Tl Ions Research Articles

Simple solution and paper-based fluorescent aptasensors for toxic metal ions, thallium(l) and lead(ll).

Heavy metal ions, such as thallium(I) and lead(II) are environmental toxicants known to cause a severe threat to human and ecosystem health. This work investigates aptamers and intercalating chromophore-based complexes for the detection of these toxic species. In one method, a selective label-free "turn-on" biosensor was developed using a G-quadruplex-intercalating agent, berberine. Fluorescence, melting temperature (Tm), and circular dichroism analysis confirmed the affinity and selectivity results, illustrating the potential of these aptasensor methods for improving detection limits. These fluorescence assays were found to perform with a detection limit of 3.4 μM for Tl(I) and 0.84 nM for Pb(II). Furthermore, the assays were challenged successfully with Tl(I) and Pb(II) spiked into river water samples. We next developed paper-based fluorescent assays for Tl(I) and Pb(II), where the aptamer/berberine complex was spotted onto the paper test zone. When Tl(I) or Pb(II) ions solutions were spotted onto the top of the test zone and the spot was illuminated with a portable UV light (365 nm), a strong green fluorescence could be easily visualized with the naked eye. The lowest detection limits achieved with these fluorescent paper-based assays for Tl(I) and Pb(II) were 1.1 nM and 1.6 nM, respectively. The two fluorescent approaches presented here have the potential to be the basis of rapid, fast, and cost-efficient screening assays for these toxic species.

Harnessing the power of nonthermal Plasma: A breakthrough in stabilizing Thallium contaminants in soil and unveiling the mechanism

Thallium (Tl) is a highly toxic element and can accumulate in human body through food, water, or air and cause damage to multiple organs. In this study, the nonthermal plasma (NTP) was employed to irradiate the potassium dihydrogen phosphate (KH2PO4) and sodium diethyldithiocarbamate trihydrate (SDDC) to solve the issues brought by their poor stability and insufficient chelation capabilities in soils to intensify their performance on immobilizing monovalent Tl contaminants in soils. Both an orthogonal design (OD) and a central composite design (CCD) were adopted to arrange the multi-parametrical modification and stabilization experiments. The leaching toxicities ranging from 5.11 to 52.37 µg/L of Tl+ ions were obtained in the OD experiments. The changes in both NTP time and the molar ratios of KH2PO4 to SDDC had a significant effect on the activation procedure. The leaching concentration ranging from 0.37 to 7.34 µg/L was achieved in the CCD stabilization experiments. NTP activation and the rearrangement of the stabilization conditions both were beneficial to the transformation of physicochemical states of Tl pollutants in soils, which proved the existence of chemical immobilization brought by the irradiated stabilizers (NTP-PK-SDDCs) to the Tl contaminants. The stabilization process was targeted between only Tl contaminants and NTP-PK-SDDCs in soils. The NTP irradiation enhanced the physicochemical characteristics of stabilizers, further intensifying the immobilization of Tl species in the soils. The enhancement mechanism was attributed to the free radicals-induced doping, oxidation, and polycondensation and the bombards of electrons, which strengthened the electrostation and chemisorption of NTP-PK-SDDCs towards Tl ions. The potential impact of this study includes the development of more effective and sustainable remediation methods for Tl-contaminated soils, contributing to environmental protection and human health.

Mechanisms of inclusion of thallium-201 into Prussian blue nanoparticles for nuclear medicine applications.

Prussian blue is known for its high affinity for thallium and other univalent metal cations and has been used as a treatment for radiocaesium and thallium/radiothallium poisoning. While Prussian blue nanoparticles (PBNPs) show potential for binding radioactive thallium for further use in nuclear medicine applications, the inclusion mechanism remains elusive. Understanding the interaction between PBNPs and 201Tl is essential for identifying the physicochemical and radiochemical properties required for optimal in vivo performance. In this work, we evaluated the binding mechanism between Tl and PBNPs with different coatings and core shapes. Combining PBNPs with [201Tl] thallium(I) chloride provided high radiolabelling yields and radiochemical stabilities under physiological conditions. Comprehensive characterisation by different X-ray techniques confirmed that Tl ions are located in the interstitial sites within the crystal structure, maintaining the integrity of the iron (Fe) 4p electronic distribution and inducing local modifications in the nearby C-N ligands. Additionally, this inclusion does not impact the core or the shell of the nanoparticles but does alter their ionic composition. The PB ionic network undergoes significant changes, with a substantial drop in K+ content, confirming that Tl+ ions replace K+ and occupy additional spaces within the crystal structure. These results open new opportunities in nuclear medicine applications with 201Tl-PBNPs where the size, shape and composition of the particles can be specifically tuned depending on the desired biological properties without affecting the radiochemical performance as a vehicle for 201Tl.

Nonthermal plasma-activated polyvalent cerium-manganese bimetallic (hydro)oxide-functionalized nanographene for the removal of thallium(I) contaminants and mechanism exploration

Thallium(I) (Tl(I)) is a highly toxic substance with significant environmental toxicity, belonging to the high-toxicity category, with characteristics of chronic accumulation. In this study, cerium(IV) (Ce(IV)) was incorporated into nonthermal plasma (NTP)-irradiated polyvalent manganese (hydro)oxides and synchronously grafted onto nanographene to synthesize a new type of Mn-based adsorbent (NTP-P-Ce-Mn-NGs) with excellent adsorption capacities for Tl(I) contaminants, aiming to overcome the weak adsorption capacity of existing adsorbents for Tl(I) and propose a new approach to enhance their adsorption performance. The factors including the molar ratios of Ce(SO4)2 to MnCl2, the dosage of nanographene, and the irradiation time of NTP all significantly affected the synthesis of NTP-P-Ce-Mn-NGs. Both the participation of NTP and the intercalation of Ce(IV) exerted a potential influence on the adsorption improvement of Mn-based adsorbents towards Tl(l) contaminants. Different chemical valences of Ce and Mn species were observed in the synthesized adsorbent. More flocculated and amorphous fillings were generated in the adsorbent samples with both Mn and Ce, visually presenting the incorporation effect of Ce into the NTP-irradiated Mn (oxy)hydroxides. A maximum adsorption capacity of 352.18 mg/g was obtained by NTP-P-Ce-Mn-NGs at an initial pH of 11, an initial concentration of Tl(I) of 250 mg/L, and a dosage of adsorbent of 0.15 g/L. The kinetics models, including the pseudofirst-order, pseudonth-order, mixed 1,2-order, and hyperbolic tangent Ⅱ models, were all appropriate for analysing the heterogeneous adsorption process of NTP-P-Ce-Mn-NG towards Tl(I) ions under different pH conditions. The excessive OH− ions in the alkaline environment intensified the adsorption of Tl(I) ions onto the active sites of NTP-P-Ce-Mn-NGs and further strengthened the relevant chemical reactions in which the polyvalent Mn and Ce further oxidized Tl species from Tl(I) to Tl(III), induced internal dispersion of Tl ions by the nanographene into the molecular structure and achieved chemical immobilization.

Evaluation of thallium ion as an effective ion in human health using an electrochemical sensor

Exposure to thallium (Tl), a noxious heavy metal, poses significant health risks to both humans and animals upon ingestion. Therefore, monitoring Tl levels in the environment is crucial to prevent human exposure and reduce the risk of developing severe health problems. This paper presents the development of a highly sensitive Tl ions sensor through surface modification of a glassy carbon electrode with a nanocomposite comprising MnO2 magnetic sepiolite and multi-walled carbon nanotubes (MnO2@Fe3O4/Sep/MWCNT/GCE). Multiple methodologies were employed to assess the performance of the newly developed sensor. By employing square wave anodic stripping voltammetry (SWASV) to optimize the measurement conditions, notable enhancements were observed in the stripping peak currents of Tl (I) on the MnO2@Fe3O4/Sep/MWCNT/GCE surface. The effectiveness of the nanocomposite in facilitating electron transfer between the Tl (I) ions (guest) and the electrode (host) was demonstrated from the enhanced signals observed at the different modified electrode surfaces under optimal conditions. The developed sensor displayed a wide linear range of 0.1–1500 ppb for Tl (I) and a low detection limit of 0.03 ppb for Tl (I). It was found to be selective for Tl (I) ions while remaining unaffected by interfering non-target ions in the presence of the target ions. Despite its simple preparation procedure, the modified electrode exhibited high stability and excellent reproducibility for measuring Tl (I). The outstanding electroanalytical performances of the MnO2@Fe3O4/Sep/MWCNT/GCE electrode enabled its successful use as an ultrasensitive sensor for determining trace amounts of Tl in environmental samples.

Effect of Stereochemically Active Electron Lone Pairs on Magnetic Ordering in Trivanadates.

Stereoactive electron lone pairs derived from filled 5/6s2 states of p-block cations are an intriguing electronic and geometric structure motif that have been exploited for diverse applications such as thermoelectrics, thermochromics, photocatalysis, and nonlinear optics. Layered trivanadates are dynamic intercalation hosts, where the insertion of cations can be used to tune electron correlation, charge localization, and magnetic ordering. However, the interaction of 5/6s2 stereoactive electron lone pairs with layered trivanadates remains unexplored. In this study, we contrast s- and p-block trivanadates and map off-centering in the coordination environment and reduction in symmetry arising from the stereochemical activity of lone pair cations to the emergence of filled antibonding lone-pair 6s2-O 2p hybridized states. The former is studied by high-resolution single-crystal X-ray diffraction studies of TlV3O8 and isostructural RbV3O8 to probe distinct differences in Tl and Rb coordination environments and the resulting modulation of V-V interactions in V3O8 slabs. The latter has been probed by variable-energy hard X-ray photoelectron spectroscopy (HAXPES) measurements, which manifest orbital-specific contributions from bonding and antibonding interactions of stereoactive Tl 6s2 electron lone pairs in TlV3O8. The spectroscopic assignment of valence band states to stereoactive lone pairs is further corroborated by first-principles electronic structure calculations, crystal orbital Hamilton population analyses, and electron localization function maps. The presence of the Tl 6s2 electron lone pair in TlV3O8 brings about the off-centering of Tl+ cations, which leads to anisotropy in Tl-O bonds. The off-centering of Tl ions weakens V-O bonds in one direction, which subsequently strengthens directional V-V coupling. Magnetic measurements reveal ferromagnetic signatures for both RbV3O8 and TlV3O8. However, the differences in V···V interactions significantly affect the energy balance of the superexchange interactions, resulting in an ordering temperature of 140 K for TlV3O8 as compared to 125 K for RbV3O8. The results demonstrate the distinctive effects of stereochemically active lone pairs in modifying electronic structure near the Fermi level and for mediating superexchange interactions.

Evaluation of the electronic properties of layered TlPbI3 perovskites

TlPbI3 is a new three-dimensional layered halide perovskite with special optoelectronic properties. Simulations of unique geometric and electronic structures showed that in contrast to ordinary halide perovskites, the Tl ion orbitals significantly contribute to the bonding interactions. We simulated the low-temperature changes in the TlPbI3 lattice by contracting the lattice constant and found that the bond angles decreased with lattice shrinkage, which reveals a significant lateral displacement between the atoms in the TlPbI3 crystal; this leads to reinforced bonding interactions between Tl, Pb, and I ions. Stronger bonding interactions generate more dispersive band edges, thereby increasing the bandwidth and reducing the bandgap. Moreover, the enhanced dispersion of the band edges resulted in reduced effective carrier masses and anisotropic transport properties. This provides a strategy for modulating the physical performance of new perovskites.

Cathode Nanophosphors

High-current cathodic pulses on an aluminum electrode in solutions containing sufficiently high concentrations of Mg, Ca, Sr, Al, Sc, Y, or La nitrates in a mixture with H3BO3, HF, H3PO4, or H4P2O7 are accompanied by an intense intrinsic luminescence of a number of heavy metals, the ions of which are captured by salt nanofilms and luminescence under the action of hot electrons when are in an environment characteristic of crystal phosphors. The effect of the cathode nanophosphor (CNP) was found in more than 100 systems; photographs are presented for most of the systems. Ga, In, Tl, Ge, Sn, Pb, Mn, Cu, Ag, Cd, Ce, Tb, and Zr ions were activators. The effect of matrix composition on the spectral and kinetic characteristics of the CNP was shown on several examples; a qualitative description of the phenomenon is given, and the prospects for its application to chemical analysis are considered.

Synthesis of nonthermal plasma-irradiated polyvalent manganese (hydro)oxide functionalized nanosilica for intensifying geopolymerized solidification/stabilization of thallium-contaminated soil and mechanism exploration

Thallium (Tl) enrichment in soils can cause an immeasurable ecological disaster, disturbing ecological balance and threatening human health. In this study, nonthermal plasma (NTP) irradiation was employed to synthesize polyvalent Mn-based (hydro)oxide-functionalized nanosilica (NTP-P-Mn-nSi). Mixtures of alkali-activated geopolymers and NTP-P-Mn-nSi were subsequently prepared for the efficient solidification and stabilization (S/S) of Tl-containing soils. The synthesis of NTP-P-Mn-nSi and the geopolymerization of soils were both optimized to obtain maximum adsorption capacities and achieve excellent immobilization of the matrix. The influence of the initial pH and concentration of Tl+ on NTP-P-Mn-nSi was investigated. The leaching concentration of Tl and the compressive strengths from the soil matrix were monitored. Comprehensive strategies were adopted for soils and solidified samples to investigate the vital role played by NTP-P-Mn-nSi in the geopolymers of soils. The pseudofirst-order, intraparticle, and Elovich models were suitable for evaluating the uptake dynamics of Tl+ to NTP-P-Mn-nSi. Langmuir, Freundlich, and Tempkin were all appropriate in analysing the isotherms of heterogeneous adsorption. Four maximum monolayer adsorption capacities of NTP-P-Mn-nSi responding to Tl+ ions reached 93.90, 123.00, 355.87, and 323.62 mg/g at initial pH values of 7, 9, 11, and 13, respectively. NTP-P-Mn-nSi in the geopolymer explicitly inhibited leaching and intensified the immobilization of Tl ions in the matrix with the lowest leaching concentration of 0.16 µg/L Tl from the matrix being achieved. The increase in NTP-P-Mn-nSi dosage accelerated the growth rates of nucleation, enhanced the formation of alkali-activated gelation, induced the formation of flocculent surfaces and three-dimensional structures, and intensified the elemental overlap between Mn and Tl in the geopolymerized matrix.

Accumulation of Thallium in Rainbow Trout (Oncorhynchus mykiss) Following Acute and Subchronic Waterborne Exposure.

The accumulation and tissue distribution of toxicants in aquatic biota can be determinative of their toxic impact to both exposed organisms and their potential human consumers. In the present study, accumulation of the trace metal thallium (Tl) in gill, muscle, plasma, and otoliths of rainbow trout (Oncorhynchus mykiss) following acute (96-h) and subchronic (28-day) waterborne exposures was investigated. Owing to known interactions between Tl and potassium ions (K+ ), plasma and muscle K+ concentrations were also determined. Branchial Tl accumulated in a dose-dependent manner in both acute and subchronic exposures, while plasma Tl was rapidly mobilized to tissues and accumulated only at exposure concentrations of 141 µg L-1 or higher. For muscle tissue, Tl concentrations at 28 days were markedly lower than those at 96 h at comparable exposure concentrations (0.9 µg L-1 ), indicating the presence of mechanisms that act to reduce Tl accumulation over time. However, after acute exposure, muscle Tl reached concentrations that, if consumed, would exceed acceptable daily intake values for this element, indicating some risk to human health from the consumption of fish from waters heavily contaminated with Tl. Otoliths showed Tl concentrations that reflected exposure concentration and length, confirming their capacity to provide insight into fish exposure history. No changes in tissue K+ concentrations were observed, suggesting that accumulation of Tl in rainbow trout plasma and muscle does not occur at the expense of K+ homeostasis. In addition to highlighting the capacity of rainbow trout to accumulate Tl to levels that exceed recommended dietary doses to human consumers, the present study provides the first data of tissue-specific Tl accumulation in an important regulatory species. Environ Toxicol Chem 2023;42:1553-1563. © 2023 SETAC.

Segregation effects of Tl and Li ions on the scintillation properties of NaI:Tl,Li single crystals

In this work, high quality NaI:Tl and NaI:Tl,Li single crystals with a size of 11 mm in diameter and 135 mm in length were grown by the multi-ampoule Bridgman method. The concentrations of Tl and Li ions along the solidification direction were measured by the inductively coupled plasma optical emission spectrometer. The effective segregation coefficients of Tl and Li in NaI single crystals were estimated as 0.26 and 0.35, respectively. The radioluminescence spectra under X-ray excitation, pulse height spectra and scintillation decay kinetics under γ-ray excitation of the samples taken from different solidification positions in NaI:Tl and NaI:Tl,Li single crystals were systematically studied. For RL spectrum and scintillation decay time, there is a negligible position-dependent difference for both NaI:Tl and NaI:Tl,Li single crystals. In contrast, the energy resolution at 662 keV gradually deteriorates along the solidification direction, and the light yield maintains almost the same until reaching the last-to-freeze region.

Versatile Magnetic Mesoporous Carbon Derived Nano-Adsorbent for Synchronized Toxic Metal Removal and Bacterial Disinfection from Water Matrices.

Contamination of water resources by toxic metals and opportunistic pathogens remains a serious challenge. The development of nano-adsorbents with desired features to tackle this problem is a continuously evolving field. Here, magnetic mesoporous carbon nanospheres grafted by antimicrobial polyhexamethylene biguanidine (PHMB) are reported. Detailed mechanistic investigations reveal that the electrostatic stabilizer modified magnetic nanocore interfaced mesoporous shell can be programmatically regulated to tune the size and related morphological properties. The core-shell nano-adsorbent shows tailorable shell thickness (≈20-55nm), high surface area (363.47 m2 g-1 ), pore volume (0.426 cm3 g-1 ), radially gradient pores (11.26nm), and abundant biguanidine functionality. Importantly, the nano-adsorbent has high adsorption capacity for toxic thallium (Tl(I) ions (≈559mg g-1 ), excellent disinfection against Staphylococcus aureus and Escherichia coli (>99.99% at 2 and 2.5µg mL-1 ), ultrafast disinfection kinetics rate (>99.99% within ≈4min), and remarkable regeneration capability when exposed to polluted water matrices. The Tl(I) removal is attributed to surface complexation and physical adsorption owing to open ended mesopores, while disinfection relies on contact of terminal biguanidines with phospholipid head groups of membrane. The significance of this work lies in bringing up effective synchronic water purification technology to combat pathogenic microorganisms and toxic metal.

Coordination of Pnictogenylboranes Towards Tl(I) Salts and a Tl- Mediated P-P Coupling.

The coordination chemistry of only Lewis-base (LB)-stabilized pnictogenylboranes EH2 BH2 ⋅NMe3 (E=P, As) towards Tl(I) salts has been studied. The reaction of Tl[BArCl ] (BArCl =[B(3,5-C6 H3 Cl2 )4 ]- ) with the corresponding pnictogenylborane results in the formation of [Tl(EH2 BH2 ⋅NMe3 )][BArCl ] (1 a: E=P; 1 b: E=As). Whereas the Tl ion in 1 a/b is monocoordinated, the exchange of the weakly coordinating anion (WCA) in the Tl(I) salt leads to the formation of a trigonal pyramidal coordination mode at the Tl atom by coordination of three equivalents of EH2 BH2 ⋅ NMe3 in [Tl(EH2 BH2 ⋅ NMe3 )3 ][WCA] (2 a: E=P, WCA=TEFCl ; 2 b: E=As, WCA=TEF) (TEF=[Al{OC(CF3 )3 }4 ]- , TEFCl =[Al{(OC(CF3 )2 (CCl3 )}4 ]- ). Furthermore, by using two equivalents of PH2 BH2 ⋅NMe3 , a Tl(I)-mediated P-P coupling takes place in CH2 Cl2 as solvent resulting in [Me3 N⋅BH2 PH2 PHBH2 ⋅NMe3 ][WCA] (WCA=TEF, 3 a; BArCl , 3 b; TEFCl , 3 c). In contrast, for the arsenic derivatives 1 b and 2 b, no coupling reaction is observed. The underlying chemical processes are elucidated by quantum chemical computations.

Effective Thallium(I) Removal by Nanocellulose Bioadsorbent Prepared by Nitro-Oxidation of Sorghum Stalks.

Thallium(I) (Tl(I)) pollution has become a pressing environmental issue due to its harmful effect on human health and aquatic life. Effective technology to remove Tl(I) ions from drinking water can offer immediate societal benefits especially in the developing countries. In this study, a bio-adsorbent system based on nitro-oxidized nanocellulose (NOCNF) extracted from sorghum stalks was shown to be a highly effective Tl(I) removal medium. The nitro-oxidation process (NOP) is an energy-efficient, zero-waste approach that can extract nanocellulose from any lignocellulosic feedstock, where the effluent can be neutralized directly into a fertilizer without the need for post-treatment. The demonstrated NOCNF adsorbent exhibited high Tl(I) removal efficiency (>90% at concentration < 500 ppm) and high maximum removal capacity (Qm = 1898 mg/g using the Langmuir model). The Tl(I) adsorption mechanism by NOCNF was investigated by thorough characterization of NOCNF-Tl floc samples using spectroscopic (FTIR), diffraction (WAXD), microscopic (SEM, TEM, and AFM) and zeta-potential techniques. The results indicate that adsorption occurs mainly due to electrostatic attraction between cationic Tl(I) ions and anionic carboxylate groups on NOCNF, where the adsorbed Tl(I) sites become nuclei for the growth of thallium oxide nanocrystals at high Tl(I) concentrations. The mineralization process enhances the Tl(I) removal efficiency, and the mechanism is consistent with the isotherm data analysis using the Freundlich model.

Sorption behavior and mechanisms of thallium to microplastics

Thallium (Tl) is a metal of high toxicity, and the problem of Tl pollution is being faced globally. However, environmental data on Tl are still scarce and its biogeochemical behaviors remain mostly unclear. Studies have revealed the potential transport of other heavy metal by microplastics (MPs), but there is no report on the interactions between Tl and MPs yet. Therefore, we studied the adsorption of Tl by the three most commonly detected MPs, i.e., polyethylene (PE), polystyrene (PS), and polypropylene (PP) in fresh and seawater. We considered the effects of particle size, pH and competitive cations on adsorption capacity. The results showed PS has the highest adsorption capacity for Tl which was mainly through surface complexation. PS showed the lowest crystallinity and had the most oxygen-containing functional groups among the studied MPs. The adsorption of Tl on PE and PP was dominated by physical adsorption. The adsorptions exhibited significant salinity and pH dependence. Dominant cations in seawater competed with Tl ions for adsorption sites on MPs. With the increase in pH, the deprotonation of the carboxyl functional groups on MPs was enhanced, which increased the effective adsorption sites and promoted the adsorption of Tl. However, the adsorption capacity of the studied MPs for Tl was much lower than the corresponding capacity of natural minerals (clay, iron and manganese oxides) previously reported. Therefore, MPs may not be the main factors affecting the environmental behavior of Tl. This study provides valuable information for the study of thallium’s environmental behavior and ecological risk assessment.

Analyzing the Quality of Dialysis Machines Input Water in Hospitals of Kashan City, in 2019

Introduction: According to high volumes of water used in hemodialysis, quality of water entering the dialysis machine is very important. The current study aims to analyze microbial and chemical quality of water used for hemodialysis in hospitals of Kashan city in 2019.&#x0D; Materials and Methods: This descriptive cross-sectional study was performed on 54 water samples used in dialysis machines in hospitals of Kashan city during 3 months of the fall season in 2019. Microbial tests of the samples were done, and also heavy metals were assessed using inductively coupled plasma optical emission spectrometry. Statistical tests, sample t-test, and ANOVA were used to compare the mean results with standards.&#x0D; Results: Based on the results, the mean concentrations of magnesium (Mg) (2.7 ± 2.22 mg/L), sulfate (13.09 ± 21.06 mg/L), sodium (Na) (17.27 ± 24.47 mg/L), and potassium (K) (0.09 ± 0.17 mg/L) in all samples were based on the standard levels. However, the mean concentrations of nitrate (3.22 ± 1.21 mg/L), aluminum (Al) (0.26 ± 0.16 mg/L), silver (Ag) (0.52 ± 0.85 mg/L), lead (Pb) (0.08 ± 0.13 mg/L), and zinc (Zn) (0.91 ± 0.71 mg/L) were above standard levels in all the samples. Thallium (Tl) ion was reported to be zero. Moreover, heterotrophic bacteria were not observed in any of the samples.&#x0D; Conclusion: Given the high concentration of chemicals and heavy metals in dialysis machines water input, it is necessary to plan for periodic monitoring of water treatment systems and heavy metals and regular replacement of reverse osmosis filters.

Potential application of Fusarium fungal strains (Fusarium sp. FP, Arthrinium sp. FB, and Phoma sp. FR) for removal of Tl (I) ions from water.

Water pollution caused by heavy metals poses a serious threat to the ecosystem and human health. Among the various treatment techniques for water remediation, adsorption is an efficient method due to its high capacity, low cost, and simplicity. Thallium (Tl) is highly toxic to mammals and its removal from water is gaining increasingly prominent attention. In this study, three fungal strains (Fusarium sp. FP, Arthrinium sp. FB, and Phoma sp. FR) were tested for removal of Tl (I) from aqueous solutions and showed excellent removal performance. The prepared inactive fungal strains were characterized by XRD, FT-IR, SEM, and XPS analyses. The effects of pH, contact time, biomass dosage, and reaction temperature on the removal efficiency of Tl (I) were systematically investigated. The results indicated that the adsorption isotherm data fit well with the Langmuir model, and the pseudo-second-order model was more consistent with the kinetic data description. The maximum adsorption capacity of the fungal strain (Fusarium sp. FP, Arthrinium sp. FB, and Phoma sp. FR) for Tl (I) was found to be 94.69mg/g, 66.97mg/g, and 52.98mg/g, respectively. The thermodynamic data showed that the sorption process was spontaneous and endothermic. The present study showed that the inactive fungal strains could be a promising adsorbent material for Tl (I) removal.

The physical and photocatalytic properties of thallium doped cobalt ferrites for efficient hydrogen fuel production

Herein, a series of CoFe2-xTlxO4 (0.03 ≤ x ≤ 0.15) nanoceramics were prepared via a meso-2,3-dimercaptosuccinic acid assisted solvothermal route. The influence of a thallium ion dopant on the structural, magnetoptical, electrical, and photocatalytic characteristics has been scrutinized. The X-ray diffraction demonstrated that CoFe2-xTlxO4 nanoceramics have a cubic structure at all Tl ions concentrations. The Raman scattering spectroscopy revealed the reshuffling of the iron cation between the tetrahedral and octahedral sites of the structure of ferrite due to the substitution with Tl ions. The magnetic properties showed an increase of the saturation magnetization from 59.5 emu/g to 67.4 emu/g and an increase of the coercive field from 344.2 Gauss to 583.1 Gauss with increasing the amount of Tl cations. The optical band gap decreases with the increase of Tl ion concentration. The activation energy decreases from 0.44 eV to 0.26 eV with increasing the Tl ion concentration. These unique physical properties gave rise to the outstanding capability of the as-synthesized CoFe2-xTlxO4 nanoceramics for the photocatalytic production of hydrogen fuel.

LDPE cracking over mono- and divalent metal-doped beta zeolites

This study evaluates the effect of loading various mono and divalent metals in Beta zeolite on low-density polyethylene (LDPE) cracking. We revealed that Tl and Ba ions enhanced Lewis acidity, leading to higher catalytic activity on LDPE cracking.

PH-dependent Release Matrix Oral Formulation of Prussian Blue to Improve its Efficacy as an Internal Decorporation Agent.

Prussian Blue (PB) is available as conventional release dosage form "Radiogardase" with effective daily dose of 3-10 g (very high). The target site is the duodenum, where it inhibits the enterohepatic circulation of Cs & Tl ions, enhancing their fecal excretion. To enhance efficacy, target release, reduce the dose and side effects, oral pH-dependent matrix formulation of PB based on in-situ gelation of sodium alginate along with calcium salts was formulated and evaluated. Different combinations of matrix granules were formulated and optimized. The optimized one was compressed using Polyvinylpyrrolidone K30 (Pvp K30) in different batches and optimized. Langmuir adsorption isotherm was used to assess in-vitro binding efficacy of formulation to thallium using atomic absorption spectroscopy. The proof of concept i.e., drug release in the duodenum was studied through pharmacoscintigraphy using radiolabeled formulation in rabbits. The optimized granules showed no drug release in an acidic medium for 2 h whereas complete empty of the basket in a basic medium within 30-60 minutes. The matrix tablet formulation with Pvp K30 (10% w/w) was optimized with desired hardness and optimum in-vitro release profile. The release data fitted to various linear kinetic models, Hixson-Crowell r2 (0.9906) best fit, confirmed the erosion-based release mechanism. The maximum binding capacity (MBC) was found significantly higher (89.60 mg Tl/g formulation) than that of PB API (65.90 mg Tl /g PB API). Pharmacoscintigraphic images confirmed intact formulation in the stomach up to 2h and burst release in intestine thereafter. The results exemplify oral pH-dependent PB matrix formulation which achieved desirable target release at the duodenum and in-vitro binding efficacy towards Tl ion was appreciable.