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Hayami MF, Menju T, Ide T, Uchida T, Adachi Y. Growth of Floc Structure and Subsequence Compaction into Smaller Granules through Breakup and Rearrangement of Aluminum Flocs in a Constant Laminar Shear Flow. Gels 2024; 10:49. [PMID: 38247772 PMCID: PMC10815830 DOI: 10.3390/gels10010049] [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: 12/04/2023] [Revised: 01/01/2024] [Accepted: 01/03/2024] [Indexed: 01/23/2024] Open
Abstract
We have constructed an outer-cylinder-rotating Couette device for high-speed shear flow in laminar flow conditions and visualized the structure formation and subsequent rearrangement of PACl (flocculant made of aluminum hydroxide gel) and kaolinite flocs by visible light imaging. In a previous report, we analyzed the case of relatively low shear rate (G-value = 29 1/s) and confirmed that the flocculation process could be separated into two stages: a floc growth stage and a breakup/rearrangement stage. Once the large bulky flocs that reached the maximum size appeared, they rearranged and densified through structural fracture and rearrangement. In this report, this process was further investigated by conducting experiments under two different high shear rates (58 and 78 1/s) at which breakup and rearrangement became more pronounced, and three different aluminum kaolinite ratios (ALT ratios) that were over and under the optimum dosage (neutralization point by Zeta potential). Visualization results confirmed that, during the growth stage, the flocculation rate could be approximated by a scaling relationship between floc size and elapsed time, which depended on the ALT ratio. After reaching the maximum size, the floc rapidly became compact and dense following adsorption of the gel, incorporating fine fragments from erosion breakup. The over and under dosages created a lot of fragments of erosion breakup, but less so in the optimum dosage. In the optimum ALT ratio, fragments did not remain because they were incorporated into the flocs and densified, and the floc size was thought to be maintained. The floc circularity distribution peaked at around 0.6 and 1, suggesting that the flocs were spherical in shape due to erosion breakup.
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Affiliation(s)
- Mii Fukuda Hayami
- Infrastructure Systems Research and Development Center, Toshiba Infrastructure Systems & Solutions Corporation, 1, Toshiba, Fuchu 183-8511, Tokyo, Japan
| | - Takashi Menju
- Infrastructure Systems Research and Development Center, Toshiba Infrastructure Systems & Solutions Corporation, 1, Toshiba, Fuchu 183-8511, Tokyo, Japan
| | - Takeshi Ide
- Infrastructure Systems Research and Development Center, Toshiba Infrastructure Systems & Solutions Corporation, 1, Toshiba, Fuchu 183-8511, Tokyo, Japan
| | - Tatsuro Uchida
- Energy Systems Research and Development Center, Toshiba Energy Systems & Solutions Corporation, 1-20, Kansei, Tsurumi, Yokohama 230-0034, Kanagawa, Japan
| | - Yasuhisa Adachi
- Faculty of Life and Environmental Science, University of Tsukuba, 1-1-1, Tennodai, Tsukuba 305-8572, Ibaraki, Japan;
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Lee H, Park J, Cho H, Lee J, Lee KH. Investigation of shear-induced rearrangement of carbon nanotube bundles using Taylor-Couette flow. RSC Adv 2021; 11:38152-38160. [PMID: 35498094 PMCID: PMC9044060 DOI: 10.1039/d1ra07354k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Accepted: 11/22/2021] [Indexed: 01/21/2023] Open
Abstract
Macroscopic assemblies of carbon nanotubes (CNTs) usually have a poor alignment and a low packing density due to their hierarchical structure. To realize the inherent properties of CNTs at the macroscopic scale, the CNT assemblies should have a highly aligned and densified structure. Shear-aligning processes are commonly employed for this purpose. This work investigates how shear flows affect the rearrangement of CNT bundles in macroscopic assemblies. We propose that buckling behavior of CNT bundles in a shear flow causes the poor alignment of CNT bundles and a low packing density of CNT assemblies; the flow pattern and the magnitude of shear stress induced by the flow are key factors to regulate this buckling behavior. To obtain CNT assemblies with a high packing density, the CNTs should undergo a laminar flow that has a sufficiently low shear stress. Understanding the effect of shear flow on the structure of CNT bundles may guide improvement of fabrication strategies. The rearrangement of CNT bundles depends on the flow pattern and flow-induced shear stress. When the Taylor–Couette flow is stable and laminar, and has sufficiently low shear stress, CNT assemblies assume a highly aligned and densified structure.![]()
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Affiliation(s)
- Haemin Lee
- Department of Chemical Engineering, Pohang University of Science and Technology 77 Cheongam-Ro, Nam-gu Pohang Gyeongbuk 37673 Republic of Korea +82-54-279-2003
| | - Jinhwan Park
- Department of Chemical Engineering, Pohang University of Science and Technology 77 Cheongam-Ro, Nam-gu Pohang Gyeongbuk 37673 Republic of Korea +82-54-279-2003
| | - Hyunjung Cho
- LG Chem R&D Campus Daejeon 188 Munji-ro, Yuseong-gu Daejeon 34122 South Korea
| | - Jaegeun Lee
- School of Chemical Engineering, Pusan National University 2 Busandaehak-ro 63 Beon-gil, Geumjeong-gu Busan 46241 Republic of Korea +82-51-510-2495
| | - Kun-Hong Lee
- Department of Chemical Engineering, Pohang University of Science and Technology 77 Cheongam-Ro, Nam-gu Pohang Gyeongbuk 37673 Republic of Korea +82-54-279-2003
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Frungieri G, Vanni M. Aggregation and breakup of colloidal particle aggregates in shear flow: A combined Monte Carlo - Stokesian dynamics approach. POWDER TECHNOL 2021. [DOI: 10.1016/j.powtec.2021.04.076] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Lartiges B, El Samrani AG, Montargès-Pelletier E, Bihannic I, Briois V, Michot L. Aggregating ability of ferric chloride in the presence of phosphate ligand. WATER RESEARCH 2019; 164:114960. [PMID: 31408758 DOI: 10.1016/j.watres.2019.114960] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 08/02/2019] [Accepted: 08/06/2019] [Indexed: 06/10/2023]
Abstract
Complexing anions such as phosphate or silicate play an ambivalent role in the performance of hydrolyzing metal coagulants: On one hand, they significantly interfere with the hydrolytic pathway of conventional iron or aluminum coagulants, the associated destabilization mechanism remaining rather elusive; on the other hand, they have been shown to be key ingredients in the formulation of innovative coagulant solutions exhibiting improved removal efficiency, their action mechanism at the molecular scale being presently poorly understood. In this paper, we explore the effect of small additions of phosphate ligand on the chemical coagulation of silica nanoparticles with ferric chloride. Transmission Electron Microscopy-Energy Dispersed X-ray Spectroscopy (TEM-EDXS) combined with Extended X-ray absorption Fine Structure Spectroscopy (EXAFS) at the Fe K-edge are used to provide an insight into the nature of coagulant species, whereas jar-tests, laser diffraction, Small Angle X-ray Scattering (SAXS), and electrophoretic mobility, are used to investigate the aggregation dynamics of silica particles in the presence of phosphate ligand. We show that, in spite of a slight increase in the consumption of iron coagulant, the addition of phosphate significantly improves the formation of silica aggregates provided that the elemental Fe/P ratio remains above 7. Such effects originate from both a large increase in the overall number of coagulant species, the binding of a phosphate ligand terminating the growth of polymeric chains of edge-sharing Fe octahedra, and a change in the nature of the coagulant species that evolves with the Fe/P ratio, small polycations built-up from Fe-oligomers linked by phosphate tetrahedra being eventually formed. Those non-equilibrium nanosize Fe-P coagulant species assemble the silica nanoparticles to form hetero-aggregates whose structure is consistent with a Diffusion-Limited Cluster Aggregation mechanism.
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Affiliation(s)
- B Lartiges
- University of Toulouse (Paul Sabatier), Geosciences Environment Toulouse (UMR CNRS-UPS 5563 IRD 234), 14 Av. E. Belin, 31400, Toulouse, France.
| | - A G El Samrani
- Lebanese University, Platform for Research and Analysis in Environmental Sciences, Doctoral School of Science and Technology, Faculty of Sciences, P.O Box. 5, Campus Rafic Hariri, Beirut, Lebanon.
| | - E Montargès-Pelletier
- University of Lorraine, LIEC (Laboratoire Interdisciplinaire des Environnements Continentaux), UMR CNRS 7360, 54501, Vandoeuvre-les-Nancy, France
| | - I Bihannic
- University of Lorraine, LIEC (Laboratoire Interdisciplinaire des Environnements Continentaux), UMR CNRS 7360, 54501, Vandoeuvre-les-Nancy, France
| | - V Briois
- SOLEIL Synchrotron, UR1-CNRS, l'Orme des Merisiers, BP 48, Saint-Aubin, 91192, Gif-sur-Yvette, France
| | - L Michot
- Laboratoire PHENIX CNRS Sorbonne Université UMR 8234, 4 Place Jussieu, 72522, Paris Cedex 5, France
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Size, orientation, and strength of Na-montmorillonite flocs flowing in a laminar shear flow. Colloid Polym Sci 2019. [DOI: 10.1007/s00396-019-04532-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Fractal dimensions and morphological characteristics of aggregates formed in different physico-chemical and mechanical flocculation environments. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2018.10.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Frungieri G, Vanni M. Shear-induced aggregation of colloidal particles: A comparison between two different approaches to the modelling of colloidal interactions. CAN J CHEM ENG 2017. [DOI: 10.1002/cjce.22843] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Graziano Frungieri
- Department of Applied Science and Technology; Politecnico di Torino; Corso Duca degli Abruzzi 24 10129 Torino Italy
| | - Marco Vanni
- Department of Applied Science and Technology; Politecnico di Torino; Corso Duca degli Abruzzi 24 10129 Torino Italy
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Vlieghe M, Frances C, Coufort‐Saudejaud C, Liné A. Morphological properties of flocs under turbulent break‐up and restructuring processes. AIChE J 2017. [DOI: 10.1002/aic.15745] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- M. Vlieghe
- Laboratoire de Génie ChimiqueUniversité de Toulouse, CNRS, INPT, UPSToulouse France
- LISBP, Université de Toulouse, CNRS, INRA, INSAToulouse France
| | - C. Frances
- Laboratoire de Génie ChimiqueUniversité de Toulouse, CNRS, INPT, UPSToulouse France
| | - C. Coufort‐Saudejaud
- Laboratoire de Génie ChimiqueUniversité de Toulouse, CNRS, INPT, UPSToulouse France
| | - A. Liné
- LISBP, Université de Toulouse, CNRS, INRA, INSAToulouse France
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Sieliechi J, Lartiges B, Skali-Lami S, Kayem J, Kamga R. Floc compaction during ballasted aggregation. WATER RESEARCH 2016; 105:361-369. [PMID: 27643750 DOI: 10.1016/j.watres.2016.09.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 09/08/2016] [Accepted: 09/09/2016] [Indexed: 06/06/2023]
Abstract
Ballasted aggregation, a process using the addition of a ballasting agent to improve the settling performance of flocs, appears particularly appropriate for the treatment of humic rich waters that leads to low-density aggregates. In that context, using an aquagenic humic acid coagulated by ferric chloride in the presence of pozzolana particles as ballasting agent, we show that the origin of improved floc settling in ballasted aggregation is not simply related to an increased specific weight of flocs, but also to a significant restructuring of flocs to a more compact structure induced by the added particles. The floc restructuring is evidenced from the increased lag time before measurable floc growth in the presence of the ballasting agent, the higher fractal dimension of flocs above the micron scale range after incorporation of the particles into the aggregates, and a much smaller sediment volume after settling. A simple model of floc compaction based on the turbulent viscous effects that act on an elastic floc, is described.
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Affiliation(s)
- J Sieliechi
- ENSAIT-IUT, University of Ngaoudere, P.O. Box 455, Cameroon.
| | - B Lartiges
- University of Toulouse (Paul Sabatier), Geosciences Environment Toulouse, UMR CNRS-UPS 5563, 14 Av. Edouard Belin, 31400, Toulouse, France.
| | - S Skali-Lami
- University of Lorraine, LEMTA-ENSEM/INPL-CNRS, 2 Avenue de la Forêt de Haye, BP 160, 54504, Vandoeuvre Cedex, France
| | - J Kayem
- ENSAIT-IUT, University of Ngaoudere, P.O. Box 455, Cameroon
| | - R Kamga
- ENSAIT-IUT, University of Ngaoudere, P.O. Box 455, Cameroon
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Vlieghe M, Coufort-Saudejaud C, Frances C, Liné A. In situcharacterization of floc morphology by image analysis in a turbulent Taylor-Couette reactor. AIChE J 2014. [DOI: 10.1002/aic.14431] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Mélody Vlieghe
- Université de Toulouse; INPT; UPS; LGC, 4, Allée Emile Monso F-31030 Toulouse France
- CNRS; Laboratoire de Génie Chimique; F-31030 Toulouse France
- Université de Toulouse; INSA; UPS, INP; LISBP, 135 Avenue de Rangueil F-31077 Toulouse France
- INRA; UMR792 Ingénierie des Systèmes Biologiques et des Procédés; F-31400 Toulouse France
- CNRS; UMR5504 F-31400 Toulouse France
| | - Carole Coufort-Saudejaud
- Université de Toulouse; INPT; UPS; LGC, 4, Allée Emile Monso F-31030 Toulouse France
- CNRS; Laboratoire de Génie Chimique; F-31030 Toulouse France
| | - Christine Frances
- Université de Toulouse; INPT; UPS; LGC, 4, Allée Emile Monso F-31030 Toulouse France
- CNRS; Laboratoire de Génie Chimique; F-31030 Toulouse France
| | - Alain Liné
- Université de Toulouse; INSA; UPS, INP; LISBP, 135 Avenue de Rangueil F-31077 Toulouse France
- INRA; UMR792 Ingénierie des Systèmes Biologiques et des Procédés; F-31400 Toulouse France
- CNRS; UMR5504 F-31400 Toulouse France
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Heinson WR, Sorensen CM, Chakrabarti A. Shear history independence in colloidal aggregation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:11337-11342. [PMID: 22794190 DOI: 10.1021/la302010e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Stimulated by experiments, we have carried out detailed simulations of aggregation in the presence of shear in a model colloidal system with a short-range attractive potential. For weak shear rates, we find that the shear enhanced the aggregation and that the long-time state of the system is independent of the shear history. For strong shear rates, precipitous fragmentation occurred after the shear was turned on and, after an induction period, the aggregation quickly rebounded in a stochastic manner similar to classical nucleation phenomena. However, the long-time state of the system is, once again, independent of the shear history. Thus, for both weak and strong shear cases, the shear rate acts as a state variable of the aggregating system. Shear rates employed in the simulations can be attained in laboratory experiments, as confirmed by computing the dimensionless Péclet numbers.
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Affiliation(s)
- William R Heinson
- Department of Physics, Kansas State University, Manhattan, Kansas 66506, United States
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