Rare earth elements recovery via liquid membrane technology: Recent advances and application potential in Malaysia

The sustainable recovery of rare earth elements (REEs) is vital for high-tech industries and reducing the environmental burden of conventional mining. Liquid membrane (LM) systems have gained attention as an alternative, combining solvent extraction with membrane separation to deliver high selectivity, reduced chemical use, and process flexibility. This mini-review summarizes advances in LM-based recovery of REEs from secondary sources, including acid mine drainage, bauxite residue, end-of-life batteries, electronic waste, and industrial effluents. Challenges remain in handling dilute REE concentrations, competing ions, and ensuring long-term membrane stability. Recent developments in polymer inclusion membranes, supported ionic LMs, and bio-MOF-based nanocomposites show enhanced durability, sorption capacity, and potential scalability. In Southeast Asia, Malaysia's growing e-waste and bauxite reserves highlight opportunities, though LM research lags behind Vietnam and Thailand. Overall, LM represents a promising route for sustainable REE recovery, with further work needed on real wastewater adaptation and industrial scale-up. • Liquid membranes offer selective and energy-efficient REEs recovery routes. • Case studies show potential for REEs recovery from Southeast Asia resources. • Carrier chemistry and stability are key to membrane performance. • Highlights knowledge gaps hindering scale-up and industrial application • Outlines future directions for greener and more sustainable REEs separation.