Microwave-assisted synthesis of L-aspartic acid-based metal organic aerogel (MOA) for efficient removal of oxytetracycline from aqueous solution

Developing advanced adsorption materials is of great significance for removing antibiotics from wastewater owing to the increasingly severe issue of antibiotic contamination. Herein, a novel bio-based metal organic aerogel (FLAM) adsorbent with macroscopic shapeability, formed through the coordination of L-aspartic acid (LAA) and Fe salt, was fabricated for the first time via the microwave-assisted synthesis method. Subsequently, the FLAM was used to remove oxytetracycline (OTC) from aqueous solution, and the result indicated FLAM exhibited ultrahigh adsorption capacity for OTC with a record-high value of 1566 mg center dot g(-1), which greatly outperformed the reported adsorbents. The adsorption equilibrium curve and adsorption thermodynamics followed the pseudosecond-order kinetics model and the Freundlich model respectively, which indicated multilayer adsorption and chemisorption dominated the adsorption process. Significantly, the adsorbent also enabled efficient decontamination of tetracycline (TC) and chlortetracycline hydrochloride (CTC). Such an excellent adsorption capability of FLAM can be attributed to multiple factors, i.e., electrostatic interaction, surface complexation and hydrogen bonding. Coexisting experiments demonstrated that the FLAM possessed excellent application ability in treating practical antibiotic wastewater. Ultrahigh adsorption capacity and fast-synthesis method prefigured its broad prospect for OTC-related wastewater remediation.