The molecular structures of polysaccharides affect their reverse osmosis membrane fouling behaviors
| Autor: | Hong-Ying Hu, Nozomu Ikuno, Xue-Hao Zhao, Kazuki Ishii, Yin-Hu Wu, Xin Tong, Yuan Bai |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
chemistry.chemical_classification
Molecular mass Fouling Chemistry Membrane fouling Filtration and Separation 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Polysaccharide 01 natural sciences Biochemistry 0104 chemical sciences Viscosity Membrane Chemical engineering Molecule General Materials Science Physical and Theoretical Chemistry 0210 nano-technology Reverse osmosis |
| Zdroj: | Journal of Membrane Science. 625:118984 |
| ISSN: | 0376-7388 |
| DOI: | 10.1016/j.memsci.2020.118984 |
| Popis: | Polysaccharides were usually considered as important organic compounds causing organic fouling of reverse osmosis (RO) membranes. In this study, the RO membrane fouling behaviors and mechanisms of 9 polysaccharides with different molecular weights and structures were studied. It was found that not the molecular weight but the molecular structure mainly influenced the fouling behavior. Straight-chain polysaccharides tended to cause slight and slow membrane fouling (final flux decline 50% in 50 h) and formed thicker foulant layers on membrane surfaces. The presence of Ca2+ could double and even triple the flux decline of straight-chain acid polysaccharides, but showed barely effect on branched-chain polysaccharides as well as neutral polysaccharides. The extended Derjaguin-Laudau-Verwey-Overbeek (XDLVO) theory revealed that attractive energy dominated the interaction between branched-chain polysaccharides and membranes. The addition of Ca2+ turned the repulsive interaction between straght-chain acid polysaccharides and membranes into attractive interaction, but showed no significant effect on neutral polysaccharides. The viscosity of straight-chain polysaccharides didn't increase with the polysaccharide concentrations, while that of branched-chain polysaccharides showed a positive relationship with mass concentrations. Ca2+ also enhanced the viscosity of straight-chain acid polysaccharides. |
| Databáze: | OpenAIRE |
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