Preparation of tetrasulfide-functionalized silica particles by hydrothermal assisted grafting method for removal of lead (II) via dynamic solid phase extraction

In the present work, the tetrasulfide-functionalized silica (TFS) was prepared by a hydrothermal assisted grafting method for removing Pb(II) from aqueous solutions. The material was characterized by FTIR, SEM, EDS and TGA. Adsorption isotherm and kinetics studies were carried out in batch adsorption experiments. The result showed that the adsorbent had a maximum adsorption capacity of 142.79 mg/g. Furthermore, TFS was investigated to remove Pb(II) by a column study at different factors such as flow rates, initial metal ion concentrations, adsorption temperature and bed height. The experimental data can be well fitted by Thomas model, offering some model parameters for the process design. In addition, compared with that adsorbent prepared by thermal refluxing method, TFS has a better performance in capacity and flowing state in the column study. In the end, the competitive adsorption of coexisting ions was also discussed. Meanwhile, the adsorbent possessed with superior regenerative property has been successfully applied in the removal of Pb(II) in natural water sample with a satisfactory result. (C) 2015 Elsevier B.V. All rights reserved.