Abstract
The manner in which membrane-fouling experiments are conducted and how fouling performance data are represented have a strong impact on both how the data are interpreted and on the conclusions that may be drawn. We provide a couple of examples to prove that it is possible to obtain misleading conclusions from commonly used representations of fouling data. Although the illustrative example revolves around dead-end ultrafiltration, the underlying principles are applicable to a wider range of membrane processes. When choosing the experimental conditions and how to represent fouling data, there are three main factors that should be considered: (I) the foulant mass is principally related to the filtered volume; (II) the filtration flux can exacerbate fouling effects (e.g., concentration polarization and cake compression); and (III) the practice of normalization, as in dividing by an initial value, disregards the difference in driving force and divides the fouling effect by different numbers. Thus, a bias may occur that favors the experimental condition with the lower filtration flux and the less-permeable membrane. It is recommended to: (I) avoid relative fouling performance indicators, such as relative flux decline (J/J0); (II) use resistance vs. specific volume; and (III) use flux-controlled experiments for fouling performance evaluation.
Original language | English (US) |
---|---|
Pages (from-to) | 460 |
Journal | Membranes |
Volume | 11 |
Issue number | 7 |
DOIs | |
State | Published - Jun 22 2021 |
Bibliographical note
KAUST Repository Item: Exported on 2021-06-25Acknowledgements: The authors wish to thank Fauzi Ismail, Tony Fane, and Gary Amy for their valuable contributions to the discussions leading to this paper.
ASJC Scopus subject areas
- General Materials Science