Selective Removal of Uranium from Rare Earth Leachates via Magnetic Solid-Phase Extraction Using Schiff Base Ligands

Abstract

This study highlights a new type of extraction procedure combining a magnetic solid-phase support and a Schiff base ligand for the removal of uranium from rare earth leachates. After synthesizing and characterizing three Schiff base ligands (CH 3 Salen, H 2 Salophen, and MeOSalophen), they were combined with magnetic nanoparticles and assessed for the selective extraction of uranium. To optimize extraction, the effects of parameters such as the pH, the mass of the ligand, and extraction time, were explored. The maximum adsorption capacity for U(VI) using the magnetic MeOSalophen Schiff base was 63 ± 3 mg g −1 at pH = 6 with 25 mg of extracting agent for a contact period of 24 h. An acceptable extraction of U(VI) was also observed in more acidic conditions with a shorter extraction period. The magnetic ligand has shown a high selectivity toward U(VI) over a number of metals in a real rare earth element leaching solution.

Enhanced Versatility in Thorium Removal: Mesoporous Silica-Coated Magnetic Nanoparticles Functionalized by Phenanthroline Diamide as a Selective Adsorbent

“…The impact of lanthanides on the adsorption of Th­(IV) in the residual solution of hydrometallurgical lanthanide minerals is attributed to competitive adsorption. This phenomenon arises from the interaction between the adsorbent and the lanthanides . To evaluate the selective adsorption performance of SiO 2 @Fe 3 O 4 -DAPhen in the presence of lanthanides and Th­(IV), several lanthanides, including Ce­(III), Nd­(III), Sm­(III), Eu­(III), Gd­(III), and Yb­(III), were selected as representatives.…”

“…This phenomenon arises from the interaction between the adsorbent and the lanthanides. 70 To evaluate the selective adsorption performance of SiO 2 @Fe 3 O 4 -DAPhen in the presence of lanthanides and Th(IV), several lanthanides, including Ce(III), Nd(III), Sm(III), Eu(III), Gd(III), and Yb(III), were selected as representatives. SiO 2 @Fe 3 O 4 -DAPhen demonstrated outstanding selectivity for Th(IV) with high selectivity coefficients (S) at pH = 1−4.…”

Self-Assembled Naphthylidene-Containing Schiff Base Anchored Polystyrene Nanocomposites Targeted for Selective Cu(II) Ion Removal from Wastewater

“…22 Currently, increasing composite base on Schiff base molecules has been obtained for selective removal of trace heavy ion pollutants. 23,24…”

“…22 Currently, increasing composite base on Schiff base molecules has been obtained for selective removal of trace heavy ion pollutants. 23,24 Herein, we report a novel noncovalent self-assembly strategy based on the combination of sulfonate group charged polystyrene resin and naphthylidene-containing Schiff base (NSB) to design and engineer composite nanoadsorbents for selective removal of Cu(II) (Figure 1). In the resulting complex absorbents, the naphthylidene-containing Schiff base is inserted into the polystyrene both through π−π stacking between aromatic ring and naphthalene ring and electrostatic force between sulfonate groups and the protonated amino group.…”

“…A Schiff base is a kind of compound with an imine (−C=N) structure formed by the reaction of active carbonyl and amino compounds in the molecule and can form stable complexes with transition metal elements. , Schiff base compounds and their metal complex compounds have wide applications in medicine, catalysis, and analytical chemistry. − Schiff bases, especially some aromatic Schiff bases, tend to form stable complexes with copper due to the presence of −C=N double bonds and −OH group of the aromatic ring . Currently, increasing composite base on Schiff base molecules has been obtained for selective removal of trace heavy ion pollutants. , …”