Adsorption of Co(II) and Mn(II) Ions on Mesoporous Silica SBA15 Functionalized with Amine Groups

Abstract

The adsorption characteristics of Co(II) and Mn(II) ions on mesoporous silica SBA15 were investigated. SBA15 was synthesized from the silicate precursor tetraethyl-orthosilicate (TEOS), and it was functionalized with ethylene-diamine-tetra-acetic-acid (EDTA) and N,N-dimethylacetamide (DMAC), which consists of the amine functional groups. It was also characterized by nitrogen adsorptiondesorption analysis, element analysis (EA), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The adsorption capacities of EDTA functionalized SBA15 for Co(II) and DMAC functionalized SBA15 for Mn(II) in a single component system were found to be 10.12 mg/g and 6.8 mg/g, respectively. These values are about 10 times higher than that of assynthesized SBA15. The adsorption isotherms and kinetics data were found to follow the Langmuir adsorption isotherm model and the Pseudosecond order kinetic model (r 2 > 0.99). After the 5 adsorption cycles, over 90% regeneration efficiency was achieved for the functionalized SBA15, which would be applied for recovery of the metals.

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

“…Corresponding to Figs. 2 and 5, the cylindrical and hexagonal mesopore structures of MS3 and MS4 are maintained because the shape of the type IV isotherms and H1 hysteresis loops are similar to MS1 and MS2 (Han et al, 2012b;Kim et al, 2014;Zhu et al, 2011). This result indicated that there are amounts of organic moieties of the functionalized SBA-15 MS3 and MS4 due to the functionalization.…”

“…The yield of Si extracted from the mine tailing under the experimental condition was calculated by accounting the amount of Si in the mine tailing and the amount of Si actually dissolved in the supernatant which was found to be 91.8%. Kim et al, 2014;Zhu et al, 2011). Fig.…”

“…According to a recent research, the metal removal efficiency of surface-modified mesoporous silica increased due to the presence of the functional groups (Heidari et al, 2009;Kim et al, 2014;Mureseanu et al, 2008;Wu et al, 2010).…”

“…The samples were evacuated in a high vacuum overnight at 300°C before each measurement. The specific surface area was assessed from nitrogen adsorption data in the partial relative pressure range of 0.05-0.25 using the Brunauer-Emmett-Teller (BET) method, and the pore size distributions were analyzed using the Barrett-Joyner-Halenda (BJH) method (Kim et al, 2014;Han et al, 2012a). The morphology and microstructure of the samples were investigated using FE-SEM (JSM-6701F, JEOL).…”

“…Mesoporous silicas with high surface have found applications in various fields, such as catalysts, sensors and adsorbents (Aguado et al, 2009;Alothman and Apblett, 2010;Kim et al, 2011Kim et al, , 2014Li et al, 2011;Machida et al, 2012;Majchrzak-Kucęba and Nowak, 2011). Among mesoporous silicas, SBA-15 has drawn considerable attention as an absorbent for metals due to its high specific surface area, N800 m 2 /g (Aguado et al, 2009;Kim et al, 2011).…”