Adsorption of Ni(II) from Aqueous Solution by Polyaminated Crosslinked Ni(II)-Imprinted Chitosan Derivative Beads

Polyaminated crosslinked Ni(II)-imprinted chitosan derivative [P-C-CTS (Ni)] beads were first synthesized by molecular imprinting, crosslink reactions, and polyamination methods. Structure, size, and shape, and doping level of the adsorbents were analyzed in detail by X-ray photoelectron spectroscopy data, scanning electron microscope images, and Fourier transform infrared spectra. Study of Ni(II) adsorption on the prepared P-C-CTS (Ni) beads gave evidence that chemisorption was the main sorption mechanism and adsorption kinetics were fitted with a pseudo-second-order model. The adsorption capacity of 2.746 mmol/g for Ni(II), which was 2.6 times higher compared with unpolyaminated beads, was achieved by using the prepared P-C-CTS (Ni) beads. According to the results of Ni(II) adsorption quantities with different Ni(II)/citrate ratios (1:2, 1:1, 2:1) and pH (2.0, 3.0, 4.0, 5.0, 6.0), the effects of the pH and citrate ligands on Ni(II) adsorption quantities and the micromechanism of adsorption were discussed. The adsorption capability of the prepared P-C-CTS (Ni) beads was stable up to eight adsorption-desorption-regeneration cycles.