Vanadium (V) Adsorption from Aqueous Solutions Using Xerogel on the Basis of Silica and Iron Oxide Matrix.

Vanadium is considered a strategic metal with wide applications in various industries due to its unique chemical and physical properties. On the basis of these considerations, the recovery of vanadium (V) is mandatory because of the lack of raw materials. Various methods are used to recover vanadium (V) from used aqueous solutions. This study develops a clean and effective process for the recovery of vanadium (V) by using the adsorption method. At the same time, this study synthesizes a material starting from silica matrices and iron oxides, which is used as an adsorbent material. To show the phase composition, the obtained material is characterized by X-ray diffraction showing that the material is present in the amorphous phase, with a crystal size of 20 nm. However, the morphological texture of the material is determined by the N 2 adsorption-desorption method, proving that the adsorbent material has a high surface area of 305 m 2 /g with a total pore volume of 1.55 cm 3 /g. To determine the efficiency of the SiO 2 Fe x O y material for the recovery of vanadium through the adsorption process, the role of specific parameters, such as the L-to-V ratio, pH, contact time, temperature, and initial vanadium concentration, must be evaluated. The adsorption process mechanism was established through kinetic, thermodynamic, and equilibrium studies. In our case, the process is physical, endothermic, spontaneous, and takes place at the interface of SiO 2 Fe x O y with V 2 O 5 . Following equilibrium studies, the maximum adsorption capacity of the SiO 2 Fe x O y material was 58.8 mg (V)/g of material.