Sustainable Synthesis of Trimetallic Al/Mg/Fe-BDC MOF Nanorods from Recycled PET Waste for Ultrafast Ciprofloxacin...

Despite continuous efforts to mitigate antibiotic resistance, the persistent accumulation of ciprofloxacin (CIP) in aquatic systems remains a growing environmental concern, underscoring the need for effective and sustainable removal strategies. In this study, a novel trimetallic metal-organic framework nanomaterial (Al/Mg/Fe-BDC MOF) was successfully synthesized via a one-step solvothermal approach, utilizing a terephthalic acid linker sustainably derived from postconsumer PET waste. The synthesized material was characterized by XRD, FT-IR, SEM, BET, and TGA analyses. The Al/Mg/Fe-BDC MOF exhibited a rapid adsorption response, achieving 90% removal of CIP within only 5 min under nonoptimized conditions. Under optimized conditions (10 mg L^-1 CIP concentration, 25 mg adsorbent dose, pH 5, contact time 20 min), the removal efficiency reached 97.6%, with a maximum adsorption capacity of 224.8 mg g^-1. The adsorption kinetics followed the pseudo-second-order model, and the equilibrium data were best fitted to the Langmuir isotherm, indicating monolayer adsorption driven by complex physicochemical interactions. The superior performance was attributed to a multifaceted synergistic effect, characterized by a significant expansion of the specific surface area (1122 m² g^-1) and refined pore architecture, coupled with an optimized surface charge (pH_pzc = 4.6) that enhances electrostatic attraction. Furthermore, the Al/Mg/Fe-BDC MOF demonstrated outstanding hydrolytic stability and reusability, retaining 90.8% efficiency over five consecutive cycles with negligible metal leaching and retained crystallinity, highlighting its strong potential for the sustainable treatment of pharmaceutical wastewater.