Abstract
The present study reports the synthesis of a polydopamine (PDA)/nanocellulose (NC) nanocomposite for the effective removal of chromium ions from water. PDA was used to modify NC surface producing a nanocomposite namely PDA/NC, by
polymerization of dopamine on the surface of NC. Thereafter, the as-synthesized nanocomposite was characterized using familiar techniques such as Fourier transform infrared, X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopy, and transmission electron microscopy. All results indicated the successful combination of PDA and NC in one nanocomposite. The PDA/NC nanocomposite was evaluated for the removal of hexavalent Cr(
) ions from an aqueous solution. The adsorption conditions, such as pH, contact time, and initial Cr(
) concentration, were optimized. Adsorption kinetic studies revealed that Cr(
) removal on the surface of PDA/NC nanocomposite followed the pseudo-second-order kinetic model. Furthermore, isotherm studies revealed that Cr(
) removal followed the Langmuir isotherm model with a maximum adsorption capacity (
) of 210 mg/g. The adsorption mechanism study indicated that the Cr(
) removal was reached via complexation, adsorption, and chemical reduction. The reusability of a PDA/NC nanocomposite for the removal of Cr(
) ions was studied up to five cycles with acceptable results. The high adsorption capacity and multiple removal mechanisms validated the effective applicability of PDA/NC nanocomposite as a useful adsorbent for the removal of Cr(
) ions from aqueous solution.