Adsorption characteristics of mesoporous silica SBA-15 synthesized from mine tailing

Abstract

Mesoporous silica SBA-15 was successfully synthesized using the silicate solution extracted from mine tailings. The synthesized SBA15 was functionalized with 3-mercaptopropyl-trimethoxysilane, which was characterized by nitrogen adsorption-desorption analysis, Fourier transform infrared spectroscopy, element analysis, and transmission electron microscopy. The properties of the synthesized mesoporous materials were compared with those prepared from silica precursor tetraethyl-orthosilicate. The functionalized SBA-15 was tested as adsorbents to remove metal ions from aqueous solution. The highest adsorption capacities were found to be 33.25 mg/g of Cu(II), 20.98 mg/g of Cd(II) and 35.04 mg/g of Pb(II) for the functionalized SBA-15 synthesized from mine tailings. The results of adsorption of the functionalized adsorbents were successfully fitted to the Langmuir adsorption isotherm and pseudo-second order kinetics model (R-2>0.99).