Emerging Contaminants Removal Using ZnO Nanoparticles: Adsorption of Tetracycline and Ciprofloxacin

Abstract Ciprofloxacin (CIP) and tetracycline (TC) antibiotics can leave residues in water, which can have harmful effects on the ecosystem. Consequently, researchers have investigated the performance, reusability, and regeneration of zinc oxide nanoparticles (ZnO NPs) for the adsorption of CIP and TC. The characterization of the materials before and after adsorption was accomplished by N 2  adsorption/desorption isotherm, X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FT‐IR), and field emission scanning electron microscope (FE‐SEM). The effects of the contact time, ZnO dose, initial concentrations of TC and CIP and solution pH on the adsorption capacity of ZnO towards CIP and TC were studied. Moreover, the adsorption equilibrium data were described by non‐linear isothermal modeling. The maximum adsorption capacity (q max ) reached 62.5 mg g −1 for TC at pH ∼ 5, dosage 0.5 g, TC initial concentration 300 mg L −1 , and contact time 30 min. For CIP, q max was 103.5 mg g −1  at pH ∼ 7, dosage 0.1 g, CIP initial concentration of 100 mg L −1 , and contact time 30 min. Additionally, the exhausted adsorbents (CIP@ZnO and TC@ZnO) have been studied for removing various antibiotics, dyes, and nutrients from water. This opens up a new pathway for transforming waste into valuable materials that can be utilized in water treatment.