| 1. |
- Byhlin, Henric, et al.
(författare)
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Influence of adsorption and concentration polarisation on membrane performance during ultrafiltration of a non-ionic surfactant
- 2003
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Ingår i: Desalination. - 1873-4464. ; 151:1, s. 21-31
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Tidskriftsartikel (refereegranskat)abstract
- Surfactants are present in almost all aqueous solutions-either as additives for different purposes, or because they occur naturally. Because of the common occurrence of surfactants in process water it is important to know how they behave in membrane processes. Ultrafiltration membranes allow almost complete passage of surfactant monomers, but reject micelles almost completely. Concentration polarisation during ultrafiltration of surfactant solutions is therefore mainly influenced by the presence of micelles. Operating parameters, e.g. the transmembrane pressure and the concentration of surfactant, as well as the pure water flux of the membrane, have a marked influence on the performance of hydrophilic membranes, as shown in this investigation. A distinct difference between the interaction of a non-ionic surfactant with hydrophilic and hydrophobic membranes was observed. The hydrophobic membrane showed a flux reduction already at concentrations below the critical micelle concentration (CMC), whereas no flux reduction was observed for a hydrophilic membrane with the same nominal molecular weight cut-off, below the CMC.
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| 2. |
- Jönsson, Ann-Sofi, et al.
(författare)
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A concentration polarization model for the ultrafiltration of nonionic surfactants
- 2006
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 1095-7103 .- 0021-9797. ; 304:1, s. 191-199
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Tidskriftsartikel (refereegranskat)abstract
- A theoretical model has been developed that describes ultrafiltration of nonionic surfactants. The model takes into account the fact that surfactants start to aggregate and form micelles at the critical micelle concentration, The model can be used to predict the performance of the membrane if the transport properties inside and at the membrane surface as well as the surfactant association behavior, are known. Three hydrophilic ultrafiltration membranes, made of regenerated cellulose, were used in the investigation. The cut-offs of the membranes were 10,000, 20,000, and 30,000 Da. The surfactant used in the investigation was the nonionic surfactant Triton X-100. The influence of the concentration of surfactant, transmembrane pressure and pure water flux were studied theoretically and experimentally. From the results presented in this work it can be concluded that the calculated values are in good agreement with experimental data. (c) 2006 Elsevier Inc. All rights reserved.
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