Preparation and Characterization of a Novel Amidoxime-Modified Polyacrylonitrile/Fly Ash Composite Adsorbent and Its Application to Metal Wastewater Treatment

Abstract

The polyacrylonitrile/fly ash composite was synthesized through solution polymerization and was modified with NH2OH·HCl. The amidoxime-modified polyacrylonitrile/fly ash composite demonstrated excellent adsorption capacity for Zn2+ in an aqueous medium. Fourier transform-Infrared spectroscopy, thermogravimetric analysis, nitrogen adsorption, X-ray diffraction, and scanning electron microscopy were used to characterize the prepared materials. The results showed that the resulting amidoxime-modified polyacrylonitrile/fly ash composite was able to effectively remove Zn2+ at pH 4–6. Adsorption of Zn2+ was hindered by the coexisting cations. The adsorption kinetics of Zn2+ by Zn2+ followed the pseudo-second order kinetic model. The adsorption process also satisfactorily fit the Langmuir model, and the adsorption process was mainly single layer. The Gibbs free energy ΔG0, ΔH0, and ΔS0 were negative, indicating the adsorption was a spontaneous, exothermic, and high degree of order in solution system.

Study of the removal of Pb(ii) and Ni(ii) from aqueous solution by new nano-Mg(OH)2/fly ash adsorbent materials

“…Zero-valent Fe/Ni fly ash zeolite foam was formed using a freeze-drying method, and the removal of copper (2+) ions [Cu( ii )], pentavalent arsenic [As( v )], mercury (2+) ions [Hg( ii )], and hexavalent chromium [Cr( vi )] heavy metal ions from industrial wastewater was studied using continuous column flow experiments. Sun et al 7 used solution polymerization to form polyacrylonitrile/fly ash composites. Hydroxylamine and Na 2 CO 3 were used to modify the polyacrylonitrile/fly ash materials to obtain an amidoxime-modified polyacrylonitrile/fly ash composite adsorbent, which was then used to remove heavy metal zinc ions from aqueous solutions.…”