Preparation of Zr-MOFs and removal of tetracycline hydrochloride

In this study, Zr-based metal–organic frameworks (Zr-MOFs) were synthesized via a solvothermal method using zirconium acetate and 3,3′,5,5′-tetramethylbenzidine as the metal precursor and organic ligand, respectively. The synthesized MOFs were characterized using Fourier-transform infrared spectroscopy, x-ray diffraction, and scanning electron microscopy. The adsorption efficiency of MOFs for tetracycline hydrochloride removal was investigated. Results revealed that adding 20 mg of MOFs to a 50 ppm tetracycline hydrochloride solution resulted in a maximum adsorption capacity of 240.3 mg/g within 5 h. Kinetic modeling confirmed that the adsorption process followed the pseudo-second-order kinetic model, while isothermal adsorption conformed to the Freundlich model. This indicates that multilayer adsorption was the dominant removal mechanism for tetracycline hydrochloride by MOFs.