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Impact of operation conditions, foulant adsorption, and chemical cleaning on the nanomechanical properties of ultrafiltration hollow fiber membranes

Gutierrez, Leonardo; Keucken, Alexander LU ; Aubry, Cyril; Zaouri, Noor; Teychene, Benoit and Croue, Jean Philippe (2018) In Colloids and Surfaces A: Physicochemical and Engineering Aspects 549. p.34-42
Abstract

This study analyzed the change in nanomechanical properties of ultrafiltration hollow fiber membranes harvested from pilot-scale units after twelve months of operation. Quantitative Nanomechanical Mapping technique was used to distinguish between adhesion, dissipation, deformation, and modulus while simultaneously generating a topographic image of membranes. Nanomechanical maps of virgin membranes evidenced surfaces of heterogeneous properties and were described by probability density functions. Operating conditions and feed quality exerted an impact on membranes. Clean harvested membranes showed a higher mean modulus and dissipation, and a lower deformation than virgin membranes, indicating stiffer membranes of lower elastic... (More)

This study analyzed the change in nanomechanical properties of ultrafiltration hollow fiber membranes harvested from pilot-scale units after twelve months of operation. Quantitative Nanomechanical Mapping technique was used to distinguish between adhesion, dissipation, deformation, and modulus while simultaneously generating a topographic image of membranes. Nanomechanical maps of virgin membranes evidenced surfaces of heterogeneous properties and were described by probability density functions. Operating conditions and feed quality exerted an impact on membranes. Clean harvested membranes showed a higher mean modulus and dissipation, and a lower deformation than virgin membranes, indicating stiffer membranes of lower elastic deformation. A significant fraction of these measurements displayed peak values deviating from the distribution; which represents regions of the membrane with properties highly differing from the probability density function. The membrane polymeric material experienced severe physicochemical changes by foulant adsorption and reaction with cleaning agents. Foulant adsorption on membranes was heterogeneous in both morphology and mechanical properties and could not be statistically described. Foulants, i.e., mainly consisting of polysaccharides and proteinaceous structures, displayed low elastic deformation and high roughness and adhesion. The presence of foulants after chemical cleaning and their high adhesion would be a direct nanoscale evidence of irreversible fouling. By the end of the operation, the Trans-Membrane Pressure experienced a 40% increase. The cleaning process was not able to fully recover the initial TMP, indicating irreversible fouling, i.e., permanent change in membrane characteristics and decrease in performance. These results suggest a link between the macroscopic properties and nanomechanical characteristics of membranes. This study advances our nanoscale understanding of the impact of fouling and operating conditions on membranes characteristics.

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type
Contribution to journal
publication status
published
subject
keywords
Atomic force microscopy, Fouling, Nanomechanical properties, QNM, Ultrafiltration hollow fiber membrane
in
Colloids and Surfaces A: Physicochemical and Engineering Aspects
volume
549
pages
9 pages
publisher
Elsevier
external identifiers
  • scopus:85045037574
ISSN
0927-7757
DOI
10.1016/j.colsurfa.2018.04.003
language
English
LU publication?
yes
id
c9da1b11-0221-4929-bf40-ef237daaa51f
date added to LUP
2018-04-16 15:51:46
date last changed
2018-05-29 10:37:26
@article{c9da1b11-0221-4929-bf40-ef237daaa51f,
  abstract     = {<p>This study analyzed the change in nanomechanical properties of ultrafiltration hollow fiber membranes harvested from pilot-scale units after twelve months of operation. Quantitative Nanomechanical Mapping technique was used to distinguish between adhesion, dissipation, deformation, and modulus while simultaneously generating a topographic image of membranes. Nanomechanical maps of virgin membranes evidenced surfaces of heterogeneous properties and were described by probability density functions. Operating conditions and feed quality exerted an impact on membranes. Clean harvested membranes showed a higher mean modulus and dissipation, and a lower deformation than virgin membranes, indicating stiffer membranes of lower elastic deformation. A significant fraction of these measurements displayed peak values deviating from the distribution; which represents regions of the membrane with properties highly differing from the probability density function. The membrane polymeric material experienced severe physicochemical changes by foulant adsorption and reaction with cleaning agents. Foulant adsorption on membranes was heterogeneous in both morphology and mechanical properties and could not be statistically described. Foulants, i.e., mainly consisting of polysaccharides and proteinaceous structures, displayed low elastic deformation and high roughness and adhesion. The presence of foulants after chemical cleaning and their high adhesion would be a direct nanoscale evidence of irreversible fouling. By the end of the operation, the Trans-Membrane Pressure experienced a 40% increase. The cleaning process was not able to fully recover the initial TMP, indicating irreversible fouling, i.e., permanent change in membrane characteristics and decrease in performance. These results suggest a link between the macroscopic properties and nanomechanical characteristics of membranes. This study advances our nanoscale understanding of the impact of fouling and operating conditions on membranes characteristics.</p>},
  author       = {Gutierrez, Leonardo and Keucken, Alexander and Aubry, Cyril and Zaouri, Noor and Teychene, Benoit and Croue, Jean Philippe},
  issn         = {0927-7757},
  keyword      = {Atomic force microscopy,Fouling,Nanomechanical properties,QNM,Ultrafiltration hollow fiber membrane},
  language     = {eng},
  month        = {07},
  pages        = {34--42},
  publisher    = {Elsevier},
  series       = {Colloids and Surfaces A: Physicochemical and Engineering Aspects},
  title        = {Impact of operation conditions, foulant adsorption, and chemical cleaning on the nanomechanical properties of ultrafiltration hollow fiber membranes},
  url          = {http://dx.doi.org/10.1016/j.colsurfa.2018.04.003},
  volume       = {549},
  year         = {2018},
}