Internal fouling during microfiltration with foulants of different surface charges

In view of the inevitability of membrane fouling, it is critically important to understand the underlying mechanisms to alleviate fouling and thereby improve the feasibility of membrane-filtration for more applications. This study was targeted at understanding the internal membrane fouling mechanism...

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Main Authors: Trinh, Thien An, Li, Weiyi, Chew, Jia Wei
Other Authors: School of Chemical and Biomedical Engineering
Format: Article
Language:English
Published: 2022
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Online Access:https://hdl.handle.net/10356/155518
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1555182022-03-07T06:00:25Z Internal fouling during microfiltration with foulants of different surface charges Trinh, Thien An Li, Weiyi Chew, Jia Wei School of Chemical and Biomedical Engineering Nanyang Environment and Water Research Institute Singapore Membrane Technology Centre Engineering::Bioengineering Membrane Fouling Optical Coherence Tomography In view of the inevitability of membrane fouling, it is critically important to understand the underlying mechanisms to alleviate fouling and thereby improve the feasibility of membrane-filtration for more applications. This study was targeted at understanding the internal membrane fouling mechanisms by three types of polystyrene (PS) particles (sized at ~ 0.45 μm; different surface charges) during microfiltration with the same polycarbonate track-etched (PCTE) membrane (nominal pore size of 2 μm). Optical coherence tomography (OCT) technique, which was employed to monitor membrane fouling, indicated greater extents of particle deposition in the case of the positive and less negative PS particles, which is consistent with the more severe flux declines relative to the more negative PS particles. The new fouling model developed that additionally accounts for internal cake filtration, on top of the well-reported pore constriction and pore blockage, revealed the fouling mechanisms at play. For the positive PS particles, the attractive particle-membrane interaction led to a more homogeneous layer-by-layer cake growth, which resulted in denser packing in the pore and higher internal cake resistance, and thereby the worst flux decline. In contrast, for the negative PS particles, the repulsive particle-particle and particle-membrane interactions resulted in more random deposition of the particles inside the pores, resulting in more extensive pore constriction and blockage, as well as lower resistance of the internal cake. This study underscored the importance of surface charge in internal fouling and provided insights on the lesser reported internal fouling mechanisms. Economic Development Board (EDB) Ministry of Education (MOE) We acknowledge funding from the GSK (GlaxoSmithKline) – EDB (Economic Development Board) Trust Fund and Singapore Ministry of Education Tier 1 (2019-T1-002-065). We also acknowledge Yunqiao Ma and Qi Han for their involvement in discussions about the model, Huang Teik Lay for his help in characterization measurements. 2022-03-07T06:00:25Z 2022-03-07T06:00:25Z 2020 Journal Article Trinh, T. A., Li, W. & Chew, J. W. (2020). Internal fouling during microfiltration with foulants of different surface charges. Journal of Membrane Science, 602, 117983-. https://dx.doi.org/10.1016/j.memsci.2020.117983 0376-7388 https://hdl.handle.net/10356/155518 10.1016/j.memsci.2020.117983 2-s2.0-85079626140 602 117983 en 2019-T1-002-065 Journal of Membrane Science © 2020 Elsevier B.V. All rights reserved.
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Engineering::Bioengineering
Membrane Fouling
Optical Coherence Tomography
spellingShingle Engineering::Bioengineering
Membrane Fouling
Optical Coherence Tomography
Trinh, Thien An
Li, Weiyi
Chew, Jia Wei
Internal fouling during microfiltration with foulants of different surface charges
description In view of the inevitability of membrane fouling, it is critically important to understand the underlying mechanisms to alleviate fouling and thereby improve the feasibility of membrane-filtration for more applications. This study was targeted at understanding the internal membrane fouling mechanisms by three types of polystyrene (PS) particles (sized at ~ 0.45 μm; different surface charges) during microfiltration with the same polycarbonate track-etched (PCTE) membrane (nominal pore size of 2 μm). Optical coherence tomography (OCT) technique, which was employed to monitor membrane fouling, indicated greater extents of particle deposition in the case of the positive and less negative PS particles, which is consistent with the more severe flux declines relative to the more negative PS particles. The new fouling model developed that additionally accounts for internal cake filtration, on top of the well-reported pore constriction and pore blockage, revealed the fouling mechanisms at play. For the positive PS particles, the attractive particle-membrane interaction led to a more homogeneous layer-by-layer cake growth, which resulted in denser packing in the pore and higher internal cake resistance, and thereby the worst flux decline. In contrast, for the negative PS particles, the repulsive particle-particle and particle-membrane interactions resulted in more random deposition of the particles inside the pores, resulting in more extensive pore constriction and blockage, as well as lower resistance of the internal cake. This study underscored the importance of surface charge in internal fouling and provided insights on the lesser reported internal fouling mechanisms.
author2 School of Chemical and Biomedical Engineering
author_facet School of Chemical and Biomedical Engineering
Trinh, Thien An
Li, Weiyi
Chew, Jia Wei
format Article
author Trinh, Thien An
Li, Weiyi
Chew, Jia Wei
author_sort Trinh, Thien An
title Internal fouling during microfiltration with foulants of different surface charges
title_short Internal fouling during microfiltration with foulants of different surface charges
title_full Internal fouling during microfiltration with foulants of different surface charges
title_fullStr Internal fouling during microfiltration with foulants of different surface charges
title_full_unstemmed Internal fouling during microfiltration with foulants of different surface charges
title_sort internal fouling during microfiltration with foulants of different surface charges
publishDate 2022
url https://hdl.handle.net/10356/155518
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