In this work, ceramic ultrafiltration membranes deposited with different metal oxides (i.e., TiO2, Fe2O3, MnO2, CuO, and CeO2) of around 10 nm in thickness and similar roughness were tested for O/W emulsion treatment. Distinct membrane fouling tendency was observed, which closely correlated to the properties of the filtration-layer metal oxides (i.e. surface hydroxyl groups, hydrophilicity, surface charge, and adhesion energy for oil droplets). In consistent with the distinct bond strength of the surface hydroxyl groups, hydrophilicity of these common metal oxides are quite different. The differences in hydrophilicity consequently lead to different adhesion of these metal oxides towards oil droplets which consists very well with irreversible membrane fouling tendency. In addition, the surface charge of the metal oxide opposite to that of emulsion can help to alleviate irreversible membrane fouling in ultrafiltration. Highly hydrophilic Fe2O3 with lowest fouling tendency could be a potential filtration-layer material for the fabrication/modification of ceramic membranes for O/W emulsion treatment. To the best of our knowledge, this is the first study clearly showing the correlations between surface properties of filtration-layer metal oxides and ceramic membrane fouling tendency by O/W emulsion.
|Original language||English (US)|
|Number of pages||7|
|Journal||Environmental Science & Technology|
|State||Published - Apr 13 2016|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work was supported by and conducted at King Abdullah University of Science
and Technology (KAUST). Part of the research is also support by Natural Science
Foundation of China (No.51378141). The authors want to thank Saudi Aramco for
providing the crude oil for the experiment, Dr. Yingbang Yao of Thin Film Lab of
KAUST for his help in PLD deposition, Ms. Nini Wei of Advanced Nanofabrication
Imaging and Characterization Lab of KAUST for her help in FIB and STEM, and Dr.
Cyril Aubry of WDRC of KAUST for AFM test.