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1

Sulfur compounds in coal  

NASA Technical Reports Server (NTRS)

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

Attar, A.; Corcoran, W. H.

1977-01-01

2

Sulfur  

Microsoft Academic Search

Sulfur, an element in wide industrial use, currently is mined or recovered in the U.S. from elemental sulfur deposits associated with evaporites, from sulfur-bearing petroleum and natural gas, and from sulfide ores. The element also occurs as a constituent in bedded gypsum and anhydrite, coal, tar sands, and oil shale, as well as in volcanic deposits, none of which is

Bodenlos

1973-01-01

3

Potential Antimalarial Organic Sulfur Compounds.  

National Technical Information Service (NTIS)

In an attempt to develop useful antimalarial medicinal agents, a series of twenty two organic sulfur compounds were synthesized which were analogous in structure to 4,4'-diaminodiphenyl sulfone an effective antimalarial. Fifteen of these compounds were N-...

K. K. Andersen J. Bhattacharyya S. K. Mukhopadhyay

1969-01-01

4

Sulfur Compounds in Comets. (Abstract Only)  

National Technical Information Service (NTIS)

Cometary atmospheres exhibit abundant sulfur and sulfur compounds, which are absent in planetary atmospheres. Sulfur compounds were also detected in interstellar media, including SO, SO2, CS, etc., but excluding S2 which was identified only in IRAS-Araki-...

S. Kim M. Ahearn

1989-01-01

5

Refractory sulfur compounds in gas oils  

Microsoft Academic Search

Five heavy straight run gas oils from different crude oils were analyzed by sulfur and carbon sensitive high resolution capillary gas chromatography. Gas oils also were hydrotreated in a fixed bed gas-phase reactor. Model substances, representing refractory sulfur compounds, were converted in a CSTR slurry reactor. Sulfur concentration profiles of the original oils were calculated and showed the sulfur concentration

H Schulz; W Böhringer; F Ousmanov; P Waller

1999-01-01

6

Thiophenic Sulfur Compounds Released During Coal Pyrolysis.  

PubMed

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

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

2013-06-01

7

Thiophenic Sulfur Compounds Released During Coal Pyrolysis  

PubMed Central

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.

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

2013-01-01

8

C 1 -cycle of sulfur compounds  

Microsoft Academic Search

C1 organic sulfides are part of many ecosystems and play an important role in the global sulfur budget and climate regulation. At this point, fluxes and conversions of these compounds are only superficially understood. Understanding of the regulating mechanisms will be necessary to quantify the role of these compounds in the global sulfur budget at their climatic role. In this

Jolyn M. M. Zwart; J. Gijs Kuenen

1992-01-01

9

Ambient Air Monitoring for Sulfur Compounds  

ERIC Educational Resources Information Center

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)

Forrest, Joseph; Newman, Leonard

1973-01-01

10

Heterogeneous photocatalytic reactions of sulfur aromatic compounds.  

PubMed

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

Samokhvalov, Alexander

2011-11-18

11

Sulfur-containing compounds from Clinacanthus siamensis.  

PubMed

Two new sulfur-containing compounds, trans-3-methylsulfonyl-2-propenol (1) and trans-3-methylsulfinyl-2-propenol (2) were isolated together with trans-3-methylthioacrylamide (3), entadamide A (4) and entadamide C (5) from the leaves of Clinacanthus siamensis. The structures were established on the basis of the spectroscopic data. The compounds were tested for antimalarial and antimycobacterial activity. PMID:14646322

Tuntiwachwuttikul, Pittaya; Pootaeng-on, Yupa; Pansa, Pootchana; Srisanpang, Thongchai; Taylor, Walter Charles

2003-12-01

12

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

NASA Astrophysics Data System (ADS)

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

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

2007-02-01

13

Analyze trace sulfur compounds in hydrocarbon gas streams  

Microsoft Academic Search

Measuring trace sulfur compounds in fuel gases has been an industry requirement for many years and now plays a role in a variety of processing areas. One such area involves controlling hydrogen sulfide (HâS) and other sulfur compounds in natural gas and fuel gas to prevent corrosion of pipelines and other equipment. Further, using sulfur compounds as odorants makes natural

M. Anderson; R. C. Dimmer

1997-01-01

14

Two stage sorption of sulfur compounds  

DOEpatents

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

Moore, William E. (Manassas, VA)

1992-01-01

15

A Manual Method for Measurement of Reduced Sulfur Compounds  

Microsoft Academic Search

A manual method for measuring reduced sulfur compounds in kraft pulp mill and sulfur recovery plant emissions was evaluated. The method involves removing SO2 from the gas stream (if present) with a citric acid-potassium citrate buffer that passes reduced sulfur compounds; thermal oxidation of all reduced sulfur compounds to SO2; collection of the SO2 in H2O2; and a titrimetric analysis

John H. Margeson; Joseph E. Knoll; M. Rodney Midgett; Bruce B. Ferguson; Philip J. Schworer

1985-01-01

16

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

PubMed

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. PMID:12541959

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

2002-05-01

17

MANUAL METHOD FOR MEASUREMENT OF REDUCED SULFUR COMPOUNDS  

EPA Science Inventory

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

18

The effect of heavy aromatic sulfur compounds on sulfur in cracked naphtha  

Microsoft Academic Search

The scope of the present study was to elucidate the effect of heavy sulfur compounds, commonly found in the gas oils, on the percentage of sulfur in gasoline range during the Fluid Catalytic Cracking (FCC) process. Five model sulfur compounds commonly found in the gas oils were studied: benzothiophene, 2-methyl-benzothiophene, 3-decyl-thiophene, dibenzothiophene and 4,6-dimethyl-dibenzothiophene. In order to maintain a realistic

J. A. Valla; E. Mouriki; A. A. Lappas; I. A. Vasalos

2007-01-01

19

Modulation of volatile sulfur compounds by wine yeast  

Microsoft Academic Search

Sulfur compounds in wine can be a ‘double-edged sword’. On the one hand, certain sulfur-containing volatile compounds such\\u000a as hydrogen sulfide, imparting a rotten egg-like aroma, can have a negative impact on the perceived quality of the wine, and\\u000a on the other hand, some sulfur compounds such as 3-mercaptohexanol, imparting fruitiness, can have a positive impact on wine\\u000a flavor and

J. H. Swiegers; I. S. Pretorius

2007-01-01

20

Process for removing sulfur and sulfur compounds from the effluent of industrial processes  

Microsoft Academic Search

Sulfur dioxide in the stack gas from an industrial process is converted to elemental sulfur in a claus reactor at low temperature to produce sulfur fume. The sulfur is condensed by direct heat transfer with a continuously flowing countercurrent recirculating catalyst and a substantially sulfur dioxide-free gas is discharged. Catalyst and condensed sulfur are fed into the top of a

Sims

1981-01-01

21

DATABASE FOR ORGANIC SULFUR COMPOUNDS USING GC-SCD METHOD. DETERMINATION OF SULFUR CONTAINING COMPOUNDS IN STRAIGHT RUN GAS OBLS (SRGO)  

Microsoft Academic Search

Sulfur standards were studied on a high resolution gas chromatograph (GC) “HP 5890 series II plus ”. Retention times were determined for each individual compound, A sample of straight run gas-oil (SRGO) was analyzed by coulomax method for total sulfur and by GC equipped with sulfur chemiluminescence detector (SCD) for individual sulfur identification, A database for about 165 sulfur compounds

M. K. Andari; H. Behbehani; H. Qabazard

1996-01-01

22

Treatment of Waste Gases Contaminated with Odorous Sulfur Compounds  

Microsoft Academic Search

Due to their very low odor threshold value (ppbv range), high toxicity, and potential corrosive effect, the presence of volatile sulfur compounds in waste gases deserves special attention. These sulfur compounds mainly include hydrogen sulfide, dimethyl sulfide, dimethyl disulfide, meth-anethiol, carbon disulfide, and carbonyl sulfide. Contrary to natural emissions, anthropogenic emissions may contribute to local concentrations, strongly exceeding the odor

E. Smet; P. Lens; H. Van Langenhove

1998-01-01

23

Oxidative metabolism of inorganic sulfur compounds by bacteria.  

PubMed

The history of the elucidation of the microbiology and biochemistry of the oxidation of inorganic sulfur compounds in chemolithotrophic bacteria is briefly reviewed, and the contribution of Martinus Beijerinck to the study of sulfur-oxidizing bacteria highlighted. Recent developments in the biochemistry, enzymology and molecular biology of sulfur oxidation in obligately and facultatively lithotrophic bacteria are summarized, and the existence of at least two major pathways of thiosulfate (sulfur and sulfide) oxidation confirmed. These are identified as the 'Paracoccus sulfur oxidation' (or PSO) pathway and the 'S4intermediate' (or S4I) pathway respectively. The former occurs in organisms such as Paracoccus (Thiobacillus) versutus and P. denitrificans, and possibly in Thiobacillus novellus and Xanthobacter spp. The latter pathway is characteristic of the obligate chemolithotrophs (e.g. Thiobacillus tepidarius, T. neapolitanus, T. ferrooxidans, T. thiooxidans) and facultative species such as T. acidophilus and T. aquaesulis, all of which can produce or oxidize tetrathionate when grown on thiosulfate. The central problem, as yet incompletely resolved in all cases, is the enzymology of the conversion of sulfane-sulfur (as in the outer [S-] atom of thiosulfate [-S-SO3-]), or sulfur itself, to sulfate, and whether sulfite is involved as a free intermediate in this process in all, or only some, cases. The study of inorganic sulfur compound oxidation for energetic purposes in bacteria (i.e. chemolithotrophy and sulfur photolithotrophy) poses challenges for comparative biochemistry. It also provides evidence of convergent evolution among diverse bacterial groups to achieve the end of energy-yielding sulfur compound oxidation (to drive autotrophic growth on carbon dioxide) but using a variety of enzymological systems, which share some common features. Some new data are presented on the oxidation of 35S-thiosulfate, and on the effect of other anions (selenate, molybdate, tungstate, chromate, vanadate) on sulfur compound oxidation, including observations which relate to the roles of polythionates and elemental sulfur as intermediates. PMID:9049021

Kelly, D P; Shergill, J K; Lu, W P; Wood, A P

1997-02-01

24

Characterization of High-Pressure Iron-Sulfur Compounds  

NASA Astrophysics Data System (ADS)

Iron and sulfur are considered to be the major elements in the Martian core. Recent high-pressure experiments revealed that at least three new iron-sulfur compounds, Fe3S2, Fe2S, and Fe3S, were formed at high pressures. In this study, we provide new information on their structure and stability.

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

2002-03-01

25

Method for removal of sulfur compounds from a gas stream  

SciTech Connect

This invention relates to a process for the removal of sulfur compounds from a gas stream. More specifically, this invention relates to an improvement in the iron oxide method of sulfur removal from a gas stream through the use of hydrogen peroxide.

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

1982-01-19

26

Method for removal of sulfur compounds from a gas stream  

Microsoft Academic Search

This invention relates to a process for the removal of sulfur compounds from a gas stream. More specifically, this invention relates to an improvement in the iron oxide method of sulfur removal from a gas stream through the use of hydrogen peroxide.

K. J. Frech; J. J. Tazuma

1982-01-01

27

Method for removal of sulfur compounds from a gas  

SciTech Connect

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

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

1981-08-11

28

Method for removal of sulfur compounds from a gas  

Microsoft Academic Search

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

K. J. Frech; J. J. Tazuma

1981-01-01

29

Hydrodesulfurization reactivities of various sulfur compounds in vacuum gas oil  

Microsoft Academic Search

The hydrodesulfurization (HDS) of a vacuum gas oil (VGO) was performed at 360 C (6.9 MPa) over a commercial NiMo catalyst to examine the HDS reactivities of various sulfur compounds which exist in the VGO by means of quantitative pseudo-first-order kinetic analysis. Four representative types of aromatic-skeleton sulfur compounds were observed in the VGO: alkylbenzothiophenes (BTs), alkyldibenzothiophenes (DBTs), alkylphenanthro[4,5-b,c,d]thiophenes (PTs),

Xiaoliang Ma; Kinya Sakanishi; Isao Mochida

1996-01-01

30

Sulfuric odorous compounds emitted from pig-feeding operations  

Microsoft Academic Search

The objective of the study was to quantify the concentration and emission levels of sulfuric odorous compounds emitted from pig-feeding operations. Five types of pig-housing rooms were studied: gestation, farrowing, nursery, growing and fattening rooms. The concentration range of sulfuric odorous compounds in these pig-housing rooms were 30–200ppb for hydrogen sulfide (H2S), 2.5–20ppb for methyl mercaptan (CH3SH), 1.5–12ppb for dimethyl

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

2007-01-01

31

Microbial removal of organic sulfur from coal (bacterial degradation of sulfur-containing heterocyclic compounds)  

SciTech Connect

The presence of substantial levels of sulfur in coal is a major source of air pollution, and considerable efforts are being made to devise a cost-effective way of removing the sulfur. One method is to mutate a laboratory species, Escherichia coli, an organism which is genetically well-understood and whose pathways for the metabolism of sulfur-containing amino acids have been extensively investigated. Such thiophene degraders can be genetically analyzed and the genes involved can be cloned in order to amplify their products. A second approach is the development of naturally occurring bacteria capable of thiophene desulfurization. Characterization of the degradation of model compounds, enhancement of the desulfurization potential of the isolated strains via mutagenesis, and studies with crushed coal will comprise the approach used in this study. The screening of soil isolates for the potential to desulfurize thiophenic and other sources of organic sulfur will identify the best strains for the microbial removal of organic sulfur from coal. Ultimately, the genes responsible for thiophene degradation by the isolated strains will be transferred to an E. coli strain, creating a single organism capable of degrading a broad spectrum of thiophene compounds. 24 refs., 3 figs., 2 tabs.

Klubek, B.

1990-03-01

32

Organic sulfur compounds in crude oils of West Kazakhstan  

Microsoft Academic Search

The group composition of these compounds in the crude oils and cuts was determined by methods that have been used previously [1-4]. The data are listed in Table 1. The oils from the Tortai, Kultuk, and Zhilankabak fields are classed as low-sulfur(total sulfur contents 0.22%, 0.44%, and 0.47%, respectively). The yield of light cuts below 200~C varies from 7.7%to 30.4%,

V. V. Ryzhenko; A. V. Kotova; N. S. Buyanova; N. K. Nadirov

1982-01-01

33

Phase Equilibria for Separation of Organic Sulfur Compounds for Cleaner Fuels  

Microsoft Academic Search

The infinite dilution activity coefficients (??) of sulfur compounds in hydrocarbons are very important in the reliable design of sulfur removal processes producing cleaner gasoline. We determined 23 ?? of sulfur compounds from vapor-liquid equilibrium (VLE) binary systems measurements with recirculation still and 7 infinite dilution activity coefficients of systems containing different sulfur compounds in selected hydrocarbons with comparative ebulliometers.

Erlin Sapei; Piia Haimi; Anna Zaytseva; Petri Uusi-Kyyny; Kari I. Keskinen; Juhani Aittamaa

34

Improving rubber concrete by waste organic sulfur compounds.  

PubMed

In this study, the use of crumb tyres as additives to concrete was investigated. For some time, researchers have been studying the physical properties of concrete to determine why the inclusion of rubber particles causes the concrete to degrade. Several methods have been developed to improve the bonding between rubber particles and cement hydration products (C-S-H) with the hope of creating a product with an improvement in mechanical strength. In this study, the crumb tyres were treated with waste organic sulfur compounds from a petroleum refining factory in order to modify their surface properties. Organic sulfur compounds with amphiphilic properties can enhance the hydrophilic properties of the rubber and increase the intermolecular interaction forces between rubber and C-S-H. In the present study, a colloid probe of C-S-H was prepared to measure these intermolecular interaction forces by utilizing an atomic force microscope. Experimental results showed that rubber particles treated with waste organic sulfur compounds became more hydrophilic. In addition, the intermolecular interaction forces increased with the adsorption of waste organic sulfur compounds on the surface of the rubber particles. The compressive, tensile and flexural strengths of concrete samples that included rubber particles treated with organic sulfur compound also increased significantly. PMID:19710121

Chou, Liang-Hisng; Lin, Chun-Nan; Lu, Chun-Ku; Lee, Cheng-Haw; Lee, Maw-Tien

2010-01-01

35

Fractionation and characterization of sulfur compounds in petroleum distillates  

SciTech Connect

In this paper a procedure for the fractionation and the characterization of sulfur containing compounds in petroleum distillated is described. The method is based on a chromatographic separation using alumna columns coated with silver nitrate (Ligard Exchange Chromatography) which permits the separation of molecules containing aromatic sulfur (thiophenic compounds) from the sulfides. The subsequent gc analysis using selective atomic emission detector allows the quantification of the two types of compound s in each fraction. The results of the application of this procedure on an Egyptian gas-oil from Belaym crude are reported.

Del Bianco, A.; Anelli, M. (Eniricerche S.p.A., Via Maritano 26, 20097 S. Donato, Milano (IT)); Riva, A. (Agip S.p.A., Via Maritano 26, 20097 Milano (IT))

1992-01-01

36

Performance evaluation of HDS catalysts by distribution of sulfur compounds in naphtha  

Microsoft Academic Search

This paper presents results of pilot plant evaluation of two commercial hydrodesulfurization (HDS) catalysts and demonstrates the use of trace sulfur analysis and distribution of sulfur compounds for reliable and better catalyst evaluation. Straight-run naphtha (SRN) and a blend of SRN and hydrocracked naphtha containing 897 and 534 ppm sulfur respectively were analysed for sulfur compound distribution by gas chromatography

Jamal A. Anabtawi; Khurshid Alam; Mohammed A. Ali; Syed A. Ali; Mohammed A. B. Siddiqui

1995-01-01

37

A Systematic Presentation of Organic Phosphorus and Sulfur Compounds.  

ERIC Educational Resources Information Center

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

Hendrickson, James B.

1985-01-01

38

Sulfur-binding in recent environments: II. Speciation of sulfur and iron and implications for the occurrence of organo-sulfur compounds  

NASA Astrophysics Data System (ADS)

Speciation of iron and sulfur species was determined for two recent sediments (La Trinitat and Lake Cisó) which were deposited in environments with a high biological productivity and sulfate-reducing activity. In sediments from calcite ponds of La Trinitat an excess of reactive iron species (iron monosulfides, iron hydroxides) results in a depletion of reactive sulfur which is accompanied by a virtual absence of organo-sulfur compounds, both in low (LMW) and high molecular-weight (HMW) fractions. Small amounts of phytanyl and highly branched isoprenoid (HBI) thiophenes in the extract demonstrate that these molecules exhibit a higher reactivity towards reduced sulfur species as compared to detrital iron. Euxinic sediments from Lake Cisó are characterised by an excess of reduced sulfur species which can rapidly trap reactive iron. High concentrations of H 2S results in the formation of organo-sulfur compounds which were encountered in both LMW and HMW fractions. The major part of the organic sulfur is bound to the carbohydrate portion of woody tissues, whose presence was revealed by a specific alkylthiophene distribution in the flash pyrolysate and by Li/EtNH 2 desulfurisation of the kerogen which resulted in the solubilisation of the sulfur-enriched hemicellulose fraction. Relatively high amounts of sulfurised C 25 HBI compounds in the sediment extract of Lake Cisó reflect the incorporation of sulfur into algal derived organic matter upon early diagenesis. The combined approach of the speciation of iron and sulfur species and the molecular analysis of sedimentary fractions demonstrates that abiotic sulfur binding to organic matter occurs at the earliest stages of diagenesis under specific depositional conditions (anoxic, stratified water column) in which an excess of reduced sulfur species relative to the amount of reactive iron is a controlling factor.

Hartgers, Walter A.; Lòpez, Jordi F.; Sinninghe Damsté, Jaap S.; Reiss, Christine; Maxwell, James R.; Grimalt, Joan O.

1997-11-01

39

Antioxidant combinations of molybdenum complexes and organic sulfur compounds for lubricating oils  

SciTech Connect

An antioxidant additive combination for lubricating oils is prepared by combining (a) a sulfur containing molybdenum compound prepared by reacting an ammonium tetrathiomolybdate, and a basic nitrogen compound, with (b) an organic sulfur compound.

deVries, L.; King, J.M.

1983-09-06

40

Uses of lunar sulfur  

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

41

Photosynthetic bioconversion sulfur removal  

SciTech Connect

A photosynthetic bioconversion process is described for removal of sulfur compounds from a gas stream comprising carbon oxide and reductive sulfur compounds. The process comprises: contacting the gas stream consisting of carbon oxide compounds and reductive sulfur compounds with an active culture of photosynthetic bacteria capable of utilizing the reductive sulfur compound as its sole source of reducing electrons and the carbon oxides as its sole source of carbon for growth under substantially anaerobic conditions with electromagnetic radiation. The reductive sulfur compound provides the sole source of reducing electrons and the carbon oxides provide the sole source of carbon for growth and cultivating the bacteria to form elemental sulfur and organic carbon compounds.

Cork, D.J.

1987-05-19

42

Sulfur compounds in oils from the Western Canada Tar Belt  

Microsoft Academic Search

Sulfur compounds in the gas oil fractions from two bitumens (Athabasca oil sand and Cold Lake deposit), a heavy oil (Lloydminster) from Cretaceous reservoirs along the western Canada sedimentary basin, and a Cretaceous oil from a deep reservoir that may be mature (Medicine River) are investigated. The gas oil distillates were separated to concentrates of different hydrocarbon types on a

D. M. Clugston; A. E. George; D. S. Montgomery; G. T. Smiley; H. Sawatzky

1976-01-01

43

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

Microsoft Academic Search

A portable real time instrument for detecting concentrations in the part per billion range of reduced sulfur compounds in a sample gas. Ozonized air or oxygen and reduced sulfur compounds in a sample gas stream react to produce chemiluminescence in a reaction chamber and the emitted light is filtered and observed by a photomultiplier to detect reduced sulfur compounds. Selective

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

1983-01-01

44

Wet scrubber process for removing total reduced sulfur compounds from industrial gases  

Microsoft Academic Search

This patent describes a process for the removal of total reduced sulfur compounds and recovery of non-magnetic entrained particulates from an industrial gas. It comprises: scrubbing the industrial gas with an aqueous absorbent slurry containing activated manganese dioxide absorbent particles in a reaction zone to effect oxidation of the total reduced sulfur compounds and recovery of total reduced sulfur compound

Iannicelli

1990-01-01

45

[Determination of sulfur compounds in fluid catalytic cracking gasoline by gas chromatography with a sulfur chemiluminescence detector].  

PubMed

A method for the separation and determination of sulfur compounds in fluid catalytic cracking gasoline (FCC gasoline) by gas chromatography with a sulfur chemiluminescence detector (GC-SCD) was established. Fifty eight sulfur compounds including mercaptan, sulfide, disulfide, thiophene, alkyl thiophenes, benzothiophene and alkyl benzothiophenes were identified based on their retention indexes and the data obtained from gas chromatography with an atomic emission detector (GC-AED). The effects of flow rate of carrier gas and oven temperature were discussed. Detection reproducibilities of main sulfur compounds (thiophene, n-butyl mercaptan, 2-methylthiophene, 3-methylthiophene, 2,4-dimethylthiophene) in FCC gasoline were satisfactory (RSDs were no more than 5.0%) and detection limit for sulfur was 0.1 mg/L. Using thiophene and benzothiophene as testing samples, it was determined that response factor was independent of the molecular structure of sulfur compounds. The linear range was 0.5-800.0 mg/L sulfur with a correlation coefficient of 0.999. PMID:15712900

Yang, Yongtan; Wang, Zheng; Zong, Baoning; Yang, Haiying

2004-05-01

46

Corrosion of stainless steels in acid solutions with organic sulfur-containing compounds  

Microsoft Academic Search

The influence of the organic sulfur-containing compounds on the corrosion of ferrite and austenitic stainless steels in sulfuric acid was studied. The results showed that the anodic dissolution and self-corrosion of stainless steels were remarkably accelerated in solutions with a low amount of the organic sulfur-containing compounds (0.02 mmol\\/dm3). With an increase of the organic sulfur-containing compound concentration, more and

X. L Cheng; H. Y Ma; S. H Chen; R Yu; X Chen; Z. M Yao

1998-01-01

47

Chemiluminescent detection of reduced sulfur compounds with ozone  

SciTech Connect

With the aim of developing a simple, sensitive, selective real-time method for measurement of reduced sulfur gases, we have investigated the chemiluminescent detection of H/sub 2/S, DMS, and other reduced sulfur compounds by their oxidation with ozone. The observation of chemiluminescence in the 300 to 400 nm wavelength region resulting from the gas-phase reaction of O/sub 3/ with H/sub 2/S, DMS, and methyl mercaptan (C-H/sub 3/SH) has been identified as electronically excited SO/sub 2/. The homogeneous gas-phase reaction of ozone with hydrogen sulfide has been reported to be slow in studies at low pressures and the oxidation mechanism is apparently complex. A reaction order for H/sub 2/S from 0.5 to 2 has been observed, and a heterogeneous reaction pathway has been proposed as a possible explanation of the data. Reported here are results of a preliminary investigation of the ozone-reduced sulfur chemiluminescence, which also imply a complex reaction mechanism (possibly both homogeneous and heterogeneous) but indicate that ozone chemiluminescence may be an extremely useful tool for the detection of H/sub 2/S, DMS, and other reduced sulfur species in the ambient atmosphere and in industrial applications.

Kelly, T.J.; Gaffney, J.S.; Phillips, M.F.; Tanner, R.L.

1983-01-01

48

Characterization of malodorous sulfur compounds in landfill gas  

Microsoft Academic Search

In order to analyze the composition of landfill gas (LFG) with respect to malodorous components, the concentrations of several reduced sulfur compounds (RSC: hydrogen sulfide (H2S); methyl mercaptan (CH3SH); dimethyl sulfide ((CH3)2S); carbon disulfide (CS2); and dimethyl disulfide ((CH3)2S2)) were determined from four municipal landfill sites—initialed W, B, H, and N—in Korea. The S gas concentrations measured in these landfill

Ki-Hyun Kim; YJ Choi; EC Jeon; Young Sunwoo

2005-01-01

49

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

NASA Astrophysics Data System (ADS)

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

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

2013-11-01

50

Structure of sulfur compounds in medium-viscosity oils from Ust'Balyk crude  

Microsoft Academic Search

Adsorption of the oil on silica gel [2] was used to obtain sulfur\\/aromatic and sulfur concentrates, which were desorbe~ from the silica gel in the indicated order. The two types of concentrates differed in quantity and nature of the sulfur present. 0nly thiophene compounds were present in the sulfur\\/aromatic concentrates, and the concentration of these compounds was at most 40%.

N. N. Kucheryavaya; Z. I. Rozanova; A. G. Siryuk; F. G. Sidlyaronok; E. S. Brodskii

1976-01-01

51

Emission of Volatile Sulfur Compounds from Spruce Trees 1  

PubMed Central

Spruce (Picea Abies L.) trees from the same clone were supplied with different, but low, amounts of plant available sulfate in the soil (9.7-18.1 milligrams per 100 grams of soil). Branches attached to the trees were enclosed in a dynamic gas exchange cuvette and analyzed for the emission of volatile sulfur compounds. Independent of the sulfate supply in the soil, H2S was the predominant reduced sulfur compound continuously emitted from the branches with high rates during the day and low rates in the night. In the light, as well as in the dark, the rates of H2S emission increased exponentially with increasing water vapor flux from the needles. Approximately 1 nanomole of H2S was found to be emitted per mole of water. When stomata were closed completely, only minute emission of H2S was observed. Apparently, H2S emission from the needles is highly dependent on stromatal aperture, and permeation through the cuticle is negligible. In several experiments, small amounts of dimethylsulfide and carbonylsulfide were also detected in a portion of the samples. However, SO2 was the only sulfur compound consistently emitted from branches of spruce trees in addition to H2S. Emission of SO2 mainly proceeded via an outburst starting before the beginning of the light period. The total amount of SO2 emitted from the needles during this outburst was correlated with the plant available sulfate in the soil. The diurnal changes in sulfur metabolism that may result in an outburst of SO2 are discussed.

Rennenberg, Heinz; Huber, Beate; Schroder, Peter; Stahl, Klaus; Haunold, Werner; Georgii, Hans-Walter; Slovik, Stefan; Pfanz, Hardy

1990-01-01

52

The role of labile sulfur compounds in thermochemical sulfate reduction  

NASA Astrophysics Data System (ADS)

The reduction of sulfate to sulfide coupled with the oxidation of hydrocarbons to carbon dioxide, commonly referred to as thermochemical sulfate reduction (TSR), is an important abiotic alteration process that most commonly occurs in hot carbonate petroleum reservoirs. In the present study we focus on the role that organic labile sulfur compounds play in increasing the rate of TSR. A series of gold-tube hydrous pyrolysis experiments were conducted with n-octane and CaSO 4 in the presence of reduced sulfur (e.g. H 2S, S°, organic S) at temperatures of 330 and 356 °C under a constant confining pressure. The in-situ pH was buffered to 3.5 (˜6.3 at room temperature) with talc and silica. For comparison, three types of oil with different total S and labile S contents were reacted under similar conditions. The results show that the initial presence of organic or inorganic sulfur compounds increases the rate of TSR. However, organic sulfur compounds, such as 1-pentanethiol or diethyldisulfide, were significantly more effective in increasing the rate of TSR than H 2S or elemental sulfur (on a mole S basis). The increase in rate is achieved at relatively low concentrations of 1-pentanethiol, less than 1 wt% of the total n-octane, which is comparable to the concentration of organic S that is common in many oils (˜0.3 wt%). We examined several potential reaction mechanisms to explain the observed reactivity of organic LSC. First, the release of H 2S from the thermal degradation of thiols was discounted as an important mechanism due to the significantly greater reactivity of thiol compared to an equivalent amount of H 2S. Second, we considered the generation of olefines in association with the elimination of H 2S during thermal degradation of thiols because olefines are much more reactive than n-alkanes during TSR. In our experiments, olefines increased the rate of TSR, but were less effective than 1-pentanethiol and other organic LSC. Third, the thermal decomposition of organic LSC creates free-radicals that in turn might initiate a radical chain-reaction that creates more reactive species. Experiments involving radical initiators, such as diethyldisulfide and benzyldisulfide, did not show an increase in reactivity compared to 1-pentanethiol. Therefore, we conclude that none of these can sufficiently explain our observations of the initial stages of TSR; they may, however, be important in the later stages. In order to gain greater insight into the potential mechanism for the observed reactivity of these organic sulfur compounds during TSR, we applied density functional theory-based molecular modeling techniques to our system. The results of these calculations indicate that 1-pentanethiol or its thermal degradation products may directly react with sulfate and reduce the activation energy required to rupture the first S-O bond through the formation of a sulfate ester. This study demonstrates the importance of labile sulfur compounds in reducing the onset timing and temperature of TSR. It is therefore essential that labile sulfur concentrations are taken into consideration when trying to make accurate predictions of TSR kinetics and the potential for H 2S accumulation in petroleum reservoirs.

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

2008-06-01

53

The role of labile sulfur compounds in thermochemical sulfate reduction  

USGS Publications Warehouse

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

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

2008-01-01

54

Nonflame, source-induced sulfur fluorescence detector for sulfur-containing compounds  

Microsoft Academic Search

Results of some preliminary investigations of the fluorescence spectra of Sâ and the non-flame production of Sâ from sulfur-containing molecules are reported. Passage of the gas to be analyzed through a catalyst-oven containing a plug of NiOâ\\/AlâOâ catalyst containing 10 wt% NiOâ and heated to 400°C resulted in conversion of HâS to Sâ and elemental sulfur. The Sâ was detected

D. R. Gage; S. O. Farwell

1980-01-01

55

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

PubMed Central

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

Kargi, Fikret; Robinson, James M.

1982-01-01

56

Determination of odorous sulfur compounds in air by Tenax GR preconcentration and capillary gas chromatography in combination with flameless sulfur chemiluminescence detection  

Microsoft Academic Search

A liner of PTV injector packed with the solid adsorbent Tenax GR was used to enrich ambient levels of volatile sulfur compounds, then the sulfur gases were thermally released according to programmed temperature from Tenax GR trap and re?collected in a column cooled with liquid nitrogen. The sulfur compounds were revolatilized and directly transferred to the system of capillary?column gas

2000-01-01

57

Removal of sulfur compounds from combustion product exhaust  

DOEpatents

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

Cheng, Dah Y. (Palo Alto, CA)

1982-01-01

58

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

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

59

Removal of sulfur compounds in fluidized bed carbonaceous solids gasification  

Microsoft Academic Search

This patent describes a process for gasifying sulfur containing carbonaceous feed solids in a single bed maintained fluidized by fluidizing gas introduced through a perforated sloping bed support grid within a single gasification reactor having a density\\/size selective solids withdrawal conduit at a base portion of the bed with upflowing withdrawal gas. It comprises: introducing sulfur containing carbonaceous feed solids

1989-01-01

60

A spectroscopic identification of the products formed in the gas-phase reaction of OH with the atmospheric sulfur compounds: CHâSH, CHâSSCHâ and SOâ  

Microsoft Academic Search

The mechanism for the conversion of naturally occurring atmospheric sulfur compounds to sulfur dioxide is not yet established. The sulfur dioxide produced during degradation of sulfur compounds can undergo further chemical and\\/or physical interactions to form sulfuric acid, which is one of the components of acid rain. A number of sulfur compounds have been detected in the atmosphere; COS (carbonyl

S. C. Bhatia; J. H. Jr. Hall

1986-01-01

61

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

DOEpatents

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

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

1983-06-01

62

Microbial cycling of volatile organic sulfur compounds in anoxic environments.  

PubMed

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

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

2002-01-01

63

Hydrodesulfurization reactivities of various sulfur compounds in diesel fuel  

SciTech Connect

The hydrodesulfurization (HDS) of a diesel oil was carried out in a batch autoclave reactor over the temperature range 280--420 C for 0--90 min under a total pressure of 2.9 MPa, using CoMo and NiMo catalysts in both one and two stages. The HDS reactivities of benzothiophenes, dibenzothiophenes (DBTs), and their alkylated homologes existing in the diesel fuel were examined in detail by means of respective quantitative analyses. The sulfur compounds can be classified into four groups according to their HDS reactivities which were described by their pseudo-first-order rate constants. DBTs carrying two alkyl substituents at the 4- and 6-positions, respectively, were the most resistant to desulfurization. H[sub 2]S produced from reactive sulfur compounds in the early stage of the reaction is one of the main inhibitors for HDS of the unreactive species. A second stage using fresh hydrogen solved this inhibition problem, with NiMo achieving deeper desulfurization.

Ma, X.; Sakanishi, Kinya; Mochida, Isao (Kyushu Univ., Kasuga, Fukuoka (Japan). Inst. of Advanced Material Study)

1994-02-01

64

The interpretation of sulfur K-edge XANES spectra: a case study on thiophenic and aliphatic sulfur compounds.  

PubMed

Sulfur K-edge XANES has been measured for three sulfur model compounds, dibenzothiophene, dibenzothiophene sulfone, and aliphatic sulfur (DL-methionine). The spectra have been simulated with Density Functional Theory (DFT) by using a number of methods, including the half-core-hole approximation. Dipole transition elements were calculated and the transitions were convoluted with linearly increasing Gaussian functions in the first 20 eV of the near-edge region. In the case of dibenzothiophene, relaxation of the first excited states in the presence of the core-hole gave a further improvement. The theoretical results reproduce well the features of the spectra and give insight in the relation between geometric structure and molecular orbitals. Though DL-methionine and dibenzothiophene show a similar sharp rise of the white line, their molecular levels are quite different, pointing out the difficulties in finding useful "fingerprints" in the spectra for specific compounds. PMID:19296706

Mijovilovich, A; Pettersson, L G M; Mangold, S; Janousch, M; Susini, J; Salome, M; de Groot, F M F; Weckhuysen, B M

2009-03-26

65

Determination of sulfur-containing compounds in diesel oils by comprehensive two-dimensional gas chromatography with a sulfur chemiluminescence detector.  

PubMed

This article reports an analytical method for separating, identifying and quantitating sulfur-containing compounds and their groups in diesel oils (170-400 degrees C) using comprehensive two-dimensional gas chromatography coupled with a sulfur chemiluminescence detector. The identification of target compounds and their groups was based on standard substances, the group separation feature and tile-effect of comprehensive two-dimensional gas chromatography. The quantitative analysis on major sulfur compounds and total sulfur was carried out based on the linear response of sulfur chemiluminescence detector and the internal standards method. The results of total sulfur determination in the samples were compared with those from ASTM D 4294 standard method, the R.S.D. percentage were <6.02%, correctness of this method can meet the industrial requirement. To the end, the method developed was used to investigate the sulfur-containing compounds in different diesel oils, the result shows that the distribution of sulfur-containing compounds in diesel oils from different process units are apparently different. The sulfur compounds in fluid catalytic cracking (FCC), residuum fluid catalytic cracking (RFCC) diesel oils mainly exist in the form of alkyl-substituted dibenzothiophenes that add up to about 40-50% of the total sulfur, while this number is only 6-8 and 20-28% in visbreaking (VB) and delayed-coking (DC) diesel oils, respectively. PMID:14650608

Hua, Ruixiang; Li, Yanyan; Liu, Wei; Zheng, Jincheng; Wei, Haibo; Wang, Jinghua; Lu, Xin; Kong, Hongwei; Xu, Guowang

2003-11-26

66

[Distribution of sulfur-containing compounds in the gasoline range petroleum products].  

PubMed

A capillary gas chromatography coupled with sulfur chemiluminescence detection (GC-SCD) method has been developed for detailed analysis and group-type characterization of sulfur compounds in gasoline range petroleum products. Chemical treatment of the samples was carried out using selective reactions for group-type classification of compounds. A total of 107 sulfur compounds were tentatively classified and identified based on standard substances and retention rule. The relative standard deviations (RSDs) of retention times were no more than 0.25%. The quantitative analysis on major sulfur compounds and total sulfur was carried out based on the linear response of sulfur chemiluminescence detector and the internal standard method. The recoveries were in the range of 96% - 115%. For the sulfur-containing compounds whose concentration exceeded 7 mg/kg, the RSDs of the determination were less than 8.9%. Various types of gasoline were analyzed and their sulfur distributions were investigated using the developed method. The results show that the method can be used to separate, identify and quantitate sulfur-containing compounds. PMID:15706942

Hua, Ruixiang; Li, Yanyan; Zheng, Jincheng; Wang, Jinghua; Lu, Xin; Xu, Guowang

2004-09-01

67

Lunar sulfur  

NASA Technical Reports Server (NTRS)

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.

Kuck, David L.

1991-01-01

68

Identification and quantification of sulfur and nitrogen containing odorous compounds in wastewater  

Microsoft Academic Search

Sulfur and nitrogen containing malodorous compounds were identified and quantified in the samples taken from each step of sewage treatment employing aerated biofilters for advanced treatment. The sulfur compounds hydrogen sulfide, carbon disulfide, methyl mercaptan, dimethyl sulfide and dimethyl disulfide were detected by using GC-FPD with a headspace method and a modified purge and cold trap method. With a purge

Yongwoo Hwang; Tomonori Matsuo; Keisuke Hanaki; Noriyuki Suzuki

1995-01-01

69

SULFUR COMPOUNDS IN HIGH-BOILING FRACTIONS OF SAUDI ARABIAN CRUDE OIL  

Microsoft Academic Search

This study describes the isolation and characterization of sulfur compound types in high boiling distillate of Arab crude oil. Thu distillates were prepared by physical and chemical methods like adsorption chromatography and complexation with mercurous nitrate and iodine. Spectrophotometry methods were used for detection and identification. The sulfur compound types, thus obtained, were classified into aliphatic sulfides, aromatic sulfides, and

Mohammad Farhat Ali II Pcrzanowski; Shcrif A. Korcish

1991-01-01

70

Sensitive quantification of sulfur compounds in wine by headspace solid-phase microextraction technique  

Microsoft Academic Search

A sensitive solid-phase microextraction and gas chromatography-pulsed flame photometric detection technique was developed to quantify volatile sulfur compounds in wine. Eleven sulfur compounds, including hydrogen sulfide, methanethiol, ethanethiol, dimethyl sulfide, diethyl sulfide, methyl thioacetate, dimethyl disulfide, ethyl thioacetate, diethyl disulfide, dimethyl trisulfide and methionol, can be quantified simultaneously by employing three internal standards. Calibration curves were established in a synthetic

Yu Fang; Michael C. Qian

2005-01-01

71

Environmental Chamber Test Protocol for Measuring Chemical Emissions, Including Sulfur Compounds from Drywall with Preliminary Results  

Microsoft Academic Search

Recently, drywall produced in China has been implicated as the cause of health complaints and corrosion of metal components in houses, with sulfur compounds as the potential source. Federal and state agencies are interested in determining if sulfur containing chemicals are being released from this drywall and identifying the compounds. To assist these agencies, as well as product manufacturers and

Stephany I. Mason; Tony Worthan

72

DETERMINATION OF ORGANIC SULFUR COMPOUND TYPES IN VACUUM GAS OILS USING GC-FID-SCD METHOD  

Microsoft Academic Search

The analyses of individual organic sulfur compounds in petroleum distillates are the key to understanding the kinetics of the chemistry involved in hydrodesulfurization, HDS. A sample of vacuum gas oil (VGO) produced commercially by distillation of treated atmospheric residue was analyzed by GC-FID-SCD method for individual organic sulfur compounds characterization and quantification. Dibenzothiophene and benzonaphthothiophene and their alkyl derivatives were

H. Behbehani; M. K. Andari

2000-01-01

73

Cysteine sulfoxides and volatile sulfur compounds from Allium tripedale.  

PubMed

Allium tripedale Trautv. belonging to the subgenus Nectaroscordum grows naturally in the mountainous areas of northwest Iran. Leaves have a very strong and somewhat unpleasant taste and are widely used by the local population as a spicy vegetable. Three new cysteine based compounds were identified in A. tripedale as the first examples of sulfur containing 1-butenyl derivatives in nature. The compounds have been described as o-phthaldialdehyde (OPA) derivatives and identified as (+)-S-(1-butenyl)-L-cysteine sulfoxide (homoisoalliin) and its gamma-glutamyl derivative as well as the gamma-glutamyl derivative of S-(1-butenyl)-L-cysteine (desoxyhomoisoalliin). These cysteine sulfoxides have been also found in Allium siculum Ucria. As volatile compounds, di-(1-butenyl)-disulfide and the cepaene-like compounds di-(1-S-sulfoxymethyl-butyl)-disulfide, 1-S-sulfoxymethyl-butyl-1'-S-sulfoxy-1-butenyl-butyl-disulfide and 1-S-sulfoxymethyl-butyl-1'-S-sulfoxybutyl-butyl-disulfide could be tentatively identified by various MS experiments. Primary products resulting from the alliinase reaction of homoisoalliin seem to be highly unstable and were rapidly converted to the volatile compounds listed above. PMID:20030404

Kusterer, Jan; Keusgen, Michael

2010-01-27

74

Sulfuric odorous compounds emitted from pig-feeding operations  

NASA Astrophysics Data System (ADS)

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

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

75

Sulfur K-edge X-ray absorption spectroscopy of petroleum asphaltenes and model compounds  

SciTech Connect

The utility of sulfur K-edge X-ray absorption spectroscopy for the determination and quantification of sulfur forms in petroleum asphaltenes has been investigated. Both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectra were obtained for a selected group of model compounds and for several petroleum asphaltene samples. For the model compounds the sulfur XANES was found to vary widely from compound to compound and to provide a fingerprint for the form of sulfur involved. The use of third derivatives of the spectra enabled discrimination of mixtures of sulfidic and thiophenic model compounds and allowed approximate quantification of the amount of each component in the mixtures and in the asphaltene samples. These results represent the first demonstration that nonvolatile sulfur forms can be distinguished and approximately quantified by direct measurement.

George, G.N.; Gorbaty, M.L. (Exxon Research and Engineering Co., Annandale, NJ (USA))

1989-04-26

76

Process for the hydrodesulfurization of natural gas containing organic sulfur compounds and oxygen  

Microsoft Academic Search

Process is claimed for hydrodesulfurizing a gas comprising together methane, at least one organic sulfur compound and oxygen, characterized by the step of passing a mixture of said gas with a hydrogen containing gas on a palladium catalyst at a temperature of 300° to 450° C. The gas usually comprises at least 2 mg\\/Nm³ of sulfur as organic sulfur and

A. Deschamps; J. Cosyns; J. F. Le Page

1984-01-01

77

Determination of sulfur compounds in non-polar fraction of vacuum gas oil  

Microsoft Academic Search

Sulfur compounds in the non-polar fraction, which represents 73 wt% of total sulfur in a vacuum gas oil (VGO), were analysed by sulfur-selective ligand exchange chromatography combined with high-performance liquid chromatographic (h.p.l.c.) separation on the basis of aromatic ring number, with subsequent capillary g.c.-mass spectrometry for identification. Quantification was achieved by independent h.p.l.c. separation based on aromatic ring number followed

Xiaoliang Ma; Kinya Sakanishi; Takaaki Isoda; Isao Mochida

1997-01-01

78

Io kagobutsu no kansei chinchakuryo ni kansuru kento. (Estimate of dry deposition of sulfur compounds in Japan).  

National Technical Information Service (NTIS)

Dry deposition of sulfur compounds was studied. Direct deposition of sulfur compounds as gas or particulates without the help of precipitation is called dry deposition. The deposition velocities (V) of SO (sub 2) gas and sulfate particulates are governed ...

S. Fujita A. Takahashi

1990-01-01

79

Role of reduced sulfur compounds in nutrition of Propionibacterium acnes.  

PubMed Central

In a study of the nutritional requirements of Propionibacterium acnes, acid hydrolyzed casein was shown to be the preferred nitrogen source in a glycerol-salts medium. Of 22 individual amino acids tested, only cysteine supported growth in the glycerol-salts medium. This indicated a requirement not only for amino nitrogen but also for reduced sulfur. In the presence of an auxiliary nitrogen source, thioglycolate or thiosulfate could replace sulfur-containing amino acids. The apparent requirement of P. acnes for reduced sulfur possibly could be satisfied in vivo by the constant availability of this substance in the form of sulfhydryl groups in the sebaceous follicle during keratinization. The relationship between P. acnes and its nutritional substrate may give this organism a selective advantage to exist in this ecological niche.

Nielsen, P A

1983-01-01

80

Selective removal of sulfur compounds in city-gas by adsorbents  

Microsoft Academic Search

Silver nitrate impregnated on beta zeolite (BEA), mesoporous silica MCM-41 and SBA-15 (AgNO3\\/BEA, AgNO3\\/MCM-41, AgNO3\\/SBA-15) were prepared to remove sulfur compounds selectively in city-gas, which contains tetrahydrothiophene and tert-butylmercaptane. Sulfur adsorption capacity was determined when the sulfur concentration of effluent gas in breakthrough\\u000a test reached 0.1 ppm, which is acceptable sulfur concentration for hydrogen production in a reformer for fuel

Chang Hyun Ko; Hirn-Ill Song; Jong-Ho Park; Sang-Sup Han; Jong-Nam Kim

2007-01-01

81

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

EPA Science Inventory

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

82

Degradation of organic sulfur compounds by a coal-solubilizing fungus.  

National Technical Information Service (NTIS)

Paecilomyces sp. TLi, a coal-solubilizing fungus, was shown to degrade organic sulfur-containing coal substructure compounds. Dibenzothiophene was degraded via a sulfur-oxidizing pathway to 2.2'-biphenol. No further metabolism of the biphenol was observed...

B. D. Faison T. M. Clark S. N. Lewis D. M. Sharkey C. A. Woodward

1990-01-01

83

SULFUR COMPOUND TYPE DISTRIBUTION IN NAPHTHA AND GAS OIL FRACTIONS OF KUWAITI CRUDE  

Microsoft Academic Search

The need for detailed information on the types of sulfur compounds present in various petroleum cuts has been well recognized by refiners and environmentalists worldwide. This need is growing in recent years in view of the current environmental regulations that limit the sulfur content of transportation fuels to very low levels. In the present work we have studied the distribution

M. K. Andari; H. Bchbehani; A. Stanislaus

1996-01-01

84

Production of volatile organic sulfur compounds (VOSCs) by basidiomycetous yeasts.  

PubMed

Thirty-seven basidiomycetous yeasts belonging to 30 species of seven genera were grown on media containing l-cysteine or l-methionine as sole nitrogen sources with the objective of evaluating volatile organic sulfur compound (VOSC) production. The headspace of yeast cultures was analyzed by the solid-phase microextraction (SPME) sampling method, and volatile compounds were quantified and identified by GC-MS techniques. Ten strains assimilating L-methionine produced the following VOSCs: 3-(methylthio)-1-propanol, methanethiol, S-methyl thioacetate, dimethyl disulfide, dimethyl trisulfide, allyl methyl sulphide and 4,5-dihydro-3(2H)-thiophenone. Production was <1 mgl(-1) except for 3-(methylthio)-1-propanol of which between 40 and 400 mgl(-1) was synthesized. Higher alcohols (isobutyl alcohol, isoamyl alcohol and active amyl alcohol) and esters (ethyl acetate, ethyl propionate, n-propyl acetate, isobutyl acetate, n-propyl propionate, n-butyl acetate, isoamyl acetate, amyl acetate, isoamyl propionate, amyl propionate and 2-phenylmethyl acetate) were also sporadically produced. This is the first report of VOSCs production by basidiomycetous yeasts. Consequently, basidiomycetous yeasts may be considered an interesting new group of microbial VOSCs producers for the flavor industry. PMID:15691743

Buzzini, Pietro; Romano, Sergio; Turchetti, Benedetta; Vaughan, Ann; Pagnoni, Ugo Maria; Davoli, Paolo

2005-02-01

85

A new class of cathode materials for rechargeable magnesium batteries: Organosulfur compounds based on sulfur–sulfur bonds  

Microsoft Academic Search

A class of energy storage materials, organosulfur compounds with S–S bonds, has been proposed as novel cathode materials for rechargeable magnesium batteries. The cleavage and recombination of S–S bonds formed during discharge and charge process are the key components for the capacity. The cathode performance of three organosulfur materials, i.e. 2,5-dimercapto-1,3,4-thiadiazole (DMcT), poly-2,2?dithiodianiline (PDTDA) and a conductive sulfur-containing material (CMS)

Yanna NuLi; Zaiping Guo; Huakun Liu; Jun Yang

2007-01-01

86

BIOGENIC SULFUR COMPOUNDS IN COASTAL ATMOSPHERES OF NORTH CAROLINA  

EPA Science Inventory

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

87

Removal of sulfur compounds from a gas stream  

US Patent & Trademark Office Database

A method and apparatus for eliminating COS and/or CS.sub.2 from a hydrocarbon-containing feed stream, and further eliminating H.sub.2S from such feed stream or converting all sulfur species in such feed stream to H.sub.2S and SO.sub.2 to allow for easy subsequent conversion of such H.sub.2S and SO.sub.2 to elemental sulfur in a Claus reaction. The method comprises: (i) injecting water so that the feed stream contains greater than 10 vol % (water equivalent); (ii) passing the feed stream through catalyst means which hydrogenates COS and/or CS.sub.2 to H.sub.2S; (iii) injecting O.sub.2 so that the stoichiometric ratio of O.sub.2 to H.sub.2S is at least 0.5:1.0; (iv) passing the stream though a reaction zone having oxidation catalyst means which oxidizes H.sub.2S to elemental sulfur or SO.sub.2 (depending on the amount of oxygen and water added); where the temperature of the reaction zone is above the elemental sulfur dew point.

2014-04-22

88

No sulfur flows on Io  

NASA Technical Reports Server (NTRS)

Physical and chemical properties of elemental sulfur are incompatible with the suggestion that the colored flows associated with volcanoes on Io are quenched unstable allotropes of sulfur. Either the volcanic flows are not sulfur, or some mechanism other than quenching is required to produce colored forms of sulfur in them. The properties of sulfur are unsuited to the production and survival of colored unstable allotropes on Io. The color of this object is probably due to some other material, possibly iron compounds.

Young, A. T.

1984-01-01

89

Sulfur Earth  

NASA Astrophysics Data System (ADS)

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 those observed on the Earth's surface and are mimicked by lows under the oceans and highs under the altiplanos. Careful and area selective S wave core mantle ellipsometry might be able to discern these core-mantle topographic variations. As such this process demonstrates the validity of the Gaia hypothesis enunciated by Baas Becking(1931) that no ecological niche on our planet is closed off from other niches "nothing in the world is single".

de Jong, B. H.

2007-12-01

90

Metal phosphate reduction in the presence of gaseous sulfur compounds  

SciTech Connect

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

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

1992-05-20

91

Capillary GC (Gas Chromatography) Detection Methods for Nitrogen and Sulfur Compounds in Shale-Derived Jet Propulsion Fuels.  

National Technical Information Service (NTIS)

Correlations have been drawn between nitrogen and sulfur content in jet propulsion fuel and poor fuel performance. Recent studies have suggested that certain nitrogen and sulfur compound classes are more detrimental to fuel performance than others. This r...

E. M. Steward E. W. Pitzer

1986-01-01

92

Lunar Sulfur.  

National Technical Information Service (NTIS)

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 t...

D. L. Kuck

1991-01-01

93

Separation and Selective Detection of Sulfur Compounds in Heavy Petroleum Fractions. Geochemistry of Benzo (B) Thiophenes.  

National Technical Information Service (NTIS)

Quantitative analysis of sulfur compounds in a heavy cut of ARAMCO 90 petroleum is studied for the simulation of true boiling point distillation curve. The fraction is analysed by gas chromatography. Detection by flame photometry and high resolution mass ...

N. Perakis

1986-01-01

94

Pre-Methanation Purification Study: Removal of Low Concentration Gaseous Sulfur Compounds (Catalyst Poisons).  

National Technical Information Service (NTIS)

Before catalytic methanation can be used for the commercial production of synthetic natural gas from synthesis gas, the problem of methanation catalyst deactivation must be solved. The nickel catalyst used is easily poisoned by sulfur compounds. It was th...

E. P. Iaccarino M. Lieberman W. F. Taylor

1978-01-01

95

[Distribution and sources of oxygen and sulfur heterocyclic aromatic compounds in surface soil of Beijing, China].  

PubMed

62 surface soil samples were collected from different environmental function zones in Beijing. Sulfur and oxygen heterocyclic aromatic compounds were detected by GC/MS. The objectives of this study were to identify the composition and distribution of these compounds, and discuss their sources. The results showed that the oxygen and sulfur heterocyclic aromatic compounds in the surface soils mainly contained dibenzofuran, methyl- and C2-dibenzofuran series, dibenzothiophene, methyl-, C2- and C3-dibenzothiophene series and benzonaphthothiophene series. The composition and distribution of the oxygen and sulfur heterocyclic aromatic compounds in the surface soil samples varied in the different environmental function zones, of which some factories and the urban area received oxygen and sulfur heterocyclic aromatic compounds most seriously. In Beijing, the degree of contamination by oxygen and sulfur heterocyclic aromatic compounds in the north surface soil was higher than that in the south. There were preferable linear correlations between the concentration of dibenzofuran series and fluorene series, as well as the concentration of dibenzothiophene series and dibenzofuran series. The oxygen and sulfur heterocyclic aromatic compounds in the surface soil were mainly derived from combustion products of oil and coal and direct input of mineral oil, etc. There were some variations in pollution sources of different environmental function zones. PMID:22295625

He, Guang-Xiu; Zhang, Zhi-Huan; Peng, Xu-Yang; Zhu, Lei; Lu, Ling

2011-11-01

96

Sulfuric Acid on Europa's Surface and the Radiolytic Sulfur Cycle  

NASA Astrophysics Data System (ADS)

Galileo infrared spectra of Europa's surface show distorted water bands that have been attributed to hydrated evaporite salts (McCord et al., J. Geophys. Res. 104, 11827, 1999) or to the scattering properties of ice (Dalton and Clark, Bull. Am. Astron. Soc. 30, 1081, 1998). Using new laboratory spectra, we show that hydrated sulfuric acid can explain Europa's spectra and further show that this species is a product of radiolysis. Sulfuric acid on Europa occurs as the radiolytically stable octahydrate and hemihexahydrate and is a major surface component, along with water ice. The sulfuric acid concentration correlates spatially with Europa's visually dark material, which we identify as radiolytically altered sulfur polymers. Radiolysis by incident jovian plasma continuously cycles sulfur between three chemical reservoirs: sulfuric acid, polymerized sulfur, and sulfur dioxide, with the acid being about 50 times more abundant than the other forms because of the stability of the sulfate anion under irradiation. The original source of sulfur may be incident iogenic sulfur ions or endogenic sulfur compounds that are altered by radiolysis. Geological processes can bury and redistribute the sulfurous material, producing a sulfur-rich crust and a non-uniform surface distribution. The low melting point of sulfuric acid and its ability to supercool may facilitate geological processes. Europa's magnetic response may be influenced by the electrical conductivity of sulfuric acid.

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

1999-09-01

97

A study of the adsorption of thiophenic sulfur compounds using flow calorimetry  

Microsoft Academic Search

Selective adsorption of sulfur compounds from gasoline and diesel fuel has potential to produce ultra clean fuels for on-board fuel cell applications and also to meet the upcoming legislation for clean fuels. Removal of thiophenic sulfur compounds in a hexadecane solution using commercial zeolites, NaY, USY, HY and 13X, has been investigated by adsorption and flow calorimetry techniques. The S

Flora T. T. Ng; Ataur Rahman; Tomotsugu Ohasi; Ming Jiang

2005-01-01

98

Determination of Atmospheric Sulfur Compounds Near a Volcanic Area in Greece  

Microsoft Academic Search

Volcanoes have been identified as an important natural source of sulfur compounds such as H2S, CS2, SO2 and COS. The emission of volcanic sulfur compounds lead to the formation of sulfate aerosol and contribute to the acidity\\u000a of precipitation.\\u000a \\u000a Two weekly measuring campaigns have been performed in the non-erupting volcanic area of Sousaki, Korinthou, to determine the\\u000a concentration levels of

Ch. Vasilakos; Th. Maggos; J. G. Bartzis; P. Papagiannakopoulos

2005-01-01

99

Determination of sulfur compound distribution in petroleum by gas chromatography with a flame photometric detector  

Microsoft Academic Search

A simulated distillation using a flame photometric detector (FPD) is reported for determining the boiling range distribution of sulfur-containing compounds in middle-to-heavy petroleum distillates. Its success is based on a new calibration method for the FPD involving converting all the sulfur-containing compounds to SOâ before detection and linearizing the data. A single calibration equation is formulated expressing a uniform and

Cherlynlavaughn. Bradley; Douglas J. Schiller

1986-01-01

100

Process for forming sulfuric acid  

DOEpatents

An improved electrode is disclosed for the anode in a sulfur cycle hydrogen generation process where sulfur dioxie is oxidized to form sulfuric acid at the anode. The active compound in the electrode is palladium, palladium oxide, an alloy of palladium, or a mixture thereof. The active compound may be deposited on a porous, stable, conductive substrate.

Lu, Wen-Tong P. (Upper St. Clair, PA)

1981-01-01

101

A solvent system to provide selective removal of sulfur compounds  

SciTech Connect

Energy costs and SRU inefficiencies resulting from utilization of low strength MEA technology induced a large refinery to convert to MDEA. One of the seven product streams being treated required extremely low carbonyl sulfide in the treated product. This required careful consideration in making the decision to convert. However, the conclusions were that the advantages outweighed the disadvantages. When the initial converted operations verified a need to improve the carbonyl sulfide removal, GAS/SPEC Tech Service produced an innovative solution which allowed for efficient operation at acceptable COS specification, lower energy utilization, reduced solvent losses, and improved sulfur recovery unit operation.

Pearce, R.L.; Bacon, T.R.

1986-01-01

102

A feasibility study on thermochemical water-splitting cycles using sulfur compounds  

Microsoft Academic Search

Several thermochemical cycles were studied: (1) Cu-Cl hybrid cycle, (2) SO2 hybrid cycle, (3) SO2-I2 cycle, (4) SO2-I2-Benzene cycle, (5) SO2-Methanol-Iodine cycle and (6) SO2-H2S cycle. Except for the Cu-Cl hybrid cycle, these cycles utilize sulfur compounds and involve the thermal decomposition reaction of sulfuric acid as the oxygen evolving reaction. A test performance of an iron catalyst was carried

M. Dokiya; K. Fukuda; T. Kameyama; H. Yokokawa

1979-01-01

103

Zeolites Remove Sulfur From Fuels  

NASA Technical Reports Server (NTRS)

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.

Voecks, Gerald E.; Sharma, Pramod K.

1991-01-01

104

Bacterial Sulfur Globules: Occurrence, Structure and Metabolism  

Microsoft Academic Search

Reduced sulfur compounds such as sulfide, polysulfides, thiosulfate, polythionates, and elemental sulfur are oxidized by a\\u000a large and diverse group of prokaryotes, including the phototrophic sulfur bacteria, the thiobacilli and other colorless sulfur\\u000a bacteria and some thermophilic Archaea. Typically, these sulfur compounds are oxidized to sulfate but in many cases globules of polymeric, water-insoluble sulfur\\u000a accumulate as a transient and

Christiane Dahl; Alexander Prange

105

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

USGS Publications Warehouse

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

Chou, M. -i. M.; Lake, M. A.; Griffin, R. A.

1988-01-01

106

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

NASA Technical Reports Server (NTRS)

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

Gradie, Jonathan C.

1987-01-01

107

Flow calorimetric and thermal gravimetric study of adsorption of thiophenic sulfur compounds on NaY zeolite  

Microsoft Academic Search

A study of adsorption of thiophenic sulfur compounds (thiophene, benzothiophene, dibenzothiophene and 4,6-dimethyl benzothiophene) in normal alkane solvents (octane, dodecane and hexadecane) on NaY zeolite has been performed by using flow calorimetry technique and thermogravimetric analysis. The measured heat of adsorption of sulfur compounds includes the heat from the displacement of the adsorbed solvent molecules by sulfur compounds and it

Ming Jiang; Flora T. T. Ng; Ataur Rahman; Viral Patel

2005-01-01

108

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

NASA Astrophysics Data System (ADS)

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

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

2003-04-01

109

Anti-Inflammatory Activity of Sulfur-Containing Compounds from Garlic  

PubMed Central

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

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

2012-01-01

110

Method for removing sulfur compounds from C/sub 6/ and lower alkanes  

SciTech Connect

A process is described for recovering a low sulfur content hydrocarbon fraction having a boiling point of n-hexane or less from a hydrocarbon stream containing hydrocarbons boiling at or below the boiling point of hexane and organic sulfur compounds comprising monosulfides boiling at or below the boiling point of n-hexane. It consists of contacting the hydrocarbon stream with a dilute aqueous solution of sodium hypochlorite for a time sufficient to convert a selected amount of monosulfide compounds present to compounds having boiling points above the boiling point of n-hexane, separating an aqueous phase and a hydrocarbon phase and fractionally distilling the hydrocarbon phase to recover a hydrocarbon fraction having a boiling point of n-hexane or less, and having a reduced amount of the organic sulfur compounds.

Keyworth, D.A.

1989-03-28

111

Lithium polysulfidophosphates: a family of lithium-conducting sulfur-rich compounds for lithium-sulfur batteries.  

PubMed

Sulfur-rich lithium polysulfidophosphates (LPSPs) act as an enabler for long-lasting and efficient lithium-sulfur batteries. LPSPs have ionic conductivities of 3.0×10(-5) ?S?cm(-1) at 25?°C, which is 8 orders of magnitude higher than that of Li2S. The high lithium ion conductivity imparts excellent cycling performance, and the batteries are configured in an all-solid state, which promises safe cycling with metallic lithium anodes. PMID:23737078

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

2013-07-15

112

The effect of sulfur compounds on H 2 evolution\\/consumption reactions, mediated by various hydrogenases, in the purple sulfur bacterium, Thiocapsa roseopersicina  

Microsoft Academic Search

The influence of reduced sulfur compounds (including stored S0) on H2 evolution\\/consumption reactions in the purple sulfur bacterium, Thiocapsa roseopersicina BBS, was studied using mutants containing only one of the three known [NiFe] hydrogenase enzymes: Hox, Hup or Hyn. The observed\\u000a effects depended on the kind of hydrogenase involved. The mutant harbouring Hox hydrogenase was able to use S2O32?, SO32?,

Tatyana V. Laurinavichene; Gábor Rákhely; Kornél L. Kovács; Anatoly A. Tsygankov

2007-01-01

113

catalytic effects of sulfur and other compounds in the azide-iodine test  

Microsoft Academic Search

In the azide-iodine reaction employed for corroslvity testing, nitrogen gas evolution is catalyzed by reduced compounds of sulfur. The test is not specific, since many other compounds have similar catalytic effects. Thus test results should be interpreted with caution because of interference from a variety of materials.

Olli H. Tuovinen; William J. Lapple; David M. Mair

1981-01-01

114

Observation of sorptive losses of volatile sulfur compounds during natural gas sampling  

Microsoft Academic Search

The reason for the compound-dependent over-estimation of the recoveries of several volatile organic sulfur compounds when using a Silcosteel cylinder for sample storage as reported earlier was examined. From the different possible sources of errors that were taken into consideration, the silicone tubing, which was used to fill a standard Tedlar sample bag for calibration, was identified as the cause

Michael Sulyok; Christina Haberhauer-Troyer; Erwin Rosenberg

2002-01-01

115

Differential Protein Expression during Growth of Acidithiobacillus ferrooxidans on Ferrous Iron, Sulfur Compounds, or Metal Sulfides  

PubMed Central

A set of proteins that changed their levels of synthesis during growth of Acidithiobacillus ferrooxidans ATCC 19859 on metal sulfides, thiosulfate, elemental sulfur, and ferrous iron was characterized by using two-dimensional polyacrylamide gel electrophoresis. N-terminal amino acid sequencing and mass spectrometry analysis of these proteins allowed their identification and the localization of the corresponding genes in the available genomic sequence of A. ferrooxidans ATCC 23270. The genomic context around several of these genes suggests their involvement in the energetic metabolism of A. ferrooxidans. Two groups of proteins could be distinguished. The first consisted of proteins highly upregulated by growth on sulfur compounds (and downregulated by growth on ferrous iron): a 44-kDa outer membrane protein, an exported 21-kDa putative thiosulfate sulfur transferase protein, a 33-kDa putative thiosulfate/sulfate binding protein, a 45-kDa putative capsule polysaccharide export protein, and a putative 16-kDa protein of unknown function. The second group of proteins comprised those downregulated by growth on sulfur (and upregulated by growth on ferrous iron): rusticyanin, a cytochrome c552, a putative phosphate binding protein (PstS), the small and large subunits of ribulose biphosphate carboxylase, and a 30-kDa putative CbbQ protein, among others. The results suggest in general a separation of the iron and sulfur utilization pathways. Rusticyanin, in addition to being highly expressed on ferrous iron, was also newly synthesized, as determined by metabolic labeling, although at lower levels, during growth on sulfur compounds and iron-free metal sulfides. During growth on metal sulfides containing iron, such as pyrite and chalcopyrite, both proteins upregulated on ferrous iron and those upregulated on sulfur compounds were synthesized, indicating that the two energy-generating pathways are induced simultaneously depending on the kind and concentration of oxidizable substrates available.

Ramirez, Pablo; Guiliani, Nicolas; Valenzuela, Lissette; Beard, Simon; Jerez, Carlos A.

2004-01-01

116

Sulfuric acid-sulfur heat storage cycle  

DOEpatents

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

Norman, John H. (LaJolla, CA)

1983-12-20

117

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

DOEpatents

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

Siriwardane, Ranjani

2004-06-01

118

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

SciTech Connect

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

Foye, W.O. (Massachusetts College of Pharmacy and Allied Health Sciences, Boston (United States))

1992-09-01

119

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

SciTech Connect

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

Ogata, M.; Miyake, Y.

1980-11-01

120

Future Sulfur Dioxide Emissions  

Microsoft Academic Search

The importance of sulfur dioxide emissions for climate change is now established, although substantial uncertainties remain. This paper presents projections for future sulfur dioxide emissions using the MiniCAM integrated assessment model. A new income-based parameterization for future sulfur dioxide emissions controls is developed based on purchasing power parity (PPP) income estimates and historical trends related to the implementation of sulfur

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

2005-01-01

121

The effects of biodegradation and water washing on sulfur compound speciation in crude oils from the Bolivar Coastal Fields  

SciTech Connect

A series of crude oils from a partially and heavily biodegraded reservoir were analyzed fro sulfur compound speciation by x-ray absorption spectroscopy. The most reasonable explanation of the data is that they represent a maturity sequence. There is no strong evidence that biodegradation or water washing produce any major changes in sulfur compound speciation. 9 refs., 1 fig., 1 tab.

Manowitz, B.; Jeon, Y.

1991-08-01

122

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

Microsoft Academic Search

The authors determined that the organic sulfur compounds usually contained in crude oil can be used as a marker of oil pollution in shellfish and fish. Short-necked clams and eels were maintained in a controlled laboratory environment in water with suspension of crude oil. Mass spectra and mass chromatograms of short-necked clam extract showed the presence of organic sulfur compounds.

M. Ogata; Y. Miyake

1980-01-01

123

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

SciTech Connect

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

Beyhan, Shirin; Urquhart, Stephen G. [Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9 (Canada); Hu Yongfeng [Canadian Light Source, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C6 (Canada)

2011-06-28

124

Group composition of sulfur compounds in distillate fuels and method for determining this composition  

Microsoft Academic Search

1.A method has been developed for the systematic determination of the group composition of sulfur compounds present in distillate fuels: mercaptans, sulfides, thiophenes, and oxygen-containing compounds.2.A method is proposed for quantitative recovery from the fuels (without change in original composition) of oxygen-containing compounds, high-purity sulfides, and thiophenes in the form of a thiophene-aromatic concentrate.3.These methods have been used in establishing

Ya. B. Chertkov; E. P. Seregin; T. I. Kirsanova; A. N. Romanov; T. A. Lifanova

1976-01-01

125

ENAMAP-2 AIR POLLUTION MODEL FOR LONG-RANGE TRANSPORT OF SULFUR AND NITROGEN COMPOUNDS  

EPA Science Inventory

This report describes the Eastern North American Model for Air Pollution (ENAMAP-2), which simulates the long-range transport and deposition of air pollutants across eastern North America. There are two versions of the model-one for sulfur compounds (ENAMAP-2S) and one for nitrog...

126

Fluorine-induced chemiluminescence detection of biologically methylated tellurium, selenium, and sulfur compounds  

Microsoft Academic Search

The sensitive detection of volatile, methylated selenium and tellurium compounds based on capillary gas chromatography coupled to fluorine-induced chemiluminescence detection is described. The method requires no sample derivatization, and the detection limits for selenides and tellurides (low pg range) are the lowest reported to date. This technique can resolve and speciate complex mixtures of methylated tellurium, selenium, and sulfur gases

T. G. Chasteen; G. M. Silver; J. W. Birks; R. Fall

1990-01-01

127

Oral malodor in children and volatile sulfur compound- producing bacteria in saliva: preliminary microbiological investigation  

Microsoft Academic Search

Purpose: This study examined and compared levels of salivary bacteria which produced volatile sulfur compounds (VSC) in young children with and without oral malodor. Methods: Clinic populations of children aged two to seven years, whose parents presented with an unsolicited major complaint of oral malodor in their child (OM+), or aged-matched controls in whom oral malodor was not detected by

Fariba Paryavi-Gholami; Glenn E. Minah; Foo Turng

1999-01-01

128

Extraction of odorizing sulfur compounds from natural gas and reodorization therewith  

Microsoft Academic Search

Linde AG's new approach permits natural gas odorants to be removed from natural gas before it is liquefied by peakshaving plants and to be saved for reinjection when the natural gas is vaporized. The odorants, mainly organic sulfur compounds, are removed by scrubbing natural gas prior to natural gas liquefaction and then freed of other impurities such as COâ, HâO,

A. Kruis; H. Karwat

1975-01-01

129

Finishing process for the removal of sulfur compounds from a gas steam  

Microsoft Academic Search

The invention relates to a finishing process for the removal of low level concentrations of mercaptans, sulfides and disulfides from a gas stream, especially a natural gas stream. The sulfur compounds are washed from the gas stream with a solution containing hydrogen peroxide, sodium carbonate or sodium hydroxide, and ammonia or an amine.

J. J. Tazuma; K. J. Frech

1984-01-01

130

Reduced sulfur compound exchange between the atmosphere and tropical tree species in southern Cameroon  

Microsoft Academic Search

We measured the concentrations of reduced sulfur compounds in the atmospheric boundary layer over an equatorial African rain forest. Results obtained from a dirigible hot air balloon and a tethered balloon system in the early morning hours reflect a multilayered structure of the atmospheric boundary layer with gradients of COS and CS2 indicating an uptake\\/production of these trace gases by

Jürgen Kesselmeier; Franz X. Meixner; Uwe Hofmann; Ayité-Lô Ajavon; Stephan Leimbach; Meinrat O. Andreae

1993-01-01

131

Development of a pretreatment system for the analysis of atmospheric reduced sulfur compounds.  

PubMed

A new pretreatment system was used to evaluate a technology to analyze reduced sulfur compounds (RSCs). To conduct this research, a self-developed custom dryer (Desolvator) and a thermal desorber system (TDS) were installed in the front of GC/PFPD. The syringe pump inside the TDS was devised in such a way that it can be desorbed in a relatively low desorption temperature and low vacuum (730 Pa). When comparing water removal efficiency of the Desolvator and frequently used Nafion dryer, the removal efficiency of the Desolvator stood between 94.6 and 96.1%, considerably higher and more stable than the Nafion dryer (81.3-94.5%). Moreover, analyses were made under various conditions in order to minimize the loss of samples when analyzing sulfur compounds using the TDS, and it was determined that adsorption temperatures less than -25 °C and a flow rate of 50 mL/min were appropriate for the efficient analysis of these sulfur compounds. Moreover, the desorption flow rate and the degree of a vacuum were found to be significant variables for the RSCs desorption. Besides, it was observed that a peculiar peak was formed by thermal decomposition when some sulfur compounds were rapidly desorbed at high desorption temperatures. PMID:24127877

Son, Youn-Suk; Lee, Gangwoong; Kim, Jo-Chun; Han, Jin-Seok

2013-11-01

132

Pre-methanation purification study: removal of low concentration gaseous sulfur compounds (catalyst poisons)  

Microsoft Academic Search

Before catalytic methanation can be used for the commercial production of synthetic natural gas from synthesis gas, the problem of methanation catalyst deactivation must be solved. The nickel catalyst used is easily poisoned by sulfur compounds. It was the purpose of this program to identify and develop a viable and effective pre-methanation purification system to protect the methanation catalyst and

E. P. Iaccarino; M. Lieberman; W. F. Taylor

1978-01-01

133

Method and system for removal of sulfur compounds from gases and for regenerating spent sorbents  

Microsoft Academic Search

This patent describes a method for removing hydrogen sulfide and other sulfur compounds after a hot gas. It consists of the steps of: contacting the hot gas with at least one metal oxide sorbent in a packed, non-fluidized bed of metal oxide sorbent which moves countercurrently to the hot gas, whereby the metal oxide sorbent reacts with the hydrogen sulfide

1989-01-01

134

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

ERIC Educational Resources Information Center

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

Chasteen, Thomas G.; Bentley, Ronald

2004-01-01

135

Rotating combustion bomb for precision calorimetry. Heats of combustion of some sulfur-containing compounds  

Microsoft Academic Search

To obtain accurate heat of formation data for organic sulfur compounds, a heat of combustion calorimeter has been developed in which it is possible to rotate the bomb after the combustion. Rotation of the bomb tends to produce a thermodynamically defined final state for the combustion process, because the stirring action hastens the attainment of (a) homogeneity of the bomb

W. N. Hubbard; C. Katz; G. Waddington

1954-01-01

136

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

Microsoft Academic Search

Reduced sulfur compounds (RSCs) and non-methane volatile organic compounds (NMVOCs) emissions from concentrated animal feeding operations (CAFOs) have become a potential environmental and human health concern. Both RSCs and NMVOCs contribute to odor. In addition, RSCs also have the potential to form fine particulate matter (PMfine) and NMVOCs the potential to form ozone. Measurements of RSCs and NMVOCs emissions were

Ian Cooper Rumsey

2010-01-01

137

Sulfuric acid in the Venus clouds  

NASA Technical Reports Server (NTRS)

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

Sill, G. T.

1972-01-01

138

Microbial removal of organic sulfur from coal (bacterial degradation of sulfur-containing heterocyclic compounds): Final report, January 1--December 31, 1988  

SciTech Connect

The presence of substantial levels of sulfur in coal is a major source of air pollution, and considerable efforts are being made to devise a cost-effective way of removing the sulfur. One method is to mutate a laboratory species, Escherichia coli, an organism which is genetically well-understood and whose pathways for the metabolism of sulfur-containing amino acids have been extensively investigated. Such thiophene degraders can be genetically analyzed and the genes involved can be cloned in order to amplify their products. Dr. David Clark, Department of Microbiology, is evaluating these mutants of E. coli. The second approach is the development of naturally occurring bacteria capable of thiophene desulfurization. Characterization of the degradation of model compounds, enhancement of the desulfurization potential of the isolated strains via mutagenesis, and studies with crushed coal will comprise the approach used in this study. The screening of soil isolates for the potential to desulfurize thiophenic and other sources of organic sulfur will identify the best strains for the microbial removal of organic sulfur from coal. Ultimately, the genes responsible for thiophene degradation by the isolated strains will be transferred to an E. coli strain creating a single organism capable of degrading a broad spectrum of thiophene compounds. 14 refs., 13 tabs.

Klubek, B.

1989-03-01

139

Exploring the Arabidopsis sulfur metabolome.  

PubMed

Sulfur plays a crucial role in protein structure and function, redox status and plant biotic stress responses. However, our understanding of sulfur metabolism is limited to identified pathways. In this study, we used a high-resolution Fourier transform mass spectrometric approach in combination with stable isotope labeling to describe the sulfur metabolome of Arabidopsis thaliana. Databases contain roughly 300 sulfur compounds assigned to Arabidopsis. In comparative analyses, we showed that the overlap of the expected sulfur metabolome and the mass spectrometric data was surprisingly low, and we were able to assign only 37 of the 300 predicted compounds. By contrast, we identified approximately 140 sulfur metabolites that have not been assigned to the databases to date. We used our method to characterize the ?-glutamyl transferase mutant ggt4-1, which is involved in the vacuolar breakdown of glutathione conjugates in detoxification reactions. Although xenobiotic substrates are well known, only a few endogenous substrates have been described. Among the specifically altered sulfur-containing masses in the ggt4-1 mutant, we characterized one endogenous glutathione conjugate and a number of further candidates for endogenous substrates. The small percentage of predicted compounds and the high proportion of unassigned sulfur compounds identified in this study emphasize the need to re-evaluate our understanding of the sulfur metabolome. PMID:24147819

Gläser, Katharina; Kanawati, Basem; Kubo, Tobias; Schmitt-Kopplin, Philippe; Grill, Erwin

2014-01-01

140

Third-order nonlinear optical properties of sulfur-rich compounds  

SciTech Connect

The molecular third-order optical nonlinearity {gamma}{sub R} (second hyperpolarizability or nonlinear refractive index) was measured for a series of sulfur-rich molecules: sulfur (S{sub 8}), carbon-sulfur compounds, and metal thiolate clusters. Z-scan techniques (pulse width 27 ps, wavelength 527 nm) were used to measure these properties in solution by comparing the solution to the pure solvent. The authors approach is an efficient way to evaluate a number of different compounds and to quickly direct synthetic strategies for improved nonlinear and linear optical properties. The optical nonlinearities were evaluated in terms of figures of merit {vert{underscore}bar}W{vert{underscore}bar}/I{sub 0} and [T]{sup {minus}1}, where {vert{underscore}bar}W{vert{underscore}bar}/I{sub 0} is the ratio of nonlinear refraction to linear absorption and [T]{sup {minus}1} is the ratio of nonlinear refraction to nonlinear absorption. Among the carbon-sulfur compounds, C{sub 6}S{sub 8}O{sub 2} had the largest figures of merit: {vert{underscore}bar}W{vert{underscore}bar}/I{sub 0} = 4.3 x 10{sup {minus}13} m{sup 2} W{sup {minus}1} and [T]{sup {minus}1} > 5. The metal thiolate cluster with the largest second hyperpolarizability was [Zn{sub 10}S{sub 4}(SPh){sub 16}]{sup 4{minus}} ({gamma}{sub R} = {minus}7.8 x 10{sup {minus}56} C m{sup 4} V{sup {minus}3}, {minus}6.3 x 10{sup {minus}31} esu). This cluster exhibited no measurable linear or nonlinear absorption, so the figures of merit were effectively infinite. Previous work on the second hyperpolarizability of sulfur-rich compounds examined species that were hampered by substantial linear absorption coefficients. The present work shows that high figures of merit can be achieved without significant linear or nonlinear absorption.

Breitzer, J.G.; Dlott, D.D.; Iwaki, L.K.; Kirkpatrick, S.M.; Rauchfuss, T.B.

1999-09-02

141

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

NASA Technical Reports Server (NTRS)

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

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

1996-01-01

142

Disproportionation of N-arylhydroxylamines in the presence of hydrogenation catalysts and sulfur compound additives  

SciTech Connect

Data are presented for the hydrogenation of p-chloronitrobenzene (PCNB) in the presence of a catalyst containing 2% platinum on activated charcoal and added thiophene, sulfolane, and 2,4-dimethylsulfolane in ethyl acetate at 20 C. The yield of N-arylhydroxylamines increases in the liquid-phase catalytic hydrogenation of aromatic nitro compounds due to a reduction in the rate of the secondary transformations of these products upon the introduction of thiophene, sulfolane and other sulfur compound additives.

Makaryan, I.A.; Brikenshtein, K.A.; Khidekel, M.L.; Savchenko, V.I.

1985-08-20

143

Terrestrial Remote Sensing Of Sulfur Compounds On Ice With Application To Europa  

NASA Astrophysics Data System (ADS)

The intricate pattern of geological features on the surface of Europa, with its lattice of interwoven lineaments and chaotic terrain, is accentuated by the ruddy materials concentrated along these features. Varying from the ubiquitous signature of ice which comprises the remainder of the surface of this moon, these materials show close spectral matches with sulfur-bearing salts and have been hypothesized to indicate sites where communication with a subsurface ocean has occurred. Representing as they may the only remote clue as to the composition and consequent habitability of this subsurface ocean, further constraints on the nature of these materials are required. The opportunity to evaluate and refine our abilities to successfully identify sulfur compounds on ice by means of orbital remote sensing techniques has arisen in the form of a terrestrial field site in the Canadian High Arctic. Borup Fiord Pass is home to a glacier onto which sulfur-rich springs discharge, leading to the formation of extensive deposits of elemental sulfur and gypsum such as those observed in the 2006 field season. Our investigations revealed an area of ice many hundred meters squared onto which outflow from channels, likely active at various stages over the winter, had produced a buildup of yellow to brown sulfur-rich materials. Spectral reflectance measurements obtained in the field of these sulfur-rich deposits will be utilized as spectral endmembers for subpixel analysis of Hyperion hyperspectral data obtained in a similar timeframe. Data on the relationship between spectral signatures from orbit and their appearance in the field will allow us to return to the Europa dataset to improve on our knowledge of the composition of the materials present there.

Gleeson, Damhnait F.

2006-09-01

144

Determination of sulfur compounds in coal by mass spectrometry, correlated with XANES and XPS  

SciTech Connect

The objective of this study is to identify important organic sulfur-containing compounds in the Argonne Premium Coals and in selected, separated coal macerals. In-source, desorption/pyrolysis high resolution mass spectrometry is being used to characterize the volatile species of whole coals, macerals, and their extracts. To examine the possibility of secondary reactions and undesirable selectivity, the MS data is compared to data from direct techniques, XANES and XPS. The MS results con-elate very well which supports the suggestion that the species seen are indigenous to the original sample. Therefore, specific structural assignments to the sulfur species can be made. Quantitative speciation of organic sulfur in coals has been accomplished by both XANES and XPS with what appears to be good reliability. Mass spectrometry approaches provide more detailed molecular information, but suffer from problems with sampling. In the past we have found it difficult to isolate aliphatic sulfur compounds by thermal desorption or pyrolysis due to their thermal transformation to aromatic species. However, recently we have found that with in-source pyrolysis the occurrence of secondary reactions is reduced significantly. Results from both a selected setof the Argonne Premium Coal Samples and a set of three macerals from the Listen-Stockton coal (APCS 7) are discussed.

Winans, R.E.; Melnikov, P.E.; Dyrkacz, G.R.; Bloomquist, C.A.A. (Argonne National Lab., IL (United States)); Gorbaty, M.L.; Kelemen, S.R.; George, G.N. (Exxon Research and Engineering Co., Annandale, NJ (United States))

1993-01-01

145

Determination of sulfur compounds in coal by mass spectrometry, correlated with XANES and XPS  

SciTech Connect

The objective of this study is to identify important organic sulfur-containing compounds in the Argonne Premium Coals and in selected, separated coal macerals. In-source, desorption/pyrolysis high resolution mass spectrometry is being used to characterize the volatile species of whole coals, macerals, and their extracts. To examine the possibility of secondary reactions and undesirable selectivity, the MS data is compared to data from direct techniques, XANES and XPS. The MS results con-elate very well which supports the suggestion that the species seen are indigenous to the original sample. Therefore, specific structural assignments to the sulfur species can be made. Quantitative speciation of organic sulfur in coals has been accomplished by both XANES and XPS with what appears to be good reliability. Mass spectrometry approaches provide more detailed molecular information, but suffer from problems with sampling. In the past we have found it difficult to isolate aliphatic sulfur compounds by thermal desorption or pyrolysis due to their thermal transformation to aromatic species. However, recently we have found that with in-source pyrolysis the occurrence of secondary reactions is reduced significantly. Results from both a selected setof the Argonne Premium Coal Samples and a set of three macerals from the Listen-Stockton coal (APCS 7) are discussed.

Winans, R.E.; Melnikov, P.E.; Dyrkacz, G.R.; Bloomquist, C.A.A. [Argonne National Lab., IL (United States); Gorbaty, M.L.; Kelemen, S.R.; George, G.N. [Exxon Research and Engineering Co., Annandale, NJ (United States)

1993-03-01

146

Intermediary sulfur compounds in pyrite oxidation: implications for bioleaching and biodepyritization of coal  

Microsoft Academic Search

Accumulation of elemental sulfur during pyrite oxidation lowers the efficiency of coal desulfurization and bioleaching. In\\u000a the case of pyrite bioleaching by Leptospirillum ferrooxidans, an iron(II)-ion-oxidizing organism without sulfur-oxidizing capacity, from the pyritic sulfur moiety about 10% elemental\\u000a sulfur, 2% pentathionate, and 1% tetrathionate accumulated by a recently described cyclic pyrite oxidation mechanism. In the\\u000a case of pure cultures of

A. Schippers; T. Rohwerder; W. Sand

1999-01-01

147

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

Microsoft Academic Search

Microbial leaching is one of the most attractive methods of removing toxic metals from sewage sludge. Sulfuric acid produced by indigenous microflora by the oxidation of elemental sulfur and sulfur compounds solubilizes toxic metals. The oxidation of sulfur compounds can be achieved by the direct oxidation to sulfates or by indirect oxidation, through the production and accumulation of soluble intermediate

R. D. Tyagi; J. F. Blais; L. Deschenes; P. Lafrance; J. P. Villeneuve

1994-01-01

148

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

EPA Science Inventory

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

149

EVALUATION OF TECHNIQUES FOR MEASURING BIOGENIC AIRBORNE SULFUR COMPOUNDS, CEDAR ISLAND FIELD STUDY, 1977  

EPA Science Inventory

Sulfur in both gaseous and particulate form has been measured near biogenic sources using new measurement techniques. The preconcentration of gaseous sulfur on gold-coated glass beads followed by desorption into a flame photometric detection for sulfur is shown to have a detectio...

150

Defluorination of organofluorine sulfur compounds by Pseudomonas sp. strain D2  

SciTech Connect

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

Key, B.D.; Criddle, C.S. [Michigan State Univ., East Lansing, MI (United States)] [Michigan State Univ., East Lansing, MI (United States); Howell, R.D. [3M Environmental Technology and Safety Services, St. Paul, MN (United States)] [3M Environmental Technology and Safety Services, St. Paul, MN (United States)

1998-08-01

151

Sulfur in the atmosphere  

Microsoft Academic Search

In unpolluted areas sulfur occurs primarily in three compounds, SOâ\\/sup 2 -\\/ in aerosols and SOâ and HâS in gas. Sources of SOâ\\/sup 2 -\\/ are the ocean, the soil, and the oxidation of the gaseous compounds. A considerable fraction of the SOâ is of anthropogenic origin. As measurements in polluted and unpolluted areas indicate, most of the HâS seems

C. E. Junge

1960-01-01

152

Sulfur specific chromatography using hydrogenalysis  

SciTech Connect

A totally sulfur specific chromatographic detector is described based on the differential colorimetry of lead acetate tape. Its output is linear with concentration, and has no response to compounds other than sulfur compounds. These characteristics are particularly advantageous when analyzing hydrocarbon gases and light hydrocarbon liquids for low part per million and part per billion concentrations of sulfur compounds. As each particular sulfur species is eluted from a chromatograph column it is mixed with hydrogen and swept into a tube furnace. In the furnace, this sulfur peak is changed into a corresponding hydrogen sulfide peak. The corresponding hydrogen sulfide peak is detected by a lead acetate tape based hydrogen sulfide analyzer. Theory of operation, performance characteristics, and applicability of this type of detector are discussed.

Szinyei, W.J. (Tracor Atlas, Inc., 9441 Baythorne Dr., Houston, TX (US))

1988-01-01

153

Molecular Structure of sulfur  

NSDL National Science Digital Library

The discoverer of sulfur remains anonymous because of lack of records. However, one can trace back to the discovery of R.W. Wood when he used ultra-violet rays to find a sulfur deposit near the crater of Aristarchus on the moon. Sulfur is also found in meteorites. In the United States, Sulfur can be found along the Gulf Coast in wells sunk along salt domes. It is brought to the surface using the Frasch Process in which heated water is forced into the wells and melts the surface. Sulfur may also be found in volcanos or hot springs. Other uses of Sulfur include making phosphatic fertilizers, matches, and medicine. The mineral is a good insulator and takes part in bleaching dried fruit. Sulfur is a minor constitute of body fluids, fats, and skeletal minerals. It can be said that Sulfur is essential to life.

2002-08-26

154

Sulfuric acid poisoning  

MedlinePLUS

Sulfuric acid is a very strong chemical that is corrosive. Corrosive means it can cause severe burns and ... or mucous membranes. This article discusses poisoning from sulfuric acid. This is for information only and not for ...

155

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

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

156

Oxidative and extractive removal of sulfur and nitrogen compounds from in-situ shale oil. Final report  

SciTech Connect

In-situ shale oil was contacted with a gaseous reactant stream containing NO/sub 2/ in an attempt to selectively oxidize the sulfur and nitrogen impurities contained in the oil. The reaction product was then extracted with ethylene diamine (EDA) and water in series to preferentially remove the oxidized sulfur and nitrogen impurities. In-situ shale oil was oxidized by NO/sub 2/ at concentrations of 5 to 30% and space velocities of 1 to 1.65 min/sup -1/. The reaction occurred in a stirred, jacketed, semibatch reactor. Oxidation alone affects some sulfur removal. Oxidative removal of sulfur compounds increased with reaction severity. Thermal treatment of the oxidized samples in an inert atmosphere provided further conversion of sulfur compounds present in the oxidized samples. Substantial coking occurred during thermal treatment. EDA is an effective solvent for extracting sulfur and nitrogen compounds from reacted and unreacted shale oil samples. Oxidation of the shale oil, followed by EDA extraction and water washing provided a modest improvement in sulfur conversion in comparison to extracting and washing the unreacted oil (83% vs 66%). Increasing the reaction severity also boosts sulfur removal, but raffinate yield and nitrogen removal decline significantly. EDA extraction followed by a water wash of unreacted shale oil removed 66% (wt.) of the original sulfur and 40% (wt.) of the original nitrogen. The water wash effectively removes any EDA dissolved in the raffinate. EDA extraction and water washing preceded by reaction did not improve nitrogen removal in comparison to extraction and water washing without oxidation. Oxidation, at the conditions used in this study, did not significantly improve sulfur and nitrogen compound removal in comparison to omitting the reaction when both samples are identically EDA extracted and water washed. 102 refs., 24 figs., 26 tabs.

Sonnett, J.M.

1980-09-01

157

SULFUR POLYMER ENCAPSULATION  

Microsoft Academic Search

Sulfur polymer cement (SPC) is a thermoplastic polymer consisting of 95 wt% elemental sulfur and 5 wt% organic modifiers to enhance long-term durability. SPC was originally developed by the U.S. Bureau of Mines as an alternative to hydraulic cement for construction applications. Previous attempts to use elemental sulfur as a construction material in the chemical industry failed due to premature

2001-01-01

158

The electrooxidation of sulfur-containing compounds at boron-doped diamond electrode  

Microsoft Academic Search

The electrooxidation of homocysteine, glutathione (GSH), 2-mercapto ethanesulfonic acid and cephalexin at boron-doped diamond (BDD) electrodes and glassy carbon (GC) electrodes was investigated by cyclic voltammetry. The oxidation of these sulfur-containing compounds exhibited well-defined irreversible responses. This preliminary study has shown that BDD has better sensitivity than GC. Concentration dependence has been studied and indicated the promise of using BDD

O. Chailapakul; P. Aksharanandana; T. Frelink; Y. Einaga; A. Fujishima

2001-01-01

159

Determination of reduced sulfur compounds in aqueous solutions using gas chromatography flame photometric detection  

Microsoft Academic Search

A method for simultaneous analysis of hydrogen sulfide (HâS), methyl mercaptan (CHâSH), carbon disulfide (CSâ), dimethyl sulfide (DMS, CHâSCHâ), and dimethyl disulfide (DMDS, CHâSSCHâ) in aqueous solutions is described. The reduced sulfur compounds are released from the aqueous sample (50-200 mL) by purging with Nâ and then trapped cryogenically in a U-shaped sample tube with liquid nitrogen. The sample tube

Caroline. Leck; L. E. Baegander

1988-01-01

160

Organic sulfur compounds formed during early diagenesis in Black Sea sediments  

Microsoft Academic Search

Sediments from Units I and II of the Black Sea were analyzed to assess the early diagenetic formation of organic sulfur compounds (OSC). A series of isomeric C28-2,4-dialkylthiophenes was found at low concentrations in surface sediments. OSC with C25-highly branched isoprenoid (RBI) skeletons were not found in surface sediments even though there was a rapid decrease in the concentrations of

Stuart G. Wakeham; Jaap S. Sinninghe Damsté; Math E. L. Kohnen; Jan W. De Leeuw

1995-01-01

161

Mortar damage due to airborne sulfur compounds in a simulation chamber  

Microsoft Academic Search

The interaction between airborne sulfur compounds and mortars has been investigated. Simulation experiments were carried out\\u000a in a flow chamber where temperature, relative humidity and SO2 concentration were controlled. Samples of lime, pozzolan and cement mortars were exposed for 90 days in air with 3 ppm of\\u000a SO2 concentration, at 25°C temperature and 100% relative humidity. Following exposure, the mortar

G. Zappia; C. Sabbioni; M. G. Pauri; G. Gobbi

1994-01-01

162

Regulation of a Novel Acidithiobacillus caldus Gene Cluster Involved in Metabolism of Reduced Inorganic Sulfur Compounds  

Microsoft Academic Search

Acidithiobacillus caldus has been proposed to play a role in the oxidation of reduced inorganic sulfur compounds (RISCs) produced in industrial biomining of sulfidic minerals. Here, we describe the regu- lation of a new cluster containing the gene encoding tetrathionate hydrolase (tetH), a key enzyme in the RISC metabolism of this bacterium. The cluster contains five cotranscribed genes, ISac1, rsrR,

Olena I. Rzhepishevska; Jorge Valdes; Liucija Marcinkeviciene; Camelia Algora Gallardo; Rolandas Meskys; Violaine Bonnefoy; David S. Holmes; Mark Dopson

2007-01-01

163

Au nanoparticles decorated polyaniline nanofiber sensor for detecting volatile sulfur compounds in expired breath  

Microsoft Academic Search

A chemiresistive sensor based on polyaniline (PANI) nanofibers decorated with highly dispersed gold nanopaticles (AuNPs) is developed to detect the volatile sulfur compounds (VSCs) of human expired breath. The PANI nanofibers with a characteristic of horizontal orientation on the insulating gap area of an interdigitated electrode are prepared by a temple-free electrochemical polymerization. The formation of the fine AuNPs on

Chuanjun Liu; Kenshi Hayashi; Kiyoshi Toko

164

Effects of oxidative modification of carbon surface on the adsorption of sulfur compounds in diesel fuel  

Microsoft Academic Search

This work examines the effects of modification of activated carbons (ACs) by HNO3 oxidation and gas-phase O2 oxidation, respectively, on the liquid-phase adsorption of sulfur compounds in diesel fuel. The adsorption characteristics of the oxidized and the original AC samples were evaluated in a fixed-bed flow system by using a model diesel fuel containing 400 parts per million by weight

Anning Zhou; Xiaoliang Ma; Chunshan Song

2009-01-01

165

Removal of sulfur compounds from utility pipelined synthetic natural gas using modified activated carbons  

Microsoft Academic Search

Synthetic natural gas (SNG), which is produced from petroleum and distributed via pipeline in Honolulu by The Gas Company, was analyzed using a gas chromatograph equipped with a sulfur chemiluminescence detector (GC\\/SCD). Hydrogen sulfide (H2S), methyl mercaptan (MM), ethyl mercaptan (EM), dimethylsulfide (DMS), dimethyl disulfide (DMDS), tetrahydrothiophene (THT), ethyl disulfide (EDS), and one unidentified compound (UN1) were detected. Among these

Hong Cui; Scott Q. Turn; Mark A. Reese

2009-01-01

166

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

Microsoft Academic Search

Volatile sulfur compounds (VSCs) are a major class of chemicals associated with odor from animal feeding operations (AFOs). Identifying and quantifying VSCs in air is challenging due to their volatility, reactivity, and low concentrations. In the present study, a canister-based method collected whole air in fused silica-lined (FSL) mini-canister (1.4L) following passage through a calcium chloride drying tube. Sampled air

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

2008-01-01

167

Volatile Reduced Sulfur Compounds: Detection and Quantification in a Stratified Freshwater Lake  

NASA Astrophysics Data System (ADS)

It is now generally recognized that volatile reduced sulfur compounds (VRSCs), including hydrogen sulfide (H2S), carbon disulfide (CS2), methyl sulfide (MS), dimethyl sulfide (DMS), and dimethyl disulfide (DMDS) are significant constituents for atmospheric sulfur. Therefore, they play an important role in large-scale sulfur cycling. To date these compounds have been thoroughly investigated and quantified in open oceans and coastal marine environments. Additionally the export of VRSCs from marine surface waters to the atmosphere may implicate these compounds in global climate regulation. While current literature focuses on the biogeochemistry of VRSCs in marine systems, a comprehensive understanding of the global biogeochemistry of VRSCs necessitates more rigorous studies in freshwater environments. We will present concentration profiles of VRSCs in Linsley Pond, a stratified freshwater lake in Branford, CT. We developed an extremely sensitive methods for VSRCS measurements that relies on a purge-trap system coupled to gas chromatography with a pulsed flame photometric detector (PFPD). Using this method, we sampled Linsley Pond weekly to bimonthly during the initial stages of stratification in the spring and during mixing in the fall. Influence of the oxidation/reduction potential in the aquatic environment on the distribution of VRSCs over the complete water column and possible sources of VRSCs were also investigated.

Mylon, S. E.; Hu, H.; Benoit, G.

2003-12-01

168

Sulfur cycle in buried evaporites  

NASA Astrophysics Data System (ADS)

Sulfur isotopes are potent indicators of the way in which sulfur behaves chemically during diagenesis. We have studied sulfur isotope ratios (34S/32S) from a number of minerals and compounds across the Permian-Triassic boundary in the Khuff Formation, Abu Dhabi. The ?34S in dissolved marine sulfate increased by 10‰ from the Late Permian to the Early Triassic. Despite precipitation of gypsum from Permian and Triassic seawater and its subsequent dehydration to anhydrite at depths greater than about 1000 m, the primary marine stratigraphic sulfur isotope variation has been preserved in anhydrite in the Khuff Formation. A combination of biostratigraphic and absolute age data show that this 10‰ shift occurred over <2 m.y. Gypsum dehydration to anhydrite has not involved significant isotopic fractionation or diagenetic redistribution of material in the subsurface. The sulfur isotope variation across the Permian-Triassic boundary is also present in elemental sulfur and H2S, at depths greater than 4300 m, formed by reaction of anhydrite with hydrocarbons via thermochemical sulfate reduction. This demonstrates that sulfate reduction has not led to isotope fractionation. It also demonstrates that significant mass transfer has not occurred, at least in the vicinity of the Permian-Triassic boundary, even though elemental sulfur and H2S are both fluid phases at depths greater than 4300 m. Thus, despite two major diagenetic processes that converted the sulfur in gypsum into elemental sulfur and H2S by 4300 m burial and the potentially mobile nature of some of the reaction products, the primary differences in sulfur isotopes have been preserved in the rocks and fluids. All reactions occurred in situ; there was no significant sulfur isotope fractionation, and only negligible sulfur was added, subtracted, or moved internally within the system.

Worden, R. H.; Smalley, P. C.; Fallick, A. E.

1997-07-01

169

Sulfur tolerant anode materials  

SciTech Connect

The goal of this program is the development of a molten carbonate fuel cell (MCFC) anode which is more tolerant of sulfur contaminants in the fuel than the current state-of-the-art nickel-based anode structures. This program addresses two different but related aspects of the sulfur contamination problem. The primary aspect is concerned with the development of a sulfur tolerant electrocatalyst for the fuel oxidation reaction. A secondary issue is the development of a sulfur tolerant water-gas-shift reaction catalyst and an investigation of potential steam reforming catalysts which also have some sulfur tolerant capabilities. These two aspects are being addressed as two separate tasks.

Not Available

1988-05-01

170

Sulfur tolerant anode materials  

SciTech Connect

The goal of this program is the development of a molten carbonate fuel cell (MCFC) anode which is more tolerant of sulfur contaminants in the fuel than the current state-of-the-art nickel-based anode structures. This program addresses two different but related aspects of the sulfur contamination problem. The primary aspect is concerned with the development of a sulfur tolerant electrocatalyst for the fuel oxidation reaction. A secondary issue is the development of a sulfur tolerant water-gas-shift reaction catalyst and an investigation of potential steam reforming catalysts which also have some sulfur tolerant capabilities. These two aspects are being addressed as two separate tasks.

Not Available

1987-02-01

171

Seasonal changes in fluxes of methane and volatile sulfur compounds from rice paddies and their concentrations in soil water  

Microsoft Academic Search

Rice paddies emit not only methane but also several volatile sulfur compounds such as dimethyl sulfide (DMS: CH3SCH3). However, little is known about DMS emission from rice paddies. Fluxes of methane and DMS, and the concentrations of methane and several volatile sulfur compounds including hydrogen sulfide (H2S), carbonyl disulfide (CS2), methyl mercaptan (CH3SH) and DMS in soil water and flood

Isamu Nouchi; Tatsuo Hosono; Kaori Sasaki

1997-01-01

172

Sulfur rate control system  

SciTech Connect

A sulfur rate control system is described for substantially optimizing particulate removal performance of an electrostatic precipitator in fluid communication with a flue carrying combustion products of a fossil fuel, comprising: an electrostatic precipitator having an inlet for receiving a flue gas: means for injecting sulfur trioxide into a flue for mixing with said flue gas at a location preceding entry of said flue gas into said electrostatic precipitator, said injection of sulfur trioxide being varied responsive to a proportional control signal; and, control means coupled to both said flue and said sulfur trioxide injection means for generating said proportional control signal, said control means including (1) means for measuring a sulfur dioxide concentration quantity in said flue gas at a location preceding said sulfur trioxide injection means, (2) means for measuring a flow rate of particulates in said flue gas at a location preceding said sulfur trioxide injection means, and (3) a controller for calculating a ratio between said sulfur dioxide concentration quantity and said flow rate of particulates, said ratio calculating controller having a first input coupled to said sulfur dioxide measuring means and a second input coupled to said particulate flow rate measuring means for generating said proportional control signal in proportion to a difference between a predetermined value and said ratio between said sulfur dioxide concentration quantity and said flow rate of particulates, said ratio controller having an output coupled to said sulfur trioxide injection means for maximizing particulate removal efficiency of said electrostatic precipitator.

Bell, T.A.; Mullendore, M.G.; Kleinfeldt, T.E.; Walker, H.G. Jr.

1993-07-20

173

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

PubMed

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

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

2008-03-01

174

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

PubMed

Sulfuricurvum kujiense Kodama and Watanabe 2004 is the type species of the monotypic genus Sulfuricurvum, which belongs to the family Helicobacteraceae in the class Epsilonproteobacteria. The species is of interest because it is frequently found in crude oil and oil sands where it utilizes various reduced sulfur compounds such as elemental sulfur, sulfide and thiosulfate as electron donors. Members of the species do not utilize sugars, organic acids or hydrocarbons as carbon and energy sources. This genome sequence represents the type strain of the only species in the genus Sulfuricurvum. The genome, which consists of a circular chromosome of 2,574,824 bp length and four plasmids of 118,585 bp, 71,513 bp, 51,014 bp, and 3,421 bp length, respectively, harboring a total of 2,879 protein-coding and 61 RNA genes and is a part of the Genomic Encyclopedia of Bacteria and Archaea project. PMID:22675602

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

2012-03-19

175

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

SciTech Connect

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

Han, Cliff [Los Alamos National Laboratory (LANL); Kotsyurbenko, Oleg [Technical University of Braunschweig; Chertkov, Olga [Los Alamos National Laboratory (LANL); Held, Brittany [Los Alamos National Laboratory (LANL); Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Hammon, Nancy [U.S. Department of Energy, Joint Genome Institute; Deshpande, Shweta [U.S. Department of Energy, Joint Genome Institute; Cheng, Jan-Fang [U.S. Department of Energy, Joint Genome Institute; Tapia, Roxanne [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Liolios, Konstantinos [U.S. Department of Energy, Joint Genome Institute; Pagani, Ioanna [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Chen, Amy [U.S. Department of Energy, Joint Genome Institute; Palaniappan, Krishna [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Chang, Yun-Juan [ORNL; Jeffries, Cynthia [Oak Ridge National Laboratory (ORNL); Brambilla, Evelyne-Marie [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Rohde, Manfred [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Spring, Stefan [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Sikorski, Johannes [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Eisen, Jonathan [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Hugenholtz, Philip [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute

2012-01-01

176

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

PubMed

Oxidation of Hg(0) with any oxidant or converting itto a particle-bound form can facilitate its removal. Two sulfur-chlorine compounds, sulfur dichloride (SCl2) and sulfur monochloride (S2Cl2), were investigated as oxidants for Hg(0) by gas-phase reaction and by surface-involved reactions in the presence of flyash or activated carbon. The gas-phase reaction between Hg(0) and SCl2 is shown to be more rapid than the gas-phase reaction with chlorine, and the second order rate constant was 9.1 (+/- 0.5) x 10(-18) mL-molecules(-1) x s(-1) at 373 K. The presence of flyash or powdered activated carbon in flue gas can substantially accelerate the reaction. The predicted Hg(0) removal is about 90% with 5 ppm SCl2 or S2Cl2 and 40 g/m3 of flyash in flue gas. The combination of activated carbon and sulfur-chlorine compounds is an effective alternative. We estimate that coinjection of 3-5 ppm of SCl2 (or S2Cl2) with 2-3 Lb/MMacf of untreated Darco-KB is comparable in efficiency to the injection of 2-3 Lb/MMacf Darco-Hg-LH. Extrapolation of kinetic results also indicates that 90% of Hg(0) can be removed if 3 Lb/MMacf of Darco-KB pretreated with 3% of SCl2 or S2Cl2 is used. Mercuric sulfide was identified as one of the principal products of the Hg(0)/SCl2 or Hg(0)/S2Cl2 reactions. Additionally, about 8% of SCl2 or S2Cl2 in aqueous solutions is converted to sulfide ions, which would precipitate mercuric ion from FGD solution. PMID:19708374

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

2009-07-15

177

Molecular Structure of Sulfuric Acid  

NSDL National Science Digital Library

H2SO4 was discovered by alchemists and made from heating a compound of iron sulfate. In 1740, sulfuric acid was produced for commercial sale. Sulfuric acid is a very strong acid which is used in car batteries. The acid disassociates in water to give two protons and sulfate. This acid can destroy flesh and cause blindness. It was discovered in the 19th century that adding sulfuric acid to soil produces phosphorus, which is beneficial to plants; hence, sulfuric acid is used as a fertilizer in the form of super phosphate and ammonium sulfate. Sulfuric acid is also used to refine petroleum and process metals, and is found in paints and car batteries.

2002-08-15

178

Microbial degradation of nitrogen, oxygen, and sulfur heterocyclic compounds under anaerobic conditions: Studies with aquifer samples  

SciTech Connect

The potential for anaerobic biodegradation of 12 heterocyclic model compounds was studied. Nine of the model compounds were biotransformed in aquifer slurries under sulfate-reducing or methanogenic conditions. The nitrogen and oxygen heterocyclic compounds were more susceptible to anaerobic biodegradation than those compounds containing a sulfur deteroatom. In contrast, only small amounts of methane were detected in aquifer slurries amended with compounds containing an oxygen heteroatom, even though a decrease in the parent substrate concentration occurred. Pyridine, 2-picoline and 4-picoline were biotransformed within three months under sulfate-reducing conditions. However, longer incubation times were required for the degradation of these substrates in methanogenic aquifer slurries. A literature survey reveals the widespread contamination of ground waters with heterocyclic compounds from waste management practice and fossil-fuel-related industries.

Kuhn, E.P.; Suflita, J.M.

1989-01-01

179

The sulfur cycle.  

PubMed

Even granting our uncertainties about parts of our model of the sulfur cycle, we can draw some conclusions from it: 1) Man is now contributing about one half as much as nature to the total atmospheric burden of sulfur compounds, but by A.D. 2000 he will be contributing about as much, and in the Northern Hemisphere alone he will be more than matching nature. 2) In industrialized regions he is overwhelming natural processes, and the removal processes are slow enough (several days, at least) so that the increased concentration is marked for hundreds to thousands of kilometers downwind. 3) Our main areas of uncertainty, and ones that demand immediate attention because of their importance to the regional air pollution question, are: (i) the rates of conversion of H(2)S and SO(2) to sulfate particles in polluted as well as unpolluted atmospheres; (ii) the efficiency of removal of sulfur compounds by precipitation in polluted air. And for a better understanding of the global model we need to know: (i) the amount of biogenic H(2)S that enters the atmosphere over the continents and coastal areas; (ii) means of distinguishing man-made and biogenic contributions to excess sulfate in air and precipitation; (iii) the volcanic production of sulfur compounds, and their influence on the particle concentration in the stratosphere; (iv) the large-scale atmospheric circulation patterns that exchange air between stratosphere and troposphere (although absolute amounts of sulfate particles involved are small relative to the lower tropospheric burden); (v) the role of the oceans as sources or sinks for SO(2). PMID:5009760

Kellogg, W W; Cadle, R D; Allen, E R; Lazrus, A L; Martell, E A

1972-02-11

180

Selective oxidations of organosulfur model compounds and coal for the removal of organic sulfur  

SciTech Connect

Investigations with organosulfur compounds have established that potassium monopersulfate (Oxone) in aqueous ethanol and sodium perborate in glacial acetic acid are highly selective oxidants for the oxidation of organic sum ides and aromatic sulfur heterocycles to their corresponding sulfoxides and sulfones. In a series of selective oxidations, dibenzothiophene in ethanol, fluorene in ethanol, and a 50:50 mol mixture of dibenzothiophene (DBT) and fluoresce in ethanol were reacted with aqueous Oxone under mild conditions. Capillary gas chromatographic analyses showed conversions of DBT to DBT-5,5-dioxide, while its carbon analog, fluorene was recovered quantitatively in every case. Furthermore, selective oxidations with Oxone of a triboelectrostatically cleaned Illinois {number sign}6 ultrafine coal (400 mesh {times} 0) and an Illinois {number sign}6 coal (IBC-101) (200 mesh {times} 0) depyritized via microorganisms were investigated. X-ray photoelectron spectroscopic (XPS) data indicated oxidation of a large fraction of the organic sulfur on the coal surface. Approximately 55--85% of the total S 2p area could be attributed to oxidized organic sulfur in the form of sulfones.

Fauth, D.J.; Baltrus, J.P.; Nowak, M.A.; Olson, G.J.

1991-01-01

181

Reactivity of a condensed–type lignin model compound in the Mannich reaction and preparation of cationic surfactant from sulfuric acid lignin  

Microsoft Academic Search

The chemical conversion of phenolized sulfuric acid lignin (P-SAL), prepared from sulfuric acid lignin (SAL) by phenolation\\u000a with sulfuric acid catalyst, to novel cationic surfactant was investigated. To elucidate the chemical reactivity of the P-SAL\\u000a to a Mannich reaction, 1-guaiacyl-1-p-hydroxyphenylethane (I) as a simple phenolized sulfuric acid lignin model compound was reacted with dimethylamine and formaldehyde. Quantitative\\u000a analysis of the

Yasuyuki Matsushita; Seiichi Yasuda

2003-01-01

182

Sulfur 1s near edge x-ray absorption fine structure spectroscopy of thiophenic and aromatic thioether compounds.  

PubMed

Thiophenic compounds are major constituents of fossil fuels and pose problems for fuel refinement. The quantification and speciation of these compounds is of great interest in different areas such as biology, fossil fuels studies, geology, and archaeology. Sulfur 1s Near-Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy has emerged as a qualitative and quantitative method for sulfur speciation. A firm understanding of the sulfur 1s NEXAFS spectra of organosulfur species is required for these analytical studies. To support this development, the sulfur 1s NEXAFS spectra of simple thiols and thioethers were previously examined, and are now extended to studies of thiophenic and aromatic thioether compounds, in the gas and condensed phases. High-resolution spectra have been further analyzed with the aid of Improved Virtual Orbital (IVO) and ?(self-consistent field) ab initio calculations. Experimental sulfur 1s NEXAFS spectra show fine features predicted by calculation, and the combination of experiment and calculation has been used to improve the assignment of spectroscopic features important for the speciation and quantification of sulfur compounds. Systematic differences between gas and condensed phases are also explored; these differences suggest a significant role for conformational effects in the NEXAFS spectra of condensed species. PMID:23758366

Behyan, Shirin; Hu, Yongfeng; Urquhart, Stephen G

2013-06-01

183

Sulfur 1s near edge x-ray absorption fine structure spectroscopy of thiophenic and aromatic thioether compounds  

NASA Astrophysics Data System (ADS)

Thiophenic compounds are major constituents of fossil fuels and pose problems for fuel refinement. The quantification and speciation of these compounds is of great interest in different areas such as biology, fossil fuels studies, geology, and archaeology. Sulfur 1s Near-Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy has emerged as a qualitative and quantitative method for sulfur speciation. A firm understanding of the sulfur 1s NEXAFS spectra of organosulfur species is required for these analytical studies. To support this development, the sulfur 1s NEXAFS spectra of simple thiols and thioethers were previously examined, and are now extended to studies of thiophenic and aromatic thioether compounds, in the gas and condensed phases. High-resolution spectra have been further analyzed with the aid of Improved Virtual Orbital (IVO) and ?(self-consistent field) ab initio calculations. Experimental sulfur 1s NEXAFS spectra show fine features predicted by calculation, and the combination of experiment and calculation has been used to improve the assignment of spectroscopic features important for the speciation and quantification of sulfur compounds. Systematic differences between gas and condensed phases are also explored; these differences suggest a significant role for conformational effects in the NEXAFS spectra of condensed species.

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

2013-06-01

184

Topsoe`s Wet gas Sulfuric Acid (WSA) process: An alternative technology for recovering refinery sulfur  

Microsoft Academic Search

The Topsoe Wet gas Sulfuric Acid (WSA) process is a catalytic process which produces concentrated sulfuric acid from refinery streams containing sulfur compounds such as HâS (Claus plant feed), Claus plant tail gas, SOâ (FCC off-gas, power plants), and spent sulfuric acid (alkylation acid). The WSA process recovers up to 99.97% of the sulfur value in the stream as concentrated

1995-01-01

185

On-line sulfur analysis  

SciTech Connect

Field gas processing plants take great care to remove sulfur compounds from the gas coming in through the gathering system to reduce the toxicity and corrosivity of the gas. Then, at key points along the transportation and distribution networks, sulfur-based odorant compounds are added to the gas for safety and to comply with governmental regulations. As a result, a wide range of sulfides may be present in the gas stream, presenting a difficult measurement and separation task for even well-equipped laboratories. Field requirements are even more demanding of time and instrument reliability. Specificity in sulfur compound analysis is becoming more and more important, transcending the traditional ''grains of sulfur per cubit ft'' and, in some instances, regulatory requirements.

Not Available

1988-02-01

186

Isotopically labeled sulfur compounds and synthetic selenium and tellurium analogues to study sulfur metabolism in marine bacteria  

PubMed Central

Summary Members of the marine Roseobacter clade can degrade dimethylsulfoniopropionate (DMSP) via competing pathways releasing either methanethiol (MeSH) or dimethyl sulfide (DMS). Deuterium-labeled [2H6]DMSP and the synthetic DMSP analogue dimethyltelluriopropionate (DMTeP) were used in feeding experiments with the Roseobacter clade members Phaeobacter gallaeciensis DSM 17395 and Ruegeria pomeroyi DSS-3, and their volatile metabolites were analyzed by closed-loop stripping and solid-phase microextraction coupled to GC–MS. Feeding experiments with [2H6]DMSP resulted in the incorporation of a deuterium label into MeSH and DMS. Knockout of relevant genes from the known DMSP demethylation pathway to MeSH showed in both species a residual production of [2H3]MeSH, suggesting that a second demethylation pathway is active. The role of DMSP degradation pathways for MeSH and DMS formation was further investigated by using the synthetic analogue DMTeP as a probe in feeding experiments with the wild-type strain and knockout mutants. Feeding of DMTeP to the R. pomeroyi knockout mutant resulted in a diminished, but not abolished production of demethylation pathway products. These results further corroborated the proposed second demethylation activity in R. pomeroyi. Isotopically labeled [2H3]methionine and 34SO4 2?, synthesized from elemental 34S8, were tested to identify alternative sulfur sources besides DMSP for the MeSH production in P. gallaeciensis. Methionine proved to be a viable sulfur source for the MeSH volatiles, whereas incorporation of labeling from sulfate was not observed. Moreover, the utilization of selenite and selenate salts by marine alphaproteobacteria for the production of methylated selenium volatiles was explored and resulted in the production of numerous methaneselenol-derived volatiles via reduction and methylation. The pathway of selenate/selenite reduction, however, proved to be strictly separated from sulfate reduction.

Brock, Nelson L; Citron, Christian A; Zell, Claudia; Berger, Martine; Wagner-Dobler, Irene; Petersen, Jorn; Brinkhoff, Thorsten; Simon, Meinhard

2013-01-01

187

Anaerobic oxidation of thiosulfate and elemental sulfur in Thiobacillus denitrificans  

Microsoft Academic Search

Thiobacillus denitrificans strain RT could be grown anaerobically in batch culture on thiosulfate but not on other reduced sulfur compounds like sulfide, elemental sulfur, thiocyanate, polythionates or sulfite. During growth on thiosulfate the assimilated cell sulfur was derived totally from the outer or sulfane sulfur. Thiosulfate oxidation started with a rhodanese type cleavage between sulfane and sulfone sulfur leading to

Michael Schedel; Hans G. Trtiper

1980-01-01

188

Lunar Sulfur Capture System  

NASA Technical Reports Server (NTRS)

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

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

2013-01-01

189

Io - Geochemistry of sulfur  

NASA Astrophysics Data System (ADS)

The evidence from Voyager imaging, Earth-based spectral reflectivity studies, and thermal emission measurements combine to suggest an extremely fresh, volcanically recycled sulfur-rich crust for Io, with very shallow large-scale melting. Two present styles of volcanism are possible, depending on the thickness of local deposits of sulfur: shallow liquid sulfur magma generation with quiescent flooding, and high-temperature volcanism with violet eruption of a sulfur-iron magma driven by SO2. Evolutionary considerations preclude direct derivation of Io's lithosphere from any metal-bearing chondritic source material. Metal-free C3V- or C2M-type parent material of either primary or secondary origin is the most plausible direct antecedent of the present sulfur-rich crust. Sulfates are almost certainly important constituents of the mantle, and can participate in the recycling of reduced, dense sulfide species to prevent total extraction of sulfur into the core.

Lewis, J. S.

1982-04-01

190

The global sulfur cycle  

NASA Technical Reports Server (NTRS)

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

Sagan, D. (editor)

1985-01-01

191

Molecular characterization of nitrogen and sulfur containing compounds in night-time SOA  

NASA Astrophysics Data System (ADS)

The oxidation of volatile organic compounds (VOCs) leads to the formation of low volatile organic compounds that can form secondary organic aerosol (SOA). Studies in the past showed that laboratory generated and ambient SOA are made of polar molecules with O/C ratios generally greater than 0.5. More recent studies have shown that SOA compounds can contain heteroatoms mainly sulfur and nitrogen atoms. Offline chemical analysis with high-resolution mass spectrometers and fragmentation experiments has shown that sulphur containing compounds are mainly organosulfates and nitrogen containing species are aromatic heterocyclic compounds such as imidazole and nitrated aromatic compounds such as nitrophenols. In addition to these, SOA compounds containing both sulfur and nitrogen have been reported from the analysis of ambient organic aerosol, rainwater, fog and cloud samples. Based on the mass spectrometric evidence these compounds are attributed to nitrooxy-organosulfates originating from isoprene and monoterpenes. Although these compounds are ubiquitously detected in the ambient samples, reports about their detection in laboratory generated SOA are scares and their formation mechanisms are not well understood. In the present study, we investigated the formation of sulfur and nitrogen containing SOA species in the oxidation of biogenic VOCs. Photooxidation and night-time oxidation experiments were performed in a smog chamber to produce SOA samples. The laboratory generated SOA samples were analysed with UPLC-IMS-TOFMS (Ultra Performance Liquid Chromatography coupled to Ion Mobility Spectrometry and Time of Flight Mass Spectrometry). The presence of highly acidic sulphate seed particles (pH0) did not promote the formation of compounds with chemical formula of C10H17NO7S- and m/z value of 294.0653, indicating that the formation mechanisms of these compounds unlikely involve the ring opening reactions of epoxides and subsequent sulfation reactions. On the other hand, their formation was significantly enhanced when the night-time oxidation was performed in the presence of both neutral seed particle and gas-phase SO2, suggesting that the presence of gas-phase SO2 is a key for their formation.

Iinuma, Yoshiteru; Mutzel, Anke; Rodigast, Maria; Böge, Olaf; Herrmann, Hartmut

2014-05-01

192

Effect of sulfur-containing compounds on anaerobic degradation of cellulose to methane by mixed cultures obtained from sewage sludge.  

PubMed Central

Tests were made to determine the effects of inorganic and organic sulfur sources on the degradation of cellulose to methane in a chemically defined medium with sulfur-poor inoculum prepared from sewage sludge. The results show that a sulfur source of about a 0.85 mM concentration is essential for the degradation of cellulose to CH4. However, the production of CH4 from CO2 and H2 provided in the headspace occurred with 0.1 mM sulfate or sulfide. At a 9 mM concentration, all inorganic sulfur compounds other than sulfate inhibited both cellulose degradation and methane formation, and this inhibition increased in the order thiosulfate less than sulfite less than sulfide less than H2S. It appears that the degradation of cellulose to CH4 in a sulfate-free medium by inoculum maintained in a low-sulfur medium is inhibited because of the lack of availability of sulfur for growth of bacteria and synthesis of cell materials and sulfur-containing cofactors involved in cellulose degradation and methanogenesis. The reduction of methanogenesis by higher levels of sulfate probably occurs as a result of stimulation of reactions converting acetate and H2 to end products other than CH4.

Khan, A W; Trottier, T M

1978-01-01

193

Development of Techniques of Production of Sulfur-35 and Its Inorganic Compounds.  

National Technical Information Service (NTIS)

Techniques to produce routinely Curies of carrier-free sulfur-35 from neutron irradiated potassium chloride were developed. Firstly the ratio of sulfur-35 to phosphorus-32 produced respectively by the reactions exp 35 Cl(n,p) exp 35 S and exp 35 Cl(n, alp...

E. Shikata

1981-01-01

194

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

PubMed Central

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

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

2013-01-01

195

Determination of reduced sulfur compounds in aqueous solutions using gas chromatography flame photometric detection  

SciTech Connect

A method for simultaneous analysis of hydrogen sulfide (H/sub 2/S), methyl mercaptan (CH/sub 3/SH), carbon disulfide (CS/sub 2/), dimethyl sulfide (DMS, CH/sub 3/SCH/sub 3/), and dimethyl disulfide (DMDS, CH/sub 3/SSCH/sub 3/) in aqueous solutions is described. The reduced sulfur compounds are released from the aqueous sample (50-200 mL) by purging with N/sub 2/ and then trapped cryogenically in a U-shaped sample tube with liquid nitrogen. The sample tube was sealed with end caps and placed in a portable freezer. Under stable conditions in the laboratory, the sulfur compounds are released by controlled heating and injected onto packed column gas chromatograph with a flame photometric detector. The precision of the method for environmental samples was better than +/- 5% for all compounds except for H/sub 2/S, for which the precision was +/- 25%. The detection limits for H/sub 2/S, CH/sub 3/SH, CS/sub 2/, DMS, and DMDS were 1, 0.6, 0.2, 0.2, and 0.4 ng x L/sup -1/ S, respectively, in a 200-mL natural sample. Analyses of environmental samples have been successfully performed with the described method.

Leck, C.; Baegander, L.E.

1988-09-01

196

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

NASA Astrophysics Data System (ADS)

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

Puxbaum, H.; König, G.

197

ADVANCED SULFUR CONTROL CONCEPTS  

SciTech Connect

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).

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

2003-01-01

198

Enhancement of selectivity for preferential CO oxidation over SO 2-pretreated Ru\\/Al 2O 3 catalyst by the presence of sulfur compounds  

Microsoft Academic Search

The preferential CO oxidation on a monolith Ru\\/Al2O3 catalyst pretreated with SO2 in the reactant gas was investigated in the presence\\/absence of 0.21–20ppm sulfur compounds (SO2 or H2S). In the presence of 2.1ppm sulfur compound, CO was preferentially oxidized over the SO2-pretreated catalyst at 150°C. On the other hand, in the absence of sulfur compounds, the H2 oxidation was promoted.

Hidenobu Wakita; Tatsuya Takeguchi; Wataru Ueda

2007-01-01

199

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

SciTech Connect

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

Nai-Qiang Yan; Zan Qu; Yao Chi; Shao-Hua Qiao; Ray L. Dod; Shih-Ger Chang; Charles Miller [University of California, Berkeley, CA (United States). Environmental Energy Technology Division

2009-07-15

200

Elemental sulfur recovery process  

DOEpatents

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

Flytzani-Stephanopoulos, M.; Zhicheng Hu.

1993-09-07

201

Elemental sulfur recovery process  

DOEpatents

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

Flytzani-Stephanopoulos, Maria (Winchester, MA); Hu, Zhicheng (Somerville, MA)

1993-01-01

202

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

NASA Astrophysics Data System (ADS)

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

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

203

Regional river sulfur runoff  

SciTech Connect

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

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

1985-01-20

204

Electroanalytical chemistry of sulfur compounds for the new coal conversion technologies  

SciTech Connect

Polarographic methods are described tailor-made for the speciation and determination of sulfur contaminants in synfuels and coal gasification/liquefaction process streams. In samples containing the anions, S{sub x}{sup 2{minus}}, sulfidic sulfur was quantitated by anodic depolarization of the dropping mercury electrode, while polysulfidic sulfur was determined with the aid of an electroreduction process implicating 2(x-1) electrons. Polythionates were electroreduced to thiosulfate, sulfite, sulfide and/or mixtures thereof, under judiciously controlled experimental conditions. Thiosulfate and sulfite were quantitated by differential pulse polarography at dropping mercury anodes via reactions involving formation of thiosulfato- and sulfitomercurates. 14 refs., 2 figs.

Jordan, J. (Pennsylvania State Univ., University Park (USA)); Talbott, J. (Med-Chek Labs., Pittsburgh, PA (USA)); Yakupkovic, J. (Union Camp Corp., Princeton, NJ (USA))

1989-06-01

205

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

PubMed

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

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

2005-02-01

206

A Multipurpose Sampling Loop for Analysis of Nanogram to Milligram per Cubic Meter Levels of Sulfur Compounds in the Atmosphere, Natural Gas and Gaseous Fuels  

Microsoft Academic Search

A multipurpose sampling loop coupled with a GC-sulfur chemiluminescence detector (SCD) for analysis of nanogram per cubic meter to milligram per cubic meter levels of sulfur compounds in the atmosphere, natural gas and gaseous fuels is reported in this paper. Samples with higher concentrations of sulfur compounds (> 70 ?g\\/m) can be introduced to the GC-SCD by the sampling loop

H. Tang; P. Heaton; M. Hadley

1996-01-01

207

Thermophilic Biodesulfurization of Various Heterocyclic Sulfur Compounds and Crude Straight-Run Light Gas Oil Fraction by a Newly Isolated Strain Mycobacterium phlei WU0103  

Microsoft Academic Search

Various heterocyclic sulfur compounds such as naphtho[2,1- b]thiophene (NTH) and benzo[ b]thiophene (BTH) derivatives can be detected in diesel oil, in addition to dibenzothiophene (DBT) derivatives. Mycobacterium phlei WU-0103 was newly isolated as a bacterial strain capable of growing in a medium with NTH as the sulfur source at 50°C. M. phlei WU-0103 could degrade various heterocyclic sulfur compounds, not

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

2005-01-01

208

Electronic structures and conformational stabilities of some organo-sulfur compounds  

NASA Astrophysics Data System (ADS)

Ab initio calculations were carried out for some organo-sulfur molecules using STO-3G and 4-31G bases, and a general basis which includes d-orbitals (D) in the sulfur atom. In order to make a comparison between the results of ab initio and semi-empirical procedures, the calculations were also carried out by the CNDO/2 ( spd') procedure. The exponent ? value of the d-orbitals for the sulfur atom was optimized using the molecule HSCH 2SH. From these calculations very useful information was obtained about the rotational isomerism of these molecules. The 4-31G and D bases reproduced the experimental conformational stability of molecules with two sulfur atoms, but the STG-3G basis was unsuitable.

Ohsaku, Masaru; Murata, Hiromu

209

Polysulfide Sealant Compositions. 2. Interactions between Elemental Sulfur and Organosulfur Compounds. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

Added sulfur in polysulfide aircraft sealants can become chemically bound to the polymer backbone. The chemical processes involved, and their effect on thermal performance of the resulting sealants, have been examined. Reactions of aliphatic thiols with s...

P. J. Hanhela R. J. Hook D. B. Paul

1994-01-01

210

Sulfur volcanoes on Io?  

NASA Technical Reports Server (NTRS)

The unusual rheological properties of sulfur are discussed in order to determine the distinctive volcanic flow morphologies which indicate the presence of sulfur volcanoes on the Saturnian satellite Io. An analysis of high resolution Voyager imagery reveals three features which are considered to be possible sulfur volcanoes: Atar Patera, Daedalus Patera, and Kibero Patera. All three features are distinguished by circular-to-oval central masses surrounded by irregular widespread flows. The central zones of the features are interpreted to be domes formed of high temperature sulfur. To confirm the interpretations of the satellite data, molten sulfur was extruded in the laboratory at a temperature of 210 C on a flat surface sloping 0.5 deg to the left. At this temperature, the sulfur formed a viscous domelike mass over the event. As parts of the mass cooled to 170 C the viscosity decreased to a runny stage, forming breakout flows. It is concluded that a case can be made for sulfur volcanoes on Io sufficient to warrant further study, and it is recommended that the upcoming Galileo mission examine these phenomena.

Greeley, R.; Fink, J. H.

1984-01-01

211

Evaluation of Occupational Exposure to Sulfur Compounds in Paper Pulp Kraft Mills  

Microsoft Academic Search

A study was carried out to provide a comprehensive profile of sulfur gas concentrations to which workers are exposed during the manufacture of paper pulp by the kraft process. Methods currently available—including colorimetric tubes, direct-reading monitors, and gas chromatographic methods—were compared. Gas chromatography is the only technique able to reliably measure individual sulfur gases. However, the necessity of using a

NICOLE GOYER

1990-01-01

212

Interactions of sulfur-containing compounds with transition metal clusters and metal surfaces III  

Microsoft Academic Search

Reactions of sulfur-containing substituted dibenzothiophenes with transition metals have been continued with emphasis on the nature and type of metal-sulfur bonding, including the effect of the metal on the adjacent bond lengths. The structure of (η⁵-cyclopentadienyl) carbonyl 4-P-diphenyl-phosphine dibenzothiophene iron (II) iodide has been determined by x-ray diffraction. The synthesis of μ2 bridged dinuclear Fe(II) complex with 4-thiomethyldibenzothiophene is reported.

L. V. Dunkerton; C. C. Hinckley; J. Tyrrell; P. D. Robinson

1989-01-01

213

An innovative approach for removing COâ and sulfur compounds from a gas stream  

Microsoft Academic Search

A major U.S. refiner has chosen MERICHEM Company's Process Technology Division, Houston, Texas, to perform process and mechanical design and frabrication services for treating a 12.86 MM SCFD FCCU fuel gas stream for removal of HâS, COâ, and mercaptan sulfur. The treated gas will be sold to a utility company, and it must meet a total sulfur specification. This unit

Wizig

1985-01-01

214

The influence of hydroxyl volatile organic compounds on the oxidation of aqueous sulfur dioxide by oxygen.  

PubMed

Although the effect of volatile organic compounds (VOCs) on the oxidation of dissolved sulfur dioxide by oxygen has been the subject of many investigations, this is the first study which examines the effect of a large number of precisely 16 hydroxy compounds. The kinetics both in the absence and the presence of VOCs was defined by rate laws (A and B):[Formula: see text] [Formula: see text]where R o and k o are the initial rate and first-order rate constant, respectively, in the absence of VOCs, R i , and k i are the initial rate and the first-order rate constant, respectively, in the presence of VOCs, and [S(IV)] is the concentration of dissolved sulfur dioxide, sulfur(IV). The nature of the dependence of k i on the concentration of inhibitor, [Inh], was defined by Eq. (C).[Formula: see text]where B is an empirical inhibition parameter. The values of B have been determined from the plots of 1/k i versus [Inh]. Among aliphatic and aromatic hydroxy compounds studied, t-butyl alcohol and pinacol were without any inhibition effect due to the absence of secondary or tertiary hydrogen. The values of inhibition parameter, B, were related to k inh , the rate constant for the reaction of SO4 (-) radical with the inhibitor, by Eq. (D).[Formula: see text] Equation (D) may be used to calculate the values of either of B or k inh provided that the other is known. The extent of inhibition depends on the value of the composite term, B[Inh]. However, in accordance with Eq. (C), the extent of inhibition would be sizeable and measurable when B[Inh]?>?0.1 and oxidation of S(IV) would be almost completely stopped when B[Inh]???10. B[Inh] value can be used as a guide whether the reaction step: SO4 (-)?+?organics?[Formula: see text]?SO4 (2-)?+?non-chain products: should be included in the multiphase models or not. PMID:24638831

Dhayal, Yogpal; Chandel, C P S; Gupta, K S

2014-07-01

215

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

PubMed

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

Zhou, Anning; Ma, Xiaoliang; Song, Chunshan

2006-03-16

216

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

SciTech Connect

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

Van Miegroet, H.

1992-08-01

217

Molecular detection and isolation from antarctica of methylotrophic bacteria able to grow with methylated sulfur compounds.  

PubMed

This study is the first demonstration that a diverse facultatively methylotrophic microbiota exists in some Antarctic locations. PCR amplification of genes diagnostic for methylotrophs was carried out with bacterial DNA isolated from 14 soil and sediment samples from ten locations on Signy Island, South Orkney Islands, Antarctica. Genes encoding the mxaF of methanol dehydrogenase, the fdxA for Afipia ferredoxin, the msmA of methanesulfonate monooxygenase, and the 16S rRNA gene of Methylobacterium were detected in all samples tested. The mxaF gene sequences corresponded to those of Hyphomicrobium, Methylobacterium, and Methylomonas. Over 30 pure cultures of methylotrophs were isolated on methanesulfonate, dimethylsulfone, or dimethylsulfide from ten Signy Island lakes. Some were identified from 16S rRNA gene sequences (and morphology) as Hyphomicrobium species, strains of Afipia felis, and a methylotrophic Flavobacterium strain. Antarctic environments thus contain diverse methylotrophic bacteria, growing on various C1-substrates, including C1-sulfur compounds. PMID:16104352

Moosvi, S Azra; McDonald, Ian R; Pearce, David A; Kelly, Donovan P; Wood, Ann P

2005-08-01

218

Under sulfur's spell  

NASA Astrophysics Data System (ADS)

Thomas Rauchfuss marvels at the diversity of sulfur reactivity. Although it poisons most industrial catalysts, it adopts many forms in nature and takes on a variety of biological roles -- including that of a biocatalyst.

Rauchfuss, Thomas

2011-08-01

219

Sulfur dioxide disposal system  

Microsoft Academic Search

There is disclosed a multi-stage process for reducing sulfur dioxide to sulfur or to hydrogen sulfide whereby a hydrogen-containing gas from a high temperature gasifier is used. In the first stage of the process, the gasifier exit gas is contacted at a minimum temperature of about 1800° F. With recycle gas containing SO2, H2S, COS, mercaptans, and CS2 in order

Kamody

1981-01-01

220

DSRP, Direct Sulfur Production  

Microsoft Academic Search

Hot-gas desulfurization processes for IGCC and other advanced power applications utilize regenerable mixed-metal oxide sorbents to remove hydrogen sulfide (HâS) from raw coal gas. Regeneration of these sorbents produces an off-gas typically containing I to 3 percent sulfur dioxide (SOâ). Production of elemental sulfur is a highly desirable option for the ultimate disposal of the SOâ content of this off-gas.

S. K. Gangwal; W. J. McMichael; S. K. Agarwal; B. L. Jang; G. B. Howe; D. H. Chen; J. R. Hopper

1993-01-01

221

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

EPA Science Inventory

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

222

Rate Constants for Reactions of •OH with Several Reduced Sulfur Compounds Determined by Relative Rate Constant Method  

Microsoft Academic Search

The rate constants for the reactions between •OH and six reduced sulfur compounds in air, N2, and O2 were measured using relative rate constant method in a 180-L Teflon bag at 298 K and 1.013×105 Pa. These results were compared with previous published data and were discussed in terms of trends in different buffer gases.

Haitao Wang; Yujie Zhang; Yujin Mu

2008-01-01

223

Cure Characteristics and Thermal Properties of Sulfur-Cured EPDM-Based Composites by Compounding with Layered Nano-Organoclays  

Microsoft Academic Search

Organoclay was compounded with ethylene-propylene-diene-monomer (EPDM) using a two roll mill and cured by conventional sulfur curing system. The organoclay content was progressively increased from 0 to 10 parts per hundred of rubber (phr) of the EPDM rubber. Cure characteristics were carried out on an Ekktron moving die rheometer. It has been found that cure and scorch time were decreased

Ahmad Mousa

2006-01-01

224

Saturate biomarkers and aromatic sulfur compounds in oils and condensates from different source rock lithologies of Kazakhstan, Japan and Russia  

Microsoft Academic Search

Representative petroleums from the seven basins of Kazakhstan, Russia and Japan were analyzed using gas chromatography with dual FID\\/FPD and GC\\/MS. The present study has shown that the deviation in relative concentrations of aromatic sulfur compounds in petroleums could be related to the type of source rock. All oil samples were classified into three groups on the basis of the

Alexander Chakhmakhchev; Noriyuki Suzuki

1995-01-01

225

Sulfur metabolism in bacteria associated with cheese  

Microsoft Academic Search

Metabolism of sulfur in bacteria associated with cheese has long been a topic of interest. Volatile sulfur compounds, specifically methanethiol, are correlated to desirable flavor in Cheddar cheese, but their definitive role remains elusive. Only recently have enzymes been found that produce this compound in bacteria associated with cheese making. Cystathionine ß- and ?-lyase are found in lactic acid bacteria

Bart Weimer; Kimberly Seefeldt; Benjamin Dias

1999-01-01

226

Sulfur removal from a gas stream  

SciTech Connect

There is disclosed a process for removing sulfur compounds from a gas stream. The process involves passing the gas stream containing the sulfur compounds through a mass of porous material that has deposited upon it a metal oxide, the improvement comprises the continuous or intermittent addition of an oxidizing agent and an amine.

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

1984-03-06

227

Selectivity among organic sulfur compounds in one- and two-liquid-phase cultures of Rhodococcus sp. strain JVH1.  

PubMed

The selectivity of Rhodococcus sp. strain JVH1 among selected sulfidic and thiophenic compounds was investigated in both single-liquid-phase (aqueous) cultures and in two-liquid-phase cultures, where the sulfur compounds were dissolved in 2,2,4,4,6,8,8-heptamethylnonane as the immiscible organic carrier phase. In the single-liquid-phase cultures, Rhodococcus sp. strain JVH1 showed a preference for benzyl sulfide over both 1,4-dithiane and benzothiophene. An increased lag was observed in the degradation of benzyl sulfone and benzothiophene sulfone when both compounds were present. These results were consistent with a competitive inhibition mechanism, affecting both sulfur oxidation and carbon-sulfur bond cleavage. In the two-liquid-phase cultures, the effect of partitioning between the two liquid phases dominated the desulfurization activity of the culture. This partitioning resulted in an apparent absence of selectivity, as well as decreases in lag time, extent of degradation, and time to completion of degradation. Desulfurization activity also depended on the growth phase of the cultures. Mass transfer rate limitations were not observed at the low degradation rates of 0.02 mmol day(-1) l(-1). Owing to the importance of partitioning, Rhodococcus sp. strain JVH1 is predicted to show nonselective activity towards the sulfur species in a whole crude oil. PMID:17091345

Kirkwood, Kathlyn M; Foght, Julia M; Gray, Murray R

2007-08-01

228

Sulfur monochloride in organic synthesis  

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

229

Sulfur volcanoes on Io?  

NASA Technical Reports Server (NTRS)

The unusual rheological properties of molten sulfur, in which viscosity decreases approximately four orders of magnitude as it cools from 170 to 120 C, may result in distinctive volcanic flow morphologies that allow sulfur flows and volcanoes to be identified on Io. Search of high resolution Voyager images reveals three features--Atar Patera, Daedalus Patera, and Kibero Patera--considered to be possible sulfur volcanoes based on their morphology. All three average 250 km in diameter and are distinguished by circular-to-oval central masses surrounded by irregular, widespread flows. Geometric relations indicate that the flows were emplaced after the central zone and appear to have emanated from their margins. The central zones are interpreted to be domes representing the high temperature stage of sulfur formed initially upon eruption. Rapid quenching formed a crust which preserved this phase of the emplacement. Upon cooling to 170 C, the sulfur reached a low viscosity runny stage and was released as the thin, widespread flows.

Greeley, R.; Fink, J.

1985-01-01

230

Sodium-sulfur thermal battery  

SciTech Connect

This paper discusses a sodium-sulfur thermal battery for generating electrical energy at temperatures above the melting point of sodium metal and sulfur. It comprises a sodium electrode comprising sodium metal; a sulfur electrode comprising sulfur; and a separator located between the sodium and sulfur electrodes. The separator having sufficient porosity to allow preliminary migration of fluid sodium metal and fluid sulfur and fluid sodium polysulfides therethrough during operation of the thermal battery to form a mixed polysulfides electrolyte gradient within the separator.

Ludwig, F.A.

1990-12-11

231

Comparison of breath and in-mouth collection for the measurement of oral malodorous compounds by gas chromatography using sulfur chemiluminescence detection  

Microsoft Academic Search

Volatile sulfur compounds (VSCs), specifically hydrogen sulfide, methyl mercaptan and dimethyl sulfide, are generally considered to be the primary volatiles responsible for 'morning' malodors in breath. To date, the 'gold standard' for detecting VSC concentrations in breath is the use of gas chromatography coupled with sulfur chemiluminescence detection. Breath gas is often collected in a polypropylene syringe and then aliquots

Debbie J. Paetznick; G. A. Reineccius; T. L. Peppard; J. M. Herkert; P. Lenton

2010-01-01

232

Comparison of breath and in-mouth collection for the measurement of oral malodorous compounds by gas chromatography using sulfur chemiluminescence detection  

Microsoft Academic Search

Volatile sulfur compounds (VSCs), specifically hydrogen sulfide, methyl mercaptan and dimethyl sulfide, are generally considered to be the primary volatiles responsible for ‘morning’ malodors in breath. To date, the ‘gold standard’ for detecting VSC concentrations in breath is the use of gas chromatography coupled with sulfur chemiluminescence detection. Breath gas is often collected in a polypropylene syringe and then aliquots

Debbie J Paetznick; G A Reineccius; T L Peppard; J M Herkert; P Lenton

2010-01-01

233

Reversible formation of ammonium persulfate/sulfuric acid graphite intercalation compounds and their peculiar Raman spectra.  

PubMed

Graphite intercalation compounds (GICs) can be considered stacks of individual doped graphene layers. Here we demonstrate a reversible formation of sulfuric acid-based GICs using ammonium persulfate as the chemical oxidizing agent. No covalent chemical oxidation leading to the formation of graphite oxide occurs, which inevitably happens when other compounds such as potassium permanganate are used to charge carbon layers. The resulting acid/persulfate-induced stage-1 and stage-2 GICs are characterized by suppression of the 2D band in the Raman spectra and by unusually strong enhancement of the G band. The G band is selectively enhanced at different doping levels with different excitations. These observations are in line with recent reports for chemically doped and gate-modulated graphene and support newly proposed theories of Raman processes. At the same time GICs have some advantageous differences over graphene, which are demonstrated in this report. Our experimental observations, along with earlier reported data, suggest that at high doping levels the G band cannot be used as the reference peak for normalizing Raman spectra, which is a commonly used practice today. A Fermi energy shift of 1.20-1.25 eV and ?1.0 eV was estimated for the stage-1 and stage-2 GICs, respectively, from the Raman and optical spectroscopy data. PMID:22880798

Dimiev, Ayrat M; Bachilo, Sergei M; Saito, Riichiro; Tour, James M

2012-09-25

234

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

PubMed

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

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

2013-04-01

235

The relationship between oral malodor and volatile sulfur compounds producing bacteria  

Microsoft Academic Search

Objectives: Halitosis can be a crippling social problem where the standard dental treatments and mouthwashes often recommended provide only temporary relief. Oral malodor is primarily the result of microbial metabolism. The mouth is home to hundreds of bacterial species with various nutritional preferences. These organisms enjoy proteins, as they digest proteins several fetid substances arise. The role of volatile sulfur

Yosef P. Krespi; Mel Rosenberg

2004-01-01

236

Catalyst for the reduction of sulfur dioxide to elemental sulfur  

DOEpatents

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

Jin, Yun (Peking, CN); Yu, Qiquan (Peking, CN); Chang, Shih-Ger (El Cerrito, CA)

1996-01-01

237

Sulfur in achondritic meteorites  

NASA Astrophysics Data System (ADS)

The sulfur abundances of samples of nearly 50 achondrites were examined to enlarge the database on the sulfur contents of various categories of achondrites. The study covered eucrites, howardites, diogenites, shergottites, chassignites, nakhilites, aubrites and three unique specimens. The study was spurred by the possibility that the S abundances could help identify the meteorites as originating on Mars or Venus. The S abundances and distributions varied widely, but confirmed that the data were valid indicators of the brecciation and thermal metamorphic history of each meteorite.

Gibson, E. K.; Moore, C. B.; Primus, T. M.; Lewis, C. F.

1985-09-01

238

Process for removing sulfur from coal  

DOEpatents

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

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

1983-08-11

239

Process for removing sulfur from coal  

DOEpatents

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

Aida, Tetsuo (Ames, IA) [Ames, IA; Squires, Thomas G. (Gilbert, IA) [Gilbert, IA; Venier, Clifford G. (Ames, IA) [Ames, IA

1985-02-05

240

Zinc chloride-catalyzed reactions of oxygen- and sulfur-containing compounds which model structures in coal  

SciTech Connect

Ether structures are believed to play a key role in linking the macromolecular units present in coal. A number of compounds which model the ether and sulfur structures found in coal were subjected to reaction in the presence of zinc chloride. Reactions were carried out in a batch autoclave at temperatures between 136/sup 0/C and 327/sup 0/C and under hydrogen or nitrogen pressure up to 16.8 MPa. Both cyclic and non-cyclic ethers reacted, provided that at least one methylene group was adjacent to the ether oxygen atom. Complete elimination of oxygen to form water was achieved with dibenzyl and cycloaliphatic ethers, but oxygen bonded directly to a phenyl or naphthyl group was converted to an unreactive phenolic hydroxyl group. As for the sulfur compounds, zinc chloride was found to promote removal of sulfur from sulfides and disulfides in which sulfur is bonded to a methylene group, but had no effect on diaryl sulfides, diaryl disulfides, or thiophenic structures. In those cases where sulfur was removed, a significant portion was found to be retained in the ZnCl/sub 2/ phase. The reaction products observed in both cases can be explained in terms of carbonium ion mechanisms similar to those used to explain Friedel-Crafts chemistry. In these mechanisms, the ZnCl/sub 2/ may be active in either a Lewis acid or a Bronsted acid form. Catalytic effects of nickel, zinc and magnesium and also the sulfides of nickel, zinc, iron and molybdenum on the reactions of dibenzyl ether and zinc chloride were also investigated. The presence of the metallic component enhanced the hydrogenolysis of dibenzyl ether, whereas the presence of ZnCl/sub 2/ reduced the activity of the NiS.

Mobley, D.P.

1980-05-01

241

Analysis of aromatic sulfur compounds in gas oils using GC with sulfur chemiluminescence detection and high-resolution MS.  

PubMed

The analysis of alkylbenzothiophenes (alkyl-BT) and alkyl-dibenzothiophenes (alkyl-DBT) in light cycle oil (LCO) and straight run (SR) gas oils is described. A detailed identification and quantitative analysis of alkyl-BT and alkyl-DBT present in LCO gas oils was carried out using GC-SCD. For the SR gas oils, the simultaneous presence of thiophenic and nonthiophenic compounds does not allow for a selective analysis of thiophenic compounds by GC-SCD. A new method using gas chromatography coupled with high-resolution mass spectrometry (GC-HRMS) is proposed to selectively detect and quantify the alkyl-BT and alkyl-DBT in SR gas oils. The development of the method and comparison of results between GC-SCD and GC-HRMS are presented. PMID:12175175

García, C López; Becchi, M; Grenier-Loustalot, M F; Païsse, O; Szymanskit, R

2002-08-01

242

Process for producing sulfur from sour gas  

Microsoft Academic Search

A method is described for the recovery of free sulfur from sour gas streams by the catalytic conversion of hydrogen sulfide, under conditions such that unreacted sulfur compounds discharged to the atmosphere are held to a minimum. This is accomplished by taking advantage of the increased recovery obtained by the use of low temperature reactors. In a 3-reactor plant, the

1973-01-01

243

Sulfur Concrete for Polar Construction.  

National Technical Information Service (NTIS)

Experimental studies on sulfur concrete in the laboratory and at McMurdo Station, Antarctica are described. Sulfur concrete mixtures showed high tensile, flexural, and compressive strengths as well as high Young's Modulus in the laboratory.

J. R. Keeton

1972-01-01

244

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

NASA Astrophysics Data System (ADS)

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

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

2011-07-01

245

In vitro growth characteristics and volatile sulfur compound production of Solobacterium moorei.  

PubMed

Solobacterium moorei has recently been implicated as a causative agent of halitosis. In vitro experiments to evaluate the role of S. moorei in halitosis have, however, been complicated by a paucity of information on the ideal conditions for culturing this organism. This work aimed to optimize a liquid culture medium for S. moorei, and to determine the growth-curve of the organism. Further, the ability of S. moorei to generate volatile sulfur compounds was investigated and compared quantitatively to other oral anaerobes by an optimized head-space gas chromatography method. Serum-supplementation of standard liquid growth media gave greater growth of S. moorei than non-supplemented broths, with the best medium found to be serum-supplemented tryptone soya broth. S. moorei was able to metabolize cysteine directly to hydrogen sulfide, but was unable to produce methanethiol from methionine. S. moorei produced 2-3 times more hydrogen sulfide (normalized for colony forming units) than Porphyromonas gingivalis and Veillonella dispar, but considerably less than Fusobacterium nucleatum. The study has identified reliable growth conditions for culture of S. moorei, which were employed to show that S. moorei has the requisite biochemistry consistent with a potential role in halitosis. PMID:24487184

Stephen, Abish S; Naughton, Declan P; Pizzey, Robert L; Bradshaw, David J; Burnett, Gary R

2014-04-01

246

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

SciTech Connect

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

Delmas, R.; Servant, J.

1982-12-20

247

Selectivity of molybdenum catalyst in hydrodenitrogenation, hydrodesulfurization, and hydrodeoxygenation: effects of sulfur and oxygen compounds on acridine hydrodenitrogenation  

SciTech Connect

The selectivity of a Mo/Al/sub 2/O/sub 3/ catalyst in denitrogenation, desulfurization, and deoxygenation based on the retarding effect of sulfur and oxygen compounds on acridine hydrodenitrogenation has been studied. The experiments were done in a continuous flow microreactor at 280-380/sup 0/C and 10.1 MPa total pressure. Sulfidation of the reduced catalyst hindered the denitrogenation of perhydroacridine to dicyclohexylmethane. The sulfur and oxygen compounds, except for a small amount of CS/sub 2/, depressed the denitrogenation at higher temperatures where the intermediate hydrogenations of acridine to perhydroacridine attained equilibria. At lower temperatures, all the additives affected the hydrogenation of octahydroacridine to perhydroacridine which was not at equilibrium and resulted in a decrease of denitrogenation. The kinetics and reaction mechanism of the retarding effects are also discussed.

Nagai, M.; Masunaga, T.; Hana-Oka, N.

1986-10-01

248

Adventures in Organic Sulfur Chemistry  

Microsoft Academic Search

On several occasions, SULFUR REPORTS has invited persons who have done outstanding work in sulfur chemistry to summarize highlights of their research career in a semiautobiographical review. The present account is from a distinguished chemist who has contributed importantly for nearly 50 years to medicinal and organic aspects of sulfur chemistry. Ernest E. Campaigne (who prefers simply E. Campaigne) was

E. Campaigne

1990-01-01

249

Meteoritic Sulfur Isotopic Analysis  

NASA Technical Reports Server (NTRS)

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

Thiemens, Mark H.

1996-01-01

250

Sulfur dioxide removal process  

SciTech Connect

A process is described for removing sulfur dioxide from a gas stream with a buffered, aqueous thiosulfate/polythionate solution which comprises: (a) introducing sulfur dioxide-containing gas, recovered hydrogen sulfide, and a buffered, aqueous, lean thiosulfate/polythionate solution to an SO/sub 2/-gas/liquid contacting zone; (b) recovering cleaned gas and a buffered, aqueous, enriched thiosulfate/polythionate solution from the SO/sub 2/-gas/liquid contacting zone; (c) introducing the recovered, enriched solution to a regeneration zone; (d) introducing externally supplied hydrogen sulfide to the regeneration zone to react a portion of the recovered, enriched solution therein to form a slurry of elemental sulfur in a buffered, aqueous, lean thiosulfate/polythionate solution; (e) recovering unreacted excess hydrogen sulfide from the regeneration zone for use in step (a); and (f) withdrawing the slurry from the regeneration zone, separating elemental sulfur from the slurry, and recovering the buffered, aqueous, lean thiosulfate/polythionate solution for use in step (a).

Sliger, A.G.; O'Donnell, J.J.; Northup, A.H. Jr.

1987-01-06

251

Sulfur Dioxide Detector.  

National Technical Information Service (NTIS)

A composition is provided for detecting the presence of sulfur dioxide by changing color. One type of composition is prepared by mixing a small amount of finely ground potassium permanganate with finely powdered activated silica gel to produce a lilac col...

J. A. Amy H. C. Huber

1980-01-01

252

CONTROLLING SULFUR OXIDES  

EPA Science Inventory

This Research Summary describes EPA's program to develop new and improve existing technologies for sulfur oxides control. As we increasingly turn to coal as the primary utility and industrial fuel, while trying to deal with the problems of acid precipitation, visibility degradati...

253

COAL SULFUR MEASUREMENTS  

EPA Science Inventory

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

254

SULFUR POLYMER ENCAPSULATION.  

SciTech Connect

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

KALB, P.

2001-08-22

255

SULFUR AND BORON-MAGNESIUM-ZINC COMPOUND FERTILIZER CONTRIBUTE TO THE REPRODUCTIVE GROWTH OF JATROPHA CURCAS L  

Microsoft Academic Search

Jatropha curcas L., a native tree to Mexico and Central America, is cultivated in many counties of China as a source for biodiesel. The effects of different fertilizers on the growth of Jatropha curcas L. were studied under soil conditions of low nitrogen (N), phosphorus (P), potassium (K) and boron (B) in soil. Compared with 16N-16P-16K compound fertilizer, both sulfur

Gang Xu; Rui Wang

2011-01-01

256

Heterologous Production of Methionine Lyase from Brevibacterium linens in Lactococcus lactis and Formation of Volatile Sulfur Compounds  

Microsoft Academic Search

The conversion of methionine to volatile sulfur compounds (VSCs) is of great importance in flavor formation during cheese ripening and is the focus of biotechnological approaches toward flavor improvement. A synthetic mgl gene encoding methionine--lyase (MGL) from Brevibacterium linens BL2 was cloned into a Lactococcus lactis expression plasmid under the control of the nisin-inducible promoter PnisA. When expressed in L.

Sean B. Hanniffy; Mark Philo; Carmen Pelaez; Michael J. Gasson; Teresa Requena; M. C. Martinez-Cuesta

2009-01-01

257

Headspace SPME followed by GC\\/PFPD for the analysis of malodorous sulfur compounds in liquid industrial effluents  

Microsoft Academic Search

Headspace SPME was used to analyse malodorous sulfur compounds in liquid industrial effluents. A pulsed flame photometric detector (PFPD) was selected for a specific and sensitive analysis. Two fibres, PDMS\\/Dvb and PDMS\\/Carboxen, which are particularly convenient for extracting small and volatile molecules were tested. To compare these fibres, both sensitivity and artefact formation were considered. The PDMS\\/Carboxen fibre showed the

François Lestremau; Valérie Desauziers; Jean-Louis Fanlo

2004-01-01

258

Simultaneous measurement of volatile sulfur compounds using ascorbic acid for oxidant removal and gas chromatography–flame photometric detection  

Microsoft Academic Search

A method for the simultaneous measurement of volatile sulfur compounds (COS, H2S, CS2, CH3SH, DMS) is established with preconcentration and GC–flame photometric detection (FPD). Prior to preconcentration of ambient air, it was necessary to remove SO2, water vapor and atmospheric oxidant. SO2 and water vapor were removed using a glass fiber filter and a cooled PTFE water trap loop, respectively.

Yayoi Inomata; Katsuji Matsunaga; Yasuhiro Murai; Kazuo Osada; Yasunobu Iwasaka

1999-01-01

259

Combined chemical and microbiological removal of organic sulfur from coal  

SciTech Connect

The objective of this work is to investigate techniques for chemically converting the sulfur containing organic compounds in coal to compounds that can be treated microbiologically to remove the organically bound sulfur. The goal is to achieve an economically feasible mild chemical oxidation of the organic sulfur in a representative Illinois Basin coal by converting the sulfur to sulfoxides and sulfones; the carbon sulfur bond in the sulfoxides and sulfones would then be broken microbiologically and the sulfur removed from the coal as sulfate.

Raphaelian, L.A.

1991-01-01

260

Activity of vanadium catalysts for sulfuric acid production, promoted with Na, K, Rb, Cs, and Mg compounds, at various pressures of sulfur oxides  

Microsoft Academic Search

The activities of vanadium catalysts promoted with Na, K, Rb, Cs, and Mg sulfates (ratio Me:V = 4) were studied in conditions of low (up to 1 kPa) and high (up to 70 kPa) partial pressures of sulfur oxides at 693 and 758 K. The authors report results of reaction kinetic studies.

S. V. Ivanenko; R. R. Dzhoraev

1995-01-01

261

Hydrogen atom induced substitution reaction of organic sulfur compounds in the gas phase  

Microsoft Academic Search

This paper reports on the gas-phase reaction of CHâSH with hydrogen (or deuterium) atoms that was studied in a conventional discharge-flow apparatus under varying conditions. The product distribution suggested that, in addition to normal abstraction reaction such as CHâSH + H° â CHâS° + Hâ, a unique substitution reaction on the sulfur atom such as CHâSH + H° â CHâS(H)H

Muneyoshi Yamada; Akira Amano

1992-01-01

262

Experimental verification of structural alerts for the protein binding of sulfur-containing compounds.  

PubMed

As often noted by Dr. Gilman Veith, a major barrier to advancing any model is defining its applicability domain. Sulfur-containing industrial organic chemicals can be grouped into several chemical classes including mercaptans (RSH), sulfides (RSR'), disulfides (RSSR'), sulfoxides (RS(=O)R'), sulfones (RS(=O)(=O)R'), sulfonates (ROS(=O)(=O)R') and sulfates (ROS(=O)(=O)OR'). In silico expert systems that predict protein binding reactions from 2D structure sub-divide these chemical classes into a variety of chemical reactive mechanisms and reactions which have toxic consequences. Using the protein binding profilers in version 3.1 of the OECD QSAR Toolbox, a series of sulfur-containing chemicals were profiled for protein binding potential. From these results it was hypothesized which sulfur-containing chemicals would be reactive or non-reactive in an in chemico glutathione assay and whether if reactive they would exhibit toxicity in excess of baseline in the Tetrahymena pyriformis population growth impairment assay. Subsequently, these hypotheses were tested experimentally. The in chemico data show that the in silico profiler predictions were generally correct for all chemical categories, where testing was possible. Mercaptans could not be assessed for GSH reactivity because they react directly with the chromophore 5,5'-dithiobis-(2-nitrobenzoic acid). With some exceptions, the major being disulfides, the in vitro toxicity data supported the in chemico findings. PMID:24749900

Richarz, A N; Schultz, T W; Cronin, M T D; Enoch, S J

2014-04-01

263

Relative energy of organic compounds II. Halides, nitrogen, and sulfur compounds  

Microsoft Academic Search

The energies of the following types of compounds are characterized by their calculated relative enthalpies: alkyl, alkenyl,\\u000a and aryl halides; carboxylic acid halides; carbonyl halides; amines; carboxylic acid amides; hydrazine derivatives; nitriles;\\u000a heteroaromatic compounds; nitro-compounds; organic nitrites and nitrates; organic sulfides; thiols; disulfides; sulfoxides;\\u000a sulfones; organic sulfites and sulfates; and selected inorganic compounds. Stabilization energy of pyrrol and thiophene has

Árpád Furka

2009-01-01

264

Chemical Removal of Nitrogen and Organic Sulfur from Coal.  

National Technical Information Service (NTIS)

Techniques for extracting organic sulfur and nitrogen compounds from coal without significantly altering the remainder of the coal matrix were tested in the laboratory. The concept for chemical removal of organic sulfur and nitrogen is feasible. Weak orga...

R. A. Meyers J. S. Land C. A. Flegal

1971-01-01

265

Volatile sulfur compounds in Cheddar cheese determined by headspace solid-phase microextraction and gas chromatograph-pulsed flame photometric detection  

Microsoft Academic Search

The aim of this study was to develop a methodology for the analysis of volatile sulfur compounds (VSCs) in Cheddar cheese. Solid-phase microextraction (SPME) was employed to extract VSCs from the cheese matrix using a CAR-PDMS fiber. This extraction method was combined with gas chromatography–pulsed flame photometric detection (GC–PFPD) to achieve high sensitivity for sulfur compounds. The impact of extraction

Helen M. Burbank; Michael C. Qian

2005-01-01

266

The contribution of sulfuric acid and non-volatile compounds on the growth of freshly formed particles at Melpitz  

NASA Astrophysics Data System (ADS)

A field campaign was conducted at atmospheric research station Melpitz, near Leipzig, Germany from May 1st to May 30th 2008 in the frame of the EUCAARI (European integrated project on aerosol, cloud, climate, and air interactions) project. During this experiment, the gas-phase sulfuric acid concentrations were measured for the first time in Melpitz, which presents an opportunity to examine the contribution of sulfuric acid as well as other compounds to the growth of newly formed particles. In addition, a Twin Differential Mobility Particle Sizer (TDMPS) in conjunction with and without a thermodenuder (TD) have been used to measure continuously the particle number size distribution from 3-800 nm at Melpitz since July 2003 along with meteorological parameters and trace gases concentrations. Aerosol particles typically grew from 3 nm to 60-70 nm during a day, while their nonvolatile cores grew by 10-20 nm as well. The total particle growth rate was 3-6 nm/h, while the nonvolatile core material can explain 16-28%. According to our results, sulfuric acid can explain 9-49% of the growth while the remainder of the growth can be explained due to possibly secondary organic compounds.

Hamed, A.; Wang, Z.; Birmili, W.; Plass-Dülmer, C.; Wiedensohler, A.

2013-05-01

267

Elimination of sludge odor by oxidizing sulfur-containing compounds with ferrate(VI).  

PubMed

Sulfur-containing compounds are one kind of odorant found in sewage treatment works, composting plants, refuse storage and transfer, landfill sites, and associated with various industries. In the present research, the reaction kinetics of ferrate(VI) (Fe(VI)O4(-), Fe(VI)) with 2-mercaptobenzothiazole (MBT), thiosemicarbazide (NH2NHC(S)NH2, TSC), and thiourea dioxide (NH2C(SO2)NH2, TUDO) were studied under alkaline conditions. Stoichiometryof Fe(VI) oxidation with hydrogen sulfide (H2S), TSC, and methyl mercaptan (CH3SH) were determined at neutral and alkaline pH (7.0-11.0). Stoichiometric molar ratios ([Fe(VI):[S]) were determined to be 2.5, 2.0, and 4.6 for sulfide, TSC, and CH3SH, respectively, at pH 9.0. TUDO and methyl sulfonic acid (CH3SO3H) were identified to be the main intermediates of TSC and CH3SH reactions with Fe(VI), respectively, at pH 9.0, while sulfate was one of the final products. A reaction scheme is given to explain the intermediates and products formed in the CH3SH degradation by Fe(VI). Experiments were also conducted to evaluate the odor emission of digested sludge from sewage treatment works in terms of chemical concentration and also odor concentration affected by the Fe(VI) dose. The potential of using Fe(VI) to achieve odor control in sludge treatment is briefly discussed. PMID:19731693

He, Chun; Li, Xiang-Zhong; Sharma, Virender K; Li, Shi-Yu

2009-08-01

268

Effects of stress hormones on the production of volatile sulfur compounds by periodontopathogenic bacteria.  

PubMed

Little is known about the effects of stress hormones on the etiologic agents of halitosis. Thus, the aim of this study was to evaluate in vitro the effects of adrenaline (ADR), noradrenaline (NA) and cortisol (CORT) on bacteria that produce volatile sulfur compounds (VSC), the major gases responsible for bad breath. Cultures of Fusobacterium nucleatum (Fn), Porphyromonas endodontalis (Pe), Prevotella intermedia (Pi) and Porphyromonas gingivalis (Pg) were exposed to 50 µM ADR, NA and CORT or equivalent volumes of sterile water as controls for 12 and 24 h. Growth was evaluated based on absorbance at 660 nm. Portable gas chromatography was used to measure VSC concentrations. Kruskal-Wallis and the Dunn post-hoc test were used to compare the groups. For Fn, ADR, NA and CORT significantly reduced bacterial growth after 12 h and 24 h (p<0.05). All the substances tested increased hydrogen sulfide (H2S) production (p<0.05). For Pe, all the substances tested reduced bacterial development after 24 h (p<0.05), and NA significantly increased the H2S concentration after 12 h (p<0.05). In the Pg and Pi cultures, no effects on bacterial growth were observed (p>0.05). In the Pi cultures, ADR, NA and CORT increased H2S (p<0.05). Catecholamines and cortisol can interfere with growth and H2S production of sub-gingival species in vitro. This process appears to be complex and supports the association between stress and the production of VSC. PMID:24918364

Calil, Caroline Morini; Oliveira, Gisele Mattos; Cogo, Karina; Pereira, Antonio Carlos; Marcondes, Fernanda Klein; Groppo, Francisco Carlos

2014-01-01

269

Use of Oral Chroma™ in the assessment of volatile sulfur compounds in patients with fixed protheses.  

PubMed

Prosthetic rehabilitation improves the patient's quality of life and oral health. The purpose of the present study was to assess the production of volatile sulfur compounds (VSCs) using Oral Chroma? in patients wearing provisional and permanent fixed prosthesis, who were treated or not, with supportive non-surgical periodontal therapy. A total of 10 healthy patients not affected by periodontal disease and who needed the restoration of at least two edentulous single sites were included in the present study. Registrations of VSCs were carried out with a Gas Chromatograph OralChroma™ (Oral Chroma™, Abimedical, Abilit Corp., Osaka, Japan) one month after placement of the provisional restoration (group 1) and one month after placement of the final restoration (group 3). After each measurement, professional oral hygiene was carried out both on patients with provisional (group 2) and permanent prostheses (group 4) and VSC values were registered. The results showed that there were no statistical significant differences in the VSC quantity between groups with temporary or permanent prostheses. Meanwhile, statistically significant differences were found in VCS values between groups before and after the professional health care session (p less than 0.05). Also it was observed that dimethyl sulphide (CH3)2S was present in all the study groups. The present preliminary study suggests that OralChroma™ produce a comprehensive assessment of VSC in the clinical diagnosis of halitosis and that professional oral hygiene seems to influence VSC production. However, further clinical long-term studies with a larger sample size are necessary for a better understanding of halitosis manifestation in patients wearing provisional and permanent fixed prosthesis. PMID:24067465

Sinjari, B; Murmura, G; Caputi, S; Ricci, L; Varvara, G; Scarano, A

2013-01-01

270

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

PubMed

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

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

2013-06-01

271

Genomic Insights into the Sulfur Metabolism of Phototrophic Green Sulfur Bacteria  

Microsoft Academic Search

Green sulfur bacteria (GSB) utilize various combinations of sulfide, elemental sulfur, thiosulfate, ferrous iron, and hydrogen\\u000a for anaerobic photoautotrophic growth. Genome sequence data is currently available for 12 strains of GSB. We present here\\u000a a genome-based survey of the distribution and phylogenies of genes involved in oxidation of sulfur compounds in these strains.\\u000a Sulfide:quinone reductase, encoded by sqr, is the

Niels-Ulrik Frigaard; Donald A. Bryant

272

Effect of sulfur compounds on biological reduction of nitric oxide in aqueous Fe(II)EDTA2- solutions.  

PubMed

Biological reduction of nitric oxide (NO) in aqueous solutions of EDTA chelated Fe(II) is one of the main steps in the BioDeNOx process, a novel bioprocess for the removal of nitrogen oxides (NOx) from polluted gas streams. Since NOx contaminated gases usually also contain sulfurous pollutants, the possible interferences of these sulfur compounds with the BioDeNOx process need to be identified. Therefore, the effect of the sulfur compounds Na2SO4, Na2SO3, and H2S on the biological NO reduction in aqueous solutions of Fe(II)EDTA2- (25 mM, pH 7.2, 55 degrees C) was studied in batch experiments. Sulfate and sulfite were found to not affect the reduction rate of Fe(II)EDTA2- complexed NO under the conditions tested. Sulfide, either dosed externally or formed during the batch incubation out of endogenous sulfur sources or the supplied sulfate or sulfite, influences the production and consumption of the intermediate nitrous oxide (N2O) during Fe(II)EDTA2- bound NO reduction. At low concentrations (0.2 g VSS/l) of denitrifying sludge, 0.2 mM free sulfide completely inhibited the nitrosyl-complex reduction. At higher biomass concentrations (1.3-2.3 g VSS/l), sulfide (from 15 microM to 0.8 mM) induced an incomplete NO denitrification with N2O accumulation. The reduction rates of NO to N2O were enhanced by anaerobic sludge, presumably because it kept FeEDTA in the reduced state. PMID:16517188

Manconi, Isabella; van der Maas, Peter; Lens, Piet N L

2006-08-01

273

Sulfur plumes off Namibia  

NASA Technical Reports Server (NTRS)

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

2002-01-01

274

Acidithiobacillus caldus Sulfur Oxidation Model Based on Transcriptome Analysis between the Wild Type and Sulfur Oxygenase Reductase Defective Mutant  

PubMed Central

Background Acidithiobacillus caldus (A. caldus) is widely used in bio-leaching. It gains energy and electrons from oxidation of elemental sulfur and reduced inorganic sulfur compounds (RISCs) for carbon dioxide fixation and growth. Genomic analyses suggest that its sulfur oxidation system involves a truncated sulfur oxidation (Sox) system (omitting SoxCD), non-Sox sulfur oxidation system similar to the sulfur oxidation in A. ferrooxidans, and sulfur oxygenase reductase (SOR). The complexity of the sulfur oxidation system of A. caldus generates a big obstacle on the research of its sulfur oxidation mechanism. However, the development of genetic manipulation method for A. caldus in recent years provides powerful tools for constructing genetic mutants to study the sulfur oxidation system. Results An A. caldus mutant lacking the sulfur oxygenase reductase gene (sor) was created and its growth abilities were measured in media using elemental sulfur (S0) and tetrathionate (K2S4O6) as the substrates, respectively. Then, comparative transcriptome analysis (microarrays and real-time quantitative PCR) of the wild type and the ?sor mutant in S0 and K2S4O6 media were employed to detect the differentially expressed genes involved in sulfur oxidation. SOR was concluded to oxidize the cytoplasmic elemental sulfur, but could not couple the sulfur oxidation with the electron transfer chain or substrate-level phosphorylation. Other elemental sulfur oxidation pathways including sulfur diooxygenase (SDO) and heterodisulfide reductase (HDR), the truncated Sox pathway, and the S4I pathway for hydrolysis of tetrathionate and oxidation of thiosulfate in A. caldus are proposed according to expression patterns of sulfur oxidation genes and growth abilities of the wild type and the mutant in different substrates media. Conclusion An integrated sulfur oxidation model with various sulfur oxidation pathways of A. caldus is proposed and the features of this model are summarized.

Chen, Linxu; Ren, Yilin; Lin, Jianqun; Liu, Xiangmei; Pang, Xin; Lin, Jianqiang

2012-01-01

275

Solidphase microextraction—Gas chromatography to determine volatile organic sulfur compounds in the air at sewage treatment plants  

Microsoft Academic Search

Solid-phase microextraction (SPME) was applied to the determination of 7 volatile organic sulfur compounds (VOSCs), which were analysed by gas chromatography–mass spectrometry. The compounds studied were ethyl mercaptan (CH3CH2SH), dimethyl sulfide ((CH3)2S), carbon disulfide (CS2), propyl mercaptan (C3H8S), butyl mercaptan (C4H10S), dimethyl disulfide ((CH3)2S2) and 1-pentanethiol (C5H12S). Temperature and time conditions of SPME extraction were optimised and the method was

Maria Rosa Ras; Rosa Maria Marcé; Francesc Borrull

2008-01-01

276

Elemental sulfur analysis  

NASA Astrophysics Data System (ADS)

Elemental sulfur as total zerovalent sulfur, S(0), is frequently measured in anoxic and/or sulfidic waters, and at the interface of oxic and anoxic waters. Examples of bodies of water with oxic-anoxic interfaces are the Black Sea, Kau Bay, the Cariaco Trench, the northern Chesapeake Bay, Saanich inlet, Framvaren fjord and the brines at the bottom of the Mediterranean Sea. The sampling and analytical procedures commonly used are given below. Samples are obtained from Go-Flo bottles off the CTD rosette system. The Go-Flo bottles are attached to a N2 cylinder to maintain N2 over the water during collection. A positive pressure is maintained so that water from the bottles would be able to be filtered hermetically through 0.2 ?m Nuclepore filters directly into polypropylene or glass syringes. The syringes are equipped with three way stopcocks so that the lines from the Go-Flo bottles can be purged of air during sampling. This insures that no O2 can enter the syringe or the filter device and cause sulfide oxidation resulting in elemental sulfur formation. The syringes are stored in N2 filled glove bags or ziploc bags for subsequent analysis.

Luther, George W., III

277

Sulfur Deactivation of Fatty Ester Hydrogenolysis Catalysts  

Microsoft Academic Search

Trace organosulfur compounds present as natural impurities in oleochemical feedstocks may lead to deactivation of copper-containing catalysts applied for hydrogenolysis of esters toward fatty alcohols. In this paper, the sulfur deactivation of Cu\\/SiO2 and Cu\\/ZnO\\/SiO2 catalysts was studied in the liquid-phase hydrogenolysis of methyl palmitate. The rate of deactivation is fast and increases as a function of the sulfur-containing compound

D. S. Brands; G. U-A-Sai; E. K. Poels; A. Bliek

1999-01-01

278

Effects of heteroatom substitution in conjugated heterocyclic compounds on photovoltaic performance: from sulfur to tellurium.  

PubMed

We report a general strategy for fine-tuning the bandgap of donor-acceptor-donor based organic molecules by modulating the electron-donating ability of the donor moiety by changing the benzochalcogenophene donor groups from benzothiophenes to benzoselenophenes to benzotellurophenes. These molecules show red-shifts in absorption and external quantum efficiency maxima from sulfur to selenium to tellurium. In bulk heterojunction solar cell devices, the benzoselenophene derivative shows a power conversion efficiency as high as 5.8% with PC61BM as the electron acceptor. PMID:24842497

Park, Y S; Kale, T S; Nam, C-Y; Choi, D; Grubbs, R B

2014-06-26

279

Inhibition of heterocyclic aromatic amine formation in fried ground beef patties by garlic and selected garlic-related sulfur compounds.  

PubMed

The effects of garlic and selected organosulfur compounds (diallyl disulfide, dipropyl disulfide, diallyl sulfide, allyl methyl sulfide, allyl mercaptan, cysteine, and cystine) on the formation of heterocyclic aromatic amines (HAAs) in fried ground beef patties were evaluated. Minced garlic cloves (ca. 4.8 to 16.7%, wt/wt) or organosulfur compounds (0.67 mmol) were added directly to ground beef. Patties (100 g) were fried at 225 degrees C (surface temperature) for 10 min per side. Two patties were fried for each replication, and five replicates were analyzed for each treatment. For each replicate, four subsamples were analyzed (two unspiked subsamples for concentration and two spiked subsamples for the recovery of HAA standards). The volatile sulfur compounds significantly (P < 0.05) reduced concentrations of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine by reductions of 46 to 81%, while average reductions of 35, 22, and 71%, were achieved with cystine, cysteine, and whole garlic, respectively. The volatile sulfur compounds reduced concentrations of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline by 34 to 67%, while reductions of 25, 19, and 63% (P < 0.05) were achieved with cystine, cysteine, and whole garlic, respectively. These studies confirm that garlic and some organosulfur compounds have the potential to reduce HAA formation incooked beef patties. PMID:12430700

Shin, Inn-Seung; Rodgers, W John; Gomaa, Enayat A; Strasburg, Gale M; Gray, J Ian

2002-11-01

280

Origin and diagenetic transformations of C sub 25 and C sub 30 highly branched isoprenoid sulfur compounds: Further evidence for the formation of organically bound sulfur during early diagenesis  

SciTech Connect

A number of C{sub 25} and C{sub 30} highly branched isoprenoid (HBI) sulfur compounds (e.g., thiolanes, 1-oxo-thiolanes, thiophenes, and benzo(b)thiophenes) with 2,6,10,14-tetramethyl-7-(3-methylpentyl)pentadecane and 2,6,10,14,18-pentamethyl-7-(3-methylpentyl)nonadecane carbon skeletons were identified in sediments, ranging from Holocene to Upper Cretaceous. These identifications are based on mass spectral characterization, desulfurization, and, in some cases, by comparison of mass spectral and relative retention time data with those of authentic standards. The presence of unsaturated C{sub 25} and C{sub 30} HBI thiolanes in a Recent sediment from the Black Sea (age 3-6 {times} 10{sup 3} a) strongly supports their formation during early diagenesis. The co-occurrence of HBI polyenes (C{sub 25} and C{sub 30}) and unsaturated HBI thiolanes (C{sub 25} and C{sub 30}) possessing two double bonds less than the corresponding HBI polyenes, in this Recent sediment, testifies to the formation of unsaturated HBI thiolanes by a reaction of inorganic sulfur species with double bonds of the HBI polyenes. Furthermore, a diagenetic scheme for HBI sulfur compounds is proposed based on the identification of HBI sulfur compounds in sediment samples with different maturity levels.

Kohnen, M.E.L.; Damste, J.S.S.; Kock-Van Dalen, A.C.; de Leeuw, J.W. (Delft Univ. of Technology (Netherlands)); Ten Haven, H.L.; Rullkoetter, J. (Institute of Petroleum and Organic Geochemistry, Juelich (West Germany))

1990-11-01

281

The Mauna Loa sulfur flow as an analog to secondary sulfur flows on Io  

NASA Astrophysics Data System (ADS)

Independent evidence suggests that both sulfur and silicate materials exist on the surface of Io. Spectral data indicate the presence of sulfur compounds, some of which are suggested to be of fumarolic origin. Morphological evidence and inferences of the physical properties of some land-forms suggest that silicate volcanism has occurred, which would involve temperatures 650 C or greater. Because the liquidus of sulfur is only about 115 C, it is likely that sulfur in close proximity to 'hot spots' or to active silicate volcanic areas on Io would be melted and mobilized as flows. The Mauna Loa sulfur flow may serve as an analog for such flows, as it consists of fumarolic sulfur that was melted as a consequence of a basaltic eruption and produced a small flow superimposed on silicate lavas.

Greeley, R.; Theilig, E.; Christensen, P.

1984-10-01

282

Catalyst for the reduction of sulfur dioxide to elemental sulfur  

DOEpatents

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.

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

1996-02-27

283

Use of a Novel Fluorinated Organosulfur Compound To Isolate Bacteria Capable of Carbon-Sulfur Bond Cleavage  

PubMed Central

The vacuum residue fraction of heavy crudes contributes to the viscosity of these oils. Specific microbial cleavage of C—S bonds in alkylsulfide bridges that form linkages in this fraction may result in dramatic viscosity reduction. To date, no bacterial strains have been shown conclusively to cleave C—S bonds within alkyl chains. Screening for microbes that can perform this activity was greatly facilitated by the use of a newly synthesized compound, bis-(3-pentafluorophenylpropyl)-sulfide (PFPS), as a novel sulfur source. The terminal pentafluorinated aromatic rings of PFPS preclude growth of aromatic ring-degrading bacteria but allow for selective enrichment of strains capable of cleaving C—S bonds. A unique bacterial strain, Rhodococcus sp. strain JVH1, that used PFPS as a sole sulfur source was isolated from an oil-contaminated environment. Gas chromatography-mass spectrometry analysis revealed that JVH1 oxidized PFPS to a sulfoxide and then a sulfone prior to cleaving the C—S bond to form an alcohol and, presumably, a sulfinate from which sulfur could be extracted for growth. Four known dibenzothiophene-desulfurizing strains, including Rhodococcus sp. strain IGTS8, were all unable to cleave the C—S bond in PFPS but could oxidize PFPS to the sulfone via the sulfoxide. Conversely, JVH1 was unable to oxidize dibenzothiophene but was able to use a variety of alkyl sulfides, in addition to PFPS, as sole sulfur sources. Overall, PFPS is an excellent tool for isolating bacteria capable of cleaving subterminal C—S bonds within alkyl chains. The type of desulfurization displayed by JVH1 differs significantly from previously described reaction results.

Van Hamme, Jonathan D.; Fedorak, Phillip M.; Foght, Julia M.; Gray, Murray R.; Dettman, Heather D.

2004-01-01

284

Swept Away: Resuspension of Bacterial Mats Regulates Benthic-Pelagic Exchange of Sulfur  

Microsoft Academic Search

Filaments and extracellular material from colorless sulfur bacteria (Beggiatoa spp.) form extensive white sulfur mats on surface sediments of coastal, oceanic, and even deep-sea environments. These chemoautotrophic bacteria oxidize soluble reduced sulfur compounds and deposit elemental sulfur, enriching the sulfur content of surface sediment fivefold over that of deeper sediments. Laboratory flume experiments with Beggiatoa mats from an intertidal sandflat

Jonathan Grant; Ulrich V. Bathmann

1987-01-01

285

Appearance of compound cilia in the nasal mucosa of normal human subjects following acute, in vivo exposure to sulfur dioxide  

SciTech Connect

Electron microscopic examination of ultrathin sections of ciliated nasal epithelium obtained from seven normal, healthy human volunteers indicated increases in the prevalence of compound cilia following controlled, acute exposure to 0.75 ppm sulfur dioxide (SO/sub 2/). Morphometric analyses of the specimens confirmed a statistically significant association between SO/sub 2/ exposure and compounding of nasal epithelial cilia in four of the seven subjects. Concomitant freeze-fracture replicas prepared from these samples also revealed the occurrence of compound cilia with accompanying evidence of abnormal ciliary membrane ultrastructure in the nasal epithelium. These studies indicate that SO/sub 2/ may be implicated as a causative agent in ciliary compounding in the upper respiratory tract and that compound cilia represent a form of acquired ciliary defect which may serve as a readily quantifiable marker of epithelial injury.

Carson, J.L.; Collier, A.M.; Hu, S.C.; Smith, C.A.; Stewart, P.

1987-02-01

286

Combined chemical and microbiological removal of organic sulfur from coal  

SciTech Connect

The objective of this work is to investigate techniques for chemically converting the sulfur containing organic compounds in coal to compounds that can be treated microbiologically to remove the organically bound sulfur. The goal is to achieve an economically feasible mild chemical oxidation of the organic sulfur in a representative Illinois Basin coal by converting the sulfur to sulfoxides and sulfones; the carbon sulfur bond in the sulfoxides and sulfones would then be broken microbiologically and the sulfur removed from the coal as a sulfate. In initial studies, it was found that the combination treatments of sodium periodate/micorbial and hydrogen peroxide/microbial resulted in reductions of total sulfur or organic sulfur of 12--13%. 1 fig., 3 tabs.

Raphaelin, L.A.

1991-01-01

287

Combined chemical and microbiological removal of organic sulfur from coal  

SciTech Connect

The objective of this work is to investigate techniques for chemically converting the sulfur containing organic compounds in coal to compounds that can be treated microbiologically to remove the organically bound sulfur. The goal is to achieve an economically feasible mild chemical oxidation of the organic sulfur in a representative Illinois Basin coal by converting the sulfur to sulfoxides and sulfones; the carbon sulfur bond in the sulfoxides and sulfones would then be broken microbiologically and the sulfur removed from the coal as a sulfate. In initial studies, it was found that the combination treatments of sodium periodate/microbial and hydrogen peroxide/microbial resulted in reductions of total sulfur or organic sulfur of up to 20%. 4 tabs.

Raphaelian, L.A. (Institute of Gas Technology, Chicago, IL (United States))

1991-01-01

288

Phanerozoic cycles of sedimentary carbon and sulfur.  

PubMed

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

Garrels, R M; Lerman, A

1981-08-01

289

Online diode-array UV spectroscopy of sulfur and nitrogen compounds  

NASA Astrophysics Data System (ADS)

On-line real-time monitoring of the gas-phase concentrations of sulfur containing molecules such as sulfur dioxide (SO2), hydrogen sulfide (H2S), carbon disulfide (CS2) and nitrogen containing molecules such as nitric oxide (NO), nitrogen dioxide (NO2), nitrous oxide (N2O) and ammonia (NH3) is of major importance in pollution monitoring and reduction and in the optimization of many gas-phase industrial processes. A UV optimized non-solarizing fiber-optic based diode-array analyzer system utilizing a 10,000 hour MTBF Xenon pulsed source has been developed and proven on-line. An on-board chemometric prediction engine allows for the simultaneous multi-component analysis of measured spectra of sample gases in real-time. Fiber-optic coupling of the analyzer to the gas flow cell housed within the sampling system allows intrinsically safe measurement to be carried out on samples gases at temperatures up to 310 C and pressures to 60 barg. Detection sensitivity down to ppm levels have been realized including such measurement applications as NH3, NO and H2S monitoring.

Driver, Richard D.; Stein, Israel M.

1999-12-01

290

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

NASA Technical Reports Server (NTRS)

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

Demello, William Zamboni

1992-01-01

291

Relationship between corrosion and the biological sulfur cycle: A review  

SciTech Connect

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

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

2000-04-01

292

40 CFR 60.104 - Standards for sulfur oxides.  

Code of Federal Regulations, 2010 CFR

...by volume (dry basis) of sulfur dioxide (SO2 ) at zero percent...300 ppm by volume of reduced sulfur compounds and 10 ppm by volume...fluid catalytic cracking unit catalyst regenerator: (1) With...reduce SO2 emission, maintain sulfur oxides emissions...

2010-07-01

293

40 CFR 60.104 - Standards for sulfur oxides.  

Code of Federal Regulations, 2010 CFR

...by volume (dry basis) of sulfur dioxide (SO 2 ) at zero...300 ppm by volume of reduced sulfur compounds and 10 ppm by volume...fluid catalytic cracking unit catalyst regenerator: (1) With an...SO 2 emission, maintain sulfur oxides emissions...

2009-07-01

294

TOTAL SULFUR DEPOSITION (WET+DRY) FROM THE ATMOSPHERE  

EPA Science Inventory

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

295

TOTAL SULFUR DEPOSITION (WET+DRY) FROM THE ATMOSHERE  

EPA Science Inventory

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

296

Fluorine-Induced Chemiluminescence Detection of Biologically Methylated Tellurium, Selenium, and Sulfur Compounds and Methyldithiocarbhydrazide as a Formaldehyde Derivatization Reagent  

NASA Astrophysics Data System (ADS)

The first part of this dissertation describes capillary chromatography coupled to a fluorine-induced chemiluminescence detector as a sensitive method by which biologically methylated metalloids can be determined in the presence of high concentrations of potentially interfering molecules. With a wide linear range and excellent sensitivity, this method was applied to the detection of dimethyl selenide (DMSe), dimethyl diselenide (DMDSe), and dimethyl telluride (DMTe), often found in biological environments in the presence of interfering methylated sulfur gases, such as methanethiol, dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide. Detection limits for DMSe, DMDSe, and DMTe were 30, 9, and 7 picograms, respectively. This DMTe detection limit is the lowest reported to date for a volatile tellurium gas. A variety of selenium-resistant bacteria emitted mixtures of methylated sulfur/selenium gases when dosed with inorganic selenium salts in the presence of sulfur containing growth media. One of the gases detected was dimethyl selenenyl sulfide, CH_3SeSCH _3, reported here for the first time in headspace above microorganisms. In addition, this detector responded to reduced phosphorus compounds such as phosphine. The detection limit for this compound was 2.8 picograms. Detection limits for alkylated phosphines trimethyl and triethyl phosphine were 0.5 and 17 picograms respectively, based on the relative response of these compounds compared to dimethyl sulfide. This method can be used for the simultaneous determination of methylated sulfur, selenium, tellurium compounds found in biological systems. Part II of this dissertation describes work with methyldithiocarbhydrazide, a compound that has been synthesized for use as a derivatization reagent to capture formaldehyde in the gas phase. Chosen for its ability to react in a manner similar to 2,4-dinitrophenylhydrazine, this molecule was selected based on two structural characteristics: a hydrazine tag to react with and thereby capture carbonyls and a methyl sulfide group to allow for sensitive detection by fluorine-induced chemiluminescence. Although in the final analysis methyldithiocarbohydrazide failed as a successful means by which formaldehyde can be determined using gas chromatography in conjunction with fluorine-induced chemiluminescence, it did successfully derivatize formaldehyde in both solution and the gas phase without the need for low pH conditions.

Chasteen, Thomas Girard

1990-01-01

297

Relationship Between Corrosion and the Biological Sulfur Cycle: A Review  

Microsoft Academic Search

Sulfur and sulfur compounds can produce pitting, crevice corrosion, dealloying, stress corrosion cracking, and stress-oriented hydrogen-induced cracking of susceptible metals and alloys. Even though the metabolic by-products of the biological sulfur cycle are extremely corrosive, there are no correlations between numbers and types of sulfur-related organisms and the probability or rate of corrosion, Determination of specific mechanisms for corrosion caused

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

2000-01-01

298

Elemental sulfur in the gills of three species of clams containing chemoautotrophic symbiotic bacteria: a possible inorganic energy storage compound  

Microsoft Academic Search

Sulfur content and fine structure were studied for tissues of three species of clams, Lucinoma annulata, Calyptogena elongata and Lucina floridana, which inhabit sulfide-rich environments and whose gills harbor symbiotic sulfur bacteria. Lucinoma annulata and C. elongata were dredged from the Santa Barbara basin, California, USA, at a depth of 480 to 490 m, and Lucina floridana were dug from

R. D. Vetter

1985-01-01

299

Instrumental methods of analysis of sulfur compounds in synfuel process streams. Quarterly technical progress report, July-September 1984  

SciTech Connect

Task 1. Methods development for the speciation of the polysulfides. Work on this task has been completed in December 1983 and reported accordingly in DOE/PC/40783-T13. Task 2. Methods development for the speciation of dithionite and polythionates. Work on Task 2 has been completed in June 1984 and has been reported accordingly in DOE/PC/40783-T15. Task 3. Total accounting of the sulfur balance in representative samples of synfuel process streams. A systematic and critical comparison of results, obtained in the analysis of sulfur moieties in representative samples of coal conversion process streams, revealed the following general trends. (a) In specimens of high pH (9-10) and low redox potential (-0.3 to -0.4 volt versus NHE) sulfidic and polysulfidic sulfur moieties predominate. (b) In process streams of lower pH and more positive redox potential, higher oxidation states of sulfur (notably sulfate) account for most of the total sulfur present. (c) Oxidative wastewater treatment procedures by the PETC stripping process convert lower oxidation states of sulfur into thiosulfate and sulfate. In this context, remarkable similarities were observed between liquefaction and gasification process streams. However, the thiocyanate present in samples from the Grand Forks gasifier were impervious to the PETC stripping process. (d) Total sulfur contaminant levels in coal conversion process stream wastewater samples are primarily determined by the abundance of sulfur in the coal used as starting material than by the nature of the conversion process (liquefaction or gasification). 13 references.

Jordan, J.; Talbott, J.

1984-01-01

300

Inhibition of methane oxidation by volatile sulfur compounds (CH3SH and CS2) in landfill cover soils.  

PubMed

Methanethiol and carbon disulphide were investigated for their ability to inhibit methane oxidation in two landfill cover soils. Methanethiol was found to be a competitive inhibitor, and at concentrations occurring in landfills, both these VSCs (volatile sulfur compounds) had inhibitory effects on the methane oxidation rates. Analysis of the phospholipid fatty acid contents in the soils indicated that type I-methanotrophs were more affected than type II. These effects of VSCs on methane oxidation are likely to have implications both for the establishment and the selectivity of a methane oxidizing microflora in landfills. PMID:11720266

Börjesson, G

2001-08-01

301

Sulfuric acid as autocatalyst in the formation of sulfuric acid.  

PubMed

Sulfuric acid can act as a catalyst of its own formation. We have carried out a computational investigation on the gas-phase formation of H(2)SO(4) by hydrolysis of SO(3) involving one and two water molecules, and also in the presence of sulfuric acid and its complexes with one and two water molecules. The hydrolysis of SO(3) requires the concurrence of two water molecules, one of them acting as a catalyzer, and our results predict an important catalytic effect, ranging between 3 and 11 kcal·mol(-1) when the catalytic water molecule is substituted by a sulfuric acid molecule or one of its hydrates. In these cases, the reaction products are either bare sulfuric acid dimer or sulfuric acid dimer complexed with a water molecule. There are broad implications from these new findings. The results of the present investigation show that the catalytic effect of sulfuric acid in the SO(3) hydrolysis can be important in the Earth's stratosphere, in the heterogeneous formation of sulfuric acid and in the formation of aerosols, in H(2)SO(4) formation by aircraft engines, and also in understanding the formation of sulfuric acid in the atmosphere of Venus. PMID:23198746

Torrent-Sucarrat, Miquel; Francisco, Joseph S; Anglada, Josep M

2012-12-26

302

Structural chemistry and geochemistry of silver-sulfur compounds: Critical Review  

SciTech Connect

Silver(1) binds strongly with sulfur(II-) in inorganic and organic species, resulting in picomolal aqueous dissolved concentrations. For sulfur species found in the environment, Ag(I)-S(II) bonding forms a linear di-coordinate arrangement, -S-Ag-S-, which results in long zigzag chains in inorganic (minerals) and organic (thiolate) complexes. Silver(I) forms the neutral complex AgHS{sup 0} at low concentration of S(II-) and Ag(I). Polynuclear complexes form in solution above micromolal concentrations of S(II-). Silver(I) polysulfides may be significant at elevated S(II-). A number of organic mercaptans (thiols) are found in anoxic sediments in nanomolal to micromolal levels and these can act as ligands for Ag(I). The surprisingly limited, known properties of Ag(I) complexes (thiolates) of environmental mercaptans are reviewed. In these thiolate complexes in the solid phase, single crystal X-ray diffraction shows that the -S(R)-Ag-S(R)- chains condense to form sheets that further link through silver-silver interactions to create a network, or slab of silver and sulfur atoms. From nuclear magnetic resonance spectroscopic evidence, zigzag chains also form in the solution phase and aggregate in a random manner to form colloids, which are the predominant form of Ag(I) in solution. The most crucial and important aspect of Ag(I) thiolate chemistry is the rapid exchange of Ag(I) among thiolates. This process is a mechanism whereby Ag(I) can transfer onto, or off, particulate materials or the cells of an organism. Silver(I) thiolates also react rapidly with H{sub 2}S or HS{sup {minus}} as ligands to form Ag{sub 2}S, but the reverse process is poor because of the high aqueous insolubility and stability of A{sub 2}S{sub s}. This reaction represents a possible final fate for any Ag(I) thiolate formed in natural waters, as well as any Ag(I)-S(II-) species.

Bell, R.A.; Kramer, J.R. [McMaster Univ., Hamilton, Ontario (Canada)

1999-01-01

303

Methionine metabolism: major pathways and enzymes involved and strategies for control and diversification of volatile sulfur compounds in cheese.  

PubMed

For economical reasons and to accommodate current market trends, cheese manufacturers and product developers are increasingly interested in controlling cheese flavor formation and developing new flavors. Due to their low detection threshold and diversity, volatile sulfur compounds (VSCs) are of prime importance in the overall flavor of cheese and make a significant contribution to their typical flavors. Thus, the control of VSCs formation offers considerable potential for industrial applications. This paper gives an overview of the main VSCs found in cheese, along with the major pathways and key enzymes leading to the formation of methanethiol from methionine, which is subsequently converted into other sulfur-bearing compounds. As these compounds arise primarily from methionine, the metabolism of this amino acid and its regulation is presented. Attention is focused in the enzymatic potential of lactic acid bacteria (LAB) that are widely used as starter and adjunct cultures in cheese-making. In view of industrial applications, different strategies such as the enhancement of the abilities of LAB to produce high amounts and diversity of VSCs are highlighted as the principal future research trend. PMID:23320908

Martínez-Cuesta, María Del Carmen; Peláez, Carmen; Requena, Teresa

2013-01-01

304

Heterologous Production of Methionine-?-Lyase from Brevibacterium linens in Lactococcus lactis and Formation of Volatile Sulfur Compounds? †  

PubMed Central

The conversion of methionine to volatile sulfur compounds (VSCs) is of great importance in flavor formation during cheese ripening and is the focus of biotechnological approaches toward flavor improvement. A synthetic mgl gene encoding methionine-?-lyase (MGL) from Brevibacterium linens BL2 was cloned into a Lactococcus lactis expression plasmid under the control of the nisin-inducible promoter PnisA. When expressed in L. lactis and purified as a recombinant protein, MGL was shown to degrade l-methionine as well as other sulfur-containing compounds such as l-cysteine, l-cystathionine, and l-cystine. Overproduction of MGL in recombinant L. lactis also resulted in an increase in the degradation of these compounds compared to the wild-type strain. Importantly, gas chromatography-mass spectrometry analysis identified considerably higher formation of methanethiol (and its oxidized derivatives dimethyl disulfide and dimethyl trisulfide) in reactions containing either purified protein, whole cells, or cell extracts from the heterologous L. lactis strain. This is the first report of production of MGL from B. linens in L. lactis. Given their significance in cheese flavor development, the use of lactic acid bacteria with enhanced VSC-producing abilities could be an efficient way to enhance cheese flavor development.

Hanniffy, Sean B.; Philo, Mark; Pelaez, Carmen; Gasson, Michael J.; Requena, Teresa; Martinez-Cuesta, M. C.

2009-01-01

305

Process for removing sulfur from sulfur-containing gases  

SciTech Connect

This patent describes a process for reducing the level of sulfur in a sulfur dioxide-containing gas. It comprises: preparing an aqueous slurry comprising a calcium alkali together with a calcium-reactive silica or alumina which are present in amounts sufficient to allow for the formation of a sulfur dioxide-absorbing component which includes a calcium silicate or calcium aluminate; heating the slurry to a temperature between about 40{degrees} and about 200{degrees} C. to facilitate in the formation of the sulfur dioxide-absorbing component; contacting the gas with the slurry in a manner sufficient to allow for the absorption of sulfur dioxide by the absorbing component; and separating the absorbing component in the form of spent solids from the gas.

Rochelle, G.T.; Jozewicz, W.

1990-06-05

306

Process for removing sulfur from sulfur-containing gases  

SciTech Connect

This patent describes a process for reducing the level of sulfur dioxide in a sulfur dioxide- containing gas. It comprises preparing an aqueous slurry comprising a calcium alkali together with a calcium-reactive silica or alumina, the calcium alkali and calcium-reactive silica or alumina being introduced into the slurry in a form consisting essentially of a high calcium fly ash, which are present in amounts sufficient to allow for the formation of a sulfur dioxide-absorbing component which includes a calcium silicate or calcium aluminate; heating the slurry to a temperature between about 50{degrees} and 200{degrees} C. for between about 0.1 and about 24 hours to facilitate in the formation of the sulfur dioxide-absorbing component; contacting the gas with the slurry in a manner sufficient to allow for the absorption of sulfur dioxide by the absorbing component; and separating the absorbing component in the form of spent solids from the gas.

Rochelle, G.T.; Chang, J.C.S.

1991-09-10

307

Process for removing sulfur from sulfur-containing gases  

SciTech Connect

This patent describes a process for reducing the level of sulfur dioxide in a sulfur dioxide- containing gas. It comprises preparing an aqueous slurry comprising a calcium alkali together with a calcium-reactive silica or alumina which are present in amounts sufficient to allow for the formation of a sulfur dioxide-absorbing component which includes a calcium silicate or calcium aluminate; heating the slurry to a temperature between about 120{degrees} and 180{degrees} C. to facilitate in the formation of the sulfur dioxide-absorbing component; contacting the gas with the slurry in a manner sufficient to allow for the absorption of sulfur dioxide by the absorbing component; and separating the absorbing component in the form of spent solids from the gas.

Jozewicz, W.; Chang, J.C.S.; Sedman, C.B.; Brna, T.G.; Rochelle, G.T.

1991-09-10

308

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

SciTech Connect

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

Jaakkola, J.J.; Vilkka, V.; Marttila, O.; Jaeppinen, P.H.; Haahtela, T. (South Karelia Allergy and Environment Institute, Espoo (Finland))

1990-12-01

309

Ru(III)-based compounds with sulfur donor ligands: synthesis, characterization, electrochemical behaviour and anticancer activity.  

PubMed

In recent years, Ru(iii) complexes have emerged as a new class of effective anticancer agents against tumors that proved to be resistant to all other chemotherapeutic drugs currently in clinical use. To extend our previous studies on metal complexes containing sulfur-donor ligands, we report here on the synthesis and characterization, by means of several spectroscopic and analytical techniques, some [Ru(RSDT)(3)] and [Ru(2)(RSDT)(5)]Cl complexes with dithiocarbamato ligands derived from methyl/ethyl/tert-butyl esters of sarcosine. Their electrochemical behaviour was also studied by cyclic voltammetry. All the complexes were tested for their cytotoxicity on a panel of human tumor cell lines showing highly significant antitumor activity. The chemical and biological properties of the newly synthesized complexes, were compared with those of [Ru(DMDT)(3)] and [Ru(2)(DMDT)(5)]Cl species (DMDT = N,N-dimethyldithiocarbamate) whose chemical (not biological) characterization has been already reported in literature. PMID:19153618

Giovagnini, Lorena; Sitran, Sergio; Castagliuolo, Ignazio; Brun, Paola; Corsini, Maddalena; Zanello, Piero; Zoleo, Alfonso; Maniero, Annalisa; Biondi, Barbara; Fregona, Dolores

2008-12-21

310

21 CFR 184.1095 - Sulfuric acid.  

Code of Federal Regulations, 2013 CFR

...sulfur dioxide (SO2 ) with oxygen and mixing the resultant sulfur trioxide (SO3 ) with water, or by reacting nitric oxide (NO) with sulfur dioxide and water. (b) The ingredient meets the specifications of the âFood...

2013-04-01

311

Demonstrating Allotropic Modifications of Sulfur.  

ERIC Educational Resources Information Center

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

McCarty, Jillian L.; Dragojlovic, Veljko

2002-01-01

312

Quantification of trace volatile sulfur compounds in milk by solid-phase microextraction and gas chromatography-pulsed flame photometric detection.  

PubMed

Volatile sulfur compounds have been reported to be responsible for the sulfurous off-flavors generated during the thermal processing of milk; however, their analysis has been a challenge due to their high reactivity, high volatility, and low sensory threshold. In this study, reactive thiols were stabilized and the volatile sulfur compounds in milk were extracted by headspace solid-phase microextraction, and analyzed by gas chromatography and pulsed-flame photometric detection. Calibration curves for 7 sulfur-containing compounds were constructed in milk by the standard addition technique. Raw, pasteurized, and UHT milk samples with various fat contents were analyzed. Compared with raw and pasteurized samples, UHT milk contained substantially higher concentrations of hydrogen sulfide, methanethiol, carbon disulfide, dimethyl trisulfide, and di-methyl sulfoxide. The high odor activity values calculated for methanethiol and dimethyl trisulfide suggested that these 2 compounds, in addition to di-methyl sulfide reported in a previous study, could be the most important contributors to the sulfurous note in UHT milk. PMID:16840607

Vazquez-Landaverde, P A; Torres, J A; Qian, M C

2006-08-01

313

A new perspective on the nature of ''organic'' sulfur in coal  

SciTech Connect

It is generally assumed that the sulfur in coal is distributed among organic sulfur, sulfatic sulfur, and pyritic sulfur compounds. ASTM D-2492 which lists the forms of sulfur in coal also assumes that three forms are present--sulfatic, pyritic, and organic sulfur. The organic sulfur value of coal is derived as the difference between the total sulfur content of coal and the amount of pyritic plus sulfatic sulfur, i.e., any form of sulfur that is not pyritic or sulfatic sulfur would be counted as organic sulfur. The organic sulfur is generally perceived to occur in covalently bonded C-S compounds like thiophenes, thioehters, and bisthiothers (disulfides). In this paper, the authors present a new perspective on the nature of organic sulfur in coal and suggest that the organic sulfur fraction in pristine coal contains sulfur in the form of a coal-polysulfide complex which, in some coals, may constitute in excess of 50% of the organic sulfur fraction. Experimental evidence using solvent extraction studies (under conditions that will allow the extraction of amorphous sulfur form) and geochemical approaches is presented below supporting the concept of this new polysulfide sulfur form in the ''organic'' sulfur fraction of coal. If this is true, then research and development efforts to remove the so-called organic sulfur components in coal must take into account this factor, especially since the elemental sulfur or the polysulfide sulfur can react with alkyl aromatic structures in coal creating new thiophenic sulfur compounds from which it is very difficult to excise the sulfur.

Narayan, R.; Kullerud, G.; Wood, K.V. (Coal Research Center, Purdue Univ., West Lafayette, IN (US))

1988-06-01

314

Theoretical studies of the marine sulfur cycle  

NASA Technical Reports Server (NTRS)

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

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

1985-01-01

315

Effect of a variety of Chinese herbs and an herb-containing dentifrice on volatile sulfur compounds associated with halitosis: An in vitro analysis  

Microsoft Academic Search

Background: The principal components of halitosis are volatile sulfur compounds (VSCs) such as hydrogen sulfide, methyl mercaptan, and dimethylsulfide or compounds such as butyric acid, propionic acid, putrescine, and cadaverine.Objective: The aim of this study was to evaluate the effect of Chinese herbs on VSCs in vitro.Methods: Saliva samples from volunteers were used as the source for the evaluation of

Ming-yu Li; Jun Wang; Zhu-ting Xu

2010-01-01

316

Characterization of a sulfur-regulated cyanobacterial gene similar to thiosulfate sulfur transferase (rhodanese)  

SciTech Connect

A number of soluble and membrane polypeptides are induced when cells of the cyanobacterium Anacystis nidulans R2 are deprived of sulfate. The gene encoding an abundant 33.5 kDa polypeptide, only present in sulfur starved cells, has been isolated and sequenced. The transcript from this gene becomes very abundant after sulfur deprivation and the deduced amino acid sequence shows homology to the sequence of thiosulfate sulfur transferase (rhodanese) from bovine liver. Furthermore, the protein appears to have a short NH{sub 2}-terminal presequence with characteristics of bacterial signal sequences, suggesting that it may be located in the periplasmic space. Deletion analysis of the thiosulfate sulfur transferase gene is currently in progress and the possible physiological role of this protein in the utilization of sulfur containing compounds will be discussed.

Laudenbach, D.E.; Ehrhardt, D.; Grossman, A.R. (Carnegie Institute of Washington, Stanford, CA (USA))

1989-04-01

317

A case study involving allergic reactions to sulfur-containing compounds including, sulfite, taurine, acesulfame potassium and sulfonamides.  

PubMed

A case study is reported whereby an individual with known sulfite and sulfonamide allergies develops hypersensitivity to taurine above a threshold level as well as to the non-nutritive sweetener acesulfame potassium, compounds that are not normally associated with allergic reactions. Sulfites, sulfonamides, taurine and acesulfame potassium all contain a SO3 moiety. Challenge tests provide evidence for the hypersensitivities to taurine and acesulfame potassium. The subject is also allergic to thiuram mix and thimerosal, sulfur containing compounds, as well as to various food products. This may be the first case where hypersensitivities to taurine and acesulfame potassium have been documented and reported. Several mechanistic explanations are provided for the untoward reactions to taurine and acesulfame potassium. PMID:24262485

Stohs, Sidney J; Miller, Mark J S

2014-01-01

318

Post-SL9 Sulfur Photochemistry on Jupiter  

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

319

Sulfur deactivation of fatty ester hydrogenolysis catalysts  

SciTech Connect

Trace organosulfur compounds present as natural impurities in oleochemical feedstocks may lead to activation of copper-containing catalysts applied for hydrogenolysis of esters toward fatty alcohols. In this paper, the sulfur deactivation of Cu/SiO{sub 2} and Cu/ZnO/SiO{sub 2} catalysts was studied in the liquid-phase hydrogenolysis of methyl palmitate. The rate of deactivation is fast and increases as a function of the sulfur-containing compound present: octadecanethiol {approx} dihexadecyl disulfide < benzyl isothiocyanate < methyl p-toluene sulfonate < dihexadecyl sulfide < dibenzothiophene. The rapid deactivation is caused by the fact that sulfur is quantitatively removed from the reaction mixture and because mainly surface sulfides are formed under hydrogenolysis conditions. The life time of a zinc-promoted catalyst is up to two times higher than that of the Cu/SiO{sub 2} catalyst, most likely due to zinc surface sulfide formation. The maximum sulfur coverage obtained after full catalyst deactivation with dibenzothiophene and dihexadecyl sulfide--the sulfur compounds that cause the fastest deactivation--may be as low as 0.07. This is due to the fact that decomposition of these compounds as well as the hydrogenolysis reaction itself proceeds on ensembles of copper atoms. Catalyst regeneration studies reveal that activity cannot be regained by reduction or combined oxidation/reduction treatments. XRD, TPR, and TPO results confirm that no distinct bulk copper or zinc sulfide or sulfate phases are present.

Brands, D.S.; U-A-Sai, G.; Poels, E.K.; Bliek, A. [Univ. of Amsterdam (Netherlands). Dept. of Chemical Engineering] [Univ. of Amsterdam (Netherlands). Dept. of Chemical Engineering

1999-08-15

320

Instrumental methods of analysis of sulfur compounds in synfuel process streams. Quarterly technical progress report, October-December 1982  

SciTech Connect

The general objective is to develop dependable and accurate instrumental analysis methods for the determination of sulfur moieties. These will include polysulfides, dithionite and polythionates. Calorimetric procedures (thermometric titrations, injection enthalpimetry) and electroanalytical techniques (voltammetry, coulometric analysis, etc.) will be used. The complete speciation of sulfur will be undertaken in representative synfuel process stream samples. Total sulfidic sulfur has been quantitated with the aid of diffusion currents engendered by the anodic depolarization of the dropping mercury electrode. Classical chemical reactions involving polythionates were surveyed as to their applicability to analytical determinations by Direct Injection Enthalpimetry (DIE). Reactions included polythionate decomposition by sulfide precipitation with mercuric chloride, silver nitrate, and thallows nitrate; polythionate oxidation, cyanolysis, and complexation with aquopentaammine cobalt (+3) chloride. An analysis of two H-Coal sour water samples was undertaken using thermochemical, electrochemical and classical methods. The various methods yielded consistent sulfidic and polysulfidic sulfur levels. This internal consistency substantiated the accuracy of the findings.

Jordan, J.; Stahl, J.; Yakupkovic, J.

1983-01-01

321

Instrumental methods of analysis of sulfur compounds in synfuel process streams. Quarterly technical progress report, January-March 1984  

SciTech Connect

Task 1. Methods development for the speciation of the polysulfides. Work on this task has been completed in December 1983 and reported accordingly in DOE/PC/40783-T13. Task 2. Methods development for the speciation of dithionite and polythionates. Work is in progress on the polarography of the polythionates. Results will be presented in a forthcoming Quarterly Report. Task 3. Total accounting of the sulfur balance in representative samples of synfuel process streams. Two aqueous samples emanating from different stages of the Lummus Process were analyzed. As expected, total sulfur content was low, viz., 0.006 M and 0.001 M. Concentrations of sulfidic sulfur, polysulfidic sulfur, thiosulfate, sulfite, trithionate, tetrathionate, and pentathionate were less than 0.001 M each. 5 references, 3 tables.

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

1984-04-01

322

Effect of sulfur-containing compounds on growth of Methanosarcina barkeri in defined medium  

SciTech Connect

Methanosarcina barkeri Fusaro (DSM 804) could grow on methanol in a mineral medium containing cysteine or thiosulfate as the sole sulfur source. Optimum growth occurred at cysteine concentrations of 1 to 2.8 mM and at thiosulfate concentrations of 2.5 to 5 mM. No inhibition of growth was observed even when these concentrations were doubled in the culture medium. Under the optimum cysteine and thiosulfate concentrations, the generation times of the organism were about 8 to 10 and 10 to 12 h, respectively, giving a cell yield of about 0.14 to 0.17 and 0.08 to 0.11 g (dry weight)/g of methanol consumed. The organism metabolized cysteine and thiosulfate during growth, giving rise to sulfide in the culture medium. H/sub 2/S evolution from cysteine and thiosulfate was catalyzed by two enzymes, namely cysteine desulfhydrase and thiosulfate reductase, respectively, as revealed by enzyme assay in the crude cell-free extract of the organism.

Mazumder, T.K.; Nishio, N.; Fukuzaki, S.; Nagai, S.

1986-10-01

323

87 Removal of sulfur compounds from natural gas by adsorption on Ag-exchanged zeolites for PEFC  

Microsoft Academic Search

The newly-developed desulfurization materials based on Ag-zeolites performed the high sulfur adsorption capacities from a pipeline natural gas at ambient temperature in the presence of moisture. The sulfur adsorption capacity of Ag(Na)-Y, was higher than those of the other adsorbents and was not to be easily influenced by water content in the natural gas. Clear color change was observed by

Shigeo Satokawa; Yuji Kobayashi; Hiroshi Fujiki

2003-01-01

324

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

SciTech Connect

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

Tyagi, R.D.; Blais, J.F.; Deschenes, L. [Universite du Quebec (Canada)

1994-09-01

325

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

NASA Astrophysics Data System (ADS)

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

Rumsey, Ian Cooper

326

Photodissociation Studies of Sulfur Oxides.  

National Technical Information Service (NTIS)

The detailed reaction dynamics of several gas phase polyatomic systems has been established in this research at the Department of Chemistry at the University of Puerto Rico. Real time dynamics of sulfur monoxide photoelimination reactions have been studie...

B. R. Weiner

1996-01-01

327

Sodium Sulfur Technology Program NASTEC.  

National Technical Information Service (NTIS)

The NaSTEC program focuses on developing currently available sodium sulfur cells for use in space applications and investigating the operational parameters of the cells. The specific goals of the program are to determine the operational parameters and ver...

B. Highley W. A. Somerville

1992-01-01

328

Radiolysis of sulfuric acid, sulfuric acid monohydrate, and sulfuric acid tetrahydrate and its relevance to Europa  

Microsoft Academic Search

We report laboratory studies on the 0.8MeV proton irradiation of ices composed of sulfuric acid (H2SO4), sulfuric acid monohydrate (H2SO4·H2O), and sulfuric acid tetrahydrate (H2SO4·4H2O) between 10 and 180K. Using infrared spectroscopy, we identify the main radiation products as H2O, SO2, (S2O3)x, H3O+, HSO4-, and SO42-. At high radiation doses, we find that H2SO4 molecules are destroyed completely and that

M. J. Loeffler; R. L. Hudson; M. H. Moore; R. W. Carlson

2011-01-01

329

Process for production of synthesis gas with reduced sulfur content  

DOEpatents

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

Najjar, Mitri S. (Hopewell Junction, NY); Corbeels, Roger J. (Wappingers Falls, NY); Kokturk, Uygur (Wappingers Falls, NY)

1989-01-01

330

Metabolism of Reduced Methylated Sulfur Compounds in Anaerobic Sediments and by a Pure Culture of an Estuarine Methanogen †  

PubMed Central

Addition of dimethylsulfide (DMS), dimethyldisulfide (DMDS), or methane thiol (MSH) to a diversity of anoxic aquatic sediments (e.g., fresh water, estuarine, alkaline/hypersaline) stimulated methane production. The yield of methane recovered from DMS was often 52 to 63%, although high concentrations of DMS (as well as MSH and DMDS) inhibited methanogenesis in some types of sediments. Production of methane from these reduced methylated sulfur compounds was blocked by 2-bromoethanesulfonic acid. Sulfate did not influence the metabolism of millimolar levels of DMS, DMDS, or MSH added to sediments. However, when DMS was added at ?2-?M levels as [14C]DMS, metabolism by sediments resulted in a 14CH4/14CO2 ratio of only 0.06. Addition of molybdate increased the ratio to 1.8, while 2-bromoethanesulfonic acid decreased it to 0, but did not block 14CO2 production. These results indicate the methanogens and sulfate reducers compete for DMS when it is present at low concentrations; however, at high concentrations, DMS is a “noncompetitive” substrate for methanogens. Metabolism of DMS by sediments resulted in the appearance of MSH as a transient intermediate. A pure culture of an obligately methylotrophic estuarine methanogen was isolated which was capable of growth on DMS. Metabolism of DMS by the culture also resulted in the transient appearance of MSH, but the organism could grow on neither MSH nor DMDS. The culture metabolized [14C]-DMS to yield a 14CH4/14CO2 ratio of ?2.8. Reduced methylated sulfur compounds represent a new class of substrates for methanogens and may be potential precursors of methane in a variety of aquatic habitats.

Kiene, Ronald P.; Oremland, Ronald S.; Catena, Anthony; Miller, Laurence G.; Capone, Douglas G.

1986-01-01

331

Thermophilic Carbon-Sulfur-Bond-Targeted Biodesulfurization  

PubMed Central

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

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

1997-01-01

332

Emission of sulfur from Lake Ontario sediments  

Microsoft Academic Search

Calculations indicate that about 6.0 x 10⁵ kg of sulfur is released annually from Lake Ontario sediments. This constitutes about 1% of the annual sulfur input into the sediments and is insignificant compared to the total sulfur that cycles annually through the lake. The sulfur released from the sediments is enriched in ³²S with the result that the sulfur in

J. O. Nriagu; R. D. Coker

1976-01-01

333

Sonoluminescence of elementary sulfur melt  

NASA Astrophysics Data System (ADS)

The sonoluminescence of liquid sulfur has been observed for temperatures of 120-180°C. The sonoluminescence intensity of the sulfur melt is 109 photons/s at 120°C. As the temperature increases, the luminescence intensity decreases nonmonotonically, a maximum is observed at 160-175°C, and cavitation and luminescence cease at 180°C. The dependence obtained correlates with the temperature dependence of the viscosity of the sulfur melt. The sonoluminescence spectrum obtained with a resolution of 10 nm for 130-150°C contains one band with ?max = 560 nm, the emitter of which is likely an (S+)* ion. When the melt is saturated with argon, the sonoluminescence intensity increases by an order of magnitude; in this case, the spectral band shape changes only slightly. The results confirm the “electric” theory of multibubble sonoluminescence. In the process of the sonolysis of the sulfur melt, biradical fragments are formed in cavitation bubbles consisting of sulfur molecules, which initially have the form of cyclooctasulfur S8. These fragments can enter into the melts and can be involved in various chemical reactions. This circumstance makes it possible to recommend ultrasonic activation for reactions of sulfurization of hydrocarbons.

Abdrakhmanov, A. M.; Sharipov, G. L.; Rusakov, I. V.; Akhmetova, V. R.; Bulgakov, R. G.

2007-06-01

334

Sulfur metabolism in Beggiatoa alba.  

PubMed Central

The metabolism of sulfide, sulfur, and acetate by Beggiatoa alba was investigated under oxic and anoxic conditions. B. alba oxidized acetate to carbon dioxide with the stoichiometric reduction of oxygen to water. In vivo acetate oxidation was suppressed by sulfide and by several classic respiratory inhibitors, including dibromothymoquinone, an inhibitor specific for ubiquinones. B. alba also carried out an oxygen-dependent conversion of sulfide to sulfur, a reaction that was inhibited by several electron transport inhibitors but not by dibromothymoquinone, indicating that the electrons released from sulfide oxidation were shuttled to oxygen without the involvement of ubiquinones. Intracellular sulfur stored by B. alba was not oxidized to sulfate or converted to an external soluble form under aerobic conditions. On the other hand, sulfur stored by filaments of Thiothrix nivea was oxidized to extracellular soluble oxidation products, including sulfate. Sulfur stored by filaments of B. alba, however, was reduced to sulfide under short-term anoxic conditions. This anaerobic reduction of sulfur was linked to the endogenous oxidation of stored carbon and to hydrogen oxidation.

Schmidt, T M; Arieli, B; Cohen, Y; Padan, E; Strohl, W R

1987-01-01

335

The fate of sulfur during rapid pyrolysis of scrap tires.  

PubMed

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. PMID:24238304

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

2014-02-01

336

Organic sulfur metabolisms in hydrothermal environments.  

PubMed

Sulfur is central to the metabolisms of many organisms that inhabit extreme environments. While biotic and abiotic cycling of organic sulfur compounds has been well documented in low-temperature anaerobic environments, cycling of organic sulfur in hydrothermal environments has received less attention. Recently published thermodynamic data have been used to estimate aqueous alkyl thiol and sulfide activities in deep-sea hydrothermal systems. Here we use geochemical mixing models to predict fluid compositions that result from mixing end-member hydrothermal fluid from the East Pacific Rise with bottom seawater. These fluid compositions are combined with estimates of methanethiol and dimethylsulfide activities to evaluate energy yields for potential organic sulfur-based metabolisms under hydrothermal conditions. Aerobic respiration has the highest energy yields (over -240 kJ/mol e?) at lower temperature; however, oxygen is unlikely to persist at high temperatures, restricting aerobic respiration to mesophilic communities. Nitrite reduction to N? has the highest energy yields at higher temperatures (greater than ?40 °C). Nitrate and nitrite reduction to ammonium also yield significant energy (up to -70 kJ/mol e?). Much lower, but still feasible energy yields are calculated for sulfate reduction, disproportionation, and reduction with H?. Organic compound family and the activity of methanethiol and dimethylsulfide were less important than metabolic strategy in determining overall energy yields. All metabolic strategies considered were exergonic within some portion of the mixing regime suggesting that organic sulfur-based metabolisms may be prevalent within deep-sea hydrothermal vent microbial communities. PMID:22469147

Rogers, Karyn L; Schulte, Mitchell D

2012-07-01

337

Volatile organic sulfur compounds as biomarkers complementary to methane: Infrared absorption spectroscopy of CH 3SH enables insitu measurements on Earth and Mars  

Microsoft Academic Search

As universal products of biological processes, volatile organic sulfur compounds such as methyl mercaptan (CH3SH) may be essential in the search for signs of life on Mars and in exoplanet atmospheres. Methyl mercaptan is implicated in the origin of life at sites of low-temperature hydrothermal activity driven by serpentinization. Serpentinization may occur on Mars, in icy satellite oceans, and in

Steve Vance; Lance E. Christensen; Christopher R. Webster; Keeyoon Sung

2011-01-01

338

Volatile organic sulfur compounds as biomarkers complementary to methane: Infrared absorption spectroscopy of CH3SH enables insitu measurements on Earth and Mars  

Microsoft Academic Search

As universal products of biological processes, volatile organic sulfur compounds such as methyl mercaptan (CH3SH) may be essential in the search for signs of life on Mars and in exoplanet atmospheres. Methyl mercaptan is implicated in the origin of life at sites of low-temperature hydrothermal activity driven by serpentinization. Serpentinization may occur on Mars, in icy satellite oceans, and in

Steve Vance; Lance E. Christensen; Christopher R. Webster; Keeyoon Sung

2011-01-01

339

Special features in the effect of sulfur compounds in a gaseous flow of combustion products containing seawater salts on the thermal fatigue fracture of operating turbine blades  

Microsoft Academic Search

Since the actual operating conditions of ship gas turbines are characterized bythe presence of seawater salts entering the engine from the atmosphere, as well as an increased content of sulfur compounds in the gas flow, in the present investigation we have studied the combined action of these corrosive components on the thermal cycling endurance of turbine blades. The concentrations of

G. N. Tret'yachenko; É. P. Kosygin

1979-01-01

340

The evaluation of recovery rate associated with the use of thermal desorption systems for the analysis of atmospheric reduced sulfur compounds (RSC) using the GC\\/PFPD method  

Microsoft Academic Search

In this work, the recovery rate (RR) of preconcentration technique was examined using a combination of the Peltier cooling (PC) and thermal desorption (TD) system for the gas chromatographic (GC) analysis of reduced sulfur compounds (RSC) in air. The possible loss or gain of analytes resulting from the use of the PC\\/TD system was estimated by analyzing equimolar standards (10ppm)

Ki-Hyun Kim; Do-Weon Ju; Sang-Woo Joo

2005-01-01

341

Identification of the chemical form of sulfur compounds in the Japanese pink coral (Corallium elatius) skeleton using ?-XRF/XAS speciation mapping.  

PubMed

The distributions and chemical forms of sulfur compounds in the skeleton of Japanese pink coral (Corallium elatius) were investigated using X-ray spectroscopic techniques combined with micro-focused soft X-ray radiation. Microscopic X-ray fluorescence/soft X-ray photoabsorption (?-XRF/XAS) speciation mapping clarified that sulfate is the primary species in the coral skeleton, with minor amounts of organic sulfur, whereas both sulfate and organic sulfur coexist in coenenchyme. Analysis of the post-edge region of the XAS spectra confirmed that sulfate ions in the coral skeleton are mainly in the form of gypsum-like inorganic sulfate substituting for the carbonate ions in the calcite skeleton. The sulfate concentration was negatively correlated with the magnesium concentration and positively correlated with that of phosphorus. Speciation mapping of sulfate in the coral skeleton showed clear fluctuations with sulfate concentrations being higher at dark bands, whereas the small amount of organic sulfur had unclear dark/bright bands. These results suggest that the little organic sulfur that is present is contained in the organic matter embedded in the biocrystal of coral skeleton. PMID:24727132

Tamenori, Yusuke; Yoshimura, Toshihiro; Luan, Nguyen Trong; Hasegawa, Hiroshi; Suzuki, Atsushi; Kawahata, Hodaka; Iwasaki, Nozomu

2014-05-01

342

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

NASA Astrophysics Data System (ADS)

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

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

2002-08-01

343

Process and apparatus for recovery of sulfur from ammonia containing acid gas streams  

Microsoft Academic Search

This patent describes a Claus process for the recovery of sulfur, the steps comprising: passing a first stream containing hydrogen sulfide, sulfur dioxide, and ammonia through a low temperature Claus catalytic conversion zone and depositing elemental sulfur and ammonium compounds on catalyst therein; deriving a regeneration stream from the Claus process and regenerating the resulting laden catalyst therewith vaporizing sulfur

1987-01-01

344

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

PubMed

The reaction of iron sulfide (FeS) with H2S in water, in presence of CO2 under anaerobic conditions was found to yield H2 and a variety of organic sulfur compounds, mainly thiols and small amounts of CS2 and dimethyldisulfide. The same compounds were produced when H2S was replaced by HCl, in the H2S-generating system FeS/HCl/CO2. The identification of the products was confirmed by GC-MS analyses and the incorporation of H2 in the organic sulfur compounds was demonstrated by experiments in which all hydrogen compounds were replaced by deuterium compounds. Generation of H2 and the synthesis of thiols were both dependent upon the relative abundance of FeS and HCl or H2S, i.e. the FeS/HCl- or FeS/H2S-proportions. Whether thiols or CS2 were formed as the main products depended also on the FeS/HCl-ratio: All conditions which create a H2 deficiency were found to initiate a proportional increase in the amount of CS2. The quantities of H2 and thiols generated depended on temperature: the production of H2 was significantly accelerated from 50 degrees C onward and thiol synthesis above 75 degrees C. The yield of thiols increased with the amount of FeS and HCl (H2S), given a certain FeS/HCl-ratio and a surplus of CO2. A deficiency of CO2 results in lower thiol synthesis. The end product, pyrite (FeS2), was found to appear as a silvery granular layer floating on the aqueous surface. The identity of the thiols was confirmed by mass spectrometry, and the reduction of CO2 demonstrated by the determination of deuterium incorporation with DCl and D2O. The described reactions can principally proceed under the conditions comparable to those obtaining around submarine hydrothermal vents, or the global situation about 4 billion years ago, before the dawn of life, and could replace the need for a reducing atmosphere on the primitive earth. PMID:11536750

Heinen, W; Lauwers, A M

1996-04-01

345

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

NASA Astrophysics Data System (ADS)

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

Heinen, Wolfgang; Lauwers, Anne Marie

1996-04-01

346

Early diagenesis of sulfur in estuarine sediments: the role of sedimentary humic and fulvic acids  

NASA Astrophysics Data System (ADS)

Sediments were collected from anoxic, organic-rich estuarine muds of St. Andrew Bay, Florida to assess the early diagenetic pathways leading to the formation of organic and inorganic sedimentary sulfide species. Abundance and sulfur isotopic composition were determined for dissolved sulfide, dissolved sulfate, elemental sulfur, acid-volatile sulfide, chromium-reducible sulfur, fulvic acid-sulfur, humic acid-sulfur, and residual organic (protokerogen) sulfur. Fulvic acid-sulfur, elemental sulfur, and acid-volatile sulfides are the initial sinks for dissolved sulfide and form before pyrite. Subsequently, two-thirds of fulvic acid-sulfur are lost. A fraction of fulvic acid-sulfur is transferred to higher molecular weight compounds such as humic acids and protokerogens, but most of the sulfides are recycled back to the porewaters. Enrichments in the isotopic composition of organic sulfur fractions, relative to pyrite and acid-volatile sulfides, suggest a contribution of detrital biosynthetic sulfur to the organic sulfur pool. Accounting for the biosynthetic component in fulvic acid-sulfur, the isotopic similarities between elemental sulfur, acid-volatile sulfides, and fulvic acid-sulfur suggest isotopic exchange in the uppermost 3 cm of sediment. Isotopic mass calculations suggest an additional isotopic fractionation takes place during recycling of sulfide released from fulvic acids and elemental sulfur by bacterial disproportionation of polysulfides and elemental sulfur. Subsequent precipitation of recycled, 34S-depleted sulfide as pyrite reconciles the consistent depletion in 34S of pyrite-S relative to all other sedimentary sulfide species.

Brüchert, Volker

1998-05-01

347

Combined chemical and microbiological removal of organic sulfur from coal  

SciTech Connect

The objective of this work is to investigate techniques for chemically converting the sulfur containing organic compounds in coal to compounds that can be treated microbiologically to remove the organically bound sulfur. The goal is to achieve an economically feasible mild chemical oxidation of the organic sulfur in a representative Illinois Basin coal by converting the sulfur to sulfoxides and sulfones; the carbon sulfur bond in the sulfoxides and sulfones would then be broken microbiologically and the sulfur removed from the coal as a sulfate. During this quarter, samples of IBE-107, ground to {minus}200 mesh, were oxidized with hydrogen peroxide, potassium permanganate, and sodium periodate for three hours and treated microbiologically with the bacterium, IGTS8. A number of blanks were also prepared. Of the forty-one samples in this initial study, 27 are ready for analysis and 14 are presently being treated microbiologically. 1 tab.

Raphaelian, L.A. (Institute of Gas Technology, Chicago, IL (USA))

1990-01-01

348

Smaller sulfur molecules promise better lithium-sulfur batteries.  

PubMed

The lithium-sulfur battery holds a high theoretical energy density, 4-5 times that of today's lithium-ion batteries, yet its applications have been hindered by poor electronic conductivity of the sulfur cathode and, most importantly, the rapid fading of its capacity due to the formation of soluble polysulfide intermediates (Li(2)S(n), n = 4-8). Despite numerous efforts concerning this issue, combatting sulfur loss remains one of the greatest challenges. Here we show that this problem can be effectively diminished by controlling the sulfur as smaller allotropes. Metastable small sulfur molecules of S(2-4) were synthesized in the confined space of a conductive microporous carbon matrix. The confined S(2-4) as a new cathode material can totally avoid the unfavorable transition between the commonly used large S(8) and S(4)(2-). Li-S batteries based on this concept exhibit unprecedented electrochemical behavior with high specific capacity, good cycling stability, and superior rate capability, which promise a practicable battery with high energy density for applications in portable electronics, electric vehicles, and large-scale energy storage systems. PMID:23101502

Xin, Sen; Gu, Lin; Zhao, Na-Hong; Yin, Ya-Xia; Zhou, Long-Jie; Guo, Yu-Guo; Wan, Li-Jun

2012-11-14

349

Characterization and quantification of the oxides of sulfur and nitrogen and associated compounds in their gaseous, aerosol, and dissolved states  

SciTech Connect

The needs and problems associated with the characterization and quantification of the oxides of sulfur and nitrogen and associated compounds in their gaseous, aerosol, and dissolved states are discussed. Illustrations are given of the techniques in present usage for the determination of the substances of interest to investigators concerned with the effects of air pollutants on the terrestrial ecosystem. The value and utility of the newer techniques employing real time continuous instrumentation are presented and compared with the more traditional approaches utilizing sampling collection. A plea is made to provide resources for data reduction especially in order to obtain constructive utilization of continuous instrumentation. It is asserted that real time instrumentation is best utilized during campaign measurement programs where short time resolution is required and that collection techniques still have a place, especially in long term monitoring efforts. Special attention was directed at, and the problems highlighted that are associated with, the utilization of the real time instruments available for the flame photometric determination of the oxides of sulfur and the chemiluminescent measurement of the oxides of nitrogen. The newer methods proposed for their use in the determination of sulfate and nitric acid respectively are presented. The difficulties associated with the determination of nitrate are enunciated and attention focused on the problems of obtaining a sample due to the variation of the vapor pressure of gaseous nitric acid and ammonia above solid ammonium nitrate which is in association with an acidic aerosol containing sulfate. The utility of measurements of the composition of rainwater is discussed in light of its application to determine the mechanisms through which rain derives its chemical composition.

Newman, L

1980-05-01

350

40 CFR 60.4360 - How do I determine the total sulfur content of the turbine's combustion fuel?  

Code of Federal Regulations, 2013 CFR

...determined using total sulfur methods described in...Alternatively, if the total sulfur content of the gaseous...D5504, or D6228, or Gas Processors Association...which measure the major sulfur compounds, may be...

2013-07-01

351

Human impact on the atmospheric sulfur balance  

NASA Astrophysics Data System (ADS)

The paper reviews the development in our understanding of the atmospheric part of the global sulfur cycle, including the role played by C.-G. Rossby and his colleagues in the 1950s, and presents a brief assessment of the current knowledge. Measurements of the concentrations of sulfur compounds in air, precipitation, ice cores and sea water during the past 25years, together with recent development in three-dimensional tracer transport modeling, have resulted in a reasonably consistent picture of the burdens and fluxes of the main sulfur compounds in the atmosphere. It is clear that man's activities, in particular the burning of fossil fuels, are having a large impact on the atmospheric sulfur balance. Even on a global scale, the man-made emissions of gaseous sulfur compounds are likely to be two to three times as large as the natural sources. In and around the most heavily industrialized regions this ratio exceeds ten over extended areas. Nevertheless, there are several important issues that need to be resolved. Some of these are directly linked to the urgent problem of reducing the uncertainty in the estimate of direct and, in particular, indirect climate forcing due to man-made sulfate aerosols. One such issue is the magnitude of the wet scavenging of SO2 and aerosol sulfate during upward transport into and within the free troposphere in connection with convective and frontal cloud systems which has a decisive influence on the sulfate concentrations in the upper troposphere. Another uncertain process is the rate of oxidation of SO2 in cloud droplets and on aerosol particles. A fundamental question that remains to be answered is to what degree man-made sulfur emissions have increased the number of aerosol particles that can act as cloud condensation nuclei.

Rodhe, Henning

1999-02-01

352

Human impact on the atmospheric sulfur balance  

NASA Astrophysics Data System (ADS)

The paper reviews the development in our understanding of the atmospheric part of the global sulfur cycle, including the role played by C.-G. Rossby and his colleagues in the 1950s, and presents a brief assessment of the current knowledge. Measurements of the concentrations of sulfur compounds in air, precipitation, ice cores and sea water during the past 25years, together with recent development in three-dimensional tracer transport modeling, have resulted in a reasonably consistent picture of the burdens and fluxes of the main sulfur compounds in the atmosphere. It is clear that man's activities, in particular the burning of fossil fuels, are having a large impact on the atmospheric sulfur balance. Even on a global scale, the man-made emissions of gaseous sulfur compounds are likely to be two to three times as large as the natural sources. In and around the most heavily industrialized regions this ratio exceeds ten over extended areas. Nevertheless, there are several important issues that need to be resolved. Some of these are directly linked to the urgent problem of reducing the uncertainty in the estimate of direct and, in particular, indirect climate forcing due to man-made sulfate aerosols. One such issue is the magnitude of the wet scavenging of SO2 and aerosol sulfate during upward transport into and within the free troposphere in connection with convective and frontal cloud systems which has a decisive influence on the sulfate concentrations in the upper troposphere. Another uncertain process is the rate of oxidation of SO2 in cloud droplets and on aerosol particles. A fundamental question that remains to be answered is to what degree man-made sulfur emissions have increased the number of aerosol particles that can act as cloud condensation nuclei.

Rodhe, Henning

1999-01-01

353

Intermediate sulfur oxidation state compounds in the euxinic surface sediments of the Dvurechenskii mud volcano (Black Sea)  

NASA Astrophysics Data System (ADS)

The deep Black Sea is known to be depleted in electron-acceptors for sulfide oxidation. This study on depth distributions of sulfur species (S(II), S(0), Sn2-, SO32-, SO32-, SO42-) in the Dvurechenskii mud volcano, a cold seep situated in the permanently anoxic eastern Black Sea basin (Sorokin Trough, 2060 m water depth), showed remarkable concentrations of sulfide oxidation products. Sulfite concentrations of up to 11 ?mol L-1, thiosulfate concentrations of up to 22 ?mol L-1, zero-valent sulfur concentrations of up to 150 ?mol L-1 and up to five polysulfide species were measured in the upper 20 cm of the sediment. Electron-acceptors found to be available in the Dvurechenskii mud volcano (DMV) for the oxidation of hydrogen sulfide to sulfide oxidation intermediates are iron-minerals, and probably also reactive manganese phases. Up to 60 ?mol g-1 of reactive iron-minerals and up to 170 ?mol L-1 dissolved iron was present in the central summit with the highest fluid upflow and fresh mud outflow. Thus, the source for the oxidative power in the DMV are reactive iron phases extruded with the mud from an ancient source in the deeply buried sediments, leading to the formation of various sulfur intermediates in comparably high concentrations. Another possible source of sulfide oxidation intermediates in DMV sediments could be the formation of zero-valent sulfur by sulfate dependent anaerobic microbial oxidation of methane followed by disproportionation of zero-valent sulfur. Sulfide oxidation intermediates, which are produced by these processes, do not reach thermodynamic equilibrium with rhombic sulfur, especially close to the active center of the DMV due to a short equilibration time. Thus, mud volcano sediments, such as in the DMV, can provide oxidizing niches even in a highly reduced environment like the abyssal part of the Black Sea.

Lichtschlag, Anna; Kamyshny, Alexey; Ferdelman, Timothy G.; deBeer, Dirk

2013-03-01

354

Elemental sulfur at the pyrite surfaces: speciation and quantification  

NASA Astrophysics Data System (ADS)

A new methodology, based on sulfur extraction with appropriate organic solvents and analyses using gas chromatography coupled with mass spectroscopy, is developed to identify and quantify elemental sulfur forms at pyrite surfaces. The comparison between hexane and methanol extraction allows the determination of two types of S 8 elemental sulfur: a fraction residing alone on the pyrite surface, and another fraction associated with hydrophilic superficial compounds like sulfate.

Toniazzo, V.; Mustin, C.; Portal, J. M.; Humbert, B.; Benoit, R.; Erre, R.

1999-04-01

355

Sulfur chemistry in dense interstellar clouds  

NASA Technical Reports Server (NTRS)

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

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

1982-01-01

356

Sulfuric acid in the Venus clouds.  

NASA Technical Reports Server (NTRS)

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

Sill, G. T.

1972-01-01

357

Reaction of dialkyl disulfides with elemental sulfur  

SciTech Connect

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

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

1986-06-01

358

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

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

359

Sulfur capture in combination bark boilers  

SciTech Connect

A review of sulfur dioxide emission data for eight combination bark boilers in conjunction with the sulfur contents of the fuels reveals significant sulfur capture ranging from 10% to over 80% within the solid ash phase. Wood ash characteristics similar to activated carbon as well as the significant wood ash alkali oxide and carbonate fractions are believed responsible for the sulfur capture. Sulfur emissions from combination bark-fossil fuel firing are correlated to the sulfur input per ton of bark or wood residue fired.

Someshwar, A.V.; Jain, A.K. (National Council of the Paper Industry for Air and Stream Improvement, Gainesville, FL (United States))

1993-07-01

360

A new perspective on the nature of organic sulfur in coal  

SciTech Connect

In this paper the authors present a new perspective on the nature of organic sulfur in coal and suggests that the organic sulfur fraction in pristine coal contains sulfur in the form of a coal-polysulfide complex which, in some coals, may constitute in excess of 50% of the organic sulfur fraction. Under suitable chemical/biological environments, this sulfur complex would give rise to free elemental sulfur. The sulfur, thus set free could get dispersed through the coal matrix and would be present in the amorphous form. The amorphous form arises when sulfur precipitates from solution as a result of chemical-reactions, especially when it first appears in the collodial state. This sulfur would be insoluble in organic solvents and would not be detected by X-ray diffraction. Experimental evidence using solvent extraction studies (under conditions that will allow the extraction of amorphous sulfur form) and geochemical approaches is presented below supporting the concept of this new polysulfide sulfur form in the organic sulfur fraction of coal. If this is true, then research and development efforts to remove the so-called organic sulfur components in coal must take into account this factor, especially since the elemental sulfur or the polysulfide sulfur can react with alkyl aromatic structures in coal creating new thiophenic sulfur compounds from which it is very difficult to excise the sulfur.

Narayan, R.; Kullerud, G.; Wood, K.V. (Purdue Univ., West Lafayette, IN (USA))

1988-01-01

361

MICROBIAL DEGRADATION OF NITROGEN, OXYGEN AND SULFUR HETEROCYCLIC COMPOUNDS UNDER ANAEROBIC CONDITIONS: STUDIES WITH AQUIFER SAMPLES  

EPA Science Inventory

The potential for anaerobic biodegradation of 12 heterocyclic model compounds was studied. Nine of the model compounds were biotransformed in aquifer slurries under sulfate-reducing or methanogenic conditions. The nitrogen and oxygen heterocyclic compounds were more susceptible t...

362

MICROBIAL DEGRADATION OF NITROGEN, OXYGEN, AND SULFUR HETEROCYCLIC COMPOUNDS UNDER ANAEROBIC CONDITIONS: STUDIES WITH AQUIFER SAMPLES  

EPA Science Inventory

The potential for anaerobic biodegradation of 12 heterocyclic model compounds was studied. ine of the model compounds were biotransformed in aquifer slurries under sulfate-reducing or methanogenic conditions. he nitrogen and oxygen heterocyclic compounds were more susceptible to ...

363

Sulfur as a lunar resource  

NASA Astrophysics Data System (ADS)

Results of a study of seven lava samples from the Apollo 17 landing site are presented. The samples are polished thin sections. Backscattered electron images on an SEM were used to process gray-level spectra to separate the triolite crystals; these were verified with the X-ray spectra. It is found that the quantities of sulfur to be gained by thermal processing are strongly influenced by duration of heating and sample processing; effective processing may require heating with active thermochemical reaction to extract the sulfur as H2S or SO2. The speciation of the sulfur gases evolved might be controlled by manipulation of temperature, total pressure, and partial gas pressures of the extraction environment.

Heiken, G.; Vaniman, D.; Hawkins, H.

364

Comparative application of sulfur chemiluminescence detection in gas and supercritical fluid chromatography  

Microsoft Academic Search

Sulfur chemiluminescence detection (SCD) for the determination of sulfur-containing compounds in gas chromatography (GC) and supercritical fluid chromatography (SFC) is described. The detector is based on the chemiluminescence reaction of ozone with sulfur monoxide which is produced in an H2\\/O2 reducing flame from sulfur-containing analytes. High selectivity over nonsulfur-containing species has been achieved for a number of mercaptans and sulfur-containing

W. F. Sye; Z. X. Zhao; M. L. Lee

1992-01-01

365

Effect of Changes in Sulfur Compounds on Stability and Gelation of Caseins and of Sterile Concentrated Milk1  

Microsoft Academic Search

Strong disulfide reducing agents Na~SQ and NaBH~ increased nonprotein nitrogen (NPN) in the casein complex from sterile concentrated milk. The sulfur-containing reducing agents mercaptoethanol, thioglycolate, and eysteine reduced the disulfide linkages and decreased stabilities to Ca\\

S. Nakai; H. K. Wilson; E. O. Herreid

1965-01-01

366

Microbial desulfurization of a crude oil middle-distillate fraction: Analysis of the extent of sulfur removal and the effect of removal on remaining sulfur  

SciTech Connect

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

Grossman, M.J.; Lee, M.K.; Prince, R.C.; Garrett, K.K. [Exxon Research and Engineering Co., Annandale, NJ (United States); George, G.N.; Pickering, I.J. [Stanford Synchrotron Radiation Lab., CA (United States)

1999-01-01

367

Microbial desulfurization of a crude oil middle-distillate fraction: analysis of the extent of sulfur removal and the effect of removal on remaining sulfur.  

PubMed

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

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

1999-01-01

368

Inhibition by polyphenolic phytochemicals and sulfurous compounds of the formation of 8-chloroguanosine mediated by hypochlorous acid, human myeloperoxidase, and activated human neutrophils.  

PubMed

Hypochlorous acid (HOCl) produced by myeloperoxidase (MPO) of activated neutrophils can react with nucleic acid bases to form chlorinated nucleosides such as 8-chloroguanosine (Cl-Guo). Chlorination is enhanced by nicotine. We investigated the effects of various natural antioxidants including polyphenolic phytochemicals on the formation of Cl-Guo by HOCl in the presence and the absence of nicotine. Polyphenols, including catechins, curcumin, resveratrol, silibinin, and sulfurous compound ?-lipoic acid, were found to inhibit both HOCl- and human MPO-induced Cl-Guo formation dose-dependently. Among the test compounds, (-)-epigallocatechin gallate (EGCG) showed the strongest inhibitory effect. Cl-Guo formation, mediated by activated human neutrophils in the presence of nicotine, was inhibited by EGCG, silibinin, and ?-lipoic acid. These results suggest that polyphenols and sulfurous compounds have the potential to inhibit the induction of nucleobase damage mediated by chlorination, with possible application to reducing DNA damage associated with inflammation and cigarette-smoke inhalation. PMID:23221717

Nakano, Toshiki; Masuda, Mitsuharu; Suzuki, Toshinori; Ohshima, Hiroshi

2012-01-01

369

Images of Jupiter's Sulfur Ring.  

PubMed

Images of the ring of singly ionized sulfur encircling Jupiter obtained on two successive nights in April 1979 show that the ring characteristics may change dramatically in approximately 24 hours. On the first night the ring was narrow and confined to the magnetic equator inside Io's orbit. On the second it was confined symmetrically about the centrifugal symmetry surface and showed considerable radial structure, including a "fan" extending to Io's orbit. Many of the differences in the ring on the two nights can be explained in terms of differences in sulfur plasma temperature. PMID:17809102

Pilcher, C B

1980-01-11

370

Sulfuric Acid on Europa's Surface and the Radiolytic Sulfur Cycle  

Microsoft Academic Search

Galileo infrared spectra of Europa's surface show distorted water bands that have been attributed to hydrated evaporite salts (McCord et al., J. Geophys. Res. 104, 11827, 1999) or to the scattering properties of ice (Dalton and Clark, Bull. Am. Astron. Soc. 30, 1081, 1998). Using new laboratory spectra, we show that hydrated sulfuric acid can explain Europa's spectra and further

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

1999-01-01

371

Sulfur enrichment of humic substances in a Delaware salt marsh sediment core  

NASA Astrophysics Data System (ADS)

Humic sulfur, operationally defined as the sulfur extracted with humic substances in 0. l N NaOH solution, comprises up to 51% of the total sulfur inventory in a sediment core taken from a Delaware Spartina alterniflora marsh. Pyrite sulfur is the next largest fraction, except at the near-surface sediments, where zerovalent sulfur concentrations are significant. X-ray photoelectron spectroscopy indicates that the humic sulfur consists of sulfoxides or sulfones and, in a more reduced state, organic sulfides and/or organic polysulfides. A subsurface decrease in the humic acid C:S atomic ratio to 56 ± 2 suggests that the upper 4 cm of marsh sediment is the locus for humic sulfur formation. S. alterniflora detritus and microbial biomass cannot fully account for observed sulfur enrichment of humic C:S atomic ratios. Therefore, the enrichment of humic substances by sulfur is probably via reaction of reduced sulfur compounds with organic matter. A humic sulfur formation rate of 10.6 ?mol S · cm -3 · a -1 is calculated for the surface sediments and leads to an areal production of 18 ?mol S · cm -2 · a -1 of humic sulfur. Humic sulfur formation and preservation is enhanced by the limited availability of iron for the rapid precipitation of iron sulfide minerals and the apparent resistance of organic sulfur compounds towards reoxidation to sulfate, especially in the upper 9 cm of marsh sediment where inorganic sulfur compounds are rapidly oxidized.

Ferdelman, Timothy G.; Church, Thomas M.; Luther, George W., III

1991-04-01

372

The Speciation of Sulfur in an Ocean on Europa  

NASA Technical Reports Server (NTRS)

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

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

2002-01-01

373

THERMODYNAMICS OF THE GEOCHEMICAL CYCLE OF SULFUR IN SEDIMENTARY BASINS  

Microsoft Academic Search

Sulfur is involved in many reactions governing the evolution of petroleum systems, from the sulfurization of functionalized lipids by bacterially produced H2S during early diagenesis (Sinninghe Damsté et al., 1989) to the reactions occurring during thermochemical sulfate reduction (Goldstein and Aizenshtat, 1994; Machel, 2001). Recent efforts in calculating thermodynamic properties of organic compounds (Helgeson et al., 1998; Richard and Helgeson,

Laurent RICHARD; Rakhim UTEYEV

374

40 CFR 60.104 - Standards for sulfur oxides.  

Code of Federal Regulations, 2013 CFR

...a flare of process upset gases or fuel gas that is released to the...cause the discharge of any gases into the atmosphere from any Claus sulfur recovery plant containing...volume of reduced sulfur compounds and 10 ppm by volume...

2013-07-01

375

Stable sulfur and carbon isotope investigations of pore-water and solid-phase compounds in sediments of the Chapopote Asphalt Volcano, southern Gulf of Mexico  

NASA Astrophysics Data System (ADS)

During R/V Meteor cruise M67 2a/b (March-April 2006) to the Asphalt Volcanoes of the southern Gulf of Mexico two gravity cores were retrieved from the central depression of the Chapopote Knoll which contained viscous oil/asphalt a few meters below the sediment surface. Also several push cores were taken with the remotely operated vehicle (ROV) QUEST at sites where oil/asphalt reached closely below the sediment surface. From these cores solid-phase and pore-water samples were taken for on-board and subsequent shore-based analyses. Together with a core taken from a background site which is not influenced by asphalt/oil seepage these sediment and pore water samples are currently subject to detailed analyses of (1) the stable sulfur isotopic composition of both dissolved (sulfate and sulfide) and solid-phase (iron monosulfides, pyrite) sulfur compounds, and (2) the composition and stable carbon isotopic signatures of hydrocarbon gases. The major aims of these investigations are to identify whether and to which extent the upward migration of oil, asphalt and gas (1) stimulates biogeochemical processes and turn-over rates, and (2) influences the stable sulfur isotopic signatures of both dissolved and solid phase sulfur compounds. Furthermore, we seek to determine the potential of these - possibly unusual - stable sulfur isotopic signals of solid-phase sulfides to reconstruct hydrocarbon seepage in older geological records and to elucidate how the composition and the stable carbon isotopic signatures of the hydrocarbon gases are altered by the action of typical chemosynthetic communities thriving at these sites.

Wilhelm, T.; Bruechert, V.; Pape, T.; Schubotz, F.; Kasten, S.

2007-05-01

376

Parameters Influencing Sulfur Speciation in Environmental Samples Using Sulfur K-Edge X-Ray Absorption Near-Edge Structure  

PubMed Central

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).

Pongpiachan, Siwatt; Thumanu, Kanjana; Kositanont, Charnwit; Schwarzer, Klaus; Prietzel, Jorg; Hirunyatrakul, Phoosak; Kittikoon, Itthipon

2012-01-01

377

Formation of insoluble, nonhydrolyzable, sulfur-rich macromolecules via incorporation of inorganic sulfur species into algal carbohydrates  

NASA Astrophysics Data System (ADS)

The process of sulfur incorporation into organic matter was simulated in the laboratory by sulfurization of cell material of the prymnesiophyte alga Phaeocystis in sea water with inorganic polysulfides at 50°C. Flash pyrolysis of the residue, obtained after extraction and several hydrolysis steps, yielded mainly C 1-C 4 alkylbenzenes and C 1-C 4 alkylphenols and, in contrast to control and blank experiments, relatively high amounts of C 0-C 4 alkylthiophenes. The distribution of the thiophenes is very similar to that in pyrolysates of type II-S kerogens. The formation of high-molecular-weight sulfur-rich macromolecules co-occurs with a marked drop in the content of hydrolyzable carbohydrates. This indicates that sulfurization results in the preservation of algal carbohydrate carbon in a macromolecular structure composed of (poly)sulfidic cross-linked carbohydrate skeletons, which upon pyrolysis yields alkylthiophenes. Sulfurization of glucose under similar conditions resulted in the formation of a nonhydrolyzable, solid material, which yielded high amounts of organic sulfur compounds upon pyrolysis, mainly short-chain alkylthiophenes, although with a different distribution than that in the pyrolysate of the sulfurized algal material. The carbon numbers of these organic sulfur compounds extend beyond six, indicating that the length of the carbon skeleton of the pyrolysis products is not limited by the length of the carbon skeleton of the substrate. These results suggest that the sulfurization of carbohydrates may be an important pathway in the preservation of organic matter in euxinic depositional environments.

Kok, Marika D.; Schouten, Stefan; Sinninghe Damsté, Jaap S.

2000-08-01

378

Behavior of sulfur during coal pyrolysis  

USGS Publications Warehouse

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

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

1994-01-01

379

Sulfuric acid versus elemental sulfur as by-products. Final report  

Microsoft Academic Search

An economic comparison of sulfuric acid production and sulfur recovery processes was made on eastern coal feeds in this study. Sulfuric acid is the more attractive product whenever assured markets are available, on the basis of rail transportation of by-products. The capital cost is higher for a plant to recover the sulfur, and the product value is lower per unit

1978-01-01

380

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

SciTech Connect

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

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

2012-01-14

381

Effects of ursolic acid, betulin and sulfur-containing compounds on mucin release from airway goblet cells.  

PubMed

In this study, we investigated whether ursolic acid, betulin and 2 kinds of sulfur-containing compounds--NAC and MESNA--affect mucin release from airway goblet cells and compared the possible activities of these agents with the inhibitory action on mucin release by PLL and the stimulatory action by ATP. Confluent primary hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled using 3H-glucosamine for 24 h and chased for 30 min in the presence of varying concentrations of each agent to assess the effects on 3H-mucin release. The results were as follows: ursolic acid, betulin, MESNA and NAC increased mucin release (40-50 % above control) at the highest concentrations (10(-5) M-10(-3) M). We conclude that ursolic acid and betulin can stimulate mucin release by directly acting on airway mucin-secreting cells and suggest that these agents be further investigated for the possible use as mucoregulators in the treatment of chronic airway diseases. PMID:15643543

Lee, Choong Jae; Seok, Jeong Ho; Hur, Gang Min; Lee, Jae Heun; Park, Ji Sun; Seol, In Chan; Kim, Yun Hee

2004-12-01

382

The emission characteristics and the related malodor intensities of gaseous reduced sulfur compounds (RSC) in a large industrial complex  

NASA Astrophysics Data System (ADS)

In this study, the concentrations of major reduced sulfur compounds (RSC: H 2S, CH 3SH, DMS, CS 2 and DMDS) were determined from various emission sources located within the Ban-Wall (BW)/ Si-Hwa (SH) industrial complex in Ansan city, Korea. The measurement data were obtained from a total of 202 individual points at 77 individual companies during 2004-2005. The highest RSC concentration levels came most dominantly from H 2S (300 (mean) and 0.86 ppb (median)) followed by CS 2, while the results of CH 3, DMS, and DMDS are notably lower at the mean concentration levels of a few ppb. These data were evaluated further after being grouped into two different classification schemes: 9 industry sectors and 9 processing unit types. The strongest emissions of RSC, when evaluated among different industry sectors, are generally found from such industry types as leather, food, paper/pulp, as well as waste/sewage related ones. In contrast, when these RSC data are compared across different processing units, the highest values were seen most frequently from such units as junction boxes, aeration tanks, and settling tanks. The assessment of data in terms of relative contribution to malodor intensity showed that H 2S and CH 3SH are more important than others. The overall results of the present study suggest that information combining RSC speciation and types of anthropogenic activities may be used to distinguish the patterns of odorous pollution in areas affected by strong source processes.

Kim, Ki-Hyun; Jeon, Eui-Chan; Choi, Ye-Jin; Koo, Youn-Seo

383

Flavor precursors and sensory-active sulfur compounds in alliaceae species native to South Africa and South America.  

PubMed

Profiles of S-substituted cysteine flavor precursors were determined in 42 Alliaceae species native to South Africa and South America. It was found that the pool of cysteine derivatives present in these plants is remarkably very simple, with S-((methylthio)methyl)cysteine 4-oxide (marasmin) being the principal flavor precursor, typically accounting for 93-100% of the pool. Out of the other cysteine derivatives, only minor quantities of methiin were present in some species. The marasmin-derived thiosulfinate marasmicin (2,4,5,7-tetrathiaoctane 4-oxide), a major sensory-active compound of the freshly disrupted plants, was isolated, and its organoleptic properties were evaluated. Furthermore, sulfur-containing volatiles formed upon boiling of these alliaceous species were studied by GC-MS. The profile of the volatiles formed was relatively simple, with 2,3,5-trithiahexane and 2,4,5,7-tetrathiaoctane being the major components. Despite the traditional belief, ingestion of the marasmin-rich plants was always accompanied by development of a strong "garlic breath". We believe that especially several Tulbaghia species deserve to attract much greater attention from the food industry thanks to their pungent garlicky taste and unusual yet pleasant alliaceous smell. PMID:23331069

Kubec, Roman; Krej?ová, Petra; Mansur, Leví; García, Nicolás

2013-02-13

384

Swept away: resuspension of bacterial mats regulates benthic-pelagic exchange of sulfur.  

PubMed

Filaments and extracellular material from colorless sulfur bacteria (Beggiatoa spp.) form extensive white sulfur mats on surface sediments of coastal, oceanic, and even deep-sea environments. These chemoautotrophic bacteria oxidize soluble reduced sulfur compounds and deposit elemental sulfur, enriching the sulfur content of surface sediment fivefold over that of deeper sediments. Laboratory flume experiments with Beggiatoa mats from an intertidal sandflat (Nova Scotia) demonstrated that even slight erosion of sediment causes a flux of 160 millimoles of sulfur per square meter per hour, two orders of magnitude greater than the flux produced by sulfur transformations involving either sulfate reduction or sulfide oxidation by benthic bacteria. These experiments indicate that resuspension of sulfur bacterial mats by waves and currents is a rapid mechanism by which sediment sulfur is recycled to the water column. Benthic communities thus lose an important storage intermediate for reduced sulfur as well as a high-quality bacterial food source for benthic grazers. PMID:17793235

Grant, J; Bathmann, U V

1987-06-12

385

Swept Away: Resuspension of Bacterial Mats Regulates Benthic-Pelagic Exchange of Sulfur  

NASA Astrophysics Data System (ADS)

Filaments and extracellular material from colorless sulfur bacteria (Beggiatoa spp.) form extensive white sulfur mats on surface sediments of coastal, oceanic, and even deep-sea environments. These chemoautotrophic bacteria oxidize soluble reduced sulfur compounds and deposit elemental sulfur, enriching the sulfur content of surface sediment fivefold over that of deeper sediments. Laboratory flume experiments with Beggiatoa mats from an intertidal sandflat (Nova Scotia) demonstrated that even slight erosion of sediment causes a flux of 160 millimoles of sulfur per square meter per hour, two orders of magnitude greater than the flux produced by sulfur transformations involving either sulfate reduction or sulfide oxidation by benthic bacteria. These experiments indicate that resuspension of sulfur bacterial mats by waves and currents is a rapid mechanism by which sediment sulfur is recycled to the water column. Benthic communities thus lose an important storage intermediate for reduced sulfur as well as a high-quality bacterial food source for benthic grazers.

Grant, Jonathan; Bathmann, Ulrich V.

1987-06-01

386

Air Quality Criteria for Sulfur Oxides.  

ERIC Educational Resources Information Center

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

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

387

46 CFR 148.315 - Sulfur.  

Code of Federal Regulations, 2013 CFR

...This part applies to lump or coarse grain powder sulfur only. Fine-grained powder (âflowers of sulfurâ) may not be transported...lump or coarse grain powder sulfur has been completed, sulfur dust must be removed from the vessel's decks, bulkheads,...

2013-10-01

388

Sulfuric acid emissions from light duty vehicles  

Microsoft Academic Search

Systems used by the Office of Mobile Source Air Pollution Control of EPA to measure and analyze automotive sulfuric acid emissions are discussed. This system involved mixing the entire vehicle exhaust with dilution air in a dilution tunnel. Sulfuric acid samples are collected by passing a small portion of the dilute exhaust through Fluoropore filters. The sulfuric acid content of

J. H. Somers; R. Lawrence; C. E. Fett; T. M. Baines; R. J. Garbe

1976-01-01

389

SULFUR DIOXIDE SOURCES IN AK  

EPA Science Inventory

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

390

Atmospheric Atomic Sulfur Ion Reactions.  

National Technical Information Service (NTIS)

The apparent observation of atomic sulfur ions below 86 km in the ionosphere stimulates an interest in their possible production and loss processes. Toward this end we have measured the following reactions at 300K: S(+) + NO goes to NO(+) + S, for k = 4.2...

F. C. Fehsenfeld E. E. Ferguson

1972-01-01

391

Six new tin-sulfur containing compounds obtained under solvothermal conditions  

NASA Astrophysics Data System (ADS)

During explorative solvothermal syntheses six new compounds containing either the [Sn2S6]4- or the [SnS4]4- anion were obtained and structurally characterized: [Ni(1,2-dach)3]2Sn2S6·4H2O (1) (1,2-dach = trans-1,2-diaminocyclohexane), o-{[Ni(tepa)]2Sn2S6} (2) (tepa = tetraethylenepentamine), [Ni(peha)]2Sn2S6·H2O (3) (peha = pentaethylenehexamine), [Ni(aepa)]2Sn2S6 (4) (aepa = N-2-aminoethyl-1,3-propandiamine), [Co(dien)]2Sn2S6 (5) (dien = diethylenetriamine), and {[Mn(trien)]2SnS4} (trien = triethylenetetramine). In all compounds in-situ formed transition metal amine complexes act as charge compensating ligands or are bound to the thiostannate anions. Compound 2 is an orthorhombic polymorph of a recently published monoclinic compound. In compound 6 the very rare [Mn2N8S2] bi-octahedron is observed as main structural motif. This compound contains a one-dimensional chain which was also observed in a pseudo-polymorphic compound. The structures of all compounds are characterized by an extended hydrogen bonding network between S atoms of the anions and the H atoms of the amine ligands and/or water molecules.

Pienack, Nicole; Lühmann, Henning; Seidlhofer, Beatrix; Ammermann, Janina; Zeisler, Christoph; Danker, Felix; Näther, Christian; Bensch, Wolfgang

2014-07-01

392

Sulfur Isotope Distribution in Solfataras, Yellowstone National Park  

Microsoft Academic Search

Sulfur isotope data on hydrogen sulfide, native sulfur, and sulfates from acid hot-spring areas at Yellowstone National Park suggest that hydrogen sulfide oxidizes to sulfur abiologically, whereas sulfur undergoes biological oxidation to sulfuric acid. An exception occurs at Mammoth Hot Springs where hydrogen sulfide apparently undergoes biochemical oxidation to sulfur.

Robert Schoen; Robert O. Rye

1970-01-01

393

A potential source of atmospheric sulfur from penguin colony emissions  

NASA Astrophysics Data System (ADS)

Samples of fresh penguin excrements and lake sediments composed of aged penguin excrements were collected on an Antarctic Peninsula island. Gases emitted from these samples were collected and analyzed for volatile organosulfur compounds. No dimethyl sulfide (DMS) was found. However, dimethyl trisulfide (DMTS), dimethyl tetrasulfide (DMTTS), and dimethyl pentasulfide (DMPS) were found among the numerous organic compounds emitted from fresh penguin droppings. These sulfur compounds account for as mush as 13.5% of the emitted gases, but they have not been reported previously in atmospheric gases and therefore may represent a hitherto undetected source of atmospheric sulfur. To evaluate the potential contribution of this non-DMS biogenic source to the atmospheric sulfur reservoir at high southern latitudes, measurements of various chemical species in aerosols at several coastal Antarctic locations were analyzed and compared. The locations include Zhongshan Station (China) and Dumont D'Urville (France) in east Antarctica. Tentative calculations based on assumptions of similar aerosol sources and composition at these locations show that in areas downwind from large penguin colonies up to 5.5 × 10-5 nmol m-3 sulfur may be attributed to penguin emissions on a per-penguin basis. Depending on the size of penguin population at a given location, sulfur from this non-DMS source may account for 5-15% of the total non-sea-salt (nss) sulfur in these areas. Such high contributions may significantly impact the atmospheric sulfur burden and alter the sulfur budget in the high southern latitudes.

Xie, Zhou-Qing; Sun, Li-Guang; Wang, Jian-Jun; Liu, Bai-Zhan

2002-11-01

394

Sulfur-oxidizing Bacteria: A Novel Bioinoculant for Sulfur Nutrition and Crop Production  

Microsoft Academic Search

\\u000a Sulfur is an essential nutrient for plant growth as sulfur-deficient conditions cause severe losses in crop yield. Sulfur\\u000a nutrition has received little attention for many years, since fertilizers and atmospheric inputs have provided adequate amounts.\\u000a However, recent reductions in sulfur inputs from atmospheric depositions have resulted in a negative sulfur balance in agricultural\\u000a soils, making crop plants increasingly dependent on

R. Anandham; P. Indira Gandhi; M. SenthilKumar; R. Sridar; P. Nalayini; Tong-Min Sa

395

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

PubMed

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

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

2014-01-01

396

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

PubMed Central

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

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

2014-01-01

397

Determination of Volatile Sulfur Compounds in Beverage and Coffee Samples by Purge-and-Trap On-Line Coupling with a Gas Chromatography-Flame Photometric Detector  

Microsoft Academic Search

.  A sensitive and fast analytical method using purge-and-trap on-line coupling with gas chromatography was developed for the determination of trace volatile sulfur compounds including dimethyl sulfide (DMS), ethyl-methyl sulfide (EMS), and dimethyl disulfide (DMDS) in beverage and coffee samples. The analytes were purged for 12min from the sample by high purity nitrogen at a flow rate of 35KPa and preconcentrated

Liu Jiemin; Li Ning; Wen Meijuan; Jiang Guibin

2004-01-01

398

Effects of Sulfur Compounds and Other Air Pollutants on Soil and Ground Water.  

National Technical Information Service (NTIS)

This report deals with biological and chemical effects of air pollution (in particular, acidic and acidifying compounds and heavy metals) on soils, which are not intensively managed. The points covered will include: - Important physical and chemical prope...

B. Nihlgaard, G. Tyler, I. Nilsson

1984-01-01

399

Validation of high performance liquid chromatography methods for determination of bioactive sulfur compounds in garlic bulbs  

Microsoft Academic Search

High performance liquid chromatography (HPLC) methods for determination of organosulfur compounds (OSCs) before their enzymatic\\u000a decomposition and allicin in garlic were optimized and validated. Four ?-glutamyl peptides, 2 S-alk(en)yl cysteine sulfoxides, and 2 S-alk(en)yl cysteine were simply extracted with water, followed by the sensitive and selective determination of all compounds\\u000a in a single run using reverse phase HPLC. Allicin was

Miyoung Yoo; Sanghee Lee; Sangil Lee; Homoon Seog; Dongbin Shin

2010-01-01

400

Identification of Components of Electron Transport Chains in the Extremely Thermoacidophilic Crenarchaeon Metallosphaera sedula through Iron and Sulfur Compound Oxidation Transcriptomes? †  

PubMed Central

The crenarchaeal order Sulfolobales collectively contain at least five major terminal oxidase complexes. Based on genome sequence information, all five complexes are found only in Metallosphaera sedula and Sulfolobus tokodaii, the two sequenced Sulfolobales capable of iron oxidization. While specific respiratory complexes in certain Sulfolobales have been characterized previously as proton pumps for maintaining intracellular pH and generating proton motive force, their contribution to sulfur and iron biooxidation has not been considered. For M. sedula growing in the presence of ferrous iron and reduced inorganic sulfur compounds (RISCs), global transcriptional analysis was used to track the response of specific genes associated with these complexes, as well as other known and putative respiratory electron transport chain elements. Open reading frames from all five terminal oxidase or bc1-like complexes were stimulated on one or more conditions tested. Components of the fox (Msed0467 to Msed0489) and soxNL-cbsABA (Msed0500 to Msed0505) terminal/quinol oxidase clusters were triggered by ferrous iron, while the soxABCDD? terminal oxidase cluster (Msed0285 to Msed0291) were induced by tetrathionate and S0. Chemolithotrophic electron transport elements, including a putative tetrathionate hydrolase (Msed0804), a novel polysulfide/sulfur/dimethyl sulfoxide reductase-like complex (Msed0812 to Msed0818), and a novel heterodisulfide reductase-like complex (Msed1542 to Msed1550), were also stimulated by RISCs. Furthermore, several hypothetical proteins were found to have strong responses to ferrous iron or RISCs, suggesting additional candidates in iron or sulfur oxidation-related pathways. From this analysis, a comprehensive model for electron transport in M. sedula could be proposed as the basis for examining specific details of iron and sulfur oxidation in this bioleaching archaeon.

Auernik, Kathryne S.; Kelly, Robert M.

2008-01-01

401

Synthesis, Structure and Reactivity of Two-Coordinate Mercury Alkyl Compounds with Sulfur Ligands: Relevance to Mercury Detoxification  

PubMed Central

The susceptibility of two-coordinate mercury alkyl compounds of the type X–Hg–R (where X is a monodentate sulfur donor) towards protolytic cleavage has been investigated as part of ongoing efforts to obtain information relevant to understanding the mechanism of action of the organomercurial lyase, MerB. Specifically, the reactivity of the two-coordinate mercury alkyl compounds PhSHgR, [mimBut]HgR and {[HmimBut]HgR}+ (HmimBut = 2-mercapto-1-t-butylimidazole; R = Me, Et) towards PhSH was investigated, thereby demonstrating that the ability to cleave the Hg–C bond is very dependent on the nature of the system. For example, whereas the reaction of PhSHgMe with PhSH requires heating at 145 °C for several weeks to liberate CH4, the analogous reaction of PhSHgEt with PhSH leads to evolution of C2H6 over the course of 2 days at 100 °C. Furthermore, protolytic cleavage of the Hg–C bond by PhSH is promoted by HmimBut. For example, whereas the reaction of {[HmimBut]HgEt}+ with PhSH eliminates C2H6 at elevated temperatures, the protolytic cleavage occurs over a period of 2 days at room temperature in the presence of HmimBut. The ability of HmimBut to promote the protolytic cleavage is interpreted in terms of the formation of a higher coordinate species {[HmimBut]nHgR}+ that is more susceptible to Hg–C bond cleavage than is two-coordinate {[HmimBut]HgR}+. These observations support the notion that access to a species with a coordination number greater than two is essential for efficient activity of MerB.

Melnick, Jonathan G.; Yurkerwich, Kevin; Parkin, Gerard

2009-01-01

402

Determination of sulfur trioxide in engine exhaust.  

PubMed Central

Sulfur trioxide in the exhaust gas of an internal combustion engine is removed and concentrated by absorption in a solution of 80% isopropyl alcohol, which quantitatively absorbs it and inhibits the oxidation of any sulfur dioxide which may be absorbed. The absorbed sulfur trioxide (sulfuric acid) is determined by an absorption titration by using barium chloride as the titrant and thorin as the indicator. The sulfur dioxide content of the exhaust is measured continuously by means of a DuPont Model 411 ultraviolet photoanalyzer.

Arnold, D R

1975-01-01

403

Defluorination of organofluorine sulfur compounds by Pseudomonas sp. strain D2  

Microsoft Academic Search

Little is known of the potential for biodegradation of fluorinated sulfonates. Because of the apparent stability of fluorinated organics, their bioactivity, and their potential for accumulation in the environment, it is important to understand their environmental fate and the mechanisms by which they might be degraded. To evaluate this potential, the following model compounds were selected: difluoromethane sulfonate (DFMS), trifluoromethane

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

1998-01-01

404

Characterization of and Radiation Damage to Urea, Valine, and Sulfur Compounds: Report on Overall Activities.  

National Technical Information Service (NTIS)

The identity and structure of the radical trapped in x-irradiated hydroxyurea have been established. A survey of ionizing irradiation damage to urea compounds as determined by ESR has been made. Five different types of radicals were found. The characteris...

1966-01-01

405

[Pharmaceutical importance of Allium sativum L. 1. Organic sulfur compounds and their transformation based on present knowledge].  

PubMed

The paper sums up new experimental knowledge concerning the individual groups of organic sulfurous substances of the garlic: sulfoxides, thiosulfinate, ajoens, vinyldithiines, alkyl and alkene sulfides and glutamylpeptides of sulfurous amino acids, their transformation reactions (based on the temperature, pH, extraction medium, and time) and the final products of transformations (Scheme 1, 2). It deals with the activity of the enzyme alliinase necessary for the transformation of sulfoxides present in the whole garlic, its isolation and stability as well as the stability of the dominant thiosulfinate allicin in various media and simulated body fluids. It refers to the studies of the metabolism and transformations of the most important sulfurous components performed in vitro on the hepatocytes and on the isolated rat liver, and those carried out in vivo on the rats and including the examination of the composition of the exhaled air. It follows from published papers that all different degradation products of thiosulfinates, mainly the prevailing allicin, are carriers of various biological activities. The paper also lists the types of commercial preparations prepared from the garlic, their differences, and considerable variability of their contents of active principles. PMID:11242829

Sovová, M; Sova, P

2001-01-01

406

Comparative uptake of sulfur in sulfur dioxide and acid rain by corn (Zea mays L. )  

SciTech Connect

This study has compared and evaluated the absorption and accumulation of sulfur from the two major forms of sulfur pollution (sulfur dioxide and sulfur containing acid rain), by seedlings of corn (Zea mays L.). Plants were exposed to matched treatments containing equivalent ..mu..moles S/treatment in sulfur dioxide or simulated acid rain containing sulfuric acid. Pollution levels were chosen to represent low, medium and high ambient pollutant concentrations (0.13, 1.3 and 130.0 ..mu..moles S/treatment). The uptake and distribution of sulfur by plants was followed by using radioactively labelled sulfur (35-S) in both pollutants. Plants were exposed to the pollutants via a single injection of sulfur dioxide or by rainfall simulators with acid rain treatments. From the sulfur dioxide concentrations evaluated (0.67; 1.00; 2.60; 6.70; and 16 ppm), maximum absorption occurred at the highest concentration while sulfur was more efficiently absorbed at lower concentrations. Absorption of sulfur by plants exposed to acid rain (pH 5.4; 4.4; 3.4; and 2.6) was higher with high sulfur/low pH treatments. pH per se, was not responsible for increased sulfur absorption at low pH treatments. Of the total sulfur associated with the plant following exposure to sulfur dioxide and acid rain, 55% and 97%, respectively was not absorbed, and could be released after one minute of a foliar wash. At each equivalent concentration of sulfur, corn seedlings absorbed significantly greater amounts of sulfur from sulfur dioxide than from acid rain.

Simon, J.E.

1984-01-01

407

Sulfur and sulfides in chondrules  

NASA Astrophysics Data System (ADS)

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

Marrocchi, Yves; Libourel, Guy

2013-10-01

408

Optimization of ultrasound assisted-emulsification-dispersive liquid–liquid microextraction by experimental design methodologies for the determination of sulfur compounds in wines by gas chromatography–mass spectrometry  

Microsoft Academic Search

A new method was developed for analyzing sulfur compounds in the aroma of white wines using ultrasound assisted-emulsification-dispersive liquid–liquid microextraction coupled with gas chromatography–mass spectrometry detection. In the present work, the analytical method for simultaneous determination of seven sulfur compounds (methylmercaptoacetate, methyl(methylthio)acetate, 2-methylthioethanol, 3-methylthiopropanol, 3-methylthiohexanol, 4-methylthio-4-methyl-2-pentanone and hexanethiol) is reported. Parameters that affect the efficiency of the methodology such as

Viviana P. Jofré; Mariela V. Assof; Martín L. Fanzone; Héctor C. Goicoechea; Luis D. Martínez; María F. Silva

409

Elimination of sulfur by plasma techniques  

SciTech Connect

Results from this investigation indicated the possibility of eliminating sulfur from organic compounds by means of nonequilibrium plasmas. The desulfurization is most effective for sulfoxides and sulfones, however mercaptans, thioethers, and disulfides show similar yields and degrees of desulfurization when the reactions are carried out in the presence of oxygen. The plasma desulfurization, in most cases, leads to a number of low- and medium molecular weight products indicating that often plasma desulfurization is paralleled by a considerable amount of cracking.

Suhr, H.

1980-03-01

410

Free Radical and Electrochemically Induced Oxidation of Organic Sulfur, Selenium and Phosphorus-Compounds  

Microsoft Academic Search

A series of MeS(CH2), SMe, MeS(CH2)n SeMe, MeSe(CH2)n SeMe (with n = 1?5), and RS(CH2), PEt2 (n = 2?4) have been investigated with respect to their radiation chemical one-electron and electrochemical two-electron oxidations. The results essentially confirm an interaction of the two respective heteroatoms in these compounds already in the unoxidized state. Oxidation is thus achieved by removal of antibonding

Thomas Tobien; Hartmut Hungerbühler; Klaus-Dieter Asmus

1994-01-01

411

Sulfur diagenesis in everglades peat and origin of pyrite in coal.  

PubMed

The pattern of sulfur transformation in peat across the Everglades basin indicates that pyrite formation in organic-rich swamps depends on the use of organic oxysulfur compounds in dissimilatory respiration by sulfur-reducing bacteria. This paragenesis explains the primary distribution of sulfur compounds in low-sulfur coals and possibly in most coals and many organic-rich soils and sediments. It also accounts for the occurrence of framboidal pyrite bound in fossil tissue in coal and sediments. PMID:17815176

Altschuler, Z S; Schnepfe, M M; Silber, C C; Simon, F O

1983-07-15

412

Sulfur Diagenesis in Everglades Peat and Origin of Pyrite in Coal  

Microsoft Academic Search

The pattern of sulfur transformation in peat across the Everglades basin indicates that pyrite formation in organic-rich swamps depends on the use of organic oxysulfur compounds in dissimilatory respiration by sulfur-reducing bacteria. This paragenesis explains the primary distribution of sulfur compounds in low-sulfur coals and possibly in most coals and many organic-rich soils and sediments. It also accounts for the

Z. S. Altschuler; M. M. Schnepfe; C. C. Silber; F. O. Simon

1983-01-01

413

Sulfur diagenesis in Everglades peat and origin of pyrite in coal  

Microsoft Academic Search

The pattern of sulfur transformation in peat across the Everglades basin indicates that pyrite formation in organic-rich swamps depends on the use of organic oxysulfur compounds in dissimilatory respiration by sulfur-reducing bacteria. This paragenesis explains the primary distribution of sulfur compounds in low-sulfur coals and possibly in most coals and many organic-rich soils and sediments. It also accounts for the

Z. S. Altschuler; M. M. Schnepfe; C. C. Silber; F. O. Simon

1983-01-01

414

Sulfur diagenesis in Everglades peat and origin of pyrite in coal  

SciTech Connect

The pattern of sulfur transformation in peat across the Everglades basin indicates that pyrite formation in organic-rich swamps depends on the use of organic oxysulfur compounds in dissimilatory respiration by sulfur-reducing bacteria. This paragenesis explains the primary distribution of sulfur compounds in low-sulfur coals and possibly in most coals and many organic-rich soils and sediments. It also accounts for the occurrence of framboidal pyrite bound in fossil tissue in coal and sediments.

Altschuler, Z.S.; Schnepfe, M.M.; Silber, C.C.; Simon, F.O.

1983-07-15

415

Sodium sulfur battery: An overview  

NASA Astrophysics Data System (ADS)

High theoretical specific energy values are expected from batteries with low equivalent weight reactants and large electronegativity differences. Alkali metals, acting as the negative electrode, and the chalcogenides as the positive electrode, potentially could produce a battery with high specific energy density. Weber and Kummer demonstrated such a battery using sodium and sulfur as the two electrode materials. The key to the development of this battery was the discovery that solid electrolytes such as beta-alumina conducts sodium ions efficiently. Since then other glassy materials have been shown to be adequate conductors of sodium ions as well. Based on these two types of electrolytes, three approaches to the design of the sodium/sulfur battery have evolved. This paper provides a brief overview of these design approaches.

Sen, R. K.; Landgrebe, A. L.

1987-01-01

416

Missing SO2 oxidant in the coastal atmosphere? - Evidence from high resolution measurements of OH and atmospheric sulfur compounds  

NASA Astrophysics Data System (ADS)

Diurnal and seasonal variations of gaseous sulfuric acid (H2SO4) and methane sulfonic acid (MSA) were measured in N.E. Atlantic air at the Mace Head atmospheric research station during the years 2010 and 2011. The measurements utilized selected ion/chemical ionization mass spectrometry (SI/CIMS) with a detection limit for both compounds of 4.3 × 10 4 cm-3 at 5 min signal integration. The H2SO4 and MSA gas-phase concentrations were analysed in conjunction with the condensational sink for both compounds derived from 3 nm-10 ?m (diameter) aerosol size distributions. Accommodation coefficients of 1.0 for H2SO4 and 0.12 for MSA were assumed leading to estimated atmospheric lifetimes of the order of 7 min and 25 min, respectively. With the SI/CIMS instrument in OH measurement mode alternating between OH signal and background (non-OH) signal evidence was obtained for the presence of one or more unknown oxidants of SO2 in addition to OH. Depending on the nature of the oxidant(s) their ambient concentration may be enhanced in the CIMS inlet system by additional production. The apparent unknown SO2 oxidant was additionally confirmed by direct measurements of SO2 in conjunction with calculated H2SO4 concentrations. The calculated concentrations were consistently lower than the measured concentrations by a factor 4.8 ± 3.4 when considering the oxidation of SO2 by OH as the only source of H2SO4. Both the OH and the background signal were also observed to increase significantly during daytime aerosol nucleation events, independent of the ozone photolysis frequency, J(O1D), and were followed by peaks in both H2SO4 and MSA concentrations. This suggests a strong relation between the unknown oxidant(s), OH chemistry, and the atmospheric photo-oxidation of biogenic iodine compounds. As to the identity of the oxidant(s), we have been able to exclude ClO, BrO, IO, and OIO as possible candidates based on ab initio calculations. Stabilized Criegee intermediates (sCI) produced from ozonolysis of alkenes potentially contribute to the oxidation efficiency of the coastal and marine atmosphere. However, analysis of the CIMS background signal in context with recently published kinetic data currently suggests that larger Criegee intermediates produced from ozonolysis play no significant role for SO2 oxidation in the marine atmosphere. The possibility of H2SO4 formation without SO2 as precursor or from SO2 oxidation by small sCI produced photolytically should be explored.

Berresheim, H.; Adam, M.; Monahan, C.; O'Dowd, C.; Plane, J. M. C.; Bohn, B.; Rohrer, F.

2014-01-01

417

[Sulfur isotopic ratios indicating sulfur cycling in slope soils of karst areas].  

PubMed

Sequential extraction methods for soil sulfur were used to determine delta34 S ratios and sulfur contents of total sulfur, organic sulfur, SO4(21) and FeS2 in slope soils of karst areas. In general, FeS2 has the lowest delta34 S ratios, ranging from -6.86% per hundred to -4.229% per hundred, followed in ascending order by SO4(2-) (-2.64% per hundred - -1.34% per hundred), total sulfur (-3.25% per hundred - -1.03% per hundred) and organic sulfur (-1.63% per hundred -0.50% per hundred) in surface soils of profiles, and delta34 S ratios in different sulfur forms all show increasing trend with profiles deepening. Covariations of delta34 S ratios of SO4(2-) and FeS2 with increasing depth are related to SO4(2-) dissimilatory reduction, while the increase in parallel of delta34 S ratios of total sulfur and organic sulfur could be resulted from organic sulfur cycling. delta34 S ratios have been extensively used to indicate sulfur sources, moreover, SO4(2-) dissimilatory reduction and organic sulfur mineralization result in significant sulfur isotopic fractionation, and sulfides oxidation and SO4(2-) assimilation have no isotopic fractionation occurred, the vertical variations of delta34 S ratios in different sulfur forms can therefore be good records for depth-dependant sulfur cycling processes. Furthermore, by comparing depth distributions of sulfur contents and delta34 S ratios in different sulfur forms, it is easily to discuss the migration of SO4(-1) and organic sulfur fractions in soil profiles. PMID:20391712

Zhang, Wei; Liu, Cong-qiang; Li, Xiao-dong; Liu, Tao-ze; Zhang, Li-li

2010-02-01

418

Absorption measurements of sulfur vapor  

Microsoft Academic Search

Summary form only given, as follows. High intensity pure sulfur discharge lamps have recently attracted attention due their excellent lamp efficacy. The observed emission spectrum originates from pressure broadened vibronic transitions of the S2 molecule modified by self-absorption in the ultraviolet and blue spectral regions. No atomic lines from S(I) are found in the emission spectra. The absorption coefficients for

G. W. Doll; W. P. Lapatovich

1996-01-01

419

Determination of volatile organic sulfur compounds in the air at sewage management areas by thermal desorption and gas chromatography–mass spectrometry  

Microsoft Academic Search

The concentrations of seven volatile organic sulfur compounds (VOSCs) in air samples were determined by active collection on multisorbent tubes followed by two-stage thermal desorption and gas chromatography–mass spectrometry. The compounds studied were ethyl mercaptan (CH3CH2SH), dimethyl sulfide ((CH3)2S), carbon disulfide (CS2), propyl mercaptan (C3H8S), butyl mercaptan (C4H10S), dimethyl disulfide ((CH3)2S2) and 1-pentanethiol (C5H12S). Active collection on SilcoSteel multisorbent tubes

Maria Rosa Ras; Francesc Borrull; Rosa Maria Marcé

2008-01-01

420

Comparative Aspects of Sulfur Mineralization in Sediments of a Eutrophic Lake Basin †  

PubMed Central

The net mineralization of organic sulfur compounds in surface sediments of Wintergreen Lake was estimated from a mass-balance budget of sulfur inputs and sediment sulfur concentrations. The net mineralization of organic sulfur inputs is <50% complete, which is consistent with the dominance of organic sulfur (>80% of total sulfur) in sediment. Although sediment sulfur is predominantly organic, sulfate reduction is the most significant process in terms of the quantities of sulfur transformed in surface sediments. Rates of sulfate reduction in these sediments average 7 mmol/m2 per day. On an annual basis, this rate is 19-fold greater than net rates of organic sulfur mineralization and 65-fold greater than sulfate ester hydrolysis.

King, Gary M.; Klug, M. J.

1982-01-01

421

Sulfur trioxide tested for retorting oil shale  

SciTech Connect

Conventional methods for shale oil production rely on combustion of pyrolysis by-products to supply the heat for retorting. Sulfur trioxide is a potential alternative to combustion air for generating the process heat. By-product sulfur from the shale retorting and oil upgrading operations is easily converted to sulfur trioxide. The potential heat generation with sulfur trioxide is greater than with conventional combustion reactions because the sulfur trioxide reacts exothermically not only with the organic carbon but also with carbonate minerals in the shale. This additional heat generation may facilitate retorting of leaner grade shales which produce less by-product gas and residual carbon for use as process fuel. The sulfur trioxide is also more easily concentrated than atmospheric oxygen, so there is less dilution of the retort gas with inert combustion products. Sulfur trioxide is a strong oxidizer and can react exothermically with both the inorganic and organic constituents of oil shale. To avoid oil degradation, the preferred reactions are those with mineral carbonates and water. These reactions can produce sufficient heat to retort oil shale. However, there are a number of deleterious reactions which can degrade the product oil at retorting temperatures. The deleterious reactions are basically direct oxidation of organic carbon. Other deleterious reactions are sulfonation of aromatic hydrocarbons and olefins. Alkanes do not react readily with sulfur trioxide or concentrated sulfuric acid, but the aromatic hydrocarbons and olefins are easily reacted. These sulfonation reactions badly degrade the production oil by increasing the sulfur concentration.

Not Available

1986-06-01

422

The 1950 sulfur flow of Mauna Loa: Considerations for Io  

NASA Technical Reports Server (NTRS)

Some of the geological relationships observed in the Mauna Loa sulfur flow may apply in considering volcanic processes on Io. Given the presence of sulfur/sulfur compounds in the eruption plumes and on the surface of Io, it is likely that extensive secondary deposits of sulfur exist, some of which may be of fumarolic origin and analogous to the Mauna Loa deposit. Given the likelihood of silicate volcanism of Io based on the inferred material properties of some flows, and the attendant high temperatures for silicate volcanism, it is likely that the secondary surface deposits of sulfur would have been mobilized without being heated to the high viscosity stage. Mobilized sulfur flows on Io may flow long distances as a result of: (1) low viscosities in the melting range; (2) sustained effusion resulting from continued heating source area; (3) continued remobilization within the flow as a consequence of surges from the source; and (4) extension via lava tubes, or similar conduits through which there is little heat loss. Sulfur flows may form a relatively thin veneer over silicate flows and other surface units, given their fluidity and low mobilization temperature. Active splashing and splattering may spread sulfur over a wider area contributing the bright blooms observed in association with some Ionian flows.

Greeley, R.; Theilig, E.; Christensen, P.

1984-01-01

423

Analytical method for the evaluation of sulfur functionalities in American coals. Final report  

SciTech Connect

This investigation consisted of the following 6 tasks: (1) improve the instrumentation for the sulfur functional groups analysis and make it more reliable. (2) create a set of reference standards of sulfur-containing compounds. (3) examine the sulfur groups distribution in untreated and desulfurized coals. (4) examine the sulfur functionalities in raw and processed coals, i.e., liquefied coals. (5) determine the distribution of sulfur functionalities in modified coals. (6) prepare computer programs for calculations related to the distribution of sulfur functional groups in coal. Each task is discussed and results are presented. Appendix A contains the computer program used to interpret the data. 31 references, 56 figures, 17 tables.

Attar, A.

1983-05-01

424

Sulfur removal from high-sulfur Illinois coal by low-temperature perchloroethylene (PCE) extraction. Final technical report, 1 September, 1992--31 August, 1993  

SciTech Connect

The Midwest Ore Processing Co. (MWOPC) has reported a precombustion coal desulfurization process using perchloroethylene (PCE) at 120 C to remove up to 70% of the organic sulfur. The purposes of this research were to independently confirm and possibly to improve the organic sulfur removal from Illinois coals with the PCE desulfurization and to verify the ASTM forms-of-sulfur determination for evaluation of the process. An additional goal was to develop a dechlorination procedure to remove excess PCE from the PCE-treated coal. A laboratory scale operation of the MWOPC PCE desulfurization process was demonstrated, and a dechlorination procedure to remove excess PCE from the PCE-treated coal was developed. The authors have determined that PCE desulfurization removed mainly elemental sulfur from coal. The higher the level of coal oxidization, the larger the amount of elemental sulfur that is removed by PCE extraction. The increased elemental sulfur during short-term preoxidation is found to be pH dependent and is attributed to coal pyrite oxidation under acidic (pH < 2) conditions. The non-ASTM sulfur analyses confirmed the hypothesis that the elemental sulfur produced by oxidation of pyrite complicates the interpretation of analytical data for PCE process evaluations when only the ASTM forms-of-sulfur is used. When the ASTM method is used alone, the elemental sulfur removed during PCE desulfurization is counted as organic sulfur. A study using model compounds suggests that mild preoxidation treatment of coal described by MWOPC for removal of organic sulfur does not produce enough oxidized organic sulfur to account for the amounts of sulfur removal reported. Furthermore, when oxidation of coal-like organosulfur compounds does occur, the products are inconsistent with production of elemental sulfur, the product reported by MWOPC. Overall, it is demonstrated that the PCE process is not suitable for organic sulfur removal.

Chou, M.I.M.; Lytle, J.M.; Ruch, R.R.; Kruse, C.W.; Chaven, C.; Hackley, K.C.; Hughes, R.E.; Harvey, R.D.; Frost, J.K. [Illinois State Geological Survey, Champaign, IL (United States); Buchanan, D.H. [Eastern Illinois Univ., Charleston, IL (United States); Stucki, J.W. [Univ. of Illinois, Urbana, IL (United States); Huffman, G.P.; Huggins, F.E. [Univ. of Kentucky, Lexington, KY (United States)

1993-12-31

425

Biotic and abiotic carbon to sulfur bond cleavage. Final report  

SciTech Connect

The microbial desulfurization of organosulfur compounds occurs by unprecedented and largely unexplored biochemical processes. A study of such biotic desulfurizations can be expected to give rise to new and useful chemistry and enzymology. The potential value of understanding and harnessing these processes is seen in relation to the need for methods for the removal of organically bound sulfur from coal and the degradation of organic sulfur-containing pollutants. This research effort has been directed towards an examination of desulfurization ability in well characterized microorganisms, the isolation of bacteria with desulfurization ability from natural sources, the characterization and mechanistic evaluation of the observed biocatalytic processes, the development of biomimetic synthetic organic chemistry based on biotic desulfurization mechanisms and the design and preparation of improved coal model compounds for use in microbial selection processes. A systematic approach to studying biodesulfurizations was undertaken in which organosulfur compounds have been broken down into classes based on the oxidation state of the sulfur atom and the structure of the rest of the organic material. Microbes have been evaluated in terms of ability to degrade organosulfur compounds with sulfur in its sulfonic acid oxidation state. These compounds are likely intermediates in coal desulfurization and are present in the environment as persistent pollutants in the form of detergents. It is known that oxygen bonded to sulfur lowers the carbon-sulfur bond energy, providing a thermodynamic basis for starting with this class of compounds.

Frost, J.W.

1994-05-01

426

An Exported Rhodanese-Like Protein Is Induced during Growth of Acidithiobacillus ferrooxidans in Metal Sulfides and Different Sulfur Compounds  

PubMed Central

By proteomic analysis we found a 21-kDa protein (P21) from Acidithiobacillus ferrooxidans ATCC 19859 whose synthesis was greatly increased by growth of the bacteria in pyrite, thiosulfate, elemental sulfur, CuS, and ZnS and was almost completely repressed by growth in ferrous iron. After we determined the N-terminal amino acid sequence of P21, we used the available preliminary genomic sequence of A. ferrooxidans ATCC 23270 to isolate the DNA region containing the p21 gene. The nucleotide sequence of this DNA fragment contained a putative open reading frame (ORF) coding for a 23-kDa protein. This difference in size was due to the presence of a putative signal peptide in the ORF coding for P21. When p21 was cloned and overexpressed in Escherichia coli, the signal peptide was removed, resulting in a mature protein with a molecular mass of 21 kDa and a calculated isoelectric point of 9.18. P21 exhibited 27% identity and 42% similarity to the Deinococcus radiodurans thiosulfate-sulfur transferase (rhodanese; EC 2.8.1.1) and similar values in relation to other rhodaneses, conserving structural domains and an active site with a cysteine, both characteristic of this family of proteins. However, the purified recombinant P21 protein did not show rhodanese activity. Unlike cytoplasmic rhodaneses, P21 was located in the periphery of A. ferrooxidans cells, as determined by immunocytochemical analysis, and was regulated depending on the oxidizable substrate. The genomic context around gene p21 contained other ORFs corresponding to proteins such as thioredoxins and sulfate-thiosulfate binding proteins, clearly suggesting the involvement of P21 in inorganic sulfur metabolism in A. ferrooxidans.

Ramirez, Pablo; Toledo, Hector; Guiliani, Nicolas; Jerez, Carlos A.

2002-01-01

427

Quantitative speciation of sulfur in bacterial sulfur globules: X-ray absorption spectroscopy reveals at least three different species of sulfur  

Microsoft Academic Search

X-ray absorption near edge structure (XANES) spectroscopy at the sulfur K- edge was applied to probe the speciation of sulfur of metabolically different sulfur-accumulating bacteria in situ. Fitting the spectra using a least-square fitting routine XANES reveals at least three different forms of sulfur in bacterial sulfur globules. Cyclooctasulfur dominates in the sulfur globules of Beggiatoa alba and the very

Alexander Prange; Reinhold Chauvistre; Hartwig Modrow; Josef Hormes; Hans G. Tru; Christiane Dahl

428

Biodesulfurization of dibenzothiophene and other organic sulfur compounds by a newly isolated Microbacterium strain ZD-M2.  

PubMed

A new bacterial strain capable of selectively desulfurizing dibenzothiphene (DBT) was isolated from sludge. This organism, designated ZD-M2, clustered most closely with members of the genus Microbacterium, as determined by 16S rRNA gene sequence analysis. Metabolites produced by DBT desulfurization were identified by GC-MS, and two sulfur-free products, 2-methoxybiphenyl (2-MBP) and biphenyl, were detected in addition to 2-hydroxybiphenyl (2-HBP). This strain can also totally degrade 4,6-dimethyl-DBT, thiophene, benzothiophene and 70% diphenylsulfide. PMID:15927746

Li, Wei; Zhang, Ying; Wang, Miao Dong; Shi, Yao

2005-06-01

429

Radiolysis of sulfuric acid, sulfuric acid monohydrate, and sulfuric acid tetrahydrate and its relevance to Europa  

NASA Astrophysics Data System (ADS)

We report laboratory studies on the 0.8 MeV proton irradiation of ices composed of sulfuric acid (H 2SO 4), sulfuric acid monohydrate (H 2SO 4·H 2O), and sulfuric acid tetrahydrate (H 2SO 4·4H 2O) between 10 and 180 K. Using infrared spectroscopy, we identify the main radiation products as H 2O, SO 2, (S 2O 3) x, H 3O +, HSO4-, and SO42-. At high radiation doses, we find that H 2SO 4 molecules are destroyed completely and that H 2SO 4·H 2O is formed on subsequent warming. This hydrate is significantly more stable to radiolytic destruction than pure H 2SO 4, falling to an equilibrium relative abundance of 50% of its original value on prolonged irradiation. Unlike either pure H 2SO 4 or H 2SO 4·H 2O, the loss of H 2SO 4·4H 2O 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 SO 2 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.

Loeffler, M. J.; Hudson, R. L.; Moore, M. H.; Carlson, R. W.

2011-09-01

430

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

NASA Technical Reports Server (NTRS)

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.

Loeffler, M. J.; Hudson, R. L.; Moore, M. H.; Carlson, R. W.

2011-01-01

431

Changes in pulmonary lavage fluid of guinea pigs exposed to ultrafine zinc oxide with adsorbed sulfuric acid  

Microsoft Academic Search

Ultrafine metal oxide particles (diameters less than 0.1 ?m) and sulfur dioxide are important products of coal combustion. Interaction of these products in the effluent stream results in formation of ultrafine particles with adsorbed sulfur compounds, including sulfuric acid. The toxicity of ultrafine zinc oxide particles with adsorbed sulfuric acid was evaluated by comparing pulmonary lavage fluid from guinea pigs

Michael W. Conner; William H. Flood; Adrianne E. Rogers; Mary O. Amdur

1989-01-01

432

Antimicrobial Activity of the Iron-Sulfur Nitroso Compound Roussin's Black Salt [Fe4S3(NO)7] on the Hyperthermophilic Archaeon Pyrococcus furiosus?  

PubMed Central

The iron-sulfur nitroso compound [Fe4S3(NO)7]? is a broad-spectrum antimicrobial agent that has been used for more than 100 years to combat pathogenic anaerobes. Known as Roussin's black salt (RBS), it contains seven moles of nitric oxide, the release of which was always assumed to mediate its cytotoxicity. Using the hyperthermophilic archaeon Pyrococcus furiosus, it is demonstrated through growth studies, membrane analyses, and scanning electron microscopy that nitric oxide does not play a role in RBS toxicity; rather, the mechanism involves membrane disruption leading to cell lysis. Moreover, insoluble elemental sulfur (S0), which is reduced by P. furiosus to hydrogen sulfide, prevents cell lysis by RBS. It is proposed that S0 also directly interacts with the membranes of P. furiosus during its transfer into the cell, ultimately for reduction by a cytosolic NADPH sulfur reductase. RBS is proposed to be a new class of inorganic antimicrobial agent that also has potential use as an inert cell-lysing agent.

Hamilton-Brehm, Scott D.; Schut, Gerrit J.; Adams, Michael W. W.

2009-01-01

433

Ceramic-metal seals for advanced battery systems. [sodium sulfur and lithium sulfur batteries  

NASA Technical Reports Server (NTRS)

The search for materials which are electrochemically compatible with the lithium sulfur and sodium sulfur systems is discussed. The use liquid or braze alloys, titanium hydrite coatings, and tungsten yttria for bonding beryllium with ceramic is examined.

Reed, L.

1978-01-01

434

Ectothiorhodospira mobilis Pelsh, a Photosynthetic Sulfur Bacterium Depositing Sulfur Outside the Cells1  

PubMed Central

From salt flats on the Galapagos Islands, two strains of a red photosynthetic bacterium were isolated and identified as Ectothiorhodospira mobilis, an organism first described by Pelsh in 1937. The cells are curved in a short spiral, 0.7 to 1.0 ? wide and 2.0 to 4.8 ? long. They are motile by a polar tuft of flagella. Cells contain several large stacks of lamellar membranes, carrying the pigments bacteriochlorophyll a and carotenoids of the spirillo xanthin series. Cell division occurs by binary fission, not budding. The organism is strictly anaerobic and obligately photosynthetic. Its ability to grow well with sulfide, sulfur, thiosulfate, or sulfite as photosynthetic H donors puts it taxonomically in the Thiorhodaceae. During growth with sulfide, elementary sulfur is deposited outside the cells in the medium and disappears during further growth. A limited number of organic carbon compounds can be utilized as hydrogen donors in place of inorganic sulfur compounds. Under these conditions, sulfate can serve as the sulfur source. The enzymes catalase and hydrogenase are present. The newly isolated strains require vitamin B12. They also require a salinity of 2 to 3% NaCl, but they are not extreme halophiles. The organism is not identical with any of the species listed in Bergey's Manual. Images

Truper, Hans G.

1968-01-01

435

Ectothiorhodospira mobilis Pelsh, a photosynthetic sulfur bacterium depositing sulfur outside the cells.  

PubMed

From salt flats on the Galapagos Islands, two strains of a red photosynthetic bacterium were isolated and identified as Ectothiorhodospira mobilis, an organism first described by Pelsh in 1937. The cells are curved in a short spiral, 0.7 to 1.0 mu wide and 2.0 to 4.8 mu long. They are motile by a polar tuft of flagella. Cells contain several large stacks of lamellar membranes, carrying the pigments bacteriochlorophyll a and carotenoids of the spirillo xanthin series. Cell division occurs by binary fission, not budding. The organism is strictly anaerobic and obligately photosynthetic. Its ability to grow well with sulfide, sulfur, thiosulfate, or sulfite as photosynthetic H donors puts it taxonomically in the Thiorhodaceae.