Electrospinning-hydrothermal synergistic synthesis of Zr/Al-MOF@PAN/PEI nanofiber membrane: toward efficient emulsion separation and simultaneous heavy metal removal

Treating oily wastewater containing heavy metal ions is a major challenge for traditional membranes, mainly due to limited fouling resistance and versatility. Based on this, this paper develops a hydrophilic zirconium/aluminum bimetallic organic framework functionalized superhydrophilic nanocomposite fiber membrane (Zr/Al-MOF@PAN/PEI) for simultaneous separation of oil-water emulsion and heavy metal removal. This membrane has excellent hydrophilicity and underwater oleophobicity, with a WCA of 3.5° and UOCA of 150°. Surprisingly, this composite membrane also demonstrated excellent separation performance for various oil-in-water emulsions, with a penetration flux of up to 4990 L·m −2 ·h −1 , separation efficiency exceeding 99.99%, and stable separation performance maintained even after 20 separation cycle tests. Moreover, this composite membrane achieves outstanding heavy metal adsorption capacity, especially for Pb (II) adsorption at 210.86 mg g −1 , with a removal efficiency exceeding 99. 8%. Moreover, this composite membrane exhibits stable structural characteristics and excellent anti-fouling performance in a wide pH (3−11) range and high salinity environment, while also featuring high osmotic flux, excellent heavy metal adsorption capacity, and good recycling and regeneration performance, effectively solving the challenges of managing complex oily composite polluted wastewater. This work provides a simple method for manufacturing multifunctional membranes, offering a novel technical approach for efficient remediation of complex heavy metal-rich oily wastewater.