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Preparation and characterization of thin-film composite membrane with nanowire-modified support for forward osmosis process.

Low ZX, Liu Q, Shamsaei E, Zhang X, Wang H - Membranes (Basel) (2015)

Bottom Line: In FO mode, the ratio of water flux to reverse solute flux was also improved.The result shows that Zn2GO4 nanowire may be used as a modifier to the substrate to improve the quality of the polyamide layer on the substrate to improve the flux and selectivity, but not as effective in reducing ICP.This work demonstrates that the incorporation of nanomaterials to the membrane substrate may be an alternative approach to improve the formation of polyamide skin layer to achieve better FO performance.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Engineering, Monash University, Clayton VIC 3800, Australia.

ABSTRACT
Internal concentration polarization (ICP) in forward osmosis (FO) process is a characteristic problem for asymmetric thin-film composite (TFC) FO membrane which leads to lower water flux. To mitigate the ICP effect, modification of the substrates' properties has been one of the most effective methods. A new polyethersulfone-based ultrafiltration membrane with increased surface porosity and high water flux was recently produced by incorporating Zn2GeO4 nanowires. The composite membrane was used as a substrate for the fabrication of TFC FO membrane, by coating a thin layer of polyamide on top of the substrate. The substrate and the nanowires were characterized by a range of techniques such as SEM, XRD, and contact angle goniometry. The water permeability and molecular weight cut-offs (MWCO) of the substrate; and the FO performance of the TFC membrane were also determined. The Zn2GeO4-modified membrane showed ~45% increase in water permeability and NaCl salt rejection of 80% under RO mode. In FO mode, the ratio of water flux to reverse solute flux was also improved. However, lower FO flux was obtained which could be due to ICP. The result shows that Zn2GO4 nanowire may be used as a modifier to the substrate to improve the quality of the polyamide layer on the substrate to improve the flux and selectivity, but not as effective in reducing ICP. This work demonstrates that the incorporation of nanomaterials to the membrane substrate may be an alternative approach to improve the formation of polyamide skin layer to achieve better FO performance.

No MeSH data available.


Water permeability and NaCl rejection of pristine membrane and Zn2GeO4/PES/PA forward osmosis (FO) membrane in reverse osmosis (RO) mode.
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membranes-05-00136-f003: Water permeability and NaCl rejection of pristine membrane and Zn2GeO4/PES/PA forward osmosis (FO) membrane in reverse osmosis (RO) mode.

Mentions: The effect of Zn2GeO4 on membrane water permeability and salt rejection were evaluated in RO mode. Figure 3 shows the RO performance of both pristine and modified the membrane. The modified membrane shows ~45% increase in pure water permeability and slight increase in the salt rejection. This indicates a higher quality of polyamide formed on top of the membrane which will be discussed with the FO result. The permeability and salt rejection of three commercial membranes along with those reported elsewhere (CTA-HW [11], CTA-W [7], and CTA-NW [7]) and the membranes from current work are shown in Table 1. The three membranes were all based on cellulose triacetate (CTA). From Table 1, TFC membrane performed better than CTA membrane in RO mode due to its thin active layer. However, the results from the commercial membranes should not be directly compared since the RO test was done in different conditions.


Preparation and characterization of thin-film composite membrane with nanowire-modified support for forward osmosis process.

Low ZX, Liu Q, Shamsaei E, Zhang X, Wang H - Membranes (Basel) (2015)

Water permeability and NaCl rejection of pristine membrane and Zn2GeO4/PES/PA forward osmosis (FO) membrane in reverse osmosis (RO) mode.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4384095&req=5

membranes-05-00136-f003: Water permeability and NaCl rejection of pristine membrane and Zn2GeO4/PES/PA forward osmosis (FO) membrane in reverse osmosis (RO) mode.
Mentions: The effect of Zn2GeO4 on membrane water permeability and salt rejection were evaluated in RO mode. Figure 3 shows the RO performance of both pristine and modified the membrane. The modified membrane shows ~45% increase in pure water permeability and slight increase in the salt rejection. This indicates a higher quality of polyamide formed on top of the membrane which will be discussed with the FO result. The permeability and salt rejection of three commercial membranes along with those reported elsewhere (CTA-HW [11], CTA-W [7], and CTA-NW [7]) and the membranes from current work are shown in Table 1. The three membranes were all based on cellulose triacetate (CTA). From Table 1, TFC membrane performed better than CTA membrane in RO mode due to its thin active layer. However, the results from the commercial membranes should not be directly compared since the RO test was done in different conditions.

Bottom Line: In FO mode, the ratio of water flux to reverse solute flux was also improved.The result shows that Zn2GO4 nanowire may be used as a modifier to the substrate to improve the quality of the polyamide layer on the substrate to improve the flux and selectivity, but not as effective in reducing ICP.This work demonstrates that the incorporation of nanomaterials to the membrane substrate may be an alternative approach to improve the formation of polyamide skin layer to achieve better FO performance.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Engineering, Monash University, Clayton VIC 3800, Australia.

ABSTRACT
Internal concentration polarization (ICP) in forward osmosis (FO) process is a characteristic problem for asymmetric thin-film composite (TFC) FO membrane which leads to lower water flux. To mitigate the ICP effect, modification of the substrates' properties has been one of the most effective methods. A new polyethersulfone-based ultrafiltration membrane with increased surface porosity and high water flux was recently produced by incorporating Zn2GeO4 nanowires. The composite membrane was used as a substrate for the fabrication of TFC FO membrane, by coating a thin layer of polyamide on top of the substrate. The substrate and the nanowires were characterized by a range of techniques such as SEM, XRD, and contact angle goniometry. The water permeability and molecular weight cut-offs (MWCO) of the substrate; and the FO performance of the TFC membrane were also determined. The Zn2GeO4-modified membrane showed ~45% increase in water permeability and NaCl salt rejection of 80% under RO mode. In FO mode, the ratio of water flux to reverse solute flux was also improved. However, lower FO flux was obtained which could be due to ICP. The result shows that Zn2GO4 nanowire may be used as a modifier to the substrate to improve the quality of the polyamide layer on the substrate to improve the flux and selectivity, but not as effective in reducing ICP. This work demonstrates that the incorporation of nanomaterials to the membrane substrate may be an alternative approach to improve the formation of polyamide skin layer to achieve better FO performance.

No MeSH data available.