PVDF/MIL-101(Cr)/chitin mixed matrix membrane as a high-performance adsorbent for the rapid and efficient removal of ibuprofen from aqueous solution

Ibuprofen (IBP), one of the most commonly used nonsteroidal anti-inflammatory drugs, has been detected in aquatic environments. In this study, a Cr-MOF-based mixed-matrix membrane (MMM) was successfully synthesized via the phase inversion technique for the adsorptive removal of IBP. The MMM was prepared using a combination of porous fillers, including MIL-101(Cr), chitin as a biopolymer, and polyvinylidene fluoride as the polymer matrix, and was designated as PCN- x ( x = 1, 3, 5, and 7 wt%). Herein, the term PCN denotes PVDF (P), MIL-101(Cr) (C), and chitin (N). The adsorption performance was evaluated through batch experiments, where the optimized MMM containing 5 wt% MIL-101(Cr) (PCN-5) with a dosage of 2 g/L exhibited a maximum adsorption capacity of 22.7 mg/g and a removal efficiency of 99.9 % for IBP. Adsorption kinetics followed the pseudo-second-order model, while the equilibrium data were well described by the Langmuir isotherm. The adsorption mechanism was mainly governed by hydrogen bonding, π–π interactions, and pore-filling within the porous structure of the PCN-5, as evidenced by FT-IR and XPS analyses after IBP adsorption. PCN-5 maintained high adsorption performance (>85 %) for the seven consecutive adsorption–desorption cycles and exhibited minimal Cr leaching (<0.15 mg/L), thereby confirming its structural stability and ensuring its environmental safety. These findings suggest that PCN-5 represents a promising membrane material fabricated from biodegradable polymers, with potential applications in the removal of emerging organic contaminants from aquatic systems.