Lanmodulin-Functionalized Magnetic Nanoparticles as a Highly Selective Biosorbent for Recovery of Rare Earth Elements

Abstract

Recovering rare earth elements (REEs) from waste streams represents a sustainable approach to diversify REE supply while alleviating the environmental burden. However, it remains a critical challenge to selectively separate and concentrate REEs from low-grade waste streams. In this study, we developed a new type of biosorbent by immobilizing Lanmodulin-SpyCatcher (LanM-Spycatcher) on the surface of SpyTag-functionalized magnetic nanoparticles (MNPs) for selective separation and recovery of REEs from waste streams. The biosorbent, referred to as MNP-LanM, had an adsorption activity of 6.01 ± 0.11 μmol-terbium/gsorbent and fast adsorption kinetics. The adsorbed REEs could be desorbed with >90% efficiency. The MNP-LanM selectively adsorbed REEs in the presence of a broad range of non-REEs. The protein storage stability of the MNP-LanM increased by two-fold compared to free LanM-SpyCatcher. The MNP-LanM could be efficiently separated using a magnet and reused with high stability as it retained ∼95% of the initial activity after eight adsorption−desorption cycles. Furthermore, the MNP-LanM selectively adsorbed and concentrated REEs from the leachate of coal fly ash and geothermal brine, resulting in 967-fold increase of REE purity. This study provides a scientific basis for developing innovative biosorptive materials for selective and efficient separation and recovery of REEs from low-grade feedstocks.

Genetic Modification of Acidithiobacillus ferrooxidans for Rare-Earth Element Recovery under Acidic Conditions

“…ferrooxidans under low pH bulk conditions (Figure ). This cellular buffering effect may be highly advantageous compared to the REE recovery via surface-displayed lanmodulin or other binding motifs at low pH. ,, This showcases an important potential advantage of using A. ferrooxidans and other acidophilic extremophiles for REE recovery.…”

Cryptands on a Solid Support for the Separation of Europium from Gadolinium

“…Different solid-phase extractants have been studied with respect to their selectivity for rare-earth elements. − Modifications to the solid supports studied for the isolation of rare-earth elements include changing the size of the pores, degree of crosslinking, and degree of functionalization as well as selection of different ligands or functional groups to include on solid supports. ,,, Modification of solid supports with ligands is an important technique to separate rare-earth elements based on coordinating angle (bite angle), donor atoms, functional groups, cavity size, range of p K a , or denticity. ,,, With increasing specificity of the supported ligand, increased separation efficiencies become possible. Therefore, we hypothesized that 2.2.2-cryptand covalently linked to a solid support would enable the separation of lanthanides from each other as a function of size and charge because 2.2.2-cryptand preferentially binds divalent lanthanides relative to trivalent lanthanides .…”

Nanoporous Metal–Organic Framework Adsorbent Constructed via Ligand Tailoring for Rare-Earth Metal Ion Recovery

“…Compared with those, adsorption exhibits the advantages of high efficiency, simple operation, and fewer byproducts . Some adsorbents such as mineral, carbon material, hydrogel, and biosorbent have emerged for RE metal ions capture in the previous decades, − while the adsorption capacity is still needed to improve largely.…”