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-dimethyl-acetamide (DMAC), which consists of the amine functional groups. It was also characterized by nitrogen adsorption–desorption 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 as-synthesized SBA15. The adsorption isotherms and kinetics data were found to follow the Langmuir adsorption isotherm model and the Pseudo-second order kinetic model (r2 > 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.
