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Seungkwan Hong - One of the best experts on this subject based on the ideXlab platform.
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effect of sulphonated polyethersulfone substrate for thin film composite forward osmosis membrane
Desalination, 2016Co-Authors: Soleyman Sahebi, Sherub Phuntsho, Seungkwan Hong, Myoung Jun Park, Leonard D Tijing, Ho Kyong ShonAbstract:Abstract Sulphonated polyethersulfone (SPES) has been synthesized for developing high performance thin film composite (TFC) forward osmosis (FO) membranes with enhanced hydrophilic support layer. Sulphonated substrate not only affects the membrane performance but also changes the membrane morphology from finger-like structure to a sponge-like morphology at higher degree of sulphonation thereby affecting the mechanical strength of the FO membrane. Non-sulphonated TFC-FO membrane with 12 wt.% polymer concentration shows a faint finger-like structure while sulphonated samples at a similar polymer concentration show a fully sponge-like structure with a much higher performance. For example, a water Flux of 35 Lm− 2 h− 1 and 0.28 g L− 1 specific reverse Solute Flux was achieved with sulphonated TFC-FO membrane sample (50 wt.% SPES) under the FO mode using 2 M NaCl as the draw solution and deionized water as feed. Substrate sulphonation also considerably decreased the membrane structural parameter from 1096 μm without sulphonation to 245 μm at 50 wt.% sulphonation. This study therefore shows that, besides surface morphology, the water Flux of the FO membrane can also be enhanced by improving its substrate hydrophilic property.
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evaluation of poly aspartic acid sodium salt as a draw Solute for forward osmosis
Water Research, 2015Co-Authors: Gimun Gwak, Bokyung Jung, Sungsoo Han, Seungkwan HongAbstract:Poly (aspartic acid sodium salt) (PAspNa) was evaluated for its potential as a novel draw Solute in forward osmosis (FO). The inherent advantages of PAspNa, such as good water solubility, high osmotic pressure, and nontoxicity, were first examined through a series of physicochemical analyses and atomic-scale molecular dynamics simulations. Then, lab-scale FO tests were performed to evaluate its suitability in practical processes. Compared to other conventional inorganic Solutes, PAspNa showed comparable water Flux but significantly lower reverse Solute Flux, demonstrating its suitability as a draw Solute. Moreover, fouling experiments using synthetic wastewater as a feed solution demonstrated that PAspNa reversely flowed to the feed side reduced inorganic scaling on the membrane active layer. The recyclability of PAspNa was studied using both nanofiltration (NF) and membrane distillation (MD) processes, and the results exhibited its ease of recovery. This research reported the feasibility and applicability of FO-NF or FO-MD processes using PAspNa for wastewater reclamation and brackish water desalination.
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Effect of hydraulic pressure and membrane orientation on water Flux and reverse Solute Flux in pressure assisted osmosis
Journal of Membrane Science, 2014Co-Authors: Yoontaek Oh, Seockheon Lee, Menachem Elimelech, Sangho Lee, Seungkwan HongAbstract:Forward osmosis (FO) is an emerging technology that has received much global interest due to its potential applications in wastewater reclamation and seawater desalination. One of the major challenges to overcome is the detrimental effects of concentration polarization (CP), which reduce the effective osmotic pressure driving force and thus decrease productivity of the FO process. In this study, pressure assisted osmosis (PAO) was investigated as a method to increase the effective driving force and water Flux by combining an osmotic pressure driving force with an additional hydraulic pressure. Experiments were carried out to examine the efficiency of the PAO process using a bench-scale setup specially designed to prevent membrane deformation under the applied hydraulic pressure. Results showed that PAO water Flux increased with increasing the applied hydraulic pressure in FO mode (i.e., active layer facing the feed solution). The measured water Fluxes were in good agreement with predictions based on a model developed to describe the water Flux in PAO operation. However, the PAO water Flux was lower than model predictions in PRO mode (i.e., active layer facing the draw solution). This observation is attributed to the spacer 'shadow effect' and the resulting reduction in the effective membrane area by the spacers. The results also showed that reverse Solute Flux decreased with increasing the applied hydraulic pressure in both FO and PRO modes. Although applying hydraulic pressure to FO increases energy consumption, the higher water Flux in PAO reduces the number of membrane modules for the FO process. In addition, control of the driving force is easier in PAO than FO, leading to flexibility in system design and operation. Based on these results, a possible combination of FO and RO system with PAO was proposed for allowing higher energy efficiency in seawater desalination. © 2014.
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boron transport in forward osmosis measurements mechanisms and comparison with reverse osmosis
Journal of Membrane Science, 2012Co-Authors: Changwoo Kim, Menachem Elimelech, Ho Kyong Shon, Sangyoup Lee, Seungkwan HongAbstract:Abstract The physical and chemical factors affecting boron Solute Flux behavior and membrane transport mechanisms in forward osmosis (FO) have been systematically investigated. Boron Solute Flux behavior in FO was further compared with that in reverse osmosis (RO) by employing identical plate-and-frame cells and membranes under the same filtration conditions. The influence of draw solution pH, draw solution type, and membrane orientation on boron Solute Flux was examined for FO, and the effects of water Flux, cross-flow velocity, feed water boron concentration, and solution pH on boron Solute Flux were examined for both FO and RO. Results show that reverse salt diffusion, a unique feature of FO, is a key mechanism governing boron Solute Flux in FO. Boron Solute Flux through the FO membrane was inversely proportional to the degree of reverse salt diffusion by draw solution. The higher boron rejection observed in FO compared to RO is also attributed to reverse salt diffusion in FO. It is also shown that membrane orientation in FO plays an important role, affecting boron Solute Flux due to different degrees of internal concentration polarization. In both FO and RO, boron Solute Flux increased with increasing water Flux. However, the influence of water Flux on boron Solute Flux was less significant in FO than RO. Furthermore, boron Solute Flux decreased with increasing feed water pH due to the conversion of the neutral boric acid to borate anions. The findings provide new insight into the mechanisms and factors controlling boron Solute transport in FO.
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a novel low energy fertilizer driven forward osmosis desalination for direct fertigation evaluating the performance of fertilizer draw solutions
Journal of Membrane Science, 2011Co-Authors: Sherub Phuntsho, Ho Kyong Shon, Seungkwan Hong, S VigneswaranAbstract:Forward osmosis (FO) is a novel and emerging low energy technology for desalination. It will be particu- larly more attractive, if the draw solution separation and recovery are not necessary after FO process. The application of this new concept is briefly described here in this paper for the desalination of saline water for irrigation, using fertilizer as a draw agent. Instead of separating the draw solution from desalinated water, the diluted fertilizer draw solution can be directly applied for fertigation. We report the results on the commonly used chemical fertilizers as FO draw solution. Based on the currently available FO tech- nology, about nine different commonly used fertilizers were finally screened from a comprehensive list of fertilizers and, their performances were assessed in terms of pure water Flux and reverse draw Solute Flux. These results indicate that, most soluble fertilizers can generate osmotic potential much higher than the sea water. The draw solutions of KCl, NaNO3 and KNO3 performed best in terms of water Flux while NH4H2PO4, (NH4)2HPO4, Ca(NO3)2 and (NH4)2SO4 had the lowest reverse Solute Flux. Initial estimation indicates that, 1 kg of fertilizer can extract water ranging from 11 to 29 L from sea water. © 2011 Elsevier B.V. All rights reserved.
Ho Kyong Shon - One of the best experts on this subject based on the ideXlab platform.
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effect of sulphonated polyethersulfone substrate for thin film composite forward osmosis membrane
Desalination, 2016Co-Authors: Soleyman Sahebi, Sherub Phuntsho, Seungkwan Hong, Myoung Jun Park, Leonard D Tijing, Ho Kyong ShonAbstract:Abstract Sulphonated polyethersulfone (SPES) has been synthesized for developing high performance thin film composite (TFC) forward osmosis (FO) membranes with enhanced hydrophilic support layer. Sulphonated substrate not only affects the membrane performance but also changes the membrane morphology from finger-like structure to a sponge-like morphology at higher degree of sulphonation thereby affecting the mechanical strength of the FO membrane. Non-sulphonated TFC-FO membrane with 12 wt.% polymer concentration shows a faint finger-like structure while sulphonated samples at a similar polymer concentration show a fully sponge-like structure with a much higher performance. For example, a water Flux of 35 Lm− 2 h− 1 and 0.28 g L− 1 specific reverse Solute Flux was achieved with sulphonated TFC-FO membrane sample (50 wt.% SPES) under the FO mode using 2 M NaCl as the draw solution and deionized water as feed. Substrate sulphonation also considerably decreased the membrane structural parameter from 1096 μm without sulphonation to 245 μm at 50 wt.% sulphonation. This study therefore shows that, besides surface morphology, the water Flux of the FO membrane can also be enhanced by improving its substrate hydrophilic property.
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performances of pa hollow fiber membrane with the cta flat sheet membrane for forward osmosis process
Desalination and Water Treatment, 2015Co-Authors: Tahir Majeed, Fezeh Lotfi, Sherub Phuntsho, Joon Khee Yoon, Kwonil Kim, Ho Kyong ShonAbstract:AbstractFertilizer drawn forward osmosis desalination has been earlier explored using flat sheet forward osmosis (FSFO) membrane, which highlighted Flux and reverse Solute Flux (RSF) performance. This study evaluated and compared the performances of a newly developed polyamide (PA)-based hollow fiber forward osmosis (HFFO) membrane and cellulose triacetate FSFO membrane. Both membranes were evaluated for pure water permeability, salt rejection rate (1,000 mg/L NaCl) in RO mode. Physical structure and morphology were further examined using scanning electron micrograph (SEM). SEM images revealed that the overall thickness of the HFFO and FSFO membranes was 152 and 91 μm, respectively. Flux and RSF performances of these two membranes were evaluated using nine fertilizer DS as NH4Cl, KNO3, KCl, (NH4)2SO4, Ca(NO3)2, NH4H2PO4, (NH4)2HPO4, NaNO3, and CO(NH2)2 in active layer–feed solution membrane orientation. HFFO membrane clearly showed better performance for water Flux with five DS ((NH4)2SO4, NH4H2PO4, KNO3,...
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boron transport in forward osmosis measurements mechanisms and comparison with reverse osmosis
Journal of Membrane Science, 2012Co-Authors: Changwoo Kim, Menachem Elimelech, Ho Kyong Shon, Sangyoup Lee, Seungkwan HongAbstract:Abstract The physical and chemical factors affecting boron Solute Flux behavior and membrane transport mechanisms in forward osmosis (FO) have been systematically investigated. Boron Solute Flux behavior in FO was further compared with that in reverse osmosis (RO) by employing identical plate-and-frame cells and membranes under the same filtration conditions. The influence of draw solution pH, draw solution type, and membrane orientation on boron Solute Flux was examined for FO, and the effects of water Flux, cross-flow velocity, feed water boron concentration, and solution pH on boron Solute Flux were examined for both FO and RO. Results show that reverse salt diffusion, a unique feature of FO, is a key mechanism governing boron Solute Flux in FO. Boron Solute Flux through the FO membrane was inversely proportional to the degree of reverse salt diffusion by draw solution. The higher boron rejection observed in FO compared to RO is also attributed to reverse salt diffusion in FO. It is also shown that membrane orientation in FO plays an important role, affecting boron Solute Flux due to different degrees of internal concentration polarization. In both FO and RO, boron Solute Flux increased with increasing water Flux. However, the influence of water Flux on boron Solute Flux was less significant in FO than RO. Furthermore, boron Solute Flux decreased with increasing feed water pH due to the conversion of the neutral boric acid to borate anions. The findings provide new insight into the mechanisms and factors controlling boron Solute transport in FO.
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a novel low energy fertilizer driven forward osmosis desalination for direct fertigation evaluating the performance of fertilizer draw solutions
Journal of Membrane Science, 2011Co-Authors: Sherub Phuntsho, Ho Kyong Shon, Seungkwan Hong, S VigneswaranAbstract:Forward osmosis (FO) is a novel and emerging low energy technology for desalination. It will be particu- larly more attractive, if the draw solution separation and recovery are not necessary after FO process. The application of this new concept is briefly described here in this paper for the desalination of saline water for irrigation, using fertilizer as a draw agent. Instead of separating the draw solution from desalinated water, the diluted fertilizer draw solution can be directly applied for fertigation. We report the results on the commonly used chemical fertilizers as FO draw solution. Based on the currently available FO tech- nology, about nine different commonly used fertilizers were finally screened from a comprehensive list of fertilizers and, their performances were assessed in terms of pure water Flux and reverse draw Solute Flux. These results indicate that, most soluble fertilizers can generate osmotic potential much higher than the sea water. The draw solutions of KCl, NaNO3 and KNO3 performed best in terms of water Flux while NH4H2PO4, (NH4)2HPO4, Ca(NO3)2 and (NH4)2SO4 had the lowest reverse Solute Flux. Initial estimation indicates that, 1 kg of fertilizer can extract water ranging from 11 to 29 L from sea water. © 2011 Elsevier B.V. All rights reserved.
Ahmad Fauzi Ismail - One of the best experts on this subject based on the ideXlab platform.
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synthesis and characterization of novel thin film nanocomposite tfn membranes embedded with halloysite nanotubes hnts for water desalination
Desalination, 2015Co-Authors: M Ghanbari, Daryoush Emadzadeh, Takeshi Matsuura, Woei Jye Lau, S O Lai, Ahmad Fauzi IsmailAbstract:Abstract In this study, a new type of thin film nanocomposite (TFN) forward osmosis (FO) membranes was prepared by incorporating different quantities of halloysite nanotubes (HNTs) into the polyamide layer via interfacial polymerization. The FO performance of all fabricated TFN membranes in terms of water permeability and reverse Solute Flux was compared and the best performing membrane which showed good balance between permeability and Solute Flux, among all, was selected for further organic fouling investigation. Using 10 mM NaCl concentration in feed solution and draw solution of 2 M NaCl, the TFN membrane that was embedded with 0.05% HNTs (i.e. TFN0.05) was identified as the best performing membrane due to its high water permeability and low reverse Solute Flux. Confirmed by the results of BSA removal in the presence of Ca 2 + , the TFN0.05 membrane also exhibited significantly higher fouling resistance compared to a typical TFC membrane. As an indication to the TFN0.05 fouling reversibility, it was found that > 96% permeate Flux could be recovered after a simple water rinse process. Overall, it can be concluded that the addition of an appropriate amount of HNTs into the polyamide layer can remarkably improve the antifouling affinity of conventional TFC membranes for FO applications.
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a novel thin film composite forward osmosis membrane prepared from psf tio2 nanocomposite substrate for water desalination
Chemical Engineering Journal, 2014Co-Authors: Daryoush Emadzadeh, Takeshi Matsuura, Masoud Rahbarisisakht, Woei Jye Lau, Ahmad Fauzi IsmailAbstract:Abstract In this work, polysulfone (PSf)–titanium dioxide (TiO2) nanocomposite substrates were prepared by incorporating different amounts of TiO2 nanoparticles (ranging from zero to 1 wt%) into PSf matrix. The nanocomposite substrates so prepared were then characterized with respect to hydrophilicity, overall porosity, surface roughness and cross-sectional morphology. It was found that both hydrophilicity and porosity of the substrate were increased upon addition of TiO2. In addition, long finger-like structures were developed by increasing the TiO2 loading, leading to water permeability enhancement. In order to fabricate thin film nanocomposite (TFN) membranes for forward osmosis (FO) application, a thin polyamide layer was formed by interfacial polymerization of 1,3-phenylendiamine and 1,3,5-benzenetricarbonyl trichloride on the top surface of PSf–TiO2 nanocomposite substrates. Under the conditions for FO performance evaluation (10 mM NaCl concentration in feed solution, 0.5 and 2.0 M NaCl concentration in draw solution, and both active layer facing the feed solution (AL–FS) and active layer facing the draw solution (AL–DS) orientations), the TFN membrane prepared using PSf substrate embedded with 0.5 wt% TiO2 nanoparticles (denoted as TFN0.5) exhibited the most promising results by showing high water permeability and low reverse Solute Flux. In comparison with control TFC membrane, the water Flux of TFN0.5 membrane was improved by 86–93%, depending on the membrane orientation and draw solution concentration. The increase in water permeability can be attributed to decrease in structural parameter which resulted in decreased internal concentration polarization (ICP). Although further increase in TiO2 nanoparticles loading to 0.75 and 1 wt% could result in higher water permeability, their FO performances were compromised by a significant increase in reverse Solute Flux. Based on the results obtained in this work, it can be concluded that adding an appropriate amount of TiO2 nanoparticles into PSf substrate could potentially improve the performance of TFC membrane during FO applications.
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synthesis and characterization of thin film nanocomposite forward osmosis membrane with hydrophilic nanocomposite support to reduce internal concentration polarization
Journal of Membrane Science, 2014Co-Authors: Daryoush Emadzadeh, Takeshi Matsuura, Ahmad Fauzi Ismail, Masoud RahbarisisakhtAbstract:Abstract Realizing that one of the most important challenges in the forward osmosis (FO) membrane is internal concentration polarization (ICP), thin film nanocomposite (TFN) membranes were prepared by incorporating different loadings of titanium dioxide (TiO 2 ) nanoparticles (ranging from 0 to 0.90 wt%) into the polysulfone (PSf) substrate in order to reduce ICP. The nanocomposite substrates prepared were characterized with respect to hydrophilicity, overall porosity, surface roughness and cross-sectional morphology by different methods. Results revealed that both hydrophilicity and porosity of the substrate were increased upon addition of TiO 2 nanoparticles. Moreover, a large number of finger-like macrovoids were developed by increasing the loading of TiO 2 nanoparticles, leading to enhancement in water permeability. As for the FO performance tested at AL-FS orientation and with DI water as feed and 0.5 M NaCl as draw solution, the TFN membrane prepared using PSf substrate embedded with 0.60 wt% TiO 2 nanoparticles (designated as TFN0.60) exhibited the most promising result by showing water Flux of 18.81 L/m 2 h, i.e. 97% higher than the control TFC membrane prepared by substrate without TiO 2 incorporation (designated as TFC), with no significant change in reverse Solute Flux. Compared to the control TFC membrane, the FO water Flux of TFN0.60 was also reported to increase significantly from 4.2 to 8.1 L/m 2 h (AL-FS orientation) and from 6.9 to 13.8 L/m 2 h (AL-DS orientation) when seawater was used as feed solution and 2 M NaCl was used as draw solution. The increase in water Flux can be attributed to the decrease in structural parameter ( S value=0.39 mm), mainly due to the formation of finger-liked macrovoids that connect the top and bottom layer of the substrate and reduce the tortuosity, resulting in decreased ICP. Although further increasing TiO 2 nanoparticles loading to 0.90 wt% could increase membrane water permeability, the FO performance was compromised by a significant increase in reverse Solute Flux. To the best knowledge of the authors, this is the first report on TFN membrane using PSf-TiO 2 nanocomposite substrate for FO applications.
Takeshi Matsuura - One of the best experts on this subject based on the ideXlab platform.
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synthesis and characterization of novel thin film nanocomposite tfn membranes embedded with halloysite nanotubes hnts for water desalination
Desalination, 2015Co-Authors: M Ghanbari, Daryoush Emadzadeh, Takeshi Matsuura, Woei Jye Lau, S O Lai, Ahmad Fauzi IsmailAbstract:Abstract In this study, a new type of thin film nanocomposite (TFN) forward osmosis (FO) membranes was prepared by incorporating different quantities of halloysite nanotubes (HNTs) into the polyamide layer via interfacial polymerization. The FO performance of all fabricated TFN membranes in terms of water permeability and reverse Solute Flux was compared and the best performing membrane which showed good balance between permeability and Solute Flux, among all, was selected for further organic fouling investigation. Using 10 mM NaCl concentration in feed solution and draw solution of 2 M NaCl, the TFN membrane that was embedded with 0.05% HNTs (i.e. TFN0.05) was identified as the best performing membrane due to its high water permeability and low reverse Solute Flux. Confirmed by the results of BSA removal in the presence of Ca 2 + , the TFN0.05 membrane also exhibited significantly higher fouling resistance compared to a typical TFC membrane. As an indication to the TFN0.05 fouling reversibility, it was found that > 96% permeate Flux could be recovered after a simple water rinse process. Overall, it can be concluded that the addition of an appropriate amount of HNTs into the polyamide layer can remarkably improve the antifouling affinity of conventional TFC membranes for FO applications.
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a novel thin film composite forward osmosis membrane prepared from psf tio2 nanocomposite substrate for water desalination
Chemical Engineering Journal, 2014Co-Authors: Daryoush Emadzadeh, Takeshi Matsuura, Masoud Rahbarisisakht, Woei Jye Lau, Ahmad Fauzi IsmailAbstract:Abstract In this work, polysulfone (PSf)–titanium dioxide (TiO2) nanocomposite substrates were prepared by incorporating different amounts of TiO2 nanoparticles (ranging from zero to 1 wt%) into PSf matrix. The nanocomposite substrates so prepared were then characterized with respect to hydrophilicity, overall porosity, surface roughness and cross-sectional morphology. It was found that both hydrophilicity and porosity of the substrate were increased upon addition of TiO2. In addition, long finger-like structures were developed by increasing the TiO2 loading, leading to water permeability enhancement. In order to fabricate thin film nanocomposite (TFN) membranes for forward osmosis (FO) application, a thin polyamide layer was formed by interfacial polymerization of 1,3-phenylendiamine and 1,3,5-benzenetricarbonyl trichloride on the top surface of PSf–TiO2 nanocomposite substrates. Under the conditions for FO performance evaluation (10 mM NaCl concentration in feed solution, 0.5 and 2.0 M NaCl concentration in draw solution, and both active layer facing the feed solution (AL–FS) and active layer facing the draw solution (AL–DS) orientations), the TFN membrane prepared using PSf substrate embedded with 0.5 wt% TiO2 nanoparticles (denoted as TFN0.5) exhibited the most promising results by showing high water permeability and low reverse Solute Flux. In comparison with control TFC membrane, the water Flux of TFN0.5 membrane was improved by 86–93%, depending on the membrane orientation and draw solution concentration. The increase in water permeability can be attributed to decrease in structural parameter which resulted in decreased internal concentration polarization (ICP). Although further increase in TiO2 nanoparticles loading to 0.75 and 1 wt% could result in higher water permeability, their FO performances were compromised by a significant increase in reverse Solute Flux. Based on the results obtained in this work, it can be concluded that adding an appropriate amount of TiO2 nanoparticles into PSf substrate could potentially improve the performance of TFC membrane during FO applications.
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synthesis and characterization of thin film nanocomposite forward osmosis membrane with hydrophilic nanocomposite support to reduce internal concentration polarization
Journal of Membrane Science, 2014Co-Authors: Daryoush Emadzadeh, Takeshi Matsuura, Ahmad Fauzi Ismail, Masoud RahbarisisakhtAbstract:Abstract Realizing that one of the most important challenges in the forward osmosis (FO) membrane is internal concentration polarization (ICP), thin film nanocomposite (TFN) membranes were prepared by incorporating different loadings of titanium dioxide (TiO 2 ) nanoparticles (ranging from 0 to 0.90 wt%) into the polysulfone (PSf) substrate in order to reduce ICP. The nanocomposite substrates prepared were characterized with respect to hydrophilicity, overall porosity, surface roughness and cross-sectional morphology by different methods. Results revealed that both hydrophilicity and porosity of the substrate were increased upon addition of TiO 2 nanoparticles. Moreover, a large number of finger-like macrovoids were developed by increasing the loading of TiO 2 nanoparticles, leading to enhancement in water permeability. As for the FO performance tested at AL-FS orientation and with DI water as feed and 0.5 M NaCl as draw solution, the TFN membrane prepared using PSf substrate embedded with 0.60 wt% TiO 2 nanoparticles (designated as TFN0.60) exhibited the most promising result by showing water Flux of 18.81 L/m 2 h, i.e. 97% higher than the control TFC membrane prepared by substrate without TiO 2 incorporation (designated as TFC), with no significant change in reverse Solute Flux. Compared to the control TFC membrane, the FO water Flux of TFN0.60 was also reported to increase significantly from 4.2 to 8.1 L/m 2 h (AL-FS orientation) and from 6.9 to 13.8 L/m 2 h (AL-DS orientation) when seawater was used as feed solution and 2 M NaCl was used as draw solution. The increase in water Flux can be attributed to the decrease in structural parameter ( S value=0.39 mm), mainly due to the formation of finger-liked macrovoids that connect the top and bottom layer of the substrate and reduce the tortuosity, resulting in decreased ICP. Although further increasing TiO 2 nanoparticles loading to 0.90 wt% could increase membrane water permeability, the FO performance was compromised by a significant increase in reverse Solute Flux. To the best knowledge of the authors, this is the first report on TFN membrane using PSf-TiO 2 nanocomposite substrate for FO applications.
Daryoush Emadzadeh - One of the best experts on this subject based on the ideXlab platform.
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synthesis and characterization of novel thin film nanocomposite tfn membranes embedded with halloysite nanotubes hnts for water desalination
Desalination, 2015Co-Authors: M Ghanbari, Daryoush Emadzadeh, Takeshi Matsuura, Woei Jye Lau, S O Lai, Ahmad Fauzi IsmailAbstract:Abstract In this study, a new type of thin film nanocomposite (TFN) forward osmosis (FO) membranes was prepared by incorporating different quantities of halloysite nanotubes (HNTs) into the polyamide layer via interfacial polymerization. The FO performance of all fabricated TFN membranes in terms of water permeability and reverse Solute Flux was compared and the best performing membrane which showed good balance between permeability and Solute Flux, among all, was selected for further organic fouling investigation. Using 10 mM NaCl concentration in feed solution and draw solution of 2 M NaCl, the TFN membrane that was embedded with 0.05% HNTs (i.e. TFN0.05) was identified as the best performing membrane due to its high water permeability and low reverse Solute Flux. Confirmed by the results of BSA removal in the presence of Ca 2 + , the TFN0.05 membrane also exhibited significantly higher fouling resistance compared to a typical TFC membrane. As an indication to the TFN0.05 fouling reversibility, it was found that > 96% permeate Flux could be recovered after a simple water rinse process. Overall, it can be concluded that the addition of an appropriate amount of HNTs into the polyamide layer can remarkably improve the antifouling affinity of conventional TFC membranes for FO applications.
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a novel thin film composite forward osmosis membrane prepared from psf tio2 nanocomposite substrate for water desalination
Chemical Engineering Journal, 2014Co-Authors: Daryoush Emadzadeh, Takeshi Matsuura, Masoud Rahbarisisakht, Woei Jye Lau, Ahmad Fauzi IsmailAbstract:Abstract In this work, polysulfone (PSf)–titanium dioxide (TiO2) nanocomposite substrates were prepared by incorporating different amounts of TiO2 nanoparticles (ranging from zero to 1 wt%) into PSf matrix. The nanocomposite substrates so prepared were then characterized with respect to hydrophilicity, overall porosity, surface roughness and cross-sectional morphology. It was found that both hydrophilicity and porosity of the substrate were increased upon addition of TiO2. In addition, long finger-like structures were developed by increasing the TiO2 loading, leading to water permeability enhancement. In order to fabricate thin film nanocomposite (TFN) membranes for forward osmosis (FO) application, a thin polyamide layer was formed by interfacial polymerization of 1,3-phenylendiamine and 1,3,5-benzenetricarbonyl trichloride on the top surface of PSf–TiO2 nanocomposite substrates. Under the conditions for FO performance evaluation (10 mM NaCl concentration in feed solution, 0.5 and 2.0 M NaCl concentration in draw solution, and both active layer facing the feed solution (AL–FS) and active layer facing the draw solution (AL–DS) orientations), the TFN membrane prepared using PSf substrate embedded with 0.5 wt% TiO2 nanoparticles (denoted as TFN0.5) exhibited the most promising results by showing high water permeability and low reverse Solute Flux. In comparison with control TFC membrane, the water Flux of TFN0.5 membrane was improved by 86–93%, depending on the membrane orientation and draw solution concentration. The increase in water permeability can be attributed to decrease in structural parameter which resulted in decreased internal concentration polarization (ICP). Although further increase in TiO2 nanoparticles loading to 0.75 and 1 wt% could result in higher water permeability, their FO performances were compromised by a significant increase in reverse Solute Flux. Based on the results obtained in this work, it can be concluded that adding an appropriate amount of TiO2 nanoparticles into PSf substrate could potentially improve the performance of TFC membrane during FO applications.
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synthesis and characterization of thin film nanocomposite forward osmosis membrane with hydrophilic nanocomposite support to reduce internal concentration polarization
Journal of Membrane Science, 2014Co-Authors: Daryoush Emadzadeh, Takeshi Matsuura, Ahmad Fauzi Ismail, Masoud RahbarisisakhtAbstract:Abstract Realizing that one of the most important challenges in the forward osmosis (FO) membrane is internal concentration polarization (ICP), thin film nanocomposite (TFN) membranes were prepared by incorporating different loadings of titanium dioxide (TiO 2 ) nanoparticles (ranging from 0 to 0.90 wt%) into the polysulfone (PSf) substrate in order to reduce ICP. The nanocomposite substrates prepared were characterized with respect to hydrophilicity, overall porosity, surface roughness and cross-sectional morphology by different methods. Results revealed that both hydrophilicity and porosity of the substrate were increased upon addition of TiO 2 nanoparticles. Moreover, a large number of finger-like macrovoids were developed by increasing the loading of TiO 2 nanoparticles, leading to enhancement in water permeability. As for the FO performance tested at AL-FS orientation and with DI water as feed and 0.5 M NaCl as draw solution, the TFN membrane prepared using PSf substrate embedded with 0.60 wt% TiO 2 nanoparticles (designated as TFN0.60) exhibited the most promising result by showing water Flux of 18.81 L/m 2 h, i.e. 97% higher than the control TFC membrane prepared by substrate without TiO 2 incorporation (designated as TFC), with no significant change in reverse Solute Flux. Compared to the control TFC membrane, the FO water Flux of TFN0.60 was also reported to increase significantly from 4.2 to 8.1 L/m 2 h (AL-FS orientation) and from 6.9 to 13.8 L/m 2 h (AL-DS orientation) when seawater was used as feed solution and 2 M NaCl was used as draw solution. The increase in water Flux can be attributed to the decrease in structural parameter ( S value=0.39 mm), mainly due to the formation of finger-liked macrovoids that connect the top and bottom layer of the substrate and reduce the tortuosity, resulting in decreased ICP. Although further increasing TiO 2 nanoparticles loading to 0.90 wt% could increase membrane water permeability, the FO performance was compromised by a significant increase in reverse Solute Flux. To the best knowledge of the authors, this is the first report on TFN membrane using PSf-TiO 2 nanocomposite substrate for FO applications.