Removal Of Cesium Research Articles

A Prussian blue analog-based copper-aluminum layered double hydroxide for cesium removal from water: fabrication, density functional theory-based molecular modeling, and the adsorption mechanism.

A new type of adsorbent, a Prussian blue analog-based copper-aluminum layered double hydroxide (PBA@CuAl-LDH), was successfully synthesized using a one-step method for the removal of radioactive Cs+ from wastewater. The adsorption performance, characteristics and the underlying adsorption mechanism of PBA@CuAl-LDH were systematically examined. The results showed that PBA@CuAl-LDH exhibited excellent adsorption performance, with a maximum adsorption capacity of 109.2 mg g-1. Over 85% of PBA@CuAl-LDH can be recycled, and the material exhibited only a 6.6% loss in adsorption performance. The adsorption process was well-fitted using the pseudo-second-order kinetic model and the Freundlich isotherm model, revealing the surface heterogeneity of the composite adsorbent. A molecular model of PBA@CuAl-LDH was constructed by combining density functional theory and multiple instrumental characterization techniques. Our results indicate that PBA crystals can be generated between layers and on the surface. Ion exchange was revealed as the main adsorption mechanism of Cs+ by PBA@CuAl-LDH. Specifically, the interstitial spaces of the PBA crystals generated between the layers and on the surface played an important role in ion exchange. These findings provide concrete theoretical support for radioactive pollution control and have significant value in directing the fabrication of cesium removal materials and their future engineering application.

Exploiting bifunctional 3D-Printed geopolymers for efficient cesium removal and immobilization: An approach for hazardous waste management

3D-printed geopolymer lattices (3DGPLs) have recently been considered as promising candidates for hazardous waste management due to their low cost, porous nature, and excellent environmental stability. However, the ion adsorption capacity influenced by usage conditions such as multi-ion systems and radiation remains largely unexplored. Furthermore, effective strategies to immobilize adsorbed ions for long-term disposal are still lacking. This work tackles these questions by studying the Cs+ adsorption and immobilization properties of 3DGPLs in the presence of competing ions and gamma-ray radiation. Our results reveal the inhibitory intensity of Cs+ adsorption capacity by five common metal cations in seawater, ranked in the following order: Na+ > K+ > Ca2+ > Mg2+ > Sr2+. After exposure to different doses of gamma-ray radiation, the Cs+ adsorption capacity of 3DGPLs shows no significant change, demonstrating their outstanding radiation resistance. By encapsulating the Cs-containing 3DGPL with a homologous GP coating, the Cs+ immobilization rate reaches 98.545% after leaching in NaCl solution at 60 °C for 5 days. The already-high Cs+ immobilization rate can be further increased to 99.228% by sintering treatment due to the densification effect. This study not only provides microscopic insights into the adsorption of hazardous ions by 3DGPLs under usage conditions, but also offers a feasible approach to prevent the leakage of loaded ions through GP coating technology.

Sugarcane bagasse decorated by metal (Fe3+/Cu2+) ferrocyanide for effective removal of cesium from aqueous solutions

In this work, we convert the biowaste materials (sugarcane bagasse) into wealth materials via combination with metal ferrocyanide through two steps to prepare (SCB-M-FC) composite for cesium removal from aqueous solutions. Firstly, SCB was modified to be amino silane (SCB-NH2) to provide amine binding sites. Secondly, the metal (M = Fe3+or Cu2+) ferrocyanide (FC) nanomaterials grow in situ on the surface of the modified -SCB to yield SCB-M-FC. Various techniques were used to characterize the prepared composite materials before and after the adsorption of cesium. The adsorption behavior of Cs+ by SCB, SCB-NH2, and SCB-M-FC under different conditions was studied and compared. We observed that the SCB-Cu-FC presents the experimental adsorption capacity for Cs+ (126.0 mg/g). Additionally, dynamic system for cleaning cesium from polluted water was also investigated. The excellent selective removal of Cs by SCB-M-FC was escorted by the liberation of K+ and diffusion mechanisms. The SCB-Cu-FC nanocomposite was found to be appropriate for the practical removal of cesium from contaminated aqueous solution.

The Effect of High-Energy Ball Milling of Montmorillonite for Adsorptive Removal of Cesium, Strontium, and Uranium Ions from Aqueous Solution

Clay minerals are widely used to treat groundwater and surface water containing radionuclides. In our study, the method of mechanochemical activation for increasing the sorption capacity of the natural clay mineral montmorillonite was used. By adjusting the grinding time, the increasing sorption parameters of mechanochemically activated montmorillonite were determined. X-ray diffraction method, scanning electron microscopy, and the determination of the specific surface by low-temperature adsorption–desorption of nitrogen to characterize the natural and mechanochemical-activated montmorillonites were used. It was established that the maximal sorption of uranium, strontium, and cesium is found for montmorillonite after mechanochemical treatment for 2 h. It is shown that the filling of the surface of montmorillonite with ions of different natures occurs in various ways during different times of mechanochemical treatment. The appropriateness of the Langmuir and Freundlich models for the sorption parameters of uranium, strontium, and cesium ions on montmorillonite after its mechanochemical activation was established. The effect of natural organic substances—humic acids—on the efficiency of water purification from uranium on mechanoactivated montmorillonite was studied. The obtained sorbents can be effectively used for the removal of trace amounts of radionuclides of different chemical natures (uranium, cesium, and strontium) from polluted surface and ground waters.

MXene/AgNW composite material for selective and efficient removal of radioactive cesium and iodine from water

Toxic fission products, such as cesium (137Cs) and iodine (129I) are of great concern because of their long half-lives and high solubility in water. The simultaneous removal of Cs and I using a single adsorbent is an area of increasing interest. In this study, MXene/silver nanowire (AgNW) composite was synthesized through physical mixing and employed for simultaneous removal of iodide (I−) and cesium (Cs+) ions from contaminated water. The MXene/AgNW composite demonstrated excellent adsorption capacities of 84.70 and 26.22 mg/g for I− and Cs+, respectively. The experimental data supported the hypothesis of multilayer adsorption of Cs+ owing to the inter-lamellar structures and the presence of heterogeneous adsorption sites in MXene. The interaction between I− and the AgNW involved chemisorption followed by monolayer adsorption. MXene/AgNW composite material exhibited promising results in the presence of competitive ions under extreme pH conditions. Thus, synthesized composite materials holds promising potential as an adsorbent for the remediation of radioactive liquid waste.

An Evaluation of Cesium Removal from Simulated Radioactive Contaminated Soil with a Magnetized Zeolite Derived from Anthracite

The magnetized zeolite with an optimized conversion rate of 53% can be readily synthesized from industrial anthracite using a water-based method. The highly porous structure of ferromagnetism zeolite demonstrates robust magnetic properties with a magnetite content of 12–15%, satisfying adsorbent separation and recycling through magnetic cylinder rotating and vibrating separation. A cesium adsorption and removal efficiency as high as 99.92% with a corresponding adsorbent recovery ratio of up to 96.36% can be achieved for the simulated cesium-contaminated soil with a water content of 20% and a cesium content of 1% with an adsorbent-to-contaminated soil ratio of 1:2. Adsorption and magnetic separation technology with magnetized zeolite synthesized from anthracite exhibited a high cesium removal rate and zeolite recovery ratio, demonstrating promising application potential in treating radioactive waste soils and robust and economically viable engineering feasibility.

Novel adsorbent derived from sludge of paper industry for removal of cesium ion in water

Metal ion contamination has been a public concern due to its negative impact on human health and the environment. Cesium (Cs), a harmful metal ion, can cause cell damage; acute radiation syndrome includes nausea, vomiting, diarrhea, bleeding, and, in extreme cases, death. As a result, removing cesium ion from water is critical. This research aims to examine the capacity of a novel adsorbent derived from paper industry solid waste to remove cesium ion from water. The adsorption process was carried out with some variables including adsorbent dose, solution of pH, contact time, initial Cs concentration, and adsorbent form. According to characterization data, paper industry sludge contains elements such as SiO2 (28.1%), CaO (21.8%), Al2O3 (16.1%), and Fe2O3 (12%), among others. The surface area of the adsorbent is 100 m2/g and a diameter of 3.8 nm. Following equilibrium, the current study discovered that the developed adsorbent has the highest cesium removal, up to 79% for 10 mg/L of Cs initial. The novel adsorbent has high adsorption removal and may be a promising adsorbent material for metal ion removal in water.

Preparation of nano-scale ferric hexacyanoferrate using coal ash by microwave-assisted hydrothermal process for cesium removal

The removal of radioactive cesium (Cs+) has received considerable attention owing to its chemotoxicity and radiotoxicity. This study presents a method for producing ferric hexacyanoferrate nanoparticles (Prussian blue, PB), using recycled magnetic coal ash (M-CA) as an effective and selective adsorbent for Cs+ removal. A microwave-assisted hydrothermal technique was employed to recover the Fe solution from M-CA and a simple sol–gel technique was used to synthesize PB nanoparticles. The PB nanoparticles exhibited cubic cluster structures with an average size of 20.67 nm. Their Cs+ adsorption capacity reached 213.061 mg/g, significantly surpassing the capacities of absorbents reported in previous studies. Cs+ was observed to be associated with localized adsorption sites on the PB surfaces, with minimal internal diffusion. In addition, the hydrated radius of Cs+ emerged as a critical factor influencing its adsorption onto PB surfaces, enabling the efficient removal of Cs+ even in the presence of competing ions. These findings offer valuable insights for the straightforward synthesis of highly efficient and selective adsorbents for radioactive substances, as well as the recovery of valuable materials from industrial solid waste.

Zein-enhanced sodium alginate/thiostannate microsphere adsorbent Zein@SA/KBS for efficient removal of cesium from wastewater

Although efficient removal of Cs from wastewater is of great importance because of the nuclear energy sustainable development and public health, removing cesium is challenging for the high concentrations of sodium and potassium ions coexist. In this work, we synthesized the first novel bismuth-doped layered tin sulfide (KBS) and applied it to the efficient green adsorption of liquid cesium resources. KBS could reach the adsorption equilibrium for Cs+ within only 2 min with a theoretical adsorption capacity of 425.55 mg/g. Furthermore, the adsorption performance remained reliable after 10 cycles of use. The structure and properties of KBS were explained at the molecular level by DFT calculations, and the calculated results were in sound agreement with the experimental data. Meanwhile, in this study, the material was reinforced and shaped by the electrostatic interaction of Zein and sodium alginate hydrogel, and finally, Zein@SA/KBS spherical composite adsorbent was obtained. The problem of the difficult recovery of adsorbent and the secondary contamination was solved. The adsorption performance of Zein@SA/KBS on Cs+ was better than most composite adsorbents and showed reliable stability. Therefore, the new microspherical adsorbent (Zein@SA/KBS) has great potential for industrial application in removing radioactive cesium from wastewater.

Synthesis of Prussian blue-embedded magnetic micro hydrogel for scavenging of cesium from aqueous solutions; Batch and dynamic investigations

A magnetic micro porous structure composite based on alginate and Prussian blue (M-SA-PB) was simply prepared for cesium removal from the aqueous solutions. The gelation and formation of PB proceeded through the same step, which made the PB homogenously distributed and firmly attached to the alginate matrix. The homogenizer was applied to break down the bulky gel structure into micro-ones, and the lyophilizer will provide the porous structure. Batch cesium sorption experiments showed that the adsorption kinetics and isotherms were attributed to the pseudo-second-order model and Langmuir isotherm. Moreover, the Cs-ion is favorably adsorbed on the M-SA-PB composite surface as a monolayer towards Cs, with a maximum adsorption capacity reach of 191.0 mg/g. Furthermore, the M-SA-PB adsorbent showed excellent adsorption selectivity of Cs from multiple-ion solutions. Our work was extended to use the M-SA-PB composite in dynamic cesium sorption. The column studies showed that the removal efficiency of Cs+ increased with increasing bed depth as well as the initial cesium concentration. Finally, as previously mentioned, the M-SA-PB could be considered an excellent Cs+ scavenger employing both batch and dynamic approaches, which makes it a promising adsorbent for practical investigations.

Investigation into Na and Cs activity coefficients in high salt solutions to support Cs removal in Hanford tank waste

Abstract The treatment of Hanford tank waste is one of the most technically challenging environmental cleanup activities for the U.S. Department of Energy to date. To expedite the processing of liquid waste stored in underground tanks in southeastern Washington state, it is necessary to remove the significant dose contributor, 137Cs. Toward this effort, ion exchange with crystalline silicotitanate (CST) has been employed as part of the Tank Side Cesium Removal system. The model used to predict Cs exchange onto CST was developed using activity coefficients calculated from the Bromley equation. A series of batch contact tests that varied in [Na] were conducted to look at the impact of Na concentration on Cs distribution. Experimental distribution ratios (K d) were compared to the distribution ratios predicted using three different activity coefficient models: (1) commercially available HSC software, (2) the Bromley equation, and (3) a simplified approach adapted from Marcos-Arroyo et al. Ultimately, the Bromley method underpredicted the effect of ionic strength on the Na activity coefficient (γ Na+), HSC overestimated the impact of ionic strength on the expected performance due to the Cs activity coefficient (γ Cs+), but the simplified approach predicted the experimental K d values quite well in a binary matrix. Expansion of this approach in complex matrices is necessary for application to Hanford tank waste.

Fabrication of 3D-printed PLA filter with immobilized Prussian blue for aqueous cesium removal

This study explores a method to immobilize Prussian blue (PB) on a 3D-printed filter made of polylactic acid (PLA) to selectively remove cesium (Cs) ions from water. A pristine 3D-printed filter made of PLAwas prepared by the fused deposition modeling (FDM) based 3D printer. The surface of the pristine PLA filter was activated through a hydrolysis reaction (in sodium hydroxide solution; PLA-OH) and grafting polymerization of acrylic acid (PLA-OH/AA) to introduce hydrophilic functional groups on the PLA filter surface. This surface modification process, believed to be beneficial for forming stable PB particles, was analyzed using various characterization methods, such as Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. Furthermore, PB was immobilized in the presence of the surface-modified filter (PLA-OH54/AA), and its Cs adsorption behavior was investigated. The maximum adsorption capacity (qm) obtained using the Langmuir isotherm model was 3.67mg/g, and the adsorption kinetic was well interpreted by the pseudo-second-order model. Moreover, the column test results indicated the effective continuous Cs removal by the prepared PB-immobilized 3D filter (PLA-OH54/AA-PB). The potential of the prepared PLA-OH54/AA-PB filter as a 3D filter-type adsorbent for decontaminating radioactive Cs was demonstrated herein.

Tuning Surface Energy to Enhance MoS2 Nanosheet Production via Liquid-Phase Exfoliation: Understanding the Electrochemical Adsorption of Cesium Chloride.

Environmental pollution caused by radionuclides like Cs-137 and Cs-134 has increased global attention toward public health. Electrochemical adsorption has emerged as a feasible, rapid, and scalable method to treat contaminated water sources. However, graphene and its derivatives have limitations in ion adsorption via physisorption, forming a double layer that restricts the electrode's adsorption capacity. To address this, we propose the use of molybdenum disulfide (MoS2) with its extensive intercalation galleries of MoS2 nanosheets for cesium removal via an electrochemical route. Liquid-phase exfoliation with water and N-methyl-2-pyrrolidone (NMP) was then used to produce MoS2 nanosheets in a scalable quantity (high-yield production). The formation of a mixed solvent possessing relatively equivalent surface energy for exfoliation enabled us to achieve a remarkable exfoliation yield of up to ca. 1.26 mg mL-1, which is one of the highest yields reported to date (without a surfactant being added) and to the best of our knowledge. The 35% v/v of water in NMP displayed a maximum yield while maintaining the structure of the as-exfoliated one. Water exceeding over 66.7% v/v led to the formation of MoO3. Moreover, an insight into the cesium ion removal mechanism through the electrochemical route was demonstrated. It is found that the Cs+ removal follows electrochemical intercalation rather than adsorption. This work aids the understanding of cesium intercalation coupled with a mass-scale production method, which should lead to more efficient and cost-effective removal of radionuclides from contaminated water sources, opening new research avenues in materials and environmental science.

Significantly enhanced alkaline stability and cyanide suppression of Prussian blue analogues using montmorillonite for high-performance cesium removal

Radiocesium (Cs+) treatment is getting more attention as Japan plans to dump wastewater from Fukushima nuclear meltdown into the Pacific Ocean. Prussian blue is a star material and medicine for intracellular and extracellular therapy of Cs+. However, it and its analogues are essentially unstable in alkali-solution and seawater due to break down easily into the hazardous cyanide substance. In this study, copper ferrocyanide/magnetic montmorillonite composites (KCuFC/M−MT) were prepared using an in-situ synthetic method. This method can inhibit the decomposition of Prussian blue analogues (PBAs) and the production of toxic cyanide. The 5KCuFC/M−MT composites exhibit excellent Cs+ adsorption properties (204.48 mg/g), good material chemical stable over a wide pH region (2 ≤ pH ≤ 12), safe amount of cyanide release (<0.2 mg/L, EPA, USA), and low-toxic to human hepatocytes (HepG2 cells), which are promising for the application in radioactive wastewater treatment. The adsorption mechanism and stabilization mechanism were systematically studied. This study provides a reference for the control radioactive Cs+ hazards by using clay material stabilized ferrocyanide material and provides a new direction for the research of cesium-control materials. This research solves the problem of basic instability of PBAs and expands new application fields for PBAs, especially decorporation agent for internal contamination by radiocesium.

Effective removal of cesium by ammonium molybdophosphate–polyethylene glycol magnetic nanoparticles

This study synthesizes a new adsorbent composite for the removal of Cs ions from waste effluents. The adsorbent is composed of polyethylene glycol-decorated ammonium molybdophosphate magnetic Fe3O4 nanoparticles (PEG–AMP MNs) and is prepared via coprecipitation by grafting ammonium phosphomolybdate onto the surface of Fe3O4 and coprecipitation with polyethylene glycol. The physical and chemical structure of the PEG–AMP MNs was investigated using various spectroscopic and analytical techniques, revealing that Fe3O4 was tightly bound to the AMP particles and that the composites exhibited superparamagnetic behavior. The Cs+ adsorption behavior of the adsorbent was investigated in a wide range of pH values and temperatures, using multiple Cs+ contact times and initial Cs+ concentration, and with interference from additional ionic species. The adsorbent achieved 99.8% removal of Cs+ in the solution pH range of 1–12 and maintained its stability after adsorption. Interfering ions had little effect on the amount of Cs+ adsorbed. The experimental data were fitted using Langmuir, Freundlich, Redlich-Peterson and Sips isotherms pseudo-first-order and pseudo-second-order kinetic models. The results showed that the adsorption data fitted well with pseudo-second-order kinetics and the Langmuir isotherm model, with a maximum adsorption capacity of 53.89 mg g−1 and equilibrium reached within 20 min. Thermodynamic experiments showed the adsorption process to be inherently endothermic. The mechanism of Cs+ adsorption by PEG–AMP MNs is proposed to primarily be a combination of weak electrostatic attraction and ion exchange between NH4+ and Cs+. More importantly, the encapsulation of a magnetic carrier allows for the efficient separation and recovery of Cs+ after adsorption.

In situ growth of metal hexacyanoferrate crystals on alginate beads for effective removal of radioactive cesium (137Cs) from seawater

Metal hexacyanoferrates (Me-HCFs) are highly effective materials for removing radioactive Cs (137Cs) in seawater. For their practical application, granulation of Me-HCFs is necessary. However, conventional granulation techniques using a polymer as a binding material adversely affect the adsorption performance of Me-HCFs by blocking their adsorption sites. In the present work, to minimize the interference of the binding material, Me-HCF crystals were synthesized on an alginate bead surface in situ for the treatment of 137Cs+-contaminated seawater. Three different Me-HCFs immobilized on alginate beads (Fe-HCF, Cu-HCF, and Co-HCF) were prepared via a simple and rapid method involving a reaction between ionophorically crosslinked alginate beads (Fe3+, Cu2+, and Co2+ ions) and HCF solution. Among them, Fe-HCF crystals were successfully grown on the alginate bead surface; the other crystals were hardly synthesized despite a longer reaction time. The Fe-HCF crystals composed 15.0 % (w/w) of the beads and were located on the surface of the beads rather than being embedded in the alginate matrix. Because the Fe-HCF crystals were located at the surface of the alginate beads, Cs+ adsorption onto the Fe-HCF crystals showed fast reaction kinetics (achieving equilibrium in ∼ 3 h) and a high Cs+ adsorption capacity (∼33.5 mg/g). Also, a feasibility test was carried out for the removal of radioactive 137Cs+ in real seawater medium. Finally, a continuous Cs+ removal test was conducted in a packed column of the Fe-HCF beads. It was able to treat 65 bed volume of 50 mg/L of Cs+ solution with a flow rate of 1 mL/min.

Fabrication of self-assembled Prussian blue graphene hydrogel for highly selective removal of radioactive cesium in water: Adsorption study

This paper reports a simple and cost-effective method for fabrication of a 3D porous and redox-active Prussian blue-graphene (PBG) hydrogel using ferrous ions to reduce graphene oxide sheets. The hydrogel was obtained via sonication for 5 min only at a low temperature of 40 °C without the need of purification or centrifugation. The hydrogel exhibited high selectivity for cesium ions due to the cubic framework of iron centers bound by cyanide bridges, which allows for intercalation of additional cations. The hydrogel's centered-cubic phase of Prussian blue was confirmed through XRD, and its existence was demonstrated through FTIR and XPS. The BET surface area measurements revealed that the composite's adsorptive surface area increased as compared to magnetic PBGO. Furthermore, the hydrogel's adsorption potential for cesium ions increased to 4.67 mmol/g (621.11 mg/g) compared to the previous work, fitting well with the Langmuir isotherm and the pseudo-second order kinetic model. Moreover the optimal values for temperature and pH for cesium ions removal were found to be 30 °C and neutral, respectively.

Selective removal of cesium by magnetic biochar functionalized with Prussian blue in aqueous solution

Selective removal of cesium by magnetic biochar functionalized with Prussian blue in aqueous solution

Removal of cesium from contaminated soils using EDTA-Na and DTPAchelating agents

Removal of cesium from contaminated soils using EDTA-Na and DTPAchelating agents

Development of a potassium-based soil washing solution using response surface methodology for efficient removal of cesium contamination in soil

The overuse of chelating soil washing agents for removal of heavy metal can release soil nutrients and negatively affect organisms. Therefore, developing novel washing agents that can overcome these shortcomings is necessary. In this study, we tested potassium as a main solute of novel washing agent for cesium-contaminated field soil, owing to the physicochemical similarities between potassium and cesium. Response surface methodology was combined with a four-factor, three-level Box–Behnken design to determine the superlative washing conditions of the potassium-based solution for the removal of cesium from the soil. The parameters that were considered were the following: potassium concentration, liquid-to-soil ratio, washing time, and pH. Twenty-seven sets of experiments were conducted using the Box–Behnken design, and a second-order polynomial regression equation model was obtained from the results. Analysis of variance proved the significance and goodness of fit of the derived model. Three-dimensional response surface plots displayed the results of each parameter and their reciprocal interactions. The washing conditions that achieved the highest cesium removal efficiency (81.3%) in field soil contaminated at 1.47 mg/kg were determined to be the following: a potassium concentration of 1 M, a liquid-to-soil ratio of 20, washing time of 2 h, and a pH of 2.