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Updated: Aug 17, 2025
09:43
Interfacial Molecular-level Structures of Polymers and Biomacromolecules Revealed via Sum Frequency Generation Vibrational Spectroscopy
Published on: August 13, 2019
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Probing Silica-Kaolinite Interactions with Sum Frequency Generation Spectroscopy.
Mokhtar Rashwan1, Benjamin Rehl1, Nikolas Romaniuk2
1Department of Chemistry, University of Alberta, Edmonton, AlbertaT6G 2G2, Canada.
Langmuir : the ACS Journal of Surfaces and Colloids
|December 15, 2022
Summary
Lime treatment effectively dewaters oil sands tailings by altering the silica-kaolinite interface, promoting water release and material consolidation for land reclamation. This chemical approach shows promise for environmental remediation.
Area of Science:
- Environmental Science
- Geochemistry
- Materials Science
Background:
- Oil sands tailings ponds pose significant environmental challenges due to large volumes and the need for effective treatment.
- Current treatment methods struggle with efficient water release and consolidation for land reclamation.
Purpose of the Study:
- To investigate the impact of lime and sodium hydroxide (NaOH) on the silica/aqueous kaolinite interface.
- To understand the mechanisms of tailings dewatering and consolidation at the mineral-water interface.
Main Methods:
- Utilized vibrational sum frequency generation (SFG) spectroscopy to study the silica/aqueous kaolinite interface.
- Measured ζ-potential of silica and kaolinite under varying pH conditions with lime and NaOH addition.
Main Results:
- Lime addition at pH 12.0 and above caused the disappearance of interfacial water features and increased kaolinite adsorption on silica, indicating dewatering.
- NaOH addition resulted in persistent interfacial water signals even at high pH, despite increased kaolinite adsorption.
- ζ-potential measurements provided further insights into the surface chemistry under different alkaline conditions.
Conclusions:
- Lime treatment facilitates dewatering of oil sands tailings by modifying the mineral-water interface, unlike NaOH treatment.
- The findings suggest lime is a more effective chemical agent for tailings consolidation and reclamation.
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