«XVIII МЕНДЕЛЕЕВСКИЙ СЪЕЗД ПО ОБЩЕЙ И ПРИКЛАДНОЙ ХИМИИ Москва, 23–28 сентября 2007 г. ТЕЗИСЫ ДОКЛАДОВ Москва – 2007 УДК ...»
ХVIII Менделеевский съезд по общей и прикладной химии, Москва, 2007 INTERACTION OF TRITIUM WITH OILS AND TRITIATED WASTE OIL DECONTAMINATION Sazonov A.B., Veretennikova G.V., Magomedbekov E.P.
D. Mendeleyev University of Chemical Technology of Russia 9-th Miusskaya sq., Moscow, 125047, Russia The international thermonuclear fusion program is assumed to deal with kilograms of tritium. For all the methods of tritium production, purification, transportation, measurement etc. its chemical interaction with organic substances (rubber, plastics, pump fluids) caused by the radioactive decay is common. To reduce tritium disposal into the environment searching the ways of organic tritiated waste processing and design of readily utilized synthetic materials are the actual problems of fu sion-related applied chemistry.
Mineral and synthetic oils used as lubricants or operating fluids in vacuum pumps are the com plicated mixtures of branched or cyclic saturated hydrocarbons. These substances are chemically inert but their slow partial oxidation is possible even at room temperature. As it was proven by practice specific activity of waste tritiated oils may exceed 1000 Ci/kg. The techniques for utiliza tion of such radioactive wastes are not developed enough.
Our studies of waste oils being in contact with gaseous tritium for a long time show that more than 90% of the radionuclide is bound with oxidation products. The majority of tritiated species are the molecules with relatively large molecular mass containing polar functional groups. Concentra tion of volatile tritiated compounds formed as a result of radiation-induced degradation is not so significant. The selectivity of tritium interaction is owned to the predominant formation of quasi free tritons or HeT+ ions when one of the two nuclei in the T2 molecule decays. It is assumed that the sequence of ion-molecule triton transport reactions is the mechanism responsible for accumula tion of tritium by hydrocarbon oxidation products with high proton affinity. Condensation of T2O in oils may be an additional source of their contamination.
The most effective technique of mineral pump oil decontamination was found to be the adsorp tion of tritiated species by solid polar adsorbents (silica gel, alumina gel, zeolites). Detritiation de gree for these adsorbents amounts to 95%. Then the complete thermal oxidative destruction of ad sorbed fractions can be used to convert organic compounds into carbon dioxide and water, the latter is reduced to hydrogen gas enriched with tritium. Adsorption of the tritiated compounds, thermal oxidation and adsorbent regeneration may be considered as the technology of tritium recycling since HT can be returned to the isotope separation system. As a result, the radiation danger related with the storage of high activity waste oils can be significantly decreased.
2536 ХVIII Менделеевский съезд по общей и прикладной химии, Москва, ROLE OF BACTERIA FOR DECONTAMINATION OF WASTES FROM NUCLEAR FUEL CYCLE Shapovalova A.A., Khijniak T.V.
Winogradsky Institute of Microbiology of RAS 7/2, prospect 60-letiya Oktyabrya, Moscow, 117312 Russia.
During reprocessing of nuclear wastes in addition to radioactive material a big amount of non radioactive products are accumulated – nitrates, sulphates, carbonates and others. These “concomi tant” wastes also influence the environment due to modification of redox conditions, and as a con sequence the floral and microbial community. Physico-chemical and biotechnological treatments are applicable for such wastes. Bacterial biotechnology has advantages as long as waste compacting could occur in the wide range of conditions (pH, salinity, temperature).
In the laboratory of ecology and geochemical activity of microorganisms (INMI RAS) 17 strains of alkaliphilic heterotrophic bacteria Halomonas sp. were collected from different regions of the world (Egypt, Mongolia, Kulunda/Russia, Mono Lake/USA). A wide range of substrates was inves tigated for bacterial utilization1. Also it was shown that isolates were capable to reduce nitrate, chromate, selenite, selenate and pertechnetate2 under alkaline conditions (pH 8-11). Specific nitrate reductase was isolated from some Halomonas strains;
reduction of nitrates to gaseous nitrogen was observed as a result of this specific enzyme.
In the mean time, kinetic characteristic of chromate, nitrate and selenite reduction are under in vestigation.
We believe, that haloalkaliphilic heterotrophic bacteria are perspective for development of bio technological decontamination of low-active nuclear waste, because these organisms are able to utilize wide range of organic substrates and resistant to high salt concentration.
This work supported by the program “Molecular and Cell Biology” of the Russian Academy of Sciences and in part by RFBR №04-04-48602.
References 1. Shapovalova A.A., Khizhnyak T.V. Reduction of toxic oxi-anions in the high-alkaine salt media by bacteria Halo monas. / Intrnational youngh school-conference «Actual aspects of modert microbiology, November 1-3, 2006, Mos cow, Ab-stracts, P. 40-42.
2. Khijniak T.V., Medvedeva-Lyalikova N.N., Simonoff M. Reduction of pertechnetate by haloalkaliphilic strains of Halomonas. FEMS Microbiology Ecology, 2003, 44/1, p.109-115.
ХVIII Менделеевский съезд по общей и прикладной химии, Москва, 2007 METHOD OF TRITIUM BETA-DECAY FOR INVESTIGATIONS OF ELECTROPHILIC REACTION MECHANISMS WITH THE POLYCENTRAL SYSTEM OF BIOLOGICALLY ACTIVE NITROGEN HETEROCYCLIC DERIVATIVES Shchepina N.E.a, Avrorin V.V.b, Badun G.A.c, Fedoseev V.M.c, Ukhanov S.E.d, Lewis S.B.e a Natural Sciences Institute Perm State University, 4 Genkel St., Perm, 614990, Russia b Lomonosov Moscow State University, Leninskie Gory, Moscow, 119992, Russia c St-Petersburg State University,26 Universitetsky Pr., St-Petersburg, Petrodvorets, 198504, Russia d Perm Technical University, 29a Komsomolsky Pr., Perm, 614600, Russia e James Madison University Harrisonburg, 22807 VA USA Hence to the generation of free tritium labeled phenyl cations during the beta-decay processes and further ion-molecular reactions with the different nitrogen heterocyclic derivatives the detailed in vestigations of mechanisms of undergoing electrophilic interactions with polycentral system of se ries biologically active pyridine, picoline, quinoline and quinaldine compounds have been carried out:
R R AdE X X R N+ N+ C6H4T C6H4T N C6H4T R CH2C6H4T SE + C6H4T+ ;
N N AdE X- X R R R N+ N+ N C6H4T C6H4T C6H4T C6H4T R;
R N SE N R = H, CH3;
X- = BF4- CH2C6H4T N The investigations were carried out under the support of RFBR grant № 07-03- 2538 ХVIII Менделеевский съезд по общей и прикладной химии, Москва, SEQUESTRATION ABILITY OF HUMIC COATINGS DIFFERING IN CARBOXYL CONTENT WITH RESPECT TO ACTINIDES Shcherbina N.S.ab, Perminova I.V.a, Karpiouk L.A.a, Kalmykov S.N.a, Ponomarenko S.A.c a Lomonosov Moscow State University, Chemistry Department, Moscow 119992, Russia b Vernadsky Institute of Geochemistry and Analytical Chemistry, RAS, Moscow 119991, Russia c Institute of Synthetic Polymer Materials, RAS, Moscow 117393, Russia Humic Substances (HS) are ubiquitous in the environment. They possess a broad spectrum of func tional groups and can take part in different interactions with metal ions like redox transformation or complexation. Due to these interactions, HS could strongly affect actinides migration in the envi ronment1,2. This work proposes new technology that uses soluble HS which are further immobilized onto surface of silica gel to produce a reactive phase or sorbent for metal sequestration. The proof of principle of this technology was demonstrated in our previous publication3 that has shown an in crease in sequestration ability of humic coatings covalently bound to silica gel with respect to highly mobile Pu(V)O2+ and Np(V)O2+ as compared to SiO2. The goal of this work was to test se questering abilities of humic coatings obtained by immobilization of alkoxysilylated derivatives with different modification degree, that is, with varying amount of remaining carboxyl group which are being derivatized during incorporation of alkoxysilyl-groups into humic backbone.
Parent leonardite material (CHP) was used to prepare alkoxysilyl-derivatives (HA-APTS) with modification degree 20, 50, and 100%,4 and then, HA-APTS derivative was immobilized into silica gel (HA-APTS-SiO2). A number of derivatives with different content of carboxylic groups were prepared in order to estimate role of carboxylic sites in actinide-HS interaction process.
It was demonstrated that the ratio of Pu(V) bound to humic derivatives immobilized onto silica gel increased with the time until the quantitative Pu(V) sorption occurred. This was much higher as compared to that for Np(V). Equilibration in the system with Np(V) was established during 1-1. days, while for Pu(V) it took almost 5 days. We suppose that this was caused by Pu(V) reduction upon sorption, while Np(V) remained in the pentavalent form during the whole exposure time. Ki netics of Pu(V) sorption was pH-dependent. It was shown that the rate of Pu(V) sorption onto sam ples with different content of carboxyl groups increased with an increase in the carboxyl content or a decrease in modification degree of the immobilized derivative. This demonstrates a key role of carboxyl groups in actinide complexation. The optimum modification degree providing for both high mineral-affinity and sequestration ability was around 20%.
The research was supported by US DOE (project RUC2-20006).
References 1. Takahashi, Yo, et al. Formation of actinide (III)-humate and its influence on adsorption on kaolinite. Mat. Res. Soc.
Proc., Vol. 353, pp. 205-212 (1995).
2. Moulin V. Impact of humic substances on speciation of heavy metals and organic xenobiotics: implicatios for bioro modiation technologies. In: Use of humic substances to remediate polluted environments: from theory to practice, Ch. 7, P. 155-173 (2003) 3. Perminova, I.V., Karpiouk, L.A., Shcherbina, N.S., Ponomarenko, S.A., Kalmykov, St.N., Hatfield, K. Preparation and use of humic coatings covalently bound to silica gel for Np(V) and Pu(V) sequestration J. All. Com. In press http://dx.doi.org/10.1016/j.jallcom.2007.01.089 (2007).
4. Perminova I.V. et al.,Humic derivatives, methods of preparation and use. PCT application RU2006/000102.filed on March 7 (2006).
ХVIII Менделеевский съезд по общей и прикладной химии, Москва, 2007 [11C-METIL]-METHIONINE – RADIOPHARMACEUTICAL FOR PET:
AUTOMATED MODULE FOR RADIOCHEMICAL SYNTHESIS Silchenkov A.V.a, Kuznetsov M.A.a, Tuflina T.V.a, Pakhomov G.A.b, Shimchuk G.G.b, Shimchuk G.G.b a Bakulev Scientific Center for Cardiovascular Surgery, 135, Rublevskoe sh.,121552, Moscow, b Alikhanov Theoretical and Experimental Physics Institute, 25, B.Cheremushkinskaya, 117218, Moscow [11C]-methionine, well known [11C]-radiopharmaceutical, is widely used for PET diagnostics of brain tumors. Traditionally radiopharmaceuticals of routine clinical application are produced on the remote controlled synthesis units which are rather expensive.
Automated module for [11C]-methionine synthesis worked out in Moscow is less expensive than its commercial analogs. The main advantage of this apparatus is full automation of both synthetic and module preparation stages. It means that [11C]-methionine could be synthesized few times in series without manual operations between production cycles.
Technological scheme of synthesis based on reaction of L-homocysteine with [11C]-methyl io dide includes purification of final product by solid phase extraction. Some stages of technological process are combined to minimize the number of executive elements (reaction vessels, valves, etc.) and increase the reliability of the whole unit.
Using of Peltier elements for temperature changes (temperature range –20 +120 C) is rather new for such kind of apparatus. Small-size radioactivity detectors and original software are the other features of this synthesis unit.
The synthesis of [11C]-methionine takes about 15 minutes, module cleaning and preparation for the next synthesis typically requires 20 minutes.
The yield of product depends on reaction temperature and time, reagents concentration, shape and material of reaction vials etc. The methodic of synthesis on the module developed was worked through according to experimental results for these dependences.
40 test syntheses (in series of 4) with average product yield of 31±5% (not decay-corrected) were executed using this automated module. Radiochemical purity of product was more than 96%.
This work was supported by Grant from the Government of Moscow.
2540 ХVIII Менделеевский съезд по общей и прикладной химии, Москва, CHEMICAL AND ELECTROCHEMICAL BEHAVIOR OF ZIRCONIUM IN FUSED LITHIUM AND POTASSIUM CHLORIDES EUTECTIC Smolenski V.
The chemical and electrochemical behavior of zirconium compounds in fused LiCl-KCl was car ried out. The voltammetry investigation shows that the reduction of zirconium ions to the solid state is irreversible and controlled by the rate transferred charge. The constant (K°fh) of the cathodic reac tion was calculated. In the case of a presence the zirconium metal in the electrolyte the considerable part of the soluble species exists in the oxidation level +2.
Volatility of the tetravalent zirconium chloride and the mixture of the tetra- and divalent zirco nium chlorides in non-equilibrium conditions have been studied. It was shown that the increase of the temperature and total zirconium concentration lead the growth of volatility. The main results of the experiments are explained from the position of the acid-base general theory of Lewis. The re ceived data are of considerable interest to technology process of recovery spent fuel of fast reactor.
The chemical properties of zirconium chlorides have been studied using the electrochemical cell with two YZME electrodes with a solid electrolyte membrane based on zirconium dioxide stabi lized with one-and-a-half oxide of yttrium (dmc2 France S.A.). The first is used as pO2- indicator electrode and another as an oxygen pump. The monitoring of two types YZME indicator electrodes was investigated. The time of their activation in the melt under test was founded. Titration of Zr(IV) chlorocomplex by O2- demonstrated the precipitation of ZrOCl2 and ZrO2. These data allowed us to draw Pourbaix type diagram which gives reactivity zones to the precipitation and solubility of metal oxychloride and oxide. These data are important for conceiving the skeletal structure of a new py rochemical process.
Acknowledgements. This work is part of the work performed at CEA within the project of the European Commis sion.
ХVIII Менделеевский съезд по общей и прикладной химии, Москва, 2007 DEVELOPMENT OF NEW TECHNOLOGY FOR CLEANING OF COMPONENTS OF FAST REACTORS FROM NON-DRAINED SODIUM RESIDUES BY THEIR NEUTRALIZATION WITH NITROUS OXIDE Smykov V.B., Loukianov A.A., Kryuchkov E.A.
State Scientific Center of the Russian Federation “Institute of Physics and Power Engineering named after A. Leipunsky” (IPPE), Obninsk Neutralization of non-drained residues of nuclear reactor liquid metal coolant (Na) in the circuits, vessels and cold traps is the main problem on the stage of decommissioning of NPP with fast reactors. In addition to available methods of neutralization of these residues, it was proposed by the SSC RF – IPPE specialists to use nitrous oxide N2O for this purpose.
Experimental studies were carried out on the mechanism of sodium interaction with nitrous oxide, and the main results are as follows:
• Temperature of Na – N2O interaction onset is 220–230°С, but the rate of interaction is low, tempera ture effect is hard to measure, and interaction is indicated by the appearance of insignificant amount of nitrogen (2-3 vol.%) in N2O atmosphere. At higher temperatures (250–270°С), interaction intensifies, and temperature effect, which is significant at the very beginning of the process (90–110°С), becomes much lower with the time. No hydrogen generation occurs.
• The main primary interaction of sodium and nitrous oxide is oxidation-reduction reaction producing sodium hyponitrite:
2 Na + N2O Na2O + N2.
• With sodium spending and sodium oxide accumulation, direct combination reaction resulting in pro duction of sodium hyponitrite becomes significant:
Na2O + N2O Na2N2O2.
• During heating up to 320-330oC sodium hyponitrite is decomposed with formation of sodium ni trite, nitrate and sodium oxide:
7 Na2N2O2 NaNO3 + 3 NaNO2 + 5 Na2O + 5N2.
Treatment of the oxide product by nitrous oxide for a long time results in deeper oxidation of sodium to nitrite and nitrate. Peroxides formation was not revealed.
• It was revealed that the products of Na interaction with N2O have porous, and, sometimes, friable structure, and no gas-impermeable layer is formed. Therefore, with the excess of N2O, reactions con tinue till the end. Porosity of the product of Na interaction with Na2O is caused mainly by issuing of inert nitrogen. This fact is very important from the standpoint of chemistry and technology, since natu ral spontaneous access of fresh nitrous oxide is assured to underoxidized sodium. In our opinion, this is the main advantage of the use of nitrous oxide as compared to the other oxidizing gases.
• It has been determined that N2O interacted with sodium hydride NaH at 135°C temperature with for mation of NaOH and release of N2 as described by the following equation:
NaH + N2O NaOH + N2.
Apparently, this result might be very important in case of use of N2O for neutralization of sodium resi dues in the cold traps, where tritium is bound to sodium tritide NaT. Conversion of tritium to chemically more stable compound NaOT prevents its release to the gas phase and to the environment. It was also re vealed that N2O did not interact with sodium hydroxide NaOH.
• When the product oxide containing Na2N2O2 is dissolved in water, nitrous oxide is released to the cover gas, as described by the following equation:
Na2N2O2 + H2O 2 NaOH + N2O.
The rest of products of N2O interaction with Na are also readily soluble in water without hydrogen pro duction and can be removed from the components in the process of washing by water.
Work has been carried out on the development of methods of control of the process of sodium neutraliza tion by nitrous oxide in the liquid metal circuit. The trials has been carried out at the equipment of secondary circuit of fast reactor BR-10 in IPPE.
2542 ХVIII Менделеевский съезд по общей и прикладной химии, Москва, DEVELOPMENT OF THE METHODS RECYCLING OF THE PRECIOUS METALS CONTAINING IN PRODUCTS OF PROCESSING OF NUCLEAR FUEL Suvorova V.A., Tikhomirova V.I.
Institute of experimental mineralogy (IEM RAS), 142432, the Moscow region, Cernogolovka, street Institute, The opportunity of branch of precious metals from other weight of radionuclides and constructional materials from liquid nitrate waste products of processing of nuclear fuel was investigated. It is executed for a palladium and a rhodium, components in waste products radioactive nuclides, re spectively, 0.29 and 0.68% in recalculation on the dry rest. Conditions of quantitative precipitation Pd(II) and Rh(III) oxidized forms thiourea (Thio) from nitrate (3-4 М HNO3) liquid waste products radionuclides are investigated.
Palladium. The solutions Pd(II) (concentration 12 mg·ml-1 on 6 M HNO3) were prepared by dissolution of metal (analytical grade) in nitric acid. Thio (analytical grade) was used as in a dry kind and dissolved in 0.023.00 M HNO3. Precipitation Pd(II) from solutions of nitric acid (3-4 M) passes through formation of forms Thio oxidized by a nitrogenous acid.
Results of experiments at initial parity Pd(II):Thio = 1:6 show, that irrespective of concentration HNO3 and duration of contacts of nitrate solution Pd(II) with solutions Thio nuclear maintenance Pd in precipitations considerably exceeds those for sulfur. Full formation of precipitations is reached in 5-7 day.
IRS and XRD data of products indicate the formation of a complex [Pd2(CN)4]·H2O which turns out as a result of interaction aqua-acydo-complex a palladium with products of transformation Thio in HNO3 environment. After calcinations at 500-6000C connection decays up to pure powder-like metallic Pd.
Rhodium. The solution of complex nitrate Rh(III), TU 6-09-05-1431-90 with a mass fraction of rhodium of 29.5% was used for preparation of solutions for various concentration. Precipitation of connections Rh(III) was spent to 2 stages.
I stage. Precipitation of the basic amount of rhodium was carried out from the concentrated solu tions (concentration Rh(III) = 15 mg·ml-1 in 3 M HNO3). nitrate solution Thio having ratio Rh(III):Thio = 1:6 was added to a researched solution. Ratio Rh:S in a product was about 1:3. Or ange color of a precipitation and their composition correspond to compound Rh(SCN)3. However the same color and structure of a filtrate indicated presence at it Rh(III). It meant incomplete pre cipitation of rhodium from a researched solution.
II stage. Stayed rhodium took out with help S-dioxides Thio – (NH2)2CSO2, synthesized with the help of peroxide of hydrogen1.
For quantitative precipitation of rhodium to 100 ml of a solution of nitrate Rh(III) containing mg Rh in 0.3 M HNO3 diluted up to concentration, added 100 mg of S-dioxides Thio. Contents Rh(III) in a filtrate 4.1·10-5 g (0.7% from initial amount). Thus, there is practically full precipita tion of stayed rhodium. The precipitation received in experiment at surplus of a reagent, has given gross-formula RhC4.4N7.63S6.00H20.57O9.22. Obviously, the aggregate complex which formula can be presented as Rh[(NH2)2CSO2]3·4H2O·SC(NH2)2 is formed. After calcinations at the presence of coal by known technique2 the precipitation can be restored up to metallic rhodium.
References 1. E. de B. Barnett, J. Chem. Soc. 1910, 97, 64.
2. N.K. Pshenitsyn, I.V. Prokofeva, A.E. Bukanova, J. of Analyt. Chem. (USSR) 1963, XVIII, Rel. 6, 763.
ХVIII Менделеевский съезд по общей и прикладной химии, Москва, 2007 X-RAY PHOTOELECTRON SPECTROSCOPY STUDY OF THE PRODUCTS OF INTERACTION OF GASEOUS IrF6 WITH FINE UO2F2 AT 125°C Teterin A.Yu., Maslakov K.I., Teterin Yu.A., Ivanov K.E., Trotsenko N.M., Prusakov V.N., Bochagin F.S.
RRC “Kurchatov Institute”, 1, Kurchatov square, Moscow, Russia The gas-fluorite (“dry”) technology of regeneration of the spent nuclear fuel (SNF) uses uranyl fluorite (UO2F2) for selective isolation of plutonium from gaseous mixtures1. Since plutonium re quires special treatments, IrF6 was used as a thermodynamic model of PuF6. This compound is as reactive and volatile as PuF6. Nevertheless, the experiments on the study of interaction of PuF6 with UO2F2 have to be done and are scheduled on the nearest future.
This work carried out the X-Ray photoelectron spectroscopy study of the initial uranyl fluorite (UO2F2, TNM-0) and five samples (TNM-5 – TNM-1) of the products of interaction of gaseous IrF and fine UO2F2 in order to establish the quantitative elemental composition and to determine irid ium and other metals oxidation states. These samples reflect the contents of the fractionator filled with UO2F2 on different heights (TNM-5 – TNM-1) during the IrF6 blow-through. As a result, the quantitative compositions of the surfaces of the studied samples relative to uranium were estab lished:
U1.00O1.97F2.33C0.41 (TNM – 0) U1.00O2.09F2.17Ir0.03C0.69 (TNM – 1) U1.00O1.85F2.11Ir0.10C0.28 (TNM – 2) U1.00O1.61F1.90Ir0.07C0.37 (TNM – 3) U1.00O2.90F2.53Ir0.23C0.91+0.14 (TNM – 4) U1.00O2.14F1.95Ir0.11C0.63 (TNM – 5) In the low binding energy XPS range (Eb =2.4 eV) an intense Ir5d peak attributed to the weakly bound Ir5d electrons was observed. The intensity of this peak is proportional to the iridium concen tration on the sample surface. This peak is absent in the XPS from UO2F2 (TNM-0). As it follows from the data on the Ir4f binding energy (Eb = 62.7 эВ), iridium oxidation state in the studied sam ples is close to Ir3+. The study showed that the interaction of gaseous IrF6 with fine UO2F2 at 125°C results in formation of the stable iridium compounds where iridium oxidation state is close to Ir3+.
Also, the dependence of the elemental compositions of the layers in the fractionator on the penetra tion depth of IrF6 was established.
This work was supported by the Fund for Support of the Domestic Science 2007, the Fund of the RF President for the Leading Scientific Schools (NSh-284.2006.3).
References 1. D. Amano, F. Kawamura, T. Fukasawa, M. Takahashi, A. Sasahira, Y. Shibata, J. Ymashita, New Reprocessing Technology, Fluorex, For LWR Fuel Cycle-Hybrid Process of Fluoride Volatility and Solvent Extraction, Interna tional Conference “Back-End of the Fuel Cycle”, Global, Paris, Sept. 2001.
2. Teterin Yu.A., Teterin A.Yu., Russian Chemical Review, 2004, 73, 6, 588.
2544 ХVIII Менделеевский съезд по общей и прикладной химии, Москва, X-RAY PHOTOELECTRON SPECTROSCOPY STUDY OF THE UO2+X SURFACE STOICHIOMETRY Teterin Yu.A.a, Teterin A.Yu.a, Maslakov K.I.a, Batuk O.N.b, Kalmykov S.N.b, Petrov V.G.b, Zakharova E.V.c a RRC “Kurchatov Institute”, 1, Kurchatov square, Moscow, Russia b Chemical dept. of M.V. Lomonosov MSU, Lininskie Gory, Moscow, Russia c A.N. Frumkin Institute of Physical Chemistry and Electrochemistryof RAS, Moscow, Russia Determination of uranium oxidation states in oxides is critical since uranium dioxide is the basic component of the uranium ore and the spent nuclear fuel (SNF). Uranium oxidation state is respon sible for the solubility of uranium compounds and, hence, is a key parameter in uranium deposition processing and environment risk evaluation during the SNF storage areas design. The study and modeling of uranium oxides dilution considers the processes on the solution/surface interface.
Therefore, the solubility of uranium compounds is determined by the UO2+x stoichiometry in this interface. X-Ray photoelectron spectroscopy (XPS) allows the information from the sample surface (5-10 nm) layer on the stoichiometry and the valency of the included elements.
This work was done in order to determine the oxygen coefficient х in uranium oxides UO2+x in the range 0х 1 and to study their stoichiometric compositions. The techniques of determination of the elemental and ionic compositions as well as uranium close environment structure in UO2+x developed on the basis of the fine XPS structure parameters of the core and outer electrons were considered1,2. In the present time these techniques are physically grounded both theoretically and experimentally3,4. The proposed techniques allow the determination of the oxygen coefficient (2+ х) in UO2+x in the range 0х 1 on the basis of the U5f relative intensity. It has to be noted that the determination of the oxygen coefficient on the basis of the core U4f and O1s intensities is compli cated because of the uncontrolled oxygen excess on the surface of the studied oxides. The U5f rela tive intensity yields the information on the ratio of the valence forms, e.g. U(IV)/U(VI), on the sur face. Only in individual cases this information can be drawn on the basis of the core U4f XPS struc ture parameters. Uranium oxidation states can be also determined on the basis of the parameters of the U4f shake up satellites. The fine XPS structure parameters of the inner valence molecular orbi tals in the binding energy range 13-40 eV allow the evaluation of the interatomic distances in the uranyl group and in the equatorial planes of uranyl compounds.
This work was supported by the Fund for Support of the Domestic Science 2007, the Fund of the RF President for the Leading Scientific Schools (NSh-284.2006.3).
References 1. Teterin Yu.A., Kulakov V.M., Baev A.S. et al., DAN SSSR, 1980, 255, 2, 434.
2. Teterin Yu.A., Kulakov V.M., Baev A.S. et al., Phys. Chem. Minerals, 1981, 7, 151.
3. Teterin Yu.A., Ryzhkov M.V., Teterin A.Yu et al., Radiochemistry, 2002, 44, 3, 206.
4. Teterin Yu.A., Maslakov K.I., Ryzhkov M.V., et al., Radiochemistry, 2005, 47, 3, 193.
ХVIII Менделеевский съезд по общей и прикладной химии, Москва, 2007 THE LEWIS ACID INFLUENCE ON PROPERTIES OF URANYLCONTAINED LASER SOLUTIONS BASED ON PHOSPHORUS OXYCHLORIDE Tikhonov G.V., Kabakov D.V., Kiselev S.V., Seregina E.A.
State Scientific Centre of the Russian Federation – Institute for Physics and Power Engineering named after A.I.Leypunsky, Obninsk Aprotic solvents activated by neodymium and uranyl ions are of considerable interest as active me dia for direct transformation of nuclear fission energy into coherent electromagnetic radiation. It is shown that the distinctions in the spectral-luminescent and laser properties of POCl3-MClx UO22+-Nd3+ solutions are caused by different chemical affinity of the elements to oxygen, first of all.
1. The affinity to oxygen Mx+ (M: Zr, Ti, Si, B and Al) is more, than the affinity to oxygen U6+.
The absorption stripes of OH-groups are registered in near IR-area of spectra of uranyl-containing POCl3-MClx solutions. At the storage of the solutions the intensity of the absorption stripes of OH groups increases, and the Nd3+ fluorescence lifetime reduces.
2. The affinity to oxygen Mx+ (M: Sn, Sb and Bi) is less, than the affinity to U6+. Uranyl di chlorophosphate UO2(PO2Cl2)2 is formed during synthesis of uranyl-containing POCl3-MClx solutions, therefore U(IV) is appeared:
UO2(PO2Cl2)2 + 2POCl3 U(PO2Cl2)4 + Cl2.
U(IV) absorbs the optical radiation on the wavelength of the Nd3+ laser transition 4F3/2 4I11/2 = 1,05 m with molar absorption coefficient 21±2 lmol-1sm-1.
The kinetic dependences of U(IV) accumulation in uranyl-containing POCl3-SnCl4 and POCl3 SbCl5 solutions are received during their synthesis, during heating, in the time of long storage and using an irradiation by the Xe-lamps light of tightly sealed-in samples. The rate of U(IV) accumula tion increases with increase in UO22+ and Nd3+ concentrations. During synthesis (T = 380 K) k2[U4+] (3±1).10-5 lmol-1s-1 in POCl3-SnCl4-235UO22+-Nd3+ and k2[U4+] (1.5±0.4).10-5 lmol-1s- in POCl3-SbCl5-235UO22+-Nd3+.
The Nd3+ fluorescence lifetime reduces owing to intracomplex non-radiative transfer of the exci tation energy Nd3+ U4+. The quenching rate constant of Nd3+ fluorescence was evaluated by the Stern-Volmer relation: kq (8.4±1.7).105 lmol-1s-1 in POCl3-SnCl4-235UO22+-Nd3+ and kq (6.4±0.6).105 lmol-1s-1 in POCl3-SbCl5-235UO22+-Nd3+.
3. The radiation-chemical yield of Nd3+ in the exited state 4F3/2 in POCl3-MClx-235UO22+-Nd3+ solutions upon homogeneous excitation by uranium -particles increases with decreasing of the af finity to oxygen of the central ion of Lewis acid and has the greatest values in laser POCl3-SbCl5 UO22+-Nd3+ and POCl3-SnCl4-235UO22+-Nd3+ liquids: respectively, 2.20±0.24 and 1.68±0.10 ex cited ions per 100 eV at [Nd3+] = 0.4 mol/l.
The synthesis method is developed and the samples of a new highly effective laser POCl3-SbCl5 UO22+-Nd3+ liquid with the characteristics which are necessary for researches of direct transfor mation of nuclear fission energy to laser emission energy are made.
This research was supported by the Russian Foundation for Basic Research and the Government of the Kaluga re gion (project № 07-03-96412).
2546 ХVIII Менделеевский съезд по общей и прикладной химии, Москва, SOLUBILITY OF URANIUM, NEPTUNIUM AND PLUTONIUM DIOXIDES IN SIMULATED GROUNDWATER SOLUTIONS UNDER DIFFERENT CONDITIONS Trofimov T.I., Kulyako Yu.M., Perevalov S.A., Malikov D.A., Myasoedov B.F.
V.I. Vernadsky Institute of Geochemistry and Analytical Chemistry RAS. Moscow Solubility of powder-like UO2, NpO2 and PuO2 in simulated groundwater solutions (SGW) was studied by the method of achieving equilibrium “from below”. The experimental data on solubility of the dioxides were obtained with the use of heterogeneous systems “AnO2-SGW” for different weight ratios of solid and liquid phases at various pH values under both ambient and inert condi tions. It was established that solubility values of UO2, NpO2 and PuO2 depend on phase ratio in the heterogeneous systems under study but they do not depend on pH values of the solution within pH range of 6 – 11. The solubility values of UO2 and NpO2 in SGW under ambient conditions turned out to be higher than the respective values found in inert atmosphere, while solubility of freshly cal cined PuO2 did not depend practically on the environmental conditions. Oxidizing processes pro ceeding on the dioxide surface, which is proportional to the dioxide mass, result in the formation of more soluble amorphous hydroxide phases controlling finally the dioxide solubility.
The work was supported by Russian Foundation for Basic Research, grant # 06-03-32067a.
ХVIII Менделеевский съезд по общей и прикладной химии, Москва, 2007 FACTORS, DETERMINING PLUTONIUM(IV) OCCURRENCE FORMS IN SOLUTIONS Trofimov T.I., Kulyako Yu.M., Perevalov S.A., Malikov D.A., Myasoedov B.F.
V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry, RAS 119991, GSP-1, Moscow, V-334, Kosygin street, It was shown that as a result of precipitation of Pu(III) and Pu(IV) hydroxides Pu(OH)4 is obtained in the «mixed» form. Hydrolyzed monomeric or weakly polymerized form of Pu(IV) dominates in freshly precipitated Pu(OH)4. The second form is highly polymerized Pu(IV) («polymeric» form), amount of which in the hydroxide increases with keeping time at the cost of polymerization of hy drolyzed monomeric form of Pu(IV). Finally, regardless of the method of preparation, after 4 month keeping all the prepared samples of Pu(IV) hydroxide have practically identical composition containing highly polymerized ( 90%) and weakly polymerized ( 10%) Pu(IV) hydroxide.
The presence of polymeric Pu(IV) in the precipitate of Pu(OH)4 was spectrophotometrically demonstrated by transferring the polymeric hydroxide into the solution at pH=2. It was established by the method of centrifugal ultra-filtration that the main amount of polymeric Pu(IV) species (~ wt%) in the solution has molecular masses more than 100 kDa. Fraction of Pu(IV) with molecular masses from 100 to 10 kDa comprises ~4 wt%, and fraction with those less then 3 kDa amounts to ~0.2 wt% of the total Pu content in the solution.
It was shown by the methods of radiometry, spectrophotometry, sedimentation, centrifugation, and centrifugal ultra-filtration that over the precipitate of «mixed» and «polymeric» Pu(OH)4 in 0.01M NaCl solution at pH 4, 6, 8, and 10 practically all Pu(IV) (99.9 wt%) is present in the form of highly polymerized colloidal species. The plutonium concentration in these solutions varies from 10-4 to 10-7 M. Monomeric and weakly polymerized species of Pu(IV) are present in the solutions as well. Their concentration varies in the range from 0.1 to 0.001 wt% of the total Pu content depend ing on the solution pH as well as on the forms of Pu(IV) hydroxides, that are in contact with the so lution under study. These species may be in equilibrium with weakly polymerized form of hydrox ide, and in this case the content of those determines solubility of hydrolyzed monomeric or weakly polymerized forms of Pu(OH)4. On the other hand, these Pu(IV) species may be formed in the solu tion as a result of hydrolytic equilibrium between polymeric species and monomeric ions of Pu(IV), and in this case they do not determine solubility of Pu(OH)4.
The data obtained do not allow to explain uniquely a nature of monomeric and weakly polymer ized species of Pu(IV) that exist in 0.01M NaCl solution over the precipitates of Pu(OH)4 in «mixed» and «polymeric» forms. It is more important to keep in mind that Pu(IV) is present in these solutions as highly polymerized colloidal species with the result that Pu(IV) content in the so lution may vary in the wide range from 104 to 107 M. These Pu species are of greater importance in terms of radioechological and migratory behavior of this nuclide in the environment.
The work was supported by Russian Foundation for Basic Research, grants no. 06-03-32067a 2548 ХVIII Менделеевский съезд по общей и прикладной химии, Москва, LOW-TEMPERATURE PHOSPHATE MATRICES FOR IMMOBILIZATION OF LIQUID HIGH-LEVEL WASTES Vinokurov S.E., Orlov S.V., Kulyako Yu.M., Myasoedov B.F.
a Vernadsky Institute of Geochemistry and Analytical Chemistry of RAS b 119991 Moscow, Kosygin str., The matrices for the immobilization of high-level wastes (HLW) at present are obtained as a result of the prolonged high-temperature processing of a charge. We acquired the possibilities of the stabi lization of liquid HLW in the phosphate matrices, obtained under the conditions of low (room) and average (not higher than 1500C) temperatures by chemical reactions with the formation of ortho phosphates of potassium-magnesium and aluminum. The experiments were carried out on the so lidification of the HLW simulators, whose chemical and radiochemical composition matched the compositions of the real wastes: alkaline decantate and sludge from the HLW depositories. High chemical resistance of matrices with respect to the leaching of basic and contaminant (actinides, the fission and corrosion products) components was established. The leachability indexes of actinides Np237, Pu239, Am241 according to ANS 16.1 composed values of 13-14. The experimental techniques of stabilization of the liquid HLW imitators which contain the isotopes of cesium, strontium, tech netium, iodine and selenium were proposed. The physical characteristics of the obtained matrices were determined: density (1.6-1.8 g/cm3) and the mechanical stability (compressive strength not less than 25 MPa). The invariability of the properties of matrices and the absence of the hydrogen isolation with the lasting radiation exposure by internal (1wt.% Pu239) and external irradiation (Co60, the dose not less than 108 rad) were established. X-ray diffraction and scanning electron microscopy were used for investigating the phase composition of the matrices obtained. The distribution of ra dionuclides over the body of matrices was determined by autoradiography, the dependences of dis tribution on the incorporated radionuclides and the types of the solidified HLW simulators were es tablished.
The work was executed under financial support of Russian Science Support Foundation and grant of the President of Russian Federation on state support of the leading scientific schools (HШ-6602.2006.3) ХVIII Менделеевский съезд по общей и прикладной химии, Москва, 2007 ARTIFICIAL RADIONUCLIDES OF THE YENISEY RIVER FLOOD LAND SOILS Vlasova I.E.a, Konevnik Ju.V.a, Kalmykov S.N.a, Volosov A.G.b, Linnik V.G.b a Radiochemistry Div., Chemistry Dept., Lomonosov MSU, Moscow, Russia b Vernadsky Institute of Geochemistry and Analytical Chemistry RAS Both vertical and horizontal irregularity in distribution of artificial radionuclides have been revealed using landscape-radiometric investigations of the river Yenisey valley downstream Krasnoyarsk Mining and Chemical Combine (MCC), the source of contamination of Yenisey river flood lands by artificial radionuclides (1, 2). Vertical irregularity in artificial radionuclides concentration is due to the different periods of MCC functioning and hydrological regime which controlled transport and deposition of radionuclides within the flood lands of the Yenisey river (1, 2). It was established that the highest contribution to the specific activity of the Yenisey river flood lands is due to gamma emitting radionuclides. However, the hazard of long-lived alpha-emitting radionuclides for human beings causes the necessity of the assessment of artificial alpha-emitters spreading.
In the paper the results of investigation of two flood land cores from the most contaminated in Cs-137 districts from MCC influence zone (Berezovy Isl., Balchug Flood-land, 16-20 km from the discharge location) are presented. The activity measurement data of Cs-137, Co-60, Eu-152, 154, isotopes of Pu and U are offered in the paper. Alpha track analysis and fission track analysis of flood land soils revealed irregularity of microdistribution of alpha-emitting and fissile actinides in the soils of MCC influence zone.
References 1. Linnik V.G., Surkov V.V., Potapov V.N. et al. Geology and Geophysics, 2004 v.45, N10, pp.1220-1234.
2. Linnik V.G., Volosov A.G., Korobova E.M. et al. Radiochimija, 2004. V.46. N5, pp.471-476.
2550 ХVIII Менделеевский съезд по общей и прикладной химии, Москва, RAPID CHROMATOGRAPHIC RADIOCHEMICAL ANALYSIS Yepimahov V.N.a, Moskvin L.N.b a Alexandrov Research Institute of Technology, Sosnovy Bor, Leningrad region b St. Petersburg State University, St. Petersburg Radionuclide separation and preparation of emission sources for radioactivity measurement are combined to speed up the radiochemical analysis. In this case it is relatively easy to identify gamma-emitting radionuclides for which radiation self-absorption in the prepared source is not sig nificant. Block-shaped sorbents based on non-organic ion resin and extracting agents were devel oped for group and individual separation of uranium fission products which are reference radionu clides for evaluation of fuel cladding condition in the reactor core. With these sorbents only one sample is used to separate all monitored radionuclides such as iodine, cesium, strontium, rare-earth elements present in the primary coolant. For this purpose, the sample after preliminary adjustment of its chemical composition is filtered through a column with sorbents arranged in a certain order.
The sorbents are blown with air to remove sample remains and then sent for gamma-spectrometric measurement.
The next phase in the development of the rapid radiochemical analysis is selective separation of radionuclides on sorption membranes providing minimum self-absorption of beta- and alpha emission. Analysis time reduces by 10-50 times, detection limit decreases by 50-80 times, and accu racy and precision of obtained results are improved. Alpha- and beta-emission absorption coeffi cients of radionuclides separated on the membranes have insignificant and repeatable value (less than 5%) which allows both radiometric and spectrometric measurements of the prepared sources to be performed. Proposed methodology is universal. Methods of individual, group, and complex separation of radionuclides with following radioactivity measurement using standard radiometric and spectrometric equipment are developed based on block-shaped sorbents and sorption polytetra fluoroethylene, polyurethane foam, polyamide, and acetylcellulose membranes impregnated with different sorption agents. The developed methods have been metrologically certified and tested in process control and environment radiation monitoring applications. Combined methods including conventional routine procedures of sample preparation and procedures for separation of target ra dionuclides on volumetric collector sorbents and sorption membranes have been developed for samples which are the most difficult to analyze such as transuranic elements and 89,90Sr. In addition to high speed of the analysis, the advantage of the proposed approach is the possibility of using automatic equipment.
ХVIII Менделеевский съезд по общей и прикладной химии, Москва, 2007 REGULARITIES OF THE RADIONUCLIDE BEHAVIOR DURING THE LONG-TERM DEEP LIQUID RADIOACTIVE WASTE REPOSITORY OPERATION Zakharova E.V., Kaimin E.P., Menyailo K.A., Rodygina N.I., Volkova A.G.
IPCE RAS, 31 Leninsky Prospect, 119991 Moscow Intermediate- and low-level liquid radioactive waste in Russia is disposed of by injecting it into deep water-bearing permeable sandy-clayey reservoir beds isolated from higher and lower horizons by the confining beds. Over a period of more than 40 years the repository is formed, which is proved by the results of monitoring. The major quantity of the injected radionuclides is located in the vicinity of the injection wells (near field), where the interaction processes occur the most inten sively. In the far field of the repository the radionuclide content in the liquid phase is 3-6 orders of magnitude less and does not exceed several becquerel per liter.
The data on the far field repository condition were obtained from the analysis of underground water samples taken from the monitoring wells located in this zone. The processes occurred in the near field were evaluated merely by the experimental and mathematical modeling.
For the first time samples of the core material from the near field were taken in depth of the low level radioactive waste repository and from the confining strata. The core samples were taken from the monitoring wells located 12.5, 25.0, and 50.0 meters far from the injection well. The distribu tion has been investigated for 3H, 90Sr, 137Cs, 241Am, Pu and U radionuclides.
It was shown that the tritium content in the confining strata is 3-4 orders of magnitude less as compared to its concentration in the repository, and at the distance of 5 m from the repository bor der amounts 1 Bq/L, the total confining stratum thickness being 50 m. No marked penetration of other radionuclides into the confining beds has been observed.
It was found that the waste filtration in the repository occurs through the permeable sandy-clayey veins, and radionuclide concentrations in depth of the repository vary within the following ranges (given in terms of Bq per kilo of the rock): 520 – 6600 for 90Sr;
28 – 7300 for 137Cs;
5 – 25 for Am;
200 – 2700 for Pu;
and 80 – 220 for U at the distance of 12.5 m from the injection well. As the distance from the injection well increases, due to the sorption on the rocks the radionuclide con tent decreases by 1-2 orders of magnitude at the distance of 25 m and by 2-3 orders of magnitude at the distance of 50 m from the injection well.
The data presented allowed to obtain the actual radionuclide distribution in the vicinity of the in jection well and proved the confining strata anti-migration integrity after 40 years of the liquid low level radioactive waste repository operation.
This work was completed under the financial support of RFFR No. 05-03-32129.
2552 ХVIII Менделеевский съезд по общей и прикладной химии, Москва, INTERACTION OF THE MAIN ROCKFORMING MINERALS WITH THE ACIDIC SOLUTIONS CONTAINING RADIONUCLIDES Zakharova E.V.a, Volkova A.G.a, Menjaylo K.A.a, Vlasova I.E.b, Kalmykov S.N.b a Frumkin IPCE, Moscow, Russia b Radiochemistry Div., Chemistry Dept., Lomonosov MSU, Moscow, Russia Deep injection of radioactive wastes is inevitably accompanied by artificial impact on bearing strata. These rocks are complex polymineral systems on which sorption of radionuclides may pro ceed through different mechanisms that often cause difficulties for interpretation of the experimen tal data. Single rockforming minerals (quartz, muscovite, biotite, chlorite, feldspar) were investi gated before and after interaction with acidic 239Pu-, 241Am-containing solutions. The experiment lasted for about 8 years under following temperature conditions: 150°C the first 500 hours and 25°C then.
Formation of the new mineral phases on the surface of mineral grains was revealed using SEM EDX elemental mapping. New phases were formed from the chemical elements of acidic solutions and mineral leaching products. Partitioning of actinides on the surface of mineral grains was inves tigated using sequentional extraction technique. It was established that newly formed mineral phases hold considerable portion of Pu and only minor portion of Am.
According to the alpha track analysis (ATA) sorption of Pu and Am by the grains of different minerals vary in intensity and character of radionuclides microdistribution on the mineral surface.
Microdistribution of Pu and Am on the surface of micas and feldspar is defined by nonuniform character. The highest specific activity of sorbed actinides was attributed with the surface of chlo rite. Various character of radionuclide distribution in crooss-section of different mineral grains was confirmed using ATA data. In micas Pu and Am are observed to penetrate deep into mineral grains while in quartz there is no diffusion inside grains even after 8 years of experiment and radionuclides are concentrated on the grain surface.
Obtained results are evidence of artificial processes influence on sorption characteristics of min erals, partitioning of radionuclides and character of their distribution on mineral grains.
ХVIII Менделеевский съезд по общей и прикладной химии, Москва, 2007 PREPARATION, STABILIZATION AND SPECTRAL CHARACTERISTICS OF TECHNETIUM PEROXIDES Zhuikova D.N., German K.E., Peretrukhin V.F.
A.N. Frumkin Institute of Physical Chemistry and Electrochemistry RAS, Moscow, 31, Leninsky pr.
Complex peroxides of transition metals, the close Tc neighbors in Mendeleyev Periodic System, have been known for a long time1. Tc is considered to form no complex peroxides, the reaction be tween Tc (III, IV, and V) and hydrogen peroxide being practically instantaneous. This reaction is used for the conversion of the Tc least valency forms into Tc (VII).2 At the same time hydrogen peroxide is present in the radioactive wastes as a product of the H2O radiolysis. In this case an in tensive study of this reaction has got an important practical significance, because hydrogen perox ide must influence on stabilization of various unstable Tc redox forms and species.
The aim was to carry out the fundamental scientific investigation of earlier non-identified unsta ble Tc – form, with given spectral characteristics observed for some reprocessing solutions;
to find out the stabilization conditions of such forms (by the example of reaction between Tc(IV) and H2O2). The spectrophotometric analysis was used for a quantitative measuring-in of the Tc – oxida tive forms. The high-concentrated sulphuric acid was applied for organic phase modeling.
In this work we present the first observation that proved the existence of the intermediate Tc – forms in the system “Tc– H2O2” (Fig.1).
The study Tc (IV) time behaviour (the 1, mother solution) in anaerobic conditions in dicated the Tc (IV) persistence to oxidation.
1, The stabilization of unstable Tc peroxides was found out when sulphuric acid concen 0, tration was 12-18M H2SO4. The other re D quirement was hydrogen peroxide concen tration;
exactly the C (H2O2) increasing has 0, brought the time-life growth of unstable Tc peroxides. The careful analysis of experi- 0, 400 500 600 700 800 mental data has shown that Tc peroxides did wavelength, nm present in the system and they are two dif Fig.1. The generation and the decomposing of ferent Tc-ionic forms.
Peroxides of Tc-intermediate forms made a catalytic impact onto the reaction of the H2O2 decomposing. The observed two different Tc-ionic forms were characterized with the peaks at = 500 nm and 650 nm by model spectra deconvolution and the molar extinction coefficients for them and Tc (IV) were calculated: 400 = 2352±59 l/mol·cm;
650 = 5090±51 l/mol·cm;
500 = 2938±588 l/mol·cm. The examination of Tc (V and VI) peroxides formation and decomposing reac tions showed that they were ones of 1– st order by C(Tc)init and 0 – order by C(H2O2) and apparent reaction constants for them were calculated.
References 1. Par J.-M. Le Carpentier, R. Schlupp et R. Weiss, Acta Ctryst. (1972), B13, 1278.
2. V.I. Spitsyn V.I., A.F. Kuzina, Technetium – Moscow.: Nauka Publishers,1981. – p.29.
2554 ХVIII Менделеевский съезд по общей и прикладной химии, Москва, Tc AND Re CONCENTRATION FROM AQUEOUS MEDIA BY THE FIBROUS ION EXCHANGER FIBAN® Zhuikova D.N.a, Plevaka A.V.b, Troshkina I.D.b, German K.E.a, Peretrukhin V.F.a a A.N. Frumkin Institute of Physical Chemistry and Electrochemistry RAS, Moscow, 31, Leninsky pr.
b D.I. Mendeleev University of Chemical Technology of Russia, 9, Miusskaya sq.
At present time the main problems of the radioecology are the processing of radiochemical plant wastes and aqueous media purification from long-lived radionuclides, exactly Tc-99. Such interest is explained by Tc high mobility, migration activity, radiotoxity, high volume of semi-life time (T0, = 2,12·105 year) and Tc-99- existence in an aqueous media as TcO4–. The aim was to study the fibrous ion exchanger FIBAN® sorption properties of different kinds and to investigate possibility of its application for Tc-99 sorption from aqueous media (acidic and alkali model solutions and saline were explored). FIBAN® was produced at IFOCH NAS of Bela rus.
At the preliminary research the sorption of Re by FIBAN® was studied. Re is Tc- similarity and exists in an aqueous media as ReO4–. FIBAN® is based on acrylic fibers, containing following an ion-exchange groups:
-N (CH2COO-)2 (FIBAN C – 1, FIBAN A – 6), =NH, -NH2, -COOH, N (FIBAN AK – 22). The main advantage of a fibrous ion exchanger over a granular ion exchanger is a high sorption rate2. The sorption from an aqueous media (pH=2) was carried out in static condi tions. The ammoniac solution was used for Re elution. High value of percentage distribution (Kd) was shown to be for fibrous ion exchangers: A – 6 and AK – 22. The sorption extent was 71 and 97% accordingly and as result they were chosen for Tc-99-sorption study.
The extraction degree of TcO4– from solutions was appreciated at its – activity before and after sorption using the liquid scintillation counter: Beckman LS – 6500. The dependence Kd on pH was found out to have an extreme nature: A-6 (pH 7) and AK-22 (pH 4) have maximum Kd, exactly 5300 and 5100 accordingly. The kinetic mechanism was studied by the limited volume method. The experimental data analysis have shown that the sorption by AK-22 and A-6 from acidic and alkali model solutions had been practically completed for the first 15 min (S 90%, S – the sorption completeness). The sorption kinetic mechanism was defined;
it’s the membranous kinetic mecha nism (the dependence (-lg (1-F) on t) had linear character). The analysis of experimental data of the Tc – sorption from saline (Na2CO3, Ca(NO3)2, Na2SO4, KCl) by Fiban A – 6 has shown that S (Tc 99) was 60-80%.
References 1. Milton G.M., Cornett R.J., Kramer S.J., Vezinu A., Radiochim. Acta, 1992, Vol.58 / 59, P. 291 – 296.
2. Shimidzu Chiroshi, J. Ion Exchange, 4 (1993) 96.
Секция Международный симпозиум «Зеленая химия, устойчивое развитие и социальная ответственность химиков»
Руководители – академик В.В.Лунин и чл.-корр. РАН Н.П.Тарасова Устные доклады ХVIII Менделеевский съезд по общей и прикладной химии, Москва, 2007 GRAND CHALLENGES FOR CHEMISTRY:
ENERGY AND WATER Hardy J.J.E.
Royal Society of Chemistry, Burlington House, Piccadilly, London, W1J 0BA, UK In order to maintain a environmentally, econnmomically and socially sustainable existance on Earth humankind must overcome several grand challenges in the coming years. In addition to understan ding, mitigating and adpating to climate change the provision of sustanainable energy1 and water are perhaps the biggest of the challenges facing us. The chemical sciences will play a hugely impor tant role in developing technologies that will move us towards a sustainable existence. In this pre sentation the provision of energy and water will be examined through chemistry goggles and the role of chemistry will be assessed. Looking forwards the presentation will examine a series of case studies on the development pathways for key technologies (including photovoltaics, carbon capture and storage, water monitoring, water treatment and water efficiency) and highlight how chemistry will deliver sustainable solutions. The presentation will also focus on the need for skilled people and strategic funding.
References 1. Royal Society of Chemistry report – Chemical Science Priorities for Sustainable Energy (www.rsc.org) 2. Royal Society of Chemistry report (to be published 2007) – Chemical Science Priorities for Sustainable Water (www.rsc.org) 2558 ХVIII Менделеевский съезд по общей и прикладной химии, Москва, FOR GOOD OR ILL: ETHICAL ISSUES FOR CHEMISTS Hay A.
Professor of Environmental Toxicology, Molecular Epidemiology Unit, LIGHT Laboratories, Clarendon Way, University of Leeds, Leeds, LS2 9JT, UK Chemistry has a vital role in a modern industrial society. Indeed, it has played a crucial role throughout recorded history without citizens being aware that it was chemistry. The processes in volved in food preparation, fermentation of sugars, dyeing of textiles or manuscripts, fabrication of buildings all relied on different chemical reactions. They still do. Today, however, chemistry per meates well beyond these confines and it will provide answers and tools for dealing with even more complex issues ranging from the processes in the earth’s atmosphere, provision of clean water, new medicines and even gene modification of plants and animals for different foodstuffs or improved human health. This is a message that chemists need to tell the world. The training they have equips them to do enormous good. But there is a reverse side to this coin. Some 90 years ago chemistry provided the means to kill and injure people on a vast scale. Both the toxic and physical properties of chemicals were exploited for use in warfare. In World War 1 there some 1.5 million chemical warfare casualties on the Western and Russian fronts. Estimates of recorded deaths range from 50,000 to 100,000. These figures account for those who died soon after their exposure to chlorine, phosgene or mustard gas. But many others had more chronic health problems particularly of the lung such that there breathing was affected. Many of these ex-soldiers will have died prematurely when their lungs were no longer able to capture sufficient oxygen to sustain life. We now have even more efficient chemical weapons that kill after exposure to smaller quantities. But it is not all bad news. Governments have recognised the need to rid the world of chemical weapons and there is an international treaty (the Chemical Weapons Convention) that requires this and which at least countries have signed. The Organisation for the Prohibition of Chemical Weapons (OPCW) based in The Hague, enforces the treaty. Under its terms countries are required to destroy any chemical weapons they have. Crucially, they also agree not to produce any new weapons. Chemists would be needed if a country decided to rearm with chemical munitions. It is for this reason that the OPCW and the International Union of Pure and Applied Chemistry (IUPAC) have embarked on an educa tional programme for chemists, a programme to both inspire chemists about the positive contribu tions they make to society but also to warn them about how their trade can be misused. This talk will describe the joint IUPAC/OPCW educational programme.
ХVIII Менделеевский съезд по общей и прикладной химии, Москва, 2007 WEIGHING RISKS AND PROMOTING SCIENTIFICALLY SOUND CHOICES Hogue L., Sarquis A.M.
Miami University, 4200 East University Blvd., Middletown OH, 45042, U.S.A HogueLM@muohio.edu;
It is a well-known fact that scientists and other risk professionals frequently have differing views of risks than those held by the general public. This divide is created and fueled in part by the general public’s lack of scientific literacy and the highly emotional handling of such issues by the media.
Our role as professionals in the chemical sciences compels us to work to dispel the fear and lack of understanding that shroud our profession. This presentation will describe the highly successful Risks & Choices program—a collaborative effort between Miami University’s Center for Chemis try Education, scientists, and teachers from throughout the United States to prepare students to make informed personal and social choices regarding the effects on human health of exposure to physical and chemical agents. Sample activities that emphasize human and ecological risk assess ment and show the relationship between environmental toxins and human health will be shared.
2560 ХVIII Менделеевский съезд по общей и прикладной химии, Москва, GREEN CHEMISTRY USING GOLD CATALYSIS Hutchings G.
School of Chemistry, Cardiff University, Cardiff UK CF10 3AT Hutch@cardiff.ac.uk Green chemistry has at its heart catalysis as one of the key underpinning technologies. Of the cat lytic approaches available to industry heterogeneous catalysis is considered preferable in many cases. Heterogeneous catalysis plays a major role in the general life of the general public, not only with respect to an economic viewpoint, but it also provides the necessary infrastructure for the well being of society as a whole. Without effective heterogeneous catalysis the manufacture of many materials, pharmaceuticals and foodstuffs would not be possible. Selective oxidation remains one of the key synthetic steps for the activation of a broad range of substrates for the production of either finished products of intermediates for the preparation of pharmaceuticals, agrochemicals, as well as commodity chemicals. Given its central importance, it is surprising that there have been few new approaches in the design of selective oxidation catalysts in the past forty years, and thereby stimu late new green chemistry approaches to oxidation chemistry.
A key discovery in recent years has been the identification that gold, when prepared as supported nanoparticles, is exceptionally effective as an oxidation catalyst. To some extent this observation is counter intuitive since extended gold surfaces do not chemisorb oxygen, nor do they corrode. Gold is known as an immutable material, much prized for its beauty and value, which, for many years, has diverted attention from its intrinsic high reactivity. Following this discovery, there has been an explosion of interest in gold as a catalyst and several hundred papers and tens of patents are being published annually, although much of this concerns the relatively simple oxidation of CO. Gold ca talysis is now a major topic for both heterogeneous and homogeneous catalysis worldwide. This presentation will explore the latest developments using supported gold and gold palladium nanopar ticles the formation of hydrogen peroxide and the selective oxidation of alcohols. This will include recent studies on the direct synthesis of hydrogen peroxide, the epoxidation of alkenes and the se lective oxidation of alcohols.
References 1. Mathew D. Hughes, Yi-Jun Xu, Patrick Jenkins, Paul McMorn, Philip Landon, Dan I. Enache, Albert F. Carley, Gary A. Attard, Graham J. Hutchings, Frank King, E. Hugh Stitt, Peter Johnston, Ken Griffin and Christopher J.
Kiely, Tunable gold catalysts for selective hydrocarbon oxidation under mild conditions, Nature 437 (2005) 1132, doi:10.1038/nature 2. Enache, Dan I.;
Edwards, Jennifer K.;
Carley, Albert F.;
Herzing, An drew A.;
Kiely, Christopher J.;
Knight, David W.;
Hutchings, Graham J., Solvent-Free Oxida tion of Primary Alcohols to Aldehydes Using Au-Pd/TiO2 Catalysts, Science 311 (2006) 362, doi:10.1126/science. ХVIII Менделеевский съезд по общей и прикладной химии, Москва, 2007 SUSTAINABILITY: THE FUTURE CHALLENGES FOR STUDENTS OF THE PRESENT Lerman Z.M.
Columbia College Chicago, 600 South Michigan Avenue, Chicago, IL 60605 USA ZAFRAL@aol.com The Middle East is a region in permanent conflict. Part of the reason for this situation is that this part of the world has a source of energy that, for the industrialized world, is a strategic resource:
fossil fuel. This non-renewable source of energy is not only fueling economic and political con flicts, but it is also placing at risk the sustainability of the planet, by polluting the environment and contributing to climate changes.
There are now six billion people on Planet Earth, and they are consuming six billion tons of fos sil fuels each year;
most of this is being consumed by developed countries. With the expectation of ten billion people by the year 2050 and with the increasing consumption of fossil fuels by develop ing countries, we will run out of these energy resources, cause irreversible environmental damage, adversely affect the food supply that depends on energy, and endanger the sustainability of life on Planet Earth.
We must develop new and clean energy resources. It is a fact that the amount of solar energy re ceived by the surface of the Earth in one hour is approximately equal to the total energy consump tion of the entire planet in one year at present.
The scientific community must promote the use of renewable sources of energy. In this way the existing energy resources in the Middle East will not continue to be a strategic resource. This will decrease their contribution to detrimental climate change, and their value in the economic and po litical conflicts between countries.
It is the responsibility of the scientific community to (1) promote the development and use of clean energy resources, (2) add the subject of sustainability in the curriculum to prepare future sci entists with the background needed to preserve life on Planet Earth, and (3) guarantee cross-border scientific collaboration and cooperation, even between countries whose governments are hostile to ward each other.
Examples will be presented in the lecture of cross-border scientific collaborations in the Middle East, as well as examples of curricular material that promote clean renewable energy sources.
2562 ХVIII Менделеевский съезд по общей и прикладной химии, Москва, THE ROLE FOR CHEMISTRY EDUCATION IN SEEING AND UNDERSTANDING CLIMATE CHANGE Mahaffy P.
Chemistry Department, The King’s University College and CRYSTAL Alberta Centre for Research in Youth Science Teaching and Learning, 9125 50th St., Edmonton, AB, Canada, T6B 2H3. email@example.com The world’s attention has been drawn to the fundamental relationship between human activity and chemical reactivity by the recently issued Intergovernmental Panel on Climate Change 4th Assess ment Report. Substances we introduce into the atmosphere interact with each other and with elec tromagnetic radiation, causing fundamental changes in the atmospheric envelope that supports life and human activity. Those changes pose major new challenges to our ability to meet Millennium Development Goals.
How can chemistry education help equip the next generation to understand and address this and other challenging issues facing our planet, so they can make informed decisions about energy use and lifestyles based on scientific evidence? Much of the science underlying climate change builds on basic understanding of the interaction of molecules with electromagnetic radiation, on the time scale for atmospheric processes, and on the nature of modeling.
We will focus on common student misconceptions about the chemistry underlying climate change and introduce several computer-based learning objects created at the King’s Centre for Visualization designed to help students see and understand.
Fig. 1. Computer-based learning objects to facilitate understanding of science underlying climate change ХVIII Менделеевский съезд по общей и прикладной химии, Москва, 2007 CHARACTERISING POLLUTION FROM MINING USING DISCRETE PHYSICO-CHEMICAL PROCESSES Noller B.N.
The University of Queensland, Brisbane, QLD Australia Correspondence: firstname.lastname@example.org Water pollution from mining is characterised by basic properties such as acidity/alkalinity and dis solved salts or electrical conductivity. The elemental composition of wastewater itself enables an estimate of likely environmental effect when criteria exist but discrete knowledge of the chemical forms present and ultimately their bioavailabilities is needed to predict effects on environmental systems, eg aquatic ecosystems. Discrete chemical species, including those associated with back ground properties of mineralisation, may assist with understanding the process of dispersion of con taminants in situations where there may be more than one polluting process.
Environmental markers are defined as molecular species which are indicative of the origin of the associated contaminants during dispersion from their source into the environment. They are usually conservative chemical species. Two kinds of anionic species are involved with discrete transport processes that prolong removal from the water column via dilution: (i) Oxyanions of transition met als and metalloids (eg molybdate, vanadate, dichromate, tungstate and stibnite);
and (ii) Complexes which have very high stability (eg carbonate, EDTA or cyanide complexes of metals).
Examples of environmental markers of water pollution are as follows:
• Rhenium in waste water at the Ranger Uranium Mine, Northern Australia showing mobility following land application • Antimony as a limiting constituent in excess wastewater accumulated in the tailings dam at the Gympie Eldorado Gold Mine Queensland • Cobalt as an impurity in cyanide following cleanup at the Tolukuma gold mine, Papua New Guinea • Complexation of metals with cyanide and chloride following an uncommon rainfall event at an arid zone location near Tennant Creek, Northern Territory • Complexing of aluminium and minimisation of water toxicity to fish in waters flowing to the Magela Creek floodplain, Northern Australia An understanding of such chemical processes provides a means to control the pollution that might cause. Sulfate is a dominant anionic form (anion) at many mine sites. Chloride may also be dominant. Discrete processes may occur with trace elements being dependent on their presence and physico-chemical conditions. When the chemical species are conservative they may be used as dis crete environmental markers (simple or complex ions) and used to trace pollution sources.
2564 ХVIII Менделеевский съезд по общей и прикладной химии, Москва, HEALTHRICH: HEALTH RISKS, INFORMATION, AND CHOICES Sarquis A.M., Hogue L.
Miami University, 4200 East University Blvd., Middletown OH, 45042, U.S.A email@example.com;
HogueLM@muohio.edu This presentation will describe HealthRICH—an exciting, informal education program that chal lenges young teens and their families to make informed lifestyle choices to reduce environmental health risks. A series of print and web resources has been developed for use by scientists in out reach efforts as well as for museums, science centers, club sponsors, and community leaders to use directly with young teens and their families. Designed to appeal to young teens with detective-type scenarios, magazine-style readings, and popular imagery, the HealthRICH materials are unique and valuable resources that offer an interdisciplinary and multi-modal approach to important health and environment topics in the context of personal and social perspectives. This program was developed with funding from the U.S. National Center for Research Resources of the National Institutes of Health.
ХVIII Менделеевский съезд по общей и прикладной химии, Москва, 2007 OPPENHEIMER’S SHADOW: HIS NUCLEAR WORLD AND OURS Sherwin M.J.
The physicist J. Robert Oppenheimer emerged from the shadow of the Manhattan Project in 1945, at age 41, as America’s Prometheus, the nation’s most prominent scientist. He was the “Father of the Atomic Bomb,” the boy genius who led distinguished scientists in the effort to build an atomic bomb in time to be used during World War II. It was the crowning achievement of his career, and a terrible burden for his soul. Oppenheimer came to see that he had delivered into the hands of the military establishment a weapon that they were inclined to use carelessly. This paper reports on Oppenheimer’s efforts to initiate the international control of atomic energy, his opposition to the hydrogen bomb, his criticism of secrecy, and his persecution by the Eisenhower administration whose nuclear policies he opposed. The parallels with Andre Sakharov are many and will be dis cussed.
Martin J. Sherwin is Honorable UNESCO Professor of Mendeleev University and University Professor at George Mason University in Fairfax, Virginia. His most recent book, American Prome theus: The Triumph and Tragedy of J. Robert Oppenheimer was awarded the 2006 Pulitizer Prize for Biography, The National Book Critics Circle Award, and the English Speaking Union’s Book Prize. It is scheduled to be published in a Russian edition in 2007 or 2008.
2566 ХVIII Менделеевский съезд по общей и прикладной химии, Москва, CLEAN REAGENTS, GREEN CATALYSIS AND NEW REACTION CONDITIONS Tundo P.
Interuniversity Consortium "Chemistry for the Environment";
Via della Industrie 21/8 30175 Marghera Venice (Italy) In the last two decades dimethylcarbonate (DMC) has proved to be an environmentally benign sub stitute for dimethyl sulphate and methyl halides as a methylating agent.1 In fact it has been exten sively demonstrated that the reaction of nucleophiles such as anilines2, phenols3 and methylene active prducts4 with dimethylcarbonate (DMC) at T 150°C give the methylated compounds via a BAl2 mechanism5 in almost quantitative yield. Most importantly CO2 and methanol are the only by products formed during the methylation which is, for this reason, a green process. However, when the reaction is performed in similar conditions using alcohols as substrates, the main product formed is the methylcarbonate, which immediately undergoes decarboxylation to the corresponding methylether with high selectivity. Base ROCH3 + CH3OH + CO ROCOOCH ROH + CH3OCOOCH Fig. 1. Synthesis of methylethers by the reaction of alcohols with DMC References 1. (a) P. Tundo, Continuous Flow Methods in Organic Synthesis, 1991, Horwood, E. Pub., Chichester (UK);
Ono, 1997, Appl. Catal. A, 155, 133. P. Tundo and M. Selva, Acc. Chem. Res., 2002, 35, 706.
2. M. Selva, A. Bomben and P. Tundo, J. Chem. Soc., Perkin Trans. I, 1997, 1041.
3. A. Bomben, M. Selva and P. Tundo, 1999. Ind. Eng. Chem. Res. 38, 2075.
4. a) P. Tundo,G. Moraglio and F. Trotta, Ind. Eng. Chem. Res. 1989, 28, 881;
b) P. Tundo, M. Selva and C. A.
Marques, Green Chemistry: Designing Chemistry for the Environment, ed. P.T. Anastas, T.C. Williamson, ACS Symp. Ser. 626, 1997 p.81;
5. a) P. Tundo, M. Selva, A. Perosa and S. Memoli, 2002, J. Org. Chem. 67, 1071;
b) S. Memoli, M. Selva and P.
Tundo Chemosphere, 2001, 43, 115.
6. P. Tundo, S. Memoli, D. Hrault and K. Hill, 2004, Green Chem., 6, 609–612.
ХVIII Менделеевский съезд по общей и прикладной химии, Москва, 2007 INTRODUCING GREEN CHEMISTRY CONCEPTS INTO THE CURRICULUM Ware S.
3714 Camden Street, SE, Washington, DC firstname.lastname@example.org This presentation will describe materials available in the United States for introducing green chem istry concepts into secondary and university courses. Materials to be discussed were produced at various institutions including the American Chemical Society Education Division, the Green Chem istry Institute, the University of Oregon, and the University of Scranton. These materials may be infused into existing courses, or serve as stand-alone materials.
2568 ХVIII Менделеевский съезд по общей и прикладной химии, Москва, ХИМИКО-ТЕХНОЛОГИЧЕСКИЕ АСПЕКТЫ ПРОИЗВОДСТВА ГУМИНОВЫХ ПРЕПАРАТОВ НОВОГО ПОКОЛЕНИЯ Богословский В.Н., Левинский Б.В.
ЗАО ТПК «Техноэкспорт», 141300,Московская область,г.Сергиев Посад,ул.Академика Силина, Гуминовые кислоты – это уникальные природные соединения, играющие фундаментальную роль в экосистеме «вода – растение – почва», а их водорастворимые соли гуматы и хелаты – действующая основа эффективных природных стимуляторов роста растений, животных и птиц1. За полувековую историю использования гуматов накоплен громадный опыт их поло жительного воздействия на любые сельскохозяйственные культуры, животных и человека.
Тем не менее, эти данные далеко не однозначны и между ними есть существенные различия.
В результате системного анализа большого числа публикаций мы пришли к выводу, что для обеспечения сопоставимости результатов необходим некий стандарт гуминового препарата.
Другой не менее важной проблемой является товарная форма гуминового препарата, которая должна быть удобной для конечного потребителя. Поэтому необходим определенный ассор тимент товарных форм: гранулы для кондиционирования почв, растворы для распыления, тонкие порошки для скармливания животным и птицам. И, наконец, гуминовые препараты должны поставляться сельскому потребителю по доступным ценам, а их себестоимость должна обеспечивать достойную норму прибыли для производителя.
Для решения поставленных задач потребовалась оптимизация сырьевой базы и поиск но вых технических решений для технологического прорыва в этой области.