Low Concentrations Of Sulphur Dioxide Research Articles

Atomic sulphur lines from above the first ionisation limit

A radiofrequency inductively coupled plasma discharge in argon has been employed as an excitation source for the study of the spectrum of atomic sulphur produced on introduction of low concentrations of sulphur dioxide into the discharge. Several previously unassigned lines in the observed spectrum have been attributed to transitions occurring in the SI atom from stable states above the 4S32/0 first ionisation limit.

Determination of sulphur trioxide and sulphuric acid in flue gases in presence of oxygen, carbon dioxide, sulphur dioxide and nitric oxides

q-he difficulties in the determination of small amounts of sulphur trioxide in gases in presence of sulphur dioxide, oxygen and nitric oxides are generally acknowledged. In order to overcome these interferences several precautions are necessary. To catch all sulphur trioxide and sulphuric acid the sampling with vacuum flask is most reliable. The determination of sulphur trioxide and sulphuric acid as difference (total sulphur-sulphur as dioxide) suffers from the inaccuracy due to the fact that low concentrations of sulphur dioxide are easily oxidized and further small amounts of nitric oxides interfere in the iodometric titration of sulphur dioxide (disturb the endpoint). The interference of nitric oxides can be avoided by means of sulphamic acid and thus a distinct endpoint is obtained. In order to avoid the interference due to oxidation the gas sample is sucked simultaneously through two parallel gas washing flasks. In one line the gas is oxidized by means of hydrogen peroxide 1 and the total sulphur is determined gravimetrically. In the other line SO2 is oxidized immediately with a measured excess of potassium dichromate solution in presence of sulphuric/sulphamic acid and determined iodometrieally. SO3 --}1-t2SO4 is obtained as difference. The apparatus consists of two 5-1 filtering flasks with ground stoppers with stopcocks. Before each flask are two gas washing bottles with sintered discs and before these gas washing bottles is an empty gas washing bottle with or without sintered disc. In one line each gas washing flask contains 50 ml of 5% hydrogen peroxide solution and the 5-1 filtering flask 100 ml of distilled water. In the other line each gas washing flask contains 50 ml of 0.02 N potassium dichromate solution containing 10 ml of sulphuric acid (D 1.4) and 50 g of sulphamic acid in 1 1. The total apparatus is evacuated, the stopcocks behind the filtering flask are closed and by regulating the stopcock behind the empty gas washing flask the gas is sucked in with a speed of 0.5-1 l/rain (about 5-10 rain). After this the 5-1 filtering flask in the hydrogen peroxide line is shaken and the contents of the flasks are combined, hydrochloric acid is added and boiled. The total sulphur is determined gravimetrically by precipitating with BaC12 solution. The potassium dichromate solutions are combined and transferred into a 300 ml Erlenmeyer flask. The excess of chromate is titrated with 0.05 N sodium thiosulphate solution using potassium iodide and starch. Sulphur dioxide is calculated from the amount of chromate consumed. Finally sulphur trioxide in the gas is obtained as difference (total sulphur-sulphur as dioxide). The empty gas washing flask is catching any water and sulphuric acid droplets in the tubing and these are neglected. If necessary this sulphur be determined separately, perhaps also by means of a Millipore-filter. Because the SO2 is oxidized immediately the interferences due to uncontrolled oxidation in later steps are excluded. Sulphamic acid reacts with nitric oxides according to the reaction HSO3NH2 + HNO2 = H2SO4 + H20 + N2.

Factors affecting the collection of sulphur dioxide from low-velocity jets

Some factors affecting the collection efficiency of the low-velocity jet impinger and conductivity cell have been investigated for low concentrations of sulphur dioxide in air. These factors were : (1) the size of the conductivity cell ; (2) the bore of the jet ; (3) the air flow rate ; (4) the distance between the jet and the reagent surface; (5) the ambient temperature. By choosing optimum values for factors 1–4, a collection efficiency of approximately 90% may be obtained at room temperature.

Effect of low concentrations of sulfur dioxide on respiratory function in man.

Respiratory function was evaluated in human subjects breathing SO2 (0.5–5.0 ppm) by mouth for 1–5 min. A variable response of maximal expiratory flow rates was obtained at rest. Light exercise potentiated the effect of 3.0 ppm whereas premedication with propranolol or indomethacin did not. Symptoms were consistently observed on exposure to 3.0 ppm or greater. These data suggest that re-evaluation of the present threshold limit value is indicated.

Effects of Long-Term Exposure to Low Concentration of Sulfur Dioxide on the Mouse Respiratory Organs

Effects of Long-Term Exposure to Low Concentration of Sulfur Dioxide on the Mouse Respiratory Organs

The Absorption of Low Concentrations of Sulphur Dioxide into Aqueous Solutions

The Absorption of Low Concentrations of Sulphur Dioxide into Aqueous Solutions

The Absorption of Low Concentrations of Sulphur Dioxide into Aqueous Solutions

The rate of deposition of gas-phase SO 2 to a variety of aqueous solutions has been measured. The deposition rate is unaffected by relative humidity. Some salts may cause a 3-fold decrease in deposition rate as the ionic strength changes from 0.1 M to 0.8 M. Solution pH has the greatest influence causing a change from gas-phase diffusion control to solution phase diffusion control of deposition between pH 4 and pH 2. Indirect evidence has been obtained that suggests that the catalysis of SO 2 oxidation in solution by Mn(II) ions is slow with respect to SO 2 diffusion into solution. The practical implications of these results are discussed. DOI: 10.1111/j.2153-3490.1974.tb01977.x

Electronic circuits for recording of maximum expiratory flow-volume (MEFV) curves.

ArticleElectronic circuits for recording of maximum expiratory flow-volume (MEFV) curves.J Virgulto, and A BouhuysJ Virgulto, and A BouhuysPublished Online:01 Jul 1973https://doi.org/10.1152/jappl.1973.35.1.145MoreSectionsPDF (588 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByAirway Responses to the Inhalation of Cotton Dust and Cotton Bract Extracts10 February 2006 | Respiration, Vol. 73, No. 1Bronchial Responsiveness after Inhalation of Cotton Bract ExtractAmerican Review of Respiratory Disease, Vol. 138, No. 6Airway Responses to 2.0 ppm Nitrogen Dioxide in Normal SubjectsArchives of Environmental Health: An International Journal, Vol. 43, No. 3A study of respiratory effects from exposure to 2.0 ppm formaldehyde in occupationally exposed workersEnvironmental Research, Vol. 44, No. 2Airway responses to nitrogen dioxide in asthmatic subjectsJournal of Toxicology and Environmental Health, Vol. 22, No. 4Effect of Vitamin C on NO 2 -induced Airway Hyperresponsiveness in Normal Subjects: A Randomized Double-Blind ExperimentAmerican Review of Respiratory Disease, Vol. 136, No. 6Relationship of the Ventilatory Response to Cotton Bract Extract and the Cells and Proteins of the LungChest, Vol. 91, No. 1A Study of Respiratory Effects from Exposure to 2 ppm Formaldehyde in Healthy SubjectsArchives of Environmental Health: An International Journal, Vol. 41, No. 4Airway constrictor response to cotton bract extracts in the absence of endotoxin.Occupational and Environmental Medicine, Vol. 43, No. 4Acute Effects of Passive Smoking on Lung Function and Airway Reactivity in Asthmatic SubjectsChest, Vol. 89, No. 2Controlled human studies on the pulmonary effects of indoor air pollution: Experiences with sulful dioxide and formaldehydeEnvironment International, Vol. 12, No. 1-4Skin testing with an aqueous extract of cotton bractJournal of Allergy and Clinical Immunology, Vol. 76, No. 3Airway Reactivity and Cotton Bract-Induced Bronchial ObstructionChest, Vol. 87, No. 1Bronchoalveolar LavageChest, Vol. 85, No. 6Characterisation of textile dust extracts: II. Bronchoconstriction in man.Occupational and Environmental Medicine, Vol. 41, No. 1Airway Effects of Low Concentrations of Sulfur Dioxide: Dose-Response CharacteristicsArchives of Environmental Health: An International Journal, Vol. 39, No. 1Histamine Blocking Agents in Healthy and Asthmatic SubjectsChest, Vol. 82, No. 2Airway Reactivity and Exercise in Healthy SubjectsChest, Vol. 81, No. 4Helium-oxygen flow-volume curves in detecting acute response to hair sprayInternational Archives of Occupational and Environmental Health, Vol. 49, No. 1Lung function changes by ethanol inhalationClinical <html_ent glyph="@amp;" ascii="&"/> Experimental Allergy, Vol. 11, No. 3A Purified Extract from Cotton Bracts Induces Airway Constriction in HumansChest, Vol. 79, No. 4The Effect of Mediator Modifying Drugs in Cotton Bract-Induced BronchospasmChest, Vol. 79, No. 4Byssinosis: Airway constrictor response to cotton bractsLung, Vol. 158, No. 1Acute and Chronic Effects of Fire Fighting on Pulmonary FunctionChest, Vol. 77, No. 3Flow-volume measurements with a spirometerLung, Vol. 157, No. 1Respiratory deposition of hair spray aerosol and acute lung function changesLung, Vol. 156, No. 1Calibration of flow-volume curves1 December 1978 | Lung, Vol. 155, No. 1Peripheral pooling of bronchographic contrast material: evidence of its relationship to smoking and emphysema.Thorax, Vol. 33, No. 2Electronic device for the recording of isopressure-flow-volume (i.p.f.v.) curvesMedical & Biological Engineering & Computing, Vol. 16, No. 1Effect of low concentrations of sulfur dioxide on respiratory function in manLung, Vol. 154, No. 1W10294A: A new bronchodilatorLung, Vol. 154, No. 1Inhibition of histamin-induced airway constriction negative results with oxtriphylline and ascorbic acidLung, Vol. 154, No. 1Early lung disease in asbestos-product workersLung, Vol. 154, No. 1Flow-volume integrator for respiratory studiesMedical & Biological Engineering, Vol. 14, No. 6Respiratory Effects of Occupational Exposure to an Epoxy Resin SystemArchives of Environmental Health: An International Journal, Vol. 31, No. 5Pulmonary Elastic Recoil and Diffusing Capacity in Subjects with Intermediate Concentrations of Alpha-1 Antitrypsin25 March 2008 | Australian and New Zealand Journal of Medicine, Vol. 6, No. 4Airway Disease Caused by Phenolic (Phenol-Formaldehyde) Resin ExposureArchives of Environmental Health: An International Journal, Vol. 30, No. 12Lung function in textile workers.Occupational and Environmental Medicine, Vol. 32, No. 4Acute Airway Responses to Hair-Spray PreparationsNew England Journal of Medicine, Vol. 290, No. 12A PHYSIOLOGICAL STUDY OF BYSSINOSIS IN COLONIAL AMERICA*30 April 2012 | Transactions of the New York Academy of Sciences, Vol. 35, No. 7 Series II More from this issue > Volume 35Issue 1July 1973Pages 145-7 https://doi.org/10.1152/jappl.1973.35.1.145PubMed4716150History Published online 1 July 1973 Published in print 1 July 1973 Metrics

The role of metallic component in the iron-alumina bifunctional catalyst for reduction of SO 2 with CO

The interaction of low concentrations of sulfur dioxide with carbon monoxide proceeds efficiently on a bifunctional iron-alumina catalyst. The iron component in the pelletized, mixed catalyst was rapidly transformed to pyrrhotite, FeS, with an apparent decrease in activity. The catalyst effectiveness then remained steady for a prolonged period of time. The catalyst decay can be temporarily delayed by carbidizing its iron component. Carbonyl sulfide by-product begins to form when all the iron surface is sulfidized; hence it was absent in the effluent gas during the catalyst break-in period. Red bauxite and Surinam red mud showed promise as commercial catalysts for recovery of sulfur from sulfurous waste gases.

Some aspects of the performance of rare earth modified nickel‐base alloys in hot corrosion conditions

AbstractRare earth additions have shown improvements to corrosion behaviour of nickel and cobalt base superalloys in simulated fuel combustion corrosion situations. “Hot corrosion”tests, at various levels of severity, have been conducted on nickel‐base alloys in the range of 870 to 1200°C with sulfur supplied from molten sodium sulfate or from low concentrations of sulfur dioxide in argon (0.2% SO2). The results show, that rare earth as oxide is essential for corrosion resistance in sulfurous environments.

Ciliary activity and pulmonary retention of inhaled dust in rats exposed to sulfur dioxide.

While the ciliary activity in the airways of rats exposed to sulfur dioxide at low concentration has been studied repeatedly, the effects of chronic exposure to realistic levels of sulfur dioxide and particulates has not been determined. This paper describes the response of white albino rats to the inhalation of low concentrations of sulfur dioxide while exposed to relatively high concentrations of an inert dust. Test results indicate that no change is found in the ciliary activity or the relative number of dust cells in the alveolar structure of rats exposed to 1 ppm of sulfur dioxide and 1 mg/m3 of a graphite dust.

The usefulness of the method of sine wave oscillating pressure for measuring total respiratory flow resistance in human subjects and guinea pigs

The validity and the applicability of a sine wave oscillation method for measuring total respiratory flow resistance (viscous resistance of chest lung system) are discussed with a series of experiments by using bodyplethysmograph in man and guinea pig.The principle of this method, which was introduced by DuBois and developed by Mead, is that the total respiratory flow resistance can be estimated by the bodyplethysmograph through which the sine wave pressure is imposed to the chest lung system to attain a resonant state (to get zero value of the reactance in the simulated electrical R-L-C circuit) by adjusting the frequency of the wave.The results obtained by using the bodyplethysmographs and the pressure imposing device which are designed by the author are as follows.1. The frequency of the sine wave oscillation with which the reactance of the chest lung system becomes zero, was found to be 7∼9c.p.s. in both man and guinea pig. And over 12c.p.s. the impedance of the system showed a steep rise.2. By analysing the flow and its imposed pressure curves, it was found that the total respiratory flow resistance showed continuous change according to a various stage of the flow curve.3. Used an artificial mouth piece resistor with known resistance of three kinds in man, the frequencies 7∼9c.p.s. also showed the most pertinent reproducibility, and the impedance was overestimated by the below or above frequencies of this range.4. In applying to the short term inhalation study of low concentration of sulfur dioxide (1.5∼2.0ppm) in man, this technique revealed rapid response and individual difference of the sensitivity of the total respiratory flow resistance after few seconds of the exposure.5. In long term exposure of guinea pigs to 0.1ppm of toluene diisocyanate vapor without any surgical treatment, the animals showed a repeated day to day response with different individual sensitivity, and when sodium chloride aerosols were added the response of the total respiratory flow resistance was affected in meaningful pattern.From the results above, it can be said that this procedure is a relevant and sensitive method to evaluate a behavior of the respiratory air way in both man and guinea pig particulary in short or long term study of various environmental toxic materials.

Polarographic-coulometric analyzers measurement of low concentrations of sulphur dioxide

Polarographic-coulometric analyzers measurement of low concentrations of sulphur dioxide

The Concurrent Determination of Sulfur Dioxide and Nitrogen Dioxide in the Atmosphere

Concurrent determinations of low concentrations of sulfur dioxide by the conductimetric and fuchsin methods; and of nitrogen dioxide by the Saltzman method, by means of 3 suitably adapted Automatic Impingers at a common atmospheric sampling point in Windsor, Ontario. Conductimetric determinations yielded consistently higher values for sulfur dioxide than the colorimetric method based on the chromogenic reaction of fuchsin, formaldehyde and sulfite. The nitrogen dioxide levels fluctuate similarly to sulfur dioxide and are somewhat lower than the conductimetric sulfur dioxide levels. When the fuchsin values are corrected for the effect of nitrogen dioxide, the colorimetric sulfur dioxide levels are in fairly close agreement with those estimated by the conductimetric method. Data show the hourly variation in Windsor are lower than in Los Angeles.