Mechanistic investigation of ciprofloxacin recovery by magnetite-imprinted chitosan nanocomposite: Isotherm, kinetic, thermodynamic and reusability studies

Recovery of antibiotics from water and wastewaters has recently gained a great deal of attention due to their serious health and environmental problems. In this work, a magnetite imprinted chitosan polymer nanocomposites (Fe-CS NCs) were synthesized and applied for the adsorptive removal of ciprofloxacin (CIFO) as a model fluoroquinolone antibiotics. The composition and surface morphology of Fe-CS NCs were studied by SEM, BET, XRD, TEM, FTIR and zeta potential meter. Modelling and optimization of adsorption process were studied using response surface methodology (RSM). The reliability of the RSM models was tested by fitting the data. A comparative analysis of the results derived from the models demonstrated that the second-order model was the best. From the contour plotting results, at pH < pH(iep) low adsorption rate was observed due to protonation of the chitosan NH2 groups, whereas the adsorption rate was significantly enhanced and achieved to a maximum level at pH 6 due to the electrostatic interactions and hydrophobic interactions. Under optimum conditions, maximum removal efficiency and maximum adsorption capacity were obtained 68% and 142 mg/g, respectively. Well regenerability of Fe-CS together with its high capacity of fluoroquinolone antibiotics removal provide a promisable strategy to remediation of wastewaters. (C) 2019 Elsevier B.V. All rights reserved.