Note: This page contains sample records for the topic sulfur dioxide dimethyl from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

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

Microsoft Academic Search

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

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

1993-01-01

2

Natural sulfur flux from the Gulf of Mexico: dimethyl sulfide, carbonyl sulfide, and sulfur dioxide. Technical report  

SciTech Connect

Atmospheric measurements of natural sulfur compounds were performed over the northern Gulf of Mexico during the late summer months of 1984. Air samples were collected with an instrumented aircraft at elevations of 30-3500 m, during both day and night. Most air samples were representative of the clean maritime atmosphere, although some were from continental contaminated air during periods of offshore flow at the coastline. In all samples, carbonyl sulfide concentrations were within the range of 400-500 pptv. Conversely, the dimethyl sulfide concentrations showed significant variability: during clean atmospheric conditions the average of all measurements was 27 pptv, whereas under polluted conditions the average was 7 pptv. Measureable quantities of dimethyl sulfide (>5 pptv) were not observed above the boundary layer. The average sulfur dioxide concentration measured in the marine (clean) atmosphere was 215 pptv, which is consistent with the oxidation of dimethyl sulfide being its major source.

Van Valin, C.C.; Luria, M.; Wellman, D.L.; Gunter, R.L.; Pueschel, R.F.

1987-06-01

3

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

SciTech Connect

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, A.R.; Thornton, D.C.; Driedger, A.R. III [Drexel Univ., Philadelphia, PA (United States)

1993-12-01

4

Monte Carlo predictions of phase equilibria and structure for dimethyl ether + sulfur dioxide and dimethyl ether + carbon dioxide  

NASA Astrophysics Data System (ADS)

A new force field for dimethyl ether (DME) based on the Lennard-Jones (LJ) 12-6 plus point charge functional form is presented in this work. This force field reproduces experimental saturated liquid and vapor densities, vapor pressures, heats of vaporization, and critical properties to within the statistical uncertainty of the combined experimental and simulation measurements for temperatures between the normal boiling and critical point. Critical parameters and normal boiling point are predicted to within 0.1% of experiment. This force field is used in grand canonical histogram reweighting Monte Carlo simulations to predict the pressure composition diagrams for the binary mixtures DME + SO2 at 363.15 K and DME + CO2 at 335.15 and 308.15 K. For the DME + SO2 mixture, simulation is able to qualitatively reproduce the minimum pressure azeotropy observed experimentally for this mixture, but quantitative errors exist, suggesting that multibody effects may be important in this system. For the DME + CO2 mixture, simulation is able to predict the pressure-composition behavior within 1% of experimental data. Simulations in the isobaric-isothermal ensemble are used to determine the microstructure of DME + SO2 and DME + CO2 mixtures. The DME + SO2 shows weak pairing between DME and SO2 molecules, while no specific pairing or aggregation is observed for mixtures of DME + CO2.

Kamath, Ganesh; Ketko, Marybeth; Baker, Gary A.; Potoff, Jeffrey J.

2012-01-01

5

Sulfur Dioxide and Material Damage  

ERIC Educational Resources Information Center

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

Gillette, Donald G.

1975-01-01

6

SULFUR DIOXIDE SOURCES IN AK  

EPA Science Inventory

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

7

Antibotulinal efficacy of sulfur dioxide in meat.  

PubMed Central

The addition of sodium metabisulfite as a source of sulfur dioxide delayed botulinal outgrowth in perishable canned comminuted pork when it was temperature abused at 27 degree C. The degree of inhibition was directly related to the level of sulfur dioxide. Levels greater than 100 microgram of sulfur dioxide per g were necessary to achieve significant inhibition when a target level of 100 botulinal spores per g was used. Sodium nitrite partially reduced the efficacy of the sulfur dioxide. Sulfur dioxide offers a new option for the control of botulinal outgrowth in cured or noncured meat and poultry products.

Tompkin, R B; Christiansen, L N; Shaparis, A B

1980-01-01

8

Theoretical and Experimental Studies of the Spin Trapping of Inorganic Radicals by 5,5-Dimethyl-1-Pyrroline N-Oxide (DMPO). 3. Sulfur Dioxide, Sulfite and Sulfate Radical Anions  

PubMed Central

Radical forms of sulfur dioxide (SO2), sulfite (SO32?), sulfate (SO42?), and their conjugate acids are known to be generated in vivo through various chemical and biochemical pathways. Oxides of sulfur are environmentally pervasive compounds and are associated with a number of health problems. There is growing evidence that their toxicity may be mediated by their radical forms. Electron paramagnetic resonance (EPR) spin trapping using the commonly used spin trap, 5,5-dimethyl-1-pyrroline N-oxide (DMPO), has been employed in the detection of SO3? and SO4?. The thermochemistries of SO2?, SO3?, SO4?, and their respective conjugate acids addition to DMPO were predicted using density functional theory (DFT) at the PCM/B3LYP/6-31+G**//B3LYP/6-31G* level. No spin adduct was observed for SO2? by EPR but an S-centered adduct was observed for SO3? and an O-centered adduct for SO4?. Determination of adducts as S- or O-centered was made via comparison based on qualitative trends of experimental hfccs with theoretically calculated ones. The thermodynamics of the non-radical addition of SO32? and HSO3? to DMPO followed by conversion to the corresponding radical adduct via the Forrester-Hepburn mechanism was also calculated. Adduct acidities and decomposition pathways were investigated as well, including an EPR experiment using H217O to determine the site of hydrolysis of O-centered adducts. The mode of radical addition to DMPO is predicted to be governed by several factors, including spin population density, and geometries stabilized by hydrogen bonds. The thermodynamic data supports evidence for the radical addition pathway over the nucleophilic addition mechanism.

Zamora, Pedro L.; Villamena, Frederick A.

2012-01-01

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

Analysis of atmospheric sulfur dioxide: a review  

Microsoft Academic Search

Commonly used manual and automatic methods for measurement and monitoring of sulfur dioxide in the atmosphere are critically reviewed. Promising but undeveloped techniques are discussed to stimulate interest in further development. 42 references.

Hochheiser

1967-01-01

11

21 CFR 582.3862 - Sulfur dioxide.  

Code of Federal Regulations, 2013 CFR

...3862 Section 582.3862 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT...RECOGNIZED AS SAFE Chemical Preservatives § 582.3862 Sulfur dioxide...that it is not used in meats or in food recognized as source of...

2013-04-01

12

Method for measuring gaseous sulfur dioxide  

Microsoft Academic Search

A method is described for measuring sulfur dioxide or sulfur trioxide in an oxygen-containing gas comprising: contacting the gas with a solid electrolyte comprising lithium sulfate and silver sulfate, the electrolyte being in electrical contact with a solid reference electrode comprising lithium sulfate, silver sulfate and silver in intimate admixture; and measuring the electrical potential between the electrolyte and the

Q. G. Liu; W. L. Worrell

1986-01-01

13

Nashville Sulfur Dioxide Emission Inventory and the Relationship of Emission to Measured Sulfur Dioxide  

Microsoft Academic Search

A detailed inventory of sulfur dioxide emissions was prepared as part of the Nashville Community Air Pollution Study conducted by the Public Health Service during 195859. The primary purpose of the inventory was to provide data for a study of the relationship between the emission of sulfur dioxide and measured ambient levels. The development of the inventory, data collection methods,

W. W. Stalker; P. A. Kenline; H. J. Paulus

1964-01-01

14

Taxing sulfur dioxide emission allowances  

SciTech Connect

The acid rain control program authorized by Title IV of the Clean Air Act Amendments of 1990 (CAAA) was designed to reduce the adverse effects of acid rain by limiting emissions of sulfur dioxide (SO[sub 2]) into the atmosphere. The program is a complex scheme involving the issuance, consumption, holding, and trading of emission allowances for SO[sub 2]. Not surprisingly, electric utilities will face federal income tax issues in connection with the program. Under the emission allowance program, the U.S. Environmental Protection Agency (EPA) will issue emission allowance to owners or operators of certain utility power plants at no cost to the recipients. An emission allowance is an authorization to emit one ton of SO[sub 2] during or after the calendar year for which it is issued. If a utility power plant subject to the program emits SO[sub 2] in excess of its allowances, the owner or operator will be subject to a penalty of $2,000 a ton, and must offset the excess emissions with allowances in the subsequent year. Allowances may be bought and sold. Phase I of the program begins January 1, 1995, and will apply to 110 utility generating units. Phase II takes effect January 1, 2000, and will include most electric utility generating units. EPA will withhold a specified number of allowances for direct sale and auction. The resulting proceeds will be paid to the utilities from which the allowances were withheld. The Internal Revenue Service (IRS) has provided somewhat limited guidance on several tax issues raised by the program. Significant tax issues and the positions articulated by the IRS (if any) are discussed in this article.

Nelson, G.L. (Reid Priest, Washington, DC (United States))

1993-09-15

15

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

16

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

Code of Federal Regulations, 2013 CFR

... false National primary ambient air quality standards for sulfur oxides (sulfur dioxide...NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS § 50.4 National primary ambient air quality standards for sulfur oxides (sulfur...

2013-07-01

17

An intercomparison of aircraft instrumentation for tropospheric measurements of sulfur dioxide  

Microsoft Academic Search

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,

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

1993-01-01

18

An intercomparison of aircraft instrumentation for tropospheric measurements of sulfur dioxide  

Microsoft Academic Search

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

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

1993-01-01

19

Sulfur Dioxide Contributions to the Atmosphere by Volcanoes  

Microsoft Academic Search

The first extensive measurements by remote-sensing correlation spectrometry of the sulfur dioxide emitted by volcanic plumes indicate that on the order of 10 3 metric tons of sulfur dioxide gas enter the atmosphere daily from Central American volcanoes. Extrapolation gives a minimum estimate of the annual amount of sulfur dioxide emitted from the world's volcanoes of about 107 metric tons.

Richard E. Stoiber; Anders Jepsen

1973-01-01

20

Effect of sulfur dioxide on wheat development  

Microsoft Academic Search

This investigation was undertaken to determine whether growing plants are injured when exposed over long periods to concentrations of sulfur dioxide which are insufficient to produce typical foliar markings. If, as has been claimed, concentrations of this gas in the air, near yet below the threshold of visible injury, are actually injurious to plant growth, the question at once broadens

R. E. Swain; A. B. Johnson

1936-01-01

21

Sulfur dioxide absorption at DF laser wavelengths  

Microsoft Academic Search

The absorption of DF laser lines by sulfur dioxide under atmospheric conditions is measured in light of the possible application of optical methods to the detection of the atmospheric pollutant. Absorption measurements were performed for 20 DF laser wavelengths between 2792 and 2509 kaysers in a multipass absorption cell. Weak absorption is detected around a wavelength of 3.7 microns and

J. Altmann; P. Pokrowsky

1980-01-01

22

Io: longitudinal distribution of sulfur dioxide frost.  

PubMed

Twenty spectra of Io (0.26 to 0.33 micrometer), acquired with the International Ultraviolet Explorer spacecraft, have been studied. There is a strong ultraviolet absorption shortward of 0.33 micrometer that is consistent with earlier ground-based spectrophotometry; its strength is strongly dependent on Io's rotational phase angle at the time of observation. This spectral feature and its variation are interpreted as indicative of a longitudinal variation in the distribution of sulfur dioxide frost on Io. The frost is most abundant at orbital longitudes 72 degrees to 137 degrees and least abundant at longitudes 250 degrees to 323 degrees . Variations in spectral reflectivity between 0.4 and 0.5 micrometer, reported in earlier ground-based spectral studies, correlate inversely with variations in reflectivity between 0.26 and 0.33 micrometer. It is concluded that this is because the Io surface component with the highest visible reflectivity (sulfur dioxide frost) has the lowest ultraviolet reflectivity. At least one other component is present and may be sulfur allotropes or alkali sulfides. This model is consistent with ground-based ultraviolet, visible, and infrared spectrophotometry. Comparison with Voyager color photographs indicates that the sulfur dioxide frost is in greatest concentration in the "white" areas on Io and the other sulfurous components are in greatest concentration in the "red" areas. PMID:17739547

1980-11-14

23

40 CFR 60.333 - Standard for sulfur dioxide.  

Code of Federal Regulations, 2013 CFR

...Standards of Performance for Stationary Gas Turbines § 60.333 Standard for sulfur dioxide...the atmosphere from any stationary gas turbine any gases which contain sulfur dioxide...subpart shall burn in any stationary gas turbine any fuel which contains total sulfur...

2013-07-01

24

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

25

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

26

Using broadband absorption spectroscopy to measure concentration of sulfur dioxide  

Microsoft Academic Search

A linear relationship between concentration of sulfur dioxide (SO2) and optical parameter (OP) is established using the Beer-Lambert law. The SO2 measuring system is set up to measure the concentration of sulfur dioxide in the wavelength range 275-315 nm. Experimental results indicate that the detection limit of the sulfur dioxide measuring system is below 0.2 ppm per meter of path

H. S. Wang; Y. G. Zhang; S. H. Wu; X. T. Lou; Z. G. Zhang; Y. K. Qin

2010-01-01

27

Using broadband absorption spectroscopy to measure concentration of sulfur dioxide  

Microsoft Academic Search

A linear relationship between concentration of sulfur dioxide (SO2) and optical parameter (OP) is established using the BeerLambert law. The SO2 measuring system is set up to measure the concentration of sulfur dioxide in the wavelength range 275315nm. Experimental\\u000a results indicate that the detection limit of the sulfur dioxide measuring system is below 0.2ppm per meter of path length,\\u000a and

H. S. Wang; Y. G. Zhang; S. H. Wu; X. T. Lou; Z. G. Zhang; Y. K. Qin

2010-01-01

28

Modeling sulfur dioxide absorption by fine water spray  

SciTech Connect

A novel theoretical model was developed to determine the removal efficiency of sulfur dioxide using fine water spray. The droplet pH, diameter, S(IV) concentration, sulfur dioxide concentration, and liquid-to-gas ratio are found to influence the absorption of sulfur dioxide by the fine water spray. The results demonstrate that the absorption of sulfur dioxide by the fine water spray increases as the droplet diameter falls. The concentration gradient between the interface of the gaseous and liquid phases causes the absorption of sulfur dioxide by the droplets to increase as the initial S(IV) concentration decreases or the sulfur dioxide concentration increases. The results indicate that the performance of the fine water spray in removing sulfur dioxide is generally improved by reducing the droplet diameter or the initial S(IV) concentration, or by increasing the sulfur dioxide concentration, the droplet pH or the liquid-to-gas ratio. The proposed model reveals the parameters that should be controlled in using a fine water spray device and a method for improving its performance in removing sulfur dioxide.

Cheng-Hsiung Huang [Yuanpei University of Science and Technology, Hsin Chu (Taiwan)

2005-07-01

29

Sulfur dioxide removal from gas streams  

SciTech Connect

A process is described for removal of sulfur dioxide pollutant gas from gas stream which comprises contacting the gas stream with pretreated shale in the form of an aqueous solution of aluminum sulfate including from about 0.1 to about 2.0% by weight of the pretreated shale. The pretreatment of the shale comprises the heating of the shale in the presence of a gas unable to support combustion at a temperature in a range of from about 340/sup 0/C. to about 480/sup 0/C.

Urban, P.; Ginger, E.A.

1986-11-11

30

Kinetics of decomposition of manganese slimes by sulfur dioxide  

SciTech Connect

Lean manganese ores, and slimes obtained during mechanical beneficiation of Chiatura manganese ores, have been treated by the sulfite process, by saturation of suspensions with sulfur dioxide. The kinetics of saturation of the suspensions with sulfur dioxide, and transfer of manganese into solution was studied. Manganese was leached out by passing sulfur dioxide through the slime suspension. The sulfur dioxide dissolved in water to form the weakly dissociated sulfurous acid in equilibrium with its anhydrides. The leaching was conducted without access of air at room temperature. An equation for determination of the rate of sulfur dioxide adsorption by a manganese-containing slurry and for calculation of the degree of manganese extraction into solution was developed from the experimental results. The reaction order and the control regime of the processes were determined.

Dzhaparidze, P.I.; Kelbakiani, N.V.

1982-02-20

31

Effects of sulfur dioxide on the aquatic plant Elodea  

Microsoft Academic Search

The effects of sulfur dioxide upon the green plant cell was investigated with emphasis on the effects of the gas on Elodea canadensis. Toxicity studies were performed in which the relations between concentration of sulfur dioxide, pH of the solution, and duration of exposure were investigated. Changes in the structures of the cell induced by lethal and sub-lethal concentrations of

Brooks

1943-01-01

32

Sulfur Dioxide Emission Projections for Maryland Utilities 2000-2030.  

National Technical Information Service (NTIS)

The purpose of the report is to project sulfur dioxide emissions from Maryland electric utilities for the years 2000-2030. Sulfur dioxide emissions data for 1980-1985 and projections from Maryland utilities through 2000, were obtained from state agencies ...

1987-01-01

33

Sulfur Dioxide Adsorption and Desorption on Various Filter Media  

Microsoft Academic Search

Atmospheric sampling for gaseous pollutants in many cases requires removal of suspended particulates preceding the gas sampler. A series of experiments was performed to determine the extent to which sulfur dioxide was adsorbed on the various material of filter holders and filters. Atmospheric concentrations of sulfur dioxide (0.05 and 0.10 ppm) were passed through plastic, aluminum, stainless steel, and Teflon

R. Lee Byers; John W. Davis

1970-01-01

34

Direct extraction of sulfur dioxide from sulfates for isotopic analysis  

Microsoft Academic Search

A convenient method of extraction of sulfur dioxide from natural sulfates (BaSO, SrSO, and CaSO) for sulfur isotopic analysis is described. A sulfate is reacted with NaPO under vacuum at 850°C; SO thus obtained is then reduced to sulfur dioxide on copper heated to 750°C. It has been experimentally shown that the reaction takes place with complete yield and provides

Stanislaw. Halas; Wojeiech P. Wolacewicz

1981-01-01

35

Corrosion of manganese in sulfur dioxide at high temperatures  

Microsoft Academic Search

The reaction of manganese with sulfur dioxide at 0.1 MPa at 9731173 K was studied. The composition and morphology of the scales were investigated by scanning electron microscopy (SEM) and various of X-ray analysis techniques. Transport phenomena occurring in the growing scales were studied by means of radiotracer techniques using sulfur dioxide labeled with the radioactive isotope of sulfur, 35S.

J. Gilewicz-Wolter; Z. ?urek; J. Duda?a

2004-01-01

36

Electrooxidation of sulfur dioxide on some carbonaceous materials  

Microsoft Academic Search

The anodic oxidation of sulfur dioxide presents much interest in connection with the electrochemical manufacture of sulfuric acid and also with the problem of converting thermal energy into hydrogen chemical energy in a so-called thermoelectrochemical sulfuric acid cycle. The problem of this work was to ascertain the effect of some physicochemical properties of carbonaceous materials on their electrocatalytic properties in

N. A. Urisson; G. V. Shteinberg; A. V. Yuzhanina; V. G. Morozov

1987-01-01

37

Terpolymerization of ethylene, sulfur dioxide and carbon monoxide  

DOEpatents

This invention relates to a high molecular weight terpolymer of ethylene, sulfur dioxide and carbon monoxide stable to 280.degree. C. and containing as little as 36 mol % ethylene and about 41-51 mol % sulfur dioxide; and to the method of producing said terpolymer by irradiation of a liquid and gaseous mixture of ethylene, sulfur dioxide and carbon monoxide by means of Co-60 gamma rays or an electron beam, at a temperature of about 10.degree.-50.degree. C., and at a pressure of about 140 to 680 atmospheres, to initiate polymerization.

Johnson, Richard (Shirley, NY); Steinberg, Meyer (Huntington Station, NY)

1981-01-01

38

Asthma, sulfur dioxide, and the Clean Air Act  

SciTech Connect

Laboratory findings on the effects of sulfur dioxide in patients with asthma are related to theories about the mechanisms of bronchial hyperreactivity, an abnormality that may be fundamental to the pathogenesis of asthma and then to questions of national policy on air quality. Work has shown that people with asthma are abnormally sensitive to inhalation of sulfur dioxide and that bronchospasm may develop if they pursue activities that require light exercise while breathing air containing a level of sulfur dioxide permitted by current ambient air-quality standards. The provisions of the Clean Air Act of 1970 require that sensitive groups in the population be protected against adverse health effects, and our data therefore indicate the need for a short-term standard for sulfur dioxide.

Boushey, H.

1982-02-01

39

Methods of Measuring and Monitoring Atmospheric Sulfur Dioxide.  

National Technical Information Service (NTIS)

A literature review of methodology relating to the measurement of atmospheric sulfur dioxide, a detailed description of recommended methods, and criteria for selection of recommended methods are presented in this report. This publication is intended to se...

S. Hochheiser

1964-01-01

40

DYNAMIC DILUTION SYSTEM FOR AUDITING AMBIENT SULFUR DIOXIDE ANALYZERS  

EPA Science Inventory

This paper discusses the development, evaluation, and field performance of a device designed to provide accurate sulfur dioxide concentration standards suitable for auditing the accuracy of continuous, ambient SO2 monitors. This compact, lightweight, device has been subjected to ...

41

Sulfur dioxide absorption at DF laser wavelengths  

NASA Astrophysics Data System (ADS)

The absorption of DF laser lines by sulfur dioxide under atmospheric conditions is measured in light of the possible application of optical methods to the detection of the atmospheric pollutant. Absorption measurements were performed for 20 DF laser wavelengths between 2792 and 2509 kaysers in a multipass absorption cell. Weak absorption is detected around a wavelength of 3.7 microns and is attributed to the 2 nu 3 band of SO2. The P 4(6) line at 3.9843 microns is found to be strongly absorbed by the (nu 1 + nu 3) band of SO2, with a specific absorption coefficient of 0.44 + or - 0.01/cm per atm, which indicates that strong SO2 emissions in the atmosphere can be detected optically. Measurements of the pressure dependence of the absorption coefficient of the P4(6) line reveal broadening coefficients between 1.5 and 5 MHz/Torr, depending on line strength, and a wavenumber difference of 0.0043 + or - 0.0004 kaysers from the P4(6) DF line to the center of the nearest SO2 line.

Altmann, J.; Pokrowsky, P.

1980-10-01

42

Sensing Free Sulfur Dioxide in Wine  

PubMed Central

Sulfur dioxide (SO2) is important in the winemaking process as it aids in preventing microbial growth and the oxidation of wine. These processes and others consume the SO2 over time, resulting in wines with little SO2 protection. Furthermore, SO2 and sulfiting agents are known to be allergens to many individuals and for that reason their levels need to be monitored and regulated in final wine products. Many of the current techniques for monitoring SO2 in wine require the SO2 to be separated from the wine prior to analysis. This investigation demonstrates a technique capable of measuring free sulfite concentrations in low volume liquid samples in white wine. This approach adapts a known colorimetric reaction to a suspended core optical fiber sensing platform, and exploits the interaction between guided light located within the fiber voids and a mixture of the wine sample and a colorimetric analyte. We have shown that this technique enables measurements to be made without dilution of the wine samples, thus paving the way towards real time in situ wine monitoring.

Monro, Tanya M.; Moore, Rachel L.; Nguyen, Mai-Chi; Ebendorff-Heidepriem, Heike; Skouroumounis, George K.; Elsey, Gordon M.; Taylor, Dennis K.

2012-01-01

43

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

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.

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

1976-01-01

45

40 CFR 60.46c - Emission monitoring for sulfur dioxide.  

Code of Federal Regulations, 2013 CFR

...Emission monitoring for sulfur dioxide. 60.46c Section...Emission monitoring for sulfur dioxide. (a) Except...and operate a CEMS for measuring SO2 concentrations...emission rate by using Method 6B of appendix A...

2013-07-01

46

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

Federal Register 2010, 2011, 2012, 2013

...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

47

21 CFR 182.3862 - Sulfur dioxide.  

Code of Federal Regulations, 2013 CFR

...3862 Section 182.3862 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT...HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED...RECOGNIZED AS SAFE Chemical Preservatives § 182.3862 Sulfur...

2013-04-01

48

Low Energy, Low Emissions: Sulfur Dioxide; Nitrogen Oxides, and Carbon Dioxide in Western Europe.  

ERIC Educational Resources Information Center

|Links proposed low-energy scenarios for different Western European countries with the amount of pollutants that may result from these scenarios. Sulfur dioxide, nitrogen oxide, and carbon dioxide emissions are calculated for the 10 countries for which low-energy scenarios are available, resulting in reductions of 54%, 37%, and 40%, respectively.

Alcamo, Joseph; De Vries, Bert

1992-01-01

49

Carbon dioxide tolerance in the single-stage liquid-phase synthesis of dimethyl ether  

SciTech Connect

In the liquid-phase dimethyl ether process, methanol synthesis catalyst (Cu/ZnO/Al{sub 2}O{sub 3}) and methanol dehydration catalyst ({gamma}-alumina) are slurred in an inert liquid medium. The inert liquid medium used in this investigation is a white mineral oil, Witco-40. This multiphase reaction is conducted in a mechanically agitated slurry reactor. In this process, syngas conversion can be significantly improved by coproduction of dimethyl ether along with methanol. The coproduction strategy improves the thermodynamic and kinetic environment of the reaction system. The effects of catalyst loadings in the slurry and the roles played by carbon dioxide in dimethyl ether synthesis were studied by conducting kinetic experiments. The liquid-phase dimethyl ether synthesis process exhibits higher carbon dioxide tolerance as compared to the liquid-phase methanol synthesis process, whose optimal carbon dioxide concentration in the unbalanced syngas feed is around 8%. These results have been experimentally confirmed.

Sardesai, A.; Gunda, A.; Tartamella, T.; Lee, S.

2000-01-01

50

An in Situ Infrared Study of Dimethyl Carbonate Synthesis from Carbon Dioxide and Methanol over Zirconia  

Microsoft Academic Search

The mechanism of dimethyl carbonate (DMC) synthesis from methanol and carbon dioxide over monoclinic zirconia has been investigated using in situ infrared spectroscopy. The dissociative adsorption of methanol occurs more slowly than the adsorption of carbon dioxide, but the species formed from methanol are bound more strongly. On adsorption, the oxygen atom of methanol binds to coordinately unsaturated Zr4+ cations

Kyeong Taek Jung; Alexis T. Bell

2001-01-01

51

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

Microsoft Academic Search

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

James E. Johnson; Timotny S. Bates

1993-01-01

52

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

53

Sulfur Dioxide Measurements Near Point Sources Using Ultraviolet Spectroscopy From Aircraft During ICARTT-2004  

Microsoft Academic Search

Accurate measurements of sulfur dioxide are important in urban air pollution studies due to the role sulfur dioxide plays in atmospheric processes such as acid rain and particle formation. We will show slant column sulfur dioxide abundances that were derived using the differential optical absorption spectroscopy (DOAS) technique with ultraviolet spectrograph measurements taken aboard the NOAA WP-3D aircraft during ICARTT-2004.

M. L. Melamed; A. O. Langford; J. S. Daniel; H. L. Miller; R. W. Portmann; R. Schofield; S. Solomon

2005-01-01

54

An ecological survey of the effect of sulfur dioxide emitted from an Acid Work Factory  

Microsoft Academic Search

Sulfur dioxide is che of the most common air pollutants. The acid manufacturing factory ai Ching Lung Tau, Hong Kong has emitted large quantities of sulfur dioxide into the atmosphere since 1955. Sulfur dioxide emitted from the factory moved according to the prevailing wind and dam~ged the surrounding vegetation. Erosion of the top soil followed the death of plants and

Ming-Hung Wong

1978-01-01

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

A sensitive method for measuring atmospheric concentrations of sulfur dioxide  

Microsoft Academic Search

A new sensitive method for measuring atmospheric concentrations of sulfur dioxide is presented. Samples are obtained using the mist chamber, which collects highly water-soluble gases with high efficiency, and concentrates them in a small volume of water. Particles are removed from the sampled air stream with a teflon filter, before it enters the mist chamber. After collection, the pH of

O. Klemm; R. W. Talbot

1991-01-01

57

The vertical sulfur dioxide distribution at the tropopause level  

Microsoft Academic Search

In 19781980 nine aircraft flights to an altitude of up to 15 km were made over western Europe. Sulfur dioxide was measured with a sensitive chemiluminescence method consisting of separate sampling and analysis stages and application of a wet chemical filter procedure (detection limit: 8 pptv SO2).

F. X. Meixner; F. R. Germany

1984-01-01

58

Sulfur dioxide inhibition of photosynthesis in isolated spinach chloroplasts  

Microsoft Academic Search

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

J. E. Silvius; M. Ingle; C. H. Baer

1975-01-01

59

SUSCEPTIBILITY OF WOODY PLANTS TO SULFUR DIOXIDE AND PHOTOCHEMICAL OXIDANTS  

EPA Science Inventory

This report presents the result of a detailed review of European and United States literature regarding the sensitivity of woody vegetation to sulfur dioxide, ozone, peroxyacetyl nitrate (PAN), or nitrogen oxides. Reference is made to Russian, Japanese and Austrian literature onl...

60

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...

61

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...

62

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

63

Synthesis of dimethyl carbonate from carbon dioxide: catalysis and mechanism  

Microsoft Academic Search

The turnover number of the catalytic production of dimethyl carbonate from CO2 and methanol is restricted by thermodynamics as well as catalyst decomposition. The catalytic efficiency is remarkably improved using an acetal as the starting material in methanol. The catalytic activity and selectivity also depend strongly on the CO2 pressure. A possible catalytic cycle involving transformation of CO2 to dimethyl

Toshiyasu Sakakura; Jun-Chul Choi; Yuko Saito; Takeshi Sako

2000-01-01

64

Infrared Spectra of Liquid Anhydrous Hydrogen Fluoride, Liquid Sulfur Dioxide and Hydrogen Fluoride-Sulfur Dioxide Solutions  

Microsoft Academic Search

The infrared spectra of anhydrous liquid hydrogen fluoride, anhydrous liquid sulfur dioxide and mixtures of the two have been measured in the region from 1? to 25?. A value for the extinction coefficient for the polymer peak in the region higher than previously reported has been found, reflecting the existence of a greater proportion of higher hydrogen fluoride polymers in

Robert H. Maybury; Sheffield Gordon; Joseph J. Katz

1955-01-01

65

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.

Kettner, Helmut

1965-01-01

66

Sulfur Dioxide and Nitrogen Dioxide Adsorption on Zinc Oxide and Zirconium Hydroxide Nanoparticles and the Effect on Photoluminescence.  

National Technical Information Service (NTIS)

Nanoparticulate zinc oxide and micron-size zirconium hydroxide powders have been exposed to sulfur dioxide and nitrogen dioxide by flowing the gases, diluted with nitrogen, over powder samples. X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, a...

A. Mukherjee G. W. Peterson J. Im J. Singh J. E. Whitten

2012-01-01

67

Catalytic oxidation of sulfur dioxide by heterogeneous cobalt-phthalocyanine  

SciTech Connect

Various homogeneous and hybrid cobalt phthalocyanines were developed. They were shown to be effective catalysts for the catalytic degradation of many aqueous pollutants. The catalytic activity of these systems was attributed to their ability to activate molecular oxygen. Semiconductor titanium dioxide was found to be useful both as solid support and photocatalyst. The electron relay property of cobalt phthalocyanine on the photoactive TiO/sub 2/ surface was elucidated. The homogeneous and heterogeneous kinetics and mechanisms for the catalytic oxidation of aqueous sulfur dioxide were studied.

Hong, P.K.A.

1988-01-01

68

Spatial Variability of Ambient Nitrogen Dioxide and Sulfur Dioxide in Sarnia, Chemical Valley, Ontario, Canada  

Microsoft Academic Search

This study aimed at developing models to predict nitrogen dioxide (NO2) and sulfur dioxide (SO2) concentrations in Sarnia, Chemical Valley, Ontario, Canada, and model the intra-urban variation of ambient NO2 and SO2 in the city for a community health study. NO2 and SO2 samples were monitored with Ogawa passive samplers at 39 locations across the city for 2 wk during

Dominic O. Atari; Isaac Luginaah; Xiaohong Xu; Karen Fung

2008-01-01

69

Comparison of Several Methods for Nitrogen Dioxide and Sulfur Dioxide in Metro Manila Air  

Microsoft Academic Search

The pollutant gases nitrogen dioxide (NO2) and sulfur dioxide (SO2) are two of the commonly monitored parameters for air quality assessment in the Philippines. In this study, several active and passive sampling methods for the analysis of the two gases were tested. Of the methods for NO2 first tested indoors, the NaI sorbent passive sampling method was found most promising

Leni L. Quirit; Karen N. Hernandez; Brian J. Lee

70

Simultaneous Sulfur Dioxide and Nitrogen Dioxide Removal by Calcium Hydroxide and Calcium Silicate Solids  

Microsoft Academic Search

At conditions typical of a bag filter exposed to a coal-fired flue gas that has been adiabatically cooled with water, calcium hydroxide and calcium silicate solids were exposed to a dilute, humidified gas stream of nitrogen dioxide (NO2) and sulfur dioxide (SO2) in a packed-bed reactor. A prior study found that NO2 reacted readily with surface water of alkaline and

Christopher H. Nelli; Gary T. Rochelle

1998-01-01

71

High-Capacity Sulfur Dioxide Absorbents for Diesel Emissions Control  

Microsoft Academic Search

High capacity sulfur dioxide absorbents based on manganese oxide octahedral molecular sieves (OMS) have been identified. These materials are based on MnO6 octahedra sharing faces and edges to form various tunnel structures (2x2, 2x3, 2x4, 3x3) differentiated by the number of octahedra on a side. The SO2 capacities of these materials, measured at 325 C with a feed containing 250

Liyu Li; David L. King

2005-01-01

72

The abundance of sulfur dioxide below the clouds of Venus  

Microsoft Academic Search

We present a new method for determining the abundance of sulfur dioxide below the clouds of Venus. Absorption by the 3nu3 band of SO2 near 2.45 microns has been detected in high-resolution spectra of the night side of Venus recorded at the Canada-France Hawaii telescope in 1989 and 1991. The inferred SO2 abundance is 130 +\\/- 40 ppm at all

Bruno Bezard; Catherine de Bergh; Bruce Fegley; Jean-Pierre Maillard; David Crisp; Tobias Owen; James B. Pollack; David Grinspoon

1993-01-01

73

Particulate Matter, Sulfur Dioxide, and Daily Mortality in Chongqing, China  

Microsoft Academic Search

In 1995, daily mortality in a district of Chongqing, China, was analyzed from January through December for associations with daily ambient sulfur dioxide and fine particles (airborne particles with diameters ? 2.5 m; PM2.5). The mean concentration of PM2.5 was 147 g\\/m3 (maximum, 666 g\\/m3), and that of SO2 was 213 g\\/m3 (maximum, 571 g\\/m3). On average, 9.6 persons died

Scott A. Venners; Binyan Wang; Zhonggui Peng; Yu Xu; Lihua Wang; Xiping Xu

2002-01-01

74

An intercomparison of aircraft instrumentation for tropospheric measurements of sulfur dioxide  

SciTech Connect

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, G.L.; Davis, D.D.; Beltz, N.; Bandy, A.R.; Ferek, R.J.; Thornton, D.C. [NASA, Langely Research Center, Hampton, VA (United States)]|[Georgia Institute of Technology, Atlanta, GA (United States)]|[J.W. Goethe Univ., Frankfurt (Germany)]|[Drexel Univ., Philadelphia, PA (United States)]|[Univ. of Washington, Seattle, WA (United States)

1993-12-01

75

Determination of sulfur dioxide in stack gases by ultraviolet absorption spectrometry  

Microsoft Academic Search

Sulfur dioxide was collected and concentrated by bubbling stack gases through a buffered solution of sodium tetrachloromercurate. Treatment with sulfamic acid eliminated interference by nitrogen dioxide. The tetrachloromercurate samples were injected into a reaction vessel containing 15 ml of 1.8 M HSO to evolve sulfur dioxide. Design of the reaction vessel is discussed. The SO was carried by a nitrogen

H. Eugene Winkler; Augusta Syty

1976-01-01

76

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

77

Sulfur dioxide emissions from la soufriere volcano, st. Vincent, west indies.  

PubMed

During the steady-state period of activity of La Soufriere Volcano in 1979, the mass emissions of sulfur dioxide into the troposphere amounted to a mean value of 339 +/- 126 metric tons per day. This value is similar to the sulfur dioxide emissions of other Central American volcanoes but less than those measured at Mount Etna, an exceptionally strong volcanic source of sulfur dioxide. PMID:17810988

Hoff, R M; Gallant, A J

1980-08-22

78

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

Microsoft Academic Search

With the rapid development of the economy, the sulfur dioxide (SO) emission from China since 2000 is of increasing concern. In this study, we estimate the annual SO emission in China after 2000 using a technology-based methodology specifically for China. From 2000 to 2006, total SO emission in China increased by 53%, from 21.7 Tg to 33.2 Tg, at an

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

2010-01-01

79

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

Microsoft Academic Search

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

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

2010-01-01

80

Effect of the electrode material on the mechanism of anodic oxidation of sulfur dioxide  

Microsoft Academic Search

The adsorption and oxidation of sulfur dioxide on platinized platinum (Pt-Pt) and cobalt dibenzotetraazaannulene (CoTAA) were measured a pH 03 to 12.9 by the labeled atom method and voltametry. Sulfur dioxide was obtained by the addition of the necessary amount of solution of 0.1 M sodium sulfite (labeled with sulfur 35) to the supporting electrolyte. Strong chemisorption of sulfur-containing species

V. E. Kazarinov; K. A. Radyushkina; M. R. Tarasevich; O. A. Levina; V. N. Andreev

1982-01-01

81

Advanced Byproduct Recovery: Direct Catalytic Reduction of Sulfur Dioxide to Elemental Sulfur.  

SciTech Connect

More than 170 wet scrubber systems applied, to 72,000 MW of U.S., coal-fired, utility boilers are in operation or under construction. In these systems, the sulfur dioxide removed from 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). Due to the abundance and low cost of naturally occurring gypsum, and the costs associated with producing an industrial quality product, less than 7% of these scrubbers are configured to produce usable gypsum (and only 1% of all units actually sell the byproduct). The disposal of solid waste from each of these scrubbers requires a landfill area of approximately 200 to 400 acres. In the U.S., a total of 19 million tons of disposable FGD byproduct are produced, transported and disposed of in landfills annually. The use of regenerable sorbent technologies has the potential to reduce or eliminate solid waste production, transportation and disposal. In a regenerable sorbent system, the sulfur dioxide in the boiler flue gas is removed by the sorbent in an adsorber. The S0{sub 2}s subsequently released, in higher concentration, in a regenerator. All regenerable systems produce an off-gas stream from the regenerator that must be processed further in order to obtain a salable byproduct, such as elemental sulfur, sulfuric acid or liquid S0{sub 2}.

NONE

1997-06-01

82

Genotoxic effects of sulfur dioxide in human lymphocytes.  

PubMed

Sulfur dioxide (SO(2)), which is used as food preservative in apricot sulfurization and several fabricated foods, is a common air pollutant. The aim of this study was to reveal the possible genotoxic effects of SO(2) using in vitro human lymphocytes. The different endpoints of genotoxicity: sister chromatid exchange (SCE), micronuclei (MN) tests and cell growth kinetics such as mitotic index (MI) and replication index (RI) were studied. The cells were treated with 0.1, 0.5 and 1.0 ppm concentrations of SO(2). It was shown that SO(2) caused significant increases in the frequency of SCE and MN in the middle and high dosage groups and also induced mitotic delays and decreased MI and RI. In conclusion, the results have confirmed that SO(2) has potent mutagenicity and it can cause genetic damage leading to a malignancy. PMID:22903179

Uren, Nihal; Yuksel, Sengul; Onal, Yunus

2012-08-17

83

The rotational spectrum of protonated sulfur dioxide, HOSO+  

NASA Astrophysics Data System (ADS)

Aims: We report on the millimeter-wave rotational spectrum of protonated sulfur dioxide, HOSO+. Methods: Ten rotational transitions between 186 and 347 GHz have been measured to high accuracy in a negative glow discharge. Results: The present measurements improve the accuracy of the previously reported centimeter-wave spectrum by two orders of magnitude, allowing a frequency calculation of the principal transitions to about 4 km s-1 in equivalent radial velocity near 650 GHz, or one linewidth in hot cores and corinos. Conclusions: Owing to the high abundance of sulfur-bearing molecules in many galactic molecular sources, the HOSO+ ion is an excellent candidate for detection, especially in hot cores and corinos in which SO2 and several positive ions are prominent.

Lattanzi, V.; Gottlieb, C. A.; Thaddeus, P.; Thorwirth, S.; McCarthy, M. C.

2011-09-01

84

Lignosulfonate-modified calcium hydroxide for sulfur dioxide control  

SciTech Connect

This article discusses the use of lignosulfonate-modified calcium hydroxide Ca(OH)/sub 2/ for sulfur dioxide (SO/sub 2/) 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 of sulfur and nitrogen from coal-burning utility boilers. The most effective commercial calcium-based sorbent for this process is Ca(OH)/sub 2/, with SO/sub 2/ removals of about 50%. Additions of calcium lignosulfonate up to 1.5 mass % of the dry product, introduced with the water of hydration, increase the SO/sub 2/ capture of the resulting Ca(OH)/sub 2/ to 60%. This is achieved through particle-size reduction in the modified hydroxides. The principal mechanism of size reduction appears to be deagglomeration of the Ca(OH)/sub 2/ crystals; a secondary benefit is derived from crystal size reduction.

Kirchgessner, D.A.; Lorrain, J.M.

1987-01-01

85

Effects of acid rain and sulfur dioxide on marble dissolution  

SciTech Connect

Acid precipitation and the dry deposition of sulfur dioxide (SO[sub 2]) 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 SO[sub 2] 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, P.F.; Reddy, M.M. (Geological Survey, Boulder, CO (United States)); Sherwood, S.I. (National Park Service, Washington, DC (United States))

1994-01-01

86

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

87

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

88

Detection of sulfur dioxide using a piezoelectric quartz crystal microbalance  

SciTech Connect

Sulfur dioxide was detected and determined in air by a piezoelectric quartz crystal sensor coated with 4-aminoantipyrine/1-hydroxyetil-2-heptadecenyl imidazol (amine 220) solution (1:1 v/v in chloroform). The analytical response curve is linear over the concentration range from 0.70 to 5.0 ppm of SO{sub 2}. Good linearities (r = 0.9990, 0.9995 and 0.9968) and sensitivities (18.0, 33.4 and 50.7 Hz/ppm) were found, respectively for exposure times of 30, 60 and 90 seconds. The sensor can be used for more than six months without loss in sensitivity and presented good reversibility and reproducibility. Among some possible interferents tested, only nitrogen dioxide and moisture caused major frequency changes.

Guimaraes, O.M. [Instituto de Quimica de Sao Carlos (Brazil)

1997-09-01

89

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 products with sulfur dioxide; fatty acids, tall-oil, reaction products with 1-piperazineethanamine...sulfur dioxide; fatty acids, tall-oil reaction products with sulfur dioxide and...

2009-07-01

90

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 products with sulfur dioxide; fatty acids, tall-oil, reaction products with 1-piperazineethanamine...sulfur dioxide; fatty acids, tall-oil reaction products with sulfur dioxide and...

2010-07-01

91

Microwave induced reactions of sulfur dioxide and nitrogen oxides in char and anthracite bed  

Microsoft Academic Search

Microwaves applied to a pyrolytic carbon matrix enhance the chemical reactions of nitric oxide (NO) and sulfur dioxide (SO2) with carbon to produce nitrogen, sulfur, and carbon dioxide. These microwave-induced reactions were investigated to find the feasibility of applying microwaves to directly destroy NO and SO2 in the combustion product gases or to minimize the formation of these pollutants during

Chang Yul Cha; Dong Sik Kim

2001-01-01

92

Study on time divided double optical paths ultraviolet fluorescence for concentration measuring of sulfur dioxide  

Microsoft Academic Search

The research on the detection of sulfur dioxide concentration in flue-gas is a hot topic all the time. Based on the analysis of the measuring principles for the sulfur dioxide concentration using ultraviolet fluorescence method, one new measuring method using time-divided double optical paths is proposed. This method overcomes the problems of cross sensitivity and background noise in single path

Shanpo Nian; Caixia Hou; Lei Chen; Ruikun Gong; Guangxiang Zhang; Yansong Tian

2010-01-01

93

Comparison of Enhanced and Routine Methods for Measuring Ambient Low-level Sulfur Dioxide  

Microsoft Academic Search

The work reported here was designed to determine: (1) the adequacy of a conventional monitoring method for measuring low-level (<20 ppbv) ambient sulfur dioxide; and (2) the measurement improvement obtained with an enhanced monitoring method. Two analyses were used. In the first analysis, two different continuous monitoring methods were evaluated against an independent measure of ambient sulfur dioxide concentration-an integrated

Lawrence M. Reisinger; Kenneth J. Olszyna; Teresa L. Hetrick

1989-01-01

94

The sampling of sulfur dioxide in air with impregnated filter paper  

Microsoft Academic Search

A method is suggested for the sampling of sulfur dioxide in air with impregnated filter paper instead of bubblers. The best aqueous impregnating solution contained potassium hydroxide with glycerol or triethanolamine. The possibilities and limitations of the method are discussed. High collection efficiencies (over 95%) were obtained at relative humidities above 25%. Collected sulfur dioxide was stable for at least

C. Huygen

1963-01-01

95

New analytical reagents for the determination of sulfur dioxide and carbon monoxide  

Microsoft Academic Search

Four solid reagent methods were developed for the determination of sulfur dioxide in air, and one method was developed to measure carbon monoxide. When applied to filter paper with acetamide as the humectant and 4-phenylcyclohexanone as a bisulfite absorbent, oxohydroxybis(8-hydroxyquinolinyl-) vanadium (V) changes from yellow to black in the presence of sulfur dioxide. The three other methods, also on a

Trump

1987-01-01

96

A New Style High Precision Sulfur Dioxide Measurement Mechanics of Zero Variation  

Microsoft Academic Search

In order to enhance measurement precision of sulfur dioxide, the improved sensor mechanics are studied. According to Lambert-Beer Law, the mathematic model of sulfur dioxide measurement is deduced, which is about strength ratio of reference beam and measuring beam. Reversible look-up table is deduced to solve the nonlinearity variation problem in this mathematic model, and it achieves linearity of the

Gong Rui-kun; Wang Ru-lin; Chen Lei

2007-01-01

97

Studies on the Removal of Sulfur Dioxide from Hot Flue Gases to Prevent Air Pollution  

Microsoft Academic Search

The pollution of the atmosphere by sulfur dioxide is one of the gravest of all in public nuisance problems, especially in the industrial regions. A practically applicable method in industry for the removal of sulfur dioxide has been studied. The Kiyoura-T .I .T. process utilizes the oxidation method to convert S02 of the flue gas to S03 in the presence

Raisaku Kiyoura

1966-01-01

98

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

99

Nitrogen fixation rate and chlorophyll content of the lichen Peltigera canina exposed to sulfur dioxide  

SciTech Connect

In general, the rate of nitrogen fixation decreased when the lichen Peltigera canina (L.) Willd. was exposed to sulfur dioxide gas at levels from 0.1 to 500 ppm; at 30 ppm, however, nitrogen fixation was stimulated. The chlorophyll content decreased as the level of sulfur dioxide increased.

Henriksson, E.; Pearson, L.C.

1981-01-01

100

Direct synthesis of dimethyl carbonate with supercritical carbon dioxide: Characterization of a key organotin oxide intermediate  

Microsoft Academic Search

The direct synthesis of dimethyl carbonate (DMC) using carbon dioxide as solvent and reagent for its fixation to methanol was explored with di-n-butyldimethoxystannane in order to get insight into the reaction mechanism for activity improvement. Catalytic runs including recycling experiments allowed isolation and characterization by NMR, IR, and single-crystal X-ray diffraction of a new tin complex containing 10 tin atoms.

Danielle Ballivet-Tkatchenko; Stphane Chambrey; Riitta Keiski; Rosane Ligabue; Laurent Plasseraud; Philippe Richard; Helka Turunen

2006-01-01

101

78 FR 47191 - Air Quality Designations for the 2010 Sulfur Dioxide (SO2) Primary National Ambient Air Quality...  

Federal Register 2010, 2011, 2012, 2013

...By revising the table heading for ``West Virginia--SO 2 '' to read ``West Virginia--1971 Sulfur Dioxide NAAQS (Primary...0 b. By adding a new table entitled ``West Virginia--2010 Sulfur Dioxide NAAQS...

2013-08-05

102

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

Code of Federal Regulations, 2013 CFR

...Measurement of Sulfur Dioxide in the Atmosphere (Ultraviolet Fluorescence Method...Measurement of Sulfur Dioxide in the Atmosphere (Ultraviolet Fluorescence Method...interference. 4.0Calibration Procedure Atmospheres containing accurately known...

2013-07-01

103

Chemistry of ascorbic acid and sulfur dioxide as an antioxidant system relevant to white wine.  

PubMed

The impact of the combined ascorbic acid and sulfur dioxide antioxidants on white wine oxidation processes was investigated using a range of analytical techniques, including flow injection analysis for free and total sulfur dioxide and two chromatographic methods for ascorbic acid, its oxidative degradation products and phenolic compounds. The combination of different analytical techniques provided a fast and simultaneous means for the monitoring of oxidation processes in a model wine system. In addition, the initial mole ratio of sulfur dioxide to ascorbic acid was varied and the model wine complexity was increased by the inclusion of metal ions (copper(II) and iron(II)). Sulfur dioxide was found not to be a significant binder of ascorbic acid oxidative degradation products and could not prevent the formation of certain phenolic pigment precursors. The results provide a detailed insight into the ascorbic acid/sulfur dioxide antioxidant system in wine conditions. PMID:22688051

Barril, Clia; Clark, Andrew C; Scollary, Geoffrey R

2011-11-15

104

Air pollutant sensitivity of pea plants when simulating conditions around sulfur dioxide point sources  

SciTech Connect

Peas (Pisum sativum L.) are often grown in areas where coal-powered generating stations are present and are exposed to sulfur dioxide from these stations. In addition to sulfur dioxide, ozone is nearly always present in these areas. Present studies were designed to determine sensitivity of peas to sulfur dioxide and ozone at dosages simulating those around stations in Wisconsin. Peas were exposed to several concentrations of ozone and sulfur dioxide, singly or in combination, for two hours. Injury was observed with ozone concentrations above 0.09 ..mu..l l/sup -1/ and sulfur dioxide concentrations above 0.66 ..mu..l l/sup -1/. Injury was increased by concentrations of ozone as low as 0.02 ..mu..l l/sup -1/ when in combination with sulfur dioxide, and by concentrations of sulfur dioxide as low as 0.12 ..mu..l l/sup -1/ when in combination with ozone. Peas pretreated with ozone at non-injurious concentrations prior to exposure with ozone-sulfur dioxide mixtures at injurious concentrations had less injury than those not pretreated. Reduced injury in pretreated plants was associated with stomatal closure. Plants exposed to ozone-sulfur dioxide mixtures for two hours at different times of the day were injured most at midday. Increased injury at midday was associated with increases in stomatal conductances. However, changes in injury and conductance were not associated with abscisic acid concentrations. Peas preconditioned for six days at 77% relative humidity prior to exposure with ozone and/or sulfur dioxide were injured more than those preconditioned at 36% relative humidity. Increased injury at the higher humidity was associated with greater stomatal conductances. When peas were subjected to 31 or 67% relative humidities during pollutant exposures, injury was similar.

Kobriger, J.M.

1983-01-01

105

Rapid determination of formaldehyde and sulfur dioxide in food products and Chinese herbals  

Microsoft Academic Search

Simple, sensitive and rapid methods for the determination of formaldehyde and sulfur dioxide were developed. The formaldehyde determination is based on the reaction between formaldehyde and acetylacetone solution, producing yellow 3,5-diacetyl-l-1,4-dihydrolutidine. Sulfur dioxide was detected as the deoxidize of sulfurous acid by zinc in acidic medium, which produces sulfureted hydrogen that make lead acetate paper blackening due to lead sulfide

Shuo Wang; Xiaojun Cui; Guozhen Fang

2007-01-01

106

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

107

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

108

Development of a method for the sampling and analysis of sulfur dioxide and nitrogen dioxide from ambient air  

Microsoft Academic Search

A method has been developed to permit the simultaneous sampling of SO and NO from ambient air. Sulfur dioxide and NO are collected on triethanolamine-impregnated glass fiber filters. After sampling, the filters are extracted, and the extract is analyzed for sulfate, nitrite, and nitrate using ion chromatography. Ambient concentrations are computed from the recovered nitrogen and sulfur and the sampled

Joseph E. Sickles; Peter M. Grohse; Laura L. Hodson; Cynthia A. Salmons; Kelly W. Cox; Ann R. Turner; Eva D. Estes

1990-01-01

109

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

110

Estimate of the contribution of biologically produced dimethyl sulfide to the global sulfur cycle.  

PubMed

Atmospheric dimethyl sulfide (DMS) measurements were made on the Atlantic Coast of the United States at Wallops Island and Cape Henry, Virginia, during June 1975. The very low concentrations, typically less than 30 parts per trillion observed at the Cape Henry site, were thought to result from the smog chemistry associated with the Norfolk metropolitan area. Atmospheric DMS concentrations at the Wallops Island site were much higher, having a geometric mean of 58 parts per trillion and a geometric standard deviation of 2.1. At this site the DMS source strength was estimated to be 6 milligrams of sulfur per square meter per year. Because of wind conditions during this experiment, the DMS source strength is thought to be representative of the DMS source strength of the ocean in the Wallops Island area and is much less than the 130 milligrams of sulfur per square meter per year needed to balance the ocean-atmosphere portion of the global sulfur budget. PMID:17760057

Maroulis, P J; Bandy, A R

1977-05-01

111

STABILITY EVALUATION OF AMBIENT CONCENTRATIONS OF SULFUR DIOXIDE, NITRIC OXIDE, AND NITROGEN DIOXIDE CONTAINED IN COMPRESSED GAS CYLINDERS  

EPA Science Inventory

Compressed gas samples of sub-part per million concentrations of sulfur dioxide, nitric oxide, and nitrogen dioxide were evaluated for long and short term stability. Except for several stainless steel tanks, the samples were contained in aluminum cylinders. A degree of stability ...

112

Sulfur dioxide: A versatile reagent for the processing of cobaltic oxide minerals  

NASA Astrophysics Data System (ADS)

Cobaltic oxide minerals are readily dissolved in mildly acidic sulfuric solutions provided a reducing agent is also present. Sulfur dioxide is the most common reductant recommended for this purpose, but its addition during the leaching step could lead to significant environmental problems and could affect the recovery of copper if present in large amounts. This paper presents a novel approach whereby the reductant used during the leach is ferrous sulfate and sulfur dioxide is added at a later stage in a controlled manner to regenerate the reductant after any copper present has been recovered. Sulfur dioxide can also be used during purification of the cobalt bleed, where, blended with oxygen, it constitutes a powerful oxidant capable of selectively oxidizing and precipitating manganese away from the cobalt. This paper will present several applications of the use of sulfur dioxide as a primary reductant, a regenerant for ferrous sulfate, and a selective oxidant for manganese.

Ferron, C. Joe

2008-10-01

113

Reactions of sulfur dioxide with ammonia: Dependence on oxygen and nitric oxide  

SciTech Connect

The influence of oxygen and nitric oxide on the reactions of sulfur dioxide with ammonia were studied in a simulated flue gas in the range of 0--20% oxygen and 0--300 ppm nitric oxide at temperatures in the range of 40--60 C. A Fourier transform infrared spectrometer (FT-IR) analyzed the reaction products deposited on the reactor surface and revealed that ammonium sulfate was the main product of the reactions, with sulfamic acid and ammonium sulfamate as the minor products. The results showed that oxygen and nitric oxide enhanced the oxidation reactions of sulfur dioxide to form ammonium sulfate. The yield of the minor products markedly increased in the presence of nitrogen dioxide. The size and number concentration of product aerosols increased at lower temperature. The fraction of sulfur dioxide which formed aerosols increased with sulfur dioxide removal.

Hirota, Koichi; Maekelae, J.; Tokunaga, Okihiro [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan)

1996-10-01

114

Measurement and biological significance of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices  

Microsoft Academic Search

This review deals with the measurement of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices of rats and humans (blood, serum, tissues, urine, breath, feces and flatus). Hydrogen sulfide and methanethiol both contain the active thiol (SH) group and appear in the free gaseous form, in the acid-labile form and in the dithiothreitol-labile form.

Albert Tangerman

2009-01-01

115

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

116

Effect of sulfur dioxide on cytokine production of human alveolar macrophages in vitro  

SciTech Connect

Tumor necrosis factor-{alpha}, interleukin-1{Beta}, interleukin-6, and transforming growth factor-{Beta} are cytokines synthesized by alveolar macrophages. We investigated the effect of sulfur dioxide, a major air pollutant, on the production of these cytokines by alveolar macrophages. The cells were layered on a polycarbonate membrane and exposed for 30 min to 0.0, 1.0, 2.5, and 5.0 ppm sulfur dioxide at 37 {degrees}C and 100% air humidity. The cells were incubated for 24 h after exposure, thus allowing cytokine release. Cytotoxic effects of sulfur dioxide were evaluated by trypan flue exclusion. Cytokine release. Cytotoxic effects of sulfur dioxide were evaluated by trypan blue exclusion. Cytokines were measured with enzyme-linked immunosorbent assays (i.e., tumor necrosis factor-{alpha}, interleukin-1{Beta}, and interleukin-6) or by use of a specific bioassay (i.e., transforming growth factor-{Beta}). The toxicity of sulfur dioxide for alveolar macrophages ranged from 3.1% to 9.5%. A 30-min exposure to sulfur dioxide induced a significant decrease in spontaneous and lipopolysaccharide-stimulated tumor necrosis factor-{alpha} (p < .001) and lipopolysaccharide-stimulated interleukin-1{Beta} release (p < .05). The release of interleukin-6 and transforming growth factor-{Beta} was not affected significantly by sulfur dioxide exposure. Our results demonstrated a functional impairment of alveolar macrophages after sulfur dioxide exposure (i.e., release of tumor necrosis factor-{alpha} and interleukin-1{Beta}). Neither spontaneous nor stimulated release of interleukin-6 and transforming growth factor-{Beta} were influenced by exposure to sulfur dioxide. 31 refs., 3 figs.

Knorst, M.M.; Kienast, K.; Mueller-Quernheim, J.; Ferlinz, R. [Johannes Gutenberg Univ., Mainz (Germany)

1996-03-01

117

40 CFR 52.2679 - Control strategy and regulations: Sulfur dioxide.  

Code of Federal Regulations, 2013 CFR

...PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Guam § 52.2679 Control strategy and regulations: Sulfur dioxide. (a) Approvals of the following rules are...

2013-07-01

118

Evaluation of Some Regenerable Sulfur Dioxide Absorbents for Flue Gas Desulfurization.  

National Technical Information Service (NTIS)

The vapor pressure of sulfur dioxide above aqueous solutions of citric acid (2-hydroxy-1,2,3-propanetricarboxylic acid), glycolic acid (hydroxyacetic acid), 1-methyl-2-pyrrolidone, ethylenediamine (1,2 diaminoethane), and diethylenetriamine (2,2' diaminod...

C. H. Schwartz D. J. Wildman R. J. Walker S. J. Gasior

1982-01-01

119

The Reaction of Dioxygen Difluoride and Sulfur Dioxide. Transfer of the Oof Group.  

National Technical Information Service (NTIS)

The reaction of dioxygen difluoride with sulfur dioxide produces mainly sulfuryl fluoride and lesser amounts of pyrosulfuryl fluoride and fluorosulfuryl hypofluorite. The mechanism of this reaction was studied using O17-tracer techniques and O17 nmr measu...

I. J. Solomon A. J. Kacmarek J. Raney

1968-01-01

120

Atmospheric Oxidation of Flue Gases from a Partially Sulfur Dioxide-Scrubbed Power Plant. Study II.  

National Technical Information Service (NTIS)

A series of 12 airborne plume sampling experiments was conducted in the Widows Creek Steam Plant plume. The principal purpose of these experiments was to investigate the atmospheric chemistry of the plume from the wet limestone sulfur dioxide scrubber uni...

E. M. Bailey R. W. Garber J. F. Meagher R. J. Bonanno L. Stockburger

1981-01-01

121

Determination of Sulfur Dioxide and Nitrogen Oxide Concentration in Flue Gas.  

National Technical Information Service (NTIS)

The aim was to investigate the reliability of measurements of sulfur dioxide and nitrogen oxide concentration in flue gas and of the efficiency of three emission monitoring instruments used in Danish power plants. Measuring methods are also examined. The ...

B. Colliander H. Moeller P. R. Nielsen

1988-01-01

122

Sulfur dioxide measurement in marine atmosphere at concentrations lower than ppb  

Microsoft Academic Search

In order to measure the low concentrations of sulfur dioxide in remote areas, the West-Gaeke method was used. A marine origin for an oceanic background value of 0.1 microgram\\/cu m has been established.

B. Bonsang; B. C. Nguyen

1978-01-01

123

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

Federal Register 2010, 2011, 2012, 2013

...Minnesota; Sulfur Dioxide SIP Revision for Marathon Petroleum St. Paul Park AGENCY: Environmental...State Implementation Plan revision for Marathon Petroleum in St. Paul Park. This submittal...Implementation Plan (SIP) revision request for Marathon Petroleum Co, LLC, (Marathon)...

2010-12-28

124

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...

125

Control of Sulfur Dioxide Emissions from Copper Smelters: Volume II. Hydrogen Sulfide Production from Copper Concentrates.  

National Technical Information Service (NTIS)

A laboratory investigation has been made of a modified copper smelting process which provides a solution to the sulfur dioxide air pollution problem. Preliminary economic evaluation of the process appears favorable with good prospects for further improvem...

C. A. Rohrmann H. T. Fullam

1974-01-01

126

Sulfur dioxide emissions from primary copper smelters in the western US  

SciTech Connect

The body of information presented is directed to environmental scientists and policy makers without chemical or metallurgical engineering backgrounds. This paper addresses the problems of reducing sulfur dioxide emissions from primary copper smelters in the western United States and projects the future impact of emissions within a framework of legal, technological, and economic considerations. Methodology used to calculate historical sulfur dioxide emissions is described. Sulfur dioxide emission regulations are outlined as they apply to primary copper smelters. A discussion of available sulfur dioxide control technology and copper smelting processes summarizes the technological and economic problems of reducing copper smelter emissions. Based upon these technological and economic considerations, projections of smelter emissions indicate that compliance with existing legislative requirements will be achieved by 1990. Three smelters are projected to close by 1985.

Mangeng, C.A.; Mead, R.W.

1980-01-01

127

Electrochemical oxidation of wine polyphenols in the presence of sulfur dioxide.  

PubMed

Electrochemical oxidation of three representative wine polyphenols (catechin, caffeic acid, and quercetin) in the presence of sulfur dioxide in a model wine solution (pH = 3.3) was investigated. The oxidation was undertaken using chronoamperometry at a rotating glassy carbon rod electrode, and the reaction products were characterized by HPLC-MS. The mechanism of electrochemical oxidation of polyphenols in the presence of sulfur dioxide was proposed to be an ECEC mechanism. The polyphenols first underwent a one-electron oxidation to a semiquinone radical, which can be reduced back to the original polyphenol by sulfur dioxide, or further oxidized to the quinone form. In the cases of caffeic acid and catechin, the quinone combined with sulfur dioxide and produced new derivatives. The quercetin quinone underwent further chemical transformations, producing several new compounds. The proposed mechanisms were confirmed by digital simulation of cyclic voltammograms. PMID:23692398

Makhotkina, Olga; Kilmartin, Paul A

2013-06-03

128

Absorption tube for removal of interfering sulfur dioxide in analysis of atmospheric oxidant  

Microsoft Academic Search

A method of removing sulfur dioxide from a mixture with ozone thus allowing accurate determination of atmospheric oxidants is described. The method consists of an absorption tube containing chromium trioxide filter paper. Interference from nitric oxide is discussed.

Bernard E. Saltzman; Arthur F. Wartburg

1965-01-01

129

Continuous Monitoring of Sulfur Dioxide with a Gas Permeation Denuder-Based System  

Microsoft Academic Search

.?This study describes a continuous flow procedure for monitoring atmospheric sulfur dioxide using a planar gas permeation\\u000a denuder (GPD) and a fiber optic spectrometer. When gaseous samples are directed through a GPD which consists of a gas-permeable\\u000a membrane of poly(vinylidene) difluoride and two perspex blocks with engraved channels of mirror image, the fraction of sulfur\\u000a dioxide passing the membrane is

Zhong-Xian Guo; Xin-Xiang Zhang; Yi Gao; Yuan-Zong Li; Wen-Bao Chang; Yun-Xiang Ci

2003-01-01

130

Partial molar volumes of sulfur dioxide in organic solvents: Formation of charge-transfer complexes  

Microsoft Academic Search

New apparatus for measuring the apparent molar volumes of gases in liquids is described. The apparatus has been used to obtain the limiting partial molar volume of sulfur dioxide in 17 organic solvents. The limiting partial molar volume of sulfur dioxide is found to be significantly smaller in electron-donating solvents that in non-electron-donating solvents, with this difference being interpreted in

John F. Smith; Gerald A. Bottomley; Leslie Barta; Loren G. Hepler

1990-01-01

131

Measurement of sulfur dioxide with the differential optical absorption technique combined with Fourier transformation  

Microsoft Academic Search

The concentration of sulfur dioxide has been measured in the ultraviolet spectral range with a combination of the differential optical absorption technique and Fourier transformation. Measurements have been made with a pathlength of two meters and a measuring time of one minute. Sulfur dioxide levels of less than 0.1 ppm (volume) were assessed with a measurement uncertainty of [plus minus]0.03

L. Axelsson; A. Lauber

1992-01-01

132

The application of EPA method 6 to high sulfur dioxide concentrations. Final report  

Microsoft Academic Search

The application of EPA test method (M-6) to the analysis of higher sulfur dioxide concentrations than had previously been employed has been studied. The use of prepared gas mixtures showed that the method is efficient for the measurement of gaseous sulfur dioxide in concentrations of up to 80,000 mg\\/m. The investigation also showed no evidence of retention of significant quantities

J. E. Knoll; M. R. Midgett

1976-01-01

133

Spectrophotometric Determination of Atmospheric Sulfur Dioxide with 4(4-Aminophenylazo)-1-naphthylamine  

Microsoft Academic Search

The use of a p-aminophenylazoic dye, viz. 4-(4-aminophenylazo)-1-naphthylamine, is proposed as a spectrophotometric reagent for the determination of atmospheric sulfur dioxide absorbed in sodium tetrachloromercurate solutions. Determinations are made in ethanol-dye-formaldehyde systems displaying a red color at a pH value of 1.3. In the presence of sulfur dioxide solutions the red color turns to a blue one, which has a

G. E. Baiulescu; P. C. Marcuta; D. M. Marinescu

1973-01-01

134

The effect of gas-phase chemistry on aqueous-phase sulfur dioxide oxidation rates  

Microsoft Academic Search

The rates and mechanisms of both gas and liquid phase reactions for the oxidation of sulfur dioxide play an important role in the production of atmospheric acids and aerosol particles. Rhodeet al. (1981) concluded that sulfate production rates were highly non-linear functions of sulfur dioxide emission rates. Their modelling study used an HOx termination mechanism for the HOSO2 reaction in

William R. Stockwell

1994-01-01

135

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

136

Ambient air concentration of sulfur dioxide affects flight activity in bees  

PubMed Central

Three long-term (16-29 days) low-level (0.14-0.28 ppm) sulfur dioxide fumigations showed that exposure to this 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.

1980-01-01

137

Determination of sulfur dioxide in wine using headspace gas chromatography and electron capture detection.  

PubMed

Sulfites are routinely added as preservatives and antioxidants in wine production. By law, the total sulfur dioxide content in wine is restricted and therefore must be monitored. Currently, the method of choice for determining the total content of sulfur dioxide in wine is the optimised Monier-Williams method, which is time consuming and laborious. The headspace gas chromatographic method described in this study offers a fast and reliable alternative method for the detection and quantification of the sulfur dioxide content in wine. The analysis was performed using an automatic headspace injection sampler, coupled with a gas chromatograph and an electron capture detector. The method is based on the formation of gaseous sulfur dioxide subsequent to acidification and heating of the sample. In addition to free sulfur dioxide, reversibly bound sulfur dioxide in carbonyl compounds, such as acetaldehyde, was also measured with this method. A total of 20 wine samples produced using diverse grape varieties and vintages of varied provenance were analysed using the new method. For reference and comparison purposes, 10 of the results obtained by the proposed method were compared with those acquired by the optimised Monier-Williams method. Overall, the results from the headspace analysis showed good correlation (R = 0.9985) when compared with the conventional method. This new method requires minimal sample preparation and is simple to perform, and the analysis can also be completed within a short period of time. PMID:23176364

Aberl, A; Coelhan, M

2012-11-23

138

Sulfur dioxide-induced chronic bronchitis in beagle dogs  

SciTech Connect

This study was done to produce a model of chronic bronchitis. Twelve beagle dogs were exposed to 500 ppm sulfur dioxide (SO/sub 2/) for 2 h/d, 5d/wk for 21 wk and 4 dogs were sham-exposed to filtered ambient air for the same period. Exposure effects were evaluated by periodically examining the dogs using chest radiographs, pulmonary function, tracheal mucous clearance, and the cellular and soluble components of bronchopulmonary lavage fluids. Dogs were serially sacrificed after 13 and 21 wk of exposure and after 6 and 14 wk of recovery. Clinical signs produced in the SO/sub 2/-exposed dogs included mucoid nasal discharge, productive cough, moist rales on auscultation, tonsilitis, and conjunctivitis. Chest radiographs revealed mild peribronchiolar thickening. Histopathology, tracheal mucous clearance measurements, and lavage cytology were consistent with a diagnosis of chronic bronchitis. It is concluded that repeated exposure to 500 ppm SO/sub 2/ for 21 wk produced chronic bronchitis in the beagle dog. Complete recovery occurred within 5 wk following cessation of SO/sub 2/ exposure. 43 references, 2 figures, 2 tables.

Greene, S.A.; Wolff, R.K.; Hahn, F.F.; Henderson, R.F.; Mauderly, J.L.; Lundgren, D.L.

1984-01-01

139

Dynamics of sulfur dioxide absorption in excised porcine tracheae  

SciTech Connect

The absorption of sulfur dioxide (SO{sub 2}) into excised porcine tracheae was characterized by a step-response experiment in which SO{sub 2} outlet concentration was monitored during the 30-min interval following introduction of inlet concentrations of 0.1-0.6 ppm at steady air flows of 2.7-11.0 liter/min. These data were analyzed with a diffusion-reaction theory incorporating three independent parameters-a gas phase mass transfer coefficient, k{sub g}, a tissue phase diffusivity {times} solubility product, D({alpha}RT){sup 2}, and a tissue phase reaction constant, k{sub r}. While single values of 17 sec{sup {minus}1} for k{sub r} and 0.28 m{sup 2}/sec for D({alpha}RT){sup 2} were sufficient to simulate all the data, it was necessary to vary k{sub g} from 0.032 to 0.121 m/sec in direct proportion to the gas flow. Based on these parameter values, gas phase resistance accounts for about one-fourth of the total resistance to absorption in gas and tissue phases combined. All three parameters were independent of inlet concentration, implying that diffusion, solubility, and irreversible reaction of SO{sub 2} in tissue are all linear processes.

Ben-Jebria, A.; Full, A.P.; DeMaria, D.D.; Ball, B.A.; Ultman, J.S. (Pennsylvania State Univ., University Park (USA))

1990-12-01

140

Anthropogenic sulfur dioxide emissions measured from GOME-2  

NASA Astrophysics Data System (ADS)

Global measurements of sulfur dioxide can be made from space with the GOME-2 (Global Ozone Monitoring Experiment) instrument using backscattered radiation in the ultraviolet region of the spectrum. We apply an optimal estimation algorithm originally developed for retrieving tropospheric ozone and ozone profiles from GOME and the Ozone Monitoring Instrument (OMI) to derive SO2 from GOME-2 observations. This approach combines a retrieval algorithm and a full radiative transfer model with climatological profiles from the GEOS-Chem chemical transport model to implicitly include the effects of albedo, clouds, and ozone and SO2 profiles in the analysis. Surface SO2 is inferred from GOME-2 column measurements of SO2 using GEOS-Chem profiles. We assess GOME-2 measurements of anthropogenic SO2 using data from North American networks of in situ surface observations and perform comparisons with modeled SO2 from GEOS-Chem. We also examine the possibility of simultaneously deriving SO2 amount and plume altitude information in cases of up-lofted SO2 pollution.

Nowlan, C. R.; Liu, X.; Chance, K.; Kurosu, T. P.; Martin, R. V.; Philip, S.

2011-12-01

141

Seasonal fuel switching to natural gas - A logical approach to reduce sulfur dioxide and other air emissions  

Microsoft Academic Search

This analysis examines a method for reducing sulfur dioxide and other air pollutant emissions which may have major benefits over other control strategies. This control technique involves the substitution of natural gas for higher sulfur fuels on a seasonal basis, as opposed to a year-round basis. That is, a 20 percent annual sulfur dioxide reduction goal could be met by

1985-01-01

142

Adsorption of sulfur dioxide on ammonia-treated activated carbon fibers  

Microsoft Academic Search

A series of activated carbon fibers (ACFs) and ammonia-treated ACFs prepared from phenolic fiber precursors have been studied to elucidate the role of pore size, pore volume, and pore surface chemistry on adsorption of sulfur dioxide and its catalytic conversion to sulfuric acid. As expected, the incorporation of basic functional groups into the ACFs was shown as an effective method

C. L. Mangun; J. A. DeBarr; J. Economy

2001-01-01

143

Solid sorbent for collecting atmospheric sulfur dioxide. Final report may 75-nov 77  

Microsoft Academic Search

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, consisting of Puramer S coated open cell polyurethane foam, can be used to fix the quantities of sulfur

R. J. Cotter; S. G. Jr Smith

1979-01-01

144

An in situ infrared study of dimethyl carbonate synthesis from carbon dioxide and methanol over zirconia  

SciTech Connect

The mechanism of dimethyl carbonate (DMC) synthesis from methanol and carbon dioxide over monoclinic zirconia has been investigated using in situ infrared spectroscopy. The dissociative adsorption of methanol occurs more slowly than the adsorption of carbon dioxide, but the species formed from methanol are bound more strongly. Upon adsorption, the oxygen atom of methanol binds to coordinately unsaturated Zr4+ cations present at the catalyst surface. Rapid dissociation of the adsorbed methanol leads to the formation of a methoxide group (Zr-OCH3) and the release of a proton, which reacts with a surface hydroxyl group to produce water. Carbon dioxide inserts in the Zr-O bond of the methoxide to form a mondentate methyl carbonate group (Zr-OC(O)OCH3). This process is facilitated by the interactions of C and O atoms in CO2 with Lewis acid-base pairs of sites (Zr4+O2-) on the surface of the catalyst. Methyl carbonate species can also be produced via the reaction of methanol with carbon dioxide adsorbed in the form of bicarbonate species with methanol, a process that results in the transfer of a methyl group to the carbonate and restores a hydroxyl group to the zirconia surface. The decomposition of DMC on monoclinic zirconia has also been investigated and has been observed to occur via the reverse of the processes described for the synthesis of DMC.

Jung, Kyeong Taek; Bell, Alexis T.

2001-03-11

145

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...

146

Remote sensing of ammonia, sulfur dioxide, and nitrogen dioxide emissions from cars and trucks  

NASA Astrophysics Data System (ADS)

This document describes the development of a remote sensor for mobile source ammonia (NH3), sulfur dioxide (SO2), and nitrogen dioxide (NO2) based on an instrument previously developed at the University of Denver. Significant optical upgrades allow for the detection of three new species. Detection and quantification of NH3 and SO 2 use wavelengths deeper into the ultraviolet region than previously possible. Currently NH3 is quantified from three peaks at 209 nm, 213 nm, and 217 nm; SO2 from three peaks at 219 nm, 221 nm, and 222 nm; NO2 using the spectral window 430--446 nm. The instrument was demonstrated in the measurement of emissions from both gasoline and diesel light duty vehicles and heavy duty diesel trucks (HDDT). The remote sensor was used for over 20,000 measurements of NH3 and SO2 emissions from motor vehicles in Denver and Tulsa in the summer of 2005. Nitrogen dioxide emissions were measured at the Denver site only. For the first time, on-road vehicle NH3 and SO2 emission trends versus model year were observed. Ammonia is a larger percentage of the exhaust than previously predicted for newer vehicles and its production reaches a maximum with approximately the 1996 model year. NH3 is the first pollutant observed to have lower emissions from the oldest model year. Sulfur dioxide emissions decrease with newer model year vehicles. Nearly 1200 NH3, SO2, and NO2 emission measurements with valid vehicle identification numbers were collected from in-use HDDTs in Golden and Dumont, CO. The Dumont weigh station site allowed emissions to be correlated with gross vehicle weight. No trends were apparent. The Golden site allowed emissions to be correlated with odometer and a trend of increasing oxides of nitrogen (NOx) emissions was apparent even near one million miles, when some vehicles should show lower emissions due to engine rebuild and computer reflash. For the first time HDDT on-road NO x emissions were shown versus vehicle model year and found to reach a maximum with model years in the mid to late 1990s. Gross emitting SO 2 emissions were found for 1% of the fleet possibly arising from the illegal use off-road diesel fuel.

Burgard, Daniel Alexander

147

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

148

Atmospheric Concentrations of Sulfur Dioxide and Nitrogen Dioxide in China and Korea Measured by Using the Improved Passive Sampling Method  

Microsoft Academic Search

The results of ambient sulfur dioxide (SO2) and nitrogen dioxide (NO2) concentrations measured in ten cities of China and Korea by the improved passive samplers are reported. The property of this sampler is the utilization for the long-term exposure to the high level of SO2 and NO2. In this method, the conversion coefficients from the analytical data to the ambient

Munehiro Warashina; Masanobu Tanaka; Yoshio Tsujino; Tuguo Mizoguchi; Siro Hatakeyama; Yasuaki Maeda

2001-01-01

149

Measurement of formaldehyde, nitrogen dioxide, and sulfur dioxide at Whiteface Mountain using a dual tunable diode laser system  

Microsoft Academic Search

An application of a dual tunable diode laser absorption spectrometer (TDLAS) to ambient measurements of formaldehyde (HCHO), nitrogen dioxide (NO2) and sulfur dioxide (SO2) is described. During the PM2.5 Technology Assessment and Characterization Study-New York (PMTACS-NY) 2002 intensive field campaign at Whiteface Mountain, New York, a dual TDLAS was deployed during a field instrument comparison study along with five other

Y. Q. Li; K. L. Demerjian; M. S. Zahniser; D. D. Nelson; J. B. McManus; S. C. Herndon

2004-01-01

150

Modeling the gas and liquid-phase resistances in the dry scrubbing process for sulfur dioxide removal  

SciTech Connect

A spray of tiny droplets containing water and calcium hydroxide is used to absorb and react with sulfur dioxide. Simultaneously, water evaporates from the droplets, and solid particles are formed. These particles contain calcium sulfite (the reaction product), unreacted calcium hydroxide, and a small amount of equilibrium moisture. The process is modeled as a spray of isolated droplets that undergo no internal circulation. Sulfur dioxide mass transfer is treated as a series of resistance in the gas and liquid. In the liquid, dissolved sulfur dioxide diffuses through a stagnant film to react with calcium hydroxide. A monodisperse spray is considered first, followed by a polydisperse spray. The effects of important process variables on the conversion of sulfur dioxide are explored in both systems. For instance, as more water is sprayed into the gas, the conversion of sulfur dioxide increases, because the liquid surface area is greater and the droplets take longer to dry. The conversion also increases as more calcium hydroxide is added to the liquid, because the liquid-phase resistance decreases. The conversion decreases substantially at high sulfur dioxide concentration, because less sulfurous acid ionizes. Backmixing the gas often increases the conversion of sulfur dioxide, because the droplets dry more slowly. Reducing the size of the monodispersion, or the mean size of the polydispersion, also increases the conversion, because the equilibrium moisture has greater surface area. The conversion of sulfur dioxide in a monodispersion is compared with the conversion of sulfur dioxide in a polydispersion having the same volume to surface ratio.

Kinzey, M.K. Jr.

1988-01-01

151

Remote sensing of sulfur dioxide effects on vegetation: spectral reflectance of soybeans and winter wheat exposed to sulfur dioxide in experimental plots  

Microsoft Academic Search

Remote measurements of the spectral reflectance of experimental, 0.40 ha plots of soybeans (Glycine max (L.) Merr. var Essex) and winter wheat (Triticum aestivum (L.) var Coker 68-15) were made after the plants were given controlled exposures of sulfur dioxide (SO) and the foliar effects were observed and recorded. The plots were divided into subplots, each of which was treated

Sapp

1980-01-01

152

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

153

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

154

Seasonal trends of atmospheric nitrogen dioxide and sulfur dioxide over North Santa Clara, Cuba.  

PubMed

Atmospheric nitrogen dioxide (NO2) and sulfur dioxide (SO2) levels were monitored simultaneously by means of Radiello passive samplers at six sites of Santa Clara city, Cuba, in the cold and the warm seasons in 2010. The dissolved ionic forms of NO2 and SO2 as nitrate and sulfite plus sulfate, respectively, were determined by means of ion chromatography. Analysis of NO2 as nitrite was also performed by UV-Vis spectrophotometry. For NO2, significant t tests show good agreement between the results of IC and UV-Vis methods. The NO2 and SO2 concentrations peaked in the cold season, while their minimum levels were experienced in the warm season. The pollutant levels do not exceed the maximum allowable limit of the Cuban Standard 39:1999, i.e., 40?g/m(3) and 50?g/m(3) for NO2 and SO2, respectively. The lowest pollutant concentrations obtained in the warm season can be attributed to an increase in their removal via precipitation (scavenging) while to the decreased traffic density and industrial emission during the summer holidays (e.g., July and August). PMID:23208757

Alejo, Daniellys; Morales, Mayra C; de la Torre, Jorge B; Grau, Ricardo; Bencs, Lszl; Van Grieken, Ren; Van Espen, Piet; Sosa, Dismey; Nuez, Vladimir

2012-12-04

155

Sorption of sulfur dioxide by carbonate rocks impregnated with inorganic salts  

SciTech Connect

The purpose of this work was to compare data on sorption of sulfur dioxide with data characterizing thermal decomposition of carbonate sorbents. Impregnation of carbonate sorbents with inorganic salts improves significantly the effectiveness of sulfur dioxide removal (from gases containing considerable amounts of carbon dioxide) at 400-600/sup 0/. Under conditions of sulfur dioxide removal from gases by the injection, additives which raise the rate of thermal decomposition of the composites are effective, while under conditions of filtration purification additives which have little influence on the rate of thermal decomposition of the composites are preferable. The differences in the effectiveness of different additives in purification of flue gases depend on the sizes of the zones of thermal decomposition of salt-impregnated rocks, and on the duration of contact between the gas and the sorbent.

Dvali, T.S.; Shumyatskii, Yu.I.

1988-09-20

156

Is sulfur accumulation in sulfur dioxide-exposed plants related to biomass reduction  

SciTech Connect

Sulfur (S) is an abundant element in the Earth's crust. It is a major plant nutrient,necessary in plant metabolism. Normally, S is taken up from soil in the sulphate form and assimilated into various compounds. Sulfur dioxide (SO[sub 2]) absorbed from the air can also supply S for nutrition. Of all plant organs, the leaves have the highest S content. SO[sub 2] is an air contaminant, especially a consequence of burning fossil fuels, as well as having significant natural sources. Plants exposed to excessive SO[sub 2] levels may be associated with visible injury and biomass production perturbation. Two questions may be raised: is S accumulation correlated with other responses, such as resistance or tolerance to SO[sub 2] and can S accumulation be a useful tool for diagnostic purposes when SO[sub 2] is suspected of being responsible for altered plants Unfortunately, these questions are not easily answered. It takes a substantial build-up before any increase is significant. Accumulation may also be influenced by the level of S nutrition. Experiments under controlled conditions are essential. Many experiments performed in the past used rather high SO[sub 2] concentrations and short duration, but the extrapolation to [open quote]natural[close quote] situations is difficult. Results here reported refer to experiments carried out in order to get more information on some aspects of sulphur accumulation in plants under realistic, nonmarking, SO[sub 2] pollution conditions, in connection with biomass production. 18 refs., 1 fig., 3 tabs.

Lorenzini, G.; Panicucci, A. (Universitari e Perfezionamento Sant'Anna, Pisa (Italy))

1994-06-01

157

Application of synthetic molecular sieve zeolites and silica gel towards the separation of sulfur dioxide from combustion gases  

Microsoft Academic Search

Sulfur dioxide loadings were greatest for the type 13X molecular sieve followed by AW500 molecular sieve. The effect of gas throughput was minimal which suggests that mass transfer was adsorbent side controlling. As gas temperature increased, sulfur dioxide adsorption decreased linearly for 100 percent sulfur dioxide concentration and non-linearly for low concentrations (0.003 percent). The effect of water vapor on

1979-01-01

158

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

SciTech Connect

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, J.E.; Bates, T.S. [NOAA, Seattle, WA (United States)

1993-12-01

159

Synthesis of dimethyl carbonate from methanol, propylene oxide and carbon dioxide over KOH\\/4A molecular sieve catalyst  

Microsoft Academic Search

The synthesis of dimethyl carbonate (DMC) from methanol, propylene oxide (PO) and carbon dioxide (CO2) over supported catalysts was studied for the first time. A series of supported solid base catalysts were prepared by impregnation and their catalytic activities were evaluated. It was found that KOH\\/4A molecular sieve was the most effective catalyst. The effects of various conditions, such as

Yuan Li; Xin-qiang Zhao; Yan-ji Wang

2005-01-01

160

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

161

Measurement and biological significance of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices.  

PubMed

This review deals with the measurement of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices of rats and humans (blood, serum, tissues, urine, breath, feces and flatus). Hydrogen sulfide and methanethiol both contain the active thiol (-SH) group and appear in the free gaseous form, in the acid-labile form and in the dithiothreitol-labile form. Dimethyl sulfide is a neutral molecule and exists only in the free form. The foul odor of these sulfur volatiles is a striking characteristic and plays a major role in bad breath, feces and flatus. Because sulfur is a biologically active element, the biological significance of the sulfur volatiles are also highlighted. Despite its highly toxic properties, hydrogen sulfide has been lately recommended to become the third gasotransmitter, next to nitric oxide and carbon monoxide, based on high concentration found in healthy tissues, such as blood and brain. However, there is much doubt about the reliability of the assay methods used. Many artifacts in the sulfide assays exist. The methods to detect the various forms of hydrogen sulfide are critically reviewed and compared with findings of our group. Recent findings that free gaseous hydrogen sulfide is absent in whole blood urged the need to revisit its role as a blood-borne signaling molecule. PMID:19505855

Tangerman, Albert

2009-05-21

162

High-Capacity Sulfur Dioxide Absorbents for Diesel Emissions Control  

SciTech Connect

High capacity sulfur dioxide absorbents based on manganese oxide octahedral molecular sieves (OMS) have been identified. These materials are based on MnO6 octahedra sharing faces and edges to form various tunnel structures (2x2, 2x3, 2x4, 3x3) differentiated by the number of octahedra on a side. The SO2 capacities of these materials, measured at 325 C with a feed containing 250 ppmv SO2 in air, are as high as 70wt% (wt/wt), remarkably higher than conventional metal oxide-based SO2 absorbents. Among the OMS materials the 2x2 member, cryptomelane, exhibits the highest capacity and adsorption rate. Its SO2 absorption behavior has been further characterized as a function of temperature, space velocity, and feed composition. The dominant pathway for SO2 absorption is through the oxidation of SO2 to SO3 by Mn4+ followed by SO3 reaction with Mn2+ to form MnSO4. Absorption can occur in the absence of gas phase oxygen, with a moderate loss in overall capacity. The inclusion of reducible gases NO and CO in the feed does not reduce SO2 capacity. The absorption capacity decreases at high space velocity and lower absorption temperature, indicating the important role of diffusion of sulfate from the surface to the bulk of the material in order to reach full capacity. A color change of cryptomelane from black to yellow-brown after SO2 absorption can be used as an indicator of absorption progress. Cryptomelane can be synthesized using MnSO4 as a reagent. Therefore, after full SO2 absorption the product MnSO4 can be re-used as raw material for a subsequent cryptomelane synthesis. Cryptomelane has a similarly high capacity toward SO3, therefore it can be used for removal of all SOx species generated from a variety of combustion sources. Cryptomelane may find application as a replaceable absorbent for the removal of SOx from diesel truck exhaust, protecting downstream emissions control devices such as particulate filters and NOx traps.

Li, Liyu; King, David L.

2005-01-05

163

Outdoor air concentrations of nitrogen dioxide and sulfur dioxide and prevalence of wheezing in school children.  

PubMed

We report analysis of data on outdoor air pollution and respiratory symptoms in children collected in the Czech part of the international Small Area Variations in Air pollution and Health (SAVIAH) Project, a methodological study designed to test the use of geographical information systems (GIS) in studies of environmental exposures and health at small area level. We collected the following data in two districts of Prague: (1) individual data on 3,680 children (response rate 88%) by questionnaires; (2) census-based socio-demographic data for small geographical units; (3) concentrations of nitrogen dioxide (NO2) and sulfur dioxide (SO2) measured by passive samplers in three 2-week surveys at 80 and 50 locations, respectively. We integrated all data into a geographical information system. Modeling of NO2 and SO2 allowed estimation of exposure to outdoor NO2 and SO2 at school and at home for each child. We examined the associations between air pollution and prevalence of wheezing or whistling in the chest in the last 12 months by logistic regression at individual level, weighted least squares regression at small area (ecological) level and multilevel modeling. The results varied by the level of analysis and method of exposure estimation. In multilevel analyses using individual data, odds ratios per 10 microg/m3 increase in concentrations were 1.16 (95% CI = 0.95-1.42) for NO2, and 1.08 (95% CI = 0.97-1.21) for SO2. While mapping of spatial distribution of NO2 and SO2 in the study area appeared valid, the interpolation from outdoor to personal exposures requires consideration. PMID:11021612

Pikhart, H; Bobak, M; Kriz, B; Danova, J; Celko, M A; Prikazsky, V; Pryl, K; Briggs, D; Elliott, P

2000-03-01

164

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

Code of Federal Regulations, 2013 CFR

...elemental sulfur, alkylation acid, hydrogen sulfide, organic sulfides and...of the stoichiometric amount of hydrogen peroxide absorbent. (ii) The test methods...total sulfur content expressed as hydrogen sulfide in excess of 350...

2013-07-01

165

PROTOTYPE CORRELATION MASK FLAME PHOTOMETRIC DETECTOR FOR MEASURING SULFUR DIOXIDE  

EPA Science Inventory

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

166

40 CFR 60.163 - Standard for sulfur dioxide.  

Code of Federal Regulations, 2013 CFR

... Standards of Performance for Primary Copper Smelters § 60.163 Standard for sulfur...from any roaster, smelting furnace, or copper converter any gases which contain sulfur...the total smelter charge at the primary copper smelter contains a high level of...

2013-07-01

167

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

168

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

169

Determination of nitrogen dioxide, sulfur dioxide, ozone, and ammonia in ambient air using the passive sampling method associated with ion chromatographic and potentiometric analyses  

Microsoft Academic Search

Concentrations of nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and ammonia (NH3) were determined in the ambient air of Al-Ain city over a year using the passive sampling method associated with ion chromatographic\\u000a and potentiometric detections. IVL samplers were used for collecting nitrogen and sulfur dioxides whereas Ogawa samplers were\\u000a used for collecting ozone and ammonia. Five sites representing

Alaa A. Salem; Ahmed A. Soliman; Ismail A. El-Haty

2009-01-01

170

Anomalous Emissions of Sulfur Dioxide and Seismicity of San Miguel Volcano, EL Salvador in October, 2006  

NASA Astrophysics Data System (ADS)

San Miguel (also known as Chaparrastique) volcano in eastern El Salvador is located 15 km southwest of the city of San Miguel. This volcano has erupted more than 30 times since 1699, with the last gas and ash emission on January 16, 2002. During 2006, San Miguel presented anomalous gas emissions and seismicity. In this work, the seismic parameters reported by SNET (Servicio Nacional de Estudios Territoriales de El Salvador) and the crater gas emissions measured by researchers of the University of El Salvador are compared. For the gas efflux, two types of measurements were done using the Mini-DOAS system (Galle et al., 2002): transects around the crater perimeter (~100 m) and transects following roads located between 5 and 10 km from the crater. Several measurements between October 2005 and May 2006 indicate that the sulfur dioxide efflux during quiet periods is around 20 ton/day. From May to June 2006, a progressive increase in fumarolic activity and noise from gas emissions were observed. From May to August 2006, the sulfur dioxide emissions increased to 60 ton/day. A seismic crisis started on October 9, 2006, increasing the RSAM from 10-20 to 208 on October 10, 2006. During this time, the sulfur dioxide efflux reached a maximum of 492 ton/day. This increase in sulfur dioxide efflux represents 25 times the basic emissions during the previous quiet period and 8 times the values observed from May to August 2006. The correlation coefficient between sulfur dioxide efflux and RSAM values during this period of time was 0.81, which is statistically significant at a level higher than 99.9% . These anomalous changes in seismicity and sulfur dioxide emissions at San Miguel volcano suggest a magmatic reactivation with an increase in the exsolution of magma volatiles, long period seismic events, and volcanic tremor.

Olmos, R.; Barahona, F.; Hernndez, A.; Cartagena, R.; Henrquez, B.; Lpez, D.; Crdenas, C.; Galle, B.

2007-12-01

171

Measurements of sulfur dioxide during GASIE with the mist chamber technique  

Microsoft Academic Search

This paper highlights the performance of the mist chamber\\/ion chromatography (MC\\/IC) technique for measuring atmospheric sulfur dioxide (SO2) during the Gas-Phase Sulfur Intercomparison Experiment (GASIE). The technique was found to be free of interference from CO, CO2, CH4, NOx, 03, CH3SCH3, and H20 vapor. Repeated measurements at various mixing ratios of SO2 indicated that the coefficient of variation in the

R. W. Talbot; E. M. Scheuer; B. L. Lefer; W. T. Luke

1997-01-01

172

Measurements of sulfur dioxide during GASIE with the mist chamber technique  

Microsoft Academic Search

This paper highlights the performance of the mist chamber\\/ion chromatography (MC\\/IC) technique for measuring atmospheric sulfur dioxide (SO2) during the Gas-Phase Sulfur Intercomparison Experiment (GASIE). The technique was found to be free of interference from CO, CO2, CH4, NOx, O3, CH3SCH3, and H2O vapor. Repeated measurements at various mixing ratios of SO2 indicated that the coefficient of variation in the

R. W. Talbot; E. M. Scheuer; B. L. Lefer; W. T. Luke

1997-01-01

173

Advanced byproduct recovery: Direct catalytic reduction of sulfur dioxide to elemental sulfur. Quarterly report, April 1--June 30, 1997  

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. 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, the authors 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. Progress is reported from all three organizations.

NONE

1997-12-31

174

Regioselective substitution at carbon atom vinical to doubly bonded tertiary carbon atom by sulfur dioxide catalysts  

SciTech Connect

A process for regioselective isomerization of organic compounds having a carbon-carbon double bond at a tertiary carbon atom by sulfur dioxide induced allylic rearrangement of a hydrogen atom and/or replacement of a proton in the allylic position by a deuteron. The organic compound is contacted with sulfur dioxide at temperatures between about 0/sup 0/ and 70/sup 0/ C. For a time sufficient to effect such isomerization to a more stable isomer; and if deuteration is to take place D2O is provided in the solution.

Masilamani, D.; Rogic, M.M.

1980-10-07

175

Kinetics of sorption of sulfur dioxide by anion-exchange resins  

SciTech Connect

The important role of sulfur dioxide as an environmental pollutant stimulated the development of studies of the sorption of this gas by different adsorbents, including anion-exchange resins. The results of a study of the kinetics of sorption of sulfur dioxide by styrene-divinyl benzene anion-exchangers with other types of functional amino groups, primary, secondary, and quaternary, which have elevated absorptivity with respect to SO/sub 2/ in extraction of SO/sub 2/ from gas-air mixtures, are reported in the present article.

Kats, B.M.; Malinovskii, E.K.; Al'tshul', V.Ya.

1986-12-20

176

PULMONARY RESPONSE TO THRESHOLD LEVELS OF SULFUR DIOXIDE (1.0 PPM) AND OZONE (0.3 PPM) (JOURNAL VERSION)  

EPA Science Inventory

The authors exposed 22 healthy adult non-smoking men for 2 hours to either filtered air, 1.0 ppm sulfur dioxide, 0.30 ppm ozone or the combination of 1.0 ppm sulfur dioxide plus 0.30 ppm ozone. It was hypothesized that exposure to near threshold concentrations of these pollutants...

177

Some Regularities in Absorption of Sulfur Dioxide by Woody Plants (Nekotorye Zakonomernosti Poglosheniya Sernistogo gaza Drevesnym Rasteniyami).  

National Technical Information Service (NTIS)

The study using labeled sulfur dioxide (Nikolayevskiy, et al., 1971) establishes that the susceptibility to injury of leaves by sulfur dioxide, in trees, flowers, lawn grasses and weeds, is directly proportional to the rate of absorption of the gas and fo...

V. S. Nikolaevskii

1971-01-01

178

Sensitivity studies on sulfur dioxide measurements with satellite-borne solar backscattered ultraviolet spectrometer  

Microsoft Academic Search

The Ozone and Pollution measuring Ultraviolet Spectrometer (OPUS) is scheduled to launch on board the GCOM A1 satellite, to measure ozone, sulfur dioxide (SO2), nitrogen dioxide (NO2) and other chemical species including aerosols. OPUS measures the backscattered ultraviolet radiance with the wavelength step of 0.5 nm in ultraviolet-near infrared regions. This wavelength step is coarse compared with that of GOME,

Masaharu Watanabe; Makoto Suzuki; Takuki Sano; Toshihiro Ogawa; Kazuo Shibasaki; Akihiko Kuze; Takahiro Kawashima

2002-01-01

179

Advanced Byproduct Recovery: Direct Catalytic Reduction of Sulfur Dioxide to Elemental Sulfur. Sixth quarterly technical progress report, January - March 1997  

SciTech Connect

More than 170 wet scrubber systems applied, to 72,000 MW of U.S., coal-fired, utility boilers are in operation or under construction. In these systems, the sulfur dioxide removed from 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). Due to the abundance and low cost of naturally occurring gypsum, and the costs associated with producing an industrial quality product, less than 7% of these scrubbers are configured to produce usable gypsum (and only 1% of all units actually sell the byproduct). The disposal of solid waste from each of these scrubbers requires a landfill area of approximately 200 to 400 acres. In the U.S., a total of 19 million tons of disposable FGD byproduct are produced, transported and disposed of in landfills annually. The use of regenerable sorbent technologies has the potential to reduce or eliminate solid waste production, transportation and disposal. In a regenerable sorbent system, the sulfur dioxide in the boiler flue gas is removed by the sorbent in an adsorber. The S0{sub 2}s subsequently released, in higher concentration, in a regenerator. All regenerable systems produce an off-gas stream from the regenerator that must be processed further in order to obtain a salable byproduct, such as elemental sulfur, sulfuric acid or liquid S0{sub 2}.

NONE

1997-03-01

180

Advanced Byproduct Recovery: Direct Catalytic Reduction of Sulfur Dioxide to Elemental Sulfur. Fifth quarterly technical progress report, December 1996  

SciTech Connect

More than 170 wet scrubber systems applied, to 72,000 MW of U.S., coal-fired, utility boilers are in operation or under construction. In these systems, the sulfur dioxide removed from 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). Due to the abundance and low cost of naturally occurring gypsum, and the costs associated with producing an industrial quality product, less than 7% of these scrubbers are configured to produce usable gypsum (and only 1% of all units actually sell the byproduct). The disposal of solid waste from each of these scrubbers requires a landfill area of approximately 200 to 400 acres. In the U.S., a total of 19 million tons of disposable FGD byproduct are produced, transported and disposed of in landfills annually. The use of regenerable sorbent technologies has the potential to reduce or eliminate solid waste production, transportation and disposal. In a regenerable sorbent system, the sulfur dioxide in the boiler flue gas is removed by the sorbent in an adsorber. The S0{sub 2}s subsequently released, in higher concentration, in a regenerator. All regenerable systems produce an off-gas stream from the regenerator that must be processed further in order to obtain a salable byproduct, such as elemental sulfur, sulfuric acid or liquid S0{sub 2}.

NONE

1996-12-01

181

Measurement of Sulfur Dioxide Reaction Rates in Wintertime Orographic Clouds  

NASA Astrophysics Data System (ADS)

Releases of sulfur dioxide (SO_2 ) into the wintertime orographic clouds at Elk Mountain in southeastern Wyoming were utilized to accelerate the rate of SO_2 oxidation to cloud -water-dissolved sulfate (SO_sp{4} {2-}). Background SO_2 mixing ratios were 0.6 part-per-billion by volume (ppbv) and were consistent with the remote location of the experimental site and with supplemental cloud water, snow, and aerosol composition measurements. Background mixing ratios of hydrogen peroxide (H_2O _2) and the organohydroperoxides, expressed as methyl hydroperoxide (MHP), were 0.15 and 0.17 ppbv, respectively. The concentration of H_2O _2 in cloud water, obtained as rime, was also monitored. Observed concentrations were always lower than concentrations calculated assuming partition equilibrium with gas-phase H_2O _2. Analysis of these findings suggests that both reactive loss of H_2O _2 and volatilization during riming are mechanisms for H_2O _2 loss. The pseudo first-order SO_2 depletion rates, measured as the change in the equivalent mixing ratio of cloud-water-dissolved SO_sp {4}{2-} per unit SO _2 mixing ratio and per unit in-cloud reaction time, varied between 2 and 71%/hr (x = 32 +/- 22%/hr, n = 10). Observed depletions of H _2O_2 (x = 0.030 ppbv) were consistent with observed yields of SO_sp {4}{2-} (x = 0.027 ppbv) and with model predictions. This result is contrasted with the work of Chandler et al. (1989) who observe that field measurements of the bisulfite-H_2O _2 rate constant, in northern England, are approximately a factor of ten larger than laboratory measurements. Observed depletions of MHP were not significantly different from 0.0 ppbv. This observation is both consistent with the much smaller solubility of MHP, compared with H_2O_2, and with the results of 16 model simulations, which were initialized with cloud water and air composition measurements. With the exception of two model simulations, reactions between dissolved SO_2 and O _3, between SO_2 and O_2 (catalyzed by Mn(II) and Fe(III)), and between SO_2 and HCHO were calculated to contribute less than 40% to the total amount of SO _sp{4}{2-}. These reactions were inferred to be inhibited by the low pH (< 5) of the Elk Mountain cloud water. It is concluded that H_2O_2 is the dominant SO_2 oxidant in these clouds, and that the laboratory measurements form an adequate basis for predicting the rate of in-cloud oxidation of SO_2 by H_2O _2.

Snider, Jefferson Robert

182

Laboratory and field measurements of a badge type passive sampler for the determination of ambient sulfur dioxide concentrations  

Microsoft Academic Search

The performance of a badge type passive sampler for the determination of sulfur dioxide is described. The trapping agent\\u000a is triethanolamine. Analysis is performed by ion chromatography. Thus, the method allows the simultaneous detection of sulfur\\u000a dioxide and nitrogen dioxide. The sampler was tested in the laboratory and in the field. The intercomparison with independent\\u000a methods in the field showed

Anne Kasper-Giebl; Sabine Krenn; Hans Puxbaum

1999-01-01

183

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

184

Chemical kinetics model for sulfur dioxide removal in flue gas using corona discharge  

Microsoft Academic Search

Plasma remediation is being investigated for the removal of sulfur dioxide from automotive exhausts and gases generated by combustion of fossil fuels. Modeling is playing an increasing vital role in process optimization and understanding of governing physical and chemical process. In this paper, a chemical kinetics model is developed to analyze the time evolution of the different main species involved

L. M. Dong; Z. Wu; J. X. Yang; X. C. Chi

2003-01-01

185

Solubilities and heats of solution of sulfur dioxide and hydrogen chloride in disulfur dichloride  

Microsoft Academic Search

Data on the solubilities and solution heats of sulfur dioxide and hydrogen chloride in disulfur dichloride are presented for the purpose of optimizing the removal of these compounds from gases resulting from the production of thionyl chloride. Their removal has been found to contribute to the overall efficiency and productivity of thionyl chloride production and has also made possible their

V. I. Geiko; V. I. Gladushko; A. Ya. Borovikov

1987-01-01

186

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...

187

Effect Of Reagent (Dye) Addition In Wet Chemical Method Of Sulfur Dioxide Determination In Ambient Air  

Microsoft Academic Search

For measurement of sulfur dioxide (SO2) in ambient air, the United States Environment Protection Agency (US EPA) had recommended the PRA dye-based colorimetric method as a reference technique. The method has been developed and applied in many countries for a longtime; however information regarding the sensitivity of the method with respect to sampling and analysis conditions is not available. Collaborative

S. K. GOYAL; Nehru Marg

2006-01-01

188

Application Research on Evaluation of the Sulfur Dioxide Discharge in Power Plant  

Microsoft Academic Search

As three traditional methods show some deficiencies in the measure of Sulfur Dioxide (SO2) discharge. In this paper, the deficiencies are not only analyzed in monitoring the SO2 discharge, but also in its application. It has been improved that the method named Conservation Calculation of Material Method has been used before. The improvement could help to measure and calculate the

Wu Yunna; Ji Gedi; Chang Qing

2010-01-01

189

Physiologic responses of plants to sulfur dioxide and other environmental stresses  

Microsoft Academic Search

Red pine and paper birch seedlings exposed to sulfur dioxide produced acetaldehyde and ethanol, and increased in production of ethylene and ethane. Gas chromatographic measurement of head space gas from incubation tubes containing leaves or seedlings was a simple method of simultaneously measuring all four compounds. Acetaldehyde and ethanol were produced by plants with no visible injury, and production of

Kimmerer

1982-01-01

190

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

Microsoft Academic Search

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.

Marika P. Dalton; I. Matthew Watson; Patricia A. Nadeau; Cynthia Werner; Jeremy M. Shannon

2009-01-01

191

Atmospheric Sulfur Dioxide and Particulate Matter A Comparison of Methods of Measurements  

Microsoft Academic Search

Comparison of the results obtained from great numbers of samples using several different methods of measuring both ambient sulfur dioxide and particulate matter indicated that two different concurrent standard methods of measuring a single pollutant may give significantly different average results. In some communities, a fairly good to excellent correlation appears to exist between some of the different components of

William W. Stalker; Richard C. Dickerson; George D. Kramer

1963-01-01

192

Accurate and precise coulometric determination of sulfur dioxide in compressed gas mixtures  

Microsoft Academic Search

Sulfur dioxide (SO2) in the atmosphere is a common pollutant and is a major contributor to the formation of acid rain. Accurate and precise determinations of SO2 in the atmosphere are essential to determine the magnitude of the problem. Reference gas mixtures such as NIST SRMs are an important part of the measurement procedure. Coulometry has been established as an

G. D. Mitchell; A. A. Bell

1991-01-01

193

Concentration evaluation method using broadband absorption spectroscopy for sulfur dioxide monitoring  

Microsoft Academic Search

We report on an approach for sulfur dioxide monitoring using broadband absorption spectroscopy in the ultraviolet spectral range. The method was applied in real-time measurements and has the advantage of straightforward data evaluation, limited susceptibility for interference from other gases, and low degree of complexity compared with other real-time optical detection techniques having the same precision. Concentration measurement is demonstrated

F. Xu; Z. Lv; Y. G. Zhang; G. Somesfalean; Z. G. Zhang

2006-01-01

194

DIFFERING RESPONSE OF ASTHMATICS TO SULFUR DIOXIDE EXPOSURE WITH CONTINUOUS AND INTERMITTENT EXERCISE  

EPA Science Inventory

Ten mild asthmatics were initially exposed in an environmental chamber (26 c, 70% RH) to clean air and 1.0 ppm sulfur dioxide while performing three sets of 10 minutes treadmill exercise (ventilation = 41 1/min) and 15 minutes rest. To evaluate the effects of the pattern and dura...

195

Reducing emissions of sulfur dioxide when a pulp mill switches to coal  

Microsoft Academic Search

Methods that are available to help pulp mills with coalfired furnances meet federal emission standards are reviewed. Probable impacts of EPA's New Source Performance Standards on sulfur dioxide emission control standards are assessed. Flue gas desulfurization techniques available to the pulp and paper mill industry are described. Sodium alkali is used by many paper mills that have scrubber systems to

W. Ellison; W. R. Groff

1979-01-01

196

An assessment of spatial and temporal variation of sulfur dioxide levels over Istanbul, Turkey  

Microsoft Academic Search

Sulfur dioxide concentration levels are investigated in Istanbul to assess air pollution during the heating seasons in which the concentration of air pollutants reach high levels due to the consumption of low-quality fossil fuels. Results reveal that in the 198591 period there is an increasing trend in the concentrations of air pollutants. One reason for this increase is found to

M Tayan

2000-01-01

197

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...

198

Sulfur Dioxide Emission Rates from Kilauea Volcano, Hawaii, an Update: 2002-2006.  

National Technical Information Service (NTIS)

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 oth...

A. J. Sutton T. Elias

2007-01-01

199

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...

200

DEVELOPMENT OF FEDERAL AIR STANDARDS TO REDUCE SULFUR DIOXIDE EMISSIONS FROM NEW INDUSTRIAL BOILERS  

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, proposed by EPA on June 19,...

201

Acute effects of sulfur dioxide exposure on the middle ear mucosa  

SciTech Connect

A variety of atmospheric pollutants are known to depress mucociliary function in the respiratory system. Since the mucociliary function in the middle ear is similar, and the middle ear may be invaded by atmospheric pollutants, we decided to investigate the possible contribution of sulfur dioxide to middle ear effusion. Guinea pigs were exposed for 24 hours to 300 ppm of sulfur dioxide or air. Immediately after exposure, ciliary activity and epithelial structure were examined close to the tympanic orifice (proximal site) and more distal to it (distal site). In the animals exposed to sulfur dioxide, no effusion was found in the tympanic cavity. Ciliary activity was reduced only in the distal site. Electron microscopy demonstrated hypersecretion in the proximal site and severe pathologic changes in the distal site. Although the normally functioning cilia in the proximal site may prevent retention of surplus secretions in the ear, sulfur dioxide may promote middle ear effusion when combined with other detrimental factors, because it stimulates mucus secretion in the proximal site and impairs ciliary function in the distal site.

Ohashi, Y.; Nakai, Y.; Ikeoka, H.; Koshimo, H.; Esaki, Y.

1989-04-01

202

COMBINED EFFECT OF SULFUR DIOXIDE AND OZONE ON BEAN AND TOBACCO PLANTS  

EPA Science Inventory

Plants of two cultivars of Phaseolus vulgaris and one cultivar of Nicotiana tabacum were exposed to a replicated series of concentrations of sulfur dioxide (SO2), ozone (03), and combinations of these two air pollutants for single four-hour periods. Experiments were performed in ...

203

REMOTE SENSING OF SULFUR DIOXIDE EFFECTS ON VEGETATION. VOLUME I. SUMMARY  

EPA Science Inventory

Three techniques for detecting and mapping sulfur dioxide (SO2) effects on the foliage of sensitive crops and trees near large, coal-fired power plants were tested and evaluated. These techniques were spectroradiometry, photometric analysis of aerial photographs, and computer ana...

204

REMOTE SENSING OF SULFUR DIOXIDE EFFECTS ON VEGETATION. FINAL REPORT. VOLUME I: SUMMARY  

EPA Science Inventory

Three techniques for detecting and mapping sulfur dioxide (SO sub 2 ) effects on the foliage of sensitive crops and trees near large, coal-fired power plants were tested and evaluated. These techniques were spectroradiometry, photometric analysis of aerial photographs, and comput...

205

Study on sulfur dioxide transport from China to Japan using an advection and dispersion model  

Microsoft Academic Search

The current study investigated a series of transport processes of sulfur dioxide, which is an acid material transported from China to Japan in the winter season, through material transport simulations using the advection and dispersion model HYSPLIT4 (Hybrid Single-Particle Lagrangian Integrated Trajectory version 4), which has been developed by Draxler et al. This model assumes materials can be represented by

S. Watanabe; M. Hasebe; S. Matsuda

206

40 CFR 60.4330 - What emission limits must I meet for sulfur dioxide (SO2)?  

Code of Federal Regulations, 2013 CFR

...of Performance for Stationary Combustion Turbines Emission Limits § 60.4330 What...sulfur dioxide (SO2 )? (a) If your turbine is located in a continental area, you...or (a)(3) of this section. If your turbine is located in Alaska, you do not...

2013-07-01

207

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...

208

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...

209

Associations of London, England, Daily Mortality with Particulate Matter, Sulfur Dioxide, and Acidic Aerosol Pollution  

Microsoft Academic Search

During the extreme pollution episodes of 1952 and 1962 in London, England, excesses in daily mortality were clearly evident. In this study, we examined daily British Smoke, sulfur dioxide, acid aerosols, and weather variables for their short-term associations with daily mortality in the more typical (nonepisodic) winters of 19651972. Consideration of the acid aerosol data was of special interest because

Kazuhiko Ito; George D. Thurston; Carl Hayes; Morton Lippmann

1993-01-01

210

Experimental Inhibition of Carbonate Mineral Precipitation by Sulfur Dioxide: Implications for Early Mars  

Microsoft Academic Search

Sulfur dioxide (SO2) is abundant in terrestrial volcanic emissions and was likely at least as abundant in early martian emissions. Recent photochemical studies indicate that during episodes of vigorous volcanic activity, the atmospheric lifetime of SO2 may have been sufficiently long for it to have helped maintain liquid water on the surface of Mars and perhaps to have regulated the

I. Halevy; D. P. Schrag

2009-01-01

211

Sulfur dioxide-releasing perforated plastic liners to control postharvest gray mold of Redglobe table grapes  

Technology Transfer Automated Retrieval System (TEKTRAN)

"Gray mold, caused by Botrytis cinerea, limits the duration of table grape storage. Periodic sulfur dioxide (SO2) fumigation and in-package SO2 generating pads are two common strategies that protect grapes after harvest. Our objectives were to compare the effectiveness of packaging Redglobe grapes i...

212

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...

213

Use of a conical scrubber to remove sulfur dioxide from sintering-machine waste gases  

Microsoft Academic Search

The Institute VNIIchermetenergoochistka proposed a technology for removing sulfur dioxide from gas with a conical scrubber. A commercial scrubber was refitted by installing an insert in the hollow cylindrical scrubber which featured a two-stage spraying system using limestone suspension. Results from tests comparing the new scrubber with a cylindrical scrubber found that higher gas flow velocities in the lower part

G. M. Kanenko; M. P. Kostin; L. N. Olkhovskaya; E. A. Orlova; I. D. Chapala

1988-01-01

214

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...

215

Relationship between Exposure Duration and Sulfur Dioxide-Induced Bronchoconstriction in Asthmatic Subjects.  

National Technical Information Service (NTIS)

The purpose of the study was to determine the shortest duration of exposure to 1.0 ppm sulfur dioxide (SO2) sufficient to induce bronchoconstriction significantly greater than that observed with exposure to clean air (CA) in exercising SO2 sensitive asthm...

D. H. Horstman E. Seal L. J. Folinsbee P. Ives L. J. Roger

1988-01-01

216

Method for removing sulfur dioxide from flue gases  

SciTech Connect

A method is described for removing sulfur oxide compounds from flue gases. The method comprises forming a slurry of calcium oxide and water, exothermically reacting the slurry of calcium oxide and water to form a hydrate containing saturated water and calcium hydroxide, flashing the saturated water to steam to break up the calcium hydroxide into very fine particles and passing the fine particles of calcium hydroxide in a counterflow relationship with the flue gases so that the sulfur oxide compounds from the flue gases are reacted with the calcium hydroxide particles.

Sommerlad, R.E.

1987-05-19

217

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...

218

Investigation of the diffusion process for the extraction of sulfur dioxide from gaseous mixtures  

SciTech Connect

The removal of sulfur-containing compounds from industrial gases is a most urgent problem. Most of the existing methods for removal of SO/sub 2/ from exhaust gases are based on the use of various chemical processes. However, all these methods, such as the sulfite-bisulfite method, ozone catalysis, ammonia-sulfuric acid method and others, have a number of shortcomings: high cost and high consumption of reagents, in many cases irreversible absorption of SO/sub 2/, low economic efficiency. The present study deals with an analysis of the possibilities of practical application of the diffusion method for purification of exhaust gases using selective gas-permeable membranes. This method assures that the purification process will be continuous, eliminates the use of chemical reagents, and makes it possible to enrich the gaseous mixture to SO/sub 2/ concentrations sufficient for further processing of the sulfur dioxide to sulfuric acid. The work consisted of two basic stages: selection of material for fabrication of separative membranes and investigation of the process of extraction of sulfur dioxide from gaseous mixtures. The investigation revealed the theoretical possibility of the extraction of SO/sub 2/ from exhaust gases using membranes made from polydimethylsiloxane. Optimum process conditions were found: a gaseous mixture containing 1.5% SO/sub 2/ can be enriched to 6% sulfur dioxide with a coefficient of extraction of 70%. The data obtained were used to design a pilot plant facility for removal of sulfur-containing compounds from exhaust gases. 1 reference, 2 figures, 2 tables.

Beyyakov, V.P.; Chekalov, L.N.; Talakin, O.G.; Chanina, I.E.; Sviridova, V.I

1980-04-01

219

Gas chromatographic studies of the relative retention of the sulfur isotopes in carbonyl sulfide, carbon disulfide, and sulfur dioxide  

SciTech Connect

A precision gas chromatograph, coupled to a quadrupole mass spectrometer and an on-line computer, was used to study the fractionation on Porasil A of the /sup 32/S//sup 34/S isotopic pair in a variety of sulfur-containing molecules. Carbonyl sulfide yielded an average ..cap alpha.. value of 1.00074 +- 0.00017 (standard deviation) for the temperature range 25 to 75/sup 0/C. The carbon disulfide value was 1.00069 +- 0.00023 for the range 53 to 103/sup 0/C, and that for sulfur dioxide was 1.00090 +- 0.00018 for the range 62 to 112/sup 0/C. Differential thermodynamic data have been reported. A Porapak Q column showed no fractionation of this isotopic pair in these three molecules.

Fetzer, J.C.; Rogers, L.B.

1980-01-01

220

Gas chromatographic studies of the relative retention of the sulfur isotopes in carbonyl sulfide, carbon disulfide, and sulfur dioxide  

SciTech Connect

A precision gas chromatograph, coupled to a quadrupole mass spectrometer and an on-line computer, was used to study the fractionation on Porasil A of the /sup 32/S//sup 34/S isotopic pair in a variety of sulfur-containing molecules. Carbonyl sulfide (COS) yielded an average ..cap alpha.. value of 1.00074 +- 0.00017 (standard deviation) for the temperature range 25/sup 0/C to 75/sup 0/C. The carbon disulfide (CS/sub 2/) value was 1.00069 +- 0.00023 for the range 53/sup 0/C to 103/sup 0/C, and that for sulfur dioxide (SO/sub 2/) was 1.00090 +- 0.00018 for the range 62/sup 0/C to 112/sup 0/C. Differential thermodynamic data have been reported. A Porapak Q column showed no fractionation of this isotopic pair in these three molecules.

Fetzer, J.C.; Rogers, L.B.

1980-01-18

221

Sulfur dioxide leaching of spent zinccarbon-battery scrap  

Microsoft Academic Search

Zinccarbon batteries, which contain around 20% zinc, 35% manganese oxides and 10% steel, are currently disposed after use as land fill or reprocessed to recover metals or oxides. Crushed material is subjected to magnetic separation followed by hydrometallurgical treatment of the non-magnetic material to recover zinc metal and manganese oxides. The leaching with 2M sulfuric acid in the presence of

J. Avraamides; G. Senanayake; R. Clegg

2006-01-01

222

The tropospheric oxidation of dimethyl sulfide: A new source of carbonyl sulfide  

SciTech Connect

The authors present the results of laboratory measurements of the oxidation of dimethyl sulfide (CH{sub 3}SCH{sub 3}) mediated by OH. They observe the formation of sulfur dioxide, dimethyl sulfoxide, and carbonyl sulfide. The latter branching ratio represents a previously unreported source of carbonyl sulfide (OCS). It is significant because OCS is the major reservoir of gaseous sulfur in the earth`s atmosphere.

Barnes, I.; Becker, K.H.; Patroescu, I. [Bergische Universitaet, Wuppertal (Germany)

1994-11-01

223

Project on sulfur dioxide removal and waste products utilization process. Final report  

SciTech Connect

The report describes the pilot plant evaluation for a unique process designed for effectively removing sulfur dioxide from stack gas and converting it into useful product as construction materials, chemical for water and wastewater treatment. The product can also be recycled for further SO/sub x/ removal. The product are particles having a core of lime surrounded by a shell of anhydrous calcium sulfate, which has a plurality of cracks. The product has been given a coined name Linfan. The process evaluation has shown that it is very efficient in sulfur oxide (SO/sub 2/ and SO/sub 3/) removal, 100% or near 100% removal efficiency has been attained.

Lin, P.W.

1984-06-01

224

Advection of sulfur dioxide over the western Atlantic Ocean during CITE 3  

SciTech Connect

During the NASA Chemical Instrumentation Test and Evaluation 3 sulfur intercomparison over the western Atlantic Ocean, five techniques for the determination of sulfur dioxide were evaluated. The response times of the techniques varied from 3 to 30 min. Based on the ensemble of measurements reported, it was clear that advection of SO2 from the North American continent occurred in the boundary layer (altitude less than 1 km) with only one exception. The vertical distribution of SO2 above the boundary layer for the northern and southern Atlantic Ocean was remarkably similar duing this experiment.

Thornton, D.C.; Bandy, A.R.; Beltz, N.; Driedger, A.R. III; Ferek, R. [Drexel Univ., Philadelphia, PA (United States)]|[Univ. of Frankfurt, Frankfurt (Germany)]|[Univ. of Washington, Seatlle, WA (United States)

1993-12-01

225

Sulfur dioxide adsorption from exhaust gases by adsorbents based on 2,4,6-triamino-1,3,5-triazine  

SciTech Connect

The equilibrium dynamic capacity of polymer materials based on 2,4,6-triamino-1,3,5-triazine has been determined. The possibility of their application as absorbents of sulfur dioxide from exhaust gases has been shown.

Postnikova, I.N.; Pavlova, I.V.; Kogtev, S.E. [Nizhnii Novgorod State Engineering Univ., Novgorod (Russian Federation)] [and others

1995-05-10

226

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; L, Zhenmei

2003-09-01

227

Sulfur dioxide emission rates from K?lauea Volcano, Hawaii, 20072010  

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 20072010.

Elias, T.; Sutton, A. J.

2012-01-01

228

Effect of relative humidity on the detection of sulfur dioxide and sulfuric acid using a chemical ionization mass spectrometer  

NASA Astrophysics Data System (ADS)

Detection of sulfur dioxide and sulfuric acid at high relative humidity was studied using a chemical ionization mass spectrometer (CIMS). The reactant ions used in the experiments are CO3-.nH2O (n=0-5), which react with SO2 to form SO5-.nH2O (n=0-2). H2SO4 reacts with the precursor ions to form HSO4- (m/z=97 amu) and H2SO4.CO3- (m/z=158 amu). We report the first use of the latter ionization scheme to detect sulfuric acid. High RH affects the detection of SO2 and H2SO4 by forming clusters with the reactant and product ions, reducing sensitivity. Increasing the temperature breaks these clusters. For SO2 at high RH, either SO5- (m/z=112 amu) or SO5-.H2O (m/z=130 amu) can be used for SO2 detection without a decrease in sensitivity. For H2SO4 at high RH, it is preferred to detect the ion H2SO4.CO3- because the background signal at 158 amu is small, and a better sensitivity can be achieved.

Salcedo, D.; Villalta, P. W.; Varutbangkul, V.; Wormhoudt, J. C.; Miake-Lye, R. C.; Worsnop, D. R.; Ballenthin, J. O.; Thorn, W. F.; Viggiano, A. A.; Miller, T. M.; Flagan, R. C.; Seinfeld, J. H.

2004-01-01

229

The Leukotriene Receptor Antagonist Zafirlukast Inhibits Sulfur Dioxide-induced Bronchoconstriction in Patients with Asthma  

Microsoft Academic Search

Inhalation of sulfur dioxide (SO 2 ) causes bronchoconstriction in most people with asthma. To exam- ine the role of leukotrienes in this response, the antagonism of SO 2 -induced bronchoconstriction by a single oral dose of the leukotriene receptor antagonist zafirlukast was assessed in a double-blind, pla- cebo-controlled, two-period crossover trial in 12 subjects with mild-to-moderate asthma. Subjects had

STEPHEN C. LAZARUS; HOFER H. WONG; MICHAEL J. WATTS; HOMER A. BOUSHEY; BERNARD J. LAVINS; MARGARET C. MINKWITZ

1997-01-01

230

Hydrogenation of sulfur dioxide to hydrogen sulfide on chromium promoted Fe\\/SiO 2 catalysts  

Microsoft Academic Search

The hydrogenation of sulfur dioxide to hydrogen sulfide was studied over a series of Fe-Si-Cr catalysts in a flow reactor. These catalysts were prepared by co-precipitation of iron nitrate, sodium silicate and chromium nitrate, which had Cr\\/Fe atomic ratios of 00.04 and Si\\/Fe atomic ratios of 01.2. The addition of Cr and Si dramatically improved the SO2 hydrogenation activity of

Kuo-Tseng Li; Yao-Chun Hung; Tien-Ting Ko

2003-01-01

231

The Effects of Sulfur Dioxide Inhalation and Antioxidant Vitamins on Red Blood Cell Lipoperoxidation  

Microsoft Academic Search

An attempt was made to determine whether sulfur dioxide (SO2) inhalation at 10 ppm, 1 hr daily, for 30 days induces oxidant stress and whether vitamin E (40 mg\\/kg) together with vitamin C (200 mg\\/kg), administered intraperitoneally once in every 3 days, can reduce the damage in red blood cell membranes of guinea pigs. Malonyldialdehyde (MDA) levels, osmotic fragility ratios,

O. Etlik; A. Tomur; M. N. Kutman; S. Yorukan; O. Duman

1995-01-01

232

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 (O) and sulfur dioxide (SO). A controlled-environment study involving the speckle-leaf-sensitive cultivar 'Centennial Russet' was conducted to examine the effects of chronic exposure to O and SO on plant growth

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

2009-01-01

233

Effects of Sulfur Dioxide Inhalation on Myocardial Function in Exercise Rat  

Microsoft Academic Search

This paper is to reveal the effect and possible mechanism of sulfur dioxide inhalation on myocardial function in exercise rat. 24 SD rats were divided into 4 groups randomly, rest group(RG), exercise group(EG), SO2 pollution group(SRG) and SO2 pollution exercise group (SEG)( n=6,each group) Rats of SRG and SEG were put into the SO2 pollution environment (10mg\\/m 3 ,1h\\/d,4week), and

Xiao-li Liu; Yan-ru Hu; Jing Qiao; Hong-lei Li

2011-01-01

234

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 (O) and sulfur dioxide (SO). A controlled-environment study involving the speckle-leaf-sensitive cultivar 'Centennial Russet' was conducted to examine the effects of chronic exposure to O and SO on plant growth

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

1983-01-01

235

Effects of oxalate on Fe-catalyzed photooxidation of dissolved sulfur dioxide in atmospheric water  

Microsoft Academic Search

Fe-catalyzed photochemical oxidation of dissolved sulfur dioxide (SO2), S(IV), in the presence of oxalate has been studied under the conditions typical for acidified atmospheric water. The Fe(III)-catalyzed oxidation of S(IV) is first order with respect to S(IV) concentration in the absence of oxalate. The presence of oxalate strongly inhibits Fe(III)-catalyzed S(IV) oxidation due to the formation of Fe(III)oxalato complexes both

Yuegang Zuo; Jian Zhan

2005-01-01

236

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

237

Automated detection of sulfur dioxide in stack emissions by passive Fourier transform infrared spectrometry  

Microsoft Academic Search

Passive Fourier transform infrared (FT-IR) spectrometry is used in the automated qualitative determination of sulfur dioxide (SO2) in a stack monitoring application. Digital filtering and pattern recognition techniques are optimized and applied to short sections of interferograms in a methodology developed to minimize effects of background variation. Two data sets are investigated that were collected with four similarly configured FT-IR

Frederick W Koehler; Gary W Small; Roger J Combs; Robert B Knapp; Robert T Kroutil

2001-01-01

238

Collection of Atmospheric Sulfur Dioxide on Impregnated Fiberglass Filters and Colorimetric Measurement  

Microsoft Academic Search

A specific technique for the collection and measurement of atmospheric sulfur dioxide is described in detail. Sampling is performed by aspiring polluted air through a zinc-acetate-impregnated filter. The polluted zinc acetate is extracted from the filter with a 1.0M zinc-acetate solution. The zinc sulfite formed in the solution resulting from the atmospheric SO2 sampling is later measured colorimetrically as a

Andr M. Chamberland; Pierre Bourbon; Robert Malbosc

1973-01-01

239

ION CHROMATOGRAPHIC MEASUREMENT OF FLUORIDE AND SULFUR DIOXIDE IN SAMPLES COLLECTED AT ALUMINUM SMELTERS  

Microsoft Academic Search

Measurement of airborne fluoride and sulfur dioxide in aluminum smelting plants is important for both industrial hygiene and environmental reasons. The traditional analytical techniques employed have been ion-selective electrodes (ISE) for fluoride and barium\\/thorin titration for SO2. In this study, ion chromatography (IC) was evaluated as a substitute for these two techniques. Dust for particulate fluoride was collected on membrane

D. R. Balya

1991-01-01

240

Removal of sulfur dioxide and formation of sulfate aerosol in Tokyo  

Microsoft Academic Search

Ground-based in situ measurements of sulfur dioxide (SO2) and submicron sulfate aerosol (SO4 2-) together with carbon monoxide (CO) were conducted at an urban site in Tokyo, Japan from spring 2003 to winter 2004. The observed concentrations of SO2 were affected dominantly by anthropogenic emissions (for example, manufacturing industries) in source areas, while small fraction of the data (<30%) was

T. Miyakawa; N. Takegawa; Y. Kondo

2007-01-01

241

Evaluation of satellite derived sulfur dioxide measurements for volcano monitoring during the 2009 Redoubt eruption (Invited)  

Microsoft Academic Search

Changes in sulfur dioxide (SO2) emissions frequently precede volcanic eruptions, thus regular monitoring of volcanic SO2 emissions may facilitate more accurate eruption forecasting. Recent advancements in detection capabilities by both ultraviolet and infrared satellite sensors have made satellite remote sensing a viable tool for monitoring SO2 emissions during volcanic unrest; however, the extent to which satellite-generated SO2 data concur with

T. M. Lopez; S. A. Carn; P. Webley; M. A. Pfeffer; M. P. Doukas; P. J. Kelly; C. A. Werner; F. Prata; D. J. Schneider; C. F. Cahill

2009-01-01

242

Long-range transport of sulfur dioxide in the central Pacific  

Microsoft Academic Search

(1) Long-range transport of sulfur dioxide (SO2) from east Asia to the central North Pacific troposphere was observed on transit flights during the NASA Transport and Chemical Evolution over the Pacific mission. A series of SO2-enhanced layers above the boundary layer was observed during these flights. The significant features included enhanced SO2 layers associated with low water vapor and low

Fang Huang Tu; Donald C. Thornton; Alan R. Bandy; Gregory R. Carmichael; Youhua Tang; K. Lee Thornhill; Glenn W. Sachse; Donald R. Blake

2004-01-01

243

Long-range transport of sulfur dioxide in the central Pacific  

Microsoft Academic Search

Long-range transport of sulfur dioxide (SO2) from east Asia to the central North Pacific troposphere was observed on transit flights during the NASA Transport and Chemical Evolution over the Pacific mission. A series of SO2-enhanced layers above the boundary layer was observed during these flights. The significant features included enhanced SO2 layers associated with low water vapor and low turbulence

Fang Huang Tu; Donald C. Thornton; Alan R. Bandy; Gregory R. Carmichael; Youhua Tang; K. Lee Thornhill; Glenn W. Sachse; Donald R. Blake

2004-01-01

244

Removal of sulfur dioxide and formation of sulfate aerosol in Tokyo  

Microsoft Academic Search

Ground-based in situ measurements of sulfur dioxide (SO2) and submicron sulfate aerosol (SO42?) together with carbon monoxide (CO) were conducted at an urban site in Tokyo, Japan from spring 2003 to winter 2004. The observed concentrations of SO2 were affected dominantly by anthropogenic emissions (for example, manufacturing industries) in source areas, while small fraction of the data (<30%) was affected

T. Miyakawa; N. Takegawa; Y. Kondo

2007-01-01

245

Modeling and measurement of sulfur dioxide absorption rate in a laminar falling film reactor  

Microsoft Academic Search

A kinetic study of sulfur dioxide absorption in a laminar falling film reactor is presented. A theoretical study is carried out taking into account mass transfer with chemical reaction in the liquid phase and parabolic velocity profiles in both phases. The transport equations are solved by a RungeKuttaMerson integration and a NewtonRaphson iteration method. The experimental study consists of measurements

M. H. H. Van Dam; J.-P. Corriou; N. Midoux; A.-S. Lamine; C. Roizard

1999-01-01

246

Relationships Between Sulfur Dioxide Concentration Determined By the West-Gaeke and Electroconductivity Methods  

Microsoft Academic Search

Sulfur dioxide concentrations in the atmosphere are commonly determined by the West-Gaeke and electro-conductivity methods. As a part of the United States-Japan Cooperative Air Pollution Measurement Studies, parallel sampling with a 24-hr bubbler, a 1-hr bubbler, and an electroconductivity instrument was conducted in Kawasaki, Japan, between Jan. 12 and Mar. 25 and between Aug. 19 and Sept. 30, 1966. These

Motoji Terabe; Sadao Oomlchi; F. B. Benson; V. A. Newill; J. E. Thompson

1967-01-01

247

Geographical Distributions of Temperature Change for Scenarios of Greenhouse Gas and Sulfur Dioxide Emissions  

Microsoft Academic Search

Time-dependent geographical distributions of surfaceair temperature change relative to year 2000 are constructed for four scenarios of greenhouse gas (GHG) and sulfur dioxide (SO2) emissions, and are compared to the IS92a scenario. The four new scenarios have been developed by four different modeling teams. The four scenarios are noninterventionist, in that they do not include abatement of GHG emissions for

Michael E. Schlesinger; Sergey Malyshev; Eugene V. Rozanov; Fanglin Yang; Natalia G. Andronova; Bert De Vries; Arnulf Grbler; Kejun Jiang; Toshihiko Masui; Tsuneyuki Morita; Joyce Penner; William Pepper; Alexei Sankovski; Yang Zhang

2000-01-01

248

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 (312 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

249

A rapid method for the determination of sulfur dioxide in sulfited pre-peeled potatoes  

Microsoft Academic Search

SummaryA simple method has been developed for determining the sulfur dioxide content of sulfited, fresh potatoes. A 100 gram sample\\u000a of potato is homogenized in a buffer solution at pH 4.4, which was found to reduce the oxidation of the sulfite to a negligible\\u000a amount during the extraction and subsequent filtration. An aliquot of the filtered extract is then titrated

L. R. Ross; R. H. Treadway

1960-01-01

250

Satellite Monitoring of Volcanic Sulfur Dioxide Emissions for Early Warning of Volcanic Hazards  

Microsoft Academic Search

Satellite-based remote sensing measurements of volcanic sulfur dioxide (SO2) provide critical information for reducing volcanic hazards. This paper describes the use of SO2 measurements from the thermal infrared sounder IASI and the UV-VIS instrument GOME-2 in services related to aviation hazard and early warning of volcanic unrest. The high sensitivity of both instruments to SO2 allows the detection and global

Meike Rix; Pieter Valks; Nan Hao; Jos van Geffen; Catherine Clerbaux; Lieven Clarisse; Pierre-Franois Coheur; Thilo Erbertseder; Walt Zimmer; Sunil Emmadi

2009-01-01

251

Prenatal Sulfur Dioxide Exposure Induces Changes in the Behavior of Adult Male Mice During Agonistic Encounters  

Microsoft Academic Search

Sulfur dioxide (SO2) is one of the most important pollutants of the western countries, responsible for several cardiopulmonary diseases in humans. SO2 affects both young and adult people, causing low work productivity with social and economical costs extremely high for the communities. To test whether or not SO2 produces changes in social and\\/or agonistic behavior of laboratory animals, outbred CD-1

Marco Fiore; Simona Petruzzi; Giacomo DellOmo; Enrico Alleva

1998-01-01

252

Sulfur Dioxide Emissions and Market Effects under the Clean Air Act Acid Rain Program  

Microsoft Academic Search

The Clean Air Act Amendments of 1990 (CAAA90) established a national program to control sulfur dioxide (SO2) emissions from electricity generation. CAAA90's market-based approach includes trading and banking of Soumissions allowances. We analyzed data describing electric utility SO2 emissions in 1995, the first year of the program's Phase I, and market effects over the 1990-1995 period. Fuel switching and flue-gas

Carl E. Zipper; Leonard Gilroy

1998-01-01

253

In-situ sulfur dioxide capture by flame-injected sorbents  

Microsoft Academic Search

The author has burned 52 coal-volatiles-like (doped with sulfur dioxide) float flames that simulate well the early stages of coal combustion, as well as provided good times\\/temperature resolution. The experimental and theoretical research program of SO capture lead to the following findings. (1) Significant (20-50%) SO capture occurs rapidly (2.5 milliseconds) in the early zones of coal volatiles-like flames. (2)

1985-01-01

254

Bonding of eta/sup 2/-sulfur dioxide: structures of tricarbonyl(1,10-phenanthroline) (eta/sup 2/-sulfur dioxide)molybdenum(0) and dicarbonyl(2,2'-bipyridyl)bis(eta/sup 2/-sulfur dioxide)molybedenum(0)  

SciTech Connect

The structures of the title complexes have been determined by X-ray diffraction techniques. Tricarbonyl(1,10-phenanthroline)(eta/sup 2/-sulfur dioxide)molybdenum(0) crystallizes in the space group C2/m with cell constants of a = 19.206 (5) A, b = 12.695 (2) A, c = 8.025 (1) A, ..beta.. = 129.00 (5)/sup 0/ and refines to an unweighted R value of 3.4% on the basis of 945 observations. Dicarbonyl(2,2'-bipyridyl)bis(eta/sup 2/-sulfur dioxide)molybdenum(0) crystallizes in P anti l with cell parameters of a = 11.070 (5) A, b = 7.096 (1) A, c = 11.043 (6) A, ..cap alpha.. = 111.97 (2)/sup 0/, ..beta.. = 98.25 (4)/sup 0/, and ..gamma.. = 100.02 (3)/sup 0/. Full-matrix refinemwnts based on 1190 observations resulted in an R value of 3.0%. Both structures contain eta/sup 2/-type Mo-SO/sub 2/ linkages. The first of these complexes exhibits Mo-O and Mo-S distances of 2.223 (7) and 2.532 (3) A with dihedral angle between the SO/sub 2/ and c-MSO/sub M/ planes of 108.1/sup 0/. The SO/sub 2/ is trans to a carbonyl. The corresponding distances in the trans-(SO/sub 2/)/sub 2/ complex are 2.113 (4) and 2.109 (4) A for Mo-O and 2.496 (3) A for both Mo-S distances with dihedral angles of 103.6 and 103.3/sup 0/, respectively. The two bound S-O bonds are perpendicular to one another and are in the same plane with a cis carbonyl. The eta/sup 2/-SO/sub 2/ bonding is discussed in relationship to these structures.

Kubas, G.J,; Ryan, R.R.; McCarty, V.

1980-10-01

255

SOA FORMATION FROM THE IRRADIATION OF A-PINENE-NOX IN THE ABSENCE AND PRESENCE OF SULFUR DIOXIDE  

EPA Science Inventory

Sulfur dioxide (SO2) is an important constituent in the polluted atmosphere. It is emitted from combustion sources using fuels that contain sulfur. Emissions of SO2 in the United States were reportedly 17 Tg in 1996 with most coming from coal and petroleum combustion. The pr...

256

Incorporation of sulfur dioxide into snow and depositing ice  

SciTech Connect

Depth profiles of S(IV) and S(VI) in snow exposed to 20-140 ppbv SO/sub 2/ for 6 to 12 hours were determined in 48 laboratory experiments. Surface deposition velocity (V/sub d/) averaged 0.06 cm s/sup -1/. Well-metamorphosed snow, longer run times, higher SO/sub 2/ concentrations and colder snow were associated with lower values of V/sub d/, and vice versa. Melting followed by draining increased v/sub d/ greatly (0.14 cm s/sup -1/). Any effect of ozone on SO/sub 2/ v/sub d/ was undetectable. Most sulfur in the snow was a S(VI), even without added ozone, indicating the presence of other oxidants, especially in new snow. The deposition of SO/sub 2/ into a snowpack is modeled as an aqueous system, where the liquid water is considered to be present on snow grain surfaces. Gas transport into the snow, air-water partitioning,and aqueous-phase reactions are explicitly considered. Experiments were also conducted on the incorporation of SO/sub 2/ into ice depositing from the vapor at -7 and -15/sup 0/C. Remarkably, SO/sub 2/ is captured in deposited ice at concentrations comparable to Henry's Law equilibrium with water at 0/sup 0/C. Ozone and HCHO appear to inhibit, not enhance, SO/sub 2/ capture. An aqueous-film model accounting for the capture of SO/sub 2/ by depositing ice was developed.

Valdez, M.P.

1987-01-01

257

Excitation band dependence of sulfur isotope mass-independent fractionation during photochemistry of sulfur dioxide using broadband light sources  

NASA Astrophysics Data System (ADS)

Ultraviolet photolysis of sulfur dioxide (SO2) is hypothesized to be the source of the sulfur isotope mass-independent fractionation (S-MIF) observed in Archean sulfate and sulfide minerals and modern stratospheric sulfate aerosols. A series of photochemical experiments were performed to examine the excitation band dependence of S-MIF during the photochemistry of SO2 under broadband light sources (a xenon arc lamp and a deuterium arc lamp). Optical filters (200 35 nm bandpass and 250 nm longpass filters) were used to separately access two different excitation bands of SO2 in the 190-220 nm and the 250-330 nm absorption regions, respectively.UV irradiation of SO2 in the 190-220 nm and 250-330 nm regions both produced elemental sulfur (S0) and sulfur trioxide (SO3) as end products but yielded very different sulfur isotope signatures. The elemental sulfur products from direct photolysis in the 190-220 nm region were characterized by high ?34S values (154.7-212.0), modest ?33S anomalies of 21 3, and relatively constant 33? (=ln(?33S + 1)/ln(?34S + 1)) values of 0.64 0.3, all with respect to the initial SO2. Photoexcitation in the 250-330 nm region produced elemental sulfur with ?34S values of 7.7-29.1 and ?33S values of 15.0 1.6. In both excitation regions, the SO3 products were mass dependently fractionated relative to the SO2 reservoir. The two different absorption regions produced contrasting ?36S/?33S signatures in the elemental sulfur products, with ?36S/?33S = -1.9 0.3 and 0.64 0.3 for the 190-220 nm and 250-330 nm bands, respectively.Our results provide several critical constraints on the origin of the S-MIF signatures observed in modern stratospheric aerosols and in the Archean geological record. A lack of S-MIF in the sulfate product and positive ?36S/?33S ratios for the elemental sulfur from SO2 photo-oxidation demonstrate that photoexcitation in the 250-330 nm region is not a likely source for the S-MIF observed in modern stratospheric aerosols. Large ?34S fractionation, 33? values, and ?36S/?33S ratios observed for the 190-220 nm band are qualitatively consistent with predictions from synthetic isotopologue-specific cross sections. These isotope patterns, however, are not compatible with the Archean rock record. We explore the possibility that S-MIF from both the 190 to 220 nm and the 250 to 330 nm absorption bands could have contributed to the Archean S-MIF signatures.

Whitehill, Andrew R.; Ono, Shuhei

2012-10-01

258

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

NASA Astrophysics Data System (ADS)

A remote sensor for measuring on-road vehicles passing the sensor in real time is described. This sensor expands upon previous technology that measured carbon monoxide, carbon dioxide, and exhaust hydrocarbons in the IR and nitric oxide in the UV. The design adds the capability to measure nitrogen dioxide in the UV with one spectrometer and to measure SO2 and NH3 along with NO in a second UV spectrometer. With these units operating side by side, the major mobile source precursors to secondary aerosol production can be measured simultaneously and in real time. Detection limits for NO2, SO2, and NH3 are 1.2, 0.72, and 0.78 g pollutant per kilogram of fuel, respectively.

Burgard, Daniel A.; Dalton, Thomas R.; Bishop, Gary A.; Starkey, John R.; Stedman, Donald H.

2006-01-01

259

Spatial Distribution of Carbon Dioxide, Hydrogen Peroxide, and Sulfuric Acid on Europa  

NASA Astrophysics Data System (ADS)

The distributions of CO2, H2O2, and hydrated H2SO4 were investigated from 80 W to 300 W longitude using infrared spectral maps from Galileo NIMS. Europa's 4.25-micrometer carbon dioxide band (Smythe et al., LPSC, 1998) is present in the equatorial region of the leading hemisphere but is absent on the trailing hemisphere. Band strength maps show a non-uniform distribution that correlates with diffuse dark regions on the leading hemisphere. Since impacts and meteoritic infall are greatest on this hemisphere, Europa's CO2 is suggested to be radiolytically produced in dark carbonaceous meteoritic deposits. Hydrogen peroxide, which is formed on Europa in the radiolysis of water ice (Carlson et al., Science 283, 2062, 1999), exhibits an absorption band at 3.5 micrometers. This absorption is present in equatorial and mid latitudes on Europa's leading hemisphere. The presence of H2O2 on the leading side and its non-detection on the trailing hemisphere may be due to the greater abundance of pure ice on the leading side compared to the trailing hemisphere. Hemispherical differences in chemical impurities and the resulting radiation chemistry pathways may also be involved. Europa's hydrated material, suggested to be sulfuric acid hydrate that is radiolytically produced from sulfur in a continuous cycle (Carlson, Johnson, and Anderson, Science 286, 97, 1999), exhibits a trailing side enhancement. The global distribution is consistent with an Iogenic sulfur ion implantation. High-resolution maps show patterns that correlate with geological features. Sublimation of water during diapiric heating can enhance sulfur and sulfuric acid concentrations and produce such correlation. Endogenic sources of sulfurous material may also contribute. This work was supported by NASA's Planetary Geology and Geophysics Program.

Carlson, R. W.

2001-11-01

260

Effects of breathing sulfur dioxide and an acidic sulfate aerosol during exercise on selected pulmonary function measurements  

SciTech Connect

This study was undertaken to determine the effects of ambient air, acidic sulfate aerosol, sulfur dioxide, and the combination of sulfur dioxide and aerosol on selected pulmonary function measurements after 20 minutes of exercise at 75%-80% maximal heart rate in a hot (36-19/sup 0/C) and humid (70-90% RH) environment. Six male subjects between the ages 26 and 33 years with no pre-existing pulmonary or cardiovascular problems rode a stationary bicycle for 20 minutes during each exposure condition at a workload pre-set to assure that each subject would attain an average minute ventilation of 50-60 1/min (BTPS). Exposure to 2.5 ppm sulfur dioxide alone led to a significant lowering of FVC, FEV1, and FEF50. Exposure to sulfur dioxide plus aerosol led to a significant decrease of FVC. Baseline comparisons reflected a significant decline in FVC, FEV1, FEF25, FEF50, FEF75, and FEF25-75 between the pre-ambient and post-exposure. This decline suggests a residual effect of the air pollutant exposures. Significant differences were also observed between the pre-aerosol and pre-sulfur dioxide exposures for FVC, FEV1, FEF50, and FEF25-75.

Jones, D.L.

1985-01-01

261

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 (19992000) 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

262

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

263

Experimental study on the temperature dependence of ultraviolet absorption cross-sections of sulfur dioxide  

Microsoft Academic Search

The photoabsorption cross-sections of sulfur dioxide were measured in the spectral regions of 200230 nm and 275315 nm at\\u000a 298415 K, using a grating monochromator with a resolution of 0.2 nm. The discrete absorption cross-section is directly correlated\\u000a with the number of quantum excited from the base state. The absorption cross-sections at the peaks of discrete bands decreased\\u000a linearly with

Shiliang Zhang; Jie Zhou; Xiaohu Chen

2008-01-01

264

Magmatic vapor source for sulfur dioxide released during volcanic eruptions: Evidence from Mount Pinatubo  

SciTech Connect

Sulfur dioxide (SO[sub 2]) released by the explosive eruption of Mount Pinatubo of 15 June 1991 had an impact on climate and stratospheric ozone. The total mass of SO[sub 2] released was much greater than the amount dissolved in the magma before the eruption, and thus an additional source for the excess SO[sub 2] is required. Infrared spectroscopic analyses of dissolved water and carbon dioxide in glass inclusions from quartz phenocrysts demonstrate that before eruption the magma contained a separate, SO[sub 2]-bearing vapor phase. Data for gas emissions from other volcanoes in subduction-related arcs suggest that preeruptive magmatic vapor is a major source of the SO[sub 2] that is released during many volcanic eruptions.

Wallace, P.J. (Univ. of Chicago, IL (United States)); Gerlach, T.M. (Geological Survey, Vancouver, WA (United States))

1994-07-22

265

Synthesis of dimethyl carbonate and glycols from carbon dioxide, epoxides, and methanol using heterogeneous basic metal oxide catalysts with high activity and selectivity  

Microsoft Academic Search

This paper gives a comprehensive report on a two-step synthesis of dimethyl carbonate (DMC) from epoxides, carbon dioxide and methanol using various basic metal oxide catalysts. The first step is the reaction of ethylene oxide or propylene oxide with CO2 to form the corresponding cyclic carbonates, and the second step is the transesterification reaction of the cyclic carbonates with methanol

Bhalchandra M Bhanage; Shin-ichiro Fujita; Yutaka Ikushima; Masahiko Arai

2001-01-01

266

Sulfur dioxide and nitrogen dioxide adsorption on zinc oxide and zirconium hydroxide nanoparticles and the effect on photoluminescence  

NASA Astrophysics Data System (ADS)

Nanoparticulate zinc oxide and micron-size zirconium hydroxide powders have been exposed to sulfur dioxide and nitrogen dioxide by flowing the gases, diluted with nitrogen, over powder samples. X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and thermogravimetric analysis (TGA) indicate strongly bound, chemisorbed SO3 and NO3 surface species. Two pre-treatments of the nanoparticulate ZnO samples prior to gas exposure have been investigated: (1) drying overnight in a vacuum oven and (2) hydrating the samples by placing them overnight in water-saturated air. A dramatic difference in reactivity of ZnO is observed, with approximately two-fold and ten-fold greater uptake of NO2 and SO2, respectively, measured by XPS for the hydrated samples relative to the dried ones. Transmission electron microscopy (TEM) demonstrates that the greater uptake arises from a morphology change in the case of the hydrated samples. For zirconium hydroxide, no morphology change is observed for hydrated samples, and SO4 (ads), in addition to SO3 (ads), is indicated by XPS. ZnO and Zr(OH)4 both exhibit photoluminescence (PL) spectra, with peak intensities that change dramatically due to hydration and subsequent exposure to SO2 and NO2 gases. Dosing of the powders with these gases effectively reverts the PL spectra to those corresponding to less hydration.

Singh, Jagdeep; Mukherjee, Anupama; Sengupta, Sandip K.; Im, Jisun; Peterson, Gregory W.; Whitten, James E.

2012-05-01

267

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, ...

268

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

269

New analytical reagents for the determination of sulfur dioxide and carbon monoxide  

SciTech Connect

Four solid reagent methods were developed for the determination of sulfur dioxide in air, and one method was developed to measure carbon monoxide. When applied to filter paper with acetamide as the humectant and 4-phenylcyclohexanone as a bisulfite absorbent, oxohydroxybis(8-hydroxyquinolinyl-) vanadium (V) changes from yellow to black in the presence of sulfur dioxide. The three other methods, also on a filter paper support, utilized the reduction of bromate to bromine which then changed 3-,3'-, 5-,5'-tetramethylbenzidine from yellow to blue, phenothiazine from white to green, and 4-dimethylamino-4'-,4/double prime/-dimethoxytriphenylmethanol from colorless to red-purple. Quantitative measurements were made by reflectance spectroscopy. The method for carbon monoxide involved the use of tetrakis (acetamide-) Pd(II) ditetrafluoroborate, sodium iodate, and leuco crystal violet all together on a filter paper support. Carbon monoxide reduced the Pd(II)-acetamide complex to metallic palladium. The metallic palladium then reduced iodate to hypoiodous acid, HOI, which, in turn, oxidized leuco crystal violet to crystal violet. The crystal violet color was then measured by reflectance.

Trump, E.L.

1987-01-01

270

Influence of a large sulfur dioxide point source on mesoscale rainwater chemistry  

SciTech Connect

We are measuring the spatial and temporal variations in rainwater chemical composition at forty ground-level sites near (within 100 km) a large sulfur dioxide point source (a copper smelter). Simultaneous measurement of particulate chemical composition in the surrounding air both at ground level and in the plume as well as knowledge of sulfur dioxide emissions as a function of time allow us to estimate the contribution of this source to the total wet deposition downwind. Similar measurements of the chemical composition of rain and air after closure of this source will allow us to verify our estimates of the source's contribution to downwind rainwater chemistry. The closure of this relatively isolated source in an area with a clean background provides a unique opportunity to examine these 'source-receptor' relationships and the models used to predict them. A key assumption in this work is that the variability in rainwater chemical composition due to both sampling and analysis procedures as well as meteorology of selected storms is small when compared with the spatial variability due to the smelter influence. Results to date indicate that is the case. To the extent that this source imposed variability is important for a number of chemical species, it should be possible to test a variety of deterministic and multivariate statistical models of precipitation scavenging and wet deposition.

Alkezweeny, A.J.; Laulainen, N.S.

1985-08-01

271

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

272

Effect of metaproterenol sulfate on mild asthmatics' response to sulfur dioxide exposure and exercise  

SciTech Connect

Twenty asthmatic volunteers, most with mild disease, underwent dose-response studies with sulfur dioxide (SO2) under three pretreatment conditions: (1) drug (metaproterenol sulfate in aerosolized saline solution), (2) placebo (aerosolized saline only), and (3) no pretreatment. Sulfur dioxide exposure concentrations were 0.0, 0.3, and 0.6 ppm. Experimental conditions were presented in random order at 1-wk intervals. Exposures lasted 10 min with heavy continuous exercise. Lung function was measured at baseline, after pretreatment (immediately pre-exposure), immediately post-exposure, and during a 2-hr follow-up. Subjects could elect to take bronchodilators during follow-up. Symptoms were monitored before, during, and for 1 wk after exposure. With no pretreatment, subjects exhibited typical exercise-induced bronchospasm at 0.0 ppm, slightly increased responses at 0.3 ppm, and more marked increases at 0.6 ppm. Seven subjects took bronchodilator after 0.6-ppm exposures, compared to 2 at lower concentrations. Within 30 min post-exposure, most subjects' symptoms and lung function had returned to near pre-exposure levels. A similar sequence was observed when subjects received placebo. Drug pretreatment improved lung function relative to baseline, prevented bronchoconstrictive responses at 0.0 and 0.3 ppm, and greatly mitigated responses at 0.6 ppm. Thus, typical bronchodilator usage by asthmatics is likely to reduce their response to ambient SO2 pollution.

Linn, W.S.; Avol, E.L.; Shamoo, D.A.; Peng, R.C.; Spier, C.E.; Smith, M.N.; Hackney, J.D.

1988-11-01

273

Productivity of field-grown soybeans exposed to acid rain and sulfur dioxide alone and in combination  

Microsoft Academic Search

Sulfur dioxide (SO)-fumigated and unfumigated field plots of soybeans (Glycine max cv. Wells) were exposed to acid (pH 3.1) or control (pH approx.5.3) precipitation simulants to determine effects on growth and productivity. The precipitation simulants were applied at approximately 5-day intervals in July and August with a total of 3.4 cm applied in 1977 and 4.5 cm in 1978. Sulfur

P. M. Irving; J. E. Miller

1981-01-01

274

New instrumentation for the detection of sulfur dioxide in the remote atmosphere  

NASA Astrophysics Data System (ADS)

Sulfur gases are an important chemical component of the atmosphere. Gaseous sulfur compounds effect the acidity of rainwater and are important precursors to aerosol particles which affect public health, climate and visibility of scenic vistas such as the Grand Canyon. Sulfate aerosols are also known to participate in ozone catalysis in the stratosphere. A vast majority of the gaseous sulfur cycling through the atmosphere will exist as sulfur dioxide (SO2) at some time during its atmospheric lifetime. Since SO 2 is a primary component of the atmospheric sulfur cycle, quality measurements of this gas are important to understanding the cycling of sulfur through the atmosphere. The mixing ratio of SO2 in the atmosphere can be as low as a few 10's of parts-per- trillion by volume (pptv) in unpolluted areas and as high as 100's of parts-per-billion by volume (ppbv) near industrial centers. Obtaining SO2 measurements with mixing ratios that can differ by 105 in magnitude is a difficult task, especially for mixing ratios less than a few hundred pptv. The Diffusion Denuder/Sulfur Chemiluminescence Detector (DD/SCD) was developed further and tested in a rigorously blind comparison under controlled laboratory conditions. The DD/SCD exhibited excellent sensitivity and little-to- no interference from other trace gases. The DD/SCD performance was comparable to that of other state-of-the- art instruments developed for measuring SO 2 in the remote atmosphere. The Continuous SO2 Detector was developed to overcome the limitation of long sampling times (4 to 90 minutes) inherent in the DD/SCD and other state-of-the- art techniques. The Continuous SO2 Detector (CSD) was developed based on the design of the DD/SCD, but has been optimized for sensitive, high-time resolved measurements of SO2 in air. Sensitive, high- time resolved measurements would be beneficial for studying atmospheric SO2 over large geographical areas from a moving sampling platform such as an aircraft. The current prototype of the CSD is capable of measuring SO2 at mixing ratios of less than 100 pptv on the order of seconds. The DD/SCD, CSD and an automated, computer controlled dynamic dilution system described in this thesis represent a suite of instruments for the measurement of SO2 in the remote atmosphere.

Nicks, Dennis Keith, Jr.

275

Sulfur K-Edge X-Ray Absorption Spectra for Dimethyl Sulfoxide in the Solvated Thallium(III), Indium(III0, Gallium(III) An Aluminum(III) Ions  

SciTech Connect

The sulfur K-edge x-ray absorption near edge spectra (XANES) of the hexakis(dimethyl sulfoxide) solvated trivalent group 13 ions, Al, Ga, In and Tl, in the solid state show larger splitting and different intensity distribution of the main sulfur 1s electronic excitations than for the uncoordinated dimethyl sulfoxide molecule. The transitions have been interpreted by density functional calculations, and the increased splitting is shown to be an effect of metal-oxygen orbital interactions in the bonds to the oxygen coordinated dimethyl sulfoxide ligand.

Damian, E.; Jalilehvand, F.; Abbasi, A.; Pettersson, L.G.M.; Sandstrom, M.; /SLAC, SSRL

2006-10-25

276

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 ...

277

Water, sulfur dioxide and nitric acid adsorption on calcium carbonate: a transmission and ATR-FTIR study.  

PubMed

Calcium carbonate (CaCO3) is a reactive component of mineral dust aerosol as well as buildings, statues and monuments. In this study, attenuated total reflection (ATR) and transmission Fourier transform infrared spectroscopy (FTIR) have been used to study the uptake of water, sulfur dioxide and nitric acid on CaCO3 particles at 296 K. Under atmospheric conditions, CaCO3 particles are terminated by a Ca(OH)(CO3H) surface layer. In the presence of water vapor between 5 and 95% relative humidity (RH), water molecularly adsorbs on the Ca(OH)(CO3H) surface resulting in the formation of an adsorbed thin water film. The adsorbed water film assists in the enhanced uptake of sulfur dioxide and nitric acid on CaCO3 in several ways. Under dry conditions (near 0% RH), sulfur dioxide and nitric acid react with the Ca(OH)(CO3H) surface to form adsorbed carbonic acid (H2CO3) along with sulfite and nitrate, respectively. Adsorbed carbonic acid is stable on the surface under vacuum conditions. Once the surface saturates with a carbonic acid capping layer, there is no additional uptake of gas-phase sulfur dioxide and nitric acid. However, upon adsorption of water, carbonic acid dissociates to form gaseous carbon dioxide and there is further uptake of sulfur dioxide and nitric acid. In addition, adsorbed water increases the mobility of the ions at the surface and enhances uptake of SO2 and HNO3. In the presence of adsorbed water, CaSO3 forms islands of a crystalline hydrate whereas Ca(NO3)2 forms a deliquescent layer or micropuddles. Thus adsorbed water plays an important and multi-faceted role in the uptake of pollutant gases on CaCO3. PMID:19791344

Al-Hosney, H A; Grassian, V H

2005-03-21

278

Upper Water Column Dimethylated Sulfur Biogeochemical Cycling in the Sargasso Sea - Assessing the Oceanic DMS Source  

NASA Astrophysics Data System (ADS)

Once ventilated to the atmosphere, the oxidation products of biologically produced DMS are non sea salt sulfate and methane sulfonate aerosols which potentially exert considerable control on the global climate via alterations in radiative properties, acid-base chemistry, halogen cycles, and aerosol iron availability. The most significant obstacle to assessing and quantifying any associated climate feedbacks, beyond uncertainties associated with flux parameterizations, is the lack of understanding of the mechanisms that regulate oceanic near surface DMS concentrations. To assess the seasonal variability in the oceanic DMS source, monthly vertical profiles of DMS and particulate and dissolved DMSP (DMSPp and DMSPd) concentrations and biogeochemical cycling rates were sampled in the Sargasso Sea commencing in September 2005 at the Bermuda Atlantic Time-series Study site (BATS). Clear seasonal cycles are evident for DMS and DMSPp concentrations, although they are poorly correlated to available biomass indicators. DMSPd was consistently low and did not exhibit a clear seasonality. Biological DMS consumption is characterized by seasonal minima and maxima observed above and below the mixed layer depth respectively during strong summertime stratification. No clear seasonal cycles are evident in microbial DMSPd consumption rates or DMS yield but they vary within a relatively narrow range. Modeled phytoplankton DMS production rates are extremely large, negatively correlated to phytoplankton biomass indicators, and peak in the summer confirming that DMS concentrations and turnover processes are also affected by the physical dynamics of the surface mixed layer and by meteorological forcing such as total solar radiation, UV radiation, and wind speed. This research provides the first time-series of open-ocean organic sulfur cycling rates which will not only refine our understanding of the controlling mechanisms but will also serve as a basis for future oceanic and atmospheric modeling endeavors.

Toole, D. A.; Dacey, J. W.; Bates, N. R.; Levine, N. M.; Neeley, A.

2008-12-01

279

Process for improving a gas containing a minor amount of sulfur dioxide impurity and producing a hydrogen sulfide-rich gas  

Microsoft Academic Search

A process is provided for adsorbing sulfur dioxide impurity from an impure gas and producing a hydrogen sulfide-rich gas. In the process, a first adsorbate containing oxidized sulfur is produced by contacting the impure gas with an adsorbent comprising a composite of an alumina support and sodium and vanadium oxides. A second adsorbate containing reduced sulfur is produced by contacting

Blanton

1980-01-01

280

Alkali metal-sulfur dioxide complexes stabilized by halogenated closo-dodecaborate anions.  

PubMed

The alkali metal salts (M = Li, Na, K, Rb, Cs) of the perchlorinated closo-dodecaborate [B(12)Cl(12)](2-) were prepared by reaction of [NEt(3)H](2)[B(12)Cl(12)] with the corresponding alkali metal hydroxide. Crystallization of M(2)[B(12)Cl(12)] from liquid sulfur dioxide gave the sulfur dioxide complexes [Li(2)(SO(2))(8)][B(12)Cl(12)], Na(2)[B(12)Cl(12)].4SO(2), K(2)[B(12)Cl(12)].8SO(2), Rb(2)[B(12)Cl(12)].4SO(2), and Cs(2)[B(12)Cl(12)].SO(2), which were characterized by single crystal X-ray diffraction. In this work structurally characterized SO(2) complexes of the alkali metal cations K(+) and Rb(+) are reported for the first time. The structure of [Li(2)(SO(2))(8)][B(12)Cl(12)] contains discrete [Li(2)(SO(2))(8)](2+) dications and [B(12)Cl(12)](2-) dianions. Born-Haber cycles based on quantum chemical calculations and estimations of lattice enthalpies for the solid state explain the stability of the discrete dication [Li(2)(SO(2))(8)](2+) in the solid state. Heavier alkali metals form three-dimensional networks containing metal-anion and metal-sulfur dioxide contacts. The crystal structures of Na(2)[B(12)Br(12)].8SO(2) and Na(2)[B(12)I(12)].8SO(2) were determined to investigate the influence of the halogen substituent on the anion. They contain similar three-dimensional network structures. Na(2)[B(12)Br(12)].8SO(2) is isostructural to K(2)[B(12)Cl(12)].8SO(2). In addition the crystal structures of the complexes Na(2)[B(12)I(12)].8SO(2).H(2)O and Na(2)[B(12)H(12)].6SO(2).2H(2)O, which contain water ligands, are reported as well. A comparison of halogenated dodecaborates [B(12)X(12)](2-) (X = F, Cl, Br, I) based on [small nu, Greek, tilde](N-H) stretching frequencies of the corresponding [Oct(3)NH](2)[B(12)X(12)] (X = F - I) salts shows that the fluorinated anion [B(12)F(12)](2-) is the least basic and the iodinated anion [B(12)I(12)](2-) is the most basic anion in this series. These findings are in agreement with those for the corresponding series of perhalogenated carboranes and are explained by the polarizability of the halogen substituent. PMID:20717610

Derendorf, Janis; Kessler, Mathias; Knapp, Carsten; Rhle, Monika; Schulz, Christoph

2010-08-18

281

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...

282

Acute and chronic sulfur dioxide fumigation of Pi{tilde n}on pine seeds and seedlings: Data compilation  

SciTech Connect

Pi{tilde n}on pine germinating seeds, emergent seedlings, and one-year-old seedlings were exposed to sulfur dioxide under both acute and chronic exposure conditions. These fumigations were conducted in order to determine the potential for damage to pi{tilde n}on pine in southwestern national parks and monuments where there is potential for exposure to elevated sulfur dioxide concentrations from smelters and power plants. Injury was apparent only in acute fumigations of one-year-old seedlings at ambient sulfur dioxide concentrations of greater than 3 ppm. Chronic fumigations were conducted only a ambient concentrations of 0.2 ppm. Pi{tilde n}on pine resistance was evidenced by lack of effect of fumigation on biomass and growth parameters. Growth rate data for both experimental and control seedlings were fit to a linear growth model with a correlation (r{sup 2} = 0.95). The results of this study agree with other data in the literature and indicate that damage from elevated sulfur dioxide concentrations in southwestern national parks and monuments is much more likely for other, more sensitive, species than for pi{tilde n}on pine.

Trujillo, M.L.; Ferenbaugh, R.W.; Gladney, E.S. [Los Alamos National Lab., NM (United States); Bowker, R.G. [Alma Coll., MI (US). Dept. of Biology

1993-09-01

283

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

Microsoft Academic Search

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

La Toya Myles; Tilden P. Meyers; Larry Robinson

2007-01-01

284

Effect of temperature on stability of sulfur dioxide samples collected by the federal reference method. Final report  

Microsoft Academic Search

This report describes an evaluation of the effect of temperature on the stability of samples collected according to the Environmental Protection Agency procedure for measurement of ambient sulfur dioxide. This evaluation was carried out over the range 35 to 278 micrograms per cubic meter of air sampled. Collected samples were found to decay at a critical temperature-dependent rate. The rate

R. G. Fuerst; F. P. Scaringelli; J. H. Margeson

1976-01-01

285

OMI Measurements of Sulfur Dioxide Abundances and Altitudes of the Volcanic Plumes from Eruptions of Okmok and Kasatochi in 2008  

Microsoft Academic Search

Sulfur dioxide (SO2) injected into the atmosphere during volcanic eruptions is soon converted into sulfate aerosols, which promote ozone depletion and affect Earth's radiation balance and climate. The impact of an eruption depends on the amount of sulfate aerosols it produces, their spatial distribution and lifetime in the atmosphere. The sulfate aerosol amount is determined by the amount of SO2

K. Yang; N. A. Krotkov; A. J. Krueger; S. A. Carn; P. K. Bhartia

2008-01-01

286

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

Microsoft Academic Search

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

LaToya Myles; Tilden P Meyers; Larry Robinson

2007-01-01

287

Sulfur dioxide dry deposition on the loess surfacesurface reaction concept for measuring dry deposition flux  

Microsoft Academic Search

As an effort to obtain more extensive data on sulfur dioxide dry deposition in northern China, experiments were carried out in Beijing by trying a new approach to the deposition flux determination. In this approach we determined the flux by a traditional concentration gradient method in the cases where the wind velocity profile conformed to the logarithmic law. In the

Masahiro Utiyama; Tsutomu Fukuyama; Kazuhiko Sakamoto; Hidekazu Ishihara; Atsuyuki Sorimachi; Takeshi Tanonaka; Xuhui Dong; Hao Quan; Wei Wang; Dagang Tang

2005-01-01

288

Abinitio quantum chemical study of the molecular and spectroscopic (infrared and Raman) properties of sulfur dioxide: Comparison with ozone  

Microsoft Academic Search

Using abinitio SCF, singles and doubles configuration interaction (CI-SD), and coupled pair functional (CPF) techniques with basis sets of triple zeta plus two polarization functions quality, the following properties have been computed for sulfur dioxide at its equilibrium geometry: dipole and quadrupole moments, electric field gradients at the nuclei, static and frequency dependent dipole polarizability (at ?=5154 A? and ?=6328

George B. Bacskay; Alistair P. L. Rendell; Noel S. Hush

1988-01-01

289

Industrial Sources Influence Air Concentrations of Hydrogen Sulfide and Sulfur Dioxide in Rural Areas of Western Canada  

Microsoft Academic Search

A survey of monthly average concentrations of sulfur dioxide (SO2) and hydrogen sulfide (H2S) at rural locations in western Canada (provinces of Alberta, British Columbia, and Saskatchewan) was conducted in 2001 2002, as part of an epidemiological study of the effects of oil and gas industry emissions on the health of cattle. Repeated measurements were obtained at some months and

Igor Burstyn; Ambikaipakan Senthilselvan; Hyang-Mi Kim; Nicola M. Cherry; Elise Pietroniro; Cheryl Waldner; George Hidy; Paul Lioy; Herbert McKee; David Mobley; Yasuko Yoshida; Azusa Ito; Masashi Murakami; Takayuki Murakami; Hideharu Fujimoto; Kikuo Takeda; Shigeru Suzuki; Masahiro Hori; Huan Liu; Kebin He; Qidong Wang; Hong Huo; James Lents; Nicole Davis; Nick Nikkila; Changhong Chen; Mauricio Osses; Chunyu He; Thomas Hilber; Michalis Agraniotis; Panagiotis Grammelis; Emmanuel Kakaras; Thomas Glorius; Uwe Becker; Willy Derichs; Hans-Peter Schiffer; Martin Jong; Lucia Torri; Glynis Lough; Charles Christensen; James Schauer; James Tortorelli; Erin Mani; Douglas Lawson; Nigel Clark; Peter Gabele; Aki Virkkula; Timo; Risto Hillamo; Tarja Yli-Tuomi; Anne Hirsikko; Ismo Koponen; Nicholas Doll; John Reisel; Aron Jazcilevich; Alejandro Garca-Fragoso; Agustn Reynoso; Michel Grutter; Ulises Diego-Ayala; Delbert Eatough; Nolan Mangelson; Richard Anderson; Donald Martello; Natalie Pekney; Cliff Davidson; William Modey

2007-01-01

290

Improvement in the capacity and safety of lithium/inorganic electrolyte sulfur dioxide rechargeable cells, phase 2  

NASA Astrophysics Data System (ADS)

The objective was to develop a prototype rechargeable lithium/sulfur dioxide/carbon cell, using practical AA size hardware, in which the electrolyte was to be a sulfur dioxide solution of lithium bromide or thiocyanate, together with a highly soluble cosolute, a second non-lithium salt of the same anion. The cosolute was intended to replace the organic cosolvents familiar from the primary cells, and hopefully, to improve lithium plating efficiency and electrolyte stability during cycling. The primary discharge capacities for AA size cells containing 1.25M CsBr/0.12 M LiBr/SO2 were only about 400mAh, while secondary and subsequent capacities were less than 200 mAh. The rates of solvolysis of bromide and of thiocyanate were exacerbated apparently both by the high anion concentrations and by increased lithium ion concentration. Lithium/sulfur dioxide/carbon rechargeable cells were examined in which the electrolytes were mixtures of tetrachloro aluminate salts in sulfur dioxide, to take advantage of the better performance, but to face the problem of limited capacity. It was determined that the capacity of lithium/bromine soluble positive cells was being limited by the loss of electrical contact between the carbon and the positive electrode current collector. Also, lithium plating efficiency was poor.

Schlaikjer, Carl R.; Jones, Medlinda D.; Johnson, Arden P.; Torkelson, James E.; Vanschalkwijk, Walter

1990-11-01

291

Investigation of an Exceedance of the NAAQS for Sulfur Dioxide Near the Kingston Steam Plant on November 5, 1979.  

National Technical Information Service (NTIS)

The purpose of this report is to examine the physical and environmental circumstances associated with the exceedance of 3-hour and 24-hour NAAQS for sulfur dioxide that occurred on November 5, 1979, near the Kingston Steam Plant in order to assess which s...

1980-01-01

292

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

National Technical Information Service (NTIS)

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...

E. J. Kohout D. J. Miller L. A. Nieves D. S. Rothman C. L. Saricks

1990-01-01

293

Use of gas diffusion membrane electrodes to investigate coordination species in the sulfur dioxide\\/citrate system  

Microsoft Academic Search

The ability of potentiometric, gas-sensing electrodes to reliably monitor free gaseous molecules in solution has been recently demonstrated. A gas such as sulfur dioxide from a dilute sample solution diffuses through a hydrophobic, gas-permeable membrane to an internal filling solution. The latter solution contains a sufficiently large excess of sodium bisulfite, the concentration of which can be considered constant regardless

S. E. Khalafalla; R. H. Jefferson

1978-01-01

294

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

295

Evaluation of Radian's Report, Water Pollution Impact of Controlling Sulfur Dioxide Emissions from Coal-Fired Steam Electric Generators.  

National Technical Information Service (NTIS)

SRI International is pleased to submit the following report, under DOE Master Agreement Number E(04-3)-115, to review, critique, and comment on the draft report entitled Water Pollution Impact of Controlling Sulfur Dioxide Emissions from Coal-Fired Steam ...

S. S. Lee

1978-01-01

296

Limestone treatment for sulfur dioxide removal. (Latest citations from the EI compendex*plus database). Published Search  

SciTech Connect

The bibliography contains citations concerning the use of limestone for the control of sulfur dioxide emmisions in flue gases. The various designs for flue gas desulfurization are discussed, including dry fluidized beds and wet scrubbers. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

NONE

1998-02-01

297

Effects of ozone and sulfur dioxide mixtures on forest vegetation of the southern Sierra Nevada. Final report  

SciTech Connect

In 1981 and 1982, a multidisciplinary study was conducted within a 32-mile zone from Oildale, CA eastward to points in the southern Sierra Nevada. Concentrations of sulfur in pine needles and lichens along transects tended to decrease with increasing elevation. Stable isotope ratios in soils and plant tissue ran counter to expectations because natural isotopic composition at greater distances is similiar to the source area. Recently germinated pine seedlings exposed to ozone and sulfur dioxide mixtures showed significant differences in root dry weight, suggesting that pollutant mixtures may affect seedling establishment. Surveys of the study area showed increased ozone damage to pines between 1977 and 1981. Sulfur dioxide did not appear to be acting jointly with ozone to cause existing injury.

Taylor, O.C.; Miller, P.R.; Page, A.L.; Lund, L.J.

1986-03-01

298

The effect of sulfur dioxide on the response of rabbits to expiratory loads.  

PubMed

The role of slowly adapting pulmonary stretch receptors (PSR) in the reflex control of expiratory duration was investigated in anesthetized, spontaneously breathing rabbits. Graded resistive and elastic loads were applied for single expirations to produce expiratory volume-time curves. The PSR were selectively blocked by administration of 200-400 ppm sulfur dioxide (SO2) to the inspired air of the rabbits. Volume-time curves were generated for pre-treatment, SO2 exposure, recovery and post-bilateral cervical vagotomy. SO2 exposure significantly reduced the volume-dependent modulation of expiratory duration from the pre-treatment levels. The response to the expiratory loads returned when the SO2 gas was removed. Vagotomy completely abolished any volume-dependent modulation of expiratory duration with expiratory loading. These results demonstrate that the response of rabbits to expiratory loads is vagally dependent. The hypothesis that PSR are the vagal afferents mediating this response is supported by these results. PMID:6473947

Davenport, P W; Freed, A N; Rex, K A

1984-06-01

299

[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

300

Modification of the sulfur dioxide-iodine thermochemical hydrogen cycle with lanthanum sulfites and sulfates  

SciTech Connect

Variable composition, insoluble dilanthanum oxide-sulfite-sulfate-hydrates were prepared by reaction of lanthanum dioxymonosulfate with aqueous sulfur dioxide. These compositions reacted with iodine to yield sulfate in the solid phase, and hydrogen iodide and water in the gas phase. The highest yield of hydrogen iodide measured was 32% at 660 K for a few seconds reaction time of iodine with a reactant containing oxide-sulfite-sulfate with the approximate stoichiometry numbers, 0.9, 1.1, 1.0. Higher yields of hydrogen iodide were obtained by a second iodine oxidation after separation of the first solid product. These reactions are adaptable to a water splitting thermochemical cycle in which hydrogen is made by catalytic decomposition of hydrogen iodide at 700 K, and oxygen results from decomposition of the solid product at 1300 K.

Onstott, E.I.; Bowman, M.G.; Michnovicz, M.F.; Hollabaugh, C.M.

1984-01-01

301

The lithium-sulfur dioxide primary battery - Its characteristics, performance and applications  

NASA Astrophysics Data System (ADS)

The lithium-sulfur dioxide battery is a new primary battery system with many advantages over conventional batteries. It has an energy density up to 330 W h/kg (150 W h/lb), two to four times greater than zinc batteries, and can perform to temperatures as low as -54 C (-65 F). The battery can withstand high temperature storage at 71 C (160 F) for long periods of time and its shelf life is projected to be 5-10 years at 21 C (70 F). The chemistry, construction and detailed performance characteristics of the battery are presented. The Li/SO2 system provides an all-purpose, all-climate primary battery that is capable of filling a wide variety of military, industrial and consumer applications. A number of these applications are discussed. With increasing production and cost reduction, the Li/SO2 battery will be cost-competitive and will receive wide acceptability and use.

Linden, D.; McDonald, B.

1980-03-01

302

The effect of a mouthrinse containing chlorine dioxide in the clinical reduction of volatile sulfur compounds.  

PubMed

This study sought to evaluate the clinical effect of a mouthrinse containing 0.3% chlorine dioxide (ClO2) in reducing oral volatile sulfur compounds (VSC). Halitosis was induced by L-cysteine in 11 volunteers, and 4 solutions were compared: a test solution containing 0.3% ClO2, 0.07% cetylpyridinium chloride (CPC), and 0.05% sodium fluoride; a placebo; a solution containing 0.05% CPC; and a control solution of 0.2% chlorhexidine gluconate (CHX). VSC levels were assessed using a Halimeter, and 6 measurements were made from baseline to 3 hours postrinse. The VSC reduction rate of the test mouthrinse was superior to the placebo and the CPC solution. There was no difference between the test solution and the CHX solution in VSC reduction rates immediately postrinse, or at 2 and 3 hours postrinse; both solutions were statistically superior to the placebo and the CPC solution. PMID:23823344

Soares, Leo G; Guaitolini, Roberto Luiz; Weyne, Sergio Carvalho; Falabella, Marcio Eduardo Vieira; Tinoco, Eduardo Muniz Barretto; Silva, Denise Gomes da

2013-07-01

303

Effects of sulfur dioxide and ozone on yield and quality of potatoes: Final report  

SciTech Connect

The objectives of this project were to develop an outdoor fumigation facility designed to expose plants to ozone (O3) and sulfur dioxide (SO2) and to conduct experiments that would examine the impact of the two gases alone and in combination on field grown potato plants. Two systems of dispensing and monitoring pollutants were contrasted, one using miniature solenoid valves and the other using critical orifices. Both systems provided excellent pollutant control. The orifices were relatively inexpensive and required less maintenance than did the solenoid valve system. Two field experiments were conducted, one in 1985 and and the other in 1986. Potato plants were exposed to charcoal filtered air, nonfiltered air, nonfiltered air supplemented with O3 at levels which resulted in 1.33, 1.66 or 1.99 times ambient O3 concentrations or charcoal filtered air plus 0.14, 0.28 or 0.56 ppM SO2. There were additional treatments combining the two pollutant regimes. Ozone induced a linear reduction in yield reflected by decreases in weight and number of tubers > 6.35 cm in diameter. In general effects on number and weight of smaller tubers were not detected. Ozone also induced a decrease in the percent dry matter and reducing sugar content of potato tubers. Sulfur dioxide affected number of Grade One tubers in both years and percent dry matter and sucrose content in 1986 only. While dose-response curves for all SO2 effects fit quadratic curves the impact of SO2 doses used in these experiments were stimulatory. No important interactions were observed between O3 and SO2. 36 refs., 5 figs., 31 tabs.

Pell, E.J.; Pearson, N.S.; Vinten-Johansen, C.; McGruer, G.; Yang, Y.

1989-01-01

304

Understanding volcanic processes using UV camera measurements of sulfur dioxide and coincident infrasound and seismicity  

NASA Astrophysics Data System (ADS)

The exsolution of volatiles from magma maintains an important control on volcanic eruption styles. The nucleation, growth, and connectivity of bubbles during magma ascent provide the driving force behind eruptions, and the rate, volume, and ease of gas exsolution can affect eruptive activity. Volcanic plumes are the observable consequence of this magmatic degassing, and remote sensing techniques allow us to quantify changes in gas exsolution. However, until recently the methods used to measure volcanic plumes did not have the capability of detecting rapid changes in degassing on the scale of standard geophysical observations. The advent of the UV camera now makes high sample rate gas measurements possible. This type of dataset can then be compared to other volcanic observations to provide an in depth picture of degassing mechanisms in the shallow conduit. The goals of this research are to develop a robust methodology for UV camera field measurements of volcanic plumes, and utilize this data in conjunction with seismoacoustic records to illuminate degassing processes. Field and laboratory experiments were conducted to determine the effects of imaging conditions, vignetting, exposure time, calibration technique, and filter usage on the UV camera sulfur dioxide measurements. Using the best practices determined from these studies, a field campaign was undertaken at Volcan de Pacaya, Guatemala. Coincident plume sulfur dioxide measurements, acoustic recordings, and seismic observations were collected and analyzed jointly. The results provide insight into the small explosive features, variations in degassing rate, and plumbing system of this complex volcanic system. This research provides useful information for determining volcanic hazard at Pacaya, and demonstrates the potential of the UV camera in multiparameter studies.

Dalton, Marika Piirak

305

Processing of microcrystalline cellulose in dimethyl sulfoxide, urea and supercritical carbon dioxide.  

PubMed

Efficient utilization of cellulose in polymer blends is limited because of its high crystallinity. In this work, an attempt to change the inherent crystallinity of cellulose was performed by exposing it to two systems viz. dimethyl sulfoxide (DMSO)-supercritical CO2 and DMSO-urea-supercritical CO2. The cellulose samples processed in DMSO-supercritical CO2 system at 2500psi, 3500psi, and 4500psi showed a reducing trend of the relative crystallinity with increasing pressure. The reduction in the relative crystallinity occurred due to weakening of inter-chain hydrogen bonds in cellulose. The cellulose samples were processed in DMSO-urea-supercritical system at 2500psi and 4500psi. A maximum 55% reduction in relative crystallinity was found in the sample that contained 1.80mol fractions of urea and processed at 2500psi. This reduction in crystallinity was due to the presence of a DMSO-urea complex, which caused weakening of intermolecular hydrogen bond and an intramolecular hydrogen bond. PMID:23499114

Selarka, Aniket; Baney, Ronald; Matthews, Siobhan

2012-12-28

306

Use of sulfur-34 to measure the absorption rate of sulfur dioxide on the leaves of plants  

Microsoft Academic Search

A new method has been developed for measuring the rate of sulphur ; dioxide absorption by plants. This rate is deduced from the isotopic composition ; of the sulphur contained in plants before and after fumigation with ³⁴S-; enriched sulphur dioxide, the production of which is also described. The ; fumigation, which is carried out in the field with a

Y. Belot; J. C. Bourreau; M. Dubois; C. Pauly

1975-01-01

307

Temporal evolution of sulfur dioxide and nitrogen oxides in the city of Volos, Greece.  

PubMed

The goal of this work is the analysis of air quality levels in the area of Volos, a city of average size on the eastern seaboard of Central Greece. For this purpose, concentration measurements of sulfur dioxide, nitrogen oxide, and nitrogen dioxide, for a 4-year period (2001-2004) are analyzed. Air pollution data were obtained by a monitoring station, fully automated, which was established by the Hellenic Ministry of the Environment, Physical Planning, and Public Works, in order to measure air pollution levels in Volos, a medium-sized city, which faces the effects of industrialization. The main conclusions from the statistical analysis of the 4-year measurements of hourly SO(2), NO(2), and NO concentrations in the city of Volos, showed that the mean seasonal variation of the examined air pollutant concentration presents a minimum during the warm period of the year and a maximum during the cold period. Although the local geomorphology and meteorology encourage particularly the accumulation of air pollutants, the analysis shows that the SO(2) and NO(2) concentration levels remain lower than corresponding thresholds for human health protection set by the European Union, in this urban measuring site, during the examined period. The application of harmonic analysis revealed the difference between the annual variation of the SO(2) and NO(x) concentrations. Regarding NO(x), the variation is mainly due to the first harmonic term (anthropogenic factor), while the SO(2) variation is interpreted by the two harmonic terms, which represent the anthropogenic and meteorological factors, respectively. PMID:19238571

Papaioannou, A B; Viras, L G; Nastos, P T; Paliatsos, A G

2009-02-24

308

Temporary Disturbance of Translocation of Assimilates in Douglas Firs Caused by Low Levels of Ozone and Sulfur Dioxide 1  

PubMed Central

Douglas firs (Pseudotsuga menziesii [Mirb.] Franco) are suffering strongly from air pollution in western Europe. We studied the effect of low concentrations of ozone (200 micrograms per cubic meter during 3 days) and sulfur dioxide (53 micrograms per cubic meter during 28 days) on translocation of assimilates in 2 year old Douglas firs. The trees were exposed to the pollutants and afterward transferred to a growth chamber adapted to the use of 14CO2. Root/soil respiration was measured daily. The results showed a significant decrease of the 14CO2 root/soil respiration during the first 1 to 2 weeks after exposure to either ozone or sulfur dioxide. The ultimate level of 14CO2 root/soil respiration did not differ significantly, which suggests a recovery of the exposed trees during the first weeks after exposure.

Gorissen, Antonie; van Veen, Johannes A.

1988-01-01

309

Efficiency of Removing Sulfur Dioxide in the Air by Non-Thermal Plasma Along with the Application of the Magnetic Field  

Microsoft Academic Search

The non-thermal plasma created by high voltage pulsed power supply can be used to remove sulfur dioxide in the air, but how to increase the removing efficiency is not clear. It is novel to apply the magnetic field in removing SO2 as discussed in this paper. The mechanisms of removing sulfur dioxide by non-thermal plasma along with the application of

Jingjing Liu; Xiaohua Wang; Xingcheng Yuan; Mingzhe Rong

2005-01-01

310

Estimation of dry deposition velocities of nitric oxide, sulfur dioxide, and ozone by the gradient method above short vegetation during the tract campaign  

Microsoft Academic Search

Dry flux and dry deposition velocity of nitric oxide, sulfur dioxide and ozone were measured by the gradient method during the TRACT campaign in Rhine valley, Germany, above a surface covered by short vegetation. Eddy diffusivity was calculated by means of MoninObukhovs similarity theory. Calculated dry deposition velocities for ozone and sulfur dioxide were 0.050.07 and 0.190.20cms-1 in stable and

L Horvth; Z Nagy; T Weidinger

1998-01-01

311

Removal of sulfur dioxide from a continuously operated binary fluidized bed reactor using inert solids and hydrated lime  

Microsoft Academic Search

Sulfur dioxide pollutant was treated in the laboratory with hydrated lime particles having a mean diameter of 9.1?m in a continuously operating binary fluidized bed reactor also containing inert sand particles with sizes varying from 500 to 590?m. The influence of temperature (500, 600, 700 and 800C) on the reaction medium, of the superficial velocity of the gas (0.8, 1.0

R. Pisani; D. de Moraes

2004-01-01

312

Age-Related Alterations in Antioxidant Enzymes, Lipid Peroxide Levels, and Somatosensory-Evoked Potentials: Effect of Sulfur Dioxide  

Microsoft Academic Search

. The effect of sulfur dioxide (SO2) on somatosensory-evoked potentials (SEPs), thiobarbituric acid reactive substances (TBARS), and the activities of Cu,Zn-superoxide\\u000a dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) were investigated in young (3 months), middle-age (12\\u000a months), and old (24 months) Swiss male albino rats. Ten ppm SO2 was administrated to the animals of SO2 groups in an exposure

P. Yargio?lu; A. A?ar; S. Gm?l; S. Bilmen; Y. O?uz

1999-01-01

313

Profile measurements of sulfur dioxide, nitrogen oxides, and nitric acid deposition velocities in California's South Coast Air Basin  

Microsoft Academic Search

The Desert Research Institute performed a three-week dry-deposition-measurement field program in the South Coast Air Basin of California to quantify the deposition velocities and their associated uncertainties for sulfur dioxide, sulfate aerosol, nitrogen oxides, and nitric acid. The measurements took place in May and June, 1986 on a flat, grass-covered surface near Carson, CA. Deposition velocities were estimated by the

A. W. Gertler; G. Prowell; N. F. Robinson; D. Rogers; F. Rogers

1989-01-01

314

From Sulfur Dioxide to Greenhouse Gases: Trends and Events Shaping Future Emissions Trading Programs in the United States  

Microsoft Academic Search

The success of the United States sulfur dioxide (SO2) trading program has led to worldwide interest in emissions trading. The program has become a model for policymakers in the\\u000a United States and in other countries that are considering cap-and-trade programs to reduce emissions. Once a theoretical option\\u000a discussed only by economists, emissions trading is now considered a mainstream policy instrument

Joseph Kruger

315

Productivity of field-grown soybeans exposed to acid rain and sulfur dioxide alone and in combination  

Microsoft Academic Search

Sulfur dioxide (SO)-fumigated and unfumigated field plots of soybeans (Glycine max cv. Wells) were exposed to acid (pH 3.1) or control (pH approx. =5.3) precipitation simulants to determine effects on growth and productivity. The precipitation simulants were applied at approximately 5-day intervals in July and August with a total of 3.4 cm applied in 1977 and 4.5 cm in 1978.

P. M. Irving; J. E. Miller

1981-01-01

316

Retrieval of vertical columns of sulfur dioxide from SCIAMACHY and OMI: Air mass factor algorithm development, validation, and error analysis  

Microsoft Academic Search

We develop an improved retrieval of sulfur dioxide (SO2) vertical columns from two satellite instruments (SCIAMACHY and OMI) that measure ultraviolet solar backscatter. For each SCIAMACHY and OMI observation, a local air mass factor (AMF) algorithm converts line-of-sight slant columns to vertical columns using altitude-dependent scattering weights computed with a radiative transfer model (LIDORT), weighted by relative vertical SO2 profile

Chulkyu Lee; Randall V. Martin; Aaron van Donkelaar; Gray O'Byrne; Nickolay Krotkov; Andreas Richter; L. Gregory Huey; John S. Holloway

2009-01-01

317

Reactions of sulfur dioxide on calcium carbonate single crystal and particle surfaces at the adsorbed water carbonate interface  

Microsoft Academic Search

Sulfur dioxide reactions with calcium carbonate interfaces at 296 K in the presence and absence of adsorbed water result in the formation of adsorbed sulfite and sulfate. The extent of reaction is significantly enhanced, approximately five- to ten-fold for particulate and single crystal CaCO3 (calcite), respectively, in the presence of adsorbed water between 30 and 85% RH. Atomic force microscopy

Jonas Baltrusaitis; Courtney R. Usher; Vicki H. Grassian

2007-01-01

318

Formation of secondary organic aerosol from irradiated ?-pinene\\/toluene\\/NOx mixtures and the effect of isoprene and sulfur dioxide  

Microsoft Academic Search

Secondary organic aerosol (SOA) was generated by irradiating a series of ?-pinene\\/toluene\\/NOx mixtures in the absence and presence of isoprene or sulfur dioxide. The purpose of the experiment was to evaluate the extent to which chemical perturbations to this base-case (?-pinene\\/toluene) mixture led to changes in the gas-phase chemistry which strongly influences mass and composition of SOA and secondary organic

Mohammed Jaoui; Edward O. Edney; Tadeusz E. Kleindienst; Michael Lewandowski; John H. Offenberg; Jason D. Surratt; John H. Seinfeld

2008-01-01

319

Pulmonary response to threshold levels of sulfur dioxide (1. 0 ppm) and ozone (0. 3 ppm) (journal version)  

SciTech Connect

The authors exposed 22 healthy adult non-smoking men for 2 hours to either filtered air, 1.0 ppm sulfur dioxide, 0.30 ppm ozone, or the combination of 1.0 ppm sulfur dioxide plus 0.30 ppm ozone. It was hypothesized that exposure to near-threshold concentrations of these pollutants would show any interaction between the two pollutants that might have been masked by the more-obvious response to the higher concentrations of ozone used in previous studies. Each subject alternated 30-minute treadmill exercise with 10-minute rest periods for the 2 hours. Following ozone exposure alone, forced expiratory measurements (FVC, FEV-1, and FEF25-75%) were significantly decreased. The combined exposure to SO/sub 2/ plus O/sub 3/ produced similar but smaller decreases in these measures. There were small but significant differences between the ozone and the ozone plus sulfur dioxide exposure for FVC, FEV-1,-2,-3, and FEF25-75% at the end of the 2-hour exposure. It was concluded that, with these pollutant concentrations, there is no additive or synergistic effect of the two pollutants on pulmonary function.

Folinsbee, L.J.; Bedi, J.F.; Horvath, S.M.

1985-01-01

320

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

321

Bioassay for assessing the effect of sulfur dioxide on oat seedlings  

SciTech Connect

A bioassay technique was developed to evaluate the effect of sulfur dioxide air pollution on the growth rates of oat seedlings. The system was designed to measure small changes in shoot length of seedlings in vivo by use of a millimeter rule. The data, subjected to appropriate statistical evaluation, lead to the conclusion that oat seedlings experienced subtle injury in the form of growth retardation during exposure to SO/sub 2/ at concentrations close to ambient levels. Recovery of the seedlings was relatively rapid and indirectly proportional to SO/sub 2/ concentration. However, recovery generally did not reach the rate of growth that existed prior to fumigation, indicating the possibility of permanent growth impairment or that the stationary phase of growth was being approached. Knowledge of subtle injury of vegetation as seen in this study could possibly lead to in vivo systems for the direct evaluation of air pollution effects on vegetation, help to expand knowledge in the areas of economic loss, or possibly aid in the selection of tolerant species as buffer zones in land use planning.

Marchesani, V.J.; Leone, I.A.

1980-01-01

322

Seasonal variations in elemental carbon aerosol, carbon monoxide and sulfur dioxide: Implications for sources  

NASA Astrophysics Data System (ADS)

As part of Maryland Aerosol Research and CHaracterization (MARCH-Atlantic) study, measurements of 24-hr average elemental carbon (EC) aerosol concentration were made at Fort Meade, Maryland, USA, a suburban site within the Baltimore-Washington corridor during July 1999, October 1999, January 2000, April 2000 and July 2000. Carbon monoxide (CO) and sulfur dioxide (SO2) were also measured nearly continuously over the period. Tight correlation between EC and CO in every month suggests common or proximate sources, likely traffic emissions. The EC versus CO slope varies in different seasons and generally increases with ambient temperature. The temperature dependence of EC/CO ratios suggests that EC source strength peaks in summer. By using the well established emission inventory for CO, and EC/CO ratio found in this study, EC emission over North America is estimated at 0.310.12 Tg yr-1, on the low end but in reasonable agreement with prior inventories based on emission factors and fuel consumption.

Antony Chen, L.-W.; Doddridge, Bruce G.; Dickerson, Russell R.; Chow, Judith C.; Mueller, Peter K.; Quinn, John; Butler, William A.

323

Seasonal variations in elemental carbon aerosol, carbon monoxide and sulfur dioxide: Implications for sources  

NASA Astrophysics Data System (ADS)

As part of Maryland Aerosol Research and CHaracterization (MARCH-Atlantic) study, measurements of 24-hr average elemental carbon (EC) aerosol concentration were made at Fort Meade, Maryland, USA, a suburban site within the Baltimore-Washington corridor during July 1999, October 1999, January 2000, April 2000 and July 2000. Carbon monoxide (CO) and sulfur dioxide (SO2) were also measured nearly continuously over the period. Tight correlation between EC and CO in every month suggests common or proximate sources, likely traffic emissions. The EC versus CO slope varies in different seasons and generally increases with ambient temperature. The temperature dependence of EC/CO ratios suggests that EC source strength peaks in summer. By using the well established emission inventory for CO, and EC/CO ratio found in this study, EC emission over North America is estimated at 0.31+/-0.12Tgyr-1, on the low end but in reasonable agreement with prior inventories based on emission factors and fuel consumption.

Chen, L.-W. Antony; Doddridge, Bruce G.; Dickerson, Russell R.; Chow, Judith C.; Mueller, Peter K.; Quinn, John; Butler, William A.

2001-05-01

324

Effect of sulfur dioxide inhalation on erythrocyte antioxidant status and lipid peroxidation in experimental diabetes.  

PubMed

The effect of sulfur dioxide (SO(2) ) on red cell antioxidant status and lipid peroxidation was examined in this research. Forty healthy male albino rats, aged three months, were divided into four equal groups: Control (C), SO(2) +C (CSO(2) ), diabetic (D) and SO(2) +D (DSO(2) ). Experimental diabetes mellitus was induced by i.v injection of alloxan with a dose of 50 mg/kg body weight. Ten ppm SO(2) was administered to the animals of SO(2) exposed groups in an exposure chamber for one hr/day x 7 days/wk x 6wks while other groups were exposed to filtered air in the same condition. SO(2) exposure, while markedly decreasing Cu, Zn-Superoxide dismutase (Cu, Zn-SOD) activity, significantly increased glutathione peroxidase (GSH-Px), catalase (CAT), glutathione (GSH) and glutathione-s-transferase (GST) activities and TBARS values in CSO(2) and DSO(2) groups compared with their respective control groups. From these results, it could be concluded that adaptative changes occurred in antioxidant systems that may counteract the free radical effect of SO(2) in the experimental groups. PMID:10804329

Agar, A; Kkatay, V; Yargicoglu, P; Bilmen, S; Gm?l, S; Ycel, G

2000-04-01

325

Ion chromatographic measurement of fluoride and sulfur dioxide in samples collected at aluminum smelters  

SciTech Connect

Measurement of airborne fluoride and sulfur dioxide in aluminum smelting plants is important for both industrial hygiene and environmental reasons. The traditional analytical techniques employed have been ion-selective electrodes (ISE) for fluoride and barium/thorin titration for SO2. In this study, ion chromatography (IC) was evaluated as a substitute for these two techniques. Dust for particulate fluoride was collected on membrane filters with carbonate-treated backup pads to collect HF and SO2. Gaseous fluoride and SO2 were ultrasonically extracted from the treated pad, but particulate fluoride required a borate/carbonate fusion. Collection efficiency and recovery of the analytes, along with the acceptable working ranges and instrument conditions used with IC, are discussed. IC is a desirable substitute for the electrode and titration methods because it is easily automated and the two determinations may be performed simultaneously. Organic compounds may cause interference in low-level fluoride measurement. Comparison of the techniques for field samples indicates that IC is an adequate substitute for the traditional measurement methods for full-shift samples of fluoride.

Balya, D.R. (Aluminum Company of America, Alcoa Technical Center, PA (United States))

1991-08-01

326

Core localization and {sigma}* delocalization in the O 1s core-excited sulfur dioxide molecule  

SciTech Connect

Electron-ion-ion coincidence measurements of sulfur dioxide at discrete resonances near the O 1s ionization edge are reported. The spectra are analyzed using a model based upon molecular symmetry and on the geometry of the molecule. We find clear evidence for molecular alignment that can be ascribed to symmetry properties of the ground and core-excited states. Configuration interaction (CI) calculations indicate geometry changes in accord with the measured spectra. For the SO{sub 2} molecule, however, we find that the localized core hole does not produce measurable evidence for valence localization, since the transition dipole moment is not parallel to a breaking {sigma}* O-S bond, in contrast to the case of ozone. The dissociation behavior based upon the CI calculations using symmetry-broken orbitals while fixing a localized core-hole site is found to be nearly equivalent to that using symmetry-adapted orbitals. This implies that the core-localization effect is not strong enough to localize the {sigma}* valence orbital.

Lindgren, Andreas; Kivimaeki, Antti; Sorensen, Stacey L. [Department of Synchrotron Radiation Research, Institute of Physics, University of Lund, S-221 00 Lund (Sweden); Kosugi, Nobuhiro [UVSOR, Institute for Molecular Science (IMS), Myodaiji, Okazaki 444-8585 (Japan); Gisselbrecht, Mathieu [MAX-Lab, Box 118, University of Lund, S-221 00 Lund (Sweden); Burmeister, Florian [Department of Physics, Uppsala University, Box 530, S-751 21 Uppsala (Sweden); Naves de Brito, Arnaldo [Laboratorio Nacional de Luz Sincrotron (LNLS), Box 6192, 13084-971 Campinas SP (Brazil)

2008-03-21

327

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

328

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

329

Remote sensing of sulfur dioxide effects on vegetation. Volume I. Summary. Final report 1976-1980  

SciTech Connect

Three techniques for detecting and mapping sulfur dioxide (SO2) effects on the foliage of sensitive crops and trees near large, coal-fired power plants were tested and evaluated. These techniques were spectroradiometry, photometric analysis of aerial photographs, and computer analysis of airborne multispectral scanner data. Spectroradiometry is a useful, ground-based technique for measuring the changes in reflectance that accompany exposure of sensitive crops to SO2. Photometric analysis of aerial color-infrared photographs has some practical advantages for measuring the reflectances of forest species or for synoptic point-sampling of extensive areas; these tasks cannot be done effectively by field crews. The relationships among reflectance, foliar injury, and yield of crops are complex and are affected by many extraneous variables such as canopy density. The SO2 effects are easier to detect on winter wheat than on soybeans, but in either case they cannot be consistently detected by airborne remote sensors except under near-ideal conditions when the injury is moderate to severe. Airborne multispectral scanner data covering affected soybean fields were analyzed using three computer-assisted procedures: unsupervised, supervised, and pseudosupervised; the last method provided the best results. Landsat imagery was also investigated, but the foliar effects of SO2 were too subtle to detect from orbit.

Sapp, C.D.

1981-07-01

330

Remote sensing of sulfur dioxide effects on vegetation. Final report. Volume II: data  

SciTech Connect

Three techniques for detecting and mapping sulfur-dioxide (SO/sub 2/) effects on the foliage of sensitive crops and trees near large, coal-fired power plants were tested and evaluated. These techniques were spectroradiometry, photometric analysis of aerial photographs, and computer classification of airborne multispectral scanner data. Spectroradiometry is a useful, ground-based technique for measuring the changes in reflectance that accompany expsure of sensitive crops to SO/sub 2/. Photometric analysis of aerial color-infrared photographs has some practical advantages for measuring the reflectances of forest species or for synoptic point-sampling of extensive areas; these tasks cannot be done effectively by field crews. The relationships among reflectance, foliar injury, and yield of crops are complex and are affected by many extraneous variables such as canopy density. The SO/sub 2/ effects are easier to detect on winter wheat than on soybeans, but in either case they cannot be consistently detected by airborne remote sensors except under near-ideal conditions when the injury is moderate to severe. Airborne multispectral scanner data covering affected soybean fields were analyzed using three computer-assisted classification procedures: unsupervised, supervised, and pseudosupervised; the last method provided the best results. Landsat imagery was also investigated, but the foliar effects of SO/sub 2/ were too subtle to detect from orbit.

Sapp, C.D.

1981-07-01

331

Remote sensing of sulfur dioxide effects on vegetation. Final report. Volume I: summary  

SciTech Connect

Three techniques for detecting and mapping sulfur dioxide (SO/sub 2/) effects on the foliage of sensitive crops and trees near large, coal-fired power plants were tested and evaluated. These techniques were spectroradiometry, photometric analysis of aerial photographs, and computer analysis of airborne multispectral scanner data. Spectroradiometry is a useful, ground-based technique for measuring the changes in reflectance that accompany exposure of sensitive crops to SO/sub 2/. Photometric analysis of aerial color-infrared photographs has some practical advantages for measuring the reflectances of forest species or for synoptic point-sampling of extensive areas; these tasks cannot be done effectively by field crews. The relationships among reflectance, foliar injury, and yield of crops are complex and are affected by many extraneous variables such as canopy density. The SO/sub 2/ effects are easier to detect on winter wheat than on soybeans, but in either case they cannot be consistently detected by airborne remote sensors except under near-ideal conditions when the injury is moderate to severe. Airborne multispectral scanner data covering affected soybean fields were analyzed using three computer-assisted procedures: unsupervised, supervised, and pseudosupervised; the last method provided the best results. Landsat imagery was also investigated, but the foliar effects of SO/sub 2/ were too subtle to detect from orbit.

Sapp, C.D.

1981-07-01

332

A model for the oxidation of sulfur dioxide in a trickle-bed reactor  

SciTech Connect

A reaction rate model based on complete wetting of the catalyst particles in a trickle-bed reactor is presented. It is considered that the pendular rings are formed at the contact points of the particles and the liquid flows down as thin films on the remaining surface between the pendular rings. Assuming that the flow in the films is laminar, the liquid in the pendular rings is well-mixed, and a fraction of the liquid flowing in the films bypasses the pendular rings, the reaction rate was found. The data obtained for oxidation of sulfur dioxide on activated carbon were used to test the model predictions of the dependence of reaction rate on liquid velocity. The reaction rates in nonprewetted beds were found to be lower than those in prewetted beds. The proposed model correlated the observed reaction rates satisfactorily, with the fractional thickness of the film that bypasses the pendular ring as an adjustable parameter. The model also predicted the reaction rate trends, including the minimum of the oxidation rate reported by Mata and Smith.

Ravindra, P.V.; Rao, D.P.; Rao, M.S. [Indian Inst. of Tech., Kanpur (India). Dept. of Chemical Engineering

1997-12-01

333

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

334

The GOES-R Approach to Imager Based Sulfur Dioxide Detection  

NASA Astrophysics Data System (ADS)

An automated sulfur dioxide (SO2) detection algorithm designed for the Advanced Baseline Imager (ABI) on the next generation of Geostationary Operational Environmental Satellites (GOES-R) is described. SO2 is present in many volcanic eruptions and may present a danger to aircraft, so the ability to identify SO2 clouds is important. This algorithm utilizes infrared SO2 absorption bands and cloud microphysical properties to infer the presence of SO2. Data from the Spinning Enhanced Visible-Infrared Imager (SEVIRI) are used as a proxy for the ABI, and the results of the algorithm are compared to SO2 detected by the Ozone Monitoring Instrument (OMI), which is highly sensitive to SO2. Our results show that the algorithm can identify the presence of SO2 with high skill for SO2 loading greater than 10 Dobson Units. This SO2 product will provide valuable information in near real-time to Volcanic Ash Advisory Centers (VAACs) in the GOES-R era.

Parker, A. C.; Pavolonis, M. J.

2009-12-01

335

Foliar response and growth of apple trees following exposure to ozone and sulfur dioxide  

SciTech Connect

Three cultivars of greenhouse-grown apple trees (Malus domestica, Borkh.) were fumigated for single, 4-hour exposures with ozone (O/sub 3/) and/or sulfur dioxide (SO/sub 2/) at 0.40 and 0.80 ppm. Fumigations were performed in a plexiglass chamber situated within a controlled environment walk-in growth chamber. All 3 cultivars responded to treatments in a similar manner. When applied separately both gases induced characteristic foliar injury. In general, apple trees were more sensitive to 0.40 ppm O/sub 3/ than to 0.40 ppm SO/sub 2/; but they responded similarly to 0.80 ppm O/sub 3/ or SO/sub 2/. Foliar injury, leaf abscission, and shoot growth reduction were greatest when 0.80 ppm O/sub 3/ and 0.80 ppm SO/sub 2/ were combined. The data showed a less-than additive response when the 2 pollutants were combined; a response due, in part, to the high amount of injury induced by single pollutants at these concentrations. All O/sub 3/ and/or SO/sub 2/ fumigations resulted in stomatal closure.

Shertz, R.D.; Kender, W.J.; Musselman, R.C.

1980-01-01

336

Charged particle formation by the ionization of air containing sulfur dioxide  

NASA Astrophysics Data System (ADS)

Experimental investigation of charged particle formation by the ionization of air containing sulfur dioxide (SO2) was performed using a nano-DMA (differential mobility analyzer) and an atmospheric pressure ionization mass spectrometer. A radioactive ion source of 241Am and a negative dc corona discharge were used to ionize SO2/H2O/air mixtures. The results showed that the number of charged particles that formed had increased as H2O concentration increased (ca. 20-3 103 ppm) for both ion sources, but also that the number of charged particles produced when using the negative corona discharge was more than two orders of magnitude greater than what was produced using 241Am. During ionization by [alpha]-ray irradiation, SO4-(H2O)n ions predominated coincident with the formation of charged particles. The negative corona discharge produced a more complicated ion mass spectrum, which included ion groups of NO3-, SOx- (x = 2-5) and HSOx- (x = 3-5). The relative abundance of the ion groups varied depending on H2O concentration and ion reaction time. The ions with an HSO4- core surpassed the ions of other groups as H2O concentration increased. The formations of NO3- ions and cluster ions containing HNO3 also were enhanced at higher H2O concentrations. Possible ion-molecule reactions responsible for the observed mass spectra are discussed in detail.

Nagato, Kenkichi

2009-08-01

337

Effect of sulfur dioxide on the morphology and mucin biosynthesis by the rat trachea  

SciTech Connect

Specific-pathogen-free rats were exposed to 400 ppM sulfur dioxide daily for up to 7 weeks. At intervals during exposure, tracheas were removed and incubated in vitro in culture medium containing radioactive glycoprotein precursors. The most prominent histological changes due to SO/sub 2/ were progressive hypertrophy and hyperplasia of the submucosal mucous glands accompanied by a flattening of the epithelium with eventual recovery. Uptake of radioactive precursors into a highly purified mucin fraction correlated with these histological changes in the submucosal mucous glands, increasing progressively up to 4 times that of control. Uptake of precursors into specific mucins purified by DEAE-Sephacel showed that uptake into the 0.2 and 0.3 M NaCl fractions was stimulated several fold by SO/sub 2/, and uptake into more highly acidic fractions, which was nearly absent in the control, was also greatly increased. Two weeks following the last exposure of the tracheas to SO/sub 2/, their morphological and mucus-secreting properties showed signs of returning to that of the control.

Clark, J.N.; Dalbey, W.E.; Stephenson, K.B.

1980-01-01

338

Influence of soil moisture on macroscopic sulfur dioxide injury to pinto bean foliage  

SciTech Connect

The influence of soil moisture stress on sulfur dioxide (SO/sub 2/) injury to pinto bean foliage was investigated in relation to stomatal conductance rate, soil moisture content, and plant water potential. Pinto bean plants were grown at four soil water potentials (-1/3, -1, -3, and -5 atm) and exposed to 5,720 ..mu..g/m/sup 3/ (2.2 ppm) SO/sub 2/ for 3 hr. Macroscopic injury was severe on plants grown at -1/3 and -1 atm soil water potential and negligible on plants grown at -3 and -5 atm water potential. Injury was highly correlated with percentage of soil moisture, and both injury and soil moisture were highly correlated with stomatal conductance rate and water potential of the plants. The duration of soil moisture stress (1, 2, or 3 days) did not affect the amount of macroscopic injury induced by SO/sub 2/, the stomatal conductance rate, or plant water potential. Stomatal conductance rates of plants grown at -1/3 and -1 atm soil water potential decreased when the plants were exposed to SO/sub 2/, while those of plants grown at -3 and -5 atm soil water potential were not affected by exposure to SO/sub 2/.

Davids, J.A.; Davis, D.D.; Pennypacker, S.P.

1981-01-01

339

The Reductive Tricarboxylic Acid Cycle of Carbon Dioxide Assimilation: Initial Studies and Purification of ATP-Citrate Lyase from the Green Sulfur Bacterium Chlorobium tepidum  

Microsoft Academic Search

Carbon dioxide is fixed largely by the reductive tricarboxylic acid (RTCA) cycle in green sulfur bacteria. One of the key enzymes, ATP-citrate lyase, was purified to apparent homogeneity from the moderately thermophilic green sulfur bacterium Chlorobium tepidum. The molecular weight of the native enzyme was about 550,000, and the preponderance of evidence indicated that the protein is composed of identical

THOMAS M. WAHLUND; F. ROBERT TABITA

340

Feasibility of installing sulfur dioxide scrubbers on stationary sources in the south coast air basin of California. Volume II: technical discussion. Final report  

Microsoft Academic Search

The feasibility and costs of flue gas scrubbing to remove sulfur dioxide were determined for selected oil-fired power plants and industrial sources of SO (including flue gas from fluid catalytic cracking units, coke calcining kilns and sulfuric acid plants) in the Los Angeles area. The objective was to achieve a 90 percent reduction in SO emissions from each facility. Technical

P. P. Leo; J. Rossoff

1978-01-01

341

Selective catalytic reduction of sulfur dioxide to elemental sulfur. Quarterly technical progress report No. 6, October--December 1993  

SciTech Connect

Elemental sulfur recovery from SO{sub 2}-containing gas stream is highly attractive as it produces a salable product and no waste to dispose of. However, commercially available schemes are complex and involve multi-stage reactors, such as, most notably in the Resox (reduction of SO{sub 2} with coke) and Claus plant (reaction of SO{sub 2} with H{sub 2}S over catalyst). This project will investigate a cerium oxide catalyst for the single stage selective reduction of SO{sub 2} to elemental sulfur by a reductant, such as carbon monoxide. Cerium oxide has been identified in recent work at MIT as a superior catalyst for SO{sub 2} reduction by CO to elemental sulfur because its high activity and high selectivity to sulfur over COS over a wide temperature range (400--650{degree}C). The detailed kinetic and parametric studies of SO{sub 2} reduction planned in this work over various CeO{sub 2} formulations will provide the necessary basis for development of a very simplified process, namely that of a single-stage elemental sulfur recovery scheme from variable concentration gas streams. The potential cost- and energy-efficiency benefits from this approach can not be overstated. A first apparent application is treatment of a regenerator off-gases in power plants using regenerative flue gas desulfurization. Such a simple catalytic converter may offer the long-sought ``Claus-alternative`` for coal-fired power plant applications.

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

1993-12-31

342

Effects of sulfur dioxide on apoptosis-related gene expressions in lungs from rats  

SciTech Connect

Sulfur dioxide (SO{sub 2},) is an air pollutant in densely populated areas as well as in areas polluted by coal-fired power plants, smelters, and sulfuric acid factories. In the present study, male Wistar rats were housed in exposure chambers and treated with 14.00 {+-} 1.01, 28.00 {+-} 1.77, and 56.00 {+-} 3.44mg/m{sup 3} SO{sub 2} for 6h/day for 7 days, while control rats were exposed to filtered air in the same condition. The mRNA and protein levels of three apoptosis-related genes (p53 and bax are promoters of apoptosis, whereas bcl-2 is apoptotic suppressor) were analyzed in lungs using a real-time reverse transcription-polymerise chain reaction (real-time RT-PCR) assay and immunohistochemistry method, and caspase-3 activities were detected. The results showed that mRNA levels of p53 and bax were increased in a dose-dependent manner and at the concentrations of 28.00 and 56.00mg/m{sup 3} SO{sub 2} the increases were significant (for p53: 1.23-fold at 28 mg/m{sup 3} and 1.39-fold at 56 mg/m{sup 3}; for bax: 1.77-fold at 28 mg/m{sup 3} and 2.26-fold at 56 mg/m{sup 3}, respectively), while mRNA levels of bcl-2 were decreased significantly (0.78-fold at 28 mg/m{sup 3} and 0.73-fold at 56 mg/m{sup 3}) in lungs of rats exposed to SO{sub 2}. Dose-dependent increase of p53 and bax proteins in the lungs was observed after SO{sub 2} inhalation, while decrease of bcl-2 protein levels was obtained using immunohistochemistry method. Caspase-3 activities were increased in lungs of rats after SO{sub 2} inhalation. These results lead to a conclusion that SO{sub 2}, exposure can change the expression of apoptosis-related genes, and it suggests that SO{sub 2} can induce apoptosis in lung of rat and may have relations with some apoptosis-related diseases. Elucidating the expression patterns of those factors after SO{sub 2} inhalation may be critical to our understanding mechanisms of SO{sub 2} toxicity and helpful for the therapeutic intervention.

Bai, J.L.; Meng, Z.Q. [Shanxi University, Taiyuan (China)

2005-12-01

343

Effects of sulfur dioxide on apoptosis-related gene expressions in lungs from rats.  

PubMed

Sulfur dioxide (SO2) is an air pollutant in densely populated areas as well as in areas polluted by coal-fired power plants, smelters, and sulfuric acid factories. In the present study, male Wistar rats were housed in exposure chambers and treated with 14.00+/-1.01, 28.00+/-1.77, and 56.00+/-3.44 mg/m3 SO2 for 6 h/day for 7 days, while control rats were exposed to filtered air in the same condition. The mRNA and protein levels of three apoptosis-related genes (p53 and bax are promoters of apoptosis, whereas bcl-2 is apoptotic suppressor) were analyzed in lungs using a real-time reverse transcription-polymerase chain reaction (real-time RT-PCR) assay and immunohistochemistry method, and caspase-3 activities were detected. The results showed that mRNA levels of p53 and bax were increased in a dose-dependent manner and at the concentrations of 28.00 and 56.00 mg/m3 SO2 the increases were significant (for p53: 1.23-fold at 28 mg/m3 and 1.39-fold at 56 mg/m3; for bax: 1.77-fold at 28 mg/m3 and 2.26-fold at 56 mg/m3, respectively), while mRNA levels of bcl-2 were decreased significantly (0.78-fold at 28 mg/m3 and 0.73-fold at 56 mg/m3) in lungs of rats exposed to SO2. Dose-dependent increase of p53 and bax proteins in the lungs was observed after SO2 inhalation, while decrease of bcl-2 protein levels was obtained using immunohistochemistry method. Caspase-3 activities were increased in lungs of rats after SO2 inhalation. These results lead to a conclusion that SO2 exposure can change the expression of apoptosis-related genes, and it suggests that SO2 can induce apoptosis in lung of rat and may have relations with some apoptosis-related diseases. Elucidating the expression patterns of those factors after SO2 inhalation may be critical to our understanding mechanisms of SO2 toxicity and helpful for the therapeutic intervention. PMID:16256253

Bai, Juli; Meng, Ziqiang

2005-10-26

344

Chemical method for removal of sulfur dioxide from stack gases. Final report  

Microsoft Academic Search

Flue gas desulfurization has a positive side; it affords a means to recover some valuable sulfur chemicals. The elemental sulfur market has been extremely tight in recent years, because the nation will run out of uncombined sulfur in the foreseeable future and because the energy needed to make hot water required in the Frash mining operation has become increasingly more

Tung

1985-01-01

345

Selective catalytic reduction of sulfur dioxide to elemental sulfur. Quarterly technical progress report No. 6, October 1993--December 1993  

SciTech Connect

Elemental sulfur recovery from SO{sub 2}-containing gas stream is highly attractive as it produces a salable product and no waste to dispose of. However, commercially available schemes are complex and involve multi-stage reactors, such as, most notably in the Resox (reduction of SO{sub 2} with coke) and Claus plant (reaction of SO{sub 2} with H{sub 2}S over catalyst). This project will investigate a cerium oxide catalyst for the single stage selective reduction of SO{sub 2} to elemental sulfur by a reductant, such as carbon monoxide. Cerium oxide has been identified in recent work at MIT as a superior catalyst for SO{sub 2} reduction by CO to elemental sulfur because its high activity and high selectivity to sulfur over COS over a wide temperature range(400-650 {degrees}C). The detailed kinetic and parametric studies of SO{sub 2} reduction planned in this work over various CeO{sub 2}-formulations will provide the necessary basis for development of a very simplified process, namely that of a single-stage elemental sulfur recovery scheme from variable concentration gas streams. The potential cost- and energy-efficiency benefits from this approach can not be overstated. A first apparent application is treatment of a regenerator off-gases in power plants using regenerative flue gas desulfurization. Such a simple catalytic converter may offer the long-sought {open_quotes}Claus-alternative{close_quotes} for coal-fired power plant applications.

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

1996-01-01

346

Integrating TOMS and TOVS retrievals of sulfur dioxide in volcanic clouds  

NASA Astrophysics Data System (ADS)

Ultraviolet backscatter data from the series of Total Ozone Mapping Spectrometer (TOMS) instruments have been used to construct a time series of volcanic sulfur dioxide (SO2) emissions covering the past ~24 years, except for an 18-month data gap in 1995-96. Recently a new technique for retrieving SO2 from infrared data collected by the High-Resolution Infrared Sounder (HIRS) on the TIROS Operational Vertical Sounder (TOVS) platform has been developed, based on a strong SO2 absorption band centered around 7.3 ?m. The TOVS data are global, cover almost 22 years, have a spatial resolution of 18 km at nadir (compared to 25-50 km for TOMS) and can be used by day or night (TOMS requires sunlight), and therefore provide a unique opportunity to independently cross-validate and evaluate the TOMS SO2 retrievals. The nighttime capability of TOVS and the uninterrupted dataset also permit extension of the TOMS volcanic SO2 record (e.g. to include eruptions at high latitudes in the winter months) and coverage of the TOMS data gap in 1995-96. As a case study of the relative merits of the UV TOMS and IR TOVS methods, we will present retrievals of SO2 in the stratospheric volcanic cloud produced by the August 1980 eruption of Hekla volcano, Iceland. This was a relatively modest eruption, producing ~470 kilotons of SO2 (measured by TOMS), but the resulting volcanic cloud was unusually long-lived and could be tracked by TOMS and TOVS for ~5 days as it circumnavigated the North Pole. Detailed intercomparison of SO2 retrievals from TOMS and TOVS, taking into account the different sensitivities and biases of the two methods, allows a thorough examination of the evolution of this SO2 cloud. Merging of the TOMS and TOVS datasets may also provide sufficient information on the movement of the volcanic cloud to permit validation of trajectory models (e.g. CANERM, HYSPLIT).

Carn, S. A.; Prata, F. J.; Karlsdottir, S.; Krueger, A. J.

2002-12-01

347

Pulmonary response to threshold levels of sulfur dioxide (1. 0 ppm) and ozone (0. 3 ppm)  

SciTech Connect

The authors exposed 22 healthy adult nonsmoking male subjects for 2 h to filtered air, 1.0 ppm sulfur dioxide (SO/sub 2/), 0.3 ppm ozone (O/sub 3/), or the combination of 1.0 ppm SO/sub 2/ + 0.3 ppm O/sub 3/. They hypothesized that exposure to near-threshold concentrations of these pollutants would allow them to observe any interaction between the two pollutants that might have been masked by the more obvious response to the higher concentrations of O/sub 3/ used in previous studies. Each subject alternated 30-min treadmill exercise with 10-min rest periods for the 2 h. The average exercise ventilation measured during the last 5 min of exercise was 38 1/min (BTPS). Forced expiratory maneuvers were performed before exposure and 5 min after each of the three exercise periods. Maximum voluntary ventilation, He dilution functional residual capacity, thoracic gas volume, and airway resistance were measured before and after the exposure. After O/sub 3/ exposure alone, forced expiratory measurements (FVC, FEV1.0, and FEF25-75%) were significantly decreased. The combined exposure to SO/sub 2/ + O/sub 3/ produced similar but smaller decreases in these measures. There were small but significant differences between the O/sub 3/ and the O/sub 3/ + SO/sub 2/ exposure for FVC, FEV1.0, FEV2.0, FEV3.0, and FEF25-75% at the end of the 2-h exposure. The authors conclude that, with these pollutant concentrations, there is no additive or synergistic effect of the two pollutants on pulmonary function.

Folinsbee, L.J.; Bedi, J.F.; Horvath, S.M.

1985-06-01

348

Emission, transport and validation of sulfur dioxide in the 2008 Okmok and Kasatochi eruption clouds  

NASA Astrophysics Data System (ADS)

Large explosive eruptions occurred at Okmok and Kasatochi (Aleutian Islands) on July 12 and August 7, 2008, respectively. Both eruptions injected sulfur dioxide (SO2) into the lower stratosphere at 52- 53N. We present retrievals of SO2 in the eruption clouds using ultraviolet (UV) measurements by the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite. Operational OMI SO2 data indicate stratospheric SO2 loadings of ~0.1 Tg from Okmok and ~1.5 Tg from Kasatochi. These amounts are refined using offline iterative spectral fitting (ISF) retrievals that correct for SO2 altitude and non-linear absorption at short UV wavelengths. Kasatochi produced the largest stratospheric SO2 loading measured since the eruption of Hudson (Chile) in August 1991, and the largest extra-tropical northern hemisphere SO2 loading observed since UV TOMS SO2 measurements began in 1978. The Okmok and Kasatochi volcanic clouds both drifted eastwards across North America, impacting aviation and providing rare opportunities to validate the OMI SO2 retrievals. Ground-based Brewer UV measurements detected the Kasatochi SO2 cloud as it drifted over Toronto on August 12 and 16. Derived SO2 column amounts compare favorably with the OMI measurements. Inspection of ozonesonde profiles for SO2 interference is underway. SO2 from Okmok was tracked by OMI as far as northern Europe, while the larger Kasatochi SO2 cloud segregated into multiple filaments that dispersed over the entire northern hemisphere northwards of ~30N during the subsequent month. Both eruptions produced long-lived stratospheric aerosol features detected by the spaceborne CALIPSO lidar. As the Kasatochi SO2 cloud dispersed, concomitant development of an extensive stratospheric sulfate aerosol layer was observed in the northern hemisphere.

Carn, S. A.; Krotkov, N. A.; Fioletov, V.; Yang, K.; Krueger, A. J.; Tarasick, D.

2008-12-01

349

Correcting satellite-based infrared sulfur dioxide retrievals for the presence of silicate ash  

NASA Astrophysics Data System (ADS)

Previous studies have suggested that the presence of silicate ash may cause the 8.6-?m sulfur dioxide (SO2) retrieval to overestimate total column abundances and contribute to variations between ultraviolet and 8.6-?m SO2 estimates. Tested here is a volcanic aerosol forward model which allows the determination of transmission spectra. The forward model is embedded into a three-layer atmospheric radiative transfer model, based upon the moderate spectral resolution atmospheric transmittance algorithm (MODTRAN) radiative transfer code. This model is used to investigate the effects of silicate ash on the 8.6-?m SO2 retrieval from satellite data. Forward modeling of transmission through volcanic clouds enables us to evaluate the assumptions and errors of current retrievals. Four free variables, (1) effective radius, (2) variance, (3) number of particles, and (4) spectral refractive index, are used to determine the transmission and single scattering albedo at 7-13 ?m. Here we present simplistic characterizations of three eruptions, containing sulfates, ice, or andesitic ash using this forward model. The ash correction model based on the aerosol forward model is tested on the ash-rich lobe of the 19 February 2001 eruption plume of Mount Cleveland volcano using Moderate Resolution Imaging Spectroradiometer (MODIS) data. Uncorrected MODIS radiance values estimate 22 kt of SO2, while ash-corrected radiances estimate 17 kt. The minimal reduction in total SO2 indicates that previous variations in ultraviolet and 8.6-?m SO2 retrievals are unlikely to be due solely to the presence of ash.

Kearney, C. S.; Watson, I. M.

2009-11-01

350

Sulfur dioxide observations above Venus' clouds by means of solar occultation in the infrared  

NASA Astrophysics Data System (ADS)

The experiment SOIR (Solar Occultation in the Infra-Red) - a part of the Venus Express mission - is performed for study of gaseous and aerosol vertical structure in Venus' mesosphere. The instrument of SOIR is an acousto-optical (AO) echelle spectrometer that operates at wavelengths 2.2-4.3 m with high spectral resolution (?/??=30000). The spectrometer is capable to detect important minor gaseous constituents such as CO, SO2 , HCl, HF, H2 O and HDO at altitudes 65-110 km. Here we report results from some occultation sessions with observation of 4 m SO2 band at latitudes 69o -88o N and 23o -30o N. It's the first time of SO2 vertical distribution retrieval above Venus' clouds by means of solar occultation. Since sulfur dioxide spectrum of transmission is measured on a background of abundant CO2 band, it is impossible to retrieve any separate SO2 line for observing and fitting. This fact forces us to do modeling of combined spectrum (CO2 *SO2 ) and to perform fitting with appropriate mixing ratio of SO2 by comparison between the combined model and a measured spectrum (point-by-point). As result, just a few points of a SO2 vertical profile can be detected clearly (0.1 ppm at high latitudes and 1 ppm at low latitudes at the altitude about 70 km). All the rest points provide upper limit of the gas' mixing ratio (0.05 ppm at 75 km and higher).

Belyaev, Denis; Korablev, Oleg; Fedorova, Anna; Bertaux, Jean-Loup; Vandaele, Ann-Carine; Neefs, Eddy; Mahieux, Arnaud; Wilquet, Valerie

351

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

352

Evaluation of GEOS-5 sulfur dioxide simulations during the Frostburg, MD 2010 field campaign  

NASA Astrophysics Data System (ADS)

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.; Spinei, E.; Arkinson, H. L.; He, H.

2013-08-01

353

Effects of sulfur dioxide fumigation on photosynthesis, respiration, and chlorophyll content of selected lichens  

SciTech Connect

Four lichens - Parmelia bolliana Mull. Arg., Physcia stellaris (L.) Nyl., Xanthoria fallax (Hepp) Arn., and Physconia grisea (Lam.) Poelt - listed in order of decreasing mesophytism, were fumigated for 4 hr at 0.01, 0.1, 1.0, and 2.5 ppm sulfur dioxide to determine the effects on photosynthesis, respiration, and chlorophyll content. Photosynthesis decreased after fumigation at 1.0 and 2.5 ppm, but significant decreases occurred only after fumigation at 2.5 ppm. Expressed on the basis of per unit weight chlorophyll content, photosynthesis of Physconia grisea was most sensitive followed by that of Xanthoria fallax, Physcia stellaris and Parmelia bolliana. Expressed on the basis of per unit dry weight of lichen sample, photosynthesis of Physconia grisea was most sensitive followed by Xanthoria fallax, Physcia stellaris, and Parmelia bolliana. In both cases, the more xerophytic species were more sensitive. Chlorophyll content in these species was not measurably altered by fumigation. Comparison of chlorophyll a and b absorption spectra peaks for fumigated and control samples indicated that no phaeophytinisation occurred. Insignificant and inconsistent differences in chlorophyll a/b ratios were observed. Respiration of Physcia stellaris and Parmelia bolliana decreased significantly following fumigation with 2.5 ppm SO/sub 2/; both species were more sensitive than Xanthoria fallax. Physconia grisea was not tested for respiratory response. The effects of SO/sub 2/ fumigation on measured metabolic rates differed with the species. Photosynthetic rates of the xerophytic Xanthoria fallax and Physconia gresea were more sensitive than the more mesophytic Parmelia bolliana and Physcia stellaris. In contrast, respiratory sensitivities to SO/sub 2/ fumigation were greater for P. bolliana and P. stellaris.

Beekley, P.K.; Hoffman, G.R.

1981-01-01

354

Cu +2 cation+3,5-dimethyl pyrazole mixture as a corrosion inhibitor for carbon steel in sulfuric acid solution  

Microsoft Academic Search

The inhibition effect of [Cu+2 cation+3,5-dimethyl pyrazole] mixture of different molar ratios on the corrosion of carbon steel in a 0.5M H2SO4 solution was studied using both weight loss and galvanostatic polarization techniques. The inhibiting solutions were analyzed using UVvisible spectrophotometric before and after polarization measurements. The results revealed a complex formation between the two components, which was much more

M Abdallah; M. M El-Naggar

2001-01-01

355

Sulfur emissions  

Microsoft Academic Search

The Environmental Defense Fund challenges a recent conclusion of the Advisory Committee on Oceans and International Environmental and Scientific Affairs ''that nitrogen oxides were the limiting factor in the formation of acids, including sulfuric acid, in acid rain.'' Acceptance of this would mean shifting strategies to reduce acidic sulfur deposition by reducing regional sulfur dioxide SO emissions in eastern North

1985-01-01

356

Investigation of the sensitivity, selectivity, and reversibility of the chemically-sensitive field-effect transistor (CHEMFET) to detect nitrogen dioxide, dimethyl methylphosphonate, and boron trifluoride. Master's thesis  

SciTech Connect

This study investigated the sensitivity, selectivity, and reversibility of a chemically-sensitive field-effect transistor (CHEMFET) gas microsensor. Various physical operating parameters were tested to determine which produced the most significant sensitivity, selectivity, and reversibility which were computed from response changes generated from electrical conductivity modulations when exposed to challenge gases. The variable operating parameters included: thinfilm material, film thickness, challenge gas specie, challenge gas concentration, and operating temperature. Copper phthalocyanine and lead phthalocyanine were used as thin films to detect the following challenge gases: nitrogen dioxide, dimethyl methylphosphonate, boron trifluoride, methanol, carbon monoxide, vinyl chloride, and trichloroethylene. Tests revealed that copper phthalocyanine was the most sensitive to dimethyl methylphosphonate and boron trifluoride, whereas lead phthalocyanine was the most sensitive to the remaining challenge gases. The CHEMFET was selective to the binary challenge gas combinations. The films were most selective for nitrogen dioxide. The CHEMFET was fully reversibly, and the time duration for full reversibility increased with increasing challenge gas concentrations and increasing time of exposure.

Hauschild, N.T.

1993-09-01

357

Detection of the Gaseous Pollutant Sulfur Dioxide Using Current Tunable Pb(1-x) SnM(x) Te Diode Lasers.  

PubMed

Current tunable semiconductor lasers of Pb(1-x)Sn(x)Te have been used to investigate the ir spectrum of sulfur dioxide at high resolution near 1130 cm(-1). The diode lasers emit radiation in a line of width <10(-5) cm(-1) thus providing much higher resolution than has been possible with the best grating spectrometer. The effects of self-broadening and broadening by nitrogen to a pressure of 760 Torr are presented, and some characteristics of the laser source such as stability and reproducibility are discussed. PMID:20119184

Antcliffe, G A; Wrobel, J S

1972-07-01

358

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

359

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

360

Evaluation of satellite derived sulfur dioxide measurements for volcano monitoring during the 2009 Redoubt eruption (Invited)  

NASA Astrophysics Data System (ADS)

Changes in sulfur dioxide (SO2) emissions frequently precede volcanic eruptions, thus regular monitoring of volcanic SO2 emissions may facilitate more accurate eruption forecasting. Recent advancements in detection capabilities by both ultraviolet and infrared satellite sensors have made satellite remote sensing a viable tool for monitoring SO2 emissions during volcanic unrest; however, the extent to which satellite-generated SO2 data concur with traditional airborne SO2 measurements requires investigation. During the recent eruption of Redoubt Volcano, Alaska, which commenced in March 2009, SO2 emissions were detected on a near-daily basis by the Ozone Monitoring Instrument (OMI) on the Aura satellite. During explosive events, SO2 was also detected by the Atmospheric Infrared Sounder (AIRS) on the Aqua satellite. Preliminary satellite-derived SO2 burdens from the first three months of the eruption range from 80,000 tonnes during explosive activity to 3000 tonnes during passive degassing. These satellite measurements, several of which coincided with airborne SO2 measurements conducted by the Alaska Volcano Observatory (AVO), provide a rare opportunity to evaluate the efficacy of satellite SO2 measurements for volcano monitoring in Alaska, where remote sensing of volcanic unrest is an invaluable tool. Satellite-derived SO2 burdens have supplemented approximately weekly airborne measurements of SO2 emissions from Redoubt since March 2009; however, direct integration of the two datasets has been hindered because satellite and airborne measurements are reported as instantaneous SO2 mass and daily SO2 emission rate, respectively. Integration of satellite and airborne measurements would provide a more complete record of SO2 emissions because satellites detect SO2 during explosive, ash-rich eruptions when airborne measurements are not possible, and measure SO2 on a daily basis, a greater temporal resolution than is feasible by airborne methods alone. This will result in improved constraints on the volatile budget throughout an eruption, which may permit more effective eruption forecasting. Herein, we report OMI and AIRS SO2 measurements during the 2009 Redoubt eruption, which featured explosive eruptions to stratospheric altitudes and tropospheric gas plumes to altitudes of approximately three kilometers. We test a simple algorithm to convert the OMI SO2 burdens to SO2 emission rates for direct comparison with airborne measurements, and compare temporally and spatially coincident satellite and airborne SO2 measurements to evaluate the accuracy of OMI SO2 column amounts and derived burdens.

Lopez, T. M.; Carn, S. A.; Webley, P.; Pfeffer, M. A.; Doukas, M. P.; Kelly, P. J.; Werner, C. A.; Prata, F.; Schneider, D. J.; Cahill, C. F.

2009-12-01

361

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

362

Thermodynamic analysis of low-temperature carbon dioxide and sulfur dioxide capture from coal-burning power plants  

NASA Astrophysics Data System (ADS)

We discuss the possibility of capturing carbon dioxide from the flue gas of a coal-fired electrical power plant by cryogenically desublimating the carbon dioxide and then preparing it for transport in a pipeline to a sequestration site. Various other means have been proposed to accomplish the same goal. The problem discussed here is to estimate the energy penalty or parasitic energy loss,' defined as the fraction of electrical output that will be needed to provide the refrigeration and that will then not be deliverable. We compute the energy loss (7.9-9.2% at 1 atm) based on perfect Carnot efficiency and estimate the achievable parasitic energy loss (22-26% at 1 atm) by incorporating the published coefficient of performance values for appropriately sized refrigeration or liquefaction cycles at the relevant temperatures. The analyses at 1 atm represent a starting point for future analyses using elevated pressures.

Swanson, Charles E.; Elzey, John W.; Hershberger, Robert E.; Donnelly, Russell J.; Pfotenhauer, John

2012-07-01

363

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

364

Increased thiol biosynthesis of transgenic poplar expressing a wheat O -acetylserine(thiol) lyase enhances resistance to hydrogen sulfide and sulfur dioxide toxicity  

Microsoft Academic Search

O-acetylserine(thiol) lyase (OASTL), a key enzyme of the plant sulfur assimilatory pathway, catalyses the formation of cysteine\\u000a from sulfide and O-acetylserine. Transgenic hybrid poplar (Populus sieboldiנP. grandidentata Y63) plants expressing cys1, encoding a wheat cytosolic OASTL, were developed in order to examine the role of this enzyme in thiol production following\\u000a hydrogen sulfide or sulfur dioxide exposure and in the

Michimi Nakamura; Masato Kuramata; Isao Kasugai; Midori Abe; Shohab Youssefian

2009-01-01

365

Evaluation of lithium sulfur dioxide batteries. US Army Communications - Electronics Command and US Army Electronics Research and Development Command, Fort Monmouth, New Jersey, 1 May1 October 1984. Technical report, 1 May1 OctobeR 1984  

Microsoft Academic Search

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

Rosak

1985-01-01

366

40 CFR 60.42b - Standard for sulfur dioxide (SO2).  

Code of Federal Regulations, 2013 CFR

...firing only very low sulfur oil, gaseous fuel, a mixture of...area and that combust coal, oil, or natural gas shall not discharge...the affected facility combusts oil or natural gas. (4) As an alternative to meeting the...

2013-07-01

367

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

368

On the formation of carbonyl sulfide in the reduction of sulfur dioxide by carbon monoxide on lanthanum oxysulfide catalyst: A study by XPS and TPR/MS  

SciTech Connect

Both the X-ray photoelectron spectroscopy (XPS) and temperature-programmed reaction, coupled with mass spectrometry (TPR/MS), are used to study the formation of carbonyl sulfide in the reduction of sulfur dioxide on lanthanum oxysulfide catalyst. It was found that the lattice sulfur of the oxysulfide is released and reacts with carbon monoxide to form carbonyl sulfide when the oxysulfide is heated. The oxysulfide is postulated to form sulfur vacancies at a temperature lower than that for the formation of carbonyl sulfide and atomic sulfur is released in the process. The atomic sulfur can either enter the gas phase and leave the oxysulfide catalyst or react with carbon monoxide to form carbonyl sulfide.

Lau, N.T.; Fang, M. [Hong Kong Univ. of Science and Technology, Clear Water Bay (Hong Kong). Applied Technology Center

1998-10-25

369

Productivity of field-grown soybeans exposed to acid rain and sulfur dioxide alone and in combination  

SciTech Connect

Sulfur dioxide (SO/sub 2/)-fumigated and unfumigated field plots of soybeans (Glycine max cv. Wells) were exposed to acid (pH 3.1) or control (pH approx. =5.3) precipitation simulants to determine effects on growth and productivity. The precipitation simulants were applied at approximately 5-day intervals in July and August with a total of 3.4 cm applied in 1977 and 4.5 cm in 1978. Sulfur dioxide fumigations of approx. =4-hour durations were performed 24 times in 1977 and 17 times in 1978, resulting in an average fumigation concentration of 0.79 ppm (89.6 ppmin equilibriumhour dose) SO/sub 2/ the 1st year and 0.19 ppm (13.5 ppmin equilibriumhour) the 2nd. The acid precipitation simulant produced no statistically significant effect on seed yield in either year and a 4% increase in seed size in 1978. The simulated acid rain may have contributed to the nutritional requirements of soybeans by providing S and N during the critical pod-filling stage. Sulfur dioxide exposure decreased seed yields in both 1977 and 1978 by >35 and 12%, respectively. Accelerated senescence, as suggested by increased leaf fall, may be responsible for the decreased yield in the SO/sub 2/-exposed plants. The SO/sub 2/ exposure appeared to negate the positive acid rain effect on seed size observed in 1978, when the two treatments were combined. Acid precipitation apparently increased the reduction in seed weight resulting from SO/sub 2/ exposure in 1977. Although visible injury was induced by acid rain exposure in a chamber study, only a small percentage (<1%) of tissue was affected and there was no apparent effect on plant growth. The results of these studies suggest that the possibility for harmful effects on soybean yield from acid precipitation of a magnitude used in this study are minimal; however, soybean yields may be decreased by SO/sub 2/ exposures

Irving, P.M. (Univ. of Wisconsin, Milwaukee); Miller, J.E.

1981-10-01

370

Studies of tolerance of certain succulent plants to ambient air sulfur dioxide levels in urban environments of a city in India a new approach  

Microsoft Academic Search

The paper deals with the studies of the ambient air quality with reference to SO2 and succulent plants in two types of urban situations in Hyderabad (India), in low polluted residential?cum?industrial areas and high polluted industrial areas. The sulfur dioxide tolerance index (STI) was used to obtain the sensitivity of plants and their tolerance capacities. The index provides a relative

S. H. Raza; G. Shylaja

1992-01-01

371

Formation of Secondary Organic Aerosol from Irradiated a -Pinene/Tolueme/NOx Mixtures and the Effect of Isoprene and Sulfur Dioxide  

EPA Science Inventory

Secondary organic aerosol (SOA) was generated by irradiating a series of a-pinene/toluene/NOx mixtures in the absence and presence of isoprene or sulfur dioxide. The purpose of the experiment was to evaluate the extent to which chemical perturbations to this base-case (a-pinene/...

372

Field investigation of sulfur dioxide washout from the plume of a large coal-fired power plant by natural precipitation. Final report  

Microsoft Academic Search

An experimental investigation was conducted in western Pennsylvania to measure the sulfur dioxide washout by natural precipitation from the plume of a large, coal-fired power plant. This information is necessary in assessing the extent of depletion from the diffusion plume and in evaluating the possible consequences arising from deposition at the surface. The field investigation extended over three one-month periods

J. M. Hales; J. M. Thorp; M. A. Wolf

1971-01-01

373

Determination of equilibrium data for sulfur dioxide-water systems in the range of low concentrations of SO[sub 2  

SciTech Connect

Various methods for determining equilibrium data for sulfur dioxide-water systems were analyzed. Large differences are encountered in the literature data for the range of low concentrations of SO[sub 2]. An algorithm proposed by Pearson et al. for determining equilibrium data in this range is presented and demonstrated by an example.

Mackowiak, J. (Envicon Engineering, Dinslaken (Germany)); Koziol, A.

1993-07-01

374

Investigation of the Capture of Sulfur Dioxide and Oxygen by Condensation of Water in Droplets. Progress Report, September 1, 1977--November 30, 1978.  

National Technical Information Service (NTIS)

The first phase of this research involved the measurement of the uptake of sulfur dioxide and other gases by large, single water droplets growing by condensation or evaporating. Gases were mixed in a humid nitrogen stream and allowed to flow past a suspen...

M. J. Matteson

1978-01-01

375

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

Microsoft Academic Search

The total flux of sulfur dioxide from the Italian volcanoes Etna, Stromboli, and Vulcano was determined using the differential absorption lidar technique. The measurements were performed from an oceanographic research ship making traverses under the volcanic plumes with the lidar system sounding vertically. By combining the integrated gas concentration over the plume cross section with wind velocity data, it was

H. Edner; P. Ragnarson; S. Svanberg; E. Wallinder; R. Ferrara; R. Cioni; B. Raco; G. Taddeucci

1994-01-01

376

Conformational behavior of dimethyl 5-methyl-1H,3H-pyrrolo[1,2-c][1,3]thiazole-6,7-dicarboxylate 2,2-dioxide isolated in low-temperature matrixes.  

PubMed

The structure of dimethyl 5-methyl-1H,3H-pyrrolo[1,2-c][1,3]thiazole-6,7-dicarboxylate 2,2-dioxide (PTD) was investigated in low-temperature noble gas matrixes (Ar, Kr, Xe), amorphous solid, and the crystalline state by infrared spectroscopy and computational methods. The geometry of PTD conformers is defined by the orientation of two methyl ester groups, which may adopt pseudo-trans or pseudo-cis positions in relation to the pyrrolo-thiazole system. For both methyl ester groups, the latter arrangement was predicted by the calculations to be energetically the most favorable in the isolated molecule. The envelope form of the thiazolidine ring is present in all conformers, with the sulfur atom placed in the apex position, while the pyrrole ring is almost planar. Three types of conformers differing in the orientation of the methyl ester groups relative to the pyrrolo-thiazole system (cis/cis, trans/cis, cis/trans) were identified in the matrixes. The cis/cis forms were found to be the most stable ones in both gaseous state and argon matrixes. On the other hand, the more polar trans/cis forms were found to be stabilized in the more polarizable krypton and xenon matrixes as well as in the neat amorphous and crystalline phases. On the basis of annealing experiments, performed in argon and xenon matrixes up to 35 and 68 K, respectively, conformational changes preceding the aggregation of the compound are suggested. PMID:16706411

Kaczor, A; Pinho e Melo, T M V D; Soares, M I L; Fausto, R

2006-05-25

377

Lung function among employees of a copper mine smelter: lack of effect of chronic sulfur dioxide exposure  

SciTech Connect

Lung function among 599 white male employees of a southeastern Tennessee copper mine/smelter operation was compared according to smoking history and occupational experience. The job categories compared included employees with work histories in low sulfur dioxide (SO/sub 2/) environments (both underground mining and non-mining), in high SO/sub 2/ exposure work areas, and in those with transient exposure to SO/sub 2/. Miners with low SO/sub 2/ exposure were found to have lower lung function indices (both FVC and FEV/sub 1/) than did employees in other job categories. Smoking history was strongly associated with low FEV/sub 1/. After adjusting for smoking history, cumulative long-term exposure to SO/sub 2/ was not demonstrated to contribute to decreased lung function.

Federspiel, C.F.; Layne, J.T.; Auer, C.; Bruce, J.

1980-07-01

378

Interaction of Two Air Pollutants, Sulfur Dioxide and Ozone on Lung Functions.  

National Technical Information Service (NTIS)

Increased use of high sulfur fuels with consequent potential for increased SO2 levels in the atmosphere has led to renewed interest in the effects of SO2 on man's physiological functions. The effects on young males of 0.4 ppm SO2 and 0.4 ppm ozone alone a...

L. J. Folinsbee S. M. Horvath

1978-01-01

379

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...

380

Emission of hydrogen sulfide from sulfur dioxide-fumigated pine trees  

Microsoft Academic Search

Pine (Pinus silvestris L.) trees subjected to relatively low concentration of SO in the field emit HS from the needles, as demonstrated by gas chromatographic analysis after preconcentration on a molecular sieve. HS is the only reduced sulfurous compound emitted from SO fumigated leaves. The emission is light and SO concentration dependent. Pine trees in the field and in laboratory

J.-E. Hallgren; S.-A. Fredriksson

1982-01-01

381

Short-term association between sulfur dioxide and daily mortality: the Public Health and Air Pollution in Asia (PAPA) study  

PubMed Central

Sulfur dioxide (SO2) has been associated with increased mortality and morbidity, but few studies were conducted in Asian countries. Previous studies suggest that SO2 may have adverse health effects independent of other pollutants. In the Public Health and Air Pollution in Asia (PAPA) project, the short-term associations between ambient sulfur dioxide (SO2) and daily mortality were examined in Bangkok, Thailand, and three Chinese cities: Hong Kong, Shanghai, and Wuhan. Poisson regression models incorporating natural spline smoothing functions were used to adjust for seasonality and other time-varying covariates. Effect estimates were obtained for each city and then for the cities combined. The impact of alternative model specifications, such as lag structure of pollutants and degree of freedom (df) for time trend, on the estimated effects of SO2 were also examined. In both individual-city and combined analysis, significant effects of SO2 on total non-accidental and cardiopulmonary mortality were observed. An increase of 10 ?g/m3 of 2-day moving average concentrations of SO2 corresponded to 1.00% [95% confidence interval (CI), 0.75-1.24], 1.09% (95% CI, 0.71-1.47), and 1.47% (95% CI, 0.85-2.08) increase of total, cardiovascular and respiratory mortality, respectively, in the combined analysis. Sensitivity analyses suggested that these findings were generally insensitive to alternative model specifications. After adjustment for PM10 or O3, the effect of SO2 remained significant in three Chinese cities. However, adjustment for NO2 diminished the associations and rendered them statistically insignificant in all four cities. In conclusion, ambient SO2 concentration was associated with daily mortality in these four Asian cities. These associations may be attributable to SO2 serving as a surrogate of other substances. Our findings suggest that the role of outdoor exposure to SO2 should be investigated further in this region.

Kan, Haidong; Wong, Chit-Ming; Vichit-Vadakan, Nuntavarn; Qian, Zhengmin

2012-01-01

382

Association of sulfur dioxide exposure with circulatory system deaths in a medium-sized city in Brazil.  

PubMed

There is a demonstrable association between exposure to air pollutants and deaths due to cardiovascular diseases. The objective of this study was to estimate the effects of exposure to sulfur dioxide on mortality due to circulatory diseases in individuals 50 years of age or older residing in So Jos dos Campos, SP. This was a time-series ecological study for the years 2003 to 2007 using information on deaths due to circulatory disease obtained from Datasus reports. Data on daily levels of pollutants, particulate matter, sulfur dioxide (SO2), ozone, temperature, and humidity were obtained from the So Paulo State Environmental Agency. Moving average models for 2 to 7 days were calculated by Poisson regression using the R software. Exposure to SO2 was analyzed using a unipollutant, bipollutant or multipollutant model adjusted for mean temperature and humidity. The relative risks with 95%CI were obtained and the percent decrease in risk was calculated. There were 1928 deaths with a daily mean ( SD) of 1.05 1.03 (range: 0-6). Exposure to SO2 was significantly associated with mortality due to circulatory disease: RR = 1.04 (95%CI = 1.01 to 1.06) in the 7-day moving average, after adjusting for ozone. There was an 8.5% decrease in risk in the multipollutant model, proportional to a decrease of SO2 concentrations. The results of this study suggest that residents of medium-sized Brazilian cities with characteristics similar to those of So Jos dos Campos probably have health problems due to exposure to air pollutants. PMID:22892828

Amancio, C T; Nascimento, L F C

2012-08-16

383

The effect of sulfur dioxide inhalation on visual evoked potentials, antioxidant status, and lipid peroxidation in alloxan-induced diabetic rats.  

PubMed

The aim of the study was to investigate the effect of 10 ppm sulfur dioxide (SO(2)) exposure on visual evoked potentials (VEPs), thiobarbituric acid reactive substances (TBARS), and the activities of Cu,Zn superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in diabetes mellitus. Forty healthy male albino rats, aged 3 months, were divided into four equal groups: control (C), sulfur dioxide + control (CSO(2)), diabetic (D), and sulfur dioxide + diabetic (DSO(2)) groups. Experimental diabetes mellitus was induced by IV injection of alloxane monohydrate in a dose of 50 mg/kg body weight. Ten ppm sulfur dioxide was administered to the animals of sulfur dioxide-exposed groups in an exposure chamber for 1 h/day x 7 days/week x 6 weeks while control and diabetic groups were exposed to filtered air in the same condition. SO(2) exposure, though markedly decreasing retina CAT and GSH-Px activities, significantly increased retina Cu,Zn-SOD activity in the diabetic and nondiabetic groups. In contrast to SO(2)-related increase in the activity of Cu,Zn-SOD, decrease in GSH-Px activity was observed in the brain of those groups. Brain CAT activity was unaltered. SO(2) exposure caused the significant elevation in brain TBARS levels of CSO(2) and DSO(2) groups, whereas only in the retina TBARS level of the CSO(2) group. SO(2) exposure caused the significant prolongations of P(1), N(1), P(2), and P(3) components of VEPs in the nondiabetic and all components of VEPs in the diabetic groups. SO(2) exposure also resulted in significant amplitude reductions in both experimental groups. PMID:10871429

A?ar, A; Kkatay, V; Yargio?lu, P; Aktekin, B; Kipmen-Korgun, S; Gm?l, D; Apaydin, C

2000-08-01

384

[An improved method of measuring sulfur dioxide level in the air].  

PubMed

Out of a set of tested stabilizers used in the photometric detection of sulphur dioxide by fuchs in formaldehyde reactions, trilon B solution was chosen in concentrations 2.5.10(-4)-1.10(-2) M as an absorbent solution and stabilizer. The proposed substitution of natrium tetrachlormercurate by trilon B provided greater stability of sulphur dioxide solution for 7 days and a higher absorbing activity (99.6-100%), avoiding working with highly poisonous substance which would require much time for synthesis. PMID:1794721

Putilina, O N; Kasprik, L V

1991-01-01

385

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

2013-09-21

386

Short-term exposure to 0. 3 ppm nitrogen dioxide does not potentiate airway responsiveness to sulfur dioxide in asthmatic subjects  

SciTech Connect

Whether short-term exposure to low levels of nitrogen dioxide (NO2) enhances airway responsiveness in asthmatic subjects is controversial. Because it is well established that asthma is associated with increased airway responsiveness to another common air pollutant, sulfur dioxide (SO2), we examined whether short-term exposure of asthmatic subjects to 0.3 ppm NO2 potentiates airway responsiveness to inhaled SO2. We exposed nine subjects with clinically stable asthma to 0.3 ppm NO2 or filtered air in an environmental room for 30 min on 2 separate days at least 1 wk apart in a double-blind, randomized fashion. A questionnaire about common symptoms related to inhaled irritants was completed before and immediately after each exposure. Each subject exercised (60 to 80 W) on a cycloergometer during the first 20 min of each exposure. We measured specific airway resistance (SRaw) and FEV1/FVC before, 5 min after, and 1 h after completion of the air or NO2 exposure. The single-breath nitrogen test (SBN2) was also performed before and 1 h after completion of the air or NO2 exposures and closing volume was determined; subsequently, SO2 dose-response curves (0.25 to 4.0 ppm) were performed via a mouthpiece. Each dose of SO2 was inhaled at a minute ventilation of 20 L/min for 4 min and was doubled until SRaw increased by at least 8 U above baseline. The dose of SO2 required to provoke an increase in SRaw of 8 U above baseline was determined by linear interpolation from the dose-response curve (PD8Uso2).

Rubinstein, I.; Bigby, B.G.; Reiss, T.F.; Boushey, H.A. Jr. (Univ. of California, San Francisco (USA))

1990-02-01

387

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

388

Sulfur dioxide flux into leaves of Geranium carolinianum L. : evidence for a nonstomatal or residual resistance  

Microsoft Academic Search

The concurrent exchange of SO and HO vapor between the atmosphere and foliage of Geranium carolinianum was investigated using a whole-plant gas exchange chamber. Total leaf flux of SO was partitioned into leaf surface and internal fractions. The emission rate of SO-induced HS was measured to develop a net leaf budget for atmospherically derived sulfur. Stomatal resistance to SO flux

G. E. Jr. Taylor; D. T. Tingey

1983-01-01

389

Sulfur-dioxide fluxes into different cellular compartments of leaves photosynthesizing in a polluted atmosphere  

Microsoft Academic Search

A computer model is used to analyze fluxes of SO2 from polluted air into leaves and the intracellular distribution of sulfur species derived from SO2. The analysis considers only effects of acidification and of anion accumulation. (i) The SO2 flux into leaves is practically exclusively controlled by the boundary-layer resistance of leaves to gas diffusion and by stomatal opening. At

Agu Laisk; Hardy Pfanz; Ulrich Heber

1988-01-01

390

Fast-regenerable sulfur dioxide absorbents for lean-burn diesel engine emission control  

SciTech Connect

It is known that sulfur oxides contribute significantly and deleteriously to the overall performance of lean-burn diesel engine aftertreatment systems, especially in the case of NOx traps. A Ag-based, fast regenerable SO2 absorbent has been developed and will be described. Over a temperature range of 300oC to 550oC, it absorbs almost all of the SO2 in the simulated exhaust gases during the lean cycles and can be fully regenerated by the short rich cycles at the same temperature. Its composition has been optimized as 1 wt% Pt-5wt%Ag-SiO2, and the preferred silica source for the supporting material has been identified as inert Cabosil fumed silica. The thermal instability of Ag2O under fuel-lean conditions at 230oC and above makes it possible to fast regenerate the sulfur-loaded absorbent during the following fuel-rich cycles. Pt catalyst helps reducing Ag2SO4 during rich cycles at low temperatures. And the chemically inert fumed SiO2 support gives the absorbent long term stability. This absorbent shows great potential to work under the same lean-rich cycling conditions as those imposed on the NOx traps, and thus, can protect the downstream particulate filter and the NOx trap from sulfur poisoning.

Li, Liyu; King, David L.

2010-01-23

391

Removal of hydrogen sulfide and sulfur dioxide from waste gases by AK-Askangel  

SciTech Connect

The objective of this work was to produce an efficient adsorbent for H/sub 2/S and SO/sub 2/, having a high sulfur capacity and good mechanical strength and permitting multiple regeneration. The experiments were performed with modified Askangel (a bentonite clay from the Askan mine, Georgian SSR). Askangel was modified by treatment with iron and copper nitrates or the freshly prepared hydroxides, using a Fe/sub 2/O/sub 3//CuO mass ratio in solution of (1.8-3.4):1 and a bentonite-to-solution ratio of 1:(0.67-1.25).

Kalandiya, A.A.

1987-06-20

392

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

393

[Pollution with sulfur dioxide in an inhabited industrial area. Methodologic problems in monitoring].  

PubMed

The area around Rho and Pero in the north west of the province of Milan is densely populated and highly industrialised. It is also characterised by high levels of sulphur dioxide pollution. During the 1980s it was decided to check the sources of production of the pollutant and its distribution in the area. The main area for improvement was the refinery at Rho where it was aimed to disperse gases at a higher level by raising the chimneys and to use fuel gas in those burners which were connected to lower chimneys. For domestic systems it was decided to diffuse the use of methane as much as possible and limit oil-fired central heating, by statute from the Mayor. In order to rationalise the programme of action the pollution was to be determined for each single area by subdivision of the territory into a grid. By means of a census of all the production sources of sulphur dioxide appropriate data were collected to estimate each area's contribution to pollution. The theoretical hourly quantity of sulphur dioxide was calculated on the basis of the combustion equation. The data were then analysed, in total and divided into component parts, i.e. the type of fuel used, the season of the year and industrial or domestic usage. With Gifford and Hanna's ATDL mathematical model the data thus obtained, together with meteorological variables, were used to simulate the expected effect on the distribution of pollution after carrying out the programmed actions. The simulations foresee a reduction of up to 80% of sulphur dioxide concentrations in the areas of greatest use of liquid fuels. In the territory in question the monitoring of the pollutant was assured by the presence of five fixed positions of continuous survey. These turned out to be useful above all for analysis of the phenomenon over a period of time. In order to study spatial distribution better 374 findings were gathered in the winter of 1985-6 from various points of the territory by means of a mobile instantaneous detector. From these data the average aerial concentration was calculated on a grid, with sides of 500 metres, first for all the observations and then separately for the direction of the wind. Taking into account meteorological factors and the actual hour (during daytime) when the concentration of the pollutant was recorded, it was possible to estimate concentrations by means of linear models in which meteorological parameters were taken as independent variables.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2484496

Macchi, C; Pontoni, H; Pellicciotti, G

394

Retrieval of Vertical Columns of Sulfur Dioxide From SCIAMACHY and OMI: Air Mass Factor Algorithm Development and Validation  

NASA Astrophysics Data System (ADS)

Sulfur dioxide (SO2) is released into the atmosphere as a result of both anthropogenic activities and natural phenomena. SO2 oxidizes rapidly in the atmosphere, leading to aerosol formation and acid deposition. Outstanding questions exist about SO2 emissions and its atmospheric chemistry. Global mapping of atmospheric SO2 concentrations can provide critical information on its emissions and transport and generally improve scientific understanding of its atmospheric chemistry. Here, we present an improved retrieval of sulfur dioxide (SO2) vertical columns from satellite instruments (SCIAMACHY and OMI) that measure solar backscattered UV radiance. Particular attention is devoted to development of a local air mass factor (AMF) algorithm to convert slant columns to vertical columns. For each SCIAMACHY and OMI observation, we calculate an AMF from the relative vertical SO2 distribution (shape factor) determined locally with a 3-D global model of atmospheric chemistry (GEOS-Chem), weighted by altitude-dependent scattering weights computed with a radiative transfer model (LIDORT). Seasonal mean instrument sensitivity to SO2 (AMF) is generally twice as high over ocean than land. Mineral dust can reduce seasonal mean instrument sensitivity by 50%. Mean relative vertical profiles of SO2 simulated with GEOS-Chem and used in the AMF calculation are highly consistent with airborne in situ measurements (INTEX-A and INTEX-B); differences would affect the retrieved SO2 columns by 10%. The retrieved vertical columns are validated (r = 0.9) with coincident airborne in-situ measurements (INTEX-A, INTEX-B, and a campaign over East China). A global uniform AMF would reduce the correlation with aircraft measurements by 0.1 - 0.2. The overall error assessment leads to 45 - 80% errors for yearly averages over the polluted regions. Seasonal mean SO2 columns retrieved from SCIAMACHY and OMI for 2006 are significantly spatially correlated with those from GEOS-Chem, in particular over the United States (r = 0.85 for SCIAMACHY and r = 0.82 for OMI). Differences in other regions such as South Africa, Nigeria, and the Persian Gulf imply underestimates in emissions.

Lee, C.; Martin, R. V.; Donkelaar, A. V.; O'Byrne, G.; Krotkov, N.; Richter, A.; Huey, G.; Holloway, J. S.

2009-05-01

395

Effects of ozone and sulfur dioxide on forage and range species. Volume 2. Under simulated grazing (defoliation). Final report Oct 80-Jun 83  

SciTech Connect

Soft chess and broadleaf filaree plants were grown in pots and exposed to sulfur dioxide in open-top field chambers. Plants were fumigated with 0.0 ppm, 0.1 ppm or 0./sub 2/'' ppm sulfur dioxide for six hours per day, five days per week over an 18 week period. Plants were harvested at week 9, week 13 and week 18. Defoliation treatments were carried out on one-half of the plants. Chronic exposure of nonclipped soft chess to SO/sub 2/ led to reduced yield. Clipping of soft chess usually cancelled the SO/sub 2/ effects. Broadleaf filaree appeared more tolerant to SO/sub 2/ than soft chess.

Younger, V.B.; Shropshire, F.M.; Thompson, C.R.

1983-06-30

396

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

397

Sulfur dioxide in remote occeanic air: Cloud transport of reactive precursors  

NASA Astrophysics Data System (ADS)

Reactive surface emissions of reduced sulfur gases can produce SO2 in the middle and upper troposphere at the levels of 8030 pptv measured high over the remote oceans. We present simulations with a two-dimensional "Staubsauger" or "vacuum cleaner" model that combines a photochemical model with a description of vertical transport of trace species by convective clouds within larger synoptic circulations. Emissions of 20-60 Tg (S)/yr of (CH3)2S, H2S, or CS2, may produce the observed SO2. Roughly equal production rates of SO2 and methane sulfonic acid may be expected. The amount and exact vertical distribution of the SO2 produced remain uncertain: the greatest chemical uncertainties are the reaction yield of SO2 expectable under clean tropospheric conditions and also the liquid-phase removal of SO2, and the oxidation rate. The amount of upper tropospheric SO2 produced depends substantially on the proximity of strong reduced S sources to regions of active convection. However, the character of the solutions we present is invariably distinctly different from those obtained with one- or two-dimensional models employing the eddy-diffusion hypothesis. The results of the model point beyond its original conception, and stress the likely importance of the rainy tropical jungles and mid-latitude industrial regions, since both regions have large sulfur emissions arid frequently active cumulonimbus convection. This process, however, should contribute mainly to upper-tropospheric SO2. Other chemical implications are that tropospheric OH may depend critically on HOOH levels as well as the hydrocarbon and nitrogen oxide cycles. Cloud transport may play an important role in these cycles. The hydroxyl radical concentration depends as much on assumptions regarding HOOH reaction and transport as it does on NO levels.

Chatfield, Robert B.; Crutzen, Paul J.

1984-08-01

398

The solubility of sulfur dioxide in aqueous solutions of sodium chloride and ammonium chloride in the temperature range from 313 K to 393 K at pressures up to 3.7 MPa: experimental results and comparison with correlations  

Microsoft Academic Search

The solubility of sulfur dioxide in aqueous solutions of single solutes sodium chloride and ammonium chloride was measured using a static method at temperatures from 313 K to 393 K and total pressures up to 3.7 MPa corresponding to gas molalities of up to 10 mol\\/kg. Similarily to the system sulfur dioxidewater, also in systems with sodium and ammonium chloride

Jianzhong Xia; Bernd Rumpf; Gerd Maurer

1999-01-01

399

The Effect of Sulfur Dioxide Inhalation on Visual Evoked Potentials, Antioxidant Status, and Lipid Peroxidation in Alloxan-Induced Diabetic Rats  

Microsoft Academic Search

The aim of the study was to investigate the effect of 10 ppm sulfur dioxide (SO2) exposure on visual evoked potentials (VEPs), thiobarbituric acid reactive substances (TBARS), and the activities of Cu,Zn\\u000a superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in diabetes mellitus. Forty healthy male albino\\u000a rats, aged 3 months, were divided into four equal groups: control (C),

A. A?ar; V. Kkatay; P. Yargio?lu; B. Aktekin; S. Kipmen-Korgun; D. Gm?l; C. Apaydin

2000-01-01

400

Influence of the regeneration temperature on the stability of zeolites in the course of cyclic extraction of sulfur dioxide from gases  

SciTech Connect

It was shown that irreversible deactivation of zeolites during cyclic adsorption of sulfur dioxide from gases occurs at the stage of thermal regeneration at temperatures above 200/sup 0/. In order to avoid deactivation of zeolites during cyclic operation the regeneration temperature must be lowered to below 200/sup 0/, with replacement of high-temperature regeneration by low-temperature vacuum-thermal regeneration.

Anurov, S.A.; Lobanov, D.A.; Torocheshnikov, N.S.; Sharova, G.V.

1986-02-10

401

Synthesis of polymer-supported triphenylphosphine oxide complexes of divalent copper and cobalt. A study on their reactivity with sulfur dioxide  

Microsoft Academic Search

Polymer-supported triphenylphosphine oxide dihalide and dinitrate complexes of copper(II) and cobalt(II), MLnX2xH2O (L = polystyryl diphenylphosphine oxide; n =24; x = 07; X = Cl?, Br? and NO3?) have been synthesised and characterised. Their reactions with sulfur dioxide have been investigated in the solid state and in toluene slurries at room temperature. The absorption of SO2 by these complexes and

J. Sanmartn; M. R. Bermejo; C. A. McAuliffe; A. Sousa; M. Fondo; E. Gmez-Frneas

1997-01-01

402

Sulfur dioxide emission flux measurements from point sources using airborne near ultraviolet spectroscopy during the New England Air Quality Study 2004  

Microsoft Academic Search

This work presents measurements of sulfur dioxide (SO2) emission fluxes from point sources using airborne near-ultraviolet (UV) spectroscopy. A Czerny-Turner spectrograph has been optimized to measure SO2 and the oxygen collision complex (O4) in the wavelength region of 286-408 nm from an aircraft platform. The spectrograph was deployed aboard the NOAA WP-3D Orion aircraft during the New England Air Quality

M. L. Melamed; A. O. Langford; J. S. Daniel; R. W. Portmann; H. L. Miller; C. S. Eubank; R. Schofield; J. Holloway; S. Solomon

2008-01-01

403

Sulfur dioxide emission flux measurements from point sources using airborne near ultraviolet spectroscopy during the New England Air Quality Study 2004  

Microsoft Academic Search

This work presents measurements of sulfur dioxide (SO2) emission fluxes from point sources using airborne near-ultraviolet (UV) spectroscopy. A Czerny-Turner spectrograph has been optimized to measure SO2 and the oxygen collision complex (O4) in the wavelength region of 286408 nm from an aircraft platform. The spectrograph was deployed aboard the NOAA WP-3D Orion aircraft during the New England Air Quality

M. L. Melamed; A. O. Langford; J. S. Daniel; R. W. Portmann; H. L. Miller; C. S. Eubank; R. Schofield; J. Holloway; S. Solomon

2008-01-01

404

Intermediate-range grid model and user's guide for atmospheric sulfur dioxide and sulfate concentrations and depositions - Wisconsin Power Plant impact study  

Microsoft Academic Search

The UWATM-SOX computer model was developed to address the acid rain problem on a mesoscale. It predicts sulfur dioxide (SO2) and sulfate (SO4) ambient air concentrations and ground level dry and wet (rain or snow) depositions given certain emission and meteorological input data. It is a time-dependent, cell-type model which numerically solves coupled SO2 and SO4 conservation and mass equations

K. E. Wilkening; K. W. Ragland

1984-01-01

405

Prediction of Ground-Level Concentration of Sulfur Dioxide Downwind of an Industrial Estate in Mauritius Using the ISCST3 Model and Selection of Air Pollution Control Systems  

Microsoft Academic Search

Industries on the island of Mauritius are under increasing pressure from the regulatory authority and from the general public\\u000a to control the air pollution from their boilers and particularly that of sulfur dioxide emissions from fuel oil combustion.\\u000a The measures taken by industry are usually ad hoc in nature, and there has been yet no proper scientific methodology to\\u000a justify

Aruna D. Mahapatra; Toolseeram Ramjeawon

2011-01-01

406

Lung injury in guinea pigs caused by multiple exposures to submicron zinc oxide mixed with sulfur dioxide in a humidified furnace  

Microsoft Academic Search

Sulfur dioxide, water vapor, and ultrafine particles rich in oxides of zinc and other surface?deposited trace elements are important products of coal combustion. In order to study the toxicity of zinc oxide generated under conditions simulating combustion, guinea pigs were exposed in a nose?only apparatus for 3 h on 6 consecutive days to 6 mg\\/m of submicron zinc oxide particles

Michael W. Conner; Hua F. Lam; Adrianne E. Rogers; Shelley Fitzgerald; Mary O. Amdur

1985-01-01

407

The spatial and seasonal variation of nitrogen dioxide and sulfur dioxide in Cape Breton Highlands National Park, Canada, and the association with lichen abundance  

NASA Astrophysics Data System (ADS)

Over 200,000 tourists per year visit Cape Breton Highlands National Park, Nova Scotia, Canada. The forests within the park are home to many rare epiphytic lichens, the species diversity of which has declined in some areas. The primary motivation for this study was to gain insight into the concentrations and potential local and long-range sources of air pollution, but its association with lichen species diversity was also examined. Ogawa passive diffusion samplers were used to measure nitrogen dioxide (NO2) and sulfur dioxide (SO2) in the park at 19 sites in the winter and 20 sites in the summer of 2011. An improvement in the sensitivity of the sampler analytical protocol was developed. The mean concentrations in the park of winter and summer NO2 (0.81 and 0.16 ppb) and SO2 (0.24 and 0.21 ppb) are not at levels known to be phytotoxic to lichen. The NO2 concentrations in winter were significantly (p = 0.001) higher than those in summer whilst the SO2 concentrations did not differ significantly between winter and summer (p = 0.429). Highest NO2 concentrations in both seasons were observed in the Grand Anse Valley, presumably due to the steep road, emissions from the Pleasant Bay community at the foot of the valley and the enclosed topography of this area reducing dispersion of primary emissions. The SO2 concentrations in the park tended to be greater at elevated sites than valley sites, consistent with dispersion from long-range, rather than local, sources for this pollutant. Significant predictors in a multilinear regression for an index of air purity (lichen based measure of air quality) were lichen species number (p = 0.009), forest old growth index (p = 0.001) and distance from roads (p < 0.001) (model R2 = 0.8, model p = 0.004). The study suggests that local sources of pollution (roads emissions) are adversely associated with lichen species diversity in this National Park, compared with long-range transport, and that monitoring programs such as a lichen-based 'index of air purity' can reveal locations where ambient air pollution, although low, is nevertheless at a level that may cause ecological detriment. The implications from this work could be applicable to national parks elsewhere.

Gibson, Mark D.; Heal, Mathew R.; Li, Zhengyan; Kuchta, James; King, Gavin H.; Hayes, Alex; Lambert, Sheldon

2013-01-01

408

In vivo nitrogen dioxide exposure depresses spleen cell in vitro mitogenic responses: effects of sulfur compounds  

SciTech Connect

The in vivo mitogenic responses to lipopolysaccharide or concanavalin A by spleen cells of mice exposed to 20 ppm nitrogen dioxide (NO/sub 2/) for 96 hr, were evaluated. (/sup 3/H)Thymidine incorporation after addition of either mitogen, was significantly lower in spleen cells from acutely NO/sub 2/-exposed mice (NO/sub 2/SC) than from control mice, although cell viability was not affected. T- and B-cell mitogenic responses were inhibited to the same extent by NO/sub 2/ exposure. NO/sub 2/SC responses were protected by the thiol compounds 2-mercaptoethanol, L-cysteine, and selenomethionine. No restoration of mitogenic response was observed after treatment with reduced glutathione. Mechanisms accounting for this in vivo NO/sub 2/ immune toxicity, are discussed in terms of oxidative injury.

Azoulay-Dupuis, E.; Gougerot-Pocidalo, M.A.; Kraus, L.; Moreau, J.

1987-02-01

409

Atmospheric oxidation of flue gases from a partially sulfur dioxide-scrubbed power plant. Study II. [Widows Creek  

SciTech Connect

A series of 12 airborne plume sampling experiments was conducted in the Widows Creek Steam Plant plume. The principal purpose of these experiments was to investigate the atmospheric chemistry of the plume from the wet limestone sulfur dioxide scrubber unit. The average sulfate formation rate determined for these experiments was approximately 1.7 percent per hour (% h/sup -1/). The average nitrate formation rate measured by removal of nitrogen oxides was in excess of 30% h/sup -1/. Little, if any, chemical reactivity difference was observed between the partially scrubbed plume and the totally unscrubbed plume. The data from these measurements indicate the possibility of a strong influence from solar radiation on the atmospheric chemistry. On one day of this study, net ozone production was observed in the plume. This ozone formation in the plume was attributed to the mixing of the power plant plume with a highly polluted air mass possibly transported from a large metropolitan area, such as Chattanooga, Tennessee. The results agree basically with many other recent power plant plume studies and several recently developed mathematical plume simulation models.

Bailey, E.M.; Garber, R.W.; Meagher, J.F.; Bonanno, R.J.; Stockburger, L.

1981-11-01

410

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

411

Effect of sulfur dioxide on the formation mechanism of polychlorinated dibenzodioxin and dibenzofuran in municipal waste combustors  

SciTech Connect

The effect of sulfur dioxides on the formation mechanism of polychlorinated dibenzodioxin (PCDD) and polychlorinated dibenzofuran (PCDF) in the postcombustion, downstream region (500-300 [degrees]C) of a municipal waste combustor (MWC) was investigated. Laboratory experiments simulating the flue gases and particle environment of an MWC examined PCDD production under varying conditions. Effects on the concentration of an organic-chlorinating constituent, Cl[sub 2], through both homogeneous reaction with SO[sub 2] and deactivation of a Cl[sub 2]-forming catalyst [Cu(II)] were examined. Experimental results suggest that the reaction of Cu(II) with SO[sub 2] to form CuSO[sub 4] renders that catalyst less active, decreasing PCDD formation. However, this inactivity is not a result of decreased Cl[sub 2] formation, but rather of reduced ability of Cu(II) to promote a second catalytic step of biaryl synthesis. These findings suggest that the apparent lack of PCDD and PCDF in the emissions from coal-fired combustors may be due to the relatively high concentrations of SO[sub 2]. 26 refs., 7 figs.

Gullett, B.K. (Air and Energy Engineering Research Lab., Research Triangle Park, NC (United States)); Bruce, K.R.; Beach, L.O. (Acurex Corp., Research Triangle Park, NC (United States))

1992-10-01

412

Removal of sulfur dioxide from a continuously operated binary fluidized bed reactor using inert solids and hydrated lime.  

PubMed

Sulfur dioxide pollutant was treated in the laboratory with hydrated lime particles having a mean diameter of 9.1 microm in a continuously operating binary fluidized bed reactor also containing inert sand particles with sizes varying from 500 to 590 microm. The influence of temperature (500, 600, 700 and 800 degrees C) on the reaction medium, of the superficial velocity of the gas (0.8, 1.0 and 1.2 m/s), and of the Ca/S molar ratio (1, 2 and 3) on the SO2 removal efficiency were investigated for an inflow gas concentration of 1000 ppm and an initially static bed height of 10.0 cm. The pollutant removal efficiency proved to depend on the temperature and the velocity of the gaseous flow and was strongly influenced by the Ca/S molar ratio. The maximum efficiency of 97.7% was achieved at a temperature of 700 degrees C, a Ca/S ratio of 3 and a velocity of 0.8 m/s. The lime particles' mean residence time was determined by an indirect method, which consisted of integrating the gas concentration curves normalized with respect to time. Based on a calculation of the critical transition velocities, it was concluded that the reactor operated in a bubbling regime under each condition investigated here. PMID:15177758

Pisani, R; de Moraes, D

2004-06-18

413

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

2011-09-02

414

Oxygen-18 study of nonaqueous-phase oxidation of sulfur dioxide  

NASA Astrophysics Data System (ADS)

In a study of the mechanisms of atmospheric sulfate formation, oxygen isotope ratios were measured in sulfates and in the SO 2 and water vapors from which they were formed, in the absence of liquid water. In a 3-? glass chamber, SO 2 and water vapor of various 18O contents were isotopically equilibrated, and then air oxidation of the SO 2 to sulfate was performed by four different methods: high-voltage discharges, NO 2 addition, gamma irradiation and adsorption on activated charcoal. Isotopic equilibration between SO 2 and water vapor proceeded rapidly, resulting in a strong dependence of the ?18O of the sulfate on that of the water vapor. Oxidation of SO 2 on dry charcoal occurred through the apparent formation of 9-oxygen, 2-sulfur, chemisorbed molecules which decomposed to sulfate in leach water. The ?18OSO2-4vs?18OH2Orelationships observed for these four nonaqueous-phase oxidations of SO 2 to sulfate, together with those in three previously reported aqueous-phase oxidations ( Fe 3+-catalyzed air oxidation, charcoal-catalyzed air oxidation and H 2 O 2 oxidation), were compared to sulfate in rain and snow collected at Argonne, IL. The ?18O of sulfate in precipitation water was significantly higher than could be accounted for by any of the several oxidation reactions that were investigated as possible pathways in the formation of secondary sulfates in the atmosphere, either singly or in combination.

Holt, B. D.; Cunningham, P. T.; Engelkemeir, A. G.; Graczyk, D. G.; Kumar, R.

415

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

416

Solubility of sulfur dioxide in aqueous solutions of acetic acid, sodium acetate, and ammonium acetate in the temperature range from 313 to 393 K at pressures up to 3.3 MPa: Experimental results and comparison with correlations\\/predictions  

Microsoft Academic Search

In many chemical plants, for example in coal gasification processes or desulfurization equipment, sour gas absorption columns and sour water strippers are used to remove weak electrolyte gases like sulfur dioxide, hydrogen cyanide, hydrogen sulfide or carbon dioxide from aqueous solutions. The basic design of such equipment requires physico-chemical models to describe the phase equilibrium as well as the caloric

Jianzhong Xia; Bernd Rumpf; Gerd Maurer

1999-01-01

417

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

NASA Astrophysics Data System (ADS)

The presented study aims to investigate the gaseous fluoride and sulfur dioxide (SO2) pollution level in the kitchen, traditional flue-curing barn and outdoor environment and to find economically feasible method to reduce fluorine and sulfur release. The gaseous fluoride and SO2 concentrations in air of outdoor environment, kitchen and traditional flue-curing barn were determined in 56 households in coal-burning endemic fluorosis areas of Zhaotong. Among these, 21 households in Yujiawan Village, Zhenxiong County, Zhaotong City were chosen for this experiment to reduce gaseous fluoride and SO2 concentration in traditional flue-curing barn air by using calcined dolomitic siliceous limestone (CDSL) instead of clay mixed with coal. The result showed that: (1) gaseous fluoride and SO2 concentration in the outdoor air in Mangbu Township area was 0.51?gdm?2?day and <0.05mgm?3, respectively and in Xiaolongdong Township was 2.7?gdm?2day and <0.05mgm?3, respectively while in Zhaotong City these concentration were lower than the ambient air standard (3?gdm?2?day and 0.5mgm?3, respectively). (2) The indoor gaseous fluoride concentration (3.7?gm?3) in air of kitchen with the improved coal stove was within the reference value (10?gm?3); SO2 concentration (0.94mgm?3) in kitchen air had decline, but its concentration was still higher than indoor air quality standard (0.5mgm?3). (3) Average concentration of gaseous fluoride and SO2 in air of traditional flue-curing barn of Xiaolongdong Township was 7.2?gm?3 and 6.8mgm?3 respectively, and in Yujiawan village were 10.1?gm?3 and 14.4mgm?3, respectively. (4) After using the calcined dolomitic siliceous limestone instead of clay mixed with coal, gaseous fluoride and SO2 concentration in the traditional flue-curing barn air decreased of 45% and 91%, respectively. The gaseous fluoride and SO2 pollution in the traditional flue-curing barn is very serious. The corn and chili baked by open stoves in traditional flue-curing barn (baking room) was also seriously polluted by fluoride and sulfur. After using the calcined dolomitic siliceous limestone instead of clay mixed with coal, gaseous fluoride and SO2 concentration in the traditional flue-curing barn air have declined markedly. The way of adding calcined dolomitic siliceous limestone instead of clay as a binder for briquette-making is an economically feasible way to control the indoor pollution of fluorine and sulfur in coal-burning endemic in Zhaotong, Yunnan.

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

2013-10-01

418

Fundamental study of ammonia-sulfur dioxide reactions to form solid particles. Final report  

SciTech Connect

The effects of reaction residence time, presence of inert particles and moisture content on the SO{sub 2} removal and the product particle size distributions have been determined. Results indicated that both gas phase and particle phase reach equilibria in a very short time. The presence of inert particles increases the SO{sub 2} removal efficiency slightly, with a greater increase in removal efficiency at higher surface areas. Moisture content is the most important parameter affecting SO{sub 2} removal. Increasing the moisture content from 1.6% to 6.4% by volume results in a 30% increase of the SO{sub 2} removal at a reaction temperature of 51{degree}C. The products at near anhydrous conditions were concluded to be NH{sub 3}SO{sub 2}, (NH{sub 3}){sub 2}SO{sub 2} and (NH{sub 4}){sub 2}S{sub 2}O{sub 5}. While the products at humid conditions could be either the 1:1 sulfites, NH{sub 4}HSO{sub 3} and (NH{sub 4}){sub 2}S{sub 2}O{sub 5}, or the 2:1 sulfites, (NH{sub 4}){sub 2}SO{sub 3} and (NH{sub 4}){sub 2}SO{sub 3} {minus}H{sub 2}O, or a mixture of the 1:1 and 2:1 sulfite. Those sulfite particles could subsequently oxidize to form the more stable sulfate particles. A gas-to-particle formation model has been developed to simulate the NH{sub 3}-SO{sub 2} system in the presence and absence of seed aerosols at trace water conditions. This model accounts for simultaneous nucleation, coagulation, condensation and chemical reaction. The applicability of utilizing ammonia injection to a flue gas system has been discussed in terms of two possible removal schemes. One utilizes ammonia injection alone and the other is in conjunction with the injection of Ca(OH){sub 2} slurry in a spray dryer system. Both schemes have the potential of achieving over 90% SO{sub 2} removal from power plants burning high-sulfur coals.

Biswas, P.; Bai, H. [Cincinnati Univ., OH (United States). Dept. of Civil and Environmental Engineering

1994-01-18

419

Solubility of sulfur dioxide in aqueous solutions of acetic acid, sodium acetate, and ammonium acetate in the temperature range from 313 to 393 K at pressures up to 3.3 MPa: Experimental results and comparison with correlations/predictions  

SciTech Connect

In many chemical plants, for example in coal gasification processes or desulfurization equipment, sour gas absorption columns and sour water strippers are used to remove weak electrolyte gases like sulfur dioxide, hydrogen cyanide, hydrogen sulfide or carbon dioxide from aqueous solutions. The basic design of such equipment requires physico-chemical models to describe the phase equilibrium as well as the caloric properties of such mixtures. New experimental results for the solubility of sulfur dioxide in aqueous solutions of single solutes acetic acid, sodium acetate and ammonium acetate at temperatures from 313 to 393 K and total pressures up to 3.3 MPa are reported. Similar to the system sulfur dioxide-water, also in such systems with acetic acid and sodium or ammonium acetate a second (sulfur dioxide rich) liquid phase is observed at high sulfur dioxide concentrations. A model to describe the phase equilibrium is presented and calculated (i.e., predicted as well as correlated) phase equilibria are compared to the new experimental data.

Xia, J.; Rumpf, B.; Maurer, G. [Univ. Kaiserslautern (Germany). Lehrstuhl fuer Technische Thermodynamik

1999-03-01

420

Sulfur X-ray absorption and vibrational spectroscopic study of sulfur dioxide, sulfite, and sulfonate solutions and of the substituted sulfonate ions X3CSO3- (X = H, Cl, F).  

PubMed

Sulfur K-edge X-ray absorption near-edge structure (XANES) spectra have been recorded and the S(1s) electron excitations evaluated by means of density functional theory-transition potential (DFT-TP) calculations to provide insight into the coordination, bonding, and electronic structure. The XANES spectra for the various species in sulfur dioxide and aqueous sodium sulfite solutions show considerable differences at different pH values in the environmentally important sulfite(IV) system. In strongly acidic (pH < approximately 1) aqueous sulfite solution the XANES spectra confirm that the hydrated sulfur dioxide molecule, SO2(aq), dominates. The theoretical spectra are consistent with an OSO angle of approximately 119 degrees in gas phase and acetonitrile solution, while in aqueous solution hydrogen bonding reduces the angle to approximately 116 degrees . The hydration affects the XANES spectra also for the sulfite ion, SO32-. At intermediate pH ( approximately 4) the two coordination isomers, the sulfonate (HSO3-) and hydrogen sulfite (SO3H-) ions with the hydrogen atom coordinated to sulfur and oxygen, respectively, could be distinguished with the ratio HSO3-:SO3H- about 0.28:0.72 at 298 K. The relative amount of HSO3- increased with increasing temperature in the investigated range from 275 to 343 K. XANES spectra of sulfonate, methanesulfonate, trichloromethanesulfonate, and trifluoromethanesulfonate compounds, all with closely similar S-O bond distances in tetrahedral configuration around the sulfur atom, were interpreted by DFT-TP computations. The energy of their main electronic transition from the sulfur K-shell is about 2478 eV. The additional absorption features are similar when a hydrogen atom or an electron-donating methyl group is bonded to the -SO3 group. Significant changes occur for the electronegative trichloromethyl (Cl3C-) and trifluoromethyl (F3C-) groups, which strongly affect the distribution especially of the pi electrons around the sulfur atom. The S-D bond distance 1.38(2) A was obtained for the deuterated sulfonate (DSO3-) ion by Rietveld analysis of neutron powder diffraction data of CsDSO3. Raman and infrared absorption spectra of the CsHSO3, CsDSO3, H3CSO3Na, and Cl3CSO3Na.H2O compounds and Raman spectra of the sulfite solutions have been interpreted by normal coordinate calculations. The C-S stretching force constant for the trichloromethanesulfonate ion obtains an anomalously low value due to steric repulsion between the Cl3C- and -SO3 groups. The S-O stretching force constants were correlated with corresponding S-O bond distances for several oxosulfur species. PMID:17784748

Risberg, Emiliana Damian; Eriksson, Lars; Mink, Jnos; Pettersson, Lars G M; Skripkin, Mikhail Yu; Sandstrm, Magnus

2007-09-05

421

Volcanic sulfur dioxide plume forecasts based on UV satellite retrievals for the 2011 Grmsvtn and the 2010 Eyjafjallajkull eruption  

NASA Astrophysics Data System (ADS)

sulfur dioxide plumes released by the eruptions of the Icelandic volcanoes Eyjafjallajkull in May 2010 and Grmsvtn in May 2011 were studied using satellite observations from the Second Global Ozone Monitoring Experiment (GOME-2), Ozone Monitoring Instrument (OMI), and Scanning Imaging Absorption Spectrometer for Atmospheric Chartography and modeled with the Integrated Forecasting System of the European Centre for Medium-Range Weather Forecasts (ECMWF). The retrievals of SO2 total columns (TCSO2) were (i) used to estimate emission rate and injection height of the two eruptions and (ii) assimilated with ECMWF's four-dimensional variational data assimilation algorithm to obtain initial conditions for subsequent forecasts. The OMI retrievals provided the highest plume observation values, and GOME-2 had the best coverage. The emission parameters were estimated by comparing TCSO2 observations with an ensemble of test tracers injected at different heights. The applied methodology led to emission estimates of 0.25 Tg over 20 days in May 2010 and 0.32 Tg over 2 days in May 2011. The SO2 analyses produced by assimilating GOME-2 TCSO2 retrievals captured the plume maxima well but exaggerated the plume area. The injection height estimate was used during the assimilation to determine the height of the assimilated plume. Plume forecasts were evaluated by means of hit-rate and plume-size statistics for different TCSO2 thresholds. Plume forecasts using either the emission parameters or the SO2 analyses as initial conditions agreed reasonably with the observations, but using both led to the best forecast performance. The initialization with SO2 analysis fields improved, in particular, the forecast of the Grmsvtn plume after the end of the eruption. The developed forecast and assimilation system can be applied for near-real-time forecasting of volcanic SO2 plumes.

Flemming, Johannes; Inness, Antje

2013-09-01

422

Pre-exposure to sulfur dioxide attenuates most allergic reactions upon trimellitic anhydride challenge in sensitized Brown Norway rats.  

PubMed

Irritant-induced inflammation of the airways may aggravate respiratory allergy induced by chemical respiratory allergens. Therefore, it was studied whether airway irritation by sulfur dioxide (SO(2)) would enhance respiratory allergic reactions to trimellitic anhydride (TMA), using a rat model. Brown Norway (BN) rats were topically sensitized, subsequently exposed for a single time or repeatedly to 300 ppm SO(2), and challenged by inhalation to a distinctly irritating or minimally irritating concentration of TMA after the (last) SO(2) exposure. Repeated exposure to SO(2) alone reduced breathing frequency during exposure, and caused epithelial alterations including hyperplasia and squamous metaplasia, and infiltration of polymorphonuclear inflammatory cells into nasal tissues, larynx, trachea, and bronchi/bronchioli. Histopathological changes were less prominent after 1 day of SO(2) exposure. Repeated pre-exposure to SO(2) reduced the number of TMA-induced apnoeas, in an SO(2) exposure duration-dependent manner. This effect of SO(2) on TMA-induced functional allergic reactions (apnoeas) was distinct only when the TMA challenge concentration was not too irritating itself. Repeated pre-exposure to SO(2) reduced TMA-induced laryngeal ulceration, goblet-cell hyperplasia, and inflammation in the lungs in most animals, regardless of the TMA challenge concentration. The SO(2)-induced replacement of normal respiratory epithelium by less sensitive, squamous epithelium may offer an explanation for the, unexpected, reduced allergic manifestation. However in a few animals, SO(2) appeared to facilitate TMA-induced irritation, probably due to incomplete protection. Overall, SO(2) exposure of TMA-sensitized rats reduced TMA-related allergic respiratory responses in most animals. PMID:20067440

Arts, Josje H E; Jacobs, Erik J; Kuper, C Frieke

2010-02-01

423

Risk of Asthmatic Episodes in Children Exposed to Sulfur Dioxide Stack Emissions from a Refinery Point Source in Montreal, Canada  

PubMed Central

Background Little is known about the respiratory effects of short-term exposures to petroleum refinery emissions in young children. This study is an extension of an ecologic study that found an increased rate of hospitalizations for respiratory conditions among children living near petroleum refineries in Montreal (Canada). Methods We used a time-stratified casecrossover design to assess the risk of asthma episodes in relation to short-term variations in sulfur dioxide levels among children 24 years of age living within 0.57.5 km of the refinery stacks. Health data used to measure asthma episodes included emergency department (ED) visits and hospital admissions from 1996 to 2004. We estimated daily levels of SO2 at the residence of children using a) two fixed-site SO2 monitors located near the refineries and b) the AERMOD (American Meteorological Society/Environmental Protection Agency Regulatory Model) atmospheric dispersion model. We used conditional logistic regression to estimate odds ratios associated with an increase in the interquartile range of daily SO2 mean and peak exposures (31.2 ppb for AERMOD peaks). We adjusted for temperature, relative humidity, and regional/urban background air pollutant levels. Results The risks of asthma ED visits and hospitalizations were more pronounced for same-day (lag 0) SO2 peak levels than for mean levels on the same day, or for other lags: the adjusted odds ratios estimated for same-day SO2 peak levels from AERMOD were 1.10 [95% confidence interval (CI), 1.001.22] and 1.42 (95% CI, 1.101.82), over the interquartile range, for ED visits and hospital admissions, respectively. Conclusions Short-term episodes of increased SO2 exposures from refinery stack emissions were associated with a higher number of asthma episodes in nearby children.

Smargiassi, Audrey; Kosatsky, Tom; Hicks, John; Plante, Celine; Armstrong, Ben; Villeneuve, Paul J.; Goudreau, Sophie

2009-01-01

424

Sulfur dioxide derivatives improve the vasorelaxation in the spontaneously hypertensive rat by enhancing the vasorelaxant response to nitric oxide.  

PubMed

The present study was designed to explore the role of sulfur dioxide (SO(2)) in the regulation of vasorelaxation in the spontaneously hypertensive rat (SHR). Twenty-two Wistar rats and 15 SHRs were divided randomly into the following groups: Wistar-Kyoto (WKY) control (n = 8), WKY+Na(2)SO(3)/NaHSO(3) (n = 8), WKY+L-aspartic acid-?-hydroxamate (HDX) (n = 6), SHR control (n = 8) and SHR+Na(2)SO(3)/NaHSO(3) (n = 7). Their blood pressure in vivo was measured by tail plethysmography. The vasorelaxant response of the thoracic aorta to acetylcholine (Ach) and sodium nitroprusside (SNP) in all rats was tested, respectively, in the experiment. At the same time, the SO(2) content of the WKY aorta after incubation with HDX and the vasorelaxant response to Ach after incubation with HDX were quantified. Nitric oxide (NO) production in the aorta of all rats was determined. We also measured the vasorelaxant responses of WKY aorta to different concentrations of SO(2) after incubation with the NO inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME). The blood pressure decreased significantly in SHRs treated with SO(2) derivatives (P < 0.05). Reduction of endogenous SO(2) in WKY vessels resulted in a decrease in the vasorelaxation induced by Ach. Vasorelaxation in response to both Ach and SNP increased in SHRs treated with SO(2) derivatives compared with SHR controls, but decreased in WKY given HDX compared with WKY controls (P < 0.05). The NO level in arterial tissues increased in SHRs treated with SO(2) derivatives (P < 0.05). However, the vasorelaxant response to SO(2) derivatives in the presence of L-NAME decreased markedly compared with WKY controls. The results suggest that SO(2) reduced blood pressure and increased vasorelaxation in SHR arteries via enhancing the vasorelaxant response to NO in isolated aortic rings and increasing the NO level of aortic tissues. PMID:22802518

Lu, Wei; Sun, Yan; Tang, Chaoshu; Ochs, Todd; Qi, Jianguang; Du, Junbao; Jin, Hongfang

2012-07-16

425

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

Code of Federal Regulations, 2010 CFR

...Dioxide in the Atmosphere (Ultraviolet Fluorescence Method) A Appendix A-1 to...Dioxide in the Atmosphere (Ultraviolet Fluorescence Method) 1.0Applicability 1.1This ultraviolet fluorescence (UVF) method provides a...

2010-07-01

426

Sulfuric acid on Europa and the radiolytic sulfur cycle.  

PubMed

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. PMID:10506568

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

1999-10-01

427

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

428

Effects of sulfur dioxide on expansion of lesions caused by Corynebacterium nebraskense in maize and by Xanthomonas phaseoli var. sojensis in soybean  

SciTech Connect

In order to assess the effects of air pollution on plant disease development, the authors investigated the effects of SO/sub 2/ on lesion development by two bacterial pathogens. Maize or soybean plants were exposed to sulfur dioxide (SO/sub 2/) at 524 ..mu..g m/sup -3/ or 262 ..mu..g m/sup -3/ before, after or before and after inoculation with Corynebacterium nebraskense or Xanthomonas phaseoli var. sojensis, respectively. Lesion development was inhibited in both cases, regardless of when the exposures occurred. The time of exposure, however, altered the subsequent effect on lesion size. Dry weight and sulfur content of host tissue were not altered by the joint effects of the pollutant and the pathogens.

Laurence, J.A.; Aluisio, A.L.

1981-01-01

429

Impact of free calcium oxide content of fly ash on dust and sulfur dioxide emissions in a lignite-fired power plant  

SciTech Connect

Emitted pollutants from the Agios Dimitrios lignite-fired power plant in northern Greece show a very strong linear correlation with the free calcium oxide content of the lignite ash. Dust (fly ash) emissions are positively correlated to free calcium oxide content, whereas sulfur dioxide (SO{sub 2}) emissions are negatively correlated. As a result, at present, the Agios Dimitrios Power Plant operates very strictly within the legislative limits on atmospheric particulate emission. In the study reported, the factors to be considered in assessing the impact of lignite combustion on the environment are presented and evaluated statistically. The ash appears to have a remarkable SO{sub 2} natural dry scrubbing capability when the free calcium oxide content ranges between 4 and 7%. Precipitator operating problems attributable to high ash resistivity can be overcome by injecting sulfur trioxide to reduce the ash resistivity, with, of course, a probable increase in operating costs. 27 refs., 7 figs., 1 tab.

Dimitrios Sotiropoulos; Andreas Georgakopoulos; Nestoras Kolovos [Agios Dimitrios Power Plant, Ptolemais (Greece). Public Power Corporation of Greece

2005-07-01

430

Molecular modeling studies, synthesis, configurational stability and biological activity of 8-chloro-2,3,5,6-tetrahydro-3,6-dimethyl-pyrrolo[1,2,3- de]-1,2,4-benzothiadiazine 1,1-dioxide  

Microsoft Academic Search

The potential therapeutic benefit of compounds able to activate AMPA receptors (AMPArs) has led to a search for new AMPAr positive modulators. Among them, 8-chloro-2,3,5,6-tetrahydro-3,6-dimethyl-pyrrolo[1,2,3-de]-1,2,4-benzothiadiazine 1,1-dioxide (1) has attracted particular attention, because it is one of the most active benzothiadiazinederived positive modulators of the AMPA receptor. It possesses two stereogenic centers, C3 and C6, thus it can exist as four

Umberto M. Battisti; Marina M. Carrozzo; Giuseppe Cannazza; Giulia Puia; Luigino Troisi; Daniela Braghiroli; Carlo Parenti; Krzysztof Jozwiak

2011-01-01

431

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); Ferrara, R. [Istituto di Biofisica, Pisa (Italy); Cioni, R.; Raco, B.; Taddeucci, G. [Istituto di Geocronologia e Geochimica Isotopica, Pisa (Italy)

1994-09-20

432

Discharge characteristics of lithium/sulfur dioxide (Li/SO{sub 2}) ``A`` cells---Honeywell Inc., No. G-3029A3  

SciTech Connect

This report presents data which was generated during a series of constant load, discharge tests performed on Lithium/Sulfur Dioxide (Li/SO{sub 2}) ``A`` cells manufactured by Honeywell, Inc., Horsham, Pennsylvania. The discharge tests were run using seven different load conditions and eight temperature regimes. Graphs depicting cell discharge curves (cell voltage versus discharge time) are presented in this report. Test results indicate that the cells performed better at 40 {degree}C and at loads lighter than 100 milliamperes. 2 refs., 12 figs., 1 tab.

Pitre, L.J.

1991-04-01

433

A compilation of sulfur dioxide and carbon dioxide emission-rate data from Cook Inlet volcanoes (Redoubt, Spurr, Iliamna, and Augustine), Alaska during the period from 1990 to 1994  

USGS Publications Warehouse

Airborne sulfur dioxide (SO2) gas sampling of the Cook Inlet volcanoes (Mt. Spurr, Redoubt, Iliamna, and Augustine) began in 1986 when several measurements were carried out at Augustine volcano during the eruption of 1986 (Rose and others, 1988). More systematic monitoring for SO2 began in March 1990 and for carbon dioxide (CO2) began in June, 1990 at Redoubt Volcano (Brantley, 1990 and Casadevall and others, 1994) and continues to the present. This report contains all of the available daily SO2 and CO2 emission rates determined by the U.S. Geological Survey (USGS) from March 1990 through July 1994. Intermittent measurements (four to six month intervals) at Augustine and Iliamna began in 1990 and continues to the present. Intermittent measurements began at Mt. Spurr volcano in 1991, and were continued at more regular intervals from June, 1992 through the 1992 eruption at the Crater Peak vent to the present.

Doukas, Michael P.

1995-01-01

434

Effects on plants of sulfur pollutants from coal combustion  

Microsoft Academic Search

Sulfur dioxide, the most widely known form of sulfur pollution, is highly toxic to plant life, even at levels lower than the current Federal Ambient Air Quality Standard. Sulfur dioxide can also form sulfates, sulfites, and liquids such as sulfurous acid and sulfuric acid, all of which can be toxic to plant and animal life. Most sulfur compounds also acidify

1978-01-01

435

Advanced sulfur control concepts  

Microsoft Academic Search

Regenerable metal oxide sorbents, such as zinc titanate, are being developed to efficiently remove hydrogen sulfide (HS) from coal gas in advanced power systems. Dilute air regeneration of the sorbents produces a tailgas containing a few percent sulfur dioxide (SO). Catalytic reduction of the SO to elemental sulfur with a coal gas slipstream using the Direct Sulfur Recovery Process (DSRP)

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

1995-01-01

436

Using a mobile laboratory to characterize the distribution and transport of sulfur dioxide in and around Beijing  

NASA Astrophysics Data System (ADS)

Megacities are places with intensive human activity and energy consumption. To reduce air pollution, many megacities have relocated energy supplies and polluted industries to their outer regions. However, regional transport then becomes an important source of air pollution in megacities. To improve air quality before and during the 2008 Beijing Olympics, a wide range of control strategies were implemented, including the relocation of polluting industries. High sulfur dioxide (SO2) concentrations were occasionally observed during this period. Potential sources from southern regions of Beijing were indicated by backward trajectories and urban/rural stationary measurements, but direct evidence was lacking. Here we used a mobile laboratory to characterize the spatial distribution and regional transport of SO2 to Beijing during the Campaign for Air Quality Research in Beijing and the Surrounding Region (CAREBEIJING)-2008. Among the five days chosen for the case studies during the Olympic air pollution control period, four had high SO2 concentrations (6, 20 August and 3, 4 September 2008) while one had low SO2 concentration (11 September 2008). The average values of SO2 during the low SO2 concentration day were 3.9 ppb, much lower than during the high concentration days (7.8 ppb). This result implied an impact by regional transport from outside Beijing. During these days, we captured transport events of SO2 from areas south of Beijing, with a clear decrease in SO2 concentrations southeast of the 6th to 4th Ring Roads around Beijing and along the 140 km highway from Tianjin to Beijing. The influx of SO2 through the 4th to 6th Ring Roads ranged from 2.07 to 4.64 kg s-1 on 4 September and 0.21 to 1.56 kg s-1 on 20 August 2008. Locally emitted SO2 from a source located along Jingshi Highway outside the southwest section of the 5th Ring Road of Beijing was identified using wind field data generated by the Weather Research and Forecasting model and the measured particle size distribution, with an estimated flux of 0.11 kg s-1 to Beijing.

Wang, M.; Zhu, T.; Zhang, J. P.; Zhang, Q. H.; Lin, W. W.; Li, Y.; Wang, Z. F.

2011-06-01

437

Using a mobile laboratory to characterize the distribution and transport of sulfur dioxide in and around Beijing  

NASA Astrophysics Data System (ADS)

Megacities are places with intensive human activity and energy consumption. To reduce air pollution, many megacities have relocated energy supplies and polluted industries to their outer regions. However, regional transport then becomes an important source of air pollution in megacities. To improve air quality before and during the 2008 Beijing Olympics, a wide range of control strategies were implemented, including the relocation of polluting industries. High sulfur dioxide (SO2) concentrations were occasionally observed during this period. Potential sources from southern regions of Beijing were indicated by backward trajectories model and urban/rural stationary measurements, but direct evidence was lacking. Here we used a mobile laboratory to characterize the spatial distribution and regional transport of SO2 to Beijing during the Campaign for Air Quality Research in Beijing and the Surrounding Region (CAREBEIJING)-2008. Among the five days chosen for the case studies during the Olympic air pollution control period, four had high SO2 concentrations (6, 20 August and 3, 4 September 2008) while one had low SO2 concentration (11 September 2008). The average values of SO2 during the low SO2 concentration day were 3.9 ppb, much lower than during the high concentration days (7.8 ppb). This result implied an impact by regional transport from outside Beijing. During these days, we captured transport events of SO2 from areas south of Beijing, with a clear decrease in SO2 concentrations southeast of the 6th to 4th Ring Roads around Beijing and along the 140 km highway from Tianjin to Beijing. The influx of SO2 through the 4th to 6th Ring Roads ranged from 2.1 to 4.6 kg s-1 on 4 September and 0.2 to 1.6 kg s-1 on 20 August 2008. The differences of influx in days were due to the variations of emission changes, transport directions and dilutions. Locally emitted SO2 from a source located along Jingshi Highway outside the southwest section of the 5th Ring Road of Beijing was identified using wind field data generated by the Weather Research and Forecasting model and the measured particle size distribution, with an estimated flux of 0.1 kg s-1 to Beijing. Estimated uncertainties for SO2 influx were approximately 31%.

Wang, M.; Zhu, T.; Zhang, J. P.; Zhang, Q. H.; Lin, W. W.; Li, Y.; Wang, Z. F.

2011-11-01

438

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

439

The impact of aqueous sulfur dioxide upon the reactions and availability of hydrocyanic acid and formaldehyde on prebiotic Earth  

NASA Astrophysics Data System (ADS)

Formaldehyde (CH2O) and hydrogen cyanide (HCN) are important precursors of biomolecules critical to life. Individually, CH2O solutions yield sugars while HCN solutions yield nucleobases. The formation of sugars and nucleobases is inhibited in solutions containing both CH 2O and HCN, however due to the reaction of CH2O with HCN to form glycolonitrile. Since the hydrosphere of primitive Earth is thought to have contained both CH2O and HCN, it is important to limit glycolonitrile formation so these biomolecules can arise. The problem presented by glycolonitrile's formation in solutions containing both CH2O and HCN is called the Miller paradox. This study sought to address the Miller paradox by evaluating the role that sulfur dioxide (SO 2) plays in the polymerization reactions of these precursor molecules. In the aqueous phase, SO2 hydrates and dissociates to bisulfite (HSO3-) and sulfite (SO32-), both of which react with CH2O to form hydroxymethanesulfonic acid (HMSA). Because of this, SO2 should compete with HCN for CH 2O. It was hypothesized that equimolar solutions of CH2O, NaCN, and Na2SO3 would form HMSA, leaving an equivalent amount of cyanide free to polymerize to its tetramer, diaminomaleonitrile (DAMN). HMSA was measured using capillary electrophoresis (CE) while DAMN was measured using a reverse phase high performance liquid chromatography (RP-HPLC) method developed for this study. HMSA and DAMN concentrations were measured in solutions of variable CH2O, NaCN, and Na2SO 3 composition, pH, and oxygen availability. Room-temperature bicarbonate-buffered NaCN solutions at pH values near the pKa of HCN (pH9) polymerized rapidly, forming DAMN at concentrations near 30 muM over 8 days. The addition of equimolar CH 2O to similar NaCN solutions eliminated DAMN formation (<0.02 muM), consistent with the Miller paradox. The addition of SO2 (as Na 2SO3) to solutions containing CH2O and NaCN, however, allowed the polymerization of HCN to DAMN (1-2 muM) through the reaction of CH2O with HSO3- to form HMSA (20 mM). DAMN and HMSA were also formed from the reaction of glycolonitrile with HSO3-. Measured HMSA concentrations were consistent with concentrations predicted from equilibrium model calculations. Results from this study suggest that SO2 may have played a critical role in the chemical origins of life.

Whiteford, Jamie Keith

440

Determination of the effects of sulfur dioxide on recovery systems for CO/sub 2/. Final report, 1977-1980  

SciTech Connect

The present study was initiated to investigate the problems associated with recovery of CO/sub 2/ from flue gases for enhanced oil recovery. In particular, the scope of this work may be stated: determine the type of impurities formed in ammonia, monoethanolamine (MEA), and potassium carbonate systems when extracting CO/sub 2/ from oxidizing flue gases containing nitrogen oxides and sulfur oxides; determine the levels of impurity build-up in the solvents; estimate the impurity level in the recovered CO/sub 2/; evaluate the effect on corrosion in metals by these solvents in a flue gas environment; determine the carbon-dioxide absorption coefficients in solvents contaminated due to the pollutants present in the flue gas; evaluate the effect of particulate matter on absorption coefficients in the solvents; and recommend potential absorption systems for CO/sub 2/ from flue gas and estimate the cost of recovery. The results of this study indicate that in ammonia, ammonia sulfate is quickly formed to render that portion of the absorbent inactive. In MEA, amine sulfite and amine sulfate are the dominant impurities formed. In amine-activated potassium carbonate solutions, only sulfite and sulfate ions were found. No nitrogen-oxide species were found in any solution. The impurity levels obtained in the present experiments indicated no limit on contaminant build-up. The impurity level in the recovered CO/sub 2/ was estimated to be less than or equal to 100 ppM non-condensible gases, 20 to 200 ppM SO/sub 2/, and < 20 ppM NO/sub x. Corrosion in the absorption systems will be similar to that observed in CO/sub 2/ absorption systems from reducing gas streams. The absorption rate of CO/sub 2/ in solutions decreases with increasing loading of CO/sub 2/ in almost a linear fashion. Several alternative absorption systems were evaluated in a preliminary cost evaluation, and a K/sub 2/CO/sub 3/ (EAE activated) solution was recommended.

Sears, J.T.

1981-01-01

441

A Comparison of Sulfur Dioxide Column Content Between Aircraft and Satellite Over the U.S. Mid-Atlantic  

NASA Astrophysics Data System (ADS)

Sulfur Dioxide (SO2) is a major contributor to air pollution in the mid-Atlantic region of the United States. Sources of SO2 include coal fired power plants as well as diesel engines. Fine particulate sulfate (with diameter less than 2.5 mm) formed from SO2 can cause health problems as well as decreased visibility. Reliable measurements of SO2 within the lower troposphere are needed to determine sources, test emission inventories and to evaluate federal air quality standards. Monthly averages of SO2 lower-tropospheric column content for various points in the mid-Atlantic region of the United States have been calculated from episodic aircraft measurements during the summer months of 2000 and 2001 (http://www.meto.umd.edu/~umdair/rammpp01.html). A Thermo Environmental Instruments 4 3C SO2 analyzer was used to obtain data during aircraft spiral profiles, usually made from the near-surface to an altitude in the range of 2.3 to 3.1 km. From June to August 2000, 44 columns of SO2 were calculated from aircraft profiles over 11 different locations between North Carolina and Pennsylvania. Individual column concentrations of SO2 ranged from 0.10 to 2.31 Dobson Units (DU). Monthly averaged column concentrations were made for each location and the average concentrations for 2000 ranged from 0.02 to 1.18 DU. In 2001, 149 columns of SO2 were obtained from 36 different locations for the months of May through August. The individual column concentrations ranged from 0.01 to 3.40 DU and the monthly averaged columns ranged from 0.05 to 3.40 DU. UV-visible spectra collected by the Global Ozone Monitoring Experiment (GOME) have been analyzed for SO2 by the research group at the University of Bremen in Germany (http://www.iup.physik.uni-bremen.de/gome/). The period of data collection by the University of Maryland team coincide with data collection by the University of Bremen. The monthly averages of SO2 determined from aircraft measurements are compared with measurements from the satellite in order to characterize the transport and dynamics of SO2 over the mid-Atlantic region.

Hains, J. C.; Dickerson, R. R.; Doddridge, B. G.; Burrows, J. P.; Richter, A.

2002-12-01

442

Methods of measuring sulfur dioxide, dustfall and suspended matter in city air, and their use in the study of air pollution in Italy.  

PubMed

This paper presents a comparative survey of the methods and apparatus used in Italy, particularly in Genoa, for measuring the three main components of city air pollution-sulfur dioxide, dustfall and suspended matter.The most frequently employed devices for sampling sulfur dioxide are the lead-peroxide and volumetric apparatuses, as developed by the British Department of Scientific and Industrial Research. For the collection of dustfall, the British standard deposit gauge is widely used; in Genoa, a simple, low-cost type of dustfall collector has been tried in combination with that gauge, and good results have been obtained. The measurement of suspended matter is effected by the thermal precipitator, electrostatic precipitator and konimeters of different types, in addition to the classic method of filtration through various media. In Genoa, suspended matter is monitored by automatic filter-paper samplers and directional samplers. The use of membrane filters for counting dust particles has proved particularly satisfactory.All these techniques are described in detail, and their results are subjected to statistical analysis. PMID:14485898

PETRILLI, F L

1962-01-01

443

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

444

Sulfur-Oxygen Processes on Io.  

National Technical Information Service (NTIS)

Laboratory studies of irradiated sulfur dioxide frost have found that sulfur trioxide should be formed as a consequence of the irradiation process. The spectral reflectance of solid sulfur trioxide was measured in the laboratory and it was found that the ...

R. M. Nelson W. D. Smythe

1987-01-01

445

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 BaSO-VO-SiO for the preparation of SO 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 ¹⁸O\\/¹⁶O ratio of SO must be kept constant in order to apply

F. Yanaglsawa; Hitoshi. Sakai

1983-01-01

446

Sulfur gas emissions from stored flue gas desulfurization solids. Final report  

SciTech Connect

The emissions of volatile, sulfur-containing compounds from the surfaces of 13 flue gas desulfurization (FGD) solids field storage sites have been characterized. The sulfur gas emissions from these storage surfaces were determined by measuring the sulfur gas enhancement of sulfur-free sweep air passing through a dynamic emission flux chamber placed over selected sampling areas. Samples of the enclosure sweep air were cryogenically concentrated in surface-deactivated Pyrex U traps. Analyses were conducted by wall-coated, open-tubular, capillary column, cryogenic, temperature-programmed gas chromatography using a sulfur-selective flame photometric detector. Several major variables associated with FGD sludge production processes were examined in relation to the measured range and variations in sulfur fluxes including: the sulfur dioxide scrubbing reagent used, sludge sulfite oxidation, unfixed or stabilized (fixed) FGD solids, and ponding or landfill storage. The composition and concentration of the measured sulfur gas emissions were found to vary with the type of solids, the effectiveness of rainwater drainage from the landfill surface, the method of impoundment, and the sulfate/sulfite ratio of the solids. The FGD solids emissions may contain hydrogen sulfide, carbonyl sulfide, dimethyl sulfide, carbon disulfide, and dimethyl disulfide in varying concentrations and ratios. In addition, up to four unidentified organo-sulfur compounds were found in the emissions from four different FGD solids. The measured, total sulfur emissions ranged from less than 0.01 to nearly 0.3 kg of sulfur per day for an equivalent 40.5 hectare (100 acre) FGD solids impoundment surface.

Adams, D.F.; Farwell, S.O.

1981-10-01

447

Dimethyl Sulfoxide  

PubMed Central

Dimethyl sulfoxide is a colorless liquid derived as a by-product from wood pulp in the production of paper. This colorless liquid found immediate application as a polar, aprotic solvent miscible with water and able to dissolve an enormous catalog of polar and nonpolar small molecules. It is presently scarcely used in dermatology, but given its useful properties as a penetration-enhancing solvent excipient and active anti-inflammatory pharmaceutical agent, dimethyl sulfoxide has the potential to be used in a much broader capacity. The authors review the history, chemistry, and clinical utility of dimethyl sulfoxide as it pertains to dermatology.

Capriotti, Joseph A.

2012-01-01

448

Interaction of mineral dust with gas phase nitric acid and sulfur dioxide during the MINATROC II field campaign: First estimate of the uptake coefficient ?HNO3 from atmospheric data  

Microsoft Academic Search

Mineral dust, one of the most abundant aerosols by mass in the atmosphere, may have a lasting but to date almost unexplored effect on the trace gases nitric acid (HNO3) and sulfur dioxide (SO2). These gases have an important influence on, for example, the tropospheric ozone cycle, aerosol formation or acid rain. Within the second part of the MINATROC project

B. Umann; F. Arnold; C. Schaal; M. Hanke; J. Uecker; H. Aufmhoff; Y. Balkanski; R. Van Dingenen

2005-01-01

449

Chemical Recycling of Carbon Dioxide to Methanol and Dimethyl Ether: From Greenhouse Gas to Renewable, Environmentally Carbon Neutral Fuels and Synthetic Hydrocarbons  

Microsoft Academic Search

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

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

2009-01-01

450

Correct Assembly of Iron-Sulfur Cluster FS0 into Escherichia coli Dimethyl Sulfoxide Reductase (DmsABC) Is a Prerequisite for Molybdenum Cofactor Insertion*  

PubMed Central

The FS0 [4Fe-4S] cluster of the catalytic subunit (DmsA) of Escherichia coli dimethyl sulfoxide reductase (DmsABC) plays a key role in the electron transfer relay. We have now established an additional role for the cluster in directing molybdenum cofactor assembly during enzyme maturation. EPR spectroscopy indicates that FS0 has a high spin ground state (S = 32) in its reduced form, resulting in an EPR spectrum with a peak at g ? 5.0. The cluster is predicted to be in close proximity to the molybdo-bis(pyranopterin guanine dinucleotide) (Mo-bisPGD) cofactor, which provides the site of dimethyl sulfoxide reduction. Comparison with nitrate reductase A (NarGHI) indicates that a sequence of residues (18CTVNC22) plays a role in both FS0 and Mo-bisPGD coordination. A DmsA?N21 mutant prevented Mo-bisPGD binding and resulted in a degenerate [3Fe-4S] cluster form of FS0 being assembled. DmsA belongs to the Type II subclass of Mo-bisPGD-containing catalytic subunits that is distinguished from the Type I subclass by having three rather than two residues between the first two Cys residues coordinating FS0 and a conserved Arg residue rather than a Lys residue following the fourth cluster coordinating Cys. We introduced a Type I Cys group into DmsA in two stages. We changed its sequence from 18CATVNCBGSRCCP27 to 18CATYCBGVGCCG26 (similar to that of formate dehydrogenase (FdnG)) and demonstrated that this eliminated both Mo-bisPGD binding and EPR-detectable FS0. We then combined this change with a DmsAR61K mutation and demonstrated that this additional change partially rescued Mo-bisPGD insertion.

Tang, Huipo; Rothery, Richard A.; Voss, James E.; Weiner, Joel H.

2011-01-01

451

40 CFR Appendix A to Part 50 - Reference Method for the Determination of Sulfur Dioxide in the Atmosphere (Pararosaniline Method)  

Code of Federal Regulations, 2010 CFR

...rate of carrier gas across permeation device, std L/min. 50-712...Caution must be exercised as hydrogen gas is evolved by this treatment...Saltzman. Evaluation of Teflon Permeation Tubes for Use with Sulfur...Concentrations of Gases and Vapors With Permeation Devices Calibrated...

2009-07-01

452

40 CFR Appendix A to Part 50 - Reference Method for the Determination of Sulfur Dioxide in the Atmosphere (Pararosaniline Method)  

Code of Federal Regulations, 2010 CFR

...rate of carrier gas across permeation device, std L/min. 50-712...Caution must be exercised as hydrogen gas is evolved by this treatment...Saltzman. Evaluation of Teflon Permeation Tubes for Use with Sulfur...Concentrations of Gases and Vapors With Permeation Devices Calibrated...

2010-07-01

453

[In vitro studies of modification of mucociliary clearance by guinea pig tracheas by exposure to air pollutants of sulfur or nitrogen dioxide].  

PubMed

We studied the effect of sulfur dioxide (SO2) and nitrogen dioxide (NO2) on mucociliary activity (MCA) and ciliary beat frequency (CBF) in 63 guinea pig tracheas. The tracheas were placed in a gas cylinder and exposed for 30 minutes to SO2 concentrations ranging from 2.5 to 12.5 ppm or to NO2 concentrations ranging from 3.0 to 15.0 ppm. Control experiments were performed with exposure of the tracheas to synthetic air. MCA was measured by recording the light reflected from ciliated mucous membranes using an infrared barcode reader and CBF using video-interference microscopy. The exposure to 2.5 ppm SO2 caused a reduction in mean MCA of 63% and no significant changes in CBF. Higher SO2 concentrations caused a further impairment of MCA as well as a dose-dependent decrease in CBF. 10.0 or 12.5 ppm SO2 induced a decrease from baseline values to approximately 20% in MCA and to roughly 30% in mean CBF. The exposure to NO2 at concentrations ranging from 3.0 to 15.0 ppm did not induce any changes in MCA or CBF of the guinea pig tracheas. Our results show that exposure to SO2 for 30 minutes is able to depress the mucociliary clearance of guinea pig tracheas, whereas the exposure to equivalent NO2 concentrations for the same time do not alter the mucociliary transport. PMID:8072990

Knorst, M M; Kienast, K; Riechelmann, H; Mller-Quernheim, J; Ferlinz, R

1994-06-01

454

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

455

Intercomparison of measurements of sulfur dioxide in ambient air by carbonate-impregnated filters and Teco pulsed-fluorescence analyzers  

Microsoft Academic Search

In two previous University of Washington field programs, airborne measurements of SO2 using carbonate-impregnated filters and a Teco pulsed-fluorescence analyzer showed excellent agreement over a range of ambient concentrations from 2 to 127 ppbv. As part of the Gas-Phase Sulfur Intercomparison Experiment (GASIE), ambient air, diluted fivefold to tenfold with zero air, was sampled in the concentration range of 0.02

Ronald J. Ferek; Paul A. Covert; Winston Luke

1997-01-01

456

The Radiolysis of Sulfur Dioxide and Hydrogen Sulfide in Water Ice: Implications for the Icy Jovian Satellites  

NASA Astrophysics Data System (ADS)

Spectra of Europa, Ganymede, and Callisto reveal surfaces dominated by frozen water (Calvin et al., 1995), hydrated materials (McCord et al., 1998b; Carlson et al., 1999), and minor amounts of SO2 (Lane et al., 1981; Noll et al., 1995), CO2 (Smythe et al., 1998), and H2O2 (Carlson et al., 1999). These icy moons undergo significant bombardment by jovian magnetospheric radiation (protons, electrons, and sulfur and oxygen ions) which alters their surface compositions. In order to understand these radiation-induced changes, we have measured the mid-infrared (IR) spectra of proton-irradiated H2O-ice mixtures containing SO2 or H2S. Samples with H2O/SO2 or H2O/H2S ratios of 3 and 30 have been irradiated at 86 K, 110 K, and 132 K, and the radiation half-lives of SO2 and H2S have been determined. New radiation products include H2S2, and ions (SO42- and HSO4-). During warming, we have identified the IR spectrum of both the tetrahydrate and monohydrate of sulfuric acid. In addition we have documented the dehydration of the monohydrate to form sulfuric acid near 250 K. A summary of these findings will be presented along with implications of similar processes affecting the outer icy shells of Europa, Ganymede, and Callisto. 691.gsfc.nasa.gov/cosmic.ice.lab

Moore, M. H.; Hudson, R. L.; Carlson, R. L.

2006-05-01

457

ADVANCED SULFUR CONTROL CONCEPTS  

Microsoft Academic Search

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 (sulfur dioxide) tail gas. Under previous contracts the

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

2003-01-01

458

The reductive tricarboxylic acid cycle of carbon dioxide assimilation: initial studies and purification of ATP-citrate lyase from the green sulfur bacterium Chlorobium tepidum.  

PubMed Central

Carbon dioxide is fixed largely by the reductive tricarboxylic acid (RTCA) cycle in green sulfur bacteria. One of the key enzymes, ATP-citrate lyase, was purified to apparent homogeneity from the moderately thermophilic green sulfur bacterium Chlorobium tepidum. The molecular weight of the native enzyme was about 550,000, and the preponderance of evidence indicated that the protein is composed of identical subunits (Mr of approximately 135,000) which degraded to two major proteins with Mrs of approximately 65,000 and approximately 42,000. Western immunoblots and in vitro phosphorylation experiments indicated that these two species could have been the result of proteolysis by an endogenous protease, similar to what has been observed with mammalian, yeast, and mold ATP-citrate lyase. In addition to apparent structural similarities, the catalytic properties of C. tepidum ATP-citrate lyase showed marked similarities to the eukaryotic enzyme, with significant differences from other prokaryotic ATP-citrate lyases, including the enzyme from the closely related organism Chlorobium limicola. Phosphorylation of C. tepidum ATP-citrate lyase occurred, presumably on a histidine residue at the active site, similar to the case for the mammalian enzyme. In contrast to the situation observed for other prokaryotic ATP-citrate lyase enzymes, the C. tepidum enzyme was not able to replace ATP and GTP for activity or use Cu2+ to replace Mg2+ for enzyme activity. Given the apparent structural and catalytic similarities of the enzyme from C. tepidum and its eukaryotic counterpart, the C. tepidum system should serve as an excellent model for studies of the enzymology and regulation of this protein.

Wahlund, T M; Tabita, F R

1997-01-01