Adsorption Of Th Research Articles

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.

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.

Synthesis and characterization of poly(TRIM/VPA) functionalized graphene oxide nanoribbons aerogel for highly efficient capture of thorium(IV) from aqueous solutions

An ultralight three-dimensional porous network phosphonic acid functionalized polymer/graphene oxide nanoribbons aerogel (PAFP/GONRs-A) was prepared using trimethylolpropane trimethacrylate (TRIM) and vinylphosphonic acid (VPA) as monomers via solvothermal polymerization method for thorium capture from aqueous solutions. The synthesized aerogel presented a low density (10.6 mg cm−3), large specific surface area (433.2 m2 g−1) and high phosphorus content (18.2%). The adsorption process of Th(IV) on PAFP/GONRs-A was pH-dependent, spontaneous and endothermic, and well described by the pseudo-second-order kinetic and Langmuir isotherm model. Under optimal experimental conditions (10 mg of adsorbent dosage, 50 mL of solution volume, 240 min of contact time, 298 K of temperature), PAFP/GONRs-A presented an excellent high adsorption capacity of thorium, with maximum capacity of 457.9 mg g−1 at a pH of 3.0, and maximum thorium-selectivity of 87.1% at a pH of 2.0. The values of ΔG for Th(IV) adsorption on PAFP/GONRs-A were calculated to be −21.78, –23.32, −24.87 and −26.41 kJ mol−1 at 283, 298, 313 and 328 K, respectively. Density functional theory (DFT) calculations and X-ray photoelectron spectroscopy (XPS) revealed that Th(IV) ions were fixed in aerogel by coordinating with the P = O groups of PAFP/GONRs-A, and both 1:2 ratio of Th(IV) with the P = O ligands on the same graft chain and 1:4 ratio of Th(IV) with P = O ligands on two distinct graft chains could jointly contribute to the adsorption of Th(IV) on PAFP/GONRs-A. This work offers a facile approach for synthesizing the phosphonic acid functionalized graphene oxide nanoribbons aerogel and demonstrates that PAFP/GONRs-A has high potential as a candidate adsorbent for the capture of thorium from aqueous solution.

Facile separation of Th(IV) from aqueous solution by graphene hydrogel

In this work, the graphene hydrogel (GH) was fabricated, and its adsorption behavior toward Th(IV) was studied. The GH displayed a porous network structure, with a controllable size and structure. The adsorption experimental results demonstrated that the adsorption of Th(IV) on GH fitted well with pseudo-second-order kinetic model and Freundlich isotherm model, with a maximum adsorption capacity of 190.28 mg/g at pH 3.0. The adsorption of Th(IV) on GH in inner-sphere surface complexation. Solution pH has an important influence on Th(IV) adsorption of GH. In addition, the GH exhibits an excellent reusability in Th(IV) adsorption.

Removal of thorium from aqueous solution by adsorption with Cu3(BTC)2

The Cu3(BTC)2(BTC = 1,3,5-benzenetricarboxylic acid) was synthesized by water/solvent heat method. The Cu3(BTC)2 was characterized by SEM/EDS, Zeta potential and XRD. Batch static adsorption experiments investigated the various factors affecting the adsorption of Th(IV) in aqueous solution such as pH, solid–liquid ratio, contact time, initial concentration and temperature, and the adsorption mechanism is also discussed. The adsorption process was in line with the pseudo-second-order kinetic model and the Langmuir isotherm model. At the same time, compared with other adsorbents. The results showed that Cu3(BTC)2 had good adsorption for Th(IV) with a maximum adsorption of 757.58 mg g−1.

Halloysite nanotubes: an eco-friendly adsorbent for the adsorption of Th(IV)/U(VI) ions from aqueous solution

Halloysite nanotubes: an eco-friendly adsorbent for the adsorption of Th(IV)/U(VI) ions from aqueous solution

Radiation grafting of DMAEMA and DEAEMA-based adsorbents for thorium adsorption

Radiation grafting of two tertiary amine methacrylates; 2-(dimethylamino)ethyl methacrylate (DMAEMA) and 2-(diethylamino)ethyl methacrylate (DEAEMA) onto polyolefin non-woven fabric (PE/PP-NWF) was comparatively investigated in this study. In addition, the absorbent preparation process, grafting kinetics, and mechanism were investigated. The thermal properties were investigated by thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC). Fourier transform infrared (FTIR) spectroscopy was performed to confirm the successful grafting and incorporation of the two monomers functional groups onto PE/PP-NWF. X-ray diffraction (XRD) analysis was used to examine the differences between the crystal sizes and structures. Lastly, the adsorption of Th(IV) ion was investigated in batch mode. The results indicate that the radiation grafting of both DMAEMA and DEAEMA onto PE/PP-NWF required high activation energies with increasing temperatures from 313 to 333 K. Furthermore, P-DMAEMA and P-DEAEMA demonstrated different adsorption behaviours towards Th(IV). Results showed that P-DEAEMA exhibited lower Th(IV) adsorption capacity compared to P-DMAEMA, although both contain similar carbonyl and tertiary amino functional groups. These findings indicate that the molecular structure of the adsorbent was responsible. The molecular sizes increased with increasing branched carbon chains from the methyl to ethyl groups. Density functional theory (DFT) analysis indicated that induced steric effect eventually increases the inter-molecular repulsions caused by the additional CH2-groups in the structure, which reduces adsorption capacity.

Selective Th(iv) capture from a new metal-organic framework with O- groups.

Herein we report a new 4-fold interpenetrated metal-organic framework (MOF) functionalized with O- groups for selective Th(iv) capture, the activated samples 1a exhibited a high adsorption capacity for pure Th(iv) ions (Kd = 3.16 × 105 mL g-1) and the amount of metal ions adsorbed on the adsorbent was 165.61 mg g-1. A high removal efficiency of 99.75% was achieved within 10 min with an initial Th(iv) concentration of 100 mg L-1 and the adsorption data followed the pseudo-second-order model. In addition, the separation coefficient (S) of Th(iv) to metal ions with different valence states such as Th(iv)/La(iii), Th(iv)/Sm(iii), Th(iv)/Ho(iii), Th(iv)/Cd(ii) and Th(iv)/K(i) achieved values of 19.66, 26.83, 16.90, 11.26 and 255.79, respectively. Even given the fact that MOFs with O- groups showed high affinity for Pb(ii) ions, our adsorption studies for compound 1a revealed a separation coefficient (STh(IV)/Pb(II)) of 4.36. Further, the adsorption of Th(iv) ions to compound 1a was investigated by FT-IR, SEM-EDS and XPS.

Adsorption behaviours of Th(IV) and U(VI) using nitric acid (HNO3) modified activated carbon: equilibrium, thermodynamic and kinetic studies

ABSTRACT In order to research the sorption of thorium(IV) and uranium(VI) ions from aqueous solutions, the granular-activated carbon was modified with nitric acid. The modified adsorbent was identified by BET, elemental analysis, SEM and FTIR method. The influences of different parameters such as pH, contact time, temperature and initial concentration were investigated using batch system. Adsorption of Th(IV) and U(VI) onto modified carbon has been evaluated in terms of equilibrium, kinetics and thermodynamics studies. When the obtained results of thorium(IV) and uranium(VI) sorption onto modified adsorbent was applied to kinetic models, it was observed that the experimental results much better fitted the pseudo-second-order kinetic model. Adsorption process was better explained by Langmuir isotherm in comparison with other isotherms. Thermodynamic data were calculated from the sorption isotherms. Results suggested that the adsorption of Th(IV) and U(VI) on modified adsorbent was an endothermic and spontaneous process.

Thorium ions adsorption from aqueous solution by amino naphthol sulphonate coupled chitosan

ABSTRACT A designed new adsorbent by coupling chitosan and 1-Amino-2-naphthol-4-sulphonic acid to get an excellent synergistic effect of 1-Amino-2-naphthol-4-sulphonic coupled chitosan (ANSC) which used for the removal of tetravalent thorium ions. The modified chitosan adsorbent was identified by BET isotherm studies, elemental analysis, SEM, EDX and FT-IR, techniques. The FT-IR confirmed the structure of the modified chitosan. Langmuir isotherm model described the adsorption results with the 252.57 mg/g maximum adsorption capacity. It should be perceived that the thorium ions adsorption matched more careful with the kinetics pseudo-second-order. It was found that the adsorption of Th(IV) is strongly dependent on pH and time.

Adsorptive uptake Th(IV) by red soil and black soil

Adsorption of Th(IV) on red soil and black soil was studied as a function of ionic strength, pH, solid–liquid ratio, contact time, temperature and initial concentration through batch static tests, and the soils were characterized by SEM, XRD and IR. The results showed that the adsorption reaction was rapidly and greatly affected by pH. The experimental data conformed to the Freudlich model and the pseudo-second-order kinetic model, reflecting nonlinear chemical adsorption. Furthermore, the intra-particle and liquid film diffusion occurred simultaneously during the Th(IV) adsorption on the soils, and adsorption reaction was controlled by cation exchange reactions. According to adsorption thermodynamics in this experiment, the adsorption of Th(IV) on these two soils was found to be a spontaneous and endothermic process. Both soils were good adsorbents; however, the adsorption rate of black soil was faster, and its adsorption capacity was larger.

Adsorption of Th(IV) from aqueous solution by the graphene oxide nanoribbons/chitosan composite material

In order to reduce the potential toxicity to the environment after treatment of radioactive waste water, an eco-friendly graphene oxide nanoribbons/chitosan (GONRs-CTS) composite was prepared and utilized for adsorption of Th(IV) from aqueous solution. The GONRs-CTS adsorbent was characterized by XRD, FTIR and SEM, indicating that GONRs-CTS contains a large amount of oxygen-containing groups and chitosan was successfully attached to the GONRs surface. The Th(IV) adsorption on GONRs-CTS was endothermic and spontaneous, with the maximum single layer adsorption capacity was 140.6 mg g−1 at pH = 3.0, in the contact time of 12 h. The adsorption process was consistent with pseudo-second-order kinetics and the Langmuir isotherm model.

Study on Th(IV) Adsorption Properties on Natural and Surface-Modified Red Soil

In order to study the effects of inorganic and organic modification on the adsorption properties of red soil (RS), ferric chloride (FC) and hexadecyl trimethyl ammonium bromide (HTAB) surface-modified red soil have been prepared and characterized by SEM, FT-IR and X-ray diffraction. Adsorption properties of Th(IV) on natural red soil (NRS), FC surface-modified red soil (FC-RS), and HTAB surface-modified red soil (HTAB-RS) have been investigated by batch technique. The inorganic and organic modification have been found to greatly improve the adsorption kinetics and thermodynamic properties and increase the adsorption capacity as compared with NRS. The adsorption of Th(IV) on the three adsorbents have been strongly dependent on pH and ionic strength, and intra-particle diffusion was the rate-controlling step. The non-linear pseudo-second-order kinetic model could fit the kinetics much better compared with the linear forms, and the linear and non-linear Langmuir expressions could fit the thermodynamics. The results obtained denote on successful application of inorganic and organic modification to treatment of water samples spiked to Th(IV) ions.

Adsorption of Thorium Ions Using Trioctylphosphine Oxide Impregnated Dowex 1×4 Powder

Dowex 1×4-trioctylphosphine oxide powder (DTP) was prepared, characterized, and studied as an adsorbent for the adsorption of Th(IV) from aqueous solutions. The adsorption of Th(IV) strongly depends on pH. The adsorption follows the pseudo-second-order kinetics, and the adsorption isotherms agree well with the Langmuir model with a maximum adsorption capacity of 132.1 mg g−1.

Removal of Th(IV) ion from wastewater using a proper Schiff base impregnated onto Amberlite XAD-4

An Amberlite XAD-4 resin loaded with a Schiff base ligand was used for the removal of Th(IV)ions from aqueous solution. The procedure was based on the adsorption of Th(IV) ions on Amberlite XAD-4 resin loaded with a synthesized tetradentate Schiff base bis(2-hydroxybenzaldehyde)-1,2-ethylendiimine prior to their determination by inductive coupled plasma-mass spectrometry. The effect of parameters influencing such as aqueous phase pH, contact time, adsorbent dosage and temperature dependency of the process and the effect of interfering ions was verified and discussed. Under optimal conditions (pH= 5, adsorbent amount 0.1 g, contact time 45 min, and at temperature of 25 °C) for Th(IV) ions (initial concentration 20 mg/L) were quantitatively removed from 20 mL of the sample solution. A comparison of the adsorption efficiency of the studied resin loaded with a Schiff base with those unloaded ones shows a shift for uptake of the metal ions vs. pH curves towards lower pH values by applying the loaded resin with Schiff base (about ΔpH0.5=1.9). The kinetic data corresponds well to the pseudo-second-order equation. The adsorption data for the studied ions were well fitted by the Freundlich isotherm. Thermodynamic investigation reveals that the adsorption process of the studied ions is entropy driven.

Adsorption of Th(IV) on the modified multi-walled carbon nanotubes using central composite design

Abstract Adsorption of thorium onto nitric acid modified multi-walled carbon nanotubes was investigated by central composite design as a function of contact time, pH, initial thorium concentration and temperature. The results showed that optimum uptake capacity was 65.75±2.23 mg·g−1 with respect to pH=4, initial thorium concentration of 100 mg·L−1, 25 °C and 15 min contact time. Thermodynamic parameters [standard enthalpy (ΔH 0), entropy (ΔS 0), and free energy (ΔG 0)] were calculated, and the results indicated that adsorption was endothermic. Langmuir, Freundlich and Dubinin-Radushkevich isotherms have been investigated in order to characterize the adsorption process in the range of 25–100 mg·L−1 initial thorium concentration. The Freundlich isotherm is the best suited as a model because it has the highest correlation coefficient (R2=0.9485). The pseudo-second order kinetics well defined the adsorption process.

Synthesis and Drug Delivery Property of the Magnetic Fe3O4@Silica Nanotubes

In this study, Fe3O4@silica nanotubes (Fe3O4@SiNTs) were synthesized through a co-axial electrospinning of a shell-liquid consisting of tetraethoxysilane, polyvinyl pyrrolidone, ethanol and hydrogen chloride and Fe3O4 nanoparticles (NPs) and a core-liquid of paraffin. Their microstructure and drug delivery property were evaluated. SEM observations showed that Fe3O4@SiNTs had the tubular hollow structure. The presence of magnetic component caused a magnetic separability of Fe3O4@SiNTs. After soaked in the solution of tetracycline hydrochloride (TH, one of the representative antibiotics), Fe3O4@SiNTs supported the adsorption of TH with the loading efficiency of 64±5% to produce TH-loaded Fe3O4@SiNTs. TH-loaded Fe3O4@SiNTs presented a sustained release behavior for TH after soaked in the phosphate buffer saline. After incubation with Escherichia coli (E. coli, one of the most widely used bacteria), TH-loaded Fe3O4@SiNTs exhibited strong anti-bacterial property to inhibit the growth of E. coli, indicating that the released TH was biologically active.

Thorium adsorption on graphene oxide nanoribbons/manganese dioxide composite material

A functional graphene oxide nanoribbons/manganese dioxide composite material (MnO2-GONRs) was synthesized by hydrothermal method using graphene oxide nanoribbons (GONRs) as raw material which were formed by longitudinal unzipping of multi-walled carbon nanotubes with KMnO4 and H2SO4. The microstructure of MnO2-GONRs was characterized by SEM and FT-IR. The various factors affecting the adsorption of Th(IV) in aqueous solution such as pH, solid–liquid ratio, contact time, initial concentration and temperature were investigated by batch static adsorption experiments, and the adsorption mechanism is also discussed. The results showed that MnO2-GONRs had a good adsorption effect on Th(IV) with a maximum adsorption of 166.11 mg/g.

Thorium adsorption by oxidized biochar fibres derived from Luffa cylindrica sponges

The present study deals with the preparation of oxidized biochar fibres derived from Luffa cylindrica sponges and the subsequent adsorption of Th(IV). The adsorption experiments were performed by batch-type experiments and include the effect of various physiochemical parameters, as well as characterization of the solid phases by means of spectroscopic (FTIR) and XRD measurements. The experimental data are best described by the pseudo-second order kinetic model (R2 = 0.998) and the adsorbent was found to have a relatively high adsorption capacity (qmax = 70 mg g−1) even at pH 3, attributed to the formation of inner-sphere complexes.

Efficient adsorption of Th(IV) from aqueous solution by modified SBA-15 mesoporous silica

A very effective adsorbent for thorium has been obtained by modification of Santa Barbara Amorphous (SBA-15) using the chelating agent thenoyltrifluoroacetone (TTA). The prepared adsorbent (SBA-15-TTA) was characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), surface area, porosity, and zeta potential analyses. We investigated the factors affecting Th(IV) adsorption on TTA-SBA-15, such as initial pH, contact time, temperature, and initial metal concentration. The effective initial pH for adsorption was found to be 4. The binding sites on TTA-SBA-15 adsorbent were saturated using an initial Th(IV) concentration of 100 mg L−1. The Dubinin–Radushkevich isotherm suggested a strong chemical interaction between adsorbent and adsorbate. Contact time and temperature had no significant effect on the adsorption. Therefore, the studies show that TTA-SBA-15 is a promising adsorbent to treat Th(IV)-contaminated effluents.