Investigation of Pb (II) and Cd (II) removal from aqueous solution by organic-modified xonotlite

Abstract

In this work, a novel xonotlite nanocomposite was synthesised with abandoned eggshell by hydrothermal method, and organic-modified with toluene diisocyanate (TDI) for the removal of Pb(II) and Cd(II) from wastewater. The xonotlite and organic-modified xonotlite were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunner-Emmet-Teller (BET) and Fourier transform infrared spectroscopy (FTIR) methods. The effect of solution pH, contact time, adsorbent dose, and initial concentrations were also investigated. The organic-modified xonotlite was found to have a high loading capacity of 467.7 mg g⁻¹ for Pb(II) and 147.6 mg g⁻¹ for Cd(II). The adsorption of Pb (II) and Cd (II) was well fitted by Freundlich model and pseudo-second order model. In the effect of the competing ion, the ions like Na(I) and K(I), had little effect on the Pb(II) and Cd(II) removal efficiency. Furthermore, the organic-modified xonotlite can be reused and shown good recyclability. It was concluded that the organic-modified xonotlite is simple, fast and effective adsorbent for the removal of Pb(II) and Cd(II) in treating wastewater with outstanding adsorption capacity.