Synthesis of Organic-Inorganic Hybrid Amine Based on Nanostructured Silicate Materials and Its Application for Removal of Heavy Metal Ions from Aqueous Solution

The heavy metals are nonbiodegradable that can accumulate in living tissues which cause cancers and neural problems in human. From an environmental health point of view, it is therefore necessary to remove them from aqueous solution and wastewater. In this research work, nanoporous silica SBA-15 was synthesized by hydrothermal method and then functionalized by three different concentrations of 3-aminopropyltriethoxysilane, namely 4 [(NH2(4mM)-SBA-15], 6 [NH2(6mM)-SBA-15] and 8 [NH2(8mM)-SBA-15] mM, in order to be used as adsorbent for lead, copper and cadmium ions removal. The materials have been characterized by means of X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), nitrogen adsorption-desorption, and FTIR spectroscopy. The results showed that the removal percentage was increased from 46.1 to 100 for lead, from 44.2 to 79.3 for copper and from 26.8 to 67.0 for cadmium with increasing concentration of amine groups from 4 to 8 mM. Thus, NH2(8mM)-SBA-15 was selected as an adsorbent in subsequent experiments. The effects of adsorbent dose, contact time, pH and initial concentration of metal ions on adsorption efficiency in batch system were studied. The experimental data were analyzed using the Langmuir and Freundlich isotherm models. Maximal equilibrium uptake capacity of 15.9 mg/g for lead, 13.1 mg/g for copper and 11.2 mg/g for cadmium was obtained. Consequently, the nano-structural adsorbent prepared has appropriate adsorption efficiency therefore it can be considered for the removal of heavy metal ions in future study