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Sample records for metal compounds immobilized

  1. Potential value of phosphate compounds in enhancing immobilization and reducing bioavailability of mixed heavy metal contaminants in shooting range soil.

    Science.gov (United States)

    Seshadri, B; Bolan, N S; Choppala, G; Kunhikrishnan, A; Sanderson, P; Wang, H; Currie, L D; Tsang, Daniel C W; Ok, Y S; Kim, G

    2017-10-01

    Shooting range soils contain mixed heavy metal contaminants including lead (Pb), cadmium (Cd), and zinc (Zn). Phosphate (P) compounds have been used to immobilize these metals, particularly Pb, thereby reducing their bioavailability. However, research on immobilization of Pb's co-contaminants showed the relative importance of soluble and insoluble P compounds, which is critical in evaluating the overall success of in situ stabilization practice in the sustainable remediation of mixed heavy metal contaminated soils. Soluble synthetic P fertilizer (diammonium phosphate; DAP) and reactive (Sechura; SPR) and unreactive (Christmas Island; CPR) natural phosphate rocks (PR) were tested for Cd, Pb and Zn immobilization and later their mobility and bioavailability in a shooting range soil. The addition of P compounds resulted in the immobilization of Cd, Pb and Zn by 1.56-76.2%, 3.21-83.56%, and 2.31-74.6%, respectively. The reactive SPR significantly reduced Cd, Pb and Zn leaching while soluble DAP increased their leachate concentrations. The SPR reduced the bioaccumulation of Cd, Pb and Zn in earthworms by 7.13-23.4% and 14.3-54.6% in comparison with earthworms in the DAP and control treatment, respectively. Bioaccessible Cd, Pb and Zn concentrations as determined using a simplified bioaccessibility extraction test showed higher long-term stability of P-immobilized Pb and Zn than Cd. The differential effect of P-induced immobilization between P compounds and metals is due to the variation in the solubility characteristics of P compounds and nature of metal phosphate compounds formed. Therefore, Pb and Zn immobilization by P compounds is an effective long-term remediation strategy for mixed heavy metal contaminated soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Tritium immobilization and packaging using metal hydrides

    International Nuclear Information System (INIS)

    Holtslander, W.J.; Yaraskavitch, J.M.

    1981-04-01

    Tritium recovered from CANDU heavy water reactors will have to be packaged and stored in a safe manner. Tritium will be recovered in the elemental form, T 2 . Metal tritides are effective compounds in which to immobilize the tritium as a stable non-reactive solid with a high tritium capacity. The technology necessary to prepare hydrides of suitable metals, such as titanium and zirconium, have been developed and the properties of the prepared materials evaluated. Conceptual designs of packages for containing metal tritides suitable for transportation and long-term storage have been made and initial testing started. (author)

  3. Compound immobilization and drug-affinity chromatography.

    Science.gov (United States)

    Rix, Uwe; Gridling, Manuela; Superti-Furga, Giulio

    2012-01-01

    Bioactive small molecules act through modulating a yet unpredictable number of targets. It is therefore of critical importance to define the cellular target proteins of a compound as an entry point to understanding its mechanism of action. Often, this can be achieved in a direct fashion by chemical proteomics. As with any affinity chromatography, immobilization of the bait to a solid support is one of the earliest and most crucial steps in the process. Interfering with structural features that are important for identification of a target protein will be detrimental to binding affinity. Also, many molecules are sensitive to heat or to certain chemicals, such as acid or base, and might be destroyed during the process of immobilization, which therefore needs to be not only efficient, but also mild. The subsequent affinity chromatography step needs to preserve molecular and conformational integrity of both bait compound and proteins in order to result in the desired specific enrichment while ensuring a high level of compatibility with downstream analysis by mass spectrometry. Thus, the right choice of detergent, buffer, and protease inhibitors is also essential. This chapter describes a widely applicable procedure for the immobilization of small molecule drugs and for drug-affinity chromatography with subsequent protein identification by mass spectrometry.

  4. Metal immobilization in soils using synthetic zeolites

    NARCIS (Netherlands)

    Osté, L.A.; Lexmond, T.M.; Riemsdijk, van W.H.

    2002-01-01

    In situ immobilization of heavy metals in contaminated soils is a technique to improve soil quality. Synthetic zeolites are potentially useful additives to bind heavy metals. This study selected the most effective zeolite in cadmium and zinc binding out of six synthetic zeolites (mordenite-type,

  5. Preparation of polymeric fibers immobilizing inorganic compounds, enzymes, and extractants designed for radionuclide decontamination, ultrapure water production, and rare-earth metal purification

    International Nuclear Information System (INIS)

    Saito, Kyoichi

    2014-01-01

    To remove and recover targeted ions and molecules at a high rate, inorganic compounds, enzymes, and extractants were immobilized onto a commercially available 6-nylon fiber by radiation-induced graft polymerization and subsequent chemical modifications. Fibrous supports with a smaller diameter provide a larger external interface area with liquids. Modified fibers are fabricated into various shapes such as wound filter and braid according to application sites. First, insoluble cobalt ferrocyanide-impregnated fiber was prepared via precipitation by immersing ferrocyanide ion-bound anion-exchange fiber in cobalt chloride solution. Cobalt ferrocyanide impregnated onto the polymer chain grafted onto the fiber specifically captured cesium ions in seawater. Similarly, sodium titanate impregnated onto a cation-exchange fiber selectively captured strontium ions in seawater. Second, urease was bound by an anion-exchange graft chain, followed by enzymatic cross-linking among urease molecules with transglutaminase. The bed charged with the urease-immobilized fiber exhibited a quantitative hydrolysis of urea at a high space velocity of urea solution. Third, an acidic extractant (HDEHP, bis(2-ethylhexyl) phosphate) was impregnated onto a dodecylamino-group-containing polymer chain grafted onto the 6-nylon fiber. Distribution coefficients of the HDEHP-impregnated fiber for neodymium and dysprosium agreed well with those in n-dodecane. (author)

  6. Phosphopeptide enrichment by immobilized metal affinity chromatography

    DEFF Research Database (Denmark)

    Thingholm, Tine E.; Larsen, Martin R.

    2016-01-01

    Immobilized metal affinity chromatography (IMAC) has been the method of choice for phosphopeptide enrichment prior to mass spectrometric analysis for many years and it is still used extensively in many laboratories. Using the affinity of negatively charged phosphate groups towards positively...... charged metal ions such as Fe3+, Ga3+, Al3+, Zr4+, and Ti4+ has made it possible to enrich phosphorylated peptides from peptide samples. However, the selectivity of most of the metal ions is limited, when working with highly complex samples, e.g., whole-cell extracts, resulting in contamination from...

  7. Immobilization of N-Heterocyclic Carbene Compounds: A Synthetic Perspective.

    Science.gov (United States)

    Zhong, Rui; Lindhorst, Anja C; Groche, Florian J; Kühn, Fritz E

    2017-02-08

    Over the course of the past 15 years the success story of N-heterocyclic carbene (NHC) compounds in organic, inorganic, and organometallic chemistry has been extended to another dimension. The immobilization of NHC compounds, undergoing continuous diversification, broadens their range of applications and leads to new solutions for challenges in catalytic and synthetic chemistry. This review intends to present a synthetic toolkit for the immobilization of NHC compounds, giving the reader an overview on synthetic techniques and strategies available in the literature. By individually summarizing and assessing the synthetic steps of the immobilization process, a comprehensive picture of the strategies and methodologies for the immobilization of NHC compounds is presented. Furthermore, the characterization of supported NHC compounds is discussed in detail in order to set up necessary criteria for an in-depth analysis of the immobilized derivatives. Finally, the catalytic applications of immobilized NHC compounds are briefly reviewed to illustrate the practical use of this technique for a broad variety of reaction types.

  8. Comparative assessment of heavy metal removal by immobilized ...

    African Journals Online (AJOL)

    EJIRO

    Key words: Biosorption, bacteria, heavy metal, dead bacterial cells, immobilization. INTRODUCTION ... Moreover, the metals cannot be degraded to harmless products and ... a sterile plastic container and taken immediately to the laboratory.

  9. Electrode-immobilized compounds through γ radiation

    International Nuclear Information System (INIS)

    De Castro, E.S.

    1983-01-01

    Chemically Modified Electrodes (CMEs) are used as substrates in heterogeneous catalysis and as sensors. This work demonstrates a new strategy for immobilizing polyelectrolytes and electroactive agents on electrode surfaces. The success of this method lies in cross-linking water soluble polymer chains through the ionizing radiation of γ emissions from a 60 Co source. Cross-linking can create a continuous network out of the polymer macromolecules which then makes the network insoluble on the electrode surface. Bonds between the network and the substrate are also possible. Redox species mixed with the polymer network and irradiated become part of the insoluble network, and are permanently attached. The use of γ radiation to make electrochemical sensors is demonstrated. The immobilized network poly[diallyl dimethyl ammonium chloride] (DDAC) is placed in a solution of potassium ferricyanide and ionicly exchanges the anion into the network. An electroactive network is created from irradiating a mixture of DDAC and 2,6-dichlorophenolindophenol (DCIP). Using the amount of electroactive DCIP remaining in the film as the optimization parameter, variables such as polymer:DCIP ratio, film thickness, and dosage employed are shown to be relevant

  10. Immobilization of krypton in a metal matrix

    International Nuclear Information System (INIS)

    Whitmell, D.S.

    1987-01-01

    The report presents the work carried out on the immobilization of krypton in a metallic matrix by combined ion implantation and sputtering. The process has been successfully tested using 100 curies of fully active krypton in order to demonstrate that the process operates in the radiation levels which will be obtained with active gas at a reprocessing plant. A design study for a plant for fuel reprocessing has shown that the process can be simply operated, without requiring shielded cells. These results, which complete the development programme, indicate that the process is ideal for the containment of kripton arising from the processing of nuclear fuel and that the product will retain the gas under normal storage conditions and also during simulated accident conditions

  11. Conversion of radioactive ferrocyanide compounds to immobile glasses

    International Nuclear Information System (INIS)

    Schulz, W.W.; Dressen, A.L.

    1977-01-01

    Complex radioactive ferrocyanide compounds result from the scavenging of cesium from waste products produced in the chemical reprocessing of nuclear fuel. These ferrocyanides, in accordance with this process, are converted to an immobile glass, resistant to leaching by water, by fusion together with sodium carbonate and a mixture of (a) basalt and boron trioxide (B 2 O 3 ) or (b) silica (SiO 2 ) and lime (CaO). 7 claims

  12. Remediation of soils contaminated with heavy metals with an emphasis on immobilization technology.

    Science.gov (United States)

    Derakhshan Nejad, Zahra; Jung, Myung Chae; Kim, Ki-Hyun

    2018-06-01

    The major frequent contaminants in soil are heavy metals which may be responsible for detrimental health effects. The remediation of heavy metals in contaminated soils is considered as one of the most complicated tasks. Among different technologies, in situ immobilization of metals has received a great deal of attention and turned out to be a promising solution for soil remediation. In this review, remediation methods for removal of heavy metals in soil are explored with an emphasis on the in situ immobilization technique of metal(loid)s. Besides, the immobilization technique in contaminated soils is evaluated through the manipulation of the bioavailability of heavy metals using a range of soil amendment conditions. This technique is expected to efficiently alleviate the risk of groundwater contamination, plant uptake, and exposure to other living organisms. The efficacy of several amendments (e.g., red mud, biochar, phosphate rock) has been examined to emphasize the need for the simultaneous measurement of leaching and the phytoavailability of heavy metals. In addition, some amendments that are used in this technique are inexpensive and readily available in large quantities because they have been derived from bio-products or industrial by-products (e.g., biochar, red mud, and steel slag). Among different amendments, iron-rich compounds and biochars show high efficiency to remediate multi-metal contaminated soils. Thereupon, immobilization technique can be considered a preferable option as it is inexpensive and easily applicable to large quantities of contaminants derived from various sources.

  13. Adsorption of metals by immobilized tannins

    Energy Technology Data Exchange (ETDEWEB)

    Santana, J L; Olivares, S; De La Rosa, D; Martinez, F; Vargas, L M [Centro de Estudios Aplicados al Desarrollo Nuclear (CEADEN), La Habana (Cuba)

    1996-05-01

    Simultaneous adsorption of thorium, europium, cerium, and neodymium by immobilized tannic was studied at different ph values. Tannic materials have excellent ability to adsorb selectively thorium at pH 5. The rest of the elements could be isolated in group at pH 7.

  14. Adsorption of metals by immobilized tannins

    International Nuclear Information System (INIS)

    Santana, J.L.; Olivares, S.; De La Rosa, D.; Martinez, F.; Vargas, L.M.

    1996-01-01

    Simultaneous adsorption of thorium, europium, cerium, and neodymium by immobilized tannic was studied at different ph values. Tannic materials have excellent ability to adsorb selectively thorium at pH 5. The rest of the elements could be isolated in group at pH 7

  15. Laccase Immobilization by Chelated Metal Ion Coordination Chemistry

    Directory of Open Access Journals (Sweden)

    Qingqing Wang

    2014-09-01

    Full Text Available In this work, amidoxime polyacrylonitrile (AOPAN nanofibrous membrane was prepared by a reaction between PAN nanofibers and hydroxylamine hydrochloride. The AOPAN nanofibrous membranes were used for four metal ions (Fe3+, Cu2+, Ni2+, Cd2+ chelation under different conditions. Further, the competition of different metal ions coordinating with AOPAN nanofibrous membrane was also studied. The AOPAN chelated with individual metal ion (Fe3+, Cu2+, Ni2+, Cd2+ and also the four mixed metal ions were further used for laccase (Lac immobilization. Compared with free laccase, the immobilized laccase showed better resistance to pH and temperature changes as well as improved storage stability. Among the four individual metal ion chelated membranes, the stability of the immobilized enzymes generally followed the order as Fe–AOPAN–Lac > Cu–AOPAN–Lac > Ni–AOPAN–Lac > Cd–AOPAN–Lac. In addition, the immobilized enzyme on the carrier of AOPAN chelated with four mixed metal ions showed the best properties.

  16. Metal Immobilization Influence On Bioavailability And Remediation For Urban Environments

    Science.gov (United States)

    Immobilization of soil contaminants, such as lead, via phosphate amendments to alter the chemical environment of metals into highly insoluble forms is a well established process. The literature has documented numerous examples of highly contaminated Pb sites at shooting ranges, b...

  17. Heavy metal immobilization in mineral phases

    International Nuclear Information System (INIS)

    Apblett, A.

    1993-01-01

    A successful waste form for toxic or radioactive metals must not only have the ability to chemically incorporate the elements but it must also be extremely stable in the geological environment. Thus, ceramic wasteforms are sought which mimic those minerals that have sequestered the hazardous metals for billions of years. One method for producing ceramics, metal organic deposition (MOD) is outstanding in its simplicity, versatility, and inexpensiveness. The major contribution that the MOD process can make to ceramic waste forms is the ability to mix the toxic metals at a molecular level with the elements which form the ceramic matrix. With proper choice of organic ligands, the inclusion of significant amounts of alkali metals in the ceramic and, hence, their detrimental effect on durability may be avoided. In the first stage of our research we identified thermally-unstable ligands which could fulfill the role of complexing toxic metal species and allowing their precipitation or extraction into nonaqueous solvents

  18. Synchrotron Analysis Of Metal Immobilization In Sediments

    Science.gov (United States)

    Heavy metal contamination is a problem at many marine and fresh water environments as a result of industrial and military activities. Metals such as lead (Pb), zinc (Zn), copper (Cu), and chromium (Cr) are common contaminants in sediments due to many Navy activities. The mobile...

  19. Novel synthesis and applications of Thiomer solidification for heavy metals immobilization in hazardous ASR/ISW thermal residue.

    Science.gov (United States)

    Baek, Jin Woong; Mallampati, Srinivasa Reddy; Park, Hung Suck

    2016-03-01

    The present paper reports the novel synthesis and application of Thiomer solidification for heavy metal immobilization in hazardous automobile shredder residues and industrial solid waste (ASR/ISW) thermal residues. The word Thiomer is a combination of the prefix of a sulfur-containing compound "Thio" and the suffix of "Polymer" meaning a large molecule compound of many repeated subunits. To immobilize heavy metals, either ASR/ISW thermal residues (including bottom and fly ash) was mixed well with Thiomer and heated at 140°C. After Thiomer solidification, approximately 91-100% heavy metal immobilization was achieved. The morphology and mineral phases of the Thiomer-solidified ASR/ISW thermal residue were characterized by field emission-scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction (XRD), which indicated that the amounts of heavy metals detectable on the ASR/ISW thermal residue surface decreased and the sulfur mass percent increased. XRD indicated that the main fraction of the enclosed/bound materials on the ASR/ISW residue contained sulfur associated crystalline complexes. The Thiomer solidified process could convert the heavy metal compounds into highly insoluble metal sulfides and simultaneously encapsulate the ASR/ISW thermal residue. These results show that the proposed method can be applied to the immobilization of ASR/ISW hazardous ash involving heavy metals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Thin films of mixed metal compounds

    Science.gov (United States)

    Mickelsen, Reid A.; Chen, Wen S.

    1985-01-01

    A compositionally uniform thin film of a mixed metal compound is formed by simultaneously evaporating a first metal compound and a second metal compound from independent sources. The mean free path between the vapor particles is reduced by a gas and the mixed vapors are deposited uniformly. The invention finds particular utility in forming thin film heterojunction solar cells.

  1. Effect of new soil metal immobilizing agents on metal toxicity to terrestrial invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Lock, K.; Janssen, C.R

    2003-01-01

    Organisms with different exposure routes should be used to simultaneously assess risks of metals in soils. - Application of 5% (w:w) novel metal immobilizing agent reduced the water soluble, the calcium chloride extracted as well as the pore water concentration of zinc in soils from Maatheide, a metal contaminated site in the northeast of Belgium. Addition of the metal immobilizing agents also eliminated acute toxicity to the potworm Enchytraeus albidus and the earthworm Eisenia fetida and chronic toxicity to the springtail Folsomia candida. Cocoon production by E. fetida, however, was still adversely affected. These differences may be explained by the species dependent routes of metal uptake: F. candida is probably mainly exposed via pore water while in E. fetida dietary exposure is probably also important. From these results it is clear that organisms with different exposure routes should be used simultaneously to assess the environmental risk of metal contaminated soils.

  2. New Approach for Fractioning Metal Compounds Studies in Soils

    Science.gov (United States)

    Minkina, Tatiana; Motuzova, Galina; Mandzhieva, Saglara; Bauer, Tatiana; Burachevskaya, Marina; Sushkova, Svetlana; Nevidomskaya, Dina; Kalinitchenko, Valeriy

    2016-04-01

    -silicate minerals. The amount of the applied metals fixed in the lattices of the silicate minerals is insignificant. Hence, all the soil components participate in the loose and firm fixation of the metals. The leading role in mobilization-immobilization of natural metal compounds in the ordinary chernozem belongs to carbonates and silicate minerals. For exogenic metal compounds, this role belongs to the soil organic matter and Fe-Mn oxides and hydroxides. The obtained data are important for ecology because they enable us to predict the transformation of soil components responsible for metal fixation and the possibility of their secondary mobilization. The danger of metal mobilization is more probable for metal compounds with organic substances that are particularly active in the loose binding of the introduced metals. This work was supported by the Ministry of Science of the Russian Federation, project no. 5.885.2014/K, the Russian Foundation for Basic Research, projects no. № 14-05-00586_a.

  3. Immobilization of Bacillus sp. in mesoporous activated carbon for degradation of sulphonated phenolic compound in wastewater.

    Science.gov (United States)

    Sekaran, G; Karthikeyan, S; Gupta, V K; Boopathy, R; Maharaja, P

    2013-03-01

    Xenobiotic compounds are used in considerable quantities in leather industries besides natural organic and inorganic compounds. These compounds resist biological degradation and thus they remain in the treated wastewater in the unaltered molecular configurations. Immobilization of organisms in carrier matrices protects them from shock load application and from the toxicity of chemicals in bulk liquid phase. Mesoporous activated carbon (MAC) has been considered in the present study as the carrier matrix for the immobilization of Bacillus sp. isolated from Effluent Treatment Plant (ETP) employed for the treatment of wastewater containing sulphonated phenolic (SP) compounds. Temperature, pH, concentration, particle size and mass of MAC were observed to influence the immobilization behavior of Bacillus sp. The percentage immobilization of Bacillus sp. was the maximum at pH 7.0, temperature 20 °C and at particle size 300 μm. Enthalpy, free energy and entropy of immobilization were -46.9 kJ mol(-1), -1.19 kJ mol(-1) and -161.36 JK(-1)mol(-1) respectively at pH 7.0, temperature 20 °C and particle size 300 μm. Higher values of ΔH(0) indicate the firm bonding of the Bacillus sp. in MAC. Degradation of aqueous sulphonated phenolic compound by Bacillus sp. immobilized in MAC followed pseudo first order rate kinetics with rate constant 1.12 × 10(-2) min(-1). Copyright © 2012 Elsevier B.V. All rights reserved.

  4. The mechanisms of heavy metal immobilization by cementitious material treatments and thermal treatments: A review.

    Science.gov (United States)

    Guo, Bin; Liu, Bo; Yang, Jian; Zhang, Shengen

    2017-05-15

    Safe disposal of solid wastes containing heavy metals is a significant task for environment protection. Immobilization treatment is an effective technology to achieve this task. Cementitious material treatments and thermal treatments are two types of attractive immobilization treatments due to that the heavy metals could be encapsulated in their dense and durable wasteforms. This paper discusses the heavy metal immobilization mechanisms of these methods in detail. Physical encapsulation and chemical stabilization are two fundamental mechanisms that occur simultaneously during the immobilization processes. After immobilization treatments, the wasteforms build up a low permeable barrier for the contaminations. This reduces the exposed surface of wastes. Chemical stabilization occurs when the heavy metals transform into more stable and less soluble metal bearing phases. The heavy metal bearing phases in the wasteforms are also reviewed in this paper. If the heavy metals are incorporated into more stable and less soluble metal bearing phases, the potential hazards of heavy metals will be lower. Thus, converting heavy metals into more stable phases during immobilization processes should be a common way to enhance the immobilization effect of these immobilization methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Occurrence of tributyltin compounds and characteristics of heavy metals

    International Nuclear Information System (INIS)

    Sheikh, M. A.; Oomori, T.; Noah, N. M.; Tsuha, K.

    2007-01-01

    Surface sediment samples were collected from Tanzanian major commercial ports and studied for the distribution and behavior of tributyltin compounds and heavy metals. The content of tributyltin in sediments ranged from ND-3670 ng (Sn) g 1 dry wt (1 780 ± 1720) (Mean ± SD) at Zanzibar and from ND-16700 ng (Sn)g 1 dry wt (4080 ± 7540) at Dar Es Salaam ports, respectively. Maximum tributyltin levels were detected inside the both ports. Metabolic degradation of butyltin compounds showed that MBT + DBT > TBT %, this may be attributed by the warm ambient water and intense sunlight in the tropical regions. A sequential extraction procedure was undertaken to provide detailed chemical characteristics of heavy metals in the sediments. The procedure revealed that about 50 % of Fe in the both ports is in immobile fraction (residual fraction) while other metals; Cd, Cu, Ni, Co, Zn, Pb. and Mn were mostly found in exchangeable or carbonate fractions and thus can be easily remobilized and enter the aquatic food chain. This paper provides basic information of tributyltin compounds contamination and chemical characteristics of heavy metals in the marine ecosystem in Tanzania. To our knowledge, this is the first documentation of Organotin compounds in marine environments in East Africa and suggests the importance of further detailed Organotin compounds studies in other sub-Saharan Africa regions

  6. Immobilization of Bacillus sp. in mesoporous activated carbon for degradation of sulphonated phenolic compound in wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Sekaran, G., E-mail: ganesansekaran@gmail.com [Environmental Technology Division, Council of Scientific and Industrial Research (CSIR), Central Leather Research Institute (CLRI), Adyar, Chennai-600 020 (India); Karthikeyan, S. [Environmental Technology Division, Council of Scientific and Industrial Research (CSIR), Central Leather Research Institute (CLRI), Adyar, Chennai-600 020 (India); Gupta, V.K. [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee-247 667 (India); Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Boopathy, R.; Maharaja, P. [Environmental Technology Division, Council of Scientific and Industrial Research (CSIR), Central Leather Research Institute (CLRI), Adyar, Chennai-600 020 (India)

    2013-03-01

    Xenobiotic compounds are used in considerable quantities in leather industries besides natural organic and inorganic compounds. These compounds resist biological degradation and thus they remain in the treated wastewater in the unaltered molecular configurations. Immobilization of organisms in carrier matrices protects them from shock load application and from the toxicity of chemicals in bulk liquid phase. Mesoporous activated carbon (MAC) has been considered in the present study as the carrier matrix for the immobilization of Bacillus sp. isolated from Effluent Treatment Plant (ETP) employed for the treatment of wastewater containing sulphonated phenolic (SP) compounds. Temperature, pH, concentration, particle size and mass of MAC were observed to influence the immobilization behavior of Bacillus sp. The percentage immobilization of Bacillus sp. was the maximum at pH 7.0, temperature 20 Degree-Sign C and at particle size 300 {mu}m. Enthalpy, free energy and entropy of immobilization were - 46.9 kJ mol{sup -1}, - 1.19 kJ mol{sup -1} and - 161.36 J K{sup -1} mol{sup -1} respectively at pH 7.0, temperature 20 Degree-Sign C and particle size 300 {mu}m. Higher values of {Delta}H{sup 0} indicate the firm bonding of the Bacillus sp. in MAC. Degradation of aqueous sulphonated phenolic compound by Bacillus sp. immobilized in MAC followed pseudo first order rate kinetics with rate constant 1.12 Multiplication-Sign 10{sup -2} min{sup -1}. Highlights: Black-Right-Pointing-Pointer Degradation on phenolic syntan using immobilized activated carbon as catalyst. Black-Right-Pointing-Pointer Bacillus sp. immobilized cell reactor removed all refractory organic loads. Black-Right-Pointing-Pointer The removal mechanism is due to co-metabolism between carbon and organisms. Black-Right-Pointing-Pointer The organics are completely metabolized rather than adsorption.

  7. Thin films of metal-organic compounds and metal nanoparticle

    Indian Academy of Sciences (India)

    Thin films of metal-organic compounds and metal nanoparticle-embedded polymers for nonlinear optical applications. S Philip Anthony Shatabdi Porel D ... Thin films based on two very different metal-organic systems are developed and some nonlinear optical applications are explored. A family of zinc complexes which ...

  8. Immobilization of krypton in a metallic matrix by combined ion implantation and sputtering

    International Nuclear Information System (INIS)

    Whitmell, D.S.

    1980-01-01

    With the increase in nuclear power, it may be necessary to contain for 100 to 200 years the radioactive 85 krypton released during fuel reprocessing. The ideal method of immobilizing radioactive materials is in the form of stable, monolithic solids which are resistant to the effects of the environment or accidents, and which can retain the radioactivity under all envisaged conditions. Since krypton is a rare gas, not forming thermally stable compounds, conventional methods of storage are not possible. A process is being developed to immobilize the krypton in the form of small gas bubbles in a metal matrix by implanting the gas into a metal layer from a glow discharge and then burying the implanted layer by sputter deposition. By repeating the process, a thick layer of deposit is built up with the krypton dispersed throughout the matrix as bubbles of diameter less than 20 A. This process offers an ideal form of storage since gas in bubbles is not thermally released until the temperature of the matrix is close to the melting point, and also leakage of gas by corrosion or mechanical damage will be small. A pilot plant is being built in order to demonstrate the process on a scale comparable with that required for a reprocessing plant. The efficiency of the process is dependent upon the amount of gas which can be implanted at low energy into a thin layer and its subsequent retention. (author)

  9. Immobilization of radionuclides and heavy metals through anaerobic bio-oxidation of Fe(II)

    International Nuclear Information System (INIS)

    Lack, J.G.; Chaudhuri, S.K.; Kelly, S.D.; Kemner, K.M.; O'Connor, S.M.; Coates, J.D.

    2002-01-01

    Adsorption of heavy metals and radionuclides (HMR) onto iron and manganese oxides has long been recognized as an important reaction for the immobilization of these compounds. However, in environments containing elevated concentrations of these HMR the adsorptive capacity of the iron and manganese oxides may well be exceeded, and the HMR can migrate as soluble compounds in aqueous systems. Here we demonstrate the potential of a bioremediative strategy for HMR stabilization in reducing environments based on the recently described anaerobic nitrate-dependent Fe(II) oxidation by Dechlorosoma species. Bio-oxidation of 10 mM Fe(II) and precipitation of Fe(III) oxides by these organisms resulted in rapid adsorption and removal of 55 μM uranium and 81 μM cobalt from solution. The adsorptive capacity of the biogenic Fe(III) oxides was lower than that of abiotically produced Fe(III) oxides (100 μM for both metals), which may have been a result of steric hindrance by the microbial cells on the iron oxide surfaces. The binding capacity of the biogenic oxides for different heavy metals was indirectly correlated to the atomic radius of the bound element. X-ray absorption spectroscopy indicated that the uranium was bound to the biogenically produced Fe(III) oxides as U(VI) and that the U(VI) formed bidentate and tridentate inner-sphere complexes with the Fe(III) oxide surfaces. Dechlorosoma suillum oxidation was specific for Fe(II), and the organism did not enzymatically oxidize U(IV) or Co(II). Small amounts (less than 2.5 μM) of Cr(III) were reoxidized by D. suillum; however, this appeared to be inversely dependent on the initial concentration of the Cr(III). The results of this study demonstrate the potential of this novel approach for stabilization and immobilization of HMR in the environment.

  10. Magnesium Potassium Phosphate Compound for Immobilization of Radioactive Waste Containing Actinide and Rare Earth Elements

    Directory of Open Access Journals (Sweden)

    Sergey E. Vinokurov

    2018-06-01

    Full Text Available The problem of effective immobilization of liquid radioactive waste (LRW is key to the successful development of nuclear energy. The possibility of using the magnesium potassium phosphate (MKP compound for LRW immobilization on the example of nitric acid solutions containing actinides and rare earth elements (REE, including high level waste (HLW surrogate solution, is considered in the research work. Under the study of phase composition and structure of the MKP compounds that is obtained by the XRD and SEM methods, it was established that the compounds are composed of crystalline phases—analogues of natural phosphate minerals (struvite, metaankoleite. The hydrolytic stability of the compounds was determined according to the semi-dynamic test GOST R 52126-2003. Low leaching rates of radionuclides from the compound are established, including a differential leaching rate of 239Pu and 241Am—3.5 × 10−7 and 5.3 × 10−7 g/(cm2∙day. As a result of the research work, it was concluded that the MKP compound is promising for LRW immobilization and can become an alternative material combining the advantages of easy implementation of the technology, like cementation and the high physical and chemical stability corresponding to a glass-like compound.

  11. Studies of Metal-Metal Bonded Compounds in Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Berry, John F. [Univ. of Wisconsin, Madison, WI (United States)

    2018-01-19

    The overall goals of this research are (1) to define the fundamental coordination chemistry underlying successful catalytic transformations promoted by metal-metal bonded compounds, and (2) to explore new chemical transformations that occur at metal-metal bonded sites that could lead to the discovery of new catalytic processes. Transformations of interest include metal-promoted reactions of carbene, nitrene, or nitrido species to yield products with new C–C and C–N bonds, respectively. The most promising suite of transition metal catalysts for these transformations is the set of metal-metal bonded coordination compounds of Ru and Rh of the general formula M2(ligand)4, where M = Ru or Rh and ligand = a monoanionic, bridging ligand such as acetate. Development of new catalysts and improvement of catalytic conditions have been stymied by a general lack of knowledge about the nature of highly reactive intermediates in these reactions, the knowledge that is to be supplied by this work. Our three specific objectives for this year have been (A) to trap, isolate, and characterize new reactive intermediates of general relevance to catalysis, (B) to explore the electronic structure and reactivity of these unusual species, and how these two properties are interrelated, and (C) to use our obtained mechanistic knowledge to design new catalysts with a focus on Earth-abundant first-row transition metal compounds.

  12. Crystallochemistry of rhenium compounds with metal-metal bonds

    International Nuclear Information System (INIS)

    Koz'min, P.A.; Surazhskaya, M.D.

    1980-01-01

    A review is presented including a brief description of atomic structure of 59 coordination rhenium compounds with metal-metal bond. The most important bond lengths and valent angles are presented for each compound. The dependence of rhenium-rhenium bond length on its multiplicity is discussed and possible causes of deviations from this dependence (namely, axial ligand presence, steric repulsion of ligands) are considered. On the basis of qualitative comparison of electronegativity of ligands in dimer compounds with quarternary bond of rhenium-rhenium a supposition is made on the influence of formal charge of atomic group and summary electro-negativity of ligands on the possibility of the metal-metal bond formation

  13. Studies of Immobilized Homogeneous Metal Catalysts on Silica Supports

    Energy Technology Data Exchange (ETDEWEB)

    Stanger, Keith James [Iowa State Univ., Ames, IA (United States)

    2003-01-01

    The tethered, chiral, chelating diphosphine rhodium complex, which catalyzes the enantioselective hydrogenation of methyl-α-acetamidocinnamate (MAC), has the illustrated structure as established by 31P NMR and IR studies. Spectral and catalytic investigations also suggest that the mechanism of action of the tethered complex is the same as that of the untethered complex in solution. The rhodium complexes, [Rh(COD)H]4, [Rh(COD)2]+BF4-, [Rh(COD)Cl]2, and RhCl3• 3H2O, adsorbed on SiO2 are optimally activated for toluene hydrogenation by pretreatment with H2 at 200 C. The same complexes on Pd-SiO2 are equally active without pretreatments. The active species in all cases is rhodium metal. The catalysts were characterized by XPS, TEM, DRIFTS, and mercury poisoning experiments. Rhodium on silica catalyzes the hydrogenation of fluorobenzene to produce predominantly fluorocyclohexane in heptane and 1,2-dichloroethane solvents. In heptane/methanol and heptane/water solvents, hydrodefluorination to benzene and subsequent hydrogenation to cyclohexane occurs exclusively. Benzene inhibits the hydrodefluorination of fluorobenzene. In DCE or heptane solvents, fluorocyclohexane reacts with hydrogen fluoride to form cyclohexene. Reaction conditions can be chosen to selectively yield fluorocyclohexane, cyclohexene, benzene, or cyclohexane. The oxorhenium(V) dithiolate catalyst [-S(CH2)3s-]Re(O)(Me)(PPh3) was modified by linking it to a tether that could be attached to a silica support. Spectroscopic investigation and catalytic oxidation reactivity showed the heterogenized catalyst's structure and reactivity to be similar to its homogeneous analog. However, the immobilized catalyst offered additional advantages of recyclability, extended stability, and increased resistance to deactivation.

  14. Application of carbon nanotubes to immobilize heavy metals in contaminated soils

    International Nuclear Information System (INIS)

    Matos, Martim P. S. R.; Correia, António Alberto S.; Rasteiro, Maria G.

    2017-01-01

    The contamination of soils with heavy metals is a growing concern in modern societies. To avoid the spread of contamination, soil stabilization techniques can be applied mixing materials with the soil in order to partially immobilize heavy metals. Carbon nanotubes (CNTs) are nanomaterials known for its exceptional properties, like high surface area and adsorption capacity. Due to these unique properties, the potential use of CNTs in heavy metal contaminated water has been studied, with very satisfactory results; however, their application in contaminated soils is practically unexplored. This experimental work is focused on studying the potential of using CNTs in soil remediation, especially to immobilize the heavy metals ions: lead (Pb"2"+), copper (Cu"2"+), nickel (Ni"2"+), and zinc (Zn"2"+), commonly present in contaminated soils. In order to avoid CNT agglomeration, which originates the loss of their beneficial properties, an aqueous suspension of CNTs was prepared using a non-ionic surfactant combined with ultrasonic energy to promote CNTs dispersion. Then, the soil, with and without the addition of CNTs, was subjected to adsorption tests to evaluate the CNT capacity to improve heavy metal immobilization. To validate the adsorption test results, permeability tests were executed, simulating the conditions of a real-case scenario. The results obtained led to the conclusion that the addition of a small amount of dispersed CNTs can successfully increase the adsorption capacity of the soil and consequently improve the immobilization of heavy metals in the soil matrix. The immobilization percentage varies with the different heavy metals under study.

  15. Application of carbon nanotubes to immobilize heavy metals in contaminated soils

    Science.gov (United States)

    Matos, Martim P. S. R.; Correia, António Alberto S.; Rasteiro, Maria G.

    2017-04-01

    The contamination of soils with heavy metals is a growing concern in modern societies. To avoid the spread of contamination, soil stabilization techniques can be applied mixing materials with the soil in order to partially immobilize heavy metals. Carbon nanotubes (CNTs) are nanomaterials known for its exceptional properties, like high surface area and adsorption capacity. Due to these unique properties, the potential use of CNTs in heavy metal contaminated water has been studied, with very satisfactory results; however, their application in contaminated soils is practically unexplored. This experimental work is focused on studying the potential of using CNTs in soil remediation, especially to immobilize the heavy metals ions: lead (Pb2+), copper (Cu2+), nickel (Ni2+), and zinc (Zn2+), commonly present in contaminated soils. In order to avoid CNT agglomeration, which originates the loss of their beneficial properties, an aqueous suspension of CNTs was prepared using a non-ionic surfactant combined with ultrasonic energy to promote CNTs dispersion. Then, the soil, with and without the addition of CNTs, was subjected to adsorption tests to evaluate the CNT capacity to improve heavy metal immobilization. To validate the adsorption test results, permeability tests were executed, simulating the conditions of a real-case scenario. The results obtained led to the conclusion that the addition of a small amount of dispersed CNTs can successfully increase the adsorption capacity of the soil and consequently improve the immobilization of heavy metals in the soil matrix. The immobilization percentage varies with the different heavy metals under study.

  16. Remediation of heavy metal(loid)s contaminated soils--to mobilize or to immobilize?

    Science.gov (United States)

    Bolan, Nanthi; Kunhikrishnan, Anitha; Thangarajan, Ramya; Kumpiene, Jurate; Park, Jinhee; Makino, Tomoyuki; Kirkham, Mary Beth; Scheckel, Kirk

    2014-02-15

    Unlike organic contaminants, metal(loid)s do not undergo microbial or chemical degradation and persist for a long time after their introduction. Bioavailability of metal(loid)s plays a vital role in the remediation of contaminated soils. In this review, the remediation of heavy metal(loid) contaminated soils through manipulating their bioavailability using a range of soil amendments will be presented. Mobilizing amendments such as chelating and desorbing agents increase the bioavailability and mobility of metal(loid)s. Immobilizing amendments such of precipitating agents and sorbent materials decrease the bioavailabilty and mobility of metal(loid)s. Mobilizing agents can be used to enhance the removal of heavy metal(loid)s though plant uptake and soil washing. Immobilizing agents can be used to reduce the transfer to metal(loid)s to food chain via plant uptake and leaching to groundwater. One of the major limitations of mobilizing technique is susceptibility to leaching of the mobilized heavy metal(loid)s in the absence of active plant uptake. Similarly, in the case of the immobilization technique the long-term stability of the immobilized heavy metal(loid)s needs to be monitored. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Solidification and Immobilization of Heavy metals in Soil using with nano-metallic Ca/CaO Dispersion Mixture

    Directory of Open Access Journals (Sweden)

    Mallampati S. R.

    2013-04-01

    Full Text Available In the present work, the use of nano-metallic calcium (Ca and calcium oxide (CaO dispersion mixture for the immobilization of heavy metals (As, Cd, Cr and Pb in soil was investigated. With simple grinding, 85-90% of heavy metals immobilization could be achieved, while it could be enhanced to 98-100% by grinding with the addition of nano-metallic Ca/CaO dispersion mixture. By SEM-EDS elemental maps as well as semi-quantitative analysis observed that the amount of As, Cd, Cr and Pb measurable on soil particle surface decreases after nano-metallic Ca/CaO treatment. The leachable heavy metals concentrations were reduced, to the concentration lower than the Japan soil elution standard regulatory threshold, i. e., < 0.01 mg/l for As, Cd and Pb and 0.05mg/l for Cr. Whereas, the effect of soil moisture and pH on heavy metals immobilization was not much influenced. The results suggest that nano-metallic Ca/CaO mixture is suitable to be used for the gentle immobilization of heavy metals contaminated soil at normal moisture conditions.

  18. Immobilizer-assisted management of metal-contaminated agricultural soils for safer food production.

    Science.gov (United States)

    Kim, Kwon-Rae; Kim, Jeong-Gyu; Park, Jeong-Sik; Kim, Min-Suk; Owens, Gary; Youn, Gyu-Hoon; Lee, Jin-Su

    2012-07-15

    Production of food crops on metal contaminated agricultural soils is of concern because consumers are potentially exposed to hazardous metals via dietary intake of such crops or crop derived products. Therefore, the current study was conducted to develop management protocols for crop cultivation to allow safer food production. Metal uptake, as influenced by pH change-induced immobilizing agents (dolomite, steel slag, and agricultural lime) and sorption agents (zeolite and compost), was monitored in three common plants representative of leafy (Chinese cabbage), root (spring onion) and fruit (red pepper) vegetables, in a field experiment. The efficiency of the immobilizing agents was assessed by their ability to decrease the phytoavailability of metals (Cd, Pb, and Zn). The fruit vegetable (red pepper) showed the least accumulation of Cd (0.16-0.29 mgkg(-1) DW) and Pb (0.2-0.9 mgkg(-1) DW) in edible parts regardless of treatment, indicating selection of low metal accumulating crops was a reasonable strategy for safer food production. However, safer food production was more likely to be achievable by combining crop selection with immobilizing agent amendment of soils. Among the immobilizing agents, pH change-induced immobilizers were more effective than sorption agents, showing decreases in Cd and Pb concentrations in each plant well below standard limits. The efficiency of pH change-induced immobilizers was also comparable to reductions obtained by 'clean soil cover' where the total metal concentrations of the plow layer was reduced via capping the surface with uncontaminated soil, implying that pH change-induced immobilizers can be practically applied to metal contaminated agricultural soils for safer food production. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Compounds with magnetoplumbite or SLNA type structure as materials for nuclear waste immobilization

    International Nuclear Information System (INIS)

    Thery, J.; Vivien, D.; Lejus, A.M.; Collongues, R.

    1985-01-01

    Magnetoplumbite-like structure, and related phases (sodium-lanthanide aluminates: SLNA) are able to accommodate a wide range of elements with various charges and ionic radii. The available coordinences are 4, 5 or 6 for the small cations and 9 or 12 for the large ones. This kind of compounds, which in addition present good chemical inertia, could possibly be used for the immobilization of nuclear waste [fr

  20. Immobilized periphytic cyanobacteria for removal of nitrogenous compounds and phosphorus from shrimp farm wastewater

    OpenAIRE

    BANERJEE, SANJOY; KHATOON, HELENA; SHARIFF, MOHAMED; YUSOFF, FATIMAH

    2015-01-01

    Cyanobacteria can be used to remove nitrogenous compounds from wastewater, but a major bottleneck in the process is the separation of cyanobacterial biomass from the treated water discharge, which may cause eutrophication. The current study assessed the suitability of three periphytic cyanobacteria (Geitlerinema sp., Gloeotrichia sp., and Lyngbya sp.) isolated from shrimp ponds. These cyanobacteria were immobilized by self-adhesion to polyvinyl chloride sheets, forming mats, and were screened...

  1. Enrichment and characterization of phosphopeptides by immobilized metal affinity chromatography (IMAC) and mass spectrometry

    DEFF Research Database (Denmark)

    Thingholm, Tine E; Jensen, Ole N

    2009-01-01

    The combination of immobilized metal affinity chromatography (IMAC) and mass spectrometry is a widely used technique for enrichment and sequencing of phosphopeptides. In the IMAC method, negatively charged phosphate groups interact with positively charged metal ions (Fe3+, Ga3+, and Al3...

  2. Immobilized poly-L-histidine for chelation of metal cations and metal oxyanions

    International Nuclear Information System (INIS)

    Malachowski, Lisa; Holcombe, James A.

    2003-01-01

    The biohomopolymer poly-L-histidine (PLHis) was immobilized onto controlled pore glass (CPG) and its metal binding capabilities evaluated through the use of a flow injection-flame atomic absorption system. The metal binding capability of PLHis-CPG was determined through the analysis of the generated breakthrough curves. The polymer likely coordinates cationic metals through the imidazole side chain (pK a ∼6) present on each histidine residue with both strong and weak binding sites for Cu 2+ , Cd 2+ , Co 2+ , and Ni 2+ . Weak to minimal binding was observed for Mn 2+ , Ca 2+ , Mg 2+ , Na + , and Cr 3+ . The bound metals are quantitatively released from the column with an acid strip. It has also been shown that the protonated imidazole side chain present in acidic solutions is capable of binding metal oxyanions such as chromates, arsenates, and selenites; although oxyanion binding currently exhibits interferences from competing anions in solution, such as sulfate and nitrate. The interference in oxyanion binding is less severe in the presence of chloride, phosphate, and acetate. PLHis-CPG exhibits a capacity of ∼30 μmol Cu 2+ /g CPG in neutral to basic conditions, and a capacity of ∼70 μmol Cr(VI)/g CPG, ∼4 μmol As(V)/g CPG, and ∼4 μmol Se(IV)/g CPG in acidic conditions

  3. Heavy metal-immobilizing organoclay facilitates polycyclic aromatic hydrocarbon biodegradation in mixed-contaminated soil

    International Nuclear Information System (INIS)

    Biswas, Bhabananda; Sarkar, Binoy; Mandal, Asit; Naidu, Ravi

    2015-01-01

    Highlights: • A novel metal-immobilizing organoclay (MIOC) synthesized and characterized. • MIOC immobilizes toxic metals and reduces metal bioavailability. • It enhances PAH-bioavailability to soil bacteria. • It improves microbial growth and activities in mixed-contaminated soils. • MIOC facilitates PAH-biodegradation in metal co-contaminated soils. - Abstract: Soils contaminated with a mixture of heavy metals and polycyclic aromatic hydrocarbons (PAHs) pose toxic metal stress to native PAH-degrading microorganisms. Adsorbents such as clay and modified clay minerals can bind the metal and reduce its toxicity to microorganisms. However, in a mixed-contaminated soil, an adsorption process more specific to the metals without affecting the bioavailability of PAHs is desired for effective degradation. Furthermore, the adsorbent should enhance the viability of PAH-degrading microorganisms. A metal-immobilizing organoclay (Arquad ® 2HT-75-bentonite treated with palmitic acid) (MIOC) able to reduce metal (cadmium (Cd)) toxicity and enhance PAH (phenanthrene) biodegradation was developed and characterized in this study. The MIOC differed considerably from the parent clay in terms of its ability to reduce metal toxicity (MIOC > unmodified bentonite > Arquad–bentonite). The MIOC variably increased the microbial count (10–43%) as well as activities (respiration 3–44%; enzymatic activities up to 68%), and simultaneously maintained phenanthrene in bioavailable form in a Cd-phenanthrene mixed-contaminated soil over a 21-day incubation period. This study may lead to a new MIOC-assisted bioremediation technique for PAHs in mixed-contaminated soils

  4. Mutagenic activities of metal compounds in bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Nishioka, H

    1975-01-01

    Environmental contaminations by certain metal compounds are bringing about serious problems to human health, including genetic hazards. It has been reported that some compounds of iron, manganese and mercury induce point mutations in microorganisms. Also it has been observed that those of aluminum, antimony, arsenic, cadmium, lead and tellurium cause chromosome aberrations in plants, insects and cultured human cells. The mechanism of mutation induction by these metals remains, however, still obscure. For screening of chemical mutagens, Kada et al, recently developed a simple and efficient method named rec-assay by observing differential growth sensitivities to drugs in wild and recombination-deficient strains of Bacillus subtilis. When a chemical is more inhibitory for Rec/sup -/ than for Rec/sup +/ cells, it is reasonable to suspect mutagenicity based on its DNA-damaging capacity. In the present report, 56 metal compounds were tested by the rec-assay. Compounds showing positive results in the assay such as potassium dichromate (K/sub 2/Cr/sub 2/O/sub 7/), ammonium molybdate ((NH/sub 4/)/sub 6/Mo/sub 7/O/sub 24/) and sodium arsenite (NaAsO/sub 2/) were then examined as to their capacities to induce reversions in E. coli Trp/sup -/ strains possessing different DNA repair pathways. 11 references, 3 tables.

  5. Application of carbon nanotubes to immobilize heavy metals in contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Matos, Martim P. S. R.; Correia, António Alberto S., E-mail: aalberto@dec.uc.pt [University of Coimbra, Department of Civil Engineering, CIEPQPF—Chemical Process Engineering and Forest Products Research Centre (Portugal); Rasteiro, Maria G. [University of Coimbra, Department of Chemical Engineering, CIEPQPF (Portugal)

    2017-04-15

    The contamination of soils with heavy metals is a growing concern in modern societies. To avoid the spread of contamination, soil stabilization techniques can be applied mixing materials with the soil in order to partially immobilize heavy metals. Carbon nanotubes (CNTs) are nanomaterials known for its exceptional properties, like high surface area and adsorption capacity. Due to these unique properties, the potential use of CNTs in heavy metal contaminated water has been studied, with very satisfactory results; however, their application in contaminated soils is practically unexplored. This experimental work is focused on studying the potential of using CNTs in soil remediation, especially to immobilize the heavy metals ions: lead (Pb{sup 2+}), copper (Cu{sup 2+}), nickel (Ni{sup 2+}), and zinc (Zn{sup 2+}), commonly present in contaminated soils. In order to avoid CNT agglomeration, which originates the loss of their beneficial properties, an aqueous suspension of CNTs was prepared using a non-ionic surfactant combined with ultrasonic energy to promote CNTs dispersion. Then, the soil, with and without the addition of CNTs, was subjected to adsorption tests to evaluate the CNT capacity to improve heavy metal immobilization. To validate the adsorption test results, permeability tests were executed, simulating the conditions of a real-case scenario. The results obtained led to the conclusion that the addition of a small amount of dispersed CNTs can successfully increase the adsorption capacity of the soil and consequently improve the immobilization of heavy metals in the soil matrix. The immobilization percentage varies with the different heavy metals under study.

  6. Immobilization of heavy metals on pillared montmorillonite with a grafted chelate ligand

    International Nuclear Information System (INIS)

    Brown, Loren; Seaton, Kenneth; Mohseni, Ray; Vasiliev, Aleksey

    2013-01-01

    Highlights: • Mesoporous organoclay for immobilization of heavy metal cations was obtained. • The material has a porous structure with high contents of surface adsorption sites. • Leaching of heavy metals from soil reduced in the presence of this adsorbent. • The adsorbent demonstrated high effectiveness in neutral and acidic media. -- Abstract: The objective of this work was the development of an efficient adsorbent for irreversible immobilization of heavy metals in contaminated soils. The adsorbent was prepared by pillaring of montmorillonite with silica followed by grafting of a chelate ligand on its surface. Obtained adsorbent was mesoporous with high content of adsorption sites. Its structure was studied by BET adsorption of N 2 , dynamic light scattering, and scanning electron microscopy. The adsorption capacity of the organoclay was measured by its mixing with contaminated kaolin and soil samples and by analysis of heavy metal contents in leachate. Deionized water and 50% acetic acid were used for leaching of metals from the samples. As it was demonstrated by the experiments, the adsorbent was efficient in immobilization of heavy metals not only in neutral aqueous media but also in the presence of weak acid. As a result, the adsorbent can be used for reduction of heavy metal leaching from contaminated sites

  7. Polyurethane and alginate immobilized algal biomass for the removal of aqueous toxic metals

    International Nuclear Information System (INIS)

    Fry, I.V.; Mehlhorn, R.J.

    1992-12-01

    We describe the development of immobilized, processed algal biomass for use as an adsorptive filter in the removal of toxic metals from waste water. To fabricate an adsorptive filter from precessed biomass several crucial criteria must be met, including: (1) high metal binding capacity, (2) long term stability (both mechanical and chemical), (3) selectivity for metals of concern (with regard to ionic competition), (4) acceptable flow capacity (to handle large volumes in short time frames), (5) stripping/regeneration (to recycle the adsorptive filter and concentrate the toxic metals to manageable volumes). This report documents experiments with processed algal biomass (Spirulina platensis and Spirulina maxima) immobilized in either alginate gel or preformed polyurethane foam. The adsorptive characteristics of these filters were assessed with regard to the criteria listed above

  8. Mutagenesis of metal compounds in bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Nishioka, H

    1974-01-01

    The mutagenic activity of 41 metal compounds was examined by applying the Rec-assay method with Bacillus subtilis H17 (rec/sup +/) and M45 (rec/sup -/) strains. Among these compounds, Na/sub 2/HAsO/sub 4/, CdCl/sub 2/, K/sub 2/CrO/sub 4/, K/sub 2/Cr/sub 2/O/sub 7/, CH/sub 3/HgCl, C/sub 2/H/sub 5/HgCl, CH/sub 3/COOHgC/sub 6/H/sub 5/, MnCl/sub 2/, MnNO/sub 3/, MnSO/sub 4/, Mn(CH/sub 3/COO)/sub 2/, (NH/sub 4/)/sub 2/MoO/sub 4/ and KMoO/sub 4/ showed positive results. The reactions of K/sub 2/Cr/sub 2/O/sub 7/ and (NH/sub 4/)/sub 2/MoO/sub 4/ were especially strong in the assay. Therefore, mutation induction to reversion (try/sup +/) and streptomycin resistance (SM/sup r/) of E. coli B/r WP2 try/sup -/ (hcl/sup +/ and hcr/sup -/) by the two compounds were examined by the following two experimental procedures. Stationary phase bacteria were exposed to the compounds at high concentrations (6.9 x 10/sup -3/ approx. 3.44 x 10/sup -2/M) in M9 buffer for 15 min at 37/sup -/ with shaking. After incubation at 37/sup 0/ for 48 h visible colonies on the plates were scored. Bacteria in M9 buffer were plated in media supplemented with low concentrations (1.7 x 10/sup -5/ approx. 3.4 x 10/sup -5/M) of the compounds. K/sub 2/Cr/sub 2/O/sub 7/ and (NH/sub 4/)/sub 2/MoO/sub 4/ increased the mutation rate of SM/sup r/ and try/sup +/ in both strains treated with either procedure. No marked differences in mutation rate were found between hcr/sup +/ and hcr/sup -/. After treatment with high concentrations of compounds one can imagine that a peroxidation state produced by these peroxides in the media might affect the killing and mutation induction. These results suggest the possibility that the mutagenesis of the metals relate to their atomic values, rather than the peroxidation state as far as these two compounds are concerned.

  9. Comparison of different transition metal ions for immobilized metal affinity chromatography of selenoprotein P from human plasma

    DEFF Research Database (Denmark)

    Sidenius, U; Farver, O; Jøns, O

    1999-01-01

    Cu2+, Ni2+, Zn2+, Co2+ and Cd2+ were evaluated in metal ion affinity chromatography for enrichment of selenoprotein P, and immobilized Co2+ affinity chromatography was found to be the most selective chromatographic method. The chromatography was performed by fast protein liquid chromatography...

  10. Multienzyme Immobilized Polymeric Membrane Reactor for the Transformation of a Lignin Model Compound

    Directory of Open Access Journals (Sweden)

    Rupam Sarma

    2018-04-01

    Full Text Available We have developed an integrated, multienzyme functionalized membrane reactor for bioconversion of a lignin model compound involving enzymatic catalysis. The membrane bioreactors were fabricated through the layer-by-layer assembly approach to immobilize three different enzymes (glucose oxidase, peroxidase and laccase into pH-responsive membranes. This novel membrane reactor couples the in situ generation of hydrogen peroxide (by glucose oxidase to oxidative conversion of a lignin model compound, guaiacylglycerol-β-guaiacyl ether (GGE. Preliminary investigation of the efficacy of these functional membranes towards GGE degradation is demonstrated under convective flow mode. Over 90% of the initial feed could be degraded with the multienzyme immobilized membranes at a residence time of approximately 22 s. GGE conversion product analysis revealed the formation of oligomeric oxidation products upon reaction with peroxidase, which may be a potential hazard to membrane bioreactors. These oxidation products could further be degraded by laccase enzymes in the multienzymatic membranes, explaining the potential of multi enzyme membrane reactors. The multienzyme incorporated membrane reactors were active for more than 30 days of storage time at 4 °C. During this time span, repetitive use of the membrane reactor was demonstrated involving 5–6 h of operation time for each cycle. The membrane reactor displayed encouraging performance, losing only 12% of its initial activity after multiple cycles of operation.

  11. Comparative assessment of heavy metal removal by immobilized ...

    African Journals Online (AJOL)

    Microorganisms play a vital role in heavy metal contaminated soil and wastewater by the mechanisms of biosorption. In this study, heavy metal resistant bacteria were isolated from an electroplating industrial effluent samples that uses copper, cadmium and lead for plating. These isolates were characterized to evaluate their ...

  12. Heavy metal-immobilizing organoclay facilitates polycyclic aromatic hydrocarbon biodegradation in mixed-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Bhabananda; Sarkar, Binoy [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, P.O. Box 486, Salisbury, SA 5106 (Australia); Mandal, Asit [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, SA 5095 (Australia); Division of Soil Biology, Indian Institute of Soil Science, Bhopal, Madhya Pradesh (India); Naidu, Ravi [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, P.O. Box 486, Salisbury, SA 5106 (Australia)

    2015-11-15

    Highlights: • A novel metal-immobilizing organoclay (MIOC) synthesized and characterized. • MIOC immobilizes toxic metals and reduces metal bioavailability. • It enhances PAH-bioavailability to soil bacteria. • It improves microbial growth and activities in mixed-contaminated soils. • MIOC facilitates PAH-biodegradation in metal co-contaminated soils. - Abstract: Soils contaminated with a mixture of heavy metals and polycyclic aromatic hydrocarbons (PAHs) pose toxic metal stress to native PAH-degrading microorganisms. Adsorbents such as clay and modified clay minerals can bind the metal and reduce its toxicity to microorganisms. However, in a mixed-contaminated soil, an adsorption process more specific to the metals without affecting the bioavailability of PAHs is desired for effective degradation. Furthermore, the adsorbent should enhance the viability of PAH-degrading microorganisms. A metal-immobilizing organoclay (Arquad{sup ®} 2HT-75-bentonite treated with palmitic acid) (MIOC) able to reduce metal (cadmium (Cd)) toxicity and enhance PAH (phenanthrene) biodegradation was developed and characterized in this study. The MIOC differed considerably from the parent clay in terms of its ability to reduce metal toxicity (MIOC > unmodified bentonite > Arquad–bentonite). The MIOC variably increased the microbial count (10–43%) as well as activities (respiration 3–44%; enzymatic activities up to 68%), and simultaneously maintained phenanthrene in bioavailable form in a Cd-phenanthrene mixed-contaminated soil over a 21-day incubation period. This study may lead to a new MIOC-assisted bioremediation technique for PAHs in mixed-contaminated soils.

  13. Metal-Chelate Immobilization of Lipase onto Polyethylenimine Coated MCM-41 for Apple Flavor Synthesis.

    Science.gov (United States)

    Sadighi, Armin; Motevalizadeh, Seyed Farshad; Hosseini, Morteza; Ramazani, Ali; Gorgannezhad, Lena; Nadri, Hamid; Deiham, Behnaz; Ganjali, Mohammad Reza; Shafiee, Abbas; Faramarzi, Mohammad Ali; Khoobi, Mehdi

    2017-08-01

    An enzyme immobilized on a mesoporous silica nanoparticle can serve as a multiple catalyst for the synthesis of industrially useful chemicals. In this work, MCM-41 nanoparticles were coated with polyethylenimine (MCM-41@PEI) and further modified by chelation of divalent metal ions (M = Co 2+ , Cu 2+ , or Pd 2+ ) to produce metal-chelated silica nanoparticles (MCM-41@PEI-M). Thermomyces lanuginosa lipase (TLL) was immobilized onto MCM-41, MCM-41@PEI, and MCM-41@PEI-M by physical adsorption. Maximum immobilization yield and efficiency of 75 ± 3.5 and 65 ± 2.7% were obtained for MCM@PEI-Co, respectively. The highest biocatalytic activity at extremely acidic and basic pH (pH = 3 and 10) values were achieved for MCM-PEI-Co and MCM-PEI-Cu, respectively. Optimum enzymatic activity was observed for MCM-41@PEI-Co at 75 °C, while immobilized lipase on the Co-chelated support retained 70% of its initial activity after 14 days of storage at room temperature. Due to its efficient catalytic performance, MCM-41@PEI-Co was selected for the synthesis of ethyl valerate in the presence of valeric acid and ethanol. The enzymatic esterification yield for immobilized lipase onto MCM-41@PEI-Co was 60 and 53%, respectively, after 24 h of incubation in n-hexane and dimethyl sulfoxide media. Graphical Abstract Divalent metal chelated polyethylenimine coated MCM-41 (MCM-41@PEI-M) was used for immobilization of Thermomyces lanuginosa lipase catalyzing green apple flavor preparation.

  14. Immobilization of metals in contaminated soils using natural polymer-based stabilizers.

    Science.gov (United States)

    Tao, Xue; Li, Aimin; Yang, Hu

    2017-03-01

    Three low-cost natural polymer materials, namely, lignin (Ln), carboxymethyl cellulose, and sodium alginate, were used for soil amendment to immobilize lead and cadmium in two contaminated soil samples collected from a mining area in Nanjing, China. The remediation effects of the aforementioned natural polymers were evaluated by toxicity characteristic leaching procedure (TCLP) and sequential extractions. The stabilizers could lower the bioavailability of Pb and Cd in the contaminated soils, and the amount of the exchangeable forms of the aforementioned two metals were reduced evidently. TCLP results showed that the leaching concentrations of Pb and Cd were decreased by 5.46%-71.1% and 4.25%-49.6%, respectively, in the treated soils. The contents of the organic forms of the two metals both increased with the increase in stabilizer dose on the basis of the redistribution of metal forms by sequential extractions. These findings were due to the fact that the abundant oxygen-containing groups on the polymeric amendments were effective in chelating and immobilizing Pb and Cd, which have been further confirmed from the metal adsorptions in aqueous solutions. Moreover, Ln achieved the greatest effect among the three polymers under study because of the former's distinct three-dimensional molecular structure, showing the preferential immobilization of Pb over Cd in soils also. Thus, the above-mentioned natural polymers hold great application potentials for reducing metal ion entry into the food chain at a field scale. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Phase transitions of rare earth compounds during immobilization by foamed corundum

    International Nuclear Information System (INIS)

    Potemkina, T.I.; Zakharov, M.A.; Plotnikova, T.E.

    1992-01-01

    Expansion of work on the environmentally safe handling of radioactive materials has become very important in recent years. The proposed method for immobilizing radionuclides by injection into a porous matrix and subsequent fixation has a definite advantage over other techniques, because of its simplicity and low cost. This raises a number of problems that require careful study. The authors can distinguish the following: choice of porous matrix materials; thermal decomposition of nitrates directly in the matrix itself, which determines the minimum firing temperature; behavior and properties of oxides produced in nitrate decomposition; conditions for compound formation between injected solutions and matrix material; processes occurring during immobilizer storage. The rare earth nitrate series can be divided into two groups on the basis of behavior during thermal decomposition: the elements preceding and following Gd. The first group includes La, Pr, And Eu, for which decomposition begins simultaneously with conclusion of dehydration; the second includes Dy, Tb, and Yb, for which nitrate group decomposition begins before dehydration is complete. The authors utilized DTA, XPA, and IR analysis to study the physicochemical properties of the immobilizer produced by a single impregnation of the foamed corundum with rare earth (La, Eu, Dy, Tb, and Yb) nitrate solutions and subsequent firing at 900 degrees C for 30 min. The choice of these rare earths was dictated by the fact that the Ln 2 O 3 -AlO 3 system can be divided into three groups on the basis of phase ratios: La-Nd, Sm-Eu, and Gd-Lu. Lanthanide monoaluminates are formed in all these groups, and the difference lies in the other reaction products generated: LnAl 11 O 18 for La-Nd, LnAl 11 O 18 and Ln 4 Al 2 O 9 for Sm-Eu, and Ln 4 Al 2 O 9 and Ln 3 Al 5 O 12 for Gd-Lu

  16. Bioremediation of Petrochemical Wastewater Containing BTEX Compounds by a New Immobilized Bacterium Comamonas sp. JB in Magnetic Gellan Gum.

    Science.gov (United States)

    Jiang, Bei; Zhou, Zunchun; Dong, Ying; Wang, Bai; Jiang, Jingwei; Guan, Xiaoyan; Gao, Shan; Yang, Aifu; Chen, Zhong; Sun, Hongjuan

    2015-05-01

    In this study, we investigated the bioremediation of petrochemical wastewater containing BTEX compounds by immobilized Comamonas sp. JB cells. Three kinds of magnetic nanoparticles were evaluated as immobilization supports for strain JB. After comparison with Fe3O4 and a-Fe2O3 nanoparticles, r-Fe2O3 nanoparticle was selected as the optimal immobilization support. The highest biodegradation activity of r-Fe2O3-magnetically immobilized cells was obtained when the concentration of r-Fe2O3 nanoparticle was 120 mg L(-1). Additionally, the recycling experiments demonstrated that the degradation activity of r-Fe2O3-magnetically immobilized cells was still high and led to less toxicity than untreated wastewater during the eight recycles. qPCR suggested the concentration of strain JB in r-Fe2O3-magnetically immobilized cells was evidently increased after eight cycles of degradation experiments. These results supported developing efficient biocatalysts using r-Fe2O3-magnetically immobilized cells and provided a promising technique for improving biocatalysts used in the bioremediation of not only petrochemical wastewater but also other hazardous wastewater.

  17. N-Confused Porphyrin Immobilized on Solid Supports: Synthesis and Metal Ions Sensing Efficacy

    Directory of Open Access Journals (Sweden)

    Sara R. D. Gamelas

    2018-04-01

    Full Text Available In this work, the N-confused porphyrin 5,10,15,20-tetraphenyl-2-aza-21-carbaporphyrin (NCTPP was immobilized on neutral or cationic supports based on silica and on Merrifield resin. The new materials were characterized by appropriate techniques (UV-Vis spectroscopy, SEM, and zeta potential analysis. Piezoelectric quartz crystal gold electrodes were coated with the different hybrids and their ability to interact with heavy metals was evaluated. The preliminary results obtained showed that the new materials can be explored for metal cations detection and the modification of the material surface is a key factor in tuning the metal selectivity.

  18. Preparation of metal-resistant immobilized sulfate reducing bacteria beads for acid mine drainage treatment.

    Science.gov (United States)

    Zhang, Mingliang; Wang, Haixia; Han, Xuemei

    2016-07-01

    Novel immobilized sulfate-reducing bacteria (SRB) beads were prepared for the treatment of synthetic acid mine drainage (AMD) containing high concentrations of Fe, Cu, Cd and Zn using up-flow anaerobic packed-bed bioreactor. The tolerance of immobilized SRB beads to heavy metals was significantly enhanced compared with that of suspended SRB. High removal efficiencies of sulfate (61-88%) and heavy metals (>99.9%) as well as slightly alkaline effluent pH (7.3-7.8) were achieved when the bioreactor was fed with acidic influent (pH 2.7) containing high concentrations of multiple metals (Fe 469 mg/L, Cu 88 mg/L, Cd 92 mg/L and Zn 128 mg/L), which showed that the bioreactor filled with immobilized SRB beads had tolerance to AMD containing high concentrations of heavy metals. Partially decomposed maize straw was a carbon source and stabilizing agent in the initial phase of bioreactor operation but later had to be supplemented by a soluble carbon source such as sodium lactate. The microbial community in the bioreactor was characterized by denaturing gradient gel electrophoresis (DGGE) and sequencing of partial 16S rDNA genes. Synergistic interaction between SRB (Desulfovibrio desulfuricans) and co-existing fermentative bacteria could be the key factor for the utilization of complex organic substrate (maize straw) as carbon and nutrients source for sulfate reduction. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Immobilization of transition metal ions on zirconium phosphate monolayers

    International Nuclear Information System (INIS)

    Melezhik, A.V.; Brej, V.V.

    1998-01-01

    It is shown that ions of transition metals (copper, iron, vanadyl, titanium) are adsorbed on zirconium phosphate monolayers. The zirconium phosphate threshold capacity corresponds to substitution of all protons of hydroxyphosphate groups by equivalent amounts of copper, iron or vanadyl. Adsorption of polynuclear ions is possible in case of titanium. The layered substance with specific surface up to 300 m 2 /g, wherein ultradispersed titanium dioxide particles are intercalirated between zirconium-phosphate layers, is synthesized

  20. Task-specific ionic liquids for solubilizing metal compounds

    OpenAIRE

    Thijs, Ben

    2007-01-01

    The main goal of this PhD thesis was to design new task-specific ionic liquids with the ability to dissolve metal compounds. Despite the large quantity of papers published on ionic liquids, not much is known about the mechanisms of dissolving metals in ionic liquids or about metal-containing ionic liquids. Additionally, many of the commercially available ionic liquids exhibit a very limited solubilizing power for metal compounds, although this is for many applications like electrodeposition a...

  1. Immobilization of metal wastes by reaction with H2S in anoxic basins: concept and elaboration.

    Science.gov (United States)

    Schuiling, R D

    2013-10-01

    Metal wastes are produced in large quantities by a number of industries. Their disposal in isolated waste deposits is certain to cause many subsequent problems, because every material will sooner or later return to the geochemical cycle. The sealing of disposal sites usually starts to leak, often within a short time after the disposal site has been filled. The contained heavy metals are leached from the waste deposit and will contaminate the soil and the groundwater. It is evident that storage as metal sulfides in a permanently anoxic environment is the only safe way to handle metal wastes. The world's largest anoxic basin, the Black Sea, can serve as a georeactor. The metal wastes are sustainably transformed into harmless and immobile solids. These are incorporated in the lifeless bottom muds, where they are stored for millions of years.

  2. Co-Immobilization of Enzymes and Magnetic Nanoparticles by Metal-Nucleotide Hydrogelnanofibers for Improving Stability and Recycling

    Directory of Open Access Journals (Sweden)

    Chunfang Li

    2017-01-01

    Full Text Available In this paper we report a facile method for preparing co-immobilized enzyme and magnetic nanoparticles (MNPs using metal coordinated hydrogel nanofibers. Candida rugosa lipase (CRL was selected as guest protein. For good aqueous dispersity, low price and other unique properties, citric acid-modified magnetic iron oxide nanoparticles (CA-Fe3O4 NPs have been widely used for immobilizing enzymes. As a result, the relative activity of CA-Fe3O4@Zn/AMP nanofiber-immobilized CRL increased by 8-fold at pH 10.0 and nearly 1-fold in a 50 °C water bath after 30 min, compared to free CRL. Moreover, the immobilized CRL had excellent long-term storage stability (nearly 80% releative activity after storage for 13 days. This work indicated that metal-nucleotide nanofibers could efficiently co-immobilize enzymes and MNPs simultaneously, and improve the stability of biocatalysts.

  3. Evaluation of ettringite and hydrocalumite formation for heavy metal immobilization: Literature review and experimental study

    International Nuclear Information System (INIS)

    Chrysochoou, Maria; Dermatas, Dimitris

    2006-01-01

    The immobilization of heavy metal oxyanions like chromate, arsenate and selenate, has proven to be a challenging task as they are highly mobile in alkaline environments involving S/S of contaminated media. Ettringite, a pozzolanic phase that forms in cementitious materials, has been proposed as a viable immobilization mechanism for oxyanions, wherein the oxyanion may substitute for sulfate in the ettringite structure. A literature review on the immobilization potential of ettringite showed that the substitution potential exists from the thermodynamic point of view where the formation of substituted ettringites occurs under strictly controlled conditions. The pH control over a narrow range is essential for ettringite stability; it becomes even narrower for substituted ettringites, as competing effects with sulfate ettringite and monophases are significantly affected by pH. The presence of sulfate has a catalytic effect on oxyanion incorporation in ettringite. Rapid leaching may occur when the treated media is exposed to sulfate influx. Conversely, monophases seem to be more suitable than ettringite for oxyanion immobilization, mainly as they control oxyanion solubility to lower levels than ettringite. A shift to the thermodynamic equilibrium caused by a shift in environmental conditions may result in monophase conversion to ettringite, which may lead to catastrophic expansion, as widely demonstrated in the cement and soils literature. Overall, the sensitivity of phase equilibria in cement-like systems involving oxyanions is significant with regard to multiple parameters and it is uncertain to what extent these can be predicted and/or controlled in the field

  4. Immobilization of heavy metals on pillared montmorillonite with a grafted chelate ligand.

    Science.gov (United States)

    Brown, Loren; Seaton, Kenneth; Mohseni, Ray; Vasiliev, Aleksey

    2013-10-15

    The objective of this work was the development of an efficient adsorbent for irreversible immobilization of heavy metals in contaminated soils. The adsorbent was prepared by pillaring of montmorillonite with silica followed by grafting of a chelate ligand on its surface. Obtained adsorbent was mesoporous with high content of adsorption sites. Its structure was studied by BET adsorption of N2, dynamic light scattering, and scanning electron microscopy. The adsorption capacity of the organoclay was measured by its mixing with contaminated kaolin and soil samples and by analysis of heavy metal contents in leachate. Deionized water and 50% acetic acid were used for leaching of metals from the samples. As it was demonstrated by the experiments, the adsorbent was efficient in immobilization of heavy metals not only in neutral aqueous media but also in the presence of weak acid. As a result, the adsorbent can be used for reduction of heavy metal leaching from contaminated sites. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Procion Green H-4G immobilized poly(hydroxyethylmethacrylate/chitosan) composite membranes for heavy metal removal

    International Nuclear Information System (INIS)

    Genc, Oe.; Soysal, L.; Bayramoglu, G.; Arica, M.Y.; Bektas, S.

    2003-01-01

    The effective removal of toxic heavy metals from environmental samples still remains a major topic of present research. Metal-chelating membranes are very promising materials as adsorbents when compared with conventional beads because they are not compressible, and they eliminate internal diffusion limitations. The purpose of this study was to evaluate the performance of a novel adsorbent, Procion Green H-4G immobilized poly(hydroxyethylmethacrylate (HEMA)/chitosan) composite membranes, for the removal of three toxic heavy metal ions, namely, Cd(II), Pb(II) and Hg(II) from aquatic systems. The Procion Green H-4G immobilized poly(hydroxyethylmethacrylate/chitosan) composite membranes were characterized by elemental analysis, scanning electron microscopy and Fourier transform infrared (FTIR) spectroscopy. The immobilized amount of the Procion Green H-4G was calculated as 0.018±0.003 μmol/cm 2 from the nitrogen and sulphur stoichiometry. The adsorption capacity of Procion Green H-4G immobilized poly(hydroxyethylmethacrylate/chitosan) composite membranes for selected heavy metal ions from aqueous media containing different amounts of these ions (30-400 mg/l) and at different pH values (2.0-6.0) was investigated. The amount of Cd(II), Pb(II) and Hg(II) adsorbed onto the membranes measured at equilibrium, increased with time during the first 45 min and then remained unchanged toward the equilibrium adsorption. The maximum amounts of heavy metal ions adsorbed were 43.60±1.74, 68.81±2.75 and 48.22±1.92 mg/g for Cd(II), Pb(II) and Hg(II), respectively. The heavy metal ion adsorption on the pHEMA/chitosan membranes (carrying no dye) were relatively low, 6.31±0.13 mg/g for Cd(II), 18.73±0.37 mg/g for Pb(II) and 18.82±0.38 mg/g for Hg(II). Competitive adsorption of the metal ions was also studied. When the metal ions competed with each other, the adsorbed amounts were 12.74±0.38 mg Cd(II)/g, 28.80±0.86 mg Pb(II)/g and 18.41±0.54 mg Hg(II)/g. Procion Green H-4G

  6. Immobilization of heavy metals arising sludge galvanic, in glass ceramic material

    International Nuclear Information System (INIS)

    Felisberto, R.; Santos, M.C.; Basegio, T.; Bergmann, C.P.

    2016-01-01

    The use of galvanic sludge in the glass-ceramic formulation for immobilizing environmentally harmful materials is consolidated in more developed countries as raw material in the formulation of new materials. In this work, we have used galvanic sludge provided by a metallurgical company located in Vale dos Sinos, RS. The sludge was dried at 105°C and mixed with soda-lime glass in proportions of 1, 5, 10 and 20%, relative to the glass mass. Its composition was determined by FRX, and evaluated for leaching (NBR 10005) and solubilization (NBR 10006). The specimens (CPs) were burned at temperatures 750, 800 and 850°C, also submitted to the tests. The sludge, Class I - dangerous, presented Se content greater than provisions of NBR 10004. It was possible to immobilize the heavy metals at a temperature of 850°C for specimens of the F1 formulation, having been thus classified as Class II B Inert Residue. (author)

  7. Applications of Immobilized Bio-Catalyst in Metal-Organic Frameworks

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2018-04-01

    Full Text Available Immobilization of bio-catalysts in solid porous materials has attracted much attention in the last few decades due to its vast application potential in ex vivo catalysis. Despite the high efficiency and selectivity of enzymatic catalytic processes, enzymes may suffer from denaturation under industrial production conditions, which, in turn, diminish their catalytic performances and long-term recyclability. Metal-organic frameworks (MOFs, as a growing type of hybrid materials, have been identified as promising platforms for enzyme immobilization owing to their enormous structural and functional tunability, and extraordinary porosity. This review mainly focuses on the applications of enzyme@MOFs hybrid materials in catalysis, sensing, and detection. The improvements of catalytic activity and robustness of encapsulated enzymes over the free counterpart are discussed in detail.

  8. Production of metals and compounds by radiation chemistry

    Science.gov (United States)

    Marsik, S. J.; Philipp, W. H.

    1969-01-01

    Preparation of metals and compounds by radiation induced chemical reactions involves irradiation of metal salt solutions with high energy electrons. This technique offers a method for the preparation of high purity metals with minimum contamination from the container material or the cover gas.

  9. Metal immobilization by sludge-derived biochar: roles of mineral oxides and carbonized organic compartment.

    Science.gov (United States)

    Zhang, Weihua; Huang, Xinchen; Jia, Yanming; Rees, Frederic; Tsang, Daniel C W; Qiu, Rongliang; Wang, Hong

    2017-04-01

    Pyrolyzing sludge into biochar is a potentially promising recycling/disposal solution for municipal wastewater sludge, and the sludge-derived biochar (SDBC) presents an excellent sorbent for metal immobilization. As SDBC is composed of both mineral oxides and carbonized organic compartment, this study therefore compared the sorption behaviour of Pb and Zn on SDBC to those of individual and mixture of activated carbon (AC) and amorphous aluminium oxide (Al 2 O 3 ). Batch experiments were conducted at 25 and 45 °C, and the metal-loaded sorbents were artificially aged in the atmosphere for 1-60 days followed by additional sorption experiments. The Pb sorption was generally higher than Zn sorption, and the co-presence of Pb reduced Zn sorption on each studied sorbent. Higher sorption capacities were observed at 45 °C than 25 °C for SDBC and AC, while the opposite was shown for Al 2 O 3 , indicating the significance of temperature-dependent diffusion processes in SDBC and AC. Nevertheless, metal sorption was more selective on Al 2 O 3 that showed a greater affinity towards Pb over Zn under competition, correlating with the reducible fraction of sequential extraction. Furthermore, significant amounts of Pb and Zn were additionally sorbed on SDBC following 30-day ageing. The X-ray diffraction revealed the formation of metal-phosphate precipitates, while the X-ray photoelectron spectroscopy showed a larger quantity of metal-oxygen bonding after 30-day ageing of metal-loaded SDBC. The results may imply favourable long-term transformation and additional sorption capacity of SDBC. In conclusion, SDBC resembles the sorption characteristics of both organic and mineral sorbents in different aspects, presenting an appropriate material for metal immobilization during soil amendment.

  10. Radiation-induced crosslinking of polymeric micelles as nanoparticle for immobilization of bioactive compound

    International Nuclear Information System (INIS)

    Rida Tajau; Khairul Zaman Mohd Dahlan; Mohd Hilmi Mahmood; Wan Md Zin Wan Yunus; Kamaruddin Hashim; Nor Azowa Ibrahim; Maznah Ismail; Mek Zah Salleh

    2012-01-01

    The purpose of this study was to develop the bioactive-loaded polymeric nanoparticle by radiation-induced crosslinking technique. The polymeric micelles consist of acrylated palm oil (APO), anionic surfactant and aqueous solution was prepared for immobilization of bioactive compound for example the Thymoquinone (TQ). The TQ-loaded APO micelle was subjected to ionizing radiation to induce crosslinked polymeric structure of the TQ-loaded APO nanoparticle. The formation of TQ-loaded APO micro micelle and nano particle were evaluated by the Dynamic Light Scattering (DLS), the Fourier Transform Infrared (FTIR) Spectroscopy and the Transmission Electron Microscopy (TEM) for characterization the size, the shape, the chemical structure and the irradiation effect of the micelle and the nano particle. The results indicate that the size of APO micro and nano particles varies from 120 to 270 nanometer (nm) upon gamma irradiation at doses ranging from 1 to 25 kilo gray (kGy). In addition, size of the particle was found decreasing upon irradiation due to the crosslinking interaction. The study demonstrated that the APO micro-and nanoparticle can retained and controlled the release rate of the thymoquinone at up to 24 hours as determined using ultraviolet-visible (UV-Vis) spectrophotometer. These findings suggested that the ionizing radiation method can be utilized to prepare nano-size APO particles, with the presence of TQ. (author)

  11. Geopolymers with a high percentage of bottom ash for solidification/immobilization of different toxic metals

    Energy Technology Data Exchange (ETDEWEB)

    Boca Santa, Rozineide A. Antunes, E-mail: roosebs@gmail.com; Soares, Cíntia; Riella, Humberto Gracher

    2016-11-15

    Highlights: • Geopolymers from bottom ash and metakaolin (BA/M). • Solidification/immobilization (S/I) waste of heavy metals. • Activators: Sodium hydroxide (NaOH), potassium hydroxide (KOH) and sodium silicate (Na{sub 2}SiO{sub 3}). - Abstract: Geopolymers are produced using alkali-activated aluminosilicates, either as waste or natural material obtained from various sources. This study synthesized geopolymers from bottom ash and metakaolin (BA/M) in a 2:1 wt ratio to test the solidification/immobilization (S/I) properties of heavy metals in geopolymer matrices, since there is very little research using BA in this type of matrices. Therefore, a decision was made to use more than 65% of BA in geopolymer synthesis with and without the addition of heavy metals. The S/I tests with metals used 10, 15 and 30 ml of a waste solution after pickling of printed circuit boards containing metals, including Pb, Cr, Cu, Fe, Sn, As and Ni, in different proportions. As alkali activator, the NaOH and KOH were used in the concentrations of 8 and 12 M in the composition of Na{sub 2}SiO{sub 3} in 1:2 vol ratios. To test S/I efficiency, tests were conducted to obtain the leached and solubilized extract. The analysis was carried out through X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Scanning Electron Microscope (SEM), Energy-Dispersive X-Ray Spectroscopy (EDS) and compressive strength tests. The geopolymer showed a high degree of S/I of the metals; in some samples, the results reached nearly 100%.

  12. Geopolymers with a high percentage of bottom ash for solidification/immobilization of different toxic metals

    International Nuclear Information System (INIS)

    Boca Santa, Rozineide A. Antunes; Soares, Cíntia; Riella, Humberto Gracher

    2016-01-01

    Highlights: • Geopolymers from bottom ash and metakaolin (BA/M). • Solidification/immobilization (S/I) waste of heavy metals. • Activators: Sodium hydroxide (NaOH), potassium hydroxide (KOH) and sodium silicate (Na 2 SiO 3 ). - Abstract: Geopolymers are produced using alkali-activated aluminosilicates, either as waste or natural material obtained from various sources. This study synthesized geopolymers from bottom ash and metakaolin (BA/M) in a 2:1 wt ratio to test the solidification/immobilization (S/I) properties of heavy metals in geopolymer matrices, since there is very little research using BA in this type of matrices. Therefore, a decision was made to use more than 65% of BA in geopolymer synthesis with and without the addition of heavy metals. The S/I tests with metals used 10, 15 and 30 ml of a waste solution after pickling of printed circuit boards containing metals, including Pb, Cr, Cu, Fe, Sn, As and Ni, in different proportions. As alkali activator, the NaOH and KOH were used in the concentrations of 8 and 12 M in the composition of Na 2 SiO 3 in 1:2 vol ratios. To test S/I efficiency, tests were conducted to obtain the leached and solubilized extract. The analysis was carried out through X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Scanning Electron Microscope (SEM), Energy-Dispersive X-Ray Spectroscopy (EDS) and compressive strength tests. The geopolymer showed a high degree of S/I of the metals; in some samples, the results reached nearly 100%.

  13. TOXIC METALS IN THE ENVIRONMENT: THERMODYNAMIC CONSIDERATIONS FOR POSSIBLE IMMOBILIZATION STRATEGIES FOR PB, CD, AS, AND HG

    Science.gov (United States)

    The contamination of soils by toxic metals is a widespread, serious problem that demands immediate action either by removal or immobilization, which is defined as a process which puts the metal into a chemical form, probably as a mineral, which will be inert and highly insoluble ...

  14. Metal organic frameworks for removal of compounds from a fluid

    KAUST Repository

    Eddaoudi, Mohamed

    2016-03-03

    Embodiments provide a method of compound removal from a fluid. The method includes contacting one or more metal organic framework (MOF) compositions with a fluid and sorbing one or more compounds, such as CO2, H2S and condensable hydrocarbons. One or more of CO2, H2S and condensable hydrocarbons can be sorbed simultaneously or in series. The metal organic framework can be an M-soc-MOF.

  15. Metal organic frameworks for removal of compounds from a fluid

    KAUST Repository

    Eddaoudi, Mohamed; Belmabkhout, Youssef

    2016-01-01

    Embodiments provide a method of compound removal from a fluid. The method includes contacting one or more metal organic framework (MOF) compositions with a fluid and sorbing one or more compounds, such as CO2, H2S and condensable hydrocarbons. One or more of CO2, H2S and condensable hydrocarbons can be sorbed simultaneously or in series. The metal organic framework can be an M-soc-MOF.

  16. Enhanced Electrochemical Hydrogen Storage Performance on the Porous Graphene Network Immobilizing Cobalt Metal Nanoparticle

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Myunggoo; Lee, Dong Heon; Jung, Hyun [Dongguk University, Seoul (Korea, Republic of)

    2016-05-15

    In this study, we attempted to apply Co metal nanoparticles decorated on the surface of the porous graphene (Co-PG) as the electrochemical hydrogen storage system. Co-PG was successfully synthesized by the soft-template method. To determine the synthetic strategy of porous graphene and Co nanoparticles, we compare the obtained Co-PG with two different materials such as Co nanoparticle decorated reduced graphene oxide without soft-template (Co-RGO) and porous graphene without Co nanoparticle (PG). The experimental details regarding the synthesis and characterization of the Co-PG, Co-RGO, and PG samples are provided in Supporting Information. Co-PG with interpenetrating porous networks and immobilized Co metal nanoparticles were successfully synthesized by the soft-template method. The obtained Co-PG exhibited high-surface area with ink-bottle open pores owing to the homogeneous dispersion of P123 micellar rods. The XRD and FE-SEM analyses clearly confirm that Co nanoparticles were immobilized on to the surface of porous graphene without any significant aggregation. The as-obtained Co-PG showed good electrochemical performance such as capacity and cycle stability for hydrogen storage. Based on these results, we believe that the Co-PG with a high-specific surface area could be worthwhile to investigate as not only electrochemical hydrogen storage materials but also other energy storage applications.

  17. Enhanced Electrochemical Hydrogen Storage Performance on the Porous Graphene Network Immobilizing Cobalt Metal Nanoparticle

    International Nuclear Information System (INIS)

    Kang, Myunggoo; Lee, Dong Heon; Jung, Hyun

    2016-01-01

    In this study, we attempted to apply Co metal nanoparticles decorated on the surface of the porous graphene (Co-PG) as the electrochemical hydrogen storage system. Co-PG was successfully synthesized by the soft-template method. To determine the synthetic strategy of porous graphene and Co nanoparticles, we compare the obtained Co-PG with two different materials such as Co nanoparticle decorated reduced graphene oxide without soft-template (Co-RGO) and porous graphene without Co nanoparticle (PG). The experimental details regarding the synthesis and characterization of the Co-PG, Co-RGO, and PG samples are provided in Supporting Information. Co-PG with interpenetrating porous networks and immobilized Co metal nanoparticles were successfully synthesized by the soft-template method. The obtained Co-PG exhibited high-surface area with ink-bottle open pores owing to the homogeneous dispersion of P123 micellar rods. The XRD and FE-SEM analyses clearly confirm that Co nanoparticles were immobilized on to the surface of porous graphene without any significant aggregation. The as-obtained Co-PG showed good electrochemical performance such as capacity and cycle stability for hydrogen storage. Based on these results, we believe that the Co-PG with a high-specific surface area could be worthwhile to investigate as not only electrochemical hydrogen storage materials but also other energy storage applications

  18. Superconductivity of ternary metal compounds prepared at high pressures

    CERN Document Server

    Shirotani, I

    2003-01-01

    Various ternary metal phosphides, arsenides, antimonides, silicides and germanides have been prepared at high temperatures and high pressures. These ternary metal compounds can be classified into four groups: [1] metal-rich compounds MM' sub 4 X sub 2 and [2] MM'X, [3] non-metal-rich compounds MXX' and [4] MM' sub 4 X sub 1 sub 2 (M and M' = metal element; X and X' = non-metal element). We have studied the electrical and magnetic properties of these materials at low temperatures, and found many new superconductors with the superconducting transition temperature (T sub c) of above 10 K. The metal-rich compound ZrRu sub 4 P sub 2 with a tetragonal structure showed the superconducting transition at around 11 K, and had an upper critical field (H sub c sub 2) of 12.2 tesla (T) at 0 K. Ternary equiatomic compounds ZrRuP and ZrRuSi crystallize in two modifications, a hexagonal Fe sub 2 P-type structure [h-ZrRuP(Si)] and an orthorhombic Co sub 2 P-type structure [o-ZrRuP(Si)]. Both h-ZrRuP and h-ZrRuSi have rather h...

  19. Protein selectivity with immobilized metal ion-tacn sorbents: chromatographic studies with human serum proteins and several other globular proteins.

    Science.gov (United States)

    Jiang, W; Graham, B; Spiccia, L; Hearn, M T

    1998-01-01

    The chromatographic selectivity of the immobilized chelate system, 1,4,7-triazocyclononane (tacn), complexed with the borderline metal ions Cu2+, Cr3+, Mn2+, Co2+, Zn2+, and Ni2+ has been investigated with hen egg white lysozyme, horse heart cytochrome c, and horse skeletal muscle myoglobin, as well as proteins present in partially fractionated preparations of human plasma. The effects of ionic strength and pH of the loading and elution buffers on protein selectivities of these new immobilized metal ion affinity chromatographic (IMAC) systems have been examined. The results confirm that immobilized Mn;pl-tacn sorbents exhibit a novel type of IMAC behavior with proteins. In particular, the chromatographic properties of these immobilized M(n+)-tacn ligand systems were significantly different compared to the IMAC behavior observed with other types of immobilized tri- and tetradentate chelating ligands, such as iminodiacetic acid, O-phosphoserine, or nitrilotriacetic acid, when complexed with borderline metal ions. The experimental results have consequently been evaluated in terms of the additional contributions to the interactive processes mediated by effects other than solely the conventional lone pair Lewis soft acid-Lewis soft base coordination interactions, typically found for the IMAC of proteins with borderline and soft metal ions, such as Cu2+ or Ni2+.

  20. Heavy metal immobilization in soil near abandoned mines using eggshell waste and rapeseed residue.

    Science.gov (United States)

    Lee, Sang Soo; Lim, Jung Eun; El-Azeem, Samy A M Abd; Choi, Bongsu; Oh, Sang-Eun; Moon, Deok Hyun; Ok, Yong Sik

    2013-03-01

    Heavy metal contamination of agricultural soils has received great concern due to potential risk to human health. Cadmium and Pb are largely released from abandoned or closed mines in Korea, resulting in soil contamination. The objective of this study was to evaluate the effects of eggshell waste in combination with the conventional nitrogen, phosphorous, and potassium fertilizer (also known as NPK fertilizer) or the rapeseed residue on immobilization of Cd and Pb in the rice paddy soil. Cadmium and Pb extractabilities were tested using two methods of (1) the toxicity characteristics leaching procedure (TCLP) and (2) the 0.1 M HCl extraction. With 5 % eggshell addition, the values of soil pH were increased from 6.33 and 6.51 to 8.15 and 8.04 in combination with NPK fertilizer and rapeseed residue, respectively, compared to no eggshell addition. The increase in soil pH may contribute to heavy metal immobilization by altering heavy metals into more stable in soils. Concentrations of TCLP-extracted Cd and Pb were reduced by up to 67.9 and 93.2 % by addition of 5 % eggshell compared to control. For 0.1 M HCl extraction method, the concentration of 0.1 M HCl-Cd in soils treated with NPK fertilizer and rapeseed residue was significantly reduced by up to 34.01 and 46.1 %, respectively, with 5 % eggshell addition compared to control. A decrease in acid phosphatase activity and an increase in alkaline phosphatase activity at high soil pH were also observed. Combined application of eggshell waste and rapeseed residue can be cost-effective and beneficial way to remediate the soil contaminated with heavy metals.

  1. Metal complex catalysis in the synthesis of organoaluminium compounds

    International Nuclear Information System (INIS)

    Dzhemilev, Usein M; Ibragimov, Askhat G

    2000-01-01

    The published data on the synthesis of organoaluminium compounds involving metal complex catalysts are generalised and systematised. Hydro-, carbo- and cycloalumination reactions of alkenes, conjugated dienes and alkynes catalysed by Ti and Zr complexes are considered in detail. The use of organoaluminium reagents in organic synthesis and novel reactions involving these compounds are discussed. The bibliography includes 240 references.

  2. Geopolymers with a high percentage of bottom ash for solidification/immobilization of different toxic metals.

    Science.gov (United States)

    Boca Santa, Rozineide A Antunes; Soares, Cíntia; Riella, Humberto Gracher

    2016-11-15

    Geopolymers are produced using alkali-activated aluminosilicates, either as waste or natural material obtained from various sources. This study synthesized geopolymers from bottom ash and metakaolin (BA/M) in a 2:1wt ratio to test the solidification/immobilization (S/I) properties of heavy metals in geopolymer matrices, since there is very little research using BA in this type of matrices. Therefore, a decision was made to use more than 65% of BA in geopolymer synthesis with and without the addition of heavy metals. The S/I tests with metals used 10, 15 and 30ml of a waste solution after pickling of printed circuit boards containing metals, including Pb, Cr, Cu, Fe, Sn, As and Ni, in different proportions. As alkali activator, the NaOH and KOH were used in the concentrations of 8 and 12M in the composition of Na2SiO3 in 1:2vol ratios. To test S/I efficiency, tests were conducted to obtain the leached and solubilized extract. The analysis was carried out through X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Scanning Electron Microscope (SEM), Energy-Dispersive X-Ray Spectroscopy (EDS) and compressive strength tests. The geopolymer showed a high degree of S/I of the metals; in some samples, the results reached nearly 100%. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Supply and cost factors for metals in the Canadian nuclear fuel waste immobilization program

    International Nuclear Information System (INIS)

    McConnell, D.B.

    1982-11-01

    Estimates have been made of the demand for immobilization containers to accommodate the irradiated fuel bundles arising from Canadian nuclear generating stations to the year 2020. The resulting estimates for container shells and container-filling alloys were compared to estimates for Canadian and Western World production of the candiate metals. The results indicate that, among the container shell metals, supply difficulties might arise only for Grade 7 titanium. Among the filling metals, only lead-antimony alloy might present supply problems. Current cost figures for plate made of each shell metal, and bulk quantities of filling metals, were compared. Materials costs would be least for a supported shell of stainless steel, followed by copper, titanium alloys Grades 2, 12 and 7, and Inconel 625. Aluminum-silicon is the lowest-cost filling matrix, followed by zinc, lead, and lead-antimony. Container durability, vault conditions, groundwater composition and other factors may play an overriding role in the final selection of materials for container construction

  4. [Exposure to metal compounds in occupational galvanic processes].

    Science.gov (United States)

    Surgiewicz, Jolanta; Domański, Wojciech

    2006-01-01

    Occupational galvanic processes are provided in more than 600 small and medium enterprises in Poland. Workers who deal with galvanic coating are exposed to heavy metal compounds: tin, silver, copper and zinc. Some of them are carcinogenic, for example, hexavalent chromium compounds, nickel and cadmium compounds. Research covered several tens of workstations involved in chrome, nickel, zinc, tin, silver, copper and cadmium plating. Compounds of metals present in the air were determined: Cr, Ni, Cd, Sn, Ag--by atomic absorption spectrometry with electrothermal atomization (ET-AAS) and Zn--by atomic absorption spectrometry with flame atomization (F-AAS). The biggest metal concentrations--of silver and copper--were found at workstations of copper, brass, cadmium, nickel and chrome plating, conducted at the same time. Significant concentrations of copper were found at workstations of maintenance bathing and neutralizing of sewage. The concentrations of metals did not exceed Polish MAC values. MAC values were not exceeded for carcinogenic chromium(VI), nickel or cadmium, either. In galvanic processes there was no hazard related to single metals or their compounds, even carcinogenic ones. Combined exposure indicators for metals at each workstation did not exceed 1, either. However, if there are even small quantities of carcinogenic agents, health results should always be taken into consideration.

  5. Metal cluster compounds - chemistry and importance; clusters containing isolated main group element atoms, large metal cluster compounds, cluster fluxionality

    International Nuclear Information System (INIS)

    Walther, B.

    1988-01-01

    This part of the review on metal cluster compounds deals with clusters containing isolated main group element atoms, with high nuclearity clusters and metal cluster fluxionality. It will be obvious that main group element atoms strongly influence the geometry, stability and reactivity of the clusters. High nuclearity clusters are of interest in there own due to the diversity of the structures adopted, but their intermediate position between molecules and the metallic state makes them a fascinating research object too. These both sites of the metal cluster chemistry as well as the frequently observed ligand and core fluxionality are related to the cluster metal and surface analogy. (author)

  6. Biologically active compounds of semi-metals

    Czech Academy of Sciences Publication Activity Database

    Řezanka, Tomáš; Sigler, Karel

    2008-01-01

    Roč. 69, č. 3 (2008), s. 585-606 ISSN 0031-9422 Institutional research plan: CEZ:AV0Z50200510 Keywords : semi-metals * boron * silicon Subject RIV: CE - Biochemistry Impact factor: 2.946, year: 2008

  7. Polymer-immobilized ready-to-use recombinant yeast assays for the detection of endocrine disruptive compounds.

    Science.gov (United States)

    Bittner, Michal; Jarque, Sergio; Hilscherová, Klára

    2015-08-01

    Recombinant yeast assays (RYAs) constitute a suitable tool for the environmental monitoring of compounds with endocrine disrupting activities, notably estrogenicity and androgenicity. Conventional procedures require yeast reconstitution from frozen stock, which usually takes several days and demands additional equipment. With the aim of applying such assays to field studies and making them more accessible to less well-equipped laboratories, we have optimized RYA by the immobilization of Saccharomyces cerevisiae cells in three different polymer matrices - gelatin, Bacto agar, and Yeast Extract Peptone Dextrose agar - to obtain a ready-to-use version for the fast assessment of estrogenic and androgenic potencies of compounds and environmental samples. Among the three matrices, gelatin showed the best results for both testosterone (androgen receptor yeast strain; AR-RYA) and 17β-estradiol (estrogen receptor yeast strain; ER-RYA). AR-RYA was characterized by a lowest observed effect concentration (LOEC), EC50 and induction factor (IF) of 1nM, 2.2nM and 51, respectively. The values characterizing ER-RYA were 0.4nM, 1.8nM, and 63, respectively. Gelatin immobilization retained yeast viability and sensitivity for more than 90d of storage at 4°C. The use of the immobilized yeast reduced the assay duration to only 3h without necessity of sterile conditions. Because immobilized RYA can be performed either in multiwell microplates or glass tubes, it allows multiple samples to be tested at once, and easy adaptation to existing portable devices for direct in-field applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Biochar immobilizes soil-borne arsenic but not cationic metals in the presence of low-molecular-weight organic acids.

    Science.gov (United States)

    Alozie, Nneka; Heaney, Natalie; Lin, Chuxia

    2018-07-15

    A batch experiment was conducted to examine the effects of biochar on the behaviour of soil-borne arsenic and metals that were mobilized by three low-molecular-weight organic acids. In the presence of citric acid, oxalic acid and malic acid at a molar concentration of 0.01M, the surface of biochar was protonated, which disfavours adsorption of the cationic metals released from the soil by organic acid-driven mobilization. In contrast, the oxyanionic As species were re-immobilized by the protonated biochar effectively. Biochar could also immobilize oxyanionic Cr species but not cationic Cr species. The addition of biochar increased the level of metals in the solution due to the release of the biochar-borne metals under attack by LMWOAs via cation exchange. Biochar could also have the potential to enhance reductive dissolution of iron and manganese oxides in the soil, leading to enhanced release of trace elements bound to these oxides. The findings obtained from this study have implications for evaluating the role of biochar in immobilizing trace elements in rhizosphere. Adsorption of cationic heavy metals on biochar in the presence of LMWOAs is unlikely to be a mechanism responsible for the impeded uptake of heavy metals by plants growing in heavy metal-contaminated soils. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Remediation of multiple heavy metal-contaminated soil through the combination of soil washing and in situ immobilization.

    Science.gov (United States)

    Zhai, Xiuqing; Li, Zhongwu; Huang, Bin; Luo, Ninglin; Huang, Mei; Zhang, Qiu; Zeng, Guangming

    2018-09-01

    The remediation of heavy metal-contaminated soils is a great challenge for global environmental sciences and engineering. To control the ecological risks of heavy metal-contaminated soil more effectively, the present study focused on the combination of soil washing (with FeCl 3 ) and in situ immobilization (with lime, biochar, and black carbon). The results showed that the removal rate of Cd, Pb, Zn, and Cu was 62.9%, 52.1%, 30.0%, and 16.7%, respectively, when washed with FeCl 3 . After the combined remediation (immobilization with 1% (w/w) lime), the contaminated soils showed 36.5%, 73.6%, 70.9%, and 53.4% reductions in the bioavailability of Cd, Cu, Pb, and Zn (extracted with 0.11M acetic acid), respectively, than those of the soils washed with FeCl 3 only. However, the immobilization with 1% (w/w) biochar or 1% (w/w) carbon black after washing exhibited low effects on stabilizing the metals. The differences in effects between the immobilization with lime, biochar, and carbon black indicated that the soil pH had a significant influence on the lability of heavy metals during the combined remediation process. The activity of the soil enzymes (urease, sucrase, and catalase) showed that the addition of all the materials, including lime, biochar, and carbon black, exhibited positive effects on microbial remediation after soil washing. Furthermore, lime was the most effective material, indicating that low soil pH and high acid-soluble metal concentrations might restrain the activity of soil enzymes. Soil pH and nutrition were the major considerations for microbial remediation during the combined remediation. These findings suggest that the combination of soil washing and in situ immobilization is an effective method to amend the soils contaminated with multiple heavy metals. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Utilization of a Novel Chitosan/Clay/Biochar Nanobiocomposite for Immobilization of Heavy Metals in Acid Soil Environment

    NARCIS (Netherlands)

    Arabyarmohammadi, Hoda; Darban, Ahmad Khodadadi; Abdollahy, Mahmoud; Yong, Raymond; Ayati, Bita; Zirakjou, Abbas; Zee, van der Sjoerd E.A.T.M.

    2018-01-01

    An organic–inorganic composite of chitosan, nanoclay, and biochar (named as MTCB) was chosen to develop a bionanocomposite to simultaneously immobilize Cu, Pb, and Zn metal ions within the contaminated soil and water environments. The composite material was structurally and chemically characterized

  11. Immobilized metal-affinity chromatography protein-recovery screening is predictive of crystallographic structure success

    International Nuclear Information System (INIS)

    Choi, Ryan; Kelley, Angela; Leibly, David; Nakazawa Hewitt, Stephen; Napuli, Alberto; Van Voorhis, Wesley

    2011-01-01

    An overview of the methods used for high-throughput cloning and protein-expression screening of SSGCID hexahistidine recombinant proteins is provided. It is demonstrated that screening for recombinant proteins that are highly recoverable from immobilized metal-affinity chromatography improves the likelihood that a protein will produce a structure. The recombinant expression of soluble proteins in Escherichia coli continues to be a major bottleneck in structural genomics. The establishment of reliable protocols for the performance of small-scale expression and solubility testing is an essential component of structural genomic pipelines. The SSGCID Protein Production Group at the University of Washington (UW-PPG) has developed a high-throughput screening (HTS) protocol for the measurement of protein recovery from immobilized metal-affinity chromatography (IMAC) which predicts successful purification of hexahistidine-tagged proteins. The protocol is based on manual transfer of samples using multichannel pipettors and 96-well plates and does not depend on the use of robotic platforms. This protocol has been applied to evaluate the expression and solubility of more than 4000 proteins expressed in E. coli. The UW-PPG also screens large-scale preparations for recovery from IMAC prior to purification. Analysis of these results show that our low-cost non-automated approach is a reliable method for the HTS demands typical of large structural genomic projects. This paper provides a detailed description of these protocols and statistical analysis of the SSGCID screening results. The results demonstrate that screening for proteins that yield high recovery after IMAC, both after small-scale and large-scale expression, improves the selection of proteins that can be successfully purified and will yield a crystal structure

  12. Thin films of metal-organic compounds and metal nanoparticle ...

    Indian Academy of Sciences (India)

    Optical limiting capability of the nanoparticle-embedded polymer film is demonstrated. Keywords. Polar crystal; uniaxial orientational order; thin film; second harmonic gen- eration; silver ... able content of metal nanoparticles would be of considerable value from an appli- ... polar chain and perpendicular to it [10].

  13. Development of a Novel Optical Biosensor for Detection of Organophoshorus Pesticides Based on Methyl Parathion Hydrolase Immobilized by Metal-Chelate Affinity

    Directory of Open Access Journals (Sweden)

    Wensheng Lan

    2012-06-01

    Full Text Available We have developed a novel optical biosensor device using recombinant methyl parathion hydrolase (MPH enzyme immobilized on agarose by metal-chelate affinity to detect organophosphorus (OP compounds with a nitrophenyl group. The biosensor principle is based on the optical measurement of the product of OP catalysis by MPH (p-nitrophenol. Briefly, MPH containing six sequential histidines (6× His tag at its N-terminal was bound to nitrilotriacetic acid (NTA agarose with Ni ions, resulting in the flexible immobilization of the bio-reaction platform. The optical biosensing system consisted of two light-emitting diodes (LEDs and one photodiode. The LED that emitted light at the wavelength of the maximum absorption for p-nitrophenol served as the signal light, while the other LED that showed no absorbance served as the reference light. The optical sensing system detected absorbance that was linearly correlated to methyl parathion (MP concentration and the detection limit was estimated to be 4 μM. Sensor hysteresis was investigated and the results showed that at lower concentration range of MP the difference got from the opposite process curves was very small. With its easy immobilization of enzymes and simple design in structure, the system has the potential for development into a practical portable detector for field applications.

  14. Development of a Novel Optical Biosensor for Detection of Organophoshorus Pesticides Based on Methyl Parathion Hydrolase Immobilized by Metal-Chelate Affinity

    Science.gov (United States)

    Lan, Wensheng; Chen, Guoping; Cui, Feng; Tan, Feng; Liu, Ran; Yushupujiang, Maolidan

    2012-01-01

    We have developed a novel optical biosensor device using recombinant methyl parathion hydrolase (MPH) enzyme immobilized on agarose by metal-chelate affinity to detect organophosphorus (OP) compounds with a nitrophenyl group. The biosensor principle is based on the optical measurement of the product of OP catalysis by MPH (p-nitrophenol). Briefly, MPH containing six sequential histidines (6× His tag) at its N-terminal was bound to nitrilotriacetic acid (NTA) agarose with Ni ions, resulting in the flexible immobilization of the bio-reaction platform. The optical biosensing system consisted of two light-emitting diodes (LEDs) and one photodiode. The LED that emitted light at the wavelength of the maximum absorption for p-nitrophenol served as the signal light, while the other LED that showed no absorbance served as the reference light. The optical sensing system detected absorbance that was linearly correlated to methyl parathion (MP) concentration and the detection limit was estimated to be 4 μM. Sensor hysteresis was investigated and the results showed that at lower concentration range of MP the difference got from the opposite process curves was very small. With its easy immobilization of enzymes and simple design in structure, the system has the potential for development into a practical portable detector for field applications. PMID:23012501

  15. Crystal field in rare-earth metals and intermetallic compounds

    International Nuclear Information System (INIS)

    Ray, D.K.

    1978-01-01

    Reasons for the success of the crystal-field model for the rare-earth metals and intermetallic compounds are discussed. A review of some of the available experimental results is made with emphasis on cubic intermetallic compounds. Various sources of the origin of the crystal field in these metals are discussed in the background of the recent APW picture of the conduction electrons. The importance of the non-spherical part of the muffin-tin potential on the single-ion anisotropy is stressed. (author)

  16. Organometallic compounds of the lanthanides, actinides and early transition metals

    Energy Technology Data Exchange (ETDEWEB)

    Cardin, D J [Trinity Coll., Dublin (Ireland); Cotton, S A [Stanground School, Peterborough (UK); Green, M [Bristol Univ. (UK); Labinger, J A [Atlantic Richfield Co., Los Angeles, CA (USA); eds.

    1985-01-01

    This book provides a reference compilation of physical and biographical data on over 1500 of the most important and useful organometallic compounds of the lanthanides, actinides and early transition metals representing 38 different elements. The compounds are listed in molecular formula order in a series of entries in dictionary format. Details of structure, physical and chemical properties, reactions and key references are clearly set out. All the data is fully indexed and a structural index is provided.

  17. Process for removing heavy metal compounds from heavy crude oil

    Science.gov (United States)

    Cha, Chang Y.; Boysen, John E.; Branthaver, Jan F.

    1991-01-01

    A process is provided for removing heavy metal compounds from heavy crude oil by mixing the heavy crude oil with tar sand; preheating the mixture to a temperature of about 650.degree. F.; heating said mixture to up to 800.degree. F.; and separating tar sand from the light oils formed during said heating. The heavy metals removed from the heavy oils can be recovered from the spent sand for other uses.

  18. Competitive immobilization of Pb in an aqueous ternary-metals system by soluble phosphates with varying pH.

    Science.gov (United States)

    Zhang, Zhuo; Ren, Jie; Wang, Mei; Song, Xinlai; Zhang, Chao; Chen, Jiayu; Li, Fasheng; Guo, Guanlin

    2016-09-01

    Chemical immobilization by phosphates has been widely and successfully applied to treat Pb in wastewater and contaminated soils. Pb in wastewaters and soils, however, always coexists with other heavy metals and their competitive reactions with phosphates have not been quantitatively and systematically studied. In this approach, immobilization of Pb, Zn, and Cd by mono-, di-, and tripotassium phosphate (KH2PO4, K2HPO4, and K3PO4) was observed in the single- and ternary-metals solutions. The immobilization rates of the three metals were determined by the residual concentration. The mineral composition and structure of the precipitates were characterized by powder X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM). The results indicated that competitive reaction occurred in Pb-Zn-Cd ternary system, with immobilization rates decrease of system. The reaction of Pb with three phosphates exhibited intense competitiveness and the phosphates had a stronger affinity for Pb when Cl(-) was added. Pb-phosphate minerals formed by KH2PO4 with the better crystalline characteristics and largest size were very stable with a low dissolution rate (system. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Raman scattering in transition metal compounds: Titanium and compounds of titanium

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, J.; Ederer, D.L.; Shu, T. [Tulane Univ., New Orleans, LA (United States)] [and others

    1997-04-01

    The transition metal compounds form a very interesting and important set of materials. The diversity arises from the many states of ionization the transition elements may take when forming compounds. This variety provides ample opportunity for a large class of materials to have a vast range of electronic and magnetic properties. The x-ray spectroscopy of the transition elements is especially interesting because they have unfilled d bands that are at the bottom of the conduction band with atomic like structure. This group embarked on the systematic study of transition metal sulfides and oxides. As an example of the type of spectra observed in some of these compounds they have chosen to showcase the L{sub II, III} emission and Raman scattering in some titanium compounds obtained by photon excitation.

  20. Effect of some metal-containing compounds and fertilizers on ...

    African Journals Online (AJOL)

    USER

    2010-06-28

    Jun 28, 2010 ... grown on potato dextrose agar (PDA, BDH Ltd, UK 39 g/l) medium, maintained on PDA medium and stored at 4°C for further use. In this experiment, the mycelia growth capability of the Trichoderma isolates against some metal-containing compounds and fertilizers, consist of MgSO4.7H2O (containing ...

  1. Proficiency test for heavy metals in compound feed

    NARCIS (Netherlands)

    Pereboom, D.P.K.H.; Elbers, I.J.W.; Jong, de J.; Lee, van der M.K.; Nijs, de W.C.M.

    2016-01-01

    The here described proficiency test for heavy metals in compound feed was organised by RIKILT, Wageningen UR in accordance with ISO 17043. RIKILT Wageningen UR has an ISO/IEC 17043 accreditation for proficiency tests of residues in products of animal origin. However, this specific test is not part

  2. A novel approach of utilization of the fungal conidia biomass to remove heavy metals from the aqueous solution through immobilization

    Science.gov (United States)

    Cai, Chun-Xiang; Xu, Jian; Deng, Nian-Fang; Dong, Xue-Wei; Tang, Hao; Liang, Yu; Fan, Xian-Wei; Li, You-Zhi

    2016-11-01

    The biomass of filamentous fungi is an important cost-effective biomass for heavy metal biosorption. However, use of free fungal cells can cause difficulties in the separation of biomass from the effluent. In this study, we immobilized the living conidia of the heavy metal-resistant Penicillium janthinillum strain GXCR by polyvinyl alcohol (PVA)-sodium alginate (SA) beads to remove heavy metals from an aqueous solution containing a low concentration (70 mg/L) of Cu, Pb, and Cd. The PVA-SA-conidia beads showed perfect characters of appropriate mechanical strength suitable for metal removal from the dynamic wastewater environment, an ideal settleability, easy separation from the solution, and a high metal biosorption and removal rate even after four cycles of successive sorption-desorption of the beads, overcoming disadvantages when fungal biomasses alone are used for heavy metal removal from wastewater. We also discuss the major biosorption-affecting factors, biosorption models, and biosorption mechanisms.

  3. Enhanced biological stabilization of heavy metals in sediment using immobilized sulfate reducing bacteria beads with inner cohesive nutrient

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xin, E-mail: hgxlixin@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Dai, Lihua; Zhang, Chang; Zeng, Guangming; Liu, Yunguo [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Zhou, Chen [Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University (United States); Xu, Weihua; Wu, Youe; Tang, Xinquan; Liu, Wei; Lan, Shiming [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China)

    2017-02-15

    Highlights: • Nutrient beads of immobilized SRB were more effective in transforming heavy metals into the more stable bound phases. • Inner cohesive nutrient effectively promoted the stabilization process of heavy metals. • The excellent removal efficiencies of Cu, Zn, Pb and Cd were 76.3%, 95.6%, 100% and 91.2%, respectively. • Easy to recycle and avoid secondary pollution. - Abstract: A series of experiments were conducted for treating heavy metals contaminated sediments sampled from Xiangjiang River, which combined polyvinyl alcohol (PVA) and immobilized sulfate reducing bacteria (SRB) into beads. The sodium lactate was served as the inner cohesive nutrient. Coupling the activity of the SRB with PVA, along with the porous structure and huge specific surface area, provided a convenient channel for the transmission of matter and protected the cells against the toxicity of metals. This paper systematically investigated the stability of Cu, Zn, Pb and Cd and its mechanisms. The results revealed the performance of leaching toxicity was lower and the removal efficiencies of Cu, Zn, Pb and Cd were 76.3%, 95.6%, 100% and 91.2%, respectively. Recycling experiments showed the beads could be reused 5 times with superbly efficiency. These results were also confirmed by continuous extraction at the optimal conditions. Furthermore, X-ray diffraction (XRD) and energy-dispersive spectra (EDS) analysis indicated the heavy metals could be transformed into stable crystal texture. The stabilization of heavy metals was attributed to the carbonyl and acyl amino groups. Results presented that immobilized bacteria with inner nutrient were potentially and practically applied to multi-heavy-metal-contamination sediment.

  4. Coordination compounds of metals with imidazoles and benzimidazoles

    International Nuclear Information System (INIS)

    Novikova, G.A.; Molodkin, A.K.; Kukalenko, S.S.

    1988-01-01

    Methods of preparation, composition and structure of UO 2 2+ , Th 4+ , Mo 3+ , Cd 2+ , Ln 3+ metal ion complexes with imidazoles and benzimidazoles are considered in reviews of native and foreign literature of up to 1985. Complexes are customarily prepared by direct interaction of ligands with inorganic salts in different organic solvents. Complex composition is defined by the nature of complexing metal and inorganic salt anion, ligand volume and basicity, as well as solvent characteristics. Effect of R substituent in imidazole and benzimidazole side chain on composition of coordination compounds is considered

  5. Evaluation of potential for reuse of industrial wastewater using metal-immobilized catalysts and reverse osmosis.

    Science.gov (United States)

    Choi, Jeongyun; Chung, Jinwook

    2015-04-01

    This report describes a novel technology of reusing the wastewater discharged from the display manufacturing industry through an advanced oxidation process (AOP) with a metal-immobilized catalyst and reverse osmosis (RO) in the pilot scale. The reclaimed water generated from the etching and cleaning processes in display manufacturing facilities was low-strength organic wastewater and was required to be recycled to secure a water source. For the reuse of reclaimed water to ultrapure water (UPW), a combination of solid-phase AOP and RO was implemented. The removal efficiency of TOC by solid-phase AOP and RO was 92%. Specifically, the optimal acid, pH, and H2O2 concentrations in the solid-phase AOP were determined. With regard to water quality and operating costs, the combination of solid-phase AOP and RO was superior to activated carbon/RO and ultraviolet AOP/anion polisher/coal carbon. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Preparation and immobilization of noble metal nanoparticles for plasmonic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ruoli; Pitzer, Martin; Hu, DongZhi; Schaadt, Daniel M. [Institut fuer Angewandte Physik, Karlsruher Institut fuer Technologie (KIT), Karlsruhe (Germany); DFG Centrum fuer Funktionelle Nanostrukturen (CFN), KIT (Germany); Fruk, Ljiljana [DFG Centrum fuer Funktionelle Nanostrukturen (CFN), KIT (Germany)

    2011-07-01

    Thin-film solar cells are of high interest due to good electrical properties and low material consumption. Traditional thin-film cells, however, have considerable transmission losses because of the reduced absorption volume. A promising way to enhance absorption in the active layer is the light-trapping by plasmonic nanostructures. Metallic nanoparticles have in particular shown large enhancement of the photocurrent in thin-film devices. In this poster, we present preparation of Au,Ag and Pt nanoparticles by polyol method and seed mediated methods for use in plasmonic solar cells. Polyol method typically uses ethylene glycol as the solvent and reducing agent,and in seed-mediated synthesis small nanoparticle seeds are first prepared and then used to promote the growth of different shapes of nanoparticles. We particularly focus on the use of nanocubes and nanospheres for solar cell design. Following the nanoparticle preparation, a new method to immobilize particles on GaAs surfaces via covalent chemical bonds has been developed which prevents agglomerations and allows control of the surface density. Photocurrent spectra of GaAs pin solar cells with and without particles have been recorded. These measurements show the dependence of the photocurrent enhancement on particle material, shape and density.

  7. Immobilization with Metal Hydroxides as a Means To Concentrate Food-Borne Bacteria for Detection by Cultural and Molecular Methods†

    OpenAIRE

    Lucore, Lisa A.; Cullison, Mark A.; Jaykus, Lee-Ann

    2000-01-01

    The application of nucleic acid amplification methods to the detection of food-borne pathogens could be facilitated by concentrating the organisms from the food matrix before detection. This study evaluated the utility of metal hydroxide immobilization for the concentration of bacterial cells from dairy foods prior to detection by cultural and molecular methods. Using reconstituted nonfat dry milk (NFDM) as a model, two food-borne pathogens (Listeria monocytogenes and Salmonella enterica sero...

  8. Grenade Range Management Using Lime for Dual Role of Metals Immobilization and Explosives Transformation. Field Demonstration at Fort Jackson, SC

    Science.gov (United States)

    2008-09-01

    and reported the results under the sample delivery groups ( SDG ) L128026 and L128720. The following analytical methods were requested on the chains -of... supplies . The application of hydrated lime to an HGR to provide a mechanism for both metals immobilization and explosives transformation was...Offsites 1 and 2 were supplied by RDX from the control bay, Bay 2. Offsite 3 was supplied by the RDX from lime- treated Bay 4. A period of 6 months had

  9. Insertion compounds of transition-metal and uranium oxides

    International Nuclear Information System (INIS)

    Chippindale, A.M.; Dickens, P.G.; Powell, A.V.

    1991-01-01

    Several transition-metal and actinide oxides, in which the metal occurs in a high oxidation state, have open covalent structures and are capable of incorporating alkali and other electropositive metals under mild conditions to form insertion compounds A x MO n . These are solids which have several features in common: Over a range of compositions, A x MO n exists as one or more stable or metastable phases in which the structure of the parent oxide MO n is largely retained and the insertion element A is accommodated interstitially. Insertion is accompanied by a redox process A=A i . + e - M in which M is reduced and the electronic properties of the parent oxide change to those typical of a mixed-valence compound. The insertion process xA + MO n = A x MO n can be reversed, at least to some extent, by chemical or electrochemical reaction, with retention of structure (topotactic reaction). This review concentrates on methods of synthesis, characterisation, crystal structure and thermochemistry of these insertion compounds. It updates and extends previous work. (author)

  10. Effect of immobilized biosorbents on the heavy metals (Cu2+) biosorption with variations of temperature and initial concentration of waste

    Science.gov (United States)

    Siwi, W. P.; Rinanti, A.; Silalahi, M. D. S.; Hadisoebroto, R.; Fachrul, M. F.

    2018-01-01

    The aims of research is to studying the efficiency of copper removal by combining immobilized microalgae with optimizations of temperature and initial Copper concentration. The research was conducted in batch culture with temperature variations of 25°C, 30°C, and 35°C, as well as initial Cu2+ concentrations (mg/l) of 3, 5, 10, 15 and 20 using monoculture of S. cerevisiae, Chlorella sp., and mixed culture of them both as immobilized biosorbents. The optimum adsorption of 83.4% obtained in temperature of 30°C with an initial waste concentration of 17.62 mg/l, initial biomass concentration of 200 mg, pH of 4, and 120 minutes detention time by the immobilized mixed culture biosorbent. The cell morphology examined using Scanning Electron Microscope (SEM) has proved that the biosorbent surface was damaged after being in contact with copper (waste), implying that heavy metals (molecules) attach to different functional cell surfaces and change the biosorbent surface. The adsorption process of this research follows Langmuir Isotherm with the R2 value close to 1. The immobilized mixed culture biosorbent is capable of optimally removing copper at temperature of 30°C and initial Cu2+ concentration of 17.62 mg/l.

  11. Metal immobilization and phosphorus leaching after stabilization of pyrite ash contaminated soil by phosphate amendments.

    Science.gov (United States)

    Zupančič, Marija; Lavrič, Simona; Bukovec, Peter

    2012-02-01

    In this study we would like to show the importance of a holistic approach to evaluation of chemical stabilization using phosphate amendments. An extensive evaluation of metal stabilization in contaminated soil and an evaluation of the leaching of phosphorus induced after treatment were performed. The soil was highly contaminated with Cu (2894 mg kg(-1)), Zn (3884 mg kg(-1)), As (247 mg kg(-1)), Cd (12.6 mg kg(-1)) and Pb (3154 mg kg(-1)). To immobilize the metals, mixtures of soil with phosphate (from H(3)PO(4) and hydroxyapatite (HA) with varying ratios) were prepared with a constant Pb : P molar ratio of 1: 10. The acetic acid extractable concentration of Pb in the mixture with the highest amount of added phosphoric acid (n(H(3)PO(4)) : n(HA) = 3 : 1) was reduced to 1.9% (0.62 mg L(-1)) of the extractable Pb concentration in the untreated soil, but the content of water extractable phosphorus in the samples increased from 0.04 mg L(-1) in the untreated soil sample up to 14.3 mg L(-1) in the same n(H(3)PO(4)) : n(HA) = 3 : 1 mixture. The high increase in arsenic mobility was also observed after phosphate addition. The PBET test showed phosphate induced reduction in Pb bioavailability. In attempting to stabilize Pb in the soil with the minimum treatment-induced leaching of phosphorus, it was found that a mixture of soil with phosphate addition in the molar ratio of H(3)PO(4) : HA of 0.75 : 1 showed the most promising results, with an acetic acid extractable Pb concentration of 1.35 mg L(-1) and a water extractable phosphorus concentration of 1.76 mg L(-1). The time-dependent leaching characteristics of metals and phosphorus for this mixture were evaluated by a column experiment, where irrigation of the soil mixture with the average annual amount of precipitation in Slovenia (1000 mm) was simulated. The phosphorus concentration in the leachates decreased from 2.60 mg L(-1) at the beginning of irrigation to 1.00 mg L(-1) at the end.

  12. Techniques for assessing the performance of in situ bioreduction and immobilization of metals and radionuclides in contaminated subsurface environments

    Energy Technology Data Exchange (ETDEWEB)

    Jardine, P.M.; Watson, D.B.; Blake, D.A.; Beard, L.P.; Brooks, S.C.; Carley, J.M.; Criddle, C.S.; Doll, W.E.; Fields, M.W.; Fendorf, S.E.; Geesey, G.G.; Ginder-Vogel, M.; Hubbard, S.S.; Istok, J.D.; Kelly, S.; Kemner, K.M.; Peacock, A.D.; Spalding, B.P.; White, D.C.; Wolf, A.; Wu, W.; Zhou, J.

    2004-11-14

    Department of Energy (DOE) facilities within the weapons complex face a daunting challenge of remediating huge below inventories of legacy radioactive and toxic metal waste. More often than not, the scope of the problem is massive, particularly in the high recharge, humid regions east of the Mississippi river, where the off-site migration of contaminants continues to plague soil water, groundwater, and surface water sources. As of 2002, contaminated sites are closing rapidly and many remediation strategies have chosen to leave contaminants in-place. In situ barriers, surface caps, and bioremediation are often the remedial strategies of chose. By choosing to leave contaminants in-place, we must accept the fact that the contaminants will continue to interact with subsurface and surface media. Contaminant interactions with the geosphere are complex and investigating long term changes and interactive processes is imperative to verifying risks. We must be able to understand the consequences of our action or inaction. The focus of this manuscript is to describe recent technical developments for assessing the performance of in situ bioremediation and immobilization of subsurface metals and radionuclides. Research within DOE's NABIR and EMSP programs has been investigating the possibility of using subsurface microorganisms to convert redox sensitive toxic metals and radionuclides (e.g. Cr, U, Tc, Co) into a less soluble, less mobile forms. Much of the research is motivated by the likelihood that subsurface metal-reducing bacteria can be stimulated to effectively alter the redox state of metals and radionuclides so that they are immobilized in situ for long time periods. The approach is difficult, however, since subsurface media and waste constituents are complex with competing electron acceptors and hydrogeological conditions making biostimulation a challenge. Performance assessment of in situ biostimulation strategies is also difficult and typically requires detailed

  13. Immobilization of Cr(Vi) as a contaminant from soil by iron compounds

    International Nuclear Information System (INIS)

    Marin A, M. de J.; Romero G, E. T.; Reyes G, L. R.

    2008-01-01

    The objective of this research was to determine the physicochemical and surface properties of Fe 0 and FeS to select the appropriate radioactive material for use in the design of artificial barriers or walls and remove Cr (Vi). The physicochemical characterization was carried out of iron: Fe 0 and FeS, using scanning electron microscopy of high vacuum, X-ray diffraction and thermal gravimetric analysis techniques. As for the characterization of the surface, was used to determine the surface area, point of zero charge, density of active sites and kinetics of moisture. We obtained a solution of Cr (Vi) by elution of deionized water on the pollution land of Buenavista, Guanajuato. The concentration of Cr (Vi) from a stock solution was 55.56 mg / L determined by UV-Vis spectrophotometry. Stripping or maximum immobilization of Cr (Vi) with Fe 0 (material chosen by their physicochemical and surface properties) was 68.25% using Fe 0 , at a concentration less than 0.1, ph equal to 3 and a contact time of 24 hours. (Author)

  14. Immobilization of kojic acid in ZnAl-hydrotalcite like compounds

    Science.gov (United States)

    Ambrogi, Valeria; Perioli, Luana; Nocchetti, Morena; Latterini, Loredana; Pagano, Cinzia; Massetti, Elena; Rossi, Carlo

    2012-01-01

    Kojic acid (KOJ) is a melanin synthesis inhibitor widely used as skin lightening agent in topical preparations. Unfortunately it is easily susceptible to photo-oxidation, phenomenon responsible for chemical and organoleptic modifications. The aim of this work was the intercalation of KOJ in hydrotalcite-like compounds (HTlc) in order to stabilize KOJ and to reduce its photolability. Hydrotalcite containing Zn and Al (ZnAl-HTlc) was used as host to obtain the final compound ZnAl-HTlc-KOJ. The intercalation was carried out, after many attempts, by ionic exchange mechanism by means of the strong base EtO- in anhydrous ethanol/dimethylsulfoxide (DMSO) mixture as solvent in order to generate KOJ- anions. The final product was characterized by the X-ray powder diffraction (XRPD), FT-IR spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and elemental analysis. The intercalated compound was formulated in a siliconic water free self-emulsifying ointment and the in vitro release profile was evaluated. All samples (intercalation compound and its formulation) were submitted also to spectrophotometric assays in order to evaluate the matrix protective effect towards ultraviolet rays.

  15. One step bioconversion of waste precious metals into Serratia biofilm-immobilized catalyst for Cr(VI) reduction.

    Science.gov (United States)

    Yong, P; Liu, W; Zhang, Z; Beauregard, D; Johns, M L; Macaskie, L E

    2015-11-01

    For reduction of Cr(VI) the Pd-catalyst is excellent but costly. The objectives were to prove the robustness of a Serratia biofilm as a support for biogenic Pd-nanoparticles and to fabricate effective catalyst from precious metal waste. Nanoparticles (NPs) of palladium were immobilized on polyurethane reticulated foam and polypropylene supports via adhesive biofilm of a Serratia sp. The biofilm adhesion and cohesion strength were unaffected by palladization and catalytic biofilm integrity was also shown by magnetic resonance imaging. Biofilm-Pd and mixed precious metals on biofilm (biofilm-PM) reduced 5 mM Cr(VI) to Cr(III) when immobilized in a flow-through column reactor, at respective flow rates of 9 and 6 ml/h. The lower activity of the latter was attributed to fewer, larger, metal deposits on the bacteria. Activity was lost in each case at pH 7 but was restored by washing with 5 mM citrate solution or by exposure of columns to solution at pH 2, suggesting fouling by Cr(III) hydroxide product at neutral pH. A 'one pot' conversion of precious metal waste into new catalyst for waste decontamination was shown in a continuous flow system based on the use of Serratia biofilm to manufacture and support catalytic Pd-nanoparticles.

  16. Preparation of nano-biomaterials with Leptolyngbia foveolarum and heavy metal biosorption by free and immobilized algal cells

    International Nuclear Information System (INIS)

    Toncheva-Panova, T.; Pouneva, I.; Sholeva, M.; Chernev, G.

    2010-01-01

    Using the sol-gel procedure nano-biomaterials with incorporation of Leptolyngbia foveolarum in the silica matrix were manufactured. The immobilization of algal cells was confirmed with Scanning Electron Microscopy (SEM) investigations and photos. Observation of nano-biomaterials with Atomic Force Microscopy (AFM) shows nanostructure with well-defined nanounits and their aggregates. The potential of the Antarctic isolate L. foveolarum for sorption of Cu 2+ and Cd 2+ was studied by incubation of free algal cells and those immobilized in nano-biomaterials in the salts solutions of the two heavy metals. The rest of the heavy metal was determined with inductively coupled plasma atomic emission spectrometer (ICP-AES). It was established that the heavy metal biosorption capacity demonstrated by the free Leptolyngbia cells was retained after their incorporation in the nano-matrices. Free cells as well as embedded in silica nano-matrix sequestered the two heavy metals with greater affinity for copper. The highest binding capacity, 76% of the initial Cu 2+ concentration possessed nano-biomaterials with incorporated vegetative L. foveolarum cells, compared to 68% of free cells. For cadmium the degree of biosorption was lower - 35% by free cells and 30.2% by those incorporated in the biocer. (authors)

  17. Immobilization of Thiadiazole Derivatives on Magnetite Mesoporous Silica Shell Nanoparticles in Application to Heavy Metal Removal from Biological Samples

    International Nuclear Information System (INIS)

    Emadi, Masoomeh; Shams, Esmaeil

    2010-01-01

    In this report magnetite was synthesized by a coprecipitation method, then coated with a layer of silica. Another layer of mesoporous silica was added by a sol-gel method, then 5-amino-1,3,4-thiadiazole-thiol (ATT) was immobilized onto the synthesized nanoparticles with a simple procedure. This was followed by a series of characterizations, including transmission electron microscopy (TEM), FT-IR spectrum, elemental analysis and XRD. Heavy metal uptake of the modified nanoparticles was examined by atomic absorption spectroscopy. For further investigation we chose Cu 2+ as the preferred heavy metal to evaluate the amount of adsorption, as well as the kinetics and mechanism of adsorption. Finally, the capacity of our nanoparticles for the heavy metal removal from blood was shown. We found that the kinetic rate of Cu 2+ adsorption was 0.05 g/mg/min, and the best binding model was the Freundlich isotherm.

  18. Electron and nuclear magnetic resonances in compounds and metallic hydrides

    International Nuclear Information System (INIS)

    Brasil Filho, N.

    1985-11-01

    Proton pulsed Nuclear Magnetic Resonance measurements were performed on the metallic hydrides ZrCr 2 H x (x = 2, 3, 4) and ZrV 2 H y (y = 2, 3, 4, 5) as a function of temperature between 180 and 400K. The ultimate aim was the investigation of the relaxation mechanisms in these systems by means of the measurement of both the proton ( 1 H) spin-lattice (T 1 ) and spin-spin (T 2 ) relaxation times and to use these data to obtain information about the diffusive motion of the hydrogen atoms. The diffusional activation energies, the jump frequencies and the Korringa constant, C k , related with the conduction electron contribution to the 1 H relaxation were determined for the above hydrides as a function of hydrogen concentration. Our results were analysed in terms of the relaxation models described by Bloembergen, Purcell and Pound (BPP model) and by Torrey. The Korringa type relaxation due to the conduction electrons in metallic systems was also used to interpret the experimental results. We also present the Electron Paramagnetic Ressonance (EPR) study of Gd 3+ , Nd 3+ and Er 3+ ions as impurities in several AB 3 intermetallic compounds where A = LA, Ce, Y, Sc, Th, Zr and B = Rh, Ir, Pt. The results were analysed in terms of the multiband model previously suggested to explain the behaviour of the resonance parameter in AB 2 Laves Phase compounds. (author) [pt

  19. Heterocycles by Transition Metals Catalyzed Intramolecular Cyclization of Acetylene Compounds

    International Nuclear Information System (INIS)

    Vizer, S.A.; Yerzhanov, K.B.; Dedeshko, E.C.

    2003-01-01

    Review shows the new strategies in the synthesis of heterocycles, having nitrogen, oxygen and sulfur atoms, via transition metals catalyzed intramolecular cyclization of acetylenic compounds on the data published at the last 30 years, Unsaturated heterocyclic compounds (pyrroles and pyrroline, furans, dihydro furans and benzofurans, indoles and iso-indoles, isoquinolines and isoquinolinones, aurones, iso coumarins and oxazolinone, lactams and lactones with various substitutes in heterocycles) are formed by transition metals, those salts [PdCl 2 , Pd(OAc) 2 , HgCl 2 , Hg(OAc) 2 , Hg(OCOCF 3 ) 2 , AuCl 3 ·2H 2 O, NaAuCl 4 ·2H 2 O, CuI, CuCl], oxides (HgO) and complexes [Pd(OAc) 2 (PPh 3 )2, Pd(PPh 3 ) 4 , PdCl 2 (MeCN) 2 , Pd(OAc ) 2 /TPPTS] catalyzed intramolecular cyclization of acetylenic amines, amides, ethers, alcohols, acids, ketones and βdiketones. More complex hetero polycyclic systems typical for natural alkaloids can to obtain similar. Proposed mechanisms of pyrroles, isoquinolines, iso indoles and indoles, benzofurans and iso coumarins, thiazolopyrimidinones formation are considered. (author)

  20. Secondary electron emission from metals and semi-conductor compounds

    International Nuclear Information System (INIS)

    Ono, Susumu; Kanaya, Koichi

    1979-01-01

    Attempt was made to present the sufficient solution of the secondary electron yield of metals and semiconductor compounds except insulators, applying the free electron scattering theory to the absorption of secondary electrons generated within a solid target. The paper is divided into the sections describing absorption coefficient and escape depth, quantitative characteristics of secondary yield, angular distribution of secondary electron emission, effect of incident angle to secondary yield, secondary electron yield transmitted, and lateral distribution of secondary electron emission, besides introduction and conclusion. The conclusions are as follows. Based on the exponential power law for screened atomic potential, secondary electron emission due to both primary and backscattered electrons penetrating into metallic elements and semi-conductive compounds is expressed in terms of the ionization loss in the first collision for escaping secondary electrons. The maximum yield and the corresponding primary energy can both consistently be derived as the functions of three parameters: atomic number, first ionization energy and backscattering coefficient. The yield-energy curve as a function of the incident energy and the backscattering coefficient is in good agreement with the experimental results. The energy dependence of the yield in thin films and the lateral distribution of secondary yield are derived as the functions of the backscattering coefficient and the primary energy. (Wakatsuki, Y.)

  1. Immobilization of Bacillus subtilis lipase on a Cu-BTC based hierarchically porous metal-organic framework material: a biocatalyst for esterification.

    Science.gov (United States)

    Cao, Yu; Wu, Zhuofu; Wang, Tao; Xiao, Yu; Huo, Qisheng; Liu, Yunling

    2016-04-28

    Bacillus subtilis lipase (BSL2) has been successfully immobilized into a Cu-BTC based hierarchically porous metal-organic framework material for the first time. The Cu-BTC hierarchically porous MOF material with large mesopore apertures is prepared conveniently by using a template-free strategy under mild conditions. The immobilized BSL2 presents high enzymatic activity and perfect reusability during the esterification reaction. After 10 cycles, the immobilized BSL2 still exhibits 90.7% of its initial enzymatic activity and 99.6% of its initial conversion.

  2. Comparison of immobilized poly-L-aspartic acid and poly-L-glutamic acid for chelation of metal cations

    International Nuclear Information System (INIS)

    Malachowski, Lisa; Holcombe, James A.

    2004-01-01

    Poly-L-aspartic acid (PLAsp) and poly-L-glutamic acid (PLGlu) were individually immobilized onto controlled pore glass (CPG) and compared according to their metal-binding capabilities in a solution of pH 7.0. The metal-binding capacities were calculated through the analysis of breakthrough curves generated by monitoring the metal concentrations on a flow injection-flame atomic absorption system. Capacities for individual metals were comparable and in the order of Cu 2+ >> Pb 2+ > Ni 2+ ∼ Cd 2+ > Co 2+ > Mn 2+ >> Na + . Elemental combustion analysis yielded polymer coverage on the CPG of approximately 4 x 10 12 to 5 x 10 12 chains/cm 2 , when average chain lengths were used in the calculations. Formation constants and site capacities of both polymers for Cd 2+ were determined through equilibrium and breakthrough studies. The maximum log K values for the strong sites were determined to be ∼13 for both PLAsp and for PLGlu. Additionally, the metal selectivity of PLAsp and PLGlu was evaluated when breakthrough curves were run with several metals present in solution at one time. Both polymers showed selectivities in the order of their single metal-binding capacities, i.e., Cu 2+ > Pb 2+ > Ni 2+ ∼ Cd 2+ . Both polymers exhibited similar binding trends and binding strengths for all of the metals studied. This likely reflects the absence of a predetermined tertiary structure of the polymers on the surface and the relatively high residue-per-metal ratio (∼20:1), which places less stringent requirements on the steric hindrance between the side chains and the resultant 'wrapping' of the peptide around the metal

  3. Coordination compounds of metals with imidazoles and benzimidazoles. [Metals: V, Th, Mo, Cd, rare earths, etc

    Energy Technology Data Exchange (ETDEWEB)

    Novikova, G A; Molodkin, A K; Kukalenko, S S

    1988-12-01

    Methods of preparation, composition and structure of UO/sub 2//sup 2+/, Th/sup 4+/, Mo/sup 3+/, Cd/sup 2+/, Ln/sup 3+/ metal ion complexes with imidazoles and benzimidazoles are considered in reviews of native and foreign literature of up to 1985. Complexes are customarily prepared by direct interaction of ligands with inorganic salts in different organic solvents. Complex composition is defined by the nature of complexing metal and inorganic salt anion, ligand volume and basicity, as well as solvent characteristics. Effect of R substituent in imidazole and benzimidazole side chain on composition of coordination compounds is considered.

  4. High density gold nanoparticles immobilized on surface via plasma deposited APTES film for decomposing organic compounds in microchannels

    Science.gov (United States)

    Rao, Xi; Guyon, Cédric; Ognier, Stephanie; Da Silva, Bradley; Chu, Chenglin; Tatoulian, Michaël; Hassan, Ali Abou

    2018-05-01

    Immobilization of colloidal particles (e.g. gold nanoparticles (AuNps)) on the inner surface of micro-/nano- channels has received a great interest for catalysis. A novel catalytic ozonation setup using a gold-immobilized microchannel reactor was developed in this work. To anchor AuNps, (3-aminopropyl) triethoxysilane (APTES) with functional amine groups was deposited using plasma enhanced chemical vapor deposition (PECVD) process. The results clearly evidenced that PECVD processing exhibited relatively high efficiency for grafting amine groups and further immobilizing AuNPs. The catalytic activity of gold immobilized microchannel was evaluated by pyruvic acid ozonation. The decomposition rate calculated from High Performance Liquid Chromatography (HPLC) indicated a much better catalytic performance of gold in microchannel than that in batch. The results confirmed immobilizing gold nanoparticles on plasma deposited APTES for preparing catalytic microreactors is promising for the wastewater treatment in the future.

  5. Preparation of biosensors by immobilization of polyphenol oxidase in conducting copolymers and their use in determination of phenolic compounds in red wine.

    Science.gov (United States)

    Böyükbayram, A Elif; Kiralp, Senem; Toppare, Levent; Yağci, Yusuf

    2006-10-01

    Electrochemically produced graft copolymers of thiophene capped polytetrahydofuran (TPTHF1 and TPTHF2) and pyrrole were achieved by constant potential electrolysis using sodium dodecylsulfate (SDS) as the supporting electrolyte. Characterizations were based on Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Electrical conductivities were measured by the four-probe technique. Novel biosensors for phenolic compounds were constructed by immobilizing polyphenol oxidase (PPO) into conducting copolymers prepared by electropolymerization of pyrrole with thiophene capped polytetrahydrofuran. Kinetic parameters, maximum reaction rate (V(max)) and Michaelis-Menten constant (K(m)) and optimum conditions regarding temperature and pH were determined for the immobilized enzyme. Operational stability and shelf-life of the enzyme electrodes were investigated. Enzyme electrodes of polyphenol oxidase were used to determine the amount of phenolic compounds in two brands of Turkish red wines and found very useful owing to their high kinetic parameters and wide pH working range.

  6. Evaluation of heavy metals in hazardous automobile shredder residue thermal residue and immobilization with novel nano-size calcium dispersed reagent

    International Nuclear Information System (INIS)

    Lee, Chi-Hyeon; Truc, Nguyen Thi Thanh; Lee, Byeong-Kyu; Mitoma, Yoshiharu; Mallampati, Srinivasa Reddy

    2015-01-01

    Graphical abstract: Schematic representation of possible mechanisms determining the heavy metals immobilization efficiencyof ASR dust/thermal residues after treatment with nanometallic Ca/CaO/PO 4 . - Highlights: • Nanometallic Ca/CaO/PO 4 for heavy metals immobilization in ASR residue. • Heavy metals immobilization in dry condition attained about 95–100%. • Remaining heavy metals were lower than the Korean standard regulatory limit. • The amounts of heavy metals detectable on the ASR dust surface decreased. • Nanometallic Ca/CaO/PO 4 has a promising potential for heavy metal remediation. - Abstract: This study was conducted to synthesize and apply a nano-size calcium dispersed reagent as an immobilization material for heavy metal-contaminated automobile shredder residues (ASR) dust/thermal residues in dry condition. Simple mixing with a nanometallic Ca/CaO/PO 4 dispersion mixture immobilized 95–100% of heavy metals in ASR dust/thermal residues (including bottom ash, cavity ash, boiler and bag filter ash). The quantity of heavy metals leached from thermal residues after treatment by nanometallic Ca/CaO/PO 4 was lower than the Korean standard regulatory limit for hazardous waste landfills. The morphology and elemental composition of the nanometallic Ca/CaO-treated ASR residue were characterized by field emission scanning election microscopy combined with electron dispersive spectroscopy (FE-SEM/EDS). The results indicated that the amounts of heavy metals detectable on the ASR thermal residue surface decreased and the Ca/PO 4 mass percent increased. X-ray diffraction (XRD) pattern analysis indicated that the main fraction of enclosed/bound materials on ASR residue included Ca/PO 4 − associated crystalline complexes, and that immobile Ca/PO 4 salts remarkably inhibited the desorption of heavy metals from ASR residues. These results support the potential use of nanometallic Ca/CaO/PO 4 as a simple, suitable and highly efficient material for the gentle

  7. Evaluation of heavy metals in hazardous automobile shredder residue thermal residue and immobilization with novel nano-size calcium dispersed reagent

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chi-Hyeon; Truc, Nguyen Thi Thanh [Department of Civil and Environmental Engineering, University of Ulsan, Daehak-ro 93, Nam-gu, Ulsan 680-749 (Korea, Republic of); Lee, Byeong-Kyu, E-mail: bklee@ulsan.ac.kr [Department of Civil and Environmental Engineering, University of Ulsan, Daehak-ro 93, Nam-gu, Ulsan 680-749 (Korea, Republic of); Mitoma, Yoshiharu [Department of Environmental Sciences, Prefectural University of Hiroshima, 562 Nanatsuka-Cho Shobara City, Hiroshima 727-0023 (Japan); Mallampati, Srinivasa Reddy, E-mail: srireddys@ulsan.ac.kr [Department of Civil and Environmental Engineering, University of Ulsan, Daehak-ro 93, Nam-gu, Ulsan 680-749 (Korea, Republic of)

    2015-10-15

    Graphical abstract: Schematic representation of possible mechanisms determining the heavy metals immobilization efficiencyof ASR dust/thermal residues after treatment with nanometallic Ca/CaO/PO{sub 4}. - Highlights: • Nanometallic Ca/CaO/PO{sub 4} for heavy metals immobilization in ASR residue. • Heavy metals immobilization in dry condition attained about 95–100%. • Remaining heavy metals were lower than the Korean standard regulatory limit. • The amounts of heavy metals detectable on the ASR dust surface decreased. • Nanometallic Ca/CaO/PO{sub 4} has a promising potential for heavy metal remediation. - Abstract: This study was conducted to synthesize and apply a nano-size calcium dispersed reagent as an immobilization material for heavy metal-contaminated automobile shredder residues (ASR) dust/thermal residues in dry condition. Simple mixing with a nanometallic Ca/CaO/PO{sub 4} dispersion mixture immobilized 95–100% of heavy metals in ASR dust/thermal residues (including bottom ash, cavity ash, boiler and bag filter ash). The quantity of heavy metals leached from thermal residues after treatment by nanometallic Ca/CaO/PO{sub 4} was lower than the Korean standard regulatory limit for hazardous waste landfills. The morphology and elemental composition of the nanometallic Ca/CaO-treated ASR residue were characterized by field emission scanning election microscopy combined with electron dispersive spectroscopy (FE-SEM/EDS). The results indicated that the amounts of heavy metals detectable on the ASR thermal residue surface decreased and the Ca/PO{sub 4} mass percent increased. X-ray diffraction (XRD) pattern analysis indicated that the main fraction of enclosed/bound materials on ASR residue included Ca/PO{sub 4}− associated crystalline complexes, and that immobile Ca/PO{sub 4} salts remarkably inhibited the desorption of heavy metals from ASR residues. These results support the potential use of nanometallic Ca/CaO/PO{sub 4} as a simple, suitable and

  8. Development of an immobilization process for heavy metal containing galvanic solid wastes by use of sodium silicate and sodium tetraborate

    Energy Technology Data Exchange (ETDEWEB)

    Aydın, Ahmet Alper, E-mail: ahmetalperaydin@gmail.com [Chair of Urban Water Systems Engineering, Technische Universität München, Am Coulombwall, 85748 Garching (Germany); Aydın, Adnan [Istanbul Bilim University, School of Health, Esentepe, Istanbul, Sisli, 34394 (Turkey)

    2014-04-01

    Highlights: • A new physico-chemical process below 1000 °C for immobilization of galvanic sludges. • Sodium tetraborate and sodium silicate have been used as additives. • A strategy for adjustment of solid waste/additive mixture composition is presented. • Strategy is valid for wastes of hydrometallurgical and electro-plating processes. • Lower energy consumption and treated waste volume, shorter process time are provided. - Abstract: Heavy metal containing sludges from wastewater treatment plants of electroplating industries are designated as hazardous waste since their improper disposal pose high risks to environment. In this research, heavy metal containing sludges of electroplating industries in an organized industrial zone of Istanbul/Turkey were used as real-sample model for development of an immobilization process with sodium tetraborate and sodium silicate as additives. The washed sludges have been precalcined in a rotary furnace at 900 °C and fritted at three different temperatures of 850 °C, 900 °C and 950 °C. The amounts of additives were adjusted to provide different acidic and basic oxide ratios in the precalcined sludge-additive mixtures. Leaching tests were conducted according to the toxicity characteristic leaching procedure Method 1311 of US-EPA. X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscope-energy dispersive spectrometer (SEM-EDS) and flame atomic absorption spectroscopy (FAAS) have been used to determine the physical and chemical changes in the products. Calculated oxide molar ratios in the precalcined sludge-additive mixtures and their leaching results have been used to optimize the stabilization process and to determine the intervals of the required oxide ratios which provide end-products resistant to leaching procedure of US-EPA. The developed immobilization-process provides lower energy consumption than sintering-vitrification processes of glass–ceramics.

  9. Correlated effective field theory in transition metal compounds

    International Nuclear Information System (INIS)

    Mukhopadhyay, Subhasis; Chatterjee, Ibha

    2004-01-01

    temperature, stoichiometric composition. The magnetic properties of these compounds can be studied very well with the CEF theory. The physics of the insulating phase should definitely play an important role in these oxides which show metallic and superconducting behaviour as a function of doping in the parent compounds which are Mott insulators

  10. COORDINATION COMPOUNDS OF 3D-METALS ACETYLACETONATES WITH THIOSEMICARBAZIDE

    Directory of Open Access Journals (Sweden)

    T. V. Koksharova

    2015-03-01

    Full Text Available Coordination Compounds of 3d-Metals acetylacetonates with Thiosemicarbazide were synthesized. Their physical and chemical properties and structure were studied by conductometry, IR spectroscopy, electronic spectroscopy, magnetochemistry and thermo-gravimetricstudies. The complexes compositions correspond to the formulas Co(L2(Acac and M(L(Acac, where M = Cu, Ni, Zn, HL is thiosemicarbazide, HAcac is acetylacetone. All of them are nonelectrolytes. Thiosemicarbazide is deprotonated and coordinated through the nitrogen and sulphur atoms with the formation of four-membered ring in all cases. Acetylacetonate co-ordination mode does not change at acetylacetonates with Thiosemicarbazide interaction. Copper(II and nickel(II complexes have square-planar structure, and cobalt(III complex is octahedral.

  11. NMR in metal cluster compounds compared to glasses

    International Nuclear Information System (INIS)

    Staveren, M.P.J. van; Brom, H.B.; Jongh, L.J. de; Schmid, G.

    1991-01-01

    The field and temperature dependence of the 31 P nuclear spin lattice relaxation rate in the metal cluster compound Ru 55 (P(t-Bu) 3 ) 12 Cl 20 follows a power law: 1/T 1 ∝ T n B -m , with n = 1.5 ± 0.1 at 3.25 T and n = 1.3 ± 0.1 at 6.45 T; m ≅ 1.4. Such dependences have so far only been observed in inorganic glasses and been attributed to two level systems. The correspondence suggests that the relaxation rate is due to interaction of the P-nuclear moment with electronic spins of stochastically moving charge carriers, which are thought to be responsible for the electrical conductivity through hopping between neigboring cluster molecules. (orig.)

  12. Evaluation of heavy metals in hazardous automobile shredder residue thermal residue and immobilization with novel nano-size calcium dispersed reagent.

    Science.gov (United States)

    Lee, Chi-Hyeon; Truc, Nguyen Thi Thanh; Lee, Byeong-Kyu; Mitoma, Yoshiharu; Mallampati, Srinivasa Reddy

    2015-10-15

    This study was conducted to synthesize and apply a nano-size calcium dispersed reagent as an immobilization material for heavy metal-contaminated automobile shredder residues (ASR) dust/thermal residues in dry condition. Simple mixing with a nanometallic Ca/CaO/PO4 dispersion mixture immobilized 95-100% of heavy metals in ASR dust/thermal residues (including bottom ash, cavity ash, boiler and bag filter ash). The quantity of heavy metals leached from thermal residues after treatment by nanometallic Ca/CaO/PO4 was lower than the Korean standard regulatory limit for hazardous waste landfills. The morphology and elemental composition of the nanometallic Ca/CaO-treated ASR residue were characterized by field emission scanning election microscopy combined with electron dispersive spectroscopy (FE-SEM/EDS). The results indicated that the amounts of heavy metals detectable on the ASR thermal residue surface decreased and the Ca/PO4 mass percent increased. X-ray diffraction (XRD) pattern analysis indicated that the main fraction of enclosed/bound materials on ASR residue included Ca/PO4- associated crystalline complexes, and that immobile Ca/PO4 salts remarkably inhibited the desorption of heavy metals from ASR residues. These results support the potential use of nanometallic Ca/CaO/PO4 as a simple, suitable and highly efficient material for the gentle immobilization of heavy metals in hazardous ASR thermal residue in dry condition. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Subcritical water treatment of explosive and heavy metals co-contaminated soil: Removal of the explosive, and immobilization and risk assessment of heavy metals.

    Science.gov (United States)

    Islam, Mohammad Nazrul; Jung, Ho-Young; Park, Jeong-Hun

    2015-11-01

    Co-contamination of explosives and heavy metals (HMs) in soil, particularly army shooting range soil, has received increasing environmental concern due to toxicity and risks to ecological systems. In this study, a subcritical water (SCW) extraction process was used to remediate the explosives-plus-HMs-co-contaminated soil. A quantitative evaluation of explosives in the treated soil, compared with untreated soil, was applied to assess explosive removal. The immobilization of HMs was assessed by toxicity characteristic leaching procedure tests, and by investigating the migration of HMs fractions. The environmental risk of HMs in the soil residue was assessed according to the risk assessment code (RAC) and ecological risk indices (Er and RI). The results indicated that SCW treatment could eliminate the explosives, >99%, during the remediation, while the HM was effectively immobilized. The effect of water temperature on reducing the explosives and the risk of HMs in soil was observed. A marked increase in the non-bioavailable concentration of each HM was observed, and the leaching rate of HMs was decreased by 70-97% after SCW treatment at 250 °C, showing the effective immobilization of HMs. According to the RAC or RI, each tested HM showed no or low risk to the environment after treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Preparation of Metal Immobilized Orange Waste Gel for Arsenic(V Removal From Water

    Directory of Open Access Journals (Sweden)

    Biplob Kumar Biswas

    2014-05-01

    Full Text Available Abstract - The toxicity of arsenic is known to be a risk to aquatic flora and fauna and to human health even in relatively low concentration. In this research an adsorption gel was prepared from agricultural waste material (orange waste through simple chemical modification in the view to remove arsenic (V from water. Orange waste was crushed into small particles and saponified with Ca(OH2 to prepare saponified orange waste, which was further modified by immobilizing gadolinium(III to obtain desired adsorption material (Gd(III-immobilized SOW gel. The effective pH range for arsenic adsorption was found to be 7.5 – 8.5. Adsorption capacity of the gel was evaluated to be 0.45 mol-arsenic (V/kg. Dynamic adsorption of arsenic (V in column-mode was conducted and a dynamic capacity was found to be 0.39 mol/kg. Elution of arsenate was tested after complete saturation of the column packed with gadolinium-immobilized orange waste adsorption gel. A complete elution of arsenate was achieved with the help of 1 M HCl and 28 times pre-concentration factor was attained. This study showed that a cheap and abundant agro-industrial waste material could be successfully employed for the remediation of arsenic pollution in aquatic environment. Keywords: Arsenic; Orange waste; Gadolinium(III; Adsorption; Elution.

  15. Sulfur-aided phytoextraction of Cd and Zn by Salix smithiana combined with in situ metal immobilization by gravel sludge and red mud

    International Nuclear Information System (INIS)

    Iqbal, Muhammad; Puschenreiter, Markus; Oburger, Eva; Santner, Jakob; Wenzel, Walter W.

    2012-01-01

    As phytoextraction implementation may be limited by metal toxicity and leaching, we investigated the idea of in situ metal immobilization in bulk soil, while increasing metal bioavailability in the rhizosphere. Salix smithiana was grown in a pot experiment on two Cd/Zn polluted soils. Treatments with or without willows included: no additives; gravel sludge + red mud kg −1 ; acidification with S to pH 3.5; and metal immobilization combined with soil acidification. Salix smithiana removed up to 0.78 ± 0.06% total Cd and 0.34% (±0.02) total Zn from the non-treated soils. The phytoextraction efficiency in the S treatments was enhanced by up to ∼50% in response to metal solubility that was magnified by reductive co-dissolution from Mn (IV) and Fe(III) (oxy)hydroxides during microbial S oxidation in the willow rhizosphere. The proposed technique proved to enhance phytoextraction efficiency while controlling the risk of metal leaching from the root zone and phytotoxicity. - Highlights: ► Phytoextraction of Cd and Zn using willow (Salix smithiana) was enhanced by elemental sulfur. ► Reductive metals dissolution by microbial S oxidation was magnified in the willow rhizosphere. ► Thus metal bioavailability was high at the location of uptake in the phytoextraction crop. ► Concurrent immobilization by soil amendments can reduce metal leaching from the bulk soil. - Magnified Cd and Zn availability in S-amended rhizosphere of Salix smithiana enhances shoot Cd/Zn removal while metal leaching from the root zone can be reduced by immobilizing soil amendments.

  16. Mycoextraction by Clitocybe maxima combined with metal immobilization by biochar and activated carbon in an aged soil.

    Science.gov (United States)

    Wu, Bin; Cheng, Guanglei; Jiao, Kai; Shi, Wenjin; Wang, Can; Xu, Heng

    2016-08-15

    To develop an eco-friendly and efficient route to remediate soil highly polluted with heavy metals, the idea of mycoextraction combined with metal immobilization by carbonaceous sorbents (biochar and activated carbon) was investigated in this study. Results showed that the application of carbonaceous amendments decreased acid soluble Cd and Cu by 5.13-14.06% and 26.86-49.58%, respectively, whereas the reducible and oxidizable fractions increased significantly as the amount of carbonaceous amendments added increased. The biological activities (microbial biomass, soil enzyme activities) for treatments with carbonaceous sorbents were higher than those of samples without carbonaceous amendments. Clitocybe maxima (C. maxima) simultaneously increased soil enzyme activities and the total number of microbes. Biochar and activated carbon both showed a positive effect on C. maxima growth and metal accumulation. The mycoextraction efficiency of Cd and Cu in treatments with carbonaceous amendments enhanced by 25.64-153.85% and 15.18-107.22%, respectively, in response to that in non-treated soil, which showed positive correlation to the augment of biochar and activated carbon in soil. Therefore, this work suggested the effectiveness of mycoextraction by C. maxima combined the application of biochar and activated carbon in immobilising heavy metal in contaminated soil. Copyright © 2016. Published by Elsevier B.V.

  17. Inhibition of acid mine drainage and immobilization of heavy metals from copper flotation tailings using a marble cutting waste

    Science.gov (United States)

    Tozsin, Gulsen

    2016-01-01

    Acid mine drainage (AMD) with high concentrations of sulfates and metals is generated by the oxidation of sulfide bearing wastes. CaCO3-rich marble cutting waste is a residual material produced by the cutting and polishing of marble stone. In this study, the feasibility of using the marble cutting waste as an acid-neutralizing agent to inhibit AMD and immobilize heavy metals from copper flotation tailings (sulfide- bearing wastes) was investigated. Continuous-stirring shake-flask tests were conducted for 40 d, and the pH value, sulfate content, and dissolved metal content of the leachate were analyzed every 10 d to determine the effectiveness of the marble cutting waste as an acid neutralizer. For comparison, CaCO3 was also used as a neutralizing agent. The average pH value of the leachate was 2.1 at the beginning of the experiment ( t = 0). In the experiment employing the marble cutting waste, the pH value of the leachate changed from 6.5 to 7.8, and the sulfate and iron concentrations decreased from 4558 to 838 mg/L and from 536 to 0.01 mg/L, respectively, after 40 d. The marble cutting waste also removed more than 80wt% of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) from AMD generated by copper flotation tailings.

  18. Slow pyrolyzed biochars from crop residues for soil metal(loid) immobilization and microbial community abundance in contaminated agricultural soils.

    Science.gov (United States)

    Igalavithana, Avanthi Deshani; Park, Jinje; Ryu, Changkook; Lee, Young Han; Hashimoto, Yohey; Huang, Longbin; Kwon, Eilhann E; Ok, Yong Sik; Lee, Sang Soo

    2017-06-01

    This study evaluated the feasibility of using biochars produced from three types of crop residues for immobilizing Pb and As and their effects on the abundance of microbial community in contaminated lowland paddy (P-soil) and upland (U-soil) agricultural soils. Biochars were produced from umbrella tree [Maesopsis eminii] wood bark [WB], cocopeat [CP], and palm kernel shell [PKS] at 500 °C by slow pyrolysis at a heating rate of 10 °C min -1 . Soils were incubated with 5% (w w -1 ) biochars at 25 °C and 70% water holding capacity for 45 d. The biochar effects on metal immobilization were evaluated by sequential extraction of the treated soil, and the microbial community was determined by microbial fatty acid profiles and dehydrogenase activity. The addition of WB caused the largest decrease in Pb in the exchangeable fraction (P-soil: 77.7%, U-soil: 91.5%), followed by CP (P-soil: 67.1%, U-soil: 81.1%) and PKS (P-soil: 9.1%, U-soil: 20.0%) compared to that by the control. In contrast, the additions of WB and CP increased the exchangeable As in U-soil by 84.6% and 14.8%, respectively. Alkalinity and high phosphorous content of biochars might be attributed to the Pb immobilization and As mobilization, respectively. The silicon content in biochars is also an influencing factor in increasing the As mobility. However, no considerable effects of biochars on the microbial community abundance and dehydrogenase activity were found in both soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Immobilization of Tyrosinase on (3-Aminopropyltriethoxysilane-Functionalized Carbon Felt-Based Flow-Through Detectors for Electrochemical Detection of Phenolic Compounds

    Directory of Open Access Journals (Sweden)

    Zheng Zhou

    2017-07-01

    Full Text Available Tyrosinase (TYR was covalently immobilized onto amino-functionalized carbon felt (CF surface via glutaraldehyde (GA. Prior to the TYR-immobilization, primary amino group was introduced to the CF surface by treatment with 3-aminopropyltriethoxysilane (APTES. The resulting TYR-immobilized CF was used as a working electrode unit of an electrochemical flow-through detector for mono- and di-phenolic compounds (i.e., catechol, p-cresol, phenol and p-chlorophenol. Additionally, flow injection peaks based on electroreduction of the enzymatically produced o-quinone species were detected at −0.05 V vs. Ag/AgCl. The resulting TYR/GA/APTES/CF biosensor responded well to all compounds tested with limits of detection range from 7.5 to 35 nmol−1 (based on three times S/N ratio. Moreover, such modified electrode exhibits good stability and reproducibility for catechol. No serious degradation of the peak current was found over 30 consecutive injections.

  20. Stereo-selective hydrolytic reaction of toxic compounds by enzyme immobilized on porous ceramics; Takoshitsu ceramics kotaika koso ni yoru dokusei kagobutsu no rittai sentakuteki kasui bunkai hanno

    Energy Technology Data Exchange (ETDEWEB)

    Kato, K.; Saito, T. [National Industrial Research Institute of Nagoya, Nagoya (Japan)

    2000-08-25

    Experiment was made on stereo-selective hydrolytic reaction of trifluoroethyl ester of ketoprophene by various kinds of lipase. In addition, study was made on the stability of lipase simply immobilized on porous ceramics under the existence of organic solvent. In the experiment, the hydrolytic activity of 8 kinds of lipase was studied for ketoprophene monochloroethyl ester (1a) and trifluoroethyl ester (1b). The experiment result showed that lipase M originating in mold (Mucor Javanicus) shows a high reactivity and stereo-selectivity for the compound (1a). The lipase immobilized on porous ceramics was easily obtained by a very simple method composed of only throwing carriers into enzyme suspension, agitation and refrigerated drying. The lipase immobilized on porous ceramics 'Toyonite 200-A' synthesized from kaolinite retained the residual activity of nearly 50%, original selectivity and considerable stability after 5 times of repetitive uses. This study result is useful for bio- reactors and bio-sensors for synthesis or decomposition of compounds. (NEDO)

  1. Sythesis of rare earth metal - GIC graphite intercalation compound in molten chloride system

    International Nuclear Information System (INIS)

    Ito, Masafumi; Hagiwara, Rika; Ito, Yasuhiko

    1994-01-01

    Graphite intercalation compounds of ytterbium and neodymium have been prepared by interacting graphite and metals in molten chlorides. These rare earth metals can be suspended in molten chlorides in the presence of trichlorides via disproportionation reaction RE(0) + RE(III) = 2RE(II) at lower than 300 degC. Carbides-free compounds are obtained in these systems. (author)

  2. Synthesis of graphite intercalation compound of group VI metals and uranium hexafluorides

    International Nuclear Information System (INIS)

    Fukui, Toshihiro; Hagiwara, Rika; Ema, Keiko; Ito, Yasuhiko

    1993-01-01

    Systematic investigations were made on the synthesis of graphite intercalation compounds of group VI transition metals (W and Mo) and uranium hexafluorides. The reactions were performed by interacting liquid or gaseous metal hexafluorides with or without elemental fluorine at ambient temperature. The degree of intercalation of these metal fluorides depends on the formation enthalpy of fluorometallate anion from the original metal hexafluoride, as has been found for other intercalation reactions of metal fluorides. (author)

  3. Biochar- and phosphate-induced immobilization of heavy metals in contaminated soil and water: implication on simultaneous remediation of contaminated soil and groundwater.

    Science.gov (United States)

    Liang, Yuan; Cao, Xinde; Zhao, Ling; Arellano, Eduardo

    2014-03-01

    Long-term wastewater irrigation or solid waste disposal has resulted in the heavy metal contamination in both soil and groundwater. It is often separately implemented for remediation of contaminated soil or groundwater at a specific site. The main objective of this study was to demonstrate the hypothesis of simultaneous remediation of both heavy metal contaminated soil and groundwater by integrating the chemical immobilization and pump-and-treat methods. To accomplish the objective, three experiments were conducted, i.e., an incubation experiment was first conducted to determine how dairy-manure-derived biochar and phosphate rock tailing induced immobilization of Cd in the Cd-contaminated soils; second, a batch sorption experiment was carried out to determine whether the pre-amended contaminated soil still had the ability to retain Pb, Zn and Cd from aqueous solution. BCR sequential extraction as well as XRD and SEM analysis were conducted to explore the possible retention mechanism; and last, a laboratory-scale model test was undertaken by leaching the Pb, Zn, and Cd contaminated groundwater through the pre-amended contaminated soils to demonstrate how the heavy metals in both contaminated soil and groundwater were simultaneously retained and immobilized. The incubation experiment showed that the phosphate biochar were effective in immobilizing soil Cd with Cd concentration in TCLP (toxicity characteristics leaching procedure) extract reduced by 19.6 % and 13.7 %, respectively. The batch sorption experiment revealed that the pre-amended soil still had ability to retain Pb, Zn, and Cd from aqueous solution. The phosphate-induced metal retention was mainly due to the metal-phosphate precipitation, while both sorption and precipitation were responsible for the metal stabilization in the biochar amendment. The laboratory-scale test demonstrated that the soil amended with phosphate removed groundwater Pb, Zn, and Cd by 96.4 %, 44.6 %, and 49.2 %, respectively, and the

  4. Biosynthesis of Multicomponent Nanoparticles with Extract of Mortiño (Vaccinium floribundum Kunth Berry: Application on Heavy Metals Removal from Water and Immobilization in Soils

    Directory of Open Access Journals (Sweden)

    Mayra Abril

    2018-01-01

    Full Text Available Through preparation of multicomponent nanoparticles (MCNPs using ferric chloride (FeCl3, sodium sulfate (Na2SO4, and the extract of mortiño fruit (Vaccinium floribundum Kunth, we dramatically improved the removal/immobilization of heavy metals from water and in soils. As-prepared nanoparticles were spherical measuring approximately 12 nm in diameter and contained iron oxides and iron sulfides in the crystal structure. Removal of copper and zinc from water using MCNPs showed high efficiencies (>99% at pH above 6 and a ratio of 0.5 mL of the extract:10 mL 0.5 M FeCl3·6H2O : 10 mL 0.035 M Na2SO4. The physisorption process followed by chemisorption was regarded as the removal mechanism of Cu and Zn from water. While, when MCNPs were used to treat soils contaminated with heavy metals, more than 95% of immobilization was accomplished for all metals. Nevertheless, the distribution of the metallic elements changed in the soil fractions after treatment. Results indicate that immobilization of metals after the injection of nanoparticles into soils was effective. Metals did not leach out when soils were drained with rain, drinking, and deionized water but fairly leached out under acidic water drainage.

  5. Remediation of Heavy Metal(loid)s Contaminated Soils – To Mobilize or To Immobilize?

    Science.gov (United States)

    Unlike organic contaminants, metal(loid)s do not undergo microbial or chemical degradation and persist for a long time after their introduction. Bioavailability of metal(loid)s plays a vital role in the remediation of contaminated soils. In this review, the remediation of heavy ...

  6. Heavy metal pollution in immobile and mobile components of lentic ecosystems-a review.

    Science.gov (United States)

    Meena, Ramakrishnan Anu Alias; Sathishkumar, Palanivel; Ameen, Fuad; Yusoff, Abdull Rahim Mohd; Gu, Feng Long

    2018-02-01

    With growing population and urbanization, there is an increasing exploitation of natural resources, and this often results to environmental pollution. In this review, the levels of heavy metal in lentic compartments (water, sediment, fishes, and aquatic plants) over the past two decades (1997-2017) have been summarized to evaluate the current pollution status of this ecosystem. In all the compartments, the heavy metals dominated are zinc followed by iron. The major reason could be area mineralogy and lithogenic sources. Enormous quantity of metals like iron in estuarine sediment is a very natural incident due to the permanently reducing condition of organic substances. Contamination of cadmium, lead, and chromium was closely associated with anthropogenic origin. In addition, surrounding land use and atmospheric deposition could have been responsible for substantial pollution. The accumulation of heavy metals in fishes and aquatic plants is the result of time-dependent deposition in lentic ecosystems. Moreover, various potential risk assessment methods for heavy metals were discussed. This review concludes that natural phenomena dominate the accumulation of essential heavy metals in lentic ecosystems compared to anthropogenic sources. Amongst other recent reviews on heavy metals from other parts of the world, the present review is executed in such a way that it explains the presence of heavy metals not only in water environment, but also in the whole of the lentic system comprising sediment, fishes, and aquatic plants.

  7. Immobilization of surface active compounds on polymer supports using glow discharge processess. 1. Sodium dodecyl sulfate on poly(propylene)

    NARCIS (Netherlands)

    Terlingen, J.G.A.; Terlingen, Johannes G.A.; Feijen, Jan; Hoffman, Allan S.

    1993-01-01

    A new method has been developed in which a reversibly adsorbed layer of a surfactant (sodium dodecyl sulfate, SDS) is covalently immobilized in one step onto a hydrophobic substrate (poly(propylene), PP) by applying an argon plasma treatment. The adsorption of SDS from aqueous solutions onto PP

  8. Optimizing the sensitivity and radiological properties of the PRESAGE® dosimeter using metal compounds

    International Nuclear Information System (INIS)

    Alqathami, Mamdooh; Blencowe, Anton; Qiao, Greg; Adamovics, John; Geso, Moshi

    2012-01-01

    The aim of this study is to investigate the radiation-modifying effects of incorporating commercially available bismuth-, tin- and zinc-based compounds in the composition of the PRESAGE ® dosimeter, and the feasibility of employing such compounds for radiation dose enhancement. Furthermore, we demonstrate that metal compounds can be included in the formulation to yield water-equivalent PRESAGE ® dosimeters with enhanced dose response. Various concentrations of the metal compounds were added to a newly developed PRESAGE ® formulation and the resulting dosimeters were irradiated with 100 kV and 6 MV photon beams. A comparison between sensitivity and radiological properties of the PRESAGE ® dosimeters with and without the addition of metal compounds was carried out. Optical density changes of the dosimeters before and after irradiation were measured using a spectrophotometer. In general, when metal compounds were incorporated in the composition of the PRESAGE ® dosimeter, the sensitivity of the dosimeters to radiation dose increased depending on the type and concentration of the metal compound, with the bismuth compound showing the highest dose enhancement factor. In addition, these metal compounds were also shown to improve the retention of the post-response absorption value of the PRESAGE ® dosimeter over a period of 2 weeks. Thus, incorporating 1–3 mM (ca. 0.2 wt%) of any of the three investigated metal compounds in the composition of the PRESAGE ® dosimeter is found to be an efficient way to enhance the sensitivity of the dosimeter to radiation dose and stabilize its post-response for longer times. Furthermore, the addition of small amounts of the metal compounds also accelerates the polymerization of the PRESAGE ® dosimeter precursors, significantly reducing the fabrication time. Finally, a novel water-equivalent PRESAGE ® dosimeter formula optimized with metal compounds is proposed for clinical use in both kilovoltage and megavoltage radiotherapy

  9. Heavy metal immobilization via microbially induced carbonate precipitation and co-precipitation

    Science.gov (United States)

    Lauchnor, E. G.; Stoick, E.

    2017-12-01

    Microbially induced CaCO3 precipitation (MICP) has been successfully used in applications such as porous media consolidation and sealing of leakage pathways in the subsurface, and it has the potential to be used for remediation of metal and radionuclide contaminants in surface and groundwater. In this work, MICP is investigated for removal of dissolved heavy metals from contaminated mine discharge water via co-precipitation in CaCO3 or formation of other metal carbonates. The bacterially catalyzed hydrolysis of urea produces inorganic carbon and ammonium and increases pH and the saturation index of carbonate minerals to promote precipitation of CaCO3. Other heavy metal cations can be co-precipitated in CaCO3 as impurities or by replacing Ca2+ in the crystal lattice. We performed laboratory batch experiments of MICP in alkaline mine drainage sampled from an abandoned mine site in Montana and containing a mixture of heavy metals at near neutral pH. Both a model bacterium, Sporosarcina pasteurii, and a ureolytic bacterium isolated from sediments on the mine site were used to promote MICP. Removal of dissolved metals from the aqueous phase was determined via inductively coupled plasma mass spectrometry and resulting precipitates were analyzed via electron microscopy and energy dispersive x-ray spectroscopy (EDX). Both S. pasteurii and the native ureolytic isolate demonstrated ureolysis, increased the pH and promoted precipitation of CaCO3 in batch tests. MICP by the native bacterium reduced concentrations of the heavy metals zinc, copper, cadmium, nickel and manganese in the water. S. pasteurii was also able to promote MICP, but with less removal of dissolved metals. Analysis of precipitates revealed calcium carbonate and phosphate minerals were likely present. The native isolate is undergoing identification via 16S DNA sequencing. Ongoing work will evaluate biofilm formation and MICP by the isolate in continuous flow, gravel-filled laboratory columns. This research

  10. Hemin immobilized into metal-organic frameworks as an electrochemical biosensor for 2,4,6-trichlorophenol

    Science.gov (United States)

    Zhang, Ting; Wang, Lu; Gao, Congwei; Zhao, Chaoyue; Wang, Yang; Wang, Jianmin

    2018-02-01

    Hemin immobilized into copper-based metal-organic frameworks was successfully prepared and used as a new electrode material for sensitive electrochemical biosensing. X-ray diffraction patterns, Fourier transform infrared spectra, scanning electron microscopy, UV-vis absorption spectroscopy, and cyclic voltammetry were used to characterize the resultant composites. Due to the interaction between the copper atom groups and hemin, the constrained environment in Cu-MOF-74 acts as a matrix to avoid the dimerization of enzyme molecules and retain its biological activity. The hemin/Cu-MOF composites demonstrated enhanced electrocatalytical activity and high stability towards the oxidation of 2,4,6-trichlorophenol. Under optimum experimental conditions, the sensor showed a wide linear relationship over the range of 0.01-9 μmol L-1 with a detection limit (3σ) of 0.005 μmol L-1. The relative standard deviations were 4.6% and 3.5% for five repeated measurements of 0.5 and 5 μmol L-1 2,4,6-trichlorophenol, respectively. The detection platforms for 2,4,6-trichlorophenol developed here not only indicate that hemin/Cu-MOF-74 possesses intrinsic biological reactivity, but also enable further work to be conducted towards the application of enzyme-containing metal-organic frameworks in electrochemical biosensors.

  11. Immobilized Metal Affinity Chromatography Co-Purifies TGF-β1 with Histidine-Tagged Recombinant Extracellular Proteins

    Science.gov (United States)

    Kaur, Jasvir; Reinhardt, Dieter P.

    2012-01-01

    Extracellular recombinant proteins are commonly produced using HEK293 cells as histidine-tagged proteins facilitating purification by immobilized metal affinity chromatography (IMAC). Based on gel analyses, this one-step purification typically produces proteins of high purity. Here, we analyzed the presence of TGF-β1 in such IMAC purifications using recombinant extracellular fibrillin-1 fragments as examples. Analysis of various purified recombinant fibrillin-1 fragments by ELISA consistently revealed the presence of picomolar concentrations of active and latent TGF-β1, but not of BMP-2. These quantities of TGF-β1 were not detectable by Western blotting and mass spectrometry. However, the amounts of TGF-β1 were sufficient to consistently trigger Smad2 phosphorylation in fibroblasts. The purification mechanism was analyzed to determine whether the presence of TGF-β1 in these protein preparations represents a specific or non-specific co-purification of TGF-β1 with fibrillin-1 fragments. Control purifications using conditioned medium from non-transfected 293 cells yielded similar amounts of TGF-β1 after IMAC. IMAC of purified TGF-β1 and the latency associated peptide showed that these proteins bound to the immobilized nickel ions. These data clearly demonstrate that TGF-β1 was co-purified by specific interactions with nickel, and not by specific interactions with fibrillin-1 fragments. Among various chromatographic methods tested for their ability to eliminate TGF-β1 from fibrillin-1 preparations, gel filtration under high salt conditions was highly effective. As various recombinant extracellular proteins purified in this fashion are frequently used for experiments that can be influenced by the presence of TGF-β1, these findings have far-reaching implications for the required chromatographic schemes and quality controls. PMID:23119075

  12. Immobilization of metal hexa-cyanoferrates in chitin beads for cesium sorption: synthesis and characterization

    International Nuclear Information System (INIS)

    Vincent, T.; Guibal, E.; Vincent, C.; Barre, Y.; Guari, Y.; Le Saout, G.

    2014-01-01

    Five metal-potassium hexacyanoferrate/chitin composites (based on Cu, Ni, Zn, Co or Fe co-metal) have been prepared and characterized, using SEM-EDX, TEM, X-ray diffraction and FT-IR, before being compared for Cs(I) and 137 Cs(I) sorption. The Zn-ion exchanger was characterized by a much larger crystal size of about 250 nm compared with a few tens of nm for other ion-exchangers. The ion exchangers are well distributed in the whole mass of the composite and they are fully accessible to Cs(I), as evidenced by Cs(I) distribution after metal sorption. Uptake kinetics can be modeled using both the pseudo-second order rate equation and the Crank equation (resistance to intra-particle diffusion coefficient). Sorption isotherms showed substantial differences in the sorbents that can be ranked as Cu ≥ Ni ≥ Zn ≥ Co ≥ Fe. However, based on 137 Cs K d values, the sorbents can be ranked as Co≥≥Fe≥≥Cu≥≥Ni≥Zn. Taking into account the cost and toxicity of metals (both in terms of manufacturing and potential metal release) a Prussian Blue based sorbent (i.e., iron-potassium hexacyanoferrate/chitin composite) sounds to be a good composite for Cs(I) recovery from radionuclide-containing effluents. (authors)

  13. Effects of Biochar-Derived Sewage Sludge on Heavy Metal Adsorption and Immobilization in Soils

    Science.gov (United States)

    Zhou, Dan; Liu, Dan; Gao, Fengxiang; Li, Mengke; Luo, Xianping

    2017-01-01

    The object of this study was to evaluate the effect of sewage sludge biochar on adsorption and mobility of Cr, Mn, Cu, and Zn. Biochar (BC400) was produced via pyrolysis of municipal sewage sludge at 400 °C. Maximum adsorption capacities (qm) for Zn, Cr, Mn, and Cu were 5.905, 5.724, 5.681, and 5.342 mg·g−1, respectively, in the mono-metal solution and 2.475, 8.204, 1.01, and 5.415 mg·g−1, respectively, in the multi-metal solution. The adsorption capacities for Mn, Cu, and Zn decreased in the multi-metal solution due to competitive adsorption, whereas the capacity for Cr increased. Surface precipitation is an important mechanism in the sorption of these metals on BC400. The 360-day incubation experiment showed that BC400 application reduced metal mobility in contaminated soils, which was attributed to the substantial decreases in the acid-soluble fractions of Cr, Mn, Cu, and Zn (72.20%, 70.38%, 50.43%, and 29.78%, respectively). Furthermore, the leaching experiment using simulated acid rain indicated that the addition of BC400 enhanced the acid buffer capacity of contaminated soil, and the concentration of Cr, Mn, Cu, and Zn in the leachate was lower than in untreated soil. Overall, this study indicates that sewage sludge biochar application reduces the mobility of heavy metal in co-contaminated soil, and this adsorption experiment is suitable for the evaluation of biochar properties for remediation. PMID:28644399

  14. Effects of Biochar-Derived Sewage Sludge on Heavy Metal Adsorption and Immobilization in Soils.

    Science.gov (United States)

    Zhou, Dan; Liu, Dan; Gao, Fengxiang; Li, Mengke; Luo, Xianping

    2017-06-23

    The object of this study was to evaluate the effect of sewage sludge biochar on adsorption and mobility of Cr, Mn, Cu, and Zn. Biochar (BC400) was produced via pyrolysis of municipal sewage sludge at 400 °C. Maximum adsorption capacities ( q m ) for Zn, Cr, Mn, and Cu were 5.905, 5.724, 5.681, and 5.342 mg·g -1 , respectively, in the mono-metal solution and 2.475, 8.204, 1.01, and 5.415 mg·g -1 , respectively, in the multi-metal solution. The adsorption capacities for Mn, Cu, and Zn decreased in the multi-metal solution due to competitive adsorption, whereas the capacity for Cr increased. Surface precipitation is an important mechanism in the sorption of these metals on BC400. The 360-day incubation experiment showed that BC400 application reduced metal mobility in contaminated soils, which was attributed to the substantial decreases in the acid-soluble fractions of Cr, Mn, Cu, and Zn (72.20%, 70.38%, 50.43%, and 29.78%, respectively). Furthermore, the leaching experiment using simulated acid rain indicated that the addition of BC400 enhanced the acid buffer capacity of contaminated soil, and the concentration of Cr, Mn, Cu, and Zn in the leachate was lower than in untreated soil. Overall, this study indicates that sewage sludge biochar application reduces the mobility of heavy metal in co-contaminated soil, and this adsorption experiment is suitable for the evaluation of biochar properties for remediation.

  15. Studies about interaction of hydrogen isotopes with metals and intermetallic compounds

    International Nuclear Information System (INIS)

    Vasut, F.; Anisoara, P.; Zamfirache, M.

    2003-01-01

    Hydrogen is a non-toxic but highly inflammable gas. Compared to other inflammable gases, its range of inflammability in air is much broader (4-74.5%) but it also vaporizes much more easily. Handling of hydrogen in form of hydrides enhances safety. The interaction of hydrogen with metals and intermetallic compounds is a major field within physical chemistry. Using hydride-forming metals and intermetallic compounds, for example, recovery, purification and storage of heavy isotopes in tritium containing system can solve many problems arising in the nuclear-fuel cycle. The paper presents the thermodynamics and the kinetics between hydrogen and metal or intermetallic compounds. (author)

  16. Direct electrochemical sensing of glucose using glucose oxidase immobilized on functionalized carbon nanotubes via a novel metal chelate-based affinity method

    International Nuclear Information System (INIS)

    Tu, X.; Zhao, Y.; Luo, S.; Luo, X.; Feng, L.

    2012-01-01

    We report on a novel amperometric glassy carbon biosensing electrode for glucose. It is based on the immobilization of a highly sensitive glucose oxidase (GOx) by affinity interaction on carbon nanotubes (CNTs) functionalized with iminodiacetic acid and metal chelates. The new technique for immobilization is exploiting the affinity of Co(II) ions to the histidine and cysteine moieties on the surface of GOx. The direct electrochemistry of immobilized GOx revealed that the functionalized CNTs greatly improve the direct electron transfer between GOx and the surface of the electrode to give a pair of well-defined and almost reversible redox peaks and undergoes fast heterogeneous electron transfer with a rate constant (k s) of 0. 59 s -1 . The GOx immobilized in this way fully retained its activity for the oxidation of glucose. The resulting biosensor is capable of detecting glucose at levels as low as 0.01 mM, and has excellent operational stability (with no decrease in the activity of enzyme over a 10 days period). The method of immobilizing GOx is easy and also provides a model technique for potential use with other redox enzymes and proteins. (author)

  17. Immobilization of metal wastes by reaction with H2S in anoxic basins. Concept and Elaboration

    NARCIS (Netherlands)

    Schuiling, R.D.

    2013-01-01

    Metal wastes are produced in large quantities by a number of industries. Their disposal in isolated waste deposits is certain to cause many subsequent problems, because every material will sooner or later return to the geochemical cycle. The sealing of disposal sites usually starts to

  18. IMMOBILIZATION OF HEAVY METALS IN SOILS AND WATER BY A MANGANESE MINERAL

    Science.gov (United States)

    A synthesized Mn mineral used in study on adsorption of heavy metals from water has shown a great adsorption capability for Pb, Cu, Cd, Co, Ni and Zn on this mineral over a pH range from 2 to 8. The retention of Pb on this mineral was as high as 10% of its weight. Application of ...

  19. The enhancement of the hydrolysis of bamboo biomass in ionic liquid with chitosan-based solid acid catalysts immobilized with metal ions.

    Science.gov (United States)

    Cheng, Jie; Wang, Nan; Zhao, Dezhou; Qin, Dandan; Si, Wenqing; Tan, Yunfei; Wei, Shun'an; Wang, Dan

    2016-11-01

    Three kinds of sulfonated cross-linked chitosan (SCCR) immobilized with metal ions of Cu(2+), Fe(3+) and Zn(2+) individually were synthesized and firstly used as solid acid catalysts in the hydrolysis of bamboo biomass. FTIR spectra showed that metal ions had been introduced into SCCR and the N-metal ions coordinate bound was formed. The particle sizes of these catalysts were about 500-1000μm with a pore size of 50-160μm. All of the three kinds of catalysts performed well for bamboo hydrolysis with 1-butyl-3-methyl-imidazolium chloride used as solvent. The most effective one was sulfonated cross-linked chitosan immobilized with Fe(3+) (Fe(3+)-SCCR). TRS yields were up to 73.42% for hydrolysis of bamboo powder in [C4mim]Cl with Fe(3+)-SCCR at 120°C and 20RPM after 24h. These novel chitosan-based metal ions immobilized solid acid catalysts with ionic liquids as the solvent might be promising to facilitate cost-efficient conversion of biomass into biofuels and bioproducts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Application of Local Adsorbant From Southeast Sulawesi Clay Immobilized Saccharomyces Cerevisiae Bread’s Yeast Biomass for Adsorption Of Mn(Ii) Metal Ion

    Science.gov (United States)

    R, Halimahtussaddiyah; Mashuni; Budiarni

    2017-05-01

    Southeast Sulawesi has a great stock of clay. It is probably to use as a source of adsorbent. The adsorbent capacity of clay can be largered with teratment using bread’s yeast as biomass. At this research, study of analysis adsorption of Mn(II) metal ion on clay immobilized Saccharomyces cerevisiae bread’s yeast biomass adsorbent has been conducted. The aims of this research were to determine the effects of contact time, pH and concentration of Mn(II) metal ion and to determine the adsorption capacity of clay immobilized S. cerevisiae biomass for adsorbtion of Mn(II) metal ion. Activated clay was synthesized by reaction of clay with KMnO4, H2SO4 and HCl. S. cerevisiae biomass was result by bread’s yeast mashed. Immobilization of S. cerevisiae biomass into clay was done by mixing of ratio of S. cerevisiae bread’s yeast biomass and clay equal to 1:3 (mass of biomassa : mass of clay). The adsorption capacity was determined by using Freundlich and Langmuir adsorption isoterms. The results of FTIR spectrums showed that the functional groups of clay immobilized S. cerevisiae biomass were Si-OH (wave number 1643 cm-1), Si-O-Si (wave number 1033 cm-1), N-H (wave number 2337 cm-1), O-H (wave number 3441cm-1), and C-H (wave number 2931 cm-1). The result of adsorption capacity from Mn(II) metal ion of contact time optimum 120 minutes, pH optimun at 7 and concentration optimum 50 mg/L were 1,816 mg/g; 0,509 mg/g and 2,624mg/g respectively. The adsorption capacity of Mn(II) metal ion with ratio 1:3 (biomass : clay) was 0,1045 mg/g. Type of isothermal adsorption followed the Freunlich adsorption.

  1. Catalytic olefin polymerization with early transition metal compounds

    NARCIS (Netherlands)

    Eshuis, Johan Jan Willem

    1991-01-01

    The catalysis of organic reactions by soluble metal complexes has become a major tool in synthesis, both in the laboratory and in the chemical industry. Processes catalyzed by transition metal complexes include carbonylation, olefin polymerization, olefin addition, olefin oxidation and alkane and

  2. Grenade Range Management Using Lime for Dual Role of Metals Immobilization and Explosives Transformation Treatability

    Science.gov (United States)

    2006-11-01

    Development and Engineering Command, Armament Research, Development and Engineering Center, Picatinny Arsenal , NJ 07806-5000 1. ABSTRACT: The importance...2001) and the FRTR (2006) are enhanced bioremediation and phytoremediation . The length of time and the effects of climate on cleanup are...cementitious reaction that stabilizes the metals in the soil. They found that lead, arsenic , mercury, and iron concentrations were very low in the leachate

  3. Effect of amendments on chemical immobilization of heavy metals in sugar mill contaminated soils

    Directory of Open Access Journals (Sweden)

    Mohammad Jamal Khan, Muhammad Tahir Azeem and Sajida Perveen1

    2012-05-01

    Full Text Available A bulk soil sample collected from the vicinity of PSM (Premier Sugar Mill Mardan was amended with diammonium phosphate (DAP, triple super phosphate (TSP, Farm Yard Manure (FYM and poultry manure (PM in 1.5 kg soil in a 2 L plastic pot. Both DAP and TSP were added at 230 mg kg 1 (460 kg ha 1 soil whereas the organic amendments (FYM and PM were added at the rate of 10% by weight of soil. The air dried samples in pots were brought to field moisture content (0.33 bar water content by the addition of either HIE (Hayatabad Industrial Estate or PSM in two separate sets of experiments. The experimental pots were arranged in randomized complete design with three replicates under laboratory conditions during March to May (Temperature varying between 25 to 30 °C. Treated and control pots were incubated for 90 days al 0.33 bar ca 25% moisture and the moisture deficit during the incubation time was adjusted by adding PSM and HIE effluents in their respective set of experimental pots. Soil samples were collected after 15, 30, 45 and 90 d to determine the effect of amendments on AB-DTPA extractable metals. The results showed that AB-DTPA extractable Cd, Or, Cu, Ni and Cd increased significantly with lime and the maximum values were noted after 90 days incubation whereas the Fe, Mn and Zn content in soil increased with time but the increase was not significant. It was further noted that the increase over time in metal was not pronounced when supplied with amendments indicating their ability to chemically stabilize it compared to unamended soils. Higher values of all the heavy metals were noted in unamended soil. By comparing the different amendments, it was observed that FYM was effective in reducing the extractability/phytoavailability of all the metals under study except Pb whereby DAP was most effective as a stabilizing agent in the soil. It was concluded that in calcareous soil, FYM and DAP can be used to reduce the risk of phytotoxicity of heavy metals in

  4. On the valence state of Yb and Ce in transition metal intermetallic compounds

    International Nuclear Information System (INIS)

    Boer, F.R. de; Dijkman, W.H.; Mattens, W.C.M.

    1979-01-01

    In the pure state Yb is a divalent metal, similar to Ca; in alloys it can become trivalent like the majority of the rare earth metals. Using a value of 38 kJ (mol Yb) -1 for the energy difference between divalent and trivalent Yb metal and using model calculations for the heat of formation of intermetallic compounds, the authors are able to account for the existing information on the valence state of Yb in transition metal compounds. A similar analysis of compounds of Ce with transition metals shows that a model in which the 4f electron is treated as a core electron, i.e. being absent in the tetravalent modification of Ce and present as a fully localized electron in trivalent Ce, does not apply. (Auth.)

  5. Fast gradient HPLC method to determine compounds binding to human serum albumin. Relationships with octanol/water and immobilized artificial membrane lipophilicity.

    Science.gov (United States)

    Valko, Klara; Nunhuck, Shenaz; Bevan, Chris; Abraham, Michael H; Reynolds, Derek P

    2003-11-01

    A fast gradient HPLC method (cycle time 15 min) has been developed to determine Human Serum Albumin (HSA) binding of discovery compounds using chemically bonded protein stationary phases. The HSA binding values were derived from the gradient retention times that were converted to the logarithm of the equilibrium constants (logK HSA) using data from a calibration set of molecules. The method has been validated using literature plasma protein binding data of 68 known drug molecules. The method is fully automated, and has been used for lead optimization in more than 20 company projects. The HSA binding data obtained for more than 4000 compounds were suitable to set up global and project specific quantitative structure binding relationships that helped compound design in early drug discovery. The obtained HSA binding of known drug molecules were compared to the Immobilized Artificial Membrane binding data (CHI IAM) obtained by our previously described HPLC-based method. The solvation equation approach has been used to characterize the normal binding ability of HSA, and this relationship shows that compound lipophilicity is a significant factor. It was found that the selectivity of the "baseline" lipophilicity governing HSA binding, membrane interaction, and octanol/water partition are very similar. However, the effect of the presence of positive or negative charges have very different effects. It was found that negatively charged compounds bind more strongly to HSA than it would be expected from the lipophilicity of the ionized species at pH 7.4. Several compounds showed stronger HSA binding than can be expected from their lipophilicity alone, and comparison between predicted and experimental binding affinity allows the identification of compounds that have good complementarities with any of the known binding sites. Copyright 2003 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 92:2236-2248, 2003

  6. Choice of materials for the immobilization of 85-krypton in a metallic matrix by combined ion implantation and sputtering

    International Nuclear Information System (INIS)

    Whitmell, D.S.

    1985-01-01

    Immobilization in a metal matrix by combined ion implantation and sputtering promises to offer an ideal method for the containment of krypton-85 arising from the reprocessing of nuclear fuel. A 50 kW inactive pilot plant has been built and operated to prepare a copper deposit 22 mm thick weighing 23 kg and containing over 30 liters of inactive gas. The gas incorporation rate exceeded the design figure of 0.3 liters/hour and the vessel was operated at powers up to 30 kW, which corresponds to that envisaged for the industrial vessel. The power consumption was less than 100 kWh/liter. A full-scale vessel (1 m long, 0.26 m diameter) has also been tested at low power. Samples of alternative candidate materials: stainless steel, incoloy, nickel and nickel-lanthanum have been prepared and tested. Nickel appears to be the most promising since it incorporates gas with an efficiency 70% greater than copper and also retains the gas to a temperature at least 100 0 C higher than copper. Tests are being carried out with 100 Curies of radioactive krypton in order to demonstrate that the process will operate satisfactorily at the high internal β irradiation levels that will exist in an active plant and to prepare samples containing krypton-85 for long term leakage measurements and for assessment of any effects caused by the build-up of the decay product rubidium

  7. studies on transition metal complexes of herbicidal compounds. ii

    African Journals Online (AJOL)

    a

    derivative of 2-chloro-4-ethylamino-6-isopropylamino-s-triazine, atrazine (ATZ) --- a well known herbicide has ... development while the other is the metal ion associated degradation or deactivation of the herbicides .... Colour M.p./decomp.

  8. Engineered Natural Geosorbents for In Situ Immobilization of DNAPLs and Heavy Metals

    Energy Technology Data Exchange (ETDEWEB)

    Walter J. Weber; Gordon M. Fair; Earnest Boyce

    2006-12-01

    Extensive subsurface contamination by dense non-aqueous phase liquid (DNAPL) organic solvents and heavy metals is common place at many DOE facilities. Poor performances and excessive costs have made traditional technologies and approaches less than satisfactory for remediation of such sites. It is increasingly apparent that marginal improvements in conventional methods and approaches will not suffice for clean up of many contaminated DOE sites. Innovative approaches using new and/or existing technologies in more efficient and cost-effective ways are thus urgently required.

  9. Engineered Natural Geosorbents for In Situ Immobilization of DNAPLs and Heavy Metals

    International Nuclear Information System (INIS)

    Walter J. Weber; Gordon M. Fair; Earnest Boyce

    2006-01-01

    Extensive subsurface contamination by dense non-aqueous phase liquid (DNAPL) organic solvents and heavy metals is common place at many DOE facilities. Poor performances and excessive costs have made traditional technologies and approaches less than satisfactory for remediation of such sites. It is increasingly apparent that marginal improvements in conventional methods and approaches will not suffice for clean up of many contaminated DOE sites. Innovative approaches using new and/or existing technologies in more efficient and cost-effective ways are thus urgently required

  10. Catalytic olefin polymerization with early transition metal compounds

    OpenAIRE

    Eshuis, Johan Jan Willem

    1991-01-01

    The catalysis of organic reactions by soluble metal complexes has become a major tool in synthesis, both in the laboratory and in the chemical industry. Processes catalyzed by transition metal complexes include carbonylation, olefin polymerization, olefin addition, olefin oxidation and alkane and arene oxidation. Traditionally, heterogeneous catalysts have been used for the production of large-scale commodity chemicals such as methanol and ammonia and in the production of high octane gasoline...

  11. Immobilization of radioactive strontium in contaminated soils by phosphate treatment

    International Nuclear Information System (INIS)

    Kim, K.H.; Ammons, J.T.

    1990-01-01

    The feasibility of in situ phosphate- and metal- (calcium, aluminum, and iron) solution treatment for 90 Sr immobilization was investigated. Batch and column experiments were performed to find optimum conditions for coprecipitation of 90 Sr with Ca-, Al-, and Fe-phosphate compounds in contaminated soils. Separate columns were packed with artificially 85 Sr-contaminated acid soil as well as 90 Sr-contaminated soil from the Oak Ridge Reservation. After metal-phosphate treatment, the columns were then leached successively with either tapwater or 0.001 M CaCl 2 solution. Most of the 85 Sr coprecipitated with the metal phosphate compounds. Immobilization of 85 Sr and 90 Sr was affected by such factors as solution pH, metal and phosphate concentration, metal-to-phosphate ratio, and soil characteristics. Equilibration time after treatments also affected 85 Sr immobilization. Many technology aspects still need to be investigated before field applications are feasible, but these experiments indicate that phosphate-based in situ immobilization should prevent groundwater contamination and will be useful as a treatment technology for 90 Sr-contaminated sites. 15 refs., 3 figs., 1 tab

  12. PEROXOTITANATE- AND MONOSODIUM METAL-TITANATE COMPOUNDS AS INHIBITORS OF BACTERIAL GROWTH

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D.

    2011-01-19

    Sodium titanates are ion-exchange materials that effectively bind a variety of metal ions over a wide pH range. Sodium titanates alone have no known adverse biological effects but metal-exchanged titanates (or metal titanates) can deliver metal ions to mammalian cells to alter cell processes in vitro. In this work, we test a hypothesis that metal-titanate compounds inhibit bacterial growth; demonstration of this principle is one prerequisite to developing metal-based, titanate-delivered antibacterial agents. Focusing initially on oral diseases, we exposed five species of oral bacteria to titanates for 24 h, with or without loading of Au(III), Pd(II), Pt(II), and Pt(IV), and measuring bacterial growth in planktonic assays through increases in optical density. In each experiment, bacterial growth was compared with control cultures of titanates or bacteria alone. We observed no suppression of bacterial growth by the sodium titanates alone, but significant (p < 0.05, two-sided t-tests) suppression was observed with metal-titanate compounds, particularly Au(III)-titanates, but with other metal titanates as well. Growth inhibition ranged from 15 to 100% depending on the metal ion and bacterial species involved. Furthermore, in specific cases, the titanates inhibited bacterial growth 5- to 375-fold versus metal ions alone, suggesting that titanates enhanced metal-bacteria interactions. This work supports further development of metal titanates as a novel class of antibacterials.

  13. Immobilization of metal-humic acid complexes in anaerobic granular sludge for their application as solid-phase redox mediators in the biotransformation of iopromide in UASB reactors.

    Science.gov (United States)

    Cruz-Zavala, Aracely S; Pat-Espadas, Aurora M; Rangel-Mendez, J Rene; Chazaro-Ruiz, Luis F; Ascacio-Valdes, Juan A; Aguilar, Cristobal N; Cervantes, Francisco J

    2016-05-01

    Metal-humic acid complexes were synthesized and immobilized by a granulation process in anaerobic sludge for their application as solid-phase redox mediators (RM) in the biotransformation of iopromide. Characterization of Ca- and Fe-humic acid complexes revealed electron accepting capacities of 0.472 and 0.556milli-equivalentsg(-1), respectively. Once immobilized, metal-humic acid complexes significantly increased the biotransformation of iopromide in upflow anaerobic sludge blanket (UASB) reactors. Control UASB reactor (without humic material) achieved 31.6% of iopromide removal, while 80% was removed in UASB reactors supplied with each metal-humic acid complex. Further analyses indicated multiple transformation reactions taking place in iopromide including deiodination, N-dealkylation, decarboxylation and deacetylation. This is the first successful application of immobilized RM, which does not require a supporting material to maintain the solid-phase RM in long term operation of bioreactors. The proposed redox catalyst could be suitable for enhancing the redox conversion of different recalcitrant pollutants present in industrial effluents. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. 50 years of superbases made from organolithium compounds and heavier alkali metal alkoxides

    Czech Academy of Sciences Publication Activity Database

    Lochmann, Lubomír; Janata, Miroslav

    2014-01-01

    Roč. 12, č. 5 (2014), s. 537-548 ISSN 1895-1066 R&D Projects: GA ČR GAP106/12/0844 Institutional support: RVO:61389013 Keywords : superbases * heavier alkali metal compounds * lithium -heavier alkali metal interchange Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.329, year: 2013

  15. Biosorption of heavy metals by immobilized microalgae; Biosorption von Schwermetallen durch immobilisierte Mikroalgen

    Energy Technology Data Exchange (ETDEWEB)

    Wilke, A.; Bunke, G.; Goetz, P.; Buchholz, R. [Technische Univ. Berlin (Germany). Fachgebiet Bioverfahrenstechnik

    1999-07-01

    Some microalgae stand out by the fact that they are highly capable of adsorbing heavy metals (biosorption). In contrast to bioaccumulation, where heavy metals are actively integrated into living cells, biosorption is a process of chemical-physical deposition to functional groups of the cell wall components. For a process-technological application, different reactor configurations may be used. Owing to different advantages such as a continuous mode of operation, attainable low effluent concentrations, low operating cost, ease of scaling up, modular design, modest space demand and a high degree of automation, packed-bed adsorption is the process-technological solution to be preferred. Mathematical modelling of adsorption kinetics as a basis for scaling up requires knowledge of resistances to suspended matter transport for the adsorbents used. By appropriate experiments the different resistances (film resistance, diffusion resistance inside particles) need to be decoupled from each other prior to their determination. (orig.) [German] Einige Mikroalgen zeichnen sich dadurch aus, im hohen Masse Schwermetalle zu adsorbieren (Biosorption). Im Gegensatz zur Bioakkumulation, bei der die Schwermetalle aktiv in die lebende Zelle aufgenommen werden, handelt es sich bei der Biosorption um einen chemischen/physikalischen Anlagerungsprozess an funktionelle Gruppen der Zellwandkomponenten. Fuer eine verfahrenstechnische Umsetzung koennen unterschiedliche Reaktorkonfigurationen verwendet werden. Aufgrund verschiedener Vorteile wie kontinuierliche Betriebsweise, niedrige erreichbare Ablaufkonzentration, geringe Betriebskosten, einfache Scale-up-Faehigkeit, modulare Bauweise, geringer Platzbedarf sowie hoher Automatisierungsgrad ist eine Festbettadsorption als verfahrenstechnische Loesung vorzuziehen. Eine mathematische Modellierung der Adsorptionskinetik, als Basis einer Massstabsvergroesserung, erfordert die Kenntnis der Stofftransportwiderstaende bei den verwendeten Adsorbentien

  16. Thorium-d-metals compounds and solid solutions

    International Nuclear Information System (INIS)

    Chachkhiani, Z.B.; Chechernikov, V.I.; Chachkhiani, L.G.

    1986-01-01

    Thorium compounds with Fe, Co, Ni dependence of their magnetic properties on temperature, pressure and concentration of the second element are considered. Anomalous magnetic behaviour of alloys in the Th-Fe system is noted. Special attention is paid to compounds with CaCu 5 type hexagonal structure and their solid solutions. Th-Co-Ni specimens containing up to 25% Ni are ferromagnetics and the rest are paramagnetics. Specimens with 60% cobalt content do not display ferromagnetic properties up to 4.2 K. Hydrides of Th 7 M 3 H 30 type (M - Fe, Co, Ni) are also considered. Highly hydrogenized specimens (under high pressure) appear to be stronger ferromagnetics

  17. Method of making metal oxide ceramic powders by using a combustible amino acid compound

    Science.gov (United States)

    Pederson, Larry R.; Chick, Lawrence A.; Exarhos, Gregory J.

    1992-01-01

    This invention is directed to the formation of homogeneous, aqueous precursor mixtures of at least one substantially soluble metal salt and a substantially soluble, combustible co-reactant compound, typically an amino acid. This produces, upon evaporation, a substantially homogeneous intermediate material having a total solids level which would support combustion. The homogeneous intermediate material essentially comprises highly dispersed or solvated metal constituents and the co-reactant compound. The intermediate material is quite flammable. A metal oxide powder results on ignition of the intermediate product which combusts same to produce the product powder.

  18. Electronic and thermodynamic properties of transition metal elements and compounds

    International Nuclear Information System (INIS)

    Haeglund, J.

    1993-01-01

    This thesis focuses on the use of band-structure calculations for studying thermodynamic properties of solids. We discuss 3d-, 4d- and 5d-transition metal carbides and nitrides. Through a detailed comparison between theoretical and experimental results, we draw conclusions on the character of the atomic bonds in these materials. We show how electronic structure calculations can be used to give accurate predictions for bonding energies. Part of the thesis is devoted to the application of the generalized gradient approximation in electronic structure calculations on transition metals. For structures with vibrational disorder, we present a method for calculating averaged phonon frequencies without using empirical information. For magnetic excitations, we show how a combined use of theoretical results and experimental data can yield information on magnetic fluctuations at high temperatures. The main results in the thesis are: Apart for an almost constant shift, theoretically calculated bonding energies for transition metal carbides and nitrides agree with experimental data or with values from analysis of thermochemical information. The electronic spectrum of transition metal carbides and nitrides can be separated into bonding, antibonding and nonbonding electronic states. The lowest enthalpy of formation for substoichiometric vanadium carbide VC 1-X at zero temperature and pressure occurs for a structure containing vacancies (x not equal to 0). The generalized gradient approximation improves theoretical calculated cohesive energies for 3d-transition metals. Magnetic phase transitions are sensitive to the description of exchange-correlation effects in electronic structure calculations. Trends in Debye temperatures can be successfully analysed in electronic structure calculations on disordered lattices. For the elements, there is a clear dependence on the crystal structure (e.g., bcc, fcc or hcp). Chromium has fluctuating local magnetic moments at temperatures well above

  19. Method and apparatus for dissociating metals from metal compounds extracted into supercritical fluids

    Science.gov (United States)

    Wai, Chien M.; Hunt, Fred H.; Smart, Neil G.; Lin, Yuehe

    2000-01-01

    A method for dissociating metal-ligand complexes in a supercritical fluid by treating the metal-ligand complex with heat and/or reducing or oxidizing agents is described. Once the metal-ligand complex is dissociated, the resulting metal and/or metal oxide form fine particles of substantially uniform size. In preferred embodiments, the solvent is supercritical carbon dioxide and the ligand is a .beta.-diketone such as hexafluoroacetylacetone or dibutyldiacetate. In other preferred embodiments, the metals in the metal-ligand complex are copper, silver, gold, tungsten, titanium, tantalum, tin, or mixtures thereof. In preferred embodiments, the reducing agent is hydrogen. The method provides an efficient process for dissociating metal-ligand complexes and produces easily-collected metal particles free from hydrocarbon solvent impurities. The ligand and the supercritical fluid can be regenerated to provide an economic, efficient process.

  20. Immobilization of heavy metals arising sludge galvanic, in glass ceramic material; Imobilizacao de metais pesados oriundos de lodo galvanico em material vitreo

    Energy Technology Data Exchange (ETDEWEB)

    Felisberto, R., E-mail: regina.felisberto@poa.ifrs.edu.br [Instituto Federal do Rio Grande do Sul (IFRS), Porto Alegre, RS (Brazil); Santos, M.C.; Basegio, T.; Bergmann, C.P. [Universidade Federal do Rio Grande do Sul (PPGEM/UFRGS), Porto Alegre, RS (Brazil)

    2016-07-01

    The use of galvanic sludge in the glass-ceramic formulation for immobilizing environmentally harmful materials is consolidated in more developed countries as raw material in the formulation of new materials. In this work, we have used galvanic sludge provided by a metallurgical company located in Vale dos Sinos, RS. The sludge was dried at 105°C and mixed with soda-lime glass in proportions of 1, 5, 10 and 20%, relative to the glass mass. Its composition was determined by FRX, and evaluated for leaching (NBR 10005) and solubilization (NBR 10006). The specimens (CPs) were burned at temperatures 750, 800 and 850°C, also submitted to the tests. The sludge, Class I - dangerous, presented Se content greater than provisions of NBR 10004. It was possible to immobilize the heavy metals at a temperature of 850°C for specimens of the F1 formulation, having been thus classified as Class II B Inert Residue. (author)

  1. Fermi surface measurements in actinide metals and compounds

    International Nuclear Information System (INIS)

    Arko, A.J.; Schirber, J.E.

    1978-01-01

    The various techniques of measuring Fermi Surface parameters are briefly discussed in terms f application to actinide systems. Particular emphasis is given the dHvA effect. Some general results found in the dHvA studies of actinide compounds are given. The dHvA effect has been measured in α-U and is presented in detail. None of the observed frequencies corresponds to closed surfaces. Results are compared to the calculations of Freeman, Koelling and Watson-Yang where qualitative agreement is observed

  2. Carbon based secondary compounds do not provide protection against heavy metal road pollutants in epiphytic macrolichens.

    Science.gov (United States)

    Gauslaa, Yngvar; Yemets, Olena A; Asplund, Johan; Solhaug, Knut Asbjørn

    2016-01-15

    Lichens are useful monitoring organisms for heavy metal pollution. They are high in carbon based secondary compounds (CBSCs) among which some may chelate heavy metals and thus increase metal accumulation. This study quantifies CBSCs in four epiphytic lichens transplanted for 6months on stands along transects from a highway in southern Norway to search for relationships between concentrations of heavy metals and CBSCs along a gradient in heavy metal pollutants. Viability parameters and concentrations of 21 elements including nutrients and heavy metals in these lichen samples were reported in a separate paper. Medullary CBSCs in fruticose lichens (Ramalina farinacea, Usnea dasypoga) were reduced in the most polluted sites, but not in foliose ones (Parmelia sulcata, Lobaria pulmonaria), whereas cortical CBSC did not change with distance from the road in any species. Strong positive correlations only occurred between the major medullary compound stictic acid present in L. pulmonaria and most heavy metals, consistent with a chelating role of stictic acid, but not of other studied CBSCs or in other species. However, heavy metal chelating did not protect L. pulmonaria against damage because this species experienced the strongest reduction in viability in the polluted sites. CBSCs with an accumulation potential for heavy metals should be quantified in lichen biomonitoring studies of heavy metals because they, like stictic acid, could overshadow pollutant inputs in some species rendering biomonitoring data less useful. In the two fruticose lichen species, CBSCs decreased with increasing heavy metal concentration, probably because heavy metal exposure impaired secondary metabolism. Thus, we found no support for a heavy metal protection role of any CBSCs in studied epiphytic lichens. No intraspecific relationships occurred between CBSCs versus N or C/N-ratio. Interspecifically, medullary CBSCs decreased and cortical CBSCs increased with increasing C/N-ratio. Copyright © 2015

  3. Bond ionicity in crystals of transition metal compounds

    International Nuclear Information System (INIS)

    Kesler, Ya.A.

    1989-01-01

    A unified method of calculating bond ionicity in inorganic crystals is suggested. The approach presented envisages the sealing of d-electron contribution to ξ,p-electron contribution for the retention of community which can only be implemented by a self-consistent procedure. The results of self-consistent calculations of bond parameters of a number of crystals (ScN, Sc 2 O 3 , In 2 O 3 , J 2 O 3 ) as compared with the data for ξ,p-analogues are given. Ionicity changes in the series of analogous compounds utterly correspond to existing chemical concepts. The data for oxides of 4d-, 5d-elements (ZrO 2 , CeO 2 , ThO 2 ) and for a number of ternary compounds containing two types of bonds (LiNbO 3 , CdSc 2 S 4 , CdCr 2 Se 4 etc) are also given. In the case of transition elements ionicity to a great extent depends on the symmetry of anion environment and correlates to orbital population well. Ionicity values are in direct proportion to effective charges of atoms of transition elements

  4. Crystalline and amorphous rare-earth metallic compounds

    International Nuclear Information System (INIS)

    Burzo, E.

    1975-01-01

    During the last years the study of magnetic behaviour of rare-earth (or yttrium) compounds with cobalt and iron has growth of interest. This interest of justified by a large area of experimental and theoretical problems coming into being in the study of some rare-earth materials as well as in their technical applications. In the last three years a great number of new rare earth materials were studied and also new models explaining the magnetic behaviour of these systems have been used. In this paper we refer especially to some typical systems in order to analyse the magnetic behaviour of iron and cobalt and also the part played by the magnetic interactions in the values of the cobalt or iron moments. The model used will be generally the molecular field model. In the second chapter we present comparatively the structure of crystalline and amorphous compounds for further correlation with the magnetic properties. In chapter III we analyse the magnetic interactions in some crystalline and amorphous rare-earth alloys. Finally, we exemplify the ways in which we ensure better requried characteristics by the technical utilizations of these materials. These have in view the modifications of the magnetic interactions and are closely related with the analysis made in chapter III

  5. Dietary compounds as modulators of metals and metalloids toxicity.

    Science.gov (United States)

    Jadán-Piedra, Carlos; Chiocchetti, Gabriela Matuoka; Clemente, María Jesús; Vélez, Dinoraz; Devesa, Vicenta

    2017-07-07

    A large part of the population is exposed to metals and metalloids through the diet. Most of the in vivo studies on its toxicokinetics and toxicity are conducted by means of exposure through drinking water or by intragastric or intraperitoneal administration of aqueous standards, and therefore they do not consider the effect of the food matrix on the exposure. Numerous studies show that some components of the diet can modulate the toxicity of these food contaminants, reducing their effect on a systemic level. Part of this protective role may be due to a reduction of intestinal absorption and subsequent tissue accumulation of the toxic element, although it may also be a consequence of their ability to counteract the toxicity directly by their antioxidant and/or anti-inflammatory activity, among other factors. The present review provides a compilation of existing information about the effect that certain components of the diet have on the toxicokinetics and toxicity of the metals and metalloids of greatest toxicological importance that are present in food (arsenic, cadmium, lead, and mercury), and of their most toxic chemical species.

  6. Hydrophilic Nb{sup 5+}-immobilized magnetic core–shell microsphere – A novel immobilized metal ion affinity chromatography material for highly selective enrichment of phosphopeptides

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xueni; Liu, Xiaodan; Feng, Jianan [Pharmaceutical Analysis Department, School of Pharmacy, Fudan University, Shanghai 201203 (China); Li, Yan, E-mail: yanli@fudan.edu.cn [Pharmaceutical Analysis Department, School of Pharmacy, Fudan University, Shanghai 201203 (China); Deng, Chunhui [Department of Chemistry and Institutes of Biomedical Sciences, Fudan University, Shanghai 200433 (China); Duan, Gengli [Pharmaceutical Analysis Department, School of Pharmacy, Fudan University, Shanghai 201203 (China)

    2015-06-23

    Highlights: • A new IMAC material (Fe{sub 3}O{sub 4}@PD-Nb{sup 5+}) was synthesized. • The strong magnetic behaviors of the microspheres ensure fast and easy separation. • The enrichment ability was tested by human serum and nonfat milk. • The results were compared with other IMAC materials including the commercial kits. • All results proved the good enrichment ability, especially for multiphosphopeptides. - Abstract: Rapid and selective enrichment of phosphopeptides from complex biological samples is essential and challenging in phosphorylated proteomics. In this work, for the first time, niobium ions were directly immobilized on the surface of polydopamine-coated magnetic microspheres through a facile and effective synthetic route. The Fe{sub 3}O{sub 4}@polydopamine-Nb{sup 5+} (denoted as Fe{sub 3}O{sub 4}@PD-Nb{sup 5+}) microspheres possess merits of high hydrophilicity and good biological compatibility, and demonstrated low limit of detection (2 fmol). The selectivity was also basically satisfactory (β-casein:BSA = 1:500) to capture phosphopeptides. They were also successfully applied for enrichment of phosphopeptides from real biological samples such as human serum and nonfat milk. Compared with Fe{sub 3}O{sub 4}@PD-Ti{sup 4+} microspheres, the Fe{sub 3}O{sub 4}@PD-Nb{sup 5+} microspheres exhibit superior selectivity to multi-phosphorylated peptides, and thus may be complementary to the conventional IMAC materials.

  7. Two new POMOF compounds constructed from polyoxoanions, metals and organic ligands

    Science.gov (United States)

    Xiao, Li-Na; Zhang, Hao; Zhang, Ting-Ting; Zhang, Xiao; Cui, Xiao-Bing

    2018-03-01

    Two new POMOF compounds, namely [PMo12V2O42][Cu3(4,4'-bpy)3]·(DABCO) (1) and [PMo10V4O42][Cu2(4,4'-bpy)2][Cu(phen)2]2 (2) (DABCO = triethylenediamine, bpy = bipyridine, phen = 1,10-phenanthroline)), have been synthesized and characterized by IR, UV-Vis, XRD, elemental analysis and X-ray diffraction analysis. Crystal structure analyses reveal that compounds 1 and 2 exhibit novel 2-D layered framework structures constructed from bi-capped Keggin molybdenum-vanadium polyoxoanions, metals and organic ligands, respectively. The main difference of the two compounds is that compound 2 contains both Cu2+ and Cu+ complexes. In addition, we also investigate the catalytic properties of the two compounds, both compound 1 and 2 are excellent catalysts for the epoxidation of styrene.

  8. Thermal behaviour of nicotinic acid, sodium nicotinate and its compounds with some bivalent transition metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, A.L.C.S. do; Caires, F.J., E-mail: caires.flavio@yahoo.com.br; Gomes, D.J.C.; Gigante, A.C.; Ionashiro, M.

    2014-01-10

    Graphical abstract: - Highlights: • The transition metal ion nicotinates were synthesized. • The TG–DTA curves provided previously unreported information about thermal behaviour. • The gaseous products released were detected by TG–DSC coupled to FTIR. - Abstract: Solid-state M(L){sub 2}·nH{sub 2}O compounds, where M stands for bivalent transition metals (Mn, Fe, Co, Ni, Cu and Zn), L is nicotinate and n = 0–4.5, have been synthesized. Characterization and thermal behaviour of these compounds were investigated employing elemental analysis based on the mass losses observed in the TG–DTA curves, complexometry, X-ray diffractometry, infrared spectroscopy (FTIR), simultaneous thermogravimetric and differential thermal analysis (TG–DTA) and TG–DSC coupled to FTIR. The thermal behaviour of nicotinic acid and its sodium salt was also investigated. For the hydrated transition metal compounds, the dehydration and thermal decomposition of the anhydrous compounds occur in a single step. For the sodium nicotinate, the final residue up to 765 °C is sodium carbonate and for the transition metal nicotinates, the final residues are Mn{sub 3}O{sub 4}, Fe{sub 2}O{sub 3}, Co{sub 3}O{sub 4}, NiO, CuO and ZnO. The results also provided information concerning the thermal stability, thermal decomposition and identification of the gaseous products evolved during the thermal decomposition of the compounds.

  9. Thermal behaviour of nicotinic acid, sodium nicotinate and its compounds with some bivalent transition metal ions

    International Nuclear Information System (INIS)

    Nascimento, A.L.C.S. do; Caires, F.J.; Gomes, D.J.C.; Gigante, A.C.; Ionashiro, M.

    2014-01-01

    Graphical abstract: - Highlights: • The transition metal ion nicotinates were synthesized. • The TG–DTA curves provided previously unreported information about thermal behaviour. • The gaseous products released were detected by TG–DSC coupled to FTIR. - Abstract: Solid-state M(L) 2 ·nH 2 O compounds, where M stands for bivalent transition metals (Mn, Fe, Co, Ni, Cu and Zn), L is nicotinate and n = 0–4.5, have been synthesized. Characterization and thermal behaviour of these compounds were investigated employing elemental analysis based on the mass losses observed in the TG–DTA curves, complexometry, X-ray diffractometry, infrared spectroscopy (FTIR), simultaneous thermogravimetric and differential thermal analysis (TG–DTA) and TG–DSC coupled to FTIR. The thermal behaviour of nicotinic acid and its sodium salt was also investigated. For the hydrated transition metal compounds, the dehydration and thermal decomposition of the anhydrous compounds occur in a single step. For the sodium nicotinate, the final residue up to 765 °C is sodium carbonate and for the transition metal nicotinates, the final residues are Mn 3 O 4 , Fe 2 O 3 , Co 3 O 4 , NiO, CuO and ZnO. The results also provided information concerning the thermal stability, thermal decomposition and identification of the gaseous products evolved during the thermal decomposition of the compounds

  10. Metal-chelating compounds produced by ectomycorrhizal fungi collected from pine plantations.

    Science.gov (United States)

    Machuca, A; Pereira, G; Aguiar, A; Milagres, A M F

    2007-01-01

    To investigate the in vitro production of metal-chelating compounds by ectomycorrhizal fungi collected from pine plantations in southern Chile. Scleroderma verrucosum, Suillus luteus and two isolates of Rhizopogon luteolus were grown in solid and liquid modified Melin-Norkans (MMN) media with and without iron addition and the production of iron-chelating compounds was determined by Chrome Azurol S (CAS) assay. The presence of hydroxamate and catecholate-type compounds and organic acids was also investigated in liquid medium. All isolates produced iron-chelating compounds as detected by CAS assay, and catecholates, hydroxamates as well as oxalic, citric and succinic acids were also detected in all fungal cultures. Scleroderma verrucosum produced the greatest amounts of catecholates and hydroxamates whereas the highest amounts of organic acids were detected in S. luteus. Nevertheless, the highest catecholate, hydroxamate and organic acid concentrations did not correlate with the highest CAS reaction which was observed in R. luteolus (Yum isolate). Ectomycorrhizal fungi produced a variety of metal-chelating compounds when grown in liquid MMN medium. However, the addition of iron to all fungi cultures reduced the CAS reaction, hydroxamate and organic acid concentrations. Catecholate production was affected differently by iron, depending on the fungal isolate. The ectomycorrhizal fungi described in this study have never been reported to produce metal-chelating compound production. Moreover, apart from some wood-rotting fungi, this is the first evidence of the presence of catecholates in R. luteolus, S. luteus and S. verrucosum cultures.

  11. The Formation of Metal (M=Co(II), Ni(II), and Cu(II)) Complexes by Aminosilanes Immobilized within Mesoporous Molecular Sieves

    International Nuclear Information System (INIS)

    Park, Dong Ho; Park, Sung Soo; Choe, Sang Joon

    1999-01-01

    The immobilization of APTMS(3-(2-aminoethylamino)propyltrimethoxysilane) and AAPTMS(3-(2-(2-aminoethyl) aminoethylamino)propyltrimethoxysilane) on the surface of high quality mesoporous molecular sieves MCM-41 and MCM-48 have been confirmed by F.T.-IR spectroscopy, Raman spectroscopy, 29 Si solid state NMR, and a surface polarity measurement using Reichardt's dye. The formation of metal (Co(II), Ni(II), and Cu(II)) complexes by immobilized aminosilanes have been investigated by photoacoustic spectroscopy(PAS). The assignment of UV-Vis. PAS bands makes it possible to identify the structure of metal complexes within mesoporous molecular sieves. Co(II) ion may be coordinated mainly in a tetrahedral symmetry by two APTMS onto MCM-41, and in an octahedral one by two AAPTMS. Both Ni(II) and Cu(II) coordinated by aminosilanes within MCM-41 form possibly the octahedral complexes such as [Ni(APTMS) 2 (H 2 O) 2 ] 2+ , [Ni(AAPTMS) 2 ] 2+ , [Cu(APTMS) 2 (H 2 O) 2 ] 2+ , and [Cu(AAPTMS)(H 2 O) 3 ] 2+ , respectively. The PAS band shapes of complexes onto MCM-48 are similar to those of corresponding MCM-41 with the variation of PAS intensity. Most of metal ion(II) within MCM-41 and MCM-48 are coordinated by aminosilanes without the impregnation on the surface

  12. In situ immobilization on the silica gel surface and adsorption capacity of polymer-based azobenzene on toxic metal ions

    Science.gov (United States)

    Savchenko, Irina; Yanovska, Elina; Sternik, Dariusz; Kychkyruk, Olga; Ol'khovik, Lidiya; Polonska, Yana

    2018-03-01

    In situ immobilization of poly[(4-methacryloyloxy-(4'-carboxy)azobenzene] on silica gel surface has been performed by radical polymerization of monomer. The fact of polymer immobilization is confirmed by IR spectroscopy. TG and DSC-MS analysis showed that the mass of the immobilized polymer was 10.61%. The SEM-microphotograph-synthesized composite analysis showed that the immobilized polymer on the silica gel surface is placed in the form of fibers. It has been found that the synthesized composite exhibits the sorption ability in terms of microquantities of Cu(II), Cd(II), Pb(II), Mn(II) and Fe(III) ions in a neutral aqueous medium. The quantitative sorption of microquantities of Pb(II) and Fe(III) ions has been recorded. It has been found that immobilization of the silica gel surface leads to an increase in its sorption capacitance for Fe(III), Cu(II) and Pb(II) ions by half.

  13. Single-layer dispersions of transition metal dichalcogenides in the synthesis of intercalation compounds

    International Nuclear Information System (INIS)

    Golub, Alexander S; Zubavichus, Yan V; Slovokhotov, Yurii L; Novikov, Yurii N

    2003-01-01

    Chemical methods for the exfoliation of transition metal dichalcogenides in a liquid medium to give single-layer dispersions containing quasi-two-dimensional layers of these compounds are surveyed. Data on the structure of dispersions and their use in the synthesis of various types of heterolayered intercalation compounds are discussed and described systematically. Structural features, the electronic structure and the physicochemical properties of the resulting intercalation compounds are considered. The potential of this method of synthesis is compared with that of traditional solid-state methods for the intercalation of layered crystals.

  14. A study on compound contents for plastic injection molding products of metallic resin pigment

    International Nuclear Information System (INIS)

    Park, Young Whan; Kwak, Jae Seob; Lee, Gyu Sang

    2016-01-01

    Injection molding process is widely used for producing most plastic products. In order to make a metal-colored plastic product especially in modern luxury home alliances, metallic pigments which are mixed to a basic resin material for injection molding are available. However, the process control for the metal-colored plastic product is extremely difficult due to non-uniform melt flow of the metallic resin pigments. To improve the process efficiency, a rapid mold cooling method by a compressed cryogenic fluid and electricity mold are also proposed to decrease undesired compound contents within a molded plastic product. In this study, a quality of the metal-colored plastic product is evaluated with process parameters; injection speed, injection pressure, and pigment contents, and an influence of the rapid cooling and heating system is demonstrated

  15. Structure and catalytic properties of metal β-diketonate complexes with oxygen-containing compounds

    International Nuclear Information System (INIS)

    Nizel'skij, Yu.N.; Ishchenko, S.S.; Lipatova, T.Eh.

    1985-01-01

    The results of researches published in recent 15-20 years of complexes of metal β-diketonates (including Cr 3+ , VO 2+ , MoOΛ2 2+ , Co 3+ , Mn 3+ , Ni 2+ , Fe 3+ ) with oxygen-containing compounds (alcohols, glycols, phenols, hydroperoxides, aldehydes, esters, etc.) playing an important role in catalytic processes of oxidation, addition, polymerization and copolymerization are reviewed. Data on the nature of chemical bond of oxygen-containing reacting agents with metal β-diketonates, on structure of metal β-diketonate complexes with oxygen-containing reacting agents and thermodynamics of complexing as well as on activation of reacting agents in complexes and catalytic properties of metal β-diketonates are discussed. Stored materials make it possible to exercise directed control of metal β-diketonate activity

  16. A study on compound contents for plastic injection molding products of metallic resin pigment

    Energy Technology Data Exchange (ETDEWEB)

    Park, Young Whan; Kwak, Jae Seob [Dept. of Mechanical Engineering, Pukyong National University, Busan (Korea, Republic of); Lee, Gyu Sang [Alliance Molding Engineering TeamLG Electronics Inc., Osan (Korea, Republic of)

    2016-12-15

    Injection molding process is widely used for producing most plastic products. In order to make a metal-colored plastic product especially in modern luxury home alliances, metallic pigments which are mixed to a basic resin material for injection molding are available. However, the process control for the metal-colored plastic product is extremely difficult due to non-uniform melt flow of the metallic resin pigments. To improve the process efficiency, a rapid mold cooling method by a compressed cryogenic fluid and electricity mold are also proposed to decrease undesired compound contents within a molded plastic product. In this study, a quality of the metal-colored plastic product is evaluated with process parameters; injection speed, injection pressure, and pigment contents, and an influence of the rapid cooling and heating system is demonstrated.

  17. The effect of biomass concentration on polymer alginate in the immobilized biosorbent formation during the sorption processof heavy metal Cu2+

    Science.gov (United States)

    Rinanti, A.; Jonathan, D.; Silalahi, M. D. S.; Fachrul, M. F.; Hadisoebroto, R.

    2018-01-01

    A research in environmental biotechnology has been done to analysis adsorption of ion Cu2+ by biomass of microalgae (Chlorella sp, Ankistrodesmus braunii, Scenedesmus quadricauda) and Saccharomyces cerevisiae onto alginate polymeras immobilized biosorbent on laboratory scale. The purpose of this study is to achieve the optimum biomass concentration which gives the best biosorption performance. Biosorption of Cu2+ was carried out in continuous fixed-bed column reactor system, volume of 1.5 L, equipped with peristaltic pump with a flow rate of 13 mL/min. Biosorption of Cu2+ was investigated using immobilized biosorbent with concentration of (g biomass/g polymer) 0.25; 0.5; 1, at pH4,initial concentration Cu2+15 mg/L and 26°C±1. The results of this study showed that the increasing of biomass concentration (0 to 0.5 g/g) would result in better biosorption performance but soon decreased its performance at biomass concentration of 1 g/g. Biosorption capacity and highest removal efficiency of 0.1025 mg Cu2+/g biosorbent and 66.36% occurred by immobilized biosorbent with 0.5 g/g concentration. The connection between the variation of biomass concentration in alginate to the biosorption performance by immobilized biosorbent shown by breakthrough curve, total adsorbed metal mass(qtotal ), efficiency of removal (%R) and biosorption capacity at breakthrough(qe ). Excessive biomass concentrations lead to reduced porosity of the beads thus slowing down the adsorption process.

  18. Ultrasound-accelerated synthesis of biphenyl compounds using novel Pd(0) nanoparticles immobilized on bio-composite.

    Science.gov (United States)

    Baran, Talat

    2018-07-01

    This study describes (i) an eco-friendly approach for design of Pd(0) nanoparticles on a natural composite, which is composed of carboxymethyl cellulose/agar polysaccharides (CMC/AG), without using any toxic reducing agents and (ii) development of ultrasound assisted simple protocol for synthesis of biphenyl compounds. Chemical characterization studies of Pd(0) nanoparticles (Pd NPs@CMC/AG) revealed that size of the particles were in the range of 37-55 nm. Catalytic performance of Pd NPs@CMC/AG was evaluated in synthesis of various biphenyl compounds by using the ultrasound-assisted method that was developed in this study. Pd NPs@CMC/AG exhibited excellent catalytic performance by producing high reaction yields. In addition, Pd NPs@CMC/AG was successfully used up to six reaction cycles without losing its catalytic activity, indicating high reproducibility of Pd NPs@CMC/AG. Additionally, compared to conventional the methods, new ultrasound-assisted synthesis technique that was followed in this study exhibited some advantages such as shorter reaction time, greener reaction conditions, higher yields and easier work-up. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Immobilization of Pb, Cd, and Zn in a contaminated soil using eggshell and banana stem amendments: metal leachability and a sequential extraction study.

    Science.gov (United States)

    Ashrafi, Mehrnaz; Mohamad, Sharifah; Yusoff, Ismail; Shahul Hamid, Fauziah

    2015-01-01

    Heavy-metal-contaminated soil is one of the major environmental pollution issues all over the world. In this study, two low-cost amendments, inorganic eggshell and organic banana stem, were applied to slightly alkaline soil for the purpose of in situ immobilization of Pb, Cd, and Zn. The artificially metal-contaminated soil was treated with 5% eggshell or 10% banana stem. To simulate the rainfall conditions, a metal leaching experiment for a period of 12 weeks was designed, and the total concentrations of the metals in the leachates were determined every 2 weeks. The results from the metal leaching analysis revealed that eggshell amendment generally reduced the concentrations of Pb, Cd, and Zn in the leachates, whereas banana stem amendment was effective only on the reduction of Cd concentration in the leachates. A sequential extraction analysis was carried out at the end of the experiment to find out the speciation of the heavy metals in the amended soils. Eggshell amendment notably decreased mobility of Pb, Cd, and Zn in the soil by transforming their readily available forms to less accessible fractions. Banana stem amendment also reduced exchangeable form of Cd and increased its residual form in the soil.

  20. Diagrams of the variations in the free energy of formation of metallic compounds (1960)

    International Nuclear Information System (INIS)

    Darras, R.; Loriers, H.

    1960-01-01

    The variations in the standard free energy ΔG produced during the formation of the principal simple metallic compounds have been calculated as a function of the temperature from recently published data, and are presented in convenient diagram form. Their usefulness in metallurgy is illustrated by some possible applications. (author) [fr

  1. Neutron scattering investigation of layer-bending modes in alkali-metal--graphite intercalation compounds

    International Nuclear Information System (INIS)

    Zabel, H.; Kamitakahara, W.A.; Nicklow, R.M.

    1982-01-01

    Phonon dispersion curves for low-frequency transverse modes propagating in the basal plane have been measured in the alkali-metal--graphite intercalation compounds KC 8 , CsC 8 , KC 24 , and RbC 24 by means of neutron spectroscopy. The acoustic branches show an almost quadratic dispersion relation at small q, characteristic of strongly layered materials. The optical branches of stage-1 compounds can be classified as either graphitelike branches showing dispersion, or as almost dispersionless alkali-metal-like modes. Macroscopic shear constants C 44 and layer-bending moduli have been obtained for the intercalation compounds by analyzing the data in terms of a simple semicontinuum model. In stage-2 compounds, a dramatic softening of the shear constant by about a factor of 8 compared with pure graphite has been observed. Low-temperature results on KC 24 indicate the opening of a frequency gap near the alkali-metal Brillouin-zone boundary, possibly due to the formation of the alkali-metal superstructure

  2. Structure, production and properties of high-melting compounds and systems (hard materials and hard metals)

    International Nuclear Information System (INIS)

    Holleck, H.; Thuemmler, F.

    1979-07-01

    The report contains contributions by various authors to the research project on the production, structure, and physical properties of high-melting compounds and systems (hard metals and hard materials), in particular WC-, TaC-, and MoC-base materials. (GSCH) [de

  3. Separation of polar compounds using a flexible metal-organic framework

    NARCIS (Netherlands)

    Motkuri, R.K.; Thallapally, P.K.; Annapureddy, H.V.R.; Dang, L.X.; Krishna, R.; Nune, S.K.; Fernandez, C.A.; Liu, J.; McGrail, B.P.

    2015-01-01

    A flexible metal-organic framework constructed from a flexible linker is shown to possess the capability of separating mixtures of polar compounds (propanol isomers) by exploiting the differences in the saturation capacities of the constituents. Transient breakthrough simulations show that these

  4. Technologies for Extracting Valuable Metals and Compounds from Geothermal Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, Stephen [SIMBOL Materials

    2014-04-30

    Executive Summary Simbol Materials studied various methods of extracting valuable minerals from geothermal brines in the Imperial Valley of California, focusing on the extraction of lithium, manganese, zinc and potassium. New methods were explored for managing the potential impact of silica fouling on mineral extraction equipment, and for converting silica management by-products into commercial products.` Studies at the laboratory and bench scale focused on manganese, zinc and potassium extraction and the conversion of silica management by-products into valuable commercial products. The processes for extracting lithium and producing lithium carbonate and lithium hydroxide products were developed at the laboratory scale and scaled up to pilot-scale. Several sorbents designed to extract lithium as lithium chloride from geothermal brine were developed at the laboratory scale and subsequently scaled-up for testing in the lithium extraction pilot plant. Lithium The results of the lithium studies generated the confidence for Simbol to scale its process to commercial operation. The key steps of the process were demonstrated during its development at pilot scale: 1. Silica management. 2. Lithium extraction. 3. Purification. 4. Concentration. 5. Conversion into lithium hydroxide and lithium carbonate products. Results show that greater than 95% of the lithium can be extracted from geothermal brine as lithium chloride, and that the chemical yield in converting lithium chloride to lithium hydroxide and lithium carbonate products is greater than 90%. The product purity produced from the process is consistent with battery grade lithium carbonate and lithium hydroxide. Manganese and zinc Processes for the extraction of zinc and manganese from geothermal brine were developed. It was shown that they could be converted into zinc metal and electrolytic manganese dioxide after purification. These processes were evaluated for their economic potential, and at the present time Simbol

  5. Detection of volatile organic compounds using an optical fiber sensor coated with a sol-gel silica layer containing immobilized Nile red

    Science.gov (United States)

    Liu, Dejun; Lian, Xiaokang; Mallik, Arun Kumar; Han, Wei; Wei, Fangfang; Yuan, Jinhui; Yu, Chongxiu; Farrell, Gerald; Semenova, Yuliya; Wu, Qiang

    2017-04-01

    A simple volatile organic compound (VOC) sensor based on a tapered small core singlemode fiber (SCSMF) structure is reported. The tapered SCSMF fiber structure with a waist diameter of 7.0 μm is fabricated using a customized microheater brushing technique. Silica based material containing immobilized Nile red was prepared by a sol-gel method and was used as a coating applied to the surface of the tapered fiber structure. Different coating thicknesses created by a 2-pass and 4-pass coating process are investigated. The experiments demonstrate that both sensors show a linear response at different gas concentrations to all three tested VOCs (methanol, ethanol and acetone). The sensor with a thicker coating shows better sensitivities but longer response and recovery times. The best measurement resolutions for the 4-pass coating sensor are estimated to be 2.3 ppm, 1.5 ppm and 3.1 ppm for methanol, ethanol and acetone, respectively. The fastest response and recovery time of 1 min and 5 min are demonstrated by the sensor in the case of methanol.

  6. Hydrolytic stability of heavy metal compounds in fly ash of a heat power plant

    International Nuclear Information System (INIS)

    Suslova, E.P.; Pertsikov, I.Z.

    1991-01-01

    Ash and slag from solid fuels are utilized widely in building materials and road surfaces, and in agriculture for soil acidulation. For all these uses it is important to know the amount and form of heavy metal compounds contained in ash and their likely behavior when ash and slag wastes are utilized. Studying the behavior of heavy metals in ash residues at contact with water media is important also because, for most trace elements, the authors lack experimental data that would enable us to predict their behavior after prolonged storage and industrial utilization. The present paper describes a study of lixiviation (at various pH in static conditions) of heavy metals form fly ash obtained by burning Azeisk coal. Homogenized ash selected from electric filter sections 1-4 was used, which has the following composition (%): SiO 2 59.8; Al 2 O 3 ; Fe 23 O 3 7.1; CaO 4.1; MgO 1.3; other 2.8. In a neutral medium, Ni, Cu, Zn, Pb, and Mn lixiviation was slight, amounting to 0.01-0.4%. During coal combustion, these elements apparently form compounds that are slightly soluble in water, although it is also possible that ash retains high adsorptivity for heavy metals. As a result, in these conditions the reverse process of sorption of heavy metals from the solution by fly ash is also possible, which would reduce the heavy metal concentration in the solution

  7. New spintronic superlattices composed of half-metallic compounds with zinc-blende structure

    International Nuclear Information System (INIS)

    Fong, C Y; Qian, M C

    2004-01-01

    The successful growth of zinc-blende half-metallic compounds, namely CrAs and CrSb, in thin film forms offers a new direction to search for novel spintronic materials. By using a well documented first-principles algorithm, the VASP code, we predict the electronic and magnetic properties of superlattices made of these exciting half-metallic materials. Not only are the superlattices constructed with two of the half-metallic compounds (CrAs/MnAs) but also they are modelled to combine with both a III-V (GaAs-MnAs/CrAs/GaAs) and a IV-IV (MnC/SiC) semiconductor. We investigate variable thicknesses for the combinations. For every case, we find the equilibrium lattice constant as well as the lattice constant at which the superlattice exhibits the half-metallic properties. For CrAs/MnAs, the half-metallic properties are presented and the magnetic moments are shown to be the sum of the moments for MnAs and CrAs. The half-metallic properties of GaAs-MnAs/CrAs/GaAs are found to be crucially dependent on the completion of the d-p hybridization. The magnetic properties of MnC/SiC are discussed with respect to the properties of MnC

  8. Co-immobilization of multiple enzymes by metal coordinated nucleotide hydrogel nanofibers: improved stability and an enzyme cascade for glucose detection.

    Science.gov (United States)

    Liang, Hao; Jiang, Shuhui; Yuan, Qipeng; Li, Guofeng; Wang, Feng; Zhang, Zijie; Liu, Juewen

    2016-03-21

    Preserving enzyme activity and promoting synergistic activity via co-localization of multiple enzymes are key topics in bionanotechnology, materials science, and analytical chemistry. This study reports a facile method for co-immobilizing multiple enzymes in metal coordinated hydrogel nanofibers. Specifically, four types of protein enzymes, including glucose oxidase, Candida rugosa lipase, α-amylase, and horseradish peroxidase, were respectively encapsulated in a gel nanofiber made of Zn(2+) and adenosine monophosphate (AMP) with a simple mixing step. Most enzymes achieved quantitative loading and retained full activity. At the same time, the entrapped enzymes were more stable against temperature variation (by 7.5 °C), protease attack, extreme pH (by 2-fold), and organic solvents. After storing for 15 days, the entrapped enzyme still retained 70% activity while the free enzyme nearly completely lost its activity. Compared to nanoparticles formed with AMP and lanthanide ions, the nanofiber gels allowed much higher enzyme activity. Finally, a highly sensitive and selective biosensor for glucose was prepared using the gel nanofiber to co-immobilize glucose oxidase and horseradish peroxidase for an enzyme cascade system. A detection limit of 0.3 μM glucose with excellent selectivity was achieved. This work indicates that metal coordinated materials using nucleotides are highly useful for interfacing with biomolecules.

  9. Efficient fabrication of high-capacity immobilized metal ion affinity chromatographic media: The role of the dextran-grafting process and its manipulation.

    Science.gov (United States)

    Zhao, Lan; Zhang, Jingfei; Huang, Yongdong; Li, Qiang; Zhang, Rongyue; Zhu, Kai; Suo, Jia; Su, Zhiguo; Zhang, Zhigang; Ma, Guanghui

    2016-03-01

    Novel high-capacity Ni(2+) immobilized metal ion affinity chromatographic media were prepared through the dextran-grafting process. Dextran was grafted to an allyl-activated agarose-based matrix followed by functionalization for the immobilized metal ion affinity chromatographic media. With elaborate regulation of the allylation degree, dextran was completely or partly grafted to agarose microspheres, namely, completely dextran-grafted agarose microspheres and partly dextran-grafted ones, respectively. Confocal laser scanning microscope results demonstrated that a good adjustment of dextran-grafting degree was achieved, and dextran was distributed uniformly in whole completely dextran-grafted microspheres, while just distributed around the outside of the partly dextran-grafted ones. Flow hydrodynamic properties were improved greatly after the dextran-grafting process, and the flow velocity increased by about 30% compared with that of a commercial chromatographic medium (Ni Sepharose FF). A significant improvement of protein binding performance was also achieved by the dextran-grafting process, and partly dextran-grafted Ni(2+) chelating medium had a maximum binding capacity for His-tagged lactate dehydrogenase about 2.5 times higher than that of Ni Sepharose FF. The results indicated that this novel chromatographic medium is promising for applications in high-efficiency and large-scale protein purification. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Investigations in anhydrous liquid ammonia. Reaction of group 2, 4, 5, 11 metal and actinoids compounds

    International Nuclear Information System (INIS)

    Woidy, Patrick

    2014-01-01

    The solubility and reactivity of metal halides, transition metal halides, and actinoid halides in liquid ammonia can lead to new starting materials for the synthesis of fluorides in low oxidation states or for nitrides via a ''low-temperature route''. In this context the ability of metal and actinoid halides to act as an acceptor for or donor of fluoride ions is also of interest. Four different systems were investigated in this study. In the first section, the synthesis and characterization of new compounds were carried out in the system CuX/NH 3 (X = F, Cl, Br, I, and CN) and lead to a ligand stabilized monovalent copper fluoride as a main result. In the second section, the solubility of uranyl compounds and uranium halides in liquid ammonia was investigated and the products were characterized. In the third section, alkali metal thorates were synthesized. Their solubility in liquid ammonia and their behavior as an acceptor for fluoride ions was investigated. In the last section, the results on the solubility behavior of transition metal halides in liquid ammonia and their coordination behavior are presented. In the first system CuX/NH 3 several new compounds, such as [Cu(NH 3 ) 3 ]X (X = Br, I or CN) were synthesized and characterized. The reactions of this compounds with fluoride ion donors (NH 4 F or Me 4 NF) led unfortunately not to the monovalent copper fluoride CuF. The comproportionation reaction of Cu and CuF 2 in liquid ammonia lead to the compounds [Cu(NH 3 ) 3 ] 2 [Cu 2 (NH 3 ) 2 ] . 4 NH 3 and [Cu(NH 3 ) 2 ]F . NH 3 . For the preparation of binary CuF, various decomposition experiments were executed on the compound [Cu(NH 3 ) 2 ]F . NH 3 which resulted in different decomposition products. In additional studies various complexes of divalent copper was investigated and with the compound [Cu(NH 3 ) 5 ]F 2 . NH 3 the solubility of fluoride containing substances in liquid ammonia could be shown. Studies of six- and tetravalent uranium

  11. Heavy-metal compounds in the environment of the Zagorsk pumped-storage station region

    International Nuclear Information System (INIS)

    Dmitrieva, I.L.; Zagoskin, V.A.; Boldenkov, V.S.; Brusilovskii, O.V.

    1993-01-01

    The Zagorsk pumped-storage station (ZPSS) is being constructed in a rather developed area. Pollution of the environment by compounds of metals is, in particular, a consequence. The tasks of this investigation included: the establishment of the main sources of pollution of terrestrial and aquatic ecosystems by metal compounds in the region of construction of the ZPSS; determination of the level of content of these substances in various components of the landscape; and evaluation of the effect of regulating the Kun'ya River on processes of migration and accumulation of heavy metals in aquatic ecosystems. In conformity with these tasks, a comprehensive geochemical study was performed in 1990-1991 of the drainage basin of the Kun'ya River, the results of which are presented here. Samples were collected of soil, forest litter, snow, bottom sediments, and surface waters. The investigation showed that the main sources of pollution of the aquatic environment in the ZPSS construction region by heavy-metal compounds were surface runoff from developed territories and insufficiently treated industrial wastewaters. 5 refs., 2 figs., 4 tabs

  12. Stability and electronic structure of Zr-based ternary metallic glasses and relevant compounds

    International Nuclear Information System (INIS)

    Hasegawa, M.; Soda, K.; Sato, H.; Suzuki, T.; Taketomi, T.; Takeuchi, T.; Kato, H.; Mizutani, U.

    2007-01-01

    The electronic structure of the Zr-based metallic glasses has been investigated by theoretical and experimental approaches. One approach is band calculations of the Zr 2 Ni (Zr 66.7 Ni 33.3 ) compound to investigate the electronic structure of the Zr 66.7 Ni 33.3 metallic glass (ΔT x = 0 K) of which the local atomic structure is similar to that of the Zr 2 Ni compound. The other is photoemission spectroscopy of the Zr 50 Cu 35 Al 15 bulk metallic glass (BMG) (ΔT x = 69 K). Here ΔT x = T x - T g where T x and T g are crystallization and glass transition temperature, respectively. Both results and previous ones on the Zr 55 Cu 30 Ni 5 Al 10 BMG indicate that there is a pseudogap at the Fermi level in the electronic structure of these Zr-based metallic glasses, independent of the value of the ΔT x . This implies that the pseudogap at the Fermi level is one of the factors that stabilize the glass phase of Zr-based metallic glasses

  13. Study of impurity composition of some compounds of refractory metals by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Kaganov, L.K.; Dzhumakulov, D.T.; Mukhamedshina, N.M.

    1994-01-01

    The compounds of refractory transition metals find wide application in all fields of engineering, in particular in microelectronics to manufacture contact-barrier layers of thin-film current-conducting systems of silicon instruments, large and very large scale integrated circuits. Production of such materials is realted with the need to apply the analytical control methods that allow to determine a large number of elements with high reliability. The instrumental neutron-activation techniques have been developed to determine impurity composition of the following compounds: MoSi 2 , WSi 2 , TiB 2 , NbB 2 , TiC, NbC

  14. Generation, detection and characterization of gas-phase transition metal aggregates and compounds

    International Nuclear Information System (INIS)

    Steimle, T.C.

    1992-01-01

    The goal of our research is to employ spectroscopic techniques to characterize the bound portions of the potential energy surface (PES) for chemical systems involving diatomic and triatomic transition metal molecules. The approach incorporates the generation and isolation of new metal compounds via supersonic laser ablation molecular beam techniques. Detection and characterization is achieved using high resolution dye laser induced fluorescence spectroscopy. A major objective is to produce information which can be compared to theoretical predictions and thereby provide guidelines and insight into the development of reaction models

  15. Apoptosis induction in human lymphocytes after in vitro exposure to cobalt/hard metal compounds

    International Nuclear Information System (INIS)

    Boeck, M. de; Decordier, I.; Lombaert, N.; Cundari, E.; Kirsch-Volders, M.; Lison, D.

    2001-01-01

    Full text: An increased risk of lung cancer is associated with occupational exposure to mixtures of cobalt metal (Co) and tungsten carbide (WC) particles, but apparently not when exposure is to cobalt alone. The mechanism for this increased cancer risk is not fully understood. The evaluation of the in vitro genotoxic effects in lymphocytes exposed to varying cobalt species demonstrated that the WC-Co hard metal mixture is more genotoxic (DNA damage, chromosome/genome mutations) than metallic Co alone. WC alone was not genotoxic. Thus, WC-Co represents a specific (geno)toxic entity. In order to assess the survival of human lymphocytes after in vitro exposure to metallic Co, CoCl 2 , WC and the WC-Co mixture, two apoptosis/necrosis detection methods were applied (annexin V staining and flow cytometry). Annexin-V staining of early apoptotic cells demonstrated a dose- and time dependent induction of apoptosis by metallic Co, CoCl 2 , WC and the WC-Co mixture. The time course of the process varied according to the metal species tested. Metallic Co and CoCl 2 caused a gradually increasing frequency of apoptotic cells with time (up to 24 h). WC-induced apoptosis displayed a typical 6 hour peak, which was not the case for the WC-Co mixture or for Co. Apoptosis induction by the WC-Co mixture was intermediate between that induced by Co and WC separately. Analysis of propidium iodide stained cells by flow cytometry was performed as a later marker for apoptosis induction. Preliminary data indicate similar tendencies of apoptosis induction as those detected by annexin-V. Identification of the apoptotic pathway triggered by the metal compounds was studied by inhibition of the ceramide-apoptosis pathway by fumonisin causing reduction of apoptosis induction for all compounds, but strongest after 6 hour exposure to WC. The use of specific caspase inhibitors will allow to further elucidate the different pathways involved. The current data demonstrating in vitro the apoptosis

  16. Apoptosis induction in human lymphocytes after in vitro exposure to cobalt/hard metal compounds

    Energy Technology Data Exchange (ETDEWEB)

    Boeck, M de; Decordier, I; Lombaert, N; Cundari, E; Kirsch-Volders, M [Vrije Universiteit Brussel, Laboratorium voor Cellulaire Genetica, Brussel (Belgium); Lison, D [Universite catholique de Louvain, Unite de Toxicologie industrielle et Medecine du Travail, Bruxelles (Belgium)

    2001-07-01

    Full text: An increased risk of lung cancer is associated with occupational exposure to mixtures of cobalt metal (Co) and tungsten carbide (WC) particles, but apparently not when exposure is to cobalt alone. The mechanism for this increased cancer risk is not fully understood. The evaluation of the in vitro genotoxic effects in lymphocytes exposed to varying cobalt species demonstrated that the WC-Co hard metal mixture is more genotoxic (DNA damage, chromosome/genome mutations) than metallic Co alone. WC alone was not genotoxic. Thus, WC-Co represents a specific (geno)toxic entity. In order to assess the survival of human lymphocytes after in vitro exposure to metallic Co, CoCl{sub 2}, WC and the WC-Co mixture, two apoptosis/necrosis detection methods were applied (annexin V staining and flow cytometry). Annexin-V staining of early apoptotic cells demonstrated a dose- and time dependent induction of apoptosis by metallic Co, CoCl{sub 2}, WC and the WC-Co mixture. The time course of the process varied according to the metal species tested. Metallic Co and CoCl{sub 2} caused a gradually increasing frequency of apoptotic cells with time (up to 24 h). WC-induced apoptosis displayed a typical 6 hour peak, which was not the case for the WC-Co mixture or for Co. Apoptosis induction by the WC-Co mixture was intermediate between that induced by Co and WC separately. Analysis of propidium iodide stained cells by flow cytometry was performed as a later marker for apoptosis induction. Preliminary data indicate similar tendencies of apoptosis induction as those detected by annexin-V. Identification of the apoptotic pathway triggered by the metal compounds was studied by inhibition of the ceramide-apoptosis pathway by fumonisin causing reduction of apoptosis induction for all compounds, but strongest after 6 hour exposure to WC. The use of specific caspase inhibitors will allow to further elucidate the different pathways involved. The current data demonstrating in vitro the

  17. Stable ABTS Immobilized in the MIL-100(Fe) Metal-Organic Framework as an Efficient Mediator for Laccase-Catalyzed Decolorization.

    Science.gov (United States)

    Liu, Youxun; Geng, Yuanyuan; Yan, Mingyang; Huang, Juan

    2017-06-02

    The successful encapsulation of 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), a well-known laccase mediator, within a mesoporous metal-organic framework sample (i.e., MIL-100(Fe)) was achieved using a one-pot hydrothermal synthetic method. The as-prepared ABTS@MIL-100(Fe) was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, nitrogen sorption, and cyclic voltammetry (CV). Our ABTS@MIL-100(Fe)-based electrode exhibited an excellent electrochemical response, indicating that MIL-100(Fe) provides an appropriate microenvironment for the immobilization and electroactivity of ABTS molecules. ABTS@MIL-100(Fe) was then evaluated as an immobilized laccase mediator for dye removal using indigo carmine (IC) as a model dye. Through the application of laccase in combination with a free (ABTS) or immobilized (ABTS@MIL-100(Fe)) mediator, decolorization yields of 95% and 94%, respectively, were obtained for IC after 50 min. In addition, following seven reuse cycles of ABTS@MIL-100(Fe) for dye treatment, a decolorization yield of 74% was obtained. Dye decolorization occurred through the breakdown of the chromophoric group by the Laccase/ABTS@MIL-100(Fe) system, and a catalytic mechanism was proposed. We therefore expect that the stability, reusability, and validity of ABTS@MIL-100(Fe) as a laccase mediator potentially render it a promising tool for dye removal, in addition to reducing the high running costs and potential toxicity associated with synthetic mediators.

  18. Calculations of hyperfine interactions in transition metal compounds in the local density approximation

    International Nuclear Information System (INIS)

    Guenzburger, D.J.R.

    1982-01-01

    A survey is made of some theoretical calculations of electrostatic and magnetic hyperfine interactions in transition metal compounds and complex irons. The molecular orbital methods considered are the Multiple Scattering and Discrete Variational, in which the local Xα approximation for the exchange interaction is employed. Emphasis is given to the qualitative informations, derived from the calculations, relating the hyperfine parameters to characteristics of the chemical bonds. (Author) [pt

  19. μSR-studies of magnetic properties of metallic rare earth compounds

    International Nuclear Information System (INIS)

    Asch, L.; Kalvius, G.M.; Chappert, J.; Yaouanc, A.; Hartmann, O.; Karlsson, E.; Wappling, R.

    1984-01-01

    Positive muons can probe the magnitude and the time dependence of the magnetic field at interstitial sites in condensed matter. Thus the relatively new techniques of muons spin rotation and muon spin relaxation have become unique tools for studying magnetism. After a brief introduction into the experimental method we then discuss measurements on the elemental rare earth metals and on intermetallic compounds, in particular on the cubic Laves phases REAl 2

  20. Mixed valence transition metal 2D-oxides: Comparison between delafossite and crednerite compounds

    Science.gov (United States)

    Martin, Christine; Poienar, Maria

    2017-08-01

    Transition metal oxides offer large opportunities to study relationships between structures and properties. Indeed these compounds crystallize in numerous frameworks corresponding to different dimensionalities and, accordingly, show a huge variety of properties (as high Tc superconductivity, colossal magnetoresistivity, multiferroicity..). The control of the oxidation state of the transition metal, via the monitoring of the oxygen content, is of prime importance to understand and optimize the properties, due to the strong coupling that exists between the lattice and the charges and spins of the transition metals. In this large playground for chemists, we reinvestigated several 2D-compounds derived from delafossite structure. Considering this paper as a very short review, we report here the results obtained on CuMO2 compounds (with M = Cr, Mn or Mn+Cu) by using a combination of techniques, as X-ray, neutrons and/or electrons diffraction on poly-crystals for structural characterisations that are correlated with electrical and/or magnetic properties. The complementarity of studies is also addressed by the synthesis and characterization of single crystals in addition to poly-crystals. Moreover the comparison of the structures of similar Cr and Mn based oxides highlights the crucial role of the Jahn-Teller effect of trivalent manganese to lift the degeneracy, which is responsible of the magnetic frustration in CuCrO2.

  1. Magnetism in ordered metallic perovskite compound GdPd3BxC1-x

    International Nuclear Information System (INIS)

    Pandey, Abhishek; Mazumdar, Chandan; Ranganathan, R.; Dattagupta, S.

    2009-01-01

    We report results of dc-magnetization, ac-susceptibility and magnetoresistance measurements on crystalline metallic-perovskite compounds GdPd 3 B x C 1-x (x=0.25, 0.50, 0.75 and 1.00) and the parent cubic compound GdPd 3 . The interest in these materials stems from the observation of negative temperature coefficient of resistance and negative thermal expansion in some of the members of this series. In the present study, we show that by substitution of non-magnetic elements, boron and carbon, the nature of the magnetic interaction can be varied from dominating ferromagnetic to antiferromagnetic and finally to a canted magnetic structure without altering the crystal symmetry of the compounds. The variation of magnetic interaction by modifying the lattice parameter resembles Ruderman-Kittel-Kasuya-Yosida (RKKY) oscillations.

  2. Microorganism immobilization

    Science.gov (United States)

    Compere, Alicia L.; Griffith, William L.

    1981-01-01

    Live metabolically active microorganisms are immobilized on a solid support by contacting particles of aggregate material with a water dispersible polyelectrolyte such as gelatin, crosslinking the polyelectrolyte by reacting it with a crosslinking agent such as glutaraldehyde to provide a crosslinked coating on the particles of aggregate material, contacting the coated particles with live microorganisms and incubating the microorganisms in contact with the crosslinked coating to provide a coating of metabolically active microorganisms. The immobilized microorganisms have continued growth and reproduction functions.

  3. Photoacidic and Photobasic Behavior of Transition Metal Compounds with Carboxylic Acid Group(s)

    Energy Technology Data Exchange (ETDEWEB)

    O’Donnell, Ryan M. [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States; Sampaio, Renato N. [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States; Li, Guocan [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States; Johansson, Patrik G. [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States; Ward, Cassandra L. [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States; Meyer, Gerald J. [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States

    2016-03-10

    Excited state proton transfer studies of six Ru polypyridyl compounds with carboxylic acid/carboxylate group(s) revealed that some were photoacids and some were photobases. The compounds [RuII(btfmb)2(LL)]2+, [RuII(dtb)2(LL)]2+, and [RuII(bpy)2(LL)]2+, where bpy is 2,2'-bipyridine, btfmb is 4,4'-(CF3)2-bpy, and dtb is 4,4'-((CH3)3C)2-bpy, and LL is either dcb = 4,4'-(CO2H)2-bpy or mcb = 4-(CO2H),4'-(CO2Et)-2,2'-bpy, were synthesized and characterized. The compounds exhibited intense metal-to-ligand charge-transfer (MLCT) absorption bands in the visible region and room temperature photoluminescence (PL) with long τ > 100 ns excited state lifetimes. The mcb compounds had very similar ground state pKa’s of 2.31 ± 0.07, and their characterization enabled accurate determination of the two pKa values for the commonly utilized dcb ligand, pKa1 = 2.1 ± 0.1 and pKa2 = 3.0 ± 0.2. Compounds with the btfmb ligand were photoacidic, and the other compounds were photobasic. Transient absorption spectra indicated that btfmb compounds displayed a [RuIII(btfmb–)L2]2+* localized excited state and a [RuIII(dcb–)L2]2+* formulation for all the other excited states. Time dependent PL spectral shifts provided the first kinetic data for excited state proton transfer in a transition metal compound. PL titrations, thermochemical cycles, and kinetic analysis (for the mcb compounds) provided self-consistent pKa* values. The ability to make a single ionizable group photobasic or photoacidic through ligand design was unprecedented and was understood based on the orientation of the lowest-lying MLCT excited state dipole relative to the ligand that contained the carboxylic acid group(s).

  4. Mixed valence and metamagnetism in a metal flux grown compound Eu2Pt3Si5

    International Nuclear Information System (INIS)

    Sarkar, Sumanta; Subbarao, Udumula; Joseph, Boby; Peter, Sebastian C.

    2015-01-01

    A new compound Eu 2 Pt 3 Si 5 with plate shaped morphology has been grown from excess In flux. The compound crystallizes in the orthorhombic U 2 Co 3 Si 5 structure type, Ibam space group and the lattice parameters are a=10.007(2) Å, b=11.666(2) Å and c=6.0011(12) Å. The crystal structure of this compound can be conceived as inter-twinned chains of [Pt 2 Si 2 ] and [PtSi 3 ] tetrahedra connected along [100] direction to give rise to a complex three dimensional [Pt 3 Si 5 ] network. Temperature dependent magnetic susceptibility data suggests that Eu 2 Pt 3 Si 5 undergoes a strong antiferromagnetic ordering (T N =19 K) followed by a weak ferromagnetic transition (T C =5.5 K). The effective magnetic moment/Eu obtained from susceptibility data is 6.78 μ B accounts mixed valent Eu with almost 85% divalent Eu, which is supported by X-ray absorption near edge spectroscopy. The compound undergoes a metamagnetic transition under applied magnetic field through a probable spin flop mechanism. - Graphical abstract: Eu 2 Pt 3 Si 5 , a new member in the U 2 Co 3 Si 5 (Ibam) family undergoes metamagnetic transition at high magnetic field and Eu is in mixed valence state. - Highlights: • A new compound Eu 2 Pt 3 Si 5 has been synthesized using indium as an inactive metal flux. • The compound undergoes metamagnetic transition at higher field. • Eu in this compound resides in a mixed valence state

  5. The synthesis and properties of some organometallic compounds containing group IV (Ge, Sn)-group II (Zn, Cd) metal---metal bonds

    NARCIS (Netherlands)

    Des Tombe, F.J.A.; Kerk, G.J.M. van der; Creemers, H.M.J.C.; Carey, N.A.D.; Noltes, J.G.

    1972-01-01

    The reactions of triphenylgermane and triphenyltin hydride with coordinatively saturated organozinc or organocadmium compounds give organometallic complexes containing Group IV (Ge, Sn)-Group II(Zn, Cd) metal---metal bonds. The 2,2′-bipyridine complexes show solvent-dependent charge-transfer

  6. Ion spectra of the metal vapor vacuum arc ion source with compound and alloy cathodes

    Science.gov (United States)

    Sasaki, Jun; Brown, Ian G.

    1990-01-01

    In metal vapor vacuum arc (MEVVA) ion sources, vacuum arc plasma with cathodes of single, pure elements has been utilized for the production of metal ions. In this study, we have investigated the charge state distributions of ions produced in vacuum arc plasmas in a MEVVA ion source for the case when the cathode is an alloy or a compound material. The ion charge state spectra were analyzed by means of a time-of-flight apparatus. We have compared the ion spectra for a cathode of an alloy or a compound material with its constituent elements: TiC/TiN/TiO2/Ti/C, SiC/Si/C, WC/W/C U/UN/(UN-ZrC)/Zr/C, and brass/Zn/Cu. We find that the MEVVA produces ions of all constituent elements in the compound and the alloy cathodes. The charge state distribution of each element differs, however, from the charge state distribution obtained in the vacuum arc with a cathode made of the pure, single constituent element. Fractional values of the total ion numbers of each constituent element in the extracted beam depart from the stoichiometry of the elements in the cathode material. In an operation with a TiC cathode, we irradiated a 304 stainless-steel plate with the extracted beam. Results from glow-discharge spectroscopy (GDS) of the surface show that both titanium and carbon are implanted in the substrate after the irradiation.

  7. Development of metallic system multi-composite materials for compound environment and corrosion monitoring technology

    International Nuclear Information System (INIS)

    Kiuchi, Kiyoshi

    1996-01-01

    For the structural materials used for the pressure boundary of nuclear power plants and others, the long term durability over several decades under the compound environment, in which the action of radiation and the corrosion and erosion in the environment of use are superposed, is demanded. To its controlling factors, the secular change of materials due to irradiation ageing and the chemical and physical properties of extreme compound environment are related complicatedly. In the first period of this research, the development of the corrosion-resistant alloys with the most excellent adaptability to environments was carried out by the combination of new alloy design and alloy manufacturing technology. In the second period, in order to heighten the adaptability as the pressure boundary materials between different compound environments, the creation of metallic system multi-composite materials has been advanced. Also corrosion monitoring technique is being developed. The stainless steel for water-cooled reactors, the wear and corrosion-resistant superalloy for reactor core, the corrosion-resistant alloy and the metallic refractory material for reprocessing nitric acid reaction vessels are reported. (K.I.)

  8. THE RESEARCH OF THE AMOUNT OF HEAVY METALS AND NITROSO COMPOUNDS IN CONCENTRATED TOMATO PRODUCTS

    Directory of Open Access Journals (Sweden)

    V.V. Shutyuk

    2016-12-01

    Full Text Available The constant selling race results in need for improving the quality of nutrition products among in-house food and pharmaceutical processing industries, which is an all-important key to success on the consumer market. This requires constant improvement of the product producing technologies. The topical problem of quality is the presence of heavy metals and nitroso compounds in the products. The research aimed at studying the changes in the heavy metal concentration levels (including Zn, Cu, Pb in tomato products at their thickening has been conducted at the national University of Food Technologies. On the basis of the received results the relationship between the lead, copper, zinc, nitrosocompounds and the solid substances’ amount has been established. The conducted research allowed us to ascertain the fact that the amount of heavy metals and nitroso compounds in raw materials for the concentrated tomato products to be ofhigh quality must not exceed the values of 18…35 % of the limiting concentration.

  9. Thermochemistry of some binary lead and transition metal compounds by high temperature direct synthesis calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Meschel, S.V., E-mail: meschel@jfi.uchicago.edu [Illinois Institute of Technology,Thermal Processing Technology Center, 10 W. 32nd Street, Chicago, Illinois 60615 (United States); Gordon Center for Integrated Science, 929 E. 57th Street, Chicago, Illinois 60637 (United States); Nash, P. [Illinois Institute of Technology,Thermal Processing Technology Center, 10 W. 32nd Street, Chicago, Illinois 60615 (United States); Chen, X.Q.; Wei, P. [Materials processing Modeling Division, Shenyang National Laboratory for Materials Science, Institute of Metals Research, 72 Wenhua Road, Shenyang City (China)

    2015-06-05

    Highlights: • Studied binary lead-transition metal alloys by high temperature calorimetry. • Determined the enthalpies of formation of 8 alloys. • Compared the measurements with predictions by the model of Miedema and by the ab initio method. - Abstract: The standard enthalpies of formation of some binary lead and transition metal compounds have been measured by high temperature direct synthesis calorimetry. The reported results are: Pb{sub 3}Sc{sub 5}(−61.3 ± 2.9); PbTi{sub 4}(−16.6 ± 2.4); Pb{sub 3}Y{sub 5}(−64.8 ± 3.6); Pb{sub 3}Zr{sub 5}(−50.6 ± 3.1); PbNb{sub 3}(−10.4 ± 3.4); PbRh(−16.5 ± 3.3); PbPd{sub 3}(−29.6 ± 3.1); PbPt(−34.7 ± 3.3) kJ/mole of atoms. We will compare our results with previously published measurements. We will also compare the experimental measurements with enthalpies of formation of transition metal compounds with elements in the same vertical column in the periodic table. We will compare our measurements with predicted values on the basis of the semi empirical model of Miedema and coworkers and with ab initio values when available.

  10. Silica chemically bonded N-propyl kriptofix 21 and 22 with immobilized palladium nanoparticles for solid phase extraction and preconcentration of some metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Ghaedi, Mehrorang, E-mail: m_ghaedi@mail.yu.ac.ir [Chemistry Department, Yasouj University, Yasouj, 75914-353 (Iran, Islamic Republic of); Niknam, Khodabakhsh, E-mail: niknam@pgu.ac.ir [Chemistry Department, Faculty of Sciences, Persian Gulf University, Bushehr, 75169 (Iran, Islamic Republic of); Zamani, Saeed; Abasi Larki, Habib [Chemistry Department, Islamic Azad University, Omidiyeh Branch, Omidiyeh (Iran, Islamic Republic of); Roosta, Mostafa [Chemistry Department, Yasouj University, Yasouj, 75914-353 (Iran, Islamic Republic of); Soylak, Mustafa [Chemistry Department, University of Erciyes, 38039 Kayseri (Turkey)

    2013-08-01

    Silica gel chemically bonded N-propyl kriptofix 21 (SBNPK 21) and N-propyl kriptofix 22 (SBNPK 22) and subsequently immobilized with palladium nanoparticles (PNP-SBNPK 21 and PNP-SBNPK 22) to produce two new complexing lipophilic materials. Then these novel sorbents were applied for the enrichment of some metal ions and their subsequent determination by flame atomic absorption spectroscopy (FAAS). The influences of the variables including pH, amount of solid phase, sample flow rate, eluent conditions and sample volume on the metal ion recoveries were investigated. The detection limit of proposed method was in the interval 2.1–2.3 and 1.7–2.8 ng mL{sup −1} for PNP-SBNPK 21 and PNP-SBNPK 22 respectively, while the preconcentration factor was 80 for two sorbents. The relative standard deviations of recoveries were between 1.23–1.31 and 1.28–1.49 for PNP-SBNPK 21 and PNP-SBNPK 22 respectively. The method has high sorption-preconcentration efficiency even in the presence of various interfering ions. Due to the reasonable selectivity of proposed method, the relative standard deviation of recoveries of all understudied metal ions in some complicated matrices was less than 3.0%. Highlights: • Highly selective sorbents for solid phase extraction were synthesized. • The method has been successfully applied for the determination of trace metals ions. • Excellent properties of the sorbent have been illustrated in detail.

  11. Immobilization of nickel by bacterial isolates from the Indian Ridge system and the chemical nature of the accumulated metal

    Digital Repository Service at National Institute of Oceanography (India)

    Sujith, P.P.; Khedekar, V.D.; Girish, A.P.; LokaBharathi, P.A.

    crucial for optimum growth and survival of microorganisms. In order to meet the physi- ological needs for these nutritionally required trace elements, microorganisms have special uptake mechanisms for some of them. Once in the cell, the elements may... be sequestered. Ex- cess concentrations of these elements in ionic form in cells may, however, be toxic (Schmidt and Schlegel 1989). The mecha- nisms such as intracellular sequestration of metals by proteins and polyphosphate granules may be a means of metal...

  12. Soft X-ray spectroscopy of transition metal compounds: a theoretical perspective

    International Nuclear Information System (INIS)

    Bokarev, S.I.; Hilal, R.; Aziz, S.G.; Kühn, O.

    2017-01-01

    To date, X-ray spectroscopy has become a routine tool that can reveal highly local and element-specific information on the electronic structure of atoms in complex environments. Here, we report on the development of an efficient and versatile theoretical methodology for the treatment of soft X-ray spectra of transition metal compounds based on the multi-configurational self-consistent field electronic structure theory. A special focus is put on the L-edge photon-in/photon-out and photon-in/electron-out processes, i.e. X-ray absorption, resonant inelastic scattering, partial fluorescence yield, and photoelectron spectroscopy, all treated on the same theoretical footing. The investigated systems range from small prototypical coordination compounds and catalysts to aggregates of biomolecules.

  13. Power characteristics of the metal compounds formation process during the friction stir welding

    Directory of Open Access Journals (Sweden)

    Rzaev Radmir

    2017-01-01

    Full Text Available An influence of the power characteristics on the formation process of the uniform metals compound during the welding with friction stirringis being examined in this article.A dependency between the machine-tool engine power input and the instrument tilt during the FSW for the aluminum alloy AD31, copper alloy M1, titanium alloy OT4-1 and steel St-3 low-alloyed has been explored. A question of the stabilization of power consumption process while the establishment of superplastic condition of welded metal during the FSW has also been reviewed. A dependency revealed between the power characteristics, the geometry of the formation, the rotation speeds, the longitudinal displacement of the tool and its dimensions for fixed values of the parameters during the FSW.

  14. The metal-driven biogeochemistry of gaseous compounds in the environment

    CERN Document Server

    Kroneck, Peter MH

    2014-01-01

    MILS-14 provides a most up-to-date view of the exciting biogeochemistry of gases in our environment as driven mostly by microorganisms. These employ a machinery of sophisticated metalloenzymes, where especially transition metals (such as Fe, Ni, Cu, Mo, W) play a fundamental role, that is, in the activation, transformation and syntheses of gases like dihydrogen, methane, carbon monoxide, acetylene and those of the biological nitrogen and sulfur cycles. The Metal-Driven Biogeochemistry of Gaseous Compounds in the Environment is a vibrant research area based mainly on structural and microbial biology, inorganic biological chemistry and environmental biochemistry. All this is covered in an authoritative manner in 11 stimulating chapters, written by 26 internationally recognized experts and supported by nearly 1200 references, informative tables and about 100 illustrations (two thirds in color). MILS-14 also provides excellent information for teaching. Peter M. H. Kroneck is a bioinorganic chemist who is explorin...

  15. Composite materials obtained by the ion-plasma sputtering of metal compound coatings on polymer films

    Science.gov (United States)

    Khlebnikov, Nikolai; Polyakov, Evgenii; Borisov, Sergei; Barashev, Nikolai; Biramov, Emir; Maltceva, Anastasia; Vereshchagin, Artem; Khartov, Stas; Voronin, Anton

    2016-01-01

    In this article, the principle and examples composite materials obtained by deposition of metal compound coatings on polymer film substrates by the ion-plasma sputtering method are presented. A synergistic effect is to obtain the materials with structural properties of the polymer substrate and the surface properties of the metal deposited coatings. The technology of sputtering of TiN coatings of various thicknesses on polyethylene terephthalate films is discussed. The obtained composites are characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and scanning tunneling microscopy (STM) is shown. The examples of application of this method, such as receiving nanocomposite track membranes and flexible transparent electrodes, are considered.

  16. Micro- and Nanostructured Metal Oxide Chemical Sensors for Volatile Organic Compounds

    Science.gov (United States)

    Alim, M. A.; Penn, B. G.; Currie, J. R., Jr.; Batra, A. K.; Aggarwal, M. D.

    2008-01-01

    Aeronautic and space applications warrant the development of chemical sensors which operate in a variety of environments. This technical memorandum incorporates various kinds of chemical sensors and ways to improve their performance. The results of exploratory investigation of the binary composite polycrystalline thick-films such as SnO2-WO3, SnO2-In2O3, SnO2-ZnO for the detection of volatile organic compound (isopropanol) are reported. A short review of the present status of the new types of nanostructured sensors such as nanobelts, nanorods, nanotube, etc. based on metal oxides is presented.

  17. Chromatographic methods for determination of metals as chelate compounds with heterocyclic azo reagents

    International Nuclear Information System (INIS)

    Basova, E.M.; Bol'shova, T.A.; Shpigun, O.A.; Ivanov, V.M.

    1993-01-01

    Methods for separation and concentration of transition metals as well as cadmium in form of chelates with heterocyclic azo compounds namely, PAN(1-(2-pyridylaso)-2-naphthol), PAR(4-(2-pyridylazo)-resorcin), Br-PAAP (2-(5-bromine-2-pyridylazo)-5-diethyl aminophenol) are considered. The Br-PAAP reagent is the most sensitive and widely-applied one in extraction and highly-efficient liquid chromatography. Methods of sorption concentration with subsequent element determination directly on the sorbent without microelements separation or destruction are the most promissing ones

  18. Recent Progress in Graphite Intercalation Compounds for Rechargeable Metal (Li, Na, K, Al)-Ion Batteries.

    Science.gov (United States)

    Xu, Jiantie; Dou, Yuhai; Wei, Zengxi; Ma, Jianmin; Deng, Yonghong; Li, Yutao; Liu, Huakun; Dou, Shixue

    2017-10-01

    Lithium-ion batteries (LIBs) with higher energy density are very necessary to meet the increasing demand for devices with better performance. With the commercial success of lithiated graphite, other graphite intercalation compounds (GICs) have also been intensively reported, not only for LIBs, but also for other metal (Na, K, Al) ion batteries. In this Progress Report, we briefly review the application of GICs as anodes and cathodes in metal (Li, Na, K, Al) ion batteries. After a brief introduction on the development history of GICs, the electrochemistry of cationic GICs and anionic GICs is summarized. We further briefly summarize the use of cationic GICs and anionic GICs in alkali ion batteries and the use of anionic GICs in aluminium-ion batteries. Finally, we reach some conclusions on the drawbacks, major progress, emerging challenges, and some perspectives on the development of GICs for metal (Li, Na, K, Al) ion batteries. Further development of GICs for metal (Li, Na, K, Al) ion batteries is not only a strong supplement to the commercialized success of lithiated-graphite for LIBs, but also an effective strategy to develop diverse high-energy batteries for stationary energy storage in the future.

  19. Some reduced ternary and quaternary oxides of molybdenum. A family of compounds with strong metal-metal bonds

    International Nuclear Information System (INIS)

    Torardi, C.C.; McCarley, R.E.

    1981-01-01

    Several new, reduced ternary and quaternary oxides of molybdenum are reported, each containing molybdenum in an average oxidation state 2 sealed in Mo tubes held at 1100 0 C for ca. 7 days. Refinement of the substructure of the new compound Ba 0 62 Mo 4 O 6 was based on an orthorhombic cells, with a = 9.509(2), b = 9.825(2), c = 2.853(1) A, Z = 2 in space group Pbam; weak supercell reflections indicate the true structure has c = 8(2.853) A. The chief structural feature is closely related to that of NaMo 4 O 6 which consists of infinite chains of Mo 6 octahedral clusters fused on opposite edges, bridged on the outer edges by O atoms and crosslinked by Mo-O-Mo bonding to create four-sided tunnels in which the Ba 2+ ions are located. The structure of Ba 1 13 Mo 8 O 16 is triclinic, a = 7.311(1), b = 7.453(1), c = 5.726(1) A, α = 101.49(2), β = 99.60(2), γ = 89.31(2) 0 , Z = 1, space group P1. It is a low-symmetry, metal-metal bonded variant of the hollandite structure, in which two different infinite chains, built up from Mo 4 O 8 2- and Mo 4 O 8 0 26- cluster units, respectively, are interlinked via Mo-O-Mo bridge bonding to create again four-sided tunnels in which the Ba 2+ ions reside. Other compounds prepared and characterized by analyses and x-ray powder diffraction data are Pb/sub x/Mo 4 O 6 (x approx. 0.6), LiZn 2 Mo 3 O 8 , , CaMo 5 O 8 , K 2 Mo 12 O 19 , and Na 2 Mo 12 O 19

  20. Electronic structure, Fermi surface and optical properties of metallic compound Be8(B48)B2

    International Nuclear Information System (INIS)

    Reshak, A.H.; Azam, Sikander; Alahmed, Z.A.; Chyský, Jan

    2014-01-01

    The band structure, density of states, electronic charge density, Fermi surface and optical properties for B 8 (Be 48 )B 2 compound has been investigated in the support of density functional theory (DFT). The atomic positions of B 8 (Be 48 )B 2 compound were optimized by minimization of the forces acting on the atoms using the full potential linear augmented plane wave (FPLAPW) method. We have employed the local density approximation (LDA), generalized gradient approximation (GGA) and Engal-Vosko GGA (EVGGA) to indulgence the exchange correlation potential by solving Kohn–Sham equations. The result shows that the compound is metallic with sturdy hybridization near the Fermi energy level (E F ). The density of states at Fermi energy, N(E F ), is determined by the overlaping between B-p, B-s and Be-s states. This overlaping is strong enough indicating metallic origin with different values of N(E F ). These values are 16.4, 16.27 and 14.89 states/eV, and the corresponding bare linear low-temperature electronic specific heat coefficient (γ) is found to be 2.84, 2.82 and 2.58 mJ/mol K 2 for EVGGA, GGA and LDA respectively. There exists a strong hybridization between B-s and B-p states, also between B-s and Be-p states around the Fermi level. The Fermi surface is composed of three sheets. These sheets consist of set of holes and electrons. The bonding features of the compounds are analyzed using the electronic charge density in the (101 and −101) crystallographic planes and also the analyzing of charge density shows covalent bonding between B and B. The linear optical properties are also deliberated and discussed in particulars. - Highlights: • The compound is metallic. • The density of states at the Fermi energy is calculated. • The bare linear low-temperature electronic specific heat coefficient is obtained. • Fermi surface is composed of three sheets. • The bonding features are analyzed using the electronic charge density

  1. Two-step purification of His-tagged Nef protein in native condition using heparin and immobilized metal ion affinity chromatographies.

    Science.gov (United States)

    Finzi, Andrés; Cloutier, Jonathan; Cohen, Eric A

    2003-07-01

    The Nef protein encoded by human immunodeficiency virus type 1 (HIV-1) has been shown to be an important factor of progression of viral growth and pathogenesis in both in vitro and in vivo. The lack of a simple procedure to purify Nef in its native conformation has limited molecular studies on Nef function. A two-step procedure that includes heparin and immobilized metal ion affinity chromatographies (IMACs) was developed to purify His-tagged Nef (His(6)-Nef) expressed in bacteria in native condition. During the elaboration of this purification procedure, we identified two closely SDS-PAGE-migrating contaminating bacterial proteins, SlyD and GCHI, that co-eluted with His(6)-Nef in IMAC in denaturing condition and developed purification steps to eliminate these contaminants in native condition. Overall, this study describes a protocol that allows rapid purification of His(6)-Nef protein expressed in bacteria in native condition and that removes metal affinity resin-binding bacterial proteins that can contaminate recombinant His-tagged protein preparation.

  2. Exploiting multi-function Metal-Organic Framework nanocomposite Ag@Zn-TSA as highly efficient immobilization matrixes for sensitive electrochemical biosensing

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Sheying, E-mail: dongsyy@126.com [College of Sciences, Xi' an University of Architecture and Technology, Xi' an, 710055 (China); Zhang, Dandan; Suo, Gaochao; Wei, Wenbo [College of Sciences, Xi' an University of Architecture and Technology, Xi' an, 710055 (China); Huang, Tinglin [School of Environmental and Municipal Engineering, Xi' an University of Architecture and Technology, Xi' an, 710055 (China)

    2016-08-31

    A novel multi-function Metal-Organic Framework composite Ag@Zn-TSA (zinc thiosalicylate, Zn(C{sub 7}H{sub 4}O{sub 2}S), Zn-TSA) was synthesized as highly efficient immobilization matrixes of myoglobin (Mb)/glucose oxidase (GOx) for electrochemical biosensing. The electrochemical biosensors based on Ag@Zn-TSA composite and ionic liquid (IL) modified carbon paste electrode (CPE) were fabricated successfully. Furthermore, the properties of the sensors were discussed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and amperometric current-time curve, respectively. The results showed the proposed biosensors had wide linear response to hydrogen peroxide (H{sub 2}O{sub 2}) in the range of 0.3–20,000 μM, to nitrite (NO{sub 2}{sup −}) for 1.3 μM–1660 μM and 2262 μM–1,33,000 μM, to glucose for 2.0–1022 μM, with a low detection limit of 0.08 μM for H{sub 2}O{sub 2}, 0.5 μM for NO{sub 2}{sup −}, 0.8 μM for glucose. The values of the apparent heterogeneous electron transfer rate constant (k{sub s}) for Mb and GOx were estimated as 2.05 s{sup −1} and 2.45 s{sup −1}, respectively. Thus, Ag@Zn-TSA was a kind of ideal material as highly efficient immobilization matrixes for sensitive electrochemical biosensing. In addition, this work indicated that MOF nanocomposite had a great potential for constructing wide range of sensing interface. - Highlights: • Novel Ag@Zn-TSA was used as highly efficient immobilization matrixes of Mb/glucose. • We exploited multi-function MOFs for a wide range of electrocatalytic sensing interface. • The proposed biosensors had an excellent catalytic effect on the small molecule (NO{sub 2}{sup −}, H{sub 2}O{sub 2}, glucose).

  3. Exploiting multi-function Metal-Organic Framework nanocomposite Ag@Zn-TSA as highly efficient immobilization matrixes for sensitive electrochemical biosensing

    International Nuclear Information System (INIS)

    Dong, Sheying; Zhang, Dandan; Suo, Gaochao; Wei, Wenbo; Huang, Tinglin

    2016-01-01

    A novel multi-function Metal-Organic Framework composite Ag@Zn-TSA (zinc thiosalicylate, Zn(C_7H_4O_2S), Zn-TSA) was synthesized as highly efficient immobilization matrixes of myoglobin (Mb)/glucose oxidase (GOx) for electrochemical biosensing. The electrochemical biosensors based on Ag@Zn-TSA composite and ionic liquid (IL) modified carbon paste electrode (CPE) were fabricated successfully. Furthermore, the properties of the sensors were discussed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and amperometric current-time curve, respectively. The results showed the proposed biosensors had wide linear response to hydrogen peroxide (H_2O_2) in the range of 0.3–20,000 μM, to nitrite (NO_2"−) for 1.3 μM–1660 μM and 2262 μM–1,33,000 μM, to glucose for 2.0–1022 μM, with a low detection limit of 0.08 μM for H_2O_2, 0.5 μM for NO_2"−, 0.8 μM for glucose. The values of the apparent heterogeneous electron transfer rate constant (k_s) for Mb and GOx were estimated as 2.05 s"−"1 and 2.45 s"−"1, respectively. Thus, Ag@Zn-TSA was a kind of ideal material as highly efficient immobilization matrixes for sensitive electrochemical biosensing. In addition, this work indicated that MOF nanocomposite had a great potential for constructing wide range of sensing interface. - Highlights: • Novel Ag@Zn-TSA was used as highly efficient immobilization matrixes of Mb/glucose. • We exploited multi-function MOFs for a wide range of electrocatalytic sensing interface. • The proposed biosensors had an excellent catalytic effect on the small molecule (NO_2"−, H_2O_2, glucose).

  4. Exploiting multi-function Metal-Organic Framework nanocomposite Ag@Zn-TSA as highly efficient immobilization matrixes for sensitive electrochemical biosensing.

    Science.gov (United States)

    Dong, Sheying; Zhang, Dandan; Suo, Gaochao; Wei, Wenbo; Huang, Tinglin

    2016-08-31

    A novel multi-function Metal-Organic Framework composite Ag@Zn-TSA (zinc thiosalicylate, Zn(C7H4O2S), Zn-TSA) was synthesized as highly efficient immobilization matrixes of myoglobin (Mb)/glucose oxidase (GOx) for electrochemical biosensing. The electrochemical biosensors based on Ag@Zn-TSA composite and ionic liquid (IL) modified carbon paste electrode (CPE) were fabricated successfully. Furthermore, the properties of the sensors were discussed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and amperometric current-time curve, respectively. The results showed the proposed biosensors had wide linear response to hydrogen peroxide (H2O2) in the range of 0.3-20,000 μM, to nitrite (NO2(-)) for 1.3 μM-1660 μM and 2262 μM-1,33,000 μM, to glucose for 2.0-1022 μM, with a low detection limit of 0.08 μM for H2O2, 0.5 μM for NO2(-), 0.8 μM for glucose. The values of the apparent heterogeneous electron transfer rate constant (ks) for Mb and GOx were estimated as 2.05 s(-1) and 2.45 s(-1), respectively. Thus, Ag@Zn-TSA was a kind of ideal material as highly efficient immobilization matrixes for sensitive electrochemical biosensing. In addition, this work indicated that MOF nanocomposite had a great potential for constructing wide range of sensing interface. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Periodicity effects on compound waves guided by a thin metal slab sandwiched between two periodically nonhomogeneous dielectric materials

    Science.gov (United States)

    Chiadini, Francesco; Fiumara, Vincenzo; Scaglione, Antonio; Lakhtakia, Akhlesh

    2017-10-01

    Surface-plasmon-polariton waves can be compounded when a sufficiently thin metal layer is sandwiched between two half spaces filled with dissimilar periodically nonhomogeneous dielectric materials. We solved the boundary-value problem for compound waves guided by a layer of a homogeneous and isotropic metal sandwiched between a structurally chiral material (SCM) and a periodically multilayered isotropic dielectric (PMLID) material. We found that the periodicities of the PMLID material and the SCM are crucial to excite a multiplicity of compound guided waves arising from strong coupling between the two interfaces.

  6. Genetic toxicology of metal compounds. II. Enhancement of ultraviolet light-induced mutagenesis in Escherichia coli WP2

    International Nuclear Information System (INIS)

    Rossman, T.G.; Molina, M.

    1986-01-01

    Salts of metals which are carcinogenic, noncarcinogenic, or of unknown carcinogenicity were assayed for their abilities to modulate ultraviolet (UV)-induced mutagenesis in Escherichia coli WP2. In addition to the previously reported comutagenic effect of arsenite, salts of three other compounds were found to enhance UV mutagenesis. CuCl 2 , MnCl 2 (and a small effect by KMnO 4 ), and NaMoO 4 acted as comutagens in E coli WP2, which has wild-type DNA repair capability, but were much less comutagenic in the repair deficient strain WP2/sub s/ (uvrA). The survival of irradiated or unirradiated cells was not affected by these compounds. No effects on UV mutagenesis were seen for 16 other metal compounds. We suggest that the comutagenic effects might occur either via metal-induced decreases in the fidelity of repair replication or via metal-induced depurination

  7. Stock of immobilized metals in 'Jose Antonio Alzate' dam mud sediment samples in the State of Mexico, Mexico

    International Nuclear Information System (INIS)

    Rodriguez, S.A.; Avila-Perez, P.

    1997-01-01

    'Jose Antonio Alzate' dam mud sediment samples were collected from six sampling sites. The samples were analyzed by combining multielemental studies with structural details, including heating to very high temperatures. Characterization of mud sediment samples have been shown to have low concentrations of metals (Cr, Mn, Ni, Cu, Zn, Pb). No systematic trend was observed as a function of the sampling points. (author)

  8. Impedance study of tea with added taste compounds using conducting polymer and metal electrodes.

    Science.gov (United States)

    Dhiman, Mopsy; Kapur, Pawan; Ganguli, Abhijit; Singla, Madan Lal

    2012-09-01

    In this study the sensing capabilities of a combination of metals and conducting polymer sensing/working electrodes for tea liquor prepared by addition of different compounds using an impedance mode in frequency range 1 Hz-100 KHz at 0.1 V potential has been carried out. Classification of six different tea liquor samples made by dissolving various compounds (black tea liquor + raw milk from milkman), (black tea liquor + sweetened clove syrup), (black tea liquor + sweetened ginger syrup), (black tea liquor + sweetened cardamom syrup), (black tea liquor + sweet chocolate syrup) and (black tea liquor + vanilla flavoured milk without sugar) using six different working electrodes in a multi electrode setup has been studied using impedance and further its PCA has been carried out. Working electrodes of Platinum (Pt), Gold (Au), Silver (Ag), Glassy Carbon (GC) and conducting polymer electrodes of Polyaniline (PANI) and Polypyrrole (PPY) grown on an ITO surface potentiostatically have been deployed in a three electrode set up. The impedance response of these tea liquor samples using number of working electrodes shows a decrease in the real and imaginary impedance values presented on nyquist plots depending upon the nature of the electrode and amount of dissolved salts present in compounds added to tea liquor/solution. The different sensing surfaces allowed a high cross-selectivity in response to the same analyte. From Principal Component Analysis (PCA) plots it was possible to classify tea liquor in 3-4 classes using conducting polymer electrodes; however tea liquors were well separated from the PCA plots employing the impedance data of both conducting polymer and metal electrodes.

  9. Catalysis of metal-clay intercalation compound in the low temperature coal hydrogasification

    Energy Technology Data Exchange (ETDEWEB)

    Fuda, Kiyoshi; Kimura, Mitsuhiko; Miyamoto, Norimitsu; Matsunaga, Toshiaki

    1986-10-23

    Focusing the hydrogenating methanation by gaseous phase catalytic reactions of low temperature volatile components, the catalytic effects of Ni metal and the effects of carriers having sensitive effects on the catalytic activities of Ni metal were studied. Sample coals were prepared from Shin-Yubari coal, and Ni hydride-montmorillonite complex catalysts and the catalysts produced by carring Ni nitrate on alumina and burning in hydrogen gas flows were prepared. The hydrogasification were carried out in a reaction tube. As a result, the montmorillonite-Ni compounds catalysts had high catalitic effects and high conversion ratio of 90% or more in the low temperature coal gasification. The catalitic effects of carried Ni metal strongly depended on the carrier substances, and the rank of effects for the carriers was montmorillonite>zeorite>TiO/sub 2/>alpha-Al/sub 2/O/sub 3/>MgO>SiO/sub 2/=gamma-Al/sub 2/O/sub 3/. (3 figs, 3 tabs, 3 refs)

  10. EMI Shielding Performance For Varies Frequency by Metal Plating on Mold Compound

    Directory of Open Access Journals (Sweden)

    Min Fee Tai

    2017-07-01

    Full Text Available Conformal metalization on mold compound offers new possibility for IC package design to improve features such as rigidization of the flexible core, heat sink capability, 3D-circuit patterning and the electromagnetic interference (EMI shielding. With the unique processes, the fabrication technology had enabled to achieve the high reliable performance and had passed the electrical test. Following research after the reliability concern, this paper further study the shielding effectiveness of varying coating thickness with respect to laboratory simulated EMI condition, using radio frequency from 10MHz to 5.8 GHz. Different metal namely pure nickel, nickel-phosphorous and pure plated copper are studied for their effectiveness of EMI sheilding. Our first result showed over 35-40dB of shielding effectiveness is achievable on high frequency 868-5800MHz. Nevertheless on low frequency of 10MHz, the shielding effectiveness achievement is below than 25dB. To overcome the shielding need for lower frequency, we further expanded our test by choosing ferromagentic material Nicke/Ironl-alloy in combination with thick copper plating. With this new metal combination, EMI shielding effectiveness for lower frequency is improved to 40dB.

  11. Magnetism in rare-earth metals and rare-earth intermetallic compounds

    International Nuclear Information System (INIS)

    Johansson, B.; Nordstroem, L.; Eriksson, O.; Brooks, M.S.S.

    1991-01-01

    Some of out recent local spin density electronic structure calculations for a number of ferromagnetic rare-earth systems are reviewed. A simplified model of the level densities for rare-earth (R) transition metal (M) intermetallic compounds, R m M n , is used to describe in a simple way the main features of their basic electronic structure. Explicit calculations for LuFe 2 and RFe 2 (R=Gd-Yb) systems are presented, where a method to treat simultaneously the localized 4f and the conduction electron spin magnetism is introduced. Thereby it becomes possible to calculate the K RM exchange coupling constant. This method is also used to study theoretically the permanent magnet material Nd 2 Fe 14 B. The electronic structure of the anomalous ferromagnets CeFe 2 and CeCo 5 is discussed and an induced 4f itinerant magnetism is predicted. The γ-α transition in cerium metal is considered, and results from calculations including orbital polarization are presented, where a volume collapse of 10% is obtained. On one side of the transition the 4f electrons are calculated to be essentially non-bonding (localized) and on the other side they are found to contribute to the metallic bonding and this difference in behaviour gives rise to the volume collapse. Recent calculations by Wills, Eriksson and Boring for the crystal structure changes in cerium metal under high pressure are discussed. Their successful results imply an itinerant picture for the 4f electrons in α-cerium. Consequently this strongly supports the view that the γ-α phase transformation is caused by a Mott transition of the 4f electrons. (orig.)

  12. Perspectives from ab-initio and tight-binding: Applications to transition metal compounds and superlattices

    Science.gov (United States)

    Venkataraman, Vijay Shankar

    The experimental and theoretical study of transition metal compounds have occupied condensed matter physicists for the best part of the last century. The rich variety of physical behaviour exhibited by these compounds owes its origin to the subtle balance of the energy scales at play for the d orbitals. In this thesis, we study three different systems comprised of transition metal atoms from the third, the fourth, and the fifth group of the periodic table using a combination of ab-initio density functional theory (DFT) computations and effective tight-binding models for the electronic properties. We first consider the electronic properties of artificially fabricated perovskite superlattices of the form [(SrIrO3)m / SrTiO3] with integer m denoting the number of layers of SrIrO3. After discussing the results of experiments undertaken by our collaborators, we present the results of our DFT calculations and build tight-binding models for the m = 1 and m = 2 superlattices. The active ingredient is found to be the 5d orbitals with significant spin-orbit coupling. We then study the energies of magnetic ground states within DFT and compare and contrast our results with those obtained for the bulk Ruddlesden-Popper iridates. Together with experimental measurements, our results suggest that these superlattices are an exciting venue to probe the magnetism and metal-insulator transitions that occur from the intricate balance of the spin-orbit coupling and electron interactions, as has been reported for their bulk counterparts. Next, we consider alpha-RuCl3, a honeycomb lattice compound. We first show using DFT calculations in conjunction with experiments performed by our collaborators, how spin-orbit coupling in the 4d orbitals of Ru is essential to understand the insulating state realized in this compound. Then, in the latter half of the chapter, we study the magnetic ground states of a two-dimensional analogue of alpha-RuCl3 in weak and strong-coupling regimes obtained from

  13. Synthesis and characterization of a new material based on porous silica-Chemically immobilized C,N-pyridylpyrazole for heavy metals adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Radi, Smaail [Laboratoire de Chimie Organique, Macromoleculaire et Produits Naturels, Departement de Chimie, Faculte des Sciences, Universite Mohamed 1er, BP 524, 60 000 Oujda (Morocco)], E-mail: radi_smaail@yahoo.fr; Attayibat, Ahmed [Laboratoire de Chimie Organique, Macromoleculaire et Produits Naturels, Departement de Chimie, Faculte des Sciences, Universite Mohamed 1er, BP 524, 60 000 Oujda (Morocco); Lekchiri, Yahya [Laboratoire de Biochimie, Departement de Biologie, Faculte des Sciences, Universite Mohamed 1er, BP 524, 60 000 Oujda (Morocco); Ramdani, Abdelkrim [Laboratoire de Chimie Organique, Macromoleculaire et Produits Naturels, Departement de Chimie, Faculte des Sciences, Universite Mohamed 1er, BP 524, 60 000 Oujda (Morocco); Bacquet, Maryse [Laboratoire de Chimie Macromoleculaire, Universite des Sciences et Technologies de Lille, 59655 Villeneuve d' Ascq (France)

    2008-10-15

    The immobilization of C,N-pyridylpyrazole on the surface of epoxy group containing silica gel phase for the formation of a newly synthesized material based on porous silica-bound C,N-pyridylpyrazole (SGPP) is described. The surface modification was characterized by {sup 13}C NMR of solid sample, elemental analysis and infrared spectra and was studied and evaluated by determination of the surface area using the BET equation, the adsorption and desorption capability using the isotherm of nitrogen and BJH pore sizes, respectively. The new material exhibits good thermal stability determined by thermogravimetry curves. The synthesized material was utilised in column and batch methods for separation and trace extraction of (Hg{sup 2+}, Cd{sup 2+}, Pb{sup 2+}, Cu{sup 2+}, Zn{sup 2+}, K{sup +}, Na{sup +} and Li{sup +}) and compared to results of classical liquid-liquid extraction with the unbound C,N-pyridylpyrazole compound. The grafting at the surface of silica does not affect complexing properties of the ligand and the material exhibits a high selectivity toward Hg(II)

  14. Impacts of Steel-Slag-Based Silicate Fertilizer on Soil Acidity and Silicon Availability and Metals-Immobilization in a Paddy Soil.

    Directory of Open Access Journals (Sweden)

    Dongfeng Ning

    Full Text Available Slag-based silicate fertilizer has been widely used to improve soil silicon- availability and crop productivity. A consecutive early rice-late rice rotation experiment was conducted to test the impacts of steel slag on soil pH, silicon availability, rice growth and metals-immobilization in paddy soil. Our results show that application of slag at a rate above higher or equal to 1 600 mg plant-available SiO2 per kg soil increased soil pH, dry weight of rice straw and grain, plant-available Si concentration and Si concentration in rice shoots compared with the control treatment. No significant accumulation of total cadmium (Cd and lead (Pb was noted in soil; rather, the exchangeable fraction of Cd significantly decreased. The cadmium concentrations in rice grains decreased significantly compared with the control treatment. In conclusion, application of steel slag reduced soil acidity, increased plant-availability of silicon, promoted rice growth and inhibited Cd transport to rice grain in the soil-plant system.

  15. Genetic toxicology of metal compounds: I. Induction of lambda prophage in E coli WP2/sub s/(lambda)

    Energy Technology Data Exchange (ETDEWEB)

    Rossman, T.G.; Molina, M.; Meyer, L.W.

    1984-01-01

    A number of metal compounds have been shown to be human carcinogens. Others, while not proven human carcinogens, are able to cause tumors in laboratory animals. Short-term bacterial assays for genotoxic effects have not been successful in predicting the carcinogenicity of metal compounds. The ability of some metal compounds to cause the induction of lambda prophage in E coli WP2/sub s/(lambda) is reported. By far the strongest inducing ability was observed with K/sub 2/CrO/sub 4/. With the exception of chromate, long-term exposures in a narrow, subtoxic dose range were required in order to demonstrate phage induction. A new microtiter assay for lambda prophage induction, which incorporates these features, is described. This system also was able to detect very small amounts of organic carcinogens.

  16. Application of humic compounds for remediation of soils contaminated with heavy metals: the benefits and risks

    Science.gov (United States)

    Motuzova, Galina; Barsova, Natalia; Stepanov, Andrey; Kiseleva, Violetta; Kolchanova, Ksenia; Starkova, Irina; Karpukhin, Mikhail

    2015-04-01

    found to contain only 3-9% of copper. The content of free Cu2+ ions in the sample extract was negligible. The samples used for field experiments were tested in laboratory to estimate their sorption capacity for Cu. For this purpose, 300 g of substrate (loam and mixed organic substrate) with addition of water (control) and humic preparation (same dose as in the field experiment) were kept in the laboratory for 1 week. Soil samples were then dried and brought into equilibrium with the solution of copper sulfate at concentration of 50 mg/l. The concentration of copper in the solution in equilibrium with HC was 2.5-4 times higher than in the control variant; absorption of copper by solid phase decreased by 5-6%. Results of the laboratory study were in good agreement with the results of the field experiment. Addition of HC increased the content of soluble organic matter and copper complexation by an order of magnitude and thus reduced the activity of copper ions in the liquid phase that was treated as a possible remediation effect of the humic compound for plants and biota. However the increased total metal content mainly in a migration-capable form (negatively charged complexes with organic matter) may increase the risk of contaminating ground waters with heavy metals. Therefore, application of the artificial humic compounds for remediation of soils contaminated with heavy metals requires monitoring and further development of means to prevent their migration.

  17. EDITORIAL: New materials with high spin polarization: half-metallic Heusler compounds

    Science.gov (United States)

    Felser, Claudia; Hillebrands, Burkard

    2007-03-01

    The development of magnetic Heusler compounds, specifically designed as materials for spintronic applications, has made tremendous progress in the very recent past [1-21]. Heusler compounds can be made as half-metals, showing a high spin polarization of the conduction electrons of up to 100% [1]. These materials are exceptionally well suited for applications in magnetic tunnel junctions acting, for example, as sensors for magnetic fields. The tunnelling magneto-resistance (TMR) effect is the relative change in the electrical resistance upon application of a small magnetic field. Tunnel junctions with a TMR effect of 580% at 4 K were reported by the group of Miyazaki and Ando [1], consisting of two Co2MnSi Heusler electrodes. High Curie temperatures were found in Co2 Heusler compounds with values up to 1120 K in Co2FeSi [2]. The latest results are for a TMR device made from the Co2FeAl0.5Si0.5 Heusler compound and working at room temperature with a TMR effect of 174% [3]. The first significant magneto-resistance effect was discovered in Co2Cr0.6Fe0.4Al (CCFA) in Mainz [4]. With the classical Heusler compound CCFA as one electrode, the record TMR effect at 4 K is 240% [5]. Positive and negative TMR values at room temperature utilizing magnetic tunnel junctions with one Heusler compound electrode render magnetic logic possible [6]. Research efforts exist, in particular, in Japan and in Germany. The status of research as of winter 2005 was compiled in a recent special volume of Journal of Physics D: Applied Physics [7-20]. Since then specific progress has been made on the issues of (i) new advanced Heusler materials, (ii) advanced characterization, and (iii) advanced devices using the new materials. In Germany, the Mainz and Kaiserslautern based Research Unit 559 `New Materials with High Spin Polarization', funded since 2004 by the Deutsche Forschungsgemeinschaft, is a basic science approach to Heusler compounds, and it addresses the first two topics in particular

  18. The immobilization of heavy metals in soil by bioaugmentation of a UV-mutant Bacillus subtilis 38 assisted by NovoGro biostimulation and changes of soil microbial community

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ting [MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Urban Transport Emission Control Research Centre, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Sun, Hongwen, E-mail: sunhongwen@nankai.edu.cn [MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Mao, Hongjun [Urban Transport Emission Control Research Centre, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Zhang, Yanfeng; Wang, Cuiping; Zhang, Zhiyuan; Wang, Baolin; Sun, Lei [MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China)

    2014-08-15

    Highlights: • A UV-mutated species, Bacillus subtilis 38, is a good sorbent for multi-metals (Cd, Cr, Hg and Pb). • B38 mixed with NovoGro exhibited a synergetic effect on the immobilization of heavy metals in soil. • DTPA, M3 and BCR were suitable for predicting metal bioavailability for specific classes of plant. • The NovoGro could enhance the proliferation of both exotic B38 and native microbes. • It's a practical strategy for the remediation of actual farmland polluted by multi-heavy metals. - Abstract: Bacillus subtilis 38 (B38) is a mutant species of Bacillus subtilis acquired by UV irradiation with high cadmium tolerance. This study revealed that B38 was a good biosorbent for the adsorption of multiple heavy metals (cadmium, chromium, mercury, and lead). Simultaneous application of B38 and NovoGro (SNB) exhibited a synergetic effect on the immobilization of heavy metals in soil. The heavy metal concentrations in the edible part of the tested plants (lettuce, radish, and soybean) under SNB treatment decreased by 55.4–97.9% compared to the control. Three single extraction methods, diethylenetriaminepentaacetic acid (DTPA), Mehlich 3 (M3), and the first step of the Community Bureau of Reference method (BCR1), showed good predictive capacities for metal bioavailability to leafy, rhizome, and leguminous plant, respectively. The polymerase chain reaction–denaturing gradient gel electrophoresis (PCR–DGGE) profiles revealed that NovoGro could enhance the proliferation of both exotic B38 and native microbes. Finally, the technology was checked in the field, the reduction in heavy metal concentrations in the edible part of radish was in the range between 30.8% and 96.0% after bioremediation by SNB treatment. This study provides a practical strategy for the remediation of farmland contaminated by multiple heavy metals.

  19. The immobilization of heavy metals in soil by bioaugmentation of a UV-mutant Bacillus subtilis 38 assisted by NovoGro biostimulation and changes of soil microbial community

    International Nuclear Information System (INIS)

    Wang, Ting; Sun, Hongwen; Mao, Hongjun; Zhang, Yanfeng; Wang, Cuiping; Zhang, Zhiyuan; Wang, Baolin; Sun, Lei

    2014-01-01

    Highlights: • A UV-mutated species, Bacillus subtilis 38, is a good sorbent for multi-metals (Cd, Cr, Hg and Pb). • B38 mixed with NovoGro exhibited a synergetic effect on the immobilization of heavy metals in soil. • DTPA, M3 and BCR were suitable for predicting metal bioavailability for specific classes of plant. • The NovoGro could enhance the proliferation of both exotic B38 and native microbes. • It's a practical strategy for the remediation of actual farmland polluted by multi-heavy metals. - Abstract: Bacillus subtilis 38 (B38) is a mutant species of Bacillus subtilis acquired by UV irradiation with high cadmium tolerance. This study revealed that B38 was a good biosorbent for the adsorption of multiple heavy metals (cadmium, chromium, mercury, and lead). Simultaneous application of B38 and NovoGro (SNB) exhibited a synergetic effect on the immobilization of heavy metals in soil. The heavy metal concentrations in the edible part of the tested plants (lettuce, radish, and soybean) under SNB treatment decreased by 55.4–97.9% compared to the control. Three single extraction methods, diethylenetriaminepentaacetic acid (DTPA), Mehlich 3 (M3), and the first step of the Community Bureau of Reference method (BCR1), showed good predictive capacities for metal bioavailability to leafy, rhizome, and leguminous plant, respectively. The polymerase chain reaction–denaturing gradient gel electrophoresis (PCR–DGGE) profiles revealed that NovoGro could enhance the proliferation of both exotic B38 and native microbes. Finally, the technology was checked in the field, the reduction in heavy metal concentrations in the edible part of radish was in the range between 30.8% and 96.0% after bioremediation by SNB treatment. This study provides a practical strategy for the remediation of farmland contaminated by multiple heavy metals

  20. Preliminary study for development of low dose radiation shielding material using liquid silicon and metallic compound

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Seo Goo; Lee, Sung Soo [Dept. of Medical Science, Graduate School of Soonchunhyang University, Asan (Korea, Republic of); Han, Su Chul [Div. of Medical Radiation Equipment, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kang, Sung Jin [SoonChunHyang University Hospital, Seoul (Korea, Republic of); Lim, Sung Wook [Graduate school of SeJong University, Seoul (Korea, Republic of)

    2017-09-15

    This study measured and compared the protective clothing using Pb used for shielding in a diagnostic X-ray energy range, and the shielding rates of X-ray fusion shielding materials using Si and TiO{sub 2}. For the experiment, a pad type shielding with a thickness of 1 mm was prepared by mixing Si-TiO{sub 2}, and the X-ray shielding rate was compared with 0.5 mmPb plate of The shielding rate of shielding of 0.5 mmPb plate 95.92%, 85.26 % based on the case of no shielding under each 60kVp, 100kVp tube voltage condition. When the shielding of Si-TiO{sub 2} pad was applied, the shielding rate equal to or greater than 0.5 mmPb plate was obtained at a thickness of 11 mm or more, and the shielding rate of 100% or more was confirmed at a thickness of 13 nn in 60kVp condition. When the shielding of Si-TiO{sub 2} pad was applied, the shielding rate equal to or greater than 0.5 mmPb plate was obtained at a thickness of 17 mm or more, and a shielding rate of 0.5 mmPb plate was observed at a thickness of 23 mm in 100kVp condition. Through the results of this study, We could confirm the possibility of manufacturing radiation protective materials that does not contain lead hazard using various metallic compound and liquid Si. This study shows that possibility of liquid Si and other metallic compound can harmonize easily. Beside, It is flexible and strong to physical stress than Pb obtained radiation protective clothes. But additional studies are needed to increase the shielding rate and reduce the weight.

  1. Cure and mechanical properties of carboxylated nitrile rubber (XNBR) vulcanized by alkaline earth metal compounds

    Science.gov (United States)

    Tulyapitak, Tulyapong

    Compounds of carboxylated nitrile rubber (XNBR) with alkaline metal oxides and hydroxide were prepared, and their cure and mechanical properties were investigated. Magnesium oxide (MgO) with different specific surface areas (45, 65, and 140 m2/g) was used. Increased specific surface area and concentration of MgO resulted in higher cure rate. Optimum stiffness, tensile strength, and ultimate strain required an equimolar amount of acidity and MgO. The effect of specific surface area on tensile properties was not significant. Crosslink density of XNBR-MgO vulcanizates increased with increased amounts of MgO. ATR-IR spectroscopy showed that neutralization occurs in two steps: (1) During mixing and storage, MgO reacts with carboxyl groups (RCOOH) to give RCOOMgOH. (2) Upon curing, these react bimolecularly to form RCOOMgOOCR and Mg(OH)2. Dynamic mechanical thermal analysis revealed an ionic transition at higher temperature, in addition to the glass transition. The ionic transition shifts to higher temperature with increasing MgO concentration. Like MgO-XNBR systems, cure rates of XNBR-calcium hydroxide (Ca(OH)2) and XNBR-barium oxide (BaO) compounds increased with increased content of curing agents. Curing by these two agents resulted in ionic crosslinks. To ensure optimum tensile properties, equimolar amounts of carboxyl groups and curing agents were required. Dynamic mechanical analysis revealed the ionic transition in these two systems. It shifted to higher temperature with increased amounts of curing agents. In contrast to MgO, Ca(OH)2, and BaO, calcium oxide (CaO) gave results similar to those for thermally cured samples. No ionic transition was observed in XNBR-CaO systems. Tensile strength of XNBR depended on the strength of ionic crosslinks, which was dependent on the size of the alkaline metal ions.

  2. Interaction of intermetallic compounds formed by rare earths, scandium, yttrium and 3d-transition metals, with gaseous ammonia

    International Nuclear Information System (INIS)

    Shilkin, S.P.; Volkova, L.S.

    1992-01-01

    Interaction of the RT n intermetallic compounds, where R Sc, Y, rare earths, T = Fe, Co, Ni; n = 2,3,5, with gaseous ammonia under pressure of 1MPa and at temperatures of 293, 723 and 798 K is studied. It is established on the basis of roentgenographic studied, chemical analysis data, X-ray photoelectron spectroscopy and specific surface measurements that metallic matrixes of intermetallides decompose into nitrides and transition metal phases at temperatures of 723 and 798 K under effect of ammonia and independent of structural types of the source materials; partial or complete decomposition of intermetallides through ammonia with formation of transition metal mixture, binary hydrides and nitrides of the most electropositive metal the above systems occurs at the temperature of 293 K depending on the heat of the source compounds and their tendency to decomposition under ammonia effect

  3. Electronic computer prediction of properties of binary refractory transition metal compounds on the base of their simplificated electronic structure

    International Nuclear Information System (INIS)

    Kutolin, S.A.; Kotyukov, V.I.

    1979-01-01

    An attempt is made to obtain calculation equations of macroscopic physico-chemical properties of transition metal refractory compounds (density, melting temperature, Debye characteristic temperature, microhardness, standard formation enthalpy, thermo-emf) using the method of the regression analysis. Apart from the compound composition the argument of the regression equation is the distribution of electron bands of d-transition metals, created by the energy electron distribution in the simplified zone structure of transition metals and approximated by Chebishev polynoms, by the position of Fermi energy on the map of distribution of electron band energy depending upon the value of quasi-impulse, multiple to the first, second and third Brillouin zone for transition metals. The maximum relative error of the regressions obtained as compared with the literary data is 15-20 rel.%

  4. [Evaluation of compounding EDTA and citric acid on remediation of heavy metals contaminated soil].

    Science.gov (United States)

    Yin, Xue; Chen, Jia-Jun; Cai, Wen-Min

    2014-08-01

    As commonly used eluents, Na2EDTA (EDTA) and citric acid (CA) have been widely applied in remediation of soil contaminated by heavy metals. In order to evaluate the removal of arsenic, cadmium, copper, and lead in the contaminated soil collected in a chemical plant by compounding EDTA and CA, a series of stirring experiments were conducted. Furthermore, the changes in speciation distribution of heavy metals before and after washing were studied. The results showed that, adopting the optimal molar ratio of EDTA/CA (1:1), when the pH of the solution was 3, the stirring time was 30 min, the stirring rate was 150 r x min(-1) and the L/S was 5:1, the removal rates of arsenic, cadmium, copper and lead could reach 11.72%, 43.39%, 24.36% and 27.17%, respectively. And it was found that after washing, for arsenic and copper, the content of acid dissolved fraction rose which increased the percentage of available contents. Fe-Mn oxide fraction mainly contributed to the removal of copper. As for cadmium, the percentages of acid dissolved fraction, Fe-Mn oxide fraction and organic fraction also decreased. In practical projects, speciation changes would pose certain environmental risk after soil washing, which should be taken into consideration.

  5. Rare-earth metal compounds with a novel ligand 2-methoxycinnamylidenepyruvate: A thermal and spectroscopic approach

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, C.T., E-mail: claudiocarvalho@ufgd.edu.br [Federal University of Grande Dourados, UFGD, 79.804-970 Dourados, MS (Brazil); Oliveira, G.F. [Federal University of Grande Dourados, UFGD, 79.804-970 Dourados, MS (Brazil); Fernandes, J. [Federal University of Grande Dourados, UFGD, 79.804-970 Dourados, MS (Brazil); Federal University of Mato Grosso, UFMT, 78.060-900 Cuiabá, MT (Brazil); Federal University of Goiás, UFG, 74.690-900, Goiânia, GO (Brazil); Institute of Chemistry, UNESP, 14.801-970 Araraquara, SP (Brazil); Siqueira, A.B. [Federal University of Mato Grosso, UFMT, 78.060-900 Cuiabá, MT (Brazil); Ionashiro, E.Y. [Federal University of Goiás, UFG, 74.690-900, Goiânia, GO (Brazil); Ionashiro, M. [Institute of Chemistry, UNESP, 14.801-970 Araraquara, SP (Brazil)

    2016-08-10

    Highlights: • 2-Methoxycinnamylidenepyruvate as a novel ligand for the synthesis of complexes. • Complexes with well-defined structural arrangements. • Thermal decomposition dependent on the nature of the metal ion. • Study by TG/FT-IR and TG/MS of the gaseous products released. • Potential technological application. - Abstract: Compounds of 2-methoxycinnamylidenepyruvate with trivalent lanthanide ions (Tb, Ho, Er, Tm, Yb and Lu) were obtained in solid state and studied mainly in terms of their thermal and spectroscopic properties. The analyses of the characterization were performed by thermogravimetric system coupled to a mass and infrared spectrometer (TG–DTA/MS and TG–DTA/FT-IR), X-ray powder diffractometry, differential scanning calorimetry (DSC), infrared (FT-IR), preliminary study of fluorescence as well as classical technique of titration with EDTA. From these results, it was possible to establish the stoichiometry, thermal behavior, hydration water content, and the gaseous products released in the thermal decomposition steps, and suggest the type of metal-ligand coordination.

  6. Effects of Metallic Nanoparticles on Interfacial Intermetallic Compounds in Tin-Based Solders for Microelectronic Packaging

    Science.gov (United States)

    Haseeb, A. S. M. A.; Arafat, M. M.; Tay, S. L.; Leong, Y. M.

    2017-10-01

    Tin (Sn)-based solders have established themselves as the main alternative to the traditional lead (Pb)-based solders in many applications. However, the reliability of the Sn-based solders continues to be a concern. In order to make Sn-based solders microstructurally more stable and hence more reliable, researchers are showing great interest in investigating the effects of the incorporation of different nanoparticles into them. This paper gives an overview of the influence of metallic nanoparticles on the characteristics of interfacial intermetallic compounds (IMCs) in Sn-based solder joints on copper substrates during reflow and thermal aging. Nanocomposite solders were prepared by mechanically blending nanoparticles of nickel (Ni), cobalt (Co), zinc (Zn), molybdenum (Mo), manganese (Mn) and titanium (Ti) with Sn-3.8Ag-0.7Cu and Sn-3.5Ag solder pastes. The composite solders were then reflowed and their wetting characteristics and interfacial microstructural evolution were investigated. Through the paste mixing route, Ni, Co, Zn and Mo nanoparticles alter the morphology and thickness of the IMCs in beneficial ways for the performance of solder joints. The thickness of Cu3Sn IMC is decreased with the addition of Ni, Co and Zn nanoparticles. The thickness of total IMC layer is decreased with the addition of Zn and Mo nanoparticles in the solder. The metallic nanoparticles can be divided into two groups. Ni, Co, and Zn nanoparticles undergo reactive dissolution during solder reflow, causing in situ alloying and therefore offering an alternative route of alloy additions to solders. Mo nanoparticles remain intact during reflow and impart their influence as discrete particles. Mechanisms of interactions between different types of metallic nanoparticles and solder are discussed.

  7. A DFT study of volatile organic compounds adsorption on transition metal deposited graphene

    International Nuclear Information System (INIS)

    Kunaseth, Manaschai; Poldorn, Preeyaporn; Junkeaw, Anchalee; Meeprasert, Jittima; Rungnim, Chompoonut; Namuangruk, Supawadee; Kungwan, Nawee; Inntam, Chan; Jungsuttiwong, Siriporn

    2017-01-01

    Highlights: • VOCs removal via modified carbon-based adsorbent using density functional theory. • The single-vacancy defective graphene (SDG) with metal-deposited significantly increase the adsorption efficiency. • TM-doped SDG is a suitable adsorbent material for VOC removal. • Electron in hybridized sp"2-orbitals of heteroatoms has an effect on mode of adsorption. - Abstract: Recently, elevated global emission of volatile organic compounds (VOCs) was associated to the acceleration and increasing severity of climate change worldwide. In this work, we investigated the performance of VOCs removal via modified carbon-based adsorbent using density functional theory. Here, four transition metals (TMs) including Pd, Pt, Ag, and Au were deposited onto single-vacancy defective graphene (SDG) surface to increase the adsorption efficiency. Five prototypical VOCs including benzene, furan, pyrrole, pyridine, and thiophene were used to study the adsorption capability of metal-deposited graphene adsorbent. Calculation results revealed that Pd, Pt, Au, and Ag atoms and nanoclusters bind strongly onto the SDG surface. In this study, benzene, furan and pyrrole bind in the π-interaction mode using delocalized π-electron in aromatic ring, while pyridine and thiophene favor X- interaction mode, donating lone pair electron from heteroatom. In terms of adsorption, pyridine VOC adsorption strengths to the TM-cluster doped SDG surfaces are Pt_4 (−2.11 eV) > Pd_4 (−2.05 eV) > Ag_4 (−1.53 eV) > Au_4 (−1.87 eV). Our findings indicate that TM-doped SDG is a suitable adsorbent material for VOC removal. In addition, partial density of states analysis suggests that benzene, furan, and pyrrole interactions with TM cluster are based on p-orbitals of carbon atoms, while pyridine and thiophene interactions are facilitated by hybridized sp"2-orbitals of heteroatoms. This work provides a key insight into the fundamentals of VOCs adsorption on carbon-based adsorbent.

  8. Serum heavy metals and hemoglobin related compounds in Saudi Arabia firefighters

    Directory of Open Access Journals (Sweden)

    Al-Malki Abdulrahman L

    2009-07-01

    Full Text Available Abstract Background Firefighters are frequently exposed to significant concentrations of hazardous materials including heavy metals, aldehydes, hydrogen chloride, dichlorofluoromethane and some particulates. Many of these materials have been implicated in the triggering of several diseases. The aim of the present study is to investigate the effect of fire smoke exposure on serum heavy metals and possible affection on iron functions compounds (total iron binding capacity, transferrin saturation percent, ferritin, unsaturated iron-binding capacity blood hemoglobin and carboxyhemoglobin,. Subjects and methods Two groups of male firefighter volunteers were included; the first included 28 firefighters from Jeddah city, while the second included 21 firefighters from Yanbu city with an overall age rang of 20–48 years. An additional group of 23 male non-firefighters volunteered from both cities as normal control subjects. Blood samples were collected from all volunteer subjects and investigated for relevant parameters. Results The results obtained showed that there were no statistically significant changes in the levels of serum heavy metals in firefighters as compared to normal control subjects. Blood carboxyhemoglobin and serum ferritin were statistically increased in Jeddah firefighters, (p Conclusion Such results might point to the need for more health protective and prophylactic measures to avoid such hazardous health effects (elevated Blood carboxyhemoglobin and serum ferritin and decreased serum TIBC and UIBC that might endanger firefighters working under dangerous conditions. Firefighters must be under regular medical follow-up through standard timetabled medical laboratory investigations to allow for early detection of any serum biochemical or blood hematological changes.

  9. Contaminant immobilization via microbial activity

    International Nuclear Information System (INIS)

    1991-11-01

    The aim of this study was to search the literature to identify biological techniques that could be applied to the restoration of contaminated groundwaters near uranium milling sites. Through bioremediation it was hypothesized that the hazardous heavy metals could be immobilized in a stable, low-solubility form, thereby halting their progress in the migrating groundwater. Three basic mechanisms were examined: reduction of heavy metals by microbially produced hydrogen sulfide; direct microbial mediated reduction; and biosorption

  10. New polymer-supported ion-complexing agents: Design, preparation and metal ion affinities of immobilized ligands

    International Nuclear Information System (INIS)

    Alexandratos, Spiro D.

    2007-01-01

    Polymer-supported reagents are comprised of crosslinked polymer networks that have been modified with ligands capable of selective metal ion complexation. Applications of these polymers are in environmental remediation, ion chromatography, sensor technology, and hydrometallurgy. Bifunctional polymers with diphosphonate/sulfonate ligands have a high selectivity for actinide ions. The distribution coefficient for the uranyl ion from 1 M nitric acid is 70,000, compared to 900 for the monophosphonate/sulfonate polymer and 200 for the sulfonic acid ion-exchange resin. A bifunctional trihexyl/triethylammonium polymer has a high affinity and selectivity for pertechnetate and perchlorate anions from groundwater. In one example, its distribution coefficient for perchlorate ions in the presence of competing anions is 3,300,000, compared to 203,180 for a commercially available anion-exchange resin. Polystyrene modified with N-methyl-D-glucamine ligands is capable of selectively complexing arsenate from groundwater. It complexes 99% of the arsenate present in a solution of 100 mg/L arsenate with 560 mg/L sulfate ions. Its selectivity is retained even in the presence of 400 mg/L phosphate. There is no affinity for arsenate above pH 9, allowing for the polymer to be regenerated with moderate alkali solution. In studies aimed at developing a Hg(II)-selective resin, simple amine resins were found to have a high Hg(II) affinity and that affinity is dependent upon the solution pH and the counterion

  11. Immobilizing Organic-Based Molecular Switches into Metal-Organic Frameworks: A Promising Strategy for Switching in Solid State.

    Science.gov (United States)

    Gui, Bo; Meng, Yi; Xie, Yang; Du, Ke; Sue, Andrew C-H; Wang, Cheng

    2018-01-01

    Organic-based molecular switches (OMS) are essential components for the ultimate miniaturization of nanoscale electronics and devices. For practical applications, it is often necessary for OMS to be incorporated into functional solid-state materials. However, the switching characteristics of OMS in solution are usually not transferrable to the solid state, presumably because of spatial confinement or inefficient conversion in densely packed solid phase. A promising way to circumvent this issue is harboring the functional OMS within the robust and porous environment of metal-organic frameworks (MOFs) as their organic components. In this feature article, recent research progress of OMS-based MOFs is briefly summarized. The switching behaviors of OMS under different stimuli (e.g., light, redox, pH, etc.) in the MOF state are first introduced. After that, the technological applications of these OMS-based MOFs in different areas, including CO 2 adsorption, gas separation, drug delivery, photodynamic therapy, and sensing, are outlined. Finally, perspectives and future challenges are discussed in the conclusion. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Immobilized fluid membranes for gas separation

    Science.gov (United States)

    Liu, Wei; Canfield, Nathan L; Zhang, Jian; Li, Xiaohong Shari; Zhang, Jiguang

    2014-03-18

    Provided herein are immobilized liquid membranes for gas separation, methods of preparing such membranes and uses thereof. In one example, the immobilized membrane includes a porous metallic host matrix and an immobilized liquid fluid (such as a silicone oil) that is immobilized within one or more pores included within the porous metallic host matrix. The immobilized liquid membrane is capable of selective permeation of one type of molecule (such as oxygen) over another type of molecule (such as water). In some examples, the selective membrane is incorporated into a device to supply oxygen from ambient air to the device for electrochemical reactions, and at the same time, to block water penetration and electrolyte loss from the device.

  13. Metal electrodeposition and electron transfer studies of uranium compounds in room temperature ionic liquids

    International Nuclear Information System (INIS)

    Stoll, M.E.; Oldham, W.J.; Costa, D.A.

    2004-01-01

    electrochemical methods including cyclic and square-wave voltammetry, chronoamperometry, and bulk coulometry. Results from these studies will be presented to show the general electron transfer behavior of metal complexes in the RTIL's. As an example, Figure 2 shows the difference in chemical stability of an electrogenerated U(V) anion for two uranyl (U(VI)O 2 2+ ) complexes due to the difference in ancillary ligands about the uranyl moiety. Figure 2a shows a cyclic voltammogram (CV) for the U(VI)/U(V) couple of a uranyl complex containing a multi-dentate chelating nitrogen/oxygen ligand (inset in figure). The couple is both chemically and electrochemically reversible. The CV in Figure 2b is that of [UO 2 Cl 4 ] 2- in which the electrogenerated U(V) derivative is unstable yielding a chemically irreversible wave. For the compound giving rise to the CV in Figure 2a its electrochemical behavior in a conventional nonaqueous electrolyte medium is very similar to that obtained in the RTIL. While this result does not illustrate a distinct advantage for employing the RTIL solvent in this particular case, we believe it effectively demonstrates the ability of the RTIL to be utilized as a solvent/electrolyte medium for detailed electrochemical studies without severe limitations.

  14. Airborne Release of Particles in Overheating Incidents Involving Plutonium Metal and Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Schwendiman, L. C.; Mishima, J.; Radasch, C. A. [Battelle Memorial Institute, Pacific Northwest Laboratory, Richland, WA (United States)

    1968-12-15

    Ever-increasing utilization of nuclear fuels will result in wide-scale plutonium recovery processing, reconstitution of fuels, transportation, and extensive handling of this material. A variety of circumstances resulting in overheating and fires involving plutonium may occur, releasing airborne particles. This work describes the observations from a study in which the airborne release of plutonium and its compounds was measured during an exposure of the material of interest containing plutonium to temperatures which may result from fires. Aerosol released from small cylinders of metallic plutonium ignited in air at temperatures from 410 to 650 Degree-Sign C ranged from 3 x 10{sup -6} to 5 x 10{sup -5} wt%. Particles smaller than 15{mu}m in diameter represented as much as 0.03% of the total released. Large plutonium pieces weighing from 456 to 1770 g were ignited and allowed to oxidize completely in air with a velocity of around 500 cm/sec. Release rates of from 0.0045 to 0.032 wt% per hour were found. The median mass diameter of airborne material was 4 {mu}m. Quenching the oxidation with magnesium oxide sand reduced the release to 2.9 X 10{sup -4} wt% per hour. Many experiments were carried out in which plutonium compounds as powders were heated at temperatures ranging from 700 to 1000 Degree-Sign C with several air flows. Release rates ranged from 5 x 10{sup -8} to 0.9 wt% per hour, depending upon the compound and the conditions imposed. The airborne release from boiling solutions of plutonium nitrate were roughly related to energy of boiling, and ranged from 4 x 10{sup -4} to 2 x 10{sup -1} % for the evaporation of 90% of the solution. The fraction airborne when combustibles contaminated with plutonium are burned is under study. The data reported can be used in assessing the consequences of off-standard situations involving plutonium and its compounds in fires. (author)

  15. Potential use of lime combined with additives on (im)mobilization and phytoavailability of heavy metals from Pb/Zn smelter contaminated soils.

    Science.gov (United States)

    Hussain Lahori, Altaf; Zhang, Zengqiang; Guo, Zhanyu; Mahar, Amanullah; Li, Ronghua; Kumar Awasthi, Mukesh; Ali Sial, Tanveer; Kumbhar, Farhana; Wang, Ping; Shen, Feng; Zhao, Junchao; Huang, Hui

    2017-11-01

    This explorative study was aimed to assess the efficiency of lime alone and in combined with additives to immobilize Pb, Cd, Cu and Zn in soil and reduce their phytoavailability for plant. A greenhouse pot experiment was performed by using low and heavily contaminated top soils viz. Tongguan contaminated (TG-C); Fengxian heavily contaminated (FX-HC) and Fengxian low contaminated (FX-LC). The contaminated soils were treated with lime (L) alone and in combined with Ca-bentonite (CB), Tobacco biochar (TB) and Zeolite (Z) at 1% and cultivated by Chinese cabbage (Brassica campestris L). Results revealed that all amendments (plime alone and in combined with additives were drastically decreased the dry biomass yield of Brassica campestris L. as compared with control. Thus, these feasible amendments potentially maximum reduced the uptake by plant shoots upto Pb 53.47 and Zn 67.93% with L+Z and L+TB in FX-LC soil, while Cd 68.58 and Cu 60.29% with L+TB, L+CB in TG-C soil but Cu uptake in plant shoot was observed 27.26% and 30.17% amended with L+TB and L+Z in FX-HC and FX-LC soils. On the other hand, these amendments were effectively reduced the potentially toxic metals (PTMs) in roots upto Pb77.77% L alone in FX-HC, Cd 96.76% with L+TB in TG-C, while, Cu 66.70 and Zn 60.18% with L+Z in FX-LC. Meanwhile, all amendments were responsible for increasing soil pH and CEC but decreased soils EC level. Based on this result, these feasible soil amendments were recommended for long term-study under field condition to see the response of another hyper accumulator crop. Copyright © 2017. Published by Elsevier Inc.

  16. Metaproteomics Identifies the Protein Machinery Involved in Metal and Radionuclide Reduction in Subsurface Microbiomes and Elucidates Mechanisms and U(VI) Reduction Immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Pfiffner, Susan M. [Univ. of Tennessee, Knoxville, TN (United States); Löffler, Frank [Univ. of Tennessee, Knoxville, TN (United States); Ritalahti, Kirsti [Univ. of Tennessee, Knoxville, TN (United States); Sayler, Gary [Univ. of Tennessee, Knoxville, TN (United States); Layton, Alice [Univ. of Tennessee, Knoxville, TN (United States); Hettich, Robert [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-08-31

    The overall goal for this funded project was to develop and exploit environmental metaproteomics tools to identify biomarkers for monitoring microbial activity affecting U speciation at U-contaminated sites, correlate metaproteomics profiles with geochemical parameters and U(VI) reduction activity (or lack thereof), elucidate mechanisms contributing to U(VI) reduction, and provide remediation project managers with additional information to make science-based site management decisions for achieving cleanup goals more efficiently. Although significant progress has been made in elucidating the microbiology contribution to metal and radionuclide reduction, the cellular components, pathway(s), and mechanisms involved in U trans-formation remain poorly understood. Recent advances in (meta)proteomics technology enable detailed studies of complex samples, including environmental samples, which differ between sites and even show considerable variability within the same site (e.g., the Oak Ridge IFRC site). Additionally, site-specific geochemical conditions affect microbial activity and function, suggesting generalized assessment and interpretations may not suffice. This research effort integrated current understanding of the microbiology and biochemistry of U(VI) reduction and capitalize on advances in proteomics technology made over the past few years. Field-related analyses used Oak Ridge IFRC field ground water samples from locations where slow-release substrate biostimulation has been implemented to accelerate in situ U(VI) reduction rates. Our overarching hypothesis was that the metabolic signature in environmental samples, as deciphered by the metaproteome measurements, would show a relationship with U(VI) reduction activity. Since metaproteomic and metagenomic characterizations were computationally challenging and time-consuming, we used a tiered approach that combines database mining, controlled laboratory studies, U(VI) reduction activity measurements, phylogenetic

  17. Bioavailability of Heavy Metals in Soil: Impact on Microbial Biodegradation of Organic Compounds and Possible Improvement Strategies

    Science.gov (United States)

    Olaniran, Ademola O.; Balgobind, Adhika; Pillay, Balakrishna

    2013-01-01

    Co-contamination of the environment with toxic chlorinated organic and heavy metal pollutants is one of the major problems facing industrialized nations today. Heavy metals may inhibit biodegradation of chlorinated organics by interacting with enzymes directly involved in biodegradation or those involved in general metabolism. Predictions of metal toxicity effects on organic pollutant biodegradation in co-contaminated soil and water environments is difficult since heavy metals may be present in a variety of chemical and physical forms. Recent advances in bioremediation of co-contaminated environments have focussed on the use of metal-resistant bacteria (cell and gene bioaugmentation), treatment amendments, clay minerals and chelating agents to reduce bioavailable heavy metal concentrations. Phytoremediation has also shown promise as an emerging alternative clean-up technology for co-contaminated environments. However, despite various investigations, in both aerobic and anaerobic systems, demonstrating that metal toxicity hampers the biodegradation of the organic component, a paucity of information exists in this area of research. Therefore, in this review, we discuss the problems associated with the degradation of chlorinated organics in co-contaminated environments, owing to metal toxicity and shed light on possible improvement strategies for effective bioremediation of sites co-contaminated with chlorinated organic compounds and heavy metals. PMID:23676353

  18. Bioavailability of Heavy Metals in Soil: Impact on Microbial Biodegradation of Organic Compounds and Possible Improvement Strategies

    Directory of Open Access Journals (Sweden)

    Balakrishna Pillay

    2013-05-01

    Full Text Available Co-contamination of the environment with toxic chlorinated organic and heavy metal pollutants is one of the major problems facing industrialized nations today. Heavy metals may inhibit biodegradation of chlorinated organics by interacting with enzymes directly involved in biodegradation or those involved in general metabolism. Predictions of metal toxicity effects on organic pollutant biodegradation in co-contaminated soil and water environments is difficult since heavy metals may be present in a variety of chemical and physical forms. Recent advances in bioremediation of co-contaminated environments have focussed on the use of metal-resistant bacteria (cell and gene bioaugmentation, treatment amendments, clay minerals and chelating agents to reduce bioavailable heavy metal concentrations. Phytoremediation has also shown promise as an emerging alternative clean-up technology for co-contaminated environments. However, despite various investigations, in both aerobic and anaerobic systems, demonstrating that metal toxicity hampers the biodegradation of the organic component, a paucity of information exists in this area of research. Therefore, in this review, we discuss the problems associated with the degradation of chlorinated organics in co-contaminated environments, owing to metal toxicity and shed light on possible improvement strategies for effective bioremediation of sites co-contaminated with chlorinated organic compounds and heavy metals.

  19. Final Technical Report: Role of Methanotrophs in Metal Mobilization, Metal Immobilization and Mineral Weathering: Effects on the In Situ Microbial Community and the Sustainability of Subsurface Water Systems

    Energy Technology Data Exchange (ETDEWEB)

    Semrau, Jeremy D. [Univ. of Michigan, Ann Arbor, MI (United States); DiSpirito, Alan A. [Iowa State Univ., Ames, IA (United States)

    2016-11-06

    Activities from this DOE sponsored project can be divided into four broad areas: (1) investigations into the potential of methanobactin, a biogenic metal-binding agent produced by methanotrophs, in mitigating mercury toxicity; (2) elucidation of the genetic basis for methanobactin synthesis from methanotrophs; (3) examination of differential gene expression of M. trichosporium OB3b when grown in the presence of varying amounts of copper and/or cerium, and (4) collection and characterization of soil cores from Savannah River Test Site to determine the ubiquity of methanobactin producing methanotrophs. From these efforts, we have conclusively shown that methanobactin can strongly bind mercury as Hg[II], and in so doing significantly reduce the toxicity of this metal to microbes. Further, we have deduced the genetic basis of methanobactin production in methanotrophs, enabling us to construct mutants such that we can now ascribe function to different genes as well as propose a pathway for methanobactin biosynthesis. We have also clear evidence that copper and cerium (as an example of a rare earth element) dramatically affect gene expression in methanotrophs, and thus have an important impact on the activity and application of these microbes to a variety of environmental and industrial issues. Finally, we successfully isolated one methanotroph from the deep subsurface of the Savannah River Test Site and characterized the ability of different forms of methanobactin to mobilize copper and mercury from these soils.

  20. Comprehensive uranium thiophosphate chemistry: Framework compounds based on pseudotetrahedrally coordinated central metal atoms

    International Nuclear Information System (INIS)

    Neuhausen, Christine; Panthoefer, Martin; Tremel, Wolfgang; Hatscher, Stephan T.; Urland, Werner

    2013-01-01

    The new ternary compounds UP 2 S 6 , UP 2 S 7 , U(P 2 S 6 ) 2 , and U 3 (PS 4 ) 4 were prepared from uranium metal, phosphorus pentasulfide, and sulfur at 700 C. The crystal structures were determined by single-crystal X-ray diffraction methods. UP 2 S 6 (I) crystallizes in the ZrP 2 S 6 structure type [tetragonal, P4 2 /m, a = 6.8058(7) Aa, c = 9.7597(14) Aa, Z = 2], which consists of central uranium(IV) atoms coordinated by P 2 S 6 4- anions (staggered conformation). The anions are two-dimensional connectors for four uranium cations arranged in one plane. The structure of UP 2 S 7 (II) [orthorhombic, Fddd, a = 8.9966(15) Aa, b = 15.2869(2) Aa, c = 30.3195(5) Aa, Z = 16] is closely related to the monoclinic ZrP 2 S 7 structure type. It consists of U 4+ cations linked by P 2 S 7 4- ligands, the resulting 3D network contains large pores (diameter approx. 3.5 x 16.7 Aa). In the previously reported compound U(P 2 S 6 ) 2 (III) [I4 1 /a, a = 12.8776(9) Aa, c = 9.8367(10) Aa, Z = 2], the metal atoms are coordinated by four bidentate P 2 S 6 2- ligands. This arrangement can be considered as a pseudotetrahedral coordination of the uranium atoms by the linear ligands. Three of the resulting diamondoid frameworks are inseparably interwoven in order to optimize space filling. U 3 (PS 4 ) 4 (IV) [I4 1 /acd, a = 10.7440(9) Aa, c = 19.0969(2) Aa, Z = 2] crystallizes in a defect variant of the PrPS 4 structure type, with 50 % of the U2 sites statistically occupied with uranium atoms. The resulting stoichiometry is U 3 (PS 4 ) 4 with tetravalent uranium atoms. The structure of U 3 (PS 4 ) 4 consists of uranium atoms connected by PS 4 3- groups, each PS 4 group linking four central uranium atoms. Vibrational spectra, which were recorded for I-III, show good agreement between the obtained results and the expected values for the anionic units, while magnetic measurements confirm the presence of tetravalent uranium. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGa

  1. Synthesis and characterization of porous metal oxides and desulfurization studies of sulfur containing compounds

    Science.gov (United States)

    Garces Trujillo, Hector Fabian

    This thesis contains two parts: 1) synthesis and characterization of porous metal oxides that include zinc oxide and a porous mixed-valent manganese oxide with an amorphous structure (AMO) 2) the desulfurization studies for the removal of sulfur compounds. Zinc oxide with different nano-scale morphologies may result in various porosities with different adsorption capabilities. A tunable shape microwave synthesis of ZnO nano-spheres in a co-solvent mixture is presented. The ZnO nano-sphere material is investigated as a desulfurizing sorbent in a fixed bed reactor in the temperature range 200 to 400 °C and compared with ZnO nanorods and platelet-like morphologies. Fresh and sulfided materials were characterized by X-ray diffraction (XRD), BET specific surface area, pore volume, scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (SEM/EDX), Raman spectroscopy, and thermogravimetric analysis (TGA). The tunable shape microwave synthesis of ZnO presents a high sulfur sorption capacity at temperatures as low as 200 °C which accounts for a three and four fold enhancement over the other preparations presented in this work, and reached 76 % of the theoretical sulfur capacity (TSC) at 300 °C. Another ZnO material with a bimodal micro- and mesopore size distribution investigated as a desulfurizing sorbent presents a sorption capacity that reaches 87% of the theoretical value for desulfurization at 400 °C at breakthrough time. A deactivation model that considers the activity of the solid reactant was used to fit the experimental data. Good agreement between the experimental breakthrough curves and the model predictions are obtained. Manganese oxides are a type of metal oxide materials commonly used in catalytic applications. Little is known about the adsorption capabilities for the removal of sulfur compounds. One of these manganese oxides; amorphous manganese oxide (AMO) is highly promising material for low temperature sorption processes. Amorphous

  2. Flexible metal-organic framework compounds: In situ studies for selective CO{sub 2} capture

    Energy Technology Data Exchange (ETDEWEB)

    Allen, A.J., E-mail: andrew.allen@nist.gov [Material Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899-8520 (United States); Espinal, L.; Wong-Ng, W. [Material Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899-8520 (United States); Queen, W.L. [NIST Center for Neutron Research, Gaithersburg, MD 20899-6102 (United States); The Molecular Foundry, Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA 94720 (United States); Brown, C.M. [NIST Center for Neutron Research, Gaithersburg, MD 20899-6102 (United States); Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716 (United States); Kline, S.R. [NIST Center for Neutron Research, Gaithersburg, MD 20899-6102 (United States); Kauffman, K.L. [National Energy Technology Laboratory (NETL), US Department of Energy, Pittsburgh, PA 15236 (United States); Culp, J.T. [National Energy Technology Laboratory (NETL), US Department of Energy, Pittsburgh, PA 15236 (United States); URS Corporation, South Park, PA 15219 (United States); Matranga, C. [National Energy Technology Laboratory (NETL), US Department of Energy, Pittsburgh, PA 15236 (United States)

    2015-10-25

    Results are presented that explore the dynamic structural changes occurring in two highly flexible nanocrystalline metal-organic framework (MOF) compounds during the adsorption and desorption of pure gases and binary mixtures. The Ni(1,2-bis(4-pyridyl)ethylene)[Ni(CN){sub 4}] and catena-bis(dibenzoylmethanato)-(4,4′-bipyridyl)nickel(II) chosen for this study are 3-D and 1-D porous coordination polymers (PCP) with a similar gate opening pressure response for CO{sub 2} isotherms at 303 K, but with differing degrees of flexibility for structural change to accommodate guest molecules. As such, they serve as a potential model system for evaluating the complex kinetics associated with dynamic structure changes occurring in response to gas adsorption in flexible MOF systems. Insights into the crystallographic changes occurring as the MOF pore structure expands and contracts in response to interactions with CO{sub 2}, N{sub 2}, and CO{sub 2}/N{sub 2} mixtures have been obtained from in situ small-angle neutron scattering and neutron diffraction, combined with ex situ X-ray diffraction structure measurements. The role of structure in carbon capture functionality is discussed with reference to the ongoing characterization challenges and a possible materials-by-design approach. - Graphical abstract: We present in situ small-angle neutron scattering results for two flexible metal-organic frameworks (MOFs). The figure shows that for one (NiBpene, high CO{sub 2} adsorption) the intensity of the Bragg peak for the expandable d-spacing most associated with CO{sub 2} adsorption varies approximately with the isotherm, while for the other (NiDBM-Bpy, high CO{sub 2} selectivity) the d-spacing, itself, varies with the isotherm. The cartoons show the proposed modes of structural change. - Highlights: • Dynamic structures of two flexible MOF CO{sub 2} sorbent compounds are compared in situ. • These porous solid sorbents serve as models for pure & dual gas adsorption. • Different

  3. NMR shielding calculations across the periodic table: diamagnetic uranium compounds. 2. Ligand and metal NMR.

    Science.gov (United States)

    Schreckenbach, Georg

    2002-12-16

    In this and a previous article (J. Phys. Chem. A 2000, 104, 8244), the range of application for relativistic density functional theory (DFT) is extended to the calculation of nuclear magnetic resonance (NMR) shieldings and chemical shifts in diamagnetic actinide compounds. Two relativistic DFT methods are used, ZORA ("zeroth-order regular approximation") and the quasirelativistic (QR) method. In the given second paper, NMR shieldings and chemical shifts are calculated and discussed for a wide range of compounds. The molecules studied comprise uranyl complexes, [UO(2)L(n)](+/-)(q); UF(6); inorganic UF(6) derivatives, UF(6-n)Cl(n), n = 0-6; and organometallic UF(6) derivatives, UF(6-n)(OCH(3))(n), n = 0-5. Uranyl complexes include [UO(2)F(4)](2-), [UO(2)Cl(4)](2-), [UO(2)(OH)(4)](2-), [UO(2)(CO(3))(3)](4-), and [UO(2)(H(2)O)(5)](2+). For the ligand NMR, moderate (e.g., (19)F NMR chemical shifts in UF(6-n)Cl(n)) to excellent agreement [e.g., (19)F chemical shift tensor in UF(6) or (1)H NMR in UF(6-n)(OCH(3))(n)] has been found between theory and experiment. The methods have been used to calculate the experimentally unknown (235)U NMR chemical shifts. A large chemical shift range of at least 21,000 ppm has been predicted for the (235)U nucleus. ZORA spin-orbit appears to be the most accurate method for predicting actinide metal chemical shifts. Trends in the (235)U NMR chemical shifts of UF(6-n)L(n) molecules are analyzed and explained in terms of the calculated electronic structure. It is argued that the energy separation and interaction between occupied and virtual orbitals with f-character are the determining factors.

  4. Immobilization of heavy metal ions (CuII, CdII, NiII, and PbII) by broiler litter-derived biochars in water and soil

    Science.gov (United States)

    Chars, a form of environmental black carbon resulting from incomplete burning of biomass, can immobilize organic contaminants by both surface adsorption and partitioning mechanisms. The predominance of each sorption mechanism depends upon the proportion of organic to carbonized fractions comprising...

  5. [PHEMA/PEI]–Cu(II) based immobilized metal affinity chromatography cryogels: Application on the separation of IgG from human plasma

    Energy Technology Data Exchange (ETDEWEB)

    Bakhshpour, Monireh; Derazshamshir, Ali; Bereli, Nilay [Department of Chemistry, Biochemistry Division, Hacettepe University, Ankara (Turkey); Elkak, Assem [Laboratory of “Valorisation des Ressources Naturelles et Produits de Santé (VRNPS)”, Doctoral School of Sciences and Technology, Lebanese University, Rafic Hariri University Campus, Hadath (Lebanon); Denizli, Adil, E-mail: denizli@hacettepe.edu [Department of Chemistry, Biochemistry Division, Hacettepe University, Ankara (Turkey)

    2016-04-01

    The immobilized metal-affinity chromatography (IMAC) has gained significant interest as a widespread separation and purification tool for therapeutic proteins, nucleic acids and other biological molecules. The enormous potential of IMAC for proteins with natural surface exposed-histidine residues and for recombinant proteins with histidine clusters. Cryogels as monolithic materials have recently been proposed as promising chromatographic adsorbents for the separation of biomolecules in downstream processing. In the present study, IMAC cryogels have been synthesized and utilized for the adsorption and separation of immunoglobulin G (IgG) from IgG solution and whole human plasma. For this purpose, Cu(II)-ions were coupled to poly(hydroxyethyl methacrylate) PHEMA using poly(ethylene imine) (PEI) as the chelating ligand. In this study the cryogels formation optimized by the varied proportion of PEI from 1% to 15% along with different amounts of Cu (II) as chelating metal. The prepared cryogels were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The [PHEMA/PEI]–Cu(II) cryogels were assayed for their capability to bind the human IgG from aqueous solutions. The IMAC cryogels were found to have high affinity toward human IgG. The adsorption of human IgG was investigated onto the PHEMA/PEI cryogels with (10% PEI) and the concentration of Cu (II) varied as 10, 50, 100 and 150 mg/L. The separation of human IgG was achieved in one purification step at pH 7.4. The maximum adsorption capacity was observed at the [PHEMA/PEI]–Cu(II) (10% PEI) with 72.28 mg/g of human IgG. The purification efficiency and human IgG purity were investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). - Highlights: • Cu(II)-ions were coupled to PHEMA using PEI as the chelating ligand. • Cu(II) chelated [PHEMA/PEI] cryogels for IgG separation were produced. • Maximum IgG adsorption capacity

  6. [PHEMA/PEI]–Cu(II) based immobilized metal affinity chromatography cryogels: Application on the separation of IgG from human plasma

    International Nuclear Information System (INIS)

    Bakhshpour, Monireh; Derazshamshir, Ali; Bereli, Nilay; Elkak, Assem; Denizli, Adil

    2016-01-01

    The immobilized metal-affinity chromatography (IMAC) has gained significant interest as a widespread separation and purification tool for therapeutic proteins, nucleic acids and other biological molecules. The enormous potential of IMAC for proteins with natural surface exposed-histidine residues and for recombinant proteins with histidine clusters. Cryogels as monolithic materials have recently been proposed as promising chromatographic adsorbents for the separation of biomolecules in downstream processing. In the present study, IMAC cryogels have been synthesized and utilized for the adsorption and separation of immunoglobulin G (IgG) from IgG solution and whole human plasma. For this purpose, Cu(II)-ions were coupled to poly(hydroxyethyl methacrylate) PHEMA using poly(ethylene imine) (PEI) as the chelating ligand. In this study the cryogels formation optimized by the varied proportion of PEI from 1% to 15% along with different amounts of Cu (II) as chelating metal. The prepared cryogels were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The [PHEMA/PEI]–Cu(II) cryogels were assayed for their capability to bind the human IgG from aqueous solutions. The IMAC cryogels were found to have high affinity toward human IgG. The adsorption of human IgG was investigated onto the PHEMA/PEI cryogels with (10% PEI) and the concentration of Cu (II) varied as 10, 50, 100 and 150 mg/L. The separation of human IgG was achieved in one purification step at pH 7.4. The maximum adsorption capacity was observed at the [PHEMA/PEI]–Cu(II) (10% PEI) with 72.28 mg/g of human IgG. The purification efficiency and human IgG purity were investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). - Highlights: • Cu(II)-ions were coupled to PHEMA using PEI as the chelating ligand. • Cu(II) chelated [PHEMA/PEI] cryogels for IgG separation were produced. • Maximum IgG adsorption capacity

  7. Absorption characteristics of compound heavy metals vanadium, chromium, and cadmium in water by emergent macrophytes and its combinations.

    Science.gov (United States)

    Lin, Hai; Liu, Junfei; Dong, Yingbo; Ren, Kaiqiang; Zhang, Yu

    2018-04-20

    The aim of the present study was to investigate three kinds of emergent macrophytes, i.e., Acorus calamus L., Phragmites communis Trin., and Alternanthera philoxeroides (Mart.) Griseb and their combination patterns on their removal efficiency of compound heavy metals (vanadium, chromium, and cadmium) from synthetic aqueous. The results showed that the optimal single-species for compound heavy metals removal was Acorus calamus L. and during experiment period, the average removal efficiency of V 5+ , Cr 6+ , and Cd 2+ was 52.4, 46.8, and 90.0%, respectively. Combination C (the quality ratio of Acorus calamus L., Phragmites communis Trin., and Alternanthera philoxeroides (Mart.) Griseb is 2:1:1) had the highest removal efficiency on compound heavy metals among three groups and the average removal efficiency of V 5+ , Cr 6+ , and Cd 2+ was 18.0, 70.0, and 95.1%, respectively. The highest efficiency of combination C on V 5+ removal was lower than single Alternanthera philoxeroides (Mart.) Griseb group; this may be an existing antagonism in different plants. Heavy metals of V 5+ , Cr 6+ , and Cd 2+ had an obviously positive effect on SOD, CAT, and POD of emergent macrophytes. From these results, we conclude that in a phytoremediation for the removal of compound heavy metals where V was dominated pollution in water, the use of Acorus calamus L. species rather than a mixture of several plants should be suggested. When heavy metal pollution was dominated by Cr and Cd, group C rather than a single plant species should be used.

  8. A DFT study of volatile organic compounds adsorption on transition metal deposited graphene

    Energy Technology Data Exchange (ETDEWEB)

    Kunaseth, Manaschai, E-mail: manaschai@nanotec.or.th [Nanoscale Simulation Laboratory, National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120 (Thailand); Poldorn, Preeyaporn [Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190 (Thailand); Junkeaw, Anchalee; Meeprasert, Jittima; Rungnim, Chompoonut; Namuangruk, Supawadee [Nanoscale Simulation Laboratory, National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120 (Thailand); Kungwan, Nawee [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Inntam, Chan [Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190 (Thailand); Jungsuttiwong, Siriporn, E-mail: siriporn.j@ubu.ac.th [Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190 (Thailand)

    2017-02-28

    Highlights: • VOCs removal via modified carbon-based adsorbent using density functional theory. • The single-vacancy defective graphene (SDG) with metal-deposited significantly increase the adsorption efficiency. • TM-doped SDG is a suitable adsorbent material for VOC removal. • Electron in hybridized sp{sup 2}-orbitals of heteroatoms has an effect on mode of adsorption. - Abstract: Recently, elevated global emission of volatile organic compounds (VOCs) was associated to the acceleration and increasing severity of climate change worldwide. In this work, we investigated the performance of VOCs removal via modified carbon-based adsorbent using density functional theory. Here, four transition metals (TMs) including Pd, Pt, Ag, and Au were deposited onto single-vacancy defective graphene (SDG) surface to increase the adsorption efficiency. Five prototypical VOCs including benzene, furan, pyrrole, pyridine, and thiophene were used to study the adsorption capability of metal-deposited graphene adsorbent. Calculation results revealed that Pd, Pt, Au, and Ag atoms and nanoclusters bind strongly onto the SDG surface. In this study, benzene, furan and pyrrole bind in the π-interaction mode using delocalized π-electron in aromatic ring, while pyridine and thiophene favor X- interaction mode, donating lone pair electron from heteroatom. In terms of adsorption, pyridine VOC adsorption strengths to the TM-cluster doped SDG surfaces are Pt{sub 4} (−2.11 eV) > Pd{sub 4} (−2.05 eV) > Ag{sub 4} (−1.53 eV) > Au{sub 4} (−1.87 eV). Our findings indicate that TM-doped SDG is a suitable adsorbent material for VOC removal. In addition, partial density of states analysis suggests that benzene, furan, and pyrrole interactions with TM cluster are based on p-orbitals of carbon atoms, while pyridine and thiophene interactions are facilitated by hybridized sp{sup 2}-orbitals of heteroatoms. This work provides a key insight into the fundamentals of VOCs adsorption on carbon

  9. The intra-annular acylamide chelate-coordinated compound: The keto-tautomer of metal (II) milrinone complex

    Science.gov (United States)

    Gong, Yun; Liu, Jinzhi; Tang, Wang; Hu, Changwen

    2008-03-01

    In the presence of N, N'-dimethyllformamide (DMF), two isostructural metal (II)-milrinone complexes formulated as M(C 12H 8N 3O) 2 (M = Co 1 and Ni 2) have been synthesized and characterized by elemental analysis, IR, TG and single crystal X-ray diffraction. The two compounds crystallize in the tetragonal system, chiral space group P4 32 12. They exhibit similar two dimensional (2D) square grid-like framework, in which milrinone acts as a ditopic ligand with its terminal pyridine and intra-annular acylamide groups covalently bridging different metal centers. The intra-annular acylamide ligand shows a chelate-coordinated mode. Compounds 1 and 2 are stable under 200 °C. Compound 3 formulated as (C 12H 9N 3O) 4·H 2O was obtained in the presence of water, the water molecule in the structure leads to the racemization of compound 3 and it crystallizes in the monoclinic system, non-chiral space group P2 1/ c. Milrinone exhibits a keto-form in the three compounds and compounds 1- 3 exhibit different photoluminescence properties.

  10. Ionothermal synthesis and structural transformation targeted by ion exchange in metal-1,3,5-benzenetricarboxylate compounds

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qing-Qing [Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi’an 710062, Shaanxi (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Liu, Bing [College of Chemistry and Chemical Engineering, Shaanxi University of Sciences and Technology, Xi’an 710021, Shaanxi (China); Xu, Ling, E-mail: xuling@snnu.edu.cn [Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi’an 710062, Shaanxi (China); Jiao, Huan, E-mail: jiaohuan@snnu.edu.cn [Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi’an 710062, Shaanxi (China)

    2017-03-15

    Ionothermal reactions of 1,3,5-benzenetricarboxylate acid (H{sub 3}BTC) and Ni(NO{sub 3}){sub 2}, Co(NO{sub 3}){sub 2} and Cu(NO{sub 3}){sub 2} gave two discrete 32-membered ring-like allomers, [M{sub 2}(HBTC){sub 2}(NH{sub 2}CONH{sub 2}){sub 2}(H{sub 2}O){sub 4}]·3H{sub 2}O (M=Ni(1), Co(2)) and one layered [Cu{sub 2}(BTC)Cl(H{sub 2}O){sub 4}] (3). The weak interactions in 1 can be deconstructed to some degree in ion exchange by exploring the factors of divalent and trivalent metal species, metal concentration and soaking time, which are demonstrated by PXRD and N{sub 2} absorption. Cu{sup 2+} has the highest N{sub 2} adsorbance when soaking with 1, and 1 can keep structure stable when Cu{sup 2+} below 0.16 mol L{sup −1} and the soaking time within 24d. As Cu{sup 2+} beyond 0.16 mol L{sup −1} and the soaking time beyond 24d, the structure of compound 1 starts to transform with the crystal morphology from clear pale green to opaque blue. Ionothermal reactions of compound 1 with different Cu{sup 2+} amounts obtained Ni{sup 2+}-Cu{sup 2+} hetero complexes, whose PXRD patterns are similar to that of 3 and EDS indicates Cu{sup 2+}% increases with Cu{sup 2+} additions and close to 100% as Cu{sup 2+} being 1.6 mmol. It suggests that 3 is a controlled product and Cu{sup 2+} can transform discrete compound 1 into 2D compound 3. - Graphical abstract: Three compounds were synthesized through ionothermal reactions. The weak interactions in compound 1 can be deconstructed by ion exchange and discrete compound 1 can be transformed into layered compound 3. - Highlights: • Two discrete ring-like and one layered compounds were ionothermally synthesized. • Metal species, metal concentration and soaking time deconstruct the H-bondings in 1. • 1 can be transformed to 3 through ionothermal reaction, otherwise forbidden.

  11. Oriented Decoration in Metal-Functionalized Ordered Mesoporous Silicas and Their Catalytic Applications in the Oxidation of Aromatic Compounds

    Directory of Open Access Journals (Sweden)

    Shijian Zhou

    2018-02-01

    Full Text Available Ordered mesoporous silicas (OMSs attract considerable attention due to their advanced structural properties. However, for the pristine silica materials, the inert property greatly inhibits their catalytic applications. Thus, to contribute to the versatile surface of OMSs, different metal active sites, including acidic/basic sites and redox sites, have been introduced into specific locations (mesoporous channels and framework of OMSs and the metal-functionalized ordered mesoporous silicas (MOMSs show great potential in the catalytic applications. In this review, we first present the categories of metal active sites. Then, the synthesized processes of MOMSs are thoroughly discussed, in which the metal active sites would be introduced with the assistance of organic groups into the specific locations of OMSs. In addition, the structural morphologies of OMSs are elaborated and the catalytic applications of MOMSs in the oxidation of aromatic compounds are illustrated in detail. Finally, the prospects for the future development in this field are proposed.

  12. Flexible strategy for immobilizing redox-active compounds using in situ generation of diazonium salts. Investigations of the blocking and catalytic properties of the layers.

    Science.gov (United States)

    Noël, Jean-Marc; Sjöberg, Béatrice; Marsac, Rémi; Zigah, Dodzi; Bergamini, Jean-François; Wang, Aifang; Rigaut, Stéphane; Hapiot, Philippe; Lagrost, Corinne

    2009-11-03

    A versatile two-step method is developed to covalently immobilize redox-active molecules onto carbon surfaces. First, a robust anchoring platform is grafted onto surfaces by electrochemical reduction of aryl diazonium salts in situ generated. Depending on the nature of the layer termini, -COOH or -NH(2), a further chemical coupling involving ferrocenemethylamine or ferrocene carboxylic acid derivatives leads to the covalent binding of ferrocene centers. The chemical strategy using acyl chloride activation is efficient and flexible, since it can be applied either to surface-reactive end groups or to reactive species in solution. Cyclic voltammetry analyses point to the covalent binding of ferrocene units restricted to the upper layers of the underlying aryl films, while AFM measurements show a lost of compactness of the layers after the chemical attachment of ferrocene centers. The preparation conditions of the anchoring layers were found to determine the interfacial properties of the resulted ferrocenyl-modified electrodes. The ferrocene units promoted effective redox mediation providing that the free redox probes are adequately chosen (i.e., vs size/formal potential) and the underlying layers exhibit strong blocking properties. For anchoring films with weaker blocking effect, the coexistence of two distinct phenomena, redox mediation and ET at pinholes could be evidenced.

  13. Immobilization of Cr(Vi) as a contaminant from soil by iron compounds; Inmovilizacion de Cr(VI) como contaminante del suelo por compuestos de hierro

    Energy Technology Data Exchange (ETDEWEB)

    Marin A, M. de J.; Romero G, E. T. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico); Reyes G, L. R. [Universidad Autonoma del Estado de Hidalgo, Centro de Investigacion en Ciencias de la Tierra, Carretera Pachuca-Tulancingo Km. 4.5, Pachuca 42184, Hidalgo (Mexico)], e-mail: elizabeth.romero@inin.gob.mx

    2008-07-01

    The objective of this research was to determine the physicochemical and surface properties of Fe{sup 0} and FeS to select the appropriate radioactive material for use in the design of artificial barriers or walls and remove Cr (Vi). The physicochemical characterization was carried out of iron: Fe{sup 0} and FeS, using scanning electron microscopy of high vacuum, X-ray diffraction and thermal gravimetric analysis techniques. As for the characterization of the surface, was used to determine the surface area, point of zero charge, density of active sites and kinetics of moisture. We obtained a solution of Cr (Vi) by elution of deionized water on the pollution land of Buenavista, Guanajuato. The concentration of Cr (Vi) from a stock solution was 55.56 mg / L determined by UV-Vis spectrophotometry. Stripping or maximum immobilization of Cr (Vi) with Fe{sup 0} (material chosen by their physicochemical and surface properties) was 68.25% using Fe{sup 0}, at a concentration less than 0.1, ph equal to 3 and a contact time of 24 hours. (Author)

  14. Metal-metal bonded compounds. V. Compounds with Ir (Rh)-Hg bonds containing a bridging and a chelating triazenido group which interconvert intramolecularly

    NARCIS (Netherlands)

    Koten, G. van; Vliet, P.I. van; Kokkes, M.; Vrieze, K.

    1980-01-01

    The compounds [(Diene)(RN{3}R'){2}MHgCl]{2} (M = Ir; Diene = COD; R = CH{3}, C{2}H{5}; R' = p-CH{3}C{6}H{4} and M = Rh; Diene = COD, NOR; R = CH{3}, C{2}H{5}, p-CH{3}-C{6}H{4}; R' = p-CH{3}C{6}H{4} have been prepared by reaction of [(Diene)MCl]{2} with [Hg(RN{3}R'){2}] and by reaction of

  15. Electrocatalysis of the oxidations of some organic compounds on noble-metal electrodes by foreign-metal ad-atoms

    International Nuclear Information System (INIS)

    Tsang, R.W.

    1981-10-01

    Electrochemical oxidation of formic acid was studied on Pt electrodes in acid, and that of dextrose was studied on Pt and Au in alkali. Poisoning was observed on Pt but not on Au. Several heavy-metal ad-atoms (Pb, Bi, Tl) enhance greatly the anodic currents on Pt, while transition metals (Cu, Zn) inhibit the oxidation on Pt. The enhancement effect of the metal ad-atoms is correlated with electron structure. All metal ad-atoms showed an inhibitory effect on Au. Amperometry showed that Pt electrodes are completely deactivated within 10 s during dextrose oxidation without ad-atoms, while Au retains much of its activity even after 10 min. Ad-atoms maintains the Pt activity over much more than 10 s. 50 figures, 38 tables

  16. Heteroepitaxial growth of 3-5 semiconductor compounds by metal-organic chemical vapor deposition for device applications

    Science.gov (United States)

    Collis, Ward J.; Abul-Fadl, Ali

    1988-01-01

    The purpose of this research is to design, install and operate a metal-organic chemical vapor deposition system which is to be used for the epitaxial growth of 3-5 semiconductor binary compounds, and ternary and quaternary alloys. The long-term goal is to utilize this vapor phase deposition in conjunction with existing current controlled liquid phase epitaxy facilities to perform hybrid growth sequences for fabricating integrated optoelectronic devices.

  17. Immobilization and packaging of recovered tritium

    International Nuclear Information System (INIS)

    Holtslander, W.J.; Miller, J.M.

    1982-09-01

    The evaluation of metal hydrides as a medium for immobilization of tritium is reviewed. The work demonstrated methods of preparation and examined the properties of titanium and zirconium hydride for this application. Methods of packaging the metal hydrides for transportation and recoverable storage of tritium were also examined

  18. The immobilization of heavy metals in soil by bioaugmentation of a UV-mutant Bacillus subtilis 38 assisted by NovoGro biostimulation and changes of soil microbial community.

    Science.gov (United States)

    Wang, Ting; Sun, Hongwen; Mao, Hongjun; Zhang, Yanfeng; Wang, Cuiping; Zhang, Zhiyuan; Wang, Baolin; Sun, Lei

    2014-08-15

    Bacillus subtilis 38 (B38) is a mutant species of Bacillus subtilis acquired by UV irradiation with high cadmium tolerance. This study revealed that B38 was a good biosorbent for the adsorption of multiple heavy metals (cadmium, chromium, mercury, and lead). Simultaneous application of B38 and NovoGro (SNB) exhibited a synergetic effect on the immobilization of heavy metals in soil. The heavy metal concentrations in the edible part of the tested plants (lettuce, radish, and soybean) under SNB treatment decreased by 55.4-97.9% compared to the control. Three single extraction methods, diethylenetriaminepentaacetic acid (DTPA), Mehlich 3 (M3), and the first step of the Community Bureau of Reference method (BCR1), showed good predictive capacities for metal bioavailability to leafy, rhizome, and leguminous plant, respectively. The polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) profiles revealed that NovoGro could enhance the proliferation of both exotic B38 and native microbes. Finally, the technology was checked in the field, the reduction in heavy metal concentrations in the edible part of radish was in the range between 30.8% and 96.0% after bioremediation by SNB treatment. This study provides a practical strategy for the remediation of farmland contaminated by multiple heavy metals. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Genetic toxicology of metal compounds. I. Induction of lambda prophage in E coli WP2/sub s/(lambda)

    Energy Technology Data Exchange (ETDEWEB)

    Rossman, T.G.; Molina, M.; Meyer, L.W.

    1984-01-01

    A number of metal compounds have been shown to be human carcinogens. Others, while not proven human carcinogens, are able to cause tumors in laboratory animals. Short-term bacterial assays for genotoxic effects have not been successful in predicting the carcinogenicity of metal compounds. The authors report here the ability of some metal compounds to cause the induction of lambda prophage in E coli WP2/sub s/(lambda). By far the strongest inducing ability was observed with K/sub 2/CrO/sub 4/, followed by Pb(NO/sub 3/)/sub 2/ > Ni(OOCCH/sub 3/)/sub 2/ > CrCl/sub 2/ > NaWO/sub 4/ > Na/sub 2/MoO/sub 4/ > KMnO/sub 4/. With the exception of chromate, long-term exposures in a narrow, subtoxic dose range were required in order to demonstrate phage induction. A new microtiter assay for lambda prophage induction, which incorporates these features, is described. This system also was able to detect very small amounts of organic carcinogens.

  20. New pathway for the formation of metallic cubic phase Ge-Sb-Te compounds induced by an electric current.

    Science.gov (United States)

    Park, Yong-Jin; Cho, Ju-Young; Jeong, Min-Woo; Na, Sekwon; Joo, Young-Chang

    2016-02-23

    The novel discovery of a current-induced transition from insulator to metal in the crystalline phase of Ge2Sb2Te5 and GeSb4Te7 have been studied by means of a model using line-patterned samples. The resistivity of cubic phase Ge-Sb-Te compound was reduced by an electrical current (~1 MA/cm(2)), and the final resistivity was determined based on the stress current density, regardless of the initial resistivity and temperature, which indicates that the conductivity of Ge-Sb-Te compound can be modulated by an electrical current. The minimum resistivity of Ge-Sb-Te materials can be achieved at high kinetic rates by applying an electrical current, and the material properties change from insulating to metallic behavior without a phase transition. The current-induced metal transition is more effective in GeSb4Te7 than Ge2Sb2Te5, which depends on the intrinsic vacancy of materials. Electromigration, which is the migration of atoms induced by a momentum transfer from charge carriers, can easily promote the rearrangement of vacancies in the cubic phase of Ge-Sb-Te compound. This behavior differs significantly from thermal annealing, which accompanies a phase transition to the hexagonal phase. This result suggests a new pathway for modulating the electrical conductivity and material properties of chalcogenide materials by applying an electrical current.

  1. Universal biomimetic preparation and immobilization of layered double hydroxide films and adsorption behavior

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Wei; Zhang, Wenpeng; Chen, Zilin

    2017-01-15

    Highlights: • An in situ method is developed for immobilization of nanoscale LDHs. • The universal method can be applied on multiple substrates. • The homogeneous LDHs film can be synthesis and immobilized in one step. • The LDHs film showed good adsorption performance towards anionic compounds. - Abstract: Preparation and immobilization of layered double hydroxides (LDHs) film onto multiple substrates is important and challenging in functional materials fields by date. In this work, a simple and universal polydopamine (PD)-based layer-by-layer assembly strategy was developed for the immobilization of LDHs film onto surfaces such as polypropylene chip, glass slides and metal coins. The surface of substrates was firstly modified by polydopamine functionalization, and then LDHs film was synthesized via urea method and directly immobilized on the PD layer by in situ growing strategy in one step. The PD layer as well as the final LDHs film was characterized by energy dispersive X-ray spectroscopy, scanning electron microscope, infrared spectroscopy, X-ray diffraction pattern and X-ray photoelectron spectra. It has been demonstrated the formation of the dense and homogeneous nanoscaled LDHs film with 400 nm thickness. Adsorption behavior of the fabricated NiAl-LDHs film toward anionic dyes and pharmaceuticals was further assessed. To demonstrate their extensive application, fast and high efficient adsorption of anionic dyes and pharmaceuticals was achieved by NiAl-LDHs-modified polypropylene centrifugal tube.

  2. Study of immobilization of waste from treatment of acid waters of a uranium mining facility

    International Nuclear Information System (INIS)

    Goda, R.T.; Oliveira, A.P. de; Silva, N.C. da; Villegas, R.A.S.; Ferreira, A.M.

    2017-01-01

    This study aimed to produce scientific and technical knowledge aiming at the development of techniques to immobilize the waste generated in the treatment of acid waters in the UTM-INB Caldas uranium mining and processing facility using Portland cement. This residue (calcium diuranate - DUCA) contains uranium compounds and metal hydroxides in a matrix of calcium sulfate. It is observed that this material, in contact with the lake of acid waters of the mine's own pit, undergoes resolubilization and, therefore, changes the quality of the acidic water contained therein, changing the treatment parameters. For the study of immobilization of this residue, the mass of water contained in both the residue deposited in the pit of the mine and in the pulp resulting from the treatment of the acid waters was determined. In addition, different DUCA / CEMENT / WATER ratios were used for immobilization and subsequent mechanical strength and leaching tests. The results showed that in the immobilized samples with 50% cement mass condition, no uranium was detected in the leaching tests, and the mechanical strength at compression was 9.4 MPa, which indicates that more studies are needed, but indicate a good capacity to immobilize uranium in cement

  3. Magnetism in ordered metallic perovskite compound GdPd{sub 3}B{sub x}C{sub 1-x}

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Abhishek [S.N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700098 (India); Experimental Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)], E-mail: abhishek.phy@gmail.com; Mazumdar, Chandan [Experimental Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)], E-mail: chandan.mazumdar@saha.ac.in; Ranganathan, R. [Experimental Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India); Dattagupta, S. [Indian Institute of Science Education and Research, Block-HC, Sector-III, Salt Lake, Kolkata 700106 (India)

    2009-08-15

    We report results of dc-magnetization, ac-susceptibility and magnetoresistance measurements on crystalline metallic-perovskite compounds GdPd{sub 3}B{sub x}C{sub 1-x} (x=0.25, 0.50, 0.75 and 1.00) and the parent cubic compound GdPd{sub 3}. The interest in these materials stems from the observation of negative temperature coefficient of resistance and negative thermal expansion in some of the members of this series. In the present study, we show that by substitution of non-magnetic elements, boron and carbon, the nature of the magnetic interaction can be varied from dominating ferromagnetic to antiferromagnetic and finally to a canted magnetic structure without altering the crystal symmetry of the compounds. The variation of magnetic interaction by modifying the lattice parameter resembles Ruderman-Kittel-Kasuya-Yosida (RKKY) oscillations.

  4. Plasmachemical synthesis and evaluation of the thermal conductivity of metal-oxide compounds "Molybdenum-uranium dioxide"

    Science.gov (United States)

    Kotelnikova, Alexandra A.; Karengin, Alexander G.; Mendoza, Orlando

    2018-03-01

    The article represents possibility to apply oxidative and reducing plasma for plasma-chemical synthesis of metal-oxide compounds «Mo‒UO2» from water-salt mixtures «molybdic acid‒uranyl nitrate» and «molybdic acid‒ uranyl acetate». The composition of water-salt mixture was calculated and the conditions ensuring plasma-chemical synthesis of «Mo‒UO2» compounds were determined. Calculations were carried out at atmospheric pressure over a wide range of temperatures (300-4000 K), with the use of various plasma coolants (air, hydrogen). The heat conductivity coefficients of metal-oxide compounds «Mo‒UO2» consisting of continuous component (molybdenum matrix) are calculated. Inclusions from ceramics in the form of uranium dioxide were ordered in the matrix. Particular attention is paid to methods for calculating the coefficients of thermal conductivity of these compounds with the use of different models. Calculated results were compared with the experimental data.

  5. Gas-phase fragmentation of coordination compounds: loss of CO(2) from inorganic carbonato complexes to give metal oxide ions

    Science.gov (United States)

    Dalgaard; McKenzie

    1999-10-01

    Using electrospray ionization mass spectrometry, novel transition metal oxide coordination complex ions are proposed as the products of the collision-induced dissociation (CID) of some carbonato complex ions through the loss of a mass equivalent to CO(2). CID spectra of [(tpa)CoCO(3)](+) (tpa = tris(2-pyridylmethyl)methylamine), [(bispicMe(2)en)Fe(&mgr;-O)(&mgr;-CO(3))Fe(bispicMe(2)en)]2+ (bispicMe(2)en = N,N'-dimethyl-N,N'-bis(2-pyridylmethy)eth- ane-1, 2-diamine) and [(bpbp)Cu(2)CO(3)](+) (bpbp(-) = bis[(bis-(2-pyridylmethyl)amino)methyl]-4-tertbutylpheno-lato(1-)), show peaks assigned to the mono- and dinuclear oxide cations, [(tpa)CoO](+), [(bispicMe(2)en)(2)Fe(2)(O)(2)]2+ and [(bpbp)Cu(2)O](+), as the dominant species. These results can be likened to the reverse of typical synthetic reactions in which metal hydroxide compounds react with CO(2) to give metal carbonato compounds. Because of the lack of available protons in the gas phase, novel oxide species rather than the more common hydroxide ions are generated. These oxide ions are relevant to the highly oxidizing species proposed in oxygenation reactions catalysed by metal oxides and metalloenzymes. Copyright 1999 John Wiley & Sons, Ltd.

  6. Investigation of spin-gapless semiconductivity and half-metallicity in Ti2MnAl-based compounds

    International Nuclear Information System (INIS)

    Lukashev, P.; Staten, B.; Hurley, N.; Kharel, P.; Gilbert, S.; Fuglsby, R.; Huh, Y.; Valloppilly, S.; Zhang, W.; Skomski, R.; Sellmyer, D. J.; Yang, K.

    2016-01-01

    The increasing interest in spin-based electronics has led to a vigorous search for new materials that can provide a high degree of spin polarization in electron transport. An ideal candidate would act as an insulator for one spin channel and a conductor or semiconductor for the opposite spin channel, corresponding to the respective cases of half-metallicity and spin-gapless semiconductivity. Our first-principle electronic-structure calculations indicate that the metallic Heusler compound Ti 2 MnAl becomes half-metallic and spin-gapless semiconducting if half of the Al atoms are replaced by Sn and In, respectively. These electronic structures are associated with structural transitions from the regular cubic Heusler structure to the inverted cubic Heusler structure.

  7. Tentacle carrier for immobilization of potato phenoloxidase and its application for halogenophenols removal from aqueous solutions

    International Nuclear Information System (INIS)

    Lončar, Nikola; Vujčić, Zoran

    2011-01-01

    Highlights: ► We synthesized novel immobilization carrier from reused DEAE-cellulose. ► We used it for immobilization of PPO through coordinative bonding with copper ions. ► Immobilized PPO showed better characteristics than soluble PPO. ► TC-PPO removed over 90% of halogenophenols at concentration of 100 mg/L. - Abstract: Halogenated compounds represent one of the most dangerous environmental pollutants, due to their widespread usage as biocides, fungicides, disinfectants, solvent and other industrial chemicals. Immobilization of a protein through coordinate bonds formed with divalent metal ions is becoming an attractive method due to its reversible nature, since the protein may be easily removed from the support matrix through interruption of the protein–metal bond hence giving inherently cleaner and cheaper technology for wastewater treatment. We have synthesized novel ‘tentacle’ carrier (TC) and used it for immobilization of partially purified potato polyphenol oxidase (PPO). The obtained biocatalyst TC-PPO showed pH optimum at 7.0–8.0 and temperature optimum at 25 °C. Immobilized PPO shows almost 100% of activity at 0 °C. TC-PPO was more resistant to the denaturation induced by sodium dodecyl sulphate (SDS) detergent as compared to its soluble counterpart and was even slightly activated at SDS concentration of 1%. TC-PPO was tested in the batch reactor for 4-chlorophenol and 4-bromophenol removal. More than 90% removal was achieved for both halogenophenols at concentration of 100 mg/L from aqueous solution. For both halogenophenols TC-PPO works with over 90% removal during first three cycles which decrease to 60% removal efficiency after six cycles each of 8 h duration.

  8. Tentacle carrier for immobilization of potato phenoloxidase and its application for halogenophenols removal from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Loncar, Nikola, E-mail: nloncar@chem.bg.ac.rs [Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade (Serbia); Vujcic, Zoran, E-mail: zvujcic@chem.bg.ac.rs [Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade (Serbia)

    2011-11-30

    Highlights: Black-Right-Pointing-Pointer We synthesized novel immobilization carrier from reused DEAE-cellulose. Black-Right-Pointing-Pointer We used it for immobilization of PPO through coordinative bonding with copper ions. Black-Right-Pointing-Pointer Immobilized PPO showed better characteristics than soluble PPO. Black-Right-Pointing-Pointer TC-PPO removed over 90% of halogenophenols at concentration of 100 mg/L. - Abstract: Halogenated compounds represent one of the most dangerous environmental pollutants, due to their widespread usage as biocides, fungicides, disinfectants, solvent and other industrial chemicals. Immobilization of a protein through coordinate bonds formed with divalent metal ions is becoming an attractive method due to its reversible nature, since the protein may be easily removed from the support matrix through interruption of the protein-metal bond hence giving inherently cleaner and cheaper technology for wastewater treatment. We have synthesized novel 'tentacle' carrier (TC) and used it for immobilization of partially purified potato polyphenol oxidase (PPO). The obtained biocatalyst TC-PPO showed pH optimum at 7.0-8.0 and temperature optimum at 25 Degree-Sign C. Immobilized PPO shows almost 100% of activity at 0 Degree-Sign C. TC-PPO was more resistant to the denaturation induced by sodium dodecyl sulphate (SDS) detergent as compared to its soluble counterpart and was even slightly activated at SDS concentration of 1%. TC-PPO was tested in the batch reactor for 4-chlorophenol and 4-bromophenol removal. More than 90% removal was achieved for both halogenophenols at concentration of 100 mg/L from aqueous solution. For both halogenophenols TC-PPO works with over 90% removal during first three cycles which decrease to 60% removal efficiency after six cycles each of 8 h duration.

  9. Vacuum tight sodium resistant compound between ThO2 ceramic and metal

    International Nuclear Information System (INIS)

    Reetz, T.

    A method for evaluating the mechanical tensions for metal/ ceramic joinings was applied to the selection of metal components for a highly vacuum tight, sodium-resistant metal/ThO 2 ceramic solder joining. The metal component selected was the iron--nickel alloy Dilasil which is joined to the ceramic using a nickel-based solder. The wetting of the cearamic could be carried out using the titanium hydride technique or after the formation of a W-cerium layer on the surface of this ceramic. (U.S.)

  10. First-principles study of new quaternary Heusler compounds without 3d transition metal elements: ZrRhHfZ (Z = Al, Ga, In)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaotian [School of Material Sciences and Engineering, Hebei University of Technology, Tianjin 300130 (China); Institute for Superconducting & Electronic Materials (ISEM), University of Wollongong, Wollongong 2500 (Australia); Cheng, Zhenxiang, E-mail: cheng@uow.edu.au [Institute for Superconducting & Electronic Materials (ISEM), University of Wollongong, Wollongong 2500 (Australia); Guo, Ruikang [School of Material Sciences and Engineering, Hebei University of Technology, Tianjin 300130 (China); Wang, Jianli [Institute for Superconducting & Electronic Materials (ISEM), University of Wollongong, Wollongong 2500 (Australia); Rozale, Habib [Condensed Matter and Sustainable Development Laboratory, Physics Department, University of Sidi-Bel-Abbès, 22000 Sidi-Bel-Abbès (Algeria); Wang, Liying [Department of Physics, Tianjin University, Tianjin 300350 (China); Yu, Zheyin [Institute for Superconducting & Electronic Materials (ISEM), University of Wollongong, Wollongong 2500 (Australia); Liu, Guodong, E-mail: gdliu1978@126.com [School of Material Sciences and Engineering, Hebei University of Technology, Tianjin 300130 (China)

    2017-06-01

    Plane-wave pseudo-potential methods based on density functional theory are employed to investigate the electronic structures, and the magnetic and half-metallic properties of the newly designed quaternary Heusler compounds ZrRhHfZ (Z = Al, Ga, In) without 3d transition metal elements. The calculated results show that ZrRhHfZ (Z = Al, Ga, In) compounds are half-metallic, with 100% spin polarization around the Fermi level. The structural stability of these compounds has been tested from the aspects of their cohesion energy and formation. The spin-flip/half-metallic gaps of ZrRhHfZ (Z = Al, Ga, In) compounds are quite large, with values of 0.2548 eV, 0.3483 eV, and 0.2866 eV, respectively. These compounds show Slater-Pauling behavior, and the total spin magnetic moment per unit cell (M{sub t}) scales with the total number of valence electrons (Z{sub t}) following the rule: M{sub t} = Z{sub t} - 18. The magnetization of ZrRhHfZ (Z = Al, Ga, In) compounds mainly comes from the 4d electrons of the Zr atoms and the 5d electrons of the Hf atoms. Furthermore, the effects of uniform strain and tetragonal deformation on the half metallicity has been investigated in detail, which is important for practical application. Finally, we reveal that the half-metallicity can be maintained when the Coulomb interactions are considered. - Highlights: • New quaternary compounds without 3d transition metal elements have been designed. • The electronic structures and magnetism of the ZrRhHfZ compounds have been studied. • The effect of strain on the half-metallic behavior has been tested. • The effect of the Coulomb interactions on the half-metallicity has been investigated.

  11. Coordination compounds of rare-earth metals with organic ligands for electroluminescent diodes

    International Nuclear Information System (INIS)

    Katkova, M A; Bochkarev, Mikhail N; Vitukhnovsky, Alexey G

    2005-01-01

    Data on lanthanide coordination compounds with organic ligands used in the design of electroluminescent diodes are summarised and systematically represented. The molecular and electronic structures and spectroscopic characteristics of these compounds are considered. A comparative analysis of the properties of organic electroluminescent diodes with different compositions of emitting and conductive layers is presented.

  12. Gold nanoparticles modified with coordination compounds of metals: synthesis and application

    International Nuclear Information System (INIS)

    Beloglazkina, Elena K; Majouga, Alexander G; Romashkina, Renata B; Zyk, Nikolai V; Zefirov, Nikolai S

    2012-01-01

    The data on the preparation methods and applications of gold nanoparticles with coordinated metal ions on the surfaces are generalized. The currently available data on the interaction of metal ions with gold nanoparticles modified with organic (particularly, sulfur-containing) ligands comprising terminal chelating groups are considered in detail as well as the applications of such modified nanoparticles. The bibliography includes 141 references.

  13. Effects of metal compounds with distinct physicochemical properties on iron homeostasis and antibacterial activity in the lungs: chromium and vanadium.

    Science.gov (United States)

    Cohen, Mitchell D; Sisco, Maureen; Prophete, Colette; Yoshida, Kotaro; Chen, Lung-chi; Zelikoff, Judith T; Smee, Jason; Holder, Alvin A; Stonehuerner, Jacqueline; Crans, Debbie C; Ghio, Andrew J

    2010-02-01

    In situ reactions of metal ions or their compounds are important mechanisms by which particles alter lung immune responses. The authors hypothesized that major determinants of the immunomodulatory effect of any metal include its redox behavior/properties, oxidation state, and/or solubility, and that the toxicities arising from differences in physicochemical parameters are manifest, in part, via differential shifts in lung iron (Fe) homeostasis. To test the hypotheses, immunomodulatory potentials for both pentavalent vanadium (VV; as soluble metavanadate or insoluble vanadium pentoxide) and hexavalent chromium (CrVI; as soluble sodium chromate or insoluble calcium chromate) were quantified in rats after inhalation (5h/day for 5 days) of each at 100 microg metal/m3. Differences in effects on local bacterial resistance between the two VV, and between each CrVI, agents suggested that solubility might be a determinant of in situ immunotoxicity. For the soluble forms, VV had a greater impact on resistance than CrVI, indicating that redox behavior/properties was likely also a determinant. The soluble VV agent was the strongest immunomodulant. Regarding Fe homeostasis, both VV agents had dramatic effects on airway Fe levels. Both also impacted local immune/airway epithelial cell Fe levels in that there were significant increases in production of select cytokines/chemokines whose genes are subject to regulation by HIF-1 (whose intracellular longevity is related to cell Fe status). Our findings contribute to a better understanding of the role that metal compound properties play in respiratory disease pathogenesis and provide a rationale for differing pulmonary immunotoxicities of commonly encountered ambient metal pollutants.

  14. Diazo compounds and N-tosylhydrazones: novel cross-coupling partners in transition-metal-catalyzed reactions.

    Science.gov (United States)

    Xiao, Qing; Zhang, Yan; Wang, Jianbo

    2013-02-19

    Transition-metal-catalyzed carbene transformations and cross-couplings represent two major reaction types in organometallic chemistry and organic synthesis. However, for a long period of time, these two important areas have evolved separately, with essentially no overlap or integration. Thus, an intriguing question has emerged: can cross-coupling and metal carbene transformations be merged into a single reaction cycle? Such a combination could facilitate the development of novel carbon-carbon bond-forming methodologies. Although this concept was first explored about 10 years ago, rapid developments inthis area have been achieved recently. Palladium catalysts can be used to couple diazo compounds with a wide variety of organic halides. Under oxidative coupling conditions, diazo compounds can also react with arylboronic acids and terminal alkynes. Both of these coupling reactions form carbon-carbon double bonds. As the key step in these catalytic processes, Pd carbene migratory insertion plays a vital role in merging the elementary steps of Pd intermediates, leading to novel carbon-carbon bond formations. Because the diazo substrates can be generated in situ from N-tosylhydrazones in the presence of base, the N-tosylhydrazones can be used as reaction partners, making this type of cross-coupling reaction practical in organic synthesis. N-Tosylhydrazones are easily derived from the corresponding aldehydes or ketones. The Pd-catalyzed cross-coupling of N-tosylhydrazones is considered a complementary reaction to the classic Shapiro reaction for converting carbonyl functionalities into carbon-carbon double bonds. It can also serve as an alternative approach for the Pd-catalyzed cross-coupling of carbonyl compounds, which is usually achieved via triflates. The combination of carbene formation and cross-coupling in a single catalytic cycle is not limited to Pd-catalyzed reactions. Recent studies of Cu-, Rh-, Ni-, and Co-catalyzed cross-coupling reactions with diazo

  15. Effects of complexing compounds on sorption of metal ions to cement

    Energy Technology Data Exchange (ETDEWEB)

    Loevgren, Lars [Umeaa Univ. (Sweden). Inorganic chemistry

    2005-12-15

    This present report is a literature review addressing the effects of complexing ligands on the sorption of radionuclides to solid materials of importance for repositories of radioactive waste. Focus is put on laboratory studies of metal ion adsorption to cement in presence of chelating agents under strongly alkaline conditions. As background information, metal sorption to different mineral and cement phases in ligand free systems is described. Furthermore, surface complexation model (SCM) theories are introduced. According to surface complexation theories these interactions occur at specific binding sites at the particle/water interface. Adsorption of cationic metals is stronger at high pH, and the adsorption of anions occurs preferentially at low pH. The adsorption of ions to mineral surfaces is a result of both chemical bonding and electrostatic attraction between the ions and charged mineral surfaces. By combining uptake data with spectroscopic information the sorption can be explained on a molecular level by structurally sound surface complexation models. Most of the metal sorption studies reviewed are dealing with minerals exhibiting oxygen atoms at their surfaces, mainly oxides of Fe(II,III) and Al(III), and aluminosilicates. Investigations of radionuclides are focused on clay minerals, above all montmorillonite and illite. Which mechanism that is governing the metal ion adsorption to a given mineral is to a large extent depending on the metal adsorbed. For instance, sorption of Ni to montmorillonite can occur by formation of inner-sphere mononuclear surface complexes located at the edges of montmorillonite platelets and by formation of a Ni phyllosilicate phase parallel to montmorillonite layers. Also metal uptake to cement materials can occur by different mechanisms. Cationic metals can both be attached to cement (calcium silicate hydrate, CSH) and hardened cement paste (HCP) by formation of inner-sphere complexes at specific surface sites and by

  16. Metal based biologically active compounds: Design, synthesis, DNA binding and antidiabetic activity of 6-methyl-3-formyl chromone derived hydrazones and their metal (II) complexes.

    Science.gov (United States)

    Philip, Jessica Elizabeth; Shahid, Muhammad; Prathapachandra Kurup, M R; Velayudhan, Mohanan Puzhavoorparambil

    2017-10-01

    Two chromone hydrazone ligands HL 1 and HL 2 were synthesized and characterized by elemental analyses, IR, 1 H NMR & 13 C NMR, electronic absorption and mass spectra. The reactions of the chromone hydrazones with transition metals such as Ni, Cu, and Zn (II) salts of acetate afforded mononuclear metal complexes. Characterization and structure elucidation of the prepared chromone hydrazone metal (II) complexes were done by elemental, IR, electronic, EPR spectra and thermo gravimetric analyses as well as conductivity and magnetic susceptibility measurements. The spectroscopic data showed that the ligand acts as a mono basic bidentate with coordination sites are azomethine nitrogen and hydrazonic oxygen, and they exhibited distorted geometry. The biological studies involved antidiabetic activity i.e. enzyme inhibition of α-amylase and α-glucosidase, Calf Thymus - DNA (CT-DNA) interaction and molecular docking. Potential capacity of synthesized compounds to inhibit the α-amylase and α-glucosidase activity was assayed whereas DNA interaction studies were carried out with the help UV-Vis absorption titration and viscosity method. The docking studies of chromone hydrazones show that they are minor groove binders. Complexes were found to be good DNA - intercalates. Chromone hydrazones and its transition metal complexes have shown comparable antidiabetic activity with a standard drug acarbose. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Radionuclides, Trace Metals, and Organic Compounds in Shells of Native Freshwater Mussels Along the Hanford Reach of the Columbia River: 6000 Years Before Present to Current Times

    Energy Technology Data Exchange (ETDEWEB)

    B. L. Tiller; T. E. Marceau

    2006-01-25

    This report documents concentrations of radionuclides, trace metals, and semivolatile organic compounds measured in shell samples of the western pearl shell mussel collected along the Hanford Reach of the Columbia River.

  18. Interaction of Model Inhibitor Compounds with Minimalist Cluster Representations of Hydroxyl Terminated Metal Oxide Surfaces

    Directory of Open Access Journals (Sweden)

    Christopher D. Taylor

    2018-01-01

    Full Text Available The computational modeling of corrosion inhibitors at the level of molecular interactions has been pursued for decades, and recent developments are allowing increasingly realistic models to be developed for inhibitor–inhibitor, inhibitor–solvent and inhibitor–metal interactions. At the same time, there remains a need for simplistic models to be used for the purpose of screening molecules for proposed inhibitor performance. Herein, we apply a reductionist model for metal surfaces consisting of a metal cation with hydroxide ligands and use quantum chemical modeling to approximate the free energy of adsorption for several imidazoline class candidate corrosion inhibitors. The approximation is made using the binding energy and the partition coefficient. As in some previous work, we consider different methods for incorporating solvent and reference systems for the partition coefficient. We compare the findings from this short study with some previous theoretical work on similar systems. The binding energies for the inhibitors to the metal hydroxide clusters are found to be intermediate to the binding energies calculated in other work for bare metal vs. metal oxide surfaces. The method is applied to copper, iron, aluminum and nickel metal systems.

  19. physical properties of some noble metal compounds from paw-dft

    African Journals Online (AJOL)

    PUBLICATIONS1

    The heats of formation, shear modulus, fracture toughness, density and melting points of com- ... of the 17 thermodynamically stable compounds are predicted with better hardness. Better frac- .... The hardness of a material has been correlated.

  20. Hydrodeoxygenation of mono- and dimeric lignin model compounds on noble metal catalysts

    NARCIS (Netherlands)

    Guvenatam, Burcu; Kursun, Osman; Heeres, Hero; Pidko, Evgeny A.; Hensen, Emiel J. M.

    2014-01-01

    The influence of reaction conditions (temperature, acidity) on the catalytic performance of supported Pt, Pd and Ru catalysts for the aqueous phase hydrodeoxygenation (HDO) of lignin model compounds was systematically investigated. Phenol conversion proceeds via hydrogenation of the aromatic ring

  1. The Study and Development of Metal Oxide Reactive Adsorbents for the Destruction of Toxic Organic Compounds

    National Research Council Canada - National Science Library

    Mitchell, Mark B

    2008-01-01

    ... and other toxic organic compounds. The research program that was developed built upon earlier results achieved in the room temperature oxidative decomposition of a chemical warfare agent simulant, dimethyl methylphosphonate (DMMP...

  2. Fundamental Studies of the Reforming of Oxygenated Compounds over Supported Metal Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Dumesic, James A. [Univ. of Wisconsin, Madison, WI (United States)

    2016-01-04

    The main objective of our research has been to elucidate fundamental concepts associated with controlling the activity, selectivity, and stability of bifunctional, metal-based heterogeneous catalysts for tandem reactions, such as liquid-phase conversion of oxygenated hydrocarbons derived from biomass. We have shown that bimetallic catalysts that combine a highly-reducible metal (e.g., platinum) with an oxygen-containing metal promoter (e.g., molybdenum) are promising materials for conversion of oxygenated hydrocarbons because of their high activity for selective cleavage for carbon-oxygen bonds. We have developed methods to stabilize metal nanoparticles against leaching and sintering under liquid-phase reaction conditions by using atomic layer deposition (ALD) to apply oxide overcoat layers. We have used controlled surface reactions to produce bimetallic catalysts with controlled particle size and controlled composition, with an important application being the selective conversion of biomass-derived molecules. The synthesis of catalysts by traditional methods may produce a wide distribution of metal particle sizes and compositions; and thus, results from spectroscopic and reactions kinetics measurements have contributions from a distribution of active sites, making it difficult to assess how the size and composition of the metal particles affect the nature of the surface, the active sites, and the catalytic behavior. Thus, we have developed methods to synthesize bimetallic nanoparticles with controlled particle size and controlled composition to achieve an effective link between characterization and reactivity, and between theory and experiment. We have also used ALD to modify supported metal catalysts by addition of promoters with atomic-level precision, to produce new bifunctional sites for selective catalytic transformations. We have used a variety of techniques to characterize the metal nanoparticles in our catalysts, including scanning transmission electron

  3. Chiral phosphites as ligands in asymmetric metal complex catalysis and synthesis of coordination compounds

    International Nuclear Information System (INIS)

    Gavrilov, Konstantin N; Bondarev, Oleg G; Polosukhin, Aleksei I

    2004-01-01

    The data published during the last five years on the application of chiral derivatives of phosphorous acid in coordination chemistry and enantioselective catalysis are summarised and discussed. The effect of the nature of these ligands on the structure of metal complexes and on the efficiency of catalytic organic syntheses is shown. Hydroformylation, hydrogenation, allylic substitution and conjugate addition catalysed by transition metal complexes with optically active phosphites and hydrophosphoranes are considered. The prospects for the development of this field of research are demonstrated.

  4. Spectroscopic studies of organometallic compounds on single crystal metal surfaces: Surface acetylides of silver (110)

    Science.gov (United States)

    Madix, Robert J.

    The nature of compounds formed by the reaction of organic molecules with metal surfaces can be studied with a battery of analytical methods based on both physicals and chemical understanding. In this paper the application of UPS, XPS, LEED and EELS as well as temperature programmed reaction spectroscopy (TPRS) and chemical titration methods to the characterization of surface complexes is discussed. Particular emphasis is given to the reaction of acetylene with a single crystal surface of silver, Ag(110). Previous work has shown that this surface, when clean, is unreactive to hydrocarbons, alcohols and carboxylic acids under ultra high vacuum conditions. Preadsorption of oxygen, however, renders the surface reactive, and a wide variety of organometallic surface compounds can be formed. As expected then, no stable adsorption state and no reaction was observed with clean Ag(110) following room temperature exposure to acetylene. Following exposure at 150 K, however, a weekly bound chemisorption state was observed to desorb at 195 K, indicating a binding energy to the surface of approximately 12 kcal/gmole. Reaction with preadsorbed oxygen gave water formulation upon dosing and produced surface intermediates which yeilded two acetylene desorption states at 195 and 175 K. Heating above 300 K to completely desorb the higher temperature state produced new, well-defined LEED Features due to residual surface carbon which disappeared when the surface was heated above 550 K. Clearly, there were distinc changes in the nature of the absorbed layer at 195, 300 and 550 K. These changes were reflected in XPS. For the weakly chemisorbed acetylene a large C(ls) peak at 285.6 eV with a small, broad, indistinc shoulder at higher binding energy (288.2) was observed. The spectrum of the species following acetylene desorption at 275 K, however, showed the formulation of a large C(ls) peak at 283.6 eV in addition to peaks characteristics of the weakly chemisorbed state. This result

  5. Noble metal catalyzed aqueous phase hydrogenation and hydrodeoxygenation of lignin-derived pyrolysis oil and related model compounds.

    Science.gov (United States)

    Mu, Wei; Ben, Haoxi; Du, Xiaotang; Zhang, Xiaodan; Hu, Fan; Liu, Wei; Ragauskas, Arthur J; Deng, Yulin

    2014-12-01

    Aqueous phase hydrodeoxygenation of lignin pyrolysis oil and related model compounds were investigated using four noble metals supported on activated carbon. The hydrodeoxygenation of guaiacol has three major reaction pathways and the demethylation reaction, mainly catalyzed by Pd, Pt and Rh, produces catechol as the products. The presence of catechol and guaiacol in the reaction is responsible for the coke formation and the catalysts deactivation. As expected, there was a significant decrease in the specific surface area of Pd, Pt and Rh catalysts during the catalytic reaction because of the coke deposition. In contrast, no catechol was produced from guaiacol when Ru was used so a completely hydrogenation was accomplished. The lignin pyrolysis oil upgrading with Pt and Ru catalysts further validated the reaction mechanism deduced from model compounds. Fully hydrogenated bio-oil was produced with Ru catalyst. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. The adsorption and reaction of halogenated volatile organic compounds (VOC's) on metal oxides. 1998 annual progress report

    International Nuclear Information System (INIS)

    Goodman, D.W.; Haw, J.F.; Lunsford, J.

    1998-01-01

    'The goal of the research is to elucidate the properties of the materials responsible for the activation of halocarbons and the nature of the intermediates formed in the dissociative adsorption of this class of compounds. This information is essential for interpreting and predicting stoichiometric and catalytic pathways for the safe destruction of halocarbon pollutants. The specific objectives are: (1) to study the adsorption and reactivity of chloromethanes and chloroethanes on metal oxides; (2) to identify the reaction intermediates using spectroscopic methods; and (3) to develop kinetic models for the reaction of these halocarbons with oxide surfaces. This report summarizes work after 20 months of a 36-month project. Emphasis has been placed understanding the surfaces phases, as well as the bulk phases that are present during the reactions of chlorinated hydrocarbons with strongly basic metal oxides. Most of the research has been carried out with carbon tetrachloride.'

  7. Study of X-ray L2 absorption edges of Gd, Dy, Ho and Er in metals and compounds

    International Nuclear Information System (INIS)

    Agarwal, B.K.; Agarwal, B.R.K.

    1978-01-01

    The positions and shapes of L2 X-ray absorption edges of Gd, Dy, Ho and Er have been studied in metals and in oxides and chlorides, using a forty centimetre bent mica crystal spectrograph. It has been found that the L2 edge shifts towards the high energy side in the compounds and that the chemical shift ΔE depends on the degree of covalency involved. The white line structure at the edge has been analysed in terms of transitions of L2 shell electron to optical nd (n >= 5) states. (author)

  8. Metal derivatives of organo-phosphorous compounds. Part II : niobium(V) and tantalum(V) derivatives

    International Nuclear Information System (INIS)

    Puri, D.M.; Singh, Soran

    1981-01-01

    Reactions between niobium(V) chloride, tantalum(V) chloride and dialkyl/diaryl (Et-, Prsup(i)-, Busup(n)- and Ph-) phosphites have been studied in different molar ratios and under different conditions of temperature and solvent systems. The isolated complex compounds have been characterised on the basis of infrared spectral measurements, elemental analyses and magnetic susceptibility data. The polymeric nature of the products has been indicated by their molecular weights. The coordination of phosphite units to metal atom of the other molecule through phosphoryl oxygen gave rise to O-P-O-bridges. (author)

  9. Particulate metals and organic compounds from electronic and tobacco-containing cigarettes: comparison of emission rates and secondhand exposure.

    Science.gov (United States)

    Saffari, Arian; Daher, Nancy; Ruprecht, Ario; De Marco, Cinzia; Pozzi, Paolo; Boffi, Roberto; Hamad, Samera H; Shafer, Martin M; Schauer, James J; Westerdahl, Dane; Sioutas, Constantinos

    2014-01-01

    In recent years, electronic cigarettes have gained increasing popularity as alternatives to normal (tobacco-containing) cigarettes. In the present study, particles generated by e-cigarettes and normal cigarettes have been analyzed and the degree of exposure to different chemical agents and their emission rates were quantified. Despite the 10-fold decrease in the total exposure to particulate elements in e-cigarettes compared to normal cigarettes, specific metals (e.g. Ni and Ag) still displayed a higher emission rate from e-cigarettes. Further analysis indicated that the contribution of e-liquid to the emission of these metals is rather minimal, implying that they likely originate from other components of the e-cigarette device or other indoor sources. Organic species had lower emission rates during e-cigarette consumption compared to normal cigarettes. Of particular note was the non-detectable emission of polycyclic aromatic hydrocarbons (PAHs) from e-cigarettes, while substantial emission of these species was observed from normal cigarettes. Overall, with the exception of Ni, Zn, and Ag, the consumption of e-cigarettes resulted in a remarkable decrease in secondhand exposure to all metals and organic compounds. Implementing quality control protocols on the manufacture of e-cigarettes would further minimize the emission of metals from these devices and improve their safety and associated health effects.

  10. Recent Progress in Graphite Intercalation Compounds for Rechargeable Metal (Li, Na, K, Al)‐Ion Batteries

    Science.gov (United States)

    Xu, Jiantie; Dou, Yuhai; Wei, Zengxi; Li, Yutao; Liu, Huakun; Dou, Shixue

    2017-01-01

    Abstract Lithium‐ion batteries (LIBs) with higher energy density are very necessary to meet the increasing demand for devices with better performance. With the commercial success of lithiated graphite, other graphite intercalation compounds (GICs) have also been intensively reported, not only for LIBs, but also for other metal (Na, K, Al) ion batteries. In this Progress Report, we briefly review the application of GICs as anodes and cathodes in metal (Li, Na, K, Al) ion batteries. After a brief introduction on the development history of GICs, the electrochemistry of cationic GICs and anionic GICs is summarized. We further briefly summarize the use of cationic GICs and anionic GICs in alkali ion batteries and the use of anionic GICs in aluminium‐ion batteries. Finally, we reach some conclusions on the drawbacks, major progress, emerging challenges, and some perspectives on the development of GICs for metal (Li, Na, K, Al) ion batteries. Further development of GICs for metal (Li, Na, K, Al) ion batteries is not only a strong supplement to the commercialized success of lithiated‐graphite for LIBs, but also an effective strategy to develop diverse high‐energy batteries for stationary energy storage in the future. PMID:29051856

  11. Organic acid compounds in root exudation of Moso Bamboo (Phyllostachys pubescens) and its bioactivity as affected by heavy metals.

    Science.gov (United States)

    Chen, Junren; Shafi, Mohammad; Wang, Ying; Wu, Jiasen; Ye, Zhengqian; Liu, Chen; Zhong, Bin; Guo, Hua; He, Lizhi; Liu, Dan

    2016-10-01

    Moso bamboo (Phyllostachys pubescens) has great potential as phytoremediation material in soil contaminated by heavy metals. A hydroponics experiment was conducted to determine organic acid compounds of root exudates of lead- (Pb), zinc- (Zn), copper- (Cu), and cadmium (Cd)-tolerant of Moso bamboo. Plants were grown in nutrients solution which included Pb, Zn, Cu, and Cd applied as Pb(NO 3 ) 2 (200 μM), ZnSO 4 ·7H 2 O (100 μM), CuSO 4 ·5H 2 O (25 μM), and CdCl 2 (10 μM), respectively. Oxalic acid and malic acid were detected in all treatments. Lactic acid was observed in Cu, Cd, and control treatments. The oxalic was the main organic acid exudated by Moso bamboo. In the sand culture experiment, the Moso bamboo significantly activated carbonate heavy metals under activation of roots. The concentration of water-soluble metals (except Pb) in sand were significantly increased as compared with control. Organic acids (1 mM mixed) were used due to its effect on the soil adsorption of heavy metals. After adding mixed organic acids, the Cu and Zn sorption capacity in soils was decreased markedly compared with enhanced Pb and Cd sorption capacity in soils. The sorption was analyzed using Langmuir and Freundlich equations with R 2 values that ranged from 0.956 to 0.999 and 0.919 to 0.997, respectively.

  12. Metal and hydrogen catalysis in isotopic hydrogen exchange in some biologically important heterocyclic compounds

    International Nuclear Information System (INIS)

    Buncel, E.; Joly, H.A.; Jones, J.R.; Onyido, I.

    1989-01-01

    This study reports on the catalytic roles of metal and hydrogen ions in tritium exchange in some heterocyclic substrates which occur as residues in many biologically important molecules. We have found that detritiation of 1-methyl[2- 3 H]imidazole is inhibited by a number of metal ions. As well, inhibition of exchange rates was noted with Ag(I) and Cu(II) for [2- 3 H]thiazole and 1-methyl[8- 3 H]inosine, with Ag(I) for [2- 3 H]benzothiazole, and with Cu(II) for 1-methyl[8- 3 H]guanosine. A complete mechanistic description, which includes the various metal ion-coordinated species generated under the experimental conditions, is presented. The results demonstrate the reactivity order: protonated >> metal-coordinated >> neutral substrates. The differential catalytic effects of metal and hydrogen ions in these processes are discussed in terms of the extent of charge developed on the ligating heteroatom in the reaction intermediate. (author). 13 refs.; 1 fig

  13. Metal-insulator transition and magnetic properties of La - (Ba/Ca) - Mn - O compounds

    International Nuclear Information System (INIS)

    Anbarasu, V.; Manigandan, A.; Sathiyakumar, S.; Jayabalan, K.; Kaliyaperumal, L.K.

    2009-01-01

    The manganite compounds La 2 BaMn (3+x) P y (where x = 0, 0.5 and 1) and La 2 CaMn 3 O y have been prepared for the importance in the field of magneto resistance materials through solid-state reaction technique. From the Powder XRD patterns it was confirmed that both compounds were in single phase and the refined crystal system matches with superconducting perovskite structure and the lattice parameters were calculated as a = 3.892( 6) A, b = 3.899(3) A and c = 11.619(8) A for La 2 BaMn 3 O y ; a = 3.851(3) A, b = 3.891(9) A and c = 11.542(7) A for La 2 CaMn 3 O y . The low temperature resistivity measurement reveals that the compound La 2 BaMn 3 O y exhibiting M - I transition and the transition temperature was found to be 270 K. The study on magnetization nature of the La 2 BaMn 3+x Oy (where x = 0, 0.5 and I) compounds through vibrating sample magnetometer confirms the superparamagnetic nature at room temperature condition where as La 2 CaMn 3 O y exhibits paramagnetic nature. The structural relations between the prepared manganite systems La 2 BaMn 3 O y and La 2 CaMn 3 O y with superconducting perovskite compound LaBa 2 Cu 3 O 7-y was studied with the technological application of magneto resistive property of the prepared compounds. (author)

  14. Trends in air concentration and deposition at background monitoring sites in Sweden - major inorganic compounds, heavy metals and ozone

    Energy Technology Data Exchange (ETDEWEB)

    Kindbom, K.; Svensson, Annika; Sjoeberg, K.; Pihl Karlsson, G.

    2001-09-01

    This report describes concentrations in air of sulphur compounds, soot, nitrogen compounds and ozone in Sweden between 1985-1998. Time trends of concentration in precipitation and deposition of sulphate, nitrate, ammonium, acidity, base cations and chloride in six different regions covering Sweden are evaluated during the period 1983-1998. Trends of heavy metals in precipitation have been analysed for the period 1983-1998 and the change in heavy metal concentration, 1975-1995, in mosses is described. Data used in the trend analyses originates from measurements performed at six Swedish EMEP stations and from approximately 25 stations within the national Precipitation Chemistry Network. Two different statistical methods, linear regression and the non-parametric Mann Kendall test, have been used to evaluate changes in annual mean values. Time trends of concentration of sulphur dioxide, particulate sulphate, soot, nitrogen dioxide, total nitrate and total ammonium in air show highly significant decreasing trends, except for soot at one station in northern Sweden. Concentrations of ozone have a strong seasonal variation with a peak occurring in spring every year. However, annual ozone concentrations show no obvious trends in spite of decreasing emissions of the precursors NOx and VOC. A slight indication of a decreasing trend in the number of ozone episodes might be seen from 1990 to 1998. Sulphate concentrations in precipitation and deposition show strongly significant decreasing trends in the whole country. Concentrations and deposition of nitrate and ammonium have been decreasing in all areas except for nitrate at stations in south-west and north-west Sweden and ammonium in south-west Sweden. Acidity has decreased in all areas since 1989, resulting in increasing pH values in Sweden. The interannual variations of concentration and deposition of base cations and chloride are large and few general trends can be seen during 1983-1997. Time trends of four heavy metals in

  15. The effect of transition metals on the structure of h-BN intercalation compounds

    International Nuclear Information System (INIS)

    Budak, Erhan; Bozkurt, Cetin

    2004-01-01

    In this study, hexagonal boron nitride (h-BN) were synthesized by the modified O'Connor method in the presence of various metal nitrates [M(NO 3 ) x , M=Cr, Mn, Fe, Co, Ni, Cu, Zn, and Ag]. The composites were analyzed by FTIR, XRF, XRD, and SEM techniques. XRD results indicated a change in the interlayer spacing due to the intercalation of Cr, Mn, Fe and Ag. SEM analyses illustrated the grain growth upon metal intercalation even at a temperature of 1320 K

  16. Microbial transformations of natural organic compounds and radionuclides in subsurface environments

    International Nuclear Information System (INIS)

    Francis, A.J.

    1985-10-01

    A major national concern in the subsurface disposal of energy wastes is the contamination of ground and surface waters by waste leachates containing radionuclides, toxic metals, and organic compounds. Microorganisms play an important role in the transformation of organic compounds, radionuclides, and toxic metals present in the waste and affect their mobility in subsurface environments. Microbial processes involved in dissolution, mobilization, and immobilization of toxic metals under aerobic and anaerobic conditions are briefly reviewed. Metal complexing agents and several organic acids produced by microbial action affect mobilization of radionuclides and toxic metals in subsurface environments. Information on the persistence of and biodegradation rates of synthetic as well as microbiologically produced complexing agents is scarce but important in determining the mobility of metal organic complexes in subsoils. Several gaps in knowledge in the area of microbial transformation of naturally occurring organics, radionuclides, and toxic metals have been identified, and further basic research has been suggested. 31 refs., 1 fig., 3 tabs

  17. Effects of Ga substitution on the structural and magnetic properties of half metallic Fe{sub 2}MnSi Heusler compound

    Energy Technology Data Exchange (ETDEWEB)

    Pedro, S. S., E-mail: sandrapedro@uerj.br; Caraballo Vivas, R. J.; Andrade, V. M.; Cruz, C.; Paixão, L. S.; Contreras, C.; Costa-Soares, T.; Rocco, D. L.; Reis, M. S. [Instituto de Física, Universidade Federal Fluminense, Niterói-RJ (Brazil); Caldeira, L. [IF Sudeste MG, Campus Juiz de Fora - Núcleo de Física, Juiz de Fora-MG (Brazil); Coelho, A. A. [Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas - Unicamp, Campinas-SP (Brazil); Carvalho, A. Magnus G. [Laboratório Nacional de Luz Sincrotron, CNPEM, Campinas-SP (Brazil)

    2015-01-07

    The so-called half-metallic magnets have been proposed as good candidates for spintronic applications due to the feature of exhibiting a hundred percent spin polarization at the Fermi level. Such materials follow the Slater-Pauling rule, which relates the magnetic moment with the valence electrons in the system. In this paper, we study the bulk polycrystalline half-metallic Fe{sub 2}MnSi Heusler compound replacing Si by Ga to determine how the Ga addition changes the magnetic, the structural, and the half-metal properties of this compound. The material does not follow the Slater-Pauling rule, probably due to a minor structural disorder degree in the system, but a linear dependence on the magnetic transition temperature with the valence electron number points to the half-metallic behavior of this compound.

  18. Effects of heavy metals and nitroaromatic compounds on horseradish glutathione S-transferase and peroxidase

    Czech Academy of Sciences Publication Activity Database

    Nepovím, Aleš; Podlipná, Radka; Soudek, Petr; Schröder, P.; Vaněk, Tomáš

    2004-01-01

    Roč. 57, - (2004), s. 1007-1015 ISSN 0045-6535 R&D Projects: GA ČR GP206/02/P065; GA MŠk OC 837.10 Institutional research plan: CEZ:AV0Z4055905 Keywords : GST * POX * heavy metals Subject RIV: CE - Biochemistry Impact factor: 2.359, year: 2004

  19. Tunable hydrogen storage in magnesium-transition metal compounds: first-principles calculations

    NARCIS (Netherlands)

    Er, S.; Tiwari, Dhirendra; Tiwari, D.; de Wijs, Gilles A.; Brocks, G.

    2009-01-01

    Magnesium dihydride (MgH2) stores 7.7 wt % hydrogen but it suffers from a high thermodynamic stability and slow (de)hydrogenation kinetics. Alloying Mg with lightweight transition metals (TM) (=Sc,Ti,V,Cr) aims at improving the thermodynamic and kinetic properties. We study the structure and

  20. Analysis of sulphur, phosphorus and silica in metals, alloys, inorganic compounds and solvents

    International Nuclear Information System (INIS)

    Upadhya, J.C.; Naik, S.S.; Khedikar, W.K.; Sudersanan, M.; Mathur, P.K

    1999-10-01

    Procedures for the analysis of sulphur, phosphorus and silica in various metals and alloys like mild steel, carbon steel and stainless steel as well as nickel base alloys are described. Procedures were also developed for the analysis of sulphur in thoria pellets and in other materials like crack check fluids, coal etc. Typical results obtained are summarised. (author)

  1. Simultaneous removal of metals and organic compounds from a heavily polluted soil

    International Nuclear Information System (INIS)

    Szpyrkowicz, L.; Radaelli, M.; Bertini, S.; Daniele, S.; Casarin, F.

    2007-01-01

    The paper describes the results of treatment of soil samples, deriving from a dismissed industrial site, contaminated with several metals: Hg, Ni, Co, Zn, Pb, Cu, Cr, As and organic substances. The soil was subjected to remediation based on a process in which an oxidising leaching agent was produced electrochemically in-line in an undivided electrochemical cell reactor equipped with a Ti/Pt-Ir anode and a stainless steel cathode. Leaching of the soil samples was performed under dynamic conditions using a leaching column. A subsequent regeneration of the leaching solution, which consisted in electrodeposition of metals and electro-oxidation of organic substances, was carried out in a packed-bed reactor equipped with a centrally positioned graphite rod, serving as an anode, and stainless steel three-dimensional filling as a cathode. The study was focused on how and to which extent the metals present in the soil, as organic complexes, can be solubilised and how the process rates are impacted by the solution pH and other process variables. Data obtained under non-oxidising conditions, typically adopted for leaching of metals, are compared with the performance of chlorine-enriched leaching solutions. The results obtained under various conditions are also discussed in terms of the total organic carbon (TOC) removal from the water phase

  2. Transition-Metal-Mediated or -Catalyzed Syntheses of Steroids and Steroid-Like Compounds

    Czech Academy of Sciences Publication Activity Database

    Kotora, Martin; Hessler, F.; Eignerová, B.

    -, č. 1 (2012), s. 29-42 ISSN 1434-193X R&D Projects: GA MŠk 1M0508 Institutional research plan: CEZ:AV0Z40550506 Keywords : steroids * synthesis design * synthetic methods * asymmetric synthesis * transition metals Subject RIV: CC - Organic Chemistry Impact factor: 3.344, year: 2012

  3. Effects of metallic nanoparticle doped flux on the interfacial intermetallic compounds between lead-free solder ball and copper substrate

    International Nuclear Information System (INIS)

    Sujan, G.K.; Haseeb, A.S.M.A.; Afifi, A.B.M.

    2014-01-01

    Lead free solders currently in use are prone to develop thick interfacial intermetallic compound layers with rough morphology which are detrimental to the long term solder joint reliability. A novel method has been developed to control the morphology and growth of intermetallic compound layers between lead-free Sn–3.0Ag–0.5Cu solder ball and copper substrate by doping a water soluble flux with metallic nanoparticles. Four types of metallic nanoparticles (nickel, cobalt, molybdenum and titanium) were used to investigate their effects on the wetting behavior and interfacial microstructural evaluations after reflow. Nanoparticles were dispersed manually with a water soluble flux and the resulting nanoparticle doped flux was placed on copper substrate. Lead-free Sn–3.0Ag–0.5Cu solder balls of diameter 0.45 mm were placed on top of the flux and were reflowed at a peak temperature of 240 °C for 45 s. Angle of contact, wetting area and interfacial microstructure were studied by optical microscopy, field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. It was observed that the angle of contact increased and wetting area decreased with the addition of cobalt, molybdenum and titanium nanoparticles to flux. On the other hand, wettability improved with the addition of nickel nanoparticles. Cross-sectional micrographs revealed that both nickel and cobalt nanoparticle doping transformed the morphology of Cu 6 Sn 5 from a typical scallop type to a planer one and reduced the intermetallic compound thickness under optimum condition. These effects were suggested to be related to in-situ interfacial alloying at the interface during reflow. The minimum amount of nanoparticles required to produce the planer morphology was found to be 0.1 wt.% for both nickel and cobalt. Molybdenum and titanium nanoparticles neither appear to undergo alloying during reflow nor have any influence at the solder/substrate interfacial reaction. Thus, doping of flux

  4. Effects of metallic nanoparticle doped flux on the interfacial intermetallic compounds between lead-free solder ball and copper substrate

    Energy Technology Data Exchange (ETDEWEB)

    Sujan, G.K., E-mail: sgkumer@gmail.com; Haseeb, A.S.M.A., E-mail: haseeb@um.edu.my; Afifi, A.B.M., E-mail: amalina@um.edu.my

    2014-11-15

    Lead free solders currently in use are prone to develop thick interfacial intermetallic compound layers with rough morphology which are detrimental to the long term solder joint reliability. A novel method has been developed to control the morphology and growth of intermetallic compound layers between lead-free Sn–3.0Ag–0.5Cu solder ball and copper substrate by doping a water soluble flux with metallic nanoparticles. Four types of metallic nanoparticles (nickel, cobalt, molybdenum and titanium) were used to investigate their effects on the wetting behavior and interfacial microstructural evaluations after reflow. Nanoparticles were dispersed manually with a water soluble flux and the resulting nanoparticle doped flux was placed on copper substrate. Lead-free Sn–3.0Ag–0.5Cu solder balls of diameter 0.45 mm were placed on top of the flux and were reflowed at a peak temperature of 240 °C for 45 s. Angle of contact, wetting area and interfacial microstructure were studied by optical microscopy, field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. It was observed that the angle of contact increased and wetting area decreased with the addition of cobalt, molybdenum and titanium nanoparticles to flux. On the other hand, wettability improved with the addition of nickel nanoparticles. Cross-sectional micrographs revealed that both nickel and cobalt nanoparticle doping transformed the morphology of Cu{sub 6}Sn{sub 5} from a typical scallop type to a planer one and reduced the intermetallic compound thickness under optimum condition. These effects were suggested to be related to in-situ interfacial alloying at the interface during reflow. The minimum amount of nanoparticles required to produce the planer morphology was found to be 0.1 wt.% for both nickel and cobalt. Molybdenum and titanium nanoparticles neither appear to undergo alloying during reflow nor have any influence at the solder/substrate interfacial reaction. Thus, doping

  5. Synchrotron Diffraction Studies of Spontaneous Magnetostriction in Rare Earth Transition Metal Compounds

    International Nuclear Information System (INIS)

    Ning Yang

    2004-01-01

    Thermal expansion anomalies of R 2 Fe 14 B and R 2 Fe 17 C x (x = 0,2) (R Y, Nd, Gd, Tb, Er) stoichiometric compounds are studied with high-energy synchrotron X-ray powder diffraction using Debye-Schemer geometry in temperature range 10K to 1000K. Large spontaneous magnetostriction up to their Curie temperatures (T c ) is observed. The a-axes show relatively larger invar effects than c-axes in the R 2 Fe 14 B compounds whereas the R 2 Fe 17 C x show the contrary anisotropies. The iron sub-lattice is shown to dominate the spontaneous magnetostriction of the compounds. The contribution of the rare earth sublattice is roughly proportional to the spin magnetic moment of the rare earth in the R 2 Fe 14 B compounds but in R 2 Fe 17 C x , the rare earth sub-lattice contribution appears more likely to be dominated by the local bonding. The calculation of spontaneous magnetostrain of bonds shows that the bonds associated with Fe(j2) sites in R 2 Fe 14 B and the dumbbell sites in R 2 Fe 17 C x have larger values, which is strongly related to their largest magnetic moment and Wigner-Seitz atomic cell volume. The roles of the carbon atoms in increasing the Curie temperatures of the R 2 Fe 17 compounds are attributed to the increased separation of Fe hexagons. The R 2 Fe 17 and R 2 Fe 14 B phases with magnetic rare earth ions also show anisotropies of thermal expansion above T c . For R 2 Fe 17 and R 2 Fe 14 B the a a /a c > 1 whereas the anisotropy is reversed with the interstitial carbon in R 2 Fe 17 . The average bond magnetostrain is shown to be a possible predictor of the magnetic moment of Fe sites in the compounds. Both of the theoretical and phenomenological models on spontaneous magnetostriction are discussed and a Landau model on the spontaneous magnetostriction is proposed

  6. Large scale simulations of the mechanical properties of layered transition metal ternary compounds for fossil energy power system applications

    Energy Technology Data Exchange (ETDEWEB)

    Ching, Wai-Yim [Univ. of Missouri, Kansas City, MO (United States)

    2014-12-31

    Advanced materials with applications in extreme conditions such as high temperature, high pressure, and corrosive environments play a critical role in the development of new technologies to significantly improve the performance of different types of power plants. Materials that are currently employed in fossil energy conversion systems are typically the Ni-based alloys and stainless steels that have already reached their ultimate performance limits. Incremental improvements are unlikely to meet the more stringent requirements aimed at increased efficiency and reduce risks while addressing environmental concerns and keeping costs low. Computational studies can lead the way in the search for novel materials or for significant improvements in existing materials that can meet such requirements. Detailed computational studies with sufficient predictive power can provide an atomistic level understanding of the key characteristics that lead to desirable properties. This project focuses on the comprehensive study of a new class of materials called MAX phases, or Mn+1AXn (M = a transition metal, A = Al or other group III, IV, and V elements, X = C or N). The MAX phases are layered transition metal carbides or nitrides with a rare combination of metallic and ceramic properties. Due to their unique structural arrangements and special types of bonding, these thermodynamically stable alloys possess some of the most outstanding properties. We used a genomic approach in screening a large number of potential MAX phases and established a database for 665 viable MAX compounds on the structure, mechanical and electronic properties and investigated the correlations between them. This database if then used as a tool for materials informatics for further exploration of this class of intermetallic compounds.

  7. A Stable, Magnetic, and Metallic Li3O4 Compound as a Discharge Product in a Li-Air Battery.

    Science.gov (United States)

    Yang, Guochun; Wang, Yanchao; Ma, Yanming

    2014-08-07

    The Li-air battery with the specific energy exceeding that of a Li ion battery has been aimed as the next-generation battery. The improvement of the performance of the Li-air battery needs a full resolution of the actual discharge products. Li2O2 has been long recognized as the main discharge product, with which, however, there are obvious failures on the understanding of various experimental observations (e.g., magnetism, oxygen K-edge spectrum, etc.) on discharge products. There is a possibility of the existence of other Li-O compounds unknown thus far. Here, a hitherto unknown Li3O4 compound as a discharge product of the Li-air battery was predicted through first-principles swarm structure searching calculations. The new compound has a unique structure featuring the mixture of superoxide O2(-) and peroxide O2(2-), the first such example in the Li-O system. The existence of superoxide O2(-) creates magnetism and hole-doped metallicity. Findings of Li3O4 gave rise to direct explanations of the unresolved experimental magnetism, triple peaks of oxygen K-edge spectra, and the Raman peak at 1125 cm(-1) of the discharge products. Our work enables an opportunity for the performance of capacity, charge overpotential, and round-trip efficiency of the Li-air battery.

  8. Hybrid compounds of Keggin polyoxotungstate with transition metal ion as the central atom. Synthesis, structure and properties

    Science.gov (United States)

    Li, Xiao-Min; Chen, Ya-Guang; Shi, Tian

    2016-02-01

    The compounds (Hbipy)2[Co(bipy)2(H2O)4]2(CoW12O40)·2bipy·7H2O (1) and [Ni2(Hbipy)2(bipy)(H2O)4(H2W12O40)]·5H2O (2) (bipy = 4,4-bipyridine) were synthesized hydrothermally and characterized by elemental analysis, IR spectroscopy, TG analyses, solid ultraviolet diffuse spectroscopy and single crystal X-ray diffraction method. In 1 the complex ions, [Co(bipy)2(H2O)4]2+, construct a supramolecular layer through π-π stacking interaction. The heteropolyanions with central Co atom and supramolecular layers are linked by hydrogen bonds. In 2 a 2D structure is formed from metatungstate anions and binuclear Ni-bipy complexes through the coordination of metatungstate anions and bipy to Ni ions. Between the layers and bipyridine molecules are the hydrogen bond interactions. The formation of 1 and 2 shows that the solution acidity and metal ions influence greatly the structure of the compounds. Solid ultraviolet diffusion results indicate that the compounds 1 and 2 are potential semiconductor materials. In 1 and 2 there exists a weak antiferromagnetic interaction.

  9. Immobilized enzymes and cells

    Energy Technology Data Exchange (ETDEWEB)

    Bucke, C; Wiseman, A

    1981-04-04

    This article reviews the current state of the art of enzyme and cell immobilization and suggests advances which might be made during the 1980's. Current uses of immobilized enzymes include the use of glucoamylase in the production of glucose syrups from starch and glucose isomerase in the production of high fructose corn syrup. Possibilities for future uses of immobilized enzymes and cells include the utilization of whey and the production of ethanol.

  10. Loadings of polynuclear aromatic compounds and metals to the Athabasca River watershed by oil sands mining and processing

    International Nuclear Information System (INIS)

    Hodson, P.V.

    2010-01-01

    The contribution of oil sands operations to pollution in the Athabasca River has not yet been determined. Wastes from oil sands processes include recycled water, sand, silt, clay, bitumen, and polycyclic aromatic compounds (PAC) and metals. Upgrading processes can also release significant quantities of PAC and heavy metals. This paper discussed a study in which PAC and metals in the snow pack and river water of the Athabasca watershed were assessed. The study showed that the oil sands industry is a significant source of contamination. The equivalent of 600 T of bitumen was observed at sites within 50 km of oil sands upgrading facilities. The strongest contamination signals occurred during the summer months, which suggested that the surface run-off of contaminated water was related to recent oil sands developments. Samples taken from tributaries in watersheds with little or no development indicated that increased concentrations of oil sands related contaminants were not caused by natural erosion. The contaminants may contribute to higher levels of mercury (Hg) and cadmium (Cd) in the flesh of fish and wildlife and increase toxicity to the embryos of spring-spawning fish.

  11. Volatile organic compounds and trace metal level in some beers collected from Romanian market

    Science.gov (United States)

    Voica, Cezara; Kovacs, Melinda; Vadan, Marius

    2013-11-01

    Beer is one of the most popular beverages at worldwide level. Through this study fifteen different types of beer collected from Romanian market were analysed in order to evaluate their mineral, trace element as well the their organic content. Importance of such characterization of beer samples is supported by the fact that their chemical composition can affect both taste and stability of beer, as well the consumer health. Minerals and trace elements analysis were performed on ICP-MS while organic compounds analysis was done through GC-MS. Through ICP-MS analysis, elements as Ca, Na, K and Mg were evidenced at mgṡkg-1 order while elements as Cr, Ba, Co, Ni were detected at lower level. After GC-MS analysis the major volatile compounds that were detected belong to alcohols namely ethanol, propanol, isobutanol, isoamyl alcohol and linalool. Selected fatty acids and esters were evidenced also in the studied beer samples.

  12. The importance of atomic and molecular correlation on the bonding in transition metal compounds

    Science.gov (United States)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Walch, Stephen P.

    1986-01-01

    The determination of accurate spectroscopic parameters for molecular systems containing transition metal atoms is shown to require extensive data sets and a high level correlation treatment, and techniques and their limitations are considered. Extensive results reported on the transition metal atoms, hydrides, oxides, and dimers makes possible the design of a calculation to correctly describe the mixing of different atomic asymptotes, and to give a correct balance between molecular bonding and exchange interactions. Examples considered include the dipole moment of the 2Delta state of NiH, which can help determine the mixture of 3d(8)4s(2) and 3d(9)4s(1) in the NiH wavefunction, and the bonding in CrO, where an equivalent description of the relative energies associated with the Cr 3d-3d atomic exchange and the Cr-O bond is important.

  13. Development of fluoric compound treatment system in conversion for recycle in metal industry

    International Nuclear Information System (INIS)

    Kim, P.O.; Cho, N.C.

    1998-01-01

    Korea Nuclear Fuel Company (KNFC) has been operating AUC conversion process from UF 6 to UO 2 from 1990. In 1997, KNFC constructed another conversion line called dry conversion to meet the increasing demand for nuclear fuel fabrication. In the dry conversion, two kinds of hydrofluoric acid (HF) are produced as a by-product. The first one is 50% concentration HF and the other one is diluted HF ranging from 10% to 49%. The high concentration HF can be used in metal industry, but there is no use for diluted one. The diluted HF should be disposed of as liquid waste after some treatment. To solve this problem we have developed the process to convert the diluted hydrofluoric acid to the sodium fluoride, which is readily used in the metal industry. By developing the process we could make a contribution to the environment as well as cost reduction in manufacturing nuclear fuel. (author)

  14. The Transition Metal-Like Reactivity of Low Oxidation State s- and p-Block Compounds

    Science.gov (United States)

    2017-10-20

    suggestions for reducing the burden, to Department of Defense, Executive Services, Directorate (0704-0188).   Respondents should be aware that...amide ligands. These compounds were used as reagents for catalytic transformation of small molecules. The PI was able to publish 19 papers in...Significant Collaborations that resulted from your AOARD supported project (see attachments): a) papers published in, or submitted to, peer-reviewed

  15. Structure of metal-rich (001) surfaces of III-V compound semiconductors

    DEFF Research Database (Denmark)

    Kumpf, C.; Smilgies, D.; Landemark, E.

    2001-01-01

    The atomic structure of the group-III-rich surface of III-V semiconductor compounds has been under intense debate for many years, yet none of the models agrees with the experimental data available. Here we present a model for the three-dimensional structure of the (001)-c(8x2) reconstruction on In......(8 x 2) reconstructions of III-V semiconductor surfaces contain the same essential building blocks....

  16. The interaction of metal carbonyl compounds with organic polymers and monomers

    OpenAIRE

    Lyons, Michael P.

    1993-01-01

    The photochemistry of W(CO)6, Mo(CO)6, and Cr(CO)6 in the presence of monomeric and polymeric triphenylphosphine ligands was investigated in toluene solution, using laser flash photolysis with 355nm excitation. The mechanism and kinetics of interaction of the primary photoproducts M(CO)5(toluene) (M = W, Mo, or Cr) with the various monomeric ligands were investigated. Interaction of the metal carbonyl photofragments with various homopolymers is also discussed. The polymerisation methods used ...

  17. The use of dialdehyde starch derivatives in the phytoremediation of soils contaminated with heavy metals.

    Science.gov (United States)

    Antonkiewicz, Jacek; Para, Andrzej

    2016-01-01

    Products of the reaction between dialdehyde starch and Y-NH2 compounds (e.g. semicarbazide or hydrazine) are effective ligands for metal ions. The usefulness of these derivatives was tested in the experiment, both in terms of the immobilization of heavy metal ions in soil and the potential application in phytoextraction processes. The experimental model comprised maize and the ions of such metals as: Zn(II), Pb(II), Cu(II), Cd(II), and Ni(II). The amount of maize yield, as well as heavy metal content and uptake by the aboveground parts and roots of maize, were studied during a three-year pot experiment. The results of the study indicate the significant impact of heavy metals on reduced yield and increased heavy metal content in maize. Soil-applied dialdehyde starch derivatives resulted in lower yields, particularly disemicarbazone (DASS), but in heavy metal-contaminated soils they largely limited the negative impact of these metals both on yielding and heavy metal content in plants, particularly dihydrazone (DASH). It was demonstrated that the application of dihydrazone (DASH) to a soil polluted with heavy metals boosted the uptake of Zn, Pb, Cu, and Cd from the soil, hence there is a possibility to use this compound in the phytoextraction of these metals from the soil. Decreased Ni uptake was also determined, hence the possibility of using this compound in the immobilization of this metal. The study showed that dialdehyde starch disemicarbazone was ineffective in the discussed processes.

  18. Precise coulometric titration of uranium in a high-purity uranium metal and in uranium compounds

    International Nuclear Information System (INIS)

    Tanaka, Tatsuhiko; Yoshimori, Takayoshi

    1975-01-01

    Uranium in uranyl nitrate, uranium trioxide and a high-purity uranium metal was assayed by the coulometric titration with biamperometric end-point detection. Uranium (VI) was reduced to uranium (IV) by solid bismuth amalgam in 5M sulfuric acid solution. The reduced uranium was reoxidized to uranium (VI) with a large excess of ferric ion at a room temperature, and the ferrous ion produced was titrated with the electrogenerated manganese(III) fluoride. In the analyses of uranium nitrate and uranium trioxide, the results were precise enough when the error from uncertainty in water content in the samples was considered. The standard sample of pure uranium metal (JAERI-U4) was assayed by the proposed method. The sample was cut into small chips of about 0.2g. Oxides on the metal surface were removed by the procedure shown by National Bureau of Standards just before weighing. The mean assay value of eleven determinations corrected for 3ppm of iron was (99.998+-0.012) % (the 95% confidence interval for the mean), with a standard deviation of 0.018%. The proposed coulometric method is simple and permits accurate and precise determination of uranium which is matrix constituent in a sample. (auth.)

  19. Metal compounds in zeolites as active components of chemisorption and catalysis. Quantum chemical approach

    International Nuclear Information System (INIS)

    Zhidomirov, G.M.

    1996-01-01

    A short review of possible catalitic active sites associated with various types of metal species in zoolite is presented. The structural and electronic peculiarity of aluminum ions in zeolite lattice and their distribution in the lattice are discussed on the basis of quantum chemical calculations in connection with the formation of Broensted activity of zeolites. Various molecular models of Lewis Acid Sites associated the extra-lattice oxide-hydroxide aluminum species have been investigated by means of density functional model cluster calculations using CO molecule as a probe. Probable ways of formation of the selective oxidation center in FeZSM-5 by decomposition of dinitrogen monoxide have been studied by ab-initio quantum chemical calculations. The immediate oxidizing site is reasonably represented by the binuclear iron-hydroxide cluster with peroxo-like fragment located between iron atoms. Various probable intermediates of the selective oxidation center formation resulted from interaction of a hydroperoxide molecule with a lattice titanium ion in titanium silicalite have been investigated by quantum chemical calculations. It was concluded that this reaction requires essential structural reconstruction in the vicinity of the titanium ion. Probability of this structural reconstruction is discussed. Possible reasons of an electron-deficient and electron-enriched state of metal particles entrapped in zoolite cavities are discussed. Also, various probable molecular models of such modified metal particles in zeolite are considered

  20. Developments in Bioremediation of Soils and Sediments Polluted with Metals and Radionuclides - 3. Influence of Chemical Speciation and Bioavailability on Contaminants Immobilization/mobilization Bio-processes

    NARCIS (Netherlands)

    Hullebusch, van E.D.; Lens, P.N.L.; Tabak, H.H.

    2005-01-01

    The biotransformation of metals is an exciting, developing strategy to treat metal contamination, especially in environments that are not accessible to other remediation technologies. However, our ability to benefit from these strategies hinges on our ability to monitor these transformations in the

  1. Biotechnological production of vanillin using immobilized enzymes.

    Science.gov (United States)

    Furuya, Toshiki; Kuroiwa, Mari; Kino, Kuniki

    2017-02-10

    Vanillin is an important and popular plant flavor, but the amount of this compound available from plant sources is very limited. Biotechnological methods have high potential for vanillin production as an alternative to extraction from plant sources. Here, we report a new approach using immobilized enzymes for the production of vanillin. The recently discovered oxygenase Cso2 has coenzyme-independent catalytic activity for the conversion of isoeugenol and 4-vinylguaiacol to vanillin. Immobilization of Cso2 on Sepabeads EC-EA anion-exchange carrier conferred enhanced operational stability enabling repetitive use. This immobilized Cso2 catalyst allowed 6.8mg yield of vanillin from isoeugenol through ten reaction cycles at a 1mL scale. The coenzyme-independent decarboxylase Fdc, which has catalytic activity for the conversion of ferulic acid to 4-vinylguaiacol, was also immobilized on Sepabeads EC-EA. We demonstrated that the immobilized Fdc and Cso2 enabled the cascade synthesis of vanillin from ferulic acid via 4-vinylguaiacol with repetitive use of the catalysts. This study is the first example of biotechnological production of vanillin using immobilized enzymes, a process that provides new possibilities for vanillin production. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. A method for hydrogenating and carbonylizing unsaturated compounds in the presence of catalysts based on phosphine and metal complexes

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, J C; Dyer, G

    1982-12-22

    The hydrogenation of unsaturated organic compounds or the attachment to them of CO is accomplished with contact with a synthesis gas in the presence of a stereospecific catalyst (Kt), a compound of a metal of the platinum group (preferably Rhodium, but also Platinum, Palladium, Ruthenium or Iridium) and an asymmetrical bis-phosphine of the formula A-(CH2)n-B, where A and B are phosphine groups. R2P and R'2P or RRhP, where R is an aryl radical, R' is aralkyl, alcarylic or alkyl radical, n = 1 to 10, or an asymmetrical monophosphine of the formula R2-R'P. The complex compound also includes Hydrogen, CO and (or) halogen (preferably Chlorine) as ligands. The physical properties of the obtained complex compounds of the carbonylchlorbisphosphines or Rh are presented: trans-(RhC1-(CO)(Ph2P(CH2)6PPh2))2; trans-(RhC1(CO)(C2H5PhP-(CH2)6PPh2))2; trans-(RhC1(CO)(cycloC6H11PhP(CH2)6-PPh2))2; trans-(RhC1(CO)(C2H5PhP(CH2)4PPh2)2; trans-(RhC1(CO)(C2H5PhP(Ch2))2 and PhC1(CO)4(p-C6H4CH2)2P(Ch2)6PPh2). The isolated complexes are light yellow crystalline substances.

  3. Synchrotron Diffraction Studies of Spontaneous Magnetostriction in Rare Earth Transition Metal Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ning [Iowa State Univ., Ames, IA (United States)

    2004-12-19

    Thermal expansion anomalies of R2Fe14B and R2Fe17Cx (x = 0,2) (R = Y, Nd, Gd, Tb, Er) stoichiometric compounds are studied with high-energy synchrotron X-ray powder diffraction using Debye-Schemer geometry in temperature range 10K to 1000K. Large spontaneous magnetostriction up to their Curie temperatures (Tc) is observed. The a-axes show relatively larger invar effects than c-axes in the R2Fe14B compounds whereas the R2Fe17Cx show the contrary anisotropies. The iron sub-lattice is shown to dominate the spontaneous magnetostriction of the compounds. The contribution of the rare earth sublattice is roughly proportional to the spin magnetic moment of the rare earth in the R2Fe14B compounds but in R2Fe17Cx, the rare earth sub-lattice contribution appears more likely to be dominated by the local bonding. The calculation of spontaneous magnetostrain of bonds shows that the bonds associated with Fe(j2) sites in R2Fe14B and the dumbbell sites in R2Fe17Cx have larger values, which is strongly related to their largest magnetic moment and Wigner-Seitz atomic cell volume. The roles of the carbon atoms in increasing the Curie temperatures of the R2Fe17 compounds are attributed to the increased separation of Fe hexagons. The R2Fe17 and R2Fe14B phases with magnetic rare earth ions also show anisotropies of thermal expansion above c. For R2Fe17 and R2Fe14B the a a/a c > 1 whereas the anisotropy is reversed with the interstitial carbon in R2Fe17. The average bond magnetostrain is shown to be a possible predictor of the magnetic moment of Fe sites in the compounds. Both of the theoretical and

  4. Rapid coastal survey of anthropogenic radionuclides, metals, and organic compounds in surficial marine sediments

    International Nuclear Information System (INIS)

    Noakes, J.E.; Noakes, S.E.; Dvoracek, D.K.; Culp, R.A.; Bush, P.B.

    1999-01-01

    A towed survey system, the GIMS/CS 3 , has been developed to enable the rapid measurement and mapping of a variety of physical and geochemical parameters in the surficial sediments of aquatic environments while the survey vessel is underway. With its capability for measuring radiometric, elemental and organic compound constituents of sediments, as well as bathymetry and water quality parameters, the GIMS/CS 3 provides a cost-effective means of performing reconnaissance determinations of contaminant distributions and environmental monitoring tasks over broad geographic regions

  5. Pressure-induced metal-insulator transition in spinel compound CuV2S4

    International Nuclear Information System (INIS)

    Okada, H.; Koyama, K.; Hedo, M.; Uwatoko, Y.; Watanabe, K.

    2008-01-01

    In order to investigate the pressure effect on electrical properties of CuV 2 S 4 , we performed the electrical resistivity measurements under high pressures up to 8 GPa for a high-quality polycrystalline sample. The charge density wave (CDW) transition temperatures increase with increasing pressure. The residual resistivity rapidly increases with increasing pressure over 4 GPa, and the temperature dependence of the electrical resistivity at 8 GPa exhibits a semiconducting behavior below about 150 K, indicating that a pressure-induced metal-insulator transition occurs in CuV 2 S 4 at 8 GPa

  6. Ambient air monitoring for organic compounds, acids, and metals at Los Alamos National Laboratory, January 1991

    International Nuclear Information System (INIS)

    Williams, C.H.; Eberhart, C.F.

    1992-01-01

    Los Alamos National Laboratory (LANL) contracted Radian Corporation (Radian) to conduct a short-term, intensive air monitoring program whose goal was to estimate the impact of chemical emissions from LANL on the ambient air environment. A comprehensive emission inventory had identified more than 600 potential air contaminants in LANL's emissions. A subset of specific target chemicals was selected for monitoring: 20 organic vapors, 6 metals and 5 inorganic acid vapors. These were measured at 5 ground level sampling sites around LANL over seven consecutive days in January 1991. The sampling and analytical strategy used a combination of EPA and NIOSH methods modified for ambient air applications

  7. Theoretical modelling of intermediate band solar cell materials based on metal-doped chalcopyrite compounds

    International Nuclear Information System (INIS)

    Palacios, P.; Sanchez, K.; Conesa, J.C.; Fernandez, J.J.; Wahnon, P.

    2007-01-01

    Electronic structure calculations are carried out for CuGaS 2 partially substituted with Ti, V, Cr or Mn to ascertain if some of these systems could provide an intermediate band material able to give a high efficiency photovoltaic cell. Trends in electronic level positions are analyzed and more accurate advanced theory levels (exact exchange or Hubbard-type methods) are used in some cases. The Ti-substituted system seems more likely to yield an intermediate band material with the desired properties, and furthermore seems realizable from the thermodynamic point of view, while those with Cr and Mn might give half-metal structures with applications in spintronics

  8. Theoretical modelling of intermediate band solar cell materials based on metal-doped chalcopyrite compounds

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, P [Instituto de Energia Solar and Dpt. de Tecnologias Especiales, ETSI de Telecomunicacion, UPM, Ciudad Universitaria s/n, 28040 Madrid (Spain); Sanchez, K [Instituto de Energia Solar and Dpt. de Tecnologias Especiales, ETSI de Telecomunicacion, UPM, Ciudad Universitaria s/n, 28040 Madrid (Spain); Conesa, J C [Instituto de Catalisis y Petroleoquimica, CSIC, Marie Curie 2, Cantoblanco, 28049 Madrid (Spain); Fernandez, J J [Dpt. de Fisica Fundamental, Universidad Nacional de Educacion a Distancia, 28080, Madrid (Spain); Wahnon, P [Instituto de Energia Solar and Dpt. de Tecnologias Especiales, ETSI de Telecomunicacion, UPM, Ciudad Universitaria s/n, 28040 Madrid (Spain)

    2007-05-31

    Electronic structure calculations are carried out for CuGaS{sub 2} partially substituted with Ti, V, Cr or Mn to ascertain if some of these systems could provide an intermediate band material able to give a high efficiency photovoltaic cell. Trends in electronic level positions are analyzed and more accurate advanced theory levels (exact exchange or Hubbard-type methods) are used in some cases. The Ti-substituted system seems more likely to yield an intermediate band material with the desired properties, and furthermore seems realizable from the thermodynamic point of view, while those with Cr and Mn might give half-metal structures with applications in spintronics.

  9. Analysis of metals in organic compounds by energy dispersive X-ray fluorescence analysis

    International Nuclear Information System (INIS)

    Anjos, Marcelino J.; Lopes, Ricardo T.; Jesus, Edgar F.O. de

    2000-01-01

    Using energy dispersive X-ray fluorescence analysis with an X-ray tube filtered with Ti. It was possible to determine the concentration of the elements at ppm level of several elements: K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn As, Rb, Sr, Y, Zr, and Pb in two types of organic compound enough used in the agriculture: organic compound of urban garbage (Fertilurb) and aviary bed (birds manure). The experimental setup is composed of: x-ray tube (Oxford, 30 kV, 50 μA and W anode), an ORTEC Si-Li detector, with an energy resolution of about 180 eV at 5.9 keV and an ORTEC multichannel-analyser. The X-ray beam is quasi- monochromatic by using Ti filter. The samples were prepared in pellet form with superficial density in the range of 100 mg/cm 2 . The fundamental parameter method was used in order to verify the elemental concentration. The radiation transmission method was going used to the radiation absorption effects correction in the samples. (author)

  10. Complexing in the systems of thorium tetrabromide-alkali metal bromide and structure of formed compounds

    International Nuclear Information System (INIS)

    Gershanovich, A.Ya.; Suglobova, I.G.

    1981-01-01

    Phase diagrams of the ThBr 4 -MBr binary systems (M=Na, K, Rb, Cs) are obtained using the methods of thermographic and X-ray phase analyses. Congruently melting compounds of the M 2 ThBr 6 form (M=K, Rb, Cs) with melting temperatures of 635, 650 and 680 deg C, respectively, and the NaThBr 5 decomposing in the solid phase reaction at 356 deg C, realized in the systems. The presence of eutectic points is established, their composition and melting temperatures are determined. Roentgenograms of all compounds prepared by the polycrystal method are obtained. K 2 ThBr 6 and Rb 2 ThBr 6 crystallize in the hexagonal crystal system (Rb 2 MnF 6 structure type) with 2 formula units in the lattice cell. The parameters of the K 2 ThBr 6 cell are a=0.752 nm, c=1.180 nm. The cell parameters of the Rb 2 ThBr 6 cell are a=0.758 nm, c=1.224 nm. The Cs 2 ThBr 6 has a pseudocubic tetragonal structure with 4 formula units in a cell. Parameters of the Cs 2 ThBr 6 cell are a=1.137 nm; c=1.069 nm [ru

  11. First-principles calculations: The elemental transition metals and their compounds

    International Nuclear Information System (INIS)

    Watson, R.E.; Fernando, G.W.; Weinert, M.; Davenport, J.W.

    1991-01-01

    If done with sufficient care, present day a priori theory yields calculated enthalpies of formation whose agreement with experiment (when such data is available) is of the order of the experimental scatter. Comparisons will be made for the Pt-Ti systems for which such data exist and for which one crystal structure involves atomics sites of low symmetry. Two other cases will be considered for which there is no direct experimental heats data. The first of these will be the structural stabilities of the 4d elemental metals. Such structural stabilities have been an issue of contention between electronic structure theorists and those who construct phase diagrams for some twenty-five years. The second involves the energetics of forming metal adlayers and artificial multilayers. The distortion energies associated with the requirement that adlayers (or multilayers) conform to some given substrate are often the controlling factors in the fabrication of multilayer materials. This contribution is best understood by invoking a combination of elemental structural promotion energies plus elastic distortions from these structures. As will be seen, the fabrication of multilayers also involves a term not normally encountered in bulk phase diagram considerations, namely the difference in surface energies of the two multilayer constituents. 22 refs., 4 figs

  12. First-principles calculations: The elemental transition metals and their compounds

    Energy Technology Data Exchange (ETDEWEB)

    Watson, R.E.; Fernando, G.W.; Weinert, M.; Davenport, J.W.

    1991-01-01

    If done with sufficient care, present day a priori theory yields calculated enthalpies of formation whose agreement with experiment (when such data is available) is of the order of the experimental scatter. Comparisons will be made for the Pt-Ti systems for which such data exist and for which one crystal structure involves atomics sites of low symmetry. Two other cases will be considered for which there is no direct experimental heats data. The first of these will be the structural stabilities of the 4d elemental metals. Such structural stabilities have been an issue of contention between electronic structure theorists and those who construct phase diagrams for some twenty-five years. The second involves the energetics of forming metal adlayers and artificial multilayers. The distortion energies associated with the requirement that adlayers (or multilayers) conform to some given substrate are often the controlling factors in the fabrication of multilayer materials. This contribution is best understood by invoking a combination of elemental structural promotion energies plus elastic distortions from these structures. As will be seen, the fabrication of multilayers also involves a term not normally encountered in bulk phase diagram considerations, namely the difference in surface energies of the two multilayer constituents. 22 refs., 4 figs.

  13. Fe based amorphous and compounds metallic alloys for magnetic and structural use

    International Nuclear Information System (INIS)

    Lavorato, G; Bassi, F; De Rosa, H; Moya, J

    2008-01-01

    Massive amorphous metals (thicker than 1mm) are new types of material that could have a wide range of future applications due to a unique combination of their physical properties, mechanics and magnetics. Among these are the elevated tension of fracture and hardness, and excellent soft magnetic properties. Since 1960, when an amorphous metallic alloy was first discovered, progress has continued on the application possibilities for these materials. One of their main limitations, maximum obtainable thickness, has continued to increase, since at first thicknesses of a few microns were obtained. Now amorphous alloys more than 70 mm thick are obtained using different metallic elements. Since 1995 massive amorphous metals can be produced using Fe as the base element. At first they were made in order to achieve good soft magnetic properties (thicknesses of ∼5 mm) and later a renewed interest in their use as structural material led to the development of materials with thicknesses of 16 mm and paramagnetics at room temperature. Increasing the toughness of these materials is also a challenge and investigators have proposed several solutions, among them is the development of composite materials where dendrites from a solid solution act as crack stoppers of fissures that are spread by an amorphous matrix. This work presents the results of studies with two types of synthesized materials using the rapid cooling technique from injection copper mold casting at air temperature: 1) a massive amorphous metallic alloy with composition (Fe 0.375 Co 0 .375 B 0.2 Si 0.05 )96Nb 4 (at.%) and 2) a composite of solid solution dendrites α-(FeCo) scattered in an amorphous matrix with a composition similar to alloy 1. Using the samples obtained structural studies were made (optic and electronic microscopy SEM, XRD, EDAX, DTA), magnetic studies (coercive field and saturation magnetization) and mechanical studies (Vickers microhardness). The fully amorphous alloy could be obtained with a

  14. Immobilized waste leaching

    International Nuclear Information System (INIS)

    Suarez, A.A.

    1989-01-01

    The main mechanism by which the immobilized radioactive materials can return to biosphere is the leaching due to the intrusion of water into the repositories. Some mathematical models and experiments utilized to evaluate the leaching rates in different immobilization matrices are described. (author) [pt

  15. Preparation of solid-state samples of a transition metal coordination compound for synchrotron radiation photoemission studies

    CERN Document Server

    Crotti, C; Celestino, T; Fontana, S

    2003-01-01

    The aim of this research was to identify a sample preparation method suitable for the study of transition metal complexes by photoemission spectroscopy with synchrotron radiation as the X-ray source, even in the case where the compound is not evaporable. Solid-phase samples of W(CO) sub 4 (dppe) [dppe=1,2-bis(diphenylphosphino)ethane] were prepared according to different methods and their synchrotron radiation XPS spectra measured. The spectra acquired from samples prepared by spin coating show core level peaks only slightly broader than the spectrum recorded from UHV evaporated samples. Moreover, for these samples the reproducibility of the binding energy values is excellent. The dependence of the spin coating technique on parameters such as solvent and solution concentration, spinning speed and support material was studied. The same preparation method also allowed the acquisition of valence band spectra, the main peaks of which were clearly resolved. The results suggest that use of the spin coating techniqu...

  16. Selective solid phase extraction and pre-concentration of heavy metals from seawater by physically and chemically immobilized 4-amino-3-hydroxy-2-(2-chlorobenzene)-azo-1-naphtalene sulfonic acid silica gel

    International Nuclear Information System (INIS)

    Mahmoud, M.E.; Soayed, A.A.; Hafez, O.F.

    2003-01-01

    4-Amino-3-hydroxy-2 - (2-chlorobenzene)-azo-l-naphthalene sulfonic acid (AHCANSA) was used as a chelating modifier to improve the reactivity of the silica gel surface in terms of selective binding and extraction of heavy metal ions. The surface cover-age values were found to be 0.488 and 0.473 mmol g -1 for the newly modified physically adsorbed silica gel phase (I) and chemically immobilized-AHCANSA phase (II), respectively. The modified silica gel phases (I, II) were tested for stability in different acidic buffer solutions (pH 1-6) and found to be highly resistant to hydrolysis and leaching by buffer solutions above pH 2. The application of these two phases as solid extractors for a series of mono-, di-, and tri-valent metal ions from aqueous solutions was also performed with different controlling factors such as the pH value of metal ion solutions and equilibrium shaking time. The mmol g -1 metal capacity values determined by silica gel phases (I, II) were found to confirm high affinity and selectivity characters for binding with heavy metal ions such as Cr 3+ , Ni 2+ , Cu 2+ , Zn 2+ , Cd 2+ and Pb 2+ in a range of 0.250-0.483. The tested alkali and alkaline earth metals, Na + , K + , Mg 2+ and Ca 2+ , were found to exhibit little interaction and binding ability with the modified silica gel phases. The selectivity characters incorporated into the modified silica gel phases were further utilized and applied in solid phase extraction and pre-concentration of trace concentration levels (∼1.0 μg mL -1 and 2.00-2.50 ng mL -1 ) from real seawater samples. The percentage recovery values determined for Cr 3+ , Cu 2+ , Zn 2+ , Cd 2+ and Pb 2+ were found to be in the range of 95.2-98.1 ± 2.0-5.0 %, and the pre-concentration recovery values for the same tested heavy metal ions were found to be in the range of 92.5-97.1 ± 3.0-6.0 % for the two newly modified silica gel phases with a pre-concentration factor of 500. Refs. 25 (author)

  17. Chemical Immobilization Effect on Lithium Polysulfides for Lithium-Sulfur Batteries.

    Science.gov (United States)

    Li, Caixia; Xi, Zhucong; Guo, Dexiang; Chen, Xiangju; Yin, Longwei

    2018-01-01

    Despite great progress in lithium-sulfur batteries (LSBs), great obstacles still exist to achieve high loading content of sulfur and avoid the loss of active materials due to the dissolution of the intermediate polysulfide products in the electrolyte. Relationships between the intrinsic properties of nanostructured hosts and electrochemical performance of LSBs, especially, the chemical interaction effects on immobilizing polysulfides for LSB cathodes, are discussed in this Review. Moreover, the principle of rational microstructure design for LSB cathode materials with strong chemical interaction adsorbent effects on polysulfides, such as metallic compounds, metal particles, organic polymers, and heteroatom-doped carbon, is mainly described. According to the chemical immobilizing mechanism of polysulfide on LSB cathodes, three kinds of chemical immobilizing effects, including the strong chemical affinity between polar host and polar polysulfides, the chemical bonding effect between sulfur and the special function groups/atoms, and the catalytic effect on electrochemical reaction kinetics, are thoroughly reviewed. To improve the electrochemical performance and long cycling life-cycle stability of LSBs, possible solutions and strategies with respect to the rational design of the microstructure of LSB cathodes are comprehensively analyzed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Titanium coordination compounds: from discrete metal complexes to metal–organic frameworks

    KAUST Repository

    Assi, Hala

    2017-05-24

    Owing to their promise in photocatalysis and optoelectronics, titanium based metal–organic frameworks (MOFs) are one of the most appealing classes of MOFs reported to date. Nevertheless, Ti-MOFs are still very scarce because of their challenging synthesis associated with a poor degree of control of their chemistry and crystallization. This review aims at giving an overview of the recent progress in this field focusing on the most relevant existing titanium coordination compounds as well as their promising photoredox properties. Not only Ti-MOFs but also Ti-oxo-clusters will be discussed and particular interest will be dedicated to highlight the different successful synthetic strategies allowing to overcome the still “unpredictable” reactivity of titanium ions, particularly to afford crystalline porous coordination polymers.

  19. Kinetics as a tool to assess the immobilization of soil trace metals by binding phase amendments for in situ remediation purposes

    International Nuclear Information System (INIS)

    Varrault, Gilles; Bermond, Alain

    2011-01-01

    Highlights: → Assessment of the efficiency of soil remediation method by binding phase amendment. → Use of a kinetic fractionation method to assess trace metal mobility in amended soils. → Vernadite amendments are effective for lead and cadmium remediation. → IHA amendments are only effective for copper remediation. → Advantages of kinetic fractionation vs. extraction schemes performed at equilibrium. - Abstract: Many soil remediation techniques consist in decreasing the mobility of trace metals by means of adding trace metal binding phases. For this study, whose aim is to assess the efficiency of soil remediation method by binding phase amendment, a kinetic fractionation method that provides the labile and slowly labile trace metal amounts in soil has been introduced. Manganese oxides (vernadite) and insolubilized humic acids (IHA) have been used as binding phases for the remediation of four heavily polluted soils. Vernadite amendments are effective for lead and cadmium remediation, whereas IHA amendments are only effective for copper remediation. In most cases, the labile metal fractions decrease dramatically in amended soils (up to 50%); on the other hand, the amounts of total extracted metal near the point of thermodynamic equilibrium often show no significant difference between the amended soil and the control soil. These results highlight the utility of kinetic fractionation in assessing the efficiency of soil remediation techniques and, more generally, in evaluating trace metal mobility in soils and its potential advantages compared to extraction schemes performed under equilibrium conditions. In the future, this kinetic method could be considerably simplified so as to consume much less time allowing its routine use.

  20. Solubility of some phenolic compounds in aqueous alkali metal nitrate solutions from (293.15 to 318.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Noubigh, Adel [Laboratoire de Physico-chimie des materiaux, IPEST, BP51, 2070 La MARSA (Tunisia)], E-mail: Adel.anoubigh@ipest.rnu.tn; Cherif, Mourad [IPEIEM, Universite de Tunis-El Manar, BP244. 2096. El Manar II (Tunisia); Provost, Elise [Laboratoire Chimie et procedes, ENSTA, 32 Rue de Boulevard Victor, 75739 Paris, Cedex 15 (France); Abderrabba, Manef [Laboratoire de Physico-chimie des materiaux, IPEST, BP51, 2070 La MARSA (Tunisia)

    2008-11-15

    This paper is continuation of the study concerning the solubility-temperature dependence data for some phenolic compounds (PhC), contained in olive mill wastewater (OMWW), in two nitrate salts (KNO{sub 3} and NaNO{sub 3}) aqueous solutions. The solubilities of PhC were determined in the temperature ranging from (293.15 to 318.15) K. It has been observed that the solubility, in aqueous nitrate solutions, increases with increasing temperature. Results showed that alkali metal nitrate has a salting-out effect on the solubility of PhC. The effect of the anion of the electrolyte on the solubility of PhC is observed by comparing these results with values reported in the previous papers for the effect of LiCl, NaCl and KCl. For each cation, the solubilites of the phenolic compounds are higher with nitrate anion than with chloride anion. Results were interpreted in terms of the salt hydration shells and the ability of the solute to form hydrogen-bond with water. The solubility data were accurately correlated by a semi empirical equation. The standard molar Gibbs free energies of transfer of PhC ({delta}{sub tr}G{sup 0}) from pure water to aqueous solutions of the nitrate salts have been calculated from the solubility data. The decrease in solubility is correlated to the positive {delta}{sub tr}G{sup 0} value which is mainly of enthalpic origin.

  1. Toxicity testing of heavy metals with the Rhizobium-legume symbiosis: high sensitivity to cadmium and arsenic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, H.; Bode-Kirchhoff, A.; Madeheim, A.; Wetzel, A. [Marburg Univ. (Germany). Fachbereich Biologie

    1998-07-01

    We present data that the formation of nodules (nodulation) may serve for ecotoxicological evaluation of heavy metals in different binding states. Tests were performed in petri dishes with alfalfa (lucerne) seedlings inoculated with Rhizobium meliloti. Cultivation took place in growth cabinets with carefully standardized and documented growth conditions. Data from stressed plants was recorded after 14 days of cultivation on contaminated substrate. A dose responsive decrease in nodulation was found after application of cadmium acetate, cadmium iodide, cadmium chloride, sodium salts of arsenate and arsenite, arsenic pentoxide, and lead nitrate, whereas lead acetate showed no effect up to a concentration of 3 {mu}M. The dose response curves were used to calculate EC10, EC50 and EC90 values. EC50 values for cadmium compounds range from 1.5 to 9.5 {mu}M. Testing different arsenic compounds results in EC50 from 2.6 to 20.1 {mu}M. EC50 of lead nitrate is 2.2 {mu}M. The sensitivity, reproducibility and reliability of this test system is discussed compared to established biotests. (orig./MG)

  2. Reduction in health risk induced by semi-volatile organic compounds and metals in a drinking water treatment plant

    International Nuclear Information System (INIS)

    Zhao, F.; Yin, J.; Zhang, X. X.; Chen, Y.; Zhang, Y.; Wu, B.; Li, M.

    2015-01-01

    This study investigated health risk reduction in a drinking water treatment plant of Nanjing City (China) based on chemical detection of 22 semi-volatile organic compounds (SVOCs) and 24 metallic elements in source water and drinking water during 2009–2011. Chemical analysis showed that 15 SVOCs and 9 metals were present in the water. Health risk assessment revealed that hazard quotient of each pollutant and hazard index (HI) of all the detectable pollutants were below 1.00, indicating that the chemicals posed negligible non-carcinogenic risk to local residents. Benzo(a)pyrene may induce carcinogenic risk since its risk index via both oral and dermal exposure exceeded the safety level (1.00E-6), but other SVOCs induced no carcinogenic risk. Total HI of the SVOCs was 1.08E-3 for the source water and 1.56E-3 for the drinking water, suggesting that the used conventional treatment processes (coagulation/sedimentation, sand filtration and chlorine disinfection) cannot effectively reduce the non-carcinogenic risk. The source water had higher carcinogenic risk than the drinking water, but risk index of the drinking water still exceeded 1.00E-6. This study might serve as a basis for health risk assessment of drinking water and also as a benchmark for the authorities to reduce health risk arising from trace-level hazardous pollutants.

  3. Structure and electronic properties of ordered binay thin-film compounds of rare earths with transition metals

    International Nuclear Information System (INIS)

    Schneider, W.

    2004-01-01

    The present thesis deals with preparation of structurally ordered thin-film compounds of the rare-earths Ce and Dy with the transition metals Pd, Rh, and Ni as well as with investigations of their crystalline and electronic structures. Typically 10 nm-thick films were grown in-situ by deposition of the rare-earth metals onto single crystalline transitionmetal substrates or alternatively by codeposition of both constituents onto a W(110) single crystal. In both cases deposition was followed by short-term annealing at temperatures of 400-1000 C to achieve crystalline order. The latter was analyzed by means of low-energy electron-diffraction (LEED) and evaluated on the basis of a simple kinematic theory. The electronic structure was investigated by means of angle-resolved photoemission (ARPES), partially exploiting synchrotron radiation from BESSY. The studies concentrate mainly on the behavior of the valence bands as a function of structure and composition of the thin films, particularly under consideration of surface phenomena. Measured energy dispersions were compared with results of LDA-LCAO calculations performed in the framework of this thesis. Observed shifts of the energy bands by up to 1 eV are attributed in the light of a simple model to incomplete screening of the photoemission final states. (orig.)

  4. Structural and vibrational study of 8-hydroxyquinoline-2-carboxaldehyde isonicotinoyl hydrazone - A potential metal-protein attenuating compound (MPAC) for the treatment of Alzheimer's disease

    Science.gov (United States)

    de Freitas, Leonardo Viana; da Silva, Cecilia C. P.; Ellena, Javier; Costa, Luiz Antônio Sodré; Rey, Nicolás A.

    2013-12-01

    A comprehensive structural and vibrational study of the potential metal-protein attenuating compound 8-hydroxyquinoline-2-carboxaldehyde isonicotinoyl hydrazone is reported. X-ray diffraction data, as well as FT-IR and Raman frequencies, were compared with the respective theoretical values obtained from DFT calculations. Theory agrees well with experiment. In this context, an attempt of total assignment concerning the FT-IR and Raman spectra of the title compound was performed, shedding new light on previous partial assignments published elsewhere.

  5. Use of response surface methodology to evaluate the effect of metal ions (Ca2+, Ni2+, Mn2+, Cu2+) on production of antifungal compounds by Paenibacillus polymyxa.

    Science.gov (United States)

    Raza, Waseem; Hongsheng, Wu; Qirong, Shen

    2010-03-01

    The effects of four metal ions (Ca(2+), Ni(2+), Mn(2+) and Cu(2+)) were evaluated on growth and production of antifungal compounds by Paenibacillus polymyxa SQR-21 and a quadratic predictive model was developed using response surface methodology (RSM). The results revealed, Mn(2+) and Ni(2+) showed most positive synergistic interactive affect on production of antifungal compounds followed by the positive interactive synergistic affect of Cu(2+) and Ni(2+) and then Mn(2+) and Cu(2+). While the interactive effect of Ca(2+) with all other three metals inhibited the production of antifungal compounds. The Mn(2+) (P=0.0384), Ni(2+) (P=0.0004) and Cu(2+) (P=0.0117) significantly affected the production of antifungal compounds while the effect of Ca(2+) (P=0.1851) was less significant. The maximum growth (OD(600)=1.55) was obtained at 500 (0), 125 (0), 100 (-2) and 37.5 (0) microM levels and the maximum size of inhibition zone (31 mm) was measured at 400 (-1), 150 (1), 400 (1) and 25 microM (-1) levels of Ca(2+), Mn(2+), Ni(2+) and Cu(2+), respectively. The RSM model provided an easy and effective way to determine the interactive effect of metal ions on production of antifungal compounds by P. polymyxa SQR-21 so that optimum media recipes can be developed to produce maximum amounts of antifungal compounds under laboratory and commercial fermentation conditions. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  6. Penicillium digitatum immobilized on pumice stone as a new solid phase extractor for preconcentration and/or separation of trace metals in environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Baytak, Sitki [Department of Chemistry, Faculty of Science and Arts, Harran University, 63100 Sanliurfa (Turkey); Kenduezler, Erdal [Department of Primary Education, Faculty of Education, Ahi Evran University, 40100 Kirsehir (Turkey); Tuerker, Ali Rehber [Department of Chemistry, Faculty of Science and Arts, Gazi University, 06500 Ankara (Turkey)], E-mail: aturker@gazi.edu.tr; Goek, Nuray [Department of Environmental Engineering, Faculty of Engineering, Harran University, 63000 Sanliurfa (Turkey)

    2008-05-30

    This study presents a column solid phase extraction procedure based on column biosorption of Cu(II), Zn(II) and Pb(II) ions on Penicillium digitatum immobilized on pumice stone. The analytes were determined by flame atomic absorption spectrometry (FAAS). The optimum conditions such as: pH values, amount of solid phase, elution solution and flow rate of sample solution were evaluated for the quantitative recovery of the analytes. The effect of interfering ions on the recovery of the analytes has also been investigated. The recoveries of copper, zinc and lead under the optimum conditions were found to be 97 {+-} 2, 98 {+-} 2 and 98 {+-} 2%, respectively, at 95% confidence level. For the analytes, 50-fold preconcentration was obtained. The analytical detection limits for Cu(II), Zn(II) and Pb(II) were 1.8, 1.3 and 5.8 ng mL{sup -1}, respectively. The proposed procedure was applied for the determination of copper, zinc and lead in dam water, waste water, spring water, parsley and carrot. The accuracy of the procedure was checked by determining copper, zinc and lead in standard reference tea samples (GBW-07605)

  7. Penicillium digitatum immobilized on pumice stone as a new solid phase extractor for preconcentration and/or separation of trace metals in environmental samples

    International Nuclear Information System (INIS)

    Baytak, Sitki; Kenduezler, Erdal; Tuerker, Ali Rehber; Goek, Nuray

    2008-01-01

    This study presents a column solid phase extraction procedure based on column biosorption of Cu(II), Zn(II) and Pb(II) ions on Penicillium digitatum immobilized on pumice stone. The analytes were determined by flame atomic absorption spectrometry (FAAS). The optimum conditions such as: pH values, amount of solid phase, elution solution and flow rate of sample solution were evaluated for the quantitative recovery of the analytes. The effect of interfering ions on the recovery of the analytes has also been investigated. The recoveries of copper, zinc and lead under the optimum conditions were found to be 97 ± 2, 98 ± 2 and 98 ± 2%, respectively, at 95% confidence level. For the analytes, 50-fold preconcentration was obtained. The analytical detection limits for Cu(II), Zn(II) and Pb(II) were 1.8, 1.3 and 5.8 ng mL -1 , respectively. The proposed procedure was applied for the determination of copper, zinc and lead in dam water, waste water, spring water, parsley and carrot. The accuracy of the procedure was checked by determining copper, zinc and lead in standard reference tea samples (GBW-07605)

  8. Immobilization of Alkali Metal Fluorides via Recrystallization in a Cationic Lamellar Material, [Th(MoO4)(H2O)4Cl]Cl·H2O.

    Science.gov (United States)

    Lin, Jian; Bao, Hongliang; Qie, Meiying; Silver, Mark A; Yue, Zenghui; Li, Xiaoyun; Zhu, Lin; Wang, Xiaomei; Zhang, Linjuan; Wang, Jian-Qiang

    2018-06-05

    Searching for cationic extended materials with a capacity for anion exchange resulted in a unique thorium molybdate chloride (TMC) with the formula of [Th(MoO 4 )(H 2 O) 4 Cl]Cl·H 2 O. The structure of TMC is composed of zigzagging cationic layers [Th(MoO 4 )(H 2 O) 4 Cl] + with Cl - as interlamellar charge-balancing anions. Instead of performing ion exchange, alkali thorium fluorides were formed after soaking TMC in AF (A = Na, K, and Cs) solutions. The mechanism of AF immobilization is elucidated by the combination of SEM-EDS, PXRD, FTIR, and EXAFS spectroscopy. It was observed that four water molecules coordinating with the Th 4+ center in TMC are vulnerable to competition with F - , due to the formation of more favorable Th-F bonds compared to Th-OH 2 . This leads to a single crystal-to-polycrystalline transformation via a pathway of recrystallization to form alkali thorium fluorides.

  9. Metallic behavior and periodical valence ordering in a MMX chain compound, Pt(2)(EtCS(2))(4)I.

    Science.gov (United States)

    Mitsumi, M; Murase, T; Kishida, H; Yoshinari, T; Ozawa, Y; Toriumi, K; Sonoyama, T; Kitagawa, H; Mitani, T

    2001-11-14

    A new one-dimensional (1-D) halogen-bridged mixed-valence diplatinum(II,III) compound, Pt(2)(EtCS(2))(4)I (3), has been successfully synthesized from [Pt(2)(EtCS(2))(4)] (1) and [Pt(2)(EtCS(2))(4)I(2)] (2). These three compounds have been examined using UV-visible-near-IR, IR, polarized Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and X-ray crystal structure analyses (except for 1). Compound 3 was further characterized through electrical transport measurements, determination of the temperature dependence of lattice parameters, X-ray diffuse scattering, and SQUID magnetometry. 3 crystallizes in the monoclinic space group C2/c and exhibits a crystal structure consisting of neutral 1-D chains with a repeating -Pt-Pt-I- unit lying on the crystallographic 2-fold axis parallel to the b axis. The Pt-Pt distance at 293 K is 2.684 (1) A in the dinuclear unit, while the Pt-I distances are essentially equal (2.982 (1) and 2.978 (1) A). 3 shows relatively high electrical conductivity (5-30 S cm(-1)) at room temperature and undergoes a metal-semiconductor transition at T(M-S) = 205 K. The XPS spectrum in the metallic state reveals a Pt(2+) and Pt(3+) mixed-valence state on the time scale of XPS spectroscopy ( approximately 10(-17) s). In accordance with the metal-semiconductor transition, anomalies are observed in the temperature dependence of the crystal structure, lattice parameters, X-ray diffuse scattering, and polarized Raman spectra near T(M-S). In variable-temperature crystal structure analyses, a sudden and drastic increase in the Pt-I distance near the transition temperature is observed. Furthermore, a steep increase in U(22) of iodine atoms in the 1-D chain direction has been observed. The lattice parameters exhibit significant temperature dependence with drastic change in slope at about 205-240 K. This was especially evident in the unit cell parameter b (1-D chain direction) as it was found to lengthen rapidly with increasing temperature. X

  10. Radioactive and stable metal bioaccumulation, crystalline compound and siderophore detection in Clavariadelphus truncatus

    International Nuclear Information System (INIS)

    Gaso, M.I.; Segovia, N.; Morton, O.; Lopez, J.L.; Machuca, A.; Hernandez, E.

    2007-01-01

    137 Cs and 40 K activity concentrations and stable elements have been measured in Clavariadelphus truncatus collected in Mexico. Iron-chelating compounds of siderophore-type was also studied in the species. 137 Cs and 40 K were determined in soil and mushroom samples with HpGe gamma-ray spectrometry. Macro- and micro-elemental concentrations were determined by XRF and ICP-MS. Siderophore detection was obtained with a colorimetric assay and X-ray diffraction analysis was performed using a Siemens D5000 diffractometer. 137 Cs geometric mean concentration in C. truncatus was 26 times higher as compared with other Mexican edible mushroom species, while 40 K showed stability. Soil-C. truncatus concentration ratio for 137 Cs and other micro-elements such as Cs, Rb and Pb were also higher than other Mexican edible species. The 137 Cs committed effective dose due to the ingestion of C. truncatus was 8 x 10 -6 Sv year -1 . The main crystalline structure found in C. truncatus was D-Mannitol

  11. Radioactive and stable metal bioaccumulation, crystalline compound and siderophore detection in Clavariadelphus truncatus

    Energy Technology Data Exchange (ETDEWEB)

    Gaso, M.I. [ININ, Ap. Post. 18-1027, C.P. 11801, Mexico D.F. (Mexico)], E-mail: migp@nuclear.inin.mx; Segovia, N. [Instituto de Geofisica, UNAM, Ciudad Universitaria, 04510 Mexico, D.F. (Mexico)], E-mail: nurina@terra.com.mx; Morton, O. [Instituto de Geofisica, UNAM, Ciudad Universitaria, 04510 Mexico, D.F. (Mexico)], E-mail: omorton@geofisica.unam.mx; Lopez, J.L. [Instituto de Geografia, UNAM, Ciudad Universitaria, 04510 Mexico, D.F. (Mexico)], E-mail: jlc@servidor.unam.mx; Machuca, A. [Departmento Forestal, Universidad de Concepcion, Los Angeles (Chile)], E-mail: angmachu@udec.cl; Hernandez, E. [Instituto de Geofisica, UNAM, Ciudad Universitaria, 04510 Mexico, D.F. (Mexico)], E-mail: aeliza@geofisica.unam.mx

    2007-09-15

    {sup 137}Cs and {sup 40}K activity concentrations and stable elements have been measured in Clavariadelphus truncatus collected in Mexico. Iron-chelating compounds of siderophore-type was also studied in the species. {sup 137}Cs and {sup 40}K were determined in soil and mushroom samples with HpGe gamma-ray spectrometry. Macro- and micro-elemental concentrations were determined by XRF and ICP-MS. Siderophore detection was obtained with a colorimetric assay and X-ray diffraction analysis was performed using a Siemens D5000 diffractometer. {sup 137}Cs geometric mean concentration in C. truncatus was 26 times higher as compared with other Mexican edible mushroom species, while {sup 40}K showed stability. Soil-C. truncatus concentration ratio for {sup 137}Cs and other micro-elements such as Cs, Rb and Pb were also higher than other Mexican edible species. The {sup 137}Cs committed effective dose due to the ingestion of C. truncatus was 8 x 10{sup -6} Sv year{sup -1}. The main crystalline structure found in C. truncatus was D-Mannitol.

  12. Thermal, structural, and magnetic studies of metals and intermetallic compounds. Final report

    International Nuclear Information System (INIS)

    Wallace, W.E.; Craig, R.S.; Rao, V.U.S.

    1976-01-01

    The powerful magnetism of certain intermetallics, e.g., SmCo 5 , has been established to originate with the powerful magnetic anisotropy of SmCo 5 , not its large magnetization. The anisotropy is, in turn, a crystal field effect. The crystal field interaction has been elucidated by the method of quantum mechanics. Studies of the systems RFe 2 , RFe 3 , RCo 3 , and R 2 Co 7 (R = a rare earth, Y or Th) reveals them to be important for hydrogen storage. In addition, important effects associated with hydrogenation of metals have been found--great enhancement of magnetization of certain systems (e.g., ErFe 2 ) and substantial increase in superconducting transition temperatures (e.g., Zr/sub .5/H/sub .5/V 2 ). Results of studies suggest that the surfaces of rare earth intermetallics are atypical. The spectrum of properties exhibited by the rare earth intermetallics suggests their utility in the efficient capture and storage of solar energy and the use of it for powering a vehicle. These aspects of the systems warrant further attention

  13. Hypervalent Compounds as Ligands: I 3 -Anion Adducts with Transition Metal Pentacarbonyls

    KAUST Repository

    Rogachev, Andrey Yu.

    2013-06-17

    Just a couple of transition metal complexes of the familiar triiodide anion are known. To investigate the bonding in these, as well as isomeric possibilities, we examined theoretically adducts of I3 - with model organometallic fragments, [Cr(CO)5] and [Mn(CO) 5]+. Bonding energy computations were augmented by a Natural Bond Orbital (NBO) perturbation theory analysis and Energy Decomposition Analysis (EDA). The bonding between I3 - and the organometallic fragment is substantial, especially for the electrostatically driven anion-cation case. "End-on" coordination is favored by 5-13 kcal/mol over "side-on" (to the central I of I3 -), with a ∼10 kcal/mol barrier for isomerization. A developing asymmetry in the I-I bonding of "end-on" coordinated I 3 - led us to consider in some detail the obvious fragmentation to a coordinated I- and free I2. While the signs of incipient fragmentation in that direction are there, these is a definite advantage to maintaining some I- to I2 bonding in triiodide complexes. © 2013 American Chemical Society.

  14. Plutonium Disposition by Immobilization

    International Nuclear Information System (INIS)

    Gould, T.; DiSabatino, A.; Mitchell, M.

    2000-01-01

    The ultimate goal of the Department of Energy (DOE) Immobilization Project is to develop, construct, and operate facilities that will immobilize between 17 to 50 tonnes (MT) of U.S. surplus weapons-usable plutonium materials in waste forms that meet the ''spent fuel'' standard and are acceptable for disposal in a geologic repository. Using the ceramic can-in-canister technology selected for immobilization, surplus plutonium materials will be chemically combined into ceramic forms which will be encapsulated within large canisters of high level waste (HLW) glass. Deployment of the immobilization capability should occur by 2008 and be completed within 10 years. In support of this goal, the DOE Office of Fissile Materials Disposition (MD) is conducting development and testing (D and T) activities at four DOE laboratories under the technical leadership of Lawrence Livermore National Laboratory (LLNL). The Savannah River Site has been selected as the site for the planned Plutonium Immobilization Plant (PIP). The D and T effort, now in its third year, will establish the technical bases for the design, construction, and operation of the U. S. capability to immobilize surplus plutonium in a suitable and cost-effective manner. Based on the D and T effort and on the development of a conceptual design of the PIP, automation is expected to play a key role in the design and operation of the Immobilization Plant. Automation and remote handling are needed to achieve required dose reduction and to enhance operational efficiency

  15. Theoretical Modelling of Immobilization of Cadmium and Nickel in Soil Using Iron Nanoparticles

    Directory of Open Access Journals (Sweden)

    Vaidotas Danila

    2017-09-01

    Full Text Available Immobilization using zero valent using iron nanoparticles is a soil remediation technology that reduces concentrations of dissolved contaminants in soil solution. Immobilization of heavy metals in soil can be achieved through heavy metals adsorption and surface complexation reactions. These processes result in adsorption of heavy metals from solution phase and thus reducing their mobility in soil. Theoretical modelling of heavy metals, namely, cadmium and nickel, adsorption using zero valent iron nanoparticles was conducted using Visual MINTEQ. Adsorption of cadmium and nickel from soil solutions were modelled separately and when these metals were dissolved together. Results have showed that iron nanoparticles can be successfully applied as an effective adsorbent for cadmium and nickel removal from soil solution by producing insoluble compounds. After conducting the modelling of dependences of Cd+2 and Ni+2 ions adsorption on soil solution pH using iron nanoparticles, it was found that increasing pH of solution results in the increase of these ions adsorption. Adsorption of cadmium reached approximately 100% when pH ≥ 8.0, and adsorption of nickel reached approximately 100% when pH ≥ 7.0. During the modelling, it was found that adsorption of heavy metals Cd and Ni mostly occur, when one heavy metal ion is chemically adsorbed on two sorption sites. During the adsorption modelling, when Cd+2 and Ni+2 ions were dissolved together in acidic phase, it was found that adsorption is slightly lower than modelling adsorption of these metals separately. It was influenced by the competition of Cd+2 and Ni+2 ions for sorption sites on the surface of iron nanoparticles.

  16. Extracellular polymeric substances from copper-tolerance Sinorhizobium meliloti immobilize Cu{sup 2+}

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Wenjie; Ma, Zhanqiang; Sun, Liangliang; Han, Mengsha; Lu, Jianjun; Li, Zhenxiu; Mohamad, Osama Abdalla; Wei, Gehong, E-mail: weigehong@nwsuaf.edu.cn

    2013-10-15

    Highlights: • EPS produced by Sinorhizobium meliloti CCNWSX0020 restricts uptake of Cu{sup 2+}. • We focused on the EPS, which is divided into three main parts. • LB-EPS played a more important role than S-EPS and TB-EPS in Cu{sup 2+} immobilization. • Proteins and carbohydrates were the main extracellular compounds which had functional groups such as carboxyl (-COOH), hydroxyl (-OH), and amide (N-H), primarily involved in metal ion binding. -- Abstract: The copper tolerance gene of wild-type heavy metal-tolerance Sinorhizobium meliloti CCNWSX0020 was mutated by transposon Tn5-a. The mutant was sensitive up to 1.4 mM Cu{sup 2+}. Production, components, surface morphology, and functional groups of extracellular polymeric substances (EPS) of the wild-type strains were compared with sensitive mutant in immobilization of Cu{sup 2+}. EPS produced by S. meliloti CCNWSX0020 restricts uptake of Cu{sup 2+}. The cell wall EPS were categorized based on the compactness and fastness: soluble EPS (S-EPS), loosely bound EPS (LB-EPS), and tightly bound EPS (TB-EPS). LB-EPS played a more important role than S-EPS and TB-EPS in Cu{sup 2+} immobilization. Scanning electron microscopy (SEM) analysis LB-EPS had rough surface and many honeycomb pores, making them conducive to copper entry; therefore, they may play a role as a microbial protective barrier. Fourier transform-infrared (FT-IR) analysis further confirm that proteins and carbohydrates were the main extracellular compounds which had functional groups such as carboxyl (-COOH), hydroxyl (-OH), and amide (N-H), primarily involved in metal ion binding.

  17. [Impact of compounded chelants on removal of heavy metals and characteristics of morphologic change in soil from heavy metals contaminated sites].

    Science.gov (United States)

    Yin, Xue; Chen, Jia-Jun; Lü, Ce

    2014-02-01

    Na2 EDTA (EDTA) has been extensively applied in remediation of soil contaminated by heavy metals (HMs). However, it poses a threat to the environment due to its difficulty of degradation. In addition, it is of great importance to clarify the morphological distribution of these metals in soil, as it is related to the environmental risk of contaminated sites. Thus, in order to cut back the use of EDTA, a series of batch washing experiments were conducted to evaluate the removal of arsenic, cadmium, copper, and lead from the contaminated soil collected in a chemical plant. Furthermore, adopting the optimal ratio of EDTA/EDDS, the change of morphological distribution of HMs before and after washing was studied. The results indicated that the removal of arsenic, cadmium and lead reached the maximum when the ratio of EDTA/EDDS was 7:3 and the optimal value was 12.67%, 38.71% and 31.09%, respectively. The removal of copper reached 16.91% at an EDTA/EDDS ratio of 9:1. After washing, the absolute Fe-Mn oxide fraction concentration of arsenic was higher, which would increase the environmental risk; the morphological fraction distribution of cadmium was similar to the original soil; the removal of copper and lead was mainly derived from the Fe-Mn oxide fraction; as to lead, the absolute concentration of Fe-Mn oxide fraction decreased dramatically, was and the same was observed for the percentage in the organic fraction. Employing the compounded system, the removal of HMs could be improved, and meanwhile the amounts of bioavailable HMs declined. Hence, it is beneficial for providing theoretical support for HMs remediation.

  18. Genotoxicity of two heavy metal compounds: lead nitrate and cobalt chloride in Polychaete Perinereis cultrifera.

    Science.gov (United States)

    Singh, Nisha; Bhagat, Jacky; Ingole, Baban S

    2017-07-01

    The present study explores the in vivo and in vitro genotoxic effects of lead nitrate, [Pb(NO 3 ) 2 ] a recognized environmental pollutant and cobalt chloride (CoCl 2 ), an emerging environmental pollutant in polychaete Perinereis cultrifera using comet assay. Despite widespread occurrence and extensive industrial applications, no previous published reports on genotoxicity of these compounds are available in polychaete as detected by comet assay. Polychaetes were exposed in vivo to Pb(NO 3 ) 2 (0, 100, 500, and 1000 μg/l) and CoCl 2 (0, 100, 300, and 500 μg/l) for 5 days. At 100 μg/l Pb(NO 3 ) 2 concentration, tail DNA (TDNA) values in coelomocytes were increase by 1.16, 1.43, and 1.55-fold after day 1, day 3, and day 5, whereas, OTM showed 1.12, 2.33, and 2.10-fold increase in in vivo. Pb(NO 3 ) 2 showed a concentration and time-dependent genotoxicity whereas CoCl 2 showed a concentration-dependent genotoxicity in in vivo. A concentration-dependent increase in DNA damage was observed in in vitro studies for Pb(NO 3 ) 2 and CoCl 2 . DNA damage at 500 μg/L showed almost threefold increase in TDNA and approximately fourfold increase in OTM as compared to control in in vitro. Our studies suggest that Pb(NO 3 ) 2 and CoCl 2 have potential to cause genotoxic damage, with Pb(NO 3 ) 2 being more genotoxic in polychaete and should be used more carefully in industrial and other activities. Graphical abstract.

  19. Metals, organic compounds, and nutrients in Long Island Sound: sources, magnitudes, trends, and impacts

    Science.gov (United States)

    Mullaney, John R.; Varekamp, J.C.; MCElroy, A.E.; Brsslin, V.T.

    2014-01-01

    Long Island Sound (LIS) is a relatively shallow estuary with a mean depth of 20 m (maximum depth 49 m) and a unique hydrology and history of pollutant loading. Those factors have contributed to a wide variety of contamination problems in its muddy sediments, aquatic life and water column. The LIS sediments are contaminated with a host of legacy and more recently released toxic compounds and elements related to past and present wastewater discharges and runoff. These include non-point and storm water runoff and groundwater discharges, whose character has changed over the years along with the evolution of its watershed and industrial history. Major impacts have resulted from the copious amounts of nutrients discharged into LIS through atmospheric deposition (N), domestic and industrial waste water flows, fertilizer releases, and urban runoff. All these sources and their effects are in essence the result of human presence and activities in the watershed, and the severity of pollutant loading and their impacts generally scales with total population in the watersheds surrounding LIS. Environmental legislation passed since the mid-to late 1900s (e.g., Clean Air Act, Clean Water Act) has had a beneficial effect, however, and contaminant loadings for many toxic organic and inorganic chemicals and nutrients have diminished over the last few decades (O’Shea and Brosnan 2000; Trench, et al, 2012; O’Connor and Lauenstein 2006; USEPA 2007). Major strides have been made in reducing the inflow of nutrients into LIS, but cultural eutrophication is still an ongoing problem and nutrient control efforts will need to continue. Nonetheless, LIS is still a heavily human impacted estuary (an ‘Urban Estuary’, as described for San Francisco Bay by Conomos, 1979), and severe changes in water quality and sediment toxicity as well as ecosystem shifts have been witnessed over the relatively short period since European colonization in the early 1600s (Koppelman et al., 1976).

  20. Proton and metal ion binding to natural organic polyelectrolytes-I. Studies with synthetic model compounds

    Science.gov (United States)

    Marinsky, J.A.; Reddy, M.M.

    1984-01-01

    A unified physico-chemical model, based on a modified Henderson-Hasselbalch equation, for the analysis of ion complexation reactions involving charged polymeric systems is presented and verified. In this model pH = pKa+p(??Ka) + log(??/1 - ??) where Ka is the intrinsic acid dissociation constant of the ionizable functional groups on the polymer, ??Ka is the deviation of the intrinsic constant due to electrostatic interaction between the hydrogen ion and the polyanion, and alpha (??) is the polyacid degree of ionization. Using this approach pKa values for repeating acidic units of polyacrylic (PAA) and polymethacrylic (PMA) acids were found to be 4.25 ?? 0.03 and 4.8 ?? 0.1, respectively. The polyion electrostatic deviation term derived from the potentiometric titration data (i.e. p(??Ka)) is used to calculate metal ion concentration at the complexation site on the surface of the polyanion. Intrinsic cobalt-polycarboxylate binding constants (7.5 for PAA and 5.6 for PMA), obtained using this procedure, are consistent with the range of published binding constants for cobalt-monomer carboxylate complexes. In two phase systems incorporation of a Donnan membrane potential term allows determination of the intrinsic pKa of a cross-linked PMA gel, pKa = 4.83, in excellent agreement with the value obtained for the linear polyelectrolyte and the monomer. Similarly, the intrinsic stability constant for cobalt ion binding to a PMA-gel (??CoPMA+ = 11) was found to be in agreement with the linear polyelectrolyte analogue and the published data for cobalt-carboxylate monodentate complexes. ?? 1984.

  1. Oak Ridge Integrated Field-Scale Research Challenge ERKP686: Multi-scale Investigations on the Rates and Mechanisms of Targeted Immobilization and Natural Attenuation of Metal, Radionuclide and Co-Contaminants in the Subsurface (project overview)

    International Nuclear Information System (INIS)

    Phil Jardine; Dave Watson; Susan Hubbard; Ken Williams; J. Chen

    2007-01-01

    and dilution of contaminants along flow pathways and determine how they change temporally and spatially during episodic events, seasonally, and long term. (2) determine the rates and mechanisms of coupled hydrological, geochemical, and microbiological processes that control the natural attenuation of contaminants in highly diverse subsurface environments over scales ranging from molecular to watersheds. (3) explore novel strategies for enhancing the subsurface stability of immobilized metals and radionuclides. (4) understand the long-term impacts of geochemical and hydrologic heterogeneity on the remobilization of immobilized radionuclides. (5) improve our ability to predict the long-term effectiveness of remedial activities and natural attenuation processes that control subsurface contaminant behavior across a variety of scales

  2. Selected Trace Metals and Organic Compounds and Bioavailability of Selected Organic Compounds in Soils, Hackberry Flat, Tillman County, Oklahoma, 1994-95

    National Research Council Canada - National Science Library

    Becker, Mark F

    1997-01-01

    .... S. Geological Survey, in cooperation with Wildlife Conservation and the Oklahoma Geological Survey, examined the soils of Hackberry Flat to determine trace metal concentrations, presence of selected...

  3. Biosensor for metal analysis and speciation

    Science.gov (United States)

    Aiken, Abigail M.; Peyton, Brent M.; Apel, William A.; Petersen, James N.

    2007-01-30

    A biosensor for metal analysis and speciation is disclosed. The biosensor comprises an electron carrier immobilized to a surface of an electrode and a layer of an immobilized enzyme adjacent to the electrode. The immobilized enzyme comprises an enzyme having biological activity inhibited by a metal to be detected by the biosensor.

  4. In situ immobilization of cadmium and zinc in contaminated soils : fiction or fixation?

    NARCIS (Netherlands)

    Osté, L.

    2001-01-01

    Keywords: beringite, cadmium, DOC, DOM, earthworms, immobilization, leaching, lime, manganese oxides, metal binding, metal uptake, organic matter partitioning, pH, soil contamination, remediation, sorption, Swiss chard, zeolites, zinc.

    It is generally

  5. First-principles study of half-metallic properties in RbCaNZ (Z = O, S, and Se) quaternary Heusler compounds

    Science.gov (United States)

    Rezaei, S.; Ahmadian, F.

    2018-06-01

    On the basis of first principles calculations, the electronic structures and magnetic properties of quaternary Heusler alloys RbCaNZ (Z = O, S, and Se) were studied. The negative formation energies indicated that all these compounds were thermodynamically stable and thus may be experimentally synthesized at appropriate conditions in the future. The results showed that YI structure was the most favorable configuration among the three possible structures. All compounds were found to be half-metallic ferromagnets. The characteristic of energy bands and origin of half-metallicity were also verified. The total magnetic moments of RbCaNZ (Z = O, S, and Se) compounds were obtained 2μB per formula unit, which were in an agreement with Slater-Pauling rule (Mtot = 12 - Ztot). Half-metallicity was preserved at ranges of 5.06-8.36 Å, 5.96-8.81 Å, and 6.13-8.73 Å for RbCaNO, RbCaNS, and RbCaNSe compounds, respectively, which show that these quaternary Heusler compounds may be potential candidates in spintronic applications.

  6. Enzyme Immobilization: An Overview on Methods, Support Material, and Applications of Immobilized Enzymes.

    Science.gov (United States)

    Sirisha, V L; Jain, Ankita; Jain, Amita

    Immobilized enzymes can be used in a wide range of processes. In recent years, a variety of new approaches have emerged for the immobilization of enzymes that have greater efficiency and wider usage. During the course of the last two decades, this area has rapidly expanded into a multidisciplinary field. This current study is a comprehensive review of a variety of literature produced on the different enzymes that have been immobilized on various supporting materials. These immobilized enzymes have a wide range of applications. These include applications in the sugar, fish, and wine industries, where they are used for removing organic compounds from waste water. This study also reviews their use in sophisticated biosensors for metabolite control and in situ measurements of environmental pollutants. Immobilized enzymes also find significant application in drug metabolism, biodiesel and antibiotic production, bioremediation, and the food industry. The widespread usage of immobilized enzymes is largely due to the fact that they are cheaper, environment friendly, and much easier to use when compared to equivalent technologies. © 2016 Elsevier Inc. All rights reserved.

  7. Studies on the preparation of immobilized enzymes by radiopolymerization, (9)

    International Nuclear Information System (INIS)

    Kawashima, Koji; Fujino, Satomi; Hayashi, Toru; Kim, Sung-K.

    1982-01-01

    Glucose Oxidase (GOD, EC 1, 1, 3, 4) was immobilized in the form of the beads by the radiation polymerization method under low temperature and the enzymatic characteristics were investigated. 1) Polyethyleneglycol dimethacrylate and acrylamide were favorable compounds for the immobilization of GOD. 2) Neither optimum pH nor pH stability was changed after immobilization treatment. 3) Optimum reaction temperature was shifted by 5 0 C to the higher side and heat stability was improved. 4) Immobilized GOD showed activity up to 60U per gram of dried polymer. 5) The small beads had retained high activities (10 - 80%) 6) The immobilized GOD was not leached out from the polymer matrix. (author)

  8. 3D Online Submicron Scale Observation of Mixed Metal Powder's Microstructure Evolution in High Temperature and Microwave Compound Fields

    Directory of Open Access Journals (Sweden)

    Dan Kang

    2014-01-01

    Full Text Available In order to study the influence on the mechanical properties caused by microstructure evolution of metal powder in extreme environment, 3D real-time observation of the microstructure evolution of Al-Ti mixed powder in high temperature and microwave compound fields was realized by using synchrotron radiation computerized topography (SR-CT technique; the spatial resolution was enhanced to 0.37 μm/pixel through the designed equipment and the introduction of excellent reconstruction method for the first time. The process of microstructure evolution during sintering was clearly distinguished from 2D and 3D reconstructed images. Typical sintering parameters such as sintering neck size, porosity, and particle size of the sample were presented for quantitative analysis of the influence on the mechanical properties and the sintering kinetics during microwave sintering. The neck size-time curve was obtained and the neck growth exponent was 7.3, which indicated that surface diffusion was the main diffusion mechanism; the reason was the eddy current loss induced by the external microwave fields providing an additional driving force for mass diffusion on the particle surface. From the reconstructed images and the curve of porosity and average particle size versus temperature, it was believed that the presence of liquid phase aluminum accelerated the densification and particle growth.

  9. Treatment of heavy metal contaminated soils by in situ vitrification

    International Nuclear Information System (INIS)

    Hansen, J.E.

    1991-01-01

    Contaminated soil site remediation objectives call for the destruction, removal, and/or immobilization of contaminant species. Destruction is applicable to hazardous compounds (e.g., hazardous organics such as PCBs; hazardous inorganics such as cyanide); however, it is not applicable to hazardous elements such as the heavy metals. Removal and/or immobilization are typical objectives for heavy metal contaminants present in soil. Many technologies have been developed specifically to meet these needs. One such technology is In Situ Vitrification (ISV), an innovative mobile, onsite, in situ solids remediation technology that has been available on a commercial basis for about two years. ISV holds potential for the safe and permanent treatment/remediation of previously disposed or current process solids waste (e.g., soil, sludge, sediment, tailings) contaminated with hazardous chemical and/or radioactive materials. This paper focuses on the application of ISV to heavy metal-contaminated soils

  10. Uranium speciation and stability after reductive immobilization in sediments.

    OpenAIRE

    Sharp J.O

    2011-01-01

    It has generally been assumed that the bioreduction of hexavalent uranium in groundwater systems will result in the precipitation of immobile uraninite (UO2). In order to explore the form and stability of uranium immobilized under these conditions we introduced lactate (15 mM for 3 months) into flow through columns containing sediments derived from a former uranium processing site at Old Rifle CO. This resulted in metal reducing conditions as evidenced by concurrent uranium uptake and iron re...

  11. Uranium speciation and stability after reductive immobilization in sediments

    OpenAIRE

    Sharp, Jonathan O.; Schofield, Eleanor J.; Lezama-Pacheco, Juan S.; Webb, Sam; Ulrich, Kai-Uwe; Blue, Lisa; Chinni, Satyavani; Veeramani, Harish; Junier, Pilar; Margot-Roquier, Camille; Suvorova Buffat, Elena; Tebo, Bradley M.; Giammar, Daniel E.; Bargar, John R.; Bernier-Latmani, Rizlan

    2011-01-01

    It has generally been assumed that the bioreduction of hexavalent uranium in groundwater systems will result in the precipitation of immobile uraninite (UO2). In order to explore the form and stability of uranium immobilized under these conditions, we introduced lactate (15 mM for 3 months) into flow-through columns containing sediments derived from a former uranium-processing site at Old Rifle, CO. This resulted in metal-reducing conditions as evidenced by concurrent uranium uptake and iron ...

  12. Immobilization of Fe chelators on sepharose gel and its effect on their chemical properties.

    Science.gov (United States)

    Yehuda, Zehava; Hadar, Yitzhak; Chen, Yona

    2003-09-24

    Iron chelates are usually costly and easily leached beyond the root zone. This creates a need to frequently replenish the rhizosphere with chelated Fe and might contaminate groundwater with organic compounds and metals. The development of a slow-release Fe fertilizer that will efficiently supply Fe to plants while exhibiting high resistance toward leaching and/or degradation in the rhizosphere has been the focus of this study. Desferrioxamine B (DFOB) and ethylenediaminebis(o-hydroxyphenylacetic acid) (EDDHA) were immobilized on Sepharose. (13)C NMR and FTIR measurements confirmed that coupling of DFOB to the gel did not appear to influence its ability to chelate Fe(3+) or its binding nature. Isotherms for the immobilized ligands were determined in the presence of 1 mM HEDTA, at 25 degrees C and at an ionic strength of 0.1 M. The isotherms showed a high affinity of Fe(3+) to the ligands and binding up to saturation level throughout the pH range examined (4.0-9.0). The K(app) values for the immobilized Fe chelates were determined using a modified Scatchard model and found to be lower than the soluble ones. This decrease in K(app) might facilitate Fe uptake from these chelates by plants.

  13. In vitro and in vivo studies of lead immobilization by synthetic hydroxyapatite

    International Nuclear Information System (INIS)

    Arnich, Nathalie; Lanhers, Marie-Claire; Laurensot, Franck; Podor, Renaud; Montiel, Antoine; Burnel, Daniel

    2003-01-01

    Lead immobilization by solid hydroxyapatite significantly reduces lead concentration and bioavailability in water. - Apatite appears a useful compound for removing lead from water, due to its ability to immobilize the metal by precipitation. In dilute solution, dissolved hydroxyapatite [HA, Ca 10 (PO 4 ) 6 (OH) 2 ] provided phosphates that were reactive with aqueous lead (molar ratio HA/Pb=1/10) forming precipitates at around pH 6. These dissolved at a more acidic pH (3). Solid HA in contact with Pb 2+ ions, led to the formation of pyromorphite [Pb 10 (PO 4 ) 6 (OH) 2 ], identified by X-ray diffraction and insoluble at pH tested (3-8). The amount of pyromorphite increased with the weight ratio of HA/Pb. When this one increased from 1 to 1000, lead precipitated as pyromorphite rose from 19 to 99%. In vivo experiments on rats confirmed the in vitro results. In fact, lead bioavailability assessed by intestinal perfusion was unchanged in the presence of dissolved HA, whereas it was significantly lower in the presence of solid HA, evaluated by gastric intubation, at a weight ratio equal to 10 (amount of lead absorbed decreased by 60%). Apatite could be an effective means of immobilizing lead in drinking or sewage, since accidental pyromorphite ingestion does not yield bioavailable lead

  14. Ceramification: A plutonium immobilization process

    Energy Technology Data Exchange (ETDEWEB)

    Rask, W.C. [Dept. of Energy, Golden, CO (United States); Phillips, A.G. [Rocky Flats Environmental Technology Site, Golden, CO (United States)

    1996-05-01

    This paper describes a low temperature technique for stabilizing and immobilizing actinide compounds using a combination process/storage vessel of stainless steel, in which measured amounts of actinide nitrate solutions and actinide oxides (and/or residues) are systematically treated to yield a solid article. The chemical ceramic process is based on a coating technology that produces rare earth oxide coatings for defense applications involving plutonium. The final product of this application is a solid, coherent actinide oxide with process-generated encapsulation that has long-term environmental stability. Actinide compounds can be stabilized as pure materials for ease of re-use or as intimate mixtures with additives such as rare earth oxides to increase their degree of proliferation resistance. Starting materials for the process can include nitrate solutions, powders, aggregates, sludges, incinerator ashes, and others. Agents such as cerium oxide or zirconium oxide may be added as powders or precursors to enhance the properties of the resulting solid product. Additives may be included to produce a final product suitable for use in nuclear fuel pellet production. The process is simple and reduces the time and expense for stabilizing plutonium compounds. It requires a very low equipment expenditure and can be readily implemented into existing gloveboxes. The process is easily conducted with less associated risk than proposed alternative technologies.

  15. gem-Difluoroolefination of Diazo Compounds with TMSCF3 or TMSCF2Br: Transition-Metal-Free Cross-Coupling of Two Carbene Precursors.

    Science.gov (United States)

    Hu, Mingyou; Ni, Chuanfa; Li, Lingchun; Han, Yongxin; Hu, Jinbo

    2015-11-18

    A new olefination protocol for transition-metal-free cross-coupling of two carbene fragments arising from two different sources, namely, a nonfluorinated carbene fragment resulting from a diazo compound and a difluorocarbene fragment derived from Ruppert-Prakash reagent (TMSCF3) or TMSCF2Br, has been developed. This gem-difluoroolefination proceeds through the direct nucleophilic addition of diazo compounds to difluorocarbene followed by elimination of N2. Compared to previously reported Cu-catalyzed gem-difluoroolefination of diazo compounds with TMSCF3, which possesses a narrow substrate scope due to a demanding requirement on the reactivity of diazo compounds and in-situ-generated CuCF3, this transition-metal-free protocol affords a general and efficient approach to various disubstituted 1,1-difluoroalkenes, including difluoroacrylates, diaryldifluoroolefins, as well as arylalkyldifluoroolefins. In view of the ready availability of diazo compounds and difluorocarbene reagents and versatile transformations of 1,1-difluoroalkenes, this new gem-difluoroolefination method is expected to find wide applications in organic synthesis.

  16. Syntheses, structural variants and characterization of AInM′S4 (A=alkali metals, Tl; M′ = Ge, Sn) compounds; facile ion-exchange reactions of layered NaInSnS4 and KInSnS4 compounds

    International Nuclear Information System (INIS)

    Yohannan, Jinu P.; Vidyasagar, Kanamaluru

    2016-01-01

    Ten AInM′S 4 (A=alkali metals, Tl; M′= Ge, Sn) compounds with diverse structure types have been synthesized and characterized by single crystal and powder X-ray diffraction and a variety of spectroscopic methods. They are wide band gap semiconductors. KInGeS 4 (1-β), RbInGeS 4 (2), CsInGeS 4 (3-β), TlInGeS 4 (4-β), RbInSnS 4 (8-β) and CsInSnS 4 (9) compounds with three-dimensional BaGa 2 S 4 structure and CsInGeS 4 (3-α) and TlInGeS 4 (4-α) compounds with a layered TlInSiS 4 structure have tetrahedral [InM′S 4 ] − frameworks. On the other hand, LiInSnS 4 (5) with spinel structure and NaInSnS 4 (6), KInSnS 4 (7), RbInSnS 4 (8-α) and TlInSnS 4 (10) compounds with layered structure have octahedral [InM′S 4 ] − frameworks. NaInSnS 4 (6) and KInSnS 4 (7) compounds undergo facile topotactic ion-exchange, at room temperature, with various mono-, di- and tri-valent cations in aqueous medium to give rise to metastable layered phases. - Graphical abstract: NaInSnS 4 and KInSnS 4 compounds undergo, in aqueous medium at room temperature, facile topotactic ion-exchange with mono, di and trivalent cations. Display Omitted - Highlights: • Ten AInM′S 4 compounds with diverse structure types were synthesized. • They are wide band gap semiconductors. • NaInSnS 4 and KInSnS 4 compounds undergo facile topotactic ion-exchange at room temperature.

  17. Site specific X-ray induced changes in organic and metal organic compounds and their influence on global radiation damage

    International Nuclear Information System (INIS)

    Heintz, Desiree Ellen

    2012-07-01

    The aim of this work was to systematically investigate the effects of specific and global X-ray radiation damage to biological samples and obtain a conclusive model to describe the underlying principles. Based on the systematic studies performed in this work, it was possible to propose two conclusive mechanisms to describe X-ray induced photoreduction and global radiation damage. The influence of chemical composition, temperature and solvent on X-ray induced photoreduction was investigated by X-ray Absorption Near Edge Spectroscopy and single crystal X-ray diffraction of two B12 cofactors - cyano- and methylcobalamin - as well as iron(II) and iron(III) complexes. The obtained results revealed that X-ray induced photoreduction is a ligand dependent process, with a redox reaction taking place within the complex. It could further be shown that selective hydrogen abstraction plays an important role in the process of X-ray induced photoreduction. Based on the experimental results of this work, a model to describe X-ray induced photoreduction of metal organic complexes could be proposed. The process of X-ray induced hydrogen abstraction was further investigated in a combined X-ray and neutron diffraction study on the amino acids L-serine and L-alanine, which were used as model compounds for proteins, and the nucleoside deoxythymidine (thymidine) as a model for DNA. A damage mechanism for L-serine could be found. It involves the abstraction of two hydrogen atoms, one from the hydroxyl group and one from the adjacent methylene group. Such a hydrogen abstraction results in the formation of a carbonyl group. X-ray diffraction measurements on cyano- and methylcobalamin as well as on three metal amino acid complexes, containing nickel(II) and copper(II), respectively, were conducted to investigate the contribution of X-ray induced photoreduction to global radiation damage. Results from these measurements combined with the results from L-serine, L-alanine and thymidine allowed

  18. Site specific X-ray induced changes in organic and metal organic compounds and their influence on global radiation damage

    Energy Technology Data Exchange (ETDEWEB)

    Heintz, Desiree Ellen

    2012-07-15

    The aim of this work was to systematically investigate the effects of specific and global X-ray radiation damage to biological samples and obtain a conclusive model to describe the underlying principles. Based on the systematic studies performed in this work, it was possible to propose two conclusive mechanisms to describe X-ray induced photoreduction and global radiation damage. The influence of chemical composition, temperature and solvent on X-ray induced photoreduction was investigated by X-ray Absorption Near Edge Spectroscopy and single crystal X-ray diffraction of two B12 cofactors - cyano- and methylcobalamin - as well as iron(II) and iron(III) complexes. The obtained results revealed that X-ray induced photoreduction is a ligand dependent process, with a redox reaction taking place within the complex. It could further be shown that selective hydrogen abstraction plays an important role in the process of X-ray induced photoreduction. Based on the experimental results of this work, a model to describe X-ray induced photoreduction of metal organic complexes could be proposed. The process of X-ray induced hydrogen abstraction was further investigated in a combined X-ray and neutron diffraction study on the amino acids L-serine and L-alanine, which were used as model compounds for proteins, and the nucleoside deoxythymidine (thymidine) as a model for DNA. A damage mechanism for L-serine could be found. It involves the abstraction of two hydrogen atoms, one from the hydroxyl group and one from the adjacent methylene group. Such a hydrogen abstraction results in the formation of a carbonyl group. X-ray diffraction measurements on cyano- and methylcobalamin as well as on three metal amino acid complexes, containing nickel(II) and copper(II), respectively, were conducted to investigate the contribution of X-ray induced photoreduction to global radiation damage. Results from these measurements combined with the results from L-serine, L-alanine and thymidine allowed

  19. The effect of high-temperature treatment on the formation of nanoscale intermetallic compounds of transition metals in Al-Cu-Mn-Zr alloy

    Science.gov (United States)

    Monastyrska, Tetiana O.; Berezina, Alla L.; Labur, Tetiana M.; Molebny, Oleh A.; Kotko, Andrii V.

    2018-02-01

    The precipitation of intermetallic compounds of transition metals during aging of the Al-5.8%Cu-0.3%Mn-0.1%Zr alloy has been studied using DSC, resistometry, X-ray and transmission electron microscopy. In these age hardenable alloys, the nanoscale metastable Θ″ and Θ' phases of the Al2Cu compound are the main strengthening phases, which are formed at low temperature aging of T stresses, etc.) on the aging with the precipitation of strengthening phases has been investigated.

  20. ENVIROMETAL TECHNOLOGIES, INC., METAL-ENHANCED DECHLORINATION OF VOLATILE ORGANIC COMPOUNDS USING AN IN-SITU REACTIVE IRON WALL

    Science.gov (United States)

    This report summarizes the results of a field demonstration conducted under the SITE program. The technology that was demonstrated was a metal-enhanced dechlorination process developed by EnviroMetal Technologies, Inc. to treat groundwater contaminated with chlorinated volatile ...

  1. Immobilization of microorganisms. Part 1. Preparation of immobilized Lactobacillus bulgaricus

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K H

    1981-01-01

    The immobilization of Lactobacillus bulgaricus on polyacrylamide and on alginate beads was investigated. The most active immobilized cells were obtained by entrapment in Ca alginate beads. These immobilized microbial cells, when introduced into 4.5% lactose solution and whey solution showed maximum relative activity of 28% for lactose and 18% for whey compared to free cells.

  2. Limb immobilization and corticobasal syndrome.

    Science.gov (United States)

    Graff-Radford, Jonathan; Boeve, Bradley F; Drubach, Daniel A; Knopman, David S; Ahlskog, J Eric; Golden, Erin C; Drubach, Dina I; Petersen, Ronald C; Josephs, Keith A

    2012-12-01

    Recently, we evaluated two patients with corticobasal syndrome (CBS) who reported symptom onset after limb immobilization. Our objective was to investigate the association between trauma, immobilization and CBS. The charts of forty-four consecutive CBS patients seen in the Mayo Clinic Alzheimer Disease Research Center were reviewed with attention to trauma and limb immobilization. 10 CBS patients (23%) had immobilization or trauma on the most affected limb preceding the onset or acceleration of symptoms. The median age at onset was 61. Six patients manifested their first symptoms after immobilization from surgery or fracture with one after leg trauma. Four patients had pre-existing symptoms of limb dysfunction but significantly worsened after immobilization or surgery. 23 percent of patients had immobilization or trauma of the affected limb. This might have implications for management of CBS, for avoiding injury, limiting immobilization and increasing movement in the affected limb. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Performance of metal compound on thermolysis and electrolysis on sugar industries waste water treatment: COD and color removal with sludge analysis (batch-experiment)

    Science.gov (United States)

    Sahu, Omprakash

    2017-10-01

    The sugar cane industry is one of the most water demanding industries. Sugar industries consume and generate excess amount of water. The generated water contains organic compounds, which would cause pollution. The aim of this research work is to study the effectiveness of metal compound for treatment of sugar industry waste water by thermolysis and electrolysis process. The result shows ferrous metal catalyst shows 80 and 85 % chemical oxygen demand and color removal at pH 6, optimum mass loading 4 kg/m3, treatment temperature 85 °C and treatment time 9 h. When ferrous material was used as electrode, maximum 81 % chemical oxygen demand and 84 % color removal at pH 6, current density 156 Am-2, treatment time 120 min and anode consumption 0.7 g for 1.5 L wastewater were obtained.

  4. Effects of thermal desorption on the composition of two coking plant soils: Impact on solvent extractable organic compounds and metal bioavailability

    Energy Technology Data Exchange (ETDEWEB)

    Biache, Coralie [G2R UMR 7566, Nancy Universite, CNRS, Boulevard des Aiguillettes B.P. 239, F-54506 Vandoeuvre-les-Nancy (France); LIMOS UMR 7137, Nancy Universite, CNRS, Boulevard des Aiguillettes B.P. 239, F-54506 Vandoeuvre-les-Nancy (France)], E-mail: coralie.biache@g2r.uhp-nancy.fr; Mansuy-Huault, Laurence; Faure, Pierre [G2R UMR 7566, Nancy Universite, CNRS, Boulevard des Aiguillettes B.P. 239, F-54506 Vandoeuvre-les-Nancy (France); Munier-Lamy, Colette; Leyval, Corinne [LIMOS UMR 7137, Nancy Universite, CNRS, Boulevard des Aiguillettes B.P. 239, F-54506 Vandoeuvre-les-Nancy (France)

    2008-12-15

    To evaluate the efficiency and the influence of thermal desorption on the soil organic compartment, contaminated soils from coking plant sites (NM and H) were compared to their counterparts treated with thermodesorption. The extractable organic matter, and the metal content and distribution with soil compartments were studied. In both thermodesorbed soils, PAH (polycyclic aromatic hydrocarbon) degradation exceeded 90%. However, the thermal desorption led not only to a volatilization of the organic compounds but also to the condensation of extractable organic matter. The treatments only affected the Fe and Zn distribution within the more stable fractions, whereas the organic compound degradation did not affect their mobility and availability. - Thermal desorption does not induce a metal mobilization but condensation seems to occur during the treatment.

  5. Half-metallic ferromagnetism in full-Heusler compounds ACaX2 (A = K and Rb; X = N and O)

    International Nuclear Information System (INIS)

    Umamaheswari, R.; Vijayalakshmi, D.; Yogeswari, M.; Kalpana, G.

    2014-01-01

    Electronic structure and magnetic properties of hypothetical ACaX 2 (A = K and Rb; X= N and O) compounds in full-Heusler phase have been investigated based on density functional theory (DFT) within the local density approximation (LDA). The electronic band structures and density of states of these compounds show that the spin-down electrons have metallic, and the spin-up electrons have a semi conducting gap resulting in stable half-metallic ferromagnetic behaviour. The strong spin polarization of 2p states of N and O atoms is found to be the origin of ferromagnetism which results in a total magnetic moment of 3 μB and 1 μB respectively

  6. Electrochemical immobilization of biomolecules on gold surface modified with monolayered L-cysteine

    Energy Technology Data Exchange (ETDEWEB)

    Honda, Mitsunori, E-mail: honda.mitsunori@jaea.go.jp; Baba, Yuji; Sekiguchi, Tetsuhiro; Shimoyama, Iwao; Hirao, Norie

    2014-04-01

    Immobilization of organic molecules on the top of a metal surface is not easy because of lattice mismatch between organic and metal crystals. Gold atoms bind to thiol groups through strong chemical bonds, and a self-assembled monolayer of sulfur-terminated organic molecules is formed on the gold surface. Herein, we suggested that a monolayer of L-cysteine deposited on a gold surface can act as a buffer layer to immobilize biomolecules on the metal surface. We selected lactic acid as the immobilized biomolecule because it is one of the simplest carboxyl-containing biomolecules. The immobilization of lactic acid on the metal surface was carried out by an electrochemical method in an aqueous environment under the potential range varying from − 0.6 to + 0.8 V. The surface chemical states before and after the electrochemical reaction were characterized using X-ray photoelectron spectroscopy (XPS). The N 1s and C 1s XPS spectra showed that the L-cysteine-modified gold surface can immobilize lactic acid via peptide bonds. This technique might enable the immobilization of large organic molecules and biomolecules. - Highlights: • Monolayer l-cysteine deposited on Au surface as a buffer layer to immobilize biomolecules. • Lactic acid as the immobilized biomolecule as it is simple carboxyl-containing biomolecule. • X-ray photoelectron spectroscopy (XPS) of surface chemical states, before and after. • L-cysteine-modified Au surface can immobilize lactic acid via peptide bonds.

  7. Electrochemical immobilization of biomolecules on gold surface modified with monolayered L-cysteine

    International Nuclear Information System (INIS)

    Honda, Mitsunori; Baba, Yuji; Sekiguchi, Tetsuhiro; Shimoyama, Iwao; Hirao, Norie

    2014-01-01

    Immobilization of organic molecules on the top of a metal surface is not easy because of lattice mismatch between organic and metal crystals. Gold atoms bind to thiol groups through strong chemical bonds, and a self-assembled monolayer of sulfur-terminated organic molecules is formed on the gold surface. Herein, we suggested that a monolayer of L-cysteine deposited on a gold surface can act as a buffer layer to immobilize biomolecules on the metal surface. We selected lactic acid as the immobilized biomolecule because it is one of the simplest carboxyl-containing biomolecules. The immobilization of lactic acid on the metal surface was carried out by an electrochemical method in an aqueous environment under the potential range varying from − 0.6 to + 0.8 V. The surface chemical states before and after the electrochemical reaction were characterized using X-ray photoelectron spectroscopy (XPS). The N 1s and C 1s XPS spectra showed that the L-cysteine-modified gold surface can immobilize lactic acid via peptide bonds. This technique might enable the immobilization of large organic molecules and biomolecules. - Highlights: • Monolayer l-cysteine deposited on Au surface as a buffer layer to immobilize biomolecules. • Lactic acid as the immobilized biomolecule as it is simple carboxyl-containing biomolecule. • X-ray photoelectron spectroscopy (XPS) of surface chemical states, before and after. • L-cysteine-modified Au surface can immobilize lactic acid via peptide bonds

  8. Geochemical investigations into the retention of reactive carbon compounds for toxic heavy metals. Final report; Geochemische Untersuchungen zur Retention von reaktiven Kohlenstoffverbindungen fuer toxische Schwermetalle. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Kupsch, H.; Mansel, A.; Crustewitz, C.

    2003-03-01

    The composition, reactivity and stability of reactive organic carbon compounds adsorbed on geogenic matrices was investigated. The surface deposits of NOM and its dependence on geochemical parameters was investigated in selected geomatrices. The retention of toxic heavy metals on these surface deposits of NOM was investigated in consideration of the presence of hydroxy species and inorganic ligands. The investigations of the reactivity of the NOM species requires analyses of these compounds and of the heavy metals in the ultratracer region. This was possible by means of radiochemical methods that were further developed in the context of this project. Radioactive labeling of identified reactive carbon compounds, e.g. with radioactive iodine, on the one hand, and the use of radioactive Cu, Pb, Hg isotopes on the other hand enabled speciation analyses in the binary systems (heavy metal + geomatrix, heavy metal + reactive carbon compounds, reactive carbon compounds + geomatrix) and especially in the ternary system (heavy metal + geomatrix + reactive carbon compounds) in defined conditions. The special labelling techniques were a precondition for distribution measurements in the near-natural, low concentration range. (orig.) [German] Ziel des Projektes war es, mit der vorhandenen Analytik und Expertise die Zusammensetzung, die Reaktivitaet und die Stabilitaet der auf den geogenen Matrizes sorbierten reaktiven organischen Kohlenstoffverbindungen und die damit verbundenen Stoffumsaetze aufzuklaeren. An ausgewaehlten Geomatrizes wurde die Ausbildung von Oberflaechendepositen des NOM und deren Abhaengigkeit gegenueber geochemischen Parametern untersucht. Unter der Beruecksichtigung der Gegenwart von Hydroxyspezies und anorganischen Liganden wurde die Retention toxischer Schwermetalle an diesen Oberflaechendepositen des NOM untersucht. Die Untersuchungen zur Reaktivitaet der NOM-Spezies setzt eine Analytik dieser Verbindungen und der Schwermetalle im Ultraspurenbereich

  9. Wastewater parameters after the process of phosphorus compounds removal by the metal dissolution method in comparison with precipitation and electrocoagulation methods

    Directory of Open Access Journals (Sweden)

    Wysocka Izabela

    2017-03-01

    Full Text Available Precipitation methods are commonly used for removing phosphorus compounds from wastewater. Chemical precipitation method, based on adding iron, aluminium or calcium salts to the treated wastewater, is often used. Another possible way of precipitating phosphates is metal dissolution method, which is presented in this paper. The main difference between these two methods is how the phosphate precipitating ions are introduced to the wastewater.

  10. Transition metal-free oxidation of benzylic alcohols to carbonyl compounds by hydrogen peroxide in the presence of acidic silica gel

    Directory of Open Access Journals (Sweden)

    Hossein Ghafuri

    2015-01-01

    Full Text Available Oxidation of alcohols to carbonyl compounds has become an important issue in the process industry as well as many other applications. In this method, various benzylic alcohols were successfully converted to corresponding aldehydes and ketones under transition metal-free condition using hydrogen peroxide in the presence of some amount of catalytic acidic silica gel. Silica gel is inexpensive and available. One of the most important features of this method is its short reaction time.

  11. Membranes suited for immobilizing biomolecules

    NARCIS (Netherlands)

    2009-01-01

    The present invention relates to flow-through membranes suitable for the immobilization of biomols., methods for the prepn. of such membranes and the use of such membranes for the immobilization of biomols. and subsequent detection of immobilized biomols. The invention concerns a flow-through

  12. Spray pyrolysis synthesis of γ-Al_2O_3 supported metal and metal phosphide catalysts and their activity in the hydrodeoxygenation of a bio-oil model compound

    International Nuclear Information System (INIS)

    Ly, Hoang Vu; Im, Kyungmin; Go, Youngchae; Galiwango, Emmanuel; Kim, Seung-Soo; Kim, Jinsoo; Choi, Jae Hyung; Woo, Hee Chul

    2016-01-01

    Highlights: • Spherical γ-Al_2O_3 supported metal and metal phosphide catalysts were synthesized by spray pyrolysis method. • Hydrodeoxygenation (HDO) of 2-furyl methyl ketone (FMK) was conducted using metal/metal phosphide catalysts. • FMK was converted into 2-allyl furan and methyl cyclohexane. • The highest FMK conversion of 83% was achieved over 10 wt% Ni/γ-Al_2O_3 catalysts at reaction temperature of 400 °C. - Abstract: In this study, spherical γ-Al_2O_3 supported metal and metal phosphide (Ni, Co, Ni_2P and CoP) catalysts were successfully prepared by combining sol-gel and spray pyrolysis methods. First boehmite sol was prepared based on the Yoldas process and then the corresponding metal salts were added to the sol at the desired concentration, followed by spray pyrolysis of the mixed solution. As the well-mixed solution was transformed to spherical γ-Al_2O_3 supported metal and metal phosphide catalysts during spray pyrolysis process, the metal species were uniformly distributed in the mesoporous γ-Al_2O_3 supports. The product catalysts were investigated under different conditions for hydrodeoxygenation of bio-oil model compound, 2-furyl methyl ketone (FMK), which is the main component of the bio-oil product from pyrolysis of Saccharina japonica. Among the investigated catalysts, the 10 wt% Ni/γ-Al_2O_3 catalyst after calcination at 800 °C showed the highest FMK conversion of 83.02% at the reaction temperature of 400 °C. The gas and liquid products were analyzed by gas chromatography (GC) with TCD/FID detectors and GC–MS, respectively, to determine the product compositions.

  13. New metals

    International Nuclear Information System (INIS)

    Bergqvist, U.

    1983-12-01

    The aim of this report is to estimate the exposure to various metals and metal compounds and discuss the available information of the possible toxic effects of these metals and compounds. In the first section, some metals are defined as those with either a large or a fast increasing exposure to living organisms. The available information on toxicity is discussed in the second section. In the third section interesting metals are defined as compounds having a large exposure and an apparent insufficient knowledge of their possible toxic effects. Comments on each of these metals are also to be found in the third section. (G.B.)

  14. Uranium uptake by immobilized cells of Pseudomonas strain EPS 5028

    International Nuclear Information System (INIS)

    Pons, M.P.; Fuste, M.C.

    1993-01-01

    Polyacrylamide-gel-immobilized cells of Pseudomonas strain EPS 5028 were effective in the removal of uranium (U) from synthetic effluents. Metal accumulation was performed in an open system in columns filled with immobilized cells that were challenged with continuous flows containing U. Possible variable of the system were studied. Uranium uptake by the immobilized cells of this microorganism was affected by pH but not by temperature or flow rate. In addition, U binding could be interpreted in terms of the Freundlich adsorption isotherm indicating single-layer adsorption. The feasibility of reusing the immobilized cells was suggested after the recovery of U with a solution of 0.1 M sodium carbonate. (orig.)

  15. Immobilization of IFR salt wastes in mortar

    International Nuclear Information System (INIS)

    Fisher, D.F.; Johnson, T.R.

    1988-01-01

    Portland cement-base mortars are being considered for immobilizing chloride salt wastes from the fuel cycle of an integral fast reactor (IFR). The IFR is a sodium-cooled fast reactor with metal fuel. It has a close-coupled fuel cycle in which fission products are separated from the actinides in an electrochemical cell operating at 500 degrees C. This cell has a cadmium anode and a liquid salt electrolyte. The salt will be a low-melting mixture of alkaline and alkaline earth chlorides. This paper discusses one method being considered for immobilizing this treated salt, to disperse it in a portland cement-base motar, which would then be sealed in corrosion-resistant containers. For this application, the grout must be sufficiently fluid that it can be pumped into canisters where it will solidify into a strong, leach-resistant material

  16. Capture and immobilization of krypton-85

    International Nuclear Information System (INIS)

    Whitmell, D.S.; Geens, L.; Penzhorn, R.D.; Smith, M.J.S.

    1985-01-01

    It may become necessary to contain the krypton-85 released from nuclear fuel during reprocessing in order to reduce the exposure to the local population and the radioactive background throughout the world. A brief description is given of studies being carried out in the Indirect Action Programme. The separation of krypton from other off-gases by cryogenic distillation in the presence of oxygen is being studied at SCK/CEN Mol, together with the behavior of ozone in the distillation column. Two processes for the immobilization of krypton in solid forms have been successfully developed and demonstrated. At KfK Karlsruhe, krypton is encapsulated in vitrified zeolites; at AERE Harwell, krypton is immobilized within a metallic matrix. These processes offer excellent gas retention and either could be adopted for a reprocessing plant

  17. Transition metal-catalyzed carbocyclization of nitrogen and oxygen-tethered 1,n-enynes and diynes: synthesis of five or six-membered heterocyclic compounds.

    Science.gov (United States)

    Zhang, Di-Han; Zhang, Zhen; Shi, Min

    2012-10-25

    Cycloisomerization of 1,n-enynes and diynes is a powerful method in organic synthesis to access heterocyclic compounds and has drawn increasing attention from organic chemists. In this paper, we attempted to summarize our recent results on the transition metal-catalyzed cycloisomerization to synthesize five or six-membered heterocyclic compounds using 1,n-enynes and diynes having a propargylic ester moiety. First, we will describe the synthesis of 2,3-disubstituted 3-pyrrolines via gold catalyzed cycloisomerization of 1,6-diynes. In addition, we will also disclose a novel silver catalyzed tandem 1,3-acyloxy migration/Mannich-type addition/elimination of the sulfonyl group of N-sulfonylhydrazone-propargylic esters to 5,6-dihydropyridazin-4-one derivatives. Furthermore, we will introduce three interesting examples of the synthesis of bicyclic compounds via titanium or rhodium catalyzed carbocyclization of enynes. In this context, we have presented that 1,n-enynes and diynes containing propargylic esters are highly reactive and useful starting materials for the cycloisomerization catalyzed by a transition metal catalyst.

  18. Fabrication and characterization of nanostructured Fe3S4, an isostructural compound of half-metallic Fe3O4

    KAUST Repository

    Li, Peng

    2015-06-10

    High-purity, well-crystallized spinel Fe3S4 nanoplatelets were synthesized by the hydrothermal method, and the saturation magnetic moment of Fe3S4 was measured at 1.83 μB/f.u. The temperature-dependent resistivity of Fe3S4 was metallic-like for T < 180 K: room-temperature resistivity was measured at 7.711 × 103  μΩ cm. The anomalous Hall conductivity of Fe3S4 decreased with increasing longitudinal conductivity, in sharp contrast with the accepted theory of the anomalous Hall effect in a dirty-metal regime. Furthermore, negligible spin-dependent magnetoresistance was observed. Band structure calculations confirmed our experimental observations that Fe3S4 is a metal and not a half metal as expected.

  19. On the possibility concentrating mill sewage treatment from coordination compounds of heavy non-ferrous metals with flotation reagents

    International Nuclear Information System (INIS)

    Monastyrskaya, V.I.; Borovkov, G.A.; Tsalieva, A.G.

    1996-01-01

    Complexing in the system metal ion (M = Cd, Co, Cu, Ni, Pb, Zn) - ligand (ethylenediamine, pyridine, xanthate, thiourea) and sorption of the complexes formed by materials on the basis of polyacrylonitrile (PAN) sorbents have been studied by the methods of spectrophotometry and voltammetry. It has been ascertained that PAN fiber base filtering materials are efficient sorbents for complexes of heavy nonferrous metals with flotation reagents and can be successfully employed for sewage purification at concentrating mills. 17 refs.; 6 figs.; 4 tabs

  20. Synthesis and characterization of one- to three-dimensional compounds composed of paradodecatungstate-B cluster and transition metals as linkers

    International Nuclear Information System (INIS)

    Sun Chunyan; Liu Shuxia; Xie Linhua; Wang Chunling; Gao Bo; Zhang Chundan; Su Zhongmin

    2006-01-01

    Three new extended frameworks built from paratungstate and transition metals have been synthesized and characterized. In the compound Na 8 [{Cd (H 2 O) 2 }(H 2 W 12 O 42 )].32H 2 O (1), two neighboring paratungstate-B ions [H 2 W 12 O 42 ] 10- are linked by [Cd(H 2 O) 2 ] 2+ units, leading to the formation of infinite one-dimensional (1D) anion chain [{Cd(H 2 O) 2 }(H 2 W 12 O 42 )] n 8n- . The anion [{Co(H 2 O) 3 }{Co(H 2 O) 4 }(H 2 W 12 O 42 )] n 6n- of the compound Na 6 [{Co(H 2 O) 3 }{Co(H 2 O) 4 }(H 2 W 12 O 42 )].29H 2 O (2) shows a layer-like (2D) structure in which paratungstate-B units are linked by CoO 6 octahedra, while the anion [{Co(H 2 O) 3 } 3 (H 2 W 12 O 42 )] n 4n- of the compound (H 3 O + ) 3 [{Na(H 2 O) 4 }{Co(H 2 O) 4 } 3 (H 2 W 12 O 42 )].24.5H 2 O (3) is a three-dimensional (3D) anionic polymer that consists of paratungstate-B units linked by CoO 6 octahedra. Compound 3 can reversibly adsorb and desorb water molecules leading to the color reversibly change from pink to violet. The preliminary magnetic measurement and electrochemical properties of compounds are performed. The crystal structure of unexpected product Na 4 [NiW 6 O 24 H 6 ].13H 2 O (4) is described here for the rare report of crystal structure information on the Anderson-type polyoxotungstate which has nickel as a heteroatom. - Graphical abstract: Three new compounds with one- to three-dimensional extended frameworks built from [H 2 W 12 O 42 ] 10- anion and transition metals have been synthesized and characterized by elemental analyses, X-ray single-crystal analyses, magnetic measurement, XRPD, and cyclic voltammetry measurements. The cobalt containing compound exhibits interesting reversible sorption/desorption of water molecules

  1. Field Deployment for In-situ Metal and Radionuclide Stabilization by Microbial Metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Turick, C. E.; Knox, A. S.; Dixon, K. L.; Roseberry, R. J.; Kritzas, Y. G

    2005-09-26

    A novel biotechnology is reported here that was demonstrated at SRS that facilitates metal and actinide immobilization by incorporating the physiology and ecology of indigenous bacteria. This technology is based on our previous work with pyomelanin-producing bacteria isolated from SRS soils. Through tyrosine supplementation, overproduction of pyomelanin was achieved, which lead ultimately to metal and actinide immobilization, both in-vitro and in-situ. Pyomelanin is a recalcitrant microbial pigment and a humic type compound in the class of melanin pigments. Pyomelanin has electron shuttling and metal chelation capabilities and thus accelerates the bacterial reduction and/or immobilization of metals. Pyomelanin is produced outside the cell and either diffuses away or attaches to the cell surface. In either case, the reduced pyomelanin is capable of transferring electrons to metals as well as chelating metals. Because of its recalcitrance and redox cycling properties, pyomelanin molecules can be used over and over again for metal transformation. When produced in excess, pyomelanin produced by one bacterial species can be used by other species for metal reduction, thereby extending the utility of pyomelanin and further accelerating metal immobilization rates. Soils contaminated with Ni and U were the focus of this study in order to develop in-situ, metal bioimmobilization technologies. We have demonstrated pyomelanin production in soil from the Tims Branch area of SRS as a result of tyrosine amendments. These results were documented in laboratory soil column studies and field deployment studies. The amended soils demonstrated increased redox behavior and sequestration capacity of U and transition metals following pyomelanin production. Treatments incorporating tyrosine and lactate demonstrated the highest levels of pyomelanin production. In order to determine the potential use of this technology at other areas of SRS, pyomelanin producing bacteria were also quantified

  2. Analytical chemical system for the determination of heavy metals and organic compounds. Annual progress report, December 1, 1978-November 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Siggia, S.; Barnes, R.M.

    1979-10-24

    Progress has been made in the synthesis and characterization of new resins for sequestering inorganic and organic compounds. The capabilities of the poly(dithiocarbamate) resin have been extended, a new poly(acrylamidoxime) resin prepared and characterized, and a series of resins for organic compounds prepared and tested. Limited actual sample analyses have been performed with these resins. A new inductively coupled plasma source, spectrometer, and computer system have been received and they are undergoing tests and installation. With this system in place, the multielement analysis of metals during the forthcoming period will insure the application of sequestering resins to practical analysis of energy-related materials. An automated sample handling and data system has been designed, some components purchased, and construction is scheduled for 1980.

  3. Analytical chemical system for the determination of heavy metals and organic compounds. Annual progress report, December 1, 1978-November 30, 1979

    International Nuclear Information System (INIS)

    Siggia, S.; Barnes, R.M.

    1979-01-01

    Progress has been made in the synthesis and characterization of new resins for sequestering inorganic and organic compounds. The capabilities of the poly(dithiocarbamate) resin have been extended, a new poly(acrylamidoxime) resin prepared and characterized, and a series of resins for organic compounds prepared and tested. Limited actual sample analyses have been performed with these resins. A new inductively coupled plasma source, spectrometer, and computer system have been received and they are undergoing tests and installation. With this system in place, the multielement analysis of metals during the forthcoming period will insure the application of sequestering resins to practical analysis of energy-related materials. An automated sample handling and data system has been designed, some components purchased, and construction is scheduled for 1980

  4. Immobilization of enzymes by radiation

    International Nuclear Information System (INIS)

    Kaetsu, I.; Kumakura, M.; Yoshida, M.; Asano, M.; Himei, M.; Tamura, M.; Hayashi, K.

    1979-01-01

    Immobilization of various enzymes was performed by radiation-induced polymerization of glass-forming monomers at low temperatures. Alpha-amylase and glucoamylase were effectively immobilized in hydrophilic polymer carrier such as poly(2-hydroxyethyl methacrylate) and also in rather hydrophobic carrier such as poly(tetraethylene-glycol diacrylate). Immobilized human hemoglobin underwent the reversible oxygenation concomitantly with change of oxygen concentration outside of the matrices. (author)

  5. Effects of immobilization on spermiogenesis

    Science.gov (United States)

    Meitner, E. R.

    1980-01-01

    The influence of immobilization stress on spermiogenesis in rats was investigated. After 96 hour immobilization, histological changes began to manifest themselves in the form of practically complete disappearance of cell population of the wall of seminiferous tubule as well as a markedly increased number of cells with pathologic mitoses. Enzymological investigations showed various changes of activity (of acid and alkaline phosphatase and nonspecific esterase) in the 24, 48, and 96 hour immobilization groups.

  6. Novel pectin-silica hybrids used for immobilization of Trichosporon cutaneum cells efficient in removal of Cadmium and Copper ions from waste water

    International Nuclear Information System (INIS)

    Georgieva, N.; Rangelova, N.; Peshev, D.; Nenkova, S.

    2011-01-01

    New silica hybrid materials containing tetramethyl siloxane (TMOS) as an inorganic precursor and apple pectin (AP) as an organic compound were prepared. The quantity of organic substance was 5 and 50 wt% AP. The amorphous state of the samples was proved by X-ray diffraction analyses (XRD). The Infrared scattering spectra (IR) showed characteristic peaks for SiO2 network, as well as for pectin. The synthesized hybrid materials were applied as matrices for cells immobilization by attachment and entrapment of the filamentous yeast Trichosporon cutaneum R57. This strain showed considerable ability to remove cadmium and copper ions from aqueous solutions. Regarding heavy metal biosorption capacity, the attachment was found to be superior compared to the entrapment method as a technique for biomass immobilization. (authors) Key words: biomaterials, composite materials, microstructure, sol-gel preparation

  7. Hard X-ray PhotoElectron Spectroscopy of transition metal oxides: Bulk compounds and device-ready metal-oxide interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Borgatti, F., E-mail: francesco.borgatti@cnr.it [Istituto per lo Studio dei Materiali Nanostrutturati (ISMN), Consiglio Nazionale delle Ricerche (CNR), via P. Gobetti 101, Bologna I-40129 (Italy); Torelli, P.; Panaccione, G. [Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, Trieste I-34149 (Italy)

    2016-04-15

    Highlights: • Hard X-ray PhotoElectron Spectroscopy (HAXPES) applied to buried interfaces of systems involving Transition Metal Oxides. • Enhanced contribution of the s states at high kinetic energies both for valence and core level spectra. • Sensitivity to chemical changes promoted by electric field across metal-oxide interfaces in resistive switching devices. - Abstract: Photoelectron spectroscopy is one of the most powerful tool to unravel the electronic structure of strongly correlated materials also thanks to the extremely large dynamic range in energy, coupled to high energy resolution that this form of spectroscopy covers. The kinetic energy range typically used for photoelectron experiments corresponds often to a strong surface sensitivity, and this turns out to be a disadvantage for the study of transition metal oxides, systems where structural and electronic reconstruction, different oxidation state, and electronic correlation may significantly vary at the surface. We report here selected Hard X-ray PhotoElectron Spectroscopy (HAXPES) results from transition metal oxides, and from buried interfaces, where we highlight some of the important features that such bulk sensitive technique brings in the analysis of electronic properties of the solids.

  8. Hard X-ray PhotoElectron Spectroscopy of transition metal oxides: Bulk compounds and device-ready metal-oxide interfaces

    International Nuclear Information System (INIS)

    Borgatti, F.; Torelli, P.; Panaccione, G.

    2016-01-01

    Highlights: • Hard X-ray PhotoElectron Spectroscopy (HAXPES) applied to buried interfaces of systems involving Transition Metal Oxides. • Enhanced contribution of the s states at high kinetic energies both for valence and core level spectra. • Sensitivity to chemical changes promoted by electric field across metal-oxide interfaces in resistive switching devices. - Abstract: Photoelectron spectroscopy is one of the most powerful tool to unravel the electronic structure of strongly correlated materials also thanks to the extremely large dynamic range in energy, coupled to high energy resolution that this form of spectroscopy covers. The kinetic energy range typically used for photoelectron experiments corresponds often to a strong surface sensitivity, and this turns out to be a disadvantage for the study of transition metal oxides, systems where structural and electronic reconstruction, different oxidation state, and electronic correlation may significantly vary at the surface. We report here selected Hard X-ray PhotoElectron Spectroscopy (HAXPES) results from transition metal oxides, and from buried interfaces, where we highlight some of the important features that such bulk sensitive technique brings in the analysis of electronic properties of the solids.

  9. Structure and mechanical properties of parts obtained by selective laser melting of metal powder based on intermetallic compounds Ni3Al

    Science.gov (United States)

    Smelov, V. G.; Sotov, A. V.; Agapovichev, A. V.; Nosova, E. A.

    2018-03-01

    The structure and mechanical properties of samples are obtained from metal powder based on intermetallic compound by selective laser melting. The chemical analysis of the raw material and static tensile test of specimens were made. Change in the samples’ structure and mechanical properties after homogenization during four and twenty-four hours were investigated. A small-sized combustion chamber of a gas turbine engine was performed by the selective laser melting method. The print combustion chamber was subjected to the gas-dynamic test in a certain temperature and time range.

  10. Phase stability, magnetic, electronic, half-metallic and mechanical properties of a new equiatomic quaternary Heusler compound ZrRhTiIn: A first-principles investigation

    Science.gov (United States)

    Wang, Jia-Xing; Chen, Z. B.; Gao, Y. C.

    2018-05-01

    In this manuscript, we have studied the electronic, magnetic, half-metallic and mechanical properties of a new Zr-based equiatomic quaternary Heusler (EQH) compound, ZrRhTiIn using first-principles calculations. The generalized gradient approximation (GGA) calculation results imply that at its equilibrium lattice constant of 6.70 Å, ZrRhTiIn is a half-metallic material (HMM) with a considerable band gap (Ebg) of 0.530 eV and a spin-filter/half-metallic band-gap (EHM) of 0.080 eV in the minority-spin channel. For ZrRhTiIn, the formation energy of -2.738 eV and the cohesive energy of 21.38 eV indicate that it is a thermodynamically stable material according to theory. The minority-spin EHM arises from the hybridization among Zr-4d, Ti-3d and Rh-4d electrons. The calculated total magnetic moment of ZrRhTiIn is 2 μB, meeting the well-known Slater-Pauling rule Mt = Zt -18. Furthermore, uniform strain and tetragonal strain were applied in this work to examine the magneto-electronic and half-metallic behaviors of the ZrRhTiIn system. Finally, we show that ZrRhTiIn is mechanically stable, ductile and anisotropic.

  11. Heavy metal and persistent organic compound contamination in soil from Wenling: an emerging e-waste recycling city in Taizhou area, China.

    Science.gov (United States)

    Tang, Xianjin; Shen, Chaofeng; Shi, Dezhi; Cheema, Sardar A; Khan, Muhammad I; Zhang, Congkai; Chen, Yingxu

    2010-01-15

    The present study was conducted to investigate the levels and sources of heavy metals (Cu, Cr, Cd, Pb, Zn, Hg and As) and persistent organic compounds including polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in soils taken from Wenling, an emerging e-waste recycling city in Taizhou, China. The results suggested that most heavy metals exceeded the respective Grade II value of soil quality standards from State Environmental Protection Administration of China and also exceeded the Dutch optimum values. Total PAHs in soil ranged from 371.8 to 1231.2 microg/kg, and relatively higher PAHs concentrations were found in soils taken from simple household workshops. PCBs were detectable in all samples with total concentrations ranging from 52.0 to 5789.5 microg/kg, which were 2.1-232.5 times higher than that from the reference site (24.9 microg/kg). Results of this study suggested soil in the Wenling e-waste recycling area were heavily contaminated by heavy metals, PAHs and PCBs. Furthermore, compared with large-scale plants, simple household workshops contributed more heavy metals, PAHs and PCBs pollution to the soil environment, indicating that soil contamination from e-waste recycling in simple household workshops should be given more attention.

  12. A gold-immobilized microchannel flow reactor for oxidation of alcohols with molecular oxygen.

    Science.gov (United States)

    Wang, Naiwei; Matsumoto, Tsutomu; Ueno, Masaharu; Miyamura, Hiroyuki; Kobayashi, Shū

    2009-01-01

    Golden capillaries: A gold-immobilized capillary column reactor allows oxidation of alcohols to carbonyl compounds using molecular oxygen. These capillary columns (see picture) can be used for at least four days without loss of activity.

  13. Developing an Efficient and General Strategy for Immobilization of Small Molecules onto Microarrays Using Isocyanate Chemistry.

    Science.gov (United States)

    Zhu, Chenggang; Zhu, Xiangdong; Landry, James P; Cui, Zhaomeng; Li, Quanfu; Dang, Yongjun; Mi, Lan; Zheng, Fengyun; Fei, Yiyan

    2016-03-16

    Small-molecule microarray (SMM) is an effective platform for identifying lead compounds from large collections of small molecules in drug discovery, and efficient immobilization of molecular compounds is a pre-requisite for the success of such a platform. On an isocyanate functionalized surface, we studied the dependence of immobilization efficiency on chemical residues on molecular compounds, terminal residues on isocyanate functionalized surface, lengths of spacer molecules, and post-printing treatment conditions, and we identified a set of optimized conditions that enable us to immobilize small molecules with significantly improved efficiencies, particularly for those molecules with carboxylic acid residues that are known to have low isocyanate reactivity. We fabricated microarrays of 3375 bioactive compounds on isocyanate functionalized glass slides under these optimized conditions and confirmed that immobilization percentage is over 73%.

  14. Urinary arsenic, pesticides, heavy metals, phthalates, polyaromatic hydrocarbons, and polyfluoroalkyl compounds are associated with sleep troubles in adults: USA NHANES, 2005-2006.

    Science.gov (United States)

    Shiue, Ivy

    2017-01-01

    Links between environmental chemicals and human health have emerged, but the effects on sleep health were less studied. Therefore, the aim of the present study was to investigate the relationships of different sets of environmental chemicals and common sleep troubles in a national and population-based setting. Data were retrieved from the United States National Health and Nutrition Examination Surveys, 2005-2006 including demographics, serum measurements, lifestyle factors, self-reported sleep troubles, and urinary environmental chemical concentrations. Statistical analyses including descriptive statistics, t-test, chi-square test, and survey-weighted logistic regression models were performed. Of all 5563 Americans aged 18-85, 2331 (42.0%) had wake-up at night, 2914 (52.5%) felt unrested during the day, 740 (13.4%) had leg jerks while sleeping, and 1059 (19.1%) had leg cramps for 2+ times a month. Higher levels of urinary arsenic, phthalates, and polyfluoroalkyl compounds were associated with wake-up at night. Higher levels of urinary 4-tert-octylphenol and polyfluoroalkyl compounds were associated with being unrested during the day. Higher levels of urinary arsenic, polyaromatic hydrocarbons, and polyfluoroalkyl compounds were associated with leg jerks while sleeping. Higher levels of urinary pesticides, heavy metals, phthalates, and polyaromatic hydrocarbons were associated with leg cramps while sleeping. However, there were no significant associations with other environmental chemicals such as parabens, bisphenol A, benzophenone-3, triclosan, perchlorate, nitrate, or thiocyanate. Eliminating arsenic, heavy metals, phthalate, pesticides, polyaromatic hydrocarbons, and polyfluoroalkyl compounds to improve sleep health might be considered while understanding the biological pathway with a longitudinal or experimental approach in future research would be suggested.

  15. Structural, electronic, magnetic, half-metallic, mechanical, and thermodynamic properties of the quaternary Heusler compound FeCrRuSi: A first-principles study.

    Science.gov (United States)

    Wang, Xiaotian; Khachai, Houari; Khenata, Rabah; Yuan, Hongkuan; Wang, Liying; Wang, Wenhong; Bouhemadou, Abdelmadjid; Hao, Liyu; Dai, Xuefang; Guo, Ruikang; Liu, Guodong; Cheng, Zhenxiang

    2017-11-23

    In this paper, we have investigated the structural, electronic, magnetic, half-metallic, mechanical, and thermodynamic properties of the equiatomic quaternary Heusler (EQH) compound FeCrRuSi using the density functional theory (DFT) and the quasi-harmonic Debye model. Our results reveal that FeCrRuSi is a half-metallic material (HMM) with a total magnetic moment of 2.0 μ B in agreement with the well-known Slater-Pauling rule M t  = Z t  - 24. Furthermore, the origin of the half-metallic band gap in FeCrRuSi is well studied through a schematic diagram of the possible d-d hybridization between Fe, Cr and Ru elements. The half-metallic behavior of FeCrRuSi can be maintained in a relatively wide range of variations of the lattice constant (5.5-5.8 Å) under uniform strain and the c/a ratio (0.96-1.05) under tetragonal distortion. The calculated phonon dispersion, cohesive and formation energies, and mechanical properties reveal that FeCrRuSi is stable with an EQH structure. Importantly, the compound of interest has been prepared and is found to exist in an EQH type structure with the presence of some B2 disorder. Moreover, the thermodynamic properties, such as the thermal expansion coefficient α, the heat capacity C V , the Grüneisen constant γ, and the Debye temperature Θ D are calculated.

  16. Plutonium immobilization plant using ceramic in existing facilities at the Savannah River site

    International Nuclear Information System (INIS)

    DiSabatino, A.

    1998-01-01

    The Plutonium Immobilization Plant (PIP) accepts plutonium (Pu) from pit conversion and from non-pit sources, and through a ceramic immobilization process converts the plutonium into an immobilized form that can be disposed of in a high level waste (HLW) repository. This immobilization process is shown conceptually in Figure 1-1. The objective is to make an immobilized form, suitable for geologic disposal, in which the plutonium is as inherently unattractive and inaccessible as the plutonium in spent fuel from commercial reactors. The ceramic immobilization alternative presented in this report consists of first converting the surplus material to an oxide, followed by incorporating the plutonium oxide into a titanate-based ceramic material that is placed in metal cans

  17. ELECTRICAL PROPERTIES OF COMPOUNDS AND ALLOYS OF RARE-EARTH METALS WITH ELEMENTS OF GROUPS V AND VI

    Energy Technology Data Exchange (ETDEWEB)

    Reid, F. J.; Matson, L. K.; Miller, J. F.; Himes, R. C.

    1963-04-15

    The electric properties of rare earth compounds and alloys with As, Sb, Se, and Te are reported. Without exception, samples of Se and Te compounds with normally trivalent Nd, Gd, and Ce having synthetic compositions, MX and M/sub 3/X/ sub 4/, are n-type wrth free electron concentrations in the range 10/sup 20/ to 10 /sup 22//cm/sup 3/, and have very low electric resistivities. Room temperature electric properties and thermoelectric data are tabulated. (P.C H.)

  18. Surface half-metallicity of half-Heusler compound FeCrSe and interface half-metallicity of FeCrSe/GaP

    Energy Technology Data Exchange (ETDEWEB)

    Khalaf Al-zyadi, Jabbar M., E-mail: jabbar_alzyadi@yahoo.com [Department of Physics, College of Education for Pure Sciences, University of Basrah (Iraq); Jolan, Mudhahir H. [Department of Physics, College of Education for Pure Sciences, University of Basrah (Iraq); Yao, Kai-Lun, E-mail: klyao@mail.hust.edu.cn [School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074 (China); International Center of Materials Physics, Chinese Academy of Sciences, Shenyang 110015 (China)

    2016-04-01

    Recent studies showed that half-Heusler FeCrSe exhibits half-metallic ferromagnetism (Huang et al. [20]). In this paper, we investigate extensively the electronic, magnetic, and half-metallic properties of the half-Heusler alloy FeCrSe (111) and (001) surfaces and the interface with GaP (111) substrate by using the first-principles calculations within the density functional theory. The atomic density of states demonstrates that the half-me tallicity verified in the bulk FeCrSe is maintained at the CrSe-terminated (001) and Se-terminated (111) surfaces, but lost at both Cr- and Fe-terminated (111) surfaces and the Fe-terminated (001) surface. Alternatively, for the interface of FeCrSe/GaP (111), the bulk half-metallicity is destroyed at Se–P configuration while Se–Ga interface and subinterface show nearly 100% spin polarization. Moreover, the calculated interfacial adhesion energies exhibit that Se–Ga shape is more stable than the Se–P one. The calculated magnetic moments of Se, Ga at the Se–Ga (111) interface and P at the Se–P (111) interface increase with respect to the corresponding bulk values while the atomic magnetic moment of Se atom at the Se–P (111) interface decreases. We also notice that the magnetic moments of subinterface Fe at both Se–Ga and Se–P (111) interfaces decrease compared to the bulk values. - Highlights: • The half-metallicity verified in the bulk FeCrSe is kept at the CrSe-terminated (001) and Se-terminated (111) surfaces. • The calculated interfacial adhesion energies exhibit that Se–Ga shape is more stable than Se–P. • The magnetic moments of Se, Ga and P atoms at the interface increase. • The Se–Ga interface shows nearly 100% spin polarization.

  19. Biodegradation of chlorobenzene using immobilized crude extracts ...

    African Journals Online (AJOL)

    SERVER

    2007-10-04

    Oct 4, 2007 ... immobilized crude extracts were reused for all other experiments and found that immobilization .... India which are of analytical reagent grade. .... 9. 60. 3. 1. Figure 3. Degradation of chlorobenzene by immobilized crude.

  20. Supramolecular protein immobilization on lipid bilayers

    NARCIS (Netherlands)

    Bosmans, R.P.G.; Hendriksen, W.E.; Verheijden, Mark Lloyd; Eelkema, R.; Jonkheijm, Pascal; van Esch, J.H.; Brunsveld, Luc

    2015-01-01

    Protein immobilization on surfaces, and on lipid bilayers specifically, has great potential in biomolecular and biotechnological research. Of current special interest is the immobilization of proteins using supramolecular noncovalent interactions. This allows for a reversible immobilization and

  1. Iodine immobilization in apatites

    International Nuclear Information System (INIS)

    Audubert, F.; Lartigue, J.E.

    2000-01-01

    In the context of a scientific program on long-lived radionuclide conditioning, a matrix for iodine 129 immobilization has been studied. A lead vanado-phosphate apatite was prepared from the melt of lead vanado-phosphate Pb 3 (VO 4 ) 1.6 (PO 4 ) 0.4 and lead iodide PbI 2 in stoichiometric proportions by calcination at 700 deg. C during 3 hours. Natural sintering of this apatite is not possible because the product decomposition occurs at 400 deg. C. Reactive sintering is the solution. The principle depends on the coating of lead iodide with lead vanado-phosphate. Lead vanado-phosphate coating is used as iodo-apatite reactant and as dense covering to confine iodine during synthesis. So the best condition to immobilize iodine during iodo-apatite synthesis is a reactive sintering at 700 deg. C under 25 MPa. We obtained an iodo-apatite surrounded with dense lead vanadate. Leaching behaviour of the matrix synthesized by solid-solid reaction is under progress in order to determine chemical durability, basic mechanisms of the iodo-apatite alteration and kinetic rate law. Iodo-apatite dissolution rates were pH and temperature dependent. We obtained a rate of 2.5 10 -3 g.m -2 .d -1 at 90 deg. C in initially de-ionised water. (authors)

  2. Luminescence properties of Tb{sub 3}Al{sub 5}O{sub 12} garnet and related compounds synthesized by the metal organic decomposition method

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Yuya; Nakamura, Toshihiro, E-mail: tnakamura@gunma-u.ac.jp; Adachi, Sadao, E-mail: adachi@gunma-u.ac.jp

    2017-03-15

    The Tb–Al–O ternay compounds were prepared by the metal organic decompostion (MOD) method from mixted solutions of Al{sub 2}O{sub 3} and Tb{sub 4}O{sub 7} and subsequent calcination at T{sub c}=1200 °C in air. The structural and optical properties of the synthesized compounds were examined using X-ray diffraction analysis, photoluminescence (PL) analysis, PL excitation (PLE) spectroscopy, PL decay kinetics, and diffuse reflectance spetrosopy. The stoichiometric compounds of terbium aluminium garnet Tb{sub 3}Al{sub 5}O{sub 12} (TAG) and peroviskite-type TbAlO{sub 3} were synthesized at molar ratios of x=0.375 and 0.5 [x ≡Tb{sub 4}O{sub 7}/(Tb{sub 4}O{sub 7}+2Al{sub 2}O{sub 3})], together with the end-point binary materials of rhombohedral Al{sub 2}O{sub 3} (α-Al{sub 2}O{sub 3}; x=0) and cubic Tb{sub 4}O{sub 7} (x=1.0). One can also expect synthesis of stoichiometric compounds Tb{sub 4}Al{sub 2}O{sub 9} and Tb{sub 3}AlO{sub 12} at x=0.667 and 0.75, respectively; however, these compounds were found to be very difficult to synthesize by the MOD method or, probably by other methods. Temperature dependence of the PL spectra for TAG was measured from T=20–440 K in 10-K step and analyzed using a newly developed theoretical model. Raman scattering measurements were also performed on the Tb–Al–O material system with compositions widely varying from x=0 (α-Al{sub 2}O{sub 3}) to 1.0 (Tb{sub 4}O{sub 7}).

  3. A method of measuring the conductivity of air-sensitive substances in dependence on pressure (alkali metal anthracene addition compounds)

    International Nuclear Information System (INIS)

    Konrad Luehder, Konrad

    1996-01-01

    The conductivity of alkali anthracene addition compounds of the general formula M x (atc) with x=2.0 and = 1.5 was measured in dependence on pressure up to 400 MPa, shoving values in the range of 10 -8 S/cm. A suitable apparatus is described. (authors)

  4. Fabrication and characterization of nanostructured Fe3S4, an isostructural compound of half-metallic Fe3O4

    KAUST Repository

    Li, Peng; Xia, Chuan; Zhang, Qiang; Guo, Zaibing; Cui, Wenyao; Bai, Haili; Alshareef, Husam N.; Zhang, Xixiang

    2015-01-01

    High-purity, well-crystallized spinel Fe3S4 nanoplatelets were synthesized by the hydrothermal method, and the saturation magnetic moment of Fe3S4 was measured at 1.83 μB/f.u. The temperature-dependent resistivity of Fe3S4 was metallic

  5. A systematic study on the use of ultrasound energy for the synthesis of nickel-metal organic framework compounds

    NARCIS (Netherlands)

    Sargazi, G.; Afzali, D.; Daldosso, N.; Kazemian, H.; Chauhan, N.P.S.; Sadeghian, Z.; Tajerian, T.; Ghafarinazari, A.; Mozafari, M.

    2015-01-01

    A nickel metal-organic framework (Ni-MOF) was successfully synthesized using ultrasound irradiation. Further to this, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), Thermo-Gravimetric Analysis (TGA), Differential Scanning Calorimetry

  6. Determination of carbon in uranium and its compounds; Determinacion de carbono en uranio metal y sus compuestos

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Garcia, M M

    1972-07-01

    This paper collects the analytical methods used our laboratories for the determination of carbon in uranium metal, uranate salts and the oxides, fluorides and carbides of uranium. The carbon is usually burned off in a induction or resistance oven under oxygen flow. The CO{sub 2} is collected in barite solution. Where it is backtitrated with potassium biphthalate. (Author)

  7. Phytoremediation of soils co-contaminated by organic compounds and heavy metals: bioassays with Lupinus luteus L. and associated endophytic bacteria.

    Science.gov (United States)

    Gutiérrez-Ginés, M J; Hernández, A J; Pérez-Leblic, M I; Pastor, J; Vangronsveld, J

    2014-10-01

    In the central part of the Iberian Peninsula there are old sealed landfills containing soils co-contaminated by several heavy metals (Cu, Zn, Pb, Cd, Ni, As, Cr, Fe, Al, Mn) and organic pollutants of different families (hydrocarbons, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, pesticides and other organochlorinated compounds, phenols and volatile compounds), which this work will address. We have focused on phytoremedial plants that are able to deal with this type of complex pollution, not only species that tolerate the joint effect of heavy metals in the soil, but also those that can take advantage of associated bacteria to efficiently break down organic compounds. This study was carried out with Lupinus luteus and its endophytes in two greenhouse experiments: A) growing in a substrate artificially contaminated with benzo(a)pyrene (BaP), and B) using real co-contaminated landfill soils. Endophytes of roots and shoots were isolated in both bioassays. Plant growth-promotion tests and organic pollutant tolerance and degradation tests were conducted on all strains isolated in bioassay A), and on those proving to be pure cultures from bioassay B). The selected landfill is described as are isolation and test procedures. Results indicate that plants did not show toxicity symptoms when exposed to BaP but did when grown in landfill soil. Some endophytes demonstrated plant growth-promotion capacity and tolerance to BaP and other organic compounds (diesel and PCB commercial mixtures). A few strains may even have the capacity to metabolize those organic pollutants. The overall decline in plant growth-promotion capacity in those strains isolated from the landfill soil experiment, compared with those from the bioassay with BaP, may indicate that lupin endophytes are not adapted to metal concentration in roots and shoots and fail to grow. As a result, most isolated root endophytes must have colonized root tissues from the soil. While preliminary degradation tests

  8. Interplay of metals and bromine with dioxin-related compounds concentrated in e-waste open burning soil from Agbogbloshie in Accra, Ghana

    International Nuclear Information System (INIS)

    Fujimori, Takashi; Itai, Takaaki; Goto, Akitoshi; Asante, Kwadwo A.; Otsuka, Masanari; Takahashi, Shin; Tanabe, Shinsuke

    2016-01-01

    Open burning of electronic waste (e-waste) releases various metals and organohalogen compounds in the environment. Here we investigated the interplay of metals (Cu, Pb, Zn, Fe, Co, and Sr) and bromine (Br) in the formation of dioxin-related compounds (DRCs), including polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs), as well as non-regulated DRCs such as polybrominated dibenzo-p-dioxins/furans (PBDD/Fs) and their monobrominated PCDD/Fs in soils sampled from open burning e-waste sites at Agbogbloshie in Accra, Ghana. The predominant DRCs were PBDFs, PCDFs, PCDDs, and DL-PCBs. Statistical analyzes, X-ray absorption spectroscopy, and the PCDF/PCDD ratio suggested possible formation paths of PCDD/Fs and DL-PCBs by catalytic behaviors of copper chlorides (CuCl, CuCl_2, and Cu_2(OH)_3Cl) and thermal breakdown of polyvinyl chloride. Predominant formation of brominated furans may be derived from electron transfer from intermediates of PBDE to copper, Cu(II) → Cu(I). Lead chloride also contributed to generate DRCs and may become highly bioaccessible through the open burning of e-waste. The main zinc species (ZnCl_2 and ZnS) suggested a possible relationship to generate DRCs and specific zinc source such as tire burning. Cu, Pb, Zn, and Br contained in various e-wastes, wires/cables, plastics, and tires strongly influenced generation of many DRCs. - Highlights: • Extremely high DRCs were detected from an open burning soil of e-waste. • Predominant DRCs were PBDFs, PCDFs, PCDDs, and DL-PCBs. • Some metals shows good correlation to DRCs by PCA and cluster analysis. • Speciation of Cu, Pb, Zn in residual soil were successfully measured by XAFS. • Electron transfer via Cu(II) → Cu(I) can be important for DRCs formation. - Metals speciation in residual soil after open burning of e-waste may act as a catalyst for formation of dioxin-related compounds.

  9. Group 11 Metal Compounds with Tripodal Bis(imidazole Thioether Ligands. Applications as Catalysts in the Oxidation of Alkenes and as Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Armando Varela-Ramírez

    2011-08-01

    Full Text Available New group 11 metal complexes have been prepared using the previously described tripodal bis(imidazole thioether ligand (N-methyl-4,5-diphenyl-2-imidazolyl2C(OMeC(CH32S(tert-Bu ({BITOMe,StBu}, 2. The pincer ligand offers a N2S donor atom set that can be used to coordinate the group 11 metals in different oxidation states [AuI, AuIII, AgI, CuI and CuII]. Thus the new compounds [Au{BITOMe,StBu}Cl][AuCl4]2 (3, [Au{BITOMe,StBu}Cl] (4, [Ag{BITOMe,StBu}X] (X = OSO2CF3- 5, PF6- 6 and [Cu{BITOMe,StBu}Cl2] (7 have been synthesized from reaction of 2 with the appropriate metal precursors, and characterized in solution. While attempting characterization in the solid state of 3, single crystals of the neutral dinuclear mixed AuIII-AuI species [Au2{BITOMe,S}Cl3] (8 were obtained and its crystal structure was determined by X-ray diffraction studies. The structure shows a AuIII center coordinated to the pincer ligand through one N and the S atom. The soft AuI center coordinates to the ligand through the same S atom that has lost the tert-butyl group, thus becoming a thiolate ligand. The short distance between the AuI-AuIII atoms (3.383 Å may indicate a weak metal-metal interaction. Complexes 2-7 and the previously described CuI compound [Cu{BITOMe,StBu}]PF6 (9 have been evaluated in the oxidation of biphenyl ethylene with tert-butyl hydrogen peroxide (TBHP as the oxidant. Results have shown that the AuI and AgI complexes 4 and 6 (at 10 mol % loading are the more active catalysts in this oxidative cleavage. The antimicrobial activity of compounds 2-5, 7 and 9 against Gram-positive and Gram-negative bacteria and yeast has also been evaluated. The new gold and silver compounds display moderate to high antibacterial activity, while the copper derivatives are mostly inactive. The gold and silver complexes were also potent against fungi. Their cytotoxic properties have been analyzed in vitro utilizing HeLa human cervical carcinoma cells. The compounds displayed a

  10. Combined effects of ultrasonic vibration and manganese on Fe-containing inter-metallic compounds and mechanical properties of Al-17Si alloy with 3wt.%Fe

    Directory of Open Access Journals (Sweden)

    Lin Chong

    2013-05-01

    Full Text Available The research studied the combined effects of ultrasonic vibration (USV and manganese on the Fe-containing inter-metallic compounds and mechanical properties of Al-17Si-3Fe-2Cu-1Ni (wt.% alloys. The results showed that, without USV, the alloys with 0.4wt.% Mn or 0.8wt.% Mn both contain a large amount of coarse plate-like δ-Al4(Fe,MnSi2 phase and long needle-like β-Al5(Fe,MnSi phase. When the Mn content changes from 0.4wt.% to 0.8wt.% in the alloys, the amount and the length of needle-like β-Al5(Fe,MnSi phase decrease and the plate-like δ-Al4(Fe,MnSi2 phase becomes much coarser. After USV treatment, the Fe-containing compounds in the alloys are refined and exist mainly as δ-Al4(Fe,MnSi2 particles with an average grain size of about 20 μm, and only a small amount of β-Al5(Fe,MnSi phase remains. With USV treatment, the ultimate tensile strengths (UTS of the alloys containing 0.4wt.%Mn and 0.8wt.%Mn at room temperature are 253 MPa and 262 MPa, respectively, and the ultimate tensile strengths at 350 °C are 129 MPa and 135 MPa, respectively. It is considered that the modified morphology and uniform distribution of the Fe-containing inter-metallic compounds, which are caused by the USV process, are the main reasons for the increase in the tensile strength of these two alloys.

  11. Assessing attitudes toward spinal immobilization.

    Science.gov (United States)

    Bouland, Andrew J; Jenkins, J Lee; Levy, Matthew J

    2013-10-01

    Prospective studies have improved knowledge of prehospital spinal immobilization. The opinion of Emergency Medical Services (EMS) providers regarding spinal immobilization is unknown, as is their knowledge of recent research advances. To examine the attitudes, knowledge, and comfort of prehospital and Emergency Department (ED) EMS providers regarding spinal immobilization performed under a non-selective protocol. An online survey was conducted from May to July of 2011. Participants were drawn from the Howard County Department of Fire and Rescue Services and the Howard County General Hospital ED. The survey included multiple choice questions and responses on a modified Likert scale. Correlation analysis and descriptive data were used to analyze results. Comfort using the Kendrick Extrication Device was low among ED providers. Experienced providers were more likely to indicate comfort using this device. Respondents often believed that spinal immobilization is appropriate in the management of penetrating trauma to the chest and abdomen. Reported use of padding decreased along with the frequency with which providers practice and encounter immobilized patients. Respondents often indicated that they perform spinal immobilization due solely to mechanism of injury. Providers who feel as if spinal immobilization is often performed unnecessarily were more likely to agree that immobilization causes an unnecessary delay in patient care. The results demonstrate the need for improved EMS education in the use of the Kendrick Extrication Device, backboard padding, and spinal immobilization in the management of penetrating trauma. The attitudes highlighted in this study are relevant to the implementation of a selective spinal immobilization protocol. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Studies on unusually reactive metal powders. Preparation of new organometallic and organic compounds including potential new catalysts. Final report, July 1, 1980-December 31, 1984

    International Nuclear Information System (INIS)

    Rieke, R.D.

    1985-06-01

    This research project was involved with the preparation and study of highly reactive metal powders prepared by the reduction of metal salts with alkali metals. Studies concentrated on nickel, copper, cadmium, uranium, iron, and magnesium. The nickel powders have been found to react rapidly with benzylic halides, and the resulting organonickel complexes yield dibenzyl. Aryl halides react rapidly with the nickel powders to produce biaryl compounds in high yields. Benzylic halides react with the nickel powders in the presence of acylhalides to produce benzyl ketones in high yields. Reactions of ROCOCOC1 and benzylic halides with nickel powders yield benzyl ketones. These reactions proceed with a wide variety of substituents on the phenyl ring of the benzylic halides. Highly reactive uranium has been prepared, and found to react with a variety of oxygen containing substrates, such as nitrobenzene to yield azo benzene. Highly reactive magnesium has opened up a totally new area of low temperature Grignard chemistry. The preparation of highly reactive copper has allowed the direct preparation of organocopper species directly from organic halides. 16 refs., 6 tabs

  13. Catalytic activity of laminated compounds of graphite with transitions metals in decomposition of alcohols and formic acid

    International Nuclear Information System (INIS)

    Novikov, Yu.N.; Lapkina, N.D.; Vol'pin, M.E.

    1976-01-01

    The catalytic activity is studied of laminated graphite compounds with Fe, Co, Ni, Cu, Mo, W and Mn both in the reduced and oxidized forms in gas phase decomposition reactions of isopropyl, n-butyl, cyclohexyl, and 4-tret-butylcyclohexyl alcohols, and also formic acid. All the catalysts are shown to be active in the reactions where isopropyl and n-butyl alcohols undergo decomposition. The laminated compounds of graphite with Co and Ni both in the oxidized and reduction form are the most active catalysts of the selective decomposition of alcohols to aldehydes and ketones, and also formic acid to CO 2 and H 2 . The kinetics of a number of reactions is found to obey the second order equation with allowance made for the system volume

  14. Empirical evaluation of metal deposition for the analysis of organic compounds with static secondary ion mass spectrometry (S-SIMS)

    International Nuclear Information System (INIS)

    Mondt, R. de; Adriaensen, L.; Vangaever, F.; Lenaerts, J.; Vaeck, L. van; Gijbels, R.

    2006-01-01

    Metal-assisted (MetA) SIMS using the deposition of a thin Au or Ag layer on non-conducting samples prior to analysis has been advocated as a means to improve the secondary ion (S.I.) yields of organic analytes. This study focuses on the influence of time and temperature on the yield enhancement in MetA-SIMS using thick layers of poly(vinylbutyral-co-vinylalcohol-co-vinylacetate) (PVB) containing dihydroxybenzophenone (DHBPh) or a cationic carbocyanine dye (CBC) and spin-coated layers of the cationic dye on Si. Pristine samples as well as Au- and Ag-coated ones were kept between -8 deg. C and 80 deg. C and analysed with S-SIMS at intervals of a few days over a period of 1 month. The yield enhancement was found to depend strongly on the kind of evaporated metal, the storage temperature and time between coating and analysis

  15. Metals and organic compounds in the biosynthesis of cannabinoids: a chemometric approach to the analysis of Cannabis sativa samples.

    Science.gov (United States)

    Radosavljevic-Stevanovic, Natasa; Markovic, Jelena; Agatonovic-Kustrin, Snezana; Razic, Slavica

    2014-01-01

    Illicit production and trade of Cannabis sativa affect many societies. This drug is the most popular and easy to produce. Important information for the authorities is the production locality and the indicators of a particular production. This work is an attempt to recognise correlations between the metal content in the different parts of C. sativa L., in soils where plants were cultivated and the cannabinoids content, as a potential indicator. The organic fraction of the leaves of Cannabis plants was investigated by GC-FID analysis. In addition, the determination of Cu, Fe, Cr, Mn, Zn, Ca and Mg was realised by spectroscopic techniques (FAAS and GFAAS). In this study, numerous correlations between metal content in plants and soil, already confirmed in previous publications, were analysed applying chemometric unsupervised methods, that is, principal component analysis, factor analysis and cluster analysis, in order to highlight their role in the biosynthesis of cannabinoids.

  16. Regioselective C-H imidation of five-membered heterocyclic compounds through a metal catalytic or organocatalytic approach.

    Science.gov (United States)

    Wang, Xin; Sun, Kai; Lv, Yunhe; Ma, Fengji; Li, Gang; Li, Donghui; Zhu, Zhonghong; Jiang, Yongqing; Zhao, Feng

    2014-12-01

    An efficient method for the synthesis of 2-amino and β-amino five-membered heterocyclic derivatives that are closely related to a variety of biologically active natural products is described. Regioselectivity was achieved through a metal catalytic or organocatalytic approach. Preliminary studies on the reaction mechanism suggest a radical imidation pathway; however, further studies are needed to verify the mechanism. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. EDDS and EDTA-enhanced phytoextraction of metals from artificially contaminated soil and residual effects of chelant compounds

    Energy Technology Data Exchange (ETDEWEB)

    Luo Chunling [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); Shen Zhenguo [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Lou Laiqing [College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Li Xiangdong [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China)]. E-mail: cexdli@polyu.edu.hk

    2006-12-15

    The potential of 18 different plants to be used in the chemically enhanced phytoextraction of Cu, Pb, Zn and Cd was assessed using pot experiments. Chrysanthemum coronarium L. was the species most sensitive to the application of EDTA, and had the highest enhancement of Cu and Pb concentrations in its shoots. Compared with EDTA, EDDS was more effective in enhancing the concentration of Cu in the shoots of Chrysanthemum coronarium L. and Zea mays L. grown on multi-metal contaminated soils. The EDTA-treated soil still had a significant ability to enhance the concentrations of Cu and Pb in the shoots of Zea mays L. six months after the chelant treatment. However, the EDDS-treated soil did not have any effect in enhancing the concentrations of metals in the shoots of Zea mays L. in the second crop test. The results may indicate that EDDS biodegrades more rapidly than EDTA in soil and is better in limiting potential metal leaching. - Chrysanthemum coronarium L. was the most sensitive species to the application of chelants, and EDDS biodegrades much more rapidly than EDTA in soil.

  18. EDDS and EDTA-enhanced phytoextraction of metals from artificially contaminated soil and residual effects of chelant compounds

    International Nuclear Information System (INIS)

    Luo Chunling; Shen Zhenguo; Lou Laiqing; Li Xiangdong

    2006-01-01

    The potential of 18 different plants to be used in the chemically enhanced phytoextraction of Cu, Pb, Zn and Cd was assessed using pot experiments. Chrysanthemum coronarium L. was the species most sensitive to the application of EDTA, and had the highest enhancement of Cu and Pb concentrations in its shoots. Compared with EDTA, EDDS was more effective in enhancing the concentration of Cu in the shoots of Chrysanthemum coronarium L. and Zea mays L. grown on multi-metal contaminated soils. The EDTA-treated soil still had a significant ability to enhance the concentrations of Cu and Pb in the shoots of Zea mays L. six months after the chelant treatment. However, the EDDS-treated soil did not have any effect in enhancing the concentrations of metals in the shoots of Zea mays L. in the second crop test. The results may indicate that EDDS biodegrades more rapidly than EDTA in soil and is better in limiting potential metal leaching. - Chrysanthemum coronarium L. was the most sensitive species to the application of chelants, and EDDS biodegrades much more rapidly than EDTA in soil

  19. Chemistry, spectroscopy and isotope separation of zirconium and its compounds as revealed by laser diagnostics of laser produced metal beams

    International Nuclear Information System (INIS)

    Hackett, P.A.; Humphries, M.; Rayner, D.M.; Bourne, O.L.; Mitchell, A.

    1986-01-01

    Recent work from the author's laboratory on zirconium beams is reviewed. Zirconium metal beams have been produced by laser vaporization of solid zirconium targets coupled with supersonic expansion of helium gas. The resultant supersonic metal beam is shown to present an ideal environment for various spectroscopic techniques. The state distribution of zirconium atoms in the beam is obtained from low resolution laser induced fluorescence (LIF) studies. High resolution LIF studies give information on the hyperfine splitting in the ground state of the zirconium-91 isotope. Information on the hyperfine splitting in the excited state is obtained from quantum beat spectroscopy. Low resolution 2 color multiphoton ionization spectroscopy using a XeCl laser allows isotope separation of all isotopes of zirconium. These metal beams are highly reactive and can be used to produce novel chemical species. The results of two studies in which a reactant is added to the expansion gas are reported here. Zirconium oxide (ZrO), a molecule observed in the emission spectra of cool stars and in laboratory studies at high temperatures, is produced in a low temperature, collision free environment by adding small quantities of oxygen to the expansion gas. Zirconium fluoride (ZrF), a molecule previously unobserved, is produced by the addition of small quantities of CF/sub 4/

  20. Fluconazole affects the alkali-metal-cation homeostasis and susceptibility to cationic toxic compounds of Candida glabrata.

    Science.gov (United States)

    Elicharova, Hana; Sychrova, Hana

    2014-08-01

    Candida glabrata is a salt-tolerant and fluconazole (FLC)-resistant yeast species. Here, we analyse the contribution of plasma-membrane alkali-metal-cation exporters, a cation/proton antiporter and a cation ATPase to cation homeostasis and the maintenance of membrane potential (ΔΨ). Using a series of single and double mutants lacking CNH1 and/or ENA1 genes we show that the inability to export potassium and toxic alkali-metal cations leads to a slight hyperpolarization of the plasma membrane of C. glabrata cells; this hyperpolarization drives more cations into the cells and affects cation homeostasis. Surprisingly, a much higher hyperpolarization of C. glabrata plasma membrane was produced by incubating cells with subinhibitory concentrations of FLC. FLC treatment resulted in a substantially increased sensitivity of cells to various cationic drugs and toxic cations that are driven into the cell by negative-inside plasma-membrane potential. The effect of the combination of FLC plus cationic drug treatment was enhanced by the malfunction of alkali-metal-cation transporters that contribute to the regulation of membrane potential and cation homeostasis. In summary, we show that the combination of subinhibitory concentrations of FLC and cationic drugs strongly affects the growth of C. glabrata cells. © 2014 The Authors.

  1. An Evaluation of Kinetic Parameters of Cadmium and Copper Biosorption by Immobilized Cells

    Directory of Open Access Journals (Sweden)

    Nelly Georgieva

    2007-10-01

    Full Text Available Bioremediation is the use of living organisms to reduce or eliminate environmental hazards resulting from the accumulation of toxic chemicals and other hazardous wastes. This technology is based on the utilization of microorganisms to transform organic and inorganic compounds. The filamentous yeast Trichosporon cutaneum strain R57, immobilized and free cells was cultivated as batch culture on a liquid medium in the presence of various concentrations of cadmium and copper ions. The simultaneous uptake and accumulation of Cd2+ and Cu2+ ions by Tr. cutaneum cells depending on the initial concentration of Cd2+ and Cu2+ in the medium were studied. The potential use of the free and immobilized cells of Trichosporon cutaneum to remove cadmium and copper ions, from aqueous solutions was evaluated. Two important physicochemical aspects for the evaluation of the sorption process as a unit operation are the equilibrium of sorption and the kinetics. The Cd2+ and Cu2+ ions biosorption capacities of all tested adsorbent were presented as a function of the initial concentration of metal ions within the aqueous biosorption medium. The individual, as well as bicomponent sorption kinetics of copper and cadmium ions by immobilised cells of Trichosporon cutaneum R57 is presented. A second order kinetic model obtains kinetic parameters for the copper and cadmium ions.

  2. A preliminary study on the effects of sewage sludge disposal on soil polluted by heavy metals

    International Nuclear Information System (INIS)

    Calace, N.; Maggi, C.; Pellegrini, F.; Petronio, B. M.; Pietroletti, M.

    1998-01-01

    A preliminary study on the effects of sewage sludge disposal on soil polluted by heavy metal has been carried out in order to evaluate the possibility of reducing heavy metal mobility. Sewage sludge disposal on soil polluted by zinc and lead can modify their speciation, immobilizing a portion of metal present in mobile forms. In this way environmental hazards due to heavy metal presence can be reduced, because these derive essentially from the amount of metal present in mobile chemical forms. The results obtained show that sludge addition increases the fraction of metal sorbed from the soil; the characterization of the sludge before and after the treatment with the soil point out that this behaviour can be ascribed both to organic substances present in the sludge with the creation of new adsorbing sites, and to an increase of the ph value of the soil, due to the organic and inorganic compounds in the sludge [it

  3. HLW immobilization in glass

    International Nuclear Information System (INIS)

    Leroy, P.; Jacquet-Francillon, N.; Runge, S.

    1992-01-01

    The immobilization of High Level Waste in glass in France is a long history which started as early as in the 1950's. More than 30 years of Research and Development have been invested in that field. Two industrial facilities are operating (AVM and R7) and a third one (T7), under cold testing, is planned to start active operation in the mid-92. While vitrification has been demonstrated to be an industrially mastered process, the question of the quality of the final waste product, i.e. the HLW glass, must be addressed. The scope of the present paper is to focus on the latter point from both standpoints of the R and D and of the industrial reality

  4. Study on immobilization technology of krypton gas by ion-implantation and sputtering process

    International Nuclear Information System (INIS)

    Hayashi, S.; Kamiya, S.; Ikeda, S.; Nakanishi, Y.

    1997-01-01

    At the Waste Technology Development Division of PNC''s Tokai Works, we have been carrying out the development of the recovering and storing technology of radioactive krypton to reduce the radioactive gaseous effluent released to the environment arising from reprocessing of nuclear spent fuels. As a part of this technical development, the method of storing radioactive krypton is an encapsulation in a metal matrix which appears to offer the most secure immobilization of krypton. From the result of the ion-implantation test used non-radioactive krypton and the evaluation of electrical characteristics, we have selected the metallic materials, they are Nickel and Yttrium, and designed the vessel and the apparatus which continuously immobilized the krypton into metal matrix. This article described the following experiment result. (1) The long-term immobilization technology was established with respect to handling a equipment and plasma controlling. (2) Stability of the krypton immobilized alloy was considered satisfactory because the release was tolerably small. (author)

  5. Simultaneous Patterning of Independent Metal/Metal Oxide Multi-Layer Films Using Two-Tone Photo-Acid Generating Compound Systems

    Directory of Open Access Journals (Sweden)

    Hideo Honma

    2012-10-01

    Full Text Available (1 The photo-induced solubility and positive-tone direct photo-patterning of iron, copper and lanthanides chelated with 4-(2-nitrobenzyloxycarbonylcatechol (NBOC or 4-(6-nitroveratryloxycarbonylcatechol (NVOC was investigated. Photo-patterning of iron, copper, cerium, samarium, europium, terbium, dysprosium, holmium, erbium and lutetium complexes was accomplished. Continuous films were formed by the pyrolysis of metal complex films at 500 °C. (2 Based on the difference in the photo-reaction excitation wavelength profile of NBOC and NVOC complexes, a short and simple method for simultaneous micro-patterning of two independent films on each side of a transparent glass substrate was developed. Using the developed procedure, indium tin oxide and/or titanium oxide films were formed on each side of a quartz substrate without use of resist or etching.

  6. Ground state properties and thermoelectric behavior of Ru{sub 2}VZ (Z=Si, ge, sn) half-metallic ferromagnetic full-Heusler compounds

    Energy Technology Data Exchange (ETDEWEB)

    Yalcin, Battal Gazi

    2016-06-15

    The ground state properties namely structural, mechanical, electronic and magnetic properties and thermoelectric behavior of Ru{sub 2}VZ (Z=Si, Ge and Sn) half-metallic ferromagnetic full-Heusler compounds are systematically investigated. These compounds are ferromagnetic and crystallize in the Heusler type L2{sub 1} structure (prototype: Cu{sub 2}MnAl, Fm-3m 225). This result is confirmed for Ru{sub 2}VSi and Ru{sub 2}VSn by experimental work reported by Yin and Nash using high temperature direct reaction calorimetry. The studied materials are half-metallic ferromagnets with a narrow direct band gap in the minority spin channel that amounts to 31 meV, 66 meV and 14 meV for Ru{sub 2}VSi, Ru{sub 2}VGe, and Ru{sub 2}VSn, respectively. The total spin magnetic moment (M{sub tot}) of the considered compounds satisfies a Slater–Pauling type rule for localized magnetic moment systems (M{sub tot}=(N{sub V}−24)µ{sub B}), where N{sub V}=25 is the number of valence electrons in the primitive cell. The Curie temperature within the random phase approximation (RPA) is found to be 23 K, 126 K and 447 K for Ru{sub 2}VSi, Ru{sub 2}VGe and Ru{sub 2}VSn, respectively. Semi-classical Boltzmann transport theories have been used to obtain thermoelectric constants, such as Seebeck coefficient (S), electrical (σ/τ) and thermal conductivity (κ/τ), power factor (PF) and the Pauli magnetic susceptibility (χ). ZT{sub MAX} values of 0.016 (350 K), 0.033 (380 K) and 0.063 (315 K) are achieved for Ru{sub 2}VSi, Ru{sub 2}VGe and Ru{sub 2}VSn, respectively. It is expected that the obtained results might be a trigger in future experimentally interest in this type of full-Heusler compounds. - Graphical abstract: Temperature dependence of figure of merit for Ru{sub 2}VZ (Z=Si, Ge, and Sn) compounds. - Highlights: • The ground state and thermoelectric properties are reported for the first time. • Ru{sub 2}VZ are found to be a half-metallic ferromagnetic full Heusler compound. • The

  7. Wettability of hot-pressed samples of boron-containing aluminium compounds by liquid metals and alloys

    International Nuclear Information System (INIS)

    Kharlamov, A.I.; Nizhenko, V.I.; Kirillova, N.V.; Floka, L.I.

    2000-01-01

    Highly dispersed powders of aluminium borides and borocarbides were sintered by hot pressing method. Temperature dependence of wettability of hot-pressed boride samples (α-AlB 12 and AlB 18 ) and aluminium borocarbides (Al 3 B 48 C 2 , Al 8 B 4 C 2 and AlB 24 C) by liquid aluminium, copper, germanium, silicon and melts Al + 25 wt.%Si and Cu + (3-6) wt.%Ti was studied. Dependence of a compound wettability on the ratio of components in it was analyzed [ru

  8. A new insight into the immobilization mechanism of Zn on biochar: the role of anions dissolved from ash

    OpenAIRE

    Tingting Qian; Yujun Wang; Tingting Fan; Guodong Fang; Dongmei Zhou

    2016-01-01

    Biochar is considered to be a promising material for heavy metal immobilization in soil. However, the immobilization mechanisms of Zn2+ on biochars derived from many common waste biomasses are not completely understood. Herein, biochars (denoted as PN350, PN550, WS350, and WS550) derived from pine needle (PN) and wheat straw (WS) were prepared at two pyrolysis temperatures (350??C and 550??C). The immobilization behaviors and mechanisms of Zn2+ on these biochars were systematically investigat...

  9. [Native, modified, and immobilized chymotrypsin in chaotropic media. Stabilization limits].

    Science.gov (United States)

    Panova, A A; Levitskiĭ, V Iu; Mozhaev, V V

    1994-07-01

    To stabilize alpha-chymotrypsin against irreversible thermal inactivation at high temperatures, methods of covalent modification and multi-point immobilization in combination with the addition of salting-in compounds were used. The upper limit of the protein stability proved to be the same for a combination of the modification and salting-in media and for each of these methods separately. The limit of stabilization reached by means of covalent immobilization is higher than the limit of stabilization reached by two other methods. The greatest stabilization of immobilized alpha-chymotrypsin by the salting-in media (a 10000 fold increase in the native enzyme's stability level) takes place only in the case of the protein with the minimum number of bonds with the support. Stabilization of the enzyme by these methods is explained in terms of the suppression of the conformational inactivation processes.

  10. Removal of Cadmium and Zinc from Soil using Immobilized Cell of Biosurfactant Producing Bacteria

    Directory of Open Access Journals (Sweden)

    Charoon Sarin

    2010-07-01

    Full Text Available Immobilized biosurfactant producing bacteria (Bacillus subtilis TP8 and Pseudomonas fluorescens G7 were assessed for survival in heavy metal contaminated soil and for their ability to remove cadmium and zinc from contaminated soil. P. fluorescens G7 was considered to be a good candidate for bioremediation of heavy metals because of its high minimum inhibitory concentrations (MIC for each heavy metal and because of the obviously increased numbers of cell surviving after incubation in the heavy metal contaminated soil up to 4 weeks. The results of soil remediation showed that approximately 19% of Zn and 16.7% of Cd could be removed by this immobilized biosurfactant producing bacteria after incubation for 2 weeks. The results confirm the potential applicability of the immobilized biosurfactant producing bacteria for heavy metal bioremediation.

  11. FINAL TECHNICAL REPORT Synthetic, Structural and Mechanistic Investigations of Olefin Polymerization Catalyzed by Early Transition Metal Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Bercaw, John E. [California Institute of Technology

    2014-05-23

    The goal of this project is to develop new catalysts and provide understanding of ligand effects on catalyst composition in order to guide development of superior catalyst systems for polymerization of olefins. Our group is designing and synthesizing new “LX2”,“pincer” type ligands and complexing early transition metals to afford precatalysts. In a collaboration with Hans Brintzinger from the University of Konstanz, we are also examining the structures of the components of catalyst systems obtained from reaction of zirconocene dichlorides with aluminum alkyls and aluminum hydrides. Such systems are currently used commercially to produce polyolefins, but the nature of the active and dormant species as well as the mechanisms of their interconversions are not understood. New information on catalyst design and performance may lead to new types of polymers and/or new chemical transformations between hydrocarbons and transition metal centers, ultimately contributing to the development of catalytic reactions for the production of fuels, commodity and polymeric materials.

  12. Hybrid Photonic Cavity with Metal-Organic Framework Coatings for the Ultra-Sensitive Detection of Volatile Organic Compounds with High Immunity to Humidity

    Science.gov (United States)

    Tao, Jifang; Wang, Xuerui; Sun, Tao; Cai, Hong; Wang, Yuxiang; Lin, Tong; Fu, Dongliang; Ting, Lennon Lee Yao; Gu, Yuandong; Zhao, Dan

    2017-01-01

    Detection of volatile organic compounds (VOCs) at parts-per-billion (ppb) level is one of the most challenging tasks for miniature gas sensors because of the high requirement on sensitivity and the possible interference from moisture. Herein, for the first time, we present a novel platform based on a hybrid photonic cavity with metal-organic framework (MOF) coatings for VOCs detection. We have fabricated a compact gas sensor with detection limitation ranging from 29 to 99 ppb for various VOCs including styrene, toluene, benzene, propylene and methanol. Compared to the photonic cavity without coating, the MOF-coated solution exhibits a sensitivity enhancement factor up to 1000. The present results have demonstrated great potential of MOF-coated photonic resonators in miniaturized gas sensing applications.

  13. Oxygen-metal bonding in Ti-bearing compounds from O 1s spectra and ab initio full multiple-scattering calculations

    International Nuclear Information System (INIS)

    Ziyu Wu; Paris, E.; Langenhorst, F.; Seifert, F.

    2002-01-01

    The O K-edge spectra of a series of Ti-bearing compounds with Ti in diffrent structural and chemical environments have been measured using electron energy-loss spectroscopy and analyzed using ab initio full multiple-scattering (MS) calculations. The near-edge structures arise mainly from covalency by direct and/or indirect interaction between O and metal atoms and between O and Si atoms. The coordination number of the cation and the site symmetry also influence the spectral shape and structures. Using different size clusters around the excited atom in the full MS simulation, it is possible to interpret and assign the features present in the spectra of each compund to its specific atomic arrangement and electronic structure. (au)

  14. Diagrams of the variations in the free energy of formation of metallic compounds (1960); Diagrammes de variations d'energie libre de formation des composes metalliques (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Darras, R; Loriers, H [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The variations in the standard free energy {delta}G produced during the formation of the principal simple metallic compounds have been calculated as a function of the temperature from recently published data, and are presented in convenient diagram form. Their usefulness in metallurgy is illustrated by some possible applications. (author) [French] Les variations d'energie libre standard {delta}G intervenant lors de la formation des principaux composes metalliques simples ont ete calculees, en fonction de la temperature, d'apres les donnees recentes de la litterature et rassemblees sous forme de diagrammes d'utilisation commode. Leur interet certain en metallurgie est concretise par quelques exemples d'applications possibles. (auteur)

  15. Biomolecules for Removal of Heavy Metal.

    Science.gov (United States)

    Singh, Namita Ashish

    2017-01-01

    Patents reveal that heavy metals are natural constituents of the earth's crust, but some heavy metals like cadmium, lead, mercury, arsenic etc. are injurious to living organisms at higher concentration. Nowadays, anthropogenic activities have altered geochemical cycles and biochemical balance of heavy metals. Biomolecules are used nowadays for removal of heavy metals compared to other synthetic biosorbents due to their environmental friendly nature and cost effectiveness. The goal of this work is to identify the role of biomolecules like polysaccharides, polypeptides, natural compounds containing aromatic acid etc. for heavy metal removal by bio sorption. It has been observed that efficiency of biomolecules can be increased by functionalization e.g. cellulose functionalization with EDTA, chitosan with sulphur groups, alginate with carboxyl/ hydroxyl group etc. It was found that the porous structure of aerogel beads improves both sorption and kinetic properties of the material. Out of polypeptides metallothionein has been widely used for removal of heavy metal up to 88% from seawater after a single centrifugation. These cost effective functionalized biomolecules are significantly used for remediation of heavy metals by immobilizing these biomolecules onto materials. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.