Affiliation(s)
- Shiqing Wang
- Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education, Hunan University, Changsha, 410082, China
- Research Center for Advanced Underground, Space Technologies of Hunan University, Changsha, 410082, China
- College of Civil Engineering, Hunan University, Changsha, 410082, China
| | - Yongqing Chen
- Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education, Hunan University, Changsha, 410082, China
- Research Center for Advanced Underground, Space Technologies of Hunan University, Changsha, 410082, China
- College of Civil Engineering, Hunan University, Changsha, 410082, China
- A School of Transportation Engineering, East China Jiaotong University, Nanchang Jiangxi 330013, China
| | - Renpeng Chen
- Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education, Hunan University, Changsha, 410082, China
- Research Center for Advanced Underground, Space Technologies of Hunan University, Changsha, 410082, China
- College of Civil Engineering, Hunan University, Changsha, 410082, China
| | - Xiongying Ma
- Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education, Hunan University, Changsha, 410082, China
- Research Center for Advanced Underground, Space Technologies of Hunan University, Changsha, 410082, China
- College of Civil Engineering, Hunan University, Changsha, 410082, China
| | - Xin Kang
- Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education, Hunan University, Changsha, 410082, China.
- Research Center for Advanced Underground, Space Technologies of Hunan University, Changsha, 410082, China.
- College of Civil Engineering, Hunan University, Changsha, 410082, China.
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Zhang L, Wang H, Wu A, Yang K, Zhang X, Guo J. Effect of flocculant dosage on the settling properties and underflow concentration of thickener for flocculated tailing suspensions. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2023; 88:304-320. [PMID: 37452549 PMCID: wst_2023_191 DOI: 10.2166/wst.2023.191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
Flocculation is important in the thickening process to improve the underflow concentration in thickeners for tailing suspensions. Traditional zone settling velocity (ZSV) functions ignore the effect of flocculant dosage on the ZSV and the thickening behavior of thickeners. To investigate the effect of flocculant dosage on the settling flux function, a series of batch settling tests were conducted at various flocculant dosages for unclassified and fine tailings. The correlation among flocculant dosage, solid fraction, and parameters in the ZSV function was revealed. Moreover, a simulation of continuous thickening based on the ZSV function was performed. Results indicated that flocculation influenced settling velocity and floc density. With an increased flocculant dosage, the settling velocity of floc increased, resulting in increased underflow concentration. Conversely, floc density decreased due to a stronger particle-particle interaction, leading to a decreased underflow concentration.
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Affiliation(s)
- Lianfu Zhang
- Anhui Engineering Research Center of Exploitation and Utilization of Closed/Abandoned Mine Resources, Anhui University of Science and Technology, Huainan 232001, China; School of Mining Engineering, Anhui University of Science and Technology, Huainan 232001, China; School of Civil & Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China E-mail:
| | - Hongjiang Wang
- School of Civil & Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Aixiang Wu
- School of Civil & Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Ke Yang
- School of Mining Engineering, Anhui University of Science and Technology, Huainan 232001, China
| | - Xi Zhang
- School of Civil & Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Jiabin Guo
- School of Civil & Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China
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Li Y, Ma X, Chen Y, Kang X, Yang B. Superhydrophobicity Mechanism and Nanoscale Profiling of PDMS-Modified Kaolinite Nanolayers via Ab Initio-MD Simulation and Atomic Force Microscopy Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023. [PMID: 37289639 DOI: 10.1021/acs.langmuir.3c00915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
This study aimed to investigate the superhydrophobic mechanism of kaolinite particles modified with poly(dimethylsiloxane) (PDMS), which has potential as a superior hydrophobic coating. The study employed a combination of density functional theory (DFT) simulation modeling, characterization of the chemical properties and microstructure, contact angle measurements, and chemical force spectroscopy of atomic force microscopy. The results showed successful PDMS grafting onto the kaolinite surface, resulting in micro- and nanoscale roughness and a contact angle of 165°, indicating a successful superhydrophobic effect. The study also identified the mechanism of the hydrophobic interaction through two-dimensional micro- and nanoscale hydrophobicity images, highlighting the potential of this approach for developing new hydrophobic coatings.
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Affiliation(s)
- Yi Li
- Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education, Hunan University, Changsha 410082, China
- National Center for International Research Collaboration in Building Safety and Environment, Hunan University, Changsha 410082, China
- College of Civil Engineering, Hunan University, Changsha 410082, China
| | - Xiongying Ma
- Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education, Hunan University, Changsha 410082, China
- National Center for International Research Collaboration in Building Safety and Environment, Hunan University, Changsha 410082, China
- College of Civil Engineering, Hunan University, Changsha 410082, China
| | - Yongqing Chen
- Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education, Hunan University, Changsha 410082, China
- National Center for International Research Collaboration in Building Safety and Environment, Hunan University, Changsha 410082, China
- College of Civil Engineering, Hunan University, Changsha 410082, China
| | - Xin Kang
- Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education, Hunan University, Changsha 410082, China
- National Center for International Research Collaboration in Building Safety and Environment, Hunan University, Changsha 410082, China
- College of Civil Engineering, Hunan University, Changsha 410082, China
| | - Bin Yang
- College of Materials Science and Engineering, Hunan University, Changsha 410082, China
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Lotfiman S, Bhattacharya S, Parthasarathy R. Novel method of measuring solids settling velocity in concentrated slurry under sheared conditions using electrical resistance tomography (ERT). Chem Eng Sci 2022. [DOI: 10.1016/j.ces.2022.118297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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7
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Panda SK, Mishra VK, Vishnu Anand P, Rajeev R, Venkatesan K, Ananthasivan K. Investigating sedimentation process in the plutonium reconversion using Eulerian Two-Fluid simulations and experimental verification. NUCLEAR ENGINEERING AND DESIGN 2022. [DOI: 10.1016/j.nucengdes.2022.111955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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8
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Lotfiman S, Bhattacharya S, Parthasarathy R. A novel approach for measuring particle settling and settled bed build-up velocities in concentrated slurries using electrical resistance tomography. POWDER TECHNOL 2022. [DOI: 10.1016/j.powtec.2022.117938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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9
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Stable Magnetorheological Fluids Containing Bidisperse Fillers with Compact/Mesoporous Silica Coatings. Int J Mol Sci 2022; 23:ijms231911044. [PMID: 36232347 PMCID: PMC9570470 DOI: 10.3390/ijms231911044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/08/2022] [Accepted: 09/17/2022] [Indexed: 11/16/2022] Open
Abstract
A drawback of magnetorheological fluids is low kinetic stability, which severely limits their practical utilization. This paper describes the suppression of sedimentation through a combination of bidispersal and coating techniques. A magnetic, sub-micro additive was fabricated and sequentially coated with organosilanes. The first layer was represented by compact silica, while the outer layer consisted of mesoporous silica, obtained with the oil–water biphase stratification method. The success of the modification technique was evidenced with transmission electron microscopy, scanning electron microscopy/energy-dispersive X-ray spectroscopy and Fourier-transform infrared spectroscopy. The coating exceptionally increased the specific surface area, from 47 m2/g (neat particles) up to 312 m2/g, which when combined with lower density, resulted in remarkable improvement in the sedimentation profile. At this expense, the compact/mesoporous silica slightly diminished the magnetization of the particles, while the magnetorheological performance remained at an acceptable level, as evaluated with a modified version of the Cross model. Sedimentation curves were, for the first time in magnetorheology, modelled via a novel five-parameter equation (S-model) that showed a robust fitting capability. The sub-micro additive prevented the primary carbonyl iron particles from aggregation, which was projected into the improved sedimentation behavior (up to a six-fold reduction in the sedimentation rate). Detailed focus was also given to analyze the implications of the sub-micro additives and their surface texture on the overall behavior of the bidisperse magnetorheological fluids.
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Fang YG, Liu H, Guo LF, Li XL, Wang PX, Gu RG. Calculation theory and experiment verification of sedimentation potential of the complex particle system. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.129447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Panda SK, Anand PV, Rajeev RP, Venkatesan KA, Ananthasivan K. Experimental investigation of sedimentation behaviour using cerium oxalate particles in oxalic‐nitric acid medium. ASIA-PAC J CHEM ENG 2021. [DOI: 10.1002/apj.2731] [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)
- Saroj Kumar Panda
- Reprocessing Research and Development Division Reprocessing Group, Indira Gandhi Centre for Atomic Research Kalpakkam India
| | - Panantharayil Vishnu Anand
- Reprocessing Research and Development Division Reprocessing Group, Indira Gandhi Centre for Atomic Research Kalpakkam India
| | - Ramachandran Pillai Rajeev
- Reprocessing Research and Development Division Reprocessing Group, Indira Gandhi Centre for Atomic Research Kalpakkam India
| | - Konda Athmaram Venkatesan
- Reprocessing Research and Development Division Reprocessing Group, Indira Gandhi Centre for Atomic Research Kalpakkam India
| | - Krishnamurthy Ananthasivan
- Reprocessing Research and Development Division Reprocessing Group, Indira Gandhi Centre for Atomic Research Kalpakkam India
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Ghazali MEB, Adachi Y. Container size effects on the validity for the concept of sedimentation turbulence studied using coagulated suspension of Na-montmorillonite in the semi-dilute regime. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2021.127567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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13
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Removal of Fe(III), Cd(II), and Zn(II) as Hydroxides by Precipitation–Flotation System. SUSTAINABILITY 2021. [DOI: 10.3390/su132111913] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this paper, a combined precipitation–flotation system is proposed for the removal of Fe(III), Zn(II), and Cd(II) as hydroxides. The efficiency of precipitation, as a function of pH, metal ion concentration, and dosage of the precipitating agent as the main variables, was evaluated. The results showed that 99% efficiency was attained from a mixture solution containing the three metal ions in sulfate media at pH 10.3 after 15 min of treatment. The sedimentation behavior showed that a larger precipitate facilitated solid/liquid separation at 30 min. The characterization of precipitates was performed by X-ray diffraction (XRD) identifying iron, zinc, and cadmium oxides; hydroxides; and sodium sulfate. For the flotation, a 20 mg/L solution of dodecylamine (DDA) was used as a collector. Such a solution allowed for the removal of 76% of precipitates in concentrate. An increase in the collector concentration diminished the float percentage due to the micelle formation and low adsorption of the collector on the surface of the precipitate. The results provide evidence of the effectivity of the removal of metal ions by the combined precipitation–flotation system as an alternative for the treatment of acid mine drainage (AMD) in less time in comparison with a sedimentation stage.
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Disengagement of dispersed cerium oxalate from nitric-oxalic acid medium in a batch settler: Measurements and CFD simulations. ANN NUCL ENERGY 2020. [DOI: 10.1016/j.anucene.2020.107574] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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15
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Zhou Z, Fang L, Cao Y, Wang W, Wang J, Yang Y, Liu Y. Determination of Hansen solubility parameters of halloysite nanotubes and prediction of its compatibility with polyethylene oxide. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2020.125031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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16
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Wang J, Kang X, Peng C. Modelling and Experimental Investigation on the Settling Rate of Kaolinite Particles in Non-Ideal Sedimentation Stage under Constant Gravity. MATERIALS (BASEL, SWITZERLAND) 2020; 13:ma13173785. [PMID: 32867228 PMCID: PMC7504239 DOI: 10.3390/ma13173785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 08/07/2020] [Accepted: 08/21/2020] [Indexed: 06/11/2023]
Abstract
We compared the catalytic effects of two polymers (soluble starch and apple pectin) on the flocculation of kaolinite suspension. Moreover, the relationship between the zeta potential value and the time when kaolin particle sedimentation occurred was verified, and the mechanism of flocculation was analyzed. Additionally, a constitutive model was proposed to simulate the non-ideal sedimentation of clay particles in an aqueous system under constant gravity. This model not only considers the inhomogeneity of the solute but also simulates the change in clay concentration with time during the deposition process. This model proposes a decay constant (α) and sedimentation coefficient (s). The model can also be used to calculate the instantaneous sedimentation rate of the clay suspensions at any time and any depth for the settling cylinder. These sedimentary characteristics were simulated by adopting the established deposition model. The results show that the model is capable of predicting the time required for the complete sedimentation of particles in the aqueous system, suggesting the feasibility of engineering wastewater treatment, site dredging, etc.
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Affiliation(s)
- Jianfu Wang
- College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China;
| | - Xin Kang
- College of Civil Engineering, Hunan University, Changsha 410012, China
- College of Civil Engineering, China Three Gorges University, Yichang 443002, China
| | - Chunyin Peng
- College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China;
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