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Seko, Noriaki; Tamada, Masao; Kasai, Noboru; Yoshii, Fumio; Simizu, Takao

doi:10.2208/prooe.20.611

Cited by 11 publications

(5 citation statements)

References 3 publications

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“…The ability to consistently reproduce a homogeneous adsorbent provides confidence that a robust production process has been developed. Inconsistent uranium adsorption performance in different portion of fibrous feathers was reported in JAEA’s braided adsorbent materials . (2) use of 40–100 mg of fibrous adsorbent in a flow-through column exposure can be reliably scaled up to flume exposures with several grams (5–10 g) of braided adsorbent deployed in a more open exposure, closer to a real world marine exposure (i.e., adsorbent is freely suspended in seawater).…”

Section: Resultsmentioning

confidence: 99%

“…Amidoxime-based polymeric adsorbents are among the most widely described and considered the most promising materials to extract uranium from seawater . Japanese scientists introduced the use of braided-type amidoxime-based polymeric adsorbents for passive harvesting of oceanic uranium. , Polymeric adsorbents have advantages including good mechanical strength, the ability to be produced in large quantity, and easy handling (lightweight)/deployment in the ocean. , …”

Section: Introductionmentioning

confidence: 99%

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Characterization and Testing of Amidoxime-Based Adsorbent Materials to Extract Uranium from Natural Seawater

Kuo

Janke

Wood

et al. 2015

Ind. Eng. Chem. Res.

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Extraction of uranium (U) from seawater for use as a nuclear fuel is a significant challenge due to the low concentration of U in seawater (∼3.3 ppb) and difficulties to selectively extract U from the background of major and trace elements in seawater. The Pacific Northwest National Laboratory (PNNL)’s Marine Sciences Laboratory (MSL) has been serving as a marine test site for determining performance characteristics (adsorption capacity, adsorption kinetics, and selectivity) of novel amidoxime-based polymeric adsorbents developed at Oak Ridge National Laboratory (ORNL) under natural seawater exposure conditions. This manuscript describes the performance of three formulations (38H, AF1, AI8) of amidoxime-based polymeric adsorbents produced at ORNL in MSL’s ambient seawater testing facility. The adsorbents were produced in two forms, fibrous material (40–100 mg samples) and braided material (5–10 g samples), and exposed to natural seawater using flow-through columns and recirculating flumes. All three formulations demonstrated high 56 day uranium adsorption capacity (>3 g U/kg adsorbent). The AF1 formulation had the best uranium adsorption performance, with a 56 day capacity of 3.9 g U/kg adsorbent, a saturation capacity of 5.4 g U/kg adsorbent, and ∼25 days half-saturation time. The two exposure methods, flow-through columns and flumes, were demonstrated to produce similar performance results, providing confidence that the test methods were reliable, that scaling up from 10’s of mg quantities of exposure in flow-through columns to gram quantities in flumes produced similar results, and confirm that the manufacturing process produces a homogeneous adsorbent. Adsorption kinetics appear to be element specific, with half-saturation times ranging from minutes for the major cations in seawater, to 8–10 weeks for V and Fe. Reducing the exposure time provides a potential pathway to improve the adsorption capacity of U by reducing the V/U ratio on the adsorbent.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Characterization and Testing of Amidoxime-Based Adsorbent Materials to Extract Uranium from Natural Seawater

Kuo

Janke

Wood

et al. 2015

Ind. Eng. Chem. Res.

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“…Attaching a float to the top of the sorbent braid allowed their suspension in seawater, and upon wireless release from the anchor, facilitated their recovery with a fishing boat. After 30 days of soaking, the polymer fiber recovered 1.5 mg uranium g –1 adsorbent Figure displays the proposed deployment system for the braided adsorbent …”

Section: Brief History Of the Recovery Of Seawater Uraniummentioning

confidence: 99%

Materials for the Recovery of Uranium from Seawater

et al. 2017

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More than 1000× uranium exists in the oceans than exists in terrestrial ores. With nuclear power generation expected to increase over the coming decades, access to this unconventional reserve is a matter of energy security. With origins in the mid-1950s, materials have been developed for the selective recovery of seawater uranium for more than six decades, with a renewed interest in particular since 2010. This review comprehensively surveys materials developed from 2000-2016 for recovery of seawater uranium, in particular including recent developments in inorganic materials; polymer adsorbents and related research pertaining to amidoxime; and nanostructured materials such as metal-organic frameworks, porous-organic polymers, and mesoporous carbons. Challenges of performing reliable and reproducible uranium adsorption studies are also discussed, as well as the standardization of parameters necessary to ensure valid comparisons between different adsorbents.

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“…However, because of modest U sorption capacities and issues with deployment scalability, such materials were replaced by organofunctionalized chelating resins and polymeric sorbents. Inspired by a braided polymer sorbent developed by a Japanese team, − the current state-of-the-art material is an amidoxime copolymer prepared by radical polymerization from a high-surface-area polyethylene trunk material. − These sorbents leverage the proven U-binding affinity of the amidoxime moiety − with the robustness of a braided polymer backbone, affording a great number of uranyl binding sites due to large degrees of grafting of high-surface-area supports.…”

Section: Introductionmentioning

confidence: 99%

Successful Coupling of a Bis-Amidoxime Uranophile with a Hydrophilic Backbone for Selective Uranium Sequestration

Piechowicz

Abney

Thacker

et al. 2017

ACS Appl. Mater. Interfaces

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The amidoxime group (-RNHNOH) has long been used to extract uranium from seawater on account of its high affinity toward uranium. The development of tunable sorbent materials for uranium sequestration remains a research priority as well as a significant challenge. Herein, we report the design, synthesis, and uranium sorption properties of bis-amidoxime-functionalized polymeric materials (BAP 1-3). Bifunctional amidoxime monomers were copolymerized with an acrylamide cross-linker to obtain bis-amidoxime incorporation as high as 2 mmol g after five synthetic steps. The resulting sorbents were able to uptake nearly 600 mg of uranium per gram of polymer after 37 days of contact with a seawater simulant containing 8 ppm uranium. Moreover, the polymeric materials exhibited low vanadium uptake with a maximum capacity of 128 mg of vanadium per gram of polymer. This computationally predicted and experimentally realized selectivity of uranium over vanadium, nearly 5 to 1 w/w, is one of the highest reported to date and represents an advancement in the rational design of sorbent materials with high uptake capacity and selectivity.

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Cited by 11 publications

References 3 publications

Characterization and Testing of Amidoxime-Based Adsorbent Materials to Extract Uranium from Natural Seawater

Characterization and Testing of Amidoxime-Based Adsorbent Materials to Extract Uranium from Natural Seawater

Materials for the Recovery of Uranium from Seawater

Successful Coupling of a Bis-Amidoxime Uranophile with a Hydrophilic Backbone for Selective Uranium Sequestration

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