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Sample records for selective separation uranium

  1. SELECTIVE SEPARATION OF URANIUM FROM FERRITIC STAINLESS STEELS

    DOEpatents

    Beaver, R.J.; Cherubini, J.H.

    1963-05-14

    A process is described for separating uranium from a nuclear fuel element comprising a uranium-containing core and a ferritic stainless steel clad by heating said element in a non-carburizing atmosphere at a temperature in the range 850-1050 un. Concent 85% C, rapidly cooling the heated element through the temperature range 815 un. Concent 85% to 650 EC to avoid annealing said steel, and then contacting the cooled element with an aqueous solution of nitric acid to selectively dissolve the uranium. (AEC)

  2. SELECTIVE SEPARATION OF URANIUM FROM THORIUM, PROTACTINIUM AND FISSION PRODUCTS BY PEROXIDE DISSOLUTION METHOD

    DOEpatents

    Seaborg, G.T.; Gofman, J.W.; Stoughton, R.W.

    1959-08-18

    A method is described for separating U/sup 233/ from thorium and fission products. The separation is effected by forming a thorium-nitric acid solution of about 3 pH, adding hydrogen peroxide to precipitate uranium and thorium peroxide, treating the peroxides with sodium hydroxide to selectively precipitate the uranium peroxide, and reacting the separated solution with nitric acid to re- precipitate the uranium peroxide.

  3. URANIUM SEPARATION PROCESS

    DOEpatents

    Lyon, W.L.

    1962-04-17

    A method of separating uranium oxides from PuO/sub 2/, ThO/sub 2/, and other actinide oxides is described. The oxide mixture is suspended in a fused salt melt and a chlorinating agent such as chlorine gas or phosgene is sparged through the suspension. Uranium oxides are selectively chlorinated and dissolve in the melt, which may then be filtered to remove the unchlorinated oxides of the other actinides. (AEC)

  4. URANIUM SEPARATION PROCESS

    DOEpatents

    Hyde, E.K.; Katzin, L.I.; Wolf, M.J.

    1959-07-14

    The separation of uranium from a mixture of uranium and thorium by organic solvent extraction from an aqueous solution is described. The uranium is separrted from an aqueous mixture of uranium and thorium nitrates 3 N in nitric acid and containing salting out agents such as ammonium nitrate, so as to bring ihe total nitrate ion concentration to a maximum of about 8 N by contacting the mixture with an immiscible aliphatic oxygen containing organic solvent such as diethyl carbinol, hexone, n-amyl acetate and the like. The uranium values may be recovered from the organic phase by back extraction with water.

  5. SEPARATION OF THORIUM FROM URANIUM

    DOEpatents

    Bane, R.W.

    1959-09-01

    A description is given for the separation of thorium from uranium by forming an aqueous acidic solution containing ionic species of thorium, uranyl uranium, and hydroxylamine, flowing the solution through a column containing the phenol-formaldehyde type cation exchange resin to selectively adsorb substantially all the thorium values and a portion of the uranium values, flowing a dilute solution of hydrochloric acid through the column to desorb the uranium values, and then flowing a dilute aqueous acidic solution containing an ion, such as bisulfate, which has a complexing effect upon thortum through the column to desorb substantially all of the thorium.

  6. METHOD OF SEPARATING URANIUM SUSPENSIONS

    DOEpatents

    Wigner, E.P.; McAdams, W.A.

    1958-08-26

    A process is presented for separating colloidally dissed uranium oxides from the heavy water medium in upwhich they are contained. The method consists in treating such dispersions with hydrogen peroxide, thereby converting the uranium to non-colloidal UO/sub 4/, and separating the UO/sub 4/ sfter its rapid settling.

  7. SEPARATION OF THORIUM FROM URANIUM BY EXTRACTION

    DOEpatents

    Bohlmann, E.G.

    1959-07-28

    A method is presented for the recovery and separation of uranium and thorium values contained in an aqueous nitric acid solution which is more than 3 M in nitric acid. The uranium and thorium containing solution preferable about 7 M in nitric acid is contacted with tributyl phosphatekerosene mixture. Both U and Th are extracted by the immiscible organic. After phase separation the Th is selectively back extracted by contacting with an aqueous nitric acid solution preferably between 0.1 to 1.5 M in nitric acid. The uranium which is still in the organic extractant phase may be recovered by contacting with water.

  8. SEPARATION OF URANIUM FROM THORIUM

    DOEpatents

    Hellman, N.N.

    1959-07-01

    A process is presented for separating uranium from thorium wherein the ratio of thorium to uranium is between 100 to 10,000. According to the invention the thoriumuranium mixture is dissolved in nitric acid, and the solution is prepared so as to obtain the desired concentration within a critical range of from 4 to 8 N with regard to the total nitrate due to thorium nitrate, with or without nitric acid or any nitrate salting out agent. The solution is then contacted with an ether, such as diethyl ether, whereby uranium is extracted into ihe organic phase while thorium remains in the aqueous phase.

  9. SEPARATION OF PLUTONIUM FROM URANIUM

    DOEpatents

    Feder, H.M.; Nuttall, R.L.

    1959-12-15

    A process is described for extracting plutonium from powdered neutron- irradiated urarium metal by contacting the latter, while maintaining it in the solid form, with molten magnesium which takes up the plutonium and separating the molten magnesium from the solid uranium.

  10. SEPARATION OF URANIUM FROM THORIUM AND PROTACTINIUM

    DOEpatents

    Musgrave, W.K.R.

    1959-06-30

    This patent relates to the separation of uranium from thorium and protactinium; such mixtures of elements usually being obtained by neutron irradiation of thorium. The method of separating the constituents has been first to dissolve the mixture of elements in concertrated nitric acid and then to remove the protactinium by absorption on manganese dioxide and the uranium by solvent extraction with ether. Prior to now, comparatively large amounts of thorium were extracted with the uranium. According to the invention this is completely prevented by adding sodium diethyldithiocarbamate to the mixture of soluble nitrate salts. The organic salt has the effect of reacting only with the uranyl nitrate to form the corresponding uranyl salt which can then be selectively extracted from the mixture with amyl acetate.

  11. Study on selective separation of uranium(VI) by new N,N-dialkyl carboxy-amides

    SciTech Connect

    Suzuki, Shinichi; Sugo, Yumi; Kimura, Takaumi; Yaita, Tsuyoshi

    2007-07-01

    The Feasibility study (FS) on commercialized FR cycle systems has been carried out in Japan. In this Feasibility study, 'Advanced Aqueous' reprocessing was designed as a new reprocessing concept to enhance nuclear non-proliferation by recycling U, Pu and minor actinides (MA) with some fission products (FP). The crystallization and U(VI)/TRU(transuranics) co-extraction technique have been selected as candidate technique in the 'Advanced Aqueous' reprocessing. In JAEA, the result of Feasibility study was received and Fast Reactor Cycle Technology Development Project (FaCT) was started. In the nuclear spent fuel reprocessing, FBR spent fuels will coexist with LWR spent fuels for several decades until FBR cycle begins to operate. For the treatment of LWR spent fuels, high decontamination factor for FP was required for U(VI) storage, and solvent extraction technique was selected in the nuclear fuel treatment. In our laboratory, N,N-di-alkyl carboxy-amides have been developed as extractant based on solvent extraction technique for one of a back-up technology of 'Advanced Aqueous' reprocessing in FBR spent fuel treatments. N,N-di-alkyl carboxy-amides were noted as one of the alternative extractant of tri-butylphosphate (TBP) in the field of nuclear fuel reprocessing. Extraction behavior of U(VI) and Pu(IV) with N,N-di-alkyl carboxy-amides was almost similar to those with TBP. N,N-di-alkyl carboxy-amides have some advantages, namely, their complete incinerability (CHON principle) and high stability for hydrolysis and radiolysis. Their main degradation products are carboxylic acids and secondary amines which hardly affect the separation of U(VI) and Pu(IV) from fission products. Further, the synthesis of N,N-di-alkyl carboxy-amides was relatively easy with reaction of carboxylic chloride and secondary amine. The main purpose of this solvent extraction technique using N,N-di-alkyl carboxy-amides is selective separation of Uranium(VI) with branched N,N-di-alkyl carboxy

  12. SEPARATION OF URANIUM, PLUTONIUM, AND FISSION PRODUCTS

    DOEpatents

    Spence, R.; Lister, M.W.

    1958-12-16

    Uranium and plutonium can be separated from neutron-lrradiated uranium by a process consisting of dissolvlng the lrradiated material in nitric acid, saturating the solution with a nitrate salt such as ammonium nitrate, rendering the solution substantially neutral with a base such as ammonia, adding a reducing agent such as hydroxylamine to change plutonium to the trivalent state, treating the solution with a substantially water immiscible organic solvent such as dibutoxy diethylether to selectively extract the uranium, maklng the residual aqueous solutlon acid with nitric acid, adding an oxidizing agent such as ammonlum bromate to oxidize the plutonium to the hexavalent state, and selectlvely extracting the plutonium by means of an immlscible solvent, such as dibutoxy dlethyletber.

  13. PROCESS FOR SEPARATING URANIUM FISSION PRODUCTS

    DOEpatents

    Spedding, F.H.; Butler, T.A.; Johns, I.B.

    1959-03-10

    The removal of fission products such as strontium, barium, cesium, rubidium, or iodine from neutronirradiated uranium is described. Uranium halide or elemental halogen is added to melted irradiated uranium to convert the fission products to either more volatile compositions which vaporize from the melt or to higher melting point compositions which separate as solids.

  14. SEPARATION OF URANIUM, PLUTONIUM AND FISSION PRODUCTS

    DOEpatents

    Nicholls, C.M.; Wells, I.; Spence, R.

    1959-10-13

    The separation of uranium and plutonium from neutronirradiated uranium is described. The neutron-irradiated uranium is dissolved in nitric acid to provide an aqueous solution 3N in nitric acid. The fission products of the solution are extruded by treating the solution with dibutyl carbitol substantially 1.8N in nitric acid. The organic solvent phase is separated and neutralized with ammonium hydroxide and the plutonium reduced with hydroxylamine base to the trivalent state. Treatment of the mixture with saturated ammonium nitrate extracts the reduced plutonium and leaves the uranium in the organic solvent.

  15. METHOD OF SEPARATING URANIUM VALUES, PLUTONIUM VALUES AND FISSION PRODUCTS BY CHLORINATION

    DOEpatents

    Brown, H.S.; Seaborg, G.T.

    1959-02-24

    The separation of plutonium and uranium from each other and from other substances is described. In general, the method comprises the steps of contacting the uranium with chlorine in the presence of a holdback material selected from the group consisting of lanthanum oxide and thorium oxide to form a uranium chloride higher than uranium tetrachloride, and thereafter heating the uranium chloride thus formed to a temperature at which the uranium chloride is volatilized off but below the volatilizalion temperature of plutonium chloride.

  16. SEPARATION OF URANIUM FROM OTHER METALS

    DOEpatents

    Hyman, H.H.

    1959-07-01

    The separation of uranium from other elements, such as ruthenium, zirconium, niobium, cerium, and other rare earth metals is described. According to the invention, this is accomplished by adding hydrazine to an acid aqueous solution containing salts of uranium, preferably hexavalent uranium, and then treating the mixture with a substantially water immiscible ketone, such as hexone. A reaction takes place between the ketone and the hydrazine whereby a complex, a ketazine, is formed; this complex has a greater power of extraction for uranium than the ketone by itself. When contaminating elements are present, they substantially remain in ihe aqueous solution.

  17. METHOD OF SEPARATING URANIUM FROM ALLOYS

    DOEpatents

    Chiotti, P.; Shoemaker, H.E.

    1960-06-28

    Uranium can be recovered from metallic uraniumthorium mixtures containing uranium in comparatively small amounts. The method of recovery comprises adding a quantity of magnesium to a mass to obtain a content of from 48 to 85% by weight; melting and forming a magnesium-thorium alloy at a temperature of between 585 and 800 deg C; agitating the mixture, allowing the mixture to settle whereby two phases, a thorium-containing magnesium-rich liquid phase and a solid uranium-rich phase, are formed; and separating the two phases.

  18. SEPARATION OF PLUTONIUM FROM URANIUM AND FISSION PRODUCTS

    DOEpatents

    Boyd, G.E.; Adamson, A.W.; Schubert, J.; Russell, E.R.

    1958-10-01

    A chromatographic adsorption process is presented for the separation of plutonium from other fission products formed by the irradiation of uranium. The plutonium and the lighter element fission products are adsorbed on a sulfonated phenol-formaldehyde resin bed from a nitric acid solution containing the dissolved uranium. Successive washes of sulfuric, phosphoric, and nitric acids remove the bulk of the fission products, then an eluate of dilute phosphoric and nitric acids removes the remaining plutonium and fission products. The plutonium is selectively removed by passing this solution through zirconium phosphate, from which the plutonium is dissolved with nitric acid. This process provides a convenient and efficient means for isolating plutonium.

  19. COLUMBIC OXIDE ADSORPTION PROCESS FOR SEPARATING URANIUM AND PLUTONIUM IONS

    DOEpatents

    Beaton, R.H.

    1959-07-14

    A process is described for separating plutonium ions from a solution of neutron irradiated uranium in which columbic oxide is used as an adsorbert. According to the invention the plutonium ion is selectively adsorbed by Passing a solution containing the plutonium in a valence state not higher than 4 through a porous bed or column of granules of hydrated columbic oxide. The adsorbed plutonium is then desorbed by elution with 3 N nitric acid.

  20. SEPARATION OF PLUTONIUM VALUES FROM URANIUM AND FISSION PRODUCT VALUES

    DOEpatents

    Maddock, A.G.; Booth, A.H.

    1960-09-13

    Separation of plutonium present in small amounts from neutron irradiated uranium by making use of the phenomenon of chemisorption is described. Plutonium in the tetravalent state is chemically absorbed on a fluoride in solid form. The steps for the separation comprise dissolving the irradiated uranium in nitric acid, oxidizing the plutonium in the resulting solution to the hexavalent state, adding to the solution a soluble calcium salt which by the common ion effect inhibits dissolution of the fluoride by the solution, passing the solution through a bed or column of subdivided calcium fluoride which has been sintered to about 8OO deg C to remove the chemisorbable fission products, reducing the plutonium in the solution thus obtained to the tetravalent state, and again passing the solution through a similar bed or column of calcium fluoride to selectively absorb the plutonium, which may then be recovered by treating the calcium fluoride with a solution of ammonium oxalate.

  1. METHOD OF SEPARATING ISOTOPES OF URANIUM IN A CALUTRON

    DOEpatents

    Jenkins, F.A.

    1958-05-01

    Mass separation devices of the calutron type and the use of uranium hexachloride as a charge material in the calutron ion source are described. The method for using this material in a mass separator includes heating the uranium hexachloride to a temperature in the range of 60 to 100 d C in a vacuum and thereby forming a vapor of the material. The vaporized uranium hexachloride is then ionized in a vapor ionizing device for subsequent mass separation processing.

  2. SEPARATION OF URANIUM, PLUTONIUM AND FISSION PRODUCTS FROM NEUTRON- BOMBARDED URANIUM

    DOEpatents

    Martin, A.E.; Johnson, I.; Burris, L. Jr.; Winsch, I.O.; Feder, H.M.

    1962-11-13

    A process is given for removing plutonium and/or fission products from uranium fuel. The fuel is dissolved in molten zinc--magnesium (10 to 18% Mg) alloy, more magnesium is added to obtain eutectic composition whereby uranium precipitates, and the uranium are separated from the Plutoniumand fission-product- containing eutectic. (AEC)

  3. Uranium Metal Analysis via Selective Dissolution

    SciTech Connect

    Delegard, Calvin H.; Sinkov, Sergey I.; Schmidt, Andrew J.; Chenault, Jeffrey W.

    2008-09-10

    Uranium metal, which is present in sludge held in the Hanford Site K West Basin, can create hazardous hydrogen atmospheres during sludge handling, immobilization, or subsequent transport and storage operations by its oxidation/corrosion in water. A thorough knowledge of the uranium metal concentration in sludge therefore is essential to successful sludge management and waste process design. The goal of this work was to establish a rapid routine analytical method to determine uranium metal concentrations as low as 0.03 wt% in sludge even in the presence of up to 1000-fold higher total uranium concentrations (i.e., up to 30 wt% and more uranium) for samples to be taken during the upcoming sludge characterization campaign and in future analyses for sludge handling and processing. This report describes the experiments and results obtained in developing the selective dissolution technique to determine uranium metal concentration in K Basin sludge.

  4. Selective Extraction of Uranium from Liquid or Supercritical Carbon Dioxide

    SciTech Connect

    Farawila, Anne F.; O'Hara, Matthew J.; Wai, Chien M.; Taylor, Harry Z.; Liao, Yu-Jung

    2012-07-31

    , reductant or complexant used for selectivity, and ionic liquids used as supportive media. To complete the extraction and recovery cycle, we then demonstrate uranium back extraction from the TBP loaded sc-CO2 phase into an aqueous phase and the characterization of the uranium complex formed at the end of this process. Another aspect of this project was to limit proliferation risks by either co-extracting uranium and plutonium, or by leaving plutonium behind by selectively extracting uranium. We report that the former is easily achieved, since plutonium is in the tetravalent or hexavalent oxidation state in the oxidizing environment created by the TBP-nitric acid complex, and is therefore co-extracted. The latter is more challenging, as a reductant or complexant to plutonium has to be used to selectively extract uranium. After undertaking experiments on different reducing or complexing systems (e.g., AcetoHydroxamic Acid (AHA), Fe(II), ascorbic acid), oxalic acid was chosen as it can complex tetravalent actinides (Pu, Np, Th) in the aqueous phase while allowing the extraction of hexavalent uranium in the sc-CO2 phase. Finally, we show results using an alternative media to commonly used aqueous phases: ionic liquids. We show the dissolution of uranium in ionic liquids and its extraction using sc-CO2 with and without the presence of AHA. The possible separation of trivalent actinides from uranium is also demonstrated in ionic liquids using neodymium as a surrogate and diglycolamides as the extractant.

  5. Separation of uranium isotopes by chemical exchange

    DOEpatents

    Ogle, P.R. Jr.

    1974-02-26

    A chemical exchange method is provided for separating /sup 235/U from / sup 238/U comprising contacting a first phase containing UF/sub 6/ with a second phase containing a compound selected from the group consisting of NOUF/sub 6/, NOUF/sub 7/, and NO/sub 2/UF/sub 7/ until the U Fsub 6/ in the first phase becomes enriched in the /sup 235/U isotope. (Official Gazette)

  6. SEPARATION OF PLUTONIUM FROM URANIUM AND FISSION PRODUCTS BY ADSORPTION

    DOEpatents

    Seaborg, G.T.; Willard, J.E.

    1958-01-01

    A method is presented for the separation of plutonium from solutions containing that element in a valence state not higher than 41 together with uranium ions and fission products. This separation is accomplished by contacting the solutions with diatomaceous earth which preferentially adsorbs the plutonium present. Also mentioned as effective for this adsorbtive separation are silica gel, filler's earth and alumina.

  7. Selective leaching of uranium from uranium-contaminated soils

    SciTech Connect

    Francis, C.W.; Mattus, A.J.; Farr, L.L.; Lee, S.Y.; Elless, M.P. |

    1993-06-01

    Three soils and a sediment contaminated with uranium were used to determine the effectiveness of sodium carbonate and citric acid leaching to decontaminate or remove uranium to acceptable regulatory levels. The objective was to selectively extract uranium using a soil washing/extraction process without seriously degrading the soil`s physicochemical characteristics or generating a secondary waste form that would be difficult to manage and/or dispose of. Two of the soils were surface soils from the DOE facility formerly called the Feed Materials Production Center (FMPC) at Fernald, Ohio. One of the soils is from near the Plant 1 storage pad and the other soil was taken from near a waste incinerator used to burn low-level contaminated trash. The third soil was a surface soil from an area formally used as a landfarm for the treatment of spent oils at the Oak Ridge Y-12 Plant. The sediment sample was material sampled from a storm sewer sediment trap at the Oak Ridge Y-12 Plant. Uranium concentrations in the Fernald soils ranged from 450 to 550 {mu}g U/g of soil while the samples from the Y-12 Plant ranged from 150 to 200 {mu}g U/g of soil.

  8. PROCESS OF TREATING URANIUM HEXAFLUORIDE AND PLUTONIUM HEXAFLUORIDE MIXTURES WITH SULFUR TETRAFLUORIDE TO SEPARATE SAME

    DOEpatents

    Steindler, M.J.

    1962-07-24

    A process was developed for separating uranium hexafluoride from plutonium hexafluoride by the selective reduction of the plutonium hexafluoride to the tetrafluoride with sulfur tetrafluoride at 50 to 120 deg C, cooling the mixture to --60 to -100 deg C, and volatilizing nonreacted sulfur tetrafluoride and sulfur hexafluoride formed at that temperature. The uranium hexafluoride is volatilized at room temperature away from the solid plutonium tetrafluoride. (AEC)

  9. Pulsed CO laser for isotope separation of uranium

    SciTech Connect

    Baranov, Igor Y.; Koptev, Andrey V.

    2012-07-30

    This article proposes a technical solution for using a CO laser facility for the industrial separation of uranium used in the production of fuel for nuclear power plants, employing a method of laser isotope separation of uranium with condensation repression in a free jet. The laser operation with nanosecond pulse irradiation can provide an acceptable efficiency in the separating unit and a high efficiency of the laser with the wavelength of 5.3 {mu}m. In the present work we also introduce a calculation model and define the parameters of a mode-locked CO laser with a RF discharge in the supersonic stream. The average pulsed CO laser power of 3 kW is sufficient for efficient industrial isotope separation of uranium in one stage.

  10. Pulsed CO laser for isotope separation of uranium

    NASA Astrophysics Data System (ADS)

    Baranov, Igor Y.; Koptev, Andrey V.

    2012-07-01

    This article proposes a technical solution for using a CO laser facility for the industrial separation of uranium used in the production of fuel for nuclear power plants, employing a method of laser isotope separation of uranium with condensation repression in a free jet. The laser operation with nanosecond pulse irradiation can provide an acceptable efficiency in the separating unit and a high efficiency of the laser with the wavelength of 5.3 μm. In the present work we also introduce a calculation model and define the parameters of a mode-locked CO laser with a RF discharge in the supersonic stream. The average pulsed CO laser power of 3 kW is sufficient for efficient industrial isotope separation of uranium in one stage.

  11. Uranium isotope separation from 1941 to the present

    NASA Astrophysics Data System (ADS)

    Maier-Komor, Peter

    2010-02-01

    Uranium isotope separation was the key development for the preparation of highly enriched isotopes in general and thus became the seed for target development and preparation for nuclear and applied physics. In 1941 (year of birth of the author) large-scale development for uranium isotope separation was started after the US authorities were warned that NAZI Germany had started its program for enrichment of uranium and might have confiscated all uranium and uranium mines in their sphere of influence. Within the framework of the Manhattan Projects the first electromagnetic mass separators (Calutrons) were installed and further developed for high throughput. The military aim of the Navy Department was to develop nuclear propulsion for submarines with practically unlimited range. Parallel to this the army worked on the development of the atomic bomb. Also in 1941 plutonium was discovered and the production of 239Pu was included into the atomic bomb program. 235U enrichment starting with natural uranium was performed in two steps with different techniques of mass separation in Oak Ridge. The first step was gas diffusion which was limited to low enrichment. The second step for high enrichment was performed with electromagnetic mass spectrometers (Calutrons). The theory for the much more effective enrichment with centrifugal separation was developed also during the Second World War, but technical problems e.g. development of high speed ball and needle bearings could not be solved before the end of the war. Spying accelerated the development of uranium separation in the Soviet Union, but also later in China, India, Pakistan, Iran and Iraq. In this paper, the physical and chemical procedures are outlined which lead to the success of the project. Some security aspects and Non-Proliferation measures are discussed.

  12. SOLVENT EXTRACTION PROCESS FOR THE SEPARATION OF URANIUM AND THORIUM FROM PROTACTINIUM AND FISSION PRODUCTS

    DOEpatents

    Rainey, R.H.; Moore, J.G.

    1962-08-14

    A liquid-liquid extraction process was developed for recovering thorium and uranium values from a neutron irradiated thorium composition. They are separated from a solvent extraction system comprising a first end extraction stage for introducing an aqueous feed containing thorium and uranium into the system consisting of a plurality of intermediate extractiorr stages and a second end extractron stage for introducing an aqueous immiscible selective organic solvent for thorium and uranium in countercurrent contact therein with the aqueous feed. A nitrate iondeficient aqueous feed solution containing thorium and uranium was introduced into the first end extraction stage in countercurrent contact with the organic solvent entering the system from the second end extraction stage while intro ducing an aqueous solution of salting nitric acid into any one of the intermediate extraction stages of the system. The resultant thorium and uranium-laden organic solvent was removed at a point preceding the first end extraction stage of the system. (AEC)

  13. Age determination of highly enriched uranium: separation and analysis of 231Pa.

    PubMed

    Morgenstern, A; Apostolidis, C; Mayer, K

    2002-11-01

    An analytical procedure has been developed for the age determination of highly enriched uranium samples exploiting the mother/daughter pair 235U/231Pa. Protactinium is separated from bulk uranium through highly selective sorption to silica gel and is subsequently quantified using alpha-spectrometry. The method has been validated using uranium standard reference materials of known ages. It affords decontamination factors exceeding 2.5 x 10(7), overall recoveries in the range of 80-85%, and a combined uncertainty below 5%.

  14. Age determination of highly enriched uranium: separation and analysis of 231Pa.

    PubMed

    Morgenstern, A; Apostolidis, C; Mayer, K

    2002-11-01

    An analytical procedure has been developed for the age determination of highly enriched uranium samples exploiting the mother/daughter pair 235U/231Pa. Protactinium is separated from bulk uranium through highly selective sorption to silica gel and is subsequently quantified using alpha-spectrometry. The method has been validated using uranium standard reference materials of known ages. It affords decontamination factors exceeding 2.5 x 10(7), overall recoveries in the range of 80-85%, and a combined uncertainty below 5%. PMID:12433081

  15. PROCESS OF SEPARATING PLUTONIUM FROM URANIUM

    DOEpatents

    Brown, H.S.; Hill, O.F.

    1958-09-01

    A process is presented for recovering plutonium values from aqueous solutions. It comprises forming a uranous hydroxide precipitate in such a plutonium bearing solution, at a pH of at least 5. The plutonium values are precipitated with and carried by the uranium hydroxide. The carrier precipitate is then redissolved in acid solution and the pH is adjusted to about 2.5, causing precipitation of the uranous hydroxide but leaving the still soluble plutonium values in solution.

  16. SEPARATION OF URANIUM FROM ZIRCONIUM AND NIOBIUM BY SOLVENT EXTRACTION

    DOEpatents

    Voiland, E.E.

    1958-05-01

    A process for separation of the uranium from zirconium and/or niobium values contained in 3 to 7M aqueous nitric acid solutions is described. This is accomplished by adding phosphoric acid anions to the nitric acid solution containing the uranium, zirconium, and/or niobium in an amount sufficient to make the solution 0.05 to 0.2M in phosphate ion and contacting the solution with an organic water-immiscible solvent such as MEK, whereby the uranyl values are taken up by the extract phase while the zirconium and niobium preferentially remain in the aqueous raffinate.

  17. ADSORPTION METHOD FOR SEPARATING THORIUM VALUES FROM URANIUM VALUES

    DOEpatents

    Boyd, G.E.; Russell, E.R.; Schubert, J.

    1959-08-01

    An improved ion exchange method is described for recovery of uranium and thorium values as separate functions from an aqueous acidic solution containing less than 10/sup -3/ M thorium ions and between 0.1 and 1 M uranyl ions. The solution is passed through a bed of cation exchange resin in the acid form to adsorb all the thorium ions and a portion of the uranyl ions. The uranium is eluted by means of aqueous 0.1 to 0.4 M sulfuric acid. The thorium may then be stripped from the resin by elution with aqueous 0.5 M oxalic acid.

  18. SEPARATION OF URANIUM AND PLUTONIUM OXIDES

    DOEpatents

    Benedict, G.E.; Lyon, W.L.

    1961-12-01

    ABS>A method of separating a mixture of UO/sub 2/ and PuO/sub 2/ is given which comprises immersing the mixture in a fused NaCl-KCl bath, chlorinating with chlorine or phosgene, and preferentially electrolytically or chemically reducing the UO/sub 2/Cl/sub 2/ so produced to UO/sub 2/ and filtering it out. (AEC)

  19. Bio-/Photo-Chemical Separation and Recovery of Uranium

    SciTech Connect

    Francis,A.J.; Dodge, C.J.

    2008-03-12

    Citric acid forms bidentate, tridentate, binuclear or polynuclear species with transition metals and actinides. Biodegradation of metal citrate complexes is influenced by the type of complex formed with metal ions. While bidentate complexes are readily biodegraded, tridentate, binuclear and polynuclear species are recalcitrant. Likewise certain transition metals and actinides are photochemically active in the presence of organic acids. Although the uranyl citrate complex is not biodegraded, in the presence of visible light it undergoes photochemical oxidation/reduction reactions which result in the precipitation of uranium as UO{sub 3} {center_dot} H{sub 2}O. Consequently, we developed a process where uranium is extracted from contaminated soils and wastes by citric acid. The citric-acid extract is subjected to biodegradation to recover the toxic metals, whereas uranyl citrate which is recalcitrant remains in solution. Photochemical degradation of the uranium citrate complex resulted in the precipitation of uranium. Thus the toxic metals and uranium in mixed waste are recovered in separate fractions for recycling or for disposal. The use of naturally-occurring compounds and the combined chemical and microbiological treatment process is more efficient than present methods and should result in considerable savings in cost.

  20. Supercritical Fluid Extraction and Separation of Uranium from Other Actinides

    SciTech Connect

    Donna L. Quach; Bruce J. Mincher; Chien M. Wai

    2014-06-01

    This paper investigates the feasibility of separating uranium from other actinides by using supercritical fluid carbon dioxide (sc-CO2) as a solvent modified with tri-n-butylphosphate (TBP) for the development of an extraction and counter current stripping technique, which would be a more efficient and environmentally benign technology for used nuclear fuel reprocessing compared to traditional solvent extraction. Several actinides (U(VI), Np(VI), Pu(IV), and Am(III)) were extracted in sc-CO2 modified with TBP over a range of nitric acid concentrations and then the actinides were exposed to reducing and complexing agents to suppress their extractability. According to this study, the separation of uranium from plutonium in sc-CO2 modified with TBP was successful at nitric acid concentrations of less than 3 M in the presence of acetohydroxamic acid or oxalic acid, and the separation of uranium from neptunium was successful at nitric acid concentrations of less than 1 M in the presence of acetohydroxamic acid, oxalic acid, or sodium nitrite.

  1. Uranium dioxide in Fe(III)-containing ionic liquids with DMSO: Dissolution, separation, and structural characterization

    NASA Astrophysics Data System (ADS)

    Yao, Aining; Chu, Taiwei

    2016-11-01

    UO2 can be successfully dissolved in imidazolium-based Fe(III)-containing ionic liquids (ILs) with the help of DMSO. Spectroscopic studies and X-ray diffraction show that UO2Cl42- is the principal product. The dissolved uranyl species can be easily separated from the ILs via a combination of crystallization and solvent extraction. Moreover, even if 15.2 wt% of the rare-earth elements of Sm, Eu, and Gd, compared with the total amount of uranium and the rare-earth elements, exist in the IL, only uranium-containing crystals would be selectively formed and separated from the system. The solvents of acetone and acetonitrile could be used to separate the rare-earth elements from uranium in the IL with the help of imidazolium chloride. Considering the complete process from the dissolution of UO2 and some rare-earth oxides to the separation of uranium and rare-earth elements in the IL, the facile approach is promising for the spent nuclear fuel reprocessing.

  2. Separation of thorium and uranium in nitric acid solution using silica based anion exchange resin.

    PubMed

    Chen, Yanliang; Wei, Yuezhou; He, Linfeng; Tang, Fangdong

    2016-09-30

    To separate thorium and uranium in nitric acid solution using anion exchange process, a strong base silica-based anion exchange resin (SiPyR-N4) was synthesized. Batch experiments were conducted and the separation factor of thorium and uranium in 9M nitric acid was about 10. Ion exchange chromatography was applied to separate thorium and uranium in different ratios. Uranium could be eluted by 9M nitric acid and thorium was eluted by 0.1M nitric acid. It was proved that thorium and uranium can be separated and recovered successfully by this method.

  3. Separation of thorium and uranium in nitric acid solution using silica based anion exchange resin.

    PubMed

    Chen, Yanliang; Wei, Yuezhou; He, Linfeng; Tang, Fangdong

    2016-09-30

    To separate thorium and uranium in nitric acid solution using anion exchange process, a strong base silica-based anion exchange resin (SiPyR-N4) was synthesized. Batch experiments were conducted and the separation factor of thorium and uranium in 9M nitric acid was about 10. Ion exchange chromatography was applied to separate thorium and uranium in different ratios. Uranium could be eluted by 9M nitric acid and thorium was eluted by 0.1M nitric acid. It was proved that thorium and uranium can be separated and recovered successfully by this method. PMID:27614730

  4. Separation of uranium from (Th,U)O.sub.2 solid solutions

    DOEpatents

    Chiotti, Premo; Jha, Mahesh Chandra

    1976-09-28

    Uranium is separated from mixed oxides of thorium and uranium by a pyrometallurgical process in which the oxides are mixed with a molten chloride salt containing thorium tetrachloride and thorium metal which reduces the uranium oxide to uranium metal which can then be recovered from the molten salt. The process is particularly useful for the recovery of uranium from generally insoluble high-density sol-gel thoria-urania nuclear reactor fuel pellets.

  5. METHOD OF SEPARATING URANIUM, PLUTONIUM AND FISSION PRODUCTS BY BROMINATION AND DISTILLATION

    DOEpatents

    Jaffey, A.H.; Seaborg, G.T.

    1958-12-23

    The method for separation of plutonium from uranium and radioactive fission products obtained by neutron irradiation of uranlum consists of reacting the lrradiated material with either bromine, hydrogen bromide, alumlnum bromide, or sulfur and bromine at an elevated temperature to form the bromides of all the elements, then recovering substantlally pure plutonium bromide by dlstillatlon in combinatlon with selective condensatlon at prescribed temperature and pressure.

  6. PROCESSES FOR SEPARATING AND RECOVERING CONSTITUENTS OF NEUTRON IRRADIATED URANIUM

    DOEpatents

    Connick, R.E.; Gofman, J.W.; Pimentel, G.C.

    1959-11-10

    Processes are described for preparing plutonium, particularly processes of separating plutonium from uranium and fission products in neutron-irradiated uraniumcontaining matter. Specifically, plutonium solutions containing uranium, fission products and other impurities are contacted with reducing agents such as sulfur dioxide, uranous ion, hydroxyl ammonium chloride, hydrogen peroxide, and ferrous ion whereby the plutoninm is reduced to its fluoride-insoluble state. The reduced plutonium is then carried out of solution by precipitating niobic oxide therein. Uranium and certain fission products remain behind in the solution. Certain other fission products precipitate along with the plutonium. Subsequently, the plutonium and fission product precipitates are redissolved, and the solution is oxidized with oxidizing agents such as chlorine, peroxydisulfate ion in the presence of silver ion, permanganate ion, dichromate ion, ceric ion, and a bromate ion, whereby plutonium is oxidized to the fluoride-soluble state. The oxidized solution is once again treated with niobic oxide, thus precipitating the contamirant fission products along with the niobic oxide while the oxidized plutonium remains in solution. Plutonium is then recovered from the decontaminated solution.

  7. METHOD OF SEPARATING FISSION PRODUCTS FROM FUSED BISMUTH-CONTAINING URANIUM

    DOEpatents

    Wiswall, R.H.

    1958-06-24

    A process is described for removing metal selectively from liquid metal compositions. The method effects separation of flssion product metals selectively from dilute solution in fused bismuth, which contains uraniunn in solution without removal of more than 1% of the uranium. The process comprises contacting the fused bismuth with a fused salt composition consisting of sodium, potassium and lithium chlorides, adding to fused bismuth and molten salt a quantity of bismuth chloride which is stoichiometrically required to convert the flssion product metals to be removed to their chlorides which are more stable in the fused salt than in the molten metal and are, therefore, preferentially taken up in the fused salt phase.

  8. Selective removal of dissolved uranium in drinking water by nanofiltration.

    PubMed

    Favre-Réguillon, A; Lebuzit, G; Murat, D; Foos, J; Mansour, C; Draye, M

    2008-02-01

    A procedure for the selective removal of uranium traces dissolved in drinking water has been studied. Plate module membrane filtration equipment was operated to evaluate the performance and selectivity of three different nanofiltration flat-sheet membranes. Experiments were carried out using various commercial mineral waters with distinct physicochemical compositions. The membranes were first discriminating by their ability to reject uranium in the presence of the main cations found in mineral waters, using a 2 mg L(-1) (2000 ppb) concentration of uranium. The rejection of U(VI) was dependent on the uranyl speciation and the ionic strength. Second, removal of uranium traces (0.02 mg L(-1), 20 ppb) was performed using the nanofiltration membrane showing the highest selectivity for uranium toward alkaline and alkaline-earth ions. The results showed a high performance of the nanofiltration membrane, Osmonics DL, for selective uranium rejection at low pressure (1 bar), illustrating the advantage of nanofiltration for the selective removal of uranium from drinking water.

  9. Innovative lasers for uranium isotope separation. [Progress report

    SciTech Connect

    Brake, M.L.; Gilgenbach, R.M.

    1991-06-01

    Copper vapor lasers have important applications to uranium atomic vapor laser isotope separation (AVLIS). The authors have spent the first two years of their project investigating two innovative methods of exciting/pumping copper vapor lasers which have the potential to improve the efficiency and scaling of large laser systems used in uranium isotope separation. Experimental research has focused on the laser discharge kinetics of (1) microwave, and (2) electron beam excitation/pumping of large-volume copper vapor lasers. During the first year, the experiments have been designed and constructed and initial data has been taken. During the second year these experiments have been diagnosed. Highlights of some of the second year results as well as plans for the future include the following: Microwave resonant cavity produced copper vapor plasmas at 2.45 GHz, have been investigated. A CW (0--500 W) signal heats and vaporizes the copper chloride to provide the atomic copper vapor. A pulsed (5 kW, 0.5--5kHz) signal is added to the incoming CW signal via a hybrid mixer to excite the copper states to the laser levels. An enhancement of the visible radiation has been observed during the pulsed pardon of the signal. Electrical probe measurements have been implemented on the system to verify the results of the electromagnetic model formulated last year. Laser gain measurements have been initiated with the use of a commercial copper vapor laser. Measurements of the spatial profile of the emission are also currently being made. The authors plan to increase the amount of pulsed microwave power to the system by implementing a high power magnetron. A laser cavity will be designed and added to this system.

  10. Method of separating and recovering uranium and related cations from spent Purex-type systems

    DOEpatents

    Mailen, J.C.; Tallent, O.K.

    1987-02-25

    A process for separating uranium and related cations from a spent Purex-type solvent extraction system which contains degradation complexes of tributylphosphate wherein the system is subjected to an ion-exchange process prior to a sodium carbonate scrubbing step. A further embodiment comprises recovery of the separated uranium and related cations. 5 figs.

  11. Separation of uranium from technetium in recovery of spent nuclear fuel

    DOEpatents

    Pruett, D.J.; McTaggart, D.R.

    1983-08-31

    Uranium and technetium in the product stream of the Purex process for recovery of uranium in spent nuclear fuel are separated by (1) contacting the aqueous Purex product stream with hydrazine to reduce Tc/sup +7/ therein to a reduced species, and (2) contacting said aqueous stream with an organic phase containing tributyl phosphate and an organic diluent to extract uranium from said aqueous stream into said organic phase.

  12. Separation of uranium from technetium in recovery of spent nuclear fuel

    DOEpatents

    Pruett, David J.; McTaggart, Donald R.

    1984-01-01

    Uranium and technetium in the product stream of the Purex process for recovery of uranium in spent nuclear fuel are separated by (1) contacting the aqueous Purex product stream with hydrazine to reduce Tc.sup.+7 therein to a reduced species, and (2) contacting said aqueous stream with an organic phase containing tributyl phosphate and an organic diluent to extract uranium from said aqueous stream into said organic phase.

  13. Selective solid-phase extraction of uranium by salicylideneimine-functionalized hydrothermal carbon.

    PubMed

    Wang, Hang; Ma, Lijian; Cao, Kecheng; Geng, Junxia; Liu, Jun; Song, Qiang; Yang, Xiaodan; Li, Shoujian

    2012-08-30

    A new salicylideneimine-functionalized hydrothermal-carbon-based solid-phase extractant was developed for the purpose of separating uranium selectively for sustainability of uranium resources. The resulting adsorption material was obtained via hydrothermal carbonization, calcination at mild temperature (573.15K), amination, and grafting with salicylaldehyde in sequence. Both Fourier transform infrared spectra and elemental analysis proved the successful grafting of salicylideneimine onto hydrothermal carbon matrix. Adsorption behaviors of the extractant on uranium(VI) were investigated by varying pH values of solution, adsorbent amounts, contact times, initial metal concentrations, temperatures, and ionic strengths. An optimum adsorption capacity of 1.10 mmol g(-1) (261 mg g(-1)) for uranium(VI) was obtained at pH 4.3. The present adsorption process obeyed pseudo-second-order model and Langmuir isotherm. Thermodynamic parameters (ΔH=+8.81 kJ mol(-1), ΔS=+110 J K(-1)mol(-1), ΔG=-23.0 kJ mol(-1)) indicated the adsorption process was endothermic and spontaneous. Results from batch adsorption test in simulated nuclear industrial effluent, containing Cs(+), Sr(2+), Ba(2+), Mn(2+), Co(2+), Ni(2+), Zn(2+), La(3+), Ce(3+), Nd(3+), Sm(3+), and Gd(3+), showed the adsorbent could separate uranium(VI) from those competitive ions with high selectivity. The adsorbent might be promising for use in certain key steps in any future sustainable nuclear fuel cycle.

  14. Separation and Recovery of Uranium Metal from Spent Light Water Reactor Fuel via Electrolytic Reduction and Electrorefining

    SciTech Connect

    S. D. Herrmann; S. X. Li

    2010-09-01

    A series of bench-scale experiments was performed in a hot cell at Idaho National Laboratory to demonstrate the separation and recovery of uranium metal from spent light water reactor (LWR) oxide fuel. The experiments involved crushing spent LWR fuel to particulate and separating it from its cladding. Oxide fuel particulate was then converted to metal in a series of six electrolytic reduction runs that were performed in succession with a single salt loading of molten LiCl – 1 wt% Li2O at 650 °C. Analysis of salt samples following the series of electrolytic reduction runs identified the diffusion of select fission products from the spent fuel to the molten salt electrolyte. The extents of metal oxide conversion in the post-test fuel were also quantified, including a nominal 99.7% conversion of uranium oxide to metal. Uranium metal was then separated from the reduced LWR fuel in a series of six electrorefining runs that were performed in succession with a single salt loading of molten LiCl-KCl-UCl3 at 500 °C. Analysis of salt samples following the series of electrorefining runs identified additional partitioning of fission products into the molten salt electrolyte. Analyses of the separated uranium metal were performed, and its decontamination factors were determined.

  15. ARSENATE CARRIER PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM NEUTRON IRRADIATED URANIUM AND RADIOACTIVE FISSION PRODUCTS

    DOEpatents

    Thompson, S.G.; Miller, D.R.; James, R.A.

    1961-06-20

    A process is described for precipitating Pu from an aqueous solution as the arsenate, either per se or on a bismuth arsenate carrier, whereby a separation from uranium and fission products, if present in solution, is accomplished.

  16. Mesoporous Carbon Membranes for Selective Gas Separations

    SciTech Connect

    2009-04-01

    This factsheet describes a study whose focus is on translating a novel class of material developed at Oak Ridge National Laboratory—selfassembled mesoporous carbon—into robust, efficient membrane systems for selective industrial gas separations.

  17. Ligand-grafted biomaterials for adsorptive separations of uranium in solution

    SciTech Connect

    Hu, M.Z.C.; Reeves, M.

    1999-11-01

    Many organic molecules, particularly biologicals, contain functional groups (ligands) that actively interact with metal ions in solution by adsorption, ion exchange, or chelation/coordination/complexation. Water-soluble organics have limitations as reagents for metal-ion separations from aqueous solutions. However, if the ligand molecule(s) are grafted on to an insoluble matrix, the resulting ligand(s)-containing product becomes useful for separations applications related to metal recovery or remediation. It was discovered that biomolecules containing a primary amino group, secondary amino group, or hydroxyl group could be grafted into a polyurethane polymeric network via in situ polymerization reactions. With carboxyl groups, grafted material showed good selectivity among a group of divalent metal cations, and a uranium-binding capacity of more than 10 mg/g of polymer. The material can be regenerated by sodium bicarbonate or sodium carbonate solution and reused. Data from a stirred-tank reactor showed fast uranium-binding kinetics, and breakthrough-elution studies with a packed-column reactor indicated promising process behavior.

  18. Selective oxoanion separation using a tripodal ligand

    DOEpatents

    Custelcean, Radu; Moyer, Bruce A.; Rajbanshi, Arbin

    2016-02-16

    The present invention relates to urea-functionalized crystalline capsules self-assembled by sodium or potassium cation coordination and by hydrogen-bonding water bridges to selectively encapsulate tetrahedral divalent oxoanions from highly competitive aqueous alkaline solutions and methods using this system for selective anion separations from industrial solutions. The method involves competitive crystallizations using a tripodal tris(urea) functionalized ligand and, in particular, provides a viable approach to sulfate separation from nuclear wastes.

  19. Evaluating ion exchange resin efficiency and oxidative capacity for the separation of uranium(IV) and uranium(VI)

    PubMed Central

    2013-01-01

    Background Previously described methods to separate dissolved U(IV) from dissolved U(VI) under acidic anoxic conditions prior to laboratory analysis were ineffective with materials currently available commercially. Three strong anion exchange resins were examined for their efficiency in separating, recovering, and preserving both redox states during separation. Results Under oxic conditions, recovery of U(VI) from three exchange resins (Bio-Rad AG® 1x8 Poly-Prep® prefilled columns, Bio-Rad AG® 1x8 powder, and Dowex® 1x8 powder) ranged from 72% to 100% depending on the dosed mass, eluent volume, and resin selected. Dowex® 1x8 resin was the only resin found to provide 100% recovery of U(VI) with fewer than 5 bed volumes of eluent. Under anoxic conditions, all three resins oxidized U(IV) in aqueous solutions with relatively low U(IV) concentrations (<3x10-6 M). Resin-induced oxidation was observed visually using a leuco dye, safranin-o. Oxidants associated with the resin were irreversibly reduced by the addition of Ti(III). After anoxic resin pre-treatment, a series of U(IV)/U(VI) mixtures at micro-molar levels were prepared and separated using the Dowex® 1x8 resin with 100% recovery of both U(IV) and U(VI) with no resin-induced changes in oxidation state. Conclusions Currently available anion exchange resins with apparently identical physical properties were found to have significantly different recoveries for hexavalent uranium at micro-molar concentrations. A novel qualitative technique was developed to visually assess oxidative capacities of anion exchange resins under acidic anoxic conditions. A protocol was developed for pre-treatment and use of currently available anion exchange resins to achieve quantitative separation of U(IV) and U(VI) in aqueous solutions with low U(IV) concentrations. This method can be applied to future work to quantitatively assess dissolved U(IV) and U(VI) concentrations in both laboratory and field samples. PMID:23363052

  20. Separation of uranium from technetium in recovery of spent nuclear fuel

    DOEpatents

    Friedman, H.A.

    1984-06-13

    A method for decontaminating uranium product from the Purex 5 process comprises addition of hydrazine to the product uranyl nitrate stream from the Purex process, which contains hexavalent (UO/sub 2//sup 2 +/) uranium and heptavalent technetium (TcO/sub 4/-). Technetium in the product stream is reduced and then complexed by the addition of oxalic acid (H/sub 2/C/sub 2/O/sub 4/), and the Tc-oxalate complex is readily separated from the 10 uranium by solvent extraction with 30 vol % tributyl phosphate in n-dodecane.

  1. Separation of uranium from technetium in recovery of spent nuclear fuel

    DOEpatents

    Friedman, Horace A.

    1985-01-01

    A method for decontaminating uranium product from the Purex process comprises addition of hydrazine to the product uranyl nitrate stream from the Purex process, which contains hexavalent (UO.sub.2.sup.2+) uranium and heptavalent technetium (TcO.sub.4 -). Technetium in the product stream is reduced and then complexed by the addition of oxalic acid (H.sub.2 C.sub.2 O.sub.4), and the Tc-oxalate complex is readily separated from the uranium by solvent extraction with 30 vol. % tributyl phosphate in n-dodecane.

  2. Surface selective membranes for carbon dioxide separation

    SciTech Connect

    Luebke, D.R.; Pennline, H.W.; Myers, C.R.

    2005-09-01

    In this study, hybrid membranes have been developed for the selective separation of CO2 from mixtures containing H2. Beginning with commercially available Pall alumina membrane tubes with nominal pore diameter of 5 nm, hybrids were produced by silation with a variety of functionalities designed to facilitate the selective adsorption of CO2 onto the pore surface. The goal is to produce a membrane which can harness the power of surface diffusion to give the selectivity of polymer membranes with the permeance of inorganic membranes.

  3. Fine particle separation by selective flocculation

    SciTech Connect

    Attia, Y.

    1982-01-01

    One of the most promising techniques for separating very small particulates is selective flocculation. A number of successful applications for selective flocculation have been demonstrated on laboratory and pilot-plant testing, but with only a few commercial applications. Understanding of the process parameters and potential applications is still at the early stages, and research is underway to develop this process for copper, coal, phosphate, and tin ores. Thus far, most of the applications of selective flocculation have been in minerals processing, where separation of the valuable minerals from associated waste rocks is the objective. But potential applications for selective flocculation also exist in other areas, such as the removal of heavy metal oxides from steel dusts and other hazardous incineration residues, separation of the impurities from ceramic mineral powders, the removal of opaque minerals from kaolin, and the recovery of values from secondary sources. In this article the methods involved in obtaining selective flocculation, examples of successful applications, recent developments, and future outlook for this technology are discussed.

  4. Regenerated Uranium Separation in Matched Abundance Ratio Cascade with Additional Product Flow

    NASA Astrophysics Data System (ADS)

    Maslyukov, E. V.; Palkin, V. A.

    2016-09-01

    This paper addresses known methods used to purify regenerated uranium in single and double cascades. A new method for separating regenerated uranium has been developed that enables a significant reduction of the concentration of 232,234U in the additional product flow. Matched abundance ratio cascades (M*-cascades) with different key components and additional product flow are used in the new method. Main product flow of the M*-cascade contains low enriched regenerated uranium. It can be used for reactor fuel production. Purified product can be enriched in the ordinary cascade in compliance with the requirements of ASTM C 996-10 set for isotopes 232,234U in low enriched commercial uranium, which is usually produced from the natural one. Computer experiment based on the new method has been performed. The experiment shows that the best cascade with the maximum flow of the enriched purified product is M*-cascade with key components 232,236U.

  5. SEPARATING URANIUM CONTAINING SOLIDS SUSPENDED IN A LIQUID

    DOEpatents

    Creutz, E.C.; Wigner, E.P.

    1958-05-01

    A process is described for separating uraniumcontaining solids suspended in a liquid. It consists of adding to the liquid a wetting agent for the U- containing solids in an amount sufficient to form a separate liquid phase, the wetting agent having a density greater than the density of the liquid. Ethyl dibromoacetate is noted as one preferred wetting agent.

  6. Separator profile selection for optimal battery performance

    NASA Astrophysics Data System (ADS)

    Whear, J. Kevin

    Battery performance, depending on the application, is normally defined by power delivery, electrical capacity, cycling regime and life in service. In order to meet the various performance goals, the Battery Design Engineer can vary things such as grid alloys, paste formulations, number of plates and methods of construction. Another design option available to optimize the battery performance is the separator profile. The goal of this paper is to demonstrate how separator profile selection can be utilized to optimize battery performance and manufacturing efficiencies. Also time will be given to explore novel separator profiles which may bring even greater benefits in the future. All major lead-acid application will be considered including automotive, motive power and stationary.

  7. Selective Recovery of Enriched Uranium from Inorganic Wastes

    SciTech Connect

    Kimura, R. T.

    2003-02-26

    Uranium as U(IV) and U(VI) can be selectively recovered from liquids and sludge containing metal precipitates, inorganic salts, sand and silt fines, debris, other contaminants, and slimes, which are very difficult to de-water. Chemical processes such as fuel manufacturing and uranium mining generate enriched and natural uranium-bearing wastes. This patented Framatome ANP (FANP) uranium recovery process reduces uranium losses, significantly offsets waste disposal costs, produces a solid waste that meets mixed-waste disposal requirements, and does not generate metal-contaminated liquids. At the head end of the process is a floating dredge that retrieves liquids, sludge, and slimes in the form of a slurry directly from the floor of a lined surface impoundment (lagoon). The slurry is transferred to and mixed in a feed tank with a turbine mixer and re-circulated to further break down the particles and enhance dissolution of uranium. This process uses direct steam injection and sodium hypochlorite addition to oxidize and dissolves any U(IV). Cellulose is added as a non-reactive filter aid to help filter slimes by giving body to the slurry. The slurry is pumped into a large recessed-chamber filter press then de-watered by a pressure cycle-controlled double-diaphragm pump. U(VI) captured in the filtrate from this process is then precipitated by conversion to U(IV) in another Framatome ANP-patented process which uses a strong reducing agent to crystallize and settle the U(IV) product. The product is then dewatered in a small filter press. To-date, over 3,000 Kgs of U at 3% U-235 enrichment were recovered from a 8100 m2 hypalon-lined surface impoundment which contained about 10,220 m3 of liquids and about 757 m3 of sludge. A total of 2,175 drums (0.208 m3 or 55 gallon each) of solid mixed-wastes have been packaged, shipped, and disposed. In addition, 9463 m3 of low-U liquids at <0.001 KgU/m3 were also further processed and disposed.

  8. Quantum criticality in selected uranium intermetallic and organometallic compounds

    NASA Astrophysics Data System (ADS)

    Nasreen, Farzana

    My thesis presents the studies of the bulk properties of materials that exhibit unusual low-temperature properties due to the proximity of a quantum-critical point (QCP), for which long-range magnetic order can be suppressed to 0 K as a consequence of quantum fluctuations. A material can be tuned to the QCP by variation of a non-thermal control parameter such as hydrostatic pressure, magnetic field and chemical pressure/doping. Most of my experimental studies were performed at extreme conditions, such as high magnetic fields, low temperatures and/or high pressures. Two classes of materials were studied, namely uranium intermetallics and organometallics. The investigations on uranium intermetallics were done on compounds close to the edge of magnetism, i.e. the UCu4+xAl 8-x, UCuxAl5-x and UFe1-xNixAl compounds. Several of those compounds exhibit deviations from traditional Fermi-liquid theory and show non-Fermi liquid (NFL) scaling at low temperatures. Field-induced magnetic transitions were studied for some selected uranium compounds (UNiAl, UNiGa, UNiGe and UIrGe) as well. Furthermore, a study of organometallic quantum magnet (DTN: NiCl2-4SC(NH 2)2), which exhibits field-induced quantum criticality, is presented. In DTN, the magnetic-field induced polarization shows magneto-electric couplings between the antiferromagnetic Ni spins and the soft organic lattice.

  9. Separation of tc from Uranium and development of metallic Technetium waste forms

    NASA Astrophysics Data System (ADS)

    Mausolf, Edward John

    The isotope Technetium-99 (99Tc) is a major fission product of the nuclear industry. In the last decade, approximately 20 tons of 99Tc have been produced by the US nuclear industry. Due to its long half-life (t1/2 = 214,000 yr), beta radiotoxicity, and high mobility as pertechnetate [TcO4]-, Tc represents long-term concern to the biosphere. Various options have been considered to manage 99Tc. One of them is its separation from spent fuel, conversion to the metal and incorporation into a metallic waste form for long-term disposal. After dissolution of spent fuel in nitric acid and extraction of U and Tc in organic media, previously developed methods can be used to separate Tc from U, convert the separate Tc stream to the metal and reuse the uranium component of the fuel. A variety of metallic waste forms, ranging from pure Tc metal to ternary Tc alloys combined with stainless steel (SS) and Zr are proposed. The goal of this work was to examine three major questions: What is the optimal method to separate Tc from U? After separation, what is the most efficient method to convert the Tc stream to Tc metal? Finally, what is the corrosion behavior of Tc metal, Tc-SS alloys and Tc-Zr-SS alloys in 0.01M NaCl? The goal is to predict the long term behavior of Tc metallic waste in a hypothetical storage environment. In this work, three methods have been used to separate Tc from U: anionic exchange resin, liquid-liquid extraction and precipitation. Of the three methods studied, anionic exchange resins is the most selective. After separation of Tc from U, three different methods were studied to convert the Tc stream to the metal: thermal treatment under hydrogen atmosphere, electrochemical and chemical reduction of pertechnetate in aqueous media. The thermal treatment of the Tc stream under hydrogen atmosphere is the preferred method to produce Tc metal. After Tc metal is isolated, it will be incorporated into a metal host phase. Three different waste forms were produced for

  10. Supercritical fluid extraction and separation of uranium from other actinides.

    PubMed

    Quach, Donna L; Mincher, Bruce J; Wai, Chien M

    2014-06-15

    The feasibility of separating U from nitric acid solutions of mixed actinides using tri-n-butylphosphate (TBP)-modified supercritical fluid carbon dioxide (sc-CO2) was investigated. The actinides U, Np, Pu, and Am were extracted into sc-CO2 modified with TBP from a range of nitric acid concentrations, in the absence of, or in the presence of, a number of traditional reducing and/or complexing agents to demonstrate the separation of these metals from U under sc-CO2 conditions. The separation of U from Pu using sc-CO2 was successful at nitric acid concentrations of less than 3M in the presence of acetohydroxamic acid (AHA) or oxalic acid (OA) to mitigate Pu extraction, and the separation of U from Np was successful at nitric acid concentrations of less than 1M in the presence of AHA, OA, or sodium nitrite to mitigate Np extraction. Americium was not well extracted under any condition studied.

  11. Enhanced Method for Molybdenum Separation and Isotopic Determination in Geological Samples and Uranium-Rich Materials

    NASA Astrophysics Data System (ADS)

    Migeon, V.; Bourdon, B.; Pili, E.

    2014-12-01

    Molybdenum (Mo) shares analogous geochemical properties with uranium. Mo ispresent as a minor or a trace element in uranium ores under two main oxidation states: +IVand +VI. Mo has seven stable isotopes (92, 94, 95, 96, 97, 98 and 100). In natural systems,Mo and Mo isotopes were shown to fractionate during redox reactions. Because Morepresents an impurity difficult to separate in the nuclear fuel cycle, it has the potential to beused as an indicator of the origins of uranium concentrates, in the framework of nuclearforensics. This work focuses on developing an enhanced separation method for Mo from auranium-rich matrix (uranium ore, uranium concentrate) in order to analyze the massfractionation induced by processes typical of the nuclear fuel cycle. Purification of Mo forisotope ratio measurements is performed with a three-step separation on ion-exchange resins,with yields between 45 and 82%. Matrix and isobaric interferences (Zr, Ru) were reduced ingeological and uranium standards, such as U/Mo ≤ 2*10-4, Zr/Mo ≤ 1*10-3, Ru/Mo ≤ 6*10-4and Fe/Mo ≤ 4*10-3. Mo isotopic compositions were measured on a Neptune Plus MC-ICPMSequipped with Jet cones, for a concentration of 30 ng/ml. The achieved sensitivity is~1200-1800 V/ppm with interferences below 10 mV and an overall reproducibility of 0.02 ‰on the δ98Mo values. A double spike, with 97Mo and 100Mo, was added to the samples beforethe purification. It allows for correction of the chemical and instrumental mass fractionations,without requiring a quantitative yield. For igneous rocks, δ98Mo values range between -0.55and -0.03 ‰, relative to the NIST-SRM 3134 molybdenum standard. Fractionation amonguranium ore concentrates is higher, with δ98Mo ranging between 0.02 and -2.84 ‰.

  12. DECONTAMINATION OF URANIUM

    DOEpatents

    Spedding, F.H.; Butler, T.A.

    1962-05-15

    A process is given for separating fission products from uranium by extracting the former into molten aluminum. Phase isolation can be accomplished by selectively hydriding the uranium at between 200 and 300 deg C and separating the hydride powder from coarse particles of fissionproduct-containing aluminum. (AEC)

  13. Investigation of the Photochemical Method for Uranium Isotope Separation

    DOE R&D Accomplishments Database

    Urey, H. C.

    1943-07-10

    To find a process for successful photochemical separation of isotopes several conditions have to be fulfilled. First, the different isotopes have to show some differences in the spectrum. Secondly, and equally important, this difference must be capable of being exploited in a photochemical process. Parts A and B outline the physical and chemical conditions, and the extent to which one might expect to find them fulfilled. Part C deals with the applicability of the process.

  14. SEPARATION OF URANIUM HEXAFLUORIDE FROM ORGANIC FLUORO COMPOUNDS

    DOEpatents

    Libby, W.F.

    1958-10-01

    A method is presented for removing perfiuoroorganic compounds such as C/ sub 7/F/sub 16/ from UF/sub 6/. The physical and chemical properties of the perfluoro compounds are such as to render their removal from UF/sub 6/ difficulty by conventional techniques. The mixture containing UF/sub 6/ and the perfluoro compounds is pyrolyzed in an inert container at high temperature and pressure. The properties of the products obtained by pyrolysis differ from the properties of UF/sub 6/ to a sufficient degree to render their separation possible by ordinary methods.

  15. THE RECOVERY OF URANIUM FROM GAS MIXTURE

    DOEpatents

    Jury, S.H.

    1964-03-17

    A method of separating uranium from a mixture of uranium hexafluoride and other gases is described that comprises bringing the mixture into contact with anhydrous calcium sulfate to preferentially absorb the uranium hexafluoride on the sulfate. The calcium sulfate is then leached with a selective solvent for the adsorbed uranium. (AEC)

  16. Dissolution of metal oxides and separation of uranium from lanthanides and actinides in supercritical carbon dioxide

    SciTech Connect

    Quach, D.L.; Wai, C.M.; Mincher, B.J.

    2013-07-01

    This paper investigates the feasibility of extracting and separating uranium from lanthanides and other actinides by using supercritical fluid carbon dioxide (sc-CO{sub 2}) as a solvent modified with tri-n-butylphosphate (TBP) for the development of a counter current stripping technique, which would be a more efficient and environmentally benign technology for spent nuclear fuel reprocessing compared to traditional solvent extraction. Several actinides (U, Pu, and Np) and europium were extracted in sc-CO{sub 2} modified with TBP over a range of nitric acid concentrations and then the actinides were exposed to reducing and complexing agents to suppress their extractability. According to this study, uranium/europium and uranium/plutonium extraction and separation in sc-CO{sub 2} modified with TBP is successful at nitric acid concentrations of less than 6 M and at nitric acid concentrations of less than 3 M with acetohydroxamic acid or oxalic acid, respectively. A scheme for recycling uranium from spent nuclear fuel by using sc-CO{sub 2} and counter current stripping columns is presented. (authors)

  17. Uranium and thorium sequential separation from norm samples by using a SIA system.

    PubMed

    Mola, M; Nieto, A; Peñalver, A; Borrull, F; Aguilar, C

    2014-01-01

    This study presents a sequential radiochemical separation method for uranium and thorium isotopes using a novel Sequential Injection Analysis (SIA) system with an extraction chromatographic resin (UTEVA). After the separation, uranium and thorium isotopes have been quantified by using alpha-particle spectrometry. The developed method has been tested by analyzing an intercomparison sample (phosphogypsum sample) from International Atomic Energy Agency (IAEA) with better recoveries for uranium and thorium than the obtained by using a classical method (93% for uranium using the new methodology and 82% with the classical method, and in the case of thorium the recoveries were 70% for the semi-automated method and 60% for the classical strategy). Afterwards, the method was successfully applied to different Naturally Occurring Radioactive Material (NORM) samples, in particular sludge samples taken from a drinking water treatment plant (DWTP) and also sediment samples taken from an area of influence of the dicalcium phosphate (DCP) factory located close to the Ebro river reservoir in Flix (Catalonia). The obtained results have also been compared with the obtained by the classical method and from that comparison it has been demonstrated that the presented strategy is a good alternative to existing methods offering some advantages as minimization of sample handling, reduction of solvents volume and also an important reduction of the time per analysis.

  18. DISSOLUTION OF METAL OXIDES AND SEPARATION OF URANIUM FROM LANTHANIDES AND ACTINIDES IN SUPERCRITICAL CARBON DIOXIDE

    SciTech Connect

    Donna L. Quach; Bruce J. Mincher; Chien M. Wai

    2013-10-01

    This paper investigates the feasibility of extracting and separating uranium from lanthanides and other actinides by using supercritical fluid carbon dioxide (sc-CO2) as a solvent modified with tri-n-butylphosphate (TBP) for the development of a counter current stripping technique, which would be a more efficient and environmentally benign technology for spent nuclear fuel reprocessing compared to traditional solvent extraction. Several actinides (U, Pu, and Np) and europium were extracted in sc-CO2 modified with TBP over a range of nitric acid concentrations and then the actinides were exposed to reducing and complexing agents to suppress their extractability. According to this study, uranium/europium and uranium/plutonium extraction and separation in sc-CO2 modified with TBP is successful at nitric acid concentrations of less than 6 M and at nitric acid concentrations of less than 3 M with acetohydroxamic acid or oxalic acid, respectively. A scheme for recycling uranium from spent nuclear fuel by using sc-CO2 and counter current stripping columns is presented.

  19. Application of diode lasers to the isotopically selective determination of uranium in oxides by optogalvanic spectroscopy

    NASA Astrophysics Data System (ADS)

    Young, J. P.; Barshick, C. M.; Shaw, R. W.; Ramsey, J. M.

    1995-04-01

    We have observed isotopically selective diode laser-excited optogalvanic effects in uranium at 778.42 and 776.10 nm. The samples were natural abundance uranium oxide, as well as depleted (0.3% 235U), natural (0.7% 235U) and enriched (9.75% 235U) uranium metal or powders. The measurements were carried out in a demountable-cathode glow discharge cell. Preliminary evaluations of precision for uranium isotopic ratios measured using this technique suggest that it should have broad analytical applications for uranium and other amenable actinides or lanthanides.

  20. Application of diode lasers to the isotopically selective determination of uranium in oxides by optogalvanic spectroscopy

    NASA Astrophysics Data System (ADS)

    Young, J. P.; Barshick, C. M.; Shaw, R. W.; Ramsey, J. M.

    We have observed isotopically selective diode laser-excited optogalvanic effects in uranium at 778.42 and 776.19 nm. The samples were natural abundance uranium oxide, as well as depleted (0.3% U-235), natural (0.7% U-235) and enriched (9.75% U-235) uranium metal or powders. The measurements were carried out in a demountable-cathode glow discharge cell. Preliminary evaluations of precision for uranium isotopic ratios measured using this technique suggest that it should have broad analytical applications for uranium and other amenable actinides or lanthanides.

  1. THE EFFECT OF BURNUP AND SEPARATION EFFICIENCY ON URANIUM UTILIZATION AND RADIOTOXICITY

    SciTech Connect

    Samuel Bays; Steven Piet

    2001-11-01

    This paper addresses two fundamental issues of fuel cycle sustainability. The two primary issues of interest are efficient use of the natural uranium resource (cradle), and management of nuclear waste radiotoxicity (grave). Both uranium utilization and radiotoxicity are directly influenced by the burnup achieved during irradiation (transmutation related) and where applicable the separation efficiency (partitioning related). Burnup influences the in-growth of transuranics by breeding them into the fuel cycle. Transuranic breeding is virtually essential to resource sustainability because it increases utilization of naturally abundant fertile U-238. However, the direct consequence of this build-up is the in-growth of transuranic isotopes which generally increase the source of future geologically committed radiotoxicity. For scenarios involving recycle, separation efficiency influences the degree to which this transuranic source term is removed from active service in the fuel stream and made a disposal legacy of human activity.

  2. Development of non-denaturing off-gel isoelectric focusing for the separation of uranium-protein complexes in fish.

    PubMed

    Bucher, Guillaume; Frelon, Sandrine; Simon, Olivier; Lobinski, Ryszard; Mounicou, Sandra

    2014-05-01

    An off-gel non-denaturing isoelectric focusing (IEF) method was developed to separate uranium-biomolecule complexes from biological samples as a first step in a multidimensional metalloproteomic approach. Analysis of a synthetic uranium-bovine serum albumin complex demonstrated the focusing ability of the liquid-phase IEF method and the preservation of most of the uranium-protein interactions. The developed method was applied to gill cytosol prepared from zebrafish (Danio rerio) exposed to depleted uranium. The results were compared in terms of resolution, recovery, and protein identities with those obtained by in-gel IEF using an immobilized pH gradient gel strip. PMID:24691723

  3. Analysis of civilian processing programs in reduction of excess separated plutonium and high-enriched uranium

    SciTech Connect

    Persiani, P.J.

    1995-12-31

    The purpose of this preliminary investigation is to explore alternatives and strategies aimed at the gradual reduction of the excess inventories of separated plutonium and high-enriched uranium (HEU) in the civilian nuclear power industry. The study attempts to establish a technical and economic basis to assist in the formation of alternative approaches consistent with nonproliferation and safeguards concerns. The analysis addresses several options in reducing the excess separated plutonium and HEU, and the consequences on nonproliferation and safeguards policy assessments resulting from the interacting synergistic effects between fuel cycle processes and isotopic signatures of nuclear materials.

  4. METHOD FOR SEPARATION OF PLUTONIUM FROM URANIUM AND FISSION PRODUCTS BY SOLVENT EXTRACTION

    DOEpatents

    Seaborg, G.T.; Blaedel, W.J.; Walling, M.T. Jr.

    1960-08-23

    A process is given for separating from each other uranium, plutonium, and fission products in an aqueous nitric acid solution by the so-called Redox process. The plutonium is first oxidized to the hexavalent state, e.g., with a water-soluble dichromate or sodium bismuthate, preferably together with a holding oxidant such as potassium bromate. potassium permanganate, or an excess of the oxidizing agent. The solution is then contacted with a water-immiscible organic solvent, preferably hexone. whereby uranium and plutonium are extracted while the fission products remain in the aqueous solution. The separated organic phase is then contacted with an aqueous solution of a reducing agent, with or without a holding reductant (e.g., with a ferrous salt plus hydrazine or with ferrous sulfamate), whereby plutonium is reduced to the trivalent state and back- extracted into the aqueous solution. The uranium may finally be back-extracted from the organic solvent (e.g., with a 0.1 N nitric acid).

  5. Direct Separation of Molybdenum from Solid Uranium Matrices Employing Pyrohydrolysis, a Green Separation Method, and Its Determination by Ion Chromatography.

    PubMed

    Mishra, Vivekchandra G; Thakur, Uday K; Shah, Dipti J; Gupta, Neeraj K; Jeyakumar, Subbiah; Tomar, Bhupendra S; Ramakumar, Karanam L

    2015-11-01

    Pyrohydrolysis is a well-established separation method, and it is being used as a sample preparation method for several materials for further determination of non-metals such as halogens, boron, and sulfur. Analytes are retained in a diluted solution that is suitable for carrying out analysis by several determination techniques and minimizing the use of concentrated reagents. Pyrohydrolysis separation of metals has not been reported yet. The present study demonstrates the pyrohydrolysis separation of Mo as MoO4(2-) from uranium materials and its subsequent determination using ion chromatography coupled with suppressed conductivity detector. With use of TGA and XRD the volatilization behavior of Mo was studied. Important parameters for the pyrohydrolysis method required for the quantitative separation of Mo were evaluated. The precision of the method was better than 5% at 25 ppm of Mo. The accuracy was evaluated by analysis of a CRM (U3O8-ILCE-IV). The method was applied to determine Mo in ammonium diuranate samples, where the conventional methods suffer from the loss of Mo.

  6. Direct Separation of Molybdenum from Solid Uranium Matrices Employing Pyrohydrolysis, a Green Separation Method, and Its Determination by Ion Chromatography.

    PubMed

    Mishra, Vivekchandra G; Thakur, Uday K; Shah, Dipti J; Gupta, Neeraj K; Jeyakumar, Subbiah; Tomar, Bhupendra S; Ramakumar, Karanam L

    2015-11-01

    Pyrohydrolysis is a well-established separation method, and it is being used as a sample preparation method for several materials for further determination of non-metals such as halogens, boron, and sulfur. Analytes are retained in a diluted solution that is suitable for carrying out analysis by several determination techniques and minimizing the use of concentrated reagents. Pyrohydrolysis separation of metals has not been reported yet. The present study demonstrates the pyrohydrolysis separation of Mo as MoO4(2-) from uranium materials and its subsequent determination using ion chromatography coupled with suppressed conductivity detector. With use of TGA and XRD the volatilization behavior of Mo was studied. Important parameters for the pyrohydrolysis method required for the quantitative separation of Mo were evaluated. The precision of the method was better than 5% at 25 ppm of Mo. The accuracy was evaluated by analysis of a CRM (U3O8-ILCE-IV). The method was applied to determine Mo in ammonium diuranate samples, where the conventional methods suffer from the loss of Mo. PMID:26465172

  7. Development of a Selective Calixarene Sensor for Uranium

    SciTech Connect

    Evans-Thompson, C.; Field, S. E.; Jones, A. H.; Kan, M. J.; Hall, C. W.; Nicholson, G. P.

    2002-02-26

    Traditionally, measurements of uranium in wastewater have been obtained by laboratory based instrumentation, such as inductively coupled plasma spectroscopy, ion-chromatography and radiochemical methods. However, such methods and equipment, whilst offering excellent sensitivity and reproducibility, are far too large and heavy to be portable. Therefore, there has been a lot of interest in developing a portable sensor to carry out uranium measurements. This work describes how a class of molecule called calixarenes have been used to develop a sensing methodology for measuring uranium concentration at low levels. This has been achieved by taking the established coordinating properties of the calixarene molecule for uranium and then adding functionalities to the molecule to make it adhere to metal surfaces. This way, a layer of the uranophilic molecule has been prepared on electrode surfaces, one molecule thick. These electrodes have been shown to be sensitive to uranium between 5 and 300 parts per billion. Using these modified electrodes, a portable device has been developed, which potentially allows for measurement of uranium in the field. This sensor therefore presents a very significant advantage in that it allows for rapid determination of low levels of uranium in wastewater, whilst offering portability.

  8. Studies on stannic selenoarsenate. II. Separation of uranium from numerous metal ions

    SciTech Connect

    Nabi, S.A.; Siddiqi, Z.M.; Rao, R.A.K.

    1982-12-01

    Stannic selenoarsenate has been synthesized by adding 0.05 M sodium selenite and 0.05 M sodium arsenate to a 0.05 M solution of stannic chloride in a volume ratio of 1:1:1 at pH 1. A tentative structure has been proposed on the basis of chemical composition, pH titrations, and infrared and thermogravimetric analyses. Distribution coefficients of several metal ions have been studied in hydrochloric acid, citric acid, ammonium citrate-citric acid, and water-dioxane systems. The unusual adsorption behavior or uranium has been utilized for its quantitative separation from several metal ions.

  9. Sample selection and testing of separation processes

    NASA Technical Reports Server (NTRS)

    Karr, L. J.

    1985-01-01

    Phase partitioning, which has become an important tool for the separation and purification of biological materials, was studied. Instruments available for this technique were researched and a countercurrent distribution apparatus, the Biosheff MK2N, was purchased. Various proteins, polysaccharides and cells were studied as models to determine operating procedures and conditions for this piece of equipment. Results were compared with those obtained from other similar equipment, including a nonsynchronous coil planet centrifuge device. Additionally, work was done with affinity ligands attached to PEG, which can further enhance the separation capabilities of phase partitioning.

  10. Innovative lasers for uranium isotope separation. Final report, September 1, 1989--April 1, 1993

    SciTech Connect

    Brake, M.L.; Gilgenbach, R.M.

    1993-07-01

    Copper vapor laser have important applications to uranium atomic vapor laser isotope separation (AVLIS). We have investigated two innovative methods of exciting/pumping copper vapor lasers which have the potential to improve the efficiency and scaling of large laser systems used in uranium isotope separation. Experimental research has focused on the laser discharge kinetics of (1) microwave, and (2) electron beam excitation/pumping of large-volume copper vapor lasers. Microwave resonant cavity produced copper vapor plasmas at 2.45 GHz, have been investigated in three separate experimental configurations. The first examined the application of CW (0-500W) power and was found to be an excellent method for producing an atomic copper vapor from copper chloride. The second used a pulsed (5kW, 0.5--5 kHz) signal superimposed on the CW signal to attempt to produce vaporization, dissociation and excitation to the laser states. Enhanced emission of the optical radiation was observed but power densities were found to be too low to achieve lasing. In a third experiment we attempted to increase the applied power by using a high power magnetron to produce 100 kW of pulsed power. Unfortunately, difficulties with the magnetron power supply were encountered leaving inconclusive results. Detailed modeling of the electromagnetics of the system were found to match the diagnostics results well. An electron beam pumped copper vapor system (350 kV, 1.0 kA, 300 ns) was investigated in three separate copper chloride heating systems, external chamber, externally heated chamber and an internally heated chamber. Since atomic copper spectral lines were not observed, it is assumed that a single pulse accelerator is not capable of both dissociating the copper chloride and exciting atomic copper and a repetitively pulsed electron beam generator is needed.

  11. Process for producing enriched uranium having a {sup 235}U content of at least 4 wt. % via combination of a gaseous diffusion process and an atomic vapor laser isotope separation process to eliminate uranium hexafluoride tails storage

    DOEpatents

    Horton, J.A.; Hayden, H.W. Jr.

    1995-05-30

    An uranium enrichment process capable of producing an enriched uranium, having a {sup 235}U content greater than about 4 wt. %, is disclosed which will consume less energy and produce metallic uranium tails having a lower {sup 235}U content than the tails normally produced in a gaseous diffusion separation process and, therefore, eliminate UF{sub 6} tails storage and sharply reduce fluorine use. The uranium enrichment process comprises feeding metallic uranium into an atomic vapor laser isotope separation process to produce an enriched metallic uranium isotopic mixture having a {sup 235} U content of at least about 2 wt. % and a metallic uranium residue containing from about 0.1 wt. % to about 0.2 wt. % {sup 235} U; fluorinating this enriched metallic uranium isotopic mixture to form UF{sub 6}; processing the resultant isotopic mixture of UF{sub 6} in a gaseous diffusion process to produce a final enriched uranium product having a {sup 235}U content of at least 4 wt. %, and up to 93.5 wt. % or higher, of the total uranium content of the product, and a low {sup 235}U content UF{sub 6} having a {sup 235}U content of about 0.71 wt. % of the total uranium content of the low {sup 235}U content UF{sub 6}; and converting this low {sup 235}U content UF{sub 6} to metallic uranium for recycle to the atomic vapor laser isotope separation process. 4 figs.

  12. Process for producing enriched uranium having a .sup.235 U content of at least 4 wt. % via combination of a gaseous diffusion process and an atomic vapor laser isotope separation process to eliminate uranium hexafluoride tails storage

    DOEpatents

    Horton, James A.; Hayden, Jr., Howard W.

    1995-01-01

    An uranium enrichment process capable of producing an enriched uranium, having a .sup.235 U content greater than about 4 wt. %, is disclosed which will consume less energy and produce metallic uranium tails having a lower .sup.235 U content than the tails normally produced in a gaseous diffusion separation process and, therefore, eliminate UF.sub.6 tails storage and sharply reduce fluorine use. The uranium enrichment process comprises feeding metallic uranium into an atomic vapor laser isotope separation process to produce an enriched metallic uranium isotopic mixture having a .sup.235 U content of at least about 2 wt. % and a metallic uranium residue containing from about 0.1 wt. % to about 0.2 wt. % .sup.235 U; fluorinating this enriched metallic uranium isotopic mixture to form UF.sub.6 ; processing the resultant isotopic mixture of UF.sub.6 in a gaseous diffusion process to produce a final enriched uranium product having a .sup.235 U content of at least 4 wt. %, and up to 93.5 wt. % or higher, of the total uranium content of the product, and a low .sup.235 U content UF.sub.6 having a .sup.235 U content of about 0.71 wt. % of the total uranium content of the low .sup.235 U content UF.sub.6 ; and converting this low .sup.235 U content UF.sub.6 to metallic uranium for recycle to the atomic vapor laser isotope separation process.

  13. Selective leaching of uranium from uranium-contaminated soils: Progress report 1

    SciTech Connect

    Francis, C.W.; Mattus, A.J.; Farr, L.L.; Elless, M.P.; Lee, S.Y.

    1993-02-01

    Three soils and a sediment contaminated with uranium were used to determine the effectiveness of sodium carbonate and citric acid leaching to decontaminated or remove uranium to acceptable regulatory levels. Two of the soils were surface soils from the DOE facility formerly called the Feed Materials Production Center (FMPC) at Fernald, Ohio. This facility is presently called the Femald Environmental Management Project (FEMP). Carbonate extractions generally removed from 70 to 90% of the uranium from the Fernald storage pad soil. Uranium was slightly more difficult to extract from the Fernald incinerator and the Y-12 landfarm soils. Very small amounts of uranium could be extracted from the storm sewer sediment. Extraction with carbonate at high solution-to-soil ratios were as effective as extractions at low solution-to-soil ratios, indicating attrition by the paddle mixer was not significantly different than that provided in a rotary extractor. Also, pretreatments such as milling or pulverizing the soil sample did not appear to increase extraction efficiency when carbonate extractions were carried out at elevated temperatures (60[degree]C) or long extraction times (23 h). Adding KMnO[sub 4] in the carbonate extraction appeared to increase extraction efficiency from the Fernald incinerator soil but not the Fernald storage pad soil. The most effective leaching rates (> 90 % from both Fernald soils) were obtained using a citrate/dithionite extraction procedure designed to remove amorphous (noncrystalline) iron/aluminum sesquioxides from surfaces of clay minerals. Citric acid also proved to be a very good extractant for uranium.

  14. Isotope separation by selective photodissociation of glyoxal

    DOEpatents

    Marling, John B.

    1976-01-01

    Dissociation products, mainly formaldehyde and carbon monoxide, enriched in a desired isotope of carbon, oxygen, or hydrogen are obtained by the selective photodissociation of glyoxal wherein glyoxal is subjected to electromagnetic radiation of a predetermined wavelength such that photon absorption excites and induces dissociation of only those molecules of glyoxal containing the desired isotope.

  15. Optimized Chemical Separation and Measurement by TE TIMS Using Carburized Filaments for Uranium Isotope Ratio Measurements Applied to Plutonium Chronometry.

    PubMed

    Sturm, Monika; Richter, Stephan; Aregbe, Yetunde; Wellum, Roger; Prohaska, Thomas

    2016-06-21

    An optimized method is described for U/Pu separation and subsequent measurement of the amount contents of uranium isotopes by total evaporation (TE) TIMS with a double filament setup combined with filament carburization for age determination of plutonium samples. The use of carburized filaments improved the signal behavior for total evaporation TIMS measurements of uranium. Elevated uranium ion formation by passive heating during rhenium signal optimization at the start of the total evaporation measurement procedure was found to be a result from byproducts of the separation procedure deposited on the filament. This was avoided using carburized filaments. Hence, loss of sample before the actual TE data acquisition was prevented, and automated measurement sequences could be accomplished. Furthermore, separation of residual plutonium in the separated uranium fraction was achieved directly on the filament by use of the carburized filaments. Although the analytical approach was originally tailored to achieve reliable results only for the (238)Pu/(234)U, (239)Pu/(235)U, and (240)Pu/(236)U chronometers, the optimization of the procedure additionally allowed the use of the (242)Pu/(238)U isotope amount ratio as a highly sensitive indicator for residual uranium present in the sample, which is not of radiogenic origin. The sample preparation method described in this article has been successfully applied for the age determination of CRM NBS 947 and other sulfate and oxide plutonium samples. PMID:27240571

  16. Optimized Chemical Separation and Measurement by TE TIMS Using Carburized Filaments for Uranium Isotope Ratio Measurements Applied to Plutonium Chronometry.

    PubMed

    Sturm, Monika; Richter, Stephan; Aregbe, Yetunde; Wellum, Roger; Prohaska, Thomas

    2016-06-21

    An optimized method is described for U/Pu separation and subsequent measurement of the amount contents of uranium isotopes by total evaporation (TE) TIMS with a double filament setup combined with filament carburization for age determination of plutonium samples. The use of carburized filaments improved the signal behavior for total evaporation TIMS measurements of uranium. Elevated uranium ion formation by passive heating during rhenium signal optimization at the start of the total evaporation measurement procedure was found to be a result from byproducts of the separation procedure deposited on the filament. This was avoided using carburized filaments. Hence, loss of sample before the actual TE data acquisition was prevented, and automated measurement sequences could be accomplished. Furthermore, separation of residual plutonium in the separated uranium fraction was achieved directly on the filament by use of the carburized filaments. Although the analytical approach was originally tailored to achieve reliable results only for the (238)Pu/(234)U, (239)Pu/(235)U, and (240)Pu/(236)U chronometers, the optimization of the procedure additionally allowed the use of the (242)Pu/(238)U isotope amount ratio as a highly sensitive indicator for residual uranium present in the sample, which is not of radiogenic origin. The sample preparation method described in this article has been successfully applied for the age determination of CRM NBS 947 and other sulfate and oxide plutonium samples.

  17. URANIUM RECOVERY PROCESS

    DOEpatents

    Kaufman, D.

    1958-04-15

    A process of recovering uranium from very low-grade ore residues is described. These low-grade uraniumcontaining hydroxide precipitates, which also contain hydrated silica and iron and aluminum hydroxides, are subjected to multiple leachings with aqueous solutions of sodium carbonate at a pH of at least 9. This leaching serves to selectively extract the uranium from the precipitate, but to leave the greater part of the silica, iron, and aluminum with the residue. The uranium is then separated from the leach liquor by the addition of an acid in sufficient amount to destroy the carbonate followed by the addition of ammonia to precipitate uranium as ammonium diuranate.

  18. Isotachophoretic separation of selected imidazolium ionic liquids.

    PubMed

    Kosobucki, Przemysław; Buszewski, Bogusław

    2008-02-15

    Results of determination of selected imidazolium ionic liquids by isotachophoresis (ITP) with conductometric detection was presented. The effects of the molar mass of different ionic liquids on electrophoretic mobility was observed. The presented method was validated and basic validation parameters were determined. Limit of detection (LOD) in a 10 and 25ng/L for anions and cations, respectively, is very satisfied. Thanks to its low cost and high rate, the presented method can be used in qualitative routine analysis as an alternative technique to liquid chromatography. PMID:18371834

  19. Separation Of Uranium And Plutonium Isotopes For Measurement By Multi Collector Inductively Coupled Plasma Mass Spectroscopy

    SciTech Connect

    Martinelli, R E; Hamilton, T F; Williams, R W; Kehl, S R

    2009-03-29

    Uranium (U) and plutonium (Pu) isotopes in coral soils, contaminated by nuclear weapons testing in the northern Marshall Islands, were isolated by ion-exchange chromatography and analyzed by mass spectrometry. The soil samples were spiked with {sup 233}U and {sup 242}Pu tracers, dissolved in minerals acids, and U and Pu isotopes isolated and purified on commercially available ion-exchange columns. The ion-exchange technique employed a TEVA{reg_sign} column coupled to a UTEVA{reg_sign} column. U and Pu isotope fractions were then further isolated using separate elution schemes, and the purified fractions containing U and Pu isotopes analyzed sequentially using multi-collector inductively coupled plasma mass spectrometer (MCICP-MS). High precision measurements of {sup 234}U/{sup 235}U, {sup 238}U/{sup 235}U, {sup 236}U/{sup 235}U, and {sup 240}Pu/{sup 239}Pu in soil samples were attained using the described methodology and instrumentation, and provide a basis for conducting more detailed assessments of the behavior and transfer of uranium and plutonium in the environment.

  20. EXTRACTION METHOD FOR SEPARATING URANIUM, PLUTONIUM, AND FISSION PRODUCTS FROM COMPOSITIONS CONTAINING SAME

    DOEpatents

    Seaborg, G.T.

    1957-10-29

    Methods for separating plutonium from the fission products present in masses of neutron irradiated uranium are reported. The neutron irradiated uranium is first dissolved in an aqueous solution of nitric acid. The plutonium in this solution is present as plutonous nitrate. The aqueous solution is then agitated with an organic solvent, which is not miscible with water, such as diethyl ether. The ether extracts 90% of the uraryl nitrate leaving, substantially all of the plutonium in the aqueous phase. The aqueous solution of plutonous nitrate is then oxidized to the hexavalent state, and agitated with diethyl ether again. In the ether phase there is then obtained 90% of plutonium as a solution of plutonyl nitrate. The ether solution of plutonyl nitrate is then agitated with water containing a reducing agent such as sulfur dioxide, and the plutonium dissolves in the water and is reduced to the plutonous state. The uranyl nitrate remains in the ether. The plutonous nitrate in the water may be recovered by precipitation.

  1. Separation and measurement of thorium, plutonium, americium, uranium and strontium in environmental matrices.

    PubMed

    Harrison, Jennifer J; Zawadzki, Atun; Chisari, Robert; Wong, Henri K Y

    2011-10-01

    A technique for the isolation of thorium (Th), plutonium (Pu), americium (Am), uranium (U) and strontium (Sr) isotopes from various environmental matrices has been adapted from a previously published method specific to water samples (Maxwell, 2006). Separation and isolation of the various elemental fractions from a single sub-sample is possible, thereby eliminating the need for multiple analyses. The technique involves sample dissolution, concentration via calcium phosphate co-precipitation, rapid column extraction using TEVA™, TRU™ and Sr-Spec™ resin cartridges, alpha spectrometry for Th, Pu, U and Am and Cerenkov counting for Sr. Various standard reference materials were analysed and chemical yields are in the range of 70-80% for Th, Am, U and Sr and 50-60% for Pu. Sample sizes of up to 10 L for water, 5 g for dry soil and sediment and 10 g for dry vegetation and seaweed can be processed using this technique.

  2. Rapid separation and purification of uranium and plutonium from dilute-matrix samples

    SciTech Connect

    Armstrong, Christopher R.; Ticknor, Brian W.; Hall, Gregory; Cadieux, James R.

    2014-03-11

    This work presents a streamlined separation and purification approach for trace uranium and plutonium from dilute (carrier-free) matrices. The method, effective for nanogram quantities of U and femtogram to picogram quantities of Pu, is ideally suited for environmental swipe samples that contain a small amount of collected bulk material. As such, it may be applicable for processing swipe samples such as those collected in IAEA inspection activities as well as swipes that are loaded with unknown analytes, such as those implemented in interlaboratory round-robin or proficiency tests. Additionally, the simplified actinide separation could find use in internal laboratory monitoring of clean room conditions prior to or following more extensive chemical processing. We describe key modifications to conventional techniques that result in a relatively rapid, cost-effective, and efficient U and Pu separation process. We demonstrate the efficacy of implementing anion exchange chromatography in a single column approach. We also show that hydrobromic acid is an effective substitute in lieu of hydroiodoic acid for eluting Pu. Lastly, we show that nitric acid is an effective digestion agent in lieu of perchloric acid and/or hydrofluoric acid. A step by step procedure of this process is detailed.

  3. Rapid separation and purification of uranium and plutonium from dilute-matrix samples

    DOE PAGES

    Armstrong, Christopher R.; Ticknor, Brian W.; Hall, Gregory; Cadieux, James R.

    2014-03-11

    This work presents a streamlined separation and purification approach for trace uranium and plutonium from dilute (carrier-free) matrices. The method, effective for nanogram quantities of U and femtogram to picogram quantities of Pu, is ideally suited for environmental swipe samples that contain a small amount of collected bulk material. As such, it may be applicable for processing swipe samples such as those collected in IAEA inspection activities as well as swipes that are loaded with unknown analytes, such as those implemented in interlaboratory round-robin or proficiency tests. Additionally, the simplified actinide separation could find use in internal laboratory monitoring ofmore » clean room conditions prior to or following more extensive chemical processing. We describe key modifications to conventional techniques that result in a relatively rapid, cost-effective, and efficient U and Pu separation process. We demonstrate the efficacy of implementing anion exchange chromatography in a single column approach. We also show that hydrobromic acid is an effective substitute in lieu of hydroiodoic acid for eluting Pu. Lastly, we show that nitric acid is an effective digestion agent in lieu of perchloric acid and/or hydrofluoric acid. A step by step procedure of this process is detailed.« less

  4. Engineering High-Fidelity Residue Separations for Selective Harvest

    SciTech Connect

    Kevin L. Kenney; Christopher T. Wright; Reed L. Hoskinson; J. Rochard Hess; David J. Muth, Jr.

    2006-07-01

    Composition and pretreatment studies of corn stover and wheat stover anatomical fractions clearly show that some corn and wheat stover anatomical fractions are of higher value than others as a biofeedstock. This premise, along with soil sustainability and erosion control concerns, provides the motivation for the selective harvest concept for separating and collecting the higher value residue fractions in a combine during grain harvest. This study recognizes the analysis of anatomical fractions as theoretical feedstock quality targets, but not as practical targets for developing selective harvest technologies. Rather, practical quality targets were established that identified the residue separation requirements of a selective harvest combine. Data are presented that shows that a current grain combine is not capable of achieving the fidelity of residue fractionation established by the performance targets. However, using a virtual engineering approach, based on an understanding of the fluid dynamics of the air stream separation, the separation fidelity can be significantly improved without significant changes to the harvester design. A virtual engineering model of a grain combine was developed and used to perform simulations of the residue separator performance. The engineered residue separator was then built into a selective harvest test combine, and tests performed to evaluate the separation fidelity. Field tests were run both with and without the residue separator installed in the test combine, and the chaff and straw residue streams were collected during harvest of Challis soft white spring wheat. The separation fidelity accomplished both with and without the residue separator was quantified by laboratory screening analysis. The screening results showed that the engineered baffle separator did a remarkable job of effecting high-fidelity separation of the straw and chaff residue streams, improving the chaff stream purity and increasing the straw stream yield.

  5. Methods for selective functionalization and separation of carbon nanotubes

    NASA Technical Reports Server (NTRS)

    Strano, Michael S. (Inventor); Usrey, Monica (Inventor); Barone, Paul (Inventor); Dyke, Christopher A. (Inventor); Tour, James M. (Inventor); Kittrell, W. Carter (Inventor); Hauge, Robert H (Inventor); Smalley, Richard E. (Inventor); Marek, legal representative, Irene Marie (Inventor)

    2011-01-01

    The present invention is directed toward methods of selectively functionalizing carbon nanotubes of a specific type or range of types, based on their electronic properties, using diazonium chemistry. The present invention is also directed toward methods of separating carbon nanotubes into populations of specific types or range(s) of types via selective functionalization and electrophoresis, and also to the novel compositions generated by such separations.

  6. Distribution of uranium and some selected trace metals in human scalp hair from Balkans.

    PubMed

    Zunic, Z S; Tokonami, S; Mishra, S; Arae, H; Kritsananuwat, R; Sahoo, S K

    2012-11-01

    The possible consequences of the use of depleted uranium (DU) used in Balkan conflicts in 1995 and 1999 for the people and the environment of this reason need attention. The heavy metal content in human hair may serve as a good indicator of dietary, environmental and occupational exposures to the metal compounds. The present work summarises the distribution of uranium and some selected trace metals such as Mn, Ni, Cu, Zn, Sr, Cd and Cs in the scalp hair of inhabitants from Balkans exposed to DU directly and indirectly, i.e. Han Pijesak, Bratoselce and Gornja Stubla areas. Except U and Cs, all other metals were compared with the worldwide reported values of occupationally unexposed persons. Uranium concentrations show a wide variation ranging from 0.9 ± 0.05 to 449 ± 12 µg kg(-1). Although hair samples were collected from Balkan conflict zones, uranium isotopic measurement ((235)U/(238)U) shows a natural origin rather than DU.

  7. Biometric approach in selecting plants for phytoaccumulation of uranium.

    PubMed

    Stojanović, Mirjana; Pezo, Lato; Lačnjevac, Časlav; Mihajlović, Marija; Petrović, Jelena; Milojković, Jelena; Stanojević, Marija

    2016-01-01

    This paper promotes the biometric classification system of plant cultivars, unique characteristics, in terms of the uranium (U) uptake, primarily in the function of the application for phytoremediation. It is known that the degree of adoption of U depends on the plant species and its morphological and physiological properties, but it is less known what impact have plants cultivars, sorts, and hybrids. Therefore, we investigated the U adoption in four cultivars of three plant species (corn, sunflower and soy bean). "Vegetation experiments were carried out in a plastic-house filled with soil (0.66 mgU) and with tailing (15.3 mgU kg(-1)) from closed uranium mine Gabrovnica-Kalna southeast of Serbia". Principal Component Analysis (PCA), Cluster Analysis (CA) and analysis of variance (ANOVA) were used for assessing the effect of different substrates cultivars, plant species and plant organs (root or shoot) on U uptake. Obtained results showed that a difference in U uptake by three investigated plant species depends not only of the type of substrate types and plant organs but also of their cultivars. Biometrics techniques provide a good opportunity for a better understanding the behavior of plants and obtaining much more useful information from the original data.

  8. Biometric approach in selecting plants for phytoaccumulation of uranium.

    PubMed

    Stojanović, Mirjana; Pezo, Lato; Lačnjevac, Časlav; Mihajlović, Marija; Petrović, Jelena; Milojković, Jelena; Stanojević, Marija

    2016-01-01

    This paper promotes the biometric classification system of plant cultivars, unique characteristics, in terms of the uranium (U) uptake, primarily in the function of the application for phytoremediation. It is known that the degree of adoption of U depends on the plant species and its morphological and physiological properties, but it is less known what impact have plants cultivars, sorts, and hybrids. Therefore, we investigated the U adoption in four cultivars of three plant species (corn, sunflower and soy bean). "Vegetation experiments were carried out in a plastic-house filled with soil (0.66 mgU) and with tailing (15.3 mgU kg(-1)) from closed uranium mine Gabrovnica-Kalna southeast of Serbia". Principal Component Analysis (PCA), Cluster Analysis (CA) and analysis of variance (ANOVA) were used for assessing the effect of different substrates cultivars, plant species and plant organs (root or shoot) on U uptake. Obtained results showed that a difference in U uptake by three investigated plant species depends not only of the type of substrate types and plant organs but also of their cultivars. Biometrics techniques provide a good opportunity for a better understanding the behavior of plants and obtaining much more useful information from the original data. PMID:26606604

  9. Evaluating the effectiveness of dilution of the recovered uranium with depleted uranium and low-enriched uranium to obtain fuel for VVER reactors

    NASA Astrophysics Data System (ADS)

    Smirnov, A. Yu; Sulaberidze, G. A.; Dudnikov, A. A.; Nevinitsa, V. A.

    2016-09-01

    The possibility of the recovered uranium enrichment in a cascade of gas centrifuges with three feed flows (depleted uranium, low-enriched uranium, recovered uranium) with simultaneous dilution of U-232,234,236 isotopes was shown. A series of numerical experiments were performed for different content of U-235 in low-enriched uranium. It has been demonstrated that the selected combination of diluents can simultaneously reduce the cost of separative work and the consumption of natural uranium, not only with respect to the previously used multi-flow cascade schemes, but also in comparison to the standard cascade for uranium enrichment.

  10. ELECTROLYSIS OF THORIUM AND URANIUM

    DOEpatents

    Hansen, W.N.

    1960-09-01

    An electrolytic method is given for obtaining pure thorium, uranium, and thorium-uranium alloys. The electrolytic cell comprises a cathode composed of a metal selected from the class consisting of zinc, cadmium, tin, lead, antimony, and bismuth, an anode composed of at least one of the metals selected from the group consisting of thorium and uranium in an impure state, and an electrolyte composed of a fused salt containing at least one of the salts of the metals selected from the class consisting of thorium, uranium. zinc, cadmium, tin, lead, antimony, and bismuth. Electrolysis of the fused salt while the cathode is maintained in the molten condition deposits thorium, uranium, or thorium-uranium alloys in pure form in the molten cathode which thereafter may be separated from the molten cathode product by distillation.

  11. Nonproliferation and safeguards aspects of fuel cycle programs in reduction of excess separated plutonium and high-enriched uranium

    SciTech Connect

    Persiani, P.J.

    1995-06-01

    The purpose of this preliminary investigation is to explore alternatives and strategies aimed at the gradual reduction of the excess inventories of separated plutonium and high-enriched uranium (HEU) in the civilian nuclear power industry. The study attempts to establish a technical and economic basis to assist in the formation of alternative approaches consistent with nonproliferation and safeguards concerns. Reference annual mass flows and inventories for a representative 1,400 Mwe Pressurized Water Reactor (PWR) fuel cycle have been investigated for three cases: the 100 percent uranium oxide UO{sub 2} fuel loading once through cycle, and the 33 percent mixed oxide MOX loading configuration for a first and second plutonium recycle. The analysis addresses fuel cycle developments; plutonium and uranium inventory and flow balances; nuclear fuel processing operations; UO{sub 2} once-through and MOX first and second recycles; and the economic incentives to draw-down the excess separated plutonium stores. The preliminary analysis explores several options in reducing the excess separated plutonium arisings and HEU, and the consequences of the interacting synergistic effects between fuel cycle processes and isotopic signatures of nuclear materials on nonproliferation and safeguards policy assessments.

  12. Chromatographic selectivity study of 4-fluorophenylacetic acid positional isomers separation.

    PubMed

    Chasse, Tyson; Wenslow, Robert; Bereznitski, Yuri

    2007-07-13

    Unique properties of the fluorine atom stimulate widespread use and development of new organofluorine compounds in agrochemistry, biotechnology and pharmacology applications. However, relatively few synthetic methods exhibit a high degree of fluorination selectivity, which ultimately results in the presence of structurally related fluorinated isomers in the synthetic product. This outcome is undesirable from a pharmaceutical perspective as positional isomers possess different reactivity, biological activity and toxicity as compared to the desired product. It is advantageous to control positional isomers in the early stages of the synthetic process, as rejection and analysis of these isomers will likely become more difficult in later stages. The current work reports the development of a chromatographic analysis of 2- and 3-fluorophenylacetic acid positional isomer impurities in 4-fluorophenylacetic acid (4-FPAA), a building block in the synthesis of an active pharmaceutical ingredient. The method is employed as a part of a Quality by Design Approach to control purity of the starting material in order to eliminate the presence of undesirable positional isomers in the final drug substance. During method development, a wide range of chromatographic conditions and structurally related positional isomer probe molecules were exploited in an effort to gain insight into the specifics of the separation mechanism. For the systems studied it was shown that the choice of organic modifier played a key role in achieving acceptable separation. Further studies encompassed investigation of temperature influence on retention and selectivity of the FPAA isomers separation. Thermodynamic analysis of these data showed that the selectivity of the 2- and 4- fluorophenylacetic acids separation was dominated by an enthalpic process, while the selectivity of the 4- and 3-fluorophenylacetic acids separation was exclusively entropy driven (Delta(DeltaH degrees approximately 0). Studies of

  13. pH effect on the separation of uranium fluoride effluents by the reverse osmosis process

    SciTech Connect

    Yun Chen ); Min-Lin Chu; Mu-Chang Shieh , Lung-tan, )

    1992-04-01

    Ammonium fluoride solutions and uranium fluoride effluents (UFE) with solute concentrations from 0.101 to 7,920 kg/m{sup 3}, at pH 2.80 to 9.60, have been treated with a continuous feedback reverse osmosis (RO) process. The solute rejections of NH{sub 4}{sup +}, F{sup {minus}}, and U{sup 6+} depend heavily on the feed pH value. For ammonium fluoride solutions, the rejection ratio of NH{sub 4}{sup +} decreases sharply from ca. 90 to 44.2% with the feed pH increased from 3.30 to 9.60, while that of F{sup {minus}} increases abruptly from 44.8 to 99.9% at the same pH change. For UFE solutions, the rejection ratio of U{sup 6+} remains greater than 90% at pH 2.80-7.13, while that of F{sup {minus}} decreases steadily from 96.4 to 18.8% with decreasing feed pH. Accordingly, the fluoride ions can be separated from UFE solutions under acidic conditions. The changes of solute rejection with feed pH can be explained by the different solubilities of the solutes in the membrane at different pH values. The UFE solutions with {alpha} and {beta} activities at 20.4-53.7 and 8.99-21.3 ({times} 10{sup 5} Baq/m{sup 3}) can be reduced to a level lower than 2.41 and 3.37 ({times}10{sup 5} Baq/m{sup 3}), respectively, by the current RO process.

  14. Separation of simple sugars by selectivity inverted parametric pumping

    SciTech Connect

    Sheng, P.; Costa, C.A.V.

    1998-12-01

    An alternative process to separate the isomeric mixture of fructose and glucose is presented. A laboratory study of a two-column, selectivity inverted, direct-mode parametric pump is reported. An anionic resin in carbonate form and a cationic resin in calcium form are used as adsorbents for the columns. The experimental results show that it is possible to simultaneously obtain separation and concentration with this system. A kinetic model assuming linear equilibrium, intraparticle pore diffusion, and axial dispersion is proposed and solved. The model solutions are compared with experimental results, and the comparisons indicate good prediction capabilities.

  15. Use of zirconium(IV) arsenophosphate columns for cation exchange separation of metal ions interfering in the spectrophotometric determination of uranium with sodium diethyl dithiocarbamate

    SciTech Connect

    Varshney, K.G.; Agrawal, S.; Anwar, S.; Varshney, K.

    1985-01-01

    A simple cation exchange method has been developed for the quantitative separation of uranium from some metal ions which generally interfere in its spectrophotometric determination using sodium diethyl dithiocarbamate as a reagent. The method requires only a single bed operation and enables a satisfactory (Error + or - separation of uranium (UO/sub 2/ (II)) up to 1080 ..mu..g from ten metal ions on a 2 g column of zirconium (IV) arsenophosphate cation exchanger in H(I) form.

  16. [Selection of Suitable Microalgal Species for Sorption of Uranium in Radioactive Wastewater Treatment].

    PubMed

    Li, Xin; Hu, Hong-ying; Yu, Jun-yi; Zhao, Wen-yu

    2016-05-15

    The amount of radioactive wastewater discharge was increasing year by year, with the quick development of nuclear industry. Therefore, the proper treatment and disposal of radioactive wastewater are essentially important for environmental safety and human health. Microalgal biosorption of nuclide has drawn much attention in the area of radioactive wastewater treatment recently, and the selection of a proper microalgal species for uranium biosorption is the basis for the research and application of this technology. The selection principle was set up from the view of practical application, and 11 species of microalgae were prepared for the selection work. Scenedesmus sp. LX1 has the highest biosorption capacity of 40.7 mg · g⁻¹ for uranium; and its biomass production in mBG11 medium (simulating the nitrogen and phosphorus limits in the first-class A discharge standard of pollutants for municipal wastewater treatment plant) was 0.32 g · L⁻¹, which was relatively high among the 11 microalgal species; when grown into stable phase it also showed a good precipitation capability with the precipitation ratio of 45.3%. Above all, in our selection range of the 11 microalgal species, Scenedesmus sp. LX1 could be considered as the suitable species for uranium biosorption in radioactive wastewater treatment. PMID:27506041

  17. [Selection of Suitable Microalgal Species for Sorption of Uranium in Radioactive Wastewater Treatment].

    PubMed

    Li, Xin; Hu, Hong-ying; Yu, Jun-yi; Zhao, Wen-yu

    2016-05-15

    The amount of radioactive wastewater discharge was increasing year by year, with the quick development of nuclear industry. Therefore, the proper treatment and disposal of radioactive wastewater are essentially important for environmental safety and human health. Microalgal biosorption of nuclide has drawn much attention in the area of radioactive wastewater treatment recently, and the selection of a proper microalgal species for uranium biosorption is the basis for the research and application of this technology. The selection principle was set up from the view of practical application, and 11 species of microalgae were prepared for the selection work. Scenedesmus sp. LX1 has the highest biosorption capacity of 40.7 mg · g⁻¹ for uranium; and its biomass production in mBG11 medium (simulating the nitrogen and phosphorus limits in the first-class A discharge standard of pollutants for municipal wastewater treatment plant) was 0.32 g · L⁻¹, which was relatively high among the 11 microalgal species; when grown into stable phase it also showed a good precipitation capability with the precipitation ratio of 45.3%. Above all, in our selection range of the 11 microalgal species, Scenedesmus sp. LX1 could be considered as the suitable species for uranium biosorption in radioactive wastewater treatment.

  18. Possibility of isotope separation by selective radiative scattering

    SciTech Connect

    Hutchinson, M.; George, T.F.; DeVries, P.L.

    1983-07-01

    It is demonstrated by means of a specific calculation that a velocity-changing radiative collision can lead to efficient isotope separation. Compared with photodissociative or photoionization techniques, selective scattering affords the advantage of a greater degree of control over the initial conditions, hence greater scope for optimization. This advantage is particularly important at the collision temperatures (approx.1 K), where radiative inelastic collisions are most efficient.

  19. Electrochemical separation of uranium in the molten system LiF-NaF-KF-UF4

    NASA Astrophysics Data System (ADS)

    Korenko, M.; Straka, M.; Szatmáry, L.; Ambrová, M.; Uhlíř, J.

    2013-09-01

    This article is focused on the electrochemical investigation (cyclic voltammetry and related studies) of possible reduction of U4+ ions to metal uranium in the molten system LiF-NaF-KF(eut.)-UF4 that can provide basis for the electrochemical extraction of uranium from molten salts. Two-step reduction mechanism for U4+ ions involving one electron exchange in soluble/soluble U4+/U3+ system and three electrons exchange in the second step were found on the nickel working electrode. Both steps were found to be reversible and diffusion controlled. Based on cyclic voltammetry, the diffusion coefficients of uranium ions at 530 °C were found to be D(U4+) = 1.64 × 10-5 cm2 s-1 and D(U3+) 1.76 × 10-5 cm2 s-1. Usage of the nickel spiral electrode for electrorefining of uranium showed fairly good feasibility of its extraction. However some oxidant present during the process of electrorefining caused that the solid deposits contained different uranium species such as UF3, UO2 and K3UO2F5.

  20. A Catalytic Beacon Sensor for Uranium with Parts-per-Trillion Sensitivity and Millionfold Selectivity

    SciTech Connect

    Liu, Juewen; Brown, Andrea K.; Meng, Xiangli; Cropek, Donald M.; IstokD., Jonathan; Watson, David B; Liu, Yi

    2007-01-01

    Here, we report a catalytic beacon sensor for uranyl (UO{sub 2}{sup 2+}) based on an in vitro-selected UO{sub 2}{sup 2+}-specific DNAzyme. The sensor consists of a DNA enzyme strand with a 3' quencher and a DNA substrate with a ribonucleotide adenosine (rA) in the middle and a fluorophore and a quencher at the 5' and 3' ends, respectively. The presence of UO{sub 2}{sup 2+} causes catalytic cleavage of the DNA substrate strand at the rA position and release of the fluorophore and thus dramatic increase of fluorescence intensity. The sensor has a detection limit of 11 parts per trillion (45 pM), a dynamic range up to 400 nM, and selectivity of >1-million-fold over other metal ions. The most interfering metal ion, Th(IV), interacts with the fluorescein fluorophore, causing slightly enhanced fluorescence intensity, with an apparent dissociation constant of {approx}230 {micro}M. This sensor rivals the most sensitive analytical instruments for uranium detection, and its application in detecting uranium in contaminated soil samples is also demonstrated. This work shows that simple, cost-effective, and portable metal sensors can be obtained with similar sensitivity and selectivity as much more expensive and sophisticated analytical instruments. Such a sensor will play an important role in environmental remediation of radionuclides such as uranium.

  1. A catalytic beacon sensor for uranium with parts-per-trillion sensitivity and millionfold selectivity.

    PubMed

    Liu, Juewen; Brown, Andrea K; Meng, Xiangli; Cropek, Donald M; Istok, Jonathan D; Watson, David B; Lu, Yi

    2007-02-13

    Here, we report a catalytic beacon sensor for uranyl (UO2(2+)) based on an in vitro-selected UO2(2+)-specific DNAzyme. The sensor consists of a DNA enzyme strand with a 3' quencher and a DNA substrate with a ribonucleotide adenosine (rA) in the middle and a fluorophore and a quencher at the 5' and 3' ends, respectively. The presence of UO2(2+) causes catalytic cleavage of the DNA substrate strand at the rA position and release of the fluorophore and thus dramatic increase of fluorescence intensity. The sensor has a detection limit of 11 parts per trillion (45 pM), a dynamic range up to 400 nM, and selectivity of >1-million-fold over other metal ions. The most interfering metal ion, Th(IV), interacts with the fluorescein fluorophore, causing slightly enhanced fluorescence intensity, with an apparent dissociation constant of approximately 230 microM. This sensor rivals the most sensitive analytical instruments for uranium detection, and its application in detecting uranium in contaminated soil samples is also demonstrated. This work shows that simple, cost-effective, and portable metal sensors can be obtained with similar sensitivity and selectivity as much more expensive and sophisticated analytical instruments. Such a sensor will play an important role in environmental remediation of radionuclides such as uranium.

  2. An improved extraction chromatographic resin for the separation of uranium from acidic nitrate media.

    PubMed

    Dietz, M L; Horwitz, E P; Sajdak, L R; Chiarizia, R

    2001-07-01

    The preparation and characterization of a new extraction chromatographic resin exhibiting extraordinarily strong retention of hexavalent uranyl ion over a wide range of nitric acid concentrations and very high selectivity for U(VI) over Fe(III) and numerous other cations is described. This new material (designated U/TEVA-2) comprises a novel liquid stationary phase consisting of an equimolar mixture of diamyl amylphosphonate (DA[AP]) and Cyanex 923((R)) (a commercially available trialkyl-phosphine oxide, TRPO) sorbed on silanized silica or Amberchrom CG-71. Cyanex 923 is shown to be preferable to a related TRPO, Cyanex 925((R)), due to its lower viscosity and higher selectivity for U(VI) over Fe(III). The retention of uranyl nitrate by the U/TEVA-2 resin, as measured by the k' values (number of free column values to peak maximum) is >5000 from approximately 0.1 to 8 M HNO(3). The ability of the new resin to strongly and selectively retain U(VI) from such a wide range of acid concentrations, along with its favorable physical properties, make it a good candidate for application in the separation and preconcentration of U(VI) from complex environmental, biological, and nuclear waste samples for subsequent determination.

  3. How Many Separable Sources? Model Selection In Independent Components Analysis

    PubMed Central

    Woods, Roger P.; Hansen, Lars Kai; Strother, Stephen

    2015-01-01

    Unlike mixtures consisting solely of non-Gaussian sources, mixtures including two or more Gaussian components cannot be separated using standard independent components analysis methods that are based on higher order statistics and independent observations. The mixed Independent Components Analysis/Principal Components Analysis (mixed ICA/PCA) model described here accommodates one or more Gaussian components in the independent components analysis model and uses principal components analysis to characterize contributions from this inseparable Gaussian subspace. Information theory can then be used to select from among potential model categories with differing numbers of Gaussian components. Based on simulation studies, the assumptions and approximations underlying the Akaike Information Criterion do not hold in this setting, even with a very large number of observations. Cross-validation is a suitable, though computationally intensive alternative for model selection. Application of the algorithm is illustrated using Fisher's iris data set and Howells' craniometric data set. Mixed ICA/PCA is of potential interest in any field of scientific investigation where the authenticity of blindly separated non-Gaussian sources might otherwise be questionable. Failure of the Akaike Information Criterion in model selection also has relevance in traditional independent components analysis where all sources are assumed non-Gaussian. PMID:25811988

  4. Evaluation of polymer inclusion membranes containing crown ethers for selective cesium separation from nuclear waste solution.

    PubMed

    Mohapatra, P K; Lakshmi, D S; Bhattacharyya, A; Manchanda, V K

    2009-09-30

    Transport behaviour of (137)Cs from nitric acid feed was investigated using cellulose triacetate plasticized polymer inclusion membrane (PIM) containing several crown ether carriers viz. di-benzo-18-crown-6 (DB18C6), di-benzo-21-crown-7 (DB21C7) and di-tert-butylbenzo-18-crown-6 (DTBB18C6). The PIM was prepared from cellulose triacetate (CTA) with various crown ethers and plasticizers. DTBB18C6 and tri-n-butyl phosphate (TBP) were found to give higher transport rate for (137)Cs as compared to other carriers and plasticizers. Effect of crown ether concentration, nitric acid concentration, plasticizer and CTA concentration on the transport rate of Cs was also studied. The Cs selectivity with respect to various fission products obtained from an irradiated natural uranium target was found to be heavily dependent on the nature of the plasticizer. The present work shows that by choosing a proper plasticizer, one can get either good transport efficiency or selectivity. Though TBP plasticized membranes showed good transport efficiency, it displayed poor selectivities. On the other hand, an entirely opposite separation behaviour was observed with 2-nitrophenyloctylether (NPOE) plasticized membranes suggesting the possible application of the later membranes for the removal of bulk (137)Cs from the nuclear waste. The stability of the membrane was tested by carrying out transport runs for nearly 25 days.

  5. Selectivity trend of gas separation through nanoporous graphene

    SciTech Connect

    Liu, Hongjun; Chen, Zhongfang; Dai, Sheng; Jiang, De-en

    2015-04-15

    By means of molecular dynamics (MD) simulations, we demonstrate that porous graphene can efficiently separate gases according to their molecular sizes. The flux sequence from the classical MD simulation is H{sub 2}>CO{sub 2}≫N{sub 2}>Ar>CH{sub 4}, which generally follows the trend in the kinetic diameters. This trend is also confirmed from the fluxes based on the computed free energy barriers for gas permeation using the umbrella sampling method and kinetic theory of gases. Both brute-force MD simulations and free-energy calcualtions lead to the flux trend consistent with experiments. Case studies of two compositions of CO{sub 2}/N{sub 2} mixtures further demonstrate the separation capability of nanoporous graphene. - Graphical abstract: Classical molecular dynamics simulations show the flux trend of H{sub 2}>CO{sub 2}≫N{sub 2}>Ar>CH{sub 4} for their permeation through a porous graphene, in excellent agreement with a recent experiment. - Highlights: • Classical MD simulations show the flux trend of H{sub 2}>CO{sub 2}≫N{sub 2}>Ar>CH{sub 4} for their permeation through a porous graphene. • Free energy calculations yield permeation barriers for those gases. • Selectivities for several gas pairs are estimated from the free-energy barriers and the kinetic theory of gases. • The selectivity trend is in excellent agreement with a recent experiment.

  6. Anion Separation by Selective Crystallization of Metal-Organic-Frameworks

    SciTech Connect

    Custelcean, Radu

    2006-01-01

    A novel approach for the separation of anions from aqueous mixtures was demonstrated, which involves their selective crystallization with metal-organic frameworks (MOFs) containing urea functional groups. Self-assembly of Zn{sup 2+} with the N,N{prime}-bis(m-pyridyl)urea (BPU) linker results in the formation of one-dimensional MOFs including various anions for charge balance, which interact to different extents with the zinc nodes and the urea hydrogen-bonding groups, depending on their coordinating abilities. Thus, Cl{sup -}, Br{sup -}, I{sup -}, and SO{sub 4}{sup 2-}, in the presence of BPU and Zn{sup 2+}, form MOFs from water, in which the anions coordinate the zinc and are hydrogen-bonded to the urea groups, whereas NO{sub 3}{sup -} and ClO{sub 4}{sup -} anions either do not form MOFs or form water-soluble discrete coordination complexes under the same conditions. X-ray diffraction, FTIR, and elemental analysis of the coordination polymers precipitated from aqueous mixtures containing equivalent amounts of these anions indicated total exclusion of the oxoanions and selective crystallization of the halides in the form of solid solutions with the general composition ZnCl{sub x}Br{sub y}I{sub z} {center_dot} BPU (x + y + z = 2), with an anti-Hofmeister selectivity. The concomitant inclusion of the halides in the same structural frameworks facilitates the rationalization of the observed selectivity on the basis of the diminishing interactions with the zinc and urea acidic centers in the MOFs when going from Cl{sup -} to I{sup -}, which correlates with decreasing anionic charge density in the same order. The overall crystal packing efficiency of the coordination frameworks, which ultimately determines their solubility, also plays an important role in the anion crystallization selectivity under thermodynamic equilibration.

  7. Feature Subset Selection, Class Separability, and Genetic Algorithms

    SciTech Connect

    Cantu-Paz, E

    2004-01-21

    The performance of classification algorithms in machine learning is affected by the features used to describe the labeled examples presented to the inducers. Therefore, the problem of feature subset selection has received considerable attention. Genetic approaches to this problem usually follow the wrapper approach: treat the inducer as a black box that is used to evaluate candidate feature subsets. The evaluations might take a considerable time and the traditional approach might be unpractical for large data sets. This paper describes a hybrid of a simple genetic algorithm and a method based on class separability applied to the selection of feature subsets for classification problems. The proposed hybrid was compared against each of its components and two other feature selection wrappers that are used widely. The objective of this paper is to determine if the proposed hybrid presents advantages over the other methods in terms of accuracy or speed in this problem. The experiments used a Naive Bayes classifier and public-domain and artificial data sets. The experiments suggest that the hybrid usually finds compact feature subsets that give the most accurate results, while beating the execution time of the other wrappers.

  8. Selective ion exchange recovery of rare earth elements from uranium mining solutions

    NASA Astrophysics Data System (ADS)

    Rychkov, Vladimir N.; Kirillov, Evgeny V.; Kirillov, Sergey V.; Bunkov, Grigory M.; Mashkovtsev, Maxim A.; Botalov, Maxim S.; Semenishchev, Vladimir S.; Volkovich, Vladimir A.

    2016-09-01

    A comparative study of rare earth, ferric and aluminum ions ion exchange behavior on gel sulfonated p;olystyrene cation exchange resins depending on the degree of the matrix cross-linking and pH of the solution is presented. Selective ion exchange of REEs is possible at the pH range of 1.5-2.0 using strongly acidic cation exchange resins containing more than 8 % of DVB. The preliminary results of testing the efficiency of REEs recovery from the industrial uranium underground leaching solutions are also presented.

  9. Method for producing a selectively permeable separation module

    DOEpatents

    Stone, Mark L.; Orme, Christopher J.; Peterson, Eric S.

    2000-03-14

    A method and apparatus is provided for casting a polymeric membrane on the inside surface of porous tubes to provide a permeate filter system capable of withstanding hostile operating conditions and having excellent selectivity capabilities. Any polymer in solution, by either solvent means or melt processing means, is capable of being used in the present invention to form a thin polymer membrane having uniform thickness on the inside surface of a porous tube. Multiple tubes configured as a tubular module can also be coated with the polymer solution. By positioning the longitudinal axis of the tubes in a substantially horizontal position and rotating the tube about the longitudinal axis, the polymer solution coats the inside surface of the porous tubes without substantially infiltrating the pores of the porous tubes, thereby providing a permeate filter system having enhanced separation capabilities.

  10. Geological and geochemical aspects of uranium deposits. A selected, annotated bibliography

    SciTech Connect

    Garland, P.A.; Thomas, J.M.; Brock, M.L.; Daniel, E.W.

    1980-06-01

    A bibliography of 479 references encompassing the fields of uranium and thorium geochemistry and mineralogy, geology of uranium deposits, uranium mining, and uranium exploration techniques has been compiled by the Ecological Sciences Information Center of Oak Ridge National Laboratory. The bibliography was produced for the National Uranium Resource Evaluation Program, which is funded by the Grand Junction Office of the Department of Energy. The references contained in the bibliography have been divided into the following eight subject categories: (1) geology of deposits, (2) geochemistry, (3) genesis O deposits, (4) exploration, (5) mineralogy, (6) uranium industry, (7) reserves and resources, and (8) geology of potential uranium-bearing areas. All categories specifically refer to uranium and thorium; the last category contains basic geologic information concerning areas which the Grand Junction Office feels are particularly favorable for uranium deposition. The references are indexed by author, geographic location, quadrangle name, geoformational feature, taxonomic name, and keyword.

  11. Selected annotated bibliography of the geology and occurrence of uranium-bearing marine black shales in the United States

    USGS Publications Warehouse

    Fix, Carolyn E.

    1956-01-01

    The bibliography consists of annotations or abstracts of selected reports that pertain to the geology and occurrence of uranium in marine black shales and their metamorphic equivalents in the United States. Only those reports that were available to the public prior to June 30, 1956, are included. Most of the reports may be consulted in the larger public, university, or scientific libraries. A few reports that have been released to the public in open file may be consulted at designated offices of the Geological Survey. An effort has been made to include only those references to shales whose uranium is believed to be of syngenetic origin and whose major source of radioactivity is uranium. Many general papers on the geology of uranium deposits refer to marine black shales, and some of these general papers have been included.

  12. "Stereoscopic" 2D super-microporous phosphazene-based covalent organic framework: Design, synthesis and selective sorption towards uranium at high acidic condition.

    PubMed

    Zhang, Shuang; Zhao, Xiaosheng; Li, Bo; Bai, Chiyao; Li, Yang; Wang, Lei; Wen, Rui; Zhang, Meicheng; Ma, Lijian; Li, Shoujian

    2016-08-15

    So far, only five primary elements (C, H, O, N and B) and two types of spatial configuration (C2-C4, C6 and Td) are reported to build the monomers for synthesis of covalent organic frameworks (COFs), which have partially limited the route selection for accessing COFs with new topological structure and novel properties. Here, we reported the design and synthesis of a new "stereoscopic" 2D super-microporous phosphazene-based covalent organic framework (MPCOF) by using hexachorocyclotriphosphazene (a P-containing monomer in a C3-like spatial configuration) and p-phenylenediamine (a linker). The as-synthesized MPCOF shows high crystallinity, relatively high heat and acid stability and distinctive super-microporous structure with narrow pore-size distributions ranging from 1.0-2.1nm. The results of batch sorption experiments with a multi-ion solution containing 12 co-existing cations show that in the pH range of 1-2.5, MPCOF exhibits excellent separation efficiency for uranium with adsorption capacity more than 71mg/g and selectivity up to record-breaking 92%, and furthermore, an unreported sorption capacity (>50mg/g) and selectivity (>60%) were obtained under strong acidic condition (1M HNO3). Studies on sorption mechanism indicate that the uranium separation by MPCOF in acidic solution is realized mainly through both intra-particle diffusion and size-sieving effect. PMID:27107239

  13. "Stereoscopic" 2D super-microporous phosphazene-based covalent organic framework: Design, synthesis and selective sorption towards uranium at high acidic condition.

    PubMed

    Zhang, Shuang; Zhao, Xiaosheng; Li, Bo; Bai, Chiyao; Li, Yang; Wang, Lei; Wen, Rui; Zhang, Meicheng; Ma, Lijian; Li, Shoujian

    2016-08-15

    So far, only five primary elements (C, H, O, N and B) and two types of spatial configuration (C2-C4, C6 and Td) are reported to build the monomers for synthesis of covalent organic frameworks (COFs), which have partially limited the route selection for accessing COFs with new topological structure and novel properties. Here, we reported the design and synthesis of a new "stereoscopic" 2D super-microporous phosphazene-based covalent organic framework (MPCOF) by using hexachorocyclotriphosphazene (a P-containing monomer in a C3-like spatial configuration) and p-phenylenediamine (a linker). The as-synthesized MPCOF shows high crystallinity, relatively high heat and acid stability and distinctive super-microporous structure with narrow pore-size distributions ranging from 1.0-2.1nm. The results of batch sorption experiments with a multi-ion solution containing 12 co-existing cations show that in the pH range of 1-2.5, MPCOF exhibits excellent separation efficiency for uranium with adsorption capacity more than 71mg/g and selectivity up to record-breaking 92%, and furthermore, an unreported sorption capacity (>50mg/g) and selectivity (>60%) were obtained under strong acidic condition (1M HNO3). Studies on sorption mechanism indicate that the uranium separation by MPCOF in acidic solution is realized mainly through both intra-particle diffusion and size-sieving effect.

  14. Plutonium-uranium separation in the Purex process using mixtures of hydroxylamine nitrate and ferrous sulfamate

    SciTech Connect

    McKibben, J.M.; Chostner, D.F.; Orebaugh, E.G.

    1983-11-01

    Laboratory studies, followed by plant operation, established that a mixture of hydroxylamine nitrate (HAN) and ferrous sulfamate (FS) is superior to FS used alone as a reductant for plutonium in the Purex first cycle. FS usage has been reduced by about 70% (from 0.12 to 0.04M) compared to the pre-1978 period. This reduced the volume of neutralized waste due to FS by 194 liters/metric ton of uranium (MTU) processed. The new flowsheet also gives lower plutonium losses to waste and at least comparable fission product decontamination. To achieve satisfactory performance at this low concentration of FS, the acidity in the 1B mixer-settler was reduced by using a split-scrub - a low acid scrub in stage one and a higher acid scrub in stage three - to remove acid from the solvent exiting the 1A centrifugal contactor. 8 references, 14 figures, 1 table.

  15. Innovative lasers for uranium isotope separation. Progress report for the period September 1, 1989--May 31, 1990

    SciTech Connect

    Brake, M.L.; Gilgenbach, R.M.

    1990-06-01

    Copper vapor lasers have important applications to uranium atomic vapor laser isotope separation (AVLIS). The authors have spent the first year of the project investigating two innovative methods of exciting/pumping copper vapor lasers which have the potential to improve the efficiency and scaling of large laser systems used in uranium isotope separation. Experimental research has focused on the laser discharge kinetics of (1) microwave and (2) electron beam excitation/pumping of large-volume copper vapor lasers. During the first year, the experiments have been designed and constructed and initial data has been taken. Highlights of some of the first year results as well as plans for the future include the following: Microwave resonant cavity produced copper vapor plasmas at 2.45 GHz, both pulsed (5 kW, 5kHz) and CW (0--500 Watts) have been investigated using heated copper chloride as the copper source. The visible emitted light has been observed and intense lines at 510.6 nm and 578.2 nm have been observed. Initial measurements of the electric field strengths have been taken with probes, the plasma volume has been measured with optical techniques, and the power has been measured with power meters. A self-consistent electromagnetic model of the cavity/plasma system which uses the above data as input shows that the copper plasma has skin depths around 100 cm, densities around 10{sup 12} {number_sign}/cc, collisional frequencies around 10{sup 11}/sec., conductivities around 0.15 (Ohm-meter){sup {minus}1}. A simple model of the heat transfer predicts temperatures of {approximately}900 K. All of these parameters indicate that microwave discharges may be well suited as a pump source for copper lasers. These preliminary studies will be continued during the second year with additional diagnostics added to the system to verify the model results. Chemical kinetics of the system will also be added to the model.

  16. Source separation, selective collection and in reactor digestion of biowaste.

    PubMed

    Gellens, V; Boelens, J; Verstraete, W

    1995-01-01

    Biowaste or the organic fraction of domestic waste, for instance kitchen, fruit and garden waste, is collected selectively in several European communities. The complementary fraction is called the dry or non recyclable fraction. A Dutch study reported that 92% of the participants that have a weekly collection service of both fractions (biowaste and non recyclable fraction) and 80% of the participants in the alternating collection program (one week biowaste and the next week non recyclable fraction) are pleased with separate collection of biowaste. Dominating problems that arise in case of alternating collection are a repulsive odor and an infestation with flies and maggots. By expanding the definition of biowaste to include non recyclable or soiled paper like dirty newspapers, table napkins and paper handkerchiefs, most of these problems can be overcome without changing the way compostable waste is collected and processed. The expanded definition of biowaste was used in this paper. Over a 12 month period a quality survey of the collected biowaste was conducted by the composting facility Intercompost, Hoeselt, Belgium. A special aspect was the fact that in one participating community baby diapers were included in the soiled paper fraction; this is called "biowaste+". The biowaste+ had a 10% non recyclable paper fraction opposed to only 1-2% of non recyclable paper present in the conventional biowaste. Baby diapers were a rather notable part (more than 80%) of this non recyclable paper fraction of biowaste+ and as a consequence might contribute to a large extent to improve the collection and treatment of biowaste. It was demonstrated that rural districts yielded about 35% more biowaste than more urban districts; resp. +/- 122 kg biowaste/capita. year versus +/- 90 kg biowaste/capita. year. In Hoeselt the biowaste+ yield was about 130 kg/capita.year. Biowaste+ is also separately collected in another Belgium community, namely Brecht. The purity level of the biowaste

  17. Selected Hanford reactor and separations operating data for 1960--1964. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Gydesen, S.P.

    1992-09-01

    The purpose of this letter report is to reconstruct from available information that data which can be used to develop daily reactor operating history for 1960--1964. The information needed for source team calculations (as determined by the Source Terms Task Leader) were extracted and included in this report. The data on the amount of uranium dissolved by the separations plants (expressed both as tons and as MW) is also included in this compilation.

  18. Selected Hanford reactor and separations operating data for 1960--1964

    SciTech Connect

    Gydesen, S.P.

    1992-09-01

    The purpose of this letter report is to reconstruct from available information that data which can be used to develop daily reactor operating history for 1960--1964. The information needed for source team calculations (as determined by the Source Terms Task Leader) were extracted and included in this report. The data on the amount of uranium dissolved by the separations plants (expressed both as tons and as MW) is also included in this compilation.

  19. Biomonitoring of environmental pollution by thorium and uranium in selected regions of the Republic of Kazakhstan.

    PubMed

    Zoriy, P; Ostapczuk, P; Dederichs, H; Höbig, J; Lennartz, R; Zoriy, M

    2010-05-01

    Two former uranium mines and a uranium reprocessing factory in the city of Aktau, Kazakhstan, may represent a risk of contaminating the surrounding areas by uranium and its daughter elements. One of the possible fingerprinting tools for studying the environmental contamination is using plant samples, collected in the surroundings of this city in 2007 and 2008. The distribution pattern of environmental pollution by uranium and thorium was evaluated by determining the thorium and uranium concentrations in plant samples (Artemisia austriaca) from the city of Aktau and comparing these results with those obtained for the same species of plants from an unpolluted area (town of Kurchatov). The determination of the uranium and thorium concentrations in different parts of A. austriaca plants collected from the analyzed areas demonstrated that the main contamination of the flora in areas surrounding the city of Aktau was due to dust transported by the wind from the uranium mines. The results obtained demonstrate that all the areas surrounding Aktau have a higher pollution level due to thorium and uranium than the control area (Kurchatov). A few "hot points" with high concentrations of uranium and thorium were found near the uranium reprocessing factory and the uranium mines.

  20. RECOVERY OF URANIUM BY CYCLOALKYLDITHIO-CARBAMATE COMPLEXING

    DOEpatents

    Neville, O.K.

    1959-06-30

    The separation of uranium-233 from an aqueous nitric acid solution of neutron irradiated thorium by selectively complexing the uranium is described. The separation is carried out by contacting the thorium solution with a non- aromatic organic dithiocarbamate selected from the group which consists of alkali and alkaline earth cycloalkyldithiocarbamates and recovering the resulting uranyl cycloalkyldithiocarbamate complex by organic solvent extraction such as with methyl ethyl ketone. The complexed uranium may be stripped from the separated organic phase by scrubbing with one normal nitric acid solution.

  1. Biosorption for the separation of radionuclides from drainage and process waters of the uranium mining industry

    SciTech Connect

    Glombitza, F.; Eckardt, L.; Hummel, A.

    1995-12-31

    Biosorption means the storage of substances at the cell envelope. Different microbial biomasses were tested for the separation of radionuclides from mining waters. Results of a pilot plant demonstrate the ability of these techniques for water cleaning processes. An effluent concentration of lower than 1 mg/l (in most cases 0.1 mg/1) could be realized in a pilot plant by using pure cells of a methylotrophic strain of bacteria as well as using of a fungal mycelia.

  2. Separation of thorium and uranium from silicate rock samples using two commercial extraction chromatographic resins.

    PubMed

    Yokoyama, T; Makishima, A; Nakamura, E

    1999-01-01

    A new chemical separation technique to isolate Th and U from silicate rocks was established by using two kinds of commercial extraction chromatographic resins. In the first column procedure, with U/TEVA·spec resin, almost all elements except Th and U were eluted by 4 M HNO(3). Th was then separated by using 5 M HCl, and U was finally isolated by successive addition of 0.1 M HNO(3). A significant amount of Zr still remained in the Th fraction, which was then further purified in the second column stage using TEVA·spec resin. In the second procedure, Zr was eluted first by using 2 M HNO(3), and then Th was collected by 0.1 M HNO(3). Both the Th and U fractions obtained by these procedures were sufficiently pure for thermal ionization mass spectrometric (TIMS) analysis. Recovery yields of Th and U exceeded 90%, and total blanks were <19 pg for Th and <10 pg for U. Our method has advantages over previous methods in terms of matrix effects, tailing problems, and degree of isolation. Since Th and U are effectively separated without suffering any matrix interference from coexisting cations and anions, this technique can be used not only for the analysis of igneous rock samples but also for the analysis of soils, marine sediments, carbonates, phosphates and seawater, groundwater, and surface water.

  3. Separation of thorium and uranium from silicate rock samples using two commercial extraction chromatographic resins.

    PubMed

    Yokoyama, T; Makishima, A; Nakamura, E

    1999-01-01

    A new chemical separation technique to isolate Th and U from silicate rocks was established by using two kinds of commercial extraction chromatographic resins. In the first column procedure, with U/TEVA·spec resin, almost all elements except Th and U were eluted by 4 M HNO(3). Th was then separated by using 5 M HCl, and U was finally isolated by successive addition of 0.1 M HNO(3). A significant amount of Zr still remained in the Th fraction, which was then further purified in the second column stage using TEVA·spec resin. In the second procedure, Zr was eluted first by using 2 M HNO(3), and then Th was collected by 0.1 M HNO(3). Both the Th and U fractions obtained by these procedures were sufficiently pure for thermal ionization mass spectrometric (TIMS) analysis. Recovery yields of Th and U exceeded 90%, and total blanks were <19 pg for Th and <10 pg for U. Our method has advantages over previous methods in terms of matrix effects, tailing problems, and degree of isolation. Since Th and U are effectively separated without suffering any matrix interference from coexisting cations and anions, this technique can be used not only for the analysis of igneous rock samples but also for the analysis of soils, marine sediments, carbonates, phosphates and seawater, groundwater, and surface water. PMID:21662935

  4. PROCESS FOR SEPARATING PLUTONIUM FROM IMPURITIES

    DOEpatents

    Wahl, A.C.

    1957-11-12

    A method is described for separating plutonium from aqueous solutions containing uranium. It has been found that if the plutonium is reduced to its 3+ valence state, and the uranium present is left in its higher valence state, then the differences in solubility between certain salts (e.g., oxalates) of the trivalent plutonium and the hexavalent uranium can be used to separate the metals. This selective reduction of plutonium is accomplished by adding iodide ion to the solution, since iodide possesses an oxidation potential sufficient to reduce plutonium but not sufficient to reduce uranium.

  5. Process for recovering uranium

    DOEpatents

    MacWood, G. E.; Wilder, C. D.; Altman, D.

    1959-03-24

    A process useful in recovering uranium from deposits on stainless steel liner surfaces of calutrons is presented. The deposit is removed from the stainless steel surface by washing with aqueous nitric acid. The solution obtained containing uranium, chromium, nickel, copper, and iron is treated with an excess of ammonium hydroxide to precipitnte the uranium, iron, and chromium and convert the nickel and copper to soluble ammonio complexions. The precipitated material is removed, dried and treated with carbon tetrachloride at an elevated temperature of about 500 to 600 deg C to form a vapor mixture of UCl/ sub 4/, UCl/sub 5/, FeCl/sub 3/, and CrCl/sub 4/. The UCl/sub 4/ is separated from this vapor mixture by selective fractional condensation at a temperature of about 500 to 400 deg C.

  6. PROCESS FOR RECOVERING URANIUM

    DOEpatents

    MacWood, G.E.; Wilder, C.D.; Altman, D.

    1959-03-24

    A process is described for recovering uranium from deposits on stainless steel liner surfaces of calutrons. The deposit is removed from the stainless steel surface by washing with aqueous nitric acid. The solution obtained containing uranium, chromium, nickels copper, and iron is treated with excess of ammonium hydroxide to precipitatc the uranium, irons and chromium and convert thc nickel and copper to soluble ammonia complexions. The precipitated material is removed, dried, and treated with carbon tetrachloride at an elevated temperature of about 500 to 600 deg C to form a vapor mixture of UCl/sub 4/, UCl/sub 5/, FeCl/ sub 3/, and CrCl/sub 4/. The UCl/sub 4/ is separated from this vapor mixture by selective fractional condensation at a temprrature of about 300 to400 deg C.

  7. DECONTAMINATION OF URANIUM

    DOEpatents

    Feder, H.M.; Chellew, N.R.

    1958-02-01

    This patent deals with the separation of rare earth and other fission products from neutron bombarded uranium. This is accomplished by melting the uranium in contact with either thorium oxide, maguesium oxide, alumnum oxide, beryllium oxide, or uranium dioxide. The melting is preferably carried out at from 1150 deg to 1400 deg C in an inert atmosphere, such as argon or helium. During this treatment a scale of uranium dioxide forms on the uranium whtch contains most of the fission products.

  8. Method for converting uranium oxides to uranium metal

    DOEpatents

    Duerksen, Walter K.

    1988-01-01

    A process is described for converting scrap and waste uranium oxide to uranium metal. The uranium oxide is sequentially reduced with a suitable reducing agent to a mixture of uranium metal and oxide products. The uranium metal is then converted to uranium hydride and the uranium hydride-containing mixture is then cooled to a temperature less than -100.degree. C. in an inert liquid which renders the uranium hydride ferromagnetic. The uranium hydride is then magnetically separated from the cooled mixture. The separated uranium hydride is readily converted to uranium metal by heating in an inert atmosphere. This process is environmentally acceptable and eliminates the use of hydrogen fluoride as well as the explosive conditions encountered in the previously employed bomb-reduction processes utilized for converting uranium oxides to uranium metal.

  9. Separating the Minor Actinides Through Advances in Selective Coordination Chemistry

    SciTech Connect

    Lumetta, Gregg J.; Braley, Jenifer C.; Sinkov, Sergey I.; Carter, Jennifer C.

    2012-08-22

    This report describes work conducted at the Pacific Northwest National Laboratory (PNNL) in Fiscal Year (FY) 2012 under the auspices of the Sigma Team for Minor Actinide Separation, funded by the U.S. Department of Energy Office of Nuclear Energy. Researchers at PNNL and Argonne National Laboratory (ANL) are investigating a simplified solvent extraction system for providing a single-step process to separate the minor actinide elements from acidic high-level liquid waste (HLW), including separating the minor actinides from the lanthanide fission products.

  10. Functional Sorbents for Selective Capture of Plutonium, Americium, Uranium, and Thorium in Blood

    SciTech Connect

    Yantasee, Wassana; Sangvanich, Thanapon; Creim, Jeffrey A.; Pattamakomsan, Kanda; Wiacek, Robert J.; Fryxell, Glen E.; Addleman, Raymond S.; Timchalk, Charles

    2010-09-01

    Nano-engineered solid sorbents for chelation of actinides (239Pu, 241Am, uranium, thorium) from human blood were developed and evaluated in vitro. These sorbents, known as the self-assembled monolayer on mesoporous supports (SAMMSTM), are hybrid materials created from attachment of organic moieties onto extremely high surface area mesoporous silica. The organic moieties known to be effective at capturing actinides including three isomers of hydroxypyridinone, diphosphonic acid, acetamide phosphonic acid, glycinyl urea, and diethylenetriamine pentaacetate analog were evaluated. SAMMS are being reported elsewhere as potential candidates for orally administered drug for radionuclide decorporation. Herein, actinide decorporation of SAMMS in blood were evaluated to assess their viability for sorbent hemoperfusion in renal insufficient patients, whose kidney clear radionuclides at very slow rate. Sorption affinity (Kd), sorption rate, selectivity, and stability of SAMMS were measured in batch contact experiments. An isomer of hydroxypyridinone (3,4-HOPO) on SAMMS demonstrated the highest affinity for decorporation of all four actinides and outperformed the DTPA analog on SAMMS and on commercial resins by a factor of 103-fold in term of affinity. A fifty percent reduction of actinides in blood was achieved within minutes with no evidence of protein fouling and material leaching in blood after 24 hr of contact time. Less than 0.4 wt.% of Si was dissolved from 3,4-HOPO-SAMMS across the pH of 0 to 8. The engineered form of SAMMS (bead format) was further evaluated in a 100-fold scaled-down hemoperfusion device and showed no blood clotting after 2 hr. A 0.2 g of SAMMS could reduce 50 wt.% of 100 ppb uranium in 50 mL of plasma in just 18 min and that of 500 dpm mL-1 in just 24 min. 3,4-HOPO-SAMMS has a long shelf-life in air and at room temperature for at least 8 years, indicating their feasibility for stockpiling in preparedness for emergency.

  11. Improvement of multi jet low pressure impactor for high collection efficiency of UF5 in the molecular laser isotope separation of uranium

    NASA Astrophysics Data System (ADS)

    Kuga, Yoshikazu; Jurcik, Benjamin; Satooka, Sakae; Takeuchi, Kazuo

    1995-07-01

    A numerical and experimental study for the collection of photo-produced UF 5 particles was performed for the low pressure impactors which have different design factors at typical flow conditions (upstream pressure of the impactor = 10-15 Torr, pressure ratio of downstream to upstream of the impactor, {P down}/{P up} = 0.2-0.5 ) in the molecular laser isotope separation of uranium at RIKEN (RIMLIS). Smaller {H}/{W} ratios (the distance between the impactor orifice exit and the impaction plate, H, divided by the orifice diameter of the impactor, W) and the smaller {P down}/{P up} were found to be preferable to obtain a higher collection efficiency from both numerical and experimental investigations. In addition it was experimentally demonstrated that the use of a 16 μm laser system for the selective reaction of 235UF 6 to form 235UF 5 was not relevant for the study of the collection of UF 5 particles. So, we used an ultraviolet laser system (fourth harmonic YAG laser (266 nm) and an excimer laser (KrF, 248 nm)) which was more convenient to cope with various operating conditions. The collection efficiency was found to increase with the initial concentration of UF 5 molecules produced. Applying the improved impactor stage, we obtained a collection efficiency which was approximately 10 times higher than that of our previous work. Higher collection efficiencies of photo-produced UF 5 particles enriched in 235U reduce the enrichment cost.

  12. Geological and geochemical aspects of uranium deposits: a selected, annotated bibliography. [474 references

    SciTech Connect

    Thomas, J.M.; Garland, P.A.; White, M.B.; Daniel, E.W.

    1980-09-01

    This bibliography, a compilation of 474 references, is the fourth in a series compiled from the National Uranium Resource Evaluation (NURE) Bibliographic Data Base. This data base was created for the Grand Junction Office of the Department of Energy's National Uranium Resource Evaluation Project by the Ecological Sciences Information Center, Oak Ridge National Laboratory. The references in the bibliography are arranged by subject category: (1) geochemistry, (2) exploration, (3) mineralogy, (4) genesis of deposits, (5) geology of deposits, (6) uranium industry, (7) geology of potential uranium-bearing areas, and (8) reserves and resources. The references are indexed by author, geographic location, quadrangle name, geoformational feature, and keyword.

  13. Determination of Uranium Metal Concentration in Irradiated Fuel Storage Basin Sludge Using Selective Dissolution

    SciTech Connect

    Delegard, Calvin H.; Sinkov, Sergey I.; Chenault, Jeffrey W.; Schmidt, Andrew J.; Welsh, Terri L.; Pool, Karl N.

    2014-03-01

    Uranium metal corroding in water-saturated sludges now held in the US Department of Energy Hanford Site K West irradiated fuel storage basin can create hazardous hydrogen atmospheres during handling, immobilization, or subsequent transport and storage. Knowledge of uranium metal concentration in sludge thus is essential to safe sludge management and process design, requiring an expeditious routine analytical method to detect uranium metal concentrations as low as 0.03 wt% in sludge even in the presence of 30 wt% or higher total uranium concentrations.

  14. A simple-rapid method to separate uranium, thorium, and protactinium for U-series age-dating of materials.

    PubMed

    Knight, Andrew W; Eitrheim, Eric S; Nelson, Andrew W; Nelson, Steven; Schultz, Michael K

    2014-08-01

    Uranium-series dating techniques require the isolation of radionuclides in high yields and in fractions free of impurities. Within this context, we describe a novel-rapid method for the separation and purification of U, Th, and Pa. The method takes advantage of differences in the chemistry of U, Th, and Pa, utilizing a commercially-available extraction chromatographic resin (TEVA) and standard reagents. The elution behavior of U, Th, and Pa were optimized using liquid scintillation counting techniques and fractional purity was evaluated by alpha-spectrometry. The overall method was further assessed by isotope dilution alpha-spectrometry for the preliminary age determination of an ancient carbonate sample obtained from the Lake Bonneville site in western Utah (United States). Preliminary evaluations of the method produced elemental purity of greater than 99.99% and radiochemical recoveries exceeding 90% for U and Th and 85% for Pa. Excellent purity and yields (76% for U, 96% for Th and 55% for Pa) were also obtained for the analysis of the carbonate samples and the preliminary Pa and Th ages of about 39,000 years before present are consistent with (14)C-derived age of the material.

  15. A simple-rapid method to separate uranium, thorium, and protactinium for U-series age-dating of materials.

    PubMed

    Knight, Andrew W; Eitrheim, Eric S; Nelson, Andrew W; Nelson, Steven; Schultz, Michael K

    2014-08-01

    Uranium-series dating techniques require the isolation of radionuclides in high yields and in fractions free of impurities. Within this context, we describe a novel-rapid method for the separation and purification of U, Th, and Pa. The method takes advantage of differences in the chemistry of U, Th, and Pa, utilizing a commercially-available extraction chromatographic resin (TEVA) and standard reagents. The elution behavior of U, Th, and Pa were optimized using liquid scintillation counting techniques and fractional purity was evaluated by alpha-spectrometry. The overall method was further assessed by isotope dilution alpha-spectrometry for the preliminary age determination of an ancient carbonate sample obtained from the Lake Bonneville site in western Utah (United States). Preliminary evaluations of the method produced elemental purity of greater than 99.99% and radiochemical recoveries exceeding 90% for U and Th and 85% for Pa. Excellent purity and yields (76% for U, 96% for Th and 55% for Pa) were also obtained for the analysis of the carbonate samples and the preliminary Pa and Th ages of about 39,000 years before present are consistent with (14)C-derived age of the material. PMID:24681438

  16. A selective electromembrane extraction of uranium (VI) prior to its fluorometric determination in water.

    PubMed

    Davarani, Saied Saeed Hosseiny; Moazami, Hamid Reza; Keshtkar, Ali Reza; Banitaba, Mohammad Hossein; Nojavan, Saeed

    2013-06-14

    A novel method for the selective electromembrane extraction (EME) of U(6+) prior to fluorometric determination has been proposed. The effect of extraction conditions including supported liquid membrane (SLM) composition, extraction time and extraction voltage were investigated. An SLM composition of 1% di-2-ethyl hexyl phosphonic acid in nitrophenyl octyl ether (NPOE) showed good selectivity, recovery and enrichment factor. The best performance was achieved at an extraction potential of 80 volts and an extraction time of 14 minutes Under the optimized conditions, a linear range from 1 to 1000 ng mL(-1) and LOD of 0.1 ng mL(-1) were obtained for the determination of U(6+). The EME method showed good performance in sample cleanup and the reduction of the interfering effects of Mn(2+), Zn(2+), Cd(2+), Ni(2+), Fe(3+), Co(2+), Cu(2+), Cl(-) and PO4(3-) ions during fluorometric determination of uranium in real water samples. The recoveries above 54% and enrichment factors above 64.7 were obtained by the proposed method for real sample analysis. PMID:23726102

  17. A selective electromembrane extraction of uranium (VI) prior to its fluorometric determination in water.

    PubMed

    Davarani, Saied Saeed Hosseiny; Moazami, Hamid Reza; Keshtkar, Ali Reza; Banitaba, Mohammad Hossein; Nojavan, Saeed

    2013-06-14

    A novel method for the selective electromembrane extraction (EME) of U(6+) prior to fluorometric determination has been proposed. The effect of extraction conditions including supported liquid membrane (SLM) composition, extraction time and extraction voltage were investigated. An SLM composition of 1% di-2-ethyl hexyl phosphonic acid in nitrophenyl octyl ether (NPOE) showed good selectivity, recovery and enrichment factor. The best performance was achieved at an extraction potential of 80 volts and an extraction time of 14 minutes Under the optimized conditions, a linear range from 1 to 1000 ng mL(-1) and LOD of 0.1 ng mL(-1) were obtained for the determination of U(6+). The EME method showed good performance in sample cleanup and the reduction of the interfering effects of Mn(2+), Zn(2+), Cd(2+), Ni(2+), Fe(3+), Co(2+), Cu(2+), Cl(-) and PO4(3-) ions during fluorometric determination of uranium in real water samples. The recoveries above 54% and enrichment factors above 64.7 were obtained by the proposed method for real sample analysis.

  18. Uranium hexafluoride handling. Proceedings

    SciTech Connect

    Not Available

    1991-12-31

    The United States Department of Energy, Oak Ridge Field Office, and Martin Marietta Energy Systems, Inc., are co-sponsoring this Second International Conference on Uranium Hexafluoride Handling. The conference is offered as a forum for the exchange of information and concepts regarding the technical and regulatory issues and the safety aspects which relate to the handling of uranium hexafluoride. Through the papers presented here, we attempt not only to share technological advances and lessons learned, but also to demonstrate that we are concerned about the health and safety of our workers and the public, and are good stewards of the environment in which we all work and live. These proceedings are a compilation of the work of many experts in that phase of world-wide industry which comprises the nuclear fuel cycle. Their experience spans the entire range over which uranium hexafluoride is involved in the fuel cycle, from the production of UF{sub 6} from the naturally-occurring oxide to its re-conversion to oxide for reactor fuels. The papers furnish insights into the chemical, physical, and nuclear properties of uranium hexafluoride as they influence its transport, storage, and the design and operation of plant-scale facilities for production, processing, and conversion to oxide. The papers demonstrate, in an industry often cited for its excellent safety record, continuing efforts to further improve safety in all areas of handling uranium hexafluoride. Selected papers were processed separately for inclusion in the Energy Science and Technology Database.

  19. Dynamic graphene filters for selective gas-water-oil separation

    NASA Astrophysics Data System (ADS)

    Bong, Jihye; Lim, Taekyung; Seo, Keumyoung; Kwon, Cho-Ah; Park, Ju Hyun; Kwak, Sang Kyu; Ju, Sanghyun

    2015-09-01

    Selective filtration of gas, water, and liquid or gaseous oil is essential to prevent possible environmental pollution and machine/facility malfunction in oil-based industries. Novel materials and structures able to selectively and efficiently filter liquid and vapor in various types of solutions are therefore in continuous demand. Here, we investigate selective gas-water-oil filtration using three-dimensional graphene structures. The proposed approach is based on the adjustable wettability of three-dimensional graphene foams. Three such structures are developed in this study; the first allows gas, oil, and water to pass, the second blocks water only, and the third is exclusively permeable to gas. In addition, the ability of three-dimensional graphene structures with a self-assembled monolayer to selectively filter oil is demonstrated. This methodology has numerous potential practical applications as gas, water, and/or oil filtration is an essential component of many industries.

  20. Dynamic graphene filters for selective gas-water-oil separation.

    PubMed

    Bong, Jihye; Lim, Taekyung; Seo, Keumyoung; Kwon, Cho-Ah; Park, Ju Hyun; Kwak, Sang Kyu; Ju, Sanghyun

    2015-09-23

    Selective filtration of gas, water, and liquid or gaseous oil is essential to prevent possible environmental pollution and machine/facility malfunction in oil-based industries. Novel materials and structures able to selectively and efficiently filter liquid and vapor in various types of solutions are therefore in continuous demand. Here, we investigate selective gas-water-oil filtration using three-dimensional graphene structures. The proposed approach is based on the adjustable wettability of three-dimensional graphene foams. Three such structures are developed in this study; the first allows gas, oil, and water to pass, the second blocks water only, and the third is exclusively permeable to gas. In addition, the ability of three-dimensional graphene structures with a self-assembled monolayer to selectively filter oil is demonstrated. This methodology has numerous potential practical applications as gas, water, and/or oil filtration is an essential component of many industries.

  1. Dynamic graphene filters for selective gas-water-oil separation

    PubMed Central

    Bong, Jihye; Lim, Taekyung; Seo, Keumyoung; Kwon, Cho-Ah; Park, Ju Hyun; Kwak, Sang Kyu; Ju, Sanghyun

    2015-01-01

    Selective filtration of gas, water, and liquid or gaseous oil is essential to prevent possible environmental pollution and machine/facility malfunction in oil-based industries. Novel materials and structures able to selectively and efficiently filter liquid and vapor in various types of solutions are therefore in continuous demand. Here, we investigate selective gas-water-oil filtration using three-dimensional graphene structures. The proposed approach is based on the adjustable wettability of three-dimensional graphene foams. Three such structures are developed in this study; the first allows gas, oil, and water to pass, the second blocks water only, and the third is exclusively permeable to gas. In addition, the ability of three-dimensional graphene structures with a self-assembled monolayer to selectively filter oil is demonstrated. This methodology has numerous potential practical applications as gas, water, and/or oil filtration is an essential component of many industries. PMID:26394930

  2. Selectivity trend of gas separation through nanoporous graphene

    DOE PAGES

    Liu, Hongjun; Chen, Zhongfang; Dai, Sheng; Jiang, De-en

    2014-01-29

    We demonstrate that porous graphene can efficiently separate gases according to their molecular sizes using molecular dynamic (MD) simulations,. The flux sequence from the classical MD simulation is H2>CO2>>N2>Ar>CH4, which generally follows the trend in the kinetic diameters. Moreover, this trend is also confirmed from the fluxes based on the computed free energy barriers for gas permeation using the umbrella sampling method and kinetic theory of gases. Both brute-force MD simulations and free-energy calcualtions lead to the flux trend consistent with experiments. Case studies of two compositions of CO2/N2 mixtures further demonstrate the separation capability of nanoporous graphene.

  3. Selectivity trend of gas separation through nanoporous graphene

    SciTech Connect

    Liu, Hongjun; Chen, Zhongfang; Dai, Sheng; Jiang, De-en

    2014-01-29

    We demonstrate that porous graphene can efficiently separate gases according to their molecular sizes using molecular dynamic (MD) simulations,. The flux sequence from the classical MD simulation is H2>CO2>>N2>Ar>CH4, which generally follows the trend in the kinetic diameters. Moreover, this trend is also confirmed from the fluxes based on the computed free energy barriers for gas permeation using the umbrella sampling method and kinetic theory of gases. Both brute-force MD simulations and free-energy calcualtions lead to the flux trend consistent with experiments. Case studies of two compositions of CO2/N2 mixtures further demonstrate the separation capability of nanoporous graphene.

  4. STRIPPING OF URANIUM FROM ORGANIC EXTRACTANTS

    DOEpatents

    Crouse, D.J. Jr.

    1962-09-01

    A liquid-liquid extraction method is given for recovering uranium values from uranium-containing solutions. Uranium is removed from a uranium-containing organic solution by contacting said organic solution with an aqueous ammonium carbonate solution substantially saturated in uranium values. A uranium- containing precipitate is thereby formed which is separated from the organic and aqueous phases. Uranium values are recovered from this separated precipitate. (AE C)

  5. Isotope separation by selective charge conversion and field deflection

    DOEpatents

    Hickman, Robert G.

    1978-01-01

    A deuterium-tritium separation system wherein a source beam comprised of positively ionized deuterium (D.sup.+) and tritium (T.sup.+) is converted at different charge-exchange cell sections of the system to negatively ionized deuterium (D.sup.-) and tritium (T.sup.-). First, energy is added to the beam to accelerate the D.sup.+ ions to the velocity that is optimum for conversion of the D.sup.+ ions to D.sup.- ions in a charge-exchange cell. The T.sup.+ ions are accelerated at the same time, but not to the optimum velocity since they are heavier than the D.sup.+ ions. The T.sup.+ ions are, therefore, not converted to T.sup.- ions when the D.sup.+ ions are converted to D.sup.- ions. This enables effective separation of the beam by deflection of the isotopes with an electrostatic field, the D.sup.- ions being deflected in one direction and the T.sup.+ ions being deflected in the opposite direction. Next, more energy is added to the deflected beam of T.sup.+ ions to bring the T.sup.+ ions to the optimum velocity for their conversion to T.sup.- ions. In a particular use of the invention, the beams of D.sup.- and T.sup.- ions are separately further accelerated and then converted to energetic neutral particles for injection as fuel into a thermonuclear reactor. The reactor exhaust of D.sup.+ and T.sup.+ and the D.sup.+ and T.sup.+ that was not converted in the respective sections is combined with the source beam and recycled through the system to increase the efficiency of the system.

  6. Metal-Organic Frameworks for Highly Selective Separations

    SciTech Connect

    Omar M. Yaghi

    2009-09-28

    This grant was focused on the study of metal-organic frameworks with these specific objectives. (1) To examine the use of MOFs with well-defined open metal sites for binding of gases and small organics. (2) To develop a strategy for producing MOFs that combine large pore size with high surface area for their use in gas adsorption and separation of polycyclic organic compounds. (3) To functionalize MOFs for the storage of inert gases such as methane. A brief outline of our progress towards these objectives is presented here as it forms part of the basis for the ideas to be developed under the present proposal.

  7. Diameter-selective separation of double-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Kim, Jin Hee; Kataoka, Masakazu; Kim, Yoong Ahm; Shimamoto, Daisuke; Muramatsu, Hiroyuki; Hayashi, Takuya; Endo, Morinobu; Terrones, Mauricio; Dresselhaus, Mildred S.

    2008-12-01

    Here, we report a simple and effective way of separating double-walled carbon nanotubes as a function of their diameter using individually dispersed nanotube solutions with the aid of long and random single-stranded DNA. The subtle pH change in nanotube solutions gives rise to the preferential coagulation of large-diameter tubes and allows the easy preparation of small-diameter tubes. The stronger van der Waals forces between large-diameter tubes, combined with the decreased solubility of DNA in water at low pH, lead to the preferential agglomeration of large-diameter tubes.

  8. Natural Gamma Emitters after a Selective Chemical Separation of a TENORM residue: Preliminary Results

    SciTech Connect

    Alves de Freitas, Antonio; Abrao, Alcidio; Godoy dos Santos, Adir Janete; Pecequilo, Brigitte Roxana Soreanu

    2008-08-07

    An analytical procedure was established in order to obtain selective fractions containing radium isotopes ({sup 228}Ra), thorium ({sup 232}Th), and rare earths from RETOTER (REsiduo de TOrio e TErras Raras), a solid residue rich in rare earth elements, thorium isotopes and small amount of natural uranium generated from the operation of a thorium pilot plant for purification and production of pure thorium nitrate at IPEN -CNEN/SP. The paper presents preliminary results of {sup 228}Ra, {sup 226}Ra, {sup 238}U, {sup 210}Pb, and {sup 40}K concentrations in the selective fractions and total residue determined by high-resolution gamma spectroscopy, considering radioactive equilibrium of the samples.

  9. Functional sorbents for selective capture of plutonium, americium, uranium, and thorium in blood.

    PubMed

    Yantasee, Wassana; Sangvanich, Thanapon; Creim, Jeffery A; Pattamakomsan, Kanda; Wiacek, Robert J; Fryxell, Glen E; Addleman, R Shane; Timchalk, Charles

    2010-09-01

    Self-assembled monolayer on mesoporous supports (SAMMS) are hybrid materials created from attachment of organic moieties onto very high surface area mesoporous silica. SAMMS with surface chemistries including three isomers of hydroxypyridinone, diphosphonic acid, acetamide phosphonic acid, glycinyl urea, and diethylenetriamine pentaacetate (DTPA) analog were evaluated for chelation of actinides ((239)Pu, (241)Am, uranium, thorium) from blood. Direct blood decorporation using sorbents does not have the toxicity or renal challenges associated with traditional chelation therapy and may have potential applications for critical exposure cases, reduction of nonspecific dose during actinide radiotherapy, and for sorbent hemoperfusion in renal insufficient patients, whose kidneys clear radionuclides at a very slow rate. Sorption affinity (K(d)), sorption rate, selectivity, and stability of SAMMS were measured in batch contact experiments. An isomer of hydroxypyridinone (3,4-HOPO) on SAMMS demonstrated the highest affinity for all four actinides from blood and plasma and greatly outperformed the DTPA analog on SAMMS and commercial resins. In batch contact, a fifty percent reduction of actinides in blood was achieved within minutes, and there was no evidence of protein fouling or material leaching in blood after 24 h. The engineered form of SAMMS (bead format) was further evaluated in a 100-fold scaled-down hemoperfusion device and showed no blood clotting after 2 h. A 0.2 g quantity of SAMMS could reduce 50 wt.% of 100 ppb uranium in 50 mL of plasma in 18 min and that of 500 dpm mL(-1) in 24 min. 3,4-HOPO-SAMMS has a long shelf-life in air and at room temperature for at least 8 y, indicating its feasibility for stockpiling in preparedness for an emergency. The excellent efficacy and stability of SAMMS materials in complex biological matrices suggest that SAMMS can also be used as orally administered drugs and for wound decontamination. By changing the organic groups of

  10. Impact of Electron Donor selection on In-situ Biosequestration of Uranium

    NASA Astrophysics Data System (ADS)

    Tabatabaei, S.; Zhong, H.; Abel, E. J.; Field, J.; Brusseau, M. L. L.

    2015-12-01

    In-situ biosequestration, wherein electron-donating substrates are injected to promote microbial-associated sequestration of contaminants, is one promising enhanced-attenuation technique for remediation of groundwater containing arsenic, uranium, selenium, and similar constituents. A pilot-scale test of in-situ biosequestration for uranium in groundwater is in process at a former uranium mining site in Monument Valley, Arizona. Complementary bench experiments were conducted to examine the impact of different electron donors on the effectiveness of biosequestration. Aqueous and sediment samples were collected before and after the injection for monitoring changes in sediment properties, mineral geochemical composition, microbial community composition, and microbial activity.

  11. Separation of rare gases and chiral molecules by selective binding in porous organic cages.

    PubMed

    Chen, Linjiang; Reiss, Paul S; Chong, Samantha Y; Holden, Daniel; Jelfs, Kim E; Hasell, Tom; Little, Marc A; Kewley, Adam; Briggs, Michael E; Stephenson, Andrew; Thomas, K Mark; Armstrong, Jayne A; Bell, Jon; Busto, Jose; Noel, Raymond; Liu, Jian; Strachan, Denis M; Thallapally, Praveen K; Cooper, Andrew I

    2014-10-01

    The separation of molecules with similar size and shape is an important technological challenge. For example, rare gases can pose either an economic opportunity or an environmental hazard and there is a need to separate these spherical molecules selectively at low concentrations in air. Likewise, chiral molecules are important building blocks for pharmaceuticals, but chiral enantiomers, by definition, have identical size and shape, and their separation can be challenging. Here we show that a porous organic cage molecule has unprecedented performance in the solid state for the separation of rare gases, such as krypton and xenon. The selectivity arises from a precise size match between the rare gas and the organic cage cavity, as predicted by molecular simulations. Breakthrough experiments demonstrate real practical potential for the separation of krypton, xenon and radon from air at concentrations of only a few parts per million. We also demonstrate selective binding of chiral organic molecules such as 1-phenylethanol, suggesting applications in enantioselective separation. PMID:25038731

  12. Separation of rare gases and chiral molecules by selective binding in porous organic cages

    NASA Astrophysics Data System (ADS)

    Chen, Linjiang; Reiss, Paul S.; Chong, Samantha Y.; Holden, Daniel; Jelfs, Kim E.; Hasell, Tom; Little, Marc A.; Kewley, Adam; Briggs, Michael E.; Stephenson, Andrew; Thomas, K. Mark; Armstrong, Jayne A.; Bell, Jon; Busto, Jose; Noel, Raymond; Liu, Jian; Strachan, Denis M.; Thallapally, Praveen K.; Cooper, Andrew I.

    2014-10-01

    The separation of molecules with similar size and shape is an important technological challenge. For example, rare gases can pose either an economic opportunity or an environmental hazard and there is a need to separate these spherical molecules selectively at low concentrations in air. Likewise, chiral molecules are important building blocks for pharmaceuticals, but chiral enantiomers, by definition, have identical size and shape, and their separation can be challenging. Here we show that a porous organic cage molecule has unprecedented performance in the solid state for the separation of rare gases, such as krypton and xenon. The selectivity arises from a precise size match between the rare gas and the organic cage cavity, as predicted by molecular simulations. Breakthrough experiments demonstrate real practical potential for the separation of krypton, xenon and radon from air at concentrations of only a few parts per million. We also demonstrate selective binding of chiral organic molecules such as 1-phenylethanol, suggesting applications in enantioselective separation.

  13. Costs of antibiotic resistance - separating trait effects and selective effects.

    PubMed

    Hall, Alex R; Angst, Daniel C; Schiessl, Konstanze T; Ackermann, Martin

    2015-03-01

    Antibiotic resistance can impair bacterial growth or competitive ability in the absence of antibiotics, frequently referred to as a 'cost' of resistance. Theory and experiments emphasize the importance of such effects for the distribution of resistance in pathogenic populations. However, recent work shows that costs of resistance are highly variable depending on environmental factors such as nutrient supply and population structure, as well as genetic factors including the mechanism of resistance and genetic background. Here, we suggest that such variation can be better understood by distinguishing between the effects of resistance mechanisms on individual traits such as growth rate or yield ('trait effects') and effects on genotype frequencies over time ('selective effects'). We first give a brief overview of the biological basis of costs of resistance and how trait effects may translate to selective effects in different environmental conditions. We then review empirical evidence of genetic and environmental variation of both types of effects and how such variation may be understood by combining molecular microbiological information with concepts from evolution and ecology. Ultimately, disentangling different types of costs may permit the identification of interventions that maximize the cost of resistance and therefore accelerate its decline.

  14. PRODUCTION OF URANIUM

    DOEpatents

    Spedding, F.H.; Wilhelm, H.A.; Keller, W.H.

    1958-04-15

    The production of uranium metal by the reduction of uranium tetrafluoride is described. Massive uranium metal of high purily is produced by reacting uranium tetrafluoride with 2 to 20% stoichiometric excess of magnesium at a temperature sufficient to promote the reaction and then mantaining the reaction mass in a sealed vessel at temperature in the range of 1150 to 2000 d C, under a superatomospheric pressure of magnesium for a period of time sufficient 10 allow separation of liquid uranium and liquid magnesium fluoride into separate layers.

  15. Selective Metal Deposition on a Phase-Separated Polymer Blend Surface

    NASA Astrophysics Data System (ADS)

    Tsujioka, Tsuyoshi; Yamaguchi, Koji

    2013-07-01

    We report selective metal deposition on a phase-separated polymer blend surface. A polymer blend film consisting of polystyrene (PS) and a polystyrene-block-polybutadiene copolymer (PS-BR) was annealed, and a micro-phase-separated film was obtained. Pb was evaporated onto the phase-separated surface without an evaporation mask and was selectively deposited on the PS phase but not on the PS-BR phase. We achieved fine metal patterns corresponding to the microphase separation. This result suggests a novel method of preparing fine metal patterns for electronics and photonics.

  16. Bioremediation of uranium contamination with enzymatic uranium reduction

    USGS Publications Warehouse

    Lovley, D.R.; Phillips, E.J.P.

    1992-01-01

    Enzymatic uranium reduction by Desulfovibrio desulfuricans readily removed uranium from solution in a batch system or when D. desulfuricans was separated from the bulk of the uranium-containing water by a semipermeable membrane. Uranium reduction continued at concentrations as high as 24 mM. Of a variety of potentially inhibiting anions and metals evaluated, only high concentrations of copper inhibited uranium reduction. Freeze-dried cells, stored aerobically, reduced uranium as fast as fresh cells. D. desulfuricans reduced uranium in pH 4 and pH 7.4 mine drainage waters and in uraniumcontaining groundwaters from a contaminated Department of Energy site. Enzymatic uranium reduction has several potential advantages over other bioprocessing techniques for uranium removal, the most important of which are as follows: the ability to precipitate uranium that is in the form of a uranyl carbonate complex; high capacity for uranium removal per cell; the formation of a compact, relatively pure, uranium precipitate.

  17. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Paducah Gaseous Diffusion Plant site

    SciTech Connect

    Marmer, G.J.; Dunn, C.P.; Moeller, K.L.; Pfingston, J.M.; Policastro, A.J.; Yuen, C.R.; Cleland, J.H.

    1991-09-01

    Uranium enrichment in the United States has utilized a diffusion process to preferentially enrich the U-235 isotope in the uranium product. The U-AVLIS process is based on electrostatic extraction of photoionized U-235 atoms from an atomic vapor stream created by electron-beam vaporization of uranium metal alloy. The U-235 atoms are ionized when precisely tuned laser light -- of appropriate power, spectral, and temporal characteristics -- illuminates the uranium vapor and selectively photoionizes the U-235 isotope. A programmatic document for use in screening DOE site to locate a U-AVLIS production plant was developed and implemented in two parts. The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. These sites were subjected to a more rigorous and detailed comparative analysis for the purpose of developing a short list of reasonable alternative sites for later environmental examination. This environmental site description (ESD) provides a detailed description of the PGDP site and vicinity suitable for use in an environmental impact statement (EIS). The report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during a site visit. 65 refs., 15 tabs.

  18. Laboratory Enrichment of Radioactive Assemblages and Estimation of Thorium and Uranium Radioactivity in Fractions Separated from Placer Sands in Southeast Bangladesh

    SciTech Connect

    Sasaki, Takayuki; Rajib, Mohammad; Akiyoshi, Masafumi; Kobayashi, Taishi; Takagi, Ikuji; Fujii, Toshiyuki; Zaman, Md. Mashrur

    2015-06-15

    The present study reports the likely first attempt of separating radioactive minerals for estimation of activity concentration in the beach placer sands of Bangladesh. Several sand samples from heavy mineral deposits located at the south-eastern coastal belt of Bangladesh were processed to physically upgrade their radioactivity concentrations using plant and laboratory equipment. Following some modified flow procedure, individual fractions were separated and investigated using gamma-ray spectrometry and powder-XRD analysis. The radioactivity measurements indicated contributions of the thorium and uranium radioactive series and of {sup 40}K. The maximum values of {sup 232}Th and {sup 238}U, estimated from the radioactivity of {sup 208}Tl and {sup 234}Th in secular equilibrium, were found to be 152,000 and 63,300 Bq/kg, respectively. The fraction of the moderately conductive part in electric separation contained thorium predominantly, while that of the non-conductive part was found to be uranium rich. The present arrangement of the pilot plant cascade and the fine tuning of setting parameters were found to be effective and economic separation process of the radioactive minerals from placer sands in Bangladesh. Probable radiological impacts and extraction potentiality of such radioactive materials are also discussed.

  19. Sulfate Separation by Selective Crystallization of a Urea-Functionalized Metal-Organic Framework

    SciTech Connect

    Custelcean, Radu; Sellin, Vincent; Moyer, Bruce A

    2007-01-01

    Encapsulation of SO{sub 4}{sup 2-} into a Ni coordination framework functionalized with urea anion-binding groups allows selective separation of this strongly hydrophilic anion from a highly competitive aqueous environment.

  20. Selective aqueous extraction of organics coupled with trapping by membrane separation

    DOEpatents

    van Eikeren, Paul; Brose, Daniel J.; Ray, Roderick J.

    1991-01-01

    An improvement to processes for the selective extractation of organic solutes from organic solvents by water-based extractants is disclosed, the improvement comprising coupling various membrane separation processes with the organic extraction process, the membrane separation process being utilized to continuously recycle the water-based extractant and at the same time selectively remove or concentrate organic solute from the water-based extractant.

  1. Factors influencing the electrospray intrasource separation and selective ionization of glycerophospholipids.

    PubMed

    Han, Xianlin; Yang, Kui; Yang, Jingyue; Fikes, Kora N; Cheng, Hua; Gross, Richard W

    2006-02-01

    The external electric field induces a separation of cations from negative electrolyte ions in the infusate while differential ionization of molecular species that possess differential electrical propensities can be induced in either the positive- or negative-ion mode during the electrospray ionization process. These physical and electrical processes that occur in the electrospray ion source have been used to selectively ionize lipid classes possessing different electrical propensities that are now known as "intrasource separation and selective ionization". However, the chemical principles underlying charge-dependent alterations in ionization efficiencies responsible for the selective ionization of lipid classes are not known with certainty. Herein, we examined the multiple factors that contribute to intrasource separation and selective ionization of lipid classes under optimal instrumental conditions. We demonstrated that many different lipid classes could be selectively ionized in the ion source and that intrasource resolution of distinct molecular constituents was independent of lipid concentration, flow rate, and residual ions under most experimental conditions. Moreover, the presence of alkaline conditions facilitates the selective ionization of many lipid classes through a mechanism independent of the design of the ESI ion source. Collectively, this study provides an empirical foundation for understanding the chemical mechanisms underlying intrasource separation and selective ionization of lipid classes that can potentially be used for global analysis of cellular lipidomes without the need for chromatographic separation.

  2. Loading Capacities for Uranium, Plutonium and Neptunium in High Caustic Nuclear Waste Storage Tanks Containing Selected Sorbents

    SciTech Connect

    OJI, LAWRENCE

    2004-11-16

    In this study the loading capacities of selected actinides onto some of the most common sorbent materials which are present in caustic nuclear waste storage tanks have been determined. Some of these transition metal oxides and activated carbons easily absorb or precipitate plutonium, neptunium and even uranium, which if care is not taken may lead to unwanted accumulation of some of these fissile materials in nuclear waste tanks during waste processing. Based on a caustic synthetic salt solution simulant bearing plutonium, uranium and neptunium and ''real'' nuclear waste supernate solution, the loading capacities of these actinides onto iron oxide (hematite), activated carbon and anhydrous sodium phosphate have been determined. The loading capacities for plutonium onto granular activated carbon and iron oxide (hematite) in a caustic synthetic salt solution were, respectively, 3.4 0.22 plus or minus and 5.5 plus or minus 0.38 microgram per gram of sorbent. The loading capacity for plutonium onto a typical nuclear waste storage tank sludge solids was 2.01 microgram per gram of sludge solids. The loading capacities for neptunium onto granular activated carbon and iron oxide (hematite) in a caustic synthetic salt solution were, respectively, 7.9 plus or minus 0.52 and greater than 10 microgram per gram of sorbent. The loading capacity for neptunium onto a typical nuclear waste storage tank sludge solids was 4.48 microgram per gram of sludge solids. A typical nuclear waste storage tank solid material did not show any significant affinity for uranium. Sodium phosphate showed significant affinity for both neptunium and uranium, with loading capacities of 6.8 and 184.6 plus or minus 18.5 microgram per gram of sorbent, respectively.

  3. In-line assay monitor for uranium hexafluoride

    DOEpatents

    Wallace, S.A.

    1980-03-21

    An in-line assay monitor for determining the content of uranium-235 in a uranium hexafluoride gas isotopic separation system is provided which removes the necessity of complete access to the operating parameters of the system for determining the uranium-235 content. The method and monitor for carrying out the method involve cooling of a radiation pervious chamber connected in fluid communication with the selected point in the system to withdraw a specimen and solidify the specimen in the chamber. The specimen is irradiated by means of an ionizing radiation source of energy different from that of the 185 keV gamma emissions from uranium-235. The uranium-235 content of the specimen is determined from comparison of the accumulated 185 keV energy counts and reference energy counts. The latter is used to measure the total uranium isotopic content of the specimen.

  4. Appraisal of selected epidemiologic issues from studies of lung cancer among uranium and hard rock miners

    SciTech Connect

    Petersen, G R; Sever, L E

    1982-04-01

    An extensive body of published information about lung cancer among uranium miners was reviewed and diverse information, useful in identifying important issues but not in resolving them was found. Measuring exposure and response; thresholds of exposure; latency or the period from first mining experience to death; effort to predict excess risk of death, using a model; effects of smoking and radon daughter exposure on the histology of lung tumors; and the interplay of factors on the overall risk of death were all examined. The general concept of thresholds; that is, an exposure level below which risk does not increase was considered. The conclusion is that it should be possible to detect and estimate an epidemiologic threshold when the cohorts have been followed to the death of all members. Issues concerning latency in the studies of uranium miners published to date were examined. It is believed that the induction-latent period for lung cancer among uranium miners may be: as little as 10 to more than 40 years; dependent on age at which exposure begins; exposure rate; and ethnicity or smoking habits. Although suggested as factual, their existence is uncertain. An effect due to the exposure rate may exist although it has not been factual, their existence is uncertain. An effect due to the exposure rate may exist although it has not been confirmed. The median induction-latent period appears to be in excess of the 15 years frequently cited for US uranium miner. A distinct pattern of shorter induction-latent periods with increasing age at first mining exposure is reported. The evidence for and against an unusual histologic pattern of lung cancers among uranium miners was examined. The ratio of epidermoid to small cell types was close to 1:2; the ratio in the general population is nearer 2:1. The histologic pattern warrants closer attention of pathologists and epidemiologists. (ERB) (ERB)

  5. Uranium geochemistry of selected rock units from the Marysvale Volcanic Field, Piute County, Utah

    SciTech Connect

    Hoffer, R.L.

    1982-01-01

    The Marysvale Volcanic Field is an area rich in uranium. This study was undertaken to determine if the uranium deposits might be of volcanogenic origin. This geochemical study consisted of determining the major, minor and trace element concentrations of the major volcanic units, and the relationships of the rock chemistry to uranium mineralization. The units in the Marysvale Volcanic Field, consist of ash-flow tuffs, intermediate lava flows, and associated intrusives of the Bullion Canyon volcanics and ash-flow tuffs, volcaniclastic deposits, domes and stocks of the Mount Belknap volcanics. When compared to overlaying welded tuff or rhyolitic units, the vitrophyric samples from the Mount Belknap volcanic units, are all enriched in F, Cs, and U, and that 50% of the vitrophyres are enriched in Cr, Cu, Mo, Ni, Zr, Pb, Sr, V, and Zn. Overlying untis have been devitrified and have released U as well as other trace elements into the volcanogenic system. This study has reevaluated the Marysvale Central Mining District and has proposed another theory as to the origin of the uranium deposits in that area. This hypothesis places a previously unidentified caldera around the area, and this author has named it the Marysvale caldera. Evidence for this caldera includes: arcurate faults which surround the region; alteration patterns which appear to form a circular pattern along the boundary of the proposed caldera; the presence of small monzonite intrusive bodies appear to ring the caldera; the presence of ash-flow tuffs which thicken appreciably along the northeast boundary of the caldera; and the central intrusive which may represent a resurgent phase of the proposed caldera. This seems to be a viable alternative to the magmatic hydrothermal origin for the uranium deposits presently proposed for the Central Mining District.

  6. Radiation synthesis of a new amidoximated UHMWPE fibrous adsorbent with high adsorption selectivity for uranium over vanadium in simulated seawater

    NASA Astrophysics Data System (ADS)

    Gao, Qianhong; Hu, Jiangtao; Li, Rong; Xing, Zhe; Xu, Lu; Wang, Mouhua; Guo, Xiaojing; Wu, Guozhong

    2016-05-01

    A new kind of highly efficient adsorbent material has been fabricated in this study for the purpose of extracting uranium from seawater. Ultra-high molecular weight polyethylene (UHMWPE) fiber was used as a trunk material for the adsorbent, which was prepared by a series of modification reactions, as follows: (1) grafting of glycidyl methacrylate (GMA) and methyl acrylate (MA) onto UHMWPE fibers via 60Co γ-ray pre-irradiation; (2) aminolyzation of UHMWPE fiber by the ring-opening reaction between of epoxy groups PGMA and ethylene diamine (EDA); (3) Michael addition of amino groups with acrylonitrile (AN) to yield nitrile groups; (4) amidoximation of the attached nitrile moieties by hydroxylamine in dimethyl sulfoxide-water mixture. Modified UHMWPE fibers were characterized by means of attenuated total reflectance-Fourier transformed infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) to confirm the attachment of amidoxime (AO) groups onto the UHMWPE fibers. The results of X-ray diffraction (XRD) and single fiber tensile strength verified that the modified UHMWPE fiber retained excellent mechanical properties at a low absorbed radiation dose. The adsorption performance of the UHMWPE fibrous adsorbent was evaluated by subjecting it to an adsorption test in simulated seawater using a continuous-flow mode. The amount of uranium adsorbed by this AO-based UHMWPE fibrous adsorbent was 1.97 mg-U/g after 42 days. This new adsorbent also showed high selectivity for the uranyl ion, and its selectivity for metal ions was found to decrease in the following order: U>Cu>Fe>Ca>Mg>Ni>Zn>Pb>V>Co. The adsorption selectivity for uranium is significantly higher than that for vanadium. In addition, preparation of this modified adsorbent consumes much smaller amounts of the toxic acrylonitrile monomer than the conventional preparation methods of AO-based polyethylene fibers.

  7. Removal of uranium from uranium-contaminated soils -- Phase 1: Bench-scale testing. Uranium in Soils Integrated Demonstration

    SciTech Connect

    Francis, C. W.

    1993-09-01

    To address the management of uranium-contaminated soils at Fernald and other DOE sites, the DOE Office of Technology Development formed the Uranium in Soils Integrated Demonstration (USID) program. The USID has five major tasks. These include the development and demonstration of technologies that are able to (1) characterize the uranium in soil, (2) decontaminate or remove uranium from the soil, (3) treat the soil and dispose of any waste, (4) establish performance assessments, and (5) meet necessary state and federal regulations. This report deals with soil decontamination or removal of uranium from contaminated soils. The report was compiled by the USID task group that addresses soil decontamination; includes data from projects under the management of four DOE facilities [Argonne National Laboratory (ANL), Los Alamos National Laboratory (LANL), Oak Ridge National Laboratory (ORNL), and the Savannah River Plant (SRP)]; and consists of four separate reports written by staff at these facilities. The fundamental goal of the soil decontamination task group has been the selective extraction/leaching or removal of uranium from soil faster, cheaper, and safer than current conventional technologies. The objective is to selectively remove uranium from soil without seriously degrading the soil`s physicochemical characteristics or generating waste forms that are difficult to manage and/or dispose of. Emphasis in research was placed more strongly on chemical extraction techniques than physical extraction techniques.

  8. Hybrid Ultra-Microporous Materials for Selective Xenon Adsorption and Separation.

    PubMed

    Mohamed, Mona H; Elsaidi, Sameh K; Pham, Tony; Forrest, Katherine A; Schaef, Herbert T; Hogan, Adam; Wojtas, Lukasz; Xu, Wenqian; Space, Brian; Zaworotko, Michael J; Thallapally, Praveen K

    2016-07-11

    The demand for Xe/Kr separation continues to grow due to the industrial significance of high-purity Xe gas. Current separation processes rely on energy intensive cryogenic distillation. Therefore, less energy intensive alternatives, such as physisorptive separation, using porous materials, are required. Herein we show that an underexplored class of porous materials called hybrid ultra-microporous materials (HUMs) affords new benchmark selectivity for Xe separation from Xe/Kr mixtures. The isostructural materials, CROFOUR-1-Ni and CROFOUR-2-Ni, are coordination networks that have coordinatively saturated metal centers and two distinct types of micropores, one of which is lined by CrO4 (2-) (CROFOUR) anions and the other is decorated by the functionalized organic linker. These nets offer unprecedented selectivity towards Xe. Modelling indicates that the selectivity of these nets is tailored by synergy between the pore size and the strong electrostatics afforded by the CrO4 (2-) anions. PMID:27238977

  9. Uranium industry annual 1998

    SciTech Connect

    1999-04-22

    The Uranium Industry Annual 1998 (UIA 1998) provides current statistical data on the US uranium industry`s activities relating to uranium raw materials and uranium marketing. It contains data for the period 1989 through 2008 as collected on the Form EIA-858, ``Uranium Industry Annual Survey.`` Data provides a comprehensive statistical characterization of the industry`s activities for the survey year and also include some information about industry`s plans and commitments for the near-term future. Data on uranium raw materials activities for 1989 through 1998, including exploration activities and expenditures, EIA-estimated reserves, mine production of uranium, production of uranium concentrate, and industry employment, are presented in Chapter 1. Data on uranium marketing activities for 1994 through 2008, including purchases of uranium and enrichment services, enrichment feed deliveries, uranium fuel assemblies, filled and unfilled market requirements, and uranium inventories, are shown in Chapter 2. The methodology used in the 1998 survey, including data edit and analysis, is described in Appendix A. The methodologies for estimation of resources and reserves are described in Appendix B. A list of respondents to the ``Uranium Industry Annual Survey`` is provided in Appendix C. The Form EIA-858 ``Uranium Industry Annual Survey`` is shown in Appendix D. For the readers convenience, metric versions of selected tables from Chapters 1 and 2 are presented in Appendix E along with the standard conversion factors used. A glossary of technical terms is at the end of the report. 24 figs., 56 tabs.

  10. RECOVERY OF URANIUM BY AROMATIC DITHIOCARBAMATE COMPLEXING

    DOEpatents

    Neville, O.K.

    1959-08-11

    A selective complexing organic solvent extraction process is presented for the separation of uranium values from an aqueous nitric acid solution of neutron irradiated thorium. The process comprises contacting the solution with an organic aromatic dithiccarbamaie and recovering the resulting urancdithiccarbamate complex with an organic solvent such as ethyl acetate.

  11. Uranium extraction: Coordination chemistry in the ocean

    NASA Astrophysics Data System (ADS)

    Lu, Yi

    2014-03-01

    The amount of uranium in seawater vastly exceeds that in land-based deposits; but separating it from other more abundant metal ions requires high affinity, selectivity -- and the ability to deal with an enormous volume of water. Now, two complementary approaches have made considerable contributions to overcoming these challenges.

  12. URANIUM RECOVERY PROCESS

    DOEpatents

    Yeager, J.H.

    1958-08-12

    In the prior art processing of uranium ores, the ore is flrst digested with nitric acid and filtered, and the uranium values are then extracted tom the filtrate by contacting with an organic solvent. The insoluble residue has been processed separately in order to recover any uranium which it might contain. The improvement consists in contacting a slurry, composed of both solution and residue, with the organic solvent prior to filtration. Tbe result is that uranium values contained in the residue are extracted along with the uranium values contained th the solution in one step.

  13. PROCESS OF RECOVERING URANIUM

    DOEpatents

    Carter, J.M.; Larson, C.E.

    1958-10-01

    A process is presented for recovering uranium values from calutron deposits. The process consists in treating such deposits to produce an oxidlzed acidic solution containing uranium together with the following imparities: Cu, Fe, Cr, Ni, Mn, Zn. The uranium is recovered from such an impurity-bearing solution by adjusting the pH of the solution to the range 1.5 to 3.0 and then treating the solution with hydrogen peroxide. This results in the precipitation of uranium peroxide which is substantially free of the metal impurities in the solution. The peroxide precipitate is then separated from the solution, washed, and calcined to produce uranium trioxide.

  14. Uranium(VI) Binding Forms in Selected Human Body Fluids: Thermodynamic Calculations versus Spectroscopic Measurements.

    PubMed

    Osman, Alfatih A A; Geipel, Gerhard; Barkleit, Astrid; Bernhard, Gert

    2015-02-16

    Human exposure to uranium increasingly becomes a subject of interest in many scientific disciplines such as environmental medicine, toxicology, and radiation protection. Knowledge about uranium chemical binding forms(speciation) in human body fluids can be of great importance to understand not only its biokinetics but also its relevance in risk assessment and in designing decorporation therapy in the case of accidental overexposure. In this study, thermodynamic calculations of uranium speciation in relevant simulated and original body fluids were compared with spectroscopic data after ex-situ uranium addition. For the first time, experimental data on U(VI) speciation in body fluids (saliva, sweat, urine) was obtained by means of cryogenic time-resolved laser-induced fluorescence spectroscopy (cryo-TRLFS) at 153 K. By using the time dependency of fluorescence decay and the band positions of the emission spectra, various uranyl complexes were demonstrated in the studied samples. The variations of the body fluids in terms of chemical composition, pH, and ionic strength resulted in different binding forms of U(VI). The speciation of U(VI) in saliva and in urine was affected by the presence of bioorganic ligands, whereas in sweat, the distribution depends mainly on inorganic ligands. We also elucidated the role of biological buffers, i.e., phosphate (H(2)PO(4−)/HPO(4)(2−)) on U(VI) distribution, and the system Ca(2+)/UO(2)(2+)/PO(4)(3−) was discussed in detail in both saliva and urine. The theoretical speciation calculations of the main U(VI) species in the investigated body fluids were significantly consistent with the spectroscopic data. Laser fluorescence spectroscopy showed success and reliability for direct determination of U(VI) in such biological matrices with the possibility for further improvement.

  15. Introduction of structural affinity handles as a tool in selective nucleic acid separations

    NASA Technical Reports Server (NTRS)

    Willson, III, Richard Coale (Inventor); Cano, Luis Antonio (Inventor)

    2011-01-01

    The method is used for separating nucleic acids and other similar constructs. It involves selective introduction, enhancement, or stabilization of affinity handles such as single-strandedness in the undesired (or desired) nucleic acids as compared to the usual structure (e.g., double-strandedness) of the desired (or undesired) nucleic acids. The undesired (or desired) nucleic acids are separated from the desired (or undesired) nucleic acids due to capture by methods including but not limited to immobilized metal affinity chromatography, immobilized single-stranded DNA binding (SSB) protein, and immobilized oligonucleotides. The invention is useful to: remove contaminating genomic DNA from plasmid DNA; remove genomic DNA from plasmids, BACs, and similar constructs; selectively separate oligonucleotides and similar DNA fragments from their partner strands; purification of aptamers, (deoxy)-ribozymes and other highly structured nucleic acids; Separation of restriction fragments without using agarose gels; manufacture recombinant Taq polymerase or similar products that are sensitive to host genomic DNA contamination; and other applications.

  16. Atomic vapor laser isotope separation

    NASA Astrophysics Data System (ADS)

    Paisner, J. A.

    1988-07-01

    Atomic Vapor Laser Isotope Separation (AVLIS) is a general and powerful technique applicable to many elements. A major present application to the enrichement of uranium for lightwater power reactor fuel has been under development at the Lawrence Livermore National Laboratory since 1973. In June 1985, the Department of Energy announced the selection of AVLIS as the technology to meet future U.S. needs for the internationally competitive production of uranium separative work. Major features of the AVLIS process will be discussed with consideration of the process figures of merit.

  17. Highly Selective Membranes For The Separation Of Organic Vapors Using Super-Glassy Polymers

    DOEpatents

    Pinnau, Ingo; Lokhandwala, Kaaeid; Nguyen, Phuong; Segelke, Scott

    1997-11-18

    A process for separating hydrocarbon gases of low boiling point, particularly methane, ethane and ethylene, from nitrogen. The process is performed using a membrane made from a super-glassy material. The gases to be separated are mixed with a condensable gas, such as a C.sub.3+ hydrocarbon. In the presence of the condensable gas, improved selectivity for the low-boiling-point hydrocarbon gas over nitrogen is achieved.

  18. Calculating Atomic Number Densities for Uranium

    1993-01-01

    Provides method to calculate atomic number densities of selected uranium compounds and hydrogenous moderators for use in nuclear criticality safety analyses at gaseous diffusion uranium enrichment facilities.

  19. Uranium in soils integrated demonstration: 1992 update

    SciTech Connect

    Nuhfer, K.R.

    1992-04-01

    The Uranium in Soils Integrated Demonstration (ID) was initiated in 1991. The Fernald Environmental Management Project (FEMP), previously known as the Feed Materials Production Center (FMPC), was selected as the host site for the Uranium in Soils ID. The principle focus in 1991 was to establish the management structure and objectives for the ID. In 1992 the technical activities in support of the ID goals were initiated. The emphasis this year has been on the development and demonstration of improved field screening technologies, obtaining chemical and physical data on the uranium waste forms in the host site soils, and initiating the development of uranium/soil separation technologies. This document will discuss the established TSG charters, accomplishments to date, current activities and future activities in support of the 1992 emphasis and the long term goals of the ID.

  20. Selective separation of Eu{sup 3+} using polymer-enhanced ultrafiltration

    SciTech Connect

    Norton, M.V.

    1994-03-01

    A process to selectively remove {sup 241}Am from liquid radioactive waste was investigated as an actinide separation method applicable to Hanford and other waste sites. The experimental procedures involved removal of Eu, a nonradioactive surrogate for Am, from aqueous solutions at pH 5 using organic polymers in conjunction with ultrafiltration. Commercially available polyacrylic acid (60,000 MW) and Pacific Northwest Laboratory`s (PNL) synthesized E3 copolymer ({approximately}10,000 MW) were tested. Test solutions containing 10 {mu}g/mL of Eu were dosed vath each polymer at various concentrations in order to bind Eu (i.e., by complexation and/or cation exchange) for subsequent rejection by an ultrafiltration coupon. Test solutions were filtered with and without polymer to determine if enhanced Eu separation could be achieved from polymer treatment. Both polymers significantly increased Eu removal. Optimum concentrations were 20 {mu}g/mL of polyacrylic acid and 100 {mu}g/mL of E3 for 100% Eu rejection by the Amicon PM10 membrane at 55 psi. In addition to enhancement of removal, the polymers selectively bound Eu over Na, suggesting that selective separation of Eu was possible. This suggests that polymer-enhanced ultrafiltration is a potential process for separation of {sup 241}Am from Hanford tank waste, further investigation of binding agents and membranes effective under very alkaline and high ionic strength is warranted. This process also has potential applications for selective separation of toxic metals from industrial process streams.

  1. Uranium removal from soils: An overview from the Uranium in Soils Integrated Demonstration program

    SciTech Connect

    Francis, C.W.; Brainard, J.R.; York, D.A.; Chaiko, D.J.; Matthern, G.

    1994-09-01

    An integrated approach to remove uranium from uranium-contaminated soils is being conducted by four of the US Department of Energy national laboratories. In this approach, managed through the Uranium in Soils Integrated Demonstration program at the Fernald Environmental Management Project, Fernald, Ohio, these laboratories are developing processes that selectively remove uranium from soil without seriously degrading the soil`s physicochemical characteristics or generating waste that is difficult to manage or dispose of. These processes include traditional uranium extractions that use carbonate as well as some nontraditional extraction techniques that use citric acid and complex organic chelating agents such as naturally occurring microbial siderophores. A bench-scale engineering design for heap leaching; a process that uses carbonate leaching media shows that >90% of the uranium can be removed from the Fernald soils. Other work involves amending soils with cultures of sulfur and ferrous oxidizing microbes or cultures of fungi whose role is to generate mycorrhiza that excrete strong complexers for uranium. Aqueous biphasic extraction, a physical separation technology, is also being evaluated because of its ability to segregate fine particulate, a fundamental requirement for soils containing high levels of silt and clay. Interactions among participating scientists have produced some significant progress not only in evaluating the feasibility of uranium removal but also in understanding some important technical aspects of the task.

  2. PRODUCTION OF URANIUM METAL BY CARBON REDUCTION

    DOEpatents

    Holden, R.B.; Powers, R.M.; Blaber, O.J.

    1959-09-22

    The preparation of uranium metal by the carbon reduction of an oxide of uranium is described. In a preferred embodiment of the invention a charge composed of carbon and uranium oxide is heated to a solid mass after which it is further heated under vacuum to a temperature of about 2000 deg C to produce a fused uranium metal. Slowly ccoling the fused mass produces a dendritic structure of uranium carbide in uranium metal. Reacting the solidified charge with deionized water hydrolyzes the uranium carbide to finely divide uranium dioxide which can be separated from the coarser uranium metal by ordinary filtration methods.

  3. Highly Selective H2 Separation Zeolite Membranes for Coal Gasification Membrane Reactor Applications

    SciTech Connect

    Mei Hong; Richard D. Noble; John L. Falconer

    2006-09-24

    Zeolite membranes are thermally, chemically, and mechanically stable. They also have tunable molecular sieving and catalytic ability. These unique properties make zeolite membrane an excellent candidate for use in catalytic membrane reactor applications related to coal conversion and gasification, which need high temperature and high pressure range separation in chemically challenging environment where existing technologies are inefficient or unable to operate. Small pore, good quality, and thin zeolite membranes are needed for highly selective H{sub 2} separation from other light gases (CO{sub 2}, CH{sub 4}, CO). However, zeolite membranes have not been successful for H{sub 2} separation from light gases because the zeolite pores are either too big or the membranes have a large number of defects. The objective of this study is to develop zeolite membranes that are more suitable for H{sub 2} separation. In an effort to tune the size of zeolite pores and/or to decrease the number of defects, medium-pore zeolite B-ZSM-5 (MFI) membranes were synthesized and silylated. Silylation on B-ZSM-5 crystals reduced MFI-zeolite pore volume, but had little effect on CO{sub 2} and CH{sub 4} adsorption. Silylation on B-ZSM-5 membranes increased H{sub 2} selectivity both in single component and in mixtures with CO{sub 2}CO{sub 2}, CH{sub 4}, or N2. Single gas and binary mixtures of H{sub 2}/CO{sub 2} and H{sub 2}/CH{sub 4} were separated through silylated B-ZSM-5 membranes at feed pressures up to 1.7 MPa and temperatures up to 773 K. For one BZSM-5 membrane after silylation, the H2/CO{sub 2} separation selectivity at 473 K increased from 1.4 to 37, whereas the H{sub 2}/CH{sub 4} separation selectivity increased from 1.6 to 33. Hydrogen permeance through a silylated B-ZSM-5 membrane was activated, but the CO{sub 2} and CH4 permeances decreased slightly with temperature in both single gas and in mixtures. Therefore, the H{sub 2} permeance and H{sub 2}/CO{sub 2} and H{sup 2} /CH{sub 4

  4. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Portsmouth Gaseous Diffusion Plant site

    SciTech Connect

    Marmer, G.J.; Dunn, C.P.; Filley, T.H.; Moeller, K.L.; Pfingston, J.M.; Policastro, A.J.; Cleland, J.H.

    1991-09-01

    Uranium enrichment in the United States has utilized a diffusion process to preferentially enrich the U-235 isotope in the uranium product. In the 1970s, the US Department of Energy (DOE) began investigating more efficient and cost-effective enrichment technologies. In January 1990, the Secretary of Energy approved a plan for the demonstration and deployment of the Uranium Atomic Vapor Laser isotope Separation (U-AVLIS) technology with the near-term goal to provide the necessary information to make a deployment decision by November 1992. Initial facility operation is anticipated for 1999. A programmatic document for use in screening DOE sites to locate a U-AVLIS production plant was developed and implemented in two parts. The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. The final evaluation, which included sensitivity studies, identified the Oak Ridge Gaseous Diffusion Plant (ORGDP) site, the Paducah Gaseous Diffusion Plant (PGDP) site, and the Portsmouth Gaseous Diffusion Plant (PORTS) site as having significant advantages over the other sites considered. This environmental site description (ESD) provides a detailed description of the PORTS site and vicinity suitable for use in an environmental impact statement (EIS). This report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during site visits. The organization of the ESD is as follows. Topics addressed in Sec. 2 include a general site description and the disciplines of geology, water resources, biotic resources, air resources, noise, cultural resources, land use. Socioeconomics, and waste management. Identification of any additional data that would be required for an EIS is presented in Sec. 3.

  5. Southern complex: geology, geochemistry, mineralogy, and mineral chemistry of selected uranium- and thorium-rich granites

    SciTech Connect

    Hoffman, M.A.

    1987-01-01

    Four major rock groups are defined in the Southern Complex: the Bell Creek Granite (BCG), the Clotted Granitoids (CGR), the Albite Granite (AGR), and the Migmatite Complex. Metatexites of the Migmatite Complex are the oldest rocks and include paleosome of a metasedimentary and metavolcanic protolith represented by Banded Iron Formation, Banded Amphibolite, and Banded Gneisses, and interlayered or crosscutting leucogranites. The CGR span the range from metatexite to diatexite and represent in-situ partial melting of metapelitic layers in the protolith during intrusion of the BCG. The BCG cuts the migmatites, is locally cut by the CGR, and was derived by partial melting of a dominantly metasedimentary protolith at some depth below the presently exposed migmatites during a regional tectonothermal event. The Albite Granite is a 2km diameter, muscovite-fluorite-columbite-bearing intrusive stock that cuts all other major units. The thorium history of the BCG is a function of the history of monazite. The thorium history of the CGR is also dominated by monazite but the thorium content of this unit cannot be entirely accounted for by original restite monazite. The uranium history of the BCG and CGR was dominated by magmatic differentiation and post magmatic, metamorphic and supergene redistributions and is largely independent of the thorium history. The thorium and uranium history of the AGR was dominated by magmatic/deuteric processes unlike the BCG and CGR.

  6. Selection of Water-Dispersible Carbon Black for Fabrication of Uranium Oxicarbide Microspheres

    SciTech Connect

    Contescu, Cristian I; Baker, Frederick S; Hunt, Rodney Dale; Collins, Jack Lee; Burchell, Timothy D

    2008-01-01

    Fabrication of uranium oxicarbide (UCO) microspheres, a component of TRISO fuel particles for high temperature nuclear power systems, is based on the internal gelation process of uranium salts in presence of carbon black. In order to obtain a high quality product, carbon black should remain dispersed during all phases of the gelation process. In this study, the surface and structural properties of several commercial carbon black materials, and their use in combination with ionic and non-ionic dispersing agents was examined with the goal of finding optimal conditions for stabilizing submicron-sized carbon black dispersions. Traditional methods for stabilizing dispersions, based on the use of dispersing agents, failed to stabilize carbon dispersions against large pH variations, typical for the internal gelation process. An alternate dispersing method was proposed, based on using surface-modified carbons functionalized with strongly ionizing surface groups (sodium sulfonate). With a proper choice of surface modifiers, these advanced carbons disperse easily to particles in the range of 0.15 V0.20 m and the dispersions remain stable during the conditions of internal gelation.

  7. New Proton-Ionizable, Calixarene-Based Ligands for Selective Metal Ion Separations

    SciTech Connect

    Bartsch, Richard A.

    2012-06-04

    The project objective was the discovery of new ligands for performing metal ion separations. The research effort entailed the preparation of new metal ion complexing agents and polymers and their evaluation in metal ion separation processes of solvent extraction, synthetic liquid membrane transport, and sorption. Structural variations in acyclic, cyclic, and bicyclic organic ligands were used to probe their influence upon the efficiency and selectivity with which metal ion separations can be performed. A unifying feature of the ligand structures is the presence of one (or more) side arm with a pendent acidic function. When a metal ion is complexed within the central cavity of the ligand, ionization of the side arm(s) produces the requisite anion(s) for formation of an overall electroneutral complex. This markedly enhances extraction/transport efficiency for separations in which movement of aqueous phase anions of chloride, nitrate, or sulfate into an organic medium would be required. Through systematic structural variations, new ligands have been developed for efficient and selective separations of monovalent metal ions (e.g., alkali metal, silver, and thallium cations) and of divalent metal ion species (e.g., alkaline earth metal, lead, and mercury cations). Research results obtained in these fundamental investigations provide important insight for the design and development of ligands suitable for practical metal ion separation applications.

  8. METHOD OF SEPARATING PLUTONIUM

    DOEpatents

    Heal, H.G.

    1960-02-16

    BS>A method of separating plutonium from aqueous nitrate solutions of plutonium, uranium. and high beta activity fission products is given. The pH of the aqueous solution is adjusted between 3.0 to 6.0 with ammonium acetate, ferric nitrate is added, and the solution is heated to 80 to 100 deg C to selectively form a basic ferric plutonium-carrying precipitate.

  9. METHOD FOR RECOVERING URANIUM FROM OILS

    DOEpatents

    Gooch, L.H.

    1959-07-14

    A method is presented for recovering uranium from hydrocarbon oils, wherein the uranium is principally present as UF/sub 4/. According to the invention, substantially complete removal of the uranium from the hydrocarbon oil may be effected by intimately mixing one part of acetone to about 2 to 12 parts of the hydrocarbon oil containing uranium and separating the resulting cake of uranium from the resulting mixture. The uranium in the cake may be readily recovered by burning to the oxide.

  10. Recent Development of Advanced Materials with Special Wettability for Selective Oil/Water Separation.

    PubMed

    Ma, Qinglang; Cheng, Hongfei; Fane, Anthony G; Wang, Rong; Zhang, Hua

    2016-04-27

    The increasing number of oil spill accidents have a catastrophic impact on our aquatic environment. Recently, special wettable materials used for the oil/water separation have received significant research attention. Due to their opposing affinities towards water and oil, i.e., hydrophobic and oleophilic, or hydrophilic and oleophobic, such materials can be used to remove only one phase from the oil/water mixture, and simultaneously repel the other phase, thus achieving selective oil/water separation. Moreover, the synergistic effect between the surface chemistry and surface architecture can further promote the superwetting behavior, resulting in the improved separation efficiency. Here, recently developed materials with special wettability for selective oil/water separation are summarized and discussed. These materials can be categorized based on their oil/water separating mechanisms, i.e., filtration and absorption. In each section, representative studies will be highlighted, with emphasis on the materials wetting properties and innovative aspects. Finally, challenges and future research directions in this emerging and promising research field will be briefly described. PMID:27000640

  11. Adsorbate shape selectivity: Separation of the HF/134a azeotrope over carbogenic molecular sieve

    SciTech Connect

    Hong, A.; Mariwala, R.K.; Kane, M.S.; Foley, H.C.

    1995-03-01

    Experimental evidence is provided for adsorptive shape selectivity in the separation of the azeotrope between HF and 1,1,1,2-tetrafluoroethane (134a) over pyrolyzed poly(furfuryl alcohol)-derived carbogenic molecular sieve (PPFA-CMS). The separation can be accomplished over coconut charcoal or Carbosieve G on the basis of the differences in the extent of equilibrium adsorption of HF and 134a. On these adsorbents 134a is more strongly bound than HF, thus it elutes much more slowly from the bed. The heat of adsorption for 134a in the vicinity of 200 C on Carbosieve G is {approximately}8.8 kcal/mol. In contrast, when the same azeotropic mixture is separated over PPFA-CMS prepared at 500 C, 134a is not adsorbed. As a result 134a elutes from the bed first, followed by HF. The reversal is brought about by the narrower pore size and pore size distribution of the PPFA-CMS versus that for Carbosieve G. Thus the separation over PPFA-CMS is an example of adsorbate shape selectivity and represents a limiting case of kinetic separation.

  12. Recent Development of Advanced Materials with Special Wettability for Selective Oil/Water Separation.

    PubMed

    Ma, Qinglang; Cheng, Hongfei; Fane, Anthony G; Wang, Rong; Zhang, Hua

    2016-04-27

    The increasing number of oil spill accidents have a catastrophic impact on our aquatic environment. Recently, special wettable materials used for the oil/water separation have received significant research attention. Due to their opposing affinities towards water and oil, i.e., hydrophobic and oleophilic, or hydrophilic and oleophobic, such materials can be used to remove only one phase from the oil/water mixture, and simultaneously repel the other phase, thus achieving selective oil/water separation. Moreover, the synergistic effect between the surface chemistry and surface architecture can further promote the superwetting behavior, resulting in the improved separation efficiency. Here, recently developed materials with special wettability for selective oil/water separation are summarized and discussed. These materials can be categorized based on their oil/water separating mechanisms, i.e., filtration and absorption. In each section, representative studies will be highlighted, with emphasis on the materials wetting properties and innovative aspects. Finally, challenges and future research directions in this emerging and promising research field will be briefly described.

  13. Large-Flow-Area Flow-Selective Liquid/Gas Separator

    NASA Technical Reports Server (NTRS)

    Vasquez, Arturo; Bradley, Karla F.

    2010-01-01

    This liquid/gas separator provides the basis for a first stage of a fuel cell product water/oxygen gas phase separator. It can separate liquid and gas in bulk in multiple gravity environments. The system separates fuel cell product water entrained with circulating oxygen gas from the outlet of a fuel cell stack before allowing the gas to return to the fuel cell stack inlet. Additional makeup oxygen gas is added either before or after the separator to account for the gas consumed in the fuel cell power plant. A large volume is provided upstream of porous material in the separator to allow for the collection of water that does not exit the separator with the outgoing oxygen gas. The water then can be removed as it continues to collect, so that the accumulation of water does not impede the separating action of the device. The system is designed with a series of tubes of the porous material configured into a shell-and-tube heat exchanger configuration. The two-phase fluid stream to be separated enters the shell-side portion of the device. Gas flows to the center passages of the tubes through the porous material and is then routed to a common volume at the end of the tubes by simple pressure difference from a pumping device. Gas flows through the porous material of the tubes with greater ease as a function of the ratio of the dynamic viscosity of the water and gas. By careful selection of the dimensions of the tubes (wall thickness, porosity, diameter, length of the tubes, number of the tubes, and tube-to-tube spacing in the shell volume) a suitable design can be made to match the magnitude of water and gas flow, developed pressures from the oxygen reactant pumping device, and required residual water inventory for the shellside volume.

  14. Sulfate Separation by Selective Crystallization with a Bis-iminoguanidinium Ligand

    DOE PAGES

    Seipp, Charles A.; Williams, Neil J.; Custelcean, Radu

    2016-01-01

    One simple and effective method for selective sulfate separation from aqueous solutions by crystallization with a bis-guanidinium ligand, 1,4-benzene-bis(iminoguanidinium) (BBIG), is demonstrated. The ligand is synthesized as the chloride salt (BBIG-Cl) by in situ imine condensation of terephthalaldehyde with aminoguanidinium chloride in water, followed by crystallization as the sulfate salt (BBIG-SO4). Alternatively, BBIG-Cl is synthesized ex situ in larger scale from ethanol. Furthermore, the sulfate separation ability of the BBIG ligand is demonstrated by selective and quantitative crystallization of sulfate from seawater. These ligands can then be recycled by neutralization of BBIG-SO4 with aqueous NaOH and crystallization of the neutralmore » bis-iminoguanidine, which can be converted back into BBIG-Cl with aqueous HCl and reused in another separation cycle. Finally, 35S-labeled sulfate and β liquid scintillation counting are employed for monitoring the sulfate concentration in solution. Overall, this protocol will instruct the user in the necessary skills to synthesize a ligand, employ it in the selective crystallization of sulfate from aqueous solutions, and quantify the separation efficiency.« less

  15. Sulfate Separation by Selective Crystallization with a Bis-iminoguanidinium Ligand

    SciTech Connect

    Seipp, Charles A.; Williams, Neil J.; Custelcean, Radu

    2016-01-01

    One simple and effective method for selective sulfate separation from aqueous solutions by crystallization with a bis-guanidinium ligand, 1,4-benzene-bis(iminoguanidinium) (BBIG), is demonstrated. The ligand is synthesized as the chloride salt (BBIG-Cl) by in situ imine condensation of terephthalaldehyde with aminoguanidinium chloride in water, followed by crystallization as the sulfate salt (BBIG-SO4). Alternatively, BBIG-Cl is synthesized ex situ in larger scale from ethanol. Furthermore, the sulfate separation ability of the BBIG ligand is demonstrated by selective and quantitative crystallization of sulfate from seawater. These ligands can then be recycled by neutralization of BBIG-SO4 with aqueous NaOH and crystallization of the neutral bis-iminoguanidine, which can be converted back into BBIG-Cl with aqueous HCl and reused in another separation cycle. Finally, 35S-labeled sulfate and β liquid scintillation counting are employed for monitoring the sulfate concentration in solution. Overall, this protocol will instruct the user in the necessary skills to synthesize a ligand, employ it in the selective crystallization of sulfate from aqueous solutions, and quantify the separation efficiency.

  16. Sulfate Separation by Selective Crystallization with a Bis-iminoguanidinium Ligand.

    PubMed

    Seipp, Charles A; Williams, Neil J; Custelcean, Radu

    2016-01-01

    A simple and effective method for selective sulfate separation from aqueous solutions by crystallization with a bis-guanidinium ligand, 1,4-benzene-bis(iminoguanidinium) (BBIG), is demonstrated. The ligand is synthesized as the chloride salt (BBIG-Cl) by in situ imine condensation of terephthalaldehyde with aminoguanidinium chloride in water, followed by crystallization as the sulfate salt (BBIG-SO4). Alternatively, BBIG-Cl is synthesized ex situ in larger scale from ethanol. The sulfate separation ability of the BBIG ligand is demonstrated by selective and quantitative crystallization of sulfate from seawater. The ligand can be recycled by neutralization of BBIG-SO4 with aqueous NaOH and crystallization of the neutral bis-iminoguanidine, which can be converted back into BBIG-Cl with aqueous HCl and reused in another separation cycle. Finally, (35)S-labeled sulfate and β liquid scintillation counting are employed for monitoring the sulfate concentration in solution. Overall, this protocol will instruct the user in the necessary skills to synthesize a ligand, employ it in the selective crystallization of sulfate from aqueous solutions, and quantify the separation efficiency. PMID:27684987

  17. Selective separation of similarly sized proteins with tunable nanoporous block copolymer membranes.

    PubMed

    Qiu, Xiaoyan; Yu, Haizhou; Karunakaran, Madhavan; Pradeep, Neelakanda; Nunes, Suzana P; Peinemann, Klaus-Viktor

    2013-01-22

    An integral asymmetric membrane was fabricated in a fast and one-step process by combining the self-assembly of an amphiphilic block copolymer (PS-b-P4VP) with nonsolvent-induced phase separation. The structure was found to be composed of a thin layer of densely packed highly ordered cylindrical channels with uniform pore sizes perpendicular to the surface on top of a nonordered sponge-like layer. The as-assembled membrane obtained a water flux of more than 3200 L m(-2) h(-1) bar(-1), which was at least an order of magnitude higher than the water fluxes of commercially available membranes with comparable pore sizes, making this membrane particularly well suited to size-selective and charge-based separation of biomolecules. To test the performance of the membrane, we conducted diffusion experiments at the physiological pH of 7.4 using bovine serum albumin (BSA) and globulin-γ, two proteins with different diameters but too close in size (2-fold difference in molecular mass) to be efficiently separated via conventional dialysis membrane processes. The diffusion rate differed by a factor of 87, the highest value reported to date. We also analyzed charge-based diffusive transport and separation of two proteins of similar molecular weight (BSA and bovine hemoglobin (BHb)) through the membrane as a function of external pH. The membrane achieved a selectivity of about 10 at pH 4.7, the isoelectric point (pI) of BSA. We then positively charged the membrane to improve the separation selectivity. With the modified membrane BSA was completely blocked when the pH was 7.0, the pI of BHb, while BHb was completely blocked at pH 4.7. Our results demonstrate the potential of our asymmetric membrane to efficiently separate biological substances/pharmaceuticals in bioscience, biotechnology, and biomedicine applications.

  18. Selective separation of similarly sized proteins with tunable nanoporous block copolymer membranes.

    PubMed

    Qiu, Xiaoyan; Yu, Haizhou; Karunakaran, Madhavan; Pradeep, Neelakanda; Nunes, Suzana P; Peinemann, Klaus-Viktor

    2013-01-22

    An integral asymmetric membrane was fabricated in a fast and one-step process by combining the self-assembly of an amphiphilic block copolymer (PS-b-P4VP) with nonsolvent-induced phase separation. The structure was found to be composed of a thin layer of densely packed highly ordered cylindrical channels with uniform pore sizes perpendicular to the surface on top of a nonordered sponge-like layer. The as-assembled membrane obtained a water flux of more than 3200 L m(-2) h(-1) bar(-1), which was at least an order of magnitude higher than the water fluxes of commercially available membranes with comparable pore sizes, making this membrane particularly well suited to size-selective and charge-based separation of biomolecules. To test the performance of the membrane, we conducted diffusion experiments at the physiological pH of 7.4 using bovine serum albumin (BSA) and globulin-γ, two proteins with different diameters but too close in size (2-fold difference in molecular mass) to be efficiently separated via conventional dialysis membrane processes. The diffusion rate differed by a factor of 87, the highest value reported to date. We also analyzed charge-based diffusive transport and separation of two proteins of similar molecular weight (BSA and bovine hemoglobin (BHb)) through the membrane as a function of external pH. The membrane achieved a selectivity of about 10 at pH 4.7, the isoelectric point (pI) of BSA. We then positively charged the membrane to improve the separation selectivity. With the modified membrane BSA was completely blocked when the pH was 7.0, the pI of BHb, while BHb was completely blocked at pH 4.7. Our results demonstrate the potential of our asymmetric membrane to efficiently separate biological substances/pharmaceuticals in bioscience, biotechnology, and biomedicine applications. PMID:23252799

  19. [Synthesis and applications of chiral metal-organic framework in the selective separation of enantiomers].

    PubMed

    Qi, Xiaoyue; Li, Xianjiang; Bai, Yu; Liu, Huwei

    2016-01-01

    Chirality is a universal phenomenon in nature. Chiral separation is vitally important in drug development, agricultural chemistry, pharmacology, environmental science, biology and many other fields. Chiral metal-organic frameworks (MOFs) are a new group of porous materials with special topology and designable pore structures, as well as their high specific surface area, porosity, excellent thermal stability, solvent resistance, etc. Thus, chiral MOFs are promising with various applications in the field of analytical chemistry. This review summarizes the synthesis strategies of chiral MOFs and their applications in the selective separation of enantiomers, as well as related mechanism.

  20. Design and Development of Selective Extractants for An/Ln Separations

    SciTech Connect

    Robert T. Paine

    2009-12-04

    This study has succeeded in further developing phosphinoylmethyl pyridine compounds as selective recognition and separations agents for trivalent lanthanide and actinide ions present in nuclear materials. The parameters for efficient separations have been further elucidated and factors important to further development have been identified. Further development will lead to optimal extractant design for effective actinide ion partitioning under process practical conditions. The primary objective of the project involved the design, synthesis, and characterization of the extraction performance of 2,6-bis(phosphinomethyl)pyridine N,P,P{prime}-trioxides (NOPOPO) as potential reagents for the separation of Am, Cm, and fission product lanthanides from other transuranics and fission products and for acting as a separations 'platform' for the mutual separation of Am/Cm from the lanthanides. The secondary but critical objective of the project focused on the characterization of aqueous acid and radiation stability of NOPOPO ligands. Further, the project served as a interdisciplinary training vehicle for new, young investigators in actinide separations chemistry.

  1. METHOD OF SEPARATING Pu FROM METATHESIZED BiPO$sub 4$ CARRIER

    DOEpatents

    Knox, W.J.; Thompson, S.G.

    1960-05-31

    A process is given for separating uranium, neptunium, and/or plutonium from a bismuth hydroxide carrier by selective dissolution of these actinides with nitric acid of a concentration of from 0.05 to 0.5N.

  2. 300 AREA URANIUM CONTAMINATION

    SciTech Connect

    BORGHESE JV

    2009-07-02

    {sm_bullet} Uranium fuel production {sm_bullet} Test reactor and separations experiments {sm_bullet} Animal and radiobiology experiments conducted at the. 331 Laboratory Complex {sm_bullet} .Deactivation, decontamination, decommissioning,. and demolition of 300 Area facilities

  3. Selective separation of oil and water with mesh membranes by capillarity.

    PubMed

    Yu, Yuanlie; Chen, Hua; Liu, Yun; Craig, Vincent S J; Lai, Zhiping

    2016-09-01

    The separation of oil and water from wastewater generated in the oil-production industries, as well as in frequent oil spillage events, is important in mitigating severe environmental and ecological damage. Additionally, a wide arrange of industrial processes require oils or fats to be removed from aqueous systems. The immiscibility of oil and water allows for the wettability of solid surfaces to be engineered to achieve the separation of oil and water through capillarity. Mesh membranes with extreme, selective wettability can efficiently remove oil or water from oil/water mixtures through a simple filtration process using gravity. A wide range of different types of mesh membranes have been successfully rendered with extreme wettability and applied to oil/water separation in the laboratory. These mesh materials have typically shown good durability, stability as well as reusability, which makes them promising candidates for an ever widening range of practical applications.

  4. Selective separation of oil and water with mesh membranes by capillarity.

    PubMed

    Yu, Yuanlie; Chen, Hua; Liu, Yun; Craig, Vincent S J; Lai, Zhiping

    2016-09-01

    The separation of oil and water from wastewater generated in the oil-production industries, as well as in frequent oil spillage events, is important in mitigating severe environmental and ecological damage. Additionally, a wide arrange of industrial processes require oils or fats to be removed from aqueous systems. The immiscibility of oil and water allows for the wettability of solid surfaces to be engineered to achieve the separation of oil and water through capillarity. Mesh membranes with extreme, selective wettability can efficiently remove oil or water from oil/water mixtures through a simple filtration process using gravity. A wide range of different types of mesh membranes have been successfully rendered with extreme wettability and applied to oil/water separation in the laboratory. These mesh materials have typically shown good durability, stability as well as reusability, which makes them promising candidates for an ever widening range of practical applications. PMID:27246717

  5. Gas Separation Using Organic-Vapor-Resistent Membranes In Conjunctin With Organic-Vapor-Selective Membranes

    DOEpatents

    Baker, Richard W.; Pinnau, Ingo; He, Zhenjie; Da Costa, Andre R.; Daniels, Ramin; Amo, Karl D.; Wijmans, Johannes G.

    2003-06-03

    A process for treating a gas mixture containing at least an organic compound gas or vapor and a second gas, such as natural gas, refinery off-gas or air. The process uses two sequential membrane separation steps, one using membrane selective for the organic compound over the second gas, the other selective for the second gas over the organic vapor. The second-gas-selective membranes use a selective layer made from a polymer having repeating units of a fluorinated polymer, and demonstrate good resistance to plasticization by the organic components in the gas mixture under treatment, and good recovery after exposure to liquid aromatic hydrocarbons. The membrane steps can be combined in either order.

  6. Extraction behavior and selective separation of lead(II) using N,N-dioctyldiglycol amic acid.

    PubMed

    Shimojo, Kojiro; Nakai, Ayaka; Okamura, Hiroyuki; Ohashi, Akira; Naganawa, Hirochika

    2013-01-01

    Selective separation of lead ions (Pb(2+)) from aqueous solutions containing multiple divalent metal ions (Pb(2+), Cu(2+), Cd(2+), Zn(2+), Mn(2+), Co(2+), and Ni(2+)) was investigated using liquid-liquid extraction. N,N-Dioctyldiglycol amic acid (DODGAA) enabled quantitative extraction and efficient separation of Pb(2+) from the metal ion mixture under mildly acidic conditions. Compared with conventional commercial extractants, DODGAA provided better extraction and excellent selectivity for Pb(2+). The extraction of Pb(2+) with DODGAA proceeded through a proton-exchange reaction and formed a 1:2 complex, Pb(DODGAA)(2). The Pb(2+) was readily stripped from the extracting phase under acidic conditions, and the organic solution with DODGAA could be recycled.

  7. Self-Healing and Moldable Metallogels as the Recyclable Materials for Selective Dye Adsorption and Separation.

    PubMed

    Karan, Chandan Kumar; Bhattacharjee, Manish

    2016-03-01

    Four multiresponsive and self-sustaining metallogels were synthesized by the reaction of the disodium salt of the ligand carboxymethyl-(3,5-di-tert-butyl-2-hydroxy-benzyl)amino acetic acid with Cd(II) and Zn(II) halides, which were found to show excellent selectivity for dye adsorption and separation, and one of the gels shows a rare self-healing property. PMID:26854670

  8. PREPARATION OF URANIUM-ALUMINUM ALLOYS

    DOEpatents

    Moore, R.H.

    1962-09-01

    A process is given for preparing uranium--aluminum alloys from a solution of uranium halide in an about equimolar molten alkali metal halide-- aluminum halide mixture and excess aluminum. The uranium halide is reduced and the uranium is alloyed with the excess aluminum. The alloy and salt are separated from each other. (AEC)

  9. Highly Selective H2 Separation Zeolite Membranes for Coal Gasification Membrane Reactor Applications

    SciTech Connect

    Mei Hong; Richard Noble; John Falconer

    2007-09-24

    Zeolite membranes are thermally, chemically, and mechanically stable. They also have tunable molecular sieving and catalytic ability. These unique properties make zeolite membrane an excellent candidate for use in catalytic membrane reactor applications related to coal conversion and gasification, which need high temperature and high pressure range separation in chemically challenging environment where existing technologies are inefficient or unable to operate. Small pore, good quality, and thin zeolite membranes are needed for highly selective H2 separation from other light gases (CO2, CH4, CO). However, current zeolite membranes have either too big zeolite pores or a large number of defects and have not been successful for H2 separation from light gases. The objective of this study is to develop zeolite membranes that are more suitable for H2 separation. In an effort to tune the size of zeolite pores and/or to decrease the number of defects, medium-pore zeolite B-ZSM-5 (MFI) membranes were synthesized and silylated. Silylation on B-ZSM-5 crystals reduced MFI-zeolite pore volume, but had little effect on CO2 and CH4 adsorption. Silylation on B-ZSM-5 membranes increased H2 selectivity both in single component and in mixtures with CO2, CH4, or N2. Single gas and binary mixtures of H2/CO2 and H2/CH4 were permeated through silylated B-ZSM-5 membranes at feed pressures up to 1.7 MPa and temperatures up to 773 K. For one B-ZSM-5 membrane after silylation, the H2/CO2 separation selectivity at 473 K increased from 1.4 to 37, whereas the H2/CH4 separation selectivity increased from 1.6 to 33. Hydrogen permeance through a silylated BZSM-5 membrane was activated with activation energy of {approx}10 kJ/mol, but the CO2 and CH4 permeances decreased slightly with temperature in both single gas and in mixtures. Therefore, the H2 permeance and H2/CO2 and H2/CH4 separation selectivities increased with temperature. At 673 K, the H2 permeance was 1.0x10-7 mol{center_dot}m-2{center

  10. Novel syntergistic agent for selective separation of yttrium from other rare earth metals

    SciTech Connect

    Miyata, Terufumi; Goto, Masahiro; Nakashio, Fumiyuki

    1995-06-01

    An oil-soluble synergistic agent has been developed for the selective separation of yttrium (Y) from the other rare earth metals. The synergistic agent is a polyaminocarboxylic acid alkylderivative and has interfacial activity like that of surfactants. Separation of yttrium from heavy rare earth metals (erbium (Er) and holmium (Ho)) in the presence of the synergistic agent was carried out with a 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester as a carrier using a hollow-fiber membrane extractor. The new agent shows a synergistic effect on the permeation rate of rare earth metals at the oil-water interface. By the addition of a small amount of the agent, the selectivity for yttrium from the two rare earth metals was enhanced remarkably, because of the permeation rate of Y was selectively decreased compared with those of Er and Ho. The synergistic effect is discussed from the viewpoint of the stability constant for rare earth metals and the interfacial activity of the synergistic agent. The difference in interaction between the synergistic agent and rare earth ions at the oil-water interface results in an increase in the separation efficiency.

  11. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Oak Ridge Gaseous Diffusion Plant Site

    SciTech Connect

    Not Available

    1991-09-01

    In January 1990, the Secretary of Energy approved a plan for the demonstration and deployment of the Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) technology, with the near-term goal to provide the necessary information to make a deployment decision by November 1992. The U-AVLIS process is based on electrostatic extraction of photoionized U-235 atoms from an atomic vapor stream created by electron-beam vaporization of uranium metal alloy. A programmatic document for use in screening DOE sites to locate the U-AVLIS production plant was developed and implemented in two parts (Wolsko et al. 1991). The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. These sites were then subjected to a more rigorous and detailed comparative analysis for the purpose of developing a short list of reasonable alternative sites for later environmental examination. This environmental site description (ESD) provides a detailed description of the ORGDP site and vicinity suitable for use in an environmental impact statement (EIS). The report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during a site visit. The organization of the ESD is as follows. Topics addressed in Sec. 2 include a general site description and the disciplines of geology, water resources, biotic resources, air resources, noise, cultural resources, land use, socioeconomics, and waste management. Identification of any additional data that would be required for an EIS is presented in Sec. 3. Following the site description and additional data requirements, Sec. 4 provides a short, qualitative assessment of potential environmental issues. 37 refs., 20 figs., 18 tabs.

  12. Selective separation of virgin and post-consumer polymers (PET and PVC) by flotation method.

    PubMed

    Burat, Firat; Güney, Ali; Olgaç Kangal, M

    2009-06-01

    More and more polymer wastes are generated by industry and householders today. Recycling is an important process to reduce the amount of waste resulting from human activities. Currently, recycling technologies use relatively homogeneous polymers because hand-sorting waste is costly. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. At present, most waste polymers cause serious environmental problems. Burning polymers for recycling is not practiced since poisonous gases are released during the burning process. Particularly, polyvinyl chloride (PVC) materials among waste polymers generate hazardous HCl gas, dioxins containing Cl, etc., which lead to air pollution and shorten the life of the incinerator. In addition, they make other polymers difficult to recycle. Both polyethylene terephthalate (PET) and PVC have densities of 1.30-1.35g /cm(3) and cannot be separated using conventional gravity separation techniques. For this reason, polymer recycling needs new techniques. Among these techniques, froth flotation, which is also used in mineral processing, can be useful because of its low cost and simplicity. The main objective of this research is to recycle PET and PVC selectively from post-consumer polymer wastes and virgin polymers by using froth flotation. According to the results, all PVC particles were floated with 98.8% efficiency in virgin polymer separation while PET particles were obtained with 99.7% purity and 57.0% efficiency in post-consumer polymer separation.

  13. Selective separation of virgin and post-consumer polymers (PET and PVC) by flotation method

    SciTech Connect

    Burat, Firat; Gueney, Ali; Olgac Kangal, M.

    2009-06-15

    More and more polymer wastes are generated by industry and householders today. Recycling is an important process to reduce the amount of waste resulting from human activities. Currently, recycling technologies use relatively homogeneous polymers because hand-sorting waste is costly. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. At present, most waste polymers cause serious environmental problems. Burning polymers for recycling is not practiced since poisonous gases are released during the burning process. Particularly, polyvinyl chloride (PVC) materials among waste polymers generate hazardous HCl gas, dioxins containing Cl, etc., which lead to air pollution and shorten the life of the incinerator. In addition, they make other polymers difficult to recycle. Both polyethylene terephthalate (PET) and PVC have densities of 1.30-1.35 g/cm{sup 3} and cannot be separated using conventional gravity separation techniques. For this reason, polymer recycling needs new techniques. Among these techniques, froth flotation, which is also used in mineral processing, can be useful because of its low cost and simplicity. The main objective of this research is to recycle PET and PVC selectively from post-consumer polymer wastes and virgin polymers by using froth flotation. According to the results, all PVC particles were floated with 98.8% efficiency in virgin polymer separation while PET particles were obtained with 99.7% purity and 57.0% efficiency in post-consumer polymer separation.

  14. Selection and Characterization of Carbon Black and Surfactants for Development of Small Scale Uranium Oxicarbide Kernels

    SciTech Connect

    Contescu, Cristian I

    2006-01-01

    range of values generally associated with better dispersability, is provided in the Appendix. Special attention was given to characterization of several surface-modified carbon blacks produced by Cabot Corporation through proprietary diazonium salts chemistry. As demonstrated in the report, these advanced carbons offer many advantages over traditional dispersions. They disperse very easily, do not require intensive mechanical shearing or sonication, and the particle size of the dispersed carbon black aggregates is in the target range of 0.15-0.20 {micro}m. The dispersions in water and HMTA/urea solutions are stable for at least 30 days; in conditions of simulated broth, the dispersions are stable for at least 6 hours. It is proposed that the optimization of the carbon black dispersing process is possible by replacing traditional carbon blacks and surfactants with surface-modified carbon blacks having suitable chemical groups attached on their surface. It is recognized that the method advanced in this report for optimizing the carbon black dispersion process is based on a limited number of tests made in aqueous and simulated broth conditions. The findings were corroborated by a limited number of tests carried out with ADUN solutions by the Nuclear Science and Technology Division at Oak Ridge National Laboratory (ORNL). More work is necessary, however, to confirm the overall recommendation based on the findings discussed in this report: namely, that the use of surface-modified carbon blacks in the uranium-containing broth will not adversely impact the chemistry of the gelation process, and that high quality uranium oxicarbide (UCO) kernels will be produced after calcination.

  15. Selective adsorption and separation of organic dyes from aqueous solution on polydopamine microspheres.

    PubMed

    Fu, Jianwei; Xin, Qianqian; Wu, Xuechen; Chen, Zhonghui; Yan, Ya; Liu, Shujun; Wang, Minghuan; Xu, Qun

    2016-01-01

    Polydopamine (PDA) microspheres, synthesized by a facile oxidation polymerization route, were evaluated as a potential adsorbent for selective adsorption and separation of organic dyes. The adsorption processes towards nine water-soluble dyes (anionic dyes: methyl orange (MO), eosin-Y (EY), eosin-B (EB), acid chrome blue K (ACBK), neutral dye: neutral red (NR), and cationic dyes: rhodamine B (RhB), malachite green (MG), methylene blue (MB), safranine T (ST)) were thoroughly investigated. The adsorption selectivity of organic dyes onto PDA microspheres was successfully applied for the separation of dyes mixtures. Various influential factors such as solution pH, temperature, and contact time were employed to ascertain the optimal condition for adsorption of representative organic dyes including MB, MG and NR. The pseudo-first-order and pseudo-second-order kinetics models were used to fit the adsorption kinetics process. Five isothermal adsorption models (Langmuir, Dubnin-Radushkevich, Temkin, Freundlich and Harkins-Jura) were used to investigate the adsorption thermodynamics properties. The results showed that the PDA microspheres owned good selective adsorption ability towards cationic dyes. The adsorption kinetics process conformed to the pseudo-second-order kinetics model and the Langmuir isotherm model was more appropriate for tracing the adsorption behavior than other isotherm models. Thus, we can conclude PDA microspheres may be a high-efficiency selective adsorbent towards some cationic dyes.

  16. Selective adsorption and separation of organic dyes from aqueous solution on polydopamine microspheres.

    PubMed

    Fu, Jianwei; Xin, Qianqian; Wu, Xuechen; Chen, Zhonghui; Yan, Ya; Liu, Shujun; Wang, Minghuan; Xu, Qun

    2016-01-01

    Polydopamine (PDA) microspheres, synthesized by a facile oxidation polymerization route, were evaluated as a potential adsorbent for selective adsorption and separation of organic dyes. The adsorption processes towards nine water-soluble dyes (anionic dyes: methyl orange (MO), eosin-Y (EY), eosin-B (EB), acid chrome blue K (ACBK), neutral dye: neutral red (NR), and cationic dyes: rhodamine B (RhB), malachite green (MG), methylene blue (MB), safranine T (ST)) were thoroughly investigated. The adsorption selectivity of organic dyes onto PDA microspheres was successfully applied for the separation of dyes mixtures. Various influential factors such as solution pH, temperature, and contact time were employed to ascertain the optimal condition for adsorption of representative organic dyes including MB, MG and NR. The pseudo-first-order and pseudo-second-order kinetics models were used to fit the adsorption kinetics process. Five isothermal adsorption models (Langmuir, Dubnin-Radushkevich, Temkin, Freundlich and Harkins-Jura) were used to investigate the adsorption thermodynamics properties. The results showed that the PDA microspheres owned good selective adsorption ability towards cationic dyes. The adsorption kinetics process conformed to the pseudo-second-order kinetics model and the Langmuir isotherm model was more appropriate for tracing the adsorption behavior than other isotherm models. Thus, we can conclude PDA microspheres may be a high-efficiency selective adsorbent towards some cationic dyes. PMID:26407057

  17. URANIUM EXTRACTION

    DOEpatents

    Harrington, C.D.; Opie, J.V.

    1958-07-01

    The recovery of uranium values from uranium ore such as pitchblende is described. The ore is first dissolved in nitric acid, and a water soluble nitrate is added as a salting out agent. The resulting feed solution is then contacted with diethyl ether, whereby the bulk of the uranyl nitrate and a portion of the impurities are taken up by the ether. This acid ether extract is then separated from the aqueous raffinate, and contacted with water causing back extractioa of the uranyl nitrate and impurities into the water to form a crude liquor. After separation from the ether extract, this crude liquor is heated to about 118 deg C to obtain molten uranyl nitrate hexahydratc. After being slightly cooled the uranyl nitrate hexahydrate is contacted with acid free diethyl ether whereby the bulk of the uranyl nitrate is dissolved into the ethcr to form a neutral ether solution while most of the impurities remain in the aqueous waste. After separation from the aqueous waste, the resultant ether solution is washed with about l0% of its volume of water to free it of any dissolved impurities and is then contacted with at least one half its volume of water whereby the uranyl nitrate is extracted into the water to form an aqueous product solution.

  18. Magnetic deep eutectic solvents molecularly imprinted polymers for the selective recognition and separation of protein.

    PubMed

    Liu, Yanjin; Wang, Yuzhi; Dai, Qingzhou; Zhou, Yigang

    2016-09-14

    A novel and facile magnetic deep eutectic solvents (DES) molecularly imprinted polymers (MIPs) for the selective recognition and separation of Bovine hemoglobin (BHb) was prepared. The new-type DES was adopted as the functional monomer which would bring molecular imprinted technology to a new direction. The amounts of DES were optimized. The obtained magnetic DES-MIPs were characterized with fourier transform infrared spectrometry (FT-IR), thermogravimetric analysis (TGA), field emission scanning electron microscope (FESEM), dynamic light scattering (DLS), elemental analysis and vibrating sample magnetometer (VSM). The results suggested that the imprinted polymers were successfully formed and possessed a charming magnetism. The maximum adsorption capability (Qmax) and dissociation constant (KL) were analyzed by Langmuir isotherms (R(2) = 0.9983) and the value were estimated to be 175.44 mg/g and 0.035 mg/mL for the imprinted particles. And the imprinted particles showed a high imprinting factor of 4.77. In addition, the magnetic DES-MIPs presented outstanding recognition specificity and selectivity so that it can be utilized to separate template protein from the mixture of proteins and real samples. Last but not least, the combination of deep eutectic solvents and molecular imprinted technology in this paper provides a new perspective for the recognition and separation of proteins. PMID:27566352

  19. Removal Characteristics of Immunoadsorption With the Immusorba TR-350 Column Using Conventional and Selective Plasma Separators.

    PubMed

    Ohkubo, Atsushi; Okado, Tomokazu; Miyamoto, Satoko; Goto, Keigo; Yamamoto, Motoki; Maeda, Takuma; Itagaki, Ayako; Seshima, Hiroshi; Kurashima, Naoki; Sohara, Eisei; Uchida, Shinichi; Rai, Tatemitsu

    2016-08-01

    In Japan, immunoadsorption (IA) is performed using a conventional plasma separator and Immusorba TR-350 column (TR-350) for the treatment of neurological immune diseases. By this method, TR-350 has the limited maximal capacity of the immunoglobulin G (IgG) adsorption, and fibrinogen (Fbg) is reduced remarkably. Evacure EC-4A10 (EC-4A) is a selective plasma separator and the sieving coefficients of IgG and Fbg using EC-4A were 0.5 and 0, respectively. Here, we investigated the removal characteristics of IgG and Fbg in IA by TR-350 using two different plasma membrane separators: conventional plasma separator (PE-IA) and EC-4A (EC-IA). In vitro filtration using plasma effluent was performed with a closed circuit. When the processed volume was 3 L, estimated removal amounts by PE-IA were 3172 mg for IgG and 3329 mg for Fbg, respectively. When the processed volume was 3 L, estimated removal amounts by EC-IA were 4946 mg and 1916 mg, respectively. EC-IA can be considered useful for the removal of IgG, including auto-antibodies, while retaining Fbg, thereby allowing even daily use. PMID:27523076

  20. Investigation of thermal treatment on selective separation of post consumer plastics prior to froth flotation

    SciTech Connect

    Guney, Ali; Poyraz, M. Ibrahim; Kangal, Olgac Burat, Firat

    2013-09-15

    Highlights: • Both PET and PVC have nearly the same densities. • The best pH value will be 4 for optimizing pH values. • Malic acid gave the best results for selective separation of PET and PVC. - Abstract: Plastics have become the widely used materials because of their advantages, such as cheapness, endurance, lightness, and hygiene. However, they cause waste and soil pollution and they do not easily decompose. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. Depending on their surface characteristics, these plastics can be separated from each other by flotation method which is useful mineral processing technique with its low cost and simplicity. The main objective of this study is to investigate the flotation characteristics of PET and PVC and determine the effect of plasticizer reagents on efficient plastic separation. For that purpose, various parameters such as pH, plasticizer concentration, plasticizer type, conditioning temperature and thermal conditioning were investigated. As a result, PET particles were floated with 95.1% purity and 65.3% efficiency while PVC particles were obtained with 98.1% purity and 65.3% efficiency.

  1. In-line assay monitor for uranium hexafluoride

    DOEpatents

    Wallace, Steven A.

    1981-01-01

    An in-line assay monitor for determining the content of uranium-235 in a uranium hexafluoride gas isotopic separation system is provided which removes the necessity of complete access to the operating parameters of the system for determining the uranium-235 content. The monitor is intended for uses such as safeguard applications to assure that weapons grade uranium is not being produced in an enrichment cascade. The method and monitor for carrying out the method involve cooling of a radiation pervious chamber connected in fluid communication with the selected point in the system to withdraw a specimen and solidify the specimen in the chamber. The specimen is irradiated by means of an ionizing radiation source of energy different from that of the 185 keV gamma emissions from the uranium-235 present in the specimen. Simultaneously, the gamma emissions from the uranium-235 of the specimen and the source emissions transmitted through the sample are counted and stored in a multiple channel analyzer. The uranium-235 content of the specimen is determined from the comparison of the accumulated 185 keV energy counts and the reference energy counts. The latter is used to measure the total uranium isotopic content of the specimen. The process eliminates the necessity of knowing the system operating conditions and yet obtains the necessary data without need for large scintillation crystals and sophisticated mechanical designs.

  2. Selective Separation and Determination of Heavy Metals (Cd, Pb, Cr) Speciation Forms from Hortic Antrosols

    NASA Astrophysics Data System (ADS)

    Bulgariu, D.; Bulgariu, L.

    2009-04-01

    The speciation, inter-phases distribution and biodisponibility of heavy metals in soils represent one of main problem of environmental geochemistry and agro-chemistry. This problem is very important in case of hortic antrosols (soils from glasshouses) for the elimination of agricultural products (fruits, vegetables) contamination with heavy metals. In soils from glass houses, the speciation and inter-phases distribution processes of heavy metals have a particular dynamic, different in comparison with those from non-protected soils. The predominant distribution forms of heavy metals in such soils types are: complexes with low mass organic molecules, organic-mineral complexes, complexes with inorganic ligands (hydroxide-complexes, carbonate-complexes, sulphate-complexes, etc.) and basic salts. All of these have high stabilities in conditions of soils from glass houses, and in consequence, the separation and determination of speciation forms (which is directly connected with biodisponibility of heavy metals) by usual methods id very difficult and has a high uncertain degree. In this study is presented an original method for the selective separation and differentiation of speciation forms of heavy metals from glass houses soils, which is based by the combination of solid-liquid sequential extraction (SPE) with the extraction in aqueous polymer-inorganic salt two-phase systems (ABS). The soil samples used for this study have been sampled from three different locations (glass houses from Iasi, Barlad and Bacau - Romania) where the vegetables cultivation have bee performed by three different technologies. In this way was estimated the applicability and the analytical limits of method proposed by as, in function of the chemical-mineralogical and physical-chemical characteristics of soils. As heavy metals have been studied cadmium, lead and chromium, all being known for their high toxicity. The procedure used for the selective separation and differentiation of speciation

  3. METHOD OF RECOVERING URANIUM COMPOUNDS

    DOEpatents

    Poirier, R.H.

    1957-10-29

    S>The recovery of uranium compounds which have been adsorbed on anion exchange resins is discussed. The uranium and thorium-containing residues from monazite processed by alkali hydroxide are separated from solution, and leached with an alkali metal carbonate solution, whereby the uranium and thorium hydrorides are dissolved. The carbonate solution is then passed over an anion exchange resin causing the uranium to be adsorbed while the thorium remains in solution. The uranium may be recovered by contacting the uranium-holding resin with an aqueous ammonium carbonate solution whereby the uranium values are eluted from the resin and then heating the eluate whereby carbon dioxide and ammonia are given off, the pH value of the solution is lowered, and the uranium is precipitated.

  4. Size-selective separation of DNA fragments by using lysine-functionalized silica particles

    NASA Astrophysics Data System (ADS)

    Liu, Lingling; Guo, Zilong; Huang, Zhenzhen; Zhuang, Jiaqi; Yang, Wensheng

    2016-02-01

    In this work, a facile and efficient approach has been demonstrated for size-selective separation of DNA fragments by using lysine-functionalized silica particles. At a given pH, the environmental ionic strength can be utilized to alter the electrostatic interactions of lysine-functionalized silica particles with DNA fragments and in turn the DNA fragments on the silica particle surfaces, which exhibits a clear dependence on the DNA fragment sizes. By carefully adjusting the environmental pH and salt concentration, therefore, the use of the lysine-functionalized silica particles allows effective separation of binary and ternary DNA mixtures, for example, two different DNA fragments with sizes of 101 and 1073 bp, 101 and 745 bp, 101 and 408 bp, respectively, and three different DNA fragments with sizes of 101, 408 and 1073 bp.

  5. Size-selective separation of DNA fragments by using lysine-functionalized silica particles

    PubMed Central

    Liu, Lingling; Guo, Zilong; Huang, Zhenzhen; Zhuang, Jiaqi; Yang, Wensheng

    2016-01-01

    In this work, a facile and efficient approach has been demonstrated for size-selective separation of DNA fragments by using lysine-functionalized silica particles. At a given pH, the environmental ionic strength can be utilized to alter the electrostatic interactions of lysine-functionalized silica particles with DNA fragments and in turn the DNA fragments on the silica particle surfaces, which exhibits a clear dependence on the DNA fragment sizes. By carefully adjusting the environmental pH and salt concentration, therefore, the use of the lysine-functionalized silica particles allows effective separation of binary and ternary DNA mixtures, for example, two different DNA fragments with sizes of 101 and 1073 bp, 101 and 745 bp, 101 and 408 bp, respectively, and three different DNA fragments with sizes of 101, 408 and 1073 bp. PMID:26911527

  6. Imprint-coating synthesis of selective functionalized ordered mesoporous sorbents for separation and sensors

    DOEpatents

    Dai, Sheng; Burleigh, Mark C.; Shin, Yongsoon

    2001-01-01

    The present invention relates generally to mesoporous sorbent materials having high capacity, high selectivity, fast kinetics, and molecular recognition capability. The invention also relates to a process for preparing these mesoporous substrates through molecular imprinting techniques which differ from convention techniques in that a template molecule is bound to one end of bifunctional ligands to form a complex prior to binding of the bifunctional ligands to the substrate. The present invention also relates to methods of using the mesoporous sorbent materials, for example, in the separation of toxic metals from process effluents, paints, and other samples; detection of target molecules, such as amino acids, drugs, herbicides, fertilizers, and TNT, in samples; separation and/or detection of substances using chromatography; imaging agents; sensors; coatings; and composites.

  7. Separating Metallic Beryllium from Plutonium by Selective Dissolution with Ammonium Fluoride

    SciTech Connect

    Torres, R A

    2006-11-29

    Plutonium metal is stabilized for long-term storage by calcining to produce PuO{sub 2}. However, if beryllium is present, the calcined product may have a high neutron dose rate because of the {sup 9}Be({alpha},n){sup 12}C reaction in the finely divided oxide mixture. (At LLNL, inadvertent calcining of a mixture of {approx}500 g Pu/50 g Be produced a neutron source of {approx}5 R/hr.) Therefore, for health physics reasons, we would like a convenient procedure to remove beryllium from plutonium with high selectivity. Two reagents, sodium hydroxide and ammonium fluoride, were considered for aqueous processing. Each reagent selectively dissolves beryllium, which can be separated from the insoluble plutonium by decanting/filtering operations followed by water washes to remove the excess reagent. The washed plutonium is calcined for storage; the beryllium and wash fractions are solidified for disposal.

  8. A recyclable supramolecular membrane for size-selective separation of nanoparticles.

    PubMed

    Krieg, Elisha; Weissman, Haim; Shirman, Elijah; Shimoni, Eyal; Rybtchinski, Boris

    2011-03-01

    Most practical materials are held together by covalent bonds, which are irreversible. Materials based on noncovalent interactions can undergo reversible self-assembly, which offers advantages in terms of fabrication, processing and recyclability, but the majority of noncovalent systems are too fragile to be competitive with covalent materials for practical applications, despite significant attempts to develop robust noncovalent arrays. Here, we report nanostructured supramolecular membranes prepared from fibrous assemblies in water. The membranes are robust due to strong hydrophobic interactions, allowing their application in the size-selective separation of both metal and semiconductor nanoparticles. A thin (12 µm) membrane is used for filtration (∼5 nm cutoff), and a thicker (45 µm) membrane allows for size-selective chromatography in the sub-5 nm domain. Unlike conventional membranes, our supramolecular membranes can be disassembled using organic solvent, cleaned, reassembled and reused multiple times.

  9. A recyclable supramolecular membrane for size-selective separation of nanoparticles

    NASA Astrophysics Data System (ADS)

    Krieg, Elisha; Weissman, Haim; Shirman, Elijah; Shimoni, Eyal; Rybtchinski, Boris

    2011-03-01

    Most practical materials are held together by covalent bonds, which are irreversible. Materials based on noncovalent interactions can undergo reversible self-assembly, which offers advantages in terms of fabrication, processing and recyclability, but the majority of noncovalent systems are too fragile to be competitive with covalent materials for practical applications, despite significant attempts to develop robust noncovalent arrays. Here, we report nanostructured supramolecular membranes prepared from fibrous assemblies in water. The membranes are robust due to strong hydrophobic interactions, allowing their application in the size-selective separation of both metal and semiconductor nanoparticles. A thin (12 µm) membrane is used for filtration (~5 nm cutoff), and a thicker (45 µm) membrane allows for size-selective chromatography in the sub-5 nm domain. Unlike conventional membranes, our supramolecular membranes can be disassembled using organic solvent, cleaned, reassembled and reused multiple times.

  10. Remedial action plan and site design for stabilization of the inactive uranium processing site at Naturita, Colorado. Remedial action selection report, Attachment 2, Geology report: Preliminary final

    SciTech Connect

    Not Available

    1993-08-01

    The uranium processing site near Naturita, Colorado, is one of 24 inactive uranium mill sites designated to be cleaned up by the US Department of Energy (DOE) under the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA), Public Law 95-604. Part of the UMTRCA requires that the US Nuclear Regulatory Commission (NRC) concur with the DOE`s remedial action plan (RAP) and certify that the remedial action conducted at the site complies with the standards promulgated by the US Environmental Protection Agency (EPA). Included in the RAP is this Remedial Action Selection Report (RAS), which serves two purposes. First, it describes the activities that are proposed by the DOE to accomplish remediation and long-term stabilization and control of the radioactive materials at the inactive uranium processing site near Naturita, Colorado. Second, this document and the rest of the RAP, upon concurrence and execution by the DOE, the state of Colorado, and the NRC, become Appendix B of the cooperative agreement between the DOE and the State of Colorado.

  11. Remedial Action Plan and site design for stabilization of the inactive uranium mill tailings site at Durango, Colorado: Remedial action selection report. Revised final report

    SciTech Connect

    Not Available

    1991-12-01

    The uranium mill tailings site near Durango, Colorado, was one of 24 inactive uranium mill sites designated to be remediated by the US Department of Energy (DOE) under the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA). Part of the UMTRCA requires that the US Nuclear Regulatory Commission (NRC) concur with the DOE`s Remedial Action Plan (RAP) and certify that the remedial action conducted at the site complies with the standards promulgated by the US Environmental Protection Agency (EPA). Included in the RAP is this Remedial Action Selection Report (RAS), which has been developed to serve a two-fold purpose. First, it describes the activities that have been conducted by the DOE to accomplish remediation and long-term stabilization and control of the radioactive materials at the inactive uranium mill processing site near Durango, Colorado. Secondly, this document and the rest of the RAP, upon concurrence and execution by the DOE, the State of Colorado, and the NRC, become Appendix B of the Cooperative Agreement between the DOE and the State of Colorado.

  12. Remedial Action Plan and site design for stabilization of the inactive uranium mill tailings site at Durango, Colorado: Remedial action selection report

    SciTech Connect

    Not Available

    1991-12-01

    The uranium mill tailings site near Durango, Colorado, was one of 24 inactive uranium mill sites designated to be remediated by the US Department of Energy (DOE) under the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA). Part of the UMTRCA requires that the US Nuclear Regulatory Commission (NRC) concur with the DOE's Remedial Action Plan (RAP) and certify that the remedial action conducted at the site complies with the standards promulgated by the US Environmental Protection Agency (EPA). Included in the RAP is this Remedial Action Selection Report (RAS), which has been developed to serve a two-fold purpose. First, it describes the activities that have been conducted by the DOE to accomplish remediation and long-term stabilization and control of the radioactive materials at the inactive uranium mill processing site near Durango, Colorado. Secondly, this document and the rest of the RAP, upon concurrence and execution by the DOE, the State of Colorado, and the NRC, become Appendix B of the Cooperative Agreement between the DOE and the State of Colorado.

  13. Selecting a separable parametric spatiotemporal covariance structure for longitudinal imaging data.

    PubMed

    George, Brandon; Aban, Inmaculada

    2015-01-15

    Longitudinal imaging studies allow great insight into how the structure and function of a subject's internal anatomy changes over time. Unfortunately, the analysis of longitudinal imaging data is complicated by inherent spatial and temporal correlation: the temporal from the repeated measures and the spatial from the outcomes of interest being observed at multiple points in a patient's body. We propose the use of a linear model with a separable parametric spatiotemporal error structure for the analysis of repeated imaging data. The model makes use of spatial (exponential, spherical, and Matérn) and temporal (compound symmetric, autoregressive-1, Toeplitz, and unstructured) parametric correlation functions. A simulation study, inspired by a longitudinal cardiac imaging study on mitral regurgitation patients, compared different information criteria for selecting a particular separable parametric spatiotemporal correlation structure as well as the effects on types I and II error rates for inference on fixed effects when the specified model is incorrect. Information criteria were found to be highly accurate at choosing between separable parametric spatiotemporal correlation structures. Misspecification of the covariance structure was found to have the ability to inflate the type I error or have an overly conservative test size, which corresponded to decreased power. An example with clinical data is given illustrating how the covariance structure procedure can be performed in practice, as well as how covariance structure choice can change inferences about fixed effects.

  14. Selecting a Separable Parametric Spatiotemporal Covariance Structure for Longitudinal Imaging Data

    PubMed Central

    George, Brandon; Aban, Inmaculada

    2014-01-01

    Longitudinal imaging studies allow great insight into how the structure and function of a subject’s internal anatomy changes over time. Unfortunately, the analysis of longitudinal imaging data is complicated by inherent spatial and temporal correlation: the temporal from the repeated measures, and the spatial from the outcomes of interest being observed at multiple points in a patients body. We propose the use of a linear model with a separable parametric spatiotemporal error structure for the analysis of repeated imaging data. The model makes use of spatial (exponential, spherical, and Matérn) and temporal (compound symmetric, autoregressive-1, Toeplitz, and unstructured) parametric correlation functions. A simulation study, inspired by a longitudinal cardiac imaging study on mitral regurgitation patients, compared different information criteria for selecting a particular separable parametric spatiotemporal correlation structure as well as the effects on Type I and II error rates for inference on fixed effects when the specified model is incorrect. Information criteria were found to be highly accurate at choosing between separable parametric spatiotemporal correlation structures. Misspecification of the covariance structure was found to have the ability to inflate the Type I error or have an overly conservative test size, which corresponded to decreased power. An example with clinical data is given illustrating how the covariance structure procedure can be done in practice, as well as how covariance structure choice can change inferences about fixed effects. PMID:25293361

  15. Highly selective separation of enantiomers using a chiral porous organic cage.

    PubMed

    Zhang, Jun-Hui; Xie, Sheng-Ming; Wang, Bang-Jin; He, Pin-Gang; Yuan, Li-Ming

    2015-12-24

    Porous solids composed of shape-persistent organic cage molecules have attracted considerable attention due to their important applications such as molecular separation, heterogeneous catalysis, and gas storage. In this study, an imine-linked porous organic cage (POC) CC10 diluted with a polysiloxane OV-1701 was explored as a novel stationary phase for high-resolution gas chromatography (GC). A wide variety of enantiomers belonging to different classes of organic compounds have been resolved on the coated capillary column, including chiral alcohols, esters, ketones, ethers, halohydrocarbons, epoxides, and organic acids. The fabricated column complements to commercial β-DEX 120 column and our recently reported CC3-R column for separating enantiomers, which indicates that the excellent chiral recognition ability of CC10 is not only interesting academically, but also has potential for practical application. In addition, CC10 also exhibits good selectivity for the separation of n-alkanes, n-alcohols, Grob mixture, and positional isomers. This work also indicates that this type of chiral POCs will become a new class of chiral selector in the near future. PMID:26632517

  16. Approach for selective separation of thiophenic and sulfidic sulfur compounds from petroleum by methylation/demethylation.

    PubMed

    Wang, Meng; Zhao, Suoqi; Chung, Keng H; Xu, Chunming; Shi, Quan

    2015-01-20

    Detailed characterization of petroleum derived sulfur compounds has been challenging, due to the complex composition of the hydrocarbon matrix. A novel method was developed for selective separation of thiophenic and sulfidic compounds from petroleum. Sulfur compounds were methylated to sulfonium salts by AgBF4 and CH3I, then the polar salts were separated by precipitation from petroleum matrix. The thiophenic and sulfidic sulfonium salts were sequentially demethylated with 7-azaindole and 4-dimethylaminopyridine, obtaining original thiophenic and sulfidic compounds, respectively. The method was validated by model compounds, and applied to a diesel and a vacuum distillation petroleum fraction. Sulfur fractions were characterized by gas chromatography (GC) coupled with a sulfur chemiluminescence detector (SCD) and quadrupole mass spectrometry (MS), and high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The technique was effective to selectively obtain high-purity thiophenic and sulfidic compounds and showed rare discrimination among sulfur compounds with ranging molecular weights and degrees of unsaturation. The method would facilitate multifaceted detailed characterization of sulfur compounds in an organic complex matrix. PMID:25519193

  17. Atomic vapor laser isotope separation

    SciTech Connect

    Stern, R.C.; Paisner, J.A.

    1985-11-08

    Atomic vapor laser isotope separation (AVLIS) is a general and powerful technique. A major present application to the enrichment of uranium for light-water power reactor fuel has been under development for over 10 years. In June 1985 the Department of Energy announced the selection of AVLIS as the technology to meet the nation's future need for the internationally competitive production of uranium separative work. The economic basis for this decision is considered, with an indicated of the constraints placed on the process figures of merit and the process laser system. We then trace an atom through a generic AVLIS separator and give examples of the physical steps encountered, the models used to describe the process physics, the fundamental parameters involved, and the role of diagnostic laser measurements.

  18. [Hyperspectral Band Selection Based on Spectral Clustering and Inter-Class Separability Factor].

    PubMed

    Qin, Fang-pu; Zhang, Ai-wu; Wang, Shu-min; Meng, Xian-gang; Hu, Shao-xing; Sun, Wei-dong

    2015-05-01

    With the development of remote sensing technology and imaging spectrometer, the resolution of hyperspectral remote sensing image has been continually improved, its vast amount of data not only improves the ability of the remote sensing detection but also brings great difficulties for analyzing and processing at the same time. Band selection of hyperspectral imagery can effectively reduce data redundancy and improve classification accuracy and efficiency. So how to select the optimum band combination from hundreds of bands of hyperspectral images is a key issue. In order to solve these problems, we use spectral clustering algorithm based on graph theory. Firstly, taking of the original hyperspectral image bands as data points to be clustered , mutual information between every two bands is calculated to generate the similarity matrix. Then according to the graph partition theory, spectral decomposition of the non-normalized Laplacian matrix generated by the similarity matrix is used to get the clusters, which the similarity between is small and the similarity within is large. In order to achieve the purpose of dimensionality reduction, the inter-class separability factor of feature types on each band is calculated, which is as the reference index to choose the representative bands in the clusters furthermore. Finally, the support vector machine and minimum distance classification methods are employed to classify the hyperspectral image after band selection. The method in this paper is different from the traditional unsupervised clustering method, we employ spectral clustering algorithm based on graph theory and compute the interclass separability factor based on a priori knowledge to select bands. Comparing with traditional adaptive band selection algorithm and band index based on automatically subspace divided algorithm, the two sets of experiments results show that the overall accuracy of SVM is about 94. 08% and 94. 24% and the overall accuracy of MDC is about 87

  19. Evaluation of selected detector systems for products formed in the atmospheric hydrolysis of uranium hexafluoride

    SciTech Connect

    Bostick, W.D.; Bostick, D.T.

    1987-03-01

    Sensitive detection of UF/sub 6/ hydrolysis products, either by discontinuous sampling or by continuous or near real-time monitoring, is an important safety consideration for DOE contractors handling large quantities of UF/sub 6/. Automated continuous or rapid intermittent remote sensing of these reaction products can provide an alarm signal when a preselected threshold value has been exceeded (absolute response) or when a significant emission excursion has occurred (rate of change of response). This report evaluates the performance of selected devices for the detection of airborne materials formed in the release of liquid UF/sub 6/ (approx. =1.3 g) into an enclosed volume of 6 m/sup 3/; these experiments were initiated on October 23, 1986. The detection principles investigated are: photometric, gas detector tubes, and electrochemical sensor.

  20. Heterostructured magnetite-titanate nanosheets for prompt charge selective binding and magnetic separation of mixed proteins.

    PubMed

    Zhou, Qinhua; Lu, Zhufeng; Cao, Xuebo

    2014-02-01

    We reported the prompt charge selective binding and magnetic separation of mixed proteins by utilizing heterostructured Fe3O4-Na2Ti3O7 nanosheets. Fe3O4-Na2Ti3O7 nanosheets are found to combine a variety of structure and property merits, such as the increased interlayer galleries, exposed exchange sites, flexible framework, and magnetic manipulability. Probing the dissociation dynamics of Na(+) inside the nanosheets reveals that they possess remarkably enhanced Na(+) dissociation capability and the dissociation rate of Na(+) reaches 7.9×10(-)(6)mol g(-)(1)s(-)(1), much superior to titanate nanotubes. In model protein separation experiments, we utilize mixed proteins containing albumin and hemoglobin to assess Fe3O4-Na2Ti3O7 nanosheets. It is found that, by controlling the pH of the sample at 6, positively charged hemoglobin and negatively charged albumin are immediately separated (∼5s) by the nanosheets and the saturated loading capacity of hemoglobin on the nanosheets reaches 4.7±0.61g g(-)(1). Furthermore, hemoglobin bound to the nanosheets can be readily released after buffer wash and is not damaged, while the nanosheets are recyclable and maintain their high efficiency. The outstanding performance of Fe3O4-Na2Ti3O7 nanosheets in separating mixed proteins is attributed to the ultrafast Na(+) dissociation rate, flexible titanate framework, open geometry, and aqueous-like environment to stabilize proteins. These merits, together with the recyclability and cost effectiveness, should make Fe3O4-Na2Ti3O7 nanosheets ideal candidates for biological recognition, isolation, and purification under technologically useful conditions.

  1. SEPARATION PROCESS FOR THORIUM SALTS

    DOEpatents

    Bridger, G.L.; Whatley, M.E.; Shaw, K.G.

    1957-12-01

    A process is described for the separation of uranium, thorium, and rare earths extracted from monazite by digesting with sulfuric acid. By carefully increasing the pH of the solution, stepwise, over the range 0.8 to 5.5, a series of selective precipitations will be achieved, with the thorium values coming out at lower pH, the rare earths at intermediate pH and the uranium last. Some mixed precipitates will be obtained, and these may be treated by dissolving in HNO/sub 3/ and contacting with dibutyl phosphate, whereby thorium or uranium are taken up by the organic phase while the rare earths preferentially remain in the aqueous solution.

  2. Combination of solid phase extraction and dispersive liquid-liquid microextraction for separation/preconcentration of ultra trace amounts of uranium prior to its fiber optic-linear array spectrophotometry determination.

    PubMed

    Dadfarnia, Shayessteh; Shabani, Ali Mohammad Haji; Shakerian, Farid; Shiralian Esfahani, Golnaz

    2013-12-15

    A simple and sensitive method for the separation and preconcentration of the ultra trace amounts of uranium and its determination by spectrophotometry was developed. The method is based on the combination of solid phase extraction and dispersive liquid-liquid microextraction. Thus, by passing the sample through the basic alumina column, the uranyl ion and some cations are separated from the sample matrix. The retained uranyl ion along with the cations are eluted with 5 mL of nitric acid (2 mol L(-1)) and after neutralization of the eluent, the extracted uranyl ion is converted to its anionic benzoate complex and is separated from other cations by extraction of its ion pair with malachite green into small volume of chloroform using dispersive liquid-liquid microextraction. The amount of uranium is then determined by the absorption measurement of the extracted ion pair at 621 nm using flow injection spectrophotometry. Under the optimum conditions, with 500 mL of the sample, a preconcentration factor of 1980, a detection limit of 40 ng L(-1), and a relative standard deviation of 4.1% (n=6) at 400 ng L(-1) were obtained. The method was successfully applied to the determination of uranium in mineral water, river water, well water, spring water and sea water samples.

  3. Separate visual signals for saccade initiation during target selection in the primate superior colliculus.

    PubMed

    White, Brian J; Munoz, Douglas P

    2011-02-01

    The primary function of the superior colliculus (SC) is to orient the visual system toward behaviorally relevant stimuli defined by features such as color. However, a longstanding view has held that visual activity in the SC arises exclusively from achromatic pathways. Recently, we reported evidence that the primate SC is highly sensitive to signals originating from chromatic pathways, but these signals are delayed relative to luminance signals (White et al., 2009). Here, we describe a functional consequence of this difference in visual arrival time on the processes leading to target selection and saccade initiation. Two rhesus monkeys performed a simple color-singleton selection task in which stimuli carried a chromatic component only (target and distractors were isoluminant with the background, but differed in chromaticity) or a combined chromatic-achromatic component (36% luminance contrast added equally to all stimuli). Although visual responses were delayed in the chromatic-only relative to the combined chromatic-achromatic condition, SC neurons discriminated the target from distractors at approximately the same time provided stimulus chromaticity was held constant. However, saccades were triggered sooner, and with more errors, with the chromatic-achromatic condition, suggesting that luminance signals associated with these stimuli increased the probability of triggering a saccade before the target color was adequately discriminated. These results suggest that separate mechanisms may independently influence the saccadic command in the SC, one linked to the arrival time of pertinent visual signals, and another linked to the output of the visual selection process. PMID:21289164

  4. Size-selective separation of macromolecules by nanochannel titania membrane with self-cleaning (declogging) ability.

    PubMed

    Roy, Poulomi; Dey, Tuli; Lee, Kiyoung; Kim, Doohun; Fabry, Ben; Schmuki, Patrik

    2010-06-16

    We report on a simple and self-organizing process for the fabrication of TiO(2) nanochannel membranes with a channel width of 8-10 nm that can be used for size selective separation of macromolecules (proteins). The membrane, consisting of self-aligned oxide channels, is formed by complete anodization of a thin Ti foil under specific electrochemical conditions in a glycerol-phosphate electrolyte. Due to self-cleaning properties of TiO(2), clogged membranes (for example due to extended use) can easily be fully reopened and thus are reusable. As the TiO(2) after anodic formation directly contains anatase crystallites (the most photoactive TiO(2) crystal form) no thermal treatment of the membrane is required (avoiding the danger of thermally induced cracking).

  5. Metal-organic and zeolite imidazolate frameworks (MOFs and ZIFs) for highly selective separations

    SciTech Connect

    Yaghi, Omar M

    2012-09-17

    Metal-organic and zeolite imidazolate frameworks (MOFs and ZIFs) have been investigated for the realization as separation media with high selectivity. These structures are held together with strong bonds, making them architecturally, chemically, and thermally stable. Therefore, employing well designed building units, it is possible to discover promising materials for gas and vapor separation. This grant was focused on the study of MOFs and ZIFs with these specific objectives: (i) to develop a strategy for producing MOFs and ZIFs that combine high surface areas with active sites for their use in gas adsorption and separation of small organic compounds, (ii) to introduce active sites in the framework by a post-synthetic modification and metalation of MOFs and ZIFs, and (iii) to design and synthesize MOFs with extremely high surface areas and large pore volumes to accommodate large amounts of guest molecules. By the systematic study, this effort demonstrated how to introduce active functional groups in the frameworks, and this is also the origin of a new strategy, which is termed isoreticular functionalization and metalation. However, a large pore volume is still a prerequisite feature. One of the solutions to overcome this challenge is an isoreticular expansion of a MOF's structure. With triangular organic linker and square building units, we demonstrated that MOF-399 has a unit cell volume 17 times larger than that of the first reported material isoreticular to it, and it has the highest porosity (94%) and lowest density (0.126 g cm-3) of any MOF reported to date. MOFs are not just low density materials; the guest-free form of MOF-210 demonstrates an ultrahigh porosity, whose BET surface area was estimated to be 6240 m2 g-1 by N2 adsorption measurements.

  6. URANIUM PRECIPITATION PROCESS

    DOEpatents

    Thunaes, A.; Brown, E.A.; Smith, H.W.; Simard, R.

    1957-12-01

    A method for the recovery of uranium from sulfuric acid solutions is described. In the present process, sulfuric acid is added to the uranium bearing solution to bring the pH to between 1 and 1.8, preferably to about 1.4, and aluminum metal is then used as a reducing agent to convert hexavalent uranium to the tetravalent state. As the reaction proceeds, the pH rises amd a selective precipitation of uranium occurs resulting in a high grade precipitate. This process is an improvement over the process using metallic iron, in that metallic aluminum reacts less readily than metallic iron with sulfuric acid, thus avoiding consumption of the reducing agent and a raising of the pH without accomplishing the desired reduction of the hexavalent uranium in the solution. Another disadvantage to the use of iron is that positive ferric ions will precipitate with negative phosphate and arsenate ions at the pH range employed.

  7. DNA aptamers for selective identification and separation of flame retardant chemicals.

    PubMed

    Kim, Un-Jung; Kim, Byoung Chan

    2016-09-14

    Polybrominated diphenyl ethers (PBDEs) are group of chemicals which are representative persistent organic pollutants (POPs) and used as brominated flame retardants for many consumer products. PBDEs were phased out since 2009 but are still frequently observed in various environmental matrices and human body. Here, we report ssDNA aptamers which bind to BDE47, one of the PBDE congeners commonly found in various environmental matrices, and show affinity to other major tri-to hepta- BDE congeners. The PBDE specific aptamers were isolated from random library of ssDNA using Mag-SELEX. Two out of 15 sequences, based on their alignment and hairpin loop structures, were chosen to determine dissociation constant with BDE47 and showed from picomolar to nanomolar affinities (200 pM and 1.53 nM). The aptamers displayed high selectivity to the original target, BDE47, and implying general specificity to PBDE backbone with varying affinities to other congeners. Further, we showed that the use of two aptamers together could enhance the separation efficiency of BDE47 and other BDE congeners when dissolved in a solvent compared to use of single aptamer. These aptamers are expected to provide a tool for preliminary screening or quick separation of PBDEs in environmental samples prior to trace quantitative analysis.

  8. Ultrathin pH-sensitive nanoporous membranes for superfast size-selective separation.

    PubMed

    Zhang, Qiu Gen; Deng, Chao; Liu, Rong Rong; Lin, Zhen; Li, Hong Mei; Zhu, Ai Mei; Liu, Qing Lin

    2015-05-01

    Stimuli-responsive nanoporous membranes have attracted increasing interest in various fields due to their abrupt changes of permeation/separation in response to the external environment. Here we report ultrathin pH-sensitive nanoporous membranes that are easily fabricated by the self-assembly of poly(acrylic acid) (PAA) in a metal hydroxide nanostrand solution. PAA-adsorbed nanostrands (2.5-5.0 nm) and PAA-Cu(II) nanogels (2.0-2.5 nm) grow competitively during self-assembly. The PAA-adsorbed nanostrands are deposited on a porous support to fabricate ultrathin PAA membranes. The membranes display ultrafast water permeation and good rejection as well as significant pH-sensitivity. The 28 nm-thick membrane has a water flux decrease from 3740 to 1350 L m(-1)  h(-1)  bar(-1) (pH 2.0 to 7.0) with a sharp decrease at pH 5.0. This newly developed pH-sensitive nanoporous membranes may find a wide range of applications such as controlled release and size- and charge-selective separation. PMID:25736206

  9. DNA aptamers for selective identification and separation of flame retardant chemicals.

    PubMed

    Kim, Un-Jung; Kim, Byoung Chan

    2016-09-14

    Polybrominated diphenyl ethers (PBDEs) are group of chemicals which are representative persistent organic pollutants (POPs) and used as brominated flame retardants for many consumer products. PBDEs were phased out since 2009 but are still frequently observed in various environmental matrices and human body. Here, we report ssDNA aptamers which bind to BDE47, one of the PBDE congeners commonly found in various environmental matrices, and show affinity to other major tri-to hepta- BDE congeners. The PBDE specific aptamers were isolated from random library of ssDNA using Mag-SELEX. Two out of 15 sequences, based on their alignment and hairpin loop structures, were chosen to determine dissociation constant with BDE47 and showed from picomolar to nanomolar affinities (200 pM and 1.53 nM). The aptamers displayed high selectivity to the original target, BDE47, and implying general specificity to PBDE backbone with varying affinities to other congeners. Further, we showed that the use of two aptamers together could enhance the separation efficiency of BDE47 and other BDE congeners when dissolved in a solvent compared to use of single aptamer. These aptamers are expected to provide a tool for preliminary screening or quick separation of PBDEs in environmental samples prior to trace quantitative analysis. PMID:27566357

  10. Gel electrophoresis using a selective radical for the separation of single-walled carbon nanotubes.

    PubMed

    Mesgari, Sara; Sundramoorthy, Ashok Kumar; Loo, Leslie S; Chan-Park, Mary B

    2014-01-01

    We have applied agarose gel electrophoresis (AGE) to single-walled carbon nanotubes (SWNTs) that have been pre-reacted with metallic-selective ionic radicals and then re-suspended with sodium cholate (SC) surfactant to obtain highly purified (up to 98%) semiconducting single-walled carbon nanotubes (s-SWNTs). The proposed combination method exploits the preferential reactivity with the metallic nanotube of the radicals generated from an azo naphthalene compound (Direct Blue 71(I)) to preferentially increase the surface charge, and therefore the electrophoretic mobilities, of the metallic nanotube population under the influence of the electric field in AGE. The excellent separation achieved was verified by UV-vis-NIR and Raman spectroscopy as well as by the performance of field effect transistors fabricated with semiconducting-enriched SWNTs. FETs fabricated with -assisted AGE-separated semiconducting nanotubes exhibited mobilities of ∼3.6 to 11.7 cm(2) V(-1) s(-1) and on/off ratios from 10(2) to 10(6). PMID:25319125

  11. Highly Preorganized Ligand 1,10-Phenanthroline-2,9-dicarboxylic Acid for the Selective Recovery of Uranium from Seawater in the Presence of Competing Vanadium Species

    DOE PAGES

    Lashley, Mark A.; Ivanov, Alexander S.; Bryantsev, Vyacheslav S.; Dai, Sheng; Hancock, Robert D.

    2016-09-30

    Studies of the complexation of new promising ligands with uranyl (UO22+) and other seawater cations can aid the development of more efficient, selective, and robust sorbents for the recovery of uranium from seawater. Here, we propose that the ligand design principles based on structural preorganization can be successfully applied to obtain a dramatic enhancement in UO22+ ion binding affinity and selectivity. This concept is exemplified through the investigation of the com-plexes of UO22+, VO2+, and VO2+ with the highly preorganized ligand PDA (1,10-phenanthroline-2,9-dicarboxylic acid) using a combination of fluores-cence and absorbance techniques, along with den-sity functional theory (DFT) calculations. Moreover,more » the measured stability constant value, log K1, of 16.5 for the UO22+/PDA complex is very high compared to uranyl complexes with other dicarboxylic ligands. Moreover, PDA exhibits strong selectivity for uranyl over vanadium ions, since the determined sta-bility constant values of the PDA complexes of the vanadium ions are quite low (V(IV) log K1 = 7.4, V(V) = 7.3). Finally, the structures of the corresponding UO22+, VO2+, and VO2+ complexes with PDA were identified by systematic DFT calculations, and helped to interpret the stronger binding affinity for uranium over the vanadium ions. Due to its high chemical stability, selectivity, and structural preor-ganization for UO22+ complexation, PDA is a very promising candidate that can be potentially used in the development of novel adsorbent materials for the selective extraction of uranium from sea-water.« less

  12. Method and apparatus for the selective separation of gaseous coal gasification products by pressure swing adsorption

    DOEpatents

    Ghate, Madhav R.; Yang, Ralph T.

    1987-01-01

    Bulk separation of the gaseous components of multi-component gases provided by the gasification of coal including hydrogen, carbon monoxide, methane, and acid gases (carbon dioxide plus hydrogen sulfide) are selectively adsorbed by a pressure swing adsorption technique using activated carbon, zeolite or a combination thereof as the adsorbent. By charging a column containing the adsorbent with a gas mixture and pressurizing the column to a pressure sufficient to cause the adsorption of the gases and then reducing the partial pressure of the contents of the column, the gases are selectively and sequentially desorbed. Hydrogen, the least absorbable gas of the gaseous mixture, is the first gas to be desorbed and is removed from the column in a co-current direction followed by the carbon monoxide, hydrogen and methane. With the pressure in the column reduced to about atmospheric pressure the column is evacuated in a countercurrent direction to remove the acid gases from the column. The present invention is particularly advantageous as a producer of high parity hydrogen from gaseous products of coal gasification and as an acid gas scrubber.

  13. Method and apparatus for the selective separation of gaseous coal gasification products by pressure swing adsorption

    DOEpatents

    Ghate, M.R.; Yang, R.T.

    1985-10-03

    Bulk separation of the gaseous components of multi-component gases provided by the gasification of coal including hydrogen, carbon monoxide, methane, and acid gases (carbon dioxide plus hydrogen sulfide) are selectively adsorbed by a pressure swing adsorption technique using activated carbon zeolite or a combination thereof as the adsorbent. By charging a column containing the adsorbent with a gas mixture and pressurizing the column to a pressure sufficient to cause the adsorption of the gases and then reducing the partial pressure of the contents of the column, the gases are selectively and sequentially desorbed. Hydrogen, the least absorbable gas of the gaseous mixture, is the first gas to be desorbed and is removed from the column in a co-current direction followed by the carbon monoxide, hydrogen and methane. With the pressure in the column reduced to about atmospheric pressure the column is evacuated in a countercurrent direction to remove the acid gases from the column. The present invention is particularly advantageous as a producer of high purity hydrogen from gaseous products of coal gasification and as an acid gas scrubber. 2 figs., 2 tabs.

  14. Affinity Selection of Peptide Binders with Magnetic Beads via Organic Phase Separation (MOPS).

    PubMed

    Murai, Ryuichi; Nogi, Taiki; Tateoka, Komei; Sato, Atsushi

    2015-01-01

    We describe a new method for affinity selection of peptide binders for soluble protein targets using magnetic beads via organic phase separation (MOPS) from a phage display library. As a model target molecule, a mouse monoclonal antibody against human integrin α9β1 (Y9A2) immobilized onto protein G magnetic beads was incubated with a 15-mer or 20-mer random peptide phage-display library. The suspensions containing the phage-magnetic beads conjugates were then transferred onto the organic phase and centrifuged in order to recover the Y9A2 bound phage immobilized on the protein G magnetic beads in the lower organic phase. After three rounds of biopanning, we were able to isolate specific phage clones that could not be obtained by the conventional approach. Furthermore, this new approach was found to be highly effective for isolating phage-binders for Fc-fusion constructs; indeed, enrichment of specific phage-binders was observed after only the first panning cycle. Thus, MOPS can improve the selection of specific phage-binders for soluble protein targets mainly due to the removal of non-specific binders.

  15. Selectivity differences of water-soluble vitamins separated on hydrophilic interaction stationary phases.

    PubMed

    Yang, Yuanzhong; Boysen, Reinhard I; Hearn, Milton T W

    2013-06-01

    In this study, the retention behavior and selectivity differences of water-soluble vitamins were evaluated with three types of polar stationary phases (i.e. an underivatized silica phase, an amide phase, and an amino phase) operated in the hydrophilic interaction chromatographic mode with ESI mass spectrometric detection. The effects of mobile phase composition, including buffer pH and concentration, on the retention and selectivity of the vitamins were investigated. In all stationary phases, the neutral or weakly charged vitamins exhibited very weak retention under each of the pH conditions, while the acidic and more basic vitamins showed diverse retention behaviors. With the underivatized silica phase, increasing the salt concentration of the mobile phase resulted in enhanced retention of the acidic vitamins, but decreased retention of the basic vitamins. These observations thus signify the involvement of secondary mechanisms, such as electrostatic interaction in the retention of these analytes. Under optimized conditions, a baseline separation of all vitamins was achieved with excellent peak efficiency. In addition, the effects of water content in the sample on retention and peak efficiency were examined, with sample stacking effects observed when the injected sample contained a high amount of water.

  16. Separable Sustained and Selective Attention Factors Are Apparent in 5-Year-Old Children

    PubMed Central

    Underbjerg, Mette; George, Melanie S.; Thorsen, Poul; Kesmodel, Ulrik S.; Mortensen, Erik L.; Manly, Tom

    2013-01-01

    In adults and older children, evidence consistent with relative separation between selective and sustained attention, superimposed upon generally positive inter-test correlations, has been reported. Here we examine whether this pattern is detectable in 5-year-old children from the healthy population. A new test battery (TEA-ChJ) was adapted from measures previously used with adults and older children and administered to 172 5-year-olds. Test-retest reliability was assessed in 60 children. Ninety-eight percent of the children managed to complete all measures. Discrimination of visual and auditory stimuli were good. In a factor analysis, the two TEA-ChJ selective attention tasks (one visual, one auditory) loaded onto a common factor and diverged from the two sustained attention tasks (one auditory, one motor), which shared a common loading on the second factor. This pattern, which suggests that the tests are indeed sensitive to underlying attentional capacities, was supported by the relationships between the TEA-ChJ factors and Test of Everyday Attention for Children subtests in the older children in the sample. It is possible to gain convincing performance-based estimates of attention at the age of 5 with the results reflecting a similar factor structure to that obtained in older children and adults. The results are discussed in light of contemporary models of attention function. Given the potential advantages of early intervention for attention difficulties, the findings are of clinical as well as theoretical interest. PMID:24376591

  17. Partition Coefficients of Selected Compounds Using Ion Exchange Separation of Cesium From High Level Waste

    SciTech Connect

    Toth, James J.; Blanchard, David L.; Arm, Stuart T.; Urie, Michael W.

    2004-04-24

    The removal of cesium radioisotope (137Cs) from the High Level Waste stored in underground storage tanks at the Hanford site is a formidable chemical separations challenge for the Waste Treatment Plant. An eluatable organic-based ion exchange resin was selected as the baseline technology (1). The baseline technology design employs a proprietary macrocyclic weak-acid ion exchange resin to adsorb the cesium (137Cs) during the process loading cycle in a fixed bed column design. Following loading, the cesium is eluted from the resin using a nitric acid eluant. Previous work provided limited understanding of the performance of the resin, processed with actual wastes, and under multiple load and elute conditions, which are required for the ion exchange technology to be underpinned sufficiently for resolution of all process-related design issues before flowsheet and construction drawings can be released. By performing multiple ion exchange column tests with waste feeds, and measuring the chemical and radionuclide compositions of the waste feeds, column effluents and column eluants, ion exchange stream composition information can be provided for supporting resolution of selected design issues.

  18. Assessing ligand selectivity for uranium over vanadium ions to aid in the discovery of superior adsorbents for extraction of UO2(2+) from seawater.

    PubMed

    Ivanov, Alexander S; Bryantsev, Vyacheslav S

    2016-06-28

    Uranium is used as the basic fuel for nuclear power plants, which generate significant amounts of electricity and have life cycle carbon emissions that are as low as renewable energy sources. However, the extraction of this valuable energy commodity from the ground remains controversial, mainly because of environmental and health impacts. Alternatively, seawater offers an enormous uranium resource that may be tapped at minimal environmental cost. Nowadays, amidoxime polymers are the most widely utilized sorbent materials for large-scale extraction of uranium from seawater, but they are not perfectly selective for uranyl, UO2(2+). In particular, the competition between UO2(2+) and VO(2+)/VO2(+) cations poses a significant challenge to the efficient mining of UO2(2+). Thus, screening and rational design of more selective ligands must be accomplished. One of the key components in achieving this goal is the establishment of computational techniques capable of assessing ligand selectivity trends. Here, we report an approach based on quantum chemical calculations that achieves high accuracy in reproducing experimental aqueous stability constants for VO(2+)/VO2(+) complexes with ten different oxygen donor ligands. The predictive power of the developed computational protocol is demonstrated for amidoxime-type ligands, providing greater insights into new design strategies for the development of the next generation of adsorbents with high selectivity toward UO2(2+) over VO(2+)/VO2(+) ions. Importantly, the results of calculations suggest that alkylation of amidoxime moieties present in poly(acrylamidoxime) sorbents can be a potential route to better discrimination between the uranyl and competing vanadium ions in seawater. PMID:27285397

  19. PROCESS OF RECOVERING URANIUM

    DOEpatents

    Kilner, S.B.

    1959-12-29

    A method is presented for separating and recovering uranium from a complex mixure of impurities. The uranium is dissolved to produce an aqueous acidic solution including various impurities. In accordance with one method, with the uranium in the uranyl state, hydrogen cyanide is introduced into the solution to complex the impurities. Subsequently, ammonia is added to the solution to precipitate the uraniunn as ammonium diuranate away from the impurities in the solution. Alternatively, the uranium is precipitated by adding an alkaline metal hydroxide. In accordance with the second method, the uranium is reduced to the uranous state in the solution. The reduced solution is then treated with solid alkali metal cyanide sufficient to render the solution about 0.1 to 1.0 N in cyanide ions whereat cyanide complex ions of the metal impurities are produced and the uranium is simultaneously precipituted as uranous hydroxide. Alternatively, hydrogen cyanide may be added to the reduced solution and the uranium precipitated subsequently by adding ammonium hydroxide or an alkali metal hydroxide. Other refinements of the method are also disclosed.

  20. Recovery of uranium values

    DOEpatents

    Brown, K. B.; Crouse, Jr., D. J.; Moore, J. G.

    1959-03-10

    A liquid-liquid extraction method is presented for recovering uranium values from an aqueous acidic solution by means of certain high molecular weight amine fn the amine classes of primary, secondary, heterocyclic secondary, tertiary, or heterocyclic tertiary. The uranium bearing aqueous acidic solution is contacted with the selected anine dissolved in a nonpolar waterimmiscible organfc solvent such as kerosene. The uranium which is substantially completely extracted by the organic phase may be stripped therefrom by water, and recovered from the aqueous phase by treatment into ammonia to precipitate ammonium diuranate.

  1. RECOVERY OF URANIUM VALUES

    DOEpatents

    Brown, K.B.; Crouse, D.J. Jr.; Moore, J.G.

    1959-03-10

    A liquid-liquid extraction method is presented for recovering uranium values from an aqueous acidic solution by means of certain high molecular weight amine in the amine classes of primary, secondary, heterocyclic secondary, tertiary, or heterocyclic tertiary. The uranium bearing aqueous acidic solution is contacted with the selected amine dissolved in a nonpolar water-immiscible organic solvent such as kerosene. The uranium which is substantially completely exiracted by the organic phase may be stripped therefrom by waters and recovered from the aqueous phase by treatment into ammonia to precipitate ammonium diuranate.

  2. Separation of Californium from other Actinides

    DOEpatents

    Mailen, J C; Ferris, L M

    1973-09-25

    A method is provided for separating californium from a fused fluoride composition containing californium and at least one element selected from the group consisting of plutonium, americium, curium, uranium, thorium, and protactinium which comprises contacting said fluoride composition with a liquid bismuth phase containing sufficient lithium or thorium to effect transfer of said actinides to the bismuth phase and then contacting the liquid bismuth phase with molten LiCl to effect selective transfer of californium to the chloride phase.

  3. Selective liquid chromatographic separation of yttrium from heavier rare earth elements using acetic acid as a novel eluent.

    PubMed

    Kifle, Dejene; Wibetoe, Grethe

    2013-09-13

    One of the major difficulties in the rare earth elements separation is purification of yttrium from heavy rare earth elements. Thus, an HPLC method using acetic acid as novel eluent was explored for selective separation of yttrium form the heavy rare earth elements. When acetic acid is used as a mobile phase yttrium eluted with the lighter lanthanides. This is contrary to its relative position amongst heavier lanthanides when eluents commonly used for separation of rare earth elements were employed. The shift in elution position of yttrium with acetic acid as eluent may reflect a relatively lower stability constant of the yttrium-AcOH complex (in the same order as for the lighter lanthanides) compared to the corresponding AcOH complexes with heavy lanthanides, enabling selective separation of yttrium from the latter. The method was successfully used for selective separation of yttrium in mixed rare earth sample containing about 80% of yttrium and about 20% of heavy rare earth oxides. Thus, the use of AcOH as eluent is an effective approach for separating and determining the trace amounts of heavy rare earth elements in large amounts of yttrium matrix. Separation was performed on C18 column by running appropriate elution programs. The effluent from the column was monitored with diode array detector at absorbance wavelength of 658nm after post column derivatization with Arsenazo III.

  4. Laser isotope separation

    DOEpatents

    Robinson, C. Paul; Jensen, Reed J.; Cotter, Theodore P.; Boyer, Keith; Greiner, Norman R.

    1988-01-01

    A process and apparatus for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photolysis, photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photolysis, photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium.

  5. Photochemical isotope separation

    DOEpatents

    Robinson, C. Paul; Jensen, Reed J.; Cotter, Theodore P.; Greiner, Norman R.; Boyer, Keith

    1987-01-01

    A process for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium and plutonium.

  6. Photochemical isotope separation

    DOEpatents

    Robinson, C.P.; Jensen, R.J.; Cotter, T.P.; Greiner, N.R.; Boyer, K.

    1987-04-28

    A process is described for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium and plutonium. 8 figs.

  7. Laser isotope separation

    DOEpatents

    Robinson, C.P.; Reed, J.J.; Cotter, T.P.; Boyer, K.; Greiner, N.R.

    1975-11-26

    A process and apparatus for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light is described. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photolysis, photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photolysis, photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium.

  8. Selected values of chemical thermodynamic properties: compounds of uranium, protactinium, thorium, actinium, and the alkali metals. Final report

    SciTech Connect

    Wagman, D.D.; Evans, W.H.; Parker, V.B.; Schumm, R.H.; Nuttall, R.L.

    1981-05-01

    This publication contains tables of recommended values for the standard enthalpies (heats) of formation, Gibbs (free) energies of formation, entropies, enthalpy contents and heat capacities at 298.15 K, and enthalpies of formation at O K for compounds of uranium, protactinium, thorium, actinium, lithium, sodium, potassium, rubidium, cesium, and francium.

  9. Synthesis of surface imprinted nanospheres for selective removal of uranium from simulants of Sambhar salt lake and ground water.

    PubMed

    Milja, Thazhathuparambil Elias; Prathish, Krishnapillai Padmajakumari; Prasada Rao, Talasila

    2011-04-15

    Imprinted polymer nanospheres for uranium were prepared by complexing uranyl ion on to quinoline-8-ol functionalized 3-aminopropyltrimethoxysilane modified silica nanoparticles followed by surface imprinting with 4-VP (4-vinyl pyridine), HEMA (2-hydroxy ethyl methacrylate) and EGDMA (ethylene glycol dimethacrylate) as the functional monomers and cross linking agent respectively with AIBN (2,2'-azo-bis-isobutyronitrile) as initiator and 2-methoxyethanol as the porogen. Non-imprinted polymer material was also prepared under similar conditions omitting uranyl ion. The above materials were used for solid phase extraction of uranium. Recent realization that its chemical toxicity is dominant than radiation hazards makes decontamination a relevant topic for environmental point of view, particularly in the light of projected global thrust for uranium fuel based atomic power plants. The material offers high retention capacity of 97.1 μmol g(-1) for 10 mg L(-1) of uranium that does not require tedious grinding and sieving steps, is water compatible and works in the pH range of 5-7, making it ideal for possible use in decontamination of polluted natural water samples or front end effluents of nuclear power reactors. PMID:21345587

  10. SOLVENT EXTRACTION PROCESS FOR URANIUM RECOVERY

    DOEpatents

    Clark, H.M.; Duffey, D.

    1958-06-17

    A process is described for extracting uranium from uranium ore, wherein the uranium is substantially free from molybdenum contamination. In a solvent extraction process for recovering uranium, uranium and molybdenum ions are extracted from the ore with ether under high acidity conditions. The ether phase is then stripped with water at a lower controiled acidity, resaturated with salting materials such as sodium nitrate, and reextracted with the separation of the molybdenum from the uranium without interference from other metals that have been previously extracted.

  11. Uranium droplet core nuclear rocket

    NASA Technical Reports Server (NTRS)

    Anghaie, Samim

    1991-01-01

    Uranium droplet nuclear rocket is conceptually designed to utilize the broad temperature range ofthe liquid phase of metallic uranium in droplet configuration which maximizes the energy transfer area per unit fuel volume. In a baseline system dissociated hydrogen at 100 bar is heated to 6000 K, providing 2000 second of Isp. Fission fragments and intense radian field enhance the dissociation of molecular hydrogen beyond the equilibrium thermodynamic level. Uranium droplets in the core are confined and separated by an axisymmetric vortex flow generated by high velocity tangential injection of hydrogen in the mid-core regions. Droplet uranium flow to the core is controlled and adjusted by a twin flow nozzle injection system.

  12. A multi-functional oil-water separator from a selectively pre-wetted superamphiphobic paper.

    PubMed

    Ge, Dengteng; Yang, Lili; Wang, Chenbo; Lee, Elaine; Zhang, Yongquan; Yang, Shu

    2015-04-11

    A multi-functional oil-water separator is prepared from a paper towel spray coated with superamphiphobic (i.e., superhydrophobic and superoleophobic) nanoparticles. After the separator is pre-wetted with ethanol, followed by water, water can be removed from the light oil-water mixture and emulsions by gravity with high separation efficiency (99.9%) and separation flux. Vice versa, heavy oil can be removed by gravity on an ethanol-oil pre-wetted SA-paper.

  13. Chromatographic characterization of hydrophilic interaction liquid chromatography stationary phases: hydrophilicity, charge effects, structural selectivity, and separation efficiency.

    PubMed

    Kawachi, Yuusuke; Ikegami, Tohru; Takubo, Hirotaka; Ikegami, Yuka; Miyamoto, Masatoshi; Tanaka, Nobuo

    2011-09-01

    Fourteen commercially available particle-packed columns and a monolithic column for hydrophilic interaction liquid chromatography (HILIC) were characterized in terms of the degree of hydrophilicity, the selectivity for hydrophilic-hydrophobic substituents, the selectivity for the regio and configurational differences in hydrophilic substituents, the selectivity for molecular shapes, the evaluation of electrostatic interactions, and the evaluation of the acidic-basic nature of the stationary phases using nucleoside derivatives, phenyl glucoside derivatives, xanthine derivatives, sodium p-toluenesulfonate, and trimethylphenylammonium chloride as a set of samples. Principal component analysis based on the data of retention factors could separate three clusters of the HILIC phases. The column efficiency and the peak asymmetry factors were also discussed. These data on the selectivity for partial structural differences were summarized as radar-shaped diagrams. This method of column characterization is helpful to classify HILIC stationary phases on the basis of their chromatographic properties, and to choose better columns for targets to be separated. Judging from the retention factor for uridine, these HILIC columns could be separated into two groups: strongly retentive and weakly retentive stationary phases. Among the strongly retentive stationary phases, zwitterionic and amide functionalities were found to be the most selective on the basis of partial structural differences. The hydroxyethyl-type stationary phase showed the highest retention factor, but with low separation efficiency. Weakly retentive stationary phases generally showed lower selectivity for partial structural differences. PMID:21782195

  14. High resolution capillary column development for selective separations in gas chromatography

    SciTech Connect

    Przybyciel, M.

    1985-01-01

    A review of techniques for the preparation of high resolution capillary columns for gas chromatography is presented. Surface roughing, surface deactivation, stationary phase coating, and stationary phase crosslinking are discussed. Criteria for the selection of GC stationary phases and procedures for column evaluation are presented. A method is proposed for the isolation and determination of crude oil contamination in tropical plants and sediments. The method uses Florisil (TM) chromatography for the simultaneous clean-up and fractionation of aliphatic and aromatic hydrocarbons. Crosslinked SE-54 fused silica capillary columns prepared in our laboratory were employed for all GC separations. Mass spectrometry was used to help locate and identify specific oil components despite the intense background of the chromatogram. Crude oil components were identified in extracts of mangrove plant samples collected from the Peck Slip oil spill site at Media Munda, Puerto Rico. Crude oil components were also identified in sediment samples from controlled oil spill of Prudhoe Bay oil at Laguna de Chiriqui, Panama.

  15. Fluorous microgel star polymers: selective recognition and separation of polyfluorinated surfactants and compounds in water.

    PubMed

    Koda, Yuta; Terashima, Takaya; Sawamoto, Mitsuo

    2014-11-01

    Immiscible with either hydrophobic or hydrophilic solvents, polyfluorinated compounds (PFCs) are generally "fluorous", some of which have widely been employed as surfactants and water/oil repellents. Given the prevailing concern about the environmental pollution and the biocontamination by PFCs, their efficient removal and recycle from industrial wastewater and products are critically required. This paper demonstrates that fluorous-core star polymers consisting of a polyfluorinated microgel core and hydrophilic PEG-functionalized arms efficiently and selectively capture PFCs in water into the cores by fluorous interaction. For example, with over 10 000 fluorine atoms in the core and approximately 100 hydrophilic arms, the fluorous stars remove perfluorooctanoic acid (PFOA) and related PFCs in water from 10 ppm to as low as a parts per billion (ppb) level, or an over 98% removal. Dually functionalized microgel-core star polymers with perfluorinated alkanes and additional amino (or ammonium) groups cooperatively recognize PFOA or its ammonium salt and, in addition, release the guests upon external stimuli. The "smart" performance shows that the fluorous-core star polymers are promising PFC separation, recovery, and recycle materials for water purification toward sustainable society.

  16. Feature Selection and Blind Source Separation in an EEG-Based Brain-Computer Interface

    NASA Astrophysics Data System (ADS)

    Peterson, David A.; Knight, James N.; Kirby, Michael J.; Anderson, Charles W.; Thaut, Michael H.

    2005-12-01

    Most EEG-based BCI systems make use of well-studied patterns of brain activity. However, those systems involve tasks that indirectly map to simple binary commands such as "yes" or "no" or require many weeks of biofeedback training. We hypothesized that signal processing and machine learning methods can be used to discriminate EEG in a direct "yes"/"no" BCI from a single session. Blind source separation (BSS) and spectral transformations of the EEG produced a 180-dimensional feature space. We used a modified genetic algorithm (GA) wrapped around a support vector machine (SVM) classifier to search the space of feature subsets. The GA-based search found feature subsets that outperform full feature sets and random feature subsets. Also, BSS transformations of the EEG outperformed the original time series, particularly in conjunction with a subset search of both spaces. The results suggest that BSS and feature selection can be used to improve the performance of even a "direct," single-session BCI.

  17. Tweezing-adsorptive bubble separation. Analytical method for the selective and high enrichment of metalloenzymes.

    PubMed

    Gerken, Birte M; Wattenbach, Carsten; Linke, Diana; Zorn, Holger; Berger, Ralf G; Parlar, Harun

    2005-10-01

    A novelly developed tweezing-adsorptive bubble separation (ABS) method for the enrichment of metalloenzymes (laccase C and horseradish peroxidase) is introduced. The method is based on the chelation of the enzymes' active center and can also be applied for analysis. N-(2-acetamido)iminodiacetic acid served as a chelator and was synthesized with an octyl unit to become ADA-C8. Laccase was enriched 13.3-fold (66.31% recovery) and HPOX 17.8-fold (85.34%) without a significant loss of enzymatic activity. To prove that the entire enzyme is tweezed at the active center, ABS trials were done using ADA-C8 already complexed with Cu2+ and Fe3+. As only marginal enrichment occurred (ER laccase, 0.17; ER HPOX, 0.44), no chelating effect was concluded. It was determined how the chelation toward the active center was directed by applying other chelators such as EDTA, NTA, N,N-dimethylaminoglycine, oxalic acid, malonic acid, adipinic acid, and tripropylamine, which are similar in structure to ADA-C8. The results concluded that the chelation is 3-fold coordinated on the type 1 copper center of laccase, whereas that of HPOX only 1-fold at Fe3+ and additionally at the cationic amino acid arginine, which is also located at the active center. Tweezing-ABS has been proven to selectively and effectively enrich metalloenzymes.

  18. Recovery of uranium from seawater

    SciTech Connect

    Sugasaka, K.; Katoh, S.; Takai, N.; Takahashi, H.; Umezawa, Y.

    1981-01-01

    Seawater contains various elements in solution. Deuterium, lithium, and uranium are the important ingredients for energy application at present and in the future. This paper deals with the recovery of uranium from seawater, with emphasis on the development of an adsorbent with high selectivity and rate of adsorption for uranium. Polyacrylamidoxime chelating resins were synthesized from various co-polymers of acrylonitrile and cross-linking agents. The resulting resins with the chelating amidoxime group showed selective adsorption for uranium in seawater. The amount of uranium adsorbed from seawater at room temperature reached 3.2 mg/g resin after 180 days. Polyacrylamidoxime fiber, which was prepared from polyacrylonitrile fiber and hydroxylamine, showed a high rate of adsorption for uranium. The polyacrylamidoxime fiber conditioned with 1 M HC1 and 1 M NaOH adsorbed 4 mg U/g fiber from seawater in ten days. 9 figures, 6 tables.

  19. Ultrafast separation of fluorinated and desfluorinated pharmaceuticals using highly efficient and selective chiral selectors bonded to superficially porous particles.

    PubMed

    Barhate, Chandan L; Breitbach, Zachary S; Pinto, Eduardo Costa; Regalado, Erik L; Welch, Christopher J; Armstrong, Daniel W

    2015-12-24

    The separation of fluorinated active pharmaceutical ingredients (APIs) from their desfluoro analogs is a challenging analytical task due to their structural similarity. In this work, fluorine containing APIs and their corresponding desfluorinated impurities were separated on five new 2.7μm superficially porous particles (SPPs) functionalized with bonded chiral selectors. The unique shape selectivity of bonded macrocyclic glycopeptides and oligosaccharides was utilized to separate seven pairs of fluoro/desfluoro APIs resulting in some unprecedented selectivity values. For example, SPP bonded isopropyl cyclofructan 6 yielded a selectivity of 2.73 for voriconazole and desfluoro voriconazole. Further, the SPP based columns allowed for rapid separations ranging from 9 to 55s with very high efficiencies ranging from 45,000 to 70,000plates/m (at high flow rates) in both reversed phase and polar organic modes. Chromatographic separation and detection by HPLC-ESI-MS was demonstrated using ezetimibe and voriconazole and their desfluorinated impurities. Among the tested phases, SPP hydroxypropyl-β-cyclodextrin separated the most fluorinated and desfluorinated analogs with baseline resolution. PMID:26643720

  20. Selection of reversed-phase liquid chromatographic columns with diverse selectivity towards the potential separation of impurities in drugs.

    PubMed

    Van Gyseghem, E; Jimidar, M; Sneyers, R; Redlich, D; Verhoeven, E; Massart, D L; Vander Heyden, Y

    2004-07-01

    To select appropriate stationary phases from the continuously expanding supply of potentially suitable HPLC columns, the properties of 28 frequently applied stationary phases were determined by measuring several chromatographic parameters. From these results, based on chromatographic expertise, eight stationary phases with different properties and selectivities were selected. The aim of this study is to apply chemometric tools to evaluate the initially selected set of columns, i.e. a more systematic approach for making such a selection is examined. Starting from the information obtained on the 28 stationary phases, the re-evaluation was performed independently based on the chemometric techniques Pareto-optimality, principal component analysis (PCA), and Derringer's desirability functions. The aim was to select a set of efficient columns exhibiting large selectivity differences. The chemometrically selected stationary phases were divided in groups based on hydrophobicity, a critical retention-determining property in reversed-phase chromatography. This allowed to further reducing the selection to three columns. It is demonstrated that the selection by the chemometric approaches in general is fairly comparable with the initial selection.

  1. 300 Area Uranium Stabilization Through Polyphosphate Injection: Final Report

    SciTech Connect

    Vermeul, Vincent R.; Bjornstad, Bruce N.; Fritz, Brad G.; Fruchter, Jonathan S.; Mackley, Rob D.; Newcomer, Darrell R.; Mendoza, Donaldo P.; Rockhold, Mark L.; Wellman, Dawn M.; Williams, Mark D.

    2009-06-30

    The objective of the treatability test was to evaluate the efficacy of using polyphosphate injections to treat uranium-contaminated groundwater in situ. A test site consisting of an injection well and 15 monitoring wells was installed in the 300 Area near the process trenches that had previously received uranium-bearing effluents. This report summarizes the work on the polyphosphate injection project, including bench-scale laboratory studies, a field injection test, and the subsequent analysis and interpretation of the results. Previous laboratory tests have demonstrated that when a soluble form of polyphosphate is injected into uranium-bearing saturated porous media, immobilization of uranium occurs due to formation of an insoluble uranyl phosphate, autunite [Ca(UO2)2(PO4)2•nH2O]. These tests were conducted at conditions expected for the aquifer and used Hanford soils and groundwater containing very low concentrations of uranium (10-6 M). Because autunite sequesters uranium in the oxidized form U(VI) rather than forcing reduction to U(IV), the possibility of re-oxidation and subsequent re-mobilization is negated. Extensive testing demonstrated the very low solubility and slow dissolution kinetics of autunite. In addition to autunite, excess phosphorous may result in apatite mineral formation, which provides a long-term source of treatment capacity. Phosphate arrival response data indicate that, under site conditions, the polyphosphate amendment could be effectively distributed over a relatively large lateral extent, with wells located at a radial distance of 23 m (75 ft) reaching from between 40% and 60% of the injection concentration. Given these phosphate transport characteristics, direct treatment of uranium through the formation of uranyl-phosphate mineral phases (i.e., autunite) could likely be effectively implemented at full field scale. However, formation of calcium-phosphate mineral phases using the selected three-phase approach was problematic. Although

  2. Evaluation of health risks associated with proposed ground water standards at selected inactive uranium mill-tailings sites

    SciTech Connect

    Hamilton, L.D.; Medeiros, W.H.; Meinhold, A.; Morris, S.C.; Moskowitz, P.D.; Nagy, J.; Lackey, K.

    1989-04-01

    The US Environmental Protection Agency (EPA) has proposed ground water standards applicable to all inactive uranium mill-tailings sites. The proposed standards include maximum concentration limits (MCL) for currently regulated drinking water contaminants, as well as the addition of standards for molybdenum, uranium, nitrate, and radium-226 plus radium-228. The proposed standards define the point of compliance to be everywhere downgradient of the tailings pile, and require ground water remediation to drinking water standards if MCLs are exceeded. This document presents a preliminary description of the Phase 2 efforts. The potential risks and hazards at Gunnison, Colorado and Lakeview, Oregon were estimated to demonstrate the need for a risk assessment and the usefulness of a cost-benefit approach in setting supplemental standards and determining the need for and level of restoration at UMTRA sites. 8 refs., 12 tabs.

  3. DISSOLUTION OF URANIUM FUELS BY MONOOR DIFLUOROPHOSPHORIC ACID

    DOEpatents

    Johnson, R.; Horn, F.L.; Strickland, G.

    1963-05-01

    A method of dissolving and separating uranium from a uranium matrix fuel element by dissolving the uraniumcontaining matrix in monofluorophosphoric acid and/or difluorophosphoric acid at temperatures ranging from 150 to 275 un. Concent 85% C, thereafter neutralizing the solution to precipitate uranium solids, and converting the solids to uranium hexafluoride by treatment with a halogen trifluoride is presented. (AEC)

  4. Separated at birth: the interlinked origins of Darwin's unconscious selection concept and the application of sexual selection to race.

    PubMed

    Alter, Stephen G

    2007-01-01

    This essay traces the interlinked origins of two concepts found in Charles Darwin's writings: "unconscious selection," and sexual selection as applied to humanity's anatomical race distinctions. Unconscious selection constituted a significant elaboration of Darwin's artificial selection analogy. As originally conceived in his theoretical notebooks, that analogy had focused exclusively on what Darwin later would call "methodical selection," the calculated production of desired changes in domestic breeds. By contrast, unconscious selection produced its results unintentionally and at a much slower pace. Inspiration for this concept likely came from Darwin's early reading of works on both animal breeding and physical ethnology. Texts in these fields described the slow and unplanned divergence of anatomical types, whether animal or human, under the guidance of contrasting ideals of physical perfection. These readings, it is argued, also led Darwin to his theory of sexual selection as applied to race, a theme he discussed mainly in his book The Descent of Man (1871). There Darwin described how the racial version of sexual selection operated on the same principle as unconscious selection. He thereby effectively reunited these kindred concepts.

  5. Mass, charge, and energy separation by selective acceleration with a traveling potential hill

    NASA Astrophysics Data System (ADS)

    Tung, L. Schwager; Barr, W. L.; Lowder, R. S.; Post, R. F.

    1996-10-01

    A traveling electric potential hill has been used to generate an ion beam with an energy distribution that is mass dependent from a monoenergetic ion beam of mixed masses. This effect can be utilized as a novel method for mass separation applied to identification or enrichment of ions (e.g., of elements, isotopes, or molecules). This theory for mass-selective acceleration is presented here and is shown to be confirmed by experiment and by a time-dependent particle-in-cell computer simulation. Results show that monoenergetic ions with the particular mass of choice are accelerated by controlling the hill potential and the hill velocity. The hill velocity is typically 20%-30% faster than the ions to be accelerated. The ability of the hill to pickup a particular mass uses the fact that small kinetic energy differences in the lab frame appear much larger in the moving hill frame. Ions will gain energy from the approaching hill if their relative energy in the moving hill frame is less than the peak potential of the hill. The final energy of these accelerated ions can be several times the source energy, which facilitates energy filtering for mass purification or identification. If the hill potential is chosen to accelerate multiple masses, the heaviest mass will have the greatest final energy. Hence, choosing the appropriate hill potential and collector retarding voltage will isolate ions with the lightest, heaviest, or intermediate mass. In the experimental device, called a Solitron, purified 20Ne and 22Ne are extracted from a ribbon beam of neon that is originally composed of 20Ne:22Ne in the natural ratio of 91:9. The isotopic content of the processed beam is determined by measuring the energy distribution of the detected current. These results agree with the theory. In addition to mass selectivity, our theory can also be applied to the filtration of an ion beam according to charge state or energy. Because of this variety of properties, the Solitron is envisioned to

  6. Evidence for isolated evolution of deep-sea ciliate communities through geological separation and environmental selection

    PubMed Central

    2013-01-01

    Background Deep hypersaline anoxic basins (DHABs) are isolated habitats at the bottom of the eastern Mediterranean Sea, which originate from the ancient dissolution of Messinian evaporites. The different basins have recruited their original biota from the same source, but their geological evolution eventually constituted sharp environmental barriers, restricting genetic exchange between the individual basins. Therefore, DHABs are unique model systems to assess the effect of geological events and environmental conditions on the evolution and diversification of protistan plankton. Here, we examine evidence for isolated evolution of unicellular eukaryote protistan plankton communities driven by geological separation and environmental selection. We specifically focused on ciliated protists as a major component of protistan DHAB plankton by pyrosequencing the hypervariable V4 fragment of the small subunit ribosomal RNA. Geospatial distributions and responses of marine ciliates to differential hydrochemistries suggest strong physical and chemical barriers to dispersal that influence the evolution of this plankton group. Results Ciliate communities in the brines of four investigated DHABs are distinctively different from ciliate communities in the interfaces (haloclines) immediately above the brines. While the interface ciliate communities from different sites are relatively similar to each other, the brine ciliate communities are significantly different between sites. We found no distance-decay relationship, and canonical correspondence analyses identified oxygen and sodium as most important hydrochemical parameters explaining the partitioning of diversity between interface and brine ciliate communities. However, none of the analyzed hydrochemical parameters explained the significant differences between brine ciliate communities in different basins. Conclusions Our data indicate a frequent genetic exchange in the deep-sea water above the brines. The “isolated island

  7. Highly selective separation and purification of anthocyanins from bilberry based on a macroporous polymeric adsorbent.

    PubMed

    Yao, Lijuan; Zhang, Na; Wang, Chenbiao; Wang, Chunhong

    2015-04-01

    Powdered bilberry extract (United States Pharmacopoeia, USP35-NF30), which is prepared from ripe bilberry fruits (Vaccinium myrtillus L.), is the main ingredient of drugs alleviating visual fatigue and diabetic retinopathy because of the rich anthocyanins (purity of 36%). In this study, a method based on a macroporous polymeric adsorbent was established to obtain anthocyanin compounds from bilberry, in which the purity of the anthocyanins was improved to 96%, conducive to further pharmacological research and improvement of the efficiency of the drug. On the basis of the structure of anthocyanins, we designed a series of macroporous polymeric adsorbents based on the copolymerization of divinylbenzene (DVB) and ethylene glycol dimethyl acrylate (EGDMA). In this situation, EGDMA not only regulated the polarity of the adsorbent but also acted as the cross-linking agent to ensure the matrix structure of the adsorbent, which had a high specific surface area and could provide more interaction sites during adsorption with anthocyanins. Among the synthesized polymeric adsorbents with different contents of EGDMA, the one with 20% EGDMA content (DE-20) was demonstrated to exhibit optimal adsorption capacity and selectivity to anthocyanins compared to various commercial adsorbents through static adsorption and desorption experiments. In addition, the optimum condition of the dynamic adsorption-desorption experiment was further explored. The results indicated that the purity of anthocyanins after rinsing with 20% ethanol was determined to be approximately 96% at a desorption ratio of 83%, which was clearly higher than that in powdered bilberry extract. The established separation and purification method of anthocyanins with high purity is expected to be applied in industrial production. PMID:25786117

  8. A multi-functional oil-water separator from a selectively pre-wetted superamphiphobic paper.

    PubMed

    Ge, Dengteng; Yang, Lili; Wang, Chenbo; Lee, Elaine; Zhang, Yongquan; Yang, Shu

    2015-04-11

    A multi-functional oil-water separator is prepared from a paper towel spray coated with superamphiphobic (i.e., superhydrophobic and superoleophobic) nanoparticles. After the separator is pre-wetted with ethanol, followed by water, water can be removed from the light oil-water mixture and emulsions by gravity with high separation efficiency (99.9%) and separation flux. Vice versa, heavy oil can be removed by gravity on an ethanol-oil pre-wetted SA-paper. PMID:25750982

  9. Removal of uranium from aqueous HF solutions

    DOEpatents

    Pulley, Howard; Seltzer, Steven F.

    1980-01-01

    This invention is a simple and effective method for removing uranium from aqueous HF solutions containing trace quantities of the same. The method comprises contacting the solution with particulate calcium fluoride to form uranium-bearing particulates, permitting the particulates to settle, and separting the solution from the settled particulates. The CaF.sub.2 is selected to have a nitrogen surface area in a selected range and is employed in an amount providing a calcium fluoride/uranium weight ratio in a selected range. As applied to dilute HF solutions containing 120 ppm uranium, the method removes at least 92% of the uranium, without introducing contaminants to the product solution.

  10. Self-Report Measures of Parent-Adolescent Attachment and Separation-Individuation: A Selective Review.

    ERIC Educational Resources Information Center

    Lopez, Frederick G.; Gover, Mark R.

    1993-01-01

    Reviews and critiques three self-report measures of parent-adolescent attachment (Parental Bonding Instrument, Parental Attachment Questionnaire, Inventory of Parent and Peer Attachment) and three self-report measures of parent-adolescent separation-individuation (Psychological Separation Inventory, Personal Authority in the Family System…

  11. Magnetically separable nanocomposites with photocatalytic activity under visible light for the selective transformation of biomass-derived platform molecules

    EPA Science Inventory

    Novel magnetically separable TiO2-guanidine-(Ni,Co)Fe2O4 nanomaterials were prepared and characterised by a series of techniques including XRD, SEM, TEM, N2 physisorption as well as XPS and subsequently tested for their photocatalytic activities in the selective transformation of...

  12. Selective separation of sodium ions from a mixture with phenylalanine by Donnan dialysis with a profiled sulfogroup cation exchange membrane

    NASA Astrophysics Data System (ADS)

    Vasil'eva, V. I.; Goleva, E. A.

    2013-11-01

    The possibility of separating ions of metal from a mixture with ampholyte (an amino acid) by Donnan dialysis with an MK-40 sulfogroup cation exchange membrane is demonstrated. Conditions ensuring the selectivity and intensity of the mass transfer of sodium ions from a mixture with bipolar phenylalanine ions into a diffusate containing hydrochloric acid through a cation exchange membrane are found.

  13. Fort St. Vrain graphite site mechanical separation concept selection. Final report

    SciTech Connect

    Berry, S.M.

    1993-09-01

    One of the alternatives to the disposal of the Fort St. Vrain (FSV) reactor spent nuclear fuel involves the separation of the fuel rods composed of compacts from the graphite fuel block assembly. After the separation of these two components, the empty graphite fuel blocks would be disposed of as a low level waste (provided the appropriate requirements are met) and the fuel compacts would be treated as high level waste material. This report deals with the mechanical separation aspects concerning physical disassembly of the FSV graphite fuel element into the empty graphite fuel blocks and fuel compacts. This report recommends that a drilling technique is the preferred choice for accessing the, fuel channel holes and that each hole is drilled separately. This report does not cover any techniques or methods to separate the triso fuel particles from the graphite matrix of the fuel compacts.

  14. METHOD OF APPLYING NICKEL COATINGS ON URANIUM

    DOEpatents

    Gray, A.G.

    1959-07-14

    A method is presented for protectively coating uranium which comprises etching the uranium in an aqueous etching solution containing chloride ions, electroplating a coating of nickel on the etched uranium and heating the nickel plated uranium by immersion thereof in a molten bath composed of a material selected from the group consisting of sodium chloride, potassium chloride, lithium chloride, and mixtures thereof, maintained at a temperature of between 700 and 800 deg C, for a time sufficient to alloy the nickel and uranium and form an integral protective coating of corrosion-resistant uranium-nickel alloy.

  15. Selective Separation of Trivalent Actinides from Lanthanides by Aqueous Processing with Introduction of Soft Donor Atoms

    SciTech Connect

    Kenneth L. Nash; Sue B. Clark; Gregg Lumetta

    2009-09-23

    With increased application of MOX fuels and longer burnup times for conventional fuels, higher concentrations of the transplutonium actinides Am and Cm (and even heavier species like Bk and Cf) will be produced. The half-lives of the Am isotopes are significantly longer than those of the most important long-lived, high specific activity lanthanides or the most common Cm, Bk and Cf isotopes, thus the greatest concern as regards long-term radiotoxicity. With the removal and transmutation of Am isotopes, radiation levels of high level wastes are reduced to near uranium mineral levels within less than 1000 years as opposed to the time-fram if they remain in the wastes.

  16. ELECTROCHEMICAL DECONTAMINATION AND RECOVERY OF URANIUM VALUES

    DOEpatents

    McLaren, J.A.; Goode, J.H.

    1958-05-13

    An electrochemical process is described for separating uranium from fission products. The method comprises subjecting the mass of uranium to anodic dissolution in an electrolytic cell containing aqueous alkali bicarbonate solution as its electrolyte, thereby promoting a settling from the solution of a solid sludge from about the electrodes and separating the resulting electrolyte solution containing the anodically dissolved uranium from the sludge which contains the rare earth fission products.

  17. Hydrothermal alteration of organic matter in uranium ores, Elliot Lake, Canada: Implications for selected organic-rich deposits

    SciTech Connect

    Mossman, D.J.; Nagy, B.; Davis, D.W.

    1993-07-01

    Organic matter in the uraniferous Matinenda Formation, Elliot Lake, is preserved in the forms of syngenetic kerogen and solid bitumen as it is in many of the Oklo uranium deposits and in the Witwatersrand gold-uranium ores. The Elliot Lake kerogen is a vitrinite-like material considered to be remnants of the Precambrian cyanobacterial mats. The kerogen at Elliot Lake has reflectances (in oil) ranging from 2.63-7.31% RO{sub max}, high aromaticity, relatively low (0.41-0.60) atomic H/C ratios, and it contains cryptocrystalline graphite. Bitumen, present primarily as dispersed globules (up to 0.5 mm dia.), has reflectances from 0.72-1.32% RO{sub max}, atomic H/C ratios of 0.71-0.81, and is somewhat less aromatic than the kerogen. Overall similarity in molecular compositions indicates that liquid bitumen was derived from kerogen by processes similar to hydrous pyrolysis. The carbon isotopic composition of kerogen ({minus}15.62 to {minus}24.72%), and the now solid bitumen ({minus}25.91 to {minus}33.00%) are compatible with these processes. Despite having been subjected to several thermal episodes, ca. 2.45 Ga old kerogen of microbiological origin here survived as testimony of the antiquity of life on Earth. U-Pb isotopic data from discrete kerogen grains at Elliot Lake form a scattered array intersecting concordia at 2130 {+-} 100 Ma, correspond to the Nipissing event. U-Pb systems were totally reset by this event. Uranium and lead show subsequently partial mobility, the average of which is indicated by the lower concordia intersect of 550 {+-} 260 Ma. The migrated bitumen contains virtually no uranium and thorium but has a large excess of {sup 206}Pb, which indicates that the once liquid bitumen must have acted as a sink for mobile intermediate decay products of {sup 238}U. Emplacement of the Nipissing diabase may have been responsible for producing the bitumen and, indirectly, for its enrichment in {sup 206}Pb as a result of outgassing of {sup 222}Rn.

  18. BASIC PEROXIDE PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM CONTAMINANTS

    DOEpatents

    Seaborg, G.T.; Perlman, I.

    1959-02-10

    A process is described for the separation from each other of uranyl values, tetravalent plutonium values and fission products contained in an aqueous acidic solution. First the pH of the solution is adjusted to between 2.5 and 8 and hydrogen peroxide is then added to the solution causing precipitation of uranium peroxide which carries any plutonium values present, while the fission products remain in solution. Separation of the uranium and plutonium values is then effected by dissolving the peroxide precipitate in an acidic solution and incorporating a second carrier precipitate, selective for plutonium. The plutonium values are thus carried from the solution while the uranium remains flissolved. The second carrier precipitate may be selected from among the group consisting of rare earth fluorides, and oxalates, zirconium phosphate, and bismuth lihosphate.

  19. PROCESS OF RECOVERING URANIUM

    DOEpatents

    Price, T.D.; Jeung, N.M.

    1958-06-17

    An improved precipitation method is described for the recovery of uranium from aqueous solutions. After removal of all but small amounts of Ni or Cu, and after complexing any iron present, the uranium is separated as the peroxide by adding H/sub 2/O/sub 2/. The improvement lies in the fact that the addition of H/sub 2/O/sub 2/ and consequent precipitation are carried out at a temperature below the freezing; point of the solution, so that minute crystals of solvent are present as seed crystals for the precipitation.

  20. Pervaporation & Vapor Permeation Membrane Processes for the Selective Separation of Liquid and Vapor Mixtures

    EPA Science Inventory

    Pervaporation and vapor permeation are membrane-based processes which have been proposed as alternatives to conventional separation technologies. Applications range from organic solvent removal from water, ethanol or butanol recovery from dilute fermentation broths, solvent/biofu...

  1. Pervaporation and Vapor Permeation Tutorial: Membrane Processes for the Selective Separation of Liquid and Vapor Mixtures

    EPA Science Inventory

    Pervaporation and vapor permeation are membrane-based processes proposed as alternatives to conventional separation technologies. Applications range from organic solvent removal from water, ethanol or butanol recovery from fermentation broths, solvent/biofuel dehydration to meet ...

  2. Geomorphic criteria for selecting stable uranium tailings disposal sites in New Mexico. Volume 1. Technical report. Final report

    SciTech Connect

    Wells, S.G.; Gardner, T.W.

    1985-03-01

    Essential to the disposal of uranium mill tailings in northwestern New Mexico is the geomorphic stability of the disposal site. Geomorphic stability assessment involves 3 steps: (1) evaluating the site's past geomorphic stability by determining the age of the landscape and its associated deposits; (2) quantifying short- and long-term geomorphic processes operating in the site area; and (3) evaluating the impact of mining activity and reclamation on the geomorphic stability of the site area. A heirarchy of geomorphic hazards which might impact a site area include: (1) drainage network extension/channel headcutting, (2) piping and gullying, (3) bank erosion and meander growth, (4) drainage network and channel incision, (5) channel aggradation, and (6) valley floor deposition and wind erosion. All of these processes operate on a scale of meters of change per year over historic time periods. Landscapes which have undergone significant changes in historic and Holocene time periods are valley floors. Valley floors are considered one of the most unstable landscapes for siting of uranium mill tailings.

  3. Separation by solvent extraction

    DOEpatents

    Holt, Jr., Charles H.

    1976-04-06

    17. A process for separating fission product values from uranium and plutonium values contained in an aqueous solution, comprising adding an oxidizing agent to said solution to secure uranium and plutonium in their hexavalent state; contacting said aqueous solution with a substantially water-immiscible organic solvent while agitating and maintaining the temperature at from -1.degree. to -2.degree. C. until the major part of the water present is frozen; continuously separating a solid ice phase as it is formed; separating a remaining aqueous liquid phase containing fission product values and a solvent phase containing plutonium and uranium values from each other; melting at least the last obtained part of said ice phase and adding it to said separated liquid phase; and treating the resulting liquid with a new supply of solvent whereby it is practically depleted of uranium and plutonium.

  4. METHOD OF PRODUCING URANIUM

    DOEpatents

    Foster, L.S.; Magel, T.T.

    1958-05-13

    A modified process is described for the production of uranium metal by means of a bomb reduction of UF/sub 4/. Difficulty is sometimes experienced in obtaining complete separation of the uranium from the slag when the process is carried out on a snnall scale, i.e., for the production of 10 grams of U or less. Complete separation may be obtained by incorporating in the reaction mixture a quantity of MnCl/sub 2/, so that this compound is reduced along with the UF/sub 4/ . As a result a U--Mn alloy is formed which has a melting point lower than that of pure U, and consequently the metal remains molten for a longer period allowing more complete separation from the slag.

  5. Atomic vapor laser isotope separation using resonance ionization

    SciTech Connect

    Comaskey, B.; Crane, J.; Erbert, G.; Haynam, C.; Johnson, M.; Morris, J.; Paisner, J.; Solarz, R.; Worden, E.

    1986-09-01

    Atomic vapor laser isotope separation (AVLIS) is a general and powerful technique. A major present application to the enrichment of uranium for light-water power-reactor fuel has been under development for over 10 years. In June 1985, the Department of Energy announced the selection of AVLIS as the technology to meet the nation's future need for enriched uranium. Resonance photoionization is the heart of the AVLIS process. We discuss those fundamental atomic parameters that are necessary for describing isotope-selective resonant multistep photoionization along with the measurement techniques that we use. We illustrate the methodology adopted with examples of other elements that are under study in our program.

  6. Selective population of the [1s2s] {sup 1}S{sub 0} and [1s2s] {sup 3}S{sub 1} states of He-like uranium

    SciTech Connect

    Rzadkiewicz, J.; Stoehlker, Th.; Gumberidze, A.; Reuschl, R.; Spillmann, U.; Tashenov, S.; Trotsenko, S.; Banas, D.; Beyer, H. F.; Bosch, F.; Brandau, C.; Ionescu, D. C.; Kozhuharov, C.; Nandi, T.; Dong, C. Z.; Fritzsche, S.; Surzhykov, A.; Gojska, A.; Hagmann, S.; Sierpowski, D.

    2006-07-15

    The formation of the [1s2s] S states in heliumlike uranium (U{sup 90+}) has been studied in relativistic collisions of initially lithiumlike uranium (U{sup 89+}) ions with N{sub 2} target molecules. By measuring projectile x-ray emission in coincidence with projectile ionization, a strong selectivity for the formation of the [1s2s] S states in heliumlike uranium is observed. This selectivity is found to be unaffected by the subsequent rearrangement of the atomic orbitals involved. By measuring the photon emission associated with the decay of the [1s2s] {sup 1}S{sub 0} and the [1s2s] {sup 3}S{sub 1} substates, we obtain for their relative population probabilities a ratio of close to 1. This finding deviates considerably from the assumption of a statistical distribution 2J+1.

  7. Investigation of thermal treatment on selective separation of post consumer plastics prior to froth flotation.

    PubMed

    Guney, Ali; Poyraz, M Ibrahim; Kangal, Olgac; Burat, Firat

    2013-09-01

    Plastics have become the widely used materials because of their advantages, such as cheapness, endurance, lightness, and hygiene. However, they cause waste and soil pollution and they do not easily decompose. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. Depending on their surface characteristics, these plastics can be separated from each other by flotation method which is useful mineral processing technique with its low cost and simplicity. The main objective of this study is to investigate the flotation characteristics of PET and PVC and determine the effect of plasticizer reagents on efficient plastic separation. For that purpose, various parameters such as pH, plasticizer concentration, plasticizer type, conditioning temperature and thermal conditioning were investigated. As a result, PET particles were floated with 95.1% purity and 65.3% efficiency while PVC particles were obtained with 98.1% purity and 65.3% efficiency.

  8. Separation of Niobium and Tantalum Pentafluoride by Selective Precipitation Using p-Phenylenediamine

    NASA Astrophysics Data System (ADS)

    Nete, M.; Purcell, W.; Nel, J. T.

    2016-07-01

    The similarity between Ta and Nb chemistry makes it difficult to find the appropriate reagents and chemical reactions for the separation of the two elements. This study investigated the precipitation behavior of TaF5 and NbF5 with p-phenylenediamine (PPDA). PPDA preferentially precipitated Nb from a 1:1 ratio of NbF5 and TaF5. Niobium recoveries of >80%, and only 4% Ta, were found in the precipitate of the reaction between (Nb/Ta)F5 and PPDA in ethanol. A separation factor of 100(9) indicated the potential for successful separation of Nb and Ta in a fluoride environment. A spectrophotometric study of the formation ratio of the newly formed Nb compound indicated a 1:1 metal:ligand ratio.

  9. Hydrogen Selective Inorganic membranes for Gas Separations under High Pressure Intermediate Temperature Hydrocarbonic Envrionment

    SciTech Connect

    Rich Ciora; Paul KT Liu

    2012-06-27

    In this project, we have successfully developed a full scale commercially ready carbon molecular sieve (CMS) based membrane for applications in H{sub 2} recovery from refinery waste and other aggressive gas streams. Field tests at a refinery pilot plant and a coal gasification facility have successfully demonstrated its ability to recovery hydrogen from hydrotreating and raw syngas respectively. High purity H{sub 2} and excellent stability of the membrane permeance and selectivity were obtained in testing conducted over >500 hours at each site. The results from these field tests as well as laboratory testing conclude that the membranes can be operated at high pressures (up to 1,000 psig) and temperatures (up to 300 C) in presence of aggressive contaminants, such as sulfur and nitrogen containing species (H{sub 2}S, CO{sub 2}, NH{sub 3}, etc), condensable hydrocarbons, tar-like species, heavy metals, etc. with no observable effect on membrane performance. By comparison, similar operating conditions and/or environments would rapidly destroy competing membranes, such as polymeric, palladium, zeolitic, etc. Significant cost savings can be achieved through recovering H{sub 2} from refinery waste gas using this newly developed CMS membrane. Annual savings of $2 to 4MM/year (per 20,000 scfd of waste gas) can be realized by recovering the H{sub 2} for reuse (versus fuel). Projecting these values over the entire US market, potential H{sub 2} savings from refinery waste gases on the order of 750 to 1,000MM scfd and $750 to $1,000MM per year are possible. In addition to the cost savings, potential energy savings are projected to be ca. 150 to 220 tBTU/yr and CO{sub 2} gas emission reductions are projected to be ca. 5,000 to 6,500MMtons/year. The full scale membrane bundle developed as part of this project, i.e., 85 x 30 inch ceramic membrane tubes packaged into a full ceramic potting, is an important accomplishment. No comparable commercial scale product exists in the

  10. URANIUM COMPOSITIONS

    DOEpatents

    Allen, N.P.; Grogan, J.D.

    1959-05-12

    This patent relates to high purity uranium alloys characterized by improved stability to thermal cycling and low thermal neutron absorption. The high purity uranium alloy contains less than 0.1 per cent by weight in total amount of any ore or more of the elements such as aluminum, silicon, phosphorous, tin, lead, bismuth, niobium, and zinc.

  11. Dilution of Recycled Uranium with Low-Enriched and Waste Uranium in a Cascade with Three Feeds

    NASA Astrophysics Data System (ADS)

    Smirnov, A. Yu.; Sulaberidze, G. A.

    The five-flow cascade to enrich recycled uranium with simultaneous its dilution with low-enriched uranium and waste uranium is proposed. The results of computational experiments show that the proposed cascade has the advantages in the consumption of natural uranium value of the separation work in comparison to both the previously proposed multi-flow cascades, and the standard cascade to enrich natural uranium.

  12. Transfer and the Part-Time Student: The Gulf Separating Community Colleges and Selective Universities

    ERIC Educational Resources Information Center

    Handel, Stephen J.

    2009-01-01

    When representatives from community colleges and selective four-year institutions gather, there is no greater flashpoint than the topic of part-time enrollment. This issue--that students coming from an institution comprising mostly part-time students should be enabled to transfer to selective four-year institutions in which full-time enrollment is…

  13. Solvent selection for cyclohexane-cyclohexene-benzene separation by extractive distillation using non-steady-state gas chromatography

    SciTech Connect

    Vega, A.; Diez, F.; Esteban, R.; Coca, J.

    1997-03-01

    The infinite-dilution activity coefficients of cyclohexane, cyclohexene, and benzene in N,N-dimethylformamide, N-methylpyrrolidone, N,N-dimethylacetamide, phenyl acetate, and dimethyl malonate have been determined at temperatures ranging from 40 to 80 C, by non-steady-state gas chromatography. From these data, the limiting selectivity-solvency properties for cyclohexane-benzene, cyclohexene-benzene, and cyclohexane-cyclohexene, in the presence of the aforementioned solvents, are studied, and the solvents tested are considered for the cyclohexane-cyclohexene-benzene separation by extractive distillation. According to the results, N,N-dimethylacetamide seems to be an adequate solvent for the cyclohexane-benzene and cyclohexene-benzene separations. The separation of cyclohexane-cyclohexene is the most difficult, in spite of the difference of boiling points, much higher than for cyclohexane-benzene.

  14. Selection of Genetic and Phenotypic Features Associated with Inflammatory Status of Patients on Dialysis Using Relaxed Linear Separability Method

    PubMed Central

    Bobrowski, Leon; Łukaszuk, Tomasz; Lindholm, Bengt; Stenvinkel, Peter; Heimburger, Olof; Axelsson, Jonas; Bárány, Peter; Carrero, Juan Jesus; Qureshi, Abdul Rashid; Luttropp, Karin; Debowska, Malgorzata; Nordfors, Louise; Schalling, Martin; Waniewski, Jacek

    2014-01-01

    Identification of risk factors in patients with a particular disease can be analyzed in clinical data sets by using feature selection procedures of pattern recognition and data mining methods. The applicability of the relaxed linear separability (RLS) method of feature subset selection was checked for high-dimensional and mixed type (genetic and phenotypic) clinical data of patients with end-stage renal disease. The RLS method allowed for substantial reduction of the dimensionality through omitting redundant features while maintaining the linear separability of data sets of patients with high and low levels of an inflammatory biomarker. The synergy between genetic and phenotypic features in differentiation between these two subgroups was demonstrated. PMID:24489753

  15. Water-Stable Anionic Metal-Organic Framework for Highly Selective Separation of Methane from Natural Gas and Pyrolysis Gas.

    PubMed

    Li, Lan; Wang, Xusheng; Liang, Jun; Huang, Yuanbiao; Li, Hongfang; Lin, Zujin; Cao, Rong

    2016-04-20

    A 3D water-stable anionic metal-organic framework [Zn4(hpdia)2]·[NH2(CH3)2]·3DMF·4H2O (FJI-C4) was constructed based on an elaborate phosphorus-containing ligand 5,5'-(hydroxyphosphoryl)diisophthalic acid (H5hpdia). FJI-C4 with narrow one-dimensional (1D) pore channels exhibits high selectivity of C3H8/CH4 and C2H2/CH4. It is the first time for the MOF which contains phosphorus for selective separation of methane from natural gas and pyrolysis gas.

  16. Theoretical Prediction of Am(III)/Eu(III) Selectivity to Aid the Design of Actinide-Lanthanide Separation Agents

    DOE PAGES

    Bryantsev, Vyacheslav S.; Hay, Benjamin P.

    2015-03-20

    Selective extraction of minor actinides from lanthanides is a critical step in the reduction of radiotoxicity of spent nuclear fuels. However, the design of suitable ligands for separating chemically similar 4f- and 5f-block trivalent metal ions poses a significant challenge. Furthermore, first-principles calculations should play an important role in the design of new separation agents, but their ability to predict metal ion selectivity has not been systematically evaluated. We examine the ability of several density functional theory methods to predict selectivity of Am(III) and Eu(III) with oxygen, mixed oxygen–nitrogen, and sulfur donor ligands. The results establish a computational method capablemore » of predicting the correct order of selectivities obtained from liquid–liquid extraction and aqueous phase complexation studies. To allow reasonably accurate predictions, it was critical to employ sufficiently flexible basis sets and provide proper account of solvation effects. The approach is utilized to estimate the selectivity of novel amide-functionalized diazine and 1,2,3-triazole ligands.« less

  17. Theoretical Prediction of Am(III)/Eu(III) Selectivity to Aid the Design of Actinide-Lanthanide Separation Agents

    SciTech Connect

    Bryantsev, Vyacheslav S.; Hay, Benjamin P.

    2015-03-20

    Selective extraction of minor actinides from lanthanides is a critical step in the reduction of radiotoxicity of spent nuclear fuels. However, the design of suitable ligands for separating chemically similar 4f- and 5f-block trivalent metal ions poses a significant challenge. Furthermore, first-principles calculations should play an important role in the design of new separation agents, but their ability to predict metal ion selectivity has not been systematically evaluated. We examine the ability of several density functional theory methods to predict selectivity of Am(III) and Eu(III) with oxygen, mixed oxygen–nitrogen, and sulfur donor ligands. The results establish a computational method capable of predicting the correct order of selectivities obtained from liquid–liquid extraction and aqueous phase complexation studies. To allow reasonably accurate predictions, it was critical to employ sufficiently flexible basis sets and provide proper account of solvation effects. The approach is utilized to estimate the selectivity of novel amide-functionalized diazine and 1,2,3-triazole ligands.

  18. SULFIDE METHOD PLUTONIUM SEPARATION

    DOEpatents

    Duffield, R.B.

    1958-08-12

    A process is described for the recovery of plutonium from neutron irradiated uranium solutions. Such a solution is first treated with a soluble sullide, causing precipitation of the plutoniunn and uraniunn values present, along with those impurities which form insoluble sulfides. The precipitate is then treated with a solution of carbonate ions, which will dissolve the uranium and plutonium present while the fission product sulfides remain unaffected. After separation from the residue, this solution may then be treated by any of the usual methods, such as formation of a lanthanum fluoride precipitate, to effect separation of plutoniunn from uranium.

  19. Expeditious method to determine uranium in the process control samples of chemical plant separating (233)U from thoria irradiated in power reactors.

    PubMed

    Kedari, C S; Kharwandikar, B K; Banerjee, K

    2016-11-01

    Analysis of U in the samples containing a significant proportion of (232)U and high concentration of Th is of great concern. Transmutation of Th in the nuclear power reactor produces a notable quantity of (232)U (half life 68.9 years) along with fissile isotope (233)U. The decay series of (232)U is initiated with (228)Th (half life 1.9 year) and it is followed by several short lived α emitting progenies, (224)Ra, (220)Rn, (216)Po, (212)Bi and (212)Po. Even at the smallest contamination of (228)Th in the sample, a very high pulse rate of α emission is obtained, which is to be counted for the radiometric determination of [U]. A commercially available anionic type of extractant Alamine®336 is used to obtain the selective extraction of U from other alpha active elements and fission products present in the sample. Experimental conditions of liquid-liquid extraction (LLE) are optimized for obtaining maximum decontamination and recovery of U in the organic phase. The effect of some interfering ionic impurities in the sample on the process of separation is investigated. Depending on the level of the concentration of U in the samples, spectrophotometry or radiometry methods are adopted for its determination after separation by LLE. Under optimized experimental conditions, i.e. 5.5M HCl in the aqueous phase and 0.27M Alamin®336 in the organic phase, the recovery of U is about 100%, the decontamination factor with respect to Th is >2000 and the extraction of fission products like (90)Sr, (144)Ce and (134,137)Cs is negligible. The detection limit for [U] using α radiometry is 10mg/L, even in presence of >100g/L of Th in the sample. Accuracy and precision for the determination of U is also assessed. Reproducibility of results is within 5%. This method shows very good agreement with the results obtained by mass spectrometry.

  20. Expeditious method to determine uranium in the process control samples of chemical plant separating (233)U from thoria irradiated in power reactors.

    PubMed

    Kedari, C S; Kharwandikar, B K; Banerjee, K

    2016-11-01

    Analysis of U in the samples containing a significant proportion of (232)U and high concentration of Th is of great concern. Transmutation of Th in the nuclear power reactor produces a notable quantity of (232)U (half life 68.9 years) along with fissile isotope (233)U. The decay series of (232)U is initiated with (228)Th (half life 1.9 year) and it is followed by several short lived α emitting progenies, (224)Ra, (220)Rn, (216)Po, (212)Bi and (212)Po. Even at the smallest contamination of (228)Th in the sample, a very high pulse rate of α emission is obtained, which is to be counted for the radiometric determination of [U]. A commercially available anionic type of extractant Alamine®336 is used to obtain the selective extraction of U from other alpha active elements and fission products present in the sample. Experimental conditions of liquid-liquid extraction (LLE) are optimized for obtaining maximum decontamination and recovery of U in the organic phase. The effect of some interfering ionic impurities in the sample on the process of separation is investigated. Depending on the level of the concentration of U in the samples, spectrophotometry or radiometry methods are adopted for its determination after separation by LLE. Under optimized experimental conditions, i.e. 5.5M HCl in the aqueous phase and 0.27M Alamin®336 in the organic phase, the recovery of U is about 100%, the decontamination factor with respect to Th is >2000 and the extraction of fission products like (90)Sr, (144)Ce and (134,137)Cs is negligible. The detection limit for [U] using α radiometry is 10mg/L, even in presence of >100g/L of Th in the sample. Accuracy and precision for the determination of U is also assessed. Reproducibility of results is within 5%. This method shows very good agreement with the results obtained by mass spectrometry. PMID:27591623

  1. Conversion of depleted uranium hexafluoride to a solid uranium compound

    DOEpatents

    Rothman, Alan B.; Graczyk, Donald G.; Essling, Alice M.; Horwitz, E. Philip

    2001-01-01

    A process for converting UF.sub.6 to a solid uranium compound such as UO.sub.2 and CaF. The UF.sub.6 vapor form is contacted with an aqueous solution of NH.sub.4 OH at a pH greater than 7 to precipitate at least some solid uranium values as a solid leaving an aqueous solution containing NH.sub.4 OH and NH.sub.4 F and remaining uranium values. The solid uranium values are separated from the aqueous solution of NH.sub.4 OH and NH.sub.4 F and remaining uranium values which is then diluted with additional water precipitating more uranium values as a solid leaving trace quantities of uranium in a dilute aqueous solution. The dilute aqueous solution is contacted with an ion-exchange resin to remove substantially all the uranium values from the dilute aqueous solution. The dilute solution being contacted with Ca(OH).sub.2 to precipitate CaF.sub.2 leaving dilute NH.sub.4 OH.

  2. Use of ligand-modified micellar-enhanced ultrafiltration to selectively separate copper ions from wastewater streams

    SciTech Connect

    Shadizadeh, S.B.

    1992-12-31

    The selective removal of target ions from an aqueous solution containing ions of like charge by ligand-modified micellar-enhanced ultrafiltration (LM-MEUF), is presented. In LM-MEUF, surfactant and specially tailored ligand are added to the contaminated stream. The surfactant forms aggregates called micelles, the hydrocarbon core of which the ligand complexed with the target species will solubilize. The surfactant is chosen to have the same charge type as the target ion; therefore, other ions (with similar charge) will not associate with the micelle, which makes the separation of the target ion selective. The solution is then processed by ultrafiltration, using a membrane with pore size small enough to block the passage of the micelles. In this study the divalent copper is the target ion in the solution containing divalent calcium. The surfactant is cetylpyridinium chloride (CPC) and the ligand is 4-hexadecyloxybenzyliminodiacetic acid (C{sub 16}BIDA). Experiments were conducted with batch stirred cells and the results have been compared to separation that take place under a variety of conditions in the LM-MEUF process. Rejections of copper of up to 99.8% are observed, with almost no rejection of calcium, showing that LM-MEUF has excellent selectivity and separation efficiency.

  3. Selective separation and purification of highly polar basic compounds using a silica-based strong cation exchange stationary phase.

    PubMed

    Long, Zhen; Guo, Zhimou; Xue, Xingya; Zhang, Xiuli; Nordahl, Lilly; Liang, Xinmiao

    2013-12-01

    Compared to moderately and weakly hydrophilic bases, highly polar basic compounds are even more difficult to separate due to their poor retention in reversed phase (RP) mode. This study described the successful applications of a strong cation exchange (SCX) stationary phase to achieve symmetric peak shape, adequate retention and selectivity in the separation of very polar basic compounds. Salt and acetonitrile concentrations were adjusted to optimize the separation. Good correlations (R(2)=0.998-1.000) between the logarithm of the retention factor and the logarithm of salt or acetonitrile concentration were obtained. Gradients generated by changing salt or acetonitrile concentration were compared for the analysis of different highly polar bases. Although all of the analytes were eluted more quickly with an acetonitrile gradient, the effect of the gradients tested on peak width and peak shape varied with respect to analyte. In addition, the effects of different types of cation and anion additives were also investigated. After separation parameters were acquired, the SCX-based method was utilized to analyze highly hydrophilic alkaloids from Scopolia tangutica Maxim with high separation efficiency (plate numbers>32,000 m(-1)). Concurrently, one very polar alkaloid fraction was purified with symmetric peak shape using the current method. Our results suggest that SCX stationary phase can be used as an alternative to RP stationary phase in the analysis and purification of highly hydrophilic basic compounds. PMID:24267097

  4. Separation of eight selected flavan-3-ols on cellulose thin-layer chromatographic plates.

    PubMed

    Vovk, Irena; Simonovska, Breda; Vuorela, Heikki

    2005-06-10

    The potential of microcristaline cellulose as sorbent in the separation of eight compounds: (+)-catechin (C), (-)-epicatechin (EC), (-)-gallocatechin (GC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg), (-)-epigallocatechin gallate (EGCg), procyanidin B1 and procyanidin B2 was studied. Cellulose HPTLC plates prewashed in water (not necessary, when water was used as developing solvent) and dried with a hair dryer, bandwise application and development in horizontal developing chamber (sandwich configuration) gave the best results. Detection was performed using vanillin-H3PO4 reagent. Four new developing solvent systems were proposed: water, 1-propanol-water (20:80, v/v), 1-propanol-water-acetic acid (4:2:1, v/v) and 1-propanol-water-acetic acid (20:80:1, v/v), and at least two of them were needed for the differentiation between all eight compounds. Surprisingly, water enabled the separation of epimers C from EC and GC from EGC, as well as the dimers procianidin B1 and B2. Additionally, C, EGC, B1 and B2 were separated from all the other compounds. The best choice for developing solvent is given for each of the studied compounds. The best separation of the five main catechins (EC, GC, EGC, ECg, EGCg) present in green tea extract was achieved using 1-propanol-water-acetic acid (20:80:1, v/v). The chromatograms of oak bark extract developed in solvents with higher water content (1-propanol-water (1:4, v/v) and 1-propanol-water-acetic acid (20:80:1, v/v)) showed less bands than chromatograms developed in solvents with higher organic modifier content (e.g. 1-propanol-water-acetic acid (4:2:1, v/v)). It was proved that such behavior was due to the presence of procyanidins beside the main component catechin.

  5. SEPARATION OF PLUTONIUM VALUES FROM OTHER METAL VALUES IN AQUEOUS SOLUTIONS BY SELECTIVE COMPLEXING AND ADSORPTION

    DOEpatents

    Beaton, R.H.

    1960-06-28

    A process is given for separating tri- or tetravalent plutonium from fission products in an aqueous solution by complexing the fission products with oxalate, tannate, citrate, or tartrate anions at a pH value of at least 2.4 (preferably between 2.4 and 4), and contacting a cation exchange resin with the solution whereby the plutonium is adsorbed while the complexed fission products remain in solution.

  6. Determination of uranium in zircon

    USGS Publications Warehouse

    Cuttitta, F.; Daniels, G.J.

    1959-01-01

    A routine fluorimetric procedure is described for the determination of trace amounts of uranium in zircon. It employs the direct extraction of uranyl nitrate with ethyl acetate using phosphate as a retainer for zirconium. Submicrogram amounts or uranium are separated in the presence of 100,000 times the amount of zirconium. The modified procedure has been worked out using synthetic mixtures of known composition and zircon. Results of analyses have an accuracy of 97-98% of the contained uranium and a standard deviation of less than 2.5%. ?? 1959.

  7. Corrosion-resistant uranium

    DOEpatents

    Hovis, V.M. Jr.; Pullen, W.C.; Kollie, T.G.; Bell, R.T.

    1981-10-21

    The present invention is directed to the protecting of uranium and uranium alloy articles from corrosion by providing the surfaces of the articles with a layer of an ion-plated metal selected from aluminum and zinc to a thickness of at least 60 microinches and then converting at least the outer surface of the ion-plated layer of aluminum or zinc to aluminum chromate or zinc chromate. This conversion of the aluminum or zinc to the chromate form considerably enhances the corrosion resistance of the ion plating so as to effectively protect the coated article from corrosion.

  8. Corrosion-resistant uranium

    DOEpatents

    Hovis, Jr., Victor M.; Pullen, William C.; Kollie, Thomas G.; Bell, Richard T.

    1983-01-01

    The present invention is directed to the protecting of uranium and uranium alloy articles from corrosion by providing the surfaces of the articles with a layer of an ion-plated metal selected from aluminum and zinc to a thickness of at least 60 microinches and then converting at least the outer surface of the ion-plated layer of aluminum or zinc to aluminum chromate or zinc chromate. This conversion of the aluminum or zinc to the chromate form considerably enhances the corrosion resistance of the ion plating so as to effectively protect the coated article from corrosion.

  9. Neutron-rich isotope production using a uranium carbide - carbon nanotubes SPES target prototype

    NASA Astrophysics Data System (ADS)

    Corradetti, S.; Biasetto, L.; Manzolaro, M.; Scarpa, D.; Carturan, S.; Andrighetto, A.; Prete, G.; Vasquez, J.; Zanonato, P.; Colombo, P.; Jost, C. U.; Stracener, D. W.

    2013-05-01

    The SPES (Selective Production of Exotic Species) project, under development at the Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Legnaro (INFN-LNL), is a new-generation Isotope Separation On-Line (ISOL) facility for the production of radioactive ion beams by means of the proton-induced fission of uranium. In the framework of the research on the SPES target, seven uranium carbide discs, obtained by reacting uranium oxide with graphite and carbon nanotubes, were irradiated with protons at the Holifield Radioactive Ion Beam Facility (HRIBF) of Oak Ridge National Laboratory (ORNL). In the following, the yields of several fission products obtained during the experiment are presented and discussed. The experimental results are then compared to those obtained using a standard uranium carbide target. The reported data highlights the capability of the new type of SPES target to produce and release isotopes of interest for the nuclear physics community.

  10. Neutron-Rich Isotope Production Using a Uranium Carbide Carbon Nanotubes SPES Target Prototype

    SciTech Connect

    Corradetti, Stefano; Biasetto, Lisa; Manzolaro, Mattia; Scarpa, Daniele; Carturan, S.; Andrighetto, Alberto; Prete, Gianfranco; Vasquez, Jose L; Zanonato, P.; Colombo, P.; Jost, Carola; Stracener, Daniel W

    2013-01-01

    The SPES (Selective Production of Exotic Species) project, under development at the Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Legnaro (INFN-LNL), is a new-generation Isotope Separation On-Line (ISOL) facility for the production of radioactive ion beams by means of the proton-induced fission of uranium. In the framework of the research on the SPES target, seven uranium carbide discs, obtained by reacting uranium oxide with graphite and carbon nanotubes, were irradiated with protons at the Holifield Radioactive Ion Beam Facility (HRIBF) of Oak Ridge National Laboratory (ORNL). In the following, the yields of several fission products obtained during the experiment are presented and discussed. The experimental results are then compared to those obtained using a standard uranium carbide target. The reported data highlights the capability of the new type of SPES target to produce and release isotopes of interest for the nuclear physics community.

  11. Synthesis and extraction studies with a rationally designed diamide ligand selective to actinide(iv) pertinent to the plutonium uranium redox extraction process.

    PubMed

    Sharma, Shikha; Panja, Surajit; Bhattacharyya, Arunasis; Dhami, Prem S; Gandhi, Preetam M; Ghosh, Sunil K

    2016-05-01

    A new class of conformationally constrained oxa-bridged tricyclo-dicarboxamide (OTDA) ligand was rationally designed for the selective extraction of tetravalent actinides pertinent to the Plutonium Uranium Redox EXtraction (PUREX) process. Two of the designed diamide ligands were synthesized and extraction studies were performed for Pu(iv) from HNO3 medium. The mechanism of extraction was investigated by studying various parameters such as feed HNO3, NaNO3 and OTDA concentrations. The nature of the extracted species was found to be [Pu(NO3)4(OTDA)]. One of the OTDA ligands was elaborately tested and showed the selective extraction of Pu(iv) and Np(iv) over other actinide species, viz., U(vi), Np(v), Am(iii), lanthanides and fission products contained in a nuclear waste from the PUREX process. DFT calculations predicted the charge density on each of the coordinating 'O' atoms of OTDA supporting its high Pu(iv) selectivity over other ions studied and also provided the energy optimized structure of OTDA and its Pu(iv) complex. PMID:27054892

  12. Lignin-based microporous materials as selective adsorbents for carbon dioxide separation.

    PubMed

    Meng, Qing Bo; Weber, Jens

    2014-12-01

    Suitable solid adsorbents are demanded for carbon capture and storage (CCS) processes. In this work, a novel microporous polymer is developed by hypercrosslinking of organosolv lignin, which is a renewable resource. Reaction with formaldehyde dimethyl acetal (FDA) via Friedel-Crafts reaction gives microporous networks, with moderate capacity of carbon dioxide but excellent selectivity towards CO2 /N2 mixture as predicted on the basis of ideal adsorption-solution theory (IAST). Pyrolysis of pure organosolv lignin results in microporous carbon powders, while pyrolysis of hypercrosslinked organosolv lignin yields shape-persistent materials with increased CO2 capacity while maintaining very good selectivity.

  13. Reactive Separations via a Hydrothermally Stable Hydrogen Selective Membrane. Final Report

    SciTech Connect

    Ciora, R. J.; Liu, P. KT.

    2002-10-29

    In this SBIR Phase I program, we have successfully completed the fabrication of SiC-based hydrogen selective membranes suitable for use as a membrane reactor for steam-methane reforming applications. Hydrothermal stability was performed for selected membrane to demonstrate their stability for appx. 50 hours under the proposed reforming condition. In addition, several mechanistic study was conducted to elucidate the SiC membrane formation mechanism. This understanding will facilitate membrane optimization work to be proposed for the Phase II study. The reaction study was postponed to the Phase II study.

  14. Selective Separation of Trivalent Actinides from Lanthanides by Aqueous Processing with Introduction of Soft Donor Atoms

    SciTech Connect

    Kenneth L. Nash

    2009-09-22

    Implementation of a closed loop nuclear fuel cycle requires the utilization of Pu-containing MOX fuels with the important side effect of increased production of the transplutonium actinides, most importantly isotopes of Am and Cm. Because the presence of these isotopes significantly impacts the long-term radiotoxicity of high level waste, it is important that effective methods for their isolation and/or transmutation be developed. Furthermore, since transmutation is most efficiently done in the absence of lanthanide fission products (high yield species with large thermal neutron absorption cross sections) it is important to have efficient procedures for the mutual separation of Am and Cm from the lanthanides. The chemistries of these elements are nearly identical, differing only in the slightly stronger strength of interaction of trivalent actinides with ligand donor atoms softer than O (N, Cl-, S). Research being conducted around the world has led to the development of new reagents and processes with considerable potential for this task. However, pilot scale testing of these reagents and processes has demonstrated the susceptibility of the new classes of reagents to radiolytic and hydrolytic degradation. In this project, separations of trivalent actinides from fission product lanthanides have been investigated in studies of 1) the extraction and chemical stability properties of a class of soft-donor extractants that are adapted from water-soluble analogs, 2) the application of water soluble soft-donor complexing agents in tandem with conventional extractant molecules emphasizing fundamental studies of the TALSPEAK Process. This research was conducted principally in radiochemistry laboratories at Washington State University. Collaborators at the Radiological Processing Laboratory (RPL) at the Pacific Northwest National Laboratory (PNNL) have contributed their unique facilities and capabilities, and have supported student internships at PNNL to broaden their

  15. Magnetically separable polymer (Mag-MIP) for selective analysis of biotin in food samples.

    PubMed

    Uzuriaga-Sánchez, Rosario Josefina; Khan, Sabir; Wong, Ademar; Picasso, Gino; Pividori, Maria Isabel; Sotomayor, Maria Del Pilar Taboada

    2016-01-01

    This work presents an efficient method for the preparation of magnetic nanoparticles modified with molecularly imprinted polymers (Mag-MIP) through core-shell method for the determination of biotin in milk food samples. The functional monomer acrylic acid was selected from molecular modeling, EGDMA was used as cross-linking monomer and AIBN as radical initiator. The Mag-MIP and Mag-NIP were characterized by FTIR, magnetic hysteresis, XRD, SEM and N2-sorption measurements. The capacity of Mag-MIP for biotin adsorption, its kinetics and selectivity were studied in detail. The adsorption data was well described by Freundlich isotherm model with adsorption equilibrium constant (KF) of 1.46 mL g(-1). The selectivity experiments revealed that prepared Mag-MIP had higher selectivity toward biotin compared to other molecules with different chemical structure. The material was successfully applied for the determination of biotin in diverse milk samples using HPLC for quantification of the analyte, obtaining the mean value of 87.4% recovery.

  16. Ion Selective Ceramics for Waste Separations. Input for Annual Accomplishments Report

    SciTech Connect

    Spoerke, Erik David

    2015-10-01

    This report discusses“Ion-Selective Ceramics for Waste Separations” which aims to develop an electrochemical approach to remove fission product waste (e.g., Cs+ ) from the LiCl-KCl molten salts used in the pyroprocessing of spent nuclear fuel.

  17. Control of selectivity via nanochemistry: monolithic capillary column containing hydroxyapatite nanoparticles for separation of proteins and enrichment of phosphopeptides.

    PubMed

    Krenkova, Jana; Lacher, Nathan A; Svec, Frantisek

    2010-10-01

    New monolithic capillary columns with embedded commercial hydroxyapatite nanoparticles have been developed and used for protein separation and selective enrichment of phosphopeptides. The rod-shaped hydroxyapatite nanoparticles were incorporated into the poly(2-hydroxyethyl methacrylate-co-ethylene dimethacrylate) monolith by simply admixing them in the polymerization mixture followed by in situ polymerization. The effect of percentages of monomers and hydroxyapatite nanoparticles in the polymerization mixture on the performance of the monolithic column was explored in detail. We found that the loading capacity of the monolith is on par with other hydroxyapatite separation media. However, the speed at which these columns can be used is higher due to the fast mass transport. The function of the monolithic columns was demonstrated with the separations of a model mixture of proteins including ovalbumin, myoglobin, lysozyme, and cytochrome c as well as a monoclonal antibody and its aggregates with protein A. Selective enrichment and MALDI/MS characterization of phosphopeptides fished-out from complex peptide mixtures of ovalbumin, α-casein, and β-casein digests were also achieved using the hydroxyapatite monolith.

  18. The product composition regions of azeotropic distillation columns. 2. Separability in two-feed columns and entrainer selection

    SciTech Connect

    Wahnschafft, O.M.; Westerberg, A.W. . Engineering Design Research Center and Department of Chemical Engineering)

    1993-06-01

    A method to assess the product composition regions for distillation of ternary mixtures in single-feed distillation columns, introduced in the first paper of this series, is generalized to account for the effect of introducing multiple feeds of different trays. The method relies on so-called fixed point curves which are trajectories in the compositions space. These trajectories describe the possible compositions of pinch points in each column section as functions of the energy supplied to a column, i.e., for all conceivable values of the reflux ratio. Pinch point trajectories may be determined analytically or, for ternary mixtures, can be located graphically using residue curve maps. The authors carry out a mostly graphical analysis, using pinch point trajectories to establish separation feasibility ahead of design calculations. This analysis also provides information on the minimum entrainer supply for a specified separation and visualizes the phenomenon of the occurrence of a maximum reflux ratio for separation in a column with a separate, extractive agent feed. The analysis is analogous to that for single-feed columns, only the critical pinch trajectories may be those for the extractive column section between the feeds. This analogy suggests the notion of a generalized extractive distillation process, for which new entrainer selection criteria are proposed.

  19. JACKETING URANIUM

    DOEpatents

    Saller, H.A.; Keeler, J.R.

    1959-07-14

    The bonding to uranium of sheathing of iron or cobalt, or nickel, or alloys thereof is described. The bonding is accomplished by electro-depositing both surfaces to be joined with a coating of silver and amalgamating or alloying the silver layer with mercury or indium. Then the silver alloy is homogenized by exerting pressure on an assembly of the uranium core and the metal jacket, reducing the area of assembly and heating the assembly to homogenize by diffusion.

  20. Isotope separation by laser means

    DOEpatents

    Robinson, C. Paul; Jensen, Reed J.; Cotter, Theodore P.; Greiner, Norman R.; Boyer, Keith

    1982-06-15

    A process for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium and plutonium.

  1. REMOVAL OF URANIUM FROM ORGANIC LIQUIDS

    DOEpatents

    Vavalides, S.P.

    1959-08-25

    A process is described for recovering small quantities of uranium from organic liquids such as hydrocarbon oils. halogen-substituted hydrocarbons, and alcohols. The organic liquid is contacted with a comminuted alkaline earth hydroxide, calcium hydroxide particularly, and the resulting uranium-bearing solid is separated from the liquid by filtration. Uranium may then be recovered from the solid by means of dissolution in nitric acid and conventional extraction with an organic solvent such as tributyl phosphate.

  2. Selective interfacial synthesis of metal-organic frameworks on a polybenzimidazole hollow fiber membrane for gas separation.

    PubMed

    Biswal, Bishnu P; Bhaskar, Anand; Banerjee, Rahul; Kharul, Ulhas K

    2015-04-28

    Metal-organic frameworks (MOFs) have gained immense attention as new age materials due to their tuneable properties and diverse applicability. However, efforts on developing promising materials for membrane based gas separation, and control over the crystal growth positions on polymeric hollow fiber membranes still remain key challenges. In this investigation, a new, convenient and scalable room temperature interfacial method for growing MOFs (ZIF-8 and CuBTC) on either the outer or inner side of a polybenzimidazole based hollow fiber (PBI-BuI-HF) membrane surface has been achieved in a controlled manner. This was made possible by the appropriate selection of an immiscible solvent pair and the synthetic conditions. The growth of MOFs on the PBI-BuI-HF membrane by the interfacial method was continuous and showed an appreciable gas separation performance, conveying promise for their applicability.

  3. Selective Extraction and Effective Separation of Galactosylsphingosine (Psychosine) and Glucosylsphingosine from Other Glycosphingolipids in Pathological Tissue Samples

    PubMed Central

    Li, Su-Chen; Buck, Wayne R.; Haskins, Mark E.; Wu, Sz-Wei; Khoo, Kay-Hooi; Sidransky, Ellen; Bunnell, Bruce A.

    2012-01-01

    To facilitate the study of the chemical pathology of galactosylsphingosine (psychosine, GalSph) in Krabbe disease and glucosylsphingosine (GlcSph) in Gaucher disease, we have devised a facile method for the effective separation of these two glycosylsphingosines from other glycosphingolipids (GSLs) in Krabbe brain and Gaucher spleen samples. The procedure involves the use of acetone to selectively extract GalSph and GlcSph, respectively, from Krabbe brain and Gaucher spleen samples. Since acetone does not extract other GSLs except modest amounts of galactosylceramide, sulfatide, and glucosylceramide, the positively charged GalSph or GlcSph in the acetone extract can be readily separated from other GSLs by batchwise cation-exchange chromatography using a Waters Accell Plus CM Cartridge. GalSph or GlcSph enriched by this simple procedure can be readily analyzed by thin-layer chromatography or high-performance liquid chromatography. PMID:21136152

  4. Ion imprinted polymeric nanoparticles for selective separation and sensitive determination of zinc ions in different matrices.

    PubMed

    Shamsipur, Mojtaba; Rajabi, Hamid Reza; Pourmortazavi, Seied Mahdi; Roushani, Mahmoud

    2014-01-01

    Preparation of Zn(2+) ion-imprinted polymer (Zn-IIP) nanoparticles is presented in this report. The Zn-IIP nanoparticles are prepared by dissolving stoichiometric amounts of zinc nitrate and selected chelating ligand, 3,5,7,20,40-pentahydroxyflavone, in 15 mL ethanol-acetonitrile (2:1; v/v) mixture as a porogen solvent in the presence of ethylene glycol-dimethacrylate (EGDMA) as cross-linking, methacrylic acid (MAA) as functional monomer, and 2,2-azobisisobutyronitrile (AIBN) as initiator. After polymerization, Cavities in the polymer particles corresponding to the Zn(2+) ions were created by leaching the polymer in HCl aqueous solution. The synthesized IIPs were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, fluorescence spectroscopy and thermal analysis techniques. Also, the pH range for rebinding of Zn(2+) ion on the IIP and equilibrium binding time were optimized, using flame atomic absorption spectrometry. In selectivity study, it was found that imprinting results increased affinity of the material toward Zn(2+) ion over other competitor metal ions with the same charge and close ionic radius. The prepared IIPs were repeatedly used and regenerated for six times without any significant decrease in polymer binding affinities. Finally, the prepared sorbent was successfully applied to the selective recognition and determination of zinc ion in different real samples.

  5. Metal-organic framework with optimally selective xenon adsorption and separation.

    PubMed

    Banerjee, Debasis; Simon, Cory M; Plonka, Anna M; Motkuri, Radha K; Liu, Jian; Chen, Xianyin; Smit, Berend; Parise, John B; Haranczyk, Maciej; Thallapally, Praveen K

    2016-01-01

    Nuclear energy is among the most viable alternatives to our current fossil fuel-based energy economy. The mass deployment of nuclear energy as a low-emissions source requires the reprocessing of used nuclear fuel to recover fissile materials and mitigate radioactive waste. A major concern with reprocessing used nuclear fuel is the release of volatile radionuclides such as xenon and krypton that evolve into reprocessing facility off-gas in parts per million concentrations. The existing technology to remove these radioactive noble gases is a costly cryogenic distillation; alternatively, porous materials such as metal-organic frameworks have demonstrated the ability to selectively adsorb xenon and krypton at ambient conditions. Here we carry out a high-throughput computational screening of large databases of metal-organic frameworks and identify SBMOF-1 as the most selective for xenon. We affirm this prediction and report that SBMOF-1 exhibits by far the highest reported xenon adsorption capacity and a remarkable Xe/Kr selectivity under conditions pertinent to nuclear fuel reprocessing. PMID:27291101

  6. Metal–organic framework with optimally selective xenon adsorption and separation

    PubMed Central

    Banerjee, Debasis; Simon, Cory M.; Plonka, Anna M.; Motkuri, Radha K.; Liu, Jian; Chen, Xianyin; Smit, Berend; Parise, John B.; Haranczyk, Maciej; Thallapally, Praveen K.

    2016-01-01

    Nuclear energy is among the most viable alternatives to our current fossil fuel-based energy economy. The mass deployment of nuclear energy as a low-emissions source requires the reprocessing of used nuclear fuel to recover fissile materials and mitigate radioactive waste. A major concern with reprocessing used nuclear fuel is the release of volatile radionuclides such as xenon and krypton that evolve into reprocessing facility off-gas in parts per million concentrations. The existing technology to remove these radioactive noble gases is a costly cryogenic distillation; alternatively, porous materials such as metal–organic frameworks have demonstrated the ability to selectively adsorb xenon and krypton at ambient conditions. Here we carry out a high-throughput computational screening of large databases of metal–organic frameworks and identify SBMOF-1 as the most selective for xenon. We affirm this prediction and report that SBMOF-1 exhibits by far the highest reported xenon adsorption capacity and a remarkable Xe/Kr selectivity under conditions pertinent to nuclear fuel reprocessing. PMID:27291101

  7. Study of selective heating at ion cyclotron resonance for the plasma separation process

    NASA Astrophysics Data System (ADS)

    Compant La Fontaine, A.; Pashkovsky, V. G.

    1995-12-01

    The plasma separation process by ion cyclotron resonance heating (ICRH) is studied both theoretically and experimentally on two devices: the first one called ERIC (Ion Cyclotron Resonance Experiment) at Saclay (France) [P. Louvet, Proceedings of the 2nd Workshop on Separation Phenomena in Liquids and Gases, Versailles, France, 1989, edited by P. Louvet, P. Noe, and Soubbaramayer (Centre d'Etudes Nucléaires de Saclay and Cité Scientifique Parcs et Technopoles, Ile de France Sud, France, 1989), Vol. 1, p. 5] and the other one named SIRENA at the Kurchatov Institute, Moscow, Russia [A. I. Karchevskii et al., Plasma Phys. Rep. 19, 214 (1993)]. The radio frequency (RF) transversal magnetic field is measured by a magnetic probe both in plasma and vacuum and its Fourier spectrum versus the axial wave number kz is obtained. These results are in agreement with the electromagnetic (EM) field calculation model based on resolution of Maxwell equations by a time-harmonic scheme studied here. Various axial boundary conditions models used to compute the EM field are considered. The RF magnetic field is weakly influenced by the plasma while the electric field components are strongly disturbed due to space-charge effects. In the plasma the transversal electric field is enhanced and the kz spectrum is narrower than in vacuum. The calculation of the resonant isotope heating is made by the Runge-Kutta method. The influence of ion-ion collisions, inhomogeneity of the static magnetic field B0, and the RF transversal magnetic field component on the ion acceleration is examined. These results are successfully compared with experiments of a minor isotope 44Ca heating measurements, made with an energy analyzer.

  8. Study of selective heating at ion cyclotron resonance for the plasma separation process

    SciTech Connect

    Compant La Fontaine, A.

    1995-12-01

    The plasma separation process by ion cyclotron resonance heating (ICRH) is studied both theoretically and experimentally on two devices: the first one called ERIC (Ion Cyclotron Resonance Experiment) at Saclay (France) [P. Louvet, {ital Proceedings} {ital of} {ital the} 2{ital nd} {ital Workshop} {ital on} {ital Separation} {ital Phenomena} {ital in} {ital Liquids} {ital and} {ital Gases}, Versailles, France, 1989, edited by P. Louvet, P. Noe, and Soubbaramayer (Centre d`Etudes Nucleaires de Saclay and Cite Scientifique Parcs et Technopoles, Ile de France Sud, France, 1989), Vol. 1, p. 5] and the other one named SIRENA at the Kurchatov Institute, Moscow, Russia [A. I. Karchevskii {ital et} {ital al}., Plasma Phys. Rep. {bold 19}, 214 (1993)]. The radio frequency (RF) transversal magnetic field is measured by a magnetic probe both in plasma and vacuum and its Fourier spectrum versus the axial wave number {ital k}{sub {ital z}} is obtained. These results are in agreement with the electromagnetic (EM) field calculation model based on resolution of Maxwell equations by a time-harmonic scheme studied here. Various axial boundary conditions models used to compute the EM field are considered. The RF magnetic field is weakly influenced by the plasma while the electric field components are strongly disturbed due to space-charge effects. In the plasma the transversal electric field is enhanced and the {ital k}{sub {ital z}} spectrum is narrower than in vacuum. The calculation of the resonant isotope heating is made by the Runge--Kutta method. The influence of ion--ion collisions, inhomogeneity of the static magnetic field {ital B}{sub 0}, and the RF transversal magnetic field component on the ion acceleration is examined. These results are successfully compared with experiments of a minor isotope {sup 44}Ca heating measurements, made with an energy analyzer. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  9. Preparation and characterization of superparamagnetic molecularly imprinted polymers for selective adsorption and separation of vanillin in food samples.

    PubMed

    Ning, Fangjian; Peng, Hailong; Dong, Liling; Zhang, Zhong; Li, Jinhua; Chen, Lingxin; Xiong, Hua

    2014-11-19

    Novel water-compatible superparamagnetic molecularly imprinted polymers (M-MIPs) were prepared by coating superparamagnetic Fe3O4 nanoparticles with MIPs in a methanol-water reaction system. The M-MIPs were used for the selective adsorption and separation of vanillin from aqueous solution. The M-MIPs were characterized by X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), and scanning electron microscopy (SEM). Results indicated that a core-shell structure of M-MIPs was obtained by coating a layer of silica and MIPs on the surface of the Fe3O4 nanoparticles. The obtained M-MIPs possess a loose and porous structure and can be rapidly separated from the solution using a magnet. The adsorption experiments showed that the binding capacity of the M-MIPs was significantly higher than that of the superparamagnetic non-molecularly imprinted polymers (M-NIPs). Meanwhile, the adsorption of M-MIPs reached equilibrium within 100 min, and the apparent maximum adsorption quantity (Qmax) and dissociation constant (Kd) were 64.12 μmol g(-1) and 58.82 μmol L(-1), respectively. The Scatchard analysis showed that homogeneous binding sites were formed on the M-MIP surface. The recoveries of 83.39-95.58% were achieved when M-MIPs were used for the pre-concentration and selective separation of vanillin in spiked food samples. These results provided the possibility for the separation and enrichment of vanillin from complicated food matrices by M-MIPs.

  10. Selective interfacial synthesis of metal-organic frameworks on a polybenzimidazole hollow fiber membrane for gas separation

    NASA Astrophysics Data System (ADS)

    Biswal, Bishnu P.; Bhaskar, Anand; Banerjee, Rahul; Kharul, Ulhas K.

    2015-04-01

    Metal-organic frameworks (MOFs) have gained immense attention as new age materials due to their tuneable properties and diverse applicability. However, efforts on developing promising materials for membrane based gas separation, and control over the crystal growth positions on polymeric hollow fiber membranes still remain key challenges. In this investigation, a new, convenient and scalable room temperature interfacial method for growing MOFs (ZIF-8 and CuBTC) on either the outer or inner side of a polybenzimidazole based hollow fiber (PBI-BuI-HF) membrane surface has been achieved in a controlled manner. This was made possible by the appropriate selection of an immiscible solvent pair and the synthetic conditions. The growth of MOFs on the PBI-BuI-HF membrane by the interfacial method was continuous and showed an appreciable gas separation performance, conveying promise for their applicability.Metal-organic frameworks (MOFs) have gained immense attention as new age materials due to their tuneable properties and diverse applicability. However, efforts on developing promising materials for membrane based gas separation, and control over the crystal growth positions on polymeric hollow fiber membranes still remain key challenges. In this investigation, a new, convenient and scalable room temperature interfacial method for growing MOFs (ZIF-8 and CuBTC) on either the outer or inner side of a polybenzimidazole based hollow fiber (PBI-BuI-HF) membrane surface has been achieved in a controlled manner. This was made possible by the appropriate selection of an immiscible solvent pair and the synthetic conditions. The growth of MOFs on the PBI-BuI-HF membrane by the interfacial method was continuous and showed an appreciable gas separation performance, conveying promise for their applicability. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr00299k

  11. Preparation and characterization of superparamagnetic molecularly imprinted polymers for selective adsorption and separation of vanillin in food samples.

    PubMed

    Ning, Fangjian; Peng, Hailong; Dong, Liling; Zhang, Zhong; Li, Jinhua; Chen, Lingxin; Xiong, Hua

    2014-11-19

    Novel water-compatible superparamagnetic molecularly imprinted polymers (M-MIPs) were prepared by coating superparamagnetic Fe3O4 nanoparticles with MIPs in a methanol-water reaction system. The M-MIPs were used for the selective adsorption and separation of vanillin from aqueous solution. The M-MIPs were characterized by X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), and scanning electron microscopy (SEM). Results indicated that a core-shell structure of M-MIPs was obtained by coating a layer of silica and MIPs on the surface of the Fe3O4 nanoparticles. The obtained M-MIPs possess a loose and porous structure and can be rapidly separated from the solution using a magnet. The adsorption experiments showed that the binding capacity of the M-MIPs was significantly higher than that of the superparamagnetic non-molecularly imprinted polymers (M-NIPs). Meanwhile, the adsorption of M-MIPs reached equilibrium within 100 min, and the apparent maximum adsorption quantity (Qmax) and dissociation constant (Kd) were 64.12 μmol g(-1) and 58.82 μmol L(-1), respectively. The Scatchard analysis showed that homogeneous binding sites were formed on the M-MIP surface. The recoveries of 83.39-95.58% were achieved when M-MIPs were used for the pre-concentration and selective separation of vanillin in spiked food samples. These results provided the possibility for the separation and enrichment of vanillin from complicated food matrices by M-MIPs. PMID:25352428

  12. Smart thorium and uranium determination exploiting renewable solid-phase extraction applied to environmental samples in a wide concentration range.

    PubMed

    Avivar, Jessica; Ferrer, Laura; Casas, Montserrat; Cerdà, Víctor

    2011-07-01

    A smart fully automated system is proposed for determination of thorium and uranium in a wide concentration range, reaching environmental levels. The hyphenation of lab-on-valve (LOV) and multisyringe flow injection analysis (MSFIA), coupled to a long path length liquid waveguide capillary cell, allows the spectrophotometric determination of thorium and uranium in different types of environmental sample matrices achieving high selectivity and sensitivity levels. Online separation and preconcentration of thorium and uranium is carried out by means of Uranium and TEtraValents Actinides resin. The potential of the LOV-MSFIA makes possible the full automation of the system by the in-line regeneration of the column and its combination with a smart methodology is a step forward in automation. After elution, thorium(IV) and uranium(VI) are spectrophotometrically detected after reaction with arsenazo-III. We propose a rapid, inexpensive, and fully automated method to determine thorium(IV) and uranium(VI) in a wide concentration range (0-1,200 and 0-2,000 μg L(-1) Th and U, respectively). Limits of detection reached are 5.9 ηg L(-1) of uranium and 60 ηg L(-1) of thorium. Different water sample matrices (seawater, well water, freshwater, tap water, and mineral water), and a channel sediment reference material which contained thorium and uranium were satisfactorily analyzed with the proposed method. PMID:21573729

  13. Smart thorium and uranium determination exploiting renewable solid-phase extraction applied to environmental samples in a wide concentration range.

    PubMed

    Avivar, Jessica; Ferrer, Laura; Casas, Montserrat; Cerdà, Víctor

    2011-07-01

    A smart fully automated system is proposed for determination of thorium and uranium in a wide concentration range, reaching environmental levels. The hyphenation of lab-on-valve (LOV) and multisyringe flow injection analysis (MSFIA), coupled to a long path length liquid waveguide capillary cell, allows the spectrophotometric determination of thorium and uranium in different types of environmental sample matrices achieving high selectivity and sensitivity levels. Online separation and preconcentration of thorium and uranium is carried out by means of Uranium and TEtraValents Actinides resin. The potential of the LOV-MSFIA makes possible the full automation of the system by the in-line regeneration of the column and its combination with a smart methodology is a step forward in automation. After elution, thorium(IV) and uranium(VI) are spectrophotometrically detected after reaction with arsenazo-III. We propose a rapid, inexpensive, and fully automated method to determine thorium(IV) and uranium(VI) in a wide concentration range (0-1,200 and 0-2,000 μg L(-1) Th and U, respectively). Limits of detection reached are 5.9 ηg L(-1) of uranium and 60 ηg L(-1) of thorium. Different water sample matrices (seawater, well water, freshwater, tap water, and mineral water), and a channel sediment reference material which contained thorium and uranium were satisfactorily analyzed with the proposed method.

  14. Separation of rare gases and chiral molecules by selective binding in porous organic cages

    SciTech Connect

    Chen, Linjiang; Reiss, Paul S.; Chong, Samantha Y.; Holden, Daniel; Jelfs, Kim E.; Hasell, Tom; Little, Marc A.; Kewley, Adam; Briggs, Michael E.; Stephenson, Andrew; Thomas, K. M.; Armstrong, Jayne A.; Bell, Jon; Busto, Jose; Noel, Raymond; Liu, Jian; Strachan, Denis M.; Thallapally, Praveen K.; Cooper, Andrew I.

    2014-10-31

    Abstract: The rare gases krypton, xenon, and radon pose both an economic opportunity and a potential environmental hazard. Xenon is used in commercial lighting, medical imaging, and anesthesia, and can sell for $5,000 per kilogram. Radon, by contrast, Is naturally radioactive and the second largest cause of lung cancer, and radioactive xenon, 133Xe, was a major pollutant released In the Fukushima Daiichi Nuclear Power Plant disaster. We describe an organic cage molecule that can capture xenon and radon with unprecedented selectivity, suggesting new technologies for environmental monitoring, removal of pollutants, or the recovery of rare, valuable elements from air.

  15. URANIUM DECONTAMINATION WITH RESPECT TO ZIRCONIUM

    DOEpatents

    Vogler, S.; Beederman, M.

    1961-05-01

    A process is given for separating uranium values from a nitric acid aqueous solution containing uranyl values, zirconium values and tetravalent plutonium values. The process comprises contacting said solution with a substantially water-immiscible liquid organic solvent containing alkyl phosphate, separating an organic extract phase containing the uranium, zirconium, and tetravalent plutonium values from an aqueous raffinate, contacting said organic extract phase with an aqueous solution 2M to 7M in nitric acid and also containing an oxalate ion-containing substance, and separating a uranium- containing organic raffinate from aqueous zirconium- and plutonium-containing extract phase.

  16. Costs of antibiotic resistance – separating trait effects and selective effects

    PubMed Central

    Hall, Alex R; Angst, Daniel C; Schiessl, Konstanze T; Ackermann, Martin

    2015-01-01

    Antibiotic resistance can impair bacterial growth or competitive ability in the absence of antibiotics, frequently referred to as a ‘cost’ of resistance. Theory and experiments emphasize the importance of such effects for the distribution of resistance in pathogenic populations. However, recent work shows that costs of resistance are highly variable depending on environmental factors such as nutrient supply and population structure, as well as genetic factors including the mechanism of resistance and genetic background. Here, we suggest that such variation can be better understood by distinguishing between the effects of resistance mechanisms on individual traits such as growth rate or yield (‘trait effects’) and effects on genotype frequencies over time (‘selective effects’). We first give a brief overview of the biological basis of costs of resistance and how trait effects may translate to selective effects in different environmental conditions. We then review empirical evidence of genetic and environmental variation of both types of effects and how such variation may be understood by combining molecular microbiological information with concepts from evolution and ecology. Ultimately, disentangling different types of costs may permit the identification of interventions that maximize the cost of resistance and therefore accelerate its decline. PMID:25861384

  17. METHOD OF SEPARATING PLUTONIUM

    DOEpatents

    Brown, H.S.; Hill, O.F.

    1958-02-01

    Plutonium hexafluoride is a satisfactory fluorinating agent and may be reacted with various materials capable of forming fluorides, such as copper, iron, zinc, etc., with consequent formation of the metal fluoride and reduction of the plutonium to the form of a lower fluoride. In accordance with the present invention, it has been found that the reactivity of plutonium hexafluoride with other fluoridizable materials is so great that the process may be used as a method of separating plutonium from mixures containing plutonium hexafluoride and other vaporized fluorides even though the plutonium is present in but minute quantities. This process may be carried out by treating a mixture of fluoride vapors comprising plutonium hexafluoride and fluoride of uranium to selectively reduce the plutonium hexafluoride and convert it to a less volatile fluoride, and then recovering said less volatile fluoride from the vapor by condensation.

  18. Selective separation and concentration of antihypertensive peptides from rapeseed protein hydrolysate by electrodialysis with ultrafiltration membranes.

    PubMed

    He, Rong; Girgih, Abraham T; Rozoy, Elodie; Bazinet, Laurent; Ju, Xing-Rong; Aluko, Rotimi E

    2016-04-15

    Rapeseed protein isolate was subjected to alcalase digestion to obtain a protein hydrolysate that was separated into peptide fractions using electrodialysis with ultrafiltration membrane (EDUF) technology. The EDUF process (6h duration) led to isolation of three peptide fractions: anionic (recovered in KCl-1 compartment), cationic (recovered in KCl-2 compartment), and those that remained in the feed compartment, which was labeled final rapeseed protein hydrolysate (FRPH). As expected the KCl-1 peptides were enriched in negatively-charged (43.57%) while KCl-2 contained high contents of positively-charged (28.35%) amino acids. All the samples inhibited angiotensin converting enzyme (ACE) and renin activities in dose-dependent manner with original rapeseed protein hydrolysate having the least ACE-inhibitory IC50 value of 0.0932±0.0037 mg/mL while FRPH and KCl-2 had least renin-inhibitory IC50 values of 0.47±0.05 and 0.55±0.06 mg/mL, respectively. Six hours after oral administration (100 mg/kg body weight) to spontaneously hypertensive rats, the FRPH produced the maximum systolic blood pressure reduction of -51 mmHg.

  19. Selective separation and determination of isoproterenol on thin layers of bismuth silicate ion-exchanger.

    PubMed

    Ghoulipour Vanik; Hassankhani-Majd Zahra

    2015-06-01

    A simple and sensitive method for the separation and determination of isoproterenol from other doping drugs has been developed on thin layers of bismuth silicate, a synthetic inorganic ion exchanger as adsorbent in thin layer chromatography (TLC). A mixture of methanol and 0.1 mol/L formic acid (3:7, v/v) was employed as the mobile phase. The development time was 32 min. The quantitative measurement were performed with a Camag TLC Scanner-3 at wavelength (λ) of 410 nm. The isoproterenol recovery in this procedure was 98.9%. The linear correlation coefficient was greater than 0. 987 1 and the relative standard deviation (RSD) was less than 0.94. The limit of detection (LOD) and limit of quantification ( LOQ) were 7.7 x 10(-7) mol/L and 3.85 x 10(-6) mol/L, respectively. This method has been applied in the determination of isoproterenol in dosage forms and in biological fluids.

  20. URANIUM RECOVERY PROCESS

    DOEpatents

    Hyman, H.H.; Dreher, J.L.

    1959-07-01

    The recovery of uranium from the acidic aqueous metal waste solutions resulting from the bismuth phosphate carrier precipitation of plutonium from solutions of neutron irradiated uranium is described. The waste solutions consist of phosphoric acid, sulfuric acid, and uranium as a uranyl salt, together with salts of the fission products normally associated with neutron irradiated uranium. Generally, the process of the invention involves the partial neutralization of the waste solution with sodium hydroxide, followed by conversion of the solution to a pH 11 by mixing therewith sufficient sodium carbonate. The resultant carbonate-complexed waste is contacted with a titanated silica gel and the adsorbent separated from the aqueous medium. The aqueous solution is then mixed with sufficient acetic acid to bring the pH of the aqueous medium to between 4 and 5, whereby sodium uranyl acetate is precipitated. The precipitate is dissolved in nitric acid and the resulting solution preferably provided with salting out agents. Uranyl nitrate is recovered from the solution by extraction with an ether such as diethyl ether.

  1. ELUTION OF URANIUM FROM RESIN

    DOEpatents

    McLEan, D.C.

    1959-03-10

    A method is described for eluting uranium from anion exchange resins so as to decrease vanadium and iron contamination and permit recycle of the major portion of the eluats after recovery of the uranium. Diminution of vanadium and iron contamination of the major portion of the uranium is accomplished by treating the anion exchange resin, which is saturated with uranium complex by adsorption from a sulfuric acid leach liquor from an ore bearing uranium, vanadium and iron, with one column volume of eluant prepared by passing chlorine into ammonium hydroxide until the chloride content is about 1 N and the pH is about 1. The resin is then eluted with 8 to 9 column volumes of 0.9 N ammonium chloride--0.1 N hydrochloric acid solution. The eluants are collected separately and treated with ammonia to precipitate ammonium diuranate which is filtered therefrom. The uranium salt from the first eluant is contaminated with the major portion of ths vanadium and iron and is reworked, while the uranium recovered from the second eluant is relatively free of the undesirable vanadium and irons. The filtrate from the first eluant portion is discarded. The filtrate from the second eluant portion may be recycled after adding hydrochloric acid to increase the chloride ion concentration and adjust the pH to about 1.

  2. Recent Progress in Monolithic Silica Columns for High-Speed and High-Selectivity Separations

    NASA Astrophysics Data System (ADS)

    Ikegami, Tohru; Tanaka, Nobuo

    2016-06-01

    Monolithic silica columns have greater (through-pore size)/(skeleton size) ratios than particulate columns and fixed support structures in a column for chemical modification, resulting in high-efficiency columns and stationary phases. This review looks at how the size range of monolithic silica columns has been expanded, how high-efficiency monolithic silica columns have been realized, and how various methods of silica surface functionalization, leading to selective stationary phases, have been developed on monolithic silica supports, and provides information on the current status of these columns. Also discussed are the practical aspects of monolithic silica columns, including how their versatility can be improved by the preparation of small-sized structural features (sub-micron) and columns (1 mm ID or smaller) and by optimizing reaction conditions for in situ chemical modification with various restrictions, with an emphasis on recent research results for both topics.

  3. Recent Progress in Monolithic Silica Columns for High-Speed and High-Selectivity Separations.

    PubMed

    Ikegami, Tohru; Tanaka, Nobuo

    2016-06-12

    Monolithic silica columns have greater (through-pore size)/(skeleton size) ratios than particulate columns and fixed support structures in a column for chemical modification, resulting in high-efficiency columns and stationary phases. This review looks at how the size range of monolithic silica columns has been expanded, how high-efficiency monolithic silica columns have been realized, and how various methods of silica surface functionalization, leading to selective stationary phases, have been developed on monolithic silica supports, and provides information on the current status of these columns. Also discussed are the practical aspects of monolithic silica columns, including how their versatility can be improved by the preparation of small-sized structural features (sub-micron) and columns (1 mm ID or smaller) and by optimizing reaction conditions for in situ chemical modification with various restrictions, with an emphasis on recent research results for both topics. PMID:27306311

  4. Separating the effects of mutation and selection in producing DNA skew in bacterial chromosomes

    PubMed Central

    Morton, Richard A; Morton, Brian R

    2007-01-01

    Background Many bacterial chromosomes display nucleotide asymmetry, or skew, between the leading and lagging strands of replication. Mutational differences between these strands result in an overall pattern of skew that is centered about the origin of replication. Such a pattern could also arise from selection coupled with a bias for genes coded on the leading strand. The relative contributions of selection and mutation in producing compositional skew are largely unknown. Results We describe a model to quantify the contribution of mutational differences between the leading and lagging strands in producing replication-induced skew. When the origin and terminus of replication are known, the model can be used to estimate the relative accumulation of G over C and of A over T on the leading strand due to replication effects in a chromosome with bidirectional replication arms. The model may also be implemented in a maximum likelihood framework to estimate the locations of origin and terminus. We find that our estimations for the origin and terminus agree very well with the location of genes that are thought to be associated with the replication origin. This indicates that our model provides an accurate, objective method of determining the replication arms and also provides support for the hypothesis that these genes represent an ancestral cluster of origin-associated genes. Conclusion The model has several advantages over other methods of analyzing genome skew. First, it quantifies the role of mutation in generating skew so that its effect on composition, for example codon bias, can be assessed. Second, it provides an objective method for locating origin and terminus, one that is based on chromosome-wide accumulation of leading vs lagging strand nucleotide differences. Finally, the model has the potential to be utilized in a maximum likelihood framework in order to analyze the effect of chromosome rearrangements on nucleotide composition. PMID:17935620

  5. Distributed Physical and Molecular Separations for Selective Harvest of Higher Value Wheat Straw Components Project

    SciTech Connect

    N /A

    2004-09-30

    Wheat straw (Triticum aestivum L.) is an abundant source of plant fiber. It is regenerated, in large quantities, every year. At present, this potentially valuable resource is greatly under-exploited. Most of the excess straw biomass (i.e., tonnage above that required for agronomic cropping system sustainability) is managed through expensive chopping/tillage operations and/or burnt in the field following harvest, resulting in air pollution and associated health problems. Potential applications for wheat straw investigated within this project include energy and composites manufacture. Other methods of straw utilization that will potentially benefit from the findings of this research project include housing and building, pulp and paper, thermal insulation, fuels, and chemicals. This project focused on components of the feedstock assembly system for supplying a higher value small grains straw residue for (1) gasification/combustion and (2) straw-thermoplastic composites. This project was an integrated effort to solve the technological, infrastructural, and economic challenges associated with using straw residue for these bioenergy and bioproducts applications. The objective of the research is to contribute to the development of a low-capital distributed harvesting and engineered storage system for upgrading wheat straw to more desirable feedstocks for combustion and for straw-plastic composites. They investigated two processes for upgrading wheat straw to a more desirable feedstock: (1) an efficient combine-based threshing system for separating the intermodal stems from the leaves, sheaths, nodes, and chaff. (2) An inexpensive biological process using white-rot fungi to improve the composition of the mechanically processed straw stems.

  6. Distributed Physical and Molecular Separations for Selective Harvest of Higher Value Wheat Straw Components Project

    SciTech Connect

    Hess, J.R

    2005-01-31

    Wheat straw (Triticum aestivum L.) is an abundant source of plant fiber. It is regenerated, in large quantities, every year. At present, this potentially valuable resource is greatly under-exploited. Most of the excess straw biomass (i.e., tonnage above that required for agronomic cropping system sustainability) is managed through expensive chopping/tillage operations and/or burnt in the field following harvest, resulting in air pollution and associated health problems. Potential applications for wheat straw investigated within this project include energy and composites manufacture. Other methods of straw utilization that will potentially benefit from the findings of this research project include housing and building, pulp and paper, thermal insulation, fuels, and chemicals. This project focused on components of the feedstock assembly system for supplying a higher value small grains straw residue for (1) gasification/combustion and (2) straw-thermoplastic composites. This project was an integrated effort to solve the technological, infrastructural, and economic challenges associated with using straw residue for these bioenergy and bioproducts applications. The objective of the research is to contribute to the development of a low-capital distributed harvesting and engineered storage system for upgrading wheat straw to more desirable feedstocks for combustion and for straw-plastic composites. We investigated two processes for upgrading wheat straw to a more desirable feedstock: (1) An efficient combine-based threshing system for separating the internodal stems from the leaves, sheaths, nodes, and chaff. (2) An inexpensive biological process using white-rot fungi to improve the composition of the mechanically processed straw stems.

  7. WATER AND WASTEWATER POLISHING USING 3M SELECTIVE SEPARATION REMEDIATION CARTRIDGE TECHNOLOGY

    SciTech Connect

    Hoffmann, K. M.; Scanlan, T. J.; Seely, D. C.

    2002-02-25

    3M has developed technology for selectively removing trace levels of dissolved contaminant materials from liquids using systems operating at flow rates up to 50 gallons per minute. This technology combines active particle chemistries with a particle-loaded membrane to achieve a new medium for liquid waste processing--a spiral wound filter cartridge. This technology has shown success by generating high decontamination factors and reducing contaminants to part per trillion levels. The spiral wound cartridge offers simplified installation, convenient replacement, and clean, easy disposal of a concentrated waste. By incorporating small, high surface area particles (5 to 80 microns) into a sturdy, yet porous, membrane greater removal efficiencies of even trace contaminants can be achieved at higher flow rates than with conventional column systems. In addition, the captive-particle medium prevents channeling of liquids and insures uniform flow across the sorbing particle surface. The cartridges fit into standard, commercially-available housings and whole system capital costs are substantially lower than those of column or reverse osmosis systems. Developmental work at high degrees of water polishing have included removal of mercury from contaminated wastewater, various radionuclides from process water, and organometallic species from surface water discharges. Laboratory testing and on-site demonstration data of these applications show the levels of success that have been achieved thus far.

  8. Uranium bombs

    NASA Astrophysics Data System (ADS)

    DeGroot, Gerard

    2009-11-01

    Enrico Fermi was a brilliant physicist, but he did occasionally get things wrong. In 1934 he famously bombarded a sample of uranium with neutrons. The result was astounding: the experiment had, Fermi concluded, produced element 93, later called neptunium. The German physicist Ida Noddack, however, came to an even more spectacular conclusion, namely that Fermi had split the uranium nucleus to produce lighter elements. Noddack's friend Otto Hahn judged that idea preposterous and advised her to keep quiet, since ridicule could ruin a female physicist. She ignored that advice, and was, indeed, scorned.

  9. Column Testing and 1D Reactive Transport Modeling to Evaluate Uranium Plume Persistence Processes

    NASA Astrophysics Data System (ADS)

    Johnson, R. H.; Morrison, S.; Morris, S.; Tigar, A.; Dam, W. L.; Dayvault, J.

    2015-12-01

    At many U.S. Department of Energy Office of Legacy Management sites, 100 year natural flushing was selected as a remedial option for groundwater uranium plumes. However, current data indicate that natural flushing is not occurring as quickly as expected and solid-phase and aqueous uranium concentrations are persistent. At the Grand Junction, Colorado office site, column testing was completed on core collected below an area where uranium mill tailings have been removed. The total uranium concentration in this core was 13.2 mg/kg and the column was flushed with laboratory-created water with no uranium and chemistry similar to the nearby Gunnison River. The core was flushed for a total of 91 pore volumes producing a maximum effluent uranium concentration of 6,110 μg/L at 2.1 pore volumes and a minimum uranium concentration of 36.2 μg/L at the final pore volume. These results indicate complex geochemical reactions at small pore volumes and a long tailing affect at greater pore volumes. Stop flow data indicate the occurrence of non-equilibrium processes that create uranium concentration rebound. These data confirm the potential for plume persistence, which is occurring at the field scale. 1D reactive transport modeling was completed using PHREEQC (geochemical model) and calibrated to the column test data manually and using PEST (inverse modeling calibration routine). Processes of sorption, dual porosity with diffusion, mineral dissolution, dispersion, and cation exchange were evaluated separately and in combination. The calibration results indicate that sorption and dual porosity are major processes in explaining the column test data. These processes are also supported by fission track photographs that show solid-phase uranium residing in less mobile pore spaces. These procedures provide valuable information on plume persistence and secondary source processes that may be used to better inform and evaluate remedial strategies, including natural flushing.

  10. Using a Buffer Gas Modifier to Change Separation Selectivity in Ion Mobility Spectrometry

    PubMed Central

    Fernández-Maestre, Roberto; Wu, Ching; Hill, Herbert H.

    2010-01-01

    The mobilities of a set of common α-amino acids, four tetraalkylammonium ions, 2,4-dimethyl pyridine (2,4-lutidine), 2,6-di-tert-butyl pyridine (DTBP), and valinol were determined using electrospray ionization-ion mobility spectrometry-quadrupole mass spectrometry (ESI-IMS-QMS) while introducing 2-butanol into the buffer gas. The mobilities of the test compounds decreased by varying extents with 2-butanol concentration in the mobility spectrometer. When the concentration of 2-butanol increased from 0.0 to 6.8 mmol m−3 (2.5×102 ppmv), percentage reductions in mobilities were: 13.6% (serine), 12.2% (threonine), 10.4% (methionine), 10.3% (tyrosine), 9.8% (valinol), 9.2% (phenylalanine), 7.8% (tryptophan), 5.6% (2,4-lutidine), 2.2% (DTBP), 1.0% (tetramethylammonium ion, TMA, and tetraethylammonium ion, TEA), 0.0% (tetrapropylammonium ion, TPA), and 0.3% (tetrabutylammonium ion, TBA). These variations in mobility depended on the size and steric hindrance on the charge of the ions, and were due to formation of large ion-2-butanol clusters. This selective variation in mobilities was applied to the resolution of a mixture of compounds with similar reduced mobilities such as serine and valinol, which overlapped in N2-only buffer gas in the IMS spectrum. The relative insensitivity of tetraalkylammonium ions and DTBP to the introduction of 2-butanol into the buffer gas was explained by steric hindrance of the four alkyl substituents in tetraalkylammonium ions and the two tert-butyl groups in DTBP, which shielded the positive charge of the ion from the attachment of 2-butanol molecules. Low buffer gas temperatures (100 °C) produced the largest reductions in mobilities by increasing ion-2-butanol interactions and formation of clusters; high temperatures (250 °C) prevented the formation of clusters, and no reduction in ion mobility was obtained with the introduction of 2-butanol into the buffer gas. Low temperatures and high concentrations of 2-butanol produced a series of

  11. INFORMATION: Management Alert on Environmental Management's Select Strategy for Disposition of Savannah River Site Depleted Uranium Oxides

    SciTech Connect

    2010-04-01

    The Administration and the Congress, through policy statements and passage of the American Recovery and Reinvestment Act of 2009 (Recovery Act), have signaled that they hope that proactive actions by agency Inspectors General will help ensure that Federal Recovery Act activities are transparent, effective and efficient. In that context, the purpose of this management alert is to share with you concerns that have been raised to the Office of Inspector General regarding the planned disposition of the Savannah River Site's (SRS) inventory of Depleted Uranium (DU) oxides. This inventory, generated as a by-product of the nuclear weapons production process and amounting to approximately 15,600 drums of DU oxides, has been stored at SRS for decades. A Department source we deem reliable and credible recently came to the Office of Inspector General expressing concern that imminent actions are planned that may not provide for the most cost effective disposition of these materials. During April 2009, the Department chose to use funds provided under the Recovery Act to accelerate final disposition of the SRS inventory of DU oxides. After coordination with State of Utah regulators, elected officials and the U.S. Nuclear Regulatory Commission, the Department initiated a campaign to ship the material to a facility operated by EnergySolutions in Clive, Utah. Although one shipment of a portion of the material has already been sent to the EnergySolutions facility, the majority of the product remains at SRS. As had been planned, both for the shipment already made and those planned in the near term, the EnergySolutions facility was to have been the final disposal location for the material. Recently, a member of Congress and various Utah State officials raised questions regarding the radioactive and other constituents present in the DU oxides to be disposed of at the Clive, Utah, facility. These concerns revolved around the characterization of the material and its acceptability under

  12. Remedial action plan and site design for stabilization of the inactive uranium mill tailings site at Lowman, Idaho: Remedial action selection report for the Lowman UMTRA project site, Idaho. Final report

    SciTech Connect

    Matthews, M.L.; Nagel, J.

    1991-09-01

    The inactive uranium mill tailings site near Lowman, Idaho, was designated as one of 24 abandoned uranium tailings sites to be remediated by the US Department of Energy (DOE) under the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA). The UMTRCA requires that the US Nuclear Regulatory Commission (NRC) concur with the DOE`s remedial action plan and certify that the remedial action complies with the standards promulgated by the US Environmental Protection Agency (EPA). The remedial action plan (RAP), which includes this remedial action selection report (RAS), has been developed to serve a two-fold purpose. First, it describes the activities that are proposed by the DOE to accomplish long-term stabilization and control of residual radioactive materials at the inactive uranium processing site near Lowman, Idaho. Second, this document and the remainder of the RAP, upon concurrence and execution by the DOE, the State of Idaho, and the NRC, becomes Appendix B of the Cooperative Agreement (No. DE-FC04-85AL20535) between the DOE and the State of Idaho.

  13. Remedial Action Plan and site design for stabilization of the inactive uranium mill tailings site at Falls City, Texas. Remedial action selection report: Attachment 2, Geology report; Attachment 3, Groundwater hydrology report; Attachment 4, Water resources protection strategy: Final report

    SciTech Connect

    Chernoff, A.R.; Lacker, D.K.

    1992-09-01

    The uranium processing site near Falls City, Texas, was one of 24 inactive uranium mill sites designated to be remediated by the US Department of Energy (DOE) under Title I of the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA). The UMTRCA requires that the US Nuclear Regulatory Commission (NRC) concur with the DOE`s remedial action plan (RAP) and certify that the remedial action conducted at the site complies with the standards promulgated by the US Environmental Protection Agency (EPA). The RAP, which includes this summary remedial action selection report (RAS), serves a two-fold purpose. First, it describes the activities proposed by the DOE to accomplish long-term stabilization and control of the residual radioactive materials at the inactive uranium processing site near Falls City, Texas. Second, this document and the remainder of the RAP, upon concurrence and execution by the DOE, the State of Texas, and the NRC, becomes Appendix B of the Cooperative Agreement between the DOE and the State of Texas.

  14. Remedial action plan and site design for stabilization of the inactive uranium mill tailings site at Lowman, Idaho: Remedial action selection report for the Lowman UMTRA project site, Idaho

    SciTech Connect

    Matthews, M.L. . Uranium Mill Tailings Remedial Action Project Office); Nagel, J. . Div. of Environmental Quality)

    1991-09-01

    The inactive uranium mill tailings site near Lowman, Idaho, was designated as one of 24 abandoned uranium tailings sites to be remediated by the US Department of Energy (DOE) under the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA). The UMTRCA requires that the US Nuclear Regulatory Commission (NRC) concur with the DOE's remedial action plan and certify that the remedial action complies with the standards promulgated by the US Environmental Protection Agency (EPA). The remedial action plan (RAP), which includes this remedial action selection report (RAS), has been developed to serve a two-fold purpose. First, it describes the activities that are proposed by the DOE to accomplish long-term stabilization and control of residual radioactive materials at the inactive uranium processing site near Lowman, Idaho. Second, this document and the remainder of the RAP, upon concurrence and execution by the DOE, the State of Idaho, and the NRC, becomes Appendix B of the Cooperative Agreement (No. DE-FC04-85AL20535) between the DOE and the State of Idaho.

  15. Uranium chloride extraction of transuranium elements from LWR fuel

    SciTech Connect

    Miller, W.E.; Ackerman, J.P.; Battles, J.E.; Johnson, T.R.; Pierce, R.D.

    1991-12-31

    A process of separating transuranium actinide values from uranium values present in spent nuclear oxide fuels containing rare earth and noble metal fission products as well as other fission products is disclosed. The oxide fuel is reduced with Ca metal in the presence of Ca chloride and a U-Fe alloy which is liquid at about 800{degrees}C to dissolve uranium metal and the noble metal fission product metals and transuranium actinide metals and rare earth fission product metals leaving Ca chloride having CaO and fission products of alkali metals and the alkali earth metals and iodine dissolved therein. The Ca chloride and CaO and the fission products contained therein are separated from the U-Fe alloy and the metal values dissolved therein. The U-Fe alloy having dissolved therein reduced metals from the spent nuclear fuel is contacted with a mixture of one or more alkali metal or alkaline earth metal halides selected from the class consisting of alkali metal or alkaline earth metal and Fe or U halide or a combination thereof to transfer transuranium actinide metals and rare earth metals to the halide salt leaving the uranium and some noble metal fission products in the U-Fe alloy and thereafter separating the halide salt and the transuranium metals dissolved therein from the U-Fe alloy and the metals dissolved therein.

  16. Uranium chloride extraction of transuranium elements from LWR fuel

    DOEpatents

    Miller, William E.; Ackerman, John P.; Battles, James E.; Johnson, Terry R.; Pierce, R. Dean

    1992-01-01

    A process of separating transuranium actinide values from uranium values present in spent nuclear oxide fuels containing rare earth and noble metal fission products as well as other fission products is disclosed. The oxide fuel is reduced with Ca metal in the presence of Ca chloride and a U-Fe alloy which is liquid at about 800.degree. C. to dissolve uranium metal and the noble metal fission product metals and transuranium actinide metals and rare earth fission product metals leaving Ca chloride having CaO and fission products of alkali metals and the alkali earth metals and iodine dissolved therein. The Ca chloride and CaO and the fission products contained therein are separated from the U-Fe alloy and the metal values dissolved therein. The U-Fe alloy having dissolved therein reduced metals from the spent nuclear fuel is contacted with a mixture of one or more alkali metal or alkaline earth metal halides selected from the class consisting of alkali metal or alkaline earth metal and Fe or U halide or a combination thereof to transfer transuranium actinide metals and rare earth metals to the halide salt leaving the uranium and some noble metal fission products in the U-Fe alloy and thereafter separating the halide salt and the transuranium metals dissolved therein from the U-Fe alloy and the metals dissolved therein.

  17. Uranium chloride extraction of transuranium elements from LWR fuel

    DOEpatents

    Miller, W.E.; Ackerman, J.P.; Battles, J.E.; Johnson, T.R.; Pierce, R.D.

    1992-08-25

    A process of separating transuranium actinide values from uranium values present in spent nuclear oxide fuels containing rare earth and noble metal fission products as well as other fission products is disclosed. The oxide fuel is reduced with Ca metal in the presence of Ca chloride and a U-Fe alloy which is liquid at about 800 C to dissolve uranium metal and the noble metal fission product metals and transuranium actinide metals and rare earth fission product metals leaving Ca chloride having CaO and fission products of alkali metals and the alkali earth metals and iodine dissolved therein. The Ca chloride and CaO and the fission products contained therein are separated from the U-Fe alloy and the metal values dissolved therein. The U-Fe alloy having dissolved therein reduced metals from the spent nuclear fuel is contacted with a mixture of one or more alkali metal or alkaline earth metal halides selected from the class consisting of alkali metal or alkaline earth metal and Fe or U halide or a combination thereof to transfer transuranium actinide metals and rare earth metals to the halide salt leaving the uranium and some noble metal fission products in the U-Fe alloy and thereafter separating the halide salt and the transuranium metals dissolved therein from the U-Fe alloy and the metals dissolved therein. 1 figure.

  18. Machining of uranium and uranium alloys

    SciTech Connect

    Morris, T.O.

    1981-12-14

    Uranium and uranium alloys can be readily machined by conventional methods in the standard machine shop when proper safety and operating techniques are used. Material properties that affect machining processes and recommended machining parameters are discussed. Safety procedures and precautions necessary in machining uranium and uranium alloys are also covered. 30 figures.

  19. Selective adsorption of uranium(VI) from aqueous solutions using the ion-imprinted magnetic chitosan resins.

    PubMed

    Zhou, Limin; Shang, Chao; Liu, Zhirong; Huang, Guolin; Adesina, Adesoji A

    2012-01-15

    The ion-imprinted magnetic chitosan resins (IMCR) prepared using U(VI) as a template and glutaraldehyde as a cross-linker showed higher adsorption capacity and selectivity for the U(VI) ions compared with the non-imprinted magnetic chitosan resins (NIMCR) without a template. The results showed that the adsorption of U(VI) on the magnetic chitosan resins was affected by the initial pH value, the initial U(VI) concentration, as well as the temperature. Both kinetics and thermodynamic parameters of the adsorption process were estimated. These data indicated an exothermic spontaneous adsorption process that kinetically followed the second-order adsorption process. Equilibrium experiments were fitted in Langmuir, Freundlich, and Dubinin-Radushkevich adsorption isotherm models to show very good fits with the Langmuir isotherm equation for the monolayer adsorption process. The monolayer adsorption capacity values of 187.26 mg/g for IMCR and 160.77 mg/g for NIMCR were very close to the maximum capacity values obtained at pH 5.0, temperature 298 K, adsorbent dose 50 mg, and contact time 3 h. The selectivity coefficient of uranyl ions and other metal ions on IMCR indicated an overall preference for uranyl ions. Furthermore, the IMCR could be regenerated through the desorption of the U(VI) ions using 0.5 M HNO(3) solution and could be reused to adsorb again.

  20. SEPARATION OF URANYL AND RUTHENIUM VALUES BY THE TRIBUTYL PHOSPHATE EXTRACTION PROCESS

    DOEpatents

    Wilson, A.S.

    1961-05-01

    A process is given for separating uranyl values from ruthenium values contained in an aqueous 3 to 4 M nitric acid solution. After the addition of hydrogen peroxide to obtain a concentration of 0.3 M, the uranium is selectively extracted with kerosene-diluted tributyl phosphate.

  1. URANIUM ALLOYS

    DOEpatents

    Seybolt, A.U.

    1958-04-15

    Uranium alloys containing from 0.1 to 10% by weight, but preferably at least 5%, of either zirconium, niobium, or molybdenum exhibit highly desirable nuclear and structural properties which may be improved by heating the alloy to about 900 d C for an extended period of time and then rapidly quenching it.

  2. Uranium, natural

    Integrated Risk Information System (IRIS)

    Uranium , natural ; CASRN 7440 - 61 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  3. Wide Angle, Single Screen, Gridded Square-Loop Frequency Selective Surface for Diplexing Two Closely Separated Frequency Bands

    NASA Technical Reports Server (NTRS)

    Wu, Te-Kao (Inventor)

    1996-01-01

    The design and performance of a wide angle, single screen, frequency selective surface (FSS) with gridded square-loop path elements are described for diplexing closely separated signal bands, for example, X- and Ku-band signals in an Orbiting Very Long Baseline Interferometer (OVLBI) earth station reflector antenna system, as well as other applications such as military and commercial communications via satellites. Excellent agreement is obtained between the predicted and measured results of this FSS design using the gridded square-loop patch elements sandwiched between 0.0889 cm thick tetrafluoroethylene fluorocarbon polymer (PTFE) slabs. Resonant frequency drift is reduced by 1 GHz with an incidence angle from 0 deg normal to 40 deg from normal.

  4. The analysis of various size, visually selected and density and magnetically separated fractions of Luna 16 and 20 samples

    NASA Technical Reports Server (NTRS)

    Eglinton, G.; Gowar, A. P.; Jull, A. J. T.; Pillinger, C. T.; Agrell, S. O.; Agrell, J. E.; Long, J. V. P.; Bowie, S. H. U.; Simpson, P. R.; Beckinsale, R. D.

    1977-01-01

    Samples of Luna 16 and 20 have been separated according to size, visual appearance, density, and magnetic susceptibility. Selected aliquots were examined in eight British laboratories. The studies included mineralogy and petrology, selenochronology, magnetic characteristics, Mossbauer spectroscopy, oxygen isotope ratio determinations, cosmic ray track and thermoluminescence investigations, and carbon chemistry measurements. Luna 16 and 20 are typically mare and highland soils, comparing well with their Apollo counterparts, Apollo 11 and 16, respectively. Both soils are very mature (high free iron, carbide, and methane and cosmogenic Ar), while Luna 16, but not Luna 20, is characterized by a high content of glassy materials. An aliquot of anorthosite fragments, handpicked from Luna 20, had a gas retention age of about 4.3 plus or minus 0.1 Gy.

  5. A Tri-Band Frequency Selective Surface (FSS) to Diplex Widely Separated Bands for Millimeter Wave Remote Sensing

    NASA Astrophysics Data System (ADS)

    Poojali, Jayaprakash; Ray, Shaumik; Pesala, Bala; Chitti, Krishnamurthy V.; Arunachalam, Kavitha

    2016-10-01

    A substrate-backed frequency selective surface (FSS) is presented for diplexing the widely separated frequency spectrum centered at 55, 89, and 183 GHz with varying bandwidth for spatial separation in the quasi-optical feed network of the millimeter wave sounder. A unit cell composed of a crossed dipole integrated with a circular ring and loaded inside a square ring is optimized for tri-band frequency response with transmission window at 89 GHz and rejection windows at 55 and 183 GHz. The reflection and transmission losses predicted for the optimized unit cell (728 μm × 728 μm) composed of dissimilar resonant shapes is less than 0.5 dB for transverse electric (TE) and transverse magnetic (TM) polarizations and wide angle of incidence (0°-45°). The FSS is fabricated on a 175-μm-thick quartz substrate using microfabrication techniques. The transmission characteristics measured with continuous wave (CW) terahertz transmit receive system are in good agreement with the numerical simulations.

  6. Mechanistic Investigation of Solvent Extraction Based on Anion-Functionalized Ionic Liquids for Selective Separation of Rare-Earth Ions

    SciTech Connect

    Sun, Xiaoqi; Luo, Huimin; Dai, Sheng

    2013-01-01

    In this study, solvation has been found to be a dominant mechanism in a comprehensive ionic liquid based extraction system for rare earth elements (REEs). Trioctylmethylammonium di(2-ethylhexyl)phosphate ([TOMA][DEHP]), an ionic-liquid extractant, was used in 1-alkyl-3-methylimidizolium bis[(trifluoromethyl)sulfonyl]imide ([Cnmim][NTf2], n = 4, 6, 8, 10) and 1-alkyl-3-methylimidizolium bis(perfluoroethanesulfonyl)imide ([Cnmim][BETI], n = 4, 6, 8, 10) for the separation of REEs. Surprisingly, a very similar extraction behavior was observed even as the carbon chain length on the ionic-liquid (IL) cation increased from butyl (C4) to hexyl (C6), to octyl (C8), to decyl (C10). This behavior is in sharp contrast to that exhibited by the conventional neutral extractants, whose extraction efficiencies are strongly dependent on the hydrophobicity of IL cations. Furthermore, the addition of IL cations ([Cnmim]+) or IL anions ([NTf2]- or [BETI]-) to the aqueous phase had little effect on the extraction behavior of the above extraction system, ruling out the strong involvement of the ion-exchange mechanism associated with traditional IL-based extraction systems. Results showed that the extractabilities and selectivities of REEs using [TOMA][DEHP] in [C10mim][NTf2]/[BETI] are several orders of magnitude better than those achieved using conventional organic solvent, diisopropylbenzene (DIPB). This study highlights the potential of developing a comprehensive IL-based extraction strategy for REEs separations.

  7. Separation of selected transition metals by capillary chelation ion chromatography using acetyl-iminodiacetic acid modified capillary polymer monoliths.

    PubMed

    Moyna, Áine; Connolly, Damian; Nesterenko, Ekaterina; Nesterenko, Pavel N; Paull, Brett

    2012-08-01

    Capillary housed laurylmethacrylate-co-ethylene dimethacrylate (LMA-co-EDMA) polymer monoliths were fabricated, functionalised with varying amounts of vinyl azlactone, followed by immobilisation of iminodiacetic acid (IDA), forming a range of acetyl-iminodiacetic acid (AIDA) functionalised monoliths, applied to the chelation ion chromatographic separation of selected transition and heavy metals. A number of monoliths of varying length and ligand density were prepared, resulting in increased cation retention and chromatographic resolution on those displaying the highest capacity. Ligand density and related column capacity were confirmed visually using scanning capacitively coupled contactless conductivity detection (sC(4)D) techniques. Column temperature studies to determine retention mechanism and the effect of temperature on the retention of Mn(II), Cd(II) and Cu(II) was investigated, showing an increase in retention with increased temperature for Cd(II) and Cu(II), whilst a decrease in retention was obtained for Mn(II). Isocratic capillary chelation ion chromatographic separations of Mn(II), Cd(II) and Cu(II) were obtained, with dual peak detection demonstrated using combined on-column C(4)D detection and UV-Visible detection following the post-capillary column reaction of the eluted metals with 4-(2-pyridylazo) resorcinol (PAR).

  8. Selective Breeding for Infant Rat Separation-Induced Ultrasonic Vocalizations: Developmental Precursors of Passive and Active Coping Styles

    PubMed Central

    Brunelli, Susan A.; Hofer, Myron A.

    2009-01-01

    Human depression and anxiety disorders show inherited biases across generations, as do antisocial disorders characterized by aggression. Each condition is preceded in children by behavioral inhibition or aggressive behavior, respectively, and both are characterized by separation anxiety disorders. In affected families, adults and children exhibit different forms of altered autonomic nervous system regulation and hypothalamic-pituitary-adrenal activity in response to stress. Because it is difficult to determine mechanisms accounting for these associations, animal studies are useful for studying the fundamental relationships between biological and behavioral traits. Pharmacologic and behavioral studies suggest that infant rat ultrasonic vocalizations (USV) are a measure of an early anxiety-like state related to separation anxiety. However, it was not known whether or not early ultrasound emissions in infant rats are markers for genetic risk for anxiety states later in life. To address these questions, we selectively bred two lines of rats based on high and low rates of USV to isolation at postnatal (P) 10 days of age. To our knowledge, ours is the only laboratory that has ever selectively bred on the basis of an infantile trait related to anxiety. The High and Low USV lines show two distinct sets of patterns of behavior, physiology and neurochemistry from infancy through adulthood. As adults High line rats demonstrate “anxious”/“depressed” phenotypes in behavior and autonomic nervous system (ANS) regulation to standard laboratory tests. In Lows, on the other hand, behavior and autonomic regulation are consistent with an “aggressive” phenotype. The High and Low USV lines are the first genetic animal models implicating long-term associations of contrasting “coping styles” with early attachment responses. They thus present a potentially powerful model for examining gene-environment interactions in the development of life-long affective regulation. PMID

  9. Novel core-shell cerium(IV)-immobilized magnetic polymeric microspheres for selective enrichment and rapid separation of phosphopeptides.

    PubMed

    Wang, Zhi-Gang; Cheng, Gong; Liu, Yan-Lin; Zhang, Ji-Lin; Sun, De-Hui; Ni, Jia-Zuan

    2014-03-01

    In this work, novel magnetic polymeric core-shell structured microspheres with immobilized Ce(IV), Fe3O4@SiO2@PVPA-Ce(IV), were designed rationally and synthesized successfully via a facile route for the first time. Magnetic Fe3O4@SiO2 microspheres were first prepared by directly coating a thin layer of silica onto Fe3O4 magnetic particles using a sol-gel method, a poly(vinylphosphonic acid) (PVPA) shell was then coated on the Fe3O4@SiO2 microspheres to form Fe3O4@SiO2@PVPA microspheres through a radical polymerization reaction, and finally Ce(IV) ions were robustly immobilized onto the Fe3O4@SiO2@PVPA microspheres through strong chelation between Ce(IV) ions and phosphate moieties in the PVPA. The applicability of the Fe3O4@SiO2@PVPA-Ce(IV) microspheres for selective enrichment and rapid separation of phosphopeptides from proteolytic digests of standard and real protein samples was investigated. The results demonstrated that the core-shell structured Fe3O4@SiO2@PVPA-Ce(IV) microspheres with abundant Ce(IV) affinity sites and excellent magnetic responsiveness can effectively purify phosphopeptides from complex biosamples for MS detection taking advantage of the rapid magnetic separation and the selective affinity between Ce(IV) ions and phosphate moieties of the phosphopeptides. Furthermore, they can be effectively recycled and show good reusability, and have better performance than commercial TiO2 beads and homemade Fe3O4@PMAA-Ce(IV) microspheres. Thus the Fe3O4@SiO2@PVPA-Ce(IV) microspheres can benefit greatly the mass spectrometric qualitative analysis of phosphopeptides in phosphoproteome research.

  10. Uranium uptake by hydroponically cultivated crop plants.

    PubMed

    Soudek, Petr; Petrová, Sárka; Benešová, Dagmar; Dvořáková, Marcela; Vaněk, Tomáš

    2011-06-01

    Hydroponicaly cultivated plants were grown on medium containing uranium. The appropriate concentrations of uranium for the experiments were selected on the basis of a standard ecotoxicity test. The most sensitive plant species was determined to be Lactuca sativa with an EC(50) value about 0.1mM. Cucumis sativa represented the most resistant plant to uranium (EC(50)=0.71 mM). Therefore, we used the uranium in a concentration range from 0.1 to 1mM. Twenty different plant species were tested in hydroponic solution supplemented by 0.1mM or 0.5mM uranium concentration. The uranium accumulation of these plants varied from 0.16 mg/g DW to 0.011 mg/g DW. The highest uranium uptake was determined for Zea mays and the lowest for Arabidopsis thaliana. The amount of accumulated uranium was strongly influenced by uranium concentration in the cultivation medium. Autoradiography showed that uranium is mainly localized in the root system of the plants tested. Additional experiments demonstrated the possibility of influencing the uranium uptake from the cultivation medium by amendments. Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba up to 2.8 times or 1.9 times, respectively. Phosphate deficiency increased uranium uptake up to 4.5 times or 3.9 times, respectively, by Brassica oleracea and S. alba. In the case of deficiency of iron or presence of cadmium ions we did not find any increase in uranium accumulation.

  11. RECOVERY OF URANIUM FROM CARBONATE LEACH LIQUORS

    DOEpatents

    Wilson, H.F.

    1958-07-01

    An improved process is described for the recovery of uranium from vanadifrous ores. In the prior art such ores have been digested with alkali carbonate solutions at a pH of less than 10 and then contacted with a strong base anion exchange resin to separate uranium from vanadium. It has been found that if the exchamge resin feed solution has its pH adjusted to the range 10.8 to 11.8, that vanadium adsorption on the resin is markedly decreased and the separation of uranium from the vanadium is thereby improved.

  12. PROCESS FOR CONTINUOUSLY SEPARATING IRRADIATION PRODUCTS OF THORIUM

    DOEpatents

    Hatch, L.P.; Miles, F.T.; Sheehan, T.V.; Wiswall, R.H.; Heus, R.J.

    1959-07-01

    A method is presented for separating uranium-233 and protactinium from thorium-232 containing compositions which comprises irradiating finely divided particles of said thorium with a neutron flux to form uranium-233 and protactinium, heating the neutron-irradiated composition in a fluorine and hydrogen atmosphere to form volatile fluorides of uranium and protactinium and thereafter separating said volatile fluorides from the thorium.

  13. Uranium-Lead Zircon Ages and Sr, Nd, and Pb Isotope Geochemistry of Selected Plutonic Rocks from Western Idaho

    USGS Publications Warehouse

    Unruh, Daniel M.; Lund, Karen; Kuntz, Mel A.; Snee, Lawrence W.

    2008-01-01

    Across the Salmon River suture in western Idaho, where allochthonous Permian to Cretaceous oceanic rocks are juxtaposed against Proterozoic North American rocks, a wide variety of plutonic rocks are exposed. Available data indicate much variation in composition, source, and structural state of these plutons. The plutonic rocks were long described as the western border zone of the Cretaceous Idaho batholith but limited pre-existing age data indicate more complicated origins. Because the affinity and age of the plutonic rocks cannot be reliably determined from field relations, TIMS U-Pb dating in conjunction with Sr, Nd, and Pb isotopic studies of selected plutons across the suture in western Idaho were undertaken. The data indicate three general groups of plutons including (1) those that intruded the island arc terranes during the Triassic and Jurassic, those that intruded near the western edge of oceanic rocks along the suture in the Early Cretaceous, and the plutons of the Idaho batholith that intruded Proterozoic North American rocks in the Late Cretaceous. Plutons that intruded Proterozoic North American rocks commonly include xenocrystic zircons and in several cases, ages could not be determined. The least radiogenic Sr and most radiogenic Nd are found among the Blue Mountains superterrane island arc samples. Suture-zone plutons have isotopic characteristics that span the range between Idaho batholith and island arc samples but mostly follow island arc signatures. Plutons of the Idaho batholith have the most radiogenic initial Pb and Sr ratios and the least radiogenic Nd of the samples analyzed.

  14. Uranium in Soils Integrated Demonstration: Technology summary, March 1994

    SciTech Connect

    Not Available

    1994-03-01

    A recent Pacific Northwest Laboratory (PNL) study identified 59 waste sites at 14 DOE facilities across the nation that exhibit radionuclide contamination in excess of established limits. The rapid and efficient characterization of these sites, and the potentially contaminated regions that surround them represents a technological challenge with no existing solution. In particular, the past operations of uranium production and support facilities at several DOE sites have occasionally resulted in the local contamination of surface and subsurface soils. Such contamination commonly occurs within waste burial sites, cribs, pond bottom sediments and soils surrounding waste tanks or uranium scrap, ore, tailings, and slag heaps. The objective of the Uranium In Soils Integrated Demonstration is to develop optimal remediation methods for soils contaminated with radionuclides, principally uranium (U), at DOE sites. It is examining all phases involved in an actual cleanup, including all regulatory and permitting requirements, to expedite selection and implementation of the best technologies that show immediate and long-term effectiveness specific to the Fernald Environmental Management Project (FEMP) and applicable to other radionuclide contaminated DOE sites. The demonstration provides for technical performance evaluations and comparisons of different developmental technologies at FEMP sites, based on cost-effectiveness, risk-reduction effectiveness, technology effectiveness, and regulatory and public acceptability. Technology groups being evaluated include physical and chemical contaminant separations, in situ remediation, real-time characterization and monitoring, precise excavation, site restoration, secondary waste treatment, and soil waste stabilization.

  15. Summarizing results on the performance of a selective set of atmospheric plasma jets for separation of photons and reactive particles

    NASA Astrophysics Data System (ADS)

    Schneider, Simon; Jarzina, Fabian; Lackmann, Jan-Wilm; Golda, Judith; Layes, Vincent; Schulz-von der Gathen, Volker; Bandow, Julia Elisabeth; Benedikt, Jan

    2015-11-01

    A microscale atmospheric-pressure plasma jet is a remote plasma jet, where plasma-generated reactive particles and photons are involved in substrate treatment. Here, we summarize our efforts to develop and characterize a particle- or photon-selective set of otherwise identical jets. In that way, the reactive species or photons can be used separately or in combination to study their isolated or combined effects to test whether the effects are additive or synergistic. The final version of the set of three jets—particle-jet, photon-jet and combined jet—is introduced. This final set realizes the highest reproducibility of the photon and particle fluxes, avoids turbulent gas flow, and the fluxes of the selected plasma-emitted components are almost identical in the case of all jets, while the other component is effectively blocked, which was verified by optical emission spectroscopy and mass spectrometry. Schlieren-imaging and a fluid dynamics simulation show the stability of the gas flow. The performance of these selective jets is demonstrated with the example of the treatment of E. coli bacteria with the different components emitted by a He-only, a He/N2 and a He/O2 plasma. Additionally, measurements of the vacuum UV photon spectra down to the wavelength of 50 nm can be made with the photon-jet and the relative comparison of spectral intensities among different gas mixtures is reported here. The results will show that the vacuum UV photons can lead to the inactivation of the E.coli bacteria.

  16. In Vivo Nanodetoxication for Acute Uranium Exposure.

    PubMed

    Guzmán, Luis; Durán-Lara, Esteban F; Donoso, Wendy; Nachtigall, Fabiane M; Santos, Leonardo S

    2015-06-15

    Accidental exposure to uranium is a matter of concern, as U(VI) is nephrotoxic in both human and animal models, and its toxicity is associated to chemical toxicity instead of radioactivity. We synthesized different PAMAM G4 and G5 derivatives in order to prove their interaction with uranium and their effect on the viability of red blood cells in vitro. Furthermore, we prove the effectiveness of the selected dendrimers in an animal model of acute uranium intoxication. The dendrimer PAMAM G4-Lys-Fmoc-Cbz demonstrated the ability to chelate the uranyl ion in vivo, improving the biochemical and histopathologic features caused by acute intoxication with uranium.

  17. In Vivo Nanodetoxication for Acute Uranium Exposure.

    PubMed

    Guzmán, Luis; Durán-Lara, Esteban F; Donoso, Wendy; Nachtigall, Fabiane M; Santos, Leonardo S

    2015-01-01

    Accidental exposure to uranium is a matter of concern, as U(VI) is nephrotoxic in both human and animal models, and its toxicity is associated to chemical toxicity instead of radioactivity. We synthesized different PAMAM G4 and G5 derivatives in order to prove their interaction with uranium and their effect on the viability of red blood cells in vitro. Furthermore, we prove the effectiveness of the selected dendrimers in an animal model of acute uranium intoxication. The dendrimer PAMAM G4-Lys-Fmoc-Cbz demonstrated the ability to chelate the uranyl ion in vivo, improving the biochemical and histopathologic features caused by acute intoxication with uranium. PMID:26083036

  18. Synthesis, Development, and Testing of High-Surface-Area Polymer-Based Adsorbents for the Selective Recovery of Uranium from Seawater

    DOE PAGES

    Oyola, Yatsandra; Janke, Christopher J.; Dai, Sheng

    2016-02-29

    The ocean contains uranium with an approximate concentration of 3.34 ppb, which can serve as an incredible supply source to sustain nuclear energy in the United States. Unfortunately, technology currently available to recover uranium from seawater is not efficient enough and mining uranium on land is still more economical. For this study, we have developed polymer-based adsorbents with high uranium adsorption capacities by grafting amidoxime onto high-surface-area polyethylene (PE) fibers. Various process conditions have been screened, in combination with developing a rapid testing protocol (<24 h), to optimize the process. These adsorbents are synthesized through radiation-induced grafting of acrylonitrile (AN)more » and methacrylic acid (MAA) onto PE fibers, followed by the conversion of nitriles to amidoximes and basic conditioning. In addition, the uranium adsorption capacity, measured in units of gU/kgads, is greatly increased by reducing the diameter of the PE fiber or changing its morphology. An increase in the surface area of the PE polymer fiber allows for more grafting sites that are positioned in more-accessible locations, thereby increasing access to grafted molecules that would normally be located in the interior of a fiber with a larger diameter. Polymer fibers with hollow morphologies are able to adsorb beyond 1 order of magnitude more uranium from simulated seawater than current commercially available adsorbents. Finally, several high-surface-area fibers were tested in natural seawater and were able to extract 5–7 times more uranium than any adsorbent reported to date.« less

  19. Novel microorganism for selective separation of coal from ash and pyrite. Seventh quarterly technical progress report, April 1, 1995--June 30, 1995

    SciTech Connect

    Misra, M.; Smith, R.W.; Raichur, A.M.

    1996-12-31

    The selective separation of pyrite and ash-forming minerals from coal can be accomplished by flotation, agglomeration and selective flocculation. The methods currently used for selective flocculation of coals include addition of natural or synthetic polymeric flocculants along with precise pH control. In some cases, these flocculants are nonselective or work imperfectly. It is known that many highly charged planktonic algae and bacteria will adhere to certain solid surfaces if the charge or hydrophobic interaction between the organism and the solids are favorable for adhesion. The resultant microorganism-mineral entities, if formed, can flocculate and can be separated. In addition, many living organisms produce extracellular biopolymers that can also cause flocculation. The microorganism, M. phlei, has the properties of being both highly charged and highly hydrophobic. The aim of the present investigation is to study the effectiveness of M. phlei and biopolymers derived from the organism for selective flocculation and separation of fine coal from pyrite and ash.

  20. Extraction of Uranium, Neptunium and Plutonium from Caustic Media

    SciTech Connect

    Delmau, Laetitia H.; Bonnesen, Peter V.; Engle, Nancy L.; Raymond, Kenneth N.; Xu, Jade

    2004-03-28

    5 Fundamental research on uranium, neptunium and plutonium separation from alkaline media using solvent extraction is being conducted. Specific extractants for these actinides from alkaline media have been synthesized to investigate the feasibility of selective removal of these elements. Two families of extractants have been studied: terephthalamide and tetra(hydroxybenzyl)ethylene diamine derivatives. Fundamental studies were conducted to characterize their extraction behavior from a wide variety of aqueous conditions. The terephthalamide derivatives exhibit a significant extraction strength along with a discriminatory behavior among the actinides, plutonium being extracted the most strongly. Quantitative extraction of plutonium and moderate extraction of neptunium and uranium was achieved from a simple caustic solution. Interestingly, strontium is also quantitatively extracted by these derivatives. However, their stability to highly caustic solutions still needs to be imp roved. Tetra(hydroxybenzyl)ethylene diamine derivatives exhibit a very good stability to caustic conditions and are currently being studied.

  1. Extraction of uranium from seawater using magnetic adsorbents

    SciTech Connect

    Yamashita, H.; Fujita, K.; Nakajima, F.; Ozawa, Y.; Murata, T.

    1981-01-01

    A new process for the extraction of uranium from seawater was developed. In the process, uranium adsorption is effected using powdered magnetic adsorbents; the adsorbents are then separated from seawater using magnetic separation technology. This process is superior to a column method using a granulated hydrous titanium oxide adsorber bed in the following ways: (1) a higher rate of adsorption is realized because smaller particles are used in the uranium adsorption; and (2) blocking, which is inevitable in an adsorber bed, is eliminated. The composite hydrous titanium-iron oxide as a magnetic adsorbent having high uranium adsorption capacity and magnetization can be prepared by adding urea to a mixed solution of titanium sulfate and ferrous sulfate. Adsorption and desoprtion of uranium and the removal of the adsorbent using a small-scale uranium extraction plant (about 15 m/sup 3//d) is reported, and the feasibility of uranium extraction from seawater by this process is demonstrated. 10 figures.

  2. RECOVERY OF URANIUM FROM TUNGSTEN

    DOEpatents

    Newnam, K.

    1959-02-01

    A method is presented for the rccovery of uranium which has adhered to tungsten parts in electromagnetic isotope separation apparatus. Such a tungsten article is dissolved electrolytically in 20% NaOH by using the tungsten article as the anode. The resulting solution, containing soluble sodium lungstate and an insoluble slime, is then filtered. The slime residue is ignited successively with sodium nitrate and sodium pyrosulfate and leashed, and the resulting filtrates are combined with the original filtrate. Uranium is then recovered from the combined flltrates by diuranate precipitation.

  3. Derived enriched uranium market

    SciTech Connect

    Rutkowski, E.

    1996-12-01

    The potential impact on the uranium market of highly enriched uranium from nuclear weapons dismantling in the Russian Federation and the USA is analyzed. Uranium supply, conversion, and enrichment factors are outlined for each country; inventories are also listed. The enrichment component and conversion components are expected to cause little disruption to uranium markets. The uranium component of Russian derived enriched uranium hexafluoride is unresolved; US legislation places constraints on its introduction into the US market.

  4. Size-selective DNA separation: recovery spectra help determine the sodium chloride (NaCl) and polyethylene glycol (PEG) concentrations required.

    PubMed

    He, Zhangyong; Xu, Hong; Xiong, Min; Gu, Hongchen

    2014-10-01

    In the presence of sodium chloride (NaCl), DNA fragments can be size-selectively separated by varying the final concentration of polyethylene glycol (PEG). This separation strategy in combination with the use of paramagnetic particles provides a valuable platform for achieving the desired DNA size interval, which is important in automated library preparation for high-throughput DNA sequencing. Here, we report the establishment of recovery spectra of DNA fragments that enable the determination of suitable NaCl and PEG concentrations for size-selective separation. Firstly, at a given NaCl concentration, the recovery equation was obtained by fitting the DNA recovery ratios versus the PEG concentrations using the logistic function to determine the required parameters. Secondly, the slope function of the recovery equation was achieved by deducing its first derivative. Therefore, the recovery spectrum can be generated using the slope function based on those parameters. According to the recovery spectra of different length DNA fragments, suitable NaCl and PEG concentrations can be determined, respectively, by calculating their resolution values and recovery ratios. The strategy was effectively applied to the size-selective separation of 532-, 400-, and 307-bp fragments at the selected reagent concentrations with recoveries of 96.9, 64.7, and 85.9%, respectively. Our method enables good predictions of NaCl and PEG concentrations for size-selective DNA separation.

  5. Selective separation of peptides contained in a rapeseed (Brassica campestris L.) protein hydrolysate using UF/NF membranes.

    PubMed

    Tessier, B; Harscoat-Schiavo, C; Marc, I

    2006-05-17

    The ability of a charged UF membrane to fractionate the small peptides found in a rapeseed protein enzymatic hydrolysate, according to their charge characteristics, was investigated. The complexity of such a hydrolysate has required the setting up of technological alternatives to isolate the small peptides, to obtain a more efficient separation among the numerous peptide species. A preliminary step consisted of precipitation followed by filtration with a 3000 g/mol molecular weight cutoff (MWCO) membrane to obtain a solution concentrated in small peptides. The possibility of fractionating these small peptides by a charged 1000 g/mol MWCO membrane was investigated. The study enabled us to assess the contribution of electrostatic interactions during fractionation. The effect of pH and ionic strength on the peptide transmission was studied. The ionic strength contribution was considered by studying the effect on the selectivity of a desalting step by nanofiltration on a 500 g/mol MWCO membrane. Peptide transmission was lower at pH 9 than pH 4, and it was the lowest at pH 9 and low ionic strength. Ionic strength had a significant influence at pH 9 but showed no influence at pH 4. The amino acid analysis and capillary electrophoresis revealed that negatively charged (acid) peptides were found in lower proportions in the permeate. The opposite trend was observed for basic peptides, whereas neutral peptides were found in the same proportion in the retentate and the permeate. These results can be explained, according to the Donnan theory, by the existence of attractive and repulsive forces at the membrane-solution interface. Selectivity between basic and acid peptides was as high as 1.90 at pH 9 and low ionic strength. A rough sketch of a membrane-based process is proposed to fractionate rapeseed peptide mixtures. Results obtained were reproducible within 10%.

  6. Effect of interwire separation on growth kinetics and properties of site-selective GaAs nanowires

    SciTech Connect

    Rudolph, D.; Schweickert, L.; Morkötter, S.; Loitsch, B.; Hertenberger, S.; Becker, J.; Bichler, M.; Finley, J. J.; Koblmüller, G.; Abstreiter, G.

    2014-07-21

    We report tuning of the growth kinetics, geometry, and properties of autocatalytic GaAs nanowires (NW) by precisely controlling their density on SiO{sub 2}-mask patterned Si (111) substrates using selective area molecular beam epitaxy. Using patterned substrates with different mask opening size (40–120 nm) and pitch (0.25–3 μm), we find that the NW geometry (length, diameter) is independent of the opening size, in contrast to non-catalytic GaAs NWs, whereas the NW geometry strongly depends on pitch, i.e., interwire separation and NW density. In particular, two distinct growth regimes are identified: a diffusion-limited regime for large pitches (low NW density) and a competitive growth regime for smaller pitches (high NW density), where axial and radial NW growth rates are reduced. The transition between these two regimes is significantly influenced by the growth conditions and shifts to smaller pitches with increasing As/Ga flux ratio. Ultimately, the pitch-dependent changes in growth kinetics lead to distinctly different photoluminescence properties, highlighting that mask template design is a very critical parameter for tuning intrinsic NW properties.

  7. Identification of RNase-resistant RNAs in Saccharomyces cerevisiae extracts: Separation from chromosomal DNA by selective precipitation.

    PubMed

    Rodriguez, Blanca V; Malczewskyj, Eric T; Cabiya, Joshua M; Lewis, L Kevin; Maeder, Corina

    2016-01-01

    High-quality chromosomal DNA is a requirement for many biochemical and molecular biological techniques. To isolate cellular DNA, standard protocols typically lyse cells and separate nucleic acids from other biological molecules using a combination of chemical and physical methods. After a standard chemical-based protocol to isolate chromosomal DNA from Saccharomyces cerevisiae and then treatment with RNase A to degrade RNA, two RNase-resistant bands persisted when analyzed using gel electrophoresis. Interestingly, such resistant bands did not appear in preparations of Escherichia coli bacterial DNA after RNase treatment. Several enzymatic, chemical, and physical methods were employed in an effort to remove the resistant RNAs, including use of multiple RNases and alcohol precipitation, base hydrolysis, and chromatographic methods. These experiments resulted in the development of a new method for isolation of S. cerevisiae chromosomal DNA. This method utilizes selective precipitation of DNA in the presence of a potassium acetate/isopropanol mixture and produces high yields of chromosomal DNA without detectable contaminating RNAs.

  8. Disperse fine equiaxed alpha alumina nanoparticles with narrow size distribution synthesised by selective corrosion and coagulation separation

    PubMed Central

    Pu, Sanxu; Li, Lu; Ma, Ji; Lu, Fuliang; Li, Jiangong

    2015-01-01

    Disperse fine equiaxed α-Al2O3 nanoparticles with narrow size distribution are important materials in nanotechnology and nanomaterials, but syntheses of disperse fine equiaxed α-Al2O3 nanoparticles usually result in fine γ-Al2O3 nanoparticles or large α-Al2O3 nanoparticles larger than 15 nm. α-Al2O3 has a higher surface energy than γ-Al2O3 and becomes thermodynamically not stable with respect to γ-Al2O3 at specific surface areas larger than 100 m2/g (at sizes smaller than 15 nm for spherical particles) at room temperature. So disperse fine equiaxed α-Al2O3 nanoparticles smaller than 15 nm with narrow size distribution are extremely difficult to synthesise. Here we show the successful synthesis of disperse fine equiaxed α-Al2O3 nanoparticles with average sizes below 10 nm and narrow size distribution by selective corrosion and refined fractionated coagulation separation. An almost fully dense nanocrystalline α-Al2O3 ceramic with a relative density of 99.5% and an average grain size of 60 nm can be sintered from disperse fine equiaxed α-Al2O3 nanoparticles with narrow size distribution. PMID:26166455

  9. Phenylboronate chromatography selectively separates glycoproteins through the manipulation of electrostatic, charge transfer, and cis-diol interactions.

    PubMed

    Carvalho, Rimenys J; Woo, James; Aires-Barros, M Raquel; Cramer, Steven M; Azevedo, Ana M

    2014-10-01

    Phenylboronate chromatography (PBC) has been applied for several years, however details regarding the mechanisms of interactions between the ligand and biomolecules are still scarce. The goal of this work is to investigate the various chemical interactions between proteins and their ligands, using a protein library containing both glycosylated and nonglycosylated proteins. Differences in the adsorption of these proteins over a pH range from 4 to 9 were related to two main properties: charge and presence of glycans. Acidic or neutral proteins were strongly adsorbed below pH 8 although the uncharged trigonal form of phenylboronate (PB) is less susceptible to forming electrostatic and cis-diol interactions with proteins. The glycosylated proteins were only adsorbed above pH 8 when the electrostatic repulsion between the boronate anion and the protein surface was mitigated (at 200 mM NaCl). All basic proteins were highly adsorbed above pH 8 with PB also acting as a cation-exchanger with binding occurring through electrostatic interactions. Batch adsorption performed at acidic conditions in the presence of Lewis base showed that charge-transfer interactions are critical for protein retention. This study demonstrates the multimodal interaction of PBC, which can be a selective tool for separation of different classes of proteins. PMID:25130283

  10. Disperse fine equiaxed alpha alumina nanoparticles with narrow size distribution synthesised by selective corrosion and coagulation separation

    NASA Astrophysics Data System (ADS)

    Pu, Sanxu; Li, Lu; Ma, Ji; Lu, Fuliang; Li, Jiangong

    2015-07-01

    Disperse fine equiaxed α-Al2O3 nanoparticles with narrow size distribution are important materials in nanotechnology and nanomaterials, but syntheses of disperse fine equiaxed α-Al2O3 nanoparticles usually result in fine γ-Al2O3 nanoparticles or large α-Al2O3 nanoparticles larger than 15 nm. α-Al2O3 has a higher surface energy than γ-Al2O3 and becomes thermodynamically not stable with respect to γ-Al2O3 at specific surface areas larger than 100 m2/g (at sizes smaller than 15 nm for spherical particles) at room temperature. So disperse fine equiaxed α-Al2O3 nanoparticles smaller than 15 nm with narrow size distribution are extremely difficult to synthesise. Here we show the successful synthesis of disperse fine equiaxed α-Al2O3 nanoparticles with average sizes below 10 nm and narrow size distribution by selective corrosion and refined fractionated coagulation separation. An almost fully dense nanocrystalline α-Al2O3 ceramic with a relative density of 99.5% and an average grain size of 60 nm can be sintered from disperse fine equiaxed α-Al2O3 nanoparticles with narrow size distribution.

  11. Uranium Industry Annual, 1992

    SciTech Connect

    Not Available

    1993-10-28

    The Uranium Industry Annual provides current statistical data on the US uranium industry for the Congress, Federal and State agencies, the uranium and electric utility industries, and the public. The feature article, ``Decommissioning of US Conventional Uranium Production Centers,`` is included. Data on uranium raw materials activities including exploration activities and expenditures, resources and reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities including domestic uranium purchases, commitments by utilities, procurement arrangements, uranium imports under purchase contracts and exports, deliveries to enrichment suppliers, inventories, secondary market activities, utility market requirements, and uranium for sale by domestic suppliers are presented in Chapter 2.

  12. A graphene oxide/amidoxime hydrogel for enhanced uranium capture

    PubMed Central

    Wang, Feihong; Li, Hongpeng; Liu, Qi; Li, Zhanshuang; Li, Rumin; Zhang, Hongsen; Liu, Lianhe; Emelchenko, G. A.; Wang, Jun

    2016-01-01

    The efficient development of selective materials for the recovery of uranium from nuclear waste and seawater is necessary for their potential application in nuclear fuel and the mitigation of nuclear pollution. In this work, a graphene oxide/amidoxime hydrogel (AGH) exhibits a promising adsorption performance for uranium from various aqueous solutions, including simulated seawater. We show high adsorption capacities (Qm = 398.4 mg g−1) and high % removals at ppm or ppb levels in aqueous solutions for uranium species. In the presence of high concentrations of competitive ions such as Mg2+, Ca2+, Ba2+ and Sr2+, AGH displays an enhanced selectivity for uranium. For low uranium concentrations in simulated seawater, AGH binds uranium efficiently and selectively. The results presented here reveal that the AGH is a potential adsorbent for remediating nuclear industrial effluent and adsorbing uranium from seawater. PMID:26758649

  13. A graphene oxide/amidoxime hydrogel for enhanced uranium capture

    NASA Astrophysics Data System (ADS)

    Wang, Feihong; Li, Hongpeng; Liu, Qi; Li, Zhanshuang; Li, Rumin; Zhang, Hongsen; Liu, Lianhe; Emelchenko, G. A.; Wang, Jun

    2016-01-01

    The efficient development of selective materials for the recovery of uranium from nuclear waste and seawater is necessary for their potential application in nuclear fuel and the mitigation of nuclear pollution. In this work, a graphene oxide/amidoxime hydrogel (AGH) exhibits a promising adsorption performance for uranium from various aqueous solutions, including simulated seawater. We show high adsorption capacities (Qm = 398.4 mg g‑1) and high % removals at ppm or ppb levels in aqueous solutions for uranium species. In the presence of high concentrations of competitive ions such as Mg2+, Ca2+, Ba2+ and Sr2+, AGH displays an enhanced selectivity for uranium. For low uranium concentrations in simulated seawater, AGH binds uranium efficiently and selectively. The results presented here reveal that the AGH is a potential adsorbent for remediating nuclear industrial effluent and adsorbing uranium from seawater.

  14. PROCESSES OF RECOVERING URANIUM FROM A CALUTRON

    DOEpatents

    Baird, D.O.; Zumwalt, L.R.

    1958-07-15

    An improved process is described for recovering the residue of a uranium compound which has been subjected to treatment in a calutron, from the parts of the calutron disposed in the source region upon which the residue is deposited. The process may be utilized when the uranium compound adheres to a surface containing metals of the group consisting of copper, iron, chromium, and nickel. The steps comprise washing the surface with an aqueous acidic oxidizing solvent for the uranium whereby there is obtained an acidic aqueous Solution containing uranium as uranyl ions and metals of said group as impurities, treating the acidic solution with sodium acetate in the presenee of added sodium nitrate to precipitate the uranium as sodium uranyl acetate away from the impurities in the solution, and separating the sodium uranyl acetate from the solution.

  15. Remedial action plan and site design for stabilization of the inactive uranium processing site at Naturita, Colorado. Remedial Action Selection Report, Appendix B of Attachment 2: Geology report, Final

    SciTech Connect

    Not Available

    1994-03-01

    The uranium processing site near Naturita, Colorado, is one of 24 inactive uranium mill sites designated to be cleaned up by the US Department of Energy (DOE) under the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA), 42 USC {section} 7901 et seq. Part of the UMTRCA requires that the US Nuclear Regulatory Commission (NRC) concur with the DOE`s remedial action plan (RAP) and certify that the remedial action conducted at the site complies with the standards promulgated by the US Environmental Protection Agency (EPA). Included in the RAP is this Remedial Action Selection Report (RAS), which describes the proposed remedial action for the Naturita site. An extensive amount of data and supporting information has been generated and evaluated for this remedial action. These data and supporting information are not incorporated into this single document but are included or referenced in the supporting documents. The RAP consists of this RAS and four supporting documents or attachments. This Attachment 2, Geology Report describes the details of geologic, geomorphic, and seismic conditions at the Dry Flats disposal site.

  16. Isotope Separation and Advanced Manufacturing Technology. ISAM semiannual report, Volume 3, Number 1, October 1993--March 1994

    SciTech Connect

    Carpenter, J.; Kan, T.

    1994-10-01

    This is the fourth issue of a semiannual report for the Isotope Separation and Advanced Materials Manufacturing (ISAM) Technology Program at Lawrence Livermore National Laboratory. Primary objectives include: (I) the Uranium Atomic Vapor Laser Isotope Separation (UAVLIS) process, which is being developed and prepared for deployment as an advanced uranium enrichment capability; (II) Advanced manufacturing technologies, which include industrial laser and E-beam material processing and new manufacturing technologies for uranium, plutonium, and other strategically important materials in support of DOE and other national applications. This report features progress in the ISAM Program from October 1993 through March 1994. Selected papers were indexed separately for inclusion in the Energy Science and Technology Database.

  17. Novel microorganism for selective separation of coal from ash and pyrite. Third quarterly technical progress report, March 1, 1994--May 31, 1994

    SciTech Connect

    Misra, M.; Smith, R.W.; Raichur, A.M.

    1994-11-01

    The selective separation of pyrite and ash-forming minerals from coal can be accomplished by flotation, agglomeration and selective flocculation. The methods currently used for selective flocculation of coals include addition of natural or synthetic polymeric flocculants along with precise pH control. In some cases, these flocculants are nonselective or work imperfectly. It is known that many highly charged planktonic algae and bacteria will adhere to certain solid surface if the charge or hydrophobic interaction between the organism and the solids are favorable for adhesion. The resultant microorganism-mineral entities if formed can flocculate and can be separated. In addition, many living organism produce extracellular biopolymers that can also cause flocculation. The microorganism, M. phlei, has the properties of being both highly charged and highly hydrophobic. The aim of the present investigation is to study the effectiveness of M. phlei and biopolymers derived from the organism for selective flocculation of fine coal from ash and pyrite.

  18. PRODUCTION OF URANIUM TETRACHLORIDE

    DOEpatents

    Calkins, V.P.

    1958-12-16

    A process is descrlbed for the production of uranium tetrachloride by contacting uranlum values such as uranium hexafluoride, uranlum tetrafluoride, or uranium oxides with either aluminum chloride, boron chloride, or sodium alumlnum chloride under substantially anhydrous condltlons at such a temperature and pressure that the chlorldes are maintained in the molten form and until the uranium values are completely converted to uranlum tetrachloride.

  19. PRODUCTION OF URANIUM MONOCARBIDE

    DOEpatents

    Powers, R.M.

    1962-07-24

    A method of making essentially stoichiometric uranium monocarbide by pelletizing a mixture of uranium tetrafluoride, silicon, and carbon and reacting the mixture at a temperature of approximately 1500 to 1700 deg C until the reaction goes to completion, forming uranium monocarbide powder and volatile silicon tetrafluoride, is described. The powder is then melted to produce uranium monocarbide in massive form. (AEC)

  20. A Honeycomb-Structured Ti-6Al-4V Oil-Gas Separation Rotor Additively Manufactured by Selective Electron Beam Melting for Aero-engine Applications

    NASA Astrophysics Data System (ADS)

    Tang, H. P.; Wang, Q. B.; Yang, G. Y.; Gu, J.; Liu, N.; Jia, L.; Qian, M.

    2016-03-01

    Oil -gas separation is a key process in an aero-engine lubrication system. This study reports an innovative development in oil -gas separation. A honeycomb-structured rotor with hexagonal cone-shaped pore channels has been designed, additively manufactured from Ti-6Al-4V using selective electron beam melting (SEBM) and assessed for oil -gas separation for aero-engine application. The Ti-6Al-4V honeycomb structure showed a high compressive strength of 110 MPa compared to less than 20 MPa for metal foam structures. The oil -gas separation efficiency of the honeycomb-structured separation rotor achieved 99.8% at the rotation speed of 6000 rpm with much lower ventilation resistance (17.3 kPa) than that of the separator rotor constructed using a Ni-Cr alloy foam structure (23.5 kPa). The honeycomb-structured Ti-6Al-4V separator rotor produced by SEBM provides a promising solution to more efficient oil -gas separation in the aero-engine lubrication system.

  1. Bioremediation of uranium contaminated soils and wastes

    SciTech Connect

    Francis, A.J.

    1998-12-31

    Contamination of soils, water, and sediments by radionuclides and toxic metals from uranium mill tailings, nuclear fuel manufacturing and nuclear weapons production is a major concern. Studies of the mechanisms of biotransformation of uranium and toxic metals under various microbial process conditions has resulted in the development of two treatment processes: (1) stabilization of uranium and toxic metals with reduction in waste volume and (2) removal and recovery of uranium and toxic metals from wastes and contaminated soils. Stabilization of uranium and toxic metals in wastes is accomplished by exploiting the unique metabolic capabilities of the anaerobic bacterium, Clostridium sp. The radionuclides and toxic metals are solubilized by the bacteria directly by enzymatic reductive dissolution, or indirectly due to the production of organic acid metabolites. The radionuclides and toxic metals released into solution are immobilized by enzymatic reductive precipitation, biosorption and redistribution with stable mineral phases in the waste. Non-hazardous bulk components of the waste volume. In the second process uranium and toxic metals are removed from wastes or contaminated soils by extracting with the complexing agent citric acid. The citric-acid extract is subjected to biodegradation to recover the toxic metals, followed by photochemical degradation of the uranium citrate complex which is recalcitrant to biodegradation. The toxic metals and uranium are recovered in separate fractions for recycling or for disposal. The use of combined chemical and microbiological treatment process is more efficient than present methods and should result in considerable savings in clean-up and disposal costs.

  2. RECOVERY OF URANIUM BY SECONDARY XANTHATE COMPLEXING

    DOEpatents

    Neville, O.K.

    1959-09-01

    A method is described for separating and recovering uranium values contained in an acidic aqueous solution together with thorium or protactinium values. In accordance with the invention, the acidic solution containing uranium in the uranyl form is contacted with an organic xanthate. The xanthate forms a urano-xanthate complex but is substantially non-reactive with thorium and protactinium. The urano-xanthate complex is recovered by organic solvent extraction.

  3. The selection of suitable columns for a reversed-phase liquid chromatographic separation of beta-lactam antibiotics and related substances via chromatographic column parameters.

    PubMed

    Zhang, Wei-qing; Hu, Qiu-xin; Zhang, Xia; Li, Ya-ping; Wang, Ming-juan; Hu, Chang-qin

    2014-01-01

    The selection of RP-LC columns suitable for a particular analysis in official compendia is difficult as only a general description of the stationary phase in the description of a LC method is given. General methods to characterize RP-LC columns often assume that each of the column parameters is equally important. This can cause the user to select columns inappropriate for particular analyses. This paper focuses on the relationship between the critical peak pairs and the column parameters (H, S, A, B, and C) in the Snyder/Dolan column characterization methodology to find the key parameters influencing real separations. Some varieties of β-lactam antibiotics and their related compounds were used as test compounds. We found column parameter A to be the most important factor affecting their separation. Parameters B and C also played an important role in some separation processes. This indicated that the hydrogen bonding of column and solute can directly affect the separation of β-lactam antibiotics. Choosing columns for which column parameter A is near 0.1 can facilitate the ideal separations of impurities from β-lactam antibiotics. The most suitable column for any common pharmaceutical analysis could be selected easily if the key column parameters would be given in the description of the chromatographic method. For these reasons, key column parameters should be listed in the monographs of official compendia.

  4. Plutonium recovery from spent reactor fuel by uranium displacement

    SciTech Connect

    Ackerman, J.P.

    1991-12-31

    This report discusses a process for separating uranium values and transuranic values from fission products containing rare earth values when the values which are contained together in a molten chloride salt electrolyte. A molten chloride salt electrolyte with a first ratio of plutonium chloride to uranium chloride is contacted with both a solid cathode and an anode having values of uranium and fission products including plutonium. A voltage is applied across the anode and cathode electrolytically to transfer uranium and plutonium from the anode to the electrolyte while uranium values in the electrolyte electrolytically deposit as uranium metal on the solid cathode in an amount equal to the uranium and plutonium transferred from the anode causing the electrolyte to have a second ratio of plutonium chloride to uranium chloride. Then the solid cathode with the uranium metal deposited thereon is removed and molten cadmium having uranium dissolved therein is brought into contact with the electrolyte resulting in chemical transfer of plutonium values from the electrolyte to the molten cadmium and transfer of uranium values from the molten cadmium to the electrolyte until the first ratio of plutonium chloride to uranium chloride is re-established.

  5. Plutonium recovery from spent reactor fuel by uranium displacement

    SciTech Connect

    Ackerman, J.P.

    1991-01-01

    This report discusses a process for separating uranium values and transuranic values from fission products containing rare earth values when the values which are contained together in a molten chloride salt electrolyte. A molten chloride salt electrolyte with a first ratio of plutonium chloride to uranium chloride is contacted with both a solid cathode and an anode having values of uranium and fission products including plutonium. A voltage is applied across the anode and cathode electrolytically to transfer uranium and plutonium from the anode to the electrolyte while uranium values in the electrolyte electrolytically deposit as uranium metal on the solid cathode in an amount equal to the uranium and plutonium transferred from the anode causing the electrolyte to have a second ratio of plutonium chloride to uranium chloride. Then the solid cathode with the uranium metal deposited thereon is removed and molten cadmium having uranium dissolved therein is brought into contact with the electrolyte resulting in chemical transfer of plutonium values from the electrolyte to the molten cadmium and transfer of uranium values from the molten cadmium to the electrolyte until the first ratio of plutonium chloride to uranium chloride is re-established.

  6. Plutonium recovery from spent reactor fuel by uranium displacement

    DOEpatents

    Ackerman, John P.

    1992-01-01

    A process for separating uranium values and transuranic values from fission products containing rare earth values when the values are contained together in a molten chloride salt electrolyte. A molten chloride salt electrolyte with a first ratio of plutonium chloride to uranium chloride is contacted with both a solid cathode and an anode having values of uranium and fission products including plutonium. A voltage is applied across the anode and cathode electrolytically to transfer uranium and plutonium from the anode to the electrolyte while uranium values in the electrolyte electrolytically deposit as uranium metal on the solid cathode in an amount equal to the uranium and plutonium transferred from the anode causing the electrolyte to have a second ratio of plutonium chloride to uranium chloride. Then the solid cathode with the uranium metal deposited thereon is removed and molten cadmium having uranium dissolved therein is brought into contact with the electrolyte resulting in chemical transfer of plutonium values from the electrolyte to the molten cadmium and transfer of uranium values from the molten cadmium to the electrolyte until the first ratio of plutonium chloride to uranium chloride is reestablished.

  7. Plutonium recovery from spent reactor fuel by uranium displacement

    DOEpatents

    Ackerman, J.P.

    1992-03-17

    A process is described for separating uranium values and transuranic values from fission products containing rare earth values when the values are contained together in a molten chloride salt electrolyte. A molten chloride salt electrolyte with a first ratio of plutonium chloride to uranium chloride is contacted with both a solid cathode and an anode having values of uranium and fission products including plutonium. A voltage is applied across the anode and cathode electrolytically to transfer uranium and plutonium from the anode to the electrolyte while uranium values in the electrolyte electrolytically deposit as uranium metal on the solid cathode in an amount equal to the uranium and plutonium transferred from the anode causing the electrolyte to have a second ratio of plutonium chloride to uranium chloride. Then the solid cathode with the uranium metal deposited thereon is removed and molten cadmium having uranium dissolved therein is brought into contact with the electrolyte resulting in chemical transfer of plutonium values from the electrolyte to the molten cadmium and transfer of uranium values from the molten cadmium to the electrolyte until the first ratio of plutonium chloride to uranium chloride is reestablished.

  8. Evidence for Natural Selection in Nucleotide Content Relationships Based on Complete Mitochondrial Genomes: Strong Effect of Guanine Content on Separation between Terrestrial and Aquatic Vertebrates

    PubMed Central

    Sorimachi, Kenji; Okayasu, Teiji

    2015-01-01

    The complete vertebrate mitochondrial genome consists of 13 coding genes. We used this genome to investigate the existence of natural selection in vertebrate evolution. From the complete mitochondrial genomes, we predicted nucleotide contents and then separated these values into coding and non-coding regions. When nucleotide contents of a coding or non-coding region were plotted against the nucleotide content of the complete mitochondrial genomes, we obtained linear regression lines only between homonucleotides and their analogs. On every plot using G or A content purine, G content in aquatic vertebrates was higher than that in terrestrial vertebrates, while A content in aquatic vertebrates was lower than that in terrestrial vertebrates. Based on these relationships, vertebrates were separated into two groups, terrestrial and aquatic. However, using C or T content pyrimidine, clear separation between these two groups was not obtained. The hagfish (Eptatretus burgeri) was further separated from both terrestrial and aquatic vertebrates. Based on these results, nucleotide content relationships predicted from the complete vertebrate mitochondrial genomes reveal the existence of natural selection based on evolutionary separation between terrestrial and aquatic vertebrate groups. In addition, we propose that separation of the two groups might be linked to ammonia detoxification based on high G and low A contents, which encode Glu rich and Lys poor proteins. PMID:25853054

  9. Evidence for Natural Selection in Nucleotide Content Relationships Based on Complete Mitochondrial Genomes: Strong Effect of Guanine Content on Separation between Terrestrial and Aquatic Vertebrates.

    PubMed

    Sorimachi, Kenji; Okayasu, Teiji

    2015-01-01

    The complete vertebrate mitochondrial genome consists of 13 coding genes. We used this genome to investigate the existence of natural selection in vertebrate evolution. From the complete mitochondrial genomes, we predicted nucleotide contents and then separated these values into coding and non-coding regions. When nucleotide contents of a coding or non-coding region were plotted against the nucleotide content of the complete mitochondrial genomes, we obtained linear regression lines only between homonucleotides and their analogs. On every plot using G or A content purine, G content in aquatic vertebrates was higher than that in terrestrial vertebrates, while A content in aquatic vertebrates was lower than that in terrestrial vertebrates. Based on these relationships, vertebrates were separated into two groups, terrestrial and aquatic. However, using C or T content pyrimidine, clear separation between these two groups was not obtained. The hagfish (Eptatretus burgeri) was further separated from both terrestrial and aquatic vertebrates. Based on these results, nucleotide content relationships predicted from the complete vertebrate mitochondrial genomes reveal the existence of natural selection based on evolutionary separation between terrestrial and aquatic vertebrate groups. In addition, we propose that separation of the two groups might be linked to ammonia detoxification based on high G and low A contents, which encode Glu rich and Lys poor proteins.

  10. Polyoxometalates-based heterometallic organic-inorganic hybrid materials for rapid adsorption and selective separation of methylene blue from aqueous solutions.

    PubMed

    Yi, Fei-Yan; Zhu, Wei; Dang, Song; Li, Jian-Ping; Wu, Dai; Li, Yun-hui; Sun, Zhong-Ming

    2015-02-25

    A series of LnCu-polyoxometalates (POMs) were used for dye-wastewater treatment with rapid (within 1 min) and large-scale adsorption (up to 391.3 mg g(-1)) as well as excellent selective separation of cationic dyes. Furthermore, the adsorbed dyes can be easily desorbed, and the POMs still work very efficiently even after three cycles.

  11. URANIUM DECONTAMINATION

    DOEpatents

    Buckingham, J.S.; Carroll, J.L.

    1959-12-22

    A process is described for reducing the extractability of ruthenium, zirconium, and niobium values into hexone contained in an aqueous nitric acid uranium-containing solution. The solution is made acid-deficient, heated to between 55 and 70 deg C, and at that temperature a water-soluble inorganic thiosulfate is added. By this, a precipitate is formed which carries the bulk of the ruthenium, and the remainder of the ruthenium as well as the zirconium and niobium are converted to a hexone-nonextractable form. The rutheniumcontaining precipitate can either be removed from the solu tion or it can be dissolved as a hexone-non-extractable compound by the addition of sodium dichromate prior to hexone extraction.

  12. SEPARATION OF PLUTONIUM

    DOEpatents

    Maddock, A.G.; Smith, F.

    1959-08-25

    A method is described for separating plutonium from uranium and fission products by treating a nitrate solution of fission products, uranium, and hexavalent plutonium with a relatively water-insoluble fluoride to adsorb fission products on the fluoride, treating the residual solution with a reducing agent for plutonium to reduce its valence to four and less, treating the reduced plutonium solution with a relatively insoluble fluoride to adsorb the plutonium on the fluoride, removing the solution, and subsequently treating the fluoride with its adsorbed plutonium with a concentrated aqueous solution of at least one of a group consisting of aluminum nitrate, ferric nitrate, and manganous nitrate to remove the plutonium from the fluoride.

  13. Separation of actinides from spent nuclear fuel: A review.

    PubMed

    Veliscek-Carolan, Jessica

    2016-11-15

    This review summarises the methods currently available to extract radioactive actinide elements from solutions of spent nuclear fuel. This separation of actinides reduces the hazards associated with spent nuclear fuel, such as its radiotoxicity, volume and the amount of time required for its' radioactivity to return to naturally occurring levels. Separation of actinides from environmental water systems is also briefly discussed. The actinide elements typically found in spent nuclear fuel include uranium, plutonium and the minor actinides (americium, neptunium and curium). Separation methods for uranium and plutonium are reasonably well established. On the other hand separation of the minor actinides from lanthanide fission products also present in spent nuclear fuel is an ongoing challenge and an area of active research. Several separation methods for selective removal of these actinides from spent nuclear fuel will be described. These separation methods include solvent extraction, which is the most commonly used method for radiochemical separations, as well as the less developed but promising use of adsorption and ion-exchange materials. PMID:27427893

  14. Separation of actinides from spent nuclear fuel: A review.

    PubMed

    Veliscek-Carolan, Jessica

    2016-11-15

    This review summarises the methods currently available to extract radioactive actinide elements from solutions of spent nuclear fuel. This separation of actinides reduces the hazards associated with spent nuclear fuel, such as its radiotoxicity, volume and the amount of time required for its' radioactivity to return to naturally occurring levels. Separation of actinides from environmental water systems is also briefly discussed. The actinide elements typically found in spent nuclear fuel include uranium, plutonium and the minor actinides (americium, neptunium and curium). Separation methods for uranium and plutonium are reasonably well established. On the other hand separation of the minor actinides from lanthanide fission products also present in spent nuclear fuel is an ongoing challenge and an area of active research. Several separation methods for selective removal of these actinides from spent nuclear fuel will be described. These separation methods include solvent extraction, which is the most commonly used method for radiochemical separations, as well as the less developed but promising use of adsorption and ion-exchange materials.

  15. PROCESSING OF URANIUM-METAL-CONTAINING FUEL ELEMENTS

    DOEpatents

    Moore, R.H.

    1962-10-01

    A process is given for recovering uranium from neutronbombarded uranium- aluminum alloys. The alloy is dissolved in an aluminum halide--alkali metal halide mixture in which the halide is a mixture of chloride and bromide, the aluminum halide is present in about stoichiometric quantity as to uranium and fission products and the alkali metal halide in a predominant quantity; the uranium- and electropositive fission-products-containing salt phase is separated from the electronegative-containing metal phase; more aluminum halide is added to the salt phase to obtain equimolarity as to the alkali metal halide; adding an excess of aluminum metal whereby uranium metal is formed and alloyed with the excess aluminum; and separating the uranium-aluminum alloy from the fission- productscontaining salt phase. (AEC)

  16. Method for fabricating laminated uranium composites

    DOEpatents

    Chapman, L.R.

    1983-08-03

    The present invention is directed to a process for fabricating laminated composites of uranium or uranium alloys and at least one other metal or alloy. The laminated composites are fabricated by forming a casting of the molten uranium with the other metal or alloy which is selectively positioned in the casting and then hot-rolling the casting into a laminated plate in or around which the casting components are metallurgically bonded to one another to form the composite. The process of the present invention provides strong metallurgical bonds between the laminate components primarily since the bond disrupting surface oxides on the uranium or uranium alloy float to the surface of the casting to effectively remove the oxides from the bonding surfaces of the components.

  17. Stationary phases in the screening of drug/impurity profiles and in their separation method development: identification of columns with different and similar selectivities.

    PubMed

    Van Gyseghem, E; Jimidar, M; Sneyers, R; De Smet, M; Verhoeven, E; Vander Heyden, Y

    2006-06-01

    The classification or characterization of stationary phases based on chromatographic parameters, in general, requires different test solutes/mixtures and several mobile phases. To simplify the classification/characterization of reversed-phase liquid chromatographic columns, to be used in separating drug/impurity profiles, a new test procedure was proposed. It consists of injecting two mixtures of relatively similar active substances applying a standard gradient. The aim was to evaluate from this approach the selectivity differences and overall separation quality of newly tested columns compared to that in an earlier selected set of eight stationary phases. The selectivity differences of the columns were evaluated by correlation coefficient-based weighted-average-linkage dendrograms and color maps. Derringer's desirability functions were used to rank similar stationary phases according to their overall separation quality. Four columns of 27 examined were, for instance, considered different from the earlier selected eight and could be added to the selection. A number of tested stationary phases might be considered as alternatives for some from the initial set. For three columns the newly tested stationary phases did not contain alternatives.

  18. APPLICATION OF CYCLODEXTRIN-MODIFIED MICELLAR ELECTRONKINETIC CHROMATOGRAPHY TO THE SEPARATIONS OF SELECTED NEUTRAL PESTICIDES AND THEIR ENANTIOMERS

    EPA Science Inventory

    The environmental chemistry of chiral pesticides is receiving increased attention - enantiomeric ratios are being measured and enantioselective degradation processes are being reported. The requisite analysis involves separation of the various enantiomers. Mixtures of three class...

  19. METHOD OF SEPARATION

    DOEpatents

    Boyd, G.E.

    1958-08-26

    A process is presented fer separating uranium, plutonium, and fission products ions from uranyl nitrate solutions having a pH value between 1 and 3 obtained by dissolving neutron irradiated uranium. The method consists in passing such solutions through a bed of cation exchange resin, which may be a sulfonated phenol formaidehyde type. Following the adsorption step the resin is first treated with a solution of 0.2M to 0.3M sulfuric acid to desorb the uranium. Fission product ions are then desorbed by treating the resin in phosphoric acid and 1M in nitric acid. Lastly, the plutonium may be desorbed by treating the resin with a solution approximately 0.8M in phosphoric acid and 1M in nitric acid.

  20. Process for electroslag refining of uranium and uranium alloys

    DOEpatents

    Lewis, P.S. Jr.; Agee, W.A.; Bullock, J.S. IV; Condon, J.B.

    1975-07-22

    A process is described for electroslag refining of uranium and uranium alloys wherein molten uranium and uranium alloys are melted in a molten layer of a fluoride slag containing up to about 8 weight percent calcium metal. The calcium metal reduces oxides in the uranium and uranium alloys to provide them with an oxygen content of less than 100 parts per million. (auth)

  1. URANIUM RECOVERY PROCESS

    DOEpatents

    Bailes, R.H.; Long, R.S.; Olson, R.S.; Kerlinger, H.O.

    1959-02-10

    A method is described for recovering uranium values from uranium bearing phosphate solutions such as are encountered in the manufacture of phosphate fertilizers. The solution is first treated with a reducing agent to obtain all the uranium in the tetravalent state. Following this reduction, the solution is treated to co-precipitate the rcduced uranium as a fluoride, together with other insoluble fluorides, thereby accomplishing a substantially complete recovery of even trace amounts of uranium from the phosphate solution. This precipitate usually takes the form of a complex fluoride precipitate, and after appropriate pre-treatment, the uranium fluorides are leached from this precipitate and rccovered from the leach solution.

  2. PRODUCTION OF PURIFIED URANIUM

    DOEpatents

    Burris, L. Jr.; Knighton, J.B.; Feder, H.M.

    1960-01-26

    A pyrometallurgical method for processing nuclear reactor fuel elements containing uranium and fission products and for reducing uranium compound; to metallic uranium is reported. If the material proccssed is essentially metallic uranium, it is dissolved in zinc, the sulution is cooled to crystallize UZn/sub 9/ , and the UZn/sub 9/ is distilled to obtain uranium free of fission products. If the material processed is a uranium compound, the sollvent is an alloy of zinc and magnesium and the remaining steps are the same.

  3. URANIUM RECOVERY AND PURIFICATION PROCESS AND PRODUCTION OF HIGH PURITY URANIUM TETRAFLUORIDE

    DOEpatents

    Bailes, R.H.; Long, R.S.; Grinstead, R.R.

    1957-09-17

    A process is described wherein an anionic exchange technique is employed to separate uramium from a large variety of impurities. Very efficient and economical purification of contamimated uranium can be achieved by treatment of the contaminated uranium to produce a solution containing a high concentration of chloride. Under these conditions the uranium exists as an aniomic chloride complex. Then the uranium chloride complex is adsorbed from the solution on an aniomic exchange resin, whereby a portion of the impurities remain in the solution and others are retained with the uramium by the resin. The adsorbed impurities are then removed by washing the resin with pure concentrated hydrochloric acid, after which operation the uranium is eluted with pure water yielding an acidic uranyl chloride solution of high purity.

  4. Purification of thorium from uranium-233 process residue

    SciTech Connect

    Webb, O.F.; Boll, R.A.; Lucero, A.J.; DePaoli, D.W.

    1999-04-01

    Thorium-229 can be used to produce {sup 213}Bi. Researchers in phase 1 human trials are investigating the use of antibodies labeled with {sup 213}Bi for selectively destroying leukemia cells. Other types of cancer may potentially be treated using similar approaches. Crude {sup 229}Th was liberated from Rachig rings by sonication in 7.5 M HNO{sub 3} followed by filtration. Contaminants included significant levels of uranium, a number of other metals, and radiolytic by-products of di-(2-butyl) phosphoric acid extractant (which was used i the original separation of {sup 233}U from thorium). Thorium was selectively retained on Reillex HPQ anion-exchange resin from 7.5 M HNO{sub 3} at 65%, where U(VI), Ac(III), Fe(III), Al(III), Ra(II), and Pb(II) were eluted. Thorium and uranium isotherms on Reillex HPQ are reported. The thorium was then easily eluted form the bed with 0.1 M HNO{sub 3}. To overcome mass transfer limitations of the resin, the separation was conducted at 65 C. The resin stood up well to use over several campaigns. Other researchers have reported that HPQ has excellent radiological and chemical stability. The eluted thorium was further purified by hydroxide precipitation from the organic contaminants. This process yielded 65 mCi of {sup 229}Th.

  5. Flash chromatography on cartridges for the separation of plant extracts: rules for the selection of chromatographic conditions and comparison with medium pressure liquid chromatography.

    PubMed

    Weber, Petra; Hamburger, Matthias; Schafroth, Nina; Potterat, Olivier

    2011-03-01

    Empirical rules for the selection of chromatographic conditions on flash chromatography cartridges were developed, with an emphasis on gradient mode. These rules were then tested with separation of extracts from important medicinal plants including Curcuma xanthorrhiza, Piper nigrum and Salvia milthiorrhiza. Sepacore® cartridges enabled a good separation of compounds with a broad range of polarity, as typically found in plant extracts. The chromatographic resolution remained, however, lower than that achieved on classical columns packed with material of smaller particle size. For poorly soluble extracts, solid introduction gave better results than liquid injection.

  6. FLUORIDE VOLATILITY PROCESS FOR THE RECOVERY OF URANIUM

    DOEpatents

    Katz, J.J.; Hyman, H.H.; Sheft, I.

    1958-04-15

    The separation and recovery of uraniunn from contaminants introduced by neutron irradiation by a halogenation and volatilization method are described. The irradiated uranium is dissolved in bromine trifluoride in the liquid phase. The uranium is converted to the BrF/sub 3/ soluble urmium hexafluoride compound whereas the fluorides of certain contaminating elements are insoluble in liquid BrF/sub 3/, and the reaction rate of the BrF/sub 3/ with certain other solid uranium contamirnnts is sufficiently slower than the reaction rate with uranium that substantial portions of these contaminating elements will remain as solids. These solids are then separated from the solution by a distillation, filtration, or centrifugation step. The uranium hexafluoride is then separated from the balance of the impurities and solvent by one or more distillations.

  7. Technology selection and comparative performance of source-separating wastewater management systems in Sweden and The Netherlands.

    PubMed

    Mels, A; van Betuw, W; Braadbaart, O

    2007-01-01

    The research described in this paper has evaluated five demonstration projects with source-separating sanitation at neighbourhood scale, 10 years or more after their establishment. It presents the results of two systems with local grey water treatment in The Netherlands and three sites with urine separation in Sweden. The study has focused on (1) the drivers and barriers of the stakeholders that were responsible for project implementation and (2) the comparative performance of the source separation systems after their establishment. In The Netherlands the main drivers were water use reduction, combating sewer overflows and reduction of emissions. For the Swedish cases the main drivers of the involved actors were nutrient recycling, emission reduction and an active policy of the local government. The main barriers in all cases were higher investment costs and low experience with new sanitation approaches systems compared with the conventional system. Three of the sites showed a lower performance with respect to public health because effluent monitoring protocols for the grey water treatment systems were not in place or people could have direct contact with faeces. Lack of operation and maintenance is a cause of occasional failure for the grey water treatment systems, while the dominant failure reason for the urine separation systems was pipe clogging. The inventory showed that source-separating sanitation systems have a high potential to save or recover resources (water and nutrients).

  8. Detection of depleted uranium in urine of veterans from the 1991 Gulf War.

    PubMed

    Gwiazda, R H; Squibb, K; McDiarmid, M; Smith, D

    2004-01-01

    American soldiers involved in "friendly fire" accidents during the 1991 Gulf War were injured with depleted-uranium-containing fragments or possibly exposed to depleted uranium via other routes such as inhalation, ingestion, and/or wound contamination. To evaluate the presence of depleted uranium in these soldiers eight years later, the uranium concentration and depleted uranium content of urine samples were determined by inductively coupled plasma mass spectrometry in (a) depleted uranium exposed soldiers with embedded shrapnel, (b) depleted uranium exposed soldiers with no shrapnel, and (c) a reference group of deployed soldiers not involved in the friendly fire incidents. Uranium isotopic ratios measured in many urine samples injected directly into the inductively coupled plasma mass spectrometer and analyzed at a mass resolution m/delta m of 300 appeared enriched in 235U with respect to natural abundance (0.72%) due to the presence of an interference of a polyatomic molecule of mass 234.81 amu that was resolved at a mass resolution m/delta m of 4,000. The 235U abundance measured on uranium separated from these urines by anion exchange chromatography was clearly natural or depleted. Urine uranium concentrations of soldiers with shrapnel were higher than those of the two other groups, and 16 out of 17 soldiers with shrapnel had detectable depleted uranium in their urine. In depleted uranium exposed soldiers with no shrapnel, depleted uranium was detected in urine samples of 10 out of 28 soldiers. The median uranium concentration of urines with depleted uranium from soldiers without shrapnel was significantly higher than in urines with no depleted uranium, though substantial overlap in urine uranium concentrations existed between the two groups. Accordingly, assessment of depleted uranium exposure using urine must rely on uranium isotopic analyses, since urine uranium concentration is not an unequivocal indicator of depleted uranium presence in soldiers with no

  9. Detection of depleted uranium in urine of veterans from the 1991 Gulf War.

    PubMed

    Gwiazda, R H; Squibb, K; McDiarmid, M; Smith, D

    2004-01-01

    American soldiers involved in "friendly fire" accidents during the 1991 Gulf War were injured with depleted-uranium-containing fragments or possibly exposed to depleted uranium via other routes such as inhalation, ingestion, and/or wound contamination. To evaluate the presence of depleted uranium in these soldiers eight years later, the uranium concentration and depleted uranium content of urine samples were determined by inductively coupled plasma mass spectrometry in (a) depleted uranium exposed soldiers with embedded shrapnel, (b) depleted uranium exposed soldiers with no shrapnel, and (c) a reference group of deployed soldiers not involved in the friendly fire incidents. Uranium isotopic ratios measured in many urine samples injected directly into the inductively coupled plasma mass spectrometer and analyzed at a mass resolution m/delta m of 300 appeared enriched in 235U with respect to natural abundance (0.72%) due to the presence of an interference of a polyatomic molecule of mass 234.81 amu that was resolved at a mass resolution m/delta m of 4,000. The 235U abundance measured on uranium separated from these urines by anion exchange chromatography was clearly natural or depleted. Urine uranium concentrations of soldiers with shrapnel were higher than those of the two other groups, and 16 out of 17 soldiers with shrapnel had detectable depleted uranium in their urine. In depleted uranium exposed soldiers with no shrapnel, depleted uranium was detected in urine samples of 10 out of 28 soldiers. The median uranium concentration of urines with depleted uranium from soldiers without shrapnel was significantly higher than in urines with no depleted uranium, though substantial overlap in urine uranium concentrations existed between the two groups. Accordingly, assessment of depleted uranium exposure using urine must rely on uranium isotopic analyses, since urine uranium concentration is not an unequivocal indicator of depleted uranium presence in soldiers with no

  10. Uranium mineralization in southern Victoria Land, Antarctica

    SciTech Connect

    Dreschhoff, G.A.M.; Zeller, E.J.

    1986-01-01

    For the past 10 antarctic field seasons, an airborne gamma-ray spectrometric survey has been conducted over widely separated parts of the continent. Localized accumulations of both primary and secondary uranium minerals have been discovered at several localities scattered along the Transantarctic Mountains from the Scott Glacier to northern Victoria Land. A number of highly significant radiation anomalies have been discovered in the area between the Koettlitz Glacier and the Pyramid Trough. The occurrences consist of pegmatite vein complexes which contain an association of primary uranium and thorium minerals. Of still greater significance is the fact that abundant secondary uranium minerals were found in association with the primary deposits, and they indicate clearly that uranium is geochemically mobile under the conditions imposed by the arid polar climate that now exists in southern Victoria Land. Preliminary results of a uranium analysis performed by neutron activation indicate a concentration of 0.12% uranium in a composite sample from the two veins. Even higher levels of thorium are present. The nature of the primary uranium mineralization is currently under investigation. Preliminary results are discussed.

  11. Diffusion and Leaching of Selected Radionuclides (Iodine-129, Technetium-99, and Uranium) Through Category 3 Waste Encasement Concrete and Soil Fill Material

    SciTech Connect

    Mattigod, Shas V.; Whyatt, Greg A.; Serne, R. Jeffrey; Martin, P. F.; Schwab, Kristen E.; Wood, Marcus I.

    2001-09-24

    An assessment of long-term performance of Category 3 waste-enclosing cement grouts requires data about the leachability/diffusion of radionuclide species (iodine-129, technetium-99, and uranium) when the waste forms come in contact with groundwater. Leachability data were collected by conducting dynamic (ANS-16.1) and static leach tests on radionuclide-containing cement specimens. The diffusivity of radionuclides in soil and concrete media was collected by conducting soil-soil and concrete-soil half-cell experiments.

  12. Process for recovering niobium from uranium-niobium alloys

    DOEpatents

    Wallace, S.A.; Creech, E.T.; Northcutt, W.G.

    1982-09-27

    Niobium is recovered from scrap uranium-niobium alloy by melting the scrap with tin, solidifying the billet thus formed, heating the billet to combine niobium with tin therein, placing the billet in hydrochloric acid to dissolve the uranium and form a precipitate of niobium stannide, then separating the precipitate from the acid.

  13. Process for recovering niobium from uranium-niobium alloys

    DOEpatents

    Wallace, Steven A.; Creech, Edward T.; Northcutt, Walter G.

    1983-01-01

    Niobium is recovered from scrap uranium-niobium alloy by melting the scrap with tin, solidifying the billet thus formed, heating the billet to combine niobium with tin therein, placing the billet in hydrochloric acid to dissolve the uranium and leave an insoluble residue of niobium stannide, then separating the niobium stannide from the acid.

  14. Whole-rock uranium analysis by fission track activation

    NASA Technical Reports Server (NTRS)

    Weiss, J. R.; Haines, E. L.

    1974-01-01

    We report a whole-rock uranium method in which the polished sample and track detector are separated in a vacuum chamber. Irradiation with thermal neutrons induces uranium fission in the sample, and the detector records the integrated fission track density. Detection efficiency and geometric factors are calculated and compared with calibration experiments.

  15. Enhanced Control of PWR Primary Coolant Water Chemistry Using Selective Separation Systems for Recovery and Recycle of Enriched Boric Acid

    SciTech Connect

    Ken Czerwinski; Charels Yeamans; Don Olander; Kenneth Raymond; Norman Schroeder; Thomas Robison; Bryan Carlson; Barbara Smit; Pat Robinson

    2006-02-28

    The objective of this project is to develop systems that will allow for increased nuclear energy production through the use of enriched fuels. The developed systems will allow for the efficient and selective recover of selected isotopes that are additives to power water reactors' primary coolant chemistry for suppression of corrosion attack on reactor materials.

  16. The influence of selected parameters on the efficiency and economic charactersistics of the oxy-type coal unit with a membrane-cryogenic oxygen separator

    NASA Astrophysics Data System (ADS)

    Kotowicz, Janusz; Berdowska, Sylwia

    2016-03-01

    In this paper a 600 MW oxy-type coal unit with a pulverized bed boiler and a membrane-cryogenic oxygen separator and carbon capture installation was analyzed. A membrane-cryogenic oxygen separation installation consists of a membrane module and two cryogenic distillation columns. In this system oxygen is produced with the purity equal to 95%. Installation of carbon capture was based on the physical separation method and allows to reduce the CO2 emission by 90%. In this work the influence of the main parameter of the membrane process - the selectivity coefficient, on the efficiency of the coal unit was presented. The economic analysis with the use of the break-even point method was carried out. The economic calculations were realized in view of the break-even price of electricity depending on a coal unit availability.

  17. NICKEL COATED URANIUM ARTICLE

    DOEpatents

    Gray, A.G.

    1958-10-01

    Nickel coatings on uranium and various methods of obtaining such coatings are described. Specifically disclosed are such nickel or nickel alloy layers as barriers between uranium and aluminum- silicon, chromium, or copper coatings.

  18. METHOD FOR PURIFYING URANIUM

    DOEpatents

    Knighton, J.B.; Feder, H.M.

    1960-04-26

    A process is given for purifying a uranium-base nuclear material. The nuclear material is dissolved in zinc or a zinc-magnesium alloy and the concentration of magnesium is increased until uranium precipitates.

  19. Uranium from phosphate ores

    SciTech Connect

    Hurst, F.J.

    1983-01-01

    The following topics are described briefly: the way phosphate fertilizers are made; how uranium is recovered in the phosphate industry; and how to detect covert uranium recovery operations in a phsophate plant.

  20. DIRECT INGOT PROCESS FOR PRODUCING URANIUM

    DOEpatents

    Leaders, W.M.; Knecht, W.S.

    1960-11-15

    A process is given in which uranium tetrafluoride is reduced to the metal with magnesium and in the same step the uranium metal formed is cast into an ingot. For this purpose a mold is arranged under and connected with the reaction bomb, and both are filled with the reaction mixture. The entire mixture is first heated to just below reaction temperature, and thereafter heating is restricted to the mixture in the mold. The reaction starts in the mold whereby heat is released which brings the rest of the mixture to reaction temperature. Pure uranium metal settles in the mold while the magnesium fluoride slag floats on top of it. After cooling, the uranium is separated from the slag by mechanical means.

  1. PREPARATION OF URANIUM HEXAFLUORIDE

    DOEpatents

    Lawroski, S.; Jonke, A.A.; Steunenberg, R.K.

    1959-10-01

    A process is described for preparing uranium hexafluoride from carbonate- leach uranium ore concentrate. The briquetted, crushed, and screened concentrate is reacted with hydrogen fluoride in a fluidized bed, and the uranium tetrafluoride formed is mixed with a solid diluent, such as calcium fluoride. This mixture is fluorinated with fluorine and an inert diluent gas, also in a fluidized bed, and the uranium hexafluoride obtained is finally purified by fractional distillation.

  2. PROCESS OF PURIFYING URANIUM

    DOEpatents

    Seaborg, G.T.; Orlemann, E.F.; Jensen, L.H.

    1958-12-23

    A method of obtaining substantially pure uranium from a uranium composition contaminated with light element impurities such as sodium, magnesium, beryllium, and the like is described. An acidic aqueous solution containing tetravalent uranium is treated with a soluble molybdate to form insoluble uranous molybdate which is removed. This material after washing is dissolved in concentrated nitric acid to obtaln a uranyl nitrate solution from which highly purified uranium is obtained by extraction with ether.

  3. Immobilization of Ag(i) into a metal-organic framework with -SO3H sites for highly selective olefin-paraffin separation at room temperature.

    PubMed

    Chang, Ganggang; Huang, Minhui; Su, Ye; Xing, Huabin; Su, Baogen; Zhang, Zhiguo; Yang, Qiwei; Yang, Yiwen; Ren, Qilong; Bao, Zongbi; Chen, Banglin

    2015-02-18

    Introduction of Ag(i) ions into a sulfonic acid functionalized MOF ((Cr)-MIL-101-SO3H) significantly enhances its interactions with olefin double bonds, leading to its much higher selectivities for the separation of C2H4-C2H6 and C3H6-C3H8 at room temperature over the original (Cr)-MIL-101-SO3H and other adsorbents at room temperature.

  4. Investigation of the particle selectivity of a traveling potential wave; neon isotope separation with the Solitron process. Final report

    SciTech Connect

    Lowder, R.S.

    1994-07-26

    The specific goal of this three year effort was to investigate this novel isotope separation process itself: to determine whether isotopes could indeed be separated and, if so, with what limitations--space charge effects, instabilities, and, in particular, with what throughput limitations. Termed the Solitron process, the concept is based on the strong isotopic variation in wave/ion interaction for a potential wave passing through an ion beam when the wave speed is near the ion speed. The ion`s charge-to-mass ratio determines not only which ions are picked up by the wave but also the final energy of those ions that are picked up (accelerated to a higher energy); thus, this method can be used for isotope separation. Much progress was made regarding separation and throughput, concluding that separation works well in conjunction with electrostatic focusing used to obtain enough throughput (enough beam current) to make a practical device. The next step would likely be a production device, although development of an appropriate metal ion source would be useful. Funding is an issue; development cost estimates run around two million dollars for a market only several times that cost. Although there is much concern about the future supply of isotopes such as could be produced by the Solitron process, as well as costs, at present the supply from Oak Ridge and Russian sources is adequate for US needs. Should demand grow, these LDRD studies would strongly support proposals for further development of this Solitron process and help assure its likely success. For example, a point design for a magnesium mission was formulated to obtain a consistent set of design numbers that would optimize performance without pushing any constraints seen in these studies. A similar design could be formulated for other missions (magnesium was just a convenient target).

  5. Kinetic, equilibrium and thermodynamic studies on sorption of uranium and thorium from aqueous solutions by a selective impregnated resin containing carminic acid.

    PubMed

    Rahmani-Sani, Abolfazl; Hosseini-Bandegharaei, Ahmad; Hosseini, Seyyed-Hossein; Kharghani, Keivan; Zarei, Hossein; Rastegar, Ayoob

    2015-04-01

    In this work, the removal of uranium and thorium ions from aqueous solutions was studied by solid-liquid extraction using an advantageous extractant-impregnated resin (EIR) prepared by loading carminic acid (CA) onto Amberlite XAD-16 resin beads. Batch sorption experiments using CA/XAD-16 beads for the removal of U(VI) and Th(IV) ions were carried out as a function of several parameters, like equilibration time, metal ion concentration, etc. The equilibrium data obtained from the sorption experiments were adjusted to the Langmuir isotherm model and the calculated maximum sorption capacities in terms of monolayer sorption were in agreement with those obtained from the experiments. The experimental data on the sorption behavior of both metal ions onto the EIR beads fitted well in both Bangham and intra-particle diffusion kinetic models, indicating that the intra-particle diffusion is the rate-controlling step. The thermodynamic studies at different temperatures revealed the feasibility and the spontaneous nature of the sorption process for both uranium and thorium ions. PMID:25576783

  6. Kinetic, equilibrium and thermodynamic studies on sorption of uranium and thorium from aqueous solutions by a selective impregnated resin containing carminic acid.

    PubMed

    Rahmani-Sani, Abolfazl; Hosseini-Bandegharaei, Ahmad; Hosseini, Seyyed-Hossein; Kharghani, Keivan; Zarei, Hossein; Rastegar, Ayoob

    2015-04-01

    In this work, the removal of uranium and thorium ions from aqueous solutions was studied by solid-liquid extraction using an advantageous extractant-impregnated resin (EIR) prepared by loading carminic acid (CA) onto Amberlite XAD-16 resin beads. Batch sorption experiments using CA/XAD-16 beads for the removal of U(VI) and Th(IV) ions were carried out as a function of several parameters, like equilibration time, metal ion concentration, etc. The equilibrium data obtained from the sorption experiments were adjusted to the Langmuir isotherm model and the calculated maximum sorption capacities in terms of monolayer sorption were in agreement with those obtained from the experiments. The experimental data on the sorption behavior of both metal ions onto the EIR beads fitted well in both Bangham and intra-particle diffusion kinetic models, indicating that the intra-particle diffusion is the rate-controlling step. The thermodynamic studies at different temperatures revealed the feasibility and the spontaneous nature of the sorption process for both uranium and thorium ions.

  7. Identifying important structural features of ionic liquid stationary phases for the selective separation of nonpolar analytes by comprehensive two-dimensional gas chromatography.

    PubMed

    Zhang, Cheng; Ingram, Isaiah C; Hantao, Leandro W; Anderson, Jared L

    2015-03-20

    A series of dicationic ionic liquid (IL)-based stationary phases were evaluated as secondary columns in comprehensive two-dimensional gas chromatography (GC×GC) for the separation of aliphatic hydrocarbons from kerosene. In order to understand the role that structural features of ILs play on the selectivity of nonpolar analytes, the solvation parameter model was used to probe the solvation properties of the IL-based stationary phases. It was observed that room temperature ILs containing long free alkyl side chain substituents and long linker chains between the two cations possess less cohesive forces and exhibited the highest resolution of aliphatic hydrocarbons. The anion component of the IL did not contribute significantly to the overall separation, as similar selectivities toward aliphatic hydrocarbons were observed when examining ILs with identical cations and different anions. In an attempt to further examine the separation capabilities of the IL-based GC stationary phases, columns of the best performing stationary phases were prepared with higher film thickness and resulted in enhanced selectivity of aliphatic hydrocarbons.

  8. Systematic and practical solvent system selection strategy based on the nonrandom two-liquid segment activity coefficient model for real-life counter-current chromatography separation.

    PubMed

    Ren, Da-Bing; Yi, Lun-Zhao; Qin, Yan-Hua; Yun, Yong-Huan; Deng, Bai-Chuan; Lu, Hong-Mei; Chen, Xiao-Qing; Liang, Yi-Zeng

    2015-05-01

    Solvent system selection is the first step toward a successful counter-current chromatography (CCC) separation. This paper introduces a systematic and practical solvent system selection strategy based on the nonrandom two-liquid segment activity coefficient (NRTL-SAC) model, which is efficient in predicting the solute partition coefficient. Firstly, the application of the NRTL-SAC method was extended to the ethyl acetate/n-butanol/water and chloroform/methanol/water solvent system families. Moreover, the versatility and predictive capability of the NRTL-SAC method were investigated. The results indicate that the solute molecular parameters identified from hexane/ethyl acetate/methanol/water solvent system family are capable of predicting a large number of partition coefficients in several other different solvent system families. The NRTL-SAC strategy was further validated by successfully separating five components from Salvia plebeian R.Br. We therefore propose that NRTL-SAC is a promising high throughput method for rapid solvent system selection and highly adaptable to screen suitable solvent system for real-life CCC separation.

  9. Identifying important structural features of ionic liquid stationary phases for the selective separation of nonpolar analytes by comprehensive two-dimensional gas chromatography.

    PubMed

    Zhang, Cheng; Ingram, Isaiah C; Hantao, Leandro W; Anderson, Jared L

    2015-03-20

    A series of dicationic ionic liquid (IL)-based stationary phases were evaluated as secondary columns in comprehensive two-dimensional gas chromatography (GC×GC) for the separation of aliphatic hydrocarbons from kerosene. In order to understand the role that structural features of ILs play on the selectivity of nonpolar analytes, the solvation parameter model was used to probe the solvation properties of the IL-based stationary phases. It was observed that room temperature ILs containing long free alkyl side chain substituents and long linker chains between the two cations possess less cohesive forces and exhibited the highest resolution of aliphatic hydrocarbons. The anion component of the IL did not contribute significantly to the overall separation, as similar selectivities toward aliphatic hydrocarbons were observed when examining ILs with identical cations and different anions. In an attempt to further examine the separation capabilities of the IL-based GC stationary phases, columns of the best performing stationary phases were prepared with higher film thickness and resulted in enhanced selectivity of aliphatic hydrocarbons. PMID:25698381

  10. PRODUCTION OF URANIUM TETRAFLUORIDE

    DOEpatents

    Shaw, W.E.; Spenceley, R.M.; Teetzel, F.M.

    1959-08-01

    A method is presented for producing uranium tetrafluoride from the gaseous hexafluoride by feeding the hexafluoride into a high temperature zone obtained by the recombination of molecularly dissociated hydrogen. The molal ratio of hydrogen to uranium hexnfluoride is preferably about 3 to 1. Uranium tetrafluoride is obtained in a finely divided, anhydrous state.

  11. Enantiomeric separation of tapentadol by capillary electrophoresis--study of chiral selectivity manipulation by various types of cyclodextrins.

    PubMed

    Znaleziona, Joanna; Fejős, Ida; Ševčík, Juraj; Douša, Michal; Béni, Szabolcs; Maier, Vítězslav

    2015-02-01

    The chiral recognition of the centrally acting analgesic agent tapentadol and its isomers with various cyclodextrins (CDs) was studied by capillary electrophoresis, focusing on the migration order of four stereoisomers. In the case of non-charged hydroxypropylated CDs (2-hydroxypropyl-β-CD, 2-hydroxypropyl-γ-CD) the beta derivative was able to discriminate the S,R- and R,S-isomers in acidic background electrolyte, whereas the gamma allowed the separation of S,S- and R,R-tapentadol, respectively. Dual CD system containing both hosts was used to separate all of four isomers. Negatively charged sulfated-α-CD at 1.0% (w/v) concentration in 100mM sodium borate buffer (pH 9.5) was capable of separating the isomers with favorable enantiomer migration order and the optimized method was able to determine 0.15% of chiral impurities of tapentadol in the presence of the last migrating clinically important R,R-isomer.

  12. TRANSURANIC ELEMENT, COMPOSITION THEREOF, AND METHODS FOR PRODUCING SEPARATING AND PURIFYING SAME

    DOEpatents

    Wahl, A.C.

    1961-09-19

    A process of separating plutonium from fission products contained in an aqueous solution is described. Plutonium, in the tri- or tetravalent state, and the fission products are coprecipitated on lanthanum fluoride, lanthanum oxalate, cerous fluoride, cerous phosphate, ceric iodate, zirconyl phosphate, thorium iodate, or thorium fluoride. The precipitate is dissolved in acid, and the plutonium is oxidized to the hexavalent state. The fission products are selectively precipitated on a carrier of the above group but different from that used for the coprecipitation. The plutonium in the solution, after removal of the fission product precipitate, is reduced to at least the tetravalent state and precipitated on lanthanum fluoride, lanthanum phosphate, lanthanum oxalate, lanthanum hydroxide, cerous fluoride, cerous phosphate, cerous oxalate, cerous hydroxide, ceric iodate, zirconyl phosphate, zirconyl iodate, zirconium hydroxide, thorium fluoride, thorium oxalate, thorium iodate, thorium peroxide, uranium iodate, uranium oxalate, or uranium peroxide, again using a different carrier than that used for the precipitation of the fission products.

  13. Isotope separation

    DOEpatents

    Bartlett, Rodney J.; Morrey, John R.

    1978-01-01

    A method and apparatus is described for separating gas molecules containing one isotope of an element from gas molecules containing other isotopes of the same element in which all of the molecules of the gas are at the same electronic state in their ground state. Gas molecules in a gas stream containing one of the isotopes are selectively excited to a different electronic state while leaving the other gas molecules in their original ground state. Gas molecules containing one of the isotopes are then deflected from the other gas molecules in the stream and thus physically separated.

  14. Remedial action plan and site design for stabilization of the inactive uranium mill tailings sites at Slick Rock, Colorado: Remedial Action Selection Report. Preliminary final

    SciTech Connect

    Not Available

    1994-03-01

    This proposed remedial action plan incorporates the results of detailed investigation of geologic, geomorphic, and seismic conditions at the proposed disposal site. The proposed remedial action will consist of relocating the uranium mill tailings, contaminated vicinity property materials, demolition debris, and windblown/waterborne materials to a permanent repository at the proposed Burro Canyon disposal cell. The proposed disposal site will be geomorphically stable. Seismic design parameters were developed for the geotechnical analyses of the proposed cell. Cell stability was analyzed to ensure long-term performance of the disposal cell in meeting design standards, including slope stability, settlement, and liquefaction potential. The proposed cell cover and erosion protection features were also analyzed and designed to protect the RRM (residual radioactive materials) against surface water and wind erosion. The location of the proposed cell precludes the need for permanent drainage or interceptor ditches. Rock to be used on the cell top-, side-, and toeslopes was sized to withstand probable maximum precipitation events.

  15. Volatile fluoride process for separating plutonium from other materials

    DOEpatents

    Spedding, F. H.; Newton, A. S.

    1959-04-14

    The separation of plutonium from uranium and/or fission products by formation of the higher fluorides off uranium and/or plutonium is described. Neutronirradiated uranium metal is first converted to the hydride. This hydrided product is then treated with fluorine at about 315 deg C to form and volatilize UF/sub 6/ leaving plutonium behind. Thc plutonium may then be separated by reacting the residue with fluorine at about 5004DEC and collecting the volatile plutonium fluoride thus formed.

  16. VOLATILE FLUORIDE PROCESS FOR SEPARATING PLUTONIUM FROM OTHER MATERIALS

    DOEpatents

    Spedding, F.H.; Newton, A.S.

    1959-04-14

    The separation of plutonium from uranium and/or tission products by formation of the higher fluorides of uranium and/or plutonium is discussed. Neutronirradiated uranium metal is first convcrted to the hydride. This hydrided product is then treatced with fluorine at about 315 deg C to form and volatilize UF/sup 6/ leaving plutonium behind. The plutonium may then be separated by reacting the residue with fluorine at about 500 deg C and collecting the volatile plutonium fluoride thus formed.

  17. Product separator

    DOEpatents

    Welsh, Robert A.; Deurbrouck, Albert W.

    1976-01-20

    A secondary light sensitive photoelectric product separator for use with a primary product separator that concentrates a material so that it is visually distinguishable from adjacent materials. The concentrate separation is accomplished first by feeding the material onto a vibratory inclined surface with a liquid flow, such as a wet concentrating table. Vibrations generally perpendicular to the stream direction of flow cause the concentrate to separate from its mixture according to its color. When the concentrate and its surrounding stream reach the recovery end of the table, a detecting device notes the line of color demarcation and triggers a signal if it differs from a normal condition. If no difference is noted nothing moves on the second separator. However, if a difference is detected in the constant monitoring of the color line's location, a product splitter and recovery unit normally positioned near the color line at the recovery end, moves to a new position. In this manner the selected separated concentrate is recovered at a maximum rate regardless of variations in the flow stream or other conditions present.

  18. 31 CFR 540.317 - Uranium feed; natural uranium feed.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Uranium feed; natural uranium feed... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed....

  19. 31 CFR 540.317 - Uranium feed; natural uranium feed.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Uranium feed; natural uranium feed... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed....

  20. 31 CFR 540.317 - Uranium feed; natural uranium feed.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Uranium feed; natural uranium feed... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed....