Influence of pH and NaCl concentration on boron rejection during nanofiltration
Nanofiltration (NF) is promising for replacing reverse osmosis for boron removal more effectively and at a higher energy efficiency. However, the interplay of steric and charge effects underlying rejection behaviors of solutes smaller than the membrane pore size remained incompletely understood, whi...
Saved in:
Main Authors: | , , , , |
---|---|
Other Authors: | |
Format: | Article |
Language: | English |
Published: |
2022
|
Subjects: | |
Online Access: | https://hdl.handle.net/10356/160441 |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Institution: | Nanyang Technological University |
Language: | English |
id |
sg-ntu-dr.10356-160441 |
---|---|
record_format |
dspace |
spelling |
sg-ntu-dr.10356-1604412022-07-22T05:14:45Z Influence of pH and NaCl concentration on boron rejection during nanofiltration Han, Le Tian, Ju Liu, Chang Lin, Jiuyang Chew, Jia Wei School of Chemical and Biomedical Engineering Nanyang Environment and Water Research Institute Singapore Membrane Technology Centre Engineering::Environmental engineering Nanofiltration Pore Size Nanofiltration (NF) is promising for replacing reverse osmosis for boron removal more effectively and at a higher energy efficiency. However, the interplay of steric and charge effects underlying rejection behaviors of solutes smaller than the membrane pore size remained incompletely understood, which impedes implementation. This study investigated the influence of pH and NaCl concentration on boric acid/borate rejection by the Desal 5DK NF membrane, with acetic acid/acetate (comparable size and charge nature) and glucose (larger and neutral) serving as benchmarks. Filtration experiments demonstrate that varying pH in the range of 3–11 and NaCl concentration up to 100 mM had little effect on glucose rejection (consistently greater than 95%), but affected the two smaller solutes significantly. Increasing pH from 7 to 11 led to 15% higher rejection of charged acetate because of the increased charges of both the membrane and solute, while increasing pH from 3 to 7 gave 30% higher rejection of neutral boric acid due to steric effects stemming from pore-size reduction. The rejections of the neutral boric acid and acetic acid were negligibly affected by NaCl concentration, but rejection decreased by 15% and 50% for the charged borate and acetate, respectively, due to salt-induced pore-swelling. Agency for Science, Technology and Research (A*STAR) Economic Development Board (EDB) Ministry of Education (MOE) This work was supported by the Singapore GSK (GlaxoSmithKline) EDB (Economic Development Board) Trust Fund, A*STAR (Singapore) Advanced Manufacturing and Engineering (AME) under its Pharma Innovation Programme Singapore (PIPS) program (A20B3a0070) and Individual Research Grant (IME) program (A2083c0049), and Singapore Ministry of Education Tier 1 Grant (2019-T1-002-065) and National Natural Science Foundation of China (51908083). 2022-07-22T05:14:45Z 2022-07-22T05:14:45Z 2021 Journal Article Han, L., Tian, J., Liu, C., Lin, J. & Chew, J. W. (2021). Influence of pH and NaCl concentration on boron rejection during nanofiltration. Separation and Purification Technology, 261, 118248-. https://dx.doi.org/10.1016/j.seppur.2020.118248 1383-5866 https://hdl.handle.net/10356/160441 10.1016/j.seppur.2020.118248 2-s2.0-85099180555 261 118248 en A20B3a0070 A2083c0049 2019-T1-002-065 Separation and Purification Technology © 2021 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::Environmental engineering Nanofiltration Pore Size |
spellingShingle |
Engineering::Environmental engineering Nanofiltration Pore Size Han, Le Tian, Ju Liu, Chang Lin, Jiuyang Chew, Jia Wei Influence of pH and NaCl concentration on boron rejection during nanofiltration |
description |
Nanofiltration (NF) is promising for replacing reverse osmosis for boron removal more effectively and at a higher energy efficiency. However, the interplay of steric and charge effects underlying rejection behaviors of solutes smaller than the membrane pore size remained incompletely understood, which impedes implementation. This study investigated the influence of pH and NaCl concentration on boric acid/borate rejection by the Desal 5DK NF membrane, with acetic acid/acetate (comparable size and charge nature) and glucose (larger and neutral) serving as benchmarks. Filtration experiments demonstrate that varying pH in the range of 3–11 and NaCl concentration up to 100 mM had little effect on glucose rejection (consistently greater than 95%), but affected the two smaller solutes significantly. Increasing pH from 7 to 11 led to 15% higher rejection of charged acetate because of the increased charges of both the membrane and solute, while increasing pH from 3 to 7 gave 30% higher rejection of neutral boric acid due to steric effects stemming from pore-size reduction. The rejections of the neutral boric acid and acetic acid were negligibly affected by NaCl concentration, but rejection decreased by 15% and 50% for the charged borate and acetate, respectively, due to salt-induced pore-swelling. |
author2 |
School of Chemical and Biomedical Engineering |
author_facet |
School of Chemical and Biomedical Engineering Han, Le Tian, Ju Liu, Chang Lin, Jiuyang Chew, Jia Wei |
format |
Article |
author |
Han, Le Tian, Ju Liu, Chang Lin, Jiuyang Chew, Jia Wei |
author_sort |
Han, Le |
title |
Influence of pH and NaCl concentration on boron rejection during nanofiltration |
title_short |
Influence of pH and NaCl concentration on boron rejection during nanofiltration |
title_full |
Influence of pH and NaCl concentration on boron rejection during nanofiltration |
title_fullStr |
Influence of pH and NaCl concentration on boron rejection during nanofiltration |
title_full_unstemmed |
Influence of pH and NaCl concentration on boron rejection during nanofiltration |
title_sort |
influence of ph and nacl concentration on boron rejection during nanofiltration |
publishDate |
2022 |
url |
https://hdl.handle.net/10356/160441 |
_version_ |
1739837443232759808 |