The sustainable and efficient recovery of rare earth elements (REEs) from bioresource streams such as algae without impacting the biofuel production can provide additional revenue and increase REE supply chain resilience. In this study, water-stable metal-organic frameworks (MOFs) functionalized with chelating agents were used to concentrate REEs from leaching streams derived from specially cultivated algae. Adsorption equilibrium and kinetic were studied through batch adsorption experiment followed by the quantification of REE using Inductively coupled plasma mass spectrometry (ICP-MS). Surface area and functional groups were studied for their impact on the REE adsorption. Equilibrium adsorption capacities and kinetic constants were estimated using the pseudo-second-order model. The impact of the chelating agent was also investigated, and the necessity of having a chelating agent to adsorb REE complex was confirmed. Adsorbed REEs or REE complexes were removed from the MOF adsorbent through desorption using 0.1 M HCl. The results reveal that MOFs functionalized with chelating agents can achieve an REE concentration factor of up to 100 times, significantly outperforming conventional extraction methods. This approach highlights the potential of MOFs in establishing a greener and more efficient pathway for REE recovery from bioresources.
