Amino-Functionalized Zirconium-Based Metal-Organic Framework Membrane on Stainless Steel Mesh for Oil-in-Water...

Area of Science:

• Materials Science
• Environmental Engineering
• Chemical Engineering

Background:

• Stable oil-in-water emulsions in oilfield wastewater present significant treatment challenges.
• Efficient separation is crucial for environmental protection and water resource management.

Purpose of the Study:

• To develop a robust membrane for efficient separation of stable oil-in-water emulsions.
• To investigate the performance and mechanism of the fabricated membrane under various conditions.

Main Methods:

• Fabrication of an amino-functionalized zirconium-based metal-organic framework-coated stainless steel mesh membrane (ZMN-S) via dopamine-assisted surface modification, in situ growth, and ligand exchange.
• Comprehensive characterization using XRD, FTIR, SEM, EDS, XPS, laser confocal microscopy, and thermogravimetric analysis.
• Separation experiments evaluating performance with various emulsions and under high-salinity and high-temperature conditions.

Main Results:

• The ZMN-S membrane exhibited uniform Zr-MOF crystal anchoring and a hydrophilic micro/nanostructured interface.
• Achieved high separation efficiencies: 99.51% for dichloromethane-in-water and 97.81% for crude oil-in-water emulsions.
• Demonstrated excellent environmental adaptability, maintaining high separation efficiencies (96.51-97.92%) under harsh conditions.
• Breakthrough pressure was determined to be 14.09 kPa, attributed to pore structure and superoleophobic interface.

Conclusions:

• The ZMN-S membrane offers a robust and effective solution for separating stable oil-in-water emulsions.
• The synergistic effects of the hydrated surface, demulsification, and sieving mechanism enhance separation performance.
• This work presents a viable strategy for designing advanced MOF-based membranes for wastewater treatment.