Effective adsorption of ciprofloxacin antibiotic using powdered activated carbon magnetized by iron(III) oxide magnetic nanoparticles

Abstract

In the present work, the adsorption performance of powdered activated carbon magnetized by iron(III) oxide magnetic nanoparticles (PAC@Fe3O4-MN) for the removal of ciprofloxacin (CIP) was extensively studied using batch experiments. First, PAC@Fe3O4-MN was synthesized and prepared by co-precipitation method, then it was subjected to characterization study using advanced techniques. Then, the adsorption ability of PAC@Fe3O4-MN for CIP was determined at different initial CIP concentration (10–100 mg/L), pH (3–11), PAC@Fe3O4-MN dose (0.1–0.6 g/L), shaking speed (50–300 rpm), contact time (0–120 min) and temperature (283–328 K). Results showed that PAC@Fe3O4-MN possessed excellent adsorptive properties and had a high practical utility. It was found that PAC particles were partially covered during the magnetization by Fe3O4-MN whereas the surface and morphological properties of both were detected in the characterization analysis of PAC@Fe3O4-MN. Values of the thermodynamic and isotherm parameters (negative $$\Delta {G}^{o}$$ ; positive $$\Delta {H}^{o}$$ , and values of KF and B) indicated that CIP adsorption process onto PAC@Fe3O4-MN was favorable, spontaneous and endothermic. Kinetic and isotherm studies manifested that the interaction of CIP with PAC@Fe3O4-MN occurs via both chemical and physical reactions onto a single and homogeneous layer of active sites of PAC@Fe3O4-MN. Furthermore, the rate-controlling step of the kinetic reaction is dominated and controlled by film diffusion for all CIP concentrations that studied. PAC@Fe3O4-MN possessed an excellent adsorption capacity for CIP (109.833 mg/g at pH 7, PAC@Fe3O4-MN dose = 1 g/L, shaking speed = 200 rpm, initial CIP concentration = 100 mg/L, contact time = 60 min, and temperature = 298 K). Finally, the used adsorbent appeared to be sustainable and cost-effective for treatment of CIP laden wastewater, as it can be successfully recycled up to eight consecutive adsorption–desorption cycles.