Restructuring of natural-based polyester nanofiltration membranes with alendronate sodium for enhanced filtration performance

Nanofiltration (NF) membranes with high water flux and improved rejection of antibiotics and dyes are desired for mitigating the impact of water pollution on human health. Herein, a facile surface modification strategy was employed to restructure the selective layer of the interfacial polymerization (IP) between naringenin (Nar) and trimesoyl chloride (TMC) (the membrane fabricated by IP was recorded as the NTM membrane) by alendronate sodium (AS). Through AS amines react with residual acyl chlorides on the freshly formed Nar-TMC layer to form amide linkages, realizing the construction of high-performance NF membrane. The AS modification enabling the fabricated AS-NTM membrane demonstrated enhanced surface hydrophilicity, roughness, negatively charged density, and well-designed pores. The AS-NTM membrane thus exhibited improved water flux and removal performance of antibiotics and dyes. The AS-NTM membrane presented a removal rate of ≥98.0 % for the dyes (methyl orange, sunset yellow, reactive Orange 16, and reactive Blue19, respectively), and antibiotics (cefoperazone sodium, ceftriaxone sodium, cefuroxime sodium, cephalothin, ceftizoxime, respectively) with a water permeance of 8.6 ± 0.8 L m −2  h −1  bar −1 . The simple surface modification approach using hydrophilic and negatively charged commercial AS enabled the modulation of the physicochemical structure and filtration performance of NF membrane. This work demonstrates a potential method for fabricating high-performance NF membrane using readily available compounds.