Lockwood, APG orcid.org/0000-0002-2111-6753, Peakall, J orcid.org/0000-0003-3382-4578, Warren, NJ orcid.org/0000-0002-8298-1417 et al. (4 more authors) (2021) Structure and sedimentation characterisation of sheared Mg(OH)2 suspensions flocculated with anionic polymers. Chemical Engineering Science, 231. 116274. ISSN 0009-2509
Abstract
In this study, magnesium hydroxide (Mg(OH)2) suspensions were flocculated using two polyacrylamide-poly(acrylic acid) copolymers with charge densities of 30% or 40%. Structural characteristics, including particle size distribution, shape and fractal dimension of the resultant flocs were investigated using complementary techniques; static light scattering, focused beam reflectance measurement, automated optical microscopy and cryogenic scanning electron microscopy. Sedimentation rates were analysed for 2.5 vol.% dispersions at various polymer concentrations and compared to predictions from a fractal modified Richardson-Zaki (FMRZ) settling model. FMRZ model predictions using the 90th percentile (d90) floc sizes produced the most accurate correlations to experimental settling data, as these larger flocs likely dominate settling dynamics by ‘netting’ smaller particles. Overall, the FMRZ settling model provided a first approximation of zonal settling rates, but when further examined by multivariate analysis, was found to be critically sensitive to small changes in fractal dimension.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 The Authors. This is an open access article under the terms of the Creative Commons Attribution 4.0 International License (CC BY 4.0) (https://creativecommons.org/licenses/by/4.0/) |
Keywords: | Flocculation; Anionic polymers; Extended Stokes; Sedimentation modelling; Hindered settling |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Institute for Applied Geosciences (IAG) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 06 May 2021 10:27 |
Last Modified: | 08 Jan 2025 14:57 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.ces.2020.116274 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:163809 |