Selective Removal of Arsenic(V) from Aqueous Solution Using A Surface-Ion-Imprinted Amine-Functionalized Silica Gel Sorbent

A new surface-ion-imprinted amino-functionalized silica gel sorbent was prepared by the surface imprinting technique with As(V) as the template, 3-(2-aminoethylamino)propyltrimethoxysilane as the functional monomer, silica gel as the support, and epichlorohydrin as the cross-linking agent and was characterized by FTIR, SEM, nitrogen adsorption, and the static adsorption–desorption experiment method. The results showed that the maximum static adsorption capacity of the imprinted silica gel sorbent was 16.1 mg·g –1, the adsorption equilibrium could be reached in 20 min, there was no influence of pH values on adsorption capacity of the imprinted silica gel sorbent in the range of 3.7–9.2, and the imprinted silica gel sorbent could be used repeatedly and indicated high selectivity even in the presence of the other metal ions. The Langmuir adsorption model was more favorable than the Freundlich adsorption model. Kinetic studies indicated that the adsorption followed a pseudosecond-order model. Various thermodynamic parameters such as Δ G o, Δ H o, and Δ S o were evaluated with results indicating that this system was a spontaneous and endothermic process.