Highly efficient entrapping and recovery of gadolinium and samarium ions by nano cerium orthovanadate from acidic solutions

Abstract

Cerium orthovanadate nano-rods were prepared using template free-low temperature procedure and tested for their potential use in the entrapping of lanthanide ions. The adopted preparation procedure yielded in the production of uniform nano-rods with respectively smaller dimensions compared to other methods that utilize higher crystallization temperature and/or template. The material was fully characterized using HRTEM/SAED, SEM, FTIR, XRD to determine its crystalline structure and morphological characteristics. The material has buffer ability in acidic solutions and notable stability in different alkaline and acidic eluents. Gd and Sm ions entrapping performances are optimum in the acidic solutions in pH range (2.5 ≤ pH ≤ 6) with suitable control to avoid negative perturbation in the solution pH. The results of the direct sensitivity analysis for operating the process at room temperature indicate that Sm entrapping is more sensitive than Gd ions. The entrapping is controlled by multiple mechanisms that involve sorption on the external surface and diffusion into the interior pore structure of the material. The material has higher affinity toward Gd ions entrapping and recovery, and its monolayer capacity is higher than that reported in the literature for actinides removal. The material could be efficiently regenerated and reused for 5 cycles without considerable loss in the efficiency. This novel material and its efficient entrapping and recovery potential for Gd and Sm ions provides innovative application of orthovanadate materials to enhance the extraction of lanthanides from acidic solutions and improve the control on the release of these emerging contaminant into the ecosystem.