Removal of Tellurium(IV) from environmental aquatic systems using metal-organic framework material MIL-100(Fe)

Abstract

Metal-organic framework (MOF) materials, characterized by their porosity and large specific surface areas, exhibit excellent adsorption properties. With the aim of removing Te(IV) from environmental aquatic systems, this study is the first to propose the use of MIL-100(Fe). The material reveals a strong adsorption capacity for Te(IV), with maximum adsorption of 531.9 mg/g, superior to other adsorbent materials. Adsorption isotherm models and kinetic models indicate that the adsorption process of Te(IV) primarily involves monolayer chemical adsorption. According to the thermodynamic parameters of Te(IV) adsorption on MIL-100(Fe), the adsorption reaction is endothermic. The experiment individually examined factors affecting the material's adsorption performance, including adsorbent dose, initial concentration of Te(IV), pH, adsorption time, and coexisting ions. Even under high ion strength conditions and high concentrations of coexisting ions, the material's adsorption efficiency for Te(IV) still reached over 95%. The material has been successfully applied to remove Te(IV) from lake water, river water, and seawater, yielding satisfactory results. Due to the high salinity and ionic strength of the solution, the removal efficiency of Te(IV) in the seawater matrix was slightly lower than that in freshwater (river and lake water). Thus, this material shows promise for the removal of Te(IV) from complex aquatic systems.