Influence of functionalization, surface area and charge distribution of SBA15-based adsorbents in Co (II) and Ni (II) removal from aqueous solutions

P. RODRÍGUEZ-ESTUPIÑÁN; S. LEGNOVERDE; S. SIMONETTI; L. GIRALDO; A. DIAZ COMPAÑY; A. JUAN; J. C. MORENO-PIRAJÁN; E. BASALDELLA

Journal of Environmental Chemical Engineering

ELSEVIER

Año: 2020 vol. 8 p. 103671 - 103679

2213-3437

Functionalized solids with amino groups (-NHx) were obtained from a mesostructured silica type SBA-15 and the anchorage of molecules of ethoxysilaneand EDTA. The materials were characterized by nitrogen adsorption-desorption, Fourier transform infrared spectroscopy (FTIR), and potentiometric titration.The samples SBA-15, SBA-15 -NH2 and SBA-15-EDTA were tested in the simple and competitive adsorption of Co (II) and Ni (II) ions from aqueous solutions.The equilibrium data were analyzed using the Langmuir isotherm by nonlinear regression analysis. The influence of textural and chemical characteristics of the three different silices for the removal of cobalt and nickel from aqueous solution was studied. A complementary DFT study was performed. A detailed data analysis demonstrated that EDTA functionalization allows the best removal efficiency for both heavy metals and that in the case of the adsorption of binary solutions both cations compete for the same active sites, observinga preferential adsorption of the Ni ion.