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1

Airborne measurements of sulfur dioxide, dimethyl sulfide, carbon disulfide, and carbonyl sulfide by isotope dilution gas chromatography/mass spectrometry  

NASA Technical Reports Server (NTRS)

A gas chromatograph/mass spectrometer is described for determining atmospheric sulfur dioxide, carbon disulfide, dimethyl sulfide, and carbonyl sulfide from aircraft and ship platforms. Isotopically labelled variants of each analyte were used as internal standards to achieve high precision. The lower limit of detection for each species for an integration time of 3 min was 1 pptv for sulfur dioxide and dimethyl sulfide and 0.2 pptv for carbon disulfide and carbonyl sulfide. All four species were simultaneously determined with a sample frequency of one sample per 6 min or greater. When only one or two species were determined, a frequency of one sample per 4 min was achieved. Because a calibration is included in each sample, no separate calibration sequence was needed. Instrument warmup was only a few minutes. The instrument was very robust in field deployments, requiring little maintenance.

Bandy, Alan R.; Thornton, Donald C.; Driedger, Arthur R., III

1993-01-01

2

Operational overview of the NASA GTE/CITE 3 airborne instrument intercomparisons for sulfur dioxide, hydrogen sulfide, carbonyl sulfide, dimethyl sulfide, and carbon disulfide  

NASA Technical Reports Server (NTRS)

This paper reports the overall experimental design and gives a brief overview of results from the third airborne Chemical Instrumentation Test and Evaluation (CITE 3) mission conducted as part of the National Aeronautics and Space Administration's Global Tropospheric Experiment. The primary objective of CITE 3 was to evaluate the capability of instrumentation for airborne measurements of ambient concentrations of SO2, H2S, CS, dimethyl sulfide, and carbonyl sulfide. Ancillary measurements augmented the intercomparison data in order to address the secondary objective of CITE 3 which was to address specific issues related to the budget and photochemistry of tropospheric sulfur species. The CITE 3 mission was conducted on NASA's Wallops Flight Center Electra aircraft and included a ground-based intercomparison of sulfur standards and intercomparison/sulfur science flights conducted from the NASA Wallops Flight Facility, Wallops Island, Virginia, followed by flights from Natal, Brazil. Including the transit flights, CITE 3 included 16 flights encompassing approximately 96 flight hours.

Hoell, James M., Jr.; Davis, Douglas D.; Gregory, Gerald L.; Mcneal, Robert J.; Bendura, Richard J.; Drewry, Joseph W.; Barrick, John D.; Kirchhoff, Volker W. J. H.; Motta, Adauto G.; Navarro, Roger L.

1993-01-01

3

Seasonal and short-term variability in dimethyl sulfide, sulfur dioxide and biogenic sulfur and sea salt aerosol particles in the arctic marine boundary layer during summer and autumn  

NASA Astrophysics Data System (ADS)

The International Arctic Ocean Expedition (IAOE), lasting from August to mid-October 1991, provided a unique opportunity to characterize and quantify relationships within the natural sulfur cycle in the marine boundary layer under conditions of limited anthropogenic influence. Concentrations of dimethyl sulfide, sulfur dioxide, and submicrometer aerosol concentrations of methane sulfonate, non-sea-salt sulfate, ammonium and elemental carbon ranged from 17 to 0.05nmol m-3 (380 1 ppt(v)), 1.7 0.04nmol m-3 (38 0.9 ppt(v)), 1.4 0.002nmol m-3 (31 0.05 ppt(v), 6.9 0.03nmol m-3 (155 0.7 ppt(v)), 3.9 0.03nmol m-3 (90 0.7 ppt(v)) and 0.51 0.009nmol m-3 (11 0.2 ppt(v)), respectively. Observations showed a seasonal variation of concentrations with highest values for all the marine biogenic sulfur gas-aerosol parametres along the ice edge zone in August and lowest values over the pack ice in late September On average concentrations fell with a decline rate of about 20 40% per week. A similar seasonal change was also reflected in particulate ammonium. This therefore indicates links between the different sulfur compounds as well as between the biogenic sulfur and nitrogen cycles. Concentrations over the pack ice region were generally lower than over the open waters at the ice edge with an estimated net loss rate of roughly 35% per day of transport over the pack ice. Contrary to earlier marine sulfur studies performed outside the Arctic region, a constant methane sulfonate to non-sea-salt sulfate molar ratio was found in the submicrometer size fraction for samples with a minimal influence from fog and anthropogenic sources. This ratio had a value of 0.22 in spite of large seasonal changes in temperature and concentrations of methane sulfonate and non-sea-salt sulfate. Thus we conclude that the sum of the proceses controlling the measured particle properties do not exhibit a net temperature dependence. The one to one molar ratio of ammonium to non-sea-salt sulfate indicated a partly neutralised ammoniated sulfate aerosol. This was further verified by single particle analysis. Measurements of non-sea-salt sulfate and ammonium revealed a bimodal size distribution with about 70% of their mass found in the submicrometer size fraction. Methane sulfonate was mainly associated with submicrometer particles, with less than 8% of the mass observed in the largest particles. We have also shown that the interchange of air between the surface mixed layer and clouds, caused by atmospheric wave motions, dominated the short time variations in atmospheric DMS and submicrometer aerosol concentrations. This interchange will have a strong influence on the chemical and physical processes that control the properties of the aerosol, and deserves more attention in future work.

Leck, Caroline; Persson, Cecilia

1996-04-01

4

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...

5

Natural sulfur dioxide emissions from sulfuric soils  

NASA Astrophysics Data System (ADS)

Soils have long been recognised as sulfur dioxide (SO 2) sinks, but we show that they can also be sources of atmospheric SO 2. Using static chambers and micrometeorological techniques, we have measured emissions of SO 2 from coastal lowland soils containing sulfides (mostly pyrite), commonly referred to as acid sulfate soils in Australia. SO 2 evolution seems coupled to evaporation of soil water containing sulfite. The global emissions of S from acid sulfate soils is estimated at about 3 Tg/year, which is of the same order as emissions from terrestrial biogenic sources and biomass burning and is about 3% of known anthropogenic emissions of S.

Macdonald, Bennett C. T.; Denmead, O. Tom; White, Ian; Melville, Michael D.

6

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

Code of Federal Regulations, 2012 CFR

...ambient air quality standard for sulfur oxides (sulfur dioxide). 50.5 Section...ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The...shall be rounded up). (b) Sulfur oxides shall be measured in the ambient...

2012-07-01

7

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

Code of Federal Regulations, 2013 CFR

...ambient air quality standard for sulfur oxides (sulfur dioxide). 50.5 Section...ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The...shall be rounded up). (b) Sulfur oxides shall be measured in the ambient...

2013-07-01

8

Catalytic oxidation of sulfur dioxide  

SciTech Connect

A review of the vanadium-catalyzed sulfur dioxide oxidation at 400/sup 0/C (ignition point) to 620/sup 0/C (thermal deactivation point) and 6-12% initial SO/sub 2/ concentration covers the vanadium catalyst composition and properties; the reaction mechanism; 29 kinetic equations, their range of applicability, and their inadequacy as general rate equations; intraparticle mass and heat transfer studies; experimental methods for determining the global reaction rate; and reactor design, including mathematical modeling and optimization of adiabatic, nonadiabatic, and nonideal adiabatic beds.

Urbanek, A. (Warsaw Tech. Univ.); Trela, M.

1980-01-01

9

Production of sulfur from sulfur dioxide obtained from flue gas  

SciTech Connect

This patent describes a regenerable process for recovery of elemental sulfur from a gas containing sulfur dioxide comprising the steps of: contacting the gas with an aqueous, alkaline reaction medium containing sodium sulfite in concentration sufficient so that a slurry containing solid sodium sulfide is formed to react sulfur dioxide with sodium sulfite to form a solution containing dissolved sodium pyrosulfite and sodium sulfite; separating sulfur dioxide from the solution produced to leave a residual mixture containing water, sodium sulfite and a sodium pyrosulfite, the amount of sulfur dioxide separated being equal to about one-third the amount of sulfur dioxide which reacted with sodium sulfite; adding, in substantial absence of air, sufficient water and sodium bicarbonate to the residual mixture to react with the dissolved sodium pyrsulfide and form a slurry of solid sodium sulfite suspended in the resulting aqueous, alkaline reaction medium and gaseous carbon dioxide; separating the gaseous carbon dioxide; separating the solid sodium sulfite from the aqueous alkaline reaction medium and recycling the separated reaction medium; reducing the separated sodium sulfite to sodium sulfide; adding the sodium sulfide to an aqueous reaction medium containing sodium bicarbonate and, in the substantial absence of air, carbonating the resulting mixture with the gaseous carbon dioxide to form a slurry of solid particles of sodium bicarbonate dispersed in an aqueous reactor medium containing sodium bicarbonate, along with a gas composed primarily of hydrogen sulfide.

Miller, R.

1989-06-06

10

Sulfur Dioxide: Its Role in Climate Change  

NSDL National Science Digital Library

In this problem-based learning activity, learners investigate impact of sulfur dioxide on the environment. Sulfur dioxide comes from both human activities and natural sources. Burning coal and other fossil fuels is the largest source of sulfur dioxide from human activities. Students have a choice of analyzing the impact of volcanoesā emissions of sulfur dioxide on the environment; they can also investigate the idea of injecting sulfates into the atmosphere to counteract global warming. Instructions to access NASA data are provided along with additional resources and activities. This module was developed to be used in the Earth System Science Education Alliance (ESSEA) courses for middle and high school teachers and is also available to teachers to adapt for general classroom use.

11

Sensitivity of mosses to sulfur dioxide  

Microsoft Academic Search

Seven North American moss species responded differentially to fumigations with sulfur dioxide ranging from 0.5 to 4.0 ppm. Leucobryum glaucum and Dicranum scoparium were the most sensitive species; Dicranella heterophylla, Polytrichum ohioense and Pottia truncata, the most resistant. The results of fumigations with 0.1 to 4.0 ppm sulfur dioxide for 8 hours on cultured gametophytes of Polytrichum ohioense indicate that

T. H. Nash; E. H. Nash

1974-01-01

12

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

13

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

Code of Federal Regulations, 2010 CFR

...National secondary ambient air quality standard for sulfur oxides (sulfur dioxide...PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS § 50.5 National secondary ambient air quality standard for sulfur oxides (sulfur...

2010-07-01

14

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

Code of Federal Regulations, 2011 CFR

...National secondary ambient air quality standard for sulfur oxides (sulfur dioxide...PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS § 50.5 National secondary ambient air quality standard for sulfur oxides (sulfur...

2011-07-01

15

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

Code of Federal Regulations, 2011 CFR

...National primary ambient air quality standards for sulfur oxides (sulfur dioxide...PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS § 50.17 National primary ambient air quality standards for sulfur oxides (sulfur...

2011-07-01

16

Sugar yields from dilute sulfuric acid and sulfur dioxide pretreatments and subsequent enzymatic hydrolysis of switchgrass  

E-print Network

Sugar yields from dilute sulfuric acid and sulfur dioxide pretreatments and subsequent enzymatic Dilute sulfuric acid Sulfur dioxide Biofuels Switchgrass a b s t r a c t Dacotah switchgrass was pretreated with sulfuric acid concentrations of 0.5, 1.0, and 2.0 wt.% at 140, 160, and 180 Ā°C and with 1

California at Riverside, University of

17

Sulfur Dioxide Crossover during the Production of Hydrogen and Sulfuric Acid in a PEM Electrolyzer  

E-print Network

Sulfur Dioxide Crossover during the Production of Hydrogen and Sulfuric Acid in a PEM Electrolyzer in the thermochemical conversion of sulfur dioxide to sulfuric acid for the large-scale production of hydrogen-17 In this thermochemical cycle, sulfuric acid is decomposed at high temperature 850Ā°C to SO2 and wa- ter, and the SO2

Weidner, John W.

18

SULFUR DIOXIDE OXIDATION REACTIONS IN AQUEOUS SOLUTIONS  

EPA Science Inventory

This is the final report on a three year project to study the kinetics and mechanisms of some 105 reactions involving the aqueous oxidation of sulfur dioxide and nitrogen oxides in mixed catalyst-oxidant systems at low pH (0-3). The 105 systems involve six redox reaction types: S...

19

LABORATORY MEASUREMENT OF SULFUR DIOXIDE DEPOSITION VELOCITIES  

EPA Science Inventory

Measurements of sulfur dioxide deposition velocities have been carried out in the laboratory with the use of a cylindrical flow reaction. Analysis of data from these experiments was performed with models that specifically account for diffusive transport in the system. Consequentl...

20

SOLID SORBENT FOR COLLECTING ATMOSPHERIC SULFUR DIOXIDE  

EPA Science Inventory

A solid sorbent for collecting atmospheric SO2 was evaluated as part of an overall effort to develop a replacement method for the West-Gaeke method presently used to measure 24-hour ambient sulfur dioxide concentrations in ambient air. Research showed that a solid sorbent, consis...

21

Radio detection of interstellar sulfur dioxide  

NASA Technical Reports Server (NTRS)

Interstellar sulfur dioxide (SO2) has been detected in emission from the direction of the Orion Nebula molecular cloud and from Sgr B2. SO2 is the heaviest interstellar molecule detected to date, and the only nonlinear triatomic molecule which does not contain hydrogen. The remarkable Orion emission profiles suggest that two components are supporting the SO2 emission: a dense circumstellar-type envelope, which may be in maser emission, and a warm galactic cloud component.

Snyder, L. E.; Hollis, J. M.; Ulich, B. L.; Lovas, F. J.; Johnson, D. R.; Buhl, D.

1975-01-01

22

Sulfur Dioxide Inhibition of Photosynthesis in Isolated Spinach Chloroplasts  

PubMed Central

Photosynthetic oxygen evolution by isolated spinach (Spinacia oleracea L.) chloroplasts approached complete inhibition in the presence of a 5 mm concentration of sulfur dioxide. A similar inhibition was observed in the presence of equimolar concentrations of bisulfite ions, suggesting a parallel mode of action. In contrast, an equimolar concentration of sulfite ions was markedly less inhibitory and sulfate ions caused negligible inhibition of apparent photosynthesis. The mode of action of sulfur dioxide and related sulfur anions in inhibiting photosynthesis was found to be essentially independent of direct hydrogen-ion effects. Supplements of inorganic pyrophosphate lessened the inhibition of oxygen evolution caused by sulfur dioxide and the sulfur anions. Sulfur dioxide and the sulfur anions were almost equally effective in inhibiting cyclic and noncyclic photophosphorylation in chloroplast suspensions. However, the extent of the inhibition of these photosynthetic reactions does not appear sufficient to account for the inhibition of photosynthetic oxygen evolution by sulfur dioxide. PMID:16659319

Silvius, John E.; Ingle, Morris; Baer, Charles H.

1975-01-01

23

40 CFR 60.173 - Standard for sulfur dioxide.  

Code of Federal Regulations, 2013 CFR

...NEW STATIONARY SOURCES Standards of Performance for Primary Zinc Smelters § 60.173 Standard for sulfur dioxide. ...more than 10 percent of the sulfur initially contained in the zinc sulfide ore concentrates will be considered as a roaster...

2013-07-01

24

40 CFR 60.173 - Standard for sulfur dioxide.  

Code of Federal Regulations, 2014 CFR

...NEW STATIONARY SOURCES Standards of Performance for Primary Zinc Smelters § 60.173 Standard for sulfur dioxide. ...more than 10 percent of the sulfur initially contained in the zinc sulfide ore concentrates will be considered as a roaster...

2014-07-01

25

40 CFR 60.173 - Standard for sulfur dioxide.  

Code of Federal Regulations, 2012 CFR

...NEW STATIONARY SOURCES Standards of Performance for Primary Zinc Smelters § 60.173 Standard for sulfur dioxide. ...more than 10 percent of the sulfur initially contained in the zinc sulfide ore concentrates will be considered as a roaster...

2012-07-01

26

Sensitivity of ginseng to ozone and sulfur dioxide  

SciTech Connect

American ginseng (Panax quinquefolius L.), was injured by exposure to 20 pphm ozone and/or 50 pphm (v/v) sulfur dioxide for 6 hr daily for 4 days. Ozone induced upper surface leaflet stippling along the veins and interveinally, and sulfur dioxide induced mild chlorosis to irregular necrotic areas. Ginseng was less sensitive to ozone and as sensitive to sulfur dioxide as 'Cherry Belle' radish (Raphanus sativus L.) and 'Bel W-3' tobacco (Nicotiana tabacum L.).

Proctor, J.T.A.; Ormrod, D.P.

1981-10-01

27

Measuring global sulfur dioxide emissions with satellite sensors  

NASA Astrophysics Data System (ADS)

Atmospheric sulfur dioxide affects the weather by enhancing cloud formation, and long-term shifts in emissions can change the climate by increasing the amount of solar radiation scattered back into space. Sulfur dioxide emissions are the basis for acid rain, and the gas itself can cause respiratory problems. Despite the compound's importance to climate, the difficulties associated with accurately measuring sulfur dioxide mean that rates of emissions are generally not well understood.

Schultz, Colin

2013-11-01

28

Removal of sulfur dioxide from waste gases. [Tertiary amines  

SciTech Connect

In this efficient, low-cost sulfur dioxide-removal process, a waste-gas stream (such as stack gases) contacts free selective tertiary amines having basic strengths greater than about pK 5 (such as trimethylamine, triethylamine, and tri-n-butylamine) to form a coordinate covalent complex of the amine and the sulfur dioxide. The thermal regeneration of this sufficiently stable complex then liberates a stream of sulfur dioxide and a stream of residual gases while providing the regenerated tertiary amine for collection and reuse in a subsequent sulfur dioxide-cleanup step. The coordinate covalent complex reacts with even very small concentrations of sulfur dioxide and reduces it to undetectable levels. Carbon dioxide in the waste-gas stream will not interfere with efficient cleanup because the selected tertiary amine does not react with it.

Klass, D.L.; Conrad, J.R.

1980-06-17

29

40 CFR 60.82 - Standard for sulfur dioxide.  

Code of Federal Regulations, 2014 CFR

...STATIONARY SOURCES Standards of Performance for Sulfuric Acid Plants § 60.82 Standard for sulfur dioxide...dioxide in excess of 2 kg per metric ton of acid produced (4 lb per ton), the production being expressed as 100 percent H2...

2014-07-01

30

40 CFR 60.82 - Standard for sulfur dioxide.  

Code of Federal Regulations, 2010 CFR

...STATIONARY SOURCES Standards of Performance for Sulfuric Acid Plants § 60.82 Standard for sulfur dioxide...dioxide in excess of 2 kg per metric ton of acid produced (4 lb per ton), the production being expressed as 100 percent H2 SO4...

2010-07-01

31

40 CFR 60.82 - Standard for sulfur dioxide.  

Code of Federal Regulations, 2011 CFR

...STATIONARY SOURCES Standards of Performance for Sulfuric Acid Plants § 60.82 Standard for sulfur dioxide...dioxide in excess of 2 kg per metric ton of acid produced (4 lb per ton), the production being expressed as 100 percent H2 SO4...

2011-07-01

32

40 CFR 60.82 - Standard for sulfur dioxide.  

Code of Federal Regulations, 2013 CFR

...STATIONARY SOURCES Standards of Performance for Sulfuric Acid Plants § 60.82 Standard for sulfur dioxide...dioxide in excess of 2 kg per metric ton of acid produced (4 lb per ton), the production being expressed as 100 percent H2 SO4...

2013-07-01

33

40 CFR 60.82 - Standard for sulfur dioxide.  

Code of Federal Regulations, 2012 CFR

...STATIONARY SOURCES Standards of Performance for Sulfuric Acid Plants § 60.82 Standard for sulfur dioxide...dioxide in excess of 2 kg per metric ton of acid produced (4 lb per ton), the production being expressed as 100 percent H2 SO4...

2012-07-01

34

RESPONSE OF MAIZE AND WHEAT TO SULFUR DIOXIDE  

EPA Science Inventory

Four hybrids of maize and seven cultivars of wheat were exposed to relatively low concentrations of sulfur dioxide (0.1 to 0.6 ppm) for up to 100 hours. Maize was found to be tolerant to sulfur dioxide and only minor differences were observed in dry mass, foliar injury, and total...

35

Avoidance responses of estuarine fish to sulfur dioxide. Final report  

SciTech Connect

This study was designed to determine the avoidance responses of juvenile striped bass, Morone saxatilis, and Atlantic menhaden, Brevoortia tyrannus exposed to sulfur dioxide (sulfite) at acclimation temperatures of 15, 20, 25 and 30C. Predictive models were developed and compared for each species at each acclimation temperature. Acclimation temperature was an important factor influencing the avoidance response of each species exposed to sulfur dioxide. Both species avoided approximately the same concentration of sulfite at 25C. Atlantic menhaden avoided lower concentration of sulfur dioxide than striped bass at 30C.

Hall, L.W. Jr; Margrey, S.L.; Graves, W.C.

1983-12-01

36

Control of organo-sulfur emissions using biofiltration: Dimethyl sulfide  

SciTech Connect

Laboratory-scale experiments were conducted to evaluate the removal of dimethyl sulfide (DMS) in both upflow and downflow compost biofilter columns. Gas flow rates and DMS concentrations were varied to study their effects on removal efficiency. The kinetic dependence of DMS removal along the column length was also examined to obtain a quantitative description of pollutant removal. In addition, important operating parameters, such as filter bed pH and water content, as well as gas retention time, were observed throughout the experiments. The maximum pollutant loading rates for the compost filters were found to be 5.2 and 5.5 g-DMS/m{sup 3}/hr for the upflow and downflow biofilter columns, respectively. Removal efficiencies were high (> 95%) for inlet concentrations up to 15 ppm DMS and 30 second empty-bed residence times, or 19 ppm DMS for 45 second residence times. Removal efficiencies remained high (> 95%) for DMS concentrations up to 27 ppm for 60 second residence times. DMS removal rates through the biofilter columns appear to follow fractional-order diffusion-limited macrokinetics. The average macrokinetic rate coefficient for the upflow column was 0.0789 {+-} 0.0178 ppm{sup 1/2}/sec. The average rate coefficient for the downflow column was 0.0935 {+-}0.0200 ppm{sup 1/2}/sec. The biofilter columns were periodically washed to remove sulfuric acid, which is formed as an end-product of the biological degradation of DMS, and to replenish the moisture content of the filter material. It was found that the downflow column benefitted greatly by regular washing with alkaline washwater, while the upflow column operated well with non-alkaline water washing.

Kong, S.; Allen, E.R. [Univ. of Florida, Gainesville, FL (United States). Dept. of Environmental Engineering Sciences

1997-12-31

37

Colorimetric determination of atmospheric sulfur dioxide using 1,3,5-trinitrobenzene  

SciTech Connect

The pararosaniline method has been widely used for colorimetric determination of sulfur dioxide in the atmosphere because of its simplicity, sensitivity, and specificity. However, analyses must be carried out carefully with close attention to temperature, pH, and dye purity. 1,3,5-trinitrobenzene (TNB) forms an addition complex (I) with sulfite in a dimethyl sulfoxide (Me/sub 2/SO)-water mixture to give a highly colored solution. The equilibrium constant for the formation of I is at least one hundred times greater in an aqueous solution containing 70% (v/v) Me/sub 2/SO than in water. Since this reaction gives rapid and stable color development with high absorbance and the blank, attributable to TNB, is not observed, sulfur dioxide in the atmosphere is analyzed with a Me/sub 2/SO-water system containing TNB.

Suzuki, Y.; Imai, S.

1986-12-01

38

40 CFR 180.444 - Sulfur dioxide; tolerances for residues.  

Code of Federal Regulations, 2014 CFR

...false Sulfur dioxide; tolerances for residues. 180.444 Section 180.444...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances §...

2014-07-01

39

40 CFR 180.444 - Sulfur dioxide; tolerances for residues.  

Code of Federal Regulations, 2012 CFR

...false Sulfur dioxide; tolerances for residues. 180.444 Section 180.444...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances §...

2012-07-01

40

CATALYST EVALUATION FOR A SULFUR DIOXIDE-DEPOLARIZED ELECTROLYZER  

SciTech Connect

Thermochemical processes are being developed to provide global-scale quantities of hydrogen. A variant on sulfur-based thermochemical cycles is the Hybrid Sulfur (HyS) Process which uses a sulfur dioxide depolarized electrolyzer (SDE) to produce the hydrogen. Testing examined the activity and stability of platinum and palladium as the electrocatalyst for the SDE in sulfuric acid solutions. Cyclic and linear sweep voltammetry revealed that platinum provided better catalytic activity with much lower potentials and higher currents than palladium. Testing also showed that the catalyst activity is strongly influenced by the concentration of the sulfuric acid electrolyte.

Hobbs, D; Hector Colon-Mercado, H

2007-01-31

41

Sulfur Dioxide Treatment from Flue Gases Using a Biotrickling  

E-print Network

to be a promising alternative for flue gas desulfurization. Introduction Sulfur dioxide (SO2) and sulfur oxides (SOx equipment such as flue gas desulfurization (FGD) systems. FGD is probably the most widely used technique separatebioreactorswhichincreasescapitalcosts(6).Another approach is to pass the flue gas through a biotrickling filter with

42

Sulfur dioxide initiates global climate change in four ways  

Microsoft Academic Search

Global climate change, prior to the 20th century, appears to have been initiated primarily by major changes in volcanic activity. Sulfur dioxide (SO2) is the most voluminous chemically active gas emitted by volcanoes and is readily oxidized to sulfuric acid normally within weeks. But trace amounts of SO2 exert significant influence on climate. All major historic volcanic eruptions have formed

Peter L. Ward

2009-01-01

43

THE EFFECT OF ATRAZINE ON DIMETHYL SULFUR IN MARINE PHYTOPLANKTON  

EPA Science Inventory

It is anticipated that under stress, the cellular DMSP concentration should drop, as sulfur is transferred from the DMSP pool to DMS. Sulfur in the DMS pool will be transferred to the DMSO pool as radicals are scavenged. Enzyme activities such as DMSP lyase, which converts D...

44

Photoreduction of Sulfur Dioxide by Spinach Leaves and Isolated Spinach Chloroplasts  

PubMed Central

Labeled sulfur dioxide was found to be extensively absorbed by spinach (Spinacea oleracea L.) leaves. Labeled sulfides detected in leaf blades following fumigations with sulfur dioxide in light indicated that photoreduction of sulfur dioxide had occurred. Measurable proportions of this labeled sulfur was localized within the chloroplast fraction. Suspensions of isolated chloroplasts supplied with labeled sulfur dioxide contained labeled sulfides following a 30-minute illumination period in water-cooled reaction vessels. With reference to recent studies of the chloroplast sulfur reduction pathway, probable points of entry for sulfur dioxide and the subsequent release of hydrogen sulfide are discussed. PMID:16659572

Silvius, John E.; Baer, Charles H.; Dodrill, Sherman; Patrick, Homer

1976-01-01

45

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

46

Modeling sulfur dioxide capture in a pulverized coal combustor  

Microsoft Academic Search

The formation and capture of sulfur dioxide in a pulverized coal combustor is investigated. A two-dimensional, steady, axisymmetric code, PCGC-2 (Pulverized Coal Gasification and Combustion-two Dimensional), originally developed at Brigham Young University, has been used to simulate combustion of the pulverized coal. This paper represents part of a project to investigate simultaneously enhancing sulfur capture and particulate agglomeration in combustor

R. B. Nair; S. Yavuzkurt

1997-01-01

47

Process for sequestering carbon dioxide and sulfur dioxide  

DOEpatents

A process for sequestering carbon dioxide, which includes reacting a silicate based material with an acid to form a suspension, and combining the suspension with carbon dioxide to create active carbonation of the silicate-based material, and thereafter producing a metal salt, silica and regenerating the acid in the liquid phase of the suspension.

Maroto-Valer, M. Mercedes (State College, PA); Zhang, Yinzhi (State College, PA); Kuchta, Matthew E. (State College, PA); Andresen, John M. (State College, PA); Fauth, Dan J. (Pittsburgh, PA)

2009-10-20

48

75 FR 81555 - Approval and Promulgation of Air Quality Implementation Plans; Minnesota; Sulfur Dioxide SIP...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Implementation Plans; Minnesota; Sulfur Dioxide SIP Revision for Marathon Petroleum St. Paul Park AGENCY: Environmental Protection...sulfur dioxide State Implementation Plan revision request for Marathon Petroleum in St. Paul Park, Minnesota. This submittal...

2010-12-28

49

Smart battery controller for lithium sulfur dioxide batteries  

Microsoft Academic Search

Each year, the U.S. Army purchases millions of lithium sulfur dioxide batteries for use in portable electronics equipment. Because of their superior rate capability and service life over a wide variety of conditions, lithium batteries are the power source of choice for military equipment. There is no convenient method of determining the available energy remaining in partially used lithium batteries;

Terrill Atwater; Arnold Bard; Bruce Testa; William Shader

1992-01-01

50

Regional disparities of Henan economic growth and sulfur dioxide emissions  

Microsoft Academic Search

In order to fully evaluate and understand the environmental pollution situation, and find out the distribution of regional environmental pollution and the gap, we use the Theil coefficient to analyze the regional sulfur dioxide emissions in Henan Province, which will provide a theoretical decision- making for government to further deploy environmental pollution control measures and develop differentiated environmental pollution control

Chuang Li

2011-01-01

51

EVALUATION OF A SULFUR DIOXIDE MASS EMISSION RATE MONITORING SYSTEM  

EPA Science Inventory

An evaluation was conducted to determine the capabilities and limitations of a commercially available monitoring system that provides sulfur dioxide mass emission rate data as a direct output. The monitoring system was operated continuously for extended periods at a coal-fired po...

52

76 FR 56644 - Sulfur Dioxide; Pesticide Tolerances for Emergency Exemptions  

Federal Register 2010, 2011, 2012, 2013, 2014

...critical factors in development of gray mold caused by Botrytis cinerea (B. cinerea...years. California estimated that gray mold could be responsible for a 24% yield loss...sulfur dioxide on figs for control of gray mold caused by B. cinerea in...

2011-09-14

53

SULFUR DIOXIDE SOURCES IN WA, OR, AND ID  

EPA Science Inventory

This map shows industrial plants which emit 100 tons/year or more of sulfur dioxide (SO2) in Idaho, Oregon, and Washington. 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: USGS, Nat...

54

SULFUR DIOXIDE SOURCES IN CLASS I WILDERNESS AREAS, WA  

EPA Science Inventory

This map shows industrial plants which emit sulfur dioxide (SO2) in the state of Washington. Different plot symbols are used for sources which emit less than 100 tons/year, between 100 and 1000 tons/year, and over 1000 tons/year of SO2. The SO2 sources are plotted on a background...

55

LIGNOSULFONATE-MODIFIED CALCIUM HYDROXIDE FOR SULFUR DIOXIDE CONTROL  

EPA Science Inventory

The article discusses the use of lignosulfonate-modified calcium hydroxide Ca(OH)2 for sulfur dioxide (SO2) control. The limestone injection multistage burner (LIMB) process is currently being developed at the U.S. EPA as a low cost retrofittable technology for controlling oxides...

56

Alternative Strategies for Control of Sulfur Dioxide Emissions  

ERIC Educational Resources Information Center

Achievement of air quality goals requires careful consideration of alternative control strategies in view of national concerns with energy and the economy. Three strategies which might be used by coal fired steam electric plants to achieve ambient air quality standards for sulfur dioxide have been compared and the analysis presented. (Author/BT)

MacDonald, Bryce I.

1975-01-01

57

Historical Sulfur Dioxide Emissions 1850-2000: Methods and Results  

SciTech Connect

A global, self-consistent estimate of sulfur dioxide emissions over the last one and a half century were estimated by using a combination of bottom-up and best available inventory methods including all anthropogenic sources. We find that global sulfur dioxide emissions peaked about 1980 and have generally declined since this time. Emissions were extrapolated to a 1{sup o} x 1{sup o} grid for the time period 1850-2000 at annual resolution with two emission height levels and by season. Emissions are somewhat higher in the recent past in this new work as compared with some comprehensive estimates. This difference is largely due to our use of emissions factors that vary with time to account for sulfur removals from fossil fuels and industrial smelting processes.

Smith, Steven J.; Andres, Robert; Conception , Elvira; Lurz, Joshua

2004-01-25

58

Direct extraction of sulfur dioxide from sulfates for isotopic analysis  

SciTech Connect

A convenient method of extraction of sulfur dioxide from natural sulfates (BaSO/sub 4/, SrSO/sub 4/, and CaSO/sub 4/) for sulfur isotopic analysis is described. A sulfate is reacted with NaPO/sub 3/ under vacuum at 850/sup 0/C; SO/sub 3/ thus obtained is then reduced to sulfur dioxide on copper heated to 750/sup 0/C. It has been experimentally shown that the reaction takes place with complete yield and provides very good reproducibility of measurements despite a remarkable variation in /sup 18/O content of analyzed sulfates. The long-term reproducibility of /sup 34/S//sup 32/S ratios is about 0.05 per mil.

Halas, S.; Wolacewicz, W.P.

1981-04-01

59

THE MECHANISM OF SULFUR DIOXIDE INITIATED BRONCHOCONSTRICTION  

EPA Science Inventory

Atmospheric sulfur oxides exist in chemically complex particulates of the respirable size range. Inhalation of these particulates represents a potential health hazard. This report provides the results of a series of experiments into the uptake of sulfate salts by the lung, the in...

60

The removal of sulfur dioxide from flue gases  

PubMed Central

The growth of industrialization makes it imperative to reduce the amounts of sulfur dioxide emitted into the atmosphere. This article describes various processes for cleaning flue gases, and gives details of new methods being investigated. Wet scrubbing with water, though widely practised, has many disadvantages. Scrubbing with zinc oxide, feasible in zinc works, is more satisfactory. Dry methods use a solid absorbent; they have the advantage of a high emission temperature. Other methods are based on the addition to the fuel or the flue gases of substances such as activated metal oxides, which react with the sulfur to form compounds less harmful than sulfur dioxide. Also being investigated are a two-stage combustion system, in which the sulfur dioxide is removed in the first stage, and the injection of activated powdered dolomite into burning fuel; the resulting sulfates being removed by electrostatic precipitation. A wet catalysis process has recently been developed. Most of the cleaning processes are not yet technically mature, but first results show good efficiency and relatively low cost. PMID:14315714

Kettner, Helmut

1965-01-01

61

Airborne sulfur trace species intercomparison campaign: Sulfur dioxide, dimethylsulfide, hydrogen sulfide, carbon disulfide, and carbonyl sulfide  

NASA Technical Reports Server (NTRS)

Results from an airborne intercomparison of techniques to measure tropospheric levels of sulfur trace gases are presented. The intercomparison was part of the NASA Global Tropospheric Experiment (GTE) and was conducted during the summer of 1989. The intercomparisons were conducted on the Wallops Electra aircraft during flights from Wallops Island, Virginia, and Natal, Brazil. Sulfur measurements intercompared included sulfur dioxide (SO2), dimethylsulfide (DMS), hydrogen sulfide (H2S), carbon disulfide (CS2), and carbonyl sulfide (OCS). Measurement techniques ranged from filter collection systems with post-flight analyses to mass spectrometer and gas chromatograph systems employing various methods for measuring and identifying the sulfur gases during flight. Sampling schedules for the techniques ranged from integrated collections over periods as long as 50 minutes to one- to three-minute samples every ten or fifteen minutes. Several of the techniques provided measurements of more than one sulfur gas. Instruments employing different detection principles were involved in each of the sulfur intercomparisons. Also included in the intercomparison measurement scenario were a host of supporting measurements (i.e., ozone, nitrogen oxides, carbon monoxide, total sulfur, aerosols, etc.) for purposes of: (1) interpreting results (i.e., correlation of any noted instrument disagreement with the chemical composition of the measurement environment); and (2) providing supporting chemical data to meet CITE-3 science objectives of studying ozone/sulfur photochemistry, diurnal cycles, etc. The results of the intercomparison study are briefly discussed.

Gregory, Gerald L.; Hoell, James M., Jr.; Davis, Douglas D.

1991-01-01

62

Benefits and Costs From Sulfur Dioxide Trading: A Distributional Analysis  

Microsoft Academic Search

Prior to the passage of Title IV of the 1990 Clean Air Act Amendments (CAAA), there had been a lively debate involving Congress,\\u000a the U.S. Environmental Protection Agency (EPA), and academics, about the need for reducing sulfur dioxide (SO2) emissions due to the problem of acid rain. In addition to domestic pressure, Canada was putting political pressure on the\\u000a United

Ronald J. Shadbegian; Wayne Gray; Cynthia Morgan

2005-01-01

63

An intercomparison of aircraft instrumentation for tropospheric measurements of sulfur dioxide  

NASA Technical Reports Server (NTRS)

As part of the NASA Tropospheric Chemistry Program, a series of field intercomparisons have been conducted to evaluate the state-of-the art for measuring key tropospheric species. One of the objectives of the third intercomparison campaign in this series, Chemical Instrumentation Test and Evaluation 3 (CITE 3), was to evaluate instrumentation for making reliable tropospheric aircraft measurements of sulfur dioxide, dimethyl sulfide, hydrogen sulfide, carbon disulfide, and carbonyl sulfide. This paper reports the results of the intercomparisons of five sulfur dioxide measurement methods ranging from filter techniques, in which samples collected in flight are returned to the laboratory for analyses (chemiluminescent or ion chromatographic), to near real-time, in-flight measurements via gas chromatographic, mass spectrometric, and chemiluminescent techniques. All techniques showed some tendency to track sizeable changes in ambient SO2 such as those associated with altitude changes. For SO2 mixing ratios in the range of 200 pptv to a few ppbv, agreement among the techniques varies from about 30% to several orders of magnitude, depending upon the pair of measurements intercompared. For SO2 mixing ratios less than 200 pptv, measurements from the techniques are uncorrelated. In general, observed differences in the measurement of standards do not account for the flight results. The CITE 3 results do not unambiguously identify one or more of the measurement techniques as providing valid or invalid SO2 measurements, but identify the range of 'potential' uncertainty in SO2 measurements reported by currently available instrumentation and as measured under realistic aircraft environments.

Gregory, Gerald L.; Davis, Douglas D.; Beltz, Nobert; Bandy, Alan R.; Ferek, Ronald J.; Thornton, Donald C.

1993-01-01

64

Behavioral modification of estuarine fish exposed to sulfur dioxide  

SciTech Connect

This study was designed to determine the avoidance responses of juvenile striped bass (Morone saxatilis) and Atlantic menhaden (Brevoortia tyrannus) exposed to sulfur dioxide (sulfite) at acclimation temperatures of 15, 20, 25, and 30/sup 0/C. Predictive models were developed and compared for each species at each acclimation temperature. Striped bass avoided 2.2, 2.3, 3.0, and 3.5 mg sulfite/l at 15, 20, 25, and 30/sup 0/C, respectively. Atlantic menhaden avoided 3.2, 3.6, 2.9, and 3.0 mg sulfite/l at acclimation temperatures of 15, 20, 25, and 30/sup 0/C, respectively. Acclimation temperature was an important factor influencing the avoidance response of each species exposed to sulfur dioxide. Striped bass avoided lower concentrations of sulfite than Atlantic menhaden at 15 and 20/sup 0/C. Both species avoided approximately the same concentration of sulfite at 25/sup 0/C. Atlantic menhaden avoided lower concentrations of sulfur dioxide than striped bass at 30/sup 0/C. 24 references, 2 figures, 3 tables.

Hall, L.W. Jr.; Burton, D.T.; Graves, W.C.; Margrey, S.L.

1984-01-01

65

Behavioral modification of estuarine fish exposed to sulfur dioxide.  

PubMed

This study was designed to determine the avoidance responses of juvenile striped bass (Morone saxatilis) and Atlantic menhaden (Brevoortia tyrannus) exposed to sulfur dioxide (sulfite) at acclimation temperatures of 15, 20, 25, and 30 degrees C. Predictive models were developed and compared for each species at each acclimation temperature. Striped bass avoided 2.2, 2.3, 3.0, and 3.5 mg sulfite/l at 15, 20, 25, and 30 degrees C, respectively. Atlantic menhaden avoided 3.2, 3.6, 2.9, and 3.0 mg sulfite/l at acclimation temperatures of 15, 20, 25, and 30 degrees C, respectively. Acclimation temperature was an important factor influencing the avoidance response of each species exposed to sulfur dioxide. Striped bass avoided lower concentrations of sulfite than Atlantic menhaden at 15 and 20 degrees C. Both species avoided approximately the same concentration of sulfite at 25 degrees C. Atlantic menhaden avoided lower concentrations of sulfur dioxide than striped bass at 30 degrees C. PMID:6492212

Hall, L W; Burton, D T; Graves, W C; Margrey, S L

1984-01-01

66

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

SciTech Connect

We propose a process that uses sulfur dioxide from coal combustion as a raw material to synthesize polymeric ferric sulfate (PFS), a water treatment agent. The process uses sodium chlorate as an oxidant and ferrous sulfate as an absorbent. The major chemical mechanisms in this reaction system include oxidation, hydrolysis, and polymerization. Oxidation determines sulfur conversion efficiency while hydrolysis and polymerization control the quality of product. Many factors, including SO{sub 2} inlet concentration, flow rate of simulated flue gas, reaction temperature, addition rate of oxidant and stirring rate, may affect the efficiencies of SO{sub 2} removal. Currently, the effects of SO{sub 2} inlet concentration, the flow rate of simulated flue gas and addition rate of flue gas on removal efficiencies of SO{sub 2}, are being investigated. Experiments shown in this report have demonstrated that the conversion efficiencies of sulfur dioxide with ferrous sulfate as an absorbent are in the range of 60-80% under the adopted process conditions. However, the conversion efficiency of sulfur dioxide may be improved by optimizing reaction conditions to be investigated. Partial quality indices of the synthesized products, including Fe{sup 2+} concentration and total iron concentration, have been evaluated.

Robert C. Brown; Maohong Fan

2001-12-01

67

Chemistry of sulfur-containing molecules on Au( 1 1 1 ): thiophene, sulfur dioxide, and methanethiol adsorption  

NASA Astrophysics Data System (ADS)

The interactions of three sulfur-containing molecules (C 4H 4S, SO 2, CH 3SH) with a clean Au(1 1 1) surface have been studied with a combination of thermal desorption spectroscopy (TDS) and synchrotron-based high-resolution soft X-ray photoelectron spectroscopy. The adsorption and reactivity of the three molecules on Au(1 1 1) are very different. Thiophene adsorbs molecularly on Au(1 1 1) at 100 K and desorbs completely below 330 K without further decomposition. In the submonolayer range, three different adsorption states for chemisorbed thiophene are identified in TDS. It is suggested that thiophene preferably adsorbs on the defect sites at the lowest exposure. After the defect sites are saturated, the change from a flat-lying geometry to a tilted adsorption configuration follows as the exposure increases. Sulfur dioxide also does not decompose on Au(1 1 1). For SO 2 adsorption at 100 K, in addition to the multilayer desorption feature (˜130 K), only one distinct monolayer peak with a tail extending to higher temperature appears in TDS. The desorption temperature difference between the SO 2 monolayer and multilayer is only 15 K, indicating a weak binding between SO 2 and Au. For methanethiol adsorption on Au(1 1 1) at 100 K, three desorption states appear in the submonolayer range for the parent thiol. All of them appear below 300 K. The only desorption products at higher temperature are methane or methyl radicals (˜540 K), and dimethyl disulfide (˜470 K). Apart from the intact methyl thiol molecule, which exists at low temperatures (?150 K), two inequivalent intermediate thiolates, are seen to coexist on Au(1 1 1) in the 150-400 K temperature range, with one of them existing as low as 100 K. Atomic sulfur is present on the surface from 200 to 950 K.

Liu, Gang; Rodriguez, José A.; Dvorak, Joseph; Hrbek, Jan; Jirsak, Tomas

2002-05-01

68

Modeling sulfur dioxide capture in a pulverized coal combustor  

SciTech Connect

The formation and capture of sulfur dioxide in a pulverized coal combustor is investigated. A two-dimensional, steady, axisymmetric code, PCGC-2 (Pulverized Coal Gasification and Combustion-two Dimensional), originally developed at Brigham Young University, has been used to simulate combustion of the pulverized coal. This paper represents part of a project to investigate simultaneously enhancing sulfur capture and particulate agglomeration in combustor effluents. Results from the code have been compared to experimental data obtained from MTCI`s (Manufacturing Technology and Conversion International) test pulse combustor, which generates sound pressure levels of {approximately}180 dB. The overall goal behind the pulse combustor program at MTCI is to develop combustors for stationary gas turbines that use relatively inexpensive coal-based fuels. This study attempts to model the capture of sulfur dioxide when injected into a pulse combustor firing micronized coal. While this work does not presume to model the complex gas flow-field generated by the pulsating flow, the effects of the acoustic field are expressed by increased heat and mass transfer to the particles (coal/sorbent) in question. A comprehensive calcination-sintering-sulfation model for single particles was used to model the capture of sulfur dioxide by limestone sorbent. Processes controlling sulfation are external heat and mass transfer, pore diffusion, diffusion through the product layer of CaSO{sub 4}, sintering, and calcination. The model was incorporated into the PCGC-2 program. Comparisons of exit concentrations of SO{sub 2} showed a fairly good agreement (within {approximately}10 percent) with the experimental results from MTCI.

Nair, R.B.; Yavuzkurt, S. [Pennsylvania State Univ., University Park, PA (United States)

1997-04-01

69

Synthesis and solution properties of a new sulfobetaine\\/sulfur dioxide copolymer and its use in aqueous two-phase polymer systems  

Microsoft Academic Search

The zwitterionic monomer, 3-(N,N-diallylammonio)propanesulfonate, was copolymerized with sulfur dioxide in dimethyl sulfoxide using azo-bis-isobutyronitrile (AIBN) to afford the polysulfobetaine (PSB) copolymer in excellent yields. The PSB was converted into the corresponding anionic polyelectrolyte (APE) by treatment with 1equiv. of sodium hydroxide. The solution properties of PSB and APE were investigated by potentiometric and viscometric techniques. The critical (minimum) salt concentrations

Sk. Asrof Ali; Hasan A Al-Muallem; Mohammad A. J Mazumder

2003-01-01

70

Testing of an improved lithium-sulfur dioxide battery for aircrew life support equipment  

Microsoft Academic Search

This report presents the results of in-house testing of lithium-sulfur dioxide cells. The report includes performance testing of an engineering prototype design of lithium-sulfur dioxide cells and the performance characterization, storage evaluations and abuse test behavior of the pilot production cell design. Several design modifications occurred during the development of this lithium-sulfur dioxide cell technology which significantly changed their performance.

J. S. Cloyd

1982-01-01

71

Effects of sulfur dioxide on lichen lipids and fatty acids.  

PubMed

Lipids and fatty acids were studied in some lichen species after exposure to 1 ppm of aqueous sulfur dioxide. The changes in lipid composition are specific to the lichen species tested. The exposure of lichens to SO2 resulted in a slight reduction of the total phospholipid content. The amount of betaine lipid diacylglyceryltrimethylhomoserine was increased in Stereocaulon paschale, but the level of this lipid was not changed in Peltigera aphthosa. An increase in fatty acid unsaturation in lichens in response to the effect of SO2 probably has adaptive significance. PMID:9986914

Bychek-Guschina, I A; Kotlova, E R; Heipieper, H

1999-01-01

72

Effects of acid rain and sulfur dioxide on marble dissolution  

USGS Publications Warehouse

Acid precipitation and the dry deposition of sulfur dioxide (SO2) accelerate damage to carbonate-stone monuments and building materials. This study identified and quantified environmental damage to a sample of Vermont marble during storms and their preceding dry periods. Results from field experiments indicated the deposition of SO2 gas to the stone surface during dry periods and a twofold increase in marble dissolution during coincident episodes of low rain rate and decreased rainfall pH. The study is widely applicable to the analysis of carbonate-stone damage at locations affected by acid rain and air pollution.

Schuster, Paul F.; Reddy, Michael M.; Sherwood, Susan I.

1994-01-01

73

Auction design and the market for sulfur dioxide emissions  

SciTech Connect

Title IV of the Clean Air Act Amendments of 1990 created a market for electric utility emissions of sulfur dioxide (SO{sub 2}). Recent papers have argued that flaws in the design of the auctions that are part of this market have adversely affected its performance. These papers incorrectly assume that trade can only occur at auctions, however. Our empirical analysis of the SO{sub 2} emissions market shows that the auctions have become a small part of a relatively efficient market and that the auction design problems that have attracted the most attention have had no effect on actual market prices.

Joskow, P.L.; Schmalensee, R.; Bailey, E.M.

1997-12-31

74

Low level atmospheric sulfur dioxide pollution and childhood asthma  

SciTech Connect

Quarterly analysis (1983-1987) of childhood asthma in Hong Kong from 13,620 hospitalization episodes in relation to levels of pollutants (SO{sub 2}, NO{sub 2}, NO, O{sub 3}, TSP, and RSP) revealed a seasonal pattern of attack rates that correlates inversely with exposure to sulfur dioxide (r = -.52, P less than .05). The same cannot be found with other pollutants. Many factors may contribute to the seasonal variation of asthma attacks. We speculate that prolonged exposure (in terms of months) to low level SO{sub 2} is one factor that might induce airway inflammation and bronchial hyperreactivity and predispose to episodes of asthma.

Tseng, R.Y.; Li, C.K. (Chinese Univ. of Hong Kong (Hong Kong))

1990-11-01

75

Dimethyl sulfide air-sea fluxes and biogenic sulfur as a source of new aerosols in the Arctic fall  

NASA Astrophysics Data System (ADS)

Dimethyl sulfide (DMS) and its oxidation products, which have been proposed to provide a climate feedback mechanism by affecting aerosol and cloud radiative properties, were measured on board the Canadian Coast Guard ship Amundsen in sampling campaigns in the Arctic in the fall of 2007 and 2008. DMS flux was calculated based on the surface water measurements and yielded 0.1-2.6 ?mol m-2 d-1 along the Northwest Passage in 2007 and 0.2-1.3 ?mol m-2 d-1 along Baffin Bay in 2008. DMS oxidation products, sulfur dioxide (SO2), methane sulfonic acid (MSA), and sulfate in aerosols were also measured. The amounts of biogenic SO2 and sulfate were approximated using stable isotope apportionment techniques. Calculating the threshold amount of SO2 needed for significant new particle formation from the formulation by Pirjola et al. (1999), the study suggests that instances of elevated biogenic SO2 concentrations (between 8 and 9 September 2008) derived using conservative assumptions may have been sufficient to form new aerosols in clean air conditions in the Arctic region.

Rempillo, Ofelia; Seguin, Alison Michelle; Norman, Ann-Lise; Scarratt, Michael; Michaud, Sonia; Chang, Rachel; Sjostedt, Steve; Abbatt, Jon; Else, Brent; Papakyriakou, Tim; Sharma, Sangeeta; Grasby, Steve; Levasseur, Maurice

2011-09-01

76

Sulfur Dioxide and Emergency Department Visits for Stroke and Seizure  

PubMed Central

The purpose of this study was to assess an association between ambient sulfur dioxide and the number of emergency department (ED) visits for ischemic stroke and seizure. The study used data collected in a Vancouver (Canada) hospital in the years 1999–2003. Daily ED visits diagnosed as ministroke, stroke, or seizure were investigated using the case-crossover technique. Conditional logistic regression models were applied to estimate the odds ratios (ORs) and their respective 95% confidence intervals (CIs). The models included temperature and relative humidity in the form of natural splines. The results were reported for an increase in interquartile range ((IQR), IQR = 1.9 ppb for SO2). Positive and statistically significant associations were obtained for SO2 and ischemic stroke for all patients (OR = 1.12; CI 1.02, 1.23; lag 3) and for female patients (OR = 1.17; CI 1.01, 1.33; lag 0). In the case of ED visits for seizure, for female patients the results were also statistically significant (OR = 1.15; CI 1.02, 1.28; lag 1 and OR = 1.18; CI 1.05, 1.32; lag 2). These findings suggest that cases of ischemic cerebrovascular accidents are associated with acute exposure to ambient sulfur dioxide. PMID:22577602

Szyszkowicz, Mieczys?aw; Porada, Eugeniusz; Tremblay, Neil; Grafstein, Eric

2012-01-01

77

Remote Sensing of Ammonia and Sulfur Dioxide from On-Road Light  

E-print Network

Remote Sensing of Ammonia and Sulfur Dioxide from On-Road Light Duty Vehicles D A N I E L A . B U R-road, fuel- based mass emissions of ammonia and sulfur dioxide from vehicles of known make, model year, and fuel type. Ammonia is the first pollutant observed for which the emissions decrease with increasing

Denver, University of

78

Advances in Monitoring of Global Sulfur Dioxide Sources with Aura\\/OMI  

Microsoft Academic Search

Sulfur dioxide is produced by volcanoes, smelters, and from combustion of fossil fuels. It is rapidly oxidized to sulfate aerosols, which affect climate by reflecting sunlight. Volcanic eruption sulfur dioxide masses have been measured for nearly 30 years with Total Ozone Mapping Spectrometer (TOMS) instruments. Smaller sources were immeasurable because the TOMS selection of six discrete wavelengths was far from

Arlin Krueger; Nick Krotkov; Kai Yang; Simon Carn

2008-01-01

79

Process for purifying a sulfur dioxide containing gas by washing with an ammonia aqueous solution  

Microsoft Academic Search

Process for purifying a sulfur dioxide containing gas, by washing with an ammonia aqueous solution is comprised of the following steps: (a) contacting a sulfur dioxide containing gas with ammonia and\\/or ammonium sulfite in the presence of water, to form a solution containing ammonium bisulfite and\\/or sulfite; (b) reacting at least a portion of the solution obtained in step (a)

A. Deschamps; S. Franckowiak; P. Renault

1979-01-01

80

Passive colorimetric dosimeter tubes for ammonia, carbon monoxide, carbon dioxide, hydrogen sulfide, nitrogen dioxide, and sulfur dioxide  

SciTech Connect

Colorimetric, stain length, personal dosimeters operating by gas diffusion have been developed to determine worker exposure for up to an 8-h period for several inorganic airborne contaminants in the range of their threshold limit values. Length of stain, colorimetric dosimeters have been made for the detection of ammonia (NH/sub 3/), carbon monoxide (CO), carbon dioxide (CO/sub 2/), hydrogen sulfide (H/sub 2/S), nitrogen dioxide (NO/sub 2/), and sulfur dioxide (SO/sub 2/) in air. For each gas detection system, the sampler depends on the transfer of the gas by diffusion into a glass tube containing a colorimetric length of stain indicator. The stain length developed in a given period of time is compared to a calibration chart to determine, on the spot, the average gas concentration to which the dosimeter has been exposed. These dosimeters are known by the trade name Vapor Gard.

McKee, E.S.; Pritts, I.M.

1981-08-01

81

Passive colorimetric dosimeter tubes for ammonia, carbon monoxide, carbon dioxide, hydrogen sulfide, nitrogen dioxide and sulfur dioxide  

SciTech Connect

Colorimetric, stain length, personal dosimeters operating by gas diffusion have been developed to determine worker exposure for up to an eight-hour period for several inorganic airborne contaminants in the range of their Threshold Limit Values. Length of stain, colorimetric dosimeters have been made for the detection of ammonia (NH/sub 3/), carbon monoxide (CO), carbon dioxide (CO/sub 2/), hydrogen sulfide (H/sub 2/S), nitrogen dioxide (NO/sub 2/), and sulfur dioxide (SO/sub 2/) in air. For each gas detection system, the sampler depends on the transfer of the gas by diffusion into a glass tube containing a colorimetric length of stain indicator. The stain length developed in a given period of time is compared to a calibration chart to determine, on the spot, the average gas concentration to which the dosimeter has been exposed. These dosimeters are known by the trade name Vapor Gard.

McConnaughey, P.W.; McKee, E.S.; Pritts, I.M.

1985-07-01

82

Response of radish to nitrogen dioxide, sulfur dioxide, and ozone, alone and in combination  

SciTech Connect

Effects on radish (Raphanus sativus L.) cv. Cherry Belle of nitrogen dioxide (NO/sub 2/), sulfur dioxide (SO/sub 2/), and ozone (O/sub 3/) alone and in combination at 0.2 and 0.4 ppM of each pollutant were studied. There was no difference in foilage or root weight of radish between exposure durations of 3 to 6 hours, and no significant interaction of hours with air pollutant and concentration. Ozone reduced root dry weight more at 0.4 ppM than at 0.2 ppM. Sulfur dioxide depressed the root/shoot ratio at both 0.2 and 0.4 ppM; however, when NO/sub 2/ and SO/sub 2/ were both present there was synergistic depression of the root/shoot ratio at 0.4 ppM. The average O/sub 3/-induced reduction in root weight of radish (1.75 g fresh and 101 mg dry, per plant) was additive in the presence of NO/sub 2/ and SO/sub 2/. The weight of the root was reduced even though the foilage was the direct receptor of the pollutant stress.

Reinert, R.A.; Gray, T.N.

1981-04-01

83

New passive colorimetric air monitoring badge system for ammonia, sulfur dioxide, and nitrogen dioxide  

SciTech Connect

A new passive colorimetric air monitoring badge system was developed to determine the time-weighted average (TWA) concentration of specific inorganic vapor contaminants in air. The system consists of a small passive badge which either can be worn by employees for personal monitoring or used as an area monitor and a portable colorimetric readout instrument which determines the exposure dose in ppM-hours. To date, systems have been developed for ammonia, sulfur dioxide, and nitrogen dioxide, and they will meet or exceed both NIOSH and OSHA accuracy requirements. The overall performance of these systems, based on laboratory tests designed to show overall accuracy, linearity, and environmental effects, is described. Field test results are also presented.

Kring, E.V.; Lautenberger, W.J.; Baker, W.B.; Douglas, J.J.; Hoffman, R.A.

1981-05-01

84

Gaseous sulfuric acid and sulfur dioxide measurements in the Arctic troposphere and lower stratosphere - Implications for hydroxyl radical abundances  

Microsoft Academic Search

Measurements of gaseous sulfuric acid and sulfur dioxide were made in the winter Arctic troposphere and lower stratosphere using aircraft-borne mass spectrometers. The measurements, covering altitudes between 3.5 and 11.4 km, took place on 14 and 18 February, 1987 in northern Scandinavia. The abundance of H2SO4 was around 0.01 to 0.06 pptv (parts per trillion by volume), and the measured

O. Moehler; F. Arnold

1992-01-01

85

Impact of sulfur dioxide oxidation by Stabilized Criegee Intermediate on sulfate  

EPA Science Inventory

We revise the Carbon Bond chemical mechanism to explicitly represent three Stabilized Criegee Intermediates (SCIs) and their subsequent reactions with sulfur dioxide, water monomer, and water dimer, and incorporate the reactions into the Community Multiscale Air Quality model. Th...

86

Explaining low sulfur dioxide allowance prices : the effect of expectation errors and irreversibility  

E-print Network

The low price of allowances has been a frequently noted featured of the implementation of the sulfur dioxide emissions market of the U.S. Acid Rain Program. This paper presents theoretical and numerical analyses that explain ...

Montero, Juan-Pablo

1998-01-01

87

GROUND-BASED SULFUR DIOXIDE MEASUREMENTS WITHIN A COPPER SMELTER PLUME - ANACONDA, MONTANA  

EPA Science Inventory

The Monitoring Operations Division (MOD) of the Environmental Monitoring and Support Laboratory - Las Vegas developed a mobile sulfur dioxide (SO2) instrument package for use in the remote, rugged terrain surrounding The Anaconda Company's copper smelter at Anaconda, Montana. The...

88

77 FR 46295 - Extension of Deadline for Promulgating Designations for the 2010 Primary Sulfur Dioxide National...  

Federal Register 2010, 2011, 2012, 2013, 2014

...initial area designations for the primary sulfur dioxide (SO 2 ) national ambient...to these commenters, we explained our modified expectations at that time for issuing...tribal agencies that described the EPA's modified expectations regarding some SO 2...

2012-08-03

89

The excited state geometry associated with the 2900A absorption spectrum of sulfur dioxide  

E-print Network

O THE EXCITED STATE GEOMETRY ASSOCIATED WITH THE 2900A ABSORPTION SPECTRUM OF SULFUR DIOXIDE A Thesis By DAVID ROBERT SMITH& JR. Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August, 1962 Major Subject: Physics THE EXCITED STATE GEOMETRY ASSOCIATED WITH THE 2900A ABSORPTION SPECTRUM OF SULFUR DIOXIDE A Thesis By DAVID ROBERT SMITH, JR. Approved as to style and content by...

Smith, David Robert, Jr

1962-01-01

90

Ambient air concentration of sulfur dioxide affects flight activity in bees  

SciTech Connect

Three long-term (16 to 29 days) low-level (0.14 to 0.28 ppM) sulfur dioxide fumigations showed that exposure tothis gas has deleterious effects on male sweat bees (Lasioglossum zephrum). Although effects on mortality were equivocal, flight activity was definitely reduced. Because flight is necessary for successful mating behavior, the results suggest that sulfur dioxide air pollution could adversely affect this and doubtless other terrestrial insects.

Ginevan, M.E.; Lane, D.D.; Greenberg, L.

1980-10-01

91

Adsorption of sulfur dioxide from coal combustion gases on natural zeolite  

SciTech Connect

In this study, better efficiency of SO{sub 2} removal in flue gas from lignite coal combustion by adding of NZ in the gas phase was achieved. Natural zeolite was exposed to flue gas containing sulfur dioxide at varying conditions of relative humidity and temperature. It was found that the amount of sulfate on the zeolite increased with increasing relative humidity and temperature. The percents of adsorbed sulfur dioxide were 86, 74, 56, and 35, while the values of relative humidity (RH) were 75, 60, 45, and 30% for 40 minutes, respectively. The percents of adsorbed sulfur dioxide sharply increased within the first 40 min for the values of RH were 75 and 60, and after 40 min, slightly increased, then reached a plateau. In general, as increasing the RH increased the amount of sulfur dioxide adsorbed by natural zeolite. The amounts of adsorbed sulfur dioxide increased with exposure time. It increased and reached 30.2 mg/g for 40 min. After 40 min, it slightly increased and then reached a plateau. The NZ adsorbs 35.1 mg SO{sub 2} per gram adsorbent with 75% RH at 298 K from a simulated coal combustion flue gas. The amounts of adsorbed sulfur dioxide increased with increasing temperature. The NZ adsorbs 71.5 mg SO{sub 2} per gram adsorbent with 75% RH for 100 min exposure time from the flue gas mixture.

Demirbas, A. [Selcuk University, Konya (Turkey). Dept. for Chemical Engineering

2006-10-15

92

Smart battery controller for lithium sulfur dioxide batteries  

NASA Astrophysics Data System (ADS)

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

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

1992-08-01

93

Methane sulfonic acid-enhanced formation of molecular clusters of sulfuric acid and dimethyl amine  

NASA Astrophysics Data System (ADS)

Over oceans and in coastal regions, methane sulfonic acid (MSA) is present in substantial concentrations in aerosols and in the gas phase. We present an investigation into the effect of MSA on sulfuric acid- and dimethyl amine (DMA)-based cluster formation rates. From systematic conformational scans and well-tested ab initio methods, we optimise the structures of all MSAx (H2SO4)yDMAz clusters where x + y ≤ 3 and z ≤ 2. The resulting thermodynamic data are used in the Atmospheric Cluster Dynamics Code, and the effect of MSA is evaluated by comparing ternary MSA-H2SO4-DMA cluster formation rates to binary H2SO4-DMA cluster formation rates. Within the range of atmospherically relevant MSA concentrations, we find that MSA may increase cluster formation rates by up to 1 order of magnitude, although typically, the increase will be less than 300 % at 258 K, less than 100 % at 278 K and less than 15 % at 298 K. The results are rationalised by a detailed analysis of the main growth paths of the clusters. We find that MSA-enhanced clustering involves clusters containing one MSA molecule, while clusters containing more than one MSA molecule do not contribute significantly to the growth.

Bork, N.; Elm, J.; Olenius, T.; Vehkamäki, H.

2014-11-01

94

Atmospheric measurements of carbonyl sulfide, dimethyl sulfide, and carbon disulfide using the electron capture sulfur detector  

NASA Technical Reports Server (NTRS)

Measurements of atmospheric dimethyl sulfide (DMS), carbonyl sulfide (COS), and carbon disulfide (CS2) were conducted over the Atlantic Ocean on board the NASA Electra aircraft during the Chemical Instrumentation Test and Evaluation (CITE 3) project using the electron capture sulfur detector (ECD-S). The system employed cryogenic preconcentration of air samples, gas chromatographic separation, catalytic fluorination, and electron capture detection. Samples collected for DMS analysis were scrubbed of oxidants with NaOH impregnated glass fiber filters to preconcentration. The detection limits (DL) of the system for COS, DMS, and CS2 were 5, 5, and 2 ppt, respectively. COS concentrations ranged from 404 to 603 ppt with a mean of 489 ppt for measurements over the North Atlantic Ocean (31 deg N to 41 deg N), and from 395 to 437 ppt with a mean of 419 ppt for measurements over the Tropical Atlantic Ocean (11 deg S to 2 deg N). DMS concentrations in the lower marine boundary layer, below 600-m altitude, ranged from below DL to 150 ppt from flights over the North Atlantic, and from 9 to 104 ppt over the Tropical Atlantic. CS2 concentrations ranged from below DL to 29 ppt over the North Atlantic. Almost all CS2 measurements over the Tropical Atlantic were below DL.

Johnson, James E.; Bates, Timothy S.

1993-01-01

95

NATIONAL PERFORMANCE AUDIT PROGRAM: 1979 PROFICIENCY SURVEYS FOR SULFUR DIOXIDE, NITROGEN DIOXIDE, CARBON MONOXIDE, SULFATE, NITRATE, LEAD AND HIGH VOLUME FLOW  

EPA Science Inventory

The Quality Assurance Division of the Environmental Monitoring Systems Laboratory, Research Triangle Park, North Carolina, administers semiannual Surveys of Analytical Proficiency for sulfur dioxide, nitrogen dioxide, carbon monoxide, sulfate, nitrate and lead. Sample material, s...

96

Advanced byproduct recovery: Direct catalytic reduction of sulfur dioxide to elemental sulfur. Fourth quarterly technical progress report  

SciTech Connect

The team of Arthur D. Little, Tufts University and Engelhard Corporation are conducting Phase 1 of a four and a half year, two-phase effort to develop and scale-up an advanced byproduct recovery technology that is a direct, single-stage, catalytic process for converting sulfur dioxide to elemental sulfur. This catalytic process reduces SO{sub 2} over a fluorite-type oxide (such as ceria and zirconia). The catalytic activity can be significantly promoted by active transition metals, such as copper. More than 95% elemental sulfur yield, corresponding to almost complete sulfur dioxide conversion, was obtained over a Cu-Ce-O oxide catalyst as part of an on-going DOE-sponsored, University Coal Research Program. This type of mixed metal oxide catalyst has stable activity, high selectivity for sulfur production, and is resistant to water and carbon dioxide poisoning. Tests with CO and CH{sub 4} reducing gases indicate that the catalyst has the potential for flexibility with regard to the composition of the reducing gas, making it attractive for utility use. The performance of the catalyst is consistently good over a range of SO{sub 2} inlet concentration (0.1 to 10%) indicating its flexibility in treating SO{sub 2} tail gases as well as high concentration streams.

NONE

1997-01-01

97

Distribution of Hydrogen Peroxide, Carbon Dioxide, and Sulfuric Acid in Europa's Icy Crust  

NASA Technical Reports Server (NTRS)

Galileo's Near Infrared Mapping Spectrometer (NIMS) detected hydrogen peroxide, carbon dioxide and a hydrated material on Europa's surface, the latter interpreted as hydrated sulfuric acid (H2SO4*nH2O) or hydrated salts. Related compounds are molecular oxygen, sulfur dioxide, and two chromophores, one that is dark in the ultraviolet(UV) and concentrated on the trailing side, the other brighter in the UV and preferentially distributed in the leading hemisphere. The UV-dark material has been suggested to be sulfur.

Carlson, R. W.

2004-01-01

98

Growth of radish and marigold following repeated exposure to nitrogen dioxide, sulfur dioxide, and ozone  

SciTech Connect

Radish and marigold plants were exposed to 0.3 ppM of nitrogen dioxide (NO/sub 2/), sulfur dioxide (SO/sub 2/), and /or ozone (O/sub 3/) nine times during a 3-wk period. No interactions among NO/sub 2/, SO/sub 2/, and O/sub 3/ were detected in measurement of radish foliage and root dry weight. Treatments containing O/sub 3/ reduced radish foliage and root (hypocotyl) dry weight 356 and 531 mg/plant, respectively. Interactions among NO/sub 2/, SO/sub 2/ and O/sub 3/ occurred in shoots and roots of marigold. SO/sub 2/ alone reduced marigold shoot and root dry weight, but this effect was reversed in the presence of O/sub 3/. The suppressive effect of SO/sub 2/ on root weight was also reversed by NO/sub 2/. Treatments containing SO/sub 2/ reduced dry flower weight 0.17 g/plant, but effects of the pollutant interactions observed in shoots and roots were not present. 8 references, 2 tables.

Reinert, R.A.; Sanders, J.S.

1982-02-01

99

Growth of radish and marigold following repeated exposure to nitrogen dioxide, sulfur dioxide, and ozone  

SciTech Connect

Radish and marigold plants were exposed to 0.3 ppm of nitrogen dioxide (NO/sub 2/), sulfur dioxide (SO/sub 2/), and/or ozone (O/sub 3/) nine times during a 3-wk period. No interactions among NO/sub 2/, SO/sub 2/, and O/sub 3/ were detected in measurement of radish foliage and root dry weight. Treatments containing O/sub 3/ reduced radish foliage and root (hypocotyl) dry weight 356 and 531 mg/plant, respectively. Interactions among NO/sub 2/, SO/sub 2/, and O/sub 3/ occurred in shoots and roots of marigold. SO/sub 2/ alone reduced marigold shoot and root dry weight, but this effect was reversed in the presence of O/sub 3/. The suppressive effect of SO/sub 2/ on root weight was also reversed by NO/sub 3/. Treatments containing SO/sub 2/ reduced dry flower weight 0.17 g/plant, but effects of the pollutant interactions observed in shoots and roots were not present.

Reinert, R.A.; Sanders, J.S.

1982-02-01

100

Postnatal Sulfur Dioxide Exposure Reversibly Alters Parasympathetic Regulation of Heart Rate  

PubMed Central

Perinatal sulfur dioxide exposure disrupts parasympathetic regulation of cardiovascular activity. Here, we examine the relative risks of prenatal versus postnatal exposure to the air pollutant, and the reversibility of the cardiovascular effects. Two groups of animals were used for this study. For prenatal exposure, pregnant Sprague-Dawley dams were exposed to 5 parts per million sulfur dioxide for 1 hour daily throughout gestation, and with their pups upon birth to medical-grade air through 6 days postnatal. For postnatal exposure, dams were exposed to air, and upon delivery along with their pups to 5 parts per million sulfur dioxide through postnatal day 6. Electrocardiograms were recorded from pups on postnatal day 5 to examine changes in heart rate. Whole-cell patch-clamp electrophysiology was used to examine changes in neurotransmission to cardiac vagal neurons upon sulfur dioxide exposure. Postnatal sulfur dioxide exposure diminished glutamatergic neurotransmission to cardiac vagal neurons by 40.9% and increased heart rate, whereas prenatal exposure altered neither of these properties. When postnatal exposure concluded on postnatal day 5, excitatory neurotransmission remained decreased through day 6, and returned to basal levels by day 7. Electrocardiograms showed that heart rate remained elevated through day 6 and recovered by day 7. Upon activation of the parasympathetic diving reflex, the response was significantly blunted by postnatal sulfur dioxide exposure through day 7 but recovered by day 8. Postnatal, but not prenatal, exposure to sulfur dioxide can disrupt parasympathetic regulation of cardiovascular activity. Neonates can recover from these effects within 2–3 days of discontinued exposure. PMID:23774227

Woerman, Amanda L.; Mendelowitz, David

2014-01-01

101

Testing of an improved lithium-sulfur dioxide battery for aircrew life support equipment. Final report Jan 79-Oct 81  

Microsoft Academic Search

This report presents the results of in-house testing of lithium-sulfur dioxide cells. The report includes performance testing of an engineering prototype design of lithium-sulfur dioxide cells and the performance characterization, storage evaluations and abuse test behavior of the pilot production cell design. Several design modifications occurred during the development of this lithium-sulfur dioxide cell technology which significantly changed their performance.

Cloyd

1982-01-01

102

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

SciTech Connect

Absorption of sulfur dioxide from a simulated flue gas was investigated for the production of polymeric ferric sulfate (PFS), a highly effective coagulant useful in treatment of drinking water and wastewater. The reaction for PFS synthesis took place near atmospheric pressure and at temperatures of 30-80 C. SO{sub 2} removal efficiencies greater than 90% were achieved, with ferrous iron concentrations in the product less than 0.1%. A factorial analysis of the effect of temperature, oxidant dosage, SO{sub 2} concentration, and gas flow rate on SO{sub 2} removal efficiency was carried out, and statistical analyses are conducted. The solid PFS was also characterized with different methods. Characterization results have shown that PFS possesses both crystalline and non-crystalline structure. The kinetics of reactions among FeSO{sub 4} {center_dot} 7H{sub 2}O, NaHSO{sub 3} and NaClO{sub 3} was investigated. The PFS product was used in pilot-scale tests at a municipal water treatment facility and gave good results in removal of turbidity and superior results in removal of disinfection byproduct precursors (TOC, DOC, UV-254) when compared with equal doses of ferric chloride.

Robert C. Brown; Maohong Fan; Adrienne Cooper

2002-10-01

103

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

SciTech Connect

Absorption of sulfur dioxide from a simulated flue gas was investigated for the production of polymeric ferric sulfate (PFS), a highly effective coagulant useful in treatment of drinking water and wastewater. The reaction for PFS synthesis took place near atmospheric pressure and at temperatures of 30-80 C. SO{sub 2} removal efficiencies greater than 90% were achieved, with ferrous iron concentrations in the product less than 0.1%. A factorial analysis of the effect of temperature, oxidant dosage, SO{sub 2} concentration, and gas flow rate on SO{sub 2} removal efficiency was carried out, and statistical analyses are conducted. The solid PFS was also characterized with different methods. Characterization results have shown that PFS possesses both crystalline and non-crystalline structure. The kinetics of reactions among FeSO{sub 4} {center_dot} 7H{sub 2}O, NaHSO{sub 3} and NaClO{sub 3} was investigated. Characterizations of dry PFS synthesized from SO{sub 2} show the PFS possesses amorphous structure, which is desired for it to be a good coagulant in water and wastewater treatment. A series of lab-scale experiments were conducted to evaluate the performance of PFS synthesized from waste sulfur dioxide, ferrous sulfate and sodium chlorate. The performance assessments were based on the comparison of PFS and other conventional and new coagulants for the removal of turbidity and arsenic under different laboratory coagulant conditions. Pilot plant studies were conducted at Des Moines Water Works in Iowa and at the City of Savannah Industrial and Domestic (I&D) Water Treatment Plant in Port Wentworth, Georgia. PFS performances were compared with those of conventional coagulants. The tests in both water treatment plants have shown that PFS is, in general, comparable or better than other coagulants in removal of turbidity and organic substances. The corrosion behavior of polymeric ferric sulfate (PFS) prepared from SO{sub 2} and ferric chloride (FC) were compared. Results showed that both temperature and concentration of the coagulants substantially impact corrosion rates. The corrosion rates increased with the increase of temperature and concentration. The results from a scanning electron microscope (SEM) showed that chloride caused more serious pitting than sulfate anion on both aluminum and steel specimens. Although SEM confirmed the existence of pitting corrosion, the results of weight loss indicated that the uniform corrosion predominate the corrosion mechanism, and pitting corrosion played a less important role. The test proved that PFS was less corrosive than FC, which may lead to the large-scale application of PFS in waste treatment. The kinetics of the new desulfurization process has been studied. The study results provide the theoretical guidance for improving sulfur removal efficiency and controlling the quality of PFS.

Robert C. Brown; Maohong Fan; Adrienne Cooper

2004-11-01

104

Statistical summary and trend evaluation of air quality data for Cleveland, Ohio in 1967 to 1971: Total suspended particulate, nitrogen dioxide, and sulfur dioxide  

NASA Technical Reports Server (NTRS)

Air quality data for Cleveland, Ohio, for the period of 1967 to 1971 were collated and subjected to statistical analysis. The total suspended particulate component is lognormally distributed; while sulfur dioxide and nitrogen dioxide are reasonably approximated by lognormal distributions. Only sulfur dioxide, in some residential neighborhoods, meets Ohio air quality standards. Air quality has definitely improved in the industrial valley, while in the rest of the city, only sulfur dioxide has shown consistent improvement. A pollution index is introduced which displays directly the degree to which the environmental air conforms to mandated standards.

Neustadter, H. E.; Sidik, S. M.; Burr, J. C., Jr.

1972-01-01

105

Sulfur dioxide emissions in China and sulfur trends in East Asia since 2000.  

SciTech Connect

With the rapid development of the economy, the sulfur dioxide (SO{sub 2}) emission from China since 2000 is of increasing concern. In this study, we estimate the annual SO{sub 2} emission in China after 2000 using a technology-based methodology specifically for China. From 2000 to 2006, total SO{sub 2} emission in China increased by 53%, from 21.7 Tg to 33.2 Tg, at an annual growth rate of 7.3%. Emissions from power plants are the main sources of SO{sub 2} in China and they increased from 10.6 Tg to 18.6 Tg in the same period. Geographically, emission from north China increased by 85%, whereas that from the south increased by only 28%. The emission growth rate slowed around 2005, and emissions began to decrease after 2006 mainly due to the wide application of flue-gas desulfurization (FGD) devices in power plants in response to a new policy of China's government. This paper shows that the trend of estimated SO{sub 2} emission in China is consistent with the trends of SO{sub 2} concentration and acid rain pH and frequency in China, as well as with the increasing trends of background SO{sub 2} and sulfate concentration in East Asia. A longitudinal gradient in the percentage change of urban SO{sub 2} concentration in Japan is found during 2000-2007, indicating that the decrease of urban SO{sub 2} is lower in areas close to the Asian continent. This implies that the transport of increasing SO{sub 2} from the Asian continent partially counteracts the local reduction of SO{sub 2} emission downwind. The aerosol optical depth (AOD) products of Moderate Resolution Imaging Spectroradiometer (MODIS) are found to be highly correlated with the surface solar radiation (SSR) measurements in East Asia. Using MODIS AOD data as a surrogate of SSR, we found that China and East Asia excluding Japan underwent a continuous dimming after 2000, which is in line with the dramatic increase in SO{sub 2} emission in East Asia. The trends of AOD from both satellite retrievals and model over East Asia are also consistent with the trend of SO2 emission in China, especially during the second half of the year, when sulfur contributes the largest fraction of AOD. The arrested growth in SO{sub 2} emissions since 2006 is also reflected in the decreasing trends of SO{sub 2} and SO{sub 4}{sup 2-} concentrations, acid rain pH values and frequencies, and AOD over East Asia.

Lu, Z.; Streets, D. G.; Zhang, Q.; Wang, S.; Carmichael, G. R.; Cheng, Y. F.; Wei, C.; Chin, M.; Diehl, T.; Tan, Q.; Decision and Information Sciences; Tsinghua Univ.; Univ. of Iowa; NASA Goddard Space Flight Center

2010-01-01

106

Sulfur dioxide emissions in China and sulfur trends in East Asia since 2000  

NASA Astrophysics Data System (ADS)

With the rapid development of the economy, the sulfur dioxide (SO2) emission from China since 2000 is of increasing concern. In this study, we estimate the annual SO2 emission in China after 2000 using a technology-based methodology specifically for China. From 2000 to 2006, total SO2 emission in China increased by 53%, from 21.7 Tg to 33.2 Tg, at an annual growth rate of 7.3%. Emissions from power plants are the main sources of SO2 in China and they increased from 10.6 Tg to 18.6 Tg in the same period. Geographically, emission from north China increased by 85%, whereas that from the south increased by only 28%. The emission growth rate slowed around 2005, and emissions began to decrease after 2006 mainly due to the wide application of Flue-Gas Desulfurization (FGD) devices in power plants in response to a new policy of China's government. This paper shows that the trend of estimated SO2 emission in China is consistent with the trends of SO2 concentration and acid rain pH and frequency in China, as well as with the increasing trends of background SO2 and sulfate concentration in East Asia. A longitudinal gradient in the percentage change of urban SO2 concentration in Japan is found during 2000-2007, indicating that the decrease of urban SO2 is lower in areas close to the Asian continent. This implies that the transport of increasing SO2 from the Asian continent partially counteracts the local reduction of SO2 emission downwind. The Aerosol Optical Depth (AOD) products of Moderate Resolution Imaging Spectroradiometer (MODIS) are found to be highly correlated with the Surface Solar Radiation (SSR) measurements in East Asia. Using MODIS AOD data as a surrogate of SSR, we found that China and East Asia excluding Japan underwent a continuous dimming after 2000, which is in line with the dramatic increase in SO2 emission in East Asia. The trends of AOD from both satellite retrievals and model over East Asia are also consistent with the trend of SO2 emission in China, especially during the second half of the year, when sulfur contributes the largest fraction of AOD. The arrested growth in SO2 emissions since 2006 is also reflected in the decreasing trends of SO2 and SO42- concentrations, acid rain pH values and frequencies, and AOD over East Asia.

Lu, Z.; Streets, D. G.; Zhang, Q.; Wang, S.; Carmichael, G. R.; Cheng, Y. F.; Wei, C.; Chin, M.; Diehl, T.; Tan, Q.

2010-04-01

107

Sulfur dioxide emissions in China and sulfur trends in East Asia since 2000  

NASA Astrophysics Data System (ADS)

With the rapid development of the economy, the sulfur dioxide (SO2) emission from China since 2000 is of increasing concern. In this study, we estimate the annual SO2 emission in China after 2000 using a technology-based methodology specifically for China. From 2000 to 2006, total SO2 emission in China increased by 53%, from 21.7 Tg to 33.2 Tg, at an annual growth rate of 7.3%. Emissions from power plants are the main sources of SO2 in China and they increased from 10.6 Tg to 18.6 Tg in the same period. Geographically, emission from north China increased by 85%, whereas that from the south increased by only 28%. The emission growth rate slowed around 2005, and emissions began to decrease after 2006 mainly due to the wide application of flue-gas desulfurization (FGD) devices in power plants in response to a new policy of China's government. This paper shows that the trend of estimated SO2 emission in China is consistent with the trends of SO2 concentration and acid rain pH and frequency in China, as well as with the increasing trends of background SO2 and sulfate concentration in East Asia. A longitudinal gradient in the percentage change of urban SO2 concentration in Japan is found during 2000-2007, indicating that the decrease of urban SO2 is lower in areas close to the Asian continent. This implies that the transport of increasing SO2 from the Asian continent partially counteracts the local reduction of SO2 emission downwind. The aerosol optical depth (AOD) products of Moderate Resolution Imaging Spectroradiometer (MODIS) are found to be highly correlated with the surface solar radiation (SSR) measurements in East Asia. Using MODIS AOD data as a surrogate of SSR, we found that China and East Asia excluding Japan underwent a continuous dimming after 2000, which is in line with the dramatic increase in SO2 emission in East Asia. The trends of AOD from both satellite retrievals and model over East Asia are also consistent with the trend of SO2 emission in China, especially during the second half of the year, when sulfur contributes the largest fraction of AOD. The arrested growth in SO2 emissions since 2006 is also reflected in the decreasing trends of SO2 and SO42- concentrations, acid rain pH values and frequencies, and AOD over East Asia.

Lu, Z.; Streets, D. G.; Zhang, Q.; Wang, S.; Carmichael, G. R.; Cheng, Y. F.; Wei, C.; Chin, M.; Diehl, T.; Tan, Q.

2010-07-01

108

Sighting of el chichon sulfur dioxide clouds with the nimbus 7 total ozone mapping spectrometer.  

PubMed

The eruptions of El Chichón volcano on 28 March and 3 and 4 April 1982 were observed by the Nimbus 7 total ozone mapping spectrometer due to strong absorption by volcanic gases at the shortest wavelengths of the spectrometer (312.5 and 317.5 nanometers). These ultraviolet pictures permit a measurement of the volume, dispersion, and drift of volcanic gas clouds. The tropospheric clouds were rapidly dispersed in westerly winds while persistent stratospheric clouds drifted in easterly winds at speeds up to 13 meters per second. The spectral reflectance is consistent with sulfur dioxide absorption and rules out carbon disulfide as a major constituent. A preliminary estimate of the mass of sulfur dioxide deposited in the stratosphere by the large eruptions on 3 and 4 April is 3.3 x 10(6) tons. Prior estimates of volcanic cloud volume were based on extrapolation of locally measured sulfur dioxide concentrations. PMID:17730652

Krueger, A J

1983-06-24

109

Modelling and Remote Sensing of Ash and Sulfur Dioxide from the 2008 Kasatochi Volcano Eruption  

NASA Astrophysics Data System (ADS)

We simulated the formation, evolution and transport of volcanic ash and sulfur dioxide (SO2) from the 2008 eruption of Kasatochi volcano using the Weather Research Forecasting (WRF) with inline Chemistry (WRF-Chem). The volcano is located at the western Aleutian arc, and the ash and SO2 plume dispersed well over the North American continent. Using the Regional Acid Deposition Model, version 2 (RADM2) within WRF-Chem, we describe the conversion of sulfur dioxide to sulfate aerosols. WRF-Chem was further set up to use the GOCART aerosol module for predicting the fate of the sulfate aerosol downwind from the volcano. We validated model output with temporal and spatial comparisons to data available from various satellite borne sensors, including OMI, AIRS and MODIS. Temporal and special agreement between WRF and sensor data is discussed and the feasibility of using WRF-Chem as a tool for volcanic sulfur dioxide and ash prediction is assessed.

Egan, S.; Stuefer, M.

2013-12-01

110

Testing of an improved lithium-sulfur dioxide battery for aircrew life support equipment  

NASA Astrophysics Data System (ADS)

This report presents the results of in-house testing of lithium-sulfur dioxide cells. The report includes performance testing of an engineering prototype design of lithium-sulfur dioxide cells and the performance characterization, storage evaluations and abuse test behavior of the pilot production cell design. Several design modifications occurred during the development of this lithium-sulfur dioxide cell technology which significantly changed their performance. Testing of the pilot production cells included: (1) Performance evaluations at rates of 50MA, 100MA, 200MA, and 400 MA at temperatures from -65 F to +140 F; (2) Room temperature discharge tests at high rates of current; (3) Capacity retention capability as a function of storage time at temperatures of 32 F, 70 F and 160 F; (4) Evaluation of intermittent storage capability at 205 F; and (5) Abuse testing. Abuse testing included short circuit, nail penetration, and forced overdischarge conditions.

Cloyd, J. S.

1982-05-01

111

Fast-regenerable sulfur dioxide adsorbents for diesel engine emission control  

SciTech Connect

Disclosed herein are sorbents and devices for controlling sulfur oxides emissions as well as systems including such sorbents and devices. Also disclosed are methods for making and using the disclosed sorbents, devices and systems. In one embodiment the disclosed sorbents can be conveniently regenerated, such as under normal exhaust stream from a combustion engine, particularly a diesel engine. Accordingly, also disclosed are combustion vehicles equipped with sulfur dioxide emission control devices.

Li, Liyu [Richland, WA; King, David L [Richland, WA

2011-03-15

112

Improved efficiency in the sulfur dioxide - Iodine hydrogen cycle through the use of magnesium oxide  

NASA Astrophysics Data System (ADS)

The reaction of iodine with dry magnesium oxide and magnesium sulfite hexahydrate was studied experimentally as a possible means of improving the efficiency of the sulfur dioxide-iodine cycle. When no extra water was introduced, the maximum product yield was 67% obtained at 423 K. With excess water vapor, a nonporous plug was formed which prevented complete reaction. In the second case, maximum yield was 62% measured at 423 K showing that added water does not increase reaction products. This reaction gives an alternate route for producing hydrogen from water via the sulfur dioxide-iodine process.

Mason, C. F. V.; Bowman, M. G.

113

Ion-molecule reactions of O,S-dimethyl methylphosphonothioate: evidence for intramolecular sulfur oxidation during VX perhydrolysis.  

PubMed

The alkaline perhydrolysis of the nerve agent O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate (VX) was investigated by studying the ion-molecule reactions of HOO(-) with O,S-dimethyl methylphosphonothioate in a modified linear ion-trap mass spectrometer. In addition to simple proton transfer, two other abundant product ions are observed at m/z 125 and 109 corresponding to the S-methyl methylphosphonothioate and methyl methylphosphonate anions, respectively. The structure of these product ions is demonstrated by a combination of collision-induced dissociation and isotope-labeling experiments that also provide evidence for their formation by nucleophilic reaction pathways, namely, (i) S(N)2 at carbon to yield the S-methyl methylphosphonothioate anion and (ii) nucleophilic addition at phosphorus affording a reactive pentavalent intermediate that readily undergoes internal sulfur oxidation and concomitant elimination of CH(3)SOH to yield the methyl methylphosphonate anion. Consistent with previous solution phase observations of VX perhydrolysis, the toxic P-O cleavage product is not observed in this VX model system and theoretical calculations identify P-O cleavage to be energetically uncompetitive. Conversely, intramolecular sulfur oxidation is calculated to be extremely exothermic and kinetically accessible explaining its competitiveness with the facile gas phase proton transfer process. Elimination of a sulfur moiety deactivates the nerve agent VX and thus the intramolecular sulfur oxidation process reported here is also able to explain the selective perhydrolysis of the nerve agent to relatively nontoxic products. PMID:19919083

McAnoy, Andrew M; Williams, Jilliarne; Paine, Martin R L; Rogers, Michael L; Blanksby, Stephen J

2009-12-18

114

Statistical summary of air quality data for metropolitian Cleveland, Ohio, 1967 - 1972: Total suspended particulates, nitrogen dioxide, and sulfur dioxide  

NASA Technical Reports Server (NTRS)

Air-quality data for metropolitan Cleveland, Ohio, from 1967 through 1972 were collated and statistically analyzed. Total suspended particulates (TSP) departed from lognormal distribution in 1972. Nitrogen dioxide and sulfur dioxide, departed significantly from lognormal distributions in 1972. In Cleveland the Ohio standards were not met. However, the data indicate a general improvement in air quality. Unusually high precipitation (43% above the average in 1972) may be responsible in lowering these values from the 1971 levels. The mean values of TSP, NO2, and SO2 are 104, 191, and 83 microgram/cu m respectively.

King, R. B.; Neustadter, H. E.; Fordyce, J. S.; Burr, J. C., Jr.; Cornett, C. L.

1974-01-01

115

40 CFR 721.9672 - Amides, tall-oil fatty, N-[2-[2-hydroxyethyl)amino]ethyl], reaction products with sulfur dioxide...  

Code of Federal Regulations, 2010 CFR

...2-hydroxyethyl)amino]ethyl], reaction...sulfur dioxide; fatty acids, tall-oil, reaction...2-hydroxyethyl)amino]ethyl], reaction...sulfur dioxide; fatty acids, tall-oil, reaction...2-hydroxyethyl)amino]ethyl], reaction...sulfur dioxide; fatty acids, tall-oil,...

2010-07-01

116

40 CFR 721.9672 - Amides, tall-oil fatty, N-[2-[2-hydroxyethyl)amino]ethyl], reaction products with sulfur dioxide...  

Code of Federal Regulations, 2014 CFR

...2-hydroxyethyl)amino]ethyl], reaction...sulfur dioxide; fatty acids, tall-oil, reaction...2-hydroxyethyl)amino]ethyl], reaction...sulfur dioxide; fatty acids, tall-oil, reaction...2-hydroxyethyl)amino]ethyl], reaction...sulfur dioxide; fatty acids, tall-oil,...

2014-07-01

117

40 CFR 721.9672 - Amides, tall-oil fatty, N-[2-[2-hydroxyethyl)amino]ethyl], reaction products with sulfur dioxide...  

Code of Federal Regulations, 2011 CFR

...2-hydroxyethyl)amino]ethyl], reaction...sulfur dioxide; fatty acids, tall-oil, reaction...2-hydroxyethyl)amino]ethyl], reaction...sulfur dioxide; fatty acids, tall-oil, reaction...2-hydroxyethyl)amino]ethyl], reaction...sulfur dioxide; fatty acids, tall-oil,...

2011-07-01

118

40 CFR 721.9672 - Amides, tall-oil fatty, N-[2-[2-hydroxyethyl)amino]ethyl], reaction products with sulfur dioxide...  

Code of Federal Regulations, 2013 CFR

...2-hydroxyethyl)amino]ethyl], reaction...sulfur dioxide; fatty acids, tall-oil, reaction...2-hydroxyethyl)amino]ethyl], reaction...sulfur dioxide; fatty acids, tall-oil, reaction...2-hydroxyethyl)amino]ethyl], reaction...sulfur dioxide; fatty acids, tall-oil,...

2013-07-01

119

40 CFR 721.9672 - Amides, tall-oil fatty, N-[2-[2-hydroxyethyl)amino]ethyl], reaction products with sulfur dioxide...  

Code of Federal Regulations, 2012 CFR

...2-hydroxyethyl)amino]ethyl], reaction...sulfur dioxide; fatty acids, tall-oil, reaction...2-hydroxyethyl)amino]ethyl], reaction...sulfur dioxide; fatty acids, tall-oil, reaction...2-hydroxyethyl)amino]ethyl], reaction...sulfur dioxide; fatty acids, tall-oil,...

2012-07-01

120

Advanced product recovery: Direct catalytic reduction of sulfur dioxide to elemental sulfur. Third quarterly technical progress report  

SciTech Connect

More than 170 wet scrubber systems applied to 72,000 MW of US, coal-fired, utility boilers are in operation or under construction. In these systems, the sulfur dioxide removed form the boiler flue gas is permanently bound to a sorbent material, such as lime or limestone. The sulfated sorbent must be disposed of as a waste product or, in some cases, sold as a byproduct (e.g. gypsum). The use of regenerable sorbent technologies has the potential to reduce or eliminate solid waste production, transportation and disposal. Arthur D. Little, Inc., together with its industry and commercialization advisor, Engelhard Corporation, and its university partner, Tufts, plans to develop and scale-up an advanced, byproduct recovery technology that is a direct, catalytic process for reducing sulfur dioxide to elemental sulfur. The principal objective of the Phase 1 program is to identify and evaluate the performance of a catalyst which is robust and flexible with regard to choice of reducing gas. In order to achieve this goal, they have planned a structured program including: market/process/cost/evaluation; lab-scale catalyst preparation/optimization studies; lab-scale, bulk/supported catalyst kinetic studies; bench-scale catalyst/process studies; and utility review. This catalytic process reduces SO{sub 2} over a fluorite-type oxide (such as ceria and zirconia). The catalytic activity can be significantly promoted by active transition metals, such as copper. This type of mixed metal oxide catalyst has stable activity, high selectivity for sulfur production, and is resistant to water and carbon dioxide poisoning.

NONE

1996-07-01

121

Smart battery controller for lithium\\/sulfur dioxide batteries. Technical report, Jan 89Apr 91  

Microsoft Academic Search

Each year, the U.S. Army purchases millions of lithium sulfur dioxide batteries for use in portable electronics equipment. Because of their superior rate capability and service life over a wide variety of conditions, lithium batteries are the power source of choice for military equipment. There is no convenient method of determining the available energy remaining in partially used lithium batteries;

T. Atwater; A. Bard; B. Testa; W. Shader

1992-01-01

122

SPONTANEOUSLY HYPERTENSIVE RATS ARE SUSCEPTIBLE TO AIRWAY DISEASE INDUCED BY SULFUR DIOXIDE  

EPA Science Inventory

Rodent models of chronic pulmonary diseases induced by sulfur dioxide (SO2), elastase or tobacco smoke have limited utility because of their lack of chronicity of inflammation, and they demonstrate limited sensitivity to a given experimental manipulation. We hypothesized that dis...

123

DEVELOPMENT OF FEDERAL AIR STANDARDS TO REDUCE SULFUR DIOXIDE EMISSIONS FROM NEW INDUSTRIAL BOILERS. (JOURNAL VERSION)  

EPA Science Inventory

The paper gives EPA's conclusions from analyses which led to the decision to propose percent reduction Federal new source performance standards (NSPS) to control air emissions of sulfur dioxide (SO2) from new industrial boilers. It summarizes the NSPS. The NSPS would require boil...

124

REGIONAL TRENDS IN RURAL SULFUR DIOXIDE CONCENTRATIONS OVER THE EASTERN U.S.  

EPA Science Inventory

Emission reductions were mandated in the Clean Air Art Amendments of 1990 with the expectation that they would result in corresponding reductions in air pollution. The 1990 amendments include new requirements that appreciably reduced sulfur dioxide (SO2) emissions in two phases o...

125

OXYGEN ISOTOPES IN ATMOSPHERIC SULFATES, SULFUR DIOXIDE, AND WATER VAPORS FIELD MEASUREMENTS, JULY 1975  

EPA Science Inventory

Oxygen isotope ratios were determined for atmospheric samples of sulfate aerosols, sulfur dioxide, and water vapor collected simultaneously during a six-day period in July, 1975, at St. Louis, MO; Auburn, IL; and Glasgow, IL. The collection sites were located about 100km apart. C...

126

PHYSIOLOGY OF ECOTYPIC PLANT RESPONSE TO SULFUR DIOXIDE IN 'GERANIUM CAROLINIANUM' L  

EPA Science Inventory

Populations of Geranium carolinianum, winter annual plant common in disturbed habitats vary in their folair response to sulfur dioxide and pollution resistance is characteristic of populations sampled from areas in which SO2 has been a prominent stress. The physiological basis of...

127

DISPERSION OF SULFUR DIOXIDE FROM THE CLINCH RIVER POWER PLANT, A WIND-TUNNEL STUDY  

EPA Science Inventory

A wind-tunnel study of the transport and dispersion of sulfur dioxide from the Clinch River Power Plant in Virginia was performed for periods of neutral atmospheric conditions corresponding to two 1-hour periods for which field data were available. A 7-km x 21-km area of the quit...

128

PORE DISTRIBUTION CHANGES OF CALCIUM-BASED SORBENTS REACTING WITH SULFUR DIOXIDE  

EPA Science Inventory

The paper gives results of a determination of changes in the pore structure of calcium oxide sorbents derived from calcium carbonate (termed c-CaO) and calcium hydroxide (termed h-CaO) reacting with sulfur dioxide (SO2). Results show that the pore shape of c-CaO approximates a cy...

129

The Sulfur Dioxide Plume from the February 26, 2000 Eruption of Mt. Hekla, Iceland  

NASA Technical Reports Server (NTRS)

The February 2000 fissure eruption of Mt. Hekla, Iceland was captured in sulfur dioxide data from the Earth Probe TOMS. A special algorithm is used to discriminate sulfur dioxide from ozone. The eruption began at 18:19 GMT on February 26, 2000 and was first viewed by TOMS at 09:55 GMT on February 27. The volcanic cloud at that time appeared as a very long and narrow arc extending west from the volcano in southern Iceland, then north across Greenland, and finally east towards Norway. The cloud altitude was reported from aircraft sightings and data to be above 10 km. The circulation of a ridge located north of Iceland produced the large arc shaped cloud. As the eruption is non-explosive the high altitude cloud contains little ash. Almost all the ash from the eruption fell out locally across Iceland. By February 29, the sulfur dioxide cloud had drifted eastward in a band along the Barents Sea coast of Norway and Russia. The analysis includes an assessment of the initial sulfur dioxide content and its rate of conversion to sulfate.

Krueger, Arlin J.; Krotkov, N. A.; Einaudi, Franco (Technical Monitor)

2000-01-01

130

COST COMPARISONS OF SELECTED TECHNOLOGIES FOR THE CONTROL OF SULFUR DIOXIDE FROM COPPER SMELTERS  

EPA Science Inventory

The U.S. nonferrous metals production industry is a significant contributor of sulfur dioxide, trace metal, and particulate air emissions. Most of the domestic copper smelting capacity is based on obsolescent technology that is both capital-and energy-intensive and hampered by co...

131

ACID PRECIPITATION: EFFECTS OF SULFUR DIOXIDE AND SULFATE AEROSOL PARTICLES ON HUMAN HEALTH  

EPA Science Inventory

While human health impairment has been attributed to pollution by sulfur dioxide (SO2), data from inhalation studies in animals show that its oxidation products are more irritating. Population surveys in which suspended sulfate was a co-variant suggest that certain health paramet...

132

Dynamics of sulfur dioxide absorption in a raindrop falling at terminal velocity  

Microsoft Academic Search

Sulfur dioxide absorption dynamics in a raindrop are studied numerically by means of a fully numerical simulation method (FNSM) in which a composite orthogonal grid system consisting of both gas- and liquid-phase is adopted. When a raindrop with fixed radius falls in association with terminal velocity, a recirculation bubble always accompanies the gas-phase flow field in the aft region of

Wei-Hsin Chen

2001-01-01

133

Mortality from Lung Cancer in Workers Exposed to Sulfur Dioxide in the Pulp and Paper Industry  

Microsoft Academic Search

Our objective in this study was to evaluate the mortality of workers exposed to sulfur dioxide in the pulp and paper industry. The cohort included 57,613 workers employed for at least 1 year in the pulp and paper industry in 12 countries. We assessed exposure to SO2 at the level of mill and department, using industrial hygiene measurement data and

Won Jin Lee; Kay Teschke; Timo Kauppinen; Aage Andersen; Paavo Jäppinen; Irena Szadkowska-Stanczyk; Neil Pearce; Bodil Persson; Alain Bergeret; Luiz Augusto Facchini; Reiko Kishi; Danuta Kielkowski; Bo Andreassen Rix; Paul Henneberger; Jordi Sunyer; Didier Colin; Manolis Kogevinas; Paolo Boffetta

2002-01-01

134

ENHANCEMENT OF REACTIVITY IN SURFACTANT-MODIFIED SORBENTS FOR SULFUR DIOXIDE CONTROL  

EPA Science Inventory

Injection of calcium-based sorbents into the postflame zone of utility boilers is capable of achieving sulfur dioxide (SO2) captures of 50-60% at a stoichiometry of 2. Calcium hydroxide [Ca(OH)2] appears to be the most effective commercially available sorbent. Recent attempts to ...

135

CALCINATION AND SINTERING OF SORBENTS DURING BOILER INJECTION FOR DRY SULFUR DIOXIDE CONTROL  

EPA Science Inventory

The paper discusses the calcination and sintering of sorbents during boiler injection for dry sulfur dioxide (S02) control, with emphasis on calcium hydroxide--Ca(OH)2--because of its superior reactivity with S02 and its wide commercial availability. Calcination and sintering are...

136

Sulfur dioxide oxidation and plume formation at cement kilns  

SciTech Connect

Results of source sampling at the Glens Falls cement kiln in Glens Falls, N.Y., are reported for sulfur oxides, ammonia, hydrochloric acid, oxygen, and moisture content. The origin of a detached, high-opacity, persistent plume originating from the cement kiln stack is investigated. It is proposed that this plume is due to ammonium salts of SOx and sulfuric acid that have been formed in condensed water droplets in the plume by the pseudocatalytic action of ammonia. (1 diagram, 1 graph, 22 references, 7 tables)

Dellinger, B.; Grotecloss, G.; Fortune, C.R.; Cheney, J.L.; Homolya, J.B.

1980-10-01

137

Laboratory Measurements of the Millimeter-Wavelength Sulfur Dioxide Absorption Spectrum under Simulated Venus Conditions  

NASA Astrophysics Data System (ADS)

Over 130 laboratory measurements of the 2-4 millimeter wavelength opacity of sulfur dioxide in a carbon dioxide atmosphere under simulated conditions for the upper Venus troposphere (temperatures between 308-343 K and pressures between 0.03- 2 bar) have been made. These measurements along with the centimeter wavelength measurements by Steffes et al. (Icarus, 2014, in press) have been used to empirically assess existing formalisms for sulfur dioxide opacity in a carbon dioxide atmosphere (Fahd and Steffes Icarus 97, 1992 and Suleiman et al. JGR 101, E2 1996). The Van Vleck and Weisskopf Model (VVW) used by Fahd and Steffes with the JPL rotational line catalog (Pickett, et al. JQSRT 60, 1998) was found to fit 85.88% of all 500 measurements within the 2-sigma uncertainty. This model was implemented in the new Georgia Tech Venus Radiative Transfer Model (GT-VRTM) which is capable of computing both disk-averaged and localized brightness temperatures of Venus. These are compared to observations. This work will improve retrievals of the atmospheric abundance of sulfur dioxide from observations of the Venus atmosphere. This work was supported by the NASA Planetary Atmospheres Program under Grant NNX11AD66G.

Bellotti, Amadeo; Steffes, Paul G.

2014-11-01

138

The creation of pollution mapping and measurement of ambient concentration of sulfur dioxide and nitrogen dioxide with passive sampler  

PubMed Central

Background Measurements of nitrogen and sulfur dioxide using passive sampler over 12 months in Samsun, Turkey, are compared with SO2 and NO2 concentrations obtained from a co-located chemiluminescence analyzer. The concentrations of Sulfur and nitrogen dioxide in the ambient air during the period from November 2009 to September 2010 are analyzed. Results The highest value for annual NO2 and SO2 averages of passive sampler was 29.65 ?g/m3 and 21.01 ?g/m3 for exposures of 2-weeks at an industrial site. The maximum monthly concentration for SO2 was observed at the 10th measurement station with 44.19 ?g/m3 for August. The maximum monthly concentration for NO2 was observed on the 3rd measurement station with 42.83 ?g/m3 for November. A negative correlation between nitrogen dioxide concentrations and temperature (R2?=??0.5489) was estimated. A positive correlation between nitrogen dioxide measurement with passive sampler and continuous measurement (R2?=?0.6571) was estimated. PMID:25136451

2014-01-01

139

THE CARBON DIOXIDE LEAKAGE FROM CHAMBERS MEASURED USING SULFUR HEXAFLUORIDE  

EPA Science Inventory

In plant chamber studies, if Co2 leaking from a chamber is not quantified, it can lead to an overestimate of assimilation rates and an underestimate of respiration rates: consequently, it is critical that Co2 leakage be determined. Sulfur Hexafluoride (SF6) was introduced into t...

140

40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).  

Code of Federal Regulations, 2013 CFR

...remove sulfur oxides. (iii) Fossil fuel means natural gas, refinery...from such materials. (iv) Fossil fuel-fired steam generating unit...used in the process of burning fossil fuel for the purpose of producing...

2013-07-01

141

40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).  

Code of Federal Regulations, 2010 CFR

...remove sulfur oxides. (iii) Fossil fuel means natural gas, refinery...from such materials. (iv) Fossil fuel-fired steam generating unit...used in the process of burning fossil fuel for the purpose of producing...

2010-07-01

142

40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).  

Code of Federal Regulations, 2012 CFR

...remove sulfur oxides. (iii) Fossil fuel means natural gas, refinery...from such materials. (iv) Fossil fuel-fired steam generating unit...used in the process of burning fossil fuel for the purpose of producing...

2012-07-01

143

40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).  

Code of Federal Regulations, 2011 CFR

...remove sulfur oxides. (iii) Fossil fuel means natural gas, refinery...from such materials. (iv) Fossil fuel-fired steam generating unit...used in the process of burning fossil fuel for the purpose of producing...

2011-07-01

144

40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).  

Code of Federal Regulations, 2014 CFR

...remove sulfur oxides. (iii) Fossil fuel means natural gas, refinery...from such materials. (iv) Fossil fuel-fired steam generating unit...used in the process of burning fossil fuel for the purpose of producing...

2014-07-01

145

Nitrogen dioxide, sulfur dioxide, and ammonia detector for remote sensing of vehicle emissions  

E-print Network

November 2005; published online 18 January 2006 A remote sensor for measuring on-road vehicles passing the U.S. is reducing sulfur in fuel and thus mobile source SO2 emissions, off-road fuel generally con- tains more sulfur and worldwide some fuels contain more than 600 times the U.S. limit.13 Off-road, high

Denver, University of

146

Impact of sulfur dioxide oxidation by Stabilized Criegee Intermediate on sulfate  

NASA Astrophysics Data System (ADS)

We revise the Carbon Bond chemical mechanism to explicitly represent three Stabilized Criegee Intermediates (SCIs) and their subsequent reactions with sulfur dioxide, water monomer, and water dimer, and incorporate the reactions into the Community Multiscale Air Quality model. The reaction of sulfur dioxide with SCI produces sulfuric acid which partitions into sulfate. We examine the impact of sulfur dioxide oxidation by SCI on sulfate using two different measured rate constants for the reaction of sulfur dioxide and SCI. When we use the higher rate constant and emissions estimates from the Biogenic Emissions Inventory System, it enhances monthly mean sulfate in summer by ?20% in biogenically active areas. Enhancements are driven primarily by SCI produced from the reactions of biogenically derived alkenes and ozone. The use of the lower rate constant only marginally enhances sulfate since it is 65 times lower than the higher rate constant. We performed several sensitivity analyses to investigate the impacts of uncertain biogenic emissions and SCI loss rates. When we use the higher rate constant and emissions estimates from the Model of Emissions of Gases and Aerosols from Nature, it enhances monthly mean sulfate by ?75%. A simulation using the lowest reported rate constant for the reaction of SCI and water indicated the maximum enhancement of sulfate from this chemistry was up to 4 ?g/m3 over a 24-h period in some locations in the Southeastern U.S. Predictions without the SCI reaction are lower than observed sulfate while predictions with the SCI reaction improve the agreements with observations.

Sarwar, Golam; Simon, Heather; Fahey, Kathleen; Mathur, Rohit; Goliff, Wendy S.; Stockwell, William R.

2014-03-01

147

Sulfuric Acid Nucleation with NH3, Methyl, Dimethyl, and Trimethyl Amines  

NASA Astrophysics Data System (ADS)

Nucleation of particles from sulfuric acid, water, and nitrogen base molecules was studied within a cylindrical flow reactor. The particles formed from these vapors were detected with a nano Mobility Particle Sizer coupled to a Diethylene Glycol Ultrafine Condensation Particle Counter. The effects of ammonia and small alkyl amines on particle formation with sulfuric acid vapor were very large. Enhancements of particle numbers by factors of thousands to millions indicates that these species have powerful effects on nucleation of sulfuric acid molecules. Power dependencies for particle numbers on sulfuric acid and nitrogen bases elucidates the chemical content of the critical clusters and this helps to shed light on the nucleation mechanisms. The details of the particle detection efficiencies, information on the extent of particle growth, and independently determined cluster thermodynamics help to verify these results and to extrapolate them to atmospheric conditions.

Hanson, D. R.; Volz, K.; Glasoe, W.; Panta, B.

2013-12-01

148

EFFECT OF SULFUR DIOXIDE ON THE FORMATION MECHANISM OF POLYCHLORINATED DIBENZODIOXIN AND DIBENZOFURAN IN MUNICIPAL WASTE COMBUSTORS  

EPA Science Inventory

The effect of sulfur dioxide on the formation mechanism of polychlorinated dibenzodioxin (PCDD) and polychlorinated dibenzofuran (PCDF) in the postcombustion, downstream region (500-300 °C) of a municipal waste combustor (MWC) was investigated. Laboratory experiments simulating t...

149

CONTROL OF AIR POLLUTION EMISSIONS FROM MOLYBDENUM ROASTING. VOLUME 2. ALTERNATIVES FOR CONTROL OF WEAK SULFUR DIOXIDE EMISSIONS  

EPA Science Inventory

This report covers the second phase of a three phase effort evaluating (1) characterization of particulate control of a molybdenum sulfide roasters, (2) assessment of sulfur dioxide abatement alternatives for nonferrous smelting and, in particular, for molybdenum roasting, and (3...

150

Sulfur dioxide emission rates from K?lauea Volcano, Hawai‘i, 2007–2010  

USGS Publications Warehouse

K?lauea Volcano has one of the longest running volcanic sulfur dioxide (SO2) emission rate databases on record. Sulfur dioxide emission rates from K?lauea Volcano were first measured by Stoiber and Malone (1975) and have been measured on a regular basis since 1979 (Elias and Sutton, 2007, and references within). Compilations of SO2 emission-rate and wind-vector data from 1979 through 2006 are available on the USGS Web site (Elias and others, 1998; Elias and Sutton, 2002; Elias and Sutton, 2007). This report updates the database, documents the changes in data collection and processing methods, and highlights how SO2 emissions have varied with eruptive activity at K?lauea Volcano for the interval 2007–2010.

Elias, T.; Sutton, A.J.

2012-01-01

151

Synthesis of cyclic sulfites from epoxides and sulfur dioxide with silica-immobilized homogeneous catalysts.  

PubMed

Quaternary ammonium- and amino-functionalized silica catalysts have been prepared for the selective synthesis of cyclic sulfites from epoxides and sulfur dioxide, demonstrating the effects of immobilizing the homogeneous catalysts on silica. The cycloaddition of sulfur dioxide to various epoxides was conducted under solvent-free conditions at 100 °C. The quaternary ammonium- and amino-functionalized silica catalysts produced cyclic sulfites in high yields (79-96 %) that are comparable to those produced by the homogeneous catalysts. The functionalized silica catalysts could be separated from the product solution by filtration, thereby avoiding the catalytic decomposition of the cyclic sulfite products upon distillation of the product solution. Heterogenization of a homogeneous catalyst by immobilization can, therefore, improve the efficiency of the purification of crude reaction products. Despite a decrease in catalytic activity after each recycling step, the heterogeneous pyridine-functionalized silica catalyst provided high yields after as many as five recycling processes. PMID:22135049

Takenaka, Yasumasa; Kiyosu, Takahiro; Mori, Goro; Choi, Jun-Chul; Fukaya, Norihisa; Sakakura, Toshiyasu; Yasuda, Hiroyuki

2012-01-01

152

Protective effects of seabuckthorn seed oil on mouse injury induced by sulfur dioxide inhalation.  

PubMed

Sulfur dioxide (SO2) is a common but important air pollutant. Micronuclei (MN) in the polychromatic erythrocytes (PCE) of mouse bone marrow and the ratio between organ and body weight of treatment mouse were determined and analyzed in vivo in order to study injury of sulfur dioxide inhalation on organs and germ plasm of mouse as well as protective effect of seabuckthorn seed oil against this injury. It was showed that SO2 inhalation induced the change of the ratio between organ and body of mouse organs, such as liver, lung, kidney, and spleen, and a significant increase of number of MNPCE, while seabuckthorn seed oil offered a protection against such injury. PMID:12928980

Ruan, Aidong; Min, Hang; Meng, Ziqiang; Lü, Zhenmei

2003-09-01

153

A Sulfur Dioxide Climate Feedback on Early Mars  

NASA Astrophysics Data System (ADS)

Reconciling evidence for persistent liquid water during the late Noachian with our understanding of the evolution of the Martian atmosphere and of solar luminosity remains a challenge, despite several decades of research. An optically-thicker atmosphere to supply the necessary radiative forcing would result in the existence of a carbon cycle similar to Earth's, where the release of CO2 from volcanoes is balanced by burial of calcium carbonate through silicate weathering reactions that remove protons and release alkalinity to surface waters. Existence of such a carbon cycle on Mars, even for tens of millions of years, would yield carbonate sediments in far greater abundance than has been observed, as well as residual clay minerals. The high concentration of sulfur in Martian soils and rocks indicates that Martian volcanic emissions contained abundant sulfur volatiles in addition to CO2. However, the atmospheric and aquatic chemistry of SO2 under the reducing conditions of early Mars, in contrast with the presently oxidizing and biologically-catalyzed Earth, has not been thoroughly examined. We argue that these conditions may have allowed atmospheric concentrations of SO2 high enough to augment a thick CO2-H2O greenhouse. Furthermore, early Martian climate may have been stabilized by a feedback mechanism involving SO2 and the solubility of sulfite minerals instead of CO2 and the solubility of carbonates. We present the results of a one-dimensional radiative-convective model, demonstrating the radiative importance of SO2 to the planetary energy budget. We also use a simple geochemical model to show that the presence of SO2 in the early Martian atmosphere would have dominated the aquatic chemistry on the planet's surface, and may provide an explanation for how water could have persisted for millions of years without forming massive carbonate sediments, yet allowing the formation of clay minerals.

Halevy, I.; Pierrehumbert, R. T.; Schrag, D. P.

2007-12-01

154

Ozone and sulfur dioxide effects on the ultrastructure of the chloroplasts of hybrid poplar leaves  

SciTech Connect

This report is concerned with the effects of ozone and sulfur dioxide, alone and in combination, on leaf chloroplasts of a deciduous woody plant. Populus deltoides represents one of the few deciduous plants to be studied for the effects of these two common air pollutants. This report details the results of these pollutants on hybrid poplar leaf mesophyll cells under similar experimental conditions as above, but processed for conventional transmission electron microscopy.

Pechak, D.G.; Noble, R.D.; Dochinger, L.

1986-03-01

155

Sulfur dioxide and primary carbonaceous aerosol emissions in China and India, 1996-2010  

Microsoft Academic Search

China and India are the two largest anthropogenic aerosol generating countries in the world. In this study, we develop a new inventory of sulfur dioxide (SO2) and primary carbonaceous aerosol (i.e., black and organic carbon, BC and OC) emissions from these two countries for the period 1996-2010, using a technology-based methodology. Emissions from major anthropogenic sources and open biomass burning

Z. Lu; Q. Zhang; D. G. Streets

2011-01-01

156

Catalytic conversion of aryl triazenes into aryl sulfonamides using sulfur dioxide as the sulfonyl source.  

PubMed

Various sulfonamides have been synthesized from triazenes and sulfur dioxide. In the presence of just a catalytic amount of BF3·OEt2, a series of 1-aryl-triazenes were converted into sulfonyl hydrazines in good to excellent yields. When using CuCl2 as the catalyst, the corresponding sulfonamides can be produced from the 1-aryl triazenes in good yields. PMID:25010993

Li, Wanfang; Beller, Matthias; Wu, Xiao-Feng

2014-08-28

157

Vertical distribution of dimethylsulfide, sulfur dioxide, aerosol ions, and radon over the Northeast Pacific Ocean  

Microsoft Academic Search

Dimethylsulfide (DMS), sulfur dioxide (SO2), methanesulfonate (MSA), nonsea-salt sulfate (nss-SO42-), sodium (Na+), ammonium (NH4+), and nitrate (NO3-) were determined in samples collected by aircraft over the open ocean in postfrontal maritime air masses off the northwest coast of the United States (3–12 May 1985). Measurements of radon daughter concentrations and isentropic trajectory calculations suggested that these air masses had been

M. O. Andreae; H. Berresheim; T. W. Andreae; M. A. Kritz; T. S. Bates; J. T. Merrill

1988-01-01

158

Effects of ozone and sulfur dioxide on tuber yield and quality of potatoes  

Microsoft Academic Search

Air pollution injury of the potato plant (Solanum tuberosum L.) has been documented previously, but potato yield losses have not been estimated in replicated experiments having controlled exposures to ozone (Oā) and sulfur dioxide (SOā). A controlled-environment study involving the speckle-leaf-sensitive cultivar 'Centennial Russet' was conducted to examine the effects of chronic exposure to Oā and SOā on plant growth

K. W. Foster; H. Timm; C. K. Labanauskas; R. J. Oshima

1983-01-01

159

Temperature and pressure dependence of the electrooptical Kerr effect of sulfur dioxide  

Microsoft Academic Search

Measurements of the electrooptical Kerr effect of sulfur dioxide over a range of temperature (ā 299-490 K) and pressure (ā45-200 kPa) are reported. Analysis of the temperature dependence of the first Kerr virial coefficient in conjunction with the known mean polarizability and Rayleigh depolarization ratio yields high-precision values of the optical-frequency polarizabilities of the molecule. Results (10ā“Ā°Ī±{sub xx}\\/C mĀ² Vā»Ā¹,

Ian R. Gentle; Derek R. Laver; L. D. Ritchie

1990-01-01

160

Effects of sulfur dioxide on resistance to bacterial infection in mice  

SciTech Connect

Continuous exposure to approximately a 10-ppm concentration of sulfur dioxide for periods of up to 3 weeks reduced the resistance of female mice to infection by aerosol inoculation with Klebsiella pneumoniae. The mortality rate rose and survival time shortened in SO/sub 2/-exposed animals compared to controls. Insofar as these results can be extrapolated to humans, the SO/sub 2/ concentration used in this work is only found on certain industrial premises.

Azoulay-Dupuis, E. (Hopital Claude Bernard, Paris, France); Bouley, G.; Blayo, M.C.

1982-12-01

161

Measurement of Indoor Sulfur Dioxide Emission from Coal–Biomass Briquettes  

Microsoft Academic Search

The coal–biomass briquette is an alternative fuel that replaces low-grade coal. It is expected that the use of coal–biomass briquettes will effectively reduce the indoor concentration of sulfur dioxide (SO2) emitted during raw coal combustion. In this study, indoor concentrations of SO2 emitted from combustion of either coal–biomass briquettes or low-grade coal in households in Nanchuan, which is in the

Yugo Isobe; Kimiko Yamada; Qingyue Wang; Kazuhiko Sakamoto; Iwao Uchiyama; Tsuguo Mizoguchi; Yanrong Zhou

2005-01-01

162

Staying hydrated: the molecular journey of gaseous sulfur dioxide to a water surface.  

PubMed

A water surface is a dynamic and constantly evolving terrain producing a vast array of unique molecular properties and interactions with chemical species in the environment. The complex dynamics of water surfaces permit life on earth to continue, but also complicate the development of a complete microscopic picture of the specific behaviors that take place within interfacial aqueous environments. This computational study examines a piece of the water puzzle by elucidating the bonding, dynamic interactions, and hydrate structures of sulfur dioxide gas adsorbing to a water cluster. Results described herein address the specific ways in which sulfur dioxide gas molecules bind to a water cluster, and paint a more complete picture of the adsorption pathway than was previously developed from experimental and computational studies. Ab initio molecular dynamics have been employed to study sulfur dioxide and water interactions at two environmentally relevant temperatures on a water cluster. The results of this study on a common environmental and industrially important gas provide molecular insight to aid our understanding of interactions on aqueous surfaces, and gaseous adsorption processes. PMID:23549378

Shamay, Eric S; Valley, Nicholas A; Moore, Frederick G; Richmond, Geraldine L

2013-05-14

163

Selective catalytic reduction of sulfur dioxide to elemental sulfur. Final report  

SciTech Connect

This project has investigated new metal oxide catalysts for the single stage selective reduction of SO{sub 2} to elemental sulfur by a reductant, such as CO. Significant progress in catalyst development has been made during the course of the project. We have found that fluorite oxides, CeO{sub 2} and ZrO{sub 2}, and rare earth zirconates such as Gd{sub 2}Zr{sub 2}O{sub 7} are active and stable catalysts for reduction Of SO{sub 2} by CO. More than 95% sulfur yield was achieved at reaction temperatures about 450{degrees}C or higher with the feed gas of stoichiometric composition. Reaction of SO{sub 2} and CO over these catalysts demonstrated a strong correlation of catalytic activity with the catalyst oxygen mobility. Furthermore, the catalytic activity and resistance to H{sub 2}O and CO{sub 2} poisoning of these catalysts were significantly enhanced by adding small amounts of transition metals, such as Co, Ni, Co, etc. The resulting transition metal-fluorite oxide composite catalyst has superior activity and stability, and shows promise in long use for the development of a greatly simplified single-step sulfur recovery process to treat variable and dilute SO{sub 2} concentration gas streams. Among various active composite catalyst systems the Cu-CeO{sub 2} system has been extensively studied. XRD, XPS, and STEM analyses of the used Cu-CeO{sub 2} catalyst found that the fluorite crystal structure of ceria was stable at the present reaction conditions, small amounts of copper was dispersed and stabilized on the ceria matrix, and excess copper oxide particles formed copper sulfide crystals of little contribution to catalytic activity. A working catalyst consisted of partially sulfated cerium oxide surface and partially sulfided copper clusters. The overall reaction kinetics were approximately represented by a first order equation.

Liu, W.; Flytzani-Stephanopoulos, M.; Sarofim, A.F.

1995-06-01

164

Sulfur dioxide emissions and sectorial contributions to sulfur deposition in Asia  

NASA Astrophysics Data System (ADS)

Anthropogenic and volcanic emissions of SO 2 in Asia for 1987-1988 are estimated on a 1° × 1° grid. Anthropogenic sources are estimated to be 31.6 Tg of SO 2 with the regions' volcanoes emitting an additional 3.8 Tg. For Southeast Asia and the Indian sub-continent, the emissions are further partitioned into biomass, industrial, utilities, and non-specific sources. In these regions emissions from biomass, utilities and industrial sources account for 16.7, 21.7, and 12.2%, respectively. In Bangladesh, ˜ 90% of the SO 2 emissions result from biomass burning and nearly 20% of India's 5 Tg of SO 2 emissions are due to biomass burning. Malaysia and Singapore's emissions are dominated by the utilities with 42 and 62% of their respective emissions coming from that sector. The spatial distribution of sulfur deposition resulting from these emissions is calculated using an atmospheric transport and deposition model. Sulfur deposition in excess of 2 g m -2 yr -1 is predicted in vast regions of east Asia, India, Thailand, Malaysia, Taiwan, and Indonesia with deposition in excess of 5 g m -2 yr -1 predicted in southern China. For the Indian sub-continent and Southeast Asia the contribution of biomass burning, industrial activities, and utilities to total sulfur emissions and deposition patterns are evaluated. Biomass burning is found to be a major source of sulfur deposition throughout southeast Asia. Deposition in Bangladesh and northern India is dominated by this emissions sector. Deposition in Thailand, the Malay Peninsula and the island of Sumatra is heavily influenced by emissions from utilities. The ecological impact of the deposition, in 1988 and in the year 2020, is also estimated using critical loads data developed in the RAINS-ASIA projects. Much of eastern China, the Korean Peninsula, Japan, Thailand, and large regions of India, Nepal, Bangladesh, Taiwan, the Philippines, Malaysia, Indonesia, and sections of Vietnam are at risk due to deposition in excess of their critical loads if emission trends continue at the current rate.

Arndt, Richard L.; Carmichael, Gregory R.; Streets, David G.; Bhatti, Neeloo

165

Stomatal conductance and sulfur uptake of five clones of Populus tremuloides exposed to sulfur dioxide  

SciTech Connect

Plants of five clones of Populus tremuloides Michx. were exposed to 0, 0.2 or 0.5 microliter per liter SO/sub 2/ for 8 hours in controlled environment chambers. In the absence of the pollutant, two pollution-resistant clones maintained consistently lower daytime diffusive conductance (LDC) than did a highly susceptible clone or two moderately resistant clones. Rates of recovery following fumigation varied with the clone, but the LDC of all clones had returned to control values by the beginning of the night following fumigation. Fumigation for 16 hours (14 hours day + 2 hours night) with 0.4 microliter per liter SO/sub 2/ decreased night LDC by half. Sulfur uptake studies generally confirmed the results of the conductance measurements. The results show that stomatal conductance is important in determining relative susceptibility of the clones to pollution stress.

Kimmerer, T.W.; Kozlowski, T.T.

1981-05-01

166

[Effects of different processing methods on effective components and sulfur dioxide residue in Gastrodiae Rhizoma].  

PubMed

The contents of adenosine, gastrodin, 4-hydroxybenzyl alcohol, 4-hydroxybenzaldehyde, parishin and sulfur dioxide residue were compared in differently-processed Gastrodiae Rhizoma to provide the basis for a reasonable processing method of Gastrodiae Rhizoma. The analysis was performed on a Merck Purospher STAR column (4.6 mm x 250 mm, 5 ?m) with a mobile phase consisting of methanol and water (containing 0.1% formic acid) under gradient elution at a flow rate of 1.0 mL x min(-1). The eluates were detected at 270 nm, and the column temperature was 35°C. The content of adenosin, gastrodin, 4-hydroxybenzyl alcohol, 4-hydroxy-benzaldehyde and parishin in processing of boiling or sulfur-fumigated were lower than that of in processing of steaming. Furthermore, the sulfur dioxide residue of sulphur-fumigated groups exceed 400 mg x kg(-1). This stable and reliable method will contribute to the quality control of different processed Gastrodiae Rhizoma. PMID:25507536

Ning, Zi-Wan; Mao, Chun-Qin; Lu, Tu-Lin; Ji, De; Liu, Jing; Ji, Lin; Yang, Huan; Wang, Fa-Qin

2014-08-01

167

[Effects of different processing methods on effective components and sulfur dioxide residue in Gastrodiae Rhizoma].  

PubMed

The contents of adenosine, gastrodin, 4-hydroxybenzyl alcohol, 4-hydroxybenzaldehyde, parishin and sulfur dioxide residue were compared in differently-processed Gastrodiae Rhizoma to provide the basis for a reasonable processing method of Gastrodiae Rhizoma. The analysis was performed on a Merck Purospher STAR column (4.6 mm x 250 mm, 5 ?m) with a mobile phase consisting of methanol and water (containing 0.1% formic acid) under gradient elution at a flow rate of 1.0 mL x min(-1). The eluates were detected at 270 nm, and the column temperature was 35°C. The content of adenosin, gastrodin, 4-hydroxybenzyl alcohol, 4-hydroxy-benzaldehyde and parishin in processing of boiling or sulfur-fumigated were lower than that of in processing of steaming. Furthermore, the sulfur dioxide residue of sulphur-fumigated groups exceed 400 mg x kg(-1). This stable and reliable method will contribute to the quality control of different processed Gastrodiae Rhizoma. PMID:25423814

Ning, Zi-Wan; Mao, Chun-Qin; Lu, Tu-Lin; Ji, De; Liu, Jing; Ji, Lin; Yang, Huan; Wang, Fa-Qin

2014-08-01

168

Study of a QCM Dimethyl Methylphosphonate Sensor Based on a ZnO-Modified Nanowire-Structured Manganese Dioxide Film  

PubMed Central

Sensitive, selective and fast detection of chemical warfare agents is necessary for anti-terrorism purposes. In our search for functional materials sensitive to dimethyl methylphosphonate (DMMP), a simulant of sarin and other toxic organophosphorus compounds, we found that zinc oxide (ZnO) modification potentially enhances the absorption of DMMP on a manganese dioxide (MnO2) surface. The adsorption behavior of DMMP was evaluated through the detection of tiny organophosphonate compounds with quartz crystal microbalance (QCM) sensors coated with ZnO-modified MnO2 nanofibers and pure MnO2 nanofibers. Experimental results indicated that the QCM sensor coated with ZnO-modified nanostructured MnO2 film exhibited much higher sensitivity and better selectivity in comparison with the one coated with pure MnO2 nanofiber film. Therefore, the DMMP sensor developed with this composite nanostructured material should possess excellent selectivity and reasonable sensitivity towards the tiny gaseous DMMP species. PMID:22163653

Pei, Zhifu; Ma, Xingfa; Ding, Pengfei; Zhang, Wuming; Luo, Zhiyuan; Li, Guang

2010-01-01

169

Laboratory measurement of the dry deposition of sulfur dioxide onto northern Chinese soil samples  

NASA Astrophysics Data System (ADS)

We investigated soil surface resistance Rc to dry deposition of sulfur dioxide (SO 2) onto different types of soils in laboratory experiments, using samples collected from the arid loess plateau and deserts of northern China. We evaluated the factors that affect Rc, which depends on the physical and chemical interaction between a trace constituent and the deposition surface. We observed that the values of Rc for SO 2 decreased with increase of soil weight and increased with SO 2 concentration, although surface coverage had little effect on Rc. The SO 2 uptake rate by all the northern Chinese soil samples seemed to be, on the whole, dependent on relative humidity (RH). In all of the northern Chinese soil samples, Rc was in the range 0.028-0.65 s mm -1, and was exponentially related to the effective surface area of each soil sample, regardless of RH. Wet chemical analysis of sulfur deposited onto the soil samples showed that oxidation ratio of sulfur(IV) to sulfur(VI) was related to RH, which might be related to complex interactions among the amount of water on the soil sample, the pH, and the metallic ions in the liquid phase.

Sorimachi, Atsuyuki; Sakamoto, Kazuhiko

170

Sulfur dioxide treatment from flue gases using a biotrickling filter-bioreactor system.  

PubMed

Complete treatment of sulfur dioxide (SO2) from flue gases in a two-stage process consisting of a biotrickling filter followed by biological post-treatment unit was investigated. The biotrickling filter could remove 100% of influent SO2 from simulated flue gas at an empty bed residence time of 6 s for a concentration range of 300-1000 ppm(v). All the absorbed SO2 was recovered in the biotrickling filter liquid effluent as sulfite (a product of chemical reaction of SO2) and sulfate (product of biological oxidation of sulfite). The biotrickling filter liquid effluent was further processed biologically in a single post-treatment unit consisting of a combined anaerobic and microaerophilic reactor for the simultaneous reduction of sulfate and sulfite to sulfide and oxidation of sulfide to elemental sulfur. The post-treatment unit could effectively treat the biotrickling filter effluent and produce elemental sulfur. The sulfur production efficiency of the reactor reached about 80% of the SO2 treated. This new biological treatment system seems to be a promising alternative for flue gas desulfurization. PMID:12775074

Philip, Ligy; Deshusses, Marc A

2003-05-01

171

Surface oxidation of Zircaloy-4 at 600 K by adsorbed oxygen, nitric oxide, and sulfur dioxide  

NASA Astrophysics Data System (ADS)

Understanding and controlling the formation of surface oxides on Zircaloy-4 (Zry-4) surfaces in the presence of nitrogen or sulfur at high temperatures is of interest in applications where this alloy serves as a structural material. In this article we monitor the adsorption of gases on Zry-4 surfaces at 600 K using Auger electron spectroscopy. We find that sulfur dioxide (SO 2), nitric oxide (NO), and isotopic oxygen ( 18O 2) all result in the formation of surface oxides. The presence of sulfur on the surface is reflected both in an increase in the intensity of the overlapping [Zr(MNV) + S(LMM)] feature and its shift toward higher kinetic energies. On the other hand, since oxide formation results in shifts of the Zr(MNV) Auger transition toward lower energies, opposite to what the presence of sulfur does, we also obtain useful information from the Zr(MNN) transition. Although exposure to oxygen results in the largest oxygen concentration near the surface, all the three adsorbates shift the Zr(MNN) feature by about 1.5-2.0 eV, indicative of surface oxidation.

Stojilovic, N.; Ramsier, R. D.

2006-04-01

172

Sulfur uptake by type I collagen from methyl mercaptan/dimethyl disulfide air mixtures  

SciTech Connect

Type I acid-soluble collagen, suspended in 0.02 M Tris/0.13 M NaCl buffer (pH 7.4), was exposed to air atmosphere admixed with 10.7 X 10(-9) moles of (35S)-labeled dimethyl disulphide/methyl mercaptan mixture in the ratio of 99.82% (CH3S)2/0.18% CH3SH. Gas chromatographic analyses of head-space following one and four days of incubation indicated that all of the CH3SH was absorbed from the head-space by the collagen-containing liquid phase, while the (CH3S)2 concentration of the head-space remained essentially unchanged. Of the total (35S)-activity initially present in the head-space, only 1.0 the total (35S)-activity initially present in the head-space, only 1.0 and 1.86% was absorbed by the collagen-containing liquid phase within one and four days, respectively. Paper chromatographic separation of the reaction mixture showed that only 0.42 and 0.60% of the radioactivity in the head-space was associated with collagen after one and four days of reaction. In comparable (35S)-H2S systems devoid of (CH3S)2, all of the H2S was absorbed within 48 hours of incubation with 18.04% (1 day) and 18.28% (4 days) of the available (35S)-H2S complexed with collagen. The results provide evidence that the reaction of collagen with H2S and CH3SH/(CH3S)2 mixture proceeded via the H2S and CH3SH thiol groups.

Johnson, P.W.; Tonzetich, J.

1985-12-01

173

Atmospheric conversion of sulfur dioxide to particulate sulfate and nitrogen dioxide to particulate nitrate and gaseous nitric acid in an urban area  

Microsoft Academic Search

Sulfur dioxide, nitrogen dioxide, particulate sulfate and nitrate, gaseous nitric acid, ozone and meteorological parameters (temperature and relative humidity) were measured during the winter season (1999–2000) and summer season (2000) in an urban area (Dokki, Giza, Egypt). The average particulate nitrate concentrations were 6.20 and 9.80 ?gm?3, while the average gaseous nitric acid concentrations were 1.14 and 6.70 ?gm?3 in

M. I Khoder

2002-01-01

174

EVALUATION OF PROTON-CONDUCTING MEMBRANES FOR USE IN A SULFUR-DIOXIDE DEPOLARIZED ELECTROLYZER  

SciTech Connect

The chemical stability, sulfur dioxide transport, ionic conductivity, and electrolyzer performance have been measured for several commercially available and experimental proton exchange membranes (PEMs) for use in a sulfur dioxide depolarized electrolyzer (SDE). The SDE's function is to produce hydrogen by using the Hybrid Sulfur (HyS) Process, a sulfur based electrochemical/thermochemical hybrid cycle. Membrane stability was evaluated using a screening process where each candidate PEM was heated at 80 C in 60 wt. % H{sub 2}SO{sub 4} for 24 hours. Following acid exposure, chemical stability for each membrane was evaluated by FTIR using the ATR sampling technique. Membrane SO{sub 2} transport was evaluated using a two-chamber permeation cell. SO{sub 2} was introduced into one chamber whereupon SO{sub 2} transported across the membrane into the other chamber and oxidized to H{sub 2}SO{sub 4} at an anode positioned immediately adjacent to the membrane. The resulting current was used to determine the SO{sub 2} flux and SO{sub 2} transport. Additionally, membrane electrode assemblies (MEAs) were prepared from candidate membranes to evaluate ionic conductivity and selectivity (ionic conductivity vs. SO{sub 2} transport) which can serve as a tool for selecting membranes. MEAs were also performance tested in a HyS electrolyzer measuring current density versus a constant cell voltage (1V, 80 C in SO{sub 2} saturated 30 wt% H2SO{sub 4}). Finally, candidate membranes were evaluated considering all measured parameters including SO{sub 2} flux, SO{sub 2} transport, ionic conductivity, HyS electrolyzer performance, and membrane stability. Candidate membranes included both PFSA and non-PFSA polymers and polymer blends of which the non-PFSA polymers, BPVE-6F and PBI, showed the best selectivity.

Hobbs, D.; Elvington, M.; Colon-Mercado, H.

2009-11-11

175

Reducing the sulfur-dioxide binding power of sweet white wines by solid-phase extraction.  

PubMed

The high sulfur-dioxide binding power of sweet white wines may be reduced by extracting the naturally present carbonyl compounds from wine that are responsible for carbonyl bisulphites formation. The carbonyl compounds mainly responsible for trapping SO2 are acetaldehyde, pyruvic acid, and 2-oxoglutaric acid. The method employed was selective solid phase extraction, using phenylsulfonylhydrazine as a scavenging agent. The scavenging function was grafted onto a support prepared from raw materials derived from lignin. This approach is more acceptable to winemakers than the polymer media previously reported, as it reduces the possible contamination of wine to molecules already present in the wine making process. PMID:23768401

Saidane, Dorra; Barbe, Jean-Christophe; Birot, Marc; Deleuze, Hervé

2013-11-01

176

Optimization of TOMS wavelength channels for ozone and sulfur dioxide retrievals  

NASA Astrophysics Data System (ADS)

The wavelengths of the TOMS channels can be optimized to minimize the effects of random measurement errors on simultaneous ozone and sulfur dioxide retrievals. The inversion matrix is extremely sensitive to the spectral position of the channels due to mathematical singularities related to O3 and SO2 absorption coefficients. None of the current sets of wavelengths in the TOMS instruments are optimal for the low latitude retrievals considered. Minor adjustment of the wavelengths can reduce retrieval errors by more than a factor of two.

Gurevich, G. S.; Krueger, Arlin J.

1997-09-01

177

Reactions for improving efficiencies in thermochemical cycles related to the sulfur dioxide-iodine process  

NASA Astrophysics Data System (ADS)

A modification of the sulfur dioxide iodine cycle which uses magnesium oxide, magnesium sulfite and magnesium iodide is examined with particular emphasis on decreasing the amount of water employed and thereby increasing the efficiency. The key reaction is that of iodine with magnesium oxide and magnesium sulfite hexahydrate with no additional water. This produces 77% of the total possible sulfate as well as magnesium iodide, hydrogen iodide and hydrogen at 523 K. The efficiency of this cycle varies between 58% and 39% depending on the amount of heat that can be recovered. This is the first example of a cycle where there is no large energy burden due to evaporation.

Mason, C. F. V.; Bowman, M. G.

1982-06-01

178

Sulfur Dioxide  

MedlinePLUS

... SO 2 : Basic Information - Basics about SO 2 air pollution. Health - Effects of SO 2 air pollution. SO 2 Primary Standards - Links to technical information ... Implementation - Programs and requirements for reducing SO 2 air pollution. Regulatory Actions - Links to proposed and final rules, ...

179

Adsorption of sulfur dioxide by CoFe2O4 spinel ferrite nanoparticles and corresponding changes in magnetism.  

PubMed

Adsorption of sulfur dioxide on 10 nm CoFe(2)O(4) spinel ferrite nanoparticles was examined. Adsorption loadings of sulfur dioxide at breakthrough conditions were determined to be approximately 0.62 mol/kg, which is significant given the 150 m(2)/g surface area of the nanoparticles. Adsorption proceeds through a chemisorption mechanism with sulfur dioxide forming a sulfate upon adsorption on the particle surface, which leads to a 23% decrease in the remnant magnetization, a 20% decrease in the saturation magnetization, and a 9% decrease in the coercivity of the magnetic nanoparticles. Adsorbent materials that provide a magnetic signal when adsorption occurs could have broad implications on adsorption-based separations. PMID:22400990

Glover, T Grant; Sabo, Daniel; Vaughan, Lisa A; Rossin, Joseph A; Zhang, Z John

2012-04-01

180

Effect of oil mists on the irritancy of sulfur dioxide. I. Mineral oils and light lubricating oil.  

PubMed

The increase in pulmonary flow resistance in unanesthetized guinea pigs was used to assess the effect of sub-micrometer oil aerosols on the response to sulfur dioxide. At a concentration of about 10 mg/m3 neither a medicinal grade mineral oil nor a light lubricating oil altered the response when given simultaneously with 1 or 10 ppm sulfur dioxide. The naphthenic medicinal oil at 100 mg/m3 failed to protect against 50 ppm sulfur dioxide when administerd simultaneously. A 30-minute pre-exposure, however, conferred complete protection. A paraffinic laboratory grade mineral oil conferred protection when given simultaneously but was less effective when the pre-exposure protocol was used. PMID:495470

Costa, D L; Amdur, M O

1979-08-01

181

On the Decadal Variation of sulfur dioxide at the Cloud Top of Venus  

NASA Astrophysics Data System (ADS)

Venus atmosphere is a natural laboratory of sulfur chemistry. As one of the parent species of sulfur, sulfur dioxide (SO_2) is generated in the lower atmosphere and transported upward to the middle atmosphere, where it is further oxidized and eventually produces sulfuric acid cloud. The 30-year observations from the Pioneer Venus (Esposito et al., 1988) and the Venus Express (Marcq et al., 2012) show a decadal variation of total column abundance of SO_2 above the cloud top. The amplitude varies in about two orders of magnitude and therefore poses a question on what causes such a dramatic change on the sulfur budget. Previous interpretations include episodic volcanic eruption (Esposito 1984) and long-time dynamical oscillations (Marcq et al., 2012) that supported by a recent general circulation model on Venus (Parish et al., 2011). Here we attempt to understand the secular variation of SO_2 using a one-dimensional (1D) time-evolving photochemistry-diffusion model which includes about 50 species and about 350 reactions (Zhang et al., 2010; 2011). Specifically for this study, we perturb the mean steady state of the middle atmosphere of Venus by adding forcings at the bottom layer (at about 58 km). Two types of forcing are considered here: (1) the volcanic eruption is simulated by a mass flux injected from the bottom layer; and (2) a wavy structure is provided on the eddy diffusion profile to approximate the dynamical perturbations. Important parameters such as the amplitude and timescale of the forcings are constrained by the observation secular patterns. Possible consequences are discussed and the variations for other species are predicted to guide the future observations. This research was supported by the Bisgrove scholar Program in the University of Arizona.

Zhang, Xi

182

Assessment of the UV camera sulfur dioxide retrieval for point source plumes  

USGS Publications Warehouse

Digital cameras, sensitive to specific regions of the ultra-violet (UV) spectrum, have been employed for quantifying sulfur dioxide (SO2) emissions in recent years. The instruments make use of the selective absorption of UV light by SO2 molecules to determine pathlength concentration. Many monitoring advantages are gained by using this technique, but the accuracy and limitations have not been thoroughly investigated. The effect of some user-controlled parameters, including image exposure duration, the diameter of the lens aperture, the frequency of calibration cell imaging, and the use of the single or paired bandpass filters, have not yet been addressed. In order to clarify methodological consequences and quantify accuracy, laboratory and field experiments were conducted. Images were collected of calibration cells under varying observational conditions, and our conclusions provide guidance for enhanced image collection. Results indicate that the calibration cell response is reliably linear below 1500 ppm m, but that the response is significantly affected by changing light conditions. Exposure durations that produced maximum image digital numbers above 32 500 counts can reduce noise in plume images. Sulfur dioxide retrieval results from a coal-fired power plant plume were compared to direct sampling measurements and the results indicate that the accuracy of the UV camera retrieval method is within the range of current spectrometric methods. ?? 2009 Elsevier B.V.

Dalton, M.P.; Watson, I.M.; Nadeau, P.A.; Werner, C.; Morrow, W.; Shannon, J.M.

2009-01-01

183

Evaluation of injury to expanded and expanding leaves of peas exposed to sulfur dioxide and ozone  

SciTech Connect

Necrosis, chlorophyll concentration, dry weight and surface area measurements were made to evaluate injury to leaves of Pisum sativum L. cv Alsweet grown under controlled environments and exposed to sulfur dioxide, ozone and combinations of sulfur dioxide plus ozone. Injury evaluations were made at low pollutant levels causing slight necrotic injury and high levels causing severe necrotic injury. At low levels, expanded leaves with a trace of necrotic injury had a 10% reduction in chlorophyll concentration but no reductions in dry weight or surface area, while expanding leaves, also with a trace of necrotic injury, had a reduction in chlorophyll concentration accompanied by reductions in dry weight and surface area. At high pollutant levels, expanded leaves with severe necrotic injury had a 70% reduction in chlorophyll concentration and significant reductions in dry weight and surface area, while expanding leaves had a smaller amount of necrotic injury and a smaller reduction in chlorophyll concentration, but reductions in dry weight and surface area similar to those in expanded leaves. Thus, the following measurements are proposed as reliable indicators of injury at pollutant concentrations just above the threshold for injury: chlorophyll concentration for expanded leaves and surface area for expanding leaves. Reliable indicators of injury at higher concentrations causing serious injury to leaves are: necrosis for expanded leaves and chlorophyll concentration, dry weight, and surface area for expanding leaves. 19 references, 4 figures, 3 tables.

Olszyk, D.M.; Tibbitts, T.W.

1982-03-01

184

The distribution of sulfur dioxide and other infrared absorbers on the surface of Io  

USGS Publications Warehouse

The Galileo Near Infrared Mapping Spectrometer was used to investigate the distribution and properties of sulfur dioxide over the surface of Io, and qualitative results for the anti-Jove hemisphere are presented here. SO2, existing as a frost, is found almost everywhere, but with spatially variable concentration. The exceptions are volcanic hot spots, where high surface temperatures promote rapid vaporization and can produce SO2-free areas. The pervasive frost, if fully covering the cold surface, has characteristic grain sizes of 30 to 100 Urn, or greater. Regions of greater sulfur dioxide concentrations are found. The equatorial Colchis Regio area exhibits extensive snowfields with large particles (250 to 500 ??m diameter, or greater) beneath smaller particles. A weak feature at 3.15 ??m is observed and is perhaps due to hydroxides, hydrates, or water. A broad absorption in the 1 ??m region, which could be caused by iron-containing minerals, shows a concentration in Io'S southern polar region, with an absence in the Pele plume deposition ring. Copyright 1997 by the American Geophysical Union.

Carlson, R.W.; Smythe, W.D.; Lopes-Gautier, R. M. C.; Davies, A.G.; Kamp, L.W.; Mosher, J.A.; Soderblom, L.A.; Leader, F.E.; Mehlman, R.; Clark, R.N.; Fanale, F.P.

1997-01-01

185

Reactions of Sulfur Dioxide with Neutral Vanadium Oxide Clusters in the Gas Phase. II. Experimental Study Employing Single-Photon Ionization  

E-print Network

Reactions of Sulfur Dioxide with Neutral Vanadium Oxide Clusters in the Gas Phase. II. Experimental employed for the study of the reactions of neutral vanadium oxide clusters (VmOn) with sulfur dioxide (SO2) in the gas phase. VmOn clusters are generated by reaction of a laser-generated vanadium plasma with O2

Rocca, Jorge J.

186

FIELD TESTING TO DETERMINE THE PRESENCE OR ABSENCE OF SULFUR DIOXIDE EMISSIONS FROM OLD IN SITU OIL SHALE FIELD-SITES  

EPA Science Inventory

One of the major technology needs in the development of the oil shale industry is to adopt and develop methods for controlling the release of pollutants to the environment. Large quantities of sulfur dioxide may be generated from oil shale retorting operations. Sulfur dioxide is ...

187

[Spatial distribution of sulfur dioxide around a tobacco bulk-curing workshop cluster].  

PubMed

In order to manifest lower energy consumption and less labor employment, and provide the theoretical basis for constructing environmentally friendly modem tobacco agriculture, this paper analyzed gas composition of the chimney from a bulk-curing barn and the dispersion of sulfur dioxide (SO2) around the workshop cluster using ecom-J2KN flue gas analyzer and air sampler. During curing, the concentrations of carbon dioxide (CO2) and SO2 in the chimney were both highest at 38 degrees C, while the concentration of nitrogen oxides (NOx) was highest at 42 degrees C. The emission concentration of SO2 from the chimney was 1327.60-2218.40 mg x m(-3). Average SO2 emission would decrease by 49.7% through adding 4.0% of a sulfur-fixed agent. The highest concentrations of SO2 in the surface soil appeared at the yellowing stage. SO2 concentration in horizontal direction localized at 43-80 m exceeded 0.5 mg x m(-3). The highest concentration of SO2 (0.57 mg x m(-3)) was observed at 50 m. At 50 m in the downstream wind direction of the workshop cluster, SO2 concentration in vertical direction localized at 0.9-1.8 m exceeded 0.5 mg x m(-3), and the highest concentration of SO2 in vertical direction was 0.65 mg x m(-3) at 1.6 m. During curing, the average concentration of SO2 was decreased by 0.43 mg x m(-3) by using the sulfur-fixed agent. The polluted boundary was localized at 120 m in the downstream wind direction of the workshop cluster. PMID:24984508

He, Fan; Wang, Mei; Wang, Tao; Sun, Jian-Feng; Huang, Wu-Xing; Tian, Bin-Qiang; Gong, Chang-Rong

2014-03-01

188

Microbial reduction of sulfur dioxide with anaerobically digested municipal sewage biosolids as electron donors.  

PubMed

A concentrated stream of sulfur dioxide (SO2) is produced by regeneration of the sorbent in certain new regenerable processes for the desulfurization of flue gas. We have previously proposed that this SO2 can be converted to elemental sulfur for disposal or byproduct recovery using a microbial/Claus process. In this process, two-thirds of the SO2-reducing gas stream would be contacted with a mixed culture containing sulfate-reducing bacteria (SRB), where SO2 would act as an electron acceptor with reduction to hydrogen sulfide (H2S). This H2S could then be recombined with the remaining SO2 and sent to a Claus unit to produce elemental sulfur. The sulfate-reducing bacterium, Desulfovibrio desulfuricans, has been immobilized by coculture with flocforming heterotrophs from an anaerobic digester, resulting in a SO2-reducing floc that may be collected from the effluent of a continuous reactor for recycle by gravity sedimentation. The carbon and energy source for these cultures was anaerobically digested municipal sewage solids. The maximum specific activity for SO2 reduction in these cultures, in terms of dry weight of D. desulfuricans biomass, was 9.1 mmol of SO2/h.g. The stoichiometry with respect to the electron donor was 15.5 mg of soluble COD/mmol of SO2 reduced. PMID:7766099

Selvaraj, P T; Sublette, K L

1995-01-01

189

Global dry deposition of nitrogen dioxide and sulfur dioxide inferred from space-based measurements  

NASA Astrophysics Data System (ADS)

A method is developed to estimate global NO2 and SO2 dry deposition fluxes at high spatial resolution (0.1°×0.1°) using satellite measurements from the Ozone Monitoring Instrument (OMI) on the Aura satellite, in combination with simulations from the Goddard Earth Observing System chemical transport model (GEOS-Chem). These global maps for 2005-2007 provide a data set for use in examining global and regional budgets of deposition. In order to properly assess SO2 on a global scale, a method is developed to account for the geospatial character of background offsets in retrieved satellite columns. Globally, annual dry deposition to land estimated from OMI as NO2 contributes 1.5 ± 0.5 Tg of nitrogen and as SO2 contributes 13.7 ± 4.0 Tg of sulfur. Differences between OMI-inferred NO2 dry deposition fluxes and those of other models and observations vary from excellent agreement to an order of magnitude difference, with OMI typically on the low end of estimates. SO2 dry deposition fluxes compare well with in situ Clear Air Status and Trends Network-inferred flux over North America (slope = 0.98, r = 0.71). The most significant NO2 dry deposition flux to land per area occurs in the Pearl River Delta, China, at 13.9 kg N ha-1 yr-1, while SO2 dry deposition has a global maximum rate of 72.0 kg S ha-1 yr-1 to the east of Jinan in China's Shandong province. Dry deposition fluxes are explored in several urban areas, where NO2 contributes on average 9-36% and as much as 85% of total NOy dry deposition.

Nowlan, C. R.; Martin, R. V.; Philip, S.; Lamsal, L. N.; Krotkov, N. A.; Marais, E. A.; Wang, S.; Zhang, Q.

2014-10-01

190

Use of stable sulfur isotope systematics for evaluating oxidation reaction pathways and in-cloud-scavenging of sulfur dioxide in the atmosphere  

SciTech Connect

Sulfur dioxide injected into the atmosphere is most likely oxidized into sulfate. Two major oxidation pathways are possible: (1) a homogeneous pathway involving gas reaction with hydroxyl radicals and (2) a heterogeneous pathway involving aqueous dissolution or aerosol reactions. The relative importance of these reaction pathways conditions is controversial. Sulfur isotope ratios can be used to quantify the relative importance of these reaction pathways. However, its application was severely hampered by the fact that the isotope fractionation factor for the homogeneous pathway was not known. A significant isotope fractionation in the homogeneous SO[sub 2] oxidation is identified for the first time using an ab initio quantum mechanical calculation. By using the sulfur isotope fractionation factors the authors demonstrate a technique that uses measurements of the sulfur isotope ratio in gaseous SO[sub 2], aerosol SO[sub 4] and sulfate in wet precipitation to quantify the relative importance of the homogeneous and heterogeneous reaction pathways as well as the in-cloud scavenging of sulfur dioxide for a set of isotopic observations at New Haven, CT, USA. 15 refs., 1 fig., 2 tabs.

Tanaka, Noriyuki; Rye, D.M.; Xiao, Yitian; Lasaga, A.C. (Yale Univ., New Haven, CT (United States))

1994-07-01

191

FLUX DETERMINATION AND PHYSIOLOGICAL RESPONSE IN THE EXPOSURE OF RED SPRUCE TO GASEOUS HYDROGEN PEROXIDE, OZONE, AND SULFUR DIOXIDE  

EPA Science Inventory

We report on the 3-week exposure of a branch of a forest-grown red spruce (Picea rubens) sapling to the combination of gaseous hydrogen peroxide. ozone, and sulfur dioxide. he exposure was conducted continuously using concentrations of H2O2, O3, and SO2 that have been observed du...

192

The Social Cost of Trading: Measuring the Increased Damages from Sulfur Dioxide Trading in the United States  

ERIC Educational Resources Information Center

The sulfur dioxide (SO[subscript 2]) cap and trade program established in the 1990 Clean Air Act Amendments is celebrated for reducing abatement costs ($0.7 to $2.1 billion per year) by allowing emissions allowances to be traded. Unfortunately, places with high marginal costs also tend to have high marginal damages. Ton-for-ton trading reduces…

Henry, David D., III; Muller, Nicholas Z.; Mendelsohn, Robert O.

2011-01-01

193

UTILIZATION OF A RESPONSE-SURFACE TECHNIQUE IN THE STUDY OF PLANT RESPONSES TO OZONE AND SULFUR DIOXIDE MIXTURES  

EPA Science Inventory

A second order rotatable design was used to obtain polynomial equations describing the effects of combinations of sulfur dioxide (SO2) and ozone (O3) on foliar injury and plant growth. The response surfaces derived from these equations were displayed as contour or isometric (3-di...

194

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

SciTech Connect

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

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

1985-08-01

195

[Research on denoising fluorescence signal of sulfur dioxide by Boxcar filter].  

PubMed

The fluorescence detection method is based on the linear relationship between fluorescence intensity emitted by the material and the concentration of material to make a quantitative analysis. When using the fluorescence detection of atmospheric sulfur dioxide and other harmful gases, photodetectors and other optoelectronic components without fluorescence will continue to produce the dark current noise, and the background signal has a direct impact on the measurement results. On the base of analysis Boxcar filtering algorithm, the research used three algorithms of wavelet filtering, EMD filter and Boxcar filter to extract and recover the fluorescence signal drowned in the noise floor. In comparison with the previous two filtering methods, Boxcar filter had a better effect on the suppression of the background noise. It also verified that the number of sampling affects the fluorescence signal to noise ratio improvement. PMID:23427553

Wang, Yu-Tian; Jian, Xiong; Wang, Hui-Xin; Yan, Bing

2012-12-01

196

Tree-ring variation in western larch (Larix occidentalis Nutt. ) exposed to sulfur dioxide emissions  

SciTech Connect

Tree-ring analysis of western larch (Larix occidentialis Nutt) demonstrated both direct and indirect affects of sulfur dioxide emissions from the lead/zinc smelter at Trail, B.C. Tree cores were collected from 5 stands known to have been polluted and from 3 control stands. Age effects were removed by fitting theoretical growth curves, and macrocliate was modeled using the average of the controls and two laged values thereof. Separate analyses were performed for years before and after installation of two tall stacks, for drought and nondrought years, and for years prior to initiation of smelting. Regression analyses revealed a negative effect on annual growth that diminished with increasing distance from the smelter and during drought years. Furthermore, chronology statistics suggested an increase in sensitivity to climate that persisted decades beyond implementation of pollution controls, which reduced emissions 10-fold. 38 references, 6 figures, 3 tables.

Fox, C.A.; Kincaid, W.B.; Nash, T.H. III; Young, D.L.; Fritts, H.C.

1984-12-01

197

Evaluation of high Ni-Cr-Mo alloys for the construction of sulfur dioxide scrubber plants  

NASA Astrophysics Data System (ADS)

Corrosion in wet lime/limestone systems used for flue gas desulfurization in thermal power plants is of great concern. The frequent variations in acidity and in chloride and fluoride ion concentrations experienced by such systems pose a serious threat to the materials of construction. Currently used materials mostly type 316L stainless steel often fail to meet their life expectancy. The present study evaluates the performance of advanced Ni- Cr- Mo alloys 59 and C- 276 in a simulated sulfur dioxide scrubber environment. Accelerated tests showed that high Ni- Cr- Mo alloys have little tendency to leach metal ions such as chromium, nickel, and molybdenum at different impressed potentials. Scanning electron microscopy was used to examine the morphology of pitting attack.

Rajendran, N.; Rajeswari, S.

1996-02-01

198

The impact of sulfur dioxide on plant sexual reproduction: in vivo and in vitro effects compared  

SciTech Connect

In Lepidium virginicum L., exposure of pollen to 0.6 ppm sulfur dioxide (SO/sub 2/) for 4 h reduced pollen germination in vitro 94% from the control, whereas exposure to 0.6 ppm SO/sub 2/ for 2, 4, and 8 h during flowering reduced pollen germination in vivo 50% from the control, but did not affect seed set.An interaction between SO/sub 2/ and water may have caused the inhibition of pollen germination in a liquid culture medium, as well as on the moist surface of an intact stigma. However, the results suggest that the use of pollen germination and pollen tube elongation in vitro to asses the direct effects of SO/sub 2/ on plant sexual reproduction in vivo is not valid.

DuBay, D.T. (Air Quality Field Lab., Raleigh, NC); Murdy, W.H.

1983-01-01

199

Clinical and laboratory features of acute sulfur dioxide inhalation poisoning: two-year follow-up  

SciTech Connect

We present clinical and laboratory results (including nuclear imaging) obtained over a period of two years in two nonsmoking miners who were exposed to high concentrations of sulfur dioxide (SO/sub 2/) after a mine explosion. Within 3 wk of the accident, both miners had evidence of severe airways obstruction, hypoxemia, markedly reduced exercise tolerance, ventilation-perfusion mismatch, and evidence of active inflammation as documented by positive gallium lung scan. Serial ventilation-perfusion scans over the first 12 months showed progressive improvement without returning to normal. After the initial recovery, there has been no significant change over the subsequent two years postinjury. Pulmonary function and exercise tests also displayed a similar pattern of initial improvement. We conclude that (1) acute exposure to high concentrations of SO/sub 2/ results in severe airways obstruction, (2) pulmonary function abnormalities are partially reversible, and (3) most of the improvement occurs within 12 months after the initial injury.

Rabinovitch, S.; Greyson, N.D.; Weiser, W.; Hoffstein, V.

1989-02-01

200

Monitoring of sulfur dioxide emission resulting from biogas utilization on commercial pig farms in Taiwan.  

PubMed

The objective of this work tends to promote methane content in biogas and evaluate sulfur dioxide emission from direct biogas combustion without desulfurization. Analytical results of biogas combustion showed that combustion of un-desulfurized biogas exhausted more than 92 % of SO2 (P?

Su, Jung-Jeng; Chen, Yen-Jung

2015-01-01

201

Improving volcanic sulfur dioxide cloud dispersal forecasts by progressive assimilation of satellite observations  

NASA Astrophysics Data System (ADS)

Forecasting the dispersal of volcanic clouds during an eruption is of primary importance, especially for ensuring aviation safety. As volcanic emissions are characterized by rapid variations of emission rate and height, the (generally) high level of uncertainty in the emission parameters represents a critical issue that limits the robustness of volcanic cloud dispersal forecasts. An inverse modeling scheme, combining satellite observations of the volcanic cloud with a regional chemistry-transport model, allows reconstructing this source term at high temporal resolution. We demonstrate here how a progressive assimilation of freshly acquired satellite observations, via such an inverse modeling procedure, allows for delivering robust sulfur dioxide (SO2) cloud dispersal forecasts during the eruption. This approach provides a computationally cheap estimate of the expected location and mass loading of volcanic clouds, including the identification of SO2-rich parts.

Boichu, Marie; Clarisse, Lieven; Khvorostyanov, Dmitry; Clerbaux, Cathy

2014-04-01

202

Reversible chemisorption of sulfur dioxide in a spin crossover porous coordination polymer.  

PubMed

The chemisorption of sulfur dioxide (SO2) on the Hofmann-like spin crossover porous coordination polymer (SCO-PCP) {Fe(pz)[Pt(CN)4]} has been investigated at room temperature. Thermal analysis and adsorption-desorption isotherms showed that ca. 1 mol of SO2 per mol of {Fe(pz)[Pt(CN)4]} was retained in the pores. Nevertheless, the SO2 was loosely attached to the walls of the host network and completely released in 24 h at 298 K. Single crystals of {Fe(pz)[Pt(CN)4]}·nSO2 (n ? 0.25) were grown in water solutions saturated with SO2, and its crystal structure was analyzed at 120 K. The SO2 molecule is coordinated to the Pt(II) ion through the sulfur atom ion, Pt-S = 2.585(4) Å. This coordination slightly stabilizes the low-spin state of the Fe(II) ions shifting the critical temperatures of the spin transition by 8-12 K. DFT calculations have been performed to rationalize these observations. PMID:24124923

Arcķs-Castillo, Zulema; Muńoz-Lara, Francisco J; Muńoz, M Carmen; Aravena, Daniel; Gaspar, Ana B; Sįnchez-Royo, Juan F; Ruiz, Eliseo; Ohba, Masaaki; Matsuda, Ryotaro; Kitagawa, Susumu; Real, José A

2013-11-01

203

Comparative Analyses of Physiological Responses of Cynodon dactylon Accessions from Southwest China to Sulfur Dioxide Toxicity  

PubMed Central

Sulfur dioxide (SO2), a major air pollutant in developing countries, is highly toxic to plants. To achieve better air quality and landscape, planting appropriate grass species in severe SO2 polluted areas is very critical. Cynodon dactylon, a widely used warm season turfgrass species, has good SO2-tolerant ability. In this study, we selected 9 out of 38 C. dactylon accessions from Southwest China as representatives of high, intermediate SO2-tolerant and SO2-sensitive accessions to comparatively analyze their physiological differences in leaves under SO2 untreated and treated conditions. Our results revealed that SO2-tolerant C. dactylon accessions showed higher soluble sugar, proline, and chlorophyll a contents under both SO2 treated and untreated conditions; higher chlorophyll b and carotenoid under SO2 treated condition; lower reactive oxygen species (ROS) level, oxidative damages, and superoxide dismutase (SOD) activities under SO2 treated condition; and higher peroxidase (POD) activities under SO2 untreated condition. Further results indicated that SO2-tolerant C. dactylon accessions had higher sulfur contents under both SO2 treated and untreated conditions, consistent with higher SO activities under both SO2 treated and untreated conditions, and higher SiR activities under SO2 treated condition. Taken together, our results indicated that SO2 tolerance of C. dactylon might be largely related to soluble sugar, proline and chlorophyll a contents, and SO enzyme activity. PMID:25097893

Wang, Ling; Li, Yiqiao; Cai, Shizhen

2014-01-01

204

Sulfur dioxide in the atmosphere of Venus 1 sounding rocket observations  

NASA Technical Reports Server (NTRS)

In this paper we present ultraviolet reflectance spectra obtained during two sounding rocket observations of Venus made during September 1988 and March 1991. We describe the sensitivity of the derived reflectance to instrument calibration and show that significant artifacts can appear in that spectrum as a result of using separate instruments to observe both the planetary radiance and the solar irradiance. We show that sulfur dioxide is the primary spectral absorber in the 190 - 230 nm region and that the range of altitudes probed by these wavelengths is very sensitive to incidence and emission angles. In a following paper Na et. al. (1994) show that sulfur monoxide features are also present in these data. Accurate identification and measurement of additional species require observations in which both the planetary radiance and the solar irradiance are measured with the same instrument. The instrument used for these observations is uniquely suited for obtaining large phase angle coverage and for studying transient atmospheric events on Venus because it can observe targets within 18 deg of the sun while earth orbiting instruments are restricted to solar elongation angles greater than or equal to 45 deg.

Mcclintock, William E.; Barth, Charles A.; Kohnert, Richard A.

1994-01-01

205

Dynamic analysis of sulfur dioxide monthly emissions in United States power plants  

NASA Astrophysics Data System (ADS)

The Clean Air Act Amendments (CAAA) of 1990 marked a moving away from command-and-control air quality regulations towards a market-based approach, whereby polluters are assigned annual emission allowances, and are free to select the minimum-cost approach that will keep their actual annual emissions within this allowance limit. Within this context, the objectives of this research are to better understand (1) the temporal patterns of SO 2 emissions from power plants, and (2) the factors affecting fuel choice and SO2 emissions. Large power plant-related datasets from various sources are collected, processed, and combined for empirical analyses, to explain monthly fuel shipments, fuel consumptions, sulfur shipments, gross and net SO 2 emissions, and fuel choices. Because of the interdependency of these various sulfur dioxide, simultaneous equations estimation techniques are used. The empirical findings are as follows. First, forecasts of electricity demand and fuel prices are the main determinants of the amounts and types of fuel shipments. The relationship between fuel shipments and forecasted fuel needs is very strong for the current month, and gradually weakens over future months, due to forecasting difficulties and the costs of fuel inventories. Second, net SO2 emissions increase with allowances, although not proportionately, because of the likely effects of allowance banking and trading. Third, each plant reduces SO2 emissions gradually over time, to account for the future more stringent Phase II emissions constraints. Fourth, plants emit less in winter, possibly because higher electricity leads to reduced unit SO2 emission abatement costs. Finally, plants with an FGD usually consume more high-sulfur fuels due to their potential abatement capability. An integrated analysis of the effects of changing emission allowances and installing FGD is conducted through a simulation. Reducing allowances by 1% leads to an emissions reduction of 0.15% at the plant level. However, if allowances were reduced uniformly nationwide, this effect would be stronger because of reduced allowance trading opportunities.

Kim, Tae-Kyung

206

Sulfur dioxide in the Venus atmosphere measured by SOIR on board Venus Express  

NASA Astrophysics Data System (ADS)

SO2 is a key constituent of the Venus mesosphere, playing an important role in the atmosphere chemistry, as it is a product of the photodisociation of the clouds constituent, H2SO4. New SO2 observations are important in the frame of constraining Global Computation Models (GCM), which simulate the circulation and the chemistry of the Venus atmosphere. The SOIR instrument flying on board the Venus Express spacecraft records infrared spectra of the Venus atmosphere, using the solar occultation technique. Amongst the species absorbing in the SOIR wavelength range, sulfur dioxide presents a weak band, from which regular observations are obtained in the 60 to 100 km altitude region. We derive number density and volume mixing ratio vertical profiles. Total density and temperature profiles are obtained from the carbon dioxide number density profiles. This study presents the latitude and temporal variations observed between 2006 and 2013. The results are compared to literature data and discussed. Future work will consist of including and comparing the data to Venus GCM.

Mahieux, Arnaud; Carine Vandaele, Ann; Drummond, Rachel; Robert, Séverine; Wilquet, Valérie; Belyaev, Denis; Bertaux, Jean-Loup

2014-05-01

207

Conjugated processes of the chemical transformation of sulfur dioxide under the effect of chain gas-phase reactions  

NASA Astrophysics Data System (ADS)

The effect sulfur dioxide has on the dynamics of the spontaneous ignition of hydrogen-oxygen mixtures is studied. Additives of SO2 have no negative effect on spontaneous ignition and undergo chemical conversion to form elemental sulfur. The results are analyzed using the theory of branched chain reactions along with data on SO2 conversion under the action of chain reactions of hydrocarbon oxidation and slow hydrogen oxidation. The transformations classified as parallel reactions from the viewpoint of formal kinetics could actually be conjugated radical-chain processes.

Mantashyan, A. A.

2015-01-01

208

Sulfur dioxide and primary carbonaceous aerosol emissions in China and India, 1996-2010  

NASA Astrophysics Data System (ADS)

China and India are the two largest anthropogenic aerosol generating countries in the world. In this study, we develop a new inventory of sulfur dioxide (SO2) and primary carbonaceous aerosol (i.e., black and organic carbon, BC and OC) emissions from these two countries for the period 1996-2010, using a technology-based methodology. Emissions from major anthropogenic sources and open biomass burning are included, and time-dependent trends in activity rates and emission factors are incorporated in the calculation. Year-specific monthly temporal distributions for major sectors and gridded emissions at a resolution of 0.1°×0.1° distributed by multiple year-by-year spatial proxies are also developed. In China, the interaction between economic development and environmental protection causes large temporal variations in the emission trends. From 1996 to 2000, emissions of all three species showed a decreasing trend (by 9 %-17 %) due to a slowdown in economic growth, a decline in coal use in non-power sectors, and the implementation of air pollution control measures. With the economic boom after 2000, emissions from China changed dramatically. BC and OC emissions increased by 46 % and 33 % to 1.85 Tg and 4.03 Tg in 2010. SO2 emissions first increased by 61 % to 34.0 Tg in 2006, and then decreased by 9.2 % to 30.8 Tg in 2010 due to the wide application of flue-gas desulfurization (FGD) equipment in power plants. Driven by the remarkable energy consumption growth and relatively lax emission controls, emissions from India increased by 70 %, 41 %, and 35 % to 8.81 Tg, 1.02 Tg, and 2.74 Tg in 2010 for SO2, BC, and OC, respectively. Monte Carlo simulations are used to quantify the emission uncertainties. The average 95 % confidence intervals (CIs) of SO2, BC, and OC emissions are estimated to be -16 %-17 %, -43 %-93 %, and -43 %-80 % for China, and -15 %-16 %, -41 %-87 %, and -44 %-92 % for India, respectively. Sulfur content, fuel use, and sulfur retention of hard coal and the actual FGD removal efficiency are the main contributors to the uncertainties of SO2 emissions. Biofuel combustion related parameters (i.e., technology divisions, fuel use, and emission factor determinants) are the largest source of OC uncertainties, whereas BC emissions are also sensitive to the parameters of coal combustion in the residential and industrial sectors and the coke-making process. Comparing our results with satellite observations, we find that the trends of estimated emissions in both China and India are in good agreement with the trends of aerosol optical depth (AOD) and SO2 retrievals obtained from different satellites.

Lu, Z.; Zhang, Q.; Streets, D. G.

2011-09-01

209

Sulfur dioxide and primary carbonaceous aerosol emissions in China and India, 1996-2010  

NASA Astrophysics Data System (ADS)

China and India are the two largest anthropogenic aerosol generating countries in the world. In this study, we develop a new inventory of sulfur dioxide (SO2) and primary carbonaceous aerosol (i.e., black and organic carbon, BC and OC) emissions from these two countries for the period 1996-2010, using a technology-based methodology. Emissions from major anthropogenic sources and open biomass burning are included, and time-dependent trends in activity rates and emission factors are incorporated in the calculation. Year-specific monthly fractions for major sectors and gridded emissions at a resolution of 0.1° × 0.1° distributed by multiple year-by-year spatial proxies are also developed. In China, the interaction between economic development and environmental protection causes large temporal variations in the emission trends. From 1996 to 2000, emissions of all three species showed a decreasing trend (by 9 %-17 %) due to a slowdown in economic growth, a decline in coal use in non-power sectors, and the implementation of air pollution control measures. With the economic boom after 2000, emissions from China changed dramatically. BC and OC emissions increased by 46 % and 33 % to 1.85 Tg and 4.03 Tg in 2010. SO2 emissions first increased by 61 % to 34.0 Tg in 2006, and then decreased by 9.2 % to 30.8 Tg in 2010 due to the wide application of flue-gas desulfurization (FGD) equipment in power plants. Driven by the remarkable energy consumption growth and relatively lax emission controls, emissions from India increased by 70 %, 41 %, and 35 % to 8.81 Tg, 1.02 Tg, and 2.74 Tg in 2010 for SO2, BC, and OC, respectively. Monte Carlo simulations are used to quantify the emission uncertainties. The average 95 % confidence intervals (CIs) of SO2, BC, and OC emissions are estimated to be -16 %-17 %, -43 %-93 %, and -43 %-80 % for China, and -15 %-16 %, -41 %-87 %, and -44 %-92 % for India, respectively. Sulfur content, fuel use, and sulfur retention of hard coal and the actual FGD removal efficiency are the main contributors to the uncertainties of SO2 emissions. Biofuel combustion related parameters (i.e., technology divisions, fuel use, and emission factor determinants) are the largest source of OC uncertainties, whereas BC emissions are also sensitive to the parameters of coal combustion in the residential and industrial sectors and the coke-making process. Comparing our results with satellite observations, we find that the trends of estimated emissions in both China and India are in good agreement with the trends of aerosol optical depth (AOD) and SO2 retrievals obtained from different satellites.

Lu, Z.; Streets, D. G.

2011-07-01

210

Prediction of ground level concentration of sulfur dioxide using ISCST3 model in Mangalore industrial region of India  

Microsoft Academic Search

Ambient air quality management in any industrial area is of prime concern in India considering the industrial growth since\\u000a last two decades. High concentrations of ambient sulfur dioxide (SO2) in many Indian places are responsible for non-compliance of ambient air quality standards. Dispersion modeling finds an\\u000a important tool to simulate the ambient air quality of a region and to predict

Amitava Bandyopadhyay

2009-01-01

211

In-situ surface science studies of the interaction between sulfur dioxide and two-dimensional palladium loaded-cerium/zirconium mixed metal oxide model catalysts  

NASA Astrophysics Data System (ADS)

Cerium and zirconium oxides are important materials in industrial catalysis. Particularly, the great advances attained in the past 30 years in controlling levels of gaseous pollutants released from internal combustion engines can be attributed to the development of catalysts employing these materials. Unfortunately, oxides of sulfur are known threats to the longevity of many catalytic systems by irreversibly interacting with catalytic materials. In this work, polycrystalline cerium-zirconium mixed-metal-oxide (MMO) solid solutions were synthesized. High resolution x-ray photoelectron spectroscopy (XPS) spectral data was collected and examined for revelation of the surface species that form on these metal oxides after in-situ exposures to sulfur dioxide. The model catalysts were exposed to sulfur dioxide using a custom modified in-situ reaction cell and platen heater. The results of this study demonstrate the formation of sulfate and sulfite surface sulfur species. Temperature and compositional dependencies were displayed, with higher temperatures and ceria molar ratios displaying a larger propensity for forming surface sulfur species. In addition to analysis of sulfur photoemission, the photoemission regions of oxygen, zirconium, and cerium were examined for the materials used in this study before and after the aforementioned treatments with sulfur dioxide. The presence of surface hydroxyl groups was observed and metal oxidation state changes were probed to further enhance the understanding of sulfur dioxide adsorption on the synthesized materials. Palladium loaded mixed-metal oxides were synthesized using a unique solid-state methodology to probe the effect of palladium addition on sulfur dioxide adsorption. The addition of palladium to this model system is shown to have a strong effect on the magnitude of adsorption for sulfur dioxide on some material/exposure condition combinations. Ceria/zirconia sulfite and sulfate species are identified on the palladium-loaded MMO materials with adsorption sites located on the exposed oxide sites.

Romano, Esteban Javier

2005-07-01

212

Sulfur Dioxide Emission Rates of Kilauea Volcano, Hawaii, 1979-1997  

USGS Publications Warehouse

INTRODUCTION Sulfur dioxide (SO2) emission rates from Kilauea Volcano were first measured by Stoiber and Malone (1975) and have been measured on a regular basis since 1979 (Casadevall and others, 1987; Greenland and others, 1985; Elias and others, 1993; Elias and Sutton, 1996). The purpose of this report is to present a compilation of Kilauea SO2 emission rate data from 1979 through 1997 with ancillary meteorological data (wind speed and wind direction). We have included measurements previously reported by Casadevall and others (1987) for completeness and to improve the usefulness of this current database compilation. Kilauea releases SO2 gas predominantly from its summit caldera and rift zones (fig. 1). From 1979 through 1982, vehicle-based COSPEC measurements made within the summit caldera were adequate to quantify most of the SO2 emitted from the volcano. Beginning in 1983, the focus of SO2 release shifted from the summit to the east rift zone (ERZ) eruption site at Pu`u `O`o and, later, Kupaianaha. Since 1984, the Kilauea gas measurement effort has been augmented with intermittent airborne and tripod-based surveys made near the ERZ eruption site. In addition, beginning in 1992 vehicle-based measurements have been made along a section of Chain of Craters Road approximately 9 km downwind of the eruption site. These several types of COSPEC measurements continue to the present.

Elias, Tamar; Sutton, A.J.; Stokes, J.B.; Casadevall, T.J.

1998-01-01

213

Sulfur Dioxide Emission Rates from Kilauea Volcano, Hawai`i, an Update: 1998-2001  

USGS Publications Warehouse

Introduction Sulfur dioxide (SO2) emission rates from Kilauea Volcano were first measured by Stoiber and Malone (1975) and have been measured on a regular basis since 1979 (Greenland and others, 1985; Casadevall and others, 1987; Elias and others, 1998; Sutton and others, 2001). A compilation of SO2 emission-rate and wind-vector data from 1979 through 1997 is available as Open-File Report 98-462 (Elias and others, 1998) and on the web at http://hvo.wr.usgs.gov/products/OF98462/. The purpose of this report is to update the existing database through 2001. Kilauea releases SO2 gas predominantly from its summit caldera and east rift zone (ERZ) (fig. 1), as described in previous reports (Elias and others, 1998; Sutton and others, 2001). These two distinct sources are quantified independently. The summit and east rift zone emission rates reported here were derived using vehicle-based Correlation Spectrometry (COSPEC) measurements as described in Elias and others (1998). In 1998 and 1999, these measurements were augmented with airborne and tripod-based surveys.

Elias, Tamar; Sutton, A. Jefferson

2002-01-01

214

Sulfur Dioxide Emission Rates from Kilauea Volcano, Hawai`i, an Update: 2002-2006  

USGS Publications Warehouse

Introduction Sulfur dioxide (SO2) emission rates from Kilauea Volcano were first measured by Stoiber and Malone (1975) and have been measured on a regular basis since 1979 (Greenland and others, 1985; Casadevall and others, 1987; Elias and others, 1998; Sutton and others, 2001, Elias and Sutton, 2002, Sutton and others, 2003). Compilations of SO2 emission-rate and wind-vector data from 1979 through 2001 are available on the web. (Elias and others, 1998 and 2002). This report updates the database through 2006, and documents the changes in data collection and processing that have occurred during the interval 2002-2006. During the period covered by this report, Kilauea continued to release SO2 gas predominantly from its summit caldera and east rift zone (ERZ) (Elias and others, 1998; Sutton and others, 2001, Elias and others, 2002, Sutton and others, 2003). These two distinct sources are always measured independently (fig.1). Sulphur Banks is a minor source of SO2 and does not contribute significantly to the total emissions for Kilauea (Stoiber and Malone, 1975). From 1979 until 2003, summit and east rift zone emission rates were derived using vehicle- and tripod- based Correlation Spectrometry (COSPEC) measurements. In late 2003, we began to augment traditional COSPEC measurements with data from one of the new generation of miniature spectrometer systems, the FLYSPEC (Horton and others, 2006; Elias and others, 2006, Williams-Jones and others, 2006).

Elias, Tamar; Sutton, A.J.

2007-01-01

215

Contrasting effects of sulfur dioxide on cupric oxide and chloride during thermochemical formation of chlorinated aromatics.  

PubMed

Sulfur dioxide (SO2) gas has been reported to be an inhibitor of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) formation in fly ash. However, other research has suggested little or no inhibitory effect of SO2 gas. Although these studies focused on reactions between SO2 gas and gas-phase chlorine (Cl) species, no attention was paid to thermochemical gas-solid reactions. In this study, we found contrasting effects of SO2 gas depending on the chemical form of copper (CuO vs CuCl2) with a solid-phase inorganic Cl source (KCl). Chlorinated aromatics (PCDD/Fs, polychlorinated biphenyls, and chlorobenzenes) increased and decreased in model fly ash containing CuO + KCl and CuCl2 + KCl, respectively, with increased SO2 injection. According to in situ Cu K-edge and S K-edge X-ray absorption spectroscopy, Cl gas and CuCl2 were generated and then promoted the formation of highly chlorinated aromatics after thermochemical reactions of SO2 gas with the solid-phase CuO + KCl system. In contrast, the decrease in aromatic-Cls in a CuCl2 + KCl system with SO2 gas was caused mainly by the partial sulfation of the Cu. The chemical form of Cu (especially the oxide/chloride ratio) may be a critical factor in controlling the formation of chlorinated aromatics using SO2 gas. PMID:25377729

Fujimori, Takashi; Nishimoto, Yoshihiro; Shiota, Kenji; Takaoka, Masaki

2014-12-01

216

Removal of sulfur dioxide from flue gas using the sludge sodium humate.  

PubMed

This study shows the ability of sodium humate from alkaline treatment sludge on removing sulfur dioxide (SO2) in the simulated flue gas. Experiments were conducted to examine the effect of various operating parameters, like the inlet SO2 concentration or temperature or O2, on the SO2 absorption efficiency and desulfurization time in a lab-scale bubbling reactor. The sludge sodium humate in the supernatant after alkaline sludge treatment shows great performance in SO2 absorption, and such efficiency can be maintained above 98% with 100 mL of this absorption solution at 298 K (flue gas rate of 0.12 m(3)/h). The highest SO2 absorption by 1.63 g SHA-Na is 0.946 mmol in the process, which is translated to 0.037 g SO2 g(-1) SHA-Na. The experimental results indicate that the inlet SO2 concentration slightly influences the SO2 absorption efficiency and significantly influences the desulfurization time. The pH of the absorption solution should be above 3.5 in this process in order to make an effective desulfurization. The products of this process were characterized by Fourier transform infrared spectroscopy and X-ray diffraction. It can be seen that the desulfurization products mainly contain sludge humic acid sediment, which can be used as fertilizer components. PMID:24453875

Zhao, Yu; Hu, Guoxin

2013-01-01

217

The pollution status of sulfur dioxide in major urban areas of Korea between 1989 and 2010  

NASA Astrophysics Data System (ADS)

The pollution status of sulfur dioxide was analyzed using the datasets collected from seven major cities in Korea for the period of 1989-2010. Although there were moderate differences in SO2 levels between the cities, the temporal trends were seen to be rather distinctive between seasons or across the years. The SO2 levels consistently exhibited relative dominance during winter due to the combined effects of domestic heating and meteorological conditions. In contrast, the annual datasets underwent an abrupt decrease until the late 90s. As such, if the data are divided into two periods I (1989-1999) and II (2000-2010), the mean values were reduced considerably from a few tens of ppb (period I) to a few ppb levels (period II). This notable change is suspected to reflect the effect of gradual shift in fuel consumption patterns (e.g., from conventional fuels to cleaner renewal sources of energy). The results of the principal component analysis (PCA) indicated that emissions of SO2 are affected by the incomplete combustion of fossil fuels. According to the health risk assessment, the SO2 exposure to infants and adults should have decreased significantly from period I to period II (e.g., by 5-7 times).

Ray, Sharmila; Kim, Ki-Hyun

2014-10-01

218

Interspecific differences in the effects of sulfur dioxide on angiosperm sexual reproduction  

SciTech Connect

The major objective of this study was to test the potential direct effects of SO/sub 2/ on sexual reproduction in several plant species with different reproductive structures and processes. In marked contrast to the sensitivity to SO/sub 2/ reported by other investigators for pollen germination and pollen tube growth in vitro, and recorded for Lepidium virginicum in this study, 4 of 5 species tested were tolerant with respect to fruit and seed set after exposure to 0.6 ppm SO/sub 2/ for 8 hours during flowering. Seed set in the one sensitive species, Geranium carolinianum, was reduced 40% from the control after exposure to SO/sub 2/, but only when relative humidity (RH) was at or above 90%. The effect of SO/sub 2/ on Lepidium pollen germination in vitro was greater than the effect of SO/sub 2/ on sexual reproduction in vivo. Sulfur dioxide reduced pollen germination in vitro 94% from the control. The same concentration of SO/sub 2/, at 90% Rh, reduced pollen germination in vivo 50% from the control, but had no effect on seed set. Predictions of effects of SO/sub 2/ on reproduction in vivo based on effects of SO/sub 2/ on pollen germination and pollen tube growth in vitro are not valid.

DuBay, D.T.

1981-01-01

219

Influence of relative humidity on direct sulfur dioxide damage to plant sexual reproduction  

SciTech Connect

Results of in vivo experiments with Geranium carolinianum L. showed that sulfur dioxide (SO/sub 2/) damaged sexual reproduction (in terms of decreased seed set) when relative humdity (RH) was 80% or above but not when RH was 70% or below. Relative humidity alone, if 80% or higher, damaged sexual reproduction; the addition of SO/sub 2/ increased the damage. A high SO/sub 2/ dosage of 1.5 ppM/7 hours at 50% RH caused leaf injury, but decreased percent seed set <5%, whereas a low SO/sub 2/ dosage of 0.2 ppM/7 hours at 90% RH decreased percent seed set by 32% without visible leaf injury. At an SO/sub 2/ dosage of 0.4 ppM/7 hours administered during anthesis, percent seed set was virtually identical with the control at 70% RH, 35% below the control at 80% RH, and 68% below the control at 90% RH.

Murdy, W.H.; Ragsdale, H.L.

1980-07-01

220

Temperature and pressure dependence of the electrooptical Kerr effect of sulfur dioxide  

SciTech Connect

Measurements of the electrooptical Kerr effect of sulfur dioxide over a range of temperature ({approx} 299-490 K) and pressure ({approx}45-200 kPa) are reported. Analysis of the temperature dependence of the first Kerr virial coefficient in conjunction with the known mean polarizability and Rayleigh depolarization ratio yields high-precision values of the optical-frequency polarizabilities of the molecule. Results (10{sup 40}{alpha}{sub xx}/C m{sup 2} V{sup {minus}1}, etc., x direction perpendicular to molecular plane, y and z directions in plane, z coincident with C{sub 2} axis) emerge as 3.30 {plus minus} 0.04, 5.80 {plus minus} 0.06, and 3.88 {plus minus} 0.06 at 632.8 nm. The first and second Kerr hyperpolarizabilities make only very small contributions to the Kerr constant so that rather imprecise, but nevertheless valuable, estimates of these two properties are obtained.

Gentle, I.R.; Laver, D.R. (Univ. of Sydney, New South Wales (Australia)); Ritchie, L.D. (Univ. of New England, Armidale, New South Wales (Australia))

1990-05-03

221

Compact, DC-electrical biased sulfur dioxide sensing elements for use at high temperatures  

SciTech Connect

Fabrication and operation of sensing elements for the detection of sulfur dioxide (SO_2) at high temperature (800 900 ^oC) is reported. The sensing elements consisted of three (two oxide and one Pt) electrodes on yttria-stabilized zirconia substrates. To operate the elements, a DC current (typically about 0.1 mA) is driven between two of the electrodes and the voltage between one of these electrodes and the third electrode is used as the sensing signal. These sensing elements respond very strongly to SO_2, for example 2 ppm_V of SO_2 in a background of 7 vol% O_2, balance N_2 was found to produce a >10% change in the sensing signal, which could be easily detected. Sensing elements fabricated to be nominally identical were shown to yield qualitatively identical sensing behavior, and temperature, oxygen content, and flow were all found to strongly impact sensing performance. The impact of interferents, such as NO_x and CO, was evaluated and found to be relatively small in comparison to the SO_2 response. The sensing response, over a 1 month period, was very stable, with the ratio of the average change in sensing signal over one day to the average sensing signal magnitude being about 0.1%.

West, David L [ORNL; Montgomery, Fred C [ORNL; Armstrong, Beth L [ORNL

2012-01-01

222

Exploring the Capabilities of Satellite Observation of Anthropogenic Sulfur Dioxide (SO2) in the Lower Atmosphere  

NASA Astrophysics Data System (ADS)

Anthropogenic activities, such as fuel combustion, oil refining, and metal smelting, emit sulfur dioxide (SO2) into the atmospheric planetary boundary layer (PBL), leading to air quality degradation near the source regions. SO2 in the air is oxidized to form sulfate aerosols, which may have a significant impact on regional air quality and climate. Sulfate aerosols are usually removed from the atmosphere through acid deposition, which can damage the environment and ecosystems. SO2 and sulfate aerosols are sometimes lifted into the middle or upper troposphere and subsequently transported over long distances, affecting remote regions. Space-borne UV instruments, such as Aura/OMI, MetOp/GOME-2, and NPP/OMPS, provide a unique perspective on the spatial and temporal distribution of SO2 over the globe. In this presentation, we will describe the recent advances in retrieval algorithm that provide improved detection and quantification of PBL SO2, and compare the new retrievals with the operational OMI SO2 products to show significant reduction in noise and bias. We will also present validation results obtained by the comparisons with co-located in-situ aircraft measurements to illustrate improved accuracy achieved with the advanced algorithm.

Yang, K.; Krotkov, N. A.; Li, C.; He, H.; Dickerson, R. R.

2012-12-01

223

Estimation of sulfur dioxide air pollution concentrations with a spatial autoregressive model  

NASA Astrophysics Data System (ADS)

In this paper, we develop a land-use regression model for sulfur dioxide air pollution concentrations. We make use of mobile monitoring data collected in Hamilton, Ontario, Canada, between 2005 and 2010 inclusive. The observed SO2 concentrations are regressed against a comprehensive set of land use and transportation variables. Land use and transportation variables are assessed as the amount of each characteristic within buffers of 50, 100, 200, 400, 800, and 1600 m around pollution observation locations. In the first instance of regression modeling, we apply ordinary least-squares regression. The OLS model R2 for training data was 0.38, and an R2 of 0.3 for a 50% held out cross-validation data set. The residuals are spatially correlated with the OLS model as determined with Moran's I. We thus applied a simultaneous autoregressive model, specifically the spatial error model. The resulting model slightly improved fit as determined by a pseudo R2 = 0.4, improved log-likelihood, and reduced MSE, RMSE, and MAE. The spatial error model residuals were not spatially auto-correlated, resulting in a valid model. SAR modeling is a natural extension to OLS regression models and solves the issue of spatial autocorrelation in model residuals with a one-stage model.

Kanaroglou, Pavlos S.; Adams, Matthew D.; De Luca, Patrick F.; Corr, Denis; Sohel, Nazmul

2013-11-01

224

On-Road Motor Vehicle Emissions including Ammonia, Sulfur Dioxide and Nitrogen Dioxide Don Stedman, Gary Bishop, Allison Peddle, University of Denver Department of Chemistry and Biochemistry Denver CO 80208. www.feat.biochem.du.edu  

E-print Network

On-Road Motor Vehicle Emissions including Ammonia, Sulfur Dioxide and Nitrogen Dioxide Don Stedman Year San Jose Fresno West LA Ammonia: Highest emissions in about 15 yr old cars The West LA fleet has as expected from the fuel, older vehicles unexpected interference? Ammonia: Largest % of the NOx

Denver, University of

225

Assessing hazards to aviation from sulfur dioxide emitted by explosive Icelandic eruptions  

NASA Astrophysics Data System (ADS)

eruptions take place in Iceland about once every 3 to 5 years. Ash emissions from these eruptions can cause significant disruption to air traffic over Europe and the North Atlantic as is evident from the 2010 eruption of Eyjafjallajökull. Sulfur dioxide (SO2) is also emitted by volcanoes, but there are no criteria to define when airspace is considered hazardous or nonhazardous. However, SO2 is a well-known ground-level pollutant that can have detrimental effects on human health. We have used the United Kingdom Met Office's NAME (Numerical Atmospheric-dispersion Modelling Environment) model to simulate SO2 mass concentrations that could occur in European and North Atlantic airspace for a range of hypothetical explosive eruptions in Iceland with a probability to occur about once every 3 to 5 years. Model performance was evaluated for the 2010 Eyjafjallajökull summit eruption against SO2 vertical column density retrievals from the Ozone Monitoring Instrument and in situ measurements from the United Kingdom Facility for Airborne Atmospheric Measurements research aircraft. We show that at no time during the 2010 Eyjafjallajökull eruption did SO2 mass concentrations at flight altitudes violate European air quality standards. In contrast, during a hypothetical short-duration explosive eruption similar to Hekla in 2000 (emitting 0.2 Tg of SO2 within 2 h, or an average SO2 release rate 250 times that of Eyjafjallajökull 2010), simulated SO2 concentrations are greater than 1063 µg/m3 for about 48 h in a small area of European and North Atlantic airspace. By calculating the occurrence of aircraft encounters with the volcanic plume of a short-duration eruption, we show that a 15 min or longer exposure of aircraft and passengers to concentrations ?500 µg/m3 has a probability of about 0.1%. Although exposure of humans to such concentrations may lead to irritations to the eyes, nose and, throat and cause increased airway resistance even in healthy individuals, the risk is very low. However, the fact that volcanic ash and sulfur species are not always collocated and that passenger comfort could be compromised might be incentives to provide real-time information on the presence or absence of volcanic SO2. Such information could aid aviation risk management during and after volcanic eruptions.

Schmidt, Anja; Witham, Claire S.; Theys, Nicolas; Richards, Nigel A. D.; Thordarson, Thorvaldur; Szpek, Kate; Feng, Wuhu; Hort, Matthew C.; Woolley, Alan M.; Jones, Andrew R.; Redington, Alison L.; Johnson, Ben T.; Hayward, Chris L.; Carslaw, Kenneth S.

2014-12-01

226

75 FR 81471 - Approval and Promulgation of Air Quality Implementation Plans; Minnesota; Sulfur Dioxide SIP...  

Federal Register 2010, 2011, 2012, 2013, 2014

...including the installation of a new sulfur recovery unit, physical changes...company has installed a new sulfur recovery unit at the facility...altered to represent these new or modified units. Minnesota's permit...authorized Marathon to install a new sulfur recovery unit (SRU) and...

2010-12-28

227

Cell morphological ultrastructural changes in various organs from mice exposed by inhalation to sulfur dioxide.  

PubMed

Sulfur dioxide (SO2) is a common air pollutant, present in low concentrations in the community air as well as in higher concentrations in some workplaces. Our previous studies demonstrated that SO2 can cause oxidative stress and DNA damage to multiple organs of mice. However, there was no direct proof if and how the morphological changes are caused by SO2. In this study, the ultrastructural morphologies of lungs, livers, spleens, testis, brains, hearts, and kidneys from mice exposed by inhalation to SO2 at 28.00 +/- 1.98 and 56.00 +/- 3.11 mg/m3 were observed with electron microscopy. Our results show that (1) type II alveolar cells of lungs in SO2-exposure groups had obvious pathological changes including vacuolation of osmiophilic multilamellar bodies, a decrease in microvilli content and mitochondrial pyknosis or swelling, as well as various changes in the structure of the nucleus and chromatin. Meanwhile obvious changes in the mitochondrial and nuclear compartments, in type II alveolar cells were also observed. (2) A series of pathological changes was discovered in hepatic cells in SO2-exposure groups, such as swelling of the nucleus, dispersion of lipid droplets, degenerated mitochondria, and dilatation of rough endoplasmic reticulum. For mice exposed to SO2 at 56 mg/m3, necrosis of hepatocytes with unclear karyotheca or nearly dissolved karyotheca and decreases in organelles were observed. (3) The numbers of apoptotic splenocytes from mice exposed to SO2 were increased by SO2 inhalation in a dose-dependent manner. (4) In SO2-exposure groups, some of the cerebral cortex neurons, many glial cells and nerve fibers were damaged. (5) Mitochondrial swelling, decrease or disappearance of mitochondria crista, myocardial myofibril disorder, various changes of nucleus and chromatin, intercalated discs dissociation, and endothelium edema caused by SO2 exposure in heart tissues were found. In addition, other effects, such as myofibrillar fragmentation and dissolution, some myocardial cell membranes breach, and inflammatory cell infiltration, were observed in groups exposed to SO2 at 56 mg/m3. (6) SO2 exposure induced serious ultrastructural lesions in renal proximal tubular lining cells; moreover glomeruli and distal tubular lining cells were damaged in a dose-dependent manner. (7) Compared with the control group, the basement membranes, various seminiferous cells, as well as spermatozoa, and Sertoli cells of testes were altered in the SO2-exposure groups in a dose-dependent manner. In the aggregate, these results lead to a conclusion that inhalation of SO2 can cause the ultrastructure cellular damage of multiple organs in mice. Thus, inhalation of sulfur dioxide appears to be not only toxic to the respiratory system, but also a systemic toxin as well. PMID:17497532

Meng, Ziqiang; Liu, Yuxiang

2007-05-01

228

Dimethyl disulfide (DMDS) and dimethyl sulfide (DMS) emissions from biomass burning in Australia  

NASA Astrophysics Data System (ADS)

We identify dimethyl disulfide (DMDS) as the major reduced sulfur-containing gas emitted from bushfires in Australia's Northern Territory. Like dimethyl sulfide (DMS), DMDS is oxidized in the atmosphere to sulfur dioxide (SO2) and methane sulfonic acid (MSA), which are intermediates in the formation of sulfuric acid (H2SO4). The mixing ratios of DMDS and DMS were the highest we have ever detected, with maximum values of 113 and 35 ppbv, respectively, whereas background values were below the detection limit (10 pptv). Molar emission ratios relative to carbon monoxide (CO) were [1.6 +/- 0.1] × 10-5 and [6.2 +/- 0.3] × 10-6, for DMDS and DMS respectively, while molar emission ratios relative to carbon dioxide (CO2) were [4.7 +/- 0.4] × 10-6 and [1.4 +/- 0.4] × 10-7, respectively. Assuming these observations are representative of biomass burning, we estimate that biomass burning could yield up to 175 Gg/yr of DMDS (119 Gg S/yr) and 13 Gg/yr of DMS.

Meinardi, Simone; Simpson, Isobel J.; Blake, Nicola J.; Blake, Donald R.; Rowland, F. Sherwood

2003-05-01

229

Sulfur Dioxide Plume During the Continuing Eruption of Mt. Etna, Italy  

NASA Technical Reports Server (NTRS)

The current eruption of Mt. Etna started on July 17, and has continued to the present. This ASTER image was acquired on Sunday, July 29 and shows the sulfur dioxide plume (in purple) originating form the summit, drifting over the city of Catania, and continuing over the Ionian Sea. ASTER's unique combination of multiple thermal infrared channels and high spatial resolution allows the determination of the thickness and position of the SO2 plume. The image covers an area of 24 x 30 km.

The image is centered at 37.7 degrees north latitude, 15 degrees east longitude.

Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface.

The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping and monitoring dynamic conditions and temporal change. Examples of applications include monitoring glacial advances and retreats, potentially active volcanoes, thermal pollution, and coral reef degradation; identifying crop stress; determining cloud morphology and physical properties; evaluating wetlands; mapping surface temperature of soils and geology; and measuring surface heat balance.

2001-01-01

230

Foliage responses of spruce trees to long-term low-grade sulfur dioxide deposition.  

PubMed

Foliage on spruce trees (Picea rubens Sarg.) growing on dry SO(2) deposition zones (dry SO(2) deposition ranging from 0.5 and 8.5 S kg ha(-1) year(-1)) downwind from a SO(2) emission source was analyzed to assess chronic effects of long-term low-grade SO(2) deposition on net photosynthesis, stomatal conductance, dark respiration, stomatal antechamber wax structures, elemental concentrations in and on foliage (bulk and surficial concentrations), and types of epiphytic fungi that reside in the phylloplane. Elemental distributions on stomatal antechambers, on fungal colonies, and on smooth surfaces between stomates and fungus colonies were determined with a scanning electronic microscope (SEM) by way of X-ray scanning. It was found that net photosynthesis of newly developed spruce foliage (current-year, and 1-year-old) was not significantly affected by the local SO(2) deposition rates. Sulfur dioxide deposition, however, may have contributed to the gradual decrease in net photosynthesis with increasing needle age. Dark respiration rates were significantly higher on foliage taken from high SO(2) deposition zones. Stomatal rod-web structures deteriorated to flakes with increasing needle age and increasing SO(2) deposition. Further inspection of the needle surfaces revealed an increasing abundance of fungal colonies with increasing needle age. Many fungal taxa were isolated and identified. It was found that black yeasts responded positively, and Xylohypha pinicola responded negatively to high rates of SO(2) deposition. Surficial concentrations of elements such as P, S, K, Cl, Ca were about 10 times higher on fungal colonies than on smooth needle surfaces. Surficial Ca contents on 4 or 5-year-old needles decreased with increasing SO(2) deposition, but surficial S concentrations remained the same. In contrast, bulk foliar Ca and S concentrations increased with increasing SO(2) deposition. PMID:15091479

Meng, F R; Bourque, C P; Belczewski, R F; Whitney, N J; Arp, P A

1995-01-01

231

Sulfur dioxide attenuates LPS-induced acute lung injury via enhancing polymorphonuclear neutrophil apoptosis  

PubMed Central

Aim: We speculated that the enhanced apoptosis of polymorphonuclear neutrophil (PMN) might be responsible for the inhibition of PMN infiltration in the lung. This study was designed to investigate the effects of sulfur dioxide (SO2) on PMN apoptosis in vivo and in vitro, which may mediate the protective action of SO2 on pulmonary diseases. Methods: Acute lung injury (ALI) was induced by intratracheally instillation of lipopolysaccharide (LPS, 100 ?g/100 g, in 200 ?L saline) in adult male SD rats. SO2 solution (25 ?mol/kg) was administered intraperitoneally 30 min before LPS treatment. The rats were killed 6 h after LPS treatment. Lung tissues were collected for histopathologic study and SO2 concentration assay. Bronchoalveolar lavage fluid (BALF) was collected for the measurement of PMN apoptosis. For in vitro experiments, rat peripheral blood PMNs were cultured and treated with LPS (30 mg/L) and SO2 (10, 20 and 30 ?mol/L) for 6 h, and apoptosis-related protein expression was detected by Western blotting, and apoptosis rate was measured with flow cytometry. Results: LPS treatment significantly reduced the SO2 concentrations in the lung tissue and peripheral blood, as compared with the control group. Pretreatment with SO2 prevented LPS-induced reduction of the SO2 concentration in the lung tissue and peripheral blood. LPS treatment significantly reduced PMN apoptosis both in vivo and in vitro, which could be prevented by the pretreatment with SO2. The protein levels of Caspase-3 and Bax was significantly increased, but Bcl-2 was decreased by the pretreatment with SO2, as compared with LPS administration alone. Conclusion: SO2 plays an important role as the modulator of PMN apoptosis during LPS-induced ALI, which might be one of the mechanisms underlying the protective action of SO2 on pulmonary diseases. PMID:22796764

Ma, Hui-jie; Huang, Xin-li; Liu, Yan; Fan, Ya-min

2012-01-01

232

Advances in the Validation of Satellite-Based Maps of Volcanic Sulfur Dioxide Plumes  

NASA Astrophysics Data System (ADS)

The monitoring of volcanic gas emissions with gas cameras, spectrometer arrays, tethersondes, and UAVs presents new opportunities for the validation of satellite-based retrievals of gas concentrations. Gas cameras and spectrometer arrays provide instantaneous observations of the gas burden, or concentration along an optical path, over broad sections of a plume, similar to the observations acquired by nadir-viewing satellites. Tethersondes and UAVs provide us with direct measurements of the vertical profiles of gas concentrations within plumes. This presentation will focus on our current efforts to validate ASTER-based maps of sulfur dioxide plumes at Turrialba and Kilauea Volcanoes (located in Costa Rica and Hawaii, respectively). These volcanoes, which are the subjects of comprehensive monitoring programs, are challenging targets for thermal infrared (TIR) remote sensing due the warm and humid atmospheric conditions. The high spatial resolution of ASTER in the TIR (90 meters) allows us to map the plumes back to their source vents, but also requires us to pay close attention to the temperature and emissivity of the surfaces beneath the plumes. Our knowledge of the surface and atmospheric conditions is never perfect, and we employ interactive mapping techniques that allow us to evaluate the impact of these uncertainties on our estimates of plume composition. To accomplish this interactive mapping we have developed the Plume Tracker tool kit, which integrates retrieval procedures, visualization tools, and a customized version of the MODTRAN radiative transfer (RT) model under a single graphics user interface (GUI). We are in the process of porting the RT calculations to graphics processing units (GPUs) with the goal of achieving a 100-fold increase in the speed of computation relative to conventional CPU-based processing. We will report on our progress with this evolution of Plume Tracker. Portions of this research were conducted at the Jet Propulsion Laboratory, California Institute of Technology, under contract to the National Aeronautics and Space Administration.

Realmuto, V. J.; Berk, A.; Acharya, P. K.; Kennett, R.

2013-12-01

233

Evaluation of GEOS-5 Sulfur Dioxide Simulations During the Frostburg, MD 2010 Field Campaign.  

NASA Technical Reports Server (NTRS)

Sulfur dioxide (SO2) is a major atmospheric pollutant with a strong anthropogenic component mostly produced by the combustion of fossil fuel and other industrial activities. As a precursor of sulfate aerosols that affect climate, air quality, and human health, this gas needs to be monitored on a global scale. Global climate and chemistry models including aerosol processes along with their radiative effects are important tools for climate and air quality research. Validation of these models against in-situ and satellite measurements is essential to ascertain the credibility of these models and to guide model improvements. In this study the Goddard Chemistry, Aerosol, Radiation, and Transport (GOCART) module running on-line inside the Goddard Earth Observing System version 5 (GEOS-5) model is used to simulate aerosol and SO2 concentrations. Data taken in November 2010 over Frostburg, Maryland during an SO2 field campaign involving ground instrumentation and aircraft are used to evaluate GEOS-5 simulated SO2 concentrations. Preliminary data analysis indicated the model overestimated surface SO2 concentration, which motivated the examination of mixing processes in the model and the specification of SO2 anthropogenic emission rates. As a result of this analysis, a revision of anthropogenic emission inventories in GEOS-5 was implemented, and the vertical placement of SO2 sources was updated. Results show that these revisions improve the model agreement with observations locally and in regions outside the area of this field campaign. In particular, we use the ground-based measurements collected by the United States Environmental Protection Agency (US EPA) for the year 2010 to evaluate the revised model simulations over North America.

Buchard, V.; Da Silva, A. M.; Colarco, P.; Krotkov, N.; Dickerson, R. R.; Stehr, J. W.; Mount, G.; Spenei, E.; Arkinson, H. L.; He, H.

2013-01-01

234

Ultraviolet optical model of volcanic clouds for remote sensing of ash and sulfur dioxide  

NASA Astrophysics Data System (ADS)

The total ozone mapping spectrometer (TOMS) instruments have detected every significant volcanic eruption from November 1978 to December 1994 on the Nimbus 7 and Meteor 3 satellites and since July 1996 on the new satellites, TOMS-Earth Probe and ADEOS. We apply a radiative transfer model to simulate the albedos of these fresh eruption clouds to study the limitations of the present algorithm which assumes an absorbing cloud above a scattering atmosphere. The conditions are found to be approximated when the total absorption optical depth is less than 2 (i.e., 100 Dobson units (DU) SO2 at 312 nm or 300 DU SO2 at 317 nm). The spectral dependence of the albedo of a nonabsorbing Rayleigh atmosphere can be specified by only two parameters which are uniquely different when ash or sulfate aerosols are present in the stratosphere. However, the interaction between ash scattering and SO2 absorption within a volcanic cloud produces a nonlinear effect at strongly absorbing wavelengths that accounts for overestimation of sulfur dioxide in ash-laden volcanic clouds by the Krueger et al. [1995] algorithm. Correction of this error requires knowledge of the ash properties. A method for determining two of the ash parameters from the longer TOMS wavelengths is described. Given the altitude of the cloud, surface reflectivity, and an estimate of effective variance of the ash size distribution, the optical thickness and either the effective radius or the index of refraction can be deduced. The ash retrievals are also needed to evaluate the tephra/gas ratio of eruptions and to compare the ash properties of different volcanoes.

Krotkov, N. A.; Krueger, A. J.; Bhartia, P. K.

1997-09-01

235

Differences in airway reactivity in normal and allergic sheep after exposure to sulfur dioxide  

SciTech Connect

The effect of breathing 5 ppm sulfur dioxide (SO/sub 2/) on airway reactivity was studied in both normal and allergic conscious sheep. Allergic sheep were defined as animals in which inhalation of Axcaris suum extract resulted in bronchospasm as evidenced by an increase in mean pulmonary flow resistance (RL), hyperinflation, and a fall in dynamic compliance. Airway reactivity was assessed by measuring the increase of RL after 18 breaths of 0.25% carbachol (c), from an initial RL value obtained after 18 breaths of buffered saline (s) (RL(c-s)). RL and RL(c-s) were determined prior to, immediately after, and 24 h after exposure to 5 ppm SO/sub 2/ for 4 h. In both groups RL remained unchanged after SO/sub 2/ exposure. Prior to exposure, RL(c-s) was not significantly different in seven normal (0.3 +/- 0.1) and seven allergic sheep (0.4 +/- 0.2 (SD) cmH/sub 2/O.l/sup -1/.s), and there was no significant change in RL (c-s) immediately after SO/sub 2/ exposure in either group. Twenty-four h later, RL(c-s) RL(c-s) increased to 0.7 +/- 0.8 (P < 0.2) in normal and to 1.8 +/- 0.9 cmH/sub 2/O.l/sup -1/.s (P < 0.01) in allergic sheep. Because the increase in RL(c-s) after 24 h was greater (P < 0.01) in allergic than in normal sheep, we conclude that SO/sub 2/ exposure increased airway reactivity more in the former than in the latter.

Abraham, W.M.; Oliver, W. Jr.; Welker, M.J.; King, M.M.; Wanner, A.; Sackner, M.A.

1981-12-01

236

Trends and effectiveness of emission control of sulfur dioxide in China: a satellite perspective  

NASA Astrophysics Data System (ADS)

The combination of two satellite instruments (OMI and SCIAMACHY) provides high quality space-borne measurements for the trend analysis of sulfur dioxide (SO2) column density. An improved product of SO2 retrievals from these two satellites was derived with the consistent local air mass factor (AMF) algorithm which converts the line-of-sight 'slant' columns to vertical columns for the period of 2003-2010. The local AMF was calculated using altitude-dependent scattering weights computed from a radiative transfer model (LIDORT) with state-of-art a priori parameters, weighted by relative vertical SO2 profiles (shape factor) determined locally with a global atmospheric chemical model (GEOS-Chem). The derived vertical columns and modeled vertical SO2 profiles were compared to measurements from aircraft campaigns in China. Trends of the long-term SO2 columns showed discrepancies between different regions in China: SO2 columns increased fast during 2003-2007 and then decreased by ~30% in 2010 in North China Plain; continuous increase of SO2 columns were found in Southwest of China with only a slight decrease in 2008 due to the global economic recession. The trends of SO2 columns were further compared to a unit-based power plant emission inventory to evaluate the effectiveness of power plant SO2 emission reductions related to the wide-spread installations of flue-gas desulfurization (FGD) devices since 2005 in China. The combinations of NO2 and SO2 measurements were used to examine the operation and efficiency of the FGD devices in power plants.

Zhang, Q.; Wang, S.; Martin, R. V.; He, K.; Richter, A.; Krotkov, N. A.; Philip, S.; Wang, T.

2011-12-01

237

Separation of ash and sulfur dioxide during the 2011 Grķmsvötn eruption  

NASA Astrophysics Data System (ADS)

the transport of volcanic ash and gases released during volcanic eruptions is crucially dependent on knowledge of the source term of the eruption, that is, the source strength as a function of altitude and time. For the first time, an inversion method is used to estimate the source terms of both volcanic sulfur dioxide (SO2) and ash. It was applied to the explosive volcanic eruption of Grķmsvötn, Iceland, in May 2011. The method uses input from the particle dispersion model, FLEXPART (flexible particle dispersion model), a priori source estimates, and satellite observations of SO2 or ash total columns from Infrared Atmospheric Sounding Interferometer to separately obtain the source terms for volcanic SO2 and fine ash. The estimated source terms show that SO2 was emitted mostly to high altitudes (5 to 13 km) during about 18 h (22 May, 00-18 UTC) while fine ash was emitted mostly to low altitudes (below 4 km) during roughly 24 h (22 May 06 UTC to 23 May 06 UTC). FLEXPART simulations using the estimated source terms show a clear separation of SO2 (transported mostly northwestward) and the fine ash (transported mostly southeastward). This corresponds well with independent satellite observations and measured aerosol mass concentrations and lidar measurements at surface stations in Scandinavia. Aircraft measurements above Iceland and Germany confirmed that the ash was located in the lower atmosphere. This demonstrates that the inversion method, in this case, is able to distinguish between emission heights of SO2 and ash and can capture resulting differences in transport patterns.

Moxnes, E. D.; Kristiansen, N. I.; Stohl, A.; Clarisse, L.; Durant, A.; Weber, K.; Vogel, A.

2014-06-01

238

Evaluation of sulfur dioxide emissions from explosive volcanism: the 1982-1983 eruptions of Galunggung, Java, Indonesia  

USGS Publications Warehouse

Galunggung volcano, Java, awoke from a 63-year quiescence in April 1982, and erupted sporadically through January 1983. During its most violent period from April to October, the Cikasasah Volcano Observatory reported 32 large and 56 moderate to small eruptions. From April 5 through September 19 the Total Ozone Mapping Spectrometer (TOMS), carried on NASA's Nimbus-7 satellite, detected and measured 24 different sulfur dioxide clouds; an estimated 1730 kilotons (kt) of SO2 were outgassed by these explosive eruptions. The trajectories, and rapid dispersion rates, of the SO2 clouds were consistent with injection altitudes below the tropopause. An additional 300 kt of SO2 were estimated to have come from 64 smaller explosive eruptions, based on the detection limit of the TOMS instrument. For the first time, an extended period of volcanic activity was monitored by remote sensing techniques which enabled observations of both the entire SO2 clouds produced by large explosive eruptions (using TOMS), and the relatively lower levels of SO2 emissions during non-explosive outgassing (using the Correlation Spectrometer, or COSPEC). Based on COSPEC measurements from August 1982 to January 1983, and on the relationship between explosive and non-explosive degassing, approximately 400 kt of SO2 were emitted during non-explosive activity. The total sulfur dioxide outgassed from Galunggung volcano from April 1982 to January 1983 is calculated to be 2500 kt (?? 30%) from both explosive and non-explosive activity. While Galunggung added large quantities of sulfur dioxide to the atmosphere, its sporadic emissions occurred in relatively small events distributed over several months, and reached relatively low altitudes, and are unlikely to have significantly affected aerosol loading of the stratosphere in 1982 by volcanic activity. ?? 1994.

Bluth, G.J.S.; Casadevall, T.J.; Schnetzler, C.C.; Doiron, S.D.; Walter, L.S.; Krueger, A.J.; Badruddin, M.

1994-01-01

239

Chemical recycling of carbon dioxide to methanol and dimethyl ether: from greenhouse gas to renewable, environmentally carbon neutral fuels and synthetic hydrocarbons.  

PubMed

Nature's photosynthesis uses the sun's energy with chlorophyll in plants as a catalyst to recycle carbon dioxide and water into new plant life. Only given sufficient geological time can new fossil fuels be formed naturally. In contrast, chemical recycling of carbon dioxide from natural and industrial sources as well as varied human activities or even from the air itself to methanol or dimethyl ether (DME) and their varied products can be achieved via its capture and subsequent reductive hydrogenative conversion. The present Perspective reviews this new approach and our research in the field over the last 15 years. Carbon recycling represents a significant aspect of our proposed Methanol Economy. Any available energy source (alternative energies such as solar, wind, geothermal, and atomic energy) can be used for the production of needed hydrogen and chemical conversion of CO(2). Improved new methods for the efficient reductive conversion of CO(2) to methanol and/or DME that we have developed include bireforming with methane and ways of catalytic or electrochemical conversions. Liquid methanol is preferable to highly volatile and potentially explosive hydrogen for energy storage and transportation. Together with the derived DME, they are excellent transportation fuels for internal combustion engines (ICE) and fuel cells as well as convenient starting materials for synthetic hydrocarbons and their varied products. Carbon dioxide thus can be chemically transformed from a detrimental greenhouse gas causing global warming into a valuable, renewable and inexhaustible carbon source of the future allowing environmentally neutral use of carbon fuels and derived hydrocarbon products. PMID:19063591

Olah, George A; Goeppert, Alain; Prakash, G K Surya

2009-01-16

240

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

SciTech Connect

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

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

1990-08-01

241

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

SciTech Connect

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

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

1990-08-01

242

Ecological effects of sulfur dioxide, fluorides, and minor air pollutants: recent trends and research needs.  

PubMed

The regulation of the emissions of 'traditional' primary air pollutants (fluorides, sulfur dioxide) has changed the pattern of exposure of ecological systems, with greatly reduced exposure close to sources, but with a smaller effect in some remote areas. Measurements show that recovery is occurring at some sites, in fresh water chemistry (reduced acidity) and in sensitive biota (sustainable fish populations). However, the pattern of change in exposure has not always been simply related to emission reductions. An understanding of responses to recent changes will improve our predictions of the response to future emission changes, both locally and globally. As exposure to 'traditional' pollutants is reduced, the potential for other pollutants to have effects becomes more evident. In the aqueous phase, we need to understand the role of soluble and suspended organics, but this also means explicit recognition of the possibility of phase exchange, and the role of photolytic reactions on plant, soil, and water surfaces. Do highly reactive free radicals in the atmosphere, formed by the action of sunlight on volatile organic compounds, have direct effects on plants? Organic compounds and heavy metals may be bioactive as gases and particles, but for many potentially toxic compounds, the experimental evidence for biotic response is very limited. To evaluate the potential effects of pollutants, we need to understand the pathways by which airborne pollutants enter and react within ecosystems. For vegetation, we have to consider bidirectional fluxes, and distinguish among uptake through stomata, through leaf surfaces, or through roots. There are several challenges for the future. (1) Can we devise experiments that permit exposure of vegetation to gases, particles, and/or aqueous pollutants at 'realistic' concentrations? (2) Can we include the potential interactions with photolytically derived free radicals, and the dynamics of exchange? (3) How do we allow for responses to pollutant mixtures, or the simultaneous exposure to pollutants in gas, particle, and aqueous phases? The recognition of the importance of the dynamic exchange of pollutants between phases will be the key to the development of effective experimental approaches to evaluating cause-effect relationships between pollutant mixtures and ecosystem responses. PMID:12676208

Cape, J Neil; Fowler, David; Davison, Alan

2003-06-01

243

Evaluation of Redoubt Volcano's sulfur dioxide emissions by the Ozone Monitoring Instrument  

NASA Astrophysics Data System (ADS)

The 2009 eruption of Redoubt Volcano, Alaska, provided a rare opportunity to compare satellite measurements of sulfur dioxide (SO2) by the Ozone Monitoring Instrument (OMI) with airborne SO2 measurements by the Alaska Volcano Observatory (AVO). Herein we: (1) compare OMI and airborne SO2 column density values for Redoubt's tropospheric plume, (2) calculate daily SO2 masses from Mount Redoubt for the first three months of the eruption, (3) develop simple methods to convert daily measured SO2 masses into emission rates to allow satellite data to be directly integrated with the airborne SO2 emissions dataset, (4) calculate cumulative SO2 emissions from the eruption, and (5) evaluate OMI as a monitoring tool for high-latitude degassing volcanoes. A linear correlation (R2 ~ 0.75) is observed between OMI and airborne SO2 column densities. OMI daily SO2 masses for the sample period ranged from ~ 60.1 kt on 24 March to below detection limit, with an average daily SO2 mass of ~ 6.7 kt. The highest SO2 emissions were observed during the initial part of the explosive phase and the emissions exhibited an overall decreasing trend with time. OMI SO2 emission rates were derived using three methods and compared to airborne measurements. This comparison yields a linear correlation (R2 ~ 0.82) with OMI-derived emission rates consistently lower than airborne measurements. The comparison results suggest that OMI's detection limit for high latitude, springtime conditions varies from ~ 2000 to 4000 t/d. Cumulative SO2 masses calculated from daily OMI data for the sample period are estimated to range from 542 to 615 kt, with approximately half of this SO2 produced during the explosive phase of the eruption. These cumulative masses are similar in magnitude to those estimated for the 1989-90 Redoubt eruption. Strong correlations between daily OMI SO2 mass and both tephra mass and acoustic energy during the explosive phase of the eruption suggest that OMI data may be used to infer relative eruption size and explosivity. Further, when used in conjunction with complementary datasets, OMI daily SO2 masses may be used to help distinguish explosive from effusive activity and identify changes in lava extrusion rates. The results of this study suggest that OMI is a useful volcano monitoring tool to complement airborne measurements, capture explosive SO2 emissions, and provide high temporal resolution SO2 emissions data that can be used with interdisciplinary datasets to illuminate volcanic processes.

Lopez, Taryn; Carn, Simon; Werner, Cynthia; Fee, David; Kelly, Peter; Doukas, Michael; Pfeffer, Melissa; Webley, Peter; Cahill, Catherine; Schneider, David

2013-06-01

244

On the Separation of Ash and Sulfur Dioxide in Volcanic Clouds  

NASA Astrophysics Data System (ADS)

Detection and tracking of the hazardous components present in erupting and drifting volcanic clouds (chiefly ash and sulfur dioxide, SO2) is of major importance to airborne hazard mitigation. Satellite observations made by ultraviolet (TOMS) and thermal infrared (AVHRR, GOES, GMS, MODIS) sensors over the past few decades have revealed that ash and SO2 often exhibit a vertical separation in the volcanic clouds produced by explosive eruptions, typically with the SO2-rich portion at higher altitude. Windshear causes the ash and SO2 to follow different trajectories in the atmosphere thus producing further separation of the two components in a horizontal sense. TOMS is well suited to the study of this phenomenon since it is capable of detecting ash and SO2 simultaneously at all stages of an eruption during daylight hours, whereas infrared (IR) detection algorithms fail when clouds are opaque. However, IR sensors have higher spatial and temporal resolution than TOMS, which can only resolve separations in excess of ~40-50 km once per day in mid-latitudes. Proposed mechanisms to account for ash- SO2 separation include density-driven sedimentation of ash [Holasek et al., 1996, JVGR, 70:169-181], preferential scavenging of SO2 at lower levels of volcanic clouds [Rose et al., 1995, Nature, 375:477-479] or a pre-eruptive stratification of the magmatic system, with a cupola of gas-rich magma situated between the volcanic vent and the magma chamber [Giggenbach, 1990, JVGR, 42:13-40; Wallace, 2001, JVGR, 108:85-106]. Eruptions known to have exhibited separation of ash and SO2 include Mt St Helens (1980), El Chich\\?{o}n (1982), Galunggung (1982), Lopevi (1982), Colo (1983), Ruiz (1985), Kliuchevskoi (1990), Pinatubo (1991), Hudson (1991), Lascar (1993), Soufriere Hills (1997, 1999), Shishaldin (1999) and Miyakejima (2000). These eruptions encompass a range of atmospheric conditions, volcano types and eruption magnitudes. Clearly the timing of the satellite image in relation to the eruptive event is a critical factor in assessing the contribution of the mechanisms listed above to the observed ash-SO2 distribution, particularly when density-driven sedimentation is involved. An `instantaneous' phase separation at the time of eruption may support the theory of pre-eruptive stratification, but this is also the time when eruption clouds are least dispersed and thus difficult to resolve in satellite imagery. We will examine the many documented examples of ash-SO2 separation and assess the potential contributory factors on a case-by-case basis.

Carn, S. A.; Schneider, D. J.; Bluth, G. J.; Kobs, S. E.; Rose, W. I.; Ernst, G. G.

2002-05-01

245

Sulfur mass-independent fractionation patterns in the broadband UV photolysis of sulfur dioxide: Pressure and third body effects  

NASA Astrophysics Data System (ADS)

The production of mass-independent fractionation (MIF) in the products of the middle/far UV photolysis of SO 2 isotopologues has been linked to large S-MIF signatures observed in the pre-2.45 Ga rock record, and provides a valuable proxy for the evolution of atmospheric O 2. The origin of such large MIF signatures in photolytic products has recently been ascribed to the optical self-shielding of SO 2 isotopologues in photon-limited regions of the lower atmosphere. To better characterize the origin of such a signal we have performed pressure-variant broadband UV photolysis experiments of SO 2 and SO 2-He mixtures. Low pressure (~ 20 Torr) photolysis of SO 2 produces extractable sulfur with large ? 34S ? 120-180‰, ? 33S ~ 20‰, and ? 36S/? 33S ? - 2.5, while near atmospheric pressures produce sulfur with ? 33S ~ 2‰, and ? 36S/? 33S ? - 12. Similar experiments conducted with variable pressures of helium bath gas produce a similar diminution in ? 33S, and in both cases a ? 36S/? 33S ratio that is a linear function of pressure over several orders of magnitude. We postulate a photochemical and kinetic origin for the large S-MIF observed in these static cell experiments, produced from the excited state predissociative dynamics of SO 2, but cannot expressly rule out self-shielding as a contributor to fractionations observed here.

Masterson, Andrew L.; Farquhar, James; Wing, Boswell A.

2011-06-01

246

Alteration of extracellular enzymes in pinto bean leaves upon exposure to air pollutants, ozone and sulfur dioxide  

SciTech Connect

Diamine oxidase and peroxidase, associated with the wall in pinto bean (Phaseolus vulgaris L. var Pinto) leaves, can be washed out by vacuum infiltration and assayed without grinding the leaf. The diamine oxidase activity is inhibited in vivo by exposure of the plants to ozone (dose of 0.6 microliters per liter {times} hour), whereas the peroxidase activity associated with the wall space is stimulated. This dose does not cause obvious necrosis or chlorosis of the leaf. These alterations are greater when the dose of ozone exposure is given as a triangular pulse (a slow rise to a peak of 0.24 microliters per liter followed by a slow fall) compared to that given as a constant square wave pulse of 0.15 microliters per liter for the same 4 hour period. Exposure of the plants to sulfur dioxide (at a concentration of 0.4 microliters per liter for 4 hours) does not result in any change in the diamine oxidase or peroxidase activities, yet the total sulfhydryl content of the leaf is increased, demonstrating the entry of sulfur dioxide. These two pollutants, with different chemical reactivities, affect the activities of the extracellular enzymes in different manners. In the case of ozone exposure, the inhibition of extracellular diamine oxidase could profoundly alter the movements of polyamines from cell to cell.

Peters, J.L.; Castillo, F.J.; Heath, R.L. (Univ. of California, Riverside (USA))

1989-01-01

247

Relaxed eddy accumulation measurements of ammonia, nitric acid, sulfur dioxide and particulate sulfate dry deposition near Tampa, FL, USA  

NASA Astrophysics Data System (ADS)

The relaxed eddy accumulation (REA) method was utilized to measure fluxes of key atmospheric species, specifically ammonia (NH3), nitric acid (HNO3), sulfur dioxide (SO2) and particulate sulfate (SO42-) to vegetation that is characteristic throughout the Tampa Bay Watershed. Three annular denuder systems (ADS), each consisting of two annular denuders and a filter pack in series, were deployed to accumulate gaseous constituents and fine-fraction particulates (Dp<2.5 µm) in updraft and downdraft eddies, as well as in the mid-draft velocity range. Relaxed eddy accumulation samples, which were analyzed by ion chromatography, and continuous meteorological data were collected during the May 2002 Bay Regional Atmospheric Chemistry Experiment (BRACE) near Sydney, FL. For the chemical species of current interest, concentrations were 1.64 ± 0.23 for NH3, 2.06 ± 0.24 for HNO3, 3.49 ± 0.50 for SO2 and 4.64 ± 0.31 µg m-3 for SO42-, and the deposition velocity (Vd) estimates for NH3, HNO3, SO2 and SO42- were 1.27 ± 3.65, 3.63 ± 1.47, 0.45 ± 0.98 and 0.42 ± 1.00 cm s-1, respectively. The results obtained confirm the expectation that the deposition of ammonia, nitric acid and particulate sulfate was controlled by aerodynamic and quasi-laminar layer resistances and that sulfur dioxide is relatively dependent upon stomatal conditions.

Toya Myles, La; Meyers, Tilden P.; Robinson, Larry

2007-07-01

248

40 CFR 60.45b - Compliance and performance test methods and procedures for sulfur dioxide.  

Code of Federal Regulations, 2010 CFR

...Facilities burning coke oven gas alone or in combination...fuel sampling and analysis procedures in Method...fuel sampling and analysis procedures in Method...sulfur oil, natural gas, or a mixture...fuel sampling and analysis procedures...

2010-07-01

249

A Demonstration of Acid Rain and Lake Acidification: Wet Deposition of Sulfur Dioxide.  

ERIC Educational Resources Information Center

Introduces a science demonstration on the dissolution of sulfuric oxide emphasizing the concept of acid rain which is an environmental problem. Demonstrates the acidification from acid rain on two lake environments, limestone and granite. Includes safety information. (YDS)

Goss, Lisa M.

2003-01-01

250

Sulfur dioxide estimations in the planetary boundary layer using dispersion models and satellite retrievals  

NASA Astrophysics Data System (ADS)

The health and environmental conditions in the Central Andes city La Oroya, Peru, have been seriously damaged by the heavy metal mining activities in the region. The situation has been exacerbated by the complex topography, which prevents proper mixing and dissolution of particles and gases released into the atmosphere. Understanding how pollutants are dispersed in populated regions, especially in complex terrain, would help to create mitigation strategies. The present study uses CALPUFF and HYSPLIT dispersion/deposition models to estimate sulfur dioxide (SO2) dispersion from the main stack of the La Oroya metallurgical plant. Due to the lack of meteorological data in the area, the Weather Research and Forecasting model (WRF) is used with observational nudging for temperature, relative humidity, and wind fields of three surface meteorological stations specifically installed for the study. The pollutant dispersion models are sensitive to a precise estimation of the turbulent vertical transport of mass, energy and moisture in the low atmosphere; therefore, two planetary boundary layer (PBL) schemes are tested, the Mellor-Yamada-Janjic and Yonsei University models. The dispersion models are run and results compared with field measurements at La Oroya, and Huancayo. The observation-nudging and YSU scheme considerably improved the prognostic variables. CALPUFF and HYSPLIT models showed similar patterns; however, HYSPLIT overestimated SO2 concentrations for low PBLs. Moreover, recent enhancements on spectral, spatial and temporal resolution of atmospheric scanning sensors of chemical constituents from the space, have led to detecting trace gases of anthropogenic origin in the lower troposphere. This contribution also explores the SO2 level 2 dataset from Ozone Mapping Instrument (OMI), in conjunction with atmospheric optical depth and Angstrom coefficient data products, extracted from MODerate Resolution Imaging Spectroradiometer (MODIS) to estimate SO2 loads in the PBL for clear and turbid atmospheric conditions. A narrow temporal sampling (three days) with no clear atmospheres and best sensor viewing geometry are examined and compared with a pollutant dispersion and deposition model (CALPUFF) and field observations. The efficacy of the developed method is further examined incorporating synchronous wind vectors, and daily accumulated precipitation derived from Tropical Rainfall Measuring Mission (TRMM) data. The source and trajectories of SO2 concentrations are detected by satellite based observations, and the pollutant plume is correctly traced downwind. Then, the spatial patterns of SO2 loads are analyzed for clear atmospheres and optimal viewing conditions (for 55 samples found in 467 days) and compared with field measurements. A logarithmic model is found between in situ observations and OMI estimations. The correlation can be increased when Angstrom exponents are between 0.7 and 1 and a linear relationship obtained when very high SO2 loads are extracted. Results show that the spatio-temporal dynamics of SO2 as monitored from space is in agreement with both field measurements and CALPUFF, which takes into account topography and wind field patterns. The study concludes that anthropogenic pollutants, i.e., SO2, and its trajectory can be monitored from OMI sensor even for turbid sky conditions. Findings of the research have great potential in public health managements and predictions.

Zarauz, Jorge V.

251

Laboratory Measurments of the 3.7-20 cm Wavelength Opacity of Sulfur Dioxide and Carbon Dioxide under Simulated Conditions for the Deep Atmosphere of Venus  

NASA Astrophysics Data System (ADS)

In the past two decades, multiple observations of Venus have been made at X band (3.6 cm) using the Jansky Very Large Array (VLA) and maps have been created of the 3.6 cm emission from Venus. Since the emission morphology is related both to surface features and to deep atmospheric absorption from CO2 and SO2 (see, e.g., Butler et al., Icarus 154, 2001), knowledge of the microwave absorption properties of sulfur dioxide in a carbon dioxide atmosphere under conditions for the deep atmosphere of Venus is required for proper interpretation. Except for a single measurement campaign conducted at a single wavelength (3.2 cm) over 40 years ago (Ho et al., JGR 71, 1966), no measurements of the centimeter-wavelength properties of any Venus atmospheric constituent have been conducted under conditions characteristic of the deep atmosphere (pressures from 10-92 Bars and temperatures from 400-700 K). New measurements of the microwave properties of SO2 and CO2 at wavelengths from 3.7-20 cm are now being conducted under simulated conditions for the deep atmosphere of Venus, using a new high-pressure system. Initial results from this measurement campaign conducted at 430 K and at pressures up to 92 Bars will be presented. This work is supported by the NASA Planetary Atmospheres Program under Grant NNX11AD66G.

Steffes, Paul G.; Barisich, C.

2012-10-01

252

Integration of continuous biofumigation with Muscodor albus with pre-cooling fumigation with ozone or sulfur dioxide to control postharvest gray mold of table grapes  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sulfur dioxide (SO2) fumigation controls postharvest decay of commercially stored table grapes. To develop an alternative to SO2, fumigation with up to 10,000 micro-l/l ozone (O3) for up to 2 h was applied to control postharvest gray mold caused by Botrytis cinerea. O3 was effective when grapes were...

253

Quartz-enhanced photoacoustic spectroscopy-based sensor system for sulfur dioxide detection using a CW DFB-QCL  

NASA Astrophysics Data System (ADS)

Sulfur dioxide (SO2) trace gas detection based on quartz-enhanced photoacoustic spectroscopy (QEPAS) using a continuous wave, distributed feedback quantum cascade laser operating at 7.24 ?m was performed. Influence of water vapor addition on monitored QEPAS SO2 signal was also investigated. A normalized noise equivalent absorption coefficient of NNEA (1 ?) = 1.21 × 10-8 cm-1 W Hz-1/2 was obtained for the ? 3 SO2 line centered at 1,380.93 cm-1 when the gas sample was moisturized with 2.3 % H2O. This corresponds to a minimum detection limit (1 ?) of 63 parts per billion by volume for a 1 s lock-in time constant.

Waclawek, J. P.; Lewicki, R.; Moser, H.; Brandstetter, M.; Tittel, F. K.; Lendl, B.

2014-10-01

254

REMOTE SENSING OF SULFUR DIOXIDE EFFECTS ON VEGETATION - PHOTOMETRIC ANALYSIS OF AERIAL PHOTOGRAPHS  

EPA Science Inventory

Spectral reflectances were measured by tri-band densitometry of aerial color-infrared photographs of soybean (Glycine mas fields that had been affected by sulfur dioside (SO2) emissions from large, coal-fired power plants in northwestern Alabama and western Tennessee. The photogr...

255

Reaction mechanism of sulfur dioxide with single crystal cobalt and chromium and CoCrAlY coatings  

NASA Astrophysics Data System (ADS)

The objective of this research was to obtain a basic understanding of the reaction mechanism of sulfur dioxide with cobalt and chromium and to use this understanding to analyze the more complex reaction mechanism of sulfur dioxide with CoCrAlY coatings. A basic premise was that the reaction mechanisms of SO2 with Co and Cr are similar and can be described in two basic steps: SO2 yields 2(O) + (S); and 2(O) + SO2 yields SO4. The first step involves the dissociation of SO2 on the metal surfaces with the resulting formation of sulfides and oxides. In the second step, these oxides provide sites at which additional SO2 can bond to the surface and form sulfates. By using X-ray photoelectron spectroscopy (XPS) to study the reaction of SO2 with oxide-free surfaces of single crystal Co(0001) and Cr(110), these steps were shown to occur. The rates of these reactions were found to be similar for the two metals, and no appreciable difference in activation energies could be determined for the exposure conditions tested. Cluster calculations based on the SCF-X alpha-SW method were used to model the second step of the reaction. The approximate energies of the electrons in a cluster of ten cobalt and two oxygen atoms were calculated, and the electron levels most likely involved in the sulfate formation were identified. Experiments with CoCrAlY coatings showed that sulfates were formed in a manner similar to that described for Co(0001) and Cr(110). It was further demonstrated that as the chromium content increased in the coatings, the formation of cobalt sulfate was reduced; the high-chromium content coating formed sigma phase.

Aprigliano, Louis F.

1987-09-01

256

Catalysts for cleaner combustion of coal, wood and briquettes sulfur dioxide reduction options for low emission sources  

SciTech Connect

Coal fired, low emission sources are a major factor in the air quality problems facing eastern European cities. These sources include: stoker-fired boilers which feed district heating systems and also meet local industrial steam demand, hand-fired boilers which provide heat for one building or a small group of buildings, and masonary tile stoves which heat individual rooms. Global Environmental Systems is marketing through Global Environmental Systems of Polane, Inc. catalysts to improve the combustion of coal, wood or fuel oils in these combustion systems. PCCL-II Combustion Catalysts promotes more complete combustion, reduces or eliminates slag formations, soot, corrosion and some air pollution emissions and is especially effective on high sulfur-high vanadium residual oils. Glo-Klen is a semi-dry powder continuous acting catalyst that is injected directly into the furnace of boilers by operating personnel. It is a multi-purpose catalyst that is a furnace combustion catalyst that saves fuel by increasing combustion efficiency, a cleaner of heat transfer surfaces that saves additional fuel by increasing the absorption of heat, a corrosion-inhibiting catalyst that reduces costly corrosion damage and an air pollution reducing catalyst that reduces air pollution type stack emissions. The reduction of sulfur dioxides from coal or oil-fired boilers of the hand fired stoker design and larger, can be controlled by the induction of the Glo-Klen combustion catalyst and either hydrated lime or pulverized limestone.

Smith, P.V. [Global Environmental Solutions, Inc., Morton Grove, IL (United States)

1995-12-31

257

Silver sulfide nanoparticles sensitized titanium dioxide nanotube arrays synthesized by in situ sulfurization for photocatalytic hydrogen production.  

PubMed

Titanium dioxide (TiO2) nanotube arrays (TNAs) sensitized with silver sulfide (Ag2S) nanoparticles (NPs) were synthesized via facile in situ sulfurization. Metallic silver NPs were first loaded on TNAs through a simple electrodeposition process. The as-prepared Ag/TNAs composites were further treated with a solution of acetonitrile containing sulfur (S8) and dried in vacuum to obtain a new nanocomposite material comprising of TNAs sensitized with Ag2S NPs. In these composite nanostructures, ultrafine Ag2S NPs were well-dispersed and assembled on the exterior and interior walls of the TNAs. Owing to sensitizing with a narrow bandgap material like Ag2S and the homogeneous distribution of the Ag2S NP heterojunction structures over the surface of the TNAs, the synthesized nanocomposite samples exhibited remarkable capability to absorb visible light and showed a significant enhancement in the photocatalytic efficiency of hydrogen generation. Under visible light illumination (100mW/cm(2)), a maximum photoconversion efficiency of 1.21% and the highest hydrogen production rate of 1.13mL/cm(2)h were obtained from the TNA electrodes sensitized with Ag2S NPs. PMID:24183425

Liu, Xu; Liu, Zhongqing; Lu, Jinlin; Wu, Xuelian; Chu, Wei

2014-01-01

258

Laboratory Measurement of the Temperature Dependence of Gaseous Sulfur Dioxide (SO2) Microwave Absorption with Application to the Venus Atmosphere  

NASA Technical Reports Server (NTRS)

High-accuracy laboratory measurements of the temperature dependence of the opacity from gaseous sulfur dioxide (SO2) in a carbon dioxide (CO2) atmosphere at temperatures from 290 to 505 K and at pressures from 1 to 4 atm have been conducted at frequencies of 2.25 GHz (13.3 cm), 8.5 GHz (3.5 cm), and 21.7 GHz (1.4 cm). Based on these absorptivity measurements, a Ben-Reuven (BR) line shape model has been developed that provides a more accurate characterization of the microwave absorption of gaseous S02 in the Venus atmosphere as compared with other formalisms. The developed BR formalism is incorporated into a radiative transfer model. The resulting microwave emission spectrum of Venus is then used to set an upper limit on the disk-averaged abundance of gaseous S02 below the main cloud layer. It is found that gaseous S02 has an upper limit of 150 ppm, which compares well with previous spacecraft in situ measurements and Earth-based radio astronomical observations.

Suleiman, Shady H.; Kolodner, Marc A.; Steffes, Paul G.

1996-01-01

259

Microporous activated carbons prepared from palm shell by thermal activation and their application to sulfur dioxide adsorption.  

PubMed

Textural characterization of activated carbons prepared from palm shell by thermal activation with carbon dioxide (CO(2)) gas is reported in this paper. Palm shell (endocarp) is an abundant agricultural solid waste from palm-oil processing mills in many tropical countries such as Malaysia, Indonesia, and Thailand. The effects of activation temperature on the textural properties of the palm-shell activated carbons, namely specific surface area (BET method), porosity, and microporosity, were investigated. The activated carbons prepared from palm shell possessed well-developed porosity, predominantly microporosity, leading to potential applications in gas-phase adsorption for air pollution control. Static and dynamic adsorption tests for sulfur dioxide (SO(2)), a common gaseous pollutant, were carried out in a thermogravimetric analyzer and a packed column configuration respectively. The effects of adsorption temperature, adsorbate inlet concentration, and adsorbate superficial velocity on the adsorptive performance of the prepared activated carbons were studied. The palm-shell activated carbon was found to have substantial capability for the adsorption of SO(2), comparable to those of some commercial products and an adsorbent derived from another biomass. PMID:16290726

Guo, Jia; Lua, Aik Chong

2002-07-15

260

Models for the Centimeter-Wavelength Opacity of Sulfur Dioxide and Carbon Dioxide based on Laboratory Measurements Conducted under Simulated Conditions for the Deep Atmosphere of Venus  

NASA Astrophysics Data System (ADS)

In the past two decades, multiple observations of Venus have been made at X band (3.6 cm) using the Jansky Very Large Array (VLA), and maps have been created of the 3.6 cm emission from Venus. Since the emission morphology is related both to surface features and to deep atmospheric absorption from CO2 and SO2 (see, e.g., Butler et al., Icarus 154, 2001), knowledge of the microwave absorption properties of sulfur dioxide in a carbon dioxide atmosphere under conditions for the deep atmosphere of Venus is required for proper interpretation. Initial measurements of the centimeter-wavelength (3.7-20 cm) of SO2 and CO2 under simulated conditions for the deep atmosphere of Venus, conducted using a new high-pressure system operating at 430 K and at pressures up to 92 Bars, were presented by Steffes and Barisich (DPS-2012, B.A.A.S., v.44, p.241). Over the past year, we have completed this measurement campaign for temperatures up to 550 K, so as to better understand the effects of SO2 and CO2 on the microwave emission from the Venus boundary layer. Results indicate that the model for the centimeter-wavelength opacity from pure CO2 (developed over 40 years ago -- Ho et al., JGR 71, 1966), is valid over the entire centimeter-wavelength range under simulated conditions for the deep atmosphere of Venus. Additionally, the laboratory results indicate that the model for the centimeter-wavelength opacity of SO2 in a CO2 atmosphere from Suleiman et al. (JGR-Planets, 101, Feb. 1996) can reliably be used under conditions of the deep atmosphere of Venus with the modifications described in this paper . This work is supported by the NASA Planetary Atmospheres Program under Grant NNX11AD66G.

Steffes, Paul G.; Shahan, P. M.

2013-10-01

261

Photosynthesis, carbon allocation, and growth of sulfur dioxide ecotypes of Geranium carolinianum L  

Microsoft Academic Search

Summary This study investigated ways in which genetically determined differences in SO2 susceptibility resulting from ecotypic differentiation inGeranium carolinianum were expressed physiologically. The SO2-resistant and SO2-sensitive ecotypes were exposed to a combination of short- and long-term SO2 exposures to evaluate the responses of photosynthesis, H2S efflux from foliage (sulfur detoxification), photoassimilate retention, leaf-diffusive resistance to CO2, and growth. When exposed

G. E. Taylor; D. T. Tingey; C. A. Gunderson

1986-01-01

262

Evaluation of lithium sulfur dioxide batteries. US Army Communications - Electronics Command and US Army Electronics Research and Development Command, Fort Monmouth, New Jersey, 1 May-1 October 1984. Technical report, 1 May-1 OctobeR 1984  

SciTech Connect

Lithium sulfur dioxide batteries were analyzed to determine their hazardous waste characteristics under United States environmental regulations. The batteries were subjected to the hazardous waste criteria under 49 CFR 261 for ignitability, corrosivity, reactivity and toxicity. Extraction Procedure Toxicity (EP Tox) method was used to determine toxicity. Under these regulations and methods, lithium sulfur dioxide batteries are not listed as hazardous waste; however, they were found to be reactive hazardous waste (DOO3), and components exhibit ignitable characteristics. Further, fully discharged batteries are not hazardous waste. Lithium sulfur dioxide, Batteries, Environmental regulations, Analysis, Hazardous waste, Hazardous waste characteristics, Hazardous waste identification.

Rosak, D.A.

1985-02-07

263

Source-Receptor Relationships for East Asian Sulfur Dioxide Emissions and Northern Hemisphere Sulfate Concentrations  

NASA Astrophysics Data System (ADS)

We analyze the effect of varying East Asian (EA) sulfur emissions on sulfate concentrations in the northern hemisphere based on a global coupled oxidant-aerosol model (MOZART-2) driven with NCEP reanalysis meteorology for 1991. We conduct a base and several sensitivity simulations, in which sulfur emissions from each continent are tagged, to establish the source-receptor (S-R) relationship between EA sulfur emissions and sulfate concentrations over the source and downwind regions. We find that reducing EA SO2 emissions will significantly decrease the spatial extent of the EA sulfate influence over the North Pacific, but raising EA SO2 emissions will not significantly increase the spatial extent of influence. We define a linearity index and find the S-R relationship between EA SO2 emissions and EA sulfate concentrations to be nearly linear over most downwind regions, but to be non-linear over the EA source region, particularly at the surface and in winter. In addition, we find that besides the direct transport of EA sulfate to North America (NA) and Europe (EU), the indirect response of locally-produced NA or EU sulfate to changes in EA SO2 emissions is negative (i.e., offsetting the direct effect) in winter, spring and fall, but becomes positive in summer. In summer the indirect response is as important as direct transport of EA sulfate over the southeastern U.S. and southern EU. This summertime positive indirect effect largely results from induced changes in H2O2 oxidant concentrations over these regions.

Liu, J.; Mauzerall, D. L.; Horowitz, L. W.

2007-12-01

264

Why are dimethyl sulfoxide and dimethyl sulfone such good solvents?  

PubMed

We have carried out B3PW91 and MP2-FC computational studies of dimethyl sulfoxide, (CH(3))(2)SO, and dimethyl sulfone, (CH(3))(2)SO(2). The objective was to establish quantitatively the basis for their high polarities and boiling points, and their strong solvent powers for a variety of solutes. Natural bond order analyses show that the sulfur-oxygen linkages are not double bonds, as widely believed, but rather are coordinate covalent single S(+)-->O(-) bonds. The calculated electrostatic potentials on the molecular surfaces reveal several strongly positive and negative sites (the former including sigma-holes on the sulfurs) through which a variety of simultaneous intermolecular electrostatic interactions can occur. A series of examples is given. In terms of these features the striking properties of dimethyl sulfoxide and dimethyl sulfone, their large dipole moments and dielectric constants, their high boiling points and why they are such good solvents, can readily be understood. PMID:18458968

Clark, Timothy; Murray, Jane S; Lane, Pat; Politzer, Peter

2008-08-01

265

The production of sulfate particles through the radiolytic oxidation of sulfur dioxide  

SciTech Connect

The production of hydroxyl radicals by the radiolytic decomposition of water vapor following alpha decay of {sup 222}Rn can be used to produce an ultrafine sulfuric acid aerosol in the presence of SO{sub 2}. In the past, the production of this aerosol appeared to have a limiting threshold in as much as sufficient conversion of SO{sub 2} to SO{sub 4} must be attained to achieve the concentration required for nucleation. This appeared to occur when the bulk average acidity reached an adequately high value. The threshold curve for the onset of the sulfuric acid aerosol formation is a function of the H{sub 2}O, SO{sub 2} and Rn concentrations. The hydroxyl radical formation is dependent on the H{sub 2}O and Rn concentrations. The mass conversion rate of SO{sub 2} to H{sub 2}SO{sub 4} has been studied by measuring the airborne H{sub 2}SO{sub 4} concentration by ion chromatography after it has been collected on a filter and leached into solution. 39 refs., 9 figs.

Karpen-Hayes, K.

1991-09-13

266

Vertical distribution of dimethylsulfide, sulfur dioxide, aerosol ions, and radon over the northeast Pacific Ocean  

NASA Technical Reports Server (NTRS)

The vertical distributions, in temperate latitudes, of dimethylsulfide (DMS), SO2, radon, methanesulfonate (MSA), nonsea-salt sulfate (nss-sulfate), and aerosol Na(+), NH4(+), and NO(-) ions were determined in samples collected by an aircraft over the northeast Pacific Ocean during May 3-12, 1985. DMS was also determined in surface seawater. It was found that DMS concentrations, both in seawater and in the atmospheric boundary layer, were significantly lower than the values reported previously for subtropical and tropical regions, reflecting the seasonal variability in the temperate North Pacific. The vertical profiles of DMS, MSA, SO2, and nss-sulfate were found to be strongly dependent on the convective stability of the atmosphere and on air mass origin. Biogenic sulfur emissions could account for most of the sulfur budget in the boundary layer, while the long-range transport of continentally derived air masses was mainly responsible for the elevated levels of both SO2 and nss-sulfate in the free troposphere.

Andreae, M. O.; Berresheim, H.; Andreae, T. W.; Kritz, M. A.; Bates, T. S.

1988-01-01

267

Electrophoresis pattern of serum from mice exposed to different concentrations of sulfur dioxide  

NASA Technical Reports Server (NTRS)

Three day old mice were continuously exposed to sulphur dioxide concentrations at 0ppm, 0.05ppm, 0.15ppm and 1ppm for eight weeks. At the end of the experiment, blood samples were collected and centrifuged for electrophoresis studies of the serum in 5 percent acrylamide gel. The length of bands of different serum proteins from the SO2 exposed mice was at a variance as compared with the length of bands from the control exposed mice and alpha-1 band seems to be missing from the serum of SO2 exposed mice.

Singh, J.

1977-01-01

268

Development of a countercurrent multistage fluidized-bed reactor and mathematical modeling for prediction of removal efficiency of sulfur dioxide from flue gases  

SciTech Connect

A bubbling countercurrent multistage fluidized-bed reactor for the sorption of sulfur dioxide by hydrated lime particles was simulated employing a two-phase model, with the bubble phase assumed to be in plug flow and with the emulsion phase either in plug flow (EGPF model) or in perfectly mixed flow (EGPM model). The model calculations were compared with experimental data in term of percentage removal efficiency of sulfur dioxide. Both models were applied to understand the influence of operating parameters on the reactor performance. The comparison showed that the EGPF model agreed well with the experimental data. From the perspective of use of a multistage fluidized-bed reactor as air pollution control equipment in industry, the model could be considered general enough for predicting the performance of reactors for gas-solid treatment.

Mohanty, C.R.; Malavia, G.; Meikap, B.C. [Indian Institute of Technology, Kharagpur (India). Dept. of Chemical Engineering

2009-02-15

269

Laboratory measurements of the 3.7-20 cm wavelength opacity of sulfur dioxide and carbon dioxide under simulated conditions for the deep atmosphere of Venus  

NASA Astrophysics Data System (ADS)

In the past two decades, multiple observations of Venus have been made at X-Band (3.6 cm) using the Jansky Very Large Array (VLA), and maps have been created of the 3.6 cm emission from Venus (see, e.g., Devaraj, K. [2011]. The Centimeter- and Millimeter-Wavelength Ammonia Absorption Spectra under Jovian Conditions. PhD Thesis, Georgia Institute of Technology, Atlanta, GA). Since the emission morphology is related both to surface features and to deep atmospheric absorption from CO2 and SO2 (see, e.g., Butler, B.J., Steffes, P.G., Suleiman, S.H., Kolodner, M.A., Jenkins, J.M. [2001]. Icarus 154, 226-238), knowledge of the microwave absorption properties of sulfur dioxide in a carbon dioxide atmosphere under conditions for the deep atmosphere of Venus is required for proper interpretation. Except for a single measurement campaign conducted at a single wavelength (3.2 cm) over 40 years ago (Ho, W., Kaufman, I.A., Thaddeus, P. [1966]. J. Geophys. Res. 71, 5091-5108), no measurements of the centimeter-wavelength properties of any Venus atmospheric constituent have been conducted under conditions characteristic of the deep atmosphere (pressures from 10 to 92 bars and temperatures from 400 to 700 K). New measurements of the microwave properties of SO2 and CO2 at wavelengths from 3.7 to 20 cm have been conducted under simulated conditions for the deep atmosphere of Venus, using a new high-pressure system. Results from this measurement campaign conducted at temperatures from 430 K to 560 K and at pressures up to 92 bars are presented. Results indicate that the model for the centimeter-wavelength opacity from pure CO2 (Ho, W., Kaufman, I.A., Thaddeus, P. [1966]. J. Geophys. Res. 71, 5091-5108), is valid over the entire centimeter-wavelength range under simulated conditions for the deep atmosphere of Venus. Additionally, the laboratory results indicate that both of the models for the centimeter-wavelength opacity of SO2 in a CO2 atmosphere from Suleiman et al. (Suleiman, S.H., Kolodner, M.A., Steffes, P.G. [1996]. J. Geophys. Res. 101, 4623-4635) and from Fahd and Steffes (Fahd, A.K., Steffes, P.G. [1992]. Icarus 97, 200-210) can reliably be used under conditions of the deep atmosphere of Venus.

Steffes, Paul G.; Shahan, Patrick; Christopher Barisich, G.; Bellotti, Amadeo

2015-01-01

270

Theoretical and experimental studies of the spin trapping of inorganic radicals by 5,5-dimethyl-1-pyrroline N-oxide (DMPO). 1. Carbon dioxide radical anion.  

PubMed

The carbon dioxide radical anion (CO2*-) is known to be generated in vivo through various chemical and biochemical pathways. Electron paramagnetic resonance (EPR) spin trapping with the commonly used spin trap, 5,5-dimethyl-1-pyrroline N-oxide (DMPO), has been employed in the detection of CO2*-. The thermodynamics of CO2*- addition to DMPO was predicted using density functional theory (DFT) at the B3LYP/6-31++G**//B3LYP/6-31G* and B3LYP/6-311+G* levels with the polarizable continuum model (PCM) to simulate the effect of the bulk dielectric effect of water on the calculated energetics. Three possible products of CO2*- addition to DMPO were predicted: (1) a carboxylate adduct, (2) pyrroline-alcohol and (3) DMPO-OH. Experimentally, UV photolysis of H2O2 in the presence of sodium formate (NaHCO2) and DMPO gave an EPR spectrum characteristic of a C-centered carboxylate adduct and is consistent with the theoretically derived hyperfine coupling constants (hfcc). The pKa of the carboxylate adduct was estimated computationally to be 6.4. The mode of CO2*- addition to DMPO is predicted to be governed predominantly by the spin (density) population on the radical, whereas electrostatic effects are not the dominant factor for the formation of the persistent adduct. The thermodynamic behavior of CO2*- in the aqueous phase is predicted to be similar to that of mercapto radical (*SH), indicating that formation of CO2*- in biological systems may have an important role in the initiation of oxidative damage in cells. PMID:17149843

Villamena, Frederick A; Locigno, Edward J; Rockenbauer, Antal; Hadad, Christopher M; Zweier, Jay L

2006-12-14

271

Utilization of a Response-Surface Technique in the Study of Plant Responses to Ozone and Sulfur Dioxide Mixtures 1  

PubMed Central

A second order rotatable design was used to obtain polynomial equations describing the effects of combinations of sulfur dioxide (SO2) and ozone (O3) on foliar injury and plant growth. The response surfaces derived from these equations were displayed as contour or isometric (3-dimensional) plots. The contour plots aided in the interpretation of the pollutant interactions and were judged easier to use than the isometric plots. Plants of `Grand Rapids' lettuce (Lactuca sativa L.), `Cherry Belle' radish (Raphanus sativus L.), and `Alsweet' pea (Pisum sativum L.) were grown in a controlled environment chamber and exposed to seven combinations of SO2 and O3. Injury was evaluated based on visible chlorosis and necrosis and growth was evaluated as leaf area and dry weight. Covariate measurements were used to increase precision. Radish and pea had greater injury, in general, that did lettuce; all three species were sensitive to O3, and pea was most sensitive and radish least sensitive to SO2. Leaf injury responses were relatively more affected by the pollutants than were plant growth responses in radish and pea but not in lettuce. In radish, hypocotyl growth was more sensitive to the pollutants than was leaf growth. PMID:16663598

Ormrod, Douglas P.; Tingey, David T.; Gumpertz, Marcia L.; Olszyk, David M.

1984-01-01

272

Bisulfite and sulfite as derivatives of sulfur dioxide alters biomechanical behaviors of airway smooth muscle cells in culture.  

PubMed

Sulfur dioxide (SO2) is a common air pollutant that triggers asthmatic symptoms, but its toxicological mechanisms are not fully understood. Specifically, it is unclear how SO2 in vivo affects airway smooth muscle (ASM) cells of which the mechanics is known to ultimately mediate airway hyperresponsiveness (AHR) - a hallmark feature of asthma. To this end, we investigated the effects of bisulfite/sulfite (1:3 M/M in neutral fluid to simulate the in vivo derivatives of inhaled SO2 in the airways), on the viability, migration, stiffness and contractility of ASM cells cultured in vitro. The results showed that bisulfite/sulfite consistently increased viability, migration, F-actin intensity and stiffness of ASM cells in similar fashion as concentration increasing from 10(-4) to 10(-1)?mmol/L. However, bisulfite/sulfite increased the ASM cell contractility induced by KCl only at the concentration between 10(-4) and 10(-3)?mmol/L (p?

Song, Aijing; Lin, Feng; Li, Jianming; Liao, Qingfeng; Liu, Enmei; Jiang, Xuemei; Deng, Linhong

2014-02-01

273

Photoionization studies of internally reactive small clusters: Van der Waals complexes of 1,3-butadiene with sulfur dioxide  

SciTech Connect

Efficiency functions for ions from the title complexes were measured using a photoionization mass spectrometer in which a molecular beam of target complexes, formed by a skimmed and recollimated free jet expansion of 1,3-butadiene + SO{sub 2}, was made to intersect a tunable VUV beam from Brookhaven's 750-MeV electron storage ring. The dissociation energies at 0 K of 1,3-C{sub 4}H{sub 6}{center dot}SO{sub 2} and (1,3-C{sub 4}H{sub 6}{center dot}SO{sub 2}){sup +} were measured to be 3.24 {plus minus} 0.48 and 3.00 {plus minus} 0.68 kcal mol{sup {minus}1}, respectively. For 3-sulfolene, the condensation product, the ionization potential was measured to be 10.073 {plus minus} 0.006 eV, while the appearance potential of its fragment C{sub 4}H{sub 6}{sup +} is 10.076 {plus minus} 0.029 eV, the same within the experimental uncertainty. However, the sulfolene parent ion is unstable with respect to disintegration into butadiene ion and sulfur dioxide by 0.38 {plus minus} 0.03 eV.

Grover, J.R.; Walters, E.A.; Newman, J.K.; White, M.G. (Brookhaven National Lab., Upton, NY (USA))

1990-08-29

274

Laboratory and field measurements of dry deposition of sulfur dioxide onto Chinese loess surfaces.  

PubMed

Laboratory and field measurements were conducted to examine dry deposition of SO2 onto Chinese loess surfaces using native soil sampled in the loess plateau, China. The field tests were employed in Beijing and Lanzhou, China, by directly measuring the dry deposition of SO2 on soil, which uses soil put on a collector as an SO2 passive sampling medium. In the laboratory, a high rate of uptake to SO2 deposition for Chinese soil surfaces due to the highly alkalinity was found. The uptake of SO2 deposition was dependent on the pH soil and relative humidity. Furthermore, we evaluated some factors that affect the measurement precision: response of SO2 uptake, repeatability, recovery factor, and variability associated with the weight and the surface coverage on the collectors. As a result, it was shown that the measurement precision was primarily related to the ratio of the SO2 deposition amount relative to the sulfur content of the original soil. This result was consistent with the field observations. The laboratory and field results indicated an excellent agreement on the SO2 uptake inherent in the results from the soil surfaces in different regions. PMID:15260340

Sorimachi, Atsuyuki; Sakamoto, Kazuhiko; Sakai, Mio; Ishihara, Hidekazu; Fukuyama, Tsutomu; Utiyama, Masahiro; Liu, Hongjie; Wang, Wei; Tang, Dagang; Dong, Xuhui; Quan, Hao

2004-06-15

275

Erosion of frozen sulfur dioxide by ion bombardment - Applications to Io  

NASA Technical Reports Server (NTRS)

The erosion of frozen SO2 due to bombardment by both light and heavy ions (He and F) was measured for bombarding energies of 0.08 to 1.3 MeV/amu. The number of SO2 molecules ejected from the target per incident ion (i.e., the sputtering yield) was 50 for 1.5 MeV He ions and 7300 for 6 MeV F ions. Ion bombardment followed by heating produced an oxygen/sulfur residue which was much more stable against subsequent ion bombardment than the initial frozen SO2. The erosion rate of SO2 frost on Jupiter's moon Io depends strongly on the elemental composition and energy spectra of the magnetospheric ion flux which bombards the surface. The combined effects of ion bombardment and heating which produced residues on the target substrates may also occur on Io from magnetospheric ion bombardment and heating by volcanism. The experimental results compare favorably with a new model of the sputtering process which considers the energy loss of the incident ion to electronic excitation in the target.

Melcher, C. L.; Lepoire, D. J.; Cooper, B. H.; Tombrello, T. A.

1982-01-01

276

Investigation on mercury removal method from flue gas in the presence of sulfur dioxide.  

PubMed

A new integrated process was developed for the removal and reclamation of mercury from the flue gas in the presence of SO2, typically derived from nonferrous metal smelting. The new process contains a pre-desulfurization unit (Stage I) and a co-absorption unit (Stage II). In Stage I, 90% of the SO2 from flue gas can be efficiently absorbed by ferric sulfate and reclaimed sulfuric acid. Meanwhile, the proportion of Hg(2+) and Hg(0) in the flue gas can be redistributed in this stage. Then, over 95% of the Hg(0) and the residual SO2 can be removed simultaneously with a composite absorption solution from the flue gas in Stage II, which is much more efficient for the Hg(0) reclaiming than the traditional method. The composite absorption solution in Stage II, which is composed of 0.1g/L HgSO4, 1.0% H2O2 and H2SO4, could effectively remove and reclaim Hg(0) overcoming the negative effect of SO2 on Hg(0) absorption. Moreover, the concentrations of HgSO4 and H2O2 were adjusted with the changes in of the concentrations of Hg(0) and SO2 in the flue gas. It is a potential and promising technology for the mercury removal and reclaim from the flue gas in the presence of SO2. PMID:25072135

Ma, Yongpeng; Qu, Zan; Xu, Haomiao; Wang, Wenhua; Yan, Naiqiang

2014-08-30

277

The last decade of global anthropogenic sulfur dioxide: 2000-2011 emissions  

NASA Astrophysics Data System (ADS)

The evolution of global and regional anthropogenic SO2 emissions in the last decade has been estimated through a bottom-up calculation. After increasing until about 2006, we estimate a declining trend continuing until 2011. However, there is strong spatial variability, with North America and Europe continuing to reduce emissions, with an increasing role of Asia and international shipping. China remains a key contributor, but the introduction of stricter emission limits followed by an ambitious program of installing flue gas desulfurization on power plants resulted in a significant decline in emissions from the energy sector and stabilization of total Chinese SO2 emissions. Comparable mitigation strategies are not yet present in several other Asian countries and industrial sectors in general, while emissions from international shipping are expected to start declining soon following an international agreement to reduce the sulfur content of fuel oil. The estimated trends in global SO2 emissions are within the range of representative concentration pathway (RCP) projections and the uncertainty previously estimated for the year 2005.

Klimont, Z.; Smith, S. J.; Cofala, J.

2013-03-01

278

Sulfur dioxide emissions from combustion in china: from 1990 to 2007.  

PubMed

China has become the world's largest emitter of SO(2) since 2005, and aggressive deployment of flue gas desulfurization (FGD) at coal-fired power plants appeared in China when facing the formidable pressure of environment pollution. In this work, we estimate the annual emission from combustion sources at provincial levels in China from 1990 to 2007, with updated data investigations. We have implemented the method of transportation matrix to gain a better understanding of sulfur content of coal in consuming provinces, which in turn improved the inventory. The total emissions from combustion in 2007 were 28.3 Tg, half of which was contributed by coal-fired power plants. Meanwhile, the industrial boiler coal combustion and residential coal consumed in centralized heating were responsible for another 32% of the total emissions. From 1990 to 2007, annual SO(2) emission was fluctuated with two peaks (1996 and 2006), and total emission doubled from 15.4 Tg to 30.8 Tg, at an annual growth rate of 4.4% (6.3% since 2000). Due to the extensive application of FGD technology and the phase-out of small, high emitting units, the SO(2) emission began to decrease after 2006. Furthermore, the differences among estimates reported in literatures highlight a great need for further research to reduce the uncertainties with more detailed information on key sources and actual operation of devices. PMID:21851093

Su, Shenshen; Li, Bengang; Cui, Siyu; Tao, Shu

2011-10-01

279

The last decade of global anthropogenic sulfur dioxide: 2000-2011 emissions  

SciTech Connect

Evolution of global and regional anthropogenic SO2 emissions in the last decade has been estimated through a bottom-up calculation for recent years. After a strong increase in emissions that peaked about 2006, we estimate a declining trend continuing until 2011. However, there is a strong spatial variability with North America and Europe continuing to reduce emissions with an increasing role of Asia and international shipping. China remains a key contributor but the introduction of stricter emission limits followed by an ambitious program of installing flue gas desulfurization on power plants resulted in significant decline in emissions from energy sector and stabilization of Chinese SO2 emissions. Comparable mitigation strategies are not yet present in several other Asian countries and industrial sectors in general, while emissions from international shipping are expected to start declining soon following agreed reduction of sulfur content of fuel oil. Estimated trends in global SO2 emissions are within the range of RCP projections and uncertainty calculated for the year 2005.

Klimont, Z.; Smith, Steven J.; Cofala, Janusz

2013-01-09

280

210 X 297mm Dimethyl Carbonate  

E-print Network

-chloride and dimethly-sulfuric acid for carbonylation and methylation reactions. Reactive distillation process Development for the Continuous Production of Dimethyl Carbonate by Reactive Distillation () 20004 . 11 for the Continuous Production of Dimethyl Carbonate by Reactive Distillation 2001 . 10 . 1 . 2004 . 9 . 30

Hong, Deog Ki

281

40 CFR Appendix A-1 to Part 50 - Reference Measurement Principle and Calibration Procedure for the Measurement of Sulfur Dioxide...  

Code of Federal Regulations, 2011 CFR

...NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS Pt. 50, App. A-1 ...national primary and secondary ambient air quality standards for sulfur oxides (sulfur...Measurement Systems—Volume II. Ambient Air Quality Monitoring Programs. U.S....

2011-07-01

282

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

283

Cell type specificity of female lung cancer associated with sulfur dioxide from air pollutants in Taiwan: An ecological study  

PubMed Central

Background Many studies have examined the association between air pollutants (including sulfur dioxide [SO2], carbon monoxide [CO], nitrogen dioxide [NO2], nitric oxide [NO], ozone [O3], and particulate matter < 10 ?m [PM10]) and lung cancer. However, data from previous studies on pathological cell types were limited, especially for SO2 exposure. We aimed to explore the association between SO2 exposure from outdoor air pollutants and female lung cancer incidence by cell type specificity. Methods We conducted an ecological study and calculated annual average concentration of 6 air pollutants (SO2, CO, NO2, NO, O3, and PM10) using data from Taiwan Environmental Protection Administration air quality monitoring stations. The Poisson regression models were used to evaluate the association between SO2 and age-standardized incidence rate of female lung cancer by two major pathological types (adenocarcinoma [AC] and squamous cell carcinoma [SCC]). In order to understand whether there is a dose-response relationship between SO2 and two major pathological types, we analyzed 4 levels of exposure based on quartiles of concentration of SO2. Results The Poisson regression results showed that with the first quartile of SO2 concentration as the baseline, the relative risks for AC/SCC type cancer among females were 1.20 (95% confidence interval [CI], 1.04-1.37)/1.39 (95% CI, 0.96-2.01) for the second, 1.22 (95% CI, 1.04-1.43)/1.58 (95% CI, 1.06-2.37) for the third, and 1.27 (95% CI, 1.06-1.52)/1.80 (95% CI, 1.15-2.84) for the fourth quartile of SO2 concentration. The tests for trend were statistically significant for both AC and SCC at P = 0.0272 and 0.0145, respectively. Conclusion The current study suggests that SO2 exposure as an air pollutant may increase female lung cancer incidence and the associations with female lung cancer is much stronger for SCC than for AC. The findings of this study warrant further investigation on the role of SO2 in the etiology of SCC. PMID:22214195

2012-01-01

284

Land Use Regression Modeling To Estimate Historic (1962?1991) Concentrations of Black Smoke and Sulfur Dioxide for Great Britain  

PubMed Central

Land-use regression modeling was used to develop maps of annual average black smoke (BS) and sulfur dioxide (SO2) concentrations in 1962, 1971, 1981, and 1991 for Great Britain on a 1 km grid for use in epidemiological studies. Models were developed in a GIS using data on land cover, the road network, and population, summarized within circular buffers around air pollution monitoring sites, together with altitude and coordinates of monitoring sites to consider global trend surfaces. Models were developed against the log-normal (LN) concentration, yielding R2 values of 0.68 (n = 534), 0.68 (n = 767), 0.41 (n = 771), and 0.39 (n = 155) for BS and 0.61 (n = 482), 0.65 (n = 733), 0.38 (n = 756), and 0.24 (n = 153) for SO2 in 1962, 1971, 1981, and 1991, respectively. Model evaluation was undertaken using concentrations at an independent set of monitoring sites. For BS, values of R2 were 0.56 (n = 133), 0.41 (n = 191), 0.38 (n = 193), and 0.34 (n = 37), and for SO2 values of R2 were 0.71 (n = 121), 0.57 (n = 183), 0.26 (n = 189), and 0.31 (n = 38) for 1962, 1971, 1981, and 1991, respectively. Models slightly underpredicted (fractional bias: 0??0.1) monitored concentrations of both pollutants for all years. This is the first study to produce historic concentration maps at a national level going back to the 1960s. PMID:21446726

2011-01-01

285

Flux determinations and physiological response in the exposure of red spruce to gaseous hydrogen peroxide, oxone, and sulfur dioxide  

SciTech Connect

The 3-week exposure of a branch of a forest-grown red spruce (Picea rubens) sapling to the combination of gaseous hydrogen peroxide, ozone, and sulfur dioxide is reported on. The exposure was conducted continuously using concentrations of H{sub 2}O{sub 2}, O{sub 3}, and SO{sub 2} that have been observed during the summertime on the summit of Whiteface Mountain, New York. Fluxes of H{sub 2}O, CO{sub 2}, and the three pollutants were determined throughout the exposure. At weekly intervals, measurements of chlorophyll fluorescence, stomatal conductance, and hydrocarbon emissions were made. The response of the branch was compared to an equivalent branch of the same tree which received no pollutants but was otherwise treated identically. The exposure produced no visible injury symptoms but did produce an increase in dark respiration; the respiration rate more than doubled during the 21-day exposure period. Net photosynthesis was unaffected for both the experimental and the control branches. Nighttime fluxes of SO{sub 2} and H{sub 2}O{sub 2} to external plant surfaces were significant. The stomatal component of O{sub 3} uptake by the branch displayed a linear increase during the experiment, and showed no evidence of saturating. Daytime and nighttime fluxes of H{sub 2}O{sub 2} were increasing at the end of the experiment. It was observed that isoprene is emitted from red spruce, but saw no clear-cut change in emission rate in response to the exposure experiment.

Ennis, C.A.; Lazrus, A.L.; Zimmerman, P.R.; Monson, R.K.

1990-01-01

286

N2-, O2- and He-collision-induced broadening of sulfur dioxide ro-vibrational lines in the 9.2 ?m atmospheric window  

NASA Astrophysics Data System (ADS)

Sulfur dioxide (SO2) is a molecule of considerable interest for both atmospheric chemistry and astrophysics. In the Earth's atmosphere, it enters in the sulfur cycle and it is ubiquitous present in polluted atmospheres, where it is responsible for acid rains. It is also of astrophysical and planetological importance, being present on Venus and in interstellar clouds. In this work the collisional broadening of a number of ?1 ro-vibrational lines of SO2 perturbed by N2, O2 and He are investigated at room temperature in the 9 ?m atmospheric region by means of high resolution tunable diode laser (TDL) infrared spectroscopy. From N2- and O2-broadening coefficients, the broadening parameters of sulfur dioxide in air, useful for atmospheric applications, are derived as well. From the present measurements some conclusions on the quantum number dependence of the N2-, O2- and He-broadening coefficients are drawn. While the J dependence is weak for all the perturbers investigated, different trends with Ka are reported. N2-broadening coefficients show a slight decrease with increasing values of Ka, whereas O2 and He broadening cross sections first increase up to Ka??6 and then they keep a nearly constant value. A comparison and a brief discussion on the efficiency of self-, N2-, O2- and He-collisional dynamics are given. The data obtained represent a significant analysis on foreign broadening of SO2 useful for atmospheric remote sensing and astrophysical applications.

Tasinato, Nicola; Pietropolli Charmet, Andrea; Stoppa, Paolo; Giorgianni, Santi; Buffa, Giovanni

2014-01-01

287

Sulfuric acid on Europa and the radiolytic sulfur cycle  

NASA Technical Reports Server (NTRS)

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

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

1999-01-01

288

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

289

Total fluxes of sulfur dioxide from the Italian volcanoes Etna, Stromboli, and Vulcano measured by differential absorption lidar and passive differential optical absorption spectroscopy  

SciTech Connect

The authors present measurements of the total flux of sulfur dioxide from three Italian volcanoes Etna, Stromboli, and Vulcano, measured in a three day period in Sept, 1992. The fluxes were measured from shipboard by means of an active differential absorption lidar technique, and a passive differential optical absorption spectroscopy technique. Corrections had to be applied to the passive optical technique because the light source paths were not well defined. The total fluxes were found to be roughly 25, 180, and 1300 tons/day for Vulcano, Stromboli, and Etna, respectively. 43 refs., 10 figs., 6 tabs.

Edner, H.; Ragnarson, P.; Svanberg, S.; Wallinder, E. [Lund Institute of Technology (Sweden)] [Lund Institute of Technology (Sweden); Ferrara, R. [Istituto di Biofisica, Pisa (Italy)] [Istituto di Biofisica, Pisa (Italy); Cioni, R.; Raco, B.; Taddeucci, G. [Istituto di Geocronologia e Geochimica Isotopica, Pisa (Italy)] [Istituto di Geocronologia e Geochimica Isotopica, Pisa (Italy)

1994-09-20

290

The defense potential of glutathione-ascorbate dependent detoxification pathway to sulfur dioxide exposure in Tagetes erecta.  

PubMed

Sulfur dioxide (SO2) exposure is associated with increased risk of various damages to plants. However, little is known about the defense response in ornamental plants. In this study, an artificial fumigation protocol was carried out to study the defense potential of the glutathione (GSH)-ascorbate (AsA) dependent detoxification pathway to SO2 exposure in Tagetes erecta. The results show that when the plants were exposed to different doses of SO2 (0, 15, 30, 50 or 80mgm(-3)) for different times (6, 12, 18, 24 or 33h), SO2 induced oxidative stress was confirmed by the increased hydrogen peroxide (H2O2), malondialdehyde (MDA) and relative conductivity of membrane (RC) in a dose-dependent manner for different exposure times. However, the increased levels for H2O2, MDA and RC were not significant vis-a-vis the control when SO2 doses and exposure times were lower than 15mgm(-3)/33h, 30mgm(-3)/24h or 50mgm(-3)/12h (p>0.05). The results could be explained by the increases in the content of reduced form of glutathione (GSH), total glutathione (TGSH), ascorbate (AsA), ratio of GSH/GSSG (oxidized form of glutathione), activities of ascorbate peroxidase (APX), glutathione peroxidase (GPX), glutathione reductase (GR) and glutathione S-transferases (GST). On the other hand, exposure to higher doses of SO2 and longer exposure times, the values of the GSH-AsA dependent antioxidative indices decreased significantly (p<0.01), manifested by increased levels of H2O2. Furthermore, the levels of H2O2, MDA and RC varied little when SO2 doses and exposure times reached a 'critical' value (50mgm(-3)/24h). The defense ability of T. erecta to SO2 reached nearly extremity. To summarize, the response of T. erecta to elevated SO2 was related to higher H2O2 levels. GSH-AsA dependent detoxification pathway played an important role in against SO2-induced toxicity, although the defense response could not sufficiently alleviate oxidative damage when SO2 doses and exposure times reached critical value. PMID:25450923

Wei, Aili; Fu, Baochun; Wang, Yunshan; Li, Rui; Zhang, Chao; Cao, Dongmei; Zhang, Xiaobing; Duan, Jiuju

2015-01-01

291

Volcanic monitoring from space using neural networks approach. Simultaneous ash and sulfur dioxide retrievals using multispectral measurements  

NASA Astrophysics Data System (ADS)

In this work a Multi Layer Perceptron Neural Networks (MLPNN) approach has been used for a simultaneous volcanic ash and sulfur dioxide retrievals considering the MODIS measurements. As test case the 2010 Eyjafjallajokull eruption have been considered. A network was built for each parameter to be retrieved. Additionally, for volcanic ash, a network for the classification of "ash image pixels" was implemented, which was then used to mask the estimates. Several network topologies were compared in terms of their performance. Concerning the training phase and networks testing, a set of MODIS images was selected covering the Eyjafjallajokull May events. The classification NNs were trained with the volcanic ash classification map obtained with the Brightness Temperature Difference algorithm, assumed as benchmark. The neural networks for the quantitative estimation of the parameters associated with volcanic ash, mass, effective radius, aerosol optical depth and SO2, were instead trained with maps obtained using consolidated estimation algorithms based on simulated radiances at the top of the atmosphere, generated in turn applying a radiative transfer model to remote sensing data. The networks proved to be very effective in solving the inversion problem related to the estimation of the parameters of the volcanic cloud, settling the crucial issue related to false alarms in the detection of volcanic ash. Furthermore, once the training phase is complete, NNs provide a faster inversion technique, useful for the applications. From this point of view the technique satisfies the need to respond quickly as a result of disastrous natural hazards, such as volcanic eruptions. Future activities include testing the effectiveness of the technique under different lighting conditions (night images) and on other types of multispectral data, such as that provided by high temporal resolution sensors like SEVIRI-MSG, on board the METEOSAT second Generation satellites. The latter would be particularly suitable considering its exceptional quick response characteristics for real-time monitoring of the atmosphere. The use of hyperspectral data, recently used for the estimation of parameters associated with volcanic clouds, is also under consideration for future work.

Piscini, A.; Corradini, S.; Chini, M.; Merucci, L.; Stramondo, S.; Picchiani, M.; Del Frate, F.

2012-04-01

292

Associations between immune function in yearling beef cattle and airborne emissions of sulfur dioxide, hydrogen sulfide, and VOCs from oil and natural gas facilities.  

PubMed

Researchers assessed the associations between airborne emissions from oil and gas field facilities and the structure and function of the immune system of yearling beef cattle in 27 herds during spring 2002. They evaluated the immune systems of these animals by enumerating B lymphocytes and T-lymphocyte subtypes (CD4, CD8, gammadelta, and WC1) in peripheral circulation and by measuring systemic antibody production in response to vaccination. Researchers prospectively measured exposure to sulfur dioxide, hydrogen sulfide, and volatile organic compounds (VOCs) by using air-quality data from passive monitors installed in pastures and wintering areas. They estimated the mean exposure of each animal over the 6-month period before the start of sample collection. The researchers used mixed models, which adjusted for clustering by herd and accounted for known risk factors, to examine potential associations between exposure to airborne sulfur dioxide, VOCs (measured as concentrations of benzene and toluene) and hydrogen sulfide, as well as proximity to emission sources (well-site density), and the immune system outcomes. Increasing exposure to VOCs measured as toluene was associated with significant CD4 T lymphocytopenia. The number of CD4 T lymphocytes was 30% lower in cattle exposed to VOCs measured as toluene in the highest quartile (> 0.823 microg/m3) than in cattle exposed in the lowest quartile (< 0.406 microg/m3). PMID:19179269

Bechtel, Daniel G; Waldner, Cheryl L; Wickstrom, Mark

2009-01-01

293

Thermal decomposition of barium sulfate-vanadium pentaoxide-silica glass mixtures for preparation of sulfur dioxide in sulfur isotope ratio measurements  

Microsoft Academic Search

A previously reported procedure for the thermal decomposition of BaSOā-VāOā-SiOā for the preparation of SOā in sulfur isotope ratio measurements has been studied in detail, certain portions of the procedure have been modified, and certain aspects of the reaction mechanism have been defined. It was determined that the Ā¹āøO\\/Ā¹ā¶O ratio of SOā must be kept constant in order to apply

F. Yanaglsawa; Hitoshi. Sakai

1983-01-01

294

Potential particulate pollution derived from UV-induced degradation of odorous dimethyl sulfide.  

PubMed

UV-induced degradation of odorous dimethyl sulfide (DMS) was carried out in a static White cell chamber with UV irradiation. The combination of in situ Fourier transform infrared (FT-IR) spectrometer, gas chromatograph-mass spectrometer (GC-MS), wide-range particle spectrometer (WPS) technique, filter sampling and ion chromatographic (IC) analysis was used to monitor the gaseous and potential particulate products. During 240 min of UV irradiation, the degradation efficiency of DMS attained 20.9%, and partially oxidized sulfur-containing gaseous products, such as sulfur dioxide (SO2), carbonyl sulfide (OCS), dimethyl sulfoxide (DMSO), dimethyl sulfone (DMSO2) and dimethyl disulfide (DMDS) were identified by in situ FT-IR and GC-MS analysis, respectively. Accompanying with the oxidation of DMS, suspended particles were directly detected to be formed by WPS techniques. These particles were measured mainly in the size range of accumulation mode, and increased their count median diameter throughout the whole removal process. IC analysis of the filter samples revealed that methanesulfonic acid (MSA), sulfuric acid (H2SO4) and other unidentified chemicals accounted for the major non-refractory compositions of these particles. Based on products analysis and possible intermediates formed, the degradation pathways of DMS were proposed as the combination of the O(1D)- and the OH- initiated oxidation mechanisms. A plausible formation mechanism of the suspended particles was also analyzed. It is concluded that UV-induced degradation of odorous DMS is potentially a source of particulate pollutants in the atmosphere. PMID:21476340

Qiao, Liping; Chen, Jianmin; Yang, Xin

2011-01-01

295

The 1981-1982 NCLAN (National Crop Loss Assessment Network) program at LLNL: The effects of ozone and sulfur dioxide, singly and in combination, on field-grown tomato  

Microsoft Academic Search

The combined effects of ozone (Oā) and sulfur dioxide (SOā) exposures on tomato (Lycopersicon esculentum Mill.) crop yields were measured during the 1981 and 1982 growing seasons. The effort, part of the National Crop Loss Assessment Network (NCLAN), had the objective of determining the yield dose response of tomato grown under commercial conditions. Dose response was determined using step-wise multiple

K. A. Surano; R. G. Mutters; P. J. Temple; G. E. Bingham; J. R. Kercher; J. H. Shinn

1987-01-01

296

Halogen bonding to a divalent sulfur atom: an experimental study of the interactions of CF3X (X = Cl, Br, I) with dimethyl sulfide.  

PubMed

Using FTIR and Raman spectroscopy, the formation of halogen bonded complexes of the trifluorohalomethanes CF(3)Cl, CF(3)Br and CF(3)I with dimethyl sulfide (DMS) dissolved in liquid krypton has been investigated. For CF(3)Br and CF(3)I, evidence was found for the formation of C-XS halogen bonded 1:1 complexes. At higher concentrations of CF(3)I weak absorptions due to a 2:1 complex were also observed. Using spectra recorded at temperatures between 118 and 163 K, the complexation enthalpies for the complexes were determined to be -9.5(5) kJ mol(-1) for CF(3)Br·DMS, -17.4(1) kJ mol(-1) for CF(3)I·DMS and -30.8(16) kJ mol(-1) for (CF(3)I·)(2)DMS. The results from the cryospectroscopic study are compared with ab initio calculations at the MP2/aug-cc-pVDZ(-PP) level. Apart from vibrational modes localized in the trifluorohalomethanes and the DMS moieties, for both CF(3)Br and CF(3)I, an additional band, which we assign as the intermolecular stretching mode in the complex, was identified in the infrared and Raman spectra. PMID:21509375

Hauchecorne, Dieter; Moiana, Alessio; van der Veken, Benjamin J; Herrebout, Wouter A

2011-06-01

297

Communication: Theoretical prediction of the importance of the {sup 3}B{sub 2} state in the dynamics of sulfur dioxide  

SciTech Connect

Even though the sulfur dioxide molecule has been extensively studied over the last decades, its photo-excitation dynamics is still unclear, due to its complexity, combining conical intersections, and spin-orbit coupling between a manifold of states. We present a comprehensive ab initio study of the intersystem crossing of the molecule in the low energy domain, based on a wave-packet propagation on the manifold of the lowest singlet and triplet states. Furthermore, spin-orbit couplings are evaluated on a geometry-dependent grid, and diabatized along with the different conical intersections. Our results show for the first time the primordial role of the triplet {sup 3}B{sub 2} state and furthermore predict novel interference patterns due to the different intersystem crossing channels induced by the spin-orbit couplings and the shapes of the different potential energy surfaces. These give new insight into the coupled singlet-triplet dynamics of SO{sub 2}.

Lévźque, Camille [Sorbonne Universités, UPMC Univ. Paris 06, Laboratoire de Chimie Physique-Matičre et Rayonnement, UMR 7614, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France) [Sorbonne Universités, UPMC Univ. Paris 06, Laboratoire de Chimie Physique-Matičre et Rayonnement, UMR 7614, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France); CNRS, LCPMR, UMR 7614, Paris Cedex 05 (France); Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg (Germany); Taļeb, Richard [Sorbonne Universités, UPMC Univ. Paris 06, Laboratoire de Chimie Physique-Matičre et Rayonnement, UMR 7614, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France) [Sorbonne Universités, UPMC Univ. Paris 06, Laboratoire de Chimie Physique-Matičre et Rayonnement, UMR 7614, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France); CNRS, LCPMR, UMR 7614, Paris Cedex 05 (France); Köppel, Horst [Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg (Germany)] [Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg (Germany)

2014-03-07

298

Combining Organometallic Reagents, the Sulfur Dioxide Surrogate DABSO, and Amines: A One-Pot Preparation of Sulfonamides, Amenable to Array Synthesis.  

PubMed

We describe a method for the synthesis of sulfonamides through the combination of an organometallic reagent, a sulfur dioxide equivalent, and an aqueous solution of an amine under oxidative conditions (bleach). This simple reaction protocol avoids the need to employ sulfonyl chloride substrates, thus removing the limitation imposed by the commercial availability of these reagents. The resultant method allows access to new chemical space, and is also tolerant of the polar functional groups needed to impart favorable physiochemical properties required for medicinal chemistry and agrochemistry. The developed chemistry is employed in the synthesis of a targeted 70 compound array, prepared using automated methods. The array achieved a 93?% success rate for compounds prepared. Calculated molecular weights, lipophilicities, and polar surface areas are presented, demonstrating the utility of the method for delivering sulfonamides with drug-like properties. PMID:25431118

Deeming, Alex S; Russell, Claire J; Willis, Michael C

2015-01-19

299

The formation of acid rain in the atmosphere, adjacent to the TTP with the joint-condensing of sulfur dioxide and water vapor  

NASA Astrophysics Data System (ADS)

Presents the results of mathematical simulation of the condensation process of sulphur dioxide and water vapor on the condensation nuclei surface under the action of natural factors. Numerical investigations were carried out for the summer at a moderate speed of the wind. The influence of the parameter of condensation on the speed of the process of sulfuric acid drops formation in the air space was analyzed. Time ranges, sufficient for the formation of the acid rain sedimentation in the atmosphere, adjacent to the areas of thermal power station work were established. It is shown that the speed of air masses movement effects on the process of acid anthropogenic admixtures dispersion in the atmosphere. Approbation of the obtained results was carried out by checking the difference scheme conservative and solution of test problems.

Gvozdyakov, D. V.; Gubin, V. E.; Matveeva, A. A.

2014-08-01

300

Combining Organometallic Reagents, the Sulfur Dioxide Surrogate DABSO, and Amines: A One-Pot Preparation of Sulfonamides, Amenable to Array Synthesis**  

PubMed Central

We describe a method for the synthesis of sulfonamides through the combination of an organometallic reagent, a sulfur dioxide equivalent, and an aqueous solution of an amine under oxidative conditions (bleach). This simple reaction protocol avoids the need to employ sulfonyl chloride substrates, thus removing the limitation imposed by the commercial availability of these reagents. The resultant method allows access to new chemical space, and is also tolerant of the polar functional groups needed to impart favorable physiochemical properties required for medicinal chemistry and agrochemistry. The developed chemistry is employed in the synthesis of a targeted 70 compound array, prepared using automated methods. The array achieved a 93?% success rate for compounds prepared. Calculated molecular weights, lipophilicities, and polar surface areas are presented, demonstrating the utility of the method for delivering sulfonamides with drug-like properties. PMID:25431118

Deeming, Alex S; Russell, Claire J; Willis, Michael C

2015-01-01

301

An acid-stable Zn(II) complex: electrodeposition in sulfuric acid and the effect on the zinc-lead dioxide battery.  

PubMed

An acid-stable Zn(II) complex formulated as Zn2(HL)2(SO4)·H2O (1) and an acid-unstable complex formulated as Zn2L2·12H2O (2) were hydro(solvo)thermally synthesized and structurally characterized by single-crystal X-ray diffraction. Complex 1 features a uninodal 6-connected 2-fold interpenetrating three-dimensional (3D) dense architecture with {4(12)·6(3)}-pcu topology, and complex 2 exhibits a 2-nodal (3, 6)-connected 3D open architecture with (4·6(2))2(4(2)·6(10)·8(3))-rtl topology. The results indicate that the stability of complex 1 in sulfuric acid is probably associated with the coordinated SO4(2-) in the quite dense structure, and complex 1 can also be synthesized via electrodeposition in sulfuric acid; it can improve the discharging characteristics of the zinc-lead dioxide battery at room temperature. PMID:25312385

Zhang, Miao Miao; Gong, Yun; Zhang, Pan; Shi, Hui Fang; Lin, Jian Hua

2014-12-01

302

Bonding interactions between sulfur dioxide (SO?) and mono-ruthenium(II)-substituted Keggin-type polyoxometalates: electronic structures of ruthenium-SO? adducts.  

PubMed

Density functional theory (DFT) calculations and natural bond orbital (NBO) analysis were carried out to investigate the electronic structures and bonding features between the ruthenium(ii) atom and the SO2 molecule in two ruthenium-sulfur dioxide (SO2) adducts, trans-Ru(NH3)4(SO2)Cl(+) and [{SiW11O39}Ru(II)(SO2)](6-). In addition, the bonding interactions between SO2 and the metal-ruthenium fragment were determined by binding energy (?Eabs) calculation and electronic structures. The results indicate that the ?(1)-S-planar model in both trans-Ru(NH3)4(SO2)Cl(+) and [{SiW11O39}Ru(II)(SO2)](6-) are more favorable. NBO analysis of the bonding interaction between ruthenium and sulfur centers in the [{SiW11O39}Ru(II)(SO2)](6-) complex shows that it possesses a ? and a ? bond. It predicts that the polyoxometalate [SiW11O39Ru](6-) can serve as a potential adsorbent for the SO2 molecule because of the strong Ru-S bond relative to Ru(NH3)4Cl(+). PMID:25050910

Zhu, Bo; Lang, Zhong-Ling; Ma, Na-Na; Yan, Li-Kai; Su, Zhong-Min

2014-09-01

303

Dimethyl Disulfide Produced by the Naturally Associated Bacterium Bacillus sp B55 Promotes Nicotiana attenuata Growth by Enhancing Sulfur Nutrition[W  

PubMed Central

Bacillus sp B55, a bacterium naturally associated with Nicotiana attenuata roots, promotes growth and survival of wild-type and, particularly, ethylene (ET)–insensitive 35S-ethylene response1 (etr1) N. attenuata plants, which heterologously express the mutant Arabidopsis thaliana receptor ETR1-1. We found that the volatile organic compound (VOC) blend emitted by B55 promotes seedling growth, which is dominated by the S-containing compound dimethyl disulfide (DMDS). DMDS was depleted from the headspace during cocultivation with seedlings in bipartite Petri dishes, and 35S was assimilated from the bacterial VOC bouquet and incorporated into plant proteins. In wild-type and 35S-etr1 seedlings grown under different sulfate (SO4?2) supply conditions, exposure to synthetic DMDS led to genotype-dependent plant growth promotion effects. For the wild type, only S-starved seedlings benefited from DMDS exposure. By contrast, growth of 35S-etr1 seedlings, which we demonstrate to have an unregulated S metabolism, increased at all SO4?2 supply rates. Exposure to B55 VOCs and DMDS rescued many of the growth phenotypes exhibited by ET-insensitive plants, including the lack of root hairs, poor lateral root growth, and low chlorophyll content. DMDS supplementation significantly reduced the expression of S assimilation genes, as well as Met biosynthesis and recycling. We conclude that DMDS by B55 production is a plant growth promotion mechanism that likely enhances the availability of reduced S, which is particularly beneficial for wild-type plants growing in S-deficient soils and for 35S-etr1 plants due to their impaired S uptake/assimilation/metabolism. PMID:23903320

Meldau, Dorothea G.; Meldau, Stefan; Hoang, Long H.; Underberg, Stefanie; Wünsche, Hendrik; Baldwin, Ian T.

2013-01-01

304

Temperature and solvation-dependent dynamics of liquid sulfur dioxide studied through the ultrafast optical Kerr effect  

Microsoft Academic Search

The ultrafast dynamics of liquid sulphur dioxide have been studied over a wide temperature range and in solution. The optically heterodyne-detected and spatially masked optical Kerr effect (OKE) has been used to record the anisotropic and isotropic third-order responses, respectively. Analysis of the anisotropic response reveals two components, an ultrafast nonexponential relaxation and a slower exponential relaxation. The slower component

Andrew A. Jaye; Neil T. Hunt; Stephen R. Meech

2006-01-01

305

40 CFR Appendix T to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur...  

Code of Federal Regulations, 2012 CFR

...National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) T Appendix...National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) 1. General...national ambient air quality standards for Oxides of Sulfur as measured by Sulfur...

2012-07-01

306

Formation of methane sulfinic acid in the gas-phase OH-radical initiated oxidation of dimethyl sulfoxide.  

PubMed

Dimethyl sulfoxide (CH3S(O)CH3: DMSO) is an important product of dimethyl sulfide (CH3SCH3: DMS) photooxidation. The mechanism of the OH-radical initiated oxidation of DMSO is still highly uncertain and a major aim of recent studies has been to establish if methane sulfinic acid (CH3S(O)OH: MSIA) is a major reaction product In the present work the products of the OH-radical gas-phase oxidation of dimethyl sulfoxide have been investigated in the absence and presence of NOx All experiments were performed in a 1,080 L reaction chamber in 1,000 mbar synthetic air at 284 +/- 2 K using long-path FT-IR spectroscopy and ion chromatography to monitor and quantify reactants and reaction products. Formation of methane sulfinic acid in high yield (80-99%) was observed in both in the absence and presence of NOx, and the results support that it is the major primary reaction product Other products observed included dimethyl sulfone (CH3S(O)2CH3: DMSO2), sulfur dioxide (SO2), methane sulfonic acid (CH3S(O)2OH: MSA), and methane sulfonyl peroxynitrate (CH3S(O)2OONO2: MSPN). The formation behavior of these products is in line with their source being mainly secondary production via oxidation of a primary product, i.e. MSIA. PMID:12523433

Arsene, Cecilia; Barnes, Ian; Becker, Karl H; Schneider, William F; Wallington, Timothy T; Mihalopoulos, Nikolaos; Patroescu-Klotz, Iulia V

2002-12-01

307

Headspace thin-film microextraction coupled with surface-enhanced Raman scattering as a facile method for reproducible and specific detection of sulfur dioxide in wine.  

PubMed

By coupling thin-film microextraction (TFME) with surface-enhanced Raman scattering (SERS), a facile method was developed for the determination of sulfur dioxide (SO2), the most effective food additive in winemaking technology. The TFME substrate was made by free settling of sea urchin-like ZnO nanomaterials on a glass sheet. The headspace sampling (HS) procedure for SO2 was performed in a simple homemade device, and then the SO2 was determined using SERS after uniformly dropping or spraying a SERS-active substrate (gold nanoparticles, AuNPs) onto the surface of the TFME substrate. A reproducible and strong SERS response of the SO2 absorbed onto the ZnO substrate was obtained. After condition optimization, the SERS signal intensity at a shift of 600 cm(-1) and the SO2 concentration showed a good linearity in the range of 1-200 ?g/mL, and the linear correlation coefficient was 0.992. The detection limit for SO2 was found to be 0.1 ?g/mL. The HS-TFME-SERS method was applied for the determination of SO2 in wine, and the results obtained agreed very well with those obtained using the traditional distillation and titration method. Analysis of variance and Student t test show that there is no significant difference between the two methods, indicating that the newly developed method is fast, convenient, sensitive and has selective characteristics in the determination of SO2 in wine. PMID:25415770

Deng, Zhuo; Chen, Xuexu; Wang, Yiru; Fang, Enhua; Zhang, Zhigang; Chen, Xi

2015-01-01

308

Endogeous sulfur dioxide protects against oleic acid-induced acute lung injury in association with inhibition of oxidative stress in rats.  

PubMed

The role of endogenous sulfur dioxide (SO2), an efficient gasotransmitter maintaining homeostasis, in the development of acute lung injury (ALI) remains unidentified. We aimed to investigate the role of endogenous SO2 in the pathogenesis of ALI. An oleic acid (OA)-induced ALI rat model was established. Endogenous SO2 levels, lung injury, oxidative stress markers and apoptosis were examined. OA-induced ALI rats showed a markedly downregulated endogenous SO2/aspartate aminotransferase 1 (AAT1)/AAT2 pathway and severe lung injury. Chemical colorimetry assays demonstrated upregulated reactive oxygen species generation and downregulated antioxidant capacity in OA-induced ALI rats. However, SO2 increased endogenous SO2 levels, protected against oxidative stress and alleviated ALI. Moreover, compared with OA-treated cells, in human alveolar epithelial cells SO2 downregulated O2(-) and OH(-) generation. In contrast, L-aspartic acid-?-hydroxamate (HDX, Sigma-Aldrich Corporation), an inhibitor of endogenous SO2 generating enzyme, promoted free radical generation, upregulated poly (ADP-ribose) polymerase expression, activated caspase-3, as well as promoted cell apoptosis. Importantly, apoptosis could be inhibited by the free radical scavengers glutathione (GSH) and N-acetyl-L-cysteine (NAC). The results suggest that SO2/AAT1/AAT2 pathway might protect against the development of OA-induced ALI by inhibiting oxidative stress. PMID:25581610

Chen, Siyao; Zheng, Saijun; Liu, Zhiwei; Tang, Chaoshu; Zhao, Bin; Du, Junbao; Jin, Hongfang

2015-02-01

309

Development of a gas diffusion multicommuted flow injection system for the determination of sulfur dioxide in wines, comparing malachite green and pararosaniline chemistries.  

PubMed

A flow system based on the multicommutation concept was developed for the determination of free and total sulfur dioxide in table wines, exploiting gas diffusion separation and spectrophotometric detection. The system allowed the comparison of malachite green and pararosaniline chemistries, using the same manifold configuration. Free and total SO(2) were determined within the ranges 1.00-40.0 and 25.0-250 mg L(-1), at determination throughputs of 25 and 23 h(-1), respectively. Employing the malachite green reaction, detection limits of 0.3 and 0.8 mg L(-1) were attained for free and total SO(2), respectively. Pararosaniline chemistry provided detection limits of 0.6 mg L(-1) for free SO(2) and 0.8 mg L(-1) for total SO(2). Relative standard deviations better than 1.8 and 1.4% were obtained by the malachite green and pararosaniline reactions, respectively. With regard to the two tested chemistries, 18 wines were analyzed and the results achieved by the pararosaniline reaction compared better with those furnished by the recommended procedure. PMID:19309149

Oliveira, Sara M; Lopes, Teresa I M S; Tóth, Ildikó V; Rangel, António O S S

2009-05-13

310

Technologies for the combined control of sulfur dioxide and nitrogen oxides emissions from coal-fired boilers  

SciTech Connect

The report discusses three projects completed under the US Clean Coal Technology Demonstration Program involving combined SO{sub 2} and NOx removal processes. These are: the SNOX{trademark} Flue Gas Cleaning demonstration project at Ohio Edison`s Niles Station, Unit 2 where high-sulfur bituminous coal was the fuel; the SO{sub x}-NOx-RoxBox{trademark} (SNRB{trademark}) Flue Gas Cleanup demonstrated at Ohio Edison`s R.E. Burger Plant, Unit No. 5; and the Integrated Dry NO{sub x}/SO{sub 2} Emissions Control System, demonstrated at Public Service Company of Colorado`s Aparahoe Station, Unit 4. The three projects address somewhat different commercial applications and all the technologies provide effective and innovative approaches to the combined control of these two air pollutants. The brochure describes the projects and includes explanations about the formation of NOx and SO{sub x} emission standards in the USA, and other NOx and SO{sub x} control technologies. 29 refs., 3 figs., 11 photos.

NONE

1999-05-15

311

Methods for removing malodorous sulfur compounds from pulp mill flue gases and the like by using green liquor  

SciTech Connect

This is an improved method for removing malodorous sulfur compounds from flue gases generated in kraft or sodium sulfite pulping operations and the like by the absorption process using green liquor, an aqueous solution containing sodium sulfide and sodium carbonate. The malodorous gas compounds, including hydrogen sulfide, methyl mercaptan, and dimethyl sulfide are preferentially absorbed by the sodium sulfide forming sodium hydrosulfide and methanol. Any sulfur dioxide in the gas is absorbed and neutralized by sodium carbonate. In this method carbon dioxide absorption is minimized and the formation of sodium bicarbonate is limited. Sodium bicarbonate formation is minimized in order to avoid its reaction with sodium hydrosulfide which would then release undesirable hydrogen sulfide during absorption, as well as to forestall the need to increase chemical and lime kiln capacity requirements when the green liquor returned to the kraft recovery process contains excess amounts of sodium bicarbonate.

Farin, W.G.

1984-02-14

312

Experimental Study of Closed System in the Chlorine Dioxide-Iodide-Sulfuric Acid Reaction by UV-Vis Spectrophotometric Method  

PubMed Central

The mole ratio r(r = [I?]0/[ClO2]0) has great influence on ClO2-I?-H2SO4 closed reaction system. By changing the initiate concentration of potassium iodide, the curve of absorbance along with the reaction time was obtained at 350?nm and 297?nm for triiodide ion, and 460?nm for iodine. The changing point of the absorbance curve's shape locates at r = 6.00. For the reaction of ClO2-I? in the absence of H2SO4, the curve of absorbance along with the reaction time can be obtained at 350?nm for triiodide ion, 460?nm for iodine. The mole ratio r is equal to 1.00 is the changing point of the curve's shape no matter at which wavelength to determine the reaction. For the reaction of ClO2-I?-H+ in different pH buffer solution, the curve of absorbance along with the reaction time was recorded at 460?nm for iodine. When r is greater than 1.00, the transition point of the curve's shape locates at pH 2.0, which is also the point of producing chlorite or chloride for chlorine dioxide at different pH. When r is less than 1.00, the transition point locates at pH 7.0. PMID:21808646

Li, Na; Shi, Laishun; Wang, Xiaomei; Guo, Fang; Yan, Chunying

2011-01-01

313

Sulfur dioxide and nitrogen oxides emissions from U.S. pulp and paper mills, 1980-2005  

SciTech Connect

Estimates of total SO{sub 2} and NOx emissions from U.S. pulp and paper mills were developed from industry-wide surveys conducted at 5-yr intervals from 1980 to 2005. The following conclusions were drawn from these estimates: (1) Total SO{sub 2} emissions from pulp and paper mills were 340,000 t in 2005. Since 1980, SO{sub 2} emissions have decreased steadily. The decline over the 25-yr period was over 60%. Paper production increased by 50% over the same period. (2) Boilers burning coal and oil are the primary source of SO{sub 2} emissions, with minor contributions from black liquor combustion in kraft recovery furnaces and the burning of noncondensable gases in boilers at kraft pulp mills. Factors contributing to the decline in boiler SO{sub 2} emissions include large reductions in residual oil use, recent decreases in coal use, declines in the average sulfur content of residual oil and coal being burned, and increasing use of flue gas desulfurization systems.(3) NOx emissions from pulp and paper mills were 230,000 t in 2005. NOx emissions were fairly constant through 1995, but then declined by 12% in 2000 and an additional 17% between 2000 and 2005. (4) In 2005, boilers accounted for two-thirds of the NOx emissions, and kraft mill sources approximately 30%. Boiler NOx emissions exhibited very little change through 1995, but decreased by one third in the next 10 yr. The lower emissions resulted from declines in fossil fuel use, a reduction in the EPA emission factors for natural gas combustion in boilers without NOx controls, and more widespread use of combustion modifications and add-on NOx control technologies, particularly on coal-fired boilers subject to EPA's NOx SIP call. Total NOx emissions from kraft mill sources changed little over the 25-yr period. 7 refs., 4 figs., 3 tabs.

John E. Pinkerton [National Council of the Paper Industry for Air and Stream Improvement Inc., Research Triangle Park, NC (United States). Air Quality Program

2007-08-15

314

Pulmonary excretion of hydrogen sulfide, methanethiol, dimethyl sulfide and dimethyl disulfide in mice.  

PubMed

Neither hydrogen sulfide nor any other volatile sulfur metabolites were found in the expired breath of mice given sodium sulfide intraperitoneally in doses up to the LD50. The detection system was sensitive to less than 0.1% of the sulfur in the given dose. The intraperitoneal administration of dimethyl disulfide resulted in its appearance in the expired breath of mice as well as much smaller amounts of both methanethiol and dimethyl sulfide. The intraperitoneal administration of methanethiol resulted in its pulmonary excretion as well as that of dimethyl sulfide. Administration of dimethyl sulfide led to its appearance alone in expired breath. Mice pretreated with ammonium acetate and then injected with dimethyl disulfide excreted the same three compounds via the lungs as above, but there were complex changes in the proportions and in the time sequence of their appearance. The absolute amounts of all three were increased, and the peak excretion for each was delayed. The amount excreted as dimethyl sulfide was particularly increased. PMID:755673

Susman, J L; Hornig, J F; Thomae, S C; Smith, R P

1978-01-01

315

Studies on air pollution: Effects of nitrogen dioxide on airway caliber and reactivity in asthmatic subjects; effects of nitrogen dioxide on lung lymphocytes and macrophage products in healthy subjects; nasal and bronchial effects of sulfur dioxide in asthmatic subjects. Final report, 26 June 1987-26 November 1988  

SciTech Connect

The investigators performed three studies of the effects of NO/sub 2/ and SO/sub 2/ on airway function in human subjects. In 9 exercising asthmatic subjects, a 30-min exposure to 0.3 ppm nitrogen dioxide did not alter specific airway resistance, maximal expiratory flow, or the slope of phase III on the single breath test of nitrogen distribution and had no effect on airway hyperresponsiveness to sulfur dioxide. In the second study, repeated exposure of 5 healthy subjects to nitrogen dioxide was associated neither with any significant change in pulmonary function nor in the levels of secretory product of lung macrophages in bronchoalveolar lavage fluid. Analysis of the numbers and types of lymphocytes in venous blood and bronchoalveolar lavage fluid revealed no change apart from a small, possibly artifactual increase in natural killer cells in bronchoalveolar lavage fluid after NO/sub 2/ exposure. The third study examined whether brief exposures to moderately high concentrations of SO/sub 2/ caused acute increases in nasal symptoms and nasal resistance in 8 subjects with a history of both asthma and allergic rhinitis and with demonstrable bronchial hyperreactivity to SO/sub 2/.

Boushey, H.A.; Rubinstein, I.; Bigby, B.G.

1988-12-13

316

A novel lithium/sulfur battery based on sulfur/graphene nanosheet composite cathode and gel polymer electrolyte.  

PubMed

A novel sulfur/graphene nanosheet (S/GNS) composite was prepared via a simple ball milling of sulfur with commercial multi-layer graphene nanosheet, followed by a heat treatment. High-resolution transmission and scanning electronic microscopy observations showed the formation of irregularly interlaced nanosheet-like structure consisting of graphene with uniform sulfur coating on its surface. The electrochemical properties of the resulting composite cathode were investigated in a lithium cell with a gel polymer electrolyte (GPE) prepared by trapping 1 mol dm-3 solution of lithium bistrifluoromethanesulfonamide in tetraethylene glycol dimethyl ether in a polymer matrix composed of poly(vinylidene fluoride-co-hexafluoropropylene)/poly(methylmethacrylate)/silicon dioxide (PVDF-HFP/PMMA/SiO2). The GPE battery delivered reversible discharge capacities of 809 and 413 mAh g-1 at the 1st and 50th cycles at 0.2C, respectively, along with a high coulombic efficiency over 50 cycles. This performance enhancement of the cell was attributed to the suppression of the polysulfide shuttle effect by a collective effect of S/GNS composite cathode and GPE, providing a higher sulfur utilization. PMID:24655466

Zhang, Yongguang; Zhao, Yan; Bakenov, Zhumabay

2014-01-01

317

A novel lithium/sulfur battery based on sulfur/graphene nanosheet composite cathode and gel polymer electrolyte  

NASA Astrophysics Data System (ADS)

A novel sulfur/graphene nanosheet (S/GNS) composite was prepared via a simple ball milling of sulfur with commercial multi-layer graphene nanosheet, followed by a heat treatment. High-resolution transmission and scanning electronic microscopy observations showed the formation of irregularly interlaced nanosheet-like structure consisting of graphene with uniform sulfur coating on its surface. The electrochemical properties of the resulting composite cathode were investigated in a lithium cell with a gel polymer electrolyte (GPE) prepared by trapping 1 mol dm-3 solution of lithium bistrifluoromethanesulfonamide in tetraethylene glycol dimethyl ether in a polymer matrix composed of poly(vinylidene fluoride-co-hexafluoropropylene)/poly(methylmethacrylate)/silicon dioxide (PVDF-HFP/PMMA/SiO2). The GPE battery delivered reversible discharge capacities of 809 and 413 mAh g-1 at the 1st and 50th cycles at 0.2C, respectively, along with a high coulombic efficiency over 50 cycles. This performance enhancement of the cell was attributed to the suppression of the polysulfide shuttle effect by a collective effect of S/GNS composite cathode and GPE, providing a higher sulfur utilization. PACS: 82.47.Aa; 82.45.Gj; 62.23.Kn

Zhang, Yongguang; Zhao, Yan; Bakenov, Zhumabay

2014-03-01

318

Attribution of primary formaldehyde and sulfur dioxide at Texas City during SHARP/formaldehyde and olefins from large industrial releases (FLAIR) using an adjoint chemistry transport model  

NASA Astrophysics Data System (ADS)

adjoint version of the Houston Advanced Research Center (HARC) neighborhood air quality model with 200 m horizontal resolution, coupled offline to the Quick Urban & Industrial Complex (QUIC-URB) fast response urban wind model, was used to perform 4-D variational (4Dvar) inverse modeling of an industrial release of formaldehyde (HCHO) and sulfur dioxide (SO2) in Texas City, Texas during the 2009 Study of Houston Atmospheric Radical Precursors (SHARP). The source attribution was based on real-time observations by the Aerodyne mobile laboratory and a high resolution 3-D digital model of the emitting petrochemical complex and surrounding urban canopy. The inverse model estimate of total primary HCHO emitted during the incident agrees very closely with independent remote sensing estimates based on both Imaging and Multi-Axis Differential Optical Absorption Spectroscopy (DOAS). Whereas a previous analysis of Imaging DOAS data attributed the HCHO release to a Fluidized Catalytic Cracking Unit (FCCU), the HARC model attributed most of the HCHO event emissions to both the FCCU and desulfurization processes. Fugitives contributed significantly to primary HCHO, as did combustion processes, whereas the latter accounted for most SO2 event emissions. The inferred HCHO-to-SO2 molar emission ratio was similar to that computed directly from ambient air measurements during the release. The model-estimated HCHO-to-CO molar emission ratio for combustion units with significant inferred emissions ranged from 2% to somewhat less than 7%, consistent with other observationally-based estimates obtained during SHARP. A model sensitivity study demonstrated that the inclusion of urban morphology has a significant, but not critical, impact on the source attribution.

Olaguer, Eduardo P.; Herndon, Scott C.; Buzcu-Guven, Birnur; Kolb, Charles E.; Brown, Michael J.; Cuclis, Alex E.

2013-10-01

319

A complete listing of sulfur dioxide self-broadening coefficients for atmospheric applications by coupling infrared and microwave spectroscopy to semiclassical calculations  

NASA Astrophysics Data System (ADS)

Sulfur dioxide (SO2) is a molecule of proved atmospheric relevance, the main sources being anthropogenic, which is one of the main causes of acid rains. Besides, it is also of interest in astrophysics, as it is present in the atmosphere of Venus and in star forming regions. For these reasons SO2 is one of the target molecules in all of the most important spectroscopic databases which collect the spectroscopic line-by-line parameters for atmospheric remote sensing, astrophysics soundings, and climate changing investigations. Although over the years the spectroscopic properties of this molecule have been widely studied, and line-by-line listings of line positions and intensities have been compiled, at present an analogous systematic and complete database of broadening coefficients is still lacking. The aim of this work is to fill in this vacancy, starting from self-broadening coefficients, by coupling experimental measurements to theoretical calculations. The laboratory experiments are carried out for 12 pure rotational transitions of the vibrational ground state (and 2 of vibrational excited states) and for 25 ro-vibrational lines of the ?1 band, lying in the 9 ?m atmospheric window. Theoretical calculations of broadening coefficients are performed employing a semiclassical formalism based on the ATC (Anderson-Tsao-Curnutte) approximation. From the interplay between theory and experiment the vibrational and quantum number dependence of the collisional cross-sections is first assessed and studied and then a complete database of self-broadening coefficients for 1635 transitions in a wide quantum number range (0?K?a?16, 2?J??68) is compiled, presented and made available.

Tasinato, Nicola; Charmet, Andrea Pietropolli; Stoppa, Paolo; Buffa, Giovanni; Puzzarini, Cristina

2013-11-01

320

Dimethyl sulfide and its oxidation products in the atmosphere of the Atlantic and Southern Oceans  

NASA Astrophysics Data System (ADS)

Dimethyl sulfide, methane sulfonate, non-sea-salt sulfate and sulfur dioxide concentrations in air were obtained during a cruise between the U.K. and the Antarctic during the period October 1992-January 1993. In equatorial regions (30°N to 30°S) the atmospheric DMS concentration ranged from 3 to 46 ng (S)m -3 with an average of 18 ng(S)m -3. In the polar waters and regions south of the Falkland Islands concentrations from 3 to 714ng(S)m -3 were observed with a mean concentration of 73ng(S)m -3. Methane sulfonate concentrations were also enhanced in the vicinity of the Antarctic Peninsula and in the Weddell Sea. A simple model of DMS oxidation was used to estimate the ocean to atmosphere flux rate, and this was found to be within the range of previous estimates, with a mean value of 1011 ng(S) m -2 h -1.

Davison, B.; O'dowd, C.; Hewitt, C. N.; Smith, M. H.; Harrison, R. M.; Peel, D. A.; Wolf, E.; Mulvaney, R.; Schwikowski, M.; Baltenspergert, U.

321

Removal of dimethyl sulfide by the combination of non-thermal plasma and biological process.  

PubMed

A bench scale system integrated with a non-thermal plasma (NTP) and a biotricking filtration (BTF) unit for the treatment of gases containing dimethyl sulfide (DMS) was investigated. DMS removal efficiency in the integrated system was up to 96%. Bacterial communities in the BTF were assessed by PCR-DGGE, which play the dominant role in the biological processes of metabolism, sulfur oxidation, sulfate-reducing and carbon oxidation. The addition of ozone from NTP made microbial community in BTF more complicated and active for DMS removal. The NTP oxidize DMS to simple compounds such as methanol and carbonyl sulfide; the intermediate organic products and DMS are further oxidized to sulfate, carbon dioxide, water vapors by biological degradation. These results show that NTP-BTF is achievable and open new possibilities for applying the integrated with NTP and BTF to odour gas treatment. PMID:23954717

Wei, Z S; Li, H Q; He, J C; Ye, Q H; Huang, Q R; Luo, Y W

2013-10-01

322

Thermodynamic equilibrium calculations of dimethyl ether steam reforming and dimethyl ether hydrolysis  

NASA Astrophysics Data System (ADS)

The production of a hydrogen-rich fuel-cell feed by dimethyl ether (DME) steam reforming was investigated using calculations of thermodynamic equilibrium as a function of steam-to-carbon ratio (0.00-4.00), temperature (100-600 °C), pressure (1-5 atm), and product species. Species considered were acetone, acetylene, carbon dioxide, carbon monoxide, dimethyl ether, ethane, ethanol, ethylene, formaldehyde, formic acid, hydrogen, isopropanol, methane, methanol, methyl-ethyl ether, n-propanol and water. Thermodynamic equilibrium calculations of DME steam reforming indicate complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide at temperatures greater than 200 °C and steam-to-carbon ratios greater than 1.25 at atmospheric pressure ( P = 1 atm). Increasing the operating pressure shifts the equilibrium toward the reactants; increasing the pressure from 1 to 5 atm decreases the conversion of dimethyl ether from 99.5 to 76.2%. The trend of thermodynamically stable products in decreasing mole fraction is methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol, methyl-ethyl ether and methanol-formaldehyde, formic acid, and acetylene were not observed. Based on the equilibrium calculations, the optimal processing conditions for dimethyl ether steam reforming occur at a steam-to-carbon ratio of 1.50, a pressure of 1 atm, and a temperature of 200 °C. These thermodynamic equilibrium calculations show dimethyl ether processed with steam will produce hydrogen-rich fuel-cell feeds—with hydrogen concentrations exceeding 70%. The conversion of dimethyl ether via hydrolysis (considering methanol as the only product) is limited by thermodynamic equilibrium. Equilibrium conversion increases with temperature and steam-to-carbon ratio. A maximum dimethyl ether conversion of 62% is achieved at a steam-to-carbon ratio of 5.00 and a processing temperature of 600 °C.

Semelsberger, Troy A.; Borup, Rodney L.

323

Sulfur dioxide inhibits vascular smooth muscle cell proliferation via suppressing the Erk/MAP kinase pathway mediated by cAMP/PKA signaling  

PubMed Central

The present study was designed to investigate the role of endogenous sulfur dioxide (SO2) in vascular smooth muscle cell (VSMC) proliferation, and explore the possible role of cross-talk between cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) and extracellular signal-regulated kinase (Erk)/mitogen-activated protein kinase (MAPK) pathways in this action. By cell counting, growth curve depict, flow cytometry and bromodeoxyuridine (BrdU) labeling assays, we found that SO2 inhibited VSMC proliferation by preventing cell cycle progression from G1 to S phase and by reducing DNA synthesis. SO2 synthase aspartate aminotransferase (AAT1 and AAT2) overexpression significantly inhibited serum-induced proliferating cell nuclear antigen (PCNA) protein expression in VSMCs, demonstrated by western blot analysis. Moreover, overexpression of AAT1 or AAT2 markedly reduced incorporation of BrdU in serum-treated VSMCs. By contrast, either AAT1 or AAT2 knockdown significantly exacerbated serum-stimulated VSMC proliferation. Thus, both exogenous- and endogenous-derived SO2 suppressed serum-induced VSMC proliferation. However, annexin V-propidium iodide (PI) staining and cell cycle analysis demonstrated that SO2 did not influence VSMC apoptosis in the serum-induced proliferation model. In a platelet-derived growth factor (PDGF)-BB-stimulated VSMC proliferation model, SO2 dephosphorylated the active sites of Erk1/2, MAPK kinase 1/2 and RAF proto-oncogene serine/threonine-protein kinase (c-Raf) induced by PDGF-BB. However, the inactivation of the three kinases of the Erk/MAPK pathway was not due to the separate interferences on them by SO2 simultaneously, but a consequence of the influence on the upstream activity of the c-Raf molecule. Hence, we examined the cAMP/PKA pathway, which could inhibit Erk/MAPK transduction in VSMCs. The results showed that SO2 could stimulate the cAMP/PKA pathway to block c-Raf activation, whereas the Ser259 site on c-Raf had an important role in SO2-induced suppression of Erk/MAPK pathway. The present study firstly demonstrated that SO2 exerted a negative regulation of VSMC proliferation via suppressing the Erk/MAPK pathway mediated by cAMP/PKA signaling. PMID:24853429

Liu, D; Huang, Y; Bu, D; Liu, A D; Holmberg, L; Jia, Y; Tang, C; Du, J; Jin, H

2014-01-01

324

Sulfur dioxide inhibits vascular smooth muscle cell proliferation via suppressing the Erk/MAP kinase pathway mediated by cAMP/PKA signaling.  

PubMed

The present study was designed to investigate the role of endogenous sulfur dioxide (SO2) in vascular smooth muscle cell (VSMC) proliferation, and explore the possible role of cross-talk between cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) and extracellular signal-regulated kinase (Erk)/mitogen-activated protein kinase (MAPK) pathways in this action. By cell counting, growth curve depict, flow cytometry and bromodeoxyuridine (BrdU) labeling assays, we found that SO2 inhibited VSMC proliferation by preventing cell cycle progression from G1 to S phase and by reducing DNA synthesis. SO2 synthase aspartate aminotransferase (AAT1 and AAT2) overexpression significantly inhibited serum-induced proliferating cell nuclear antigen (PCNA) protein expression in VSMCs, demonstrated by western blot analysis. Moreover, overexpression of AAT1 or AAT2 markedly reduced incorporation of BrdU in serum-treated VSMCs. By contrast, either AAT1 or AAT2 knockdown significantly exacerbated serum-stimulated VSMC proliferation. Thus, both exogenous- and endogenous-derived SO2 suppressed serum-induced VSMC proliferation. However, annexin V-propidium iodide (PI) staining and cell cycle analysis demonstrated that SO2 did not influence VSMC apoptosis in the serum-induced proliferation model. In a platelet-derived growth factor (PDGF)-BB-stimulated VSMC proliferation model, SO2 dephosphorylated the active sites of Erk1/2, MAPK kinase 1/2 and RAF proto-oncogene serine/threonine-protein kinase (c-Raf) induced by PDGF-BB. However, the inactivation of the three kinases of the Erk/MAPK pathway was not due to the separate interferences on them by SO2 simultaneously, but a consequence of the influence on the upstream activity of the c-Raf molecule. Hence, we examined the cAMP/PKA pathway, which could inhibit Erk/MAPK transduction in VSMCs. The results showed that SO2 could stimulate the cAMP/PKA pathway to block c-Raf activation, whereas the Ser259 site on c-Raf had an important role in SO2-induced suppression of Erk/MAPK pathway. The present study firstly demonstrated that SO2 exerted a negative regulation of VSMC proliferation via suppressing the Erk/MAPK pathway mediated by cAMP/PKA signaling. PMID:24853429

Liu, D; Huang, Y; Bu, D; Liu, A D; Holmberg, L; Jia, Y; Tang, C; Du, J; Jin, H

2014-01-01

325

Sulfur dioxide (SO2) as observed by MIPAS/Envisat: temporal development and spatial distribution at 15-45 km altitude  

NASA Astrophysics Data System (ADS)

We present a climatology of monthly and 10° zonal mean profiles of sulfur dioxide (SO2) volume mixing ratios (vmr) derived from MIPAS/Envisat measurements in the altitude range 15-45 km from July 2002 until April 2012. The vertical resolution varies from 3.5-4 km in the lower stratosphere up to 6-10 km at the upper end of the profiles with estimated total errors of 5-20 pptv for single profiles of SO2. Comparisons with few available observations of SO2 up to high altitudes from ATMOS, for a volcanically perturbed situations from ACE-FTS and, at the lowest altitudes, with stratospheric in-situ observations reveal general consistency of the datasets. The observations are the first empirical confirmation of features of the stratospheric SO2 distribution which have only been shown by models up to now: (1) the local maximum of SO2 at around 25-30 km altitude which is explained by the conversion of carbonyl sulfide (COS) as the precursor of the Junge layer, and (2) the downwelling of SO2 rich air to altitudes of 25-30 km at high latitudes during winter and its subsequent depletion on availability of sunlight. This has been proposed as the reason for the sudden appearance of enhanced concentrations of condensation nuclei during Arctic and Antarctic spring. Further, the strong increase of SO2 to values of 80-100 pptv in the upper stratosphere through photolysis of H2SO4 has been confirmed. Lower stratospheric variability of SO2 could mainly be explained by volcanic activity and no hint for a strong anthropogenic influence has been found. Regression analysis revealed a QBO (quasi-biennial oscillation) signal of the SO2 time series in the tropics at about 30-35 km, a SAO (semi-annual oscillation) signal at tropical and subtropical latitudes above 32 km and annual periodics predominantly at high latitudes. Further, the analysis indicates a correlation with the solar cycle in the tropics and southern subtropics above 30 km. Significant negative linear trends are found in the tropical lower stratosphere, probably due to reduced tropical volcanic activity and at southern mid-latitudes above 35 km. A positive trend is visible in the lower and middle stratosphere at polar to subtropical southern latitudes.

Höpfner, M.; Glatthor, N.; Grabowski, U.; Kellmann, S.; Kiefer, M.; Linden, A.; Orphal, J.; Stiller, G.; von Clarmann, T.; Funke, B.

2013-05-01

326

Sulfur dioxide (SO2) as observed by MIPAS/Envisat: temporal development and spatial distribution at 15-45 km altitude  

NASA Astrophysics Data System (ADS)

We present a climatology of monthly and 10° zonal mean profiles of sulfur dioxide (SO2) volume mixing ratios (vmr) derived from MIPAS/Envisat measurements in the altitude range 15-45 km from July 2002 until April 2012. The vertical resolution varies from 3.5-4 km in the lower stratosphere up to 6-10 km at the upper end of the profiles, with estimated total errors of 5-20 pptv for single profiles of SO2. Comparisons with the few available observations of SO2 up to high altitudes from ATMOS for a volcanically perturbed situation from ACE-FTS and, at the lowest altitudes, with stratospheric in situ observations reveal general consistency of the datasets. The observations are the first empirical confirmation of features of the stratospheric SO2 distribution, which have only been shown by models up to now: (1) the local maximum of SO2 at around 25-30 km altitude, which is explained by the conversion of carbonyl sulfide (COS) as the precursor of the Junge layer; and (2) the downwelling of SO2-rich air to altitudes of 25-30 km at high latitudes during winter and its subsequent depletion on availability of sunlight. This has been proposed as the reason for the sudden appearance of enhanced concentrations of condensation nuclei during Arctic and Antarctic spring. Further, the strong increase of SO2 to values of 80-100 pptv in the upper stratosphere through photolysis of H2SO4 has been confirmed. Lower stratospheric variability of SO2 could mainly be explained by volcanic activity, and no hints of a strong anthropogenic influence have been found. Regression analysis revealed a QBO (quasi-biennial oscillation) signal of the SO2 time series in the tropics at about 30-35 km, an SAO (semi-annual oscillation) signal at tropical and subtropical latitudes above 32 km and annual periodics predominantly at high latitudes. Further, the analysis indicates a correlation with the solar cycle in the tropics and southern subtropics above 30 km. Significant negative linear trends are found in the tropical lower stratosphere, probably due to reduced tropical volcanic activity and at southern mid-latitudes above 35 km. A positive trend is visible in the lower and middle stratosphere at polar to subtropical southern latitudes.

Höpfner, M.; Glatthor, N.; Grabowski, U.; Kellmann, S.; Kiefer, M.; Linden, A.; Orphal, J.; Stiller, G.; von Clarmann, T.; Funke, B.; Boone, C. D.

2013-10-01

327

The influence of government actions on innovative activities in the development of environmental technologies to control sulfur dioxide emissions from stationary sources  

NASA Astrophysics Data System (ADS)

A better understanding of the influence of government actions on innovation is needed to inform future policy endeavors in areas ranging from industrial competitiveness to environmentally sustainable growth. Environmental control technology is a rich area for the study of this influence, since government has stronger incentives to promote innovation in these technologies than does the private sector. This dissertation investigated the case of sulfur dioxide (SO2) control technologies for electric power plants. In studying innovation in these technologies, it was very important to understand the details of these technologies as well as their long organizational history. These technologies have been affected by government actions ranging from government-sponsored research and technology transfer mechanisms to national regulatory events. The dissertation integrated insights from several complementary and repeatable innovation evaluation methods; this approach supported a fuller understanding of innovation while it structured the research results for potential future comparative analysis. Innovative activities were investigated through: patent activity analysis; technical content analysis and researcher co-authorship network analysis in a conference held for over twenty years; learning curve analysis for eighty-eight U.S. power plants; and a dozen expert interviews from a variety of innovative actors. Innovative outcomes were investigated through: analysis of observed improvements in newly installed technologies over time; evaluation of historic cost studies on standardized systems; and expert interviews. Several policy-relevant findings resulted from this dissertation. (1) The existence of national government regulation stimulated inventive activity more than government research support alone. (2) The existence and the anticipation of government regulation appeared to spur inventive activity, while regulatory stringency appeared to drive inventive activity and the communication process underlying knowledge transfer and diffusion. (3) The regulatory-forced adoption of SO2 control technologies led to a learning curve effect in which operating experience with the equipment resulted in significant cost improvements. This learning curve effect is comparable with findings in many other industries and is likely to be useful in predictions of the costs of future environmental technologies. (4) Performance improvements and cost reductions occurred in a quantifiable fashion as the technology became more widely adopted.

Taylor, Margaret R.

2001-12-01

328

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

329

Method to prevent sulfur accumulation in membrane electrode assembly  

DOEpatents

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

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

2014-04-29

330

Method of detecting sulfur dioxide  

DOEpatents

(CH.sub.3).sub.3 SiNSO is produced by the reaction of ((CH.sub.3).sub.3 Si).sub.2 NH with SO.sub.2. Also produced in the reaction are ((CH.sub.3).sub.3 Si).sub.2 O and a new solid compound [NH.sub.4 ][(CH.sub.3).sub.3 SiOSO.sub.2 ]. Both (CH.sub.3).sub.3 SiNSO and [NH.sub.4 ][(CH.sub.3).sub.3 SiOSO.sub.2 ] have fluorescent properties. The reaction of the subject invention is used in a method of measuring the concentration of SO.sub.2 pollutants in gases. By the method, a sample of gas is bubbled through a solution of ((CH.sub.3).sub.3 Si).sub.2 NH, whereby any SO.sub.2 present in the gas will react to produce the two fluorescent products. The measured fluorescence of these products can then be used to calculate the concentration of SO.sub.2 in the original gas sample. The solid product [NH.sub.4][(CH.sub.3).sub.3 SiOSO.sub.2 ] may be used as a standard in solid state NMR spectroscopy.

Spicer, Leonard D. (Salt Lake City, UT); Bennett, Dennis W. (Clemson, SC); Davis, Jon F. (Salt Lake City, UT)

1985-01-01

331

Toxicology of sulfur in ruminants: review  

SciTech Connect

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

Kandylis, K.

1984-10-01

332

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. PMID:50930

Arnold, D R

1975-01-01

333

Observations of the atmospheric sulfur cycle on SAGA 3  

NASA Astrophysics Data System (ADS)

During the Soviet/American Gases and Aerosols (SAGA) 3 program in February and March 1991 we measured a wide variety of sulfur compounds simultaneously in the equatorial Pacific marine boundary layer. We made measurements of atmospheric dimethyl sulfide (DMS), sulfur dioxide (SO2), and size-resolved aerosol non-sea-salt sulfate (NSS), and methane sulfonate (MSA). Some of our observed ratios contradict commonly held views of the marine sulfur cycle: the large DMS/NSS ratio implies that NSS may not be the primary product of DMS oxidation under some conditions. We also found much more DMS than SO2, which may suggest that SO2 is not always an intermediate in DMS oxidation. The small SO2/NSS ratio also supports the idea that most NSS was not formed from SO2. Although our measured ratios of MSA/NSS were similar to previous observations in this region, much of the MSA was contained on supermicron particles, in contrast to both the NSS and the earlier MSA observations at higher latitudes. This implies that MSA/NSS ratios in ice cores may not accurately reflect the MSA/NSS ratios in their source areas.

Huebert, B. J.; Howell, S.; Laj, P.; Johnson, J. E.; Bates, T. S.; Quinn, P. K.; Yegorov, Vladimir; Clarke, A. D.; Porter, J. N.

1993-01-01

334

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

335

Sulfur and Sulfuric Acid  

NASA Astrophysics Data System (ADS)

Sulfur is one of the few elements that is found in its elemental form in nature. Typical sulfur deposits occur in sedimentary limestone/gypsum formations, in limestone/anhydrite formations associated with salt domes, or in volcanic rock.1 A yellow solid at normal temperatures, sulfur becomes progressively lighter in color at lower temperatures and is almost white at the temperature of liquid air. It melts at 114-119°C (depending on crystalline form) to a transparent light yellow liquid as the temperature is increased. The low viscosity of the liquid begins to rise sharply above 160°C, peaking at 93 Pa·s at 188°C, and then falling as the temperature continues to rise to its boiling point of 445°C. This and other anomalous properties of the liquid state are due to equilibria between the various molecular species of sulfur, which includes small chains and rings.

D'Aquin, Gerard E.; Fell, Robert C.

336

Geochemical and cosmochemical cycles involving sulfur, sulfide, sulfite and sulfate  

Microsoft Academic Search

Raman spectra of aqueous systems containing sulfur dioxide, elemental sulfur and sulfate indicate that the equilibrium between these species is catalyzed by elemental sulfur. Therefore, dynamic equilibrium can be expected under conditions prevalent on Venus, on Io and in epigenic sulfur deposits.

B. Meyer; L. Peter; M. Ospina

1979-01-01

337

DIMETHYL SULFOXIDE ACCELERATES MUSTARD GAS-INDUCED SKIN PATHOLOGY  

Microsoft Academic Search

SUMMARY Dimethyl sulfoxide (DMSO), when used as a percutaneous carrier or as a required solvent for drugs, may have modulating effects on drug mechanisms and untoward effects on subject tissues. In this collaborative study, anhydrous DMSO was used as a vehicle for peptide caspase inhibitors of sulfur mustard gas (HD)-induced apoptosis in hairless guinea pig skin. Results of the inhibition

John P. Petrali; Tracey A. Hamilton; Betty J. Benton; Dana R. Anderson; Wesley Holmes; Robert K. Kan; Christina P. Tompkins; Radharaman Ray

338

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

Microsoft Academic Search

An evaluation of the relative economics of hydrogen production using two advanced techniques was performed. The hydrogen production systems considered were the Westinghouse Sulfur Cycle Water Decomposition System and a water electrolysis system employing a sulfuric acid electrolyte. The former is a hybrid system in which hydrogen is produced in an electrolyzer which uses sulfur dioxide to depolarize the anode.

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

1978-01-01

339

Fructose metabolism of the purple non-sulfur bacterium Rhodospirillum rubrum: effect of carbon dioxide on growth, and production of bacteriochlorophyll and organic acids.  

PubMed

During fermentative metabolism, carbon dioxide fixation plays a key role in many bacteria regarding growth and production of organic acids. The present contribution, dealing with the facultative photosynthetic bacterium Rhodospirillum rubrum, reveals not only the strong influence of ambient carbon dioxide on the fermentative break-down of fructose but also a high impact on aerobic growth with fructose as sole carbon source. Both growth rates and biomass yield increased with increasing carbon dioxide supply in chemoheterotrophic aerobic cultures. Furthermore, intracellular metabolite concentration measurements showed almost negligible concentrations of the tricarboxylic acid cycle intermediates succinate, fumarate and malate under aerobic growth, in contrast to several metabolites of the glycolysis. In addition, we present a dual phase fed-batch process, where an aerobic growth phase is followed by an anaerobic production phase. The biosynthesis of bacteriochlorophyll and the secretion of organic acids were both affected by the carbon dioxide supply, the pH value and by the cell density at the time of switching from aerobic to anaerobic conditions. The formation of pigmented photosynthetic membranes and the amount of bacteriochlorophyll were inversely correlated to the secretion of succinate. Accounting the high biotechnological potential of R. rubrum, optimization of carbon dioxide supply is important because of the favored application of fructose-containing fermentable feedstock solutions in bio-industrial processes. PMID:22418264

Rudolf, Christiane; Grammel, Hartmut

2012-04-01

340

Mutual Antagonism of Sulfur Dioxide and Abscisic Acid in Their Effect on Stomatal Aperture in Broad Bean (Vicia faba L.) Epidermal Strips 1  

PubMed Central

Abscisic acid (ABA) was found to counteract the stomatal opening in Vicia faba L. caused by SO2. The antagonism between SO2 and ABA was mutual, and their combined effect depended upon which compound was in the greatest concentration. Stomatal apertures were monitored in detached epidermal strips floated in the light on aqueous solutions of SO2 (sulfurous acid) and/or ABA in 0.01 molar sodium citrate buffer (pH 5.8). Low concentrations of sulfurous acid (10?10 to 10?7 molar) increased stomatal aperture, but concentrations greater than 10?5 molar decreased it. A progressive decrease in aperture size occurred as ABA was increased from 10?10 to 10?5 molar. No evidence was found for a direct chemical reaction between the buffered sulfurous acid and ABA (exogenous or endogenous). Extractable, endogenous ABA in the strips remained relatively constant after exposure to several different concentrations of sulfurous acid. A technique for quantitating ABA from methanolic extracts of small samples of epidermis (20 milligrams dry weight) using reverse phase high performance liquid chromatography is described. PMID:16662135

Taylor, John S.; Reid, David M.; Pharis, Richard P.

1981-01-01

341

Sulfuric Acid Production on Europa: The Radiolysis of Sulfur in Water Ice  

Microsoft Academic Search

Europa's surface is chemically altered by radiolysis from energetic charged particle bombardment. It has been suggested that hydrated sulfuric acid (H2SO4·nH2O) is a major surface species and is part of a radiolytic sulfur cycle, where a dynamic equilibrium exists between continuous production and destruction of sulfur polymers Sx, sulfur dioxide SO2, hydrogen sulfide H2S, and H2SO4·nH2O. We measured the rate

R. W. Carlson; M. S. Anderson; R. E. Johnson; M. B. Schulman; A. H. Yavrouian

2002-01-01

342

Sulfuric Acid Production on Europa: The Radiolysis of Sulfur in Water Ice  

Microsoft Academic Search

Europa's surface is chemically altered by radiolysis from energetic charged particle bombardment. It has been suggested that hydrated sulfuric acid (H2SO4.nH2O) is a major surface species and is part of a radiolytic sulfur cycle, where a dynamic equilibrium exists between continuous production and destruction of sulfur polymers Sx, sulfur dioxide SO2, hydrogen sulfide H2S, and H2SO4.nH2O. We measured the rate

R. W. Carlson; M. S. Anderson; R. E. Johnson; M. B. Schulman; A. H. Yavrouian

2002-01-01

343

Chemolithotrophic nitrite oxidation by Nitrobacter: coupling with carbon dioxide fixation for growth and influence of metal ions and inorganic compounds of sulfur  

SciTech Connect

The growth of Nitrobacter winogradskyi was completely inhibited by 0.1 mM persulfate, 0.5 mM tetrathionate, or by 5 mM each of dithionite, metabisulfite, or trithionate. The oxygen uptake activity of washed N. agilis cell suspensions was not influenced by persulfate or tetrathionate. Carbon dioxide fixation was insensitive to tetrathionate and in fact an enhancement by tetrathionate was observed. Persulfate inhibited the fixation of carbon dioxide only at a high concentration. The oxygen uptake activity of washed ell suspensions of N. agilis was tested in the presence of copper, nickel, aluminum, uranyl, and molybdate ions. Copper ion was slightly stimulatory at 0.17 M and strongly inhibitory at 17 mM. Molybdate ion showed either slight enhancement or no inhibition at all test concentrations. With the other test ions inhibition of oxygen uptake was observed.

Tsai, Y.L.

1986-01-01

344

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

345

Removal of H{sub 2}S, methyl macapton dimethyl sulfide and dimethyl disulfide with biofiltration  

SciTech Connect

A pilot study describes the biofiltration process control that was necessary to remove H{sub 2}S, methyl mercaptan, dimethyl sulfide, and dimethyl disulfide, when mixed in an airstream. A pilot test at a waste water treatment facility was operated over a six month period. During that time H{sub 2}S was removed with very high efficiency at concentrations that reached to 400 ppm{sub v}; H{sub 2}S loading reached as high as 20 gms/m{sup 3}/hr. Methyl mercaptan and the organic sulfides were not removed sufficiently to deodorize the air-stream until a second stage biofilter was added. An odor analysis indicated that the odor detection level was approximately 250,000 odor units at the inlet and 1100 odor units at the outlet. The sulfur distribution in the media indicated that elemental sulfur and sulfate is deposited as a byproduct of the H{sub 2}S oxidation. Data from a fall scale biofilter treating H{sub 2}S from a pumping station is also presented. This data shows very efficient removal of H{sub 2}S, no organic reduced sulfur compounds were found in this air-stream.

Singleton, B.; Milligan, D.

1996-12-31

346

Sulfur production continues to rise  

SciTech Connect

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

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

1994-06-01

347

Inorganic Aerosols and Their Role in Catalyzing Sulfuric Acid Production in Furnaces  

Microsoft Academic Search

Submicrometer ash and sulfur oxides are important pollutants formed during pulverized coal combustion. The submicrometer ash contains known catalysts for sulfur dioxide oxidation as well as alkaline species that will react with sulfur oxides. This work was an investigation to determine if submicrometer ash-sulfur oxide interactions can have a significant impact on the fate of sulfur.The submicrometer-ash-sulfur oxide interaction studies

Karl A. Graham; Adel F. Sarofim

1998-01-01

348

Process for the manufacture of sulfur or sulfuric acid from coke oven gas  

Microsoft Academic Search

A process for the complete elimination of ammonia and hydrogen sulfide from coke oven gases is described which does not lead to the occurrence of sulfur dioxide-containing condensates as in prior-art methods. Most of the hydrogen sulfide combustion gases are cooled only to the point where elementary sulfur condenses out on the cooler bottom. The process initially involves scrubbing the

G. Wunderlich; H. Weber

1974-01-01

349

21 CFR 173.300 - Chlorine dioxide.  

Code of Federal Regulations, 2011 CFR

...chlorate with hydrogen peroxide in the presence of sulfuric acid. (iii) Treating an aqueous solution of sodium chlorite by electrolysis. (2) The generator effluent contains at least 90 percent (by weight) of chlorine dioxide with respect to all...

2011-04-01

350

21 CFR 173.300 - Chlorine dioxide.  

Code of Federal Regulations, 2013 CFR

...chlorate with hydrogen peroxide in the presence of sulfuric acid. (iii) Treating an aqueous solution of sodium chlorite by electrolysis. (2) The generator effluent contains at least 90 percent (by weight) of chlorine dioxide with respect to all...

2013-04-01

351

21 CFR 173.300 - Chlorine dioxide.  

Code of Federal Regulations, 2014 CFR

...chlorate with hydrogen peroxide in the presence of sulfuric acid. (iii) Treating an aqueous solution of sodium chlorite by electrolysis. (2) The generator effluent contains at least 90 percent (by weight) of chlorine dioxide with respect to all...

2014-04-01

352

21 CFR 173.300 - Chlorine dioxide.  

Code of Federal Regulations, 2012 CFR

...chlorate with hydrogen peroxide in the presence of sulfuric acid. (iii) Treating an aqueous solution of sodium chlorite by electrolysis. (2) The generator effluent contains at least 90 percent (by weight) of chlorine dioxide with respect to all...

2012-04-01

353

The ERK1/2 Signaling Pathway Is Involved in Sulfur Dioxide Preconditioning-Induced Protection against Cardiac Dysfunction in Isolated Perfused Rat Heart Subjected to Myocardial Ischemia/Reperfusion  

PubMed Central

Ischemia/reperfusion injury (IRI) occurs frequently during reperfusion of ischemic myocardium, and preconditioning has been regarded as one of the best strategies to prevent myocardial injury during the ischemia/reperfusion process. Our previous studies indicated that a small dose of sulfur dioxide (SO2) used as preconditioning exerts cardioprotection. However, the mechanisms underlying the cardioprotection remain unclear. The present study was designed to examine if the extracellular regulated protein kinases 1/2 (ERK1/2) signaling pathway mediated protection against cardiac dysfunction after SO2 preconditioning in isolated rat hearts subjected to ischemia/reperfusion (I/R). Langendorff heart perfusion was performed in vitro, where 56 male Wistar rats were randomly divided into seven groups: control group, 5 ?mol/L SO2 group (S5), 2-(2-Amino-3-methoxyphenyl)-4H-1-benzopyran-4-one (PD98059) + 5 ?mol/L SO2 (PD98059 + S5) group, PD98059 group, I/R group, 5 ?mol/L SO2 + I/R (S5 + I/R) group and PD98059 + 5 ?mol/L SO2 + I/R (PD98059 + S5 + I/R) group. Cardiac function and myocardial phosphorylated ERK1/2 protein were measured. We found that I/R in isolated rat heart resulted in cardiac dysfunction with a significant increase in phosphorylated ERK1/2 protein. SO2 preconditioning markedly suppressed phosphorylated ERK1/2 protein and improved cardiac function in isolated rat heart with I/R (p < 0.05). However, pre-treatment with PD98059 could prevent the above effects of SO2 preconditioning. In conclusion, SO2 preconditioning protected against cardiac dysfunction in isolated rat heart subjected to I/R via suppression of the over-activation of the ERK1/2 signaling pathway. PMID:24217229

Huang, Pan; Sun, Yan; Yang, Jinyan; Chen, Siyao; Liu, Angie Dong; Holmberg, Lukas; Huang, Xiaomei; Tang, Chaoshu; Du, Junbao; Jin, Hongfang

2013-01-01

354

The 1981-1982 NCLAN (National Crop Loss Assessment Network) program at LLNL: The effects of ozone and sulfur dioxide, singly and in combination, on field-grown tomato  

SciTech Connect

The combined effects of ozone (O/sub 3/) and sulfur dioxide (SO/sub 2/) exposures on tomato (Lycopersicon esculentum Mill.) crop yields were measured during the 1981 and 1982 growing seasons. The effort, part of the National Crop Loss Assessment Network (NCLAN), had the objective of determining the yield dose response of tomato grown under commercial conditions. Dose response was determined using step-wise multiple regression techniques and was expressed as reduction in marketable yield as a function of increased pollutant levels. The crops were harvested during mid-September 1981 and during mid-October 1982. No O/sub 3/- or So/sub 2/-induced visible injury symptons (lesions, chlorosis, or becrosis) were apparent on foliage or fruits. Total marketable fruit fresh weight was used as the dependent variable in the regression analysis because it most closely represented the economic value of the crop. Comparison of chambered- and companion-plot data showed that the chambers themselves caused significant effects on the crop. Yields were reduced 12% in 1981 and 24% in 1982 due to the chambers. There was also more unripened fruit within the chambers because of chamber-induced uneven distribution of an aerially-applied ripening agent. Dose-response results were independent of the chamber effects. Based on companion-plot data, the yield of the crop in the research area was 65/plus minus/2 Mg ha/sup /minus/1/ in both years. The research-area yields correlated well with those from the adjacent commercial plantation. With respect to tomato production in the San Joaquin Valley, we recommend that an air quality management strategy be adopted to contain ambient O/sub 3/ concentrations at or below present levels. Containment at present levels would avoid O/sub 3/-induced tomato yield reductions greater than 7%, even during atypical years such as 1982. 26 refs., 17 figs., 9 tabs.

Surano, K.A.; Mutters, R.G.; Temple, P.J.; Bingham, G.E.; Kercher, J.R.; Shinn, J.H.

1987-07-01

355

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

356

Emissions of sulfur gases from wetlands  

NASA Technical Reports Server (NTRS)

Data on the emissions of sulfur gases from marine and freshwater wetlands are summarized with respect to wetland vegetation type and possible formation mechanisms. The current data base is largest for salt marshes inhabited by Spartina alterniflora. Both dimethyl sulfide (DMS) and hydrogen sulfide (H2S) dominate emissions from salt marshes, with lesser quantities of methyl mercaptan (MeSH), carbonyl sulfide (COS), carbon disulfide (CS2) and dimethyl disulfide (DMDS) being emitted. High emission rates of DMS are associated with vegetation that produces the DMS precursor dimethylsulfonionpropionate (DMSP). Although large quantities of H2S are produced in marshes, only a small percentage escapes to the atmosphere. High latitude marshes emit less sulfur gases than temperate ones, but DMS still dominates. Mangrove-inhabited wetlands also emit less sulfur than temperate S. alterniflora marshes. Few data are available on sulfur gas emissions from freshwater wetlands. In most instances, sulfur emissions from temperate freshwater sites are low. However, some temperate and subtropical freshwater sites are similar in magnitude to those from marine wetlands which do not contain vegetation that produces DMSP. Emissions are low in Alaskan tundra but may be considerably higher in some bogs and fens.

Hines, Mark E.

1992-01-01

357

DETERMINATION OF GAS-PHASE DIMETHYL SULFATE AND MONOMETHYL HYDROGEN SULFATE  

EPA Science Inventory

Analytical techniques have been developed for the collection and determination of gas phase dimethyl sulfate and monomethyl sulfuric acid in the flue lines and plumes of power plants and in the ambient atmosphere. The techniques involve the collection of the gas phase species in ...

358

Formation of particulate sulfur species (sulfate and methanesulfonate) during summer over the Eastern Mediterranean: A modelling approach  

NASA Astrophysics Data System (ADS)

To improve our understanding of the mechanisms of particulate sulfur formation (non sea-salt sulfate, nss-SO 42-) and methanesulfonate (MS x used here to represent the sum of gaseous methanesulfonic acid, MSA, and particulate methanesulfonate, MS -) in the eastern Mediterranean and to evaluate the relative contribution of biogenic and anthropogenic sources to the S budget, a chemical box model coupled offline with an aerosol-cloud model has been used. Based on the measurements of gaseous dimethyl sulfide (DMS) and methanesulfonic acid (MSA) and the MSA sticking coefficient determined during the Mediterranean Intensive Oxidant Study (MINOS) experiment, the yield of gaseous MSA from the OH-initiated oxidation of DMS was calculated to be about 0.3%. Consequently, MSA production from gas-phase oxidation of DMS is too small to explain the observed levels of MS -. On the other hand, heterogeneous reactions of dimethyl sulfoxide (DMSO) and its gas-phase oxidation product methanesulfinic acid (MSIA) can account for most of the observed MS - levels. The modelling results indicate that about 80% of the production of MS - can be attributed to heterogeneous reactions. Observed submicron nss-SO 42- levels can be fully explained by homogeneous (photochemical) gas-phase oxidation of sulfur dioxide (SO 2) to sulfuric acid (H 2SO 4), which is subsequently scavenged by (mainly submicron) aerosol particles. The predominant oxidant during daytime is hydroxyl radical (OH) showing very high peak levels in the area during summer mostly under cloudless conditions. Therefore, during summer in the east Mediterranean, heterogeneous sulfate production appears to be negligible. This result is of particular interest for sulfur abatement strategy. On the other hand only about 10% of the supermicron nss-SO 42- can be explained by condensation of gas-phase H 2SO 4, the rest must be formed via heterogeneous pathways. Marine biogenic sulfur emissions contribute up to 20% to the total oxidized sulfur production (SO 2 and H 2SO 4) in good agreement with earlier estimates for the area.

Mihalopoulos, N.; Kerminen, V. M.; Kanakidou, M.; Berresheim, H.; Sciare, J.

359

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 ...

360

The surface chemistry of dimethyl disulfide on copper.  

PubMed

The surface chemistry of dimethyl disulfide (DMDS) is studied on a Cu(111) single crystal and a polished copper foil in ultrahigh vacuum as a basis for understanding its tribological chemistry using a combination of temperature-programmed desorption (TPD), reflection-absorption infrared spectroscopy (RAIRS), and X-ray photoelectron spectroscopy (XPS). Low-energy electron diffraction reveals that the polished foil becomes ordered on heating in vacuo and displays identical surface chemistry to that found on the Cu(111) surface. Dimethyl disulfide reacts with the copper surface at 80 K to form thiolate species. Heating the surface to ?230 K causes a small portion of the thiolate species to decompose to form methyl groups adsorbed on the surface. Further heating results in methane and C(2) hydrocarbon desorption at ?426 K, due to a reaction of adsorbed methyl species, to completely remove carbon from the surface and to deposit atomic sulfur. PMID:20617851

Furlong, Octavio J; Miller, Brendan P; Li, Zhenjun; Walker, Joshua; Burkholder, Luke; Tysoe, Wilfred T

2010-11-01

361

Thermodynamics of Hydrogen Production from Dimethyl Ether Steam Reforming and Hydrolysis  

SciTech Connect

The thermodynamic analyses of producing a hydrogen-rich fuel-cell feed from the process of dimethyl ether (DME) steam reforming were investigated as a function of steam-to-carbon ratio (0-4), temperature (100 C-600 C), pressure (1-5 atm), and product species: acetylene, ethanol, methanol, ethylene, methyl-ethyl ether, formaldehyde, formic acid, acetone, n-propanol, ethane and isopropyl alcohol. Results of the thermodynamic processing of dimethyl ether with steam indicate the complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide for temperatures greater than 200 C and steam-to-carbon ratios greater than 1.25 at atmospheric pressure (P = 1 atm). Increasing the operating pressure was observed to shift the equilibrium toward the reactants; increasing the pressure from 1 atm to 5 atm decreased the conversion of dimethyl ether from 99.5% to 76.2%. The order of thermodynamically stable products in decreasing mole fraction was methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol, methyl-ethyl ether and methanol--formaldehyde, formic acid, and acetylene were not observed. The optimal processing conditions for dimethyl ether steam reforming occurred at a steam-to-carbon ratio of 1.5, a pressure of 1 atm, and a temperature of 200 C. Modeling the thermodynamics of dimethyl ether hydrolysis (with methanol as the only product considered), the equilibrium conversion of dimethyl ether is limited. The equilibrium conversion was observed to increase with temperature and steam-to-carbon ratio, resulting in a maximum dimethyl ether conversion of approximately 68% at a steam-to-carbon ratio of 4.5 and a processing temperature of 600 C. Thermodynamically, dimethyl ether processed with steam can produce hydrogen-rich fuel-cell feeds--with hydrogen concentrations exceeding 70%. This substantiates dimethyl ether as a viable source of hydrogen for PEM fuel cells.

T.A. Semelsberger

2004-10-01

362

Catalyst for elemental sulfur recovery process  

DOEpatents

A catalytic reduction process is described for the direct recovery of elemental sulfur from various SO[sub 2]-containing industrial gas streams. The catalytic process provides high activity and selectivity, as well as stability in the reaction atmosphere, for the reduction of SO[sub 2] to elemental sulfur product with carbon monoxide or other reducing gases. The reaction of sulfur dioxide and reducing gas takes place over a metal oxide composite catalyst having one of the following empirical formulas: [(FO[sub 2])[sub 1[minus]n](RO)[sub n

Flytzani-Stephanopoulos, M.; Liu, W.

1995-01-24

363

A proposed volcanic sulfur dioxide index (VSI)  

NASA Astrophysics Data System (ADS)

This paper proposes a volcanic SO2 index (VSI), on the basis of a 15-year satellite sampling of volcanic eruptions. This index is scaled to be compatible with the commonly cited volcanic explosivity index (VEI) used to compare explosive volcanic eruptions. A range of SO2 for each VEI level is proposed so that estimates of SO2 emission can be made from the historic VEI database. Volcanic SO2 from large eruptions can be routinely measured by satellite instruments, and for the smaller eruptions, where the sensitivity of satellite remote sensing is not sufficient, ground-based measurements are becoming more available. At the present time we do not think SO2 can be used to define an accurate climate-perturbation index, as we have both insufficient data on volcanic SO2 and understanding of the volcano-climate relationship.

Schnetzler, C. C.; Bluth, G. J. S.; Krueger, A. J.; Walter, L. S.

1997-01-01

364

Brassica response to sulfur dioxide and ozone  

SciTech Connect

Plants may be exposed to SO{sub 2} and O{sub 3} in the ambient environment, in either concurrent or sequential patterns. The objective of this research was to identify dose response relationships for plant responses to two exposure types, and to test the similarity of these relationships. Young cabbage and rutabaga plants were exposed to SO{sub 2} and O{sub 3} either concurrently or sequentially, and growth responses were determined. When exposed to the gases concurrently, cabbage was sensitive to O{sub 3} only, whereas rutabaga was sensitive to both gases. Following sequential exposure, both species were sensitive to both gases. A comparison of the ranks of the data matrices indicated that while the growth responses within species and exposure type were often a rescaling of the same equation, they were different among species and exposure types. The experiments demonstrated that dose response relationships can be a precise tool for the differentiation of plant responses to various types of multiple pollutant exposure.

Marie, B.; Ryan, D.; Ormrod, D. (Univ. of Guelph, Ontario (Canada))

1989-04-01

365

SULFUR DIOXIDE OXIDATION IN SCRUBBER SYSTEMS  

EPA Science Inventory

The report relates the liquid-phase oxidation kinetics of bisulfite and sulfite anions (determined in bench scale experiments) to conditions representative of limestone scrubbers used for flue gas desulfurization. The chemical reaction rates were determined for clear solutions an...

366

Evaluation of sulfur dioxide emission allowance trading  

SciTech Connect

This paper is a preliminary draft of the paper to be given at the A&WMA Acid Rain Conference on January 20-22, 1997. This version was prepared for a conference on {open_quotes}Market Tools for Green Goals{close_quotes} at the Chicago Board of Trade, November 1, 1996. The conference was sponsored by the Workshop on Market-Based Approaches to Environmental Policy at the University of Illinois at Chicago, and the Chicago Board of Trade. We are grateful to Richard Kosobud for comments on an earlier draft.

Bohi, D.R.; Burtraw, D. [Resources for the Future, Washington, DC (United States)

1997-12-31

367

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. PMID:22984393

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

2012-01-01

368

Integrated boiler, superheater, and decomposer for sulfuric acid decomposition  

DOEpatents

A method and apparatus, constructed of ceramics and other corrosion resistant materials, for decomposing sulfuric acid into sulfur dioxide, oxygen and water using an integrated boiler, superheater, and decomposer unit comprising a bayonet-type, dual-tube, counter-flow heat exchanger with a catalytic insert and a central baffle to increase recuperation efficiency.

Moore, Robert (Edgewood, NM); Pickard, Paul S. (Albuquerque, NM); Parma, Jr., Edward J. (Albuquerque, NM); Vernon, Milton E. (Albuquerque, NM); Gelbard, Fred (Albuquerque, NM); Lenard, Roger X. (Edgewood, NM)

2010-01-12

369

Sulfuric Acid Mist Generation in Utility Boiler Flue Gas  

Microsoft Academic Search

Sulfur Dioxide (SO2), Sulfur Trioxide (SO3) and Oxides of Nitrogen, mainly NO and NO2, are generated during the combustion of certain fossil fuels. Electric power generating units contribute more than 70% of the national SOx emissions (1). When significant volumes of flue gas containing these oxides are discharged to the atmosphere, various state or local authorities set standards for the

Boris Altshuler

370

Bisphosphine dioxides  

DOEpatents

A process for the production of organic bisphosphine dioxides from organic bisphosphonates. The organic bisphosphonate is reacted with a Grignard reagent to give relatively high yields of the organic bisphosphine dioxide.

Moloy, Kenneth G. (Charleston, WV)

1990-01-01

371

Bisphosphine dioxides  

DOEpatents

A process is described for the production of organic bisphosphine dioxides from organic bisphosphonates. The organic bisphosphonate is reacted with a Grignard reagent to give relatively high yields of the organic bisphosphine dioxide.

Moloy, K.G.

1990-02-20

372

Environmental management of sulfur trioxide emission: impact of SO3 on human health.  

PubMed

The major contributors to global acidification are sulfur oxides and nitrogen oxides emitted mostly by the burning of fossil fuels. From the scientific point of view, it is necessary to make a clear distinction between sulfur dioxide and sulfur trioxide when referring to sulfur oxides. These two air pollutants have different properties. This paper reports the following aspects: the strong effect of sulfur trioxide on local human health (a case study of asthma in Yokkaichi), the problem of corrosion caused by sulfur trioxide, the difference in analytical methods for determining sulfur dioxide concentrations and sulfur trioxide concentrations, and the difference in removal methods for sulfur dioxide and sulfur trioxide. An important initiative at the third European conference of environment ministers was that the issue of human health related to local air pollution should be given priority over that of global pollution. The declines in the emissions of sulfur dioxide and nitrogen oxides have mainly been effective in reducing acidification due to long-range transport. The reduction in sulfur trioxide may be more effective in improving local human health mentioned in the initiative. PMID:11393318

Kikuchi, R

2001-06-01

373

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...

374

The shadow price of substitutable sulfur in the US electric power plant: a distance function approach.  

PubMed

Given restrictions on sulfur dioxide emissions, a feasible long-run response could involve either an investment in improving boiler fuel-efficiency or a shift to a production process that is effective in removing sulfur dioxide. To allow for the possibility of substitution between sulfur and productive capital, we measure the shadow price of sulfur dioxide as the opportunity cost of lowering sulfur emissions in terms of forgone capital. The input distance function is estimated with data from 51 coal-fired US power units operating between 1977 and 1986. The indirect Morishima elasticities of substitution indicate that the substitutability of capital for sulfur is relatively high. The overall weighted average estimate of the shadow price of sulfur is -0.076 dollars per pound in constant 1976 dollars. PMID:15993533

Lee, Myunghun

2005-10-01

375

Oxidation of Dimethyl Sulfide to Dimethyl Sulfoxide by Phototrophic Purple Bacteria  

PubMed Central

Enrichment cultures of phototrophic purple bacteria rapidly oxidized up to 10 mM dimethyl sulfide (DMS) to dimethyl sulfoxide (DMSO). DMSO was qualitatively identified by proton nuclear magnetic resonance. By using a biological assay, DMSO was always quantitatively recovered from the culture media. DMS oxidation was not detected in cultures incubated in the dark, and it was slow in cultures exposed to full daylight. Under optimal conditions, the second-order rate constant for DMS oxidation was 6 day?1 mg of protein?1 ml?1. The rate constant was reduced in the presence of high concentration of sulfide (>1 mM), but was not affected by the addition of acetate. DMS was also oxidized to DMSO by a pure strain (tentatively identified as a Thiocystis sp.) isolated from the enrichment cultures. DMS supported growth of the enrichment cultures and of the pure strain by serving as an electron source for photosynthesis. A determination of the amount of protein produced in the cultures and an estimation of the electron balance suggested that the two electrons liberated during the oxidation of DMS to DMSO were quantitatively used to reduce carbon dioxide to biomass. The oxidation of DMS by phototrophic purple bacteria may be an important source of DMSO detected in anaerobic ponds and marshes. PMID:16347425

Zeyer, Josef; Eicher, Petra; Wakeham, Stuart G.; Schwarzenbach, René P.

1987-01-01

376

Safety considerations for the use of sulfur in sulfur-modified pavement materials  

E-print Network

of HZS Toxicity of Sulfur Dioxide Hydrogen Sulfide Emissions from Plasticization of Sulfur Mith Several Additives 30 36 37 39 47 LIST OF FIGURES Figure Effect of Temperature on the Hydrogen Sulfide Concentration Page Comparison of H2S... working distance for laboratory personnel. All mixes were prepared at temperatures below 300'F. The effect of temperature on the hydrogen sulfide concentration generated from the mix is shown in Figure 1 (6). The true peak con- centrations which occur...

Jacobs, Carolyn Yuriko

1980-01-01

377

Performance and cost models for the direct sulfur recovery process. Task 1 Topical report, Volume 3  

SciTech Connect

The purpose of this project is to develop performance and cost models of the Direct Sulfur Recovery Process (DSRP). The DSRP is an emerging technology for sulfur recovery from advanced power generation technologies such as Integrated Gasification Combined Cycle (IGCC) systems. In IGCC systems, sulfur present in the coal is captured by gas cleanup technologies to avoid creating emissions of sulfur dioxide to the atmosphere. The sulfur that is separated from the coal gas stream must be collected. Leading options for dealing with the sulfur include byproduct recovery as either sulfur or sulfuric acid. Sulfur is a preferred byproduct, because it is easier to handle and therefore does not depend as strongly upon the location of potential customers as is the case for sulfuric acid. This report describes the need for new sulfur recovery technologies.

Frey, H.C. [North Carolina State Univ., Raleigh, NC (United States); Williams, R.B. [Carneigie Mellon Univ., Pittsburgh, PA (United States)

1995-09-01

378

Field-deployable instrumentation for fast measurement of various atmospheric sulfur compounds in the parts per trillion range  

NASA Astrophysics Data System (ADS)

A field deployable instrumentation was developed for determining atmospheric dimethyl sulfide (DMS), dimethyl sulfoxide (DMSO), dimethyl sulfone (DMSO 2) and sulfur dioxide (SO2) using atmospheric pressure ionization mass spectrometry (APIMS) Isotopically labeled analytes were used as internal standards. Detection limits below 1 part per trillion by volume (pptv) (S/N is >5 at 0.5 pptv background level) at one sample per second was achieved. Extensive laboratory studies were conducted to evaluate the instrument's sensitivity and stability as well as to simulate the real time measurements. This dissertation reports data from a first time deployment of the instrumentation at the South Pole in December 1998 and January 1999. Data from this deployment showed that this instrumentation had adequate performance in detecting all four species. In addition, methane sulfinic acid (MESA) was also observed in the atmosphere for first real time. The lowest concentrations of all four species occurred when the temperature inversion was strongest and greatest when the inversion was weakest or absent. This observation implies that the origin of these species is the free troposphere just above the inversion and not from local pollution. The most found concentrations for DMS, DMSO, DMSO2, MESA and SO 2 were 0.7, 0.9, 1.2, 0.1 and 9 pptv. These field tests further suggest that our APIMS instrumentation be adequate for determining the fluxes of DMS and SO2 by eddy correlation technique. Finally, in the South Pole data there was strong evidence that H2O2 and HNO 3 were observed as complexes with CO3-. This implies that these species could be determined by APIMS if isotopically labeled standards of the species are used and a means of determining the blank is established.

Xu, Nucleus He

379

RECENT ADVANCES IN THE DEVELOPMENT OF THE HYBRID SULFUR PROCESS FOR HYDROGEN PRODUCTION  

SciTech Connect

Thermochemical processes are being developed to provide global-scale quantities of hydrogen. A variant on sulfur-based thermochemical cycles is the Hybrid Sulfur (HyS) Process, which uses a sulfur dioxide depolarized electrolyzer (SDE) to produce the hydrogen. In the HyS Process, sulfur dioxide is oxidized in the presence of water at the electrolyzer anode to produce sulfuric acid and protons. The protons are transported through a cation-exchange membrane electrolyte to the cathode and are reduced to form hydrogen. In the second stage of the process, the sulfuric acid by-product from the electrolyzer is thermally decomposed at high temperature to produce sulfur dioxide and oxygen. The two gases are separated and the sulfur dioxide recycled to the electrolyzer for oxidation. The Savannah River National Laboratory (SRNL) has been exploring a fuel-cell design concept for the SDE using an anolyte feed comprised of concentrated sulfuric acid saturated with sulfur dioxide. The advantages of this design concept include high electrochemical efficiency and small footprint compared to a parallel-plate electrolyzer design. This paper will provide a summary of recent advances in the development of the SDE for the HyS process.

Hobbs, D.

2010-07-22

380

Measurement of biogenic sulfur gases emission from some Chinese and Japanese soils  

NASA Astrophysics Data System (ADS)

Emission of volatile sulfur gases from waterlogged paddy soils and upland soils of China and Japan was studied in the laboratory. Emission of hydrogen sulfide (H 2S), carbonyl sulfide (COS), methyl mercaptan (CH 3SH), dimethyl sulfide (DMS), carbon disulfide (CS 2) and dimethyl disulfide (DMDS) were detected. Emission of sulfur gases from paddy soil was more than that from upland, and emission from the Chinese paddy soils was more than that from Japanese. At the same soil, emission of sulfur gases, when both organic manure and chemical fertilizer were applied was higher than when only organic manure or only chemical fertilizer was applied. Under anaerobic conditions, detected biogenic sulfur gases were far more than that under aerobic conditions, H 2S was the most obvious. The results have also shown that, at higher temperature, emission and expiration rate of volatile sulfur gases were higher than that at lower temperature.

Yang, Z.; Kanda, K.; Tsuruta, H.; Minami, K.

381

Metabolic Fingerprint of Dimethyl Sulfone (DMSO2) in Microbial-Mammalian Co-metabolism.  

PubMed

There is growing awareness that intestinal microbiota alters the energy harvesting capacity of the host and regulates metabolism. It has been postulated that intestinal microbiota are able to degrade unabsorbed dietary components and transform xenobiotic compounds. The resulting microbial metabolites derived from the gastrointestinal tract can potentially enter the circulation system, which, in turn, affects host metabolism. Yet, the metabolic capacity of intestinal microbiota and its interaction with mammalian metabolism remains largely unexplored. Here, we review a metabolic pathway that integrates the microbial catabolism of methionine with mammalian metabolism of methanethiol (MT), dimethyl sulfide (DMS), and dimethyl sulfoxide (DMSO), which together provide evidence that supports the microbial origin of dimethyl sulfone (DMSO2) in the human metabolome. Understanding the pathway of DMSO2 co-metabolism expends our knowledge of microbial-derived metabolites and motivates future metabolomics-based studies on ascertaining the metabolic consequences of intestinal microbiota on human health, including detoxification processes and sulfur xenobiotic metabolism. PMID:25245235

He, Xuan; Slupsky, Carolyn M

2014-12-01

382

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

383

Consistent increase in dimethyl sulfide (DMS) in response to high CO2 in five shipboard bioassays from contrasting NW European waters  

NASA Astrophysics Data System (ADS)

The ubiquitous marine trace gas dimethyl sulfide (DMS) comprises the greatest natural source of sulfur to the atmosphere and is a key player in atmospheric chemistry and climate. We explore the short-term response of DMS production and cycling and that of its algal precursor dimethyl sulfoniopropionate (DMSP) to elevated carbon dioxide (CO2) and ocean acidification (OA) in five 96 h shipboard bioassay experiments. Experiments were performed in June and July 2011, using water collected from contrasting sites in NW European waters (Outer Hebrides, Irish Sea, Bay of Biscay, North Sea). Concentrations of DMS and DMSP, alongside rates of DMSP synthesis and DMS production and consumption, were determined during all experiments for ambient CO2 and three high-CO2 treatments (550, 750, 1000 ?atm). In general, the response to OA throughout this region showed little variation, despite encompassing a range of biological and biogeochemical conditions. We observed consistent and marked increases in DMS concentrations relative to ambient controls (110% (28-223%) at 550 ?atm, 153% (56-295%) at 750 ?atm and 225% (79-413%) at 1000 ?atm), and decreases in DMSP concentrations (28% (18-40%) at 550 ?atm, 44% (18-64%) at 750 ?atm and 52% (24-72%) at 1000 ?atm). Significant decreases in DMSP synthesis rate constants (?DMSP, d-1) and DMSP production rates (nmol d-1) were observed in two experiments (7-90% decrease), whilst the response under high CO2 from the remaining experiments was generally indistinguishable from ambient controls. Rates of bacterial DMS gross consumption and production gave weak and inconsistent responses to high CO2. The variables and rates we report increase our understanding of the processes behind the response to OA. This could provide the opportunity to improve upon mesocosm-derived empirical modelling relationships and to move towards a mechanistic approach for predicting future DMS concentrations.

Hopkins, F. E.; Archer, S. D.

2014-09-01

384

Consistency Between Measurements and Theory for Sulfur Gases and Oxidants During the Pacific Atmospheric Sulfur Experiment  

NASA Astrophysics Data System (ADS)

Airborne gas phase measurements of sulfur dioxide, dimethylsulfide, dimethylsulfoxide, methane sulfonic acid, sulfuric acid, hydroxyl, perhydroxyl, hydrogen peroxide, methylhydroperoxide, ozone, and carbon monoxide together with aerosol microphysical properties and bulk and size-dependent aerosol composition are examined for consistency with photochemical theory. The observations come from 14 research flights using the NCAR C-130 flown mostly southeast of Kiritimati in relatively cloud-free marine boundary layer air. This region was chosen because of its extremely low nitrogen oxide mixing ratios and minimal horizontal gradients in composition. A size-dependent gas-particle mass-transfer model is used to calculate the exchange rates of dimethylsulfoxide, methanesulfonic acid and sulfuric acid between the gas and aerosol. Gas kinetic reactions, aqueous reactions, and heterogeneous processes are used in the evaluation. Mass accommodation coefficients, Henry's Law solubilities, and the effective yields of methanesulfonic acid, sulfur dioxide, sulfuric acid and dimethylsulfoxide from dimethylsulfide are estimated and consistent with the literature. Gas phase hydroxyl chemistry alone is sufficient to explain observed methanesulfonic acid and sulfuric acid vapor concentrations.

Heikes, B. G.; Higbie, A.; O'Sullivan, D. W.; Bandy, A. R.; Mauldin, L.; Cantrell, C.; Anderson, R. S.; Campos, T.; Huebert, B.; Bloomquist, B.; Wang, Y.; Heizer, C. G.; Pollack, I. B.; Weinheimer, A. J.

2008-12-01

385

Oxygen and sulfur interactions with a clean iron surface and the effect of rubbing contact on these interactions  

NASA Technical Reports Server (NTRS)

The interaction of sulfur and oxygen with an iron surface was studied with Auger spectroscopy analysis both statically and during sliding-friction experiments in a vacuum environment. Oxygen, hydrogen sulfide, methyl mercaptan, and sulfur dioxide were adsorbed to an iron surface. Results indicate that sulfide films formed on clean iron surfaces are completely displaced by oxygen. Hydrocarbons containing sulfur, such as methyl mercaptan, adsorb dissociatively. Less sulfur is adsorbed during sliding with hydrogen sulfide and methyl mercaptan than in the absence of sliding. With both oxygen and sulfur dioxide, sliding did not affect the amount of material adsorbed to iron.

Buckley, D. H.

1973-01-01

386

Anomalous fractionations of sulfur isotopes during thermochemical sulfate reduction.  

PubMed

Anomalously fractionated sulfur isotopes in many sedimentary rocks older than 2.4 billion years have been widely believed to be the products of ultraviolet photolysis of volcanic sulfur dioxide in an anoxic atmosphere. Our laboratory experiments have revealed that reduced-sulfur species produced by reactions between powders of amino acids and sulfate at 150 degrees to 200 degrees C possess anomalously fractionated sulfur isotopes: Delta33S = +0.1 to +2.1 per mil and Delta36S = -1.1 to +1.1 per mil. These results suggest that reactions between organic matter in sediments and sulfate-rich hydrothermal solutions may have produced anomalous sulfur isotope signatures in some sedimentary rocks. If so, the sulfur isotope record of sedimentary rocks may be linked to the biological and thermal evolution of Earth in ways different than previously thought. PMID:19372427

Watanabe, Yumiko; Farquhar, James; Ohmoto, Hiroshi

2009-04-17

387

An early application of the Sulfur Cycle Hydrogen Production Process  

NASA Astrophysics Data System (ADS)

The electrochemical step of the Sulfur Cycle Hydrogen Production Process can be commercialized irrespective of the success or failure of activities in development of the high temperature thermochemical or heat source technologies. This version of the Sulfur Cycle, called the 'open-cycle', uses sulfur dioxide and water to produce two marketable products, i.e., hydrogen and sulfuric acid. An attractive application of the open-cycle has been identified in improving the gas cleanup systems for coal fired power plants. Analyses indicate that the revenues that could be realized by the power plant operator from the sale of hydrogen and sulfuric acid exceed the costs of owning and operating the Sulfur Cycle 'add-on' to the power plant.

Parker, G. H.; Farbman, G. H.; Summers, W. A.

388

Methane, carbon dioxide, and hydrogen sulfide production from the terminal methiol group of methionine by anaerobic lake sediments.  

PubMed

A significant portion of the sulfide in lake sediments may be derived from sulfur-containing amino acids. Methionine degradation in Lake Mendota (Wisconsin) sediments was studied with gas chromatographic and radiotracer techniques. Temperature optimum and inhibitor studies showed that this process was biological. Methane thiol and dimethyl sulfide were produced in sediments when 1-mumol/ml unlabeled methionine was added. When chloroform (an inhibitor of one-carbon metabolism) was added to the sediments, methane thiol, carbon disulfide, and n-propane thiol were produced, even when no methionine was added. When S-labeled methionine was added to the sediments in tracer quantities (1.75 nmol/ml), labeled hydrogen sulfide was produced, and a roughly equal amount of label was incorporated into insoluble material. Methane and carbon dioxide were produced from [methyl-C]methionine. Evidence is given favoring methane thiol as an intermediate in the formation of methane, carbon dioxide, and hydrogen sulfide from the terminal methiol group of methionine. Methionine may be an important source of sulfide in lake sediments. PMID:16345275

Zinder, S H; Brock, T D

1978-02-01

389

Methane, Carbon Dioxide, and Hydrogen Sulfide Production from the Terminal Methiol Group of Methionine by Anaerobic Lake Sediments  

PubMed Central

A significant portion of the sulfide in lake sediments may be derived from sulfur-containing amino acids. Methionine degradation in Lake Mendota (Wisconsin) sediments was studied with gas chromatographic and radiotracer techniques. Temperature optimum and inhibitor studies showed that this process was biological. Methane thiol and dimethyl sulfide were produced in sediments when 1-?mol/ml unlabeled methionine was added. When chloroform (an inhibitor of one-carbon metabolism) was added to the sediments, methane thiol, carbon disulfide, and n-propane thiol were produced, even when no methionine was added. When 35S-labeled methionine was added to the sediments in tracer quantities (1.75 nmol/ml), labeled hydrogen sulfide was produced, and a roughly equal amount of label was incorporated into insoluble material. Methane and carbon dioxide were produced from [methyl-14C]methionine. Evidence is given favoring methane thiol as an intermediate in the formation of methane, carbon dioxide, and hydrogen sulfide from the terminal methiol group of methionine. Methionine may be an important source of sulfide in lake sediments. PMID:16345275

Zinder, S. H.; Brock, T. D.

1978-01-01

390

COMPONENT DEVELOPMENT NEEDS FOR THE HYBRID SULFUR ELECTROLYZER  

SciTech Connect

Fiscal year 2008 studies in electrolyzer component development have focused on the characterization of membrane electrode assemblies (MEA) after performance tests in the single cell electrolyzer, evaluation of electrocatalysts and membranes using a small scale electrolyzer and evaluating the contribution of individual cell components to the overall electrochemical performance. Scanning electron microscopic (SEM) studies of samples taken from MEAs testing in the SRNL single cell electrolyzer test station indicates a sulfur-rich layer forms between the cathode catalyst layer and the membrane. Based on a review of operating conditions for each of the MEAs evaluated, we conclude that the formation of the layer results from the reduction of sulfur dioxide as it passes through the MEA and reaches the catalyst layer at the cathode-membrane interface. Formation of the sulfur rich layer results in partial delamination of the cathode catalyst layer leading to diminished performance. Furthermore we believe that operating the electrolyzer at elevated pressure significantly increases the rate of formation due to increased adsorption of hydrogen on the internal catalyst surface. Thus, identification of a membrane that exhibits much lower transport of sulfur dioxide is needed to reduce the quantity of sulfur dioxide that reaches the cathode catalyst and is reduced to produce the sulfur-rich layer. Three candidate membranes are currently being evaluated that have shown promise from preliminary studies, (1) modified Nafion{reg_sign}, (2) polybenzimidazole (PBI), and (3) sulfonated Diels Alder polyphenylene (SDAPP). Testing examined the activity for the sulfur dioxide oxidation of platinum (Pt) and platinum-alloy catalysts in 30 wt% sulfuric acid solution. Linear sweep voltammetry showed an increase in activity when catalysts in which Pt is alloyed with non-noble transition metals such as cobalt and chromium. However when Pt is alloyed with noble metals, such as iridium or ruthenium, the kinetic activity decreases. We recommend further testing to determine if these binary alloys will provide the increased reaction kinetic needed to meet the targets. We also plan to test the performance of these catalyst materials for both proton and sulfur dioxide reduction. The latter may provide another parameter by which we can control the reduction of sulfur dioxide upon transport to the cathode catalyst surface. A small scale electrolyzer (2 cm{sup 2}) has been fabricated and successfully installed as an additional tool to evaluate the effect of different operating conditions on electrolyzer and MEA performance. Currently this electrolyzer is limited to testing at temperatures up to 80 C and at atmospheric pressure. Selected electrochemical performance data from the single cell sulfur dioxide depolarized electrolyzer were analyzed with the aid of an empirical equation which takes into account the overpotential of each of the components. By using the empirical equation, the performance data was broken down into its components and a comparison of the potential losses was made. The results indicated that for the testing conditions of 80 C and 30 wt% sulfuric acid, the major overpotential contribution ({approx}70 % of all losses) arise from the slow reaction rate of oxidation of sulfur dioxide. The results indicate that in order to meet the target of hydrogen production at 0.5 A/cm{sup 2} at 0.6 V and 50 wt% sulfuric acid, identification of a better catalyst for sulfur dioxide oxidation will provide the largest gain in electrolyzer performance.

Hobbs, D; Hector Colon-Mercado, H; Mark Elvington, M

2008-05-30

391

Biotransformation of sulfur and nitrogen oxides in stack gases  

SciTech Connect

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

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

1995-10-01

392

Preparation and electrical properties of lithium–sulfur-composite polymer batteries  

Microsoft Academic Search

The lithium\\/sulfur batteries consisted of a composite cathode, a polymer electrolyte, and lithium anode. The composite cathode was made from active sulfur (or lithium sulfide), carbon black, poly(ethylene oxide) (PEO), LiClO4, and acetonitrile. And the polymer electrolyte (PE) was made of gel-type linear PEO with tetra(ethylene glycol dimethyl ether). The open circuit voltage (OCV) of the Li–S battery was about

Byoung Ho Jeon; Jin Hee Yeon; In Jae Chung

2003-01-01

393

Selective Detection of Sulfur Derivatives Using Microfabricated Tuning Fork-Based Sensors  

PubMed Central

The paper describes an integtrated sensor system that can selectively and reversibly detect sulfur derivatives in the presence of interferent molecules. This is accomplished by integrating analyte-specific sensing materials with optimized filter materials. Microfabricated quartz tuning fork arrays are used to provide fast, accurate and low-cost transduction of the analyte binding events into electronic signals. The concept is demonstrated for detection of three sulfur derivatives – dimethyl disulfide, ethanethiol and methylsulfide. PMID:20160943

Rai, Anant; Tsow, Francis; Nassirpour, Sanam; Bankers, Jeffrey; Spinatsch, Martina; He, M. Pete; Forzani, Erica; Tao, N. J.

2009-01-01

394

METHOD TO PREVENT SULFUR ACCUMULATION INSIDE MEMBRANE ELECTRODE ASSEMBLY  

SciTech Connect

HyS is conceptually the simplest of the thermochemical cycles and involves only sulfur chemistry. In the HyS Cycle hydrogen gas (H{sub 2}) is produced at the cathode of the electrochemical cell (or electrolyzer). Sulfur dioxide (SO{sub 2}) is oxidized at the anode to form sulfuric acid (H{sub 2}SO{sub 4}) and protons (H{sup +}) as illustrated below. A separate high temperature reaction decomposes the sulfuric acid to water and sulfur dioxide which are recycled to the electrolyzers, and oxygen which is separated out as a secondary product. The electrolyzer includes a membrane that will allow hydrogen ions to pass through but block the flow of hydrogen gas. The membrane is also intended to prevent other chemical species from migrating between electrodes and undergoing undesired reactions that could poison the cathode or reduce overall process efficiency. In conventional water electrolysis, water is oxidized at the anode to produce protons and oxygen. The standard cell potential for conventional water electrolysis is 1.23 volts at 25 C. However, commercial electrolyzers typically require higher voltages ranging from 1.8 V to 2.6 V [Kirk-Othmer, 1991]. The oxidation of sulfur dioxide instead of water in the HyS electrolyzer occurs at a much lower potential. For example, the standard cell potential for sulfur dioxide oxidation at 25 C in 50 wt % sulfuric acid is 0.29 V [Westinghouse, 1980]. Since power consumption by the electrolyzers is equal to voltage times current, and current is proportional to hydrogen production, a large reduction in voltage results in a large reduction in electrical power cost per unit of hydrogen generated.

Steimke, J.; Steeper, T.; Herman, D.; Colon-Mercado, H.; Elvington, M.

2009-06-22

395

Adsorptive removal of sulfur compounds using IRMOF-3 at ambient temperature  

NASA Astrophysics Data System (ADS)

Zinc-based metal-organic framework (IRMOF-3) was used as adsorbent for removal of dimethyl sulfide, ethyl mercaptan and hydrogen sulfide in fixed bed reactor at ambient temperature. These samples before and after exposure to sulfur compounds were characterized by Fourier transform infrared (FTIR), and X-ray diffraction (XRD), and thermo gravimetric (TG), and X-ray photoelectron spectroscopy (XPS). The results show that IRMOF-3 exhibit the best performance for hydrogen sulfide removal with the highest breakthrough sulfur capacity, followed by ethyl mercaptan and dimethyl sulfide. This is in consistent with the interaction strength between IRMOF-3 and sulfur compounds. In the case of dimethyl sulfide and ethyl mercaptan, the interaction comes from the weak interaction between the amino group in the MOFs and the sulfur atom of the adsorbate. This can also be considered as a hydrogen bond complex in which the amino group in the MOFs and the S atom of the sulfur compounds play the role of H-donor and H-acceptor, respectively. In the case of hydrogen sulfide, the interaction with sulfur atom originates from the amino group and zinc site in the MOFs. The former is more like an acid-base interaction, whereas the latter results in new products of ZnS and H2O and serious destruction of the MOFs.

Wang, Xiao-Ling; Fan, Hui-Ling; Tian, Zhen; He, En-Yun; Li, Ye; Shangguan, Ju

2014-01-01

396

Inhibition of microbiological sulfide oxidation by methanethiol and dimethyl polysulfides at natron-alkaline conditions.  

PubMed

To avoid problems related to the discharge of sulfidic spent caustics, a biotechnological process is developed for the treatment of gases containing both hydrogen sulfide and methanethiol. The process operates at natron-alkaline conditions (>1 mol L(-1) of sodium- and potassium carbonates and a pH of 8.5-10) to enable the treatment of gases with a high partial CO(2) pressure. In the process, methanethiol reacts with biologically produced sulfur particles to form a complex mixture predominantly consisting of inorganic polysulfides, dimethyl disulfide (DMDS), and dimethyl trisulfide (DMTS). The effect of these organic sulfur compounds on the biological oxidation of sulfide to elemental sulfur was studied with natron-alkaliphilic bacteria belonging to the genus Thioalkalivibrio. Biological oxidation rates were reduced by 50% at 0.05 mM methanethiol, while for DMDS and DMTS, this was estimated to occur at 1.5 and 1.0 mM, respectively. The inhibiting effect of methanethiol on biological sulfide oxidation diminished due to its reaction with biologically produced sulfur particles. This reaction increases the feasibility of biotechnological treatment of gases containing both hydrogen sulfide and methanethiol at natron-alkaline conditions. PMID:19333598

van den Bosch, Pim L F; de Graaff, Marco; Fortuny-Picornell, Marc; van Leerdam, Robin C; Janssen, Albert J H

2009-06-01

397

40 CFR 721.10099 - Dialkyl dimethyl ammonium carbonate (generic).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Dialkyl dimethyl ammonium carbonate (generic). 721.10099...Substances § 721.10099 Dialkyl dimethyl ammonium carbonate (generic). (a) Chemical...identified generically as dialkyl dimethyl ammonium carbonate (1:1) (PMN...

2010-07-01

398

40 CFR 721.333 - Dimethyl alkylamine salt (generic).  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Dimethyl alkylamine salt (generic). 721.333 Section 721...Substances § 721.333 Dimethyl alkylamine salt (generic). (a) Chemical substance...identified generically as a Dimethyl alkylamine salt (PMNs P-99-0368 and...

2014-07-01

399

40 CFR 721.333 - Dimethyl alkylamine salt (generic).  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Dimethyl alkylamine salt (generic). 721.333 Section 721...Substances § 721.333 Dimethyl alkylamine salt (generic). (a) Chemical substance...identified generically as a Dimethyl alkylamine salt (PMNs P-99-0368 and...

2012-07-01

400

40 CFR 721.333 - Dimethyl alkylamine salt (generic).  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Dimethyl alkylamine salt (generic). 721.333 Section 721...Substances § 721.333 Dimethyl alkylamine salt (generic). (a) Chemical substance...identified generically as a Dimethyl alkylamine salt (PMNs P-99-0368 and...

2011-07-01

401

40 CFR 721.333 - Dimethyl alkylamine salt (generic).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Dimethyl alkylamine salt (generic). 721.333 Section 721...Substances § 721.333 Dimethyl alkylamine salt (generic). (a) Chemical substance...identified generically as a Dimethyl alkylamine salt (PMNs P-99-0368 and...

2010-07-01

402

Photodissociation dynamics of dimethyl disulfide  

NASA Astrophysics Data System (ADS)

We present the resonance Raman spectrum of dimethyl disulfide excited with 266 nm laser light. The spectrum contains a progression of ten peaks assigned to the C-S stretch mode. This suggests that the initial motion of the dissociating molecule out of the Franck-Cordon region stretches the C-S bond. This interpretation is supported by semi-empirical calculations of the first excited singlet potential energy surface. The calculations suggest the next highest excited singlet state dissociates along the S-S bond, in agreement with work at shorter wavelengths by other workers.

Rinker, Adam; Halleman, Christopher D.; Wedlock, Michael R.

2005-10-01

403

Radio detection of interstellar dimethyl ether  

NASA Technical Reports Server (NTRS)

The detection of interstellar dimethyl ether, in emission from the direction of the Orion Nebula molecular cloud, is reported. The largest molecule detected in space, dimethyl ether has a large collisional cross section and C (sub 2V) symmetry. Hence, it should be useful for future studies of molecular pumping models.

Snyder, L. E.; Buhl, D.; Schwartz, P. R.; Clark, F. O.; Johnson, D. R.; Lovas, F. J.; Giguere, P. T.

1974-01-01

404

Process and apparatus for generating elemental sulfur and re-usable metal oxide from spent metal sulfide sorbents  

DOEpatents

A process and apparatus for generating elemental sulfur and re-usable metal oxide from spent metal-sulfur compound. Spent metal-sulfur compound is regenerated to re-usable metal oxide by moving a bed of spent metal-sulfur compound progressively through a single regeneration vessel having a first and second regeneration stage and a third cooling and purging stage. The regeneration is carried out and elemental sulfur is generated in the first stage by introducing a first gas of sulfur dioxide which contains oxygen at a concentration less than the stoichiometric amount required for complete oxidation of the spent metal-sulfur compound. A second gas containing sulfur dioxide and excess oxygen at a concentration sufficient for complete oxidation of the partially spent metal-sulfur compound, is introduced into the second regeneration stage. Gaseous sulfur formed in the first regeneration stage is removed prior to introducing the second gas into the second regeneration stage. An oxygen-containing gas is introduced into the third cooling and purging stage. Except for the gaseous sulfur removed from the first stage, the combined gases derived from the regeneration stages which are generally rich in sulfur dioxide and lean in oxygen, are removed from the regenerator as an off-gas and recycled as the first and second gas into the regenerator. Oxygen concentration is controlled by adding air, oxygen-enriched air or pure oxygen to the recycled off-gas.

Ayala, Raul E. (Clifton Park, NY); Gal, Eli (Lititz, PA)

1995-01-01

405

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

406

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 ...

407

SUMMARY REPORT: SULFUR OXIDES CONTROL TECHNOLOGY SERIES: FLUE GAS DESULFURIZATION - SPRAY DRYER PROCESS  

EPA Science Inventory

Described spray dryer flue gas desulfurization (FGD), which is a throwaway process in which sulfur dioxide (SO2) is removed from flue gas by an atomized lime slurry [Ca(OH)2]. he hot flue gas dries the droplets to form a dry waste product, while the absorbent reacts with sulfur d...

408

Phase transitions in a bed of vanadium catalyst for sulfuric acid production: experiment and modeling  

Microsoft Academic Search

Sulfur dioxide oxidation on vanadium catalysts in sulfuric acid production may cause phase transitions in the catalyst active component. These phase transitions involve crystallization of vanadium(IV), and may influence catalyst activity. In the present study, we show that reaction mixture flow through a fixed catalyst bed is accompanied by the moving front of crystal phase, which decreases SO2 conversion at

B. S. Bal’zhinimaev; N. P. Belyaeva; S. I. Reshetnikov; E. S. Yudina; A. A. Ivanov

2001-01-01

409

EVALUATION OF MONITORING SYSTEMS FOR POWER PLANT AND SULFUR RECOVERY PLANT EMISSIONS  

EPA Science Inventory

This project was conducted to evaluate a number of commercially available extractive-type sampling and monitoring systems for monitoring sulfur dioxide and hydrogen sulfide source emissions. Evaluation testing was performed at a Fossil Fuel-Fired Power Plant and at a Claus Sulfur...

410

Sulfur and sulfur compounds in plant defence.  

PubMed

The multiplicity of chemical structures of sulfur containing compounds, influenced in part by the element's several oxidation states, directly results in diverse modes of action for sulfur-containing natural products synthesized as secondary metabolites in plants. Sulfur-containing natural products constitute a formidable wall of defence against a wide range of pathogens and pests. Steady progress in the development of new technologies have advanced research in this area, helping to uncover the role of such important plant defence molecules like endogenously-released elemental sulphur, but also deepening current understanding of other better-studied compounds like the glucosinolates. As studies continue in this area, it is becoming increasingly evident that sulfur and sulfur compounds play far more important roles in plant defence than perhaps previously suspected. PMID:22545416

Nwachukwu, Ifeanyi D; Slusarenko, Alan J; Gruhlke, Martin C H

2012-03-01

411

Reductive desorption of sulfuric acid formed on the carbon catalyst in flue gas desulfurization (FGD)  

Microsoft Academic Search

Reductive desorption of sulfuric acid formed on the carbon catalyst in flue gas desulfurization (FGD) by heating with hydrogen at 3: 200Ā°C converted the acid to gas-phase sulfur dioxide with a significant loss of the acid to hydrogen sulfide and elemental sulfur. These side reactions were suppressed and the temperature required for SOā recovery was reduced by impregnating the charcoal

S. Yoshizawa; A. Karagiri; K. Watanabe

1979-01-01

412

Dimethyl sulfide oxidation in the equatorial Pacific: Comparison of model simulations with field observations for DMS, SO2, H2SO4(g), MSA(g), MS, and NSS  

NASA Astrophysics Data System (ADS)

Reported here are results from an airborne photochemical/sulfur field study in the equatorial Pacific. This study was part of NASA's Global Tropospheric Experiment (GTE) Pacific Exploratory Mission (PEM) Tropics A program. The focus of this paper is on data gathered during an airborne mission (P-3B flight 7) near the Pacific site of Christmas Island. Using a Lagrangian-type sampling configuration, this sortie was initiated under pre-sunrise conditions and terminated in early afternoon with both boundary layer (BL) as well as buffer layer (BuL) sampling being completed. Chemical species sampled included the gas phase sulfur species dimethyl sulfide (DMS), sulfur dioxide (SO2), methane sulfonic acid (MSA)g, and sulfuric acid (H2SO4)g. Bulk aerosol samples were collected and analyzed for methane sulfonate (MS), non-sea-salt sulfate (NSS), Na+,Cl-, and NH4+. Critical non-sulfur parameters included real-time sampling of the hydroxyl radical (OH) and particle size/number distributions. These data showed pre-sunrise minima in the mixing ratios for OH, SO2, and H2SO4 and post-sunrise maxima in the levels of DMS, OH, and H2SO4. Thus, unlike several previous studies involving coincidence DMS and SO2 measurements, the Christmas Island data revealed that DMS and SO2 were strongly anticorrelated. Our "best estimate" of the overall efficiency for the conversion of DMS to SO2 is 72±22%. These results clearly demonstrate that DMS was the dominant source of SO2 in the marine BL. Using as model input measured values for SO2 and OH, the level of agreement between observed and simulated BL H2SO4(g) profiles was shown to be excellent. This finding, together with supporting correlation analyses, suggests that the dominant sulfur precursor for formation of H2SO4 is SO2 rather than the more speculative sulfur species, SO3. Optimization of the fit between the calculated and observed H2SO4 values was achieved using a H2SO4 first-order loss rate of 1.3 × 10-3 s-1. On the basis of an estimated total "wet" aerosol surface area of 75 µm2/cm3, a H2SO4 sticking coefficient of 0.6 was evaluated at a relative humidity of ?95%, in excellent agreement with recent laboratory measurements. The Christmas Island data suggest that over half of the photochemically generated SO2 forms NSS, but that both BL NSS and MS levels are predominantly controlled by heterogeneous processes involving aerosols. In the case of MS, the precursors species most likely responsible are the unmeasured oxidation products dimethyl sulfoxide (DMSO) and methane sulfinic acid (MSIA). Gas phase production of MSA was shown to account for only 1% of the observed MS; whereas gas phase produced H2SO4 accounted for ˜20% of the NSS. These results are of particular significance in that BL-measured values of the ratio MS/NSS have often been used to estimate the fraction of NSS derived from biogenic DMS and to infer the temperature environment where DMS oxidation occurred. If our conclusions are correct and both products are predominantly formed from complex and still poorly characterized heterogeneous processes, it would suggest that for some environmental settings a simple interpretation of this ratio might be subject to considerable error.

Davis, D.; Chen, G.; Bandy, A.; Thornton, D.; Eisele, F.; Mauldin, L.; Tanner, D.; Lenschow, D.; Fuelberg, H.; Huebert, B.; Heath, J.; Clarke, A.; Blake, D.

1999-03-01

413

Laboratory investigation of the atmospheric oxidation of dimethyl sulfide  

NASA Astrophysics Data System (ADS)

On a global scale dimethyl sulfide (DMS, CH3SCH3) is the largest natural source of reduced gas phase sulfur and this compound may play an important role in cloud and aerosol formation processes through its atmospheric oxidation products. Clouds and aerosol constitute a major component of the global climate system via the earth's radiation budget. The work comprising this dissertation entails kinetic, spectroscopic, and mechanistic studies of sulfur containing compounds that are key intermediates in the atmospheric oxidation of DMS. The goal of this dissertation is to improve the quantitative understanding of the DMS atmospheric oxidation mechanism through the determination of rate coefficients and product yields of important elementary gas phase reactions. The experimental approach employed utilized laser flash photolysis (LFP) to initiate free radical chemistry coupled with tune-resolved tunable diode laser spectroscopy (TDLAS) and/or time-resolved UV-VIS long path absorption spectroscopy (LPAS) to monitor the time dependent concentrations of reactants or products. Key reactions examined in this dissertation research include: OH + CH3S(O)CH3, CH3SCH2OO + CH 3SCH2OO, Cl- S(CH3)2+ O2/NO/NO 2. Chemical species monitored in the course of these studies include SO2, CH4, HCL CH2O, and CH3 by TDLAS and CH3OO and Cl-S(CH3)2 using UV-VIS absorption spectroscopy.

Urbanski, Shawn Peter

1999-11-01

414

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

415

Biochemistry of sulfur  

SciTech Connect

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

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

1986-01-01

416

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

417

Paramagnetic oxides of nitrogen observed in a sulfur hexafluoride matrix  

Microsoft Academic Search

gamma.. irradiation of a solid solution of nitrogen dioxide in sulfur hexafluoride generates a number of paramagnetic nitrogen oxides which exhibit isotropic EPR spectra at 110Ā°K. The radicals NOā, NOā, and FāNO have been positively identified, and a fourth species, hitherto unknown, is believed to be a radical ion of nitrosyl nitrate, ONONOā\\/sup +-\\/. 1 figure, 1 table.

J. R. Morton; K. F. Preston; S. J. Strach

1979-01-01

418

Sulfur and nitrogen reactions for cometary comae ion chemistry  

NASA Technical Reports Server (NTRS)

The low pressure reactions of sulfur dioxide, carbon disulfide, and hydrazine with H2O+ and H3O+ were studied by the ion cyclotron resonance technique. These reactions are potentially important for sulphur chemistry in cometary comae. Rate coefficients and branching ratios of product channels are presented.

Sen, A. D.; Anicich, V. G.

1992-01-01

419

Isotopic analysis of dimethyl selenide  

SciTech Connect

The separated isotopes of selenium may be used as stable precursors for the synthesis of radio-bromine isotopes for positron emitter tomographic diagnostics. As part of a project to find a suitable distillation method for separating selenium isotopes, the need arose to study the organo-metallic compound dimethyl selenide. The complexity of the mass spectrum tended to obscure the isotope effect with 35 major peaks being measured. A least-squares fitting procedure was developed for the 13 fragmentation factors as well as a few hundredths of a percent, yet no sizeable separation was observed across the test column. According to these measurements, the effect of one mass unit increase in the selenium isotope results in less than 10 ppM in the vapor pressure of the compound. 4 figures.

McInteer, B.B.

1984-01-01

420

Microbial Decomposition of Methionine and Identity of the Resulting Sulfur Products1  

PubMed Central

Various bacteria, actinomycetes, and filamentous fungi decomposed methionine, but only certain aerobic bacteria isolated from soil decomposed it in the absence of other organic substrates. These bacteria could grow on methionine as the only organic substrate and source of nitrogen and sulfur. Methionine was first deaminated and then demethiolated with production of methanethiol, part of which was oxidized to dimethyl disulfide. The amount of methanethiol that was oxidized varied with different cultures. A bacterial culture initially unable to grow on methionine developed capacity to do this in a medium which contained methionine and other growth substrates. The two sulfur products, methanethiol and dimethyl disulfide, are volatile and escaped from the media, resulting in a decrease in the sulfur content proportional to the amount of methionine decomposed. PMID:5788717

Segal, William; Starkey, Robert L.

1969-01-01

421

Methylated sulfur compounds in microbial mats: in situ concentrations and metabolism by a colorless sulfur bacterium.  

PubMed Central

The concentrations of the volatile organic sulfur compounds methanethiol, dimethyl disulfide, and dimethyl sulfide (DMS) and the viable population capable of DMS utilization in laminated microbial ecosystems were evaluated. Significant levels of DMS and dimethyl disulfide (maximum concentrations of 220 and 24 nmol cm3 of sediment-1, respectively) could be detected only at the top 20 mm of the microbial mat, whereas methanethiol was found only at depth horizons from 20 to 50 mm (maximum concentration of 42 nmol cm3 of sediment-1). DMS concentrations in the surface layer doubled after cold hydrolysis of its precursor, dimethylsulfoniopropionate. Most-probable-number counts revealed 2.2 x 10(5) cells cm3 of sediment-1, in the 0- to 5-mm depth horizon, capable of growth on DMS as the sole source of energy. An obligately chemolithoautotrophic bacillus designated strain T5 was isolated from the top layer of the marine sediment. Continuous culture studies in which DMS was the growth-limiting substrate revealed a maximum specific growth rate of 0.10 h-1 and a saturation constant of 90 mumol liter-1 for aerobic growth on this substrate. PMID:1872604

Visscher, P T; Quist, P; van Gemerden, H

1991-01-01

422

In situ Raman spectroscopy of sulfur speciation in lithium-sulfur batteries.  

PubMed

In situ Raman spectroscopy and cyclic voltammetry were used to investigate the mechanism of sulfur reduction in lithium-sulfur battery slurry cathodes with 1 M lithium bis(trifluoromethane sulfonyl)imide (LiTFSI) and tetraethylene glycol dimethyl ether (TEGDME)/1,3-dioxolane (DIOX) (1/1, v/v). Raman spectroscopy shows that long-chain polysulfides (S8(2-)) were formed via S8 ring opening in the first reduction process at ?2.4 V vs Li/Li(+) and short-chain polysulfides such as S4(2-), S4(-), S3(•-), and S2O4(2-) were observed with continued discharge at ?2.3 V vs Li/Li(+) in the second reduction process. Elemental sulfur can be reformed in the end of the charge process. Rate constants obtained for the appearance and disappearance polysulfide species shows that short-chain polysulfides are directly formed from S8 decomposition. The rate constants for S8 reappearance and polysulfide disappearance on charge were likewise similar. The formation of polysulfide mixtures at partial discharge was found to be quite stable. The CS2 additive was found to inhibit the sulfur reduction mechanism allowing the formation of long-chain polysulfides during discharge only and stabilizing the S8(2-) product. PMID:25543831

Wu, Heng-Liang; Huff, Laura A; Gewirth, Andrew A

2015-01-28

423

OH-induced oxidative cleavage of dimethyl disulfide in the presence of NO.  

PubMed

We report the results of the theoretical study of (•)OH-induced oxidative cleavage of dimethyl disulfide (DMDS) and the experimental study of the CH3SSCH3 + (•)OH reaction in the presence of (•)NO. Infrared low temperature argon matrix studies combined with ab initio calculations allowed us to identify cis-CH3SONO, which evidences the formation of the CH3SO(•) and CH3SH molecules in the course of the CH3SSCH3 + (•)OH reaction. Ab initio/quantum chemical topology calculations revealed details of the oxidative cleavage of dimethyl disulfide, which is a complex multistep process involving an alteration of S-O and S-S covalent bonds as well as a hydrogen atom transfer. The ability of delocalization of the unpaired electron density by sulfur atoms and a formation of a hydrogen bond by CH3SO(•) and CH3SH are the factors which seem to explain antiradical properties of DMDS. PMID:23947660

Bil, Andrzej; Grzechnik, Katarzyna; Mierzwicki, Krzysztof; Mielke, Zofia

2013-08-29

424

Integrating entrapped mixed microbial cell (EMMC) technology for treatment of wastewater containing dimethyl sulfoxide (DMSO) for reuse in semiconductor industries  

Microsoft Academic Search

Solvents containing dimethyl sulfoxide (DMSO) are widely used in the rinse process of stripping photoresistors in semiconductor\\u000a manufacturing industries. The disposal\\/reuse of wastewater containing DMSO is a serious problem because of its high concentration\\u000a of organic carbon and the need to suppress the odor from its sulfur contents. An entrapped mixed microbial cell (EMMC) process\\u000a was used to investigate the

P. Y. Yang; Tin Tin Myint

2003-01-01

425

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

PubMed Central

Methanethiol, dimethyl sulfide, dimethyl disulfide, and hydrogen sulfide were efficiently removed from contaminated air by Thiobacillus thioparus TK-m and oxidized to sulfate stoichiometrically. More than 99.99% of dimethyl sulfide was removed when the load was less than 4.0 g of dimethyl sulfide per g (dry cell weight) per day. PMID:2930168

Kanagawa, T; Mikami, E

1989-01-01

426

40 CFR 52.675 - Control strategy: Sulfur oxides-Eastern Idaho Intrastate Air Quality Control Region.  

Code of Federal Regulations, 2013 CFR

...and Regulations for the Control of Air Pollution in Idaho, which is part of the...Regulations for the Control of Air Pollution in Idaho” are inadequate to ensure...Sulfur Dioxide National Ambient Air Quality Standards in the...

2013-07-01

427

40 CFR 52.675 - Control strategy: Sulfur oxides-Eastern Idaho Intrastate Air Quality Control Region.  

Code of Federal Regulations, 2014 CFR

...and Regulations for the Control of Air Pollution in Idaho, which is part of the...Regulations for the Control of Air Pollution in Idaho” are inadequate to ensure...Sulfur Dioxide National Ambient Air Quality Standards in the...

2014-07-01

428

40 CFR 52.675 - Control strategy: Sulfur oxides-Eastern Idaho Intrastate Air Quality Control Region.  

Code of Federal Regulations, 2012 CFR

...and Regulations for the Control of Air Pollution in Idaho, which is part of the...Regulations for the Control of Air Pollution in Idaho” are inadequate to ensure...Sulfur Dioxide National Ambient Air Quality Standards in the...

2012-07-01

429

40 CFR 52.675 - Control strategy: Sulfur oxides-Eastern Idaho Intrastate Air Quality Control Region.  

Code of Federal Regulations, 2011 CFR

...and Regulations for the Control of Air Pollution in Idaho, which is part of the...Regulations for the Control of Air Pollution in Idaho” are inadequate to ensure...Sulfur Dioxide National Ambient Air Quality Standards in the...

2011-07-01

430

40 CFR 52.675 - Control strategy: Sulfur oxides-Eastern Idaho Intrastate Air Quality Control Region.  

Code of Federal Regulations, 2010 CFR

...and Regulations for the Control of Air Pollution in Idaho, which is part of the...Regulations for the Control of Air Pollution in Idaho” are inadequate to ensure...Sulfur Dioxide National Ambient Air Quality Standards in the...

2010-07-01

431

Development status of electrolysis technology for the sulfur cycle hydrogen production process  

NASA Astrophysics Data System (ADS)

The Sulfur Cycle Hydrogen Production Process comprises an electrochemical and a thermochemical reaction. In an electrolysis cell, sulfur dioxide dissolved in aqueous solutions is electrochemically oxidized to sulfuric acid at the anode, while hydrogen gas is evolved at the cathode. By use of thermal energy from a high-temperature heat source, sulfuric acid produced in the electrolyzer is vaporized and catalytically decomposed to form sulfur dioxide, water and oxygen. Four approaches for improving electrolysis technology are considered, including an electrochemical study of catalysts, the development of electrode fabrication processes, the optimization of cell configuration, and the selection and investigation of separator materials. Palladium and palladium oxide were found to be superior to platinum as electrocatalysts for SO2 oxidation.

Lu, P. W. T.; Ammon, R. L.

432

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

PubMed

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

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

2013-01-01

433

Determination of total sulfur in lichens and plants by combustion-infrared analysis. [Medicago sativa L. ; Vitis labruscana Bailey; Festuca sp. ; Fraxinum pennsylvanica Marsh. ; Paremelia chlorochroa Tuck. ; P. sulcata Tayl. ; Juniperus scopulorum Sarg. ; Artemisia tridentata Nuttl; Lycopersicum esculentum Mill. ; Triticum compactum Host; Agropyron smithii Rydb. ; Salix pulchra Cham  

Microsoft Academic Search

Sulfur was determined in plants and lichens by combustion of the sample and infrared detection of evolved sulfur dioxide using an automated sulfur analyzer. Vanadium pentaoxide was used as a combustion accelerator. Pelletization of the sample prior to combustion was not found to be advantageous. Washing studies showed that leaching of sulfur was not a major factor in the sample

L. L. Jackson; E. E. Engleman; J. L. Peard

1985-01-01

434

A Passive Sampler for Determination of Nitrogen Dioxide in Ambient Air  

ERIC Educational Resources Information Center

A passive sampler that provides a convenient, simple, and fast method for nitrogen dioxide determination is proposed. The experiment can be modified for determinations of other air pollutants like formaldehyde and sulfur dioxide for hands-on experience for students studying environmental pollution problems.

Xiao, Dan; Lin, Lianzhi; Yuan, Hongyan; Choi, Martin M. F.; Chan, Winghong

2005-01-01

435

Sulfur isotopic data  

SciTech Connect

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

Rye, R.O.

1987-01-01

436

Thermodynamic Properties of Dimethyl Carbonatea)  

NASA Astrophysics Data System (ADS)

A thermodynamic property formulation for dimethyl carbonate has been developed with the use of available experimental thermodynamic property data. The equation of state was developed with multiproperty fitting methods involving pressure-density-temperature (p?T), heat capacity, vapor pressure, and saturated-liquid density data. The equation of state conforms to the Maxwell criterion for two-phase liquid-vapor equilibrium states, and is valid for temperatures from the triple-point temperature (277.06 ± 0.63) K to 600 K, for pressures up to 60 MPa, and for densities up to 12.12 mol dm-3. The extrapolation behavior of the equation of state at low and high temperatures and pressures is reasonable. The uncertainties (k = 2, indicating a 95% confidence level) of the equation of state in density are 0.05% for saturated-liquid states below 350 K, rising to 0.1% in the single phase between 278 K and 400 K at pressures up to 60 MPa. Due to the lack of reliable data outside this region, the estimated uncertainties increase to 0.5% to 1% in the vapor and critical regions. The uncertainties in vapor pressure are 0.6% from 310 K to 400 K, and increase to 1% at higher temperatures and to 2% at lower temperatures due to a lack of experimental data. The uncertainty in isobaric heat capacity and speed of sound in the liquid phase at saturation or atmospheric pressure is 0.5% from 280 K to 335 K. The uncertainties are higher for all properties in the critical region. Detailed comparisons between experimental and calculated data, and an analysis of the equation, have been performed.

Zhou, Yong; Wu, Jiangtao; Lemmon, Eric W.

2011-12-01

437

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

438

Identification of sulfur fumed Pinelliae Rhizoma using an electronic nose  

PubMed Central

Background: Pinelliae Rhizoma is a commonly used Chinese herb which will change brown during the natural drying process. However, sulfur fumed Pinelliae Rhizoma will get a better appearance than naturally dried one. Sulfur fumed Pinelliae Rhizoma is potentially toxical due to sulfur dioxide and sulfites formed during the fuming procedures. The odor components in sulfur fumed Pinelliae Rhizoma is complex. At present, there is no analytical method available to determine sulfur fumed Pinelliae Rhizoma simply and rapidly. To ensure medication safety, it is highly desirable to have an effective and simple method to identify sulfur fumed Pinelliae Rhizoma. Materials and Methods: This paper presents a novel approach using an electronic nose based on metal oxide sensors to identify whether Pinelliae Rhizoma was fumed with sulfur, and to predict the fuming degree of Pinelliae Rhizoma. Multivariate statistical methods such as principal components analysis (PCA), discriminant factorial analysis (DFA) and partial least squares (PLS) were used for data analyzing and identification. The use of the electronic nose to discriminate between different fuming degrees Pinelliae Rhizoma and naturally dried Pinelliae Rhizoma was demonstrated. Results: The electronic nose was also successfully applied to identify unknown samples including sulfur fumed samples and naturally dried samples, high recognition value was obtained. Quantitative analysis of fuming degree of Pinelliae Rhizoma was also demonstrated. The method developed is simple and fast, which provides a new quality control method of Chinese herbs from the aspect of odor. Conclusion: It has shown that this electronic nose based metal oxide sensor is sensitive to sulfur and sulfides. We suggest that it can serve as a supportive method to detect residual sulfur and sulfides. PMID:24914293

Zhou, Xia; Wan, Jun; Chu, Liang; Liu, Wengang; Jing, Yafeng; Wu, Chunjie

2014-01-01

439

CLOSEOUT REPORT FOR HYBRID SULFUR PRESSURIZED BUTTON CELL TEST FACILITY  

SciTech Connect

This document is the Close-Out Report for design and partial fabrication of the Pressurized Button Cell Test Facility at Savannah River National Laboratory (SRNL). This facility was planned to help develop the sulfur dioxide depolarized electrolyzer (SDE) that is a key component of the Hybrid Sulfur Cycle for generating hydrogen. The purpose of this report is to provide as much information as possible in case the decision is made to resume research. This report satisfies DOE Milestone M3GSR10VH030107.0. The HyS Cycle is a hybrid thermochemical cycle that may be used in conjunction with advanced nuclear reactors or centralized solar receivers to produce hydrogen by watersplitting. The HyS Cycle utilizes the high temperature (>800 C) thermal decomposition of sulfuric acid to produce oxygen and regenerate sulfur dioxide. The unique aspect of HyS is the generation of hydrogen in a water electrolyzer that is operated under conditions where dissolved sulfur dioxide depolarizes the anodic reaction, resulting in substantial voltage reduction. Low cell voltage is essential for both high thermodynamic efficiency and low hydrogen cost. Sulfur dioxide is oxidized at the anode, producing sulfuric acid that is sent to the high temperature acid decomposition portion of the cycle. Sulfur dioxide from the decomposer is cycled back to electrolyzers. The electrolyzer cell uses the membrane electrode assembly (MEA) concept. Anode and cathode are formed by spraying a catalyst, typically platinized carbon, on both sides of a Proton Exchange Membrane (PEM). SRNL has been testing SDEs for several years including an atmospheric pressure Button Cell electrolyzer (2 cm{sup 2} active area) and an elevated temperature/pressure Single Cell electrolyzer (54.8 cm{sup 2} active area). SRNL tested 37 MEAs in the Single Cell electrolyzer facility from June 2005 until June 2009, when funding was discontinued. An important result of the final months of testing was the development of a method that prevents the formation of a sulfur layer previously observed in MEAs used in the Hybrid Sulfur Cycle electrolyzer. This result is very important because the sulfur layer increased cell voltage and eventually destroyed the MEA that is the heart of the cell. Steimke and Steeper [2005, 2006, 2007, 2008] reported on testing in the Single Cell Electrolyzer test facility in several periodic reports. Steimke et. al [2010] issued a final facility close-out report summarizing all the testing in the Single Cell Electrolyzer test facility. During early tests, significant deterioration of the membrane occurred in 10 hours or less; the latest tests ran for at least 200 hours with no sign of deterioration. Ironically, the success with the Single Cell electrolyzer meant that it became dedicated to long runs and not available for quick membrane evaluations. Early in this research period, the ambient pressure Button Cell Electrolyzer test facility was constructed to quickly evaluate membrane materials. Its small size allowed testing of newly developed membranes that typically were not available in sizes large enough to test in the Single Cell electrolyzer. The most promising membranes were tested in the Single Cell Electrolyzer as soon as sufficient large membranes could be obtained. However, since the concentration of SO{sub 2} gas in sulfuric acid decreases rapidly with increasing temperature, the ambient pressure Button Cell was no longer able to achieve the operating conditions needed to evaluate the newer improved high temperature membranes. Significantly higher pressure operation was required to force SO{sub 2} into the sulfuric acid to obtain meaningful concentrations at increased temperatures. A high pressure (200 psig), high temperature (120 C) Button Cell was designed and partially fabricated just before funding was discontinued in June 2009. SRNL completed the majority of the design of the test facility, including preparation of a process and instrument drawing (P&ID) and preliminary designs for the major components. SRNL intended to complete the designs and procu

Steeper, T.

2010-09-15

440

Positive and negative ion formation in deep-core excited molecules: S 1s excitation in dimethyl sulfoxide  

NASA Astrophysics Data System (ADS)

The photo-fragmentation of the dimethyl sulfoxide (DMSO) molecule was studied using synchrotron radiation and a magnetic mass spectrometer. The total cationic yield spectrum was recorded in the photon energy region around the sulfur K edge. The sulfur composition of the highest occupied molecular orbital's and lowest unoccupied molecular orbital's in the DMSO molecule has been obtained using both ab initio and density functional theory methods. Partial cation and anion-yield measurements were obtained in the same energy range. An intense resonance is observed at 2475.4 eV. Sulfur atomic ions present a richer structure around this resonant feature, as compared to other fragment ions. The yield curves are similar for most of the other ionic species, which we interpret as due to cascade Auger processes leading to multiply charged species which then undergo Coulomb explosion. The anions S-, C-, and O- are observed for the first time in deep-core-level excitation of DMSO.

Coutinho, L. H.; Gardenghi, D. J.; Schlachter, A. S.; de Souza, G. G. B.; Stolte, W. C.

2014-01-01

441

Sulfuric Acid on Europa  

NASA Technical Reports Server (NTRS)

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

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

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

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

1999-01-01

442

40 CFR 721.4133 - Dimethyl-3-substituted heteromonocyclic amine.  

Code of Federal Regulations, 2010 CFR

40 Protection of Environment 30...Dimethyl-3-substituted heteromonocyclic amine. 721.4133 Section 721.4133 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED...Dimethyl-3-substituted heteromonocyclic amine. (a)...

2010-07-01

443

Photochemistry of iron in simulated crustal aerosols with dimethyl sulfide oxidation products.  

PubMed

Iron contained in dust-derived aerosol particles deposited into remote oceans is essential for phytoplankton productivity, which controls photosynthesis rate and the uptake and release of climate forcing gases. Understanding chemical mechanisms that control iron bioavailability, that is, its speciation, is therefore crucial for global climate predictions. In the present study, the photoredox chemistry of iron in marine atmospheric aerosol particles was investigated by using ferrihydrite as a surrogate iron phase in the presence of dimethyl sulfide (DMS) derived oxidation products: dimethyl sulfoxide (DMSO), dimethyl sulfone (DMS02), methane sulfinic acid (MSIA), and methane sulfonic acid (MSA). Reactants and products were analyzed with UV-vis absorption spectroscopy, ion chromatography, and a hydrogen peroxide sensitive electrode. Results show that MSIA enhances the photoreductive dissolution of iron in a ligand-to-metal charge transfer reaction producing Fe(II), MSA, and H2O2. The rate law for Fe(II) is close to first order (0.79) with regard to adsorbed MSIA and has an empirical rate constant of 1.4 x 10(-4) s(-1). This mechanism may represent a significant pathway through which iron becomes more bioavailable, and it contributes to models of iron and sulfur chemistries in the marine atmosphere. PMID:18350887

Key, Jennifer M; Paulk, Nicole; Johansen, Anne M

2008-01-01

444