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Sample records for control sulfur

  1. ADVANCED SULFUR CONTROL CONCEPTS

    Energy Technology Data Exchange (ETDEWEB)

    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).

  2. Sulfur Dioxide Emission Control, Blockade and Drainage

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This paper presents the present status of sulfur dioxide emission from thermal plants in China, tells the main problems existing in its emission control and finally gives out suggestions to the problems, that is, to constitute complete standards and regulations and enhancesupervision accordingly.

  3. ADVANCED SULFUR CONTROL CONCEPTS FOR HOT GAS DESULFURIZATION TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    1999-04-01

    The objective of this project is to develop a hot-gas desulfurization process scheme for control of H{sub 2}S in HTHP coal gas that can be more simply and economically integrated with known regenerable sorbents in DOE/METC-sponsored work than current leading hot-gas desulfurization technologies. In addition to being more economical, the process scheme to be developed must yield an elemental sulfur byproduct.

  4. ADVANCED SULFUR CONTROL CONCEPTS FOR HOT GAS DESULFURIZATION TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-12-31

    The objective of this project is to develop a hot-gas desulfurization process scheme for control of H{sub 2}S in HTHP coal gas that can be more simply and economically integrated with known regenerable sorbents in DOE/METC-sponsored work than current leading hot-gas desulfurization technologies. In addition to being more economical, the process scheme to be developed must yield an elemental sulfur byproduct.

  5. FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Gary M. Blythe

    2001-11-06

    This document summarizes progress on Cooperative Agreement DE-FC26-99FT40718, Furnace Injection of Alkaline Sorbents for Sulfuric Acid Control, during the time period April 1, 2001 through September 30, 2001. The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The coincident removal of hydrochloric acid and hydrofluoric acid is also being determined, as is the removal of arsenic, a known poison for NO{sub x} selective catalytic reduction (SCR) catalysts. EPRI, the Tennessee Valley Authority (TVA), FirstEnergy Corporation, and the Dravo Lime Company are project co-funders. URS Corporation is the prime contractor. During the current period, American Electric Power (AEP) joined the project as an additional co-funder and as a provider of a host site for testing. This is the fourth reporting period for the subject Cooperative Agreement. During this period, two long-term sorbent injection tests were conducted, one on Unit 3 at FirstEnergy's Bruce Mansfield Plant (BMP) and one on Unit 1 at AEP's Gavin Station. These tests determined the effectiveness of injecting alkaline slurries into the upper furnace of the boiler as a means of controlling sulfuric acid emissions from these units. The alkaline slurries tested included commercially available magnesium hydroxide slurry (Gavin Station), and a byproduct magnesium hydroxide slurry (both Gavin Station and BMP). The tests showed that injecting either the commercial or the byproduct magnesium hydroxide slurry could achieve up to 70 to 75% sulfuric acid removal. At BMP, the overall removal was limited by the need to maintain acceptable electrostatic precipitator (ESP) particulate control performance. At Gavin Station, the overall sulfuric acid removal was limited because the furnace injected sorbent was less effective at removing SO{sub 3} formed across the SCR system installed on the unit for NO

  6. FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Gary M. Blythe

    2003-10-01

    This document summarizes progress on Cooperative Agreement DE-FC26-99FT40718, Furnace Injection of Alkaline Sorbents for Sulfuric Acid Control, during the time period April 1, 2003 through September, 2003. The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The coincident removal of hydrochloric acid and hydrofluoric acid is also being determined, as is the removal of arsenic, a known poison for NO{sub x} selective catalytic reduction (SCR) catalysts. EPRI, the Tennessee Valley Authority (TVA), FirstEnergy Corporation, American Electric Power (AEP) and the Dravo Lime Company are project co-funders. URS Group is the prime contractor. This is the eighth reporting period for the subject Cooperative Agreement. During previous reporting periods, two long-term sorbent injection tests were conducted, one on Unit 3 at FirstEnergy's Bruce Mansfield Plant (BMP) and one on Unit 1 at AEP's Gavin Plant. Those tests determined the effectiveness of injecting alkaline slurries into the upper furnace of the boiler as a means of controlling sulfuric acid emissions from these units. The alkaline slurries tested included commercially available magnesium hydroxide slurry (Gavin Plant), and a byproduct magnesium hydroxide slurry (both Gavin Plant and BMP). The tests showed that injecting either the commercial or the byproduct magnesium hydroxide slurry could achieve up to 70-75% overall sulfuric acid removal. At BMP, the overall removal was limited by the need to maintain acceptable electrostatic precipitator (ESP) particulate control performance. At Gavin Plant, the overall sulfuric acid removal was limited because the furnace injected sorbent was less effective at removing SO{sub 3} formed across the SCR system installed on the unit for NO{sub x} control than at removing SO{sub 3} formed in the furnace. The SO{sub 3} removal results were presented in

  7. Induced rhinovirus infection under controlled exposure to sulfur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, I. (Aarhus, Univ., Denmark); Jensen, P.L.; Reed, S.E.; Craig, J.W.; Proctor, D.F.; Adams, G.K.

    1977-01-01

    The interaction between short-term sulfur dioxide (SO/sub 2/) exposure and experimentally induced rhinovirus infection was studied in thirty-two volunteers divided into two groups balanced with respect to age, antibody levels, and nasal mucous flow rates. One group was exposed to SO/sub 2/ at the threshold limit value (TLV) of 5 ppM during 4 hours; the other group served as controls exposed to pollution-free air under the same conditions. The SO/sub 2/ exposure caused a 50% decrease in nasal mucous flow rate in the anterior parts of the nose, but there was no difference in the number of colds which developed in the two groups. The group exposed to SO/sub 2/ had fewer symptoms and a possibly shorter incubation period (P = .06), and virus shedding was at a lower level but more persistent than in the control group. No differences were found in antibody response. The rhinovirus infection in the control group caused a gradual decrease in nasal mucus flow rate starting 2 days after the virus instillation, and after 5 days the rate was less than half its initial value. For future experiments on the interaction between airborne pollutants and rhinovirus infections, a virus challenge by aerosol inhalation is recommended. Our study supports an earlier observation that growth of influenza virus in the nasal cavity of mice was inhibited by exposure to SO/sub 2/ concentrations of 6 or 20 ppM.

  8. Controllable embedding of sulfur in high surface area nitrogen doped three dimensional reduced graphene oxide by solution drop impregnation method for high performance lithium-sulfur batteries

    Science.gov (United States)

    Zegeye, Tilahun Awoke; Tsai, Meng-Che; Cheng, Ju-Hsiang; Lin, Ming-Hsien; Chen, Hung-Ming; Rick, John; Su, Wei-Nien; Kuo, Chung-Feng Jeffrey; Hwang, Bing-Joe

    2017-06-01

    High capacity lithium-sulfur batteries with stable cycle performance and sulfur loadings greater than 70 wt% are regarded as promising candidates for energy storage devices. However, it has been challenged to achieving practical application of sulfur cathode because of low loading of active sulfur and poor cycle performance. Herein, we design novel nanocomposite cathode materials consist of sulfur (80 wt%) embedded within nitrogen doped three-dimensional reduced graphene oxide (N-3D-rGO) by controllable sulfur-impregnation method. Nitrogen doping helps increase the surface area by ten times from pristine graphene, and pore volume by seven times. These structural features allow the cathode to hold more sulfur. It also adsorbs polysulfides and prevents their detachment from the host materials; thereby achieving stable cycle performance. The solution drop sulfur-impregnation method provides uniform distribution of nano-sulfur in controlled manner. The material delivers a high initial discharge capacity of 1042 mAhg-1 and 916 mAhg-1 with excellent capacity retention of 94.8% and 81.9% at 0.2 C and 0.5 C respectively after 100 cycles. Thus, the combination of solution drop and nitrogen doping opens a new chapter for resolving capacity fading as well as long cycling problems and creates a new strategy to increase sulfur loading in controlled mechanism.

  9. Smart battery controller for lithium sulfur dioxide batteries

    Science.gov (United States)

    Atwater, Terrill; Bard, Arnold; Testa, Bruce; Shader, William

    1992-08-01

    Each year, the U.S. Army purchases millions of lithium sulfur dioxide batteries for use in portable electronics equipment. Because of their superior rate capability and service life over a wide variety of conditions, lithium batteries are the power source of choice for military equipment. There is no convenient method of determining the available energy remaining in partially used lithium batteries; hence, users do not take full advantage of all the available battery energy. Currently, users replace batteries before each mission, which leads to premature disposal, and results in the waste of millions of dollars in battery energy every year. Another problem of the lithium battery is that it is necessary to ensure complete discharge of the cells when the useful life of the battery has been expended, or when a hazardous condition exists; a hazardous condition may result in one or more of the cells venting. The Electronics Technology and Devices Laboratory has developed a working prototype of a smart battery controller (SBC) that addresses these problems.

  10. Diesel Emission Control -- Sulfur Effects (DECSE) Program; Phase I Interim Date Report No. 3: Diesel Fuel Sulfur Effects on Particulate Matter Emissions

    Energy Technology Data Exchange (ETDEWEB)

    DOE; ORNL; NREL; EMA; MECA

    1999-11-15

    The Diesel Emission Control-Sulfur Effects (DECSE) is a joint government/industry program to determine the impact of diesel fuel sulfur levels on emission control systems whose use could lower emissions of nitrogen oxides (NO{sub x}) and particulate matter (PM) from on-highway trucks in the 2002--2004 model years. Phase 1 of the program was developed with the following objectives in mind: (1) evaluate the effects of varying the level of sulfur content in the fuel on the emission reduction performance of four emission control technologies; and (2) measure and compare the effects of up to 250 hours of aging on selected devices for multiple levels of fuel sulfur content. This interim report covers the effects of diesel fuel sulfur level on particulate matter emissions for four technologies.

  11. ADVANCED SULFUR CONTROL CONCEPTS FOR HOT-GAS DESULFURIZATION TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    A. LOPEZ ORTIZ; D.P. HARRISON; F.R. GROVES; J.D. WHITE; S. ZHANG; W.-N. HUANG; Y. ZENG

    1998-10-31

    This research project examined the feasibility of a second generation high-temperature coal gas desulfurization process in which elemental sulfur is produced directly during the sorbent regeneration phase. Two concepts were evaluated experimentally. In the first, FeS was regenerated in a H2O-O2 mixture. Large fractions of the sulfur were liberated in elemental form when the H2O-O2 ratio was large. However, the mole percent of elemental sulfur in the product was always quite small (<<1%) and a process based on this concept was judged to be impractical because of the low temperature and high energy requirements associated with condensing the sulfur. The second concept involved desulfurization using CeO2 and regeneration of the sulfided sorbent, Ce2O2S, using SO2 to produce elemental sulfur directly. No significant side reactions were observed and the reaction was found to be quite rapid over the temperature range of 500°C to 700°C. Elemental sulfur concentrations (as S2) as large as 20 mol% were produced. Limitations associated with the cerium sorbent process are concentrated in the desulfurization phase. High temperature and highly reducing coal gas such as produced in the Shell gasification process are required if high sulfur removal efficiencies are to be achieved. For example, the equilibrium H2S concentration at 800°C from a Shell gas in contact with CeO2 is about 300 ppmv, well above the allowable IGCC specification. In this case, a two-stage desulfurization process using CeO2 for bulk H2S removal following by a zinc sorbent polishing step would be required. Under appropriate conditions, however, CeO2 can be reduced to non-stoichiometric CeOn (n<2) which has significantly greater affinity for H2S. Pre-breakthrough H2S concentrations in the range of 1 ppmv to 5 ppmv were measured in sulfidation tests using CeOn at 700°C in highly reducing gases, as measured by equilibrium O2 concentration, comparable to the Shell gas. Good sorbent durability was indicated in

  12. Modified dry limestone process for control of sulfur dioxide emissions

    Science.gov (United States)

    Shale, Correll C.; Cross, William G.

    1976-08-24

    A method and apparatus for removing sulfur oxides from flue gas comprise cooling and conditioning the hot flue gas to increase the degree of water vapor saturation prior to passage through a bed of substantially dry carbonate chips or lumps, e.g., crushed limestone. The reaction products form as a thick layer of sulfites and sulfates on the surface of the chips which is easily removed by agitation to restore the reactive surface of the chips.

  13. Sulfur-infiltrated porous carbon microspheres with controllable multi-modal pore size distribution for high energy lithium-sulfur batteries.

    Science.gov (United States)

    Zhao, Cunyu; Liu, Lianjun; Zhao, Huilei; Krall, Andy; Wen, Zhenhai; Chen, Junhong; Hurley, Patrick; Jiang, Junwei; Li, Ying

    2014-01-21

    Sulfur has received increasing attention as a cathode material for lithium-sulfur (Li-S) batteries due to its high theoretical specific capacity. However, the commercialization of Li-S batteries is limited by the challenges of poor electrical conductivity of sulfur, dissolution of the polysulfide intermediates into the electrolyte, and volume expansion of sulfur during cycling. Herein, we report the fabrication of novel-structured porous carbon microspheres with a controllable multi-modal pore size distribution, i.e., a combination of interconnected micropores, mesopores and macropores. Cathodes made of sulfur infiltrated in such a hierarchical carbon framework provide several advantages: (1) a continuous and high surface area carbon network for enhanced electrical conductivity and high sulfur loading; (2) macropores and large mesopores bridged by small mesopores to provide good electrolyte accessibility and fast Li ion transport and to accommodate volume expansion of sulfur; and (3) small mesopores and micropores to improve carbon/sulfur interaction and to help trap polysulfides. An initial discharge capacity at 1278 mA h g(-1) and capacity retention at 70.7% (904 mA h g(-1)) after 100 cycles at a high rate (1 C) were achieved. The material fabrication process is relatively simple and easily scalable.

  14. ULTRA-LOW SULFUR REDUCTION EMISSION CONTROL DEVICE/DEVELOPMENT OF AN ON-BOARD FUEL SULFUR TRAP

    Energy Technology Data Exchange (ETDEWEB)

    Ron Rohrbach; Gary Zulauf; Tim Gavin

    2003-04-01

    Honeywell is actively working on a 3-year program to develop and demonstrate proof-of-concept for an ''on-vehicle'' desulfurization fuel filter for heavy-duty diesel engines. Integration of the filter into the vehicle fuel system will reduce the adverse effects sulfur has on post combustion emission control devices such as NO{sub x} adsorbers. The NO{sub x} adsorber may be required to meet the proposed new EPA Tier II and ''2007-Rule'' emission standards. The proposed filter concept is based on Honeywell's reactive filtration technology and experience in liquids handling and conditioning. A regeneration and recycling plan for the spent filters will also be examined. We have chosen to develop and demonstrate this technology based on criteria set forth for a heavy duty CIDI engine system because it represents a more challenging set of conditions of service intervals and overall fuel usage over light duty systems. It is anticipated that the technology developed for heavy-duty applications will be applicable to light-duty as well. Further, technology developed under this proposal would also have application for the use of liquid based fuels for fuel cell power generation. The program consists of four phases. Phase I will focus on developing a concept design and analysis and resolution of technical barriers concerning removal of sulfur-containing species in low sulfur fuels. In Phase II we will concentrate on prototype filter design and preparation followed by qualification testing of this component in a fuel line application. Phase III will study life cycle and regeneration options for the spent filter. Phase IV will focus on efficacy and life testing and component integration. The project team will include a number of partners, with Honeywell International as the prime contractor. The partners include an emission control technology developer (Honeywell International), a fuel technology developer (Marathon Ashland Petroleum

  15. Ultra-low Sulfur Reduction Emission Control Device/Development of an On-board Fuel Sulfur Trap

    Energy Technology Data Exchange (ETDEWEB)

    Rohrbach, Ron; Barron, Ann

    2008-07-31

    Honeywell has completed working on a multiyear program to develop and demonstrate proof-of-concept for an 'on-vehicle' desulfurization fuel filter for both light duty and heavy-duty diesel engines. Integration of the filter into the vehicle fuel system will reduce the adverse effects sulfur has on post combustion emission control devices such as NOx adsorbers. The NOx adsorber may be required to meet the proposed new EPA Tier II and '2007-Rule' emission standards. The proposed filter concept is based on Honeywell's reactive filtration technology and experience in liquids handling and conditioning. A regeneration and recycling plan for the spent filters was also examined. We have chosen to develop and demonstrate this technology based on criteria set forth for a heavy duty CIDI engine system because it represents a more challenging set of conditions of service intervals and overall fuel usage over light duty systems. In the second phase of the program a light duty diesel engine test was also demonstrated. Further, technology developed under this proposal would also have application for the use of liquid based fuels for fuel cell power generation. The program consisted of four phases. Phase I focused on developing a concept design and analysis and resolution of technical barriers concerning removal of sulfur-containing species in low sulfur fuels. In Phase II concentrated on prototype filter design and preparation followed by qualification testing of this component in a fuel line application. Phase III studied life cycle and regeneration options for the spent filter. Phase IV focused on efficacy and benefits in the desulfation steps of a NOx adsorber on both a heavy and light duty engine. The project team included a number of partners, with Honeywell International as the prime contractor. The partners include an emission control technology developer (Honeywell International), a fuel technology developer (Marathon Ashland Petroleum), a

  16. 75 FR 7426 - Tier 2 Light-Duty Vehicle and Light-Duty Truck Emission Standards and Gasoline Sulfur Control...

    Science.gov (United States)

    2010-02-19

    ... Truck Emission Standards and Gasoline Sulfur Control Requirements (Section 610 Review) AGENCY... Emissions Standards and Gasoline Sulfur Control Requirements rule (Tier 2 Program) on February 10, 2000 (65... Review. SUMMARY: On February 10, 2000 (65 FR 6698), EPA published emission standards for light-duty...

  17. 40 CFR 80.500 - What are the implementation dates for the motor vehicle diesel fuel sulfur control program?

    Science.gov (United States)

    2010-07-01

    ... the motor vehicle diesel fuel sulfur control program? 80.500 Section 80.500 Protection of Environment... Motor Vehicle Diesel Fuel; Nonroad, Locomotive, and Marine Diesel Fuel; and ECA Marine Fuel General Information § 80.500 What are the implementation dates for the motor vehicle diesel fuel sulfur control...

  18. Mesoporous carbon spheres with controlled porosity for high-performance lithium-sulfur batteries

    Science.gov (United States)

    Wang, Dexian; Fu, Aiping; Li, Hongliang; Wang, Yiqian; Guo, Peizhi; Liu, Jingquan; Zhao, Xiu Song

    2015-07-01

    Mesoporous carbon (MC) spheres with hierarchical pores, controlled pore volume and high specific surface areas have been prepared by a mass-producible spray drying assisted template method using sodium alginate as carbon precursor and commercial colloidal silica particles as hard template. The resulting MC spheres, possessing hierarchical pores in the range of 3-30 nm, are employed as conductive matrices for the preparation of cathode materials for lithium-sulfur batteries. A high pressure induced one-step impregnation of elemental sulfur into the pore of the MC spheres has been exploited. The electrochemical performances of sulfur-impregnated MC spheres (S-MC) derived from MC spheres with different pore volume and specific surface area but with the same sulfur loading ratio of 60 wt% (S-MC-X-60) have been investigated in details. The S-MC-4-60 composite cathode material displayed a high initial discharge capacity of 1388 mAhg-1 and a good cycling stability of 857 mAhg-1 after 100 cycles at 0.2C, and shows also excellent rate capability of 864 mAhg-1 at 2C. More importantly, the sulfur loading content in MC-4 spheres can reach as high as 80%, and it still can deliver a capacity of 569 mAhg-1 after 100 cycles at 0.2C.

  19. Pressurized fluidized-bed hydroretorting of Eastern oil shales -- Sulfur control

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, M.J.; Abbasian, J.; Akin, C.; Lau, F.S.; Maka, A.; Mensinger, M.C.; Punwani, D.V.; Rue, D.M. (Institute of Gas Technology, Chicago, IL (United States)); Gidaspow, D.; Gupta, R.; Wasan, D.T. (Illinois Inst. of Tech., Chicago, IL (United States)); Pfister, R.M.: Krieger, E.J. (Ohio State Univ., Columbus, OH (United States))

    1992-05-01

    This topical report on Sulfur Control'' presents the results of work conducted by the Institute of Gas Technology (IGT), the Illinois Institute of Technology (IIT), and the Ohio State University (OSU) to develop three novel approaches for desulfurization that have shown good potential with coal and could be cost-effective for oil shales. These are (1) In-Bed Sulfur Capture using different sorbents (IGT), (2) Electrostatic Desulfurization (IIT), and (3) Microbial Desulfurization and Denitrification (OSU and IGT). The objective of the task on In-Bed Sulfur Capture was to determine the effectiveness of different sorbents (that is, limestone, calcined limestone, dolomite, and siderite) for capturing sulfur (as H{sub 2}S) in the reactor during hydroretorting. The objective of the task on Electrostatic Desulfurization was to determine the operating conditions necessary to achieve a high degree of sulfur removal and kerogen recovery in IIT's electrostatic separator. The objectives of the task on Microbial Desulfurization and Denitrification were to (1) isolate microbial cultures and evaluate their ability to desulfurize and denitrify shale, (2) conduct laboratory-scale batch and continuous tests to improve and enhance microbial removal of these components, and (3) determine the effects of processing parameters, such as shale slurry concentration, solids settling characteristics, agitation rate, and pH on the process.

  20. Study on Control Strategy of Sulfur Dioxide Concentration in the Urban Area of Shijiazhuang

    Institute of Scientific and Technical Information of China (English)

    李光军; 于立军; 范丽; 王宇新; 赵根喜

    2003-01-01

    Two Gaussian air quality dispersion models, the industrial source complex short-term model (ISCST3) with and without modification have been used to simulate the pollutant concentration distribution in urban areas based on the meteorological data and the emissions distribution of sulfur dioxide. The verified data show that the modified model is more accurate in the urban area of Shijiazhuang. Using the modified model predictions, the control strategies of sulfur dioxide in the urban area have been studied, and the result show that the second long-term (to 2010) strategy can mitigate air pollution significantly and maintain pollution levels within permissible limits.

  1. 78 FR 5303 - Approval and Promulgation of Implementation Plans; State of Missouri; Control of Sulfur Emissions...

    Science.gov (United States)

    2013-01-25

    ... economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C... 10 CSR 10- 5.570 Control of Sulfur Emissions from Stationary Boilers to the SIP. This rule reduces... is approving the request to amend the Missouri SIP by approving the State's request to add 10 CSR 10...

  2. Sulfur Dust Bag: A Novel Technique for Ectoparasite Control in Poultry Systems.

    Science.gov (United States)

    Murillo, Amy C; Mullens, Bradley A

    2016-07-18

    Animal welfare-driven legislation and consumer demand are changing how laying chickens are housed, thus creating challenges for ectoparasite control. Hens housed in suspended wire cages (battery cages) are usually treated with high-pressure pesticides. This application type is difficult in enriched-cage or cage-free production. Alternatives to pesticide sprays are needed in enriched-cage or cage-free systems. In this study, we tested the efficacy of sulfur dust deployed in "dust bags" for control against the northern fowl mite (Ornithonyssus sylviarum), which causes host stress, decreased egg production, and reduced feed conversion efficiency. Dust bags were hung from the tops of cages or were clipped to the inside front of cages. We also tested permethrin-impregnated plastic strips, marketed for ectoparasite control in caged or cage-free commercial and backyard flocks. Previous work has shown sulfur to be very active against poultry ectoparasites; however, we found that the placement of bags was important for mite control. Sulfur in hanging bags reduced mites on treatment birds by 95 or 97% (depending on trial) within one week of being deployed, and mite counts on these birds were zero after 2 wk. Clipped sulfur bags acted more slowly and did not significantly reduce mites in one trial, but reduced mite counts to zero after 4 wk in trial 2. Permethrin strips had no effect on mite populations. This may have been due to mite resistance, even though this mite population had not been exposed to pyrethroids for several years. Sulfur bags should be effective in caged or cage-free systems. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Control of sulfur partitioning between primary and secondary metabolism in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Stanislav eKopriva

    2012-07-01

    Full Text Available Sulfur is an essential nutrient for all organisms. Plants are able to take up inorganic sulfate and assimilate it into a range of bioorganic molecules either after reduction to sulfide or activation to 3’-phosphoadenosine 5’-phosphosulfate. While the regulation of the reductive part of sulfate assimilation and the synthesis of cysteine has been studied extensively in the past three decades, much less attention has been paid to the control of synthesis of sulfated compounds. Only recently the genes and enzymes activating sulfate and transferring it onto suitable acceptors have been investigated in detail with emphasis on understanding the diversity of the sulfotransferase gene family and the control of partitioning of sulfur between the two branches of sulfate assimilation. Here the recent progress in our understanding of these processes will be summarised.

  4. Controlling crystalline structure of ZnS nanocrystals only by tuning sulfur precursor addition rate.

    Science.gov (United States)

    Bi, Chong; Pan, Liqing; Xu, Mei; Xiao, John Q

    2010-12-01

    Unlike previous studies that emphasize the important role of thermodynamics or surface energy on the structure stabilization of ZnS nanocrystals, we successfully controlled the crystalline structure of ZnS nanocrystals simply by tuning sulfur precursor addition rate under exactly the same other conditions. We observed the structure of as prepared ZnS nanocrystals was evolved from wurtzite into zinc blende with increasing the addition rate of sulfur precursor. The method may extend to engineer other nanomaterials with desired physicochemical properties by controlling crystalline structure. On the other hand, it also makes a new approach to understand the crucial factors that determine the growth mechanism and the crystal structure of nanomaterials in theory.

  5. Sulfur dioxide control by electric utilities: What are the gains from trade?

    Science.gov (United States)

    Carlson, Curtis Paul

    1999-11-01

    Title IV of the 1990 Clean Air Act Amendments (CAAA) established a market for transferable sulfur dioxide (SO2) emission allowances among electric utilities. This market offers firms facing high marginal pollution abatement costs the opportunity to purchase the tight to emit SO2 from firms with lower costs; as such, it is expected to yield cost savings compared to a command-and-control approach to environmental regulation. This thesis uses econometrically estimated marginal abatement cost functions for power plants affected by Title IV of the CAAA to evaluate the performance of the SO2 allowance market. Specifically, I investigate whether the much-heralded fall in the cost of abating SO2, compared to original estimates, can be attributed to allowance trading. I demonstrate that, for plants that use low-sulfur coal to reduce SO2 emissions, technical change and the fall in low sulfur coal prices have lowered marginal abatement cost curves by over 50% since 1985. This is the main source of cost reductions rather than trading per se. In the long run, allowance trading may achieve cost savings of 700-800 million per year compared to an "enlightened" command and control program characterized by a uniform emission rate standard. However, a comparison of potential cost savings in 1995 and 1996 with actual emissions costs suggest that most trading gains were unrealized in the first two years of the program.

  6. Performance of a pilot-scale wet electrostatic precipitator for the control of sulfuric acid mist.

    Science.gov (United States)

    Huang, Jiayu; Wang, Hongmei; Shi, Yingjie; Zhang, Fan; Dang, Xiaoqing; Zhang, Hui; Shu, Yun; Deng, Shuang; Liu, Yu

    2016-10-01

    The use of a wet electrostatic precipitator (WESP) is often regarded as a viable option to reduce sulfuric acid mist emitted from the wet flue gas desulfurization (WFGD) tower in coal-fired power plants. In this study, a pilot-scale wet electrostatic precipitator equipped with a wall-cooled collection electrode is investigated for the control of sulfuric acid mist from a simulated WFGD system. The results show that due to partial charging effect, the removal efficiency of sulfuric acid aerosol decreases when the aerosol size decreases to several tens of nanometers. Moreover, due to the plasma-induced effect, a large number of ultrafine sulfuric acid aerosols below 50 nm formed at a voltage higher than 24 kV inside the WESP. The percentages of submicron-sized aerosols significantly increase together with the voltage. To minimize the adverse plasma-induced effect, a WESP should be operated at a high gas velocity with an optimum high voltage. Even at a high flue gas velocity of 2.3 m s(-1), the mass concentration and the total number concentration of uncaptured sulfuric acid aerosols at the WESP outlet are as low as ca. 0.6 mg m(-3) and ca. 10(4) 1 cm(-3) at 28 kV, respectively. The corresponding removal efficiencies were respectively higher than 99.4 and 99.9 % and are very similar to that at 1.1 and 1.6 m s(-1). Moreover, the condensation-induced aerosol growth enhances the removal of sulfuric acid mist inside a WESP and enables a low emission concentration of ca. 0.65 mg m(-3) with a corresponding removal efficiency superior to 99.4 % even at a low voltage of 21 kV, and of ca. 0.35 mg m(-3) with a corresponding removal efficiency superior to 99.6 % at a higher voltage level of 26 kV.

  7. Controllable synthesis of α-sulfur spheres with hierarchical nanostructures for efficient visible-light-driven photocatalytic ability

    Energy Technology Data Exchange (ETDEWEB)

    Dang, Xueming; Zhang, Xiufang, E-mail: zhangxf@dlpu.edu.cn; Zhang, Weiqiang; Dong, Xiaoli; Wang, Guowen; Ma, Hongchao

    2015-08-30

    Highlights: • α-Sulfur spheres with hierarchical nanostructures are controllably produced. • Addition quantity of PVP affects photocatalytic ability of α-sulfur. • The enhanced photocatalytic ability of α-sulfur hierarchical sphere is found. - Abstract: Visible-light-active α-sulfur spheres with hierarchical nanostructures were fabricated by simple solution-phase synthesis with PVP as the template for enhanced photocatalytic ability. The α-sulfur hierarchical spheres with an ultrahigh specific surface area can controllable synthesized by changing the addition quantity of PVP. The obtained products are systematically studied by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis absorption spectroscopy (DRS), Fluorescence (FL) and Brunauer-Emmett-Teller (BET). The photocatalytic activity of the as-prepared samples is evaluated by photocatalytic degradation of Rhodamine B (RhB) aqueous solution under visible light illumination. The results indicate that the morphology, specific surface area, photo absorbance ability, the separation efficiency of photogenerated carriers and the reactant adsorption performance can be controlled by varying the addition quantity of PVP. When 200 mg PVP is added, α-sulfur hierarchical spheres with uniform particle size about 1 μm and ultrahigh specific surface area of 67.1 m{sup 2}/g is obtained, and its photocatalytic activity reaches a maximum value, which can be attributed to the combined effects of photo absorbance ability, the separation efficiency of photogenerated carriers and the reactant adsorption performance.

  8. Spatial Dependence of Reduced Sulfur in Everglades Dissolved Organic Matter Controlled by Sulfate Enrichment.

    Science.gov (United States)

    Poulin, Brett A; Ryan, Joseph N; Nagy, Kathryn L; Stubbins, Aron; Dittmar, Thorsten; Orem, William H; Krabbenhoft, David P; Aiken, George R

    2017-03-01

    Sulfate inputs to the Florida Everglades stimulate sulfidic conditions in freshwater wetland sediments that affect ecological and biogeochemical processes. An unexplored implication of sulfate enrichment is alteration of the content and speciation of sulfur in dissolved organic matter (DOM), which influences the reactivity of DOM with trace metals. Here, we describe the vertical and lateral spatial dependence of sulfur chemistry in the hydrophobic organic acid (HPOA) fraction of DOM from unimpacted and sulfate-impacted Everglades wetlands using X-ray absorption spectroscopy and ultrahigh-resolution mass spectrometry. Spatial variation in DOM sulfur content and speciation reflects the degree of sulfate enrichment and resulting sulfide concentrations in sediment pore waters. Sulfur is incorporated into DOM predominantly as highly reduced species in sulfidic pore waters. Sulfur-enriched DOM in sediment pore waters exchanges with overlying surface waters and the sulfur likely undergoes oxidative transformations in the water column. Across all wetland sites and depths, the total sulfur content of DOM correlated with the relative abundance of highly reduced sulfur functionality. The results identify sulfate input as a primary determinant on DOM sulfur chemistry to be considered in the context of wetland restoration and sulfur and trace metal cycling.

  9. Spatial dependence of reduced sulfur in Everglades dissolved organic matter controlled by sulfate enrichment

    Science.gov (United States)

    Poulin, Brett A.; Ryan, Joseph N.; Nagy, Kathryn L.; Stubbins, Aron; Dittmar, Thorsten; Orem, William H.; Krabbenhoft, David P.; Aiken, George R.

    2017-01-01

    Sulfate inputs to the Florida Everglades stimulate sulfidic conditions in freshwater wetland sediments that affect ecological and biogeochemical processes. An unexplored implication of sulfate enrichment is alteration of the content and speciation of sulfur in dissolved organic matter (DOM), which influences the reactivity of DOM with trace metals. Here, we describe the vertical and lateral spatial dependence of sulfur chemistry in the hydrophobic organic acid fraction of DOM from unimpacted and sulfate-impacted Everglades wetlands using X-ray absorption spectroscopy and ultrahigh-resolution mass spectrometry. Spatial variation in DOM sulfur content and speciation reflects the degree of sulfate enrichment and resulting sulfide concentrations in sediment pore waters. Sulfur is incorporated into DOM predominantly as highly reduced species in sulfidic pore waters. Sulfur-enriched DOM in sediment pore waters exchanges with overlying surface waters and the sulfur likely undergoes oxidative transformations in the water column. Across all wetland sites and depths, the total sulfur content of DOM correlated with the relative abundance of highly reduced sulfur functionality. The results identify sulfate input as a primary determinant on DOM sulfur chemistry to be considered in the context of wetland restoration and sulfur and trace metal cycling.

  10. Ajoene, a Sulfur-Rich Molecule from Garlic, Inhibits Genes Controlled by Quorum Sensing

    DEFF Research Database (Denmark)

    Jakobsen, Tim Holm; van Gennip, Maria; Phipps, Richard Kerry

    2012-01-01

    the expression of specific genes involved in pathogenicity, is a possible drug target. Previous in vitro and in vivo studies revealed a significant inhibition of P. aeruginosa QS by crude garlic extract. By bioassay-guided fractionation of garlic extracts, we determined the primary QS inhibitor present in garlic...... to be ajoene, a sulfur-containing compound with potential as an antipathogenic drug. By comprehensive in vitro and in vivo studies, the effect of synthetic ajoene toward P. aeruginosa was elucidated. DNA microarray studies of ajoene-treated P. aeruginosa cultures revealed a concentration-dependent attenuation...... model of pulmonary infection, a significant clearing of infecting P. aeruginosa was detected in ajoene-treated mice compared to a nontreated control group. This study adds to the list of examples demonstrating the potential of QS-interfering compounds in the treatment of bacterial infections....

  11. Controlled exposure of volunteers with chronic obstructive pulmonary disease to sulfur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Linn, W.S.; Fischer, D.A.; Shamoo, D.A.; Spier, C.E.; Valencia, L.M.; Anzar, U.T.; Hackney, J.D.

    1985-08-01

    Twenty-four volunteers with chronic obstructive pulmonary disease (COPD) were exposed to sulfur dioxide (SO/sub 2/) at 0, 0.4, and 0.8 ppm in an environmental control chamber. Exposures lasted 1 hr and included two 15-min exercise periods (mean exercise ventilation rate 18 liter/min). Pulmonary mechanical function was evaluated before exposures, after initial exercise, and at the end of exposure. Blood oxygenation was measured by ear oximetry before exposure and during the second exercise period. Symptoms were recorded throughout exposure periods and for 1 week afterward. No statistically significant changes in physiology or symptoms could be attributed to SO/sub 2/ exposure. Older adults with COPD seem less reactive to a given concentration of SO/sub 2/ than heavily exercising young adult asthmatics. This may be due to lower ventilation rates (i.e., lower SO/sub 2/ dose rates) and/or to lower airway reactivity in the COPD group.

  12. Identification of control parameters for the sulfur gas storability with bag sampling methods

    Science.gov (United States)

    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))...

  13. Controlled Growth of Platinum Nanowire Arrays on Sulfur Doped Graphene as High Performance Electrocatalyst

    Science.gov (United States)

    Wang, Rongyue; Higgins, Drew C.; Hoque, Md Ariful; Lee, DongUn; Hassan, Fathy; Chen, Zhongwei

    2013-01-01

    Graphene supported Pt nanostructures have great potential to be used as catalysts in electrochemical energy conversion and storage technologies; however the simultaneous control of Pt morphology and dispersion, along with ideally tailoring the physical properties of the catalyst support properties has proven very challenging. Using sulfur doped graphene (SG) as a support material, the heterogeneous dopant atoms could serve as nucleation sites allowing for the preparation of SG supported Pt nanowire arrays with ultra-thin diameters (2–5 nm) and dense surface coverage. Detailed investigation of the preparation technique reveals that the structure of the resulting composite could be readily controlled by fine tuning the Pt nanowire nucleation and growth reaction kinetics and the Pt-support interactions, whereby a mechanistic platinum nanowire array growth model is proposed. Electrochemical characterization demonstrates that the composite materials have 2–3 times higher catalytic activities toward the oxygen reduction and methanol oxidation reaction compared with commercial Pt/C catalyst. PMID:23942256

  14. Morphology control of ordered mesoporous carbons for high capacity lithium sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Joerg David

    2011-06-07

    The focus of this thesis concerns the morphology control of ordered mesoporous carbon (OMC) materials. Ordered mesoporous carbons with diverse morphologies, that are thin films, fibers - embedded in anodic alumina membranes and free-standing - or spherical nanoparticles, have been successfully prepared by soft-templating procedures. The mechanisms of structure formation and processing were investigated with in-situ SAXS measurements and their application in high capacity lithium-sulfur batteries was successfully tested in cooperation with Guang He and Linda Nazar from the University of Waterloo in Canada. The Li-S batteries receive increasing attention due to their high theoretical energy density which is 3 to 5 times higher than from lithium-ion batteries. For this type of battery the specific pore volume is crucial for the content of the active component (sulfur) in the cathode and therefore correlates with the capacity and gravimetric energy density of the battery. At first, mesoporous thin films with 2D-hexagonal structure were obtained through organic-organic self-assembly of a preformed oligomeric resol precursor and the triblock copolymer template Pluronic P123. The formation of a condensed-wall material through thermopolymerization of the precursor oligomers resulted in mesostructured phenolic resin films. Subsequent decomposition of the surfactant and partial carbonization were achieved through thermal treatment in inert atmosphere. The films were crack-free with tunable homogenous thicknesses, and showed either 2D-hexagonal or lamellar mesostructure. An additional, yet unknown 3D-mesostructure was also found. In the second part, cubic and circular hexagonal mesoporous carbon phases in the confined environment of tubular anodic alumina membrane (AAM) pores were obtained by self-assembly of the mentioned resol precursor and the triblock copolymer templates Pluronic F127 or P123, respectively. Casting and solvent-evaporation were also followed by

  15. Sulfur Content Precision Control Technology for CO2-Shielded Welding Wire Steel

    Science.gov (United States)

    Chaofa, Zhang; Huaqiang, Hao; Youbing, Xiang; Shanxi, Liu

    As a kind of impurity and displaying with FeS and MnS form in steel, Sulfur can make the disadvantage effect on the performance of hot-working, welding and corrosion resistance. The high content sulfur in steel can cause the hot brittle phenomenon for the steel. For the welding steel, when the sulfur content is higher, the drawing performance of wire rod become worst and the yield of wire rod decrease. When the sulfur is lower, the automatic wire feeding performance for the gas shielded welding become worst and the weld seam is not smooth. According to the results of welding expert research, 0.010%≤ S≤ 0.020% in CO2-shielded welding wire steel is reasonable.

  16. Control strategy for sulfur dioxide and acid rain pollution inChinaa

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Several factors, namely, coal-dominated primary energy mix, extensive economic development mode, inefficient energy utilization, end the imperfect environmental regulations, result in the serious urban sulfur dioxide pollution end large-scale sulfatetype acid precipitation in China. In 1995, China's sulfur dioxide emissions reached 23.70 Mt, and the areas affected by acid rain accounted for 40% of the territory. Chinese government accords considerable importance to the sulfur dioxide end acid rain contamination. New sets of environmental friendly policies have been promulgated. But enforcement of laws and regulations on SO2 emissions need to be further improved and broadened, especially those respond to market conditions. This paper focuses particular attention on the analysis of strategy, policies, and national actions which had or should be taken against sulfur dioxide emissions nationwide to achieve the environmental targets, on the basis of which gives the technical options in future.

  17. Perinatal sulfur dioxide exposure alters brainstem parasympathetic control of heart rate.

    Science.gov (United States)

    Woerman, Amanda L; Mendelowitz, David

    2013-07-01

    Sulfur dioxide (SO₂) is an air pollutant that impedes neonatal development and induces adverse cardiorespiratory health effects, including tachycardia. Here, an animal model was developed that enabled characterization of (i) in vivo alterations in heart rate and (ii) altered activity in brainstem neurons that control heart rate after perinatal SO₂ exposure. Pregnant Sprague-Dawley dams and their pups were exposed to 5 parts per million SO₂ for 1 h daily throughout gestation and 6 days postnatal. Electrocardiograms were recorded from pups at 5 days postnatal to examine changes in basal and diving reflex-evoked changes in heart rate following perinatal SO₂ exposure. In vitro studies employed whole-cell patch-clamp electrophysiology to examine changes in neurotransmission to cardiac vagal neurons within the nucleus ambiguus upon SO₂ exposure using a preparation that maintains fictive inspiratory activity recorded from the hypoglossal rootlet. Perinatal SO₂ exposure increased heart rate and blunted the parasympathetic-mediated diving reflex-evoked changes in heart rate. Neither spontaneous nor inspiratory-related inhibitory GABAergic or glycinergic neurotransmission to cardiac vagal neurons was altered by SO₂ exposure. However, excitatory glutamatergic neurotransmission was decreased by 51.2% upon SO₂ exposure. This diminished excitatory neurotransmission was tetrodotoxin-sensitive, indicating SO₂ exposure impaired the activity of preceding glutamatergic neurons that synapse upon cardiac vagal neurons. Diminished glutamatergic, but unaltered inhibitory neurotransmission to cardiac vagal neurons provides a mechanism for the observed SO₂-induced elevated heart rate via an impairment of brainstem cardioinhibitory parasympathetic activity to the heart.

  18. Morphology control of ordered mesoporous carbons for high capacity lithium sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Joerg David

    2011-06-07

    The focus of this thesis concerns the morphology control of ordered mesoporous carbon (OMC) materials. Ordered mesoporous carbons with diverse morphologies, that are thin films, fibers - embedded in anodic alumina membranes and free-standing - or spherical nanoparticles, have been successfully prepared by soft-templating procedures. The mechanisms of structure formation and processing were investigated with in-situ SAXS measurements and their application in high capacity lithium-sulfur batteries was successfully tested in cooperation with Guang He and Linda Nazar from the University of Waterloo in Canada. The Li-S batteries receive increasing attention due to their high theoretical energy density which is 3 to 5 times higher than from lithium-ion batteries. For this type of battery the specific pore volume is crucial for the content of the active component (sulfur) in the cathode and therefore correlates with the capacity and gravimetric energy density of the battery. At first, mesoporous thin films with 2D-hexagonal structure were obtained through organic-organic self-assembly of a preformed oligomeric resol precursor and the triblock copolymer template Pluronic P123. The formation of a condensed-wall material through thermopolymerization of the precursor oligomers resulted in mesostructured phenolic resin films. Subsequent decomposition of the surfactant and partial carbonization were achieved through thermal treatment in inert atmosphere. The films were crack-free with tunable homogenous thicknesses, and showed either 2D-hexagonal or lamellar mesostructure. An additional, yet unknown 3D-mesostructure was also found. In the second part, cubic and circular hexagonal mesoporous carbon phases in the confined environment of tubular anodic alumina membrane (AAM) pores were obtained by self-assembly of the mentioned resol precursor and the triblock copolymer templates Pluronic F127 or P123, respectively. Casting and solvent-evaporation were also followed by

  19. Control and treatment of sulfur oxides emissions; Prevention et traitement des emissions d`oxydes de soufre

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    The conference on the control and treatment of sulfur oxides emissions has held in Le Havre the 4. and 5. december, 1997. The aim of this conference was to promote the information on the different treatment technologies and to contribute on the one hand to the supporting and revival of the environmental protection and on the other hand to the desulfurization programs. It has allowed to recall too the technical and financial support of the Ademe to the manufacturers. (O.M.)

  20. Combined nitrogen oxides/sulfur dioxide control in dry scrubber systems

    Energy Technology Data Exchange (ETDEWEB)

    Harkness, J. B.L.; Gorski, A. J.; Huang, H. S.

    1989-02-01

    Argonne National Laboratory (ANL) is investigating alternative control concepts that involve modifying existing SO{sub 2}-removal processes and sorbents, with the objective of achieving simultaneous removal of nitrogen oxides (NO{sub x}) and sulfur dioxide (SO{sub 2}). Laboratory-scale research conducted using a fixed-bed reactor and a spray-dryer/fabric-filter system has been paralleled by field tests at ANL's commercial-scale (20-MW electric equivalent) dry scrubber. In the fixed-bed experiments, a range of chemical reagents was surveyed, and the best-performing additives were studied in detail. Sodium chloride, sodium bisulfite, sodium hydroxide, and Fe(II)*EDTA were found to increase both NO{sub x} and SO{sub 2} removals; the additives did not appear to increase NO{sub x} removal directly, but they interacted strongly with the other primary variables to improve sorbent performance. The laboratory spray-dryer system was used to study the effects on combined NO{sub x}/SO{sub 2} removal of the best-performing fixed-bed additives and certain process modifications. The tests showed that sodium chloride increased NO{sub x} removal at all temperatures; sodium bisulfite was generally less effective, and calcium chloride was effective only at 65{degree}C. Up to 80{degree}C, all three additives significantly improved SO{sub 2} removal, but improvement ceased at higher temperatures. This report discusses the experimental results in terms of the effects the additives and principal process variables had on NO{sub x} and SO{sub 2} removals and the mechanistic implications. 14 refs., 74 figs., 33 tabs.

  1. Dynamic behavior of the bray-liebhafsky oscillatory reaction controlled by sulfuric acid and temperature

    Science.gov (United States)

    Pejić, N.; Vujković, M.; Maksimović, J.; Ivanović, A.; Anić, S.; Čupić, Ž.; Kolar-Anić, Lj.

    2011-12-01

    The non-periodic, periodic and chaotic regimes in the Bray-Liebhafsky (BL) oscillatory reaction observed in a continuously fed well stirred tank reactor (CSTR) under isothermal conditions at various inflow concentrations of the sulfuric acid were experimentally studied. In each series (at any fixed temperature), termination of oscillatory behavior via saddle loop infinite period bifurcation (SNIPER) as well as some kind of the Andronov-Hopf bifurcation is presented. In addition, it was found that an increase of temperature, in different series of experiments resulted in the shift of bifurcation point towards higher values of sulfuric acid concentration.

  2. 40 CFR 52.125 - Control strategy and regulations: Sulfur oxides.

    Science.gov (United States)

    2010-07-01

    ...) of the Clean Air Act. (2) The approval of paragraphs A and F of regulation 7-1-4.2 as to coal fired...)and 123(a)(2) of the Clean Air Act. (g) Section 3, Regulation 3 (Sulfur from Primary Copper Smelters... section 110(a)(2)(B) of the Clean Air Act. Editorial Note: For Federal Register citations affecting §...

  3. 40 CFR 52.2731 - Control strategy and regulations: Sulfur oxides.

    Science.gov (United States)

    2010-07-01

    ... the national standards for sulfur oxides in the areas of Aguirre, Barceloneta, Trujillo Alto-Dorado... section is disapproved for the following facilities: Puerto RicoWater Resources Authority—Aguirre Complex... exception of the Puerto Rico Water Resources Authority—Aguirre Complex, are required to conform to...

  4. Studies on the effectiveness of various sulfur fertilizers under controlled conditions

    NARCIS (Netherlands)

    Dijksterhuis, G.H.; Oenema, O.

    1990-01-01

    Three factorial experiments with four replications were conducted in a greenhouse to examine the effectiveness of gypsum, elemental sulfur (ES powder) and three S containing N fertilizers, viz., ammonium sulfate (AS), urea ES, and Ureas (20% AS and 80% urea). All experiments were conducted twice in

  5. Sorbent Injection for Small ESP Mercury Control in Low Sulfur Eastern Bituminous Coal Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Carl Richardson; Katherine Dombrowski; Douglas Orr

    2006-12-31

    This project Final Report is submitted to the U.S. Department of Energy (DOE) as part of Cooperative Agreement DE-FC26-03NT41987, 'Sorbent Injection for Small ESP Mercury Control in Low Sulfur Eastern Bituminous Coal Flue Gas.' Sorbent injection technology is targeted as the primary mercury control process on plants burning low/medium sulfur bituminous coals equipped with ESP and ESP/FGD systems. About 70% of the ESPs used in the utility industry have SCAs less than 300 ft2/1000 acfm. Prior to this test program, previous sorbent injection tests had focused on large-SCA ESPs. This DOE-NETL program was designed to generate data to evaluate the performance and economic feasibility of sorbent injection for mercury control at power plants that fire bituminous coal and are configured with small-sized electrostatic precipitators and/or an ESP-flue gas desulfurization (FGD) configuration. EPRI and Southern Company were co-funders for the test program. Southern Company and Reliant Energy provided host sites for testing and technical input to the project. URS Group was the prime contractor to NETL. ADA-ES and Apogee Scientific Inc. were sub-contractors to URS and was responsible for all aspects of the sorbent injection systems design, installation and operation at the different host sites. Full-scale sorbent injection for mercury control was evaluated at three sites: Georgia Power's Plant Yates Units 1 and 2 [Georgia Power is a subsidiary of the Southern Company] and Reliant Energy's Shawville Unit 3. Georgia Power's Plant Yates Unit 1 has an existing small-SCA cold-side ESP followed by a Chiyoda CT-121 wet scrubber. Yates Unit 2 is also equipped with a small-SCA ESP and a dual flue gas conditioning system. Unit 2 has no SO2 control system. Shawville Unit 3 is equipped with two small-SCA cold-side ESPs operated in series. All ESP systems tested in this program had SCAs less than 250 ft2/1000 acfm. Short-term parametric tests were conducted on Yates

  6. Pressurized fluidized-bed hydroretorting of Eastern oil shales -- Sulfur control. Topical report for Subtask 3.1, In-bed sulfur capture tests; Subtask 3.2, Electrostatic desulfurization; Subtask 3.3, Microbial desulfurization and denitrification

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, M.J.; Abbasian, J.; Akin, C.; Lau, F.S.; Maka, A.; Mensinger, M.C.; Punwani, D.V.; Rue, D.M. [Institute of Gas Technology, Chicago, IL (United States); Gidaspow, D.; Gupta, R.; Wasan, D.T. [Illinois Inst. of Tech., Chicago, IL (United States); Pfister, R.M.: Krieger, E.J. [Ohio State Univ., Columbus, OH (United States)

    1992-05-01

    This topical report on ``Sulfur Control`` presents the results of work conducted by the Institute of Gas Technology (IGT), the Illinois Institute of Technology (IIT), and the Ohio State University (OSU) to develop three novel approaches for desulfurization that have shown good potential with coal and could be cost-effective for oil shales. These are (1) In-Bed Sulfur Capture using different sorbents (IGT), (2) Electrostatic Desulfurization (IIT), and (3) Microbial Desulfurization and Denitrification (OSU and IGT). The objective of the task on In-Bed Sulfur Capture was to determine the effectiveness of different sorbents (that is, limestone, calcined limestone, dolomite, and siderite) for capturing sulfur (as H{sub 2}S) in the reactor during hydroretorting. The objective of the task on Electrostatic Desulfurization was to determine the operating conditions necessary to achieve a high degree of sulfur removal and kerogen recovery in IIT`s electrostatic separator. The objectives of the task on Microbial Desulfurization and Denitrification were to (1) isolate microbial cultures and evaluate their ability to desulfurize and denitrify shale, (2) conduct laboratory-scale batch and continuous tests to improve and enhance microbial removal of these components, and (3) determine the effects of processing parameters, such as shale slurry concentration, solids settling characteristics, agitation rate, and pH on the process.

  7. Use of nahcolite ore and bag filters for sulfur dioxide emission control

    Energy Technology Data Exchange (ETDEWEB)

    Genco, J.M. (Univ. of Maine, Orono); Rosenberg, H.S.; Anastas, M.Y.; Rosar, E.C.; Dulin, J.M.

    1975-12-01

    Technical and economic aspects of the nahcolite ore injection process for the simultaneous removal of fly ash and sulfur oxides from stack gases are described. The process is capable of removing greater than 99 percent of the particulate matter and greater than 70 percent of the sulfur oxides present in such gases. The technical feasibility of the process has been demonstrated in both bench scale and pilot scale engineering studies. Economic analyses performed for the cases of plants located in the midwest and southwest indicate lower capital costs for the nahcolite injection process when compared to wet scrubbing. On an annual cost basis, the nahcolite ore injection process is comparable in cost to wet scrubbing for the case of the southwestern power plant, and somewhat more expensive for the case of the midwestern plant.

  8. Controls on stable sulfur isotope fractionation during bacterial sulfate reduction in Arctic sediments

    DEFF Research Database (Denmark)

    Bruchert, V.; Knoblauch, C.; Jørgensen, BB

    2001-01-01

    Sulfur isotope fractionation experiments during bacterial sulfate reduction were performed with recently isolated strains of cold-adapted sulfate-reducing bacteria from Arctic marine sediments with year-round temperatures below 2 degreesC. The bacteria represent quantitatively important members...... parts per thousand and 8 parts per thousand above 25 degreesC, respectively. In absence of significant differences in sulfate reduction rates in the high and low temperature range, respectively, we infer that different genera of sulfate-reducing bacteria dominate the sulfate-reducing bacterial community...

  9. Combinatorial control of diverse metabolic and physiological functions by transcriptional regulators of the yeast sulfur assimilation pathway.

    Science.gov (United States)

    Petti, Allegra A; McIsaac, R Scott; Ho-Shing, Olivia; Bussemaker, Harmen J; Botstein, David

    2012-08-01

    Methionine abundance affects diverse cellular functions, including cell division, redox homeostasis, survival under starvation, and oxidative stress response. Regulation of the methionine biosynthetic pathway involves three DNA-binding proteins-Met31p, Met32p, and Cbf1p. We hypothesized that there exists a "division of labor" among these proteins that facilitates coordination of methionine biosynthesis with diverse biological processes. To explore combinatorial control in this regulatory circuit, we deleted CBF1, MET31, and MET32 individually and in combination in a strain lacking methionine synthase. We followed genome-wide gene expression as these strains were starved for methionine. Using a combination of bioinformatic methods, we found that these regulators control genes involved in biological processes downstream of sulfur assimilation; many of these processes had not previously been documented as methionine dependent. We also found that the different factors have overlapping but distinct functions. In particular, Met31p and Met32p are important in regulating methionine metabolism, whereas p functions as a "generalist" transcription factor that is not specific to methionine metabolism. In addition, Met31p and Met32p appear to regulate iron-sulfur cluster biogenesis through direct and indirect mechanisms and have distinguishable target specificities. Finally, CBF1 deletion sometimes has the opposite effect on gene expression from MET31 and MET32 deletion.

  10. [Effects of sulfur- and polymer-coated controlled release urea fertilizers on wheat yield and quality and fertilizer nitrogen use efficiency].

    Science.gov (United States)

    Ma, Fu-Liang; Song, Fu-Peng; Gao, Yang; Zou, Peng

    2012-01-01

    A field experiment was conducted to study the effects of sulfur- and polymer-coated controlled release urea fertilizers on wheat yield and its quality, plow layer soil inorganic nitrogen (N) contents, and fertilizer N use efficiency. Compared with traditional urea fertilizer, both sulfur- and polymer-coated controlled release urea fertilizers increased the grain yield by 10.4%-16.5%, and the grain protein and starch contents by 5.8%-18.9% and 0.3%-1.4%, respectively. The controlled release urea fertilizers could maintain the topsoil inorganic N contents to meet the N requirement for the wheat, especially during its late growth stage. In the meantime, the fertilizer N use efficiency was improved by 58.2%-101.2%. Polymer-coated urea produced better wheat yield and higher fertilizer N use efficiency, compared with sulfur-coated controlled release urea.

  11. Analysis of the sulfur-regulated control of the cystathionine γ-lyase gene of Neurospora crassa

    Directory of Open Access Journals (Sweden)

    Reveal Brad S

    2012-07-01

    Full Text Available Abstract Background Cystathionine γ-lyase plays a key role in the transsulfuration pathway through its primary reaction of catalyzing the formation of cysteine from cystathionine. The Neurospora crassa cystathionine γ-lyase gene (cys-16+ is of particular interest in dissecting the regulation and dynamics of transsulfuration. The aim of this study was to determine the regulatory connection of cys-16+ to the Neurospora sulfur regulatory network. In addition, the cys-16+ promoter was characterized with the goal of developing a strongly expressed and regulatable gene expression tool. Findings The cystathionine γ-lyase cys-16+ gene was cloned and characterized. The gene, which contains no introns, encodes a protein of 417 amino acids with conserved pyridoxal 5’-phosphate binding site and substrate-cofactor binding pocket. Northern blot analysis using wild type cells showed that cys-16+ transcript levels increased under sulfur limiting (derepressing conditions and were present only at a low level under sulfur sufficient (repressing conditions. In contrast, cys-16+ transcript levels in a Δcys-3 regulatory mutant were present at a low level under either derepressing or repressing conditions. Gel mobility shift analysis demonstrated the presence of four CYS3 transcriptional activator binding sites on the cys-16+ promoter, which were close matches to the CYS3 consensus binding sequence. Conclusions In this work, we confirm the control of cystathionine γ-lyase gene expression by the CYS3 transcriptional activator through the loss of cys-16+ expression in a Δcys-3 mutant and through the in vitro binding of CYS3 to the cys-16+ promoter at four sites. The highly regulated cys-16+ promoter should be a useful tool for gene expression studies in Neurospora

  12. Fluoride and sulfur dioxide indoor pollution situation and control in coal-burning endemic area in Zhaotong, Yunnan, China

    Science.gov (United States)

    Liu, Yonglin; Luo, Kunli; Li, Ling; Shahid, Muhammad Zeeshaan

    2013-10-01

    , gaseous fluoride and SO2 concentration in the traditional flue-curing barn air have declined markedly. The way of adding calcined dolomitic siliceous limestone instead of clay as a binder for briquette-making is an economically feasible way to control the indoor pollution of fluorine and sulfur in coal-burning endemic in Zhaotong, Yunnan.

  13. Treatment of air pollution control residues with iron rich waste sulfuric acid: does it work for antimony (Sb)?

    Science.gov (United States)

    Okkenhaug, Gudny; Breedveld, Gijs D; Kirkeng, Terje; Lægreid, Marit; Mæhlum, Trond; Mulder, Jan

    2013-03-15

    Antimony (Sb) in air pollution control (APC) residues from municipal solid waste incineration has gained increased focus due to strict Sb leaching limits set by the EU landfill directive. Here we study the chemical speciation and solubility of Sb at the APC treatment facility NOAH Langøya (Norway), where iron (Fe)-rich sulfuric acid (∼3.6M, 2.3% Fe(II)), a waste product from the industrial extraction of ilmenite, is used for neutralization. Antimony in water extracts of untreated APC residues occurred exclusively as pentavalent antimonate, even at low pH and Eh values. The Sb solubility increased substantially at pHSb in porewater, occurring exclusively as Sb(V). Concentrations of Sb decreased from 87-918μgL(-1) (day 3) to 18-69μgL(-1) (day 600). We hypothesize that an initial sorption of Sb to Fe(II)-Fe(III) hydroxides (green rust) and eventually precipitation of Ca- and Fe-antimonates (tripuhyite; FeSbO4) occurred. We conclude that Fe-rich, sulfuric acid waste is efficient to immobilize Sb in APC residues from waste incineration.

  14. Lunar sulfur

    Science.gov (United States)

    Kuck, David L.

    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.

  15. Improved Recovery Boiler Performance Through Control of Combustion, Sulfur, and Alkali Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Larry L.

    2008-06-09

    This project involved the following objectives: 1. Determine black liquor drying and devolatilization elemental and total mass release rates and yields. 2. Develop a public domain physical/chemical kinetic model of black liquor drop combustion, including new information on drying and devolatilization. 3. Determine mechanisms and rates of sulfur scavenging in recover boilers. 4. Develop non-ideal, public-domain thermochemistry models for alkali salts appropriate for recovery boilers 5. Develop data and a one-dimensional model of a char bed in a recovery boiler. 6. Implement all of the above in comprehensive combustion code and validate effects on boiler performance. 7. Perform gasification modeling in support of INEL and commercial customers. The major accomplishments of this project corresponding to these objectives are as follows: 1. Original data for black liquor and biomass data demonstrate dependencies of particle reactions on particle size, liquor type, gas temperature, and gas composition. A comprehensive particle submodel and corresponding data developed during this project predicts particle drying (including both free and chemisorbed moisture), devolatilization, heterogeneous char oxidation, char-smelt reactions, and smelt oxidation. Data and model predictions agree, without adjustment of parameters, within their respective errors. The work performed under these tasks substantially exceeded the original objectives. 2. A separate model for sulfur scavenging and fume formation in a recovery boiler demonstrated strong dependence on both in-boiler mixing and chemistry. In particular, accurate fume particle size predictions, as determined from both laboratory and field measurements, depend on gas mixing effects in the boilers that lead to substantial particle agglomeration. Sulfur scavenging was quantitatively predicted while particle size required one empirical mixing factor to match data. 3. Condensed-phase thermochemistry algorithms were developed for salt

  16. Environmental Controls on Nitrogen and Sulfur Cycles in Surficial Aquatic Sediments

    Directory of Open Access Journals (Sweden)

    Chuanhui eGu

    2012-02-01

    Full Text Available Enhanced anthropogenic inputs of nitrogen (N and sulfur (S have disturbed their biogeochemical cycling in aquatic and terrestrial ecosystems. The N and S cycles interact with one another through competition for labile forms of organic carbon between nitrate-reducing and sulfate-reducing bacteria. Furthermore, the N and S cycles could interact through nitrate (NO3- reduction coupled to S oxidation, consuming NO3- and producing sulfate (SO42-. The research questions of this study were: (1 what are the environmental factors explaining variability in N and S biogeochemical reaction rates in a wide range of surficial aquatic sediments, and (2 which biogeochemical processes are involved when NO3- and/or SO42- are present. The N and S biogeochemical reaction rates were measured on intact surface sediment slices using flow-through reactors. The two terminal electron acceptors (TEA NO3- and SO42- were added either separately or simultaneously and NO3- and SO42- reduction rates as well as NO3- reduction linked to S oxidation were determined. We used redundancy analysis, to assess how environmental variables are related to these rates. Our analysis showed that overlying water pH and salinity were two dominant environmental factors that explain 58% of the variance in the N and S biogeochemical reaction rates when NO3- and SO42- were both present. When NO3- and SO42- were added separately, however, sediment N content in addition to pH and salinity accounted for 62% of total variance of the biogeochemical reaction rates. The SO42- addition had little effect on NO3- reduction; neither did the NO3- addition inhibit SO42- reduction. The presence of NO3- led to SO42- production most likely due to the oxidation of sulfur. Our observations suggest that metal-bound S, instead of free sulfide produced by SO42- reduction, was responsible the S oxidation. The subsequent release of toxic metals from this coupling might have adverse effects on aquatic ecosystems.

  17. Growth of Pd{sub 4}S, PdS and PdS{sub 2} films by controlled sulfurization of sputtered Pd on native oxide of Si

    Energy Technology Data Exchange (ETDEWEB)

    Bhatt, R., E-mail: rbhatt@barc.gov.in [Technical Physics Division, Bhabha Atomic Research Center, Mumbai–400 085 (India); Bhattacharya, S.; Basu, R.; Singh, A. [Technical Physics Division, Bhabha Atomic Research Center, Mumbai–400 085 (India); Deshpande, U. [UGC–DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore–452017 (India); Surger, C. [Karlsruhe Institute of Technology, Physikalisches Institut and DFG Center for Functional Nanostructures, P.O. Box 6980, D–76049 Karlsruhe (Germany); Basu, S. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai-400 085 (India); Aswal, D.K.; Gupta, S.K. [Technical Physics Division, Bhabha Atomic Research Center, Mumbai–400 085 (India)

    2013-07-31

    Thin films of different Pd–S phase, namely Pd{sub 4}S, PdS and PdS{sub 2}, have been reproducibly grown by the sulfurization of Pd films deposited on native oxide of (111) Si substrates by radio frequency sputtering method. In order to achieve controlled sulfurization, a three-stage sulfurization setup consisting of evaporation chamber, activation chamber and sulfurization chamber has been developed. The sulfurization of Pd films (kept at a constant temperature of 500 °C) was carried out using sulfur vapors activated to different temperature between 550 and 700 °C. The results of X-ray diffraction and X-ray photoelectron spectroscopy measurements show that formation of Pd{sub 4}S, PdS and PdS{sub 2} phases takes place for the activation temperatures of 550, 600 and 700 °C, respectively. The room temperature resistivity of Pd, Pd{sub 4}S, PdS and PdS{sub 2} were found to be respectively 0.1, 15.9, 15,000 and 20,000 μΩ cm. The temperature-dependent electrical resistivity measurements showed metallic conduction for Pd and Pd{sub 4}S films. The Seebeck coefficient measured at 300 K for these Pd–S phases showed their n-type conducting behavior. - Highlights: • Multichamber sulfurization setup designed for preparing thin films of Pd–S. • S vapor activated at 550, 600 and 700 °C results in Pd{sub 4}S, PdS and PdS{sub 2} phases. • The Seebeck coefficient of Pd–S phases shows their n-type conducting behavior. • Transport properties of Pd{sub 4}S phase show that it is a metallic phase. • High resistivity and thermopower of PdS and PdS{sub 2} show semiconducting nature.

  18. Hydrophilicity-controlled ordered mesoporous carbon for lithium-sulfur batteries.

    Science.gov (United States)

    Bae, Suyeon; Jin, Xing; Park, Gwi Ok; Kim, Ji Man

    2014-12-01

    Ordered mesoporous carbon (OMC) materials were synthesized from a mesoporous silica KIT-6 (3-D cubic la3d meso-structure) as the hard-template via a nano-replication method. Hydrophilic and hydrophobic OMC materials were prepared using different carbon precursors including sucrose (suc-OMC) and phenanthrene (phe-OMC) at different carbonization temperatures of 700 degrees C and 1100 degrees C, respectively. The OMC materials thus obtained exhibit high surface areas, uniform mesopore sizes and highly ordered meso-structure. To investigate the hydrophilicity effect of OMC materials on the performance of lithium-sulfur battery, we prepared the samples having different ratios of the suc-OMC to phe-OMC, which were 100:0, 75:25, 50:50, 25:75 and 0:100. As a result, the mixed OMC materials (with ratios of 75:25, 50:50 and 25:75) exhibited better cycle performances, compared to those of the suc-OMC and phe-OMC.

  19. MicroRNA-210 Controls Mitochondrial Metabolism during Hypoxia by Repressing the Iron-Sulfur Cluster Assembly Proteins ISCU1/2

    Science.gov (United States)

    Chan, Stephen Y.; Zhang, Ying-Yi; Hemann, Craig; Mahoney, Christopher E.; Zweier, Jay L.; Loscalzo, Joseph

    2009-01-01

    Summary Repression of mitochondrial respiration represents an evolutionarily ancient cellular adaptation to hypoxia and profoundly influences cell survival and function; however, the underlying molecular mechanisms are incompletely understood. Primarily utilizing pulmonary arterial endothelial cells as a representative hypoxic cell type, we identify the iron-sulfur cluster assembly proteins (ISCU1/2) as direct targets for repression by the hypoxia-induced microRNA-210 (miR-210). ISCU1/2 facilitate the assembly of iron-sulfur clusters, prosthetic groups that are critical for electron transport and mitochondrial oxidation-reduction reactions. Under in vivo conditions of up-regulating miR-210 and repressing ISCU1/2, the integrity of iron-sulfur clusters is disrupted. In turn, by repressing ISCU1/2 during hypoxia, miR-210 decreases the activity of prototypical iron-sulfur proteins controlling mitochondrial metabolism, including Complex I and aconitase. Consequently, miR-210 represses mitochondrial respiration and associated downstream functions. These results identify important mechanistic connections among microRNA, iron-sulfur cluster biology, hypoxia, and mitochondrial function, with broad implications for cellular metabolism and adaptation to cellular stress. PMID:19808020

  20. Layer number controllability of transition-metal dichalcogenides and the establishment of hetero-structures by using sulfurization of thin transition metal films

    Science.gov (United States)

    Chen, Kuan-Chao; Chu, Tung-Wei; Wu, Chong-Rong; Lee, Si-Chen; Lin, Shih-Yen

    2017-02-01

    Large-area and uniform MoS2 films are fabricated by using sulfurization of pre-deposited molybdenum (Mo) films. One- and three-layer MoS2 films are obtained by sulfurizing 0.5 and 1.0 nm Mo films, respectively. The results have demonstrated the good layer number controllability of this growth technique down to single-layer MoS2. By sequential sulfurization of 0.5 nm W, 0.5 nm Mo and 0.5 nm W under the same condition, three layers of the WS2/MoS2/WS2 hetero-structure are established, which has demonstrated the potential of this growth technique for the establishment of 2D crystal hetero-structures.

  1. 基于硫平衡计算的低硫烧结原料控制标准%Control criterion of low-sulfur sintering materials based on sulfur balance calculations

    Institute of Scientific and Technical Information of China (English)

    刘征建; 张建良; 安钢; 杨天钧

    2012-01-01

    首先根据首钢京唐钢铁公司烧结生产数据进行系统的硫平衡计算,分析各种烧结原料对废气中SO2排放量的影响权重,并在此基础上作合理假设,结合国家标准对于不同烧结机SO2排放量的统一计量方法,推导出烧结原料硫含量与SO2排放量判定指标的关系式,建立低硫烧结原料控制标准.首钢京唐钢铁公司烧结生产若要满足500mg.m-3的SO2质量浓度限值,需要将混合料中硫的质量分数降至0.032%以下;若要满足200 mg.m-3的SO2质量浓度限值,需要将混合料硫的质量分数降至0.013%以下,而这在当前的原料条件下是难以实现的.%Sulfur balance calculations were performed according to production data from Shougang Jingtang Steel Sintering Plant.The impact weight of each sintering material on SO2 concentration in sintering waste gas was analyzed,based on which some reasonable assumptions were made.In combination with the uniform measurement method of SO2 emission concentration for different sintering machines in Chinese standards,a relation formula between sulfur content in the sintering materials and judging index for SO2 emission concentration was deduced and a control criterion for low-sulfur sintering materials was established.If Shougang Jingtang Steel Sintering Plant wants to meet the SO2 emission concentration of 500 mg·m-3,the sulfur content in the sintering mixture need reduce to below 0.032%;if it wants to meet the SO2 emission concentration of 200 mg·m-3,the sulfur content in the sintering mixture need reduce to below 0.013%,but it is very difficult to realize under the current material condition.

  2. Sulfur Earth

    Science.gov (United States)

    de Jong, B. H.

    2007-12-01

    Variations in surface tension affect the buoyancy of objects floating in a liquid. Thus an object floating in water will sink deeper in the presence of dishwater fluid. This is a very minor but measurable effect. It causes for instance ducks to drown in aqueous solutions with added surfactant. The surface tension of liquid iron is very strongly affected by the presence of sulfur which acts as a surfactant in this system varying between 1.9 and 0.4 N/m at 10 mass percent Sulfur (Lee & Morita (2002), This last value is inferred to be the maximum value for Sulfur inferred to be present in the liquid outer core. Venting of Sulfur from the liquid core manifests itself on the Earth surface by the 105 to 106 ton of sulfur vented into the atmosphere annually (Wedepohl, 1984). Inspection of surface Sulfur emission indicates that venting is non-homogeneously distributed over the Earth's surface. The implication of such large variation in surface tension in the liquid outer core are that at locally low Sulfur concentration, the liquid outer core does not wet the predominantly MgSiO3 matrix with which it is in contact. However at a local high in Sulfur, the liquid outer core wets this matrix which in the fluid state has a surface tension of 0.4 N/m (Bansal & Doremus, 1986), couples with it, and causes it to sink. This differential and diapiric movement is transmitted through the essentially brittle mantle (1024 Pa.s, Lambeck & Johnson, 1998; the maximum value for ice being about 1030 Pa.s at 0 K, in all likely hood representing an upper bound of viscosity for all materials) and manifests itself on the surface by the roughly 20 km differentiation, about 0.1 % of the total mantle thickness, between topographical heights and lows with concomitant lateral movement in the crust and upper mantle resulting in thin skin tectonics. The brittle nature of the medium though which this movement is transmitted suggests that the extremes in topography of the D" layer are similar in range to

  3. Sequence-controlled methacrylic multiblock copolymers via sulfur-free RAFT emulsion polymerization

    Science.gov (United States)

    Engelis, Nikolaos G.; Anastasaki, Athina; Nurumbetov, Gabit; Truong, Nghia P.; Nikolaou, Vasiliki; Shegiwal, Ataulla; Whittaker, Michael R.; Davis, Thomas P.; Haddleton, David M.

    2017-02-01

    Translating the precise monomer sequence control achieved in nature over macromolecular structure (for example, DNA) to whole synthetic systems has been limited due to the lack of efficient synthetic methodologies. So far, chemists have only been able to synthesize monomer sequence-controlled macromolecules by means of complex, time-consuming and iterative chemical strategies such as solid-state Merrifield-type approaches or molecularly dissolved solution-phase systems. Here, we report a rapid and quantitative synthesis of sequence-controlled multiblock polymers in discrete stable nanoscale compartments via an emulsion polymerization approach in which a vinyl-terminated macromolecule is used as an efficient chain-transfer agent. This approach is environmentally friendly, fully translatable to industry and thus represents a significant advance in the development of complex macromolecule synthesis, where a high level of molecular precision or monomer sequence control confers potential for molecular targeting, recognition and biocatalysis, as well as molecular information storage.

  4. Performance of a monolith biotrickling filter treating high concentrations of H2S from mimic biogas and elemental sulfur plugging control using pigging.

    Science.gov (United States)

    Qiu, Xintong; Deshusses, Marc A

    2017-08-08

    A novel biotrickling filter using a 3D-printed honeycomb-monolith as its filter bed has been proposed and studied in this work and a solution to bed-clogging problems using pigging was demonstrated. The inlet H2S concentration in the mimic biogas was controlled around 1000 ppmv and the empty bed gas residence time (EBRT) was 41 s corresponding to a loading rate of 127 g S-H2S m(-3) h(-1). The influence of different H2S/O2 ratios on the removal performance and fate of sulfur end-products was investigated. The results indicated that at a H2S/O2 molar ratio of 1:2, an average removal efficiency of 95% and an elimination capacity of 122 g H2S m(-3) h(-1) was obtained. Under all conditions investigated, elemental sulfur (rather than sulfate) was the dominant end-product which mostly accumulated in the bed. However, the monolith bed design reduced the risk of clogging by elemental sulfur, while bed pigging was shown to be an effective means to remove excess biomass and elemental sulfur accumulated inside the bed and extend the life of the system indefinitely. Altogether, these findings could lead to significant process improvement for biological sweetening of biogas or for removing biomass in biotrickling filters at risk of plugging. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Chain-branching control of the atomic structure of alkanethiol-based gold-sulfur interfaces.

    Science.gov (United States)

    Wang, Yun; Chi, Qijin; Zhang, Jingdong; Hush, Noel S; Reimers, Jeffrey R; Ulstrup, Jens

    2011-09-28

    Density functional theory structure calculations at 0 K and simulations at 300 K of observed high-resolution in situ scanning tunneling microscopy (STM) images reveal three different atomic-interface structures for the self-assembled monolayers (SAMs) of three isomeric butanethiols on Au(111): direct binding to the Au(111) surface without pitting, binding to adatoms above a regular surface with extensive pitting, and binding to adatoms with local surface vacancies and some pitting. Thermal motions are shown to produce some observed STM features, with a very tight energy balance controlling the observed structures. Variation of the degree of substitution on the α carbon is found to significantly change the relative energies for interaction of the different types of adatom structures with the surface, while the nature of the surface cell, controlled primarily by inter-adsorbate steric interactions, controls substrate reorganization energies and adsorbate distortion energies. Most significantly, by manipulating these features, chemical control of the adsorbate can produce stable interfaces with surface pitting eliminated, providing new perspectives for technological applications of SAMs.

  6. Sulfur acidic mining lakes in Germany: ways of controlling geogenic acidification

    Energy Technology Data Exchange (ETDEWEB)

    Klapper, H.; Schultze, M. [UFZ GmbH Centre for Environmental Research Leipzig-Halle, Magdeburg (Germany). Section of Inland Water Research

    1997-12-31

    The main cause of the sulphurous acidity found in about 100 mining lakes in eastern Germany is oxidation of pyrite from surface lignite mining. Methods for neutralization of these lakes into well functioning ecosystems are described, in particular, water pollution abatement and the related problems of salinization, contamination, eutrophication, saprobization, and infection. The chemical characteristics and life conditions of the acidic environment and acidification control are discussed. Several ways to foster alkalinity production by microbial processes are outlined. 25 refs., 6 figs., 1 tab.

  7. Biologically produced sulfur

    NARCIS (Netherlands)

    Kleinjan, W.E.; Keizer, de A.; Janssen, A.J.H.

    2003-01-01

    Sulfur compound oxidizing bacteria produce sulfur as an intermediate in the oxidation of hydrogen sulfide to sulfate. Sulfur produced by these microorganisms can be stored in sulfur globules, located either inside or outside the cell. Excreted sulfur globules are colloidal particles which are stabil

  8. Accidents with sulfuric acid

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2006-01-01

    Full Text Available Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eighteen years (from 1988 till the beginning of 2006 are analyzed in this paper. It is very alarming data that, according to all the recorded accidents, over 1.6 million tons of sulfuric acid were exuded. Although water transport is the safest (only 16.38% of the total amount of accidents in that way 98.88% of the total amount of sulfuric acid was exuded into the environment. Human factor was the common factor in all the accidents, whether there was enough control of the production process, of reservoirs or transportation tanks or the transport was done by inadequate (old tanks, or the accidents arose from human factor (inadequate speed, lock of caution etc. The fact is that huge energy, sacrifice and courage were involved in the recovery from accidents where rescue teams and fire brigades showed great courage to prevent real environmental catastrophes and very often they lost their lives during the events. So, the phrase that sulfuric acid is a real "environmental bomb" has become clearer.

  9. [Effects of sulfur plus resin-coated controlled release urea fertilizer on winter wheat dry matter accumulation and allocation and grain yield].

    Science.gov (United States)

    Man, Jian-Guo; Zhou, Jie; Wang, Dong; Yu, Zhen-Wen; Zhang, Min; Hu, Zhi-Ying; Hou, Xiu-Tao

    2011-05-01

    A field experiment was conducted to study the effects of sulfur plus resin-coated urea fertilizer on the winter wheat dry matter accumulation and allocation and grain yield. Four treatments were installed, i.e., sulfur plus resin-coated urea (SRCU), resin-coated urea (RCU), sulfur-amended conventional urea (SU), and conventional urea (U). The coated urea fertilizers were applied as basal, and the conventional urea fertilizers were 50% applied as basal and 50% applied as topdressing. There were no significant differences in the plant dry matter accumulation and grain yield between treatments RCU and U. Under the conditions the available S content in 0-20 cm soil layer was 43.2 mg x kg(-1) and the S application rate was 91.4 kg x hm(-2), treatments SRCU and SU had no significant differences in the dry matter accumulation and allocation after anthesis and the grain yield, but the amount of the assimilates after anthesis allocated in grain, the grain-filling rate at mid grain-filling stage, the 1000-grain weight, and the grain yield in the two treatments were significantly higher than those in treatment RCU. When the available S content in 0-20 cm soil layer was 105.1 mg x kg(-1) and the S application rate was 120 kg x hm(-2), the grain yield in treatment SRCU was significantly higher than that in treatment SU, but had no significant difference with that in treatments RCU and U. These results suggested that from the viewpoints of dry matter accumulation and allocation and grain yield, the nitrogen released from SRCU had the same regulation effect as the conventional urea 50% applied as basal and 50% applied as topdressing, while the regulation effect of the sulfur released from SRCU was controlled by the available S content in 0-20 cm soil layer. When the soil available S content was 43.2 mg x kg(-1), the released sulfur could promote the dry matter accumulation after anthesis and the grain-filling, and increase the grain yield significantly; when the soil available S

  10. Simultaneous heterotrophic and sulfur-oxidizing autotrophic denitrification process for drinking water treatment: control of sulfate production.

    Science.gov (United States)

    Sahinkaya, Erkan; Dursun, Nesrin; Kilic, Adem; Demirel, Sevgi; Uyanik, Sinan; Cinar, Ozer

    2011-12-15

    A long-term performance of a packed-bed bioreactor containing sulfur and limestone was evaluated for the denitrification of drinking water. Autotrophic denitrification rate was limited by the slow dissolution rate of sulfur and limestone. Dissolution of limestone for alkalinity supplementation increased hardness due to release of Ca(2+). Sulfate production is the main disadvantage of the sulfur autotrophic denitrification process. The effluent sulfate concentration was reduced to values below drinking water guidelines by stimulating the simultaneous heterotrophic and autotrophic denitrification with methanol supplementation. Complete removal of 75 mg/L NO(3)-N with effluent sulfate concentration of around 225 mg/L was achieved when methanol was supplemented at methanol/NO(3)-N ratio of 1.67 (mg/mg), which was much lower than the theoretical value of 2.47 for heterotrophic denitrification. Batch studies showed that sulfur-based autotrophic NO(2)-N reduction rate was around three times lower than the reduction rate of NO(3)-N, which led to NO(2)-N accumulation at high loadings.

  11. Process for the regeneration of an additive used to control emissions during the combustion of high sulfur fuel

    Energy Technology Data Exchange (ETDEWEB)

    Polanco, D.R.; Bueno, C.O.; Salazar, R.; Chamorra, F.A.S

    1989-05-23

    A process is described for regenerating a sulfur capturing additive used in the preparation of a hydrocarbon in water emulsion for combustion as a fuel comprising: (a) forming a hydrocarbon in water emulsion by admixing a sulfur containing hydrocarbon and water with an emulsifier and a water soluble sulfur capturing additive wherein the sulfur capturing additive is selected from the group consisting of Na/sup +/, K/sup +/, Li/sup +/, Ca/sup ++/, Ba/sup ++/, Mg/sup ++/, Fe/sup +++/ and mixtures thereof; (b) burning the emulsion so as to form a combustion ash containing the water soluble additive as a sulfate compound; (c) leaching the combustion ash wherein the combustion ash is leached with water in a water to ash ratio in ml to grams of 1:1 to 30:1 so as to dissolve the water soluble additive sulfate compound to form a pregnant leach liquor containing the additive; (d) separating the pregnant leach liquor containing the additive; (e) adjusting the pregnant leach liquor with a basic precipitating agent wherein the base precipitating agent is selected from the group consisting of NH/sub 4/OH, NaOH, Ca(OH)/sub 2/, NaCO/sub 3/ and mixtures thereof wherein the pregnant leach liquor is adjusted with the base to a pH of greater than 7 so as to precipitate an additive compound; and (f) recovering the additive compound.

  12. Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO sub x ) emissions from high-sulfur coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    1991-08-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NOx) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NOx to convert it to nitrogen and water vapor, Although SCR is widely practiced in Japan and Europe, there are numerous technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuel performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}. (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur US coal.

  13. Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO[sub x]) emissions from high-sulfur coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    1992-08-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO[sub x]) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO[sub x] to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe, there are numerous technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuels. (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO[sub 2] and SO[sub 3]. (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur U. S. coal.

  14. Sulfur metabolism in phototrophic sulfur bacteria

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Dahl, Christiane

    2008-01-01

    Phototrophic sulfur bacteria are characterized by oxidizing various inorganic sulfur compounds for use as electron donors in carbon dioxide fixation during anoxygenic photosynthetic growth. These bacteria are divided into the purple sulfur bacteria (PSB) and the green sulfur bacteria (GSB......). They utilize various combinations of sulfide, elemental sulfur, and thiosulfate and sometimes also ferrous iron and hydrogen as electron donors. This review focuses on the dissimilatory and assimilatory metabolism of inorganic sulfur compounds in these bacteria and also briefly discusses these metabolisms...... in other types of anoxygenic phototrophic bacteria. The biochemistry and genetics of sulfur compound oxidation in PSB and GSB are described in detail. A variety of enzymes catalyzing sulfur oxidation reactions have been isolated from GSB and PSB (especially Allochromatium vinosum, a representative...

  15. Elucidating microbial processes in nitrate- and sulfate-reducing systems using sulfur and oxygen isotope ratios: The example of oil reservoir souring control

    Science.gov (United States)

    Hubert, Casey; Voordouw, Gerrit; Mayer, Bernhard

    2009-07-01

    Sulfate-reducing bacteria (SRB) are ubiquitous in anoxic environments where they couple the oxidation of organic compounds to the production of hydrogen sulfide. This can be problematic for various industries including oil production where reservoir "souring" (the generation of H 2S) requires corrective actions. Nitrate or nitrite injection into sour oil fields can promote SRB control by stimulating organotrophic nitrate- or nitrite-reducing bacteria (O-NRB) that out-compete SRB for electron donors (biocompetitive exclusion), and/or by lithotrophic nitrate- or nitrite-reducing sulfide oxidizing bacteria (NR-SOB) that remove H 2S directly. Sulfur and oxygen isotope ratios of sulfide and sulfate were monitored in batch cultures and sulfidic bioreactors to evaluate mitigation of SRB activities by nitrate or nitrite injection. Sulfate reduction in batch cultures of Desulfovibrio sp. strain Lac15 indicated typical Rayleigh-type fractionation of sulfur isotopes during bacterial sulfate reduction (BSR) with lactate, whereas oxygen isotope ratios in unreacted sulfate remained constant. Sulfur isotope fractionation in batch cultures of the NR-SOB Thiomicrospira sp. strain CVO was minimal during the oxidation of sulfide to sulfate, which had δ18O SO4 values similar to that of the water-oxygen. Treating an up-flow bioreactor with increasing doses of nitrate to eliminate sulfide resulted in changes in sulfur isotope ratios of sulfate and sulfide but very little variation in oxygen isotope ratios of sulfate. These observations were similar to results obtained from SRB-only, but different from those of NR-SOB-only pure culture control experiments. This suggests that biocompetitive exclusion of SRB took place in the nitrate-injected bioreactor. In two replicate bioreactors treated with nitrite, less pronounced sulfur isotope fractionation and a slight decrease in δ18O SO4 were observed. This indicated that NR-SOB played a minor role during dosing with low nitrite and that

  16. Advanced sulfur control concepts in hot-gas desulfurization technology: Phase 2. Exploratory studies on the direct production of elemental sulfur during the regeneration of high temperature desulfurization sorbents. Topical report

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, A.; Huang, W.; White, J. [and others

    1997-07-01

    The topical report describes the results of Phase 2 research to determine the feasibility of the direct production of elemental sulfur during the regeneration of high temperature desulfurization sorbents. Many of the contaminants present in coal emerge from the gasification process in the product gas. Much effort has gone into the development of high temperature metal oxide sorbents for removal of H{sub 2}S from coal gas. The oxides of zinc, iron, manganese, and others have been studied. In order for high temperature desulfurization to be economical it is necessary that the sorbents be regenerated to permit multicycle operation. Current methods of sorbent regeneration involve oxidation of the metal sulfide to reform the metal oxide and free the sulfur as SO{sub 2}. An alternate regeneration process in which the sulfur is liberated in elemental form is desired. Elemental sulfur, which is the typical feed to sulfuric acid plants, may be easily separated, stored, and transported. Although research to convert SO{sub 2} produced during sorbent regeneration to elemental sulfur is on-going, additional processing steps are required and the overall process will be more complex. Clearly, the direct production of elemental sulfur is preferred. Desulfurization utilizing a cerium oxide based sorbent is discussed.

  17. Demonstration of SCR technology for the control of NOx emissions from high-sulfur coal-fired utility boilers

    Energy Technology Data Exchange (ETDEWEB)

    Hinton, W.S. [W.S. Hinton and Associates, Cantonment, FL (United States); Maxwell, J.D.; Healy, E.C.; Hardman, R.R. [Southern Company Services, Inc., Birmingham, AL (United States); Baldwin, A.L. [Dept. of Energy, Pittsburgh, PA (United States)

    1997-12-31

    This paper describes the completed Innovative Clean Coal Technology project which demonstrated SCR technology for reduction of flue gas NO{sub x} emissions from a utility boiler burning US high-sulfur coal. The project was sponsored by the US Department of Energy, managed and co-funded by Southern Company Services, Inc. on behalf of the Southern Company, and also co-funded by the Electric Power Research Institute and Ontario Hydro. The project was located at Gulf Power Company`s Plant Crist Unit 5 (a 75 MW tangentially-fired boiler burning US coals that had a sulfur content ranging from 2.5--2.9%), near Pensacola, Florida. The test program was conducted for approximately two years to evaluate catalyst deactivation and other SCR operational effects. The SCR test facility had nine reactors: three 2.5 MW (5,000 scfm), and operated on low-dust flue gas. The reactors operated in parallel with commercially available SCR catalysts obtained from suppliers throughout the world. Long-term performance testing began in July 1993 and was completed in July 1995. A brief test facility description and the results of the project are presented in this paper.

  18. Thiophenic Sulfur Compounds Released During Coal Pyrolysis

    Science.gov (United States)

    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

  19. Solubility of Sulfur Dioxide in Sulfuric Acid

    Science.gov (United States)

    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.

  20. Significant interaction effects from sulfate deposition and climate on sulfur concentrations constitute major controls on methylmercury production in peatlands

    Science.gov (United States)

    Åkerblom, Staffan; Bishop, Kevin; Björn, Erik; Lambertsson, Lars; Eriksson, Tobias; Nilsson, Mats B.

    2013-02-01

    Transformation of inorganic mercury (Hg) to methyl mercury (MeHg) in peatlands is a key process in making boreal catchments a source of MeHg to freshwater ecosystems. Due to the importance of sulfur-reducing bacteria (SRB) for this process, past atmospheric deposition of sulfate (SO42-) may have increased net terrestrial Hg methylation. A long-term (14-year) factorial design field experiment was used to investigate the effect of enhanced SO42- deposition and raised temperature using a greenhouse (GH) treatment (air temperature˜+4 °C; soil temperature 20 cm below mire surface ˜+2 °C) on sulfur (S) turnover, net Hg methylation, MeHg and total Hg concentrations in a boreal mire in northern Sweden. Of the SO42--S added during 14 years, 50% was retained in the plots without GH treatment while the combination of SO42- addition and GH treatment resulted in 15% S retention. The addition of SO42- (7-fold ambient SO42--deposition) increased (p important than the concentration of Hg for the production of MeHg in this boreal landscape. These results also show that long-term chronic SO42- deposition at rates similar to those found in polluted areas of Europe and North America increase the capacity of wetlands to methylate Hg and store MeHg, which can ultimately be released to streams and lakes. This study also, for the first time, indicates that the enhancing effect of SO42- on the production of MeHg might be counteracted by increased temperature.

  1. Effect of sulfur content in a sulfur-activated carbon composite on the electrochemical properties of a lithium/sulfur battery

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin-Woo; Kim, Changhyeon; Ryu, Ho-Suk; Cho, Gyu-Bong; Cho, Kwon-Koo; Kim, Ki-Won [School of Materials Science and Engineering, Gyeongsang National University, Jinju (Korea, Republic of); Ahn, Jou-Hyeon [Department of Chemical & Biological Engineering, Gyeongsang National University, Jinju (Korea, Republic of); Wang, Guoxiu [School of Chemistry and Forensic Science, University of Technology Sydney, Sydney, NSW 2007 (Australia); Ahn, Jae-Pyeung [Advanced Analysis Center, Research Planning & Coordination Division, KIST, Seoul (Korea, Republic of); Ahn, Hyo-Jun, E-mail: ahj@gnu.ac.kr [School of Materials Science and Engineering, Gyeongsang National University, Jinju (Korea, Republic of)

    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)

  2. Sulfur Mustard

    Science.gov (United States)

    ... Specific Hazards Bioterrorism A-Z Anthrax (Bacillus anthracis) Arenaviruses Treatment & Infection Control Specimen Submission & Lab Testing Education & ... hemorrhagic fevers (filoviruses [e.g., Ebola, Marburg] and arenaviruses [e.g., Lassa, Machupo]) Yersinia pestis (plague) Fact ...

  3. Formation and Control of Sulfur Oxides in Sour Gas Oxy-Combustion: Prediction Using a Reactor Network Model

    KAUST Repository

    Bongartz, Dominik

    2015-11-19

    © 2015 American Chemical Society. Sour natural gas currently requires expensive gas cleanup before it can be used in power generation because it contains large amounts of hydrogen sulfide (H2S) and carbon dioxide (CO2) that entail a low heating value and highly corrosive combustion products. A potential alternative is to use the gas directly in a gas turbine process employing oxy-fuel combustion, which could eliminate the need for gas cleanup while also enabling the application of carbon capture and sequestration, possibly combined with enhanced oil recovery (EOR). However, the exact influence of an oxy-fuel environment on the combustion products of sour gas has not been quantified yet. In this work, we used a reactor network model for the combustor and the gas turbine together with our recently assembled and validated detailed chemical reaction mechanism for sour gas combustion to investigate the influence of some basic design parameters on the combustion products of natural gas and sour gas in CO2 or H2O diluted oxy-fuel combustion as well as in conventional air combustion. Our calculations show that oxy-fuel combustion produces up to 2 orders of magnitude less of the highly corrosive product sulfur trioxide (SO3) than air combustion, which clearly demonstrates its potential in handling sulfur containing fuels. Unlike in air combustion, in oxy-fuel combustion, SO3 is mainly formed in the flame zone of the combustor and is then consumed as the combustion products are cooled in the dilution zone of the combustor and the turbine. In oxy-fuel combustion, H2O dilution leads to a higher combustion efficiency than CO2 dilution. However, if the process is to be combined with EOR, CO2 dilution makes it easier to comply with the very low levels of oxygen (O2) required in the EOR stream. Our calculations also show that it might even be beneficial to operate slightly fuel-rich because this simultaneously decreases the O2 and SO3 concentration further. The flame zone

  4. Sulfuric acid on Europa and the radiolytic sulfur cycle

    Science.gov (United States)

    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.

  5. Efficacy of omeprazole on cough, pulmonary function and quality of life of patients with sulfur mustard lung injury: A placebo-control, cross-over clinical trial study

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Emami

    2014-01-01

    Full Text Available Background: Gastro-esophageal reflux disease (GERD is prevalent and related to more severe disease in patients with respiratory problems. We evaluated the effects of antireflux therapy in warfare victims of exposure to Mustard gas with chronic cough. Materials and Methods: This randomized, double-blind, placebo-controlled, cross-over study was conducted on 45 cases of sulfur mustard injury with chronic cough (≥8 weeks and GERD. Patients were randomized into two groups, receiving either 20 mg twice daily omeprazole-placebo (OP or matching placebo (placebo-omeprazole [PO] for 4 months, followed by a 1-month washout period and the alternative treatment for 4 months. Assessments included GERD and cough, quality of life, and pulmonary function using spirometry. Leicester Cough Questionnaire and SF-36 were used for measuring quality of life. Results: Patients in the OP group experienced a more decrease than those in the PO group in severity of Leicester cough scores during the first 4-month of trial. After crossing the groups, the OP group experienced an increase (P = 0.036 and the PO group experienced a nonsignificant decrease (P = 0.104 in the severity of scores. The OP group also experienced improvement in GERD symptoms and quality of life at the end of the trial, but changes in the PO group was not significant. There was no significant change in respiratory function indices in any groups. Conclusion: Long-term treatment with high-dose omeprazole improved GERD as well as cough, and quality of life, but not changed respiratory function indices in sulfur mustard injured cases with respiratory symptoms.

  6. To control and to be controlled – understanding the Arabidopsis SLIM1 function in sulfur deficiency through comprehensive investigation of the EIL protein family.

    OpenAIRE

    Anna eWawrzyńska; Agnieszka eSirko

    2014-01-01

    SSLIM1, a member of the EIN3-like (EIL) family of transcription factors in Arabidopsis, is the regulator of many sulfur-deficiency responsive genes. Among the five other proteins of the family, three regulate ethylene responses and two have unassigned functions. Contrary to the well-defined ethylene signaling, the pathway leading from sensing sulfate status to the activation of its acquisition via SLIM1 is completely unknown. SLIM1 binds to the 20 nt-long specific UPE-box sequence; however, i...

  7. Resíduos de calda sulfocálcica sobre a eficiência de acaricidas no controle de Brevipalpus phoenicis Lime sulfur residue on acaricide efficiency in the control of Brevipalpus phoenicis

    Directory of Open Access Journals (Sweden)

    Daniel Junior de Andrade

    2011-10-01

    Full Text Available O objetivo do trabalho foi verificar a influência dos resíduos de calda sulfocálcica sobre a eficiência de acaricidas empregados no controle de Brevipalpus phoenicis. Inicialmente, o experimento foi instalado em um pomar de citros, em que foram selecionadas 10 plantas que continham frutos com verrugose. Realizou-se a aplicação de calda sulfocálcica (8g i.a. L-1 de água em cinco plantas e as outras cinco plantas permaneceram sem aplicação de produto fitossanitário. Protegeram-se, com copos de plástico transparente de 500mL, 64 frutos nas plantas tratadas com calda e 64 frutos nas plantas não-tratadas, totalizando 128 frutos protegidos. Decorridos 30 dias da aplicação, os frutos foram colhidos e levados para o laboratório. Estes frutos foram parcialmente parafinados, deixando-se em cada fruto uma arena de 2,5cm de diâmetro com verrugose e sem parafina, delimitada com cola entomológica. Em seguida, procedeu-se à aplicação sobre os frutos em Torre de Potter dos seguintes acaricidas nas concentrações expressas em mg de ingrediente ativo por litro de água: propargite a 720mg, óxido de fenbutatina a 400mg, cyhexatin a 250mg, azocyclotin a 250mg, fenpyroximate a 50mg, dicofol a 960mg e dinocap a 738mg e a testemunha sem aplicação de acaricida. Após 1, 7 e 16 dias da aplicação, transferiram-se para cada fruto 10 ácaros B. phoenicis para avaliar a mortalidade. Constatou-se que os resíduos de calda sulfocálcica não prejudicaram a eficiência dos acaricidas avaliados no controle de B. phoenicis.The objective was to assess the influence of lime sulfur residues on the acaricidal efficiency against Brevipalpus phoenicis mite. Initially, the experiment was conducted in a citrus orchard where 10 plants presenting scab fruits were selected. Secondly, the application of lime sulfur (8mg a.i. L-1 of water was performed in five plants, and the other five plants remained without application. Next lime sulfur application, 64 fruits in

  8. Sulfur recovery further improved

    Energy Technology Data Exchange (ETDEWEB)

    Borsboom, J.; Grinsven, M. van; Warners, A. van [Jacobs Nederland B.V., (Netherlands); Nisselrooy, P. van [Gastec N.V., (Netherlands)

    2002-04-01

    The original 100-year-old Claus process for producing sulfur from hydrogen sulfide in acid gas is described together with improvements which have been made over the years. The most recent modification, EUROCLAUS, achieves sulfur recoveries of 99-99.9 per cent. Five commercial units are being designed.

  9. National Level Co-Control Study of the Targets for Energy Intensity and Sulfur Dioxide in China

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Nan; Price, Lynn; Zheng, Nina; Ke, Jing; Hasanbeigi, Ali

    2011-10-15

    Since 2006, China has set goals of reducing energy intensity, emissions, and pollutants in multiple guidelines and in the Five Year Plans. Various strategies and measures have then been taken to improve the energy efficiency in all sectors and to reduce pollutants. Since controlling energy, CO{sub 2} emissions, and pollutants falls under the jurisdiction of different government agencies in China, many strategies are being implemented to fulfill only one of these objectives. Co-controls or integrated measures could simultaneously reduce greenhouse gas (GHG) emissions and criteria air pollutant emissions. The targets could be met in a more cost effective manner if the integrated measures can be identified and prioritized. This report provides analysis and insights regarding how these targets could be met via co-control measures focusing on both CO{sub 2} and SO{sub 2} emissions in the cement, iron &steel, and power sectors to 2030 in China. An integrated national energy and emission model was developed in order to establish a baseline scenario that was used to assess the impact of actions already taken by the Chinese government as well as planned and expected actions. In addition, CO{sub 2} mitigation scenarios and SO{sub 2} control scenarios were also established to evaluate the impact of each of the measures and the combined effects. In the power sector, although the end of pipe SO{sub 2} control technology such as flue gas desulfurization (FGD) has the largest reduction potential for SO{sub 2} emissions, other CO{sub 2} control options have important co-benefits in reducing SO{sub 2} emissions of 52.6 Mt of SO{sub 2} accumulatively. Coal efficiency improvements along with hydropower, renewable and nuclear capacity expansion will result in more than half of the SO{sub 2} emission reductions as the SO{sub 2} control technology through 2016. In comparison, the reduction from carbon capture and sequestration (CCS) is much less and has negative SO{sub 2} reductions

  10. Nanostructured sulfur cathodes

    KAUST Repository

    Yang, Yuan

    2013-01-01

    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. © 2013 The Royal Society of Chemistry.

  11. Effects of sulfur bath on hip osteoarthritis: a randomized, controlled, single-blind, follow-up trial: a pilot study

    Science.gov (United States)

    Kovács, Csaba; Bozsik, Ágnes; Pecze, Mariann; Borbély, Ildikó; Fogarasi, Andrea; Kovács, Lajos; Tefner, Ildikó Katalin; Bender, Tamás

    2016-11-01

    The effects of balneotherapy were evaluated in patients with osteoarthritis of the hip. This randomized, controlled, investigator-blinded study enrolled outpatients with hip osteoarthritis according to ACR criteria. In addition to home exercise therapy, one patient group received balneotherapy for 3 weeks on 15 occasions. The mineral water used in this study is one of the mineral waters with the highest sulfide ion content (13.2 mg/L) in Hungary. The control group received exercise therapy alone. The WOMAC Likert 3.1 index and the EQ-5D quality of life self-administered questionnaire were completed three times during the study: prior to first treatment, at the end of the 3-week treatment course, and 12 weeks later. The main endpoint was achievement of Minimal Clinically Important Improvement (MCII) at 12 weeks, defined as ≥7.9 points in a normalized WOMAC function score. The intention to treat analysis included 20 controls and 21 balneotherapy patients. At 12 weeks, 17 (81 %) balneotherapy group patients had Minimal Clinically Important Improvement and 6 (30 %) of controls ( p = 0.001). Comparing the results of the two groups at the end of treatment, there was a significant difference in the WOMAC stiffness score only, whereas after 12 weeks, the WOMAC pain, stiffness, function, and total scores also showed a significant difference in favor of the balneotherapy group. The difference between the two groups was significant after 12 weeks in point of EQVAS score, too. The results of our study suggest that the combination of balneotherapy and exercise therapy achieves more sustained improvement of joint function and decreases in pain than exercise therapy alone.

  12. Kinetics and Mechanisms of Chalcopyrite Dissolution at Controlled Redox Potential of 750 mV in Sulfuric Acid Solution

    Directory of Open Access Journals (Sweden)

    Yubiao Li

    2016-08-01

    Full Text Available To better understand chalcopyrite leach mechanisms and kinetics, for improved Cu extraction during hydrometallurgical processing, chalcopyrite leaching has been conducted at solution redox potential 750 mV, 35–75 °C, and pH 1.0 with and without aqueous iron addition, and pH 1.5 and 2.0 without aqueous iron addition. The activation energy (Ea values derived indicate chalcopyrite dissolution is initially surface chemical reaction controlled, which is associated with the activities of Fe3+ and H+ with reaction orders of 0.12 and −0.28, respectively. A surface diffusion controlled mechanism is proposed for the later leaching stage with correspondingly low Ea values. Surface analyses indicate surface products (predominantly Sn2− and S0 did not inhibit chalcopyrite dissolution, consistent with the increased surface area normalised leach rate during the later stage. The addition of aqueous iron plays an important role in accelerating Cu leaching rates, especially at lower temperature, primarily by reducing the length of time of the initial surface chemical reaction controlled stage.

  13. Childhood physical abnormalities following paternal exposure to sulfur mustard gas in Iran: a case-control study

    Directory of Open Access Journals (Sweden)

    Khademolhosseini Seyyed M

    2010-07-01

    Full Text Available Abstract Background Mustard gas, a known chemical weapon, was used during the Iran-Iraq war of 1980-1988. We aimed to determine if exposure to mustard gas among men was significantly associated with abnormalities and disorders among progenies. Methods Using a case-control design, we identified all progenies of Sardasht men (exposed group, n = 498, who were born at least nine months after the exposure, compared to age-matched controls in Rabat, a nearby city (non-exposed group, n = 689. We conducted a thorough medical history, physical examination, and appropriate paraclinical studies to detect any physical abnormality and/or disorder. Given the presence of correlated data, we applied Generalized Estimating Equation (GEE multivariable models to determine associations. Results The overall frequency of detected physical abnormalities and disorders was significantly higher in the exposed group (19% vs. 11%, Odds Ratio [OR] 1.93, 95% Confidence Interval [CI], 1.37-2.72, P = 0.0002. This was consistent across sexes. Congenital anomalies (OR 3.54, 95% CI, 1.58-7.93, P = 0.002 and asthma (OR, 3.12, 95% CI, 1.43-6.80, P = 0.004 were most commonly associated with exposure. No single abnormality was associated with paternal exposure to mustard gas. Conclusion Our study demonstrates a generational effect of exposure to mustard gas. The lasting effects of mustard gas exposure in parents effects fertility and may impact child health and development in the long-term.

  14. Sulfuric Acid on Europa

    Science.gov (United States)

    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. Cytoplasmic sulfur trafficking in sulfur-oxidizing prokaryotes.

    Science.gov (United States)

    Dahl, Christiane

    2015-04-01

    Persulfide groups are chemically versatile and participate in a wide array of biochemical pathways. Although it is well documented that persulfurated proteins supply a number of important and elaborate biosynthetic pathways with sulfane sulfur, it is far less acknowledged that the enzymatic generation of persulfidic sulfur, the successive transfer of sulfur as a persulfide between multiple proteins, and the oxidation of sulfane sulfur in protein-bound form are also essential steps during dissimilatory sulfur oxidation in bacteria and archaea. Here, the currently available information on sulfur trafficking in sulfur oxidizing prokaryotes is reviewed, and the idea is discussed that sulfur is always presented to cytoplasmic oxidizing enzymes in a protein-bound form, thus preventing the occurrence of free sulfide inside of the prokaryotic cell. Thus, sulfur trafficking emerges as a central element in sulfur-oxidizing pathways, and TusA homologous proteins appear to be central and common elements in these processes.

  16. A Discuss of Sulfur Dioxide Emission Control of China's Oil and Gas Industry%石油天然气行业SO2总量控制思考

    Institute of Scientific and Technical Information of China (English)

    范巍; 李兴春; 龙飞

    2011-01-01

    指出了石油天然气行业是国家在“十二五”期间SO2减排的重点控制行业,调查了我国石油天然气的生产和消费情况,以“十一五”前3年为基础,对行业“十二五”SO2排放进行了预测。分析了行业SO2减排的技术经济可行性,提出了行业SO2减排的主要控制途径和新增总量的控制措施。%Oil and gas industry is the key industry of sulfur dioxide emission control during the "Twelve five --year" period of China. This paperinvestigates the situation of China's oil and gas production and consumption and predicts the sulfur dioxide emissions during the "Twelve five-year" period based on the first three years of the "Eleventh Five Year" period. Besides, it also analyses the technical and economic feasibility of the controlling of sulfur dioxide emissions in oil and gas industry and puts forward the main control means.

  17. Characteristics and recent trends of sulfur dioxide at urban, rural, and background sites in North China: Effectiveness of control measures

    Institute of Scientific and Technical Information of China (English)

    Weili Lin; Xiaobin Xu; Zhiqiang Ma; Huarong Zhao; Xiwen Liu; Ying Wang

    2012-01-01

    SO2 measurements made in recent years at sites in Beijing and its surrounding areas are performed to study the variations and trends of surface SO2 at different types of sites in Northern China.The overall average concentrations of SO2 are (16.8 ± 13.1) ppb,(14.8 ±9.4) ppb,and (7.5 ± 4.0) ppb at China Meteorological Administration (CMA,Beijing urban area),Gucheng (GCH,relatively polluted rural area,110 km to the southwest of Beijing urban area),and Shangdianzi (SDZ,clean background area,100 km to the northeast of Beijing urban area),respectively.The SO2 levels in winter (heating season) are 4-6 folds higher than those in summer.There are highly significant correlations among the daily means of SO2 at different sites,indicating regional characteristics of SO2 pollution.Diurnal patterns of surface SO2 at all sites have a common feature with a daytime peak,which is probably caused by the downward mixing and/or the advection transport of SO2-richer air over the North China Plain.The concentrations of SO2 at CMA and GCH show highly significant downward trends (-4.4 ppb/yr for CMA and -2.4 ppb/yr for GCH),while a less significant trend (-0.3 ppb/yr) is identified in the data from SDZ,reflecting the character of SDZ as a regional atmospheric background site in North China.The SO2 concentrations of all three sites show a significant decrease from period before to after the control measures for the 2008 Olympic Games,suggesting that the SO2 pollution control has long-term effectiveness and benefits.In the post-Olympics period,the mean concentrations of SO2 at CMA,GCH,and SDZ are (14.3 ± 11.0) ppb,(12.1 ± 7.7) ppb,and (7.5 ± 4.0) ppb,respectively,with reductions of 26%,36%,and 13%,respectively,compared to the levels before.Detailed analysis shows that the differences of temperature,relative humidity,wind speed,and wind direction were not the dominant factors for the significant differences of SO2 between the pre-Olympics and post-Olympics periods.By extracting the data

  18. Biosynthesis and functions of sulfur modifications in tRNA

    Directory of Open Access Journals (Sweden)

    Naoki eShigi

    2014-04-01

    Full Text Available Sulfur is an essential element for a variety of cellular constituents in all living organisms. In tRNA molecules, there are many sulfur-containing nucleosides, such as the derivatives of 2‑thiouridine (s2U, 4-thiouridine (s4U, 2-thiocytidine (s2C, and 2-methylthioadenosine (ms2A. Earlier studies established the functions of these modifications for accurate and efficient translation, including proper recognition of the codons in mRNA or stabilization of tRNA structure. In many cases, the biosynthesis of these sulfur modifications starts with cysteine desulfurases, which catalyze the generation of persulfide (an activated form of sulfur from cysteine. Many sulfur-carrier proteins are responsible for delivering this activated sulfur to each biosynthesis pathway. Finally, specific modification enzymes activate target tRNAs and then incorporate sulfur atoms. Intriguingly, the biosynthesis of 2-thiouridine in all domains of life is functionally and evolutionarily related to the ubiquitin-like post-translational modification system of cellular proteins in eukaryotes. This review summarizes the recent characterization of the biosynthesis of sulfur modifications in tRNA and the novel roles of this modification in cellular functions in various model organisms, with a special emphasis on 2-thiouridine derivatives. Each biosynthesis pathway of sulfur-containing molecules is mutually modulated via sulfur trafficking, and 2-thiouridine and codon usage bias have been proposed to control the translation of specific genes.

  19. Genetic relationships between swamp microenvironment and sulfur distribution of the Late Paleozoic coals in North China

    Institute of Scientific and Technical Information of China (English)

    汤达祯; 杨起; 周春光; 康西栋; 刘大锰; 黄文辉

    2001-01-01

    The genetic relationships between microenvironment of the Late Paleozoic peat-forming swamp and the sulfur contents of coal in North China have been studied by using coal-facies parameters involving gelification degree, tissue preservation index, vegetation index, transportation index, groundwater influence index, water medium indicator and swamp type index, etc. Among the various controlling factors of swamp microenvironment, swamp water medium elaborates a dominant action to sulfur accumulation in the marine-influenced coals; while coal-forming plant type, hydrodynamic state and water covering depth are more important to sulfur accumulation in the fresh water-influenced coals. Geological fractionation of sulfur isotopes reflects that sulfur accumulation experienced multi-stages evolution. Pyrite sulfurs formed earlier than organic sulfur and the sulfur isotopic d 34Sp shows lower values than organic sulfur isotopic d 34So. In the brine-influenced coals, sulfur accumulation processed relatively a long time span, the distribution of sulfur isotopes dispersed,and the coals are provided with high sulfur contents. In the fresh-water-influenced coals, sulfur accumulation occurred mainly at the syngenetic-penesyngenetic stage and the early diagenetic stage, and the total sulfur is lower and mainly composed of organic sulfur.

  20. Defects in a New Class of Sulfate/Anion Transporter Link Sulfur Acclimation Responses to Intracellular Glutathione Levels and Cell Cycle Control1[W][OPEN

    Science.gov (United States)

    Fang, Su-Chiung; Chung, Chin-Lin; Chen, Chun-Han; Lopez-Paz, Cristina; Umen, James G.

    2014-01-01

    We previously identified a mutation, suppressor of mating type locus3 15-1 (smt15-1), that partially suppresses the cell cycle defects caused by loss of the retinoblastoma tumor suppressor-related protein encoded by the MAT3 gene in Chlamydomonas reinhardtii. smt15-1 single mutants were also found to have a cell cycle defect leading to a small-cell phenotype. SMT15 belongs to a previously uncharacterized subfamily of putative membrane-localized sulfate/anion transporters that contain a sulfate transporter domain and are found in a widely distributed subset of eukaryotes and bacteria. Although we observed that smt15-1 has a defect in acclimation to sulfur-limited growth conditions, sulfur acclimation (sac) mutants, which are more severely defective for acclimation to sulfur limitation, do not have cell cycle defects and cannot suppress mat3. Moreover, we found that smt15-1, but not sac mutants, overaccumulates glutathione. In wild-type cells, glutathione fluctuated during the cell cycle, with highest levels in mid G1 phase and lower levels during S and M phases, while in smt15-1, glutathione levels remained elevated during S and M. In addition to increased total glutathione levels, smt15-1 cells had an increased reduced-to-oxidized glutathione redox ratio throughout the cell cycle. These data suggest a role for SMT15 in maintaining glutathione homeostasis that impacts the cell cycle and sulfur acclimation responses. PMID:25361960

  1. Innovative clean coal technology (ICCT): Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Fourth quarterly progress report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-12-31

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe, there are numerous technical uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuels; (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}; and (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur US coal.

  2. Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Quarterly report No. 4, April--June 1991

    Energy Technology Data Exchange (ETDEWEB)

    1991-08-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NOx) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NOx to convert it to nitrogen and water vapor, Although SCR is widely practiced in Japan and Europe, there are numerous technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuel performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}. (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur US coal.

  3. Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Quarterly report No. 8, April--June, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-08-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe, there are numerous technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuels. (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}. (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur U. S. coal.

  4. Innovative Clean Coal Technology (ICCT): Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Third quarterly technical progress report 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-11-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe on gas-, oil-, and low-sulfur, coal-fired boilers, there are several technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuels. (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3} and (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small- scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high-sulfur US coal. The demonstration will be performed at Gulf Power Company`s Plant Crist Unit No. 5 (75 MW capacity) near Pensacola, Florida.

  5. Innovative Clean Coal Technology (ICCT): Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Technical progress report, third and fourth quarters 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    The objective of this project is to demonstrate and evaluate commercially available selective catalytic reduction (SCR) catalysts from U.S., Japanese, and European catalyst suppliers on a high-sulfur U.S. Coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to form nitrogen and water vapor. Although SCR is widely practiced in Japan and European gas-, oil-, and low-sulfur coal-fired boilers, there are several technical uncertainties associated with applying SCR to U.S. coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in U.S. coals that are not present in other fuels; (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}; performance of a wide variety of SCR catalyst compositions, geometries, and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties are being explored by operating a series of small- scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur U.S. coal. The demonstration is being performed at Gulf Power Company`s Plant Crist Unit No. 5 (75 MW capacity) near Pensacola, Florida. The project is funded by the U.S. Department of Energy (DOE), Southern Company Services, Inc. (SCS on behalf of the entire Southern electric system), the Electric Power Research Institute (EPRI), and Ontario Hydro. SCS is the participant responsible for managing al aspects of this project. 1 ref., 69 figs., 45 tabs.

  6. Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Technical progress report, first and second quarters 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from U.S., Japanese and European catalyst suppliers on a high-sulfur U.S. coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involve injecting ammonia into the flue gas generated from coal combustion in a boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to form nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe on gas-, oil-, and low-sulfur coal-fired boilers, there are several technical uncertainties associated with applying SCR to U.S. coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in U.S. coals that are not present in other fuels; (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}; and (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties are being explored by operating a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur U.S. coal. The project is being conducted in the following three phases: permitting, environmental monitoring plan and preliminary engineering; detailed design engineering and construction; and operation, testing, disposition and final report. The project was in the operation and testing phase during this reporting period. Accomplishments for this period are described.

  7. Innovative Clean Coal Technology (ICCT): Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Technical progress report, October 1993--December 1993

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from U.S., Japanese and European catalyst suppliers on a high-sulfur U.S. coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe on gas-, oil-, and low-sulfur coal-fired boilers, there are several technical uncertainties associated with applying SCR to U.S. coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in U.S. coals that are not present in other fuels; (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}; and (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties are being explored by operating a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur U.S. coal.

  8. Innovative Clean Coal Technology (ICCT): Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO[sub x]) emissions from high-sulfur coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    1992-11-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO[sub x]) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO[sub x] to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe on gas-, oil-, and low-sulfur, coal-fired boilers, there are several technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuels. (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO[sub 2] and SO[sub 3] and (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small- scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high-sulfur US coal. The demonstration will be performed at Gulf Power Company's Plant Crist Unit No. 5 (75 MW capacity) near Pensacola, Florida.

  9. Innovative Clean Coal Technology (ICCT). Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers: Volume 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from U.S., Japanese and European catalyst suppliers on a high-sulfur U.S. coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO.) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO. to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe on gas-, oil-, and low-sulfur coal- fired boilers, there are several technical uncertainties associated with applying SCR to U.S. coals. These uncertainties include: 1) potential catalyst deactivation due to poisoning by trace metal species present in U.S. coals that are not present in other fuels. 2) performance of the technology and effects on the balance-of- plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}. 3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacturer under typical high-sulfur coal-fired utility operating conditions. These uncertainties were explored by operating nine small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur U.S. coal. In addition, the test facility operating experience provided a basis for an economic study investigating the implementation of SCR technology.

  10. Innovative Clean Coal Technology (ICCT): Demonstration of selective catalytic reduction technology for the control of nitrogen oxide emissions from high-sulfur coal-fired boilers. First and second quarterly technical progress reports, [January--June 1995]. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia (NH{sub 3}) into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor containing a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe on gas-, oil-, and low-sulfur coal-fired boilers, there are several technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuels. (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}. (3) performance of a wide variety of SCR catalyst compositions, geometries, and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties are being explored by operating a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur US coal. The demonstration is being performed at Gulf Power Company`s Plant Crist Unit No. 5 (75 MW nameplate capacity) near Pensacola, Florida. The project is funded by the US Department of Energy (DOE), Southern Company Services, Inc. (SCS on behalf of the entire Southern electric system), the Electric Power Research Institute (EPRI), and Ontario Hydro. SCS is the participant responsible for managing all aspects of this project.

  11. Aircraft exhaust sulfur emissions

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R.C.; Anderson, M.R.; Miake-Lye, R.C.; Kolb, C.E. [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics; Sorokin, A.A.; Buriko, Y.I. [Scientific Research Center `Ecolen`, Moscow (Russian Federation)

    1997-12-31

    The extent to which fuel sulfur is converted to SO{sub 3} during combustion and the subsequent turbine flow in supersonic and subsonic aircraft engines is estimated numerically. The analysis is based on: a flamelet model with non-equilibrium sulfur chemistry for the combustor, and a one-dimensional, two-stream model with finite rate chemical kinetics for the turbine. The results indicate that between 2% and 10% of the fuel sulfur is emitted as SO{sub 3}. It is also shown that, for a high fuel sulfur mass loading, conversion in the turbine is limited by the level of atomic oxygen at the combustor exit, leading to higher SO{sub 2} oxidation efficiency at lower fuel sulfur loadings. While SO{sub 2} and SO{sub 3} are the primary oxidation products, the model results further indicate H{sub 2}SO{sub 4} levels on the order of 0.1 ppm for supersonic expansions through a divergent nozzle. This source of fully oxidized S(6) (SO{sub 3} + H{sub 2}SO{sub 4}) exceeds previously calculated S(6) levels due to oxidation of SO{sub 2} by OH in the exhaust plume outside the engine nozzle. (author) 26 refs.

  12. Corrosion-resistant sulfur concretes

    Science.gov (United States)

    McBee, W. C.; Sullivan, T. A.; Jong, B. W.

    1983-04-01

    Sulfur concretes have been developed by the Bureau of Mines as construction materials with physical and mechanical properties that suit them for use in acid and salt corrosive environments where conventional concretes fail. Mixture design methods were established for preparing sulfur concretes using different types of aggregates and recently developed mixed-modified sulfur cements. Bench-scale testing of the sulfur concretes has shown their potential value. Corrosion resistance, strength, and durability of sulfur concrete are superior to those of conventional materials. Field in situ evaluation tests of the sulfur concretes as replacement for conventional concrete materials are in progress in corrosive areas of 24 commercial chemical, fertilizer, and metallurgical plants.

  13. 46 CFR 151.50-55 - Sulfur (molten).

    Science.gov (United States)

    2010-10-01

    ... depositing of sulfur within the system. (b) Void spaces: (1) Openings to void spaces adjacent to cargo tanks shall be designed and fitted to prevent the entry of water, sulfur or cargo vapors. (2) Connections shall be provided to enable sampling and analyzing vapors in void spaces. (c) Temperature controls shall...

  14. Mass-dependent sulfur isotope fractionation during reoxidative sulfur cycling

    DEFF Research Database (Denmark)

    Pellerin, André; Bui, Thi Hao; Rough, Mikaella

    2015-01-01

    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...... that the two processes cannot be discriminated from each other....

  15. Lunar Sulfur Capture System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Sulfur Capture System (LSCS) is an innovative method to recover sulfur compounds from lunar soil using sorbents derived primarily from in-situ resources....

  16. Lunar Sulfur Capture System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Sulfur Capture System (LSCS) is an innovative method to capture greater than 90 percent of sulfur gases evolved during thermal treatment of lunar soils....

  17. Zeolites Remove Sulfur From Fuels

    Science.gov (United States)

    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.

  18. Innovative clean coal technology (ICCT): Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Quarterly report No. 3, January--March 1991

    Energy Technology Data Exchange (ETDEWEB)

    1991-07-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NOx) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NOx to convert it to nitrogen and water vapor.

  19. Innovative clean coal technology (ICCT): Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO sub x ) emissions from high-sulfur coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    1991-07-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NOx) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NOx to convert it to nitrogen and water vapor.

  20. Innovative Clean Coal Technology (ICCT). Demonstration of Selective Catalytic Reduction (SCR) technology for the control of Nitrogen Oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Technical progress report, third and fourth quarters 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from U.S., Japanese, and European catalyst suppliers on a high-sulfur U.S. coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor.

  1. Innovative Clean Coal Technology (ICCT): Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO sub x ) emissions from high-sulfur coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    1991-02-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide NO{sub x} control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor.

  2. Innovative Clean Coal Technology (ICCT): Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Quarterly report No. 2, October--December 1990

    Energy Technology Data Exchange (ETDEWEB)

    1991-02-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide NO{sub x} control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor.

  3. Structure of amorphous sulfur

    CSIR Research Space (South Africa)

    Eichinger, BE

    2001-06-01

    Full Text Available The lambda-transition of elemental sulfur occurring at about 159°C has long been associated with the conversion of cyclic S8 rings (c-S8) to amorphous polymer (a-S) via a ring opening polymerization. It is demonstrated, with the use of both density...

  4. Oxidation of Elemental Sulfur in Selected Soils of China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An incubation experiment was carried out in laboratory to study the effect of temperature, moisture,phosphorus, organic matter, cropping and previous elemental sulfur application on elemental sulfur oxidation in four selected soils, fluvo-aquic soil, black soil, yellow-brown soil and red soil. In all the soils tested, sulfur oxidation rate was influenced by temperature and the temperature coefficient (Q10) values at the range from 10to 30 ℃ were 4.41, 4.05, 6.19 and 3.71 for the four soils, respectively. The rate of sulfur oxidation was parabolically related to soil water content. The optimum moisture content for the maximum oxidation rate was different among soils. Phosphorus increased the oxidation rate of elemental sulfur by 57.7%, 33.1%, 21.7% and 26.4% for the above four soils, respectively, compared with the control (no phosphorus applied). Organic material of corn straw which was ground and passed through a 0.5-mm sieve also increased the oxidation rate of elemental sulfur in the four soils by 59.8%, 7.8%, 39.2% and 540.4%, respectively. Elemental sulfur which was applied previously to soils significantly enhanced the oxidation of elemental sulfur subsequently added and increased sulfur-oxidizing populations such as autotrophic elemental sulfur oxidizers with pH optimum 6.8, autotrophic thiosulfate oxidizers with pH optimum 6.8, heterotrophic thiosulfate oxidizers and heterotrophic sulfate producers. Cropping had little effect on lemental sulfur-oxidizing potentiality of soils.

  5. Sulfur Dioxide Analyzer Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Springston, Stephen R [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-05-01

    The Sulfur Dioxide Analyzer measures sulfur dioxide based on absorbance of UV light at one wavelength by SO2 molecules which then decay to a lower energy state by emitting UV light at a longer wavelength. Specifically, SO2 + hυ1 →SO2 *→SO2 + hυ2 The emitted light is proportional to the concentration of SO2 in the optical cell. External communication with the analyzer is available through an Ethernet port configured through the instrument network of the AOS systems. The Model 43i-TLE is part of the i-series of Thermo Scientific instruments. The i-series instruments are designed to interface with external computers through the proprietary Thermo Scientific iPort Software. However, this software is somewhat cumbersome and inflexible. Brookhaven National Laboratory (BNL) has written an interface program in National Instruments LabView that both controls the Model 43i-TLE Analyzer AND queries the unit for all measurement and housekeeping data. The LabView vi (the software program written by BNL) ingests all raw data from the instrument and outputs raw data files in a uniform data format similar to other instruments in the AOS and described more fully in Section 6.0 below.

  6. High-resolution quadruple sulfur isotope analyses of 3.2 Ga pyrite from the Barberton Greenstone Belt in South Africa reveal distinct environmental controls on sulfide isotopic arrays

    NARCIS (Netherlands)

    Roerdink, D.L.; Mason, P.R.D.; Whitehouse, M.J.; Reimer, T.

    2013-01-01

    Multiple sulfur isotopes in Paleoarchean pyrite record valuable information on atmospheric processes and emerging microbial activity in the early sulfur cycle. Here, we report quadruple sulfur isotope data (32S, 33S, 34S, 36S) analyzed by secondary ion mass spectrometry from pyrite in a 3.26–3.23 Ga

  7. Influence of sulfur physical properties in Claus unit operation

    Energy Technology Data Exchange (ETDEWEB)

    Larraz Mora, R.; Arvelo Alvarez, R. [Chemical Engineering Dept., Univ. of la Laguna, Tenerife (Spain)

    2002-09-01

    The Claus process is an efficient way of removing H{sub 2}S from acid gas streams and it has been widely practiced in industries such as natural gas processing, oil refining and metal smelting. Increasingly strict pollution control regulations require maximum sulfur recovery and high stream factor from the Claus units in order to minimize sulfur-containing effluents. As has been widely reported Claus unit's damages mainly occur during start up and shutdown. These operations involve scheduled warm-up and cool-down of the unit, usually burning refinery fuel-gas, which if not properly made can produce severe pipe and equipment plugging as well as catalyst deactivation. Sulfur products remaining in the unit during a shutdown period can produce dramatic unit corrosion episodes diminishing sulfur recovery unit stream factor. In the present paper some guidelines are given based on sulfur physical properties singularities which help to improve start-up/shut-down procedures. (orig.)

  8. Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO sub x ) emissions from high-sulfur coal-fired boilers: Innovative Clean Coal Technology (ICCT)

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the amonia reacts with NO{sub x} to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe, there are numerous technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuels. (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO, and SO{sub 3}. (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur US coal. The demonstration will be performed at Gulf Power Company's Plant Crist Unit No. 5 (75 MW capacity) near Pensacola, Florida. The project will be funded by the US Department of Energy (DOE), Southern Company Services, Inc. (SCS on behalf of the entire Southern electric system), and the Electric Power Research Institute.

  9. Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers: Innovative Clean Coal Technology (ICCT). Quarterly report No. 7, January--March 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the amonia reacts with NO{sub x} to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe, there are numerous technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuels. (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO, and SO{sub 3}. (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur US coal. The demonstration will be performed at Gulf Power Company`s Plant Crist Unit No. 5 (75 MW capacity) near Pensacola, Florida. The project will be funded by the US Department of Energy (DOE), Southern Company Services, Inc. (SCS on behalf of the entire Southern electric system), and the Electric Power Research Institute.

  10. Demonstration of selective catalytic reduction technology for the control of nitrogen oxide emissions from high-sulfur, coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Hinton, W.S.; Powell, C.A.; Maxwell, J.D.

    1993-11-01

    This paper describes the status of the Innovative Clean Coal Technology project to demonstrate SCR technology for reduction of NO{sub x} emissions from flue gas of utility boilers burning US high-sulfur coal. The funding participants are the US Department of Energy (DOE), Southern Company Services, Inc. (SCS), on behalf of the entire Southern Company, Electric Power Research Institute (EPRI), and Ontario Hydro. SCS is the participant responsible for managing all aspects of the project. The project is being conducted on Gulf Power Company`s Plant Crist Unit 5 (75-MW nominal capacity), located near Pensacola, Florida, on US coals that have a sulfur content near 3.0%. The SCR facility treats a 17,400 scfm slip-stream of flue gas and consists of three 2.5-MW (5000 scfm) and six 0.2-MW (400 scfm) SCR reactors. The reactors operate in parallel with commercially available SCR catalysts obtained from vendors throughout the world. The design engineering and construction have been completed, and the startup/shakedown was completed in June 1993. Long-term performance testing began in July 1993 and will be conducted for two years. Test facility description and test plans, as well as start-up issues and preliminary commissioning test results are reported in this paper.

  11. Accidents with sulfuric acid

    OpenAIRE

    Rajković Miloš B.

    2006-01-01

    Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eigh...

  12. Sulfur Flow Analysis for New Generation Steel Manufacturing Process

    Institute of Scientific and Technical Information of China (English)

    HU Chang-qing; ZHANG Chun-xia; HAN Xiao-wei; YIN Rui-yu

    2008-01-01

    Sulfur flow for new generation steel manufacturing process is analyzed by the method of material flow analysis,and measures for SO2 emission reduction are put forward as assessment and target intervention of the results.The results of sulfur flow analysis indicate that 90% of sulfur comes from fuels.Sulfur finally discharges from the steel manufacturing route in various steps,and the main point is BF and BOF slag desulfurization.In sintering process,the sulfur is removed by gasification,and sintering process is the main source of SO2 emission.The sulfur content of coke oven gas (COG) is an important factor affecting SO2 emission.Therefore,SO2 emission reduction should be started from the optimization and integration of steel manufacturing route,sulfur burden should be reduced through energy saving and consumption reduction,and the sulfur content of fuel should be controlled.At the same time,BF and BOF slag desulfurization should be optimized further and coke oven gas and sintering exhausted gas desulfurization should be adopted for SO2 emission reduction and reuse of resource,to achieve harmonic coordination of economic,social,and environmental effects for sustainable development.

  13. The role of crystallization-driven exsolution on the sulfur mass balance in volcanic arc magmas

    Science.gov (United States)

    Su, Y.; Huber, Christian; Bachmann, Olivier; Zajacz, Zoltán.; Wright, Heather; Vazquez, Jorge

    2016-08-01

    The release of large amounts of sulfur to the stratosphere during explosive eruptions affects the radiative balance in the atmosphere and consequentially impacts climate for up to several years after the event. Quantitative estimations of the processes that control the mass balance of sulfur between melt, crystals, and vapor bubbles is needed to better understand the potential sulfur yield of individual eruption events and the conditions that favor large sulfur outputs to the atmosphere. The processes that control sulfur partitioning in magmas are (1) exsolution of volatiles (dominantly H2O) during decompression (first boiling) and during isobaric crystallization (second boiling), (2) the crystallization and breakdown of sulfide or sulfate phases in the magma, and (3) the transport of sulfur-rich vapor (gas influx) from deeper unerupted regions of the magma reservoir. Vapor exsolution and the formation/breakdown of sulfur-rich phases can all be considered as closed-system processes where mass balance arguments are generally easier to constrain, whereas the contribution of sulfur by vapor transport (open system process) is more difficult to quantify. The ubiquitous "excess sulfur" problem, which refers to the much higher sulfur mass released during eruptions than what can be accounted for by amount of sulfur originally dissolved in erupted melt, as estimated from melt inclusion sulfur concentrations (the "petrologic estimate"), reflects the challenges in closing the sulfur mass balance between crystals, melt, and vapor before and during a volcanic eruption. In this work, we try to quantify the relative importance of closed- and open-system processes for silicic arc volcanoes using kinetic models of sulfur partitioning during exsolution. Our calculations show that crystallization-induced exsolution (second boiling) can generate a significant fraction of the excess sulfur observed in crystal-rich arc magmas. This result does not negate the important role of vapor

  14. 77 FR 65840 - Section 610 Reviews of Heavy-Duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur...

    Science.gov (United States)

    2012-10-31

    ...-Duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements (Heavy-Duty 610... EPA's 610 Review related to Heavy-Duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur... Review of Heavy-Duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements...

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

    Science.gov (United States)

    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.

  16. Effectiveness of porous covers for control of ammonia, reduced sulfur compounds, total hydrocarbons, selected volatile organic compounds, and odor from hog manure storage lagoons.

    Science.gov (United States)

    Regmi, Shekhar; Ongwandee, Maneerat; Morrison, Glenn; Fitch, Mark; Surampalli, Rao

    2007-06-01

    Anaerobic lagoons are a major source of odor at concentrated animal feeding operations. Seven different kinds of artificial (geotextile and polyethylene foam) and natural (straw and redwood) permeable lagoon covers were evaluated for their potential to reduce odorous emissions generated by anaerobic waste lagoons. A novel floating sampling raft was constructed and used to simultaneously evaluate the effectiveness of lagoon covers on an operating swine waste lagoon. The air collected from the raft was evaluated for odor, total reduced sulfur (TRS) compounds, ammonia, total hydrocarbons, dimethyldisulfide, and trimethylamine. The emission rates from the lagoon were highly variable both temporally and spatially. All of the lagoon covers substantially reduced TRS emissions and odor. Geotextile fabric and a recycled foam cover exhibited the greatest reduction in total hydrocarbon emissions; natural covers were less effective. Because of consistently low emission rates of ammonia, no statistically significant reduction of ammonia emissions were observed from any of the lagoon covers.

  17. The role of crystallization-driven exsolution on the sulfur mass balance in volcanic arc magmas

    Science.gov (United States)

    Su, Yanqing; Huber, Christian; Bachmann, Olivier; Zajacz, Zoltán; Wright, Heather M.; Vazquez, Jorge A.

    2016-01-01

    The release of large amounts of sulfur to the stratosphere during explosive eruptions affects the radiative balance in the atmosphere and consequentially impacts climate for up to several years after the event. Quantitative estimations of the processes that control the mass balance of sulfur between melt, crystals, and vapor bubbles is needed to better understand the potential sulfur yield of individual eruption events and the conditions that favor large sulfur outputs to the atmosphere. The processes that control sulfur partitioning in magmas are (1) exsolution of volatiles (dominantly H2O) during decompression (first boiling) and during isobaric crystallization (second boiling), (2) the crystallization and breakdown of sulfide or sulfate phases in the magma, and (3) the transport of sulfur-rich vapor (gas influx) from deeper unerupted regions of the magma reservoir. Vapor exsolution and the formation/breakdown of sulfur-rich phases can all be considered as closed-system processes where mass balance arguments are generally easier to constrain, whereas the contribution of sulfur by vapor transport (open system process) is more difficult to quantify. The ubiquitous “excess sulfur” problem, which refers to the much higher sulfur mass released during eruptions than what can be accounted for by amount of sulfur originally dissolved in erupted melt, as estimated from melt inclusion sulfur concentrations (the “petrologic estimate”), reflects the challenges in closing the sulfur mass balance between crystals, melt, and vapor before and during a volcanic eruption. In this work, we try to quantify the relative importance of closed- and open-system processes for silicic arc volcanoes using kinetic models of sulfur partitioning during exsolution. Our calculations show that crystallization-induced exsolution (second boiling) can generate a significant fraction of the excess sulfur observed in crystal-rich arc magmas. This result does not negate the important role of

  18. Lithium sulfur batteries and electrolytes and sulfur cathodes thereof

    Energy Technology Data Exchange (ETDEWEB)

    Visco, Steven J.; Goncharenko, Nikolay; Nimon, Vitaliy; Petrov, Alexei; Nimon, Yevgeniy S.; De Jonghe, Lutgard C.; Katz, Bruce D.; Loginova, Valentina

    2017-05-23

    Lithium sulfur battery cells that use water as an electrolyte solvent provide significant cost reductions. Electrolytes for the battery cells may include water solvent for maintaining electroactive sulfur species in solution during cell discharge and a sufficient amount of a cycle life-enhancing compound that facilitates charging at the cathode. The combination of these two components enhances one or more of the following cell attributes: energy density, power density and cycle life. For instance, in applications where cost per Watt-Hour (Wh) is paramount, such as grid storage and traction applications, the use of an aqueous electrolyte in combination with inexpensive sulfur as the cathode active material can be a key enabler for the utility and automotive industries, for example, providing a cost effective and compact solution for load leveling, electric vehicles and renewable energy storage. Sulfur cathodes, and methods of fabricating lithium sulfur cells, in particular for loading lithium sulfide into the cathode structures, provide further advantages.

  19. Sulfur in Cometary Dust

    Science.gov (United States)

    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.

  20. Sulfur plant start-up

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, Hank; Grigson, Susan [Ortloff Engineers Ltd. (United States)

    2002-02-01

    The authors discuss an Ortloff sulfur plant design concept using the Claus reaction that differs from accepted 'industry practice': cold reactor bed start-up. The process is designed to eliminate catalyst sulfation, heat damage and furnace overheating in sulfur recovery units. (UK)

  1. Ultra Low Sulfur Home Heating Oil Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Batey, John E. [Energy Research Center, Inc., Easton, CT (United States); McDonald, Roger [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-09-30

    This Ultra Low Sulfur (ULS) Home Heating Oil Demonstration Project was funded by the New York State Energy Research and Development Authority (NYSERDA) and has successfully quantified the environmental and economic benefits of switching to ULS (15 PPM sulfur) heating oil. It advances a prior field study of Low Sulfur (500 ppm sulfur) heating oil funded by NYSERDA and laboratory research conducted by Brookhaven National Laboratory (BNL) and Canadian researchers. The sulfur oxide and particulate matter (PM) emissions are greatly reduced as are boiler cleaning costs through extending cleaning intervals. Both the sulfur oxide and PM emission rates are directly related to the fuel oil sulfur content. The sulfur oxide and PM emission rates approach near-zero levels by switching heating equipment to ULS fuel oil, and these emissions become comparable to heating equipment fired by natural gas. This demonstration project included an in-depth review and analysis of service records for both the ULS and control groups to determine any difference in the service needs for the two groups. The detailed service records for both groups were collected and analyzed and the results were entered into two spreadsheets that enabled a quantitative side-by-side comparison of equipment service for the entire duration of the ULS test project. The service frequency for the ULS and control group were very similar and did indicate increased service frequency for the ULS group. In fact, the service frequency with the ULS group was slightly less (7.5 percent) than the control group. The only exception was that three burner fuel pump required replacement for the ULS group and none were required for the control group.

  2. Ex- and in-situ investigations of sulfur diffusion into Cu(In,Ga)Se{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, B.J., E-mail: bjm.mueller@web.de [Robert Bosch GmbH, Corporate Research and Advance Engineering, Advanced Functional Materials and Microsystems, D-70839 Gerlingen (Germany); Institute of Micro- and Nanomaterials, University of Ulm, Albert-Einstein-Allee 47, D-89081 Ulm (Germany); Mock, M.; Haug, V. [Robert Bosch GmbH, Corporate Research and Advance Engineering, Advanced Functional Materials and Microsystems, D-70839 Gerlingen (Germany); Hergert, F. [Bosch Solar CISTech GmbH, D-14772 Brandenburg (Germany); Koehler, T.; Zweigart, S. [Robert Bosch GmbH, Corporate Research and Advance Engineering, Advanced Functional Materials and Microsystems, D-70839 Gerlingen (Germany); Herr, U., E-mail: ulrich.herr@uni-ulm.de [Institute of Micro- and Nanomaterials, University of Ulm, Albert-Einstein-Allee 47, D-89081 Ulm (Germany)

    2015-05-01

    In this article we investigate the incorporation of sulfur into Cu(In,Ga)Se{sub 2} thin films by controlled diffusion. For this purpose, the conventional stacked elemental layer process has been extended by a subsequent sulfur diffusion step. The sulfur gradient is desirable for achieving a graded band gap of the absorber layer which allows to optimize the absorption properties. The sulfur incorporation can be influenced by the sulfurization temperature, the sulfur supply (partial pressure) and the temperature of the Cu(In,Ga)Se{sub 2} pre-treatment. The presence of binary selenides and small grains enhances the speed of sulfur incorporation. A combination of Raman spectroscopy and in-situ as well as ex-situ X-ray diffraction has been used in order to obtain detailed information about the diffusion process. The sulfur incorporation occurs at sulfurization temperatures in the range of 575 °C in step 1. By decreasing the selenization temperature in step 2 the amount of sulfur incorporation is enhanced. Furthermore an additional defect spinel phase CuIn{sub 5}S{sub 8} is obtained when sulfur is supplied in excess. - Highlights: • Controllable sulfur incorporation into Cu(In,Ga)Se{sub 2} • Diffusion coefficients were determined with the help of in-situ XRD. • When providing sulfur in excess the defect spinel phase is formed.

  3. Controlled expression of nif and isc iron-sulfur protein maturation components reveals target specificity and limited functional replacement between the two systems.

    Science.gov (United States)

    Dos Santos, Patricia C; Johnson, Deborah C; Ragle, Brook E; Unciuleac, Mihaela-Carmen; Dean, Dennis R

    2007-04-01

    The nitrogen-fixing organism Azotobacter vinelandii contains at least two systems that catalyze formation of [Fe-S] clusters. One of these systems is encoded by nif genes, whose products supply [Fe-S] clusters required for maturation of nitrogenase. The other system is encoded by isc genes, whose products are required for maturation of [Fe-S] proteins that participate in general metabolic processes. The two systems are similar in that they include an enzyme for the mobilization of sulfur (NifS or IscS) and an assembly scaffold (NifU or IscU) upon which [Fe-S] clusters are formed. Normal cellular levels of the Nif system, which supplies [Fe-S] clusters for the maturation of nitrogenase, cannot also supply [Fe-S] clusters for the maturation of other cellular [Fe-S] proteins. Conversely, when produced at the normal physiological levels, the Isc system cannot supply [Fe-S] clusters for the maturation of nitrogenase. In the present work we found that such target specificity for IscU can be overcome by elevated production of NifU. We also found that NifU, when expressed at normal levels, is able to partially replace the function of IscU if cells are cultured under low-oxygen-availability conditions. In contrast to the situation with IscU, we could not establish conditions in which the function of IscS could be replaced by NifS. We also found that elevated expression of the Isc components, as a result of deletion of the regulatory iscR gene, improved the capacity for nitrogen-fixing growth of strains deficient in either NifU or NifS.

  4. Biotransformation of sulfur and nitrogen oxides in stack gases

    Energy Technology Data Exchange (ETDEWEB)

    Govind, R.; Puligadda, R. [Univ. of Cincinnati, OH (United States); Bishop, D.F. [Environmental Protection Agency, Cincinnati, OH (United States)

    1995-10-01

    The Nation`s large supply of high sulfur coal and increasingly stringent emission regulation led to priority development of advanced innovative processes for treating pollutants in flue gases from coal combustion. The principal pollutants in flue gases, sulfur oxides (SO{sub 2},SO{sub 3}) and nitrogen oxides (NO{sub x}) cause acid rain. Thus, the Department of Energy`s Clean Coal Program is funding projects to commercialize technologies that minimize emission of sulfur and nitrogen oxides at power plants. This report describes the controlled use of bioconversion processes to remove the oxides from flue gas. Two bioreactor experiments were conducted to investigate the removal of sulfur dioxide, nitrogen oxides, and carbon dioxide from stack gases.

  5. Sulfur status in long distance runners

    Science.gov (United States)

    Kovacs, L.; Zamboni, C.; Lourenço, T.; Macedo, D.

    2015-07-01

    In sports medicine, sulfur plays an important role and its deficiency can cause muscle injury affecting the performance of the athletes. However, its evaluation is unusual in conventional clinical practice. In this study the sulfur levels were determined in Brazilian amateur athlete's blood using Neutron Activation Analyses (NAA) technique. Twenty six male amateur runners, age 18 to 36 years, participated of this study. The athletes had a balanced diet, without multivitamin/mineral supplements. The blood collection was performed at LABEX (Laboratoriode Bioquimica do Exercicio, UNICAMP-SP) and the samples were irradiated for 300 seconds in a pneumatic station in the nuclear reactor (IEA-R1, 3-4.5MW, pool type) at IPEN/CNEN-SP. The results were compared with the control group (subjects of same age but not involved with physical activities) and showed that the sulfur concentration was 44% higher in amateurs athletes than control group. These data can be considered for preparation of balanced diet, as well as contributing for proposing new protocols of clinical evaluation.

  6. Fossilization of melanosomes via sulfurization.

    Science.gov (United States)

    McNamara, Maria E; van Dongen, Bart E; Lockyer, Nick P; Bull, Ian D; Orr, Patrick J

    2016-05-01

    Fossil melanin granules (melanosomes) are an important resource for inferring the evolutionary history of colour and its functions in animals. The taphonomy of melanin and melanosomes, however, is incompletely understood. In particular, the chemical processes responsible for melanosome preservation have not been investigated. As a result, the origins of sulfur-bearing compounds in fossil melanosomes are difficult to resolve. This has implications for interpretations of original colour in fossils based on potential sulfur-rich phaeomelanosomes. Here we use pyrolysis gas chromatography mass spectrometry (Py-GCMS), fourier transform infrared spectroscopy (FTIR) and time of flight secondary ion mass spectrometry (ToF-SIMS) to assess the mode of preservation of fossil microstructures, confirmed as melanosomes based on the presence of melanin, preserved in frogs from the Late Miocene Libros biota (NE Spain). Our results reveal a high abundance of organosulfur compounds and non-sulfurized fatty acid methyl esters in both the fossil tissues and host sediment; chemical signatures in the fossil tissues are inconsistent with preservation of phaeomelanin. Our results reflect preservation via the diagenetic incorporation of sulfur, i.e. sulfurization (natural vulcanization), and other polymerization processes. Organosulfur compounds and/or elevated concentrations of sulfur have been reported from melanosomes preserved in various invertebrate and vertebrate fossils and depositional settings, suggesting that preservation through sulfurization is likely to be widespread. Future studies of sulfur-rich fossil melanosomes require that the geochemistry of the host sediment is tested for evidence of sulfurization in order to constrain interpretations of potential phaeomelanosomes and thus of original integumentary colour in fossils.

  7. 升华硫配合杀螨剂防治蜂螨效果的比较研究%Control Effect of Sublimed Sulfur Paired with Acaricide on Bee Mites

    Institute of Scientific and Technical Information of China (English)

    余玉生; 张祖芸; 卢焕仙; 赵洪木; 张学文

    2011-01-01

    [Objective] This study aimed to compare the effects of sublimed sulfur and acaricide on controlling bee mites. [Method] Three independent experiments were carried out in the same apiary during 2007 -2009. [Results] The results showed that this method is effective in eliminating mites settled on combs or hidden during pupae phase, but not in controlling the mites parasitized on adult bees. The control effect on killing Varroa destructor after treated appeared optimal in the first day and then decreased, and that on killing Tvopilaelaps clareae happened in the second day. The results indicated that the effect would be much better if the bees can be treated 1 time to 2 times again in the following 2 -5days after the first treatment. Back to data pool, we found that the treatment of sublimed sulfur paired with acaricide is effective in controlling V. destructor and T. clareae. [Conclusion] This technique could facilitate the apicultural production in the regions suffered from V. destructor and T. clareae.%[目的]比较升华硫配合杀蟥剂防治蜂螨效果.[方法]2007~2009年3年3次于同一个蜂场采用同一种方法对升华硫配合杀螨剂防治蜂螨效果进行了试验.[结果]升华硫配合杀螨剂对于消灭存在蜂脾上及寄生于封盖蛹的蜂螨有明显效果,对于消灭成年工蜂身体上的蜂螨效果不明显.施药后杀灭大蜂螨的效果以第1天最佳,此后逐日减少;杀灭小蜂螨的效果以第2天最佳,此后逐日减少,表明在2~5 d再施治1~2次,可达到理想的防治效果.[结论]该防治技术大、小蜂螨严重危害地区的养蜂生产提供服务.

  8. Sulfur cycling and metabolism of phototrophic and filamentous sulfur bacteria

    Science.gov (United States)

    Guerrero, R.; Brune, D.; Poplawski, R.; Schmidt, T. M.

    1985-01-01

    Phototrophic sulfur bacteria taken from different habitate (Alum Rock State Park, Palo Alto salt marsh, and Big Soda Lake) were grown on selective media, characterized by morphological and pigment analysis, and compared with bacteria maintained in pure culture. A study was made of the anaerobic reduction of intracellular sulfur globules by a phototrophic sulfur bacterium (Chromatium vinosum) and a filamentous aerobic sulfur bacterium (Beggiatoa alba). Buoyant densities of different bacteria were measured in Percoll gradients. This method was also used to separate different chlorobia in mixed cultures and to assess the relative homogeneity of cultures taken directly or enriched from natural samples (including the purple bacterial layer found at a depth of 20 meters at Big Soda Lake.) Interactions between sulfide oxidizing bacteria were studied.

  9. Effect of Alginure® (seaweed extract, Myco-Sin®VIN (sulfuric clay and Polyversum® (Pythium oligandrum Drechs. on yield and disease control in organic strawberries

    Directory of Open Access Journals (Sweden)

    Stanislav Boček

    2012-01-01

    Full Text Available In 2011 and 2012 three commercial products Alginure® (seaweed extract, Myco-Sin® VIN (sulfuric acid clay with yeast and plant extracts and Polyversum® (spores of Pythium oligandrum were tested in field experiment with strawberry cv. ‘Induka’ under the conditions of organic growing system. The aim of the study was to determine the effect of the preparations on yield, fruit quality and diseases control. The preparations were applied five times during flowering. We assessed total yield, marketable and unmarketable yields, average fruit weight, grey mould incidence on fruits caused by Botrytis cinerea and leaf spot severity caused by Mycosphaerella fragariae. Efficacy (% of preparations was calculated. Preparations did not show positive effect on yields parameters. Total and marketable yields were not significantly different to untreated control in both years. Nevertheless considerable increase of yields from 2011 to 2012 was observed in strawberries treated by biofungicide Polyversum®. Preparations did not significantly reduce the incidence of grey mould. Alginure® showed the best results by efficacy 39.6 % and 57.4 %, respectively. All preparations provided very low, less than 10% efficacy to control leaf spot severity.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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..

  12. Dazhou Becomes China's Sulfur Base

    Institute of Scientific and Technical Information of China (English)

    Zhang He

    2008-01-01

    @@ Located at the juncture of Sichuan, Hubei, Shaanxi provinces and Chongqing municipality, Dazhou,which is a city in the eastem part of Southwest China's Sichuan Province and has convenient transport facilities, boasts natural gas reserves of 3.8 trillion cubic meters, of which 660 billion cubic meters have been found. It will make full use of its natural gas reserves to build Asia's largest sulfur producing base by 2010 when its annual sulfur output is expected to surpass 4 million tons.

  13. Standard practice for preparing sulfur prints for macrostructural evaluation

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This practice provides information required to prepare sulfur prints (also referred to as Baumann Prints) of most ferrous alloys to reveal the distribution of sulfide inclusions. 1.2 The sulfur print reveals the distribution of sulfides in steels with bulk sulfur contents between about 0.010 and 0.40 weight percent. 1.3 Certain steels contain complex sulfides that do not respond to the test solutions, for example, steels containing titanium sulfides or chromium sulfides. 1.4 The sulfur print test is a qualitative test. The density of the print image should not be used to assess the sulfur content of a steel. Under carefully controlled conditions, it is possible to compare print image intensities if the images are formed only by manganese sulfides. 1.5 The sulfur print image will reveal details of the solidification pattern or metal flow from hot or cold working on appropriately chosen and prepared test specimens. 1.6 This practice does not address acceptance criteria based on the use of the method. ...

  14. The Reactive Sulfur Species Concept: 15 Years On

    Science.gov (United States)

    Giles, Gregory I.; Nasim, Muhammad Jawad; Ali, Wesam; Jacob, Claus

    2017-01-01

    Fifteen years ago, in 2001, the concept of “Reactive Sulfur Species” or RSS was advocated as a working hypothesis. Since then various organic as well as inorganic RSS have attracted considerable interest and stimulated many new and often unexpected avenues in research and product development. During this time, it has become apparent that molecules with sulfur-containing functional groups are not just the passive “victims” of oxidative stress or simple conveyors of signals in cells, but can also be stressors in their own right, with pivotal roles in cellular function and homeostasis. Many “exotic” sulfur-based compounds, often of natural origin, have entered the fray in the context of nutrition, ageing, chemoprevention and therapy. In parallel, the field of inorganic RSS has come to the forefront of research, with short-lived yet metabolically important intermediates, such as various sulfur-nitrogen species and polysulfides (Sx2−), playing important roles. Between 2003 and 2005 several breath-taking discoveries emerged characterising unusual sulfur redox states in biology, and since then the truly unique role of sulfur-dependent redox systems has become apparent. Following these discoveries, over the last decade a “hunt” and, more recently, mining for such modifications has begun—and still continues—often in conjunction with new, innovative and complex labelling and analytical methods to capture the (entire) sulfur “redoxome”. A key distinction for RSS is that, unlike oxygen or nitrogen, sulfur not only forms a plethora of specific reactive species, but sulfur also targets itself, as sulfur containing molecules, i.e., peptides, proteins and enzymes, preferentially react with RSS. Not surprisingly, today this sulfur-centred redox signalling and control inside the living cell is a burning issue, which has moved on from the predominantly thiol/disulfide biochemistry of the past to a complex labyrinth of interacting signalling and control

  15. Optimizing stratospheric sulfur geoengineering by seasonally changing sulfur injections

    Science.gov (United States)

    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

  16. Sulfur-impregnated disordered carbon nanotubes cathode for lithium-sulfur batteries.

    Science.gov (United States)

    Guo, Juchen; Xu, Yunhua; Wang, Chunsheng

    2011-10-12

    The commercialization of lithium-sulfur batteries is hindered by low cycle stability and low efficiency, which are induced by sulfur active material loss and polysulfide shuttle reaction through dissolution into electrolyte. In this study, sulfur-impregnated disordered carbon nanotubes are synthesized as cathode material for the lithium-sulfur battery. The obtained sulfur-carbon tube cathodes demonstrate superior cyclability and Coulombic efficiency. More importantly, the electrochemical characterization indicates a new stabilization mechanism of sulfur in carbon induced by heat treatment.

  17. The beauty of frost: nano-sulfur assembly via low pressure vapour deposition.

    Science.gov (United States)

    Wang, Yu; Chen, Lu; Scudiero, Louis; Zhong, Wei-Hong

    2015-11-14

    A low pressure vapour deposition (LPVD) technique is proposed as an environmentally friendly, cost-effective and versatile strategy for fabrication of sulfur nanomaterials. By controlling the characteristics of the deposit substrate for the LPVD, various sulfur-based nanomaterials have been obtained through a substrate-induced self-assembly process.

  18. Biochemistry of Dissimilatory Sulfur Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Blake II, R.

    2003-05-30

    The long term goals of this research were to define the substrate oxidation pathways, the electron transport mechanisms, and the modes of energy conservation employed during the dissimilatory oxidation of sulfur practiced by various species of the thiobacilli. Specific adhesion of the thiobacilli to elemental sulfur was studied by electrical impedance, dynamic light scattering, laser Doppler velocimetry, and optical trapping methods. The conclusion is that the thiobacilli appear to express specific receptors that enable the bacteria to recognize and adhere to insoluble sulfur. The enzyme tetrathionate oxidase was purified from two species of the thiobacilli. Extensive structural and functional studies were conducted on adenosine 5'-phosphosulfate reductase purified from cell-free extracts of Thiobacillus denitrificans. The kinetic mechanism of rhodanese was studied.

  19. HYBRID SULFUR RECOVERY PROCESS FOR NATURAL GAS UPGRADING

    Energy Technology Data Exchange (ETDEWEB)

    Girish Srinivas; Steven C. Gebhard; David W. DeBerry

    2001-05-01

    This first quarter report of 2001 describes progress on a project funded by the U.S. Department of Energy (DOE) to test a hybrid sulfur recovery process for natural gas upgrading. The process concept represents a low cost option for direct treatment of natural gas streams to remove H{sub 2}S in quantities equivalent to 0.2-25 metric tons (LT) of sulfur per day. This process is projected to have lower capital and operating costs than the competing technologies, amine/aqueous iron liquid redox and amine/Claus/tail gas treating, and have a smaller plant footprint, making it well suited to both on-shore and offshore applications. CrystaSulf{trademark} (service mark of Gas Research Institute) is a new nonaqueous sulfur recovery process that removes hydrogen sulfide (H{sub 2}S) from gas streams and converts it into elemental sulfur. CrystaSulf features high sulfur recovery similar to aqueous-iron liquid redox sulfur recovery processes, but differs from the aqueous processes in that CrystaSulf controls the location where elemental sulfur particles are formed. In the hybrid process, approximately 1/3 of the total H{sub 2}S in the natural gas is first oxidized to SO{sub 2} at low temperatures over a heterogeneous catalyst. Low temperature oxidation is done so that the H{sub 2}S can be oxidized in the presence of methane and other hydrocarbons without oxidation of the hydrocarbons. The project involves the development of a catalyst using laboratory/bench-scale catalyst testing, and then demonstration of the catalyst at CrystaTech's pilot plant in west Texas. During this reporting periods new catalyst formulations were tested. The experiments showed that the newest catalyst has slightly better performance, but catalyst TDA No.2 is still superior overall for use with the hybrid CrystaSulf process due to lower costs. Plans for catalyst pelletization and continued testing are described.

  20. Pyrite sulfur isotopes reveal glacial-interglacial environmental changes

    Science.gov (United States)

    Pasquier, Virgil; Sansjofre, Pierre; Rabineau, Marina; Revillon, Sidonie; Houghton, Jennifer; Fike, David A.

    2017-06-01

    The sulfur biogeochemical cycle plays a key role in regulating Earth’s surface redox through diverse abiotic and biological reactions that have distinctive stable isotopic fractionations. As such, variations in the sulfur isotopic composition (δ34S) of sedimentary sulfate and sulfide phases over Earth history can be used to infer substantive changes to the Earth’s surface environment, including the rise of atmospheric oxygen. Such inferences assume that individual δ34S records reflect temporal changes in the global sulfur cycle; this assumption may be well grounded for sulfate-bearing minerals but is less well established for pyrite-based records. Here, we investigate alternative controls on the sedimentary sulfur isotopic composition of marine pyrite by examining a 300-m drill core of Mediterranean sediments deposited over the past 500,000 y and spanning the last five glacial-interglacial periods. Because this interval is far shorter than the residence time of marine sulfate, any change in the sulfur isotopic record preserved in pyrite (δ34Spyr) necessarily corresponds to local environmental changes. The stratigraphic variations (>76‰) in the isotopic data reported here are among the largest ever observed in pyrite, and are in phase with glacial-interglacial sea level and temperature changes. In this case, the dominant control appears to be glacial-interglacial variations in sedimentation rates. These results suggest that there exist important but previously overlooked depositional controls on sedimentary sulfur isotope records, especially associated with intervals of substantial sea level change. This work provides an important perspective on the origin of variability in such records and suggests meaningful paleoenvironmental information can be derived from pyrite δ34S records.

  1. Sulfur Impurities and the Microstructure of Alumina Scales

    Science.gov (United States)

    Smialek, James L.

    1997-01-01

    The relationship between the microstructure of alumina scales, adhesion, and sulfur content was examined through a series of nickel alloys oxidized in 1100 to 1200 deg. C cyclic or isothermal exposures in air. In cyclic tests of undoped NiCrAl, adhesion was produced when the sulfur content was reduced, without any change in scale microstructure. Although interfacial voids were not observed in cyclic tests of NiCrAl, they were promoted by long-term isothermal exposures, by sulfur doping, and in most exposures of NiAl. Two single crystal superalloys, PWA 1480 and Rene' N5, were also tested, either in the as-received condition or after the sulfur content had been reduced to less than 1 ppmw by hydrogen annealing. The unannealed alloys always exhibited spalling to bare metal, but interfacial voids were not observed consistently. Desulfurized PWA 1480 and Rene' N5 exhibited remarkable adhesion and no voidage for either isothermal or cyclic exposures. The most consistent microstructural feature was that, for the cases where voids did form, the scale undersides exhibited corresponding areas with ridged oxide grain boundaries. Voids were not required for spallation nor were other microstructural features essential for adhesion. These observations are consistent with the model whereby scale spallation is controlled primarily by interfacial sulfur segregation and the consequent degradation of oxide-metal bonding.

  2. Physiology of Haloalkaliphilic Sulfur-oxidizing Bacteria

    NARCIS (Netherlands)

    Banciu, H.L.

    2004-01-01

    The inorganic sulfur oxidation by obligate haloalkaliphilic chemolithoautotrophs was only recently discovered and investigated. These autotrophic sulfur oxidizing bacteria (SOB), capable of oxidation of inorganic sulfur compounds at moderate to high salt concentration and at high pH, can be divided

  3. Genetic engineering of sulfur-degrading Sulfolobus

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Sulfur: its clinical and toxicologic aspects.

    Science.gov (United States)

    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.

  5. Physiology of Haloalkaliphilic Sulfur-oxidizing Bacteria

    NARCIS (Netherlands)

    Banciu, H.L.

    2004-01-01

    The inorganic sulfur oxidation by obligate haloalkaliphilic chemolithoautotrophs was only recently discovered and investigated. These autotrophic sulfur oxidizing bacteria (SOB), capable of oxidation of inorganic sulfur compounds at moderate to high salt concentration and at high pH, can be divided

  6. Volatile earliest Triassic sulfur cycle

    DEFF Research Database (Denmark)

    Schobben, Martin; Stebbins, Alan; Algeo, Thomas J.

    2017-01-01

    Marine biodiversity decreases and ecosystem destruction during the end-Permian mass extinction (EPME) have been linked to widespread marine euxinic conditions. Changes in the biogeochemical sulfur cycle, microbial sulfate reduction (MSR), and marine dissolved sulfate concentrations during the Per...... of widespread euxinic conditions, posing a sustained threat to marine life during the Early Triassic....

  7. Bacterial iron-sulfur cluster sensors in mammalian pathogens

    Science.gov (United States)

    Miller, Halie K.; Auerbuch, Victoria

    2015-01-01

    Iron-sulfur clusters act as important cofactors for a number of transcriptional regulators in bacteria, including many mammalian pathogens. The sensitivity of iron-sulfur clusters to iron availability, oxygen tension, and reactive oxygen and nitrogen species enables bacteria to use such regulators to adapt their gene expression profiles rapidly in response to changing environmental conditions. In this review, we discuss how the [4Fe-4S] or [2Fe-2S] cluster-containing regulators FNR, Wbl, aconitase, IscR, NsrR, SoxR, and AirSR contribute to bacterial pathogenesis through control of both metabolism and classical virulence factors. In addition, we briefly review mammalian iron homeostasis as well as oxidative/nitrosative stress to provide context for understanding the function of bacterial iron-sulfur cluster sensors in different niches within the host. PMID:25738802

  8. High-resolution quadruple sulfur isotope analyses of 3.2 Ga pyrite from the Barberton Greenstone Belt in South Africa reveal distinct environmental controls on sulfide isotopic arrays

    Science.gov (United States)

    Roerdink, Desiree L.; Mason, Paul R. D.; Whitehouse, Martin J.; Reimer, Thomas

    2013-09-01

    Multiple sulfur isotopes in Paleoarchean pyrite record valuable information on atmospheric processes and emerging microbial activity in the early sulfur cycle. Here, we report quadruple sulfur isotope data (32S, 33S, 34S, 36S) analyzed by secondary ion mass spectrometry from pyrite in a 3.26-3.23 Ga sedimentary barite deposit in the Barberton Greenstone Belt, South Africa. Our results demonstrate the presence of distinct pyrite populations and reproducible isotopic arrays in barite-free and barite-rich samples. The most 34S-depleted signatures with weakly positive Δ33S/δ34S were found in disseminated pyrite in barite, whereas positive Δ33S-values with negative Δ33S/δ34S and Δ36S/Δ33S = -0.9 ± 0.2 were exclusively observed in pyrite hosted by chert, dolomite, conglomerate and breccia. We interpret these variations to be related to local redox reactions and mixing in the sulfide phase, rather than representing primary atmospheric variability alone. The strong correlation between lithology and isotopic composition indicates distinct environments of sulfide formation linked to local sulfate concentrations and fluctuating inputs from different sulfur metabolisms. Strongly 34S-depleted sulfide was formed by microbial sulfate reduction at [SO42-] > 200 μM during deposition of barite-rich sediments, whereas isotope effects were suppressed when sulfate levels decreased during deposition of terrigeneous clastic rocks. Positive Δ33S-values indicate an increased input of sulfide derived from elemental sulfur metabolisms when sulfate concentrations fell below 200 μM. Our results support an important role for local sulfate concentrations on the expression of biogenic sulfur isotope signatures in some of the oldest rocks on Earth.

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

    Science.gov (United States)

    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.

  10. Steep spatial gradients of volcanic and marine sulfur in Hawaiian rainfall and ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Bern, Carleton R., E-mail: cbern@usgs.gov [U.S. Geological Survey, Denver Federal Center, Denver, CO 80225 (United States); Department of Geography University of California, Santa Barbara, CA 93106-4060 (United States); Chadwick, Oliver A. [Department of Geography University of California, Santa Barbara, CA 93106-4060 (United States); Kendall, Carol [U.S. Geological Survey, Menlo Park, CA (United States); Pribil, Michael J. [U.S. Geological Survey, Denver Federal Center, Denver, CO 80225 (United States)

    2015-05-01

    Sulfur, a nutrient required by terrestrial ecosystems, is likely to be regulated by atmospheric processes in well-drained, upland settings because of its low concentration in most bedrock and generally poor retention by inorganic reactions within soils. Environmental controls on sulfur sources in unpolluted ecosystems have seldom been investigated in detail, even though the possibility of sulfur limiting primary production is much greater where atmospheric deposition of anthropogenic sulfur is low. Here we measure sulfur isotopic compositions of soils, vegetation and bulk atmospheric deposition from the Hawaiian Islands for the purpose of tracing sources of ecosystem sulfur. Hawaiian lava has a mantle-derived sulfur isotopic composition (δ{sup 34}S VCDT) of − 0.8‰. Bulk deposition on the island of Maui had a δ{sup 34}S VCDT that varied temporally, spanned a range from + 8.2 to + 19.7‰, and reflected isotopic mixing from three sources: sea-salt (+ 21.1‰), marine biogenic emissions (+ 15.6‰), and volcanic emissions from active vents on Kilauea Volcano (+ 0.8‰). A straightforward, weathering-driven transition in ecosystem sulfur sources could be interpreted in the shift from relatively low (0.0 to + 2.7‰) to relatively high (+ 17.8 to + 19.3‰) soil δ{sup 34}S values along a 0.3 to 4100 ka soil age-gradient, and similar patterns in associated vegetation. However, sub-kilometer scale spatial variation in soil sulfur isotopic composition was found along soil transects assumed by age and mass balance to be dominated by atmospheric sulfur inputs. Soil sulfur isotopic compositions ranged from + 8.1 to + 20.3‰ and generally decreased with increasing elevation (0–2000 m), distance from the coast (0–12 km), and annual rainfall (180–5000 mm). Such trends reflect the spatial variation in marine versus volcanic inputs from atmospheric deposition. Broadly, these results illustrate how the sources and magnitude of atmospheric deposition can exert controls

  11. Rhodanese functions as sulfur supplier for key enzymes in sulfur energy metabolism.

    Science.gov (United States)

    Aussignargues, Clément; Giuliani, Marie-Cécile; Infossi, Pascale; Lojou, Elisabeth; Guiral, Marianne; Giudici-Orticoni, Marie-Thérèse; Ilbert, Marianne

    2012-06-08

    How microorganisms obtain energy is a challenging topic, and there have been numerous studies on the mechanisms involved. Here, we focus on the energy substrate traffic in the hyperthermophilic bacterium Aquifex aeolicus. This bacterium can use insoluble sulfur as an energy substrate and has an intricate sulfur energy metabolism involving several sulfur-reducing and -oxidizing supercomplexes and enzymes. We demonstrate that the cytoplasmic rhodanese SbdP participates in this sulfur energy metabolism. Rhodaneses are a widespread family of proteins known to transfer sulfur atoms. We show that SbdP has also some unusual characteristics compared with other rhodaneses; it can load a long sulfur chain, and it can interact with more than one partner. Its partners (sulfur reductase and sulfur oxygenase reductase) are key enzymes of the sulfur energy metabolism of A. aeolicus and share the capacity to use long sulfur chains as substrate. We demonstrate a positive effect of SbdP, once loaded with sulfur chains, on sulfur reductase activity, most likely by optimizing substrate uptake. Taken together, these results lead us to propose a physiological role for SbdP as a carrier and sulfur chain donor to these key enzymes, therefore enabling channeling of sulfur substrate in the cell as well as greater efficiency of the sulfur energy metabolism of A. aeolicus.

  12. Sulfur cycling of intertidal Wadden Sea sediments (Konigshafen, Island of Sylt, Germany): sulfate reduction and sulfur gas emission

    Science.gov (United States)

    Kristensen, E.; Bodenbender, J.; Jensen, M. H.; Rennenberg, H.; Jensen, K. M.

    2000-05-01

    Sulfate reduction rates (SRR t) and reduced inorganic sulfur pools (RIS) in Wadden Sea sediment as well as sulfur gas emissions directly to the atmosphere were measured at intervals of 2 to 12 months from 1991 to 1994. Three stations were chosen in the intertidal embayment, Königshafen, representing the range of sediments found in the Wadden Sea: Organic-poor coarse sand, organic-poor and Arenicola marina inhabited medium sand, and organic-rich muddy sand. Maximum SRR t were 2 to 5 times higher in muddy sand than in the sandy sediments. The depth-integrated SRR t varied 12 to 13-fold on a seasonal basis at the three stations. Although temperature controls biochemical processes, the overall control is more complex due to the simultaneous influence of other seasonal factors such as availability of organic matter and oxidation level of surface sediment. The sedimentary RIS pools were low due to iron limitation and contained only 30% acid volatile sulfur (AVS). Muddy sand had up to an order of magnitude more RIS than the two sandy sediments. The turnover of RIS was rapid (turnover time from ˜1 to 32 h), fastest during summer and at the sandy stations. The emission of S-gases was dominated by H 2S during summer (45-67% of the total), and was highest in muddy and lowest in coarse sand. H 2S was less important in early spring (3-49% of the total). Other sulfur gases, such as COS, DMS and CS 2, each accounted for less than 20% of the total sulfur emissions with no specific temporal and spatial pattern. Due to the low content of metals in the sediment, the reduced sulfur pools are cycled rapidly with chemical and biological reoxidation at oxic-anoxic boundaries as a major sink. Thus, the emissions of H 2S account for less than 1‰ of the sulfide produced.

  13. Thermo Scientific Sulfur Dioxide Analyzer Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Springston, S. R. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-03-01

    The Sulfur Dioxide Analyzer measures sulfur dioxide based on absorbance of UV light at one wavelength by SO2 molecules which then decay to a lower energy state by emitting UV light at a longer wavelength. Specifically, SO2 + hυ1 →SO2 *→SO2 + hυ2 The emitted light is proportional to the concentration of SO2 in the optical cell. External communication with the analyzer is available through an Ethernet port configured through the instrument network of the AOS systems. The Model 43i-TLE is part of the i-series of Thermo Scientific instruments. The i-series instruments are designed to interface with external computers through the proprietary Thermo Scientific iPort Software. However, this software is somewhat cumbersome and inflexible. BNL has written an interface program in National Instruments LabView that both controls the Model 43i-TLE Analyzer AND queries the unit for all measurement and housekeeping data. The LabView vi (the software program written by BNL) ingests all raw data from the instrument and outputs raw data files in a uniform data format similar to other instruments in the AOS and described more fully in Section 6.0 below.

  14. Transporters in plant sulfur metabolism

    Directory of Open Access Journals (Sweden)

    Tamara eGigolashvili

    2014-09-01

    Full Text Available Sulfur is an essential nutrient, necessary for synthesis of many metabolites. The uptake of sulfate, primary and secondary assimilation, the biosynthesis, storage and final utilisation 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.

  15. Balancing surface adsorption and diffusion of lithium-polysulfides on nonconductive oxides for lithium–sulfur battery design

    OpenAIRE

    Tao, Xinyong; Wang, Jianguo; Liu, Chong; Wang, Haotian; Yao, Hongbin; Zheng, Guangyuan; Seh, Zhi Wei; Cai, Qiuxia; Li, Weiyang; Zhou, Guangmin; Zu, Chenxi; Cui, Yi

    2016-01-01

    Lithium–sulfur batteries have attracted attention due to their six-fold specific energy compared with conventional lithium-ion batteries. Dissolution of lithium polysulfides, volume expansion of sulfur and uncontrollable deposition of lithium sulfide are three of the main challenges for this technology. State-of-the-art sulfur cathodes based on metal-oxide nanostructures can suppress the shuttle-effect and enable controlled lithium sulfide deposition. However, a clear mechanistic understandin...

  16. [Gene mining of sulfur-containing amino acid metabolic enzymes in soybean].

    Science.gov (United States)

    Qiu, Hongmei; Hao, Wenyuan; Gao, Shuqin; Ma, Xiaoping; Zheng, Yuhong; Meng, Fanfan; Fan, Xuhong; Wang, Yang; Wang, Yueqiang; Wang, Shuming

    2014-09-01

    The genes of sulfur-containing amino acid synthetases in soybean are essential for the synthesis of sulfur-containing amino acids. Gene mining of these enzymes is the basis for the molecular assistant breeding of high sulfur-containing amino acids in soybean. In this study, using software BioMercator2.1, 113 genes of sulfur-containing amino acid enzymes and 33 QTLs controlling the sulfur-containing amino acids content were mapped onto Consensus Map 4.0, which was integrated by genetic and physical maps of soybean. Sixteen candidate genes associated to the synthesis of sulfur-containing amino acids were screened based on the synteny between gene loci and QTLs, and the effect values of QTLs. Through a bioinformatic analysis of the copy number, SNP information, and expression profile of candidate genes, 12 related enzyme genes were identified and mapped on 8 linkage groups, such as D1a, M, A2, K, and G. The genes corresponding to QTL regions can explain 6%?38.5% genetic variation of sulfur-containing amino acids, and among them, the indirect effect values of 9 genes were more than 10%. These 12 genes were involved in sulfur-containing amino acid metabolism and were highly expressed in the cotyledons and flowers, showing an abundance of SNPs. These genes can be used as candidate genes for the development of functional markers, and it will lay a foundation for molecular design breeding in soybean.

  17. Incorporating Sulfur Inside the Pores of Carbons for Advanced Lithium-Sulfur Batteries: An Electrolysis Approach.

    Science.gov (United States)

    He, Bin; Li, Wen-Cui; Yang, Chao; Wang, Si-Qiong; Lu, An-Hui

    2016-01-26

    We have developed an electrolysis approach that allows effective and uniform incorporation of sulfur inside the micropores of carbon nanosheets for advanced lithium-sulfur batteries. The sulfur-carbon hybrid can be prepared with a 70 wt % sulfur loading, in which no nonconductive sulfur agglomerations are formed. Because the incorporated sulfur is electrically connected to the carbon matrix in nature, the hybrid cathode shows excellent electrochemical performance, including a high reversible capacity, good rate capability, and good cycling stability, as compared to one prepared using the popular melt-diffusion method.

  18. Sulfur globule oxidation in green sulfur bacteria is dependent on the dissimilatory sulfite reductase system

    DEFF Research Database (Denmark)

    Holkenbrink, Carina; Ocón Barbas, Santiago; Mellerup, Anders;

    2011-01-01

    Green sulfur bacteria oxidize sulfide and thiosulfate to sulfate with extracellular globules of elemental sulfur as intermediate. Here we investigated which genes are involved in the formation and consumption of these sulfur globules in the green sulfur bacterium Chlorobaculum tepidum. We show...... that sulfur globule oxidation is strictly dependent on the dissimilatory sulfite reductase (DSR) system. Deletion of dsrM/CT2244 or dsrT/CT2245 or the two dsrCABL clusters (CT0851-CT0854, CT2247-2250) abolished sulfur globule oxidation and prevented formation of sulfate from sulfide, whereas deletion of dsr...

  19. HYBRID SULFUR RECOVERY PROCESS FOR NATURAL GAS UPGRADING

    Energy Technology Data Exchange (ETDEWEB)

    Girish Srinivas; Steven C. Gebhard; David W. DeBerry

    2002-07-01

    This second quarter report of 2002 describes progress on a project funded by the U.S. Department of Energy (DOE) to test a hybrid sulfur recovery process for natural gas upgrading. The process concept represents a low cost option for direct treatment of natural gas streams to remove H{sub 2}S in quantities equivalent to 0.2-25 metric tons (LT) of sulfur per day. This process is projected to have lower capital and operating costs than the competing technologies, amine/aqueous iron liquid redox and amine/Claus/tail gas treating, and have a smaller plant footprint, making it well suited to both on-shore and offshore applications. CrystaSulf (service mark of CrystaTech, Inc.) is a new nonaqueous sulfur recovery process that removes hydrogen sulfide (H{sub 2}S) from gas streams and converts it into elemental sulfur. CrystaSulf features high sulfur recovery similar to aqueous-iron liquid redox sulfur recovery processes, but differs from the aqueous processes in that CrystaSulf controls the location where elemental sulfur particles are formed. In the hybrid process, approximately 1/3 of the total H{sub 2}S in the natural gas is first oxidized to SO{sub 2} at low temperatures over a heterogeneous catalyst. Low temperature oxidation is done so that the H{sub 2}S can be oxidized in the presence of methane and other hydrocarbons without oxidation of the hydrocarbons. The project involves the development of a catalyst using laboratory/bench-scale catalyst testing, and then demonstration of the catalyst at CrystaTech's pilot plant in west Texas. Previous reports described development of a catalyst with the required selectivity and efficiency for producing sulfur dioxide from H{sub 2}S. In the laboratory, the catalyst was shown to be robust and stable in the presence of several intentionally added contaminants, including condensate from the pilot plant site. This report describes testing using the laboratory apparatus but operated at the pilot plant using the actual pilot

  20. Evaluation of integrated impact of sulfur and Thiobacillus on qualitative and morphological characteristics of safflower (CarthamustinctoriusL.

    Directory of Open Access Journals (Sweden)

    F.S. Noorbakhsh

    2016-05-01

    Full Text Available Considering high alkalinity of Iranian soils and lack of availability of some nutrients in those conditions, sulfur consumption is one approach to increase the availability of insoluble nutrients especially in calcareous and alkaline soils. Effectiveness of sulfur depends on activity of sulfur oxidizing bacteria especially Thiobacillus genus (T. In order to study the qualitative yield and morphological characteristics of safflower (Carthamustinctorius L., a field experiment was carried out as factorial layout based on a randomized complete block design with three replications at the Agricultural Research Station, College of Agriculture, Birjand University during growing season 2010-2011. Treatments were including four sulfur levels (0, 300, 400 and 500 kg.ha-1 and four levels of Thiobacillus (0, 1, 2 and 3 kg.ha-1 per 100 kg.ha-1 organic sulfur. Studied traits were height and diameter of stems and qualitative characteristics of safflower such as protein and oil contents in seed and sulfur and phosphorus concentrations in leaf. Results showed that the effect of sulfur and biosulfur with Thiobacillusas a biofertilizer and their interaction effects were significant (p≤0.01 on oil and protein contents of seed, phosphorus and sulfur concentrations of leaf, and also on height and stem diameter of safflower. The highest seed protein content was observed in 500 kg.ha-1sulfur with 20.4% and the lowest was for control plots with 17.1%. The minimum oil content was recorded in control plots (18.7% and the highest improvement compared to control was obtained in 500 kg.ha-1sulfur with 26%. The highest height and stem diameter of safflower were observed in 400 and 500 kg.ha-1sulfur with 3 kg.ha-1Thiobacillus. So, it seems that integrated application of sulfur with Thiobacillus inoculation is an ecological strategy for improving of qualitative and quantitative growth and producing of oil crops such as safflower.

  1. Radiolysis of Sulfuric Acid, Sulfuric Acid Monohydrate, and Sulfuric Acid Tetrahydrate and Its Relevance to Europa

    Science.gov (United States)

    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.

  2. Studies of rechargeable lithium-sulfur batteries

    Science.gov (United States)

    Cui, Yi

    The studies of rechargeable lithium-sulfur (Li-S) batteries are included in this thesis. In the first part of this thesis, a linear sweep voltammetry method to study polysulfide transport through separators is presented. Shuttle of polysulfide from the sulfur cathode to lithium metal anode in rechargeable Li-S batteries is a critical issue hindering cycling efficiency and life. Several approaches have been developed to minimize it including polysulfide-blocking separators; there is a need for measuring polysulfide transport through separators. We have developed a linear sweep voltammetry method to measure the anodic (oxidization) current of polysulfides crossed separators, which can be used as a quantitative measurement of the polysulfide transport through separators. The electrochemical oxidation of polysulfide is diffusion controlled. The electrical charge in Coulombs produced by the oxidation of polysulfide is linearly related to the concentration of polysulfide within a certain range (≤ 0.5 M). Separators with a high porosity (large pore size) show high anodic currents, resulting in fast capacity degradation and low Coulombic efficiencies in Li-S cells. These results demonstrate this method can be used to correlate the polysulfide transport through separators with the separator structure and battery performance, therefore provide guidance for developing new separators for Li-S batteries. The second part includes a study on improving cycling performance of Li/polysulfide batteries by applying a functional polymer on carbon current collector. Significant capacity decay over cycling in Li-S batteries is a major impediment for their practical applications. Polysulfides Li2S x (3 life. We have examined a polyvinylpyrrolidone-modified carbon paper (CP-PVP) current collector in Li/polysulfide cells. PVP is soluble in the electrolyte solvent, but shows strong affinity with lithium polysulfides. The retention of polysulfides in the CP-PVP current collector is improved

  3. RNA-Seq Analysis of Sulfur-Deprived Chlamydomonas Cells Reveals Aspects of Acclimation Critical for Cell Survival[W

    Science.gov (United States)

    González-Ballester, David; Casero, David; Cokus, Shawn; Pellegrini, Matteo; Merchant, Sabeeha S.; Grossman, Arthur R.

    2010-01-01

    The Chlamydomonas reinhardtii transcriptome was characterized from nutrient-replete and sulfur-depleted wild-type and snrk2.1 mutant cells. This mutant is null for the regulatory Ser-Thr kinase SNRK2.1, which is required for acclimation of the alga to sulfur deprivation. The transcriptome analyses used microarray hybridization and RNA-seq technology. Quantitative RT-PCR evaluation of the results obtained by these techniques showed that RNA-seq reports a larger dynamic range of expression levels than do microarray hybridizations. Transcripts responsive to sulfur deprivation included those encoding proteins involved in sulfur acquisition and assimilation, synthesis of sulfur-containing metabolites, Cys degradation, and sulfur recycling. Furthermore, we noted potential modifications of cellular structures during sulfur deprivation, including the cell wall and complexes associated with the photosynthetic apparatus. Moreover, the data suggest that sulfur-deprived cells accumulate proteins with fewer sulfur-containing amino acids. Most of the sulfur deprivation responses are controlled by the SNRK2.1 protein kinase. The snrk2.1 mutant exhibits a set of unique responses during both sulfur-replete and sulfur-depleted conditions that are not observed in wild-type cells; the inability of this mutant to acclimate to S deprivation probably leads to elevated levels of singlet oxygen and severe oxidative stress, which ultimately causes cell death. The transcriptome results for wild-type and mutant cells strongly suggest the occurrence of massive changes in cellular physiology and metabolism as cells become depleted for sulfur and reveal aspects of acclimation that are likely critical for cell survival. PMID:20587772

  4. Cytochromes and iron sulfur proteins in sulfur metabolism of phototrophic bacteria

    Science.gov (United States)

    Fischer, U.

    1985-01-01

    Dissimilatory sulfur metabolism in phototrophic sulfur bacteria provides the bacteria with electrons for photosynthetic electron transport chain and, with energy. Assimilatory sulfate reduction is necessary for the biosynthesis of sulfur-containing cell components. Sulfide, thiosulfate, and elemental sulfur are the sulfur compounds most commonly used by phototrophic bacteria as electron donors for anoxygenic photosynthesis. Cytochromes or other electron transfer proteins, like high-potential-iron-sulfur protein (HIPIP) function as electron acceptors or donors for most enzymatic steps during the oxidation pathways of sulfide or thiosulfate. Yet, heme- or siroheme-containing proteins themselves undergo enzymatic activities in sulfur metabolism. Sirohemes comprise a porphyrin-like prosthetic group of sulfate reductase. eenzymatic reactions involve electron transfer. Electron donors or acceptors are necessary for each reaction. Cytochromes and iron sulfur problems, are able to transfer electrons.

  5. HYDROCARBON AND SULFUR SENSORS FOR SOFC SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Physiology of Haloalkaliphilic Sulfur-oxidizing Bacteria

    OpenAIRE

    Banciu, H.L.

    2004-01-01

    The inorganic sulfur oxidation by obligate haloalkaliphilic chemolithoautotrophs was only recently discovered and investigated. These autotrophic sulfur oxidizing bacteria (SOB), capable of oxidation of inorganic sulfur compounds at moderate to high salt concentration and at high pH, can be divided into three genera belonging to the γ subdivision of the Proteobacteria: Thioalkalimicrobium, Thioalkalivibrio and Thioalkalispira. Their taxonomy, metabolic diversity and the potential application...

  7. Characterization of sulfur oxidizing bacteria related to biogenic sulfuric acid corrosion in sludge digesters

    OpenAIRE

    Huber, Bettina;Herzog, Bastian;Drewes, Jörg E.;Koch, Konrad;Müller, Elisabeth

    2017-01-01

    Background Biogenic sulfuric acid (BSA) corrosion damages sewerage and wastewater treatment facilities but is not well investigated in sludge digesters. Sulfur/sulfide oxidizing bacteria (SOB) oxidize sulfur compounds to sulfuric acid, inducing BSA corrosion. To obtain more information on BSA corrosion in sludge digesters, microbial communities from six different, BSA-damaged, digesters were analyzed using culture dependent methods and subsequent polymerase chain reaction denaturing gradient ...

  8. Active microbial sulfur disproportionation in the Mesoproterozoic.

    Science.gov (United States)

    Johnston, David T; Wing, Boswell A; Farquhar, James; Kaufman, Alan J; Strauss, Harald; Lyons, Timothy W; Kah, Linda C; Canfield, Donald E

    2005-12-02

    The environmental expression of sulfur compound disproportionation has been placed between 640 and 1050 million years ago (Ma) and linked to increases in atmospheric oxygen. These arguments have their basis in temporal changes in the magnitude of 34S/32S fractionations between sulfate and sulfide. Here, we present a Proterozoic seawater sulfate isotope record that includes the less abundant sulfur isotope 33S. These measurements imply that sulfur compound disproportionation was an active part of the sulfur cycle by 1300 Ma and that progressive Earth surface oxygenation may have characterized the Mesoproterozoic.

  9. Graphene-wrapped sulfur nanospheres with ultra-high sulfur loading for high energy density lithium-sulfur batteries

    Science.gov (United States)

    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.

  10. Graphene-wrapped sulfur nanospheres with ultra-high sulfur loading for high energy density lithium–sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ya; Guo, Jinxin; Zhang, Jun, E-mail: zhangjun@zjnu.cn; Su, Qingmei; Du, Gaohui, E-mail: gaohuidu@zjnu.edu.cn

    2015-01-01

    Graphical abstract: - Highlights: • A graphene-wrapped sulfur nanospheres composite with 91 wt% S is prepared. • It shows highly improved electrochemical performance as cathode for Li–S cell. • The PVP coating and conductive graphene minimize polysulfides dissolution. • The flexible coatings with void space accommodate the volume expansion of sulfur. - Abstract: 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{sup −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.

  11. Sulfur-carbon nanocomposites and their application as cathode materials in lithium-sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Chengdu; Dudney, Nancy J.; Howe, Jane Y.

    2017-08-01

    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.

  12. HYBRID SULFUR RECOVERY PROCESS FOR NATURAL GAS UPGRADING

    Energy Technology Data Exchange (ETDEWEB)

    Girish Srinivas; Steven C. Gebhard; David W. DeBerry

    2002-04-01

    This first quarter report of 2002 describes progress on a project funded by the U.S. Department of Energy (DOE) to test a hybrid sulfur recovery process for natural gas upgrading. The process concept represents a low cost option for direct treatment of natural gas streams to remove H{sub 2}S in quantities equivalent to 0.2-25 metric tons (LT) of sulfur per day. This process is projected to have lower capital and operating costs than the competing technologies, amine/aqueous iron liquid redox and amine/Claus/tail gas treating, and have a smaller plant footprint, making it well suited to both on-shore and offshore applications. CrystaSulf{sup SM} (service mark of CrystaTech, Inc.) is a new nonaqueous sulfur recovery process that removes hydrogen sulfide (H{sub 2}S) from gas streams and converts it into elemental sulfur. CrystaSulf features high sulfur recovery similar to aqueous-iron liquid redox sulfur recovery processes, but differs from the aqueous processes in that CrystaSulf controls the location where elemental sulfur particles are formed. In the hybrid process, approximately 1/3 of the total H{sub 2}S in the natural gas is first oxidized to SO{sub 2} at low temperatures over a heterogeneous catalyst. Low temperature oxidation is done so that the H{sub 2}S can be oxidized in the presence of methane and other hydrocarbons without oxidation of the hydrocarbons. The project involves the development of a catalyst using laboratory/bench-scale catalyst testing, and then demonstration of the catalyst at CrystaTech's pilot plant in west Texas. In a previous reporting period tests were done to determine the effect of hydrocarbons such as n-hexane on catalyst performance with and without H{sub 2}S present. The experiments showed that hexane oxidation is suppressed when H{sub 2}S is present. Hexane represents the most reactive of the C1 to C6 series of alkanes. Since hexane exhibits low reactivity under H{sub 2}S oxidation conditions, and more importantly, does not

  13. Sulfur emission from Victorian brown coal under pyrolysis, oxy-fuel combustion and gasification conditions.

    Science.gov (United States)

    Chen, Luguang; Bhattacharya, Sankar

    2013-02-05

    Sulfur emission from a Victorian brown coal was quantitatively determined through controlled experiments in a continuously fed drop-tube furnace under three different atmospheres: pyrolysis, oxy-fuel combustion, and carbon dioxide gasification conditions. The species measured were H(2)S, SO(2), COS, CS(2), and more importantly SO(3). The temperature (873-1273 K) and gas environment effects on the sulfur species emission were investigated. The effect of residence time on the emission of those species was also assessed under oxy-fuel condition. The emission of the sulfur species depended on the reaction environment. H(2)S, SO(2), and CS(2) are the major species during pyrolysis, oxy-fuel, and gasification. Up to 10% of coal sulfur was found to be converted to SO(3) under oxy-fuel combustion, whereas SO(3) was undetectable during pyrolysis and gasification. The trend of the experimental results was qualitatively matched by thermodynamic predictions. The residence time had little effect on the release of those species. The release of sulfur oxides, in particular both SO(2) and SO(3), is considerably high during oxy-fuel combustion even though the sulfur content in Morwell coal is only 0.80%. Therefore, for Morwell coal utilization during oxy-fuel combustion, additional sulfur removal, or polishing systems will be required in order to avoid corrosion in the boiler and in the CO(2) separation units of the CO(2) capture systems.

  14. Sulfur Reduction in Acid Rock Drainage Environments

    NARCIS (Netherlands)

    Florentino, A.P.; Weijma, J.; Stams, A.J.M.; Sanchez Andrea, I.

    2015-01-01

    Microbiological suitability of acidophilic sulfur reduction for metal recovery was explored by enriching sulfur reducers from acidic sediments at low pH (from 2 to 5) with hydrogen, glycerol, methanol and acetate as electron donors at 30°C. The highest levels of sulfide in the enrichments were detec

  15. Ambient Air Monitoring for Sulfur Compounds

    Science.gov (United States)

    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)

  16. Comparative Genomics of Green Sulfur Bacteria

    DEFF Research Database (Denmark)

    Ussery, David; Davenport, C; Tümmler, B

    2010-01-01

    Eleven completely sequenced Chlorobi genomes were compared in oligonucleotide usage, gene contents, and synteny. The green sulfur bacteria (GSB) are equipped with a core genome that sustains their anoxygenic phototrophic lifestyle by photosynthesis, sulfur oxidation, and CO(2) fixation. Whole...... weight of 10(6), and are probably instrumental for the bacteria to generate their own intimate (micro)environment....

  17. Heterogeneous photocatalytic reactions of sulfur aromatic compounds.

    Science.gov (United States)

    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.

  18. Sulfur Reduction in Acid Rock Drainage Environments

    NARCIS (Netherlands)

    Florentino, A.P.; Weijma, J.; Stams, A.J.M.; Sanchez Andrea, I.

    2015-01-01

    Microbiological suitability of acidophilic sulfur reduction for metal recovery was explored by enriching sulfur reducers from acidic sediments at low pH (from 2 to 5) with hydrogen, glycerol, methanol and acetate as electron donors at 30°C. The highest levels of sulfide in the enrichments were detec

  19. Halophilic and haloalkaliphilic sulfur-oxidizing bacteria

    NARCIS (Netherlands)

    Sorokin, D.Y.; Banciu, H.; Robertson, L.A.; Kuenen, J.G.; Muntyan, M.S.; Muyzer, G.; Rosenberg, E.; DeLong, F.; Delong, E.; Lory, S.; Stackebrandt, E.; Thompson, F.

    2013-01-01

    Chemotrophic sulfur-oxidizing bacteria (SOB) represent an important functional group of microorganisms responsible for the dark oxidation of reduced sulfur compounds generated by sulfidogens. Until recently, only a single genus of halophilic SOB (Halothiobacillus) has been described, and nothing was

  20. Halophilic and haloalkaliphilic sulfur-oxidizing bacteria

    NARCIS (Netherlands)

    Sorokin, D.Y.; Banciu, H.; Robertson, L.A.; Kuenen, J.G.; Muntyan, M.S.; Muyzer, G.; Rosenberg, E.; DeLong, F.; Delong, E.; Lory, S.; Stackebrandt, E.; Thompson, F.

    2013-01-01

    Chemotrophic sulfur-oxidizing bacteria (SOB) represent an important functional group of microorganisms responsible for the dark oxidation of reduced sulfur compounds generated by sulfidogens. Until recently, only a single genus of halophilic SOB (Halothiobacillus) has been described, and nothing was

  1. The adsorption of sulfur by microporous materials

    NARCIS (Netherlands)

    Steijns, M.; Mars, P.

    1976-01-01

    The sorption of sulfur by the zeolites NaX (= 13X) and CaA (= 5A) and an activated charcoal prepared from sugar was investigated at temperatures between 150 and 350°C and relative sulfur pressures between 10−4 and 10−1. The adsorbate-adsorbate interaction indicated by the S-shaped isotherm for the z

  2. Economic comparison of hydrogen production using sulfuric acid electrolysis and sulfur cycle water decomposition. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Farbman, G.H.; Krasicki, B.R.; Hardman, C.C.; Lin, S.S.; Parker, G.H.

    1978-06-01

    An evaluation of the relative economics of hydrogen production using two advanced techniques was performed. The hydrogen production systems considered were the Westinghouse Sulfur Cycle Water Decomposition System and a water electrolysis system employing a sulfuric acid electrolyte. The former is a hybrid system in which hydrogen is produced in an electrolyzer which uses sulfur dioxide to depolarize the anode. The electrolyte is sulfuric acid. Development and demonstration efforts have shown that extremely low cell voltages can be achieved. The second system uses a similar sulfuric acid electrolyte technology in water electrolysis cells. The comparative technoeconomics of hydrogen produced by the hybrid Sulfur Cycle and by water electrolysis using a sulfuric acid electrolyte were determined by assessing the performance and economics of 380 million SCFD plants, each energized by a very high temperature nuclear reactor (VHTR). The evaluation concluded that the overall efficiencies of hydrogen production, for operating parameters that appear reasonable for both systems, are approximately 41% for the sulfuric acid electrolysis and 47% for the hybrid Sulfur Cycle. The economic evaluation of hydrogen production, based on a 1976 cost basis and assuming a developed technology for both hydrogen production systems and the VHTRs, indicated that the hybrid Sulfur Cycle could generate hydrogen for a total cost approximately 6 to 7% less than the cost from the sulfuric acid electrolysis plant.

  3. Effect of Addition of Allium hookeri on the Quality of Fermented Sausage with Meat from Sulfur Fed Pigs during Ripening.

    Science.gov (United States)

    Song, Eun-Yeong; Pyun, Chang-Won; Hong, Go-Eun; Lim, Ki-Won; Lee, Chi-Ho

    2014-01-01

    The effect of the addition of Allium hookeri on the quality of fermented sausage made with meat from sulfur fed pigs was examined, throughout a 60 d ripening period. There were two treatments in animal management: normal feed fed pigs, and sulfur fed pigs given 0.3% sulfur mixed normal feed. Fermented sausage manufactured with meat from normal feed fed pigs, and with meat from sulfur fed pigs, and 1% A. hookeri-containing fermented sausage processed with meat from sulfur fed pigs, were determined at 1 d, 15 d, 30 d, and 60 d. The meat qualities in fermented sausage were measured by DPPH radical scavenging activity (DPPH), ABTS(+) radical scavenging activity (ABTS(+)), total phenolic acids, and total flavonoid contents. Fermented sausage made from pigs that had been fed with 0.3% sulfur was protected from oxidation by reduced free radical, as shown by the significant increase in DPPH and ABTS(+) values, compared with fermented sausage made from normal feed fed pigs (psausage with sulfur fed pork was shown to increase the values in DPPH, ABTS(+), total phenolic acid, and total flavonoid contents, by comparison with both the control sausage, and sausage with sulfur fed pork, at 60 d. These results suggest that A. hookeri in meat from sulfur fed pigs could be a source of natural addition, to increase quality in the food industry.

  4. Effect of Additive on Sulfur-fixation Process of Sulfur-fixation Agent

    Institute of Scientific and Technical Information of China (English)

    XIE Jun-lin; QIU Jian-rong; ZHAO Gai-ju; LOU Jin-ping; HAN Chun-hua

    2003-01-01

    The crystallization behavior of desulfurization product is directly related to its high-temperatureresistant ability. Effects of the additive on the sulfur-fixation efficiency of the Ba-sulfur-fixation agent and also on the crystallization behavior of the sulfur-fixation product were studied when CaCO3 and BaCO3 were used as the desulfurization agent and MgO and SrCO3 used as the assistant sulfur-fixation agent. The result shows that increase of sulfur-fixation capability for the additive is not owe to their directly react to form sulfate or interact with CaCO3 and BaCO3 to form composite mineral heat-resistant in high temperature, but owe to their activation to sulfur-fixation reaction of the sulfur-fixation agent.

  5. A low-cost, sulfurization free approach to control optical and electronic properties of Cu2ZnSnS4 via precursor variation

    OpenAIRE

    Gupta, Saatviki; Whittles, Thomas J.; Batra, Yogita; Satsangi, Vibha; Krishnamurthy, Satheesh; Dhanak, Vinod R.; Mehta, Bodh Raj

    2016-01-01

    Thin films of Cu2ZnSnS4 (CZTS) were synthesized via a low cost, wet chemical technique of chemical bath deposition (CBD). In the first part of this study, the chemical composition ratio S/(Cu+Zn+Sn) was varied keeping Cu/(Zn + Sn) and Zn/Sn ratios constant to study the effect of sulfur variation. Detailed electrical and optical characterization has been carried out using UV-visible spectroscopy, x-ray diffraction, x-ray photoelectron spectroscopy, Raman spectroscopy and Kelvin probe force mic...

  6. Steep spatial gradients of volcanic and marine sulfur in Hawaiian rainfall and ecosystems

    Science.gov (United States)

    Bern, Carleton R.; Chadwick, Oliver A.; Kendall, Carol; Pribil, Michael J.

    2015-01-01

    Sulfur, a nutrient required by terrestrial ecosystems, is likely to be regulated by atmospheric processes in well-drained, upland settings because of its low concentration in most bedrock and generally poor retention by inorganic reactions within soils. Environmental controls on sulfur sources in unpolluted ecosystems have seldom been investigated in detail, even though the possibility of sulfur limiting primary production is much greater where atmospheric deposition of anthropogenic sulfur is low. Here we measure sulfur isotopic compositions of soils, vegetation and bulk atmospheric deposition from the Hawaiian Islands for the purpose of tracing sources of ecosystem sulfur. Hawaiian lava has a mantle-derived sulfur isotopic composition (δ34S VCDT) of − 0.8‰. Bulk deposition on the island of Maui had a δ34S VCDT that varied temporally, spanned a range from + 8.2 to + 19.7‰, and reflected isotopic mixing from three sources: sea-salt (+ 21.1‰), marine biogenic emissions (+ 15.6‰), and volcanic emissions from active vents on Kilauea Volcano (+ 0.8‰). A straightforward, weathering-driven transition in ecosystem sulfur sources could be interpreted in the shift from relatively low (0.0 to + 2.7‰) to relatively high (+ 17.8 to + 19.3‰) soil δ34S values along a 0.3 to 4100 ka soil age-gradient, and similar patterns in associated vegetation. However, sub-kilometer scale spatial variation in soil sulfur isotopic composition was found along soil transects assumed by age and mass balance to be dominated by atmospheric sulfur inputs. Soil sulfur isotopic compositions ranged from + 8.1 to + 20.3‰ and generally decreased with increasing elevation (0–2000 m), distance from the coast (0–12 km), and annual rainfall (180–5000 mm). Such trends reflect the spatial variation in marine versus volcanic inputs from atmospheric deposition. Broadly, these results illustrate how the sources and magnitude of atmospheric deposition can exert controls

  7. New progresses in safe, clean and efficient development technologies for high-sulfur gas reservoirs

    Directory of Open Access Journals (Sweden)

    Liming Huang

    2015-10-01

    Full Text Available In China, there are a lot of high-sulfur gas reservoirs with total proved reserves of over 1 trillion m3, most of which were discovered in the Sichuan Basin. Most high-sulfur gas reservoirs in China, distributed in marine carbonate zones, are characterized by great buried depths, complex geologic conditions, high temperatures, high pressures, high H2S and CO2 content, presenting various challenges in gas field development engineering and production safety. Since the development of Sinian high-sulfur gas reservoirs in the Weiyuan area of the Sichuan Basin started in the 1960s, Wolonghe, Zhongba and other medium to small-scale gas reservoirs with medium to low sulfur content have been developed. Ever since 2009, successful production of Longgang and Puguang in the Sichuan Basin, together with some other high-sulfur gas reservoirs highlighted the breakthroughs in development technologies for high-sulfur gas reservoirs in China. This paper reviews the progress made in gas reservoir engineering, drilling and completion engineering, gas production, pipeline transportation, corrosion control, natural gas purification, HSE and other aspects with consideration of specific requirements related to safe, clean and high-efficient development of high-sulfur gas reservoirs since the “12th Five-Year Plan” period. Finally, considering the challenges in the development of high-sulfur gas reservoirs in China, we summarized the trend in future technological development with the following goals of reducing risks, minimizing environmental damages, and enhancing the efficiency of high-sulfur gas reservoir development.

  8. Toward Understanding the Effect of Low-Activity Waste Glass Composition on Sulfur Solubility

    Energy Technology Data Exchange (ETDEWEB)

    Vienna, John D.; Kim, Dong-Sang; Muller, Isabelle S.; Piepel, Gregory F.; Kruger, Albert A.

    2014-10-01

    The concentration of sulfur in nuclear waste glass melter feed must be maintained below the point where salt accumulates on the melt surface. The allowable concentrations may range from 0.37 to over 2.05 weight percent (of SO3 on a calcined oxide basis). If the amount of sulfur exceeds its tolerance level a molten salt will accumulate and upset melter operations and potentially shorten melter useful life. Therefore relatively conservative limits have been placed on sulfur loading in melter feed which in-turn significantly impacts the amount of glass that will be produced, in particular at the Hanford site. Crucible-scale sulfur solubility data and scaled melter sulfur tolerance data have been collected on simulated Hanford waste glasses over the last 15 years. These data were compiled and analyzed. A model was developed to predict the solubility of SO3 in glass based on 312 individual glass compositions. This model was shown to well represent the data, accounting for over 80% of the variation in data and was well validated. The model was also found to accurately predict the tolerance for sulfur in melter feed based on 19 scaled melter tests. The model is appropriate for control of waste glass processing which includes uncertainty quantification. The model also gives quantitative estimates of component concentration effects on sulfur solubility. The components that most increase sulfur solubility are Li2O > V2O5 ≈ TiO2 < CaO < P2O5 ≈ ZnO. The components that most decrease sulfur solubility are Cl > Cr2O3 > SiO2 ≈ ZrO2 > Al2O3.

  9. Influence of sulfur and cadmium on antioxidants, phytochelatins and growth in Indian mustard.

    Science.gov (United States)

    Bashir, Humayra; Ibrahim, Mohamed M; Bagheri, Rita; Ahmad, Javed; Arif, Ibrahim A; Baig, M Affan; Qureshi, M Irfan

    2015-01-12

    Soils in many parts of the world are contaminated with heavy metals, leading to multiple, deleterious effects on plants and threats to world food production efficiency. Cadmium (Cd) is one such metal, being toxic at relatively low concentrations as it is readily absorbed and translocated in plants. Sulfur-rich compounds are critical to the impact of Cd toxicity, enabling plants to increase their cellular defence and/or sequester Cd into vacuoles mediated by phytochelatins (PCs). The influence of sulfur on Cd-induced stress was studied in the hyperaccumulator plant Indian mustard (Brassica juncea) using two sulfur concentrations (+S, 300 µM [Formula: see text] and S-deficient -S, [Formula: see text]) with and without the addition of Cd (100 µM CdCl2) at two different time intervals (7 and 14 days after treatment). Compared with control plants (+S/-Cd), levels of oxidative stress were higher in S-deficient (-S/-Cd) plants, and greatest in S-deficient Cd-treated (-S/+Cd) plants. However, additional S (+S/+Cd) helped plants cope with oxidative stress. Superoxide dismutase emerged as a key player against Cd stress under both -S and +S conditions. The activity of ascorbate peroxidase, glutathione reductase and catalase declined in Cd-treated and S-deficient plants, but was up-regulated in the presence of sulfur. Sulfur deficiency mediated a decrease in ascorbate and glutathione (GSH) content but changes in ascorbate (reduced : oxidized) and GSH (reduced : oxidized) ratios were alleviated by sulfur. Our data clearly indicate that a sulfur pool is needed for synthesis of GSH, non-protein thiols and PCs and is also important for growth. Sulfur-based defence mechanisms and the cellular antioxidant pathway, which are critical for tolerance and growth, collapsed as a result of a decline in the sulfur pool.

  10. Differential response to sulfur nutrition of two common bean genotypes differing in storage protein composition

    Directory of Open Access Journals (Sweden)

    Sudhakar ePandurangan

    2015-02-01

    Full Text Available It has been hypothesized that the relatively low concentration of sulfur amino acids in legume seeds might be an ecological adaptation to nutrient poor, marginal soils. SARC1 and SMARC1N-PN1 are genetically related lines of common bean (dry bean, Phaseolus vulgaris differing in seed storage protein composition. In SMARC1N-PN1, the lack of phaseolin and major lectins is compensated by increased levels of sulfur-rich proteins, resulting in an enhanced concentration of cysteine and methionine, mostly at the expense of the abundant non-protein amino acid, S-methylcysteine. To identify potential effects associated with an increased concentration of sulfur amino acids in the protein pool, the response of the two genotypes to low and high sulfur nutrition was evaluated under controlled conditions. Seed yield was increased by the high sulfate treatment in SMARC1N-PN1. The seed concentrations of sulfur, sulfate and S-methylcysteine were altered by the sulfur treatment in both genotypes. The concentration of total cysteine and extractible globulins was increased specifically in SMARC1N-PN1. Proteomic analysis identified arcelin-like protein 4, lipoxygenase-3, albumin-2 and alpha amylase inhibitor beta chain as having increased levels under high sulfur conditions. Lipoxygenase-3 accumulation was sensitive to sulfur nutrition only in SMARC1N-PN1. Under field conditions, both SARC1 and SMARC1N-PN1 exhibited a slight increase in yield in response to sulfur treatment, typical for common bean.

  11. Simultaneous determinations of sulfur and heat content of coal: revitalization of a traditional physical chemistry experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, M.R.; McCorkle, K.L. (Rose-Hulman Institute of Technology, Terre Haute, IN (United States))

    1994-02-01

    In the experiment, the student is asked to measure the sulfur and heat content of a coal sample of approximately 1-5% sulfur by mass. The sulfur content refers to the sulfur that is free to form sulfur oxides upon combustion and any sulfate forms already present in the coal such as CaSO[sub 4].2H[sub 2]O (gypsum). Sulfates are, however, typically less than 1% of the total amount of sulfur present in coal (datum obtained from the Illinois State Geological Survey) which will have a negligible effect on the results obtained. Since the composition of coal is dependent on the original flora and geological processes from which it was formed, there is no set value for the combustible sulfur content or heat value in the literature. This type of measurement is performed by industrial chemists for coal burning industries, such as in electric generation, in compliance with local and federal sulfur oxide emission controls, and hence increases a student's sense of accomplishment. The technique used by these chemists is specified by the American Society for Testing and Materials published under ASTM Designations D3176-89(3) and D3177-89(4). Though the ASTM technique is a more accurate analysis, the proposed experiment is more amenable to an undergraduate laboratory. The method described is both an accurate and convenient means of simultaneously determining the heat and combustible sulfur content of coal. This experiment can be utilized in the physical and environmental chemistry laboratory. 9 refs., 2 tabs.

  12. Sulfur nanocrystals anchored graphene composite with highly improved electrochemical performance for lithium-sulfur batteries

    Science.gov (United States)

    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.

  13. Kinetic elements in thermophilic-microbial leaching of sulfur from coal. [Sulfolobus acidocaldarius

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C.C.Y.; Skidmore, D.R.

    1988-01-01

    A mechanism found suitable for pyritic sulfur removal from coal by mesophilic organisms has been modified and evaluated for the same reaction by the thermophile: Sulfolobus acidocaldarius. The mechanism as modified includes direct and indirect mechanistic elements whose magnitudes were determined experimentally at leaching conditions with and without microbes. Chemical leaching of pyrite by Fe(III) ions and the chemical oxidation of Fe(II) to Fe(III) were found to contribute significantly to overall conversions at thermophilic temperature (72/degree/C) but not at mesophilic temperature (25-37/degree/C). The model thus constructed fit overall sulfur leaching data well after suitable assumptions had been made for extent of cell attachment; gas (oxygen) transfer rates, sulfur accessibility, and sulfate reprecipitation rates. The resulting equation is useful for process simulation, control and design. Further work is needed to define additional sulfur leaching effects.

  14. Effects of sulfur fertilization on the accumulation of health-promoting phytochemicals in radish sprouts.

    Science.gov (United States)

    Zhou, Chenguang; Zhu, Yi; Luo, Yunbo

    2013-08-07

    The effects of sulfur fertilization on the growth profile, the contents of glucosinolates, anthocyanins, vitamin C, carotenoids, chlorophylls, total phenolics, and the FRAP value in radish seeds and sprouts were investigated. The concentrations of glucosinolates and antioxidants in sprouts were strongly influenced by the process of germination. Sulfur fertilization induced significant increases in the contents of individual glucosinolates, carotenoids, chlorophylls, and total phenolics. The phenolic contents in sprouts cultivated using 20, 60, or 100 mg/L sulfate were 20.7%, 40.4%, and 40.8% higher, respectively, than those of 7-day-old control sprouts. No detectable effects were observed on the contents of 4-methoxy-glucobrassicin and vitamin C. In addition, the accumulation of anthocyanins in 7-day-old sprouts decreased by 14.8-39.3% upon sulfur fertilization. These findings indicated that the application of sulfur fertilization has the potential to enhance the levels of health-promoting compounds in radish sprouts.

  15. Analysis of Operational Parameters Affecting the Sulfur Content in Hot Metal of the COREX Process

    Science.gov (United States)

    Wu, Shengli; Wang, Laixin; Kou, Mingyin; Wang, Yujue; Zhang, Jiacong

    2017-02-01

    The COREX process, which has obvious advantages in environment protection, still has some disadvantages. It has a higher sulfur content in hot metal (HM) than the blast furnace has. In the present work, the distribution and transfer of sulfur in the COREX have been analyzed and several operational parameters related to the sulfur content in HM ([pct S]) have been obtained. Based on this, the effects of the coal rate, slag ratio, temperature of HM, melting rate, binary basicity ( R 2), the ratio of MgO/Al2O3, utilization of reducing gas, top gas consumption per ton burden solid, metallization rate, oxidation degree of reducing gas, and coal and DRI distribution index on the sulfur content in HM are investigated. What's more, a linear model has been developed and subsequently used for predicting and controlling the S content in HM of the COREX process.

  16. Air pollution and asthma: clinical studies with sulfuric acid aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Utell, M.J.; Frampton, M.W.; Morrow, P.E. (University of Rochester School of Medicine and Dentistry, NY (United States))

    1991-11-01

    Until recently, acid deposition has been widely considered a serious ecological problem but not a threat to human health. The controlled clinical study is an important approach in linking acidic aerosol inhalation with respiratory effects. Asthmatic patients represent a subpopulation most responsive to sulfuric acid aerosols. In a series of studies with asthmatic volunteers, several factors have been identified that may modulate the intensity of the bronchoconstrictor response to inhaled acidic aerosols. We found (1) enhancement of the bronchoconstrictor response during exercise, (2) the more acidic aerosols provoke the greatest changes in lung function, and (3) mitigation of airway responses during sulfuric acid aerosol inhalation caused by high respiratory ammonia concentrations. Additional factors influencing responsiveness await identification.

  17. HYBRID SULFUR RECOVERY PROCESS FOR NATURAL GAS UPGRADING

    Energy Technology Data Exchange (ETDEWEB)

    Dennis Dalrymple

    2004-06-01

    This final report describes the objectives, technical approach, results and conclusions for a project funded by the U.S. Department of Energy to test a hybrid sulfur recovery process for natural gas upgrading. The process concept is a configuration of CrystaTech, Inc.'s CrystaSulf{reg_sign} process which utilizes a direct oxidation catalyst upstream of the absorber tower to oxidize a portion of the inlet hydrogen sulfide (H{sub 2}S) to sulfur dioxide (SO{sub 2}) and elemental sulfur. This hybrid configuration of CrystaSulf has been named CrystaSulf-DO and represents a low-cost option for direct treatment of natural gas streams to remove H{sub 2}S in quantities equivalent to 0.2-25 metric tons (LT) of sulfur per day and more. This hybrid process is projected to have lower capital and operating costs than the competing technologies, amine/aqueous iron liquid redox and amine/Claus/tail gas treating, and have a smaller plant footprint, making it well suited to both onshore and offshore applications. CrystaSulf is a nonaqueous sulfur recovery process that removes H{sub 2}S from gas streams and converts it to elemental sulfur. In CrystaSulf, H{sub 2}S in the inlet gas is reacted with SO{sub 2} to make elemental sulfur according to the liquid phase Claus reaction: 2H{sub 2}S + SO{sub 2} {yields} 2H{sub 2}O + 3S. The SO{sub 2} for the reaction can be supplied from external sources by purchasing liquid SO{sub 2} and injecting it into the CrystaSulf solution, or produced internally by converting a portion of the inlet gas H{sub 2}S to SO{sub 2} or by burning a portion of the sulfur produced to make SO{sub 2}. CrystaSulf features high sulfur recovery similar to aqueous-iron liquid redox sulfur recovery processes, but differs from the aqueous processes in that CrystaSulf controls the location where elemental sulfur particles are formed. In the hybrid process, the needed SO{sub 2} is produced by placing a bed of direct oxidation catalyst in the inlet gas stream to oxidize

  18. Natural variations of copper and sulfur stable isotopes in blood of hepatocellular carcinoma patients

    Science.gov (United States)

    Balter, Vincent; Nogueira da Costa, Andre; Paky Bondanese, Victor; Jaouen, Klervia; Lamboux, Aline; Sangrajrang, Suleeporn; Vincent, Nicolas; Fourel, François; Télouk, Philippe; Gigou, Michelle; Lécuyer, Christophe; Srivatanakul, Petcharin; Bréchot, Christian; Albarède, Francis; Hainaut, Pierre

    2015-01-01

    The widespread hypoxic conditions of the tumor microenvironment can impair the metabolism of bioessential elements such as copper and sulfur, notably by changing their redox state and, as a consequence, their ability to bind specific molecules. Because competing redox state is known to drive isotopic fractionation, we have used here the stable isotope compositions of copper (65Cu/63Cu) and sulfur (34S/32S) in the blood of patients with hepatocellular carcinoma (HCC) as a tool to explore the cancer-driven copper and sulfur imbalances. We report that copper is 63Cu-enriched by ∼0.4‰ and sulfur is 32S-enriched by ∼1.5‰ in the blood of patients compared with that of control subjects. As expected, HCC patients have more copper in red blood cells and serum compared with control subjects. However, the isotopic signature of this blood extra copper burden is not in favor of a dietary origin but rather suggests a reallocation in the body of copper bound to cysteine-rich proteins such as metallothioneins. The magnitude of the sulfur isotope effect is similar in red blood cells and serum of HCC patients, implying that sulfur fractionation is systemic. The 32S-enrichment of sulfur in the blood of HCC patients is compatible with the notion that sulfur partly originates from tumor-derived sulfides. The measurement of natural variations of stable isotope compositions, using techniques developed in the field of Earth sciences, can provide new means to detect and quantify cancer metabolic changes and provide insights into underlying mechanisms.

  19. Natural variations of copper and sulfur stable isotopes in blood of hepatocellular carcinoma patients.

    Science.gov (United States)

    Balter, Vincent; Nogueira da Costa, Andre; Bondanese, Victor Paky; Jaouen, Klervia; Lamboux, Aline; Sangrajrang, Suleeporn; Vincent, Nicolas; Fourel, François; Télouk, Philippe; Gigou, Michelle; Lécuyer, Christophe; Srivatanakul, Petcharin; Bréchot, Christian; Albarède, Francis; Hainaut, Pierre

    2015-01-27

    The widespread hypoxic conditions of the tumor microenvironment can impair the metabolism of bioessential elements such as copper and sulfur, notably by changing their redox state and, as a consequence, their ability to bind specific molecules. Because competing redox state is known to drive isotopic fractionation, we have used here the stable isotope compositions of copper ((65)Cu/(63)Cu) and sulfur ((34)S/(32)S) in the blood of patients with hepatocellular carcinoma (HCC) as a tool to explore the cancer-driven copper and sulfur imbalances. We report that copper is (63)Cu-enriched by ∼0.4‰ and sulfur is (32)S-enriched by ∼1.5‰ in the blood of patients compared with that of control subjects. As expected, HCC patients have more copper in red blood cells and serum compared with control subjects. However, the isotopic signature of this blood extra copper burden is not in favor of a dietary origin but rather suggests a reallocation in the body of copper bound to cysteine-rich proteins such as metallothioneins. The magnitude of the sulfur isotope effect is similar in red blood cells and serum of HCC patients, implying that sulfur fractionation is systemic. The (32)S-enrichment of sulfur in the blood of HCC patients is compatible with the notion that sulfur partly originates from tumor-derived sulfides. The measurement of natural variations of stable isotope compositions, using techniques developed in the field of Earth sciences, can provide new means to detect and quantify cancer metabolic changes and provide insights into underlying mechanisms.

  20. A Carbon-Sulfur Hybrid with Pomegranate-like Structure for Lithium-Sulfur Batteries.

    Science.gov (United States)

    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.

  1. Amylopectin wrapped graphene oxide/sulfur for improved cyclability of lithium-sulfur battery.

    Science.gov (United States)

    Zhou, Weidong; Chen, Hao; Yu, Yingchao; Wang, Deli; Cui, Zhiming; Disalvo, Francis J; Abruña, Héctor D

    2013-10-22

    An amylopectin wrapped graphene oxide-sulfur composite was prepared to construct a 3-dimensionally cross-linked structure through the interaction between amylopectin and graphene oxide, for stabilizing lithium sulfur batteries. With the help of this cross-linked structure, the sulfur particles could be confined much better among the layers of graphene oxide and exhibited significantly improved cyclability, compared with the unwrapped graphene oxide-sulfur composite. The effect of the electrode mass loading on electrochemical performance was investigated as well. In the lower sulfur mass loading cells, such as 2 mg cm(-2), both the capacity and the efficiency were obviously better than those of the higher sulfur mass loading cells, such as 6 mg cm(-2).

  2. Graphene oxide as a sulfur immobilizer in high performance lithium/sulfur cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yuegang; Cairns, Elton J.; Ji, Liwen; Rao, Mumin

    2017-06-06

    The loss of sulfur cathode material as a result of polysulfide dissolution causes significant capacity fading in rechargeable lithium/sulfur cells. Embodiments of the invention use a chemical approach to immobilize sulfur and lithium polysulfides via the reactive functional groups on graphene oxide. This approach obtains a uniform and thin (.about.tens of nanometers) sulfur coating on graphene oxide sheets by a chemical reaction-deposition strategy and a subsequent low temperature thermal treatment process. Strong interaction between graphene oxide and sulfur or polysulfides demonstrate lithium/sulfur cells with a high reversible capacity of 950-1400 mAh g.sup.-1, and stable cycling for more than 50 deep cycles at 0.1 C.

  3. Sulfur Isotopic Characteristics of Coal in China and Sulfur Isotopic Fractionation during Coal—burning Process

    Institute of Scientific and Technical Information of China (English)

    洪业汤; 张鸿斌; 等

    1993-01-01

    The determined results of the sulfur contents and isotopic composition of coal samples from major coal mines in 15 provinces and regions of China show that the coal mined in the north of China is characterized by higher 34S and lower sulfur content, but that in the south of China has lower 34S and higher sulfur content.During the coal-burning process in both indrstrial and daily use of coal as fuel the released sulfur dioxide is always enriched in lighter sulfur isotope relative to the corresponding coal;the particles are always enriched in heavier sulfur isotope.The discussion on the environmental geochemical significance of the above-mentioned results also has been made.

  4. Improvements in the manufacture of sulfur from hydrogen sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Azoulay, A.

    1968-12-23

    In this process for the manufacture of sulfur from hydrogen sulfide and sulfur dioxide, the sulfur is separated from the gas after reaction by direct contact by cooling with a cooling liquid. The sulfur is carried away by the cooling liquid.

  5. 硫膜和树脂膜控释尿素对小麦产量、品质及氮素利用率的影响%Effects of sulfur-and polymer-coated controlled release urea fertilizers on wheat yield and quality and fertilizer nitrogen use efficiency

    Institute of Scientific and Technical Information of China (English)

    马富亮; 宋付朋; 高杨; 邹朋

    2012-01-01

    通过田间试验,研究了硫膜和树脂膜控释尿素对小麦产量、品质和耕层土壤无机氮含量及氮素利用率的影响.结果表明:与普通尿素相比,硫膜和树脂膜控释尿素均能显著提高小麦籽粒产量和品质,增产幅度达10.4%~16.5%,小麦籽粒蛋白质和淀粉含量分别提高5.8%~18.9%和0.3%~1.4%;两种控释肥均能有效保持耕层土壤无机氮含量,且其氮素后移的功效满足了小麦生育后期对氮素的需求;有效提高了氮肥偏生产力,降低了土壤氮素依存率(降幅11.0% ~17.3%),提高了氮素利用率(增幅58.2%~101.2%).其中,树脂膜控释尿素比硫膜控释尿素表现出更好的增产效应,实现了氮素的高效利用.%A field experiment was conducted to study the effects of sulfur- and polymer-coated controlled release urea fertilizers on wheat yield and its quality, plow layer soil inorganic nitrogen (N) contents, and fertilizer N use efficiency. Compared with traditional urea fertilizer, both sulfur- and polymer-coated controlled release urea fertilizers increased the grain yield by 10.4% -16. 5% , and the grain protein and starch contents by 5. 8% -18. 9% and 0. 3% -1. 4% , respectively. The controlled release urea fertilizers could maintain the topsoil inorganic N contents to meet the N requirement for the wheat, especially during its late growth stage. In the meantime, the fertilizer N use efficiency was improved by 58. 2% —101. 2% . Polymer-coated urea produced better wheat yield and higher fertilizer N use efficiency, compared with sulfur-coated controlled release urea.

  6. Mass-independent sulfur of inclusions in diamond and sulfur recycling on early Earth.

    Science.gov (United States)

    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.

  7. Analysis of sulfur in deposited aerosols by thermal decomposition and sulfur dioxide analyzer.

    Science.gov (United States)

    Yamamoto, Masatoshi

    2005-07-15

    A thermal decomposition method that measures aerosol sulfur at the nanogram level directly from the collection substrate is described. A thermal decomposition apparatus was designed. A stainless steel strip was used as the aerosol collection substrate. A 0.1 mol/L MnCl2 solution was added as the thermal decomposition catalyst. Currents were passed through the strip where aerosol particles had been deposited. In this way, the strip was heated at 780 +/- 10 degrees C, and particulate sulfur was evaporated. A sulfur dioxide analyzer (SDA) with flame photometric detector (FPD) was used to detect gaseous sulfur. High sulfur recoveries from (NH4)2SO4 and other inorganic sulfates, such as NH4HSO4, K2SO4, MgSO4, and CaSO4, were obtained. From the sulfur blank and the calibration, a lower limited detection of 0.2 ng of sulfur and the determination range of 3.3-167 ng of sulfur were estimated. The method is effective for measuring the sulfate size distributions of urban aerosols in a small sample air volume of 50-60 L. The method is applicable to measuring the sulfur in aqueous extracts of size-segregated urban aerosols collected by impactor and comparing the results with the sulfate data measured by ion chromatography.

  8. Mechanisms and evolution of oxidative sulfur metabolism in green sulfur bacteria

    DEFF Research Database (Denmark)

    Gregersen, Lea Haarup; Bryant, Donald A.; Frigaard, Niels-Ulrik

    2011-01-01

    Green sulfur bacteria (GSB) constitute a closely related group of photoautotrophic and thiotrophic bacteria with limited phenotypic variation. They typically oxidize sulfide and thiosulfate to sulfate with sulfur globules as an intermediate. Based on genome sequence information from 15 strains......, the distribution and phylogeny of enzymes involved in their oxidative sulfur metabolism was investigated. At least one homolog of sulfide:quinone oxidoreductase (SQR) is present in all strains. In all sulfur-oxidizing GSB strains except the earliest diverging Chloroherpeton thalassium, the sulfide oxidation...... and SOX systems. Finally, based upon structural, biochemical, and phylogenetic analyses, a uniform nomenclature is suggested for sqr genes in prokaryotes....

  9. Sulfur-centered reactive intermediates derived from the oxidation of sulfur compounds of biological interest

    Energy Technology Data Exchange (ETDEWEB)

    Abedinzadeh, Z. [Lab. de Chimie Physique, UMR, Univ. Rene Descartes, Paris (France)

    2001-02-01

    Sulphur compounds play a central role in the structure and activity of many vital systems. In the living cell, sulfur constitutes an essential part of the defense against oxidative damage and is transformed into a variety of sulfur free radical species. Many studies of the chemistry of sulfur-centered radicals using pulse radiolysis and photolysis techniques to detect and measure the kinetics of these radicals have been published and reviewed. This paper discusses the present state of research on the formation and reactivity of certain sulfur-centered radicals [RS{sup .}, RSS{sup .}, RS{sup .+}, (RSSR){sup .+}] and their implications for biological systems. (author)

  10. Linking neutral and charged sulfuric acid-ammonia and sulfuric acid-dimethylamine clusters

    Science.gov (United States)

    Ortega, Ismael K.; Kupiainen, Oona; Olenius, Tinja; Loukonen, Ville; Kurtén, Theo; Vehkamäki, Hanna

    2013-05-01

    We have used a quantum chemical method to calculate the formation free energies of negatively charged sulfuric acid - ammonia and sulfuric acid - dimethylamine clusters. Using the calculated formation free energies we have estimated the evaporation rates of the clusters. We have compared the evaporation rate of the charged clusters with the corresponding neutral clusters. We found that, although small clusters of sulfuric acid with ammonia and dimethylamine are stable and should be present in the atmosphere, they can not be detected using mass spectroscopy techniques. Charging the cluster will result in the fast evaporation of the base molecules, and they will be detected as pure sulfuric acid cluster.

  11. Dual protection of sulfur by carbon nanospheres and graphene sheets for lithium-sulfur batteries.

    Science.gov (United States)

    Wang, Bei; Wen, Yanfen; Ye, Delai; Yu, Hua; Sun, Bing; Wang, Guoxiu; Hulicova-Jurcakova, Denisa; Wang, Lianzhou

    2014-04-25

    Well-confined elemental sulfur was implanted into a stacked block of carbon nanospheres and graphene sheets through a simple solution process to create a new type of composite cathode material for lithium-sulfur batteries. Transmission electron microscopy and elemental mapping analysis confirm that the as-prepared composite material consists of graphene-wrapped carbon nanospheres with sulfur uniformly distributed in between, where the carbon nanospheres act as the sulfur carriers. With this structural design, the graphene contributes to direct coverage of sulfur to inhibit the mobility of polysulfides, whereas the carbon nanospheres undertake the role of carrying the sulfur into the carbon network. This composite achieves a high loading of sulfur (64.2 wt %) and gives a stable electrochemical performance with a maximum discharge capacity of 1394 mAh g(-1) at a current rate of 0.1 C as well as excellent rate capability at 1 C and 2 C. The improved electrochemical properties of this composite material are attributed to the dual functions of the carbon components, which effectively restrain the sulfur inside the carbon nano-network for use in lithium-sulfur rechargeable batteries.

  12. Corrosion pathways in liquid sulfur run-down pits and other liquid sulfur handling facilities

    Energy Technology Data Exchange (ETDEWEB)

    Clark, P.D.; Dowling, N.I.; Huang, M.

    2010-01-15

    This poster presentation explained why sulfur pits deteriorate over time and provided the detailed chemistry of the mechanisms for the deterioration of concrete in sulfur pits. Liquid and solid sulfur may build up in the pore structure of the concrete, which is followed by chemical reactions. The sulfur formation inside the concrete pore structure is catalyzed by concrete constituents. The sulfate formation in sulfur pit concrete was described. The chemical process that produces the corrosion of re-enforcing steel rods used in the construction of sulfur pits was also described. The consequence of such corrosion is the loss of structural integrity. The secondary corrosion processes at concrete pit reinforcing steel were also presented. To limit the deterioration of sulfur pit concrete, high-density silica facing should be used on the concrete to prevent the ingress of gases into the concrete. Silica does not catalyze the conversion of hydrogen disulfide and sulfur dioxide to sulfur, so there is no formation of stable sulfates and acidic intermediates. 8 figs.

  13. Protected Sulfur Cathode with Mixed Conductive Coating Layer for Lithium Sulfur Battery

    Science.gov (United States)

    Jin, Jun; Wen, Zhaoyin; Wang, Qingsong; Gu, Sui; Huang, Xiao; Chen, Chunhua

    2016-10-01

    A mixed conductive coating layer composed of lithium ion conductive ceramic powder, carbon and binder was introduced on the surface of a sulfur electrode. This coating layer is designed to suppress the migration of lithium polysulfides from the sulfur electrode, and improve the cycling capacity of a lithium sulfur battery. The protected sulfur cathode with a mixed conductive coating layer delivered an initial specific capacity of 1236 mAh g-1 at 0.5C and maintained a capacity of 842 mAh g-1 after 100 cycles. In particular, a soft package battery with protected cathode exhibits improved cycling capacity and excellent rate performance.

  14. Mesoporous hollow carbon spheres for lithium–sulfur batteries: distribution of sulfur and electrochemical performance

    Directory of Open Access Journals (Sweden)

    Anika C. Juhl

    2016-08-01

    Full Text Available Hollow carbon spheres (HCS with a nanoporous shell are promising for the use in lithium–sulfur batteries because of the large internal void offering space for sulfur and polysulfide storage and confinement. However, there is an ongoing discussion whether the cavity is accessible for sulfur. Yet no valid proof of cavity filling has been presented, mostly due to application of unsuitable high-vacuum methods for the analysis of sulfur distribution. Here we describe the distribution of sulfur in hollow carbon spheres by powder X-ray diffraction and Raman spectroscopy along with results from scanning electron microscopy and nitrogen physisorption. The results of these methods lead to the conclusion that the cavity is not accessible for sulfur infiltration. Nevertheless, HCS/sulfur composite cathodes with areal sulfur loadings of 2.0 mg·cm−2 were investigated electrochemically, showing stable cycling performance with specific capacities of about 500 mAh·g−1 based on the mass of sulfur over 500 cycles.

  15. ROE Total Sulfur Deposition 1989-1991

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset identifies the amount of wet, dry, and total deposition of sulfur in kilograms per hectare from 1989 to 1991 at a set of point locations across the...

  16. ROE Total Sulfur Deposition 2011-2013

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset identifies the amount of wet, dry, and total deposition of sulfur in kilograms per hectare from 2011 to 2013 at a set of point locations across the...

  17. Environmental behavior and analysis of agricultural sulfur.

    Science.gov (United States)

    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.

  18. Atmospheric influence of Earth's earliest sulfur cycle

    Science.gov (United States)

    Farquhar; Bao; Thiemens

    2000-08-01

    Mass-independent isotopic signatures for delta(33)S, delta(34)S, and delta(36)S from sulfide and sulfate in Precambrian rocks indicate that a change occurred in the sulfur cycle between 2090 and 2450 million years ago (Ma). Before 2450 Ma, the cycle was influenced by gas-phase atmospheric reactions. These atmospheric reactions also played a role in determining the oxidation state of sulfur, implying that atmospheric oxygen partial pressures were low and that the roles of oxidative weathering and of microbial oxidation and reduction of sulfur were minimal. Atmospheric fractionation processes should be considered in the use of sulfur isotopes to study the onset and consequences of microbial fractionation processes in Earth's early history.

  19. Efficient Electrolytes for Lithium-Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    Natarajan eAngulakshmi

    2015-05-01

    Full Text Available This review article mainly encompasses on the state-of-the-art electrolytes for lithium–sulfur batteries. Different strategies have been employed to address the issues of lithium-sulfur batteries across the world. One among them is identification of electrolytes and optimization of their properties for the applications in lithium-sulfur batteries. The electrolytes for lithium-sulfur batteries are broadly classified as (i non-aqueous liquid electrolytes, (ii ionic liquids, (iii solid polymer and (iv glass-ceramic electrolytes. This article presents the properties, advantages and limitations of each type of electrolytes. Also the importance of electrolyte additives on the electrochemical performance of Li-S cells is discussed.

  20. Fluid-melt partitioning of sulfur in differentiated arc magmas and the sulfur yield of explosive volcanic eruptions

    Science.gov (United States)

    Masotta, M.; Keppler, H.; Chaudhari, A.

    2016-03-01

    The fluid-melt partitioning of sulfur (DSfluid/melt) in differentiated arc magmas has been experimentally investigated under oxidizing conditions (Re-ReO2 buffer) from 800 to 950 °C at 200 MPa. The starting glasses ranged in composition from trachyte to rhyolite and were synthesized targeting the composition of the residual melt formed after 10-60% crystallization of originally trachy-andesitic, dacitic and rhyodacitic magmas (Masotta and Keppler, 2015). Fluid compositions were determined both by mass balance and by Raman spectroscopy of fluid inclusions. DSfluid/melt increases exponentially with increasing melt differentiation, ranging from 2 to 15 in the trachytic melt, from 20 to 100 in the dacitic and rhyodacitic melts and from 100 to 120 in the rhyolitic melt. The variation of the DSfluid/melt is entirely controlled by the compositional variation of the silicate melt, with temperature having at most a minor effect within the range investigated. Experiments from this study were used together with data from the literature to calibrate the following model that allows predicting DSfluid/melt for oxidized arc magmas: where nbo/t is the non-bridging oxygen atoms per tetrahedron, ASI is the alumina saturation index, Al# and Ca# are two empirical compositional parameters calculated in molar units (Al # = XAl2O3/XSiO2 +XTiO2 +XAl2O3 and Ca # = XCaO/XNa2O +XK2O). The interplay between fluid-melt partitioning and anhydrite solubility determines the sulfur distribution among anhydrite, melt and fluid. At increasing melt polymerization, the exponential increase of the partition coefficient and the decrease of anhydrite solubility favor the accumulation of sulfur either in the fluid phase or as anhydrite. On the other hand, the higher anhydrite solubility and lower partition coefficient for less polymerized melts favor the retention of sulfur in the melt. At equilibrium conditions, these effects yield a maximum of the sulfur fraction in the fluid phase for slightly

  1. Amine reactivity with charged sulfuric acid clusters

    OpenAIRE

    Bzdek, B. R.; D. P. Ridge; Johnston, M. V.

    2011-01-01

    The distribution of ionic species produced by electrospray of an ammonium sulfate solution in both positive and negative polarities is examined using Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). Positively-charged ammonium bisulfate cluster composition differs significantly from negatively-charged cluster composition. For positively-charged clusters all sulfuric acid is neutralized to bisulfate, whereas for negatively-charged clusters the degree of sulfuric acid neu...

  2. Amine reactivity with charged sulfuric acid clusters

    OpenAIRE

    Bzdek, B. R.; D. P. Ridge; Johnston, M. V.

    2011-01-01

    The distribution of charged species produced by electrospray of an ammonium sulfate solution in both positive and negative polarities is examined using Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). Positively-charged ammonium bisulfate cluster composition differs significantly from negatively-charged cluster composition. For positively-charged clusters all sulfuric acid is neutralized to bisulfate, whereas for negatively-charged clusters the degree of sulfuric acid n...

  3. A Cable-Shaped Lithium Sulfur Battery.

    Science.gov (United States)

    Fang, Xin; Weng, Wei; Ren, Jing; Peng, Huisheng

    2016-01-20

    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.

  4. Biologically produced sulfur particles and polysulfide ions

    OpenAIRE

    Kleinjan, W. E.

    2005-01-01

    This thesis deals with the effects of particles of biologically produced sulfur (or 'biosulfur') on a biotechnological process for the removal of hydrogen sulfide from gas streams. Particular emphasis is given to the role of polysulfide ions in such a process. These polysulfide ions are formed from reaction of sulfide with biologically produced sulfur. The basic concepts of this H 2 S removal process were developed at the department of Environmental Technology of Wageningen University and the...

  5. Attachment of Thiobacillus thiooxidans to sulfur crystals.

    Science.gov (United States)

    SCHAEFFER, W I; HOLBERT, P E; UMBREIT, W W

    1963-01-01

    Schaeffer, W. I. (Rutgers, The State University, New Brunswick, N.J.), P. E. Holbert, and W. W. Umbreit. Attachment of Thiobacillus thiooxidans to sulfur crystals. J. Bacteriol. 85:137-140. 1963.-Electron micrographs of replicas of sulfur crystals before and after attack by Thiobacillus thiooxidans show that the microorganisms erode the crystal in the area immediately adjacent to the cell. When there are many cells, the entire crystal surface appears eroded.

  6. Polymer Electrolytes for Lithium/Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    The Nam Long Doan

    2012-08-01

    Full Text Available This review evaluates the characteristics and advantages of employing polymer electrolytes in lithium/sulfur (Li/S batteries. The main highlights of this study constitute detailed information on the advanced developments for solid polymer electrolytes and gel polymer electrolytes, used in the lithium/sulfur battery. This includes an in-depth analysis conducted on the preparation and electrochemical characteristics of the Li/S batteries based on these polymer electrolytes.

  7. Mixed Population Screening for Sulfur Isotopes

    Institute of Scientific and Technical Information of China (English)

    CUI Bin; ZHAO Lei; ZHAN Zhaoyang; HE Zhijun

    2004-01-01

    Quantitative research of the origin of sulfur isotopes is a difficult problem that has puzzled geochemists all along. In the study of the middle and lower reaches of the Yangtze River and the Dongpo orefield in Hunan Province,the authors successfully applied the mathematical model of mixed population screening to quantitatively resolving the problem on the origin of sulfur isotopes, which is significant in finding out the source of mineralizing matter and metallogenic mechanisms.

  8. Sulfur chemistry in a copper smelter plume

    Science.gov (United States)

    Eatough, D. J.; Christensen, J. J.; Eatough, N. I.; Hill, M. W.; Major, T. D.; Mangelson, N. F.; Post, M. E.; Ryder, J. F.; Hansen, L. D.; Meisenheimer, R. G.; Fischer, J. W.

    Sulfur transformation chemistry was studied in the plume of the Utah smelter of Kennecott Copper Corporation from April to October 1977. Samples were taken at up to four locations from 4 to 60 km from the stacks. Data collected at each station included: SO 2 concentration, low-volume collected total paniculate matter, high-volume collected size fractionated paniculate matter, wind velocity and direction, temperature, and relative humidity. Paniculate samples were analyzed for S(IV). sulfate, strong acid, anions, cations, and elemental concentrations using calorimetric, ion Chromatographie, FIXE, ESCA, ion microprobe, and SEM-ion microprobe techniques. The concentration of As in the paniculate matter was used as a conservative plume tracer. The ratios Mo/As, Pb/As, and Zn/As were constant in particulate matter collected at all sampling sites for any particle size. Strong mineral acid was neutralized by background metal oxide and/or carbonate particulates within 40km of the smelter. This neutralization process is limited only by the rate of incorporation of basic material into the plume. Two distinct metal-S(IV) species similar to those observed in laboratory aerosol experiments were found in the plume. The formation of paniculate S(IV) species occurs by interaction of SO 2 (g) with both ambient and plume derived aerosol and is equilibrium controlled. The extent of formation of S(IV) complexes in the aerosol is directly proportional to the SO 2(g) and paniculate (Cu + Fe) concentration and inversely proportional to the paniculate acidity. S(IV) species were stable in collected paniculate matter only in the neutralized material, but with proper sampling techniques could be demonstrated to also be present in very acidic particles at high ambient SO 2(g) concentrations. Reduction of arsenate to arsenite by the aerosol S(IV) complexes during plume transport is suggested. The SO 2(g)-sulfate conversion process in the plume is described by a mechanism which is first order

  9. Ocular Effects of Sulfur Mustard

    Directory of Open Access Journals (Sweden)

    Yunes Panahi

    2013-06-01

    Full Text Available Purpose: To review current knowledge about ocular effects of sulfur mustard (SM and the associated histopathologic findings and clinical manifestationsMethods: Literature review of medical articles (human and animal studies was accomplished using PubMed, Scopus and ISI databases. A total of 274 relevant articles in English were retrieved and reviewed thoroughly.Results: Eyes are the most sensitive organs to local toxic effects of mustard gas. Ocular injuries are mediated through different toxic mechanisms including: biochemical damages, biomolecular and gene expression modification, induction of immunologic and inflammatory reactions, disturbing ultrastructural architecture of the cornea, and long-lasting corneal denervation. The resulting ocular injuries can roughly be categorized into acute or chronic complications. Most of the patients recover from acute injuries, but a minority of victims will suffer from chronic ocular complications. Mustard gas keratopathy (MGK is a devastating late complication of SM intoxication that proceeds from limbal stem cell deficiency (LSCD.Conclusion: SM induces several different damaging changes in case of ocular exposure; hence leading to a broad spectrum of ocular manifestations in terms of severity, timing and form. Unfortunately, no effective strategy has been introduced yet to inhibit or restore these damaging changes.

  10. Sulfur nutrition of deciduous trees

    Science.gov (United States)

    Herschbach, Cornelia; Rennenberg, Heinz

    2001-01-01

    Sulfur in its reduced form (-II) is an essential nutrient for growth and development, but is mainly available to plants in its oxidised form as sulfate. Deciduous trees take up sulfate by the roots from the soil solution and reduce sulfate to sulfide via assimilatory sulfate reduction in both roots and leaves. For reduction in the leaves, sulfate is loaded into the xylem and transported to the shoot. The surplus of sulfate not reduced in the chloroplast or stored in the vacuole and the surplus of reduced S not used for protein synthesis in the leaves is loaded into the phloem and transported back to the roots. Along the transport path, sulfate and glutathione (GSH) is unloaded from the phloem for storage in xylem and phloem parenchyma as well as in pit and ray cells. Re-mobilised S from storage tissues is loaded into the xylem during spring, but a phloem to xylem exchange does not appear to exist later in the season. As a consequence, a cycling pool of S was only found during the change of the seasons. The sulfate:glutathione ratio in the phloem seems to be involved in the regulation of S nutrition. This picture of S nutrition is discussed in relation to the different growth patterns of deciduous trees from the temperate climate zone, i.e. (1) terminated, (2) periodic and (3) indeterminate growth patterns, and in relation to environmental changes.

  11. An Aerosol Condensation Model for Sulfur Trioxide

    Energy Technology Data Exchange (ETDEWEB)

    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

  12. Genetic engineering of sulfur-degrading Sulfolobus

    Energy Technology Data Exchange (ETDEWEB)

    Ho, N.W.Y. (Purdue Univ., Lafayette, IN (USA). 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.

  13. Coralline algae as a globally significant pool of marine dimethylated sulfur

    Science.gov (United States)

    Burdett, Heidi L.; Hatton, Angela D.; Kamenos, Nicholas A.

    2015-10-01

    Marine algae are key sources of the biogenic sulfur compound dimethylsulphoniopropionate (DMSP), a vital component of the marine sulfur cycle. Autotrophic ecosystem engineers such as red coralline algae support highly diverse and biogeochemically active ecosystems and are known to be high DMSP producers, but their importance in the global marine sulfur cycle has not yet been appreciated. Using a global sampling approach, we show that red coralline algae are a globally significant pool of DMSP in the oceans, estimated to be ~110 × 1012 moles worldwide during the summer months. Latitude was a major driver of observed regional-scale variations, with peaks in polar and tropical climate regimes, reflecting the varied cellular functions for DMSP (e.g., as a cryoprotectant and antioxidant). A temperate coralline algal bed was investigated in more detail to also identify local-scale temporal variations. Here, water column DMSP was driven by water temperature, and to a lesser extent, cloud cover; two factors which are also vital in controlling coralline algal growth. This study demonstrates that coralline algae harbor a large pool of dimethylated sulfur, thereby playing a significant role in both the sulfur and carbon marine biogeochemical cycles. However, coralline algal habitats are severely threatened by projected climate change; a loss of this habitat may thus detrimentally impact oceanic sulfur and carbon biogeochemical cycling.

  14. Origin of electrolyte-dopant dependent sulfur poisoning of SOFC anodes.

    Science.gov (United States)

    Zeng, ZhenHua; Björketun, Mårten E; Ebbesen, Sune; Mogensen, Mogens B; Rossmeisl, Jan

    2013-05-14

    The mechanisms governing the sulfur poisoning of the triple phase boundary (TPB) of Ni-XSZ (X2O3 stabilized zirconia) anodes have been investigated using density functional theory. The calculated sulfur adsorption energies reveal a clear correlation between the size of the cation dopant X(3+) and the sulfur tolerance of the Ni-XSZ anode; the smaller the ionic radius, the higher the sulfur tolerance. The mechanistic study shows that the size of X(3+) strongly influences XSZ's surface energy, which in turn determines the adhesion of Ni to XSZ. The Ni-XSZ interaction has a direct impact on the Ni-S interaction and on the relative stability of reconstructed and pristine Ni(100) facets at the TPB. Together, these two effects control the sulfur adsorption on the Ni atoms at the TPB. The established relationships explain experimentally observed dopant-dependent anode performances and provide a blueprint for the future search for and preparation of highly sulfur tolerant anodes.

  15. Determination of total sulfur content of sedimentary rocks by a combustion method

    Science.gov (United States)

    Coller, M.E.; Leininger, R.K.

    1955-01-01

    Total sulfur has been determined in common sedimentary rocks by a combustion method. Sulfur contents range from 0.001 to 5.0%. Experiments show that the combustion method can be used in analyzing sedimentary rocks in which sulfur is present as sulfide, sulfate, or both. Pulverized samples from 0.100 to 0.500 gram in weight are used in this method. Each sample is placed in a No. 6 Leco combustion boat and covered with two fluxes: 0.50 gram of standard ingot iron and approximately 1.0 gram of 30-mesh granular tin. The boat with sample then is placed in the combustion tube of a Burrell Unit Package Model T29A tube furnace which is controlled at a temperature of 1310?? to 1320?? C. After the sample has been heated for 1 minute, oxygen is admitted at a rate of about 1 liter per minute. The sulfur dioxide formed is absorbed in a starch solution and is titrated with standard potassium iodate in a Leco sulfur determinator. Thirteen values obtained for National Bureau of Standards standard sample 1a, argillaceous limestone, range from 0.273 to 0.276% sulfur (certificate value 0.27% by calculation).

  16. Possible Decoupling of the Geochemical Cycles of Sulfur and Carbon During the Early Cretaceous (Hauterivian)

    Science.gov (United States)

    Kristall, B.; Hurtgen, M. T.; Sageman, B. B.

    2013-12-01

    During the past decade there has been significant focus on understanding the global sulfur cycle during the Mid- to Late-Cretaceous. The occurrence of several oceanic anoxic events (OAEs) during this time period and the relationships among the sulfur, carbon, and oxygen cycles controlling the redox state of the ocean have been motivating factors in this research. These efforts have centered on identifying what impact, if any, massive volcanism and evaporite deposition associated with opening of the South Atlantic had on the sulfate content of the ocean and what role these events may have played in triggering OAEs. However, relatively little work has been done to characterize the sulfur cycle during the Early Cretaceous. In the present study, we have analyzed the sulfur isotope composition of carbonate-associated sulfate (CAS) from Hauterivian-aged samples (Resolution Guyot ODP Hole 866A). We found a previously unrecognized ~4‰ positive sulfur isotope excursion in sulfate sulfur. This well structured, excursion spans approximately 15-20 m of core and is estimated to be less than 300-500 kyr. Corresponding carbonate carbon isotope analyses do not show a comparable, well-structured excursion. During this event δ13C values vary only by 0.25-0.5‰. The rapid shift and recovery in δ34Ssulfate suggests either that this event was regional or that the Early Cretaceous oceans contained low sulfate levels (factors necessary to produce the observed S isotope shift without a corresponding change in C isotope composition.

  17. Acid deposition critical loads modeling for the simulation of sulfur exceedance and reduction in Guangdong, China

    Institute of Scientific and Technical Information of China (English)

    QIU Rongliang; WANG Shizhong; QIU Hao; WANG Xuemei; LIAO Jin; ZHANG Zhentian

    2009-01-01

    In this study, the current acid deposition critical loads in Guangdong, China were calculated using the PROFILE model with a 3×3 km resolution.Calculations were carried out for critical loads of potential acidity, actual acidity, sulfur and nitrogen, with values in extents of 0-3.5, 0-14.0, 0-26.0 and 0-3.5 kmol/(hm2·year), respectively.These values were comparable to previously reported results and reflected the influences of vegetation and soil characteristics on the soil acid buffering capacity.Simulations of SO2 emission and sulfur deposition in this study showed that sulfur deposition core areas mirrored SO2 emission centers.The prediction of sulfur deposition after 20% and 40% reduction of SO2 emission suggested that the reduction of area sources contributed greatly to the decrease of sulfur deposition.Thus, abatement of area source emissions could be the primary way to mitigate sulfur deposition in Guangdong so as to meet both the provincial and national regulations of air pollution control.

  18. Influence of the sulfur species reactivity on biofilm conformation during pyrite colonization by Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Lara, René H; García-Meza, J Viridiana; Cruz, Roel; Valdez-Pérez, Donato; González, Ignacio

    2012-08-01

    Massive pyrite (FeS₂) electrodes were potentiostatically modified by means of variable oxidation pulse to induce formation of diverse surface sulfur species (S(n)²⁻, S⁰). The evolution of reactivity of the resulting surfaces considers transition from passive (e.g., Fe(1-x )S₂) to active sulfur species (e.g., Fe(1-x )S(2-y ), S⁰). Selected modified pyrite surfaces were incubated with cells of sulfur-oxidizing Acidithiobacillus thiooxidans for 24 h in a specific culture medium (pH 2). Abiotic control experiments were also performed to compare chemical and biological oxidation. After incubation, the attached cells density and their exopolysaccharides were analyzed by confocal laser scanning microscopy (CLMS) and atomic force microscopy (AFM) on bio-oxidized surfaces; additionally, S(n)²⁻/S⁰ speciation was carried out on bio-oxidized and abiotic pyrite surfaces using Raman spectroscopy. Our results indicate an important correlation between the evolution of S(n)²⁻/S⁰ surface species ratio and biofilm formation. Hence, pyrite surfaces with mainly passive-sulfur species were less colonized by A. thiooxidans as compared to surfaces with active sulfur species. These results provide knowledge that may contribute to establishing interfacial conditions that enhance or delay metal sulfide (MS) dissolution, as a function of the biofilm formed by sulfur-oxidizing bacteria.

  19. Acid deposition critical loads modeling for the simulation of sulfur exceedance and reduction in Guangdong, China.

    Science.gov (United States)

    Qiu, Rongliang; Wang, Shizhong; Qiu, Hao; Wang, Xuemei; Liao, Jin; Zhang, Zhentian

    2009-01-01

    The current acid deposition critical loads in Guangdong, China were calculated using the PROFILE model with a 3 km x 3 km resolution. Calculations were carried out for critical loads of potential acidity, actual acidity, sulfur and nitrogen, with values in extents of 0-3.5, 0-14.0, 0-26.0 and 0-3.5 kmol/(hm2 x year), respectively. These values were comparable to previously reported results and reflected the influences of vegetation and soil characteristics on the soil acid buffering capacity. Simulations of SO2 emission and sulfur deposition in this study showed that sulfur deposition core areas mirrored SO2 emission centers. The prediction of sulfur deposition after 20% and 40% reduction of SO2 emission suggested that the reduction of area sources contributed greatly to the decrease of sulfur deposition. Thus, abatement of area source emissions could be the primary way to mitigate sulfur deposition in Guangdong to meet both the provincial and national regulations of air pollution control.

  20. Tracing sources of sulfur in the Florida Everglades.

    Science.gov (United States)

    Bates, Anne L; Orem, William H; Harvey, Judson W; Spiker, Elliott C

    2002-01-01

    We examined concentrations and sulfur isotopic ratios (34S/32S, expressed as delta34S in parts per thousand [/1000] units) of sulfate in surface water, ground water, and rain water from sites throughout the northern Everglades to establish the sources of sulfur to the ecosystem. The geochemistry of sulfur is of particular interest in the Everglades because of its link, through processes mediated by sulfate-reducing bacteria, to the production of toxic methylmercury in this wetland ecosystem. Methylmercury, a neurotoxin that is bioaccumulated, has been found in high concentrations in freshwater fish from the Everglades, and poses a potential threat to fish-eating wildlife and to human health through fish consumption. Results show that surface water in large portions of the Everglades is heavily contaminated with sulfate, with the highest concentrations observed in canals and marsh areas receiving canal discharge. Spatial patterns in the range of concentrations and delta34S values of sulfate in surface water indicate that the major source of sulfate in sulfur-contaminated marshes is water from canals draining the Everglades Agricultural Area. Shallow ground water underlying the Everglades and rain water samples had much lower sulfate concentrations and delta34S values distinct from those found in surface water. The delta34S results implicate agricultural fertilizer as a major contributor to the sulfate contaminating the Everglades, but ground water under the Everglades Agricultural Area (EAA) may also be a contributing source. The contamination of the northern Everglades with sulfate from canal discharge may be a key factor in controlling the distribution and extent of methylmercury production in the Everglades.

  1. Microbial Sulfur Cycling in an Acid Mine Lake

    Science.gov (United States)

    Bernier, L.; Warren, L. A.

    2004-12-01

    Geochemical dynamics of a tailings impacted lake in Northern Ontario were investigated over a three-year period, in which active pyrrhotite slurry disposal was initiated in year two. A strong seasonal trend of decreasing epilimnetic pH with significant diurnal acid production, pre-, during and post slurry deposition was observed with high rates observed compared to pre-slurry. Slurry deposition occurred at the surface of the lake and acted as a reaction stimulant for acid generation. Over the diurnal timescale investigated, the highest rates of acid production occurred not at the lake surface but within the metaliminetic region of the lake. This region was exemplified by strong decreasing oxygen gradients, and thus observed high rates of acid generation are more consistent with microbial pathways of sulfur oxidation than with abiotic, oxygen catalyzed pathways. Consistent with microbial catalysis, metalimnetic rates of acid generation were highest during June and July when microbial populations and metabolic rates were maximal. These results indicate that microbial oxidation of sulfur species play a major role in acid generation in this system. Further, observed rates of acid generation exceed those predicted by published abiotic rates of pyrrhotite oxidation, but are consistent with literature estimates of acid generation catalyzed by microbial activity. Acidithiobacilli accounted for up to 50% of the microbial community pre slurry, but were absent post slurry deposition. These results are the first to demonstrate quantitatively that microbial sulfur oxidation can play a predominant role in acid generation within mine tailings impacted systems. They further highlight the need to evaluate the more complex pathways by which microorganisms process sulfur as the conditions, controls and process rates differ from those observed for abiotic reactions.

  2. Microphysical simulations of sulfur burdens from stratospheric sulfur geoengineering

    Directory of Open Access Journals (Sweden)

    J. M. English

    2012-01-01

    Full Text Available 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.

  3. Microphysical simulations of sulfur burdens from stratospheric sulfur geoengineering

    Directory of Open Access Journals (Sweden)

    J. M. English

    2012-05-01

    Full Text Available 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.

  4. Fully automatic apparatus for proximate analysis and total sulfur analysis of coal and coke

    Energy Technology Data Exchange (ETDEWEB)

    Ishibashi, Y.; Fukumoto, K.; Maeda, K.; Ogawa, A.; Goto, K.; Ishii, T.

    1987-02-01

    For the purpose of saving labor and improving working conditions, the full automatic apparatus for the proximate analysis and total sulfur analysis of coal and coke was developed. Objects of this automation were to quantify inherent moisture, ash, volatile matter and total sulfur. Quantitative determination of inherent moisture, ash and volatile matter was made gravimetrically. Total sulfur was measured by combustion and acid and base titration, using a conductivity glass electrode sensor. The robot was set to the center of the automatic apparatus and relevant apparatuses were arranged in concentric circular locations. The computer carried out condition control of each apparatus, sequence control by operating demand and operation completing signal, and progress control of analysis. Very high correlation between the conventional method and this automatic method was confirmed. 4 refs., 9 figs., 3 tabs.

  5. [Influence of exogenous sulfur-containing compounds on the exchange fluxes of volatile organic sulfur compounds].

    Science.gov (United States)

    Yi, Zhi-Gang; Wang, Xin-Ming

    2011-08-01

    The influences of cysteine, sodium sulfide (Na2S) and sodium sulfate (Na2SO4) on the soil-air exchange fluxes of volatile organic sulfur compounds (VOSCs), including carbonyl sulfide (COS), dimethyl sulfide (DMS), carbon disulfide (CS2) and dimethyl disulfide (DMDS), were studied employing static chamber enclosure followed by laboratory determination using an Entech 7100 preconcentrator coupled with an Agilent 5973 GC-MSD. The results showed that after the addition of cysteine, the soil for the exchange fluxes of COS and CS2 shifted to be the source from sink and the emissions of DMS and DMDS increased significant. The emission amount of DMS and CS2 accounted for 89.2% to the total VOSCs after the addition of cysteine, implying that cysteine is an important precursor for DMS and CS2 in the soil. The amount of DMDS accounted for 93.2% to the total sulfur from the soil after addition of Na2S, indicating that Na2S is a key precursor for DMDS. No significant difference of VOSCs fluxes was found between the controlled soil and the soil with addition of Na2SO4, suggesting Na2SO4 was not the direct precursor for VOSCs in soil. VOSCs exchange rates reached the maximum at 6 to 8 days after addition of cysteine. As for addition of Na2S, the maximal emission rates of different VOSCs appeared at different dates, and the dates differed significantly from those after addition of cysteine, implying that the formation process of VOSCs from the soil with addition of Na2S was more complex and different from the soil with addition of cysteine.

  6. Improvement of Energy Capacity with Vitamin C Treated Dual-Layered Graphene-Sulfur Cathodes in Lithium-Sulfur Batteries.

    Science.gov (United States)

    Kim, Jin Won; Ocon, Joey D; Kim, Ho-Sung; Lee, Jaeyoung

    2015-09-07

    A graphene-based cathode design for lithium-sulfur batteries (LSB) that shows excellent electrochemical performance is proposed. The dual-layered cathode is composed of a sulfur active layer and a polysulfide absorption layer, and both layers are based on vitamin C treated graphene oxide at various degrees of reduction. By controlling the degree of reduction of graphene, the dual-layered cathode can increase sulfur utilization dramatically owing to the uniform formation of nanosized sulfur particles, the chemical bonding of dissolved polysulfides on the oxygen-rich sulfur active layer, and the physisorption of free polysulfides on the absorption layer. This approach enables a LSB with a high specific capacity of over 600 mAh gsulfur (-1) after 100 cycles even under a high current rate of 1C (1675 mA gsulfur (-1) ). An intriguing aspect of our work is the synthesis of a high-performance dual-layered cathode by a green chemistry method, which could be a promising approach to LSBs with high energy and power densities.

  7. Fibrous hybrid of graphene and sulfur nanocrystals for high-performance lithium-sulfur batteries.

    Science.gov (United States)

    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.

  8. Paleoarchean sulfur cycling : Multiple sulfur isotope constraints from the Barberton Greenstone Belt, South Africa

    NARCIS (Netherlands)

    Montinaro, Alice; Strauss, Harald; Mason, Paul R D; Roerdink, Desiree; Münker, Carsten; Schwarz-Schampera, Ulrich; Arndt, Nicholas T.; Farquhar, James; Beukes, Nicolas J.; Gutzmer, Jens; Peters, Marc

    2015-01-01

    Mass-dependent and mass-independent sulfur isotope fractionation archived in volcanic and sedimentary rocks from the Barberton Greenstone Belt (3550-3215. Ma), South Africa, provide constraints for sulfur cycling on the early Earth. Four different sample suites were studied: komatiites and tholeiite

  9. Capital cost: high and low sulfur coal plants-1200 MWe. [For low sulfur coal

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    This Commercial Electric Power Cost Study for 1200 MWe (Nominal) high and low sulfur coal plants consists of three volumes. The high sulfur coal plant is described in Volumes I and II, while Volume III describes the low sulfur coal plant. The design basis and cost estimate for the 1232 MWe high sulfur coal plant is presented in Volume I, and the drawings, equipment list and site description are contained in Volume II. The reference design includes a lime flue gas desulfurization system. A regenerative sulfur dioxide removal system using magnesium oxide is also presented as an alternate in Section 7 V olume II. The design basis, drawings and summary cost estimate for a 1243 MWe low sulfur coal plant are presented in Volume III. This information was developed by redesigning the high sulfur coal plant for burning low sulfur sub-bituminous coal. These coal plants utilize a mechanical draft (wet) cooling tower system for condenser heat removal. Costs of alternate cooling systems are provided in Report No. 7 in this series of studies of costs of commercial electrical power plants.

  10. Capital cost: high and low sulfur coal plants-1200 MWe. [High sulfur coal

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    This Commercial Electric Power Cost Study for 1200 MWe (Nominal) high and low sulfur coal plants consists of three volumes. The high sulfur coal plant is described in Volumes I and II, while Volume III describes the low sulfur coal plant. The design basis and cost estimate for the 1232 MWe high sulfur coal plant is presented in Volume I, and the drawings, equipment list and site description are contained in Volume II. The reference design includes a lime flue gas desulfurization system. A regenerative sulfur dioxide removal system using magnesium oxide is also presented as an alternate in Section 7 Volume II. The design basis, drawings and summary cost estimate for a 1243 MWe low sulfur coal plant are presented in Volume III. This information was developed by redesigning the high sulfur coal plant for burning low sulfur sub-bituminous coal. These coal plants utilize a mechanical draft (wet) cooling tower system for condenser heat removal. Costs of alternate cooling systems are provided in Report No. 7 in this series of studies of costs of commercial electrical power plants.

  11. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Science.gov (United States)

    2010-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS § 50.4 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). Link to an... applicable to all areas notwithstanding the promulgation of SO2 national ambient air quality standards...

  12. Inverse Vulcanization of Sulfur using Natural Dienes as Sustainable Materials for Lithium-Sulfur Batteries.

    Science.gov (United States)

    Gomez, Iñaki; Leonet, Olatz; Blazquez, J Alberto; Mecerreyes, David

    2016-12-20

    Lithium-sulfur batteries are among the most promising next-generation battery systems due to the high capacity of sulfur as cathodic material. Beyond its interesting intrinsic properties, sulfur possesses a very low conductivity and complex electrochemistry, which involves the high solubility of the lithium sulfides in the electrolyte. These two characteristics are at the core of a series of limitations of its performance as active cathode material, which leads to batteries with low cyclability. Recently, inverse vulcanized sulfur was shown to retain capacity far better than elemental sulfur, leading to batteries with excellent cyclability. Nevertheless, the diene co-monomers used so far in the inverse vulcanization process are man-made molecules. Herein, a tentative work on exploring inverse vulcanization using two naturally available monomers, diallyl sulfide and myrcene, is presented. The inverse vulcanization of sulfur was successfully completed, and the resulting polymers were characterized by FTIR, NMR spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. Afterwards these polymers were tested as cathodic materials in lithium-sulfur cells. The sulfur-natural dienes materials exhibited high capacity at different C rates and high lifetime over 200 cycles with very high capacity retention at a moderate C rate of C/5. Altogether, these materials made from inexpensive and abundant chemicals are an excellent option as sustainable materials for electrochemical energy storage.

  13. Sulfur Isotope Exchange between S-35 Labeled Inorganic Sulfur-Compounds in Anoxic Marine-Sediments

    DEFF Research Database (Denmark)

    FOSSING, H.; THODEANDERSEN, S.; JØRGENSEN, BB

    1992-01-01

    Isotope exchange reactions between S-35-labeled sulfur compounds were studied in anoxic estuarine sediment slurries at 21-degrees-C and pH 7.4-7.7. Two experiments labeled with radioactive elemental sulfur (S-35-degrees) and one labeled with radioactive sulfate ((SO42-)-S-35) were performed as time...

  14. Genomic Insights into the Sulfur Metabolism of Phototrophic Green Sulfur Bacteria

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Bryant, Donald A.

    2008-01-01

    Green sulfur bacteria (GSB) utilize various combinations of sulfide, elemental sulfur, thiosulfate, ferrous iron, and hydrogen for anaerobic photoautotrophic growth. Genome sequence data is currently available for 12 strains of GSB. We present here a genome-based survey of the distribution...

  15. Direct determination of sulfur species in coals from the Argonne premium sample program by solid sampling electrothermal vaporization inductively coupled plasma optical emission spectrometry.

    Science.gov (United States)

    Bauer, Daniela; Vogt, Thomas; Klinger, Mathias; Masset, Patrick Joseph; Otto, Matthias

    2014-10-21

    A new direct solid sampling method for speciation of sulfur in coals by electrothermal vaporization inductively coupled plasma optical emission spectrometry (ETV-ICP OES) is presented. On the basis of the controlled thermal decomposition of coal in an argon atmosphere, it is possible to determine the different sulfur species in addition to elemental sulfur in coals. For the assignment of the obtained peaks from the sulfur transient emission signal, several analytical techniques (reflected light microscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy and X-ray diffraction) were used. The developed direct solid sampling method enables a good accuracy (relative standard deviation ≤ 6%), precision and was applied to determine the sulfur forms in the Argonne premium coals, varying in rank. The generated method is time- and cost-effective and well suited for the fast characterization of sulfur species in coal. It can be automated to a large extent and is applicable for process-accompanying analyses.

  16. Electrostatic self-assembly of graphene oxide wrapped sulfur particles for lithium–sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Haiwei; Huang, Ying, E-mail: yingh@nwpu.edu.cn; 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.

  17. SULFURIC ACID REMOVAL PROCESS EVALUATION: LONG-TERM RESULTS

    Energy Technology Data Exchange (ETDEWEB)

    Gary M. Blythe; Richard McMillan

    2002-07-03

    The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The project is being co-funded by the U.S. DOE National Energy Technology Laboratory, under Cooperative Agreement DE-FC26-99FT40718, along with EPRI, the American Electric Power Company (AEP), FirstEnergy Corp., the Tennessee Valley Authority, and Dravo Lime, Inc. Sulfuric acid controls are becoming of increasing interest to power generators with coal-fired units for a number of reasons. Sulfuric acid is a Toxic Release Inventory species and can cause a variety of plant operation problems such as air heater plugging and fouling, back-end corrosion, and plume opacity. These issues will likely be exacerbated with the retrofit of selective catalytic reduction (SCR) for NO{sub x} control on many coal-fired plants, as SCR catalysts are known to further oxidize a portion of the flue gas SO{sub 2} to SO{sub 3}. The project previously tested the effectiveness of furnace injection of four different calcium-and/or magnesium-based alkaline sorbents on full-scale utility boilers. These reagents were tested during four one- to two-week tests conducted on two FirstEnergy Bruce Mansfield Plant (BMP) units. One of the sorbents tested was a magnesium hydroxide byproduct slurry produced from a modified Thiosorbic{reg_sign} Lime wet flue gas desulfurization system. The other three sorbents are available commercially and include dolomite, pressure-hydrated dolomitic lime, and commercial magnesium hydroxide. The dolomite reagent was injected as a dry powder through out-of-service burners, while the other three reagents were injected as slurries through air-atomizing nozzles inserted through the front wall of the upper furnace, either across from the nose of the furnace or across from the pendant superheater tubes. After completing the four one- to two-week tests, the most promising sorbents were selected for

  18. Managing the pools of cellular redox buffers and the control of oxidative stress during the ontogeny of drought-exposed mungbean (Vigna radiata L. – role of sulfur nutrition

    Directory of Open Access Journals (Sweden)

    Naser A. Anjum

    2015-01-01

    Full Text Available Impacts of increasing environmental stresses (such as drought on crop productivity can be sustainably minimized by optimizing mineral nutrients (such as sulfur, S. This study, based on a pot-culture experiment conducted in greenhouse condition, investigates S-mediated influence of drought stress (imposed at pre-flowering, flowering and pod-filling stages on growth, photosynthesis and tolerance of mungbean (Vigna radiata L. plants. Drought stress alone hampered photosynthesis functions, enhanced oxidative stress [measured in terms of H2O2; lipid peroxidation (LPO; electrolyte leakage (EL] and decreased the pools of cellular redox buffers (namely ascorbate (AsA; glutathione (GSH], and the overall plant growth (measured as leaf area and plant dry mass, maximally at flowering stage, followed by pre-flowering and pod-filling stages. Contrarily, S-supplementation to drought-affected plants (particularly at flowering stage improved the growth- and photosynthesis-related parameters considerably. This may be ascribed to S-induced enhancements in the pools of reduced AsA and GSH, which jointly manage the balance between the production and scavenging of H2O2 and stabilize cell membrane by decreasing LPO and EL. It is inferred that alleviation of drought-caused oxidative stress depends largely on the status of AsA and GSH via S-application to drought-stressed V. radiata at an appropriate stage of plant growth, when this nutrient is maximally or efficiently utilized.

  19. Sulfur 'Concrete' for Lunar Applications - Environmental Considerations

    Science.gov (United States)

    Grugel, R. N.

    2008-01-01

    Commercial use of sulfur concrete on Earth is well established, particularly in corrosive, e.g., acid and salt, environments. Having found troilite (FeS) on the Moon raises the question of using extracted sulfur as a lunar construction material, an attractive alternative to conventional concrete as it does not require water. For the purpose of this Technical Memorandum, it is assumed that lunar ore is mined, refined, and the raw sulfur processed with appropriate lunar regolith to form, for example, bricks. With this stipulation, it is then noted that the viability of sulfur concrete in a lunar environment, which is characterized by lack of an atmosphere and extreme temperatures, is not well understood. The work presented here evaluates two sets of small sulfur concrete samples that have been prepared using JSC-1 lunar simulant as an aggregate addition. One set was subjected to extended periods in high vacuum to evaluate sublimation issues, and the other was cycled between room and liquid nitrogen temperatures to investigate their subsequent mechanical integrity. Results are presented from both investigations, discussed, and put into the context of the lunar environment.

  20. Sulfur Reduction in Acid Rock Drainage Environments.

    Science.gov (United States)

    Florentino, Anna P; Weijma, Jan; Stams, Alfons J M; Sánchez-Andrea, Irene

    2015-10-06

    Microbiological suitability of acidophilic sulfur reduction for metal recovery was explored by enriching sulfur reducers from acidic sediments at low pH (from 2 to 5) with hydrogen, glycerol, methanol and acetate as electron donors at 30 °C. The highest levels of sulfide in the enrichments were detected at pH 3 with hydrogen and pH 4 with acetate. Cloning and sequencing of the 16S rRNA gene showed dominance of the deltaproteobacterial sulfur-reducing genus Desulfurella in all the enrichments and subsequently an acidophilic strain (TR1) was isolated. Strain TR1 grew at a broad range of pH (3-7) and temperature (20-50 °C) and showed good metal tolerance (Pb(2+), Zn(2+), Cu(2+), Ni(2+)), especially for Ni(2+) and Pb(2+), with maximal tolerated concentrations of 0.09 and 0.03 mM, respectively. Different sources of sulfur were tested in the enrichments, from which biosulfur showed fastest growth (doubling time of 1.9 days), followed by colloidal, chemical and sublimated sulfur (doubling times of 2.2, 2.5, and 3.6 days, respectively). Strain TR1's physiological traits make it a good candidate to cope with low pH and high metal concentration in biotechnological processes for treatment of metal-laden acidic streams at low and moderately high temperature.

  1. Speleothem dating using Sulfur to Calcium ratio

    Science.gov (United States)

    Sabri, Raghid

    2017-04-01

    A speleothem sample from underground water tunnel in Nablus, Palestine, showed contamination from wastewater. The young sample has low concentration of Uranium and could not be dated with uranium thorium dating method. An alternative method was used to determine the age of the sample: lamina counting coupled with Sulfur to calcium ratio peaks counting. Sulfur and Calcium concentrations were measured using SEM-EDS to have a better resolution than the CNS analyzer. Assuming seasonal growth of laminations, it was possible to determine the primarily ages. The sinter was still growing during sampling in 2011. The counting reveals 271 laminae, for seasonal growth it means 135 years. In the 1959, it was observed that there is an unexpected peak of Sulfur to calcium ratio and this peak was repeated seasonally. The sulfur peak increased as a result of diesel use in the heating system during the winter season. For the youngest 117 laminae, 59 S/Ca peaks are observed. Each two lamination layers correspond to one peak. So, it was possible to determine the age of the sample using Sulfur to Calcium ratio.

  2. Mercury-Sulfur Interactions in an Experimental Peatland

    Science.gov (United States)

    Mitchell, C. P.; Coleman-Wasik, J.; Engstrom, D. R.; Swain, E.; Monson, B.; Eggert, S.; Jeremiason, J.; Balogh, S. J.; Branfireun, B. A.; Kolka, R.

    2011-12-01

    The mercury and sulfur cycles are intimately linked. For example, the production of methylmercury, the mercury species that accumulates in biota, is strongly controlled by the activity of sulfate-reducing bacteria. Of the many types of wetlands, peatlands and especially bogs are important areas of methylmercury production, partly because the hydrological and biogeochemical conditions in peatlands support anaerobes like sulfate-reducing bacteria. Given the vast coverage of peatlands in the northern U.S. and in Canada (> 1million km2), the impact of peatlands on large-scale mercury cycling could be enormous. Our current understanding of sulfur-mercury interactions in peatlands is mostly from short-duration or fine-scale experimentation, which makes extrapolation tenuous. Currently, the positive relationship between sulfate loading and methylmercury production is relatively well understood. However, the converse, how methylmercury pools are affected by reductions in sulfate loading, is entirely unknown. An important, policy-relevant question is whether reductions in sulfate deposition could lead to reductions in methylmercury loads in peatland biota, and how quickly these reductions might occur. These issues were addressed in a long-term, ecosystem-scale experiment in which sulfate loads were elevated through simulated rainfall to half of a 2-hectare peatland in northern Minnesota. Wet sulfate deposition was increased to the experimental half of a wetland from 2001 through 2006. In 2006, this increased deposition was halted in half of the experimental area (referred to as the "recovery" area thereafter), while increased deposition continued in the other half of the experimental area until the end of 2008 ("experimental"). Once increased sulfate deposition ceased, sulfate concentrations returned to background (control) levels within one year. Methylmercury concentrations in pore waters, peat, and invertebrates took three to five years to decrease to control levels once

  3. Volatile Sulfur Compounds from Livestock Production

    DEFF Research Database (Denmark)

    Kasper, Pernille

    2017-01-01

    Volatile sulfur compounds, i.e. hydrogen sulfide, methanethiol and dimethyl sulfide have been identified as key odorants in livestock production due to their high concentration levels and low odor threshold values. At the same time their removal with abatement technologies based on mass transfer...... and, thus, odor removal in these systems. In this context, two processes based on the absorptive oxidation of sulfur compounds in trickling filters containing metal catalysts were examined. One process with iron chelated by ethylenediaminetetraacetic acid (EDTA) was shown to remove hydrogen sulfide...... that the original sample composition was significantly impaired due to adsorption and diffusion at the walls of the measuring equipment. Generally, sulfur compounds were best preserved in both olfactometers and sample bags, while carboxylic acids, 4-methylphenol and trimethylamine were found to undergo substantial...

  4. Anthropogenic sulfur dioxide emissions: 1850–2005

    Directory of Open Access Journals (Sweden)

    S. J. Smith

    2011-02-01

    Full Text Available Sulfur aerosols impact human health, ecosystems, agriculture, and global and regional climate. A new annual estimate of anthropogenic global and regional sulfur dioxide emissions has been constructed spanning the period 1850–2005 using a bottom-up mass balance method, calibrated to country-level inventory data. Global emissions peaked in the early 1970s and decreased until 2000, with an increase in recent years due to increased emissions in China, international shipping, and developing countries in general. An uncertainty analysis was conducted including both random and systemic uncertainties. The overall global uncertainty in sulfur dioxide emissions is relatively small, but regional uncertainties ranged up to 30%. The largest contributors to uncertainty at present are emissions from China and international shipping. Emissions were distributed on a 0.5° grid by sector for use in coordinated climate model experiments.

  5. The Properties of Sulfur Rubber Concrete (SRC)

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The mix designs and specimen preparation for the dry process and wet process of sulfur rubber concrete (SRC) were investigated.The compressive strength, corrosion-resistance and toughness were studied and discussed.The results show that SRC is corrosion-resistanct.Although the compressive strength of SRC decreases with increasing rubber content, the toughness increases instead.Adding micro-filler will improve the compressive strength of SRC. There is a threshold value for the sulfur content, at which the compressive strength and the work ability of SRC reach an optimum balanc e.The bond between rubber particles and surrounding sulfur is strong due to the vulcanization process that generates cross-links through S-C bonds.

  6. Spatially Resolved Sulfur Speciation in Urban Soils

    Science.gov (United States)

    Brettholle, M.; Gleber, S.-C.; Mekiffer, B.; Legnini, D.; McNulty, I.; Vogt, S.; Wessolek, G.; Thieme, J.

    2011-09-01

    A combination of x-ray microscopy, elemental mapping, and XANES spectroscopy at the K-absorption edge of sulfur was used to analyze the elemental and particulate composition of an urban soil loaded with building rubble from WWII, exemplarily from Berlin, Germany. This combination of element specific high-resolution microscopy with high spectral resolution capabilities allows for the determination of elemental composition as well as chemical speciation and is therefore well suited for the analysis of highly heterogeneous environmental samples. Different soil and debris constituents could be assigned to elemental distribution patterns within collected fluorescence maps, allowing for a detailed analysis of the sulfur pool and release from war debris in subsequent studies. A detailed understanding of this sulfur lixiviation is central to preserve urban water quality.

  7. Sulfur-oxidizing bacteria in environmental technology.

    Science.gov (United States)

    Pokorna, Dana; Zabranska, Jana

    2015-11-01

    Hydrogen sulfide is widely known as the most undesirable component of biogas that caused not only serious sensoric and toxic problems, but also corrosion of concrete and steel structures. Many agricultural and industrial waste used in biogas production, may contain a large amount of substances that serve as direct precursors to the formation of sulfide sulfur-sources of hydrogen sulfide in the biogas. Biological desulfurization methods are currently promoted to abiotic methods because they are less expensive and do not produce undesirable materials which must be disposed of. The final products of oxidation of sulfides are no longer hazardous. Biological removal of sulfide from a liquid or gaseous phase is based on the activity of sulfur-oxidizing bacteria. They need an oxidizing agent such as an acceptor of electrons released during the oxidation of sulfides-atmospheric oxygen or oxidized forms of nitrogen. Different genera of sulfur-oxidizing bacteria and their technological application are discussed.

  8. Conductive framework of inverse opal structure for sulfur cathode in lithium-sulfur batteries.

    Science.gov (United States)

    Jin, Lu; Huang, Xiaopeng; Zeng, Guobo; Wu, Hua; Morbidelli, Massimo

    2016-09-07

    As a promising cathode inheritor for lithium-ion batteries, the sulfur cathode exhibits very high theoretical volumetric capacity and energy density. In its practical applications, one has to solve the insulating properties of sulfur and the shuttle effect that deteriorates cycling stability. The state-of-the-art approaches are to confine sulfur in a conductive matrix. In this work, we utilize monodisperse polystyrene nanoparticles as sacrificial templates to build polypyrrole (PPy) framework of an inverse opal structure to accommodate (encapsulate) sulfur through a combined in situ polymerization and melting infiltration approach. In the design, the interconnected conductive PPy provides open channels for sulfur infiltration, improves electrical and ionic conductivity of the embedded sulfur, and reduces polysulfide dissolution in the electrolyte through physical and chemical adsorption. The flexibility of PPy and partial filling of the inverse opal structure endure possible expansion and deformation during long-term cycling. It is found that the long cycling stability of the cells using the prepared material as the cathode can be substantially improved. The result demonstrates the possibility of constructing a pure conductive polymer framework to accommodate insulate sulfur in ion battery applications.

  9. Conductive framework of inverse opal structure for sulfur cathode in lithium-sulfur batteries

    Science.gov (United States)

    Jin, Lu; Huang, Xiaopeng; Zeng, Guobo; Wu, Hua; Morbidelli, Massimo

    2016-09-01

    As a promising cathode inheritor for lithium-ion batteries, the sulfur cathode exhibits very high theoretical volumetric capacity and energy density. In its practical applications, one has to solve the insulating properties of sulfur and the shuttle effect that deteriorates cycling stability. The state-of-the-art approaches are to confine sulfur in a conductive matrix. In this work, we utilize monodisperse polystyrene nanoparticles as sacrificial templates to build polypyrrole (PPy) framework of an inverse opal structure to accommodate (encapsulate) sulfur through a combined in situ polymerization and melting infiltration approach. In the design, the interconnected conductive PPy provides open channels for sulfur infiltration, improves electrical and ionic conductivity of the embedded sulfur, and reduces polysulfide dissolution in the electrolyte through physical and chemical adsorption. The flexibility of PPy and partial filling of the inverse opal structure endure possible expansion and deformation during long-term cycling. It is found that the long cycling stability of the cells using the prepared material as the cathode can be substantially improved. The result demonstrates the possibility of constructing a pure conductive polymer framework to accommodate insulate sulfur in ion battery applications.

  10. Sulfur turnover and emissions during storage of cattle slurry: effects of acidification and sulfur addition.

    Science.gov (United States)

    Eriksen, Jørgen; Andersen, Astrid J; Poulsen, Henrik V; Adamsen, Anders Peter S; Petersen, Søren O

    2012-01-01

    Slurry acidification using sulfuric acid reduces ammonia emissions but also affects sulfur (S) cycling. Emission of sulfur is a source of malodor and reduces the sulfur fertilizer value of the slurry. We investigated the effect of sulfate and methionine amendments, alone or in combination with acidification, on sulfur transformations in slurry and emissions of volatile sulfur compounds (VSC) during storage of fresh and aged cattle slurry. When pH was lowered to 5.5 it resulted in an almost complete inhibition of sulfate reduction. There was a huge emission of hydrogen sulfide (HS) with addition of sulfate and methionine ( slurries resulted in little accumulation of MT and dimethyl sulfide (DMS) under neutral conditions, in contrast to acidic conditions where the degradation was inhibited and both MT and DMS accumulated. Based on odor activity values, untreated slurry had little odor development from S compounds, especially the aged slurry. Acidification did not significantly increase odor contribution from any of the compounds in fresh or aged slurry. Generally, addition of a sulfate increased the contribution from HS dramatically, whereas acidification lowered the HS contribution but increased that of MT. Thus, acidification of slurry with sulfuric acid may potentially produce more odor from S compounds than untreated slurry. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  11. Sulfur contents and sulfur-isotope compositions of thiotrophic symbioses in bivalve molluscs and vestimentiferan worms

    Science.gov (United States)

    Vetter, R.D.; Fry, B.

    1998-01-01

    Total sulfur (S(TOT)), elemental sulfur (S??) and sulfur-isotope compositions (??34S) of marine animals were analyzed to determine whether these chemical characteristics could help distinguish animals with a sulfur-based, thiotrophic nutrition from animals whose nutrition is based on methanotrophy or on more normal consumption of phytoplankton-derived organic matter. The presence of S??was almost entirely confined to the symbiont-containing tissues of thiotrophs, but was sometimes undetectable in thiotrophic species where sulfide availability was probably low. When S??contents were subtracted, the remaining tissue-sulfur concentrations were similar for all nutritional groups. ??34S values were typically lower for thiotrophs than for other groups, although there was overlap in methanotroph and thiotroph values at some sites. Field evidence supported the existence of small to moderate (1 to 10???)34S fractionations in the uptake of sulfides and metabolism of thiosulfate. In general, a total sulfur content of >3% dry weight, the presence of elemental sulfur, and ??34S values less than + 5??? can be used to infer a thiotrophic mode of nutrition.

  12. Confine sulfur in mesoporous metal–organic framework @ reduced graphene oxide for lithium sulfur battery

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Weizhai [School of Metallurgy and Environment, Central South University, Changsha, Hunan 410083 (China); Zhang, Zhian, E-mail: zza75@163.com [School of Metallurgy and Environment, Central South University, Changsha, Hunan 410083 (China); Engineering Research Center of High Performance Battery Materials and Devices, Research Institute of Central South University in Shenzhen, Shenzhen 518057 (China); Qu, Yaohui; Zhou, Chengkun; Wang, Xiwen [School of Metallurgy and Environment, Central South University, Changsha, Hunan 410083 (China); Li, Jie [School of Metallurgy and Environment, Central South University, Changsha, Hunan 410083 (China); Engineering Research Center of High Performance Battery Materials and Devices, Research Institute of Central South University in Shenzhen, Shenzhen 518057 (China)

    2014-01-05

    Highlights: • Metal organic framework @ reduced graphene oxide was applied for sulfur cathode. • MIL-101(Cr)@rGO/S composites are synthesized by a facile two-step liquid method. • Cycling stability of MIL-101(Cr)@rGO/S sulfur cathode was improved. -- Abstract: Mesoporous metal organic framework @ reduced graphene oxide (MIL-101(Cr)@rGO) materials have been used as a host material to prepare the multi-composite sulfur cathode through a facile and effective two-step liquid phase method successfully, which is different from the simple MIL-101(Cr)/S mixed preparation method. The successful reduced graphene oxide coating in the MIL-101(Cr)@rGO improve the electronic conductivity of meso-MOFs effectively. The discharge capacity and capacity retention rate of MIL-101(Cr)@rGO/S composite sulfur cathode are as high as 650 mAh g{sup −1} and 66.6% at the 50th cycle at the current density of 335 mA g{sup −1}. While the discharge capacity and capacity retention rate of MIL-101(Cr)/S mixed sulfur cathode is 458 mAh g{sup −1} and 37.3%. Test results indicate that the MIL-101(Cr)@rGO is a promising host material for the sulfur cathode in the lithium–sulfur battery applications.

  13. Conductive framework of inverse opal structure for sulfur cathode in lithium-sulfur batteries

    Science.gov (United States)

    Jin, Lu; Huang, Xiaopeng; Zeng, Guobo; Wu, Hua; Morbidelli, Massimo

    2016-01-01

    As a promising cathode inheritor for lithium-ion batteries, the sulfur cathode exhibits very high theoretical volumetric capacity and energy density. In its practical applications, one has to solve the insulating properties of sulfur and the shuttle effect that deteriorates cycling stability. The state-of-the-art approaches are to confine sulfur in a conductive matrix. In this work, we utilize monodisperse polystyrene nanoparticles as sacrificial templates to build polypyrrole (PPy) framework of an inverse opal structure to accommodate (encapsulate) sulfur through a combined in situ polymerization and melting infiltration approach. In the design, the interconnected conductive PPy provides open channels for sulfur infiltration, improves electrical and ionic conductivity of the embedded sulfur, and reduces polysulfide dissolution in the electrolyte through physical and chemical adsorption. The flexibility of PPy and partial filling of the inverse opal structure endure possible expansion and deformation during long-term cycling. It is found that the long cycling stability of the cells using the prepared material as the cathode can be substantially improved. The result demonstrates the possibility of constructing a pure conductive polymer framework to accommodate insulate sulfur in ion battery applications. PMID:27600885

  14. Photochemical Formation of Sulfur-Containing Aerosols

    Science.gov (United States)

    Kroll, Jay A.; Vaida, Veronica

    2017-06-01

    In order to understand planetary climate systems, modeling the properties of atmospheric aerosols is vital. Aerosol formation plays an important role in planetary climates and is tied to feedback loops that can either warm or cool a planet. Sulfur compounds are known to play an important role in new particle aerosol formation and have been observed in a number of planetary atmospheres throughout our solar system. Our current understanding of sulfur chemistry explains much of what we observe in Earth's atmosphere; however, several discrepancies arise when comparing observations of the Venusian atmosphere with model predictions. This suggests that there are still problems in our fundamental understanding of sulfur chemistry. This is concerning given recent renewed interest in sulfate injections in the stratosphere for solar radiation management geo-engineering schemes. We investigate the role of sunlight as a potential driver of the formation of sulfur-containing aerosols. I will present recent work investigating the generation of large quantities of aerosol from the irradiation of mixtures of SO_2 with water and organic species, using a solar simulator that mimics the light that is available in the Earth's troposphere and the Venusian middle atmosphere. I will present on recent work done in our lab suggesting the formation of sulfurous acid, H_2SO_3, and describe experimental work that supports this proposed mechanism. Additionally I will present on new work showing the highly reactive nature of electronically excited SO_2 with saturated alkane species. The implications of this photochemically induced sulfur aerosol formation in the atmosphere of Earth and other planetary atmospheres will be discussed.

  15. Multiple sulfur isotope records at the end-Guadalupian (Permian) at Chaotian, China: Implications for a role of bioturbation in the Phanerozoic sulfur cycle

    Science.gov (United States)

    Saitoh, Masafumi; Ueno, Yuichiro; Matsu'ura, Fumihiro; Kawamura, Tetsuya; Isozaki, Yukio; Yao, Jianxin; Ji, Zhansheng; Yoshida, Naohiro

    2017-03-01

    A recent study on quadruple sulfur isotopes (32S, 33S, 34S, and 36S) of sedimentary pyrite suggested that the end-Guadalupian extinction was caused by shoaling of the sulfidic deep-water. This scenario is based on the assumption that sulfur isotopic compositions of pyrite from hosting sediments were controlled by benthos activities, thus by the redox conditions of the sedimentary environments. Nonetheless, the relationship between the sulfur isotope records and redox conditions, reconstructed from litho- and bio-facies, are poorly known. In order to examine the effect of bioturbation in sediments, quadruple sulfur isotopic compositions of sedimentary pyrite from the end-Guadalupian succession in Chaotian, South China, were analyzed. Black mudstones of deep-water facies immediately below the extinction horizon have consistently high Δ33S values of ca. +0.079‰, clearly suggesting a sulfate reduction in the anoxic water column. Our new data are consistent with the emergence of a sulfidic deep-water mass prior to the end-Guadalupian extinction; the upwelling of the toxic deep-water may have contributed to the extinction. In contrast, shallow-marine bioclastic limestones with burrows deposited under oxic conditions have negative Δ33S values. This anomalous isotopic signal indicates the mixing of two distinct types of pyrite; one generated during the sulfate reduction in an open system and the other in a closed system. We interpret that bioturbation supplied sulfate in the sediments and promoted sulfate reduction and in-situ sulfide precipitation within the sediments. The negative Δ33S values of oxic sediments in Chaotian are inconsistent with the previous model and demonstrate that the sedimentary sulfur cycle associated with bioturbation was more complicated than previously thought. Our study also implies that, more generally, the role of bioturbation in increasing seawater sulfate concentration in the Phanerozoic may have been overestimated in the previous

  16. Microbiological disproportionation of inorganic sulfur compounds

    DEFF Research Database (Denmark)

    Finster, Kai

    2008-01-01

    The disproportionation of inorganic sulfur intermediates at moderate temperatures (0-80 °C) is a microbiologically catalyzed chemolithotrophic process in which compounds like elemental sulfur, thiosulfate, and sulfite serve as both electron donor and acceptor, and generate hydrogen sulfide...... or phototrophic sulfide oxidizers. Investigations bridging geology and microbiology have found strong evidence for disproportionating bacteria participating in and enhancing the rate at which pyrite forms and being partly responsible for the isotopic signatures of sulfidic minerals in recent and old sediments...

  17. Sulfur reactions and cryptic cross-linkages to oxygen, iron, and carbon cyclin

    Science.gov (United States)

    Druschel, G.; Kafantaris, F. C. A.; Fike, D. A.; Schmitt-Kopplin, P.; Dvorski, S.; Oduro, H.

    2014-12-01

    Sulfur speciation in any setting is controlled by a complex series of redox reactions, polymerization, and complexation reactions that are affected by both biotic and abiotic processes. Additionally there are several crossroads of reactions with oxygen, carbon, and iron in which polysulfide molecules serve as a key reaction component that affects not only sulfur speciation, but the speciation, solubility, and bioavailability of these elements as well. Utilizing a combination of analytical approaches including electrochemistry, spectroscopy, mass spectrometry, and chromatography, we have started to unravel the interconnections between sulfur and other key elements, and how microorganisms may be either direct or indirect contributors to these chemical and mineralogical signatures. In microbial mats, we have observed microbial production of significant hydrogen peroxide under UV-stressed conditions. This peroxide interaction with hydrogen sulfide changes the kinetics and the pathways of abiotic sulfur reactions, potentially affecting the overall bioavailability and isotopic fractionations for specific reactions via a change in the linkage between oxygen and sulfur cycling. In systems containing significant iron, we have observed the production of an electroactive form of ferrous iron and sulfide (FeS(aq)) that is of a size that can be described between a dissolved molecular cluster and a small nanoparticle. This FeS(aq) can be a significant fraction of the dissolved iron or sulfide in a system, and is a key part of both the solubility of iron and sulfur and the pathways potentially important for pyritization reactions. In systems where we investigate the links between sulfur and carbon, laboratory and field experiments indicate a wide range of large and more reduced organic compounds are highly reactive towards polysulfide. Utilizing Fourier-transform ion cyclotron resonance mass spectrometry in conjunction with electrochemistry and chromatography, we are seeing a

  18. Biodesulfurization techniques: Application of selected microorganisms for organic sulfur removal from coals. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Elmore, B.B.

    1993-08-01

    As an alternative to post-combustion desulfurization of coal and pre-combustion desulfurization using physicochemical techniques, the microbial desulfurization of coal may be accomplished through the use of microbial cultures that, in an application of various microbial species, may remove both the pyritic and organic fractions of sulfur found in coal. Organisms have been isolated that readily depyritize coal but often at prohibitively low rates of desulfurization. Microbes have also been isolated that may potentially remove the organic-sulfur fraction present in coal (showing promise when acting on organic sulfur model compounds such as dibenzothiophene). The isolation and study of microorganisms demonstrating a potential for removing organic sulfur from coal has been undertaken in this project. Additionally, the organisms and mechanisms by which coal is microbially depyritized has been investigated. Three cultures were isolated that grew on dibenzothiophene (DBT), a model organic-sulfur compound, as the sole sulfur source. These cultures (UMX3, UMX9, and IGTS8) also grew on coal samples as the sole sulfur source. Numerous techniques for pretreating and ``cotreating`` coal for depyritization were also evaluated for the ability to improve the rate or extent of microbial depyritization. These include prewashing the coal with various solvents and adding surfactants to the culture broth. Using a bituminous coal containing 0.61% (w/w) pyrite washed with organic solvents at low slurry concentrations (2% w/v), the extent of depyritization was increased approximately 25% in two weeks as compared to controls. At slurry concentrations of 20% w/v, a tetrachloroethylene treatment of the coal followed by depyritization with Thiobacillus ferrooxidans increased both the rate and extent of depyritization by approximately 10%.

  19. Sulfur isotope geochemistry of ore and gangue minerals from the Silesian-Cracow Mississippi Valley-type ore district, Poland

    Science.gov (United States)

    Leach, D.L.; Vets, J.G.; Gent, C.A.

    1996-01-01

    Studies of the sulfur isotopic composition of ore and gangue minerals from the Silesian-Cracow Zn-Pb district were conducted to gain insights into processes that controlled the location and distribution of the ore deposits. Results of this study show that minerals from the Silesian-Cracow ore district have the largest range of sulfur isotope compositions in sulfides observed from any Mississippi Valley-type ore district in the world. The ??34S values for sulfide minerals range from +38 to -32 per mil for the entire paragenetic sequence but individual stages exhibit smaller ranges. There is a well developed correlation between the sulfur isotope composition and paragenetic stage of ore deposition. The first important ore stage contains mostly positive ??34S values, around 5 per mil. The second stage of ore formation are lower, with a median value of around -5 to -15 per mil, and with some values as low as -32 per mil. Late stage barite contains isotopically heavy sulfur around +32 per mil. The range in sulfur isotope compositions can be explained by contributions of sulfur from a variety of source rocks together with sulfur isotope fractionations produced by the reaction paths for sulfate reduction. Much of the variation in sulfur isotope compositions can be explained by bacterial reduction of sedimentary sulfate and disequilibrium reactions by intermediate-valency sulfur species, especially in the late-stage pyrite and sphalerite. Organic reduction of sulfate and thermal release of sulfur from coals in the Upper Silesian Coal Basin may have been important contributors to sulfur in the ore minerals. The sulfur isotopic data, ore mineral textures, and fluid inclusion data, are consistent with the hypothesis that fluid mixing was the dominant ore forming mechanism. The rather distinct lowering of ?? 34S values in sulfides from stage 2 to stage 3 is believed to reflect some fundamental change in the source of reduced sulfur and/or hydrology of the ore

  20. The influence of intramolecular sulfur-lone pair interactions on small-molecule drug design and receptor binding.

    Science.gov (United States)

    Hudson, B M; Nguyen, E; Tantillo, D J

    2016-04-28

    Sulfur-lone pair interactions are important conformational control elements in sulfur-containing heterocycles that abound in pharmaceuticals, natural products, agrochemicals, polymers and other important classes of organic molecules. Nonetheless, the role of intramolecular sulfur-lone pair interactions in the binding of small molecules to receptors is often overlooked. Here we analyze the magnitudes and origins of these interactions for a variety of biologically relevant small molecules using quantum chemical and automated docking calculations. In most cases examined in this study, the lowest energy conformation of the small molecule displays a sulfur-lone pair close contact. However, docking studies, both published and new, often predict that conformations without sulfur-lone pair contacts have the best binding affinity for their respective receptors. This is a serious problem. Since many of these predicted bound conformations are not actually energetically accessible, pursuing design (e.g., drug design) around these binding modes necessarily will lead, serendipity aside, to dead end designs. Our results constitute a caution that one best not neglect these interactions when predicting the binding affinities of potential ligands (drugs or not) for hosts (enzymes, receptors, DNA, RNA, synthetic hosts). Moreover, a better understanding and awareness of sulfur-lone pair interactions should facilitate the rational modulation of host-guest interactions involving sulfur-containing molecules.

  1. Multiple sulfur isotopes fractionations associated with abiotic sulfur transformations in Yellowstone National Park geothermal springs

    Science.gov (United States)

    2014-01-01

    Background The paper presents a quantification of main (hydrogen sulfide and sulfate), as well as of intermediate sulfur species (zero-valent sulfur (ZVS), thiosulfate, sulfite, thiocyanate) in the Yellowstone National Park (YNP) hydrothermal springs and pools. We combined these measurements with the measurements of quadruple sulfur isotope composition of sulfate, hydrogen sulfide and zero-valent sulfur. The main goal of this research is to understand multiple sulfur isotope fractionation in the system, which is dominated by complex, mostly abiotic, sulfur cycling. Results Water samples from six springs and pools in the Yellowstone National Park were characterized by pH, chloride to sulfate ratios, sulfide and intermediate sulfur species concentrations. Concentrations of sulfate in pools indicate either oxidation of sulfide by mixing of deep parent water with shallow oxic water, or surface oxidation of sulfide with atmospheric oxygen. Thiosulfate concentrations are low (<6 μmol L-1) in the pools with low pH due to fast disproportionation of thiosulfate. In the pools with higher pH, the concentration of thiosulfate varies, depending on different geochemical pathways of thiosulfate formation. The δ34S values of sulfate in four systems were close to those calculated using a mixing line of the model based on dilution and boiling of a deep hot parent water body. In two pools δ34S values of sulfate varied significantly from the values calculated from this model. Sulfur isotope fractionation between ZVS and hydrogen sulfide was close to zero at pH < 4. At higher pH zero-valent sulfur is slightly heavier than hydrogen sulfide due to equilibration in the rhombic sulfur–polysulfide – hydrogen sulfide system. Triple sulfur isotope (32S, 33S, 34S) fractionation patterns in waters of hydrothermal pools are more consistent with redox processes involving intermediate sulfur species than with bacterial sulfate reduction. Small but resolved differences in ∆33S among

  2. Enhanced cycling stability of lithium sulfur batteries using sulfur-polyaniline-graphene nanoribbon composite cathodes.

    Science.gov (United States)

    Li, Lei; Ruan, Gedeng; Peng, Zhiwei; Yang, Yang; Fei, Huilong; Raji, Abdul-Rahman O; Samuel, Errol L G; Tour, James M

    2014-09-10

    A hierarchical nanocomposite material of graphene nanoribbons combined with polyaniline and sulfur using an inexpensive, simple method has been developed. The resulting composite, characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron microscopy, and X-ray diffraction analysis, has a good rate performance and excellent cycling stability. The synergistic combination of electrically conductive graphene nanoribbons, polyaniline, and sulfur produces a composite with high performance. The method developed here is practical for the large-scale development of cathode materials for lithium sulfur batteries.

  3. Sulfur-induced structural motifs on copper and gold surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Walen, Holly [Iowa State Univ., Ames, IA (United States)

    2016-01-01

    The interaction of sulfur with copper and gold surfaces plays a fundamental role in important phenomena that include coarsening of surface nanostructures, and self-assembly of alkanethiols. Here, we identify and analyze unique sulfur-induced structural motifs observed on the low-index surfaces of these two metals. We seek out these structures in an effort to better understand the fundamental interactions between these metals and sulfur that lends to the stability and favorability of metal-sulfur complexes vs. chemisorbed atomic sulfur. The experimental observations presented here—made under identical conditions—together with extensive DFT analyses, allow comparisons and insights into factors that favor the existence of metal-sulfur complexes, vs. chemisorbed atomic sulfur, on metal terraces. We believe this data will be instrumental in better understanding the complex phenomena occurring between the surfaces of coinage metals and sulfur.

  4. Oxidation of Elemental Sulfur to Sulfite by Thiobacillus thiooxidans Cells

    OpenAIRE

    Suzuki, Isamu; Chan, C. W.; Takeuchi, T. L.

    1992-01-01

    Thiobacillus thiooxidans cells oxidized elemental sulfur to sulfite, with 1 mol of O2 consumption per mol of sulfur oxidized to sulfite, when the oxidation of sulfite was inhibited with 2-n-heptyl-4-hydroxyquinoline N-oxide.

  5. The Low-temperature Ion Sulfurizing Technology and its Applications

    Science.gov (United States)

    Ma, G. Z.; Xu, B. S.; Wang, H. D.; Li, G. L.; Zhang, S.

    A solid lubrication film mainly consists of FeS, which has excellent tribology properties, can be formed on the sulfurized iron or steel surface. The sulfurizing technology has aroused intense attention from the day it appeared. However, the widespread industrial application of sulfurizing technology was promoted by the low-temperature ion sulfurizing (LTIS) process. This paper summarized the phylogeny and sorts of sulfurizing technology firstly; then, the process flow of LTIS technology, the forming mechanism, microstructure and tribological properties of ion sulfurized layer were introduced detailedly; and then, the technological, economic and environmental merits of LTIS technology were generalized; finally, the industrial applications of LTIS technology in various typical rolling, sliding and heavy duty parts were reviewed briefly. LTIS technology, with the advantages of high sulfurizing speed, good performance of sulfurized layer and without sideeffect, has played an important role in the tribology modification of ferrous parts, and the LTIS process will become more green, simple and efficient in the future.

  6. Total Sulfur Deposition (wet+dry) from the Atmosphere

    Data.gov (United States)

    U.S. Environmental Protection Agency — 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...

  7. The Growth Mechanism of Transition Metal Dichalcogenides by using Sulfurization of Pre-deposited Transition Metals and the 2D Crystal Hetero-structure Establishment

    Science.gov (United States)

    Wu, Chong-Rong; Chang, Xiang-Rui; Wu, Chao-Hsin; Lin, Shih-Yen

    2017-01-01

    A growth model is proposed for the large-area and uniform MoS2 film grown by using sulfurization of pre-deposited Mo films on sapphire substrates. During the sulfurization procedure, the competition between the two mechanisms of the Mo oxide segregation to form small clusters and the sulfurization reaction to form planar MoS2 film is determined by the amount of background sulfur. Small Mo oxide clusters are observed under the sulfur deficient condition, while large-area and complete MoS2 films are obtained under the sulfur sufficient condition. Precise layer number controllability is also achieved by controlling the pre-deposited Mo film thicknesses. The drain currents in positive dependence on the layer numbers of the MoS2 transistors with 1-, 3- and 5- layer MoS2 have demonstrated small variation in material characteristics between each MoS2 layer prepared by using this growth technique. By sequential transition metal deposition and sulfurization procedures, a WS2/MoS2/WS2 double hetero-structure is demonstrated. Large-area growth, layer number controllability and the possibility of hetero-structure establishment by using sequential metal deposition and following sulfurization procedures have revealed the potential of this growth technique for practical applications. PMID:28176836

  8. Climate and air quality trade-offs in altering ship fuel sulfur content

    Science.gov (United States)

    Partanen, A. I.; Laakso, A.; Schmidt, A.; Kokkola, H.; Kuokkanen, T.; Pietikäinen, J.-P.; Kerminen, V.-M.; Lehtinen, K. E. J.; Laakso, L.; Korhonen, H.

    2013-12-01

    Aerosol particles from shipping emissions both cool the climate and cause adverse health effects. The cooling effect is, however, declining because of shipping emission controls aiming to improve air quality. We used an aerosol-climate model ECHAM-HAMMOZ to test whether by altering ship fuel sulfur content, the present-day aerosol-induced cooling effect from shipping could be preserved, while at the same time reducing premature mortality rates related to shipping emissions. We compared the climate and health effects of a present-day shipping emission scenario (ship fuel sulfur content of 2.7%) with (1) a simulation with strict emission controls in the coastal waters (ship fuel sulfur content of 0.1%) and twofold the present-day fuel sulfur content (i.e. 5.4%) elsewhere; and (2) a scenario with global strict shipping emission controls (ship fuel sulfur content of 0.1% in coastal waters and 0.5% elsewhere) roughly corresponding to international agreements to be enforced by the year 2020. Scenario 1 had a slightly stronger aerosol-induced effective radiative forcing (ERF) from shipping than the present-day scenario (-0.43 W m-2 vs. -0.39 W m-2) while reducing premature mortality from shipping by 69% (globally 34 900 deaths avoided per year). Scenario 2 decreased the ERF to -0.06 W m-2 and annual deaths by 96% (globally 48 200 deaths avoided per year) compared to present-day. Our results show that the cooling effect of present-day emissions could be retained with simultaneous notable improvements in air quality, even though the shipping emissions from the open ocean clearly have a significant effect on continental air quality. However, increasing ship fuel sulfur content in the open ocean would violate existing international treaties, could cause detrimental side-effects, and could be classified as geoengineering.

  9. Utilization of fumarate by sulfur-reducing bacteria Desulfuromonas sp.

    OpenAIRE

    O. Сhayka; T. Peretjatko; Gudz, S.; HALUSHKA A.

    2016-01-01

    The main goal of the work was to study the utilization of fumarate by sulfur-reducing bacteria Desulfuromonas sp. under different growth conditions and accumulation of hydrogen sulfide by bacteria in the media with sulfur and different electron donors. Sulfur-reducing bacteria Desulfuromonas sp., isolated from soil in Yazivske sulfur deposit, were used in the reasearch. Bacteria were grown in the medium Postgate C without sulfates. The content of hydrogen sulfide was determined by formation o...

  10. Field environmental evaluation plan for sulfur use in pavements

    Science.gov (United States)

    Saylak, D.; Deuel, L. E.; Izatt, J. O.; Jacobs, C.; Zahray, R.; Ham, S.

    1982-07-01

    The use of sulfur in highway paving mixtures is discussed. The evaluation procedures deal with the safety and environmental aspects of storage and handling, formulation, construction, operation and maintenance of highway pavements containing sulfur, including the possible generation of noxious and abnoxious fumes, dust and gases. Methods and equipment for monitoring potential emissions and pollutants are recommended and safety practices for the handling of sulfur and sulfur-modified asphalt mixtures and pavements are discussed.

  11. Interactions between bicarbonate, potassium, and magnesium, and sulfur-dependent induction of luminescence in Vibrio fischeri.

    Science.gov (United States)

    Tabei, Yosuke; Era, Mariko; Ogawa, Akane; Morita, Hiroshi

    2012-06-01

    In spite of its central importance in research efforts, the relationship between seawater compounds and bacterial luminescence has not previously been investigated in detail. Thus, in this study, we investigated the effect of cations (Na(+) , K(+) , NH(4) (+) , Mg(2+) , and Ca(2+) ) and anions (Cl(-) , HCO(3) (-) , CO(3) (2-) , and NO(3) (-) ) on the induction of both inorganic (sulfate, sulfite, and thiosulfate) and organic (L-cysteine and L-cystine) sulfur-dependent luminescence in Vibrio fischeri. We found that HCO(3) (-) (bicarbonate) and CO(3) (2-) (carbonate), in the form of various compounds, had a stimulatory effect on sulfur-dependent luminescence. The luminescence induced by bicarbonate was further promoted by the addition of magnesium. Potassium also increased sulfur-dependent luminescence when sulfate or thiosulfate was supplied as the sole sulfur source, but not when sulfite, L-cysteine, or L-cystine was supplied. The positive effect of potassium was accelerated by the addition of magnesium and/or calcium. Furthermore, the additional supply of magnesium improved the induction of sulfite- or L-cysteine-dependent luminescence, but not the l-cystine-dependent type. These results suggest that sulfur-dependent luminescence of V. fischeri under nutrient-starved conditions is mainly controlled by bicarbonate, carbonate, and potassium. In addition, our results indicate that an additional supply of magnesium is effective for increasing V. fischeri luminescence.

  12. New insights into sulfur metabolism in yeasts as revealed by studies of Yarrowia lipolytica.

    Science.gov (United States)

    Hébert, Agnès; Forquin-Gomez, Marie-Pierre; Roux, Aurélie; Aubert, Julie; Junot, Christophe; Heilier, Jean-François; Landaud, Sophie; Bonnarme, Pascal; Beckerich, Jean-Marie

    2013-02-01

    Yarrowia lipolytica, located at the frontier of hemiascomycetous yeasts and fungi, is an excellent candidate for studies of metabolism evolution. This yeast, widely recognized for its technological applications, in particular produces volatile sulfur compounds (VSCs) that fully contribute to the flavor of smear cheese. We report here a relevant global vision of sulfur metabolism in Y. lipolytica based on a comparison between high- and low-sulfur source supplies (sulfate, methionine, or cystine) by combined approaches (transcriptomics, metabolite profiling, and VSC analysis). The strongest repression of the sulfate assimilation pathway was observed in the case of high methionine supply, together with a large accumulation of sulfur intermediates. A high sulfate supply seems to provoke considerable cellular stress via sulfite production, resulting in a decrease of the availability of the glutathione pathway's sulfur intermediates. The most limited effect was observed for the cystine supply, suggesting that the intracellular cysteine level is more controlled than that of methionine and sulfate. Using a combination of metabolomic profiling and genetic experiments, we revealed taurine and hypotaurine metabolism in yeast for the first time. On the basis of a phylogenetic study, we then demonstrated that this pathway was lost by some of the hemiascomycetous yeasts during evolution.

  13. Quantitative transcriptome, proteome, and sulfur metabolite profiling of the Saccharomyces cerevisiae response to arsenite.

    Science.gov (United States)

    Thorsen, Michael; Lagniel, Gilles; Kristiansson, Erik; Junot, Christophe; Nerman, Olle; Labarre, Jean; Tamás, Markus J

    2007-06-19

    Arsenic is ubiquitously present in nature, and various mechanisms have evolved enabling cells to evade toxicity and acquire tolerance. Herein, we explored how Saccharomyces cerevisiae (budding yeast) respond to trivalent arsenic (arsenite) by quantitative transcriptome, proteome, and sulfur metabolite profiling. Arsenite exposure affected transcription of genes encoding functions related to protein biosynthesis, arsenic detoxification, oxidative stress defense, redox maintenance, and proteolytic activity. Importantly, we observed that nearly all components of the sulfate assimilation and glutathione biosynthesis pathways were induced at both gene and protein levels. Kinetic metabolic profiling evidenced a significant increase in the pools of sulfur metabolites as well as elevated cellular glutathione levels. Moreover, the flux in the sulfur assimilation pathway as well as the glutathione synthesis rate strongly increased with a concomitant reduction of sulfur incorporation into proteins. By combining comparative genomics and molecular analyses, we pinpointed transcription factors that mediate the core of the transcriptional response to arsenite. Taken together, our data reveal that arsenite-exposed cells channel a large part of assimilated sulfur into glutathione biosynthesis, and we provide evidence that the transcriptional regulators Yap1p and Met4p control this response in concert.

  14. Photocatalytic Oxidation of Sulfurous Acid in an Aqueous Medium

    Science.gov (United States)

    Romero, Alicia; Hernandez, Willie; Suarez, Marco F.

    2005-01-01

    The effect of some parameters on sulfurous acid and sulfur oxidation kinetics such as initial concentration of sulfurous acid, oxygen, TiO[2] crystalline concentration, the power of black light, and quantity of TiO[2] is investigated. The experiments can be performed in an undergraduate physical chemistry laboratory with an inexpensive…

  15. Mercury chemisorption by sulfur adsorbed in porous materials

    NARCIS (Netherlands)

    Steijns, M.; Peppelenbos, A.; Mars, P.

    1976-01-01

    The sorption of mercury vapor by adsorbed sulfur in the zeolites CaA (= 5A) and NaX (=13X) and two types of active carbon has been measured at a temperature of 50°C. With increasing degree of micropore filling by sulfur the fraction of sulfur accessible to mercury atoms decreased for CaA and NaX.

  16. Photocatalytic Oxidation of Sulfurous Acid in an Aqueous Medium

    Science.gov (United States)

    Romero, Alicia; Hernandez, Willie; Suarez, Marco F.

    2005-01-01

    The effect of some parameters on sulfurous acid and sulfur oxidation kinetics such as initial concentration of sulfurous acid, oxygen, TiO[2] crystalline concentration, the power of black light, and quantity of TiO[2] is investigated. The experiments can be performed in an undergraduate physical chemistry laboratory with an inexpensive…

  17. Annotated bibliography of methods for determining sulfur and forms of sulfur in coal and coal-related materials

    Energy Technology Data Exchange (ETDEWEB)

    Chriswell, C.D.; Norton, G.A.; Akhtar, S.S.; Straszheim, W.E.; Markuszewski, R.

    1993-01-01

    Over 400 published papers, presentations at scientific meetings, and reports relating to the determination of sulfur and sulfur forms in coal-related materials have been accumulated, classified, and an evaluation made of their content.

  18. Process for removing sulfur from sulfur-containing gases: high calcium fly-ash

    Science.gov (United States)

    Rochelle, Gary T.; Chang, John C. S.

    1991-01-01

    The present disclosure relates to improved processes for treating hot sulfur-containing flue gas to remove sulfur therefrom. Processes in accordance with the present invention include preparing an aqueous slurry composed of a calcium alkali source and a source of reactive silica and/or alumina, heating the slurry to above-ambient temperatures for a period of time in order to facilitate the formation of sulfur-absorbing calcium silicates or aluminates, and treating the gas with the heat-treated slurry components. Examples disclosed herein demonstrate the utility of these processes in achieving improved sulfur-absorbing capabilities. Additionally, disclosure is provided which illustrates preferred configurations for employing the present processes both as a dry sorbent injection and for use in conjunction with a spray dryer and/or bagfilter. Retrofit application to existing systems is also addressed.

  19. Phase transformations and the spectral reflectance of solid sulfur - Can metastable sulfur allotropes exist on Io?

    Science.gov (United States)

    Moses, Julianne I.; Nash, Douglas B.

    1991-01-01

    Laboratory investigations have been conducted on the effects of variations in sulfur sample histories on their solid-state transformation rate and the corresponding spectral variation of freshly frozen sulfur. The temporal variations in question may be due to differences in the amount and type of metastable allotropes present in the sulfur after solidification, as well as to the physics of the phase-transformation process itself. The results obtained are pertinent to the physical behavior and spectral variation of such freshly solidified sulfur as may exist on the Jupiter moon Io; this would initially solidify into a glassy solid or monoclinic crystalline lattice, then approach ambient dayside temperatures. Laboratory results imply that the monoclinic or polymeric allotropes can in these circumstances be maintained, and will take years to convert to the stable orthorhombic crystalline form.

  20. Microwave Characterization of Propiolic Sulfuric Anhydride and Two Conformers of Acrylic Sulfuric Anhydride

    Science.gov (United States)

    Smith, CJ; Huff, Anna; Mackenzie, Becca; Leopold, Ken

    2017-06-01

    Sulfur trioxide reacts with propiolic acid and acrylic acid to form propiolic sulfuric anhydride (HC\\equivC-COOSO_{2}OH) and acrylic sulfuric anhydride (H_{2}C=CH-COOSO_{2}OH), respectively. Both species have been observed by chirped-pulse and conventional cavity microwave spectroscopy. In the case of acrylic acid, two conformers derived from the cis and trans form of the acid have been observed. The reaction mechanism and energetics are investigated by density functional theory and CCSD calculations. These results add to a growing body of evidence that establishes carboxylic sulfuric anhydrides, RCOOSO_{2}OH, as a class of molecules formed readily from SO_{3} + RCOOH in the gas phase and which, therefore, may be of significance in the nucleation and growth of atmospheric aerosol particles.

  1. RETENTION OF SULFUR DIOXIDE BY NYLON FILTERS

    Science.gov (United States)

    Based on laboratory studies, recovery efficiencies of sulfur dioxide (SO2) were determined for nylon filters. The nylon filters used in these experiments were found to retain SO2. A relatively uniform amount (1.7%) was recoverable from each nylon filter, independent of relative...

  2. REGIONAL TRENDS IN RURAL SULFUR CONCENTRATIONS

    Science.gov (United States)

    This paper presents an analysis of trends in atmospheric concentrations of sulfur dioxide (SO,) and particulate sulfate (SO42-) 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 to estimat...

  3. Helium and Sulfur Hexafluoride in Musical Instruments

    Science.gov (United States)

    Forinash, Kyle; Dixon, Cory L.

    2014-01-01

    The effects of inhaled helium on the human voice were investigated in a recent article in "The Physics Teacher." As mentioned in that article, demonstrations of the effect are a popular classroom activity. If the number of YouTube videos is any indication, the effects of sulfur hexafluoride on the human voice are equally popular.…

  4. Biologically produced sulfur particles and polysulfide ions

    NARCIS (Netherlands)

    Kleinjan, W.E.

    2005-01-01

    This thesis deals with the effects of particles of biologically produced sulfur (or 'biosulfur') on a biotechnological process for the removal of hydrogen sulfide from gas streams. Particular emphasis is given to the role of polysulfide ions in such a process. These polysul

  5. 21 CFR 582.3862 - Sulfur dioxide.

    Science.gov (United States)

    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, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives §...

  6. 21 CFR 182.3862 - Sulfur dioxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sulfur dioxide. 182.3862 Section 182.3862 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 182.3862...

  7. Biologically produced sulfur particles and polysulfide ions

    NARCIS (Netherlands)

    Kleinjan, W.E.

    2005-01-01

    This thesis deals with the effects of particles of biologically produced sulfur (or 'biosulfur') on a biotechnological process for the removal of hydrogen sulfide from gas streams. Particular emphasis is given to the role of polysulfide ions in such a process. These

  8. Development of enhanced sulfur rejection processes

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, R.H.; Luttrell, G.H.; Adel, G.T.; Richardson, P.E.

    1996-03-01

    Research at Virginia Tech led to the development of two complementary concepts for improving the removal of inorganic sulfur from many eastern U.S. coals. These concepts are referred to as Electrochemically Enhanced Sulfur Rejection (EESR) and Polymer Enhanced Sulfur Rejection (PESR) processes. The EESR process uses electrochemical techniques to suppress the formation of hydrophobic oxidation products believed to be responsible for the floatability of coal pyrite. The PESR process uses polymeric reagents that react with pyrite and convert floatable middlings, i.e., composite particles composed of pyrite with coal inclusions, into hydrophilic particles. These new pyritic-sulfur rejection processes do not require significant modifications to existing coal preparation facilities, thereby enhancing their adoptability by the coal industry. It is believed that these processes can be used simultaneously to maximize the rejection of both well-liberated pyrite and composite coal-pyrite particles. The project was initiated on October 1, 1992 and all technical work has been completed. This report is based on the research carried out under Tasks 2-7 described in the project proposal. These tasks include Characterization, Electrochemical Studies, In Situ Monitoring of Reagent Adsorption on Pyrite, Bench Scale Testing of the EESR Process, Bench Scale Testing of the PESR Process, and Modeling and Simulation.

  9. Origin of electrolyte-dopant dependent sulfur poisoning of SOFC anodes

    DEFF Research Database (Denmark)

    Zeng, Zhenhua; Björketun, Mårten E; Ebbesen, Sune;

    2013-01-01

    -S interaction and on the relative stability of reconstructed and pristine Ni(100) facets at the TPB. Together, these two effects control the sulfur adsorption on the Ni atoms at the TPB. The established relationships explain experimentally observed dopant-dependent anode performances and provide a blueprint...

  10. Analysis of emission charges as a method of reducing sulfur pollution

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, D.G.; Chen, P.W.

    1976-06-01

    Requiring sulfur polluters to make payments which are functions of the emissions discharged (the ''polluter-pay-principle'') is a method of regulation which is an alternative but not an equivalent to the setting of sulfur-emission standards and the punishing of those who permit the emission of the facilities under their control to exceed these standards. It is shown that this approach gives greater incentives toward the rapid reduction of sulfur emissions than does the setting of standards, particularly when the charges are adjusted to represent estimates of the health and property damage resulting from the emissions. Some variations of an extension of the polluter-pay-principle are also examined.

  11. Advances in lithium-sulfur batteries based on multifunctional cathodes and electrolytes

    Science.gov (United States)

    Pang, Quan; Liang, Xiao; Kwok, Chun Yuen; Nazar, Linda F.

    2016-09-01

    Amid burgeoning environmental concerns, electrochemical energy storage has rapidly gained momentum. Among the contenders in the ‘beyond lithium’ energy storage arena, the lithium-sulfur (Li-S) battery has emerged as particularly promising, owing to its potential to reversibly store considerable electrical energy at low cost. Whether or not Li-S energy storage will be able to fulfil this potential depends on simultaneously solving many aspects of its underlying conversion chemistry. Here, we review recent developments in tackling the dissolution of polysulfides — a fundamental problem in Li-S batteries — focusing on both experimental and computational approaches to tailor the chemical interactions between the sulfur host materials and polysulfides. We also discuss smart cathode architectures enabled by recent materials engineering, especially for high areal sulfur loading, as well as innovative electrolyte design to control the solubility of polysulfides. Key factors that allow long-life and high-loading Li-S batteries are summarized.

  12. Maps of critical loads and exceedance for sulfur and nitrogen to forest soils in Norway

    Energy Technology Data Exchange (ETDEWEB)

    Frogner, T.; Wright, R.F.; Cosby, B.J.; Esser, J.M.

    1994-12-31

    This report uses the dynamic MAGIC (Model of Acidification of Groundwater in Catchments) model to calculate critical loads of sulfur and nitrogen for forest soils in Norway. Inputs include soil survey data, atmospheric deposition data, forest productivity data, and surface water chemistry. Two scenarios for future sulfur deposition are used with two scenarios of nitrogen retention in catchments. The magnitude and patterns of calculated nitrogen critical loads and exceedance differ substantially depending on the scenario chosen for sulfur deposition and nitrogen retention. In the worst case, critical loads for N are low and exceeded in southernmost Norway. In the best case, critical loads for N are high and not exceeded. More information on the processes controlling N retention in forested ecosystems is of utmost importance for the specification of nitrogen critical loads. 25 refs., 14 figs., 1 table

  13. Effects of sulfur-and polymer-coated controlled release urea on yield,photosynthetic characteristics and nitrogen fertilizer efficiency of rice%硫膜和树脂膜控释尿素对水稻产量、光合特性及氮肥利用率的影响

    Institute of Scientific and Technical Information of China (English)

    李敏; 郭熙盛; 叶舒娅; 刘枫; 袁嫚嫚; 黄义德

    2013-01-01

    Using sulfur-and polymer-coated controlled release urea (SPCU,PCU) with a releasing period of 90 days as experimental materials,a pot experiment was conducted to study the effects of sulfur-and polymer-coated controlled release urea on yield and photosynthetic characteristics and nitrogen fertilizer efficiency of rice.Compared with the conventional urea (U),the controlled release urea significantly increases the grain yields by 15.1%-51.4%,and increases the nitrogen apparent efficiencies and nitrogen agronomic efficiencies by 64.5%-141.1% and 5.4-18.2 kg/kg,respectively.The controlled release urea could greatly improve the net photosynthetic rate in flat leaves of rice and enhance SPAD during the middle-late growth stages.Compared with the conventional urea split,the polymer-coated controlled release urea and the 70% sulfur-coated controlled release urea combined with 30% conventional urea markedly increase the grain yields by 7.9%-31.7%,and the nitrogen agronomic efficiencies and soil total N and available N are increased by 3.3-13.0 kg/kg and 2.2%-17.6% and 13.2%-22.0%,respectively,and the net photosynthetic rate in flat leaves at the middle-late growth stages are also significantly increased.The effect of the 100% polymer-coated controlled release urea is most important.Compared with the conventional urea and the conventional urea split,the polymer-coated controlled release urea could significantly increase nitrogen fertilizer physiological efficiency of rice.The polymer-coated controlled release urea produces better rice yield and has higher nitrogen fertilizer efficiency and effective photosynthetic characteristics,compared with the sulfur-coated controlled release urea.%本试验以控释期为90d的硫膜(SPCU)和树脂膜(PCU)控释尿素为材料,通过盆栽试验,研究了硫膜和树脂膜控释尿素对水稻产量、光合特性及氮肥利用效率的影响.结果表明,与普通尿素(U)一次基施相比,控释尿素各

  14. Characterization of sulfur oxidizing bacteria related to biogenic sulfuric acid corrosion in sludge digesters.

    Science.gov (United States)

    Huber, Bettina; Herzog, Bastian; Drewes, Jörg E; Koch, Konrad; Müller, Elisabeth

    2016-07-18

    Biogenic sulfuric acid (BSA) corrosion damages sewerage and wastewater treatment facilities but is not well investigated in sludge digesters. Sulfur/sulfide oxidizing bacteria (SOB) oxidize sulfur compounds to sulfuric acid, inducing BSA corrosion. To obtain more information on BSA corrosion in sludge digesters, microbial communities from six different, BSA-damaged, digesters were analyzed using culture dependent methods and subsequent polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE). BSA production was determined in laboratory scale systems with mixed and pure cultures, and in-situ with concrete specimens from the digester headspace and sludge zones. The SOB Acidithiobacillus thiooxidans, Thiomonas intermedia, and Thiomonas perometabolis were cultivated and compared to PCR-DGGE results, revealing the presence of additional acidophilic and neutrophilic SOB. Sulfate concentrations of 10-87 mmol/L after 6-21 days of incubation (final pH 1.0-2.0) in mixed cultures, and up to 433 mmol/L after 42 days (final pH sulfuric acid production potentials. Additionally, elevated sulfate concentrations in the corroded concrete of the digester headspace in contrast to the concrete of the sludge zone indicated biological sulfur/sulfide oxidation. The presence of SOB and confirmation of their sulfuric acid production under laboratory conditions reveal that these organisms might contribute to BSA corrosion within sludge digesters. Elevated sulfate concentrations on the corroded concrete wall in the digester headspace (compared to the sludge zone) further indicate biological sulfur/sulfide oxidation in-situ. For the first time, SOB presence and activity is directly relatable to BSA corrosion in sludge digesters.

  15. Capsaicinoids, chloropicrin and sulfur mustard: Possibilities for exposure biomarkers

    Directory of Open Access Journals (Sweden)

    Maija Pesonen

    2010-12-01

    Full Text Available Incapacitating and irritating agents produce temporary disability persisting for hours to days after the exposure. One can be exposed to these agents occupationally in industrial or other working environments. Also general public can be exposed in special circumstances, like industrial accidents or riots. Incapacitating and irritating agents discussed in this review are chloropicrin and capsaicinoids. In addition, we include sulfur mustard, which is an old chemical warfare agent and known to cause severe long-lasting injuries or even death. Chloropicrin that was used as a warfare agent in the World War I is currently used mainly as a pesticide. Capsaicinoids, components of hot pepper plants, are used by police and other law enforcement personnel as riot control agents. Toxicity of these chemicals is associated particularly with the respiratory tract, eyes and skin. Their acute effects are relatively well known but the knowledge of putative long-term effects is almost non-existent. Also, mechanisms of effects at cellular level are not fully understood. There is a need for further research to get better idea of health risks, particularly of long-term and low-level exposures to these chemicals. For this, exposure biomarkers are essential. Validated exposure biomarkers for capsaicinoids, chloropicrin and sulfur mustard do not exist so far. Metabolites and macromolecular adducts have been suggested biomarkers for sulfur mustard and these can already be measured qualitatively, but quantitative biomarkers await further development and validation. The purpose of this review is, based on the existing mechanistic and toxicokinetic information, to shed light on the possibilities for developing biomarkers for exposure biomonitoring of these compounds. It is also of interest to find ideas for early effect biomarkers considering the need for studies on subchronic and chronic toxicity.

  16. FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID REMOVAL

    Energy Technology Data Exchange (ETDEWEB)

    Gary M. Blythe

    2004-01-01

    The objective of this project has been to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The project was co-funded by the U.S. DOE National Energy Technology Laboratory under Cooperative Agreement DE-FC26-99FT40718, along with EPRI, the American Electric Power Company (AEP), FirstEnergy Corporation, the Tennessee Valley Authority, and Carmeuse North America. Sulfuric acid controls are becoming of increased interest for coal-fired power generating units for a number of reasons. In particular, sulfuric acid can cause plant operation problems such as air heater plugging and fouling, back-end corrosion, and plume opacity. These issues will likely be exacerbated with the retrofit of selective catalytic reduction (SCR) for NOX control, as SCR catalysts are known to further oxidize a portion of the flue gas SO{sub 2} to SO{sub 3}. The project tested the effectiveness of furnace injection of four different magnesium-based or dolomitic alkaline sorbents on full-scale utility boilers. These reagents were tested during one- to two-week tests conducted on two FirstEnergy Bruce Mansfield Plant (BMP) units. One of the sorbents tested was a magnesium hydroxide slurry byproduct from a modified Thiosorbic{reg_sign} Lime wet flue gas desulfurization process. The other three sorbents are available commercially and include dolomite, pressure-hydrated dolomitic lime, and commercially available magnesium hydroxide. The dolomite reagent was injected as a dry powder through out-of-service burners. The other three reagents were injected as slurries through air-atomizing nozzles inserted through the front wall of the upper furnace. After completing the four one- to two-week tests, the most promising sorbents were selected for longer-term (approximately 25-day) full-scale tests on two different units. The longer-term tests were conducted to confirm sorbent effectiveness over extended operation on two

  17. Effects of sulfur oxides on eicosanoids

    Energy Technology Data Exchange (ETDEWEB)

    Chen, L.C.; Miller, P.D.; Amdur, M.O. (New York Univ. Medical Center, Tuxedo (USA))

    1989-01-01

    Ultrafine metal oxides and SO2 react during coal combustion or smelting operations to form primary emissions coated with an acidic SOx layer. Ongoing work in this laboratory has examined the effects of sulfur oxides on pulmonary functions of guinea pigs. We have previously reported that 20 micrograms/m3 acidic sulfur oxide as a surface layer on ultrafine ZnO particles decreases lung volumes, decreases carbon monoxide diffusing capacity, and causes lung inflammation in guinea pigs after 4 daily 3-h exposures. It also produces bronchial hypersensitivity following a single 1-h exposure. The importance of this surface layer is demonstrated by our observation that 200 micrograms/m3 of sulfuric acid droplets of equivalent size are needed to produce the same degree of hypersensitivity. This study characterized the concentration-dependent effects of in vivo exposures to sulfur oxides on arachidonic acid metabolism in the guinea pig lung, and investigated the time course and the relation between eicosanoid composition and pulmonary functions. We focused specifically on four cyclooxygenase metabolites of arachidonic acid, that is, prostaglandins (PG) E1, F2 alpha, 6-keto prostaglandin F1 alpha, and thromboxane (Tx) B2, and two groups of sulfidopeptide leukotrienes (C4, D4, E4, and F4). Guinea pigs were exposed to ultrafine ZnO aerosol (count median diameter = 0.05 microns, sigma g = 1.80) with a layer of acidic sulfur oxide on the surface of the particles. Lung lavage was collected after exposures, and the levels of arachidonic acid metabolites were determined using radioimmunoassay (RIA). Concentration-dependent promotion of PGF2 alpha and concentration-dependent suppression of LtB4 were observed. The increased PGF2 alpha was associated with depressed vital capacity and diffusing capacity of the lungs measured in guinea pigs exposed to the same atmosphere described in a previous study.

  18. Application of gelatin as a binder for the sulfur cathode in lithium-sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Sun Jing [Department of Material Science and Engineering, Beijing University of Chemical Technology, 15 BeiSanhuan East Road, Beijing 100029 (China); Huang Yaqin [Department of Material Science and Engineering, Beijing University of Chemical Technology, 15 BeiSanhuan East Road, Beijing 100029 (China)], E-mail: huangyaqin9@sina.com; Wang Weikun; Yu Zhongbao; Wang Anbang; Yuan Keguo [Military Power Sources Research and Development Center, Chemical Defense Institute, 35 Huayuan North Road, Beijing 100083 (China)

    2008-10-15

    Gelatin, a natural biological macromolecule, was successfully used as a new binder in place of poly(ethylene oxide) (PEO) in the fabrication of the sulfur cathode in lithium-sulfur batteries. The structure and electrochemical performance of the two types of sulfur cathodes, with gelatin and PEO as binders, respectively, were compared in 1 M LiClO{sub 4} DME/DOL (V/V = 1/1) electrolyte. The results showed that the gelatin binder had multifunctional effects on the sulfur cathode: it not only functioned as a highly adhesive agent and an effective dispersion agent for the cathode materials, but also an electrochemically stable binder. The gelatin binder-sulfur cathode achieved a high initial capacity of 1132 mAh g{sup -1}, and remained at a reversible capacity of 408 mAh g{sup -1} after 50 cycles, all of which were better than with the PEO binder-sulfur cathode under the same conditions.

  19. Application of gelatin as a binder for the sulfur cathode in lithium-sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Jing; Huang, Yaqin [Department of Material Science and Engineering, Beijing University of Chemical Technology, 15 BeiSanhuan East Road, Beijing 100029 (China); Wang, Weikun; Yu, Zhongbao; Wang, Anbang; Yuan, Keguo [Military Power Sources Research and Development Center, Chemical Defense Institute, 35 Huayuan North Road, Beijing 100083 (China)

    2008-10-15

    Gelatin, a natural biological macromolecule, was successfully used as a new binder in place of poly(ethylene oxide) (PEO) in the fabrication of the sulfur cathode in lithium-sulfur batteries. The structure and electrochemical performance of the two types of sulfur cathodes, with gelatin and PEO as binders, respectively, were compared in 1 M LiClO{sub 4} DME/DOL (V/V = 1/1) electrolyte. The results showed that the gelatin binder had multifunctional effects on the sulfur cathode: it not only functioned as a highly adhesive agent and an effective dispersion agent for the cathode materials, but also an electrochemically stable binder. The gelatin binder-sulfur cathode achieved a high initial capacity of 1132 mAh g{sup -1}, and remained at a reversible capacity of 408 mAh g{sup -1} after 50 cycles, all of which were better than with the PEO binder-sulfur cathode under the same conditions. (author)

  20. Preparation and electrochemical performance of sulfur-alumina cathode material for lithium-sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Kang [Faculty of Material Science and Chemistry, China University of Geosciences, 388 Lumo Road, 430074 Wuhan (China); Wang, Shengping, E-mail: spwang@cug.edu.cn [Faculty of Material Science and Chemistry, China University of Geosciences, 388 Lumo Road, 430074 Wuhan (China); Zhang, Hanyu; Wu, Jinping [Faculty of Material Science and Chemistry, China University of Geosciences, 388 Lumo Road, 430074 Wuhan (China)

    2013-06-01

    Highlights: ► Micron-sized alumina was synthesized as adsorbent for lithium-sulfur batteries. ► Sulfur-alumina material was synthesized via crystallizing nucleation. ► The Al{sub 2}O{sub 3} can provide surface area for the deposition of Li{sub 2}S and Li{sub 2}S{sub 2}. ► The discharge capacity of the battery is improved during the first several cycles. - Abstract: Nano-sized sulfur particles exhibiting good adhesion with conducting acetylene black and alumina composite materials were synthesized by means of an evaporated solvent and a concentrated crystallization method for use as the cathodes of lithium-sulfur batteries. The composites were characterized and examined by X-ray diffraction, environmental scanning electron microscopy and electrochemical methods, such as cyclic voltammetry, electrical impedance spectroscopy and charge–discharge tests. Micron-sized flaky alumina was employed as an adsorbent for the cathode material. The initial discharge capacity of the cathode with the added alumina was 1171 mAh g{sup −1}, and the remaining capacity was 585 mAh g{sup −1} after 50 cycles at 0.25 mA cm{sup −2}. Compared with bare sulfur electrodes, the electrodes containing alumina showed an obviously superior cycle performance, confirming that alumina can contribute to reducing the dissolution of polysulfides into electrolytes during the sulfur charge–discharge process.

  1. Effects of Sulfurization Temperature on Properties of CZTS Films by Vacuum Evaporation and Sulfurization Method

    Directory of Open Access Journals (Sweden)

    Jie Zhang

    2013-01-01

    Full Text Available Copper zinc tin sulfur (CZTS thin films have been extensively studied in recent years for their advantages of low cost, high absorption coefficient (≥104 cm−1, appropriate band gap (~1.5 eV, and nontoxicity. CZTS thin films are promising materials of solar cells like copper indium gallium selenide (CIGS. In this work, CZTS thin films were prepared on glass substrates by vacuum evaporation and sulfurization method. Sn/Cu/ZnS (CZT precursors were deposited by thermal evaporation and then sulfurized in N2 + H2S atmosphere at temperatures of 360–560°C to produce polycrystalline CZTS thin films. It is found that there are some impurity phases in the thin films with the sulfurization temperature less than 500°C, and the crystallite size of CZTS is quite small. With the further increase of the sulfurization temperature, the obtained thin films exhibit preferred (112 orientation with larger crystallite size and higher density. When the sulfurization temperature is 500°C, the band gap energy, resistivity, carrier concentration, and mobility of the CZTS thin films are 1.49 eV, 9.37 Ω · cm, 1.714×1017 cm−3, and 3.89 cm2/(V · s, respectively. Therefore, the prepared CZTS thin films are suitable for absorbers of solar cells.

  2. A new study of an old sink of sulfur in hot molecular cores: the sulfur residue

    CERN Document Server

    Woods, Paul M; Viti, Serena; Kanuchova, Z; Palumbo, Maria Elisabetta; Price, Stephen D

    2015-01-01

    Sulfur appears to be depleted by an order of magnitude or more from its elemental abundance in star-forming regions. In the last few years, numerous observations and experiments have been performed in order to to understand the reasons behind this depletion without providing a satisfactory explanation of the sulfur chemistry towards high-mass star-forming cores. Several sulfur-bearing molecules have been observed in these regions, and yet none are abundant enough to make up the gas-phase deficit. Where, then, does this hidden sulfur reside? This paper represents a step forward in our understanding of the interactions among the various S-bearing species. We have incorporated recent experimental and theoretical data into a chemical model of a hot molecular core in order to see whether they give any indication of the identity of the sulfur sink in these dense regions. Despite our model producing reasonable agreement with both solid-phase and gas-phase abundances of many sulfur-bearing species, we find that the s...

  3. SYNTHESIS OF SULFUR-BASED WATER TREATMENT AGENT FROM SULFUR DIOXIDE WASTE STREAMS

    Energy Technology Data Exchange (ETDEWEB)

    Robert C. Brown; Maohong Fan; Adrienne Cooper

    2004-11-01

    showed that both temperature and concentration of the coagulants substantially impact corrosion rates. The corrosion rates increased with the increase of temperature and concentration. The results from a scanning electron microscope (SEM) showed that chloride caused more serious pitting than sulfate anion on both aluminum and steel specimens. Although SEM confirmed the existence of pitting corrosion, the results of weight loss indicated that the uniform corrosion predominate the corrosion mechanism, and pitting corrosion played a less important role. The test proved that PFS was less corrosive than FC, which may lead to the large-scale application of PFS in waste treatment. The kinetics of the new desulfurization process has been studied. The study results provide the theoretical guidance for improving sulfur removal efficiency and controlling the quality of PFS.

  4. 微波辐射下耐硫型Pd催化剂的可控制备及在一步法合成二甲醚中的应用%Controllable preparation of sulfur-tolerant Pd catalysts under microwave irradiation and application of these catalystsin one-step synthesis of dimethyl ether

    Institute of Scientific and Technical Information of China (English)

    褚睿智

    2012-01-01

    According to the development of the direct syngas to DME(STD)technology,in this work,the hybrid catalyst preparation of Palladiuman(Pd) metal-supportfor DME synthesis by microwave technology was studied and developed,which has a good effect of sulfur tolerance.All research was divided into following three sections. Firstly,Pd metal-support catalystfor STD reaction was researched.Three series of Palladiuman catalysts supported on different carriers,γ-Al2O3,HZSM-5 and Al-MCM-41respectively,were prepared by impregnation.The properties of catalysts,such as surface phase structure and adsorption,reduction properties,surface acidity were controlled by changing calcination condition,Pd loading,or single and binary promoters and its added amount.The relationship between STD reactivity and the intrinsic characteristics of the catalyst were investigated. Secondly,the sulfur-tolerant mechanism of Pd catalysts was researched.The STD activity of catalysts after the process ofsulfur poisoning with H2S or thiophene and regeneration with syngas was investigated,the influence of carriers type and promoters type on thecatalysts' sulfur tolerance was analysis,the catalysts' structure and the reactants' chemical structureswere characterized based on various characterizations,and then the adsorption patterns and characteristics of sulfide on Pd metal active sides and acid active sides were revealed.Adsorption position of organic sulfur poisons and inorganic sulfur poisons on in CeO2-CaO-Pd/HZSM-5 catalyst was determined based on GC-MS,and thepossibletransformation mechanism of sulfides on catalyst were suggested. Finally,the kinetics of STD reaction over CeO2-CaO-Pd/HZSM-5 catalyst was researched.Because owing togood STD reactivity and sulfur tolerant,STD process conditions over CeO2-CaO-Pd/HZSM-5catalyst was further studied.The kinetic equations for STD reaction over CeO2-CaO-Pd/HZSM-5 catalyst in a fixed-bed reactor within the process conditions above were established

  5. Tailoring Pore Size of Nitrogen-Doped Hollow Carbon Nanospheres for Confi ning Sulfur in Lithium–Sulfur Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Weidong [General Motors Global Research and Development Center, Warren, MI (United States); Wang, Chong M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhang, Quiglin [General Motors Global Research and Development Center, Warren, MI (United States); Abruna, Hector D. [Cornell Univ., Ithaca, NY (United States); He, Yang [Univ. of Pittsburgh, PA (United States); Wang, Jiangwei [Univ. of Pittsburgh, PA (United States); Mao, Scott X. [Univ. of Pittsburgh, PA (United States); Xiao, Xingcheng [General Motors Global Research and Development Center, Warren, MI (United States)

    2015-08-19

    Three types of nitrogen-doped hollow carbon spheres with different pore sized porous shells are prepared to investigate the performance of sulfur confinement. The reason that why no sulfur is observed in previous research is determined and it is successfully demonstrated that the sulfur/polysulfide will overflow the porous carbon during the lithiation process.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Tamargo, Carlos E.; Montero-Alejo, Ana Lilian [Laboratory of Computational and Theoretical Chemistry (LQCT), Faculty of Chemistry, Havana University, Havana 10400 (Cuba); Pujals, Daniel Codorniu [Higher Institute of Technologies and Applied Sciences (InSTEC), Havana 10400 (Cuba); Mikosch, Hans [Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/E164-EC, 1060 Vienna (Austria); Hernández, Mayra P., E-mail: mayrap@imre.oc.uh.cu [Instituto de Ciencias y Tecnologías de Materiales (IMRE), Havana 10400 (Cuba)

    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.

  7. METHODOLOGICAL ASPECTS OF MOLASSES SAMPLE PREPARATION IN SULFUR DIOXIDE CONTENT DETERMINING

    Directory of Open Access Journals (Sweden)

    M. I. Egorova

    2015-01-01

    Full Text Available Summary. Molasses is characterized as sugar production by-product from primary or secondary sacchariferous raw materials. The features of the appearance, the chemical composition, molasses and exit directions of its use, depending on the type of production, in which it is formed. The value of molasses is demonstrated according to its total composition as well as its use directions. Statistics on beet molasses amounts in Russia is presented. Described consumer market molasses in Russia and abroad with its exports. Shown regulations contain requirements for the quality and safety of molasses, including sulfur dioxide. The data on sulfur allergenic properties are presented. Showing source of the sulfur dioxide in the residual molasses number of processing aids and the impact of its level in the value of raw molasses for use in biotechnological processes and fodder production. The necessity to develop methodology for determining the sulfur dioxide content in the molasses to control its security. The iodometric method, which is used in practice for determination of sulphur dioxide in foods are characterized. Differences molasses and sugar as objects of iodometric determination of sulfur dioxide, which leads to the inability to ascertain the equivalence point. The variants eliminate interfering background of dark-colored foods common in analytical chemistry. Advantages and disadvantages of the background masking and stripping the determination of sulfur dioxide in the darkcolored products. It was characterized by clarifying sugar solutions in optical control methods. The hypothesis about preferability of its use in sample molasses preparation for equivalence point fixation in iodometric titration is suggested. The tasks of experimental research for the development of sample preparation algorithm molasses in determining the content of sulphurous acid.

  8. Effects of sulfur on lead partitioning during sludge incineration based on experiments and thermodynamic calculations

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jing-yong, E-mail: www053991@126.com [School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Huang, Shu-jie; Sun, Shui-yu; Ning, Xun-an; He, Rui-zhe [School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Li, Xiao-ming [Guangdong Testing Institute of Product Quality Supervision, Guangzhou 510330 (China); Chen, Tao [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Luo, Guang-qian [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074 (China); Xie, Wu-ming; Wang, Yu-jie; Zhuo, Zhong-xu; Fu, Jie-wen [School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China)

    2015-04-15

    Highlights: • A thermodynamic equilibrium calculation was carried out. • Effects of three types of sulfurs on Pb distribution were investigated. • The mechanism for three types of sulfurs acting on Pb partitioning were proposed. • Lead partitioning and species in bottom ash and fly ash were identified. - Abstract: Experiments in a tubular furnace reactor and thermodynamic equilibrium calculations were conducted to investigate the impact of sulfur compounds on the migration of lead (Pb) during sludge incineration. Representative samples of typical sludge with and without the addition of sulfur compounds were combusted at 850 °C, and the partitioning of Pb in the solid phase (bottom ash) and gas phase (fly ash and flue gas) was quantified. The results indicate that three types of sulfur compounds (S, Na{sub 2}S and Na{sub 2}SO{sub 4}) added to the sludge could facilitate the volatilization of Pb in the gas phase (fly ash and flue gas) into metal sulfates displacing its sulfides and some of its oxides. The effect of promoting Pb volatilization by adding Na{sub 2}SO{sub 4} and Na{sub 2}S was superior to that of the addition of S. In bottom ash, different metallic sulfides were found in the forms of lead sulfide, aluminosilicate minerals, and polymetallic-sulfides, which were minimally volatilized. The chemical equilibrium calculations indicated that sulfur stabilizes Pb in the form of PbSO{sub 4}(s) at low temperatures (<1000 K). The equilibrium calculation prediction also suggested that SiO{sub 2}, CaO, TiO{sub 2}, and Al{sub 2}O{sub 3} containing materials function as condensed phase solids in the temperature range of 800–1100 K as sorbents to stabilize Pb. However, in the presence of sulfur or chlorine or the co-existence of sulfur and chlorine, these sorbents were inactive. The effect of sulfur on Pb partitioning in the sludge incineration process mainly depended on the gas phase reaction, the surface reaction, the volatilization of products, and the

  9. The Fate of Sulfur in Late-Stage Magmatic Processes: Insights From Quadruple Sulfur Isotopes

    Science.gov (United States)

    Keller, N. S.; Ono, S.; Shaw, A. M.

    2009-05-01

    Multiple sulfur isotopes (32S, 33S, 34S and 36S) have recently been shown to be useful tracers of fluid-rock interaction in seafloor hydrothermal systems [1]. Here we present the application of multiple sulfur isotopes to subaerial volcanoes with the aim of unraveling the various processes fractionating sulfur in the upper volcanic system. We take advantage of the fact that the ascent of volcanic gases through a hydrothermal system causes complex isotopic fractionation between the quaduple sulfur isotopes. δ34S is thought to trace the source of sulfur as well as magma degassing; at equilibrium, δ33S follows a mass-dependent fractionation relationship such that two phases in equilibrium with each other have equal Δ33S values (Δ33S ≡ ln(δ33S+1) - 0.515×ln(δ34S+1)). Disequilibrium Δ33S values can indicate isotope mixing and other fluid-rock interactions. The ultimate aim of this study is to assess the use of quadruple sulfur isotopes to obtain quantitative information on the sulfur cycle at convergent plate margins. The sulfur mass balance at convergent margins is poorly constrained, partly because late-stage processes are challenging to quantify and lead to large uncertainties in the global output fluxes. Quadruple sulfur isotopes provide a powerful tool to untangle the convoluted history of volcanic systems. Here we report the first quadruple sulfur isotopic values for H2S, SO2 and native sulfur from arc volcanoes. Fumarolic gases (˜100°C) and sulfur sublimates were collected from Poas and Turrialba, two actively degassing volcanoes in Costa Rica. The gases were bubbled in situ through chemical traps to separate H2S from SO2: H2S was reacted to form ZnS, and SO2 to form BaSO4. Sulfur was chemically extracted from the solid phases and precipitated as Ag2S, which was fluorinated to SF6 and analysed by IRMS. Poas and Turrialba have H2S/SO2 ˜1 and 0.01, respectively. δ34SH2S and δ34SSO2 are similar to gases measured at other arcs [2], - 7.9‰ and 0.6

  10. Sulfur Chemistry in Combustion II

    DEFF Research Database (Denmark)

    Johnsson, Jan Erik; Kiil, Søren

    2000-01-01

    Several options are available to control the emission of SO2 from combustion processes. One possibility is to use a cleaner technology, i.e. fuel switching from oil and coal to natural gas or biomass, or to desulphurize coal and oil. Another possibility is to change to a different technology for ...

  11. Experiments on contrail formation from fuels with different sulfur content

    Energy Technology Data Exchange (ETDEWEB)

    Busen, R.; Kuhn, M.; Petzold, A.; Schroeder, F.; Schumann, U. [Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt e.V., Oberpfaffenhofen (Germany); Baumgardner, D. [National Center for Atmospheric Research, Boulder, CO (United States); Borrmann, S. [Mainz Univ. (Germany); Hagen, D.; Whitefield, Ph. [Missouri Univ., Rolla, MO (United States). Bureau of Mines; Stroem, J. [Stockholm Univ. (Sweden)

    1997-12-31

    A series of both flight tests and ground experiments has been performed to evaluate the role of the sulfur contained in kerosene in condensation trail (contrail) formation processes. The results of the first experiments are compiled briefly. The last SULFUR 4 experiment dealing with the influence of the fuel sulfur content and different appertaining conditions is described in detail. Different sulfur mass fractions lead to different particle size spectra. The number of ice particles in the contrail increases by about a factor of 2 for 3000 ppm instead of 6 ppm sulfur fuel content. (author) 10 refs.

  12. Method to prevent sulfur accumulation in membrane electrode assembly

    Science.gov (United States)

    Steimke, John L; Steeper, Timothy J; Herman, David T

    2014-04-29

    A method of operating a hybrid sulfur electrolyzer to generate hydrogen is provided that includes the steps of providing an anolyte with a concentration of sulfur dioxide, and applying a current. During steady state generation of hydrogen a plot of applied current density versus concentration of sulfur dioxide is below a boundary line. The boundary line may be linear and extend through the origin of the graph with a slope of 0.001 in which the current density is measured in mA/cm2 and the concentration of sulfur dioxide is measured in moles of sulfur dioxide per liter of anolyte.

  13. Sulfur-graphene composite for rechargeable lithium batteries

    Science.gov (United States)

    Wang, Jia-Zhao; Lu, Lin; Choucair, Mohammad; Stride, John A.; Xu, Xun; Liu, Hua-Kun

    Sulfur-graphene (S-GNS) composites have been synthesized by heating a mixture of graphene nanosheets and elemental sulfur. According to field emission electron microscopy, scanning electron microscopy with energy dispersive X-ray mapping, Raman spectroscopy, and thermogravimetric analysis, sulfur particles were uniformly coated onto the surface of the graphene nanosheets. The electrochemical results show that the sulfur-graphene nanosheet composite significantly improved the electrical conductivity, the capacity, and the cycle stability in a lithium cell compared with the bare sulfur electrode.

  14. [Analysis of sulfur compounds in residue fluid catalytic cracking gasoline].

    Science.gov (United States)

    Liang, Yong-mei; Liu, Wen-hui; Liu, Yao-fang

    2002-05-01

    Sulfur compounds in residue fluid catalytic cracking (RFCC) gasolines from Refinery of SINOPEC Beijing Yanshan Company and Refinery of Shijiazhuang were analyzed by gas chromatograph connected with flame photometric detector (FPD) and atomic emission detector (AED). Twelve and 26 kinds of sulfur compounds were detected by AED in RFCC gasolines from Yanshan and Shijiazhuang respectively. Only 0 and 19 kinds of sulfur compounds were found by FPD in these two gasolines respectively. The experimental results demonstrated that AED is more sensitive and selective to sulfur compounds than FPD. It also indicated that thiophenes were the major sulfur compounds in the RFCC gasoline. In addition, mercaptan, sulfoether and disulfide species were found.

  15. Refined Sulfur Nanoparticles Immobilized in Metal-Organic Polyhedron as Stable Cathodes for Li-S Battery.

    Science.gov (United States)

    Bai, Linyi; Chao, Dongliang; Xing, Pengyao; Tou, Li Juan; Chen, Zhen; Jana, Avijit; Shen, Ze Xiang; Zhao, Yanli

    2016-06-15

    The lithium-sulfur (Li-S) battery presents a promising rechargeable energy storage technology for the increasing energy demand in a worldwide range. However, current main challenges in Li-S battery are structural degradation and instability of the solid-electrolyte interphase caused by the dissolution of polysulfides during cycling, resulting in the corrosion and loss of active materials. Herein, we developed novel hybrids by employing metal-organic polyhedron (MOP) encapsulated PVP-functionalized sulfur nanoparticles (S@MOP), where the active sulfur component was efficiently encapsulated within the core of MOP and PVP as a surfactant was helpful to stabilize the sulfur nanoparticles and control the size and shape of corresponding hybrids during their syntheses. The amount of sulfur embedded into MOP could be controlled according to requirements. By using the S@MOP hybrids as cathodes, an obvious enhancement in the performance of Li-S battery was achieved, including high specific capacity with good cycling stability. The MOP encapsulation could enhance the utilization efficiency of sulfur. Importantly, the structure of the S@MOP hybrids was very stable, and they could last for almost 1000 cycles as cathodes in Li-S battery. Such high performance has rarely been obtained using metal-organic framework systems. The present approach opens up a promising route for further applications of MOP as host materials in electrochemical and energy storage fields.

  16. Application of Near-Infrared Hyperspectral Imaging to Detect Sulfur Dioxide Residual in the Fritillaria thunbergii Bulbus Treated by Sulfur Fumigation

    Directory of Open Access Journals (Sweden)

    Juan He

    2017-01-01

    Full Text Available Sulfur-fumigated Chinese medicine is a common issue in the process of Chinese medicines. Detection of sulfur dioxide (SO2 residual content in Fritillaria thunbergii Bulbus is important to evaluate the degree of sulfur fumigation and its harms. It helps to control the use of sulfur fumigation in Fritillaria thunbergii Bulbus. Near-infrared hyperspectral imaging (NIR-HSI was explored as a rapid, non-destructive, and accurate technique to detect SO2 residual contents in Fritillaria thunbergii Bulbus. An HSI system covering the spectral range of 874–1734 nm was used. Partial least squares regression (PLSR was applied to build calibration models for SO2 residual content detection. Successive projections algorithm (SPA, weighted regression coefficients (Bw, random frog (RF, and competitive adaptive reweighted sampling (CARS were used to select optimal wavelengths. PLSR models using the full spectrum and the selected optimal wavelengths obtained good performance. The Bw-PLSR model was applied on a hyperspectral image to form a prediction map, and the results were satisfactory. The overall results in this study indicated that HSI could be used as a promising technique for on-line visualization and monitoring of SO2 residual content in Fritillaria thunbergii Bulbus. Detection and visualization of Chinese medicine quality by HSI provided a new rapid and visual method for Chinese medicine monitoring, showing great potential for real-world application.

  17. Transient Studies of a Sodium Sulfur Cell

    Science.gov (United States)

    Caprio, Sarah

    Modern grids will include input from fossil-fueled power generation facilities as well as renewable energy sources, and these are expected to work together actively. One major problem with this integrated power production is that most renewable energy sources are intermittent and variable, and thus introduce a very challenging situation with regard to grid stability and reliability. Also, fossil-fueled power generation facilities have load cycles based on expected usage. A non-reliable power source cannot feasibly be used to supply the grid with proper amounts of energy needed in peak times. A solution to this dilemma is power storage. The sodium-sulfur battery has high potential for electrical storage at the grid level due to its high energy density, low cost of the reactants, and high open-circuit voltage. However, the use of sodium-sulfur batteries at the grid level requires high current density operation that can cause cell deterioration, leading to lower sulfur utilization and lower energy efficiency. In addition, it can result in undesired thermal runaway leading to potentially hazardous situations. A rigorous, dynamic model of a sodium-sulfur battery can be used to study these phenomena, design the battery for optimal transient performance, and develop mitigation strategies. Most literature on sodium-sulfur batteries is concerned the dynamics of the sulfur electrode (a sodium-polysulfide melt). There is limited data in the open literature for dynamics of an entire cell. With this motivation, a first-principles dynamic model of a sodium-sulfur cell (with beta"-alumina electrolyte) has been developed. The state of discharge (SOD) of a sodium-sulfur cell significantly affects the heat generation rate, rates of electrochemical reactions, and internal resistance. To capture these phenomena correctly, a fully coupled thermal-electrochemical model has been developed. The thermal model considers heat generation due to Ohmic loss, Peltier heat, and heat due to the

  18. The fate of sulfur during rapid pyrolysis of scrap tires.

    Science.gov (United States)

    Hu, Hongyun; Fang, Yuan; Liu, Huan; Yu, Ren; Luo, Guangqian; Liu, Wenqiang; Li, Aijun; Yao, Hong

    2014-02-01

    The fate of sulfur during rapid pyrolysis of scrap tires at temperatures from 673 to 1073K was investigated. Sulfur was predominant in the forms of thiophenic and inorganic sulfides in raw scrap tires. In the pyrolysis process, sulfur in organic forms was unstable and decomposed, leading to the sulfur release into tar and gases. At 673 and 773K, a considerable amount of sulfur was distributed in tar. Temperature increasing from 773 to 973K promoted tar decomposition and facilitated sulfur release into gases. At 1073K, the interactions between volatiles and char stimulated the formation of high-molecular-weight sulfur-containing compounds. After pyrolysis, almost half of the total content of sulfur in raw scrap tires still remained in the char and was mostly in the form of sulfides. Moreover, at temperatures higher than 873K, part of sulfur in the char was immobilized in the sulfates. In the pyrolysis gases, H2S was the main sulfur-containing gas. Increasing temperature stimulated the decomposition of organic polymers in scrap tires and more H2S was formed. Besides H2S, other sulfur-containing gases such as CH3SH, COS and SO2 were produced during the rapid pyrolysis of scrap tires.

  19. Aerobic sulfur-oxidizing bacteria: Environmental selection and diversification

    Science.gov (United States)

    Caldwell, D.

    1985-01-01

    Sulfur-oxidizing bacteria oxidize reduced inorganic compounds to sulfuric acid. Lithotrophic sulfur oxidizer use the energy obtained from oxidation for microbial growth. Heterotrophic sulfur oxidizers obtain energy from the oxidation of organic compounds. In sulfur-oxidizing mixotrophs energy are derived either from the oxidation of inorganic or organic compounds. Sulfur-oxidizing bacteria are usually located within the sulfide/oxygen interfaces of springs, sediments, soil microenvironments, and the hypolimnion. Colonization of the interface is necessary since sulfide auto-oxidizes and because both oxygen and sulfide are needed for growth. The environmental stresses associated with the colonization of these interfaces resulted in the evolution of morphologically diverse and unique aerobic sulfur oxidizers.

  20. The Curious Conundrum Regarding Sulfur Abundances In Planetary Nebulae

    CERN Document Server

    Henry, R B C; Karakas, A I; Ferland, G J; Maguire, M

    2012-01-01

    Sulfur abundances derived from optical emission line measurements and ionization correction factors in planetary nebulae are systematically lower than expected for the objects' metallicities. We have carefully considered a large range of explanations for this "sulfur anomaly", including: (1) correlations between the size of the sulfur deficit and numerous nebular and central star properties; (2) ionization correction factors which under-correct for unobserved ions; (3) effects of dielectronic recombination on the sulfur ionization balance; (4) sequestering of S into dust and/or molecules; and (5) excessive destruction of S or production of O by AGB stars. It appears that all but the second scenario can be ruled out. However, we find evidence that the sulfur deficit is generally reduced but not eliminated when S^+3 abundances determined directly from IR measurements are used in place of the customary sulfur ionization correction factor. We tentatively conclude that the sulfur anomaly is caused by the inability...

  1. Large Sulfur Isotope Fractionation Does Not Require Disproportionation

    Science.gov (United States)

    Sim, Min Sub; Bosak, Tanja; Ono, Shuhei

    2011-07-01

    The composition of sulfur isotopes in sedimentary sulfides and sulfates traces the sulfur cycle throughout Earth’s history. In particular, depletions of sulfur-34 (34S) in sulfide relative to sulfate exceeding 47 per mil (‰) often serve as a proxy for the disproportionation of intermediate sulfur species in addition to sulfate reduction. Here, we demonstrate that a pure, actively growing culture of a marine sulfate-reducing bacterium can deplete 34S by up to 66‰ during sulfate reduction alone and in the absence of an extracellular oxidative sulfur cycle. Therefore, similar magnitudes of sulfur isotope fractionation in sedimentary rocks do not unambiguously record the presence of other sulfur-based metabolisms or the stepwise oxygenation of Earth’s surface environment during the Proterozoic.

  2. Large sulfur isotope fractionation does not require disproportionation.

    Science.gov (United States)

    Sim, Min Sub; Bosak, Tanja; Ono, Shuhei

    2011-07-01

    The composition of sulfur isotopes in sedimentary sulfides and sulfates traces the sulfur cycle throughout Earth's history. In particular, depletions of sulfur-34 ((34)S) in sulfide relative to sulfate exceeding 47 per mil (‰) often serve as a proxy for the disproportionation of intermediate sulfur species in addition to sulfate reduction. Here, we demonstrate that a pure, actively growing culture of a marine sulfate-reducing bacterium can deplete (34)S by up to 66‰ during sulfate reduction alone and in the absence of an extracellular oxidative sulfur cycle. Therefore, similar magnitudes of sulfur isotope fractionation in sedimentary rocks do not unambiguously record the presence of other sulfur-based metabolisms or the stepwise oxygenation of Earth's surface environment during the Proterozoic.

  3. Study on Effect of Compounding Sulfurized Isobutylene with Thioester

    Institute of Scientific and Technical Information of China (English)

    Li Hongjun; Qiu Yansheng

    2002-01-01

    Oxygen is introduced into the sulfurized isobutylene by compounding the sulfurized isobutylene with thioester. This paper studies the synergistic effect of commingling the sulfurized isobutylene with thioester during testing in the four-ball machine and the high-speed Timken machine. Tests in the four-ball machine and the high-speed Timken machine have revealed an improvement in EP performance of sulfurized isobutylene in admixture with thioester. The interfacial tension test and electrochemical analysis of anodic polarization have discovered increase of adsorptive force of the additive package on metal surface following compounding sulfurized isobutylene with thioester. The XPS and AES analyses indicate to the formation of FeS, Fe203 and FeSO4 on the metal surface. The sulfurized film formed by the additive package on the metal surface is thicker than that formed by simple sulfurized isobutylene.

  4. Graphene-Wrapped Sulfur Particles as a Rechargeable Lithium-Sulfur Battery Cathode Material with High Capacity and Cycling Stability

    Science.gov (United States)

    Wang, Hailiang; Yang, Yuan; Liang, Yongye; Robinson, Joshua Tucker; Li, Yanguang; Jackson, Ariel; Cui, Yi; Dai, Hongjie

    2011-07-01

    We report the synthesis of a graphene-sulfur composite material by wrapping polyethyleneglycol (PEG) coated submicron sulfur particles with mildly oxidized graphene oxide sheets decorated by carbon black nanoparticles. The PEG and graphene coating layers are important to accommodating volume expansion of the coated sulfur particles during discharge, trapping soluble polysulfide intermediates and rendering the sulfur particles electrically conducting. The resulting graphene-sulfur composite showed high and stable specific capacities up to ~600mAh/g over more than 100 cycles, representing a promising cathode material for rechargeable lithium batteries with high energy density.

  5. Sulfur radical species form gold deposits on Earth.

    Science.gov (United States)

    Pokrovski, Gleb S; Kokh, Maria A; Guillaume, Damien; Borisova, Anastassia Y; Gisquet, Pascal; Hazemann, Jean-Louis; Lahera, Eric; Del Net, William; Proux, Olivier; Testemale, Denis; Haigis, Volker; Jonchière, Romain; Seitsonen, Ari P; Ferlat, Guillaume; Vuilleumier, Rodolphe; Saitta, Antonino Marco; Boiron, Marie-Christine; Dubessy, Jean

    2015-11-01

    Current models of the formation and distribution of gold deposits on Earth are based on the long-standing paradigm that hydrogen sulfide and chloride are the ligands responsible for gold mobilization and precipitation by fluids across the lithosphere. Here we challenge this view by demonstrating, using in situ X-ray absorption spectroscopy and solubility measurements, coupled with molecular dynamics and thermodynamic simulations, that sulfur radical species, such as the trisulfur ion S3(-), form very stable and soluble complexes with Au(+) in aqueous solution at elevated temperatures (>250 °C) and pressures (>100 bar). These species enable extraction, transport, and focused precipitation of gold by sulfur-rich fluids 10-100 times more efficiently than sulfide and chloride only. As a result, S3(-) exerts an important control on the source, concentration, and distribution of gold in its major economic deposits from magmatic, hydrothermal, and metamorphic settings. The growth and decay of S3(-) during the fluid generation and evolution is one of the key factors that determine the fate of gold in the lithosphere.

  6. Accumulation of atmospheric sulfur in some Costa Rican soils

    Science.gov (United States)

    Bern, Carleton R.; Townsend, Alan R.

    2013-01-01

    Sulfur is one of the macronutrient elements whose sources to terrestrial ecosystems should shift from dominance by rock-weathering to atmospheric deposition as soils and underlying substrate undergo progressive weathering and leaching. However, the nature and timing of this transition is not well known. We investigated sources of sulfur to tropical rain forests growing on basalt-derived soils in the Osa Peninsula region of Costa Rica. Sulfur sources were examined using stable isotope ratios (δ34S) and compared to chemical indices of soil development. The most weathered soils, and the forests they supported, are dominated by atmospheric sulfur, while a less weathered soil type contains both rock-derived and atmospheric sulfur. Patterns of increasing δ34S with increasing soil sulfur concentration across the landscape suggest atmospheric sulfur is accumulating, and little rock-derived sulfur has been retained. Soil sulfur, minus adsorbed sulfate, is correlated with carbon and nitrogen, implying that sulfur accumulation occurs as plants and microbes incorporate sulfur into organic matter. Only the lower depth increments of the more weathered soils contained significant adsorbed sulfate. The evidence suggests a pattern of soil development in which sulfur-bearing minerals in rock, such as sulfides, weather early relative to other minerals, and the released sulfate is leached away. Sulfur added via atmospheric deposition is retained as organic matter accumulates in the soil profile. Adsorbed sulfate accumulates later, driven by changes in soil chemistry and mineralogy. These aspects of sulfur behavior during pedogenesis in this environment may hasten the transition to dominance by atmospheric sources.

  7. Are we getting enough sulfur in our diet?

    Directory of Open Access Journals (Sweden)

    Han Bo

    2007-11-01

    Full Text Available Abstract 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

  8. Distribution of Sulfur in Carbon/Sulfur Nanocomposites Analyzed by Small-Angle X-ray Scattering.

    Science.gov (United States)

    Petzold, Albrecht; Juhl, Anika; Scholz, Jonas; Ufer, Boris; Goerigk, Günter; Fröba, Michael; Ballauff, Matthias; Mascotto, Simone

    2016-03-22

    The analysis of sulfur distribution in porous carbon/sulfur nanocomposites using small-angle X-ray scattering (SAXS) is presented. Ordered porous CMK-8 carbon was used as the host matrix and gradually filled with sulfur (20-50 wt %) via melt impregnation. Owing to the almost complete match between the electron densities of carbon and sulfur, the porous nanocomposites present in essence a two-phase system and the filling of the host material can be precisely followed by this method. The absolute scattering intensities normalized per unit of mass were corrected accounting for the scattering contribution of the turbostratic microstructure of carbon and amorphous sulfur. The analysis using the Porod parameter and the chord-length distribution (CLD) approach determined the specific surface areas and filling mechanism of the nanocomposite materials, respectively. Thus, SAXS provides comprehensive characterization of the sulfur distribution in porous carbon and valuable information for a deeper understanding of cathode materials of lithium-sulfur batteries.

  9. Superior electrochemical performance of sulfur/graphene nanocomposite material for high-capacity lithium-sulfur batteries.

    Science.gov (United States)

    Wang, Bei; Li, Kefei; Su, Dawei; Ahn, Hyojun; Wang, Guoxiu

    2012-06-01

    Sulfur/graphene nanocomposite material has been prepared by incorporating sulfur into the graphene frameworks through a melting process. Field-emission scanning electron microscope analysis shows a homogeneous distribution of sulfur in the graphene nanosheet matrix. The sulfur/graphene nanocomposite exhibits a super-high lithium-storage capacity of 1580 mA h g(-1) and a satisfactory cycling performance in lithium-sulfur cells. The enhancement of the reversible capacity and cycle life could be attributed to the flexible graphene nanosheet matrix, which acts as a conducting medium and a physical buffer to cushion the volume change of sulfur during the lithiation and delithiation process. Graphene-based nanocomposites can significantly improve the electrochemical performance of lithium-sulfur batteries.

  10. Solvent extraction of elemental sulfur from coal and a determination of its source using stable sulfur isotopes

    Science.gov (United States)

    Hackley, Keith C.; Buchanan, D.H.; Coombs, K.; Chaven, C.; Kruse, C.W.

    1990-01-01

    Hot tetrachloroethene (perchloroethylene, PCE) extracts significant amounts of elemental sulfur (So) from weathered coals but not from pristine coals. The objective of this study was to determine whether So extracted by PCE is an oxidation product of pyrite or whether it originates in some way from unstable, organically-bound sulfur. The isotopic composition of the PCE-extracted So was compared to the isotopic compositions of the pyritic and the organic sulfur in a coal. The So was shown to have an isotopic signature similar to the pyritic sulfur. Additionally, the isotopic differences observed between the pyritic, So and sulfatic sulfur were consistent with bacterial mediated oxidation of sulfide sulfur (pyrite) as the source of both the sulfatic and elemental sulfur. ?? 1990.

  11. Sulfur isotopic composition and source identification of atmospheric environment in central Zhejiang,China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Sulfur dioxide and sulfate aerosols in the atmosphere are significant factors leading to acidification of the atmospheric environment and worsening the pollution of acid deposition. Because of the "fingerprint" characteristics of the stable sulfur isotopic composition, sulfur isotope has been widely adopted in environmental researches concerning sulfur cycle and source identification. In this study, the atmospheric environment of Jinhua City, central Zhejiang Province, was continuously monitored, and the sulfur isotopic composition of SO2 and sulfate aerosols in the atmosphere was analyzed. The results indicate that the variation of δ34S values for SO2 ranges from 1.0‰ to 7.5‰, and annual average is 4.7‰±2.3‰, whereas that of sulfate aerosols ranges from 6.4‰ to 9.8‰,and annual average is 8.1‰±1.0‰. The δ 34S values for SO2 have significant seasonal variations, which are 7.0‰ in winter and 3.3‰ in summer. These variations cannot be attributed to a single factor, and we suggest a temperature-dependent isotope equilibrium fractionation and elevated biogenic sulfur emissions of isotopically light S in summer may be the main controlling mechanisms. Furthermore, we also discuss the δ 34S model of atmospheric SO2 oxidation to form sulfate, and suggest that heterogeneous oxidation dominates in the oxidation reactions of atmospheric SO2 in the central Zhejiang Province. We further suggest that the relative humidity in the atmosphere plays an important role in the oxidation mechanism of atmospheric SO2.

  12. XAS spectroscopy, sulfur, and the brew within blood cells from Ascidia ceratodes.

    Science.gov (United States)

    Frank, Patrick; Hedman, Britt; Hodgson, Keith O

    2014-02-01

    We report the first use of K-edge X-ray absorption spectroscopy (XAS) as a direct spectroscopic probe of pH and cytosolic emf within living cells. A new accuracy metric of model-based fits to K-edge spectra is further developed. Sulfur functional groups in three collections of living blood cells and one sample of cleared blood plasma from the tunicate Ascidia ceratodes were speciated using K-edge XAS. Cysteine and cystine, the preferred thiol-disulfide model, averaged about 12% of total sulfur. Sulfate monoesters and cyclic diesters unexpectedly constituted 36% of blood cell sulfur. Soluble sulfate averaged about 25% across the three blood cell samples, while the ratio of SO4(2-) to HSO4(-) implied average signet ring vacuolar pH values of 0.85, 1.4, or 3.1. Intracellular (VSO4)(+) was unobserved, while [V(RSO3)n]((3-n)+) was detected in the two lowest pH blood cell samples. About 5% of sulfur was distributed as mono- or dibenzothiophene or ethylene-epi-sulfide, or as a thiadiazole reminiscent of the polycarpathiamines. Blood plasma was dominated by sulfate (83%), but with 15% of an alkylsulfate ester and about 2% of low-valent sulfur. Gravimetric analysis of soluble sulfate yielded average concentrations of blood cell sulfur. Average [cysteine] and [cystine] (ranging ~10-30 mM and ~20-90 mM, respectively) implied blood-cell cytosolic emf values of approximately -0.20 V. High cellular [cysteine] is consistent with the proposed model for enzymatic reduction of vanadate by endogenous thiol, wherein the trajectory of metal site-symmetry is controlled and directed through to a thermodynamically favored 7-coordinate V(III) product.

  13. Rapid organic matter sulfurization in sinking particles from the Cariaco Basin water column

    Science.gov (United States)

    Raven, Morgan Reed; Sessions, Alex L.; Adkins, Jess F.; Thunell, Robert C.

    2016-10-01

    Organic matter (OM) burial in marine sediments is a potentially important control on global climate and the long-term redox state of the earth's surface. Still, we have only a limited understanding of the processes that stabilize OM and facilitate its preservation in the geologic record. Abiotic reactions with (poly)sulfides can enhance the preservation potential of OM, but for this process to be significant it needs to compete with OM remineralization, the majority of which occurs before sinking particles reach the sea floor. Here we investigate whether OM sulfurization occurs within sinking particles in the Cariaco Basin, a modern sulfidic marine environment with high rates of OM burial. Proto-kerogen in sinking particles is frequently more sulfur-rich and 34S-depleted than expectations for biomass, with a composition that is difficult to explain by mixing with resuspended or terrigenous material. Instead, it appears that sulfur is being incorporated into OM on a timescale of days in sinking particles. The flux of this abiogenic organic S from particles is equivalent to approximately two-thirds of the total amount of proto-kerogen S at 10 cm depth in underlying sediments (ODP Core 1002B); after 6000 years of more gradual sulfurization reactions, potential water column sources are still equivalent to nearly half of the total proto-kerogen S in Cariaco sediments. Water column sulfurization is most extensive during periods of upwelling and high primary productivity and appears to involve elemental S, possibly via polysulfides. This process has the potential to deliver large amounts of OM to the sediments by making it less available for remineralization, generating OM-rich deposits. It represents a potentially dynamic sink in the global carbon cycle that can respond to changes in environmental conditions, including the size and intensity of O2-depleted environments. Water column OM sulfurization could also have played a more significant role in the carbon cycle

  14. Quantification of Sulfur in Mobility Fuels

    Science.gov (United States)

    2017-04-20

    containing compounds into sulfur monoxide, which then photochemically reacts with ozone (produced by a generator within the instrument 3 itself) to...with ozone to produce excited-state SO2. Therefore, in this study we will assess the UV fluorescence method carefully and determine if it has...to SO2 in the exhaust. In a separate set of experiments, an FTIR (Fourier transform infrared) spectrometer was used to analyze the combustion exhaust

  15. Surface Decontamination of Blister Agents Lewisite, Sulfur ...

    Science.gov (United States)

    Journal Article Sulfur mustard (HD) and Lewisite (L) are blister agents that have a high potential for terrorist use. Agent Yellow (HL) is the eutectic mixture of HD and L. Bench-scale testing was used to determine the residual amount of these chemical warfare agents remaining on three building materials coupons (wood, metal and glass) after application of various decontaminants (household bleach, full strength and dilute; hydrogen peroxide 3 % solution; and EasyDECON® DF200).

  16. Comparative analysis of the mechanisms of sulfur anion oxidation and reduction by dsr operon to maintain environmental sulfur balance.

    Science.gov (United States)

    Ghosh, Semanti; Bagchi, Angshuman

    2015-12-01

    Sulfur metabolism is one of the oldest known redox geochemical cycles in our atmosphere. These redox processes utilize different sulfur anions and the reactions are performed by the gene products of dsr operon from phylogenetically diverse sets of microorganisms. The operon is involved in the maintenance of environmental sulfur balance. Interestingly, the dsr operon is found to be present in both sulfur anion oxidizing and reducing microorganisms and in both types of organisms DsrAB protein complex plays a vital role. Though there are various reports regarding the genetics of dsr operon there are practically no reports dealing with the structural aspects of sulfur metabolism by dsr operon. In our present study, we tried to compare the mechanisms of sulfur anion oxidation and reduction by Allochromatium vinosum and Desulfovibrio vulgaris respectively through DsrAB protein complex. We analyzed the modes of bindings of sulfur anions to the DsrAB protein complex and observed that for sulfur anion oxidizers, sulfide and thiosulfate are the best substrates whereas for reducers sulfate and sulfite have the best binding abilities. We analyzed the binding interaction pattern of the DsrA and DsrB proteins while forming the DsrAB protein complexes in Desulfovibrio vulgaris and Allochromatium vinosum. To our knowledge this is the first report that analyzes the differences in binding patterns of sulfur substrates with DsrAB protein from these two microorganisms. This study would therefore be essential to predict the biochemical mechanism of sulfur anion oxidation and reduction by these two microorganisms i.e., Desulfovibrio vulgaris (sulfur anion reducer) and Allochromatium vinosum (sulfur anion oxidizer). Our observations also highlight the mechanism of sulfur geochemical cycle which has important implications in future study of sulfur metabolism as it has a huge application in waste remediation and production of industrial bio-products viz. vitamins, bio-polyesters and bio-hydrogen.

  17. ydjN encodes an S-sulfocysteine transporter required by Escherichia coli for growth on S-sulfocysteine as a sulfur source.

    Science.gov (United States)

    Yamazaki, Shunsuke; Takei, Kensuke; Nonaka, Gen

    2016-09-01

    Sulfur is an essential element for growth and many physiological functions. As sulfur sources for Escherichia coli and related bacteria, specific transporters import various sulfur-containing compounds from the environment. In this study, we identified and characterized an alternative function of the cystine transporter YdjN in E. coli as a transporter of S-sulfocysteine, a sulfur-containing intermediate in the assimilatory cysteine biosynthesis that is used as a sulfur source for the growth of E. coli We also demonstrated that the transport of S-sulfocysteine via YdjN depends on the transcriptional regulator CysB, a master regulator that controls most of the genes involved in sulfur assimilation and cysteine metabolism. We found that the use of S-sulfocysteine as a sulfur source depends on glutathione because mutations in glutathione biosynthetic genes abolish growth when S-sulfocysteine is used as a sole sulfur source, thereby supporting the previous findings that the conversion of S-sulfocysteine to cysteine is catalyzed by glutaredoxins. To the best of our knowledge, this is the first report of a functional S-sulfocysteine transporter across organisms, which strongly supports the hypothesis that S-sulfocysteine is not only a metabolic intermediate but also a physiologically significant substance in specific natural environments.

  18. Ordered mesoporous carbon/sulfur nanocomposite of high performances as cathode for lithium-sulfur battery

    Energy Technology Data Exchange (ETDEWEB)

    Chen Shuru [State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, School of Energy Research, Xiamen University, Xiamen 361005 (China); Zhai Yunpu [Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, and Advanced Materials Laboratory, Fudan University, Shanghai 200433 (China); Xu Guiliang; Jiang Yanxia [State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, School of Energy Research, Xiamen University, Xiamen 361005 (China); Zhao Dongyuan, E-mail: dyzhao@fudan.edu.cn [Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, and Advanced Materials Laboratory, Fudan University, Shanghai 200433 (China); Li Juntao; Huang Ling [State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, School of Energy Research, Xiamen University, Xiamen 361005 (China); Sun Shigang, E-mail: sgsun@xmu.edu.cn [State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, School of Energy Research, Xiamen University, Xiamen 361005 (China)

    2011-11-01

    Ordered mesoporous carbon/sulfur (OMC/S) nanocomposites with hierarchically structured sulfur loading, ranging from 50 to 75 wt%, were synthesized via a simple melt-diffusion strategy. The OMC with a BET surface area of 2102 m{sup 2} g{sup -1}, a pore volume of 2.0 cm{sup 3} g{sup -1} and unique bimodal mesoporous (5.6/2.3 nm) structure, was prepared from a triconstituent co-assembly method. The resulting OMC/S nanocomposite material served as cathode of rechargeable lithium-sulfur (Li-S) battery. It has been tested that the novel OMC/S cathode can deliver a superior reversible capacity and cyclability. In particular, the nanocomposite with a loading of 60 wt% sulfur (OMC/S-60) presents the highest sulfur utilization ca. 70%, an excellent high rate capability ca. 6 C and a good cycling stability for up to 400 full charge-discharge cycles. The exceptional electrochemical performances are exclusively attributed to the large internal surface area and high porosity of the ordered mesoporous carbon, which favorites both electron and Li-ion transportations.

  19. Biomimetic Ant-Nest Electrode Structures for High Sulfur Ratio Lithium-Sulfur Batteries.

    Science.gov (United States)

    Ai, Guo; Dai, Yiling; Mao, Wenfeng; Zhao, Hui; Fu, Yanbao; Song, Xiangyun; En, Yunfei; Battaglia, Vincent S; Srinivasan, Venkat; Liu, Gao

    2016-09-14

    The lithium-sulfur (Li-S) rechargeable battery has the benefit of high gravimetric energy density and low cost. Significant research currently focuses on increasing the sulfur loading and sulfur/inactive-materials ratio, to improve life and capacity. Inspired by nature's ant-nest structure, this research results in a novel Li-S electrode that is designed to meet both goals. With only three simple manufacturing-friendly steps, which include slurry ball-milling, doctor-blade-based laminate casting, and the use of the sacrificial method with water to dissolve away table salt, the ant-nest design has been successfully recreated in an Li-S electrode. The efficient capabilities of the ant-nest structure are adopted to facilitate fast ion transportation, sustain polysulfide dissolution, and assist efficient precipitation. High cycling stability in the Li-S batteries, for practical applications, has been achieved with up to 3 mg·cm(-2) sulfur loading. Li-S electrodes with up to a 85% sulfur ratio have also been achieved for the efficient design of this novel ant-nest structure.

  20. Sulfur isotopes in coal constrain the evolution of the Phanerozoic sulfur cycle.

    Science.gov (United States)

    Canfield, Donald E

    2013-05-21

    Sulfate is the second most abundant anion (behind chloride) in modern seawater, and its cycling is intimately coupled to the cycling of organic matter and oxygen at the Earth's surface. For example, the reduction of sulfide by microbes oxidizes vast amounts of organic carbon and the subsequent reaction of sulfide with iron produces pyrite whose burial in sediments is an important oxygen source to the atmosphere. The concentrations of seawater sulfate and the operation of sulfur cycle have experienced dynamic changes through Earth's history, and our understanding of this history is based mainly on interpretations of the isotope record of seawater sulfates and sedimentary pyrites. The isotope record, however, does not give a complete picture of the ancient sulfur cycle. This is because, in standard isotope mass balance models, there are more variables than constraints. Typically, in interpretations of the isotope record and in the absence of better information, one assumes that the isotopic composition of the input sulfate to the oceans has remained constant through time. It is argued here that this assumption has a constraint over the last 390 Ma from the isotopic composition of sulfur in coal. Indeed, these compositions do not deviate substantially from the modern surface-water input to the oceans. When applied to mass balance models, these results support previous interpretations of sulfur cycle operation and counter recent suggestions that sulfate has been a minor player in sulfur cycling through the Phanerozoic Eon.

  1. Sulfur/three-dimensional graphene composite for high performance lithium-sulfur batteries

    Science.gov (United States)

    Xu, Chunmei; Wu, Yishan; Zhao, Xuyang; Wang, Xiuli; Du, Gaohui; Zhang, Jun; Tu, Jiangping

    2015-02-01

    A sulfur/graphene composite is prepared by loading elemental sulfur into three-dimensional graphene (3D graphene), which is assembled using a metal ions assisted hydrothermal method. When used as cathode materials for lithium-sulfur (Li-S) batteries, the sulfur/graphene composite (S@3D-graphene) with 73 wt % sulfur shows a significantly enhanced cycling performance (>700 mAh g-1 after 100 cycles at 0.1C rate with a Coulombic efficiency > 96%) as well as high rate capability with a capacity up to 500 mAh g-1 at 2C rate (3.35 A g-1). The superior electrochemical performance could be attributed to the highly porous structure of three-dimensional graphene that not only enables stable and continue pathway for rapid electron and ion transportation, but also restrain soluble polysulfides and suppress the "shuttle effect". Moreover, the robust structure of 3D graphene can keep cathode integrity and accommodate the volume change during high-rate charge/discharge processes, making it a promising candidate as cathode for high performance Li-S batteries.

  2. Formation of CuxS Layers on Polypropylene Sulfurized by Molten Sulfur

    Directory of Open Access Journals (Sweden)

    Rasa ALABURDAITĖ

    2011-11-01

    Full Text Available The processes of formation of electrically conductive layers of copper sulfides CuxS by the sorption-diffusion method on polypropylene (PP using molten sulfur as sulfurizing agent was investigated. The amount of sorbed sulfur increased with the increase of the duration of treatment. Copper sulfide layers were formed on the surface of polypropylene after the treatment of sulfurized polymer with Cu(II/I salt solution. The amount of copper sulfide in layer increased with the increase of treatment duration in copper salt solution. XRD spectra of PP films treated for 3 min with molten sulfur and then with Cu(II/I salt solution for the different time showed that the copper sulfide phases, mostly digenite, Cu2-xS and a-chalcocite, Cu2S were formed in the layers. Electromotive force measurement results confirmed the composition of formed CuxS layers on PP. The phase composition of layers also changed after the annealing. The value of electrical resistance of copper sulfide layers on PP varied from 20 W/cm2 to 80 W/cm2 and after annealing at 80 °C - in the interval of 10 W/cm2 - 60 W/cm2.http://dx.doi.org/10.5755/j01.ms.17.4.776

  3. A composite of hollow carbon nanospheres and sulfur-rich polymers for lithium-sulfur batteries

    Science.gov (United States)

    Zeng, Shao-Zhong; Yao, Yuechao; Zeng, Xierong; He, Qianjun; Zheng, Xianfeng; Chen, Shuangshuang; Tu, Wenxuan; Zou, Jizhao

    2017-07-01

    Lithium-sulfur batteries are the most promising candidates for future high-energy applications because of the unparalleled capacity of sulfur (1675 mAh g-1). However, lithium-sulfur batteries have limited cycle life and rate capability due to the dissolution of polysulfides and the extremely low electronic conductivity of sulfur. To solve these issues, various porous carbons including hollow carbon nanospheres (HCNs) have been used for improving the conductivity. However, these methods still suffer from polysulfides dissolution/loss owing to their weak physical adsorption to polysulfides. Herein, we introduced a covalent grafting route to composite the HCNs and the vulcanized trithiocyanuric acid (TTCA). The composite exhibits a high loading of the vulcanized TTCA by the HCNs with high surface area and large pore volume, and covalent bonds to sulfur, effectively depressing the dissolution of polysulfides. The first discharge capacity of the composite reaches 1430 mAh g-1 at 0.1 C and 1227 mAh g-1 at 0.2 C.

  4. Formation of CuxS Layers on Polypropylene Sulfurized by Molten Sulfur

    Directory of Open Access Journals (Sweden)

    Rasa ALABURDAITĖ

    2011-11-01

    Full Text Available The processes of formation of electrically conductive layers of copper sulfides CuxS by the sorption-diffusion method on polypropylene (PP using molten sulfur as sulfurizing agent was investigated. The amount of sorbed sulfur increased with the increase of the duration of treatment. Copper sulfide layers were formed on the surface of polypropylene after the treatment of sulfurized polymer with Cu(II/I salt solution. The amount of copper sulfide in layer increased with the increase of treatment duration in copper salt solution. XRD spectra of PP films treated for 3 min with molten sulfur and then with Cu(II/I salt solution for the different time showed that the copper sulfide phases, mostly digenite, Cu2-xS and a-chalcocite, Cu2S were formed in the layers. Electromotive force measurement results confirmed the composition of formed CuxS layers on PP. The phase composition of layers also changed after the annealing. The value of electrical resistance of copper sulfide layers on PP varied from 20 W/cm2 to 80 W/cm2 and after annealing at 80 °C - in the interval of 10 W/cm2 - 60 W/cm2.http://dx.doi.org/10.5755/j01.ms.17.4.776

  5. Minimal sulfur requirement for growth and sulfur-dependent metabolism of the hyperthermophilic archaeon Staphylothermus marinus

    Directory of Open Access Journals (Sweden)

    Xiaolei Hao

    2003-01-01

    Full Text Available Staphylothermus marinus is an anaerobic hyperthermophilic archaeon that uses peptides as carbon and energy sources. Elemental sulfur (S° is obligately required for its growth and is reduced to H2S. The metabolic functions and mechanisms of S° reduction were explored by examining S°-dependent growth and activities of key enzymes present in this organism. All three forms of S° tested—sublimed S°, colloidal S° and polysulfide—were used by S. marinus, and no other sulfur-containing compounds could replace S°. Elemental sulfur did not serve as physical support but appeared to function as an electron acceptor. The minimal S° concentration required for optimal growth was 0.05% (w/v. At this concentration, there appeared to be a metabolic transition from H2 production to S° reduction. Some enzymatic activities related to S°-dependent metabolism, including sulfur reductase, hydrogenase, glutamate dehydrogenase and electron transfer activities, were detected in cell-free extracts of S. marinus. These results indicate that S° plays an essential role in the heterotrophic metabolism of S. marinus. Reducing equivalents generated by the oxidation of amino acids from peptidolysis may be transferred to sulfur reductase and hydrogenase, which then catalyze the production of H2S and H2, respectively.

  6. Sulfur biogeochemistry of oil sands composite tailings

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Lesley; Stephenson, Kate [Earth Sciences, McMaster University (Canada)], email: warrenl@mcmaster.ca; Penner, Tara [Syncrude Environmental Research (Canada)

    2011-07-01

    This paper discusses the sulfur biogeochemistry of oil sands composite tailings (CT). The Government of Alberta is accelerating reclamation activities on composite tailings. As a CT pilot reclamation operation, Syncrude is currently constructing the first freshwater fen. Minor unpredicted incidents with H2S gas released from the dewatering process associated with these reclamations have been reported. The objective of this study is to ascertain the connection between microbial activity and H2S generation within CT and to assess the sulfur biogeochemistry of untreated and treated (fen) CT over seasonal and annual timescales. The microbial geochemical interactions taking place are shown using a flow chart. CT is composed of gypsum, sand, clay and organics like naphthenic acids and bitumen. Sulfur and Fe cycling in mining systems and their microbial activities are presented. The chemistry and the processes involved within CT are also given along with the results. It can be said that the diverse Fe and S metabolizing microorganisms confirm the ecology involved in H2S dynamics.

  7. Development of the Hybrid Sulfur Thermochemical Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Summers, William A.; Steimke, John L

    2005-09-23

    The production of hydrogen via the thermochemical splitting of water is being considered as a primary means for utilizing the heat from advanced nuclear reactors to provide fuel for a hydrogen economy. The Hybrid Sulfur (HyS) Process is one of the baseline candidates identified by the U.S. Department of Energy [1] for this purpose. The HyS Process is a two-step hybrid thermochemical cycle that only involves sulfur, oxygen and hydrogen compounds. Recent work has resulted in an improved process design with a calculated overall thermal efficiency (nuclear heat to hydrogen, higher heating value basis) approaching 50%. Economic analyses indicate that a nuclear hydrogen plant employing the HyS Process in conjunction with an advanced gas-cooled nuclear reactor system can produce hydrogen at competitive prices. Experimental work has begun on the sulfur dioxide depolarized electrolyzer, the major developmental component in the cycle. Proof-of-concept tests have established proton-exchange-membrane cells (a state-of-the-art technology) as a viable approach for conducting this reaction. This is expected to lead to more efficient and economical cell designs than were previously available. Considerable development and scale-up issues remain to be resolved, but the development of a viable commercial-scale HyS Process should be feasible in time to meet the commercialization schedule for Generation IV gas-cooled nuclear reactors.

  8. Biological effects data: Fluoride and sulfur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    McMechan, K.J. (ed.); Holton, R.L.; Ulbricht, R.J.; Morgan , J.B.

    1975-04-01

    The Alumax Pacific Aluminum Corporation has proposed construction of an aluminum reduction facility near Youngs Bay at Warrenton, Oregon. This report comprises one part of the final report to Alumax on a research project entitled, Physical, Chemical and Biological Studies of Youngs Bay.'' It presents data pertaining to the potential biological effects of fluoride and sulfur dioxide, two potentially hazardous plant-stack emissions, on selected aquatic species of the area. Companion volumes provide a description of the physical characteristics the geochemistry, and the aquatic animals present in Youngs Bay and adjacent ecosystems. An introductory volume provides general information and maps of the area, and summarizes the conclusions of all four studies. The data from the two phases of the experimental program are included in this report: lethal studies on the effects of selected levels of fluoride and sulfur dioxide on the survival rate of eleven Youngs Bay faunal species from four phyla, and sublethal studies on the effects of fluoride and sulfur dioxide on the rate of primary production of phytoplankton. 44 refs., 18 figs., 38 tabs.

  9. Sulfur aerosol in the clouds of Venus

    Science.gov (United States)

    Krasnopolsky, Vladimir A.

    2016-08-01

    The photochemical model for the middle atmosphere of Venus (Krasnopolsky, V.A. [2012] Icarus, 218, 230-246) predicts sulfur aerosol as a product of the OCS photolysis at 55-60 km. The calculated mass loading is much smaller than that of the mode 1 particles in the upper cloud layer. The chemical kinetic model for the lower atmosphere (Krasnopolsky, V.A. [2013], Icarus, 225, 570-580) results in a constant mixing ratio of 20 ppm for OCS + XSX. This means the S8 mixing ratio of 2.5 ppm near the model upper boundary at 47 km. Using this abundance, the calculated profile of the sulfur aerosol has a bottom that coincides with the lower boundary of modes 2 and 3 and constitutes ∼10% of the total mass loading in the lower cloud layer. Sulfur aerosol cannot be the near UV absorber because its abundance is too low at the cloud tops and disagrees with the profile of the absorber observed by Venera 14.

  10. Global sulfur emissions from 1850 to 2000.

    Science.gov (United States)

    Stern, David I

    2005-01-01

    The ASL database provides continuous time-series of sulfur emissions for most countries in the World from 1850 to 1990, but academic and official estimates for the 1990s either do not cover all years or countries. This paper develops continuous time series of sulfur emissions by country for the period 1850-2000 with a particular focus on developments in the 1990s. Global estimates for 1996-2000 are the first that are based on actual observed data. Raw estimates are obtained in two ways. For countries and years with existing published data I compile and integrate that data. Previously published data covers the majority of emissions and almost all countries have published emissions for at least 1995. For the remaining countries and for missing years for countries with some published data, I interpolate or extrapolate estimates using either an econometric emissions frontier model, an environmental Kuznets curve model, or a simple extrapolation, depending on the availability of data. Finally, I discuss the main movements in global and regional emissions in the 1990s and earlier decades and compare the results to other studies. Global emissions peaked in 1989 and declined rapidly thereafter. The locus of emissions shifted towards East and South Asia, but even this region peaked in 1996. My estimates for the 1990s show a much more rapid decline than other global studies, reflecting the view that technological progress in reducing sulfur based pollution has been rapid and is beginning to diffuse worldwide.

  11. Effects of sulfur plus resin-coated controlled release urea fertilizer on winter wheat dry matter accumulation and allocation and grain yield%硫加树脂包膜尿素控释肥对小麦干物质积累分配及产量的影响

    Institute of Scientific and Technical Information of China (English)

    满建国; 周杰; 王东; 于振文; 张民; 胡志颖; 侯秀涛

    2011-01-01

    A field experiment was conducted to study the effects of sulfur plus resin-coated urea fertilizer on the winter wheat dry matter accumulation and allocation and grain yield. Four treatments were installed, i. e. , sulfur plus resin-coated urea (SRCU), resin-coated urea (RCU), sulfuramended conventional urea (SU), and conventional urea (U). The coated urea fertilizers were applied as basal, and the conventional urea fertilizers were 50% applied as basal and 50% applied as topdressing. There were no significant differences in the plant dry matter accumulation and grain yield between treatments RCU and U. Under the conditions the available S content in 0-20 cm soil layer was 43.2 mg · kg-1 and the S application rate was 91.4 kg · hm-2, treatments SRCU and SU had no significant differences in the dry matter accumulation and allocation after anthesis and the grain yield, but the amount of the assimilates after anthesis allocated in grain, the grain-filling rate at mid grain-filling stage, the 1000-grain weight, and the grain yield in the two treatments were significantly higher than those in treatment RCU. When the available S content in 0-20 cm soil layer was 105.1 mg · kg-1 and the S application rate was 120 kg · hm-2 , the grain yield in treatment SRCU was significantly higher than that in treatment SU, but had no significant difference with that in treatments RCU and U. These results suggested that from the viewpoints of dry matter accumulation and allocation and grain yield, the nitrogen released from SRCU had the same regulation effect as the conventional urea 50% applied as basal and 50% applied as topdressing, while the regulation effect of the sulfur released from SRCU was controlled by the available S content in 0-20 cm soil layer. When the soil available S content was 43.2 mg · kg-1 , the released sulfur could promote the dry matter accumulation after anthesis and the grain-filling, and increase the grain yield significantly; when the soil

  12. Geochemistry of sulfur in the Florida Everglades; 1994 through 1999

    Science.gov (United States)

    Bates, Anne L.; Orem, W.H.; Harvey, J.W.; Spiker, E. C.

    2000-01-01

    In this report, we present data on the geochemistry of sulfur in sediments and in surface water, groundwater, and rainwater in the Everglades region in south Florida. The results presented here are part of a larger study intended to determine the roles played by the cycling of carbon, nitrogen, phosphorus, and sulfur in the ecology of the south Florida wetlands. The geochemistry of sulfur in the region is particularly important because of its link to the production of toxic methylmercury through processes mediated by sulfate reducing bacteria. Sediment cores were collected from the Everglades Agricultural Area (EAA), Water Conservation Areas (WCAs) 1A and 2A, from Lake Okeechobee, and from Taylor Slough in the southern Everglades. Water collection was more widespread and includes surface water from WCAs 1A, 2A, 3A, 2B, the EAA, Taylor Slough, Lake Okeechobee, and the Kissimmee River. Groundwater was collected from The Everglades Nutrient Removal Area (ENR) and from WCA 2A. Rainwater was collected at two month intervals over a period of one year from the ENR and from WCA 2A. Water was analyzed for sulfate concentration and sulfate sulfur stable isotopic ratio (34S/32S). Sediment cores were analyzed for total sulfur concentration and/or for concentrations of sulfur species (sulfate, organic sulfur, disulfides, and acid volatile sulfides (AVS)) and for their stable sulfur isotopic ratio. Results show a decrease in total sulfur content (1.57 to 0.61 percent dry weight) with depth in two sediment cores collected in WCA 2A, indicating that there has been an increase in total sulfur content in recent times. A sediment core from the center of Lake Okeechobee shows a decrease in total sulfur content with depth (0.28 to 0.08 percent dry weight). A core from the periphery of the lake (South Bay) likewise shows a decrease in total sulfur content with depth (1.00 to 0.69 percent dry weight), however, the overall sulfur content is greater than that near the center at all depths

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

    Science.gov (United States)

    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.

  14. The analysis of thermoplastic characteristics of special polymer sulfur composite

    Science.gov (United States)

    Książek, Mariusz

    2017-01-01

    Specific chemical environments step out in the industry objects. Portland cement composites (concrete and mortar) were impregnated by using the special polymerized sulfur and technical soot as a filler (polymer sulfur composite). Sulfur and technical soot was applied as the industrial waste. Portland cement composites were made of the same aggregate, cement and water. The process of special polymer sulfur composite applied as the industrial waste is a thermal treatment process in the temperature of about 150-155°C. The result of such treatment is special polymer sulfur composite in a liquid state. This paper presents the plastic constants and coefficients of thermal expansion of special polymer sulfur composites, with isotropic porous matrix, reinforced by disoriented ellipsoidal inclusions with orthotropic symmetry of the thermoplastic properties. The investigations are based on the stochastic differential equations of solid mechanics. A model and algorithm for calculating the effective characteristics of special polymer sulfur composites are suggested. The effective thermoplastic characteristics of special polymer sulfur composites, with disoriented ellipsoidal inclusions, are calculated in two stages: First, the properties of materials with oriented inclusions are determined, and then effective constants of a composite with disoriented inclusions are determined on the basis of the Voigt or Rice scheme. A brief summary of new products related to special polymer sulfur composites is given as follows: Impregnation, repair, overlays and precast polymer concrete will be presented. Special polymer sulfur as polymer coating impregnation, which has received little attention in recent years, currently has some very interesting applications.

  15. The analysis of thermoplastic characteristics of special polymer sulfur composite

    Science.gov (United States)

    Książek, Mariusz

    2016-07-01

    Specific chemical environments step out in the industry objects. Portland cement composites (concrete and mortar) were impregnated by using the special polymerized sulfur and technical soot as a filler (polymer sulfur composite). Sulfur and technical soot was applied as the industrial waste. Portland cement composites were made of the same aggregate, cement and water. The process of special polymer sulfur composite applied as the industrial waste is a thermal treatment process in the temperature of about 150-155°C. The result of such treatment is special polymer sulfur composite in a liquid state. This paper presents the plastic constants and coefficients of thermal expansion of special polymer sulfur composites, with isotropic porous matrix, reinforced by disoriented ellipsoidal inclusions with orthotropic symmetry of the thermoplastic properties. The investigations are based on the stochastic differential equations of solid mechanics. A model and algorithm for calculating the effective characteristics of special polymer sulfur composites are suggested. The effective thermoplastic characteristics of special polymer sulfur composites, with disoriented ellipsoidal inclusions, are calculated in two stages: First, the properties of materials with oriented inclusions are determined, and then effective constants of a composite with disoriented inclusions are determined on the basis of the Voigt or Rice scheme. A brief summary of new products related to special polymer sulfur composites is given as follows: Impregnation, repair, overlays and precast polymer concrete will be presented. Special polymer sulfur as polymer coating impregnation, which has received little attention in recent years, currently has some very interesting applications.

  16. Corrosion Enhanced Enrichment of Sulfur and Implications for Alloy 22

    Energy Technology Data Exchange (ETDEWEB)

    Jones, R H; Baer, D R; Windisch Jr., C F; Rebak, R B

    2005-11-15

    The uniform corrosion rate of Alloy 22 will define the lifetime of a component such as a waste container if all other degradation modes are not operative. This represents the best-case scenario because the experimentally determined uniform corrosion rates from multi-year tests is 0.01 {micro}m/yr or 0.1 mm in 10,000 years. This lifetime depends on the stability of the passive film over the lifetime of the container; however, this stability is unknown. One potential breakdown mechanism is corrosion-enhanced enrichment of sulfur to the surface leading to sulfur induced breakdown of the passive film. There are numerous studies that confirm that sulfur causes passive film breakdown in nickel based alloys and evidence exists for corrosion enhanced enrichment of sulfur in nickel and nickel alloys. However, neither sulfur enrichment nor sulfur induced breakdown of the passive film on Alloy 22 has been demonstrated. The results of preliminary studies suggest sulfur enrichment does occur at the alloy surface and that sulfur shifts the corrosion potential to more active potentials. No clear affect of sulfur was noted on the corrosion rate but the sulfur concentrations were about only 2-3% of a monolayer, well below the concentrations that are possible.

  17. Sulfur formation and recovery in a thiosulfate-oxidizing bioreactor.

    Science.gov (United States)

    González-Sánchez, A; Meulepas, R; Revah, S

    2008-08-01

    This work describes the design and performance of a thiosulfate-oxidizing bioreactor that allowed high elemental sulfur production and recovery efficiency. The reactor system, referred to as a Supernatant-Recycling Settler Bioreactor (SRSB), consisted of a cylindrical upflow reactor and a separate aeration vessel. The reactor was equipped with an internal settler and packing material (structured corrugated PVC sheets) to facilitate both cell retention and the settling of the formed elemental sulfur. The supernatant from the reactor was continuously recirculated through the aerator. An inlet thiosulfate concentration of 100 mmol l(-1) was used. The reactor system was fed with 89 mmol l(-1) d(-1) thiosulfate reaching 98 to 100% thiosulfate conversion with an elemental sulfur yield of 77%. Ninety-three percent of the produced sulfur was harvested from the bottom of the reactor as sulfur sludge. The dry sulfur sludge contained 87% elemental sulfur. The inclusion of an internal settler and packing material in the reactor system resulted in an effective retention of sulfur and biomass inside the bioreactor, preventing the oxidation of thiosulfate and elemental sulfur to sulfate in the aerator and, therefore, improving the efficiency of elemental sulfur formation and recovery.

  18. Towards Stable Lithium-Sulfur Batteries with a Low Self-Discharge Rate: Ion Diffusion Modulation and Anode Protection.

    Science.gov (United States)

    Xu, Wen-Tao; Peng, Hong-Jie; Huang, Jia-Qi; Zhao, Chen-Zi; Cheng, Xin-Bing; Zhang, Qiang

    2015-09-01

    The self-discharge of a lithium-sulfur cell decreases the shelf-life of the battery and is one of the bottlenecks that hinders its practical applications. New insights into both the internal chemical reactions in a lithium-sulfur system and effective routes to retard self-discharge for highly stable batteries are crucial for the design of lithium-sulfur cells. Herein, a lithium-sulfur cell with a carbon nanotube/sulfur cathode and lithium-metal anode in lithium bis(trifluoromethanesulfonyl)imide/1,3-dioxolane/dimethyl ether electrolyte was selected as the model system to investigate the self-discharge behavior. Both lithium anode passivation and polysulfide anion diffusion suppression strategies are applied to reduce self-discharge of the lithium-sulfur cell. When the lithium-metal anode is protected by a high density passivation layer induced by LiNO3 , a very low shuttle constant of 0.017 h(-1) is achieved. The diffusion of the polysulfides is retarded by an ion-selective separator, and the shuttle constants decreased. The cell with LiNO3 additive maintained a discharge capacity of 97 % (961 mAh g(-1) ) of the initial capacity after 120 days at open circuit, which was around three times higher than the routine cell (32 % of initial capacity, corresponding to 320 mAh g(-1) ). It is expected that lithium-sulfur batteries with ultralow self-discharge rates may be fabricated through a combination of anode passivation and polysulfide shuttle control, as well as optimization of the lithium-sulfur cell configuration.

  19. 40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).

    Science.gov (United States)

    2010-07-01

    ... concentrates through the use of pyrometallurgical techniques. (viii) Process means any source operation... V, 230 South Dearborn, Chicago, Illinois, 60604, Attention Air Compliance Section. (5) For purposes... Plant shall keep a permanent log on the lock-out system and record any problems with the system in...

  20. EFFECT OF SOIL SULFUR FERTILIZER AND SOME FOLIAR FERTILIZERS ON GROWTH AND YIELD OF BROCCOLI IN SALINE SOIL

    Directory of Open Access Journals (Sweden)

    Ali Husain JASIM

    2015-12-01

    Full Text Available Factorial experiment was conducted in the open fields of Agricultural College, Al-Qasim Green University during the agricultural seasons of 2013/2014 and 2014/2015 to study the effect of adding two levels of agricultural sulfur (control and add 100 kg.ha-1 and four levels of nutrient spray (without spray, high-potash fertilizer, high-phosphorus fertilizer and humic acid on growth and yield of broccoli under drip irrigation and polyethylene soil mulching in saline soil (9.6 dS.m-1. Randomized complete block design with three replicates was used. The results showed that agricultural sulfur led to increase number of leaves, leaf area, leaves chlorophyll content, diameter and weight of flower head compared to control. Spraying foliar fertilizer and its interaction with sulfur fertilizer also led to increase all of parameters above (except leaves chlorophyll content significantly compared to control treatment.

  1. Preparation and performance of a sulfur/graphene composite for rechargeable lithium-sulfur battery

    Science.gov (United States)

    Zhang, Feifei; Dong, Yunhui; Huang, Yun; Huang, Gang; Zhang, Xinbo; Wang, Limin

    2012-01-01

    The lithium-sulfur (Li-S) battery is a promising electrochemical system that has high theoretical capacity. The sulfur/graphene nanosheets (S/GNS) composite is prepared through thermal reduction between the sulfur (S) and graphene oxide (GO). The morphology and composition of the composite are analyzed by means of x-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopic (EDS) characterization. It is found that the element S distributed uniformly between the layers of GNS. Graphene with a two-dimensional structure of carbon atoms is employed as a conductive and absorbing agent for the S cathode materials of rechargeable Li-S battery. The S/GNS composite cathode shows a specific electrochemical capacity, which is about 1598 mAh g-1 S at the initial discharge and remains above 670 mAh g-1 after 80 cycles.

  2. Multiwalled carbon nanotubes-sulfur composites with enhanced electrochemical performance for lithium/sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Xin Zhou; Jin, Bo, E-mail: jinbo@jlu.edu.cn; Xin, Pei Ming; Wang, Huan Huan

    2014-07-01

    Multiwalled carbon nanotubes-sulfur (MWCNTs-S) composites were synthesized by chemical activation of MWCNTs and capillarity between sulfur and MWCNTs. The MWCNTs activated by potassium hydroxide (denoted as K-MWCNTs) were used as conductive additive. The as-prepared K-MWCNTs-S composites can display excellent cycle stability and rate capability with the initial discharge capacity of 741 mAh g⁻¹ and capacity retention of 80% after 50 cycles compared to pure S. The improvement in the electrochemical performance for K-MWCNTs-S composites is attributed to the interstitial structure of the MWCNTs resulted from the strong chemical etching, which can facilitate the insertion and extraction of Li ions and more better percolation of the electrolyte, and also ascribed to enhanced electronic conductivity of K-MWCNTs-S composites. It is indicated that the K-MWCNTs-S composites can be used as the cathode materials for lithium–sulfur batteries.

  3. Core-shell meso/microporous carbon host for sulfur loading toward applications in lithium-sulfur batteries

    Institute of Scientific and Technical Information of China (English)

    Juan Zhang; Huan Ye; Yaxia Yin; Yuguo Guo

    2014-01-01

    Lithium-sulfur (Li-S) batteries belong to one of the promising technologies for high-energy-density rechargeable batteries. However, sulfur cathodes suffer from inherent problems of its poor electronic conductivity and the shuttling of highly dissoluble lithium polysulfides generated during the cycles. Loading sulfur into porous carbons has been proved to be an effective approach to alleviate these issues. Mesoporous and microporous carbons have been widely used for sulfur accommodation, but mesoporous carbons have poor sulfur confinement, whereas microporous carbons are impeded by low sulfur loading rates. Here, a core-shell carbon, combining both the merits of mesoporous carbon with large pore volume and microporous carbon with effective sulfur confinement, was prepared by coating the mesoporous CMK-3 with a microporous carbon (MPC) shell and served as the carbon host (CMK-3@MPC) to accommodate sulfur. After sulfur infusion, the as-obtained S/(CMK-3@MPC) cathode delivered a high initial capacity of up to 1422 mAh·g-1 and sustained 654 mAh·g-1 reversible specific capacity after 36 cycles at 0.1 C. The good performance is ascribed to the unique core-shell structure of the CMK-3@MPC matrix, in which sulfur can be effectively confined within the meso/microporous carbon host, thus achieving simultaneously high electrochemical utilization.

  4. Nitrogen--sulfur--carbon nanocomposites and their application as cathode materials in lithium--sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Sheng; Sun, Xiao-Guang; Guo, Bingkun; Wang, Xiqing; Mayes, Richard T.; Ben, Teng; Qiu, Shilun

    2016-09-27

    The invention is directed in a first aspect to electron-conducting porous compositions comprising an organic polymer matrix doped with nitrogen atoms and having elemental sulfur dispersed therein, particularly such compositions having an ordered framework structure. The invention is also directed to composites of such S/N-doped electron-conducting porous aromatic framework (PAF) compositions, or composites of an S/N-doped mesoporous carbon composition, which includes the S/N-doped composition in admixture with a binder, and optionally, conductive carbon. The invention is further directed to cathodes for a lithium-sulfur battery in which such composites are incorporated.

  5. Phototrophic bacteria and their role in the biogeochemical sulfur cycle

    Science.gov (United States)

    Trueper, H. G.

    1985-01-01

    An essential step that cannot be bypassed in the biogeochemical cycle of sulfur today is dissimilatory sulfate reduction by anaerobic bacteria. The enormous amounts of sulfides produced by these are oxidized again either anaerobically by phototrophic bacteria or aerobically by thiobacilli and large chemotrophic bacteria (Beggiatoa, Thiovulum, etc.). Phototrophic bacteria use sulfide, sulfur, thiosulfate, and sulfite as electron donors for photosynthesis. The most obvious intermediate in their oxidative sulfur metabolism is a long chain polysulfide that appears as so called sulfur globules either inside (Chromatiaceae) or outside (Ectothiorhodospiraceae, Chlorobiaceae, and some of the Rhodospirillaceae) the cells. The assimilation of sulfur compounds in phototrophic bacteria is in principle identical with that of nonphototrophic bacteria. However, the Chlorobiaceae and some of the Chromatiaceae and Rhodospirillaceae, unable to reduce sulfate, rely upon reduced sulfur for biosynthetic purposes.

  6. Capital cost: low and high sulfur coal plants; 800 MWe

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-01-01

    This Commercial Electric Power Cost Study for 800-MWe (Nominal) low- and high-sulfur coal plants consists of three volumes. (This is the fourth subject in a series of eight performed in the Commercial Electric Power Cost Studies by the US NRC). The low-sulfur coal plant is described in Volumes I and II, while Volume III (this volume) describes the high sulfur coal plant. The design basis, drawings, and summary cost estimate for a 794-MWe high-sulfur coal plant are presented in this volume. This information was developed by redesigning the low-sulfur sub-bituminous coal plant for burning high-sulfur bituminous coal. The reference design includes a lime flue-gas-desulfurization system. These coal plants utilize a mechanical draft (wet) cooling tower system for condenser heat removal. Costs of alternate cooling systems are provided in Report No. 7 in this series of studies of costs of commercial electrical power plants.

  7. Sulfurized activated carbon for high energy density supercapacitors

    Science.gov (United States)

    Huang, Yunxia; Candelaria, Stephanie L.; Li, Yanwei; Li, Zhimin; Tian, Jianjun; Zhang, Lili; Cao, Guozhong

    2014-04-01

    Sulfurized activated carbon (SAC), made by coating the pore surface with thiophenic sulfur functional groups from the pyrolysis of sulfur flakes, were characterized and tested for supercapacitor applications. From X-ray photoelectron spectroscopy (XPS), the sulfur content in the SAC was found to be 2.7 at%. Electrochemical properties from potentiostatic and galvanostatic measurements, and electrochemical impedance spectroscopy (EIS) were used to evaluate the effect of sulfur on porous carbon electrodes. The SAC electrode exhibits better conductivity, and an obvious increase in specific capacitance that is almost 40% higher than plain activated carbons (ACs) electrode at a high current density of 1.4 A g-1. The proposed mechanism for improved conductivity and capacitive performance due to the sulfur functional groups on ACs will be discussed.

  8. Sulfuric acid leaching kinetics of South African chromite

    Institute of Scientific and Technical Information of China (English)

    Qing Zhao; Cheng-jun Liu; Pei-yang Shi; Bo Zhang; Mao-fa Jiang; Qing-song Zhang; Ron Zevenhoven; Henrik Saxn

    2015-01-01

    The sulfuric acid leaching kinetics of South African chromite was investigated. The negative influence of a solid product layer constituted of a silicon-rich phase and chromium-rich sulfate was eliminated by crushing the chromite and by selecting proper leaching con-ditions. The dimensionless change in specific surface area and the conversion rate of the chromite were observed to exhibit a proportional re-lationship. A modified shrinking particle model was developed to account for the change in reactive surface area, and the model was fitted to experimental data. The resulting model was observed to describe experimental findings very well. Kinetics analysis revealed that the leach-ing process is controlled by a chemical reaction under the employed experimental conditions and the activation energy of the reaction is 48 kJ·mol–1.

  9. Sulfur geochemistry of hydrothermal waters in Yellowstone National Park, Wyoming, USA. II. Formation and decomposition of thiosulfate and polythionate in Cinder Pool

    Science.gov (United States)

    Xu, Y.; Schoonen, M.A.A.; Nordstrom, D.K.; Cunningham, K.M.; Ball, J.W.

    2000-01-01

    , yielding thiosulfate and elemental sulfur; and (2) by disproportionation to sulfate and thiosulfate. This study demonstrates that the presence of a subaqueous molten sulfur pool and sulfur spherules in Cinder Pool is of importance in controlling the pathways of aqueous sulfur redox reactions. Some of the insights gained at Cinder Pool may be relevant to acid crater lakes where sulfur spherules are observed and variations in polythionate concentrations are used to monitor and predict volcanic activity.

  10. Sulfur dioxide contributions to the atmosphere by volcanoes.

    Science.gov (United States)

    Stoiber, R E; Jepsen, A

    1973-11-01

    The first extensive measurements by remote-sensing correlation spectrometry of the sulfur dioxide emitted by volcanic plumes indicate that on the order of 10(3) metric tons of sulfur dioxide gas enter the atmosphere daily from Central American volcanoes. Extrapolation gives a minimum estimate of the annual amount of sulfur dioxide emitted from the world's volcanoes of about 10(7) metric tons.

  11. Sulfur metabolism in the extreme acidophile Acidithiobacillus caldus

    Directory of Open Access Journals (Sweden)

    Stefanie eMangold

    2011-02-01

    Full Text Available Given the challenges to life at low pH, an analysis of inorganic sulfur compound oxidation was initiated in the chemolithoautotrophic extremophile Acidithiobacillus caldus. A. caldus is able to metabolize elemental sulfur and a broad range of inorganic sulfur compounds. 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 inorganic sulfur compound 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 inorganic sulfur compound 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.

  12. Sub-aqueous sulfur volcanos at Waiotapu, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, S.; Rickard, D. [University of Wales, Cardiff (United Kingdom). Dept. of Earth Sciences; Browne, P.; Simmons, S. [University of Auckland (New Zealand). Geothermal Institute and Geology Dept.; Jull, T. [University of Arizona, Tucson (United States). AMS Facility

    1999-12-01

    Exhumed, sub-aqueous sulfur mounds occur in the Waiotapu geothermal area, New Zealand. The extinct mounds are < 2 m high and composed of small (< 0.5 cm) hollow spheres, and occasional teardrop-shaped globules. They are located within a drained valley that until recently was connected to Lake Whangioterangi. They were formed a maximum of 820 {+-} 80 years BP as a result of the rapid sub-aqueous deposition of sulfur globules, formed when fumarolic gases discharged through molten sulfur pools. Similar globules are now being formed by the discharge of fumarolic gases through a sub-aqueous molten sulfur pool in Lake Whangioterangi. (author)

  13. Mercury adsorption properties of sulfur-impregnated adsorbents

    Science.gov (United States)

    Hsi, N.-C.; Rood, M.J.; Rostam-Abadi, M.; Chen, S.; Chang, R.

    2002-01-01

    Carbonaceous and noncarbonaceous adsorbents were impregnated with elemental sulfur to evaluate the chemical and physical properties of the adsorbents and their equilibrium mercury adsorption capacities. Simulated coal combustion flue gas conditions were used to determine the equilibrium adsorption capacities for Hg0 and HgCl2 gases to better understand how to remove mercury from gas streams generated by coal-fired utility power plants. Sulfur was deposited onto the adsorbents by monolayer surface deposition or volume pore filling. Sulfur impregnation increased the total sulfur content and decreased the total and micropore surface areas and pore volumes for all of the adsorbents tested. Adsorbents with sufficient amounts of active adsorption sites and sufficient microporous structure had mercury adsorption capacities up to 4,509 ??g Hg/g adsorbent. Elemental sulfur, organic sulfur, and sulfate were formed on the adsorbents during sulfur impregnation. Correlations were established with R2>0.92 between the equilibrium Hg0/HgCl2 adsorption capacities and the mass concentrations of elemental and organic sulfur. This result indicates that elemental and organic sulfur are important active adsorption sites for Hg0 and HgCl2.

  14. Fractal desulfurization kinetics of high-sulfur coal

    Institute of Scientific and Technical Information of China (English)

    Xu Longjun; Peng Tiefeng; Zhang Dingyue; Zhang Fukai

    2012-01-01

    The pore structure characteristics of high-sulfur coal from Wansheng in Chongqing have been studied by a nitrogen adsorption method (BET).The effects of grinding and pre-treating with nitric acid on the inorganic sulfur content of coal have been investigated.Organic sulfur in coal pretreated with nitric acid was desulfurized by using propylene-glycol-KOH (PG-KOH).Fractal kinetic properties of these two desulfurization procedures were investigated by using fractal geometric theory.The results show that both the specific surface area and pore volume increased with the decrease in particle diameter.The microspore surface of coal had fractal characteristics; the fractal dimension was 2.48.The sulfur content decreased with the decrease in particle diameter by grinding.After pretreatment with nitric acid,the desulfurization ratio (DFR) of inorganic sulfur increased to over 99% and the DFR of total sulfur to over 70%.The desulfurization procedure of inorganic sulfur had fractal kinetic characteristics; its reactive fractal dimension was 2.94.The organic sulfur desulfurization procedure by PG-KOH was also tallied with fractal kinetic properties; the reactive fractal dimension was 2.57.The effect of temperature on the desulfurization ratio of organic sulfur can be described with an Arrhenius empirical equation.The rate constant,pre-exponential factor and the activation energy of the reaction increased with the decrease in particle diameter.

  15. Removal of sulfur compounds from petroleum refinery wastewater through adsorption on modified activated carbon.

    Science.gov (United States)

    Ben Hariz, Ichrak; Al Ayni, Foued; Monser, Lotfi

    2014-01-01

    The adsorption of sulfur compounds from petroleum refinery wastewater on a chemically modified activated carbon (MAC) was investigated. The modification technique (nitric acid, hydrogen peroxide and thermal modification) enhanced the removal capacity of carbon and therefore decreases cost-effective removal of sulfide from refinery wastewater. Adsorption equilibrium and kinetics data were determined for sulfur removal from real refinery wastewater. The data were evaluated according to several adsorption isotherm and kinetics models. The Freundlich isotherm fitted well with the equilibrium data of sulfur on different adsorbents, whereas the kinetics data were best fitted by the pseudo-second-order model. Insights of sulfide removal mechanisms indicated that the sorption was controlled through the intraparticle diffusion mechanism with a significant contribution of film diffusion. The MAC adsorbent was found to have an effective removal capacity of approximately 2.5 times that of non-modified carbon. Using different MAC, sulfides were eliminated with a removal capacity of 52 mg g(-1). Therefore, MAC can be utilized as an effective and less expensive adsorbent for the reduction of sulfur in refinery wastewater.

  16. Sulfur deficiency–induced repressor proteins optimize glucosinolate biosynthesis in plants

    Science.gov (United States)

    Aarabi, Fayezeh; Kusajima, Miyuki; Tohge, Takayuki; Konishi, Tomokazu; Gigolashvili, Tamara; Takamune, Makiko; Sasazaki, Yoko; Watanabe, Mutsumi; Nakashita, Hideo; Fernie, Alisdair R.; Saito, Kazuki; Takahashi, Hideki; Hubberten, Hans-Michael; Hoefgen, Rainer; Maruyama-Nakashita, Akiko

    2016-01-01

    Glucosinolates (GSLs) in the plant order of the Brassicales are sulfur-rich secondary metabolites that harbor antipathogenic and antiherbivory plant-protective functions and have medicinal properties, such as carcinopreventive and antibiotic activities. Plants repress GSL biosynthesis upon sulfur deficiency (−S); hence, field performance and medicinal quality are impaired by inadequate sulfate supply. The molecular mechanism that links –S to GSL biosynthesis has remained understudied. We report here the identification of the –S marker genes sulfur deficiency induced 1 (SDI1) and SDI2 acting as major repressors controlling GSL biosynthesis in Arabidopsis under –S condition. SDI1 and SDI2 expression negatively correlated with GSL biosynthesis in both transcript and metabolite levels. Principal components analysis of transcriptome data indicated that SDI1 regulates aliphatic GSL biosynthesis as part of –S response. SDI1 was localized to the nucleus and interacted with MYB28, a major transcription factor that promotes aliphatic GSL biosynthesis, in both yeast and plant cells. SDI1 inhibited the transcription of aliphatic GSL biosynthetic genes by maintaining the DNA binding composition in the form of an SDI1-MYB28 complex, leading to down-regulation of GSL biosynthesis and prioritization of sulfate usage for primary metabolites under sulfur-deprived conditions.

  17. Catalyst Design for the Electrocatalytic Hydrogenation of Model Compounds in the Presence of Sulfur

    Science.gov (United States)

    Murphy, Sean

    In this research, the electrocatalytic hydrogenation of 2-cyclohexen-1-one by Ni-Wand W-S catalysts is investigated. The objective was to demonstrate catalytic activity of sulfide-based electrodes for the hydrogenation reaction in the presence of sulfur containing molecules representative of those found in bitumen distillate fractions. Ni and Pd catalysts were investigated as control standards for the hydrogenation reaction. Both catalysts were found to be ineffective in the presence of sulfur. Ni-W composite films supported on aluminum have been shown to be catalytically active for the electrocatalytic hydrogenation of 2-cyclohexen-1-one, but are poisoned in the presence of sulfur. WS2 catalysts particles supported on vitreous carbon have been shown to be active for the electrocatalytic hydrogenation in the presence of sulfur. The ionic liquid 1-butyl-3-methyl-imidazlium tetrafluoroborate was investigated as a solvent for e1ectrocatalytic hydrogenation reactions. It was found to be incompatible with a vitreous carbon anode and reacted immediately producing an insulating film.

  18. Direct observation of lithium polysulfides in lithium-sulfur batteries using operando X-ray diffraction

    Science.gov (United States)

    Conder, Joanna; Bouchet, Renaud; Trabesinger, Sigita; Marino, Cyril; Gubler, Lorenz; Villevieille, Claire

    2017-06-01

    In the on going quest towards lithium-battery chemistries beyond the lithium-ion technology, the lithium-sulfur system is emerging as one of the most promising candidates. The major outstanding challenge on the route to commercialization is controlling the so-called polysulfide shuttle, which is responsible for the poor cycling efficiency of the current generation of lithium-sulfur batteries. However, the mechanistic understanding of the reactions underlying the polysulfide shuttle is still incomplete. Here we report the direct observation of lithium polysulfides in a lithium-sulfur cell during operation by means of operando X-ray diffraction. We identify signatures of polysulfides adsorbed on the surface of a glass-fibre separator and monitor their evolution during cycling. Furthermore, we demonstrate that the adsorption of the polysulfides onto SiO2 can be harnessed for buffering the polysulfide redox shuttle. The use of fumed silica as an electrolyte additive therefore significantly improves the specific charge and Coulombic efficiency of lithium-sulfur batteries.

  19. Effect of Sulfurization Temperature on Thioetheriifcation Performance of Mo-Ni/Al2O3 Catalyst

    Institute of Scientific and Technical Information of China (English)

    Shen Zhibing; Ke Ming; Ren Tao; Zhang Juntao; Liang Shengrong

    2015-01-01

    The Mo modiifed Ni/Al2O3 catalysts were prepared and sulifded at different temperatures, and their catalytic acti-vity for thioetheriifcation of mercaptans and oleifns (or dienes), hydrogenation of dienes and oleifns in the thioetheriifcation process using lfuidized catalytic cracking (FCC) naphtha as the feedstock was investigated. In order to disclose the correla-tion between the physicochemical characteristics of catalysts and their catalytic activity, the surface structures and properties of the catalysts sulifded at different temperatures were characterized by the high resolution transmission electronic micro-scopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and H2-temperature programmed reduction (H2-TPR) technique. The results showed that an increase of sulfurization temperature not only could promote the sulfurization degree of active metals on the catalysts, but also could adjust the micro-morphology of active species. These changes could improve the catalytic performance of thioetheriifcation, and hydrogenation of dienes and oleifns. However, an excess sulfurization tem-perature was more easily to upgrade the ability of the catalyst for hydrogenation of oleifns, which could lead to a decrease of the octane number of the product. It was also showed that a moderate sulfurization temperature not only could improve the catalytic performance of thioetheriifcation and hydrogenation of dienes but also could control hydrogenation of oleifns.

  20. The triple point of sulfur hexafluoride

    Science.gov (United States)

    Rourke, P. M. C.

    2016-04-01

    A cryogenic fixed point cell has been filled with high purity (99.999%) sulfur hexafluoride (SF6) and measured in an adiabatic closed-cycle cryostat system. Temperature measurements of the SF6 melting curve were performed using a capsule-type standard platinum resistance thermometer (CSPRT) calibrated over the International Temperature Scale of 1990 (ITS-90) subrange from the triple point of equilibrium hydrogen to the triple point of water. The measured temperatures were corrected by 0.37 mK for the effects of thermometer self-heating, and the liquidus-point temperature estimated by extrapolation to melted fraction F  =  1 of a simple linear regression versus melted fraction F in the range F  =  0.53 to 0.84. Based on this measurement, the temperature of the triple point of sulfur hexafluoride is shown to be 223.555 23(49) K (k  =  1) on the ITS-90. This value is in excellent agreement with the best prior measurements reported in the literature, but with considerably smaller uncertainty. An analysis of the detailed uncertainty budget of this measurement suggests that if the triple point of sulfur hexafluoride were to be included as a defining fixed point of the next revision of the International Temperature Scale, it could do so with a total realization uncertainty of approximately 0.43 mK, slightly larger than the realization uncertainties of the defining fixed points of the ITS-90. Since the combined standard uncertainty of this SF6 triple point temperature determination is dominated by chemical impurity effects, further research exploring gas purification techniques and the influence of specific impurity species on the SF6 triple point temperature may bring the realization uncertainty of SF6 as a fixed point material into the range of the defining fixed points of the ITS-90.

  1. Amine reactivity with charged sulfuric acid clusters

    Science.gov (United States)

    Bzdek, B. R.; Ridge, D. P.; Johnston, M. V.

    2011-08-01

    The distribution of charged species produced by electrospray of an ammonium sulfate solution in both positive and negative polarities is examined using Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). Positively-charged ammonium bisulfate cluster composition differs significantly from negatively-charged cluster composition. For positively-charged clusters all sulfuric acid is neutralized to bisulfate, whereas for negatively-charged clusters the degree of sulfuric acid neutralization is cluster size-dependent. With increasing cluster size (and, therefore, a decreasing role of charge), both positively- and negatively-charged cluster compositions converge toward ammonium bisulfate. The reactivity of negatively-charged sulfuric acid-ammonia clusters with dimethylamine and ammonia is also investigated by FTICR-MS. Two series of negatively-charged clusters are investigated: [(HSO4)(H2SO4)x]- and [(NH4)x(HSO4)x+1(H2SO4)3]-. Dimethylamine substitution for ammonia in [(NH4) x(HSO4) x+1(H2SO4)3]- clusters is nearly collision-limited, and subsequent addition of dimethylamine to neutralize H2SO4 to bisulfate is within one order of magnitude of the substitution rate. Dimethylamine addition to [(HSO4) (H2SO4) x]- clusters is either not observed or very slow. The results of this study indicate that amine chemistry will be evident and important only in large ambient negative ions (>m/z 400), whereas amine chemistry may be evident in small ambient positive ions. Addition of ammonia to unneutralized clusters occurs at a rate that is ~2-3 orders of magnitude slower than incorporation of dimethylamine either by substitution or addition. Therefore, in locations where amine levels are within a few orders of magnitude of ammonia levels, amine chemistry may compete favorably with ammonia chemistry.

  2. Genetic engineering of sulfur-degrading Sulfolobus

    Energy Technology Data Exchange (ETDEWEB)

    Ho, N.W.Y. (Purdue Univ., Lafayette, IN (United States). Lab. of Renewable Resources Engineering)

    1991-01-01

    An effective microbial process would be economical for the removal or organic sulfur and the finely dispersed inorganic sulfur in coal, particularly the former. However, some microoganisms may have the enzymes to degrade organic sulfur but themselves are not suitable to be cultured under the conditions best for coal desulfurization. On the other hand, some microorganisms can grow very well under the conditions most suitable for coal desulfurization but do not contain the enzymes most suitable for coal desulfurization. We believe that we can adopt a new approach to solve this problem. In this approach, a microorganism that can grow vigorously under the conditions most suitable for coal desulfurization will be chosen as the host for actively carrying out the desulfurization process. An effective gene cloning system is expected to be established for the chosen species so that heterologous and homologous genes encoding most of the effective enzymes for coal desulfurization can be cloned on the highly copy-number plasmid or plasmid-like molecules. Species of Sulfolobus are microorganisms that can be actively cultured under the condition most favorable for coal desulfurization. In particular, one of the Sulfolobus species, S. shibatae B12, contains a double-stranded DNA virus which might be easily converted into a gene cloning system. The objective of this project is to develop an effective gene cloning system for some of the Sulfolobus species. During the first two quarters of this year, we have shown that gene cloning systems might be able to be established for at least two of the Sulfolobus species; S. acidocaldarius and S. shibatae B12. In this quarter, we report on: (1) The construction of potential cloning vectors for the transformation of both S. acidocaldarius and S. shibatae B12; (2) the isolation of promoters from S. Shibatae and S. acidocaldarius, which can also function as promoters in E. coli.

  3. Genetic engineering of sulfur-degrading Sulfolobus

    Energy Technology Data Exchange (ETDEWEB)

    Ho, N.W.Y. (Purdue Univ., Lafayette, IN (USA). 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.

  4. Graphene/sulfur hybrid nanosheets from a space-confined "sauna" reaction for high-performance lithium-sulfur batteries.

    Science.gov (United States)

    Fei, Linfeng; Li, Xiaogang; Bi, Wentuan; Zhuo, Zhiwen; Wei, Wenfei; Sun, Li; Lu, Wei; Wu, Xiaojun; Xie, Keyu; Wu, Changzheng; Chan, Helen L W; Wang, Yu

    2015-10-21

    A space-confined "sauna" reaction system is introduced for the simultaneous reduction and functionalization of graphene oxide to unique graphene-sulfur hybrid nanosheets, in which thin layers of amorphous sulfur are tightly anchored on the graphene sheet via strong chemical bonding. Upon being used as the cathode material in lithium-sulfur batteries, the as-synthesized composite shows an excellent electrochemical performance.

  5. A dual coaxial nanocable sulfur composite for high-rate lithium-sulfur batteries.

    Science.gov (United States)

    Li, Zhen; Yuan, Lixia; Yi, Ziqi; Liu, Yang; Xin, Ying; Zhang, Zhaoliang; Huang, Yunhui

    2014-01-01

    Lithium-sulfur batteries have great potential for some high energy applications such as in electric vehicles and smart grids due to their high capacity, natural abundance, low cost and environmental friendliness. But they suffer from rapid capacity decay and poor rate capability. The problems are mainly related to the dissolution of the intermediate polysulfides in the electrolyte, and to the poor conductivity of sulfur and the discharge products. In this work, we propose a novel dual coaxial nanocable sulfur composite fabricated with multi-walled nanotubes (MWCNT), nitrogen-doped porous carbon (NPC) and polyethylene glycol (PEG), i.e. MWCNTs@S/NPC@PEG nanocable, as a cathode material for Li-S batteries. In such a coaxial structure, the middle N-doped carbon with hierarchical porous structure provides a nanosized capsule to contain and hold the sulfur particles; the inner MWCNTs and the outer PEG layer can further ensure the fast electronic transport and prevent the dissolution of the polysulfides into the electrolyte, respectively. The as-designed MWCNT@S/NPC@PEG composite shows good cycling stability and excellent rate capability. The capacity is retained at 527 mA h g(-1) at 1 C after 100 cycles, and 791 mA h g(-1) at 0.5 C and 551 mA h g(-1) at 2 C after 50 cycles. Especially, the high-rate capability is outstanding with 400 mA h g(-1) at 5 C.

  6. Electron capture sulfur detector: reduced sulfur species detection at the femtomole level

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J.E.; Lovelock, J.E.

    1988-04-15

    The authors have developed a new technique to detect reduced sulfur compounds by fluorination with F/sub 2/ (at 200 ppm) on a heated Ag catalyst after GC separation. The excess F/sub 2/ is removed by conversion to HF by reaction with H/sub 2/ on a heated Pd catalysts. The fluorination product, presumably SF/sub 6/, is then detected in an electron capture detector (ECD). The Pd catalyst also destroys the response from halocarbons making the system sulfur specific. This ECD sulfur detector has a calculated minimum detectable level (MDL) for H/sub 2/S, OCS, CH/sub 3/SH, DMS, and CS/sub 2/ of less than 2 fmol/s for each compound, 2 orders of magnitude lower than the best FPD systems. The ratio of the detected molar response of each of these sulfur compounds to the molar response of SF/sub 6/ ranges from 2% to 20% and increases with increasing AgF/sub 2/ temperature.

  7. Benzoylphenylurea sulfur analogues with potent antitumor activity.

    Science.gov (United States)

    Hallur, Gurulingappa; Jimeno, Antonio; Dalrymple, Susan; Zhu, Tao; Jung, M Katherine; Hidalgo, Manuel; Isaacs, John T; Sukumar, Saraswati; Hamel, Ernest; Khan, Saeed R

    2006-04-06

    A novel series of BPU analogues were synthesized and evaluated for antitumor activity. In particular, BPU sulfur analogues 6n and 7d were shown to possess up to 10-fold increased potency, when compared to 1 (NSC-639829), against cancer cell lines. 6n was more effective than 1 in causing apoptosis of MCF-7 cells. When compared to other drugs with a similar mechanism of action, 6n retained significant ability to inhibit tubulin assembly, with an IC(50) of 2.1 microM.

  8. Bioinspired catalysis metal-sulfur complexes

    CERN Document Server

    Weigand, Wolfgang

    2014-01-01

    The growing interest in green chemistry calls for new, efficient and cheap catalysts. Living organisms contain a wide range of remarkably powerful enzymes, which can be imitated by chemists in the search for new catalysts. In bioinspired catalysis, chemists use the basic principles of biological enzymes when creating new catalyst analogues. In this book, an international group of experts cover the topic from theoretical aspects to applications by including a wide variety of examples of different systems. This valuable overview of bioinspired metal-sulfur catalysis is a must-have for all sci

  9. Simultaneous activation/sulfurization method for production of sulfurized activated carbons: characterization and Hg(II) adsorption capacity.

    Science.gov (United States)

    Shamsijazeyi, Hadi; Kaghazchi, Tahereh

    2014-01-01

    As an inexpensive method for modification of activated carbons (ACs), sulfurization has attracted significant attention. However, the resulting sulfurized activated carbons (SACs) often are less porous than the original ACs. In this work, we propose a new method for concurrent sulfurization/activation that can lead to preparation of SACs with more porosity than the corresponding non-sulfurized ACs. By using scanning electron microscopy, nitrogen adsorption/desorption, and iodine number experiments, the porous structure of the SACs has been compared with that of non-sulfurized ACs. The specific surface areas of SACs are higher than the corresponding ACs, regardless of the type of activation agents used. For instance, the specific surface area of SAC and AC activated with phosphoric acid is 1,637 and 1,338 m(2)/g, respectively. Additionally, sulfur contents and surface charges (pHpzc) of the SACs and non-sulfurized ACs are compared. In fact, the SACs have higher sulfur contents and more acidic surfaces. Furthermore, the Hg(II) adsorption capacity of SACs has been compared with the corresponding non-sulfurized ACs. The Hg(II) adsorption isotherms on a selected SAC is measured at different pH values and temperatures. Hg(II) adsorptions as high as 293 mg/g are observed by using SACs prepared by the method proposed in this study.

  10. Parameters Influencing Sulfur Speciation in Environmental Samples Using Sulfur K-Edge X-Ray Absorption Near-Edge Structure

    Directory of Open Access Journals (Sweden)

    Siwatt Pongpiachan

    2012-01-01

    Full Text Available This paper aims to enhance the credibility of applying the sulfur K-edge XANES spectroscopy as an innovative “fingerprint” for characterizing environmental samples. The sensitivities of sulfur K-edge XANES spectra of ten sulfur compound standards detected by two different detectors, namely, Lytle detector (LyD and Germanium detector (GeD, were studied and compared. Further investigation on “self-absorption” effect revealed that the maximum sensitivities of sulfur K-edge XANES spectra were achieved when diluting sulfur compound standards with boron nitride (BN at the mixing ratio of 0.1%. The “particle-size” effect on sulfur K-edge XANES spectrum sensitivities was examined by comparing signal-to-noise ratios of total suspended particles (TSP and particulate matter of less than 10 millionths of a meter (PM10 collected at three major cities of Thailand. The analytical results have demonstrated that the signal-to-noise ratios of sulfur K-edge XANES spectra were positively correlated with sulfate content in aerosols and negatively connected with particle sizes. The combination of hierarchical cluster analysis (HCA and principal component analysis (PCA has proved that sulfur K-edge XANES spectrum can be used to characterize German terrestrial soils and Andaman coastal sediments. In addition, this study highlighted the capability of sulfur K-edge XANES spectra as an innovative “fingerprint” to distinguish tsunami backwash deposits (TBD from typical marine sediments (TMS.

  11. Sulfur the archetypal catalyst poison? The sulfur-induced promotion of the bonding of unsaturated hydrocarbons on Cu(111).

    Science.gov (United States)

    Rousseau, G B D; Bovet, N; Kadodwala, M

    2006-11-02

    We have shown using a combination of temperature-programmed desorption and UV photoelectron spectroscopy that the presence of preadsorbed atomic sulfur promotes the bonding of cyclic unsaturated hydrocarbons (benzene and cyclohexene) to Cu(111). This promoting behavior of sulfur can be rationalized in terms of the ability of adsorbed sulfur to influence the balance between charge donation from the adsorbate to metal, and back-donation from the metal to adsorbate. The effects of sulfur on Cu(111) are dramatically different from those observed in previous studies on Pt(111), which found that it caused a downward shift in the desorption temperature of adsorbed benzene, through purely steric effects.

  12. Enhanced electrochemical performance of a crosslinked polyaniline-coated graphene oxide-sulfur composite for rechargeable lithium-sulfur batteries

    Science.gov (United States)

    Moon, San; Jung, Young Hwa; Kim, Do Kyung

    2015-10-01

    Due to the extraordinarily high theoretical capacity of sulfur (1675 mAh g-1), the lithium-sulfur (Li-S) battery has been considered a promising candidate for future high-energy battery applications. Li-S batteries, however, have suffered from limited cycle lives, mainly due to the formation of soluble polysulfides, which prevent the practical application of this attractive technology. The encapsulation of sulfur with various conductive materials has addressed this issue to some extent. Nevertheless, most approaches still present partial encapsulation of sulfur and moreover require a large quantity of conductive material (typically, >30 wt%), making the use of sulfur less desirable from the viewpoint of capacity. Here, we address these chronic issues of Li-S cells by developing a graphene oxide-sulfur composite with a thin crosslinked polyaniline (PANI) layer. Graphene oxide nanosheets with large surface area, high conductivity and a uniform conductive PANI layer, which are synthesized by a layer-by-layer method, have a synergetic interaction with a large portion of the sulfur in the active material. Furthermore, a simple crosslinking process efficiently prevents polysulfide dissolution, resulting in unprecedented electrochemical performance, even with a high sulfur content (∼75%): a high capacity retention of ∼80% is observed, in addition to 97.53% of the average Coulombic efficiency being retained after 500 cycles. The performance we demonstrate represents an advance in the field of lithium-sulfur batteries for applications such as power tools.

  13. Reduction of Sulfur Dioxide on Carbons Catalyzed by Salts

    Directory of Open Access Journals (Sweden)

    Wido Schreiner

    2005-01-01

    Full Text Available Abstract. The reduction of SO2 on different carbons in the presence of the nitrates and sulfides of sodium, potassium and calcium and potassium polysulfides was studied. The presence of salts increased the initial rate 2-5 fold for all of them and did not change the product distribution. The catalysis was not determined by the cation and there was no difference in the catalytic reactivity between nitrates and sulfides. The sulfur content of the activated carbon increased during the reaction on account of the stable reactive intermediates in the reduction of SO2. In the presence of NaNO3 or Na2S, the amount of sulfur incorporated was in the molar ratio Na:S = 3 ± 0.3, and the XPS spectra of the residual carbon showed an increase of ca. 9% of the non-oxidized form of sulfur in the intermediates. In the absence of salt, it is proposed that after the adsorption of SO2 on the carbon, a 1,3,2-dioxathiolane or 1,2-oxathietene 2-oxide are formed and that decompose to produce CO2 and atomic sulfur. The non-oxidized sulfur intermediate would be an episulfide 3, formed from the reaction of the atomic sulfur with the nearest double bond and followed by consecutive reactions of insertion of atomic sulfur to form a trisulfide. Extrusion of S2 from the trisulfide would regenerate the episulfide, establishing a sulfidedisulfide-trisulfide equilibrium that worked as a capture-release cycle of sulfur. In the presence of salt, the results are consistent with the assumption that the episulfide 3 reacts with the corresponding sulfide anion to form a disulfide anion, which upon reaction with atomic sulfur forms a trisulfide anion that decomposes releasing diatomic sulfur S2, transporting the sulfur and generating a thiolate that is part of the catalytic cycle.

  14. 40 CFR Appendix T to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur...

    Science.gov (United States)

    2010-07-01

    ... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) T Appendix T to Part 50 Protection of... AIR QUALITY STANDARDS Pt. 50, App. T Appendix T to Part 50—Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) 1. General (a) This appendix...

  15. In-line estimation of sulfur and nitrogen contents during hydrotreating of middle distillates

    Directory of Open Access Journals (Sweden)

    M. E. Pacheco

    2009-12-01

    Full Text Available The main objective of this work is analyzing whether it is possible to develop an empirical correlation for in-line estimation of the sulfur and nitrogen contents of the middle distillates Hydrotreating (HDT products for control purposes. Correlations are based only on readily available in-line information of specific gravity variation between feedstock and products, without considering any piece of information about the kinetic behavior of the catalyst. Experimental data were obtained in pilot plants under operating conditions that are representative of refinery operations. Results indicate that the removal of nitrogen and sulfur compounds during middle distillates HDT can be monitored in-line in real time, based on the available measurements of specific gravity. This allows for development and implementation of advanced in-line procedures for monitoring and control of the HDT process in real time.

  16. Magnetic effects in sulfur-decorated graphene

    Science.gov (United States)

    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.

  17. The partitioning of calcium and sulfur between bottom ash and flyash in a commercial CFB boiler

    Energy Technology Data Exchange (ETDEWEB)

    Rozelle, P.L.; Pisupati, S.V.; Morrison, J.L.; Scaroni, A.W.

    1999-07-01

    As part of a program to examine the effect of sorbent properties on sulfation performance in the circulating fluidized bed (CFB) combustion process, a series of sorbents varying in chemical composition was tested under similar operating conditions in a 30 MW(e) CFB boiler. These sorbents ranged from 27.8 to 55.2 wt% CaO, and from 0.54 to 18.8 wt% MgO. The fuel used was a high ash content (68 wt%) coal refuse. Parameters of boiler operation were established from distributed control system data, used to screen test results, and data were eliminated from consideration where changes in boiler load or bed inventory levels were seen prior to sampling of bottom ash and flyash streams. This, and the development of a set of simultaneous equations for measuring individual ash stream flow rates, allowed the computation of calcium and sulfur material balances around the boiler for each sorbent test. The partitioning of calcium and sulfur to the bottom ash and flyash streams was examined. It was found that the majority of both calcium and sulfur fed to the boiler was removed with the flyash, regardless of the sorbent. It was further found that across the range of sorbent properties, the flow of sulfur as a solid with the flyash was relatively uniform (71 to 86 wt% of that fed to the boiler). Calcium to sulfur ratios in the bottom ash were uniformly higher than those found for the corresponding flyash streams, indicating that attrition may play a key role in overall sorbent performance. The calcium balance data also indicated that thermally induced fractures (TIFs) may affect attrition.

  18. Attribution of atmospheric sulfur dioxide over the English Channel to dimethyl sulfide and changing ship emissions

    Science.gov (United States)

    Yang, Mingxi; Bell, Thomas G.; Hopkins, Frances E.; Smyth, Timothy J.

    2016-04-01

    Atmospheric sulfur dioxide (SO2) was measured continuously from the Penlee Point Atmospheric Observatory (PPAO) near Plymouth, United Kingdom, between May 2014 and November 2015. This coastal site is exposed to marine air across a wide wind sector. The predominant southwesterly winds carry relatively clean background Atlantic air. In contrast, air from the southeast is heavily influenced by exhaust plumes from ships in the English Channel as well as near Plymouth Sound. A new International Maritime Organization (IMO) regulation came into force in January 2015 to reduce the maximum allowed sulfur content in ships' fuel 10-fold in sulfur emission control areas such as the English Channel. Our observations suggest a 3-fold reduction in ship-emitted SO2 from 2014 to 2015. Apparent fuel sulfur content calculated from coincidental SO2 and carbon dioxide (CO2) peaks from local ship plumes show a high level of compliance to the IMO regulation (> 95 %) in both years (˜ 70 % of ships in 2014 were already emitting at levels below the 2015 cap). Dimethyl sulfide (DMS) is an important source of atmospheric SO2 even in this semi-polluted region. The relative contribution of DMS oxidation to the SO2 burden over the English Channel increased from about one-third in 2014 to about one-half in 2015 due to the reduction in ship sulfur emissions. Our diel analysis suggests that SO2 is removed from the marine atmospheric boundary layer in about half a day, with dry deposition to the ocean accounting for a quarter of the total loss.

  19. Quantification and isotopic analysis of intracellular sulfur metabolites in the dissimilatory sulfate reduction pathway

    Science.gov (United States)

    Sim, Min Sub; Paris, Guillaume; Adkins, Jess F.; Orphan, Victoria J.; Sessions, Alex L.

    2017-06-01

    Microbial sulfate reduction exhibits a normal isotope effect, leaving unreacted sulfate enriched in 34S and producing sulfide that is depleted in 34S. However, the magnitude of sulfur isotope fractionation is quite variable. The resulting changes in sulfur isotope abundance have been used to trace microbial sulfate reduction in modern and ancient ecosystems, but the intracellular mechanism(s) underlying the wide range of fractionations remains unclear. Here we report the concentrations and isotopic ratios of sulfur metabolites in the dissimilatory sulfate reduction pathway of Desulfovibrio alaskensis. Intracellular sulfate and APS levels change depending on the growth phase, peaking at the end of exponential phase, while sulfite accumulates in the cell during stationary phase. During exponential growth, intracellular sulfate and APS are strongly enriched in 34S. The fractionation between internal and external sulfate is up to 49‰, while at the same time that between external sulfate and sulfide is just a few permil. We interpret this pattern to indicate that enzymatic fractionations remain large but the net fractionation between sulfate and sulfide is muted by the closed-system limitation of intracellular sulfate. This 'reservoir effect' diminishes upon cessation of exponential phase growth, allowing the expression of larger net sulfur isotope fractionations. Thus, the relative rates of sulfate exchange across the membrane versus intracellular sulfate reduction should govern the overall (net) fractionation that is expressed. A strong reservoir effect due to vigorous sulfate reduction might be responsible for the well-established inverse correlation between sulfur isotope fractionation and the cell-specific rate of sulfate reduction, while at the same time intraspecies differences in sulfate uptake and/or exchange rates could account for the significant scatter in this relationship. Our approach, together with ongoing investigations of the kinetic isotope

  20. Sulfur recovery from low H{sub 2}S content acid gas using catalytic partial oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Clark, P.D.; Dowling, N.I.; Huang, M.

    2010-01-15

    The poster presentation discussed a new strategy for recovering sulfur from low hydrogen-sulphide-content acid gas using catalytic partial oxidation. In a new technology for dealing with BTX-contaminated lean acid gas, a catalytic reactor replaces the burner-furnace stage to achieve BTX conversion greater than 95 percent and control the hydrogen sulfide/sulfur dioxide ratio. The product gas is then sent to the Claus catalytic converters. The best catalysts for this process are alumina-supported Co-Mo and y-alumina. This process was compared with SELECTOX, another process that deals with poor acid gas with BTX conversion better than 95 percent. Catalytic oxidation can deal with a higher BTX feed content than SELECTOX, but the running temperature is higher. Both processes produce acceptable sulfur quality. To improve this process, the quality of the sulfur produced and the lifetime of the catalyst need to be increased, and an economic way to increase the heat to reach the running temperature needs to be found. The partial oxidation (POX) of CH{sub 4} solves both of these problems. The catalytic POX of acid gas is combined with the POX of fuel gas in the pre-heating zone. This process has the advantage that the burner-furnace stage of the Claus process can be replaced by a stream containing H{sub 2}S/SO{sub 2}=2; the reaction is performed at its adiabatic temperature requiring only a small amount of fuel gas; the presence of H{sub 2} and CO produced by the POX of fuel gas improves the quality of sulfur; the catalyst remains active for about 30 hours; and the process can tolerate high BTX content. 6 tabs., 2 figs.

  1. KINETICS OF DIRECT OXIDATION OF H2S IN COAL GAS TO ELEMENTAL SULFUR

    Energy Technology Data Exchange (ETDEWEB)

    K.C. Kwon

    2004-01-01

    The direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and the hot-gas desulfurization using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process. The objective of this research is to support the near- and long-term process development efforts to commercialize this direct oxidation technology. The objectives of this research are to measure kinetics of direct oxidation of H{sub 2}S to elemental sulfur in the presence of a simulated coal gas mixture containing SO{sub 2}, H{sub 2}, and moisture, using 160-{micro}m C-500-04 alumina catalyst particles and a micro bubble reactor, and to develop kinetic rate equations and model the direct oxidation process to assist in the design of large-scale plants. This heterogeneous catalytic reaction has gaseous reactants such as H{sub 2}S and SO{sub 2}. However, this heterogeneous catalytic reaction has heterogeneous products such as liquid elemental sulfur and steam. To achieve the above-mentioned objectives, experiments on conversion of hydrogen sulfide into liquid elemental sulfur were carried out for the space time range of 1-6 milliseconds at 125-155 C to evaluate effects of reaction temperature, moisture concentration, reaction pressure on conversion of hydrogen sulfide into liquid elemental sulfur. Simulated coal gas mixtures consist of 70 v% hydrogen, 2,500-7,500-ppmv hydrogen sulfide, 1,250-3,750 ppmv sulfur dioxide, and 0-15 vol% moisture, and nitrogen as remainder. Volumetric feed rates of a simulated coal gas mixture to a micro bubble reactor are 100 cm{sup 3}/min at room temperature and atmospheric pressure. The temperature of the reactor is controlled in an oven at 125-155 C. The

  2. KINETICS OF DIRECT OXIDATION OF H2S IN COAL GAS TO ELEMENTAL SULFUR

    Energy Technology Data Exchange (ETDEWEB)

    K.C. Kwon

    2005-01-01

    The direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and the hot-gas desulfurization using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process. The objective of this research is to support the near- and long-term process development efforts to commercialize this direct oxidation technology. The objectives of this research are to measure kinetics of direct oxidation of H{sub 2}S to elemental sulfur in the presence of a simulated coal gas mixture containing SO{sub 2}, H{sub 2}, and moisture, using 160-{micro}m C-500-04 alumina catalyst particles and a micro bubble reactor, and to develop kinetic rate equations and model the direct oxidation process to assist in the design of large-scale plants. This heterogeneous catalytic reaction has gaseous reactants such as H{sub 2}S and SO{sub 2}. However, this heterogeneous catalytic reaction has heterogeneous products such as liquid elemental sulfur and steam. To achieve the above-mentioned objectives, experiments on conversion of hydrogen sulfide into liquid elemental sulfur were carried out for the space time range of 0.059-0.87 seconds at 125-155 C to evaluate effects of reaction temperature, H{sub 2}S concentration, reaction pressure, and catalyst loading on conversion of hydrogen sulfide into liquid elemental sulfur. Simulated coal gas mixtures consist of 62-78 v% hydrogen, 3,000-7,000-ppmv hydrogen sulfide, 1,500-3,500 ppmv sulfur dioxide, and 10 vol % moisture, and nitrogen as remainder. Volumetric feed rates of a simulated coal gas mixture to a micro bubble reactor are 50 cm{sup 3}/min at room temperature and atmospheric pressure. The temperature of the reactor is controlled in an

  3. Diurnal Variation and Spatial Distribution Effects on Sulfur Speciation in Aerosol Samples as Assessed by X-Ray Absorption Near-Edge Structure (XANES

    Directory of Open Access Journals (Sweden)

    Siwatt Pongpiachan

    2012-01-01

    Full Text Available This paper focuses on providing new results relating to the impacts of Diurnal variation, Vertical distribution, and Emission source on sulfur K-edge XANES spectrum of aerosol samples. All aerosol samples used in the diurnal variation experiment were preserved using anoxic preservation stainless cylinders (APSCs and pressure-controlled glove boxes (PCGBs, which were specially designed to prevent oxidation of the sulfur states in PM10. Further investigation of sulfur K-edge XANES spectra revealed that PM10 samples were dominated by S(VI, even when preserved in anoxic conditions. The “Emission source effect” on the sulfur oxidation state of PM10 was examined by comparing sulfur K-edge XANES spectra collected from various emission sources in southern Thailand, while “Vertical distribution effects” on the sulfur oxidation state of PM10 were made with samples collected from three different altitudes from rooftops of the highest buildings in three major cities in Thailand. The analytical results have demonstrated that neither “Emission source” nor “Vertical distribution” appreciably contribute to the characteristic fingerprint of sulfur K-edge XANES spectrum in PM10.

  4. Structural change of the porous sulfur cathode using gelatin as a binder during discharge and charge

    Energy Technology Data Exchange (ETDEWEB)

    Wang You [Department of Material Science and Engineering, Beijing University of Chemical Technology, 15 BeiSanhuan East Road, Beijing 100029 (China); Huang Yaqin [Department of Material Science and Engineering, Beijing University of Chemical Technology, 15 BeiSanhuan East Road, Beijing 100029 (China)], E-mail: huangyaqin9@sina.com; Wang Weikun [Military Power Sources Research and Development Center, Chemical Defense Institute, 35 Huayuan North Road, Beijing 100083 (China); Huang Chongjun [Department of Material Science and Engineering, Beijing University of Chemical Technology, 15 BeiSanhuan East Road, Beijing 100029 (China); Yu Zhongbao; Zhang, Hao [Military Power Sources Research and Development Center, Chemical Defense Institute, 35 Huayuan North Road, Beijing 100083 (China); Sun Jing [Department of Material Science and Engineering, Beijing University of Chemical Technology, 15 BeiSanhuan East Road, Beijing 100029 (China); Wang Anbang; Yuan Keguo [Military Power Sources Research and Development Center, Chemical Defense Institute, 35 Huayuan North Road, Beijing 100083 (China)

    2009-06-30

    The structural change of the porous sulfur cathode using gelatin as a binder was studied by means of scanning electron microscopy (SEM) and X-ray diffractometry (XRD). The original sulfur cathode exhibited a homogenous distribution of sulfur, carbon and pores. During the discharge process, the pores and elemental sulfur disappeared gradually. However, those changes were reversed and elemental sulfur was reformed after the charge process, which improved the electrochemical performance of lithium-sulfur batteries.

  5. Effects of sulfur dioxide on resistance to bacterial infection in mice

    Energy Technology Data Exchange (ETDEWEB)

    Azoulay-Dupuis, E. (Hopital Claude Bernard, Paris, France); Bouley, G.; Blayo, M.C.

    1982-12-01

    Continuous exposure to approximately a 10-ppm concentration of sulfur dioxide for periods of up to 3 weeks reduced the resistance of female mice to infection by aerosol inoculation with Klebsiella pneumoniae. The mortality rate rose and survival time shortened in SO/sub 2/-exposed animals compared to controls. Insofar as these results can be extrapolated to humans, the SO/sub 2/ concentration used in this work is only found on certain industrial premises.

  6. Sulfur speciation and bioaccumulation in camphor tree leaves as atmospheric sulfur indicator analyzed by synchrotron radiation XRF and XANES

    Institute of Scientific and Technical Information of China (English)

    Jianrong Zeng; Guilin Zhang; Liangman Bao; Shilei Long; Mingguang Tan; Yan Li; Chenyan Ma

    2013-01-01

    Analyzing and understanding the effects of ambient pollution on plants is getting more and more attention as a topic of environmentalbiology.A method based on synchrotron radiation X-ray fluorescence and X-ray absorption near edge structure spectroscopy wasestablished to analyze the sulfur concentration and speciation in mature camphor tree leaves (CTLs),which were sampled from 5 localfields in Shanghai,China.Annual SO2 concentration,SO42-concentration in atmospheric particulate,SO42-and sulfur concentrationin soil were also analyzed to explore the relationship between ambient sulfur sources and the sulfur nutrient cycling in CTLs.Totalsulfur concentration in mature camphor tree leaves was 766-1704 mg/kg.The mainly detected sulfur states and their correspondingcompounds were +6 (sulfate,include inorganic sulfate and organic sulfate),+5.2 (sulfonate),+2.2 (suloxides),+0.6 (thiols andthiothers),+0.2 (organic sulfides).Total sulfur concentration was strongly correlated with sulfate proportion with a linear correlationcoefficient up to 0.977,which suggested that sulfur accumulated in CTLs as sulfate form.Reduced sulfur compounds (organic sulfides,thiols,thioethers,sulfoxide and sulfonate) assimilation was sufficed to meet the nutrient requirement for growth at a balanced levelaround 526 mg/kg.The sulfate accumulation mainly caused by atmospheric sulfur pollution such as SO2 and airborne sulfate particulateinstead of soil contamination.From urban to suburb place,sulfate in mature CTLs decreased as the atmospheric sulfur pollution reduced,but a dramatic increase presented near the seashore,where the marine sulfate emission and maritime activity pollution were significant.The sulfur concentration and speciation in mature CTLs effectively represented the long-term biological accumulation of atmosphericsulfur pollution in local environment.

  7. Integrated boiler, superheater, and decomposer for sulfuric acid decomposition

    Science.gov (United States)

    Moore, Robert; Pickard, Paul S.; Parma, Jr., Edward J.; Vernon, Milton E.; Gelbard, Fred; Lenard, Roger X.

    2010-01-12

    A method and apparatus, constructed of ceramics and other corrosion resistant materials, for decomposing sulfuric acid into sulfur dioxide, oxygen and water using an integrated boiler, superheater, and decomposer unit comprising a bayonet-type, dual-tube, counter-flow heat exchanger with a catalytic insert and a central baffle to increase recuperation efficiency.

  8. Two-step rapid sulfur capture. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-04-01

    The primary goal of this program was to test the technical and economic feasibility of a novel dry sorbent injection process called the Two-Step Rapid Sulfur Capture process for several advanced coal utilization systems. The Two-Step Rapid Sulfur Capture process consists of limestone activation in a high temperature auxiliary burner for short times followed by sorbent quenching in a lower temperature sulfur containing coal combustion gas. The Two-Step Rapid Sulfur Capture process is based on the Non-Equilibrium Sulfur Capture process developed by the Energy Technology Office of Textron Defense Systems (ETO/TDS). Based on the Non-Equilibrium Sulfur Capture studies the range of conditions for optimum sorbent activation were thought to be: activation temperature > 2,200 K for activation times in the range of 10--30 ms. Therefore, the aim of the Two-Step process is to create a very active sorbent (under conditions similar to the bomb reactor) and complete the sulfur reaction under thermodynamically favorable conditions. A flow facility was designed and assembled to simulate the temperature, time, stoichiometry, and sulfur gas concentration prevalent in the advanced coal utilization systems such as gasifiers, fluidized bed combustors, mixed-metal oxide desulfurization systems, diesel engines, and gas turbines.

  9. 40 CFR 180.444 - Sulfur dioxide; tolerances for residues.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Sulfur dioxide; tolerances for residues. 180.444 Section 180.444 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... § 180.444 Sulfur dioxide; tolerances for residues. A tolerance is established as follows for...

  10. Iron-Catalyzed Synthesis of Sulfur-Containing Heterocycles.

    Science.gov (United States)

    Bosset, Cyril; Lefebvre, Gauthier; Angibaud, Patrick; Stansfield, Ian; Meerpoel, Lieven; Berthelot, Didier; Guérinot, Amandine; Cossy, Janine

    2016-10-13

    An iron-catalyzed synthesis of sulfur- and sulfone-containing heterocycles is reported. The method is based on the cyclization of readily available substrates and proceeded with high efficiency and diastereoselectivity. A variety of sulfur-containing heterocycles bearing moieties suitable for subsequent functionalization are prepared. Illustrative examples of such postcyclization modifications are also presented.

  11. Sulfur in human nutrition - effects beyond protein synthesis

    NARCIS (Netherlands)

    Schaafsma, Gertjan

    2008-01-01

    That sulfur is essential to humans is based on the requirement of S-animo acids for normal growth and maintenance of nitrogen balance and not on the optimization of metabolic proccesses involving the synthesis of non-protein sulphur containing compounds. This paper reviews the significance of sulfur

  12. Seed production and dispersal of sulfur cinquefoil in northeast Oregon

    Science.gov (United States)

    Kathleen A. Dwire; Catherine G. Parks; Michael L. McInnis; Bridgett J. Naylor

    2006-01-01

    Sulfur cinquefoil (family Rosaceae) is an invasive, herbaceous perennial, native to Eurasia. It has wide ecological amplitude and has become established throughout North America in numerous habitat types. Sulfur cinquefoil reproduces only by seed (achenes); however, little is known about its regenerative strategy or reproductive biology. To improve understanding of the...

  13. Geochemical evidence for cryptic sulfur cycling in salt marsh sediments

    DEFF Research Database (Denmark)

    Mills, Jennifer V.; Antler, Gilad; Turchyn, Alexandra V.

    2016-01-01

    investigate sulfur cycling in salt marsh sediments from Norfolk, England where we observe high ferrous iron concentrations with no depletion of sulfate or change in the sulfur isotope ratio of that sulfate, but a 5‰ increase in the oxygen isotope ratio in sulfate, indicating that sulfate has been through...

  14. Geochemical evidence for cryptic sulfur cycling in salt marsh sediments

    DEFF Research Database (Denmark)

    Mills, Jennifer V.; Antler, Gilad; Turchyn, Alexandra V.

    2016-01-01

    to represent the salt marsh sediments suggests that the uptake rate of sulfate during this cryptic sulfur cycling is similar to the uptake rate of sulfate during the fastest microbial sulfate reduction that has been measured in the natural environment. The difference is that during cryptic sulfur cycling, all...... investigate sulfur cycling in salt marsh sediments from Norfolk, England where we observe high ferrous iron concentrations with no depletion of sulfate or change in the sulfur isotope ratio of that sulfate, but a 5‰ increase in the oxygen isotope ratio in sulfate, indicating that sulfate has been through...... a reductive cycle replacing its oxygen atoms. This cryptic sulfur cycle was replicated in laboratory incubations using 18O-enriched water, demonstrating that the field results do not solely result from mixing processes in the natural environment. Numerical modeling of the laboratory incubations scaled...

  15. The contribution of aircraft emissions to the atmospheric sulfur budget

    Energy Technology Data Exchange (ETDEWEB)

    Kjellstroem, E. [Stockholm Univ. (Sweden). Dept. of Meteorology; Feichter, J. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Sausen, R.; Hein, R. [Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere

    1998-01-01

    An atmospheric general circulation model including the atmospheric sulfur cycle has been used to investigate the impact of aircraft sulfur emissions on the global sulfur budget of the atmosphere. The relative contribution from aircraft sulfur to the atmospheric sulfate burden is larger than the ratio between aircraft emissions and surface emissions due to the calculated long turn-over time of aircraft sulfate (about 12 days). However, in terms of the sulfate mass balance, aircraft emissions are small, contributing about 1% of the total sulfate mass north of 40 deg C where the aircraft emissions are largest. Despite this small contribution to sulfate mass, the aircraft emissions could potentially significantly enhance the background number concentration of aerosol particles. Based on the model calculations the increased stratospheric background aerosol mass observed during the last decades can not be explained by increased aircraft sulfur emissions 50 refs, 9 figs, 4 tabs

  16. Extraction of mercury(II) with sulfurized jojoba oil

    Energy Technology Data Exchange (ETDEWEB)

    Wisniak, J.; Schorr, G.; Zacovsky, D.; Belfer, S. (Ben-Gurion Univ. of the Negev, Beersheba (Israel). Dept. of Chemical Engineering)

    1990-09-01

    Sulfurized jojoba oil containing 12% by weight S has been tested as an extractant for Hg(II) from aqueous solutions. This paper reports on experiments performed with the extractant dissolved in a solvent (liquid--liquid extraction) or adsorbed in an appropriate resin matrix (solid--liquid extraction). The extraction characteristics of both systems have been measured and show that sulfurized jojoba oil exhibits very good possibilities as an extractant. The performance of several resins treated with sulfurized jojoba oil for adsorbing mercury(II) was studied. The morphology of the different resins was examined by using scanning electron microscopy. The sulfurized oil is attached to the resin sites through the sulfur atoms; it is estimated that there are about 2 mol of S active sites per kilogram of resin.

  17. Biodesulfurization of refractory organic sulfur compounds in fossil fuels.

    Science.gov (United States)

    Soleimani, Mehran; Bassi, Amarjeet; Margaritis, Argyrios

    2007-01-01

    The stringent new regulations to lower sulfur content in fossil fuels require new economic and efficient methods for desulfurization of recalcitrant organic sulfur. Hydrodesulfurization of such compounds is very costly and requires high operating temperature and pressure. Biodesulfurization is a non-invasive approach that can specifically remove sulfur from refractory hydrocarbons under mild conditions and it can be potentially used in industrial desulfurization. Intensive research has been conducted in microbiology and molecular biology of the competent strains to increase their desulfurization activity; however, even the highest activity obtained is still insufficient to fulfill the industrial requirements. To improve the biodesulfurization efficiency, more work is needed in areas such as increasing specific desulfurization activity, hydrocarbon phase tolerance, sulfur removal at higher temperature, and isolating new strains for desulfurizing a broader range of sulfur compounds. This article comprehensively reviews and discusses key issues, advances and challenges for a competitive biodesulfurization process.

  18. Metal-sulfur type cell having improved positive electrode

    Science.gov (United States)

    Dejonghe, Lutgard C.; Visco, Steven J.; Mailhe, Catherine C.; Armand, Michel B.

    1988-03-01

    A novel metal-sulfur type cell operable at a temperature of 200 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.

  19. Sulfur cathodes with hydrogen reduced titanium dioxide inverse opal structure.

    Science.gov (United States)

    Liang, Zheng; Zheng, Guangyuan; Li, Weiyang; Seh, Zhi Wei; Yao, Hongbin; Yan, Kai; Kong, Desheng; Cui, Yi

    2014-05-27

    Sulfur is a cathode material for lithium-ion batteries with a high specific capacity of 1675 mAh/g. The rapid capacity fading, however, presents a significant challenge for the practical application of sulfur cathodes. Two major approaches that have been developed to improve the sulfur cathode performance include (a) fabricating nanostructured conductive matrix to physically encapsulate sulfur and (b) engineering chemical modification to enhance binding with polysulfides and, thus, to reduce their dissolution. Here, we report a three-dimensional (3D) electrode structure to achieve both sulfur physical encapsulation and polysulfides binding simultaneously. The electrode is based on hydrogen reduced TiO2 with an inverse opal structure that is highly conductive and robust toward electrochemical cycling. The relatively enclosed 3D structure provides an ideal architecture for sulfur and polysulfides confinement. The openings at the top surface allow sulfur infusion into the inverse opal structure. In addition, chemical tuning of the TiO2 composition through hydrogen reduction was shown to enhance the specific capacity and cyclability of the cathode. With such TiO2 encapsulated sulfur structure, the sulfur cathode could deliver a high specific capacity of ∼1100 mAh/g in the beginning, with a reversible capacity of ∼890 mAh/g after 200 cycles of charge/discharge at a C/5 rate. The Coulombic efficiency was also maintained at around 99.5% during cycling. The results showed that inverse opal structure of hydrogen reduced TiO2 represents an effective strategy in improving lithium sulfur batteries performance.

  20. Utilization of fumarate by sulfur-reducing bacteria Desulfuromonas sp.

    Directory of Open Access Journals (Sweden)

    O. Сhayka

    2016-08-01

    Full Text Available The main goal of the work was to study the utilization of fumarate by sulfur-reducing bacteria Desulfuromonas sp. under different growth conditions and accumulation of hydrogen sulfide by bacteria in the media with sulfur and different electron donors. Sulfur-reducing bacteria Desulfuromonas sp., isolated from soil in Yazivske sulfur deposit, were used in the reasearch. Bacteria were grown in the medium Postgate C without sulfates. The content of hydrogen sulfide was determined by formation of methylene blue. The content of organic acids (fumarate, succinate, lactate, acetate was determined by high performance liquid chromatography (HPLC. The biomass of cells was determined by the photoelectrocolorymetry method using KFK-3. The highest level of accumulation of hydrogen sulfide by bacteria Desulfuromonas sp. was found in media with sodium lactate and sodium pyruvate. The maximal concentration of hydrogen sulfide was 1.9 mM. Maximal accumulation of biomass was observed in the media with malate, lactate and fumarate with the presence of elemental sulfur. Sulfur-reducing bacteria Desulfuromonas sp. are able to utilize fumarate as an electron donor and acceptor in the absence of elemental sulfur in the medium. After the incubation of Desulfuromonas sp. in the medium with fumarate, chromatographic analysis of culture liquid showed that fumarate is converted to succinate and small quantities of acetate The presence of acetate is, probably, due to the particularaties of the functioning of citric acid cycle in bacteria of the genus Desulfuromonas. Consequently, the results indicate that the fumarate serves as a donor and acceptor of electrons.The simultaneous introduction of two electron donors – fumarate and elemental sulfur – was accompanied by inhibition of sulfur reduction. After an additional source of carbon (sodium lactate and electron acceptor (elemental sulfur was added to the medium with fumarate a fivefold increase of sulfidogenic

  1. Enhanced cyclability of sulfur cathodes in lithium-sulfur batteries with Na-alginate as a binder

    Institute of Scientific and Technical Information of China (English)

    Weizhai; Bao; Zhian; Zhang; Yongqing; Gan; Xiwen; Wang; Jie; Lia

    2013-01-01

    Na-alginate as a binder in an aqueous solvent has been applied in the preparation of sulfur cathodes for lithium-sulfur batteries.Their electrochemical performances have been investigated by a charge-discharge cycle test and electrochemical impedance spectroscopy (EIS).The EIS tests indicated that the alginate sulfur cathode had lower resistance and better kinetic characteristics than those of the poly (vinylidene fluoride) (PVDF) sulfur cathode using PVDF as a binder in a N-methy-2-pyrrolidone (NMP) solvent.The charge-discharge tests showed that the discharge capacity and the capacity retention rate of Na-alginate sulfur cathode were 508 mAh·g-1and 65.4% at the 50th cycle with a current density of 335 mA·g-1.Compared with PVDF sulfur cathode,the alginate sulfur cathode showed a remarkably better cycle performance.These results show that the alginate binder has promising potential for lithium-sulfur battery applications.

  2. 1H NMR of High-Potential Iron-Sulfur Protein from the Purple Non-Sulfur Bacterium Rhodoferax fermentans

    DEFF Research Database (Denmark)

    Ciurli, Stefano; Cremonini, Mauro Andrea; Kofod, Pauli

    1996-01-01

    Oxidized and reduced forms of high-potential iron-sulfur protein (HiPIP) from the purple non-sulfur photosynthetic bacterium Rhodoferux fermentans have been characterized using 1H-NMR spectroscopy. Pairwise and sequence-specific assignments of hyperfine-shifted 1H-NMR signals to protons of cysteine...

  3. MATHEMATICAL SIMULATION OF THE INTERACTIONS AMONG CYANOBACTERIA, PURPLE SULFUR BACTERIA AND CHEMOTROPIC SULFUR BACTERIA IN MICROBIAL MAT COMMUNITIES

    NARCIS (Netherlands)

    DEWIT, R; VANDENENDE, FP; VANGEMERDEN, H

    1995-01-01

    A deterministic one-dimensional reaction diffusion model was constructed to simulate benthic stratification patterns and population dynamics of cyanobacteria, purple and colorless sulfur bacteria as found in marine microbial mats. The model involves the major biogeochemical processes of the sulfur c

  4. MATHEMATICAL SIMULATION OF THE INTERACTIONS AMONG CYANOBACTERIA, PURPLE SULFUR BACTERIA AND CHEMOTROPIC SULFUR BACTERIA IN MICROBIAL MAT COMMUNITIES

    NARCIS (Netherlands)

    DEWIT, R; VANDENENDE, FP; VANGEMERDEN, H

    1995-01-01

    A deterministic one-dimensional reaction diffusion model was constructed to simulate benthic stratification patterns and population dynamics of cyanobacteria, purple and colorless sulfur bacteria as found in marine microbial mats. The model involves the major biogeochemical processes of the sulfur c

  5. MATHEMATICAL SIMULATION OF THE INTERACTIONS AMONG CYANOBACTERIA, PURPLE SULFUR BACTERIA AND CHEMOTROPIC SULFUR BACTERIA IN MICROBIAL MAT COMMUNITIES

    NARCIS (Netherlands)

    DEWIT, R; VANDENENDE, FP; VANGEMERDEN, H

    A deterministic one-dimensional reaction diffusion model was constructed to simulate benthic stratification patterns and population dynamics of cyanobacteria, purple and colorless sulfur bacteria as found in marine microbial mats. The model involves the major biogeochemical processes of the sulfur

  6. Amine reactivity with charged sulfuric acid clusters

    Directory of Open Access Journals (Sweden)

    B. R. Bzdek

    2011-05-01

    Full Text Available The distribution of ionic species produced by electrospray of an ammonium sulfate solution in both positive and negative polarities is examined using Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS. Positively-charged ammonium bisulfate cluster composition differs significantly from negatively-charged cluster composition. For positively-charged clusters all sulfuric acid is neutralized to bisulfate, whereas for negatively-charged clusters the degree of sulfuric acid neutralization is cluster size-dependent. With increasing cluster size (and, therefore, a decreasing role of charge, both positively- and negatively-charged cluster compositions converge toward ammonium bisulfate. The reactivity of negatively-charged sulfuric acid-ammonia clusters with dimethylamine and ammonia are also investigated by FTICR-MS. Two series of negatively-charged clusters are investigated: [(HSO4(H2SO4x] and [(NH4x(HSO4x+1(H2SO43]. Dimethylamine substitution for ammonia in [(NH4x(HSO4x+1(H2SO43] clusters is nearly collision-limited, and subsequent addition of dimethylamine to neutralize H2SO4 is within one order of magnitude of the substitution rate. Dimethylamine addition to [(HSO4(H2SO4x]clusters is either not observed or very slow. The results of this study indicate that amine chemistry will be evident and important only in large ambient negative ions (> m/z 400, whereas amine chemistry may be evident in small ambient positive ions. Addition of ammonia to unneutralized clusters occurs at a rate that is ~2–3 orders of magnitude slower than incorporation of dimethylamine either by

  7. Amine reactivity with charged sulfuric acid clusters

    Directory of Open Access Journals (Sweden)

    B. R. Bzdek

    2011-08-01

    Full Text Available The distribution of charged species produced by electrospray of an ammonium sulfate solution in both positive and negative polarities is examined using Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS. Positively-charged ammonium bisulfate cluster composition differs significantly from negatively-charged cluster composition. For positively-charged clusters all sulfuric acid is neutralized to bisulfate, whereas for negatively-charged clusters the degree of sulfuric acid neutralization is cluster size-dependent. With increasing cluster size (and, therefore, a decreasing role of charge, both positively- and negatively-charged cluster compositions converge toward ammonium bisulfate. The reactivity of negatively-charged sulfuric acid-ammonia clusters with dimethylamine and ammonia is also investigated by FTICR-MS. Two series of negatively-charged clusters are investigated: [(HSO4(H2SO4x] and [(NH4x(HSO4x+1(H2SO43]. Dimethylamine substitution for ammonia in [(NH4 x(HSO4 x+1(H2SO43] clusters is nearly collision-limited, and subsequent addition of dimethylamine to neutralize H2SO4 to bisulfate is within one order of magnitude of the substitution rate. Dimethylamine addition to [(HSO4 (H2SO4 x] clusters is either not observed or very slow. The results of this study indicate that amine chemistry will be evident and important only in large ambient negative ions (>m/z 400, whereas amine chemistry may be evident in small ambient positive ions. Addition of ammonia to unneutralized clusters occurs at a rate that is ~2–3 orders of magnitude slower than incorporation of dimethylamine either by substitution or addition

  8. Experimental and thermodynamic investigation on transfer of cadmium influenced by sulfur and chlorine during municipal solid waste (MSW) incineration.

    Science.gov (United States)

    Zhang, Yanguo; Chen, Yong; Meng, Aihong; Li, Qinghai; Cheng, Hefa

    2008-05-01

    We used two approaches to investigate the impact of sulfur and chlorine compounds on transfer of a semivolatile heavy metal, cadmium, during municipal solid waste (MSW) incineration: experiments using a tubular furnace reactor and thermodynamic equilibrium calculations. Artificial wastes representative of typical MSW in China with and without the presence of sulfur and chlorine compounds were combusted at 850 degrees C, and the partitioning of Cd among bottom ash, fly ash and flue gas was quantified. The results indicate that sulfur compounds in the elemental form and reduced state could stabilize Cd in the form of CdS due to local reducing environment, while sulfur in the oxidized forms slightly increased Cd volatilization during incineration. In contrast, the presence of chlorine compounds significantly increased the partitioning of Cd on fly ash. Chemical equilibrium calculations show that sulfur binds with Cd and alters Cd speciation at low temperatures (<700 degrees C), while chlorine significantly increases the volatilization of Cd through formation of volatile CdCl(2) and thus its partitioning on the fly ash between 400 and 1000 degrees C. The equilibrium calculation results also suggest that SiO(2)- and Al(2)O(3)-containing minerals could function as sorbents stabilizing Cd as condensed phase solids (CdSiO(3) and CdAl(2)O(4)). These findings provide useful information on understanding the partitioning behavior of Cd and can help development of strategies to control volatilization of Cd during MSW incineration.

  9. High sulfur content polymer nanoparticles obtained from interfacial polymerization of sodium polysulfide and 1,2,3-trichloropropane in water.

    Science.gov (United States)

    Lim, Jeewoo; Jung, Unho; Joe, Won Tae; Kim, Eui Tae; Pyun, Jeffrey; Char, Kookheon

    2015-06-01

    Sulfur-rich materials have recently attracted keen interest for their potentials in optical, electrochemical, and pesticidal applications as well as their utility in dynamic covalent bond chemistry. Many sulfur-rich polymers, however, are insoluble and processing methods are therefore very limited. The synthesis and characterization of water-dispersible polymer nanoparticles (NPs) with the sulfur content exceeding 75% by weight, obtained from the interfacial polymerization between 1,2,3-trichloropropane and sodium polysulfide in water is reported here. The interfacial polymerization yields well-defined sulfur-rich NPs in the presence of surfactants, which are capable of serving a dual role as a phase transfer catalyst on top of emulsifiers. Such dual role allows for the control of the product NP size by varying its concentration. The surfactants can be easily removed by centrifugation and redispersion in water is also reported here. The resulting sulfur-rich NPs are characterized through elemental analysis, dynamic light scattering, ζ-potential measurements, and scanning electron microscopy.

  10. Two standardized methods for the determination of sulfur dioxide in the atmosphere, and statistical study on analytical methods

    Energy Technology Data Exchange (ETDEWEB)

    Anechina, P.; Alvarez, S.; Merchan, M.L.; De La Serna, J.

    1974-01-01

    The reliability of the thorin method for the measurement of atmospheric sulfur dioxide was evaluated. The calibration curve is obtained using a series of standard samples in duplicate, from 0 to 8 micrograms of SO/sub 2//ml. These standards samples are obtained by adding aliquots of 0.1 N solution of sulfuric acid to the absorption solution. The line of best fit is determined using the regression analysis by the method of minimal squares. Three control samples were measured daily from calculated volumes of 0.1 N solution H/sub 2/SO/sub 4/, equivalents to 2, 5, and 8 micrograms of SO/sub 2//ml.

  11. Succession of Sulfur-Oxidizing Bacteria in the Microbial Community on Corroding Concrete in Sewer Systems† ▿

    OpenAIRE

    Okabe, Satoshi; Odagiri, Mitsunori; Ito, Tsukasa; Satoh, Hisashi

    2007-01-01

    Microbially induced concrete corrosion (MICC) in sewer systems has been a serious problem for a long time. A better understanding of the succession of microbial community members responsible for the production of sulfuric acid is essential for the efficient control of MICC. In this study, the succession of sulfur-oxidizing bacteria (SOB) in the bacterial community on corroding concrete in a sewer system in situ was investigated over 1 year by culture-independent 16S rRNA gene-based molecular ...

  12. Sulfur isotopes in coal constrain the evolution of the Phanerozoic sulfur cycle

    DEFF Research Database (Denmark)

    Canfield, Donald Eugene

    2013-01-01

    Sulfate is the second most abundant anion (behind chloride) in modern seawater, and its cycling is intimately coupled to the cycling of organic matter and oxygen at the Earth’s surface. For example, the reduction of sulfide by microbes oxidizes vast amounts of organic carbon and the subsequent...... reaction of sulfide with iron produces pyrite whose burial in sediments is an important oxygen source to the atmosphere. The concentrations of seawater sulfate and the operation of sulfur cycle have experienced dynamic changes through Earth’s history, and our understanding of this history is based mainly...... on interpretations of the isotope record of seawater sulfates and sedimentary pyrites. The isotope record, however, does not give a complete picture of the ancient sulfur cycle. This is because, in standard isotope mass balance models, there are more variables than constraints. Typically, in interpretations...

  13. Implicit nucleophilic reagents in the sulfur dioxide-amine system. Sulfur trioxide treatment of azomethines

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Sulfur balance of sulfur dioxide-ethanol-water fractionation of sugarcane straw.

    Science.gov (United States)

    You, Xiang; van Heiningen, Adriaan; Sixta, Herbert; Iakovlev, Mikhail

    2017-10-01

    The sulfur balance of SO2-ethanol-water (AVAP®) fractionation of sugarcane (SC) straw was investigated. Hydrogen sulfite and sulfite anions are nearly absent in the liquors, despite cations present in straw, whose effect is thus limited to neutralization of lignosulfonic acids decreasing the acidity. Higher degree of sulfonation was observed for dissolved straw lignin compared to wood lignin (0.8-0.9 vs. 0.25 S/C9). Sulfur dioxide amounts of 0.9-1.2, 4.1-4.3 and 44-49g per o.d.kg straw were bound to pulp, precipitated lignin and lignosulfonic acid, respectively, while the rest of SO2 was recovered by distillation from the spent fractionation suspensions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. A sulfur host based on titanium monoxide@carbon hollow spheres for advanced lithium-sulfur batteries

    Science.gov (United States)

    Li, Zhen; Zhang, Jintao; Guan, Buyuan; Wang, Da; Liu, Li-Min; Lou, Xiong Wen (David)

    2016-10-01

    Lithium-sulfur batteries show advantages for next-generation electrical energy storage due to their high energy density and cost effectiveness. Enhancing the conductivity of the sulfur cathode and moderating the dissolution of lithium polysulfides are two key factors for the success of lithium-sulfur batteries. Here we report a sulfur host that overcomes both obstacles at once. With inherent metallic conductivity and strong adsorption capability for lithium-polysulfides, titanium monoxide@carbon hollow nanospheres can not only generate sufficient electrical contact to the insulating sulfur for high capacity, but also effectively confine lithium-polysulfides for prolonged cycle life. Additionally, the designed composite cathode further maximizes the lithium-polysulfide restriction capability by using the polar shells to prevent their outward diffusion, which avoids the need for chemically bonding all lithium-polysulfides on the surfaces of polar particles.

  16. 40 CFR 52.1126 - Control strategy: Sulfur oxides.

    Science.gov (United States)

    2010-07-01

    ... Insurance Company, Springfield. Northampton State Hospital, Northampton. Springfield Technical Community..., Bridgewater. Hanscom Field, Bedford. Wellesley College, Wellesley. National Tanning and Trading, Peabody...

  17. STREAMWATER ACID-BASED CHEMISTRY AND CRITICAL LOADS OF ATMOSPHERIC SULFUR DEPOSITION IN SHENANDOAH NATIONAL PARK, VIRGINIA

    Science.gov (United States)

    A modeling study was conducted to evaluate the acid-base chemistry of streams within Shenandoah National Park, Virginia and to project future responses to sulfur (S) and nitrogen (N) atmospheric emissions controls. Many of the major stream systems in the Park have acid neutraliz...

  18. Limestone treatment for sulfur dioxide removal. (Latest citations from the EI compendex*plus database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    The bibliography contains citations concerning the use of limestone for the control of sulfur dioxide emmisions in flue gases. The various designs for flue gas desulfurization are discussed, including dry fluidized beds and wet scrubbers. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  19. Experimental Study on Treatment of High-concentrated Sulfur Wastewater by Process of Depositing Natrojarosite and Its Environmental Significance

    Institute of Scientific and Technical Information of China (English)

    MA Shengfeng; WANG Changqiu; LU Anhuai; GUO Yanjun; HE Hongliao

    2007-01-01

    High-concentrated sulfur wastewater with sodium and COD (chemical oxygen demand) up to 26000 mg/L from a chemical plant, Jiangsu Province of China has been treated by deposition of natrojarosite in lab. The results indicated that the COD of the wastewater was decreased sharply from 26000 mg/L to 1001 mg/L, with removal rate of COD up to 96% by twice precipitations of natrojarosite and twice oxidation of H2O2. The treated sulfur wastewater reached the requirement of subsequent biochemical treatment to water quality. The optimal operational parameters should be controlled on provided an experimental basis for pretreatment of high-concentrated sulfur wastewater and proposed a new mineralogical method on treatment of other wastewaters. Depositing process ofjarosite and its analogs should be able to be used to treat wastewater from mine and other industries to remove S, Fe and other toxic and harmful elements, such as As, Cr, Hg, Pb, etc. in the water.

  20. Mechanisms and evolution of oxidative sulfur metabolism in green sulfur bacteria

    Directory of Open Access Journals (Sweden)

    Lea Haarup Gregersen

    2011-05-01

    Full Text Available Green sulfur bacteria (GSB constitute a closely related group of photoautotrophic and thiotrophic bacteria with limited phenotypic variation. They typically oxidize sulfide and thiosulfate to sulfate with sulfur globules as an intermediate. Based on genome sequence information from 15 strains, the distribution and phylogeny of enzymes involved in their oxidative sulfur metabolism was investigated. At least one homolog of sulfide:quinone oxidoreductase (SQR is present in all strains. In all sulfur-oxidizing GSB strains except the earliest diverging Chloroherpeton thalassium, the sulfide oxidation product is further oxidized to sulfite by the dissimilatory sulfite reductase (DSR system. This system consists of components horizontally acquired partly from sulfide-oxidizing and partly from sulfate-reducing bacteria. Depending on the strain, the sulfite is probably oxidized to sulfate by one of two different mechanisms that have different evolutionary origins: adenosine-5’-phosphosulfate reductase (APR or polysulfide reductase-like complex 3 (PSRLC3. Thiosulfate utilization by the SOX system in GSB has apparently been acquired horizontally from proteobacteria. SoxCD does not occur in GSB, and its function in sulfate formation in other bacteria has been replaced by the DSR system in GSB. Sequence analyses suggested that the conserved soxJXYZAKBW gene cluster was horizontally acquired by Chlorobium phaeovibrioides DSM 265 from the Chlorobaculum lineage and that this acquisition was mediated by a mobile genetic element. Thus, the last common ancestor of currently known GSB was probably photoautotrophic, hydrogenotrophic, and contained SQR but not DSR or SOX. In addition, the predominance of the Chlorobium-Chlorobaculum-Prosthecochloris lineage among cultured GSB could be due to the horizontally acquired DSR and SOX systems. Finally, based upon structural, biochemical, and phylogenetic analyses, a uniform nomenclature is suggested for sqr genes in

  1. Massive atmospheric sulfur loading of the AD 1600 Huaynaputina eruption and implications for petrologic sulfur estimates.

    OpenAIRE

    Costa Rodriguez, Fidel; Scaillet, Bruno; Gourgaud, Alain

    2003-01-01

    International audience; We combine petrological, analytical, and thermodynamical data to constrain the sulfur yield of the AD 1600 Huaynaputina eruption which has been associated with the largest Earth's temperature shift in the last 600 years. The calculated amount of S (26–55 Tg), partly overlaps, but ranges to almost twice the amount estimated from ice-core data (16–32 Tg), the higher values of our estimate probably reflect that not all S released by the eruption reached the stratosphere. ...

  2. Resistance to injury by sulfur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Sekiya, J.; Wilson, L.G.; Filner, P.

    1982-08-01

    In Cucurbitaceae young leaves are resistant to injury from acute exposure to SO/sub 2/, whereas mature leaves are sensitive. After exposure of cucumber (Cucumis sativus L.) plants to SO/sub 2/ at injurious concentrations, illuminated leaves emit volatile sulfur, which is solely H/sub 2/S. Young leaves emit H/sub 2/S many times more rapidly than do mature leaves. Young leaves convert approximately 10% of absorbed (/sup 35/S)SO/sub 2/ to emitted (/sup 35/S)H/sub 2/S, but mature leaves convert less than 2%. These results suggest that a high capability for the reduction of SO/sub 2/ to H/sub 2/S and emission of the H/sub 2/S is a part of the biochemical basis of the resistance of young leaves to SO/sub 2/.

  3. Sulfur-containing trinuclear arene ruthenium clusters

    OpenAIRE

    Tschan, Mathieu; Therrien, Bruno; Chérioux, Frédéric; Süss-Fink, Georg

    2006-01-01

    The single-crystal X-ray structure analyses of [HRu3(C6H6)(C6Me6)2(μ3-SC6H4Me)(μ2-O)][BF4]2 ([1][BF4]2), [HRu3(C6H6)(C6Me6)2(μ3-SC6H4Me)(μ2-S)][PF6]2 ([2][PF6]2) and [H2Ru3(1,2,4,5-Me4C6H2)3(μ2-S)(Cl)]PF6([3][PF6]) are presented. The structures show the sulfur ligands to act as bridges between ruthenium atoms. In [1][BF4]2 and [2][PF6]2 the metallic core adopts a nido framework. However, in [3][PF6] the absence of a μ3-SR ligand combined with the presence of one terminal chloro unit gives ris...

  4. Effect of sulfur dioxide fumes on plants

    Energy Technology Data Exchange (ETDEWEB)

    Zimmerman, P.W.; Cracker, W.

    1930-12-01

    Sulfur dioxide injured the foliage of all the plants tested. Injury in the form of brown or withered areas usually appeared first along the margins of the leaves, then between the veins. Regions along the main veins frequently resisted high concentrations. After a one hour treatment in 3-4 ppm of SO/sub 2/ leaves were injured on tomato, salvia, coleus, geranium, castor bean, roses, and several other plants. The same plants in a slightly wilted condition were not injured by 8 ppm after a five hour treatment. Middle-aged leaves were more sensitive than either young or old leaves. Orchid foliage showed no injury after a four hour treatment in 70 ppm, but a high concentration for a longer period injured the leaves and some of the exposed roots.

  5. Helium and Sulfur Hexafluoride in Musical Instruments

    Science.gov (United States)

    Forinash, Kyle; Dixon, Cory L.

    2014-11-01

    The effects of inhaled helium on the human voice were investigated in a recent article in The Physics Teacher.1 As mentioned in that article, demonstrations of the effect are a popular classroom activity. If the number of YouTube videos is any indication, the effects of sulfur hexafluoride on the human voice are equally popular. However, there appears to be little information available on the effects of either of these gases on musical instruments.2 We describe here the results of a student project that involved measuring the frequency shifts in an organ pipe, a trumpet, and a trombone as the result of filling the instruments with these two gases. The project was one of several possible end-of-semester projects required in an elective science of sound course for non-science majors.

  6. Sulfur technology update: selected research topics from the ASRL core research program

    Energy Technology Data Exchange (ETDEWEB)

    Clark, P. D.; Dowling, N. I.; Marriott, R.A.; Primak, A.; Davis, P.M. [Alberta Sulphur Research Ltd (Canada)

    2011-07-01

    This conference presentation is a combined effort by Alberta Sulfur Research, Ltd (ASRL) and the University of Calgary; it focuses on sulfur production technology and the ongoing research behind it. This presentation deals mainly with the use of sulfur in the oil sand industry, sulfur recovery in Claus systems, and sulfur management issues. Sulfur formation, mainly in the form of hydrogen sulfide, and the use of liquid sulfur in bitumen coking in the petrochemical industries were discussed first. This was later followed by an illustration of how sulfur recovery efficiency is greatly enhanced by catalytic tail gas incineration and improved liquid sulfur degassing technologies. A comparative scheme between the current process and the new research in utilizing sulfur in nickel metal production was also presented, showing how the new research results in less waste. In conclusion, the effects of polymeric sulfur on the strength of the solid were discussed, showing a linear relationship between the two parameters.

  7. Sulfur and nitrogen compounds in urban aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Tanner, R L

    1979-01-01

    This paper reports results from a detailed chemical and meteorological data base that has been accumulated for the New York City subregion. Aerosol sampling during August 1976 and February 1977 sampling periods was done only in an urban New York site and a background site at High Point, NJ. The sampling program was expanded to Brookhaven (Long Island) and New Haven, Connecticut sites during summer 1977 and winter 1978 sampling. Time resolution for aerosol filter samples was 6 hr, with some 3 hr sampling for the latter three periods. Parameters measured included chemical constituents: strong acid (quartz filters only), ammonium, sulfate and nitrate, sulfuric acid (limited data); physical parameters: aerosol size distributions by cascade impactor, cyclone sampler, EAA, on optical counter and a special diffusion battery-CNC apparatus; light scattering nephelometer and other instrumentation; chemically-speciated size classification by diffusion sampler; trace metals by atomic absorption; halogen compounds by NAA; meteorological measurements of RH, temperature, wind speed and direction; gaseous measurements of SO/sub 2/, ozone, NO/sub x/ and hydrocarbons at some locations for some sampling periods. The existence of aerosol sulfate in the ambient environment predominantly in the chemical form of sulfuric acid mostly neutralized by ammonia is now well documented. The average composition of fine particle (< 3.5 ..mu..m) sulfate in summer 1976 aerosols was approximately that letovicite ((NH/sub 4/)/sub 3/H(SO/sub 4/)/sub 2/). Based on the impactor data, about 85% of the aerosol sulfate mass was in the fine particle fraction. About 50% of this aerosol sulfate was deduced to be in the suboptical size regime (< 0.25 ..mu..m) from diffusion processor data. The H/sup +//SO/sub 4//sup 2 -/ ratio in suboptical aerosols did not significantly differ from that in fine fraction aerosol. The coarse particle sulfate was not associated with H/sup +/ or NH/sub 4//sup +/ and comprised

  8. Sulfur Transfer through an Arbuscular Mycorrhiza1

    Science.gov (United States)

    Allen, James W.; Shachar-Hill, Yair

    2009-01-01

    Despite the importance of sulfur (S) for plant nutrition, the role of the arbuscular mycorrhizal (AM) symbiosis in S uptake has received little attention. To address this issue, 35S-labeling experiments were performed on mycorrhizas of transformed carrot (Daucus carota) roots and Glomus intraradices grown monoxenically on bicompartmental petri dishes. The uptake and transfer of 35SO42− by the fungus and resulting 35S partitioning into different metabolic pools in the host roots was analyzed when altering the sulfate concentration available to roots and supplying the fungal compartment with cysteine (Cys), methionine (Met), or glutathione. Additionally, the uptake, transfer, and partitioning of 35S from the reduced S sources [35S]Cys and [35S]Met was determined. Sulfate was taken up by the fungus and transferred to mycorrhizal roots, increasing root S contents by 25% in a moderate (not growth-limiting) concentration of sulfate. High sulfate levels in the mycorrhizal root compartment halved the uptake of 35SO42− from the fungal compartment. The addition of 1 mm Met, Cys, or glutathione to the fungal compartment reduced the transfer of sulfate by 26%, 45%, and 80%, respectively, over 1 month. Similar quantities of 35S were transferred to mycorrhizal roots whether 35SO42−, [35S]Cys, or [35S]Met was supplied in the fungal compartment. Fungal transcripts for putative S assimilatory genes were identified, indicating the presence of the trans-sulfuration pathway. The suppression of fungal sulfate transfer in the presence of Cys coincided with a reduction in putative sulfate permease and not sulfate adenylyltransferase transcripts, suggesting a role for fungal transcriptional regulation in S transfer to the host. A testable model is proposed describing root S acquisition through the AM symbiosis. PMID:18978070

  9. Sulfur Isotope of Epilithic Mosses to Trace Variation of Atmospheric Sulfur Sources

    Directory of Open Access Journals (Sweden)

    HU Fei-fei1,2;PAN Jia-yong1,3;ZHANG Liang1,2;XIE Shu-rong3;CHEN Yi-ping3;XIA Fei1,3

    2016-08-01

    Full Text Available 全文: PDF (5099 KB HTML (1 KB 输出: BibTeX | EndNote (RIS 摘要 为探讨石生苔藓硫同位素组成特征对区域性大气硫源的指示作用,连续两年采集鄱阳湖生态经济区内的石生苔藓样品,测定δ34S值;并结合已有的雨水、煤的硫同位素值等相关研究数据进行对比分析。样品δ34S值均偏正,平均为+4.9‰,取值范围为+1.9‰~+9.6‰;石生苔藓δ34S值与空气中SO2浓度呈负相关关系;南昌、抚州两市苔藓δ34S值的取值范围与其对应城市大气降水δ34S值的变化区间相接近;研究区内土壤相对富集重硫,且土壤中可溶性硫主要受大气硫沉降影响。结果表明,石生苔藓的硫同位素组成对区域性大气硫源具有指示意义,鄱阳湖生态经济区大气硫沉降的硫源主要来自人为成因硫和生物成因硫,可能还有远距离传输硫等其他硫源的影响。 服务 把本文推荐给朋友 加入我的书架 加入引用管理器 E-mail Alert RSS 作者相关文章 胡菲菲 潘家永 张良 谢淑容 陈益平 夏菲 关键词 : 石生苔藓, 硫同位素, 大气硫源 Abstract: The variation of atmospheric sulfur sources in Poyang Lake Eco-economic Region was explored by sulfur isotopes in epilithic mosses which collected from the research area during 2012 to 2013, and then compared it with the existing research δ34S values of rain and coal. The results showed that all of the δ34S values of epilithic mosses performed as positive value at a range of 1.9‰ to 9.6‰, the average was 4.9‰. It was found a significant negative correlation existed between the δ34S values of epilithic mosses (x and atmospheric SO2 concentration (y (y=-82.61x+7.63, R2=0.85. The δ34S values of epilithic mosses in Nanchang and Fuzhou were close to the δ34S values of its corresponding city’s atmospheric precipitation. The δ34S values of soil total sulfur were higher than that of epilithic mosses

  10. Graphene/Sulfur/Carbon Nanocomposite for High Performance Lithium-Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    Kangke Jin

    2015-09-01

    Full Text Available Here, we report a two-step synthesis of graphene/sulfur/carbon ternary composite with a multilayer structure. In this composite, ultrathin S layers are uniformly deposited on graphene nanosheets and covered by a thin layer of amorphous carbon derived from β-cyclodextrin on the surface. Such a unique microstructure, not only improves the electrical conductivity of sulfur, but also effectively inhibits the dissolution of polysulfides during charging/discharging processes. As a result, this ternary nanocomposite exhibits excellent electrochemical performance. It can deliver a high initial discharge and charge capacity of 1410 mAh·g−1 and 1370 mAh·g−1, respectively, and a capacity retention of 63.8% can be achieved after 100 cycles at 0.1 C (1 C = 1675 mA·g−1. A relatively high specific capacity of 450 mAh·g−1 can still be retained after 200 cycles at a high rate of 2 C. The synthesis process introduced here is simple and broadly applicable to the modification of sulfur cathode for better electrochemical performance.

  11. Biomolecule-assisted synthesis of carbon nitride and sulfur-doped carbon nitride heterojunction nanosheets: An efficient heterojunction photocatalyst for photoelectrochemical applications.

    Science.gov (United States)

    Tao, Hua Bing; Yang, Hong Bin; Chen, Jiazang; Miao, Jianwei; Liu, Bin

    2014-01-01

    A biomolecule-assisted pyrolysis method has been developed to synthesize sulfur-doped graphitic carbon nitride (CNS) nanosheets. During the synthesis, sulfur could be introduced as a dopant into the lattice of carbon nitride (CN). Sulfur doping changed the texture as well as relative band positions of CN. By growing CN on preformed sulfur-doped CN nanosheets, composite CN/CNS heterojunction nanosheets were constructed, which significantly enhanced the photoelectrochemical performance as compared with various control counterparts including CN, CNS and physically mixed CN and CNS (CN+CNS). The enhanced photoelectrochemical performance of CN/CNS heterojunction nanosheets could be ascribed to the efficient separation of photoexcited charge carriers across the heterojunction interface. The strategy of designing and preparing CN/CNS heterojunction photocatalysts in this work can open up new directions for the construction of all CN-based heterojunction photocatalysts.

  12. Membranes for the Sulfur-Iodine Integrated Laboratory Scale Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Frederick F. Stewart

    2007-08-01

    INL has developed polymeric membrane-based chemical separations to enable the thermochemical production of hydrogen. Major activities included studies of sulfuric acid concentration membranes, hydriodic acid concentration membranes, SO2/O2 separation membranes, potential applications of a catalyst reactor system for the decomposition of HI, and evaluation of the chemical separation needs for alternate thermochemical cycles. Membranes for the concentration of sulfuric acid were studied using pervaporation. The goal of this task was to offer the sulfur-iodine (S-I) and the hybrid sulfur (HyS) cycles a method to concentrate the sulfuric acid containing effluent from the decomposer without boiling. In this work, sulfuric acid decomposer effluent needs to be concentrated from ~50 % acid to 80 %. This task continued FY 2006 efforts to characterize water selective membranes for use in sulfuric acid concentration. In FY 2007, experiments were conducted to provide specific information, including transmembrane fluxes, separation factors, and membrane durability, necessary for proper decision making on the potential inclusion of this process into the S-I or HyS Integrated Laboratory Scale demonstration.

  13. Capital cost: low and high sulfur coal plants; 800 MWe

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-01-01

    The Commercial Electric Power Cost Study for 800-MWe (Nominal) low- and high-sulfur coal plants consists of three volumes. (This the fourth subject in a series of eight performed in the Commercial Electric Power Cost Studies by the US NRC). The low-sulfur coal plant is described in Volumes I and II (this volume), while Volume III describes the high-sulfur coal plant. The design basis and cost estimate for the 801-MWe low-sulfur coal plant is presented in Volume I and the drawings, equipment list, and site description are contained in this document. The design basis, drawings, and summary cost estimate for a 794-MWe high-sulfur coal plant are presented in Volume III. This information was developed by redesigning the low-sulfur sub-bituminous coal plant for burning high-sulfur bituminous coal. The reference design includes a lime flue gas desulfurization system. These coal plants utilize a mechanical draft (wet) cooling tower system for condenser heat removal. Costs of alternate cooling systems are provided in Report No. 7 in this series of studies of costs of commercial electrical power plants.

  14. Resistance of biofilm-covered mortars to microbiologically influenced deterioration simulated by sulfuric acid exposure

    Energy Technology Data Exchange (ETDEWEB)

    Soleimani, Sahar, E-mail: ssoleima@connect.carleton.ca; Isgor, O. Burkan, E-mail: burkan_isgor@carleton.ca; Ormeci, Banu, E-mail: banu_ormeci@carleton.ca

    2013-11-15

    Following the reported success of biofilm applications on metal surfaces to inhibit microbiologically influenced corrosion, effectiveness and sustainability of E. coli DH5α biofilm on mortar surface to prevent microbiologically influenced concrete deterioration (MICD) are investigated. Experiments simulating microbial attack were carried out by exposing incrementally biofilm-covered mortar specimens to sulfuric acid solutions with pH ranging from 3 to 6. Results showed that calcium concentration in control reactors without biofilm was 23–47% higher than the reactors with biofilm-covered mortar. Formation of amorphous silica gel as an indication of early stages of acid attack was observed only on the control mortar specimens without biofilm. During acidification, the biofilm continued to grow and its thickness almost doubled from ∼ 30 μm before acidification to ∼ 60 μm after acidification. These results demonstrated that E. coli DH5α biofilm was able to provide a protective and sustainable barrier on mortar surfaces against medium to strong sulfuric acid attack. -- Highlights: •Effectiveness of E.coli DH5α biofilm to prevent MICD was studied. •Conditions that lead to MICD were simulated by chemical acidification. •Biofilm-covered mortar specimens were exposed to sulfuric acid solutions. •The presence of biofilm helped reduce the chemically-induced mortar deterioration. •Biofilm remained alive and continued to grow during the acidification process.

  15. Thoracic Duct Chylous Fistula Following Severe Electric Injury Combined with Sulfuric Acid Burns: A Case Report

    Science.gov (United States)

    Chang, Fei; Cheng, Dasheng; Qian, Mingyuan; Lu, Wei; Li, Huatao; Tang, Hongtai; Xia, Zhaofan

    2016-01-01

    Patient: Male, 32 Final Diagnosis: Thoracic duct chylous fistula Symptoms: Fistula Medication: — Clinical Procedure: A boneless muscle flap transplantatio Specialty: — Objective: Rare disease Background: As patients with thoracic duct injuries often suffer from severe local soft tissue defects, integrated surgical treatment is needed to achieve damage repair and wound closure. However, thoracic duct chylous fistula is rare in burn patients, although it typically involves severe soft tissue damage in the neck or chest. Case Report: A 32-year-old male patient fell after accidentally contacting an electric current (380 V) and knocked over a barrel of sulfuric acid. The sulfuric acid continuously poured onto his left neck and chest, causing combined electrical and sulfuric acid burn injuries to his anterior and posterior torso, and various parts of his limbs (25% of his total body surface area). During treatment, chylous fistula developed in the left clavicular region, which we diagnosed as thoracic duct chylous fistula. We used diet control, intravenous nutritional support, and continuous somatostatin to reduce the chylous fistula output, and hydrophilic silver ion-containing dressings for wound coverage. A boneless muscle flap was used to seal the left clavicular cavity, and, integrated, these led to resolution of the chylous fistula. Conclusions: Patients with severe electric or chemical burns in the neck or chest may be complicated with thoracic duct injuries. Although conservative treatment can control chylous fistula, wound cavity filling using a muscle flap is an effective approach for wound healing. PMID:27725628

  16. Sulfur polymer cement as a low-level waste glass matrix encapsulant

    Energy Technology Data Exchange (ETDEWEB)

    Sliva, P.; Peng, Y.B.; Peeler, D.K. [and others

    1996-01-01

    Sulfur polymer cement (SPC) is being considered as a matrix encapsulant for the Hanford low-level (activity) waste glass. SPC is an elemental sulfur polymer-stabilized thermoplastic that is fluid at 120 {degrees}C to 140{degrees}C. The candidate process would encapsulate the waste glass by mixing the glass cullet with the SPC and casting it into the container. As the primary barrier to groundwater and a key factor in controlling the local environment of the disposal system after it has been compromised, SPC plays a key role in the waste form`s long-term performance assessment. Work in fiscal year 1995 targeted several technical areas of matrix encapsulation involving SPC. A literature review was performed to evaluate potential matrix-encapsulant materials. The dissolution and corrosion behavior of SPC under static conditions was determined as a function of temperature, pH, and sample surface area/solution volume. Preliminary dynamic flow-through testing was performed. SPC formulation and properties were investigated, including controlled crystallization, phase formation, modifying polymer effects on crystallization, and SPC processibility. The interface between SPC and simulated LLW glass was examined. Interfacial chemistry and stability, the effect of water on the glass/SPC interface, and the effect of molten sulfur on the glass surface chemistry were established. Preliminary scoping experiments, involving SPC`s Tc gettering capabilities were performed. Compressive strengths of SPC and SPC/glass composites, both before and after lifetime radiation dose exposure, were determined.

  17. Histological responses of some plant leaves to hydrogen fluoride and sulfur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Adams, D.F.; Solberg, R.A.

    1956-12-01

    Dicotyledonous plants were fumigated with hydrogen fluoride and/or sulfur dioxide. Samples were taken of injured and control leaves, processed microtechnically, and examined microscopically. Histological responses to hydrogen fluoride and sulfur dioxide were indistinguishable. The spongy mesophyll and lower epidermis first collapsed, followed by distortion and chloroplast disruption in the palisade cells. The upper epidermis finally distorted and collapsed. Microscopically injured leaf tissues were selectively stained with safranin. Various postulates are discussed concerning the means and pathways by which a phytotoxic air pollutant may enter the leaf and produce injury therein. The evidence indicates that should fluoride enter a leaf in sub-phytotoxic concentrations, it is transported acropetally. Should phytotoxic levels be reached, visible marginal injury results.

  18. Exploring the core level shift origin of sulfur and thiolates on Pd(111) surfaces.

    Science.gov (United States)

    Salvarezza, Roberto Carlos; Carro, Pilar

    2015-10-01

    Thiol molecules on planar metal surfaces are widely used for building sensing and electronic devices and also as capping agents to protect and to control the size and shape of nanoparticles. In the case of Pd the thiol molecules exhibit a complex behavior because C-S bond scission is possible, resulting in a significant amount of co-adsorbed S. Therefore identification of these species on Pd is a key point for many applications, a task that is usually achieved by XPS. Here we show, from DFT calculations, that the core level shift (CLS) of the S 2p binding energy (BE) of thiol and sulfur on different thiol-Pd(111) surface models strongly depends on the adsorbed or subsurface state of sulfur atoms. Our results reflect the complexity of S 2p BE behavior and contribute to understanding and reanalyzing the experimental data of thiolated Pd surfaces.

  19. Early growth dynamical implications for the steerability of stratospheric solar radiation management via sulfur aerosol particles

    Science.gov (United States)

    Benduhn, François; Schallock, Jennifer; Lawrence, Mark G.

    2016-09-01

    Aerosol growth dynamics may have implications for the steerability of stratospheric solar radiation management via sulfur particles. This paper derives a set of critical initial growth conditions that are analyzed as a function of two key parameters: the initial concentration of the injected sulfuric acid and its dilution rate with the surrounding air. Based upon this analysis, early aerosol growth dynamical regimes may be defined and classified in terms of their likelihood to serve as candidates for the controlled generation of a radiatively effective aerosol. Our results indicate that the regime that fulfills all critical conditions would require that airplane turbines be used to provide sufficient turbulence. The regime's parameter space is narrow and related to steep gradients, thus pointing to potential fine tuning requirements. More research, development, and testing would be required to refine our findings and determine their global-scale implications.

  20. The role of sulfur in osmoregulation and salinity tolerance in cyanobacteria, algae, and plants

    Science.gov (United States)

    Yopp, J. H.

    1985-01-01

    Organosulfur compounds are involved in osmoregulation and salinity tolerance in some cyanobacteria and photosynthetic eukaryotes. Glycinebetaine, the osmolyte of the halotolerant cyanobacterium, Aphanothece halophytica, requires the sulfonium compound. S-adenosyl-methionine (SAM) for its synthesis. Glutamate is the nitrogen source, SAM is the methyl carbon and serine the carbon backbone source of this unique osmolyte. Inhibitor studies suggest that photorespiration interacts with sulfur metabolism to control betaine synthesis in cyanobacteria. The limiting factor for SAM synthesis is formate from photorespiration. SAM is, in turn, the methyl donor for betaine synthesis from serine. The nitrogen component of serine is from glutamate. Betaine synthesis is hypothesized to be regulated via potassium. The biosynthesis of dimethyl-B-propiothetin (DMPT, which is the same as beta-dimethyl sulfonioprpionate) and diacylsulfoquinovosylglycerol were elucidated as having their roles in osmoregulation and salinity tolerance. The relation between these sulfolipids and the sulfur cycle was discussed.