Adsorption of Phosphate by Amino-Functionalized and Co-condensed SBA-15

In this study, the applications of mesoporous materials based on silica, and those with modifications, namely post-synthetic grafting, co-condensation, and pure SBA-15, were investigated for the removal of phosphate from sewage. The mesostructures were confirmed by X-ray diffraction, Brunauer-Emmett-Teller, Fourier transform infrared spectroscopy, and transmission electron microscopy. The absorption of phosphate by the mesoporous adsorbents was examined, using different adsorption models to describe the equilibrium and kinetic data. The maximum adsorption capacities of the mesostructured adsorbents were found to be 69.970, 59.890, and 2.018 mg/g for the co-condensation, post-synthetic grafting, and pure SBA-15, respectively. The kinetic data showed that the adsorption of phosphate onto three different mesostructures followed the pseudo-first-order kinetic model.