Novel nanocomposite materials for efficient and selective mercury ions capturing from wastewater

This work explored the particulate ligand impregnated highly ordered mesoporous silica based optical nanocomposite material for the sensitive and selective detection and removal of mercury (Hg(II)) from polluted water solutions. The ligand of N,N-disalicylidene-4,5-dimethyl-phenylenedene was prepared and successfully anchored onto the highly ordered mesoporous silica by the indirect approach in the preparation of nanocomposite materials. The materials were produced an optical color signal that was easily generated and transduced even at trace levels of Hg(II) ions. Considering the environmental factors, the nanocomposite materials were solvent-free systems for sensitive Hg(II) ions detection system. Adding of Hg(II) ions, the nanocomposite materials generated absorption peak and enhance the selective chromogenic behavior toward Hg(II) ions from pale yellow to dark read, which could be easily visualized by the naked eye. The ability to remove Hg(II) ions by the materials was performed relatively to different experimental parameters such as solution pH, reaction time, initial metal ions concentration and different competing metal ions. The Hg(II) ions adsorption reached an equilibrium within short time and the maximum monolayer adsorption capacity was 179.74 mg/g. Also the foreign ions did not any significant affect for selective Hg(II) ions removal from water solutions under the optimum conditions. The elution was performed and the regeneration was possible during the elution operation. In addition, the nanocomposite materials could to reuse in several cycles without loss of structural ordering, permitting the reusability for further selective detection and separation of Hg(II) ions from water. In terms of the sensitivity and selectivity, the nanocomposite material is a promising candidate employed for in situ environmental pollution incidents, especially competent for the detection and removal of Hg(II) ions with an extremely high efficiency. (C) 2016 Elsevier B.V. All rights reserved.