Melamine grafted chitosan-montmorillonite nanocomposite for ferric ions adsorption: Central composite design optimization study

Chitosan-based nanocomposites are considered to be promising candidates to for application in water treatment technology due to their distinguished physicochemical properties. In the present work, a new melamine grafted chitosan nanocomposite has been synthesized as an effective material for ferric ions adsorption. The nanocomposite has been synthesized via graft polymerization of chitosan using glutaraldehyde/epichlorohydrin crosslinkers in the presence of 0.1% of Nano-Montmorillonite (w/w % based on chitosan). Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques have been utilized for the characterization of the synthesized nanocomposite. Central composite design (CCD) of response surface methodology (RSM) has been applied for determination of the optimum conditions for the adsorption of ferric ions. Under the optimum conditions, the nanocomposite shows 99.97% for ferric ions removal percent with good reusability till third cycle. Kinetic, isothermal, and thermodynamic analyses have been studied to have deep insights into the mechanism of ferric ions adsorption on the synthesized nanocomposite. (C) 2019 Elsevier Ltd. All rights reserved.