Thorium Ions Research Articles

Fabrication of eggshell derived hydroxyapatite polymer composite membrane for efficient removal of thorium ions from aqueous solutions

Abstract A novel eggshell-derived hydroxyapatite polymer composite membrane was fabricated to explore its efficiency in the elimination of Th(IV) metal ions from water bodies. Membrane fabrication was carried out by two stage process in which, at first hydroxyapatite (Hap) was derived from eggshell and the minerals thus obtained were used as filler in Poly vinyl alcohol (PVA) - Poly vinyl pyrrolidone (PVP) based polymer membrane. Structural and morphological studies of PVA-PVP-Hap membrane were carried out by analyzing Fourier transform IR spectra (FTIR), X–Ray diffraction spectra (XRD), Scanning electron microscope-energy dispersive X-ray images (SEM-EDX) etc. Water uptake capacity and ion exchange capacity were determined for membrane characterization. Optimization studies were performed for the elimination of Th(IV) metal from polluted water. Regeneration studies also proved that the membrane can be used upto 4 cycles of operation with less than 5% loss in performance using ethanol as eluent for the desorption of this pollutant from the membrane.

Highly effective and selective adsorption of thorium(Ⅳ) from aqueous solution using mesoporous graphite carbon nitride prepared by sol–gel template method

Selective separation of thorium resources from aqueous solutions is an ideal strategy for recovering or removing radioactive ions, as well as reducing potential human health and environmental risks. In this study, an effective adsorbent, mesoporous graphite carbon nitride (mpg-C3N4), was synthesized by a simple thermal condensation using a sacrificial LUDOX HS-40 colloidal silica as template and applied to the selective adsorption of thorium ions from the multi-ion solutions. The results of competitive experiments illustrated that mpg-C3N4/r exhibited higher selectivity and efficiency for Th(IV) over other 14 co-existing cations, with the maximum selective adsorption capacities of Th(IV) reaching to 108.18 mg g−1 for mpg-C3N4/r=1.0 which is more than g-C3N4 (36.64 mg g−1) at pH 4.0. The interaction of Th(IV) with mpg-C3N4/r=1.0 and g-C3N4 were performed using batch processing, the adsorption isotherm was well conformed to the Langmuir adsorption model, and the maximum adsorption capacity of thorium at pH 4.0 and 298 K was calculated to be 196.08 mg g−1 which is more than three times of g-C3N4 (60.60 mg g−1). Also, the results of adsorption experiments on monazite leachate showed that mpg-C3N4/r=1.0 can be successfully used as an attractive adsorbent with the high adsorption efficiency (93.53%) of thorium. This work could broaden insights into the tailored design and synthesis of mesoporous adsorbents for the selective adsorption of thorium in multi-ion solutions.

Cumulative loading of the ion trap by laser ablation of thorium target in buffer gas

We describe a method that allows accumulation in a Paul trap of a large number of ions obtained from multiple laser ablation pulses, and therefore solving the problem of a single pulse that usualy gives rise to final trapping of too few ions. The proposed method of the cumulative trap loading was based on interaction with a buffer gas that provided a friction force. The method was applied to triply charged thorium ions and trapped a total of 106 ions. Numerical analysis of the ion motion allowed the experimental parameters to be optimized for the most effective implementation of the technique.

Highly efficient capture of Th(IV) from aqueous solutions using GO/TiO2 nanocomposite

An adsorbent GO/TiO2 nanocomposite has been synthesized and characterized. FTIR, XRD, TGA, TEM, SEM and EDX were used to characterize the prepared composite. In a batch method, the adsorption properties of the prepared composite against thorium ions were examined. Th(IV) adsorption kinetics study on GO/TiO2 suggests that the adsorption equilibrium attained within 240 min and depends on the pH value. The adsorption results were expressed mathematically by using Langmuir and Freundlich sorption models. The nanocomposite showed the highest Th(IV) adsorption of 292.32 mg/g at pH 2.5 and 25 oC. The thermodynamic results indicated a thermodynamically favorable, random and exothermic nature of the adsorption process. The obtained results demonstrate that GO/TiO2 nanocomposite can be regarded as a fast, effective and convenient water-based adsorbent for adsorption of Th(IV). This study suggests that nanocomposite can be a promising candidate for the removal of Th(IV) from aqueous solution.

Adsorption modeling and optimization of thorium (IV) ion from aqueous solution using chitosan/TiO2 nanocomposite: Application of artificial neural network and genetic algorithm

In this study, novel chitosan/TiO2 nanocomposite (Ch/Ti-ONC) synthesized and evaluated as an adsorbent for removing thorium (IV) (Th4+) ion from aqueous solution. The Ch/Ti-ONC was characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), Fourier Transform Infra-Red (FT-IR), and Scanning Electron Microscopy (SEM) and the specific surface area of Ch/Ti-ONC was found to be 28.11 m2 g−1. Artificial Neural Network (ANN) was employed to model the time diversity of the Th4+ adsorption. Three operating condition parameters were considered, namely, adsorbent weight, contact time, and pH. Various ANN structures were built up, trained, validated, and tested using 144 experiments. Optimal ANN structure was specified matching three criteria: the mean absolute percentage error, normalized root mean squared error, and R. The prediction process inside the optimal ANN was derived in the form of simple and user-friendly mathematical formulas. Genetic algorithm (GA) was applied to determine the most practical Ch/Ti-ONC in the adsorption of Th4+. At a fixed exposure time, the optimization procedure was carried out utilizing a GA with the mathematical formulas' objective function from the optimal ANN model. The adsorption kinetics was well described by the pseudo-second-order equation when the Langmuir model better fit the adsorption isotherms. Ch/Ti-ONC's adsorption capacity was 455 mg g−1 composite, which leads to 99 % removal at 45 °C. Besides, the calculated thermodynamic parameters (i.e., standard enthalpy, entropy, and Gibbs free energy) indicates the spontaneous and endothermic nature of the adsorption process. Besides, the ultimate adsorption was received when adsorbent weight, contact time, and pH equaled to 200 mg L−1, 64 min, 6.5, respectively. The loaded Th4+ can be efficiently restored with HNO3, and the Ch/Ti-ONC could be utilized several times in the absence of a dramatic decline in its adsorption capability.

Application of polyaniline nanocomposites in the trapping of thorium ions from aqueous solutions:Adsorption equilibrium, kinetics and thermodynamics

In this study, the adsorption behavior of Th(IV) ions was investigated using polyaniline (PAni) nanocomposites. Nanocomposites were synthesized with two types of dopants (H3PO4 and H2SO4) and two oxidants ((NH4)2S2O8 and KIO3) in the presence of two different surfactants (sodium dodecylbenzene sulfonate (SDBS) and hydroxypropyl cellulose (HPC)). The structure of the synthesized polymers was examined using FT-IR and SEM analyses. Adsorption of Th(IV) ions onto the synthesized polymers with a supreme removal (99.98%) was obtained by the H3PO4-doped polymers, especially for the sample with KIO3 oxidant and SDBS surfactant (PAni-2-1-S). BET, TGA and DSC analyses were also employed for the adsorbent characterization. The effect of main parameters was also investigated for the removal of Th(IV) ions from aqueous solutions by PAni-2-1-S. The pseudo-second-order kinetic and Langmuir isotherm models were in full agreement with the kinetic and isotherm experimental data, respectively and the highest adsorption capacity of the PAni-2-1-S was observed to be 68.49 mg/g. Thermodynamic data demonstrated the spontaneous and endothermic behavior of this adsorption process.

Gas cell studies of thorium using filament dispensers at IGISOL

Filament-based dispensers of thorium have been investigated at the IGISOL facility, Jyväskylä, for potential use as a thorium ion source for future collinear laser spectroscopy experiments. Several different filaments were manufactured in the Institute of Atomic and Subatomic Physics of TU Wien, with 232Th and 229Th prepared on tantalum substrates either by drying thorium nitrate solution or via molecular plating, while adding a layer of zirconium for oxide reduction. The filaments were characterized in a helium-filled gas cell by performing selective and efficient in-gas-cell resonance laser ionization and by analyzing the resulting ion beams by mass spectrometry. Additionally, the in-gas-cell laser ionization process of thorium was further characterized by wavelength scans, saturation measurements and by recording the temporal behavior of extracted ion pulses. Although an ion source was successfully created with mass-separated intensities over 106 ions/s, the required high filament temperature resulted in significant contributions from interfering impurities and deterioration of the filament structure.

Date seed as an efficient, eco-friendly, and cost-effective bio-adsorbent for removal of thorium ions from acidic solutions

Removal of thorium ions from acidic media using high effective bio-adsorbent is a very convenient viewpoint for the management of environmental pollutants. With this respect, this study is aimed to synthesize bio-adsorbent derived from date palm seed (DS bio-adsorbent) for adsorption of Th(IV) from acidic media. The studied bio-adsorbent was characterized by FTIR, SEM, and XRD techniques. The effective experimental parameters on the adsorption performance such as pH, bio-adsorbent dose, contact time, solution temperature, thorium initial concentration, and interfering ions were investigated. Furthermore, adsorption isotherm and kinetic studies were explored to describe the mechanism of thorium adsorption using the proposed bio-adsorbent. The Langmuir model result showed that the DS removal adsorption capacity was 43 mg.g-1 at optimized batch conditions. The kinetic findings indicated that the adsorption mechanism was in an agreement with the pseudo-second-order model. Additionally, the regeneration of the spent bio-adsorbent was studied using 0.3 mol.L-1 HNO3 as an eluent agent. This research suggested that the date palm seed bio-adsorbent could be evaluated as a beneficial adsorbent for the adsorption of thorium from aquatic and acidic media due to its selectivity and capacity.

Thorium(IV) Preconcentration by Chelate-Forming Adsorbents Based on a Maleic Anhydride–Styrene Copolymer

The adsorption and complexing properties of modified adsorbents based on a maleic anhydride–styrene copolymer with respect to thorium(IV) ions were studied. Adsorbents containing fragments of 2‑amino-4-chloro-6-sulfophenol and 2,4-diamino-6-phenyltriazine-1,3,5 are used. The main quantitative characteristics of the adsorption of thorium are determined, and the optimal adsorption conditions are found. The concentration factor is not lower than 200 in extraction from 20 mL of a solution by 30 mg of the adsorbent. The recovery of radioactive thorium exceeds 95%. The developed procedure was applied to determine thorium(IV) in soil contaminated with oil.

Activated carbon from wood wastes for the removal of uranium and thorium ions through modification with mineral acid

To prepare a highly efficient AC for removal of U(VI) and Th(IV) ions from water media, explosive property of NH4Cl was primarily recruited to exploit the sycamore wood (SW) wastes for production of an activated carbon (SWAC; AC) with highly ordered channels and high surface area, which was subsequently modified by treating with different mineral acid solution under microwave irradiation. After magnetization of acid-treated AC samples for easy separation from aqueous solution, the magnetized acid-treated AC (M-AcidAC) samples were examined to find the best conditions of both the activation process (NH4Cl/wood waste ratio, activation time and temperature) and acid treatment stage (acid normality, treatment time, and microwave intensity), using Taguchi experimental design and artificial neural network (ANN) analysis. The results disclosed that, among the mineral acids tested, HNO3 was superior for using in the treatment stage, since magnetized HNO3-treated AC (M-HNAC) showed higher sorption capacities towards the studied radionuclides. In addition, comprehensive study of sorption properties of M-HNAC towards U(VI) and Th(IV) ions vouchsafed that, using HNO3, inflicting an acid treatment stage on the SWAC is a beneficial path for preparation of a highly efficient sorbent for these radionuclides.

Synthesis, characterization and evaluation of carbon nanofiber modified-polymer for ultra-removal of thorium ions from aquatic media

Removal of thorium ions from aquatic media using high effective adsorbents is a very convenient viewpoint for the management of environmental pollutants. With this respect, this study is aimed to facile synthesize carbon nanofiber modified-(ethylene triamine- trimesoyl chloride) polymer (CNF-ETA-TMC) as a novel material for ultra-adsorption of thorium (Th(IV)) from aquatic media. The prepared CNF-ETA-TMC composite polymer adsorbent was characterized by FTIR and SEM/EDX techniques. The effective experimental parameters on the adsorption performance were optimized with factorial design analysis. The Langmuir modeling results showed that the CNF-ETA-TMC ultra-removal adsorption capacity of 867.9 mg g−1 at optimized batch conditions; pH 5, 30 min contact time, and 20 °C. Thermodynamic evaluations exhibited that the ΔG° function was decreased from -18.96 to -14.84 kJ/mol as the ΔH° parameter was calculated as -47.88 kJ.mol−1, confirming the spontaneous and exothermic nature of Th(IV) adsorption with increasing temperature from 303 to 333 K. The kinetic findings indicated that the adsorption mechanism was in an agreement with the pseudo-second-order model. Additionally, the regeneration performance of the adsorbent was increased in the range of 55-98% using HCl solvent at different concentrations, 0.25–1.0 mol.L−1. The cycling results that the composite polymer adsorbent revealed about 80% regeneration performance after five replications while the adsorption/desorption efficiencies decreased to 20/25% after 10th cycle. This research suggested that the synthesized CNF-ETA-TMC could be evaluated as a beneficial adsorbent for the infiltration of thorium from aquatic media due to its ultra-removal capacity.

Studies of thorium and ytterbium ion trap loading from laser ablation for gravity monitoring with nuclear clocks

Compact and robust ion traps for thorium are enabling technology for the next generation of atomic clocks based on a low-energy isomeric transition in the thorium-229 nucleus. We aim at a laser ablation loading of single triply ionized thorium in a radio-frequency electromagnetic linear Paul trap. Detection of ions is based on a modified mass spectrometer and a channeltron with single-ion sensitivity. In this study, we successfully created and detected 232Th+ and 232Th2+ ions from plasma plumes, studied their yield evolution, and compared the loading to a quadrupole ion trap with Yb. We explore the feasibility of laser ablation loading for future low-cost 229Th3+ trapping. The thorium ablation yield shows a strong depletion, suggesting that we have ablated oxide layers from the surface and the ions were a result of the plasma plume evolution and collisions. Our results are in good agreement with similar experiments for other elements and their oxides.

Isotope Shifts of Energy Levels in Helium-Like Highly Charged Ions

Isotope shifts of $$n = 1$$ and $$n = 2$$ levels and corresponding transitions in helium-like highly charged ions are calculated with high precision. The total value of the isotope shift is determined mainly by the sum of the field and mass shifts. The field shift is calculated by using the Dirac–Fock–Sturm method taking into account interaction of configurations. Quantum-electrodynamic corrections to this contribution are taken into account approximately by using the corresponding one-electron expressions. The mass shift is calculated both within the framework of the Breit approximation and by taking into account quantum-electrodynamic contributions that become substantial for heavy ions. In the case of thorium and uranium ions, corrections due to nuclear polarization and deformation are taken into account additionally.

Potential application of graphene oxide membranes in high-level liquid waste treatment

The drawbacks of current high-level liquid waste (HLLW) separation processes would bring some adverse effects on the sustainable and clean utilization of nuclear power. In this work, a novel separation method for HLLW treatment based on graphene oxide membranes (GOMs) was investigated. Effects of nitric acid concentration and membrane thickness on the permeation behaviors of typical ions through GOMs were systematically investigated. On the whole, the permeation rates were in the order: hydrogen ion, cesium ion > sodium ion > strontium ion > europium ion, uranyl ion > thorium ion, which could be well explained by size exclusion and chemical interaction. As the nitric acid concentration decreased, strong coordination cations were generally restrained from migrating through GOMs due to cations hydrolysis and deprotonation of graphene oxide sheets. Ions permeation was supposed to be a two-step process which included entrance to the membrane and intramembrane migration. Based on the favorable rejection of f-block elements, GOMs separation showed promising potential in HLLW treatment. Furthermore, a new technical route for HLLW separation was proposed which showed superiority of simplified process, low running cost, less secondary radioactive waste production.

Removal of Thorium from industrial waste via electrosorption technique

Activated carbon electrode has been tested as a potential sorbent for removal of Th ions from the actual wastewater sampel by electrosorption technique. The objective of this research is to investigate the performance of activated carbon electrode for remediation of real thorium sample. Adsorption of thorium ion by activated carbon electrodes was investigated with contact time up to 180 minutes by using positive potential at 0.2V (vs. Ag/AgCl), 0.4V (vs. Ag/AgCl) and 0.6v (vs. Ag/AgCl). Result shows that the condition has the highest percentage of thorium ion removal is at 0.6V (vs. Ag/AgCl) with highest specific capacity at 0.5 mg Th/g Carbon. Based on this research, the removal of thorium through electrosorption technique has the tendency to remove thorium ion and parameter such as contact time of electrosorption and voltage applied should be studied in more depth, where the removal of thorium is expected to increase.

Separation of Thorium Ions Using Synthesized Zeolite–Phosphate Composite from Sulfate Solution

Zeolite modified with phosphate (Z/P) was synthesized and tested for Th4+ adsorption. The optimum adsorption conditions are as follows: pH 3.5, contact time of 30 min, 0.1 g of Z/P, initial Th4+ concentration of 400 mg/L, 20% tributyl phosphate (TBP) in toluene as solvent, and room temperature. Kinetics and equilibrium parameters of the Th4+ adsorption onto Z/P were determined. The maximum sorption capacity determined using the Langmuir model reached 92.59 mg/g. The Th4+ adsorption onto Z/P follows a pseudo-second-order kinetic model. Th4+ can be efficiently desorbed from the loaded Z/P with 1 M HNO3 solution. The optimized conditions were applied to the thorium adsorption from a conglomerate sandstone sample of Abu El Toyour, eastern side of Wadi El Sahu, Southwestern Sinai, Egypt.

Distribution of uranium and thorium chains radionuclides in different fractions of phosphogypsum grains

This work presents results obtained using gamma spectrometry measurements of phosphogypsum samples on a non-fractionated (native) and fractionated phosphogypsum byproduct. The phosphogypsum was divided into particles size fractions within the range of < 0.063, 0.063–0.090, 0.090–0.125, 0.125–0.250, and over 0.250 mm and analyzed after reaching radioactive equilibrium using high-resolution gamma spectrometry technique. It was found that there is no significant differentiation between 226Ra distribution among particular grain size fractions of this material; however, tendency for preferential retention of radionuclides in particular grain size fractions is observed. The detailed analysis of results revealed that radium is preferentially retained in smaller grain size fractions, whereas lead and thorium in coarse fractions. The results indicate that overall 226Ra activity concentrations between particular fractions of phosphogypsum vary globally between − 34 and + 47% regarding non-fractionated material, and for 210Pb activity concentration, fluctuations are found between − 26 up and + 38%. Presumably, the mechanism of radium incorporation into gypsum phase is based on a sequence of radium bearing sulfate phases formation followed by a surface adsorption of these phases on the calcium sulfate crystals, whereas for lead and thorium ions, rather incorporation into crystal lattice should be expected as more likelihood process.

Lynas selects Kalgoorlie for rare earths processing plant

In this present study, thorium ion [Th(SO4)32-] was removed from aqueous sulphate medium using fabricated activated carbon-based electrodes (CBE). The thermal cross-linking technique was used to synthesize the CBE. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) technique, X-ray photoelectron spectroscopy (XPS) and field emission scanning electron microscopy (FESEM) were used to characterize the CBE adsorbent. The adsorptive characteristics were investigated through batch static adsorption experiments by varying the concentration, time and applied voltage. The adsorption statistics were justified by isotherm and kinetic models. The Langmuir and Freundlich adsorption model was revealed to be fitted, with a maximum adsorption capacity of 8.4 mg-Th/ g-Carbon. The electrosorption of [Th(SO4)32-] onto the CBE followed the pseudo-first and second-order kinetic rate models. Through FESEM, XRD and XPS characterization studies, a suitable mechanism for thorium sorption has been postulated.

Performance of poly sulfonamide/nano-silica composite for adsorption of thorium ions from sulfate solution

A new composite of poly sulfonamide/nano-silica composite (PSA/silica) was synthesized from the polymerization of sulfonamide in the presence of the prepared nano-silica. The prepared nano-silica, poly sulphonamide (PSA), and PSA/silica composites were utilized for Th(IV) adsorption from sulfate solution. These composites described by XRD, surface area analysis, SEM–EDX, and FT-IR techniques. The influence parameters on the Th(IV) adsorption were pH solution, ionic strength, contact time, adsorbent dose, Th(IV) concentration, and temperature besides the coexisting ions. At best parameters (pH4, 0.1 g adsorbent amount, and 45 min contact time), 200 mg/L Th(IV) ions were quantitatively adsorbed from 100 mL solution. The maximum uptake capacities of the nano-silica, PSA, and PSA/silica composites attained 122, 75, and 197 mg/g at 298 K. From the kinetic and equilibrium data were found to the adsorption processes of three composites fitted well with kinetic model of pseudo-second-order and Langmuir adsorption isotherm model. Thermodynamic studies resulted that negative values for ∆H° indicated an exothermic while positive values ∆S° showed random behavior for Th(IV) adsorption, while negative values of ∆G° indicated spontaneous Th(IV) adsorption. The maximum Th(IV) desorption from the loaded adsorbents performed by 0.1 M/L HCl.

Development of a recoil ion source providing slow Th ions including 229(m)Th in a broad charge state distribution

Ions of the isomer 229mTh are a topic of high interest for the construction of a “nuclear clock” and in the field of fundamental physics for testing symmetries of nature. They can be efficiently captured in Paul traps which are ideal for performing high precision quantum logic spectroscopy. Trapping and identification of long-lived 232Th+ ions from a laser ablation source was already demonstrated by the TACTICa collaboration on Trapping And Cooling of Thorium Ions with Calcium. The 229mTh is most easily accessible as α-decay daughter of the decay of 233U. We report on the development of a source for slow Th ions, including 229mTh for the TACTICa experiment. The 229mTh source is currently under construction and comprises a 233U monolayer, from which 229mTh ions recoil. These are decelerated in an electric field. Conservation of the full initial charge state distribution of the 229mTh recoil ions is one of the unique features of this source. We present ion-flight simulations for our adopted layout and give a final source design. This source will provide Th ions in their original charge state at energies suitable for capture in a linear Paul trap for spectroscopy investigations.