Acidic Waste Solutions Research Articles

A "Two-Step" Electrochemical Approach for Recovery of Plutonium and Uranium from Aqueous Acidic Waste Solutions.

Chemical quality control of nuclear fuel, particularly the determination of Pu and U contents by chemical methods, results in analytical acidic aqueous waste solutions from which Pu and U must be recovered efficiently for the remediation of radioactive wastes. Reported methods involve several complicated steps requiring addition of chemical oxidants/reductants for valence adjustments and generation of secondary wastes, thereby making the recovery process cumbersome. Herein, we report a novel two-step electrochemical approach for Pu and U recovery from acidic aqueous waste solutions containing different metallic impurities (Fe, Cr, Mn, Cd, Al, Ni, Co, Zn, and Mg) by bulk electrolysis using a Pt gauze electrode. Pu and U are recovered from these waste solutions in a two-step process: (i) bulk electrolysis of the mixed solution at a constant potential of 0.1 V vs Ag/AgCl/3 M KCl that results in the reduction of PuO22+ to Pu3+ followed by the precipitation of Pu3+ as K2(K0.5Pu0.5)(SO4)2, which is then filtered and separated and (ii) the filtrate solution is again subjected to bulk electrolysis at a constant potential of -0.35 V vs Ag/AgCl/3 M KCl resulting in the reduction of UO22+ to U4+. The U4+ is then precipitated as K2(K0.67U0.33)(SO4)2, which is filtered and separated, leading to a Pu- and U-free aqueous acidic waste solutions. Biamperometry shows that 97.8% and 99.1% recovery of Pu and U, respectively, is possible, and emission spectrometry confirms the purity of K2(K0.5Pu0.5)(SO4)2 and K2(K0.67U0.33)(SO4)2. Because of its operational simplicity, potential for remote handling, and excellent extraction efficiency, the present methodology can easily replace traditional methods for the recovery of Pu and U from acidic aqueous waste solutions.

BHOEOCC6/n-dodecane: A new solvent extraction media for Cs removal from nuclear waste without using any phase modifier

Modifier-free diluent is most advantageous in hydrometallurgical route for separation of any radioactive element from high level liquid waste (HLLW). However there is not even a single calix crown reported in the literature that is soluble in pure n-dodecane and shows very high Cs extraction from such high nitric acid condition of 4.0 M prevalent in HLLW. Herein we designed a new calix crown-6-ether with an aim to reduce polarity so as to increase solubility in n-dodecane for extraction of Cs by density functional theory (DFT). The theoretically designed calix crown has been synthesised by introducing two 2-(hexyloxy)ethoxy alkyl arms at 1, 3 position calix[4]-arene framework and abbreviated as BHOEOCC6. Characterisation of BHOEOCC6 was carried out using 1H NMR, 13C NMR, and ESI-MS etc. techniques. 0.1 M BHOEOCC6/n-dodecane mixture shows exceptionally high stability as well as high Cs extraction ability (DCs = 10.75 @ 4.0 M HNO3) from highly acidic nuclear waste solution. The mechanism and interaction of Cs with BHOEOCC6 were also probed by experimental distribution ratio studies and instrumental techniques of UV–VIS titration and NMR studies of Cs-BHOEOCC6 complex.

Synthesis, characterization and uptake studies of diglycolamic acid and diglycolamide analogs adsorbents for extraction of rare earth elements

Tetraalkyldiglycolamides are known for their high extracting efficiency of rare earth elements (REEs) from nitric acid solutions (1–6 mol/L). Nevertheless, solid-phase extractants based on diglycolamides (DGA) are poorly studied for REEs extraction. This paper explores the design and synthesis of novel REEs adsorbents by grafting silica with diglycolic acid-based ligands. The newly developed solid-phase materials were investigated for their potential to effectively separate REEs from various media. The functionalization of the silica with different ligands was quantified, and the adsorbents' extraction capacities and selectivity for REEs over Calcium (Ca2+), Aluminium (Al3+) and Iron (Fe3+) were evaluated. Si-NH-DGA emerged as the most efficient adsorbent for Gd3+ extraction, exhibiting a remarkable capacity of 44 mg/g at pH 4–6. However, modifications involving ether oxygen substitution with a methylamino group or sulfur led to reduced extraction efficiencies. Si-NH-DGA-NMe2 demonstrated strong binding of REEs in nitric acid solutions (1–3 mol/L HNO3) with corresponding adsorption capacities for Y3+, La3+, Gd3+ and Yb3+ being 16.3, 14.2, 22.8, and 30.2 mg/g, respectively. Furthermore, it displayed remarkable selectivity for REEs over Ca2+. The equilibrium extraction for Gd occurred within 60 min for Si-NH-DGA and Si-NH-DGA-NMe2 under their respective optimal conditions. Disodium EDTA solution demonstrated a high stripping efficiency for Gd3+ in the Si-NH-DGA-NMe2 column extraction, yielding a significant concentration factor (CF = 85). In the same column, following five cycles of loading/stripping of Gd3+, there was an average capacity loss of 6%. Si-NH-DGA-NMe2 emerged as a promising material for solid-phase extraction from concentrated nitric acid solutions, characterized by high capacity and good selectivity towards middle and heavy REEs. This structure has the potential to be further optimized for the development of a solid-phase extraction column for REEs separation and purification. The findings also highlight the potential of Si-NH-DGA-NMe2 as a candidate for REEs adsorption for potential industrial applications and the purification of acidic waste solutions.

Experimental and Theoretical Investigation on the Extractive Mass Transfer of Eu3+ Ions Using Novel Amide Ligands in 1-Hexyl-3-methylimidazolium Bis(trifluoromethylsulfonyl)imide.

Novel amide ligands in the ionic liquid (1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) were utilized for the liquid-liquid biphasic mass transfer of Eu3+ ions from aqueous acidic waste solution. The cation exchange mechanism was found to be operative with the formation of [Eu(NO3)2L3]+ species (L = 4-chloro-N-(1-methyl-1H-pyrazol-3-yl)picolinamide). However, the presence of an inner-sphere water molecule was revealed by density functional theory (DFT) calculations. The viscosity-induced slower kinetics was evidenced during mass transfer, which was improved by increasing temperature. The process was exothermic in nature. The improvement in the kinetics of extractive mass transfer at higher temperatures is evinced by a reduction in the distribution ratio value. The spontaneity of the reaction was evidenced through the negative Gibbs free energy value, whereas the process enhances the entropy of the system, probably by releasing water molecules at least partially during complexation. The structures of bare ligands and complexes have been optimized by using DFT calculations. A high value of complexation energy, solvation energy, and associated enthalpy and free energy change reveal the efficacy in binding Eu with O and N donor atoms. In addition, natural population analysis, atoms-in-molecules analysis, and energy decomposition analysis have been employed to explore the nature of bonding existing in Eu-O and Eu-N bonds.

Highly efficient and selective adsorption of palladium(II) from simulated nuclear waste solution using Amberlite XAD-7 resin impregnated with a phenanthroline-derived diamide

The increasing demand and limited natural resources for rare precious metal palladium render its separation and recovery from secondary sources such as acidic nuclear liquid waste greatly interesting. Herein, a novel Et-Tol-DAPhen extraction resin was prepared by impregnating Amberlite XAD-7 resin with a phenanthroline-derived diamide extractant N,N′-diethyl-N,N′-ditolyl-2,9-diamide-1,10-phenanthroline (Et-Tol-DAPhen), and the adsorption behavior of this new extraction resin towards Pd2+ in HNO3 solution was investigated through the batch and column experiments. The Et-Tol-DAPhen extraction resin exhibited strong adsorbability, high adsorption capacity, excellent selectivity and good reusability for Pd2+ in highly acidic HNO3 solution. In addition, the pseudo-second-order and Langmuir models were applied to understand the adsorption process of Pd2+ on Et-Tol-DAPhen extraction resin, respectively. It demonstrated the characteristics of a uniform single-layer chemisorption. The maximum uptake capacity could reach as high as 74.6 mg g−1 for Pd2+ in 3.0 mol/L HNO3 solution which is much higher than most adsorbent materials of palladium reported before. Furthermore, Et-Tol-DAPhen extraction resin could selectively uptake Pd2+ from a simulated acidic nuclear waste solution containing 20 different kinds of ions with the separation factor SFPd/M values as high as 100 to 10,000. Moreover, although the adsorption efficiency had a slight decrease after 5 times of adsorption-desorption process, it still remained at a high level. This new extraction resin displayed a potential application prospect in the field of separation and recovery of Pd2+ from acidic nuclear liquid waste.

Combining Membrane and Zero Brine Technologies in Waste Acid Treatment for a Circular Economy in the Hot-Dip Galvanizing Industry: A Life Cycle Perspective

An innovative approach of combining membrane and zero brine technologies for a joint treatment of industrial liquid waste is investigated regarding its environmental impacts compared to the existing liquid waste treatment. The object of investigation is the generation of waste acid solution by a hot dip galvanizing plant in Sicily, Italy. The waste acid solution contains hydrochloric acid, iron and zinc, which makes it a hazardous waste according to EU classifications. Environmental impacts are studied for two scenarios in the Tecnozinco hot-dip galvanizing plant in Sicily, Italy: (i) the current process of pickling with linear disposal of waste acid and (ii) the pickling combined with in-situ treatment of the waste acid using a combination of diffusion dialysis (DD), membrane distillation (MD) and a precipitation reactor. Results are obtained via an attributional life cycle assessment (LCA) approach focusing on the water footprint profile of the process. The linear disposal path creates significant costs, environmental burdens and risks during the 1500 km transport of hazardous liquid waste. The combination of DD and MD, complemented with a zero-brine precipitation reactor, closes internal material loops, could save local water resources and reduces costs as well as environmental impacts. Reduction potentials of 70–80% regarding most LCA impact categories can be expected for the application of the novel technology combination supporting the galvanizing pre-treatment process under study. Therefore, the application of such technology on the way forward to a more circular economy is recommended from an environmental viewpoint, especially in process plants similar to the investigated one.Graphical

Recovery of actinides from acidic waste solutions generated in research facilities using adsorption and extraction techniques

Recovery of actinides from acidic waste solutions generated in research facilities using adsorption and extraction techniques

Recovery of scandium from acidic waste solutions by means of polymer inclusion membranes

Scandium is a raw material with properties that promise considerable potential for application in alloys to enable aviation fuel savings and as dopants for use in sustainable energy production using solid oxide fuel cells. Despite these attractive properties, scandium is rarely used due to its scarcity and unreliable supply. Therefore, new strategies for scandium recovery are of economic priority. In this study, polymer inclusion membranes (PIMs) consisting of PVDF-HFP, 2-NPOE and DEHPA, were optimised for selective scandium separation from real TiO2 production waste. With the optimised system, >60% of the scandium was recovered with high selectivity, resulting in scandium mole fraction at more than two orders of magnitude higher in the receiving phase than in the original waste. This suggests PIMs may be an effective way to recover scandium from bulk waste, thus easing the scarcity and insecurity that currently limit its bulk application.

DFT-based study on the molecular interaction of hydrochloric acid with different extractants

As an important chemical raw material, hydrochloric acid widely exists in various chemical production processes. After being used in industrial production, an acidic waste solution will be produced, creating a need to recover hydrochloric acid from the waste solution. Solvent extraction is considered to be an efficient and easy-to-operate method. This paper uses DFT theory to study the binding characteristics of different kinds of extractants and hydrochloric acid molecules. The comprehensive analysis of RDG, AIM, and ELF found that hydrogen proton transfer occurs during hydrochloric acid extraction by amine extractants, and HCl is extracted by ionic association. At the same time, alcohols, ketones, esters, and neutral phosphorus-containing species are all bonded with HCl in the form of a hydrogen bond. In addition, by studying the changes of Gibbs free energy before and after the extraction process, it was found that amines had the most potent binding force to HCl. Moreover, the binding force of TEHA to HCl is much smaller than that of other amines, which not only retains the ability to extract HCl but also makes it have excellent stripping performance. Finally, the results of the DFT calculation are verified by experiments.

The preparation of slow-release fertilizers with biomass ash and water/waste acid solutions from desulfurization and denitrification of flue gas.

In this study, a method of preparing fertilizers with the fly ash from biomass power plants and the waste acid solution from flue gas desulfurization and denitrification was disclosed. In addition, the study also explored the effects of added fine particles, unburned biochar, and other commercial fertilizers on soil water retention and slow-release effect of fertilizers. The analysis was done by comparing the aggregation degrees of crystalline salt and the variations of the chemical bonds. The experimental results showed that the added fine particles could effectively increase the water absorption of fertilizers, which helped to improve soil water retention. Meanwhile, the fine particles could strengthen the special adsorption of basic compounds containing N, P, and other nutrients by biochar and enhance the slow-release effect of fertilizers. Although adding part commercial fertilizers weakened the water absorption of fertilizers slightly, it had only a relatively small effect on the aggregation of water-soluble crystalline salt on the surfaces of fine particles and biochar. Furthermore, the microwave was applied to promote the absorption of N by unburned biochar, during which only small amounts of volatile were released and lost. The experiments had confirmed that microwave irradiation could promote the agglomeration of biochar on crystalline salt effectively, thus enhancing the slow-release effect of crystalline salt in fertilizers. Finally, pot experiments demonstrated that the self-prepared fertilizer improved plant growth by its better water absorption and slow-release properties during the whole growth period, which had promising application potential as the slow-release fertilizer in the plant growth field.

Polyphosphate‐Grafted Fe3O4 Nanomagnets for the Removal of Trivalent Radionuclides from Acidic Nuclear Waste Solution

AbstractThe removal of radionuclides from nuclear waste solution is one of the biggest environmental challenges in today's world. In this aspect, polyphosphate grafted Fe3O4 nanomagnets (PPNMs) were investigated for its efficiency in removal of trivalent radionuclides from acidic nuclear waste solution. Various characterization techniques like XRD, FTIR, TEM and DLS were used to characterize these PPNMs, which showed successful formation of single phase, polyphosphate functionalized aqueous stable Fe3O4 nanostructure with average size ∼10 nm. The kinetics of sorption for Am(III) and Eu(III) by the PPNMs was found to be very fast with equilibrium being attained within ∼5 min. The sorption of both the radionuclides was following pseudo second order kinetic model. With increasing pH of the solution, the sorption efficiency of PPNMs for both the radionuclides was found to increase, whereas it decreased with increasing ionic strength of the medium. These observations clearly suggested that the sorption process proceeds through electrostatic interaction between the nanomagnets and trivalent radionuclides. Moreover, the PPNMs retained their sorption efficiency for at least 10 successive cycles when desorbed with 0.2 M HNO3. Thus, these magnetic nanosorbents can be used as highly effective, separable and reusable materials for removal of trivalent radionuclides from acidic nuclear waste solution.

Dipicolinamide functionalized titania for highly efficient sorption of tetra and hexavalent actinide

Dipicolinamide functionalized titania particles have been synthesized for efficient decontamination of uranyl and thorium ions from aqueous acidic waste solution. Langmuir isotherm was found to be predominating with maximum sorption capacity of 125 mg/g for Th and 111 mg/g for U, respectively. The sorption was found to follow pseudo 2nd order kinetics predominately, with rate constant 8.6E−04 mg g−1 min−1 for Th and 6.1E−04 mg g−1 min−1 for U, respectively. Up to 200 kGy of gamma irradiation, not much deterioration in extraction performance of sorbent material was observed. Three contacts of 0.1 M aqueous solutions of oxalic acid and sodium carbonate were found to be effective in quantitative elution of Th4+ and UO22+ from the loaded sorbent, respectively. The sorption of U and Th on dipicolinamide functionalized titania was evidenced by SEM images, elemental mapping and the EDX. Theoretical investigation revealed that, the solution phase free energy of sorption (ΔGsol) was higher for Th4+ (−114.1 kcal mol−1) compared to UO22+ (−80.41 kcal mol−1).

Understanding the extraction behaviour of UO22+ and Th4+ using novel picolinamide/N-oxo picolinamide in ionic liquid: A comparative evaluation with molecular diluent

The manuscript deals with efficient separation of hexavalent UO22+ and tetravalent Th4+ from aqueous acidic waste solution in ‘green way’ using ionic liquid with novel picolinamide (L I) and N-oxo picolinamide (L II) based ligands. A comparative evaluation was carried out to understand the extraction mechanism, kinetics, thermodynamics, speciation, radiolytic stability and stripping behaviour of UO22+ and Th4+ in ionic liquid vis-a-vis molecular diluent. The investigation demonstrates the predominance of ‘cation exchange’ mechanism in ionic liquid and ‘solvation' mechanism in n-dodecane based systems. The slower extraction kinetics in ionic liquid was attributed to the ‘viscosity effect’. The extractive mass transfer processes were found to be spontaneous, endothermic and entropically driven in nature. The picolinamide and N-oxo picolinamide ligands were found to form inner-sphere complexes in ionic liquid as well as n-dodecane. In molecular diluent, the species involved for separation of UO22+ were UO2(NO3)2. 2 LI and UO2(NO3)2. L II, respectively, whereas in ionic liquid thet were [UO2(NO3). 2 L]+ and [UO2(NO3). L]+. For Th4+, in molecular diluent, the most plaussible extracted species were Th(NO3)4. 2 L I and Th(NO3)4. L II, while in ionic liquid they were [Th(NO3)2. 2 L]2+ and [Th(NO3)2. L]2+, respectively. Ionic liquid based solvent systems exhibited more radiolytic stability compared to that in molecular diluent. The CO32− was more effective aqueous phase complexing agent to back extract UO22+, while C2O42− exhibited the same for Th4+.

Study on regeneration and desiliconization purification of pickling waste liquid of building steel

In this paper, Fe2O3 power was used to replace the scrap steel in the traditional process, as the medium for removing the free acid in the waste acid solution of the cold-rolled strip pickling. The removal effect of free acid and silicon of the system with Fe2O3 addition and crap steel were compared. The results indicated that the system with Fe2O3 addition obtained a better effect. Subsequently, the optimum dosage, optimum reaction temperature and time were determined by the orthogonal experiment. The effect of flocculants of polyacrylamide (PAM), PAC, PAM+PAC and MgCl2 with the desiliconization was explored.

Development of Technology of Arsenic Removal from Acidic Waste Solutions in the Form of Arsenic Trisulfide

During the laboratory tests the conditions of arsenic removal from acidic waste solutions of metallurgical enterprise in the form of arsenic trisulfide were determined. The technology based on the reduction of pentavalent arsenic to trivalent state with sodium pyrosulfite solution and following arsenic trisulfide precipitation from acidic solution after treatment with sodium sulfide solution was proposed. The arsenic removal proceeds with mechanical stirring, dosing the calculated amounts of reagents and collecting emissions of hydrogen sulfide. With such treatment, about 95% of arsenic, which was in the initial solution, passes into the precipitate. An enlarged laboratory experiment was carried out and the precipitate with 42.6% of arsenic and 46.9% of sulfur was obtained. The precipitate yield was ∼25.7 kg (dry weight) out of 1 m3 of the initial arsenic containing solution.
 Keywords: arsenic, arsenic trisulfide, acidic waste solutions, sodium sulfide, sodium pyrosulfite

Batch and Fixed-Bed Column Studies on Palladium Recovery from Acidic Solution by Modified MgSiO3.

Effective recovery of palladium ions from acidic waste solutions is important due to palladium’s intensive usage as a catalyst for different industrial processes and to the high price paid for its production from natural resources. In this paper, we test the ability of a new adsorbent, MgSiO3 functionalized by impregnation with DL-cysteine (cys), for palladium ion recovery from waste solutions. The Brunauer–Emmett–Teller (BET) surface area analysis, Barrett–Joyner–Halenda (BJH) pore size and volume analysis, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy and Fourier-Transformed Infrared (FTIR) spectroscopy have been performed to characterize this material. Firstly, the maximum adsorption capacity of the new obtained material, MgSiO3-cys, in batch, was studied. To establish the adsorption mechanism, the obtained experimental data were fitted using the Langmuir, Freundlich and Sips adsorption isotherms. Studies on the adsorption of palladium ions on the synthesized material were performed in a dynamic regime, in a fixed-bed column. The Pd(II) recovery mechanism in the dynamic column regime was established based on Bohart–Adams, Yoon–Nelson, Thomas, and Clark models. The obtained equilibrium adsorption capacity was 9.3 (mg g−1) in static regime (batch) and 3 (mg g−1) in dynamic regime (column). The models that best describe the Pd(II) recovery process for batch and column adsorption are Sips and Clark, respectively.

Selective recovery of silver and palladium from acidic waste solutions using dithiocarbamate-functionalized cellulose

The efficient extraction and recovery of precious metals (PMs) such as silver (AgI) and palladium (PdII) from waste sources are of high importance, as natural reserves are limited, and the metals pose an environmental concern. Consequently, a biomass-based adsorbent, dithiocarbamate-modified cellulose (DMC), was used for the selective capture of AgI and PdII from complex aqueous matrices. DMC was found to be an efficient material for the quantitative adsorption of AgI, and PdII from weak to strongly acidic media. The adsorption kinetic data of AgI and PdII were well described by the pseudo-second-order (PSO) model, and the times required to reach equilibrium were 60 min and 90 min, respectively. The Langmuir isotherm model provided the best fitting for the PM ions adsorption, and the maximum uptake capacities of DMC were evaluated as 10.97 and 4.28 mmol g−1 for AgI and PdII, respectively. After extraction, the PM ion-loaded DMC was incinerated and the metals were recovered in their pure and elemental form (Ag0 and Pd0), with a yield of >99%. The proposed technique is more straightforward than the typical adsorption–desorption-based recovery method, as employed in commercial operations. Other advantages include process simplicity, high efficiency, non-utilization of toxic eluents, and recovery of the metals in their elemental form without the use of any reductants. Furthermore, the excellent performance (extraction rate: ~99%) of DMC towards the recovery of Ag and Pd from actual waste solutions indicates the potential for the application of the process at a larger scale.

Diffusion Dialysis for Acid Recovery from Acidic Waste Solutions: Anion Exchange Membranes and Technology Integration.

Inorganic acids are commonly used in mining, metallurgical, metal-processing, and nuclear-fuel-reprocessing industries in various processes, such as leaching, etching, electroplating, and metal-refining. Large amounts of spent acidic liquids containing toxic metal ion complexes are produced during these operations, which pose a serious hazard to the living and non-living environment. Developing economic and eco-friendly regeneration approaches to recover acid and valuable metals from these industrial effluents has focused the interest of the research community. Diffusion dialysis (DD) using anion exchange membranes (AEMs) driven by an activity gradient is considered an effective technology with a low energy consumption and little environmental contamination. In addition, the properties of AEMs have an important effect on the DD process. Hence, this paper gives a critical review of the properties of AEMs, including their acid permeability, membrane stability, and acid selectivity during the DD process for acid recovery. Furthermore, the DD processes using AEMs integrated with various technologies, such as pressure, an electric field, or continuous operation are discussed to enhance its potential for industrial applications. Finally, some directions are provided for the further development of AEMs in DD for acid recovery from acidic waste solutions.

Quaternary phosphonium modified cellulose microsphere adsorbent for 99Tc decontamination with ultra-high selectivity

Decontamination of radioactive TcO4− from nuclear wastes is increasingly crucial for spent nuclear fuel reprocessing and environmental remediation. In the presence of a large excess of competitive anions, the selective separation of TcO4− is a major challenge for adsorbents. Herein, by using pre-radiation induced grafting polymerization, we have modified economical and environmentally friendly cellulose microspheres to obtain quaternary phosphonium decorated TcO4− adsorbents with an ultra-high selectivity, designated CMS-g-VBPPh3NO3. The prepared materials show adsorption capacities of 251 mg g−1 (for the surrogate Re). The selective factor against NO3− in 0.5 mol kg−1 HNO3 is as high as 168, showing excellent anion-exchange selectivity towards TcO4−. Moreover, CMS-g-VBPPh3NO3 was packed in column for treating simulated acidic waste solutions containing Cs, Sr, Eu, Zr, Ru, U and Re, and it showed excellent Re separation performance. Tracer amount of 99mTc experiments showed that comparing to ReO4−, CMS-g-VBPPh3NO3 has a better adsorption selectivity for TcO4−.

Modification of Nylon 6,6 with Trioctylphosphine Oxide for Uranium Removal from Aqueous Solution

The study deals with the uranium removal from a raffinate solution (nitric acid waste solution from the production of uranium yellowcake) using an extractant-impregnated material. A polyamide sheet (Nylon 6,6) was impregnated with trioctylphosphine oxide and tested for uranium removal. The factors affecting the impregnation process, namely, extractant concentration, impregnation time, volume/mass ratio, impregnation temperature, and diluent type were studied. The effect of the initial uranium concentration, adsorption temperature, contact time, and pH on the uranium adsorption on the prepared sheet was also studied. The uranium adsorption behavior was described using adsorption isotherms.