Preparation of SBA-15 mesoporous silica grafted with bis-salicylaldehyde Schiff base for uptake of Pb(II) and Cu(II) from water

Abstract

SBA-15 type mesoporous silica modified with bis-salicylaldehyde Schiff base (SBA-DSA) was developed for the Pb(II) and Cu(II) ions removal from water. The adsorption properties of SBA-DSA were also compared with SBA-15 decorated with mono-Schiff base (SBA-SA). Sorption of Pb(II) and Cu(II) on SBA-DSA and SBA-SA was pH-dependent and the optimum pH for adsorption was selected at pH 5.0. The pseudo-second-order kinetic model described the sorption process well. Besides, adsorption isotherm data were better represented by the Langmuir model, confirming the adsorption processes occurred on the monolayer. Maximum adsorption capacities of SBA-DSA were 60.9 mg g−1 for Pb(II) and 36.6 mg g−1 for Cu(II), which were higher than adsorption performance of SBA-SA. The synthesized SBA- DSA showed excellent adsorption selectivity for Pb(II) in mixed metal ions solution. Considering the good reusability and regeneration of the adsorbent, SBA-DSA prepared here is promising for decontamination of water solutions from heavy metal ions.