Inorganic sorbents based on magnesium silicates obtained by two synthetic routes

In the present study, three novel inorganic ion exchange materials based on magnesium silicates were synthesized by precipitation and hydrothermal sol–gel methods with two reagents ratio. Physico-chemical properties of samples were characterized by thermogravimetric and differential thermal analyses, low-temperature adsorption/desorption method and transmission electron microscopic studies. It was found that all sorbents were obtained in a form of amorphous layer-structure magnesium silicates with micro- and mesoporous structures. The ion exchange properties of these materials for removing Cs + , Sr 2+ Cu 2+ , Co 2+ and Cd 2+ from the water solution were investigated. Data obtained showed that magnesium silicate obtained by precipitation has the higher capacity towards the heavy metal cations compared to the radionuclides regardless of the method used for synthesis. The sample synthesized with excess of metasilicate exhibited the higher efficiency of heavy metal cations sorption than the sample obtained using equimolar ratio of components. Among Langmuir, Freundlich and Dubinin–Radushkevich models, Langmuir model fitted well for experimental data received on these adsorbents.