Application of mesoporous SBA-15 silica functionalized with 4-amino-2-mercaptopyrimidine for the adsorption of Cu(II), Zn(II), Cd(II), Ni(II) and Pb(II) from water

Abstract

This work reports the sol-gel synthesis of an SBA-15 silica and its functionalization with 4-amino-2-mercaptopyrimidine to perform adsorption of metal species from aqueous media. The functionalization of the material was confirmed using FTIR and specific surface area measurements. The final material was tested through batch experiments to uncover its adsorptive properties toward the adsorption of Cu(II), Cd(II), Zn(II), Pb(II), and Ni(II). Contact time and pH conditions were investigated, and the material presented slow adsorption kinetics, which was best described by the pseudo-second order model. In addition, at pH 5-6, the adsorption of the metal ions was favored. Under optimized conditions, the material had its maximum adsorption capacities determined for all metal species studied, and the obtained values were 13.0 μmol g -1 for Zn(II), 12.3 μmol g -1 for Cu(II), 3.45 μmol g -1 for Ni(II), 2.45 μmol g -1 for Pb(II), and 0.60 μmol g -1for Cd(II). The capacity differences between each metal ion were discussed in terms of their ionic radii and Person's soft/hard acids/bases concept.

Preconcentration of ultra-traces of Cu(II) in water samples using SBA-15 sorbent modified with a thiocarbohydrazide ligand prior to determination by flame atomic absorption spectrometry

“…Once in the environment, metals may be disturbed through water, soil and the atmosphere to the most remote places in the world, posing risk to human and wild life health. 1,2 Among the heavy metals that exist in the environment, copper is very critical because copper is known as an important element in industry and biological systems. It is an essential nutrient to high plants and animals and is a co-factor in various enzymes.…”