Removal Of Lanthanum Research Articles

Lanthanum removal from spent catalysts of refinery applying electroremediation technique coupled to selective precipitation

Lanthanum removal from spent catalysts of refinery applying electroremediation technique coupled to selective precipitation

Removal of lanthanum and cerium from aqueous solution using chitosan-functionalized magnetite-pectin

The present study synthesized magnetite-pectin-chitosan (MPC), which is a nanocomposite adsorbent through partial reduction co-precipitation method. Its structure and morphology were characterized by Scanning Electron Spectroscopy (SEM), X-ray diffraction (XRD), Fourier Transform Infrared Spectrometry (FT-IR) and Vibrating Sample Magnetometry (VSM). One studied the adsorption of Lanthanum and Cerium ions onto MPC in a batch system as a function of initial pH of solution, contact time, initial concentration and temperature. When the initial pH of the solution increased, the La(III)/Ce(III) ions augmented as well. The optimum pH for La/Ce adsorption was 5 and the maximum adsorption achieved within 30 min. The thermodynamics parameters such as enthalpy (ΔH∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Delta {\ ext{H}}^\\circ$$\\end{document}), entropy (ΔS∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Delta {\ ext{S}}^\\circ$$\\end{document}) and Gibbs free energy changes (ΔG∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Delta {\ ext{G}}^\\circ$$\\end{document}) were calculated with the results suggesting that the adsorption was exothermic and spontaneous. To determine the adsorption characteristics, models of Langmuir, Dubinin-Radushkevich, Freundlich, Temkin and Flory–Huggins adsorption isotherms were performed. Langmuir isotherm model enabled the data of adsorption to be described very well. The adsorption capacity was seen to be 8.17 mg/g and 9.72 mg/g for lanthanum and cerium, respectively. The adsorption kinetics of MPC indicated that the adsorption process fit the Pseudosecond-order (PSO) model. Based on these data, it is concluded that short operating time, eco-friendly technology, and easy to apply MPC can be used for La(III)/Ce(III) ions removal.

Selective removal of lanthanum from monazite – (Nd) ores by pH-controlled mixed micelle cloud point extraction

A novel extraction method via cloud point extraction was used for the pH- selective separation of lanthanum ions from a number of real samples. The formation of a binary complex between La(III) with cetyltrimethyl ammonium bromide (CTAB) and Eriochrome cyanine R (ECR) is the main idea for the proposed study. The obtained complex could be extracted easily by Triton X-114 at 45 °C. The amount of La(III) was determined before and after separation process using an ICP-OES. The primary factors controlling the extraction of La3+ were extensively examined. To cause the clouding phenomenon and, achieve high extraction efficiency, KNO3 and CTAB must be present. The extraction efficiency was greater than 95% under ideal conditions for the concentrations strating from 0.09 to 60 µg mL−1 and a low detection limit (0.3 μg L- 1) with a preconcentration factor of 100. Moreover, by simply changing the pH of the aqueous phase, La(III) can be extracted with high selectivity from a variety of complicated matrices. The findings showed that at pH 3.5, La3+ completely extracted in the micellar phase but Nd(III) does not separate at all. These results demonstrate the reliability of the new method for selective separation of La(III).

Removal of lanthanum from residual catalyst of oil cracking through the application of electric potential

Removal of lanthanum from residual catalyst of oil cracking through the application of electric potential

Comparison of fluorine removal performance and mechanism of spheroidal magnesium oxide before and after lanthanum modification.

Firstly, spherical magnesium oxide was synthesized by simple magnesium salt and specific reaction conditions. Then, lanthanum-modified spherical magnesium oxide (LSMO) was prepared by impregnation of lanthanum salt. The adsorption mechanism of the adsorbent was investigated by XRD, SEM, XPS, and FT-IR. Through the study of fluorine removal performance, for the solution with fluoride ion concentration of 10mg·L-1, the fluorine removal efficiency of lanthanum-modified spherical magnesium oxide (15LSMO) (93.1%) with 15% impregnation mass ratio is higher than that of SMO (82.7%). In addition, in the pH range of 2-11 or in the presence of interfering ions, the fluoride removal effect of 15LSMO still meets the fluoride removal efficiency of more than 90%. The research enhanced the profound insights into the effect and mechanism of fluorine removal of lanthanum modified materials.

Removal of lanthanum, cerium and thorium metal ions from aqueous solution using ZrT hybrid ion exchanger

In this paper, a hybrid exchanger, zirconium triethylenetetramine (ZrT), of the class of tetravalent metal acid (TMA) salts, has been synthesized by the sol–gel method. In the present work, an attempt has been to investigate the sorption behavior of lanthanum, cerium, and thorium metal ions towards ZrT exchanger in various electrolytes media with different concentrations. In order to understand the uptake behavior of ZrT, parametric studies, kinetic and thermodynamic studies have been investigated. Distribution studies data revealed the feasibility of binary lanthanide separations using ZrT and show possibility of its promising use as an efficient ion exchanger in the treatment of water containing radioactive metal waste. In general, the decay storage or ion exchange treatment is used for the treatment of aqueous waste generated from the low nuclear power reactor. As per the report (IAEA-TECDOC-654, 1992), such nuclear aqueous waste generated is found acidic in view of used acidic chemicals during the process. The use of ZrT will be effective or in other words, ZrT can be a potential candidate to be used as an ion-exchange material for the treatment of such nuclear aqueous waste, after optimizing the process parameters, in particular maintaining the pH in the range of 4–5.

Lanthanum biosorption using sericin/alginate particles crosslinked by poly(vinyl alcohol): Kinetic, cation exchange, and desorption studies

Nowadays, lanthanum removal from wastewater has received attention due to its importance in various industrial applications. Biosorption has been considered a promising process for lanthanum removal from secondary sources. This study aimed to evaluate the use of sericin/alginate/poly(vinyl alcohol) (SAPVA) particles for lanthanum biosorption in batch system. The effect of pH on the biosorption of lanthanum showed that both lanthanum‐uptake (0.103 mol/kg) and calcium‐release (0.155 mol/kg) reach a maximum at equilibrium pH 5.22. Biosorption kinetics was carried in three lanthanum initial concentrations (0.0005, 0.0011, and 0.0017 mol/dm3). The results revealed that the equilibration time was reached between 210 and 450 min and biosorption capacity at equilibrium between 0.050 and 0.152 mol/kg. The kinetic followed the pseudo-second order model and the external diffusion was the main limiting step. Evaluation of cation exchange mechanism showed that the lanthanum biosorption is related to a stoichiometric reaction (2:3 ratio) between calcium and lanthanum. Calcium nitrate under acidic conditions was able to retrieve lanthanum biosorbed in the particles with high efficiency (96.07 ± 2.02%). Regeneration kinetics showed a longer equilibration time (630 min) and lower biosorption capacity at equilibrium (0.138 mol/kg) for the lanthanum initial concentration of 0.0015 mol/dm3. In this case, the experimental kinetic profile of calcium released throughout the lanthanum biosorption was not stoichiometric. Characterization analyzes suggest that the main mechanism involved in lanthanum capture and calcium release was cation exchange between functional groups on the biosorbent particles and lanthanum. Thus, SAPVA particles are a promising biosorbent for lanthanum removal from aqueous solutions.

Evaluation of strong anion exchange hyper-crosslinked resin for lanthanum removal

In this study, strong anion exchange hyper-crosslinked resin was used for the removal of rare earth element, lanthanum. Poly (styrene-co-EDGMA-co-VBC) is a resin that was synthesized and used in this research. The objective of this research is to study the pH stability and to evaluate the resin for lanthanum removal by using the Solid Phase Extraction (SPE) batch method where the influent of lanthanum solution will be loaded to the designed column containing resin. The pH stability test of resin was studied at different pH (pH 2-5). The evaluation of resin for resin loading (0.5, 1.0, and 1.5 g) and concentration of lanthanum (10, 30, and 50 ppm) were investigated. From the experiment, the resin is stable in acid solution since there is no change in the functional group. The morphology surface using Scanning Electron Microscope (SEM) shows a rough surface and beads attach on the resin without porous on the surface of resin except the resin at the condition of 50 ppm of with 1.0g resin. The resin that performed at 50 ppm with 1.0 g was successful remove lanthanum for 26.7 ppm based on ICP-MS analysis. As a conclusion, this resin can be used for removal of lanthanum.

Adsorptive removal of lanthanum based on hydrothermally synthesized iron oxide-titanium oxide nanoparticles.

Iron oxide-titanium oxide (Fe2O3-TiO2) nanoparticles were developed as an effective adsorbent in order to extract and remove lanthanum ions selectively from aqueous media. Fe2O3-TiO2 nanoparticles were prepared by simple hydrothermal method and structurally characterized using FESEM, EDS, XRD, FTIR, and BET techniques. The analytical potential of Fe2O3-TiO2 nanoparticles was interpreted by applying the kinetic and isotherm models. The maximum static uptake capacity was 89.63mgg- 1 at pH7. Adsorption isotherm data evinced that a monolayer adsorption occurred on a homogeneous adsorbent surface which is compatible with Langmuir isotherm model. Data acquired from kinetic models study proved that La (III) adsorption onto Fe2O3-TiO2 nanoparticles followed a pseudo-second-order kinetic equation. Thermodynamic study exhibited that a spontaneous process is favorable for adsorption mechanism of La (III) on Fe2O3-TiO2 nanoparticles. Moreover, the existence of different coexisting ions did not influence the extraction of La (III). Finally, the recommended methodology was applied on several environmental samples.

Recovery of Rare Earth Elements from Wastewater Towards a Circular Economy.

The use of rare earth elements is a growing trend in diverse industrial activities, leading to the need for eco-friendly approaches to their efficient recovery and reuse. The aim of this work is the development of an environmentally friendly and competitive technology for the recovery of those elements from wastewater. Kinetic and equilibria batch assays were performed with zeolite, with and without bacterial biofilm, to entrap rare earth ions from aqueous solution. Continuous assays were also performed in column setups. Over 90% removal of lanthanum and cerium was achieved using zeolite as sorbent, with and without biofilm, decreasing to 70% and 80%, respectively, when suspended Bacillus cereus was used. Desorption from the zeolite reached over 60%, regardless of the tested conditions. When in continuous flow in columns, the removal yield was similar for all of the rare earth elements tested. Lanthanum and cerium were the elements most easily removed by all tested sorbents when tested in single- or multi-solute solutions, in batch and column assays. Rare earth removal from wastewater in open setups is possible, as well as their recovery by desorption processes, allowing a continuous mode of operation.

Enhanced lanthanum adsorption by amine modified activated carbon

Rare earths are one of the most critical raw materials group. In an effort to develop an effective adsorbent for aqueous rare earths recovery, activated carbon (AC) was modified with pentaethylenehexamine. Both raw AC and modified activated carbon (MAC) were characterized by X-ray diffraction (XRD), FT-IR and surface area analyses. The set of experiments was carried out with lanthanum, selected as representing of rare earths family, and the impacts of reactive time and concentrations of lanthanum were evaluated. The aqueous lanthanum adsorptive kinetics and capacity were also determined. The strong improvement in the efficiency values detected by using modified carbons (uptake 100% until initial concentrations of about 2600 ppm and release over 95%) demonstrated that the coordination mechanism due to modifying agent is effective. MAC presented lower kinetics and more than double adsorptive capacity as compared with AC. Furthermore, the adsorbent can be used successfully at least four times after regeneration for the removal of lanthanum and seems to show a selective behaviour in equimolar solutions with copper as competitive ions.The overall results demonstrated the potential utility of modification for enhancement of performances of AC-based materials for rare earths removal from aqueous solutions.

Optimizing the lanthanum adsorption process onto chemically modified biomaterials using factorial and response surface design

The rare metals' potential to pollute air, water, soil, and especially groundwater has received lot of attention recently. One of the most common rare earth group elements, lanthanum, is used in many industrial branches, and due to its toxicity, it needs to be eliminated from all residual aqueous solutions. The goal of this study was to evaluate the control of the adsorption process for lanthanum removal from aqueous solutions, using cellulose, a known biomaterial with high adsorbent properties, cheap, and environment friendly. The cellulose was chemically modified by functionalization with sodium β-glycerophosphate. The experimental results obtained after factorial design indicate optimum adsorption parameters as pH 6, contact time 60 min, and temperature 298 K, when the equilibrium concentration of lanthanum was 250 mg L−1, and the experimental adsorption capacity obtained was 31.58 mg g−1. Further refinement of the optimization of the adsorption process by response surface design indicates that at pH 6 and the initial concentration of 256 mg L−1, the adsorption capacity has maximum values between 30.87 and 36.73 mg g−1.

Preparation and characterization of titanium tungstophosphate immobilized on mesoporous silica SBA-15 as a new inorganic composite ion exchanger for the removal of lanthanum from aqueous solution

In this study, a novel inorganic composite ion exchanger based on titanium tungstophosphate (TWP) and mesoporous silica SBA-15 has been synthesized. The synthesized product was characterized by methods and instrumental techniques. The results obtained from X-ray diffraction, N2 adsorption–desorption and Fourier transform infrared analysis confirm immobilization of TWP on SBA-15. Consequently, the ability of this composite for the adsorption of lanthanum ions from aqueous solution was investigated. Considering the relatively high adsorption capacity of lanthanum onto synthesized composite, this material can be potential candidate for the removal of even trace amount of lanthanum ions from nuclear and other industrial wastewater.

Preparation of nanostructured hydrated antimony oxide using a sol-gel process. Characterization and applications for sorption of La3+ and Sm3+ from aqueous solutions

The study focused mainly on the synthesis of nanosized hydrated antimony oxide as an ion exchange material via sol-gel process using water as a reagent to control the pH and to obtain a pure and dense hydrated antimony oxide. The obtained antimony oxide was characterized using X-ray diffractometer, scanning electron microscope, TG-DTA, and fourier transform infrared spectroscopy. The result showed the formation of stibiconite with a cubic crystal structure in nanometric range (9.54 nm). FTIR study confirmed the formation of antimony oxide with characteristic bands at about 766 and 552 cm–1 attributed to Sb–O streatching modes of Sb–O–Sb and Sb–OH, respectively. The synthesized hydrated antimony oxide demonstrated monofunctional ion-exchange characteristic and reasonably good chemical stability in acidic and basic media. The synthesized ion exchanger was then used for the removal of lanthanum(III) and samarium(III) from aqueous solutions. As can be seen from distribution studies the distribution coefficient K d increased with increasing the reaction temperatures of the solution. Adsorption experiments were carried out using both batch and column systems. The Langmuir, Freundlich, and Dubinin–Radushkevich (D–R) equilibrium models were used and a value q max was 41.10 and 48.42 mg g–1 for La(III) and Sm(III), respectively. Thermodynamic parameters, ΔH°, ΔG°, and ΔS° were calculated and indicated an endothermic and spontaneous process.

Response surface methodology for the optimization of lanthanum removal from an aqueous solution using a Fe3O4/chitosan nanocomposite

In the present work, magnetite nanoparticles/chitosan composites (Fe3O4/CS) were prepared by a chemical precipitation method. We demonstrated the efficient removal of a rare earth metal, lanthanum (La3+), from an aqueous solution using the composite. The removal of La3+ was optimized by using response surface methodology. Analysis of variance and Fisher's F-test were used to determine the reaction parameters which affect the removal of La3+. Optimal conditions, including adsorbent dosage, pH, temperature, and contact time for the removal of La3+, were found to be 6.5 mg, pH 11, 40 °C, and 50 min, respectively. The adsorption capacity was 99.88%. The rate of La3+ adsorption was significantly affected by the solution pH and adsorbent amount. An adsorption isotherm was fitted well by the Freundlich model with a linear regression correlation value of 0.9975. The adsorption of La3+ using the composite followed pseudo second-order kinetics. Thermodynamic studies have revealed that the negative values of Gibbs free energy confirmed the spontaneous and feasible nature of adsorption.

Computational removal of lanthanum–cerium bromide self-activity

It has been reported that detectors made of lanthanum–cerium halides, such as LaBr3(Ce) and CeBr3 have superior energy resolution for gamma-radiation detection compared to that offered by conventional sodium iodide [NaI(T1)] detectors. However, it has also been observed that the lanthanum–cerium halides contain certain amount of self-activity caused by the radioactive isotope 138La. Additionally, LaBr3(Ce) and CeBr3 crystals have also been reported to be affected by β-contamination in the low-energy and α-contamination in the high-energy regions. This paper presents a computational approach to reduce self-activity and contamination for LaBr3(Ce) and CeBr3 detectors using a third reference NaI(T1) detector. This procedure can be implemented as an automatic self-calibration module for gamma-radiation detectors made of LaBr3(Ce) and/or CeBr3 crystals.

An examination of the uptake of lanthanum from aqueous solution by crab shell particles

Removal of lanthanum (La) from aqueous solution by crab shell, Portunus sanguinolentus, was investigated. Based on the experimental results obtained at different pH conditions and La speciation, it was identified that the micro-precipitation of lanthanum carbonate (La 2(CO 3) 3) on the surface of crab shell is the main mechanism responsible for La removal by crab shell. The SEM images together with EDX analysis confirmed the presence of La on the surface of crab shell. Isotherm experiments at pH 5 revealed that the maximum biosorption potential of crab shell was 140.1 (mg La)/g, according to the Langmuir model. The La biosorption kinetics was very fast, and the kinetic data were successfully modeled using non-linear pseudo-first order model. Experiments at different ionic strength revealed that La biosorption capacity of crab shell was least affected even at high ionic strength of 0.214 M. Thus, crab shell was identified as a low-cost and potent biosorbent for the removal of La from liquid waste.

Low concentrations of tetrodotoxin interact with tetrodotoxin‐resistant voltage‐gated sodium channels

Tetrodotoxin (TTX) is used to distinguish between two classes of voltage-gated sodium channel (VGSC)--TTX sensitive (TTXS) and TTX resistant (TTXR). The resistance of TTXR VGSCs is thought to result from a low binding affinity of TTX, although at high TTX concentrations channel block does occur. Here, we show that, at concentrations below those which produce block, TTX can bind to TTXR VGSCs. Whole-cell voltage clamp recordings were made from dissociated rat dorsal root ganglion neurones that expressed both TTXS and TTXR sodium currents. Voltage-gated calcium currents were blocked by 10 microM extracellular lanthanum chloride. TTXS, but not TTXR, current was suppressed by using a holding potential of -50 mV, and the effect of TTX on the isolated TTXR current was explored. Extracellular application of 0.5 microM TTX produced a 40% increase in TTXR current amplitude, a negative shift in the voltage-dependence of current activation (approximately -8 mV) and inactivation (approximately -10 mV) and increased rates of current activation and inactivation. The effect of TTX on current amplitude was dose-dependent (EC50 = 364 nM). Removal of lanthanum prevented the effect of TTX on TTXR current amplitude, whereas reducing extracellular calcium did not. The findings are consistent with an interpretation that TTX relieves a tonic block of the TTXR VGSC by lanthanum. We conclude that TTX binds to the TTXR VGSC at low concentrations, without blocking it. This appears to be the first demonstration of a clear distinction between binding affinity and blocking potency of a channel-blocking agent.

Removal of lanthanum and gadolinium from nitrate medium using Aliquat-336 impregnated onto Amberlite XAD-4

Aliquat-336 in benzene was supported on Amberlite XAD-4 crosslinked polystyrene resin. The use of XAD-4 impregnated with Aliquat-336 resin for removal of lanthanum(III) and gadolinium(III) from nitrate medium was carried out using batch technique. Various parameters affecting the uptake of these metal ions such as contact time, metal ion concentrations, V/ m and pH value were separately studied. Effect of temperature on the equilibrium distribution values has been studied to evaluate the changes in standard thermodynamic quantities. A comparison of kinetic models applied to the adsorption rate data was evaluated for Lagergren first order, the pseudo second order and Morris–Weber kinetic models. From the results, both pseudo second order and intraparticle diffusion models were found to best correlate the experimental rate data. The capacity of the impregnated resin for both lanthanum(III) and gadolinium(III) was found to be 4.73 and 4.44 mg/g. From the results, impregnation of Aliquat-336 onto Amberlite XAD-4 provides an efficient impregnated resin for the removal of lanthanum(III) and gadolinium(III) from 0.1 M nitrate aqueous solution.

Effect of counterions on lanthanum biosorption by Sargassum polycystum

The effect of the presence of different anions on the biosorption of La 3+ (Lanthanum) using Sargassum polycystum Ca-loaded biomass was studied in this work. Different types of metal salts were used, such as nitrate, sulphate and chloride. The presence of the anion sulphate decreased the metal uptake for tested pH values of 3–5 when compared to the nitrate and chloride systems. The presence of chloride ions did not seem to interfere with the lanthanum removal. The speciation of lanthanum in solution could explain the differences obtained for the different systems and the Mineql+ program was used for the calculations. A monovalent complex with sulphate and lanthanum was formed that had lower apparent affinity towards the biomass compared to the free trivalent metal ion. The La uptake varied from 0.6 to 1.0 mmol g −1. The Langmuir model was used to describe quantitatively the sorption isotherms. The addition of sulphuric acid for pH adjustment decreased the metal uptake from lanthanum sulphate solutions when compared to the nitric acid addition. The effect was more pronounced with sulphuric acid due to the formation of complexes.