Removal of ciprofloxacin from aqueous solution by a magnetic chitosan grafted graphene oxide composite

A novel magnetic chitosan grafted graphene oxide nanocomposite (MCGO) was prepared and characterized using vibrating sample magnetometer (VSM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), and Brunauer Emmett Teller (BET) surface area. The adsorption performance and mechanisms of MCGO for the removal of ciprofloxacin (CIP) from water were evaluated. Adsorption kinetics followed the pseudo-second-order model. The adsorption isotherms data was well described by both Freundlich model and Langmuir model. The isotherm results showed that the maximum adsorption capacity (q(m)) was 282.9 mg g(-1). The initial solution pH and ionic strength significantly influence the CIP adsorption. The removal efficiency decreased at pH 7 and 9. The presence of Na (200 mM) and Ca (10 mM) significantly reduced the adsorption of CIP. The adsorption of CIP was mainly controlled by electrostatic attraction and n-n electron interaction. Moreover, MCGO could be reused after the regeneration treatment and the removal capacity was about 72% of the initial adsorption capacity after being used four times. (C) 2016 Elsevier B.V. All rights reserved.