Selective removal of lanthanides from natural waters, acidic streams and dialysate

Abstract

The increased demand for the lanthanides in commercial products result in increased production of lanthanide containing ores, which increases public exposure to the lanthanides, both from various commercial products and from production wastes/effluents. This work investigates lanthanide (La, Ce, Pr, Nd, Eu, Gd and Lu) binding properties of self-assembled monolayers on mesoporous silica supports (SAMMS™), that were functionalized with diphosphonic acid (DiPhos), acetamide phosphonic acid (AcPhos), propionamide phosphonic acid (Prop-Phos), and 1-hydroxy-2-pyridinone (1,2-HOPO), from natural waters (river, ground and sea waters), acid solutions (to mimic certain industrial process streams), and dialysate. The affinity, capacity, and kinetics of the lanthanide sorption, as well as regenerability of SAMMS materials were investigated. Going from the acid side over to the alkaline side, the AcPhos-and DiPhos-SAMMS maintain their outstanding affinity for lanthanides, which enable the use of the materials in the systems where the pH may fluctuate. In acid solutions, Prop-Phos-and 1,2-HOPO-SAMMS have differing affinity along the lanthanide series, suggesting their use in chromatographic lanthanide separation. Over 95% of 100 µg/L of Gd in dialysate was removed by the Prop-Phos-SAMMS after 1 min and 99% over 10 min. SAMMS can be regenerated with an acid wash (0.5 M HCl) without losing the binding properties. Thus, they have a great potential to be used as in large-scale treatment of lanthanides, lanthanide separation prior to analytical instruments, and in sorbent dialyzers for treatment of acute lanthanide poisoning.

Selective and fast recovery of neodymium from seawater by magnetic iron oxide Fe3O4

“…Rare earth elements (REEs), including Lanthanide elements as well as yttrium and scandium, are widely used in various high-tech applications, such as high strength permanent magnets, automotive catalytic converters, lasers, electronic devices, and superconductors [1][2][3][4][5][6]. As a member of the rare earth family, neodymium (Nd) gains great attention due to high demand in the Nd-Fe-B magnet industry, especially in high performance electric motors in hybrid electric vehicles and direct-drive wind turbine generators [7].…”

Mesoporous Transition Metal Oxide Ceramics

“…Sportsman et al found that dodecanethiol functionalization of mesoporous Poretics membranes showed effective removal of many actinide species (Cs, Sr, Am and Pu), estimating around 70-80 % removal in acidic (HNO 3 ) solution [156]. Recently, Yantasee et al functionalized mesoporous silicas with diphosphonic acid (DiPhos), acetamide phosphonic acid (AcPhos), propionamide phosphonic acid (Prop-Phos), and 1-hydroxy-2-pyridinone (1,2-HOPO) for the selective removal of a number of lanthanides (La, Ce, Pr, Nd, Eu, Gd, and Lu) from both natural waters and acidic aqueous solution and found that over 95 % of 100 g/L of Gd in dialysate was removed by the Prop-Phos mesoporous silica after 1 min and 99 % in 10 min [157]. These particular functionalized mesoporous materials could also be regenerated with a 0.5 M HCl wash without losing the binding properties.…”

Rare Elements Electrochemistry: The Development of a Novel Electrochemical Sensor for the Rapid Detection of Europium in Environmental Samples Using Gold Electrode Modified with 2-pyridinol-1-oxide

“…In lanthanide atoms, the configuration of the valence electrons of the outermost shell is the same for all the species while the 4f orbitals are progressively filled with increasing atomic number. 2 Screening of the 4f orbitals leads to the extremely similar physical and chemical properties. [1][2][3][4] The structure of the 2-pyridinol-1-oxide (2-PO) and the predicted lanthanide complex is depicted in Scheme 1.…”