Characterization of colloidal fouling in forward osmosis via ultrasonic time - (UTDR) and frequency-domain reflectometry (UFDR)
Ultrasonic time- (UTDR) and frequency-domain reflectometry (UFDR) were applied to characterize internal and external fouling in the forward osmosis (FO) process. Unlike RO applications, in which the transducer was placed above the membrane to detect external fouling on the top surface of membrane, t...
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sg-ntu-dr.10356-1555192022-03-07T06:30:35Z Characterization of colloidal fouling in forward osmosis via ultrasonic time - (UTDR) and frequency-domain reflectometry (UFDR) Lai, Li Sim, Lee Nuang Krantz, William B. Chong, Tzyy Haur School of Civil and Environmental Engineering Nanyang Environment and Water Research Institute Singapore Membrane Technology Centre Engineering::Civil engineering External Fouling Internal Fouling Ultrasonic time- (UTDR) and frequency-domain reflectometry (UFDR) were applied to characterize internal and external fouling in the forward osmosis (FO) process. Unlike RO applications, in which the transducer was placed above the membrane to detect external fouling on the top surface of membrane, the transducer was placed below the membrane to enable detection of internal and external fouling in an FO application. The amplitude changes and arrival-time shifts in UTDR were more sensitive than the flux decline as an indicator of FO fouling. In the active-layer facing the feed solution (AL-FS) mode, the cake-layer thickness obtained via the differential UTDR signal agreed well with the mass-balance data. The Short-Time-Fourier-Transform (STFT) analysis permitted decomposing the non-overlapping peaks that revealed a significant decrease in the amplitudes of the high-frequency components due to the grain-scattering effect in the active-layer facing the draw solution (AL-DS) mode. In contrast, the frequency distribution remained unchanged in the AL-FS mode. The total reflected power (TRP) calculations for the arrival-times and principal peaks in the frequency-domain correlated well with the overall fouling and internal fouling, respectively. Economic Development Board (EDB) The financial support of the Economic Development Board (EDB) of Singapore to the Singapore Membrane Technology Centre (SMTC), Nanyang Environment & Water Research Institute (NEWRI) is greatly appreciated. 2022-03-07T06:30:34Z 2022-03-07T06:30:34Z 2020 Journal Article Lai, L., Sim, L. N., Krantz, W. B. & Chong, T. H. (2020). Characterization of colloidal fouling in forward osmosis via ultrasonic time - (UTDR) and frequency-domain reflectometry (UFDR). Journal of Membrane Science, 602, 117969-. https://dx.doi.org/10.1016/j.memsci.2020.117969 0376-7388 https://hdl.handle.net/10356/155519 10.1016/j.memsci.2020.117969 2-s2.0-85080066216 602 117969 en Journal of Membrane Science © 2020 Elsevier B.V. All rights reserved. |
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Engineering::Civil engineering External Fouling Internal Fouling Lai, Li Sim, Lee Nuang Krantz, William B. Chong, Tzyy Haur Characterization of colloidal fouling in forward osmosis via ultrasonic time - (UTDR) and frequency-domain reflectometry (UFDR) |
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Ultrasonic time- (UTDR) and frequency-domain reflectometry (UFDR) were applied to characterize internal and external fouling in the forward osmosis (FO) process. Unlike RO applications, in which the transducer was placed above the membrane to detect external fouling on the top surface of membrane, the transducer was placed below the membrane to enable detection of internal and external fouling in an FO application. The amplitude changes and arrival-time shifts in UTDR were more sensitive than the flux decline as an indicator of FO fouling. In the active-layer facing the feed solution (AL-FS) mode, the cake-layer thickness obtained via the differential UTDR signal agreed well with the mass-balance data. The Short-Time-Fourier-Transform (STFT) analysis permitted decomposing the non-overlapping peaks that revealed a significant decrease in the amplitudes of the high-frequency components due to the grain-scattering effect in the active-layer facing the draw solution (AL-DS) mode. In contrast, the frequency distribution remained unchanged in the AL-FS mode. The total reflected power (TRP) calculations for the arrival-times and principal peaks in the frequency-domain correlated well with the overall fouling and internal fouling, respectively. |
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School of Civil and Environmental Engineering |
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School of Civil and Environmental Engineering Lai, Li Sim, Lee Nuang Krantz, William B. Chong, Tzyy Haur |
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Article |
author |
Lai, Li Sim, Lee Nuang Krantz, William B. Chong, Tzyy Haur |
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Lai, Li |
title |
Characterization of colloidal fouling in forward osmosis via ultrasonic time - (UTDR) and frequency-domain reflectometry (UFDR) |
title_short |
Characterization of colloidal fouling in forward osmosis via ultrasonic time - (UTDR) and frequency-domain reflectometry (UFDR) |
title_full |
Characterization of colloidal fouling in forward osmosis via ultrasonic time - (UTDR) and frequency-domain reflectometry (UFDR) |
title_fullStr |
Characterization of colloidal fouling in forward osmosis via ultrasonic time - (UTDR) and frequency-domain reflectometry (UFDR) |
title_full_unstemmed |
Characterization of colloidal fouling in forward osmosis via ultrasonic time - (UTDR) and frequency-domain reflectometry (UFDR) |
title_sort |
characterization of colloidal fouling in forward osmosis via ultrasonic time - (utdr) and frequency-domain reflectometry (ufdr) |
publishDate |
2022 |
url |
https://hdl.handle.net/10356/155519 |
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1726885521049780224 |