Organic-Inorganic Co-Modified PVDF Membrane for High-Flux Oil/Water Separation and Simultaneous Multi-Pollutant...

Area of Science:

• Materials Science and Engineering
• Environmental Science and Engineering
• Chemical Engineering

Background:

• Industrial oily wastewater presents a complex challenge due to the simultaneous presence of emulsified oil, dissolved organics, and heavy metal ions.
• Existing one-step treatment methods are often insufficient to address this multi-component contamination effectively.
• Polyvinylidene fluoride (PVDF) membranes are widely used but suffer from fouling and limited removal of dissolved pollutants.

Purpose of the Study:

• To develop a novel organic-inorganic co-modified PVDF composite membrane for efficient one-step treatment of complex industrial oily wastewater.
• To investigate the synergistic effects of tea polyphenols, SiO2, and fibrous MXene on membrane performance, including oil/water separation, antifouling, and pollutant removal.
• To evaluate the membrane's stability, recyclability, and performance in treating simulated wastewater containing multiple contaminants.

Main Methods:

• Fabrication of a modified PVDF composite membrane (MTSP) using nonsolvent-induced phase separation, incorporating tea polyphenols, SiO2, and fibrous MXene.
• Characterization of membrane surface properties, including superhydrophilicity and underwater oleophobicity, using contact angle measurements.
• Evaluation of oil/water separation efficiency, flux, antifouling properties, and removal of dissolved organics and heavy metals under various conditions.

Main Results:

• The MTSP membrane achieved a superhydrophilic/underwater oleophobic surface (water contact angle of 1°, underwater oil contact angle of ~136°), significantly reducing oil fouling.
• High oil/water separation efficiency (~99.5%) and flux (2420-2670 L·m⁻²·h⁻¹) were achieved for various emulsified oils.
• For complex wastewater, the membrane maintained ~99% oil/water separation efficiency while simultaneously removing ~79% of phenol and 70-86% of heavy metal ions (Fe³⁺, Cu²⁺, Zn²⁺, Cd²⁺) in a single step.

Conclusions:

• The synergistic incorporation of tea polyphenols, SiO2, and MXene into PVDF membranes creates a highly effective material for treating complex oily wastewater.
• The developed MTSP membrane demonstrates superior antifouling properties, high flux, and simultaneous removal of emulsified oil, dissolved organics, and heavy metals.
• This work presents a scalable and promising strategy for designing advanced membranes for integrated water treatment applications.