Mixed polyamide-based composite nanofiltration hollow fiber membranes with improved low-pressure water softening capability

Mixed polyamide-based composite nanofiltration (NF) hollow fiber membranes with suitable characteristics for water softening under ultrafiltration (UF)-range low operating pressure were successfully developed. The thin-film selective layer of the composite membrane was formed via interfacial polymer...

Full description

Saved in:
Bibliographic Details
Main Authors: Fang, Wangxi, Shi, Lei, Wang, Rong
Other Authors: School of Civil and Environmental Engineering
Format: Article
Language:English
Published: 2014
Subjects:
Online Access:https://hdl.handle.net/10356/105896
http://hdl.handle.net/10220/20948
Tags: Add Tag
No Tags, Be the first to tag this record!
Institution: Nanyang Technological University
Language: English
id sg-ntu-dr.10356-105896
record_format dspace
spelling sg-ntu-dr.10356-1058962020-09-26T22:03:33Z Mixed polyamide-based composite nanofiltration hollow fiber membranes with improved low-pressure water softening capability Fang, Wangxi Shi, Lei Wang, Rong School of Civil and Environmental Engineering Siemens Global R&D Centre (Water Technologies) Nanyang Environment and Water Research Institute Singapore Membrane Technology Centre DRNTU::Engineering::Environmental engineering::Water treatment Mixed polyamide-based composite nanofiltration (NF) hollow fiber membranes with suitable characteristics for water softening under ultrafiltration (UF)-range low operating pressure were successfully developed. The thin-film selective layer of the composite membrane was formed via interfacial polymerization on the inner surface of a microporous polyethersulfone (PES) hollow fiber substrate with trymesoyl chloride (TMC) being the organic phase monomer, and a mixture of branched polyethyleneimine (PEI) and piperazine (PIP) being the monomers in the aqueous phase. In was found that there was a synergetic effect of PEI and PIP on the formation of the selective layer. The water permeability and salt rejection of the resultant membrane were both enhanced with a small amount of PIP added into the PEI aqueous phase, but dropped quickly with a higher PIP to PEI ratio. The optimized NF membrane possessed a molecular weight cut-off (MWCO) of 380 Da, an effective pore diameter of 1.27 nm, and pure water permeability (PWP) of 18.2 l/m2 h bar. Under an operating pressure of 2 bar, the membrane exhibited rejection of 96.3% and 93.8% to 1000 ppm MgCl2 and MgSO4 feed solutions, respectively. The capability of the newly developed membrane for low-pressure water softening was evaluated by employing simulated hard water feed solutions with different ionic compositions and total hardness. By the combining effect of electrostatic repulsion and size exclusion, the mixed PEI/PIP-based composite hollow fiber offered superior water softening performance compared with the membranes made with PEI or PIP alone as the aqueous phase IP monomer. NRF (Natl Research Foundation, S’pore) EDB (Economic Devt. Board, S’pore) Accepted version 2014-09-22T08:10:59Z 2019-12-06T22:00:18Z 2014-09-22T08:10:59Z 2019-12-06T22:00:18Z 2014 2014 Journal Article ang, W., Shi, L., & Wang, R. (2014). Mixed polyamide-based composite nanofiltration hollow fiber membranes with improved low-pressure water softening capability. Journal of membrane science, 468, 52-61. 0376-7388 https://hdl.handle.net/10356/105896 http://hdl.handle.net/10220/20948 10.1016/j.memsci.2014.05.047 en Journal of membrane science © 2014 Elsevier B. V. This is the author created version of a work that has been peer reviewed and accepted for publication by Journal of Membrane Science. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1016/j.memsci.2014.05.047]. 25 p. + 15 p. figures application/pdf application/pdf
institution Nanyang Technological University
building NTU Library
country Singapore
collection DR-NTU
language English
topic DRNTU::Engineering::Environmental engineering::Water treatment
spellingShingle DRNTU::Engineering::Environmental engineering::Water treatment
Fang, Wangxi
Shi, Lei
Wang, Rong
Mixed polyamide-based composite nanofiltration hollow fiber membranes with improved low-pressure water softening capability
description Mixed polyamide-based composite nanofiltration (NF) hollow fiber membranes with suitable characteristics for water softening under ultrafiltration (UF)-range low operating pressure were successfully developed. The thin-film selective layer of the composite membrane was formed via interfacial polymerization on the inner surface of a microporous polyethersulfone (PES) hollow fiber substrate with trymesoyl chloride (TMC) being the organic phase monomer, and a mixture of branched polyethyleneimine (PEI) and piperazine (PIP) being the monomers in the aqueous phase. In was found that there was a synergetic effect of PEI and PIP on the formation of the selective layer. The water permeability and salt rejection of the resultant membrane were both enhanced with a small amount of PIP added into the PEI aqueous phase, but dropped quickly with a higher PIP to PEI ratio. The optimized NF membrane possessed a molecular weight cut-off (MWCO) of 380 Da, an effective pore diameter of 1.27 nm, and pure water permeability (PWP) of 18.2 l/m2 h bar. Under an operating pressure of 2 bar, the membrane exhibited rejection of 96.3% and 93.8% to 1000 ppm MgCl2 and MgSO4 feed solutions, respectively. The capability of the newly developed membrane for low-pressure water softening was evaluated by employing simulated hard water feed solutions with different ionic compositions and total hardness. By the combining effect of electrostatic repulsion and size exclusion, the mixed PEI/PIP-based composite hollow fiber offered superior water softening performance compared with the membranes made with PEI or PIP alone as the aqueous phase IP monomer.
author2 School of Civil and Environmental Engineering
author_facet School of Civil and Environmental Engineering
Fang, Wangxi
Shi, Lei
Wang, Rong
format Article
author Fang, Wangxi
Shi, Lei
Wang, Rong
author_sort Fang, Wangxi
title Mixed polyamide-based composite nanofiltration hollow fiber membranes with improved low-pressure water softening capability
title_short Mixed polyamide-based composite nanofiltration hollow fiber membranes with improved low-pressure water softening capability
title_full Mixed polyamide-based composite nanofiltration hollow fiber membranes with improved low-pressure water softening capability
title_fullStr Mixed polyamide-based composite nanofiltration hollow fiber membranes with improved low-pressure water softening capability
title_full_unstemmed Mixed polyamide-based composite nanofiltration hollow fiber membranes with improved low-pressure water softening capability
title_sort mixed polyamide-based composite nanofiltration hollow fiber membranes with improved low-pressure water softening capability
publishDate 2014
url https://hdl.handle.net/10356/105896
http://hdl.handle.net/10220/20948
_version_ 1681059618394996736