Fluoride removal using a MgFe hydrotalcite and a MgFe oxide

The present study investigates the adsorption of fluorides (F) by a hydrotalcite MgFe (HT MgFe) and an iron-based metal oxide (MgFe oxide). Both materials were synthesized by the coprecipitation method and were calcined at the same temperature HT MgFe, HTC MgFe, oxide MgFe and oxide MgFeC. Both solids were characterized by the XRD technique. Materials showed typical crystalline forms; in the case of HT MgFe, an octahedral crystalline form and for the oxide MgFe cubic crystalline form, the analysis of the BET method classifies the materials as mesoporous. In the adsorption study, it was determined that the optimal pH for adsorption is 7. Regarding the adsorption kinetics, the HTC MgFe and oxide MgFeC samples were adjusted to the pseudo-second order model, which describes the process as chemiadsorption; meanwhile, for the samples, isotherms were adjusted to the Langmuir model, which describes the material as homogeneous with a strong interaction between the sorbate and the sorbent.