Effective adsorption of phenolic pollutants from water using beta -cyclodextrin polymer functionalized Fe3O4 magnetic nanoparticles

beta -Cyclodextrin polymer functionalized magnetic nanoparticles (CDP-MNPs) were prepared with a one-step co-precipitation method by anchoring a carboxymethyl- beta -cyclodextrin polymer (CDP) onto the surface of Fe3O4 magnetic nanoparticles (MNPs). The CDP-MNPs possess the fascinating features of superparamagnetism and adsorption properties, which are favorable for the purpose of removing bisphenol A and resorcin. The maximum adsorption capacity for bisphenol A could reach values up to 74.63 mg g-1 at 25 degree C, which is higher than those of previously reported magnetic adsorbents. Moreover, for the removal of resorcin by CDP-MNPs, the maximum uptake amounted to 114.91 mg g-1 under the same conditions. The adsorption kinetics and isotherm data fitted well with a pseudo-second-order kinetic model and the Langmuir isotherm, respectively. The CD polymer grafted onto the MNPs enhanced the adsorption capacity because of the host-guest interaction of cyclodextrin and the hydrogen bonding of the polymer network with the phenolic compounds. Additionally, a good recyclability of the CDP-MNPs was observed over three usage cycles, with only a slight decline in adsorption capability.