Sustainable Extraction Of Rare Earth Elements From Mine Tailings using Immobilized Extremophilic Red Algae

The demand for Rare Earth Elements (REEs) has significantly increased due to their vital role in the green energy transition, yet their extraction and purification pose significant environmental challenges. REEs are essential in various technological and industrial advancements, including wind turbines, generators, nuclear reactor shields, computers, and motors in hybrid or electric vehicles (EVs). Mining companies face mounting pressure to extract low-grade ore to meet the growing demand for REEs, resulting in larger quantities of tailings. These tailings contain REEs like heavy metals found in trace amounts in living organisms, leading to concerns about emerging chemical contaminants in several countries. The study delves into the possibility of using the immobilized extremophilic microorganism Galdieria sulphuraria to extract REEs from aqueous solutions. The immobilization with sodium alginate modifies the surface of Galdieria sulphuraria with functional groups or surface charges for REE extraction The effectiveness of immobilized Galdieria sulphuraria in REE removal was examined through bench-scale experiments conducted in a controlled laboratory setting. Analytical techniques such as Energy Dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Allen medium, and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) were utilized to evaluate the efficiency of REE extraction and clarify the underlying mechanisms. The preliminary results from other research groups show the promising capabilities of immobilized Galdieria sulphuraria in sequestering REEs from solution, potentially offering a sustainable and environmentally friendly approach to REE recovery. More optimization and scale-up investigations are necessary to investigate the practical application of this biotechnological technique in REE extraction and resource recovery.