High-performance electrospinning-phase inversion composite PDMS membrane for extractive membrane bioreactor: Fabrication, characterization, optimization and application

This study introduced a facile approach for high-performance electrospinning-phase inversion composite membrane, aiming at solving the low mechanical property, low mass transfer and salt leakage in extractive membrane bioreactor (EMBR) for phenol saline wastewater treatment. Composite membrane was fabricated through coating polydimethylsiloxane (PDMS) on electrospun PDMS membrane via dry phase inversion. Its surface was similar to that of phase inversion membrane while the cross section was uniformly distributed electrospun fibers in phase inversion layer, forming interconnected pore. The loose porous structure and high porosity were suitable for phenol permeation, and hydrophobic surface could reject the salt invasion. The tensile strength and elongation at break of composite membrane (56.5 μm thickness) were 1.7 MPa and 60.0%, making it stably operated in EMBR. Effects of different process variables were investigated, including membrane thickness, phenol concentration and wastewater flow rate. Remarkable performance of phenol biodegradation and salt rejection was achieved during EMBR operation, where the maximal phenol removal rate and conductivity variation in microorganism side were 508.9 mg L−1 d−1 and <0.1 ms cm−1, respectively. The highest phenol mass transfer coefficient of 8.8 × 10−7 m s−1 was achieved. It is reasonable to believe that this study fabricate a promising alternative membrane for EMBR application.