Preparation and characterization of new hybrid organic-inorganic nanoporous silica for removal of CuII, PbII and CdII from aqueous media

Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran E-mail : Syedwaqifhusain@yahoo.com Fax : 98-21-4486-9761 Research Laboratory of Nanoporous Materials, Faculty of Chemistry, Iran University of Science and Technology, Farjam Street, Narmak, Tehran 16846, Iran Manuscript received online 10 June 2014, revised 11 August 2014, accepted 06 September 2014 Amino functional nanoporous silica MCM-48 materials have been synthesized to develop efficient adsorbents of heavy metals in wastewater. Functionalization with amino groups such as 3-(trimethoxysilyl)propyl amine (TMSPA) and tetraethylenpentamine (TEPA) has been carried out by using the grafting method. Powder X-Ray Diffraction (XRD), nitrogen adsorption-desorption and Fourier transform infrared (FT-IR) spectroscopy methods were performed to gain an understanding of the structure and surface properties of the nanoporous silica materials. Metal removal from aqueous solution has been examined for CuII, PbII and CdII. It was found that amino-modified ordered nanoporous silica materials show significant adsorption for heavy metals. The effect of various parameters was conducted to study the adsorption of heavy metal ions onto MCM-48 modified with amine group from an aqueous solution for the effect of pH and contact time in batch systems. The kinetic analysis indicated that the adsorption process was successfully fitted with the pseudo-first order kinetic model. Langmuir and Freundlich models were used for a mathematical description of the adsorption isotherm. The equilibrium process was explained well by the Freundlich isotherm