The xonotlite was synthesized from eggshell waste and modified with toluene diisocyanate (TDI). The xonotlite and amidoxime-modified xonotlite were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). FTIR revealed that the amidoxime group was successfully grafted onto the xonotlite. Factors affecting adsorption such as solution pH, adsorbent dose, contact time, and initial concentrations were set up to improve the adsorption performance. The adsorption of Cu (II) on all the adsorbents was well-described by the Freund...
