Gravity-driven removal of tetracycline from water using a hierarchically porous adsorptive nanofibrous membrane system functionalized with metal-organic framework.

Antibiotics such as tetracycline (TC) persist in aquatic environments, posing serious risks to ecosystems and public health. Additionally, the excessive and incorrect use of TC has contributed to the development of antimicrobial resistance. Adsorption-based technologies are potential solutions for removing pollutants such as TC from water owing to their operational simplicity, energy efficiency, and compatibility with actual water systems. We fabricated a porous adsorptive nanofibrous membrane via growing ZIF-67 crystals in situ on amidoxime-functionalized polymer of intrinsic microporosity (AO-PIM-1) for removing TC from aquatic environments. The membrane has a hierarchically porous structure with many active sites for effectively capturing TC. The performance of the developed membrane was thoroughly evaluated in a real aquatic environment under static and gravity-driven dynamic conditions. The gravity-driven membrane (GDM) filtration with ethanol regeneration system required no additional energy input, offering an environmentally friendly and sustainable solution for TC removal. The developed membrane showed high TC removal efficiency (>99 %), strong anti-interference performance across various real water conditions, and exhibited minimal performance loss after eight GDM cycles and a total processing volume of 4000 L m-2. Its advanced material design incorporates practical water purification technologies to reduce the antibiotic contamination in engineered water systems.