Science.gov

Sample records for sulfur compounds sulfur

  1. Sulfur compounds in coal

    NASA Technical Reports Server (NTRS)

    Attar, A.; Corcoran, W. H.

    1977-01-01

    The literature on the chemical structure of the organic sulfur compounds (or functional groups) in coal is reviewed. Four methods were applied in the literature to study the sulfur compounds in coal: direct spectrometric and chemical analysis, depolymerization in drastic conditions, depolymerization in mild conditions, and studies on simulated coal. The data suggest that most of the organic sulfur in coal is in the form of thiophenic structures and aromatic and aliphatic sulfides. The relative abundance of the sulfur groups in bituminous coal is estimated as 50:30:20%, respectively. The ratio changes during processing and during the chemical analysis. The main effects are the transformation during processing of sulfides to the more stable thiophenic compounds and the elimination of hydrogen sulfide.

  2. Thiophenic Sulfur Compounds Released During Coal Pyrolysis.

    PubMed

    Xing, Mengwen; Kong, Jiao; Dong, Jie; Jiao, Haili; Li, Fan

    2013-06-01

    Thiophenic sulfur compounds are released during coal gasification, carbonization, and combustion. Previous studies indicate that thiophenic sulfur compounds degrade very slowly in the environment, and are more carcinogenic than polycyclic aromatic hydrocarbons and nitrogenous compounds. Therefore, it is very important to study the principle of thiophenic sulfur compounds during coal conversion, in order to control their emission and promote clean coal utilization. To realize this goal and understand the formation mechanism of thiophenic sulfur compounds, this study focused on the release behavior of thiophenic sulfur compounds during coal pyrolysis, which is an important phase for all coal thermal conversion processes. The pyrolyzer (CDS-5250) and gas chromatography-mass spectrometry (Focus GC-DSQII) were used to analyze thiophenic sulfur compounds in situ. Several coals with different coal ranks and sulfur contents were chosen as experimental samples, and thiophenic sulfur compounds of the gas produced during pyrolysis under different temperatures and heating rates were investigated. Levels of benzothiophene and dibenzothiophene were obtained during pyrolysis at temperatures ranging from 200°C to 1300°C, and heating rates ranging from 6°C/ms to 14°C/ms and 6°C/s to 14°C/s. Moreover, the relationship between the total amount of benzothiophene and dibenzothiophene released during coal pyrolysis and the organic sulfur content in coal was also discussed. This study is beneficial for understanding the formation and control of thiophenic sulfur compounds, since it provides a series of significant results that show the impact that operation conditions and organic sulfur content in coal have on the amount and species of thiophenic sulfur compounds produced during coal pyrolysis. PMID:23781126

  3. Thiophenic Sulfur Compounds Released During Coal Pyrolysis

    PubMed Central

    Xing, Mengwen; Kong, Jiao; Dong, Jie; Jiao, Haili; Li, Fan

    2013-01-01

    Abstract Thiophenic sulfur compounds are released during coal gasification, carbonization, and combustion. Previous studies indicate that thiophenic sulfur compounds degrade very slowly in the environment, and are more carcinogenic than polycyclic aromatic hydrocarbons and nitrogenous compounds. Therefore, it is very important to study the principle of thiophenic sulfur compounds during coal conversion, in order to control their emission and promote clean coal utilization. To realize this goal and understand the formation mechanism of thiophenic sulfur compounds, this study focused on the release behavior of thiophenic sulfur compounds during coal pyrolysis, which is an important phase for all coal thermal conversion processes. The pyrolyzer (CDS-5250) and gas chromatography–mass spectrometry (Focus GC-DSQII) were used to analyze thiophenic sulfur compounds in situ. Several coals with different coal ranks and sulfur contents were chosen as experimental samples, and thiophenic sulfur compounds of the gas produced during pyrolysis under different temperatures and heating rates were investigated. Levels of benzothiophene and dibenzothiophene were obtained during pyrolysis at temperatures ranging from 200°C to 1300°C, and heating rates ranging from 6°C/ms to 14°C/ms and 6°C/s to 14°C/s. Moreover, the relationship between the total amount of benzothiophene and dibenzothiophene released during coal pyrolysis and the organic sulfur content in coal was also discussed. This study is beneficial for understanding the formation and control of thiophenic sulfur compounds, since it provides a series of significant results that show the impact that operation conditions and organic sulfur content in coal have on the amount and species of thiophenic sulfur compounds produced during coal pyrolysis. PMID:23781126

  4. Multiple heteroatom containing sulfur compounds in coals

    SciTech Connect

    Winans, R.E.; Neill, P.H.

    1989-01-01

    Flash vacuum pyrolysis of a high sulfur coal has been combined with high resolution mass spectrometry information on aromatic sulfur compounds containing an additional heteroatom. Sulfur emission from coal utilization is a critical problem and in order to devise efficient methods for removing organic sulfur, it is important to know what types of molecules contain sulfur. A high sulfur Illinois No. 6 bituminous coal (Argonne Premium Coal Sample No. 3) was pyrolyzed on a platinum grid using a quartz probe inserted into a modified all glass heated inlet system, and the products characterized by High Resolution Mass Spectrometry (HRMS). A significant number of products were identified which contained both sulfur and an additional heteroatom. In some cases two additional heteroatoms were observed. These results are compared to those found in coal extracted and liquefaction products. 25 refs., 5 figs., 4 tabs.

  5. Heterogeneous photocatalytic reactions of sulfur aromatic compounds.

    PubMed

    Samokhvalov, Alexander

    2011-11-18

    Sulfur aromatic compounds, such as mono-, di-, tri-, and tetraalkyl-substituted thiophene, benzothiophenes, dibenzothiophenes, are the molecular components of many fossils (petroleum, oil shale, tar sands, bitumen). Structural units of natural, cross-linked heteroaromatic polymers present in brown coals, turf, and soil are similar to those of sulfur aromatic compounds. Many sulfur aromatic compounds are found in the streams of petroleum refining and upgrading (naphthas, gas oils) and in the consumer products (gasoline, diesel, jet fuels, heating fuels). Besides fossils, the structural fragments of sulfur aromatic compounds are present in molecules of certain organic semiconductors, pesticides, small molecule drugs, and in certain biomolecules present in human body (pheomelanin pigments). Photocatalysis is the frontier area of physical chemistry that studies chemical reactions initiated by absorption of photons by photocatalysts, that is, upon electronic rather than thermal activation, under "green" ambient conditions. This review provides systematization and critical review of the fundamental chemical and physicochemical information on heterogeneous photocatalysis of sulfur aromatic compounds accumulated in the last 20-30 years. Specifically, the following topics are covered: physicochemical properties of sulfur aromatic compounds, major classes of heterogeneous photocatalysts, mechanisms and reactive intermediates of photocatalytic reactions of sulfur aromatic compounds, and the selectivity of these reactions. Quantum chemical calculations of properties and structures of sulfur aromatic compounds, their reactive intermediates, and the structure of adsorption complexes formed on the surface of the photocatalysts are also discussed. PMID:21809426

  6. Ambient Air Monitoring for Sulfur Compounds

    ERIC Educational Resources Information Center

    Forrest, Joseph; Newman, Leonard

    1973-01-01

    A literature review of analytical techniques available for the study of compounds at low concentrations points up some of the areas where further research is needed. Compounds reviewed are sulfur dioxide, sulfuric acid, ammonium sulfate and bisulfate, metal sulfates, hydrogen sulfide, and organic sulfides. (BL)

  7. Metabolic Reactions among Organic Sulfur Compounds

    NASA Technical Reports Server (NTRS)

    Schulte, M.; Rogers, K.

    2005-01-01

    Sulfur is central to the metabolisms of many organisms that inhabit extreme environments. Numerous authors have addressed the energy available from a variety of inorganic sulfur redox pairs. Less attention has been paid, however, to the energy required or gained from metabolic reactions among organic sulfur compounds. Work in this area has focused on the oxidation of alkyl sulfide or disulfide to thiol and formaldehyde, e.g. (CH3)2S + H2O yields CH3SH + HCHO + H2, eventually resulting in the formation of CO2 and SO4(-2). It is also found that reactions among thiols and disulfides may help control redox disequilibria between the cytoplasm and the periplasm. Building on our earlier efforts for thiols, we have compiled and estimated thermodynamic properties for alkyl sulfides. We are investigating metabolic reactions among various sulfur compounds in a variety of extreme environments, ranging from sea floor hydrothermal systems to organic-rich sludge. Using thermodynamic data and the revised HKF equation of state, along with constraints imposed by the geochemical environments sulfur-metabolizing organisms inhabit, we are able to calculate the amount of energy available to these organisms.

  8. Characterization of Sulfur Compounds in Coffee Beans by Sulfur K-XANES Spectroscopy

    SciTech Connect

    Lichtenberg, H.; Hormes, J.; Prange, A.; Modrow, H.

    2007-02-02

    In this 'feasibility study' the influence of roasting on the sulfur speciation in Mexican coffee beans was investigated by sulfur K-XANES Spectroscopy. Spectra of green and slightly roasted beans could be fitted to a linear combination of 'standard' reference spectra for biological samples, whereas longer roasting obviously involves formation of additional sulfur compounds in considerable amounts.

  9. Characterization of Sulfur Compounds in Coffee Beans by Sulfur K-XANES Spectroscopy

    NASA Astrophysics Data System (ADS)

    Lichtenberg, H.; Prange, A.; Modrow, H.; Hormes, J.

    2007-02-01

    In this `feasibility study' the influence of roasting on the sulfur speciation in Mexican coffee beans was investigated by sulfur K-XANES Spectroscopy. Spectra of green and slightly roasted beans could be fitted to a linear combination of `standard' reference spectra for biological samples, whereas longer roasting obviously involves formation of additional sulfur compounds in considerable amounts.

  10. Two stage sorption of sulfur compounds

    DOEpatents

    Moore, William E.

    1992-01-01

    A two stage method for reducing the sulfur content of exhaust gases is disclosed. Alkali- or alkaline-earth-based sorbent is totally or partially vaporized and introduced into a sulfur-containing gas stream. The activated sorbent can be introduced in the reaction zone or the exhaust gases of a combustor or a gasifier. High efficiencies of sulfur removal can be achieved.

  11. MANUAL METHOD FOR MEASUREMENT OF REDUCED SULFUR COMPOUNDS

    EPA Science Inventory

    A manual method for measuring reduced sulfur compounds in Kraft pulp mill and sulfur recovery plant emissions was evaluated. The method involves removing SO2 from the gas stream (if present) with a citric acid-potassium citrate buffer, that passes reduced sulfur compounds; therma...

  12. Changes in organic sulfur compounds in coal macerals during liquefaction

    SciTech Connect

    Winans, R.E.; Joseph, J.T.; Fisher, R.B.

    1994-02-01

    Several general trends were observed in reactivity patterns of sulfur compounds in macerals. Sulfur is reduced in the asphaltene fraction compared to initial maceral. Aliphatics are removed and polycyclic aromatic compounds are both stable and probably formed under these conditions. Molecules containing two sulfur atoms are formed. The preasphaltenes are now being analyzed by DEIHRMS.

  13. Sulfur compound concentrations at swine and poultry facilities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reduced sulfur compounds are emitted from waste handling at animal agriculture operations. These sulfur compounds are responsible for odor production as well as participating in atmospheric chemistry. We have adapted a chromatographic method for providing 10 minute online monitoring capability of re...

  14. Microbial desulfurization of organic sulfur compounds in petroleum.

    PubMed

    Ohshiro, T; Izumi, Y

    1999-01-01

    Sulfur removal from petroleum is important from the standpoint of the global environment because the combustion of sulfur compounds leads to the production of sulfur oxides, which are the source of acid rain. As the regulations for sulfur in fuels become more stringent, the existing chemical desulfurizations are coming inadequate for the "deeper desulfurization" to produce lower-sulfur fuels without new and innovative processes. Biodesulfurization is rising as one of the candidates. Several microorganisms were found to desulfurize dibenzothiophene (DBT), a representative of the organic sulfur compounds in petroleum, forming a sulfur-free compound, 2-hydroxybiphenyl. They are promising as biocatalysts in the microbial desulfurization of petroleum because without assimilation of the carbon content, they remove only sulfur from the heterocyclic compounds which is refractory to conventional chemical desulfurization. Both enzymological and molecular genetic studies are now in progress for the purpose of obtaining improved desulfurization activity of organisms. The genes involved in the sulfur-specific DBT desulfurization were identified and the corresponding enzymes have been investigated. From the practical point of view, it has been proved that the microbial desulfurization proceeds in the presence of high concentrations of hydrocarbons, and more complicated DBT analogs are also desulfurized by the microorganisms. This review outlines the progress in the studies of the microbial desulfurization from the basic and practical point of view. PMID:10052116

  15. Changes in organic sulfur compounds in coal macerals during liquefaction

    SciTech Connect

    Winans, R.E.; Joseph, J.T.; Fisher, R.B.

    1994-12-31

    Environmentally sound use of coal for energy production involves effective sulfur removal from the feed coal and/or coal-derived products. Physical cleaning of coal is effective in removing substantial quantities of inorganic sulfur compounds such a pyrite. However, removal of organic sulfur by physical means has not been extremely successful. It is likely that only chemical methods will be useful in substantial removal of organic sulfur. A thorough knowledge of the chemistry of organic sulfur in coal will be valuable in attempts to remove organic sulfur from coal or its liquefaction or pyrolysis products by chemical methods. Since different coal macerals have different liquefaction reactivities, the analysis of sulfur functionalities on separated macerals is deemed to be more meaningful than studying the whole coal. Liquefaction behavior and organic sulfur speciation of the macerals separated from Lewiston-Stockton coal (Argonne Premium Coal Sample bank, APCS-7) by XPS, XANES, and HRMS has been previously described. This paper describes the preliminary speciation of sulfur compounds in the asphaltene fraction of the liquefaction products from these macerals.

  16. Infrared absorption of sulfur bearing compounds

    NASA Technical Reports Server (NTRS)

    Maki, A.

    1982-01-01

    The sulfur bearing molecules of most interest in studies of planetary atmospheres are the simple, stable hydrides and oxides, H2S, H2SO4, SO2, and SO3, and the carbon containing species OCS and CO2. For interpreting spectroscopic observations, the properties that must be known are: transition frequencies, transition intensities, transition assignments in terms of quantum number assignments and lower state energy levels, and pressure broadening constants (including their temperature dependence).

  17. Method for removal of sulfur compounds from a gas

    SciTech Connect

    Frech, K.J.; Tazuma, J.J.

    1981-08-11

    This invention relates to a process for the removal of sulfur compounds from a gas stream which consists of contacting said gas stream with alkali metal salts of sulfonamides or resins containing sulfonamide functionalities.

  18. Dirchromones: Cytotoxic Organic Sulfur Compounds Isolated from Dirca palustris.

    PubMed

    St-Gelais, Alexis; Legault, Jean; Mshvildadze, Vakhtang; Pichette, André

    2015-08-28

    Eight novel organic sulfur compounds featuring an unprecedented structure among natural organosulfur molecules are reported. The identified compounds, named dirchromones (1-8), were isolated from a dichloromethane extract of the roots, bark, and wood of Dirca palustris, an endemic shrub of eastern North America. Their identification was based on thorough NMR, IR, and HRMS spectroscopic data interpretation. These compounds showed cytotoxic and mild Gram-positive antibacterial activities in vitro, while being inactive against Gram-negative Escherichia coli and the yeast Candida albicans. This is the first report of sulfur-containing compounds from a species of the Thymelaeaceae. PMID:26225905

  19. Nitrogen-sulfur compounds in stratospheric aerosols

    NASA Technical Reports Server (NTRS)

    Farlow, N. H.; Snetsinger, K. G.; Hayes, D. M.; Lem, H. Y.; Tooper, B. M.

    1978-01-01

    Two forms of nitrosyl sulfuric acid (NOHSO4 and NOHS2O7) have been tentatively identified in stratospheric aerosols. The first of these can be formed either directly from gas reactions of NO2 with SO2 or by gas-particle interactions between NO2 and H2SO4. The second product may form when SO3 is involved. Estimates based on these reactions suggest that the maximum quantity of NO that might be absorbed in stratospheric aerosols could vary from one-third to twice the amount of NO in the surrounding air. If these reactions occur in the stratosphere, then a mechanism exists for removing nitrogen oxides from that region by aerosol particle fallout. This process may typify another natural means that helps cleanse the lower stratosphere of excessive pollutants.

  20. A Systematic Presentation of Organic Phosphorus and Sulfur Compounds.

    ERIC Educational Resources Information Center

    Hendrickson, James B.

    1985-01-01

    Because the names, interrelations, and oxidation levels of the organic compounds of phosphorus and sulfur tend to confuse students, a simple way to organize these compounds has been developed. The system consists of grouping them by oxidation state and extent of carbon substitution. (JN)

  1. Sulfur compounds reduce potato toxins during extrusion cooking.

    PubMed

    Surjawan, I; Dougherty, M P; Bushway, R J; Bushway, A A; Briggs, J L; Camire, M E

    2001-06-01

    Free sulfhydryl groups in sulfur compounds have been reported to act directly on natural toxins to reduce toxicity. The objective of this study was to reduce protease inhibitors and glycoalkaloids in simulated snack foods by the addition of sulfur-containing compounds prior to extrusion. Thiamine, methionine, and benzyl disulfide were added to potato flakes at levels of 0.5% or 1.0% prior to twin-screw extrusion. Total and free thiols and protease inhibitors were monitored before and after extrusion by colorimetric assays. Potato glycoalkaloids were analyzed by HPLC and by immunoassay. Extrusion reduced potato flake disulfide bonds; disulfide bonds were higher in samples containing added sulfur compounds. Trypsin inhibitor activity was reduced by as much as 79% by extrusion plus methionine. Extrusion significantly reduced carboxypeptidase inhibitor, but only when benzyl disulfide and 0.5% methionine were not added. One percent methionine and thiamine resulted in 60% reductions in glycoalkaloids. PMID:11409974

  2. Transition metal-mediated desulfurization of aromatic sulfur compounds

    SciTech Connect

    Eisch, J.J.; Im, K.R.; Hallenbeck, L.E.

    1980-03-01

    The presence of organic sulfur in various coals and crude petroleum stocks constitutes a serious problem in producing environmentally acceptable fuels. Accordingly, a worthy objective of fuel research would be to discover energy-efficient ways of cleaving organic sulfur bonds in coal, petroleum or ther derived liquids, so as to minimize atmospheric pollution caused by organic sulfide or mercaptan contaminants in fuels. Since existing desulfurization procedures generally require elevated temperatures, high pressures of hydrogen and the use of heterogeneous catalysts, a search has been launched for desulfurization processes effective under milder conditions, namely those involving homogeneous transition-metal agents. In order to learn more about the fundamental chemistry of carbon-sulfur bond cleavages by transition metals, we have chosen as substrates those aromatic sulfur compounds that are typical of the stable organic sulfur constituents found in coal tar or petroleum stocks, namely dibenzothiophene (Ia), phenoxathiin (Ib), phenothiazine (Ic) and thianthrene (Id), as well as various open-chain sulfides (Ar-S-Ar) and mercaptans (ArSH). Although some soluble nickel (O) complexes, such as bis (1,5-cyclooctadiene) nickel (O), are unreactive in desulfurization, a change of the ligands about nickel causes a striking rise in reactivity. With the aromatic sulfur heterocycles (Ib-Id), either desulfurization with ring contraction or hydrodesulfurization could be achieved, depending on the reaction conditions (1,2). Recent findings on the mechanisms of these unusual desulfurizations are reported.

  3. Process for removal of sulfur compounds from fuel gases

    DOEpatents

    Moore, Raymond H.; Stegen, Gary E.

    1978-01-01

    Fuel gases such as those produced in the gasification of coal are stripped of sulfur compounds and particulate matter by contact with molten metal salt. The fuel gas and salt are intimately mixed by passage through a venturi or other constriction in which the fuel gas entrains the molten salt as dispersed droplets to a gas-liquid separator. The separated molten salt is divided into a major and a minor flow portion with the minor flow portion passing on to a regenerator in which it is contacted with steam and carbon dioxide as strip gas to remove sulfur compounds. The strip gas is further processed to recover sulfur. The depleted, minor flow portion of salt is passed again into contact with the fuel gas for further sulfur removal from the gas. The sulfur depleted, fuel gas then flows through a solid absorbent for removal of salt droplets. The minor flow portion of the molten salt is then recombined with the major flow portion for feed to the venturi.

  4. Uses of lunar sulfur

    SciTech Connect

    Vaniman, D.T.; Pettit, D.R.; Heiken, G.

    1988-01-01

    Sulfur and sulfur compounds have a wide range of applications for their fluid, electrical, chemical and biochemical properties. Although low in abundance on the Moon (/approximately/0.1% in mare soils), sulfur is surface-correlated and relatively extractable. Co-production of sulfur during oxygen extraction from ilmenite-rich soils could yield sulfur in masses up to 10% of the mass of oxygen produced. Sulfur deserves serious consideration as a lunar resource. 29 refs., 3 figs.

  5. Uses of lunar sulfur

    NASA Technical Reports Server (NTRS)

    Vaniman, D.; Pettit, D.; Heiken, G.

    1992-01-01

    Sulfur and sulfur compounds have a wide range of applications for their fluid, electrical, chemical, and biochemical properties. Although known abundances on the Moon are limited (approximately 0.1 percent in mare soils), sulfur is relatively extractable by heating. Coproduction of sulfur during oxygen extraction from ilmenite-rich mare soils could yield sulfur in masses up to 10 percent of the mass of oxygen produced. Sulfur deserves serious consideration as a lunar resource.

  6. Influence of sulfur compounds on the terrestrial carbon cycle

    NASA Astrophysics Data System (ADS)

    Eliseev, A. V.

    2015-11-01

    Using the climate model developed at the A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS CM), numerical experiments have been conducted in line with the Coupled Model Intercomparison Project Phase 5 (CMIP5), but scaling the anthropogenic emissions of sulfur compounds into the troposphere by ±25%. Two types of impacts of sulfur compounds on climate and the global carbon cycle are considered: climate impact (CI, associated with the influence of tropospheric sulfates on climate and, as a consequence, on the carbon cycle characteristics) and ecological impact (EI, associated with the influence of SO2 on the rate of photosynthesis of terrestrial plants). The climate impact was found to be generally more important than the ecological one. However, in a number of regions, the EI is comparable to CI, including in the southeast parts of North America and, especially, of Asia. The contribution of EI to the change in global characteristics of terrestrial ecosystems in the 20th century is likewise considerable. The CI is generally more sensitive to the uncertainty in anthropogenic emissions of sulfur compounds into the troposphere than the EI.

  7. Hydrodesulfurization reactivities of various sulfur compounds in vacuum gas oil

    SciTech Connect

    Ma, X.; Sakanishi, K.; Mochida, I.

    1996-08-01

    The hydrodesulfurization (HDS) of a vacuum gas oil (VGO) was performed at 360 C (6.9 MPa) over a commercial NiMo catalyst to examine the HDS reactivities of various sulfur compounds which exist in the VGO by means of quantitative pseudo-first-order kinetic analysis. Four representative types of aromatic-skeleton sulfur compounds were observed in the VGO: alkylbenzothiophenes (BTs), alkyldibenzothiophenes (DBTs), alkylphenanthro[4,5-b,c,d]thiophenes (PTs), and alkylbenzonaphthothiophenes (BNTs). Among these, alkyl-BTs exhibited the highest HDS reactivity, whereas alkyl-DBTs with alkyl substituents at the 4 and/or 6 positions appeared to have the least reactivity even though their aromatic-skeleton is smaller than those of both alkyl-PTs and -BNTs. Steric hindrance of alkyl groups at specific positions appears to be a major reason for the low reactivity. Quantum chemical calculations on representative sulfur compounds were carried out to compare molecular parameters with their different HDS reactivities.

  8. Emission of volatile sulfur compounds from spruce trees

    SciTech Connect

    Rennenberg, H.; Huber, B.; Schroeder, P.; Stahl, K.; Haunold, W.; Georgil, H.W.; Slovik, S.; Pfanz, H. )

    1990-03-01

    Spruce (Picea abies L.) trees from the same clone were supplied with different, but low, amounts of plant available sulfate in the soil (9.7-18.1 milligrams per 100 grams of soil). Branches attached to the trees were enclosed in a dynamic gas exchange cuvette and analyzed for the emission of volatile sulfur compounds. Independent of the sulfate supply in the soil, H{sub 2}S was the predominant reduced sulfur compound continuously emitted from the branches with high rates during the day and low rates in the night. In the light, as well as in the dark, the rates of H{sub 2}S emission increased exponentially with increasing water vapor flux from the needles. Approximately 1 nanomole of H{sub 2}S was found to be emitted per mole of water. When stomata were closed completely, only minute emission of H{sub 2}S was observed. Apparently, H{sub 2}S emission from the needles is highly dependent on stromatal aperture, and permeation through the cuticle is negligible. In several experiments, small amounts of dimethylsulfide and carbonylsulfide were also detected in a portion of the samples. However, SO{sub 2} was the only sulfur compound consistently emitted from branches of spruce trees in addition to H{sub 2}S. Emission of SO{sub 2} mainly proceeded via an outburst starting before the beginning of the light period. The total amount of SO{sub 2} emitted from the needles during this outburst was correlated with the plant available sulfate in the soil. The diurnal changes in sulfur metabolism that may result in an outburst of SO{sub 2} are discussed.

  9. Quadruple sulfur isotope constraints on the origin and cycling of volatile organic sulfur compounds in a stratified sulfidic lake

    NASA Astrophysics Data System (ADS)

    Oduro, Harry; Kamyshny, Alexey; Zerkle, Aubrey L.; Li, Yue; Farquhar, James

    2013-11-01

    We have quantified the major forms of volatile organic sulfur compounds (VOSCs) distributed in the water column of stratified freshwater Fayetteville Green Lake (FGL), to evaluate the biogeochemical pathways involved in their production. The lake's anoxic deep waters contain high concentrations of sulfate (12-16 mmol L-1) and sulfide (0.12 μmol L-1 to 1.5 mmol L-1) with relatively low VOSC concentrations, ranging from 0.1 nmol L-1 to 2.8 μmol L-1. Sulfur isotope measurements of combined volatile organic sulfur compounds demonstrate that VOSC species are formed primarily from reduced sulfur (H2S/HS-) and zero-valent sulfur (ZVS), with little input from sulfate. Thedata support a role of a combination of biological and abiotic processes in formation of carbon-sulfur bonds between reactive sulfur species and methyl groups of lignin components. These processes are responsible for very fast turnover of VOSC species, maintaining their low levels in FGL. No dimethylsulfoniopropionate (DMSP) was detected by Electrospray Ionization Mass Spectrometry (ESI-MS) in the lake water column or in planktonic extracts. These observations indicate a pathway distinct from oceanic and coastal marine environments, where dimethylsulfide (DMS) and other VOSC species are principally produced via the breakdown of DMSP by plankton species.

  10. The role of labile sulfur compounds in thermochemical sulfate reduction

    USGS Publications Warehouse

    Amrani, A.; Zhang, T.; Ma, Q.; Ellis, G.S.; Tang, Y.

    2008-01-01

    The reduction of sulfate to sulfide coupled with the oxidation of hydrocarbons to carbon dioxide, commonly referred to as thermochemical sulfate reduction (TSR), is an important abiotic alteration process that most commonly occurs in hot carbonate petroleum reservoirs. In the present study we focus on the role that organic labile sulfur compounds play in increasing the rate of TSR. A series of gold-tube hydrous pyrolysis experiments were conducted with n-octane and CaSO4 in the presence of reduced sulfur (e.g. H2S, S??, organic S) at temperatures of 330 and 356 ??C under a constant confining pressure. The in-situ pH was buffered to 3.5 (???6.3 at room temperature) with talc and silica. For comparison, three types of oil with different total S and labile S contents were reacted under similar conditions. The results show that the initial presence of organic or inorganic sulfur compounds increases the rate of TSR. However, organic sulfur compounds, such as 1-pentanethiol or diethyldisulfide, were significantly more effective in increasing the rate of TSR than H2S or elemental sulfur (on a mole S basis). The increase in rate is achieved at relatively low concentrations of 1-pentanethiol, less than 1 wt% of the total n-octane, which is comparable to the concentration of organic S that is common in many oils (???0.3 wt%). We examined several potential reaction mechanisms to explain the observed reactivity of organic LSC. First, the release of H2S from the thermal degradation of thiols was discounted as an important mechanism due to the significantly greater reactivity of thiol compared to an equivalent amount of H2S. Second, we considered the generation of olefines in association with the elimination of H2S during thermal degradation of thiols because olefines are much more reactive than n-alkanes during TSR. In our experiments, olefines increased the rate of TSR, but were less effective than 1-pentanethiol and other organic LSC. Third, the thermal decomposition of organic LSC creates free-radicals that in turn might initiate a radical chain-reaction that creates more reactive species. Experiments involving radical initiators, such as diethyldisulfide and benzyldisulfide, did not show an increase in reactivity compared to 1-pentanethiol. Therefore, we conclude that none of these can sufficiently explain our observations of the initial stages of TSR; they may, however, be important in the later stages. In order to gain greater insight into the potential mechanism for the observed reactivity of these organic sulfur compounds during TSR, we applied density functional theory-based molecular modeling techniques to our system. The results of these calculations indicate that 1-pentanethiol or its thermal degradation products may directly react with sulfate and reduce the activation energy required to rupture the first S-O bond through the formation of a sulfate ester. This study demonstrates the importance of labile sulfur compounds in reducing the onset timing and temperature of TSR. It is therefore essential that labile sulfur concentrations are taken into consideration when trying to make accurate predictions of TSR kinetics and the potential for H2S accumulation in petroleum reservoirs. ?? 2008.

  11. The role of labile sulfur compounds in thermochemical sulfate reduction

    NASA Astrophysics Data System (ADS)

    Amrani, Alon; Zhang, Tongwei; Ma, Qisheng; Ellis, Geoffrey S.; Tang, Yongchun

    2008-06-01

    The reduction of sulfate to sulfide coupled with the oxidation of hydrocarbons to carbon dioxide, commonly referred to as thermochemical sulfate reduction (TSR), is an important abiotic alteration process that most commonly occurs in hot carbonate petroleum reservoirs. In the present study we focus on the role that organic labile sulfur compounds play in increasing the rate of TSR. A series of gold-tube hydrous pyrolysis experiments were conducted with n-octane and CaSO4 in the presence of reduced sulfur (e.g. H2S, S°, organic S) at temperatures of 330 and 356 °C under a constant confining pressure. The in-situ pH was buffered to 3.5 (∼6.3 at room temperature) with talc and silica. For comparison, three types of oil with different total S and labile S contents were reacted under similar conditions. The results show that the initial presence of organic or inorganic sulfur compounds increases the rate of TSR. However, organic sulfur compounds, such as 1-pentanethiol or diethyldisulfide, were significantly more effective in increasing the rate of TSR than H2S or elemental sulfur (on a mole S basis). The increase in rate is achieved at relatively low concentrations of 1-pentanethiol, less than 1 wt% of the total n-octane, which is comparable to the concentration of organic S that is common in many oils (∼0.3 wt%). We examined several potential reaction mechanisms to explain the observed reactivity of organic LSC. First, the release of H2S from the thermal degradation of thiols was discounted as an important mechanism due to the significantly greater reactivity of thiol compared to an equivalent amount of H2S. Second, we considered the generation of olefines in association with the elimination of H2S during thermal degradation of thiols because olefines are much more reactive than n-alkanes during TSR. In our experiments, olefines increased the rate of TSR, but were less effective than 1-pentanethiol and other organic LSC. Third, the thermal decomposition of organic LSC creates free-radicals that in turn might initiate a radical chain-reaction that creates more reactive species. Experiments involving radical initiators, such as diethyldisulfide and benzyldisulfide, did not show an increase in reactivity compared to 1-pentanethiol. Therefore, we conclude that none of these can sufficiently explain our observations of the initial stages of TSR; they may, however, be important in the later stages. In order to gain greater insight into the potential mechanism for the observed reactivity of these organic sulfur compounds during TSR, we applied density functional theory-based molecular modeling techniques to our system. The results of these calculations indicate that 1-pentanethiol or its thermal degradation products may directly react with sulfate and reduce the activation energy required to rupture the first S-O bond through the formation of a sulfate ester. This study demonstrates the importance of labile sulfur compounds in reducing the onset timing and temperature of TSR. It is therefore essential that labile sulfur concentrations are taken into consideration when trying to make accurate predictions of TSR kinetics and the potential for H2S accumulation in petroleum reservoirs.

  12. Tandem sulfur chemiluminescence and flame ionization detection with planar microfluidic devices for the characterization of sulfur compounds in hydrocarbon matrices.

    PubMed

    Luong, J; Gras, R; Shellie, R A; Cortes, H J

    2013-07-01

    The detection of sulfur compounds in different hydrocarbon matrices, from light hydrocarbon feedstocks to medium synthetic crude oil feeds provides meaningful information for optimization of refining processes as well as demonstration of compliance with petroleum product specifications. With the incorporation of planar microfluidic devices in a novel chromatographic configuration, sulfur compounds from hydrogen sulfide to alkyl dibenzothiophenes and heavier distributions of sulfur compounds over a wide range of matrices spanning across a boiling point range of more than 650°C can be characterized, using one single analytical configuration in less than 25min. In tandem with a sulfur chemiluminescence detector for sulfur analysis is a flame ionization detector. The flame ionization detector can be used to establish the boiling point range of the sulfur compounds in various hydrocarbon fractions for elemental specific simulated distillation analysis as well as profiling the hydrocarbon matrices for process optimization. Repeatability of less than 3% RSD (n=20) over a range of 0.5-1000 parts per million (v/v) was obtained with a limit of detection of 50 parts per billion and a linear range of 0.5-1000 parts per million with a correlation co-efficient of 0.998. PMID:23726084

  13. Removal of Sulfur Compounds from Coal by the Thermophilic Organism Sulfolobus acidocaldarius

    PubMed Central

    Kargi, Fikret; Robinson, James M.

    1982-01-01

    The thermophilic, reduced-sulfur, iron-oxidizing bacterium Sulfolobus acidocaldarius was used for the removal of sulfur compounds from coal. The inclusion of complex nutrients such as yeast extract and peptone, and chemical oxidizing agents, 0.01 M FeCl3 into leaching medium, reduced the rate and the extent of sulfur removal from coal. The rate of sulfur removal by S. acidocaldarius was strongly dependent on the sulfur content of the coal and on the total external surface area of coal particles. Approximately 96% of inorganic sulfur was removed from a 5% slurry of coal which had an initial total sulfur content of 4% and an inorganic (pyritic S and sulfate) sulfur content of 2.1%. This resulted in removal of 50% of initial total sulfur present in coal. PMID:16346112

  14. The Sulfur Cycle

    ERIC Educational Resources Information Center

    Kellogg, W. W.; And Others

    1972-01-01

    A model estimating the contributions of sulfur compounds by natural and human activities, and the rate of removal of sulfur from the atmosphere, is based on a review of the existing literature. Areas requiring additional research are identified. (AL)

  15. Removal of sulfur compounds from combustion product exhaust

    DOEpatents

    Cheng, Dah Y.

    1982-01-01

    A method and device are disclosed for removing sulfur containing contaminents from a combustion product exhaust. The removal process is carried out in two stages wherein the combustion product exhaust is dissolved in water, the water being then heated to drive off the sulfur containing contaminents. The sulfur containing gases are then resolublized in a cold water trap to form a concentrated solution which can then be used as a commercial product.

  16. Occurrence and abatement of volatile sulfur compounds during biogas production.

    PubMed

    Andersson, Fräs Annika T; Karlsson, Anna; Svensson, Bo H; Ejlertsson, Jörgen

    2004-07-01

    Volatile sulfur compounds (VSCs) in biogas originating from a biogas production plant and from a municipal sewage water treatment plant were identified. Samples were taken at various stages of the biogas-producing process, including upgrading the gas to vehicle-fuel quality. Solid-phase microextraction was used for preconcentration of the VSCs, which were subsequently analyzed using gas chromatography in combination with mass spectrometry. Other volatile organic compounds present also were identified. The most commonly occurring VSCs in the biogas were hydrogen sulfide, carbonyl sulfide, methanethiol, dimethyl sulfide, and dimethyl disulfide, and hydrogen sulfide was not always the most abundant sulfur (S) compound. Besides VSCs, oxygenated organic compounds were commonly present (e.g., ketones, alcohols, and esters). The effect of adding iron chloride to the biogas reactor on the occurrence of VSCs also was investigated. It was found that additions of 500-g/m3 substrate gave an optimal removal of VSCs. Also, the use of a prefermentation step could reduce the amount of VSCs formed in the biogas process. Moreover, in the carbon dioxide scrubber used for upgrading the gas, VSCs were removed efficiently, leaving traces (ppbv levels). The scrubber also removed other organic compounds. PMID:15303298

  17. Effects of inorganic sulfur addition on fluxes of volatile sulfur compounds in Sphagnum peatlands

    NASA Technical Reports Server (NTRS)

    Demello, William Zamboni; Hines, Mark E.; Bayley, Suzanne E.

    1992-01-01

    Short and long-term impacts of increased S deposition on fluxes of volatile S compounds (VSC's) from Sphagnum peatlands were investigated in an artificially acidified (sulfuric and nitric acids) poor fen (Mire 239) at the Experimental Lakes Area (ELA), Ontario, Canada. Additional experiments were conducted in a poor fen (Sallie's Fen) in Barrington, NH, USA. At Mire 239, emissions of VSC's were monitored, before and after acidification, at control (unacidified) and experimental sections within two major physiographic zones of the mire (oligotrophic and minerotrophic). The experimental segments of the mire received S amendments since 1983, in amounts equivalent to the annual S deposition in the highest polluted areas of Canada and U.S. Dimethyl sulfide (DMS) was the predominant VSC released from the mire and varied largely with time and space (i.e., from 2.5 to 127 nmol/m(sup -2)h(sup -1)). Sulfur addition did not affect DMS emissions in a period of hours to a few days, although it stimulated production of DMS and MSH in the anoxic surficial regions of the peat. DMS emissions in the experimental oligotrophic segment of the mire was approximately 3-fold greater than in the control oligotrophic segment, and approximately 10-fold greater than in the minerotrophic zones. These differences could be due to a combination of differences in types of vegetation, nutritional status, and S input. At Sallie's Fen, DMS fluxes were approximately 8 times higher from a Sphagnum site than from a bare peat site. Fluxes of VSC's were not significantly affected by sulfate amendments at both sites, while DMS and MSH concentrations increases greatly with time in the top 10 cm of the peat column. Our data indicated that although Sphagnum is not the direct source of DMS released from Sphagnum peatlands, it might play a role in regulating DMS emissions to the atmosphere.

  18. Microbial cycling of volatile organic sulfur compounds in anoxic environments.

    PubMed

    Lomans, B P; Pol, A; Op den Camp, H J M

    2002-01-01

    Microbial cycling of volatile organic sulfur compounds (VOSC) is investigated due to the impact these compounds are thought to have on environmental processes like global temperature control, acid precipitation and the global sulfur cycle. Moreover, in several kinds of industries like composting plants and the paper industry VOSC are released causing odor problems. Waste streams containing these compounds must be treated in order to avoid the release of these compounds to the atmosphere. This paper describes the general mechanisms for the production and degradation of methanethiol (MT) and dimethyl sulfide (DMS), two ubiquitous VOSC in anaerobic environments. Slurry incubations indicated that methylation of sulfide and MT resulting in MT and DMS, respectively, is one of the major mechanisms for VOSC in sulfide-rich anaerobic environments. An anaerobic bacterium that is responsible for the formation of MT and DMS through the anaerobic methylation of H2S and MT was isolated from a freshwater pond after enrichment with syringate as a methyl group donating compound and sole carbon source. In spite of the continuous formation of MT and DMS, steady state concentrations are generally very low. This is due to the microbial degradation of these compounds. Experiments with sulfate-rich and sulfate-amended sediment slurries demonstrated that besides methanogens, sulfate-reducing bacteria can also degrade MT and DMS, provided that sulfate is available. A methanogen was isolated that is able to grow on DMS as the sole carbon source. A large survey of sediments slurries of various origin demonstrated that both isolates are commonly occurring inhabitants of anaerobic environments. PMID:12188577

  19. Portable instrument and method for detecting reduced sulfur compounds in a gas

    DOEpatents

    Gaffney, J.S.; Kelly, T.J.; Tanner, R.L.

    1983-06-01

    A portable real time instrument for detecting concentrations in the part per billion range of reduced sulfur compounds in a sample gas. Ozonized air or oxygen and reduced sulfur compounds in a sample gas stream react to produce chemiluminescence in a reaction chamber and the emitted light is filtered and observed by a photomultiplier to detect reduced sulfur compounds. Selective response to individual sulfur compounds is achieved by varying reaction chamber temperature and ozone and sample gas flows, and by the use of either air or oxygen as the ozone source gas.

  20. Scalping of light volatile sulfur compounds by wine closures.

    PubMed

    Silva, Maria A; Jourdes, Michaël; Darriet, Philippe; Teissedre, Pierre-Louis

    2012-11-01

    Closures have an important influence on wine quality during aging in a bottle. Closures have a direct impact on oxygen exposure and on volatiles scavenging in wine. Model wine solution soaking assays of several types of closures (i.e., natural and technical cork stoppers, synthetic closures, screw caps) with two important wine volatile sulfur compounds led to a considerable reduction in their levels. After 25 days, cork closures and synthetic closures, to a lesser extent, have significantly scavenged hydrogen sulfide and dimethyl sulfide. These compounds have a determinant impact on wine aging bouquet, being largely responsible for "reduced off-flavors". Hydrogen sulfide levels are often not well correlated with the exposure of wine to oxygen or with the permeability of the closure. Its preferential sorption by some types of closures may explain that behavior. Scalping phenomenon should be taken into account when studying wine post-bottling development. PMID:23072649

  1. Sulfur recovery process

    SciTech Connect

    Hise, R.E.; Cook, W.J.

    1991-06-04

    This paper describes a method for recovering sulfur from a process feed stream mixture of gases comprising sulfur-containing compounds including hydrogen sulfide using the Claus reaction to convert sulfur-containing compounds to elemental sulfur and crystallization to separate sulfur-containing compounds from a tail gas of the Claus reaction for further processing as a recycle stream. It comprises: providing a Claus feed stream containing a stoichiometric excess of hydrogen sulfide, the Claus feed stream including the process feed stream and the recycles stream; introducing the Claus feed stream and an oxidizing agent into a sulfur recovery unit for converting sulfur-containing compounds in the Claus feed stream to elemental sulfur; withdrawing the tail gas from the sulfur recovery unit; separating water from the tail gas to producing a dehydrated tail gas; separating sulfur-containing compounds including carbonyl sulfide from the dehydrated tail gas as an excluded material by crystallization and withdrawing an excluded material-enriched output from the crystallization to produce the recycle stream; and combining the recycle stream with the process feed stream to produce the Claus feed stream.

  2. Lunar sulfur

    NASA Technical Reports Server (NTRS)

    Kuck, David L.

    1991-01-01

    Ideas introduced by Vaniman, Pettit and Heiken in their 1988 Uses of Lunar Sulfur are expanded. Particular attention is given to uses of SO2 as a mineral-dressing fluid. Also introduced is the concept of using sulfide-based concrete as an alternative to the sulfur-based concretes proposed by Leonard and Johnson. Sulfur is abundant in high-Ti mare basalts, which range from 0.16 to 0.27 pct. by weight. Terrestrial basalts with 0.15 pct. S are rare. For oxygen recovery, sulfur must be driven off with other volatiles from ilmenite concentrates, before reduction. Troilite (FeS) may be oxidized to magnetite (Fe3O4) and SO2 gas, by burning concentrates in oxygen within a magnetic field, to further oxidize ilmenite before regrinding the magnetic reconcentration. SO2 is liquid at -20 C, the mean temperature underground on the Moon, at a minimum of 0.6 atm pressure. By using liquid SO2 as a mineral dressing fluid, all the techniques of terrestrial mineral separation become available for lunar ores and concentrates. Combination of sulfur and iron in an exothermic reaction, to form iron sulfides, may be used to cement grains of other minerals into an anhydrous iron-sulfide concrete. A sulfur-iron-aggregate mixture may be heated to the ignition temperature of iron with sulfur to make a concrete shape. The best iron, sulfur, and aggregate ratios need to be experimentally established. The iron and sulfur will be by-products of oxygen production from lunar minerals.

  3. Sulfuric odorous compounds emitted from pig-feeding operations

    NASA Astrophysics Data System (ADS)

    Kim, Ki Youn; Ko, Han Jong; Kim, Hyeon Tae; Kim, Yoon Shin; Roh, Young Man; Lee, Cheol Min; Kim, Hyun Soo; Kim, Chi Nyon

    The objective of the study was to quantify the concentration and emission levels of sulfuric odorous compounds emitted from pig-feeding operations. Five types of pig-housing rooms were studied: gestation, farrowing, nursery, growing and fattening rooms. The concentration range of sulfuric odorous compounds in these pig-housing rooms were 30-200 ppb for hydrogen sulfide (H 2S), 2.5-20 ppb for methyl mercaptan (CH 3SH), 1.5-12 ppb for dimethyl sulfide (DMS; CH 3SCH 3) and 0.5-7 ppb for dimethyl disulfide (DMDS; CH 3S 2CH 3), respectively. The emission rates of H 2S, CH 3SH, DMS and DMDS were estimated by multiplying the average concentration (mg m -3) measured near the air outlet by the mean ventilation rate (m 3 h -1) and expressed either per area (mg m -2 h -1) or animal unit (AU; liveweight of the pig, 500 kg) (mg pig -1 h -1). As a result, the emission rates of H 2S, CH 3SH, DMS and DMDS in the pig-housing rooms were 14-64, 0.8-7.3, 0.4-3.4 and 0.2-1.9 mg m -2 h -1, respectively, based on pig's activity space and 310-723, 18-80, 9-39 and 5-22 mg AU -1 h -1, respectively, based on pig's liveweight, which indicates that their emission rates were similar, whether based upon the pig's activity space or liveweight. In conclusion, the concentrations and emission rates of H 2S were highest in the fattening room followed by the growing, nursery, farrowing and gestation rooms whereas those of CH 3SH, DMS and DMDS concentrations were largest in the growing room followed by the nursery, gestation and farrowing rooms.

  4. ATP-sulfurylase, sulfur-compounds, and plant stress tolerance

    PubMed Central

    Anjum, Naser A.; Gill, Ritu; Kaushik, Manjeri; Hasanuzzaman, Mirza; Pereira, Eduarda; Ahmad, Iqbal; Tuteja, Narendra; Gill, Sarvajeet S.

    2015-01-01

    Sulfur (S) stands fourth in the list of major plant nutrients after N, P, and K. Sulfate (SO42-), a form of soil-S taken up by plant roots is metabolically inert. As the first committed step of S-assimilation, ATP-sulfurylase (ATP-S) catalyzes SO42--activation and yields activated high-energy compound adenosine-5′-phosphosulfate that is reduced to sulfide (S2-) and incorporated into cysteine (Cys). In turn, Cys acts as a precursor or donor of reduced S for a range of S-compounds such as methionine (Met), glutathione (GSH), homo-GSH (h-GSH), and phytochelatins (PCs). Among S-compounds, GSH, h-GSH, and PCs are known for their involvement in plant tolerance to varied abiotic stresses, Cys is a major component of GSH, h-GSH, and PCs; whereas, several key stress-metabolites such as ethylene, are controlled by Met through its first metabolite S-adenosylmethionine. With the major aim of briefly highlighting S-compound-mediated role of ATP-S in plant stress tolerance, this paper: (a) overviews ATP-S structure/chemistry and occurrence, (b) appraises recent literature available on ATP-S roles and regulations, and underlying mechanisms in plant abiotic and biotic stress tolerance, (c) summarizes ATP-S-intrinsic regulation by major S-compounds, and (d) highlights major open-questions in the present context. Future research in the current direction can be devised based on the discussion outcomes. PMID:25904923

  5. ATP-sulfurylase, sulfur-compounds, and plant stress tolerance.

    PubMed

    Anjum, Naser A; Gill, Ritu; Kaushik, Manjeri; Hasanuzzaman, Mirza; Pereira, Eduarda; Ahmad, Iqbal; Tuteja, Narendra; Gill, Sarvajeet S

    2015-01-01

    Sulfur (S) stands fourth in the list of major plant nutrients after N, P, and K. Sulfate (SO4 (2-)), a form of soil-S taken up by plant roots is metabolically inert. As the first committed step of S-assimilation, ATP-sulfurylase (ATP-S) catalyzes SO4 (2-)-activation and yields activated high-energy compound adenosine-5(')-phosphosulfate that is reduced to sulfide (S(2-)) and incorporated into cysteine (Cys). In turn, Cys acts as a precursor or donor of reduced S for a range of S-compounds such as methionine (Met), glutathione (GSH), homo-GSH (h-GSH), and phytochelatins (PCs). Among S-compounds, GSH, h-GSH, and PCs are known for their involvement in plant tolerance to varied abiotic stresses, Cys is a major component of GSH, h-GSH, and PCs; whereas, several key stress-metabolites such as ethylene, are controlled by Met through its first metabolite S-adenosylmethionine. With the major aim of briefly highlighting S-compound-mediated role of ATP-S in plant stress tolerance, this paper: (a) overviews ATP-S structure/chemistry and occurrence, (b) appraises recent literature available on ATP-S roles and regulations, and underlying mechanisms in plant abiotic and biotic stress tolerance, (c) summarizes ATP-S-intrinsic regulation by major S-compounds, and (d) highlights major open-questions in the present context. Future research in the current direction can be devised based on the discussion outcomes. PMID:25904923

  6. Measurements of sulfur compounds in CO 2 by diode laser atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Franzke, J.; Stancu, D. G.; Niemax, K.

    2003-07-01

    Two simple methods for the analysis of the total concentration of sulfur in CO 2 by diode laser atomic absorption spectrometry of excited, metastable sulfur atoms in a direct current discharge are presented. In the first method, the CO 2 sample gas is mixed with the plasma gas (Ar or He) while the second is based on reproducible measurements of the sulfur released from the walls in a helium discharge after being deposited as a result of operating the discharge in pure CO 2 sample gas. The detection limits obtained satisfy the requirements for the control of sulfur compounds in CO 2 used in the food and beverage industry.

  7. Microwave spectra of some sulfur and nitrogen compounds. [for chemical analysis

    NASA Technical Reports Server (NTRS)

    White, W. F.

    1974-01-01

    A computer-controlled microwave spectrometer was used to catalog reference spectra for chemical analysis. The apparatus, software, and experimental procedures are described. Tables of absorption frequencies, peak absorption coefficients, and integrated intensities are included for 13 sulfur compounds, 14 nitrogen compounds, and 1 compound containing both sulfur and nitrogen. The frequency range covered was 26,500 to 40,000 MHz for most compounds and 18,000 to 40,000 MHz for some.

  8. Effect of sulfur and its compounds on the performance of graphite electrooxidation in molten carbonate

    NASA Astrophysics Data System (ADS)

    Liu, Jia; Ye, Ke; Du, Mengmeng; Yin, Jinling; Cao, Dianxue; Wang, Guiling

    2015-01-01

    Direct carbon fuel cells are promising power sources with their performance significantly depending on the electrooxidation activity of carbon fuel. The impurities in the carbon fuel may affect the anode reactions. Sulfur and some of its inorganic compounds (CaSO4, K2SO3, K2S, FeS2) were added in molten carbonate and their effect on graphite electrooxidation was investigated. Cyclic voltammograms of gold electrode with addition of these sulfur compounds showed CaSO4 was stable and other compounds were electrochemically oxidized to high valence state sulfur compounds at operating voltage range. Linear sweep voltammetry of graphite with addition of sulfur compounds exhibited enhanced current density compared to pure graphite electrooxidation. Chronoamperometry was carried out to examine steady-state test of graphite electrooxidation in presence of sulfur compounds and the results indicated the enhanced current densities were caused by improved Boudouard reaction for CaSO4 and sulfur electrooxidation for other compounds, respectively. These inorganic sulfur compounds had no impact on electrooxidation process of graphite.

  9. Transformations of sulfur compounds in marsh-flat sediments

    SciTech Connect

    Swider, K.T.; Mackin, J.E. )

    1989-09-01

    Measurements were made in mud-flat sediments from Flax Pond salt marsh to characterize the rates and mechanisms of sulfur cycling in an organic-rich coastal marine environment. Approximately 13 mmoles/m{sup 2} of reduced sulfur are generated annually in the mud flat and the dominant solid-phase product is pyrite. Ion activity products involving dissolved iron and sulfide species indicate approximate saturation with respect to metastable iron sulfide phases, showing that pyrite is not likely to be the first-formed Fe-bearing sulfide. Comparison of {Sigma}H{sub 2}S vs. SO{sup =}{sub 4} relationships in anoxic incubation experiments with those occurring in the undisturbed sediment permits evaluation of possible mechanisms involved in the transformation of metastable iron monosulfides to pyrite. Oxidants (e.g. MnO{sub 2}) that are introduced into the surface sediment, either by animal activity or physical events, are apparently necessary to cause major oxidation of FeS and {Sigma}H{sub 2}S to pyrite and sulfate. Solid-phase sulfur analyses and net {Sigma}H{sub 2}S accumulation in sediment pore waters are consistent with major sulfide oxidation, indicating that approximately 95% of the sulfide generated in the mud flat is reoxidized to sulfate and roughly half of this oxidation involves dissolved sulfide. The major factors limiting reduced sulfur burial are physical and biological disturbances and a low abundance of reactive solid-phase iron (2 wt%).

  10. BIOGENIC SULFUR COMPOUNDS IN COASTAL ATMOSPHERES OF NORTH CAROLINA

    EPA Science Inventory

    Atmospheric H2S, SO2, and particulate SO4(-2), Na(+), C1(-), NH4(-), and NO3(-) were measured in two experiments on the North Carolina coast to determine the levels of biogenic sulfur species at marsh and estuarine locations where dissimilatory bacterial sulfate reduction produce...

  11. Thermochemical Data on Gas Phase Compounds of Sulfur, Fluorine, Oxygen, and Hydrogen Related to Pyrolysis and Oxidation of Sulfur Hexafluoride

    NASA Astrophysics Data System (ADS)

    Herron, John T.

    1987-01-01

    Thermochemical data on selected gas phase compounds containing sulfur, fluorine, oxygen, and hydrogen are evaluated. These are of particular relevance to plasma chemistry and SF6 dielectric breakdown. Values of the enthalpies of formation and the entropy are provided at 298 K. Where no experimental data are available, methods for estimation have been developed for deriving the enthalpy of formation. Data are tabulated for 36 substances.

  12. A STUDY TO IMPROVE EPA METHODS 15 AND 16 FOR REDUCED SULFUR COMPOUNDS

    EPA Science Inventory

    EPA source test methods for reduced sulfur compounds, Method 15 for Claus sulfur recovery plants and Method 16 for Kraft pulp mills have been evaluated, and information is provided for the user. Techniques and procedures for the gas chromatographic measurement of hydrogen sulfide...

  13. Photochemistry of reduced sulfur compounds in a landfill environment

    NASA Astrophysics Data System (ADS)

    Shon, Zang-Ho; Kim, Ki-Hyun; Jeon, Eui-Chan; Kim, Min-Young; Kim, Yoo-Keun; Song, Sang-Keun

    This study examines the distribution characteristics of reduced sulfur compounds (RSCs such as DMS, CS 2, H 2S, DMDS, and CH 3SH) and their photochemical reactions in landfill air. The photochemical conversions of RSCs to a further oxidized form, SO 2 were evaluated in the landfill site using a photochemical box model. Measurements of RSCs were carried out from landfill areas in Daegu, Korea, during a wintertime period (e.g., 13-16 Jan 2004). This study indicated that H 2S was the most dominant RSC in the landfill, with the concentrations of 4.2±5.8 ppbv. The chemical species of RSCs, which may exert influences on the SO 2 production depending on sampling conditions, were found to include DMS, DMDS, and H 2S. In general, the RSC contribution to the observed SO 2 levels was insignificant in the sampling sites investigated. Overall, the extent of the RSC oxidation to the observed SO 2 varied dramatically during the sampling period. The photochemical conversion of the RSCs in the landfill environment can account for about 15% of the observed SO 2, on average. There was a strong correlation between DMS and SO 2 concentration levels during the study period.

  14. Metal phosphate reduction in the presence of gaseous sulfur compounds

    SciTech Connect

    Kriklivyi, D.I.; Klimovich, M.A.; Petrovskaya, N.A.

    1992-05-20

    The phosphorus used for combining with calcium oxide is usually obtained by means of thermally stable acidic or amphoteric oxide additives, i.e., almost only silicon dioxide, aluminum oxide, and aluminum silicate. The reduction of tricalcium phosphate and natural calcium phosphate ores by natural gas in the presence of such additives at an acidity coefficient (C{sub a}) of 1 may be brought to completion in 1-3 h. Increasing the C{sub a} of a charge to 1.5-3 facilitates solid-phase reduction of low-melting phosphate ores and raises the phosphorus vaporization rate. However solid-phase additives in the phosphate and their high consumption increase charge preparation cost and lower equipment efficiency. The purpose of this paper is to study a replacement of solid-phase fluxes by volatiles that can combine with basic oxides. This approach was examined theoretically as to the possibility of replacing solid-phase fluxes by hydrogen chloride and volatile sulfur compounds. The latter is often found in natural gases that could be used in the phosphorus industry without prior purification. 15 refs., 3 figs., 3 tabs.

  15. Evolution of Volatile Sulfur Compounds during Wine Fermentation.

    PubMed

    Kinzurik, Matias I; Herbst-Johnstone, Mandy; Gardner, Richard C; Fedrizzi, Bruno

    2015-09-16

    Volatile sulfur compounds (VSCs) play a significant role in the aroma of foods and beverages. With very low sensory thresholds and strong unpleasant aromas, most VSCs are considered to have a negative impact on wine quality. In this study, headspace solid phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME/GC-MS) was used to analyze the time course of the biosynthesis of 12 VSCs formed during wine fermentation. Two different strains of Saccharomyces cerevisiae, the laboratory strain BY4743 and a commercial strain, F15, were assessed using two media: synthetic grape media and Sauvignon Blanc juice. Seven VSCs were detected above background, with three rising above their sensory thresholds. The data revealed remarkable differences in the timing and evolution of production during fermentation, with a transient spike in methanethiol production early during anaerobic growth. Heavier VSCs such as benzothiazole and S-ethyl thioacetate were produced at a steady rate throughout grape juice fermentation, whereas others, such as diethyl sulfide, appear toward the very end of the winemaking process. The results also demonstrate significant differences between yeast strains and fermentation media. PMID:26271945

  16. Synthesis of organic sulfur compounds by means of silicon-containing reagents

    SciTech Connect

    Mizhiritskii, M.D.; Reikhsfel'd, V.O.

    1987-01-10

    The reaction of alkoxy-, amino-, and thiosilanes with halo (pseudohalo) derivatives of sulfur, as well as the reactions of organosilicon derivatives of hydrogen sulfide, mercaptans, and sulfonic acids with halogen-containing organic compounds proceed via mechanisms of the exchange type; organic derivatives of sulfur and low-boiling silicon compounds (trimethylhalo- and N,N-dimethylaminosilanes and hexamethyldisiloxane) are formed in high yields. These reactions can serve as convenient methods for the preparation of a number of sulfur compounds that are difficult to obtain. Hexamethyldisilthiane can be used as a reducing agent for sulfoxides and sulfines, as well as their selenium analogs.

  17. Microbial removal of organic sulfur from coal (bacterial degradation of sulfur-containing heterocyclic compounds): Final report, March 1, 1986-February 28, 1987. [Thiobacillus

    SciTech Connect

    Klubek, B.; Clark, D.

    1987-05-01

    The presence of substantial levels of sulfur in coal is a major source of air pollution, and considerable efforts are being made to devise an inexpensive way of removing the sulfur. One promising method is microbial desulfurization. Almost all of the inorganic sulfur can be removed from coal by the bacteria Thiobacillus or Sulfolobus, which convert sulfide to sulfate but leave the organic sulfur untouched. Certain coals, including those in the Illinois Basin, contain high levels of organic sulfur, especially thiophenes; hence, removal of organic sulfur is also necessary. If strains of bacteria are developed which remove organic sulfur from coal and are used in conjunction with inorganic sulfur-oxidizing bacteria, the result should be an effective desulfurization method. We are using two approaches to develop bacteria which remove organic sulfur. One method is to mutate Escherichia coli, an organism which is genetically well-understood. Thiophene degraders have been isolated from E. coli and genetically analyzed. Mutations in three novel genes, thdA (12 min), thdC (92 min), and thdD (98 min) were required for thiophene degradation. Constitutive mutations at the previously characterized fadR and atoC loci were also required. The second approach is the isolation of naturally occurring bacteria capable of thiophene degradation by enrichment culture techniques. The degradation rates of thiophene model compounds indicate the potential for desulfurization. Ultimately, the best characteristics of the natural isolates will be cloned into the thiophene-degrading E. coli to yield an improved organic sulfur degrader.

  18. Microbial removal of organic sulfur from coal (bacterial degradation of sulfur-containing heterocyclic compounds): Final report, July 1, 1985-February 28, 1986

    SciTech Connect

    Klubek, B.; Clark, D.

    1986-05-01

    The presence of substantial levels of sulfur in coal is a major source of air pollution, and considerable afforts are being made to devise a cost-effective way of removing the sulfur. One promising method is the microbial desulfurization of coal. Recent research has shown that it is possible to remove almost all of the inorganic sulfur from coal using the bacteria Thiobacillus or Sulfolobus. These organisms convert sulfide to sulfate but leave the organic sulfur untouched. Certain coals, including those in the Illinois Basin, contain high levels of organic sulfur; therefore, removal of organic sulfur is also necessary. If a strain of bacteria which would effectively remove organic sulfur from coal could be found or developed and used in conjunction with an organism which removes inorganic sulfur, the result could be an effective desulfurization method. Several approaches were used in developing bacteria which remove organic sulfur. One method was to mutate a laboratory species, Escherichia coli, an organism which is genetically well-understood and whose pathways for the metabolism of sulfur-containing amino-acids have been extensively investigated. Such thiophene degraders have benn isolated and are currently being analyzed for the genes involved. The second approach is the continued development of natuarlly occurring bacteria capable of degradation using enrichment culture techniques. The degradation rates of the thiophene model compounds indexed the potential for desulfurization. 10 refs., 4 figs., 8 tabs.

  19. Lithium Polysulfidophosphates: A Family of Lithium-Conducting Sulfur-Rich Compounds for Lithium-Sulfur Batteries

    SciTech Connect

    Lin, Zhan; Liu, Zengcai; Fu, Wujun; Dudney, Nancy J; Liang, Chengdu

    2013-01-01

    Given the great potential for improving the energy density of state-of-the-art lithium-ion batteries by a factor of 5, a breakthrough in lithium-sulfur (Li-S) batteries will have a dramatic impact in a broad scope of energy related fields. Conventional Li-S batteries that use liquid electrolytes are intrinsically short-lived with low energy efficiency. The challenges stem from the poor electronic and ionic conductivities of elemental sulfur and its discharge products. We report herein lithium polysulfidophosphates (LPSP), a family of sulfur-rich compounds, as the enabler of long-lasting and energy-efficient Li-S batteries. LPSP have ionic conductivities of 3.0 10-5 S cm-1 at 25 oC, which is 8 orders of magnitude higher than that of Li2S (~10-13 S cm-1). The high Li-ion conductivity of LPSP is the salient characteristic of these compounds that impart the excellent cycling performance to Li-S batteries. In addition, the batteries are configured in an all-solid state that promises the safe cycling of high-energy batteries with metallic lithium anodes.

  20. Kinase regulation by sulfur and selenium containing compounds.

    PubMed

    Sanmartín, Carmen; Plano, Daniel; Font, María; Palop, Juan Antonio

    2011-05-01

    Kinases are enzymes that are involved in a wide-range of cellular targets such as cell proliferation, metabolism, survival and apoptosis. Aberrations in the activity of the kinases have been linked to many human diseases such as diabetes, inflammation and cancer. The discovery of more than 518 kinases encoded by the human genome has spurred the development of rapid screening techniques for potential drugs against these enzymes and these have been identified as interesting targets for medicinal chemistry programs, especially in cancer therapy. On the other hand, sulfur and selenium have been increasingly recognized as essential elements in biology and medicine. Converging data from epidemiological and clinical studies have highlighted these elements as effective chemopreventive agents, particularly against various types of cancer (prostate, lung, breast, leukemia, colon, skin, lymphome, thyroid, pancreas, liver). These elements act through a wide range of potential mechanisms where one identified signal pathway event is kinase modulation, which is common for the two elements and emerges as a valid target. The kinases modulated by sulfur and selenium derivatives include MAP, ERK, JNK, Akt, Cdc2, Cyclin B1 and Cdc25c amongst others. Although both of the elements in question are in the same group in the periodic table and have similar biochemistries, there are relevant differences related to redox potentials, stabilities, oxidation states and anticancer activity. Literature data suggest that the replacement of sulfur by selenium in established cancer chemopreventive agents results in more effective chemopreventive analogs. In view of the multi-target kinase mechanisms in preventing cellular transformation, as well as the differences and similarities between them, in this review we focus on the development of new structures that contain selenium and/or sulfur and discuss our understanding of the regulation of antitumoral effects with emphasis on kinase modulation activity and its implications in cancer. PMID:21395545

  1. Liquid-vapor equilibrium under elevated pressures in the systems formed by pentanes with sulfur compounds

    SciTech Connect

    Shakirzyanov, R.G.; Telyakov, E.S.; Serafimov, L.A.

    1982-10-20

    The possibility of removing sulfur compounds from the pentane fraction was studied. Experimental data obtained on liquid-vapor equilibrium in the system formed by pentanes with sulfur compounds under elevated pressures is presented. Vapor-liquid equilibrium was studied with the aid of a modified Swietoslawski apparatus made of stainless steel. Experimental data on phase equilibria of binary mixtures in the system studied are presented. The compositions and boiling points of binary azeotropes at the pressures studied are also presented.

  2. Transition metal-mediated desulfurization of aromatic sulfur compounds

    SciTech Connect

    Eisch, J.J.; Im, K.R.; Hallenbeck, L.E.

    1980-01-01

    In a study concerning energy-efficient ways of cleaving organic sulfur bonds in coal, petroleum, or their derived liquids, dibenzothiophene, phenoxathiin, phenothiazine, thianthrene, and various open-chain aryl sulfides and mercaptans were reacted with 2,2'-bipyridyl in (1,5-cyclooctadiene) nickel(O) in tetrahydrofuran solution at, e.g., 40/sup 0/-70/sup 0/C, and the reaction mixtures were worked up with glacial acetic acid or with lithium aluminum hydride. The reaction mechanisms are discussed.

  3. Effects of inhibitors and NaCl on the oxidation of reduced inorganic sulfur compounds by a marine acidophilic, sulfur-oxidizing bacterium, Acidithiobacillus thiooxidans strain SH.

    PubMed

    Kamimura, Kazuo; Higashino, Emi; Kanao, Tadayoshi; Sugio, Tsuyoshi

    2005-02-01

    The effect of NaCl and the pathways of the oxidation of reduced inorganic sulfur compounds were studied using resting cells and cell-free extracts of Acidithiobacillus thiooxidans strain SH. This isolate specifically requires NaCl for growth. The oxidation of sulfur and sulfite by resting cells was strongly inhibited by 2-heptyl-4-hydroxyquinoline-N-oxide. Carbonylcyanide m-chlorophenyl-hydrazone and monensin were also relatively strong inhibitors. Thiosulfate-oxidizing activity was not inhibited by these uncouplers. Valinomycin did not inhibit the oxidation of sulfur compounds. NaCl stimulated the sulfur- and sulfite-oxidizing activities in resting cells but not in cell-free extracts. The tetrathionate-oxidizing activity in resting cells was slightly stimulated by NaCl, whereas it did not influence the thiosulfate-oxidizing activity. Sulfide oxidation was biphasic, suggesting the formation of intermediate sulfur. The initial phase of sulfide oxidation was not affected by NaCl, whereas the subsequent oxidation of sulfur in the second phase was Na+-dependent. A model is proposed for the role of NaCl in the metabolism of reduced sulfur compounds in A. thiooxidans strain SH. PMID:15375674

  4. Ab initio study of hypervalent sulfur hydrides as model intermediates in the interconversion reactions of compounds containing sulfur-sulfur bonds

    SciTech Connect

    Laitinen, R.S.; Pakkanen, T.A.; Steudel, R.

    1987-02-04

    Ab initio MO calculations involving the 4-31G* basis set have been used to predict the equilibrium geometries of the hypervalent sulfur hydrides H/sub 2/SS, (HS)/sub 2/SS, H/sub 2/S(SH)/sub 2/, H/sub 2/S(SSH)/sub 2/, and the cyclic H/sub 4/S/sub 4/. The energy changes in their formation from appropriate sulfanes H/sub 2/S/sub n/ (n = 1-4) have been studied with the 6-31G* basis set including the correction for the electron correlation by the second- and third-order Moeller-Plesset perturbation theory. The results are used to discuss the possible pathways in the interconversion reactions between various sulfur compounds containing cumulated SS bonds, for example, the formation of S/sub 7/ from S/sub 8/ for which hypervalent intermediates have been proposed recently. Comparison with experimental evidence is made whenever possible.

  5. Oxidation of refractory sulfur compounds over Ti-containing mesoporous molecular sieves prepared by using a fluorosilicon compound.

    PubMed

    Jeong, Kwang-Eun; Cho, Chin-Soo; Chae, Ho-Jeong; Kim, Chul-Ung; Jeong, Soon-Yong

    2010-05-01

    Titanium containing mesoporous molecular sieve (Ti-MMS) catalysts were studied for the oxidative desulfurization of refractory sulfur compounds. Ti-MMS catalysts were synthesized from fluorosilicon compounds and Ti with the hydrolysis reaction of H2SiF6 in an ammonia-surfactant mixed solution. The solid products were characterized by XRD, XRF, nitrogen adsorption, and diffuse reflectance UV-vis spectroscopy. Effects of Ti loading and oxidant/sulfur mole ratio, and sulfur species on ODS activity were investigated. PMID:20358997

  6. Use of reduced sulfur compounds by Beggiatoa sp.

    PubMed Central

    Nelson, D C; Castenholz, R W

    1981-01-01

    A strain of Beggiatoa cf. leptomitiformis (OH-75-B, clone 2a) was isolated which is unique among reported strains in its ability to deposit internal sulfur granules from thiosulfate. It also deposited these characteristic granules (as all BEggiatoa species do) from sulfide. In cultures where growth was limited by exhaustion of organic substrates, these granules generally comprised about 20% of the total cell weight. With medium containing acetate and thiosulfate, no measurable utilization of thiosulfate or deposition of elemental sulfur (S0) took place until after the exponential growth phase. Neither sulfide nor thiosulfate added an increment to heterotrophic growth yield except for the weight of the deposited S0. The deposition of S0 from thiosulfate was probably a disproportionation in which S0 and sulfate were produced in a 1:1 ratio. Some of the S0 was further oxidized to sulfate. No autotrophic or mixotrophic growth was demonstrated for this strain. When inoculated in small, well-dispersed quantities into yeast extract medium, this strain grew only after long lags. Addition of the enzyme catalase eliminated initial lags and increased growth rates slightly. In contrast, catalase had no influence on growth rate when added to mineral medium containing acetate. In yeast extract medium, the inhibition of growth rate was presumably because of peroxides. Addition of thiosulfate was almost as effective as catalase in eliminating this inhibition. The S0 granules which, in this case, were deposited during the exponential growth phase, appeared to be partly responsible for this relief. This strain of Beggiatoa sp. remained active for at least 5 days under strictly anaerobic conditions, and under those conditions, it increased its dry weight by about 2.5-fold. Anaerobic "growth" and maintenance required the presence of an energy source, such as acetate. When cells containing much internal S0 were transferred to an organic anaerobic medium, a substantial portion of the internal S0 was eventually converted to sulfide. PMID:7240091

  7. Flash pyrolysis of coal, coal maceral, and coal-derived pyrite with on-line characterization of volatile sulfur compounds

    USGS Publications Warehouse

    Chou, I.-Ming; Lake, M.A.; Griffin, R.A.

    1988-01-01

    A Pyroprobe flash pyrolysis-gas chromatograph equipped with a flame photometric detector was used to study volatile sulfur compounds produced during the thermal decomposition of Illinois coal, coal macerals and coal-derived pyrite. Maximum evolution of volatile organic sulfur compounds from all coal samples occurred at a temperature of approximately 700??C. At this temperature, the evolution of thiophene, its alkyl isomers, and short-chain dialkyl sulfide compounds relative to the evolution of benzothiophene and dibenzothiophene compounds was greater from coal high in organic sulfur than from coal low in organic sulfur. The variation in the evolution of sulfur compounds observed for three separate coal macerals (exinite, vitrinite, and inertinite) was similar to that observed for whole coal samples. However, the variation trend for the macerals was much more pronounced. Decomposition of coal-derived pyrite with the evolution of elemental sulfur was detected at a temperature greater than 700??C. The results of this study indicated that the gas chromotographic profile of the volatile sulfur compounds produced during flash pyrolysis of coals and coal macerals varied as a function of the amount of organic sulfur that occurred in the samples. Characterization of these volatile sulfur compounds provides a better understanding of the behavior of sulfur in coal during the thermolysis process, which could be incorporated in the design for coal cleaning using flash pyrolysis techniques. ?? 1988.

  8. High-Pressure Iron-Sulfur Compounds and their Implications for the Mineralogy of the Sulfur-Bearing Iron Cores

    NASA Astrophysics Data System (ADS)

    Koch-Müller, M.; Fei, Y.; Wirth, R.; Bertka, C. M.

    2003-04-01

    Sulfur is considered to be the possible light element that alloys with iron in the terrestrial planetary cores. Prior to 1997, end-members Fe and FeS are used to model the cores because no intermediate compounds between Fe and FeS were found. Recent high-pressure experiments revealed that at least three new iron-sulfur compounds, Fe3S2, Fe2S, and Fe3S, were formed at high pressures [Fei et al. Science 275, 1621-1623, 1997; Fei et al. Am. Mineral. 85, 1830-1833, 2000]. Because the physical properties of a planetary core are governed by its mineralogy, it is essential to fully characterize these compounds. We synthesized Fe3S,Fe3S2 and Fe2S iron-sulfur compounds at 22 GPa and 950 to 1050 oC and characterized them by X-ray powder diffraction, electron microprobe analyses and transmission electron microscopy. Fe3S is a quenchable phase in the Fe-S system. It is isostructural with Cr3P. The X-ray diffraction patterns for the Fe3S2 and Fe2S samples are complicated and cannot be indexed with a single phase. TEM and X-ray diffraction measurements show that the samples are extremely fine grained and multi phase products. Fe2S exists as a phase in the Fe-S system, but it is unstable at ambient condition. The TEM measurements revealed that it decomposes to Fe3S and FeS. However, the Fe2S phase was partially survived during quenching. X-ray diffraction data indicated that Fe2S exists in two polymorphs. Both polymorphs have the hexagonal cell. Their possible structure analogs are Ti2P and Fe2P. The Fe3S2 phase is of non-stoichiometric nature. The exact composition of the Fe3S2 phase synthesized in this study is close to Fe3.2S2. It is isostructural with TiP0.63 (=Ti3.18P2). During quenching it partially decomposes to FeS and Fe2S. The stability fields and the structures of the Fe2S and Fe3.2S2 phases need to be further investigated by in-situ measurements. From the TEM measurements, we also found single crystals of cubic Fe2S3 in the quenched Fe3.2S2 sample. However, the quantity of this phase is very small (1 wt% based on the quantitative phase analysis).

  9. Zeolites Remove Sulfur From Fuels

    NASA Technical Reports Server (NTRS)

    Voecks, Gerald E.; Sharma, Pramod K.

    1991-01-01

    Zeolites remove substantial amounts of sulfur compounds from diesel fuel under relatively mild conditions - atmospheric pressure below 300 degrees C. Extracts up to 60 percent of sulfur content of high-sulfur fuel. Applicable to petroleum refineries, natural-gas processors, electric powerplants, and chemical-processing plants. Method simpler and uses considerably lower pressure than current industrial method, hydro-desulfurization. Yields cleaner emissions from combustion of petroleum fuels, and protects catalysts from poisoning by sulfur.

  10. Spectral reflectance (0.4 - 5.0 microns) of sulfur related compounds and mixtures

    NASA Technical Reports Server (NTRS)

    Gradie, Jonathan C.

    1987-01-01

    Studied and quantified were: (1) the spectral properties of sulfur related compounds and materials; (2) the effects of thermal history, temperature and mixing ratios on the spectral properties of these materials; and (3) the application of these results to the Jovian system, in particular, the surfaces of Io, Europa, and Amalthea, and the chromophores in the Jovian atmosphere. Major results of the study include: (1) a study of how sulfur deposition affects the band strengths in various silicates; (2) a study of how the ultraviolet absorption band of sulfur is affected by dilution in ice; (3) the application of these two sets of experimental studies to Io, in the case of silicate band strengths, and Europa, as in the case of sulfur dilution in ices.

  11. Anti-Inflammatory Activity of Sulfur-Containing Compounds from Garlic

    PubMed Central

    Lee, Da Yeon; Li, Hua; Lim, Hyo Jin; Lee, Hwa Jin; Jeon, Raok

    2012-01-01

    Abstract We identified four anti-inflammatory sulfur-containing compounds from garlic, and their chemical structures were identified as Z- and E-ajoene and oxidized sulfonyl derivatives of ajoene. The sulfur compounds inhibited the production of nitric oxide (NO) and prostaglandin E2 (PGE2) and the expression of the pro-inflammatory cytokines tumor necrosis factor-?, interleukin-1?, and interleukin-6 in lipopolysaccharide (LPS)-activated macrophages. Western blotting and reverse transcriptionpolymerase chain reaction analysis demonstrated that these sulfur compounds attenuated the LPS-induced expression of the inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins and mRNA. Moreover, these sulfur-containing compounds suppressed the nuclear factor-?B (NF-?B) transcriptional activity and the degradation of inhibitory-?B? in LPS-activated macrophages. Furthermore, we observed that they markedly inhibited the LPS-induced phosphorylations of p38 mitogen-activated protein kinases and extracellular signal-regulated kinases (ERK) at 20??M. These data demonstrate that the sulfur compounds from garlic, (Z, E)-ajoene and their sulfonyl analogs, can suppress the LPS-induced production of NO/PGE2 and the expression of iNOS/COX-2 genes by inhibiting the NF-?B activation and the phosphorylations of p38 and ERK. Taken together, these data show that Z- and E-ajoene and their sulfonyl analogs from garlic might have anti-inflammatory therapeutic potential. PMID:23057778

  12. Air/water oxidative desulfurization of coal and sulfur-containing compounds

    NASA Astrophysics Data System (ADS)

    Warzinski, R. P.; Freidman, S.; LaCount, R. B.

    1981-02-01

    Air/water Oxydesulfurization has been demonstrated in autoclave experiments at the Pittsburgh Energy Technology Center for various coals representative of the major U. S. coal basins. The applicability at present of this treatment for producing an environmentally acceptable coal has been restricted by recently proposed SO2 emission standards for utility boilers. The product would, however, be attractive to the many smaller industrial coal users who cannot afford to operate and maintain flue gas desulfurization systems. It is also possible that the utility industry could realize a benefit by using chemically cleaned coal with partial flue gas scrubbing. The higher cost of the cleaned coal would be offset by the reduction in capital and operating costs resulting from decreased FGD requirements. The susceptibility of sulfur in coal to oxidative removal varies with the nature of the sulfur-containing species. The inorganic sulfur compounds, primarily pyrite, marcasite, and iron sulfate, are more amenable to treatment than the organically bound sulfur which exhibits varying degrees of resistance depending on its chemical environment. Air/water Oxydesulfurization consistently removes in excess of 90 percent of the pyritic sulfur; the extent and efficiency of organic sulfur removal however, depends on the type of coal and severity of treatment used. In general, the organic sulfur of the higher rank coals exhibits more resistance to treatment than that of the lower rank coals; however, the accompanying heating value is greater for the latter. Similar treatment of sulfur-containing model compounds further illustrates the relative susceptibilities of different chemical species to oxidation. Application of these data to the understanding of the complex chemistry involved in the treatment of coal is a preliminary step toward improving the efficiency of Oxydesulfurization.

  13. Online air analysis of reduced sulfur compounds at a swine facility

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reduced sulfur compounds are emitted from waste management handling and can be important in odor production and atmospheric chemistry. Data on the emissions of these compounds have been obtained using off-line sampling and analysis methods, but on-line methods providing information on temporal chang...

  14. Production of Volatile and Sulfur Compounds by 10 Saccharomyces cerevisiae Strains Inoculated in Trebbiano Must.

    PubMed

    Patrignani, Francesca; Chinnici, Fabio; Serrazanetti, Diana I; Vernocchi, Pamela; Ndagijimana, Maurice; Riponi, Claudio; Lanciotti, Rosalba

    2016-01-01

    In wines, the presence of sulfur compounds is the resulting of several contributions among which yeast metabolism. The characterization of the starter Saccharomyces cerevisiae needs to be performed also taking into account this ability even if evaluated together with the overall metabolic profile. In this perspective, principal aim of this experimental research was the evaluation of the volatile profiles, throughout GC/MS technique coupled with solid phase micro extraction, of wines obtained throughout the fermentation of 10 strains of S. cerevisiae. In addition, the production of sulfur compounds was further evaluated by using a gas-chromatograph coupled with a Flame Photometric Detector. Specifically, the 10 strains were inoculated in Trebbiano musts and the fermentations were monitored for 19 days. In the produced wines, volatile and sulfur compounds as well as amino acid concentrations were investigated. Also the physico-chemical characteristics of the wines and their electronic nose profiles were evaluated. PMID:26973621

  15. Production of Volatile and Sulfur Compounds by 10 Saccharomyces cerevisiae Strains Inoculated in Trebbiano Must

    PubMed Central

    Patrignani, Francesca; Chinnici, Fabio; Serrazanetti, Diana I.; Vernocchi, Pamela; Ndagijimana, Maurice; Riponi, Claudio; Lanciotti, Rosalba

    2016-01-01

    In wines, the presence of sulfur compounds is the resulting of several contributions among which yeast metabolism. The characterization of the starter Saccharomyces cerevisiae needs to be performed also taking into account this ability even if evaluated together with the overall metabolic profile. In this perspective, principal aim of this experimental research was the evaluation of the volatile profiles, throughout GC/MS technique coupled with solid phase micro extraction, of wines obtained throughout the fermentation of 10 strains of S. cerevisiae. In addition, the production of sulfur compounds was further evaluated by using a gas-chromatograph coupled with a Flame Photometric Detector. Specifically, the 10 strains were inoculated in Trebbiano musts and the fermentations were monitored for 19 days. In the produced wines, volatile and sulfur compounds as well as amino acid concentrations were investigated. Also the physico-chemical characteristics of the wines and their electronic nose profiles were evaluated. PMID:26973621

  16. Sulfur/lithium-insertion compound composite cathodes for Li-S batteries

    NASA Astrophysics Data System (ADS)

    Su, Yu-Sheng; Manthiram, Arumugam

    2014-12-01

    A part of carbon additives in sulfur cathodes is replaced by lithium-insertion compounds as they can contribute extra capacity and increase the overall energy density. Accordingly, VO2(B) and TiS2 were incorporated into sulfur cathodes as they can work within the same voltage window as that of sulfur. However, VO2(B) was found to be incompatible with the glyme-based electrolytes that are usually used in Li-S cells, but TiS2 performs well while coupled with sulfur. The S/C/TiS2 composite cathode delivers 252 mAh g-1 more than that of pristine sulfur cathode (1334 mAh g-1 vs. 1082 mAh g-1). The increased capacity is not only due to the contribution by TiS2 itself but also due to a better active-material dispersion and utilization. Serving as active reaction sites during cycling, TiS2 suppresses agglomeration of sulfur and facilitates better ionic/electronic transport within the cathode structure. This composite cathode design provides another direction for Li-S batteries to improve the overall energy density.

  17. Stoichiometric modeling of oxidation of reduced inorganic sulfur compounds (Riscs) in Acidithiobacillus thiooxidans.

    PubMed

    Bobadilla Fazzini, Roberto A; Cortés, Maria Paz; Padilla, Leandro; Maturana, Daniel; Budinich, Marko; Maass, Alejandro; Parada, Pilar

    2013-08-01

    The prokaryotic oxidation of reduced inorganic sulfur compounds (RISCs) is a topic of utmost importance from a biogeochemical and industrial perspective. Despite sulfur oxidizing bacterial activity is largely known, no quantitative approaches to biological RISCs oxidation have been made, gathering all the complex abiotic and enzymatic stoichiometry involved. Even though in the case of neutrophilic bacteria such as Paracoccus and Beggiatoa species the RISCs oxidation systems are well described, there is a lack of knowledge for acidophilic microorganisms. Here, we present the first experimentally validated stoichiometric model able to assess RISCs oxidation quantitatively in Acidithiobacillus thiooxidans (strain DSM 17318), the archetype of the sulfur oxidizing acidophilic chemolithoautotrophs. This model was built based on literature and genomic analysis, considering a widespread mix of formerly proposed RISCs oxidation models combined and evaluated experimentally. Thiosulfate partial oxidation by the Sox system (SoxABXYZ) was placed as central step of sulfur oxidation model, along with abiotic reactions. This model was coupled with a detailed stoichiometry of biomass production, providing accurate bacterial growth predictions. In silico deletion/inactivation highlights the role of sulfur dioxygenase as the main catalyzer and a moderate function of tetrathionate hydrolase in elemental sulfur catabolism, demonstrating that this model constitutes an advanced instrument for the optimization of At. thiooxidans biomass production with potential use in biohydrometallurgical and environmental applications. PMID:23436458

  18. Genomic Analysis Unravels Reduced Inorganic Sulfur Compound Oxidation of Heterotrophic Acidophilic Acidicaldus sp. Strain DX-1

    PubMed Central

    Liu, Yuanyuan; Yang, Hongying; Zhang, Xian; Xiao, Yunhua; Guo, Xue; Liu, Xueduan

    2016-01-01

    Although reduced inorganic sulfur compound (RISC) oxidation in many chemolithoautotrophic sulfur oxidizers has been investigated in recent years, there is little information about RISC oxidation in heterotrophic acidophiles. In this study, Acidicaldus sp. strain DX-1, a heterotrophic sulfur-oxidizing acidophile, was isolated. Its genome was sequenced and then used for comparative genomics. Furthermore, real-time quantitative PCR was performed to identify the expression of genes involved in the RISC oxidation. Gene encoding thiosulfate: quinone oxidoreductase was present in Acidicaldus sp. strain DX-1, while no candidate genes with significant similarity to tetrathionate hydrolase were found. Additionally, there were genes encoding heterodisulfide reductase complex, which was proposed to play a crucial role in oxidizing cytoplasmic sulfur. Like many heterotrophic sulfur oxidizers, Acidicaldus sp. strain DX-1 had no genes encoding enzymes essential for the direct oxidation of sulfite. An indirect oxidation of sulfite via adenosine-5′-phosphosulfate was proposed in Acidicaldus strain DX-1. However, compared to other closely related bacteria Acidiphilium cryptum and Acidiphilium multivorum, which harbored the genes encoding Sox system, almost all of these genes were not detected in Acidicaldus sp. strain DX-1. This study might provide some references for the future study of RISC oxidation in heterotrophic sulfur-oxidizing acidophiles.

  19. Low Temperature Sorbents for Removal of Sulfur Compounds from Fluid Feed Streams

    DOEpatents

    Siriwardane, Ranjani

    2004-06-01

    A sorbent material is provided comprising a material reactive with sulfur, a binder unreactive with sulfur and an inert material, wherein the sorbent absorbs the sulfur at temperatures between 30 and 200 C. Sulfur absorption capacity as high as 22 weight percent has been observed with these materials.

  20. Sulfuric acid-sulfur heat storage cycle

    DOEpatents

    Norman, John H.

    1983-12-20

    A method of storing heat is provided utilizing a chemical cycle which interconverts sulfuric acid and sulfur. The method can be used to levelize the energy obtained from intermittent heat sources, such as solar collectors. Dilute sulfuric acid is concentrated by evaporation of water, and the concentrated sulfuric acid is boiled and decomposed using intense heat from the heat source, forming sulfur dioxide and oxygen. The sulfur dioxide is reacted with water in a disproportionation reaction yielding dilute sulfuric acid, which is recycled, and elemental sulfur. The sulfur has substantial potential chemical energy and represents the storage of a significant portion of the energy obtained from the heat source. The sulfur is burned whenever required to release the stored energy. A particularly advantageous use of the heat storage method is in conjunction with a solar-powered facility which uses the Bunsen reaction in a water-splitting process. The energy storage method is used to levelize the availability of solar energy while some of the sulfur dioxide produced in the heat storage reactions is converted to sulfuric acid in the Bunsen reaction.

  1. Uptake of Small Organic Compounds by Sulfuric Acid Aerosols: Dissolution and Reaction

    NASA Technical Reports Server (NTRS)

    Iraci, L. T.; Michelsen, R. R.; Ashbourn, S. F. M.; Staton, S. J. R.

    2003-01-01

    To assess the role of oxygenated volatile organic compounds in the upper troposphere and lower stratosphere, the interactions of a series of small organic compounds with low-temperature aqueous sulfuric acid will be evaluated. The total amount of organic material which may be taken up from the gas phase by dissolution, surface layer formation, and reaction during the particle lifetime will be quantified. Our current results for acetaldehyde uptake on 40 - 80 wt% sulfuric acid solutions will be compared to those of methanol, formaldehyde, and acetone to investigate the relationships between chemical functionality and heterogeneous activity. Where possible, equilibrium uptake will be ascribed to component pathways (hydration, protonation, etc.) to facilitate evaluation of other species not yet studied in low temperature aqueous sulfuric acid.

  2. Stimulation of proinflammatory cytokines by volatile sulfur compounds in endodontically treated teeth

    PubMed Central

    Lechner, Johann; von Baehr, Volker

    2015-01-01

    Persistent microorganisms in endodontically treated teeth produce volatile sulfur compounds (VSC) such as methyl mercaptan, hydrogen sulfide, and thioether. In this retrospective study, we evaluated the ex vivo immune response of peripheral blood mononuclear cells to sulfur compounds in 354 patients with systemic diseases. These systemic findings are correlated with semiquantitative values of a VSC indicator applied directly on endodontically treated teeth. Data elucidate the role of VSC in patients with immunologic diseases and the role of a semiquantitative chairside test, like the VSC indicator presented here, in correlation to IFNg and IL-10 sensitization in peripheral blood mononuclear cells. The association between ex vivo-stimulated cytokines and endodontically derived sulfur components is supported by the fact that the number of interferon gamma- and/or interleukin-10-positive sensitized patients declined significantly 3–8 months after extraction of the corresponding teeth. PMID:25792853

  3. Reevaluating the contribution of sulfuric acid and the origin of organic compounds in atmospheric nanoparticle growth

    NASA Astrophysics Data System (ADS)

    Vakkari, Ville; Tiitta, Petri; Jaars, Kerneels; Croteau, Philip; Beukes, Johan Paul; Josipovic, Miroslav; Kerminen, Veli-Matti; Kulmala, Markku; Venter, Andrew D.; Zyl, Pieter G.; Worsnop, Douglas R.; Laakso, Lauri

    2015-12-01

    Aerosol particles formed in the atmosphere are important to the Earth's climate system due to their ability to affect cloud properties. At present, little is known about the atmospheric chemistry responsible for the growth of newly formed aerosol particles to climate-relevant sizes. Here combining detailed aerosol measurements with a theoretical framework we found that depending on the gaseous precursors and size of the newly formed particles, the growth was dominated by either sulfuric acid accompanied by ammonium or organic compounds originating in either biogenic emissions or savannah fires. The contribution of sulfuric acid was larger during the early phases of the growth, but in clean conditions organic compounds dominated the growth from 1.5 nm up to climatically relevant sizes. Furthermore, our analysis indicates that in polluted environments the contribution of sulfuric acid to the growth may have been underestimated by up to a factor of 10.

  4. Reduction of Sulfur Compounds in the Sediments of a Eutrophic Lake Basin †

    PubMed Central

    Smith, Richard L.; Klug, Michael J.

    1981-01-01

    Concentrations of various sulfur compounds (SO42−, H2S, S0, acid-volatile sulfide, and total sulfur) were determined in the profundal sediments and overlying water column of a shallow eutrophic lake. Low concentrations of sulfate relative to those of acid-volatile sulfide and total sulfur and a decrease in total sulfur with sediment depth implied that the contribution of dissimilatory sulfur reduction to H2S production was relatively minor. Addition of 1.0 mM Na235SO4 to upper sediments in laboratory experiments resulted in the production of H235S with no apparent lag. Kinetic experiments with 35S demonstrated an apparent Km of 0.068 mmol of SO42− reduced per liter of sediment per day, whereas tracer experiments with 35S indicated an average turnover time of the sediment sulfate pool of 1.5 h. Total sulfate reduction in a sediment depth profile to 15 cm was 15.3 mmol of sulfate reduced per m2 per day, which corresponds to a mineralization of 30% of the particulate organic matter entering the sediment. Reduction of 35S0 occurred at a slower rate. These results demonstrated that high rates of sulfate reduction occur in these sediments despite low concentrations of oxidized inorganic compounds and that this reduction can be important in the anaerobic mineralization of organic carbon. PMID:16345774

  5. Sulfur-containing amino acid methionine as the precursor of volatile organic sulfur compounds in algea-induced black bloom.

    PubMed

    Lu, Xin; Fan, Chengxin; He, Wei; Deng, Jiancai; Yin, Hongbin

    2013-01-01

    After the application of methionine, a progressive and significant increase occurred in five volatile organic sulfur compounds (VOSCs): methanethiol (MeSH), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS) and dimethyl tetrasulfide (DMTeS). Even in the untreated control without a methionine addition, methionine and its catabolites (VOSCs, mainly DMDS) were found in considerable amounts that were high enough to account for the water's offensive odor. However, blackening only occurred in two methionine-amended treatments. The VOSCs production was observed to precede black color development, and the reaching of a peak value for total VOSCs was often followed by water blackening. The presence of glucose stimulated the degradation of methionine while postponing the occurrence of the black color and inhibiting the production of VOSCs. In addition, DMDS was found to be the most abundant species produced after the addition of methionine alone, and DMTeS appeared to be the most important compound produced after the addition of methionine+glucose. These results suggest that methionine acted as an important precursor of the VOSCs in lakes suffering from algea-induced black bloom. The existence of glucose may change the transformation pathway of methionine into VOSCs to form larger molecular weight compounds, such as DMTS and DMTeS. PMID:23586297

  6. Sulfur compounds in therapy: Radiation-protective agents, amphetamines, and mucopolysaccharide sulfation

    SciTech Connect

    Foye, W.O. )

    1992-09-01

    Sulfur-containing compounds have been used in the search for whole-body radiation-protective compounds, in the design of amphetamine derivatives that retain appetite-suppressive effects but lack most behavioral effects characteristic of amphetamines, and in the search for the cause of kidney stone formation in recurrently stoneforming patients. Organic synthetic procedures were used to prepare radiation-protective compounds having a variety of sulfur-containing functional groups, and to prepare amphetamine derivatives having electron-attracting sulfur functions. In the case of the kidney stone causation research, isolation of urinary mucopolysaccharides (MPS) from recurrently stoneforming patients was carried out and the extent of sulfation of the MPS was determined by electrophoresis. Whole-body radiation-protective agents with a high degree of protection against lethal doses of gamma-radiation in mice were found in a series of quinolinium and pyridinium bis(methylthio) and methylthio amino derivatives. Mechanism studies showed that the copper complexes of these agents mimicked the beneficial action of superoxide dismutase. Electron-attracting sulfur-containing functions on amphetamine nitrogen, as well as 4'-amino nitrogen provided amphetamine derivatives with good appetite-suppressant effects and few or no adverse behavioral effects. Higher than normal levels of sulfation of the urinary MPS of stone formers suggested a cause for recurrent kidney stone formation. A sulfation inhibitor was found to prevent recurrence of stone formation and inhibit growth of existing stones. The inclusion of various sulfur-containing functions in organic molecules yielded compounds having whole-body radiation protection from lethal doses of gamma-radiation in animals. The presence of electron-attracting sulfur functions in amphetamine gave derivatives that retained appetite-suppressant effects and eliminated most adverse behavioral effects.

  7. Predicting liquid densities of organic compounds: II, Nitrogen and sulfur compounds

    SciTech Connect

    Wood, G.O.; Weaver, T.B.

    1993-02-01

    Correlations of liquid densities have been extended to more classes of organic compounds. The products of liquid density and molecular weight at or near 20{degrees}C were previously found to be linear functions of the number and types of carbon atoms in the molecule. Cyclic carbon atoms contributed more to density than carbon atoms not part of a ring structure. Carbon atoms which occupy two rings have since been found to contribute even different increments. Additional databases of liquid densities have been set up for compounds with cyclic oxygen atoms, cyclic and noncyclic nitrogen atoms, and cyclic and noncyclic sulfur atoms. Correlation parameters have been obtained by fitting these data by least squares minimization.

  8. Gas chromatography combined with mass spectrometry for the identification of organic sulfur compounds in shellfish and fish

    SciTech Connect

    Ogata, M.; Miyake, Y.

    1980-11-01

    The authors determined that the organic sulfur compounds usually contained in crude oil can be used as a marker of oil pollution in shellfish and fish. Short-necked clams and eels were maintained in a controlled laboratory environment in water with suspension of crude oil. Mass spectra and mass chromatograms of short-necked clam extract showed the presence of organic sulfur compounds. Capillary column gas chromatography-mass chromatograms of crude oil and extract from the soft body of a short-necked clam showed the presence of organic sulfur compounds. Besides sulfur components, various other compounds were contained in crude oil and short-necked clam. Mass chromatograms of crude oil and the extract from eel flesh showed the presence of alkyl benzothiophene, dibenzothiophene, naphthalene, and alkyl naphthalene. Data indicated that the organic sulfur compounds and polyaromatic compounds could serve as markers of oil pollution in shellfish and fish.

  9. INFLUENCE OF DIETARY METHIONINE SOURCE ON VOLATILE SULFUR COMPOUNDS IN BROILER EXCRETA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To evaluate the impact of methionine source on volatile sulfur compounds in broiler excreta a trial was conducted using straight run broiler chicks raised in battery cages. Chicks were randomly distributed into 3 replications of 5 treatment groups with 16 birds per pen. The treatment groups were d...

  10. Volatile Organic Sulfur Compounds of Environmental Interest: Dimethyl Sulfide and Methanethiol

    ERIC Educational Resources Information Center

    Chasteen, Thomas G.; Bentley, Ronald

    2004-01-01

    Volatile organic sulfur compounds (VOSCs) have been assigned environmental roles in global warming, acid precipitation, and cloud formation where two important members dimethyl sulfide (CH3)2 S, DMS, and methanethiol, CH3SH, MT, of VOSC group are involved.

  11. Phosphorothiolation of Aryl Boronic Acids Using P(O)H Compounds and Elemental Sulfur.

    PubMed

    Xu, Jian; Zhang, Liangliang; Li, Xueqin; Gao, Yuzhen; Tang, Guo; Zhao, Yufen

    2016-03-18

    The first multicomponent reaction (MCR) involving aryl boronic acids, elemental sulfur, and P(O)H compounds is presented. It proceeds with excellent yields and provides an attractive approach for the construction of valuable S-aryl phosphorothioates and S-aryl phosphorodithioates using a one-step strategy. Moreover, this method can be easily adapted to large-scale preparation. PMID:26934082

  12. Field sampling method for quantifying volatile sulfur compounds from animal feeding operations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Volatile sulfur compounds (VSCs) are a major class of chemicals associated with odor from animal feeding operations (AFO). Identifying and quantifying VSCs in air is challenging due to their volatility, reactivity, and low concentrations in ambient air. In the present study, a canister based metho...

  13. Sulfur 1s near-edge x-ray absorption fine structure (NEXAFS) of thiol and thioether compounds

    SciTech Connect

    Beyhan, Shirin; Urquhart, Stephen G.; Hu Yongfeng

    2011-06-28

    The speciation and quantification of sulfur species based on sulfur K-edge x-ray absorption spectroscopy is of wide interest, particularly for biological and petroleum science. These tasks require a firm understanding of the sulfur 1s near-edge x-ray absorption fine structure (NEXAFS) spectra of relevant species. To this end, we have examined the gas phase sulfur 1s NEXAFS spectra of a group of simple thiol and thioether compounds. These high-resolution gas phase spectra are free of solid-state broadening, charging, and saturation effects common in the NEXAFS spectra of solids. These experimental data have been further analyzed with the aid of improved virtual orbital Hartree-Fock ab initio calculations. The experimental sulfur 1s NEXAFS spectra show fine features predicted by calculation, and the combination of experiment and calculation has been used to improve assignment of spectroscopic features relevant for the speciation and quantification of the sulfur compounds.

  14. RNA transcript sequencing reveals inorganic sulfur compound oxidation pathways in the acidophile Acidithiobacillus ferrivorans.

    PubMed

    Christel, Stephan; Fridlund, Jimmy; Buetti-Dinh, Antoine; Buck, Moritz; Watkin, Elizabeth L; Dopson, Mark

    2016-04-01

    Acidithiobacillus ferrivoransis an acidophile implicated in low-temperature biomining for the recovery of metals from sulfide minerals.Acidithiobacillus ferrivoransobtains its energy from the oxidation of inorganic sulfur compounds, and genes encoding several alternative pathways have been identified. Next-generation sequencing ofAt. ferrivoransRNA transcripts identified the genes coding for metabolic and electron transport proteins for energy conservation from tetrathionate as electron donor. RNA transcripts suggested that tetrathionate was hydrolyzed by thetetH1gene product to form thiosulfate, elemental sulfur and sulfate. Despite two of the genes being truncated, RNA transcripts for the SoxXYZAB complex had higher levels than for thiosulfate quinone oxidoreductase (doxDAgenes). However, a lack of heme-binding sites insoxXsuggested that DoxDA was responsible for thiosulfate metabolism. Higher RNA transcript counts also suggested that elemental sulfur was metabolized by heterodisulfide reductase (hdrgenes) rather than sulfur oxygenase reductase (sor). The sulfite produced as a product of heterodisulfide reductase was suggested to be oxidized by a pathway involving thesatgene product or abiotically react with elemental sulfur to form thiosulfate. Finally, several electron transport complexes were involved in energy conservation. This study has elucidated the previously unknownAt. ferrivoranstetrathionate metabolic pathway that is important in biomining. PMID:26956550

  15. A modeling study of the long-range transport of sulfur compounds over the eastern Asia

    SciTech Connect

    Lin, N.H.; Chen, J.H.

    1996-12-31

    In this paper a quantitative method is developed to classify the potential impact of sulfur emissions from the eastern Asia on Taiwan areas, based on a coupled Lagrangian air-parcel and simplified linear sulfur-chemistry model. The investigated region covers the eastern Asia areas located between 10{degrees}N-45{degrees}N in latitude and 100{degrees}E-135{degrees}E in longitude with the 1{degrees}x1{degrees} grid size applied in above model. The 1991-1992 EC/TOGA meteorological data were used to drive the air-parcel model. The sulfur emissions from grids were based on the inventories of Akimoto and Narita. The potential impact (which is expressed as an index) from individual model grids on Taiwan areas was defined as a function of sulfur emission strength and traveling distance along the trajectory of an air parcel. As a result, the locations of high pollution potential to Taiwan areas were found to be dependent upon the seasons. For instance, the northern and northeastern China and the southern Korea areas had the highest potential impact on Taiwan areas during the northeastern monsoons. For further application of above model, the transport, transformation, and dry deposition of sulfur compounds over the model domain in a case during the northeastern monsoons, were investigated. The results indicated that Taiwan was one of the potential source areas of sulfate deposition on the South China Sea, while received the sulfate deposition primarily from the northern China.

  16. Sulfurized metal borohydrides.

    PubMed

    Paskevicius, M; Richter, B; Polański, M; Thompson, S P; Jensen, T R

    2016-01-14

    The reactions between metal borohydrides and elemental sulfur are investigated in situ during thermal treatment and are found to be highly exothermic (up to 700 J g(-1)). These reactions are exceptionally rapid, occurring below 200 °C, also resulting in the sudden release of substantial quantities of hydrogen gas. For NaBH4 this hydrogen release is pure, with no detectable levels of H2S or B2H6. The reaction results in the formation of an array of metal-boron-sulfur compounds. These MBH4-S compounds are interesting for possible uses in high energy applications (fuels or explosives), hydrogen generation, and metal-boron-sulfur precursors. PMID:26615897

  17. Microbial removal of organic sulfur from coal (bacterial degradation of sulfur-containing heterocyclic compounds): Final report, March 1--December 31, 1987

    SciTech Connect

    Klubek, B.; Clark, D.

    1988-03-01

    The presence of levels of sulfur in coal is a major source of air pollution and considerable efforts are being made to devise a cost-effective way of removing it. One promising method is microbial desulfurization. Almost all of the inorganic sulfur can be removed from coal by the bacteria Thiobacillus or Sulfolobus, which convert sulfide to sulfate but leave the organic sulfur untouched. If strains of bacteria are developed which remove organic sulfur from coal and are used in conjunction with inorganic sulfur-oxidizing bacteria, the result should be an effective desulfurization method. We are using two approaches to develop bacteria which remove organic sulfur. One method is to mutate a laboratory species, Escherichia coli, an organism which is genetically well understood and whose pathways for the metabolism of sulfur-containing amino acids have been extensively investigated. Such thiophene degraders can be genetically analyzed, and the genes involved can be cloned in order to amplify their products. The second approach is the development of naturally occurring bacteria capable of thiophene degradation. Enrichment culture techniques, mutagenesis of current isolated strains, and mixed culture studies with crushed coal comprise an alternative approach in our study. The degradation rates of our model-thiophene compounds and the preliminary testing of our isolates with coal will index the efficiency of our strains in coal desulfurization. Ultimately, the genes responsible for thiophene degradation by our isolated strains will be transferred to our E. coli strain, creating a single organism capable of degrading a broad spectrum of thiophene compounds. 14 refs., 5 tabs.

  18. Biological technologies for the removal of sulfur containing compounds from waste streams: bioreactors and microbial characteristics.

    PubMed

    Li, Lin; Zhang, Jingying; Lin, Jian; Liu, Junxin

    2015-10-01

    Waste gases containing sulfur compounds, such as hydrogen sulfide, sulfur dioxide, thioethers, and mercaptan, produced and emitted from industrial processes, wastewater treatment, and landfill waste may cause undesirable issues in adjacent areas and contribute to atmospheric pollution. Their control has been an area of concern and research for many years. As alternative to conventional physicochemical air pollution control technologies, biological treatment processes which can transform sulfur compounds to harmless products by microbial activity, have gained in popularity due to their efficiency, cost-effectiveness and environmental acceptability. This paper provides an overview of the current biological techniques used for the treatment of air streams contaminated with sulfur compounds as well as the advances made in the past year. The discussion focuses on bioreactor configuration and design, mechanism of operation, insights into the overall biological treatment process, and the characterization of the microbial species present in bioreactors, their populations and their interactions with the environment. Some bioreactor case studies are also introduced. Finally, the perspectives on future research and development needs in this research area were also highlighted. PMID:26250546

  19. Low temperature removal of inorganic sulfur compounds from mining process waters.

    PubMed

    Liljeqvist, Maria; Sundkvist, Jan-Eric; Saleh, Amang; Dopson, Mark

    2011-06-01

    Process water and effluents from mining operations treating sulfide rich ores often contain considerable concentrations of metastable inorganic sulfur compounds such as thiosulfate and tetrathionate. These species may cause environmental problems if released to downstream recipients due to oxidation to sulfuric acid catalyzed by acidophilic microorganisms. Molecular phylogenic analysis of the tailings pond and recipient streams identified psychrotolerant and mesophilic inorganic sulfur compound oxidizing microorganisms. This suggested year round thiosalt oxidation occurs. Mining process waters may also contain inhibiting substances such as thiocyanate from cyanidation plants. However, toxicity experiments suggested their expected concentrations would not inhibit thiosalt oxidation by Acidithiobacillus ferrivorans SS3. A mixed culture from a permanently cold (4-6 °C) low pH environment was tested for thiosalt removal in a reactor design including a biogenerator and a main reactor containing a biofilm carrier. The biogenerator and main reactors were successively reduced in temperature to 5-6 °C when 43.8% of the chemical oxidation demand was removed. However, it was found that the oxidation of thiosulfate was not fully completed to sulfate since low residual concentrations of tetrathionate and trithionate were found in the discharge. This study has demonstrated the potential of using biotechnological solutions to remove inorganic sulfur compounds at 6°C and thus, reduce the impact of mining on the environment. PMID:21280027

  20. Chalcogen bonding interactions between reducible sulfur and selenium compounds and models of zinc finger proteins.

    PubMed

    Lutz, Patricia B; Bayse, Craig A

    2016-04-01

    Reducible sulfur and selenium (r-S/Se) compounds, defined as sulfur and selenium compounds not in the lowest -2 oxidation state (e.g., -1 to +6), release Zn(2+) from zinc-sulfur proteins such as zinc fingers (ZFs) and metallothionein. A series of density functional theory calculations was performed on donor-acceptor complexes between r-S/Se compounds and models of the Cys2His2, Cys3His and Cys4 ZF sites. These S⋯S/Se chalcogen bonding interactions consist of the donation of electron density from a S lone pair on the ZF model to a S/Se-X antibonding molecular orbital of the r-S/Se compound. The strength of the interaction was shown to be dependent upon the Lewis basicity of the ZF model (Cys4>Cys3His>Cys2His2) and the Lewis acidity of the r-S/Se compound as measured by the energy of the S/Se-X antibonding orbital. Interactions with the softer r-Se compounds were stronger than the r-S compounds, consistent with the greater reactivity of the former with ZF proteins. PMID:26877152

  1. Sulfuric Acid in the Venus Clouds

    NASA Technical Reports Server (NTRS)

    Sill, G. T.

    1972-01-01

    The visible and ultraviolet transmission features of a thin layer of elemental bromine and hydrobromic acid dissolved in sulfuric acid somewhat resemble the Venus spectrum, up to 14 microns. The chemical process postulated for forming sulfuric acid involves the oxidation of sulfur and its compounds to sulfuric acid through the agency of elemental bromine, produced by the photolytic decomposition of hydrogen bromide.

  2. Sulfur and Hydrogen Isotope Anomalies in Organic Compounds from the Murchison Meteorite

    NASA Technical Reports Server (NTRS)

    Cooper, G. W.; Thiemens, M. H.; Jackson, T.; Chang, Sherwood

    1996-01-01

    Isotopic measurements have been made on organic sulfur and phosphorus compounds recently discovered in the Murchison meteorite. Carbon, hydrogen and sulfur measurements were performed on individual members of the organic sulfur compounds, alkyl sulfonates; and carbon and hydrogen measurements were made on bulk alkyl phosphonates. Cooper and Chang reported the first carbon isotopic measurements of Murchison organic sulfonates, providing insight into the potential synthetic mechanisms of these and, possibly, other organic species. Hydrogen isotopic measurements of the sulforiates now reveal deuterium excesses ranging from +660 to +2730 %. The deuterium enrichments indicate formation of the hydrocarbon portion of these compounds in a low temperature astrophysical environment consistent with that of dense molecular clouds. Measurements of the sulfur isotopes provide further constraints on the origin and mechanism of formation of these organic molecules. Recently, there has been growing documentation of sulfur isotopic anomalies in meteoritic material. Thiemens and Jackson have shown that some bulk ureilites possess excess S-33 and Thiemens et al. have reported excess S-33 in an oldhamite separate from the Norton County meteorite. Rees and Thode reported a large S-33 excess in an Allende acid residue, however, attempts to verify this measurements have been unsuccessful, possibly due to the heterogeneous nature of the carrier phase. With the recognition that sulfur isotopes may reflect chemistry in the protosolar nebula or the precursor molecular cloud, identification of potential carriers is of considerable interest. In the present study, the stable isotopes of sulfur were measured in methane sulfonic acid extracted from the Murchison meteorite. The isotopic composition was found to be: (delta)S-33 = 2.48 %, (delta)S-34 = 2.49 % and (delta)S-36 = 6.76 %. Based upon analysis of more than 60 meteoritic and numerous terrestrial samples, the mass fractionation lines are defined by Delta-33 = (delta)S-33 -0.50(delta)S-34 and Delta-36 = (delta)s-36 - 1.97 (delta)S-34. From these relationships Delta-33 = 1.24 % and Delta-36 = 0.89 % are observed. These anomalies, particularly the Delta-33, lie well outside the range of analytical uncertainty. They are the largest observed in any meteoritic component and the first found in an organosulfur compound. As discussed by Thiemens and Jackson, due to it's position on the periodic chart, sulfur undergoes chemically induced mass independent isotopic fractionations as does oxygen. Experiments by Mauersberger et. al. show that in such processes, the magnitude of fractionation for the different isotopically substituted species varies with mass and angular momentum; thus, anomalies are expected for both S-33 and S-36, but not necessarily of the same magnitude. Laboratory experiments have also confirmed that chemically produced, mass independent fractionations are mediated by molecular symmetry factors. A chemical source of fractionation requires that the sulfur isotopic anomaly was established in the gas phase, probably in reactions involving symmetric CS2. The discovery of an anomalous sulfur isotopic composition in a specific molecule containing excess deuterium is an important advance in the understanding of the cosmochemistry of sulfur. This evidence suggests that methanesulfonic acid was synthesized by interstellar processes. Further measurements and details of possible synthesis and fractionation mechanisms will be presented.

  3. Solubility of Sulfur Dioxide in Sulfuric Acid

    NASA Technical Reports Server (NTRS)

    Chang, K. K.; Compton, L. E.; Lawson, D. D.

    1982-01-01

    The solubility of sulfur dioxide in 50% (wt./wt.) sulfuric acid was evaluated by regular solution theory, and the results verified by experimental measurements in the temperature range of 25 C to 70 C at pressures of 60 to 200 PSIA. The percent (wt./wt.) of sulfur dioxide in 50% (wt./wt.) sulfuric acid is given by the equation %SO2 = 2.2350 + 0.0903P - 0.00026P 10 to the 2nd power with P in PSIA.

  4. SYNTHESIS AND BIOLOGICAL ACTIVITY OF SULFUR COMPOUNDS SHOWING STRUCTURAL ANALOGY WITH COMBRETASTATIN A-4

    PubMed Central

    dos Santos, Edson dos A.; Prado, Paulo C.; de Carvalho, Wanderley R.; de Lima, Ricardo V.; Beatriz e, Adilson; de Lima, Dênis P.; Hamel, Ernest; Dyba, Marzena A.; Albuquerque, Sergio

    2013-01-01

    We extended our previous exploration of sulfur bridges as bioisosteric replacements for atoms forming the bridge between the aromatic rings of combretastatin A-4. Employing coupling reactions between 5-iodo-1,2,3-trimethoxybenzene and substituted thiols, followed by oxidation to sulfones with m-CPBA, different locations for attaching the sulfur atom to ring A through the synthesis of nine compounds were examined. Antitubulin activity was performed with electrophoretically homogenous bovine brain tubulin, and activity occurred with the 1,2,3-trimethoxy-4-[(4-methoxyphenyl)thio]benzene (12), while the other compounds were inactive. The compounds were also tested for leishmanicidal activity using promastigote forms of Leishmania braziliensis (MHOM/BR175/M2904), and the greatest activity was observed with 1,2,3-trimethoxy-4-(phenylthio)benzene (10) and 1,2,3-trimethoxy-4-[(4-methoxyphenyl) sulfinyl]benzene (15). PMID:23766547

  5. ATMOSPHERIC CHEMISTRY OF SELECTED SULFUR-CONTAINING COMPOUNDS. OUTDOOR SMOG CHAMBER STUDY. PHASE 2

    EPA Science Inventory

    The photochemical behavior of mixtures of selected sulfur containing species, hydrocarbons, and nitrogen oxides was examined in outdoor smog chambers. Sulfur dioxide, H2S, CH3SH, COS, and thiophene are the sulfur species tested. A surrogate ambient hydrocarbon mixture comprised o...

  6. Thermothrix thiopara: Growth and Metabolism of a Newly Isolated Thermophile Capable of Oxidizing Sulfur and Sulfur Compounds

    PubMed Central

    Brannan, Daniel K.; Caldwell, Douglas E.

    1980-01-01

    Thermothrix thiopara is isolated from hot sulfur springs. It occurs in situ at a temperature of 72C, a pH of 7.0, and an HS- concentration of 17.4 ?mol/liter (0.8 ppm). The organism was capable of autotrophic growth. Sulfite, sulfur, and polythionates were formed and subsequently degraded to sulfate during growth with thiosulfate as the sole energy source. Thiosulfate was oxidized by the polythionate pathway, and the stoichiometry of growth on thiosulfate was determined. The organism was also capable of heterotrophic growth in amino acids and simple sugars. A source of reduced sulfur (methionine, glutathione) was required for heterotrophic growth. Growth occurred aerobically or anaerobically with nitrate as a terminal oxidant. Both nitrous oxide and dinitrogen were produced. At 73C the maximum autotrophic growth rate in batch culture using thiosulfate was 0.56 generation per h. Under the same conditions in continuous culture, washout occurred at a dilution rate of 0.3 to 0.4 per h, corresponding to a cellular growth rate of 0.43 to 0.58 generation per h. This was nearly three times the growth rate for Thiobacillus denitrificans. T. thiopara is gram negative. It was also found to be both lysozyme and penicillin susceptible. As a result, this organism cannot be considered an archaebacterium. PMID:16345601

  7. Defluorination of organofluorine sulfur compounds by Pseudomonas sp. strain D2

    SciTech Connect

    Key, B.D.; Criddle, C.S.; Howell, R.D.

    1998-08-01

    Little is known of the potential for biodegradation of fluorinated sulfonates. Because of the apparent stability of fluorinated organics, their bioactivity, and their potential for accumulation in the environment, it is important to understand their environmental fate and the mechanisms by which they might be degraded. To evaluate this potential, the following model compounds were selected: difluoromethane sulfonate (DFMS), trifluoromethane sulfonate (TFMS), 2,2,2-trifluoroethane sulfonate (TES), perfluorooctane sulfonate (PFOS), and 1H,1H,2H,2H-perfluorooctane sulfonate (H-PFOS). A laboratory isolate designated Pseudomonas sp. strain D2 completely defluorinated DFMS under aerobic sulfur-limiting conditions in a defined mineral medium. Strain D2 utilized DFMS as the sole source of sulfur, but not as a source of carbon or energy. DFMS utilization was inhibited by other forms of sulfur, and noncompetitive inhibition kinetics were observed, with K{sub i}-values of 3--4 {micro}M for sulfate, sulfite, methane sulfonate, and cystine. Strain D2 was subsequently used to evaluate degradation of other fluorinated sulfonates. Growth and defluorination were only observed for those compounds containing hydrogen (TES and H-PFOS). TFMS and PFOS were not degraded. TES was completely defluorinated, and H-PFOS was partially defluorinated. No volatile transformation products were detected for TES or DFMS, but six volatile products were detected for H-PFOS. All of the volatile products contained oxygen and fluorine, but not sulfur. This is the first report of defluorination of fluorinated sulfonates, a linkage between sulfur assimilation and defluorination, and generation of volatile fluorinated biotransformation products.

  8. Thermodynamics of Aqueous Organic Sulfur Compounds: A Key to the Organic Geochemistry of Hydrothermal Systems?

    NASA Technical Reports Server (NTRS)

    Schulte, Mitchell; Rogers, Karyn L.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Hydrothermal environments are locations of varied geochemistry due to the disequilibrium between vent fluids and seawater. The disequilibrium geochemistry has been hypothesized to include reactions to synthesize organic compounds. Observations of the organic geochemistry of hydrothermal vent sites has received little attention. Experimental simulations of these environments, however, indicate that organic compounds may have difficulty forming in a purely aqueous environment. On the other hand, thiols. thioesters and disulfides have been implicated as reaction intermediates between CO or CO2 in experiments of carbon reduction in hydrothermal environments as well as in a variety of biological processes and other abiotic reactions (Wachtershauser, 1990, OLEB 20, 173; Heinen and Lauwers, 1996, OLEB 26, 13 1, Huber and Wachtershauser, 1997, Science 276, 245; Russell et al., 1998, in Thermophiles: The keys to molecular evolution and the origin of life?). The reduction of CO2 to thiols, for example, is observed using the FeS-H2S/FeS2 couple to provide the reducing power (see Schoonen et al., 1999, OLEB 29, 5). In addition, the enzyme involved in final stage of methanogenesis, coenzyme-M, is itself a thiol. Thus, organic sulfur compounds may hold the key to the organic chemistry leading to the origin of life at high temperatures. Understanding the biochemical processes of microorganisms that can live to temperatures at least as high as 113 C (Blochl et al., 1996, Extremophiles 1, 14) requires knowledge of the properties of the chemical reactions involved. In order to assess the role of aqueous organic sulfur compounds in hydrothermal organic geochemistry, we have been attempting to determine their thermodynamic properties. We have culled the literature to obtain the properties of organic sulfur compounds. We are able to calculate a number of essential properties, such as free energies of formation, from solubility data available in the literature together with standard properties of organic sulfur gases. However, a number of the properties for aqueous organic sulfur compounds have not been experimentally determined. Furthermore, most of thermodynamic data that are available are for 25 C and 1 bar. In order to determine reaction properties to temperatures and pressures appropriate to the hydrothermal conditions in which thermophilic organisms actually live, we use equations of state developed by Helgeson and co-workers (Helgeson et al., 1981, AJS 281, 1249). A key piece of information needed to go up in temperature is the partial molal heat capacity, which is one of the properties for which experimental data are unavailable for nearly all organic sulfur compounds. We have used correlation methods to determine the partial molal heat capacities and volumes of many organic solutes. These estimates allow us to asses the role of organic sulfur compounds during the reduction of carbon in hydrothermal settings. We will present these data, along with examples of the thermodynamic properties of reactions involving aqueous organic sulfur compounds.

  9. Enhanced Elemental Mercury Removal from Coal-fired Flue Gas by Sulfur-chlorine Compounds

    SciTech Connect

    Chang, Shih-Ger; Yan, Nai-Qiang; Qu, Zan; Chi, Yao; Qiao, Shao-Hua; Dod, Ray; Chang, Shih-Ger; Miller, Charles

    2008-07-02

    Oxidation of Hg0 with any oxidant or converting it to a particle-bound form can facilitate its removal. Two sulfur-chlorine compounds, sulfur dichloride (SCl2) and sulfur monochloride (S2Cl2), were investigated as oxidants for Hg0 by gas phase reaction and by surface-involved reactions in the presence of flyash or activated carbon. The gas phase reaction rate constants between Hg0 and the sulfur/chlorine compounds were determined, and the effects of temperature and the main components in flue gases were studied. The gas phase reaction between Hg0 and SCl2 is shown to be more rapid than the gas phase reaction with chlorine, and the second order rate constant was 9.1(+-0.5) x 10-18 mL-molecules-1cdots-1 at 373oK. Nitric oxide (NO) inhibited the gas phase reaction of Hg0 with sulfur-chlorine compounds. The presence of flyash or powdered activated carbon in flue gas can substantially accelerate the reaction. The predicted Hg0 removal is about 90percent with 5 ppm SCl2 or S2Cl2 and 40 g/m3 of flyash in flue gas. The combination of activated carbon and sulfur-chlorine compounds is an effective alternative. We estimate that co-injection of 3-5 ppm of SCl2 (or S2Cl2) with 2-3 Lb/MMacf of untreated Darco-KB is comparable in efficiency to the injection of 2-3 Lb/MMacf Darco-Hg-LH. Extrapolation of kinetic results also indicates that 90percent of Hg0 can be removed if 3 Lb/MMacf of Darco-KB pretreated with 3percent of SCl2 or S2Cl2 is used. Unlike gas phase reactions, NO exhibited little effect on Hg0 reactions with SCl2 or S2Cl2 on flyash or activated carbon. Mercuric sulfide was identified as one of the principal products of the Hg0/SCl2 or Hg0/S2Cl2 reactions. Additionally, about 8percent of SCl2 or S2Cl2 in aqueous solutions is converted to sulfide ions, which would precipitate mercuric ion from FGD solution.

  10. Sulfur and Hydrogen Isotope Anomalies in Organic Compounds from the Murchison Meteorite

    NASA Astrophysics Data System (ADS)

    Cooper, G. W.; Thiemens, M. H.; Jackson, T.; Chang, S.

    1995-09-01

    Carbon, hydrogen and sulfur isotopic measurements have been made on individual members of a recently discovered class of organic sulfur compounds, alkyl sulfonates, in the Murchison meteorite. Cooper and Chang (1) reported the first carbon isotopic measurements of Murchison organic sulfonates, providing insight into potential synthetic mechanisms of these, and possibly other, organic species. Hydrogen isotopic measurements of the sulfonates now reveal deuterium excesses ranging from +660 to +2730 per mil. The deuterium enrichments indicate formation of the hydrocarbon portion of these compounds in a low temperature astrophysical environment consistent with that of dense molecular clouds. Measurement of the sulfur isotopes provide further constraints on the origin and mechanism of formation of these organic molecules. Recently, there has been growing documentation of sulfur isotopic anomalies in meteoritic material. Thiemens and Jackson (2) have shown that some bulk ureilites possess excess 33S and Thiemens et al. (3) have reported excess 33S in an oldhamite separate from Norton County. Rees and Thode (4) reported a large 33S excess in an Allende acid residue, however, attempts to verify this measurement have been unsuccessful, possibly due to the heterogeneous nature of the carrier phase. With the recognition that sulfur isotopes may reflect nebular chemistry, identification of potential carriers is of considerable interest. In the present study the three stable isotopes of sulfur were measured in methane sulfonate extracted from the Murchison meteorite. The isotopic composition was found to be delta 33S=2.48, delta 34S=2.49 and delta 36S = 6.76 per mil. Based upon analysis of more than 60 meteoritic, and numerous terrestrial samples, the mass fractionation lines are defined by 33Delta = delta 33S-0.50 delta 34S and 36Delta = delta 36S -1.97 delta 34S. From these relations a 33Delta = 1.24 per mil and 36Delta = 0.89 per mil is observed. These anomalies, particularly the 33Delta, are well outside the range of analytical uncertainty, especially for the 33Delta, and are the largest observed in any meteoritic component. As discussed by Thiemens and Jackson (2), due to its position on the periodic chart, sulfur chemically produces mass independent fractionations, as does oxygen. From experiments by Mauersberger et al. (5) it is observed that in a chemically produced mass independent fractionation process, the magnitude of fractionation for the different isotopically substituted species varies with mass and angular momentum, thus, anomalies are expected for both 33S and 36S, but not necessarily of the same magnitude. Laboratory experiments have also confirmed that chemically produced, mass independent fractionations occur , which are mediated by molecular symmetry factors (6). If the source of the fractionation is chemical, this requires that the sulfur isotopic anomaly was established in the gas phase, possibly from nebular reactions involving symmetric CS2. The discovery of an anomalous sulfur isotopic composition in a specific molecule containing excess deuterium is an important advance in the understanding of the cosmochemistry of sulfur. Further measurements and details of possible synthesis and fractionation mechanisms will be presented. References: [1] Cooper G. W. and S. Chang (1995) LPS XXVI, 281. [2] Thiemens M. H. and Jackson T. (1995) LPS XXVI, 1405. [3] Thiemens et al. (1994) Meteoritics, 29, 540. [4] Rees C. E. and Thode H. G. (1977) GCA, 57, 3171. [5] Mauersberger et al. (1993) GRL, 20, 1031. [6] Bains-Sahota S. K. and Thiemens M. H. (1989) J. Chem. Phys., 90, 6099.

  11. Prevention of Cardiovascular Diseases by Garlic-Derived Sulfur Compounds.

    PubMed

    Seki, Taiichiro; Hosono, Takashi

    2015-01-01

    Lifestyle-related diseases have complex pathogenesis which consists of several different steps. Basic causes of the diseases are attributed to unhealthy lifestyles in dietary habits, physical activity and suffering stress. The unhealthy lifestyles induce risk factors such as hypertension, dyslipidemia, obesity, and hyperglycemia. These risk factors all promote arteriosclerosis leading to serious vascular complications (i.e., thrombotic diseases), myocardial infarction and cerebral infarction. The total number of deaths from these thrombotic diseases almost equals that from cancer in our country. Cancer is also a typical lifestyle-related disease. Food has three different functions: the primary function is to provide enough nutrients to meet the metabolic requirements. The secondary function is the one relating to food preference. The third function is to control our body functions, which help reduction of the risk of diseases. Some of the compounds derived from food, especially phytochemicals in edible plants, vegetables and herbs, have potent functions to control our body functions and contribute to promoting our health. In this review article, we overview the lifestyle-related diseases and food functions involving prevention and amelioration of the diseases by food components especially from edible plants and vegetables. As an example, we will describe the food function of garlic and the prevention of lifestyle-related diseases by its components. Allyl sulfides are characteristic flavor compounds derived from garlic, and these organosulfur compounds are responsible for the food function of garlic. PMID:26598900

  12. PCDD/Fs' suppression by sulfur-amine/ammonium compounds.

    PubMed

    Fu, Jian-Ying; Li, Xiao-Dong; Chen, Tong; Lin, Xiao-Qing; Buekens, Alfons; Lu, Sheng-Yong; Yan, Jian-Hua; Cen, Ke-Fa

    2015-03-01

    Three distinct -S and -NH2 or NH4(+) containing compounds, including ammonium thiosulfate, aminosulfonic acid and thiourea, were studied as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) inhibitors. All these three -S and -N containing compounds tested show strong suppression of PCDD/Fs formation, especially for thiourea which has not been studied before. With a (S+N)/Cl molar ratio of only 0.47, thiourea could inhibit 97.3% of PCDD/Fs and even 99.8% of I-TEQ. At an unusually high de novo test temperature (650 °C), the PCDD/Fs' formation was still very low but also the inhibition capacity of thiourea was weak, with an efficiency of 59% for PCDD/Fs when with a (S+N)/Cl molar ratio of 1.40. The results also revealed that the inhibition capability of the combined -S/-NH2 or -S/NH4(+) suppressant was strongly influenced by both the nature of the functional group of nitrogen and the value of the molar ratio (S+N)/Cl. The amine functional group -NH2 tends to be more efficient than ammonium NH4(+) and within a certain range a higher (S+N)/Cl value leads to a higher inhibition efficiency. Moreover, the emission of gases was continuously monitored: the Gasmet results revealed that SO2, HCN and NH3 were the most important decomposition products of thiourea. Thiourea is non-toxic, environment-friendly and can be sprayed into the post-combustion zone in form of powder or aqueous solution. The cost of thiourea at least can be partially compensated by its high inhibition efficiency. Therefore, the application of thiourea in a full-scale incinerator system is promising and encouraging. PMID:25481352

  13. Sulfuric acid on Europa and the radiolytic sulfur cycle

    NASA Technical Reports Server (NTRS)

    Carlson, R. W.; Johnson, R. E.; Anderson, M. S.

    1999-01-01

    A comparison of laboratory spectra with Galileo data indicates that hydrated sulfuric acid is present and is a major component of Europa's surface. In addition, this moon's visually dark surface material, which spatially correlates with the sulfuric acid concentration, is identified as radiolytically altered sulfur polymers. Radiolysis of the surface by magnetospheric plasma bombardment continuously cycles sulfur between three forms: sulfuric acid, sulfur dioxide, and sulfur polymers, with sulfuric acid being about 50 times as abundant as the other forms. Enhanced sulfuric acid concentrations are found in Europa's geologically young terrains, suggesting that low-temperature, liquid sulfuric acid may influence geological processes.

  14. Biochemistry of sulfur

    SciTech Connect

    Huxtable, R.J.; LaFranconi, W.M.

    1986-01-01

    This book presents information on the following topics: the chemistry of sulfur; the oxidation states of sulfur; the reduction of sulfate and the oxidation of sulfide; the sulfur cycle; oxidation of inorganic sulfide; the metabolism and functions of methionine; taurine and the oxidative metabolism of cysteine; thiols, disulfides, and thioesters; thioethers; thiamine; biotin; sulfates; inherited disorders of sulfur metabolism; cystinuria; sulfur and the metabolism of xenobiotics; general aspects of xenobiotic metabolism; glutathione and sulfation of xenobiotics; and metabolic activation as a result of sulfate conjugation.

  15. [Effects of sulfur compounds on Pb partitioning in a simulated MSW incinerator].

    PubMed

    Chen, Yong; Zhang, Yan-Guo; Li, Qing-Hai; Zhuo, Yu-Qun; Chen, Chang-He

    2008-03-01

    The effect of sulfur compounds (including sulfur, sulfide, sulfite and sulfate), initial concentration of heavy metal and operating conditions on Pb emission in MSW incineration were investigated using a simulated tubular furnace with the simulated MSW. Operating conditions of the experiment included combustion chamber temperature and MSW residence time. The concentration of Pb was measured by ICP-AES after the digesting of samples including bottom ash, fly ash and flue gas according to related USEPA methods. The results indicated that all 4 sulfur compounds tended to increase Pb partitioning in fly ash and decrease Pb partitioning in bottom ash. The increasing of S and Na2S content tended to decrease Pb partitioning in bottom ash, meanwhile, the content of Na2SO3 and Na2SO4 have no significant effects on Pb partitioning. Incineration temperature showed a significant effect on Pb volatilization, and thus the Pb partitioning in fly ash increasing along with temperature went upwards. Pb did not partition in flue gas during the whole experimental temperature range. Furthermore, the effect of initial concentration of heavy metal had a significant influence on Pb partitioning. The more initial concentration of Pb was, the more Pb partitioned in bottom ash. MSW residence time was also investigated. The longer MSW residence time was, the less Pb partitioned in bottom ash. PMID:18649551

  16. Adsorption of sulfur compound utilizing rice husk ash modified with niobium

    NASA Astrophysics Data System (ADS)

    Cavalcanti, Rodrigo M.; Pessoa Júnior, Wanison A. G.; Braga, Valdeilson S.; Barros, Ivoneide de C. L.

    2015-11-01

    Adsorbents based in rice husk ash (RHA) modified with niobium pentoxide were prepared for impregnation methods and applied in sulfur removal in liquid fuels. The solids were characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy, nitrogen physisorption and thermal analysis; they show that there was no qualitative change in the amorphous structure of the RHA; however, the method of impregnation could modify the particle size and topology of RHA particles. The larger sulfur removal (>50%) was achieved using RHA with 5 wt.% Nb2O5 at a dosage of 10 g L-1, after 4 h of contact with the model fuel. The kinetic study of adsorption of thiophene showed that the models of pseudo-second order and intra-particle diffusion best fit the experimental data. The adsorption experiments with the thiophenic derivatives compounds show a large selectivity of the adsorbent.

  17. Complete genome sequence of the sulfur compounds oxidizing chemolithoautotroph Sulfuricurvum kujiense type strain (YK-1T)

    SciTech Connect

    Han, Cliff; Kotsyurbenko, Oleg; Chertkov, Olga; Held, Brittany; Lapidus, Alla L.; Nolan, Matt; Lucas, Susan; Hammon, Nancy; Deshpande, Shweta; Cheng, Jan-Fang; Tapia, Roxanne; Goodwin, Lynne A.; Pitluck, Sam; Liolios, Konstantinos; Pagani, Ioanna; Ivanova, N; Mavromatis, K; Mikhailova, Natalia; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Land, Miriam L; Hauser, Loren John; Chang, Yun-Juan; Jeffries, Cynthia; Brambilla, Evelyne-Marie; Rohde, Manfred; Spring, Stefan; Sikorski, Johannes; Goker, Markus; Woyke, Tanja; Bristow, James; Eisen, Jonathan; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C; Klenk, Hans-Peter; Detter, J. Chris

    2012-01-01

    Sulfuricurvum kujiense Kodama and Watanabe 2004 is the type species of the monotypic genus Sulfuricurvum, which belongs to the family Helicobacteriaceae in the class Epsilonproteobacteria. The species is of interest because it is frequently found in crude oil and oil sands where it utilizes various reduced sulfur compounds such as elemental sulfur, sulfide and thiosulfate as electron donors. Members of the species do not utilize sugars, organic acids and hydrocarbons as carbon and energy sources. This is the first completed genome sequence of a member of the genus Sulfuricurvum. The genome, which consists of a circular chromosome of 2,574,824 bp length and four plasmids of 118,585 bp, 71,513 bp, 51,014 bp, and 3,421 bp length, respectively, harboring a total of 2,879 protein-coding and 61 RNA genes and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  18. Sulfonates: A novel class of organic sulfur compounds in marine sediments

    NASA Astrophysics Data System (ADS)

    Vairavamurthy, Appathurai; Zhou, Weiqing; Eglinton, Timothy; Manowitz, Bernard

    1994-11-01

    X-ray absorption near-edge structure spectroscopy (XANES) used to measure sulfur speciation in a variety of organic-rich marine sediments has established sulfonates as a novel and major component of sedimentary organic sulfur. The origins of sulfonates in sediments are not clear, although both biological and geochemical mechanisms are possible. The accumulation of oxidized sulfonate sulfur in reducing marine sediments was not known previously; hence, a new perspective in sulfur geochemistry is established. The biogeochemical implications of the presence of sulfonates in marine sediments are discussed.

  19. Genetic Basis for Metabolism of Methylated Sulfur Compounds in Methanosarcina Species

    PubMed Central

    Fu, He

    2015-01-01

    ABSTRACT Methanosarcina acetivorans uses a variety of methylated sulfur compounds as carbon and energy sources. Previous studies implicated the mtsD, mtsF, and mtsH genes in catabolism of dimethylsulfide, but the genes required for use of other methylsulfides have yet to be established. Here, we show that a four-gene locus, designated mtpCAP-msrH, is specifically required for growth on methylmercaptopropionate (MMPA). The mtpC, mtpA, and mtpP genes encode a putative corrinoid protein, a coenzyme M (CoM) methyltransferase, and a major facilitator superfamily (MFS) transporter, respectively, while msrH encodes a putative transcriptional regulator. Mutants lacking mtpC or mtpA display a severe growth defect in MMPA medium but are unimpaired during growth on other substrates. The mtpCAP genes comprise a transcriptional unit that is highly and specifically upregulated during growth on MMPA, whereas msrH is monocistronic and constitutively expressed. Mutants lacking msrH fail to transcribe mtpCAP and grow poorly in MMPA medium, consistent with the assignment of its product as a transcriptional activator. The mtpCAP-msrH locus is conserved in numerous marine methanogens, including eight Methanosarcina species that we showed are capable of growth on MMPA. Mutants lacking the mtsD, mtsF, and mtsH genes display a 30% reduction in growth yield when grown on MMPA, suggesting that these genes play an auxiliary role in MMPA catabolism. A quadruple ΔmtpCAP ΔmtsD ΔmtsF ΔmtsH mutant strain was incapable of growth on MMPA. Reanalysis of mtsD, mtsF, and mtsH mutants suggests that the preferred substrate for MtsD is dimethylsulfide, while the preferred substrate for MtsF is methanethiol. IMPORTANCE Methylated sulfur compounds play pivotal roles in the global sulfur and carbon cycles and contribute to global temperature homeostasis. Although the degradation of these molecules by aerobic bacteria has been well studied, relatively little is known regarding their fate in anaerobic ecosystems. In this study, we identify the genetic basis for metabolism of methylmercaptopropionate, dimethylsulfide, and methanethiol by strictly anaerobic methanogens of the genus Methanosarcina. These data will aid the development of predictive sulfur cycle models and enable molecular ecological approaches for the study of methylated sulfur metabolism in anaerobic ecosystems. PMID:25691524

  20. Lunar Sulfur Capture System

    NASA Technical Reports Server (NTRS)

    Berggren, Mark; Zubrin, Robert; Bostwick-White, Emily

    2013-01-01

    The Lunar Sulfur Capture System (LSCS) protects in situ resource utilization (ISRU) hardware from corrosion, and reduces contaminant levels in water condensed for electrolysis. The LSCS uses a lunar soil sorbent to trap over 98 percent of sulfur gases and about two-thirds of halide gases evolved during hydrogen reduction of lunar soils. LSCS soil sorbent is based on lunar minerals containing iron and calcium compounds that trap sulfur and halide gas contaminants in a fixed-bed reactor held at temperatures between 250 and 400 C, allowing moisture produced during reduction to pass through in vapor phase. Small amounts of Earth-based polishing sorbents consisting of zinc oxide and sodium aluminate are used to reduce contaminant concentrations to one ppm or less. The preferred LSCS configuration employs lunar soil beneficiation to boost concentrations of reactive sorbent minerals. Lunar soils contain sulfur in concentrations of about 0.1 percent, and halogen compounds including chlorine and fluorine in concentrations of about 0.01 percent. These contaminants are released as gases such as H2S, COS, CS2,HCl, and HF during thermal ISRU processing with hydrogen or other reducing gases. Removal of contaminant gases is required during ISRU processing to prevent hardware corrosion, electrolyzer damage, and catalyst poisoning. The use of Earth-supplied, single-use consumables to entirely remove contaminants at the levels existing in lunar soils would make many ISRU processes unattractive due to the large mass of consumables relative to the mass of oxygen produced. The LSCS concept of using a primary sorbent prepared from lunar soil was identified as a method by which the majority of contaminants could be removed from process gas streams, thereby substantially reducing the required mass of Earth-supplied consumables. The LSCS takes advantage of minerals containing iron and calcium compounds that are present in lunar soil to trap sulfur and halide gases in a fixedbed reactor downstream of an in-ISRU process such as hydrogen reduction. The lunar-soil-sorbent trap is held at a temperature significantly lower than the operating temperature of the hydrogen reduction or other ISRU process in order to maximize capture of contaminants, but is held at a high enough temperature to allow moisture to pass through without condensing. The lunar soil benefits from physical beneficiation to remove ultrafine particles (to reduce pressure drop through a fixed bed reactor) and to upgrade concentrations of iron and/or calcium compounds (to improve reactivity with gaseous contaminants).

  1. The global sulfur cycle

    NASA Technical Reports Server (NTRS)

    Sagan, D. (Editor)

    1985-01-01

    The results of the planetary biology microbial ecology's 1984 Summer Research Program, which examined various aspects of the global sulfur cycle are summarized. Ways in which sulfur flows through the many living and chemical species that inhabit the surface of the Earth were investigated. Major topics studied include: (1) sulfur cycling and metabolism of phototropic and filamentous sulfur bacteria; (2) sulfur reduction in sediments of marine and evaporite environments; (3) recent cyanobacterial mats; (4) microanalysis of community metabolism in proximity to the photic zone in potential stromatolites; and (5) formation and activity of microbial biofilms on metal sulfides and other mineral surfaces. Relationships between the global sulfur cycle and the understanding of the early evolution of the Earth and biosphere and current processes that affect global habitability are stressed.

  2. Direct night-time ejection of particle-phase reduced biogenic sulfur compounds from the ocean to the atmosphere.

    PubMed

    Gaston, Cassandra J; Furutani, Hiroshi; Guazzotti, Sergio A; Coffee, Keith R; Jung, Jinyoung; Uematsu, Mitsuo; Prather, Kimberly A

    2015-04-21

    The influence of oceanic biological activity on sea spray aerosol composition, clouds, and climate remains poorly understood. The emission of organic material and gaseous dimethyl sulfide (DMS) from the ocean represents well-documented biogenic processes that influence particle chemistry in marine environments. However, the direct emission of particle-phase biogenic sulfur from the ocean remains largely unexplored. Here we present measurements of ocean-derived particles containing reduced sulfur, detected as elemental sulfur ions (e.g., (32)S(+), (64)S2(+)), in seven different marine environments using real-time, single particle mass spectrometry; these particles have not been detected outside of the marine environment. These reduced sulfur compounds were associated with primary marine particle types and wind speeds typically between 5 and 10 m/s suggesting that these particles themselves are a primary emission. In studies with measurements of seawater properties, chlorophyll-a and atmospheric DMS concentrations were typically elevated in these same locations suggesting a biogenic source for these sulfur-containing particles. Interestingly, these sulfur-containing particles only appeared at night, likely due to rapid photochemical destruction during the daytime, and comprised up to ∼67% of the aerosol number fraction, particularly in the supermicrometer size range. These sulfur-containing particles were detected along the California coast, across the Pacific Ocean, and in the southern Indian Ocean suggesting that these particles represent a globally significant biogenic contribution to the marine aerosol burden. PMID:25835033

  3. Sulfur compound production by Geotrichum candidum from L-methionine: importance of the transamination step.

    PubMed

    Bonnarme, P; Arfi, K; Dury, C; Helinck, S; Yvon, M; Spinnler, H E

    2001-12-18

    L-methionine degradation products and catabolic enzymatic activities involved in methanethiol generation were investigated in Geotrichum candidum GcG. L-methionine was easily degraded by G. candidum and the transamination product, 4-methylthio-2-oxobutyric acid (KMBA), was found to transiently accumulate. In parallel, considerable L-methionine aminotransferase activity was found in this microorganism. L-methionine and KMBA demethiolating activities were also detected. The degradation of KMBA corresponded to an overall increase in the production of volatile sulfur compounds. These results show that the transamination pathway is of major importance in the initial breakdown of L-methionine by this cheese-ripening microorganism. PMID:11750811

  4. Simulation of climate change induced by injection of sulfur compounds into the stratosphere

    NASA Astrophysics Data System (ADS)

    Volodin, E. M.; Kostrykin, S. V.; Ryaboshapko, A. G.

    2011-08-01

    An atmosphere-ocean general circulation model including the atmospheric chemistry and carbon cycle was used to perform numerical experiments to simulate the consequences of geoengineering. Out of the five emission scenarios considered here, the scenario where the injection of sulfur compounds occurs near the equator at an altitude between 22 and 24 km can be considered the most efficient in the sense of a maximum decrease in globally averaged surface temperature. We consider the equilibrium distribution of the sulfate aerosol and changes in temperature at the Earth's surface and at different altitudes, in precipitation, in ozone concentration, and in primary plant productivity caused by geoengineering.

  5. Inorganic sulfur-nitrogen compounds: from gunpowder chemistry to the forefront of biological signaling.

    PubMed

    Cortese-Krott, Miriam M; Butler, Anthony R; Woollins, J Derek; Feelisch, Martin

    2016-04-14

    The reactions between inorganic sulfur and nitrogen-bearing compounds to form S-N containing species have a long history and, besides assuming importance in industrial synthetic processes, are of relevance to microbial metabolism; waste water treatment; aquatic, soil and atmospheric chemistry; and combustion processes. The recent discovery that hydrogen sulfide and nitric oxide exert often similar, sometimes mutually dependent effects in a variety of biological systems, and that the chemical interaction of these two species leads to formation of S-N compounds brought this chemistry to the attention of physiologists, biochemists and physicians. We here provide a perspective about the potential role of S-N compounds in biological signaling and briefly review their chemical properties and bioactivities in the context of the chronology of their discovery. Studies of the biological role of NO revealed why its chemistry is ideally suited for the tasks Nature has chosen for it; realising how the distinctive properties of sulfur can enrich this bioactivity does much to revive 'die Freude am experimentellen Spiel' of the pioneers in this field. PMID:26898846

  6. Olfactometry Profiles and Quantitation of Volatile Sulfur Compounds of Swiss Tilsit Cheeses.

    PubMed

    Fuchsmann, Pascal; Stern, Mireille Tena; Brügger, Yves-Alain; Breme, Katharina

    2015-09-01

    To establish the odor profiles of three differently fabricated commercial Swiss Tilsit cheeses, analyses were conducted using headspace solid-phase microextraction gas chromatography-mass spectrometry/pulsed flame photometric detection and gas chromatography-olfactometry to identify and quantitate volatile compounds. In addition, odor quality and the impact of target sulfur compounds on the overall odor of the cheeses were investigated. The odor profile was found to be mainly influenced by buttery-cheesy and sulfury odor notes in all cheeses. Buttery-cheesy odor notes were attributed to three main molecules: butanoic acid, 3-methylbutanoic acid, and butane-2,3-dione. Over a dozen volatile sulfur compounds were detected at parts per billion levels, but only a few influenced the odor profile of the cheeses: methanethiol, dimethyl disulfide, bis(methylthio)methane, dimethyl trisulfide, 3-(methylthio)propanal, and 2-methyltetrahydrothiophen-3-one (tentative). In conclusion, the conducted analyses allowed differentiation of the cheeses, and gas chromatography-olfactometry results confirmed that partially thermized milk cheese has a more intense and more multifaceted overall flavor. PMID:26230142

  7. Genome-Wide Transcriptional Profiling of the Purple Sulfur Bacterium Allochromatium vinosum DSM 180T during Growth on Different Reduced Sulfur Compounds

    PubMed Central

    Weissgerber, Thomas; Dobler, Nadine; Polen, Tino; Latus, Jeanette; Stockdreher, Yvonne

    2013-01-01

    The purple sulfur bacterium Allochromatium vinosum DSM 180T is one of the best-studied sulfur-oxidizing anoxygenic phototrophic bacteria, and it has been developed into a model organism for laboratory-based studies of oxidative sulfur metabolism. Here, we took advantage of the organism's high metabolic versatility and performed whole-genome transcriptional profiling to investigate the response of A. vinosum cells upon exposure to sulfide, thiosulfate, elemental sulfur, or sulfite compared to photoorganoheterotrophic growth on malate. Differential expression of 1,178 genes was observed, corresponding to 30% of the A. vinosum genome. Relative transcription of 551 genes increased significantly during growth on one of the different sulfur sources, while the relative transcript abundance of 627 genes decreased. A significant number of genes that revealed strongly enhanced relative transcription levels have documented sulfur metabolism-related functions. Among these are the dsr genes, including dsrAB for dissimilatory sulfite reductase, and the sgp genes for the proteins of the sulfur globule envelope, thus confirming former results. In addition, we identified new genes encoding proteins with appropriate subcellular localization and properties to participate in oxidative dissimilatory sulfur metabolism. Those four genes for hypothetical proteins that exhibited the strongest increases of mRNA levels on sulfide and elemental sulfur, respectively, were chosen for inactivation and phenotypic analyses of the respective mutant strains. This approach verified the importance of the encoded proteins for sulfur globule formation during the oxidation of sulfide and thiosulfate and thereby also documented the suitability of comparative transcriptomics for the identification of new sulfur-related genes in anoxygenic phototrophic sulfur bacteria. PMID:23873913

  8. Compound-specific sulfur isotope analysis of thiadiamondoids of oils from the Smackover Formation, USA

    NASA Astrophysics Data System (ADS)

    Gvirtzman, Zvi; Said-Ahmad, Ward; Ellis, Geoffrey S.; Hill, Ronald J.; Moldowan, J. Michael; Wei, Zhibin; Amrani, Alon

    2015-10-01

    Thiadiamondoids (TDs) are diamond-like compounds with a sulfide bond located within the cage structure. These compounds were suggested as a molecular proxy for the occurrence and extent of thermochemical sulfate reduction (TSR). Compound-specific sulfur-isotope analysis of TDs may create a multi-parameter system, based on molecular and δ34S values that may be sensitive over a wider range of TSR and thermal maturation stages. In this study, we analyzed a suite of 12 Upper Jurassic oil and condensate samples generated from source rocks in the Smackover Formation to perform a systematic study of the sulfur isotope distribution in thiadiamondoids (one and two cages). For comparison we measured the δ34S composition of benzothiophenes (BTs) and dibenzothiophenes (DBTs). We also conducted pyrolysis experiments with petroleum and model compounds to have an insight into the formation mechanisms of TDs. The δ34S of the TDs varied significantly (ca 30‰) between the different oils depending on the degree of TSR alteration. The results showed that within the same oil, the one-cage TDs were relatively uniform, with 34S enriched values similar to those of the coexisting BTs. The two-cage TDs had more variable δ34S values that range from the δ34S values of BTs to those of the DBTs, but with general 34S depletion relative to one cage TDs. Hydrous pyrolysis experiments (360 °C, 40 h) with either CaSO4 or elemental S (equivalent S molar concentrations) and adamantane as a model compound demonstrate the formation of one cage TDs in relatively low yields (<0.2%). Higher concentrations of TDs were observed in the elemental sulfur experiments, most likely because of the higher rates of reaction with adamantane under these experimental conditions. These results show that the formation of TDs is not exclusive to TSR reactions, and that they can also form by reaction with reduced S species apart from sulfate reduction, though at low yields. Oxygenated compounds, most notably 2-thiaadamantanone and phenol, were also formed during these pyrolysis experiments. This may represent the first stage in the formation of sulfurized compounds and the oxidation of organic matter under TSR conditions. Pyrolysis experiments with elemental S and a TD-enriched oil showed that the δ34S values of the TDs did not change, whereas the BTs did change significantly. It is therefore concluded that TDs do not exchange S atoms with coexisting inorganic reduced sulfur species. They can only change their δ34S values via addition of newly generated TDs that form predominantly during TSR. We therefore suggest that TDs will preserve their δ34S values even under high-temperature reservoir conditions and will reflect the original sulfates δ34S value. The combination of TDs, BTs, and DBTs δ34S values and concentrations allowed for a more reliable detection of the occurrence and extent of TSR than either proxy alone. It showed that except for two oils, all of the oils that were measured in this study were affected by TSR or TSR-sourced H2S, to some degree. It is still not known if some of the oils with the lower concentrations of TDs and enriched δ34S values (close to sulfate minerals) were affected by TSR or by a secondary charge of 34S-enriched H2S.

  9. Compound-specific sulfur isotope analysis of thiadiamondoids of oils from the Smackover Formation, USA

    USGS Publications Warehouse

    Zvi Gvirtzman; Ward Said-Ahmad; Ellis, Geoffrey S.; Ronald J. Hill; J. Michael Moldowan; Zhibin Wei; Alon Amrani

    2015-01-01

    Thiadiamondoids (TDs) are diamond-like compounds with a sulfide bond located within the cage structure. These compounds were suggested as a molecular proxy for the occurrence and extent of thermochemical sulfate reduction (TSR). Compound-specific sulfur-isotope analysis of TDs may create a multi-parameter system, based on molecular and δ34S values that may be sensitive over a wider range of TSR and thermal maturation stages. In this study, we analyzed a suite of 12 Upper Jurassic oil and condensate samples generated from source rocks in the Smackover Formation to perform a systematic study of the sulfur isotope distribution in thiadiamondoids (one and two cages). For comparison we measured the δ34S composition of benzothiophenes (BTs) and dibenzothiophenes (DBTs). We also conducted pyrolysis experiments with petroleum and model compounds to have an insight into the formation mechanisms of TDs. The δ34S of the TDs varied significantly (ca 30‰) between the different oils depending on the degree of TSR alteration. The results showed that within the same oil, the one-cage TDs were relatively uniform, with 34S enriched values similar to those of the coexisting BTs. The two-cage TDs had more variable δ34S values that range from the δ34S values of BTs to those of the DBTs, but with general 34S depletion relative to one cage TDs. Hydrous pyrolysis experiments (360 °C, 40 h) with either CaSO4 or elemental S (equivalent S molar concentrations) and adamantane as a model compound demonstrate the formation of one cage TDs in relatively low yields (<0.2%). Higher concentrations of TDs were observed in the elemental sulfur experiments, most likely because of the higher rates of reaction with adamantane under these experimental conditions. These results show that the formation of TDs is not exclusive to TSR reactions, and that they can also form by reaction with reduced S species apart from sulfate reduction, though at low yields. Oxygenated compounds, most notably 2-thiaadamantanone and phenol, were also formed during these pyrolysis experiments. This may represent the first stage in the formation of sulfurized compounds and the oxidation of organic matter under TSR conditions. Pyrolysis experiments with elemental S and a TD-enriched oil showed that the δ34S values of the TDs did not change, whereas the BTs did change significantly. It is therefore concluded that TDs do not exchange S atoms with coexisting inorganic reduced sulfur species. They can only change their δ34S values via addition of newly generated TDs that form predominantly during TSR. We therefore suggest that TDs will preserve their δ34S values even under high-temperature reservoir conditions and will reflect the original sulfates δ34S value. The combination of TDs, BTs, and DBTs δ34S values and concentrations allowed for a more reliable detection of the occurrence and extent of TSR than either proxy alone. It showed that except for two oils, all of the oils that were measured in this study were affected by TSR or TSR-sourced H2S, to some degree. It is still not known if some of the oils with the lower concentrations of TDs and enriched δ34S values (close to sulfate minerals) were affected by TSR or by a secondary charge of 34S-enriched H2S.

  10. Observation of dipropenyldisulfide and other organic sulfur compounds in the atmosphere of a beech forest with Allium ursinum ground cover

    NASA Astrophysics Data System (ADS)

    Puxbaum, H.; König, G.

    Dipropenyldisulfide, methylpropenyldisulfide, cis-propenylpropyldisulfide, diallylsulfide, dimethyldisulfide and 3-methylthiopropene were detected in the atmosphere of a beech forest with Allium ursinum (broad-leaved garlic) ground cover plants. Furthermore, it was shown that the Allium plants were the source of the organic sulfur compounds. The atmospheric concentrations of the organic sulfur observed on one day in May 1994 in a suburban forest in Vienna ranged from 0.3 to 7.8 ppb S with an average level of 2.9 ppb S. The atmospheric emission rate of organic sulfur species from A. ursinum determined with an enclosure box was the highest ever reported for terrestrial continental plants. The total organic sulfur flux on the average was at least 1 jug g-1h-1 (plant dry weight) or 60 gmgm-2 h-1 (per unit of ground area).

  11. Detection and classification of gaseous sulfur compounds by solid electrolyte cyclic voltammetry of cermet sensor array.

    PubMed

    Kramer, Kirsten E; Rose-Pehrsson, Susan L; Hammond, Mark H; Tillett, Duane; Streckert, Holger H

    2007-02-12

    Electrochemical sensors composed of a ceramic-metallic (cermet) solid electrolyte are used for the detection of gaseous sulfur compounds SO(2), H(2)S, and CS(2) in a study involving 11 toxic industrial chemical (TIC) compounds. The study examines a sensor array containing four cermet sensors varying in electrode-electrolyte composition, designed to offer selectivity for multiple compounds. The sensors are driven by cyclic voltammetry to produce a current-voltage profile for each analyte. Raw voltammograms are processed by background subtraction of clean air, and the four sensor signals are concatenated to form one vector of points. The high-resolution signal is compressed by wavelet transformation and a probabilistic neural network is used for classification. In this study, training data from one sensor array was used to formulate models which were validated with data from a second sensor array. Of the 11 gases studied, 3 that contained sulfur produced the strongest responses and were successfully analyzed when the remaining compounds were treated as interferents. Analytes were measured from 10 to 200% of their threshold-limited value (TLV) according to the 8-h time weighted average (TWA) exposure limits defined by the National Institute of Occupational Safety and Health (NIOSH). True positive classification rates of 93.3, 96.7, and 76.7% for SO(2), H(2)S, and CS(2), respectively, were achieved for prediction of one sensor unit when a second sensor was used for modeling. True positive rates of 83.3, 90.0, and 90.0% for SO(2), H(2)S, and CS(2), respectively, were achieved for the second sensor unit when the first sensor unit was used for modeling. Most of the misclassifications were for low concentration levels (such 10-25% TLV) in which case the compound was classified as clean air. Between the two sensors, the false positive rates were 2.2% or lower for the three sulfur compounds, 0.9% or lower for the interferents (eight remaining analytes), and 5.8% or lower for clean air. The cermet sensor arrays used in this analysis are rugged, low cost, reusable, and show promise for multiple compound detection at parts-per-million (ppm) levels. PMID:17386588

  12. ADVANCED SULFUR CONTROL CONCEPTS

    SciTech Connect

    Apostolos A. Nikolopoulos; Santosh K. Gangwal; William J. McMichael; Jeffrey W. Portzer

    2003-01-01

    Conventional sulfur removal in integrated gasification combined cycle (IGCC) power plants involves numerous steps: COS (carbonyl sulfide) hydrolysis, amine scrubbing/regeneration, Claus process, and tail-gas treatment. Advanced sulfur removal in IGCC systems involves typically the use of zinc oxide-based sorbents. The sulfides sorbent is regenerated using dilute air to produce a dilute SO{sub 2} (sulfur dioxide) tail gas. Under previous contracts the highly effective first generation Direct Sulfur Recovery Process (DSRP) for catalytic reduction of this SO{sub 2} tail gas to elemental sulfur was developed. This process is currently undergoing field-testing. In this project, advanced concepts were evaluated to reduce the number of unit operations in sulfur removal and recovery. Substantial effort was directed towards developing sorbents that could be directly regenerated to elemental sulfur in an Advanced Hot Gas Process (AHGP). Development of this process has been described in detail in Appendices A-F. RTI began the development of the Single-step Sulfur Recovery Process (SSRP) to eliminate the use of sorbents and multiple reactors in sulfur removal and recovery. This process showed promising preliminary results and thus further process development of AHGP was abandoned in favor of SSRP. The SSRP is a direct Claus process that consists of injecting SO{sub 2} directly into the quenched coal gas from a coal gasifier, and reacting the H{sub 2}S-SO{sub 2} mixture over a selective catalyst to both remove and recover sulfur in a single step. The process is conducted at gasifier pressure and 125 to 160 C. The proposed commercial embodiment of the SSRP involves a liquid phase of molten sulfur with dispersed catalyst in a slurry bubble-column reactor (SBCR).

  13. Future Sulfur Dioxide Emissions

    SciTech Connect

    Smith, Steven J.; Pitcher, Hugh M.; Wigley, Tom M.

    2005-12-01

    The importance of sulfur dioxide emissions for climate change is now established, although substantial uncertainties remain. This paper presents projections for future sulfur dioxide emissions using the MiniCAM integrated assessment model. A new income-based parameterization for future sulfur dioxide emissions controls is developed based on purchasing power parity (PPP) income estimates and historical trends related to the implementation of sulfur emissions limitations. This parameterization is then used to produce sulfur dioxide emissions trajectories for the set of scenarios developed for the Special Report on Emission Scenarios (SRES). We use the SRES methodology to produce harmonized SRES scenarios using the latest version of the MiniCAM model. The implications, and requirements, for IA modeling of sulfur dioxide emissions are discussed. We find that sulfur emissions eventually decline over the next century under a wide set of assumptions. These emission reductions result from a combination of emission controls, the adoption of advanced electric technologies, and a shift away from the direct end use of coal with increasing income levels. Only under a scenario where incomes in developing regions increase slowly do global emission levels remain at close to present levels over the next century. Under a climate policy that limits emissions of carbon dioxide, sulfur dioxide emissions fall in a relatively narrow range. In all cases, the relative climatic effect of sulfur dioxide emissions decreases dramatically to a point where sulfur dioxide is only a minor component of climate forcing by the end of the century. Ecological effects of sulfur dioxide, however, could be significant in some developing regions for many decades to come.

  14. Sulfur: its clinical and toxicologic aspects.

    PubMed

    Komarnisky, Lioudmila A; Christopherson, Robert J; Basu, Tapan K

    2003-01-01

    Although there is no known dietary requirement for inorganic sulfur, it is an essential element for all animal species in as much as they all require the sulfur-containing amino acid methionine. There are three predominate forms of organic sulfur in animals and humans: 1). the thiomethyl of methionine residues in protein; 2). the sulfhydryl disulfides of protein; and 3). the compounds containing ester or amide bound sulfates of glycosaminoglycans, steroids, and many xenobiotic metabolites. Thus, sulfur becomes an important constituent of amino acids, proteins, enzymes, vitamins and other biomolecules. Unlike mammalian species, plants can use inorganic sulfur and synthesize methionine from which are synthesized all the other important sulfur compounds. Hence, sulfur deficiency occurs mainly when plants are grown in sulfur-depleted soils and when humans and animals consume low-protein diets. In recent times, however, the increasing prevalence of refining petroleum and smelting sulfur compounds of metallic minerals into free metals are having a large impact on the balance of sulfur in the environment. Sulfur toxicity is associated mainly with high levels of the element and its toxic volatile substances in the environment. Sulfur dioxide (SO(2)), a major air pollutant, may adversely affect animal and human health by causing bronchitis, bronchoconstriction, and increased pulmonary resistance. PMID:12507640

  15. Process for reducing sulfur in coal char

    DOEpatents

    Gasior, Stanley J.; Forney, Albert J.; Haynes, William P.; Kenny, Richard F.

    1976-07-20

    Coal is gasified in the presence of a small but effective amount of alkaline earth oxide, hydroxide or carbonate to yield a char fraction depleted in sulfur. Gases produced during the reaction are enriched in sulfur compounds and the alkaline earth compound remains in the char fraction as an alkaline earth oxide. The char is suitable for fuel use, as in a power plant, and during combustion of the char the alkaline earth oxide reacts with at least a portion of the sulfur oxides produced from the residual sulfur contained in the char to further lower the sulfur content of the combustion gases.

  16. A kinetic and thermochemical database for organic sulfur and oxygen compounds.

    PubMed

    Class, Caleb A; Aguilera-Iparraguirre, Jorge; Green, William H

    2015-05-28

    Potential energy surfaces and reaction kinetics were calculated for 40 reactions involving sulfur and oxygen. This includes 11 H2O addition, 8 H2S addition, 11 hydrogen abstraction, 7 beta scission, and 3 elementary tautomerization reactions, which are potentially relevant in the combustion and desulfurization of sulfur compounds found in various fuel sources. Geometry optimizations and frequencies were calculated for reactants and transition states using B3LYP/CBSB7, and potential energies were calculated using CBS-QB3 and CCSD(T)-F12a/VTZ-F12. Rate coefficients were calculated using conventional transition state theory, with corrections for internal rotations and tunneling. Additionally, thermochemical parameters were calculated for each of the compounds involved in these reactions. With few exceptions, rate parameters calculated using the two potential energy methods agreed reasonably, with calculated activation energies differing by less than 5 kJ mol(-1). The computed rate coefficients and thermochemical parameters are expected to be useful for kinetic modeling. PMID:25941683

  17. Enhanced elemental mercury removal from coal-fired flue gas by sulfur-chlorine compounds

    SciTech Connect

    Nai-Qiang Yan; Zan Qu; Yao Chi; Shao-Hua Qiao; Ray L. Dod; Shih-Ger Chang; Charles Miller

    2009-07-15

    Oxidation of Hg{sup 0} with any oxidant or converting it to a particle-bound form can facilitate its removal. Two sulfur-chlorine compounds, sulfur dichloride (SCl{sub 2}) and sulfur monochloride (S{sub 2}Cl{sub 2}), were investigated as oxidants for Hg{sup 0} by gas-phase reaction and by surface-involved reactions in the presence of flyash or activated carbon. The gas-phase reaction between Hg{sup 0} and SCl{sub 2} is shown to be more rapid than the gas-phase reaction with chlorine, and the second order rate constant was 9.1({+-}0.5) x 10{sup -18} mL-molecules{sup -1}.s{sup -1} at 373 K. The presence of flyash or powdered activated carbon in flue gas can substantially accelerate the reaction. The predicted Hg{sup 0} removal is about 90% with 5 ppm SCl {sub 2} or S{sub 2}Cl{sub 2} and 40 g/m{sup 3} of flyash in flue gas. The combination of activated carbon and sulfur-chlorine compounds is an effective alternative. We estimate that co-injection of 3-5 ppm of SCl{sub 2} (or S{sub 2}Cl{sub 2}) with 2-3 Lb/MMacf of untreated Darco-KB is comparable in efficiency to the injection of 2-3 Lb/MMacf Darco-Hg-LH. Extrapolation of kinetic results also indicates that 90% of Hg{sup 0} can be removed if 3 Lb/MMacf of Darco-KB pretreated with 3% of SCl{sub 2} or S{sub 2}Cl{sub 2} is used. Mercuric sulfide was identified as one of the principal products of the Hg{sup 0}/SCl{sub 2} or Hg{sup 0}/S{sub 2}Cl{sub 2} reactions. Additionally, about 8% of SCl{sub 2} or S{sub 2}Cl{sub 2} in aqueous solutions is converted to sulfide ions, which would precipitate mercuric ion from FGD solution. 14 refs., 5 figs., 1 tab.

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

    NASA Astrophysics Data System (ADS)

    Garces Trujillo, Hector Fabian

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

  19. Microbial removal of organic sulfur from coal (degradation of sulfur-containing heterocyclic compounds). Final report, July 1, 1984-June 30, 1985

    SciTech Connect

    Klubek, B.; Clark, D.

    1985-09-01

    The presence of substantial levels of sulfur in coal is a major source of air pollution, and considerable efforts are being made to devise a cost-effective way of removing the sulfur. One promising method is the microbial desulfurization of coal. Recent research has shown that it is possible to remove almost all of the inorganic sulfur from coal using the bacteria Thiobacillus or Sulfolobus. These organisms convert sulfide to sulfate but leave the organic sulfur untouched. Since certain coals, including those in the Illinois Basin, contain high levels of organic sulfur, its removal is also necessary. If a strain of bacteria could be found or developed which would effectively remove organic sulfur from coal, then, when used in conjunction with an organism which removes inorganic sulfur, it could result in an effective desulfurization method. Several approaches are used in developing bacteria which remove organic sulfur. One method is to isolate suitable naturally occurring bacterial species; another is to mutate a laboratory species, Escherichia coli, an organism which is genetically well understood and whose pathways for the metabolism of sulfur-containing amino acids have been extensively investigated. The objectives of this study were threefold: (1) to isolate thiophene-oxidizing bacteria from the natural environment and to identify the optimal growth conditions for thiophene oxidation; (2) to construct novel biosynthetic pathways for organic sulfur utilization in Escherichia coli via successive cycles of mutation; and (3) from objectives 1 and 2, to construct a bacterial organism that will be efficient in the removal of organic sulfur from coal. 3 refs., 13 figs., 9 tabs.

  20. The Phases of Sulfur.

    ERIC Educational Resources Information Center

    Birdwhistell, Kurt R.

    1995-01-01

    Presents a demonstration that illustrates the dramatic changes that sulfur undergoes upon heating to 200 degrees centigrade and then cooling to room temperature. Supplements the demonstration of the rubberlike properties of catenasulfur made by rapid cooling of the sulfur melt in ice water. (JRH)

  1. Advanced sulfur control concepts

    SciTech Connect

    Gangwal, S.K.; Turk, B.S.; Gupta, R.P.

    1995-11-01

    Regenerable metal oxide sorbents, such as zinc titanate, are being developed to efficiently remove hydrogen sulfide (H{sub 2}S) from coal gas in advanced power systems. Dilute air regeneration of the sorbents produces a tailgas containing a few percent sulfur dioxide (SO{sub 2}). Catalytic reduction of the SO{sub 2} to elemental sulfur with a coal gas slipstream using the Direct Sulfur Recovery Process (DSRP) is a leading first-generation technology. Currently the DSRP is undergoing field testing at gasifier sites. The objective of this study is to develop second-generation processes that produce elemental sulfur without coal gas or with limited use. Novel approaches that were evaluated to produce elemental sulfur from sulfided sorbents include (1) sulfur dioxide (SO{sub 2}) regeneration, (2) substoichiometric (partial) oxidation, (3) steam regeneration followed by H{sub 2}S oxidation, and (4) steam-air regeneration. Preliminary assessment of these approaches indicated that developing SO{sub 2} regeneration faced the fewest technical and economic problems among the four process options. Elemental sulfur is the only likely product of SO{sub 2} regeneration and the SO{sub 2} required for the regeneration can be obtained by burning a portion of the sulfur produced. Experimental efforts have thus been concentrated on SO{sub 2}-based regeneration processes. Results from laboratory investigations are presented and discussed.

  2. Sulfur isotopic data

    SciTech Connect

    Rye, R.O.

    1987-01-01

    Preliminary sulfur isotope data have been determined for samples of the Vermillion Creek coal bed and associated rocks in the Vermillion Creek basin and for samples of evaporites collected from Jurassic and Triassic formations that crop out in the nearby Uinta Mountains. The data are inconclusive, but it is likely that the sulfur in the coal was derived from the evaporites.

  3. Field sampling method for quantifying volatile sulfur compounds from animal feeding operations

    NASA Astrophysics Data System (ADS)

    Trabue, Steven; Scoggin, Kenwood; Mitloehner, Frank; Li, Hong; Burns, Robert; Xin, Hongwei

    Volatile sulfur compounds (VSCs) are a major class of chemicals associated with odor from animal feeding operations (AFOs). Identifying and quantifying VSCs in air is challenging due to their volatility, reactivity, and low concentrations. In the present study, a canister-based method collected whole air in fused silica-lined (FSL) mini-canister (1.4 L) following passage through a calcium chloride drying tube. Sampled air from the canisters was removed (10-600 mL), dried, pre-concentrated, and cryofocused into a GC system with parallel detectors (mass spectrometer (MS) and pulsed flame photometric detector (PFPD)). The column effluent was split 20:1 between the MS and PFPD. The PFPD equimolar sulfur response enhanced quantitation and the location of sulfur peaks for mass spectral identity and quantitation. Limit of quantitation for the PFPD and MSD was set at the least sensitive VSC (hydrogen sulfide) and determined to be 177 and 28 pg S, respectively, or 0.300 and 0.048 μg m -3 air, respectively. Storage stability of hydrogen sulfide and methanethiol was problematic in warm humid air (25 °C, 96% relative humidity (RH)) without being dried first, however, stability in canisters dried was still only 65% after 24 h of storage. Storage stability of hydrogen sulfide sampled in the field at a swine facility was over 2 days. The greater stability of field samples compared to laboratory samples was due to the lower temperature and RH of field samples compared to laboratory generated samples. Hydrogen sulfide was the dominant odorous VSCs detected at all swine facilities with methanethiol and dimethyl sulfide detected notably above their odor threshold values. The main odorous VSC detected in aged poultry litter was dimethyl trisulfide. Other VSCs above odor threshold values for poultry facilities were methanethiol and dimethyl sulfide.

  4. Nanostructured sulfur cathodes.

    PubMed

    Yang, Yuan; Zheng, Guangyuan; Cui, Yi

    2013-04-01

    Rechargeable Li/S batteries have attracted significant attention lately due to their high specific energy and low cost. They are promising candidates for applications, including portable electronics, electric vehicles and grid-level energy storage. However, poor cycle life and low power capability are major technical obstacles. Various nanostructured sulfur cathodes have been developed to address these issues, as they provide greater resistance to pulverization, faster reaction kinetics and better trapping of soluble polysulfides. In this review, recent developments on nanostructured sulfur cathodes and mechanisms behind their operation are presented and discussed. Moreover, progress on novel characterization of sulfur cathodes is also summarized, as it has deepened the understanding of sulfur cathodes and will guide further rational design of sulfur electrodes. PMID:23325336

  5. Aircraft exhaust sulfur emissions

    NASA Astrophysics Data System (ADS)

    Brown, R. C.; Anderson, M. R.; Miake-Lye, R. C.; Kolb, C. E.; Sorokin, A. A.; Buriko, Y. Y.

    The conversion of fuel sulfur to S(VI) (SO3 + H2SO4) in supersonic and subsonic aircraft engines is estimated numerically. Model results indicate between 2% and 10% of the fuel sulfur is emitted as S(VI). It is also shown that, for a high sulfur mass loading, conversion in the turbine is kinetically limited by the level of atomic oxygen. This results in a higher oxidation efficiency at lower sulfur loadings. SO3 is the primary S(VI) oxidation product and calculated H2SO4 emission levels were less than 1% of the total fuel sulfur. This source of S(VI) can exceed the S(VI) source due to gas phase oxidation in the exhaust wake.

  6. Elemental sulfur recovery process

    DOEpatents

    Flytzani-Stephanopoulos, M.; Zhicheng Hu.

    1993-09-07

    An improved catalytic reduction process for the direct recovery of elemental sulfur from various SO[sub 2]-containing industrial gas streams. The catalytic process provides combined high activity and selectivity for the reduction of SO[sub 2] to elemental sulfur product with carbon monoxide or other reducing gases. The reaction of sulfur dioxide and reducing gas takes place over certain catalyst formulations based on cerium oxide. The process is a single-stage, catalytic sulfur recovery process in conjunction with regenerators, such as those used in dry, regenerative flue gas desulfurization or other processes, involving direct reduction of the SO[sub 2] in the regenerator off gas stream to elemental sulfur in the presence of a catalyst. 4 figures.

  7. Elemental sulfur recovery process

    DOEpatents

    Flytzani-Stephanopoulos, Maria; Hu, Zhicheng

    1993-01-01

    An improved catalytic reduction process for the direct recovery of elemental sulfur from various SO.sub.2 -containing industrial gas streams. The catalytic process provides combined high activity and selectivity for the reduction of SO.sub.2 to elemental sulfur product with carbon monoxide or other reducing gases. The reaction of sulfur dioxide and reducing gas takes place over certain catalyst formulations based on cerium oxide. The process is a single-stage, catalytic sulfur recovery process in conjunction with regenerators, such as those used in dry, regenerative flue gas desulfurization or other processes, involving direct reduction of the SO.sub.2 in the regenerator off gas stream to elemental sulfur in the presence of a catalyst.

  8. Sulfur in Cometary Dust

    NASA Technical Reports Server (NTRS)

    Fomenkova, M. N.

    1997-01-01

    The computer-intensive project consisted of the analysis and synthesis of existing data on composition of comet Halley dust particles. The main objective was to obtain a complete inventory of sulfur containing compounds in the comet Halley dust by building upon the existing classification of organic and inorganic compounds and applying a variety of statistical techniques for cluster and cross-correlational analyses. A student hired for this project wrote and tested the software to perform cluster analysis. The following tasks were carried out: (1) selecting the data from existing database for the proposed project; (2) finding access to a standard library of statistical routines for cluster analysis; (3) reformatting the data as necessary for input into the library routines; (4) performing cluster analysis and constructing hierarchical cluster trees using three methods to define the proximity of clusters; (5) presenting the output results in different formats to facilitate the interpretation of the obtained cluster trees; (6) selecting groups of data points common for all three trees as stable clusters. We have also considered the chemistry of sulfur in inorganic compounds.

  9. Regional river sulfur runoff

    SciTech Connect

    Husar, R.B.; Husar, J.D.

    1985-01-20

    The water and sulfur runoff data for 54 large river basins were assembled, covering 65% of the nondesert land area of the world. The sulfur concentration ranges from 0.5 mg S/L for the West African rivers Niger and Volta to 100 mg S/L in the Colorado River; the world average is 3.2 mg S/L. The concentrations in central and eastern Europe as well as central and eastern North America exceed 8 mg S/L. The sulfur runoff density is also highest in the river basins over these industrialized regions, exceeding 2 g S/m/sup 2//yr. However, high sulfur runoff density in excess of 3 g S/m/sup 2//yr is also measured over the Pacific islands New Zealand and New Guinea and the archipelagos of Indonesia and the Philippines. The natural background sulfur runoff was estimated by assuming that South America, Africa, Australia, and the Pacific Islands are unperturbed by man and that the average river sulfur concentration is in the range 1--3 mg S/L. Taking these background concentration values, the man-induced sulfur runoff for Europe ranges between 2 and 8 times the natural flow, and over North America, man's contribution ranges between 1 and 5 times the natural runoff. The global sulfur flow from nondesert land to the oceans and the Caspian Sea is estimated as 131 Tg S/yr, of which 46--85 Tg S/yr is attributed to natural causes. The regional river sulfur runoff pattern discussed in this paper does not have enough spatial resolution to be directly applicable to studies of the environmental effects of man-induced sulfur flows. However, it points to the continental-size regions where those perturbations are most evident and to the magnitude of the perturbations as expressed in units of the natural flows.

  10. Evolutions of volatile sulfur compounds of Cabernet Sauvignon wines during aging in different oak barrels.

    PubMed

    Ye, Dong-Qing; Zheng, Xiao-Tian; Xu, Xiao-Qing; Wang, Yun-He; Duan, Chang-Qing; Liu, Yan-Lin

    2016-07-01

    The evolution of volatile sulfur compounds (VSCs) in Cabernet Sauvignon wines from seven regions of China during maturation in oak barrels was investigated. The barrels were made of different wood grains (fine and medium) and toasting levels (light and medium). Twelve VSCs were quantified by GC/FPD, with dimethyl sulfide (DMS) and methionol exceeding their sensory thresholds. Most VSCs tended to decline during the aging, while DMS was found to increase. After one year aging, the levels of DMS, 2-methyltetrahy-drothiophen-3-one and sulfur-containing esters were lower in the wines aged in oak barrels than in stainless steel tanks. The wood grain and toasting level of oak barrels significantly influenced the concentration of S-methyl thioacetate and 2-methyltetrahy-drothiophen-3-one. This study reported the evolution of VSCs in wines during oak barrel aging for the first time and evaluated the influence of barrel types, which would provide wine-makers with references in making proposals about wine aging. PMID:26920290

  11. Engineering synthetic bacterial consortia for enhanced desulfurization and revalorization of oil sulfur compounds.

    PubMed

    Martínez, Igor; Mohamed, Magdy El-Said; Rozas, Daniel; García, José Luis; Díaz, Eduardo

    2016-05-01

    The 4S pathway is the most studied bioprocess for the removal of the recalcitrant sulfur of aromatic heterocycles present in fuels. It consists of three sequential functional units, encoded by the dszABCD genes, through which the model compound dibenzothiophene (DBT) is transformed into the sulfur-free 2-hydroxybiphenyl (2HBP) molecule. In this work, a set of synthetic dsz cassettes were implanted in Pseudomonas putida KT2440, a model bacterial "chassis" for metabolic engineering studies. The complete dszB1A1C1-D1 cassette behaved as an attractive alternative - to the previously constructed recombinant dsz cassettes - for the conversion of DBT into 2HBP. Refactoring the 4S pathway by the use of synthetic dsz modules encoding individual 4S pathway reactions revealed unanticipated traits, e.g., the 4S intermediate 2HBP-sulfinate (HBPS) behaves as an inhibitor of the Dsz monooxygenases, and once secreted from the cells it cannot be further taken up. That issue should be addressed for the rational design of more efficient biocatalysts for DBT bioconversions. In this sense, the construction of synthetic bacterial consortia to compartmentalize the 4S pathway into different cell factories for individual optimization was shown to enhance the conversion of DBT into 2HBP, overcome the inhibition of the Dsz enzymes by the 4S intermediates, and enable efficient production of unattainable high added value intermediates, e.g., HBPS, that are difficult to obtain using the current monocultures. PMID:26802977

  12. Thermophilic biodesulfurization of various heterocyclic sulfur compounds and crude straight-run light gas oil fraction by a newly isolated strain Mycobacterium phlei WU-0103.

    PubMed

    Ishii, Yoshitaka; Kozaki, Shinya; Furuya, Toshiki; Kino, Kuniki; Kirimura, Kohtaro

    2005-02-01

    Various heterocyclic sulfur compounds such as naphtho[2,1-b]thiophene (NTH) and benzo[b]thiophene (BTH) derivatives can be detected in diesel oil, in addition to dibenzothiophene (DBT) derivatives. Mycobacterium phlei WU-0103 was newly isolated as a bacterial strain capable of growing in a medium with NTH as the sulfur source at 50 degrees C. M. phlei WU-0103 could degrade various heterocyclic sulfur compounds, not only NTH and its derivatives but also DBT, BTH, and their derivatives at 45 degrees C. When M. phlei WU-0103 was cultivated with the heterocyclic sulfur compounds such as NTH, NTH 3,3-dioxide, DBT, BTH, and 4,6-dialkylDBTs as sulfur sources, monohydroxy compounds and sulfone compounds corresponding to starting heterocyclic sulfur compounds were detected by gas chromatography-mass spectrometry analysis, suggesting the sulfur-specific desulfurization pathways for heterocyclic sulfur compounds. Moreover, total sulfur content in 12-fold-diluted crude straight-run light gas oil fraction was reduced from 1000 to 475 ppm S, with 52% reduction, by the biodesulfurization treatment at 45 degrees C with growing cells of M. phlei WU-0103. Gas chromatography analysis with a flame photometric detector revealed that most of the resolvable peaks, such as those corresponding to alkylated derivatives of NTH, DBT, and BTH, disappeared after the biodesulfurization treatment. These results indicated that M. phlei WU-0103 may have a good potential as a biocatalyst for practical biodesulfurization of diesel oil. PMID:15702256

  13. Studies on the Low-Temp Oxidation of Coal Containing Organic Sulfur and the Corresponding Model Compounds.

    PubMed

    Zhang, Lanjun; Li, Zenghua; Li, Jinhu; Zhou, Yinbo; Yang, Yongliang; Tang, Yibo

    2015-01-01

    This paper selects two typical compounds containing organic sulfur as model compounds. Then, by analyzing the chromatograms of gaseous low-temp oxidation products and GC/MS of the extractable matter of the oxidation residue, we summarizing the mechanism of low-temp sulfur model compound oxidation. The results show that between 30 °C to 80 °C, the interaction between diphenyl sulfide and oxygen is mainly one of physical adsorption. After 80 °C, chemical adsorption and chemical reactions begin. The main reaction mechanism in the low-temp oxidation of the model compound diphenyl sulfide is diphenyl sulfide generates diphenyl sulfoxide, and then this sulfoxide is further oxidized to diphenyl sulphone. A small amount of free radicals is generated in the process. The model compound cysteine behaves differently from diphenyl sulfide. The main reaction low-temp oxidation mechanism involves the thiol being oxidized into a disulphide and finally evolving to sulfonic acid, along with SO₂ being released at 130 °C and also a small amount of free radicals. We also conducted an experiment on coal from Xingcheng using X-ray photoelectron spectroscopy (XPS). The results show that the major forms of organic sulfur in the original coal sample are thiophene and sulfone. Therefore, it can be inferred that there is none or little mercaptan and thiophenol in the original coal. After low-temp oxidation, the form of organic sulfur changes. The sulfide sulfur is oxidized to the sulfoxide, and then the sulfoxide is further oxidized to a sulfone, and these steps can be easily carried out under experimental conditions. What's more, the results illustrate that oxidation promotes sulfur element enrichment on the surface of coal. PMID:26690405

  14. Sulfuric Acid on Europa

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Frozen sulfuric acid on Jupiter's moon Europa is depicted in this image produced from data gathered by NASA's Galileo spacecraft. The brightest areas, where the yellow is most intense, represent regions of high frozen sulfuric acid concentration. Sulfuric acid is found in battery acid and in Earth's acid rain.

    This image is based on data gathered by Galileo's near infrared mapping spectrometer.

    Europa's leading hemisphere is toward the bottom right, and there are enhanced concentrations of sulfuric acid in the trailing side of Europa (the upper left side of the image). This is the face of Europa that is struck by sulfur ions coming from Jupiter's innermost moon, Io. The long, narrow features that crisscross Europa also show sulfuric acid that may be from sulfurous material extruded in cracks.

    Galileo, launched in 1989, has been orbiting Jupiter and its moons since December 1995. JPL manages the Galileo mission for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  15. Sulfur-oxygen processes on Io

    NASA Technical Reports Server (NTRS)

    Nelson, Robert M.; Smythe, William D.

    1987-01-01

    Laboratory studies of irradiated sulfur dioxide frost have found that sulfur trioxide should be formed as a consequence of the irradiation process. The spectral reflectance of solid sulfur trioxide was measured in the laboratory and it was found that the compound has strong absorption features at 3.37 and 3.70 microns. These features are not present in the spectral geometric albedo of Io. This is interpreted as an indication that sulfur trioxide may exist in such limited abundance that it is undetectable in disk averaged spectrophotometry. It is suggested that the Near-Infrared Mapping Spectrometer on the Galileo spacecraft should be able to identify condensed sulfur trioxide on Io particularly in regions bordering the sulfur dioxide deposits. The presence of elemental sulfur on Io's surface has been questioned on several grounds, most notably the suggested production process (quenched molten sulfur extrusions) and the effect of radiation (particularly X-rays) on some of the allotropes. Mixtures of sulfur allotropes were produced in the laboratory by quenching molten sulfur and it was found that the spectra indicate the presence of certain red-colored allotropes which are preserved upon quenching. The color of the sulfur glass produced is redder when the temperature of the original melt is higher. This is consistent with the suggestion that Io's spectral geometric albedo can be partly explained by the presence of quenched sulfur glasses.

  16. Liquid-phase adsorption of multi-ring thiophenic sulfur compounds on carbon materials with different surface properties.

    PubMed

    Zhou, Anning; Ma, Xiaoliang; Song, Chunshan

    2006-03-16

    This work examines the effects of structural and surface properties of carbon materials on the adsorption of benzothiophene (BT), dibenzothiophene (DBT), 4-methyldibenzothiophene (4-MDBT) and 4,6-dimethyl-dibenzothiophene (4,6-DMDBT) in the presence of 10 wt % of aromatics in liquid alkanes that simulate sulfur compounds in diesel fuels. The equilibrium-adsorption capacity varies significantly, from 1.7 to 7.0 mg-S/g-A. The results show that different carbon materials have significantly different sulfur-adsorption capacities and selectivities that depend not only on textural structure but also on surface functional groups. The adsorption of multi-ring sulfur compounds on carbon materials was found to obey the Langmuir isotherm. On the basis of adsorption tests and the characterization of carbon materials by BET and XPS, the oxygen-containing functional groups on the surface appear to play an important role in increasing sulfur-adsorption capacity. The adsorption-selectivity trend of the carbon materials for various compounds increases in the order of BT < naphthalene < 2-methylnaphthalene < DBT < 4-MDBT < 4,6-DMDBT, regardless of carbon material types. This selectivity trend for sulfur compounds is dramatically different and almost opposite from that previously observed for adsorption over nickel-based adsorbents. The regeneration of spent activated carbons was also conducted by solvent washing. The high-adsorption capacity and selectivity for methyl DBTs indicate that certain activated carbons are promising adsorbents for selective adsorption for removing sulfur (SARS) as a new approach to ultra deep desulfurization of diesel fuels. PMID:16526705

  17. The relative importance of sulfur and nitrogen compounds in the acidification of freshwater

    SciTech Connect

    Van Miegroet, H.

    1992-08-01

    The acid-base chemistry of streams and lakes is regulated by the amount and composition of atmospheric deposition and by biogeochemical processes in the catchment and within streams and lakes. In this paper the influence of nitrogen (N) and sulfur (S) compounds will be discussed (a) because they are major constituents of atmospheric deposition that have recently become the focus of critical loads assessments in Europe and North America, and (b) because they are essential nutrients for most biota and cycle naturally through terrestrial and aquatic ecosystems. In order to evaluate the relative impact of atmospheric inputs on freshwater acidity, it is necessary to clearly define ``acidification`` and to understand; the mechanisms of change caused or mediated by natural and anthropogenic processes.

  18. The relative importance of sulfur and nitrogen compounds in the acidification of freshwater

    SciTech Connect

    Van Miegroet, H.

    1992-01-01

    The acid-base chemistry of streams and lakes is regulated by the amount and composition of atmospheric deposition and by biogeochemical processes in the catchment and within streams and lakes. In this paper the influence of nitrogen (N) and sulfur (S) compounds will be discussed (a) because they are major constituents of atmospheric deposition that have recently become the focus of critical loads assessments in Europe and North America, and (b) because they are essential nutrients for most biota and cycle naturally through terrestrial and aquatic ecosystems. In order to evaluate the relative impact of atmospheric inputs on freshwater acidity, it is necessary to clearly define acidification'' and to understand; the mechanisms of change caused or mediated by natural and anthropogenic processes.

  19. Concentration and dry deposition of atmospheric sulfur and nitrogen compounds in Hungary

    NASA Astrophysics Data System (ADS)

    Mészáros, E.; Horváth, L.

    The level of regional air pollution is regularly monitored at three stations in Hungary. The comparison of regional concentrations of SO 2 and NO 2 to those measured in Budapest shows that urban level concentration of SO 2 is ten times higher than the value for background conditions. The corresponding figure for NO 2 is five. An increase eastwards across the country can be observed for NO 2 and SO 2, while particulate sulphate, nitrate and ammonium have practically identical concentrations. The concentration of gaseous ammonia has a summer maximum, while the annual variation of particulate ammonium suggests a winter maximum. The ratio of the level of nitric acid to aerosol nitrate is higher than unity in summer, while in winter it is less than 1. The dry deposition of sulfur and oxidized nitrogen compounds is comparable to their wet deposition. However, in the case of NHx ( x = 3 or 4) the wet deposition exceeds the dry deposition by an order of magnitude.

  20. PTR-MS measurement of partition coefficients of reduced volatile sulfur compounds in liquids from biotrickling filters.

    PubMed

    Liu, Dezhao; Feilberg, Anders; Nielsen, Anders Michael; Adamsen, Anders Peter S

    2013-01-01

    Biological air filtration for reduction of emissions of volatile sulfur compounds (e.g., hydrogen sulfide, methanethiol and dimethyl sulfide) from livestock production facilities is challenged by poor partitioning of these compounds into the aqueous biofilm or filter trickling water. In this study, Henry's law constants of reduced volatile sulfur compounds were measured for deionized water, biotrickling filter liquids (from the first and second stages of a two-stage biotrickling filter), and NaCl solutions by a dynamic method using Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) at a temperature range of 3-45°C. NaCl solutions were used to estimate salting-out constants up to an ionic strength of 0.7 M in order to evaluate the effect of ionic strength on partitioning between air and biofilter liquids. Thermodynamic parameters (enthalpy and entropy of phase exchange) were obtained from the measured partition coefficients as a function of temperature. The results show that the partition coefficients of organic sulfur compounds in the biotrickling filter liquids were generally very close to the corresponding partition coefficients in deionized water. Based on the estimated ionic strength of biofilter liquids, it is assessed that salting-out effects are of no importance for these compounds. For H(2)S, a higher enthalpy of air-liquid partitioning was observed for 2nd stage filter liquid, but not for 1st stage filter liquid. In general, the results show that co-solute effects for sulfur compounds can be neglected in numerical biofilter models and that the uptake of volatile sulfur compounds in biotrickling filter liquids cannot be increased by decreasing ionic strength. PMID:22960062

  1. Sodium sulfur cell

    SciTech Connect

    Mitoff, S.P.; Roth, W.L.

    1980-09-02

    In a sodium sulfur cell, including a beta-alumina separator between the sodium and sulfur compartments, high surface area gettering means, e.g., beta-alumina or beta''-alumina, for potassium and alkali earth metal ion impurities are included in the sodium to protect the separator. The gettering means is disposed in the sodium container in the form of particles or a continous porous shell or porous solid plug adjacent to the separator.

  2. CATALYTIC OXIDATION OF TOTAL REDUCED SULFUR COMPOUNDS FROM PULP AND PAPER INDUSTRIES WITH OZONE AS AN OXIDANT

    EPA Science Inventory

    Pulp and paper industry generates more than 144 million lb of VOCs per year including a range of reduced sulfur compounds (TRS) such as dimethyl sulfide (DMS), dimethyl disulfide (DMDS), methane thiol (MT) and H2S that are odorous, toxic and contribute to smog formation. Thermal ...

  3. Separation of sulfur isotopes

    DOEpatents

    DeWitt, Robert; Jepson, Bernhart E.; Schwind, Roger A.

    1976-06-22

    Sulfur isotopes are continuously separated and enriched using a closed loop reflux system wherein sulfur dioxide (SO.sub.2) is reacted with sodium hydroxide (NaOH) or the like to form sodium hydrogen sulfite (NaHSO.sub.3). Heavier sulfur isotopes are preferentially attracted to the NaHSO.sub.3, and subsequently reacted with sulfuric acid (H.sub.2 SO.sub.4) forming sodium hydrogen sulfate (NaHSO.sub.4) and SO.sub.2 gas which contains increased concentrations of the heavier sulfur isotopes. This heavy isotope enriched SO.sub.2 gas is subsequently separated and the NaHSO.sub.4 is reacted with NaOH to form sodium sulfate (Na.sub.2 SO.sub.4) which is subsequently decomposed in an electrodialysis unit to form the NaOH and H.sub.2 SO.sub.4 components which are used in the aforesaid reactions thereby effecting sulfur isotope separation and enrichment without objectionable loss of feed materials.

  4. The characterization of sulfur incorporation in GaAs (1-x)S x compound by infra-red spectroscopy

    NASA Astrophysics Data System (ADS)

    Lalande, F.; Carchano, H.; Pourcin, J.

    1993-04-01

    This study focused on the incorporation of sulfur in a GaAs (1-x)S x semiconductor lattice. The experimental infrared absorption spectra of this polycrystalline compound exhibited a number of peaks with frequency shifts that varied to a greater or lesser degree according to the molar fraction x. Experimental results are fitted by an empirical force field based on a theoretical model for the cell units [20]. The sulfur atoms are assumed to be incorporated in the substance taking the place of arsenic atoms. If the S-S second-neighbor force constant has a high value, there is a covalent bond, thus explaining the non-ionic effect of sulfur in electrical majority carrier measurement.

  5. Geochemical and sulfur isotope signatures of microbial activity in acidic and sulfuric hot springs, northern Taiwan

    NASA Astrophysics Data System (ADS)

    Wang, P.; Chen, K.; Cheng, T.; Hsieh, H.; Lin, L.

    2009-12-01

    Acidic and sulfuric hot springs are natural habitats for thermophilic sulfur-utilizing microorganisms. Integration of bioenergetic evaluation, molecular analysis and stable isotopic signatures may be able to exhibit a full view of microbial activity in such an extreme environment. Widely distributed hot springs hosted by the Tatung volcano group in northern Taiwan provide a chance to evaluate the interplay between geochemical variation and microbial metabolism especially for sulfur. Several hot spring ponds varying in sizes and geochemical characteristics were studied to reveal the possible control of fluid compositions on microbial metabolisms, and vice versa. Sulfate, sulfide, elemental sulfur and dissolved organic carbon were available in spring water and sediments in the ponds. Dominant microbial metabolisms inferred from the bioenergetic evaluation were aerobic oxidations of various reduced compounds, including elemental sulfur, pyrite, ferrous iron and organic carbon. Sulfate and sulfur reductions were thermodynamically favorable but provided less energy flux, while sulfur disproportionation was thermodynamically incapable. The analyses of 16S rRNA genes extracted from the spring water and sediments indicated that aerobic oxidation of sulfur, hydrogen or organic carbon and anaerobic elemental sulfur reduction were possible metabolisms. Since the major portion of 16S rRNA sequences were affiliated with unclassified environmental sequences, their potential metabolisms remained obscure. Sulfur isotopic compositions of dissolved sulfate, pyrite and elemental sulfur exhibited significant variations among the different hot spring ponds. Apparently, the microbial effects on the sulfur isotopic signatures were various. A disproportionation reaction of volcanic gas was required to account for high sulfur isotope difference between sulfate and reduced sulfur in the large hot ponds. In contrary, abiotic or microbial oxidation of reduced sulfur might be dominant in the small ponds, where only small sulfur isotopic fractionation occurred among the sulfur species. Both sulfate and elemental sulfur reduction could not be recognized as the sulfide in all ponds were not the most depleted in S-34.

  6. Emission of volatile sulfur compounds during composting of municipal solid waste (MSW)

    SciTech Connect

    Zhang, Hongyu; Schuchardt, Frank; Li, Guoxue; Yang, Jinbing; Yang, Qingyuan

    2013-04-15

    Highlights: ► We compare the volatile sulfur compounds (VSCs) emissions during three types of municipal solid wastes (MSWs) composting. ► The VSCs released from the kitchen waste composting was significantly higher than that from 15–80 mm fraction of MSW. ► Among the five VSCs, H{sub 2}S was the most abundant compound with 39.0–43.0% of total VSCs released. ► Addition of 20% cornstalks could significantly reduce the VSCs emissions during kitchen waste composting. - Abstract: Volatile sulfur compounds (VSCs) are the main source for malodor from composting plants. In this study, the VSCs generated from composting of 15–80 mm municipal solid waste (T0), kitchen waste (T1) and kitchen waste mixed dry cornstalks (T2) were measured in 60 L reactors with forced aeration for a period of 30 days. The VSCs detected in all treatments were hydrogen sulfide (H{sub 2}S), methyl mercaptan (MM), dimethyl sulfide (DMS), carbon bisulfide (CS{sub 2}) and dimethyl disulfide (DMDS). Over 90% of the VSCs emissions occurred during the first 15 days, and reached their peak values at days 4–7. The emission profiles of five VSCs species were significantly correlated with internal materials temperature and outlet O{sub 2} concentration (p < 0.05). Total emissions of the VSCs were 216.1, 379.3 and 126.0 mg kg{sup −1} (dry matter) for T0, T1 and T2, respectively. Among the five VSCs, H{sub 2}S was the most abundant compound with 39.0–43.0% of total VSCs released. Composting of kitchen waste from separate collection posed a negative influence on the VSC and leachate production because of its high moisture content. An addition of dry cornstalks at a mixing ratio of 4:1 (wet weight) could significantly reduce the VSCs emissions and avoid leachate. Compared to pure kitchen waste, VSCs were reduced 66.8%.

  7. Bacterial ethane formation from reduced, ethylated sulfur compounds in anoxic sediments

    USGS Publications Warehouse

    Oremland, R.S.; Whiticar, Michael J.; Strohmaier, F.E.; Kiene, R.P.

    1988-01-01

    Trace levels of ethane were produced biologically in anoxic sediment slurries from five chemically different aquatic environments. Gases from these locations displayed biogenic characteristics, having 12C-enriched values of ??13CH4 (-62 to -86%.), ??13C2H6 (-35 to -55%.) and high ratios (720 to 140,000) of CH4 [C2H6 + C3H8]. Endogenous production of ethane by slurries was inhibited by autoclaving or by addition of the inhibitor of methanogenic bacteria, 2-bromoethanesulfonic acid (BES). Ethane formation was stimulated markedly by ethanethiol (ESH), and, to a lesser extent, by diethylsulfide (DES). Formation of methane and ethane in ESH- or DES-amended slurries was blocked by BES. Experiments showed that ethionine (or an analogous compound) could be a precursor of ESH. Ethylamine or ethanol additions to slurries caused only a minor stimulation of ethane formation. Similarly, propanethiol additions resulted in only a minor enhancement of propane formation. Cell suspensions of a methyltrophic methanogen produced traces of ethane when incubated in the presence of DES, although the organism did not grow on this compound. These results indicate that methanogenic bacteria produce ethane from the traces of ethylated sulfur compounds present in recent sediments. Preliminary estimates of stable carbon isotope fractionation associated with sediment methane formation from dimethylsulfide was about 40%., while ethane formation from DES and ESH was only 4. 6 and 6.5%., respectively. ?? 1988.

  8. Measurement of air-surface exchange of speciated nitrogen and sulfur compounds using a modified MARGA 2S: Assessment and control of data quality

    EPA Science Inventory

    Improved measurement methods are needed to characterize dry deposition of sulfur and nitrogen compounds to assess ecosystem exposure to nutrients and acidifying compounds and to develop atmospheric deposition budgets in support of critical loads assessments. The purpose of this ...

  9. Measurement of air-surface exchange of speciated nitrogen and sulfur compounds using a modified MARGA 2S: ? Concentrations and fluxes above a grass field

    EPA Science Inventory

    Improved measurement methods are needed to characterize dry deposition of sulfur and nitrogen compounds to assess ecosystem exposure to nutrients and acidifying compounds and to develop atmospheric deposition budgets in support of critical loads assessments. The purpose of this s...

  10. Sulfur monochloride in organic synthesis

    NASA Astrophysics Data System (ADS)

    Konstantinova, L. S.; Rakitin, O. A.

    2014-03-01

    The data on the reactivity of sulfur monochloride published in the past 15 years have been reviewed and systematized. The review focuses on the synthesis of acyclic and heterocyclic compounds with the use of S2Cl2. The bibliography includes 154 references.

  11. Determination of reduced sulfur compounds in air samples for the monitoring of malodor caused by landfills.

    PubMed

    Borrás, Esther; Tortajada-Genaro, Luis Antonio; Muñoz, Amalia

    2016-02-01

    A reliable method for determining malodorous reduced sulfur compounds (RSC) in atmospheric samples has been developed. The method uses an activated coconut solid-phase sorbent for active sampling, hexane as desorption solvent, and gas chromatography-mass spectrometry (GC-MS) technique for specific and sensitive separation-detection. The compounds analyzed were hydrogen sulfide, ethyl mercaptan, dimethyl sulfide, carbon disulfide, butyl mercaptan and dimethyl disulfide. Recovery efficiency varied between 75% and 97% and no detectable losses were observed during storage at -20°C. Satisfactory analytical parameters were reported, such as good linearity (r(2)>0.98), low detection limits (0.6-59 pg m(-3)), adequate repeatability (9%) and reproducibility (17%), and fast GC-MS analysis (<6.5 min). The accurate determination of RSCs, free of interferences from atmospheric components, such as ozone or water was demonstrated. The method has been applied to analyze the composition of environmental air close to three landfills processing urban and industrial solid wastes. The results indicated that hydrogen sulfide and ethyl mercaptan were the main molecules responsible of malodor phenomenon in the study areas. PMID:26653474

  12. Emission of volatile sulfur compounds during composting of municipal solid waste (MSW).

    PubMed

    Zhang, Hongyu; Schuchardt, Frank; Li, Guoxue; Yang, Jinbing; Yang, Qingyuan

    2013-04-01

    Volatile sulfur compounds (VSCs) are the main source for malodor from composting plants. In this study, the VSCs generated from composting of 15-80 mm municipal solid waste (T0), kitchen waste (T1) and kitchen waste mixed dry cornstalks (T2) were measured in 60 L reactors with forced aeration for a period of 30 days. The VSCs detected in all treatments were hydrogen sulfide (H2S), methyl mercaptan (MM), dimethyl sulfide (DMS), carbon bisulfide (CS2) and dimethyl disulfide (DMDS). Over 90% of the VSCs emissions occurred during the first 15 days, and reached their peak values at days 4-7. The emission profiles of five VSCs species were significantly correlated with internal materials temperature and outlet O2 concentration (p<0.05). Total emissions of the VSCs were 216.1, 379.3 and 126.0 mg kg(-1) (dry matter) for T0, T1 and T2, respectively. Among the five VSCs, H2S was the most abundant compound with 39.0-43.0% of total VSCs released. Composting of kitchen waste from separate collection posed a negative influence on the VSC and leachate production because of its high moisture content. An addition of dry cornstalks at a mixing ratio of 4:1 (wet weight) could significantly reduce the VSCs emissions and avoid leachate. Compared to pure kitchen waste, VSCs were reduced 66.8%. PMID:23312132

  13. The south Karelia air pollution study: Effects of low-level expsoure to malodorous sulfur compounds on symptoms

    SciTech Connect

    Partti-Pellinen, K.; Marttila, O.; Vilkka, V.; Jaakkola, J.J. |

    1996-07-01

    Exposure to very low levels of ambient-air malodorous sulfur compounds and their effect on eye irritation, respiratory-tract symptoms, and central nervous system symptoms in adults were assessed. A cross-sectional self-administered questionnaire (response rate = 77%) was distributed during March and April 1992 to adults (n = 336) who lived in a neighborhood that contained a pulp mill and in a nonpolluted reference community (n = 380). In the exposed community, the measured annual mean concentrations of total reduced sulfur compounds and sulfur dioxide measured in two stations were 2 to 3 {mu}g/m{sup 3} and 1 {mu}g/m{sup 3}, respectively. In the reference community, the annual mean concentration of sulfur dioxide was 1 {mu}g/m{sup 3}. The residents of the community near the pulp mill reported an excess of cough, respiratory infections, and headache during the previous 4 wk, as well as during the preceding 12 mo. The relative risk for headache was increased significantly in the exposed community, compared with the reference area: the adjusted odds ratio (aOR) was 1.83 (95% confidence interval [95% Cl] = 1.06-3.15) during the previous 4 wk and 1.70 (95% Cl = 1.05-2.73) during the preceding 12 mo. The relative risk for cough was also increased during the preceding 12 mo (aOR = 1.64, 95% Cl = 1.01-2.64). These results indicated that adverse health effects of malodorous sulfur compounds occur at lower concentrations than reported previously. 25 refs., 3 tabs.

  14. Thermodynamic analysis of the process of formation of sulfur compounds in oxygen gasification of coal

    SciTech Connect

    G.Ya. Gerasimov; T.M. Bogacheva

    2001-05-15

    A thermodynamic approach to the description of the behavior of the system fuel-oxidizer in oxygen gasification of coal is used to reveal the main mechanisms of the process of capture of sulfur by the mineral part of the coal and to determine the fundamental possibility of the process for coals from different coal fields.

  15. REGIONAL AIR POLLUTION STUDY: SULFUR COMPOUNDS AND PARTICULATE SIZE DISTRIBUTION INVENTORY

    EPA Science Inventory

    In conjunction with the Regional Air Pollution Study being conducted in the St. Louis Air Quality Control Region (AQCR), a methodology for estimating the amount of sulfur trioxide (SO3) emitted by combustion sources was developed. It is based on SO2/SO3 ratios determined both exp...

  16. Sulfur activation in Hiroshima

    SciTech Connect

    Kerr, G.D.; Pace, J.V. III

    1987-01-01

    In 1979, we attempted to establish the validity of source terms for the Hiroshima and Nagasaki bombs using experimental data on sulfur activation. Close agreement was observed between measured and calculated values for test firings of Nagasaki-type bombs. The calculated values were based on source terms developed by W.E. Preeg at the Los Alamos National Laboratory (LANL). A discrepancy was found, however, when we compared calculated values for the two bombs because a 1956 report by R.R. Wilson stated that sulfur acitvation by fast neutrons in Hiroshima was approximately three times greater than in Nagasaki. Our calculations based on Preeg's source-term data predicted about equal sulfur activation in the two cities.

  17. Sodium sulfur battery seal

    DOEpatents

    Mikkor, Mati

    1981-01-01

    This disclosure is directed to an improvement in a sodium sulfur battery construction in which a seal between various battery compartments is made by a structure in which a soft metal seal member is held in a sealing position by holding structure. A pressure applying structure is used to apply pressure on the soft metal seal member when it is being held in sealing relationship to a surface of a container member of the sodium sulfur battery by the holding structure. The improvement comprises including a thin, well-adhered, soft metal layer on the surface of the container member of the sodium sulfur battery to which the soft metal seal member is to be bonded.

  18. Interstellar sulfur chemistry

    NASA Technical Reports Server (NTRS)

    Prasad, S. S.; Huntress, W. T., Jr.

    1980-01-01

    The results of a chemical model of SO, CS, and OCS chemistry in dense clouds are summarized. The results are obtained from a theoretical study of sulfur chemistry in dense interstellar clouds using a large-scale time-dependent model of gas-phase chemistry. Among the results are the following: (1) owing to activation energy, the reaction of CS with O atoms is efficient as a loss mechanism of CS during the early phases of cloud evolution or in hot and oxygen-rich sources such as the KL nebula; (2) if sulfur is not abnormally depleted in dense clouds, then the observed abundances of SO, SO2, H2S, CS, OCS, H2CS, and SiS indicate that sulfur is mostly atomic in dense clouds; and (3) OCS is stable against reactions with neutral atoms and radicals in dense clouds.

  19. Sulfur recovery technology

    SciTech Connect

    Goar, B.G.

    1986-01-01

    The production of sour natural gas and the refining of higher sulfur content crude oils is increasing in the world today. The need to recover sulfur from hydrogen sulfide produced from such sources is also on the rise. In today's society there is an increased concern about the potential threat of air pollution to the well-being of mankind. Therefore, the various technologies for removing and converting hydrogen sulfide to elemental sulfur are gaining increased importance in industry. The Claus process was invented by an English scientist named Carl Friedrich Claus and a patent was issued to him in late 1883. In 1938, a German company called I.G. Fabenindustrie A.G. made a significant modification to the original Claus process; and thus, the Modified Claus Process was born. Today the majority of sour gas that is processed in the United States and throughout the world, and the majority of sour crude oil refined in the world produces hydrogen sulfide which is eventually converted to elemental sulfur by the Claus process. Other technologies have emerged down through the years; but, none have ever come close to making the impact on industry that the Claus process has achieved. It is estimated that some 90 to 95% of recovered sulfur in the world today is produced by the Claus process. There are over 380 Claus plants (specific locations) in operation throughout the world. It is estimated that when these plants are in full production, something like 60,000 long tons per day (LTPD) of sulfur can be produced from these plants.

  20. Catalyst for the reduction of sulfur dioxide to elemental sulfur

    DOEpatents

    Jin, Yun; Yu, Qiquan; Chang, Shih-Ger

    1996-01-01

    The inventive catalysts allow for the reduction of sulfur dioxide to elemental sulfur in smokestack scrubber environments. The catalysts have a very high sulfur yield of over 90% and space velocity of 10,000 h.sup.-1. They also have the capacity to convert waste gases generated during the initial conversion into elemental sulfur. The catalysts have inexpensive components, and are inexpensive to produce. The net impact of the invention is to make this technology practically available to industrial applications.

  1. Process for removing sulfur from coal

    DOEpatents

    Aida, Tetsuo; Squires, Thomas G.; Venier, Clifford G.

    1985-02-05

    A process for the removal of divalent organic and inorganic sulfur compounds from coal and other carbonaceous material. A slurry of pulverized carbonaceous material is contacted with an electrophilic oxidant which selectively oxidizes the divalent organic and inorganic compounds to trivalent and tetravalent compounds. The carbonaceous material is then contacted with a molten caustic which dissolves the oxidized sulfur compounds away from the hydrocarbon matrix.

  2. Process for removing sulfur from coal

    DOEpatents

    Aida, T.; Squires, T.G.; Venier, C.G.

    1983-08-11

    A process is disclosed for the removal of divalent organic and inorganic sulfur compounds from coal and other carbonaceous material. A slurry of pulverized carbonaceous material is contacted with an electrophilic oxidant which selectively oxidizes the divalent organic and inorganic compounds to trivalent and tetravalent compounds. The carbonaceous material is then contacted with a molten caustic which dissolves the oxidized sulfur compounds away from the hydrocarbon matrix.

  3. Assessment of reduced sulfur compounds in ambient air as malodor components in an urban area

    NASA Astrophysics Data System (ADS)

    Susaya, Janice; Kim, Ki-Hyun; Phan, Nhu-Thuc; Kim, Jo-Chun

    2011-07-01

    Long-term monitoring of reduced sulfur compounds (RSCs: hydrogen sulfide (H 2S), methanethiol (CH 3SH), dimethyl sulfide (DMS), and dimethyl disulfide (DMDS)) in ambient air was made using an on-line GC system at an odor monitoring station in the city of Ansan, South Korea (August 2005-December 2007). The results were examined to assess the status of RSC pollution, its relative contribution to malodor, and the controlling factors of its occurrence. H 2S (mean of 0.27 ppb) was eminent in terms of both magnitude and occurrence frequency, while others were not with mean values of 0.11 (DMDS), 0.10 (DMS), and 0.07 ppb (CH 3SH). Unlike others, the temporal trends of H 2S were best represented by the combined effects of its source processes and meteorological conditions. The results of correlation analysis indicate strong correlations between RSCs and water-related parameters (e.g., rainfall, dew point, and relative humidity). The role of RSCs as malodor component appears to be pronounced during nighttime, especially in summer. If the relative contribution of RSCs to malodor is assessed by means of the sum of odor intensity (SOI), its impact is relatively low, with an SOI value of 1.22 (weak odor strength). Consequently, a more deliberate approach may be needed to effectively assess odor occurrence patterns in ambient air.

  4. Computational Studies of CO2 Activation via Photochemical Reactions with Reduced Sulfur Compounds

    PubMed Central

    Baltrusaitis, Jonas; Patterson, Eric; Hatch, Courtney

    2012-01-01

    Reactions between CO2 and reduced sulfur compounds (RSC) - H2S and CH3SH - were investigated using ground and excited state density functional theory (DFT) and coupled cluster (CC) methods to explore possible RSC oxidation mechanisms and CO2 activation mechanisms in the atmospheric environment. Ground electronic state calculations at the CR-CC(2,3)/6-311+G(2df,2p)//CAM-B3LYP/6-311+G(2df,2p) level show proton transfer as a limiting step in the reduction of CO2 with activation energies of 49.64 and 47.70 kcal/mol, respectively, for H2S and CH3SH. On the first excited state surface, CR-EOMCC(2,3)/6-311+G(2df,2p)//CAM-B3LYP/6-311+G(2df,2p) calculations reveal that energies of <250 nm are needed to form H2S-CO2 and CH3SH-CO2 complexes allowing facile hydrogen atom transfer. Once excited, all reaction intermediates and transition states are downhill energetically showing either C-H or C-S bond formation in the excited state whereas only C-S bond formation was found in the ground state. Environmental implications of these data are discussed with a focus on tropospheric reactions between CO2 and RSC, as well as potential for carbon sequestration using photocatalysis. PMID:22920727

  5. Measurements of Volatile Organic Compounds and Gaseous Sulfuric Acid During the 2008 CAREBEIJING Campaign

    NASA Astrophysics Data System (ADS)

    Zhang, R.; Zheng, J.; Hu, M.; Zhu, T.

    2009-05-01

    Air quality in Beijing has been a hot topic recently, because Beijing hosted the 2008 summer Olympics. To combat the problem, China ordered numerous factories shut down or used only sporadically during the games to limit air pollution in the area. Another major step involved ordering about one-half of the city's 3.3 million vehicles off the road during the games, allowing only cars on roads with odd or even-numbered license plates on alternate days until the games were over. In addition, China has implemented new auto emission standards since March 2009 with regulations that are similar to those used throughout Europe. Our team at the Texas A&M participated in the 2008 CAREBEIJING campaign, with the objectives of studying the complex chemistry of the air in Beijing, looking at emission controls and their effectiveness, studying the surrounding air from other regions and how it can affect Beijing's air, and comparing all of our findings with air quality in other cities we have examined, such as Mexico City and Houston. In this talk, preliminary results of measurements of volatile organic compounds (VOCs) and gaseous sulfuric acid will be presented to discuss the trends of VOCs and new particle formation associated with the traffic control.

  6. Inhibition of microbial growth by ajoene, a sulfur-containing compound derived from garlic.

    PubMed

    Naganawa, R; Iwata, N; Ishikawa, K; Fukuda, H; Fujino, T; Suzuki, A

    1996-11-01

    Ajoene, a garlic-derived sulfur-containing compound that prevents platelet aggregation, exhibited broad-spectrum antimicrobial activity. Growth of gram-positive bacteria, such as Bacillus cereus, Bacillus subtilis, Mycobacterium smegmatis, and Streptomyces griseus, was inhibited at 5 micrograms of ajoene per ml. Staphylococcus aureus and Lactobacillus plantarum also were inhibited below 20 micrograms of ajoene per ml. For gram-negative bacteria, such as Escherichia coli, Klebsiella pneumoniae, and Xanthomonas maltophilia, MICs were between 100 and 160 micrograms/ml. Ajoene also inhibited yeast growth at concentrations below 20 micrograms/ml. The microbicidal effect of ajoene on growing cells was observed at slightly higher concentrations than the corresponding MICs. B. cereus and Saccharomyces cerevisiae were killed at 30 micrograms of ajoene per ml after 24 h of cultivation when cultivation was started at 10(5) cells per ml. However, the minimal microbicidal concentrations for resting cells were at 10 to 100 times higher concentrations than the corresponding MICs. The disulfide bond in ajoene appears to be necessary for the antimicrobial activity of ajoene, since reduction by cysteine, which reacts with disulfide bonds, abolished its antimicrobial activity. PMID:8900018

  7. Inhibition of microbial growth by ajoene, a sulfur-containing compound derived from garlic.

    PubMed Central

    Naganawa, R; Iwata, N; Ishikawa, K; Fukuda, H; Fujino, T; Suzuki, A

    1996-01-01

    Ajoene, a garlic-derived sulfur-containing compound that prevents platelet aggregation, exhibited broad-spectrum antimicrobial activity. Growth of gram-positive bacteria, such as Bacillus cereus, Bacillus subtilis, Mycobacterium smegmatis, and Streptomyces griseus, was inhibited at 5 micrograms of ajoene per ml. Staphylococcus aureus and Lactobacillus plantarum also were inhibited below 20 micrograms of ajoene per ml. For gram-negative bacteria, such as Escherichia coli, Klebsiella pneumoniae, and Xanthomonas maltophilia, MICs were between 100 and 160 micrograms/ml. Ajoene also inhibited yeast growth at concentrations below 20 micrograms/ml. The microbicidal effect of ajoene on growing cells was observed at slightly higher concentrations than the corresponding MICs. B. cereus and Saccharomyces cerevisiae were killed at 30 micrograms of ajoene per ml after 24 h of cultivation when cultivation was started at 10(5) cells per ml. However, the minimal microbicidal concentrations for resting cells were at 10 to 100 times higher concentrations than the corresponding MICs. The disulfide bond in ajoene appears to be necessary for the antimicrobial activity of ajoene, since reduction by cysteine, which reacts with disulfide bonds, abolished its antimicrobial activity. PMID:8900018

  8. Origins of sulfur compounds in the atmosphere of a zone of high productivity (Gulf of Guinea)

    SciTech Connect

    Delmas, R.; Servant, J.

    1982-12-20

    Recent observations have suggested substantial emission of sulfur compounds by oceanic water which could explain the presence of SO/sub 2/ and SO/sup +//sub 4/ in the air above these waters. The emission is thought to increase with the productivity of the oceanic zones. This point is discussed in relation to the Gulf of Guinea, a zone of high productivity. During the first two campaigns between Dakar, Abidjan, and the Gulf of Guinea SO/sup +//sub 4/ concentrations were measured in the air. Between Abidjan and the Gulf of Guinea the atmospheric SO= /sub 4/ concentrations decreased from 800 to 400 ng m/sup -3/. During the third campaign, between Abidjan and the South Equatorial Current (latitude 1/sup 0/S), the H/sub 2/S and SO/sub 2/ concentrations were measured. The mean H/sub 2/S concentration was 20 ng m/sup -3/, and that of SO/sub 2/ varied between 120 and under 50 ng m/sup -3/. The origins of SO/sub 2/ and SO/sup +//sub 4/ in the air of this area are discussed through the daily variations of the H/sub 2/S content of the air and a contribution from the forested zones of West Africa.

  9. Production and Fate of Methylated Sulfur Compounds from Methionine and Dimethylsulfoniopropionate in Anoxic Salt Marsh Sediments †

    PubMed Central

    Kiene, Ronald P.; Visscher, Pieter T.

    1987-01-01

    Anoxic salt marsh sediments were amended with dl-methionine and dimethylsulfoniopropionate (DMSP). Microbial metabolism of methionine yielded methane thiol (MSH) as the major volatile organosulfur product, with the formation of lesser amounts of dimethylsulfide (DMS). Biological transformation of DMSP resulted in the rapid release of DMS and only small amounts of MSH. Experiments with microbial inhibitors indicated that production of MSH from methionine was carried out by procaryotic organisms, probably sulfate-reducing bacteria. Methane-producing bacteria did not metabolize methionine. The involvement of specific groups of organisms in DMSP hydrolysis could not be determined with the inhibitors used, because DMSP was hydrolyzed in all samples except those which were autoclaved. Unamended sediment slurries, prepared from Spartina alterniflora sediments, contained significant (1 to 10 μM) concentrations of DMS. Endogenous methylated sulfur compounds and those produced from added methionine and DMSP were consumed by sediment microbes. Both sulfate-reducing and methane-producing bacteria were involved in DMS and MSH consumption. Methanogenesis was stimulated by the volatile organosulfur compounds released from methionine and DMSP. However, apparent competition for these compounds exists between methanogens and sulfate reducers. At low (1 μM) concentrations of methionine, the terminal S-methyl group was metabolized almost exclusively to CO2 and only small amounts of CH4. At higher (>100 μM) concentrations of methionine, the proportion of the methyl-sulfur group converted to CH4 increased. The results of this study demonstrate that methionine and DMSP are potential precursors of methylated sulfur compounds in anoxic sediments and that the microbial community is capable of metabolizing volatile methylated sulfur compounds. PMID:16347461

  10. Multi-functional sorbents for the simultaneous removal of sulfur and lead compounds from hot flue gases.

    PubMed

    Zhao, Yi; Lin, Wen-Chiang

    2003-10-01

    A multi-functional sorbent is developed for the simultaneous removal of PbCl(2) vapor and sulfur dioxide from the combustion gases. The sorbent is tested in a bench-scale reactor at the temperature of 700 degrees C, using simulated flue gas (SFG) containing controlled amounts of PbCl(2) and SO(2) compounds. The removal characteristics of PbCl(2) and SO(2), individually and in combination, are investigated. The results show that the mechanism of capture by the sorbent is not a simple physical adsorption process but seems to involve a chemical reaction between the Ca-based sorbent and the contaminants from the simulated flue gas. The porous product layer in the case of individual SO(2) sorption is in a molten state at the reaction temperature. In contrast, the combined sorption of lead and sulfur compounds generates a flower-shaped polycrystalline product layer. PMID:14568696

  11. Sulfur Dioxide Pollution Monitor.

    ERIC Educational Resources Information Center

    National Bureau of Standards (DOC), Washington, DC.

    The sulfur dioxide pollution monitor described in this document is a government-owed invention that is available for licensing. The background of the invention is outlined, and drawings of the monitor together with a detailed description of its function are provided. A sample stream of air, smokestack gas or the like is flowed through a…

  12. COAL SULFUR MEASUREMENTS

    EPA Science Inventory

    The report describes a new technique for sulfur forms analysis based on low-temperature oxygen plasma ashing. The technique involves analyzing the low-temperature plasma ash by modified ASTM techniques after selectively removing the organic material. The procedure has been tested...

  13. Meteoritic Sulfur Isotopic Analysis

    NASA Technical Reports Server (NTRS)

    Thiemens, Mark H.

    1996-01-01

    Funds were requested to continue our program in meteoritic sulfur isotopic analysis. We have recently detected a potential nucleosynthetic sulfur isotopic anomaly. We will search for potential carriers. The documentation of bulk systematics and the possible relation to nebular chemistry and oxygen isotopes will be explored. Analytical techniques for delta(sup 33), delta(sup 34)S, delta(sup 36)S isotopic analysis were improved. Analysis of sub milligram samples is now possible. A possible relation between sulfur isotopes and oxygen was detected, with similar group systematics noted, particularly in the case of aubrites, ureilites and entstatite chondrites. A possible nucleosynthetic excess S-33 has been noted in bulk ureilites and an oldhamite separate from Norton County. High energy proton (approximately 1 GeV) bombardments of iron foils were done to experimentally determine S-33, S-36 spallogenic yields for quantitation of isotopic measurements in iron meteorites. Techniques for measurement of mineral separates were perfected and an analysis program initiated. The systematic behavior of bulk sulfur isotopes will continue to be explored.

  14. Sulfur Dioxide Pollution Monitor.

    ERIC Educational Resources Information Center

    National Bureau of Standards (DOC), Washington, DC.

    The sulfur dioxide pollution monitor described in this document is a government-owed invention that is available for licensing. The background of the invention is outlined, and drawings of the monitor together with a detailed description of its function are provided. A sample stream of air, smokestack gas or the like is flowed through a

  15. Sodium sulfur battery seal

    DOEpatents

    Topouzian, Armenag

    1980-01-01

    This invention is directed to a seal for a sodium sulfur battery in which a flexible diaphragm sealing elements respectively engage opposite sides of a ceramic component of the battery which separates an anode compartment from a cathode compartment of the battery.

  16. Positive electrode for galvanic cells prepared by anodization of CrO 3-graphite intercalation compounds in aqueous sulfuric acid

    NASA Astrophysics Data System (ADS)

    Skowroński, J. M.; Jurewicz, K.

    Cathode materials have been prepared in 12 M H 2SO 4 by electrochemical oxidation of CrO 3-graphite intercalation compounds (CrO 3-GICs). Striking effects appearing on cyclic potentiodynamic curves of CrO 3-GICs because of intercalation of sulfuric acid are discussed in relation to the formation of the CrO 3-graphite oxide system. Charge/discharge characteristics of these cathodes are compared with those of graphite oxide prepared from pure graphite.

  17. SULFUR POLYMER ENCAPSULATION.

    SciTech Connect

    KALB, P.

    2001-08-22

    Sulfur polymer cement (SPC) is a thermoplastic polymer consisting of 95 wt% elemental sulfur and 5 wt% organic modifiers to enhance long-term durability. SPC was originally developed by the U.S. Bureau of Mines as an alternative to hydraulic cement for construction applications. Previous attempts to use elemental sulfur as a construction material in the chemical industry failed due to premature degradation. These failures were caused by the internal stresses that result from changes in crystalline structure upon cooling of the material. By reacting elemental sulfur with organic polymers, the Bureau of Mines developed a product that successfully suppresses the solid phase transition and significantly improves the stability of the product. SPC, originally named modified sulfur cement, is produced from readily available, inexpensive waste sulfur derived from desulfurization of both flue gases and petroleum. The commercial production of SPC is licensed in the United States by Martin Resources (Odessa, Texas) and is marketed under the trade name Chement 2000. It is sold in granular form and is relatively inexpensive ({approx}$0.10 to 0.12/lb). Application of SPC for the treatment of radioactive, hazardous, and mixed wastes was initially developed and patented by Brookhaven National Laboratory (BNL) in the mid-1980s (Kalb and Colombo, 1985; Colombo et al., 1997). The process was subsequently investigated by the Commission of the European Communities (Van Dalen and Rijpkema, 1989), Idaho National Engineering Laboratory (Darnell, 1991), and Oak Ridge National Laboratory (Mattus and Mattus, 1994). SPC has been used primarily in microencapsulation applications but can also be used for macroencapsulation of waste. SPC microencapsulation has been demonstrated to be an effective treatment for a wide variety of wastes, including incinerator hearth and fly ash; aqueous concentrates such as sulfates, borates, and chlorides; blowdown solutions; soils; and sludges. It is not recommended for treatment of wastes containing high concentrations of nitrates because of potentially dangerous reactions between sulfur, nitrate, and trace quantities of organics. Recently, the process has been adapted for the treatment of liquid elemental mercury and mercury contaminated soil and debris.

  18. Transformation of Sulfur Compounds by an Abundant Lineage of Marine Bacteria in the α-Subclass of the Class Proteobacteria

    PubMed Central

    González, José M.; Kiene, Ronald P.; Moran, Mary Ann

    1999-01-01

    Members of a group of marine bacteria that is numerically important in coastal seawater and sediments were characterized with respect to their ability to transform organic and inorganic sulfur compounds. Fifteen strains representing the Roseobacter group (a phylogenetic cluster of marine bacteria in the α-subclass of the class Proteobacteria) were isolated from seawater, primarily from the southeastern United States. Although more than one-half of the isolates were obtained without any selection for sulfur metabolism, all of the isolates were able to degrade the sulfur-containing osmolyte dimethyl sulfoniopropionate (DMSP) with production of dimethyl sulfide (DMS). Five isolates also degraded DMSP with production of methanethiol, indicating that both cleavage and demethylation pathways for DMSP occurred in the same organism, which is unusual. Five isolates were able to reduce dimethyl sulfoxide to DMS, and several isolates also degraded DMS and methanethiol. Sulfite oxygenase activity and methanesulfonic acid oxygenase activity were also present in some of the isolates. The ability to incorporate the reduced sulfur in DMSP and methanethiol into cellular material was studied with one of the isolates. A group-specific 16S rRNA probe indicated that the relative abundance of uncultured bacteria in the Roseobacter group increased in seawater enriched with DMSP or DMS. Because this group typically accounts for >10% of the 16S ribosomal DNA pool in coastal seawater and sediments of the southern United States, clues about its potential biogeochemical role are of particular interest. Studies of culturable representatives suggested that the group could mediate a number of steps in the cycling of both organic and inorganic forms of sulfur in marine environments. PMID:10473380

  19. Carbon nanostructures as catalytic support for chemiluminescence of sulfur compounds in a molecular emission cavity analysis system.

    PubMed

    Safavi, Afsaneh; Maleki, Norouz; Doroodmand, Mohammad Mahdi; Koleini, Mohammad Mehdi

    2009-06-30

    The effect of different substrates including stainless steel, activated carbon, single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), fullerenes (C60, C70, etc.) and SWCNTs doped with iron and palladium nanoparticles were compared for catalytic chemiluminescence reaction of sulfur compounds in a flame-containing cavity of molecular emission cavity analysis (MECA) system. Different forms of CNT substrates were fabricated using electric arc-discharge method. The blue emission of excited S2 was monitored using a CCD camera. The results demonstrate that, due to the high surface area, plenty of basal planes, high thermal conductivity, and high flexibility of the carbon nanostructure as appropriate support, carbon nanostructures play an important role in catalytic chemiluminescence emission of sulfur compounds in MECA. Moreover, the presence of metallic nanoparticles doped on carbon nanostructures enhances their catalytic effect. The results revealed that under similar conditions, SWCNTs/Pd doped nanoparticles, SWCNTs/Fe doped nanoparticles, SWCNTs, MWCNTs and fullerenes have the most catalytic effects on chemiluminescence of sulfur compounds, respectively. PMID:19463563

  20. Sulfur Chemistry in Bacterial Leaching of Pyrite

    PubMed Central

    Schippers, A.; Jozsa, P.; Sand, W.

    1996-01-01

    In the case of pyrite bioleaching by Leptospirillum ferrooxidans, an organism without sulfur-oxidizing capacity, besides the production of tetra- and pentathionate, a considerable accumulation of elemental sulfur occurred. A similar result was obtained for chemical oxidation assays with acidic, sterile iron(III) ion-containing solutions. In the case of Thiobacillus ferrooxidans, only slight amounts of elemental sulfur were detectable because of the organism's capacity to oxidize sulfur compounds. In the course of oxidative, chemical pyrite degradation under alkaline conditions, the accumulation of tetrathionate, trithionate, and thiosulfate occurred. The data indicate that thiosulfate, trithionate, tetrathionate, and disulfane-monosulfonic acid are key intermediate sulfur compounds in oxidative pyrite degradation. A novel (cyclic) leaching mechanism is proposed which basically is indirect. PMID:16535406

  1. Effect of green tea on volatile sulfur compounds in mouth air.

    PubMed

    Lodhia, Parth; Yaegaki, Ken; Khakbaznejad, Ali; Imai, Toshio; Sato, Tsutomu; Tanaka, Tomoko; Murata, Takatoshi; Kamoda, Takeshi

    2008-02-01

    Many food products are claimed to be effective in controlling halitosis. Halitosis is caused mainly by volatile sulfur compounds (VSCs) such as H(2)S and CH(3)SH produced in the oral cavity. Oral microorganisms degrade proteinaceous substrates to cysteine and methionine, which are then converted to VSCs. Most treatments for halitosis focus on controlling the number of microorganisms in the oral cavity. Since tea polyphenols have been shown to have antimicrobial and deodorant effects, we have investigated whether green tea powder reduces VSCs in mouth air, and compared its effectiveness with that of other foods which are claimed to control halitosis. Immediately after administering the products, green tea showed the largest reduction in concentration of both H(2)S and CH(3)SH gases, especially CH(3)SH which also demonstrated a better correlation with odor strength than H(2)S; however, no reduction was observed at 1, 2 and 3 h after administration. Chewing gum, mints and parsley-seed oil product did not reduce the concentration of VSCs in mouth air at any time. Toothpaste, mints and green tea strongly inhibited VSCs production in a saliva-putrefaction system, but chewing gum and parsley-seed oil product could not inhibit saliva putrefaction. Toothpaste and green tea also demonstrated strong deodorant activities in vitro, but no significant deodorant activity of mints, chewing gum or parsley-seed oil product were observed. We concluded that green tea was very effective in reducing oral malodor temporarily because of its disinfectant and deodorant activities, whereas other foods were not effective. PMID:18388413

  2. Reduced sulfur compounds in gas from construction and demolition debris landfills.

    PubMed

    Lee, Sue; Xu, Qiyong; Booth, Matthew; Townsend, Timothy G; Chadik, Paul; Bitton, Gabriel

    2006-01-01

    The biological conversion of sulfate from disposed gypsum drywall to hydrogen sulfide (H(2)S) in the anaerobic environment of a landfill results in odor problems and possible health concerns at many disposal facilities. To examine the extent and magnitude of such emissions, landfill gas samples from wells, soil vapor samples from the interface of the waste and cover soil, and ambient air samples, were collected from 10 construction and demolition (C&D) debris landfills in Florida and analyzed for H(2)S and other reduced sulfur compounds (RSC). H(2)S was detected in the well gas and soil vapor at all 10 sites. The concentrations in the ambient air above the surface of the landfill were much lower than those observed in the soil vapor, and no direct correlation was observed between the two sampling locations. Methyl mercaptan and carbonyl sulfide were the most frequently observed other RSC, though they occurred at smaller concentrations than H(2)S. This research confirmed the presence of H(2)S at C&D debris landfills. High concentrations of H(2)S may be a concern for employees working on the landfill site. These results indicate that workers should use proper personal protection at C&D debris landfills when involved in excavation, landfill gas collection, or confined spaces. The results indicate that H(2)S is sufficiently diluted in the atmosphere to not commonly pose acute health impacts for these landfill workers in normal working conditions. H(2)S concentrations were extremely variable with measurements occurring over a very large range (from less than 3 ppbv to 12,000 ppmv in the soil vapor and from less than 3 ppbv to 50 ppmv in ambient air). Possible reasons for the large intra- and inter-site variability observed include waste and soil heterogeneities, impact of weather conditions, and different site management practices. PMID:16403620

  3. Transporters in plant sulfur metabolism

    PubMed Central

    Gigolashvili, Tamara; Kopriva, Stanislav

    2014-01-01

    Sulfur is an essential nutrient, necessary for synthesis of many metabolites. The uptake of sulfate, primary and secondary assimilation, the biosynthesis, storage, and final utilization of sulfur (S) containing compounds requires a lot of movement between organs, cells, and organelles. Efficient transport systems of S-containing compounds across the internal barriers or the plasma membrane and organellar membranes are therefore required. Here, we review a current state of knowledge of the transport of a range of S-containing metabolites within and between the cells as well as of their long distance transport. An improved understanding of mechanisms and regulation of transport will facilitate successful engineering of the respective pathways, to improve the plant yield, biotic interaction and nutritional properties of crops. PMID:25250037

  4. Allyl isothiocyanate from mustard seed is effective in reducing the levels of volatile sulfur compounds responsible for intrinsic oral malodor.

    PubMed

    Tian, Minmin; Hanley, A Bryan; Dodds, Michael W J

    2013-06-01

    Oral malodor is a major social and psychological issue that affects general populations. Volatile sulfur compounds (VSCs), particularly hydrogen sulfide (H₂S) and methyl mercaptan (CH₃SH), are responsible for most oral malodor. The objectives for this study were to determine whether allyl isothiocyanate (AITC) at an organoleptically acceptable level can eliminate VSCs containing a free thiol moiety and further to elucidate the mechanism of action and reaction kinetics. The study revealed that gas chromatograph with a sulfur detector demonstrated a good linearity, high accuracy and sensitivity on analysis of VSCs. Zinc salts eliminate the headspace level of H₂S but not CH₃SH. AITC eliminates both H₂S and CH₃SH via a nucleophilic addition reaction. In addition, a chemical structure-activity relationship study revealed that the presence of unsaturated group on the side chain of the isothiocyanate accelerates the elimination of VSCs. PMID:23470258

  5. Determination of sulfur and nitrogen compounds during the processing of dry fermented sausages and their relation to amino acid generation.

    PubMed

    Corral, Sara; Leitner, Erich; Siegmund, Barbara; Flores, Mónica

    2016-01-01

    The identification of odor-active sulfur and nitrogen compounds formed during the processing of dry fermented sausages was the objective of this study. In order to elucidate their possible origin, free amino acids (FAAs) were also determined. The volatile compounds present in the dry sausages were extracted using solvent assisted flavor evaporation (SAFE) and monitored by one and two-dimensional gas chromatography with different detectors: mass spectrometry (MS), nitrogen phosphorous (NPD), flame photometric (FPD) detectors, as well as gas chromatography-olfactometry. A total of seventeen sulfur and nitrogen compounds were identified and quantified. Among them, 2-acetyl-1-pyrroline was the most potent odor active compound, followed by methional, ethylpyrazine and 2,3-dihydrothiophene characterized by toasted, cooked potato, and nutty notes. The degradation of FAAs, generated during processing, was related to the production of aroma compounds, such as methionine forming methional and benzothiazole while ornithine was the precursor compound for 2-acetyl-1-pyrroline and glycine for ethylpyrazine. PMID:26213023

  6. Sulfur plumes off Namibia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Sulfur plumes rising up from the bottom of the ocean floor produce colorful swirls in the waters off the coast of Namibia in southern Africa. The plumes come from the breakdown of marine plant matter by anaerobic bacteria that do not need oxygen to live. This image was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite on April 24, 2002 Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  7. Acidophilic sulfur disproportionation

    NASA Astrophysics Data System (ADS)

    Hardisty, Dalton S.; Olyphant, Greg A.; Bell, Jonathan B.; Johnson, Adam P.; Pratt, Lisa M.

    2013-07-01

    Bacterial disproportionation of elemental sulfur (S0) is a well-studied metabolism and is not previously reported to occur at pH values less than 4.5. In this study, a sediment core from an abandoned-coal-mine-waste deposit in Southwest Indiana revealed sulfur isotope fractionations between S0 and pyrite (Δ34Ses-py) of up to -35‰, inferred to indicate intense recycling of S0 via bacterial disproportionation and sulfide oxidation. Additionally, the chemistry of seasonally collected pore-water profiles were found to vary, with pore-water pH ranging from 2.2 to 3.8 and observed seasonal redox shifts expressed as abrupt transitions from Fe(III) to Fe(II) dominated conditions, often controlled by fluctuating water table depths. S0 is a common product during the oxidation of pyrite, a process known to generate acidic waters during weathering and production of acid mine drainage. The H2S product of S0 disproportionation, fractionated by up to -8.6‰, is rapidly oxidized to S0 near redox gradients via reaction with Fe(III) allowing for the accumulation of isotopically light S0 that can then become subject to further sulfur disproportionation. A mass-balance model for S0 incorporating pyrite oxidation, S0 disproportionation, and S0 oxidation readily explains the range of observed Δ34Ses-py and emphasizes the necessity of seasonally varying pyrite weathering and metabolic rates, as indicated by the pore water chemistry. The findings of this research suggest that S0 disproportionation is potentially a common microbial process at a pH < 4.5 and can create large sulfur isotope fractionations, even in the absence of sulfate reduction.

  8. New sulfur-containing corrosion inhibitor

    SciTech Connect

    Prince, P.

    2000-04-01

    No corrosion inhibitor available today is ideal in every way, but a new class of sulfur-containing compounds promises to address many field requirements. This article describes the performance characteristics of these compounds and discusses possible inhibition mechanisms. The emphasis in this work was on better understanding corrosion inhibition by sulfur-containing inhibitors under high shear-stress conditions, with special focus on localized (pitting) corrosion. The results indicate that the new sulfur-containing inhibitors (e.g., mercaptoalcohol [MA]) could be more effective in the field than currently available inhibitors.

  9. Advanced Sulfur Control Processing

    SciTech Connect

    Gangwal, S.K.; Portzer, J.W.; Turk, B.S.; Gupta, R.

    1996-12-31

    The primary objective of this project is to determine the feasibility of an alternate concept for the regeneration of high temperature desulfurization sorbents in which elemental sulfur, instead of SO{sub 2}, is produced. If successful, this concept will eliminate or alleviate problems caused by the highly exothermic nature of the regeneration reaction, the tendency for metal sulfate formation, and the need to treat the regeneration off-gas to prevent atmospheric SO{sub 2}, emissions. Iron and cerium-based sorbents were chosen on the basis of thermodynamic analysis to determine the feasibility of elemental sulfur production. The ability of both to remove H{sub 2}S during the sulfidation phase is less than that of zinc-based sorbents, and a two-stage desulfurization process will likely be required. Preliminary experimental work used electrobalance reactors to compare the relative rates of reaction of O{sub 2} and H{sub 2}O with FeS. More detailed studies of the regeneration of FeS as well as the sulfidation of CeO{sub 2} and regeneration of Ce{sub 2}O{sub 2}S are being carried out in a laboratory-scale fixed-bed reactor equipped with a unique analytical system which permits semi-continuous analysis of the distribution of elemental sulfur, H{sub 2}S, and SO{sub 2} in the reaction product gas.

  10. Sulfur oxides scrubbing process

    SciTech Connect

    Reeder, P.E.

    1986-07-15

    A process is described for removing sulfur oxides and solid particulates from a gaseous effluent. The steps of the process consist of: contacting within a venturi structure a gaseous effluent containing sulfur oxides with a liquid scrubbing mixture; passing the admixture of the gaseous effluent and liquid scrubbing mixture through a constricted passage of the venturi structure to increase the velocity thereof; separating the admixture into a liquid portion and a gas portion; delivering the gas portion of the separation step to a packed tower beneath the packed section thereof; contacting the gas portion with liquid scrubbing mixture in the packed section of the tower to form a gaseous overhead effluent substantially free of sulfur oxides and a bottoms liquid; combining the bottom liquid from the packed section of the tower with the liquid portion from the separating step to form a combined liquid bottoms; adjusting the pH of the combined liquid bottoms with a basic solution to form a liquid scrubbing mixture, the basic solution selected from the group consisting of alkali metal hydroxides, ammonium hydroxide, and ammonia; and dividing the liquid scrubbing mixture into a tower bottoms products, a first recycle stream providing the liquid scrubbing mixture to the first contacting step, and a second recycle stream providing the liquid scrubbing mixture to the second contacting step.

  11. Expression and functional roles of Bradyrhizobium japonicum genes involved in the utilization of inorganic and organic sulfur compounds in free-living and symbiotic conditions.

    PubMed

    Sugawara, Masayuki; Shah, Gopit R; Sadowsky, Michael J; Paliy, Oleg; Speck, Justin; Vail, Andrew W; Gyaneshwar, Prasad

    2011-04-01

    Strains of Bradyrhizobium spp. form nitrogen-fixing symbioses with many legumes, including soybean. Although inorganic sulfur is preferred by bacteria in laboratory conditions, sulfur in agricultural soil is mainly present as sulfonates and sulfur esters. Here, we show that Bradyrhizobium japonicum and B. elkanii strains were able to utilize sulfate, cysteine, sulfonates, and sulfur-ester compounds as sole sulfur sources for growth. Expression and functional analysis revealed that two sets of gene clusters (bll6449 to bll6455 or bll7007 to bll7011) are important for utilization of sulfonates sulfur source. The bll6451 or bll7010 genes are also expressed in the symbiotic nodules. However, B. japonicum mutants defective in either of the sulfonate utilization operons were not affected for symbiosis with soybean, indicating the functional redundancy or availability of other sulfur sources in planta. In accordance, B. japonicum bacteroids possessed significant sulfatase activity. These results indicate that strains of Bradyrhizobium spp. likely use organosulfur compounds for growth and survival in soils, as well as for legume nodulation and nitrogen fixation. PMID:21190435

  12. Antioxidant effects of sulfur-containing amino acids.

    PubMed

    Atmaca, Gulizar

    2004-10-31

    Sulfur is an essential element for the entire biological kingdom because of its incorporation into amino acids, proteins and other biomolecules. Sulfur atoms are also important in the iron-containing flavoenzymes. Unlike humans, plants can use inorganic sulfur to synthesize sulfur-containing amino acids. Therefore, plants are an important source of sulfur for humans. Sulfur-containing compounds are found in all body cells and are indispensable for life. Some of sulfur-containing antioxidant compounds are, cysteine, methionine, taurine, glutathione, lipoic acid, mercaptopropionylglycine, N-acetylcysteine, and the three major organosulfur compounds of garlic oil, diallylsulfide, diallyldisulfide and diallyltrisulfide. In a comparison of the structure-function relationship among these sulfur-containing antioxidant compounds, dihydrolipoic acid (the reduced form of LA) is the most effective antioxidant. Dihydrolipoic acid contains two sulfhydryl groups and can undergo further oxidation reaction to form lipoic acid. The antioxidative activities of sulfur-containing compounds follow a general trend, the more highly reduced forms are stronger antioxidants and the number of sulfur atoms determine, at least in part, their modulatory activites on the glutathione related antioxidant enzymes. In this article, the antioxidant effects and the antioxidative activities, of sulfur-containing amino acids, are reviewed. In addition, the general antioxidant effects and the structure-function relationship of some sulfur-containing compounds are also reviewed. PMID:15515186

  13. Preparation of organic sulfur adsorbent from coal for adsorption of dibenzothiophene-type compounds in diesel fuel

    SciTech Connect

    Cigdem Shalaby; Xiaoliang Ma; Anning Zhou; Chunshan Song

    2009-05-15

    High-performance organic sulfur adsorbents (OSA) have been prepared from coal by chemical activation for selective adsorption of the refractory sulfur compounds, such as 4-methyl dibenzothiophene and 4,6-dimethyldibenzothiophene, in diesel fuel. The performance of the prepared OSAs for adsorptive desulfurization (ADS) was evaluated in batch and flow adsorption systems at room temperature using a model diesel fuel. It was found that coal rank and preparation conditions, including activation agents (NaOH, KOH, and NaOH + KOH) and their ratio to coal, activation temperature, and time have significant impacts on the yield and ADS performance of the OSAs. The high-performance OSAs can be prepared from different ranks of coal by using NaOH + KOH as an activation agent with an activating-agent-to-coal ratio of 3.5. The yield of OSA increased in the order of lignite < high volatile bituminous coal < medium volatile bituminous coal < anthracite. The OSA-A, which was derived from an anthracite with the highest yield (68 wt %) by the activation at 650{sup o}C for 1 h, gave the best ADS performance among the OSAs from all coal samples tested. The sulfur adsorption capacity of OSA-A reached 0.281 mmol-S/g-A at an equilibrium sulfur concentration of 50 ppmw in the model diesel fuel, which was 155% higher than a commercial coal-derived activated carbon and 35% higher than the best commercial activated carbon among all commercial activated carbons examined in our laboratory. The higher ADS capacity of OSA-A can be attributed to its significantly higher density (2.77 {mu}mol/m{sup 2}) of the adsorption sites on the surface as determined by Langmuir adsorption isotherm, which is related to its oxygen-containing functional groups on the carbonaceous surface as revealed by temperature-programmed desorption analysis. 57 refs., 10 figs., 6 tabs.

  14. Macroporous chitosan hydrogels: Effects of sulfur on the loading and release behaviour of amino acid-based compounds.

    PubMed

    Elviri, Lisa; Asadzadeh, Maliheh; Cucinelli, Roberta; Bianchera, Annalisa; Bettini, Ruggero

    2015-11-01

    Chitosan is a biodegradable, biocompatible polymer of natural origin widely applied to the preparation of functional hydrogels suitable for controlled release of drugs, peptides and proteins. Non-covalent interactions, expecially ionic interactions, are the main driver of the loading and release behaviour of amino acids or peptides from chitosan hydrogels. With the aim to improve the understanding of the mechanisms governing the behaviour of chitosan hydrogels on peptide uptake and delivery, in this paper the attention was focused on the role played by sulfur on the interactions of chitosan hydrogels with sulfur-containing amino acids (AA) and peptides. Hence, loading and release experiments on cysteine, cystine and glutathione (SH containing amino acid, dipeptide and tripeptide, respectively) as well as on glycine and valine as apolar amino acids were carried out. For these puroses, chitosan hydrogels were prepared in an easy and reproducible manner by a freeze-gelation process on a poly-L-lysine coated support. The hydrogel surface pore size, uniformity and distribution were tested. Optimal results (D50 = 26 ± 4 μm) were obtained by using the poly-L-lysine positively-charged surface. The loading results gathered evidenced that the sulfur-containing molecules presented an increased absorption both in terms of rate and extent by chitosan hydrogels with respect to nonpolar amino acids, mainly due to ionic and hydrogen bond interactions. ATR-FTIR analysis carried out on chitosan hydrogels, with and without the AA related compounds to study putative interactions, supported these apparent sulfur-dependent results. Finally, chitosan hydrogels displayed excellent retention capabilities (AA release <5%) for all AA, strongly supporting the use of chitosan hydrogels as matrix for controlled drug release. PMID:26256323

  15. Application of a quantitative structure retention relationship approach for the prediction of the two-dimensional gas chromatography retention times of polycyclic aromatic sulfur heterocycle compounds.

    PubMed

    Gieleciak, Rafal; Hager, Darcy; Heshka, Nicole E

    2016-03-11

    Information on the sulfur classes present in petroleum is a key factor in determining the value of refined products and processing behavior in the refinery. A large part of the sulfur present is included in polycyclic aromatic sulfur heterocycles (PASHs), which in turn are difficult to desulfurize. Furthermore, some PASHs are potentially more mutagenic and carcinogenic than polycyclic aromatic hydrocarbons, PAHs. All of this calls for improved methods for the identification and quantification of individual sulfur species. Recent advances in analytical techniques such as comprehensive two-dimensional gas chromatography (GC×GC) have enabled the identification of many individual sulfur species. However, full identification of individual components, particularly in virgin oil fractions, is still out of reach as standards for numerous compounds are unavailable. In this work, a method for accurately predicting retention times in GC×GC using a QSRR (quantitative structure retention relationship) method was very helpful for the identification of individual sulfur compounds. Retention times for 89 saturated, aromatic, and polyaromatic sulfur-containing heterocyclic compounds were determined using two-dimensional gas chromatography. These retention data were correlated with molecular descriptors generated with CODESSA software. Two independent QSRR relationships were derived for the primary as well as the secondary retention characteristics. The predictive ability of the relationships was tested by using both independent sets of compounds and a cross-validation technique. When the corresponding chemical standards are unavailable, the equations developed for predicting retention times can be used to identify unknown chromatographic peaks by matching their retention times with those of sulfur compounds of known molecular structure. PMID:26879453

  16. Immobilization of sulfur in microgels for lithium-sulfur battery.

    PubMed

    Chang, Aiping; Wu, Qingshi; Du, Xue; Chen, Shoumin; Shen, Jing; Song, Qiuyi; Xie, Jianda; Wu, Weitai

    2016-03-15

    Immobilization of sulfur in microgels is achieved via free radical polymerization of commercial poly(ethylene glycol) dimethacrylate in the solution of sulfur-terminated poly(3-oligo(ethylene oxide)4-thiophene), a copolymer prepared by the inverse vulcanization of S8 with allyl-terminated poly(3-oligo(ethylene oxide)4-thiophene). This microgelation leads to enhanced Li-S battery performance over the sulfur-terminated polymer. PMID:26936016

  17. Understanding Sulfur Systematics in Large Igneous Provinces Using Sulfur Isotopes

    NASA Astrophysics Data System (ADS)

    Novikova, S.; Edmonds, M.; Turchyn, A. V.; Maclennan, J.; Svensen, H.; Frost, D. J.; Yallup, C.

    2013-12-01

    The eruption of the Siberian Traps coincided with perhaps the greatest environmental catastrophe in Earth's history, at the Permo-Triassic boundary. The source and magnitude of the volatile emissions, including sulfur, associated with the eruption remain poorly understood yet were critical in forcing environmental change. Two of the primary questions are how much sulfur gases were emitted during the eruptions and from where they were sourced. Primary melts carry dissolved sulfur from the mantle. Magmas ponding in sills and ascending through dykes may also assimilate sulfur from country rocks, as well as heat the country rocks and generate fluids through contact metamorphism. If the magmas interacted thermally, for prolonged periods, with sulfur-rich country rocks then it is probable that the sulfur budget of these eruptions might have been augmented considerably. This is exactly what we have shown recently for a basaltic sill emplaced in oil shale that fed eruptions of the British Tertiary Province, where surrounding sediments showed extensive desulfurization (Yallup et al. Geoch. Cosmochim. Acta, online, 2013). In the current study sulfur isotopes and trace element abundances are used to discriminate sulfur sources and to model magmatic processes for a suite of Siberian Traps sill and lava samples. Our bulk rock and pyrite geochemical analyses illustrate clearly their high abundance of 34S over 32S. The high 34S/32S has been noted previously and linked to assimilation of sulfur from sediments but may alternatively be inherited from the mantle plume source. With the aim of investigating the sulfur isotopic signature in the melt prior to devolatilization, we use secondary ion mass spectrometry (SIMS), for which a specific set of glass standards was synthesised. In order to understand how sulfur isotopes fractionate during degassing we have also conducted a parallel study of well-characterized tephras from Kilauea Volcano, where sulfur degassing behavior is well known.

  18. Aboveground and Belowground Herbivores Synergistically Induce Volatile Organic Sulfur Compound Emissions from Shoots but Not from Roots.

    PubMed

    Danner, Holger; Brown, Phil; Cator, Eric A; Harren, Frans J M; van Dam, Nicole M; Cristescu, Simona M

    2015-07-01

    Studies on aboveground (AG) plant organs have shown that volatile organic compound (VOC) emissions differ between simultaneous attack by herbivores and single herbivore attack. There is growing evidence that interactive effects of simultaneous herbivory also occur across the root-shoot interface. In our study, Brassica rapa roots were infested with root fly larvae (Delia radicum) and the shoots infested with Pieris brassicae, either singly or simultaneously, to study these root-shoot interactions. As an analytical platform, we used Proton Transfer Reaction Mass Spectrometry (PTR-MS) to investigate VOCs over a 3 day time period. Our set-up allowed us to monitor root and shoot emissions concurrently on the same plant. Focus was placed on the sulfur-containing compounds; methanethiol, dimethylsulfide (DMS), and dimethyldisulfide (DMDS), because these compounds previously have been shown to be biologically active in the interactions of Brassica plants, herbivores, parasitoids, and predators, yet have received relatively little attention. The shoots of plants simultaneously infested with AG and belowground (BG) herbivores emitted higher levels of sulfur-containing compounds than plants with a single herbivore species present. In contrast, the emission of sulfur VOCs from the plant roots increased as a consequence of root herbivory, independent of the presence of an AG herbivore. The onset of root emissions was more rapid after damage than the onset of shoot emissions. The shoots of double infested plants also emitted higher levels of methanol. Thus, interactive effects of root and shoot herbivores exhibit more strongly in the VOC emissions from the shoots than from the roots, implying the involvement of specific signaling interactions. PMID:26195194

  19. Factors controlling fluxes of volatile sulfur compounds in Sphagnum peatlands. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Demello, William Zamboni

    1992-01-01

    Exchange of DMS and OCS between the surface of Sphagnum peatlands and the atmosphere were measured with dynamic (S-free sweep air) and static enclosures. DMS emission rates determined by both methods were comparable. The dynamic method provided positive OCS flux rates (emission) for measurements performed at sites containing Sphagnum. Conversely, data from the static method indicated that OCS was consumed from the atmosphere. Short and long-term impacts of increased S deposition on fluxes of volatile S compounds (VSC's) from Sphagnum peatlands were investigated in a poor fen (Mire 239) at the Experimental Lakes Area, Ontario, Canada. Additional experiments were conducted in a poor fen (Sallie's Fen in Barrington, NH, USA). At Mire 239, emissions of VSC's were monitored, before and after acidification, at control and experimental sections within two major physiographic areas of the mire (oligotrophic and minerotrophic). DMS was the predominant VSC released from Mire 239 and varied largely with time and space. Sulfur addition did not affect DMS emissions in a period of hours to a few days. DMS emissions in the experimental oligotrophic area of the mire was approximately 3-fold greater than in the control oligotrophic area, and approximately 10-fold greater than in the minerotrophic zones. These differences could be due to a combination of differences in types of vegetation, nutritional status, and S input. At Sallie's Fen, DMS fluxes were not significantly affected by sulfate amendments, while DMS and MSH concentrations increased greatly with time in the top 10 cm of the peat column. The major environmental factors controlling fluxes of DMS in a Sphagnum-dominated peatland were investigated in Sallie's Fen, NH. DMS emissions from the surface of the peatland varied greatly over 24 hours and seasonally. Temperature seemed to be the major environmental factor controlling these variabilities. Concentrations of dissolved VSC's varied with time and space throughout the fen. Dissolved DMS, MSH, and OCS in the surface of the water table were supersaturated with respect to their concentrations in the atmosphere. Sphagnum mosses did not appear to be a direct source of VSC's, however they increase transport of DMS from the peat surface to the atmosphere.

  20. Influence of Sulfur for Oxygen Substitution in the Solvolytic Reactions of Chloroformate Esters and Related Compounds

    PubMed Central

    D’Souza, Malcolm J.; Kevill, Dennis N.

    2014-01-01

    The replacement of oxygen within a chloroformate ester (ROCOCl) by sulfur can lead to a chlorothioformate (RSCOCl), a chlorothionoformate (ROCSCl), or a chlorodithioformate (RSCSCl). Phenyl chloroformate (PhOCOCl) reacts over the full range of solvents usually included in Grunwald-Winstein equation studies of solvolysis by an addition-elimination (A-E) pathway. At the other extreme, phenyl chlorodithioformate (PhSCSCl) reacts across the range by an ionization pathway. The phenyl chlorothioformate (PhSCOCl) and phenyl chlorothionoformate (PhOCSCl) react at remarkably similar rates in a given solvent and there is a dichotomy of behavior with the A-E pathway favored in solvents such as ethanol-water and the ionization mechanism favored in aqueous solvents rich in fluoroalcohol. Alkyl esters behave similarly but with increased tendency to ionization as the alkyl group goes from 1° to 2° to 3°. N,N-Disubstituted carbamoyl halides favor the ionization pathway as do also the considerably faster reacting thiocarbamoyl chlorides. The tendency towards ionization increases as, within the three contributing structures of the resonance hybrid for the formed cation, the atoms carrying positive charge (other than the central carbon) change from oxygen to sulfur to nitrogen, consistent with the relative stabilities of species with positive charge on these atoms. PMID:25310653

  1. Influence of sulfur for oxygen substitution in the solvolytic reactions of chloroformate esters and related compounds.

    PubMed

    D'Souza, Malcolm J; Kevill, Dennis N

    2014-01-01

    The replacement of oxygen within a chloroformate ester (ROCOCl) by sulfur can lead to a chlorothioformate (RSCOCl), a chlorothionoformate (ROCSCl), or a chlorodithioformate (RSCSCl). Phenyl chloroformate (PhOCOCl) reacts over the full range of solvents usually included in Grunwald-Winstein equation studies of solvolysis by an addition-elimination (A-E) pathway. At the other extreme, phenyl chlorodithioformate (PhSCSCl) reacts across the range by an ionization pathway. The phenyl chlorothioformate (PhSCOCl) and phenyl chlorothionoformate (PhOCSCl) react at remarkably similar rates in a given solvent and there is a dichotomy of behavior with the A-E pathway favored in solvents such as ethanol-water and the ionization mechanism favored in aqueous solvents rich in fluoroalcohol. Alkyl esters behave similarly but with increased tendency to ionization as the alkyl group goes from 1° to 2° to 3°. N,N-Disubstituted carbamoyl halides favor the ionization pathway as do also the considerably faster reacting thiocarbamoyl chlorides. The tendency towards ionization increases as, within the three contributing structures of the resonance hybrid for the formed cation, the atoms carrying positive charge (other than the central carbon) change from oxygen to sulfur to nitrogen, consistent with the relative stabilities of species with positive charge on these atoms. PMID:25310653

  2. The behavior of nitrifying sludge in presence of sulfur compounds using a floating biofilm reactor.

    PubMed

    Beristain-Cardoso, Ricardo; Gómez, Jorge; Méndez-Pampín, Ramón

    2010-11-01

    The tolerance, kinetic and oxidizing capability of a nitrifying sludge exposed to different initial concentrations of sulfide (1.7 to 18mg/L) was evaluated in batch experiments. A nitrifying sludge fed with ammonium and thiosulfate and produced in steady state conditions was used as inoculum. Sulfide induced a significant effect either on ammonium consumption rates or nitrite accumulation. In spite of the nitrifying kinetic was affected, the ammonium consumption efficiencies were close to 100%, with nitrate production yields around 1.0. The IC(50) value for ammonium oxidizing-process was 13mg/L of sulfide. Sulfide was oxidized in two steps: first sulfide was oxidized to elemental sulfur and afterward into sulfate. FISH oligonucleotide probes for Thiobacillusdenitrificans, Nitrosomonas spp., and Nitrobacter spp. were used in order to know if these bacteria were part of the microbial ecology. The obtained results showed that under nitrifying conditions are possible to carry out simultaneously two biological processes, nitrification and sulfur oxidation. PMID:20620047

  3. Oxidation of sulfur compounds in petroleum residues: reactivity-structural relationships

    SciTech Connect

    Petersen, J.C.; Dorrence, S.M.; Nazir, M.; Plancher, H.; Barbour, F.A.

    1981-09-01

    Studies have been made on the reactivity of sulfur entities in oxidized asphalts and oxidized petroleum distillation residues during air oxidation. Asphalts are referred to as residues. The oxidation of these materials includes the rapid formation of an unsymmetrical ir band at ca 1030/cm. Sulfoxides are not normally found in unoxidized petroleum residues, but develop rapidly during air aging. Their presence in these residues has been inferred from their specific bands in ir spectra. Confirmation of sulfoxides was obtained from deoxygenation with chlorocarbenes and decomposition with bromine and peracetic acid. Hydroperoxides in amounts that might interfere with sulfoxide determination were not found in oxidated residues. The concentration of sulfoxides formed during air oxidation was found to rapidly reach a maximum value and to remain constant on further oxidation of the residue. Model studies indicate that hydroperoxides play a role in sulfoxide formation. The data show that both alkyl and aryl sulfides were present in aliphatic residues, that predominantly alkyl types were oxidized during oxidative aging in air and that concentrations of the alkyl and aryl types vary with crude source. Peracetic acid oxidation of the residues indicated that most of the sulfur present was in the form of sulfides. 2 figures, 6 tables.

  4. Catalyst for the reduction of sulfur dioxide to elemental sulfur

    DOEpatents

    Jin, Y.; Yu, Q.; Chang, S.G.

    1996-02-27

    The inventive catalysts allow for the reduction of sulfur dioxide to elemental sulfur in smokestack scrubber environments. The catalysts have a very high sulfur yield of over 90% and space velocity of 10,000 h{sup {minus}1}. They also have the capacity to convert waste gases generated during the initial conversion into elemental sulfur. The catalysts have inexpensive components, and are inexpensive to produce. The net impact of the invention is to make this technology practically available to industrial applications. 21 figs.

  5. Method for reducing the sulfur content of a sulfur-containing hydrocarbon stream

    DOEpatents

    Mahajan, Devinder

    2004-12-28

    The sulfur content of a liquid hydrocarbon stream is reduced under mild conditions by contracting a sulfur-containing liquid hydrocarbon stream with transition metal particles containing the transition metal in a zero oxidation state under conditions sufficient to provide a hydrocarbon product having a reduced sulfur content and metal sulfide particles. The transition metal particles can be produced in situ by adding a transition metal precursor, e.g., a transition metal carbonyl compound, to the sulfur-containing liquid feed stream and sonicating the feed steam/transition metal precursor combination under conditions sufficient to produce the transition metal particles.

  6. Phanerozoic cycles of sedimentary carbon and sulfur.

    PubMed

    Garrels, R M; Lerman, A

    1981-08-01

    A reservoir model of a Recent steady-state sedimentary system in which the reduced sulfur and oxidized sulfur reservoirs were coupled with the oxidized carbon and reduced carbon reservoirs was constructed. The time curve of the sulfur isotope ratios of the sedimentary sulfate reservoir was used to drive the model back to the beginning of Cambrian time (600 million years ago), producing the reservoir sizes and isotope values and material fluxes of the carbon-sulfur system. The predicted values of carbon isotope ratios of the carbonate reservoir agree well with observed values, showing that the model is basically sound. Some general conclusions from this success are (i) material flux rates in the carbon-oxygen-sulfur system of the geologic past (averaged over tens of millions of years) lie within about a factor of 2 of Recent rates. (ii) The oxidation-reduction balances of Phanerozoic time were dominated by reciprocal relationships between carbon and sulfur compounds. (iii) The rate of production of atmospheric oxygen by storage in sediments of organic carbon of photosynthetic origin increased from the Cambrian Period to the Permian Period and declined somewhat from the Permian Period to the Present. (iv) The storage of oxygen in oxidized sulfur compounds kept pace (within the limits of the data) with oxygen production. (v) Transfer of oxygen from CO(2) to SO(4) from the Cambrian to the Permian Period was several times the Recent free oxygen content of the atmosphere. PMID:16593066

  7. Reduced and Oxidized Sulfur Compounds Detected by Evolved Gas Analyses of Materials from Yellowknife Bay, Gale Crater, Mars

    NASA Technical Reports Server (NTRS)

    McAdam, A. C.; Franz, H. B.; Archer, P. D., Jr.; Sutter, B.; Eigenbrode, J. L.; Freissinet, C.; Atreya, S. K.; Bish, D. L.; Blake, D. F.; Brunner, A.; Mahaffy, P. R.; Ming, D. W.; Morris, R. V.; Navarro-Gonzalez, R.; Rampe, E. B.; Steele, A.; Wray, J. J.

    2014-01-01

    Sulfate minerals have been directly detected or strongly inferred from several Mars datasets and indicate that aqueous alteration of martian surface materials has occurred. Indications of reduced sulfur phases (e.g., sulfides) from orbital and in situ investigations of martian materials have been fewer in number, but these phases are observed in martian meteorites and are likely because they are common minor phases in basaltic rocks. Here we discuss potential sources for the S-bearing compounds detected by the Mars Science Laboratory (MSL) Sample Analysis at Mars (SAM) instrument’s evolved gas analysis (EGA) experiments.

  8. Current emission trends for nitrogen oxides, sulfur dioxide, and volatile organic compounds by month and state: Methodology and results

    SciTech Connect

    Kohout, E.J.; Miller, D.J.; Nieves, L.A.; Rothman, D.S.; Saricks, C.L.; Stodolsky, F.; Hanson, D.A.

    1990-08-01

    This report presents estimates of monthly sulfur dioxide (SO{sub 2}), nitrogen oxides (NO{sub x}), and nonmethane voltatile organic compound (VOC) emissions by sector, region, and state in the contiguous United States for the years 1975 through 1988. This work has been funded as part of the National Acid Precipitation Assessment Program`s Emissions and Controls Task Group by the US Department of Energy (DOE) Office of Fossil Energy (FE). The DOE project officer is Edward C. Trexler, DOE/FE Office of Planning and Environment.

  9. Current emission trends for nitrogen oxides, sulfur dioxide, and volatile organic compounds by month and state: Methodology and results

    SciTech Connect

    Kohout, E.J.; Miller, D.J.; Nieves, L.A.; Rothman, D.S.; Saricks, C.L.; Stodolsky, F.; Hanson, D.A.

    1990-08-01

    This report presents estimates of monthly sulfur dioxide (SO{sub 2}), nitrogen oxides (NO{sub x}), and nonmethane voltatile organic compound (VOC) emissions by sector, region, and state in the contiguous United States for the years 1975 through 1988. This work has been funded as part of the National Acid Precipitation Assessment Program's Emissions and Controls Task Group by the US Department of Energy (DOE) Office of Fossil Energy (FE). The DOE project officer is Edward C. Trexler, DOE/FE Office of Planning and Environment.

  10. Finding of thiosulfate pathway for synthesis of organic sulfur compounds in Saccharomyces cerevisiae and improvement of ethanol production.

    PubMed

    Funahashi, Eri; Saiki, Kyohei; Honda, Kurara; Sugiura, Yuki; Kawano, Yusuke; Ohtsu, Iwao; Watanabe, Daisuke; Wakabayashi, Yukari; Abe, Tetsuya; Nakanishi, Tsuyoshi; Suematsu, Makoto; Takagi, Hiroshi

    2015-12-01

    We found that Saccharomyces cerevisiae utilizes thiosulfate as a sole sulfur source. The energetically-favored thiosulfate rather than sulfate as sulfur sources is also more effective for improving growth and ethanol-production rate in S.cerevisiae due to high levels of intracellular NADPH during thiosulfate utilization. PMID:26188417

  11. Rethinking the Ancient Sulfur Cycle

    NASA Astrophysics Data System (ADS)

    Fike, David A.; Bradley, Alexander S.; Rose, Catherine V.

    2015-05-01

    The sulfur biogeochemical cycle integrates the metabolic activity of multiple microbial pathways (e.g., sulfate reduction, disproportionation, and sulfide oxidation) along with abiotic reactions and geological processes that cycle sulfur through various reservoirs. The sulfur cycle impacts the global carbon cycle and climate primarily through the remineralization of organic carbon. Over geological timescales, cycling of sulfur is closely tied to the redox state of Earth's exosphere through the burial of oxidized (sulfate) and reduced (sulfide) sulfur species in marine sediments. Biological sulfur cycling is associated with isotopic fractionations that can be used to trace the fluxes through various metabolic pathways. The resulting isotopic data provide insights into sulfur cycling in both modern and ancient environments via isotopic signatures in sedimentary sulfate and sulfide phases. Here, we review the deep-time δ34S record of marine sulfates and sulfides in light of recent advances in understanding how isotopic signatures are generated by microbial activity, how these signatures are encoded in marine sediments, and how they may be altered following deposition. The resulting picture shows a sulfur cycle intimately coupled to ambient carbon cycling, where sulfur isotopic records preserved in sedimentary rocks are critically dependent on sedimentological and geochemical conditions (e.g., iron availability) during deposition.

  12. Relationship between corrosion and the biological sulfur cycle: A review

    SciTech Connect

    Little, B.J.; Ray, R.I.; Pope, R.K.

    2000-04-01

    Sulfur and sulfur compounds can produce pitting, crevice corrosion, dealloying, stress corrosion cracking, and stress-oriented hydrogen-induced cracking of susceptible metals and alloys. Even though the metabolic by-products of the biological sulfur cycle are extremely corrosive, there are no correlations between numbers and types of sulfur-related organisms and the probability or rate of corrosion, Determination of specific mechanisms for corrosion caused by microbiologically mediated oxidation and reduction of sulfur and sulfur compounds is complicated by the variety of potential metabolic-energy sources and by-products; the coexistence of reduced and oxidized sulfur species; competing reactions with inorganic and organic compounds; and the versatility and adaptability of microorganisms in biofilms. The microbial ecology of sulfur-rich environments is poorly understood because of the association of aerobes and anaerobes and the mutualism or succession of heterotrophs to autotrophs. The physical scale over which the sulfur cycle influences corrosion varies with the environment. The complete sulfur cycle of oxidation and reduction reactions can take place in macroenvironments, including sewers and polluted harbors, or within the microenvironment of biofilms. In this review, reactions of sulfur and sulfur compounds resulting in corrosion were discussed in the context of environmental processes important to corrosion.

  13. TOTAL SULFUR DEPOSITION (WET+DRY) FROM THE ATMOSPHERE

    EPA Science Inventory

    Sulfur Dioxide (SO2) is emitted primarily as a by-product of coal combustion from power plants. Sulfur Dioxide reacts in the atmosphere to form other chemical such as Sulfuric Acid and Amonium Sulfate. These compounds and their secondarily formed constituents deposit to the sur...

  14. TOTAL SULFUR DEPOSITION (WET+DRY) FROM THE ATMOSHERE

    EPA Science Inventory

    Sulfur Dioxide (SO2) is emitted primarily as a by-product of coal combustion from power plants. Sulfur Dioxide reacts in the atmosphere to form other chemical such as Sulfuric Acid and Amonium Sulfate. These compounds and their secondarily formed constituents deposit to the sur...

  15. Accidental fatal inhalation of sulfuric acid fumes.

    PubMed

    Benomran, F A; Hassan, A I; Masood, S S

    2008-01-01

    A man found dead with circumstantial evidence indicating exposure to sulfuric acid vapor. He had been applying a solution of concentrated sulfuric acid to a drain pipe in an attempt to clear a blockage. External examination showed moderate corrosive damage around his mouth and nose, on his forearms and tips of fingers of his left hand. Autopsy revealed congestion of the respiratory passages, as well as severe pulmonary edema. Traces of acid and sulfate compounds were chemically detected in his upper respiratory passages. Death was attributed to accidental inhalation of fumes of strong sulfuric acid during application to blocked drainpipes. PMID:17239648

  16. Sodium sulfur storage battery

    SciTech Connect

    Kagawa, H.; Matsui, K.

    1985-04-09

    The present invention discloses a sodium-sulfur storage battery utilizing an inside of a sodium-ion conductive solid electrolyte tube as a negative chamber, comprising an a-alumina ring jointed with solder glass to an open end of said electrolyte tube, a flange aluminum housing having a fine hole at its bottom incorporated in said solid electrolyte tube, a negative auxiliary cover thermo-compressively jointed through a flange of said aluminum housing to an upper surface of said a-aluminum ring, and a negative cover provided with a negative current collector terminal welded to said negative auxiliary cover.

  17. Method of removing and recovering elemental sulfur from highly reducing gas streams containing sulfur gases

    DOEpatents

    Gangwal, Santosh K.; Nikolopoulos, Apostolos A.; Dorchak, Thomas P.; Dorchak, Mary Anne

    2005-11-08

    A method is provided for removal of sulfur gases and recovery of elemental sulfur from sulfur gas containing supply streams, such as syngas or coal gas, by contacting the supply stream with a catalyst, that is either an activated carbon or an oxide based catalyst, and an oxidant, such as sulfur dioxide, in a reaction medium such as molten sulfur, to convert the sulfur gases in the supply stream to elemental sulfur, and recovering the elemental sulfur by separation from the reaction medium.

  18. FTIR-ATR evaluation of topical skin protectants useful for sulfur mustard and related compounds

    NASA Astrophysics Data System (ADS)

    Braue, Ernest H., Jr.; Litchfield, Marty R.; Bangledorf, Catherine R.; Rieder, Robert G.

    1992-03-01

    The US Army has a need to develop topical protectants that can decrease the effects of cutaneous exposure to chemical warfare (CW) agents. Such materials would enhance a soldier's ability to carry out the mission in a chemically hostile environment, would lessen the burden on medical personnel, and may allow the casualties to return to duty in a shorter period of time than might otherwise be possible. In a preliminary report (E. H. Braue, Jr. and M. G. Pannella, Applied Spectrosc., 44, 1061 (1990)), we described a unique analytical method using FT-IR spectroscopy and the horizontal attenuated total reflectance (ATR) accessory for evaluating the effectiveness of topical skin protectants (TSPs) against penetration by chemical agents. We now describe the application of this method to the chemical warfare agent sulfur mustard (HD).

  19. The South Karelia Air Pollution Study. The effects of malodorous sulfur compounds from pulp mills on respiratory and other symptoms

    SciTech Connect

    Jaakkola, J.J.; Vilkka, V.; Marttila, O.; Jaeppinen, P.H.; Haahtela, T. )

    1990-12-01

    The paper mills in South Karelia, the southeast part of Finland, are responsible for releasing a substantial amount of malodorous sulfur compounds such as hydrogen sulfide (H2S), methyl mercaptan (CH3SH), and methyl sulfides ((CH3)2S and (CH3)2S2), into ambient air. In the most polluted residential area the annual mean concentrations of hydrogen sulfide and methyl mercaptan are estimated to be 8 and 2 to 5 micrograms/m3 and the highest daily average concentration 100 and 50 micrograms/m3. The annual mean and highest daily concentrations of sulfur dioxide (SO2) are very low. We studied the effects of malodorous sulfur compounds on eye, nasal and respiratory symptoms, and headache in adults. A cross-sectional self-administered questionnaire was distributed in February 1987 and responded to by 488 adults living in a severely (n = 198), a moderately (n = 204), and a nonpolluted community (n = 86). This included questions about occurrence of the symptoms of interest during the previous 4 wk and 12 months and individual, behavioral, and other environmental determinants of the symptoms. The response rate was 83%. The odds ratios (OR) for symptoms experienced often or constantly in severely versus nonpolluted and moderately versus nonpolluted communities were estimated in logistic regression analysis controlling potential confounders. The odds ratios for eye (moderate exposure OR 11.70, Cl95% 2.33 to 58.65; severe exposure OR 11.78, Cl95% 2.35 to 59.09) and nasal symptoms (OR 2.01, Cl95% 0.97 to 4.15; OR 2.19, Cl95% 1.06 to 4.55) and cough (OR 1.89, Cl95% 0.61 to 5.86; OR 3.06, Cl95% 1.02 to 9.29) during the previous 12 months were increased, with a dose-response pattern.

  20. Process for removing sulfur from sulfur-containing gases

    DOEpatents

    Rochelle, Gary T.; Jozewicz, Wojciech

    1989-01-01

    The present disclosure relates to improved processes for treating hot sulfur-containing flue gas to remove sulfur therefrom. Processes in accorda The government may own certain rights in the present invention pursuant to EPA Cooperative Agreement CR 81-1531.

  1. Characterization of sulfur compounds in whisky by full evaporation dynamic headspace and selectable one-dimensional/two-dimensional retention time locked gas chromatography-mass spectrometry with simultaneous element-specific detection.

    PubMed

    Ochiai, Nobuo; Sasamoto, Kikuo; MacNamara, Kevin

    2012-12-28

    A method is described for characterization of sulfur compounds in unaged and aged whisky. The method is based on full evaporation dynamic headspace (FEDHS) of 100 μL of whisky samples followed by selectable one-dimensional ((1)D) or two-dimensional ((2)D) retention-time-locked (RTL) gas chromatography (GC)-mass spectrometry (MS) with simultaneous element-specific detection using a sulfur chemiluminescence detector (SCD) and a nitrogen chemiluminescence detector (NCD). Sequential heart-cuts of the 16 sulfur fractions were used to identify each individual sulfur compound in the unaged whisky. Twenty sulfur compounds were positively identified by a MS library search, linear retention indices (LRI), and formula identification using MS calibration software. Additionally eight formulas were also identified for unknown sulfur compounds. Simultaneous heart-cuts of the 16 sulfur fractions were used to produce the (2)D RTL GC-SCD chromatograms for principal component analysis. PCA of the (2)D RTL GC-SCD data clearly demonstrated the difference between unaged and aged whisky, as well as two different whisky samples. Fourteen sulfur compounds could be characterized as key sulfur compounds responsible for the changes in the aging step and/or the difference between two kinds of whisky samples. The determined values of the key sulfur compounds were in the range of 0.3-210 ng mL(-1) (RSD: 0.37-12%, n=3). PMID:23182286

  2. Liquid sulfur mustard exposure.

    PubMed

    Newmark, Jonathan; Langer, Janice M; Capacio, Benedict; Barr, John; McIntosh, Roger G

    2007-02-01

    A 35-year-old active duty service member sustained a 6.5% body surface area burn as a result of exposure to the chemical warfare agent sulfur mustard, which is the most severe mustard exposure of a U.S. military member since World War II that is known to us. New techniques were used to demonstrate the detectable persistence of mustard metabolites in the patient's blood for at least 41 days after exposure, validating these techniques for the first time for a human mustard patient; they were also used for the first time with human mustard blister fluid. The techniques extend eightfold the period of time that mustard exposure can be definitively diagnosed, compared with previous techniques. Although this patient's lesions were never life-threatening, he required 2 weeks of intensive burn care. He has been left with ongoing posttraumatic stress disorder and has had an incomplete dermatological recovery. In a major terrorist attack involving many patients exposed to sulfur mustard, care resources would be depleted quickly. PMID:17357776

  3. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection of Environment ENVIRONMENTAL....4 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...). (c) Sulfur oxides shall be measured in the ambient air as sulfur dioxide by the reference...

  4. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection of Environment ENVIRONMENTAL....4 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...). (c) Sulfur oxides shall be measured in the ambient air as sulfur dioxide by the reference...

  5. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection of Environment ENVIRONMENTAL....4 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...). (c) Sulfur oxides shall be measured in the ambient air as sulfur dioxide by the reference...

  6. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection of Environment ENVIRONMENTAL....4 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...). (c) Sulfur oxides shall be measured in the ambient air as sulfur dioxide by the reference...

  7. Characterizing reduced sulfur compounds emissions from a swine concentrated animal feeding operation

    NASA Astrophysics Data System (ADS)

    Rumsey, Ian C.; Aneja, Viney P.; Lonneman, William A.

    2014-09-01

    Reduced sulfur compounds (RSCs) emissions from concentrated animal feeding operations (CAFOs) have become a potential environmental and human health concern, as a result of changes in livestock production methods. RSC emissions were determined from a swine CAFO in North Carolina. RSC measurements were made over a period of ≈1 week from both the barn and lagoon during each of the four seasonal periods from June 2007 to April 2008. During sampling, meteorological and other environmental parameters were measured continuously. Seasonal hydrogen sulfide (H2S) barn concentrations ranged from 72 to 631 ppb. Seasonal dimethyl sulfide (DMS; CH3SCH3) and dimethyl disulfide (DMDS; CH3S2CH3) concentrations were 2-3 orders of magnitude lower, ranging from 0.18 to 0.89 ppb and 0.47 to 1.02 ppb, respectively. The overall average barn emission rate was 3.3 g day-1 AU-1 (AU (animal unit) = 500 kg of live animal weight) for H2S, which was approximately two orders of magnitude higher than the DMS and DMDS overall average emissions rates, determined as 0.017 g day-1 AU-1 and 0.036 g day-1 AU-1, respectively. The overall average lagoon flux was 1.33 μg m-2 min-1 for H2S, which was approximately an order of magnitude higher than the overall average DMS (0.12 μg m-2 min-1) and DMDS (0.09 μg m-2 min-1) lagoon fluxes. The overall average lagoon emission for H2S (0.038 g day-1 AU-1) was also approximately an order of magnitude higher than the overall average DMS (0.0034 g day-1 AU-1) and DMDS (0.0028 g day-1 AU-1) emissions. H2S, DMS and DMDS have offensive odors and low odor thresholds. Over all four sampling seasons, 77% of 15 min averaged H2S barn concentrations were an order of magnitude above the average odor threshold. During these sampling periods, however, DMS and DMDS concentrations did not exceed their odor thresholds. The overall average barn and lagoon emissions from this study were used to help estimate barn, lagoon and total (barn + lagoon) RSC emissions from swine CAFOs in North Carolina. Total (barn + lagoon) H2S emissions from swine CAFOs in North Carolina were estimated to be 1.22*106 kg yr-1. The barns had significantly higher H2S emissions than the lagoons, contributing ≈98% of total North Carolina H2S swine CAFO emissions. Total (barn + lagoon) emissions for DMS and DMDS were 1-2 orders of magnitude lower, with barns contributing ≈86% and ≈93% of total emissions, respectively. H2S swine CAFO emissions were estimated to contribute ≈18% of North Carolina H2S emissions.

  8. Volume efficient sodium sulfur battery

    DOEpatents

    Mikkor, Mati

    1980-01-01

    In accordance with the teachings of this specification, a sodium sulfur battery is formed as follows. A plurality of box shaped sulfur electrodes are provided, the outer surfaces of which are defined by an electrolyte material. Each of the electrodes have length and width dimensions substantially greater than the thicknesses thereof as well as upwardly facing surface and a downwardly facing surface. An electrode structure is contained in each of the sulfur electrodes. A holding structure is provided for holding the plurality of sulfur electrodes in a stacked condition with the upwardly facing surface of one sulfur electrode in facing relationship to the downwardly facing surface of another sulfur electrode thereabove. A small thickness dimension separates each of the stacked electrodes thereby defining between each pair of sulfur electrodes a volume which receives the sodium reactant. A reservoir is provided for containing sodium. A manifold structure interconnects the volumes between the sulfur electrodes and the reservoir. A metering structure controls the flow of sodium between the reservoir and the manifold structure.

  9. Demonstrating Allotropic Modifications of Sulfur.

    ERIC Educational Resources Information Center

    McCarty, Jillian L.; Dragojlovic, Veljko

    2002-01-01

    Shows how a common demonstration that consists of slowly heating sulfur powder in a test tube to illustrate sulfur's allotropic modifications can convince students of conclusions about the moon Io which they often find surprising. Describes the demonstration in full. (Author/MM)

  10. SULFUR RETENTION IN COAL ASH

    EPA Science Inventory

    The report gives results of an analytical study to assess the potential for sulfur retention in various types of coal-fired boilers. Results of a field test of 10 industrial coal-fired boilers were used to evaluate the impact on sulfur retention of the operating variables (load a...

  11. Sulfur production continues to rise

    SciTech Connect

    Parkinson, G.; Ondrey, G.; Moore, S.

    1994-06-01

    Sulfur is one of the world's most-popular commodities. It has another distinctive feature: most of it is produced from the effluent of chemical process plants. A lot more sulfur will have similar origins in the future as countries tighten up on sulfur emissions in a global effort to reduce acid rain. To meet such stricter controls, new sulfur recovery methods are being developed, and existing ones improved, to extract sulfur more efficiently and cheaply. Among the new developments are improvements in the Claus process--and alternatives to Claus--for the extraction of hydrogen sulfide (H[sub 2]S) from process streams; and new ways to recover elemental sulfur from sulfur dioxide (SO[sub 2]) contained in the flue gas of coal-fired plants. Currently, the common flue gas treatment is scrubbing with limestone or lime, but this produces millions of tons/yr of gypsum sludge that is mostly landfilled. Gypsum can be processed into wallboard, but that market is limited. The paper discusses the use of flue gas as a raw material; a versatile acid production process; alternative processes for H[sub 2]S extraction; and a process that recovers both sulfur and hydrogen.

  12. The Biogeochemistry of Sulfur in Hydrothermal Systems

    NASA Technical Reports Server (NTRS)

    Schulte, Mitchell; Rogers, K. L.; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    The incorporation of sulfur into many biomolecules likely dates back to the development of the earliest metabolic strategies. Sulfur is common in enzymes and co-enzymes and is an indispensable structural component in many peptides and proteins. Early metabolism may have been heavily influenced by the abundance of sulfide minerals in hydrothermal systems. The incorporation of sulfur into many biomolecules likely dates back to the development of the earliest metabolic strategies. Sulfur is common in enzymes and co-enzymes and is an indispensable structural component in many peptides and proteins. Early metabolism may have been heavily influenced by the abundance of sulfide minerals in hydrothermal systems. Understanding how sulfur became prevalent in biochemical processes and many biomolecules requires knowledge of the reaction properties of sulfur-bearing compounds. We have previously estimated thermodynamic data for thiols, the simplest organic sulfur compounds, at elevated temperatures and pressures. If life began in hydrothermal environments, it is especially important to understand reactions at elevated temperatures among sulfur-bearing compounds and other organic molecules essential for the origin and persistence of life. Here we examine reactions that may have formed amino acids with thiols as reaction intermediates in hypothetical early Earth hydrothermal environments. (There are two amino acids, cysteine and methionine, that contain sulfur.) Our calculations suggest that significant amounts of some amino acids were produced in early Earth hydrothermal fluids, given reasonable concentrations H2, NH3, H2S and CO. For example, preliminary results indicate that glycine activities as high as 1 mmol can be reached in these systems at 100 C. Alanine formation from propanethiol is also a favorable reaction. On the other hand, the calculated equilibrium log activities of cysteine and serine from propanethiol are -21 and -19, respectively, at 100 C. These results indicate that while amino acid formation with thiols as intermediates is favored in some cases, other mechanisms may have been necessary to produce significant amounts of other amino acids. Coupled with our previous results for thiols, these studies imply that sulfur may have been easily incorporated into the organic geochemistry of early Earth hydrothermal systems, leading to its widespread use in biomolecules. Formation of more complex biomolecules in hydrothermal systems may have required sulfur-bearing organic compounds as reaction intermediates.

  13. Theoretical studies of the marine sulfur cycle

    NASA Technical Reports Server (NTRS)

    Toon, Owen B.; Kasting, James B.; Liu, May S.

    1985-01-01

    Several reduced sulfur compounds are produced by marine organisms and then enter the atmosphere, where they are oxidized and ultimately returned to the ocean or the land. The oceanic dimethyl sulfide (DMS) flux, in particular, represents a significant fraction of the annual global sulfur input to the atmosphere. In the atmosphere, this gas is converted to sulfur dioxide (SO2), methane sulfonic acid, and other organic acids which are relatively stable and about which little is known. SO2 is a short lived gas which, in turn, is converted to sulfuric acid and other sulfate compounds which contribute significantly to acid rain. Because of the complexity of the sulfur system, it is not well understood even in the unperturbed atmosphere. However, a number of new observations and experiments have led to a significant increase in the understanding of this system. A number of one dimensional model experiments were conducted on the gas phase part of the marine sulfur cycle. The results indicate the measured concentration of DMS and the amplitude of its diurnal cycle are in agreement with estimates of its global flux. It was also found that DMS can make a large contribution to the background SO2 concentration in the free troposphere. Estimates of CS2 concentrations in the atmosphere are inconsistent with estimated fluxes; however, measured reaction rates are consistent with the observed steep tropospheric gradient in CS2. Observations of CS2 are extremely sparse. Further study is planned.

  14. Reactions of SIV species with organic compounds: formation mechanisms of organo-sulfur derivatives in atmospheric aerosols

    NASA Astrophysics Data System (ADS)

    Passananti, Monica; Shang, Jing; Dupart, Yoan; Perrier, Sébastien; George, Christian

    2015-04-01

    Secondary organic aerosol (SOA) have an important impact on climate, air quality and human health. However the chemical reactions involved in their formation and growth are not fully understood or well-constrained in climate models. It is well known that inorganic sulfur (mainly in oxidation states (+IV) and (+VI)) plays a key role in aerosol formation, for instance sulfuric acid is known to be a good nucleating gas. In addition, acid-catalyzed heterogeneous reactions of organic compounds has shown to produce new particles, with a clear enhancement in the presence of ozone (Iinuma 2013). Organosulfates have been detected in tropospheric particles and aqueous phases, which suggests they are products of secondary organic aerosol formation process (Tolocka 2012). Originally, the production of organosulfates was explained by the esterification reaction of alcohols, but this reaction in atmosphere is kinetically negligible. Other formation pathways have been suggested such as hydrolysis of peroxides and reaction of organic matter with sulfite and sulfate radical anions (SO3-, SO4-) (Nozière 2010), but it remains unclear if these can completely explain atmospheric organo-sulfur aerosol loading. To better understand the formation of organo-sulfur compounds, we started to investigate the reactivity of SIV species (SO2 and SO32-) with respect to specific functional groups (organic acids and double bonds) on atmospherically relevant carboxylic acids and alkenes. The experiments were carried out in the homogeneous aqueous phase and at the solid-gas interface. A custom built coated-wall flow tube reactor was developed to control relativity humidity, SO2 concentration, temperature and gas flow rate. Homogeneous and heterogeneous reaction kinetics were measured and resulting products were identified using liquid chromatography coupled with an orbitrap mass spectrometer (LC-HR-MS). The experiments were performed with and without the presence of ozone in order to evaluate any impact on the SIV oxidation and product formation. Preliminary results reveal that oxidation of SIV species can occur under a variety of atmospherically relevant conditions. Furthermore, LC-HR-MS analysis confirms the formation of organo-sulfur compounds that could derive from sulfate and/or the sulfite radical anion. These results elucidate the role of organo-sulfates aqueous and interfacial chemistry, important for our scientific understanding of atmospheric SOA formation. Iinuma Y., Kahnt A., Mutzel A., Böge O., Herrmann H., Environ. Sci. Technol., 2013, (47), 3639-3647, DOI: 10.1021/es305156z. Mauldin III R. L., Berndt T., Sipilä M., Paasonen P., Petäjä T., Kim S., Kurtén T., Stratmann F., Kerminen V.-M., Kulmala M., Nature, 2012, (488), 193-196, DOI: 10.1038/nature11278. Nozière B., Ekström S., AlsbergT., Holmström S., Geophys. Res. Lett., 2010, (37), 1-6, DOI: 10.1029/2009GL041683. Tolocka M.P., Turpin B., Environ. Sci. Technol., 2012, (46), 7978-7983, DOI: 10.1021/es300651v.

  15. Inhibition of Ammonia Oxidation in Nitrosomonas europaea by Sulfur Compounds: Thioethers Are Oxidized to Sulfoxides by Ammonia Monooxygenase

    PubMed Central

    Juliette, Lisa Y.; Hyman, Michael R.; Arp, Daniel J.

    1993-01-01

    Organic sulfur compounds are well-known nitrification inhibitors. The inhibitory effects of dimethylsulfide, dimethyldisulfide, and ethanethiol on ammonia oxidation by Nitrosomonas europaea were examined. Both dimethylsulfide and dimethyldisulfide were weak inhibitors of ammonia oxidation and exhibited inhibitory characteristics typical of substrates for ammonia monooxygenase (AMO). Depletion of dimethylsulfide required O2 and was prevented with either acetylene or allylthiourea, two inhibitors of AMO. The inhibition of ammonia oxidation by dimethylsulfide was examined in detail. Cell suspensions incubated in the presence of ammonia oxidized dimethylsulfide to dimethyl sulfoxide. Depletion of six other thioethers was also prevented by treating cell suspensions with either allylthiourea or acetylene. The oxidative products of three thioethers were identified as the corresponding sulfoxides. The amount of sulfoxide formed accounted for a majority of the amount of sulfide depleted. By using gas chromatography coupled with mass spectrometry, allylmethylsulfide was shown to be oxidized to allylmethylsulfoxide by N. europaea with the incorporation of a single atom of 18O derived from 18O2 into the sulfide. This result supported our conclusion that a monooxygenase was involved in the oxidation of allylmethylsulfide. The thioethers are concluded to be a new class of substrates for AMO. This is the first report of the oxidation of the sulfur atom by AMO in whole cells of N. europaea. The ability of N. europaea to oxidize dimethylsulfide is not unique among the ammonia-oxidizing bacteria. Nitrosococcus oceanus, a marine nitrifier, was also demonstrated to oxidize dimethylsulfide to dimethyl sulfoxide. PMID:16349086

  16. Assessment of sulfur removal processes for advanced fuel cell systems

    NASA Astrophysics Data System (ADS)

    Lorton, G. A.

    1980-01-01

    The performance characteristics of potential sulfur removal processes were evaluated and four of these processes, the Selexol process, the Benfield process, the Sulfinol process, and the Rectisol process, were selected for detailed technical and economic comparison. The process designs were based on a consistent set of technical criteria for a grass roots facility with a capacity of 10,000 tons per day of Illinois No. 6 coal. Two raw gas compositions, based on oxygen blown and air blown Texaco gasification, were used. The bulk of the sulfur was removed in the sulfur removal unit, leaving a small amount of sulfur compounds in the gas. The remaining sulfur compounds were removed by reaction with zinc oxide in the sulfur polishing unit. The impact of COS hydrolysis pretreatment on sulfur removal was evaluated. Comprehensive capital and O and M cost estimates for each of the process schemes were developed.

  17. Oxidation of Elemental Sulfur by Sulfolobus acidocaldarius

    PubMed Central

    Shivvers, Douglas W.; Brock, Thomas D.

    1973-01-01

    Oxidation of elemental sulfur by Sulfolobus acidocaldarius, an autotroph which grows at high temperatures and low pH, was examined by use of 35S-labeled elemental sulfur. When cultured at pH 3.2 and 70 C, S. acidocaldarius oxidized elemental sulfur essentially quantitatively to sulfuric acid. Oxidation rate paralleled growth rate and decrease in pH of the culture medium. Elemental sulfur was not oxidized under these conditions if the culture was poisoned with formaldehyde. During the growth phase, the proportion of cells attached to the sulfur crystals increased progressively, and in the later phases of growth over 10 times more cells were attached to sulfur than were free. Doubling times for eight strains growing on elemental sulfur varied from 37 to 55 h. The organism grows much more rapidly on yeast extract than on sulfur. In a medium containing both sulfur and yeast extract, sulfur oxidation was partially inhibited, although growth was excellent. PMID:4706192

  18. Post-SL9 Sulfur Photochemistry on Jupiter

    NASA Technical Reports Server (NTRS)

    Moses, Julianne I.; Allen, Mark; Gladstone, G. Randall

    1995-01-01

    We have modeled the photochemical evolution of the sulfur containing species that were observed in Jupiter's stratosphere after the Shoemaker Levy 9 (SL9) impacts. We find that most of the sulfur is converted to S8 in the first few days. Other important sulfur reservoirs are CS, whose abundance increases markedly with time, and possibly H2CS, HNCS, and NS, whose abundances depend on kinetic reaction rates that are unknown at the present. We discuss the temporal variation of the major sulfur compounds, make abundance and compositional predictions useful for comparison with observations, and discuss the possible condensation of sulfur containing species.

  19. Biological production and spatial variation of dimethylated sulfur compounds and their relation with plankton in the North Yellow Sea

    NASA Astrophysics Data System (ADS)

    Li, Cheng-Xuan; Yang, Gui-Peng; Wang, Bao-Dong

    2015-07-01

    The concentrations of dimethylated sulfur compounds and chlorophyll a, as well as biological production and consumption rates of dimethylsulfide (DMS), were measured in the surface water of the North Yellow Sea (NYS, 37-40°N to 121-124°E) in winter 2007. Surface DMS, dissolved and particulate dimethylsulfoniopropionate (DMSPd and DMSPp) concentrations in the study area increased significantly from offshore to inshore sites, with the average values of 2.00, 4.52 and 7.21 nM, respectively. The biological production and consumption rates of DMS were estimated, with the average values of 5.41 and 3.84 nM d-1, respectively. The spatial variation of chlorophyll a was consistent with that of DMS and DMSP, as well as with that of DMS biological production, suggesting that phytoplankton biomass might play an important role in controlling the distribution of DMS and DMSP in the study area. According to the collective data of dimethylated sulfur compounds and DMS biological conversion in China Seas, the dimethylated sulfur compounds concentrations in the NYS during winter were a factor of 2 and 1.3 higher than those in the East China Sea and South China Sea, respectively. Less DMS (DMSP) in NYS was released in winter than that in spring and summer, which could be attributed to the shift in phytoplankton community composition dominated by diatoms to non-diatoms from winter to summer. Quantitative comparison analysis pointed to DMSPp rather than DMSPd as an important precursor of DMS in the surface water. The estimated sea-to-air fluxes of DMS using Liss and Merlivat (LM86), Wanninkhof (W92) and Nightingale (N2000) formulae were 2.72, 5.12 and 4.28 μmol m-2 d-1, respectively. In the surface water, the biological turnover time of DMS varied from 0.21 to 1.73 d with an average of 0.83 d, which was about 5.43-fold faster than the mean DMS sea-air turnover time (3.12 d), implying that microbial consumption was a main sink of DMS in the surface water.

  20. Characterizing reduced sulfur compounds and non-methane volatile organic compounds emissions from a swine concentrated animal feeding operation

    NASA Astrophysics Data System (ADS)

    Rumsey, Ian Cooper

    Reduced sulfur compounds (RSCs) and non-methane volatile organic compounds (NMVOCs) emissions from concentrated animal feeding operations (CAFOs) have become a potential environmental and human health concern. Both RSCs and NMVOCs contribute to odor. In addition, RSCs also have the potential to form fine particulate matter (PMfine) and NMVOCs the potential to form ozone. Measurements of RSCs and NMVOCs emissions were made from both an anaerobic lagoon and barn at a swine CAFO in North Carolina. Emission measurements were made over all four seasonal periods. In each seasonal period, measurements were made from both the anaerobic lagoon and barn for ˜1 week. RSC and NMVOCs samples were collected using passivated canisters. Nine to eleven canister samples were taken from both the lagoon and barn over each sampling period. The canisters were analyzed ex-situ using gas chromatography flame ionization detection (GC-FID). Hydrogen sulfide (H2S) measurements were made in-situ using a pulsed fluorescence H2S/SO2 analyzer. During sampling, measurements of meteorological and physiochemical parameters were made. H2S had the largest RSC flux, with an overall average lagoon flux of 1.33 mug m-2 min-1. The two main RSCs identified by the GC-FID, dimethyl sulfide (DMS) and dimethyl disulfide (DMDS), had overall average lagoon fluxes an order of magnitude lower, 0.12 and 0.09 mug m-2 min-1, respectively. Twelve significant NMVOCs were identified in lagoon samples (ethanol, 2-ethyl-1-hexanol, methanol, acetaldehyde, decanal, heptanal, hexanal, nonanal, octanal, acetone, methyl ethyl ketone, and 4-methylphenol). The overall average fluxes for these NMVOCs, ranged from 0.08 mug m-2 min-1 (4-methylphenol) to 2.11 mug m-2 min-1 (acetone). Seasonal H2S barn concentrations ranged from 72-631 ppb. DMS and DMDS seasonal concentrations were 2-3 orders of magnitude lower. There were six significant NMVOCs identified in barn samples (methanol, ethanol, acetone 2-3 butanedione, acetaldehyde and 4-methylphenol). Their overall average NMVOCs concentrations ranged from 2.87 ppb (4-methylphenol) to 16.21 ppb (ethanol). The overall average barn normalized emissions were 3.3 g day-1 AU-1 (AU (animal unit) = 500 kg) for H2S, 0.018 g day-1 AU-1 for DMS and 0.037 g day -1 AU-1 for DMDS. Normalized overall average NMVOC emissions ranged from 0.45 g day-1 AU-1 for ethanol to 0.16 g day-1 AU-1 for acetaldehyde. Barn H2S concentrations were generally one to two orders of magnitude above their odor thresholds. DMDS concentrations also regularly exceeded the lower limit of an odor threshold. Four NMVOCs (2-3 butanedione, decanal, 4-methylphenol and nonanal) had barn concentrations exceeding an odor threshold. Using overall average lagoon and barn emissions, the emissions from swine CAFOs in North Carolina were estimated. H2S had the largest RSC emission with an estimated North Carolina emission of 1.46 million kg yr -1, which was ˜21% of total North Carolina H2S emissions. Ethanol was the NMVOC with the largest North Carolina emission with an emission of 206,367 kg yr-1.

  1. Sulfur condensation in Claus catalyst

    SciTech Connect

    Schoffs, G.R.

    1985-02-01

    The heterogeneous reactions in which catalyst deactivation by pore plugging occur are listed and include: coke formation in petroleum processing, especially hydrocracking and hydrodesulfurization catalysts; steam reforming and methnation catalysts; ammonia synthesis catalyst; and automobile exhause catalysts. The authors explain how the Claus process converts hydrogen sulfide produced by petroleum desulfurization units and gas treatment processes into elemental sulfur and water. More than 15 million tons of sulfur are recovered annually by this process. Commercial Claus plants appear to operate at thermodynamic equilibrium. Depending on the H2S content of the feed and the number of reactors, total H2S conversion to elemental sulfur can exceed 95%.

  2. Genetic engineering of sulfur-degrading Sulfolobus

    SciTech Connect

    Ho, N.W.Y. . Lab. of Renewable Resources Engineering)

    1990-01-01

    Recent studies have shown that some microorganisms can play a significant role in removing the sulfur compounds from coal. Sulfolobus acidocaldarius is one such microorganism. Some microorganisms can remove only organic sulfur from coal, other can remove only inorganic sulfur from coal, but S. acidocaldarius seems to be able to remove both the organic and the inorganic sulfur from coal. Furthermore, S. acidocaldarius has been shown to be able to use the sulfur and carbon derived from coal as its sole carbon and energy source for growth. These properties make this microorganism unique for coal desulfurization. This project is aimed at applying recombinant DNA techniques to improve the capability of S. acidocaldarius for coal desulfurization, which includes making it the host for housing foreign genes that encode the most effective enzymes for coal desulfurization. Since there is no established vectors and procedures for introducing vectors into S. acidocaldarius and related microorganisms, the immediate goal is to establish a gene cloning system for this species. During the present quarter, the authors have studied a few systems which can be used as the potential selection mechanism for the selection of the desired transformants. In addition, they also analyzed the extracellular proteins from S. acidocaldarius as well as other potential organic sulfur removing species and also managed to obtain most strains and plasmids that are needed for this work. Results to date are given. 1 tab.

  3. Deep sulfur cycle

    NASA Astrophysics Data System (ADS)

    Shimizu, N.; Mandeville, C. W.

    2009-12-01

    Geochemical cycle of sulfur in near-surface reservoirs has been a subject of intense studies for decades. It has been shown that sulfur isotopic compositions of sedimentary sulfides and sulfates record interactions of the atmosphere, hydrosphere, biosphere and lithosphere, with δ34S of sedimentary sulfides continuously decreasing from 0‰ toward present-day values of ~-30 to -40‰ over the Phanerozoic (e.g., Canfield, 2004). It has also been shown that microbial reduction of the present-day seawater sulfate (δ34S=+21‰) results in large shifts in isotopic compositions of secondary pyrites in altered oceanic crust (to δ34S=-70‰: Rouxel et al., 2009). How much of these near surface isotopic variations survive during deep geochemical cycle of sulfur interacting with the mantle infinite reservoir with δ34S=0‰? Could extent of their survival be used as a tracer of processes and dynamics involved in deep geochemical cycle? As a first step toward answering these questions, δ34S was determined in-situ using a Cameca IMS 1280 ion microprobe at Woods Hole Oceanographic Institution in materials representing various domains of deep geochemical cycle. They include pyrites in altered MORB as potential subducting materials and pyrites in UHP eclogites as samples that have experienced subduction zone processes, and mantle-derived melts are represented by olivine-hosted melt inclusions in MORB and those in IAB, and undegassed submarine OIB glasses. Salient features of the results include: (1) pyrites in altered MORB (with O. Rouxel; from ODP site 801 and ODP Hole 1301B) range from -70 to +19‰, (2) pyrites in UHP eclogites from the Western Gneiss Region, Norway (with B. Hacker and A. Kylander-Clark) show a limited overall range from -3.4 to + 2.8‰ among five samples, with one of them covering almost the entire range, indicating limited scale lengths of isotopic equilibration during subduction, (3) olivine-hosted melt inclusions in arc basalts from Galunggung (-2.8 - +5.2‰ with majority between +3 and +5), Krakatau (+1.5 - +8.6‰ with a cluster around +3 - +5), and Augustine (+8 - +12‰) show larger variations among arc magmas than previously known, (4) olivine-hosted melt inclusions from a FAMOUS lava (519-4-1) range from -9.5 to +10.5‰, and (5) undegassed submarine glasses from Samoa (with M. Jackson) appear to show separate ranges for individual islands, including Vailulu clustering around -1.9 to +2.1‰ and Malumalu ranging from -0.9 to -12.1‰. Overall, the results clearly show that low temperature signatures are not completely erased during recycling and isotopic exchange with the mantle infinite reservoir, and that mantle-derived melts still display large isotopic variations for small sampling scales, similar to observations on other isotope systems. Canfield, D. E. (2004) Amer. Jour. Sci., 304, 839-861. Rouxel, O. et al., (2009) Goldschmidt Conf. Abstract.

  4. The significance of glucosinolates for sulfur storage in Brassicaceae seedlings

    PubMed Central

    Aghajanzadeh, Tahereh; Hawkesford, Malcolm J.; De Kok, Luit J.

    2014-01-01

    Brassica juncea seedlings contained a twofold higher glucosinolate content than B. rapa and these secondary sulfur compounds accounted for up to 30% of the organic sulfur fraction. The glucosinolate content was not affected by H2S and SO2 exposure, demonstrating that these sulfur compounds did not form a sink for excessive atmospheric supplied sulfur. Upon sulfate deprivation, the foliarly absorbed H2S and SO2 replaced sulfate as the sulfur source for growth of B. juncea and B. rapa seedlings. The glucosinolate content was decreased in sulfate-deprived plants, though its proportion of organic sulfur fraction was higher than that of sulfate-sufficient plants, both in absence and presence of H2S and SO2. The significance of myrosinase in the in situ turnover in these secondary sulfur compounds needs to be questioned, since there was no direct co-regulation between the content of glucosinolates and the transcript level and activity of myrosinase. Evidently, glucosinolates cannot be considered as sulfur storage compounds upon exposure to excessive atmospheric sulfur and are unlikely to be involved in the re-distribution of sulfur in B. juncea and B. rapa seedlings upon sulfate deprivation. PMID:25566279

  5. Effect of reduced sulfur compounds on the fermentation of phosphoric acid pretreated sugarcane bagasse by ethanologenic Escherichia coli.

    PubMed

    Nieves, I U; Geddes, C C; Miller, E N; Mullinnix, M T; Hoffman, R W; Fu, Z; Tong, Z; Ingram, L O

    2011-04-01

    The addition of reduced sulfur compounds (thiosulfate, cysteine, sodium hydrosulfite, and sodium metabisulfite) increased growth and fermentation of dilute acid hydrolysate of sugarcane bagasse by ethanologenic Escherichia coli (strains LY180, EMFR9, and MM160). With sodium metabisulfite (0.5mM), toxicity was sufficiently reduced that slurries of pretreated biomass (10% dry weight including fiber and solubles) could be fermented by E. coli strain MM160 without solid-liquid separation or cleanup of sugars. A 6-h liquefaction step was added to improve mixing. Sodium metabisulfite also caused spectral changes at wavelengths corresponding to furfural and soluble products from lignin. Glucose and cellobiose were rapidly metabolized. Xylose utilization was improved by sodium metabisulfite but remained incomplete after 144 h. The overall ethanol yield for this liquefaction plus simultaneous saccharification and co-fermentation process was 0.20 g ethanol/g bagasse dry weight, 250 L/tonne (61 gal/US ton). PMID:21353535

  6. Amplification of vacuole-targeting fungicidal activity of antibacterial antibiotic polymyxin B by allicin, an allyl sulfur compound from garlic.

    PubMed

    Ogita, Akira; Nagao, Yasuhiro; Fujita, Ken-Ichi; Tanaka, Toshio

    2007-08-01

    A cationic antibacterial peptide, polymyxin B (PMB), was evaluated as an antifungal antibiotic against various yeasts and filamentous fungi when used in combination with allicin, an allyl sulfur compound from garlic. Allicin was not lethal but could markedly amplify the fungicidal activity of PMB, which was weakly detected with the increase in the plasma membrane permeability in Saccharomyces cerevisiae. Their combined actions caused a dynamic structural damage to the yeast vacuole as judged by the disappearance of its swollen spherical architecture. The vacuole-targeting activity of PMB was similarly amplified in medium with t-butyl hydroperoxide as a substitute for the action of allicin. These findings suggest that the allicin-mediated lipoperoxide production in fungal plasma membrane is the cause of the enhancement in the cellular uptake of PMB as well as its action against the vacuole. PMID:17827662

  7. Stability and P-V-T Equations of State of High-Pressure Iron-Sulfur Compounds

    NASA Astrophysics Data System (ADS)

    Frank, M. R.; Fei, Y.; Mibe, K.; Watson, H.

    2003-12-01

    It has long been hypothesized that iron and perhaps sulfur are important contributors to the cores of terrestrial planets. In order to assess the incorporation of sulfur in a metallic iron core, we must understand phase relations in the Fe-S system at high pressure and temperature. The absence of structure and pressure-density data for the Fe3S2 and Fe2S high-pressure phases limits the ability to fully characterize the Fe-S system at high pressure and temperature. In this study, we report new experimental results on the stability, in-situ structure, and P-V-T equations of state of the high-pressure iron-sulfur compounds. Experiments were performed in a multi-anvil apparatus using an 8/3 assembly at beamline BL04B1 in the SPring-8 synchrotron facility. FeS and Fe were mixed in appropriate proportions (Fe3S2 and Fe2S) and loaded into a MgO capsule. The MgO capsule material was also utilized as an internal pressure calibrant. The Fe-FeS mixtures were first pressurized to about 20 GPa at room temperature. The sample was then heated with a rhenium foil heater to 1073 K and held at that temperature for two to four hours to promote formation of the high-pressure Fe-S phase. Temperatures were measured using a W0.05Re-W0.26Re thermocouple. X-ray diffraction data of the samples were collected at appropriate time intervals to address reaction kinetics. The relative intensities of the diffraction lines associated with metallic Fe and the high-pressure Fe-S compounds (Fe3S2 or Fe2S) decreased and increased, respectively, with time. The observed diffraction peaks at simultaneous high pressure and temperature will be used to determine the in-situ structures of Fe3S2 and Fe2S. We also obtained P-V-T data for Fe3S whose structure type has been previously determined, over a wide pressure-temperature range. These data will be used to constructed density profiles of S-bearing iron cores and to evaluate core composition models

  8. Sulfur dimers adsorbed on Au(111) as building blocks for sulfur octomers formation: A density functional study

    SciTech Connect

    Hernandez-Tamargo, Carlos E.; Montero-Alejo, Ana Lilian; Pujals, Daniel Codorniu; Mikosch, Hans

    2014-07-28

    Experimental scanning tunneling microscopy (STM) studies have shown for more than two decades rectangular formations when sulfur atoms are deposited on Au(111) surfaces. The precursors have ranged from simple molecules or ions, such as SO{sub 2} gas or sulfide anions, to more complex organosulfur compounds. We investigated, within the framework of the Density Functional Theory, the structure of these rectangular patterns assuming them entirely composed of sulfur atoms as the experimental evidence suggests. The sulfur coverage at which the simulations were carried out (0.67 ML or higher) provoked that the sulfur-sulfur association had to be taken into account for achieving a good agreement between the sets of simulated and experimental STM images. A combination of four sulfur dimers per rectangular formation properly explained the trends obtained by the experimental STM analysis which were related with the rectangles' size and shape fluctuations together with sulfur-sulfur distances within these rectangles. Finally, a projected density of states analysis showed that the dimers were capable of altering the Au(5d) electronic states at the same level as atomic sulfur adsorbed at low coverage. Besides, sulfur dimers states were perfectly distinguished, whose presence near and above the Fermi level can explain both: sulfur-sulfur bond elongation and dimers stability when they stayed adsorbed on the surface at high coverage.

  9. Comparison of microbial sulfuric acid production in sewage sludge from added sulfur and thiosulfate

    SciTech Connect

    Tyagi, R.D.; Blais, J.F.; Deschenes, L.

    1994-09-01

    Microbial leaching is one of the most attractive methods of removing toxic metals from sewage sludge. Sulfuric acid produced by indigenous microflora by the oxidation of elemental sulfur and sulfur compounds solubilizes toxic metals. The oxidation of sulfur compounds can be achieved by the direct oxidation to sulfates or by indirect oxidation, through the production and accumulation of soluble intermediate S{sub 2}O{sub 3}{sup 2}{sup -}, S{sub 3}O{sup 6}{sup 2}{sup -}, S{sub 4}O{sub 6}{sup 2}{sup -} compounds. The production of these intermediates may create a potential danger of acidification of the receiving waters or the agricultural soil where the leached sludge is ultimately destined, via slow oxidation of the intermediates with subsequent sulfuric acid production. The objective of this research was to investigate the formation of S{sub 2}O{sub 3}{sup 2}{sup -}, S{sub 3}O{sub 6}{sup 2}{sup -}, and S{sub 4}O{sub 6}{sup 2} during metal bioleaching using elemental sulfur and thiosulfate as energy substrates for growth of indigenous thiobacilli (sulfur-oxidizing microorganisms) in sludge. The results obtained showed that intermediates were not formed when elemental sulfur was used as a substrate, whereas trithionate and tetrathionate and tetrathionate accumulated in the sludges when thiosulfate was used as substrate. Moreover, the metabolism of thiosulfate was much slower than that of elemental sulfur in sludge medium. Therefore, the utilization of thiosulfate for the growth of indigenous thiobacilli in sewage sludge is a less attractive alternative for the metal bioleaching. 33 refs., 3 figs., 2 tabs.

  10. The Science and Application of Critical Loads for Deposition of Nitrogen and Sulfur Compounds in National Parks

    NASA Astrophysics Data System (ADS)

    Porter, E.

    2008-12-01

    The National Parks of the U.S. contain resources of unsurpassed beauty and ecological significance. Park managers are directed to preserve the scenery and natural resources in these parks unimpaired for future generations. However, air pollution can damage the very resources that parks were created to preserve and, often, air pollution originates from outside park boundaries and therefore beyond the National Park Service's management jurisdiction. The Clean Air Act provides a framework and certain tools for protecting park resources from air pollution, but despite these programs, air pollution impacts to national park resources are widespread, including acidification or eutrophication from atmospheric deposition of nitrogen and sulfur compounds. Advances in ecosystem research and modeling have allowed national park managers to use critical loads to better evaluate ecosystem condition and set clear management goals for parks. Critical loads define the amount of deposition, usually nitrogen or sulfur compounds, below which harmful effects to a given resource are not expected. Resource protection goals based on critical loads, in turn, can be communicated to federal and State air regulatory agencies, and incorporated into air quality management planning for ecosystem protection. For example, the National Park Service, the Colorado Department of Public Health and Environment, and the Environmental Protection Agency have collaborated to use a critical load to set goals for a nitrogen deposition reduction plan to remedy ecosystem impacts in Rocky Mountain National Park. Elevated nitrogen deposition to the park has caused changes in the type and abundance of aquatic plant species, elevated levels of nitrate in surface waters, elevated levels of nitrogen in spruce needles, long-term accumulation of nitrogen in forest soils, and a shift in alpine tundra plant communities favoring sedges and grasses over the natural wildflower flora. The plan calls for nitrogen deposition to be reduced gradually over 20 years, to ultimately ensure ecosystem recovery and protection.

  11. 46 CFR 148.04-20 - Sulfur.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Sulfur. 148.04-20 Section 148.04-20 Shipping COAST GUARD... Special Additional Requirements for Certain Material § 148.04-20 Sulfur. (a) When sulfur is loaded in a deep hold with general cargo in the 'tween deck hold above the sulfur, a dust proof wooden...

  12. Method of preparing graphene-sulfur nanocomposites for rechargeable lithium-sulfur battery electrodes

    SciTech Connect

    Liu, Jun; Lemmon, John P; Yang, Zhenguo; Cao, Yuliang; Li, Xiaolin

    2015-04-07

    A method of preparing a graphene-sulfur nanocomposite for a cathode in a rechargeable lithium-sulfur battery comprising thermally expanding graphite oxide to yield graphene layers, mixing the graphene layers with a first solution comprising sulfur and carbon disulfide, evaporating the carbon disulfide to yield a solid nanocomposite, and grinding the solid nanocomposite to yield the graphene-sulfur nanocomposite. Rechargeable-lithium-sulfur batteries having a cathode that includes a graphene-sulfur nanocomposite can exhibit improved characteristics. The graphene-sulfur nanocomposite can be characterized by graphene sheets with particles of sulfur adsorbed to the graphene sheets. The sulfur particles have an average diameter of less than 50 nm.

  13. Toxicology of sulfur in ruminants: review

    SciTech Connect

    Kandylis, K.

    1984-10-01

    This review deals with the toxicology of sulfur in ruminants including toxicity, neurotoxic effects, and mechanism of toxic action of hydrogen sulfide, clinical signs, and treatment. It will report effects of excessive intake of sulfur by ruminants on feed intake, animal performance, ruminal digestion and motility, rumination, and other physiological functions. Poisoning of animals with sulfur from industrial emissions (sulfur dioxide) also is discussed. Excessive quantities of dietary sulfur (above .3 to .4%) as sulfate or elemental sulfur may cause toxic effects and in extreme cases can be fatal. The means is discussed whereby consumption of excessive amounts of sulfur leads to toxic effects. 53 references, 1 table.

  14. Alkali metal/sulfur battery

    DOEpatents

    Anand, Joginder N.

    1978-01-01

    Alkali metal/sulfur batteries in which the electrolyte-separator is a relatively fragile membrane are improved by providing means for separating the molten sulfur/sulfide catholyte from contact with the membrane prior to cooling the cell to temperatures at which the catholyte will solidify. If the catholyte is permitted to solidify while in contact with the membrane, the latter may be damaged. The improvement permits such batteries to be prefilled with catholyte and shipped, at ordinary temperatures.

  15. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection of Environment ENVIRONMENTAL....4 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). Link to an... to or greater than 0.005 ppm shall be rounded up). (c) Sulfur oxides shall be measured in the...

  16. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection of Environment ENVIRONMENTAL....5 National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The level... than 0.05 ppm shall be rounded up). (b) Sulfur oxides shall be measured in the ambient air as...

  17. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection of Environment ENVIRONMENTAL....17 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level of the national primary 1-hour annual ambient air quality standard for oxides of sulfur is 75...

  18. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection of Environment ENVIRONMENTAL....5 National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The level... than 0.05 ppm shall be rounded up). (b) Sulfur oxides shall be measured in the ambient air as...

  19. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection of Environment ENVIRONMENTAL....17 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level of the national primary 1-hour annual ambient air quality standard for oxides of sulfur is 75...

  20. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection of Environment ENVIRONMENTAL....5 National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The level... than 0.05 ppm shall be rounded up). (b) Sulfur oxides shall be measured in the ambient air as...

  1. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection of Environment ENVIRONMENTAL....17 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level of the national primary 1-hour annual ambient air quality standard for oxides of sulfur is 75...

  2. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection of Environment ENVIRONMENTAL....17 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level of the national primary 1-hour annual ambient air quality standard for oxides of sulfur is 75...

  3. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection of Environment ENVIRONMENTAL....5 National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The level... than 0.05 ppm shall be rounded up). (b) Sulfur oxides shall be measured in the ambient air as...

  4. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection of Environment ENVIRONMENTAL....5 National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The level... than 0.05 ppm shall be rounded up). (b) Sulfur oxides shall be measured in the ambient air as...

  5. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection of Environment ENVIRONMENTAL....17 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level of the national primary 1-hour annual ambient air quality standard for oxides of sulfur is 75...

  6. Graphene-sulfur nanocomposites for rechargeable lithium-sulfur battery electrodes

    SciTech Connect

    Liu, Jun; Lemmon, John P; Yang, Zhenguo; Cao, Yuiliang; Li, Xiaolin

    2014-06-17

    Rechargeable lithium-sulfur batteries having a cathode that includes a graphene-sulfur nanocomposite can exhibit improved characteristics. The graphene-sulfur nanocomposite can be characterized by graphene sheets with particles of sulfur adsorbed to the graphene sheets. The sulfur particles have an average diameter less than 50 nm..

  7. Process for production of synthesis gas with reduced sulfur content

    DOEpatents

    Najjar, Mitri S.; Corbeels, Roger J.; Kokturk, Uygur

    1989-01-01

    A process for the partial oxidation of a sulfur- and silicate-containing carbonaceous fuel to produce a synthesis gas with reduced sulfur content which comprises partially oxidizing said fuel at a temperature in the range of 1800.degree.-2200.degree. F. in the presence of a temperature moderator, an oxygen-containing gas and a sulfur capture additive which comprises an iron-containing compound portion and a sodium-containing compound portion to produce a synthesis gas comprising H.sub.2 and CO with a reduced sulfur content and a molten slag which comprises (i) a sulfur-containing sodium-iron silicate phase and (ii) a sodium-iron sulfide phase. The sulfur capture additive may optionally comprise a copper-containing compound portion.

  8. Sulfur minimization in bacterial leaching

    SciTech Connect

    Seth, R.; Prasad, D.; Henry, J.G.

    1996-11-01

    The production of sewage biosolids in Ontario in 1989 was estimated to be 7 million m{sup 3} of wet sludge per year. Of this amount, land application accounts for between 20 and 30% of the total. Unfortunately, the use of sewage biosolids on agricultural land is often prohibited because of heavy metal contamination of the biosolids. High cost and operational problems have made chemical methods of metal extraction unattractive. Consequently, microbiological methods of leaching of heavy metals have been studied for over a decade. A relatively simple microbiological process has been investigated in recent years in flask level experiments and recently in a semicontinuous system. The process exploits nonacidophilic and acidophilic indigenous thiobacilli to extract heavy metals from sewage biosolids. These thiobacilli use elemental sulfur as the energy source, producing sulfuric acid. However, the resulting decontaminated biosolids can cause environmental problems like acidification of the soil, when acid is generated from the residual sulfur in the biosolids. The present study examines the possibility of reducing the amount of sulfur added in batch and semicontinuous bacterial leaching systems, and maximizing sulfur oxidation efficiency, thereby reducing the residual sulfur in leached biosolids.

  9. Io's Sulfur: Surface Distribution and Chemical Nature of Impurities

    NASA Astrophysics Data System (ADS)

    Kargel, J. S.; MacIntyre, T.; Dalton, B.; Clark, R.

    2000-10-01

    Galileo SSI and NIMS data have returned a wealth of information on the surface composition of Io. Our analysis suggests that elemental sulfur and sulfur dioxide are nearly ubiquitous but that the ratio of these two materials varies widely. Some of the most spectacular concentrations of elemental sulfur occur near major volcanoes and hotspots. In these areas the color and spectral signature of sulfur and any other materials present varies widely, in some cases forming concentrically zoned deposits around calderas. The spectral variability of sulfur may be due to many mechanisms; inclusion of minor impurities is among the possible controls. We have made some tentative identifications of possible impurities-- iron (as opaque inclusions of FeS disseminated in sulfur) appears to cause the green coloration of some deposits on Io-- including Io's so-called "golf courses." Arsenic, selenium, and tellurium (dissolved in quenched sulfur polymers and/or bonded in stoichiometric compounds with sulfur) may contribute to reddish coloration of other deposits. As little as one percent of these impurities may produce marked changes in the spectral reflectance and color of sulfur. However, other mechanisms can account for Io's reds; Io's green deposits are harder to explain in the absence of pyrite or other metallic sulfide inclusions in elemental sulfur; the logical alternative, ultramafic silicates, has fallen out of favor with the Galileo team due to absence of a diagnostic band near 0.9 microns. These colored forms of impure sulfur have been observed both in nature (in terrestrial volcanogenic native sulfur) and in recent lab specimens quenched from the molten state and containing controlled quantities of impurities (cf abstract by MacIntyre et al., this volume). Evidence for impurities in Io's sulfur will be presented, and we will offer a glimpse into possible geological process implications of the distribution of sulfur on Io and the impurities that may be present in Io's sulfur.

  10. Thermophilic Carbon-Sulfur-Bond-Targeted Biodesulfurization

    PubMed Central

    Konishi, J.; Ishii, Y.; Onaka, T.; Okumura, K.; Suzuki, M.

    1997-01-01

    Petroleum contains many heterocyclic organosulfur compounds refractory to conventional hydrodesulfurization carried out with chemical catalysts. Among these, dibenzothiophene (DBT) and DBTs bearing alkyl substitutions are representative compounds. Two bacterial strains, which have been identified as Paenibacillus strains and which are capable of efficiently cleaving carbon-sulfur (C--S) bonds in DBT at high temperatures, have been isolated for the first time. Upon attacking DBT and its various methylated derivatives at temperatures up to 60(deg)C, both growing and resting cells of these bacteria can release sulfur atoms as sulfate ions and leave the monohydroxylated hydrocarbon moieties intact. Moreover, when either of these paenibacilli was incubated at 50(deg)C with light gas oil previously processed through hydrodesulfurization, the total sulfur content in the oil phase clearly decreased. PMID:16535672

  11. Export of anthropogenic reactive nitrogen and sulfur compounds from the East Asia region in spring

    NASA Astrophysics Data System (ADS)

    Koike, M.; Kondo, Y.; Kita, K.; Takegawa, N.; Masui, Y.; Miyazaki, Y.; Ko, M. W.; Weinheimer, A. J.; Flocke, F.; Weber, R. J.; Thornton, D. C.; Sachse, G. W.; Vay, S. A.; Blake, D. R.; Streets, D. G.; Eisele, F. L.; Sandholm, S. T.; Singh, H. B.; Talbot, R. W.

    2003-10-01

    Measurements of gaseous and particulate reactive nitrogen and sulfur species, as well as other chemical species, were made using the P-3B and DC-8 aircraft over the western Pacific during the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) experiment, conducted between February and April 2001. These measurements provide a good opportunity to study the extent to which anthropogenic NOx and SO2 emitted over the East Asian countries remain as NOy and SOx (=SO2 + nssSO42-) in the form of gas or fine particles when an air mass is transported into the western Pacific region. In this paper a method to estimate transport efficiencies, ɛ(NOy) and ɛ(SOx), in an air mass that has experienced multiple injection, mixing, and loss processes is described. In this analysis, CO and CO2 are used as passive tracers of transport, and the emission inventories of CO, CO2, NOx, and SO2 over the East Asia region are used. Results from the P-3B presented in this study indicate that 20-40% and 15% of NOx emitted over the northeastern part of China remained as NOy over the western Pacific in the boundary layer (BL) and free troposphere (FT), respectively. In the FT, PAN is found to have been the dominant form of NOy, while only 0.5% of emitted NOx remained as NOx. The transport efficiency of SOx is estimated to have been 25-45% and 15-20% in the BL and FT, respectively. Median values of the nssSO42-/SOx ratio are 0.4-0.6 both in the BL and FT, however large variability is found in the FT. These results are generally consistent with those derived using DC-8 data. The results obtained in this study indicate that more than half of NOy and SOx were lost over the continent and that the vertical transport from the BL to FT further reduced their amounts by a factor of 2, likely due to wet removal. Budgets of NOy and SOx were also studied for air masses, which we sampled during TRACE-P and the flux out from the continent in these cases is estimated to be 20% of the emissions. Flux in the BL and FT is found to have a similar contribution.

  12. Production of ultra-low-sulfur gasoline: an equilibrium and kinetic analysis on adsorption of sulfur compounds over Ni/MMS sorbents.

    PubMed

    Subhan, Fazle; Liu, B S; Zhang, Q L; Wang, W S

    2012-11-15

    High performance nickel-based micro-mesoporous silica (Ni/MMS) sorbent was prepared by incipient wetness impregnation with ultrasonic aid (IWI-u) for adsorptive desulfurization (ADS) of commercial gasoline and simulated fuels. The sorbents were characterized with BET, XRD, TPR, SEM, HRTEM and TG/DTG. These results show that 20 wt%Ni/MMS (IWI-u) can still retain the framework of MMS and nickel particles were homogeneously distributed in the MMS channels without any aggregation, which improved significantly the ADS performance of the sorbents. The studies on the ADS kinetics indicate that the adsorption behavior of thiophene (T), benzothiophene (BT) and dibenzothiophene (DBT) over 20 wt%Ni/MMS (IWI-u) can be described appropriately by pseudo second-order kinetic model. The intraparticle diffusion model verified that the steric hindrance and intraparticle diffusion were the rate controlling step of the adsorption process of DBT molecules. Langmuir model can be used to describe the adsorption isotherms for T, BT and DBT due to low coverage. The regeneration sorbent maintains the sulfur removal efficiency of 85.9% for 6 cycles. PMID:23022413

  13. Organic sulfur compounds resulting from the interaction of iron sulfide, hydrogen sulfide and carbon dioxide in an anaerobic aqueous environment

    NASA Astrophysics Data System (ADS)

    Heinen, Wolfgang; Lauwers, Anne Marie

    1996-04-01

    The reaction of iron sulfide (FeS) with H2S in water, in presence of CO2 under anaerobic conditions was found to yield H2 and a variety of organic sulfur compounds, mainly thiols and small amounts of CS2 and dimethyldisulfide. The same compounds were produced when H2S was replaced by HCl, in the H2S-generating system FeS/HCl/CO2. The identification of the products was confirmed by GC-MS analyses and the incorporation of H2 in the organic sulfur compounds was demonstrated by experiments in which all hydrogen compounds were replaced by deuterium compounds. Generation of H2 and the synthesis of thiols were both dependent upon the relative abundance of FeS and HCl or H2S, i.e. the FeS/HCl- or FeS/H2S-proportions. Whether thiols or CS2 were formed as the main products depended also on the FeS/HCl-ratio: All conditions which create a H2 deficiency were found to initiate a proportional increase in the amount of CS2. The quantities of H2 and thiols generated depended on temperature: the production of H2 was significantly accelerated from 50°C onward and thiol synthesis above 75°C. The yield of thiols increased with the amount of FeS and HCl (H2S), given a certain FeS/HCl-ratio and a surplus of CO2. A deficiency of CO2 results in lower thiol systhesis. The end product, pyrite (FeS2), was found to appear as a silvery granular layer floating on the aqueous surface. The identity of the thiols was confirmed by mass spectrometry, and the reduction of CO2 demonstrated by the determination of deuterium incorporation with DCl and D2O. The described reactions can principally proceed under the conditions comparable to those obtaining around submarine hydrothermal vents, or the global situation about 4 billion years ago, before the dawn of life, and could replace the need for a reducing atmosphere on the primitive earth.

  14. Microwave Remote Sensing of the Temperature and Distribution of Sulfur Compounds in the Lower Atmosphere of Venus

    NASA Astrophysics Data System (ADS)

    Jenkins, Jon M.; Kolodner, Marc A.; Butler, Bryan J.; Suleiman, Shady H.; Steffes, Paul G.

    2002-08-01

    A multi-wavelength radio frequency observation of Venus was performed on April 5, 1996, with the Very Large Array to investigate potential variations in the vertical and horizontal distribution of temperature and the sulfur compounds sulfur dioxide (SO 2) and sulfuric acid vapor (H 2SO 4(g)) in the atmosphere of the planet. Brightness temperature maps were produced which feature significantly darkened polar regions compared to the brighter low-latitude regions at both observed frequencies. This is the first time such polar features have been seen unambiguously in radio wavelength observations of Venus. The limb-darkening displayed in the maps helps to constrain the vertical profile of H 2SO 4(g), temperature, and to some degree SO 2. The maps were interpreted by applying a retrieval algorithm to produce vertical profiles of temperature and abundance of H 2SO 4(g) given an assumed sub-cloud abundance of SO 2. The results indicate a substantially higher abundance of H 2SO 4(g) at high latitudes (above 45°) than in the low-latitude regions. The retrieved temperature profiles are up to 25 K warmer than the profile obtained by the Pioneer Venus sounder probe at altitudes below 40 km (depending on location and assumed SO 2 abundance). For 150 ppm of SO 2, it is more consistent with the temperature profile obtained by Mariner 5, extrapolated to the surface via a dry adiabat. The profiles obtained for H 2SO 4(g) at high latitudes are consistent with those derived from the Magellan radio occultation experiments, peaking at around 8 ppm at an altitude of 46 km and decaying rapidly away from that altitude. At low latitudes, no significant H 2SO 4(g) is observed, regardless of the assumed SO 2 content. This is well below that measured by Mariner 10 (Lipa and Tyler 1979, Icarus39, 192-208), which peaked at ˜14 ppm near 47 km. Our results favor ≤100 ppm of SO 2 at low latitudes and ≤50 ppm in polar regions. The low-latitude value is statistically consistent with the results of Bézard et al. (1983, Geophs. Res. Lett.20, 1587-1590), who found that a sub-cloud SO 2 abundance of 130±40 ppm best matched their observations in the near-IR. The retrieved temperature profile and higher abundance of H 2SO 4(g) in polar regions are consistent with a strong equatorial-to-polar, cloud-level flow due to a Hadley cell in the atmosphere of Venus.

  15. Effect of the size factors on the heterophase interaction of exogenous refractory compound nanoparticles with sulfur in a model nickel melt

    NASA Astrophysics Data System (ADS)

    Anuchkin, S. N.; Burtsev, V. T.; Samokhin, A. V.; Gvozdkov, I. A.

    2012-03-01

    The dependence of the degree of sulfur removal on the size factors is studied during the heterophase interaction of refractory compound nanoparticles in a nickel melt. These factors are the time of holding of Al2O3 and TiN nanoparticles in a liquid metal (2-10 min), the size and number of Al2O3 and TiN nanoparticles, the time of processing of a nickel powder with nanoparticles in a planetary mill (0-300 min), and the sulfur concentration in a Ni-(0.0775-0.1750 wt %) S melt. It is shown that the degree of sulfur removal increases as the average size of Al2O3 nanoparticles decreases from 150 to 35 nm and that of TiN nanoparticles decreases from 2 × 104 to 30 nm. The effect of the number of Al2O3 nanoparticles in a metal on the degree of sulfur removal is considered. A change in the time of processing of a powder mixture in a planetary mill is found to weakly affect the degree of sulfur removal.

  16. TECHNIQUE FOR MEASURING REDUCED FORMS OF SULFUR IN AMBIENT AIR

    EPA Science Inventory

    A new technique for measuring low concentrations of volatile sulfur compounds in ambient air is discussed. The technique consists of preconcentration of sulfur compounds by chemisorption on gold metal coated sand or gold foil surface followed by thermal desorption, separation, an...

  17. Optimizing stratospheric sulfur geoengineering by seasonally changing sulfur injections

    NASA Astrophysics Data System (ADS)

    Laakso, Anton; Partanen, Antti-Ilari; Kokkola, Harri; Lehtinen, Kari; Korhonen, Hannele

    2015-04-01

    Solar radiation management (SRM) by stratospheric sulfur injection has been shown to have potential in counteracting global warming if reducing of greenhouse gases has not been achieved fast enough and if climate warming will continue. Injecting large amounts of sulfate particles to the stratosphere would increase the reflectivity of the atmosphere and less sunlight would reach the surface. However, the effectivity (per injected sulphur mass unit) of this kind of geoengineering would decrease when amount of injected sulfur is increased. When sulfur concentration increases, stratospheric particles would grow to larger sizes which have larger gravitational settling velocity and which do not reflect radiation as efficiently as smaller particles. In many previous studies, sulfur has been assumed to be injected along the equator where yearly mean solar intensity is the highest and from where sulfur is spread equally to both hemispheres. However, the solar intensity will change locally during the year and sulfate has been assumed to be injected and spread to the hemisphere also during winter time, when the solar intensity is low. Thus sulfate injection could be expected to be more effective, if sulfur injection area is changed seasonally. Here we study effects of the different SRM injection scenarios by using two versions of the MPI climate models. First, aerosol spatial and temporal distributions as well as the resulting radiative properties from the SRM are defined by using the global aerosol-climate model ECHAM6.1-HAM2.2-SALSA. After that, the global and regional climate effects from different injection scenarios are predicted by using the Max Planck Institute's Earth System Model (MPI-ESM). We carried out simulations, where 8 Tg of sulfur is injected as SO2 to the stratosphere at height of 20-22 km in an area ranging over a 20 degree wide latitude band. Results show that changing the sulfur injection area seasonally would lead to similar global mean shortwave radiative forcing (-4.41 W/m2 at top of atmosphere) as if sulfur is injected only to the equator (-4.40 W/m2). However zonal mean distribution would be different and forcing is concentrated relatively more to the midlatitudes and less to the equator. Cooling effect from the geoengineering and warming effect from the increased greenhouse gas has been shown in many studies to lead to cooling in the equator and warming in the poles compared the preindustrial conditions. Changing the injection area seasonally might prevent this from happening and lead globally to more homogeneous temperature change.

  18. Some Experiments in Sulfur-Nitrogen Chemistry.

    ERIC Educational Resources Information Center

    Banister, Arthur J.; Smith, Nigel R. M.

    1982-01-01

    Briefly surveys the main structural types of sulfur-nitrogen compounds, and describes syntheses, suitable as undergraduate experiments, which illustrate four of the five types of cyclic species. Laboratory procedures, background information, and discussion of results for these experiments are provided. (Author/JN)

  19. Are we getting enough sulfur in our diet?

    PubMed

    Nimni, Marcel E; Han, Bo; Cordoba, Fabiola

    2007-01-01

    Sulfur, after calcium and phosphorus, is the most abundant mineral element found in our body. It is available to us in our diets, derived almost exclusively from proteins, and yet only 2 of the 20 amino acids normally present in proteins contains sulfur. One of these amino acids, methionine, cannot be synthesized by our bodies and therefore has to be supplied by the diet. Cysteine, another sulfur containing amino acid, and a large number of key metabolic intermediates essential for life, are synthesized by us, but the process requires a steady supply of sulfur.Proteins contain between 3 and 6% of sulfur amino acids. A very small percentage of sulfur comes in the form of inorganic sulfates and other forms of organic sulfur present in foods such as garlic, onion, broccoli, etc.The minimal requirements (RDA) for all the essential amino acids have always been estimated in terms of their ability to maintain a nitrogen balance. This method asses amino acid requirements for protein synthesis, only one of the pathways that methionine follows after ingestion. To adequately evaluate the RDA for methionine, one should perform, together with a nitrogen balance a sulfur balance, something never done, neither in humans nor animals.With this in mind we decided to evaluate the dietary intake of sulfur (as sulfur amino acids) in a random population and perform sulfur balance studies in a limited number of human volunteers. Initially this was done to try and gain some information on the possible mode of action of a variety of sulfur containing compounds (chondroitin sulfate, glucosamine sulfate, and others, ) used as dietary supplements to treat diseases of the joints. Out of this study came information that suggested that a significant proportion of the population that included disproportionally the aged, may not be receiving sufficient sulfur and that these dietary supplements, were very likely exhibiting their pharmacological actions by supplying inorganic sulfur. PMID:17986345

  20. Are we getting enough sulfur in our diet?

    PubMed Central

    Nimni, Marcel E; Han, Bo; Cordoba, Fabiola

    2007-01-01

    Sulfur, after calcium and phosphorus, is the most abundant mineral element found in our body. It is available to us in our diets, derived almost exclusively from proteins, and yet only 2 of the 20 amino acids normally present in proteins contains sulfur. One of these amino acids, methionine, cannot be synthesized by our bodies and therefore has to be supplied by the diet. Cysteine, another sulfur containing amino acid, and a large number of key metabolic intermediates essential for life, are synthesized by us, but the process requires a steady supply of sulfur. Proteins contain between 3 and 6% of sulfur amino acids. A very small percentage of sulfur comes in the form of inorganic sulfates and other forms of organic sulfur present in foods such as garlic, onion, broccoli, etc. The minimal requirements (RDA) for all the essential amino acids have always been estimated in terms of their ability to maintain a nitrogen balance. This method asses amino acid requirements for protein synthesis, only one of the pathways that methionine follows after ingestion. To adequately evaluate the RDA for methionine, one should perform, together with a nitrogen balance a sulfur balance, something never done, neither in humans nor animals. With this in mind we decided to evaluate the dietary intake of sulfur (as sulfur amino acids) in a random population and perform sulfur balance studies in a limited number of human volunteers. Initially this was done to try and gain some information on the possible mode of action of a variety of sulfur containing compounds (chondroitin sulfate, glucosamine sulfate, and others, ) used as dietary supplements to treat diseases of the joints. Out of this study came information that suggested that a significant proportion of the population that included disproportionally the aged, may not be receiving sufficient sulfur and that these dietary supplements, were very likely exhibiting their pharmacological actions by supplying inorganic sulfur. PMID:17986345

  1. Sulfur chemistry in dense interstellar clouds

    NASA Astrophysics Data System (ADS)

    Prasad, S. S.; Huntress, W. T., Jr.

    1982-09-01

    A model is presented for the gas phase chemistry of molecules containing sulfur in dense interstellar clouds. The sulfur chemistry is different from that used in previous models as a result of an extensive search of the recent literature and the availability of new laboratory data. The changes have a significant effect on the calculated abundance of sulfur compounds. The linked chemistry of sulfur and oxygen in the present model requires a severe depletion of sulfur and low fractional abundances of both O and O2 in the dense clouds. In contrast, the high abundance of SO and the low abundance of CS relative to SO in the HVS in the KL may indicate an oxygen-rich, high temperature environment compared to OMC-1. The formation of S-H bonds is slow because of the absence of radiative association between S(+) and H2. The present model underestimates the abundance of H2S unless a radiative association reaction between HS(+) and H2 is postulated.

  2. Neutralization and biodegradation of sulfur mustard

    SciTech Connect

    Harvey, S.P.; Beaudry, W.T.; Szafraniec, L.L.

    1995-12-31

    One technology recommended for consideration for the disposal of the U.S. Chemical Stockpile is chemical neutralization followed by biodegradation. In the case of sulfur mustard ({open_quotes}mustard gas{close_quotes}, 2,2{prime}-dichlorodiethyl sulfide), alkaline hydrolysis yields a detoxified and biodegradable product. The hydrolysis reaction was studied with respect to the effects of temperature and sulfur mustard concentration on the rate and products of the reaction. A 28-fold overall rate enhancement was observed at 70{degrees}C vs. 30{degrees}C corresponding to an enthalpy of activation value of 17.9 Kcal/mole. Material balance studies conducted by {sup 1}H Nuclear Magnetic Resonance analysis showed that the products of the reaction consisted of thiodiglycol was relatively greater at lower sulfur mustard concentrations and higher temperatures. As temperatures were decreased or sulfur mustard concentrations was increased, the proportion of ether-type compounds increased accordingly. Conditions of 1% (vol//vol) sulfur mustard, 5% stoichiometric excess of NaOH and 90{degrees}C were selected for generation of the hydrolyzed bioreactor influent material. The bioreactor was seeded with activated sludge and was initially operated as 5 liter sequencing batch reactor with a hydraulic residence time of approximately days. Early results show total organic carbon removal of greater than 90%.

  3. Sulfuric acid in the Venus clouds.

    NASA Technical Reports Server (NTRS)

    Sill, G. T.

    1972-01-01

    The extremely dry nature of the Venus upper atmosphere appears to demand the presence of an efficient desiccating agent as the chief constituent of the clouds of Venus. On the basis of polarization measures it is to be expected that this substance is present as spherical droplets, 1 to 2 microns in diameter, with a refractive index n of 1.46 plus or minus 0.02 at 3500A in the observed region of the atmosphere, with T about equal to 235 K. This substance must have ultraviolet, visible, and infrared reflection properties not inconsistent with the observed spectrum of Venus. Sulfuric acid, of about 86% by weight composition, roughly fulfills the first of these properties. The visible and ultraviolet transmission features of a thin layer of elemental bromine and hydrobromic acid dissolved in sulfuric acid somewhat resemble the Venus spectrum, up to 14 microns. The chemical process postulated for forming sulfuric acid involves the oxidation of sulfur and its compounds to sulfuric acid through the agency of elemental bromine produced by the photolytic decomposition of hydrogen bromide.

  4. Sulfur chemistry in dense interstellar clouds

    NASA Technical Reports Server (NTRS)

    Prasad, S. S.; Huntress, W. T., Jr.

    1982-01-01

    A model is presented for the gas phase chemistry of molecules containing sulfur in dense interstellar clouds. The sulfur chemistry is different from that used in previous models as a result of an extensive search of the recent literature and the availability of new laboratory data. The changes have a significant effect on the calculated abundance of sulfur compounds. The linked chemistry of sulfur and oxygen in the present model requires a severe depletion of sulfur and low fractional abundances of both O and O2 in the dense clouds. In contrast, the high abundance of SO and the low abundance of CS relative to SO in the HVS in the KL may indicate an oxygen-rich, high temperature environment compared to OMC-1. The formation of S-H bonds is slow because of the absence of radiative association between S(+) and H2. The present model underestimates the abundance of H2S unless a radiative association reaction between HS(+) and H2 is postulated.

  5. Reaction of dialkyl disulfides with elemental sulfur

    SciTech Connect

    Gizutollina, I.K.; Fakhriev, A.M.; Fazliev, D.F.; Mazgarov, A.M.

    1986-06-01

    The authors study the reaction of a dialkyl disulfides with elemental sulfur in the presence of catalytic amounts of the amine compounds N-dimethylpropylenediamine and N,N'-tetramethylidipropylenetriamine. All of the data obtained indicate that the reaction of dialkyl disulfide with element sulfur in the presence of an amine is accompanied by the formation of a mixture of dialkyl polysulfides. Since the composition of the dialkyl disulfides obtained during the purification of compressed gases, the broad light hydrocarbon fraction, and benzine fractions from mercaptans varies depending on the content of the corresponding mercaptans in the crude material being purified, when they are used as sulfur extractants, a mixture of different high-molecular-weight dialkyl polysulfides may be obtained and isolated if necessary. It is noted that the Raman spectra were obtained on a PHO laser Raman spectrometer (He-Ne laser).

  6. Influence of Sulfur Species on Current Efficiency in the Aluminum Smelting Process

    NASA Astrophysics Data System (ADS)

    Meirbekova, Rauan; Haarberg, Geir Martin; Thonstad, Jomar; Saevarsdottir, Gudrun

    2016-04-01

    Anode impurities are the major source of sulfur in aluminum electrolysis. Sulfur in anodes is mainly found as organic compounds. Alumina also introduces small quantities of sulfur, typically in the form of sulfates. The scarcity and cost of low-sulfur raw materials and the possibility of sulfur removal from the cell by means of flue gas may make high-sulfur content anodes a viable option. However, some anode impurities are known to affect current efficiency in aluminum production and caution must be exercised. The effect of increased sulfur content in the aluminum electrolysis electrolyte must be studied. This paper explores the effect of increased sulfur concentration in the electrolyte on current efficiency in a laboratory cell. Sodium sulfate was added to the electrolyte as a source of sulfur at regular time intervals to maintain a constant sulfur concentration. Current efficiency decreased by 1.1 pct per each 100 mg/kg (ppm) increase in sulfur concentration in the electrolyte.

  7. Io's theothermal (sulfur) - Lithosphere cycle inferred from sulfur solubility modeling of Pele's magma supply

    NASA Astrophysics Data System (ADS)

    Battaglia, Steven M.; Stewart, Michael A.; Kieffer, Susan W.

    2014-06-01

    Surface deposits of volatile compounds such as water (Earth) or sulfur (Io) on volcanically active bodies suggest that a magmatic distillation process works to concentrate volatiles in surface reservoirs. On Earth, this is the combined hydrologic and tectonic cycle. On Io, sulfurous compounds are transferred from the interior to the surface reservoirs through a combination of a mantle-sourced magmatic system, vertical cycling of the lithosphere, and a sulfur-dominated crustal thermal system that we here call the "theothermal" system. We present a geochemical analysis of this process using previously inferred temperature and oxygen fugacity constraints of Pele's basaltic magma to determine the behavior of sulfur in the ionian magmas. Sulfate to sulfide ratios of Pele's magma are -4.084 ± 0.6 and -6.442 ± 0.7 log10 units, comparable to or lower than those of mid-ocean ridge basalts. This reflects the similarity of Io's oxidation state with Earth's depleted mantle as previously suggested by Zolotov and Fegley (Zolotov, M.Y., Fegley, B. [2000]. Geophys. Res. Lett. 27, 2789-2792). Our calculated limits of sulfur solubility in melts from Pele's patera (˜1100-1140 ppm) are also comparable to terrestrial mid-ocean ridge basalts, reflecting a compositional similarity of mantle sources. We propose that the excess sulfur obvious on Io's surface comes from two sources: (1) an insoluble sulfide liquid phase in the magma and (2) theothermal near-surface recycling.

  8. Sulfur-doped ordered mesoporous carbons: A stability-improving sulfur host for lithium-sulfur battery cathodes

    NASA Astrophysics Data System (ADS)

    Nitze, Florian; Fossum, Kjell; Xiong, Shizhao; Matic, Aleksandar; Palmqvist, Anders E. C.

    2016-06-01

    We report on sulfur-functionalized ordered mesoporous carbons aimed for lithium-sulfur battery electrode applications with improved charge capacity retention. The carbons were obtained by a hard-template strategy using a mixture of furfuryl alcohol and furfuryl mercaptan. For the application as electrode material in lithium-sulfur batteries, the carbons were additionally loaded with sulfur following a traditional melt-diffusion approach. It was found that the sulfur interacts stronger with the sulfur-functionalized carbon matrix than with the non-functionalized material. Electrodes showed very high capacity in the second discharge-charge cycle amounting to approximately 1500, 1200 and 1400 mAh/g (sulfur) for carbon materials with no, medium and high degrees of sulfur functionalization, respectively. More importantly, the sulfur-functionalization of the carbon was found to increase the capacity retention after 50 discharge-charge cycles by 8 and 5% for the carbons with medium and high degrees of sulfur-functionalization, respectively, compared to carbon with no sulfur-functionalization. We attribute this significant improvement to the presence of covalently bound sulfur groups at the internal surface of the functionalized carbon providing efficient anchoring sites for catenation to the sulfur loaded into the pores of the carbons and provide experimental support for this in the form of results from cyclic voltammetry and X-ray photoelectron spectroscopy.

  9. Sulfur in human nutrition and applications in medicine.

    PubMed

    Parcell, Stephen

    2002-02-01

    Because the role of elemental sulfur in human nutrition has not been studied extensively, it is the purpose of this article to emphasize the importance of this element in humans and discuss the therapeutic applications of sulfur compounds in medicine. Sulfur is the sixth most abundant macromineral in breast milk and the third most abundant mineral based on percentage of total body weight. The sulfur-containing amino acids (SAAs) are methionine, cysteine, cystine, homocysteine, homocystine, and taurine. Dietary SAA analysis and protein supplementation may be indicated for vegan athletes, children, or patients with HIV, because of an increased risk for SAA deficiency in these groups. Methylsulfonylmethane (MSM), a volatile component in the sulfur cycle, is another source of sulfur found in the human diet. Increases in serum sulfate may explain some of the therapeutic effects of MSM, DMSO, and glucosamine sulfate. Organic sulfur, as SAAs, can be used to increase synthesis of S-adenosylmethionine (SAMe), glutathione (GSH), taurine, and N-acetylcysteine (NAC). MSM may be effective for the treatment of allergy, pain syndromes, athletic injuries, and bladder disorders. Other sulfur compounds such as SAMe, dimethylsulfoxide (DMSO), taurine, glucosamine or chondroitin sulfate, and reduced glutathione may also have clinical applications in the treatment of a number of conditions such as depression, fibromyalgia, arthritis, interstitial cystitis, athletic injuries, congestive heart failure, diabetes, cancer, and AIDS. Dosages, mechanisms of action, and rationales for use are discussed. The low toxicological profiles of these sulfur compounds, combined with promising therapeutic effects, warrant continued human clinical trails. PMID:11896744

  10. Instrumental methods of analysis of sulfur compounds in synfuel process streams. Quarterly technical progress report, October-December 1983

    SciTech Connect

    Jordan, J.; Sexton, E.; Talbott, J.; Yakupkovic, J.

    1984-01-01

    Task 1. Methods development for the speciation of the polysulfides. The contributions of this project to the electrochemical analysis of sulfides and polysulfides are reviewed and summarized. Electrochemical reduction at the dropping mercury electrode (DME) is the method of choice for the determination of polysulfidic sulfur. Total sulfidic sulfur can conveniently be quantitated in mixtures of sulfides and polysulfides, by measuring diffusion currents engendered by the anodic depolarization of the DME in the presence of the moieties HS/sup -/ and S/sub x//sup 2 -/. Task 2. Methods development for the speciation of dithionite and polythionates. In a solvent consisting of 40% ethanol-60% water, electrocapillary curves substantiated the adsorption of ethanol at the dropping mercury electrode. The potentials where adsorption occurred paralleled a shift of 1 volt in the polarographic half potential of the reaction: S/sub 4/O/sub 6//sup 2 -/ + 2e = 2S/sub 2/O/sub 3//sup 2 -/. Task 3. Total accounting of the sulfur balance in representative samples of synfuel process streams. Two H-Coal liquefaction sour water samples were analyzed representing different stages in the PETC clean-up procedures. One specimen was a sample stripped of H/sub 2/S and ammonia; the other, resulting from a different batch, was stripped and subsequently extracted with methyl isobutyl ketone. The stripped effluent contained less than 0.001 M concentrations of sulfide, polysulfide, thiosulfate, and sulfate. On the other hand, sulfate accounted for 90% of the total sulfur present in the stripped and extracted sample; the remainder consisted of sulfidic and polysulfidic sulfur as well as thiosulfate. 13 references, 2 figures, 3 tables.

  11. Identification, synthesis, and characterization of novel sulfur-containing volatile compounds from the in-depth analysis of Lisbon lemon peels (Citrus limon L. Burm. f. cv. Lisbon).

    PubMed

    Cannon, Robert J; Kazimierski, Arkadiusz; Curto, Nicole L; Li, Jing; Trinnaman, Laurence; Jańczuk, Adam J; Agyemang, David; Da Costa, Neil C; Chen, Michael Z

    2015-02-25

    Lemons (Citrus limon) are a desirable citrus fruit grown and used globally in a wide range of applications. The main constituents of this sour-tasting fruit have been well quantitated and characterized. However, additional research is still necessary to better understand the trace volatile compounds that may contribute to the overall aroma of the fruit. In this study, Lisbon lemons (C. limon L. Burm. f. cv. Lisbon) were purchased from a grove in California, USA, and extracted by liquid-liquid extraction. Fractionation and multidimensional gas chromatography-mass spectrometry were utilized to separate, focus, and enhance unidentified compounds. In addition, these methods were employed to more accurately assign flavor dilution factors by aroma extract dilution analysis. Numerous compounds were identified for the first time in lemons, including a series of branched aliphatic aldehydes and several novel sulfur-containing structures. Rarely reported in citrus peels, sulfur compounds are known to contribute significantly to the aroma profile of the fruit and were found to be aroma-active in this particular study on lemons. This paper discusses the identification, synthesis, and organoleptic properties of these novel volatile sulfur compounds. PMID:25639384

  12. Sulfur isotopic compositions of individual organosulfur compounds and their genetic links in the Lower Paleozoic petroleum pools of the Tarim Basin, NW China

    NASA Astrophysics Data System (ADS)

    Cai, Chunfang; Amrani, Alon; Worden, Richard H.; Xiao, Qilin; Wang, Tiankai; Gvirtzman, Zvi; Li, Hongxia; Said-Ahmad, Ward; Jia, Lianqi

    2016-06-01

    During thermochemical sulfate reduction (TSR), H2S generated by reactions between hydrocarbons and aqueous sulfate back-reacts with remaining oil-phase compounds forming new organosulfur compounds (OSCs) that have similar δ34S values to the original sulfate. Using Compound Specific Sulfur Isotope Analysis (CSSIA) of alkylthiaadamantanes (TAs), alkyldibenzothiophenes (DBTs), alkylbenzothiophenes (BTs) and alkylthiolanes (TLs), we have here attempted to differentiate OSCs due to primary generation and those due to TSR in oils from the Tarim Basin, China. These oils were generated from Cambrian source rocks and accumulated in Cambrian and Ordovician reservoirs. Based on compound specific sulfur isotope and carbon isotope data, TAs concentrations and DBT/phenanthrene ratios, the oils fall into four groups, reflecting different extents of source rock signal, alteration by TSR, mixing events, and secondary generation of H2S. Thermally stable TAs, that were produced following TSR, rapidly dominate kerogen-derived TAs at low to moderate degrees of TSR. Less thermally stable TLs and BTs were created as soon as TSR commenced, rapidly adopted TSR-δ34S values, but they do not survive at high concentrations unless TSR is advanced and ongoing. The presence of TLs and BTs shows that TSR is still active. Secondary DBTs were produced in significant amounts, sufficient to dominate kerogen-derived DBTs, only when TSR was at an advanced extent. The difference in sulfur isotopes between (i) TLs and DBTs and (ii) BTs and DBTs and (iii) TAs and DBTs, represents the extent of TSR while the presence of TAs at greater than 20 μg/g represents the occurrence of TSR. The output of this study shows that compound specific sulfur isotopes of different organosulfur compounds, with different thermal stabilities and formation pathways, not only differentiate between oils of TSR and non-TSR origin, but can also reveal information about relative timing of secondary charge events and migration pathways.

  13. Microbial Desulfurization of a Crude Oil Middle-Distillate Fraction: Analysis of the Extent of Sulfur Removal and the Effect of Removal on Remaining Sulfur

    PubMed Central

    Grossman, M. J.; Lee, M. K.; Prince, R. C.; Garrett, K. K.; George, G. N.; Pickering, I. J.

    1999-01-01

    Rhodococcus sp. strain ECRD-1 was evaluated for its ability to desulfurize a 232 to 343°C middle-distillate (diesel range) fraction of Oregon basin (OB) crude oil. OB oil was provided as the sole source of sulfur in batch cultures, and the extent of desulfurization and the chemical fate of the residual sulfur in the oil after treatment were determined. Gas chromatography (GC), flame ionization detection, and GC sulfur chemiluminesce detection analysis were used to qualitatively evaluate the effect of Rhodococcus sp. strain ECRD-1 treatment on the hydrocarbon and sulfur content of the oil, respectively. Total sulfur was determined by combustion of samples and measurement of released sulfur dioxide by infrared absorption. Up to 30% of the total sulfur in the middle distillate cut was removed, and compounds across the entire boiling range of the oil were affected. Sulfur K-edge X-ray absorption-edge spectroscopy was used to examine the chemical state of the sulfur remaining in the treated OB oil. Approximately equal amounts of thiophenic and sulfidic sulfur compounds were removed by ECRD-1 treatment, and over 50% of the sulfur remaining after treatment was in an oxidized form. The presence of partially oxidized sulfur compounds indicates that these compounds were en route to desulfurization. Overall, more than two-thirds of the sulfur had been removed or oxidized by the microbial treatment. PMID:9872778

  14. Formation of nitrogen- and sulfur-containing light-absorbing compounds accelerated by evaporation of water from secondary organic aerosols

    NASA Astrophysics Data System (ADS)

    Nguyen, Tran B.; Lee, Paula B.; Updyke, Katelyn M.; Bones, David L.; Laskin, Julia; Laskin, Alexander; Nizkorodov, Sergey A.

    2012-01-01

    Aqueous extracts of secondary organic aerosols (SOA) generated from the ozonolysis of d-limonene were subjected to dissolution, evaporation, and re-dissolution in the presence and absence of ammonium sulfate (AS). Evaporation with AS at pH 4-9 produced chromophores that were stable with respect to hydrolysis and had a distinctive absorption band at 500 nm. Evaporation accelerated the rate of chromophore formation by at least three orders of magnitude compared to the reaction in aqueous solution, which produced similar compounds. Absorption spectroscopy and high-resolution nanospray desorption electrospray ionization (nano-DESI) mass spectrometry experiments suggested that the molar fraction of the chromophores was small (<2%), and that they contained nitrogen atoms. Although the colored products represented only a small fraction of SOA, their large extinction coefficients (>105 L mol-1 cm-1 at 500 nm) increased the effective mass absorption coefficient of the residual organics in excess of 103 cm2 g-1 - a dramatic effect on the optical properties from minor constituents. Evaporation of SOA extracts in the absence of AS resulted in the production of colored compounds only when the SOA extract was acidified to pH ˜ 2 with sulfuric acid. These chromophores were produced by acid-catalyzed aldol condensation, followed by a conversion into organosulfates. The presence of organosulfates was confirmed by high resolution mass spectrometry experiments. Results of this study suggest that evaporation of cloud or fog droplets containing dissolved organics leads to significant modification of the molecular composition and serves as a potentially important source of light-absorbing compounds.

  15. Formation of Nitrogen- and Sulfur-Containing Light-Absorbing Compounds Accelerated by Evaporation of Water from Secondary Organic Aerosols

    SciTech Connect

    Nguyen, Tran B.; Lee, Paula B.; Updyke, Katelyn M.; Bones, David L.; Laskin, Julia; Laskin, Alexander; Nizkorodov, Sergey

    2012-01-14

    Aqueous extracts of secondary organic aerosols (SOA) generated from the ozonolysis of dlimonene were subjected to dissolution, evaporation, and re-dissolution in the presence and absence of ammonium sulfate (AS). Evaporation with AS at pH 4-9 produced chromophores that were stable with respect to hydrolysis and had a distinctive absorption band at 500 nm. Evaporation accelerated the rate of chromophore formation by at least three orders of magnitude compared to the reaction in aqueous solution, which produced similar compounds. Absorption spectroscopy and high-resolution nanospray desorption electrospray ionization (nano-DESI) mass spectrometry experiments suggested that the molar fraction of the chromophores was small (< 2%), and that they contained nitrogen atoms. Although the colored products represented only a small fraction of SOA, their large extinction coefficients (>10{sup 5} L mol{sup -1} cm{sup -1} at 500 nm) increased the effective mass absorption coefficient of the residual organics in excess of 10{sup 3} cm{sup 2} g{sup -1} - a dramatic effect on the optical properties from minor constituents. Evaporation of SOA extracts in the absence of AS resulted in the production of colored compounds only when the SOA extract was acidified to pH {approx} 2 with sulfuric acid. These chromophores were produced by acid-catalyzed aldol condensation, followed by a conversion into organosulfates. The presence of organosulfates was confirmed by high resolution mass spectrometry experiments. Results of this study suggest that evaporation of cloud or fog droplets containing dissolved organics leads to significant modification of the molecular composition and serves as a potentially important source of light-absorbing compounds.

  16. Effect of nitrogen supplementation and Saccharomyces species on hydrogen sulfide and other volatile sulfur compounds in shiraz fermentation and wine.

    PubMed

    Ugliano, Maurizio; Fedrizzi, Bruno; Siebert, Tracey; Travis, Brooke; Magno, Franco; Versini, Giuseppe; Henschke, Paul A

    2009-06-10

    A Shiraz must with low yeast assimilable nitrogen (YAN) was supplemented with two increasing concentrations of diammonium phosphate (DAP) and fermented with one Saccharomyces cerevisiae and one Saccharomyces bayanus strain, with maceration on grape skins. Hydrogen sulfide (H(2)S) was monitored throughout fermentation, and a total of 16 volatile sulfur compounds (VSCs) were quantified in the finished wines. For the S. cerevisiae yeast strain, addition of DAP to a final YAN of 250 or 400 mg/L resulted in an increased formation of H(2)S compared to nonsupplemented fermentations (100 mg/L YAN). For this yeast, DAP-supplemented fermentations also showed prolonged formation of H(2)S into the later stage of fermentation, which was associated with increased H(2)S in the final wines. The S. bayanus strain showed a different H(2)S production profile, in which production was inversely correlated to initial YAN. No correlation was found between total H(2)S produced by either yeast during fermentation and H(2)S concentration in the final wines. For both yeasts, DAP supplementation yielded higher concentrations of organic VSCs in the finished wines, including sulfides, disulfides, mercaptans, and mercaptoesters. PCA analysis indicated that nitrogen supplementation before fermentation determined a much clearer distinction between the VSC profiles of the two yeasts compared to nonsupplemented fermentations. These results raise questions concerning the widespread use of DAP in the management of low YAN fermentations with respect to the formation of reductive characters in wine. PMID:19391591

  17. The Oxidation of Sulfur-Containing Compounds Using Heterogeneous Catalysts of Transition Metal Oxides Deposited on the Polymeric Matrix

    NASA Astrophysics Data System (ADS)

    Dinh Vu, Ngo; Dinh Bui, Nhi; Thi Minh, Thao; Thi Thanh Dam, Huong; Thi Tran, Hang

    2016-05-01

    We investigate the activity of heterogeneous catalysts of transition metal oxides deposited on the polymeric matrix in the oxidation of sulfur-containing compounds. It is shown that MnO2-10/CuO-10 has the highest catalytic activity. The physicomechanical properties of polymeric heterogeneous catalysts of transition-metal oxides, including the specific surface area, elongation at break and breaking strength, specific electrical resistance, and volume resistivity were studied by using an Inspekt mini 3 kN universal tensile machine in accordance with TCVN 4509:2006 at a temperature of 20 ± 2°C. Results show that heterogeneous polymeric catalysts were stable under severe reaction conditions. Scanning electron microscopy, and energy-dispersive analysis are used to study the surfaces of the catalysts. Microstructural characterization of the catalysts is performed by using x-ray computed tomography. We demonstrate the potential application of polymeric heterogeneous catalysts of transition-metal oxides in industrial wastewater treatment.

  18. The Oxidation of Sulfur-Containing Compounds Using Heterogeneous Catalysts of Transition Metal Oxides Deposited on the Polymeric Matrix

    NASA Astrophysics Data System (ADS)

    Dinh Vu, Ngo; Dinh Bui, Nhi; Thi Minh, Thao; Thi Thanh Dam, Huong; Thi Tran, Hang

    2015-12-01

    We investigate the activity of heterogeneous catalysts of transition metal oxides deposited on the polymeric matrix in the oxidation of sulfur-containing compounds. It is shown that MnO2-10/CuO-10 has the highest catalytic activity. The physicomechanical properties of polymeric heterogeneous catalysts of transition-metal oxides, including the specific surface area, elongation at break and breaking strength, specific electrical resistance, and volume resistivity were studied by using an Inspekt mini 3 kN universal tensile machine in accordance with TCVN 4509:2006 at a temperature of 20 ± 2°C. Results show that heterogeneous polymeric catalysts were stable␣under severe reaction conditions. Scanning electron microscopy, and energy-dispersive analysis are used to study the surfaces of the catalysts. Microstructural characterization of the catalysts is performed by using x-ray computed tomography. We demonstrate the potential application of polymeric heterogeneous catalysts of transition-metal oxides in industrial wastewater treatment.

  19. Sulfur speciation of single aerosol particles

    SciTech Connect

    Neubauer, K.R.; Sum, S.T.; Johnston, M.V.; Wexler, A.S.

    1995-12-31

    Sulfur enters the atmosphere as gaseous species emitted from both natural and anthropogenic sources. These species can undergo a variety of oxidation reactions that ultimately yield hexavalent sulfur aerosols. Since the final products play an important role in acid rain production and the earth`s energy balance, it is important to distinguish tetravalent and hexavalent sulfur aerosols, as well as differentiate those arising from natural and anthropogenic sources. To attain these goals the authors chose to examine five target compounds that are present in the atmosphere: sodium sulfate, ammonium sulfate, ammonium sulfite, methanesulfonic acid (MSA), and the sodium salt of hydroxymethanesulfonic acid (NaHMSA). Sodium sulfate is observed in oceanic aerosols, while both ammonium salts are observed over land. MSA is found only in the marine environment and originates solely from natural emissions, while HMSA is formed in urban hazes and primarily arises from anthropogenic sources. Thus, MSA and HMSA serve as tracers for distinguishing natural and anthropogenic sulfur emissions. To differentiate these compounds, the authors used Rapid Single-Particle Mass Spectrometry (RSMS), a method that allows single particles to be analyzed on-line and in real time. With RSMS, particles are drawn directly into the source region of a reflectron time-of-flight mass spectrometer where they are detected by light scattering of a continuous laser beam and then ablated by an excimer laser pulse. With this sequence of events, each mass spectrum results from a single laser pulse ablating a single particle.

  20. Reduction mechanism of sulfur in lithium-sulfur battery: From elemental sulfur to polysulfide

    NASA Astrophysics Data System (ADS)

    Zheng, Dong; Zhang, Xuran; Wang, Jiankun; Qu, Deyu; Yang, Xiaoqing; Qu, Deyang

    2016-01-01

    The polysulfide ions formed during the first reduction wave of sulfur in Li-S battery were determined through both in-situ and ex-situ derivatization of polysulfides. By comparing the cyclic voltammetric results with and without the derivatization reagent (methyl triflate) as well as the in-situ and ex-situ derivatization results under potentiostatic condition, in-situ derivatization was found to be more appropriate than its ex-situ counterpart, since subsequent fast chemical reactions between the polysulfides and sulfur may occur during the timeframe of ex-situ procedures. It was found that the major polysulfide ions formed at the first reduction wave of elemental sulfur were the S4 2 - and S5 2 - species, while the widely accepted reduction products of S8 2 - and S6 2 - for the first reduction wave were in low abundance.

  1. The Speciation of Sulfur in an Ocean on Europa

    NASA Technical Reports Server (NTRS)

    Zolotov, M. Yu.; Shock, E. L.

    2002-01-01

    Stability of native sulfur, iron sulfides, and aqueous sulfur compounds is evaluated at assumed P-T conditions of the Europa's ocean floor. Pyrite, gypsum, and ferric hydroxides can coexist in contact with sulfate-rich oceanic water. Additional information is contained in the original extended abstract.

  2. PROTOTYPE CORRELATION MASK FLAME PHOTOMETRIC DETECTOR FOR MEASURING SULFUR DIOXIDE

    EPA Science Inventory

    A prototype flame photometric detector system (FPD) to measure gaseous sulfur compounds was fabricated using a previously developed correlation mask optical system and a new flame housing. Also, a new burner for the FPD system was optimized to view the excited molecular sulfur em...

  3. Behavior of sulfur during coal pyrolysis

    USGS Publications Warehouse

    Shao, D.; Hutchinson, E.J.; Heidbrink, J.; Pan, W.-P.; Chou, C.-L.

    1994-01-01

    The behavior of sulfur in Illinois coals during pyrolysis was evaluated by thermogravimetry/ Fourier transform-infrared spectroscopy (TG/FT-IR) techniques. SO2, COS, and H2S were major gaseous sulfur-containing products observed during coal pyrolysis. The release rates of the gaseous sulfur species showed several peaks within the temperature ranges, which were due to the emission of different forms of sulfur in coal. ?? 1994.

  4. Limits to Sulfur Accumulation in Transgenic Lupin Seeds Expressing a Foreign Sulfur-Rich Protein

    PubMed Central

    Tabe, Linda M.; Droux, Michel

    2002-01-01

    The low sulfur amino acid content of legume seeds restricts their nutritive value for animals. We have investigated the limitations to the accumulation of sulfur amino acids in the storage proteins of narrow leaf lupin (Lupinus angustifolius) seeds. Variation in sulfur supply to lupin plants affected the sulfur amino acid accumulation in the mature seed. However, when sulfur was in abundant supply, it accumulated to a large extent in oxidized form, rather than reduced form, in the seeds. At all but severely limiting sulfur supply, addition of a transgenic (Tg) sink for organic sulfur resulted in an increase in seed sulfur amino acid content. We hypothesize that demand, or sink strength for organic sulfur, which is itself responsive to environmental sulfur supply, was the first limit to the methionine (Met) and cysteine (Cys) content of wild-type lupin seed protein under most growing conditions. In Tg, soil-grown seeds expressing a foreign Met- and Cys-rich protein, decreased pools of free Met, free Cys, and glutathione indicated that the rate of synthesis of sulfur amino acids in the cotyledon had become limiting. Homeostatic mechanisms similar to those mediating the responses of plants to environmental sulfur stress resulted in an adjustment of endogenous protein composition in Tg seeds, even when grown at adequate sulfur supply. Uptake of sulfur by lupin cotyledons, as indicated by total seed sulfur at maturity, responded positively to increased sulfur supply, but not to increased demand in the Tg seeds. PMID:11891268

  5. Sulfur Dioxide and Material Damage

    ERIC Educational Resources Information Center

    Gillette, Donald G.

    1975-01-01

    This study relates sulfur dioxide levels with material damage in heavily populated or polluted areas. Estimates of loss were determined from increased maintenance and replacement costs. The data indicate a decrease in losses during the past five years probably due to decline in pollution levels established by air quality standards. (MR)

  6. SULFUR DIOXIDE SOURCES IN AK

    EPA Science Inventory

    This map shows industrial plants which emit 100 tons/year or more of sulfur dioxide (SO2) in Alaska. The SO2 sources are plotted on a background map of cities and county boundaries. Data Sources: SO2 Sites: U.S. EPA AIRS System, County Outlines: 1990 Census Tiger Line Files 1:1...

  7. Sulfur hexafluoride as a surrogate

    SciTech Connect

    Taylor, P.H.; Chadbourne, J.F.

    1987-06-01

    A viable chemical surrogate for monitoring the effectiveness of hazardous waste incinerators must include high thermal stability and low toxicity among its characteristics. The relationship between sulfur hexafluoride (SF6) and hazardous constituent thermal stability for a mixture of chlorinated hydrocarbons indicates that SF6 has the potential to satisfy the basic requirements of a chemical surrogate for hazardous waste incineration.

  8. TRENDS IN RURAL SULFUR CONCENTRATIONS

    EPA Science Inventory

    This paper presents an analysis of regional trends in atmospheric concentrations in sulfur dioxide (502) and particulate sulfate (50~- ) at rural monitoring sites in the Clean Air Act Status and Trends Monitoring Network (CAsTNet) from 1990 to 1999. A two-stage approach is used t...

  9. Nutrient cyling in soils: Sulfur

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sulfur (S) is an essential element required for normal plant growth, a fact that has been recognized since the nineteenth century. It is considered a secondary macronutrient, following the primary macronutrients nitrogen (N), phosphorus (P), and potassium (K), but is needed by plants at levels compa...

  10. Biochemistry of dissimilatory sulfur oxidation

    SciTech Connect

    Blake, R. II.

    1992-01-01

    Our goals of this research are to define the substrate oxidation pathways, the electron transport mechanisms, and the modes of energy conservation employed during the dissimilatory oxidation of sulfur by thiobacilli. We have purified APS reductase to electrophoratic homogeneity from cell-free extracts of Thiobacillus denitrificans. Sufficient protein is available to initiate the production of polyclonal antibodies and to perform the kinetic experiments.

  11. Seal for sodium sulfur battery

    DOEpatents

    Topouzian, Armenag; Minck, Robert W.; Williams, William J.

    1980-01-01

    This invention is directed to a seal for a sodium sulfur battery in which the sealing is accomplished by a radial compression seal made on a ceramic component of the battery which separates an anode compartment from a cathode compartment of the battery.

  12. Recovering sulfur from gas streams

    SciTech Connect

    1997-11-01

    Linde AG (Hoellriegeiskreuth, Germany) has developed ClinSulf-SDP process, a two-reactor system that offers better than 99.5% sulfur recovery at low capital and operating costs. In a traditional Claus plant, sulfur-recovery rates of 99.3% can be achieved by combining a two- or three-stage Claus plant with a separate tail-gas cleanup unit (TGCU). Common TGCU methods include H{sub 2}S scrubbing, subdewpoint condensation and direct oxidation. Such combined units are not only costly and complicated to build and maintain, but many of today`s operators require higher sulfur-recovery rates--on the order of 99.3%--99.8%. The Clin-Sulf-SDP combines several catalytic stages of a Claus plant with a subdewpoint, tailgas-treatment system, and the process uses only two reactors. At the heart of the process are two identical, internally cooled reactors. Two four-way valves periodically reverse the sequence of the matching reactors, allowing them to alternate between sulfur-adsorption and catalyst-regeneration modes.

  13. 21 CFR 182.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sulfur dioxide. 182.3862 Section 182.3862 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 182.3862 Sulfur dioxide. (a) Product. Sulfur dioxide. (b) (c) Limitations, restrictions, or explanation. This substance...

  14. 21 CFR 582.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sulfur dioxide. 582.3862 Section 582.3862 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... Sulfur dioxide. (a) Product. Sulfur dioxide. (b) (c) Limitations, restrictions, or explanation....

  15. 21 CFR 182.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sulfur dioxide. 182.3862 Section 182.3862 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 182.3862 Sulfur dioxide. (a) Product. Sulfur dioxide. (b) (c) Limitations, restrictions, or explanation. This substance...

  16. 21 CFR 582.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sulfur dioxide. 582.3862 Section 582.3862 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... Sulfur dioxide. (a) Product. Sulfur dioxide. (b) (c) Limitations, restrictions, or explanation....

  17. Air Quality Criteria for Sulfur Oxides.

    ERIC Educational Resources Information Center

    National Air Pollution Control Administration (DHEW), Washington, DC.

    Included is a literature review which comprehensively discusses knowledge of the sulfur oxides commonly found in the atmosphere. The subject content is represented by the 10 chapter titles: Physical and Chemical Properties and the Atmospheric Reactions of the Oxides of Sulfur; Sources and Methods of Measurements of Sulfur Oxides in the Atmosphere;…

  18. Genetic engineering of sulfur-degrading Sulfolobus

    SciTech Connect

    Ho, N.W.Y.

    1991-01-01

    The objectives of the proposed research is to first establish a plasmid-mediated genetic transformation system for the sulfur degrading Sulfolobus, and then to clone and overexpress the genes encoding the organic-sulfur-degrading enzymes from Sulfolobus- as well as from other microorganisms, to develop a Sulfolobus-based microbial process for the removal of both organic and inorganic sulfur from coal.

  19. 21 CFR 182.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sulfur dioxide. 182.3862 Section 182.3862 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 182.3862 Sulfur dioxide. (a) Product. Sulfur dioxide. (b) (c) Limitations, restrictions, or explanation. This substance...

  20. 21 CFR 582.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sulfur dioxide. 582.3862 Section 582.3862 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... Sulfur dioxide. (a) Product. Sulfur dioxide. (b) (c) Limitations, restrictions, or explanation....

  1. 21 CFR 582.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sulfur dioxide. 582.3862 Section 582.3862 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... Sulfur dioxide. (a) Product. Sulfur dioxide. (b) (c) Limitations, restrictions, or explanation....

  2. 21 CFR 182.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sulfur dioxide. 182.3862 Section 182.3862 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 182.3862 Sulfur dioxide. (a) Product. Sulfur dioxide. (b) (c) Limitations, restrictions, or explanation. This substance...

  3. 21 CFR 182.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sulfur dioxide. 182.3862 Section 182.3862 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 182.3862 Sulfur dioxide. (a) Product. Sulfur...

  4. 21 CFR 582.3862 - Sulfur dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Sulfur dioxide. 582.3862 Section 582.3862 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... Sulfur dioxide. (a) Product. Sulfur dioxide. (b) (c) Limitations, restrictions, or explanation....

  5. 46 CFR 153.1046 - Sulfuric acid.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Sulfuric acid. 153.1046 Section 153.1046 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK....1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external...

  6. 21 CFR 582.1095 - Sulfuric acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sulfuric acid. 582.1095 Section 582.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1095 Sulfuric acid. (a) Product. Sulfuric acid. (b) Conditions of use. This substance is...

  7. 21 CFR 184.1095 - Sulfuric acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sulfuric acid. 184.1095 Section 184.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1095 Sulfuric acid. (a) Sulfuric acid (H2SO4, CAS Reg. No. 7664-93-9),...

  8. 46 CFR 153.1046 - Sulfuric acid.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Sulfuric acid. 153.1046 Section 153.1046 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK....1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external...

  9. 46 CFR 153.1046 - Sulfuric acid.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Sulfuric acid. 153.1046 Section 153.1046 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK....1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external...

  10. 21 CFR 184.1095 - Sulfuric acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sulfuric acid. 184.1095 Section 184.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT FOOD....1095 Sulfuric acid. (a) Sulfuric acid (H2SO4, CAS Reg. No. 7664-93-9), also known as oil of vitriol,...

  11. 46 CFR 153.1046 - Sulfuric acid.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Sulfuric acid. 153.1046 Section 153.1046 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK....1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external...

  12. SULFUR ASSIMILATION IN PLANTS AND WEED CONTROL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sulfur is an indispensable element for plants. It is found in sulfur-containing amino acids, cysteine and methionine, and in various other important biochemical components and processes. Inhibitors of sulfur assimilation, or cysteine and methionine synthesis, could be potential herbicides. The sulf...

  13. 21 CFR 184.1095 - Sulfuric acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sulfuric acid. 184.1095 Section 184.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1095 Sulfuric acid. (a) Sulfuric acid (H2SO4, CAS Reg. No. 7664-93-9),...

  14. 21 CFR 582.1095 - Sulfuric acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sulfuric acid. 582.1095 Section 582.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1095 Sulfuric acid. (a) Product. Sulfuric acid. (b) Conditions of use. This substance is...

  15. 21 CFR 582.1095 - Sulfuric acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sulfuric acid. 582.1095 Section 582.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1095 Sulfuric acid. (a) Product. Sulfuric acid. (b) Conditions of use. This substance is...

  16. Protective effects of the thiol compounds GSH and NAC against sulfur mustard toxicity in a human keratinocyte cell line.

    PubMed

    Balszuweit, Frank; Menacher, Georg; Schmidt, Annette; Kehe, Kai; Popp, Tanja; Worek, Franz; Thiermann, Horst; Steinritz, Dirk

    2016-02-26

    Sulfur mustard (SM) is a chemical warfare agent causing blistering, inflammation and ulceration of the skin. Thiol compounds such as glutathione (GSH) and N-acetylcysteine (NAC) have been suggested as potential antidotes. We investigated SM toxicity in a human keratinocyte cell line (HaCaT) and used GSH and NAC to counteract its cytotoxic effects. Cells were treated with 1, 5 or 10mM GSH or NAC and exposed to 30, 100 or 300μM SM. Different treatment regimens were applied to model extra- and intra-cellular GSH/NAC effects on SM toxicity. Necrosis, apoptosis and interleukin-6 and -8 levels were determined 24h post-exposure. Necrosis and apoptosis increased with SM dose. Interleukin-6 and -8 production peaked at 100μM and decreased at 300μM probably due to reduced ability for interleukin biosynthesis. Intracellular GSH/NAC diminished necrosis induced by 100μM SM. Extracellular GSH/NAC protected against necrosis and apoptosis induced by 100 and 300μM SM. Interleukin-6 and -8 production, induced by 100μM SM was reduced by GSH/NAC. However, low-dose GSH/NAC treatment of cells exposed to 300μM SM led to increased interleukin production. Thus, moderately poisoned cells are mostly responsible for SM-induced secretion of pro-inflammatory cytokines. GSH and NAC treatment can reduce SM-induced toxic effects. Protective effects were more pronounced by extracellular GSH or NAC administration. Rescue of severely poisoned cells may result in a strong secretion of pro- inflammatory cytokines. In summary, thiol compounds such as GSH or NAC constitute a promising approach to improve the therapy for SM injury. Additional intervention to prevent adverse effects of interleukin production might be beneficial. PMID:26361990

  17. A SAW-based chemical sensor for detecting sulfur-containing organophosphorus compounds using a two-step self-assembly and molecular imprinting technology.

    PubMed

    Pan, Yong; Yang, Liu; Mu, Ning; Shao, Shengyu; Wang, Wen; Xie, Xiao; He, Shitang

    2014-01-01

    This paper presents a new effective approach for the sensitive film deposition of surface acoustic wave (SAW) chemical sensors for detecting organophosphorus compounds such as O-ethyl-S-2-diisopropylaminoethyl methylphosphonothiolate (VX) containing sulfur at extremely low concentrations. To improve the adsorptive efficiency, a two-step technology is proposed for the sensitive film preparation on the SAW delay line utilizing gold electrodes. First, mono[6-deoxy-6-[(mercaptodecamethylene)thio

  18. A SAW-Based Chemical Sensor for Detecting Sulfur-Containing Organophosphorus Compounds Using a Two-Step Self-Assembly and Molecular Imprinting Technology

    PubMed Central

    Pan, Yong; Yang, Liu; Mu, Ning; Shao, Shengyu; Wang, Wen; Xie, Xiao; He, Shitang

    2014-01-01

    This paper presents a new effective approach for the sensitive film deposition of surface acoustic wave (SAW) chemical sensors for detecting organophosphorus compounds such as O-ethyl-S-2-diisopropylaminoethyl methylphosphonothiolate (VX) containing sulfur at extremely low concentrations. To improve the adsorptive efficiency, a two-step technology is proposed for the sensitive film preparation on the SAW delay line utilizing gold electrodes. First, mono[6-deoxy-6-[(mercaptodecamethylene)thio

  19. Wet Chemistry Synthesis of Multidimensional Nanocarbon-Sulfur Hybrid Materials with Ultrahigh Sulfur Loading for Lithium-Sulfur Batteries.

    PubMed

    Du, Wen-Cheng; Yin, Ya-Xia; Zeng, Xian-Xiang; Shi, Ji-Lei; Zhang, Shuai-Feng; Wan, Li-Jun; Guo, Yu-Guo

    2016-02-17

    An optimized nanocarbon-sulfur cathode material with ultrahigh sulfur loading of up to 90 wt % is realized in the form of sulfur nanolayer-coated three-dimensional (3D) conducting network. This 3D nanocarbon-sulfur network combines three different nanocarbons, as follows: zero-dimensional carbon nanoparticle, one-dimensional carbon nanotube, and two-dimensional graphene. This 3D nanocarbon-sulfur network is synthesized by using a method based on soluble chemistry of elemental sulfur and three types of nanocarbons in well-chosen solvents. The resultant sulfur-carbon material shows a high specific capacity of 1115 mA h g(-1) at 0.02C and good rate performance of 551 mA h g(-1) at 1C based on the mass of sulfur-carbon composite. Good battery performance can be attributed to the homogeneous compositing of sulfur with the 3D hierarchical hybrid nanocarbon networks at nanometer scale, which provides efficient multidimensional transport pathways for electrons and ions. Wet chemical method developed here provides an easy and cost-effective way to prepare sulfur-carbon cathode materials with high sulfur loading for application in high-energy Li-S batteries. PMID:26378622

  20. Changing Electric Resistance of ZnO Nano-Rods by Sulfur Compounds for Chemical Gas Sensor.

    PubMed

    Park, No-Kuk; Lee, Tae Hoon; Choi, Hee Young; Lee, Tae Jin

    2015-02-01

    In this study, a zinc oxide (ZnO) single crystal rod was synthesized for applications as a gas-sensing material for hydrogen sulfide (H2S) and its H2S-sensing properties were investigated. H2S absorbed well on ZnO via a gas and solid chemical reaction, resulting in the conversion of ZnO to ZnS. ZnS is also oxidized easily to ZnO with O2 contained in air. ZnO and ZnS are semiconducting materials. The energy band gap of ZnS is higher than that of ZnO. Therefore, the electric conductivity of ZnS must be lower than that of ZnO. On the other hand, different results were obtained in the H2S sensing tests. The energy band gap of sulfur-absorbed ZnO nano-rods was 2.84 eV according to UV-Visible spectrophotometry. The electrical conductivity can be enhanced by sulfur doping on ZnO single crystal rods because the lattice oxygen on the surface of ZnO single crystal is replaced with the sulfur in H2S. The electrical conductivity of S-doped ZnO also decreased due to oxidation with the oxygen in air. PMID:26353726

  1. Process of decreasing the sulfur content of exhaust gases obtained during the recovery of sulfur

    SciTech Connect

    Schlauer, J.; Fischer, H.; Kriebel, M.

    1983-09-20

    In a process of decreasing the sulfur content of exhaust gases obtained during the recovery of sulfur from acid gases containing H/sub 2/S and other S-containing compounds in the Claus process, the acid gases which contain H/sub 2/S and other S-containing compounds are reacted in a Claus plant to form elemental sulfur. A gas which contains H/sub 2/S or SO/sub 2/ is subsequently added at a controlled rate to maintain a stoichiometric ratio of 2:1 of H/sub 2/S to SO/sub 2/ in the tail gas from the Claus plant. The gas which contains H/sub 2/S or SO/sub 2/ may be added to the tail gas from the Claus plant or before the last contacting stage of a multistage Claus plant. During the addition of a gas which contains H /sup 2/S the Claus plant can be operated at an H/sub 2/S to SO/sub 2/ ratio of or below 2:1. During the addition gas which contains SO/sub 2/ the Claus plant can be operated at an H/sub 2/S to SO/sub 2/ ratio of or above 2:1. The H/sub 2/ and SO/sub 2/ contained in the tail gas are chemically reacted to form elementary sulfur in a tail gas-desulfurizing plant and the sulfur is withdrawn.

  2. Genomics of alternative sulfur utilization in ascomycetous yeasts.

    PubMed

    Linder, Tomas

    2012-10-01

    Thirteen ascomycetous yeast strains with sequenced genomes were assayed for their ability to grow on chemically defined medium with 16 different sulfur compounds as the only significant source of sulfur. These compounds included sulfoxides, sulfones, sulfonates, sulfamates and sulfate esters. Broad utilization of alternative sulfur sources was observed in Komagataella pastoris (syn. Pichia pastoris), Lodderomyces elongisporus, Millerozyma farinosa (syn. Pichia sorbitophila), Pachysolen tannophilus, Scheffersomyces stipitis (syn. Pichia stipitis), Spathaspora passalidarum, Yamadazyma tenuis (syn. Candida tenuis) and Yarrowia lipolytica. Kluyveromyces lactis, Saccharomyces cerevisiae and Zygosaccharomyces rouxii were mainly able to utilize sulfonates and sulfate esters, while Lachancea thermotolerans and Schizosaccharomyces pombe were limited to aromatic sulfate esters. Genome analysis identified several candidate genes with bacterial homologues that had been previously shown to be involved in the utilization of alternative sulfur sources. Analysis of candidate gene promoter sequences revealed a significant overrepresentation of DNA motifs that have been shown to regulate sulfur metabolism in Sacc. cerevisiae. PMID:22790398

  3. INDUSTRIAL PROCESS PROFILES FOR ENVIRONMENTAL USE: CHAPTER 23. SULFUR, SULFUR OXIDES AND SULFURIC ACID

    EPA Science Inventory

    The catalog of Industrial Process Profiles for Environmental Use was developed as an aid in defining the environmental impacts of industrial activity in the United States. Entries for each industry are in consistent format and form separate chapters of the study. The sulfur indus...

  4. Petroleum and diesel sulfur degradation under gamma radiation

    NASA Astrophysics Data System (ADS)

    Andrade, Luana dos Santos; Calvo, Wilson Aparecido Parejo; Sato, Ivone Mulako; Duarte, Celina Lopes

    2015-10-01

    Hydrodesulfurization (HDS) is currently the most common method used by refineries to remove sulfur compounds from petroleum fractions. However, it is not highly effective for removing thiophene compounds such as benzothiophene. Additionally, this process generates high costs for the oil industry. In the present work, ionizing radiation was used in order to study the effect on the degradation of petroleum and diesel sulfur compounds. Crude oil and diesel fuel samples were studied, without any pretreatment, and irradiated using a cobalt-60 gamma cell in a batch system at absorbed doses of 30 kGy and 50 kGy. The sulfur compounds were extracted and then analyzed by gas chromatography associated with mass spectrometry (GCMS). A high efficiency of ionizing radiation was observed regarding the degradation of sulfur compounds such as benzothiophene and benzenethiol and the formation of fragments, for example 1.2-dimethylbenzene and toluene.

  5. New cysteine-S-conjugate precursors of volatile sulfur compounds in bell peppers (Capsicum annuum L. cultivar).

    PubMed

    Starkenmann, Christian; Niclass, Yvan

    2011-04-13

    The objective of this study was to verify whether the volatile organic sulfur compounds recently discovered in bell pepper (Capsicum annuum, L. cultivars), such as the mercapto-ketones: 4-sulfanyl-2-heptanone and 2-sulfanyl-4-heptanone, the mercapto-alcohols: 4-sulfanyl-2-heptanol and 2-sulfanyl-4-heptanol, and heptane-2,4-dithiol, originate from their corresponding cysteine-S-conjugates. Analysis of aqueous extracts of red and green bell pepper by ultraperformance liquid chromatography-mass spectrometry with electrospray ionization in the positive mode (UPLC-MS ESI(+)) displayed masses corresponding to the expected cysteine-S-conjugates. To confirm this observation, four cysteine-S-conjugates were prepared as authentic samples: S-(3-hydroxy-1-methylhexyl)-L-cysteine, S-(3-hydroxy-1-propylbutyl)-L-cysteine, S-(3-oxo-1-propylbutyl)-L-cysteine, and (2R,2'R)-3,3'-(4-hydroxyheptane-2,6-diyl)bis(sulfanediyl) bis(2-aminopropanoic acid). By comparison with the fragmentation patterns and retention times of synthetic mixtures of cysteine-S-conjugate diastereoisomers, the natural occurrence of cysteine conjugates was confirmed in bell peppers. In addition, the cysteine-S-conjugates from red and green bell pepper extracts were concentrated by ion exchange chromatography and the fractions incubated with a β-lyase (apotryptophanase). The liberated thiols were concentrated by affinity chromatography, and their occurrence, detected by gas chromatography-mass spectrometry, confirmed our predictions. Moreover, 3-sulfanyl-1-hexanol was also detected and the occurrence of S-(1(2-hydroxyethyl)butyl)-L-cysteine confirmed. A quantitative estimation based on external calibration curves, established by UPLC-MS ESI(+) in selected reaction monitoring mode, showed that cysteine-S-conjugates were present at concentrations in the range of 1 to 100 μg/kg (±20%). PMID:21375341

  6. Microbial populations analysis and field application of biofilter for the removal of volatile-sulfur compounds from swine wastewater treatment system.

    PubMed

    Ho, Kuo-Ling; Chung, Ying-Chien; Lin, Yueh-Hsien; Tseng, Ching-Ping

    2008-04-01

    A biofilter packed with granular activated carbon (GAC) was applied to eliminate volatile-sulfur compounds (VSC) emitted from solid-liquid separation tank in swine wastewater treatment system. Hydrogen sulfide, methanethiol, dimethyl disulfide, and dimethyl sulfide were effectively reduced to 96-100% at gas residence times of 13-30s. Elemental sulfur and sulfate are their primary oxidation metabolites. Regarding odor, an average of 86% reduction was achieved at short residence time (13s). In addition, bioaerosol emissions could also be effectively reduced by 90% with the biofilter. Advantages of the system include low moisture demand, low pressure drop, and high biofilm stability. Further characterization of bacterial populations of the activated carbon samples using the fluorescent in situ hybridization (FISH) technique revealed that Pseudomonas sp. remained the predominant community (56-70%) after long-term evaluation of 415 days. PMID:17709180

  7. Method for removing sulfur oxide from waste gases and recovering elemental sulfur

    DOEpatents

    Moore, Raymond H.

    1977-01-01

    A continuous catalytic fused salt extraction process is described for removing sulfur oxides from gaseous streams. The gaseous stream is contacted with a molten potassium sulfate salt mixture having a dissolved catalyst to oxidize sulfur dioxide to sulfur trioxide and molten potassium normal sulfate to solvate the sulfur trioxide to remove the sulfur trioxide from the gaseous stream. A portion of the sulfur trioxide loaded salt mixture is then dissociated to produce sulfur trioxide gas and thereby regenerate potassium normal sulfate. The evolved sulfur trioxide is reacted with hydrogen sulfide as in a Claus reactor to produce elemental sulfur. The process may be advantageously used to clean waste stack gas from industrial plants, such as copper smelters, where a supply of hydrogen sulfide is readily available.

  8. Sulfur diagenesis in everglades peat and origin of pyrite in coal

    USGS Publications Warehouse

    Altschuler, Z.S.; Schnepfe, M.M.; Silber, C.C.; Simon, F.O.

    1983-01-01

    The pattern of sulfur transformation in peat across the Everglades basin indicates that pyrite formation in organic-rich swamps depends on the use of organic oxysulfur compounds in dissimilatory respiration by sulfur-reducing bacteria. This paragenesis explains the primary distribution of sulfur compounds in low-sulfur coals and possibly in most coals and many organic-rich soils and sediments. It also accounts for the occurrence of framboidal pyrite bound in fossil tissue in coal and sediments.

  9. ROLE OF SULFUR IN REDUCING PCDD AND PCDF FORMATION

    EPA Science Inventory

    Past research has suggested that the presence of sulfur (S) in municipal waste combustors (MWCs) can decrease downstream formation of chlorinated organic compounds, particularly polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Thus, co-firing a...

  10. [Sulfur isotopic ratios indicating sulfur cycling in slope soils of karst areas].

    PubMed

    Zhang, Wei; Liu, Cong-qiang; Li, Xiao-dong; Liu, Tao-ze; Zhang, Li-li

    2010-02-01

    Sequential extraction methods for soil sulfur were used to determine delta34 S ratios and sulfur contents of total sulfur, organic sulfur, SO4(21) and FeS2 in slope soils of karst areas. In general, FeS2 has the lowest delta34 S ratios, ranging from -6.86% per hundred to -4.229% per hundred, followed in ascending order by SO4(2-) (-2.64% per hundred - -1.34% per hundred), total sulfur (-3.25% per hundred - -1.03% per hundred) and organic sulfur (-1.63% per hundred -0.50% per hundred) in surface soils of profiles, and delta34 S ratios in different sulfur forms all show increasing trend with profiles deepening. Covariations of delta34 S ratios of SO4(2-) and FeS2 with increasing depth are related to SO4(2-) dissimilatory reduction, while the increase in parallel of delta34 S ratios of total sulfur and organic sulfur could be resulted from organic sulfur cycling. delta34 S ratios have been extensively used to indicate sulfur sources, moreover, SO4(2-) dissimilatory reduction and organic sulfur mineralization result in significant sulfur isotopic fractionation, and sulfides oxidation and SO4(2-) assimilation have no isotopic fractionation occurred, the vertical variations of delta34 S ratios in different sulfur forms can therefore be good records for depth-dependant sulfur cycling processes. Furthermore, by comparing depth distributions of sulfur contents and delta34 S ratios in different sulfur forms, it is easily to discuss the migration of SO4(-1) and organic sulfur fractions in soil profiles. PMID:20391712

  11. Metal-sulfur type cell having improved positive electrode

    DOEpatents

    DeJonghe, L.C.; Visco, S.J.; Mailhe, C.C.; Armand, M.B.

    1988-03-31

    A novel metal-sulfur type cell operable at a temperature of 200/degree/C or less with an energy density of 150 Whrs/Kg or better is disclosed characterized by an organo-sulfur cathode formed from an organic-sulfur compound having the general formula, in its charged state, of (R(S)/sub y/)n wherein y = 1 to 6; n = 2 to 20; and R is one or more different aliphatic or aromatic organic moieties having 1 to 20 carbon atoms, which may include one or more oxygen, sulfur, or nitrogen heteroatoms when R comprises one or more aromatic rings, or one or more oxygen, sulfur, nitrogen, or fluorine atoms associated with the chain when R comprises an aliphatic chain, wherein the aliphatic group may be linear or branched, saturated or unsaturated, and wherein either the aliphatic chain or the aromatic ring may have substituted groups thereon. 4 figs.

  12. Metal-sulfur type cell having improved positive electrode

    DOEpatents

    Dejonghe, Lutgard C.; Visco, Steven J.; Mailhe, Catherine C.; Armand, Michel B.

    1989-01-01

    An novel metal-sulfur type cell operable at a temperature of 200.degree. C. or less with an energy density of 150 Whrs/Kg or better is disclosed characterized by an organo-sulfur cathode formed from an organic-sulfur compound having the general formula, in its charged state, of (R(S).sub.y).sub.n wherein y=1 to 6; n=2 to 20; and R is one or more different aliphatic or aromatic organic moieties having 1 to 20 carbon atoms, which may include one or more oxygen, sulfur, or nitrogen heteroatoms when R comprisises one of more aromatic rings, or one or more oxygen, sulfur, nitrogen, or fluorine atoms associtated with the chain when R comprises an aliphatic chain, wherein the aliphatic group may be linear or branched, saturated or unsaturated, and wherein either the aliphatic chain or the aromatic ring may have substituted groups thereon.

  13. Comparison between pre-fractionation and fractionation process of heavy gas oil for determination of sulfur compounds using comprehensive two-dimensional gas chromatography.

    PubMed

    Machado, Maria Elisabete; Bregles, Lucas Panizzi; de Menezes, Eliana Weber; Caramão, Elina Bastos; Benvenutti, Edilson Valmir; Zini, Cláudia Alcaraz

    2013-01-25

    The separation of the organic sulfur compounds (OSC) of petroleum or its heavy fractions is a critical step and is essential for the correct characterization of these compounds, especially due to similar physical and chemical properties of polycyclic aromatic sulfur heterocycles (PASH) and polycyclic aromatic hydrocarbons (PAH). This similarity results in coelutions among PAH and PASH and for this reason former steps of fractionation are required before gas chromatographic analysis. The objective of this study was to evaluate the potential of GC×GC for the separation and identification of OSC in a heavy gas oil sample without fractionation, after pre-fractionation in an alumina column and also after fractionation process. This last one was performed with a modified stationary phase manufactured and characterized in the laboratory, called Pd(II)-MPSG, where palladium is chemically linked to silica through mercaptopropyl groups. The fractions obtained from both procedures were analyzed by GC×GC/TOFMS, which was effective to separate and identify various classes of OSC. A hundred and thirty-five compounds were tentatively identified in the sample that was only pre-fractionated. However, when the fractionation was also performed with the Pd(II)-MPSG phase, a larger number of sulfur compounds were found (317). Results have shown that the analysis of a pre-fractionated sample by GC×GC/TOFMS is suitable when the goal is a general characterization of classes of compounds in the sample, while a more detailed analysis of PASH can be performed, using also the fractionation Pd(II)-MPSG phase. GC×GC/TOFMS played a major role in the comparison of samples obtained from pre-fractionation and fractionation steps due to its high peak capacity, selectivity, organized distribution of chromatographic peaks and resolution. PMID:23298843

  14. Reduction mechanism of sulfur in lithium-sulfur battery: From elemental sulfur to polysulfide

    DOE PAGESBeta

    Zheng, Dong; Yang, Xuran; Zhang, Xiaoqing; Wang, Jiankun; Qu, Deyu; Qu, Deyang

    2015-10-30

    In this study, the polysulfide ions formed during the first reduction wave of sulfur in Li–S battery were determined through both in-situ and ex-situ derivatization of polysulfides. By comparing the cyclic voltammetric results with and without the derivatization reagent (methyl triflate) as well as the in-situ and ex-situ derivatization results under potentiostatic condition, in-situ derivatization was found to be more appropriate than its ex-situ counterpart, since subsequent fast chemical reactions between the polysulfides and sulfur may occur during the timeframe of ex-situ procedures. It was found that the major polysulfide ions formed at the first reduction wave of elemental sulfurmore » were the S42– and S52– species, while the widely accepted reduction products of S82– and S62– for the first reduction wave were in low abundance.« less

  15. Biotic and abiotic carbon to sulfur bond cleavage. Final report

    SciTech Connect

    Frost, J.W.

    1994-05-01

    The microbial desulfurization of organosulfur compounds occurs by unprecedented and largely unexplored biochemical processes. A study of such biotic desulfurizations can be expected to give rise to new and useful chemistry and enzymology. The potential value of understanding and harnessing these processes is seen in relation to the need for methods for the removal of organically bound sulfur from coal and the degradation of organic sulfur-containing pollutants. This research effort has been directed towards an examination of desulfurization ability in well characterized microorganisms, the isolation of bacteria with desulfurization ability from natural sources, the characterization and mechanistic evaluation of the observed biocatalytic processes, the development of biomimetic synthetic organic chemistry based on biotic desulfurization mechanisms and the design and preparation of improved coal model compounds for use in microbial selection processes. A systematic approach to studying biodesulfurizations was undertaken in which organosulfur compounds have been broken down into classes based on the oxidation state of the sulfur atom and the structure of the rest of the organic material. Microbes have been evaluated in terms of ability to degrade organosulfur compounds with sulfur in its sulfonic acid oxidation state. These compounds are likely intermediates in coal desulfurization and are present in the environment as persistent pollutants in the form of detergents. It is known that oxygen bonded to sulfur lowers the carbon-sulfur bond energy, providing a thermodynamic basis for starting with this class of compounds.

  16. Radiolysis of Sulfuric Acid, Sulfuric Acid Monohydrate, and Sulfuric Acid Tetrahydrate and Its Relevance to Europa

    NASA Technical Reports Server (NTRS)

    Loeffler, M. J.; Hudson, R. L.; Moore, M. H.; Carlson, R. W.

    2011-01-01

    We report laboratory studies on the 0.8 MeV proton irradiation of ices composed of sulfuric acid (H2SO4), sulfuric acid monohydrate (H2SO4 H2O), and sulfuric acid tetrahydrate (H2SO4 4H2O) between 10 and 180 K. Using infrared spectroscopy, we identify the main radiation products as H2O, SO2, (S2O3)x, H3O+, HSO4(exp -), and SO4(exp 2-). At high radiation doses, we find that H2SO4 molecules are destroyed completely and that H2SO4 H2O is formed on subsequent warming. This hydrate is significantly more stable to radiolytic destruction than pure H2SO4, falling to an equilibrium relative abundance of 50% of its original value on prolonged irradiation. Unlike either pure H2SO4 or H2SO4 H2O, the loss of H2SO4 4H2O exhibits a strong temperature dependence, as the tetrahydrate is essentially unchanged at the highest irradiation temperatures and completely destroyed at the lowest ones, which we speculate is due to a combination of radiolytic destruction and amorphization. Furthermore, at the lower temperatures it is clear that irradiation causes the tetrahydrate spectrum to transition to one that closely resembles the monohydrate spectrum. Extrapolating our results to Europa s surface, we speculate that the variations in SO2 concentrations observed in the chaotic terrains are a result of radiation processing of lower hydration states of sulfuric acid and that the monohydrate will remain stable on the surface over geological times, while the tetrahydrate will remain stable in the warmer regions but be destroyed in the colder regions, unless it can be reformed by other processes, such as thermal reactions induced by diurnal cycling.

  17. Analytical method for the evaluation of sulfur functionalities in American coals. Final report

    SciTech Connect

    Attar, A.

    1983-05-01

    This investigation consisted of the following 6 tasks: (1) improve the instrumentation for the sulfur functional groups analysis and make it more reliable. (2) create a set of reference standards of sulfur-containing compounds. (3) examine the sulfur groups distribution in untreated and desulfurized coals. (4) examine the sulfur functionalities in raw and processed coals, i.e., liquefied coals. (5) determine the distribution of sulfur functionalities in modified coals. (6) prepare computer programs for calculations related to the distribution of sulfur functional groups in coal. Each task is discussed and results are presented. Appendix A contains the computer program used to interpret the data. 31 references, 56 figures, 17 tables.

  18. Sulfur removal from high-sulfur Illinois coal by low-temperature perchloroethylene (PCE) extraction. Final technical report, 1 September, 1992--31 August, 1993

    SciTech Connect

    Chou, M.I.M.; Lytle, J.M.; Ruch, R.R.; Kruse, C.W.; Chaven, C.; Hackley, K.C.; Hughes, R.E.; Harvey, R.D.; Frost, J.K.; Buchanan, D.H.; Stucki, J.W.; Huffman, G.P.; Huggins, F.E.

    1993-12-31

    The Midwest Ore Processing Co. (MWOPC) has reported a precombustion coal desulfurization process using perchloroethylene (PCE) at 120 C to remove up to 70% of the organic sulfur. The purposes of this research were to independently confirm and possibly to improve the organic sulfur removal from Illinois coals with the PCE desulfurization and to verify the ASTM forms-of-sulfur determination for evaluation of the process. An additional goal was to develop a dechlorination procedure to remove excess PCE from the PCE-treated coal. A laboratory scale operation of the MWOPC PCE desulfurization process was demonstrated, and a dechlorination procedure to remove excess PCE from the PCE-treated coal was developed. The authors have determined that PCE desulfurization removed mainly elemental sulfur from coal. The higher the level of coal oxidization, the larger the amount of elemental sulfur that is removed by PCE extraction. The increased elemental sulfur during short-term preoxidation is found to be pH dependent and is attributed to coal pyrite oxidation under acidic (pH < 2) conditions. The non-ASTM sulfur analyses confirmed the hypothesis that the elemental sulfur produced by oxidation of pyrite complicates the interpretation of analytical data for PCE process evaluations when only the ASTM forms-of-sulfur is used. When the ASTM method is used alone, the elemental sulfur removed during PCE desulfurization is counted as organic sulfur. A study using model compounds suggests that mild preoxidation treatment of coal described by MWOPC for removal of organic sulfur does not produce enough oxidized organic sulfur to account for the amounts of sulfur removal reported. Furthermore, when oxidation of coal-like organosulfur compounds does occur, the products are inconsistent with production of elemental sulfur, the product reported by MWOPC. Overall, it is demonstrated that the PCE process is not suitable for organic sulfur removal.

  19. Reduction mechanism of sulfur in lithium-sulfur battery: From elemental sulfur to polysulfide

    SciTech Connect

    Zheng, Dong; Yang, Xuran; Zhang, Xiaoqing; Wang, Jiankun; Qu, Deyu; Qu, Deyang

    2015-10-30

    In this study, the polysulfide ions formed during the first reduction wave of sulfur in Li–S battery were determined through both in-situ and ex-situ derivatization of polysulfides. By comparing the cyclic voltammetric results with and without the derivatization reagent (methyl triflate) as well as the in-situ and ex-situ derivatization results under potentiostatic condition, in-situ derivatization was found to be more appropriate than its ex-situ counterpart, since subsequent fast chemical reactions between the polysulfides and sulfur may occur during the timeframe of ex-situ procedures. It was found that the major polysulfide ions formed at the first reduction wave of elemental sulfur were the S42– and S52– species, while the widely accepted reduction products of S82– and S62– for the first reduction wave were in low abundance.

  20. Identification of sulfur sources and isotopic equilibria in submarine hot-springs using multiple sulfur isotopes

    NASA Astrophysics Data System (ADS)

    McDermott, Jill M.; Ono, Shuhei; Tivey, Margaret K.; Seewald, Jeffrey S.; Shanks, Wayne C.; Solow, Andrew R.

    2015-07-01

    Multiple sulfur isotopes were measured in metal sulfide deposits, elemental sulfur, and aqueous hydrogen sulfide to constrain sulfur sources and the isotopic systematics of precipitation in seafloor hydrothermal vents. Areas studied include the Eastern Manus Basin and Lau Basin back-arc spreading centers and the unsedimented basalt-hosted Southern East Pacific Rise (SEPR) and sediment-hosted Guaymas Basin mid-ocean ridge spreading centers. Chalcopyrite and dissolved hydrogen sulfide (H2S) δ34S values range from -5.5‰ to +5.6‰ in Manus Basin samples, +2.4‰ to +6.1‰ in Lau Basin samples, and +3.7‰ to +5.7‰ in SEPR samples. Values of δ34S for cubic cubanite and H2S range from -1.4‰ to +4.7‰ in Guaymas Basin samples. Multiple sulfur isotope systematics in fluid-mineral pairs from the SEPR and Lau Basin show that crustal host rock and thermochemical reduction of seawater-derived dissolved sulfate (SO4) are the primary sources of sulfur in mid-ocean ridge and some back-arc systems. At PACMANUS and SuSu Knolls hydrothermal systems in the Eastern Manus Basin, a significant contribution of sulfur is derived from disproportionation of magmatic sulfur dioxide (SO2), while the remaining sulfur is derived from crustal host rocks and SO4 reduction. At the sedimented Guaymas Basin hydrothermal system, sulfur sources include crustal host rock, reduced seawater SO4, and biogenic sulfide. Vent fluid flow through fresher, less-mature sediment supplies an increased quantity of reactant organic compounds that may reduce 34S-enriched SO4, while fluid interaction with more highly-altered sediments results in H2S characterized by a small, but isotopically-significant input of 34S-depleted biogenic sulfides. Near-zero Δ33S values in all samples implicate the abiotic processes of SO4 reduction and leaching of host rock as the major contributors to sulfur content at a high temperature unsedimented mid-ocean ridge and at a back-arc system. Δ33S values indicate that SO2 disproportionation is an additional process that contributes sulfur to a different back-arc system and to acid spring-type hydrothermal fluid circulation. At the sedimented Guaymus Basin, near-zero Δ33S values are also observed, despite negative δ34S values that indicate inputs of biogenic pyrite for some samples. In contrast with previous studies reporting isotope disequilibrium between H2S and chalcopyrite, the δ34S values of chalcopyrite sampled from the inner 1-2 mm of a chimney wall are within ±1‰ of δ34S values for H2S in the paired vent fluid, suggesting equilibrium fluid-mineral sulfur isotope exchange at 300-400 °C. Isotopic equilibrium between hydrothermal fluid H2S and precipitating chalcopyrite implies that sulfur isotopes in the chalcopyrite lining across a chimney wall may accurately record past hydrothermal activity.

  1. The Effect of Sulfur on Interstellar Extinction

    NASA Astrophysics Data System (ADS)

    Krishnarao, Dhanesh; Sofia, Ulysses

    2014-03-01

    We examine the prominence of sulfur in interstellar dust and any effects it may have on extinction. Sulfur is one of the most copious elements in the universe, so proper understanding of its role in the interstellar medium is crucial. Previous studies show little to no sulfur in interstellar dust but, recent evidence of observed interstellar grains and Glass Embedded with Metal and Sulphides (GEMS) suggest an abundance of sulfur in dust. Sulfur's location on the flat part of the curve of growth results in the need for very careful modeling in the form of the Voigt profile. We use custom-built IDL routines to perform Voigt profile fitting on Hubble Space Telescope spectroscopic data sight lines, using other species as a template to accurately fix parameters and extract column densities of sulfur in the gas.

  2. Prebiotic Synthesis of Methionine and Other Sulfur-Containing Organic Compounds on the Primitive Earth: A Contemporary Reassessment Based on an Unpublished 1958 Stanley Miller Experiment

    NASA Technical Reports Server (NTRS)

    Parker, Eric T.; Cleaves, H. James; Callahan, Michael P.; Dworkin, Jason P.; Glavin, Daniel P.; Lazcano, Antonio

    2010-01-01

    Original extracts from an unpublished 1958 experiment conducted by the late Stanley L. Miller were recently found and analyzed using modern state-of-the-art analytical methods. The extracts were produced by the action of an electric discharge on a mixture of methane (CH4), hydrogen sulfide (H2S), ammonia (NH3), and carbon dioxide (CO2). Racemic methionine was farmed in significant yields, together with other sulfur-bearing organic compounds. The formation of methionine and other compounds from a model prebiotic atmosphere that contained H2S suggests that this type of synthesis is robust under reducing conditions, which may have existed either in the global primitive atmosphere or in localized volcanic environments on the early Earth. The presence of a wide array of sulfur-containing organic compounds produced by the decomposition of methionine and cysteine indicates that in addition to abiotic synthetic processes, degradation of organic compounds on the primordial Earth could have been important in diversifying the inventory of molecules of biochemical significance not readily formed from other abiotic reactions, or derived from extraterrestrial delivery.

  3. Effects of rehydration nutrients on H2S metabolism and formation of volatile sulfur compounds by the wine yeast VL3

    PubMed Central

    2011-01-01

    In winemaking, nutrient supplementation is a common practice for optimising fermentation and producing quality wine. Nutritionally suboptimal grape juices are often enriched with nutrients in order to manipulate the production of yeast aroma compounds. Nutrients are also added to active dry yeast (ADY) rehydration media to enhance subsequent fermentation performance. In this study we demonstrate that nutrient supplementation at rehydration also has a significant effect on the formation of volatile sulfur compounds during wine fermentations. The concentration of the 'fruity' aroma compounds, the polyfunctional thiols 3-mercaptohexan-1-ol (3MH) and 3-mercaptohexyl acetate (3MHA), was increased while the concentration of the 'rotten egg' aroma compound, hydrogen sulfide (H2S), was decreased. Nutrient supplementation of the rehydration media also changed the kinetics of H2S production during fermentation by advancing onset of H2S production. Microarray analysis revealed that this was not due to expression changes within the sulfate assimilation pathway, which is known to be a major contributor to H2S production. To gain insight into possible mechanisms responsible for this effect, a component of the rehydration nutrient mix, the tri-peptide glutathione (GSH) was added at rehydration and studied for its subsequent effects on H2S formation. GSH was found to be taken up during rehydration and to act as a source for H2S during the following fermentation. These findings represent a potential approach for managing sulfur aroma production through the use of rehydration nutrients. PMID:22044590

  4. HYDROCARBON AND SULFUR SENSORS FOR SOFC SYSTEMS

    SciTech Connect

    A.M. Azad; Chris Holt; Todd Lesousky; Scott Swartz

    2003-11-01

    The following report summarizes work conducted during the Phase I program Hydrocarbon and Sulfur Sensors for SOFC Systems under contract No. DE-FC26-02NT41576. For the SOFC application, sensors are required to monitor hydrocarbons and sulfur in order to increase the operation life of SOFC components. This report discusses the development of two such sensors, one based on thick film approach for sulfur monitoring and the second galvanic based for hydrocarbon monitoring.

  5. The use of sulfur in dermatology.

    PubMed

    Gupta, Aditya K; Nicol, Karyn

    2004-01-01

    Sulfur has antifungal, antibacterial, and keratolytic activity. In the past, its use was widespread in dermatological disorders such as acne vulgaris, rosacea, seborrheic dermatitis, dandruff, pityriasis versicolor, scabies, and warts. Adverse events associated with topically applied sulfur are rare and mainly involve mild application site reactions. Sulfur, used alone or in combination with agents such as sodium sulfacetamide or salicylic acid, has demonstrated efficacy in the treatment of many dermatological conditions. PMID:15303787

  6. Ceramic-metal seals for advanced battery systems. [sodium sulfur and lithium sulfur batteries

    NASA Technical Reports Server (NTRS)

    Reed, L.

    1978-01-01

    The search for materials which are electrochemically compatible with the lithium sulfur and sodium sulfur systems is discussed. The use liquid or braze alloys, titanium hydrite coatings, and tungsten yttria for bonding beryllium with ceramic is examined.

  7. Charles H. Winston and Confederate Sulfuric Acid

    NASA Astrophysics Data System (ADS)

    Reithmiller, Steven

    1995-07-01

    Sulfuric acid turned out to be one of the critical chemicals made in the South during the Civil War. It was necessary for the manufacture of mercury fulminate which was used in the production of percussion caps and sulfuric acid was used in the Daniells cell to produce electricity. Charles H. Winston, president of the Richmond Female Institute and later professor at the University of Richmond (VA) was instrumental in the establishment of a plant to manufacture sulfuric acid in Charlotte, North Carolina. His patent and method of manufacture plus the uses of sulfuric acid during the Civil War are discussed.

  8. Elemental sulfur in Eddy County, New Mexico

    USGS Publications Warehouse

    Hinds, Jim S.; Cunningham, Richard R.

    1970-01-01

    Sulfur has been reported in Eddy County, N. Mex., in rocks ranging from Silurian to Holocene in age at depths of 0-15,020 feet. Targets of present exploration are Permian formations in the Delaware Basin and northwest shelf areas at depths of less than 4,000 feet. Most of the reported sulfur occurrences in the shelf area are in the 'Abo' (as used by some subsurface geologists), Yeso, and San Andres Formations and the Artesia Group. Sulfur deposition in the dense dolomites of the 'Abo,' Yeso, and San Andres Formations is attributed to the reduction of ionic sulfate by hydrogen sulfide in formation waters in zones of preexisting porosity and permeability. A similar origin accounts for most of the sulfur deposits in the formations of the Artesia Group, but some of the sulfur in these formations may have originated in place through the alteration of anhydrite to carbonate and sulfur by the metabolic processes of bacteria in the presence of hydrocarbons. Exploration in the Delaware Basin area is directed primarily toward the Castile Formation. Sulfur deposits in the Castile Formation are found in irregular masses of cavernous brecciated secondary carbonate rock enveloped by impermeable anhydrite. The carbonate masses, or 'castiles,' probably originated as collapse features resulting from subsurface solution and upward stopping. Formation of carbonate rock and sulfur in the castiles is attributed to the reduction of brecciated anhydrite by bacteria and hydrocarbons in the same process ascribed to the formation of carbonate and sulfur in the caprocks of salt domes.

  9. Options for small-scale sulfur recovery

    SciTech Connect

    Royan, T.; Wichert, E.

    1997-11-01

    With the issuance by the Alberta Energy Resources Conservation Board and Alberta Environment of their report entitled Sulphur Recovery Guidelines for Sour Gas Plants in Alberta in August of 1988, the requirement in Alberta to recover sulfur was broadened to a sulfur content of 1 ton/D or greater in the inlet gas to a new sour-gas treating plant. This paper reviews the processes in use for recovering sulfur from sour-natural-gas streams that have a total sulfur content of 5 ton/D or less. These processes are the modified Claus process, the recycle Selectox process, and the reduction/oxidation processes LO-CAT and SulFerox. While the modified Claus process is used in large sulfur-recovery plants, the other processes may be more economical for sulfur recovery on a small scale. A description of the sour-gas treating and sulfur-recovery processes is given, and a comparison of estimated capital and operating costs for typical sour-gas streams is provided. All of the above processes are in operation in North America. Operating experiences with these processes in Alberta are discussed. The quality of the end-product sulfur varies among these processes, and the options for sulfur disposal are reviewed.

  10. Are the clouds of Venus sulfuric acid.

    NASA Technical Reports Server (NTRS)

    Young, A. T.

    1973-01-01

    It is shown that strong aqueous sulfuric acid solutions have the right refractive index and freeze at Venusian cloud temperature, explain the dryness of the Venusian stratosphere, are consistent with some features of the Venusian IR spectrum, and do not absorb in highly reflecting areas of Venus. It is also indicated that such solutions should be produced by reactions between known atmospheric constituents and most sulfur-bearing rock at the Venusian surface temperature, and require only small amounts of sulfur consistent with its cosmic abundance and with the amounts of other volatile elements present in the atmosphere. It is believed therefore that the clouds of Venus consist of sulfuric acid solutions.

  11. Doped carbon-sulfur species nanocomposite cathode for Li--S batteries

    DOEpatents

    Wang, Donghai; Xu, Tianren; Song, Jiangxuan

    2015-12-29

    We report a heteroatom-doped carbon framework that acts both as conductive network and polysulfide immobilizer for lithium-sulfur cathodes. The doped carbon forms chemical bonding with elemental sulfur and/or sulfur compound. This can significantly inhibit the diffusion of lithium polysulfides in the electrolyte, leading to high capacity retention and high coulombic efficiency.

  12. Sulfur and Hydrogen Isotope Anomalies in Meteorite Sulfonic Acids

    NASA Technical Reports Server (NTRS)

    Cooper, George W.; Thiemens, Mark H.; Jackson, Teresa L.; Chang, Sherwood

    1997-01-01

    Intramolecular carbon, hydrogen, and sulfur isotope ratios were measured on a homologous series of organic sulfonic acids discovered in the Murchison meteorite. Mass-independent sulfur isotope fractionations were observed along with high deuterium/hydrogen ratios. The deuterium enrichments indicate formation of the hydrocarbon portion of these compounds in a low-temperature environment that is consistent with that of interstellar clouds. Sulfur-33 enrichments observed in methanesulfonic acid could have resulted from gas-phase ultraviolet irradiation of a precursor, carbon disulfide. The source of the sulfonic acid precursors may have been the reactive interstellar molecule carbon monosulfide.

  13. Microbial desulfurization of organic sulfur in coal

    SciTech Connect

    Klubek, B.; Ochman, M.; Clark, D.

    1985-05-01

    Microbial desulfurization of coal before combustion has lower operating costs and is more energy efficient than high-temperature chemical processes. At present, both Thiobacillus and Sulfolobus have been shown capable of converting the inorganic sulfur in coal into a soluble sulfate, which can be washed out. This paper discusses research to developing bacteria able to degrade organic sulfur components. Three groups of organosulfur decomposers have been isolated. The first group isolates is capable of a partial degradation of dibenzothiophene to 3-hydroxy-2-formyl-benzothiophene, but sulfur is not liberated from this compound. The second group is capable of decomposing thiophene acetic acid and produces small amounts of H/sub 2/SO/sub 4/. The third group degrades thiophene carboxylic acid but produces large amounts of H/sub 2/SO/sub 4/. The third group degrades thiophene carboxylic acid but produces large amounts of H/sub 2/SO/sub 4/. Research on the use of Escherichia coli is also discussed.

  14. Sulfur recovery process including removal of residual sulfur from Claus catalyst after regeneration

    SciTech Connect

    Cabanaw, B.E.

    1990-03-13

    This patent describes a process for the recovery of sulfur. It comprises: passing an acid gas feedstream having as a sulfur species essentially only hydrogen sulfide therein to a Claus plant comprising a thermal conversion zone and at least one Claus catalytic reaction zone operated under adsorption conditions including temperature for forming and depositing a preponderance of sulfur formed on catalyst therein.

  15. Graphene-wrapped sulfur nanospheres with ultra-high sulfur loading for high energy density lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Liu, Ya; Guo, Jinxin; Zhang, Jun; Su, Qingmei; Du, Gaohui

    2015-01-01

    Lithium-sulfur (Li-S) battery with high theoretical energy density is one of the most promising energy storage systems for electric vehicles and intermittent renewable energy. However, due to the poor conductivity of the active material, considerable weight of the electrode is occupied by the conductive additives. Here we report a graphene-wrapped sulfur nanospheres composite (S-nanosphere@G) with sulfur content up to 91 wt% as the high energy density cathode material for Li-S battery. The sulfur nanospheres with diameter of 400-500 nm are synthesized through a solution-based approach with the existence of polyvinylpyrrolidone (PVP). Then the sulfur nanospheres are uniformly wrapped by conductive graphene sheets through the electrostatic interaction between graphene oxide and PVP, followed by reducing of graphene oxide with hydrazine. The design of graphene wrapped sulfur nanoarchitecture provides flexible conductive graphene coating with void space to accommodate the volume expansion of sulfur and to minimize polysulfide dissolution. As a result, the S-nanosphere@G nanocomposite with 91 wt% sulfur shows a reversible initial capacity of 970 mA h g-1 and an average columbic efficiency > 96% over 100 cycles at a rate of 0.2 C. Taking the total mass of electrode into account, the S-nanosphere@G composite is a promising cathode material for high energy density Li-S batteries.

  16. Spectroscopic Detection and Structure of Hydroxidooxidosulfur (HOSO) Radical, an Important Intermediate in the Chemistry of Sulfur-Bearing Compounds

    NASA Astrophysics Data System (ADS)

    McCarthy, Michael C.; Lattanzi, Valerio; Martinez, Oscar, Jr.; Gauss, Jrgen; Thorwirth, Sven

    2013-11-01

    The rotational spectrum of hydroxidooxidosulfur, HOSO, an intermediate of particular interest in the combustion of sulfur-rich fuels, has been determined to high accuracy from gas-phase measurements. Detection of specific isotopic species using isotopically enriched gases suggests that HOSO is formed in our discharge nozzle via the reaction H + SO2 (+M) ? HOSO (+M). A precise experimental r0 geometry has also been derived from the isotopic analysis; HOSO has a cis configuration, but the subtle structural question of its planarity remains unresolved. From the derived spectroscopic constants, in situ and remote sensing for this fundamental radical can now be undertaken in a variety of environments, including in combustion reactors, the troposphere of Earth, and Io, the innermost Galilean moon of Jupiter.

  17. The Distribution of Sulfur Dioxide and Other Compounds on the Surface of Io as Seen by the Near Infrared Mapping Spectrometer

    NASA Astrophysics Data System (ADS)

    Douté, S.; Lopes-Gautier, R.; Schmitt, B.; Carlson, R.; Geissler, P. E.; Galileo NIMS Team

    2000-10-01

    The surface of Io is shaped by various interrelated volcanic, atmospheric and magnetospheric phenomena. Albedo and color changes, that occur in the visible at short distances from many volcanic centers displaying high thermal emission, constitute the most prominent signs of this intense activity. Liquid materials flow from the vents, gases and solid pyroclastics condense or settle on the surface. Curiously, little is known about the precise chemical nature and physical state of these materials. The high temperature hot-spots detected by the IR spectro-imager NIMS and the camera SSI of Galileo suggest the existence of large silicate lava fields but their spectral detection in the visible and near infrared is still ambiguous. The white, yellow, red, orange or brown hues that give Io its colorful appearance suggest abundance of sulfur-bearing compounds such as SO2, native and short chain sulfur, sulfur oxides. Nevertheless none of these compounds have been clearly identified, except SO2 thanks to its numerous and distinctive absorption bands in the NIR. Other components, like H2S, Na2S, Na2SO4, and NaCl, have been proposed from thermochemical models of volcanic gases for example, but still wait to be detected. The analysis of NIMS IR observations at different spatial scale can give us some clues to understand the real nature of Io's surface. In our presentation we will give an updated review of what we have found so far in terms of identification, mapping and physical state of the materials, with an emphasis on the SO2. This work was begun at the Laboratoire de Planétologie de Grenoble with the support of the French Programme National de Planétologie, and continued under contract with NASA through the Jupiter System Data Analysis Program.

  18. Contribution of Gulf Area natural sulfur to the North American sulfur budget

    SciTech Connect

    Luria, M.; Van Valin, C.C.; Wellman, D.L.; Pueschel, R.F.

    1986-01-01

    To evaluate the contribution of natural sulfur compounds from the Gulf of Mexico to the overall North American sulfur budget two series of air sampling flights were performed over the gulf area. Total aerosol mass load and sulfate concentration data indicate, in agreement with our previous findings on gas-phase products, that these observations can be divided into two categories. One group of measurements was taken under offshore airflow and the other under onshore flow conditions. From the measurements performed under clean (onshore) flow, average inside boundary layer SO/sub 4//sup 2 -/ concentrations were evaluated. Using these data, together with our previously reported dimethyl sulfide levels, a simple model was developed to estimate the sulfur flux transported northward from the gulf area. Upper and lower limits of this contribution are estimated at 0.25 and 0.04 Tg (S) year/sup -1/, respectively. Although this quantity is relatively low compared with the national US anthropogenic emission, it has significance for the global sulfur cycle, and it can cause a significant acidification of cloud water. 24 references, 5 figures, 3 tables.

  19. Method for the improvement of the oxidation resistance of hydrocarbon oil, especially transformer oils by the selective removal of pro-oxidant nitrogen and sulfur compounds therefrom

    SciTech Connect

    Felsky, G.

    1984-02-07

    Liquid hydrocarbon streams, preferably petroleum streams, most preferably lube and specialty oil streams and in particular transformer oils are rendered resistant to oxidation by treatment with a silver salt impregnated adsorbent, preferably silver nitrate impregnated alumina by the process of contacting the hydrocarbon oil stream with the silver salt impregnated adsorbent and recovering a hydrocarbon stream of reduced pro-oxidant heteroatom compound (nitrogen compound and sulfur compound) content. The silver salt impregnated adsorbent is regenerated by sequential washing with portions of aromatic solvent and polar solvent. The aromatic solvent strips aromatic sulfides from the adsorbent. This fraction may be recombined with the hydrocarbon stream, especially in the case of transformer oils, so as to enhance the oxidation stability/resistance of the oil. The polar solvent, such as 3% methanol in toluene, strips the aliphatic sulfides from the adsorbent. The regenerated column is then ready for reuse.

  20. Sulfur-carbon nanocomposites and their application as cathode materials in lithium-sulfur batteries

    SciTech Connect

    Liang, Chengdu; Dudney, Nancy J; Howe, Jane Y

    2015-05-05

    The invention is directed in a first aspect to a sulfur-carbon composite material comprising: (i) a bimodal porous carbon component containing therein a first mode of pores which are mesopores, and a second mode of pores which are micropores; and (ii) elemental sulfur contained in at least a portion of said micropores. The invention is also directed to the aforesaid sulfur-carbon composite as a layer on a current collector material; a lithium ion battery containing the sulfur-carbon composite in a cathode therein; as well as a method for preparing the sulfur-composite material.

  1. 46 CFR 148.315 - Sulfur.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... deck sweepings must be disposed of pursuant to 33 CFR 151.55 through 151.77. (c) A cargo space that... 46 Shipping 5 2011-10-01 2011-10-01 false Sulfur. 148.315 Section 148.315 Shipping COAST GUARD... SPECIAL HANDLING Special Requirements for Certain Materials § 148.315 Sulfur. (a) This part applies...

  2. 21 CFR 184.1095 - Sulfuric acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... known as oil of vitriol, is a clear, colorless, oily liquid. It is prepared by reacting sulfur dioxide (SO2) with oxygen and mixing the resultant sulfur trioxide (SO3) with water, or by reacting...

  3. Dielectric strength of sulfur hexafluoride upon condensation

    SciTech Connect

    Antonov, A.V.; Lyapin, A.G.; Popkov, V.I.

    1983-01-01

    The behavior of sulfur hexafluoride in a sealed high-voltage device has been modeled for cooling to the condensation point of the insulating medium. The temperature dependences of the breakdown voltages of sulfur hexafluoride have been investigated for several interelectrode separations. The dielectric strength has been shown to decrease upon condensation with formation of a bridge of boiling liquid phase between the electrodes.

  4. Sulfur oxide adsorbents and emissions control

    DOEpatents

    Li, Liyu; King, David L.

    2006-12-26

    High capacity sulfur oxide absorbents utilizing manganese-based octahedral molecular sieve (Mn--OMS) materials are disclosed. An emissions reduction system for a combustion exhaust includes a scrubber 24 containing these high capacity sulfur oxide absorbents located upstream from a NOX filter 26 or particulate trap.

  5. SURFACE REACTIONS OF OXIDES OF SULFUR

    EPA Science Inventory

    Surface reactions of several sulfur-containing molecules have been studied in order to understand the mechanism by which sulfate ions are formed on atmospheric aerosols. At 25C the heterogeneous oxidation of SO2 by NO2 to sulfuric acid and sulfate ions occurred on hydrated silica...

  6. Sulfur recovery plant and process using oxygen

    SciTech Connect

    Palm, J.W.

    1989-01-17

    This patent describes a process for the recovery of sulfur from a gaseous stream containing hydrogen sulfide, the process comprising the steps of: (a) introducing a thermal reaction mixture comprising (1) the gaseous stream containing hydrogen sulfide, and (2) an oxygen-enriched stream of air or pure oxygen into a combustion zone of a Claus furnace; (b) combusting the thermal reaction mixture in the Claus furnace to thereby produce hot combustion gases comprising hydrogen sulfide, sulfur dioxide, carbon dioxide, water, and elemental sulfur; (c) introducing the hot combustion gases into a Claus catalytic reactor; (d) subjecting the hot combustion gases in the catalytic reactor to Claus reaction conditions in the presence of a Claus catalyst to thereby produce a Claus plant gaseous effluent stream comprising hydrogen sulfide, sulfur dioxide, carbon dioxide, water, and elemental sulfur; (e) introducing the Claus plant gaseous effluent into a condenser to thereby produce liquid sulfur, which is recovered, and a gaseous condenser effluent, which comprises hydrogen sulfide, sulfur dioxide, carbon dioxide and water; (f) converting substantially all sulfur species in the gaseous condenser effluent to hydrogen sulfide, to thereby form a condenser effluent comprising hydrogen sulfide, carbon dioxide and water; (g) removing water from the condenser effluent from step (f); and (h) moderating the temperature in the Claus furnace by returning at least a portion of the dried condenser effluent from step (g), as a diluent stream, to a combustion zone of the Claus furnace in step (a) above.

  7. Sulfur recovery plant and process using oxygen

    SciTech Connect

    Palm, J.W.

    1989-07-18

    This patent describes a process for recovery of sulfur from a gaseous stream containing hydrogen sulfide. The process consists the steps of: introducing a thermal reaction mixture comprising the gaseous stream containing hydrogen sulfide, and an oxygen-enriched stream of air or pure oxygen into a combustion zone of a Claus furnace; combusting the thermal reaction mixture in the Claus furnace to thereby produce hot combustion gases comprising hydrogen sulfide, sulfur dioxide, carbon dioxide, water, and elemental sulfur; introducing the hot combustion gases into a Claus catalytic reactor; subjecting the hot combustion gases in the catalytic reactor to Claus reaction conditions in the presence of a Claus catalyst to thereby produce a Claus plant gaseous effluent stream comprising hydrogen sulfide, sulfur dioxide, carbon dioxide, water, and elemental sulfur; introducing the Claus plant gaseous effluent into a condenser to thereby produce liquid sulfur, which is recovered, and a gaseous condenser effluent, which comprises hydrogen sulfide, sulfur dioxide, carbon dioxide and water and which is divided into a recycle portion and a tailgas portion; converting substantially all sulfur species in the recycle portion of the gaseous condenser effluent to hydrogen sulfide to thereby form condenser effluent comprising hydrogen sulfide, carbon dioxide and water; removing water from the recycle portion of the condenser; and moderating the temperature in the Claus furnace by returning at least a portion of the dried recycle condenser, as a diluent stream, to a combustion zone of the Claus furnace.

  8. Sulfur in Distillers Grains for Dairy Cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sulfur is an essential element needed by animals for many functions. About 0.15% of the body weight is sulfur. It is found in the amino acids methionine, cysteine, cystine, homocysteine, and taurine; in chondroitin sulfate of cartilage; and in the B-vitamins, thiamin and biotin. Methionine, thiam...

  9. Sulfuric Acid and Water: Paradoxes of Dilution

    ERIC Educational Resources Information Center

    Leenson, I. A.

    2004-01-01

    On equilibrium properties of aqueous solutions of sulfuric acid, Julius Thomsen has marked that the heat evolved on diluting liquid sulfuric acid with water is a continuous function of the water used, and excluded absolutely the acceptance of definite hydrates as existing in the solution. Information about thermochemical measurement, a discussion…

  10. 46 CFR 153.1046 - Sulfuric acid.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Sulfuric acid. 153.1046 Section 153.1046 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Special Cargo Procedures § 153.1046 Sulfuric acid. No person may...

  11. Stabilized sulfur binding using activated fillers

    DOEpatents

    Kalb, Paul D.; Vagin, Vyacheslav P.; Vagin, Sergey P.

    2015-07-21

    A method of making a stable, sulfur binding composite comprising impregnating a solid aggregate with an organic modifier comprising unsaturated hydrocarbons with at least one double or triple covalent bond between adjacent carbon atoms to create a modifier-impregnated aggregate; heating and drying the modifier-impregnated aggregate to activate the surface of the modifier-impregnated aggregate for reaction with sulfur.

  12. Seawater sulfur isotope fluctuations in the Cretaceous.

    PubMed

    Paytan, Adina; Kastner, Miriam; Campbell, Douglas; Thiemens, Mark H

    2004-06-11

    The exogenic sulfur cycle is tightly coupled with the carbon and oxygen cycles, and therefore a central component of Earth's biogeochemistry. Here we present a high-resolution record of the sulfur isotopic composition of seawater sulfate for the Cretaceous. The general enrichment of isotopically light sulfur that prevailed during the Cretaceous may have been due to increased volcanic and hydrothermal activity. Two excursions toward isotopically lighter sulfur represent periods of lower rates of pyrite burial, implying a shift in the location of organic carbon burial to terrestrial or open-ocean settings. The concurrent changes in seawater sulfur and inorganic carbon isotopic compositions imply short-term variability in atmospheric oxygen partial pressure. PMID:15192227

  13. Sulfur Metabolism in the Extreme Acidophile Acidithiobacillus Caldus

    PubMed Central

    Mangold, Stefanie; Valdés, Jorge; Holmes, David S.; Dopson, Mark

    2011-01-01

    Given the challenges to life at low pH, an analysis of inorganic sulfur compound (ISC) oxidation was initiated in the chemolithoautotrophic extremophile Acidithiobacillus caldus. A. caldus is able to metabolize elemental sulfur and a broad range of ISCs. It has been implicated in the production of environmentally damaging acidic solutions as well as participating in industrial bioleaching operations where it forms part of microbial consortia used for the recovery of metal ions. Based upon the recently published A. caldus type strain genome sequence, a bioinformatic reconstruction of elemental sulfur and ISC metabolism predicted genes included: sulfide–quinone reductase (sqr), tetrathionate hydrolase (tth), two sox gene clusters potentially involved in thiosulfate oxidation (soxABXYZ), sulfur oxygenase reductase (sor), and various electron transport components. RNA transcript profiles by semi quantitative reverse transcription PCR suggested up-regulation of sox genes in the presence of tetrathionate. Extensive gel based proteomic comparisons of total soluble and membrane enriched protein fractions during growth on elemental sulfur and tetrathionate identified differential protein levels from the two Sox clusters as well as several chaperone and stress proteins up-regulated in the presence of elemental sulfur. Proteomics results also suggested the involvement of heterodisulfide reductase (HdrABC) in A. caldus ISC metabolism. A putative new function of Hdr in acidophiles is discussed. Additional proteomic analysis evaluated protein expression differences between cells grown attached to solid, elemental sulfur versus planktonic cells. This study has provided insights into sulfur metabolism of this acidophilic chemolithotroph and gene expression during attachment to solid elemental sulfur. PMID:21687411

  14. Mass-dependent sulfur isotope fractionation during reoxidative sulfur cycling: A case study from Mangrove Lake, Bermuda

    NASA Astrophysics Data System (ADS)

    Pellerin, André; Bui, Thi Hao; Rough, Mikaella; Mucci, Alfonso; Canfield, Donald E.; Wing, Boswell A.

    2015-01-01

    The multiple sulfur isotope composition of porewater sulfate from the anoxic marine sapropel of Mangrove Lake, Bermuda was measured in order to establish how multiple sulfur isotopes are fractionated during reoxidative sulfur cycling. The porewater-sulfate δ34S and Δ33S dataset exhibits the distinct isotopic signatures of microbial sulfate reduction and sulfur reoxidation. We reproduced the measurements with a simple diagenetic model that yielded fractionation factors for net sulfate removal of between -29.2‰ and -32.5‰. A new approach to isotopic modeling of the sulfate profiles, informed by the chemistry of sulfur intermediate compounds in Mangrove Lake, reveals that sulfate reduction produces a relatively small intrinsic fractionation and that an active reoxidative sulfur cycle increases the fractionation of the measured values. Based on the model results, the reoxidative cycle of Mangrove Lake appears to include sulfide oxidation to elemental sulfur followed by the disproportionation of the elemental sulfur to sulfate and sulfide. This model also indicates that the reoxidative sulfur cycle of Mangrove Lake turns over from 50 to 80% of the sulfide produced by microbial sulfate reduction. The Mangrove Lake case study shows how sulfur isotope fractionations can be separated into three different "domains" in Δ33S-δ34S space based on their ability to resolve reductive and reoxidative sulfur transformations. The first domain that differentiates reductive and reoxidative sulfur cycling is well illustrated by previous studies and requires 34S-32S fractionations more negative than ≈-70‰, beyond the fractionation limit of microbial sulfate reduction at earth surface temperatures. The second domain that distinguishes reductive and reoxidative processes is between 34S-32S fractionations of -40‰ and 0‰, where the 33S-32S fractionations of sulfate reduction and reoxidation are significantly different. In the remaining domain (between 34S-32S fractionations -70‰ and -40‰), the similarity of the multiple sulfur isotope signals from microbial sulfate reduction and disproportionation means that the two processes cannot be discriminated from each other.

  15. Process and apparatus for recovery of sulfur from ammonia containing acid gas streams

    SciTech Connect

    Palm, J.W.

    1987-02-17

    This patent describes a Claus process for the recovery of sulfur, the steps comprising: passing a first stream containing hydrogen sulfide, sulfur dioxide, and ammonia through a low temperature Claus catalytic conversion zone and depositing elemental sulfur and ammonium compounds on catalyst therein; deriving a regeneration stream from the Claus process and regenerating the resulting laden catalyst therewith vaporizing sulfur and ammonia therefrom and producing a regeneration effluent stream comprising elemental sulfur and ammonia; cooling the regeneration effluent stream and condensing elemental sulfur therefrom and producing a sulfur lean regeneration effluent stream; introducing at least a portion of the sulfur lean regeneration effluent stream into a hydrogenation zone and converting substantially all sulfur compounds therein to hydrogen sulfide. The resulting hydrogen sulfide containing stream is introduced into an ammonia removal zone. The resulting stream is contacted with a first aqueous stream and produces a second aqueous stream enriched in ammonia and a sulfur lean regeneration effluent stream reduced in ammonia content; removing ammonia from the second aqueous stream and producing an ammonia enriched stream; returning the sulfur lean regeneration effluent stream reduced in ammonia content to the Claus process adjacent and downstream of the point of derivation of the regeneration stream for the further recovery of sulfur therefrom; and introducing the ammonia enriched stream into an ammonia conversion zone and reducing the concentration of ammonia therein.

  16. Development of instrumental methods of analysis of sulfur compounds in coal process streams. Quarterly technical progress report for October-December 1980

    SciTech Connect

    Jordan, J.; Stutts, J. D.; Ankabrandt, S. J.; Stahl, J.; Yakupkovic, J. E.

    1981-01-01

    Work is in progress on the preparation of a user-oriented computer software manual, for estimating sulfur speciation in aqueous coal process streams form a thermodynamic data base. Capabilities and limitations of sulfide and polysulfide analysis by differential pulse polarography at a dropping mercury anode are assessed critically. Thallous nitrate used as the titrant reagent in a thermometric enthalpy titration yields the molar sum of monosulfide and polysulfide. Inorganic sulfur has been successfully speciated in coal conversion by-product water samples. A combination of differential pulse voltammetry, thermometric enthalpy titrations and classical methods was used. One hundred percent of the total sulfur present was quantitatively accounted for.

  17. Sulfur enrichment of humic substances in a Delaware salt marsh sediment core

    SciTech Connect

    Ferdelman, T.G.; Church, T.M.; Luther, G.W. )

    1991-04-01

    Humic sulfur, operationally defined as the sulfur extracted with humic substances in 0.1 N NaOH solution, comprises up to 51{percent} of the total sulfur inventory in a sediment core taken from a Delaware Spartina alterniflora marsh. Pyrite sulfur is the next largest fraction, except at the near-surface sediments, where zerovalent sulfur concentrations are significant. X-ray photoelectron spectroscopy indicates that the humic sulfur consists of sulfoxides or sulfones and, in a more reduced state, organic sulfides and/or organic polysulfides. A subsurface decrease in the humic acid C:S atomic ratio to 56 {plus minus} 2 suggests that the upper 4 cm of marsh sediment is the locus for humic sulfur formation. S. alterniflora detritus and microbial biomass cannot fully account for observed sulfur enrichment of humic C:S atomic ratios. Therefore, the enrichment of humic substances by sulfur is probably via reaction of reduced sulfur compounds with organic matter. A humic sulfur formation rate of 10.6 {mu}mol S {center dot} cm{sup {minus}3} {center dot} a{sup {minus}1} is calculated for the surface sediments and leads to an areal production of 18 {mu}mol S {center dot} cm{sup {minus}2} {center dot} a{sup {minus}1} of humic sulfur. Humic sulfur formation and preservation is enhanced by the limited availability of iron for the rapid precipitation of iron sulfide minerals and the apparent resistance of organic sulfur compounds towards reoxidation to sulfate, especially in the upper 9 cm of marsh sediment where inorganic sulfur compounds are rapidly oxidized.

  18. Magnetic effects in sulfur-decorated graphene.

    PubMed

    Hwang, Choongyu; Cybart, Shane A; Shin, S J; Kim, Sooran; Kim, Kyoo; Rappoport, T G; Wu, S M; Jozwiak, C; Fedorov, A V; Mo, S-K; Lee, D-H; Min, B I; Haller, E E; Dynes, R C; Castro Neto, A H; Lanzara, Alessandra

    2016-01-01

    The interaction between two different materials can present novel phenomena that are quite different from the physical properties observed when each material stands alone. Strong electronic correlations, such as magnetism and superconductivity, can be produced as the result of enhanced Coulomb interactions between electrons. Two-dimensional materials are powerful candidates to search for the novel phenomena because of the easiness of arranging them and modifying their properties accordingly. In this work, we report magnetic effects in graphene, a prototypical non-magnetic two-dimensional semi-metal, in the proximity with sulfur, a diamagnetic insulator. In contrast to the well-defined metallic behaviour of clean graphene, an energy gap develops at the Fermi energy for the graphene/sulfur compound with decreasing temperature. This is accompanied by a steep increase of the resistance, a sign change of the slope in the magneto-resistance between high and low fields, and magnetic hysteresis. A possible origin of the observed electronic and magnetic responses is discussed in terms of the onset of low-temperature magnetic ordering. These results provide intriguing insights on the search for novel quantum phases in graphene-based compounds. PMID:26888720

  19. Magnetic effects in sulfur-decorated graphene

    NASA Astrophysics Data System (ADS)

    Hwang, Choongyu; Cybart, Shane A.; Shin, S. J.; Kim, Sooran; Kim, Kyoo; Rappoport, T. G.; Wu, S. M.; Jozwiak, C.; Fedorov, A. V.; Mo, S.-K.; Lee, D.-H.; Min, B. I.; Haller, E. E.; Dynes, R. C.; Castro Neto, A. H.; Lanzara, Alessandra

    2016-02-01

    The interaction between two different materials can present novel phenomena that are quite different from the physical properties observed when each material stands alone. Strong electronic correlations, such as magnetism and superconductivity, can be produced as the result of enhanced Coulomb interactions between electrons. Two-dimensional materials are powerful candidates to search for the novel phenomena because of the easiness of arranging them and modifying their properties accordingly. In this work, we report magnetic effects in graphene, a prototypical non-magnetic two-dimensional semi-metal, in the proximity with sulfur, a diamagnetic insulator. In contrast to the well-defined metallic behaviour of clean graphene, an energy gap develops at the Fermi energy for the graphene/sulfur compound with decreasing temperature. This is accompanied by a steep increase of the resistance, a sign change of the slope in the magneto-resistance between high and low fields, and magnetic hysteresis. A possible origin of the observed electronic and magnetic responses is discussed in terms of the onset of low-temperature magnetic ordering. These results provide intriguing insights on the search for novel quantum phases in graphene-based compounds.

  20. Magnetic effects in sulfur-decorated graphene

    PubMed Central

    Hwang, Choongyu; Cybart, Shane A.; Shin, S. J.; Kim, Sooran; Kim, Kyoo; Rappoport, T. G.; Wu, S. M.; Jozwiak, C.; Fedorov, A. V.; Mo, S.-K.; Lee, D.-H.; Min, B. I.; Haller, E. E.; Dynes, R. C.; Castro Neto, A. H.; Lanzara, Alessandra

    2016-01-01

    The interaction between two different materials can present novel phenomena that are quite different from the physical properties observed when each material stands alone. Strong electronic correlations, such as magnetism and superconductivity, can be produced as the result of enhanced Coulomb interactions between electrons. Two-dimensional materials are powerful candidates to search for the novel phenomena because of the easiness of arranging them and modifying their properties accordingly. In this work, we report magnetic effects in graphene, a prototypical non-magnetic two-dimensional semi-metal, in the proximity with sulfur, a diamagnetic insulator. In contrast to the well-defined metallic behaviour of clean graphene, an energy gap develops at the Fermi energy for the graphene/sulfur compound with decreasing temperature. This is accompanied by a steep increase of the resistance, a sign change of the slope in the magneto-resistance between high and low fields, and magnetic hysteresis. A possible origin of the observed electronic and magnetic responses is discussed in terms of the onset of low-temperature magnetic ordering. These results provide intriguing insights on the search for novel quantum phases in graphene-based compounds. PMID:26888720

  1. A mesoporous carbon–sulfur composite as cathode material for high rate lithium sulfur batteries

    SciTech Connect

    Choi, Hyunji; Zhao, Xiaohui; Kim, Dul-Sun; Ahn, Hyo-Jun; Kim, Ki-Won; Cho, Kwon-Koo; Ahn, Jou-Hyeon

    2014-10-15

    Highlights: • CMK-3 mesoporous carbon was synthesized as conducting reservoir for housing sulfur. • Sulfur/CMK-3 composites were prepared by two-stage thermal treatment. • The composite at 300 °C for 20 h shows improved electrochemical properties. - Abstract: Sulfur composite was prepared by encapsulating sulfur into CMK-3 mesoporous carbon with different heating times and then used as the cathode material for lithium sulfur batteries. Thermal treatment at 300 °C plays an important role in the sulfur encapsulation process. With 20 h of heating time, a portion of sulfur remained on the surface of carbon, whereas with 60 h of heating time, sulfur is confined deeply in the small pores of carbon that cannot be fully exploited in the redox reaction, thus causing low capacity. The S/CMK-3 composite with thermal treatment for 40 h at 300 °C contained 51.3 wt.% sulfur and delivered a high initial capacity of 1375 mA h g{sup −1} at 0.1 C. Moreover, it showed good capacity retention of 704 mA h g{sup −1} at 0.1 C and 578 mA h g{sup −1} at 2 C even after 100 cycles, which proves its potential as a cathode material for high capability lithium sulfur batteries.

  2. Sulfur nanocrystals anchored graphene composite with highly improved electrochemical performance for lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Dong, Zimin; Wang, Xiuli; Zhao, Xuyang; Tu, Jiangping; Su, Qingmei; Du, Gaohui

    2014-12-01

    Two kinds of graphene-sulfur composites with 50 wt% of sulfur are prepared using hydrothermal method and thermal mixing, respectively. Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray Spectra mapping show that sulfur nanocrystals with size of ˜5 nm dispersed on graphene sheets homogeneously for the sample prepared by hydrothermal method (NanoS@G). While for the thermal mixed graphene-sulfur composite (S-G mixture), sulfur shows larger and uneven size (50-200 nm). X-ray Photoelectron Spectra (XPS) reveals the strong chemical bonding between the sulfur nanocrystals and graphene. Comparing with the S-G mixture, the NanoS@G composite shows highly improved electrochemical performance as cathode for lithium-sulfur (Li-S) battery. The NanoS@G composite delivers an initial capacity of 1400 mAh g-1 with the sulfur utilization of 83.7% at a current density of 335 mA g-1. The capacity keeps above 720 mAh g-1 over 100 cycles. The strong adherence of the sulfur nanocrystals on graphene immobilizes sulfur and polysulfides species and suppressed the “shuttle effect”, resulting higher coulombic efficiency and better capacity retention. Electrochemical impedance also suggests that the strong bonding enabled rapid electronic/ionic transport and improved electrochemical kinetics, therefore good rate capability is obtained. These results demonstrate that the NanoS@G composite is a very promising candidate for high-performance Li-S batteries.

  3. Sodium sulfur battery flight experiment definition study

    NASA Astrophysics Data System (ADS)

    Chang, Rebecca R.; Minck, Robert

    1989-12-01

    Sodium-sulfur batteries were identified as the most likely successor to nickel-hydrogen batteries for space applications. One advantage of the Na/S battery system is that the usable specific energy is two to three times that of nickel-hydrogen batteries. This represents a significant launch cost savings or increased payload mass capabilities. Sodium-sulfur batteries support NASA OAST's proposed Civil Space Technology Initiative goal of a factor of two improvement in spacecraft power system performance, as well as the proposed Spacecraft 2000 initiative. The sodium-sulfur battery operates at between 300 and 400 C, using liquid sodium and sulfur/polysulfide electrodes and solid ceramic electrolyte. The transport of the electrode materials to the surface of the electrolyte is through wicking/capillary forces. These critical transport functions must be demonstrated under actual microgravity conditions before sodium-sulfur batteries can be confidently utilized in space. Ford Aerospace Corporation, under contract to NASA Lewis Research Center, is currently working on the sodium-sulfur battery space flight experiment definition study. The objective is to design the experiment that will demonstrate operation of the sodium-sulfur battery/cell in the space environment with particular emphasis on evaluation of microgravity effects. Experimental payload definitions were completed and preliminary designs of the experiment were defined.

  4. Sodium sulfur battery flight experiment definition study

    NASA Technical Reports Server (NTRS)

    Chang, Rebecca R.; Minck, Robert

    1989-01-01

    Sodium-sulfur batteries were identified as the most likely successor to nickel-hydrogen batteries for space applications. One advantage of the Na/S battery system is that the usable specific energy is two to three times that of nickel-hydrogen batteries. This represents a significant launch cost savings or increased payload mass capabilities. Sodium-sulfur batteries support NASA OAST's proposed Civil Space Technology Initiative goal of a factor of two improvement in spacecraft power system performance, as well as the proposed Spacecraft 2000 initiative. The sodium-sulfur battery operates at between 300 and 400 C, using liquid sodium and sulfur/polysulfide electrodes and solid ceramic electrolyte. The transport of the electrode materials to the surface of the electrolyte is through wicking/capillary forces. These critical transport functions must be demonstrated under actual microgravity conditions before sodium-sulfur batteries can be confidently utilized in space. Ford Aerospace Corporation, under contract to NASA Lewis Research Center, is currently working on the sodium-sulfur battery space flight experiment definition study. The objective is to design the experiment that will demonstrate operation of the sodium-sulfur battery/cell in the space environment with particular emphasis on evaluation of microgravity effects. Experimental payload definitions were completed and preliminary designs of the experiment were defined.

  5. Implicit nucleophilic reagents in the sulfur dioxide-amine system. Sulfur trioxide treatment of azomethines

    SciTech Connect

    Bodrikov, I.V.; Krasnov, V.L.; Matyukov, E.V.; Chernov, A.N.; Verin, I.A.

    1988-03-20

    It was shown by x-ray crystallographic analysis that the products form the reaction of azomethines with the sulfur dioxide-methylamine system are methylammonium 1-aryl-1-(arylamino)methanesulfonates. In aqueous solutions of the latter the amine fragment is redistributed with the formation of arylammonium 1-aryl-1-(arylamino)methanesulfonates. It was established that all the obtained salts are in equilibrium with the azomethines in solutions. The form of the nucleophile taking part in the reaction with the azomethine is suggested on the basis of the data from the PMR spectra of the methylamine-sulfur dioxide system. It was established that in water at room temperature and, particularly, with acid catalysis the compounds undergo fragment transformations which lead finally to redistribution of the covalently bonded amine fragment between the anionic and cationic parts of the salt with the formation of arylammonium 1-aryl-1-(arylamino)methanesulfonates.

  6. New Proteins Involved in Sulfur Trafficking in the Cytoplasm of Allochromatium vinosum*

    PubMed Central

    Stockdreher, Yvonne; Sturm, Marga; Josten, Michaele; Sahl, Hans-Georg; Dobler, Nadine; Zigann, Renate; Dahl, Christiane

    2014-01-01

    The formation of periplasmic sulfur globules is an intermediate step during the oxidation of reduced sulfur compounds in various sulfur-oxidizing microorganisms. The mechanism of how this sulfur is activated and crosses the cytoplasmic membrane for further oxidation to sulfite by the dissimilatory reductase DsrAB is incompletely understood, but it has been well documented that the pathway involves sulfur trafficking mediated by sulfur-carrying proteins. So far sulfur transfer from DsrEFH to DsrC has been established. Persulfurated DsrC very probably serves as a direct substrate for DsrAB. Here, we introduce further important players in oxidative sulfur metabolism; the proteins Rhd_2599, TusA, and DsrE2 are strictly conserved in the Chromatiaceae, Chlorobiaceae, and Acidithiobacillaceae families of sulfur-oxidizing bacteria and are linked to genes encoding complexes involved in sulfur oxidation (Dsr or Hdr) in the latter two. Here we show via relative quantitative real-time PCR and microarray analysis an increase of mRNA levels under sulfur-oxidizing conditions for rhd_2599, tusA, and dsrE2 in Allochromatium vinosum. Transcriptomic patterns for the three genes match those of major genes for the sulfur-oxidizing machinery rather than those involved in biosynthesis of sulfur-containing biomolecules. TusA appears to be one of the major proteins in A. vinosum. A rhd_2599-tusA-dsrE2-deficient mutant strain, although not viable in liquid culture, was clearly sulfur oxidation negative upon growth on solid media containing sulfide. Rhd_2599, TusA, and DsrE2 bind sulfur atoms via conserved cysteine residues, and experimental evidence is provided for the transfer of sulfur between these proteins as well as to DsrEFH and DsrC. PMID:24648525

  7. Genetic engineering of sulfur-degrading Sulfolobus

    SciTech Connect

    Ho, N.W.Y. . Lab. of Renewable Resources Engineering)

    1991-01-01

    Recent studies have shown that some microorganisms can play a significant role in removing the sulfur compound from coal. Sulfolobus acidocaldarius and related species are such microorganisms. The objective of this project is to develop a genetic transformation system for Sulfolobus species so that they could become the ideal host to overproduce homologous and heterologous enzymes that are most effective for the removal of sulfur from coal, particularly organic sulfur. Last quarter, we have identified three chemicals that can inhibit the growth of S. Acidocaldarius. These chemicals can be part of the selection system for the development of a transformation system for S. acidocaldarius. Due to the fact that Sulfolobus shibatae B12 becomes increasingly more attractive as a host for housing genes encoding desulfurization enzymes, in this period we also studied the affect of these three chemicals to growth of S. shibatae B12. We found that S. shibatae B12 is also sensitive to these chemicals. This quarter we succeeded in the isolation and purification of the double-stranded DNA virus from S. shibatae B12. Furthermore, the individual EcoRI and BamH1 fragments of the virus have also been cloned into pUC19 plasmid. These plasmids will be used for the construction of the final E. coli-Sulfolobus shuttle vector. 5 Flurouracil (5FU) is one of the chemicals that inhibit growth of Sulfolobus. Resistance strain of S. acidocaldarius to 5FU has also been isolated. DNA from the 5FU resistance strain has also been isolated. 2 figs.

  8. Catalyst for elemental sulfur recovery process

    DOEpatents

    Flytzani-Stephanopoulos, M.; Liu, W.

    1995-01-24

    A catalytic reduction process is described for the direct recovery of elemental sulfur from various SO[sub 2]-containing industrial gas streams. The catalytic process provides high activity and selectivity, as well as stability in the reaction atmosphere, for the reduction of SO[sub 2] to elemental sulfur product with carbon monoxide or other reducing gases. The reaction of sulfur dioxide and reducing gas takes place over a metal oxide composite catalyst having one of the following empirical formulas: [(FO[sub 2])[sub 1[minus]n](RO)[sub n

  9. Sulfuric acid/hydrogen peroxide rinsing study

    SciTech Connect

    Clews, P.J.; Nelson, G.C.; Matlock, C.A.

    1995-12-01

    Sulfuric acid hydrogen peroxide mixtures (SPM) are commonly used in the semiconductor industry to remove organic contaminants from wafer surfaces. This viscous solution is very difficult to rinse off water surfaces. Various rinsing conditions were tested and the resulting residual acid left on the water surface was measured. Particle growth resulting from incomplete rinse is correlated with the amount of sulfur on the wafer surface measured by Time of Flight Secondary Ion Mass Spectroscopy (TOF-SIMS). The amount of sulfur on the wafer structure after the rinse step is strongly affected by the wafer film type and contact angle prior to the SPM clean.

  10. Viscosity of liquid sulfur under high pressure

    NASA Astrophysics Data System (ADS)

    Terasaki, Hidenori; Kato, T.; Funakoshi, K.; Suzuki, A.; Urakawa, S.

    2004-03-01

    The viscosity of liquid sulfur up to 9.7 GPa and 1067 K was measured using the in situ x-ray radiography falling sphere method. The viscosity coefficients were found to range from 0.11 to 0.69 Pa s, and decreased continuously with increasing pressure under approximately constant homologous temperature conditions. The observed viscosity variation suggests that a gradual structural change occurs in liquid sulfur with pressure up to 10 GPa. The {\\mathrm {L\\mbox {--}L'}} transition in liquid sulfur proposed by Brazhkin et al (1991 Phys. Lett. A 154 413) from thermobaric measurements has not been confirmed by the present viscometry.

  11. Sodium-sulfur battery with glass electrolyte

    SciTech Connect

    Kistrup, H.; Klaus von Benda, B.K.

    1980-10-28

    A sodium-sulfur battery is described in which the sulfur or sulfur-containing positive electrode material is contained in a number of sealed tubes made from a sodium ion-conducting glass electrolyte. The tubes are placed and electrically conducted in parallel and immersed in the sodium constituting the negative electrode. Each of the capillary tubes contains a sealed-in electrical contact wire which passes through an appropriate closure plate to constitute the positive pole of the battery. A number of embodiments is described. The invention also describes the method of construction of the battery.

  12. [Sulfur-oxidizing bacteria of Yavoriv sulfur deposit reservoirs].

    PubMed

    Kulachkovs'kyĭ, O R; Palianytsia, B Iu; Moroz, O M

    2007-01-01

    Eleven pure bacteria cultures, able to oxidize thiosulfate during growth at pH 7.0-9.4, were isolated from surface layers of Yavoriv sulfur deposit open pit waters. Two cultures proved to be obligate aerobes, but nine cultures performed anaerobic respiration using nitrite, N2O (5 cultures) or only nitrite (4 cultures) as terminal electron acceptors. The growth of all cultures at 22 and 28 degrees C and growth absence at 35, 42 and 55 degrees C was established. All the bacteria are obligate chemolithoauthotrophs, because after cultivation with thiosulfate in the presence ofbiotin, yeast extract, formiate, succinate, arabinose, glucose, fructose and sucrose no growth stimulation was observed, heterothropic growth of any culture was not shown. As to their morphology the cells were bacillary, cytoplasmic membrane was surrounded by three-layer cell wall typical of gram negative bacteria intracellular inclusions, nucleoid, ribosomes and polysomes were also available. On the basis of obtained physiological and morphological characteristics the isolated bacteria cultures were referred to a group of neutrophiles, representatives of genus Thiobacillus, in particular to obligate chemolithoauthotrophs. PMID:18380178

  13. Microphysical simulations of sulfur burdens from stratospheric sulfur geoengineering

    NASA Astrophysics Data System (ADS)

    English, J. M.; Toon, O. B.; Mills, M. J.

    2012-05-01

    Recent microphysical studies suggest that geoengineering by continuous stratospheric injection of SO2 gas may be limited by the growth of the aerosols. We study the efficacy of SO2, H2SO4 and aerosol injections on aerosol mass and optical depth using a three-dimensional general circulation model with sulfur chemistry and sectional aerosol microphysics (WACCM/CARMA). We find increasing injection rates of SO2 in a narrow band around the equator to have limited efficacy while broadening the injecting zone as well as injecting particles instead of SO2 gas increases the sulfate burden for a given injection rate, in agreement with previous work. We find that injecting H2SO4 gas instead of SO2 does not discernibly alter sulfate size or mass, in contrast with a previous study using a plume model with a microphysical model. However, the physics and chemistry in aircraft plumes, which are smaller than climate model grid cells, need to be more carefully considered. We also find significant perturbations to tropospheric aerosol for all injections studied, particularly in the upper troposphere and near the poles, where sulfate burden increases by up to 100 times. This enhanced burden could have implications for tropospheric radiative forcing and chemistry. These results highlight the need to mitigate greenhouse gas emissions rather than attempt to cool the planet through geoengineering, and to further study geoengineering before it can be seriously considered as a climate intervention option.

  14. Sulfur to nitrogen ratios in Ponderosa pine as bioindicators of foliar sulfur loading from air pollution

    SciTech Connect

    Johns, C.

    1984-01-01

    The objective of the research was to investigate the potential of foliar S:N ratios in Ponderosa pine as bioindicators of foliar sulfur loading in areas of long-term exposure to low levels of sulfurous air pollutants. First it was necessary to document seasonal variation in S:N ratios in trees not exposed to air pollution. Fifteen Ponderosa pines were selected at a site remote from urban and industrial sources of air pollution and the trees sampled at 18 intervals over a 15 month study period. Significant differences in sulfur and nitrogen concentrations occurred among the five needle age groups within most collections. One-year-old needles contained significantly more sulfur than other needles. Current-year needles contained more nitrogen than the three and four-year-old needles. Within each foliar age class significant differences in total sulfur content and S:N ratios occurred throughout the season. Sulfur concentrations and S:N r

  15. A Carbon-Sulfur Hybrid with Pomegranate-like Structure for Lithium-Sulfur Batteries.

    PubMed

    Shi, Yanting; Lv, Wei; Niu, Shuzhang; He, Yanbing; Zhou, Guangmin; Chen, Guohua; Li, Baohua; Yang, Quan-Hong; Kang, Feiyu

    2016-05-01

    A carbon-sulfur hybrid with pomegranate-like core-shell structure, which demonstrates a high rate performance and relatively high cyclic stability, is obtained through carbonization of a carbon precursor in the presence of a sulfur precursor (FeS2 ) and a following oxidation of FeS2 to sulfur by HNO3 . Such a structure effectively protects the sulfur and leaves enough buffer space after Fe(3+) removal and, at the same time, has an interconnected conductive network. The capacity of the obtained hybrid is 450 mA h g(-1) under the current density of 5 C. This work provides a simple strategy to design and prepare various high-performance carbon-sulfur hybrids for lithium-sulfur batteries. PMID:26918663

  16. Quaternary Marine Sulfur Cycle Dynamics

    NASA Astrophysics Data System (ADS)

    Markovic, S.; Paytan, A.; Wortmann, U. G.

    2011-12-01

    Published data show a -0.8% change in marine sulfate δ34S ratios in the past 2 Ma. Prior to this period it was stable at ~ 22% for ~ 50Ma since the Eocene. Compared to the residence time of sulfate (>10 Ma) the observed change is large and implies a major disturbance of the marine sulfur cycle. However, the cause of the disturbance, as well as the timing of its onset are poorly constrained. Here we present a new set of δ34S ratios of marine sulfate for the last 3 Ma with a temporal resolution of ~300ka, which shows a linear decline from 22 to ~21% in the past 1.75Ma. This may represent a change in volcanic and hydrothermal activity, pyrite burial or erosion and weathering of exposed evaporites and sulfides, which are the main processes affecting sulfate δ34S. However, during this period there is no geological evidence for exceptional volcanic and hydrothermal activity and consequently, the observed negative shift reflects either a change in isotopic composition and volume of erosional input of sulfate to the ocean, or a decrease in pyrite burial. The isotopic composition of the input flux depends on the relative proportion of sulfide vs. sulfate weathering. Sedimentary sulfides are mostly concentrated in organic rich sediments on continental shelves. Existing sea level records suggest periodic sea level drops during glacial stages related to the formation of ice sheets. This could affect sulfur cycling in two ways: a) exposure to surface weathering and erosion agents of large parts of continental shelves increased global sulfide oxidation and thus the input flux of sulfate to the ocean and/or b) the reduction of shelf areas resulted in decreased pyrite burial. We explore the effects of these changes with a simple box model. The modeling results indicate that the observed isotopic shift requires a 150% increase of pyrite weathering or a 90% reduction of pyrite burial over the past 1.75Ma. When both of these processes change in concert the same effect is produced with the doubling of pyrite weathering and 50% decrease of pyrite burial. As pyrite burial and organic matter burial are intimately linked, a drastic decrease in pyrite burial should leave its mark in the carbon isotopic record which shows no evidence of a major change in carbon cycling. We thus propose that increased sulfide weathering, either from subaerial exposure, or as a result of increased winnowing might be the principal cause of the negative δ34S shift in the Quaternary.

  17. Medusa: a sample preconcentration and GC/MS detector system for in situ measurements of atmospheric trace halocarbons, hydrocarbons, and sulfur compounds.

    PubMed

    Miller, Benjamin R; Weiss, Ray F; Salameh, Peter K; Tanhua, Toste; Greally, Brian R; Mühle, Jens; Simmonds, Peter G

    2008-03-01

    Significant changes have occurred in the anthropogenic emissions of many compounds related to the Kyoto and Montreal Protocols within the past 20 years and many of their atmospheric abundances have responded dramatically. Additionally, there are a number of related natural compounds with underdetermined source or sink budgets. A new instrument, Medusa, was developed to make the high frequency in situ measurements required for the determination of the atmospheric lifetimes and emissions of these compounds. This automated system measures a wide range of halocarbons, hydrocarbons, and sulfur compounds involved in ozone depletion and/or climate forcing, from the very volatile perfluorocarbons (PFCs, e.g., CF(4) and CH(3)CF(3)) and hydrofluorocarbons (HFCs, e.g., CH(3)CF(3)) to the higher-boiling point solvents (such as CH(3)Cl(3) and CCl(2)=CCl(2)) and CHBr(3). A network of Medusa systems worldwide provides 12 in situ ambient air measurements per day of more than 38 compounds of part per trillion mole fractions and precisions up to 0.1% RSD at the five remote field stations operated by the Advanced Global Atmospheric Gases Experiment (AGAGE). This custom system couples gas chromatography/mass spectrometry (GC/MSD) with a novel scheme for cryogen-free low-temperature preconcentration (-165 degrees C) of analytes from 2 L samples in a two-trap process using HayeSep D adsorbent. PMID:18232668

  18. Process for the separation of sulfur oxides from a gaseous mixture containing sulfur oxides and oxygen

    SciTech Connect

    Derosset, A.J.; Ginger, E.A.

    1980-12-23

    An improved process for the separation of sulfur oxides from a gaseous mixture containing sulfur oxides and oxygen is disclosed. The gaseous mixture is contacted with a solid sulfur oxide acceptor comprising copper, copper oxide, or a mixture thereof dispersed on a carrier material in combination with a platinum group metal component and a component selected from the group consisting of rhenium, germanium and tin.

  19. Mass-independent sulfur of inclusions in diamond and sulfur recycling on early Earth.

    PubMed

    Farquhar, J; Wing, B A; McKeegan, K D; Harris, J W; Cartigny, P; Thiemens, M H

    2002-12-20

    Populations of sulfide inclusions in diamonds from the Orapa kimberlite pipe in the Kaapvaal-Zimbabwe craton, Botswana, preserve mass-independent sulfur isotope fractionations. The data indicate that material was transferred from the atmosphere to the mantle in the Archean. The data also imply that sulfur is not well mixed in the diamond source regions, allowing for reconstruction of the Archean sulfur cycle and possibly offering insight into the nature of mantle convection through time. PMID:12493909

  20. 46 CFR 151.50-84 - Sulfur dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Sulfur dioxide. 151.50-84 Section 151.50-84 Shipping... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-84 Sulfur dioxide. (a) Sulfur... respiratory protective device that protects the wearer against sulfur dioxide vapors and provides...

  1. 46 CFR 151.50-84 - Sulfur dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Sulfur dioxide. 151.50-84 Section 151.50-84 Shipping... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-84 Sulfur dioxide. (a) Sulfur... respiratory protective device that protects the wearer against sulfur dioxide vapors and provides...

  2. 46 CFR 151.50-84 - Sulfur dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Sulfur dioxide. 151.50-84 Section 151.50-84 Shipping... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-84 Sulfur dioxide. (a) Sulfur... respiratory protective device that protects the wearer against sulfur dioxide vapors and provides...

  3. 46 CFR 151.50-84 - Sulfur dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Sulfur dioxide. 151.50-84 Section 151.50-84 Shipping... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-84 Sulfur dioxide. (a) Sulfur... respiratory protective device that protects the wearer against sulfur dioxide vapors and provides...

  4. 46 CFR 151.50-21 - Sulfuric acid.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Sulfuric acid. 151.50-21 Section 151.50-21 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-21 Sulfuric acid. (a) How sulfuric acid may be carried. (1) Sulfuric acid...

  5. CONSTRUCTION OF A PROTOTYPE SULFURIC ACID MIST MONITOR

    EPA Science Inventory

    A prototype sulfuric acid mist monitor has been constructed for the purpose of detecting sulfuric acid-sulfur trioxide. The monitor utilized the selective condensation method with subsequent determination of sulfuric acid by measuring the conductivity of an aqueous isopropanol so...

  6. Heterogeneous Photochemical Oxidation of Sulfur Dioxide

    NASA Astrophysics Data System (ADS)

    El-Zanan, H. S.; Stockwell, W. R.

    2007-12-01

    The gas phase oxidation of sulfur dioxide by the hydroxyl radical is a significant source of sulfate aerosol in the troposphere and stratosphere. Stockwell and Calvert (1983) performed fifteen chamber experiments where mixtures of HONO, NO, NO2, H2O, SO2 and CO were photolyzed in synthetic air or in nitrogen containing approximately 50 ppm oxygen. They found that the atmospheric oxidation of SO2 by hydroxyl radical was a chain process that occurs through the production of an HO2 radical followed by reaction with NO to reproduce HO. We have reanalyzed this dataset and we have found that a very large amount of the observed SO2 oxidation (70.0 ± 9.1 %) is not explained through the HO + SO2 reaction alone. The Regional Atmospheric Chemistry Mechanism (RACM2) was used to investigate additional chemical pathways for the oxidation of SO2. A mechanism consisting of photochemical heterogeneous reactions is proposed to account for the observed additional sulfur dioxide oxidation not accounted for by gas phase oxidation. The analysis showed that the measured time dependent SO2, CO2 and nitrogenous compound concentrations could be simulated by the photochemical heterogeneous mechanism in conjunction with the RACM2 mechanism.

  7. Surface sulfur measurements on stratospheric particles

    NASA Technical Reports Server (NTRS)

    Mackinnon, I. D. R.; Mogk, D. W.

    1985-01-01

    The surface chemistries of three particulate samples collected from the lower stratosphere have been determined using a Scanning Auger Microprobe (SAM). These samples are typical of the most abundant natural and anthropogenic particles observed within the stratosphere in the greater-than-2-micron diameter size fraction. Succsessive sputtering and analysis below the first few adsorbed monolayers of all particles shows the presence of a thin (less than 150A) sulfur layer. These sulfur regions probably formed by surface reaction of sulfur-rich aerosols with each particle within the stratosphere. Settling rate calculations show that a typical sphere (10-micron diameter) may reside within the aerosol layer for 20 days and thus provide a qualitative guide to surface sulfur reaction rates.

  8. Environmental behavior and analysis of agricultural sulfur.

    PubMed

    Griffith, Corey M; Woodrow, James E; Seiber, James N

    2015-11-01

    Sulfur has been widely used for centuries as a staple for pest and disease management in agriculture. Presently, it is the largest-volume pesticide in use worldwide. This review describes the sources and recovery methods for sulfur, its allotropic forms and properties and its agricultural uses, including development and potential advantages of nanosulfur as a fungicide. Chemical and microbial reactivity, interactions in soil and water and analytical methods for determination in environmental samples and foodstuffs, including inexpensive analytical methods for sulfur residues in wine, beer and other food/beverage substrates, will be reviewed. The toxicology of sulfur towards humans and agriculturally important fungi is included, with some restrictions on use to promote safety. The review concludes with areas for which more research is warranted. PMID:26108794

  9. Sulfur Dioxide variability in the Venus Atmosphere

    NASA Astrophysics Data System (ADS)

    Vandaele, A. C.; Korablev, O.; Mahieux, A.; Wilquet, V.; Chamberlain, S.; Belayev, D.; Encrenaz, Th.; Esposito, L.; Jessup, K. L.; Lefèvre, F.; Limaye, S.; Marcq, E.; Mils, F.; Parkinson, C.; Sandor, B.; Stolzenbach, A.; Wilson, C.

    2015-10-01

    Recent observations of sulfur oxides (SO2, SO, OCS, and H2 SO4) in Venus' mesosphere have generated controversy and great interest in the scientific community. These observations revealed u nexpected spatial patterns and spatial/temporal variability that have not been satisfactorily explained by models. Particularly intriguing are the layer of enhanced gas-phase SO2 and SO in the upper mesosphere, and variability in the maximum observed SO2 a bundance and the equator -to-pole SO2 abundance gradient, seemingly on multi-year cycles, that is not uniquely linked to local time variations. Sulfur oxide chemistry on Venus is closely linked to the global-scale cloud and haze layers, which are composed primarily of concentrated sulfuric acid. Consequently, sulfur oxide observations provide important insight into the ongoing chemical evolution of Venus' atmosphere, atmospheric dynamics, and possible volcanism.

  10. 46 CFR 148.315 - Sulfur.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... deck sweepings must be disposed of pursuant to 33 CFR 151.55 through 151.77. (c) A cargo space that... lump or coarse grain powder sulfur only. Fine-grained powder (“flowers of sulfur”) may not...

  11. 46 CFR 148.315 - Sulfur.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... deck sweepings must be disposed of pursuant to 33 CFR 151.55 through 151.77. (c) A cargo space that... lump or coarse grain powder sulfur only. Fine-grained powder (“flowers of sulfur”) may not...

  12. 46 CFR 148.315 - Sulfur.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... deck sweepings must be disposed of pursuant to 33 CFR 151.55 through 151.77. (c) A cargo space that... lump or coarse grain powder sulfur only. Fine-grained powder (“flowers of sulfur”) may not...

  13. Sodium-sulfur batteries for satellite applications

    NASA Astrophysics Data System (ADS)

    Wolanczyk, Stephan M.; Vukson, Stephen P.

    1990-04-01

    A development status evaluation is presented for the USAF's various efforts to advance sodium-sulfur battery technology as a basis for GEO and LEO satellite energy storage systems. These efforts encompass the High Energy Density Rechargeable Battery program, the LEO Sodium-Sulfur Cell Development program, the Improved Sodium-Sulfur Electrolyte program, and the Lightweight Aerospace Battery (LAB) program. An especially taxing requirement for batteries of this type is the substantial number of charge/discharge cycles typical of LEO satellite applications. The LAB program, which will extend to 1993, is intended to develop a bipolar, flat-plate sodium-sulfur satellite battery with 7-10 year service life in LEO and 15 years in GEO.

  14. Effect of Non-Surgical Periodontal Therapy on the Concentration of Volatile Sulfur Compound in Mouth Air of a Group of Nigerian Young Adults

    PubMed Central

    Ehizele, AO; Akhionbare, O

    2013-01-01

    Background: The major goal of non-surgical periodontal therapy is to reduce or eliminate the subgingival pathogenic microbial flora that is known to be associated with volatile sulfur compounds (VSC). Aim: The aim of this study was, therefore, to determine the effect of non-surgical periodontal therapy on the concentration of VSC in mouth air of young adults. Subjects and Methods: Four hundred subjects, grouped into two based on the absence or presence of periodontal diseases, were involved in this study. Basic periodontal examination was used for the grouping. The measurement of the concentration of the VSC in the mouth air of the subjects was done objectively, using the Halimeter, before and after the therapy, and at recall visits 2 weeks and 6 weeks after therapy. Chi-square and Paired t-test were used to find statistical significance. Results: The results revealed that at baseline, 78.7% (48/61) of the subjects who had VSC concentration more than 250 parts per billion (ppb) were from the group with periodontal disease. Immediately after non-surgical periodontal therapy, only 8.5% (17/200) of the subjects with periodontal disease had VSC concentration of more than 250 ppb while all the subjects with no periodontal disease had VSC concentration less than 181 ppb. The same pattern of reduction in the concentration of the VSC and improvement in oral hygiene was also obtained 2 weeks and 6 weeks after therapy. Conclusion: It can be concluded that non-surgical periodontal therapy brought about reduction in the concentration of volatile sulfur compounds in mouth air of young adults. PMID:24116328

  15. Large fractions of CO2-fixing microorganisms in pristine limestone aquifers appear to be involved in the oxidation of reduced sulfur and nitrogen compounds.

    PubMed

    Herrmann, Martina; Rusznyák, Anna; Akob, Denise M; Schulze, Isabel; Opitz, Sebastian; Totsche, Kai Uwe; Küsel, Kirsten

    2015-04-01

    The traditional view of the dependency of subsurface environments on surface-derived allochthonous carbon inputs is challenged by increasing evidence for the role of lithoautotrophy in aquifer carbon flow. We linked information on autotrophy (Calvin-Benson-Bassham cycle) with that from total microbial community analysis in groundwater at two superimposed-upper and lower-limestone groundwater reservoirs (aquifers). Quantitative PCR revealed that up to 17% of the microbial population had the genetic potential to fix CO2 via the Calvin cycle, with abundances of cbbM and cbbL genes, encoding RubisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) forms I and II, ranging from 1.14 × 10(3) to 6 × 10(6) genes liter(-1) over a 2-year period. The structure of the active microbial communities based on 16S rRNA transcripts differed between the two aquifers, with a larger fraction of heterotrophic, facultative anaerobic, soil-related groups in the oxygen-deficient upper aquifer. Most identified CO2-assimilating phylogenetic groups appeared to be involved in the oxidation of sulfur or nitrogen compounds and harbored both RubisCO forms I and II, allowing efficient CO2 fixation in environments with strong oxygen and CO2 fluctuations. The genera Sulfuricella and Nitrosomonas were represented by read fractions of up to 78 and 33%, respectively, within the cbbM and cbbL transcript pool and accounted for 5.6 and 3.8% of 16S rRNA sequence reads, respectively, in the lower aquifer. Our results indicate that a large fraction of bacteria in pristine limestone aquifers has the genetic potential for autotrophic CO2 fixation, with energy most likely provided by the oxidation of reduced sulfur and nitrogen compounds. PMID:25616797

  16. Large Fractions of CO2-Fixing Microorganisms in Pristine Limestone Aquifers Appear To Be Involved in the Oxidation of Reduced Sulfur and Nitrogen Compounds

    PubMed Central

    Herrmann, Martina; Rusznyák, Anna; Akob, Denise M.; Schulze, Isabel; Opitz, Sebastian; Totsche, Kai Uwe

    2015-01-01

    The traditional view of the dependency of subsurface environments on surface-derived allochthonous carbon inputs is challenged by increasing evidence for the role of lithoautotrophy in aquifer carbon flow. We linked information on autotrophy (Calvin-Benson-Bassham cycle) with that from total microbial community analysis in groundwater at two superimposed—upper and lower—limestone groundwater reservoirs (aquifers). Quantitative PCR revealed that up to 17% of the microbial population had the genetic potential to fix CO2 via the Calvin cycle, with abundances of cbbM and cbbL genes, encoding RubisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) forms I and II, ranging from 1.14 × 103 to 6 × 106 genes liter−1 over a 2-year period. The structure of the active microbial communities based on 16S rRNA transcripts differed between the two aquifers, with a larger fraction of heterotrophic, facultative anaerobic, soil-related groups in the oxygen-deficient upper aquifer. Most identified CO2-assimilating phylogenetic groups appeared to be involved in the oxidation of sulfur or nitrogen compounds and harbored both RubisCO forms I and II, allowing efficient CO2 fixation in environments with strong oxygen and CO2 fluctuations. The genera Sulfuricella and Nitrosomonas were represented by read fractions of up to 78 and 33%, respectively, within the cbbM and cbbL transcript pool and accounted for 5.6 and 3.8% of 16S rRNA sequence reads, respectively, in the lower aquifer. Our results indicate that a large fraction of bacteria in pristine limestone aquifers has the genetic potential for autotrophic CO2 fixation, with energy most likely provided by the oxidation of reduced sulfur and nitrogen compounds. PMID:25616797

  17. Large fractions of CO2-fixing microorganisms in pristine limestone aquifers appear to be involved in the oxidation of reduced sulfur and nitrogen compounds

    USGS Publications Warehouse

    Herrmann, Martina; Rusznyák, Anna; Akob, Denise M.; Schulze, Isabel; Opitz, Sebastian; Totsche, Kai Uwe; Küsel, Kirsten

    2015-01-01

    The traditional view of the dependency of subsurface environments on surface-derived allochthonous carbon inputs is challenged by increasing evidence for the role of lithoautotrophy in aquifer carbon flow. We linked information on autotrophy (Calvin-Benson-Bassham cycle) with that from total microbial community analysis in groundwater at two superimposed—upper and lower—limestone groundwater reservoirs (aquifers). Quantitative PCR revealed that up to 17% of the microbial population had the genetic potential to fix CO2 via the Calvin cycle, with abundances of cbbM and cbbL genes, encoding RubisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) forms I and II, ranging from 1.14 × 103 to 6 × 106 genes liter−1 over a 2-year period. The structure of the active microbial communities based on 16S rRNA transcripts differed between the two aquifers, with a larger fraction of heterotrophic, facultative anaerobic, soil-related groups in the oxygen-deficient upper aquifer. Most identified CO2-assimilating phylogenetic groups appeared to be involved in the oxidation of sulfur or nitrogen compounds and harbored both RubisCO forms I and II, allowing efficient CO2 fixation in environments with strong oxygen and CO2 fluctuations. The genera Sulfuricellaand Nitrosomonas were represented by read fractions of up to 78 and 33%, respectively, within the cbbM and cbbL transcript pool and accounted for 5.6 and 3.8% of 16S rRNA sequence reads, respectively, in the lower aquifer. Our results indicate that a large fraction of bacteria in pristine limestone aquifers has the genetic potential for autotrophic CO2 fixation, with energy most likely provided by the oxidation of reduced sulfur and nitrogen compounds.

  18. A Comparative Quantitative Proteomic Study Identifies New Proteins Relevant for Sulfur Oxidation in the Purple Sulfur Bacterium Allochromatium vinosum

    PubMed Central

    Weissgerber, Thomas; Sylvester, Marc; Kröninger, Lena

    2014-01-01

    In the present study, we compared the proteome response of Allochromatium vinosum when growing photoautotrophically in the presence of sulfide, thiosulfate, and elemental sulfur with the proteome response when the organism was growing photoheterotrophically on malate. Applying tandem mass tag analysis as well as two-dimensional (2D) PAGE, we detected 1,955 of the 3,302 predicted proteins by identification of at least two peptides (59.2%) and quantified 1,848 of the identified proteins. Altered relative protein amounts (≥1.5-fold) were observed for 385 proteins, corresponding to 20.8% of the quantified A. vinosum proteome. A significant number of the proteins exhibiting strongly enhanced relative protein levels in the presence of reduced sulfur compounds are well documented essential players during oxidative sulfur metabolism, e.g., the dissimilatory sulfite reductase DsrAB. Changes in protein levels generally matched those observed for the respective relative mRNA levels in a previous study and allowed identification of new genes/proteins participating in oxidative sulfur metabolism. One gene cluster (hyd; Alvin_2036-Alvin_2040) and one hypothetical protein (Alvin_2107) exhibiting strong responses on both the transcriptome and proteome levels were chosen for gene inactivation and phenotypic analyses of the respective mutant strains, which verified the importance of the so-called Isp hydrogenase supercomplex for efficient oxidation of sulfide and a crucial role of Alvin_2107 for the oxidation of sulfur stored in sulfur globules to sulfite. In addition, we analyzed the sulfur globule proteome and identified a new sulfur globule protein (SgpD; Alvin_2515). PMID:24487535

  19. Effects of variation of dietary sulfur on movement of sulfur in sheep rumen

    SciTech Connect

    Kandylis, K.; Bray, A.C.

    1987-01-01

    Effects of variations in dietary sulfur on rumen sulfur dynamics were studied under steady state conditions. In the first experimental period, three sheep were given 33.3 g of a pelleted diet hourly containing 1.59 g sulfur/kg (low) and in the second period the sulfur content was increased to 3.21 g/kg (high) by the addition of sodium sulfate. The daily sulfur intake was 1.158 g on the low sulfur diet and .545 g of this passed from the rumen in protein, .614 g was calculated to be absorbed from the rumen as sulfide, and .052 g was estimated to be recycled to the rumen. For sheep with daily intakes of 2.317 g sulfur, 1.212 g passed from the rumen in protein, 1.078 g was absorbed from the rumen, and .093 g was estimated to be recycled. It was estimated that 127 and 165 g microbial protein were synthesized/kg organic matter truly digested in the rumen for low and high sulfur diets, respectively. A simple model using simultaneous equations was proposed to describe rumen sulfur metabolism.

  20. Definition of Non-Conventional Sulfur Utilization in Western Kazakhstan for Sulfur Concrete (Phase 1)

    SciTech Connect

    Kalb, Paul

    2007-05-31

    Battelle received a contract from Agip-KCO, on behalf a consortium of international oil and gas companies with exploration rights in the North Caspian Sea, Kazakhstan. The objective of the work was to identify and help develop new techniques for sulfur concrete products from waste, by-product sulfur that will be generated in large quantitites as drilling operations begin in the near future. BNL has significant expertise in the development and use of sulfur concrete products and has direct experience collaborating with the Russian and Kazakh partners that participated. Feasibility testing was successfully conducted for a new process to produce cost-effective sulfur polymer cement that has broad commerical applications.

  1. Sulfur mustard and respiratory diseases.

    PubMed

    Tang, Feng Ru; Loke, Weng Keong

    2012-09-01

    Victims exposed to sulfur mustard (HD) in World War I and Iran-Iraq war, and those suffered occupational or accidental exposure have endured discomfort in the respiratory system at early stages after exposure, and marked general physical deterioration at late stages due to pulmonary fibrosis, bronchiolitis obliterans or lung cancer. At molecule levels, significant changes of cytokines and chemokines in bronchoalveolar lavage and serum, and of selectins (in particular sE-selectin) and soluble Fas ligand in the serum have been reported in recent studies of patients exposed to HD in Iran-Iraq war, suggesting that these molecules may be associated with the pathophysiological development of pulmonary diseases. Experimental studies in rodents have revealed that reactive oxygen and nitrogen species, their product peroxynitrite (ONOO(-)), nitric oxide synthase, glutathione, poly (adenosine diphosphate-ribose) polymerase, activating protein-1 signaling pathway are promising drug targets for preventing HD-induced toxicity, whereas N-acetyl cysteine, tocopherols, melatonin, aprotinin and many other molecules have been proved to be effective in prevention of HD-induced damage to the respiratory system in different animal models. In this paper, we will systemically review clinical and pathophysiological changes of respiratory system in victims exposed to HD in the last century, update clinicians and researchers on the mechanism of HD-induced acute and chronic lung damages, and on the relevant drug targets for future development of antidotes for HD. Further research directions will also be proposed. PMID:22742653

  2. Sodium-sulfur storage battery

    SciTech Connect

    Kazumasa, M.; Asao, K.

    1987-04-28

    A sodium-sulfur storage battery is described comprising: an alpha alumina ring having a longitudinally extending recess therein, a sodium conductive solid electrolyte tube having a longitudinal end disposed in the recess, the end being of smaller cross-section than the recess to define an annular space therebetween, and solder glass disposed in the annular space to join the ring to the tube. The annular space includes a longitudinally inner portion and an enlarged longitudinally outer portion, each portion containing the solder glass, the enlarged outer portion situated at an open longitudinal end of the recess and defining a groove for collecting the solder glass, the glass being positioned in the groove by substantially filling the groove with molten glass, and allowing the molten glass to harden such that no portion of an outer surface of the glass projects beyond an outer edge of the groove. At least a portion of the glass outer surface extends inside of the groove outer edge, the groove having a width in a radial direction in the range of from 0.2 mm to 5.0 mm and a depth in the longitudinal direction in the range of from 0.2 to 10.0 mm.

  3. Copper mercaptides as sulfur dioxide indicators

    DOEpatents

    Eller, Phillip G.; Kubas, Gregory J.

    1979-01-01

    Organophosphine copper(I) mercaptide complexes are useful as convenient and semiquantitative visual sulfur dioxide gas indicators. The air-stable complexes form 1:1 adducts in the presence of low concentrations of sulfur dioxide gas, with an associated color change from nearly colorless to yellow-orange. The mercaptides are made by mixing stoichiometric amounts of the appropriate copper(I) mercaptide and phosphine in an inert organic solvent.

  4. A Cable-Shaped Lithium Sulfur Battery.

    PubMed

    Fang, Xin; Weng, Wei; Ren, Jing; Peng, Huisheng

    2016-01-01

    A carbon nanostructured hybrid fiber is developed by integrating mesoporous carbon and graphene oxide into aligned carbon nanotubes. This hybrid fiber is used as a 1D cathode to fabricate a new cable-shaped lithium-sulfur battery. The fiber cathode exhibits a decent specific capacity and lifespan, which makes the cable-shaped lithium-sulfur battery rank far ahead of other fiber-shaped batteries. PMID:26585740

  5. Recovery of elemental sulfur from sour gas

    SciTech Connect

    Reed, R.L.

    1984-07-31

    Excess heat generated in a thermal reaction zone of a Claus sulfur recovery plant is used, by means of a high boiling point heat transfer medium, to reheat the Claus plant process stream prior to high temperature Claus catalytic conversion, and/or to regenerate Claus catalyst on which sulfur is deposited, or for other functions. In another aspect, low temperature Claus catalytic converters are operated at equivalent pressures during a cycle comprising an adsorption phase, a regeneration phase, and a cooling phase.

  6. Microphysical simulations of sulfur burdens from stratospheric sulfur geoengineering

    NASA Astrophysics Data System (ADS)

    English, J. M.; Toon, O. B.; Mills, M. J.

    2012-01-01

    Recent microphysical studies suggest that geoengineering by continuous stratospheric injection of SO2 gas may be limited by the growth of the aerosols. We study the efficacy of SO2, H2SO4 and aerosol injections on aerosol mass and optical depth using a three-dimensional general circulation model with sulfur chemistry and sectional aerosol microphysics (WACCM/CARMA). We find increasing injection rates of SO2 in a narrow band around the equator to have limited efficacy while broadening the injecting zone as well as injecting particles instead of SO2 gas increases the sulfate burden for a given injection rate, in agreement with previous work. We find that injecting H2SO4 gas instead of SO2 does not discernibly alter sulfate size or mass, in contrast with a previous study using a plume model with a microphysical model. However, the physics and chemistry in aircraft plumes, which are smaller than climate model grid cells, need to be more carefully considered. We find equatorial injections increase aerosol optical depth in the Northern Hemisphere more than the Southern Hemisphere, potentially inducing regional climate changes. We also find significant perturbations to tropospheric aerosol for all injections studied, particularly in the upper troposphere and near the poles, where sulfate burden increases by up to 100 times. This enhanced burden could have implications for tropospheric radiative forcing and chemistry. These results highlight the need to mitigate greenhouse gas emissions through means other than geoengineering, and to further study geoengineering before it can be seriously considered as a climate intervention option.

  7. An Aerosol Condensation Model for Sulfur Trioxide

    SciTech Connect

    Grant, K E

    2008-02-07

    This document describes a model for condensation of sulfuric acid aerosol given an initial concentration and/or source of gaseous sulfur trioxide (e.g. fuming from oleum). The model includes the thermochemical effects on aerosol condensation and air parcel buoyancy. Condensation is assumed to occur heterogeneously onto a preexisting background aerosol distribution. The model development is both a revisiting of research initially presented at the Fall 2001 American Geophysical Union Meeting [1] and a further extension to provide new capabilities for current atmospheric dispersion modeling efforts [2]. Sulfuric acid is one of the most widely used of all industrial chemicals. In 1992, world consumption of sulfuric acid was 145 million metric tons, with 42.4 Mt (mega-tons) consumed in the United States [10]. In 2001, of 37.5 Mt consumed in the U.S., 74% went into producing phosphate fertilizers [11]. Another significant use is in mining industries. Lawuyi and Fingas [7] estimate that, in 1996, 68% of use was for fertilizers and 5.8% was for mining. They note that H{sub 2}SO{sub 4} use has been and should continue to be very stable. In the United States, the elimination of MTBE (methyl tertiary-butyl ether) and the use of ethanol for gasoline production are further increasing the demand for petroleum alkylate. Alkylate producers have a choice of either a hydrofluoric acid or sulfuric acid process. Both processes are widely used today. Concerns, however, over the safety or potential regulation of hydrofluoric acid are likely to result in most of the growth being for the sulfuric acid process, further increasing demand [11]. The implication of sulfuric acid being a pervasive industrial chemical is that transport is also pervasive. Often, this is in the form of oleum tankers, having around 30% free sulfur trioxide. Although sulfuric acid itself is not a volatile substance, fuming sulfuric acid (referred to as oleum) is [7], the volatile product being sulfur trioxide. Sulfate aerosols and mist may form in the atmosphere on tank rupture. From chemical spill data from 1990-1996, Lawuyi02 and Fingas [7] prioritize sulfuric acid as sixth most serious. During this period, they note 155 spills totaling 13 Mt, out of a supply volume of 3700 Mt. Lawuyi and Fingas [7] summarize information on three major sulfuric acid spills. On 12 February 1984, 93 tons of sulfuric acid were spilled when 14 railroad cars derailed near MacTier, Parry Sound, Ontario. On 13 December 1978, 51 railroad cars derailed near Springhill, Nova Scotia. One car, containing 93% sulfuric acid, ruptured, spilling nearly its entire contents. In July 1993, 20 to 50 tons of fuming sulfuric acid spilled at the General Chemical Corp. plant in Richmond, California, a major industrial center near San Francisco. The release occurred when oleum was being loaded into a nonfuming acid railroad tank car that contained only a rupture disk as a safety device. The tank car was overheated and this rupture disk blew. The resulting cloud of sulfuric acid drifted northeast with prevailing winds over a number of populated areas. More than 3,000 people subsequently sought medical attention for burning eyes, coughing, headaches, and nausea. Almost all were treated and released on the day of the spill. By the day after the release, another 5,000 people had sought medical attention. The spill forced the closure of five freeways in the region as well as some Bay Area Rapid Transit System stations. Apart from corrosive toxicity, there is the additional hazard that the reactions of sulfur trioxide and sulfuric acid vapors with water are extremely exothermic [10, 11]. While the vapors are intrinsically denser than air, there is thus the likelihood of strong, warming-induced buoyancy from reactions with ambient water vapor, water-containing aerosol droplets, and wet environmental surface. Nordin [12] relates just such an occurrence following the Richmond, CA spill, with the plume observed to rise to 300 m. For all practical purposes, sulfur trioxide was the constituent released from the heated tank car. The behavior of the resulting plume suggested that initially sulfur trioxide behaved as a dense gas, but the chemical reacted with air humidity, producing sulfuric acid and heat. The heat caused the plume to rise. Eventually the plume cooled, resulting in sulfuric acid descending towards people on the ground. This kind of behavior is not accounted for in the popular gas dispersion models. In the presence of complex terrain, such heat induced buoyancy could enable a sulfur trioxide cloud to leap local drainage boundaries with a single bound. Unless there were insufficient water/humidity to fully react with the SO{sub 3} and H{sub 2}SO{sub 4} on the first ascent, no secondary bounds would be expected, the cloud then behaving as a heavy tracer until sufficiently diluted.

  8. The biology of reactive sulfur species (RSS).

    PubMed

    Gruhlke, Martin C H; Slusarenko, Alan J

    2012-10-01

    Sulfur is an essential and quantitatively important element for living organisms. Plants contain on average approximately 1 g S kg? dry weight (for comparison plants contain approximately 15 g N kg? dry weight). Sulfur is a constituent of many organic molecules, for example amino acids such as cysteine and methionine and the small tripeptide glutathione, but sulfur is also essential in the form of Fe-S clusters for the activity of many enzymes, particularly those involved in redox reactions. Sulfur chemistry is therefore important. In particular, sulfur in the form of thiol groups is central to manifold aspects of metabolism. Because thiol groups are oxidized and reduced easily and reversibly, the redox control of cellular metabolism has become an increasing focus of research. In the same way that oxygen and nitrogen have reactive species (ROS and RNS), sulfur too can form reactive molecular species (RSS), for example when a -SH group is oxidized. Indeed, several redox reactions occur via RSS intermediates. Several naturally occurring S-containing molecules are themselves RSS and because they are physiologically active they make up part of the intrinsic plant defence repertoire against herbivore and pathogen attack. Furthermore, RSS can also be used as redox-active pharmacological tools to study cell metabolism. The aim of this review is to familiarize the general reader with some of the chemical concepts, terminology and biology of selected RSS. PMID:22541352

  9. World copper smelter sulfur balance-1988

    SciTech Connect

    Towle, S.W. )

    1993-01-01

    In 1989, the US Bureau of Mines initiated a contract to gather engineering, operating, and environmental cost data for 1988 for 30 major foreign primary copper smelters in market economy countries. Data were collected for 29 of the designated smelters together with information on applicable environmental regulations. Materials balance data obtained were used with available data for the eight US smelters to determine the approximate extent of copper smelter sulfur emission control in 1988. A broad characterization of the status of sulfur emission control regulation was made. The 37 US and foreign smelters represented roughly 73.2% of world and 89.3% of market economy primary copper production in 1988. The 29 non-US smelters attained 55.3% control of their input sulfur in 1988. Combined with the 90.4% control of US smelters, an aggregate 63.4% sulfur control existed. Roughly 1,951,100 mt of sulfur was emitted from the 37 market economy smelters in 1988. Identifiable SO[sub 2] control regulations covered 72.4% of the 29 foreign smelters, representing 65.5% of smelting capacity. Including US smelters, 78.4% of the major market economy smelters were regulated, representing 73.1% of smelting capacity. Significant changes since 1988 that may increase sulfur emission control are noted.

  10. Sulfur "Concrete" for Lunar Applications - Sublimation Concerns

    NASA Technical Reports Server (NTRS)

    Grugel, Richard N.; Toutanji, Houssam

    2006-01-01

    Melting sulfur and mixing it with an aggregate to form "concrete" is commercially well established and constitutes a material that is particularly well-suited for use in corrosive environments. Discovery of the mineral troilite (FeS) on the moon poses the question of extracting the sulfur for use as a lunar construction material. This would be an attractive alternative to conventional concrete as it does not require water. However, the viability of sulfur concrete in a lunar environment, which is characterized by lack of an atmosphere and extreme temperatures, is not well understood. Here it is assumed that the lunar ore can be mined, refined, and the raw sulfur melded with appropriate lunar regolith to form, for example, bricks. This study evaluates pure sulfur and two sets of small sulfur concrete samples that have been prepared using JSC-1 lunar stimulant and SiO2 powder as aggregate additions. Each set was subjected to extended periods in a vacuum environment to evaluate sublimation issues. Results from these experiments are presented and discussed within the context of the lunar environment.

  11. Improved Chromatographic Techniques for Sulfur Pollutants

    NASA Technical Reports Server (NTRS)

    Hartmann, C. H.

    1971-01-01

    This paper describes several improvements in instrumental techniques for the analysis of low ppb concentrations of sulfur gases using gas chromatography (G.C.). This work has focused on the analytical problem of ambient air monitoring of the two main sulfur gas pollutants, hydrogen sulfide and sulfur dioxide. The most significant technical improvement that will be reported here is the newly developed silica gel column for ppb concentrations of the light sulfur gases (COS, H2S, CS2, SO2, CH3SH). A simplified inlet system will be described which improves reliability of the GC system. The flame photometric detector is used as the means of selectively and sensitively detecting the low concentrations of sulfur gases. Improvements will be described which have yielded better performance than previously reported for this application of the detector. Also included in this paper will be a report of field monitoring using this improved GC system. Reliability and repeatability of performance at the low ppb concentrations of sulfur gases will be demonstrated.

  12. Volcanogenic Sulfur on Earth and Io: Composition and Spectroscopy

    USGS Publications Warehouse

    Kargel, J.S.; Delmelle, P.; Nash, D.B.

    1999-01-01

    The causes of Io's variegated surface, especially the roles of sulfur, and the geochemical history of sulfur compounds on Io are not well understood. Suspecting that minor impurities in sulfur might be important, we have investigated the major and trace element chemistry and spectroscopic reflectance of natural sulfur from a variety of terrestrial volcanic-hydrothermal environments. Evidence suggests that Io may be substantially coated with impure sulfur. On Earth, a few tenths of a percent to a few percent of chalcophile trace elements (e.g., As and Se) comonly occur in sulfur and appear to stabilize material of yellow, brown, orange, and red hues, which may persist even at low temperatures. Percentage levels of chalcophile impurities are reasonably expected to occur on Io in vapor sublimate deposits and flows derived from such deposits. Such impurities join a host of other mechanisms that might explain Io's reds and yellows. Two-tenths to two percent opaque crystalline impurities, particularly pyrite (FeS2), commonly produces green, gray, and black volcanic sulfur on Earth and might explain areas of Io having deposits of these colors. Pyrite produces a broad absorption near 1 ??m that gradually diminishes out to 1.6 ??m - similar but not identical to the spectrum of Io seen in Galileo NIMS data. Percentage amounts of carbonaceous impurities and tens of percent SiO2 (as silicates) also strongly affect the spectral properties of Earth's sulfur. Io's broad absorption between 0.52 and 0.64 ??m remains unexplained by these data but could be due to sodium sulfides, as suggested previously by others, or to As, Se, or other impurities. These impurities and others, such as P and Cl (which could exist on Io's surface in amounts over 1% that of sulfur), greatly alter the molecular structure of molten and solid sulfur. Minor impurities could impact Io's geology, such as the morphology of sulfur lava flows and the ability of sulfur to sustain high relief. We have not found any natural sulfur containing significant Na beyond that attributable to silicate inclusions. In sum, the unique physical-chemical properties of S-rich systems and the strong affinity of certain elements for S may have broad implications for the appearance, spectroscopic interpretation, and geologic processes of Io. Identification of impurities in sulfur may be helpful in tracing the geochemical evolution of surface deposits on Io. Perhaps foretelling of new areas of investigation, Cl has recently been reported in the Io torus (M. Kueppers and N. M. Schneider 1999, Eos Trans.80, 5207), suggesting the presence on Io of either salts, such as halite, or sulfur chlorides. Further evidence of minor iogenic impurities should be sought in Io's neutral cloud and plasma torus as well as in further scrutiny of Io's reflectance spectra. ?? 1999 Academic Press.

  13. Identification of control parameters for the sulfur gas storability with bag sampling methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Air samples containing sulfur compounds are often collected and stored in sample bags prior to analyses. The storage stability of six gaseous sulfur compounds (H2S, CH3SH, DMS, CS2, DMDS and SO2) was compared between two different bag materials (polyvinyl fluoride (PVF) and polyester aluminum (PEA))...

  14. Effect of feeding distiller’s grains on reduced sulfur emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Odorous reduced sulfur compounds are produced during manure decomposition and emitted from confined animal feeding operations. Feeding high-sulfur distiller’s byproducts may increase the emission of these compounds. The objectives of a series of feedlot pen studies was to (i) determine if emission...

  15. Taxing sulfur dioxide emission allowances

    SciTech Connect

    Nelson, G.L. )

    1993-09-15

    The acid rain control program authorized by Title IV of the Clean Air Act Amendments of 1990 (CAAA) was designed to reduce the adverse effects of acid rain by limiting emissions of sulfur dioxide (SO[sub 2]) into the atmosphere. The program is a complex scheme involving the issuance, consumption, holding, and trading of emission allowances for SO[sub 2]. Not surprisingly, electric utilities will face federal income tax issues in connection with the program. Under the emission allowance program, the U.S. Environmental Protection Agency (EPA) will issue emission allowance to owners or operators of certain utility power plants at no cost to the recipients. An emission allowance is an authorization to emit one ton of SO[sub 2] during or after the calendar year for which it is issued. If a utility power plant subject to the program emits SO[sub 2] in excess of its allowances, the owner or operator will be subject to a penalty of $2,000 a ton, and must offset the excess emissions with allowances in the subsequent year. Allowances may be bought and sold. Phase I of the program begins January 1, 1995, and will apply to 110 utility generating units. Phase II takes effect January 1, 2000, and will include most electric utility generating units. EPA will withhold a specified number of allowances for direct sale and auction. The resulting proceeds will be paid to the utilities from which the allowances were withheld. The Internal Revenue Service (IRS) has provided somewhat limited guidance on several tax issues raised by the program. Significant tax issues and the positions articulated by the IRS (if any) are discussed in this article.

  16. Process and apparatus for generating elemental sulfur and re-usable metal oxide from spent metal sulfide sorbents

    DOEpatents

    Ayala, Raul E.; Gal, Eli

    1995-01-01

    A process and apparatus for generating elemental sulfur and re-usable metal oxide from spent metal-sulfur compound. Spent metal-sulfur compound is regenerated to re-usable metal oxide by moving a bed of spent metal-sulfur compound progressively through a single regeneration vessel having a first and second regeneration stage and a third cooling and purging stage. The regeneration is carried out and elemental sulfur is generated in the first stage by introducing a first gas of sulfur dioxide which contains oxygen at a concentration less than the stoichiometric amount required for complete oxidation of the spent metal-sulfur compound. A second gas containing sulfur dioxide and excess oxygen at a concentration sufficient for complete oxidation of the partially spent metal-sulfur compound, is introduced into the second regeneration stage. Gaseous sulfur formed in the first regeneration stage is removed prior to introducing the second gas into the second regeneration stage. An oxygen-containing gas is introduced into the third cooling and purging stage. Except for the gaseous sulfur removed from the first stage, the combined gases derived from the regeneration stages which are generally rich in sulfur dioxide and lean in oxygen, are removed from the regenerator as an off-gas and recycled as the first and second gas into the regenerator. Oxygen concentration is controlled by adding air, oxygen-enriched air or pure oxygen to the recycled off-gas.

  17. Metal-Sulfur Battery Cathodes Based on PAN-Sulfur Composites.

    PubMed

    Wei, Shuya; Ma, Lin; Hendrickson, Kenville E; Tu, Zhengyuan; Archer, Lynden A

    2015-09-23

    Sulfur/polyacrylonitrile composites provide a promising route toward cathode materials that overcome multiple, stubborn technical barriers to high-energy, rechargeable lithium-sulfur (Li-S) cells. Using a facile thermal synthesis procedure in which sulfur and polyacrylonitrile (PAN) are the only reactants, we create a family of sulfur/PAN (SPAN) nanocomposites in which sulfur is maintained as S3/S2 during all stages of the redox process. By entrapping these smaller molecular sulfur species in the cathode through covalent bonding to and physical confinement in a conductive host, these materials are shown to completely eliminate polysulfide dissolution and shuttling between lithium anode and sulfur cathode. We also show that, in the absence of any of the usual salt additives required to stabilize the anode in traditional Li-S cells, Li-SPAN cells cycle trouble free and at high Coulombic efficiencies in simple carbonate electrolytes. Electrochemical and spectroscopic analysis of the SPAN cathodes at various stages of charge and discharge further show a full and reversible reduction and oxidation between elemental sulfur and Li-ions in the electrolyte to produce Li2S as the only discharge product over hundreds of cycles of charge and discharge at fixed current densities. PMID:26325146

  18. Fibrous hybrid of graphene and sulfur nanocrystals for high-performance lithium-sulfur batteries.

    PubMed

    Zhou, Guangmin; Yin, Li-Chang; Wang, Da-Wei; Li, Lu; Pei, Songfeng; Gentle, Ian Ross; Li, Feng; Cheng, Hui-Ming

    2013-06-25

    Graphene-sulfur (G-S) hybrid materials with sulfur nanocrystals anchored on interconnected fibrous graphene are obtained by a facile one-pot strategy using a sulfur/carbon disulfide/alcohol mixed solution. The reduction of graphene oxide and the formation/binding of sulfur nanocrystals were integrated. The G-S hybrids exhibit a highly porous network structure constructed by fibrous graphene, many electrically conducting pathways, and easily tunable sulfur content, which can be cut and pressed into pellets to be directly used as lithium-sulfur battery cathodes without using a metal current-collector, binder, and conductive additive. The porous network and sulfur nanocrystals enable rapid ion transport and short Li(+) diffusion distance, the interconnected fibrous graphene provides highly conductive electron transport pathways, and the oxygen-containing (mainly hydroxyl/epoxide) groups show strong binding with polysulfides, preventing their dissolution into the electrolyte based on first-principles calculations. As a result, the G-S hybrids show a high capacity, an excellent high-rate performance, and a long life over 100 cycles. These results demonstrate the great potential of this unique hybrid structure as cathodes for high-performance lithium-sulfur batteries. PMID:23672616

  19. Airborne sulfur trace species intercomparison campaign: Sulfur dioxide, dimethylsulfide, hydrogen sulfide, carbon disulfide, and carbonyl sulfide

    NASA Technical Reports Server (NTRS)

    Gregory, Gerald L.; Hoell, James M., Jr.; Davis, Douglas D.

    1991-01-01

    Results from an airborne intercomparison of techniques to measure tropospheric levels of sulfur trace gases are presented. The intercomparison was part of the NASA Global Tropospheric Experiment (GTE) and was conducted during the summer of 1989. The intercomparisons were conducted on the Wallops Electra aircraft during flights from Wallops Island, Virginia, and Natal, Brazil. Sulfur measurements intercompared included sulfur dioxide (SO2), dimethylsulfide (DMS), hydrogen sulfide (H2S), carbon disulfide (CS2), and carbonyl sulfide (OCS). Measurement techniques ranged from filter collection systems with post-flight analyses to mass spectrometer and gas chromatograph systems employing various methods for measuring and identifying the sulfur gases during flight. Sampling schedules for the techniques ranged from integrated collections over periods as long as 50 minutes to one- to three-minute samples every ten or fifteen minutes. Several of the techniques provided measurements of more than one sulfur gas. Instruments employing different detection principles were involved in each of the sulfur intercomparisons. Also included in the intercomparison measurement scenario were a host of supporting measurements (i.e., ozone, nitrogen oxides, carbon monoxide, total sulfur, aerosols, etc.) for purposes of: (1) interpreting results (i.e., correlation of any noted instrument disagreement with the chemical composition of the measurement environment); and (2) providing supporting chemical data to meet CITE-3 science objectives of studying ozone/sulfur photochemistry, diurnal cycles, etc. The results of the intercomparison study are briefly discussed.

  20. COULOMETRIC DETERMINATION OF TOTAL SULFUR AND REDUCED INORGANIC SULFUR FRACTIONS IN ENVIRONMENTAL SAMPLES

    EPA Science Inventory

    Evaluation of the solid-phase partitioning of sulfur is frequently an important analytical component of risk assessments at hazardous waste sites because minerals containing reduced-sulfur can significantly affect the transport and fate of organic and inorganic contaminants in na...

  1. Infiltrating sulfur into a highly porous carbon sphere as cathode material for lithium–sulfur batteries

    SciTech Connect

    Zhao, Xiaohui; Kim, Dul-Sun; Ahn, Hyo-Jun; Kim, Ki-Won; Cho, Kwon-Koo; Ahn, Jou-Hyeon

    2014-10-15

    Highlights: • A highly porous carbon (HPC) with regular spherical morphology was synthesized. • Sulfur/HPC composites were prepared by melt–diffusion method. • Sulfur/HPC composites showed improved cyclablity and long-term cycle life. - Abstract: Sulfur composite material with a highly porous carbon sphere as the conducting container was prepared. The highly porous carbon sphere was easily synthesized with resorcinol–formaldehyde precursor as the carbon source. The morphology of the carbon was observed with field emission scanning electron microscope and transmission electron microscope, which showed a well-defined spherical shape. Brunauer–Emmett–Teller analysis indicated that it possesses a high specific surface area of 1563 m{sup 2} g{sup −1} and a total pore volume of 2.66 cm{sup 3} g{sup −1} with a bimodal pore size distribution, which allow high sulfur loading and easy transportation of lithium ions. Sulfur carbon composites with varied sulfur contents were prepared by melt–diffusion method and lithium sulfur cells with the sulfur composites showed improved cyclablity and long-term cycle life.

  2. Workshop on sulfur chemistry in flue gas desulfurization

    SciTech Connect

    Wallace, W.E. Jr.

    1980-05-01

    The Flue Gas Desulfurization Workshop was held at Morgantown, West Virginia, June 7-8, 1979. The presentations dealt with the chemistry of sulfur and calcium compounds in scrubbers. DOE and EPRI programs in this area are described. Ten papers have been entered individually into EDB and ERA. (LTN)

  3. Direct Observation of Sulfur Radicals as Reaction Media in lithium Sulfur Batteries

    SciTech Connect

    Wang, Qiang; Zheng, Jianming; Walter, Eric D.; Pan, Huilin; Lu, Dongping; Zuo, Pengjian; Chen, Honghao; Deng, Zhiqun; Liaw, Bor Yann; Yu, Xiqian; Yang, Xiaoning; Zhang, Jiguang; Liu, Jun; Xiao, Jie

    2014-12-09

    Lithium sulfur (Li-S) battery has been regaining tremendous interest in recent years because of its attractive attributes such as high gravimetric energy, low cost and environmental benignity. However, it is still not conclusively known how polysulfide ring/chain participates in the whole cycling and whether the discharge and charge process follow the same pathway. Herein, we demonstrate the direct observation of sulfur radicals by using in situ electron paramagnetic resonance (EPR) technique. Based on the concentration changes of sulfur radicals at different potentials, it is revealed that the chemical and electrochemical reactions in Li-S cell are driven each other to proceed through sulfur radicals, leading to two completely different reaction pathways during discharge and charge. The proposed radical mechanism may provide new insights to investigate the interactions between sulfur species and the electrolyte, inspiring novel strategies to develop Li-S battery technology.

  4. Direct Observation of Sulfur Radicals as Reaction Media in Lithium Sulfur Batteries

    DOE PAGESBeta

    Wang, Qiang; Zheng, Jianming; Walter, Eric; Pan, Huilin; Lv, Dongping; Zuo, Pengjian; Chen, Honghao; Deng, Z. D.; Liaw, Bor Y.; Yu, Xiqian; et al

    2015-01-09

    Lithium sulfur (Li-S) battery has been regaining tremendous interest in recent years because of its attractive attributes such as high gravimetric energy, low cost and environmental benignity. However, it is still not conclusively known how polysulfide ring/chain participates in the whole cycling and whether the discharge and charge processes follow the same pathway. Herein, we demonstrate the direct observation of sulfur radicals by using in situ electron paramagnetic resonance (EPR) technique. Based on the concentration changes of sulfur radicals at different potentials and the electrochemical characteristics of the cell, it is revealed that the chemical and electrochemical reactions in Li-Smore » cell are driving each other to proceed through sulfur radicals, leading to two completely different reaction pathways during discharge and charge. The proposed radical mechanism may provide new perspectives to investigate the interactions between sulfur species and the electrolyte, inspiring novel strategies to develop Li-S battery technology.« less

  5. Direct Observation of Sulfur Radicals as Reaction Media in Lithium Sulfur Batteries

    SciTech Connect

    Wang, Qiang; Zheng, Jianming; Walter, Eric; Pan, Huilin; Lv, Dongping; Zuo, Pengjian; Chen, Honghao; Deng, Z. D.; Liaw, Bor Y.; Yu, Xiqian; Yang, Xiao-Qing; Zhang, Ji-Guang; Liu, Jun; Xiao, Jie

    2015-01-09

    Lithium sulfur (Li-S) battery has been regaining tremendous interest in recent years because of its attractive attributes such as high gravimetric energy, low cost and environmental benignity. However, it is still not conclusively known how polysulfide ring/chain participates in the whole cycling and whether the discharge and charge processes follow the same pathway. Herein, we demonstrate the direct observation of sulfur radicals by using in situ electron paramagnetic resonance (EPR) technique. Based on the concentration changes of sulfur radicals at different potentials and the electrochemical characteristics of the cell, it is revealed that the chemical and electrochemical reactions in Li-S cell are driving each other to proceed through sulfur radicals, leading to two completely different reaction pathways during discharge and charge. The proposed radical mechanism may provide new perspectives to investigate the interactions between sulfur species and the electrolyte, inspiring novel strategies to develop Li-S battery technology.

  6. Electrostatic self-assembly of graphene oxide wrapped sulfur particles for lithium–sulfur batteries

    SciTech Connect

    Wu, Haiwei; Huang, Ying Zong, Meng; Ding, Xiao; Ding, Juan; Sun, Xu

    2015-04-15

    Highlights: • Researched graphene oxide wrapped sulfur particles for lithium–sulfur batteries. • New approach for core–shell GO/S composites by electrostatic self-assembly method. • Both core–shell structure and the GO support help to retard the diffusion of polysulfides during the electrochemical cycling process of GO/S cathode. - Abstract: A novel graphene oxide (GO)/sulfur (S) composite is developed by electrostatic self-assembly method. Remarkably, the core–shell structure of the composite and the GO support helps to retard the diffusion of polysulfides during the electrochemical cycling process. The GO/sulfur cathode presents enhanced cycling ability. Specific discharge capacities up to 494.7 mAh g{sup −1} over 200 cycles at 0.1 C is achieved with enhanced columbic efficiency around 95%, representing a good cathode material for lithium–sulfur batteries.

  7. 40 CFR Appendix T to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) T Appendix T to Part 50 Protection of... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) 1. General (a) This appendix explains... ambient air quality standards for Oxides of Sulfur as measured by Sulfur Dioxide (“SO2 NAAQS”)...

  8. 40 CFR Appendix T to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) T Appendix T to Part 50 Protection of... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) 1. General (a) This appendix explains... ambient air quality standards for Oxides of Sulfur as measured by Sulfur Dioxide (“SO2 NAAQS”)...

  9. 40 CFR Appendix T to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) T Appendix T to Part 50 Protection of... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) 1. General (a) This appendix explains... ambient air quality standards for Oxides of Sulfur as measured by Sulfur Dioxide (“SO2 NAAQS”)...

  10. 40 CFR Appendix T to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) T Appendix T to Part 50 Protection of... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) 1. General (a) This appendix explains... ambient air quality standards for Oxides of Sulfur as measured by Sulfur Dioxide (“SO2 NAAQS”)...

  11. Extraction, separation, and analysis of high sulfur coal

    SciTech Connect

    Olesik, S.V.; Pekay, L.A.; Larkins, W. Jr.

    1992-05-31

    The work described in this report studies the removal of sulfur by oxidative interaction of various cupric salts with coal and also considers the possibility of removing organic sulfur by the selective interaction of supercritical ethanol with the organic coal matrix. Either one of these methods could potentially be used to pretreat coals before burning. The primary purpose of these studies is to ascertain the nature of the chemical reactions occurring, the chemical composition of the resultant products, and information on possible reaction mechanisms. This information should allow prediction of reasonable reaction conditions for the removal of organosulfur compound from coal.

  12. Extraction, separation, and analysis of high sulfur coal. Final report

    SciTech Connect

    Olesik, S.V.; Pekay, L.A.; Larkins, W. Jr.

    1992-05-31

    The work described in this report studies the removal of sulfur by oxidative interaction of various cupric salts with coal and also considers the possibility of removing organic sulfur by the selective interaction of supercritical ethanol with the organic coal matrix. Either one of these methods could potentially be used to pretreat coals before burning. The primary purpose of these studies is to ascertain the nature of the chemical reactions occurring, the chemical composition of the resultant products, and information on possible reaction mechanisms. This information should allow prediction of reasonable reaction conditions for the removal of organosulfur compound from coal.

  13. Experiments on δ34S mixing between organic and inorganic sulfur species during thermal maturation

    USGS Publications Warehouse

    Amrani, Alon; Said-Ahamed, Ward; Lewan, Michael D.; Aizenshtat, Zeev

    2006-01-01

    Reduced sulfur species were studied to constrain isotopic exchange-mixing with synthetic polysulfide cross-linked macromolecules (PCLM), model sulfur containing molecules and natural sulfur-rich kerogen, asphalt and oil of the Dead Sea area. PCLM represents protokerogens that are rich in sulfur and thermally unstable. Mixing rates of PCLM with HS-(aq) (added as (NH4)2S(aq)) at low to moderate temperatures (50–200 °C) are rapid. Elemental sulfur and H2S(gas) fully mix isotopes with PCLM during pyrolysis conditions at 200 °C. During these reactions significant structural changes of the PCLM occur to form polysulfide dimers, thiolanes and thiophenes. As pyrolysis temperatures or reaction times increase, the PCLM thermal products are transformed to more aromatic sulfur compounds. Isotopic mixing rates increase with increasing pyrolysis temperature and time. Polysulfide bonds (S–S) in the PCLM are responsible for most of these structural and isotopic changes because of their low stability. Conversely, sulfur isotope mixing does not occur between dibenzothiophene (aromatic S) or hexadecanthiol (C–SH) and HS-(aq) at 200 °C after 48 h. This shows that rates of sulfur isotope mixing are strongly dependent on the functionality of the sulfur in the organic matter. The order of isotopic mixing rates for organic matter is kerogen > asphalt > oil, which is inverse to their sulfur thermal stability. Asphalt and oil with more refractory sulfur show significantly lower isotopes mixing rates than the kerogen with more labile sulfur. Based on the findings of the present study we suggest that sulfur isotopes mixing can occur from early diagenesis into catagenesis and result in isotopic homogenization of the inorganic and organic reduced sulfur pools.

  14. Sulfuration of the C(sp(2))-H bond of enaminones: a protocol for the synthesis of thioether using elemental sulfur as a sulfurating reagent.

    PubMed

    Yang, Li-Fang; Liu, Cheng-Guo; Xu, Xiao-Ping; Ji, Shun-Jun

    2016-03-01

    Sulfuration reaction of the C(sp(2))-H bond of enaminones with elemental sulfur in the presence of CuBr/K3PO4 was carried out. It provided an efficient method for the synthesis of thioethers in moderate to good yields. The protocol was also applicable to synthesize selenides when selenium powder was used instead of sulfur powder. PMID:26889717

  15. Effect of sulfur content in a sulfur-activated carbon composite on the electrochemical properties of a lithium/sulfur battery

    SciTech Connect

    Park, Jin-Woo; Kim, Changhyeon; Ryu, Ho-Suk; Cho, Gyu-Bong; Cho, Kwon-Koo; Kim, Ki-Won; Ahn, Jou-Hyeon; Wang, Guoxiu; Ahn, Jae-Pyeung; Ahn, Hyo-Jun

    2015-09-15

    Highlights: • The content of sulfur in activated carbon was controlled by solution process. • The sulfur electrode with low sulfur content shows the best performance. • The Li/S battery has capacity of 1360 mAh/g at 1 C and 702 mAh/g at 10 C. - Abstract: The content of sulfur in sulfur/activated carbon composite is controlled from 32.37 wt.% to 55.33 wt.% by a one-step solution-based process. When the sulfur content is limited to 41.21 wt.%, it can be loaded into the pores of an activated carbon matrix in a highly dispersed state. On the contrary, when the sulfur content is 55.33 wt.%, crystalline sulfur can be detected on the surface of the activated carbon matrix. The best electrochemical performance can be obtained for a sulfur electrode with the lowest sulfur content. The sulfur/activated carbon composite with 32.37 wt.% sulfur afforded the highest first discharge capacity of 1360 mAh g{sup −1} at 1 C rate and a large reversible capacity of 702 mAh g{sup −1} at 10 C (16.75 A/g)

  16. Sulfur vesicles from Thermococcales: A possible role in sulfur detoxifying mechanisms

    PubMed Central

    Gorlas, A.; Marguet, E.; Gill, S.; Geslin, C.; Guigner, J.-M.; Guyot, F.; Forterre, P.

    2015-01-01

    The euryarchaeon Thermococcus prieurii inhabits deep-sea hydrothermal vents, one of the most extreme environments on Earth, which is reduced and enriched with heavy metals. Transmission electron microscopy and cryo-electron microscopy imaging of T. prieurii revealed the production of a plethora of diverse membrane vesicles (MVs) (from 50 nm to 400 nm), as is the case for other Thermococcales. T. prieurii also produces particularly long nanopods/nanotubes, some of them containing more than 35 vesicles encased in a S-layer coat. Notably, cryo-electron microscopy of T. prieurii cells revealed the presence of numerous intracellular dark vesicles that bud from the host cells via interaction with the cytoplasmic membrane. These dark vesicles are exclusively found in conjunction with T. prieurii cells and never observed in the purified membrane vesicles preparations. Energy-Dispersive-X-Ray analyses revealed that these dark vesicles are filled with sulfur. Furthermore, the presence of these sulfur vesicles (SVs) is exclusively observed when elemental sulfur was added into the growth medium. In this report, we suggest that these atypical vesicles sequester the excess sulfur not used for growth, thus preventing the accumulation of toxic levels of sulfur in the host's cytoplasm. These SVs transport elemental sulfur out of the cell where they are rapidly degraded. Intriguingly, closely related archaeal species, Thermococcus nautili and Thermococcus kodakaraensis, show some differences about the production of sulfur vesicles. Whereas T. kodakaraensis produces less sulfur vesicles than T. prieurii, T. nautili does not produce such sulfur vesicles, suggesting that Thermococcales species exhibit significant differences in their sulfur metabolic pathways. PMID:26234734

  17. Clues to early diagenetic sulfurization processes from mild chemical cleavage of labile sulfur-rich geomacromolecules

    NASA Astrophysics Data System (ADS)

    Adam, P.; Schneckenburger, P.; Schaeffer, P.; Albrecht, P.

    2000-10-01

    Macromolecular fractions, isolated from the solvent extract of sulfur-rich Recent (Siders Pond, USA; Lake Cadagno, Switzerland; Walvis Bay, Namibia) and immature sediments (Gibellina, Messinian of Sicily; Vena del Gesso, Messinian of Italy), were investigated by chemical degradation using sodium ethanethiolate/methyliodide. This mild reagent which cleaves polysulfide bonds to yield methylsulfides has the advantage over other methods of leaving intact other functionalities (like double bonds) and preserving sulfur atoms at their incorporation site. The method is, therefore, well-suited to the molecular level investigation of sulfur-rich macromolecules from Recent sediments containing highly functionalized polysulfide-bound subunits. In Recent anoxic sulfur-rich sediments, the release of various methylthioethers clearly demonstrates that intermolecular sulfurization of organic matter does occur at the earliest stages of diagenesis. Steroids and phytane derivatives are the major sulfurized lipids, a feature also observed in more mature sulfur-rich sediments. Several phytene derivatives, such as cis and trans 1-methylthiophyt-2-enes, as well as methylthiosteroids, including 5α- and 5β-3-(methylthio)-cholest-2-enes, were identified by comparison with synthesized standards. Steroid methylthioenolethers are released from polysulfide-bound steroid enethiols present in the macromolecular fractions. The latter, which correspond to thioketones, can be considered as intermediates in the reductive sulfurization pathway leading from steroid ketones to polysulfide-bound saturated steroid skeletons and are characterized for the first time in the present study. Thus, it could be shown that the major part of the polysulfide-bound lipids occurring in Recent sediments is apparently the result of sulfurization processes affecting carbonyls (aldehydes and ketones). The unsaturated methylthioethers obtained from Recent sediments were not present in more mature evaporitic samples, which suggests that polysulfide-bound unsaturated thiols are intermediates formed during the first sulfurization steps occurring soon after deposition and that they are rapidly transformed by various processes taking place during early diagenesis, notably to yield their saturated counterparts.

  18. Sulfur vesicles from Thermococcales: A possible role in sulfur detoxifying mechanisms.

    PubMed

    Gorlas, A; Marguet, E; Gill, S; Geslin, C; Guigner, J-M; Guyot, F; Forterre, P

    2015-11-01

    The euryarchaeon Thermococcus prieurii inhabits deep-sea hydrothermal vents, one of the most extreme environments on Earth, which is reduced and enriched with heavy metals. Transmission electron microscopy and cryo-electron microscopy imaging of T. prieurii revealed the production of a plethora of diverse membrane vesicles (MVs) (from 50 nm to 400 nm), as is the case for other Thermococcales. T. prieurii also produces particularly long nanopods/nanotubes, some of them containing more than 35 vesicles encased in a S-layer coat. Notably, cryo-electron microscopy of T. prieurii cells revealed the presence of numerous intracellular dark vesicles that bud from the host cells via interaction with the cytoplasmic membrane. These dark vesicles are exclusively found in conjunction with T. prieurii cells and never observed in the purified membrane vesicles preparations. Energy-Dispersive-X-Ray analyses revealed that these dark vesicles are filled with sulfur. Furthermore, the presence of these sulfur vesicles (SVs) is exclusively observed when elemental sulfur was added into the growth medium. In this report, we suggest that these atypical vesicles sequester the excess sulfur not used for growth, thus preventing the accumulation of toxic levels of sulfur in the host's cytoplasm. These SVs transport elemental sulfur out of the cell where they are rapidly degraded. Intriguingly, closely related archaeal species, Thermococcus nautili and Thermococcus kodakaraensis, show some differences about the production of sulfur vesicles. Whereas T. kodakaraensis produces less sulfur vesicles than T. prieurii, T. nautili does not produce such sulfur vesicles, suggesting that Thermococcales species exhibit significant differences in their sulfur metabolic pathways. PMID:26234734

  19. Ametryne and Prometryne as Sulfur Sources for Bacteria

    PubMed Central

    Cook, Alasdair M.; Hütter, Ralf

    1982-01-01

    Bacteria were isolated that could utilize quantitatively the s-triazine herbicide prometryne [N,N′ -bis(1-methylethyl)-6-(methylthio)-1,3,5-triazine-2,4-diamine] or ametryne [N-ethyl-N′-(1-methylethyl)-6-(methylthio)-1,3,5-triazine- 2,4-diamine], or both, as a sole source of sulfur for growth. The success of enrichments depended on previous exposure of the soil inoculum to s-triazine herbicides. Deaminoethylametryne [4-(1-methylethyl)amino-6-(methylthio)-1,3,5-triazine-2-(1H)-one], methylsulfonic acid, and sodium sulfate could also be used as sulfur sources. Utilization of a compound was quantified as the growth yield per mole of sulfur supplied. Yields were about 6 kg of protein per mol of sulfur. The product of the desulfuration of an s-triazine was identified as the corresponding hydroxy-derivative. This is the first substantiated report of the utilization of these s-triazines as sulfur sources by bacteria. PMID:16345988

  20. A primer on sulfur for the planetary geologist

    NASA Technical Reports Server (NTRS)

    Theilig, E.

    1982-01-01

    Sulfur has been proposed as the dominant composition for the volcanic material on Io. Sulfur is a complex element which forms many intramolecular and intermolecular allotropes exhibiting a variety of physical properties. Cyclo-S8 sulfur is the most abundant and stable molecular form. The important molecular species within liquid sulfur change in concentration with temperature. Concentrations of the allotropes control the physical properties of the melt. Discontinuities in density, viscosity, and thermal properties reflect the polymerization process within liquid sulfur. Variations in the melting point are related to autodissociation of the liquid. Many solids forms of sulfur have been identified but only orthorhombic alpha and monoclinic beta sulfur, both composed of cyclo-S8 sulfur, are stable under terrestrial conditions. Physical properties of solid sulfur are dependent on the allotrope and, in some cases, the thermal history. Three natural terrestrial sulfur flows are described: (1) Siretoko-Iosan, Japan; (2) Volcan Azufre, Galapagos Islands; and (3) Mauna Loa, Hawaii. All of the flows are associated with fumarolic areas and are considered to have formed by the melting and mobilization of sulfur deposits. Surface textures of the flows indicate a behavior of molten sulfur similar to that of silicate lava. Channels, rivulets, and lobate edges were described for the flows. The solidification of man-made sulfur flows formed as part of the Frasch mining process by which sulfur is removed from the subsurface in a liquid state is described.