AQUEOUS CADMIUM ION REMOVAL BY FUNCTIONALIZED SBA-15 MATERIALS

Mesoporous silica material SBA-15 with highly ordered pore structure was synthesized via a hydrothermal method. The as-synthesized mesoporous materials were functionalized with 3-mercaptopropyltrimethoxysilane and 3-aminopropyltrimethoxysilane to graft the groups of SH and NH(2), respectively. Structures of the materials were characterized by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), nitrogen adsorption-desorption and thermogravimetric analysis (TGA). The results of adsorption experiments showed that both of the modified mesoporous adsorbents exhibited excellent ability to remove cadmium ions from aqueous solution, while the adsorption ability was affected by contact time, pH and initial concentration of cadmium ions. The adsorption isotherm mechanism followed Langmuir model very well. The maximum adsorptive capacity of SH-SBA-15 is bigger than that of NH(2)-SBA-15 under the same conditions.