Adsorption of binary and multi heavy metals ions from aqueous solution by amine functionalized SBA-15 mesoporous adsorbent in a batch system

Mesoporous silica material Santa Barbara Amorphous-15 (SBA-15) and functionalized SBA-15 with amino functional group were synthesized in order to investigate its potential use as an adsorbent for adsorption of binary and multi heavy metals ions from aqueous solution. The characteristics of SBA-15 before and after functionalization were achieved, such as Brunauer-Emmett-Teller (BET) surface area and thermal gravimetric analysis (TGA). The adsorption of binary system consisting of Ni(II) and Co(II) on NH2-SBA-15 was investigated, it was found that the percentage removal for Ni(II) ions in binary system was less than in single system by 64.67% which confirms the presence of competition between these ions, and the effect was much clearly in higher concentrations. The competitive adsorption for six metals ions on NH2-SBA-15 was studied, and it was obtained that the adsorbent had an attraction toward metal ions in reducing order as follows: Pb2+ > Cr3+ > Cu2+ > Cd2+ > Ni2+ > Co2+ which show that Pb was the most adsorbed metal at NH2–SBA-15. It was also found that the Ni2+ adsorption efficiency acquired from the single-metal aqueous solution (99%) better than in multi-metals aqueous solution (42%), indicating the presence of competition between the metallic elements for adsorption by NH2 groups.