Magnetic Metal–Organic Framework: An Innovative Nanocomposite Adsorbent for the Removal of Emerging Drug Contaminants from Water

The widespread use of antibiotics has taken a heavy toll on the environment, which cannot be ignored. Tetracycline antibiotics (TCs), as representative pharmaceutical contaminants, have emerged as a growing environmental concern due to their persistence and potential ecological risks. This study utilized 1,3,5-benzenetricarboxylic acid (BTC) as a functionalizing reagent to synthesize magnetic nanoparticles NiFe2O4-COOH. These were then combined with Zr-MOF to create the magnetic adsorbent designated as NCF@Zr-MOF (where NCF represents carboxyl-functionalized nickel ferrite). Magnetic solid-phase extraction (MSPE) technology was employed to remove two representative tetracycline antibiotics, tetracycline (TC) and chlortetracycline (CTC) from the environment. The Langmuir model fitting revealed maximum adsorption reached 190.85 and 196.32 mg/g for TC and CTC, respectively, both of which conformed to the pseudo-second-order model during the adsorption process with spontaneous, heat-absorbing and entropy-increasing properties. Furthermore, following five cycles of adsorption and desorption, the removal rate for TCs was found to have decreased by 30%, yet the removal of CTCs remained at 95.32%. This adsorbent enables rapid separation via an external magnetic field. With its excellent stability and reusability, NCF@Zr-MOF shows great potential for removing antibiotics from water.