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Sample records for copper sulfides

  1. Formation of Copper Sulfide Artifacts During Electrolytic Dissolution of Steel

    NASA Astrophysics Data System (ADS)

    Tan, Jia; Pistorius, P. Chris

    2013-06-01

    Based on equilibrium considerations, copper sulfide is not expected to form in manganese-containing steel, yet previous workers reported finding copper sulfide in transmission electron microscope samples which had been prepared by electropolishing. It is proposed that copper sulfide can form during electrolytic dissolution because of the much greater stability of copper sulfide relative to manganese sulfide in contact with an electrolyte containing copper and manganese cations. This mechanism has been demonstrated with aluminum-killed steel samples.

  2. Upper critical field of copper molybdenum sulfide

    NASA Technical Reports Server (NTRS)

    Alterovitz, S. A.; Woollam, J. A.

    1978-01-01

    The upper critical field of sintered and sputtered copper molybdenum sulfide Cu(x)Mo6S8 was measured and found to exceed the Werthamer, Helfand, and Hohenberg (1966) value for a type II superconductor characterized by dirty limit, weak isotropic electron phonon coupling, and no paramagnetic limiting. It is suggested that the enhancement results from anisotropy or clean limit or both. Other ternary molybdenum sulfides appear to show similar anomalies.

  3. Reactively evaporated films of copper molybdenum sulfide

    NASA Technical Reports Server (NTRS)

    Chi, K. C.; Dillon, R. O.; Bunshah, R. F.; Alterovitz, S.; Woollam, J. A.

    1978-01-01

    Films of superconducting Chevrel-phase copper molybdenum sulfide CuxMo6S8 were deposited on sapphire substrates by reactive evaporation using H2S as the reacting gas. Two superconducting temperatures (10.0 K and 5.0 K) of the films were found, corresponding to two different phases with different copper concentrations. All films were superconducting above 4.2 K and contained Chevrel-phase compound as well as free molybdenum. The critical current was measured as a function of applied field. One sample was found to deviate from the scaling law found for co-evaporated or sputtered samples, which possibly indicates a different pinning mechanism or inhomogeneity of the sample.

  4. Copper sulfide solid-state electrolytic memory devices

    NASA Astrophysics Data System (ADS)

    You, Liang

    Copper sulfide thin films with electrical switching and memory effect were grown using a chemical vapor reaction apparatus. The formation of copper sulfide film undergoes a process which includes nucleation, growth of nucleation, coalescence into continuous film, and film thickening. The initial phase of the sulfide growth was reaction limited followed by a diffusion limited phase involving out-diffusion of copper. The thin film tends to nucleate and grow at energy favorable sites such as twinning boundary. Sulfidation of polycrystalline copper results in formation of voids at the interface between the copper and its sulfide. (111) copper has the highest sulfidation rate followed by (100) and (110) copper planes. Moreover, the sulfidation rate near the microfabricated plug edge was found to be faster than the rate at the center of the plug. A mechanism based on competing sulfidation sites due to the geometry difference between the plugs' center and their edge is presented to explain this phenomenon. We show for the first time that field-assisted solid-electrolyte copper sulfide thin film device can function as a switch by reversing the voltage polarity between copper and inert metal electrodes through a copper-sulfide layer in planar and vertical structures. The copper oxide at the top of copper sulfide greatly increased the turn-on voltage. The turn-on voltage depends linearly on the film thickness. Copper sulfide devices in micrometer dimension were microfabricated using IC compatible techniques and characterized showing the same switching effect. Electrode contact area effect on switching performance was investigated in term of turn-on voltage, turn-off voltage, on-state resistance and off-state resistance. Four-point resistance measurement unit, Hall Effect and transfer length measurement were also fabricated together with copper sulfide switching devices and they were studied in order to determine the CuxS carrier type, carrier concentration, film resistivity

  5. Superconducting properties of evaporated copper molybdenum sulfide films

    NASA Technical Reports Server (NTRS)

    Woollam, J. A.; Chi, K. C.; Dillon, R. O.; Bunshah, R. F.; Alterovitz, S. A.

    1978-01-01

    Films of copper molybdenum sulfide were produced by coevaporation. Those that were superconducting contained only the ternary compound and free molybdenum. The range of copper content in the ternary compound was as large as that in polycrystalline material, that is, it includes either phase alone, or a mixture of the two phases of this material. This is in contrast with sputtered materials where copper concentration has been limited to a narrower range. The upper critical field and the critical current were measured as functions of external magnetic field, and found to be similar to those of sputtered copper molybdenum sulfide, when the comparison was made for samples having the same amount of copper.

  6. The cuprex metal extraction process: Recovering copper from sulfide ores

    NASA Astrophysics Data System (ADS)

    Dalton, R. F.; Diaz, G.; Price, R.; Zunkel, A. D.

    1991-08-01

    The Cuprex™ metal extraction process produces cathode-grade copper using a hydrometallurgical process based on chloride leaching of sulfide ore concentrates. The process incorporates several novel steps to overcome the major problems associated with earlier chloride-based processes, including mild leaching conditions using ferric chloride as leachant and solvent extraction of copper usinga novel reagent. This produces a highly concentrated cupric chloride electrolyte from which cathode-grade copper is electrowon in the Metclor cell. The technical viability and robustness of the core technology have been proven in a series of large-scale pilot trials. More recent work has concentrated on supplementary processes to convert the copper powder product to an article of commerce and to recover valuable by-products. A fully integrated scheme is now being developed with updated cost estimates.

  7. Fabrication and applications of copper sulfide (CuS) nanostructures

    NASA Astrophysics Data System (ADS)

    Shamraiz, Umair; Hussain, Raja Azadar; Badshah, Amin

    2016-06-01

    This review article presents different fabrication procedures (under the headlines of solvothermal routes, aerosol methods, solution methods and thermolysis), and applications (photocatalytic degradation, ablation of cancer cells, electrode material in lithium ion batteries and in gas sensing, organic solar cells, field emission properties, super capacitor applications, photoelectrochemical performance of QDSCs, photocatalytic reduction of organic pollutants, electrochemical bio sensing, enhanced PEC characteristics of pre-annealed CuS film electrodes) of copper sulfide (Covellite).

  8. A facile synthesis of copper sulfides composite with lithium-storage properties

    NASA Astrophysics Data System (ADS)

    Wang, Xuxiang; Wang, Yunhui; Li, Xue; Liu, Bo; Zhao, Jinbao

    2015-05-01

    Copper sulfides are synthesized by heating a mixture of copper and sulfur powders in different stoichiometries in N-methyl-2-pyrrolidinone (NMP) solvent. All the electrodes show excellent electrochemical performance, especially 'copper excess' copper sulfides electrodes. These electrodes can be charged and discharged at high rate, with good capacity retention. The electrochemical reaction mechanism of copper sulfides during discharge-charge process is investigated. It is most likely that all of S element in the copper excess electrode would transfer into a crystal of Cu2S during charge-discharge cycles, which corresponded to a single electrochemical reaction and showed excellent cycling and rate performance. These encouraging results indicate that copper-excess copper sulfides could be a promising anode material for lithium batteries with high rate capability.

  9. Multi-dimensional modeling of atmospheric copper-sulfidation corrosion on non-planar substrates.

    SciTech Connect

    Chen, Ken Shuang

    2004-11-01

    This report documents the author's efforts in the deterministic modeling of copper-sulfidation corrosion on non-planar substrates such as diodes and electrical connectors. A new framework based on Goma was developed for multi-dimensional modeling of atmospheric copper-sulfidation corrosion on non-planar substrates. In this framework, the moving sulfidation front is explicitly tracked by treating the finite-element mesh as a pseudo solid with an arbitrary Lagrangian-Eulerian formulation and repeatedly performing re-meshing using CUBIT and re-mapping using MAPVAR. Three one-dimensional studies were performed for verifying the framework in asymptotic regimes. Limited model validation was also carried out by comparing computed copper-sulfide thickness with experimental data. The framework was first demonstrated in modeling one-dimensional copper sulfidation with charge separation. It was found that both the thickness of the space-charge layers and the electrical potential at the sulfidation surface decrease rapidly as the Cu{sub 2}S layer thickens initially but eventually reach equilibrium values as Cu{sub 2}S layer becomes sufficiently thick; it was also found that electroneutrality is a reasonable approximation and that the electro-migration flux may be estimated by using the equilibrium potential difference between the sulfidation and annihilation surfaces when the Cu{sub 2}S layer is sufficiently thick. The framework was then employed to model copper sulfidation in the solid-state-diffusion controlled regime (i.e. stage II sulfidation) on a prototypical diode until a continuous Cu{sub 2}S film was formed on the diode surface. The framework was also applied to model copper sulfidation on an intermittent electrical contact between a gold-plated copper pin and gold-plated copper pad; the presence of Cu{sub 2}S was found to raise the effective electrical resistance drastically. Lastly, future research needs in modeling atmospheric copper sulfidation are discussed.

  10. Aqueous synthesis of PEGylated copper sulfide nanoparticles for photoacoustic imaging of tumors

    NASA Astrophysics Data System (ADS)

    Ding, Ke; Zeng, Jianfeng; Jing, Lihong; Qiao, Ruirui; Liu, Chunyan; Jiao, Mingxia; Li, Zhen; Gao, Mingyuan

    2015-06-01

    By integrating high imaging sensitivity and high resolution in a single modality, photoacoustic (PA) imaging emerges as a promising diagnostic tool for clinical applications. Benefiting from the absorption in the near-infrared region (NIR), copper sulfide nanoparticles (NPs) as a contrast agent are potentially useful for increasing the sensitivity of PA imaging. However, the aqueous synthesis of size-tunable, biocompatible and colloidally stable copper sulfide NPs remains challenging due to the intrinsic dipole-dipole interactions among particles. In this work, aqueous synthesis of PEGylated copper sulfide NPs with controllable size between 3 and 7 nm was developed. The particle size-dependent contrast enhancement effect of the copper sulfide NPs for PA imaging was carefully studied both in vitro and in vivo. Although the contrast enhancement effect of the copper sulfide NPs is proportional to particle size, the in vivo studies revealed that copper sulfide NPs smaller than 5 nm presented higher tumor imaging performance, especially at the tumor boundary site, which was further discussed in combination with the pharmacokinetic behaviors of differently sized particles.By integrating high imaging sensitivity and high resolution in a single modality, photoacoustic (PA) imaging emerges as a promising diagnostic tool for clinical applications. Benefiting from the absorption in the near-infrared region (NIR), copper sulfide nanoparticles (NPs) as a contrast agent are potentially useful for increasing the sensitivity of PA imaging. However, the aqueous synthesis of size-tunable, biocompatible and colloidally stable copper sulfide NPs remains challenging due to the intrinsic dipole-dipole interactions among particles. In this work, aqueous synthesis of PEGylated copper sulfide NPs with controllable size between 3 and 7 nm was developed. The particle size-dependent contrast enhancement effect of the copper sulfide NPs for PA imaging was carefully studied both in vitro and in

  11. Electrically Conducting Polymer-Copper Sulphide Composite Films, Preparation by Treatment of Polymer-Copper (2) Acetate Composites with Hydrogen Sulfide

    NASA Technical Reports Server (NTRS)

    Yamamoto, Takakazu; Kamigaki, Takahira; Kubota, Etsuo

    1988-01-01

    Polymer copper sulfide composite films were prepared by treatment of polymer poly(vinyl chloride), poly(acrylonitrile), copolymer of vinyl chloride and vinyl acetate (90:10), and ABS resin copper (2) acetate composites with hydrogen sulfide. The films showed electrical conductivity higher than 0.015 S/cm when they contained more than 20 wt percent of copper sulfide. A poly(acrylonitrile)-copper sulfide composite film containing 40 to 50 wt percent of copper sulfide showed electrical conductivity of 10 to 150.0 S/cm and had relatively high mechanical strength to be used in practical purposes.

  12. Beneficiation of flotation tailing from Polish copper sulfide ores

    SciTech Connect

    Luszczkiewicz, A.; Sztaba, K.S.

    1995-12-31

    Flotation tailing of Polish copper sulfide ores represents more than 90% of the mass of run-of-mine ore. The tailing contains mainly quartz, dolomite, clay minerals, traces of sulfides, and some accessory minerals. Almost all minerals of the tailing are well liberated and, therefore, any further beneficiation process applied to the tailing is expected to be inexpensive. In this work, results of investigations on utilization of flotation tailing using classification and gravity concentration are presented. It is shown that due to classification of flotation tailing in hydrocyclones, the coarse fraction becomes suitable material for gravity separation providing backfill material for underground mines as well as heavy minerals, a source of valuable rare elements. It was also found that heavy minerals separated by gravity methods contain a significant amount of rare elements such as zirconium, titanium, silver, rare earth metals, and uranium. The light fraction of the gravity separation contains well deslimed quartz particles and meets strict requirements for hydraulic filling material used for structural support in underground mines. Evaluation of the cost of the proposed technology indicated that investment to implement the method would provide a return within 2--4 years.

  13. Plasmonic copper sulfide nanocrystals exhibiting near-infrared photothermal and photodynamic therapeutic effects.

    PubMed

    Wang, Shunhao; Riedinger, Andreas; Li, Hongbo; Fu, Changhui; Liu, Huiyu; Li, Linlin; Liu, Tianlong; Tan, Longfei; Barthel, Markus J; Pugliese, Giammarino; De Donato, Francesco; Scotto D'Abbusco, Marco; Meng, Xianwei; Manna, Liberato; Meng, Huan; Pellegrino, Teresa

    2015-02-24

    Recently, plasmonic copper sulfide (Cu2-xS) nanocrystals (NCs) have attracted much attention as materials for photothermal therapy (PTT). Previous reports have correlated photoinduced cell death to the photothermal heat mechanism of these NCs, and no evidence of their photodynamic properties has been reported yet. Herein we have prepared physiologically stable near-infrared (NIR) plasmonic copper sulfide NCs and analyzed their photothermal and photodynamic properties, including therapeutic potential in cultured melanoma cells and a murine melanoma model. Interestingly, we observe that, besides a high PTT efficacy, these copper sulfide NCs additionally possess intrinsic NIR induced photodynamic activity, whereupon they generate high levels of reactive oxygen species. Furthermore, in vitro and in vivo acute toxic responses of copper sulfide NCs were also elicited. This study highlights a mechanism of NIR light induced cancer therapy, which could pave the way toward more effective nanotherapeutics. PMID:25603353

  14. VAPOR PHASE MERCURY SORPTION BY ORGANIC SULFIDE MODIFIED BIMETALLIC IRON-COPPER NANOPARTICLE AGGREGATES

    EPA Science Inventory

    Novel organic sulfide modified bimetallic iron-copper nanoparticle aggregate sorbent materials have been synthesized for removing elemental mercury from vapor streams at elevated temperatures (120-140 °C). Silane based (disulfide silane and tetrasulfide silane) and alkyl sulfide ...

  15. Effect of anions on selective solubilization of zinc and copper in bacterial leaching of sulfide ores.

    PubMed

    Harahuc, L; Lizama, H M; Suzuki, I

    2000-07-20

    Bacterial leaching of sulfide ores using Thiobacillus ferrooxidans, Thiobacillus thiooxidans, or a combination of the two was studied at various concentrations of specific anions. Selective zinc and copper solubilization was obtained by inhibiting iron oxidation without affecting sulfur/sulfide oxidation. Phosphate reduced iron solubilization from a pyrite (FeS(2))-sphalerite (ZnS) mixture without significantly affecting zinc solubilization. Copper leaching from a chalcopyrite (CuFeS(2))-sphalerite mixture was stimulated by phosphate, whereas chloride accelerated zinc extraction. In a complex sulfide ore containing pyrite, chalcopyrite, and sphalerite, both phosphate and chloride reduced iron solubilization and increased copper extraction, whereas only chloride stimulated zinc extraction. Maximum leaching obtained was 100% zinc and 50% copper. Time-course studies of copper and zinc solubilization suggest the possibility of selective metal recovery following treatment with specific anions. PMID:10861398

  16. Hollow Copper Sulfide Nanoparticle-Mediated Transdermal Drug Delivery

    PubMed Central

    Ramadan, Samy; Guo, Liangran; Li, Yajuan; Yan, Bingfang; Lu, Wei

    2012-01-01

    Nanoparticles with strong optical absorption at near-infrared (NIR) wavelengths can efficiently convert optical energy into thermal energy, and have shown multimodality in biological and biomedical applications. In this work, a new type of thermal ablation-enhanced transdermal delivery methodology is developed based on hollow copper sulfide nanoparticles (HCuSNPs) with intense photothermal coupling effects. Application of nanosecond-pulsed NIR laser allows rapid heating of the nanoparticles and instantaneous heat conduction. This provides very short periods of time but extremely high temperatures (estimated over 100°C) in local regions, with focused thermal ablation of the stratum corneum. Because the discontinuous light from the pulsed laser minimized heat accumulation, the average temperature of the irradiated skin area only increases to ~40–50°C. The extent of thermal ablation of skin, i.e. removal of the stratum corneum, viable epidermis, or the dermis, can be controlled by adjusting the laser power. The skin disruption by HCuSNP-mediated photothermal ablation significantly increases the permeability of macromolecule drugs such as human growth hormone, providing effective and controlled percutaneous delivery. This technique offers compelling opportunities to overcome low oral bioavailability of small- and large-molecular-weight drugs, avoiding the pain and inconvenience of long-term s.c. injections while enabling sustained and controlled delivery. PMID:22829400

  17. Crystal structure controlled synthesis and characterization of copper sulfide nanoparticles

    NASA Astrophysics Data System (ADS)

    Senthilkumar, M.; Babu, S. Moorthy

    2016-05-01

    Phase pure, controlled crystal structure of digenite (Cu9S5) copper sulfide nanoparticles were synthesized by hot injection method at the temperature of 180°C. The mixture of Oleylamine, 1-Octadecene and 1-Dodecanethiol were taken as solvent as well as capping agents. The effect of the mixture of solvents on the phase formation and morphology of the synthesized nanoparticles were analysed. The nanocrystals were characterized using X-Ray diffraction (XRD) which confirms the presence of single phase rhombohedral digenite Cu9S5 NPs, Morphological analysis clearly depicts the formation of hexagonal faceted Cu9S5 NPs, Energy dispersive X-ray absorption spectroscopy (EDS) reveals the stoichiometric ratio of 1.8:1 for synthesized NPs. From the UV-Vis absorption spectroscopy the bandgap value of Cu1.8S is found to be 1.71 eV. The presence of capping agents along the surface of the Cu9S5 NPs was confirmed from FTIR analysis.

  18. VAPOR PHASE MERCURY SORPTION BY ORGANIC-SULFIDE COATED BIMETALLIC IRON-COPPER NANOPARTICLE AGGREGATES

    EPA Science Inventory

    Tetra sulfide silane coated iron-copper nano-particle aggregates are found to be potentially very high capacity sorbents for vapor phase mercury capture. High equilibrium capacities were obtained for the silane coated iron copper nano-aggregate sorbent at 70 oC and 120 oC. Even a...

  19. Phage-directed synthesis of copper sulfide: structural and optical characterization

    NASA Astrophysics Data System (ADS)

    Shahriar Zaman, Mohammed; Moon, Chung Hee; Bozhilov, Krassimir N.; Haberer, Elaine D.

    2013-08-01

    The growth of crystalline copper sulfide using a viral template was investigated using sequential incubation in CuCl2 and Na2S precursors. Non-specific electrostatic attraction between a genetically-modified M13 bacteriophage and copper cations in the CuCl2 precursor caused phage agglomeration and bundle formation. Following the addition of Na2S, polydisperse nanocrystals 2-7 nm in size were found along the length of the viral scaffold. The structure of the copper sulfide material was identified as cubic anti-fluorite type Cu1.8S, space group F m\\bar {3}m. Strong interband absorption was observed within the ultraviolet to visible range with an onset near 800 nm. Furthermore, free carrier absorption, associated with the localized surface plasmon resonance of the copper sulfide nanocrystals, was seen in the near infrared with absorbance maxima at 1060 nm and 3000 nm, respectively.

  20. From Ultrafine Thiolate-Capped Copper Nanoclusters toward Copper Sulfide Nanodiscs: A Thermally Activated Evolution Route

    SciTech Connect

    Mott, Derrick; Yin, Jun; Engelhard, Mark H.; Loukrakpam, Rameshwori; Chang, Paul; Miller, George; Bae, In-Tae; Das, N. C.; Wang, Chong M.; Luo, Jin; Zhong, Chuan-Jian

    2010-01-12

    In this report we show that the size, shape, and composition of pre-synthesized metal nanoparticles can be engineered through exploiting concurrent interparticle coalescence and interfacial copper-thiolate cleavage under a thermally-activated evolution process. This concept is demonstrated by thermally-activated processing of ultrafine (~0.5 nm) copper nanoparticles encapsulated with thiolate monolayer (Cun(SR)m) toward copper sulfide nanodiscs with controllable sizes and shapes. It involved a thermally-activated coalescence of Cun(SR)m nanoclusters accompanied by interfacial Cu-S cleavage towards the formation of Cu2S nanocrystals with well-defined nanodisc shapes with an average diameter and thickness ranging from 10.7 ±1.4 nm and 5.5 ±0.5 nm (aspect ratio ~2) to 31.2 ±4.3 nm and 3.9 ±0.4 nm (aspect ratio ~7) depending on the thermal processing parameters. These nanodiscs are stable and display remarkable ordering upon self-assembly. The abilities to create the ultrafine copper nanoclusters and to enable them to undergo a thermally-activated coalescence and a concurrent Cu-S bond cleavage toward the formation of Cu2S nanodiscs is entirely new. The viability of fine tuning the size and shape of the Cu2S nanocrystals by controlling the relative binding strength of thiolates, the C-S cleavage reactivity, and the interparticle coalescence activity, and their potential applications in electronic, sensing and photochemical devices are also discussed.

  1. Sonochemical preparation of copper sulfides with different phases in aqueous solutions

    SciTech Connect

    Kristl, Matjaž; Hojnik, Nuša; Gyergyek, Sašo; Drofenik, Miha

    2013-03-15

    Highlights: ► Sonochemical preparation of copper sulfides in aqueous solutions is reported. ► CuS and Cu{sub 2}S nanoparticles with crystallite sizes between 7 and 18 nm were obtained. ► Crystallite size can be changed using different complexing agents. ► Thermal behavior was studied by TG and XRD measurements. - Abstract: There is a growing interest in the synthesis of nanostructured copper sulfides due to their ability to form compounds with various stoichiometries. We report a sonochemical route for the preparation of copper sulfides with different compositions in aqueous solutions, using different, general and convenient copper sources such as copper acetate, copper hydroxide or basic copper carbonate and thiourea or thioacetamide as sulfur precursors under ambient air. Phase analysis, purity and morphology of the products were studied by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The results revealed that nanoparticles of covellite, CuS, with crystallite sizes between 7 and 18 nm can be obtained by using different precursors and complexing agents and that chalcocite, Cu{sub 2}S, can also be prepared sonochemically.

  2. Analytical modeling of localized surface plasmon resonance in heterostructure copper sulfide nanocrystals

    SciTech Connect

    Caldwell, Andrew H.; Ha, Don-Hyung; Robinson, Richard D.; Ding, Xiaoyue

    2014-10-28

    Localized surface plasmon resonance (LSPR) in semiconductor nanocrystals is a relatively new field of investigation that promises greater tunability of plasmonic properties compared to metal nanoparticles. A novel process by which the LSPR in semiconductor nanocrystals can be altered is through heterostructure formation arising from solution-based cation exchange. Herein, we describe the development of an analytical model of LSPR in heterostructure copper sulfide-zinc sulfide nanocrystals synthesized via a cation exchange reaction between copper sulfide (Cu{sub 1.81}S) nanocrystals and Zn ions. The cation exchange reaction produces dual-interface, heterostructure nanocrystals in which the geometry of the copper sulfide phase can be tuned from a sphere to a thin disk separating symmetrically-grown sulfide (ZnS) grains. Drude model electronic conduction and Mie-Gans theory are applied to describe how the LSPR wavelength changes during cation exchange, taking into account the morphology evolution and changes to the local permittivity. The results of the modeling indicate that the presence of the ZnS grains has a significant effect on the out-of-plane LSPR mode. By comparing the results of the model to previous studies on solid-solid phase transformations of copper sulfide in these nanocrystals during cation exchange, we show that the carrier concentration is independent of the copper vacancy concentration dictated by its atomic phase. The evolution of the effective carrier concentration calculated from the model suggests that the out-of-plane resonance mode is dominant. The classical model was compared to a simplified quantum mechanical model which suggested that quantum mechanical effects become significant when the characteristic size is less than ∼8 nm. Overall, we find that the analytical models are not accurate for these heterostructured semiconductor nanocrystals, indicating the need for new model development for this emerging field.

  3. The effects of varying humidity on copper sulfide film formation.

    SciTech Connect

    Mayer, Thomas Michael; Missert, Nancy A.; Barbour, John Charles; Sullivan, John Patrick; Copeland, Robert Guild; Campin, Michael J.

    2004-02-01

    Detailed experiments involving extensive high resolution transmission electron microscopy (TEM) revealed significant microstructural differences between Cu sulfides formed at low and high relative humidity (RH). It was known from prior experiments that the sulfide grows linearly with time at low RH up to a sulfide thickness approaching or exceeding one micron, while the sulfide initially grows linearly with time at high RH then becomes sub-linear at a sulfide thickness less than about 0.2 microns, with the sulfidation rate eventually approaching zero. TEM measurements of the Cu2S morphology revealed that the Cu2S formed at low RH has large sized grains (75 to greater than 150 nm) that are columnar in structure with sharp, abrupt grain boundaries. In contrast, the Cu2S formed at high RH has small equiaxed grains of 20 to 50 nm in size. Importantly, the small grains formed at high RH have highly disordered grain boundaries with a high concentration of nano-voids. Two-dimensional diffusion modeling was performed to determine whether the existence of localized source terms at the Cu/Cu2S interface could be responsible for the suppression of Cu sulfidation at long times at high RH. The models indicated that the existence of static localized source terms would not predict the complete suppression of growth that was observed. Instead, the models suggest that the diffusion of Cu through Cu2S becomes restricted during Cu2S formation at high RH. The leading speculation is that the extensive voiding that exists at grain boundaries in this material greatly reduces the flux of Cu between grains, leading to a reduction in the rate of sulfide film formation. These experiments provide an approach for adding microstructural information to Cu sulfidation rate computer models. In addition to the microstructural studies, new micro-patterned test structures were developed in this LDRD to offer insight into the point defect structure of Cu2S and to permit measurement of surface reaction

  4. Kinetics of Copper Removal from Sulfidized Molybdenite Concentrates by Pressure Leaching

    NASA Astrophysics Data System (ADS)

    Padilla, Rafael; Opazo, Cristian; Ruiz, Maria C.

    2015-02-01

    Molybdenite concentrates produced from porphyry copper deposits contain copper as an impurity in variable quantities. To produce a high-grade molybdenite concentrate, a chemical purification method is normally practiced. In this paper, a new alternative for the copper elimination from molybdenite concentrates containing chalcopyrite by sulfidation of the molybdenite concentrate and subsequent pressure leaching in sulfuric acid-oxygen media is discussed. The results indicated that copper contained in sulfidized molybdenite concentrates can be dissolved effectively by pressure leaching at low temperature ranging from 373 K to 423 K (100 °C to 150 °C) and low oxygen pressure (303.98 to 1013.25 kPa) with negligible dissolution of molybdenum. The final molybdenite contained less than 0.2 pct Cu which is appropriate for marketing. Temperature and oxygen partial pressure have both significant influence on the copper dissolution. The kinetics of the copper dissolution was analyzed using the shrinking core model with surface chemical control. The calculated activation energy was 51 kJ/mol in the range of 373 K to 423 K (100 °C to 150 °C). The copper dissolution rate is of zero order with respect to hydrogen ion concentration, and first order with respect to oxygen partial pressure.

  5. Recovery of cobalt and copper from complex sulfide concentrates

    SciTech Connect

    Dannenberg, R.O.; Gardner, P.C.; Crane, S.R.; Seidel, D.C.

    1987-01-01

    The Bureau conducted bench-scale research on a process for treating cobaltite concentrates, comprising (1) oxidative pressure leaching, (2) jarosite precipitation followed by H/sub 2/O/sub 2/ oxidation and pH control to remove iron and arsenic, (3) copper solvent extraction with a mixed hydroxyoxime-amine extractant, (4) copper electrowinning from recirculating acidic strip liquor, (5) selective cobalt extraction from copper solvent extraction raffinate with a phosphinic and extractant, and (6) electrowinning of cobalt from a recirculating weak acid strip liquor. Overall cobalt and copper recoveries were 91.7 and 84.1 pct, respectively. Electrowon products assayed 99.8 pct Co and 99.89 ct Cu.

  6. Solid-solid phase transformations induced through cation exchange and strain in 2D heterostructured copper sulfide nanocrystals.

    PubMed

    Ha, Don-Hyung; Caldwell, Andrew H; Ward, Matthew J; Honrao, Shreyas; Mathew, Kiran; Hovden, Robert; Koker, Margaret K A; Muller, David A; Hennig, Richard G; Robinson, Richard D

    2014-12-10

    We demonstrate dual interface formation in nanocrystals (NCs) through cation exchange, creating epitaxial heterostructures within spherical NCs. The thickness of the inner-disk layer can be tuned to form two-dimensional (2D), single atomic layers (<1 nm). During the cation exchange reaction from copper sulfide to zinc sulfide (ZnS), we observe a solid-solid phase transformation of the copper sulfide phase in heterostructured NCs. As the cation exchange reaction is initiated, Cu ions replaced by Zn ions at the interfaces are accommodated in intrinsic Cu vacancy sites present in the initial roxbyite (Cu1.81S) phase of copper sulfide, inducing a full phase transition to djurleite (Cu1.94S)/low chalcocite (Cu2S), a more thermodynamically stable phase than roxbyite. As the reaction proceeds and reduces the size of the copper sulfide layer, the epitaxial strain at the interfaces between copper sulfide and ZnS increases and is maximized for a copper sulfide disk ∼ 5 nm thick. To minimize this strain energy, a second phase transformation occurs back to the roxbyite phase, which shares a similar sulfur sublattice to wurtzite ZnS. The observation of a solid-solid phase transformation in our unique heterostructured NCs provides a new pathway to control desired phases and an insight into the influence of cation exchange on nanoscale phase transitions in heterostructured materials. PMID:25337657

  7. Thermochemical chlorination of carbon indirectly driven by an unexpected sulfide of copper with inorganic chloride.

    PubMed

    Fujimori, Takashi; Takaoka, Masaki

    2011-12-15

    Unintentional anthropogenic thermal chlorination of carbon is known to be a contributor to global environmental pollution of organochlorine compounds. We found unexpected, serious chlorination of carbon promoted by a "sulfide" of copper, which has been generally thought of and studied as an inactive metal catalyst. Our quantitative and X-ray spectroscopic results show that a fraction of cupric sulfide indirectly promoted thermochemical solid-phase formation of a large quantity of organochlorine compounds such as polychlorinated dibenzo-p-dioxins, dibenzofurans, biphenyls, and benzenes that used inactive inorganic chloride as chlorine storage, which partly caused environmental pollution by organochlorine compounds. PMID:22004834

  8. Removal of copper from carbon-saturated iron with an aluminum sulfide ferrous sulfide flux.

    SciTech Connect

    Cohen, A.; Blander, M.; Energy Technology

    1998-04-01

    Scrap iron and steel have long been considered as resources in the steelmaking industry, and their value is largely determined by the impurity content. Copper is a particularly troublesome impurity because of its role in causing hot shortness and should be kept below ==0.1 wt pct. A method for reducing copper content in steel to <0.1 wt pct could lead to increased use of lower-quality scrap.

  9. Banded sulfide-magnetite ores of Mauk copper massive sulfide deposit, Central Urals: Composition and genesis

    NASA Astrophysics Data System (ADS)

    Safina, N. P.; Maslennikov, V. V.; Maslennikova, S. P.; Kotlyarov, V. A.; Danyushevsky, L. V.; Large, R. R.; Blinov, I. A.

    2015-05-01

    The results of investigation of metamorphosed sulfide-magnetite ores from the Mauk deposit located within the Main Ural Fault at the junction of Tagil and Magnitogorsk massive sulfide zones are discussed. The ore-hosting sequence comprises metamorphic rocks formed from basalt, carbonaceous and carbonaceous-cherty siltstone, and lenticular serpentinized ultramafic bodies. The ores of the deposit are represented by banded varieties and less frequent breccia. The clastic origin of the banded ore is indicated by load casts at the bottom of sulfide beds, alternation of sulfide and barren beds, and the truncation of the growth zones of pyrite crystals. Pyrite, pyrrhotite, chalcopyrite, sphalerite, and magnetite are the major minerals of the banded ores. The internal structure of the listed minerals testifies to the deep metamorphic recrystallization of primary hydrothermal-sedimentary ores accompanied with deformation. Cubanite, pyrrhotite, mackinawite, greigite, and gold are enclosed in metacrysts of pyrite, magnetite, and chalcopyrite. The accessory minerals of the Pb-Bi-Te, Bi-Te, and Ag-Te systems as well as uraninite have been found at the Mauk deposit for the first time. Magnetite predominantly replaces pyrite and less frequently chalcopyrite, pyrrhotite, and gangue minerals. It was established that the major carriers of As and Co are crystals of metamorphic pyrite. Chalcopyrite is the major carrier of Zn, Sn, Te, Pb, Bi, and Ag. Admixture of Fe and Cu is typical of sphalerite, and Se and Ni are characteristic of pyrrhotite. Ti, V, Mn, Sb, As, Ba, and U are concentrated in magnetite. The banded ores of the Mauk deposit are suggested as having been transformed in several stages: diagenesis, anadiagenesis, epidiagenesis ( t < 300°C), and amphibolite facies metamorphism ( t > 500°C).

  10. Porous copper zinc tin sulfide thin film as photocathode for double junction photoelectrochemical solar cells.

    PubMed

    Dai, Pengcheng; Zhang, Guan; Chen, Yuncheng; Jiang, Hechun; Feng, Zhenyu; Lin, Zhaojun; Zhan, Jinhua

    2012-03-21

    Porous copper zinc tin sulfide (CZTS) thin film was prepared via a solvothermal approach. Compared with conventional dye-sensitized solar cells (DSSCs), double junction photoelectrochemical cells using dye-sensitized n-type TiO(2) (DS-TiO(2)) as the photoanode and porous p-type CZTS film as the photocathode shows an increased short circuit current, external quantum efficiency and power conversion efficiency. PMID:22322239

  11. Copper isotopic signature of the Tiegelongnan high-sulfidation copper deposit, Tibet: implications for its origin and mineral exploration

    NASA Astrophysics Data System (ADS)

    Duan, Jilin; Tang, Juxing; Li, Yubin; Liu, Sheng-Ao; Wang, Qin; Yang, Chao; Wang, Yiyun

    2016-06-01

    We report the copper isotopic composition of Cu sulfides in the Tiegelongnan high-sulfidation (HS) copper deposit, Tibet, and investigate the possible application of Cu isotopes to mineral exploration. The copper isotopic values of samples from four drill holes display consistent progressive increase with depth to 400 m below surface, with an overall variation of δ65Cu of up to 7.60‰ (-4.76 to 2.84‰). Such a large range is very different from that observed in Cu porphyry deposits which commonly exhibit a small δ65Cu range (<1‰), with decreasing values with depth. The large δ65Cu variation is likely of supergene origin and reflects strong leaching under oxidized conditions. The systematic increase of δ65Cu with depth can be explained by the release of isotopically heavy Cu at the top and its transport downward, which is supported by the coupling of positive δ65Cu values with high Cu grade and the occurrence of both negative and positive δ65Cu values in two drill holes. Mass-balance consideration on the basis of Cu isotopes can indicate mineralized zones which have been eroded or have not been found yet. Such mineralized targets, if buried at depth, could be located using Cu isotopes.

  12. Copper isotopic signature of the Tiegelongnan high-sulfidation copper deposit, Tibet: implications for its origin and mineral exploration

    NASA Astrophysics Data System (ADS)

    Duan, Jilin; Tang, Juxing; Li, Yubin; Liu, Sheng-Ao; Wang, Qin; Yang, Chao; Wang, Yiyun

    2015-12-01

    We report the copper isotopic composition of Cu sulfides in the Tiegelongnan high-sulfidation (HS) copper deposit, Tibet, and investigate the possible application of Cu isotopes to mineral exploration. The copper isotopic values of samples from four drill holes display consistent progressive increase with depth to 400 m below surface, with an overall variation of δ65Cu of up to 7.60‰ (-4.76 to 2.84‰). Such a large range is very different from that observed in Cu porphyry deposits which commonly exhibit a small δ65Cu range (<1‰), with decreasing values with depth. The large δ65Cu variation is likely of supergene origin and reflects strong leaching under oxidized conditions. The systematic increase of δ65Cu with depth can be explained by the release of isotopically heavy Cu at the top and its transport downward, which is supported by the coupling of positive δ65Cu values with high Cu grade and the occurrence of both negative and positive δ65Cu values in two drill holes. Mass-balance consideration on the basis of Cu isotopes can indicate mineralized zones which have been eroded or have not been found yet. Such mineralized targets, if buried at depth, could be located using Cu isotopes.

  13. New Measurements of the Densities of Copper, Nickel, and Iron Sulfide Liquids

    NASA Astrophysics Data System (ADS)

    Mioduszewski, L.; Kress, V. C.

    2005-12-01

    Density measurements of sulfide liquids in the Fe-Ni-Cu-S-O system were performed from 1150°C-1250°C under controlled oxygen and sulfur fugacities. Measurements were made using the modified single bob (MSB) Archimedean method using zirconia ceramic bobs and crucibles. A 0.005mm resolution micrometer was attached to an elevator, which raised the crucible and melt relative to the free-hanging, stationary bob. A 0.001 g resolution analytical balance connected to a laptop computer continuously recorded the buoyancy as a function of crucible elevation. Densities were calculated by converting elevation to immersed volume and regressing the slope of buoyancy versus volume immersed. log(fO2) in the experiments ranged from -7.8 to -12.6 and log(fS2) ranged from -0.9 to -3.3. 38 successful sulfide liquid density measurements were performed, with values ranging from 3.8 g/cc to 6.6 g/cc. Regression of the resulting data suggests that a simple linear volume mixing model is adequate to represent the compositional dependence of density in copper- and nickel-sulfide liquids. A moderate positive excess mixing volume appears to be justified in iron-sulfide liquids. This result, along with high derived partial molar volumes for oxygen and sulfur components, are qualitatively consistent with the suggestion that increasing pressure will partition oxygen and sulfur out of the sulfide liquid during planetary accretion. The MSB density measurement also provides information on the relative magnitude of gas-zirconia and sulfide-zirconia surface energies. Assuming most of the observed variation results from sulfide chemistry it appears that oxidizing conditions significantly decrease sulfide-zirconia surface energies (increase wetting). If we can extrapolate this result to silicate minerals, this would suggest that oxidizing conditions will decrease wetting angle and thus increase the potential for sulfide segregation during planetary formation. We hope to test this hypothesis soon. Our

  14. Living cells imaging for copper and hydrogen sulfide by a selective "on-off-on" fluorescent probe.

    PubMed

    Qian, Yong; Lin, Jie; Liu, Tianbao; Zhu, Hailiang

    2015-01-01

    A novel highly selective and sensitive fluorescent probe (NJ1) had been designed and synthesized for Cu(2+) detection by fluorescence quenching mechanism, and then the enhancement of fluorescence intensity with the addition of hydrogen sulfide in complex NJ1Cu aqueous solution at physiological conditions were described. This "on-off-on" type fluorescence recognition system was a reversible process, which could be utilized to monitor copper ion and hydrogen sulfide based on a complex NJ1Cu formation-Cu(2+) displacement approach. Importantly, this real-time recognition process of Cu(2+) and hydrogen sulfide exhibited excellent anti-interference ability. In addition, this new fluorescent probe also has potential utility for Cu(2+) and hydrogen sulfide detection in living cells, providing a potential tool for investigating copper ion and hydrogen sulfide in living systems or environment. PMID:25476371

  15. Characterization of the molecular structure at modified polymer surfaces and polyphenylene sulfide/copper interphases

    SciTech Connect

    Webster, H.F. II.

    1992-01-01

    This research focused on the use of infrared reflection absorption spectroscopy (IRRAS) and x-ray photoelectron spectroscopy (XPS) to investigate the molecular structure of modified and unmodified thin films. The optical constants of polyphenylene sulfide (PPS) were determined and exact optical theory was utilized to simulate spectra for a variety of reflectance techniques. The surface modification of polystyrene, polyphenylene sulfide, and poly(arylene ether) phosphine oxides was also examined. A new technique, variable temperature reflection absorption spectroscopy (VTRAS) was developed as a method to investigate the reorganization of thin PPS films on a variety of substrates. Both the crystallization and melting temperatures could be determined for quenched coatings on a variety of substrates. While degradation under vacuum was not observed on chromium and aluminum surfaces, PPS films on the original ordered state after exposure to temperatures near 300[degrees]C. Spin coated films of polyetherimide were shown to be oriented after spin coating, and the relaxation to a more random state could also be observed by the VTRAS technique. Degradation of PPS films in air was examined and the diffusion of copper species into the bulk of the film with the formation of copper carboxylates was observed. Bonded PPS/copper laminates were investigated and the particular surface chemistry was crucial in determining the peel strength observed. Chemical oxidation with alkaline persulfate solutions resulted in a needle-like surface oxide morphology, and bond strengths were increased by this pretreatment method. The formation of excess cuprous sulfide at the interface was the most probable cause of poor adhesion in these systems. Foil pretreatment by thermal oxidation gave the highest peel strength, and exhibited the lowest amount of interfacial cuprous sulfide.

  16. Grain-to-Grain Compositional Variations and Phase Segregation in Copper-Zinc-Tin-Sulfide Films.

    PubMed

    Alvarez Barragan, Alejandro; Malekpour, Hoda; Exarhos, Stephen; Balandin, Alexander A; Mangolini, Lorenzo

    2016-09-01

    We have performed a rigorous investigation of the structure and composition of individual grains in copper-zinc-tin-sulfide (CZTS) films realized by sulfurization of a sputtered metal stack. Although on average close to the ideal CZTS stoichiometry, elemental analysis shows significant grain-to-grain variations in composition. High-resolution Raman spectroscopy indicates that this is accompanied by grain-to-grain structural variations as well. The intensity from the 337 cm(-1) Raman peak, generally assigned to the kesterite phase of CZTS, remains constant over a large area of the sample. On the other hand, signals from secondary phases at 376 cm(-1) (copper-tin-sulfide) and 351 cm(-1) (zinc-sulfide) show significant variation over the same area. These results confirm the great complexity inherent to this material system. Moreover, structural and compositional variations are recognized in the literature as a factor limiting the efficiency of CZTS photovoltaic devices. This study demonstrates how a seemingly homogeneous CZTS thin film can actually have considerable structural and compositional variations at the microscale, and highlights the need for routine microscale characterization in this material system. PMID:27538122

  17. Fabrication of a Functionally Graded Copper-Zinc Sulfide Phosphor

    PubMed Central

    Park, Jehong; Park, Kwangwon; Kim, Jongsu; Jeong, Yongseok; Kawasaki, Akira; Kwon, Hansang

    2016-01-01

    Functionally graded materials (FGMs) are compositionally gradient materials. They can achieve the controlled distribution of the desired characteristics within the same bulk material. We describe a functionally graded (FG) metal-phosphor adapting the concept of the FGM; copper (Cu) is selected as a metal and Cu- and Cl-doped ZnS (ZnS:Cu,Cl) is selected as a phosphor and FG [Cu]-[ZnS:Cu,Cl] is fabricated by a very simple powder process. The FG [Cu]-[ZnS:Cu,Cl] reveals a dual-structured functional material composed of dense Cu and porous ZnS:Cu,Cl, which is completely combined through six graded mediating layers. The photoluminescence (PL) of FG [Cu]-[ZnS:Cu,Cl] is insensitive to temperature change. FG [Cu]-[ZnS:Cu,Cl] also exhibits diode characteristics and photo reactivity for 365 nm -UV light. Our FG metal-phosphor concept can pave the way to simplified manufacturing of low-cost and can be applied to various electronic devices. PMID:26972313

  18. Fabrication of a Functionally Graded Copper-Zinc Sulfide Phosphor.

    PubMed

    Park, Jehong; Park, Kwangwon; Kim, Jongsu; Jeong, Yongseok; Kawasaki, Akira; Kwon, Hansang

    2016-01-01

    Functionally graded materials (FGMs) are compositionally gradient materials. They can achieve the controlled distribution of the desired characteristics within the same bulk material. We describe a functionally graded (FG) metal-phosphor adapting the concept of the FGM; copper (Cu) is selected as a metal and Cu- and Cl-doped ZnS (ZnS:Cu,Cl) is selected as a phosphor and FG [Cu]-[ZnS:Cu,Cl] is fabricated by a very simple powder process. The FG [Cu]-[ZnS:Cu,Cl] reveals a dual-structured functional material composed of dense Cu and porous ZnS:Cu,Cl, which is completely combined through six graded mediating layers. The photoluminescence (PL) of FG [Cu]-[ZnS:Cu,Cl] is insensitive to temperature change. FG [Cu]-[ZnS:Cu,Cl] also exhibits diode characteristics and photo reactivity for 365 nm -UV light. Our FG metal-phosphor concept can pave the way to simplified manufacturing of low-cost and can be applied to various electronic devices. PMID:26972313

  19. Fabrication of a Functionally Graded Copper-Zinc Sulfide Phosphor

    NASA Astrophysics Data System (ADS)

    Park, Jehong; Park, Kwangwon; Kim, Jongsu; Jeong, Yongseok; Kawasaki, Akira; Kwon, Hansang

    2016-03-01

    Functionally graded materials (FGMs) are compositionally gradient materials. They can achieve the controlled distribution of the desired characteristics within the same bulk material. We describe a functionally graded (FG) metal-phosphor adapting the concept of the FGM; copper (Cu) is selected as a metal and Cu- and Cl-doped ZnS (ZnS:Cu,Cl) is selected as a phosphor and FG [Cu]-[ZnS:Cu,Cl] is fabricated by a very simple powder process. The FG [Cu]-[ZnS:Cu,Cl] reveals a dual-structured functional material composed of dense Cu and porous ZnS:Cu,Cl, which is completely combined through six graded mediating layers. The photoluminescence (PL) of FG [Cu]-[ZnS:Cu,Cl] is insensitive to temperature change. FG [Cu]-[ZnS:Cu,Cl] also exhibits diode characteristics and photo reactivity for 365 nm -UV light. Our FG metal-phosphor concept can pave the way to simplified manufacturing of low-cost and can be applied to various electronic devices.

  20. Microbial Ecology Assessment of Mixed Copper Oxide/Sulfide Dump Leach Operation

    SciTech Connect

    Bruhn, D F; Thompson, D N; Noah, K S

    1999-06-01

    Microbial consortia composed of complex mixtures of autotrophic and heterotrophic bacteria are responsible for the dissolution of metals from sulfide minerals. Thus, an efficient copper bioleaching operation depends on the microbial ecology of the system. A microbial ecology study of a mixed oxide/sulfide copper leaching operation was conducted using an "overlay" plating technique to differentiate and identify various bacterial consortium members of the genera Thiobacillus, Leptospirillum, Ferromicrobium, and Acidiphilium. Two temperatures (30C and 45C) were used to select for mesophilic and moderately thermophilic bacteria. Cell numbers varied from 0-106 cells/g dry ore, depending on the sample location and depth. After acid curing for oxide leaching, no viable bacteria were recovered, although inoculation of cells from raffinate re-established a microbial population after three months. Due to the low pH of the operation, very few non-iron-oxidizing acidophilic heterotrophs were recovered. Moderate thermophiles were isolated from the ore samples. Pregnant liquor solutions (PLS) and raffinate both contained a diversity of bacteria. In addition, an intermittently applied waste stream that contained high levels of arsenic and fluoride was tested for toxicity. Twenty vol% waste stream in PLS killed 100% of the cells in 48 hours, indicating substantial toxicity and/or growth inhibition. The data indicate that bacteria populations can recover after acid curing, and that application of the waste stream to the dump should be avoided. Monitoring the microbial ecology of the leaching operation provided significant information that improved copper recovery.

  1. Thin films of copper antimony sulfide: A photovoltaic absorber material

    SciTech Connect

    Ornelas-Acosta, R.E.; Shaji, S.; Avellaneda, D.; Castillo, G.A.; Das Roy, T.K.; Krishnan, B.

    2015-01-15

    Highlights: • CuSbS{sub 2} thin films were prepared by heating Sb{sub 2}S{sub 3}/Cu layers. • Analyzed the structure, composition, optical, and electrical properties. • PV structures: glass/SnO{sub 2}:F/n-CdS/p-CuSbS{sub 2}/C/Ag were formed at different conditions. • The PV parameters (J{sub sc}, V{sub oc}, and FF) were evaluated from the J–V characteristics. • J{sub sc}: 0.52–3.20 mA/cm{sup 2}, V{sub oc}:187–323 mV, FF: 0.27–0.48 were obtained. - Abstract: In this work, we report preparation and characterization of CuSbS{sub 2} thin films by heating glass/Sb{sub 2}S{sub 3}/Cu layers and their use as absorber material in photovoltaic structures: glass/SnO{sub 2}:F/n-CdS/p-CuSbS{sub 2}/C/Ag. The Sb{sub 2}S{sub 3} thin films of 600 nm were prepared by chemical bath deposition on which copper thin films of 50 nm were thermally evaporated, and the glass/Sb{sub 2}S{sub 3}/Cu multilayers were heated in vacuum at different temperatures. X-ray diffraction analysis showed the formation of orthorhombic CuSbS{sub 2} after heating the precursor layers. Studies on identification and chemical state of the elements were done using X-ray photoelectron spectroscopy. The optical band gap of the CuSbS{sub 2} thin films was 1.55 eV and the thin films were photoconductive. The photovoltaic parameters of the devices using CuSbS{sub 2} as absorber and CdS as window layer were evaluated from the J–V curves, yielding J{sub sc}, V{sub oc}, and FF values in the range of 0.52–3.20 mA/cm{sup 2}, 187–323 mV, and 0.27–0.48, respectively, under illumination of AM1.5 radiation.

  2. Development of copper sulfide/cadmium sulfide thin-film solar cells

    SciTech Connect

    Szedon, J. R.; Biter, W. J.; Dickey, H. C.

    1982-03-08

    The most important accomplishments during this period were to demonstrate and to elucidate further the complex effects that occur during the aging of Cu/sub 2/S/CdS thin-film solar cells in flowing wet oxygen. There are two distinct effects. At constant illumination, the short-circuit current of cells aged at room temperature consistently decreases with time. The second effect, related to diode opposing current, is more involved and may result from several competing mechanisms. Over the short term (approx. 4 to 5 hours), the magnitude of diode opposing current decreases. After approx. 20 hours of aging, opposing current generally returns to the level achieved after hydrogen annealing which immediately preceded the aging sequence. Optical measurements of the spectral transmission of the Cu/sub 2/S layers in a cell content have been made using a silicon detector epoxied to the back of a CdS cell after the copper foil substrate was removed. There is no significant change in Cu/sub 2/S transmission behavior for wavelengths ranging from 525 to 1000 nm during wet-oxygen aging for periods of 2 to 36 hours. This suggests that the decrease in J/sub SC/ at constant illumination, for the aging experiments in a flowing wet-oxygen ambient, arises because of changes in minority-carrier transport properties of the Cu/sub 2/S. Before developing a method for using an epoxied silicon detector to measure optical behavior of the Cu/sub 2/S layer, we explored the possibility of using a junction-containing wafer of silicon as a substrate for deposited CdS films. Some monolithic structures were successfully fabricated. Comparisons were made of CdS grain structure details in the junction detector area and in an adjacent metallized area.

  3. Development of copper sulfide/cadmium sulfide thin-film solar cells

    SciTech Connect

    Szedon, J.R.; Biter, W.J.; Abel, J.A.; Dickey, H.C.; Shirland, F.A.

    1981-02-27

    The purpose of this work has been to identify aspects of cell fabrication and treatment which are critical for achieving high efficiency Cu/sub 2/S/CdS solar cells. In approaching the problem several comparisons were made of the effects of specific steps in two methods of cell fabrication. These methods had previously given cells of about 6% and a maximum of 9% efficiency. Three areas requiring special attention and specific means to achieve acceptable results were identified. (1) The Cu/sub 2/S/CdS heterojunction area must be minimized. If single source evaporations of CdS are made on substrates whose temperatures (approx. 220/sup 0/C) are monitored and controlled using welded thermocouples, the CdS films will have adequately large grains (grain diameter greater than or equal to 2 ..mu..m) and will not develop significant etch pits during texturing in a mild etchant solution. (2) The termination of the wet barrier processing steps must be done carefully. An acceptable termination involves minimizing the amount of cuprous chloride retained on the cell surface during transfer to a rinsing stage while providing adequate exclusion of air from the space above the surface of the cuprous chloride solution. (3) Once formed, the Cu/sub 2/S layer should not be exposed to high temperatures (>100/sup 0/C) for long periods of time (> 5 min) if surface adsorbed moisture or oxygen are present. Heat treatments in ampoules under flowing hydrogen atmospheres should be preceded and followed by periods of at least 30 minutes at room temperature in the reducing ambient. If all these precautions are taken, wet chemical barrier processing of thermally evaporated CdS films on zinc-plated copper foil substrates yields cells of nearly 8% conversion efficiency without AR coating.

  4. Nontoxic and abundant copper zinc tin sulfide nanocrystals for potential high-temperature thermoelectric energy harvesting.

    PubMed

    Yang, Haoran; Jauregui, Luis A; Zhang, Genqiang; Chen, Yong P; Wu, Yue

    2012-02-01

    Improving energy/fuel efficiency by converting waste heat into electricity using thermoelectric materials is of great interest due to its simplicity and reliability. However, many thermoelectric materials are composed of either toxic or scarce elements. Here, we report the experimental realization of using nontoxic and abundant copper zinc tin sulfide (CZTS) nanocrystals for potential thermoelectric applications. The CZTS nanocrystals can be synthesized in large quantities from solution phase reaction and compressed into robust bulk pellets through spark plasma sintering and hot press while still maintaining nanoscale grain size inside. Electrical and thermal measurements have been performed from 300 to 700 K to understand the electron and phonon transports. Extra copper doping during the nanocrystal synthesis introduces a significant improvement in the performance. PMID:22214524

  5. Bioflotation of sulfide minerals with Acidithiobacillus ferrooxidans in relation to copper activation and surface oxidation.

    PubMed

    Pecina-Treviño, E T; Ramos-Escobedo, G T; Gallegos-Acevedo, P M; López-Saucedo, F J; Orrantia-Borunda, E

    2012-08-24

    Surface oxidation of sulfides and copper (Cu) activation are 2 of the main processes that determine the efficiency of flotation. The present study was developed with the intention to ascertain the role of the phenomena in the biomodification of sulfides by Acidithiobacillus ferrooxidans culture (cells and growth media) and their impact in bioflotation. Surface characteristics of chalcopyrite, sphalerite, and pyrrhotite, alone and in mixtures, after interaction with A. ferrooxidans were evaluated. Chalcopyrite floatability was increased substantially by biomodification, while bacteria depressed pyrrhotite floatability, favoring separation. The results showed that elemental sulfur concentration increased because of the oxidation generated by bacterial cells, the effect is intensified by the Fe(III) left in the culture and by galvanic contact. Acidithiobacillus ferrooxidans culture affects the Cu activation of sphalerite. The implications of elemental sulfur concentration and Cu activation of sphalerite are key factors that must be considered for the future development of sulfide bioflotation processes, since the depressive effect of cells could be counteracted by elemental sulfur generation. PMID:22920540

  6. Copper sulfides for rechargeable lithium batteries: Linking cycling stability to electrolyte composition

    NASA Astrophysics Data System (ADS)

    Jache, Birte; Mogwitz, Boris; Klein, Franziska; Adelhelm, Philipp

    2014-02-01

    Copper sulfides are attractive electrode materials as their reaction with lithium offers high capacity and energy density. However, the reversibility is poor and (nano)structuring is considered necessary to achieve moderate improvements. In contrast, we show in this study that the electrolyte is a major factor that governs the reversibility of the cell reaction. All our experiments were done with commercially available copper sulfides (CuS and Cu2S) without any special nanostructure. Different electrolyte compositions were tested among LiPF6 in EC/DMC and LiTFSI in DOL/DME. While rapid capacity fading is found in cells containing carbonate-based electrolytes, cells with ether-based electrolytes show a much better electrochemical performance. For a mixture of 1 M LiTFSI in DOL/DME, Cu2S can be cycled with capacities of around 200 mAh g-1 for more than 150 cycles with coulombic efficiencies >98.4%, for example. The improved stability in the ether-based electrolyte further allowed us to study how the discharge and charge voltage change during prolonged cycling. Our study underlines that improvements in the Li/CuS and Li/Cu2S system are still possible by very simple measures, but further studies on the complex Li-Cu-S phase behavior are necessary to understand the discharging and especially the charging mechanisms.

  7. Synthesis, Deposition, and Microstructure Development of Thin Films Formed by Sulfidation and Selenization of Copper Zinc Tin Sulfide Nanocrystals

    NASA Astrophysics Data System (ADS)

    Chernomordik, Boris David

    Significant reduction in greenhouse gas emission and pollution associated with the global power demand can be accomplished by supplying tens-of-terawatts of power with solar cell technologies. No one solar cell material currently on the market is poised to meet this challenge due to issues such as manufacturing cost, material shortage, or material toxicity. For this reason, there is increasing interest in efficient light-absorbing materials that are comprised of abundant and non-toxic elements for thin film solar cell. Among these materials are copper zinc tin sulfide (Cu2ZnSnS4, or CZTS), copper zinc tin selenide (Cu2ZnSnSe4, or CZTSe), and copper zinc tin sulfoselenide alloys [Cu2ZnSn(SxSe1-x )4, or CZTSSe]. Laboratory power conversion efficiencies of CZTSSe-based solar cells have risen to almost 13% in less than three decades of research. Meeting the terawatt challenge will also require low cost fabrication. CZTSSe thin films from annealed colloidal nanocrystal coatings is an example of solution-based methods that can reduce manufacturing costs through advantages such as high throughput, high material utilization, and low capital expenses. The film microstructure and grain size affects the solar cell performance. To realize low cost commercial production and high efficiencies of CZTSSe-based solar cells, it is necessary to understand the fundamental factors that affect crystal growth and microstructure evolution during CZTSSe annealing. Cu2ZnSnS4 (CZTS) nanocrystals were synthesized via thermolysis of single-source cation and sulfur precursors copper, zinc and tin diethyldithiocarbamates. The average nanocrystal size could be tuned between 2 nm and 40 nm, by varying the synthesis temperature between 150 °C and 340 °C. The synthesis is rapid and is completed in less than 10 minutes. Characterization by X-ray diffraction, Raman spectroscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy confirm that the nanocrystals are nominally

  8. Microbial Ecology Assessment of Mixed Copper Oxide/Sulfide Dump Leach Operation

    SciTech Connect

    Bruhn, Debby Fox; Thompson, David Neal; Noah, Karl Scott

    1999-06-01

    Microbial consortia composed of complex mixtures of autotrophic and heterotrophic bacteria are responsible for the dissolution of metals from sulfide minerals. Thus, an efficient copper bioleaching operation depends on the microbial ecology of the system. A microbial ecology study of a mixed oxide/sulfide copper leaching operation was conducted using an "overlay" plating technique to differentiate and identify various bacterial consortium members of the genera Thiobacillus, “Leptospirillum”, “Ferromicrobium”, and Acidiphilium. Two temperatures (30°C and 45°C) were used to select for mesophilic and moderately thermophilic bacteria. Cell numbers varied from 0-106 cells/g dry ore, depending on the sample location and depth. After acid curing for oxide leaching, no viable bacteria were recovered, although inoculation of cells from raffinate re-established a microbial population after three months. Due to low the pH of the operation, very few non-iron-oxidizing acidophilic heterotrophs were recovered. Moderate thermophiles were isolated from the ore samples. Pregnant liquor solutions (PLS) and raffinate both contained a diversity of bacteria. In addition, an intermittently applied waste stream that contained high levels of arsenic and fluoride was tested for toxicity. Twenty vol% waste stream in PLS killed 100% of the cells in 48 hours, indicating substantial toxicity and/or growth inhibition. The data indicate that bacteria populations can recover after acid curing, and that application of the waste stream to the dump should be avoided. Monitoring the microbial ecology of the leaching operation provided significant information that improved copper recovery.

  9. Hydrothermal processes in partially serpentinized peridotites from Costa Rica: evidence from native copper and complex sulfide assemblages

    NASA Astrophysics Data System (ADS)

    Schwarzenbach, Esther M.; Gazel, Esteban; Caddick, Mark J.

    2014-11-01

    Native metals and metal alloys are common in serpentinized ultramafic rocks, generally representing the redox and sulfur conditions during serpentinization. Variably serpentinized peridotites from the Santa Elena Ophiolite in Costa Rica contain an unusual assemblage of Cu-bearing sulfides and native copper. The opaque mineral assemblage consists of pentlandite, magnetite, awaruite, pyrrhotite, heazlewoodite, violarite, smythite and copper-bearing sulfides (Cu-pentlandite, sugakiite [Cu(Fe,Ni)8S8], samaniite [Cu2(Fe,Ni)7S8], chalcopyrite, chalcocite, bornite and cubanite), native copper and copper-iron-nickel alloys. Using detailed mineralogical examination, electron microprobe analyses, bulk rock major and trace element geochemistry, and thermodynamic calculations, we discuss two models to explain the formation of the Cu-bearing mineral assemblages: (1) they formed through desulfurization of primary sulfides due to highly reducing and sulfur-depleted conditions during serpentinization or (2) they formed through interaction with a Cu-bearing, higher temperature fluid (350-400 °C) postdating serpentinization, similar to processes in active high-temperature peridotite-hosted hydrothermal systems such as Rainbow and Logatchev. As mass balance calculations cannot entirely explain the extent of the native copper by desulfurization of primary sulfides, we propose that the native copper and Cu sulfides formed by local addition of a hydrothermal fluid that likely interacted with adjacent mafic sequences. We suggest that the peridotites today exposed on Santa Elena preserve the lower section of an ancient hydrothermal system, where conditions were highly reducing and water-rock ratios very low. Thus, the preserved mineral textures and assemblages give a unique insight into hydrothermal processes occurring at depth in peridotite-hosted hydrothermal systems.

  10. A mild and facile synthesis of aryl and alkenyl sulfides via copper-catalyzed deborylthiolation of organoborons with thiosulfonates.

    PubMed

    Yoshida, Suguru; Sugimura, Yasuyuki; Hazama, Yuki; Nishiyama, Yoshitake; Yano, Takahisa; Shimizu, Shigeomi; Hosoya, Takamitsu

    2015-12-01

    An efficient deborylthiolation of aryl- and alkenylborons with thiosulfonates has been achieved under mild conditions using a copper catalyst. All steps of the experimental process were free from unpleasant odors. The mild reaction conditions as well as ready availability of boron compounds and thiosulfonates enabled easy access to an array of sulfides, including those bearing sensitive functional groups. PMID:26447905

  11. Synthesis of unsymmetrical sulfides using ethyl potassium xanthogenate and recyclable copper catalyst under ligand-free conditions.

    PubMed

    Akkilagunta, Vijay Kumar; Kakulapati, Rama Rao

    2011-08-19

    The synthesis of unsymmetrical sulfides has been achieved in good to excellent yields with inexpensive ethyl potassium xanthogenate via cross-coupling reaction using recyclable CuO nanoparticles under ligand-free conditions.The copper oxide nanoparticles can be recovered and reused up to five cycles without loss of activity. PMID:21732640

  12. Synthesis, Deposition, and Microstructure Development of Thin Films Formed by Sulfidation and Selenization of Copper Zinc Tin Sulfide Nanocrystals

    NASA Astrophysics Data System (ADS)

    Chernomordik, Boris David

    Significant reduction in greenhouse gas emission and pollution associated with the global power demand can be accomplished by supplying tens-of-terawatts of power with solar cell technologies. No one solar cell material currently on the market is poised to meet this challenge due to issues such as manufacturing cost, material shortage, or material toxicity. For this reason, there is increasing interest in efficient light-absorbing materials that are comprised of abundant and non-toxic elements for thin film solar cell. Among these materials are copper zinc tin sulfide (Cu2ZnSnS4, or CZTS), copper zinc tin selenide (Cu2ZnSnSe4, or CZTSe), and copper zinc tin sulfoselenide alloys [Cu2ZnSn(SxSe1-x )4, or CZTSSe]. Laboratory power conversion efficiencies of CZTSSe-based solar cells have risen to almost 13% in less than three decades of research. Meeting the terawatt challenge will also require low cost fabrication. CZTSSe thin films from annealed colloidal nanocrystal coatings is an example of solution-based methods that can reduce manufacturing costs through advantages such as high throughput, high material utilization, and low capital expenses. The film microstructure and grain size affects the solar cell performance. To realize low cost commercial production and high efficiencies of CZTSSe-based solar cells, it is necessary to understand the fundamental factors that affect crystal growth and microstructure evolution during CZTSSe annealing. Cu2ZnSnS4 (CZTS) nanocrystals were synthesized via thermolysis of single-source cation and sulfur precursors copper, zinc and tin diethyldithiocarbamates. The average nanocrystal size could be tuned between 2 nm and 40 nm, by varying the synthesis temperature between 150 °C and 340 °C. The synthesis is rapid and is completed in less than 10 minutes. Characterization by X-ray diffraction, Raman spectroscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy confirm that the nanocrystals are nominally

  13. Water soluble sodium sulfate nanorods as a versatile template for the designing of copper sulfide nanotubes.

    PubMed

    Das, Gautam; Kakati, Nitul; Lee, Seok Hee; Karak, Niranjan; Yoon, Young Soo

    2014-06-01

    The present study reports the use of water soluble sodium sulfate (Na2SO4) nanorods as a versatile template for generation of tubular copper sulfide (CuS) nanostructures. The Na2SO4 nanorods were synthesized from ammonium sulfate (NH4)2SO4 and sodium hydroxide (NaOH), under refluxing condition. The shape and morphology control of the Na2SO4 nanorods were studied with respect to nature of surfactant used and reactant mole ratio. While, PVP mole ratio was important to obtain homogeneous nanorods. Uniform and stable nanotubes of CuS were than obtained by the dissolution of the nanorods in water. The use of simple chemicals for synthesis of such nanotube templates opens the prospect for wide scale downstream applications. PMID:24738412

  14. Optical and thermal response of single-walled carbon nanotube-copper sulfide nanoparticle hybrid nanomaterials.

    PubMed

    Tseng, Yi-Hsuan; He, Yuan; Lakshmanan, Santana; Yang, Chang; Chen, Wei; Que, Long

    2012-11-16

    This paper reports the optical and thermal response of a single-walled carbon nanotube-copper sulfide nanoparticle (SWNT-CuS NP) hybrid nanomaterial and its application as a thermoelectric generator. The hybrid nanomaterial was synthesized using oleylamine molecules as the linker molecules between SWNTs and CuS NPs. Measurements found that the hybrid nanomaterial has significantly increased light absorption (up to 80%) compared to the pure SWNT. Measurements also found that the hybrid nanomaterial thin-film devices exhibit a clear optical and thermal switching effect, which can be further enhanced up to 10 ×  by asymmetric illumination of light and thermal radiation on the thin-film devices instead of symmetric illumination. A simple prototype thermoelectric generator enabled by the hybrid nanomaterials is demonstrated, indicating a new route for achieving thermoelectricity. PMID:23089651

  15. Determination of (210)Po in drinking water and urine samples using copper sulfide microprecipitation.

    PubMed

    Guérin, Nicolas; Dai, Xiongxin

    2014-06-17

    Polonium-210 ((210)Po) can be rapidly determined in drinking water and urine samples by alpha spectrometry using copper sulfide (CuS) microprecipitation. For drinking water, Po in 10 mL samples was directly coprecipitated onto the filter for alpha counting without any purification. For urine, 10 mL of sample was heated, oxidized with KBrO3 for a short time (∼5 min), and subsequently centrifuged to remove the suspended organic matter. The CuS microprecipitation was then applied to the supernatant. Large batches of samples can be prepared using this technique with high recoveries (∼85%). The figures of merit of the methods were determined, and the developed methods fulfill the requirements for emergency and routine radioassays. The efficiency and reliability of the procedures were confirmed using spiked samples. PMID:24906041

  16. Synthesis of Copper-Antimony-Sulfide Nanocrystals for Solution-Processed Solar Cells.

    PubMed

    Suehiro, Satoshi; Horita, Keisuke; Yuasa, Masayoshi; Tanaka, Tooru; Fujita, Katsuhiko; Ishiwata, Yoichi; Shimanoe, Kengo; Kida, Tetsuya

    2015-08-17

    The p-type nanocrystals (NCs) of copper-based chalcogenides, such as CuInSe2 and Cu2ZnSnS4, have attracted increasing attention in photovoltaic applications due to their potential to produce cheap solution-processed solar cells. Herein, we report the synthesis of copper-antimony-sulfide (CAS) NCs with different crystal phases including CuSbS2, Cu3SbS4, and Cu12Sb4S13. In addition, their morphology, crystal phase, and optical properties were characterized using transmission electron microscopy, X-ray diffractometry, UV-vis-near-IR spectroscopy, and photoemission yield spectroscopy. The morphology, crystal phase, and electronic structure were significantly dependent on the chemical composition in the CAS system. Devices were fabricated using particulate films consisting of CAS NCs prepared by spin coating without a high-temperature treatment. The CAS NC-based devices exhibited a diode-like current-voltage characteristic when coupled with an n-type CdS layer. In particular, the CuSbS2 NC devices exhibited photovoltaic responses under simulated sunlight, demonstrating its applicability for use in solution-processed solar cells. PMID:26237216

  17. Nickel-cobalt-iron-copper sulfides and arsenides in solution-collapse breccia pipes, northwestern Arizona

    SciTech Connect

    Wenrich, K.J. ); Hlava, P.F. )

    1993-04-01

    An extensive suite of Ni-Co-Fe-Cu sulfides and arsenides lies within the matrix of solution-collapse breccias buried deep within the plateaus of the Grand Canyon region. Ceilings over large caverns in the Redwall collapsed, brecciating the overlying sandstone and forming cylindrical breccia pipes up to 300 ft in diameter that extend vertically as much as 3,000 ft. These highly permeable breccias served as a host for the precipitation of a suite of over 100 minerals, including uraninite, sphalerite, galena and various copper phases, in addition to the Ni-Co-bearing-phase discussed here. Intricately zoned crystals of small (<1 mm), euhedral Ni-Co-Fe-As-S minerals were the first to form during the second major episode of mineralization in these pipes. Several of these phases replace minerals, such as barite and anhydrite, from the first episode. Extensive microprobe work has been done on samples from two breccia pipe mines, the Hack 2 and Orphan, which are about 50 miles apart. Mineral compositions are similar except that no copper is found in the Ni-Co-Fe phases from the Hack 2 mine, while pyrites containing 1 wt % Cu are common from the Orphan, which was mined for copper. In some of these pyrites', Cu is dominant and the mineral is actually villamaninite. Pyrites from both mines characteristically contain 0.5 to 3 wt % As. Metal contents in zones pyrite-bravoite-vaesite (M[sub 1]S[sub 2]) crystals at the Hack 2 mine range from Fe[sub 1] to Fe[sub .12], Ni[sub 0] to Ni[sub .86], and Co[sub 0] to Co[sub .10]. The metal content for polydymite-siegenite-violarite averages about (Ni[sub 2.33]Co[sub .39]Fe[sub .23])(S[sub 3.9]As[sub .1]). Orphan mine pyrite-bravoite-vaesite-villamaninite ranges in composition from pure FeS[sub 2] to (Ni[sub .6]Fe[sub .21]Co[sub .17])S[sub 2], and (Cu[sub .46]Ni[sub .27]Fe[sub .21]Co[sub .13])S[sub 2]. Of all the sulfides or arsenides found in these breccia pipes, only nickeline consistently occurs as the pure end member.

  18. Structural, chemical and optical properties of the polyethylene-copper sulfide composite thin films synthesized using polythionic acid as sulfur source

    NASA Astrophysics Data System (ADS)

    Ancutiene, Ingrida; Navea, Juan G.; Baltrusaitis, Jonas

    2015-08-01

    Synthesis and properties of thin copper sulfide films deposited on polyethylene were explored for the development of low cost hybrid organic-inorganic photovoltaic materials. Polyethylene was used as a model organic host material for thin copper sulfide film formation. Adsorption-diffusion method was used which utilized consecutive exposure of polyethylene to polythionic acid followed by aqueous Cu(II/I) solution. Several crystalline copper sulfide phases were obtained in synthesized samples and elucidated using X-ray diffraction. Surface chemical composition determined using X-ray photoelectron spectroscopy showed the presence of copper sulfides in combination with copper hydroxide. Thickness of the composite material films ranged from several microns to ∼18 μm and depended on the Cu(II/I) exposure time. Bandgap of the materials obtained was measured and ranged from 1.88 to 1.17 eV. Importantly, heating these complex copper sulfide crystalline phase containing films at 100 °C in inert atmosphere invariably resulted in a single copper sulfide, anilite (Cu1.75S), phase. Anilite possesses a bandgap of 1.36 eV and has demonstrated excellent photovoltaic properties. Thus, the method described in this work can be used for a low cost large scale composite thin film photovoltaic material deposition based on anilite as photoactive material.

  19. Nanocrystalline copper sulfide of varying morphologies and stoichiometries in a low temperature solvothermal process using a new single-source molecular precursor

    NASA Astrophysics Data System (ADS)

    Bera, Pulakesh; Seok, Sang Il

    2012-08-01

    Surfactantless synthesis of copper sulfide nanoparticles (NPs) with varied morphologies such as hexagonal rods, rhombohedral, and spherical, has been carried out via low-temperature thermolysis of a new single-source precursor, [Cu(SMDTC)Cl2], (where SMDTC is S-methyl dithiocarbazate). The reaction parameters e.g., temperature and nature of solvent can be used to control the size and morphology of the nanoparticles. It is observed that the solvents played an important role to control the morphology and stoichiometry of copper sulfide. The anisotropic absorption by the chelating solvent (diamine or ethyleneglycol) at the different facets of the newborn microcrystals results the growth of one-dimensional (1D) copper sulfide NPs. The possible formation mechanism of copper sulfide NPs has also been discussed.

  20. Manganese (II) Chelate Functionalized Copper Sulfide Nanoparticles for Efficient Magnetic Resonance/Photoacoustic Dual-Modal Imaging Guided Photothermal Therapy

    PubMed Central

    Liu, Renfa; Jing, Lijia; Peng, Dong; Li, Yong; Tian, Jie; Dai, Zhifei

    2015-01-01

    The integration of diagnostic and therapeutic functionalities into one nanoplatform shows great promise in cancer therapy. In this research, manganese (II) chelate functionalized copper sulfide nanoparticles were successfully prepared using a facile hydrothermal method. The obtained ultrasmall nanoparticles exhibit excellent photothermal effect and photoaoustic activity. Besides, the high loading content of Mn(II) chelates makes the nanoparticles attractive T1 contrast agent in magnetic resonance imaging (MRI). In vivo photoacoustic imaging (PAI) results showed that the nanoparticles could be efficiently accumulated in tumor site in 24 h after systematic administration, which was further validated by MRI tests. The subsequent photothermal therapy of cancer in vivo was achieved without inducing any observed side effects. Therefore, the copper sulfide nanoparticles functionalized with Mn(II) chelate hold great promise as a theranostic nanomedicine for MR/PA dual-modal imaging guided photothermal therapy of cancer. PMID:26284144

  1. Using Plasmonic Copper Sulfide Nanocrystals as Smart Light-Driven Sterilants.

    PubMed

    Liu, Zhen; Liu, Xianjun; Du, Yingda; Ren, Jinsong; Qu, Xiaogang

    2015-10-27

    As an efficient route to control pet overpopulation and develop neutered experimental animals, male sterilization via surgical techniques, chemical injections, and antifertility vaccines has brought particular attention recently. However, these traditional ways usually induce long-term adverse reactions, immune suppression, and serious infection and pain. To overcome the above limitations, we developed a platform in the present study by using plasmonic copper sulfide nanocrystals (Cu2-xS NCs) as intelligent light-driven sterilants with ideal outcomes. Upon NIR laser irradiation, these well-prepared Cu2-xS NCs can possess NIR-induced hyperthermia and generate high levels of reactive oxygen species (ROS). Due to the cooperation of photothermal and photodynamic effects, these nanocrystals exhibited NIR-mediated toxicity toward Sertoli cells both in vitro and in vivo in a mild manner. We attribute the potential mechanism of cellular injury to the apoptosis-related death and denaturation of protein in the testicles. Furthermore, the possible metabolism route and long-term toxicity of these nanocrystals after testicular injection indicate their high biocompatibility. Taking together, our study on the NIR-induced toxicity of Cu2-xS NCs provides keen insights for the usage of plasmonic nanomaterials in biomedicine. PMID:26331394

  2. Bioleaching model of a copper-sulfide ore bed in heap and dump configurations

    NASA Astrophysics Data System (ADS)

    Casas, J. M.; Vargas, T.; Martinez, J.; Moreno, L.

    1998-08-01

    A two-dimensional (2-D) model for a heap or dump bioleaching of a copper ore containing mainly chalcocite and pyrite has been developed. The rate of the mineral sulfide dissolution was related to the rate of oxidation by bacteria attached onto the ore surface. The latter was calculated using the model of Michaelis-Menten, where both temperature and dissolved oxygen in the leach solution were taken into account by the kinetic equation. Oxygen transport through the ore bed was associated with natural air convection originating from the decrease in gas density inside the ore bed, which was attributable not only to heating, but also to humidification and decrease in the oxygen concentration. The model was used to estimate air-velocity fields and profiles of temperature and oxygen concentrations as well as mineral conversions during the bioleaching operation for ore beds with different pyrite contents, bacterial populations, widths, heights, and permeabilities. The model provides a useful tool for the design, improvement, and optimization of industrial operating conditions.

  3. Synthesis and Biomedical Applications of Copper Sulfide Nanoparticles: From Sensors to Theranostics

    PubMed Central

    Goel, Shreya; Chen, Feng; Cai, Weibo

    2013-01-01

    Copper sulfide (CuS) nanoparticles have attracted increasing attention from biomedical researchers across the globe, because of their intriguing properties which have been mainly explored for energy- and catalysis-related applications to date. This focused review article aims to summarize the recent progress made in the synthesis and biomedical applications of various CuS nanoparticles. After a brief introduction to CuS nanoparticles in the first section, we will provide a concise outline of the various synthetic routes to obtain different morphologies of CuS nanoparticles, which can influence their properties and potential applications. CuS nanoparticles have found broad applications in vitro, especially in the detection of biomolecules, chemicals, and pathogens which will be illustrated in detail. The in vivo uses of CuS nanoparticles have also been investigated in preclinical studies, including molecular imaging with various techniques, cancer therapy based on the photothermal properties of CuS, as well as drug delivery and theranostic applications. Research on CuS nanoparticles will continue to thrive over the next decade, and tremendous opportunities lie ahead for potential biomedical/clinical applications of CuS nanoparticles. PMID:24106015

  4. Seasonal distribution of organic matter and copper under stratified conditions in a karstic, marine, sulfide rich environment (Rogoznica Lake, Croatia)

    NASA Astrophysics Data System (ADS)

    Plavšić, Marta; Ciglenečki, Irena; Strmečki, Slađana; Bura-Nakić, Elvira

    2011-04-01

    Closed, isolated small systems, as the representatives of a "unique-environmental feature", are valuable natural laboratories for studying different biogeochemical processes. The saline Rogoznica Lake ("Dragon Eye"), situated on the Eastern Adriatic coast is such a system (10 276 m 2, 15 m deep) typical of many stratified, sulfide rich water bodies. The depth of mixolimnion changes seasonally and it is greatly influenced by meteorological conditions, i.e. temperature and rainfall. Vertical mixing usually occurs during winter when cold, oxygen-rich water from the surface sinks downwards. In 2009 we monitored seasonal distribution and variation of copper complexing capacity (L T), related apparent stability constants (K app), concentration of Cu 2+ ions, surfactant activity (SAS), dissolved organic carbon (DOC) and reduced sulfur species (RSS). Our results have shown that L T is increasing with depth up to 8 m depth, while the concentrations of copper ions decrease with the depth due to the higher amount of RSS species in deeper layers. The values of log K app are also decreasing with depth as a consequence of a competition of organic ligands and sulfide ions for binding Cu. Below 8 m depth the presence of high amounts of RSS (˜1 mM) influences the electrochemical measuring of copper ion and L T determination, contributing to the copper ion binding.

  5. Tin Ion Directed Morphology Evolution of Copper Sulfide Nanoparticles and Tuning of Their Plasmonic Properties via Phase Conversion.

    PubMed

    Chen, Lihui; Sakamoto, Masanori; Haruta, Mitsutaka; Nemoto, Takashi; Sato, Ryota; Kurata, Hiroki; Teranishi, Toshiharu

    2016-08-01

    Copper-deficient copper sulfide (Cu2-xS) nanoparticles (NPs) have been investigated as important hole-based plasmonic materials because of their size, morphology, and carrier density-dependent localized surface plasmon resonance (LSPR) properties. Morphology and carrier density are two important parameters to determine their LSPR properties. Here, we demonstrate that the foreign metal ion, Sn(4+), directs the growth of djurleite Cu31S16 from nanodisk to tetradecahedron along the [100] direction. To control the LSPR properties by tuning the carrier density, the djurleite Cu31S16 nanoparticles were pseudomorphically converted into more copper-deficient (higher carrier density) roxbyite Cu7S4 NPs by heat treatment in the presence of amine. The roxbyite Cu7S4 NPs exhibited a shorter and stronger LSPR peak while retaining the morphology of the djurleite Cu31S16 NPs. PMID:27398864

  6. Synthesis of Mesostructured Copper Sulfide by Cation Exchange and Liquid Crystal Templating

    SciTech Connect

    Lubeck, C R; Doyle, F M; Gash, A E; Satcher, J H; Han, T Y

    2005-08-01

    describe for the first time, the successful synthesis of highly ordered, mesostructured Cu{sub x}S, by combining the templating of the supramolecular assemblies of non-ionic amphiphilic polymer method with the cation exchange method to transform mesostructured cadmium sulfide (CdS) into mesostructured copper sulfides (CuS, Cu{sub 2}S).

  7. Reaction Mechanisms of Metals with Hydrogen Sulfide and Thiols in Model Wine. Part 1: Copper-Catalyzed Oxidation.

    PubMed

    Kreitman, Gal Y; Danilewicz, John C; Jeffery, David W; Elias, Ryan J

    2016-05-25

    Sulfidic off-odors as a result of hydrogen sulfide (H2S) and low-molecular-weight thiols are commonly encountered in wine production. These odors are usually removed by the process of Cu(II) fining, a process that remains poorly understood. The present study aims to elucidate the underlying mechanisms by which Cu(II) interacts with H2S and thiol compounds (RSH) under wine-like conditions. Copper complex formation was monitored along with H2S, thiol, oxygen, and acetaldehyde concentrations after the addition of Cu(II) (50 or 100 μM) to air-saturated model wine solutions containing H2S, cysteine, 6-sulfanylhexan-1-ol, or 3-sulfanylhexan-1-ol (300 μM each). The presence of H2S and thiols in excess to Cu(II) led to the rapid formation of ∼1.4:1 H2S/Cu and ∼2:1 thiol/Cu complexes, resulting in the oxidation of H2S and thiols and reduction of Cu(II) to Cu(I), which reacted with oxygen. H2S was observed to initially oxidize rather than form insoluble copper sulfide. The proposed reaction mechanisms provide insight into the extent to which H2S can be selectively removed in the presence of thiols in wine. PMID:27133282

  8. Formation of Hydrogen Sulfide in Wine: Interactions between Copper and Sulfur Dioxide.

    PubMed

    Bekker, Marlize Z; Smith, Mark E; Smith, Paul A; Wilkes, Eric N

    2016-01-01

    The combined synergistic effects of copper (Cu(2+)) and sulfur dioxide (SO₂) on the formation of hydrogen sulfide (H₂S) in Verdelho and Shiraz wine samples post-bottling was studied over a 12-month period. The combined treatment of Cu(2+) and SO₂ significantly increased H₂S formation in Verdelho wines samples that were not previously treated with either Cu(2+) or SO₂. The formation of H₂S produced through Cu(2+) mediated reactions was likely either: (a) directly through the interaction of SO₂ with either Cu(2+) or H₂S; or (b) indirectly through the interaction of SO₂ with other wine matrix compounds. To gain better understanding of the mechanisms responsible for the significant increases in H₂S concentration in the Verdelho samples, the interaction between Cu(2+) and SO₂ was studied in a model wine matrix with and without the presence of a representative thiol quenching compound (4-methylbenzoquinone, 4MBQ). In these model studies, the importance of naturally occurring wine compounds and wine additives, such as quinones, SO₂, and metal ions, in modulating the formation of H₂S post-bottling was demonstrated. When present in equimolar concentrations a 1:1 ratio of H₂S- and SO₂-catechol adducts were produced. At wine relevant concentrations, however, only SO₂-adducts were produced, reinforcing that the competition reactions of sulfur nucleophiles, such as H₂S and SO₂, with wine matrix compounds play a critical role in modulating final H₂S concentrations in wines. PMID:27626394

  9. Enhanced reactive adsorption of hydrogen sulfide on the composites of graphene/graphite oxide with copper (hydr)oxychlorides.

    PubMed

    Mabayoje, Oluwaniyi; Seredych, Mykola; Bandosz, Teresa J

    2012-06-27

    Composites of copper (hydr)oxychlorides with graphite oxide or graphene were synthesized and used as adsorbents of hydrogen sulfide at dynamic conditions at ambient temperatures. The materials were extensively characterized before and after adsorption in order to link their performance to the surface features. X-ray diffraction, FTIR, thermal analysis, TEM, SEM/EDX, and adsorption of nitrogen were used. It was found that the composite with graphene has the most favorable surface features enhancing reactive adsorption of hydrogen sulfide. The presence of moisture in the H2S stream has a positive effect on the removal process owing to the dissociation process. H2S is retained on the surface via a direct replacement of OH groups and via acid-base reactions with the copper (hydr)oxide. Highly dispersed reduced copper species on the surface of the composite with graphene enhance activation of oxygen and cause formation of sulfites and sulfates. Higher conductivity of the graphene phase than that of graphite oxide helps in electron transfer in redox reactions. PMID:22667349

  10. Growth evolution and phase transition from chalcocite to digenite in nanocrystalline copper sulfide: Morphological, optical and electrical properties

    PubMed Central

    Quintana-Ramirez, Priscilla Vasthi; Santos-Cruz, José; Vega-González, Marina; Martínez-Alvarez, Omar; Castaño-Meneses, Víctor Manuel; Acosta-Torres, Laura Susana; de la Fuente-Hernández, Javier

    2014-01-01

    Summary Copper sulfide is a promising p-type inorganic semiconductor for optoelectronic devices such as solar cells, due its small band gap energy and its electrical properties. In this work nanocrystalline copper sulfide (CuxS), with two stoichiometric ratios (x = 2, 1.8) was obtained by one-pot synthesis at 220, 230, 240 and 260 °C in an organic solvent and amorphous CuxS was obtained in aqueous solution. Nanoparticle-like nucleation centers are formed at lower temperatures (220 °C), mixtures of morphologies (nanorods, nanodisks and nanoprisms) are seen at 230 and 240 °C, in which the nanodisks are predominant, while big hexagonal/prismatic crystals are obtained at 260 °C according to TEM results. A mixture of chalcocite and digenite phases was found at 230 and 240 °C, while a clear transition to a pure digenite phase was seen at 260 °C. The evolution of morphology and transition of phases is consistent to the electrical, optical, and morphological properties of the copper sulfide. In fact, digenite Cu1.8S is less resistive (346 Ω/sq) and has a lower energy band gap (1.6 eV) than chalcocite Cu2S (5.72 × 105 Ω/sq, 1.87 eV). Low resistivity was also obtained in CuxS synthesized in aqueous solution, despite its amorphous structure. All CuxS products could be promising for optoelectronic applications. PMID:25247136

  11. Growth evolution and phase transition from chalcocite to digenite in nanocrystalline copper sulfide: Morphological, optical and electrical properties.

    PubMed

    Quintana-Ramirez, Priscilla Vasthi; Arenas-Arrocena, Ma Concepción; Santos-Cruz, José; Vega-González, Marina; Martínez-Alvarez, Omar; Castaño-Meneses, Víctor Manuel; Acosta-Torres, Laura Susana; de la Fuente-Hernández, Javier

    2014-01-01

    Copper sulfide is a promising p-type inorganic semiconductor for optoelectronic devices such as solar cells, due its small band gap energy and its electrical properties. In this work nanocrystalline copper sulfide (Cu x S), with two stoichiometric ratios (x = 2, 1.8) was obtained by one-pot synthesis at 220, 230, 240 and 260 °C in an organic solvent and amorphous Cu x S was obtained in aqueous solution. Nanoparticle-like nucleation centers are formed at lower temperatures (220 °C), mixtures of morphologies (nanorods, nanodisks and nanoprisms) are seen at 230 and 240 °C, in which the nanodisks are predominant, while big hexagonal/prismatic crystals are obtained at 260 °C according to TEM results. A mixture of chalcocite and digenite phases was found at 230 and 240 °C, while a clear transition to a pure digenite phase was seen at 260 °C. The evolution of morphology and transition of phases is consistent to the electrical, optical, and morphological properties of the copper sulfide. In fact, digenite Cu1.8S is less resistive (346 Ω/sq) and has a lower energy band gap (1.6 eV) than chalcocite Cu2S (5.72 × 10(5) Ω/sq, 1.87 eV). Low resistivity was also obtained in Cu x S synthesized in aqueous solution, despite its amorphous structure. All Cu x S products could be promising for optoelectronic applications. PMID:25247136

  12. Efficient Synthesis of Highly Luminescent Copper Indium Sulfide-Based Core/Shell Nanocrystals with Surprisingly Long-Lived Emission

    SciTech Connect

    Li, Liang; Pandey, Anshu; Werder, Donald J.; Khanal, Bishnu P.; Pietryga, Jeffrey M.; Klimov, Victor I.

    2011-02-09

    We report an efficient synthesis of copper indium sulfide nanocrystals with strong photoluminescence in the visible to near-infrared. This method can produce gram quantities of material with a chemical yield in excess of 90% with minimal solvent waste. The overgrowth of as-prepared nanocrystals with a few monolayers of CdS or ZnS increases the photoluminescence quantum efficiency to > 80%. On the basis of time-resolved spectroscopic studies of core/shell particles, we conclude that the emission is due to an optical transition that couples a quantized electron state to a localized hole state, which is most likely associated with an internal defect.

  13. Copper Sulfide Nanoparticles as a New Class of Photoacoustic Contrast Agent for Deep Tissue Imaging at 1064-nm

    PubMed Central

    Ku, Geng; Zhou, Min; Song, Shaoli; Huang, Qian; Hazle, John; Li, Chun

    2012-01-01

    Photoacoustic tomography (PAT) is an emerging molecular imaging modality. Here, we demonstrate use of semiconductor copper sulfide nanoparticles (CuS NP) for PAT with an Nd:YAG laser at a wavelength of 1064 nm. CuS NP allowed visualization of mouse brain after intracranial injection, rat lymph nodes 12 mm below the skin after interstitial injection, and CuS NP-containing agarose gel embedded in chicken breast muscle at the depth of ~ 5 cm. This imaging approach has great potential for molecular imaging of breast cancer. PMID:22812694

  14. Utilising copper screen-printed electrodes (CuSPE) for the electroanalytical sensing of sulfide.

    PubMed

    Thakur, Bhawana; Bernalte, Elena; Smith, Jamie P; Foster, Christopher W; Linton, Patricia E; Sawant, Shilpa N; Banks, Craig E

    2016-02-21

    A mediatorless sulfide electrochemical sensing platform utilising a novel nanocopper-oxide screen-printed electrodes (CuSPE) is reported for the first time. The state-of-the-art screen-printed electrochemical sensors demonstrate their capability to quantify sulfide within both the presence and absence of an array of interferents with good levels of sensitivity and repeatability. The direct sensing (using linear sweep voltammetry) of sulfide utilising the CuSPEs provides a mediatorless approach for the detection of sulfide, yielding useful analytical signatures that can be successfully quantified. The proposed novel protocol using the CuSPEs is successfully applied to the sensing of sulfide within drinking water exhibiting a high level of recovery. PMID:26815001

  15. Three approaches to economical photovoltaics: Conformal copper sulfide , organic luminescent films, and lead selenide nanocrystal superlattices

    NASA Astrophysics Data System (ADS)

    Carbone, Ian A.

    Three routes to more efficient photovoltaics using conformal Cu2S, organic luminescent films, and nanocrystalline PbSe films are outlined below. Properties of these materials are investigated experimentally and numerically in separate studies. In the first study, chemical vapor deposition (CVD) processes were used to fabricate Cu2S using hydrogen sulfide and the metal-organic precursor, KI5. The alternating exposure of mesoporous TiO2 and planar ZnO to the two precursors resulted in films that penetrated porous structures and deposited at a constant rate of 0.08nm/cycle over the temperature range 150C-400°C. Sheet resistance and optical absorption measurements suggest the presence of a metallic copper-poor phase of less than 100nm thick forming at the Cu2S/substrate boundary. In a separate study, organic films doped with luminescent dyes were placed above CdTe/CdS solar cells to convert high energy photons to lower energies, better matched to the CdTe/CdS quantum efficiency peak. Efficiency improvements of up to 8.5% were obtained after optimizing dye concentration, dye chemistry, and the host material. Long-term stability tests show that the organic films are stable for at least 5000 hours under 1 sun illumination provided that the dye is encapsulated in an oxygen and water free environment. Finally, a Monte Carlo model was developed to simulate electron and hole transport in nanocrystalline PbSe films. Transport is carried out as a series of thermally activated tunneling events between neighboring sites on a cubic lattice. Each site, representing an individual nanocrystal, is assigned a size-dependent electronic structure, and the effects of crystal size, charging, inter-crystal coupling, and energetic disorder on electron and hole mobilities/conductivities are investigated. Results of simulated field effect measurements confirm that electron mobilities and conductivities increase by an order of magnitude when the average nanocrystal diameter is increased in the

  16. Cadmium sulfide-copper sulfide heterojunction cell research. Quarterly progress report, December 1, 1979-February 29, 1980

    SciTech Connect

    1980-07-01

    Attempts have been continued to increase the short circuit current in cells of enhanced open circuit voltage. Both deposition of copper on the surface of the Cu/sub 2/S layer and hydrogen plasma treatments have been attempted. To date, no significant increase in ultimate current has been achieved. Various changes in cell production procedure have been made with significant improvements in reproducibility. Improvements in the structure of (CdZn)S layers and resulting cell properties have been achieved using modified substrates based on NiFe. Improvement have been made to the capacitance measuring systems with a consequent gain in resolution, accuracy and reproducibility. Structural studies of the electron beam deposited glass have revealed the presence of cracking and experiments have been carried out to determine the optimum deposition conditions for producing defect-free coatings.

  17. Weathering of sulfidic shale and copper mine waste: Secondary minerals and metal cycling in Great Smoky Mountains National Park, Tennessee, and North Carolina, USA

    USGS Publications Warehouse

    Hammarstrom, J.M.; Seal, R.R., II; Meier, A.L.; Jackson, J.C.

    2003-01-01

    Metal cycling via physical and chemical weathering of discrete sources (copper mines) and regional (non-point) sources (sulfide-rich shale) is evaluated by examining the mineralogy and chemistry of weathering products in Great Smoky Mountains National Park, Tennessee, and North Carolina, USA. The elements in copper mine waste, secondary minerals, stream sediments, and waters that are most likely to have negative impacts on aquatic ecosystems are aluminum, copper, zinc, and arsenic because these elements locally exceed toxicity guidelines for surface waters or for stream sediments. Acid-mine drainage has not developed in streams draining inactive copper mines. Acid-rock drainage and chemical weathering processes that accompany debris flows or human disturbances of sulfidic rocks are comparable to processes that develop acid-mine drainage elsewhere. Despite the high rainfall in the mountain range, sheltered areas and intermittent dry spells provide local venues for development of secondary weathering products that can impact aquatic ecosystems.

  18. Highly selective and sensitive colorimetric probe for hydrogen sulfide by a copper (II) complex of azo-dye based on chemosensing ensemble approach

    NASA Astrophysics Data System (ADS)

    Zhang, Dengqing; Jin, Wusong

    2012-05-01

    A copper (II) complex of azo-dye (Cu-1) has been synthesized by the reaction of 1-(2-pyridylazo)-2-naphthol (1) with copper (II) chloride. The complex Cu-1 is able to selectively sense hydrogen sulfide over other anions followed by the release of compound 1 to give a remarkable change of UV-vis absorption at neutral pH in aqueous solution.

  19. Copper sulfide nanoparticle-decorated graphene as a catalytic amplification platform for electrochemical detection of alkaline phosphatase activity.

    PubMed

    Peng, Juan; Han, Xiao-Xia; Zhang, Qing-Chun; Yao, Hui-Qin; Gao, Zuo-Ning

    2015-06-01

    Copper sulfide nanoparticle-decorated graphene sheet (CuS/GR) was successfully synthesized and used as a signal amplification platform for electrochemical detection of alkaline phosphatase activity. First, CuS/GR was prepared through a microwave-assisted hydrothermal approach. The CuS/GR nanocomposites exhibited excellent electrocatalytic activity toward the oxidation of ALP hydrolyzed products such as 1-naphthol, which produced a current response. Thus, a catalytic amplification platform based on CuS/GR nanocomposite for electrochemical detection of ALP activity was designed using 1-naphthyl phosphate as a model substrate. The current response increased linearly with ALP concentration from 0.1 to 100 U L(-1) with a detection limit of 0.02 U L(-1). The assay was applied to estimate ALP activity in human serum samples with satisfactory results. This strategy may find widespread and promising applications in other sensing systems that involves ALP. PMID:26002329

  20. Size Dependence of a Temperature-Induced Solid-Solid Phase Transition in Copper(I) Sulfide

    SciTech Connect

    Rivest, Jessy B; Fong, Lam-Kiu; Jain, Prashant K; Toney, Michael F; Alivisatos, A Paul

    2011-07-24

    Determination of the phase diagrams for the nanocrystalline forms of materials is crucial for our understanding of nanostructures and the design of functional materials using nanoscale building blocks. The ability to study such transformations in nanomaterials with controlled shape offers further insight into transition mechanisms and the influence of particular facets. Here we present an investigation of the size-dependent, temperature-induced solid-solid phase transition in copper sulfide nanorods from low- to high-chalcocite. We find the transition temperature to be substantially reduced, with the high chalcocite phase appearing in the smallest nanocrystals at temperatures so low that they are typical of photovoltaic operation. Size dependence in phase trans- formations suggests the possibility of accessing morphologies that are not found in bulk solids at ambient conditions. These other- wise-inaccessible crystal phases could enable higher-performing materials in a range of applications, including sensing, switching, lighting, and photovoltaics.

  1. Highly sensitive photodetectors based on hybrid 2D-0D SnS2-copper indium sulfide quantum dots

    NASA Astrophysics Data System (ADS)

    Huang, Yun; Zhan, Xueying; Xu, Kai; Yin, Lei; Cheng, Zhongzhou; Jiang, Chao; Wang, Zhenxing; He, Jun

    2016-01-01

    Both high speed and efficiency of photoelectric conversion are essential for photodetectors. As an emerging layered metal dichalcogenide (LMD), tin disulfide owns intrinsic faster photodetection ability than most other LMDs but poor light absorption and low photoelectric conversion efficiency. We develop an efficient method to enhance its performance by constructing a SnS2-copper indium sulfide hybrid structure. As a result, the responsivity reaches 630 A/W, six times stronger than pristine SnS2 and much higher than most other LMDs photodetectors. Additionally, the photocurrents are enhanced by more than 1 order of magnitude. Our work may open up a pathway to improve the performance of photodetectors based on LMDs.

  2. Nanoparticles of zinc sulfide doped with manganese, nickel and copper as nanophotocatalyst in the degradation of organic dyes.

    PubMed

    Pouretedal, Hamid Reza; Norozi, Abbas; Keshavarz, Mohammad Hossein; Semnani, Abolfazl

    2009-03-15

    Nanoparticles of zinc sulfide as undoped and doped with manganese, nickel and copper were used as photocatalyst in the photodegradation of methylene blue and safranin as color pollutants. Photoreactivity of doped zinc sulfide was varied with dopant, mole fraction of dopant to zinc ion, pH of solution, dosage of photocatalyst and concentration of dye. The characterization of nanoparticles was studied using X-ray powder diffraction (XRD) patterns and UV-vis spectra. The maximum degradation efficiency was obtained in the presence of Zn(0.98)Mn(0.02)S, Zn(0.94)Ni(0.06)S and Zn(0.90)Cu(0.10)S as nanophotocatalyst. The effect of dosage of photocatalyst was studied in the range of 20-250 mg/L. It was seen that 150.0 mg/L of photocatacyst is an optimum value for the dosage of photocatalyst. The most degradation efficiency was obtained in alkaline pH of 11.0 with study of photodegradation in pH amplitude of 2-12. The degradation efficiency was decreased in dye concentrations above of 5.0 mg/L for methylene blue and safranin dyes. In the best conditions, the degradation efficiency was obtained 87.3-95.6 and 85.4-93.2 for methylene blue and safranin, respectively. PMID:18603365

  3. A green synthesis route for the phase and size tunability of copper antimony sulfide nanocrystals with high yield.

    PubMed

    Chen, Keqiang; Zhou, Jing; Chen, Wen; Chen, Qiao; Zhou, Peng; Liu, Yueli

    2016-03-01

    Until now, it is a great challenge for the controllable synthesis of copper antimony sulfide (CAS) nanocrystals (NCs), as the reactivity of precursors is quite difficult to be controlled during the synthesis process. In the present work, a novel solution-based method is proposed to synthesize CAS NCs by choosing N,N'-diphenylthiourea as the sulfide precursor, which is favorable for balancing the relative reactivity of Cu and Sb ions. It is found that three phases (CuSbS2, Cu12Sb4S13 and Cu3SbS4) of CAS NCs with size tunability were successfully synthesized for the first time. To the best of our knowledge, the lowest reaction temperature of 110 °C and the highest yield over 90% for CAS NCs were also achieved for the first time, which may be considered to be a green synthesis route compared with other conventional methods. Optical properties indicate that the as-prepared CAS NCs have strong optical absorption in the visible light region of the solar spectrum, and we also observed the band gap tunability of CuSbS2 and Cu3SbS4 materials for the first time. PMID:26875832

  4. The Copper Sulfide Coating on Polyacrylonitrile with Chelating Agents by an Electroless Deposition Method and its EMI Shielding Effectiveness

    SciTech Connect

    Roan, M.-L.; Chen, Y.-H.; Huang, C.-Y.

    2008-08-28

    In this study, a variety of concentrations of chelating agents were added to obtain the anchoring effect and chelating effect in the electroless plating bath. The mechanism of the Cu{sub x(x=1,2)}S growth and the electromagnetic interference shielding effectiveness (EMI SE) of the composite were studied. It was found that the vinyl acetate residued in PAN substrate would be purged due to the swelling effect by chelating agents solution. And then, the anchoring effect occurred due to the hydrogen bonding between the pits of PAN substrate and the chelating agent. Consequently, the copper sulfide layer deposited by the electroless plating reaction with EDTA and TEA. The swelling degree (S{sub d}) was proposed and evaluated from the FT-IR spectra. The relationship between swelling degree of the PAN films and EDTA (C) is expressed as: S{sub d} = 0.13+0.90xe and (-15.15C). And TEA series is expressed as: S{sub d} = 0.07+1.00xe and (-15.15C). On the other hand, the FESEM micrograph showed that the average thickness of copper sulfide increased from 76 nm to 383 nm when the concentration of EDTA increased from 0.00M to 0.20M. Consequently, the EMI SE of the composites increased from 10{approx}12 dB to 25{approx}27 dB. The GIA-XRD analyze indicated that the deposited layer consisted of CuS and Cu{sub 2}S.

  5. The Effect of Desulfovibrio sp. Biofilms on Corrosion Behavior of Copper in Sulfide-Containing Solutions

    NASA Astrophysics Data System (ADS)

    Güngör, Nihal Doğruöz; Çotuk, Ayşın; Dışpınar, Derya

    2015-03-01

    This study aims to detect the effect of Desulfovibrio sp. on copper in terms of biofilm formation and corrosion in 722 h. In that way, appropriate strategies to inhibit microbiological corrosion in copper systems with Desulfovibrio sp. can be evaluated. For this purpose, experiments were performed in 1 L glass model system containing 28 copper coupons and pure culture of the sulfate-reducing bacteria (SRB) strain Desulfovibrio sp. in Postgate's medium C. Also, a control system with copper coupons but without Desulfovibrio sp. containing sterile Postgate's medium was studied concurrently with the test system. The test coupons were collected from systems at certain time intervals, namely 24, 168, 360, and 720 h. The samples were then subjected to several characterization analyses such as measurement of Desulfovibrio sp. numbers, corrosion resistance, EPS extraction, carbohydrate analysis, SEM, and EDS. During the experiments, the maximum Desulfovibrio sp. count in biofilm samples was found at 360 h. Carbohydrate and copper concentrations in biofilm were increased over time. EDS analysis revealed Cu, S, C, O, and Cl peaks on the surface of the samples. For the control coupons, only Cu peaks were observed. The results obtained from this study showed that copper was corroded by Desulfovibrio sp. in the model system under laboratory conditions.

  6. Synthesis And Characterization of Copper Zinc Tin Sulfide Nanoparticles And Thin Films

    NASA Astrophysics Data System (ADS)

    Khare, Ankur

    Copper zinc tin sulfide (Cu2ZnSnS4, or CZTS) is emerging as an alternative material to the present thin film solar cell technologies such as Cu(In,Ga)Se2 and CdTe. All the elements in CZTS are abundant, environmentally benign, and inexpensive. In addition, CZTS has a band gap of ˜1.5 eV, the ideal value for converting the maximum amount of energy from the solar spectrum into electricity. CZTS has a high absorption coefficient (>104 cm-1 in the visible region of the electromagnetic spectrum) and only a few micron thick layer of CZTS can absorb all the photons with energies above its band gap. CZT(S,Se) solar cells have already reached power conversion efficiencies >10%. One of the ways to improve upon the CZTS power conversion efficiency is by using CZTS quantum dots as the photoactive material, which can potentially achieve efficiencies greater than the present thin film technologies at a fraction of the cost. However, two requirements for quantum-dot solar cells have yet to be demonstrated. First, no report has shown quantum confinement in CZTS nanocrystals. Second, the syntheses to date have not provided a range of nanocrystal sizes, which is necessary not only for fundamental studies but also for multijunction photovoltaic architectures. We resolved these two issues by demonstrating a simple synthesis of CZTS, Cu2SnS3, and alloyed (Cu2SnS3) x(ZnS)y nanocrystals with diameters ranging from 2 to 7 nm from diethyldithiocarbamate complexes. As-synthesized nanocrystals were characterized using high resolution transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and energy dispersive spectroscopy to confirm their phase purity. Nanocrystals of diameter less than 5 nm were found to exhibit a shift in their optical absorption spectra towards higher energy consistent with quantum confinement and previous theoretical predictions. Thin films from CZTS nanocrystals deposited on Mo-coated quartz substrates using drop casting were found to be continuous

  7. Formation and characterization of conductive thin layers of copper sulfide (Cu xS) on the surface of polyethylene and polyamide by the use of higher polythionic acids

    NASA Astrophysics Data System (ADS)

    Ancutiene, Ingrida; Janickis, Vitalijus; Ivanauskas, Remigijus

    2006-04-01

    Layers of copper sulfide of varying composition and properties are formed on the surface of polyethylene and polyamide by a sorption-diffusion method using solutions of higher polythionic acids, H 2S nO 6. The concentration of sulfur adsorbed-diffused into PE and PA depends on the degree of the acid sulfurity, n, the temperature of the solution and the period of the polymer treatment. The amount of copper in a sulfide (Cu xS) layer formed after the sulfured polymer treatment with a solution of Cu(I-II) salt is strongly dependent on the concentration of sulfur in the PE and PA. By the chemical analysis of the obtained sulfide layers was determined that a value of x in the Cu xS layers varies in the interval 1 < x < 2. The microscopic investigation of transverse sections of PE and PA samples with copper sulfide layers showed that the major part of copper sulfide is in the surface matrix of the polymer. X-ray diffraction studies of the Cu xS layers obtained seven phases: with x = 2 (chalcocite), 1.9375 (djurleite), 1.8 (digenite), 1.75 (anilite), 1.12 (yarrowite), 1.06 (talnakhite) and 1 (covellite). The measurements of the electrical conductance of Cu xS layers (0.1-4 S cm -2) showed that its value greatly depends on the conditions of PE and PA interaction with H 2S nO 6 and of further interaction with Cu(I-II) salt solution, on the chemical and phase composition of the layer.

  8. Optical and electrical stability of viral-templated copper sulfide (Cu{sub 1.8}S) films

    SciTech Connect

    Shahriar Zaman, Mohammed; Bernard Grajeda, Gabriel; Haberer, Elaine D.

    2014-04-14

    The optical and electrical stabilities of viral-templated non-stoichiometric copper sulfide, digenite (Cu{sub 1.8}S) films were investigated. The films were composed of large agglomerates of randomly aligned Cu{sub 1.8}S-coated M13 filamentous phage. Free carrier optical absorption associated with localized surface plasmon resonance (LSPR) was observed in the near infrared spectral region, and the films were electrically active, displaying a linear current-voltage relationship. Under ambient conditions, the magnitude of the LSPR absorption increased, following a power law relationship with time, and the electrical resistance of viral-templated films decreased significantly. In contrast, the resistance of films stored under low oxygen, low humidity conditions experienced a smaller reduction in electrical resistance. Changes in optical and electrical film properties under ambient conditions were associated with an increase in free carrier concentration within the copper chalcogenide material due to oxygen exposure. X-ray photoelectron spectroscopy was used to relate this increase in free carrier concentration to compositional changes on the viral-templated material surface.

  9. Copper sulfide nanoparticles with phospholipid-PEG coating for in vivo near-infrared photothermal cancer therapy.

    PubMed

    Huang, Yizhuan; Lai, Yulian; Shi, Saige; Hao, Shufang; Wei, Jingping; Chen, Xiaolan

    2015-02-01

    In this work, small sizes of hydrophobic copper sulfide nanoparticles (CuS NPs, ∼3.8 nm in diameter) have been successfully prepared from the reaction of copper chloride with sodium diethyldithiocarbamate (SDEDTC) inside a heated oleylamine solution. These CuS NPs displayed strong absorption in the 700-1100 nm near-infrared (NIR) region. By coating CuS NPs with DSPE-PEG2000 on the surface, the as-synthesized CuS@DSPE-PEG NPs exhibited good water solubility, significant stability and biocompatibility, as well as excellent photothermal conversion effects upon exposure to an 808 nm laser. After intravenous administration to mice, the CuS@DSPE-PEG NPs were found to passively target to the tumor site, and tumor tissues could be ablated efficiency under laser irradiation. In addition, CuS@DSPE-PEG NPs do not show significant toxicity by histological and blood chemistry analysis, and can be effectively excreted via metabolism. Our results indicated that CuS@DSPE-PEG NPs can act as an ideal photothermal agent for cancer photothermal therapy. PMID:25425287

  10. An efficient and transparent copper sulfide nanosheet film counter electrode for bifacial quantum dot-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Ke, Weijun; Fang, Guojia; Lei, Hongwei; Qin, Pingli; Tao, Hong; Zeng, Wei; Wang, Jing; Zhao, Xingzhong

    2014-02-01

    Copper sulfide (CuS) with nanosheet structure has been synthesized at a low temperature in situ on copper (Cu) film coated fluorine-doped tin oxide glass and bifacial quantum dot-sensitized solar cells (QDSSCs) were herein developed by using these CuS as counter electrodes (CEs). CuS is an environmental compatible and low toxic material. The obtained two-dimensional CuS nanosheet film presents high carrier mobility and exhibits highly catalytic performance for the polysulfide-based electrolyte. The QDSSC based on a CuS CE presents a power conversion efficiency (PCE) of 3.65% by optimizing the thickness of the Cu film under front illumination. The QDSSC based on a CuS CE prepared with a 200 nm thick Cu film shows a very close PCE under front and rear illuminations in which the values are as high as 2.70% and 2.40%, respectively. All the PCEs of the CuS CEs are much higher than that of the Pt CE (1.34%).

  11. Lead isotope compositions of Late Cretaceous and early Tertiary igneous rocks and sulfide minerals in Arizona: Implications for the sources of plutons and metals in porphyry copper deposits

    USGS Publications Warehouse

    Bouse, R.M.; Ruiz, J.; Titley, S.R.; Tosdal, R.M.; Wooden, J.L.

    1999-01-01

    Porphyry copper deposits in Arizona are genetically associated with Late Cretaceous and early Tertiary igneous complexes that consist of older intermediate volcanic rocks and younger intermediate to felsic intrusions. The igneous complexes and their associated porphyry copper deposits were emplaced into an Early Proterozoic basement characterized by different rocks, geologic histories, and isotopic compositions. Lead isotope compositions of the Proterozoic basement rocks define, from northwest to southeast, the Mojave, central Arizona, and southeastern Arizona provinces. Porphyry copper deposits are present in each Pb isotope province. Lead isotope compositions of Late Cretaceous and early Tertiary plutons, together with those of sulfide minerals in porphyry copper deposits and of Proterozoic country rocks, place important constraints on genesis of the magmatic suites and the porphyry copper deposits themselves. The range of age-corrected Pb isotope compositions of plutons in 12 Late Cretaceous and early Tertiary igneous complexes is 206Pb/204Pb = 17.34 to 22.66, 207Pb/204Pb = 15.43 to 15.96, and 208Pb/204Pb = 37.19 to 40.33. These Pb isotope compositions and calculated model Th/U are similar to those of the Proterozoic rocks in which the plutons were emplaced, thereby indicating that Pb in the younger rocks and ore deposits was inherited from the basement rocks and their sources. No Pb isotope differences distinguish Late Cretaceous and early Tertiary igneous complexes that contain large economic porphyry copper deposits from less rich or smaller deposits that have not been considered economic for mining. Lead isotope compositions of Late Cretaceous and early Tertiary plutons and sulfide minerals from 30 metallic mineral districts, furthermore, require that the southeastern Arizona Pb province be divided into two subprovinces. The northern subprovince has generally lower 206Pb/204Pb and higher model Th/U, and the southern subprovince has higher 206Pb/204Pb and

  12. In situ solvothermal growth of metal-organic framework-5 supported on porous copper foam for noninvasive sampling of plant volatile sulfides.

    PubMed

    Hu, Yuling; Lian, Haixian; Zhou, Langjun; Li, Gongke

    2015-01-01

    The present study reported on an in situ solvothermal growth method for immobilization of metal-organic framework MOF-5 on porous copper foam support for enrichment of plant volatile sulfides. The porous copper support impregnated with mother liquor of MOF-5 anchors the nucleation and growth of MOF crystallites at its surface, and its architecture of the three-dimensional channel enables accommodation of the MOF-5 crystallite seed. A continuous and well-intergrown MOF-5 layer, evidenced from scanning electron microscope imaging and X-ray diffraction, was successfully immobilized on the porous metal bar with good adhesion and high stability. Results show that the resultant MOF-5 coating was thermally stable up to 420 °C and robust enough for replicate extraction for at least 200 times. The MOF-5 bar was then applied to the headspace sorptive extraction of the volatile organic sulfur compounds in Chinese chive and garlic sprout in combination with thermal desorption-gas chromatography/mass spectrometry. It showed high extraction sensitivity and good selectivity to these plant volatile sulfides owing to the extraordinary porosity of the metal-organic framework as well as the interaction between the S-donor sites and the surface cations at the crystal edges. Several primary sulfur volatiles containing allyl methyl sulfide, dimethyl disulfide, diallyl sulfide, methyl allyl disulfide, and diallyl disulfide were quantified. Their limits of detection were found to be in the range of 0.2-1.7 μg/L. The organic sulfides were detected in the range of 6.0-23.8 μg/g with recoveries of 76.6-100.2% in Chinese chive and 11.4-54.6 μg/g with recoveries of 77.1-99.8% in garlic sprout. The results indicate the immobilization of MOF-5 on copper foam provides an efficient enrichment formats for noninvasive sampling of plant volatiles. PMID:25435245

  13. Study of copper sulfide counter electrode on the performances of CdS/CdSe/ZnS-sensitized hierarchical TiO2 spheres quantum dots solar cells

    NASA Astrophysics Data System (ADS)

    Buatong, Nattha; Tang, I.-Ming; Pon-On, Weeraphat

    2015-07-01

    The effects of using copper sulfide (CuS) counter electrodes on the performances of solar cells made with CdS/CdSe/ZnS quantum dots co-sensitized onto hierarchical TiO2 spheres (HTS) used as photoelectrode is reported. The HTS in the QDSSCs is composed of an assembly of numerous TiO2 spheres made by the solvolthermal method. The photoelectrical performance of HTS/CdS/CdSe/ZnS coupled to CuS counter electrode was compared to those coupled to Pt CE. The HTS/CdS/CdSe/ZnS coupled to the CuS CE showed the highest power conversion efficiency η (of 1.310 %.) which is significantly higher than those using a standard Pt CE (η = 0.374%) (3.50 fold). This higher efficiency is the results of the higher electrocatalytic activities when the copper sulfide CEs is used.

  14. Iron sulfide attenuates the methanogenic toxicity of elemental copper and zinc oxide nanoparticles and their soluble metal ion analogs.

    PubMed

    Gonzalez-Estrella, Jorge; Gallagher, Sara; Sierra-Alvarez, Reyes; Field, Jim A

    2016-04-01

    Elemental copper (Cu(0)) and zinc oxide (ZnO) nanoparticle (NP) toxicity to methanogens has been attributed to the release of soluble metal ions. Iron sulfide (FeS) partially controls the soluble concentration of heavy metals and their toxicity in aquatic environments. Heavy metals displace the Fe from FeS forming poorly soluble metal sulfides in the FeS matrix. Therefore, FeS may be expected to attenuate the NP toxicity. This work assessed FeS as an attenuator of the methanogenic toxicity of Cu(0) and ZnO NPs and their soluble salt analogs. The toxicity attenuation capacity of fine (25-75μm) and coarse (500 to 1200μm) preparations of FeS (FeS-f and FeS-c respectively) was tested in the presence of highly inhibitory concentrations of CuCl2, ZnCl2 Cu(0) and ZnO NPs. FeS-f attenuated methanogenic toxicity better than FeS-c. The results revealed that 2.5× less FeS-f than FeS-c was required to recover the methanogenic activity to 50% (activity normalized to uninhibited controls). The results also indicated that a molar FeS-f/Cu(0) NP, FeS-f/ZnO NP, FeS-f/ZnCl2, and FeS-f/CuCl2 ratio of 2.14, 2.14, 4.28, and 8.56 respectively, was necessary to recover the methanogenic activity to >75%. Displacement experiments demonstrated that CuCl2 and ZnCl2 partially displaced Fe from FeS. As a whole, the results indicate that not all the sulfide in FeS was readily available to react with the soluble Cu and Zn ions which may explain the need for a large stoichiometric excess of FeS to highly attenuate Cu and Zn toxicity. Overall, this study provides evidence that FeS attenuates the toxicity caused by Cu(0) and ZnO NPs and their soluble ion analogs to methanogens. PMID:26803736

  15. Magmatic sulfide-rich nickel-copper deposits related to picrite and (or) tholeiitic basalt dike-sill complexes-A preliminary deposit model

    USGS Publications Warehouse

    Schulz, Klaus J.; Chandler, Val W.; Nicholson, Suzanne W.; Piatak, Nadine M.; Seal, Robert R., II; Woodruff, Laurel G.; Zientek, Michael L.

    2010-01-01

    Magmatic sulfide deposits containing nickel (Ni) and copper (Cu), with or without (?) platinum-group elements (PGEs), account for approximately 60 percent of the world's Ni production and are active exploration targets in the United States and elsewhere. On the basis of their principal metal production, magmatic sulfide deposits in mafic rocks can be divided into two major types: those that are sulfide-rich, typically with 10 to 90 percent sulfide minerals, and have economic value primarily because of their Ni and Cu contents; and those that are sulfide-poor, typically with 0.5 to 5 percent sulfide minerals, and are exploited principally for PGE. Because the purpose of this deposit model is to facilitate the assessment for undiscovered, potentially economic magmatic Ni-Cu?PGE sulfide deposits in the United States, it addresses only those deposits of economic significance that are likely to occur in the United States on the basis of known geology. Thus, this model focuses on deposits hosted by small- to medium-sized mafic and (or) ultramafic dikes and sills that are related to picrite and tholeiitic basalt magmatic systems generally emplaced in continental settings as a component of large igneous provinces (LIPs). World-class examples (those containing greater than 1 million tons Ni) of this deposit type include deposits at Noril'sk-Talnakh (Russia), Jinchuan (China), Pechenga (Russia), Voisey's Bay (Canada), and Kabanga (Tanzania). In the United States, this deposit type is represented by the Eagle deposit in northern Michigan, currently under development by Kennecott Minerals.

  16. Size-tunable copper nanocluster aggregates and their application in hydrogen sulfide sensing on paper-based devices

    PubMed Central

    Chen, Po-Cheng; Li, Yu-Chi; Ma, Jia-Yin; Huang, Jia-Yu; Chen, Chien-Fu; Chang, Huan-Tsung

    2016-01-01

    Polystyrene sulfonate (PSS), a strong polyelectrolyte, was used to prepare red photoluminescent PSS-penicillamine (PA) copper (Cu) nanoclusters (NC) aggregates, which displayed high selectivity and sensitivity to the detection of hydrogen sulfide (H2S). The size of the PSS-PA-Cu NC aggregates could be readily controlled from 5.5 μm to 173 nm using different concentrations of PSS, which enabled better dispersity and higher sensitivity towards H2S. PSS-PA-Cu NC aggregates provided rapid H2S detection by using the strong Cu-S interaction to quench NC photoluminescence as a sensing mechanism. As a result, a detection limit of 650 nM, which is lower than the maximum level permitted in drinking water by the World Health Organization, was achieved for the analysis of H2S in spring-water samples. Moreover, highly dispersed PSS-PA-Cu NC aggregates could be incorporated into a plate-format paper-based analytical device which enables ultra-low sample volumes (5 μL) and feature shorter analysis times (30 min) compared to conventional solution-based methods. The advantages of low reagent consumption, rapid result readout, limited equipment, and long-term storage make this platform sensitive and simple enough to use without specialized training in resource constrained settings. PMID:27113330

  17. Formation of Copper Zinc Tin Sulfide Thin Films from Colloidal Nanocrystal Dispersions via Aerosol-Jet Printing and Compaction.

    PubMed

    Williams, Bryce A; Mahajan, Ankit; Smeaton, Michelle A; Holgate, Collin S; Aydil, Eray S; Francis, Lorraine F

    2015-06-01

    A three-step method to create dense polycrystalline semiconductor thin films from nanocrystal liquid dispersions is described. First, suitable substrates are coated with nanocrystals using aerosol-jet printing. Second, the porous nanocrystal coatings are compacted using a weighted roller or a hydraulic press to increase the coating density. Finally, the resulting coating is annealed for grain growth. The approach is demonstrated for making polycrystalline films of copper zinc tin sulfide (CZTS), a new solar absorber composed of earth-abundant elements. The range of coating morphologies accessible through aerosol-jet printing is examined and their formation mechanisms are revealed. Crack-free albeit porous films are obtained if most of the solvent in the aerosolized dispersion droplets containing the nanocrystals evaporates before they impinge on the substrate. In this case, nanocrystals agglomerate in flight and arrive at the substrate as solid spherical agglomerates. These porous coatings are mechanically compacted, and the density of the coating increases with compaction pressure. Dense coatings annealed in sulfur produce large-grain (>1 μm) polycrystalline CZTS films with microstructure suitable for thin-film solar cells. PMID:25989610

  18. Effect of Copper Sulfide Nanoparticles on the Optical and Electrical Behavior of Poly(vinyl alcohol) Films

    NASA Astrophysics Data System (ADS)

    Abdullah, Omed Gh.; Saleem, Salwan A.

    2016-07-01

    Polymer nanocomposite films based on poly(vinyl alcohol) (PVA) containing copper sulfide nanoparticles (CuS) were prepared using in situ chemical reduction and casting techniques. The synthesized nanocomposites were analyzed using x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope, and ultraviolet-visible spectroscopy. The XRD pattern reveals that the CuS nanoparticles incorporated in the PVA showed a crystalline nature. The observed FTIR band shifts indicate the intermolecular interaction between the CuS nanoparticles and the PVA matrix. The absorbance of nanocomposite samples increased with increasing CuS concentration. The optical band gap energy was estimated using Tauc's formula and it decreased with increasing dopant concentration. The conductivity and dielectric behavior of the samples were studied over the frequency range of 300 Hz to 1 MHz in the temperature range of 30-110°C. The ac conductivity was found to increase with the increase of dopant concentration as well as frequency. Moreover, the variation of frequency exponent (s) indicated that the conduction mechanism was the correlated barrier hopping model. The experimental results reveal that the optical and electrical performance of PVA can be enhanced dramatically by the addition of a small amount of CuS nanoparticles. This improved properties of the PVA/CuS nanocomposite suggest uses in optoelectronic devices.

  19. Facile fabrication of novel porous graphitic carbon nitride/copper sulfide nanocomposites with enhanced visible light driven photocatalytic performance.

    PubMed

    Chen, Xi; Li, Huankun; Wu, Yuxin; Wu, Hanshuo; Wu, Laidi; Tan, Pengfei; Pan, Jun; Xiong, Xiang

    2016-08-15

    In this work, a novel organic-inorganic heterostructured photocatalyst: porous graphitic carbon nitride (g-C3N4) hybrid with copper sulfide (CuS) had been synthesized via a precipitation-deposition method at low temperature for the first time. UV-vis spectroscopy revealed the porous g-C3N4/CuS nanocomposites showed a strong and broad visible light absorption. Furthermore, the g-C3N4/CuS nanocomposites showed higher photocatalytic activity in the photodegradation of various organic dyes than that of pure g-C3N4 and CuS, and the selected sample of g-C3N4/CuS-2 exhibited the best photocatalytic activity under visible light. The good photocatalytic activity could be ascribed to the matching of the g-C3N4 and CuS band gap energies. Besides, photoluminescent spectra and photoelectrochemical measurements also proved that the CuS/g-C3N4 could greatly enhance the charge generation and suppress the charge recombination of photogenerated carriers. According to the experimental result, a possible photocatalytic mechanism has been proposed. Due to the high stability, the porous g-C3N4/CuS could be applied in the field of environmental remediation. Our work highlights that coupling semiconductors with well-matched band energies provides a facile way to improve the photocatalytic activity. PMID:27209398

  20. Size-tunable copper nanocluster aggregates and their application in hydrogen sulfide sensing on paper-based devices

    NASA Astrophysics Data System (ADS)

    Chen, Po-Cheng; Li, Yu-Chi; Ma, Jia-Yin; Huang, Jia-Yu; Chen, Chien-Fu; Chang, Huan-Tsung

    2016-04-01

    Polystyrene sulfonate (PSS), a strong polyelectrolyte, was used to prepare red photoluminescent PSS-penicillamine (PA) copper (Cu) nanoclusters (NC) aggregates, which displayed high selectivity and sensitivity to the detection of hydrogen sulfide (H2S). The size of the PSS-PA-Cu NC aggregates could be readily controlled from 5.5 μm to 173 nm using different concentrations of PSS, which enabled better dispersity and higher sensitivity towards H2S. PSS-PA-Cu NC aggregates provided rapid H2S detection by using the strong Cu-S interaction to quench NC photoluminescence as a sensing mechanism. As a result, a detection limit of 650 nM, which is lower than the maximum level permitted in drinking water by the World Health Organization, was achieved for the analysis of H2S in spring-water samples. Moreover, highly dispersed PSS-PA-Cu NC aggregates could be incorporated into a plate-format paper-based analytical device which enables ultra-low sample volumes (5 μL) and feature shorter analysis times (30 min) compared to conventional solution-based methods. The advantages of low reagent consumption, rapid result readout, limited equipment, and long-term storage make this platform sensitive and simple enough to use without specialized training in resource constrained settings.

  1. Size-tunable copper nanocluster aggregates and their application in hydrogen sulfide sensing on paper-based devices.

    PubMed

    Chen, Po-Cheng; Li, Yu-Chi; Ma, Jia-Yin; Huang, Jia-Yu; Chen, Chien-Fu; Chang, Huan-Tsung

    2016-01-01

    Polystyrene sulfonate (PSS), a strong polyelectrolyte, was used to prepare red photoluminescent PSS-penicillamine (PA) copper (Cu) nanoclusters (NC) aggregates, which displayed high selectivity and sensitivity to the detection of hydrogen sulfide (H2S). The size of the PSS-PA-Cu NC aggregates could be readily controlled from 5.5 μm to 173 nm using different concentrations of PSS, which enabled better dispersity and higher sensitivity towards H2S. PSS-PA-Cu NC aggregates provided rapid H2S detection by using the strong Cu-S interaction to quench NC photoluminescence as a sensing mechanism. As a result, a detection limit of 650 nM, which is lower than the maximum level permitted in drinking water by the World Health Organization, was achieved for the analysis of H2S in spring-water samples. Moreover, highly dispersed PSS-PA-Cu NC aggregates could be incorporated into a plate-format paper-based analytical device which enables ultra-low sample volumes (5 μL) and feature shorter analysis times (30 min) compared to conventional solution-based methods. The advantages of low reagent consumption, rapid result readout, limited equipment, and long-term storage make this platform sensitive and simple enough to use without specialized training in resource constrained settings. PMID:27113330

  2. Light-induced cation exchange for copper sulfide based CO2 reduction.

    PubMed

    Manzi, Aurora; Simon, Thomas; Sonnleitner, Clemens; Döblinger, Markus; Wyrwich, Regina; Stern, Omar; Stolarczyk, Jacek K; Feldmann, Jochen

    2015-11-11

    Copper(I)-based catalysts, such as Cu2S, are considered to be very promising materials for photocatalytic CO2 reduction. A common synthesis route for Cu2S via cation exchange from CdS nanocrystals requires Cu(I) precursors, organic solvents, and neutral atmosphere, but these conditions are not compatible with in situ applications in photocatalysis. Here we propose a novel cation exchange reaction that takes advantage of the reducing potential of photoexcited electrons in the conduction band of CdS and proceeds with Cu(II) precursors in an aqueous environment and under aerobic conditions. We show that the synthesized Cu2S photocatalyst can be efficiently used for the reduction of CO2 to carbon monoxide and methane, achieving formation rates of 3.02 and 0.13 μmol h(-1) g(-1), respectively, and suppressing competing water reduction. The process opens new pathways for the preparation of new efficient photocatalysts from readily available nanostructured templates. PMID:26479775

  3. Low-temperature approach to highly emissive copper indium sulfide colloidal nanocrystals and their bioimaging applications.

    PubMed

    Yu, Kui; Ng, Peter; Ouyang, Jianying; Zaman, Md Badruz; Abulrob, Abedelnasser; Baral, Toya Nath; Fatehi, Dorothy; Jakubek, Zygmunt J; Kingston, David; Wu, Xiaohua; Liu, Xiangyang; Hebert, Charlie; Leek, Donald M; Whitfield, Dennis M

    2013-04-24

    We report our newly developed low-temperature synthesis of colloidal photoluminescent (PL) CuInS2 nanocrystals (NCs) and their in vitro and in vivo imaging applications. With diphenylphosphine sulphide (SDPP) as a S precursor made from elemental S and diphenylphosphine, this is a noninjection based approach in 1-dodecanethiol (DDT) with excellent synthetic reproducibility and large-scale capability. For a typical synthesis with copper iodide (CuI) as a Cu source and indium acetate (In(OAc)3) as an In source, the growth temperature was as low as 160 °C and the feed molar ratios were 1Cu-to-1In-to-4S. Amazingly, the resulting CuInS2 NCs in toluene exhibit quantum yield (QY) of ~23% with photoemission peaking at ~760 nm and full width at half maximum (FWHM) of ~140 nm. With a mean size of ~3.4 nm (measured from the vertices to the bases of the pyramids), they are pyramidal in shape with a crystal structure of tetragonal chalcopyrite. In situ (31)P NMR (monitored from 30 °C to 100 °C) and in situ absorption at 80 °C suggested that the Cu precursor should be less reactive toward SDPP than the In precursor. For our in vitro and in vivo imaging applications, CuInS2/ZnS core-shell QDs were synthesized; afterwards, dihydrolipoic acid (DHLA) or 11-mercaptoundecanoic acid (MUA) were used for ligand exchange and then bio-conjugation was performed. Two single-domain antibodies (sdAbs) were used. One was 2A3 for in vitro imaging of BxPC3 pancreatic cancer cells. The other was EG2 for in vivo imaging of a Glioblastoma U87MG brain tumour model. The bioimaging data illustrate that the CuInS2 NCs from our SDPP-based low-temperature noninjection approach are good quality. PMID:23486927

  4. A Comparative Study of Hollow Copper Sulfide Nanoparticles and Hollow Gold Nanospheres on Degradability and Toxicity

    PubMed Central

    Guo, Liangran; Panderi, Irene; Yan, Daisy D.; Szulak, Kevin; Li, Yajuan; Chen, Yi-Tzai; Ma, Hang; Niesen, Daniel B.; Seeram, Navindra; Ahmed, Aftab; Yan, Bingfang; Pantazatos, Dionysios; Lu, Wei

    2013-01-01

    Gold and copper nanoparticles have been widely investigated for photothermal therapy of cancer. However, degradability and toxicity of these nanoparticles remain concerns. Here, we compare hollow CuS nanoparticles (HCuSNPs) with hollow gold nanospheres (HAuNS) in similar particle sizes and morphology following intravenous administration to mice. The injected pegylated HCuSNPs (PEG-HCuSNPs) are eliminated through both hepatobiliary (67 percentage of injected dose, %ID) and renal (23 %ID) excretion within one month post injection. By contrast, 3.98 %ID of Au is excreted from liver and kidney within one month after i.v. injection of pegylated HAuNS (PEG-HAuNS). Comparatively, PEG-HAuNS are almost non-metabolizable, while PEG-HCuSNPs are considered biodegradable nanoparticles. PEG-HCuSNPs do not show significant toxicity by histological or blood chemistry analysis. Principal component analysis and 2-D peak distribution plots of data from matrix-assisted laser desorption ionization-time of flight imaging mass spectrometry (MALDI-TOF IMS) of liver tissues demonstrated a reversible change in the proteomic profile in mice receiving PEG-HCuSNPs. This is attributed to slow dissociation of Cu ion from CuS nanoparticles along with effective Cu elimination for maintaining homeostasis. Nonetheless, an irreversible change in the proteomic profile is observed in the liver from mice receiving PEG-HAuNS by analysis of MALDI-TOF IMS data, probably due to the non-metabolizability of Au. This finding correlates with the elevated serum lactate dehydrogenase at 3 months after PEG-HAuNS injection, indicating potential long-term toxicity. The comparative results between the two types of nanoparticles will advance the development of HCuSNPs as a new class of biodegradable inorganic nanomaterials for photothermal therapy. PMID:24053214

  5. Synthesis and Characterization of Phase-pure Copper Zinc Tin Sulfide (Cu2ZnSnS4) Nanoparticles

    NASA Astrophysics Data System (ADS)

    Monahan, Bradley Michael

    Semiconductor nanoparticles have been an important area of research in many different disciplines. A substantial amount of this work has been put toward advancing the field of photovoltaics. However, current p-type photovoltaic materials can not sustain the large scale production needed for future energy demands due to their low elemental abundance. Therefore, Earth abundant semiconductor materials have become of great interest to the photovoltaic community especially, the material copper zinc tin sulfide (CZTS), also known by its mineral name kesterite. CZTS exhibits desirable properties for photovoltaics, such as elemental abundance, high absorption coefficient (~104 cm-1 ), high carrier concentration, and optimum direct band gap (1.5 eV). To date, solution based approaches for making CZTS have yielded the most promising conversion efficiencies in solar cells. To that end, the motivation of nanoparticle based inks that can be used in high throughput production are an attractive route for large scale deployment. This has driven the need to make high quality CZTS nanoparticles that possess the properties of the pure kesterite phase with high monodispersity that can be deposited into dense thin films. The inherent challenge of making a quaternary compound of a single phase has made this a difficult task; however, some of those fundamental problems are addressed in this thesis. This had resulted in the synthesis of phase-pure k-CZTS confirmed by powder X-ray diffraction, Raman spectroscopy, UV-visible absorption spectroscopy and energy dispersive x-ray spectroscopy. Furthermore, ultra-fast laser spectroscopy was done on CZTS thin films made from phase-pure kesterite nanoparticles synthesized in this work. This thesis provides new data that directly probes the lifetime of photogenerated free carriers in kesterite CZTS (k-CZTS) thin films.

  6. Reaction Mechanisms of Metals with Hydrogen Sulfide and Thiols in Model Wine. Part 2: Iron- and Copper-Catalyzed Oxidation.

    PubMed

    Kreitman, Gal Y; Danilewicz, John C; Jeffery, David W; Elias, Ryan J

    2016-05-25

    Sulfidic off-odors arising during wine production are frequently removed by Cu(II) fining. In part 1 of this study ( 10.1021/acs.jafc.6b00641 ), the reaction of H2S and thiols with Cu(II) was examined; however, the interaction of iron and copper is also known to play an important synergistic role in mediating non-enzymatic wine oxidation. The interaction of these two metals in the oxidation of H2S and thiols (cysteine, 3-sulfanylhexan-1-ol, and 6-sulfanylhexan-1-ol) was therefore examined under wine-like conditions. H2S and thiols (300 μM) were reacted with Fe(III) (100 or 200 μM) alone and in combination with Cu(II) (25 or 50 μM), and concentrations of H2S and thiols, oxygen, and acetaldehyde were monitored over time. H2S and thiols were shown to be slowly oxidized in the presence of Fe(III) alone and were not bound to Fe(III) under model wine conditions. However, Cu(II) added to model wine containing Fe(III) was quickly reduced by H2S and thiols to form Cu(I) complexes, which then rapidly reduced Fe(III) to Fe(II). Oxidation of Fe(II) in the presence of oxygen regenerated Fe(III) and completed the iron redox cycle. In addition, sulfur-derived oxidation products were observed, and the formation of organic polysulfanes was demonstrated. PMID:27133088

  7. Study of the Susceptibility of Oxygen-Free Phosphorous Doped Copper to Corrosion in Simulated Groundwater in the Presence of Chloride and Sulfide

    SciTech Connect

    Escobar, Ivan; Lamas, Claudia; Werme, Lars |; Oversby, Virginia

    2007-07-01

    Oxygen free high conductivity copper, doped with phosphorus (Cu OFP) has been chosen as the material for the fabrication of high level nuclear waste containers in Sweden. This material will be the corrosion barrier for spent fuel in the environment of a deep geological repository in granitic rock. The service life of this container is expected to exceed 1,000,000 years. During this time, which includes several glaciations, water of different compositions, including high concentration of chloride ions, will contact the copper surface. This work reports a study of the susceptibility of Cu OFP to corrosion when chloride ions are present, in deionized water (DW) and in synthetic groundwater (SGW). The techniques used were electrochemical methods such as corrosion potential evolution and Tafel curves. The system was studied with Electrochemical Impedance Spectroscopy (EIS). We also used as characterization techniques Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). The main conclusions are that copper is more susceptible to corrosion at high chloride ion concentration. When the chloride concentration is low, it is possible to form copper chloride crystals, but at the highest concentration, copper chloride complexes are formed, leaving the copper surface without deposits. When the chloride concentration is low (<0.1 M) the corrosion process is mainly controlled by diffusion, while at higher concentrations (0.1 M to 1 M) corrosion is controlled by charge transfer processes. At low concentration of sulfide (<3 . 10{sup -5} M), copper corrosion in the presence of chloride is controlled by diffusional processes, while at higher concentrations corrosion is controlled by charge transfer processes. (authors)

  8. Evolution of 3-mercaptohexanol, hydrogen sulfide, and methyl mercaptan during bottle storage of Sauvignon blanc wines. Effect of glutathione, copper, oxygen exposure, and closure-derived oxygen.

    PubMed

    Ugliano, Maurizio; Kwiatkowski, Mariola; Vidal, Stéphane; Capone, Dimitra; Siebert, Tracey; Dieval, Jean-Baptiste; Aagaard, Olav; Waters, Elizabeth J

    2011-03-23

    The effects of wine composition and postbottling oxygen exposure on 3-mercaptohexanol (3-MH), hydrogen sulfide (H2S), and methyl mercaptan (MeSH) were investigated. A Sauvignon blanc wine with initial copper concentration of 0.1 mg/L was treated with copper sulfate and/or glutathione (GSH) prior to bottling to give final concentrations of 0.3 and 20 mg/L, respectively. The wines were bottled with a synthetic closure previously stored in either ambient air or nitrogen to study the effect of the oxygen normally present in the closure. Bottled wines were stored for 6 months in either air or nitrogen to study the effect of oxygen ingress through the closure. Copper addition resulted in a rapid initial decrease in 3-MH. During storage, a further decrease of 3-MH was observed, which was lower with GSH addition and lowered oxygen exposure. H2S accumulated largely during the second 3 months of bottle storage, with the highest concentrations attained in the wines treated with GSH and copper. Lower oxygen from and through the closure promoted H2S accumulation. The concentration of MeSH was virtually not affected by the experimental variables at 6 months, although differences were observed after 3 months of storage. The implications for wine quality are discussed. PMID:21332202

  9. Petrography, sulfide mineral chemistry, and sulfur isotope evidence for a hydrothermal imprint on Musina copper deposits, Limpopo Province, South Africa: Evidence for a breccia pipe origin?

    NASA Astrophysics Data System (ADS)

    Chaumba, Jeff B.; Mundalamo, Humbulani R.; Ogola, Jason S.; Cox, J. A.; Fleisher, C. J.

    2016-08-01

    The Musina copper deposits are located in the Central Zone of the Limpopo orogenic belt in Limpopo Province, South Africa. We carried out a petrographic, sulfide composition, and δ34S study on samples from Artonvilla and Campbell copper deposits and a country rock granitic gneiss to Artonvilla Mine to place some constrains on the origin of these deposits. The assemblages at both Artonvilla and Campbell Mines of brecciated quartz, potassium feldspar, muscovite, chlorite, calcite, and amphibole are consistent with sericitic alteration. Quartz, amphibole, feldspars, and micas often display angular textures which are consistent with breccias. Sulfur concentrations in pyrite from Artonvilla Mine plot in a narrow range, from 50.2 wt. % to 55.7 wt. %. With the exception of a positive correlation between Fe and Cu, no well defined correlations are shown by data from the Musina copper deposits. The occurrence of sulfides both as inclusions in, or as interstitial phases in silicates, suggests that hydrothermal alteration that affected these deposits most likely helped concentrate the mineralization at the Musina copper deposits. Sulfur concentrations in chalcopyrite samples investigated vary widely whereas the copper concentrations in chalcopyrite are not unusually higher compared to those from chalcopyrite from other tectonic settings, probably indicating that either the Cu in the Musina copper deposits occurs in native form, and/or that it is hosted by other phases. This observation lends support to the Cu having been concentrated during a later hydrothermal event. One sample from Artonvilla Mine (AtCal01) yielded pyrite δ34S values of 3.1and 3.6‰ and chalcopyrite from the same sample yielded a value of 3.9‰. A country rock granitic gneiss to Artonvilla Mine yielded a δ34Spyrite value of 8.2‰. For Campbell Mine samples, one quartz vein sample has a δ34Spyrite value of 0.5‰ whereas chalcopyrite samples drilled from different areas within the same sample

  10. COPPER

    EPA Science Inventory

    The report is a review of current knowledge of the distribution of copper in the environment and living things. Metabolism and the effects of copper in the biosphere are also considered. Copper compounds are common and widely distributed in nature. They are also extensively mined...

  11. Cu1.94S-Assisted Growth of Wurtzite CuInS2 Nanoleaves by In Situ Copper Sulfidation.

    PubMed

    Cai, Chunqi; Zhai, Lanlan; Zou, Chao; Li, Zhensong; Zhang, Lijie; Yang, Yun; Huang, Shaoming

    2015-12-01

    Wurtzite CuInS2 nanoleaves were synthesized by Cu1.94S-assisted growth. By observing the evolution of structures and phases during the growth process, Cu1.94S nanocrystals were found to be formed after uninterrupted oxidation and sulfidation of copper nanoparticles at the early stage, serving as catalysts to introduce the Cu and In species into CuInS2 nanoleaves growth for inherent property of fast ionic conductor. The obtained CuInS2 nanoleaves were characterized by scanning transmission electron microscopy, transmission electron microscopy, fast Fourier transform, X-ray diffraction, and energy dispersive X-ray spectroscopy mapping. The enhancement of photoresponsive current of CuInS2 nanoleaf film, evaluated by I-V curves of nanoleaf film, is believed to be attributed to the fast carrier transport benefit from the nature of single crystalline of CuInS2 nanoleaves. PMID:26173675

  12. Removal of copper from ferrous scrap

    DOEpatents

    Blander, M.; Sinha, S.N.

    1990-05-15

    A process for removing copper from ferrous or other metal scrap in which the scrap is contacted with a polyvalent metal sulfide slag in the presence of an excess of copper-sulfide forming additive to convert the copper to copper sulfide which is extracted into the slag to provide a ratio of copper in the slag to copper in the metal scrap of at least about 10.

  13. Removal of copper from ferrous scrap

    DOEpatents

    Blander, Milton; Sinha, Shome N.

    1990-01-01

    A process for removing copper from ferrous or other metal scrap in which the scrap is contacted with a polyvalent metal sulfide slag in the presence of an excess of copper-sulfide forming additive to convert the copper to copper sulfide which is extracted into the slag to provide a ratio of copper in the slag to copper in the metal scrap of at least about 10.

  14. Removal of copper from ferrous scrap

    DOEpatents

    Blander, M.; Sinha, S.N.

    1987-07-30

    A process for removing copper from ferrous or other metal scrap in which the scrap is contacted with a polyvalent metal sulfide slag in the presence of an excess of copper-sulfide forming additive to convert the copper to copper sulfide which is extracted into the slag to provide a ratio of copper in the slag to copper in the metal scrap of at least about 10.

  15. Facile room-temperature synthesis of carboxylated graphene oxide-copper sulfide nanocomposite with high photodegradation and disinfection activities under solar light irradiation

    PubMed Central

    Yu, Shuyan; Liu, Jincheng; Zhu, Wenyu; Hu, Zhong-Ting; Lim, Teik-Thye; Yan, Xiaoli

    2015-01-01

    Carboxylic acid functionalized graphene oxide-copper (II) sulfide nanoparticle composite (GO-COOH-CuS) was prepared from carboxylated graphene oxide and copper precursor in dimethyl sulfoxide (DMSO) by a facile synthesis process at room temperature. The high-effective combination, the interaction between GO-COOH sheets and CuS nanoparticles, and the enhanced visible light absorption were confirmed by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectra (DRS) and Photoluminescence (PL) spectra. The as-synthesized GO-COOH-CuS nanocomposite exhibited excellent photocatalytic degradation performance of phenol and rhodamine B, high antibacterial activity toward E. coli and B. subtilis, and good recovery and reusability. The influence of CuS content, the synergistic reaction between CuS and GO-COOH, and the charge-transfer mechanism were systematically investigated. The facile and low-energy synthesis process combined with the excellent degradation and antibacterial performance signify that the GO-COOH-CuS has a great potential for water treatment application. PMID:26553709

  16. Facile room-temperature synthesis of carboxylated graphene oxide-copper sulfide nanocomposite with high photodegradation and disinfection activities under solar light irradiation.

    PubMed

    Yu, Shuyan; Liu, Jincheng; Zhu, Wenyu; Hu, Zhong-Ting; Lim, Teik-Thye; Yan, Xiaoli

    2015-01-01

    Carboxylic acid functionalized graphene oxide-copper (II) sulfide nanoparticle composite (GO-COOH-CuS) was prepared from carboxylated graphene oxide and copper precursor in dimethyl sulfoxide (DMSO) by a facile synthesis process at room temperature. The high-effective combination, the interaction between GO-COOH sheets and CuS nanoparticles, and the enhanced visible light absorption were confirmed by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectra (DRS) and Photoluminescence (PL) spectra. The as-synthesized GO-COOH-CuS nanocomposite exhibited excellent photocatalytic degradation performance of phenol and rhodamine B, high antibacterial activity toward E. coli and B. subtilis, and good recovery and reusability. The influence of CuS content, the synergistic reaction between CuS and GO-COOH, and the charge-transfer mechanism were systematically investigated. The facile and low-energy synthesis process combined with the excellent degradation and antibacterial performance signify that the GO-COOH-CuS has a great potential for water treatment application. PMID:26553709

  17. Facile room-temperature synthesis of carboxylated graphene oxide-copper sulfide nanocomposite with high photodegradation and disinfection activities under solar light irradiation

    NASA Astrophysics Data System (ADS)

    Yu, Shuyan; Liu, Jincheng; Zhu, Wenyu; Hu, Zhong-Ting; Lim, Teik-Thye; Yan, Xiaoli

    2015-11-01

    Carboxylic acid functionalized graphene oxide-copper (II) sulfide nanoparticle composite (GO-COOH-CuS) was prepared from carboxylated graphene oxide and copper precursor in dimethyl sulfoxide (DMSO) by a facile synthesis process at room temperature. The high-effective combination, the interaction between GO-COOH sheets and CuS nanoparticles, and the enhanced visible light absorption were confirmed by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectra (DRS) and Photoluminescence (PL) spectra. The as-synthesized GO-COOH-CuS nanocomposite exhibited excellent photocatalytic degradation performance of phenol and rhodamine B, high antibacterial activity toward E. coli and B. subtilis, and good recovery and reusability. The influence of CuS content, the synergistic reaction between CuS and GO-COOH, and the charge-transfer mechanism were systematically investigated. The facile and low-energy synthesis process combined with the excellent degradation and antibacterial performance signify that the GO-COOH-CuS has a great potential for water treatment application.

  18. Temperature-dependent formation of metallic copper and metal sulfide nanoparticles during flooding of a contaminated soil

    NASA Astrophysics Data System (ADS)

    Hofacker, Anke F.; Voegelin, Andreas; Kaegi, Ralf; Weber, Frank-Andreas; Kretzschmar, Ruben

    2013-02-01

    Riparian floodplains in temperate regions are affected by pronounced seasonal variations in soil and water temperature. This affects the rates and interplay of microbial and abiotic geochemical processes that control the fate of metals in contaminated floodplain soils, including potential release into surface and groundwater during periodic flooding. Here, we investigated how temperature affects chalcophile trace metal contaminants (Cu, Cd, Pb) upon flooding of a riparian soil contaminated by past mining activities. In soil microcosms incubated at 23, 14, and 5 °C, the reductive dissolution of Mn(III,IV) and Fe(III) (oxyhydr)oxides and the release of dissolved Mn2+ and Fe2+ were significantly slower and less intense at the lower temperatures, which was reflected in a decrease of trace metal mobilization via the dissolution of metal oxide sorbents and cation competition for sorption sites. The onset of sulfate reduction was significantly delayed at lower temperatures and the apparent rate of sulfate reduction was decreased, especially at 5 °C. This resulted in elevated high dissolved Cu, Cd, and Pb concentrations over weeks of flooding at 5 °C, whereas colloidal metal sulfide formation dominated Cu, Cd, and Pb pore water dynamics at higher temperatures of 14 and 23 °C due to fast sulfate reduction. Cu K-edge X-ray absorption fine structure spectroscopy revealed metallic Cu(0) as the main colloidal Cu species prior to sulfate reduction at all three temperatures. Analytical electron microscopy showed that Cu(0) particles were associated with suspended bacteria, suggesting biomineralization of Cu(0). Upon onset of sulfate reduction, metallic Cu particles were transformed into CuxS with incorporation of smaller amounts of Cd and Pb. Concomitantly, freely dispersed mixed Cu-Cd-Pb sulfide nanoparticles precipitated in the pore water. Other metals with higher metal sulfide solubility products did not react with the limited amounts of biogenic sulfide. The median size

  19. Photocatalytic Activities of Copper Doped Cadmium Sulfide Microspheres Prepared by a Facile Ultrasonic Spray-Pyrolysis Method.

    PubMed

    Su, Jinzhan; Zhang, Tao; Li, Yufeng; Chen, Yubin; Liu, Maochang

    2016-01-01

    Ultrasonic spray pyrolysis is a superior method for preparing and synthesizing spherical particles of metal oxide or sulfide semiconductors. Cadmium sulfide (CdS) photocatalysts with different sizes and doped-CdS with different dopants and doping levels have been synthesized to study their properties of photocatalytic hydrogen production from water. The CdS photocatalysts were characterized with scanning electron microscopy (SEM), X-ray fluorescence-spectrometry (XRF), UV-Vis absorption spectra and X-ray diffraction (XRD) to study their morphological and optical properties. The sizes of the prepared CdS particles were found to be proportional to the concentration of the metal nitrates in the solution. The CdS photocatalyst with smaller size showed a better photocatalytic activity. In addition, Cu doped CdS were also deposited and their photocatalytic activities were also investigated. Decreased bandgaps of CdS synthesized with this method were found and could be due to high density surface defects originated from Cd vacancies. Incorporating the Cu elements increased the bandgap by taking the position of Cd vacancies and reducing the surface defect states. The optimal Cu-doped level was found to be 0.5 mol % toward hydrogen evolution from aqueous media in the presence of sacrificial electron donors (Na₂S and Na₂SO₃) at a pH of 13.2. This study demonstrated that ultrasonic spray pyrolysis is a feasible approach for large-scale photocatalyst synthesis and corresponding doping modification. PMID:27314320

  20. High color rendering index white light emitting diodes fabricated from a combination of carbon dots and zinc copper indium sulfide quantum dots

    SciTech Connect

    Sun, Chun; Liu, Wenyan; Zhang, Xiaoyu; Zhang, Yu E-mail: wyu6000@gmail.com; Wang, Yu; Kalytchuk, Sergii; Kershaw, Stephen V.; Rogach, Andrey L.; Zhang, Tieqiang; Zhao, Jun; Yu, William W. E-mail: wyu6000@gmail.com

    2014-06-30

    In a line with most recent trends in developing non-toxic fluorescent nanomaterials, we combined blue emissive carbon dots with green and red emissive zinc copper indium sulfide (ZCIS) core/shell quantum dots (QDs) to achieve white light-emitting diodes (WLEDs) with a high color rendering index of 93. This indicates that ZCIS QDs, with their broad emission bands, can be employed to effectively make up the emission of carbon dots in the yellow and red regions to produce WLEDs in the wide region of color temperature by tuning the volume ratio of these constituting luminophores. Their electroluminescence characteristics including color rendering index, Commission Internationale de l'Eclairage (CIE) color coordinates, and color temperatures were evaluated as a function of forward current. The CIE-1931 chromaticity coordinates of the as-prepared WLEDs, exhibiting good stability, were slightly shifted from (0.321, 0.312) at 10 mA to (0.351, 0.322) at 30 mA, which was mainly caused by the different thermal quenching coefficients of carbon dots and ZCIS QDs.

  1. An efficient dual-loaded multifunctional nanocarrier for combined photothermal and photodynamic therapy based on copper sulfide and chlorin e6.

    PubMed

    Tan, Xiaoxiao; Pang, Xiaojuan; Lei, Mingzhu; Ma, Man; Guo, Fang; Wang, Jinping; Yu, Meng; Tan, Fengping; Li, Nan

    2016-04-30

    The therapeutic effectiveness of photodynamic therapy (PDT) was hampered by the poor water solubility and instability in physiological conditions of the photosensitizers. Here, we designed folate conjugated thermosensitive liposomes (TSL) as the nanocarrier to improve the solubility, stability and biocompatibility of photosensitizer Chlorin e6 (Ce6). Based on the photothermal effect, we combined copper sulfide (CuS) as the photothermal agent to realize heat-triggered Ce6 release as well as synergistic effect of photothermal and photodynamic therapy. In vitro MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay showed that Ce6-CuS-TSL had low dark toxicity, while performed excellent phototoxicity under the combined 660 and 808nm laser irradiation compared to any single laser irradiation alone. Moreover, in vivo combination therapy study revealed that Ce6-CuS-TSL inhibited tumor growth to a great extent without evident side effect under the laser irradiation. All detailed evidence demonstrated a considerable potential of Ce6-CuS-TSL for synergistic cancer treatment. PMID:26988376

  2. Copper

    Integrated Risk Information System (IRIS)

    Copper ; CASRN 7440 - 50 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects )

  3. Fluorescence signaling of hydrogen sulfide in broad pH range using a copper complex based on BINOL-benzimidazole ligands.

    PubMed

    Sun, Mingtai; Yu, Huan; Li, Huihui; Xu, Hongda; Huang, Dejian; Wang, Suhua

    2015-04-20

    A weakly fluorescent complex derived from a binaphthol-benzimidazole ligand was designed and synthesized for hydrogen sulfide at different pH conditions. It was demonstrated that the probe showed the same reactivity to various hydrogen sulfide species in a broad range of pH values to generate highly fluorescent product through a displacement reaction mechanism, whereas the product's fluorescence spectrum exhibited a hypsochromic shift of ∼73 nm (2393 cm(-1)) as pH increased from neutral to basic, which can be used for distinguishing the various species of hydrogen sulfide. This turn-on fluorescence probe was highly selective and sensitive to hydrogen sulfide with a detection limit of 0.11 μM. It was then applied for evaluating the total content of sulfide (including hydrogen sulfide, hydrosulfide, and sulfide) as well as for the visual detection of gaseous H2S in air using a simple test paper strip. PMID:25839192

  4. Selenium Sulfide

    MedlinePlus

    Selenium sulfide, an anti-infective agent, relieves itching and flaking of the scalp and removes the dry, ... Selenium sulfide comes in a lotion and is usually applied as a shampoo. As a shampoo, selenium ...

  5. Copper-doped silica materials silanized with bis-(triethoxy silyl propyl)-tetra sulfide for mercury vapor capture

    SciTech Connect

    D.E. Meyer; N. Meeks; S. Sikdar; N.D. Hutson; D. Hua; D. Bhattacharyya

    2008-07-15

    The use of Cu-S sites for Hg capture from the gas phase has been successfully applied to a silica-based platform using an S4 organic polysulfane and copper sulfate. The maximum fixed-bed equilibrium capacity achieved using these materials was 19 789 {mu}g Hg.g{sup -1} sorbent for a material with 2.5 wt % Cu and 6 wt % S. An optimal S level was determined to be around 3 wt % because enhancement of capacity was only 18% when increasing from this 3 to 6 wt %. The rate of adsorption in pure beds ranged from 0.6 to 1.6 {mu}g Hg.min{sup -1} depending on the inlet concentration. Differences in breakthrough times suggest that material deposition is not uniform. When compared to two other platforms, commercially available Darco HG-LH and previously tested Fe-Cu-S4 nanoaggregates, the Si-1 material performed the best in fixed-bed testing. During entrained-flow testing, a steady-state Hg removal of 82% was achieved using Si-1 at injection rates of both 6 x 10{sup -5} and 1.2 x 10{sup -4} g.L{sup -1}.h{sup -1}. The lack of increase in Hg removal when the injection rate is doubled suggests that pore accessibility is the rate-controlling step during dynamic Hg capture. A calculation of the approximate pore usage based on injection testing helped confirm this observation. During injection testing, the performance of Si-1 was only diminished 10% when exposed to 20 ppm SO{sub 3}. This is an encouraging result for flue-gas applications where SO{sub 3} levels range from 1 to 40 ppm. Testing demonstrated that Si-1 is stable when exposed to leaching conditions after concrete blending and cement impregnation. This is an important aspect to consider for injection because the sale of fly ash for concrete is a key cost-recovery tool for power plants. 27 refs., 8 figs., 5 tabs.

  6. Structural, optical and charge generation properties of chalcostibite and tetrahedrite copper antimony sulfide thin films prepared from metal xanthates† †Electronic supplementary information (ESI) available: Chemical structures of the used metal xanthates, additional XRD, SEM-EDX and UV-vis data. See DOI: 10.1039/c5ta05777a Click here for additional data file.

    PubMed Central

    MacLachlan, Andrew J.; Brown, Michael D.

    2015-01-01

    Herein, we report on a solution based approach for the preparation of thin films of copper antimony sulfide, an emerging absorber material for third generation solar cells. In this work, copper and antimony xanthates are used as precursor materials for the formation of two different copper antimony sulfide phases: chalcostibite (CuSbS2) and tetrahedrite (Cu12Sb4S13). Both phases were thoroughly investigated regarding their structural and optical properties. Moreover, thin films of chalcostibite and tetrahedrite were prepared on mesoporous TiO2 layers and photoinduced charge transfer in these metal sulfide/TiO2 heterojunctions was studied via transient absorption spectroscopy. Photoinduced charge transfer was detected in both the chalcostibite as well as the tetrahedrite sample, which is an essential property in view of applying these materials as light-harvesting agents in semiconductor sensitized solar cells. PMID:27019713

  7. Nanostructured metal sulfides for energy storage.

    PubMed

    Rui, Xianhong; Tan, Huiteng; Yan, Qingyu

    2014-09-01

    Advanced electrodes with a high energy density at high power are urgently needed for high-performance energy storage devices, including lithium-ion batteries (LIBs) and supercapacitors (SCs), to fulfil the requirements of future electrochemical power sources for applications such as in hybrid electric/plug-in-hybrid (HEV/PHEV) vehicles. Metal sulfides with unique physical and chemical properties, as well as high specific capacity/capacitance, which are typically multiple times higher than that of the carbon/graphite-based materials, are currently studied as promising electrode materials. However, the implementation of these sulfide electrodes in practical applications is hindered by their inferior rate performance and cycling stability. Nanostructures offering the advantages of high surface-to-volume ratios, favourable transport properties, and high freedom for the volume change upon ion insertion/extraction and other reactions, present an opportunity to build next-generation LIBs and SCs. Thus, the development of novel concepts in material research to achieve new nanostructures paves the way for improved electrochemical performance. Herein, we summarize recent advances in nanostructured metal sulfides, such as iron sulfides, copper sulfides, cobalt sulfides, nickel sulfides, manganese sulfides, molybdenum sulfides, tin sulfides, with zero-, one-, two-, and three-dimensional morphologies for LIB and SC applications. In addition, the recently emerged concept of incorporating conductive matrices, especially graphene, with metal sulfide nanomaterials will also be highlighted. Finally, some remarks are made on the challenges and perspectives for the future development of metal sulfide-based LIB and SC devices. PMID:25073046

  8. Selenium Sulfide

    MedlinePlus

    Selenium sulfide comes in a lotion and is usually applied as a shampoo. As a shampoo, selenium sulfide usually is used twice a week for the first ... it is irritating. Rinse off all of the lotion.Do not use this medication on children younger ...

  9. Hydrothermal ore-forming processes in the light of studies in rock- buffered systems: I. Iron-copper-zinc-lead sulfide solubility relations

    USGS Publications Warehouse

    Hemley, J.J.; Cygan, G.L.; Fein, J.B.; Robinson, G.R.; d'Angelo, W. M.

    1992-01-01

    Experimental studies, using cold-seal and extraction vessel techniques, were conducted on Fe, Pb, Zn, and Cu sulfide solubilities in chloride soultions at temperatures from 300?? to 700??C and pressures from 0.5 to 2 kbars. The solutions were buffered in pH by quartz monzonite and the pure potassium feldspar-muscovite-quartz assemblage and in fS2-fO2 largely by the assemblage pyrite-pyrrhotite-magnetite. Solubilities increase with increasing temperature and total chloride, and decrease with increasing pressure. The effect of increasing chloride concentration on solubility reflects primarily a shift to lower pH via the silicate buffer reactions. Similarity in behaviour with respect to the temperature and pressure of Fe, Zn, and Pb sulfide solubilities points to similarity in chloride speciation, and the neutral species appear to be dominant in the high-temperature region. -from Authors

  10. Crystal structure of poly[(μ3-thio­cyanato-κ3 N:S:S)(tri­methyl­phosphine sulfide-κS)copper(I)

    PubMed Central

    Corfield, Peter W. R.

    2014-01-01

    In the title compound, [Cu(NCS)(C3H9PS)]n, the thio­cyanate ions bind the CuI atoms covalently, forming infinite –Cu—SCN—Cu– chains parallel to the a axis. Each CuI atom is also coordinated to a tri­methyl­phosphine sulfide group via a Cu—S bond. Two crystallographically independent chains propagate in opposite directions, and are held together in a ribbon arrangement by long bonds between CuI atoms in the first chain and thio­cyanate S atoms in the second, with Cu—S = 2.621 (1) Å. The geometry around the CuI atoms in the first chain is distorted tetra­hedral, with angles involving the long Cu—S bond much less than ideal, and the S—Cu—N angle between the phosphine sulfide S atom and the thio­cyanate N atom opening out to 133.19 (9)°. Each CuI atom in the second chain appears to be disordered between two positions 0.524 (4) Å apart, with occupancy factors of 0.647 (6) and 0.353 (6). The CuI atom in the major site is in a distorted trigonal–planar configuration, with the S—Cu—N angle between the phosphine sulfide and the thio­cyanate N atom again opened out, to 137.01 (15)°. The CuI atom in the minor site, however, forms in addition a long bond [Cu—S = 2.702 (5) Å] to the phosphine sulfide of the first chain, not the thio­cyanate S atom, to provide a further link between the chains. PMID:25484723

  11. Copper-catalyzed C-H bond direct chalcogenation of aromatic compounds leading to diaryl sulfides, selenides, and diselenides by using elemental sulfur and selenium as chalcogen sources under oxidative conditions.

    PubMed

    Shibahara, Fumitoshi; Kanai, Takafumi; Yamaguchi, Eiji; Kamei, Akika; Yamauchi, Takayuki; Murai, Toshiaki

    2014-01-01

    The reactions of aromatic compounds and elemental chalcogens catalyzed by a copper salt with molecular oxygen as an oxidant were carried out. The reaction of 3-substituted imidazo[1,5-a]pyridines and elemental sulfur in the presence of CuTC (copper(I) thiophenecarboxylate) gave the corresponding bisimidazopyridyl sulfides in good to quantitative yields. The reaction proceeded even under aerobic oxidation conditions. The use of a polar solvent was crucial for the reaction, and DMSO (dimethyl sulfoxide) in particular stimulated the reaction. The reaction could be applied to common aromatic compounds, such as N-methyl indole and dialkyl anilines. The reaction of indole proceeded at the nucleophilic C3 position rather than at the acidic C2 position. In addition, the reaction of dialkyl anilines proceeded with an ortho, para orientation. The reactions of imidazopyridines and elemental selenium under similar conditions gave the corresponding bisimidazopyridyl diselenides along with bisimidazopyridyl monoselenides. The resulting diselenides were readily converted to the corresponding monoselenides with unreacted imidazopyridines under the same conditions. The reaction could be applied to the copolymerization of bifunctional bisimidazopyridines and elemental sulfur to give oligomeric copolymers in quantitative yield. PMID:24347073

  12. Selenium sulfide

    Integrated Risk Information System (IRIS)

    Selenium sulfide ; CASRN 7446 - 34 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  13. Hydrogen sulfide

    Integrated Risk Information System (IRIS)

    Hydrogen sulfide ; 7783 - 06 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effec

  14. Carbonyl sulfide

    Integrated Risk Information System (IRIS)

    Carbonyl sulfide ; CASRN 463 - 58 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  15. Sulfide clean-up of solutions from heavy metal ions

    SciTech Connect

    Kislinskaya, G.E.; Kozachek, N.N.; Krasnova, G.M.; Shenk, N.I.

    1982-09-20

    The object of the present research was to determine the conditions for thorough clean-up of solutions from cadmium or mercury contamination by use of iron sulfide. Results indicated that the shape of the dependence of the degree of extraction of copper with iron sulfide on the pH value is analogous to the curve for cadmium; that is, copper, like cadmium, is precipitated by chemical reaction. In distinction from cadmium and copper, mercury is extracted by iron sulfide both in acid and also in neutral solutions, that is, it is possible to attain a direct ion exchange by reaction. At high pH values, only small amounts of iron go into solution, therefore FeS can be used very rationally for the extraction of both small (about 1 mg/liter), and also of large (about 1 mg/liter) amounts of mercury from solutions, which are nearly neutral. By adding sodium sulfide and a flocculant, one can accelerate the process of mercury precipitation, and also reduce the solution of iron sulfide. In the present case, iron sulfide plays the role of a substrate for the crystallization of mercury sulfide, since in dilute solutions the latter forms poorly filterable colloidal solutions. Thus when one uses fused iron sulfide with addition of sodium sulfide, a high degree of mercury extraction is attained, and the spent sorbent is filtered well.

  16. Metallic sulfide additives for positive electrode material within a secondary electrochemical cell

    DOEpatents

    Walsh, William J.; McPheeters, Charles C.; Yao, Neng-ping; Koura, Kobuyuki

    1976-01-01

    An improved active material for use within the positive electrode of a secondary electrochemical cell includes a mixture of iron disulfide and a sulfide of a polyvalent metal. Various metal sulfides, particularly sulfides of cobalt, nickel, copper, cerium and manganese, are added in minor weight proportion in respect to iron disulfide for improving the electrode performance and reducing current collector requirements.

  17. Dynamic of active microorganisms inhabiting a bioleaching industrial heap of low‐grade copper sulfide ore monitored by real‐time PCR and oligonucleotide prokaryotic acidophile microarray

    PubMed Central

    Remonsellez, Francisco; Galleguillos, Felipe; Moreno‐Paz, Mercedes; Parro, Víctor; Acosta, Mauricio; Demergasso, Cecilia

    2009-01-01

    Summary The bioleaching of metal sulfide has developed into a very important industrial process and understanding the microbial dynamic is key to advancing commercial bioleaching operations. Here we report the first quantitative description of the dynamic of active communities in an industrial bioleaching heap. Acidithiobacillus ferrooxidans was the most abundant during the first part of the leaching cycle, while the abundance of Leptospirillum ferriphilum and Ferroplasma acidiphilum increased with age of the heap. Acidithiobacillus thiooxidans kept constant throughout the leaching cycle, and Firmicutes group showed a low and a patchy distribution in the heap. The Acidiphilium‐like bacteria reached their highest abundance corresponding to the amount of autotrophs. The active microorganisms in the leaching system were determined using two RNA‐based sensitive techniques. In most cases, the 16S rRNA copy numbers of At. ferrooxidans, L. ferriphilum, At. thiooxidans and F. acidiphilum, was concomitant with the DNA copy numbers, whereas Acidiphilium‐like bacteria and some Firmicutes members did not show a clear correlation between 16S rRNA accumulation and DNA copy numbers. However, the prokaryotic acidophile microarray (PAM) analysis showed active members of Alphaproteobacteria in all samples and of Sulfobacillus genus in older ones. Also, new active groups such as Actinobacteria and Acidobacterium genus were detected by PAM. The results suggest that changes during the leaching cycle in chemical and physical conditions, such as pH and Fe3+/Fe2+ ion rate, are primary factors shaping the microbial dynamic in the heap. PMID:21255296

  18. Scientific communications: Re-Os sulfide (bornite, chalcopyrite, and pyrite) systematics of the carbonate-hosted copper deposits at ruby creek, southern brooks range, Alaska

    USGS Publications Warehouse

    Selby, D.; Kelley, K.D.; Hitzman, M.W.; Zieg, J.

    2009-01-01

    New Re-Os data for chalcopyrite, bornite, and pyrite from the carbonate-hosted Cu deposit at Ruby Creek (Bornite), Alaska, show extremely high Re abundances (hundreds of ppb, low ppm) and contain essentially no common Os. The Re-Os data provide the first absolute ages of ore formation for the carbonate-hosted Ruby Creek Cu-(Co) deposit and demonstrate that the Re-Os systematics of pyrite, chalcopyrite, and bornite are unaffected by greenschist metamorphism. The Re-Os data show that the main phase of Cu mineralization pre dominantly occurred at 384 ?? 4.2 Ma, with an earlier phase possibly at ???400 Ma. The Re-Os data are consistent with the observed paragenetic sequence and coincide with zircon U-Pb ages from igneous rocks within the Ambler metallogenic belt, some of which are spatially and genetically associated with regional volcanogenic massive sulfide deposits. The latter may suggest a temporal link between regional magmatism and hydrothermal mineralization in the Ambler district. The utility of bornite and chalcopyrite, in addition to pyrite, contributes to a new understanding of Re-Os geochronology and permits a refinement of the genetic model for the Ruby Creek deposit. ?? 2009 Society of Economices Geologists, Inc.

  19. Effects of spatial and temporal variation of acid-volatile sulfide on the bioavailability of copper and zinc in freshwater sediments

    SciTech Connect

    Besser, J.M.; Ingersoll, C.G.; Giesy, J.P.

    1996-03-01

    Variation in concentrations of acid-volatile sulfide (AVS) in sediments from the upper Clark Fork River of Montana, USA, was associated with differences in bioaccumulation of Cu and Zn and growth of larvae of the midge, Chironomus tentans. Growth of midge larvae was significantly greater and bioaccumulation of Cu was significantly less in surface sections (0--3 cm depth) of sediment cores, which had greater concentrations of AVS and lesser ratios of simultaneously extracted metals to AVS (SEM:AVS ratios) than in subsurface sediments (6--9 cm). Concentrations of AVS were significantly less in sediments incubated with oxic overlying water for 9 weeks than in the same sediments incubated under anoxic conditions. Bioaccumulation of Cu differed significantly between incubation treatments, corresponding to differences in concentrations of AVS and SEM:AVS ratios, although midge growth did not. Bioaccumulation of Zn did not differ significantly between depth strata of sediment cores or between incubation treatments. When results from the two sets of bioassays were combined, bioaccumulation of Cu and Zn, but not growth, was significantly correlated with SEM:AVS ratios and other estimates of bioavailable metal fractions in sediments. Growth of midge larvae was significantly correlated with bioaccumulation of Zn, but not Cu, suggesting that Zn was the greater contributor to the toxicity of these sediments. Assessments of the toxicity of metal-contaminated freshwater sediments should consider the effects of spatial and temporal variation in AVS concentrations on metal bioavailability.

  20. Formation of selenide, sulfide or mixed selenide-sulfide films on metal or metal coated substrates

    DOEpatents

    Eser, Erten; Fields, Shannon

    2012-05-01

    A process and composition for preventing cracking in composite structures comprising a metal coated substrate and a selenide, sulfide or mixed selenide sulfide film. Specifically, cracking is prevented in the coating of molybdenum coated substrates upon which a copper, indium-gallium diselenide (CIGS) film is deposited. Cracking is inhibited by adding a Se passivating amount of oxygen to the Mo and limiting the amount of Se deposited on the Mo coating.

  1. Utilization of reduced graphene oxide/cadmium sulfide-modified carbon cloth for visible-light-prompt photoelectrochemical sensor for copper (II) ions.

    PubMed

    Foo, C Y; Lim, H N; Pandikumar, A; Huang, N M; Ng, Y H

    2016-03-01

    A newly developed CdS/rGO/CC electrode was prepared based on a flexible carbon cloth (CC) substrate with cadmium sulfide (CdS) nanoparticles and reduced graphene oxide (rGO). The CdS was synthesized using an aerosol-assisted chemical vapor deposition (AACVD) method, and the graphene oxide was thermally reduced on the modified electrode surface. The existence of rGO in the CdS-modified electrode increased the photocurrent intensity of the CdS/rGO/CC-modified electrode by three orders of magnitude, compared to that of the CdS/ITO electrode and two orders of magnitude higher than the CdS/CC electrode. A new visible-light-prompt photoelectrochemical sensor was developed based on the competitive binding reaction of Cu(2+) and CdS on the electrode surface. The results showed that the effect of the Cu(2+) on the photocurrent response was concentration-dependent over the linear ranges of 0.1-1.0 μM and 1.0-40.0 μM with a detection limit of 0.05 μM. The results of a selectivity test showed that this modified electrode has a high response toward Cu(2+) compared to other heavy metal ions. The proposed CdS/rGO/CC electrode provided a significantly high potential current compared to other reported values, and could be a practical tool for the fast, sensitive, and selective determination of Cu(2+). PMID:26595899

  2. Platinum metals magmatic sulfide ores.

    PubMed

    Naldrett, A J; Duke, J M

    1980-06-27

    Platinum-group elements (PGE) are mined predominantly from deposits that have formed by the segregation of molten iron-nickel-copper sulfides from silicate magmas. The absolute concentrations of PGE in sulfides from different deposits vary over a range of five orders of magnitude, whereas those of other chalcophile elements vary by factors of only 2 to 100. However, the relative proportions of the different PGE in a given deposit are systematically related to the nature of the parent magma. The absolute and relative concentrations of PGE in magmatic sulfides are explained in terms of the degree of partial melting of mantle peridotite required to produce the parent magma and the processes of batch equilibration and fractional segregation of sulfides. The Republic of South Africa and the U.S.S.R. together possess more than 97 percent of the world PGE reserves, but significant undeveloped resources occur in North America. The Stillwater complex in Montana is perhaps the most important example. PMID:17796685

  3. Temporal and spatial distribution of alteration, mineralization and fluid inclusions in the transitional high-sulfidation epithermal-porphyry copper system at Red Mountain, Arizona

    USGS Publications Warehouse

    Lecumberri-Sanchez, Pilar; Newton, M. Claiborne, III; Westman, Erik C.; Kamilli, Robert J.; Canby, Vertrees M.; Bodnar, Robert J.

    2013-01-01

    Red Mountain, Arizona, is a Laramide porphyry Cu system (PCD) that has experienced only a modest level of erosion compared to most other similar deposits in the southwestern United States. As a result, the upper portion of the magmatic–hydrothermal system, which represents the transition from shallower high-sulfidation epithermal mineralization to deeper porphyry Cu mineralization, is well preserved. Within the Red Mountain system, alteration, mineralization and fluid inclusion assemblages show a systematic distribution in both time and space. Early-potassic alteration (characterized by the minerals biotite and magnetite) is paragenetically earlier than late-potassic alteration (K-feldspar–anhydrite) and both are followed by later phyllic (sericite–pyrite) alteration. Advanced argillic alteration (pyrophyllite–alunite–other clay minerals) is thought to be coeval with or postdate phyllic alteration. Minerals characteristic of advanced argillic alteration are present in the near surface. Phyllic alteration extends to greater depths compared to advanced argillic alteration. Early-potassic and late-potassic alteration are only observed in the deepest part of the system. Considerable overlap of phyllic alteration with both early-potassic and late-potassic alteration zones is observed. The hypogene mineralization contains 0.4–1.2% Cu and is spatially and temporally related to the late-potassic alteration event. Molybdenum concentration is typically In the deepest part of the system, an early generation of low-to-moderate density and salinity liquid + vapor inclusions with opaque daughter minerals is followed in time by halite-bearing inclusions that also contain opaque daughter minerals indicating that an early intermediate-density magmatic fluid evolved to a high-density, high-salinity mineralizing fluid. The increase in density and salinity of fluids with time observed in the deeper parts of the system may be the result of immiscibility (“boiling”) of

  4. Trace element distribution, with a focus on gold, in copper-rich and zinc-rich sulfide chimneys from Brothers submarine volcano, Kermadec arc

    NASA Astrophysics Data System (ADS)

    Berkenbosch, H. A.; de Ronde, C. E.; McNeill, A.; Goemann, K.; Gemmell, J. B.

    2012-12-01

    Brothers volcano is a dacitic volcano located along the Kermadec arc, New Zealand, and hosts the NW Caldera hydrothermal vent field perched on part of the steep caldera walls. The field strikes for ~600 m between depths of 1550 and 1700 m and includes numerous, active, high-temperature (max 302°C) chimneys and even more dead, sulfide-rich spires. Chimney samples collected from Brothers show distinct mineralogical zonation reflecting gradients in oxidation state, temperature, and pH from the inner walls in contact with hydrothermal fluids through to the outer walls in contact with seawater. Minerals deposited from hotter fluids (e.g., chalcopyrite) are located in the interior of the chimneys and are surrounded by an external zone of minerals deposited by cooler fluids (e.g., sulfates, sphalerite). Four chimneys types are identified at Brothers volcano based on the relative proportions of chalcopyrite and sulfate layers, and the presence or absence of anhydrite. Two are Cu-rich, i.e., chalcopyrite-rich and chalcopyrite-bornite-rich chimneys, and two are Zn-rich, i.e., sphalerite-rich and sphalerite-chalcopyrite-rich. Barite and anhydrite are common to both Cu-rich chimney types whereas Zn-rich chimneys contain barite only. The main mineral phases in all the chimneys are anhydrite, barite, chalcopyrite, pyrite/marcasite, and sphalerite. Trace minerals include galena, covellite, tennantite, realgar, chalcocite, bornite, hematite, goethite, Pb-As sulfosalts, and Bi- or Au-tellurides. The vast majority of tellurides are <5 μm in size and they commonly form in bands, cluster in patches, or occur along internal grain boundaries within chalcopyrite. In sulfate layers adjacent to the chalcopyrite zones tellurides can occur as inclusions in anhydrite, barite or pyrite and/or occupy void space within the chimney. The occurrence of specular hematite and Bi- or Au-tellurides associated with chalcopyrite are consistent with magmatic contributions to the NW Caldera vent site

  5. Sulfide chemiluminescence detection

    DOEpatents

    Spurlin, Stanford R.; Yeung, Edward S.

    1985-01-01

    A method of chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction.

  6. Sulfide chemiluminescence detection

    DOEpatents

    Spurlin, S.R.; Yeung, E.S.

    1985-11-26

    A method is described for chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction. 4 figs.

  7. Cadmium sulfide membranes

    DOEpatents

    Spanhel, Lubomir; Anderson, Marc A.

    1992-07-07

    A method is described for the creation of novel q-effect cadmium sulfide membranes. The membranes are made by first creating a dilute cadmium sulfide colloid in aqueous suspension and then removing the water and excess salts therefrom. The cadmium sulfide membrane thus produced is luminescent at room temperature and may have application in laser fabrication.

  8. Cadmium sulfide membranes

    DOEpatents

    Spanhel, Lubomir; Anderson, Marc A.

    1991-10-22

    A method is described for the creation of novel q-effect cadmium sulfide membranes. The membranes are made by first creating a dilute cadmium sulfide colloid in aqueous suspension and then removing the water and excess salts therefrom. The cadmium sulfide membrane thus produced is luminescent at room temperature and may have application in laser fabrication.

  9. Occurrence model for magmatic sulfide-rich nickel-copper-(platinum-group element) deposits related to mafic and ultramafic dike-sill complexes: Chapter I in Mineral deposit models for resource assessment

    USGS Publications Warehouse

    Schulz, Klaus J.; Woodruff, Laurel G.; Nicholson, Suzanne W.; Seal, Robert R., II; Piatak, Nadine M.; Chandler, Val W.; Mars, John L.

    2014-01-01

    The sulfides in magmatic Ni-Cu deposits generally constitute a small volume of the host rock(s) and tend to be concentrated in the lower parts of the mafic and/or ultramafic bodies, often in physical depressions or areas marking changes in the geometry of the footwall topography. In most deposits, the sulfide mineralization can be divided into disseminated, matrix or net, and massive sulfide, depending on a combination of the sulfide content of the rock and the silicate texture. The major Ni-Cu sulfide mineralogy typically consists of an intergrowth of pyrrhotite (Fe7S8), pentlandite ([Fe, Ni]9S8), and chalcopyrite (FeCuS2). Cobalt, PGE, and gold (Au) are extracted from most magmatic Ni-Cu ores as byproducts, although such elements can have a significant impact on the economics in some deposits, such as the Noril’sk-Talnakh deposits, which produce much of the world’s palladium. In addition, deposits may contain between 1 and 15 percent magnetite associated with the sulfides.

  10. Integrated thin film cadmium sulfide solar cell module

    NASA Technical Reports Server (NTRS)

    Mickelsen, R. A.; Abbott, D. D.

    1971-01-01

    The design, development, fabrication and tests of flexible integrated thin-film cadmium sulfide solar cells and modules are discussed. The development of low cost and high production rate methods for interconnecting cells into large solar arrays is described. Chromium thin films were applied extensively in the deposited cell structures as a means to: (1) achieve high adherence between the cadmium sulfide films and the vacuum-metallized copper substrates, (2) obtain an ohmic contact to the cadmium sulfide films, and (3) improve the adherence of gold films as grids or contact areas.

  11. Pressure leaching las cruces copper ore

    NASA Astrophysics Data System (ADS)

    Berezowsky, R. M.; Xue, T.; Collins, M. J.; Makwana, M.; Barton-Jones, I.; Southgate, M.; Maclean, J. K.

    1999-12-01

    A hydrometallurgical process was developed for treating the Las Cruces massive sulfide-ore deposit located near Seville, Spain. A two-stage countercurrent leach process, consisting of an atmospheric leach and a pressure leach, was developed to effectively leach copper from the copper-bearing minerals and to generate a solution suitable for the subsequent solvent-extraction and copper-electrowinning operations. The results of batch and continuous miniplant tests are presented.

  12. Synthesis and photovoltaic application of coper (I) sulfide nanocrystals

    SciTech Connect

    Wu, Yue; Wadia, Cyrus; Ma, Wanli; Sadtler, Bryce; Alivisatos, A.Paul

    2008-06-24

    We present the rational synthesis of colloidal copper(I) sulfide nanocrystals and demonstrate their application as an active light absorbing component in combination with CdS nanorods to make a solution-processed solar cell with 1.6percent power conversion efficiency on both conventional glass substrates and flexible plastic substrates with stability over a 4 month testing period.

  13. Sulfide Mineralogy and Geochemistry

    NASA Astrophysics Data System (ADS)

    Dilles, John

    2007-02-01

    Reviews in Mineralogy and Geochemistry Series, Volume 61 David J. Vaughan, Editor Geochemical Society and Mineralogical Society of America; ISBN 0-939950-73-1 xiii + 714 pp.; 2006; $40. Sulfide minerals as a class represent important minor rock-forming minerals, but they are generally known as the chief sources of many economic metallic ores. In the past two decades, sulfide research has been extended to include important roles in environmental geology of sulfide weathering and resultant acid mine drainage, as well as in geomicrobiology in which bacteria make use of sulfides for metabolic energy sources. In the latter respect, sulfides played an important role in early evolution of life on Earth and in geochemical cycling of elements in the Earth's crust and hydrosphere.

  14. Platinum metals in magmatic sulfide ores

    USGS Publications Warehouse

    Naldrett, A.J.; Duke, J.M.

    1980-01-01

    Platinum-group elements (PGE) are mined predominantly from deposits that have formed by the segregation of molten iron-nickel-copper sulfides from silicate magmas. The absolute concentrations of PGE in sulfides from different deposits vary over a range of five orders of magnitude, whereas those of other chalcophile elements vary by factors of only 2 to 100. However, the relative proportions of the different PGE in a given deposit are systematically related to the nature of the parent magma. The absolute and relative concentrations of PGE in magmatic sulfides are explained in terms of the degree of partial melting of mantle peridotite required to produce the parent magma and the processes of batch equilibration and fractional segregation of sulfides. The Republic of South Africa and the U.S.S.R. together possess more than 97 percent of the world PGE reserves, but significant undeveloped resources occur in North America. The Stillwater complex in Montana is perhaps the most important example. Copyright ?? 1980 AAAS.

  15. Microbiological Leaching of Metallic Sulfides

    PubMed Central

    Razzell, W. E.; Trussell, P. C.

    1963-01-01

    The percentage of chalcopyrite leached in percolators by Thiobacillus ferrooxidans was dependent on the surface area of the ore but not on the amount. Typical examples of ore leaching, which demonstrate the role of the bacteria, are presented. In stationary fermentations, changes in KH2PO4 concentration above or below 0.1% decreased copper leaching as did reduction in the MgSO4·7H2O and increase in the (NH4)2SO4 concentration. Bacterial leaching of chalcopyrite was more effective than nonbiological leaching with ferric sulfate; ferric sulfate appeared to retard biological leaching, but this effect was likely caused by formation of an insoluble copper-iron complex. Ferrous sulfate and sodium chloride singly accentuated both bacterial and nonbiological leaching of chalcocite but jointly depressed bacterial action. Sodium chloride appeared to block bacterial iron oxidation without interfering with sulfide oxidation. Bacterial leaching of millerite, bornite, and chalcocite was greatest at pH 2.5. The economics of leaching a number of British Columbia ore bodies was discussed. PMID:16349627

  16. The Terminal Oxidase Cytochrome bd Promotes Sulfide-resistant Bacterial Respiration and Growth

    PubMed Central

    Forte, Elena; Borisov, Vitaliy B.; Falabella, Micol; Colaço, Henrique G.; Tinajero-Trejo, Mariana; Poole, Robert K.; Vicente, João B.; Sarti, Paolo; Giuffrè, Alessandro

    2016-01-01

    Hydrogen sulfide (H2S) impairs mitochondrial respiration by potently inhibiting the heme-copper cytochrome c oxidase. Since many prokaryotes, including Escherichia (E.) coli, generate H2S and encounter high H2S levels particularly in the human gut, herein we tested whether bacteria can sustain sulfide-resistant O2-dependent respiration. E. coli has three respiratory oxidases, the cyanide-sensitive heme-copper bo3 enzyme and two bd oxidases much less sensitive to cyanide. Working on the isolated enzymes, we found that, whereas the bo3 oxidase is inhibited by sulfide with half-maximal inhibitory concentration IC50 = 1.1 ± 0.1 μM, under identical experimental conditions both bd oxidases are insensitive to sulfide up to 58 μM. In E. coli respiratory mutants, both O2-consumption and aerobic growth proved to be severely impaired by sulfide when respiration was sustained by the bo3 oxidase alone, but unaffected by ≤200 μM sulfide when either bd enzyme acted as the only terminal oxidase. Accordingly, wild-type E. coli showed sulfide-insensitive respiration and growth under conditions favouring the expression of bd oxidases. In all tested conditions, cyanide mimicked the functional effect of sulfide on bacterial respiration. We conclude that bd oxidases promote sulfide-resistant O2-consumption and growth in E. coli and possibly other bacteria. The impact of this discovery is discussed. PMID:27030302

  17. Biological and Environmental Transformations of Copper-Based Nanomaterials

    PubMed Central

    Wang, Zhongying; Von Dem Bussche, Annette; Kabadi, Pranita K.; Kane, Agnes B.; Hurt, Robert H.

    2013-01-01

    Copper-based nanoparticles are an important class of materials with applications as catalysts, conductive inks, and antimicrobial agents. Environmental and safety issues are particularly important for copper-based nanomaterials because of their potential large-scale use and their high redox activity and toxicity reported from in vitro studies. Elemental nanocopper oxidizes readily upon atmospheric exposure during storage and use, so copper oxides are highly relevant phases to consider in studies of environmental and health impacts. Here we show that copper oxide nanoparticles undergo profound chemical transformations under conditions relevant to living systems and the natural environment. Copper oxide nanoparticle (CuO-NP) dissolution occurs at lysosomal pH (4-5), but not at neutral pH in pure water. Despite the near-neutral pH of cell culture medium, CuO-NPs undergo significant dissolution in media over time scales relevant to toxicity testing due to ligand-assisted ion release, in which amino acid complexation is an important contributor. Electron paramagnetic resonance (EPR) spectroscopy shows that dissolved copper in association with CuO-NPs are the primary redox-active species. CuO-NPs also undergo sulfidation by a dissolution-reprecipitation mechanism, and the new sulfide surfaces act as catalysts for sulfide oxidation. Copper sulfide NPs are found to be much less cytotoxic than CuO NPs, which is consistent with the very low solubility of CuS. Despite this low solubility of CuS, EPR studies show that sulfidated CuO continues to generate some ROS activity due to the release of free copper by H2O2 oxidation during the Fenton-chemistry-based EPR assay. While sulfidation can serve as a natural detoxification process for nanosilver and other chalcophile metals, our results suggest that sulfidation may not fully and permanently detoxify copper in biological or environmental compartments that contain reactive oxygen species. PMID:24032665

  18. Energy and materials flows in the copper industry

    SciTech Connect

    Gaines, L.L.

    1980-12-01

    The copper industry comprises both the primary copper industry, which produces 99.9%-pure copper from copper ore, and the secondary copper industry, which salvages and recycles copper-containing scrap metal to extract pure copper or copper alloys. The United States uses about 2 million tons of copper annually, 60% of it for electrical applications. Demand is expected to increase less than 4% annually for the next 20 years. The primary copper industry is concentrated in the Southwest; Arizona produced 66% of the 1979 total ore output. Primary production uses about 170 x 10/sup 12/ Btu total energy annually (about 100 x 10/sup 6/ Btu/ton pure copper produced from ore). Mining and milling use about 60% of the total consumption, because low-grade ore (0.6% copper) is now being mined. Most copper is extracted by smelting sulfide ores, with concomitant production of sulfur dioxide. Clean air regulations will require smelters to reduce sulfur emissions, necessitating smelting process modifications that could also save 20 x 10/sup 12/ Btu (10 x 10/sup 6/ Btu/ton of copper) in smelting energy. Energy use in secondary copper production averages 20 x 10/sup 6/ Btu/ton of copper. If all copper products were recycled, instead of the 30% now salvaged, the energy conservation potential would be about one-half the total energy consumption of the primary copper industry.

  19. Evidence for extreme partitioning of copper into a magmatic vapor phase

    SciTech Connect

    Lowenstern, J.B.; Mahood, G.A. ); Rivers, M.L.; Sutton, S.R. )

    1991-06-07

    The discovery of copper sulfides in carbon dioxide- and chlorine-bearing bubbles in phenocryst-hosted melt inclusions shows that copper resides in a vapor phase in some shallow magma chambers. Copper is several hundred times more concentrated in magmatic vapor than in coexisting pantellerite melt. The volatile behavior of copper should be considered when modeling the volcanogenic contribution of metals to the atmosphere and may be important in the formation of copper porphyry ore deposits.

  20. Evidence for extreme partitioning of copper into a magmatic vapor phase.

    PubMed

    Lowenstern, J B; Mahood, G A; Rivers, M L; Sutton, S R

    1991-06-01

    The discovery of copper sulfides in carbon dioxide- and chlorine-bearing bubbles in phenocryst-hosted melt inclusions shows that copper resides in a vapor phase in some shallow magma chambers. Copper is several hundred times more concentrated in magmatic vapor than in coexisting pantellerite melt. The volatile behavior of copper should be considered when modeling the volcanogenic contribution of metals to the atmosphere and may be important in the formation of copper porphyry ore deposits. PMID:17772911

  1. Sulfidation of silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Levard, C.; Michel, F. M.; Brown, G. E.

    2010-12-01

    Rapid development of nanotechnologies that exploit the properties of silver nanoparticles (Ag-NPs) raises questions concerning the impact of Ag on the environment. Ag-NPs are currently among the most widely used in the nanotechnology industry and the amount released into the environment is expected to increase along with production (1). When present in geochemical systems, Ag-NPs may undergo a variety of changes due to varying redox, pH, and chemical conditions. Expected changes range from surface modification (e.g., oxidation, sulfidation, chloridation etc.) to complete dissolution and re-precipitation. In this context, the focus of our work is on understanding the behavior of synthetic Ag-NPs with different particle sizes under varying conditions relevant to the environment. Sulfidation of Ag-NPs is of particular interest since it among the processes most likely to occur in aqueous systems, in particular under reducing conditions. Three sizes of Ag-NPs coated with polyvinyl pyrrolidone were produced using the polyol process (2) (7 ±1; 20 ±4, and 40 ±9 nm). Batch solutions containing the different Ag-NPs were subsequently reacted with Na2S solutions of different concentrations. The sulfidation process was followed step-wise for 24 hours and the corrosion products formed were characterized by electron microscopy (TEM/SEM), diffraction (XRD), and photo-electron spectroscopy (XPS). Surface charge (pHPZC) of the products formed during this process was also measured, as were changes in solubility and reactivity. Based on experimental observations we infer that the sulfidation process is the result of dissolution-precipitation and find that: (i) acanthite (Ag2S) is formed as a corrosion product; (ii) Ag-NPs aggregation increased with sulfidation rate; (iii) pHPZC increases with the rate of sulfidation; and (iv) the solubility of the corrosion products formed from sulfidation appears lower than that of non-sulfidated Ag-NPs. We observe size-dependent differences in

  2. SULFIDE METHOD PLUTONIUM SEPARATION

    DOEpatents

    Duffield, R.B.

    1958-08-12

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

  3. The bioleaching of different sulfide concentrates using thermophilic bacteria

    NASA Astrophysics Data System (ADS)

    Torres, F.; Blázquez, M. L.; González, F.; Ballester, A.; Mier, J. L.

    1995-05-01

    The bioleaching of different mineral sulfide concentrates with thermophilic bacteria (genus Sulfolobus @#@) was studied. Since the use of this type of bacteria in leaching systems involves stirring and the control of temperature, the influence of the type of stirring and the pulp density on dissolution rates was studied in order to ascertain the optimum conditions for metal recovery. At low pulp densities, the dissolution kinetic was favored by pneumatic stirring, but for higher pulp densities, orbital stirring produced the best results. A comparative study of three differential concentrates, one mixed concentrate, and one global concentrate was made. Copper and iron extraction is directly influenced by bacterial activity, while zinc dissolution is basically due to an indirect mechanism that is activated in the presence of copper ions. Galvanic interactions between the different sulfides favors the selective bioleaching of some phases (sphalerite and chalcopyrite) and leads to high metal recovery rates. However, the formation of galvanic couples depends on the type of concentrate.

  4. Zinc sulfide liquefaction catalyst

    DOEpatents

    Garg, Diwakar

    1984-01-01

    A process for the liquefaction of carbonaceous material, such as coal, is set forth wherein coal is liquefied in a catalytic solvent refining reaction wherein an activated zinc sulfide catalyst is utilized which is activated by hydrogenation in a coal derived process solvent in the absence of coal.

  5. Sulfidation kinetics of silver nanoparticles reacted with metal sulfides.

    PubMed

    Thalmann, Basilius; Voegelin, Andreas; Sinnet, Brian; Morgenroth, Eberhard; Kaegi, Ralf

    2014-05-01

    Recent studies have documented that the sulfidation of silver nanoparticles (Ag-NP), possibly released to the environment from consumer products, occurs in anoxic zones of urban wastewater systems and that sulfidized Ag-NP exhibit dramatically reduced toxic effects. However, whether Ag-NP sulfidation also occurs under oxic conditions in the absence of bisulfide has not been addressed, yet. In this study we, therefore, investigated whether metal sulfides that are more resistant toward oxidation than free sulfide, could enable the sulfidation of Ag-NP under oxic conditions. We reacted citrate-stabilized Ag-NP of different sizes (10-100 nm) with freshly precipitated and crystalline CuS and ZnS in oxygenated aqueous suspensions at pH 7.5. The extent of Ag-NP sulfidation was derived from the increase in dissolved Cu(2+) or Zn(2+) over time and linked with results from X-ray absorption spectroscopy (XAS) analysis of selected samples. The sulfidation of Ag-NP followed pseudo first-order kinetics, with rate coefficients increasing with decreasing Ag-NP diameter and increasing metal sulfide concentration and depending on the type (CuS and ZnS) and crystallinity of the reacting metal sulfide. Results from analytical electron microscopy revealed the formation of complex sulfidation patterns that seemed to follow preexisting subgrain boundaries in the pristine Ag-NP. The kinetics of Ag-NP sulfidation observed in this study in combination with reported ZnS and CuS concentrations and predicted Ag-NP concentrations in wastewater and urban surface waters indicate that even under oxic conditions and in the absence of free sulfide, Ag-NP can be transformed into Ag2S within a few hours to days by reaction with metal sulfides. PMID:24678586

  6. Copper transport.

    PubMed

    Linder, M C; Wooten, L; Cerveza, P; Cotton, S; Shulze, R; Lomeli, N

    1998-05-01

    In adult humans, the net absorption of dietary copper is approximately 1 mg/d. Dietary copper joins some 4-5 mg of endogenous copper flowing into the gastrointestinal tract through various digestive juices. Most of this copper returns to the circulation and to the tissues (including liver) that formed them. Much lower amounts of copper flow into and out of other major parts of the body (including heart, skeletal muscle, and brain). Newly absorbed copper is transported to body tissues in two phases, borne primarily by plasma protein carriers (albumin, transcuprein, and ceruloplasmin). In the first phase, copper goes from the intestine to the liver and kidney; in the second phase, copper usually goes from the liver (and perhaps also the kidney) to other organs. Ceruloplasmin plays a role in this second phase. Alternatively, liver copper can also exit via the bile, and in a form that is less easily reabsorbed. Copper is also present in and transported by other body fluids, including those bathing the brain and central nervous system and surrounding the fetus in the amniotic sac. Ceruloplasmin is present in these fluids and may also be involved in copper transport there. The concentrations of copper and ceruloplasmin in milk vary with lactational stage. Parallel changes occur in ceruloplasmin messenger RNA expression in the mammary gland (as determined in pigs). Copper in milk ceruloplasmin appears to be particularly available for absorption, at least in rats. PMID:9587137

  7. Sulfide detoxification in plant mitochondria.

    PubMed

    Birke, Hannah; Hildebrandt, Tatjana M; Wirtz, Markus; Hell, Rüdiger

    2015-01-01

    In contrast to animals, which release the signal molecule sulfide in small amounts from cysteine and its derivates, phototrophic eukaryotes generate sulfide as an essential intermediate of the sulfur assimilation pathway. Additionally, iron-sulfur cluster turnover and cyanide detoxification might contribute to the release of sulfide in mitochondria. However, sulfide is a potent inhibitor of cytochrome c oxidase in mitochondria. Thus, efficient sulfide detoxification mechanisms are required in mitochondria to ensure adequate energy production and consequently survival of the plant cell. Two enzymes have been recently described to catalyze sulfide detoxification in mitochondria of Arabidopsis thaliana, O-acetylserine(thiol)lyase C (OAS-TL C), and the sulfur dioxygenase (SDO) ethylmalonic encephalopathy protein 1 (ETHE1). Biochemical characterization of sulfide producing and consuming enzymes in mitochondria of plants is fundamental to understand the regulatory network that enables mitochondrial sulfide homeostasis under nonstressed and stressed conditions. In this chapter, we provide established protocols to determine the activity of the sulfide releasing enzyme β-cyanoalanine synthase as well as sulfide-consuming enzymes OAS-TL and SDO. Additionally, we describe a reliable and efficient method to purify OAS-TL proteins from plant material. PMID:25747485

  8. Geothermal hydrogen sulfide removal

    SciTech Connect

    Urban, P.

    1981-04-01

    UOP Sulfox technology successfully removed 500 ppM hydrogen sulfide from simulated mixed phase geothermal waters. The Sulfox process involves air oxidation of hydrogen sulfide using a fixed catalyst bed. The catalyst activity remained stable throughout the life of the program. The product stream composition was selected by controlling pH; low pH favored elemental sulfur, while high pH favored water soluble sulfate and thiosulfate. Operation with liquid water present assured full catalytic activity. Dissolved salts reduced catalyst activity somewhat. Application of Sulfox technology to geothermal waters resulted in a straightforward process. There were no requirements for auxiliary processes such as a chemical plant. Application of the process to various types of geothermal waters is discussed and plans for a field test pilot plant and a schedule for commercialization are outlined.

  9. Biotreatment of refinery spent sulfidic caustics

    SciTech Connect

    Sublette, K.L.; Rajganesh, B.; Woolsey, M.; Plato, A.

    1995-12-31

    Caustics are used in petroleum refinering to remove hydrogen sulfide from various hydrocarbon streams. Spent sulfidic caustics from two Conoco refineries have been successfully biotreated on bench and pilot scale, resulting in neutralization and removal of active sulfides. Sulfides were completely oxidized to sulfate by Thiobacillus denitrificans. Microbial oxidation of sulfide produced acid, which at least partially neutralized the caustic.

  10. Alloyed Copper Chalcogenide Nanoplatelets via Partial Cation Exchange Reactions

    PubMed Central

    2014-01-01

    We report the synthesis of alloyed quaternary and quinary nanocrystals based on copper chalcogenides, namely, copper zinc selenide–sulfide (CZSeS), copper tin selenide–sulfide (CTSeS), and copper zinc tin selenide–sulfide (CZTSeS) nanoplatelets (NPLs) (∼20 nm wide) with tunable chemical composition. Our synthesis scheme consisted of two facile steps: i.e., the preparation of copper selenide–sulfide (Cu2–xSeyS1–y) platelet shaped nanocrystals via the colloidal route, followed by an in situ cation exchange reaction. During the latter step, the cation exchange proceeded through a partial replacement of copper ions by zinc or/and tin cations, yielding homogeneously alloyed nanocrystals with platelet shape. Overall, the chemical composition of the alloyed nanocrystals can easily be controlled by the amount of precursors that contain cations of interest (e.g., Zn, Sn) to be incorporated/alloyed. We have also optimized the reaction conditions that allow a complete preservation of the size, morphology, and crystal structure as that of the starting Cu2–xSeyS1–y NPLs. The alloyed NPLs were characterized by optical spectroscopy (UV–vis–NIR) and cyclic voltammetry (CV), which demonstrated tunability of their light absorption characteristics as well as their electrochemical band gaps. PMID:25050455

  11. The cytochrome bd oxidase of Escherichia coli prevents respiratory inhibition by endogenous and exogenous hydrogen sulfide.

    PubMed

    Korshunov, Sergey; Imlay, Karin R C; Imlay, James A

    2016-07-01

    When sulfur compounds are scarce or difficult to process, Escherichia coli adapts by inducing the high-level expression of sulfur-compound importers. If cystine then becomes available, the cystine is rapidly overimported and reduced, leading to a burgeoning pool of intracellular cysteine. Most of the excess cysteine is exported, but some is adventitiously degraded, with the consequent release of sulfide. Sulfide is a potent ligand of copper and heme moieties, raising the prospect that it interferes with enzymes. We observed that when cystine was provided and sulfide levels rose, E. coli became strictly dependent upon cytochrome bd oxidase for continued respiration. Inspection revealed that low-micromolar levels of sulfide inhibited the proton-pumping cytochrome bo oxidase that is regarded as the primary respiratory oxidase. In the absence of the back-up cytochrome bd oxidase, growth failed. Exogenous sulfide elicited the same effect. The potency of sulfide was enhanced when oxygen concentrations were low. Natural oxic-anoxic interfaces are often sulfidic, including the intestinal environment where E. coli dwells. We propose that the sulfide resistance of the cytochrome bd oxidase is a key trait that permits respiration in such habitats. PMID:26991114

  12. Surface reactivity of pyrite and related sulfides

    NASA Astrophysics Data System (ADS)

    Murphy, Riley; Strongin, Daniel R.

    2009-01-01

    Pyrite, FeS 2, commonly referred to as "Fool's gold" is the most common sulfide in the Earth's surface region. Not only is the mineral ubiquitous, but the reactivity of pyrite is of central importance in a devastating environmental issue known as acid mine drainage (AMD) and in beneficial commercial processes such as mineral benefaction, which can range from the desulfurization of coal to the isolation of copper or gold ores. Pyrite has even been postulated to be a key constituent of a prebiotic iron-sulfur world existing at the high pressure and temperature conditions common to hydrothermal vents at the oceanic floor. The development of an atomic level picture of the structure and reactivity of pyrite is paramount to understanding the chemistry of this mineral in these wide-ranging environments. This contribution focuses on research carried out over the past three decades that has used modern surface science tools to understand the reactivity of pyrite surfaces. An understanding of the reactivity of the pyrite surfaces has benefited from studies using a wide range of experimental techniques that range from vacuum-based experiments utilizing electron and photon spectroscopies, and probe microscopy to in situ studies using infra-red spectroscopy. Synchrotron-based techniques that include photoelectron spectroscopy and X-ray absorption spectroscopy have played a large role in both these environments. These techniques have perhaps been the most useful in establishing the structure of the pristine pyrite surface. Related iron sulfides are also briefly introduced in this review including pyrrhotite (Fe xS 1- x) and the dimorph of pyrite, marcasite. The surface reactivity of these sulfides exhibit both similarities and differences to pyrite, and help to bring forward the unique activity of pyrite in both environmentally and technologically important conditions.

  13. Hydrogen sulfide intoxication.

    PubMed

    Guidotti, Tee L

    2015-01-01

    Hydrogen sulfide (H2S) is a hazard primarily in the oil and gas industry, agriculture, sewage and animal waste handling, construction (asphalt operations and disturbing marshy terrain), and other settings where organic material decomposes under reducing conditions, and in geothermal operations. It is an insoluble gas, heavier than air, with a very low odor threshold and high toxicity, driven by concentration more than duration of exposure. Toxicity presents in a unique, reliable, and characteristic toxidrome consisting, in ascending order of exposure, of mucosal irritation, especially of the eye ("gas eye"), olfactory paralysis (not to be confused with olfactory fatigue), sudden but reversible loss of consciousness ("knockdown"), pulmonary edema (with an unusually favorable prognosis), and death (probably with apnea contributing). The risk of chronic neurcognitive changes is controversial, with the best evidence at high exposure levels and after knockdowns, which are frequently accompanied by head injury or oxygen deprivation. Treatment cannot be initiated promptly in the prehospital phase, and currently rests primarily on supportive care, hyperbaric oxygen, and nitrite administration. The mechanism of action for sublethal neurotoxicity and knockdown is clearly not inhibition of cytochrome oxidase c, as generally assumed, although this may play a role in overwhelming exposures. High levels of endogenous sulfide are found in the brain, presumably relating to the function of hydrogen sulfide as a gaseous neurotransmitter and immunomodulator. Prevention requires control of exposure and rigorous training to stop doomed rescue attempts attempted without self-contained breathing apparatus, especially in confined spaces, and in sudden release in the oil and gas sector, which result in multiple avoidable deaths. PMID:26563786

  14. Application of Borehole SIP Technique to Sulfide Mineral Exploration

    NASA Astrophysics Data System (ADS)

    Kim, Changryol; Park, Mi Kyung; Park, Samgyu; Sung, Nak Hoon; Shin, Seung Wook

    2016-04-01

    In the study, SIP (Spectral Induced Polarization) well logging probe system was developed to rapidly locate the metal ore bodies with sulfide minerals in the boreholes. The newly developed SIP logging probe employed the non-polarizable electrodes, consisting of zinc chloride (ZnCl2), sodium chloride (NaCl), gypsum (CaSO4·2H2O), and water (H2O), instead of existing copper electrodes, leading to eliminating the EM coupling effect in the IP surveys as much as possible. In addition, the SIP logging system is designed to make measurements down to maximum 500 meters in depth in the boreholes. The SIP well logging was conducted to examine the applicability of the SIP probe system to the boreholes at the ore mine in Jecheon area, Korea. The boreholes used in the SIP logging are known to have penetrated the metal ore bodies with sulfide minerals from the drilling investigations. The ore mine of the study area is the scarn deposits surrounded by the limestone or lime-silicate rocks in Ordovician period. The results of the SIP well logging have shown that the borehole segments with limestone or lime-silicate rocks yielded the insignificant SIP responses while the borehole segments with sulfide minerals (e.g. pyrite) provided the significant phase shifts of the SIP responses. The borehole segments penetrating the metal ore body, so-called cupola, have shown very high response of the phase shift, due to the high contents of the sulfide mineral pyrite. The phase shifts of the SIP response could be used to estimate the grade of the ore bodies since the higher contents of the sulfide minerals, the higher magnitudes of the phase shifts in the SIP responses. It is, therefore, believed that the borehole SIP technique can be applied to investigate the metal ore bodies with sulfide minerals, and that could be used to estimate the ore grades as a supplementary tool in the future.

  15. Selenium content in sulfide ores from the Chalkidiki peninsula, Greece.

    PubMed

    Nicolaidou, A E

    1998-01-01

    Selenium (Se) was assessed in galena, sphalerite, and pyrite samples. These are components of mixed sulfide ores from the Olympias and Madem Lakkos-Mavres Petres deposits and the Skouries porphyry-copper deposit. We used atomic absorption spectroscopy (AAS) with a hydride generator system. The highest concentration of Se (516 ppm) was found in the fine-grained galena at the -135 level of the Olympias deposits. In the Madem Lakkos-Mavres Petres deposit, the highest concentration of Se (33 ppm) was found in the pyrites of the level 30. The concentration of Se in the arsenopyrites and chalcopyrites is lower than the detection limit of the analytical method (< 100 ppb). The concentrated chalcopyrite from the porphyry copper deposit at Skouries exhibits a significant Se content (average 200 ppm) in contrast to the chalcopyrite from the Olympias and the Madem Lakkos-Mavres Petres. Variations in the Se content of the sulfide minerals studied could be caused by redox-pH and/or temperature conditions, as well as by the difference in crystal structure. The Se found in the areas studied may positively affect the environment. Sulfide minerals are oxidized by microorganisms, infiltrate in the soil-water in the form of selenate or selenite ion, and directly or indirectly influence the human organism. PMID:9726790

  16. Selective Facet Reactivity During Cation Exchange in Cadmium Sulfide Nanorods

    SciTech Connect

    Sadtler, Bryce; Demchenko, Denis; Zheng, Haimei; Hughes, Steven; Merkle, Maxwell; Dahmen, Ulrich; Wang, Lin-Wang; Alivisatos, A. Paul

    2008-12-18

    The partial transformation of ionic nanocrystals through cation exchange has been used to synthesize nanocrystal heterostructures. We demonstrate that the selectivity for cation exchange to take place at different facets of the nanocrystal plays an important role in determining the resulting morphology of the binary heterostructure. In the case of copper I (Cu+) cation exchange in cadmium sulfide (CdS) nanorods, the reaction starts preferentially at the ends of the nanorods such that copper sulfide (Cu2S) grows inwards from either end. The resulting morphology is very different from the striped pattern obtained in our previous studies of silver I (Ag+) exchange in CdS nanorods where non-selective nucleation of silver sulfide (Ag2S) occurs. From interface formation energies calculated for several models of epitaxialconnections between CdS and Cu2S or Ag2S, we infer the relative stability of each interface during the nucleation and growth of Cu2S or Ag2S within the CdS nanorods. The epitaxial connections of Cu2S to the end facets of CdS nanorods minimize the formation energy, making these interfaces stable throughout the exchange reaction. However, as the two end facets of wurtzite CdS nanorods are crystallographically nonequivalent, asymmetric heterostructures can be produced.

  17. Field method for sulfide determination

    SciTech Connect

    Wilson, B L; Schwarser, R R; Chukwuenye, C O

    1982-01-01

    A simple and rapid method was developed for determining the total sulfide concentration in water in the field. Direct measurements were made using a silver/sulfide ion selective electrode in conjunction with a double junction reference electrode connected to an Orion Model 407A/F Specific Ion Meter. The method also made use of a sulfide anti-oxidant buffer (SAOB II) which consists of ascorbic acid, sodium hydroxide, and disodium EDTA. Preweighed sodium sulfide crystals were sealed in air tight plastic volumetric flasks which were used in standardization process in the field. Field standards were prepared by adding SAOB II to the flask containing the sulfide crystals and diluting it to the mark with deionized deaerated water. Serial dilutions of the standards were used to prepare standards of lower concentrations. Concentrations as low as 6 ppB were obtained on lake samples with a reproducibility better than +- 10%.

  18. Sulfide Mineral Surfaces

    SciTech Connect

    Rosso, Kevin M.; Vaughan, David J.

    2006-08-01

    The past twenty years or so have seen dramatic development of the experimental and theoretical tools available to study the surfaces of solids at the molecular (?atomic resolution?) scale. On the experimental side, two areas of development well illustrate these advances. The first concerns the high intensity photon sources associated with synchrotron radiation; these have both greatly improved the surface sensitivity and spatial resolution of already established surface spectroscopic and diffraction methods, and enabled the development of new methods for studying surfaces. The second centers on the scanning probe microscopy (SPM) techniques initially developed in the 1980's with the first scanning tunneling microscope (STM) and atomic force microscope (AFM) experiments. The direct 'observation' of individual atoms at surfaces made possible with these methods has truly revolutionized surface science. On the theoretical side, the availability of high performance computers coupled with advances in computational modeling has provided powerful new tools to complement the advances in experiment. Particularly important have been the quantum mechanics based computational approaches such as density functional theory (DFT), which can now be easily used to calculate the equilibrium crystal structures of solids and surfaces from first principles, and to provide insights into their electronic structure. In this chapter, we review current knowledge of sulfide mineral surfaces, beginning with an overview of the principles relevant to the study of the surfaces of all crystalline solids. This includes the thermodynamics of surfaces, the atomic structure of surfaces (surface crystallography and structural stability, adjustments of atoms at the surface through relaxation or reconstruction, surface defects) and the electronic structure of surfaces. We then discuss examples where specific crystal surfaces have been studied, with the main sulfide minerals organized by structure type

  19. Dispersion strengthened copper

    DOEpatents

    Sheinberg, Haskell; Meek, Thomas T.; Blake, Rodger D.

    1990-01-01

    A composition of matter comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide, and a method for making this composition of matter.

  20. Dispersion strengthened copper

    DOEpatents

    Sheinberg, Haskell; Meek, Thomas T.; Blake, Rodger D.

    1989-01-01

    A composition of matter comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide, and a method for making this composition of matter.

  1. Electrobioleaching of base metal sulfides

    NASA Astrophysics Data System (ADS)

    Natarajan, K. A.

    1992-01-01

    Bioleaching of base metal sulfides, such as pyrite, chalcopyrite, and sphalerite, under the influence of applied direct current (DC) potentials is discussed. Contributions toward mineral dissolution from three effects, namely, galvanic, applied potential, and microbiological, are analyzed and compared. Sphalerite could be selectively bioleached in the presence of Thiobacillus ferrooxidans under an applied potential of -500 mV (SCE) from mixed sulfides containing sphalerite, pyrite, and chalcopyrite. Bacterial activity and growth were found to be promoted under electrobioleaching conditions. Probable mechanisms involved in the bioleaching of different sulfides under positive and negative applied potentials are discussed.

  2. Copper Metallochaperones

    PubMed Central

    Robinson, Nigel J.; Winge, Dennis R.

    2014-01-01

    The current state of knowledge on how copper metallochaperones support the maturation of cuproproteins is reviewed. Copper is needed within mitochondria to supply the CuA and intramembrane CuB sites of cytochrome oxidase, within the trans-Golgi network to supply secreted cuproproteins and within the cytosol to supply superoxide dismutase 1 (Sod1). Subpopulations of copper-zinc superoxide dismutase also localize to mitochondria, the secretory system, the nucleus and, in plants, the chloroplast, which also requires copper for plastocyanin. Prokaryotic cuproproteins are found in the cell membrane and in the periplasm of gram-negative bacteria. Cu(I) and Cu(II) form tight complexes with organic molecules and drive redox chemistry, which unrestrained would be destructive. Copper metallochaperones assist copper in reaching vital destinations without inflicting damage or becoming trapped in adventitious binding sites. Copper ions are specifically released from copper metallochaperones upon contact with their cognate cuproproteins and metal transfer is thought to proceed by ligand substitution. PMID:20205585

  3. A novel method for improving cerussite sulfidization

    NASA Astrophysics Data System (ADS)

    Feng, Qi-cheng; Wen, Shu-ming; Zhao, Wen-juan; Cao, Qin-bo; Lü, Chao

    2016-06-01

    Evaluation of flotation behavior, solution measurements, and surface analyses were performed to investigate the effects of chloride ion addition on the sulfidization of cerussite in this study. Micro-flotation tests indicate that the addition of chloride ions prior to sulfidization can significantly increase the flotation recovery of cerussite, which is attributed to the formation of more lead sulfide species on the mineral surface. Solution measurement results suggest that the addition of chloride ions prior to sulfidization induces the transformation of more sulfide ions from pulp solution onto the mineral surface by the formation of more lead sulfide species. X-ray diffraction and energy-dispersive spectroscopy indicate that more lead sulfide species form on the mineral surface when chloride ions are added prior to sulfidization. These results demonstrate that the addition of chloride ions prior to sulfidization can significantly improve the sulfidization of cerussite, thereby enhancing the flotation performance.

  4. Prevention of sulfide oxidation in sulfide-rich waste rock

    NASA Astrophysics Data System (ADS)

    Nyström, Elsa; Alakangas, Lena

    2015-04-01

    The ability to reduce sulfide oxidation in waste rock after mine closure is a widely researched area, but to reduce and/or inhibit the oxidation during operation is less common. Sulfide-rich (ca 30 % sulfur) waste rock, partially oxidized, was leached during unsaturated laboratory condition. Trace elements such as As and Sb were relatively high in the waste rock while other sulfide-associated elements such as Cu, Pb and Zn were low compared to common sulfide-rich waste rock. Leaching of unsaturated waste rock lowered the pH, from around six down to two, resulting in continuously increasing element concentrations during the leaching period of 272 days. The concentrations of As (65 mg/L), Cu (6.9 mg/L), Sb (1.2 mg/L), Zn (149 mg/L) and S (43 g/L) were strongly elevated at the end of the leaching period. Different alkaline industrial residues such as slag, lime kiln dust and cement kiln dust were added as solid or as liquid to the waste rock in an attempt to inhibit sulfide oxidation through neo-formed phases on sulfide surfaces in order to decrease the mobility of metals and metalloids over longer time scale. This will result in a lower cost and efforts of measures after mine closure. Results from the experiments will be presented.

  5. Apparatus for use in sulfide chemiluminescence detection

    DOEpatents

    Spurlin, S.R.; Yeung, E.S.

    1987-01-06

    A method is described for chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction. 4 figs.

  6. Apparatus for use in sulfide chemiluminescence detection

    DOEpatents

    Spurlin, Stanford R.; Yeung, Edward S.

    1987-01-01

    A method of chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction.

  7. Thermoelectric Properties of Lanthanum Sulfide

    NASA Technical Reports Server (NTRS)

    Wood, C.; Lockwood, R.; Parker, J. B.; Zoltan, A.; Zoltan, L. D.; Danielson, L.; Raag, V.

    1987-01-01

    Report describes measurement of Seebeck coefficient, electrical resistivity, thermal conductivity, and Hall effect in gamma-phase lanthanum sulfide with composition of La3-x S4. Results of study, part of search for high-temperature thermoelectric energy-conversion materials, indicate this sulfide behaves like extrinsic semiconductor over temperature range of 300 to 1,400 K, with degenerate carrier concentration controlled by stoichiometric ratio of La to S.

  8. Hydrogen Sulfide Oxidation by Myoglobin.

    PubMed

    Bostelaar, Trever; Vitvitsky, Victor; Kumutima, Jacques; Lewis, Brianne E; Yadav, Pramod K; Brunold, Thomas C; Filipovic, Milos; Lehnert, Nicolai; Stemmler, Timothy L; Banerjee, Ruma

    2016-07-13

    Enzymes in the sulfur network generate the signaling molecule, hydrogen sulfide (H2S), from the amino acids cysteine and homocysteine. Since it is toxic at elevated concentrations, cells are equipped to clear H2S. A canonical sulfide oxidation pathway operates in mitochondria, converting H2S to thiosulfate and sulfate. We have recently discovered the ability of ferric hemoglobin to oxidize sulfide to thiosulfate and iron-bound hydropolysulfides. In this study, we report that myoglobin exhibits a similar capacity for sulfide oxidation. We have trapped and characterized iron-bound sulfur intermediates using cryo-mass spectrometry and X-ray absorption spectroscopy. Further support for the postulated intermediates in the chemically challenging conversion of H2S to thiosulfate and iron-bound catenated sulfur products is provided by EPR and resonance Raman spectroscopy in addition to density functional theory computational results. We speculate that the unusual sensitivity of skeletal muscle cytochrome c oxidase to sulfide poisoning in ethylmalonic encephalopathy, resulting from the deficiency in a mitochondrial sulfide oxidation enzyme, might be due to the concentration of H2S by myoglobin in this tissue. PMID:27310035

  9. New influence factor inducing difficulty in selective flotation separation of Cu-Zn mixed sulfide minerals

    NASA Astrophysics Data System (ADS)

    Deng, Jiu-shuai; Mao, Ying-bo; Wen, Shu-ming; Liu, Jian; Xian, Yong-jun; Feng, Qi-cheng

    2015-02-01

    Selective flotation separation of Cu-Zn mixed sulfides has been proven to be difficult. Thus far, researchers have found no satisfactory way to separate Cu-Zn mixed sulfides by selective flotation, mainly because of the complex surface and interface interaction mechanisms in the flotation solution. Undesired activation occurs between copper ions and the sphalerite surfaces. In addition to recycled water and mineral dissolution, ancient fluids in the minerals are observed to be a new source of metal ions. In this study, significant amounts of ancient fluids were found to exist in Cu-Zn sulfide and gangue minerals, mostly as gas-liquid fluid inclusions. The concentration of copper ions released from the ancient fluids reached 1.02 × 10-6 mol/L, whereas, in the cases of sphalerite and quartz, this concentration was 0.62 × 10-6 mol/L and 0.44 × 10-6 mol/L, respectively. As a result, the ancient fluid is a significant source of copper ions compared to mineral dissolution under the same experimental conditions, which promotes the unwanted activation of sphalerite. Therefore, the ancient fluid is considered to be a new factor that affects the selective flotation separation of Cu-Zn mixed sulfide ores.

  10. Amorphous molybdenum sulfides as hydrogen evolution catalysts.

    PubMed

    Morales-Guio, Carlos G; Hu, Xile

    2014-08-19

    from simple wet-chemical routes. Electron transport is sometimes slow in the particle catalysts, and an impedance model has been established to identify this slow electron transport. Finally, the amorphous molybdenum sulfide film catalyst has been integrated onto a copper(I) oxide photocathode for photoelectrochemical hydrogen evolution. The conformal catalyst efficiently extracts the excited electrons to give an impressive photocurrent density of -5.7 mA/cm(2) at 0 V vs RHE. The catalyst also confers good stability. PMID:25065612

  11. Ionization levels of doped copper indium sulfide chalcopyrites.

    PubMed

    Tablero, C

    2012-02-01

    The electronic structure of modified chalcopyrite CuInS(2) has been analyzed from first principles within the density functional theory. The host chalcopyrite has been modified by introducing atomic impurities M at substitutional sites in the lattice host with M = C, Si, Ge, Sn, Ti, V, Cr, Fe, Co, Ni, Rh, and Ir. Both substitutions M for In and M for Cu have been analyzed. The gap and ionization energies are obtained as a function of the M-S displacements. It is interesting for both spintronic and optoelectronic applications because it can provide significant information with respect to the pressure effect and the nonradiative recombination. PMID:22239718

  12. Inhaled Hydrogen Sulfide

    PubMed Central

    Volpato, Gian Paolo; Searles, Robert; Yu, Binglan; Scherrer-Crosbie, Marielle; Bloch, Kenneth D.; Ichinose, Fumito; Zapol, Warren M.

    2010-01-01

    Background Breathing hydrogen sulfide (H2S) has been reported to induce a suspended animation–like state with hypothermia and a concomitant metabolic reduction in rodents. However, the impact of H2S breathing on cardiovascular function remains incompletely understood. In this study, the authors investigated the cardiovascular and metabolic effects of inhaled H2S in a murine model. Methods The impact of breathing H2S on cardiovascular function was examined using telemetry and echocardiography in awake mice. The effects of breathing H2S on carbon dioxide production and oxygen consumption were measured at room temperature and in a warmed environment. Results Breathing H2S at 80 parts per million by volume at 27°C ambient temperature for 6 h markedly reduced heart rate, core body temperature, respiratory rate, and physical activity, whereas blood pressure remained unchanged. Echocardiography demonstrated that H2S exposure decreased both heart rate and cardiac output but preserved stroke volume. Breathing H2S for 6 h at 35°C ambient temperature (to prevent hypothermia) decreased heart rate, physical activity, respiratory rate, and cardiac output without altering stroke volume or body temperature. H2S breathing seems to induce bradycardia by depressing sinus node activity. Breathing H2S for 30 min decreased whole body oxygen consumption and carbon dioxide production at either 27° or 35°C ambient temperature. Both parameters returned to baseline levels within 10 min after the cessation of H2S breathing. Conclusions Inhalation of H2S at either 27° or 35°C reversibly depresses cardiovascular function without changing blood pressure in mice. Breathing H2S also induces a rapidly reversible reduction of metabolic rate at either body temperature. PMID:18362598

  13. Sulfur and sulfides in chondrules

    NASA Astrophysics Data System (ADS)

    Marrocchi, Yves; Libourel, Guy

    2013-10-01

    The nature and distribution of sulfides within type I PO, POP and PP chondrules of the carbonaceous chondrite Vigarano (CV3) have been studied by secondary electron microscopy and electron microprobe. They occur predominantly as spheroidal blebs composed entirely of low-Ni iron sulfide (troilite, FeS) or troilite + magnetite but in less abundance in association with metallic Fe-Ni beads in opaque assemblages. Troilites are mainly located within the low-Ca pyroxene outer zone and their amounts increase with the abundance of low-Ca pyroxene within chondrules, suggesting co-crystallization of troilite and low-Ca pyroxene during high-temperature events. We show that sulfur concentration and sulfide occurrence in chondrules obey high temperature sulfur solubility and saturation laws. Depending on the fS2 and fO2 of the surrounding gas and on the melt composition, mainly the FeO content, sulfur dissolved in chondrule melts may eventually reach a concentration limit, the sulfur content at sulfide saturation (SCSS), at which an immiscible iron sulfide liquid separates from the silicate melt. The occurrence of both a silicate melt and an immiscible iron sulfide liquid is further supported by the non-wetting behavior of sulfides on silicate phases in chondrules due to the high interfacial tension between their precursor iron-sulfide liquid droplets and the surrounding silicate melt during the high temperature chondrule-forming event. The evolution of chondrule melts from PO to PP towards more silicic compositions, very likely due to high PSiO(g) of the surrounding nebular gas, induces saturation of FeS at much lower S content in PP than in PO chondrules, leading to the co-crystallization of iron sulfides and low-Ca pyroxenes. Conditions of co-saturation of low-Ca pyroxene and FeS are only achieved in non canonical environments characterized by high partial pressures of sulfur and SiO and redox conditions more oxidizing than IW-3. Fe and S mass balance calculations also

  14. Mechanistic chemical perspective of hydrogen sulfide signaling.

    PubMed

    Nagy, Péter

    2015-01-01

    Hydrogen sulfide is now a well-appreciated master regulator in a diverse array of physiological processes. However, as a consequence of the rapid growth of the area, sulfide biology suffers from an increasing number of controversial observations and interpretations. A better understanding of the underlying molecular pathways of sulfide's actions is key to reconcile controversial issues, which calls for rigorous chemical/biochemical investigations. Protein sulfhydration and coordination/redox chemical interactions of sulfide with heme proteins are the two most extensively studied pathways in sulfide biochemistry. These pathways are important mediators of protein functions, generate bioactive sulfide metabolites, contribute to sulfide storage/trafficking and carry antioxidant functions. In addition, inorganic polysulfides, which are oxidative sulfide metabolites, are increasingly recognized as important players in sulfide biology. This chapter provides an overview of our mechanistic perspective on the reactions that govern (i) sulfide's bioavailability (including the delicate enzyme machineries that orchestrate sulfide production and consumption and the roles of the large sulfide-storing pools as biological buffers), (ii) biological significance and mechanisms of persulfide formation (including the reduction of disulfides, condensation with sulfenic acids, oxidation of thiols with polysulfides and radical-mediated pathways), (iii) coordination and redox chemical interactions of sulfide with heme proteins (including cytochrome c oxidase, hemoglobins, myoglobins and peroxidases), and (iv) the chemistry of polysulfides. PMID:25725513

  15. Photoactive nanocrystals by low-temperature welding of copper sulfide nanoparticles and indium sulfide nanosheets.

    PubMed

    Lim, Hui Min; Tan, Jia Yi; Batabyal, Sudip K; Magdassi, Shlomo; Mhaisalkar, Subodh G; Wong, Lydia H

    2014-12-01

    We successfully utilize the concept of coalescence and room-temperature sintering to prepare morphologically different nanoparticles. n-Type chalcogenide (CuIn5 S8 ) nanocrystals are synthesized at room temperature by simple mixing of oppositely charged precursor nanoparticles. The coalescence of polycation-coated CuS nanoparticles and negatively charged In2 S3 nanoplates is driven by close contact of the particles due to electrostatic interactions. Analysis by X-ray diffraction, transmission electron microscopy (TEM) imaging, and Raman spectroscopy confirms the formation of single-phase CuIn5 S8 without traceable secondary phase. In a photovoltaic device, the use of the coalesced particles yields a power conversion efficiency of 1.8%. PMID:25146714

  16. Cadmium sulfide/copper sulfide heterojunction cell research. Technical progress report, September 1-November 30, 1979

    SciTech Connect

    Anderson, W.W.; Jonath, A.D.

    1980-02-01

    Several all sputter deposited Cu/sub 2/S/CdS cells have been prepared to date with J/sub SC/ approx. = 3 mA/cm/sup 2/ under simulated AM1 illumination. The best AM1 conversion efficiency obtained is 0.6%. This is shown to be typical of sputtered CdS in Cu/sub 2/S/CdS cells investigated to date. The sputtered Cu/sub 2/S appears to be satisfactory for solar cell applications. Presented evidence indicates that the poor conversion efficiency is due to a low-junction electric field intensity on the CdS side of the heterojunction. A multilayer CdS structure has been developed which may allow the tailoring of the junction electric field intensity to a selected high value to obtain high-junction collection efficiency. Other areas of cell development advances included: (1) determination of effect of Cu cones in Cu/sub 2/S on Cu/sub 2/S/CdS cell performance; (2) solution of CdS pinhole problem; and (3) open circuit voltage improvement by heat treatment.

  17. Cadmium sulfide-copper sulfide heterojunction cell research. Quarterly report, September 1-November 30, 1980

    SciTech Connect

    1981-02-01

    Cell yield data for both Cu/sub 2/S/CdS and Cu/sub 2/S/(CdZn)S are reported. The presence of cracking in the n-type films is reported and the influence of composition and substrate material described. Design efforts for an analytical device that is basically a CdS cell on a transparent substrate, and a low cost gridding procedure are reported. A laser scanning system has been developed to detect incipient shorts and shunting in ungridded cells.

  18. Sulfide Capacity in Ladle Slag at Steelmaking Temperatures

    NASA Astrophysics Data System (ADS)

    Allertz, Carl; Sichen, Du

    2015-12-01

    Sulfide capacity measurements were conducted at 1823 K and 1873 K (1550 °C and 1600 °C) for the quaternary Al2O3-CaO-MgO-SiO2 system, for typical compositions used in the ladle in steelmaking. A copper-slag equilibrium was used under controlled oxygen and sulfur potentials. The sulfide capacity is strongly dependent on the composition and it was found to increase with the basic oxides, while it decreases with increase of the acidic components. It was found that CaO is more effective in holding sulfur in the slag compared to MgO when replacing SiO2. For the present slag compositions, Al2O3 and SiO2 behaved similar with respect to sulfur, and no considerable effect could be recorded when replacing one for the other. The sulfide capacity was also found to be strongly dependent on the temperature, increasing with temperature. The present results were compared with industrial data from the ladle, after vacuum treatment, and they were in good agreement.

  19. Sulfide Stability of Planetary Basalts

    NASA Technical Reports Server (NTRS)

    Caiazza, C. M.; Righter, K.; Gibson, E. K., Jr.; Chesley, J. T.; Ruiz, J.

    2004-01-01

    The isotopic system, 187Re 187Os, can be used to determine the role of crust and mantle in magma genesis. In order to apply the system to natural samples, we must understand variations in Re/Os concentrations. It is thought that low [Os] and [Re] in basalts can be attributed to sulfide (FeS) saturation, as Re behaves incompatibly to high degrees of evolution until sulfide saturation occurs [1]. Previous work has shown that lunar basalts are sulfide under-saturated, and mid-ocean ridge, ocean-island and Martian (shergottites) basalts are saturated [2,3]. However, little is known about arc basalts. In this study, basaltic rocks were analyzed across the Trans-Mexican Volcanic Belt.

  20. A Reaction Involving Oxygen and Metal Sulfides.

    ERIC Educational Resources Information Center

    Hill, William D. Jr.

    1986-01-01

    Describes a procedure for oxygen generation by thermal decomposition of potassium chlorate in presence of manganese dioxide, reacted with various sulfides. Provides a table of sample product yields for various sulfides. (JM)

  1. METAL INTERACTIONS AT SULFIDE MINERAL SURFACES: PART 3, METAL AFFINITIES IN SINGLE AND MULTIPLE ION ADSORPTION REACTIONS

    EPA Science Inventory

    Adsorption reactions of both single ions and multiple ion mixtures with sulfide minerals (chalcocite, galena, pyrite, and sphalerite) were investigated in the metal concentration range of 0.0001 to 0.00001 M. Chromium (III), iron (III), barium (II), cadmium (II), copper (II), nic...

  2. Copper isotope variations of copper-rich minerals in seafloor hydrothermal deposits and igneous rocks, measured by a femtosecond LA-MC-ICP-MS

    NASA Astrophysics Data System (ADS)

    Ikehata, K.; Ishibashi, J.; Suzuki, R.; Hirata, T.

    2013-05-01

    In recent years, the copper isotope systematics has seen an increased interest as a potential tool for understanding copper sources and geochemical processes of copper transport and deposition in ore-forming systems. The copper isotope variations of primary and secondary copper-rich minerals from modern (Mariana Trough) and ancient (Besshi-type and Kuroko-type volcanogenic massive sulfide deposits, Japan) seafloor hydrothermal deposits have been analyzed by a femtosecond-pulsed laser ablation multiple collector inductively coupled plasma mass spectrometry (fs-LA-MC-ICP-MS). The δ65Cu (where δ65Cu = [(65Cu/63Cu)sample/ (65Cu/63Cu)NIST-SRM976-1] × 1000) values of copper-rich sulfide minerals of chimney samples from active seafloor hydrothermal deposits are significantly large (δ65Cu = -0.7 to 4.0‰) compared to those of copper-rich minerals in ancient submarine hydrothermal deposits (δ65Cu = -0.3 to 0.4‰; e.g., Ikehata et al., 2011) and in igneous rocks (δ65Cu = -0.3 to 0.3‰; e.g., Ikehata et al., 2012). These large copper isotopic variations in the chimney samples are most likely explained in terms of a redox-controlled isotope fractionation during hydrothermal reworking of copper sulfides below sea floor or alteration of primary hydrothermal copper sulfides by seawater, involving the preferential incorporation of heavy copper isotopes in secondary Cu(II) solutions. These results also suggest that sub-seafloor recrystallization and metamorphic reequilibration may have reduced the original range of copper isotopes. Secondary malachite (δ65Cu = 2.6 to 3.0‰) and native copper (δ65Cu = 1.4 to 1.7‰) in the Besshi-type deposits have heavier copper isotopic values compared to precursor copper-rich minerals. These variations are mainly due to isotope fractionations during redox reactions (weathering) at low temperatures involving the preferential incorporation of heavy copper isotopes in secondary Cu(II) solutions.

  3. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false Hydrogen sulfide. 250.604 Section 250.604...-Workover Operations § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined...

  4. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false Hydrogen sulfide. 250.808 Section 250.808 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL... § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or...

  5. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false Hydrogen sulfide. 250.808 Section 250.808 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL... § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or...

  6. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Hydrogen sulfide. 250.808 Section 250.808 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL... § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or...

  7. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false Hydrogen sulfide. 250.504 Section 250.504...-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined...

  8. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.808 Section 250.808... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Production Safety Systems § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of...

  9. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.604 Section 250.604... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Workover Operations § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or...

  10. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.504 Section 250.504... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones known to contain hydrogen sulfide (H2S) or...

  11. 30 CFR 250.490 - Hydrogen sulfide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Hydrogen sulfide. 250.490 Section 250.490 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Hydrogen Sulfide § 250.490 Hydrogen sulfide. (a)...

  12. New data on the Hyrkkoelae native copper mineralization: A natural analogue for the long-term corrosion of copper canisters

    SciTech Connect

    Marcos, N.; Ahonen, L.; Bros, R.; Roos, P.; Suksi, J.; Oversby, V.

    1999-07-01

    The Hyrkkoelae U-Cu mineralization located in southwestern Finland is reassessed with reference to the corrosion mechanisms affecting the stability of native copper and the time-scales of corrosion processes. The mineral assemblage native copper--copper sulfide occurs in open fractures at several depth intervals within granite pegmatites (GP). The surfaces of these open fractures have accumulations of uranophane crystals and other unidentified uranyl compounds. The secondary uranium minerals are mainly distributed around copper sulfide grains. Microscopic intergrowths of copper sulfides and uranyl compounds also have been observed. Groundwater samples were collected from the vicinity of the Cu samples. The hydrogeochemical features of these samples indicate that the present conditions are oxidizing. The minimum age of U(VI) transport and deposition is about 200,000 years. This age is indicated by {sup 234}U/{sup 238}U and {sup 230}Th/{sup 234}U activity ratios of uranophane. The age of the hexavalent uranium precipitation may be somewhat later than the last influxes and/or demobilization of sulfur. The mineral assemblage native copper--copper oxide (cuprite) occurs only at one depth interval within altered granite pegmatite. The fracture surface was coated by smectite. The content of uranium in smectite was 69--75 ppm U. The {sup 234}U/{sup 238}U and {sup 230}Th/{sup 234}U activity ratios of smectite showed that it has been exposed to recent groundwaters (e.g., during the last million years). The pH of the groundwater at this interval was near neutral (6.9). The copper grains present at this fracture surface were as large as 1 mm in diameter and had rims of cuprite of 0.01 to 0.1 mm thick. The smallest grains were totally oxidized.

  13. The Effect of Oxygen Potential on the Sulfide Capacity for Slags Containing Multivalent Species

    NASA Astrophysics Data System (ADS)

    Allertz, Carl; Selleby, Malin; Sichen, Du

    2016-06-01

    The dependence of sulfide capacity on the oxygen partial pressure for slags containing multivalent species was investigated experimentally using a slag containing vanadium oxide. Copper-slag equilibration experiments were carried out at 1873 K (1600 °C) in the approximate oxygen partial pressure range 10-15.4 to 10-9 atm. The sulfide capacity was found to be strongly dependent on the oxygen potential in this slag system, increasing with the oxygen partial pressure. The sulfide capacity changed by more than two orders of magnitude over the oxygen partial pressure range. The effect of changing oxygen partial pressure was found to be much greater than the effect of changing slag composition at a fixed oxygen partial pressure.

  14. Sulfide Deposits from the East Pacific Rise Near 21{degrees}N.

    PubMed

    Hekinian, R; Fevrier, M; Bischoff, J L; Picot, P; Shanks, W C

    1980-03-28

    Massive sulfide deposits were discovered from the diving saucer Cyana on the accreting plate boundary region of the East Pacific Rise near 21 degrees N. The deposits form conical and tubular structures lying on a basaltic basement. Mineralogical and geochemical analyses showed two main types of intimately associated products: a polymetallic sulfide-rich material composed of pyrite and marcasite in association, zinc-rich phases, and copper-rich compounds, and an iron-rich oxide and hydroxide material (also called gossan) composed largely of goethite and limonite. Silicate phases such as opaline, silica, iron-silicon clay, and trace amounts of mica and zeolite are encountered in both types of material. Possible mechanisms for the formation of the sulfide deposits on the East Pacific Rise are discussed. PMID:17779603

  15. Sulfide deposits from the east Pacific rise near 21/sup 0/N

    SciTech Connect

    Hekinian, R.; Fevrier, M.; Bischoff, J.L.; Picot, P.; Shanks, W.C.

    1980-03-28

    Massive sulfide deposits were discovered from the diving saucer Cyana on the accreting plate boundary region of the East Pacific Rise near 21/sup 0/N. The deposits form conical and tubular structures lying on a basaltic basement. Mineralogical and geochemical analyses showed two main types of intimately associated products: a polymetallic sulfide-rich material composed of pyrite and marcasite in association, zinc-rich phases, and copper-rich compounds, and an iron-rich oxide and hydroxide material (also called gossan) composed largely of goethite and limonite. Silicate phases such as opaline, silica, iron-silicon clay, and trace amounts of mica and zeolite are encountered in both types of material. Possible mechanisms for the formation of the sulfide deposits on the East Pacific Rise are discussed.

  16. Copper Imbalances in Ruminants and Humans: Unexpected Common Ground1

    PubMed Central

    Suttle, Neville F.

    2012-01-01

    Ruminants are more vulnerable to copper deficiency than humans because rumen sulfide generation lowers copper availability from forage, increasing the risk of conditions such as swayback in lambs. Molybdenum-rich pastures promote thiomolybdate (TM) synthesis and formation of unabsorbable Cu-TM complexes, turning risk to clinical reality (hypocuprosis). Selection pressures created ruminant species with tolerance of deficiency but vulnerability to copper toxicity in alien environments, such as specific pathogen–free units. By contrast, cases of copper imbalance in humans seemed confined to rare genetic aberrations of copper metabolism. Recent descriptions of human swayback and the exploratory use of TM for the treatment of Wilson’s disease, tumor growth, inflammatory diseases, and Alzheimer’s disease have created unexpected common ground. The incidence of pre–hemolytic copper poisoning in specific pathogen–free lambs was reduced by an infection with Mycobacterium avium that left them more responsive to treatment with TM but vulnerable to long-term copper depletion. Copper requirements in ruminants and humans may need an extra allowance for the “copper cost” of immunity to infection. Residual cuproenzyme inhibition in TM-treated lambs and anomalies in plasma copper composition that appeared to depend on liver copper status raise this question “can chelating capacity be harnessed without inducing copper-deficiency in ruminants or humans?” A model of equilibria between exogenous (TM) and endogenous chelators (e.g., albumin, metallothionein) is used to predict risk of exposure and hypocuprosis; although risk of natural exposure in humans is remote, vulnerability to TM-induced copper deficiency may be high. Biomarkers of TM impact are needed, and copper chaperones for inhibited cuproenzymes are prime candidates. PMID:22983845

  17. Global transcriptional responses of Acidithiobacillus ferrooxidans Wenelen under different sulfide minerals.

    PubMed

    Latorre, Mauricio; Ehrenfeld, Nicole; Cortés, María Paz; Travisany, Dante; Budinich, Marko; Aravena, Andrés; González, Mauricio; Bobadilla-Fazzini, Roberto A; Parada, Pilar; Maass, Alejandro

    2016-01-01

    In order to provide new information about the adaptation of Acidithiobacillus ferrooxidans during the bioleaching process, the current analysis presents the first report of the global transcriptional response of the native copper mine strain Wenelen (DSM 16786) oxidized under different sulfide minerals. Microarrays were used to measure the response of At. ferrooxidans Wenelen to shifts from iron supplemented liquid cultures (reference state) to the addition of solid substrates enriched in pyrite or chalcopyrite. Genes encoding for energy metabolism showed a similar transcriptional profile for the two sulfide minerals. Interestingly, four operons related to sulfur metabolism were over-expressed during growth on a reduced sulfur source. Genes associated with metal tolerance (RND and ATPases type P) were up-regulated in the presence of pyrite or chalcopyrite. These results suggest that At. ferrooxidans Wenelen presents an efficient transcriptional system developed to respond to environmental conditions, namely the ability to withstand high copper concentrations. PMID:26476161

  18. High-resolution photoelectron spectroscopy analysis of sulfidation of brass at the rubber/brass interface

    NASA Astrophysics Data System (ADS)

    Ozawa, Kenichi; Kakubo, Takashi; Shimizu, Katsunori; Amino, Naoya; Mase, Kazuhiko; Komatsu, Takayuki

    2013-01-01

    High resolution photoelectron spectroscopy is utilized to investigate the chemical composition at the rubber/brass interface to elucidate the origin of strong adhesion as well as the degradation between rubber and brass. Special attention has been given to copper sulfides formed at the interface during the vulcanization reaction at 170 °C. At least five sulfur-containing species are identified in the adhesive interlayer including crystalline CuS and amorphous CuxS (x ≃ 2). These copper sulfide species are not uniformly distributed within the layer, but there exits the concentration gradation; the concentration of CuxS is high in the region on the rubber side and is diminished in the deeper region, while vice versa for that of CuS. Degradation of the interface adhesive strength by prolonged vulcanization arises from the decrease in the CuxS/CuS ratio accompanying desulfurization of the adhesive layer.

  19. Seasonal and spatial patterns of metals at a restored copper mine site. I. Stream copper and zinc

    USGS Publications Warehouse

    Bambic, D.G.; Alpers, C.N.; Green, P.G.; Fanelli, E.; Silk, W.K.

    2006-01-01

    Seasonal and spatial variations in metal concentrations and pH were found in a stream at a restored copper mine site located near a massive sulfide deposit in the Foothill copper-zinc belt of the Sierra Nevada, California. At the mouth of the stream, copper concentrations increased and pH decreased with increased streamflow after the onset of winter rain and, unexpectedly, reached extreme values 1 or 2 months after peaks in the seasonal hydrographs. In contrast, aqueous zinc and sulfate concentrations were highest during low-flow periods. Spatial variation was assessed in 400 m of reach encompassing an acidic, metal-laden seep. At this seep, pH remained low (2-3) throughout the year, and copper concentrations were highest. In contrast, the zinc concentrations increased with downstream distance. These spatial patterns were caused by immobilization of copper by hydrous ferric oxides in benthic sediments, coupled with increasing downstream supply of zinc from groundwater seepage.

  20. Mechanism of Mineral Phase Reconstruction for Improving the Beneficiation of Copper and Iron from Copper Slag

    NASA Astrophysics Data System (ADS)

    Guo, Zhengqi; Zhu, Deqing; Pan, Jan; Zhang, Feng

    2016-08-01

    To maximize the recovery of iron and copper from copper slag, the modification process by adding a compound additive (a mixture of hematite, pyrite and manganous oxide) and optimizing the cooling of the slag was studied. The phase reconstruction mechanism of the slag modification process was revealed by thermodynamic calculations, x-ray diffraction, optical microscopy and scanning electron microscopy. The results show that the synergy between the burnt lime and the compound additive promotes the generation of target minerals, such as magnetite and copper matte. In addition, the multifunctional compound additive is able to improve the fluidity of the molten slag, which facilitates the coalescence and growth of fine particles of the target minerals. As a result, the percentage of iron distributed in the form of magnetite increased from 32.9% to 65.1%, and that of the copper exiting in the form of metallic copper and copper sulfide simultaneously increased from 80.0% to 90.3%. Meanwhile, the grains of the target minerals in the modified slag grew markedly to a mean size of over 50 μm after slow cooling. Ultimately, the beneficiation efficiency of copper and iron was improved because of the ease with which the target minerals could be liberated.

  1. SULFIDE PRECIPITATION OF HEAVY METALS

    EPA Science Inventory

    The research program was initiated with the objective of evaluating a new process, the sulfide precipitation of heavy metals from industrial wastewaters. The process was expected to effect a more complete removal of heavy metals than conventional lime processing because of the mu...

  2. p-Chlorophenyl methyl sulfide

    Integrated Risk Information System (IRIS)

    p - Chlorophenyl methyl sulfide ; CASRN 123 - 09 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for N

  3. Transition metal sulfide loaded catalyst

    DOEpatents

    Maroni, Victor A.; Iton, Lennox E.; Pasterczyk, James W.; Winterer, Markus; Krause, Theodore R.

    1994-01-01

    A zeolite based catalyst for activation and conversion of methane. A zeolite support includes a transition metal (Mo, Cr or W) sulfide disposed within the micropores of the zeolite. The catalyst allows activation and conversion of methane to C.sub.2 + hydrocarbons in a reducing atmosphere, thereby avoiding formation of oxides of carbon.

  4. Copper cyanide

    Integrated Risk Information System (IRIS)

    Copper cyanide ; CASRN 544 - 92 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  5. Production of sulfur gases and carbon dioxide by synthetic weathering of crushed drill cores from the Santa Cruz porphyry copper deposit near Casa Grande, Pinal County, Arizona

    USGS Publications Warehouse

    Hinkle, M.E.; Ryder, J.L.; Sutley, S.J.; Botinelly, T.

    1990-01-01

    Samples of ground drill cores from the southern part of the Santa Cruz porphyry copper deposit, Casa Grande, Arizona, were oxidized in simulated weathering experiments. The samples were also separated into various mineral fractions and analyzed for contents of metals and sulfide minerals. The principal sulfide mineral present was pyrite. Gases produced in the weathering experiments were measured by gas chromatography. Carbon dioxide, oxygen, carbonyl sulfide, sulfur dioxide and carbon disulfide were found in the gases; no hydrogen sulfide, organic sulfides, or mercaptans were detected. Oxygen concentration was very important for production of the volatiles measured; in general, oxygen concentration was more important to gas production than were metallic element content, sulfide mineral content, or mineral fraction (oxide or sulfide) of the sample. The various volatile species also appeared to be interactive; some of the volatiles measured may have been formed through gas reactions. ?? 1990.

  6. Microstructural investigation of copper corrosion: Influence of humidity

    NASA Astrophysics Data System (ADS)

    Campin, Michael J.

    2003-10-01

    Copper is a critical material in electrical components and is subject to atmospheric corrosion. This study characterized the corrosion products formed when copper is exposed to environments containing activated oxygen species or sulfur containing species. Investigation of the oxides formed when copper is exposed to an electron-cyclotron resonance (ECR) O2 plasma has revealed the presence of both Cu2O and CuO. In addition, it was found that the presence of CuO on copper prevents sulfidation. Particular emphasis is placed on the product formed when Cu is exposed to a dilute (50--200 ppb) H2S atmosphere at low (0.5%) to high (80%) relative humidity (RH). An important observation was that the Cu2S growth rate is significantly higher for sulfides formed at low RH compared to high RH. In addition, it is found that for both low and high RH sulfidation, copper reacts to form the low chalcocite phase (Cu2S) as identified by X-ray and electron diffraction. Cross-section and plan-view TEM revealed that the Cu2S grains formed at high RH are 20--50 nm in size with a large amount of porosity, whereas the grains formed at low RH are 75--150+ nm and appear to undergo grain growth with little porosity. Finally, numerical modeling of an ideal diffusion process is used to demonstrate that point like sources can result in behavior similar to that observed for the rate of sulfidation at high RH.

  7. Dispersion strengthened copper

    DOEpatents

    Sheinberg, H.; Meek, T.T.; Blake, R.D.

    1990-01-09

    A composition of matter is described which is comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide. A method for making this composition of matter is also described. This invention relates to the art of powder metallurgy and, more particularly, it relates to dispersion strengthened metals.

  8. COPPER AND BRAIN FUNCTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing evidence shows that brain development and function are impaired when the brain is deprived of copper either through dietary copper deficiency or through genetic defects in copper transport. A number of copper-dependent enzymes whose activities are lowered by copper deprivation form the ba...

  9. Marine diagenesis of hydrothermal sulfide

    SciTech Connect

    Moammar, M.O.

    1985-01-01

    An attempt is made to discuss the artificial and natural oxidation and hydrolysis of hydrothermal sulfide upon interaction with normal seawater. Synthetic and natural ferrosphalerite particles used in kinetic oxidation and hydrolysis studies in seawater develop dense, crystalline coatings consisting of ordered and ferrimagnetic delta-(Fe, Zn)OOH. Due to the formation of this reactive diffusion barrier, the release of Zn into solution decreases rapidly, and sulfide oxidation is reduced to a low rate determined by the diffusion of oxygen through the oxyhydroxide film. This also acts as an efficient solvent for ions such as Zn/sup 2 +/, Ca/sup 2 +/, and possibly Cd/sup 2 +/, which contribute to the stabilization of the delta-FeOOH structure. The oxidation of sulfide occurs in many seafloor spreading areas, such as 21/sup 0/N on the East Pacific Ridge. In these areas the old surface of the sulfide chimneys are found to be covered by an orange stain, and sediment near the base of nonactive vents is also found to consist of what has been referred to as amorphous iron oxide and hydroxide. This thesis also discusses the exceedingly low solubility of zinc in seawater, from delta-(Fe, Zn)OOH and the analogous phase (zinc-ferrihydroxide) and the zinc exchange minerals, 10-A manganate and montmorillonite. The concentrations of all four are of the same magnitude (16, 36.4, and 12 nM, respectively) as the zinc concentration in deep ocean water (approx. 10 nM), which suggests that manganates and montmorillonite with iron oxyhydroxides control zinc concentration in the deep ocean.

  10. Development of novel copper-based sorbents for hot-gas cleanup. [Quarterly] technical report, September 1--November 30, 1993

    SciTech Connect

    Abbasian, J.; Hill, A.H.; Flytzani-Stephanopoulos, M.; Li Li

    1994-03-01

    The objective of this investigation is to evaluate two novel copper-based sorbents, namely copper-chromium and copper-cerium, for their effectiveness in removing hydrogen sulfide from fuel gas in the temperature range of 650{degree} to 850{degree}C. Such high temperatures will be required for the new generation of gas turbines (inlet >750{degree}C) in Integrated Gasification Combined Cycle (IGCC) systems. The effect of pre-reduction on the performance of the sorbents as well as the rate of different reactions occurring in cyclic sulfidation/regeneration, were studied in a thermogravimetric analyzer (TGA). Sulfidation was conducted with and without H{sub 2} and H{sub 2}O, and with and without pre-reduction in H{sub 2} or H{sub 2}/H{sub 2}O. The results of these tests indicate that reduction and regeneration of both sorbents occurs rapidly. Sulfidation of CuCr{sub 2}O{sub 4}, in H{sub 2}O-free and H{sub 2}-/H{sub 2}O-free gas indicates the possible sulfidation of both copper and chromium. Small quantities of SO{sub 2}, were released during sulfidation suggesting the possible oxidation of H{sub 2}S by the sorbent. Regeneration of the CuCr{sub 2}O{sub 4} was complete while regeneration of the CuO-CeO{sub 2} indicated possible limited sulfate formation.

  11. Sulfide-Driven Microbial Electrosynthesis

    SciTech Connect

    Gong, YM; Ebrahim, A; Feist, AM; Embree, M; Zhang, T; Lovley, D; Zengler, K

    2013-01-01

    Microbial electrosynthesis, the conversion of carbon dioxide to organic molecules using electricity, has recently been demonstrated for acetogenic microorganisms, such as Sporomusa ovata. The energy for reduction of carbon dioxide originates from the hydrolysis of water on the anode, requiring a sufficiently low potential. Here we evaluate the use of sulfide as an electron source for microbial electrosynthesis. Abiotically oxidation of sulfide on the anode yields two electrons. The oxidation product, elemental sulfur, can be further oxidized to sulfate by Desulfobulbus propionicus, generating six additional electrons in the process. The eight electrons generated from the combined abiotic and biotic steps were used to reduce carbon dioxide to acetate on a graphite cathode by Sporomusa ovata at a rate of 24.8 mmol/day.m(2). Using a strain of Desulfuromonas as biocatalyst on the anode resulted in an acetate production rate of 49.9 mmol/day.m(2), with a Coulombic efficiency of over 90%. These results demonstrate that sulfide can serve effectively as an alternative electron donor for microbial electrosynthesis.

  12. Development of novel copper-based sorbents for hot-gas cleanup. [Quarterly] technical report, December 1, 1991--February 29, 1992

    SciTech Connect

    Abbasian, J.; Hill, A.H.; Wangerow, J.R.; Flytzani-Stephanopoulos, M.; Bo, L.; Patel, C.

    1992-08-01

    The objective of this investigation is to evaluate several novel copper-based binary oxides for their suitability as regenerable sorbents for hot gas cleanup application in the temperature range of 650{degrees} to 850{degrees}C. To achieve this objective, several novel copper-based binary oxide sorbents will be prepared. Experimental tests will be conducted at ambient pressure to determine the stability, sulfidation capacity, regenerability, and sulfidation kinetics of the novel sorbents. Tests will also be conducted at high pressure for the determination of the sulfidation reactivity, regenerability, and durability of the sorbents. The attrition characteristics of the sorbents will also be determined.

  13. Synthesis, characterization, and reactivity of sulfided hexanuclear molybdenum cluster compounds

    SciTech Connect

    Spink, D.

    1990-09-21

    Hexanuclear molybdenum clusters with mixed chloride and sulfide bridging ligands were prepared by reacting {alpha}-MoCl{sub 2} with sodium hydrosulfide in the presence of sodium butoxide. The resulting species, Mo{sub 6}Cl{sub (8-x)}S{sub x}{center dot}npy(x {congruent} 3.6, n {congruent} 4, py = pyridine), was pyrophoric and insoluble. The mixed sulfide chloride cluster species Mo{sub 6}S{sub 4}Cl{sub 4}{center dot}6OPEt{sub 3} and Mo{sub 6}S{sub {approximately}5}Cl{sub {approximately}3}{center dot}6PEt{sub 3} and Mo{sub 6}S{sub 8}{center dot}6PEt{sub 3} were isolated and characterized. Phosphorus-31 nuclear magnetic resonance, electron paramagnetic resonance, and UV/visible spectra were obtained for each fraction. The completely sulfided cluster, Mo{sub 6}S{sub 8}{center dot}6PEt{sub 3}, was prepared similarly and used in various experiments as a possible precursor to Chevrel phase materials of the type Mo{sub 6}S{sub 8}or M{sub n}Mo{sub 6}S{sub 8}. With the goal of removing all of the triethylphosphine ligands, Mo{sub 6}S{sub 8}{center dot}6PEt{sub 3} was reacted with the transition metal carbonyls molybdenum hexacarbonyl and dicobalt octacarbonyl. Reaction on the molecular sulfide cluster with copper(I) chloride in toluene gave a completely insoluble product. The reaction of Mo{sub 6}S{sub 8}{center dot}6PEt{sub 3} with propylene sulfide gave a product whose infrared spectra showed only very weak peaks associated with coordinated triethylphosphine. The elemental analysis of this product fit the formula Mo{sub 6}S{sub 8}{center dot}5SPEt{sub 3}. Reactivity of the outer ligands of the Mo{sub 6}S{sub 8}{center dot}npy and Mo{sub 6}S{sub 8}{center dot}(6{minus}x)PrNH{sub x} clusters were investigated. Crystalline Mo{sub 6}S{sub 8}{center dot}6THT was recovered from the reaction of the n-propylamine derivative with THT. A crystal structure determination was done. 87 refs., 12 fig., 15 tabs.

  14. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false Hydrogen sulfide. 250.504 Section 250.504... § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined in § 250.490 of...

  15. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Hydrogen sulfide. 250.604 Section 250.604... § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined in § 250.490 of...

  16. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false Hydrogen sulfide. 250.504 Section 250.504... § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined in § 250.490 of...

  17. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false Hydrogen sulfide. 250.604 Section 250.604... § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined in § 250.490 of...

  18. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false Hydrogen sulfide. 250.604 Section 250.604... § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined in § 250.490 of...

  19. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Hydrogen sulfide. 250.504 Section 250.504... § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined in § 250.490 of...

  20. Rapid Synthesis of Nonstoichiometric Lanthanum Sulfide

    NASA Technical Reports Server (NTRS)

    Matsuda, S.; Shapiro, E.; Danielson, L.; Hardister, H.

    1987-01-01

    New process relatively fast and simple. Improved method of synthesizing nonstoichiometric lanthanum sulfide faster and simpler. Product purer because some of prior sources of contamination eliminated.

  1. Molybdenum sulfide/carbide catalysts

    DOEpatents

    Alonso, Gabriel; Chianelli, Russell R.; Fuentes, Sergio; Torres, Brenda

    2007-05-29

    The present invention provides methods of synthesizing molybdenum disulfide (MoS.sub.2) and carbon-containing molybdenum disulfide (MoS.sub.2-xC.sub.x) catalysts that exhibit improved catalytic activity for hydrotreating reactions involving hydrodesulfurization, hydrodenitrogenation, and hydrogenation. The present invention also concerns the resulting catalysts. Furthermore, the invention concerns the promotion of these catalysts with Co, Ni, Fe, and/or Ru sulfides to create catalysts with greater activity, for hydrotreating reactions, than conventional catalysts such as cobalt molybdate on alumina support.

  2. Preparation of amorphous sulfide sieves

    DOEpatents

    Siadati, Mohammad H.; Alonso, Gabriel; Chianelli, Russell R.

    2006-11-07

    The present invention involves methods and compositions for synthesizing catalysts/porous materials. In some embodiments, the resulting materials are amorphous sulfide sieves that can be mass-produced for a variety of uses. In some embodiments, methods of the invention concern any suitable precursor (such as thiomolybdate salt) that is exposed to a high pressure pre-compaction, if need be. For instance, in some cases the final bulk shape (but highly porous) may be same as the original bulk shape. The compacted/uncompacted precursor is then subjected to an open-flow hot isostatic pressing, which causes the precursor to decompose and convert to a highly porous material/catalyst.

  3. 40 CFR 425.03 - Sulfide analytical methods and applicability.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Provisions § 425.03 Sulfide analytical methods and applicability. (a) The potassium ferricyanide titration... the potassium ferricyanide titration method for the determination of sulfide in wastewaters...

  4. Synthesis and Optical Properties of Sulfide Nanoparticles Prepared in Dimethylsulfoxide

    SciTech Connect

    Li, Yuebin; Ma, Lun; Zhang, Xing; Joly, Alan G.; Liu, Zuli; Chen, Wei

    2008-11-01

    Many methods have been reported for the formation of sulfide nanoparticles by the reaction of metallic salts with sulfide chemical sources in aqueous solutions or organic solvents. Here, we report the formation of sulfide nanoparticles in dimethylsulfoxide (DMSO) by boiling metallic salts without sulfide sources. The sulfide sources are generated from the boiling of DMSO and react with metallic salts to form sulfide nanoparticles. In this method DMSO functions as a solvent and a sulfide source as well as a stabilizer for the formation of the nanoparticles. The recipe is simple and economical making sulfide nanoparticles formed in this way readily available for many potential applications.

  5. Response of sulfide:quinone oxidoreductase to sulfide exposure in the echiuran worm Urechis unicinctus.

    PubMed

    Ma, Yu-Bin; Zhang, Zhi-Feng; Shao, Ming-Yu; Kang, Kyoung-Ho; Shi, Xiao-Li; Dong, Ying-Ping; Li, Jin-Long

    2012-04-01

    Sulfide is a natural, widely distributed, poisonous substance, and sulfide:quinone oxidoreductase (SQR) is responsible for the initial oxidation of sulfide in mitochondria. In this study, we examined the response of SQR to sulfide exposure (25, 50, and 150 μM) at mRNA, protein, and enzyme activity levels in the body wall and hindgut of the echiuran worm Urechis unicinctus, a benthic organism living in marine sediments. The results revealed SQR mRNA expression during sulfide exposure in the body wall and hindgut increased in a time- and concentration-dependent manner that increased significantly at 12 h and continuously increased with time. At the protein level, SQR expression in the two tissues showed a time-dependent relationship that increased significantly at 12 h in 50 μM sulfide and 6 h in 150 μM, and then continued to increase with time while no significant increase appeared after 25 μM sulfide exposure. SQR enzyme activity in both tissues increased significantly in a time-dependent manner after 50 μM sulfide exposure. We concluded that SQR expression could be induced by sulfide exposure and that the two tissues studied have dissimilar sulfide metabolic patterns. A U. unicinctus sulfide-induced detoxification mechanism was also discussed. PMID:21997848

  6. Variation in Sulfide Tolerance of Photosystem II in Phylogenetically Diverse Cyanobacteria from Sulfidic Habitats

    PubMed Central

    Miller, Scott R.; Bebout, Brad M.

    2004-01-01

    Physiological and molecular phylogenetic approaches were used to investigate variation among 12 cyanobacterial strains in their tolerance of sulfide, an inhibitor of oxygenic photosynthesis. Cyanobacteria from sulfidic habitats were found to be phylogenetically diverse and exhibited an approximately 50-fold variation in photosystem II performance in the presence of sulfide. Whereas the degree of tolerance was positively correlated with sulfide levels in the environment, a strain's phenotype could not be predicted from the tolerance of its closest relatives. These observations suggest that sulfide tolerance is a dynamic trait primarily shaped by environmental variation. Despite differences in absolute tolerance, similarities among strains in the effects of sulfide on chlorophyll fluorescence induction indicated a common mode of toxicity. Based on similarities with treatments known to disrupt the oxygen-evolving complex, it was concluded that sulfide toxicity resulted from inhibition of the donor side of photosystem II. PMID:14766549

  7. Variation in sulfide tolerance of photosystem II in phylogenetically diverse cyanobacteria from sulfidic habitats

    NASA Technical Reports Server (NTRS)

    Miller, Scott R.; Bebout, Brad M.

    2004-01-01

    Physiological and molecular phylogenetic approaches were used to investigate variation among 12 cyanobacterial strains in their tolerance of sulfide, an inhibitor of oxygenic photosynthesis. Cyanobacteria from sulfidic habitats were found to be phylogenetically diverse and exhibited an approximately 50-fold variation in photosystem II performance in the presence of sulfide. Whereas the degree of tolerance was positively correlated with sulfide levels in the environment, a strain's phenotype could not be predicted from the tolerance of its closest relatives. These observations suggest that sulfide tolerance is a dynamic trait primarily shaped by environmental variation. Despite differences in absolute tolerance, similarities among strains in the effects of sulfide on chlorophyll fluorescence induction indicated a common mode of toxicity. Based on similarities with treatments known to disrupt the oxygen-evolving complex, it was concluded that sulfide toxicity resulted from inhibition of the donor side of photosystem II.

  8. Catalyst and process for oxidizing hydrogen sulfide

    SciTech Connect

    Hass, R.H.; Fullerton; Ward, J.W.; Yorba, L.

    1984-04-24

    Catalysts comprising bismuth and vanadium components are highly active and stable, especially in the presence of water vapor, for oxidizing hydrogen sulfide to sulfur or SO/sub 2/. Such catalysts have been found to be especially active for the conversion of hydrogen sulfide to sulfur by reaction with oxygen or SO/sub 2/.

  9. New biologically active hydrogen sulfide donors.

    PubMed

    Roger, Thomas; Raynaud, Francoise; Bouillaud, Frédéric; Ransy, Céline; Simonet, Serge; Crespo, Christine; Bourguignon, Marie-Pierre; Villeneuve, Nicole; Vilaine, Jean-Paul; Artaud, Isabelle; Galardon, Erwan

    2013-11-25

    Generous donors: The dithioperoxyanhydrides (CH3 COS)2 , (PhCOS)2 , CH3 COSSCO2 Me and PhCOSSCO2 Me act as thiol-activated hydrogen sulfide donors in aqueous buffer solution. The most efficient donor (CH3 COS)2 can induce a biological response in cells, and advantageously replace hydrogen sulfide in ex vivo vascular studies. PMID:24115650

  10. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false Hydrogen sulfide. 250.808 Section 250.808 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE... Safety Systems § 250.808 Hydrogen sulfide. Production operations in zones known to contain...

  11. Ammonia and hydrogen sulfide removal using biochar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reducing ammonia and hydrogen sulfide emissions from livestock facilities is an important issue for many communities and livestock producers. Ammonia has been regarded as odorous, precursor for particulate matter (PM), and contributed to livestock mortality. Hydrogen sulfide is highly toxic at elev...

  12. Cross-Comparison of Leaching Strains Isolated from Two Different Regions: Chambishi and Dexing Copper Mines

    PubMed Central

    Ngom, Baba; Liang, Yili; Liu, Xueduan

    2014-01-01

    A cross-comparison of six strains isolated from two different regions, Chambishi copper mine (Zambia, Africa) and Dexing copper mine (China, Asia), was conducted to study the leaching efficiency of low grade copper ores. The strains belong to the three major species often encountered in bioleaching of copper sulfide ores under mesophilic conditions: Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, and Leptospirillum ferriphilum. Prior to their study in bioleaching, the different strains were characterized and compared at physiological level. The results revealed that, except for copper tolerance, strains within species presented almost similar physiological traits with slight advantages of Chambishi strains. However, in terms of leaching efficiency, native strains always achieved higher cell density and greater iron and copper extraction rates than the foreign microorganisms. In addition, microbial community analysis revealed that the different mixed cultures shared almost the same profile, and At. ferrooxidans strains always outcompeted the other strains. PMID:25478575

  13. Measurement of labile copper in wine by medium exchange stripping potentiometry utilising screen printed carbon electrodes.

    PubMed

    Clark, Andrew C; Kontoudakis, Nikolaos; Barril, Celia; Schmidtke, Leigh M; Scollary, Geoffrey R

    2016-07-01

    The presence of copper in wine is known to impact the reductive, oxidative and colloidal stability of wine, and techniques enabling measurement of different forms of copper in wine are of particular interest in understanding these spoilage processes. Electrochemical stripping techniques developed to date require significant pretreatment of wine, potentially disturbing the copper binding equilibria. A thin mercury film on a screen printed carbon electrode was utilised in a flow system for the direct analysis of labile copper in red and white wine by constant current stripping potentiometry with medium exchange. Under the optimised conditions, including an enrichment time of 500s and constant current of 1.0μA, the response range was linear from 0.015 to 0.200mg/L. The analysis of 52 red and white wines showed that this technique generally provided lower labile copper concentrations than reported for batch measurement by related techniques. Studies in a model system and in finished wines showed that the copper sulfide was not measured as labile copper, and that loss of hydrogen sulfide via volatilisation induced an increase in labile copper within the model wine system. PMID:27154696

  14. Weathering of sulfides on Mars

    NASA Technical Reports Server (NTRS)

    Burns, Roger G.; Fisher, Duncan S.

    1987-01-01

    Pyrrhotite-pentlandite assemblages in mafic and ultramafic igneous rocks may have contributed significantly to the chemical weathering reactions that produce degradation products in the Martian regolith. By analogy and terrestrial processes, a model is proposed whereby supergene alteration of these primary Fe-Ni sulfides on Mars has generated secondary sulfides (e.g., pyrite) below the water table and produced acidic groundwater containing high concentrations of dissolved Fe, Ni, and sulfate ions. The low pH solutions also initiated weathering reactions of igneous feldspars and ferromagnesian silicates to form clay silicate and ferric oxyhydroxide phases. Near-surface oxidation and hydrolysis of ferric sulfato-and hydroxo-complex ions and sols formed gossan above the water table consisting of poorly crystalline hydrated ferric sulfates (e.g., jarosite), oxides (ferrihydrite, goethite), and silica (opal). Underlying groundwater, now permafrost contains hydroxo sulfato complexes of Fe, Al, Mg, Ni, which may be stabilized in frozen acidic solutions beneath the surface of Mars. Sublimation of permafrost may replenish colloidal ferric oxides, sulfates, and phyllosilicates during dust storms on Mars.

  15. Percutaneous absorption of selenium sulfide

    SciTech Connect

    Farley, J.; Skelly, E.M.; Weber, C.B.

    1986-01-01

    The purpose of this study was to determine selenium levels in the urine of Tinea patients before and after overnight application of a 2.5% selenium sulfide lotion. Selenium was measured by atomic absorption spectroscopy (AAS). Hydride generation and carbon rod atomization were studied. It was concluded from this study that selenium is absorbed through intact skin. Selenium is then excreted, at least partially, in urine, for at least a week following treatment. The data show that absorption and excretion of selenium vary on an individual basis. Selenium levels in urine following a single application of selenium sulfide lotion do not indicate that toxic amounts of selenium are being absorbed. Repeated treatments with SeS/sub 2/ result in selenium concentrations in urine which are significantly higher than normal. Significant matrix effects are observed in the carbon rod atomization of urine samples for selenium determinations, even in the presence of a matrix modifier such as nickel. The method of standard additions is required to obtain accurate results in the direct determination of selenium in urine by carbon rod AAS.

  16. Copper and Copper Proteins in Parkinson's Disease

    PubMed Central

    Rivera-Mancia, Susana; Diaz-Ruiz, Araceli; Tristan-Lopez, Luis; Rios, Camilo

    2014-01-01

    Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson's disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson's disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson's disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson's disease and that a mutation in ATP7B could be associated with Parkinson's disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology. PMID:24672633

  17. Characterization of low dimensional molybdenum sulfide nanostructures

    SciTech Connect

    Camacho-Bragado, G. Alejandra; Elechiguerra, Jose Luis; Yacaman, Miguel Jose

    2008-03-15

    It is presented a detailed structural characterization of a nanostructured form of molybdenum disulfide. The material consists of a layer of highly textured molybdenum sulfide growing off a molybdenum dioxide core. The structure and chemical composition of the synthesized nanostructured sulfide was compared to two well-known forms of molybdenum disulfide, i.e. a commercial molybdenite sample and a poorly crystalline sulfide. X-ray diffraction, high-resolution electron microscopy and electron diffraction showed that the material reported here presents crystalline nanodomains with a crystal structure corresponding to the 2H polytype of molybdenum disulfide. X-ray photoelectron spectroscopy was used to demonstrate the differences between our sulfide and other materials such as amorphous MoS{sub 3}, oxysulfides and poorly crystalline MoS{sub 2}, corroborating the molybdenite-2H stacking in this form of sulfide. The material under study showed a high proportion of crystalline planes different from the basal plane.

  18. Synthesis of magnetic rhenium sulfide composite nanoparticles

    NASA Astrophysics Data System (ADS)

    Tang, Naimei; Tu, Weixia

    2009-10-01

    Rhenium sulfide nanoparticles are associated with magnetic iron oxide through coprecipitation of iron salts with tetramethylammonium hydroxide. Sizes of the formed magnetic rhenium sulfide composite particles are in the range 5.5-12.5 nm. X-ray diffraction and energy-dispersive analysis of X-rays spectra demonstrate the coexistence of Fe 3O 4 and ReS 2 in the composite particle, which confirm the formation of the magnetic rhenium sulfide composite nanoparticles. The association of rhenium sulfide with iron oxide not only keeps electronic state and composition of the rhenium sulfide nanoparticles, but also introduces magnetism with the level of 24.1 emu g -1 at 14 kOe. Surface modification with monocarboxyl-terminated poly(ethylene glycol) (MPEG-COOH) has the role of deaggregating the composite nanoparticles to be with average hydrodynamic size of 27.3 nm and improving the dispersion and the stability of the composite nanoparticles in water.

  19. Hydrogen sulfide pollution in wastewater treatment facilities

    SciTech Connect

    AlDhowalia, K.H. )

    1987-01-01

    The hydrogen sulfide (H{sub 2}S) found in wastewater collection systems and wastewater treatment facilities results from the bacterial reduction of the sulfate ion (SO{sub 4}). Hydrogen sulfide is a gas that occurs both in the sewer atmosphere and as a dissolved gas in the wastewater. When raw wastewater first enters the wastewater treatment facility by gravity most of the hydrogen sulfide is in the gaseous phase and will escape into the atmosphere at the inlet structures. Also some of the dissolved hydrogen sulfide will be released at points of turbulance such as at drops in flow, flumes, or aeration chambers. Several factors can cause excessive hydrogen sulfide concentrations in a sewerage system. These include septic sewage, long flow times in the sewerage system, high temperatures, flat sewer grades, and poor ventilation. These factors are discussed in this paper.

  20. Copper speciation in variably toxic sediments at the Ely Copper Mine, Vermont, United States

    USGS Publications Warehouse

    Kimball, Bryn E.; Foster, Andrea L.; Seal, Robert; Piatak, Nadine; Webb, Samuel M.; Hammarstrom, Jane M.

    2016-01-01

    At the Ely Copper Mine Superfund site, Cu concentrations exceed background values in both streamwater (160–1200 times) and sediments (15–79 times). Previously, these sediment samples were incubated with laboratory test organisms, and they exhibited variable toxicity for different stream sites. In this study we combined bulk- and microscale techniques to determine Cu speciation and distribution in these contaminated sediments on the basis of evidence from previous work that Cu was the most important stressor in this environment and that variable observed toxicity could have resulted from differences in Cu speciation. Copper speciation results were similar at microscopic and bulk scales. The major Cu species in the more toxic samples were sorbed or coprecipitated with secondary Mn (birnessite) and Fe minerals (jarosite and goethite), which together accounted for nearly 80% of the total Cu. The major Cu species in the less toxic samples were Cu sulfides (chalcopyrite and a covellite-like phase), making up about 80–95% of the total Cu, with minor amounts of Cu associated with jarosite or goethite. These Cu speciation results are consistent with the toxicity results, considering that Cu sorbed or coprecipitated with secondary phases at near-neutral pH is relatively less stable than Cu bound to sulfide at lower pH. The more toxic stream sediment sites were those that contained fewer detrital sulfides and were upstream of the major mine waste pile, suggesting that removal and consolidation of sulfide-bearing waste piles on site may not eliminate all sources of bioaccessible Cu.

  1. Copper Speciation in Variably Toxic Sediments at the Ely Copper Mine, Vermont, United States.

    PubMed

    Kimball, Bryn E; Foster, Andrea L; Seal, Robert R; Piatak, Nadine M; Webb, Samuel M; Hammarstrom, Jane M

    2016-02-01

    At the Ely Copper Mine Superfund site, Cu concentrations exceed background values in both streamwater (160-1200 times) and sediments (15-79 times). Previously, these sediment samples were incubated with laboratory test organisms, and they exhibited variable toxicity for different stream sites. In this study we combined bulk- and microscale techniques to determine Cu speciation and distribution in these contaminated sediments on the basis of evidence from previous work that Cu was the most important stressor in this environment and that variable observed toxicity could have resulted from differences in Cu speciation. Copper speciation results were similar at microscopic and bulk scales. The major Cu species in the more toxic samples were sorbed or coprecipitated with secondary Mn (birnessite) and Fe minerals (jarosite and goethite), which together accounted for nearly 80% of the total Cu. The major Cu species in the less toxic samples were Cu sulfides (chalcopyrite and a covellite-like phase), making up about 80-95% of the total Cu, with minor amounts of Cu associated with jarosite or goethite. These Cu speciation results are consistent with the toxicity results, considering that Cu sorbed or coprecipitated with secondary phases at near-neutral pH is relatively less stable than Cu bound to sulfide at lower pH. The more toxic stream sediment sites were those that contained fewer detrital sulfides and were upstream of the major mine waste pile, suggesting that removal and consolidation of sulfide-bearing waste piles on site may not eliminate all sources of bioaccessible Cu. PMID:26734712

  2. Alternative Anode Reaction for Copper Electrowinning

    SciTech Connect

    Not Available

    2005-07-01

    This report describes a project funded by the Department of Energy, with additional funding from Bechtel National, to develop a copper electrowinning process with lower costs and lower emissions than the current process. This new process also includes more energy efficient production by using catalytic-surfaced anodes and a different electrochemical couple in the electrolyte, providing an alternative oxidation reaction that requires up to 50% less energy than is currently required to electrowin the same quantity of copper. This alternative anode reaction, which oxidizes ferric ions to ferrous, with subsequent reduction back to ferric using sulfur dioxide, was demonstrated to be technically and operationally feasible. However, pure sulfur dioxide was determined to be prohibitively expensive and use of a sulfur burner, producing 12% SO{sub 2}, was deemed a viable alternative. This alternate, sulfur-burning process requires a sulfur burner, waste heat boiler, quench tower, and reaction towers. The electrolyte containing absorbed SO{sub 2} passes through activated carbon to regenerate the ferrous ion. Because this reaction produces sulfuric acid, excess acid removal by ion exchange is necessary and produces a low concentration acid suitable for leaching oxide copper minerals. If sulfide minerals are to be leached or the acid unneeded on site, hydrogen was demonstrated to be a potential reductant. Preliminary economics indicate that the process would only be viable if significant credits could be realized for electrical power produced by the sulfur burner and for acid if used for leaching of oxidized copper minerals on site.

  3. Experimental Investigation and Modeling of Copper Smelting Slags

    NASA Astrophysics Data System (ADS)

    Starodub, Konstantin; Kuminova, Yaroslava; Dinsdale, Alan; Cheverikin, Vladimir; Filichkina, Vera; Saynazarov, Abdukahhar; Khvan, Alexandra; Kondratiev, Alex

    2016-07-01

    Effective extraction of copper from sulfide ores requires careful operation of a copper smelter, which in turn depends very much on chemistry of the feed and resulted slag and matte. For example, chemical composition of copper smelting slags has to be in a certain range to ensure that their properties are within specific limits. Disobeying these rules may lead to complications in smelting operation, poor quality of the copper products, and premature shutdown of the copper smelter. In the present paper the microstructure and phase composition of slags from the Almalyk copper flash smelter were investigated experimentally and then modeled thermodynamically to evaluate potential ways of improvement and optimization of the copper smelting process and its products. The slag samples were taken at different stages of the copper smelting process: on slag tapping, after slag transportation to a deposition site, and at the site. Experimental investigation included the XRD, XRF, and SEM techniques, which were also confirmed by the traditional wet chemistry analysis. Thermodynamic modeling was carried out using thermochemical software package MTDATA, which enables thermodynamic and physical properties of the matte, slag, and gas phases to be calculated in a wide range of temperatures, pressures, and chemical compositions. In addition, slag viscosities and corresponding matte settling rates were estimated using the modified Urbain and Utigard-Warczok models, and the Hadamard-Rybczynski equation, respectively. It was found that the copper content in the slags may vary significantly depending on the location of slag sampling. Cu was found to be present as sulfide particles, almost no Cu was found to be dissolved in the slag. Analysis of microstructure and phase composition showed that major phase found in the samples is fayalite, while other phases are complex spinels (based on magnetite), different sulfides, and a glass-like phase. Thermodynamic calculations demonstrated the

  4. Corrosion of Cu-Ni alloys in sulfide-polluted seawater

    SciTech Connect

    Al-Hajji, J.N. . Mechanical Engineering Dept.); Reda, M.R. . Chemical Engineering Dept.)

    1993-10-01

    A study of the corrosion of copper-nickel (Cu-Ni) alloys showed hydrodynamic conditions increased the corrosion rate (I[sub corr]) significantly by reducing the sulfide concentration polarization. Pre-exposure to oxidation products of dissolved sulfide and elemental sulfur (S) increased I[sub corr] of the alloys in seawater significantly. Pre-exposure to nitrite and chromate decreased I[sub corr] by almost 2 orders of magnitude for alloys of 90% Cu-10% Ni and 70% Cu-30% Ni. However, cyclic polarization curves for both alloys pre-exposed to chromate and nitrite showed the passivators caused severe localized corrosion for the 70% Cu-30% Ni alloy only by transition from the active to passive state. The corrosion mechanism of the 90% Cu-10% Ni alloy differed from that of the 70% Cu-30% Ni alloy in quiescent sulfide-polluted seawater. A four-part corrosion mechanism was proposed. The rate of sulfide ion diffusion to the alloy-solution interface always was the rate determining step for corrosion of the alloy of higher Ni content, whereas different kinetics of the reaction determined I[sub corr] of the second alloy.

  5. A computational study of adhesion between rubber and metal sulfides at rubber-brass interface

    NASA Astrophysics Data System (ADS)

    Ling, Chian Ye; Hirvi, Janne T.; Suvanto, Mika; Bazhenov, Andrey S.; Ajoviita, Tommi; Markkula, Katriina; Pakkanen, Tapani A.

    2015-05-01

    Computational study at level of density functional theory has been carried out in order to investigate the adhesion between rubber and brass plated steel cord, which has high importance in tire manufacturing. Adsorption of natural rubber based adsorbate models has been studied on zinc sulfide, ZnS(1 1 0), and copper sulfide, Cu2S(1 1 1) and CuS(0 0 1), surfaces as the corresponding phases are formed in adhesive interlayer during rubber vulcanization. Saturated hydrocarbons exhibited weak interactions, whereas unsaturated hydrocarbons and sulfur-containing adsorbates interacted with the metal atoms of sulfide surfaces more strongly. Sulfur-containing adsorbates interacted with ZnS(1 1 0) surface stronger than unsaturated hydrocarbons, whereras both Cu2S(1 1 1) and CuS(0 0 1) surfaces showed opposite adsorption preference as unsaturated hydrocarbons adsorbed stronger than sulfur-containing adsorbates. The different interaction strength order can play role in rubber-brass adhesion with different relative sulfide concentrations. Moreover, Cu2S(1 1 1) surface exhibits higher adsorption energies than CuS(0 0 1) surface, possibly indicating dominant role of Cu2S in the adhesion between rubber and brass.

  6. Transient Kinetic Analysis of Hydrogen Sulfide Oxidation Catalyzed by Human Sulfide Quinone Oxidoreductase.

    PubMed

    Mishanina, Tatiana V; Yadav, Pramod K; Ballou, David P; Banerjee, Ruma

    2015-10-01

    The first step in the mitochondrial sulfide oxidation pathway is catalyzed by sulfide quinone oxidoreductase (SQR), which belongs to the family of flavoprotein disulfide oxidoreductases. During the catalytic cycle, the flavin cofactor is intermittently reduced by sulfide and oxidized by ubiquinone, linking H2S oxidation to the electron transfer chain and to energy metabolism. Human SQR can use multiple thiophilic acceptors, including sulfide, sulfite, and glutathione, to form as products, hydrodisulfide, thiosulfate, and glutathione persulfide, respectively. In this study, we have used transient kinetics to examine the mechanism of the flavin reductive half-reaction and have determined the redox potential of the bound flavin to be -123 ± 7 mV. We observe formation of an unusually intense charge-transfer (CT) complex when the enzyme is exposed to sulfide and unexpectedly, when it is exposed to sulfite. In the canonical reaction, sulfide serves as the sulfur donor and sulfite serves as the acceptor, forming thiosulfate. We show that thiosulfate is also formed when sulfide is added to the sulfite-induced CT intermediate, representing a new mechanism for thiosulfate formation. The CT complex is formed at a kinetically competent rate by reaction with sulfide but not with sulfite. Our study indicates that sulfide addition to the active site disulfide is preferred under normal turnover conditions. However, under pathological conditions when sulfite concentrations are high, sulfite could compete with sulfide for addition to the active site disulfide, leading to attenuation of SQR activity and to an alternate route for thiosulfate formation. PMID:26318450

  7. Primordial Xenon in Allende Sulfides

    NASA Astrophysics Data System (ADS)

    Lee, J. T.; Manuel, O. K.

    1995-09-01

    The Allende C3V carbonaceous chondrite incorporated isotopically anomalous components of several medium-heavy elements (Z=36-62) from nucleosynthesis [1]. Isotopically distinct Xe (Z=54) has been found in grains ranging from several _ to a few mm in size. Diamond [2] is the host of Xe that is enriched in isotopes produced by the very rapid p- and r-processes in a supernova explosion [3]. Silicon carbide [4] is the host of Xe that is enriched in the middle isotopes, 128-132Xe, produced by slow neutron capture [3] before a star reaches the supernova stage. The present study was undertaken to identify the isotopic composition of primitive Xe initially trapped in sulfides of the Allende meteorite. Two FeS mineral separates were analyzed by stepwise heating. One sample was first irradiated in a neutron flux to generate a tracer isotope, 131*Xe, by the 130Te(n, gamma beta-)131*Xe reaction. The release pattern of this tracer isotope, 131*Xe, closely paralleled the release of primordial 132Xe up to 950 degrees C, when the sulfide melted and released the bulk of its trapped Xe (Figure 1). The Xe released from both samples at 950 deg C was terrestrial in isotopic composition, except for enrichments from spallogenic and radiogenic components (Figure 2). From the results of this and earlier analyses of Xe in meteoritic FeS [5, 6, 7], we conclude that terrestrial-type Xe was dominant in the central region of the protoplanetary nebula, and it remains a major component in the FeS of diverse meteorites and in the terrestrial planets that are rich in Fe, S [8]. References: [1] Begemann F. (1993) Origin and Evolution of the Elements (N. Prantzos et al., eds.), 518-527, Cambridge Univ. [2] Lewis R. S. and Anders E. (1988) LPS XIX, 679-680. [3] Burbidge et al. (1957) Rev. Modern Phys., 29, 547-650. [4] Tang M. and Anders E. (1988) GCA, 52, 1235-1244. [5] Niemeyer S. (1979) GCA, 43, 843-860. [6] Lewis et al. (1979) GCA, 43, 1743-1752. [7] Hwaung G. and Manuel O. K. (1982) Nature, 299

  8. Mantle derived economic sulfide mineralization?

    NASA Astrophysics Data System (ADS)

    Krivolutskaya, Nadezda; Gongalskiy, Bronislav; Svirskaya, Natalia

    2014-05-01

    Sulfide ores of the unique Pt-Cu-Ni Noril'sk deposits are characterized by heavy sulfur isotopic composition (d34S = 6-18 ‰ ; Grinenko, 1985). These data are traditionally explained by the crustal contamination of the mantle melts by Devonian sedimentary rocks with anhydrites at certain depths or in a chamber of crystallization (Naldrett, 1992; Li et al., 2009). However, data on the distribution of major and trace elements and isotopic composition (their eNd, 87Sr/86Sr, d34S) in the contact zones of the intrusions with the host rocks are at variance with any significant in-situ contamination. Moreover , the mechanism of the "digestion" of this high-temperature material (Tm = 1430ºC) by the lower temperature magma (1250ºC) has never been analyzed and questioned. Our pioneering data on the sulfur radiogenic isotopes in the anhydrite are in conflict with the hypothesis that this mineral could serve as a sulfur source for the Noril'sk ores. The fact that the average composition of the intrusions is independent on the stratigraphic setting of these intrusions, which can be hosted by limestone, sandstone, and/or basalt, provides further support for the idea that no assimilation took place at the depths of the chambers in which the melts crystallized.The reason for the heavy sulfur isotopic composition of ores in the Noril'sk district is still uncertain. Last data obtained on the sulfur isotopic composition of basalts and ores from some intrusions in the Taimyr Peninsula likely provide a clue to this problem. The highest d34S values in rocks of all of the trap formations were detected in the Gudchikhinsky picrites (d34S = +8,7; Ripley et al., 2003) formed from a primitive mantle magma. They are geochemically similar to the rocks from the Dyumtaleysky Massif (d34S = 12.2; Krivolutskaya and Gongalsky, 2013) which crystallized from a primitive mantle-derived magma (with no Ta-Nb and Pb anomalies and high Gd/Yb ratio) too. This intrusion comprises economic important

  9. Integration of Semiconducting Sulfides for Full-Spectrum Solar Energy Absorption and Efficient Charge Separation.

    PubMed

    Zhuang, Tao-Tao; Liu, Yan; Li, Yi; Zhao, Yuan; Wu, Liang; Jiang, Jun; Yu, Shu-Hong

    2016-05-23

    The full harvest of solar energy by semiconductors requires a material that simultaneously absorbs across the whole solar spectrum and collects photogenerated electrons and holes separately. The stepwise integration of three semiconducting sulfides, namely ZnS, CdS, and Cu2-x S, into a single nanocrystal, led to a unique ternary multi-node sheath ZnS-CdS-Cu2-x S heteronanorod for full-spectrum solar energy absorption. Localized surface plasmon resonance (LSPR) in the nonstoichiometric copper sulfide nanostructures enables effective NIR absorption. More significantly, the construction of pn heterojunctions between Cu2-x S and CdS leads to staggered gaps, as confirmed by first-principles simulations. This band alignment causes effective electron-hole separation in the ternary system and hence enables efficient solar energy conversion. PMID:27062543

  10. [Copper transport and metabolism].

    PubMed

    Kurasaki, Masaaki; Saito, Takeshi

    2016-07-01

    In this review, copper metabolism and transport in mammalian tissues are introduced and discussed. Firstly, the copper required amounts and LD50 levels are shown to explain the difficult balances of copper in the cells between necessity and toxicity. Furthermore, on the basis of literatures published, relationship between copper-binding metallothioneins and mechanisms for the absorption and excretion of copper or hereditary copper metabolic disorders metabolism abnormality symptom are explained. Finally it has been indicated that apoptosis induced by heavy metals, especially copper was initiated by production of reactive oxygen species and oxidative stress in the cells. To understand precise mechanism for copper homeostasis in mammalian cells, further investigation will be needed to clarify the copper behaviors in normal and abnormal situations. PMID:27455798

  11. Structural studies in limestone sulfidation

    SciTech Connect

    Fenouil, L.A.; Lynn, S.

    1993-05-01

    This study investigates the sulfidation of limestone at high temperatures (700--900{degree}C) as the first step in the design of a High-Temperature Coal-Gas Clean-Up system using millimeter-size limestone particles. Several workers have found that the rate of this reaction significantly decreases after an initial 10 to 15% conversion of CaCO{sub 3} to CaS. The present work attempts to explain this feature. It is first established that millimeter-size limestone particles do not sinter at temperatures up to the CaCO{sub 3} calcination point (899{degree}C at 1.03 bar CO{sub 2} partial pressure). It is then shown that CaS sinters rapidly at 750 to 900{degree}C if CO{sub 2} is present in the gas phase. Scanning Electron Microscope (SEM) photographs and Electron Dispersive Spectroscopy (EDS) data reveal that the CaS product layer sinters and forms a quasi-impermeable coating around the CaCO{sub 3} grains that greatly hinders more H{sub 2}S from reaching the still unreacted parts of the stone. Moreover, most of the pores initially present within the limestone structure begin to disappear or, at least, are significantly reduced in size. From then on, subsequent conversion is limited by diffusion of H{sub 2}S through the CaS layer, possibly by S{sup 2{minus}} ionic diffusion. The kinetics is then adequately described by a shrinking-core model, in which a sharp front of completely converted limestone is assumed to progress toward the center of the pellet. Finally, experimental evidence and computer simulations using simple sintering models suggest that the CaS sintering, responsible for the sharp decrease in the sulfidation rate, is surface-diffusion controlled.

  12. REMOVAL AND RECOVERY OF SULFIDE FROM TANNERY WASTEWATER

    EPA Science Inventory

    Recovery of sulfide from tannery waste was accomplished through acidification with sulfuric acid in a closed system and removing hydrogen sulfide formed by blowing with air. Sulfide was then absorbed in caustic solution to produce re-usable sodium sulfide/sulfhydrate liquor for t...

  13. Microbial control of hydrogen sulfide production

    SciTech Connect

    Montgomery, A.D.; Bhupathiraju, V.K.; Wofford, N.; McInerney, M.J.

    1995-12-31

    A sulfide-resistant strain of Thiobacillus denitrificans, strain F, prevented the accumulation of sulfide by Desulfovibrio desulfuricans when both organisms were grown in liquid medium. The wild-type strain of T. denitrificans did not prevent the accumulation of sulfide produced by D. desulfuricans. Strain F also prevented the accumulation of sulfide by a mixed population of sulfate-reducing bacteria enriched from an oil field brine. Fermentation balances showed that strain F stoichiometrically oxidized the sulfide produced by D. desulfuricans and the oil field brine enrichment to sulfate. The ability of a strain F to control sulfide production in an experimental system of cores and formation water from the Redfield, Iowa, natural gas storage facility was also investigated. A stable, sulfide-producing biofilm was established in two separate core systems, one of which was inoculated with strain F while the other core system (control) was treated in an identical manner, but was not inoculated with strain F. When formation water with 10 mM acetate and 5 mM nitrate was injected into both core systems, the effluent sulfide concentrations in the control core system ranged from 200 to 460 {mu}M. In the test core system inoculated with strain F, the effluent sulfide concentrations were lower, ranging from 70 to 110 {mu}M. In order to determine whether strain F could control sulfide production under optimal conditions for sulfate-reducing bacteria, the electron donor was changed to lactate and inorganic nutrients (nitrogen and phosphate sources) were added to the formation water. When nutrient-supplemented formation water with 3.1 mM lactate and 10 mM nitrate was used, the effluent sulfide concentrations of the control core system initially increased to about 3,800 {mu}M, and then decreased to about 1,100 {mu}M after 5 weeks. However, in the test core system inoculated with strain F, the effluent sulfide concentrations were much lower, 160 to 330 {mu}M.

  14. Nanostructured lead sulfide: synthesis, structure and properties

    NASA Astrophysics Data System (ADS)

    Sadovnikov, S. I.; Gusev, A. I.; Rempel, A. A.

    2016-07-01

    The theoretical and experimental results of recent studies dealing with nanostructured lead sulfide are summarized and analyzed. The key methods for the synthesis of nanostructured lead sulfide are described. The crystal structure of PbS in nanopowders and nanofilms is discussed. The influence of the size of nanostructure elements on the optical and thermal properties of lead sulfide is considered. The dependence of the band gap of PbS on the nanoparticle (crystallite) size for powders and films is illustrated. The bibliography includes 222 references.

  15. Using XAS and SXRF to Study Copper in Wilson Disease at the Molecular and Tissue Level

    SciTech Connect

    Ralle, Martina; Lutsenko, Svetlana; Blackburn, Ninian J.

    2007-02-02

    Wilson disease (WD) is a genetic disorder of copper metabolism associated with severe hepatic, neurological, and psychiatric abnormalities. In WD, the billiary copper excretion is impaired and copper accumulates in tissues, particularly in the liver and the brain. The affected gene, ATP7B, encodes the copper transporting ATPase, Wilson disease protein (WNDP). WNDP has six copper binding sites in the N-terminal portion of the molecule. Each site includes the conserved amino acid sequence MXCXXC, and binds 1 Cu(I) through its 2 cysteine residues. We performed X-ray absorption studies at the Cu K{alpha}-edge on the recombinant N-terminal domain of WNDP (N-WNDP). Copper was bound to N-WNDP either in vivo or in vitro in the presence of different reducing agents. We found that in N-WNDP copper is predominantly coordinated in a linear fashion by two cysteines, with the appearance of a Cu-Cu interaction when all metal binding sites are filled. Increasing amounts of reducing agents containing sulfide or phosphine groups led to binding of the exogenous ligands to copper thereby increasing the coordination number of copper from two to three. To better understand the role of copper in WD, we utilized livers of the 6-weeks-old Atp7b-/- mice (an animal model for WD) in which the copper concentration was 10-20-fold higher compared to that of the control mice. The distribution of copper in hepatocytes was evaluated by synchrotron based X-ray fluorescence microprobe (SXRF). We demonstrate that we can prepare liver slices that retain copper and can detect copper with subcellular resolution. On the same sections {mu}-XANES (spot size: 5 micron) was used to determine the oxidation state of copper.

  16. Using Xas And Sxrf to Study Copper in Wilson Disease at the Molecular And Tissue Level

    SciTech Connect

    Ralle, M.; Blackburn, N.J.; Lutsenko, S.

    2009-06-05

    Wilson disease (WD) is a genetic disorder of copper metabolism associated with severe hepatic, neurological, and psychiatric abnormalities. In WD, the billiary copper excretion is impaired and copper accumulates in tissues, particularly in the liver and the brain. The affected gene, ATP7B, encodes the copper transporting ATPase, Wilson disease protein (WNDP). WNDP has six copper binding sites in the N-terminal portion of the molecule. Each site includes the conserved amino acid sequence MXCXXC, and binds 1 Cu(I) through its 2 cysteine residues. We performed X-ray absorption studies at the Cu K{sub {alpha}}-edge on the recombinant N-terminal domain of WNDP (N-WNDP). Copper was bound to N-WNDP either in vivo or in vitro in the presence of different reducing agents. We found that in N-WNDP copper is predominantly coordinated in a linear fashion by two cysteines, with the appearance of a Cu-Cu interaction when all metal binding sites are filled. Increasing amounts of reducing agents containing sulfide or phosphine groups led to binding of the exogenous ligands to copper thereby increasing the coordination number of copper from two to three. To better understand the role of copper in WD, we utilized livers of the 6-weeks-old Atp7b-/- mice (an animal model for WD) in which the copper concentration was 10--20-fold higher compared to that of the control mice. The distribution of copper in hepatocytes was evaluated by synchrotron based X-ray fluorescence microprobe (SXRF). We demonstrate that we can prepare liver slices that retain copper and can detect copper with subcellular resolution. On the same sections {mu}-XANES (spot size: 5 micron) was used to determine the oxidation state of copper.

  17. Using XAS and SXRF to Study Copper in Wilson Disease at the Molecular and Tissue Level

    NASA Astrophysics Data System (ADS)

    Ralle, Martina; Blackburn, Ninian J.; Lutsenko, Svetlana

    2007-02-01

    Wilson disease (WD) is a genetic disorder of copper metabolism associated with severe hepatic, neurological, and psychiatric abnormalities. In WD, the billiary copper excretion is impaired and copper accumulates in tissues, particularly in the liver and the brain. The affected gene, ATP7B, encodes the copper transporting ATPase, Wilson disease protein (WNDP). WNDP has six copper binding sites in the N-terminal portion of the molecule. Each site includes the conserved amino acid sequence MXCXXC, and binds 1 Cu(I) through its 2 cysteine residues. We performed X-ray absorption studies at the Cu Kα-edge on the recombinant N-terminal domain of WNDP (N-WNDP). Copper was bound to N-WNDP either in vivo or in vitro in the presence of different reducing agents. We found that in N-WNDP copper is predominantly coordinated in a linear fashion by two cysteines, with the appearance of a Cu-Cu interaction when all metal binding sites are filled. Increasing amounts of reducing agents containing sulfide or phosphine groups led to binding of the exogenous ligands to copper thereby increasing the coordination number of copper from two to three. To better understand the role of copper in WD, we utilized livers of the 6-weeks-old Atp7b-/- mice (an animal model for WD) in which the copper concentration was 10-20-fold higher compared to that of the control mice. The distribution of copper in hepatocytes was evaluated by synchrotron based X-ray fluorescence microprobe (SXRF). We demonstrate that we can prepare liver slices that retain copper and can detect copper with subcellular resolution. On the same sections μ-XANES (spot size: 5 micron) was used to determine the oxidation state of copper.

  18. Removal of methanethiol, dimethyl sulfide, dimethyl disulfide, and hydrogen sulfide from contaminated air by Thiobacillus thioparus TK-m

    SciTech Connect

    Kanagawa, T.; Mikami, E.

    1989-03-01

    Methanethiol, dimethyl sulfide, dimethyl disulfide, and hydrogen sulfide were efficiently removed from contaminated air by Thiobacillus thioparus TK-m and oxidized to sulfate stoichiometrically. More than 99.99% of dimethyl sulfide was removed when the load was less than 4.0 g of dimethyl sulfide per g (dry cell weight) per day.

  19. Ridding Groundwater of Hydrogen Sulfide. Part 1.

    ERIC Educational Resources Information Center

    Lochrane, Thomas G.

    1979-01-01

    This article is the first in a series reviewing the problems associated with hydrogen sulfide in drinking water sources. Discussion centers on identification of a cost-effective balance between aeration and chlorination treatment operations. (AS)

  20. Photooxidation of methyl sulfide, ethyl sulfide, and methanethiol

    SciTech Connect

    Grosjean, D.

    1984-06-01

    Products of sunlight-irradiated mixtures of oxides of nitrogen and alkyl sulfides (RSR, R = CH/sub 3/, C/sub 2/H/sub 5/) and methanethiol (CH/sub 3/SH) in air include formaldehyde (R = CH/sub 3/), acetaldehyde and PAN (R = C/sub 2/H/sub 5/), sulfur dioxide, and alkyl nitrates (RONO/sub 2/) as well as particulate alkanesulfonic acids (RSO/sub 2/OH) and inorganic sulfate. The nature and yields of gaseous and particulate products are discussed in terms of OH-initiated reaction pathways, including C-S bond scission, and subsequent reactions of alkythiyl radicals (RS), including those leading to photolabile RSNO and stable RSNO/sub 2/ products for which indirect evidence is presented. SO/sub 2/ yields are found to vary according to the relative importance of the competing pathways RS + O/sub 2/ (a) and RS + NO/sub 2/ (b), for which a ratio k/sub b/ / k/sub a/ approx. 2 x 10/sup 6/ is derived from data for irradiated RSR-NO/sub x/, RSH-Cl/sub 2/, and RSH-Cl/sub 2/-NO/sub 2/ mixtures.

  1. Effect of Nitrate on Biogenic Sulfide Production

    PubMed Central

    Jenneman, Gary E.; McInerney, M. J.; Knapp, Roy M.

    1986-01-01

    The addition of 59 mM nitrate inhibited biogenic sulfide production in dilute sewage sludge (10% [vol/vol]) amended with 20 mM sulfate and either acetate, glucose, or hydrogen as electron donors. Similar results were found when pond sediment or oil field brines served as the inoculum. Sulfide production was inhibited for periods of at least 6 months and was accompanied by the oxidation of resazurin from its colorless reduced state to its pink oxidized state. Lower amounts of nitrate (6 or 20 mM) and increased amounts of sewage sludge resulted in only transient inhibition of sulfide production. The addition of 156 mM sulfate to bottles with 59 mM nitrate and 10% (vol/vol) sewage sludge or pond sediment resulted in sulfide production. Nitrate, nitrite, and nitrous oxide were detected during periods where sulfide production was inhibited, whereas nitrate, nitrite, and nitrous oxide were below detectable levels at the time sulfide production began. The oxidation of resazurin was attributed to an increase in nitrous oxide which persisted in concentration of about 1.0 mM for up to 5 months. The numbers of sulfate-reducing organisms decreased from 106 CFU ml−1 sludge to less than detectable levels after prolonged incubation of oxidized bottles. The addition of 10 mM glucose to oxidized bottles after 14.5 weeks of incubation resulted in rereduction of the resazurin and subsequent sulfide production. The prolonged inhibition of sulfide production was attributed to an increase in oxidation-reduction potential due to biogenic production of nitrous oxide, which appeared to have a cytotoxic effect on sulfate-reducing populations. PMID:16347078

  2. The Search for Interstellar Sulfide Grains

    NASA Technical Reports Server (NTRS)

    Keller, Lindsay P.; Messenger, Scott

    2010-01-01

    The lifecycle of sulfur in the galaxy is poorly understood. Fe-sulfide grains are abundant in early solar system materials (e.g. meteorites and comets) and S is highly depleted from the gas phase in cold, dense molecular cloud environments. In stark contrast, sulfur is essentially undepleted from the gas phase in the diffuse interstellar medium, indicating that little sulfur is incorporated into solid grains in this environment. It is widely believed that sulfur is not a component of interstellar dust grains. This is a rather puzzling observation unless Fe-sulfides are not produced in significant quantities in stellar outflows, or their lifetime in the ISM is very short due to rapid destruction. Fe sulfide grains are ubiquitous in cometary samples where they are the dominant host of sulfur. The Fe-sulfides (primarily pyrrhotite; Fe(1-x)S) are common, both as discrete 0.5-10 micron-sized grains and as fine (5-10 nm) nanophase inclusions within amorphous silicate grains. Cometary dust particles contain high abundances of well-preserved presolar silicates and organic matter and we have suggested that they should contain presolar sulfides as well. This hypothesis is supported by the observation of abundant Fe-sulfides grains in dust around pre- and post-main sequence stars inferred from astronomical spectra showing a broad 23 micron IR feature due to FeS. Fe-sulfide grains also occur as inclusions in bona fide circumstellar amorphous silicate grains and as inclusions within deuterium-rich organic matter in cometary dust samples. Our irradiation experiments show that FeS is far more resistant to radiation damage than silicates. Consequently, we expect that Fe sulfide stardust should be as abundant as silicate stardust in solar system materials.

  3. Catalytic dehydroxylation of phenols. [Metal sulfides

    SciTech Connect

    Pieters, W.J.M.

    1984-05-29

    Phenolic compounds are dehydroxylated in the vapor phase by contacting with a reducing atmosphere substantially comprising hydrogen sulfide as the reducing agent in the presence of a sulfur-tolerant metal sulfide catalyst. The additional presence of hydrogen gas helps to desulfurize the catalyst and maintain catalytic activity. The process is useful in the treatment of phenolic naphtha fractions present in coal liquids, produced by pyrolysis or direct coal liquefaction.

  4. Copper in diet

    MedlinePlus

    ... please enable JavaScript. Copper is an essential trace mineral present in all body tissues. Function Copper works ... nih.gov/pubmed/25057538 . Mason JB. Vitamins, trace minerals, and other micronutrients. In: Goldman L, Schafer AI, ...

  5. Sulfides from Martian and Lunar Basalts: Comparative Chemistry for Ni Co Cu and Se

    SciTech Connect

    J Papike; P Burger; C Shearer; S Sutton; M Newville; Y Choi; A Lanzirotti

    2011-12-31

    Here Mars and Moon are used as 'natural laboratories' with Moon displaying lower oxygen fugacities ({approx}IW-1) than Mars ({approx}IW to FMQ). Moon has lower concentrations of Ni and Co in basaltic melts than does Mars. The major sulfides are troilite (FeS) in lunar basalts and pyrrhotite (Fe{sub 1-x}S) in martian basalts. This study focuses on the concentrations of Ni, Co, Cu, and Se. We chose these elements because of their geochemical importance and the feasibility of analyzing them with a combination of synchrotron X-ray fluorescence (SXRF) and electron microprobe (EPMA) techniques. The selenium concentrations could only be analyzed, at high precision, with SXRF techniques as they are <150 ppm, similar to concentrations seen in carbonaceous chondrites and interplanetary dust particles (IDPs). Nickel and Co are in higher concentrations in martian sulfides than lunar and are higher in martian olivine-bearing lithologies than olivine-free varieties. The sulfides in individual samples show very large ranges in concentration (e.g., Ni ranges from 50 000 ppm to <5 ppm). These large ranges are mainly due to compositional heterogeneities within individual grains due to diffusion and phase separation. Electron microprobe wavelength-dispersive (WDS) mapping of Ni, Co, and Cu show the diffusion trajectories. Nickel and Co have almost identical diffusion trajectories leading to the likely nucleation of pentlandite (Ni,Co,Fe){sub 9}S{sub 8}, and copper diffuses along separate pathways likely toward chalcopyrite nucleation sites (CuFeS{sub 2}). The systematics of Ni and Co in lunar and martian sulfides clearly distinguish the two parent bodies, with martian sulfides displaced to higher Ni and Co values.

  6. Copper-tantalum alloy

    DOEpatents

    Schmidt, Frederick A.; Verhoeven, John D.; Gibson, Edwin D.

    1986-07-15

    A tantalum-copper alloy can be made by preparing a consumable electrode consisting of an elongated copper billet containing at least two spaced apart tantalum rods extending longitudinally the length of the billet. The electrode is placed in a dc arc furnace and melted under conditions which co-melt the copper and tantalum to form the alloy.

  7. Demystifying Controlling Copper Corrosion

    EPA Science Inventory

    The LCR systematically misses the highest health and corrosion risk sites for copper. Additionally, there are growing concerns for WWTP copper in sludges and discharge levels. There are many corrosion control differences between copper and lead. This talk explains the sometimes c...

  8. On copper peroxide

    NASA Technical Reports Server (NTRS)

    Moser, L.

    1988-01-01

    The action of hydrogen superoxide on copper salts in alcoholic solutions is studied. The action of hydrogen peroxide on copper hydroxide in alcoholic suspensions, and the action of ethereal hydrogen peroxide on copper hydroxide are discussed. It is concluded that using the procedure proposed excludes almost entirely the harmful effect of hydrolysis.

  9. Hydrogen Sulfide as a Gasotransmitter

    PubMed Central

    Gadalla, Moataz M.; Snyder, Solomon H.

    2010-01-01

    Nitric oxide (NO) and carbon monoxide (CO) are well established as messenger molecules throughout the body, gasotransmitters, based on striking alterations in mice lacking the appropriate biosynthetic enzymes. Hydrogen sulfide (H2S) is even more chemically reactive, but till recently there was little definitive evidence for its physiologic formation. Cystathionine β-synthase (CBS, EC 4.2.1.22), and Cystathionine γ-lyase (CSE; EC 4.4.1.1), also known as cytathionase, can generate H2S from cyst(e)ine. Very recent studies with mice lacking these enzymes have established that CSE is responsible for H2S formation in the periphery, while in the brain CBS is the biosynthetic enzyme. Endothelial-derived relaxing factor (EDRF) activity is reduced 80% in the mesenteric artery of mice with deletion of CSE, establishing H2S as a major physiologic EDRF. H2S appears to signal predominantly by S-sulfhydrating cysteines in its target proteins, analogous to S-nitrosylation by NO. Whereas S-nitrosylation typically inhibits enzymes, S-sulfhydration activates them. S-nitrosylation basally affects 1–2% of its target proteins, while 10–25% of H2S target proteins are S-sulfhydrated. In summary, H2S appears to be a physiologic gasotransmitter of comparable importance to NO and CO. PMID:20067586

  10. Hydrogen sulfide and translational medicine

    PubMed Central

    Guo, Wei; Cheng, Ze-yu; Zhu, Yi-zhun

    2013-01-01

    Hydrogen sulfide (H2S) along with carbon monoxide and nitric oxide is an important signaling molecule that has undergone large numbers of fundamental investigations. H2S is involved in various physiological activities associated with the regulation of homeostasis, vascular contractility, pro- and anti-inflammatory activities, as well as pro- and anti-apoptotic activities etc. However, the actions of H2S are influenced by its concentration, reaction time, and cell/disease types. Therefore, H2S is a signaling molecule without definite effect. The use of existing H2S donors is limited because of the instant release and short lifetime of H2S. Thus, translational medicine involving the sustained and controlled release of H2S is of great value for both scientific and clinical uses. H2S donation can be manipulated by different ways, including where H2S is given, how H2S is donated, or the specific structures of H2S-releasing drugs and H2S donor molecules. This review briefly summarizes recent progress in research on the physiological and pathological functions of H2S and H2S-releasing drugs, and suggests hope for future investigations. PMID:24096643

  11. Sulfide response analysis for sulfide control using a pS electrode in sulfate reducing bioreactors.

    PubMed

    Villa-Gomez, D K; Cassidy, J; Keesman, K J; Sampaio, R; Lens, P N L

    2014-03-01

    Step changes in the organic loading rate (OLR) through variations in the influent chemical oxygen demand (CODin) concentration or in the hydraulic retention time (HRT) at constant COD/SO4(2-) ratio (0.67) were applied to create sulfide responses for the design of a sulfide control in sulfate reducing bioreactors. The sulfide was measured using a sulfide ion selective electrode (pS) and the values obtained were used to calculate proportional-integral-derivative (PID) controller parameters. The experiments were performed in an inverse fluidized bed bioreactor with automated operation using the LabVIEW software version 2009(®). A rapid response and high sulfide increment was obtained through a stepwise increase in the CODin concentration, while a stepwise decrease to the HRT exhibited a slower response with smaller sulfide increment. Irrespective of the way the OLR was decreased, the pS response showed a time-varying behavior due to sulfide accumulation (HRT change) or utilization of substrate sources that were not accounted for (CODin change). The pS electrode response, however, showed to be informative for applications in sulfate reducing bioreactors. Nevertheless, the recorded pS values need to be corrected for pH variations and high sulfide concentrations (>200 mg/L). PMID:24361702

  12. NEAR-CONTINUOUS MEASUREMENT OF HYDROGEN SULFIDE AND CARBONYL SULFIDE BY AN AUTOMATIC GAS CHROMATOGRAPH

    EPA Science Inventory

    An automatic gas chromatograph with a flame photometric detector that samples and analyzes hydrogen sulfide and carbonyl sulfide at 30-s intervals is described. Temperature programming was used to elute trace amounts of carbon disulfide present in each injection from a Supelpak-S...

  13. Continuous measurement of dissolved sulfide in sewer systems.

    PubMed

    Sutherland-Stacey, L; Corrie, S; Neethling, A; Johnson, I; Gutierrez, O; Dexter, R; Yuan, Z; Keller, J; Hamilton, G

    2008-01-01

    Sulfides are particularly problematic in the sewage industry. Hydrogen sulfide causes corrosion of concrete infrastructure, is dangerous at high concentrations and is foul smelling at low concentrations. Despite the importance of sulfide monitoring there is no commercially available system to quantify sulfide in waste water. In this article we report on our use of an in situ spectrometer to quantify bisulfide in waste water and additional analysis with a pH probe to calculate total dissolved sulfide. Our results show it is possible to use existing commercially available and field proven sensors to measure sulfide to mg/l levels continuously with little operator intervention and no sample preparation. PMID:18309215

  14. Process for producing cadmium sulfide on a cadmium telluride surface

    DOEpatents

    Levi, Dean H.; Nelson, Art J.; Ahrenkiel, Richard K.

    1996-01-01

    A process for producing a layer of cadmium sulfide on a cadmium telluride surface to be employed in a photovoltaic device. The process comprises providing a cadmium telluride surface which is exposed to a hydrogen sulfide plasma at an exposure flow rate, an exposure time and an exposure temperature sufficient to permit reaction between the hydrogen sulfide and cadmium telluride to thereby form a cadmium sulfide layer on the cadmium telluride surface and accomplish passivation. In addition to passivation, a heterojunction at the interface of the cadmium sulfide and the cadmium telluride can be formed when the layer of cadmium sulfide formed on the cadmium telluride is of sufficient thickness.

  15. Animal adaptations for tolerance and exploitation of poisonous sulfide.

    PubMed

    Grieshaber, M K; Völkel, S

    1998-01-01

    Many aquatic animal species can survive sulfide exposure to some extent through oxidation of the sulfide, which results mainly in thiosulfate. In several species, sulfide oxidation is localized in the mitochondria and is accompanied by ATP synthesis. In addition, blood-based and intracellular compounds can augment sulfide oxidation. The formation of thiosulfate requires oxygen, which results in an increase in oxygen consumption of some species. If not all sulfide is detoxified, cytochrome C oxidase is inhibited. Under these conditions, a sulfide-dependent anaerobic energy metabolism commences. PMID:9558453

  16. Hydrogen Sulfide Inhibits Amyloid Formation

    PubMed Central

    2015-01-01

    Amyloid fibrils are large aggregates of misfolded proteins, which are often associated with various neurodegenerative diseases such as Alzheimer’s, Parkinson’s, Huntington’s, and vascular dementia. The amount of hydrogen sulfide (H2S) is known to be significantly reduced in the brain tissue of people diagnosed with Alzheimer’s disease relative to that of healthy individuals. These findings prompted us to investigate the effects of H2S on the formation of amyloids in vitro using a model fibrillogenic protein hen egg white lysozyme (HEWL). HEWL forms typical β-sheet rich fibrils during the course of 70 min at low pH and high temperatures. The addition of H2S completely inhibits the formation of β-sheet and amyloid fibrils, as revealed by deep UV resonance Raman (DUVRR) spectroscopy and ThT fluorescence. Nonresonance Raman spectroscopy shows that disulfide bonds undergo significant rearrangements in the presence of H2S. Raman bands corresponding to disulfide (RSSR) vibrational modes in the 550–500 cm–1 spectral range decrease in intensity and are accompanied by the appearance of a new 490 cm–1 band assigned to the trisulfide group (RSSSR) based on the comparison with model compounds. The formation of RSSSR was proven further using a reaction with TCEP reduction agent and LC-MS analysis of the products. Intrinsic tryptophan fluorescence study shows a strong denaturation of HEWL containing trisulfide bonds. The presented evidence indicates that H2S causes the formation of trisulfide bridges, which destabilizes HEWL structure, preventing protein fibrillation. As a result, small spherical aggregates of unordered protein form, which exhibit no cytotoxicity by contrast with HEWL fibrils. PMID:25545790

  17. Stratospheric carbonyl sulfide (OCS) burden

    NASA Astrophysics Data System (ADS)

    Kloss, Corinna; Walker, Kaley A.; Deshler, Terry; von Hobe, Marc

    2015-04-01

    An estimation of the global stratospheric burden of carbonyl sulfide (OCS) calculated using satellite based measurements from the Atmospheric Chemistry Experiment - Fourier Transform Spectrometer (ACE-FTS) will be presented. OCS is the most abundant sulfur containing gas in the atmosphere in the absence of volcanic eruptions. With a long lifetime of 2-6 years it reaches the stratosphere where it is photolyzed and the sulfur oxidized and condensed to aerosols, contributing to the stratospheric aerosol layer. The aerosol layer is the one factor of the middle-atmosphere with a direct impact on the Earth's climate by scattering incoming solar radiation back to space. Therefore it is crucial to understand and estimate the different processes and abundances of the species contributing to the aerosol layer. However, the exact amount of OCS in the stratosphere has not been quantified yet. A study on the OCS mixing ratio distribution based on ACE-FTS data has already been made by Barkley et al. (2008), also giving an estimation for the total atmospheric OCS mass. ACE-FTS is an infrared solar occultation spectrometer providing high- resolution profile observations since 2004. In the scope of this work the focus lies on the stratospheric OCS burden, calculated by integrating the ACE profiles. A global overview on the stratospheric OCS amount in the past and present based on the ACE data as well as a look at regional and seasonal variability will be given. Furthermore, the results of this work will be useful for further studies on OCS fluxes and lifetimes, and in quantifying the contribution of OCS to the global stratospheric sulfur burden. Barkley et al., 2008, Geophys. Res. Lett., 35, L14810.

  18. Phase Engineering of 2D Tin Sulfides.

    PubMed

    Mutlu, Zafer; Wu, Ryan J; Wickramaratne, Darshana; Shahrezaei, Sina; Liu, Chueh; Temiz, Selcuk; Patalano, Andrew; Ozkan, Mihrimah; Lake, Roger K; Mkhoyan, K A; Ozkan, Cengiz S

    2016-06-01

    Tin sulfides can exist in a variety of phases and polytypes due to the different oxidation states of Sn. A subset of these phases and polytypes take the form of layered 2D structures that give rise to a wide host of electronic and optical properties. Hence, achieving control over the phase, polytype, and thickness of tin sulfides is necessary to utilize this wide range of properties exhibited by the compound. This study reports on phase-selective growth of both hexagonal tin (IV) sulfide SnS2 and orthorhombic tin (II) sulfide SnS crystals with diameters of over tens of microns on SiO2 substrates through atmospheric pressure vapor-phase method in a conventional horizontal quartz tube furnace with SnO2 and S powders as the source materials. Detailed characterization of each phase of tin sulfide crystals is performed using various microscopy and spectroscopy methods, and the results are corroborated by ab initio density functional theory calculations. PMID:27099950

  19. USING RESPOROMETRY TO MEASURE HYDROGEN UTILIZATION IN SULFATE REDUCING BACTERIA IN THE PRESENCE OF COPPER AND ZINC

    EPA Science Inventory

    A proposed novel method for treatment of acid mine drainage (AMD) waste uses biologically-generated hydrogen sulfide to precipitate the metals in AMD (principally zinc, iron, aluminum, copper and manganese in the Berkeley Pit). The solids are sequentially removed via settling. ...

  20. Separation of dialkyl sulfides by metallo-mesogenic stationary phases for complexation gas chromatography.

    PubMed

    Chen, Jian-Lian; Liu, Chuen-Ying

    2007-08-17

    A copper mesogenic side-chain polymer (P-C(15)CuC(18)) was cross-linked onto the capillary wall as a stationary film for gas chromatography (GC) separation of alkyl sulfides. These organic sulfides are of interest for their large health impact because of their wide range of volatiles and high reactivities toward metals. Different GC parameters for optimal separation efficiency are discussed for use with a mesogenic polymer column along with flame photometric detection (FPD). Both the carrier gas flow-rate and column temperature were studied to determine the relationship of plate height to the chemical structure of the solutes, as well as to determine the morphology of the mesogenic polymer. Van 't Hoff plots show phase transitions of the stationary mesophase as the column temperature was varied. The results reveal that the separation mechanism might be based on ligand exchange and polarity interaction between the analytes and the stationary phase, with the vapor pressure of the analytes also being important. The former interaction dominates in the lamellar crystalline phase and the latter interaction dominates in the hexagonal columnar-discotic phase. With high reproducibility for retention time (RSD< or =0.37%) and for peak area (RSD< or =5.16%), the GC-FPD system produced linear calibration graphs (r> or =0.9918) for the determination of 13 sulfides with a detection limit below 2.5 ng. PMID:17568598

  1. State-of-the-art hydrogen sulfide control for geothermal energy systems: 1979

    SciTech Connect

    Stephens, F.B.; Hill, J.H.; Phelps, P.L. Jr.

    1980-03-01

    Existing state-of-the-art technologies for removal of hydrogen sulfide are discussed along with a comparative assessment of their efficiencies, reliabilities and costs. Other related topics include the characteristics of vapor-dominated and liquid-dominated resources, energy conversion systems, and the sources of hydrogen sulfide emissions. It is indicated that upstream control technologies are preferred over downsteam technologies primarily because upstream removal of hydrogen sulfide inherently controls all downstream emissions including steam-stacking. Two upstream processes for vapor-dominated resources appear promising; the copper sulfate (EIC) process, and the steam converter (Coury) process combined with an off-gas abatement system such as a Stretford unit. For liquid-dominated systems that produce steam, the process where the non-condensible gases are scrubbed with spent geothermal fluid appears to be promising. An efficient downstream technology is the Stretford process for non-condensible gas removal. In this case, partitioning in the surface condenser will determine the overall abatement efficiency. Recommendations for future environmental control technology programs are included.

  2. Reduction of acid rock drainage using steel slag in cover systems over sulfide rock waste piles.

    PubMed

    de Almeida, Rodrigo Pereira; Leite, Adilson do Lago; Borghetti Soares, Anderson

    2015-04-01

    The extraction of gold, coal, nickel, uranium, copper and other earth-moving activities almost always leads to environmental damage. In metal and coal extraction, exposure of sulfide minerals to the atmosphere leads to generation of acid rock drainage (ARD) and in underground mining to acid mine drainage (AMD) due to contamination of infiltrating groundwater. This study proposes to develop a reactive cover system that inhibits infiltration of oxygen and also releases alkalinity to increase the pH of generated ARD and attenuate metal contaminants at the same time. The reactive cover system is constructed using steel slag, a waste product generated from steel industries. This study shows that this type of cover system has the potential to reduce some of the adverse effects of sulfide mine waste disposal on land. Geochemical and geotechnical characterization tests were carried out. Different proportions of sulfide mine waste and steel slag were studied in leachate extraction tests. The best proportion was 33% of steel slag in dry weight. Other tests were conducted as follows: soil consolidation, saturated permeability and soil water characteristic curve. The cover system was numerically modeled through unsaturated flux analysis using Vadose/w. The solution proposed is an oxygen transport barrier that allows rain water percolation to treat the ARD in the waste rock pile. The results showed that the waste pile slope is an important factor and the cover system must have 5 m thickness to achieve an acceptable effectiveness. PMID:25750056

  3. Mortality among sulfide ore miners

    SciTech Connect

    Ahlman, K.; Koskela, R.S.; Kuikka, P.; Koponen, M.; Annanmaeki, M. )

    1991-01-01

    Lung cancer mortality was studied during 1965-1985 in Outokumpu township in North Karelia, where an old copper mine was located. Age-specific lung cancer death rates (1968-1985) were higher among the male population of Outokumpu than among the North Karelian male population of the same age excluding the Outokumpu district (p less than .01). Of all 106 persons who died from lung cancer during 1965-1985 in Outokumpu township, 47 were miners of the old mine, 39 of whom had worked there for at least three years and been heavily exposed to radon daughters and silica dust. The study cohort consisted of 597 miners first employed between 1954 and 1973 by a new copper mine and a zinc mine, and employed there for at least 3 years. The period of follow-up was 1954-1986. The number of person-years was 14,782. The total number of deaths was 102; the expected number was 72.8 based on the general male population and 97.8 based on the mortality of the male population of North Karelia. The excess mortality among miners was due mainly to ischemic heart disease (IHD); 44 were observed, the expected number was 22.1, based on the general male population, and the North Karelian expected number was 31.2 (p less than .05). Of the 44 miners who died from IHD, 20 were drillers or chargers exposed to nitroglycerin in dynamite charges, but also to several simultaneous stress factors including PAHs, noise, vibration, heavy work, accident risk, and working alone. Altogether 16 tumors were observed in the cohort. Ten of these were lung cancers, the expected number being 4.3. Miners who had died from lung cancer were 35-64 years old, and had entered mining work between 1954 and 1960. Five of the ten lung cancer cases came from the zinc mine (1.7 expected). Three of them were conductors of diesel-powered ore trains.

  4. Uniform yolk-shell iron sulfide-carbon nanospheres for superior sodium-iron sulfide batteries.

    PubMed

    Wang, Yun-Xiao; Yang, Jianping; Chou, Shu-Lei; Liu, Hua Kun; Zhang, Wei-Xian; Zhao, Dongyuan; Dou, Shi Xue

    2015-01-01

    Sodium-metal sulfide battery holds great promise for sustainable and cost-effective applications. Nevertheless, achieving high capacity and cycling stability remains a great challenge. Here, uniform yolk-shell iron sulfide-carbon nanospheres have been synthesized as cathode materials for the emerging sodium sulfide battery to achieve remarkable capacity of ∼ 545 mA h g(-1) over 100 cycles at 0.2 C (100 mA g(-1)), delivering ultrahigh energy density of ∼ 438 Wh kg(-1). The proven conversion reaction between sodium and iron sulfide results in high capacity but severe volume changes. Nanostructural design, including of nanosized iron sulfide yolks (∼ 170 nm) with porous carbon shells (∼ 30 nm) and extra void space (∼ 20 nm) in between, has been used to achieve excellent cycling performance without sacrificing capacity. This sustainable sodium-iron sulfide battery is a promising candidate for stationary energy storage. Furthermore, this spatially confined sulfuration strategy offers a general method for other yolk-shell metal sulfide-carbon composites. PMID:26507613

  5. Uniform yolk-shell iron sulfide-carbon nanospheres for superior sodium-iron sulfide batteries

    NASA Astrophysics Data System (ADS)

    Wang, Yun-Xiao; Yang, Jianping; Chou, Shu-Lei; Liu, Hua Kun; Zhang, Wei-Xian; Zhao, Dongyuan; Dou, Shi Xue

    2015-10-01

    Sodium-metal sulfide battery holds great promise for sustainable and cost-effective applications. Nevertheless, achieving high capacity and cycling stability remains a great challenge. Here, uniform yolk-shell iron sulfide-carbon nanospheres have been synthesized as cathode materials for the emerging sodium sulfide battery to achieve remarkable capacity of ~545 mA h g-1 over 100 cycles at 0.2 C (100 mA g-1), delivering ultrahigh energy density of ~438 Wh kg-1. The proven conversion reaction between sodium and iron sulfide results in high capacity but severe volume changes. Nanostructural design, including of nanosized iron sulfide yolks (~170 nm) with porous carbon shells (~30 nm) and extra void space (~20 nm) in between, has been used to achieve excellent cycling performance without sacrificing capacity. This sustainable sodium-iron sulfide battery is a promising candidate for stationary energy storage. Furthermore, this spatially confined sulfuration strategy offers a general method for other yolk-shell metal sulfide-carbon composites.

  6. Labile sulfide and sulfite in phytochelatin complexes

    SciTech Connect

    Eannetta, N.T.; Steffens, J.C. )

    1989-04-01

    Heavy metals such as cadmium induce tomato cell cultures to synthesize the metal binding polypeptides ({gamma}-Glu-Cys){sub 3} and ({gamma}-Glu-Cys){sub 4}-Gly (phytochelatins). Tomato cells selected for growth on normally lethal concentrations of CdCl{sub 2} synthesize higher quantities of these polypeptides. Cd{sup r} cells are not cross-resistant to other heavy metals, and recent work suggests that metal detoxification by these peptides may be Cd-specific. The occurrence of labile sulfur as a component of the metal complex raises questions concerning possible functions of phytochelatins besides that of Cd binding. The presence of acid-labile sulfide ion in phytochelatin complexes has been reported by several groups. We report the additional finding that labile sulfite is also present in these complexes and in higher amounts than sulfide. Sulfide and sulfite are both released from the metal binding complex by acidification or by treatment with EDTA.

  7. The arsenic removal from arsenopyrite in sulfide mineral by physicochemical extraction

    NASA Astrophysics Data System (ADS)

    Jo, Jiyu; Cho, Kanghee; Choi, Nagchoul; Park*, Cheonyoung

    2015-04-01

    The most abundant As ore mineral is arsenopyrite (FeAsS). Arsenopyrite is present in sulfide ores associated with sediment-hosted Au deposits, it tends to be the earliest-formed mineral, derived from hydrothermal solutions and formed at temperatures typically of 100(degree Celsius) or more. The aim of this study was to investigate the mineralogical phase change and arsenic removal from arsenopyrite as a penalty element in sulfide mineral contained Au by physical extraction (high frequency) and chemical leaching (thiocyanate). Arsenic removal experiments for were performed under various conditions of high frequency exposure(1~35 min), thiocyanate concentration (0.1~1.0M), HCl concentration (0.1~2.0M), copper(2) sulfate concentration (0.1~1.0M), temperature (30~60 degree Celsius). Increasing the high frequency exposure produced a positive effect on arsenic removal in arsenopyrite. The highest percentage arsenic removal of 96.67% was obtained under the following conditions by thiocyanate leaching: thiocyanate concentration = 1.0M ; HCl concentration = 2.0M ; copper(2) sulfate concentration = 1.0M ; temperature = 60(degree Celsius) This study demonstrates the adequate performance of physical extraction (high frequency) and chemical leaching (thiocyanate) for the arsenic removal from arsenopyrite as a penalty element.

  8. Critical currents in sputtered copper molybdenum sulphide

    NASA Technical Reports Server (NTRS)

    Alterovitz, S. A.; Woollam, J. A.; Kammerdiner, L.; Luo, H.-L.

    1977-01-01

    Critical currents in a sputtered Chevrel-phase copper molybdenum sulfide have been measured at 4.2 K as a function of applied magnetic field. Self-field critical-current values up to 10 to the 9th A/sq m were found, decreasing to 10 to the 8th A/sq m at 3 T. Graphs of pinning forces versus field were found to be independent of field direction, and the pinning mechanism is sample independent. Critical-current densities for sputtered lead molybdenum sulphide are estimated to be about 10 to the 8th A/sq m at 26 T based on a scaling law for pinning.

  9. Preparation of silver-activated zinc sulfide thin films

    NASA Technical Reports Server (NTRS)

    Feldman, C.; Swindells, F. E.

    1968-01-01

    Silver improves luminescence and reduces contamination of zinc sulfide phosphors. The silver is added after the zinc sulfide phosphors are deposited in thin films by vapor evaporation, but before calcining, by immersion in a solution of silver salt.

  10. Hydrogen sulfide to the rescue in obstructive kidney injury

    PubMed Central

    Kasinath, Balakuntalam S.

    2014-01-01

    Hydrogen sulfide is a gasotransmitter with far reaching effects on cell function. Studies show that depending on the context hydrogen sulfide can function as an ameliorative agent or as a mediator of kidney injury. PMID:24875544

  11. Mechanisms of hydrogen sulfide removal with steel making slag.

    PubMed

    Kim, Kyunghoi; Asaoka, Satoshi; Yamamoto, Tamiji; Hayakawa, Shinjiro; Takeda, Kazuhiko; Katayama, Misaki; Onoue, Takasumi

    2012-09-18

    In the present study, we experimentally investigated the removal of hydrogen sulfide using steel-making slag (SMS) and clarified the mechanism of hydrogen sulfide removal with the SMS. The results proved that SMS is able to remove hydrogen sulfide dissolved in water, and the maximum removal amount of hydrogen sulfide per unit weight of the SMS for 8 days was estimated to be 37.5 mg S/g. The removal processes of hydrogen sulfide were not only adsorption onto the SMS, but oxidation and precipitation as sulfur. The chemical forms of sulfide adsorbed onto the SMS were estimated to be sulfur and manganese sulfide in the ratio of 81% and 19%, respectively. It is demonstrated here that the SMS is a promising material to remediate organically enriched coastal sediments in terms of removal of hydrogen sulfide. Furthermore, using SMS is expected to contribute to development of a recycling-oriented society. PMID:22894171

  12. Evolution of sulfide mineralization on Mars

    SciTech Connect

    Burns, R.G.; Fisher, D.S. )

    1990-08-30

    The presence of komatiitic igneous rocks on Marks, based on geochemical evidence from SNC meteorites and Viking X ray fluorescence analyses of the regolith, suggests that massive and disseminated iron sulfide mineralization occurs near the Martian surface. Analogies are drawn between possible ultramafic Fe-Ni sulfides on Mars and terrestrial pyrrhotite-pentlandite ore deposits associated with Archean komatiites formed during early crustal development on Earth. Partial melting of the mantle as a result of high radiogenic heat production then, extrusion of turbulent high-temperature ultramafic lavas, segregation of immiscible FeS melts during cooling, gravitational settling and fractional crystallization of sulfide minerals in magma chambers or lava flows produced massive and disseminated sulfide mineralization associated with terrestrial komatiites. Comparable processes probably occurred on Mars where, on account of the inferred higher Fe/(Fe + Mg) ratio of the X ray mantle (estimated to contain {approximately}4.5 wt % S), iron-rich basaltic magmas were produced by partial melting at depths and temperatures exceeding 165 km and 1,400{degree}C, respectively. Adiabatic diapiric emplacement of these iron-rich, very low viscosity basaltic melts transported significant concentrations of dissolved sulfur as S{sup 2{minus}} and HS{sup {minus}} from the mantle. Ensuing sulfide mineralization may have been either thinly disseminated within ultramafic lavas erupting over large areas of Mars or concentrated locally at the base of structural depressions. Cumulate ore deposits several meters thick may occur at the base of intrusions or in near-surface magma chambers. The evidence for insignificant plate tectonic activity on Mars and minimal interactions of Martian mantle with crust, hydrosphere and atmosphere has restricted the evolution of sulfide ore deposits there.

  13. Modeling of Sulfide Microenvironments on Mars

    NASA Technical Reports Server (NTRS)

    Schwenzer, S. P.; Bridges, J. C.; McAdam, A.; Steer, E. D.; Conrad, P. G.; Kelley, S. P.; Wiens, R. C.; Mangold, N.; Grotzinger, J.; Eigenbrode, J. L.; Franz, H. B.; Sutter, B.

    2016-01-01

    Yellowknife Bay (YKB; sol 124-198) is the second site that the Mars Science Laboratory Rover Curiosity investigated in detail on its mission in Gale Crater. YKB represents lake bed sediments from an overall neutral pH, low salinity environment, with a mineralogical composition which includes Ca-sulfates, Fe oxide/hydroxides, Fe-sulfides, amorphous material, and trioctahedral phyllosilicates. We investigate whether sulfide alteration could be associated with ancient habitable microenvironments in the Gale mudstones. Some textural evidence for such alteration may be pre-sent in the nodules present in the mudstone.

  14. Reviewing sulfidation corrosion—Yesterday and today

    NASA Astrophysics Data System (ADS)

    Bornstein, Norman S.

    1996-11-01

    At one time, sulfidation corrosion threatened to severely limit the use of gas turbines in marine applications, markedly reduce the life of industrial gas turbines, and affect the performance of aircraft engines. Today, gas turbine engines drive U.S. naval ships, produce electricity, and power aircraft. However, the problem of sulfidation corrosion has not disappeared. The rapid rate of degradation of airfoil materials in the presence of condensed sulfates is still a concern for gas turbine engines that operate in industrial and marine environments.

  15. Classification of polytype structures of zinc sulfide

    SciTech Connect

    Laptev, V.I.

    1994-12-31

    It is suggested that the existing classification of polytype structures of zinc sulfide be supplemented with an additional criterion: the characteristic of regular point systems (Wyckoff positions) including their type, number, and multiplicity. The consideration of the Wyckoff positions allowed the establishment of construction principles of known polytype series of different symmetries and the systematization (for the first time) of the polytypes with the same number of differently packed layers. the classification suggested for polytype structures of zinc sulfide is compact and provides a basis for creating search systems. The classification table obtained can also be used for numerous silicon carbide polytypes. 8 refs., 4 tabs.

  16. Sol-gel processing of metal sulfides

    NASA Astrophysics Data System (ADS)

    Stanic, Vesha

    Metal sulfides were synthesised via a sol-gel process using various metal alkoxides and hydrogen sulfide in toluene. Colloidal gels were prepared from germanium ethoxide, germanium isopropoxide, zinc tert-butoxide and tungsten (VI) ethoxide, whereas colloidal powder was produced from tungsten (V) dichloride ethoxide. Special precautions were necessary to protect the reaction mixture from water contamination which produced metal oxides. Results indicated that the main source of water is the hydrogen sulfide gas. In addition, synthesis of metal sulfides from a mixture of metal oxide and sulfide was demonstrated by the example of monoclinic germanium disulfide. It was produced by reaction of the sol-gel product with sulfur. Heat treatment of the sol-gel product and sulfur yielded single phase GeSsb2. The sol-gel prepared materials and their heat treated products were characterized by various methods. A chemical kinetics study of the functional groups -OR, -SH and Ssp{2-} was carried out for the sol-gel processing of GeSsb2 from of hydrogen sulfide and two different alkoxides, germanium ethoxide and germanium isopropoxide. The study was performed for different concentrations of precursors at different molar ratios and temperatures. The results indicate that the proposed reaction mechanism was simplified under appropriate reaction conditions. Experimentally determined rate constants of thiolysis and condensations demonstrate that thiolysis is slow and that condensations are fast steps, regardless of the studied reaction conditions. A study of the temperature effect on the reaction rate constant shows that it increases with temperature in accord with both Arrhenius law and transition-state theory. Activation energies, Esba, and activation parameters DeltaSsp{ddagger}, DeltaHsp{ddagger} and DeltaGsp{ddagger}, were determined for thiolysis and condensation reactions. The potentiometric tiration method was used for quantitative determination of germanium sulfide and

  17. Acute inhalation toxicity of carbonyl sulfide

    SciTech Connect

    Benson, J.M.; Hahn, F.F.; Barr, E.B.

    1995-12-01

    Carbonyl sulfide (COS), a colorless gas, is a side product of industrial procedures sure as coal hydrogenation and gasification. It is structurally related to and is a metabolite of carbon disulfide. COS is metabolized in the body by carbonic anhydrase to hydrogen sulfide (H{sub 2}S), which is thought to be responsible for COS toxicity. No threshold limit value for COS has been established. Results of these studies indicate COS (with an LC{sub 50} of 590 ppm) is slightly less acutely toxic than H{sub 2}S (LC{sub 50} of 440 ppm).

  18. Method for inhibiting oxidation of metal sulfide-containing material

    DOEpatents

    Elsetinow, Alicia; Borda, Michael J.; Schoonen, Martin A.; Strongin, Daniel R.

    2006-12-26

    The present invention provides means for inhibiting the oxidation of a metal sulfide-containing material, such as ore mine waste rock or metal sulfide taiulings, by coating the metal sulfide-containing material with an oxidation-inhibiting two-tail lipid coating (12) thereon, thereby inhibiting oxidation of the metal sulfide-containing material in acid mine drainage conditions. The lipids may be selected from phospholipids, sphingolipids, glycolipids and combinations thereof.

  19. Membrane for hydrogen recovery from streams containing hydrogen sulfide

    DOEpatents

    Agarwal, Pradeep K.

    2007-01-16

    A membrane for hydrogen recovery from streams containing hydrogen sulfide is provided. The membrane comprises a substrate, a hydrogen permeable first membrane layer deposited on the substrate, and a second membrane layer deposited on the first layer. The second layer contains sulfides of transition metals and positioned on the on a feed side of the hydrogen sulfide stream. The present invention also includes a method for the direct decomposition of hydrogen sulfide to hydrogen and sulfur.

  20. Discovery of Hg-Cu-bearing metal-sulfide assemblages in a primitive H-3 chondrite: Towards a new insight in early solar system processes

    NASA Astrophysics Data System (ADS)

    Caillet Komorowski, Catherine; El Goresy, Ahmed; Miyahara, Masaaki; Boudouma, Omar; Ma, Chi

    2012-10-01

    We report here the discovery of a novel meteoritic paragenesis consisting of sub-micrometric HgS, Cu sulfides, and Hg metal, associated with polycrystalline fine-grained native Cu in opaque mineral aggregates heterogeneously distributed in the matrix of the H-3 Tieschitz unequilibrated ordinary chondrite (UOC). The systematic association of Hg with Cu in Tieschitz chondrite provides a unique opportunity to place robust constraints on the origin of these assemblages either by condensation and sulfidation in a local nebular reservoir of non-solar composition, followed by gentle and fast accretion, or by sublimation of Hg from the hot interior of the asteroid and recondensation in its cold outer regions. The sulfide phase relations support low temperature conditions (<300 °C), implying that subsequent to accretion indigenous hydrothermal processing, oxidation/sulfidation, transportation, or shock-induced thermal processing of the assemblage on the parent body earlier proposed are very unlikely and unrealistic. Origin of HgS by sublimation of Hg from the hotter asteroid interior and precipitation as cinnabar in the colder surface regions is discrepant with our findings and can be ruled out because cinnabar occurs only in Tieschitz matrix in alternating rhythmic intergrowth with Cu-sulfide. The sublimation scenario calls for co-evaporation of both the highly volatile Hg as HgS and Hg metal and the moderately volatile Cu both as Cu metal, or their sulfides and deposition as sulfides in alternating episodes. Our findings provide further ample evidence refuting the repeated claim of formation of native copper in chondritic metal by shock-induced impact melting. Cold accretion is the only reasonable possibility to preserve the delicate accretionary intergrowth textures, the polycrystallinity of FeNi-metal, native Cu, Hg-Cu-sulfides and native Hg globules and the high Hg concentration retained in this meteorite. Our findings strongly suggest that Tieschitz resided near the

  1. Hydrotreating with catalysts comprising mixtures of an amorphous sulfide or trivalent chromium and microcrystallites of molybdenum sulfide or tungsten sulfide

    SciTech Connect

    Jacobson, A.J.; Ho, T.C.; Chianelli, R.R.; Steger, J.J.; Montagna, A.A.

    1989-03-14

    A process is described for hydrorefining a hydrocarbon feed to reduce the contents of nitrogen compounds and sulfur compounds in the feed which comprises contacting the feed at an elevated temperature of at least about 150/sup 0/C and in the presence of hydrogen with a catalyst consisting essentially of a mixture of (i) an amorphous sulfide of trivalent chromium and (ii) microcrystallities of a metal sulfide of a metal selected from the group consisting of Mo, W and mixture thereof, the contacting occurring for a time sufficient to hydrorefine at least a portion of the feed. The patent also describes a process for improving the oxidation stability of a nitrogen and sulfur containing lube oil feed which comprises contacting the feed at an elevated temperature of at least about 150/sup 0/C and in the presence of hydrogen with a catalyst consisting essentially of a mixture of (i) an amorphous sulfide of trivalent chromium and (ii) microcrystallities of metal sulfides of a metal selected from the group consisting of Mo, W and mixture thereof, the contacting occurring for a time sufficient to improve the oxidation stability of the lube oil feed.

  2. 21 CFR 872.1870 - Sulfide detection device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1870 Sulfide detection device. (a) Identification. A sulfide detection device is a device consisting of an AC-powered control unit, probe handle, probe... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Sulfide detection device. 872.1870 Section...

  3. 21 CFR 872.1870 - Sulfide detection device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1870 Sulfide detection device. (a) Identification. A sulfide detection device is a device consisting of an AC-powered control unit, probe handle, probe... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Sulfide detection device. 872.1870 Section...

  4. 21 CFR 872.1870 - Sulfide detection device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1870 Sulfide detection device. (a) Identification. A sulfide detection device is a device consisting of an AC-powered control unit, probe handle, probe... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Sulfide detection device. 872.1870 Section...

  5. The effect of sulfide inhibition on the ANAMMOX process.

    PubMed

    Jin, Ren-Cun; Yang, Guang-Feng; Zhang, Qian-Qian; Ma, Chun; Yu, Jin-Jin; Xing, Bao-Shan

    2013-03-01

    The feasibility of anaerobic ammonium oxidation (ANAMMOX) process to treat wastewaters containing sulfide was studied in this work. Serum bottles were used as experimental containers in batch tests to analyze the short-term response of the ANAMMOX process under sulfide stress. The IC(50) of sulfide-S for ANAMMOX biomass was substrates-dependent and was calculated to be 264 mg L(-1) at an initial total nitrogen level of 200 mg L(-1) (molar ratio of ammonium and nitrite was 1:1). The long-term effects and the performance recovery under sulfide stress were continuously monitored and evaluated in an upflow anaerobic sludge blanket reactor. The performance of the ANAMMOX system was halved at an sulfide-S level of 32 mg L(-1) within 13 days; however, the nitrogen removal rate (NRR) decreased by only 17.2% within 18 days at an sulfide-S concentration of 40 mg L(-1) after long-time acclimatization of sludge in the presence of sulfide. The ANAMMOX performance recovered under sulfide-S level of 8 mg L(-1) with a steady NRR increasing speed, linear relationship between the NRR and operation time. The synchronic reduce in the specific ANAMMOX activity and the biomass extended the apparent doubling time of the nitrogen removal capacity and decreased biomass growth rate. PMID:23273856

  6. Seasonal and spatial patterns of metals at a restored copper mine site. I. Stream copper and zinc.

    PubMed

    Bambic, Dustin G; Alpers, Charles N; Green, Peter G; Fanelli, Eileen; Silk, Wendy K

    2006-12-01

    Seasonal and spatial variations in metal concentrations and pH were found in a stream at a restored copper mine site located near a massive sulfide deposit in the Foothill copper-zinc belt of the Sierra Nevada, California. At the mouth of the stream, copper concentrations increased and pH decreased with increased streamflow after the onset of winter rain and, unexpectedly, reached extreme values 1 or 2 months after peaks in the seasonal hydrographs. In contrast, aqueous zinc and sulfate concentrations were highest during low-flow periods. Spatial variation was assessed in 400 m of reach encompassing an acidic, metal-laden seep. At this seep, pH remained low (2-3) throughout the year, and copper concentrations were highest. In contrast, the zinc concentrations increased with downstream distance. These spatial patterns were caused by immobilization of copper by hydrous ferric oxides in benthic sediments, coupled with increasing downstream supply of zinc from groundwater seepage. PMID:16678951

  7. High adherence copper plating process

    DOEpatents

    Nignardot, Henry

    1993-01-01

    A process for applying copper to a substrate of aluminum or steel by electrodeposition and for preparing an aluminum or steel substrate for electrodeposition of copper. Practice of the invention provides good adhesion of the copper layer to the substrate.

  8. A study of the trace sulfide mineral assemblages in the Stillwater Complex, Montana, USA

    NASA Astrophysics Data System (ADS)

    Aird, Hannah M.; Ferguson, Katherine M.; Lehrer, Malia L.; Boudreau, Alan E.

    2016-07-01

    The sulfide assemblages of the Stillwater Complex away from the well-studied ore zones are composed mainly of variable proportions of pyrrhotite, chalcopyrite, pentlandite, and ±pyrite. Excluding vein assemblages and those affected by greenschist and lower temperature alteration, the majority can be classified into two broad assemblages, defined here as pristine (multiphase, often globular in shape) or volatile-bearing (multiphase, high-temperature, volatile-rich minerals such as biotite, hornblende, or an unmixed calcite-dolomite assemblage). The volatile-bearing assemblages are mainly found within and below the J-M reef, where native copper and sphalerite are also locally present. Pristine sulfides are found throughout the stratigraphy. Both groups can be affected by apparent S loss in the form of pyrite being converted to magnetite and chalcopyrite to a Cu-Fe-oxide (delafossite), with little to no silicate alteration. An upward trend from pentlandite-rich to pyrrhotite-rich to pyrite-rich assemblages is observed in the footwall rocks in upper GN-I, and the same trend repeats from just below the reef and continues into the overlying N-II and GN-II. Modeling suggests that the sulfide Ni in the Peridotite Zone is largely controlled by silicate Ni. When taken together, observations are most readily explained by the remobilization of selected elements by a high-temperature fluid with the apparent loss of S > Cu > Ni. This could concentrate ore metals by vapor refining, eventually producing a platinum group element-enriched sulfide ore zone, such as the J-M reef.

  9. Copper-containing zeolite catalysts

    DOEpatents

    Price, Geoffrey L.; Kanazirev, Vladislav

    1996-01-01

    A catalyst useful in the conversion of nitrogen oxides or in the synthesis of nitriles or imines from amines, formed by preparing an intimate mechanical mixture of a copper (II)-containing species, such as CuO or CuCl.sub.2, or elemental copper, with a zeolite having a pore mouth comprising 10 oxygen atoms, such as ZSM-5, converting the elemental copper or copper (II) to copper (I), and driving the copper (I) into the zeolite.

  10. Copper-containing zeolite catalysts

    DOEpatents

    Price, G.L.; Kanazirev, V.

    1996-12-10

    A catalyst useful in the conversion of nitrogen oxides or in the synthesis of nitriles or imines from amines, is formed by preparing an intimate mechanical mixture of a copper (II)-containing species, such as CuO or CuCl{sub 2}, or elemental copper, with a zeolite having a pore mouth comprising 10 oxygen atoms, such as ZSM-5, converting the elemental copper or copper (II) to copper (I), and driving the copper (I) into the zeolite.

  11. The diagenesis of carbohydrates by hydrogen sulfide

    NASA Astrophysics Data System (ADS)

    Mango, Frank D.

    1983-08-01

    Carbohydrates react with hydrogen sulfide under low temperature (100° to 200°C) yielding a variety of organosulfur compounds including thiophenes, thiols, sulfides and sulfones. A polymer is also produced, whose elemental composition is within the range of natural coals. When reductive dehydration is carried out in the presence of hydrocarbon, organosulfur compounds are formed in the carbon number range of the hydrocarbon used. In these processes, an active hydrogen transfer catalyst is produced which facilitates the passage of hydrogen between normal paraffins and saccharide units, distributing sulfur between these two families primarily in the form of thiophene rings. The simplicity of these systems - H 2S, carbohydrates, H 2O, hydrocarbon - and the facility of the chemistry would suggest that the carbohydrates and hydrogen sulfide may be important agents in the diagenetic processes leading to petroleum and coal. Carbohydrate reduction by hydrogen sulfide may constitute an important route through which certain organosulfur compounds found in petroleum and coal entered these materials in early diagenesis.

  12. REACTION PROCESSES OF ARSENIC IN SULFIDIC SOLUTIONS

    EPA Science Inventory

    The fate of arsenic in the environment is fundamentally linked to its speciation. Arsenic in aerobic environments is predominantly arsenate, however under reducing conditions arsenite species dominate. In anoxic or sulfidic environments thioarsenite ((As(OH)x(SH)yz-) species alon...

  13. Monitoring sulfide and sulfate-reducing bacteria

    SciTech Connect

    Tanner, R.S.

    1995-12-31

    Simple yet precise and accurate methods for monitoring sulfate-reducing bacteria (SRB) and sulfide remain useful for the study of bacterial souring and corrosion. Test kits are available to measure sulfide in field samples. A more precise methylene blue sulfide assay for both field and laboratory studies is described here. Improved media, compared to that in API RP-38, for enumeration of SRB have been formulated. One of these, API-RST, contained cysteine (1.1 mM) as a reducing agent, which may be a confounding source of sulfide. While cysteine was required for rapid enumeration of SRB from environmental samples, the concentration of cysteine in medium could be reduced to 0.4 mM. It was also determined that elevated levels of yeast extract (>1 g/liter) could interfere with enumeration of SRB from environmental samples. The API-RST medium was modified to a RST-11 medium. Other changes in medium composition, in addition to reduction of cysteine, included reduction of the concentration of phosphate from 3.4 mM to 2.2 mM, reduction of the concentration of ferrous iron from 0.8 mM to 0.5 mM and preparation of a stock mineral solution to ease medium preparation. SRB from environmental samples could be enumerated in a week in this medium.

  14. Comparison of Hydrogen Sulfide Analysis Techniques

    ERIC Educational Resources Information Center

    Bethea, Robert M.

    1973-01-01

    A summary and critique of common methods of hydrogen sulfide analysis is presented. Procedures described are: reflectance from silver plates and lead acetate-coated tiles, lead acetate and mercuric chloride paper tapes, sodium nitroprusside and methylene blue wet chemical methods, infrared spectrophotometry, and gas chromatography. (BL)

  15. Sulfide as a signaling molecule in autophagy

    PubMed Central

    Gotor, Cecilia; García, Irene; Crespo, José L.; Romero, Luis C.

    2013-01-01

    Hydrogen sulfide is already recognized as an important signaling molecule in mammalian systems, and emerging data suggest that H2S is a signaling molecule just as important as nitric oxide (NO) and H2O2 in plants. Although sulfide is generated in chloroplasts and mitochondria, it is present predominantly in the charged HS- form due to the basic pH inside both organelles, thus requiring an active transporter, which is yet to be identified, to be released. In Arabidopsis, we found that the cytosolic L-cysteine desulfhydrase DES1 is involved in the degradation of cysteine, and therefore responsible for the generation of H2S in this cellular compartment. DES1 deficiency leads to the induction of autophagy. Moreover, we have demonstrated that sulfide in particular exerts a general effect on autophagy through negative regulation, in a way unrelated to nutrient deficiency. The mechanisms of H2S action and its molecular targets are largely unknown, although in animal systems, protein S-sulfhydration has been proposed as a mechanism for sulfide-mediated signaling. PMID:23328265

  16. New Sulfide Derivatives of Vegetable Oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetable oils containing sulfide group were synthesized using a UV initiated thiol-ene reaction. The reaction involved addition of butyl thiol to the double bonds of the vegetable oil without the presence of a solvent. The effects of temperature, reaction time, type of vegetable oil, thiol to veg...

  17. 30 CFR 250.490 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... black lettering as follows: Letter height Wording 12 inches Danger. Poisonous Gas. Hydrogen Sulfide. 7... well-control techniques to prevent formation fracturing in an open hole within the pressure limits of... designed consistent with the anticipated depth, conditions of the hole, and reservoir environment to...

  18. Improved Electroformed Structural Copper and Copper Alloys

    NASA Technical Reports Server (NTRS)

    Malone, G. A.; Hudson, W.; Babcock, B.; Edwards, R.

    1998-01-01

    Electroforming offers a superior means for fabricating internally cooled heat exchangers and structures subjected to thermal environments. Copper is deposited from many such applications because of the good thermal conductivity. It suffers from mediocre yield strength as a structural material and loses mechanical strength at intermediate temperatures. Mechanical properties similar to those of electroformed nickel are desired. Phase 1 examined innovative means to improve deposited copper structural performance. Yield strengths as high as 483 MPa (70 ksi) were obtained with useful ductility while retaining a high level of purity essential to good thermal conductivity. Phase 2 represents a program to explore new additive combinations in copper electrolytes to produce a more fine, equiaxed grain which can be thermally stabilized by other techniques such as alloying in modest degrees and dispersion strengthening. Evaluation of new technology - such as the codeposition of fullerness (diamond-like) particles were made to enhance thermal conductivity in low alloys. A test fire quality tube-bundle engine was fabricated using these copper property improvement concepts to show the superiority of the new coppers and fabrications methods over competitive technologies such as brazing and plasma deposition.

  19. Atomic layer deposition of metal sulfide materials.

    PubMed

    Dasgupta, Neil P; Meng, Xiangbo; Elam, Jeffrey W; Martinson, Alex B F

    2015-02-17

    CONSPECTUS: The field of nanoscience is delivering increasingly intricate yet elegant geometric structures incorporating an ever-expanding palette of materials. Atomic layer deposition (ALD) is a powerful driver of this field, providing exceptionally conformal coatings spanning the periodic table and atomic-scale precision independent of substrate geometry. This versatility is intrinsic to ALD and results from sequential and self-limiting surface reactions. This characteristic facilitates digital synthesis, in which the film grows linearly with the number of reaction cycles. While the majority of ALD processes identified to date produce metal oxides, novel applications in areas such as energy storage, catalysis, and nanophotonics are motivating interest in sulfide materials. Recent progress in ALD of sulfides has expanded the diversity of accessible materials as well as a more complete understanding of the unique chalcogenide surface chemistry. ALD of sulfide materials typically uses metalorganic precursors and hydrogen sulfide (H2S). As in oxide ALD, the precursor chemistry is critical to controlling both the film growth and properties including roughness, crystallinity, and impurity levels. By modification of the precursor sequence, multicomponent sulfides have been deposited, although challenges remain because of the higher propensity for cation exchange reactions, greater diffusion rates, and unintentional annealing of this more labile class of materials. A deeper understanding of these surface chemical reactions has been achieved through a combination of in situ studies and quantum-chemical calculations. As this understanding matures, so does our ability to deterministically tailor film properties to new applications and more sophisticated devices. This Account highlights the attributes of ALD chemistry that are unique to metal sulfides and surveys recent applications of these materials in photovoltaics, energy storage, and photonics. Within each application

  20. Method of washing hydrogen sulfide from coke oven gas by the ammonium sulfide method

    SciTech Connect

    Ritter, H.

    1985-05-21

    An improved coke oven gas washing process for removing hydrogen sulfide is proposed wherein the coke oven gas is treated in a hydrogen sulfide scrubber by counterflow with an aqueous ammonia wash water. A stream of aqueous weak ammonia liquor is cooled and sprayed through nozzles in the mid-region of the hydrogen sulfide scrubber. A quantity of aqueous ammonia liquor, corresponding to the quantity which is sprayed through the said nozzles, is withdrawn from the hydrogen sulfide scrubber at a level below the nozzles and is introduced into the top of the said hydrogen sulfide scrubber. Ammonia vapor released at the nozzles has a higher partial pressure than the ammonia partial pressure of the coke oven gas in the region of the nozzle. The aqueous ammonia liquor from the deacidifier is the source of the cooled aqueous ammonia liquor which is introduced through the nozzles. A portion of the aqueous ammonia liquor from the deacidifier is introduced directly into the top of the hydrogen sulfide scrubber as a portion of the required aqueous ammonia wash water.

  1. Oxygen Demand of Fresh and Stored Sulfide Solutions and Sulfide-Rich Constructed Wetland Effluent.

    PubMed

    Chan, Carolyn; Farahbakhsh, Khosrow

    2015-08-01

    This study investigated the contribution of hydrogen sulfide to biological oxygen demand (BOD5) and chemical oxygen demand (COD) in wastewater effluents, and documented the effect of storage times and conditions on the BOD5 and COD of pH-adjusted sodium sulfide solutions as well as graywater wetland effluent. Initial COD measurements of sulfide solutions were 84-89% of the theoretical oxygen demand (ThOD), 1.996 mg O2/mg S, whereas unseeded BOD5 measurements were 55-77%. For sulfide solutions, all storage conditions led to declines of >15% (COD, BOD5), and >31% (sulfide). For wetland effluent, storage without headspace was effective in reducing COD losses (3.7%), compared to storage with headspace (17%), and affected changes in turbidity, UVA-254 and pH. The results suggest that storage times and conditions should be controlled and reported when reporting BOD5 and COD of sulfide-rich samples. Wetland models representing sulfate reduction as a method of COD removal may need to be reconsidered. PMID:26237688

  2. New treatment for sulfide-laden tannery waste

    SciTech Connect

    Berberich, S.

    1984-02-01

    A new treatment for tannery wastes containing toxic sulfide has been developed using anaerobic microorganisms that thrive alongside sulfide compounds. The new system, using an anaerobic reactor, transforms sulfide-laden tannery wastes into inert matter, methane, and material (including sulfide) readily digested in an aerobic polishing step. An industrial scale-up of the anaerobic reactor could digest between 60-70% of tannery pollutants. The new treatment offers leather tanneries and other industries that generate high-sulfide waste a cheaper way to meet federal water pollution guidelines.

  3. Study on the sulfidation behavior of smithsonite

    NASA Astrophysics Data System (ADS)

    Wu, Dandan; Wen, Shuming; Deng, Jiushuai; Liu, Jian; Mao, Yingbo

    2015-02-01

    Zinc extraction from low-grade mineral resources of oxidized zinc has recently become a focus of study. Sulfidation is an important process in oxidized ore flotation. In this study, the influence of sulfur ion adsorption on smithsonite surface was investigated with the use of zeta potential, inductively coupled plasma (ICP), scanning electron microscope (SEM), and X-ray photoelectron spectroscopic studies. Zeta potential measurements of sodium sulfide showed that sulfur ions were adsorbed onto the surface of pure smithsonite, as evidenced by the increased negative charge and the decrease in the pHIEP of smithsonite from 7.7 to 6 after sodium sulfide treatment. The ICP test revealed the gradual reduction in sulfur ion adsorption onto the surface of smithsonite in pulp sulfur. After 30 min of absorption, CS in the solution declined from 1000 × 10-6 mol/L to 1.4 × 10-6 mol/L. SEM results showed that the mineral surface was partially changed to ZnS film after sodium sulfide treatment, whereas EDS analysis results showed that 2% S is contained on the smithsonite surface. X-ray photoelectron spectroscopy results indicated the presence of a characteristic signal peak of sulfur ions after sulfidation. Sulfur concentration increased to 11.89%, whereas oxygen concentration decreased from 42.31% to 13.74%. Sulfur ions were not only present during chemical adsorption, but were also incorporated into the crystal lattices of minerals by the exchange reaction between S2- and CO32- ions.

  4. Sulfidization and magnetization above hydrocarbon reservoirs

    SciTech Connect

    Reynolds, R.L.; Goldhaber, M.B.; Tuttle, M.L. )

    1991-03-01

    Geochemical and rock magnetic studies of strata over Cement oil field (Anadarko basin, Oklahoma), Simpson oil field (North Slope basin, Alaska), and the Edwards deep gas trend, south Texas coastal plain, document changes in original magnetizations caused by postdepositional iron sulfide minerals that are, or may be, related to hydrocarbon seepage. At Cement, ferrimagnetic pyrrhotite (Fe{sub 7}S{sub 8}) formed with pyrite and marcasite in Permian red beds. The Fe-S minerals contain isotopically heavy, abiogenic sulfur derived from thermal degradation of petroleum and (or) isotopically light sulfur derived from sulfate-reducing bacteria fed by leaking hydrocarbons. At Simpson, ferrimagnetic greigite (Fe{sub 3}S{sub 4}) dominates magnetizations in Upper Cretaceous nonmarine beds that contain biodegraded oil. Sulfur isotopic data are consistent with, but do not prove, a genetic link between the greigite ({delta}{sup 34}S {gt} +20 per mil) and seepage. In middle Tertiary sandstones of southeast Texas, pyrite and marcasite formed when abiogenic H{sub 2}S migrated upward from deep reservoirs, or when H{sub 2}S was produced at shallow depths by bacteria that utilized organic material dissolved in migrating water from depth. The sulfide minerals replaced detrital magnetite to result in a systematic decrease in magnetic susceptibility toward faults that connect deep petroleum reservoirs to shallow sandstone. The authors results show that abiologic and biologic mechanisms can generate magnetic sulfide minerals in some sulfidic zones of hydrocarbon seepage. The magnetizations in such zones are diminished most commonly by replacement of detrital magnetic minerals with nonmagnetic sulfide minerals or are unchanged if such detrital minerals were originally absent.

  5. Analog Experiments on Sulfide Foams in Magmatic Ore Deposits

    NASA Astrophysics Data System (ADS)

    Leitch, A. M.; Dahn, D.; Zavala, K.

    2009-05-01

    Metal sulfides form as an immiscible phase from silicate magmas. Dynamic mingling and unmingling of the two phases is important for the development of economic deposits: mingling promotes enrichment of the sulfide in valuable metals, and subsequent unmingling generates massive sulfide. Analog experiments were carried out to investigate mingling processes in immiscible systems, using oil, water and small beads to represent magma, sulfide liquid and silicate crystals. Stirring or injection led to the formation of a foam of analog sulfide droplets within an analog silicate framework. We propose that the partial collapse of such a foam explains massive sulfide lenses at the Voisey's Bay magmatic sulfide deposit, and that crystallization of silicate crystals in the remaining foam walls generates 'net-textured' ores. In the experiments, solid particles had a profound effect on unmingling: analog sulfide droplets were stably contained within analog crystal-rich magma and did not coalesce. We therefore suggest that 'net' and 'leopard' textures in disseminated sulfides indicate mingling of sulfide with crystal-poor magma, whereas isolated disseminated patches of sulfide indicate mingling with a crystal-rich magma.

  6. Effect of sulfide on growth of marine bacteria.

    PubMed

    Mirzoyan, Natella; Schreier, Harold J

    2014-04-01

    Severe hypoxia leads to excess production of hydrogen sulfide in marine environments. In this study, we examined the effect of sulfide on growth of four facultative anaerobic marine bacteria in minimal media under anaerobic conditions. The Gram-negative chemolithoautotrophic Marinobacter sp. tolerated sulfide concentrations up to 0.60 mM, with doubling and lag times increasing as a function of increasing sulfide concentration but with no change in maximum culture yields; growth did not occur at 1.2 mM sulfide. Similar results were obtained for the metabolically diverse Gram-negative denitrifying Pseudomonas stutzeri, except that growth occurred at 1.2 mM and culture yields at 0.60 and 1.2 mM sulfide were approximately 10-fold lower than at sulfide concentrations between 0 and 0.30 mM. Increases in doubling and lag times accompanied by an overall 10-fold decrease in maximum culture yields were found for the Gram-negative chemoheterotrophic Vibrio sp. at all sulfide concentrations tested. In contrast, growth of a Gram-positive chemoheterotrophic Bacillus sp. was resistant to all sulfide concentrations tested (0.15-1.2 mM). Our results highlight the variable responses of marine bacteria to sulfide and provide some insight into shifts that may occur in microbial community structure and diversity as a consequence of changes in sulfide levels that are the result of hypoxia. PMID:24609188

  7. Microbial oxidation of mixtures of methylmercaptan and hydrogen sulfide.

    PubMed

    Subramaniyan, A; Kolhatkar, R; Sublette, K L; Beitle, R

    1998-01-01

    Refinery spent-sulfidic caustic, containing only inorganic sulfides, has previously been shown to be amenable to biotreatment with Thiobacillus denitrificans strain F with complete oxidation of sulfides to sulfate. However, many spent caustics contain mercaptans that cannot be metabolized by this strict autotroph. An aerobic enrichment culture was developed from mixed Thiobacilli and activated sludge that was capable of simultaneous oxidation of inorganic sulfide and mercaptans using hydrogen sulfide (H2S) and methylmercaptan (MeSH) gas feeds used to simulate the inorganic and organic sulfur of a spent-sulfidic caustic. The enrichment culture was also capable of biotreatment of an actual mercaptan-containing, spent-sulfidic caustic but at lower rates than predicted by operation on MeSH and H2S fed to the culture in the gas phase, indicating that the caustic contained other inhibitory components. PMID:18576062

  8. Uranium-bearing copper deposits in the Coyote district, Mora County, New Mexico

    USGS Publications Warehouse

    Zeller, H.D.; Baltz, Elmer Harold

    1954-01-01

    Uranium-bearing copper deposits occur in steeply dipping beds of the Sangre de Cristo formation of Pennsylvanian and Permian(?) age south of Coyote, Mora County, N. Mex. Mapping and sampling of these deposits indicate that they are found in lenticular carbonaceous zones in shales and arkosic sandstones. Samples from these zones contain as much as 0.067 percent uranium and average 3 percent copper. Metatyuyamunite is dissemihatedin some of the arkosic sandstone beds, and uraninite is present in some of the copper sulfide nodules occurring in the shale. These sulfide nodules are composed principally of chalcocite but include some bornite, covellite, pyrite, and malachite. Most of the samples were collected near the surface from the weathered zone. The copper and uranium were probably deposited with the sediments and concentrated into zones during compaction and lithification. Carbonaceous material in the Sangre de Cristo formation provided the environment that precipitated uranium and copper from mineral-charged connate waters forced from the clayey sediments.

  9. Bioaccessibility and Solubility of Copper in Copper-Treated Lumber

    EPA Science Inventory

    Micronized copper (MC)-treated lumber is a recent replacement for Chromated Copper Arsenate (CCA) and Ammonium Copper (AC)-treated lumbers; though little is known about the potential risk of copper (Cu) exposure from incidental ingestion of MC-treated wood. The bioaccessibility o...

  10. Selective chemical dissolution of sulfides: An evaluation of six methods applicable to assaying sulfide-bound nickel

    USGS Publications Warehouse

    Klock, P.R.; Czamanske, G.K.; Foose, M.; Pesek, J.

    1986-01-01

    Six analytical techniques for the selective chemical dissolution of sulfides are compared with the purpose of defining the best method for accurately determining the concentration of sulfide-bound nickel. Synthesized sulfide phases of known elemental content, mixed with well-analyzed silicates, were used to determine the relative and absolute efficiency, based on Ni and Mg recovery, of the techniques. Tested leach-methods purported to dissolve sulfide from silicate phases include: brominated water, brominated water-carbon tetrachloride, nitric-hydrochloric acid, hydrogen peroxide-ammonium citrate, bromine-methanol and hydrogen peroxide-ascorbic acid. Only the hydrogen peroxide-ammonium citrate method did not prove adequate in dissolving the sulfide phases. The remaining five methods dissolved the sulfide phases, but the indicated amount of attack on the silicate portion ranged from 3% to 100%. The bromine-methanol method is recommended for assaying sulfide-Ni deposits when Ni is also present in silicate phases. ?? 1986.

  11. Arsenic speciation in natural sulfidic geothermal waters

    NASA Astrophysics Data System (ADS)

    Keller, Nicole S.; Stefánsson, Andri; Sigfússon, Bergur

    2014-10-01

    The speciation of arsenic in natural sulfidic geothermal waters was studied using chemical analyses and thermodynamic aqueous speciation calculations. Samples were collected in three geothermal systems in Iceland, having contrasting H2S concentrations in the reservoir (high vs. low). The sampled waters contained 7-116 ppb As and <0.01-77.6 ppm H2S with pH of 8.56-9.60. The analytical setup used for the determination of arsenic species (Ion Chromatography-Hydride Generation Atomic Fluorescence Spectrometry, IC-HG-AFS) was field-deployed and the samples analyzed within ∼5 min of sampling in order to prevent changes upon storage, which were shown to be considerable regardless of the sample storage method used. Nine aqueous arsenic species were detected, among others arsenite (HnAsO3n-3), thioarsenite (HnAsS3n-3), arsenate (HnAsO4n-3), monothioarsenate (HnAsSO3n-3), dithioarsenate (HnAsS2O2n-3), trithioarsenate (HnAsS3O) and tetrathioarsenate (HnAsS4n-3). The results of the measured aqueous arsenic speciation in the natural geothermal waters and comparison with thermodynamic calculations reveal that the predominant factors determining the species distribution are sulfide concentration and pH. In alkaline waters with low sulfide concentrations the predominant species are AsIII oxyanions. This can be seen in samples from a liquid-only well, tapping water that is H2S-poor and free of oxygen. At intermediate sulfide concentration AsIII and AsV thio species become important and predominate at high sulfide concentration, as seen in two-phase well waters, which have high H2S concentrations in the reservoir. Upon oxidation, for instance due to mixing of the reservoir fluid with oxygenated water upon ascent to the surface, AsV oxyanions form, as well as AsV thio complexes if the sulfide concentration is intermediate to high. This oxidation process can be seen in samples from hot springs in the Geysir geothermal area. While the thermodynamic modeling allows for a first

  12. Investigation of Copper Ammonia Leaching from Smelter Slags: Characterization, Leaching and Kinetics

    NASA Astrophysics Data System (ADS)

    Bidari, Ehsan; Aghazadeh, Valeh

    2015-10-01

    Although ammonia leaching of copper from slags has been reported generally as a part of copper slag utilization methods, but no detailed studies have been reported in the literature. In this research, we tried to investigate the effect of different parameters on ammonia leaching of copper from copper smelting slag by identifying different copper-bearing phases and following them during leaching time. Mineralogical characterization of the smelting slag (1.7 pct Cu) was done using X-ray fluorescence, X-ray diffraction, optical microscopy, diagnostic leaching tests, and scanning electron microscopy. The characterization studies indicated that main copper-bearing species are soluble copper oxides and chalcocite along with minor amount of covellite, bornite, blister copper particles, and chalcopyrite. It was also found that only approximately 0.2 pct Cu was present in the insoluble bulk silicate phases. These results suggest that approximately 88 pct of the total copper of slag could be extracted by ammonia sulfide leaching. Leaching tests were carried out and the effects of various parameters, namely pH, ammonia concentration, temperature, presence of oxygen, stirring speed, and pulp density were examined on copper leaching. The temperature and stirring speed had the most pronounced effect on the copper leaching, whereas ammonia affected the leaching yield at low concentrations of ammonia. It was found that 78 pct of Cu could be extracted within 4 hours and under optimum conditions: T = 343 K (70 °C), 2M ammonia, pH 10.5, stirring speed = 900 rpm, pulp density = 10 pct ( w s/ v). The kinetic data were analyzed with the shrinking core models, and it was found that the leaching process is controlled by both the interfacial transfer and diffusion across the product layer and the activation energy is calculated to be 49.4 kJ mol-1.

  13. The mineralogy and the isotopic composition of sulfur in hydrothermal sulfide/sulfate deposits on the East Pacific Rise, 21 deg N latitude

    NASA Technical Reports Server (NTRS)

    Styrt, M. M.; Brackmann, A. J.; Holland, H. D.; Clark, B. C.; Pisutha-Arnond, V.; Eldridge, C. S.; Ohmoto, H.

    1981-01-01

    The mineralogy and isotopic composition of sulfur found in hydrothermal deposits associated with five groups of vents along the ridge axis of the East Pacific Rise near 21 deg N latitude are investigated. Solid samples of mixed sulfides and sulfates from mounds, chimneys and the surrounding sediment as well as fresh basaltic glass were examined with a portable X-ray fluorescence spectrometer and by scanning electron microscopy, X-ray diffractometry, and electron microprobe analysis. For the three vents of exit temperature close to 350 C, the chimneys are found to be rich in copper sulfides, while for those of temperatures around 300 C, zinc sulfide is found to predominate. The major sulfides found in the chimneys include wurtzite, chalcopyrite, pyrite and cubanite, with anhydrite the dominant sulfate. Significant mineralogical differences are found between active and inactive vents. The isotopic composition of sulfur in anhydrites from active vents is observed to be close to that of sea water and consistent with a derivation from sea water sulfate. The isotopic composition of sulfur in the sulfide minerals is explained in terms of precipitation from solutions with reduced sulfur derived from basalts or basaltic magmas, and sea water sulfate. Finally, the deposits are interpreted as the results of the mixing of H2S-dominated hydrothermal fluids with cold sea water near the sea floor.

  14. COPPER CABLE RECYCLING TECHNOLOGY

    SciTech Connect

    Chelsea Hubbard

    2001-05-01

    The United States Department of Energy (DOE) continually seeks safer and more cost-effective technologies for use in deactivation and decommissioning (D&D) of nuclear facilities. The Deactivation and Decommissioning Focus Area (DDFA) of the DOE's Office of Science and Technology (OST) sponsors large-scale demonstration and deployment projects (LSDDPs). At these LSDDPs, developers and vendors of improved or innovative technologies showcase products that are potentially beneficial to the DOE's projects and to others in the D&D community. Benefits sought include decreased health and safety risks to personnel and the environment, increased productivity, and decreased costs of operation. The Idaho National Engineering and Environmental Laboratory (INEEL) generated a list of statements defining specific needs and problems where improved technology could be incorporated into ongoing D&D tasks. One such need is to reduce the volume of waste copper wire and cable generated by D&D. Deactivation and decommissioning activities of nuclear facilities generates hundreds of tons of contaminated copper cable, which are sent to radioactive waste disposal sites. The Copper Cable Recycling Technology separates the clean copper from contaminated insulation and dust materials in these cables. The recovered copper can then be reclaimed and, more importantly, landfill disposal volumes can be reduced. The existing baseline technology for disposing radioactively contaminated cables is to package the cables in wooden storage boxes and dispose of the cables in radioactive waste disposal sites. The Copper Cable Recycling Technology is applicable to facility decommissioning projects at many Department of Energy (DOE) nuclear facilities and commercial nuclear power plants undergoing decommissioning activities. The INEEL Copper Cable Recycling Technology Demonstration investigated the effectiveness and efficiency to recycle 13.5 tons of copper cable. To determine the effectiveness of separating

  15. Sulfide Intrusion and Detoxification in the Seagrass Zostera marina.

    PubMed

    Hasler-Sheetal, Harald; Holmer, Marianne

    2015-01-01

    Gaseous sulfide intrusion into seagrasses growing in sulfidic sediments causes little or no harm to the plant, indicating the presence of an unknown sulfide tolerance or detoxification mechanism. We assessed such mechanism in the seagrass Zostera marina in the laboratory and in the field with scanning electron microscopy coupled to energy dispersive X-ray spectroscopy, chromatographic and spectrophotometric methods, and stable isotope tracing coupled with a mass balance of sulfur compounds. We found that Z. marina detoxified gaseous sediment-derived sulfide through incorporation and that most of the detoxification occurred in underground tissues, where sulfide intrusion was greatest. Elemental sulfur was a major detoxification compound, precipitating on the inner wall of the aerenchyma of underground tissues. Sulfide was metabolized into thiols and entered the plant sulfur metabolism as well as being stored as sulfate throughout the plant. We conclude that avoidance of sulfide exposure by reoxidation of sulfide in the rhizosphere or aerenchyma and tolerance of sulfide intrusion by incorporation of sulfur in the plant are likely major survival strategies of seagrasses in sulfidic sediments. PMID:26030258

  16. Sulfide Intrusion and Detoxification in the Seagrass Zostera marina

    PubMed Central

    Hasler-Sheetal, Harald; Holmer, Marianne

    2015-01-01

    Gaseous sulfide intrusion into seagrasses growing in sulfidic sediments causes little or no harm to the plant, indicating the presence of an unknown sulfide tolerance or detoxification mechanism. We assessed such mechanism in the seagrass Zostera marina in the laboratory and in the field with scanning electron microscopy coupled to energy dispersive X-ray spectroscopy, chromatographic and spectrophotometric methods, and stable isotope tracing coupled with a mass balance of sulfur compounds. We found that Z. marina detoxified gaseous sediment-derived sulfide through incorporation and that most of the detoxification occurred in underground tissues, where sulfide intrusion was greatest. Elemental sulfur was a major detoxification compound, precipitating on the inner wall of the aerenchyma of underground tissues. Sulfide was metabolized into thiols and entered the plant sulfur metabolism as well as being stored as sulfate throughout the plant. We conclude that avoidance of sulfide exposure by reoxidation of sulfide in the rhizosphere or aerenchyma and tolerance of sulfide intrusion by incorporation of sulfur in the plant are likely major survival strategies of seagrasses in sulfidic sediments. PMID:26030258

  17. Enhanced reductive dechlorination of trichloroethylene by sulfidated nanoscale zerovalent iron.

    PubMed

    Rajajayavel, Sai Rajasekar C; Ghoshal, Subhasis

    2015-07-01

    Direct injection of reactive nanoscale zerovalent iron particles (NZVI) is considered to be a promising approach for remediation of aquifers contaminated by chlorinated organic pollutants. In this study we show that the extent of sulfidation of NZVI enhances the rate of dechlorination of trichloroethylene (TCE) compared to that by unamended NZVI, and the enhancement depends on the Fe/S molar ratio. Experiments where TCE was reacted with NZVI sulfidated to different extents (Fe/S molar ratios 0.62-66) showed that the surface-area normalized first-order TCE degradation rate constant increased up to 40 folds compared to non-sulfidated NZVI. Fe/S ratios in the range of 12-25 provided the highest TCE dechlorination rates, and rates decreased at both higher and lower Fe/S. In contrast, sulfidated NZVI exposed to water in the absence of TCE showed significantly lower hydrogen evolution rate (2.75 μmol L(-1) h(-1)) compared to that by an unamended NZVI (6.92 μmol L(-1) h(-1)), indicating that sulfidation of NZVI suppressed corrosion reactions with water. Sulfide (HS(-)) ions reacted rapidly with NZVI and X-ray photoelectron spectroscopy analyses showed formation of a surface layer of FeS and FeS2. We propose that more electrons are preferentially conducted from sulfidated NZVI than from unamended NZVI to TCE, likely because of greater binding of TCE on the reactive sites of the iron sulfide outer layer. Resuspending sulfidated NZVI in sulfide-free or sulfide containing solutions altered the TCE degradation rate constants because of changes in the FeS layer thickness. Sulfidated NZVI maintained its high reactivity in the presence of multiple mono and divalent ions and with polyelectrolyte coatings. Thus, sulfide ions in groundwater can significantly alter NZVI reactivity. PMID:25935369

  18. The Evolution of Sulfide Tolerance in the Cyanobacteria

    NASA Technical Reports Server (NTRS)

    Miller, Scott R.; Bebout, Brad M.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Understanding how the function of extant microorganisms has recorded both their evolutionary histories and their past interactions with the environment is a stated goal of astrobiology. We are taking a multidisciplinary approach to investigate the diversification of sulfide tolerance mechanisms in the cyanobacteria, which vary both in their degree of exposure to sulfide and in their capacity to tolerate this inhibitor of photosynthetic electron transport. Since conditions were very reducing during the first part of Earth's history and detrital sulfides have been found in Archean sediments, mechanisms conferring sulfide tolerance may have been important for the evolutionary success of the ancestors of extant cyanobacteria. Two tolerance mechanisms have been identified in this group: (1) resistance of photosystem II, the principal target of sulfide toxicity; and (2) maintenance of the ability to fix carbon despite photosystem II inhibition by utilizing sulfide as an electron donor in photosystem I - dependent, anoxygenic photosynthesis. We are presently collecting comparative data on aspects of sulfide physiology for laboratory clones isolated from a variety of habitats. These data will be analyzed within a phylogenetic framework inferred from molecular sequence data collected for these clones to test how frequently different mechanisms of tolerance have evolved and which tolerance mechanism evolved first. In addition, by analyzing these physiological data together with environmental sulfide data collected from our research sites using microelectrodes, we can also test whether the breadth of an organism's sulfide tolerance can be predicted from the magnitude of variation in environmental sulfide concentration it has experienced in its recent evolutionary past and whether greater average sulfide concentration and/or temporal variability in sulfide favors the evolution of a particular mechanism of sulfide tolerance.

  19. Chemical composition, morphology and optical properties of zinc sulfide coatings deposited by low-energy electron beam evaporation

    NASA Astrophysics Data System (ADS)

    Ragachev, A. V.; Yarmolenko, M. A.; Rogachev, A. A.; Gorbachev, D. L.; Zhou, Bing

    2014-06-01

    The research determines the features of formation, morphology, chemical composition and optical properties of the coatings deposited by the method, proposed for the first time, of the exposure of mechanical mixture of zinc and sulfur powders to low-energy electron beam evaporation. The findings show that the deposited coatings are characterized by high chemical and structural homogeneity in thickness. The study considers the influence of substrate temperature and thickness of the deposited layer on the morphology and the width of the formed ZnS thin layers band gap. Also was shown the possibility to form ZnS coatings with this method using the mixture of zinc and copper sulfide powders.

  20. Copper as a biocidal tool.

    PubMed

    Borkow, Gadi; Gabbay, Jeffrey

    2005-01-01

    Copper ions, either alone or in copper complexes, have been used to disinfect liquids, solids and human tissue for centuries. Today copper is used as a water purifier, algaecide, fungicide, nematocide, molluscicide as well as an anti-bacterial and anti-fouling agent. Copper also displays potent anti-viral activity. This article reviews (i) the biocidal properties of copper; (ii) the possible mechanisms by which copper is toxic to microorganisms; and (iii) the systems by which many microorganisms resist high concentrations of heavy metals, with an emphasis on copper. PMID:16101497

  1. Fabricating Copper Nanotubes by Electrodeposition

    NASA Technical Reports Server (NTRS)

    Yang, E. H.; Ramsey, Christopher; Bae, Youngsam; Choi, Daniel

    2009-01-01

    Copper tubes having diameters between about 100 and about 200 nm have been fabricated by electrodeposition of copper into the pores of alumina nanopore membranes. Copper nanotubes are under consideration as alternatives to copper nanorods and nanowires for applications involving thermal and/or electrical contacts, wherein the greater specific areas of nanotubes could afford lower effective thermal and/or electrical resistivities. Heretofore, copper nanorods and nanowires have been fabricated by a combination of electrodeposition and a conventional expensive lithographic process. The present electrodeposition-based process for fabricating copper nanotubes costs less and enables production of copper nanotubes at greater rate.

  2. Cadmium zinc sulfide by solution growth

    DOEpatents

    Chen, Wen S.

    1992-05-12

    A process for depositing thin layers of a II-VI compound cadmium zinc sulfide (CdZnS) by an aqueous solution growth technique with quality suitable for high efficiency photovoltaic or other devices which can benefit from the band edge shift resulting from the inclusion of Zn in the sulfide. A first solution comprising CdCl.sub.2 2.5H.sub.2 O, NH.sub.4 Cl, NH.sub.4 OH and ZnCl.sub.2, and a second solution comprising thiourea ((NH.sub.2).sub.2 CS) are combined and placed in a deposition cell, along with a substrate to form a thin i.e. 10 nm film of CdZnS on the substrate. This process can be sequentially repeated with to achieve deposition of independent multiple layers having different Zn concentrations.

  3. Removal of hydrogen sulfide from drilling fluids

    SciTech Connect

    Gilligan Jr., T. J.

    1985-10-22

    The present invention relates to a process for scavenging hydrogen sulfide which frequently becomes entrained in drilling fluid during the course of drilling operations through subterranean formations. The process consists of introducing a solid oxidant in powdered form into the circulating drilling fluid when hydrogen sulfide is encountered. The solid oxidants are selected from the group consisting of calcium hypochlorite (Ca-(OCl)/sub 2/), sodium perborate (NaBO/sub 3/), potassium permanganate (KMnO/sub 4/), and potassium peroxydisulfate (K/sub 2/S/sub 2/O/sub 8/). The solid oxidants are soluble in the drilling fluid, promoting fast and complete scavenging reactions without adversely altering the drilling fluid rheology.

  4. Absorption of carbonyl sulfide in aqueous methyldiethanolamine

    SciTech Connect

    Al-Ghawas, H.A.; Ruiz-Ibanez, G.; Sandall, O.C. )

    1988-01-01

    The absorption of carbonyl sulfide in aqueous methyldiethanolamine (MDEA) was studied over a range of temperatures and MDEA concentrations. MDEA is commonly used for selective absorption of hydrogen sulfide in the presence of carbon dioxide. However, sulfur in the form of COS may also be present and it is necessary that estimates of absorption rates of this compound be made. The objective of this study is to determine the physiochemical properties needed to predict COS absorption rates in aqueous MDEA. Free gas solubility and the diffusivity of COS in MDEA solutions were measured over the temperature range 15 to 40{sup 0}C for MDEA concentrations up to 30 weight per cent using the nitrous oxide analogy method. Solubilities were measured volumetrically in an equilibrium cell and diffusivities were measured using a laminar liquid jet absorber. The kinetics of the reaction between COS and MDEA were studied by measuring absorption rates in a single wetted-sphere absorber.

  5. Speciation of arsenic in sulfidic waters

    PubMed Central

    Wilkin, Richard T; Wallschläger, Dirk; Ford, Robert G

    2003-01-01

    Formation constants for thioarsenite species have been determined in dilute solutions at 25°C, ΣH2S from 10-7.5 to 10-3.0 M, ΣAs from 10-5.6 to 10-4.8 M, and pH 7 and 10. The principal inorganic arsenic species in anoxic aquatic systems are arsenite, As(OH)30, and a mononuclear thioarsenite with an S/As ratio of 3:1. Thioarsenic species with S/As ratios of 1 : 1,2 : 1, and 4 : 1 are lesser components in sulfidic solutions that might be encountered in natural aquatic environments. Thioarsenites dominate arsenic speciation at sulfide concentrations > 10-4.3 M at neutral pH. Conversion from neutral As(OH)30 to anionic thioarsenite species may regulate the transport and fate of arsenic in sulfate-reducing environments by governing sorption and mineral precipitation reactions.

  6. Sulfide stress corrosion cracking of line pipe

    SciTech Connect

    Kimuro, M.; Totsuka, N.; Kurisu, T.; Amano, K.; Matsuyama, J.; Nakai, Y. )

    1989-04-01

    This paper reports the sulfide stress corrosion cracking (SSC) behavior of line pipe steel investigated using the SSC test method in NACE Standard TMO177-77, Testing of Metals for Resistance to Sulfide Stress Cracking at Ambient Temperatures. SSC of base metal can be classified into two types, depending on microstructures. In ferrite-perlite steel, the first crack initiates parallel to the pipe surface and propagates perpendicularly to the axis of stress. In ferrite-bainite steel or low C-bainite steel, the crack initiates at the interface between the bainite particle and the ferrite. With decreasing carbon content, the threshold stress of SSC ({sigma}{sub th}) increases, but in low-carbon steel, the {sigma}{sub th} value of weld seam is lower than that of base metal. SSC of weld seams occurs at the softening zone in the heat-affected zone (HAZ) about 2 to 4 mm away from the fusion line.

  7. Iron-sulfide redox flow batteries

    DOEpatents

    Xia, Guan-Guang; Yang, Zhenguo; Li, Liyu; Kim, Soowhan; Liu, Jun; Graff, Gordon L

    2013-12-17

    Iron-sulfide redox flow battery (RFB) systems can be advantageous for energy storage, particularly when the electrolytes have pH values greater than 6. Such systems can exhibit excellent energy conversion efficiency and stability and can utilize low-cost materials that are relatively safer and more environmentally friendly. One example of an iron-sulfide RFB is characterized by a positive electrolyte that comprises Fe(III) and/or Fe(II) in a positive electrolyte supporting solution, a negative electrolyte that comprises S.sup.2- and/or S in a negative electrolyte supporting solution, and a membrane, or a separator, that separates the positive electrolyte and electrode from the negative electrolyte and electrode.

  8. Iron-sulfide redox flow batteries

    DOEpatents

    Xia, Guanguang; Yang, Zhenguo; Li, Liyu; Kim, Soowhan; Liu, Jun; Graff, Gordon L

    2016-06-14

    Iron-sulfide redox flow battery (RFB) systems can be advantageous for energy storage, particularly when the electrolytes have pH values greater than 6. Such systems can exhibit excellent energy conversion efficiency and stability and can utilize low-cost materials that are relatively safer and more environmentally friendly. One example of an iron-sulfide RFB is characterized by a positive electrolyte that comprises Fe(III) and/or Fe(II) in a positive electrolyte supporting solution, a negative electrolyte that comprises S.sup.2- and/or S in a negative electrolyte supporting solution, and a membrane, or a separator, that separates the positive electrolyte and electrode from the negative electrolyte and electrode.

  9. Single-layer transition metal sulfide catalysts

    DOEpatents

    Thoma, Steven G.

    2011-05-31

    Transition Metal Sulfides (TMS), such as molybdenum disulfide (MoS.sub.2), are the petroleum industry's "workhorse" catalysts for upgrading heavy petroleum feedstocks and removing sulfur, nitrogen and other pollutants from fuels. We have developed an improved synthesis technique to produce SLTMS catalysts, such as molybdenum disulfide, with potentially greater activity and specificity than those currently available. Applications for this technology include heavy feed upgrading, in-situ catalysis, bio-fuel conversion and coal liquefaction.

  10. Hydrogen sulfide prodrugs—a review

    PubMed Central

    Zheng, Yueqin; Ji, Xingyue; Ji, Kaili; Wang, Binghe

    2015-01-01

    Hydrogen sulfide (H2S) is recognized as one of three gasotransmitters together with nitric oxide (NO) and carbon monoxide (CO). As a signaling molecule, H2S plays an important role in physiology and shows great potential in pharmaceutical applications. Along this line, there is a need for the development of H2S prodrugs for various reasons. In this review, we summarize different H2S prodrugs, their chemical properties, and some of their potential therapeutic applications. PMID:26579468

  11. Subsurface heaters with low sulfidation rates

    SciTech Connect

    John, Randy Carl; Vinegar, Harold J

    2013-12-10

    A system for heating a hydrocarbon containing formation includes a heater having an elongated ferromagnetic metal heater section. The heater is located in an opening in a formation. The heater section is configured to heat the hydrocarbon containing formation. The exposed ferromagnetic metal has a sulfidation rate that goes down with increasing temperature of the heater, when the heater is in a selected temperature range.

  12. Hydrogen sulfide prodrugs-a review.

    PubMed

    Zheng, Yueqin; Ji, Xingyue; Ji, Kaili; Wang, Binghe

    2015-09-01

    Hydrogen sulfide (H2S) is recognized as one of three gasotransmitters together with nitric oxide (NO) and carbon monoxide (CO). As a signaling molecule, H2S plays an important role in physiology and shows great potential in pharmaceutical applications. Along this line, there is a need for the development of H2S prodrugs for various reasons. In this review, we summarize different H2S prodrugs, their chemical properties, and some of their potential therapeutic applications. PMID:26579468

  13. Redetermination of piperidinium hydrogen sulfide structure

    NASA Technical Reports Server (NTRS)

    Andras, Maria T.; Hepp, Aloysius F.; Fanwick, Phillip E.; Duraj, Stan A.; Gordon, Edward M.

    1994-01-01

    The presence of adventitious water in a reaction between dicyclopentamethylene thiuram-disulfide (C5H10NCS2)(sub 2) and a picoline solution of tricyclopentadienyl indium(III) (C5H5)(sub 3). It resulted in the formation of piperidinium hydrogen sulfide (C5H13NS). The piperidinium hydrogen sulfide produced in this way was unambiguously characterized by X-ray crystallography. The structure determination showed that the piperidinium hydrogen sulfide crystal (MW = 119.23 g/mol) has an orthorhombic (Pbcm) unit cell whose parameters are: a = 9.818(2), b = 7.3720(1), c = 9.754(1) A, V = 706.0(3) A(exp 3), Z=4. D(sub chi) = 1.122 g cm(exp -3), Mo K(alpha) (lamda = 0.71073), mu= 3.36 cm(exp -1), F(000) = 264.0, T =293 K, R = 0.036 for 343 reflections with F(sub O)(sup 2) greater than 3 sigma (F(sub O)(sup 2)) and 65 variables. The compound consists of (C5H10NH2)(+) cations and (SH)(-) anions with both species residing on crystallographic mirror planes. N-H -- S hydrogen bonding contributes to the interconnection of neighboring piperidinium components of the compound.

  14. Precambrian oil inclusions in late veins and the role of hydrocarbons in copper mineralization at White Pine, Michigan

    NASA Astrophysics Data System (ADS)

    Kelly, William C.; Nishioka, Gail K.

    1985-05-01

    Liquid oil was trapped as primary fluid inclusions in calcite crystals in late Cu-Fe sulfide-bearing veins that crosscut and offset the cupriferous shale deposit at White Pine. The age of the calcite (1047 ±35 Ma) is an entrapment age and thus a minimum age for the oil. Close temporal and spatial associations of oil and metallic sulfides in the late veins suggest that liquid and solid hydrocarbons may have been dominant controls of the main-stage White Pine copper mineralization.

  15. Uranium in the Copper King Mine, Black Hawk No. 1 Claim, Larimer County, Colorado

    USGS Publications Warehouse

    Granger, Harry Clifford; King, Robert Ugstad

    1951-01-01

    Radioactive rock was discovered on the dump of the Copper King mine, sec. 8, T. 10 N., R. 72 W., Larirrier County, Colo., in the summer of 1949. The mine had been prospected intermittently for copper and zinc since 1,916, but there is no record that ore was produced. The country rock is pre-Cambrian granite containing many schist inclusions and narrow pegmatite dikes. Pitchblende disseminated in chlorite and sulfides was deposited in an obscure vein system during an intermediate stage of mineralization. This stage was preceded by biotitic alteration of amphiboles and sulfide deposition. The latest stage of mineralization is represented-by the limonitic dense quartz vein followed during mining. The uranium-bearing vein is about 2-3 feet wide and the dense quartz vein is less than 6 inches wide. Both veins are bordered by 1-3 feet of biotite- and sulfide-bearing granite and arriphibole schist. The uranium content of 26 samples taken in the mine and on the dump ranges from 0.002 to 1.40 percent. These samples contained as much as 2.97 percent copper and 5.96 percent zinc. The general outlook for further prospecting near the Copper King shaft is not favorable, because much of the 'immediately surrounding area has been thoroughly investigated without finding abnormal radioactivity. The most favorable environment for concentration of uranium minerals appears to have been in or near schist inclusions in granite, and further exploration in nearby prospects may result in the discovery of other uranium-bearing deposits. In the Copper King mine, additional exploration would aid in determining the extent of the uranium-bearing material.

  16. Volatility of copper

    SciTech Connect

    Palmer, D.A.; Simonson, J.M.; Joyce, D.B.

    1996-08-01

    The relevant aqueous thermodynamics of copper and its oxides are evaluated and summarized with emphasis on solubility, hydrolysis, and complexation. The solubilities of metallic copper, solid cuprous and cupric oxides in steam measured by Pocock and Stewart in 1963 are discussed and the latter data are fitted in the form of established empirical equations and compared to other existing results. No other sources of data were found for the solubility of copper and cupric oxide in steam and even these data are very limited. Discussion of corresponding available solubility data on both oxide phases in liquid water is given. The possible effects of complexing agents are considered. A brief discussion is provided of the role of surface adsorption in determining the fate of dissolved copper in the boiler. 37 refs., 5 figs., 3 tabs.

  17. Metal sulfide initiators for metal oxide sorbent regeneration

    DOEpatents

    Turk, Brian S.; Gupta, Raghubir P.

    1999-01-01

    A process of regenerating a sulfided sorbent is provided. According to the process of the invention, a substantial portion of the energy necessary to initiate the regeneration reaction is provided by the combustion of a particulate metal sulfide additive. In using the particulate metal sulfide additive, the oxygen-containing gas used to regenerate the sulfided sorbent can be fed to the regeneration zone without heating or at a lower temperature than used in conventional processes wherein the regeneration reaction is initiated only by heating the oxygen-containing. The particulate metal sulfide additive is preferably an inexpensive mineral ore such as iron pyrite which does not adversely affect the regeneration or corresponding desulfurization reactions. The invention further includes a sorbent composition comprising the particulate metal sulfide additive in admixture with an active metal oxide sorbent capable of removing one or more sulfur compounds from a sulfur-containing gas stream.

  18. Metal sulfide initiators for metal oxide sorbent regeneration

    DOEpatents

    Turk, Brian S.; Gupta, Raghubir P.

    2001-01-01

    A process of regenerating a sulfided sorbent is provided. According to the process of the invention, a substantial portion of the energy necessary to initiate the regeneration reaction is provided by the combustion of a particulate metal sulfide additive. In using the particulate metal sulfide additive, the oxygen-containing gas used to regenerate the sulfided sorbent can be fed to the regeneration zone without heating or at a lower temperature than used in conventional processes wherein the regeneration reaction is initiated only by heating the oxygen-containing gas. The particulate metal sulfide additive is preferably an inexpensive mineral ore such as iron pyrite which does not adversely affect the regeneration or corresponding desulfurization reactions. The invention further includes a sorbent composition comprising the particulate metal sulfide additive in admixture with an active metal oxide sorbent capable of removing one or more sulfur compounds from a sulfur-containing gas stream.

  19. Microaeration for hydrogen sulfide removal in UASB reactor.

    PubMed

    Krayzelova, Lucie; Bartacek, Jan; Kolesarova, Nina; Jenicek, Pavel

    2014-11-01

    The removal of hydrogen sulfide from biogas by microaeration was studied in Up-flow Anaerobic Sludge Blanket (UASB) reactors treating synthetic brewery wastewater. A fully anaerobic UASB reactor served as a control while air was dosed into a microaerobic UASB reactor (UMSB). After a year of operation, sulfur balance was described in both reactors. In UASB, sulfur was mainly presented in the effluent as sulfide (49%) and in biogas as hydrogen sulfide (34%). In UMSB, 74% of sulfur was detected in the effluent (41% being sulfide and 33% being elemental sulfur), 10% accumulated in headspace as elemental sulfur and 9% escaped in biogas as hydrogen sulfide. The efficiency of hydrogen sulfide removal in UMSB was on average 73%. Microaeration did not cause any decrease in COD removal or methanogenic activity in UMSB and the elemental sulfur produced by microaeration did not accumulate in granular sludge. PMID:25270045

  20. Process for producing cadmium sulfide on a cadmium telluride surface

    DOEpatents

    Levi, D.H.; Nelson, A.J.; Ahrenkiel, R.K.

    1996-07-30

    A process is described for producing a layer of cadmium sulfide on a cadmium telluride surface to be employed in a photovoltaic device. The process comprises providing a cadmium telluride surface which is exposed to a hydrogen sulfide plasma at an exposure flow rate, an exposure time and an exposure temperature sufficient to permit reaction between the hydrogen sulfide and cadmium telluride to thereby form a cadmium sulfide layer on the cadmium telluride surface and accomplish passivation. In addition to passivation, a heterojunction at the interface of the cadmium sulfide and the cadmium telluride can be formed when the layer of cadmium sulfide formed on the cadmium telluride is of sufficient thickness. 12 figs.

  1. Metal sulfide initiators for metal oxide sorbent regeneration

    DOEpatents

    Turk, B.S.; Gupta, R.P.

    1999-06-22

    A process of regenerating a sulfided sorbent is provided. According to the process of the invention, a substantial portion of the energy necessary to initiate the regeneration reaction is provided by the combustion of a particulate metal sulfide additive. In using the particulate metal sulfide additive, the oxygen-containing gas used to regenerate the sulfided sorbent can be fed to the regeneration zone without heating or at a lower temperature than used in conventional processes wherein the regeneration reaction is initiated only by heating the oxygen-containing gas. The particulate metal sulfide additive is preferably an inexpensive mineral ore such as iron pyrite which does not adversely affect the regeneration or corresponding desulfurization reactions. The invention further includes a sorbent composition comprising the particulate metal sulfide additive in admixture with an active metal oxide sorbent capable of removing one or more sulfur compounds from a sulfur-containing gas stream. 1 fig.

  2. Gold Sulfide Nanoclusters: A Unique Core-in-cage Structure

    SciTech Connect

    Jiang, Deen; Walter, Michael; Dai, Sheng

    2010-01-01

    By using a DFT-based basin-hopping method, we found putative global minima for three gold sulfide nanoclusters, observed in mass spectrometry, that all show a symmetric core-in-cage structure: a metallic Au core inside a cage with S as vertices and Au at the edges. This core-in-cage structure is distinct from bulk gold sulfide. This work fills the knowledge gap regarding the structure of gold sulfide nanoclusters of {approx}1 nm.

  3. Invisible and microscopic gold in pyrite: Methods and new data for massive sulfide ores of the Urals

    NASA Astrophysics Data System (ADS)

    Vikentyev, I. V.

    2015-07-01

    particles was registered in the ores of these deposits by the methods of transmission electron microscopy. The low degree (or absence) of metamorphic recrystallization results in (1) predomination of thin intergrowths of sulfides, which is the main reason for the bad concentration of ores (especially for the Galkinsk deposit) and (2) the high portion of "invisible" gold in the massive sulfide ores, which explains the low yield of Au in copper and zinc concentrates, since it is lost in tailings with predominating pyrite.

  4. Limitation of Sulfide Capacity Concept for Molten Slags

    NASA Astrophysics Data System (ADS)

    Jung, In-Ho; Moosavi-Khoonsari, Elmira

    2016-04-01

    The sulfide capacity concept has been widely used in pyrometallurgy to define sulfur removal capacities of slags. Typically, the sulfide capacity is considered to be a unique slag property depending only on temperature regardless of partial pressures of oxygen and sulfur. In the present study, it is demonstrated that sulfide capacities of slags in particular those of Na2O-containing slags can vary with partial pressures of oxygen and sulfur due to large solubility of sulfide in Na2O-containing slag systems.

  5. Evidence supporting biologically mediated sulfide oxidation in hot spring ecosystems

    NASA Astrophysics Data System (ADS)

    Cox, A. D.; Shock, E.

    2011-12-01

    The sulfide concentration of fluids in hydrothermal ecosystems is one of several factors determining the transition to microbial photosynthesis (Cox et al., 2011, Chem. Geol. 280, 344-351). To investigate the loss of sulfide in Yellowstone hot spring systems, measurements of total dissolved sulfide with respect to time were made in incubation experiments conducted on 0.2-micron filtered (killed controls) vs. unfiltered hot spring water at locations with three different pH:sulfide combinations (pH 2.5 with 50 μM sulfide, 5.2 with 5.6 μM sulfide, and 8.3 with 86 μM sulfide). At the higher pH values, the experiments yielded similar rates of sulfide loss in filtered and unfiltered water of approximately 0.8 (pH 5.2) and 7.6 nmol sulfide L-1s-1 (pH 8.3). At the acidic spring, the unfiltered water lost sulfide at a rate 1.6 times that of the filtered water (8.2 vs. 5 nmol sulfide L-1s-1). These results suggest that the pelagic biomass at the pH 5.2 and 8.3 springs may not affect sulfide loss, whereas in the pH 2.5 spring there appears to be an effect. In addition, the incubation of filamentous biomass with unfiltered water increased the rate of sulfide loss by approximately two-fold at a pH of 2.5 (59 vs. 31 nmol L-1s-1; Cox et al., 2011), five-fold at a pH of 5.2 (3.9 vs. 0.8 nmol sulfide L-1s-1), and barely increased the rate of sulfide loss at a pH of 8.3 (9.1 vs. 8.4 nmol sulfide L-1s-1). Sulfide is predominately present as HS- at a pH of 8.3, which may not be taken up as easily by microorganisms as the H2S (aq) that dominates sulfide speciation at pH 2.5 and 5.2. That the loss of sulfide at acidic pH is due to biotic rather than abiotic factors is further supported by studies with whole mat samples that show greater sulfide consumption than killed controls (D'Imperio et al., 2008, AEM 74, 5802-5808). Taken together, the results of these experiments suggest that the majority of sulfide oxidation occurs in the filamentous biomass of hot spring ecosystems, although

  6. Green synthesis of covellite nanocrystals using biologically generated sulfide: potential for bioremediation systems.

    PubMed

    da Costa, J P; Girão, Ana Violeta; Lourenço, João P; Monteiro, O C; Trindade, Tito; Costa, Maria Clara

    2013-10-15

    This work describes the synthesis of CuS powders in high yield and via an environmentally friendly and straightforward process, under ambient conditions (temperature and pressure), by adding to aqueous copper (II) a nutrient solution containing biologically generated sulfide from sulfate-reducing bacteria (SRB). The powders obtained were composed of CuS (covellite) nanoparticles (NPs) exhibiting a spheroid morphology (<5 nm). The relevance of this method to obtain CuS supported solid substrates has been demonstrated by performing the synthesis in the presence of TiO2 and SiO2 submicron particles. We further extended the work carried out, which substantiates the potential of using biogenic sulfide for the production of covellite nanocrystals and composites, using the effluent of a bioremediation column. Hence, such process results in the synthesis of added value products obtained from metal rich effluents, such as metallurgical and industrial ones, or Acid Mine Drainage (AMD), when associated with bioremediation processes. PMID:23747373

  7. Discovery and Characterization of Iron Sulfide and Polyphosphate Bodies Coexisting in Archaeoglobus fulgidus Cells

    PubMed Central

    Toso, Daniel B.; Javed, Muhammad Mohsin; Czornyj, Elizabeth; Zhou, Z. Hong

    2016-01-01

    Inorganic storage granules have long been recognized in bacterial and eukaryotic cells but were only recently identified in archaeal cells. Here, we report the cellular organization and chemical compositions of storage granules in the Euryarchaeon, Archaeoglobus fulgidus strain VC16, a hyperthermophilic, anaerobic, and sulfate-reducing microorganism. Dense granules were apparent in A. fulgidus cells imaged by cryo electron microscopy (cryoEM) but not so by negative stain electron microscopy. Cryo electron tomography (cryoET) revealed that each cell contains one to several dense granules located near the cell membrane. Energy dispersive X-ray (EDX) spectroscopy and scanning transmission electron microscopy (STEM) show that, surprisingly, each cell contains not just one but often two types of granules with different elemental compositions. One type, named iron sulfide body (ISB), is composed mainly of the elements iron and sulfur plus copper; and the other one, called polyphosphate body (PPB), is composed of phosphorus and oxygen plus magnesium, calcium, and aluminum. PPBs are likely used for energy storage and/or metal sequestration/detoxification. ISBs could result from the reduction of sulfate to sulfide via anaerobic energy harvesting pathways and may be associated with energy and/or metal storage or detoxification. The exceptional ability of these archaeal cells to sequester different elements may have novel bioengineering applications. PMID:27194953

  8. Discovery and Characterization of Iron Sulfide and Polyphosphate Bodies Coexisting in Archaeoglobus fulgidus Cells

    DOE PAGESBeta

    Toso, Daniel B.; Javed, Muhammad Mohsin; Czornyj, Elizabeth; Gunsalus, Robert P.; Zhou, Z. Hong

    2016-01-01

    Inorganic storage granules have long been recognized in bacterial and eukaryotic cells but were only recently identified in archaeal cells. Here, we report the cellular organization and chemical compositions of storage granules in the Euryarchaeon , Archaeoglobus fulgidus strain VC16, a hyperthermophilic, anaerobic, and sulfate-reducing microorganism. Dense granules were apparent in A. fulgidus cells imaged by cryo electron microscopy (cryoEM) but not so by negative stain electron microscopy. Cryo electron tomography (cryoET) revealed that each cell contains one to several dense granules located near the cell membrane. Energy dispersive X-ray (EDX) spectroscopy and scanning transmission electron microscopy (STEM) showmore » that, surprisingly, each cell contains not just one but often two types of granules with different elemental compositions. One type, named iron sulfide body (ISB), is composed mainly of the elements iron and sulfur plus copper; and the other one, called polyphosphate body (PPB), is composed of phosphorus and oxygen plus magnesium, calcium, and aluminum. PPBs are likely used for energy storage and/or metal sequestration/detoxification. ISBs could result from the reduction of sulfate to sulfide via anaerobic energy harvesting pathways and may be associated with energy and/or metal storage or detoxification. The exceptional ability of these archaeal cells to sequester different elements may have novel bioengineering applications.« less

  9. Discovery and Characterization of Iron Sulfide and Polyphosphate Bodies Coexisting in Archaeoglobus fulgidus Cells.

    PubMed

    Toso, Daniel B; Javed, Muhammad Mohsin; Czornyj, Elizabeth; Gunsalus, Robert P; Zhou, Z Hong

    2016-01-01

    Inorganic storage granules have long been recognized in bacterial and eukaryotic cells but were only recently identified in archaeal cells. Here, we report the cellular organization and chemical compositions of storage granules in the Euryarchaeon, Archaeoglobus fulgidus strain VC16, a hyperthermophilic, anaerobic, and sulfate-reducing microorganism. Dense granules were apparent in A. fulgidus cells imaged by cryo electron microscopy (cryoEM) but not so by negative stain electron microscopy. Cryo electron tomography (cryoET) revealed that each cell contains one to several dense granules located near the cell membrane. Energy dispersive X-ray (EDX) spectroscopy and scanning transmission electron microscopy (STEM) show that, surprisingly, each cell contains not just one but often two types of granules with different elemental compositions. One type, named iron sulfide body (ISB), is composed mainly of the elements iron and sulfur plus copper; and the other one, called polyphosphate body (PPB), is composed of phosphorus and oxygen plus magnesium, calcium, and aluminum. PPBs are likely used for energy storage and/or metal sequestration/detoxification. ISBs could result from the reduction of sulfate to sulfide via anaerobic energy harvesting pathways and may be associated with energy and/or metal storage or detoxification. The exceptional ability of these archaeal cells to sequester different elements may have novel bioengineering applications. PMID:27194953

  10. The application of remote sensing in geobotanical exploration for metal sulfides

    NASA Technical Reports Server (NTRS)

    Masuoka, E. J.; Labovitz, M. L.; Bell, R.; Nelson, R. F.; Broderick, P. W.; Ludwig, R. W.

    1983-01-01

    A field study was conducted in Mineral, VA in 1980-82 to test the suitability of remote sensing techniques for geobotanical exploration. It was found that on trees growing over lead sulfide deposits, buds opened later and leaves were smaller than on trees growing on soils with background levels of lead and copper. This difference in leaf growth could be detected in remotely sensed data. In the spring, the smaller leaf size of metal-stressed trees resulted in a greater contribution from the soil and bark to the total reflectance imaged by the sensor. In the fall, the leaves of metal-stressed oaks sensed earlier than surrounding vegetation, which was also detected in remotely sensed data. It is concluded that vegetation growing on lead sulfide deposits has a shorter growing season than surrounding vegetation on unmineralized soil and that remotely sensed data collected at either end of the growing season can be used to locate geobotanical anomalies associated with these deposits.

  11. Scalable production of microbially mediated zinc sulfide nanoparticles and application to functional thin films.

    PubMed

    Moon, Ji-Won; Ivanov, Ilia N; Joshi, Pooran C; Armstrong, Beth L; Wang, Wei; Jung, Hyunsung; Rondinone, Adam J; Jellison, Gerald E; Meyer, Harry M; Jang, Gyoung Gug; Meisner, Roberta A; Duty, Chad E; Phelps, Tommy J

    2014-10-01

    A series of semiconducting zinc sulfide (ZnS) nanoparticles were scalably, reproducibly, controllably and economically synthesized with anaerobic metal-reducing Thermoanaerobacter species. These bacteria reduced partially oxidized sulfur sources to sulfides that extracellularly and thermodynamically incorporated with zinc ions to produce sparingly soluble ZnS nanoparticles with ∼5nm crystallites at yields of ∼5gl(-1)month(-1). A predominant sphalerite formation was facilitated by rapid precipitation kinetics, a low cation/anion ratio and a higher zinc concentration compared to background to produce a naturally occurring hexagonal form at the low temperature, and/or water adsorption in aqueous conditions. The sphalerite ZnS nanoparticles exhibited narrow size distribution, high emission intensity and few native defects. Scale-up and emission tunability using copper doping were confirmed spectroscopically. Surface characterization was determined using Fourier transform infrared and X-ray photoelectron spectroscopies, which confirmed amino acid as proteins and bacterial fermentation end products not only maintaining a nano-dimensional average crystallite size, but also increasing aggregation. The application of ZnS nanoparticle ink to a functional thin film was successfully tested for potential future applications. PMID:24932768

  12. Mitochondrial adaptations to utilize hydrogen sulfide for energy and signaling.

    PubMed

    Olson, Kenneth R

    2012-10-01

    Sulfur is a versatile molecule with oxidation states ranging from -2 to +6. From the beginning, sulfur has been inexorably entwined with the evolution of organisms. Reduced sulfur, prevalent in the prebiotic Earth and supplied from interstellar sources, was an integral component of early life as it could provide energy through oxidization, even in a weakly oxidizing environment, and it spontaneously reacted with iron to form iron-sulfur clusters that became the earliest biological catalysts and structural components of cells. The ability to cycle sulfur between reduced and oxidized states may have been key in the great endosymbiotic event that incorporated a sulfide-oxidizing α-protobacteria into a host sulfide-reducing Archea, resulting in the eukaryotic cell. As eukaryotes slowly adapted from a sulfidic and anoxic (euxinic) world to one that was highly oxidizing, numerous mechanisms developed to deal with increasing oxidants; namely, oxygen, and decreasing sulfide. Because there is rarely any reduced sulfur in the present-day environment, sulfur was historically ignored by biologists, except for an occasional report of sulfide toxicity. Twenty-five years ago, it became evident that the organisms in sulfide-rich environments could synthesize ATP from sulfide, 10 years later came the realization that animals might use sulfide as a signaling molecule, and only within the last 4 years did it become apparent that even mammals could derive energy from sulfide generated in the gastrointestinal tract. It has also become evident that, even in the present-day oxic environment, cells can exploit the redox chemistry of sulfide, most notably as a physiological transducer of oxygen availability. This review will examine how the legacy of sulfide metabolism has shaped natural selection and how some of these ancient biochemical pathways are still employed by modern-day eukaryotes. PMID:22430869

  13. Organic Sulfur Gas Production in Sulfidic Caves

    NASA Astrophysics Data System (ADS)

    Stern, L. A.; Engel, A. S.; Bennett, P. C.

    2001-12-01

    Lower Kane Cave, Big Horn Basin, WY, permits access to an environment where anaerobic sulfide-rich groundwater meets the aerobic vadose zone. At this interface microorganisms thrive on diverse metabolic pathways including autotrophic sulfur oxidation, sulfate reduction, and aerobic heterotrophy. Springs introduce groundwater rich in H2S to the cave where it both degasses into the cave atmosphere and is used by chemautotrophic sulfur oxidizing bacteria in the cave spring and stream habitat. The cave atmosphere in the immediate vicinity of the springs has elevated levels of CO2, H2S and methane, mirroring the higher concentration of H2S and methane in the spring water. The high CO2 concentrations are attenuated toward the two main sources of fresh air, the cave entrance and breathing holes at the rear of the cave. Conventional toxic gas monitors permit estimations of H2S concentrations, but they have severe cross sensitivity with other reduced sulfur gases, and thus are inadequate for characterization of sulfur cave gases. However employment of a field-based GC revealed elevated concentrations of carbonyl sulfide in cave atmosphere. Cultures of microorganisms collected from the cave optimized for enriching fermenters and autotrophic and heterophic sulfate reducing bacteria each produced carbonyl sulfide suggesting a biogenic in origin of the COS in addition to H2S. Enrichment cultures also produced methanethiol (methyl mercaptan) and an additional as yet undetermined volatile organic sulfur compound. In culture, the organo-sulfur compounds were less abundant than H2S, whereas in the cave atmosphere the organo-sulfur compounds were the dominant sulfur gases. Thus, these organo-sulfur gases may prove to be important sources of both reduced sulfur and organic carbon to microorganisms living on the cave wall in a subaerial habitat. Moreover groundwater has not yet been recognized as a source of sulfur gases to the atmosphere, but with the abundance of sulfidic

  14. High temperature regenerable hydrogen sulfide removal agents

    DOEpatents

    Copeland, Robert J.

    1993-01-01

    A system for high temperature desulfurization of coal-derived gases using regenerable sorbents. One sorbent is stannic oxide (tin oxide, SnO.sub.2), the other sorbent is a metal oxide or mixed metal oxide such as zinc ferrite (ZnFe.sub.2 O.sub.4). Certain otherwise undesirable by-products, including hydrogen sulfide (H.sub.2 S) and sulfur dioxide (SO.sub.2) are reused by the system, and elemental sulfur is produced in the regeneration reaction. A system for refabricating the sorbent pellets is also described.

  15. Bacterial Killing by Dry Metallic Copper Surfaces▿

    PubMed Central

    Santo, Christophe Espírito; Lam, Ee Wen; Elowsky, Christian G.; Quaranta, Davide; Domaille, Dylan W.; Chang, Christopher J.; Grass, Gregor

    2011-01-01

    Metallic copper surfaces rapidly and efficiently kill bacteria. Cells exposed to copper surfaces accumulated large amounts of copper ions, and this copper uptake was faster from dry copper than from moist copper. Cells suffered extensive membrane damage within minutes of exposure to dry copper. Further, cells removed from copper showed loss of cell integrity. Acute contact with metallic copper surfaces did not result in increased mutation rates or DNA lesions. These findings are important first steps for revealing the molecular sensitive targets in cells lethally challenged by exposure to copper surfaces and provide a scientific explanation for the use of copper surfaces as antimicrobial agents for supporting public hygiene. PMID:21148701

  16. The use of ERTS-1 images in the search for large sulfide deposits in the Chagai District, Pakistan

    NASA Technical Reports Server (NTRS)

    Schmidt, R. G. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. Visual examination of color composites was tested under relatively ideal conditions for direct detection of large hydrothermal sulfide deposits at the low-grade porphyry copper deposit at Saindak, western Chagai District, Pakistan. The Saindak deposit is characterized by an elongate zone of easily eroded sulfide-rich rock surrounded by a resistant rim of hornfels and propylitically altered rock. The geomorphic features related to the Saindak deposit are easily distinguished on ERTS-1 images. Attempts to detect a color anomaly using false-color composites were not successful. About 36,000 square km of the western Chagai District were examined on false-color composites for direct evidence of large sulfide deposits. New geologic information acquired from the images was used in conjunction with the known geology to evaluate two previously known proposed areas and to suggest seven additional targets for field checking, one of which is proposed on the basis of tonal anomaly alone. The study also showed that Saindak-type deposits are not likely to be present in some extensive areas of the Chagai District; and also that a rim like that at Saindak does not form if regional metamorphism has increased the resistance of the country rock to erosion.

  17. Separation of Molybdenum from Tungstate Solution—Scavenging Thiomolybdate by Copper Compound

    NASA Astrophysics Data System (ADS)

    Zhao, Zhongwei; Gao, Lili; Cao, Caifang; Li, Jiangtao; Chen, Xingyu; Chen, Ailiang; Liu, Xuheng; Sun, Peimei; Huo, Guangsheng; Li, Yunjiao; Li, Honggui

    2012-12-01

    Molybdenum is frequently associated with tungsten in mineral deposits, and their chemical properties are quite similar. Therefore, for many years, removal of impurity molybdenum from tungsten has been a worldwide technical problem. In this work, a separation process was investigated with the use of copper-bearing materials as the scavenging agents. Various conditions involved in the effects of different copper-bearing materials, dosage of scavenging agents, reaction time, and temperature were studied in detail. It was found that thiomolybdate can be selectively precipitated from tungstate solution by all the scavenging agents, especially when using nascent copper sulfide. Removal of thiomlybdate can reach 99.45 pct under optimum condition. Nascent CuS is an economic and efficient reagent for removing Mo from tungstate solution.

  18. Preparation of high purity copper fluoride by fluorinating copper hydroxyfluoride

    NASA Technical Reports Server (NTRS)

    King, R. B.; Lundquist, J. R.

    1969-01-01

    Copper fluoride containing no more than 50 ppm of any contaminating element was prepared by the fluorination of copper hydroxyfluoride. The impurity content was obtained by spark source mass spectrometry. High purity copper fluoride is needed as a cathode material for high energy density batteries.

  19. Copper and copper-nickel alloys as zebra mussel antifoulants

    SciTech Connect

    Dormon, J.M.; Cottrell, C.M.; Allen, D.G.; Ackerman, J.D.; Spelt, J.K.

    1996-04-01

    Copper has been used in the marine environment for decades as cladding on ships and pipes to prevent biofouling by marine mussels (Mytilus edulis L.). This motivated the present investigation into the possibility of using copper to prevent biofouling in freshwater by both zebra mussels and quagga mussels (Dreissena polymorpha and D. bugensis collectively referred to as zebra mussels). Copper and copper alloy sheet proved to be highly effective in preventing biofouling by zebra mussels over a three-year period. Further studies were conducted with copper and copper-nickel mesh (lattice of expanded metal) and screen (woven wire with a smaller hole size), which reduced the amount of copper used. Copper screen was also found to be strongly biofouling-resistant with respect to zebra mussels, while copper mesh reduced zebra mussel biofouling in comparison to controls, but did not prevent it entirely. Preliminary investigations into the mechanism of copper antifouling, using galvanic couples, indicated that the release of copper ions from the surface of the exposed metal into the surrounding water is directly or indirectly responsible for the biofouling resistance of copper.

  20. Geology of the Fishtie deposit, Central Province, Zambia: iron oxide and copper mineralization in Nguba Group metasedimentary rocks

    NASA Astrophysics Data System (ADS)

    Hendrickson, Michael D.; Hitzman, Murray W.; Wood, David; Humphrey, John D.; Wendlandt, Richard F.

    2015-08-01

    The Fishtie copper deposit, located in the Central Province of Zambia, contains approximately 55 Mt of 1.04 % Cu at a 0.5 % Cu cut-off in oxide, sulfide, and mixed oxide-sulfide ores. The deposit is hosted in Neoproterozoic diamictites and siltstones of the Grand Conglomérat Formation and overlying Kakontwe Limestone Formation of the lower Nguba Group. The Grand Conglomérat Formation at Fishtie directly overlies basement schists and quartzites. Mineralized zones are located adjacent to high-angle normal faults that appear to control thickness variations in the Grand Conglomérat Formation suggesting synsedimentary fault movement. Iron-rich rocks consisting of nearly monomineralic bands of magnetite and ankerite occur within the Grand Conglomérat Formation. The absence of magnetite-rich clasts in overlying diamictites and the presence of disseminated magnetite, ankerite, and apatite in adjacent diamictites suggest this iron-rich rock formed by replacement of siltstone beds. These magnetite-rich rocks thicken towards normal faults suggesting the faults formed conduits for oxidized hydrothermal solutions. The magnetite-ankerite-quartz rock was overprinted by later hydrothermal alteration and sulfide mineralization. Copper sulfide precipitation was associated with growth of both muscovite and chlorite, together with weak silicification. Sulfides are zoned relative to normal faults with bornite more common in proximity to faults and ore stage pyrite most common in an outer zone with chalcopyrite. Copper sulfides display generally heavy sulfur isotopic values, suggesting sulfide derivation from thermochemical reduction of Neoproterozoic seawater sulfate. Copper mineralized zones in the Grand Conglomérat at Fishtie are megascopically similar to those observed in the newly discovered Kamoa deposit in the southern Democratic Republic of Congo. Alteration and mineralization at Fishtie display lateral zoning relative to normal faults unlike the broad vertical zonation

  1. Ceruloplasmin, copper ions, and angiogenesis.

    PubMed

    Raju, K S; Alessandri, G; Ziche, M; Gullino, P M

    1982-11-01

    The ability to induce new formation of capillaries in the cornea was tested for ceruloplasmin, the copper carrier of serum, for fragments of the ceruloplasmin molecule with and without copper, for heparin, and for glycyl-L-histidyl-L-lysine, bound or not bound to copper ions. Male or female 2- to 3-kg New Zealand White rabbits were used. These experiments were prompted by the previous observation of copper accumulation in the cornea during angiogenesis and by the inability of copper-deficient rabbits to mount an angiogenic response. The results showed that the three different molecules were all able to induce angiogenesis provided that they were bound to copper. Fragments of the ceruloplasmin molecule also induced angiogenesis but only when copper was bound to the peptides. The data are interpreted to indicate that copper ions are involved in the sequence of events leading to angiogenesis and that the carrier molecules may be of quite a different nature. PMID:6182332

  2. 46 CFR 148.285 - Metal sulfide concentrates.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Metal sulfide concentrates. 148.285 Section 148.285... MATERIALS THAT REQUIRE SPECIAL HANDLING Special Requirements for Certain Materials § 148.285 Metal sulfide concentrates. (a) When information given by the shipper under § 148.60 of this part indicates that the...

  3. 46 CFR 148.285 - Metal sulfide concentrates.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Metal sulfide concentrates. 148.285 Section 148.285... MATERIALS THAT REQUIRE SPECIAL HANDLING Special Requirements for Certain Materials § 148.285 Metal sulfide concentrates. (a) When information given by the shipper under § 148.60 of this part indicates that the...

  4. Alternatives to Sulfide Dehairing: Use of Oxidative Agents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The dehairing of cattle hides with sodium sulfide generates large quantities of waste that are of environmental concern as they have a large biological and chemical oxygen demand. Additionally, sodium sulfide is a potential workplace hazard. We had worked with industry to develop a rapid dehairing...

  5. 46 CFR 148.285 - Metal sulfide concentrates.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Metal sulfide concentrates. 148.285 Section 148.285... concentrates. (a) When information given by the shipper under § 148.60 of this part indicates that the metal sulfide concentrate may generate toxic or flammable gases, the appropriate gas detection equipment...

  6. Normal state properties of the ternary molybdenum sulfides

    NASA Technical Reports Server (NTRS)

    Woollam, J. A.; Alterovitz, S. A.

    1978-01-01

    By making a large number of normal state and superconducting properties measurements, all on the same ternary molybdenum sulfide samples, we obtain values for Fermi surface and superconducting parameters. From these we conclude that sputtered ternary molybdenum sulfides are not completely in the dirty superconductor limit, and that they are d-band metals with a high electron carrier density.

  7. Formation of sulfide-calcite veinlets in the Kupferschiefer Cu-Ag deposits in Poland by natural hydrofracturing during basin subsidence

    SciTech Connect

    Jowett, E.C.

    1987-07-01

    Calcite and copper-(iron) sulfide veinlets in the Kupferschiefer ore deposits in southwestern Poland display many characteristics of antitaxial veinlets, including trails of wall-rock shards from wall to wall. Cross-cutting relationships demonstrate a change from sulfate to sulfide chemical stability and an evolution of stress orientation during ore-formation. Bedding-plane sulfate veinlets and later bedding-plane sulfide veinlets are superseded by vertical sulfide veinlets, suggesting tectonic extension during ore-formation. Thin bedding-plane calcite-(sulfide) veinlets record a return to pre-ore stress conditions after ore formation ceased. The vertical veinlets are thin and lens-shaped, typically 1-3 mm thick, 30-35 cm high, and 50-70 cm long, with orientations similar to Kimmerian-age (Triassic-Jurassic) directions. Sulfide replacement lenses cut across and are cut by vertical veinlets, suggesting contemporaneous formation after lithification. A mid-Triassic paleomagnetic age and cross-cutting Alpine-age faults and dikes suggest that the veinlets and other mineralization formed during rapid subsidence in the Triassic, and not during Alpine-age uplift. A genetic model is proposed whereby the fractures originated by natural hydrofracturing caused by (1) aquathermal pressuring and (2) generation of water, CO/sub 2/, and CH/sub 4/ from the coal organic matter in the Kupferschiefer, aided by over-pressured pore fluid. It is inferred that the mineralization was accompanied by natural-gas generation and by opening of the Tethys. 61 references.

  8. Influence of various surface pretreatments on adherence of sputtered molybdenum disulfide to silver, gold, copper, and bronze

    NASA Technical Reports Server (NTRS)

    Spalvins, T.

    1973-01-01

    Solid film lubricants of radio frequency sputtered molybdenum disulfide (MoS2) were applied to silver, gold, copper, and bronze surfaces that had various pretreatments (mechanical polishing, sputter etching, oxidation, and sulfurization). Optical and electron transmission micrographs and electron diffraction patterns were used to interpret the film formation characteristics and to evaluate the sputtering conditions in regard to the film and substrate compatibility. Sputtered MoS2 films flaked and peeled on silver, copper, and bronze surfaces except when the surfaces had been specially oxidized. The flaking and peeling was a result of sulfide compound formation and the corresponding grain growth of the sulfide film. Sputtered MoS2 films showed no peeling and flaking on gold surfaces regardless of surface pretreatment.

  9. Modification of the EIC hydrogen sulfide abatement process to produce valuable by-products. Final report, May 4, 1981-May 4, 1982

    SciTech Connect

    Offenhartz, P. O'D.

    1982-06-01

    A program of analytical and experimental studies has been carried out to develop modifications of the CUPROSUL process for the desulfurization of geothermal steam. The objective of the program was to devise practical means to manipulate the chemistry of the process so that the consumption of raw materials could be controlled and a variety of valuable by-products could be produced. The process had been demonstrated, at one-tenth commercial scale, for steam of the Geysers' average composition in a configuration which resulted in essentially complete oxidation of sulfide to sulfate. The ability to control the extent of oxidation would increase process flexibility and extend its range of applicability to steams of widely varying composition. Preliminary market surveys of raw materials required for the process and by-products which could be produced indicated that controlling the oxidation of sulfides to produce elemental sulfur would probably be the preferred process option. Use of lime to treat sulfate-containing purge streams to produce by-product gypsum and ammonia for recycle or sale could also be justified for certain steam compositions. Recovery of ammonium sulfate alone from the purge stream would not normally be justified unless corecovery of other valuable by-products, such as boric acid, was possible at incremental cost. It was found that ferric sulfate was a highly effective, selective oxidant for the controlled oxidation of copper sulfide solids to produce elemental sulfur for sale and copper sulfate for recycle.

  10. The Hydrolysis of Carbonyl Sulfide at Low Temperature: A Review

    PubMed Central

    Zhao, Shunzheng; Yi, Honghong; Tang, Xiaolong; Jiang, Shanxue; Gao, Fengyu; Zhang, Bowen; Zuo, Yanran; Wang, Zhixiang

    2013-01-01

    Catalytic hydrolysis technology of carbonyl sulfide (COS) at low temperature was reviewed, including the development of catalysts, reaction kinetics, and reaction mechanism of COS hydrolysis. It was indicated that the catalysts are mainly involved metal oxide and activated carbon. The active ingredients which can load on COS hydrolysis catalyst include alkali metal, alkaline earth metal, transition metal oxides, rare earth metal oxides, mixed metal oxides, and nanometal oxides. The catalytic hydrolysis of COS is a first-order reaction with respect to carbonyl sulfide, while the reaction order of water changes as the reaction conditions change. The controlling steps are also different because the reaction conditions such as concentration of carbonyl sulfide, reaction temperature, water-air ratio, and reaction atmosphere are different. The hydrolysis of carbonyl sulfide is base-catalyzed reaction, and the force of the base site has an important effect on the hydrolysis of carbonyl sulfide. PMID:23956697

  11. Physical and microstructural aspects of iron sulfide degradation in concrete

    SciTech Connect

    Schmidt, Thomas; Gallucci, Emanuel; Scrivener, Karen

    2011-03-15

    The microstructural aspects of iron sulfide degradation in dam concrete were investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) in both dam concrete samples and laboratory concrete. The results show that iron sulfide inclusions with a diameter of a few micrometers in the aggregates are reactive and appear to generate expansion first in the aggregates and consequently in the cement paste. The expansion from the iron sulfides is a consequence of the increase in volume of the reaction products formed. The types of iron sulfide present in the aggregate, mainly pyrrhotite (FeS) and pyrite (FeS{sub 2}), show similar reaction behavior in the aggregates. The released sulfate can lead to a secondary ettringite formation in the concrete matrix, but the degradation associated with this appears to be minor. The reaction of the iron sulfides was found to be very slow even when laboratory samples were exposed to elevated temperatures.

  12. Copper-phosphorus alloys offer advantages in brazing copper

    SciTech Connect

    Rupert, W.D.

    1996-05-01

    Copper-phosphorus brazing alloys are used extensively for joining copper, especially refrigeration and air-conditioning copper tubing and electrical conductors. What is the effect of phosphorus when alloyed with copper? The following are some of the major effects: (1) It lowers the melt temperature of copper (a temperature depressant). (2) It increases the fluidity of the copper when in the liquid state. (3) It acts as a deoxidant or a fluxing agent with copper. (4) It lowers the ductility of copper (embrittles). There is a misconception that silver improves the ductility of the copper-phosphorus alloys. In reality, silver added to copper acts in a similar manner as phosphorus. The addition of silver to copper lowers the melt temperature (temperature depressant) and decreases the ductility. Fortunately, the rate and amount at which silver lowers copper ductility is significantly less than that of phosphorus. Therefore, taking advantage of the temperature depressant property of silver, a Ag-Cu-P alloy can be selected at approximately the same melt temperature as a Cu-P alloy, but at a lower phosphorus content. The lowering of the phosphorus content actually makes the alloy more ductile, not the silver addition. A major advantage of the copper-phosphorus alloys is the self-fluxing characteristic when joining copper to copper. They may also be used with the addition of a paste flux on brass, bronze, and specialized applications on silver, tungsten and molybdenum. Whether it is selection of the proper BCuP alloy or troubleshooting an existing problem, the suggested approach is a review of the desired phosphorus content in the liquid metal and how it is being altered during application. In torch brazing, a slight change in the oxygen-fuel ratio can affect the joint quality or leak tightness.

  13. Removal of copper in an integrated sulfate reducing bioreactor-crystallization reactor system.

    PubMed

    Sierra-Alvarez, Reyes; Hollingsworth, Jeremy; Zhou, Michael S

    2007-02-15

    Removal of copper was investigated using an innovative water treatment system integrating a sulfidogenic bioreactor with a fluidized-bed crystallization reactor containing fine sand to facilitate the recovery of copper as a purified copper-sulfide mineral. The performance of the system was tested using a simulated semiconductor manufacturing wastewater containing high levels of Cu2+ (4-66 mg/L), sulfate, and a mixture of citrate, isopropanol, and polyethylene glycol (Mn 300). Soluble copper removal efficiencies exceeding 99% and effluent copper concentrations averaging 89 micog/L were demonstrated in the two-stage system, with near complete metal removal occurring in the crystallizer. Copper crystals deposited on sand grains were identified as covellite (CuS). The removal of organic constituents did not exceed 70% of the initial chemical oxygen demand due to incomplete degradation of isopropanol and its breakdown product (acetone). Taken as a whole, these results indicate the potential of this novel reactor configuration for the simultaneous removal of heavy metals and organic constituents. The ability of this process to recover heavy metals in a purified form makes it particularly attractive for the treatment of contaminated aqueous streams, including industrial wastewaters and acid mine drainage. PMID:17593752

  14. DGT-induced copper flux predicts bioaccumulation and toxicity to bivalves in sediments with varying properties.

    PubMed

    Simpson, Stuart L; Yverneau, Héloïse; Cremazy, Anne; Jarolimek, Chad V; Price, Helen L; Jolley, Dianne F

    2012-08-21

    Many regulatory frameworks for sediment quality assessment include consideration of contaminant bioavailability. However, the "snap-shots" of metal bioavailability provided by analyses of porewaters or acid-volatile sulfide-simultaneously extractable metal (AVS-SEM) relationships do not always contribute sufficient information. The use of inappropriate or inadequate information for assessing metal bioavailability in sediments may result in incorrect assessment decisions. The technique of diffusive gradients in thin films (DGT) enables the in situ measurement of metal concentrations in waters and fluxes from sediment porewaters. We utilized the DGT technique to interpret the bioavailability of copper to the benthic bivalve Tellina deltoidalis in sediments of varying properties contaminated with copper-based antifouling paint particles. For a concentration series of copper-paint contaminated sandy, silty-sand, and silty sediment types, DGT-probes were used to measure copper fluxes to the overlying water, at the sediment-water interface, and in deeper sediments. The overlying water copper concentrations and DGT-Cu fluxes were shown to provide excellent exposure concentration-response relationships in relation to lethal effects occurring to the copper-sensitive benthic bivalve, T. deltoidalis. The study demonstrates the strength of the DGT technique, which we expect will become frequently used for assessing metal bioavailability in sediments. PMID:22827499

  15. Understanding Cu release into environment from Kure massive sulfide ore deposits, Kastamonu, NW Turkey

    NASA Astrophysics Data System (ADS)

    Demirel, Cansu; Sonmez, Seref; Balci, Nurgul

    2014-05-01

    Covering a wide range on the earth's crust, oxidation of metal sulfide minerals have vital environmental impacts on the aquatic environment, causing one of the major environmental problems known as acid mine drainage (AMD). Located in the Kastamonu province of the Western Black Sea region, Kure district is one of the major copper mining sites in Turkey. Mining activities in the area heads back to ancient times, such that operation is thought to be started with the Roman Empire. Currently, only the underground mining tunnels of Bakibaba and Asikoy are being operated. Thus, mining heaps and ores of those pyritic deposits have been exposed to the oxidative conditions for so long. As a result of weathering processes of past and recent heaps of the Kure volcanic massive sulfide deposits in addition to the main ore mineral (chalcopyrite), significant amount of metals, especially Cu, are being released into the environment creating undesirable environmental conditions. In order to elucidate Cu release mechanisms from Kure pyritic ore deposits and mining wastes, field and laboratory approaches were used. Surface water and sediment samples from the streams around the mining and waste sites were collected. Groundwater samples from the active underground mining site were also collected. Physical parameters (pH, Eh, T°C, and EC) of water samples were determined in situ and in the laboratory using probes (WTW pH 3110, WTW Multi 9310 and CRISON CM 35). Metal and ion concentrations of the water samples were analysed using ICP-MS and DR 2800 spectrophotometer, respectively. High Cu, Co, Zn and Fe concentrations were determined in the water samples with pH values ranging from 2.9- 4. Cu concentrions ranges from 345 ppm to 36 ppm in the water samples. Consistent with the water samples, high Cu, Fe, Zn and Co were also determined in the sediment samples. Laboratory chalcopyrite oxidation experiments under the conditions representing the field site were set up as biological and

  16. High adherence copper plating process

    SciTech Connect

    Mignardot, H.

    1992-12-31

    A process is described for applying copper to a substrate of aluminum or steel by electrodeposition and for preparing an aluminum or steel substrate for electrodeposition of copper. Practice of the invention provides good adhesion of the copper layer to the substrate.

  17. SOURCES OF COPPER AIR EMISSIONS

    EPA Science Inventory

    The report gives results of a study to update estimates of atmospheric emissions of copper and copper compounds in the U.S. Source categories evaluated included: metallic minerals, primary copper smelters, iron and steel making, combustion, municipal incineration, secondary coppe...

  18. High adherence copper plating process

    DOEpatents

    Nignardot, H.

    1993-09-21

    A process is described for applying copper to a substrate of aluminum or steel by electrodeposition and for preparing the surface of an aluminum or steel substrate for the electrodeposition of copper. Practice of the invention provides good adhesion of the copper layer to either substrate.

  19. Lab Tracker and Copper Calculator

    MedlinePlus

    ... on the top of this page. Appendix: Recommended Target Result Ranges for Good Copper Control in Treated Wilson Disease Patients. 24 Hour Urine Copper On Chelators: 200 - 500µg (3 - 8µmoles)/day On Zinc: <75µg/day 24 Hour Urine Zinc >2.0mg/day Non-Ceruloplasmin in Bound (Free) Copper 5 - 15 µg/ ...

  20. DISSOLUTION OF PLUTONIUM CONTAINING CARRIER PRECIPITATE BY CARBONATE METATHESIS AND SEPARATION OF SULFIDE IMPURITIES THEREFROM BY SULFIDE PRECIPITATION

    DOEpatents

    Duffield, R.B.

    1959-07-14

    A process is described for recovering plutonium from foreign products wherein a carrier precipitate of lanthanum fluoride containing plutonium is obtained and includes the steps of dissolving the carrier precipitate in an alkali metal carbonate solution, adding a soluble sulfide, separating the sulfide precipitate, adding an alkali metal hydroxide, separating the resulting precipitate, washing, and dissolving in a strong acid.

  1. Erosion-corrosion performance of nickel-based and copper-based alloys in the Arabian Gulf seawater

    SciTech Connect

    Al-Hashem, A.; Carew, J.; Al-Sayegh, A.

    1996-10-01

    The erosion-corrosion behavior of nickel-based (UNS N0 6022) and copper-based (UNS C71500) alloy tubes in water flowing seawater containing sulfide ions is investigated. Visual, optical and scanning electron microscopy examinations of the internal surfaces of the tubes were conducted to compare the susceptibilities to erosion-corrosion attack of these two alloys, taking into consideration the nature of the product films formed.

  2. High-quality draft genome sequence of Kocuria marina SO9-6, an actinobacterium isolated from a copper mine

    PubMed Central

    Castro, Daniel B.A.; Pereira, Letícia Bianca; Silva, Marcus Vinícius M. e; Silva, Bárbara P. da; Palermo, Bruna Rafaella Z.; Carlos, Camila; Belgini, Daiane R.B.; Limache, Elmer Erasmo G.; Lacerda, Gileno V. Jr; Nery, Mariana B.P.; Gomes, Milene B.; Souza, Salatiel S. de; Silva, Thiago M. da; Rodrigues, Viviane D.; Paulino, Luciana C.; Vicentini, Renato; Ferraz, Lúcio F.C.; Ottoboni, Laura M.M.

    2015-01-01

    An actinobacterial strain, designated SO9-6, was isolated from a copper iron sulfide mineral. The organism is Gram-positive, facultatively anaerobic, and coccoid. Chemotaxonomic and phylogenetic properties were consistent with its classification in the genus Kocuria. Here, we report the first draft genome sequence of Kocuria marina SO9-6 under accession JROM00000000 (http://www.ncbi.nlm.nih.gov/nuccore/725823918), which provides insights for heavy metal bioremediation and production of compounds of biotechnological interest. PMID:26484219

  3. Predicting the Location of Extinct Massive Sulfide Deposits on the Atlantic Seafloor

    NASA Astrophysics Data System (ADS)

    Devey, C. W.; Jamieson, J. W.; Petersen, S.; Yeo, I. A.; Walter, M.; Buss, A.; Collins, J.; Koehler, J.; Palgan, D.; Vishiti, A.

    2013-12-01

    More than 25% of heat-loss from the Earth's interior occurs via hydrothermal cooling of newly-formed oceanic lithosphere at mid-ocean ridges. In the process, elements (including economically-relevant base and precious metals) are re-distributed and concentrated in seafloor massive sulphide (SMS) deposits. A recent estimate1 suggested that the amount of metal being deposited at the presently-active ridges is not economically significant (with a total copper+zinc inventory equal to only one year of global copper+zinc consumption), but also highlighted the unknown potential of older seafloor, for which no viable exploration models existed. Here we present the results of hydrothermal exploration along 3000 km of the Mid-Atlantic Ridge (representing almost 5% of the total length (64.000km) of the global mid-ocean ridge system and over 8% of the economically more interesting slow-spreading (<40mm/yr) ridges). We find significant correlations between axial morphology as determined by ship-mounted multibeam and the presence of high-temperature hydrothermal venting determined from water column studies. Using these relationships we can, for the first time, predict the location of extinct hydrothermal deposits within the plate interior solely based on ship-based multibeam surveys. 1 Hannington, M., Jamieson, J., Monecke, T., Petersen, S. & Beaulieu, S. The abundance of seafloor massive sulfide deposits. Geology 39, 1155-1158, doi:10.1130/G32468.1 (2011).

  4. Hydrothermal alteration and sulfide mineralization in gabbroids of the Markov Deep (Mid-Atlantic Ridge, 6° N)

    NASA Astrophysics Data System (ADS)

    Sharkov, E. V.; Abramov, S. S.; Simonov, V. A.; Krinov, D. I.; Skolotnev, S. G.; Bel'Tenev, V. E.; Bortnikov, N. S.

    2007-12-01

    A new type of sulfide occurrence related to metasomatically altered brecciated gabbroids has been studied at the Sierra Leone site situated in the axial rift valley of the Mid-Atlantic Ridge (Markov Deep, 6° N). Two associations of plutonic, subvolcanic, and volcanic rocks were dredged: (1) mid-ocean ridge basalts (MORB) and their intrusive analogues and (2) rocks of the silicic Fe-Ti-oxide series with dominating gabbronorites and sporadic trondhjemites. Almost all igneous rocks at the Sierra Leone site are enriched in Pb, Cu, U, Ga, Ta, Nb, Cs, and Rb and depleted in Zr, Th, and Hf. The rocks of the Fe-Ti-oxide series are enriched in Zn, Sn, and Mo and depleted in Ni and Cr. The main ore-bearing zone is situated at the foot of the eastern wall of the deep, where it is hosted in cataclastic hornblende gabbro and gabbronorite of the Fe-Ti-oxide series. Ore mineralization in metasomatically altered rocks is composed of quartz-sulfide and prehnite-sulfide veinlets, disseminated sulfide, and veined copper sulfide ore. The ore consists of pyrite, chalcopyrite, sphalerite, pyrrhotite, bornite, chalcocite, and digenite. The δ34S value of sulfides varies from 3.0 to 15.3‰. At the foot of the eastern wall of the Markov Deep, directly downslope from the ore-bearing zone, loose sediments contain grains of native Cu, Pb, Zn, and Sn and intermetallic compounds (isoferroplatinum, tetraferroplatinum, and brass) apparently derived from the ore. Mineral assemblages of ore-bearing metasomatic rocks and fluid inclusions therein were studied. Ore metasomatism developed under a low oxygen potential within a temperature interval from 400 to 160°C, though initial hydrothermal alteration of rocks proceeded at temperatures of 800-450°C. The temperature of stringer-disseminated ore mineralization is estimated at 170-280°C. The hydrothermal fluids are considered to be of magmatic origin; as the hydrothermal system evolved, they became diluted with seawater that was contained in

  5. Creative Copper Crests

    ERIC Educational Resources Information Center

    Knab, Thomas

    2011-01-01

    In this article, the author discusses how to create an art activity that would link the computer-created business cards of fourth-grade students with an upcoming school-wide medieval event. Creating family crests from copper foil would be a great connection, since they, like business cards, are an individual's way to identify themselves to others.…

  6. Copper leaching from chalcopyrite concentrates

    NASA Astrophysics Data System (ADS)

    Wang, Shijie

    2005-07-01

    Chalcopyrite (CuFeS2) is one of the most abundant copper-bearing minerals, which accounts for approximately 70 percent of the world’s known copper reserves. For more than 30 years, a significant number of processes have been developed to leach copper from chalcopyrite concentrates. These processes recover copper via hydrometallurgical leaching of the copper component of chalcopyrite concentrates, followed by solvent extraction and electrowinning. A number of demonstration plant operations have been conducted, but as of this writing none of the processes have become completely commercially operational.

  7. Precursors for formation of copper selenide, indium selenide, copper indium diselenide, and/or copper indium gallium diselenide films

    SciTech Connect

    Curtis, Calvin J; Miedaner, Alexander; Van Hest, Maikel; Ginley, David S

    2014-11-04

    Liquid-based precursors for formation of Copper Selenide, Indium Selenide, Copper Indium Diselenide, and/or copper Indium Galium Diselenide include copper-organoselenides, particulate copper selenide suspensions, copper selenide ethylene diamine in liquid solvent, nanoparticulate indium selenide suspensions, and indium selenide ethylene diamine coordination compounds in solvent. These liquid-based precursors can be deposited in liquid form onto substrates and treated by rapid thermal processing to form crystalline copper selenide and indium selenide films.

  8. An NIR-triggered and thermally responsive drug delivery platform through DNA/copper sulfide gates

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Li, Yecheng; Jin, Zexun; Yu, Jimmy C.; Chan, King Ming

    2015-07-01

    Nanomaterials for effective drug delivery require zero pre-release and on-demand release of therapeutic drugs. In this work we demonstrate a novel drug delivery system composed of a mesoporous silica platform conjugated to CuS nanoparticles with two complementary DNA sequences. CuS nanoparticles act as both gatekeepers preventing pre-release of drugs and photothermal agents for effective killing of cancer cells. This system exhibits temperature and NIR-responsive DOX release, with an additional accelerated release rate with GSH treatment. Therefore, it can act as an effective anticancer drug delivery carrier with triggered drug release and efficient anti-cancer effect in vitro after NIR irradiation.

  9. Green synthesis of wurtzite copper zinc tin sulfide nanocones for improved solar photovoltaic utilization

    NASA Astrophysics Data System (ADS)

    Arora, Leena; Gupta, Poonam; Chhikara, Nitu; Singh, Om Pal; Muhunthan, N.; Singh, V. N.; Singh, B. P.; Jain, Kiran; Chand, S.

    2015-02-01

    Cu2ZnSnS4 (CZTS) is considered to be one of the most promising light absorbing materials for low-cost and high-efficiency thin-film solar cells. It is composed of earth abundant, non-toxic elements. In the present study, wurtzite CZTS nanocone has been synthesized by a green chemistry route. The nanocones have been characterized for its optical, structural and microstructural properties using UV-Vis spectrophotometer, X-ray diffraction, Raman spectroscopy and high-resolution transmission electron microscopy. Optical absorption result shows a band gap of 1.42 eV. XRD and Raman results show wurtzite structure and TEM studies reveal the nanocone structure of the grown material. Growing vertically aligned nanocone structure having smaller diameter shall help in enhancing the light absorption in broader range which shall enhance the efficiency of solar cell. This study is a step in this direction.

  10. Sulfur incorporation into copper indium diselenide single crystals through annealing in hydrogen sulfide

    SciTech Connect

    Titus, Jochen; Birkmire, Robert W.; Hack, Christina; Mueller, Georg; McKeown, Patrick

    2006-02-15

    CuInSe{sub 2} crystals were sulfurized in a H{sub 2}S-Ar gas mixture at 575 deg. C. The focus was on the resulting mass transport, in particular, on the interdiffusion of Se and S. Experiments were done for various sulfurization times, and the resulting S distribution was measured by Auger electron spectroscopy sputter depth profiling and analyzed with the Boltzmann-Matano method. A one-dimensional diffusion process had shaped the S distribution in these crystals. The respective diffusion coefficient was on the order of 10{sup -16} cm{sup 2}/s, and it varied only slightly with the S content in CuIn(Se,S){sub 2}.

  11. Admittance spectroscopy of copper indium diselenide/cadmium sulfide solar cells

    NASA Astrophysics Data System (ADS)

    Strifler, Walter A.

    This dissertation concentrates on admittance spectroscopy of CuInSe2/CdS heterojunction solar cells prepared by chemical spray pyrolysis (CSP) and by multiple-source evaporation (MSE). The primary goal is to examine some of the more important electrical characteristics of these heterojunctions and determine if the spray-pyrolyzed cells behave similar, albeit at a lower efficiency, to higher quality cells prepared by other techniques. The primary analytical tool used in this study is admittance spectroscopy. The theory of admittance spectroscopy is developed using the concept of equivalent circuits. The traditional temperature-swept technique for admittance spectroscopy is shown to be inadequate for measuring most heterojunction samples examined in this study because of the large parallel leakage conductance found in these devices. Instead, a frequency-swept admittance technique is developed and employed to correct for the parallel conductance effect and reveal the true nature of slow charge in the depletion layer. In addition to admittance spectroscopy, the two sets of solar cell diodes are characterized using a variety of measurement techniques including capacitance-voltage, current-voltage over spectral response, capacitance dispersion over wavelength, and solar efficiency. The different pieces of experimental data are discussed to form a self-consistent physical model of the polycrystalline solar cells. Charge transport across the diode junction is dominated by recombination processes within the CuInSe2 depletion layer for both sets of diodes although the large parallel conductance in the CSP diodes often masks this characteristic. The CSP solar cells exhibit a pronounced blue peak in the spectral response indicating that electron collection is the limiting factor in the overall short-circuit quantum efficiency. A large degree of capacitance dispersion is found in both sets of diodes. Supporting measurements indicate that the majority of this dispersion is due to interface traps in the MSE diodes and bulk acceptor traps in the CSP diodes. The high density of bulk acceptor traps in the CuInSe2 are located approximately 0.30 eV above the valence band and exhibit a capture cross section of approximately 5 x 10(exp -18)/sq cm. The dissertation concludes with a summary of the important mechanisms that presently dominate the efficiency of the CuInSe2/CdS solar cells prepared by CSP.

  12. Highly Luminescent Heterostructured Copper-Doped Zinc Sulfide Nanocrystals for Application in Cancer Cell Labeling.

    PubMed

    Ang, Huixiang; Bosman, Michel; Thamankar, Ramesh; Zulkifli, Muhammad Faizal B; Yen, Swee Kuan; Hariharan, Anushya; Sudhaharan, Thankiah; Selvan, Subramanian Tamil

    2016-08-18

    The structural characteristics of the seed-mediated synthesis of heterostructured CuS-ZnS nanocrystals (NCs) and Cu-doped ZnS (ZnS:Cu) NCs synthesized by two different protocols are compared and analyzed. At high Cu dopant concentrations, segregated subclusters of ZnS and CuS are observed. The photoluminescence quantum yield of ZnS:Cu NCs is about 50-80 %; a value much higher than that of ZnS NCs (6 %). Finally, these NCs are coated with a thin silica shell by using (3-mercaptopropyl)triethoxysilane in a reverse microemulsion to make them water soluble. Cytotoxicity experiments show that these silica-coated NCs have greatly reduced toxicity on both cancerous HeLa and noncancerous Chinese hamster ovary cells. The labeling of cancerous HeLa cells is also demonstrated. PMID:27146419

  13. Phase-dependent photocatalytic H2 evolution of copper zinc tin sulfide under visible light.

    PubMed

    Chang, Zhi-Xian; Zhou, Wen-Hui; Kou, Dong-Xing; Zhou, Zheng-Ji; Wu, Si-Xin

    2014-10-28

    CZTS exhibited apparently phase-dependent photocatalytic H2 evolution under visible light. Possible factors for the phase-dependent photocatalytic activity of CZTS were discussed in detail. PMID:25205452

  14. Controlling surface defects of non-stoichiometric copper-indium-sulfide quantum dots.

    PubMed

    Park, Jae Chul; Nam, Yoon Sung

    2015-12-15

    Quantum dots (QDs) can be used for a wide range of practical applications including solar energy conversion, light-emitting display, bio-imaging, and sensing. However, toxic heavy metal elements of Pb- and Cd-based QDs cause potential environmental problems and limit their wide applicability. To overcome this limitation, CuInS2 (CIS) QDs, which have a bulk bandgap energy of 1.5eV and relatively high absorptivity, can be a good alternative. However the photoluminescence quantum yield (PLQY) of CIS QDs is too low for practical applications. Here we investigate the effects of experimental factors in the solution synthesis of CIS/ZnS QDs on intrinsic defects and surface defects from photoluminescence (PL) analysis. A heating-up method is used with dodecanethiol as a sulfur source, a ligand, and a medium. The Cu-to-In feeding ratio is changed to control the PL spectrum in the range of visible to near infrared (NIR) frequencies. The PLQY is increased above 40% in all of the ranges through ZnS shell passivation and additional process optimization (e.g., controlled cooling rate and additional feeding of In(3+) ion precursor). This work demonstrates the role of intrinsic defects in PL and the importance of suppressing the formation of the surface defects to increase the PLQY. PMID:26319334

  15. Growth Response of Halophila engelmanni Aschers. to Sulfide, Copper, and Organic Nitrogen in Marine Sediments 1

    PubMed Central

    Pulich, Warren M.

    1983-01-01

    Growth response of the seagrass Halophila engelmanni Aschers. was studied using defined culture techniques. When added to the rhizosphere, nutrient-seawater medium supported vigorous plant growth, if substantial Cu (10 times that in modified Hoagland solution) plus organic N were present. H2S up to 0.2 millimolar in the sediment was not inhibitory. A requirement for exogenous organic N, especially urea, is postulated for vigorous growth of Halophila. Images Fig. 2 Fig. 3 PMID:16662940

  16. Structural, optical, photoluminescence and antibacterial properties of copper-doped silver sulfide nanoparticles.

    PubMed

    Fakhri, Ali; Pourmand, Melika; Khakpour, Reza; Behrouz, Sajjad

    2015-08-01

    The Ag2S and Cu doped Ag2S nanoparticles were prepared by simple chemical co-precipitation method and characterized by XRD, SEM, EDX, TEM, PL and UV-vis spectra. The photocatalytic activity of Ag2S and Cu doped Ag2S nanoparticles were investigated with Ofloxacin antibiotic, which is part of the fluoroquinolone family. The morphological study indicated that the products were spherical shape in with diameter size of 30nm. The photocatalytic results demonstrated that the Cu doping increased the photocatalytic efficiency of Ag2S nanoparticles. The outcome of antibacterial experiment under visible light irradiation indicate that the Cu doped Ag2S nanoparticles represent increased antibacterial performance compared with un-doped Ag2S nanoparticles. PMID:26048527

  17. Cadmium sulfide/copper ternary heterojunction cell research. Final report, January 8, 1979-June 7, 1980

    SciTech Connect

    Fleming, D. L.

    1980-01-01

    Dual source, Se and CuInSe/sub 2/, coevaporation and flash evaporation of stoichiometric CuInSe/sub 2/ powder were investigated to develop a process of fabricating large area CdS/CuInSe/sub 2/ heterojunction solar cells. CuInSe/sub 2/ was seen to decompose upon evaporation, producing layered films in the dual source system. Annealing of these films and alternative dual sources have been considered. Single phase p type films have been produced but no devices have been made from such films. Flash evaporation circumvents the decomposition problem, and if one bakes the powder to obtain a small Cu excess as well as getting a Se excess in the film, p type CuInSe/sub 2/ films can be obtained. A 1% efficient device of 6 cm/sup 2/ area was made using a flash evaporated CuInSe/sub 2/ film. Annealing studies and measurements of spatial uniformity of this device are reported.

  18. Sulfide synthesis through copper-catalyzed C-S bond formation under biomolecule-compatible conditions.

    PubMed

    Zhang, Yonghong; Li, Yiming; Zhang, Xiaomei; Jiang, Xuefeng

    2015-01-18

    We report here an efficient and mild method for constructing C-S bonds. The reactions were carried out with Na2S2O3 as a sulfurating reagent, CuSO4 as a catalyst, and water as solvent without any surfactant. The products were achieved in moderate to excellent yields at room temperature under air. Notably, this reaction is compatible with various biomolecules including amino acids, oligosaccharides, nucleosides, proteins, and cell lysates. PMID:25435202

  19. High-yield room temperature route to copper sulfide hollow nanospheres and their electrochemical properties

    NASA Astrophysics Data System (ADS)

    Wang, Yiying; Li, Qing; Nie, Ming; Li, Xuelian; Li, Yuan; Zhong, Xiaolin

    2011-07-01

    CuS hollow nanospheres have been successfully synthesized in high yield by reacting anhydrous cupric sulfate (CuSO4·5H2O) with thioacetamide (TAA) in ethylene glycol (EG) with the assistance of cetyltrimethylammonium bromide (CTAB). The products were characterized systematically by XRD, EDX, FESEM, TEM and BET measurement and size analysis, CV, LSV and CP. FESEM and TEM images revealed that the as-prepared CuS hollow nanospheres had a mean diameter of about 500 nm with a hollow cavity of about 340 nm and shell thickness of about 80 nm. The spheres were constructed by numerous nanoflakes. The Brunauer-Emmett-Teller (BET) surface area of the as-synthesized products was measured to be 99.77 m2g - 1. The Barrett-Joyner-Halenda (BJH) model analysis showed that the as-prepared CuS materials had a main pore size distribution of around 25 nm. CV curves, LSV of CuS for oxygen electroreduction and CP curves showed that the as-prepared CuS nanospheres were potential candidates which can be used as cathode catalysts for the oxygen reduction reaction (ORR) in alkaline media.

  20. Chemical spray pyrolysis of copper indium diselenide/cadmium sulfide solar cells

    SciTech Connect

    Brown, B.J.

    1989-01-01

    This dissertation concentrates on Chemical Spray Pyrolysis (CSP) of CuInSe{sub 2} and CdS thin films and solar cells. The primary goal is to gain an understanding of the chemistry and physics of CSP, and apply this knowledge to the fabrication of CuInSe{sub 2}/CdS solar cells. It provide an extensive review of the literature on the properties of CuInSe{sub 2} an CdS produced by CSP and other techniques. The films are characterized by x-ray diffractometry, scanning electron microscopy, electron microprobe, van der Pauw-Hall measurements, and optical absorption spectroscopy, and the devices are characterized electrically in the dark and under illumination. A model for the chemical mechanisms involved in CSP of CdS an CuInSe{sub 2} thin films is developed which is used to point out similarities between the two systems and explain the correlation between spray solution pH and second phases in CuInSe{sub 2} thin films. Structural investigations show that the CuInSe{sub 2} films can be produced in either the ordered or disordered crystal structure, while different substrates radically change the morphology of the films. By taking into account the effect of second phases, the electrical and optical properties of the sprayed films agree with published results for CuInSe{sub 2} produced by other techniques. The properties of the sprayed CdS films in this work are shown to agree with those sprayed by others. The device properties of cells fabricated in both the backwall and reverse backwall configuration are compared with each other and related to the materials properties of the semiconductor layers. The highest efficiency cell employing sprayed CuInSe{sub 2} is reported; however, the efficiency of the cells still need improvement before becoming practical. The dissertation concludes with recommendations for increasing the efficiency of completely sprayed CuInSe{sub 2}/CdS solar cells.

  1. Combinatorial photothermal and immuno cancer therapy using chitosan-coated hollow copper sulfide nanoparticles.

    PubMed

    Guo, Liangran; Yan, Daisy D; Yang, Dongfang; Li, Yajuan; Wang, Xiaodong; Zalewski, Olivia; Yan, Bingfang; Lu, Wei

    2014-06-24

    Near-infrared light-responsive inorganic nanoparticles have been shown to enhance the efficacy of cancer photothermal ablation therapy. However, current nanoparticle-mediated photothermal ablation is more effective in treating local cancer at the primary site than metastatic cancer. Here, we report the design of a near-infrared light-induced transformative nanoparticle platform that combines photothermal ablation with immunotherapy. The design is based on chitosan-coated hollow CuS nanoparticles that assemble the immunoadjuvants oligodeoxynucleotides containing the cytosine-guanine (CpG) motifs. Interestingly, these structures break down after laser excitation, reassemble, and transform into polymer complexes that improve tumor retention of the immunotherapy. In this "photothermal immunotherapy" approach, photothermal ablation-induced tumor cell death reduces tumor growth and releases tumor antigens into the surrounding milieu, while the immunoadjuvants potentiate host antitumor immunity. Our results indicated that combined photothermal immunotherapy is more effective than either immunotherapy or photothermal therapy alone against primary treated and distant untreated tumors in a mouse breast cancer model. These hollow CuS nanoparticles are biodegradable and can be eliminated from the body after laser excitation. PMID:24801008

  2. Optical constants of silver and copper indium ternary sulfides from infrared reflectivity measurements

    NASA Astrophysics Data System (ADS)

    Gasanly, N. M.

    2016-03-01

    Infrared reflection spectra are obtained in the frequency range of 50-2000 cm-1 for AgIn5S8 and CuIn5S8 single crystals grown by Bridgman method. All four infrared-active modes are detected, which are in full agreement with the prediction of group-theoretical analysis. Spectral dependence of optical parameters; real and imaginary parts of the dielectric function, the function of energy losses, refractive index, absorption index and absorption coefficient were calculated from reflectivity experiments. The frequencies of transverse and longitudinal optical modes and oscillator strengths were also determined. The bands detected in IR spectra of studied crystals were assigned to various vibration types (valence and valence-deformation) on the basis of the symmetrized displacements of atoms obtained employing the Melvin projection operators.

  3. Combinatorial Photothermal and Immuno Cancer Therapy Using Chitosan-Coated Hollow Copper Sulfide Nanoparticles

    PubMed Central

    2015-01-01

    Near-infrared light-responsive inorganic nanoparticles have been shown to enhance the efficacy of cancer photothermal ablation therapy. However, current nanoparticle-mediated photothermal ablation is more effective in treating local cancer at the primary site than metastatic cancer. Here, we report the design of a near-infrared light-induced transformative nanoparticle platform that combines photothermal ablation with immunotherapy. The design is based on chitosan-coated hollow CuS nanoparticles that assemble the immunoadjuvants oligodeoxynucleotides containing the cytosine-guanine (CpG) motifs. Interestingly, these structures break down after laser excitation, reassemble, and transform into polymer complexes that improve tumor retention of the immunotherapy. In this “photothermal immunotherapy” approach, photothermal ablation-induced tumor cell death reduces tumor growth and releases tumor antigens into the surrounding milieu, while the immunoadjuvants potentiate host antitumor immunity. Our results indicated that combined photothermal immunotherapy is more effective than either immunotherapy or photothermal therapy alone against primary treated and distant untreated tumors in a mouse breast cancer model. These hollow CuS nanoparticles are biodegradable and can be eliminated from the body after laser excitation. PMID:24801008

  4. Hydrogen sulfide selectivity with carbonyl sulfide removal to less than PPM levels

    SciTech Connect

    Bacon, T.R.; Pearce, R.L.; Foster, W.R. Jr.

    1986-01-01

    Changes in market conditions and plant operating economics require examination of traditional processes and operating practices in gas treating applications for upgrading to more stringent standards of efficiency in order to remain competitive while returning a satisfactory operating profit margin to the company. Anticipated reduction in solvent usage, improvements in Claus sulfur recovery unit performance and lower energy costs induced Ashland's Catlettsburg refinery to convert its entire sulfur removal system from monoethanolamine to methyldiethanolamine. One of the seven product streams being treated required extremely low carbonyl sulfide specifications. When the initial converted operations evidenced a need to improve the carbonyl sulfide removal, GAS/SPEC Tech Service produced an innovative solution which allowed for efficient operation which still achieved these objectives.

  5. Atomic layer deposition of aluminum sulfide thin films using trimethylaluminum and hydrogen sulfide

    SciTech Connect

    Sinha, Soumyadeep; Sarkar, Shaibal K.; Mahuli, Neha

    2015-01-15

    Sequential exposures of trimethylaluminum and hydrogen sulfide are used to deposit aluminum sulfide thin films by atomic layer deposition (ALD) in the temperature ranging from 100 to 200 °C. Growth rate of 1.3 Å per ALD cycle is achieved by in-situ quartz crystal microbalance measurements. It is found that the growth rate per ALD cycle is highly dependent on the purging time between the two precursors. Increased purge time results in higher growth rate. Surface limited chemistry during each ALD half cycle is studied by in-situ Fourier transformed infrared vibration spectroscopy. Time of flight secondary ion-mass spectroscopy measurement is used to confirm elemental composition of the deposited films.

  6. Sulfide elimination by intermittent nitrate dosing in sewer sediments.

    PubMed

    Liu, Yanchen; Wu, Chen; Zhou, Xiaohong; Zhu, David Z; Shi, Hanchang

    2015-01-01

    The formation of hydrogen sulfide in biofilms and sediments in sewer systems can cause severe pipe corrosions and health hazards, and requires expensive programs for its prevention. The aim of this study is to propose a new control strategy and the optimal condition for sulfide elimination by intermittent nitrate dosing in sewer sediments. The study was carried out based on lab-scale experiments and batch tests using real sewer sediments. The intermittent nitrate dosing mode and the optimal control condition were investigated. The results indicated that the sulfide-intermittent-elimination strategy by nitrate dosing is advantageous for controlling sulfide accumulation in sewer sediment. The oxidation-reduction potential is a sensitive indicator parameter that can reflect the control effect and the minimum N/S (nitrate/sulfide) ratio with slight excess nitrate is necessary for optimal conditions of efficient sulfide control with lower carbon source loss. The optimal control condition is feasible for the sulfide elimination in sewer systems. PMID:25597685

  7. Stabilization of mercury-containing wastes using sulfide.

    PubMed

    Piao, Haishan; Bishop, Paul L

    2006-02-01

    This paper summarizes the findings of our studies on mercury stabilization using sulfide. Primary stabilization variables such as stabilization pH and sulfide/mercury molar ratio were tested. Mercury stabilization effectiveness was evaluated using the Toxicity Characteristic Leaching Procedure (TCLP) and the constant pH leaching tests. The influence of interfering ions on mercury immobilization was also tested. The experimental results indicate that the sulfide-induced treatment technology is an effective way to minimize mercury leaching. It was found that the most effective mercury stabilization occurs at pH 6 combined with a sulfide/mercury molar ratio of 1. The combined use of increased dosage of sulfide and ferrous ions ([S]/[Hg]=2 and [Fe]/[Hg]=3 at pH=6) can significantly reduce interferences by chloride and/or phosphate during sulfide-induced mercury immobilization. The sulfide-treated waste stabilization efficiency reached 98%, even with exposure of the wastes to high pH leachants. PMID:16099084

  8. Solubility of hydrogen sulfide in n-methylpyrrolidone

    SciTech Connect

    Yarym-Agaev, N.L.; Matvienko, V.G.; Povalyaeva, N.V.

    1980-01-01

    The solubility of hydrogen sulfide in N-methylpyrrolidone was investigated over wide ranges of temperature and pressure. The dynamic variant of the gravimetric method was used at hydrogen sulfide pressures equal to or below atmospheric, and the static variant at higher pressures. In the dynamic variant of the gravimetric method hydrogen sulfide is passed through a known amount of solvent until saturation is reached, and the amount of gas dissolved is found from the weight increase. This method is particularly convenient in studies of highly soluble gases when the solvent has a low vapor pressure. If the vapor pressure of the solvent exceeded this value a correction for entrainment of solvent vapor by undissolved gas was applied. The study showed that the solubility of hydrogen sulfide in N-methylpyrrolidone rose steeply with increase of pressure and decrease of temperature and that it can be used as an effective absorbent of hydrogen sulfide in highly sulfurous natural gas. Since the solubility of hydrogen sulfide under atmospheric pressure is fairly high even at elevated temperatures, effective regeneration of N-methylpyrrolidone is possible by a combination of heating and blowing with an inert gas or by application of vacuum for removal of the hydrogen sulfide.

  9. [Oxidation of sulfide minerals by Thiobacillus ferrooxidans].

    PubMed

    Malakhova, P T; Chebotarev, G M; Kovalenko, E V; Volkov, Iu A

    1981-01-01

    Samples of natural pyrites and sphalerites were subjected to the action of the mineral medium 9K with 1 g of Fe3+ per litre in the presence and in the absence of Thiobacillus ferrooxidans, and incubated at 28 degrees C under the stationary conditions for 30 days. The chemical composition of the solutions was studied after leaching as well as changes of the surfaces of monoliths. The deepest etching of surfaces with the formation of crusts and films of jarosite, limonite and goslarite occurs upon the combined action of bacteria and Fe3+ in regions of a fine-zonal structure enriched with an isomorphous arsenic admixture which are characterized by a defective weak structure. The pyrite and sphalerite from Charmitan with a higher arsenic and iron content were leached more than the pyrite and sphalerite from Kurgashincan. This was also corroborated by chemical analyses of leaching solutions and by monometric studies of crushed sulfide samples. PMID:7219212

  10. Dibenzyl Sulfide Metabolism by White Rot Fungi

    PubMed Central

    Van Hamme, Jonathan D.; Wong, Eddie T.; Dettman, Heather; Gray, Murray R.; Pickard, Michael A.

    2003-01-01

    Microbial metabolism of organosulfur compounds is of interest in the petroleum industry for in-field viscosity reduction and desulfurization. Here, dibenzyl sulfide (DBS) metabolism in white rot fungi was studied. Trametes trogii UAMH 8156, Trametes hirsuta UAMH 8165, Phanerochaete chrysosporium ATCC 24725, Trametes versicolor IFO 30340 (formerly Coriolus sp.), and Tyromyces palustris IFO 30339 all oxidized DBS to dibenzyl sulfoxide prior to oxidation to dibenzyl sulfone. The cytochrome P-450 inhibitor 1-aminobenzotriazole eliminated dibenzyl sulfoxide oxidation. Laccase activity (0.15 U/ml) was detected in the Trametes cultures, and concentrated culture supernatant and pure laccase catalyzed DBS oxidation to dibenzyl sulfoxide more efficiently in the presence of 2,2′-azinobis(3-ethylbenzthiazoline-6-sulfonate) (ABTS) than in its absence. These data suggest that the first oxidation step is catalyzed by extracellular enzymes but that subsequent metabolism is cytochrome P-450 mediated. PMID:12571066

  11. Bioextraction of cobalt from complex metal sulfides

    SciTech Connect

    Thompson, D.L.; Noah, K.S.; Wichlacz, P.L.; Torma, A.E.

    1993-01-01

    The present study has investigated the bioleachability of naturally occurring cobaltite and synthetic cobalt sulfides using 29 pedigree and wild type'' strains of Thiobacillus ferrooxidans. On the basis of a screening test, five strains of bacteria were selected for assessing the effects of leach parameters (pH, ferrous and ferric sulfates, ammonium sulfate, bipotassium hydrogen phosphate, and substrate concentrations) on cobalt extraction from Blackbird Mine ore and concentrate. The mechanisms of cobalt extraction were explained in terms of direct and indirect modes of bacterial activity, and the chemistry involved in these processes was identified. Using various size fractions of a high-grade cobaltite, the kinetic parameters of cobalt extraction were derived for the effect of specific surface area to be V[sub m] = 376 mg dm[sup [minus]3] h[sup [minus]1] and K 1.27 m[sup 2] g[sup [minus]1].

  12. Bioextraction of cobalt from complex metal sulfides

    SciTech Connect

    Thompson, D.L.; Noah, K.S.; Wichlacz, P.L.; Torma, A.E.

    1993-05-01

    The present study has investigated the bioleachability of naturally occurring cobaltite and synthetic cobalt sulfides using 29 pedigree and ``wild type`` strains of Thiobacillus ferrooxidans. On the basis of a screening test, five strains of bacteria were selected for assessing the effects of leach parameters (pH, ferrous and ferric sulfates, ammonium sulfate, bipotassium hydrogen phosphate, and substrate concentrations) on cobalt extraction from Blackbird Mine ore and concentrate. The mechanisms of cobalt extraction were explained in terms of direct and indirect modes of bacterial activity, and the chemistry involved in these processes was identified. Using various size fractions of a high-grade cobaltite, the kinetic parameters of cobalt extraction were derived for the effect of specific surface area to be V{sub m} = 376 mg dm{sup {minus}3} h{sup {minus}1} and K 1.27 m{sup 2} g{sup {minus}1}.

  13. Hydrogen sulfide and polysulfides as signaling molecules.

    PubMed

    Kimura, Hideo

    2015-01-01

    Hydrogen sulfide (H2S) is a familiar toxic gas that smells of rotten eggs. After the identification of endogenous H2S in the mammalian brain two decades ago, studies of this molecule uncovered physiological roles in processes such as neuromodulation, vascular tone regulation, cytoprotection against oxidative stress, angiogenesis, anti-inflammation, and oxygen sensing. Enzymes that produce H2S, such as cystathionine β-synthase, cystathionine γ-lyase, and 3-mercaptopyruvate sulfurtransferase have been studied intensively and well characterized. Polysulfides, which have a higher number of inner sulfur atoms than that in H2S, were recently identified as potential signaling molecules that can activate ion channels, transcription factors, and tumor suppressors with greater potency than that of H2S. This article focuses on our contribution to the discovery of these molecules and their metabolic pathways and mechanisms of action. PMID:25864468

  14. Hydrogen sulfide exposure in an adult male

    PubMed Central

    Doujaiji, Bassam; Al-Tawfiq, Jaffar A.

    2010-01-01

    Hydrogen sulfide (H2S) is responsible for many incidents of occupational toxic exposure, especially in the petroleum industry. The clinical effects of H2S depend on its concentration and the duration of exposure. H2S is immediately fatal when concentrations are over 500-1000 parts per million (ppm) but exposure to lower concentrations, such as 10-500 ppm, can cause various respiratory symptoms that range from rhinitis to acute respiratory failure. H2S may also affect multiple organs, causing temporary or permanent derangements in the nervous, cardiovascular, renal, hepatic, and hematological systems. We present a case of occupational exposure to H2S leading to multi-organ involvement, acute respiratory failure, organizing pneumonia, and shock resembling acute sepsis. The patient also developed mild obstructive and restrictive pulmonary disease and peripheral neuropathy. PMID:20103963

  15. Interactions among sulfide-oxidizing bacteria

    NASA Technical Reports Server (NTRS)

    Poplawski, R.

    1985-01-01

    The responses of different phototrophic bacteria in a competitive experimental system are studied, one in which primary factors such as H2S or light limited photometabolism. Two different types of bacteria shared one limited source of sulfide under specific conditions of light. The selection of a purple and a green sulfur bacteria and the cyanobacterium was based on their physiological similarity and also on the fact that they occur together in microbial mats. They all share anoxygenic photosynthesis, and are thus probably part of an evolutionary continuum of phototrophic organisms that runs from, strictly anaerobic physiology to the ability of some cyanobacteria to shift between anoxygenic bacterial style photosynthesis and the oxygenic kind typical of eukaryotes.

  16. Structure of 4-methylpyridinium Hydrogen Sulfide

    NASA Technical Reports Server (NTRS)

    Andras, Maria T.; Hepp, Aloysius F.; Fanwick, Phillip E.; Martuch, Robert A.; Duraj, Stan A.; Gordon, Edward M.

    1994-01-01

    4-Methylpyridinium hydrogen sulfide, (C6H7NH)HS, M(sub r) = 127.21, consists of C6H7NH(+) cations and HS(-) anions. Z = 2 for the crystal with monoclinic space group Cm (#8), dimensions of a = 8.679(2) A, b = 7.964(1) A, and c = 4.860(2) A, an angle beta of 101.10(2) degrees, and a volume of V = 329.6(3) A(exp 3). R = 0.039 and R(sub w) = 0.048 for 385 reflections with F(sub o)(exp 2) greater than 3 sigma(F(sub o)(exp 2)) and 59 variables. Both the C6H7NH(+) cation and the HS(-) anion lie on crystallographic mirror planes with the N,S, two carbon atoms, and two hydrogen atoms positioned in the planes. The hydrogen atom of the HS(-) anion was not located.

  17. Atmospheric carbonyl sulfide exchange in bog microcosms

    SciTech Connect

    Fried, A.; Klinger, L.F.; Erickson, D.J. III )

    1993-01-22

    Measurements of Carbonyl sulfide (OCS) fluxes were carried out on bog microcosms using chamber sampling and tunable diode laser analysis. Intact bog microcosms (vascular plants, mosses, and peat) removed ambient levels of OCS in the light and dark with rates from [minus]2.4 to [minus]8.1 ng S min[sup [minus]1] m[sup [minus]2]. Peat and peat plus mosses emitted OCS in the light with rates of 17.4 and 10.9 ng S min[sup [minus]1] m[sup [minus]2], respectively. In the dark, the mosses apparently removed OCS at a rate equivalent to the peat emissions. A 3-D numerical tracer model using this data indicated that boreal bog ecosystems remove at most 1% of ambient OCS, not sufficient to account for an observed OCS depletion in boreal air masses. 13 refs., 1 fig., 1 tab.

  18. Hydrogen sulfide and polysulfides as signaling molecules

    PubMed Central

    KIMURA, Hideo

    2015-01-01

    Hydrogen sulfide (H2S) is a familiar toxic gas that smells of rotten eggs. After the identification of endogenous H2S in the mammalian brain two decades ago, studies of this molecule uncovered physiological roles in processes such as neuromodulation, vascular tone regulation, cytoprotection against oxidative stress, angiogenesis, anti-inflammation, and oxygen sensing. Enzymes that produce H2S, such as cystathionine β-synthase, cystathionine γ-lyase, and 3-mercaptopyruvate sulfurtransferase have been studied intensively and well characterized. Polysulfides, which have a higher number of inner sulfur atoms than that in H2S, were recently identified as potential signaling molecules that can activate ion channels, transcription factors, and tumor suppressors with greater potency than that of H2S. This article focuses on our contribution to the discovery of these molecules and their metabolic pathways and mechanisms of action. PMID:25864468

  19. Chemical Foundations of Hydrogen Sulfide Biology

    PubMed Central

    Li, Qian; Lancaster, Jack R.

    2013-01-01

    Following nitric oxide (nitrogen monoxide) and carbon monoxide, hydrogen sulfide (or its newer systematic name sulfane, H2S) became the third small molecule that can be both toxic and beneficial depending on the concentration. In spite of its impressive therapeutic potential, the underlying mechanisms for its beneficial effects remain unclear. Any novel mechanism has to obey fundamental chemical principles. H2S chemistry was studied long before its biological relevance was discovered, however, with a few exceptions, these past works have received relatively little attention in the path of exploring the mechanistic conundrum of H2S biological functions. This review calls attention to the basic physical and chemical properties of H2S, focuses on the chemistry between H2S and its three potential biological targets: oxidants, metals and thiol derivatives, discusses the applications of these basics into H2S biology and methodology, and introduces the standard terminology to this youthful field. PMID:23850631

  20. Chemical foundations of hydrogen sulfide biology.

    PubMed

    Li, Qian; Lancaster, Jack R

    2013-11-30

    Following nitric oxide (nitrogen monoxide) and carbon monoxide, hydrogen sulfide (or its newer systematic name sulfane, H2S) became the third small molecule that can be both toxic and beneficial depending on the concentration. In spite of its impressive therapeutic potential, the underlying mechanisms for its beneficial effects remain unclear. Any novel mechanism has to obey fundamental chemical principles. H2S chemistry was studied long before its biological relevance was discovered, however, with a few exceptions, these past works have received relatively little attention in the path of exploring the mechanistic conundrum of H2S biological functions. This review calls attention to the basic physical and chemical properties of H2S, focuses on the chemistry between H2S and its three potential biological targets: oxidants, metals and thiol derivatives, discusses the applications of these basics into H2S biology and methodology, and introduces the standard terminology to this youthful field. PMID:23850631

  1. Lanthanum sulfides as high temperature thermoelectric materials

    NASA Technical Reports Server (NTRS)

    Danielson, L. R.; Matsuda, S.; Raag, V.

    1984-01-01

    Thermoelectric property measurements have been made for the nonstoichiometric lanthanum sulfides, LaS(R) with R in the range 1.33-1.50. The Seebeck coefficients and electrical resistivities increase with temperature from 200 to 1100 C. Power factors (defined as Seebeck coefficient squared divided by electrical resistivity) generally increase both as the temperature is increased and as the compound composition is varied from LaS(1.48) to LaS(1.35). The power factor values combined with estimates of thermal conductivities for LaS(1.38) and LaS(1.4) yield figures of merit greater than 0.0005 at 1000 C.

  2. MODIFICATION OF METHODS 9030 AND 9031 FOR THE ANALYSIS OF SULFIDE BY SPECIFIC ION ELECTRODE

    EPA Science Inventory

    Two OSW SW-846 methods (Method 9030 and 9031) used for the determination of sulfide have been modified to include the use of sulfide specific ion electrodes (SIE). urrently in both methods sulfide is converted to hydrogen sulfide and distilled into a scrubber solution for subsequ...

  3. Optimization of the superconducting phase of hydrogen sulfide

    SciTech Connect

    Degtyarenko, N. N.; Masur, E. A.

    2015-12-15

    The electron and phonon spectra, as well as the densities of electron and phonon states of the SH{sub 3} phase and the stable orthorhombic structure of hydrogen sulfide SH{sub 2}, are calculated for the pressure interval 100–225 GPa. It is found that the I4/mmm phase can be responsible for the superconducting properties of metallic hydrogen sulfide along with the SH{sub 3} phase. Sequential stages for obtaining and conservation of the SH{sub 2} phase are proposed. The properties of two (SH{sub 2} and SH{sub 3}) superconducting phases of hydrogen sulfide are compared.

  4. Hydrogen and sulfur recovery from hydrogen sulfide wastes

    DOEpatents

    Harkness, John B. L.; Gorski, Anthony J.; Daniels, Edward J.

    1993-01-01

    A process for generating hydrogen and elemental sulfur from hydrogen sulfide waste in which the hydrogen sulfide is associated under plasma conditions and a portion of the hydrogen output is used in a catalytic reduction unit to convert sulfur-containing impurities to hydrogen sulfide for recycle, the process also including the addition of an ionizing gas such as argon to initiate the plasma reaction at lower energy, a preheater for the input to the reactor and an internal adjustable choke in the reactor for enhanced coupling with the microwave energy input.

  5. Hydrogen and sulfur recovery from hydrogen sulfide wastes

    DOEpatents

    Harkness, J.B.L.; Gorski, A.J.; Daniels, E.J.

    1993-05-18

    A process is described for generating hydrogen and elemental sulfur from hydrogen sulfide waste in which the hydrogen sulfide is [dis]associated under plasma conditions and a portion of the hydrogen output is used in a catalytic reduction unit to convert sulfur-containing impurities to hydrogen sulfide for recycle, the process also including the addition of an ionizing gas such as argon to initiate the plasma reaction at lower energy, a preheater for the input to the reactor and an internal adjustable choke in the reactor for enhanced coupling with the microwave energy input.

  6. Use of sulfide-containing liquors for removing mercury from flue gases

    DOEpatents

    Nolan, Paul S.; Downs, William; Bailey, Ralph T.; Vecci, Stanley J.

    2003-01-01

    A method and apparatus for reducing and removing mercury in industrial gases, such as a flue gas, produced by the combustion of fossil fuels, such as coal, adds sulfide ions to the flue gas as it passes through a scrubber. Ideally, the source of these sulfide ions may include at least one of: sulfidic waste water, kraft caustic liquor, kraft carbonate liquor, potassium sulfide, sodium sulfide, and thioacetamide. The sulfide ion source is introduced into the scrubbing liquor as an aqueous sulfide species. The scrubber may be either a wet or dry scrubber for flue gas desulfurization systems.

  7. Use of sulfide-containing liquors for removing mercury from flue gases

    DOEpatents

    Nolan, Paul S.; Downs, William; Bailey, Ralph T.; Vecci, Stanley J.

    2006-05-02

    A method and apparatus for reducing and removing mercury in industrial gases, such as a flue gas, produced by the combustion of fossil fuels, such as coal, adds sulfide ions to the flue gas as it passes through a scrubber. Ideally, the source of these sulfide ions may include at least one of: sulfidic waste water, kraft caustic liquor, kraft carbonate liquor, potassium sulfide, sodium sulfide, and thioacetamide. The sulfide ion source is introduced into the scrubbing liquor as an aqueous sulfide species. The scrubber may be either a wet or dry scrubber for flue gas desulfurization systems.

  8. Incorporating bioavailability into management limits for copper in sediments contaminated by antifouling paint used in aquaculture.

    PubMed

    Simpson, Stuart L; Spadaro, David A; O'Brien, Dom

    2013-11-01

    Although now well embedded within many risk-based sediment quality guideline (SQG) frameworks, contaminant bioavailability is still often overlooked in assessment and management of contaminated sediments. To optimise management limits for metal contaminated sediments, we assess the appropriateness of a range methods for modifying SQGs based on bioavailability considerations. The impairment of reproduction of the amphipod, Melita plumulosa, and harpacticoid copepod, Nitocra spinipes, was assessed for sediments contaminated with copper from antifouling paint, located below aquaculture cages. The measurement of dilute acid-extractable copper (AE-Cu) was found to provide the most useful means for monitoring the risks posed by sediment copper and setting management limits. Acid-volatile sulfide was found to be ineffective as a SQG-modifying factor as these organisms live mostly at the more oxidised sediment water interface. SQGs normalised to %-silt/organic carbon were effective, but the benefits gained were too small to justify this approach. The effectiveness of SQGs based on AE-Cu was attributed to a small portion of the total copper being present in potentially bioavailable forms (typically<10% of the total). Much of the non-bioavailable form of copper was likely present as paint flakes in the form of copper (I) oxide, the active ingredient of the antifoulant formulation. While the concentrations of paint-associated copper are very high in some sediments, as the transformation of this form of copper to AE-Cu appears slow, monitoring and management limits should assess the more bioavailable AE-Cu forms, and further efforts be made to limit the release of paint particles into the environment. PMID:24080008

  9. Micro-aeration for hydrogen sulfide removal from biogas

    NASA Astrophysics Data System (ADS)

    Duangmanee, Thanapong

    The presence of sulfur compounds (e.g. protein, sulfate, thiosulfate, sulfite, etc.) in the feed stream generates highly corrosive and odorous hydrogen sulfide during anaerobic digestion. The high sulfide level in the biogas stream is not only poisonous to many novel metal catalysts employed in thermo-catalytic processes but also reduces the quality of methane to produce renewable energy. This study used an innovative, low-maintenance, low-cost biological sulfide removal technology to remove sulfides simultaneously from both gas and liquid phase. ORP (Oxidation-Reduction-Potential) was used as the controlling parameter to precisely regulate air injection to the sulfide oxidizing unit (SOU). The microaeration technique provided just enough oxygen to partially oxidize sulfides to elemental sulfur without inhibiting methanogenesis. The SOU was equipped with a diffuser at the bottom for the dispersion of sulfide-laden biogas and injected air throughout the column. The SOU can be operated as a standalone unit or coupled with an anaerobic digester to simultaneously remove sulfide from the biogas and effluent. The integrated system was capable of reducing hydrogen sulfide in biogas from 2,450 to less than 2 ppmV with minimal sulfate production at the highest available sulfide loading rate of 0.24 kg/m3-day. More than 98% of sulfide removed was recovered as elemental sulfur. However, the standalone SOU was able to operate at high hydrogen sulfide loading of 1.46 kg/m 3-day at inlet sulfide concentration of 3000 ppmV and reduce the off-gas hydrogen sulfide concentrations to less than 10 ppmV. The experiment also revealed that the ORP controlled aeration was sensitive enough to prevent oxygen overdosing (dampening effect) during unexpected surges of aeration. Using generalized linear regression, a model predicting output H2S concentration based on input H2S concentrations, SOU medium heights, and biogas flow rates, was derived. With 95% confidence, output H2S concentration

  10. Enhanced Mantle Conductivity from Sulfides beneath the Sierra Nevada?

    NASA Astrophysics Data System (ADS)

    Park, S. K.

    2002-12-01

    A region of enhanced mantle conductivity (0.03-0.1 S/m) beneath the southern Sierra Nevada, where elevations of over 4000 m are found, has been attributed previously to 3-5% basaltic melt (Park et al., 1996) and to a mix of basaltic and sulfide melt (Ducea and Park, 2000). Because the sulfide melt is assumed to have similar conductivities to its solid counterpart (10,000 S/m), very small amounts (< 0.1%) of sulfide are needed in order to reduce the bulk conductivity from matrix values of about 0.003 S/m or even that of the matrix-basalt melt mix to the values observed. Basaltic melt percentages of less than 1% are needed in the presence of ~0.1% sulfide melt in order to match the observed mantle values. Xenoliths from the Holocene basalts in the Big Pine Volcanic Field contain 0.06-0.4% sulfide, so the estimated values are reasonable. Given the lack of evidence for volumetrically extensive, young (< 10 Ma) basaltic volcanism, calculated residence times of approximately 100 Ka for 3-5% partial melt, the short (about 300 Ka) times needed to develop connected pathways for the basalt, and the young extension of the adjacent Basin and Range province, a mixed melt with both basalt and sulfides seems more reasonable. This conclusion presupposes that the sulfide melt is somehow interconnected in the mantle. Models in which the matrix, the basaltic melt, and the sulfide melt each form interconnected, interlaced networks leads to much higher predictions of mantle conductivity; the sulfide melt fraction must be discontinuous in order to lower bulk conductivity. Petrological studies of sulfide-silicate systems confirm this conclusion; sulfide melts form isolated blebs on the surfaces of olivine within interconnected basaltic melt channels (Holzheid et al., 2000). Simple series-parallel models of ~1% continuous basaltic melt and ~0.01% discontinuous sulfide melt provide bulk conductivities comparable to the observed mantle values. More complicated equivalent media and Hashin

  11. Production of ultrahigh purity copper using waste copper nitrate solution.

    PubMed

    Choi, J Y; Kim, D S

    2003-04-25

    The production of ultrahigh purity copper (99.9999%) by electrolysis in the presence of a cementation barrier has been attempted employing a waste nitric copper etching solution as the electrolyte. The amount of copper deposited on the cathode increased almost linearly with electrolysis time and the purity of copper was observed to increase as the electrolyte concentration was increased. At some point, however, as the electrolyte concentration increased, the purity of copper decreased slightly. As the total surface area of cementation barrier increased, the purity of product increased. The electrolyte temperature should be maintained below 35 degrees C in the range of investigated electrolysis conditions to obtain the ultrahigh purity copper. Considering that several industrial waste solutions contain valuable metallic components the result of present study may support a claim that electrowinning is a very desirable process for their treatment and recovery. PMID:12719148

  12. Sorption of cadmium, copper, and zinc onto soft coal and the fungus Rhizopus javanicus

    SciTech Connect

    Watts, H.D.; Chapman, S.K.

    1993-12-31

    Experiments involved testing the sorption properties of soft coal and the fungus Rhizopus javanicus to evaluate the feasibility of using these materials for acid mine reclamation. The metals cadmium, copper, and zinc were chosen since they are generally present in sulfide mine waste and are toxic. Their toxicity warrants their removal. To appropriate sulfide mine conditions, solutions of individual metals were prepared with concentrations between five and fifty milligrams/Liter and pH levels between three and seven. Results show forty to seventy percent metal removal for the fungus, and seventy-five to one-hundred percent removal by the coal. The pH of all the metal solutions equilibrated to between four and six when the fungus was used, and between five and seven for the coal. Sorption kinetics studies are currently underway and will be reported.

  13. Intermetallic compounds, copper and palladium alloys in Au-Pd ore of the Skaergaard pluton, Greenland

    NASA Astrophysics Data System (ADS)

    Rudashevsky, N. S.; Rudashevsky, V. N.; Nielsen, T. F. D.

    2015-12-01

    Copper-palladium intermetallic compounds and alloys (2314 grains) from the Au-Pd ore of the Skaergaard layered gabbroic pluton have been studied. Skaergaardite PdCu, nielsenite PdCu3, (Cu,Pd)β, (Cu,Pd)α, (Pd,Cu,Au,Pt) alloys, and native palladium have been identified as a result of 1680 microprobe analyses. The average compositions and various chemical varieties of these minerals are characterized, as well as vertical and lateral zoning in distribution of noble metals. The primary Pd-Cu alloys were formed within a wide temperature interval broadly synchronously with cooling and crystallization of host gabbro and in close association with separation of Fe-Cu sulfide liquid. In the course of crystallization of residual gabbroic melt enriched in iron, noble and heavy metals and saturated with the supercritical aqueous fluid, PGE and Au are selectively concentrated in the Fe-Cu sulfide phase as Pd-Cu and Cu-Au alloys.

  14. Catalytic reduction of CO with hydrogen sulfide. 4. Temperature-programmed desorption of methanethiol on anatase, rutile, and sulfided rutile

    SciTech Connect

    Beck, D.D.; White, J.M.; Ratcliffe, C.T.

    1986-07-03

    The interaction of methanethiol with anatase, rutile, and sulfided rutile was studied by temperature-programmed desorption. Dissociative adsorption occurs on rutile but is insignificant on anatase. Decomposition products are dominated by H/sub 2/ on rutile and by CH/sub 4/ on sulfided rutile. In both cases desorption occurs between 500 and 775 K. The 5- and 4-coordinate sites on the (110) face of rutile are proposed as the active sites for decomposition. The dominance of methane on a sulfided surface is attributed to the relatively large supply of highly mobile surface hydrogen atoms.

  15. Type Zero Copper Proteins

    PubMed Central

    Lancaster, Kyle M.; DeBeer George, Serena; Yokoyama, Keiko; Richards, John H.; Gray, Harry B.

    2009-01-01

    Copper proteins play key roles in biological processes such as electron transfer and dioxygen activation; the active site of each of these proteins is classified as either type 1, 2, or 3, depending on its optical and electron paramagnetic resonance properties. We have built a new type of site that we call “type zero copper” by incorporating leucine, isoleucine, or phenylalanine in place of methionine at position 121 in C112D Pseudomonas aeruginosa azurin. X-ray crystallographic analysis shows that these sites adopt distorted tetrahedral geometries, with an unusually short Cu-O(G45 carbonyl) bond (2.35–2.55 Å). Relatively weak absorption near 800 nm and narrow parallel hyperfine splittings in EPR spectra are the spectroscopic signatures of type zero copper. Copper K-edge x-ray absorption spectra suggest elevated Cu(II) 4p character in the d-electron ground state. Cyclic voltammetric experiments demonstrate that the electron transfer reactivities of type zero azurins are enhanced relative to that of the corresponding type 2 (C112D) protein. PMID:20305734

  16. [Determination of gold in copper matte and sintered copper material].

    PubMed

    Ge, Yu-wei; Xiao, Li-mei; Suo, Jin-ling; Wang, Cheng; Hu, Xiao-min; Zhao, Shu-yun

    2011-05-01

    Ore sample, pretreated at 650 degrees C, was decomposed with aqua regia. Gold in the sample solution was then pre-concentrated by adsorbing with polyurethane foam plastic, released with thiourea solution, and determined by inductively coupled plasma-atomic emission spectrometry and flame atomic absorption spectrometry. Based on the characteristic of the copper matte and sinter containing copper, the effects of sample dissolving condition, matrix effect and interference of coexisting elements were investigated. The accuracy, precision and detection limit were discussed. The results of test show that both of the two methods were suitable for determining the contents of gold in copper matte and sintered copper material. PMID:21800614

  17. Micro-PIXE Analysis of Trace Elements in Sulfides

    SciTech Connect

    Hickmott, D.D.; Wetteland, C.; Stimac, J.; Larocque, A.C.L.; Brearley, A.

    2003-08-26

    Micro-scale Proton-induced X-ray Emission (PIXE) of trace elements (TE) in sulfides provides insights into geologic processes including magmatic system evolution, ore forming events, and fluid-flow processes. The Los Alamos nuclear microprobe was used to determine TE concentrations and ratios in sulfides from diverse geologic environments including hydrothermal ore deposits, coal seams, and metamorphic rocks. Pyrrhotite (Po) from silicic volcanics contains high Cu and Ni; Po from the Clear Lake volcanic field has higher Mo than does Po from other volcanic fields. Coal pyrites contain high Cu, As, Se, Mo and Pb, and show high As/Se and Mo/Se in marine influenced sulfides from the Lower Kittanning coal, but not in other marine-influenced coals. Sulfides are amenable to micro-PIXE studies because of the difficulties in obtaining the homogeneous standards required for many other TE microanalytical techniques.

  18. The hydrogen sulfide metabolite trimethylsulfonium is found in human urine

    NASA Astrophysics Data System (ADS)

    Lajin, Bassam; Francesconi, Kevin A.

    2016-06-01

    Hydrogen sulfide is the third and most recently discovered gaseous signaling molecule following nitric oxide and carbon monoxide, playing important roles both in normal physiological conditions and disease progression. The trimethylsulfonium ion (TMS) can result from successive methylation reactions of hydrogen sulfide. No report exists so far about the presence or quantities of TMS in human urine. We developed a method for determining TMS in urine using liquid chromatography-electrospray ionization-triple quadrupole mass spectrometry (LC-ESI-QQQ), and applied the method to establish the urinary levels of TMS in a group of human volunteers. The measured urinary levels of TMS were in the nanomolar range, which is commensurate with the steady-state tissue concentrations of hydrogen sulfide previously reported in the literature. The developed method can be used in future studies for the quantification of urinary TMS as a potential biomarker for hydrogen sulfide body pools.

  19. 21 CFR 177.2490 - Polyphenylene sulfide resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Sulfur in Organic Compounds,” “Determination of the Inherent Viscosity of Polyphenylene Sulfide,” and... viscosity: 0.13 deciliters per gram. (3) Maximum residual p-dichlorobenzene: 0.8 ppm. (b) Subject to...

  20. 21 CFR 177.2490 - Polyphenylene sulfide resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Sulfur in Organic Compounds,” “Determination of the Inherent Viscosity of Polyphenylene Sulfide,” and... viscosity: 0.13 deciliters per gram. (3) Maximum residual p-dichlorobenzene: 0.8 ppm. (b) Subject to...

  1. 21 CFR 177.2490 - Polyphenylene sulfide resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...,” “Determination of the Inherent Viscosity of Polyphenylene Sulfide,” and “Analysis for Dichlorobenzene in Ryton... percent by weight of finished resin. (2) Minimum inherent viscosity: 0.13 deciliters per gram. (3)...

  2. 21 CFR 177.2490 - Polyphenylene sulfide resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Sulfur in Organic Compounds,” “Determination of the Inherent Viscosity of Polyphenylene Sulfide,” and... viscosity: 0.13 deciliters per gram. (3) Maximum residual p-dichlorobenzene: 0.8 ppm. (b) Subject to...

  3. 21 CFR 177.2490 - Polyphenylene sulfide resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Sulfur in Organic Compounds,” “Determination of the Inherent Viscosity of Polyphenylene Sulfide,” and... viscosity: 0.13 deciliters per gram. (3) Maximum residual p-dichlorobenzene: 0.8 ppm. (b) Subject to...

  4. An Experiment in Autotrophic Fermentation: Microbial Oxidation of Hydrogen Sulfide.

    ERIC Educational Resources Information Center

    Sublette, Kerry L.

    1989-01-01

    Described is an experiment which uses an autotrophic bacterium to anaerobically oxidize hydrogen sulfide to sulfate in a batch-stirred tank reactor. Discusses background information, experimental procedure, and sample results of this activity. (CW)

  5. TREATMENT OF METAL FINISHING WASTES BY SULFIDE PRECIPITATION

    EPA Science Inventory

    This project involved precipitating heavy metals normally present in metal finishing wastewaters by a novel process which employs ferrous sulfide addition (Sulfex), as well as by conventional treatment using calcium hydroxide for comparison purposes. These studies consisted of la...

  6. Crystallinity of Fe-Ni Sulfides in Carbonaceous Chondrites

    NASA Astrophysics Data System (ADS)

    Zolensky, M. E.; Ohsumi, K.; Mikouchi, T.; Hagiya, K.; Le, L.

    2008-03-01

    We examine the crystallinity and crystal structures of Fe-Ni sulfides in five carbonaceous chondrites - Acfer 094 (CM2), Tagish Lake (C2 ungrouped), Kaidun C1, Bali (CV2/3 oxidized), and Efremovka (CV3 reduced).

  7. 40 CFR 425.03 - Sulfide analytical methods and applicability.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... sulfide in wastewaters discharged by plants operating in all subcategories except the hair save or pulp... by plants operating in the hair save or pulp, non-chrome tan, retan-wet finish subcategory (subpart...

  8. 40 CFR 425.03 - Sulfide analytical methods and applicability.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... sulfide in wastewaters discharged by plants operating in all subcategories except the hair save or pulp... by plants operating in the hair save or pulp, non-chrome tan, retan-wet finish subcategory (subpart...

  9. [Activity of hydrogen sulfide production enzymes in kidneys of rats].

    PubMed

    Mel'nyk, A V; Pentiuk, O O

    2009-01-01

    An experimental research of activity and kinetic descriptions of enzymes participating in formation of hydrogen sulfide in the kidney of rats has been carried out. It was established that cystein, homocystein and thiosulphate are the basic substrates for hydrogen sulfide synthesis. The higest activity for hydrogen sulfide production belongs to thiosulfate-dithiolsulfurtransferase and cysteine aminotransferase, less activity is characteristic of cystathionine beta-synthase and cystathio-nine gamma-lyase. The highest affinity to substrate is registered for thiosulfate-dithiolsulfurtransferase and cystathionine gamma-lyase. It is discovered that the substrate inhibition is typical of all hydrogen sulfide formation enzymes, although this characteristic is the most expressed thiosulfat-dithiolsulfurtransferase. PMID:20387629

  10. The hydrogen sulfide metabolite trimethylsulfonium is found in human urine.

    PubMed

    Lajin, Bassam; Francesconi, Kevin A

    2016-01-01

    Hydrogen sulfide is the third and most recently discovered gaseous signaling molecule following nitric oxide and carbon monoxide, playing important roles both in normal physiological conditions and disease progression. The trimethylsulfonium ion (TMS) can result from successive methylation reactions of hydrogen sulfide. No report exists so far about the presence or quantities of TMS in human urine. We developed a method for determining TMS in urine using liquid chromatography-electrospray ionization-triple quadrupole mass spectrometry (LC-ESI-QQQ), and applied the method to establish the urinary levels of TMS in a group of human volunteers. The measured urinary levels of TMS were in the nanomolar range, which is commensurate with the steady-state tissue concentrations of hydrogen sulfide previously reported in the literature. The developed method can be used in future studies for the quantification of urinary TMS as a potential biomarker for hydrogen sulfide body pools. PMID:27247020

  11. The hydrogen sulfide metabolite trimethylsulfonium is found in human urine

    PubMed Central

    Lajin, Bassam; Francesconi, Kevin A.

    2016-01-01

    Hydrogen sulfide is the third and most recently discovered gaseous signaling molecule following nitric oxide and carbon monoxide, playing important roles both in normal physiological conditions and disease progression. The trimethylsulfonium ion (TMS) can result from successive methylation reactions of hydrogen sulfide. No report exists so far about the presence or quantities of TMS in human urine. We developed a method for determining TMS in urine using liquid chromatography-electrospray ionization-triple quadrupole mass spectrometry (LC-ESI-QQQ), and applied the method to establish the urinary levels of TMS in a group of human volunteers. The measured urinary levels of TMS were in the nanomolar range, which is commensurate with the steady-state tissue concentrations of hydrogen sulfide previously reported in the literature. The developed method can be used in future studies for the quantification of urinary TMS as a potential biomarker for hydrogen sulfide body pools. PMID:27247020

  12. Origin of the Nchanga copper-cobalt deposits of the Zambian Copperbelt

    NASA Astrophysics Data System (ADS)

    McGowan, Ross R.; Roberts, Stephen; Boyce, Adrian J.

    2006-01-01

    The Zambian Copperbelt forms the southeastern part of the 900-km-long Neoproterozoic Lufilian Arc and contains one of the world’s largest accumulations of sediment-hosted stratiform copper mineralization. The Nchanga deposit is one of the most significant ore systems in the Zambian Copperbelt and contains two major economic concentrations of copper and cobalt, hosted within the Lower Roan Group of the Katangan Supergroup. A Lower Orebody (copper only) and Upper Orebody (copper and cobalt) occur towards the top of arkosic units and within the base of overlying shales. The sulfide mineralogy includes pyrite, bornite, chalcopyrite, and chalcocite, although in the Lower Orebody, sulfide phases are partially or completely replaced by malachite and copper oxides. Carrollite is the major cobalt-bearing phase and is restricted to fault-propagation fold zones within a feldspathic arenite. Hydrothermal alteration minerals include dolomite, phlogophite, sericite, rutile, quartz, tourmaline, and chlorite. Quartz veins from the mine sequence show halite-saturated fluid inclusions, ranging from ~31 to 38 wt% equivalent NaCl, with homogenisation temperatures (ThTOT) ranging between 140 and 180°C. Diagenetic pyrites in the lower orebody show distinct, relatively low δ 34S, ranging from -1 to -17‰ whereas arenite- and shale-hosted copper and cobalt sulfides reveal distinctly different δ 34S from -1 to +12‰ for the Lower Orebody and +5 to +18‰ for the Upper Orebody. There is also a clear distinction between the δ 34S mean of +12.1±3.3‰ ( n=65) for the Upper Orebody compared with +5.2±3.6‰ ( n=23) for the Lower Orebody. The δ 13C of dolomites from units above the Upper Orebody give δ 13C values of +1.4 to +2.5‰ consistent with marine carbon. However, dolomite from the shear-zones and the alteration assemblages within the Upper Orebody show more negative δ 13C values: -2.9 to -4.0‰ and -5.6 to -8.3‰, respectively. Similarly, shear zone and Upper Orebody

  13. A New Preparation Method of Ultrafine Particles of Metallic Sulfides

    NASA Astrophysics Data System (ADS)

    Kaito, Chihiro; Saito, Yoshio; Fujita, Kazuo

    1987-12-01

    Ultrafine particles of metallic sulfides have been produced by the reaction of metal and sulfur vapor. The sulfur vapor was prepared by evaporating sulfur powder from a quartz boat using the atmospheric temperature of either the heated metal or boat. Electron microscopic observation of the particles of Mo3S4 and PbS has shown them to be typical examples of the produced sulfides.

  14. Process for thin film deposition of cadmium sulfide

    DOEpatents

    Muruska, H. Paul; Sansregret, Joseph L.; Young, Archie R.

    1982-01-01

    The present invention teaches a process for depositing layers of cadmium sulfide. The process includes depositing a layer of cadmium oxide by spray pyrolysis of a cadmium salt in an aqueous or organic solvent. The oxide film is then converted into cadmium sulfide by thermal ion exchange of the O.sup.-2 for S.sup.-2 by annealing the oxide layer in gaseous sulfur at elevated temperatures.

  15. Preparation of mesoporous cadmium sulfide nanoparticles with moderate pore size

    SciTech Connect

    Han Zhaohui Zhu, Huaiyong; Shi, Jeffrey; Parkinson, Gordon; Lu, G.Q.

    2007-03-15

    The preparation of cadmium sulfide nanoparticles that have a moderate pore size is reported. This preparation method involves a hydrothermal process that produces a precursor mixture and a following acid treatment of the precursor to get the porous material. The majority of the particles have a pore size close to 20nm, which complements and fills in the gap between the existing cadmium sulfide materials, which usually have a pore size either less than 10nm or are well above 100nm.

  16. Sulfide catalysts for reducing SO2 to elemental sulfur

    DOEpatents

    Jin, Yun; Yu, Qiquan; Chang, Shih-Ger

    2001-01-01

    A highly efficient sulfide catalyst for reducing sulfur dioxide to elemental sulfur, which maximizes the selectivity of elemental sulfur over byproducts and has a high conversion efficiency. Various feed stream contaminants, such as water vapor are well tolerated. Additionally, hydrogen, carbon monoxide, or hydrogen sulfides can be employed as the reducing gases while maintaining high conversion efficiency. This allows a much wider range of uses and higher level of feed stream contaminants than prior art catalysts.

  17. Determination of Hydrogen Sulfide in Fermentation Broths Containing SO21

    PubMed Central

    Acree, T. E.; Sonoff, Elisabeth P.; Splittstoesser, D. F.

    1971-01-01

    A procedure for the determination of hydrogen sulfide in fermentation broths containing up to 100 μg of SO2 per ml is described. The method involves the sparging of H2S from the broth into a cadmium hydroxide absorption solution, the formation of methylene blue from the absorbed sulfide, and the measuring of this color spectrophotometrically. The use of cadmium hydroxide instead of zinc acetate, the common absorbent, substantially reduced the interference of SO2 with the analysis. PMID:5111300

  18. The partitioning of copper among selected phases of geologic media of two porphyry copper districts, Puerto Rico

    USGS Publications Warehouse

    Learned, R.E.; Chao, T.T.; Sanzolone, R.F.

    1981-01-01

    In experiments designed to determine the manner in which copper is partitioned among selected phases that constitute geologic media, we have applied the five-step sequential extraction procedure of Chao and Theobald to the analysis of drill core, soils, and stream sediments of the Rio Vivi and Rio Tanama porphyry copper districts of Puerto Rico. The extraction procedure affords a convenient means of determining the trace-metal content of the following fractions: (1) Mn oxides and "reactive" Fe oxides; (2) "amorphous" Fe oxides; (3) "crystalline" Fe oxides; (4) sulfides and magnetite; and (5) silicates. An additional extraction between steps (1) and (2) was performed to determine organic-related copper in stream sediments. The experimental results indicate that apportionment of copper among phases constituting geologic media is a function of geochemical environment. Distinctive partitioning patterns were derived from the analysis of drill core from each of three geochemical zones: (a) the supergene zone of oxidation; (b) the supergene zone of enrichment; and (c) the hypogene zone; and similarly, from the analysis of; (d) soils on a weakly leached capping; (e) soils on a strongly leached capping; and (f) active stream sediment. The experimental results also show that geochemical contrasts (anomaly-to-background ratios) vary widely among the five fractions of each sampling medium investigated, and that at least one fraction of each medium provides substantially stronger contrast than does the bulk medium. Fraction (1) provides optimal contrast for stream sediments of the district; fraction (2) provides optimal contrast for soils on a weakly leached capping; fraction (3) provides optimal contrast for soils on a strongly leached capping. Selective extraction procedures appear to have important applications to the orientation and interpretive stages of geochemical exploration. Further investigation and testing of a similar nature are recommended. ?? 1981.

  19. Bioavailability and stability of mercury sulfide in Armuchee (USA) soil

    SciTech Connect

    Han, Fengxiang; Shiyab, Safwan; Su, Yi; Monts, David L.; Waggoner, Charles A.; Matta, Frank B.

    2007-07-01

    Because of the adverse effects of elemental mercury and mercury compounds upon human health, the U.S. Department of Energy (DOE) is engaged in an on-going effort to monitor and remediate mercury-contaminated DOE sites. In order to more cost effectively implement those extensive remediation efforts, it is necessary to obtain an improved understanding of the role that mercury and mercury compounds play in the ecosystem. We have conducted pilot scale experiments to study the bioavailability of mercury sulfide in an Armuchee (eastern US ) soil. The effects of plants and incubation time on chemical stability and bioavailability of HgS under simulated conditions of the ecosystem have been examined, as has the dynamics of the dissolution of mercury sulfide by various extractants. The results show that mercury sulfide in contaminated Armuchee soil was still to some extent bioavailable to plants. After planting, soil mercury sulfide is more easily dissolved by both 4 M and 12 M nitric acid than pure mercury sulfide reagent. Dissolution kinetics of soil mercury sulfide and pure chemical reagent by nitric acid are different. Mercury release by EDTA from HgS-contaminated soil increased with time of reaction and soil mercury level. Chelating chemicals increase the solubility and bioavailability of mercury in HgS-contaminated soil. (authors)

  20. Sulfide as a soil phytotoxin—a review

    PubMed Central

    Lamers, Leon P. M.; Govers, Laura L.; Janssen, Inge C. J. M.; Geurts, Jeroen J. M.; Van der Welle, Marlies E. W.; Van Katwijk, Marieke M.; Van der Heide, Tjisse; Roelofs, Jan G. M.; Smolders, Alfons J. P.

    2013-01-01

    In wetland soils and underwater sediments of marine, brackish and freshwater systems, the strong phytotoxin sulfide may accumulate as a result of microbial reduction of sulfate during anaerobiosis, its level depending on prevailing edaphic conditions. In this review, we compare an extensive body of literature on phytotoxic effects of this reduced sulfur compound in different ecosystem types, and review the effects of sulfide at multiple ecosystem levels: the ecophysiological functioning of individual plants, plant-microbe associations, and community effects including competition and facilitation interactions. Recent publications on multi-species interactions in the rhizosphere show even more complex mechanisms explaining sulfide resistance. It is concluded that sulfide is a potent phytotoxin, profoundly affecting plant fitness and ecosystem functioning in the full range of wetland types including coastal systems, and at several levels. Traditional toxicity testing including hydroponic approaches generally neglect rhizospheric effects, which makes it difficult to extrapolate results to real ecosystem processes. To explain the differential effects of sulfide at the different organizational levels, profound knowledge about the biogeochemical, plant physiological and ecological rhizosphere processes is vital. This information is even more important, as anthropogenic inputs of sulfur into freshwater ecosystems and organic loads into freshwater and marine systems are still much higher than natural levels, and are steeply increasing in Asia. In addition, higher temperatures as a result of global climate change may lead to higher sulfide production rates in shallow waters. PMID:23885259