Abstract
•Beta-cyclodextrin modified magnetic chitosan showed strong self-assemble ability toward phenolic compounds.•More water-compatible imprinting sites were generated in the surface of imprinted layer.•Langmuir isotherm and pseudo-second-order kinetic model described the selective adsorption well.•The as-prepared MMIP exhibited higher adsorption capacity and selectivity toward target molecule.
Beta-cyclodextrin modified magnetic chitosan molecularly imprinted polymer (MMIP) was successfully synthesized via covalent modification and self-assembly polymerization for selective removal of bisphenol A (BPA) from wastewater. To obtain more water-compatible imprinting sites, chitosan and beta-cyclodextrin were introduced as functional monomer of polymerization process. The provided multifunctional ligand containing –NH2, –OH and hydrophobic cavity enhanced the capture capability toward target molecule. The as-prepared MMIP was evaluated and characterized by scanning electron microscopy, Fourier transform infrared analysis, x-ray diffraction and vibrating sample magnetometry. Pseudo-second-order kinetic and Langmuir isotherm mode fitted the experimental data better than other models. The optimal adsorption was observed at pH=6 with the highest binding capacity of 105.5mg/g at 298K. The initial adsorption rate of MMIP was 7.062mg/g min, and adsorption equilibrium was reached in less than 60min. Moreover, MMIP showed significantly selective binding capacity to BPA over other structurally related phenolic compounds. Regenerative study demonstrated that no obvious decline of removal capacity was observed after several cycles. Therefore, MMIP could be expected to be a promising candidate for selective removal of target pollutant from aqueous solution.
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