Synthesis and physical characterization of nickel oxide nanoparticles and its application study in the removal of ciprofloxacin from contaminated water by adsorption: Equilibrium and kinetic studies

Abstract

Considering the risk and importance of antibiotics, especially ciprofloxacin, the allowable discharge level should be reached before disposal to the environment. The aim of this work is to study the application of nickel oxide nanoparticles (NiO NPs) as an efficient adsorbent to remove ciprofloxacin (CIP) from its aqueous solution. Batch experiments were carried out in order to determine the effect of different parameters such as pH of the solution (3–8), contact time (20–120 min), initial CIP concentration (50–200 mg/L) and dosage of NiO NPs (0.04–0.14 g/L) on ciprofloxacin adsorption using NiO NPs. The morphological properties of the NiO NPs were described through the Atomic Force Microscope (AFM), Vibrating Sample Magnetometer (VSM), Dynamic Light Scattering (DLS), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) techniques. Removal efficiency of 99.8% was obtained at pH of 3, nanoparticle dosage of 0.08 g/L, contact time of 100 min, and initial CIP concentration of 200 mg/L at temperature of 25 ± 2°C. The adsorption experimental data were found to fit best into the pseudo-second-order kinetic model (R 2 = 0.999) than the pseudo-first-order model (R 2 = 0.214) which suggests a chemical adsorption process. The Freundlich adsorption isotherm model best described the removal of ciprofloxacin on NiO NPs (R 2 = 0.988). Maximum adsorption capacity, q m of 99.81 mg/g was obtained. The adsorption of ciprofloxacin on NiO NPs was found to be favorable since the intensity of adsorption lies within 1 and 10. Based on the results obtained, it could be concluded that the NiO NPs can efficiently remove ciprofloxacin from its aqueous solutions.