Uranium Concentration In Seawater Research Articles

Constructing Ce–OH groups on CeO2 for enhancing removal and recovery of uranium from wastewater and seawater

Efficient recovery of uranium from wastewater and seawater provides an important guarantee for the sustainable growth of nuclear energy. Herein, we skillfully use the alkali etching method to construct CeO2 hollow spheres rich in Ce–OH groups for the removal and recovery of uranium from water matrixes. It is found that the CeO2 exhibits fast adsorption kinetics (equilibrium time within 10 min) and moderate adsorption capacity (143.1 mg/g), and the removal efficiency of low concentration uranium (0.1 g/L and 1 g/L) reaches 100% within 1 min of adsorption. Moreover, the adsorption of uranium by CeO2 is almost unaffected by common anions and cations in the environment, even if the concentration of anions is 1000 times that of uranium. More importantly, the CeO2 can enrich uranium concentration in seawater by 167.9 times and the recovery rate reaches 83.9%. Mechanistic studies reveal that the adsorption of uranium by CeO2 is mainly attributed to the rich Ce–OH groups on the surface of CeO2, resulting in the rapid adsorption of U(VI) and mainly forms a single-bridge model. The findings of this study provide a green and efficient path for the removal and recovery of uranium from wastewater and seawater.

Preparation of double network antibacterial hydrogel modified by hydroxamic acid gelatin/polyacrylamide and high efficiency uranium extraction from seawater

Uranium extracted from seawater can solve the problem of the shortage of uranium on land and provide potential resources for the nuclear power industry. However, the high salinity and low uranium concentration in seawater, coupled with the presence of competing ions and bacteria, pose significant challenges to this technology. In this study, a hydroxyl oxime acid modified gelatin/polyacrylamide double network (Gel/PAM(DN)-HA) hydrogel developed for efficient uranium extraction from seawater. The adsorption capacity of Gel/PAM(DN)-HA hydrogel for uranium in 15 ppm uranium solution was as high as 397.04 mg-U/g-Ads, with a reuse rate of 78.46 % ± 5.84 % after 5 cycles of adsorption-desorption. Gel/PAM(DN)-HA was immersed in natural seawater for 24 days to evaluate its adsorption capacity. Gel/PAM(DN)-HA demonstrated an impressive uranium extraction capacity of 4.801 mg·g−1. Antibacterial experiments demonstrated that Gel/PAM(DN)-HA can effectively inhibit the Escherichia coli (E. coli ATCC25922) and Staphylococcus aureus (S. aureus ATCC6538). The results highlight the adsorbent's significant potential for extensive utilization in extracting uranium from seawater.

Adsorbents for the Uranium Capture from Seawater for a Clean Energy Source and Environmental Safety: A Review.

On the global level, uranium is considered the main nuclear energy source, and its removal from terrestrial ores is enough to last until the end of the current century. Therefore, a major focus is attracted toward the capture of uranium from a sustainable source (seawater). Uranium recovery from seawater has been reported over the last few decades, and recently many efforts have been devoted to the preparation of such adsorbents with higher selectivity and adsorption capacity. The purpose of this review is to report the advancement in adsorbent preparation and modification of porous materials. It also discusses challenges such as adsorbent selectivity, low uranium concentration in seawater, contact time, biofouling, and the solution to the problems necessary to ensure a better adsorption performance of the adsorbent.

Graphene oxide based ion-imprinted polymers for selective uranium adsorption from seawater

The project for the uranium adsorption from seawater provides a new idea for acquisition of uranium resources. However, the low concentration of uranium in seawater, the presence of multiple metal ions, and the attachment of microorganisms all affect the adsorption of uranium by the material. To solve these problems, graphene oxide (GO)-based uranium imprinted polymers with antibacterial properties and specific selectivity for uranium were prepared. β-1,3 glucan was selected as the functional monomer for grafting GO, followed by the imprinting process with uranyl ions as the target template. After elution of the target ions by hydrochloric acid, the ion-imprinted polymer was prepared (GOG-RE). The results of ion-competition adsorption experiments showed that the imprinted material had a high adsorption selectivity for uranyl ions, the Kd value of 1.28 × 105 mL∙g−1. The calculated maximum adsorption capacity was 806.45 mg·g−1. Antibacterial experiments have proven its significant inhibitory effect on E. coli (Gram-negative), S. Aureus (Gram-positive) and Pseudoalteromonas marina. The above results indicate that GOG-RE has excellent application prospects in the field of uranium adsorption from seawater.

Functionalized GO-doped double network antibacterial hydrogels for efficient uranium extraction from seawater

Uranium extraction from seawater provides the new idea for the development of uranium resources. However, the concentration of uranium in seawater is extremely low (∼3.3 μg/L). Meanwhile, there are a large number of competing ions and microorganisms in the seawater. It is a huge challenge to extract uranium from seawater. In this paper, a double network hydrogels material with effective antifouling ability was prepared for highly efficient uranium sorption. First, poly(hexamethylene biguanide) hydrochloride (PHMB) modified graphene oxide(GO) was prepared (PHMB-GO), and then PHMB-GO was doped into the double network hydrogels structure formed by acrylamide and gelatin in order to obtain (GO-PHMB)0.4@Gelatin-PAM, which showed the maximum uranium adsorption capacity reached 625.00 mg∙g−1. More importantly, it exhibited excellent selectivity towards uranium(VI) in the presence of multiple coexisting metal ions in simulated seawater. The Kd value for uranium is 1.73 × 104 mL∙g−1, which is far more than other metal ions. The antibacterial and antialgae experiments prove that the adsorption material has a good inhibitory effect on Escherichia coli (E. coli), vibrio vulnificus (V vulnificus) and Staphylococcus aureus (S. aureus). Therefore, (GO-PHMB)0.4@Gelatin-PAM is an outstanding candidate for efficient uranium extraction from seawater.

Waste feather fiber based high extraction capacity bio-adsorbent for sustainable uranium extraction from seawater

Recycling uranium from seawater is of great significance to the development of nuclear industry. However, due to high salinity and low uranium concentration in seawater, there are still many challenges in current seawater uranium extraction technology. In this study, waste feather fibers (FF) were used as raw materials to develop a phosphonate-functionalized feather fiber (FF-PT). The study on the adsorption performance shows that FF-PT have good adsorption and recycling performance for uranium. The study on the adsorption performance shows that FF-PT have good adsorption and recycling performance for uranium. The adsorption capacity reaches up to 342.5 mg·g−1 in the 8 ppm uranium solution, and service life of at least 10 cycles were obtained. In addition, in the environment with high salinity and the coexistence of metal competitive ions, FF-PT also shows excellent selectivity, and it can reach 3.22 mg·g−1 adsorption capacity after immersed in natural seawater for 30 days. Combined with the results of economic analysis, we believe that the FF-PT has broad application prospects in the industrialized uranium extraction from seawater.

Functionalized Iron–Nitrogen–Carbon Electrocatalyst Provides a Reversible Electron Transfer Platform for Efficient Uranium Extraction from Seawater

Uranium extraction from seawater provides an opportunity for sustainable fuel supply to nuclear power plants. Herein, an adsorption-electrocatalysis strategy is demonstrated for efficient uranium extraction from seawater using a functionalized iron-nitrogen-carbon (Fe-Nx -C-R) catalyst, comprising N-doped carbon capsules supporting FeNx single-atom sites and surface chelating amidoxime groups (R). The amidoxime groups bring hydrophilicity to the adsorbent and offer surface-specific binding sites for UO2 2+ capture. The site-isolated FeNx centres reduce adsorbed UO2 2+ to UO2 + . Subsequently, through electrochemical reduction of the FeNx sites, unstable U(V) ions are reoxidized to U(VI) in the presence of Na+ resulting in the generation of solid Na2 O(UO3 ·H2 O)x , which can easily be collected. Fe-Nx -C-R reduced the uranium concentration in seawater from ≈3.5 ppb to below 0.5 ppb with a calculated capacity of ≈1.2 mg g-1 within 24 h. To the best of the knowledge, the developed system is the first to use the adsorption of uranyl ions and electrodeposition of solid Na2 O(UO3 .H2 O)x for the extraction of uranium from seawater. The important discoveries guide technology development for the efficient extraction of uranium from seawater.

Catalyst: Challenges in development of adsorbents for recovery of uranium from seawater

Sheng Dai is currently a section head of separations and polymer chemistry and a UT-Battelle Corporate Fellow at the Chemical Sciences Division of the Oak Ridge National Laboratory and a professor of chemistry at the University of Tennessee, Knoxville. He served as a national technical director for a US Department of Energy project aimed at recovering uranium from seawater (2010–2016). His current research interests include ionic liquids, porous materials, and their applications for separation sciences and energy storage, as well as catalysis by nanomaterials.

Reaction: Goal-Oriented PAF Design for Uranium Extraction from Seawater

Guangshan Zhu received his BSc (1993) and PhD (1998) degrees in chemistry from Jilin University. He is now a full professor at Northeast Normal University. Driven by the demands in sustainable energy and environments, his current research interest focuses on the design and synthesis of porous aromatic frameworks for gas adsorption, separation, and uranium capture.

Uranium Resource Recovery from Desalination Plant Feed and Reject Water Using Amidoxime Functionalized Adsorbent

With global demand for nuclear power expected to rise, new nuclear fuel resources must be explored to ensure the viability and sustainability of nuclear power. Uranium recovery from seawater is one potential source, though the low concentration of uranium in seawater is a significant obstacle. As a concentrate of seawater, desalination brine reject would have a significantly higher uranyl concentration. In this work, the adsorption of uranium and competing ions in brine reject is investigated. Adsorption experiments were performed over 84 days in 5-gallon batch tanks with amidoxime adsorbents and samples taken from the feed seawater and reverse osmosis brine reject of the Tampa Bay Desalination Plant. The aqueous concentration and adsorbed mass of uranium, zinc, copper, iron, vanadium, calcium, and magnesium were determined through inductively coupled plasma mass spectroscopy. Aqueous adsorption modeling was used to simulate speciation and adsorption of these ions under the experimental conditions. The ad...

Extraction of uranium from seawater: a few facts

Although uranium concentration in seawater is only about 3 micrograms per liter, the quantity of uranium dissolved in the world's oceans is estimated to amount to 4.5 billion tonnes of uranium metal (tU). In contrast, the current conventional terrestrial resource is estimated to amount to about 17 million tU. However, for a number of reasons the extraction of significant amounts of uranium from seawater remains today more a dream than a reality. Firstly, pumping the seawater to extract this uranium would need more energy than what could be produced with the recuperated uranium. Then if trying to use existing industrial flow rates, as for example on a nuclear power plant, it appears that the annual possible quantity remains very low. In fact huge quantities of water must be treated. To produce the annual world uranium consumption (around 65,000 tU), it would need at least to extract all uranium of 2 × 1013 tonnes of seawater, the volume equivalent of the entire North Sea. In fact only the great ocean currents are providing without pumping these huge quantities, and the idea is to try to extract even very partially this uranium. For example Japan, which used before the Fukushima accident about 8,000 tU by year, sees about 5.2 million tU passing every year, in the ocean current Kuro Shio in which it lies. A lot of research works have been published on the studies of adsorbents immersed in these currents. Then, after submersion, these adsorbents are chemically treated to recuperate the uranium. Final quantities remain very low in comparison of the complex and costly operations to be done in sea. One kilogram of adsorbent, after one month of submersion, yields about 2 g of uranium and the adsorbent can only be used six times due to decreasing efficiency. The industrial extrapolation exercise made for the extraction of 1,200 tU/year give with these values a very costly installation installed on more than 1000 km2 of sea with a lot of boats for transportation and maintenance. The ecological management of this huge installation would present significant challenges. This research will continue to try to increase the efficiency of these adsorbents, but it is clear that it would be very risky today, to have a long-term industrial strategy based on significant production of uranium from seawater with an affordable cost.

Long-Term Energy Solutions: The Truth Behind the Silent Lie

Paul Weisz’s article on long-term energy supplies (Physics Today, Physics Today 0031-9228 57 7 2004 47 https://doi.org/10.1063/1.1784302. July 2004, page 47 ) states that uranium resources with breeder reactors could provide the world’s energy needs for “hundreds of years.” That is a gross underestimate. The world’s energy needs could be provided by uranium-fueled breeder reactors for the full billion years that life on Earth will be sustainable, without the price of electricity increasing by more than a small fraction of 1% due to raw fuel costs. 1 1. B. L. Cohen, Am. J. Phys. 51, 75 (1983). The error in Weisz’s calculation is that he is referring to uranium available at its present price, $10–20 per pound. But in breeder reactors, 100 times as much energy is derived from a pound of uranium as in present-day light water reactors, so we could afford to use uranium that is 100 times as expensive.The cost of extracting uranium from its most plentiful source, seawater, is about $250 per pound—the energy equivalent of gasoline at 0.13 cent per gallon! The uranium now in the oceans could provide the world’s current electricity usage for 7 million years. But seawater uranium levels are constantly being replenished, by rivers that carry uranium dissolved out of rock, at a rate sufficient to provide 20 times the world’s current total electricity usage. In view of the geological cycles of erosion, subduction, and land uplift, this process could continue for a billion years with no appreciable reduction of the uranium concentration in seawater and hence no increase in extraction costs.REFERENCESection:ChooseTop of pageREFERENCE <<1. B. L. Cohen, Am. J. Phys. 51, 75 (1983). Google ScholarCrossref© 2004 American Institute of Physics.

Applicability of synergistic adsorption in electroanalysis of dissolved uranium in seawater

Abstract A synergistic adsorption effect is used for the electrochemical determination of dissolved uranium concentration in seawater and estuarine waters. The ligand pairs salicylic acid-tributylphosphate (tributylphosphine oxide), 2-thenoyltrifluoroacetone (TTA)-TBP (TBPO), and acetylacetone-TBP have been experimentally tested. The measurements were performed by cathodic-stripping electrochemical techniques (normal pulse and linear-sweep voltammetry). Detection limits for uranium in 0.55 M NaCl after cathodic accumulation were found to be about 10 −10 M with the TTA-TBP pair and about 10 −9 M with the salicylic acid-TBP combination of ligands. The dissolved uranium concentrations in water samples from the Adriatic sea and estuaries of Krka and Rasa river were found to lie between 0.7 and 4.0 × 10 −8 M.

Chelating Polymers for Recovery of Uranium from Seawater∗

Abstract Despite the low concentration of uranium in seawater (3.3 ppb), a special emphasis has been placed on its recovery. Although the concentration is low, it has been estimated that the world's oceans contain about 4 × 109 tons of uranium—theoretically an unlimited supply of nuclear fuel. Adsorption has been considered to be a technically feasible procedure for a uranium recovery process with regard to economic and environmental impacts. The present paper restricts its coverage to those applications using chelating polymeric resins containing amidoxime groups as the most promising adsorbent.

Concentration of Uranium in Seawater by Flotation

Concentration of Uranium in Seawater by Flotation

The extraction of uranium from seawater by poly(amidoxime)/poly(hydroxamic acid) resins and fibre

The uranium concentration in seawater is 3 μg/l with an estimated 5 × 10 9 tonnes of uranium in the oceans, in solution as the tricarbonato complex. Any extraction process will encounter the problems attendant on this high dilution, the only feasible methods currently being ion exchange on chelating resins or sorption onto inorganic materials. Poly(amidoxime)/poly(hydroxamic acid) chelating resin has been produced with high uranium sorption from neutral solutions containing the metal as the tricarbonato complex, and the results of a study of the behaviour of this resin towards seawater are given. High chemical and biochemical stability and fast sorption kinetics are properties of the resin which can sorb 68 per cent of the uranium present using a 24 s resin to seawater contact time. Poly(amidoxime)/poly(hydroxamic acid) fibre, prepared by the oximation of poly(acrylonitrile) fibre, is able to sorb 12.5 per cent of uranium in seawater with a 2 s contact time and has the advantage of being in a form capable of weaving into a chelating cloth. Sorbing 1.8 mg uranium per gramme fibre per 10 days, the cloth can be produced as an endless belt, for a continuous process for uranium extraction. A theoretical model indicates that uranium production could be possible at 6 tonnes per annum.

540. 海水中のウランの採取,(VI)

(1) The adsorbing capacity for uranium shown by titanic acid prepared in homogeneous and acidic solution was found larger than titanic acid prepared in nonhomogeneous and neutral solution. The uranium adsorbed on titanic acid increased with rising temperature of sea-water. The adsorption reached equilibrium within 2 days. The concentration of uranium in the titanic acid was found experimentally to have a maximum value of U/Ti=1, 500μg/g.(2) The concentration of uranium adsorbed on the titanic acid at a given temperature was determined by the amount of sea-water and the concentration of uranium in seawater on the same titanic acid. An empirical formula was obtained for this relationship; the adsorption was applied to Freundlich's isotherm, and the distribution coefficients were found nearly constant within the range of sea-water volume covered by the present experiment.(3) The adsorption capacity was estimated from the term of multiplication of the distribution coefficient and the concentration of uranium in sea-water. The maximum value evaluated was U/Ti=4, 200μg/g, with the titanic acid prepared by hydrolysis.(4) The uranium adsorbed on the titanic acid increased with rising temperature of the sea-water, the empirical relationship being c=k exp (αtt2), (c: concn. of U, t: temp., k and α: const.).