Adsorption Of Rare-earth Metals Research Articles

Study on the adsorption performance of La(III) and Y(III) on malic acid-kaolinite nanocomposite

• • Malic acid-kaolinite nanocomposite was obtained by intercalation-expansion method. • • Malic acid was inserted into the kaolinite layers and generated gas to expand kaolinite. • • The adsorption capacities of La(III) and Y(III) were as high as 128.5 mg/g and 145.2 mg/g respectively. • • Pseudo-second-order kinetics and Langmuir model fitted the adsorption kinetics and isotherm well. This paper reported an innovative method for the preparation of kaolinite nanocomposites and the application in the adsorption of rare earth metals (REEs). This method firstly inserted malic acid into the kaolinite layers, then the malic acid-kaolinite intercalation complex was calcined with Na 2 CO 3 and malic acid at a high temperature. The power provided by the neutralization reaction promoted malic acid between the kaolinite layers to decompose thermally, and finally obtained the malic acid-kaolinite nanocomposite (EKMA). This method overcame the problem of kaolinite with low adsorption efficiency, which was owing to strong hydrogen bonding between kaolinite layers. The specific surface area of EKMA was significantly increased, and the adsorption capacity for La(III) and Y(III) were as high as 128.5 mg/g and 145.2 mg/g respectively. The pseudo-second-order model and Langmuir model fitted the adsorption kinetics and isotherm well. Therefore, EKMA was expected to be applied in the treatment of REEs waste in industrial wastewater.

Sustainable composite material based on glutenin biopolymeric-clay for efficient separation of rare earth elements

Rare earth metals (REEs) are crucial for modern industries and technological development. Their extraction from non-renewable primary sources has almost reached its threshold due to excessive global demand. An effectual approach for REEs recovery is recycling secondary sources governed by separation materials. In this work, a novel glutenin-based Na-bentonite (Gle@Na_Bex:y) composite was produced via the in-situ hydrothermal route followed by a subsequent freeze-drying process. Additionally, a possible production route for the composites was proposed. The novel Gle@Na_Bex:y composites were characterized with Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET) surface area, and zeta potential (ZP) measurements. FTIR results complemented with SEM images and XRD measurements confirmed the successful incorporation of glutenin into the Na-bentonite clay. The separation of REEs from aqueous solution was used as a model system to demonstrate the material’s ability for selective metal recovery. The best conditions (T, pH, time) for REE sorption were assessed using equilibrium batch adsorption experiments. The kinetics of REE adsorption were effectively explained by a pseudo-second-order model; all the adsorption equilibrium data followed the Langmuir model. Thermodynamic investigations revealed that the adsorption is endothermic and spontaneous, and the adsorption of REEs occurred through a chemisorption process. The sorption mechanism of REE ions was investigated using molecular modelling. The results of this study demonstrate the feasibility of utilizing Gle@Na_Be50:50 composite as an efficient material for REEs removal. The maximum adsorption capacities of Y3+, La3+, and Nd3+ achieved with Gle@Na_Be50:50, were 76.87, 56.71, and 74.61 mg/g, respectively. This work offers a new route for engineering, valuable composite materials for the separation of REEs from diverse sources.

Kenaf cellulose-based poly(amidoxime) ligand for adsorption of rare earth ions

A well-known adsorbent, poly(amidoxime) ligand, was prepared from polyacrylonitrile (PAN) grafted kenaf cellulose, and subsequent characterization was performed by Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FESEM) and inductively coupled plasma mass spectrometry (ICP-MS). The adsorption capacities of the prepared ligand for rare earth metals are found to be excellent, with adsorptions of La3+, Ce3+, Pr3+, Gd3+ and Nd3+ experimentally determined to be 262, 255, 244, 241 and 233 mg·g−1, respectively, at pH 6. The experimental values of the adsorption of rare earth metals are well matched with the pseudo-second-order rate equation. The reusability of the adsorbent is examined for seven cycles of sorption/desorption, demonstrating that the proposed adsorbent could be reused for over seven cycles without any significant loss in the original removal capability of the ligand.

Rare Earth Elements Removal from Water Using Natural Polymers

Adsorption of rare earth metals, Eu (III) and Nd (III) was investigated on a new environmental friendly material, thiourea functionalized cellulose. Before usage, the synthesized material was characterized by Fourrier Transform Infrared spectroscopy and energy dispersive X-ray analysis. The influence of adsorption parameters (adsorbent dosage, time, temperature and initial metal concentration) on adsorption capacity was investigated. Experimental data were fitted by using the pseudo-first-order and pseudo-second-order kinetic models. Simultaneously thermodynamic and equilibrium studies have been carried out using Langmuir, Freundlich and Sips isotherm. Maximum adsorption capacities were reached in 30 minutes at 298 K having the value of 27 mg/g for Eu (III) and 73 mg/g for Nd (III).

Adsorption of rare earth metals from water using a kenaf cellulose-based poly(hydroxamic acid) ligand

A kenaf cellulose-based poly(hydroxamic acid) ligand was synthesized from poly(methylacrylate) grafted cellulose and applied towards the adsorption of rare earth metals from aqueous media. The starting materials and final product were examined by FT-IR, FE-SEM, and ICP-MS. Remarkable maximum adsorption results were obtained for the earth metals La3+, Ce3+, Pr3+, Gd3+, Nd3+, Eu3+, and Sm3+, with values of 260, 245, 235, 220, 210, 195, and 192mgg−1, respectively. The adsorption capacities of the ligand for adsorption of rare earth metals were well fitted with the pseudo-second-order rate equation. Further, the adsorption properties of the rare earth ions were nicely matched with the Langmuir isotherm model, (R2>0.99), thus suggesting that the adsorbent surface of the ligand is monolayer and homogenous in nature. The reusability of the created ligand was evaluated by carrying out sequential sorption/desorption experiments, indicating that the developed adsorbent can be reused for at least 10cycles without incurring any significant losses to its primary removal capabilities.

Adsorption of rare earth metals (Sr2+ and La3+) from aqueous solution by Mg-aminoclay–humic acid [MgAC–HA] complexes in batch mode

The recoveries of Sr2+ and La3+ as rare earth metals (REMs) were studied using Mg-aminoclay–humic acid [MgAC–HA] complexes prepared by self-assembled precipitation, i.e., [HA] intercalation into layered [MgAC].

Environmental nano-pollutants (ENP) and micro-interfacial processes

The concepts of nano-science and technology are penetrating into the aspects of environmental science and technology. Environmental nano-pollutants (ENP) is suggested. as a specific category of pollutants that presents many common critical characters impacting the natural and social ecosystems. The outstanding properties are the various reactions in the macro-interfacial processes. Several examples as the adsorption of rare-earth metals on Chinese loess, the adsorption of PAHs on aquatic sediments with humic substances and the speciation of nano-flocculants in the water and wastewater treatment are discussed in the paper.

Synthesis and Study of Ion Adsorption and Fluorescent Properties of Silica-Grafted Bis(crownazo)methine

A ketocyanine ligand containing two N-aza-15-crown-5 residues has been synthesized and covalently anchored to a silica substrate through an azomethine link. The ligand formation and molecular structure have been determined by combining spectral data and molecular simulations. Preferential adsorption of rare-earth metals from aqueous solutions to the modified surface has been noticed. In the case of lanthanum, the adsorption is accompanied by significant fluorescence enhancement, which allows this system to be used as a sensor for La3+ ion.

Adsorption of rare-earth metals (Tb,Dy,Er) on a Mo(110) surface

The adsorption of Tb, Dy and Er on a Mo(110) surface has been studied by means of AES, LEED, work function change measurements and quartz microbalance technique with the aim of understanding the evolution of the structure, structure-related properties and growth mode as a function of the adatom concentration, the adsorbate and the temperature. Although many similarities are found within investigated adsorbates some differences in details have been observed. The irreversible changes in work functions, submonolayer film structures and film growth modes, and a considerable decrease of the initial dipole moments of the adatoms observed at elevated substrate temperature, are probably determined by the change of the electronic states of the adsystems. The relation between the at present investigated initial dipole moments of RE atoms adsorbed on a Mo(110) surface and their electron structure is discussed.

Adsorption of rare-earth metals (Tb,Dy,Er) on a Mo(110) surface

Adsorption of rare-earth metals (Tb,Dy,Er) on a Mo(110) surface