Science.gov

Sample records for acid gases so2

  1. Removal of Particles and Acid Gases (SO2 or HCl) with a Ceramic Filter by Addition of Dry Sorbents

    SciTech Connect

    Hemmer, G.; Kasper, G.; Wang, J.; Schaub, G.

    2002-09-20

    The present investigation intends to add to the fundamental process design know-how for dry flue gas cleaning, especially with respect to process flexibility, in cases where variations in the type of fuel and thus in concentration of contaminants in the flue gas require optimization of operating conditions. In particular, temperature effects of the physical and chemical processes occurring simultaneously in the gas-particle dispersion and in the filter cake/filter medium are investigated in order to improve the predictive capabilities for identifying optimum operating conditions. Sodium bicarbonate (NaHCO{sub 3}) and calcium hydroxide (Ca(OH){sub 2}) are known as efficient sorbents for neutralizing acid flue gas components such as HCl, HF, and SO{sub 2}. According to their physical properties (e.g. porosity, pore size) and chemical behavior (e.g. thermal decomposition, reactivity for gas-solid reactions), optimum conditions for their application vary widely. The results presented concentrate on the development of quantitative data for filtration stability and overall removal efficiency as affected by operating temperature. Experiments were performed in a small pilot unit with a ceramic filter disk of the type Dia-Schumalith 10-20 (Fig. 1, described in more detail in Hemmer 2002 and Hemmer et al. 1999), using model flue gases containing SO{sub 2} and HCl, flyash from wood bark combustion, and NaHCO{sub 3} as well as Ca(OH){sub 2} as sorbent material (particle size d{sub 50}/d{sub 84} : 35/192 {micro}m, and 3.5/16, respectively). The pilot unit consists of an entrained flow reactor (gas duct) representing the raw gas volume of a filter house and the filter disk with a filter cake, operating continuously, simulating filter cake build-up and cleaning of the filter medium by jet pulse. Temperatures varied from 200 to 600 C, sorbent stoichiometric ratios from zero to 2, inlet concentrations were on the order of 500 to 700 mg/m{sup 3}, water vapor contents ranged from

  2. REMOVAL OF SO2 FROM INDUSTRIAL WASTE GASES

    EPA Science Inventory

    The paper discusses technology for sulfur dioxide (SO2) pollution control by flue gas cleaning (called 'scrubbing') in the utility industry, a technology that has advanced significantly during the past 5 years. Federal Regulations are resulting in increasingly large-scale applica...

  3. SO2 REMOVAL FROM FLUE GASES USING UTILITY SYNTHESIZED ZEOLITES

    SciTech Connect

    Michael Grutzeck

    1999-04-30

    It is well known that natural and synthetic zeolites (molecular sieves) can adsorb gaseous SO{sub 2} from flue gas and do it more efficiently than lime based scrubbing materials. Unfortunately their cost ($500-$800 per ton) has deterred their use in this capacity. It is also known that zeolites are easy to synthesize from a variety of natural and man-made materials. The overall objective of the current work has been to evaluate the feasibility of having a utility synthesize its own zeolites, on-site, from fly ash and other recycled materials and then use these zeolites to adsorb SO{sub 2} from their flue gases. Work to date has shown that the efficiency of the capture process is related to the degree of crystallinity and the type of zeolite that forms in the samples. Normally, those samples cured at 150 C contained a greater proportion of zeolite and as such were more SO{sub 2} adsorptive than their low-temperature counterparts. However, in order for the project to be successful, on site synthesis must remain an option, i.e. 100 C synthesis. In light of this, the experimental focus now has two aspects. First, compositions of the starting materials are being altered by blending the current suite of fly ashes with ground glass cullet and silica fume to promote the formation and growth of well crystallized and highly adsorptive zeolites. Second, greater degrees of reaction at significantly lower temperatures are being promote by ball milling the fly ash prior to use, by the use of more concentrated caustic solutions, and by the addition of zeolite seeds to the reactants. In all cases studies will focus on the effect of structure type and degree of conversion on SO{sub 2} adsorption. Future work will concentrate on the study of the effect of weathering on the suitability of converting fly ash into zeolites. This is an especially important study, considering the acres of fly ash now in storage throughout the US.

  4. SO2 REMOVAL FROM FLUE GASES USING UTILITY SYNTHESIZED ZEOLITES

    SciTech Connect

    MICHAEL GRUTZECK

    1998-10-31

    It is well known that natural and synthetic zeolites (molecular sieves) can adsorb gaseous SO2 from flue gas and do it more efficiently than lime based scrubbing materials. Unfortunately their cost ($500-$800 per ton) has deterred their use in this capacity. It is also known that zeolites are easy to synthesize from a variety of natural and man-made materials. The overall objective of the current work has been to evaluate the feasibility of having a utility synthesize its own zeolites, on-site, from fly ash and other recycled materials and then use these zeolites to adsorb SO2 from their flue gases. Work to date has shown that the efficiency of the capture process is related to the degree of crystallinity and the type of zeolite that forms in the samples. Normally, those samples cured at 150°C contained a greater proportion of zeolite and as such were more SO2 adsorptive than their low-temperature counterparts. However, in order for the project to be successful, on site synthesis must remain an option, i.e. _100°C synthesis. In light of this, the experimental focus now has two aspects. First, compositions of the starting materials are being altered by blending the current suite of fly ashes with other fly ashes, ground glass cullet and silica fume to promote the formation and growth of well crystallized and highly adsorptive zeolites. Second, greater degrees of reaction at significantly lower temperatures are being promote by ball milling the fly ash prior to use, by the use of more concentrated caustic solutions, and by the addition of zeolite seeds to the reactants. In all cases studies will focus on the effect of structure type and degree of conversion on SO2 adsorption. Future work will concentrate on the study of the effect of weathering on the suitability of converting fly ash into zeolites. This is an especially important study, considering the acres of fly ash now in storage throughout the country.

  5. Effect of buffer gases on the performance of SO2 trace measurement based on photoacoustic spectroscopy

    NASA Astrophysics Data System (ADS)

    Mohebbifar, M. R.; Khalilzadeh, J.; Dibaee, B.; Parvin, P.

    2014-07-01

    In this experimental work a laser photoacoustic spectrometer designed and fabricated. System sensitivity for detection of SO2 and NO2 was measured. Resonance frequency variation versus pressure increase of Nitrogen, Argon, Helium and Air buffer gases was studied. Results show that, sensitivity of system for SO2 and NO2 are 353 ppb and 963 ppb respectively. It was shown that resonance frequency for Nitrogen, Argon, and Air buffer gases was not noticeably varied by buffer gas pressure increasing, but for Helium, resonance frequency not only is not in range of three other gases, but also grows by pressure increasing. The system noises were damped preparing two buffer chambers.

  6. Present state of eb removal of so2 and nox from combustion flue gases in Brazil

    NASA Astrophysics Data System (ADS)

    Poli, D. C. R.; Osso, J. A.; Rivelli, V.; Vieira, J. M.; Lugão, A. B.

    1995-09-01

    Environmental problems caused by the increased world energy demands are becoming of growing importance and Brazil is now starting to set limits to the emission of toxic gases. The development of technologies for removal of these gases are therefore necessary and this work shows the present state of the technology of SO2 and NOX removal by electron beam irradiation in Brazil. Data concerning the increasing energy demand in Brazil and the environmental governmental measures are presented, along with the design and implementation of a laboratory pilot plant for the electron beam flue gases removal process located at IPEN-CNEN/SP.

  7. Removal of SO2 from simulated flue gases using non-thermal plasma-based microgap discharge.

    PubMed

    Zhang, Zhitao; Bai, Mindong; Bai, Mindi; Bai, Xiyao; Pan, Qiaoyuan

    2006-06-01

    The removal of sulfur dioxide (SO2) from simulated flue gases streams (N2/O2/H2O/SO2) was experimentally investigated using microgap discharge. In the experiment, the thinner dielectric layers of aluminum oxide (Al2O3) were used to form the microgap discharge. With this physical method, a high concentration of hydroxyl (OH*) radicals were produced using the ionization of O2 and H2O to further the conversion of SO2 into sulfuric acid (H2SO4) at 120 degrees C in the absence of any catalysts and absorbents, which were captured with the electrostatic precipitator (ESP). As a result, the increase of discharge power and concentrations of O2 and H2O increased the production of OH. radicals resulting in enhanced removal of SO2 from gas streams. With the test and analysis, a number of H2SO4 droplets were produced in experiment. Therefore, a new method for removal of SO2 in semidry method without ammonia (NH3) additive was found. PMID:16805405

  8. In-situ characterisation of aerosol and gases (SO2, HCl, ozone) in Mt Etna volcano plume

    NASA Astrophysics Data System (ADS)

    Roberts, Tjarda; Vignelles, Damien; Giudice, Gaetano; Liuzzo, Marco; Aiuppa, Alessandro; Chartier, Michel; Coute, Benoit; Lurton, Thibaut; Renard, Jean-Baptiste

    2014-05-01

    We present findings from a measurement campaign that deployed a range of in-situ real-time atmospheric measurement techniques to characterise aerosols and gases in Mt Etna plume in October 2013. The LOAC (Light Optical Aerosol Counter) instrument for size-resolved particle measurements was deployed alongside two Multi-Gas instruments (measuring SO2, H2S, HCl, CO2) and an ozone sensor. Measurements were performed at the summit craters (in cloudy- and non-cloudy conditions) and in grounding downwind plume on the volcano flank. These high frequency measurements (acid gases: 1 to 0.1 Hz, aerosol: 0.1 Hz) provide a detailed in-situ dataset for time-resolved plume characterisation and volcano monitoring. The LOAC measurement of sized-resolved aerosol (over a 0.2 to 50 µm particle diameter range) alongside SO2 (10's ppbv to 10's ppmv) provides a valuable dataset for determining the volcanic aerosol volume and surface area to SO2 ratios. These parameters are presently poorly defined but are important for atmospheric models of the reactive halogen chemistry that occurs on volcanic aerosol surfaces to convert volcanic HBr into reactive bromine, including BrO. The LOAC's patented optical design can also provide insights into particle properties. The two Multi-Gas SO2 time-series show good agreement, detecting co-varying plume fluctuations in the downwind plume, which also correlate with the LOAC total aerosol volume time-series. An estimate of HCl/SO2 in Etna emissions was made by Multi-Gas electrochemical sensor, using a novel design to limit absorption/desorption effects and low-noise electronics for improved resolution. The detection of volcanic HCl by electrochemical sensor brings new possibilities for Multi-Gas monitoring of volcanic halogen emissions. Electrochemical sensor response times are not instantaneous, particularly for sticky gases such as HCl (T90 ~min), but also even for "fast" response (T90 ~ 10 to 30 s) sensors such as SO2 and H2S. However, in a volcanic

  9. Simultaneous treatment of SO2 containing stack gases and waste water

    NASA Technical Reports Server (NTRS)

    Poradek, J. C.; Collins, D. D. (Inventor)

    1978-01-01

    A process for simultaneously removing sulfur dioxide from stack gases and the like and purifying waste water such as derived from domestic sewage is described. A portion of the gas stream and a portion of the waste water, the latter containing dissolved iron and having an acidic pH, are contacted in a closed loop gas-liquid scrubbing zone to effect absorption of the sulfur dioxide into the waste water. A second portion of the gas stream and a second portion of the waste water are controlled in an open loop gas-liquid scrubbing zone. The second portion of the waste water contains a lesser amount of iron than the first portion of the waste water. Contacting in the openloop scrubbing zone is sufficient to acidify the waste water which is then treated to remove solids originally present.

  10. Effects of SO2 and pH on blood-gas partition coefficients of inert gases.

    PubMed

    Yamaguchi, K; Mori, M; Kawai, A; Asano, K; Takasugi, T; Umeda, A; Yokoyama, T

    1990-01-01

    Potential effects of SO2 and of pH on blood-gas partition coefficients, lambda, for inert gases, including SF6, ethane, cyclopropane, halothane, diethyl ether, acetone and N2, were systematically investigated using human blood. Measurements on lambda were performed at 37 degrees C in conditions of varied SO2 and pH using gas chromatography. Incorporating the experimental data on lambda, multiple inert gas elimination was applied to 18 patients with varied chronic lung diseases, in order to estimate the effects of SO2 and of pH on both inert gas exchange and resultant recovery of VA/Q distribution in the lung. For this purpose, the data obtained by the procedure of multiple inert gas elimination were analyzed with the classical approach but allowance was made for lambda of the indicator gas to vary according to exchange of O2 and of CO2 in the pulmonary capillary. Among the gases studied, ethane, cyclopropane, halothane and diethyl ether showed significantly smaller lambda values in the oxygenated blood than in deoxygenated blood, whereas SF6, acetone and N2 were little dependent on SO2. An increase in lambda was found for ethane and a decrease for halothane with increasing pH in the blood. The other gases were not significantly influenced by pH. In spite of these experimental findings, regional difference of either SO2 or pH in the lung did not exert important influence on the inert gas exchange or on the predicted VA/Q distribution. In conclusion, blood-gas partition coefficients of some inert gases are consistently altered by SO2 and pH, but their possible effects on inert gas exchange seem to be negligible. PMID:1965757

  11. Coal fly ash based carbons for SO2 removal from flue gases.

    PubMed

    Rubio, B; Izquierdo, M T

    2010-07-01

    Two different coal fly ashes coming from the burning of two coals of different rank have been used as a precursor for the preparation of steam activated carbons. The performance of these activated carbons in the SO(2) removal was evaluated at flue gas conditions (100 degrees C, 1000 ppmv SO(2), 5% O(2), 6% H(2)O). Different techniques were used to determine the physical and chemical characteristics of the samples in order to explain the differences found in their behaviour. A superior SO(2) removal capacity was shown by the activated carbon obtained using the fly ash coming from a sub-bituminous-lignite blend. Experimental results indicated that the presence of higher amount of certain metallic oxides (Ca, Fe) in the carbon-rich fraction of this fly ash probably has promoted a deeper gasification in the activation with steam. A more suitable surface chemistry and textural properties have been obtained in this case which explains the higher efficiency shown by this sample in the SO(2) removal. PMID:20167465

  12. Fourier Transform Infrared (FT-IR) Spectroscopy of Atmospheric Trace Gases HCl, NO and SO2

    NASA Technical Reports Server (NTRS)

    Haridass, C.; Aw-Musse, A.; Dowdye, E.; Bandyopadhyay, C.; Misra, P.; Okabe, H.

    1998-01-01

    Fourier Transform Infrared (FT-IR) spectral data have been recorded in the spectral region 400-4000/cm of hydrogen chloride and sulfur dioxide with I/cm resolution and of nitric oxide with 0.25 cm-i resolution, under quasi-static conditions, when the sample gas was passed through tubings of aluminum, copper, stainless steel and teflon. The absorbance was measured for the rotational lines of the fundamental bands of (1)H(35)Cl and (1)H(37)Cl for pressures in the range 100-1000 Torr and for the (14)N(16)O molecule in the range 100-300 Torr. The absorbance was also measured for individual rotational lines corresponding to the three modes of vibrations (upsilon(sub 1) - symmetric stretch, upsilon(sub 2) - symmetric bend, upsilon(sub 3) - anti-symmetric stretch) of the SO2 molecule in the pressure range 25-150 Torr. A graph of absorbance versus pressure was plotted for the observed rotational transitions of the three atmospherically significant molecules, and it was found that the absorbance was linearly proportional to the pressure range chosen, thereby validating Beer's law. The absorption cross-sections were determined from the graphical slopes for each rotational transition recorded for the HCl, NO and SO2 species. Qualitative and quantitative spectral changes in the FT-IR data will be discussed to identify and characterize various tubing materials with respect to their absorption features.

  13. Effect of the greenhouse gases (CO2, H2O, SO2) on Martian paleoclimate

    NASA Technical Reports Server (NTRS)

    Postawko, S. E.; Kuhn, W. R.

    1986-01-01

    There is general agreement that certain surface features on Mars are indicative of the presence of liquid water at various times in the geologic past. In particular, the valley networks are difficult to explain by a mechanism other than the flow of liquid water. It has been suggested in several studies that a thick CO2 atmosphere on Mars early in its history could have provided a greenhouse warming that would have allowed the flow of water either on the surface or just below the surface. However, this effect was examined with a detailed radiation model, and it was found that if reduced solar luminosity early in the history of the solar system is taken into account, even three bars of CO2 will not provide sufficient greeenhouse warming. The addition of water vapor and sulflur dioxide (both plausible gases that may have been emitted by Martian volcanoes) to the atmosphere also fail to warm the surface above 273 K for reduced solar luminosity conditions. The increase in temperature may be large enough, however, for the formation of these features by brines.

  14. E-Beam SO2 and NOx removal from flue gases in the presence of fine water droplets

    NASA Astrophysics Data System (ADS)

    Calinescu, Ioan; Martin, Diana; Chmielewski, Andrezj; Ighigeanu, Daniel

    2013-04-01

    The Electron Beam Flue Gas Treatment (EBFGT) has been proposed as an efficient method for removal of SO2 and NOx many years ago. However, the industrial application of this procedure is limited to just a few installations. This article analyses the possibility of using medium-power EB accelerators for off-gases purification. By increasing electron energy from 0.7 MeV to 1-2 MeV it is possible to reduce the energy losses in the windows and in the air gap between them (transformer accelerators can be applied as well in the process). In order to use these mid-energy accelerators it is necessary to reduce their penetration depth through gas and this can be achieved by increasing the density of the reaction medium by means of dispersing a sufficient amount of fine water droplets (FWD). The presence of FWD has a favorable effect on the overall process by increasing the level of liquid phase reactions. A special reactor was designed and built to test the effect of FWD on the treatment of flue gases with a high concentration of SO2 and NOx using high-energy EBs (9 MeV). By determining the energy efficiency of the process the favorable effect of using FWD and high-energy EB was demonstrated.

  15. A sulfuric-acid process with near-zero SO2 gas emissions

    NASA Astrophysics Data System (ADS)

    Jaeger, W.; Fattinger, V.; Keilpart, T.; Hamel, H.-J.

    1999-05-01

    A sulfuric-acid process has been developed that is able to handle low and variable SO2 concentrations with practically zero SO2 emissions (less than 3 ppm). The plant comprises two stages—a single-bed converter contact plant and a modified tower plant. Acids of 95 98% and/or oleum with up to 32% free SO3 can be produced in the first stage. Off-gas of the first stage is piped to the second stage, where the SO2 is converted to near nontracability while producing 76% strong acid. It is then returned to the contact plant to produce stronger acid or oleum. This process does not generate any additional disposable waste.

  16. SO2 gas adsorption by modified kaolin clays: influence of previous heating and time acid treatments.

    PubMed

    Volzone, Cristina; Ortiga, Jose

    2011-10-01

    Modified kaolin clays were used as adsorbents for SO(2) gas adsorptions. The clays were heated up to 900 °C previous to acid treatments with 0.5 N sulfuric acid solutions at boiling temperature during different times up to 1440 min. Equilibrium adsorption at 25 °C and 0.1 MPa was carried out by using a volumetric apparatus. The samples were characterized by chemical analysis, X-ray diffraction and infrared analysis. The heating of the clays followed by acid treatment improved the adsorption capacity of the kaolin clays. The presence of amorphous silica and hydroxyl in the final products improved SO(2) adsorption capacity. Better properties for SO(2) adsorption were found in kaolin rich in not well ordered kaolinite clay mineral. PMID:21696883

  17. MnFe2O4 as a gas sensor towards SO2 and NO2 gases

    NASA Astrophysics Data System (ADS)

    Rathore, Deepshikha; Mitra, Supratim

    2016-05-01

    The chemical co-precipitation method was used to synthesize MnFe2O4 nanoparticles. Single cubic phase formation of nanoparticles was confirmed by X-ray diffraction technique. The average particle size of MnFe2O4 nanoparticles was found to be 10.7 nm using Scherrer formula. The ultrafine powder of MnFe2O4 nanoparticles was pressed to design pellet of 10 mm diameter and 1mm thickness. Copper electrodes have been deposited on the surface of pellet using silver paste in the form of capacitor. Fabricated gas sensing device of MnFe2O4 nanoparticles was tested towards SO2 and NO2 gases. Cole-Cole plot of MnFe2O4 was investigated with the help of electrochemical workstation. The performance of the sensors including sensitivity, response and recovery time was also determined. It was observed that the MnFe2O4 nanoparticles are more sensible for NO2 gas as compared to SO2 gas.

  18. Gas-phase hydrolysis of triplet SO2: A possible direct route to atmospheric acid formation.

    PubMed

    Donaldson, D James; Kroll, Jay A; Vaida, Veronica

    2016-01-01

    Sulfur chemistry is of great interest to the atmospheric chemistry of several planets. In the presence of water, oxidized sulfur can lead to new particle formation, influencing climate in significant ways. Observations of sulfur compounds in planetary atmospheres when compared with model results suggest that there are missing chemical mechanisms. Here we propose a novel mechanism for the formation of sulfurous acid, which may act as a seed for new particle formation. In this proposed mechanism, the lowest triplet state of SO2 ((3)B1), which may be accessed by near-UV solar excitation of SO2 to its excited (1)B1 state followed by rapid intersystem crossing, reacts directly with water to form H2SO3 in the gas phase. For ground state SO2, this reaction is endothermic and has a very high activation barrier; our quantum chemical calculations point to a facile reaction being possible in the triplet state of SO2. This hygroscopic H2SO3 molecule may act as a condensation nucleus for water, giving rise to facile new particle formation (NPF). PMID:27417675

  19. Gas-phase hydrolysis of triplet SO2: A possible direct route to atmospheric acid formation

    NASA Astrophysics Data System (ADS)

    Donaldson, D. James; Kroll, Jay A.; Vaida, Veronica

    2016-07-01

    Sulfur chemistry is of great interest to the atmospheric chemistry of several planets. In the presence of water, oxidized sulfur can lead to new particle formation, influencing climate in significant ways. Observations of sulfur compounds in planetary atmospheres when compared with model results suggest that there are missing chemical mechanisms. Here we propose a novel mechanism for the formation of sulfurous acid, which may act as a seed for new particle formation. In this proposed mechanism, the lowest triplet state of SO2 (3B1), which may be accessed by near-UV solar excitation of SO2 to its excited 1B1 state followed by rapid intersystem crossing, reacts directly with water to form H2SO3 in the gas phase. For ground state SO2, this reaction is endothermic and has a very high activation barrier; our quantum chemical calculations point to a facile reaction being possible in the triplet state of SO2. This hygroscopic H2SO3 molecule may act as a condensation nucleus for water, giving rise to facile new particle formation (NPF).

  20. Gas-phase hydrolysis of triplet SO2: A possible direct route to atmospheric acid formation

    PubMed Central

    Donaldson, D. James; Kroll, Jay A.; Vaida, Veronica

    2016-01-01

    Sulfur chemistry is of great interest to the atmospheric chemistry of several planets. In the presence of water, oxidized sulfur can lead to new particle formation, influencing climate in significant ways. Observations of sulfur compounds in planetary atmospheres when compared with model results suggest that there are missing chemical mechanisms. Here we propose a novel mechanism for the formation of sulfurous acid, which may act as a seed for new particle formation. In this proposed mechanism, the lowest triplet state of SO2 (3B1), which may be accessed by near-UV solar excitation of SO2 to its excited 1B1 state followed by rapid intersystem crossing, reacts directly with water to form H2SO3 in the gas phase. For ground state SO2, this reaction is endothermic and has a very high activation barrier; our quantum chemical calculations point to a facile reaction being possible in the triplet state of SO2. This hygroscopic H2SO3 molecule may act as a condensation nucleus for water, giving rise to facile new particle formation (NPF). PMID:27417675

  1. Effect of SO2 on oxidation of metallic materials in CO2/H2O‐rich gases relevant to oxyfuel environments

    SciTech Connect

    Huczkowski, P; Olszewski, T; Schiek, M; Lutz, B; Holcomb, G R; Shemet, V; Nowak, W; Meier, G H; Singheiser, L; Quadakkers, W J

    2014-01-01

    In an oxyfuel plant, heat exchanging metallic components will be exposed to a flue gas that contains substantially higher contents of CO2, water vapor, and SO2 than conventionalflue gases. In the present study, the oxidation behavior of the martensitic steel P92 was studied in CO2‐and/or H2O‐rich gas mixtures with and without addition of SO2. For this purpose, the corrosion of P92 at 550 8C up to 1000 h in Ar–H2O–SO2, Ar–CO2–SO2, Ar–CO2–O2–SO2 and simulated oxyfuel gas (Ar–CO2–H2O–O2–SO2) was compared with the behavior in selected SO2‐free gases. The oxidation kinetics were estimated by a number of methods such as optical microscopy, scanning electron microscopy with energy and wave length dispersive X‐ray analysis, glow discharge optical emission spectroscopy, X‐ray diffraction as well as transmission electron microscopy. The experimental results revealed that the effect of SO2 addition on the materials behavior substantially differed, depending on the prevailing base gas atmosphere. The various types of corrosion attack affected by SO2 could not be explained by solely comparing equilibrium activities of the gas atmospheres with thermodynamic stabilities of possible corrosion products. The results were found to be strongly affected by relative rates of reactions of the various gas species occurring within the frequently porous corrosion scales as well as at the scale/gas‐and scale/alloy interfaces.Whereas SO2 addition to Ar–CO2 resulted in formation of an external mixed oxide/sulfide layer, the presence of SO2 in oxyfuel gas and in Ar–H2O–SO2 resulted in Fe‐sulfide formation near the interface between inner and outer oxide layer as well as Cr‐sulfide formation in the alloy. In the latter gases, the presence of SO2 seemed to have no dramatic effect on oxide scale growth rates.

  2. One year observations of atmospheric reactive gases (O3, CO, NOx, SO2) at Jang Bogo base in Terra Nova Bay, Antarctica

    NASA Astrophysics Data System (ADS)

    Siek Rhee, Tae; Seo, Sora

    2016-04-01

    Antarctica is a remote area surrounded by the Southern Ocean and far from the influence of human activities, giving us unique opportunity to investigate the background variation of trace gases which are sensitive to the human activities. Korean Antarctic base, Jang Bogo, was established as a unique permanent overwintering base in Terra Nova Bay in February, 2014. One year later, we installed a package of instruments to monitor atmospheric trace gases at the base, which includes long-lived greenhouse gases, CO2, CH4, and N2O, and reactive gases, O3, CO, NOx, and SO2. The atmospheric chemistry observatory, where these scientific instruments were installed, is located ca. 1 km far from the main building and power plant, minimizing the influence of pollution that may come from the operation of the base. Here we focus on the reactive gases measured in-situ at the base; O3 displays a typical seasonal variation with high in winter and low in summer with seasonal amplitude of ~18 ppb, CO was high in September at ~56 ppb, probably implying the invasion of lower latitude air mass with biomass burning, and low in late summer due to photochemical oxidation. NO did not show clear seasonal variation, but SO2 reveals larger values in summer than in winter. We will discuss potential atmospheric processes behind these first observations of reactive gases in Terra Nova Bay, Antarctica.

  3. [Research on in-situ monitoring of SO2 concentration in the flue gases with DOAS method based on algorithm fusion].

    PubMed

    Tang, Guang-hua; Xu, Chuan-long; Shao, Li-tang; Yang, Dao-ye; Zhou, Bin; Wang, Shi-min

    2009-04-01

    Valuable achievements on differential optical absorption spectroscopy (DOAS) for monitoring atmospheric pollutants gas have been made in the past decades. Based on the idea of setting the threshold according to the maximum value, symbolized as OD'm, of differential optical density, the algorithm of traditional DOAS was combined with the DOAS algorithm based on the kalman filtering to improve the detection limit without losing measurement accuracy in the present article. Two algorithms have different inversion accuracy at the same ratio of signal to noise and the problem of inversion accuracy was well resolved by combining two algorithms at short light path length. Theoretical and experimental research on the concentration measurement of SO2 in the flue gases was carried out at the normal temperature and atmospheric pressure. The research results show that with the OD'm less than 0.0481, the measurement precision is very high for SO2 with the improved DOAS algorithm. The measurement lower limit of SO2 is less than 28.6 mg x m(-3) and the zero drift of the system is less than 2.9 mg x m(-3). If the OD'm is between 0.0481 and 0.9272, the measurement precision is high with the traditional DOAS algorithm. However, if the OD'm is more than 0.922, the errors of measurement results for both two DOAS algorithms are very large and the linearity correction must be performed. PMID:19626898

  4. Reactivity of stabilized Criegee intermediates (sCIs) from isoprene and monoterpene ozonolysis toward SO2 and organic acids

    NASA Astrophysics Data System (ADS)

    Sipilä, M.; Jokinen, T.; Berndt, T.; Richters, S.; Makkonen, R.; Donahue, N. M.; Mauldin, R. L., III; Kurtén, T.; Paasonen, P.; Sarnela, N.; Ehn, M.; Junninen, H.; Rissanen, M. P.; Thornton, J.; Stratmann, F.; Herrmann, H.; Worsnop, D. R.; Kulmala, M.; Kerminen, V.-M.; Petäjä, T.

    2014-11-01

    Oxidation processes in Earth's atmosphere are tightly connected to many environmental and human health issues and are essential drivers for biogeochemistry. Until the recent discovery of the atmospheric relevance of the reaction of stabilized Criegee intermediates (sCIs) with SO2, atmospheric oxidation processes were thought to be dominated by a few main oxidants: ozone, hydroxyl radicals (OH), nitrate radicals and, e.g. over oceans, halogen atoms such as chlorine. Here, we report results from laboratory experiments at 293 K and atmospheric pressure focusing on sCI formation from the ozonolysis of isoprene and the most abundant monoterpenes (α-pinene and limonene), and subsequent reactions of the resulting sCIs with SO2 producing sulfuric acid (H2SO4). The measured total sCI yields were (0.15 ± 0.07), (0.27 ± 0.12) and (0.58 ± 0.26) for α-pinene, limonene and isoprene, respectively. The ratio between the rate coefficient for the sCI loss (including thermal decomposition and the reaction with water vapour) and the rate coefficient for the reaction of sCI with SO2, k(loss) /k(sCI + SO2), was determined at relative humidities of 10 and 50%. Observed values represent the average reactivity of all sCIs produced from the individual alkene used in the ozonolysis. For the monoterpene-derived sCIs, the relative rate coefficients k(loss) / k(sCI + SO2) were in the range (2.0-2.4) × 1012 molecules cm-3 and nearly independent of the relative humidity. This fact points to a minor importance of the sCI + H2O reaction in the case of the sCI arising from α-pinene and limonene. For the isoprene sCIs, however, the ratio k(loss) / k(sCI + SO2) was strongly dependent on the relative humidity. To explore whether sCIs could have a more general role in atmospheric oxidation, we investigated as an example the reactivity of acetone oxide (sCI from the ozonolysis of 2,3-dimethyl-2-butene) toward small organic acids, i.e. formic and acetic acid. Acetone oxide was found to react faster

  5. Reactivity of stabilized Criegee intermediates (sCI) from isoprene and monoterpene ozonolysis toward SO2 and organic acids

    NASA Astrophysics Data System (ADS)

    Sipilä, M.; Jokinen, T.; Berndt, T.; Richters, S.; Makkonen, R.; Donahue, N. M.; Mauldin, R. L., III; Kurten, T.; Paasonen, P.; Sarnela, N.; Ehn, M.; Junninen, H.; Rissanen, M. P.; Thornton, J.; Stratmann, F.; Herrmann, H.; Worsnop, D. R.; Kulmala, M.; Kerminen, V.-M.; Petäjä, T.

    2014-01-01

    Oxidation processes in Earth's atmosphere are tightly connected to many environmental and human health issues and are essential drivers for biogeochemistry. Until the recent discovery of the atmospheric relevance of stabilized Criegee intermediates (sCI), atmospheric oxidation processes were thought to be dominated by few main oxidants: ozone, hydroxyl radicals (OH), nitrate radicals and, e.g. over oceans, halogen atoms such as chlorine. Here, we report results from laboratory experiments at 293 K and atmospheric pressure focusing on sCI formation from the ozonolysis of isoprene and the most abundant monoterpenes (α-pinene and limonene), and subsequent reactions of the resulting sCIs with SO2 producing sulphuric acid (H2SO4). The measured sCI yields were (0.15 ± 0.07), (0.27 ± 0.12) and (0.58 ± 0.26) for the ozonolysis of α-pinene, limonene and isoprene, respectively. The ratio between the rate coefficient for the sCI loss (including thermal decomposition and the reaction with water vapour) and the rate coefficient for the reaction of sCI with SO2, k(loss) / k(sCI + SO2), was determined at relative humidities of 10% and 50%. Observed values represent the average reactivity of all sCIs produced from the individual alkene used in the ozonolysis. For the monoterpene derived sCIs, the relative rate coefficients k(loss) / k(sCI + SO2) were in the range (2.0-2.4) × 1012 molecule cm-3 and nearly independent on the relative humidity. This fact points to a minor importance of the sCI + H2O reaction in the case of the sCI arising from α-pinene and limonene. For the isoprene sCIs, however, the ratio k(loss) / k(sCI + SO2) was strongly dependent on the relative humidity. To explore whether sCIs could have a more general role in atmospheric oxidation, we investigated as an example the reactivity of acetone oxide (sCI from the ozonolysis of 2,3-dimethyl-2-butene) toward small organic acids, i.e. formic and acetic acid. Acetone oxide was found to react faster with the

  6. The effect of functional groups on the SO2 adsorption on carbon surface I: A new insight into noncovalent interaction between SO2 molecule and acidic oxygen-containing groups

    NASA Astrophysics Data System (ADS)

    Liu, Xin; Sun, Fei; Qu, Zhibin; Gao, Jihui; Wu, Shaohua

    2016-04-01

    For the aim to give a new insight into the interactions between SO2 molecule and carbon surface and the effect of acidic oxygen-containing groups, density functional theory and noncovalent interaction analysis in terms of reduced density gradient were employed to investigate both the intensity and type of the interactions. The results indicate that the physisorption of SO2 molecule mainly occurs on the basal plane of pure carbon surface due to van der Waals interactions, however, when acidic oxygen-containing groups were decorated on the carbon surface, they would facilitate SO2 adsorption as a result of hydrogen bonding and dipole-dipole interactions. What's more, these groups could not affect the chemisorption of SO2 remarkably, no matter they are near the adsorption sites or not. In addition, calculation results show that the interactions between SO2 and acidic oxygen-containing groups are in physisorption nature, which challenges a long-held the viewpoint of irreversible chemisorption. Acidic oxygen-containing groups could boost the effective surface area of carbon by enhancing the physisorption on edge positions.

  7. Evaluation of gases, condensates, and SO2 emissions from Augustine volcano, Alaska: the degassing of a Cl-rich volcanic system

    USGS Publications Warehouse

    Symonds, R.B.; Rose, William I., Jr.; Gerlach, T.M.; Briggs, P.H.; Harmon, R.S.

    1990-01-01

    After the March-April 1986 explosive eruption a comprehensive gas study at Augustine was undertaken in the summers of 1986 and 1987. Airborne COSPEC measurements indicate that passive SO2 emission rates declined exponentially during this period from 380??45 metric tons/day (T/D) on 7/24/86 to 27??6 T/D on 8/24/87. These data are consistent with the hypothesis that the Augustine magma reservoir has become more degassed as volcanic activity decreased after the spring 1986 eruption. Gas samples collected in 1987 from an 870??C fumarole on the andesitic lava dome show various degrees of disequilibrium due to oxidation of reduced gas species and condensation (and loss) of H2O in the intake tube of the sampling apparatus. Thermochemical restoration of the data permits removal of these effects to infer an equilibrium composition of the gases. Although not conclusive, this restoration is consistent with the idea that the gases were in equilibrium at 870??C with an oxygen fugacity near the Ni-NiO buffer. These restored gas compositions show that, relative to other convergent plate volcanoes, the Augustine gases are very HCl rich (5.3-6.0 mol% HCl), S rich (7.1 mol% total S), and H2O poor (83.9-84.8 mol% H2O). Values of ??D and ??18O suggest that the H2O in the dome gases is a mixture of primary magmatic water (PMW) and local seawater. Part of the Cl in the Augustine volcanic gases probably comes from this shallow seawater source. Additional Cl may come from subducted oceanic crust because data by Johnston (1978) show that Cl-rich glass inclusions in olivine crystals contain hornblende, which is evidence for a deep source (>25km) for part of the Cl. Gas samples collected in 1986 from 390??-642??C fumaroles on a ramp surrounding the inner summit crater have been oxidized so severely that restoration to an equilibrium composition is not possible. H and O isotope data suggest that these gases are variable mixtures of seawater, FMW, and meteoric steam. These samples are much

  8. Control of acid gases using a fluidized bed adsorber.

    PubMed

    Chiang, Bo-Chin; Wey, Ming-Yen; Yeh, Chia-Lin

    2003-08-01

    During incineration, secondary pollutants such as acid gases, organic compounds, heavy metals and particulates are generated. Among these pollutants, the acid gases, including sulfur oxides (SO(x)) and hydrogen chloride (HCl), can cause corrosion of the incinerator piping and can generate acid rain after being emitted to the atmosphere. To address this problem, the present study used a novel combination of air pollution control devices (APCDs), composed of a fluidized bed adsorber integrated with a fabric filter. The major objective of the work is to demonstrate the performance of a fluidized bed adsorber for removal of acid gases from flue gas of an incinerator. The adsorbents added in the fluidized bed adsorber were mainly granular activated carbon (AC; with or without chemical treatment) and with calcium oxide used as an additive. The advantages of a fluidized bed reactor for high mass transfer and high gas-solid contact can enhance the removal of acid gases when using a dry method. On the other hand, because the fluidized bed can filter particles, fine particles prior to and after passing through the fluidized bed adsorber were investigated. The competing adsorption on activated carbon between different characteristics of pollutants was also given preliminary discussion. The results indicate that the removal efficiencies of the investigated acid gases, SO(2) and HCl, are higher than 94 and 87%, respectively. Thus, a fluidized bed adsorber integrated with a fabric filter has the potential to replace conventional APCDs, even when there are other pollutants at the same time. PMID:12935758

  9. MULTIPOLLUTANT MERCURY AND ACID GASES CONTROL TECHNOLOGY

    EPA Science Inventory

    Plans are to continue testing for acid gas, mercury and NOx removal on baseline CFB operation with lime slurry, then use modified lime hydrates and slurries, and modified calcium silicates as additives for enhanced mercury and SO2 removal. Also, data from a coal-fired utility b...

  10. The Performance of a Novel Synthetic Ca-Based Solid Sorbent Suitable for the Removal of CO2 and SO2 from Flue Gases in a Fluidised Bed

    NASA Astrophysics Data System (ADS)

    Pacciani, R.; Müller, C. R.; Davidson, J. F.; Dennis, J. S.; Hayhurst, A. N.

    The extent and mechanism of the sulphation and carbonation of a limestone, dolomite and chalk, have been compared with a novel, synthetic sorbent (85 wt% CaO and 15 wt% Ca12Al14O33), from experiments in a small, electrically-heated fluidised bed. The sorbent particles were either (i) untreated, but then sieved into two particle sizes and reacted with SO2 of two different concentrations, or (ii) cycled 20 times between (a) carbonation in 14 vol.% CO2 in N2, and (b) calcination, in pure N2, at 750°C. The uptake of SO2 by untreated limestone and dolomite was generally low (<0.2 gSO 2/gsorbent) and dependent on particle size, confirming previous results. In comparison with limestone and dolomite, the untreated chalk and the synthetic sorbent were found to be substantially more reactive with SO2; their final uptake was significantly higher (> 0.5 gSO 2/gsorbent) and essentially independent of the particle size. Hg-intrusion porosimetry, performed on calcined sorbents, revealed that the volume inside the pores of limestone and dolomite was entirely in small pores (<200 nm dia.), confirmed by EDAX analysis. The small pores were easily plugged, hindering the diffusion of SO2 through the particle. On the other hand, calcined chalk and fresh synthetic sorbent possessed large volumes in wide pores (> 200 nm dia.); these bigger pores were not blocked by newly formed CaSO4. This allowed sulphation to proceed uniformly throughout the particle. It was also found that the uptake of SO2 by limestone, dolomite and chalk was substantially lower when the particles had been subjected to cycles of calcination and carbonation in CO2 prior to sulphation; this was attributed to a loss of volume inside the small pores during carbonation and calcination, confirmed by Hg-intrusion porosimetry. The uptake of SO2 by the synthetic sorbent, on the other hand, was much closer to that achieved when it was used untreated, because large pores remained accessible after cycling.

  11. Emission estimates of particulate matter (PM) and trace gases (SO2, NO and NO2) from biomass fuels used in rural sector of Indo-Gangetic Plain, India

    NASA Astrophysics Data System (ADS)

    Saud, T.; Mandal, T. K.; Gadi, Ranu; Singh, D. P.; Sharma, S. K.; Saxena, M.; Mukherjee, A.

    2011-10-01

    In this paper, we present the experimentally determined emission factors and emission estimates of particulate matter (PM), SO2, NO and NO2 emitted from biomass fuels used as energy in rural area of Indo-Gangetic Plain (IGP), India. Biomass fuel samples were collected at district level from this region. The burning of the collected biomass fuels is performed by using the modified dilution sampler based on studies done by Venkataraman et al. (2005). In this study, the emission factor represents the total period of burning including pyrolysis, flaming and smoldering. The average emission factor of PM from dung cake, fuel-wood and crop residue over Delhi, Uttar Pradesh, Punjab, Haryana, Uttarakhand and Bihar are estimated as 16.26 ± 2.29 g kg-1, 4.34 ± 1.06 g kg-1 and 7.54 ± 4.17 g kg-1 respectively. Similarly, the average emission factor of SO2, NO and NO2 from dung cake, fuel-wood and crop residue over this region are also determined (SO2: 0.28 ± 0.09 g kg-1, 0.26 ± 0.10 g kg-1 and 0.27 ± 0.11 g kg-1, NO: 0.27 ± 0.21 g kg-1, 0.41 ± 0.25 g kg-1 and 0.54 ± 0.50 g kg-1 and NO2: 0.31 ± 0.23 g kg-1, 0.35 ± 0.28 g kg-1 and 0.54 ± 0.47 g kg-1 respectively). The emission of PM, SO2, NO and NO2 from biomass fuels used as energy in rural household over, IGP are also estimated in this paper. The result shows the regional emission inventory from Indian scenario with spatial variability.

  12. Simultaneous removal of SO2 and trace As2O3 from flue gas: mechanism, kinetics study, and effect of main gases on arsenic capture.

    PubMed

    Li, Yuzhong; Tong, Huiling; Zhuo, Yuqun; Li, Yan; Xu, Xuchang

    2007-04-15

    Sulfur dioxide (SO2) and trace elements are pollutants derived from coal combustion. This study focuses on the simultaneous removal of S02 and trace arsenic oxide (As2O3) from flue gas by calcium oxide (CaO) adsorption in the moderate temperature range. Experiments have been performed on a thermogravimetric analyzer (TGA). The interaction mechanism between As2O3 and CaO is studied via XRD detection. Calcium arsenate [Ca3(AsO4)2] is found to be the reaction product in the range of 600-1000 degrees C. The ability of CaO to absorb As2O3 increases with the increasing temperature over the range of 400-1000 degrees C. Through kinetics analysis, it has been found that the rate constant of arsenate reaction is much higher than that of sulfate reaction. SO2 presence does not affect the trace arsenic capture either in the initial reaction stage when CaO conversion is relatively low or in the later stage when CaO conversion is very high. The product of sulfate reaction, CaS04, is proven to be able to absorb As2O3. The coexisting CO2 does not weaken the trace arsenic capture either. PMID:17533855

  13. Variations in PM2.5, TSP, BC, and trace gases (NO2, SO2, and O3) between haze and non-haze episodes in winter over Xi'an, China

    NASA Astrophysics Data System (ADS)

    Zhang, Qian; Shen, Zhenxing; Cao, Junji; Zhang, Renjian; Zhang, Leiming; Huang, R.-J.; Zheng, Chenjia; Wang, Linqing; Liu, Suixin; Xu, Hongmei; Zheng, Chunli; Liu, Pingping

    2015-07-01

    To investigate chemical profiles and formation mechanisms of aerosol particles in winter haze events, daily PM2.5 and TSP, 5-min BC, and 15-min trace gases (SO2, NO2, and O3) were measured continuously during Dec. 1-31, 2012 in Xi'an. Chemical analysis was also conducted for nine water-soluble inorganic ions (Na+, NH4+, K+, Mg2+, Ca2+, F-, Cl-, NO3-, and SO42-), organic carbon (OC), elemental carbon (EC), and eight carbon fractions (OC1, OC2, OC3, OC4, EC1, EC2, EC3, and OP) in both PM2.5 and TSP samples. Higher levels of TSP, PM2.5, BC, SO2, and NO2, and lower levels of O3 were observed during haze periods in comparison with non-haze days. The sum of the major secondary ionic species (NH4+, NO3-, and SO42-) in PM2.5 or TSP during haze periods was about 3 times of that during non-haze days. Ion balance calculations showed that PM2.5 samples were acidic during haze periods and were close to neutral during non-haze days. The mean carbon levels were 52.9 μg m-3 and 82.1 μg m-3 in PM2.5 and TSP, respectively, during haze events, which were ∼1.5 times of those during non-haze days. The diurnal variations of BC during non-haze days showed a bimodal distribution with two peaks coincided with traffic rush hours. This was not the case during haze periods, which exhibited a relatively smooth pattern but with high concentration levels, providing evidence of particle accumulation. The ratios of SO42 - /EC, NO3-/EC, and NH4+/EC sharply increased during haze periods, indicating the important pathway of secondary inorganic species formation through aqueous-phase transformation under high relative humidity condition. This study also highlights that wintertime secondary organic carbon (SOC) formation can be an important contributor to carbonaceous aerosol, especially during haze periods.

  14. Removal of acid gases from gas streams

    SciTech Connect

    Nieh, E.C.Y.

    1988-10-04

    This patent describes a method for the purification of a stream of gas comprising a normally gaseous hydrocarbon or synthesis gas contaminated with acid gases which comprises the steps of: countercurrently contacting the gas stream in an absorption zone with a stream of a treating agent consisting essentially of an aqueous solution of N-methyldiethanolamine and imidazole or a methyl substituted imidazole to thereby remove a substantial portion of the acid contaminants from the hydrocarbon gas stream by absorption into the treating agent, discharging an at least partially purified gas stream from the absorption zone, discharging the treating agent enriched with absorbed acid gas components from the absorption zone; and subsequently regenerating the enriched treating agent.

  15. A comparative adsorption study of C2H4 and SO2 on clinoptilolite-rich tuff: effect of acid treatment.

    PubMed

    Erdoğan Alver, Burcu

    2013-11-15

    In this study, ethylene (C2H4) and sulphur dioxide (SO2) adsorption properties of clinoptilolite tuff from Gördes, Turkey and that of acid treated forms were studied at 293K using volumetric apparatus up to 38 and 100 kPa, respectively. In order to consider the effect of acid treatment on structural and gas adsorption properties of zeolite, clinoptilolite mineral was modified with 0.1, 0.5, 1.0 and 2.0M HCl solutions at 70 °C during 3h. XRD, XRF, TG/DTG, DTA and N2 adsorption methods were employed for thermal and structural characterization of clinoptilolite samples before and after the acid treatment. SO2 adsorption capacities (2.356-2.739 mmol/g) of the clinoptilolite samples were superior to those of the C2H4 adsorptions (0.619-1.219 mmol/g). PMID:24100260

  16. SENSITIVITY OF IMPORTANT WESTERN CONIFER SPECIES TO SO2 AND SEASONAL INTERACTION OF ACID FOG AND OZONE

    EPA Science Inventory

    The increased concern for forest health and the role of anthropogenic deposition, including acidic/wet deposition and gaseous air pollutants, has led to the need to understand which forest species face the highest risk from atmospheric deposition. n order to address this issue fo...

  17. Oxidation of Gas-Phase SO2 on the Surfaces of Acidic Microdroplets: Implications for Sulfate and Sulfate Radical Anion Formation in the Atmospheric Liquid Phase.

    PubMed

    Hung, Hui-Ming; Hoffmann, Michael R

    2015-12-01

    The oxidation of SO2(g) on the interfacial layers of microdroplet surfaces was investigated using a spray-chamber reactor coupled to an electrospray ionization mass spectrometer. Four major ions, HSO3(-), SO3(•-), SO4(•-) and HSO4(-), were observed as the SO2(g)/N2(g) gas-mixture was passed through a suspended microdroplet flow, where the residence time in the dynamic reaction zone was limited to a few hundred microseconds. The relatively high signal intensities of SO3(•-), SO4(•-), and HSO4(-) compared to those of HSO3(-) as observed at pH < 3 without addition of oxidants other than oxygen suggests an efficient oxidation pathway via sulfite and sulfate radical anions on droplets possibly via the direct interfacial electron transfer from HSO3(-) to O2. The concentrations of HSO3(-) in the aqueous aerosol as a function of pH were controlled by the deprotonation of hydrated sulfur dioxide, SO2·H2O, which is also affected by the pH dependent uptake coefficient. When H2O2(g) was introduced into the spray chamber simultaneously with SO2(g), HSO3(-) is rapidly oxidized to form bisulfate in the pH range of 3 to 5. Conversion to sulfate was less at pH < 3 due to relatively low HSO3(-) concentration caused by the fast interfacial reactions. The rapid oxidation of SO2(g) on the acidic microdroplets was estimated as 1.5 × 10(6) [S(IV)] (M s(-1)) at pH ≤ 3. In the presence of acidic aerosols, this oxidation rate is approximately 2 orders of magnitude higher than the rate of oxidation with H2O2(g) at a typical atmospheric H2O2(g) concentration of 1 ppb. This finding highlights the relative importance of the acidic surfaces for SO2 oxidation in the atmosphere. Surface chemical reactions on aquated aerosol surfaces, as observed in this study, are overlooked in most atmospheric chemistry models. These reaction pathways may contribute to the rapid production of sulfate aerosols that is often observed in regions impacted by acidic haze aerosol such as Beijing and other

  18. Processes to remove acid forming gases from exhaust gases

    DOEpatents

    Chang, S.G.

    1994-09-20

    The present invention relates to a process for reducing the concentration of NO in a gas, which process comprises: (A) contacting a gas sample containing NO with a gaseous oxidizing agent to oxidize the NO to NO[sub 2]; (B) contacting the gas sample of step (A) comprising NO[sub 2] with an aqueous reagent of bisulfite/sulfite and a compound selected from urea, sulfamic acid, hydrazinium ion, hydrazoic acid, nitroaniline, sulfanilamide, sulfanilic acid, mercaptopropanoic acid, mercaptosuccinic acid, cysteine or combinations thereof at between about 0 and 100 C at a pH of between about 1 and 7 for between about 0.01 and 60 sec; and (C) optionally contacting the reaction product of step (A) with conventional chemical reagents to reduce the concentrations of the organic products of the reaction in step (B) to environmentally acceptable levels. Urea or sulfamic acid are preferred, especially sulfamic acid, and step (C) is not necessary or performed. 16 figs.

  19. Influence of UV rays on Feulgen-type staining with azure A-SO2 prepared with normal hydrochloric acid and sodium thiosulphate.

    PubMed

    Dutt, M K

    1981-07-01

    This communication presents a new method for the preparation of azure A-SO2 for use in Feulgen procedure. The salient feature of this method lies in the fact that azure A-SO2 can be decolourised with normal hydrochloric acid and sodium thiosulphate. The pH of this dye reagent is 2.3 and it is of water colour after filtration. The pH of this dye-reagent is raised to 4.0 with an aqueous solution of sodium hydroxide. Nuclear colouration with this newly developed dye-reagent on acid-hydrolysed DNA of tissue sections becomes fairly satisfactory under the usual laboratory conditions. Staining with this dye-reagent under exposure to UV ray is, however, vastly improved within 5 minutes as compared with the control. Stained sections do withstand treatment in SO2 water without exhibiting any leaching of the dye from the nuclei. Possible mode of action of UV rays in increasing the intensity of staining as well as the speed of reaction has been suggested. PMID:6167839

  20. Processes to remove acid forming gases from exhaust gases

    DOEpatents

    Chang, Shih-Ger

    1994-01-01

    The present invention relates to a process for reducing the concentration of NO in a gas, which process comprises: (A) contacting a gas sample containing NO with a gaseous oxidizing agent to oxidize the NO to NO.sub.2 ; (B) contacting the gas sample of step (A) comprising NO.sub.2 with an aqueous reagent of bisulfite/sulfite and a compound selected from urea, sulfamic acid, hydrazinium ion, hydrazoic acid, nitroaniline, sulfanilamide, sulfanilic acid, mercaptopropanoic acid, mercaptosuccinic acid, cysteine or combinations thereof at between about 0.degree. and 100.degree. C. at a pH of between about 1 and 7 for between about 0.01 and 60 sec; and (C) optionally contacting the reaction product of step (A) with conventional chemical reagents to reduce the concentrations of the organic products of the reaction in step (B) to environ-mentally acceptable levels. Urea or sulfamic acid are preferred, especially sulfamic acid, and step (C) is not necessary or performed.

  1. Fundamental Understanding of the Interaction of Acid Gases with CeO2 : From Surface Science to Practical Catalysis

    DOE PAGESBeta

    Tumuluri, Uma; Rother, Gernot; Wu, Zili

    2016-03-21

    Acid gases including CO2, SO2, and NOx are ubiquitous in large-scale energy applications including heterogeneous catalysis. The adverse environmental and health effects of these acid gases have resulted in high interest in the research and development of technologies to remove or convert these acid gases. The main challenge for the development of these technologies is to develop catalysts that are highly efficient, stable, and cost-effective, and many catalysts have been reported in this regard. CeO2 and CeO2-based catalysts have gained prominence in the removal and conversion of CO2, SO2, and NOx because of their structural robustness and redox and acid–basemore » properties. In this article, we provide a brief overview of the application of CeO2 and CeO2-based catalysts for the removal of CO2, SO2, and NOx gases with an emphasis on the fundamental understanding of the interactions of these acid gases with CeO2. The studies summarized in this review range from surface science using single crystals and thin films with precise crystallographic planes to practical catalysis applications of nanocrystalline and polycrystalline CeO2 materials with defects and dopants. After an introduction to the properties of CeO2 surfaces, their catalytic properties for conversions of different acid gases are reviewed and discussed. Lastly, we find that the surface atomic structure, oxygen vacancies, and surface acid–base properties of CeO2 play vital roles in the surface chemistry and structure evolution during the interactions of acid gases with CeO2 and CeO2-based catalysts.« less

  2. Characterization of trace gases measured over Alberta oil sands mining operations: 76 speciated C2-C10 volatile organic compounds (VOCs), CO2, CH4, CO, NO, NO2, NOy, O3 and SO2

    NASA Astrophysics Data System (ADS)

    Simpson, I. J.; Blake, N. J.; Barletta, B.; Diskin, G. S.; Fuelberg, H. E.; Gorham, K.; Huey, L. G.; Meinardi, S.; Rowland, F. S.; Vay, S. A.; Weinheimer, A. J.; Yang, M.; Blake, D. R.

    2010-08-01

    lower the viscosity of the extracted bitumen (i.e., C4-C9 alkanes, C5-C6 cycloalkanes, C6-C8 aromatics), together with CO; and (2) emissions associated with the mining effort (i.e., CO2, CO, CH4, NO, NO2, NOy, SO2, C2-C4 alkanes, C2-C4 alkenes, C9 aromatics, short-lived solvents such as C2Cl4 and C2HCl3, and longer-lived species such as HCFC-22 and HCFC-142b). Prominent in the second group, SO2 and NO were remarkably enhanced over the oil sands, with maximum enhancements of 38.7 and 5.0 ppbv, or 383 and 319× the local background, respectively. The SO2 enhancements are comparable to maximum values measured in heavily polluted megacities such as Mexico City and are attributed to coke combustion. By contrast, relatively poor correlations between CH4 ethane and propane suggest low natural gas leakage despite its heavy use at the surface mining sites. In addition to the emission of many trace gases, the natural drawdown of OCS by vegetation was absent above the surface mining operations, presumably because of the widespread land disturbance. Unexpectedly, the mixing ratios of α- and β-pinene were much higher over the oil sands (up to 217 and 610 pptv, respectively) than over vegetation in the background boundary layer (20±7 and 84±24 pptv, respectively), and the pinenes correlated well with several industrial tracers that were elevated in the oil sands plumes. Because so few independent measurements from the oil sands mining industry exist, this study provides an important initial characterization of trace gas emissions from oil sands surface mining operations.

  3. Cryogenic process for removing acidic gases from gas mixtures

    SciTech Connect

    Gazzi, L.; Cotone, G.; Ginnasi, A.; Rescalli, C.; Soldati, G.; Vetere, A.

    1985-04-30

    Low temperature treatments are combined with solvent treatments using particularly selective solvents for stripping acidic gases such as carbon dioxide and hydrogen sulphide from natural gas or from synthetic gases. The preferred solvents are a wide range of compounds having an esteric or an etheric function in their molecule, but there are also examples of compounds which have the two functions simultaneously. The stripping process is comparatively simple, is efficient, especially for high contents of acidic gases in the raw gas streams, and is economically acceptable.

  4. Method for removing acid gases from a gaseous stream

    DOEpatents

    Gorin, Everett; Zielke, Clyde W.

    1981-01-01

    In a process for hydrocracking a heavy aromatic polynuclear carbonaceous feedstock containing reactive alkaline constituents to produce liquid hydrocarbon fuels boiling below about 475.degree. C. at atmospheric pressure by contacting the feedstock with hydrogen in the presence of a molten metal halide catalyst, thereafter separating a gaseous stream containing hydrogen, at least a portion of the hydrocarbon fuels and acid gases from the molten metal halide and regenerating the molten metal halide, thereby producing a purified molten metal halide stream for recycle to the hydrocracking zone, an improvement comprising; contacting the gaseous acid gas, hydrogen and hydrocarbon fuels-containing stream with the feedstock containing reactive alkaline constituents to remove acid gases from the acid gas containing stream. Optionally at least a portion of the hydrocarbon fuels are separated from gaseous stream containing hydrogen, hydrocarbon fuels and acid gases prior to contacting the gaseous stream with the feedstock.

  5. Characterization of trace gases measured over Alberta oil sands mining operations: 76 speciated C2-C10 volatile organic compounds (VOCs), CO2, CH4, CO, NO, NO2, NOy, O3 and SO2

    NASA Astrophysics Data System (ADS)

    Simpson, I. J.; Blake, N. J.; Barletta, B.; Diskin, G. S.; Fuelberg, H. E.; Gorham, K.; Huey, L. G.; Meinardi, S.; Rowland, F. S.; Vay, S. A.; Weinheimer, A. J.; Yang, M.; Blake, D. R.

    2010-12-01

    products and/or from the diluent used to lower the viscosity of the extracted bitumen (i.e., C4-C9 alkanes, C5-C6 cycloalkanes, C6-C8 aromatics), together with CO; and (2) emissions associated with the mining effort, such as upgraders (i.e., CO2, CO, CH4, NO, NO2, NOy, SO2, C2-C4 alkanes, C2-C4 alkenes, C9 aromatics, short-lived solvents such as C2Cl4 and C2HCl3, and longer-lived species such as HCFC-22 and HCFC-142b). Prominent in the second group, SO2 and NO were remarkably enhanced over the oil sands, with maximum mixing ratios of 38.7 ppbv and 5.0 ppbv, or 383× and 319× the local background, respectively. These SO2 levels are comparable to maximum values measured in heavily polluted megacities such as Mexico City and are attributed to coke combustion. By contrast, relatively poor correlations between CH4, ethane and propane suggest low levels of natural gas leakage despite its heavy use at the surface mining sites. Instead the elevated CH4 levels are attributed to methanogenic tailings pond emissions. In addition to the emission of many trace gases, the natural drawdown of OCS by vegetation was absent above the surface mining operations, presumably because of the widespread land disturbance. Unexpectedly, the mixing ratios of α-pinene and β-pinene were much greater over the oil sands (up to 217 pptv and 610 pptv, respectively) than over vegetation in the background boundary layer (20±7 pptv and 84±24 pptv, respectively), and the pinenes correlated well with several industrial tracers that were elevated in the oil sands plumes. Because so few independent measurements from the oil sands mining industry exist, this study provides an important initial characterization of trace gas emissions from oil sands surface mining operations.

  6. Cryogenic process for fractionally removing acidic gases from gas mixtures

    SciTech Connect

    Gazzi, L.; Cotone, G.; Ginnasi, A.; Rescalli, C.; Soldati, G.; Vetere, A.

    1985-07-16

    A process is described for stripping acidic gases, mainly hydrogen sulphide and carbon dioxide, from natural gas or synthesis gas, especially when the percentages of such acidic gases are high and the conventional processes become economically objectionable. The process is based on the use of a number of selective solvents, generally belonging to the class of esters, ethers, mixed ester-ethers and lactones, in combination with sequential absorbing cycles which start from the stripping of hydrogen sulphide, and comprise the regeneration of the solvents used by several expansion cycles: H2S and CO2 are recovered and the regenerated solvents recycled.

  7. Isotopic geochemistry of acid thermal waters and volcanic gases from Zaō volcano in Japan

    NASA Astrophysics Data System (ADS)

    Kiyosu, Yasuhiro; Kurahashi, Makoto

    1984-08-01

    The chemical composition and D/H, {18O }/{16O } and {34S }/{32S } ratios have been determined for the acid hot waters and volcanic gases discharging from Zaō volcano in Japan. The thermal springs in Zaō volcano issue acid sulfate-chloride type waters (Zaō) and acid sulfate type waters (Kamoshika). Gases emitted at Kamoshika fumaroles are rich in CO 2, SO 2 and N 2, exclusive of H 2O. Chloride concentrations and oxygen isotope data indicate that the Zaō thermal waters issue a fluid mixture from an acid thermal reservoir and meteoric waters from shallow aquifers. The waters in the Zaō volcanic system have slight isotopic shifts from the respective local meteoric values. The isotopic evidence indicates that most of the water in the system is meteoric in origin. Sulfates in Zaō acid sulfate-chloride waters with δ34S values of around +15‰, are enriched in 34S compared to Zaō H 2S, while the acid sulfate waters at Kamoshika contain supergene light sulfate ( δ 34S = ˜ + 4‰ ) derived from volcanic sulfur dioxide from the volcanic exhalations. The sulfur species in Zaō acid waters are lighter in δ34S than those of other volcanic areas, reflecting the difference in total pressure.

  8. Mechanism of SO2 removal by carbon

    USGS Publications Warehouse

    Lizzio, A.A.; DeBarr, J.A.

    1997-01-01

    The reaction of SO2 with carbon (C) in the presence of O2 and H2O involves a series of reactions that leads to the formation of sulfuric acid as the final product. The rate-determining step in the overall process is the oxidation of SO2 to SO3. Three SO2 oxidation reactions are possible. Adsorbed SO2 (C-SO2) can react either with gas phase O2 or with adsorbed oxygen (C-O complex) to form sulfur trioxide (SO3), or gas phase SO2 can react directly with the C-O complex. In optimizing the SO2 removal capabilities of carbon, most studies only assume a given mechanism for SO2 adsorption and conversion to H2SO4 to be operable. The appropriate SO2 oxidation step and role of the C-O complex in this mechanism remain to be determined. The ultimate goal of this study was to prepare activated char from Illinois coal with optimal properties for low-temperature (80-150 ??C) removal of sulfur dioxide from coal combustion flue gas. The SO2 adsorption capacity of activated char was found to be inversely proportional to the amount of oxygen adsorbed on its surface. A temperature-programmed desorption technique was developed to titrate those sites responsible for adsorption of SO2 and conversion to H2SO4. On the basis of these results, a mechanism for SO2 removal by carbon was proposed. The derived rate expression showed SO2 adsorption to be dependent only on the fundamental rate constant and concentration of carbon atoms designated as free sites. Recent studies indicate a similar relationship exists between the rate of carbon gasification (in CO2 or H2O) and the number of reactive sites as determined by transient kinetics experiments. Utilizing the concept of active or free sites, it was possible to produce a char from Illinois coal having an SO2 adsorption capacity surpassing that of a commercial catalytic activated carbon.

  9. Volcanological applications of SO2 cameras

    NASA Astrophysics Data System (ADS)

    Burton, M. R.; Prata, F.; Platt, U.

    2015-07-01

    Ground-based volcanic gas and ash imaging has the potential to revolutionise the way in which volcanoes are monitored and studied. The ability to track and quantify volcanic emissions in space and time with unprecedented fidelity opens the door to integration with geophysical measurements, allowing breakthroughs in our understanding of the physical processes driving volcanic activity. In May 2013 a European Science Foundation funded Plume Imaging workshop was conducted in Stromboli, Italy, with the objective of bringing the ground-based volcanic plume imaging community together in order to examine the state of the art, and move towards a 'best-practice' for volcanic ash and gas imaging techniques. A particular focus was the development of SO2 imaging systems, or SO2 cameras, with six teams deploying and testing various designs of ultraviolet and infrared-based imaging systems capable of imagining SO2. One conclusion of the workshop was that the term 'SO2 camera' should be applied to any SO2 imaging system, regardless of wavelength of radiation used. This Special Issue on Volcanic Plume Imaging is the direct result of the Stromboli workshop, and together the papers presented here represent the state of the art of ground-based volcano plume imaging science and technology. In this work, we examine in detail the volcanological applications of the SO2 camera, reviewing previous works and placing the new research contained in this Special Issue in context. The development of the SO2 camera, and future developments extending imaging to other volcanic gases, is one of the most exciting and novel research frontiers in volcanology today.

  10. Clostridium stain which produces acetic acid from waste gases

    DOEpatents

    Gaddy, James L.

    1997-01-01

    A method and apparatus for converting waste gases from industrial processes such as oil refining, carbon black, coke, ammonia, and methanol production, into useful products. The method includes introducing the waste gases into a bioreactor where they are fermented to various organic acids or alcohols by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified. In an exemplary recovery process, the bioreactor raffinate is passed through an extraction chamber into which one or more non-inhibitory solvents are simultaneously introduced to extract the product. Then, the product is separated from the solvent by distillation. Gas conversion rates can be maximized by use of centrifuges, hollow fiber membranes, or other means of ultrafiltration to return entrained anaerobic bacteria from the bioreactor raffinate to the bioreactor itself, thus insuring the highest possible cell concentration.

  11. Clostridium strain which produces acetic acid from waste gases

    DOEpatents

    Gaddy, J.L.

    1997-01-14

    A method and apparatus are disclosed for converting waste gases from industrial processes such as oil refining, carbon black, coke, ammonia, and methanol production, into useful products. The method includes introducing the waste gases into a bioreactor where they are fermented to various organic acids or alcohols by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified. In an exemplary recovery process, the bioreactor raffinate is passed through an extraction chamber into which one or more non-inhibitory solvents are simultaneously introduced to extract the product. Then, the product is separated from the solvent by distillation. Gas conversion rates can be maximized by use of centrifuges, hollow fiber membranes, or other means of ultrafiltration to return entrained anaerobic bacteria from the bioreactor raffinate to the bioreactor itself, thus insuring the highest possible cell concentration. 4 figs.

  12. High temperature abatement of acid gases from waste incineration. Part I: experimental tests in full scale plants.

    PubMed

    Biganzoli, Laura; Racanella, Gaia; Rigamonti, Lucia; Marras, Roberto; Grosso, Mario

    2015-02-01

    In recent years, several waste-to-energy plants in Italy have experienced an increase of the concentration of acid gases (HCl, SO2 and HF) in the raw gas. This is likely an indirect effect of the progressive decrease of the amount of treated municipal waste, which is partially replaced by commercial waste. The latter is characterised by a higher variability of its chemical composition because of the different origins, with possible increase of the load of halogen elements such as chlorine (Cl) and fluorine (F), as well as of sulphur (S). A new dolomitic sorbent was then tested in four waste-to-energy plants during standard operation as a pre-cleaning stage, to be directly injected at high temperature in the combustion chamber. For a sorbent injection of about 6 kg per tonne of waste, the decrease of acid gases concentration downstream the boiler was in the range of 7-37% (mean 23%) for HCl, 34-95% (mean 71%) for SO2 and 39-80% (mean 63%) for HF. This pre-abatement of acid gases allowed to decrease the feeding rate of the traditional low temperature sorbent (sodium bicarbonate in all four plants) by about 30%. Furthermore, it was observed by the plant operators that the sorbent helps to keep the boiler surfaces cleaner, with a possible reduction of the fouling phenomena and a consequent increase of the specific energy production. A preliminary quantitative estimate was carried out in one of the four plants. PMID:25465511

  13. SO2 SCRUBBING TECHNOLOGIES: A REVIEW

    EPA Science Inventory

    Electricity generating units may use sulfur dioxide (SO2) scrubbers to meet the requirements of Phase II of the Acid Rain S02 Reduction Program. Additionally, the use of scrubbers can result in reduction of mercury emissions. It is timely, therefore, to review the commercially av...

  14. Process for the removal of acid forming gases from exhaust gases and production of phosphoric acid

    DOEpatents

    Chang, Shih-Ger; Liu, David K.

    1992-01-01

    Exhaust gases are treated to remove NO or NO.sub.x and SO.sub.2 by contacting the gases with an aqueous emulsion or suspension of yellow phosphorous preferably in a wet scrubber. The addition of yellow phosphorous in the system induces the production of O.sub.3 which subsequently oxidizes NO to NO.sub.2. The resulting NO.sub.2 dissolves readily and can be reduced to form ammonium ions by dissolved SO.sub.2 under appropriate conditions. In a 20 acfm system, yellow phosphorous is oxidized to yield P.sub.2 O.sub.5 which picks up water to form H.sub.3 PO.sub.4 mists and can be collected as a valuable product. The pressure is not critical, and ambient pressures are used. Hot water temperatures are best, but economics suggest about 50.degree. C. The amount of yellow phosphorus used will vary with the composition of the exhaust gas, less than 3% for small concentrations of NO, and 10% or higher for concentrations above say 1000 ppm. Similarly, the pH will vary with the composition being treated, and it is adjusted with a suitable alkali. For mixtures of NO.sub.x and SO.sub.2, alkalis that are used for flue gas desulfurization are preferred. With this process, better than 90% of SO.sub.2 and NO in simulated flue gas can be removed. Stoichiometric ratios (P/NO) ranging between 0.6 and 1.5 were obtained.

  15. Treatment of gas streams for removal of acid gases

    SciTech Connect

    Nieh, E.C.Y.

    1987-09-29

    A method is described for the purification of a stream of gas comprising a normally gaseous hydrocarbon or synthesis gas contaminated with acid gases which comprises the steps of: countercurrently contacting the gas stream in an absorption zone with a treating agent to remove a substantial portion of the acid contaminants from the hydrocarbon gas stream by absorption into the treating agent, discharging an at least partially purified hydrocarbon gas stream from the absorption zone, and discharging the treating agent enriched with absorbed acid gas components from the absorption zone. The treating agent consists essentially of an aqueous solution of from about 40 to about 60 wt. % of N-methyldiethanolamine and from about 5 to about 15 wt. % of N,N-diethyl hydroxylamine.

  16. Acid dew and the role of chemistry in the dry deposition of reactive gases to wetted surfaces

    NASA Technical Reports Server (NTRS)

    Chameides, William L.

    1987-01-01

    A formalism is developed to describe the dry deposition of soluble reactive gases to wetted surfaces in terms of the relevant meteorological conditions, the surface roughness, the total amount of liquid water present on the surface, the rate of accumulation of this water, and the species' solubility and reactivity in the surface water. This formulation is then incorporated into a model designed to simulate the generation of acidic dew from the deposition of HNO3, SO2, S(IV) oxidants, H2O2, and O3. Similar to the observations of dew in the continental U.S., the model generates a dewdrop pH of about 4 by the end of the night; the pH can rapidly fall to toxic levels due to rapid evaporation after sunrise. Relatively low deposition velocities are predicted for the SO2 and O3 because of their lower solubilities and hence larger surface resistances than those of the other oxidants. Because the chemical lifetime of the SO2 in the dew is influenced by the atmospheric levels of H2O2, O3, and SO2, the SO2 deposition velocity is a strong function of these species' atmospheric abundances.

  17. Solubility calculations for acid gases in amine blends

    SciTech Connect

    Chakravarty, T.

    1985-01-01

    Treating with alkanolamines is often used to sweeten gases containing only a few parts per million of CO/sub 2/ and H/sub 2/S. Primary amines such as monoethanolamine (MEA) have great affinity for acid gases and are able to produce high purity sweet gas; on the other hand, tertiary amines like methyldiethanolamine (MDEA) have large capacity and are easy to regenerate but, because they do not bind chemically with CO/sub 2/, they are unable to produce a sweetened gas low in this component. Recently, the use of amine blends has become a subject of potentially great commercial importance. Since, the range of possible amines and blend formulations is large, a method for predicting equilibrium solubility is needed. A rigorous thermodynamic model has been developed which uses the extended Debye-Huckel expression, is very similar to one developed for single-amine solutions, and involves the fitting of binary interaction parameters to experimental data. In this work the interaction parameters found to be important in the activity coefficient expression were fitted to each single-acid-gas single-amine subsystem using all published solubility data. The resulting model was then validated by comparing mixed-acid-gas single-amine solubility predictions with published VLE data. MEA-MDEA and DEA-MDEA blends have been studied in detail in this work. It is found that each amine contributes to the overall acid gas solubility in a nonlinear way and that the solubility curves can exhibit maxima and minima as a function of the relative concentrations of the amines.

  18. Validation of the SO2 camera for high temporal and spatial resolution monitoring of SO2 emissions

    NASA Astrophysics Data System (ADS)

    Smekens, Jean-François; Burton, Michael R.; Clarke, Amanda B.

    2015-07-01

    Ground-based measurements of sulfur dioxide (SO2) are a key part of monitoring networks at many volcanic centers. SO2 camera systems represent an attractive addition to conventional spectroscopic methods such as COSPEC or DOAS, because they offer higher sampling rates (up to 1 Hz) and two-dimensional concentration mapping which provides additional contextual information for emission rate calculation and interpretation. Here we present the results of an SO2 camera development project and corresponding validation experiment conducted at a coal-burning power plant in Arizona (USA), where the emissions are independently measured. Emissions of SO2 and other acid gases are regulated in the United States, and hourly data are publicly reported by the US Environmental Protection Agency (EPA). We measured the emissions from two exhaust stacks that had an average combined rate of 8.2 ± 2.1 × 10- 2 kg s- 1 (7 ± 1.8 t d- 1) over a period of 3 h. Masses integrated from our dataset are within 10-20% of the emissions reported by the EPA. The contextual information contained in the images allowed the identification and measurement of the individual plumes from each stack. Measured emission rates decrease with increasing distance from the source, pointing to an apparent loss of SO2 primarily by gas dilution processes, with SO2 concentrations dropping below the detection limit at the edge of the plume at distances > 200 m from the source. Cross-sections very close to the vent (within 50 m; ~ 2 vent diameters), through the optically thick condensing part of the plume, yielded emission rates lower than those reported to the EPA. This near-vent discrepancy is interpreted to be the result of light dilution effects due to attenuation and reflections off the surface of the condensing plume. This work is the first reported validation of emission rate measurements produced by an SO2 camera in a volcano-like geometry, and demonstrates that reliable emission rates can be measured, but also

  19. Changes in SO2 and NO2 Pollution over the Past Decade Observed by Aura OMI

    NASA Astrophysics Data System (ADS)

    Krotkov, N. A.; Li, C.; Lamsal, L. N.; Celarier, E. A.; Marchenko, S. V.; Swartz, W.; Bucsela, E. J.; Fioletov, V.; McLinden, C. A.; Joiner, J.; Bhartia, P. K.; Duncan, B. N.; Dickerson, R. R.

    2014-12-01

    The Ozone Monitoring Instrument (OMI), a NASA partnership with the Netherlands and Finland, flies on the EOS Aura satellite and uses reflected sunlight to measure two critical atmospheric trace gases, nitrogen dioxide (NO2) and sulfur dioxide (SO2), characterizing daily air quality. Both gases and the secondary pollutants they produce (particulate matter, PM2.5, and tropospheric ozone) are among USEPA designated criteria pollutants, posing serious threats to human health and the environment (e.g., acid rain, plant damage, and reduced visibility). A new generation of the OMI standard SO2 and NO2 products (based on critically improved DOAS spectral fitting for NO2 and innovative Principal Component Analysis method for SO2) provides a valuable dataset for studying anthropogenic pollution on local to global scales. Here we highlight some of the OMI observed long-term changes in air quality over several regions. Over the US, average NO2 and SO2 pollution levels have decreased dramatically as a result of both technological improvements (e.g., catalytic converters on cars) and stricter regulations of emissions. We see continued decline in NO2 and SO2 pollution over Europe. Over China OMI observed a ~ 60% increase in NO2 pollution between 2005 and 2013, despite a temporary reversal of the growing trend due to both 2008 Olympic Games and the economic recession in 2009. Chinese SO2 pollution seems to have stabilized since peaking in 2007, probably due to government efforts to curb SO2 emissions from the power sector. We have also observed large increases in both SO2 and NO2 pollution particularly in Eastern India where a number of new large coal power plants have been built in recent years. We expect that further improvements in the OMI NO2 and SO2 products will allow more robust quantification of long-term trends in local to global air quality.

  20. Annular denuders for use in global climate and stratospheric measurements of acidic gases and particles

    NASA Astrophysics Data System (ADS)

    Stevens, Robert K.

    1991-02-01

    Measurements of acidic and basic gases that coexist with fine particle (less than 2.5 micron) may be useful for determining the impact of these species on global climate changes and determining species that influence stratospheric ozone levels. Annular denuders are well suited for this purpose. A new concentric annular denuder system, consisting of a three channel denuder, a Teflon coated cyclone preseparator, and a multistage filter pack was developed, evaluated, and shown to provide reliable atmospheric measurements of SO2, HNO2, HNO3, NH3, SO4(=), NH4(+), NO3(-), and H(+). For example, the precision of the annular denuder for the ambient measurements of HNO3 and nitrates at concentrations between 0.1 to 3 microgram/cu m was + or - 12 and 16 pct., respectively. The 120 x 25 mm three channel denuder is encased in a stainless steel sheath and has annular spaces that are 1 mm wide. This design was shown to have nearly identical capacity for removal of SO2 as conventional 210 x 25 mm single channel denuder configurations. The cyclone preseparator was designed and tested to have a D sub 50 cutoff diameter of 2.5 micron and minimal retention of HNO3.

  1. Indoor exposures to fine aerosols and acid gases.

    PubMed Central

    Koutrakis, P; Brauer, M; Briggs, S L; Leaderer, B P

    1991-01-01

    Indoor exposures to aerosols and gases are associated with both indoor and outdoor air pollution sources. The identification of sources and the assessment of their relative contribution can be a complicated process due to a) the presence of numerous indoor sources, which can vary from building to building; b) the uncertainties associated with the estimation of the impact of outdoor sources on indoor air quality; c) the interactions between pollutants; and d) the importance of reactions between pollutants and indoor surfaces. It is well established that fine particles (diameter less than or equal to 2.5 microns) originating from outdoor sources such as automobiles, oil and coal combustion, incineration, and diverse industrial activities can penetrate into the indoor environment. Indoor/outdoor ratios, usually varying between 0.4 and 0.8, depend on parameters such as particle size and density, air exchange rate, and the surface-to-volume ratio of the indoor environment. Determining fine particle elemental composition makes it possible to identify the contribution of different outdoor sources. This paper focuses on the origin and the concentration of indoor aerosols and acid gases by highlighting the results from two indoor air quality studies. PMID:1821374

  2. Uptake of Ambient Organic Gases to Acidic Sulfate Aerosols

    NASA Astrophysics Data System (ADS)

    Liggio, J.; Li, S.

    2009-05-01

    The formation of secondary organic aerosols (SOA) in the atmosphere has been an area of significant interest due to its climatic relevance, its effects on air quality and human health. Due largely to the underestimation of SOA by regional and global models, there has been an increasing number of studies focusing on alternate pathways leading to SOA. In this regard, recent work has shown that heterogeneous and liquid phase reactions, often leading to oligomeric material, may be a route to SOA via products of biogenic and anthropogenic origin. Although oligomer formation in chamber studies has been frequently observed, the applicability of these experiments to ambient conditions, and thus the overall importance of oligomerization reactions remain unclear. In the present study, ambient air is drawn into a Teflon smog chamber and exposed to acidic sulfate aerosols which have been formed in situ via the reaction of SO3 with water vapor. The aerosol composition is measured with a High Resolution Aerodyne Aerosol Mass Spectrometer (HR-ToF-AMS), and particle size distributions are monitored with a scanning mobility particle sizer (SMPS). The use of ambient air and relatively low inorganic particle loading potentially provides clearer insight into the importance of heterogeneous reactions. Results of experiments, with a range of sulfate loadings show that there are several competing processes occurring on different timescales. A significant uptake of ambient organic gases to the particles is observed immediately followed by a slow shift towards higher m/z over a period of several hours indicating that higher molecular weight products (possibly oligomers) are being formed through a reactive process. The results suggest that heterogeneous reactions can occur with ambient organic gases, even in the presence of ammonia, which may have significant implications to the ambient atmosphere where particles may be neutralized after their formation.

  3. Simultaneous control of acid gases and PAHs using a spray dryer combined with a fabric filter using different additives.

    PubMed

    Liu, Zhen Shu; Wey, Ming Yen; Lin, Chiou Liang

    2002-04-26

    The purpose of this research was to simultaneously evaluate the removal efficiency of acid gases and PAHs from the flue gas emitted by a laboratory incinerator. This flue gas contained dust, acid gases, organics and heavy metals. A spray dryer combined with a fabric filter was used as the air pollution control device (APCD) in this study. The operating conditions investigated included different feedstock additives (polyvinyl chloride (PVC) and NaCl) and spray dryer additives (SiO2, CaCl2 and NaHCO3). The removal efficiency for SO2 could be enhanced by adding inorganic additives, such as SiO2, CaCl2 and NaHCO3. The presence of PVC in the incinerator feedstock also increased the removal efficiency of SO2in the spray dryer. The improved removal of PAHs could be attributed to the addition of feedstock additives (PVC and NaCl) and spray dryer additives (SiO2, CaCl2 and NaHCO3). PMID:11900910

  4. ACID GASES IN CO2-RICH SUBSURFACE GEOLOGIC ENVIRONMENTS

    SciTech Connect

    Chialvo, Ariel A; Vlcek, Lukas; Cole, David

    2013-01-01

    The analysis of species behavior involving dilute fluid environments has been crucial for the advance of modern solvation thermodynamics through molecular-based formalisms to guide the development of macroscopic regression tools in the description of fluid behavior and correlation of experimental data (Chialvo 2013). Dilute fluid environments involving geologic formations are of great theoretical and practical relevance regardless of the thermodynamic state conditions. The most challenging systems are those involving highly compressible and reactive confined environments, i.e., where small perturbations of pressure and/or temperature can trigger considerable density changes. This in turn can alter significantly the species solvation, their preferential solvation, and consequently, their reactivity with one another and with the surrounding mineral surfaces whose outcome is the modification of the substrate porosity and permeability, and ultimately, the integrity of the mineral substrates. Considering that changes in porosity and permeability resulting from dissolution and precipitation phenomena in confined environments are at the core of the aqueous CO2-mineral interactions, and that caprock integrity (e.g., sealing capacity) depends on these key parameters, it is imperative to gain fundamental understanding of the mineral-fluid interfacial phenomena and fluid-fluid equilibria under mineral confinement at subsurface conditions. In order to undertand the potential effects of acid gases as contaminants of supercritical CO2 streams, in the next section we will discuss the thermodynamic behavior of CO2 fluid systems by addressing two crucial issues in the context of carbon capture, utilization and sequestration (CCUS) technologies: (i) Why should we consider (acid gas) CO2 impurities? and (ii) Why are CO2 fluid - mineral interactions of paramount relevance?

  5. Geologic Sequestration of CO2 and Associated H2S and SO2 in Bedded Sandstone-Shale Sequences

    NASA Astrophysics Data System (ADS)

    Xu, T.; Apps, J. A.; Pruess, K.

    2003-12-01

    The injection of CO2 and associated acid gases such as H2S and SO2 into deep sedimentary aquifers is a means by which net anthropogenic atmospheric emissions of greenhouse gases might be reduced. Aquifer host rock aluminosilicate minerals alter very slowly under ambient conditions and their study is not amenable to laboratory experiment. We therefore developed a numerical model to investigate the fate of CO2 and other acid gases in bedded sandstone-shale sequences using hydrogeologic properties and mineral compositions characteristic of Texas Gulf Coast sediments. The simulations were performed using the reactive fluid flow and geochemical transport code, TOUGHREACT, to analyze mass transfer between sandstone and shale layers, the consequent immobilization of gases through mineral precipitation, and the impact of co-contaminated H2S and SO2 gases on CO2 sequestration. The gas sequestration capacity by both aqueous and mineral phases was evaluated. Porosity changes due to mineral dissolution and precipitation were also monitored. The simulations provide useful insights into potential sequestration processes, and their controlling conditions and parameters during long-term containment of acid gases in deep sedimentary formations.

  6. Episodic vs. epochal release of SO2 on Mars

    NASA Technical Reports Server (NTRS)

    Postawko, S. E.; Fanale, F. P.; Zent, A. P.

    1987-01-01

    Erosion of the Martian surface by the flow of liquid water has apparently taken place at different times and locations on the planet. Many attempts were made to explain the valley networks by invoking a strong atmospheric CO2/H2O greenhouse early in the history of the planet. It was assumed that the large amounts of CO2 necessary to cause the greenhouse would have disappeared due to carbonate formation. Carbonates have yet to be positively identified. Volcanism has occurred throughout much of the history of Mars. Presumably gases such as SO2 were released along with CO2 and H2O. Estimates of amounts and rates with which SO2 were released into the Martian atmosphere, and how this would effect the global climate were made. Studies are continuing on the effects of SO2 and other volcanic gases on Martian climatic history.

  7. Contamination monitoring for ammonia, amines, and acid gases utilizing ion mobility spectroscopy (IMS)

    NASA Astrophysics Data System (ADS)

    Bacon, Tad; Webber, Kurt; Carpio, Ronald A.

    1998-06-01

    The effect of ammonia (NH3) and n-methyl pyrrolidinone (NMP) contamination on chemically amplified DUV resists is well documented. Other amines and related compounds are under suspicion as well. In addition, the concentration levels that are of concern have steadily decreased from approximately 10 ppbv down to levels as low as 0.1 ppbv. While some techniques such as ion chromotagraphy (IC) have been demonstrated to have limits of detection at these levels, the analysis times are rather long and cumbersome. This paper describes the use of IMS to perform these measurements, in a totally automated, continuous instrument. IMS is a simplified time-of-flight technique that requires no liquid reagents and has been demonstrated to be a reliable method for monitoring for ammonia and NMP in cleanrooms. This paper demonstrates the ability of the technique to monitor for amines such as dimethylamine, methylamine, methanolamine, ethanolamine, diethanolamine, butylamine and others. Detection limits of 0.1 ppbv and below are clearly demonstrated. Also discussed are methods of monitoring multiple points with a single analyzer. Ability to detect corrosive gases such as hydrogen fluoride (HF), hydrogen chloride (HCl), sulfur dioxide (SO2), sulfur trioxide (SO3), nitrogen dioxide (NO2), chlorine (Cl2), bromine (Br2), phosphoric acid (H3PO4) are also demonstrated.

  8. Vapor-liquid equilibria in the system ethanethiol + methyldiethanolamine + water in the presence of acid gases

    SciTech Connect

    Jou, F.Y.; Mather, A.E.; Schmidt, K.A.G.; Ng, H.J.

    1999-07-01

    This investigation was carried out to determine the solubility of ethanethiol in a methyldiethanolamine (MDEA) solution. Measurements were made in the absence of acid gases, H{sub 2}H and CO{sub 2}, with individual acid gases present, and with mixtures of acid gases present. Experiments with an aqueous solution of 50 mass % MDEA were carried out at 40 and 70 C. The total pressure for most of the experiments was 6,890 kPa, which was maintained by methane. Partial pressures of ethanethiol ranged from 0.2 to 15 kPa.

  9. Monitoring of volcanic emissions of SO2 and ash

    NASA Astrophysics Data System (ADS)

    Theys, Nicolas; Clarisse, Lieven; Brenot, Hugues; van Gent, Jeroen; Campion, Robin; van der A, Ronald; Valks, Pieter; Corradini, Stefano; Merucci, Luca; Van Roozendael, Michel; Coheur, Pierre-François; Hurtmans, Daniel; Clerbaux, Cathy; Tait, Steve; Ferrucci, Fabrizio

    2013-04-01

    Volcanic eruptions can emit large quantities of fine particles (ash) into the atmosphere as well as several trace gases, such as water vapour, carbon dioxide, sulphur species (SO2, H2S) and halogens (HCl, HBr, HF). These volcanic ejecta can have a considerable impact on the atmosphere, human health and society. Volcanic ash in particular is known to be a major threat for aviation, especially after dispersion over long distances (>1000 km) from the erupting volcano. In this respect, the continuous monitoring of volcanic ash from space is playing an essential role for the mitigation of aviation hazards. Compared to ash, SO2 is less critical for aviation safety, but is much easier to measure. Therefore, SO2 observations are often use as a marker of volcanic ash in the atmosphere. Moreover, SO2 yields information on the processes occurring in the magmatic system and is used as a proxy for the eruptive rate. In this presentation we give an overview of recent developments of the Support to Aviation Control Service (SACS). The focus is on the near-real time detection and monitoring of volcanic plumes of ash and SO2 using polar-orbiting instruments GOME-2, OMI, IASI and AIRS. The second part of the talk is dedicated to the determination of volcanic SO2 fluxes from satellite measurements. We review different techniques and investigate the temporal evolution of the total emissions of SO2 for recent volcanic events.

  10. STATUS OF SO2 SCRUBBING TECHNOLOGIES

    EPA Science Inventory

    The paper presents the extent of current sulfur dioxide (SO2) scrubber applications on electricity generating units in the U.S. and abroad. The technical performance of recent SO2 scrubber installations is discussed. Recently reported technical innovations to SO2 scrubbing tech...

  11. Radiolysis gases from nitric acid solutions containing HSA and HAN

    SciTech Connect

    Smith, J.R.

    1994-10-28

    The concentration of hydrogen (H{sub 2}) in the radiolytically produced off-gas from 2.76-4.25M HNO{sub 3}/PU solutions has been found to be greatly reduced in the presence of sulfamic acid (HSA) and hydroxylamine nitrate (HAN). The H{sub 2} concentration ([H{sub 2}]) is reduced from 35 percent to about 4 percent by dilution caused from an increase in the production rates of nitrogen (N{sub 2}), nitrous oxide (N{sub 2}O), and oxygen (O{sub 2}) gases. The generation rate of H{sub 2} was not affected by HSA or HAN giving a measured radiolytic yield, G(H{sub 2}), value of 0.201 molecules/100 eV for 2.765M NO{sub 3}{sup -} solution (a value of 0.213 is predicted from previous data). The G(H{sub 2}) values are dependent on the solution nitrate concentration ([NO{sub 3}{sup -}]). The generation rates of N{sub 2}, N{sub 2}O, and O{sub 2} are not dependent on the [NO{sub 3}{sup -}] in this narrow range, but are dependent on the presence of HSA and the concentration of HAN. The percentage [H{sub 2}] for the 2.5 to 3.0M NO{sub 3}{sup -} range expected in the off- from the FB-Line Pu{sup +3} Hold Tanks is conservatively estimated to be about 3.5 to 4.5 % for Pu + 3 solutions initially containing 0.023M HAN/0.165M HSA. The upper limit [H{sub 2}] may actually be about 4.1 % (4.3 % at 90 % confidence limits) but more {open_quotes}initial{close_quotes} off-gas rate data is needed at about 2.9M [NO{sub 3}{sup -}] in Pu{sup +3} solution for verification. Addition of ascorbic acid had no effect on the off-gas rate of Pu{sup +3} solutions containing HSA and NO{sub 3}{sup -} concentrations higher than those expected in the hold tanks. The maximum {open_quotes}hold time{close_quotes} for 50 grams/liter Pu{sup +3}/0.165M HSA/0.023M HAN/2.5-3.0M HNO{sub 3} solution is 20.3{+-}2.1 days. After this time the HSA initially present will become exhausted and the [H{sub 2}] will increase to 35 %. This hold time may be longer in [NO{sub 3}{sup -}] < 3.0M, but again more study is needed.

  12. On the SO2 problem of solid fuel combustion

    NASA Astrophysics Data System (ADS)

    Boyadjiev, Chr.

    2014-09-01

    Many companies use two-phase absorbents (CaCO3 suspension) for waste gases purification from SO2. A qualitative theoretical analysis of the absorption kinetics in the cases of two-phase absorbent, using the convection-diffusion type of model, is presented. It is shown that the low CaCO3 concentration lead to very small chemical reaction rate and as a result the absorption rate is limited by the physical absorption of SO2 in water, i.e. the process efficiency is very small. An average concentration model for quantitative analysis of the absorption process and an iterative numerical algorithm for the model equations solution is proposed.

  13. Process for the removal of acid forming gases from exhaust gases

    DOEpatents

    Chang, S.G.; Liu, D.K.

    1992-11-17

    Exhaust gases are treated to remove NO or NO[sub x] and SO[sub 2] by contacting the gases with an aqueous emulsion or suspension of yellow phosphorus preferably in a wet scrubber. The pressure is not critical, and ambient pressures are used. Hot water temperatures are best, but economics suggest about 50 C is attractive. The amount of yellow phosphorus used will vary with the composition of the exhaust gas, less than 3% for small concentrations of NO, and 10% or higher for concentrations above say 1000 ppm. Similarly, the pH will vary with the composition being treated, and it is adjusted with a suitable alkali. For mixtures of NO[sub x] and SO[sub 2], alkalis that are used for flue gas desulfurization are preferred. With this process, 100% of the by-products created are usable, and close to 100% of the NO or NO[sub x] and SO[sub 2] can be removed in an economic fashion. 9 figs.

  14. Process for the removal of acid forming gases from exhaust gases

    DOEpatents

    Chang, Shih-Ger; Liu, David K.

    1992-01-01

    Exhaust gases are treated to remove NO or NO.sub.x and SO.sub.2 by contacting the gases with an aqueous emulsion or suspension of yellow phosphorus preferably in a wet scrubber. The pressure is not critical, and ambient pressures are used. Hot water temperatures are best, but economics suggest about 50.degree. C. are attractive. The amount of yellow phosphorus used will vary with the composition of the exhaust gas, less than 3% for small concentrations of NO, and 10% or higher for concentrations above say 1000 ppm. Similarly, the pH will vary with the composition being treated, and it is adjusted with a suitable alkali. For mixtures of NO.sub.x and SO.sub.2, alkalis that are used for flue gas desulfurization are preferred. With this process, 100% of the by-products created are usable, and close to 100% of the NO or NO and SO.sub.2 can be removed in an economic fashion.

  15. Atmospheric SO2 measurements at the Brazilian Antarctic station

    NASA Astrophysics Data System (ADS)

    Mariano, Ericka; Paes Leme, Neusa Maria; Alvala, Plinio

    For a better comprehension of the atmospheric chemical and radiative properties, it is necessary to understand the behavior of trace gases and aerosols; some of these species are not well studied. Sulphur dioxide (SO2) is found in the troposphere, as a result of both natural and anthropogenic emissions. To study the behavior of this gas in the Antarctic continent, the data collected by the Brewer Spectrophotometer installed in the Brazilian Antarctic Station Comandante Ferraz (62o 05'S, 58o 24'W) were used. With this ground-based instrument, the total column of SO2 was measured from the beginning of springtime, to the beginning of summer, in the years from 2003 to 2009. It was possible to observe that the total columns of SO2 did not show any differences in the time of the development of the ozone hole, as comparing to other periods. The main sources of anthropogenic SO2 pollution in this region are the generation of energy, the operations with ships, and the burning of garbage, being a punctual impact. The natural generation of SO2 in this region is mainly related to the conversion of DMS (dimethyl sulfide) emitted by the ocean. In a few days, the SO2 total column exceeded the values considered normal for remote regions (¿2UD), and these high concentrations must have their sources identified and monitored.

  16. [Aqueous oxidation of SO2 with microbial method].

    PubMed

    Jiang, Wen-ju; Tong, Xiao-shuang; Zhu, Xiao-fan; Zhu, Lian-xi; Jin, Yan

    2006-05-01

    The desulfurizations in dilute sulfuric acid solution, acidic ferric solution, acidic ferrous solution, microbial solution (Thiobacillus ferrooridans) and microbial culture medium solution were conducted to discuss biodesulfurization mechanism. The effect of Fe3+ concentration, Fe2+ concentration, SO2 concentration and temperature on biodesulfurization was examined on SO4(2-) concentration in the solution. Biodesulfurization has two ways: direct oxidation and indirect oxidation. In direct oxidation, Thiobacillus ferrooxridans oxidize S(IV) to S(VI). In indirect oxidation, Thiobacillus ferrooxidans can fast transform Fe2+ to Fe3+ in acidic conditions and then increase aqueous catalytic oxidation capacity of Fe3+ on SO2. It shows that indirect oxidation is the dominant way in biodesulfurization process. The desulfurization efficiency increase with concentration of Fe3+ or Fe2+ in the range of 0-1.2 g/L. Thiobacillus ferrooxidans enforce oxidation of SO2 in Fe3+ /Fe2+ system. The removal of SO2 decrease as concentration of SO2 increase, however, concentrations of SO4(2-) in the solution do not vary much in different inlet concentrations of SO2. Temperature has important effect on biodesulfurization. The optimal operative temperature range is 30-40 degrees C. PMID:16850819

  17. Understanding SO2 Capture by Ionic Liquids.

    PubMed

    Mondal, Anirban; Balasubramanian, Sundaram

    2016-05-19

    Ionic liquids have generated interest for efficient SO2 absorption due to their low vapor pressure and versatility. In this work, a systematic investigation of the structure, thermodynamics, and dynamics of SO2 absorption by ionic liquids has been carried out through quantum chemical calculations and molecular dynamics (MD) simulations. MP2 level calculations of several ion pairs complexed with SO2 reveal its preferential interaction with the anion. Results of condensed phase MD simulations of SO2-IL mixtures manifested the essential role of both cations and anions in the solvation of SO2, where the solute is surrounded by the "cage" formed by the cations (primarily its alkyl tail) through dispersion interactions. These structural effects of gas absorption are substantiated by calculated Gibbs free energy of solvation; the dissolution is demonstrated to be enthalpy driven. The entropic loss of SO2 absorption in ionic liquids with a larger anion such as [NTf2](-) has been quantified and has been attributed to the conformational restriction of the anion imposed by its interaction with SO2. SO2 loading IL decreases its shear viscosity and enhances the electrical conductivity. This systematic study provides a molecular level understanding which can aid the design of task-specific ILs as electrolytes for efficient SO2 absorption. PMID:27119562

  18. Aura OMI Observations of Global SO2 and NO2 Pollution from 2005 to 2013

    NASA Technical Reports Server (NTRS)

    Krotkov, Nickolay; Li, Can; Lamsal, Lok; Celarier, Edward; Marchenko, Sergey; Swartz, William H.; Bucsela, Eric; Fioletov, Vitali; McLinden, Chris; Joiner, Joanna; Bhartia, Pawan K.; Duncan, Bryan; Dickerson, Russ

    2014-01-01

    The Ozone Monitoring Instrument (OMI), a NASA partnership with the Netherlands and Finland, flies on the NASA Aura satellite and uses reflected sunlight to measure the two critical atmospheric trace gases: nitrogen dioxide (NO2) and sulfur dioxide (SO2) characterizing daily air quality. Both gases and the secondary pollutants they produce (particulate matter, PM2.5, and tropospheric ozone) are USEPA designated criteria pollutants, posing serious threats to human health and the environment (e.g., acid rain, plant damage and reduced visibility). Our group at NASA GSFC has developed and maintained OMI standard SO2 and NO2 data products. We have recently released an updated version of the standard NO2 L2 and L3 products (SP v2.1) and continue improving the algorithm. We are currently in the process of releasing next generation pollution SO2 product, based on an innovative Principal Component Analysis (PCA) algorithm, which greatly reduces the noise and biases. These new standard products provide valuable datasets for studying anthropogenic pollution on local to global scales. Here we highlight some of the OMI observed changes in air quality over several regions. Over the US average NO2 and SO2 pollution levels had decreased dramatically as a result of both technological improvements (e.g., catalytic converters on cars) and stricter regulations of emissions. We see continued decline in pollution over Europe. Over China OMI observed an increase of about 60 percent in NO2 pollution between 2005 and 2013, despite a temporal reversal of the growing trend due to both 2008 Olympic Games and the economic recession in 2009. Chinese SO2 pollution seems to have stabilized since peaking in 2007, probably due to government efforts to curb SO2 emissions from the power sector. We have also observed large increases in both SO2 and NO2 pollution particularly in Eastern India where a number of large new coal power plants had been built in recent years. We expect that further

  19. Process for recovery of sulfur from acid gases

    DOEpatents

    Towler, Gavin P.; Lynn, Scott

    1995-01-01

    Elemental sulfur is recovered from the H.sub.2 S present in gases derived from fossil fuels by heating the H.sub.2 S with CO.sub.2 in a high-temperature reactor in the presence of a catalyst selected as one which enhances the thermal dissociation of H.sub.2 S to H.sub.2 and S.sub.2. The equilibrium of the thermal decomposition of H.sub.2 S is shifted by the equilibration of the water-gas-shift reaction so as to favor elemental sulfur formation. The primary products of the overall reaction are S.sub.2, CO, H.sub.2 and H.sub.2 O. Small amounts of COS, SO.sub.2 and CS.sub.2 may also form. Rapid quenching of the reaction mixture results in a substantial increase in the efficiency of the conversion of H.sub.2 S to elemental sulfur. Plant economy is further advanced by treating the product gases to remove byproduct carbonyl sulfide by hydrolysis, which converts the COS back to CO.sub.2 and H.sub.2 S. Unreacted CO.sub.2 and H.sub.2 S are removed from the product gas and recycled to the reactor, leaving a gas consisting chiefly of H.sub.2 and CO, which has value either as a fuel or as a chemical feedstock and recovers the hydrogen value from the H.sub.2 S.

  20. New developments to improve SO2 cameras

    NASA Astrophysics Data System (ADS)

    Luebcke, P.; Bobrowski, N.; Hoermann, C.; Kern, C.; Klein, A.; Kuhn, J.; Vogel, L.; Platt, U.

    2012-12-01

    The SO2 camera is a remote sensing instrument that measures the two-dimensional distribution of SO2 (column densities) in volcanic plumes using scattered solar radiation as a light source. From these data SO2-fluxes can be derived. The high time resolution of the order of 1 Hz allows correlating SO2 flux measurements with other traditional volcanological measurement techniques, i.e., seismology. In the last years the application of SO2 cameras has increased, however, there is still potential to improve the instrumentation. First of all, the influence of aerosols and ash in the volcanic plume can lead to large errors in the calculated SO2 flux, if not accounted for. We present two different concepts to deal with the influence of ash and aerosols. The first approach uses a co-axial DOAS system that was added to a two filter SO2 camera. The camera used Filter A (peak transmission centred around 315 nm) to measures the optical density of SO2 and Filter B (centred around 330 nm) to correct for the influence of ash and aerosol. The DOAS system simultaneously performs spectroscopic measurements in a small area of the camera's field of view and gives additional information to correct for these effects. Comparing the optical densities for the two filters with the SO2 column density from the DOAS allows not only a much more precise calibration, but also to draw conclusions about the influence from ash and aerosol scattering. Measurement examples from Popocatépetl, Mexico in 2011 are shown and interpreted. Another approach combines the SO2 camera measurement principle with the extremely narrow and periodic transmission of a Fabry-Pérot interferometer. The narrow transmission window allows to select individual SO2 absorption bands (or series of bands) as a substitute for Filter A. Measurements are therefore more selective to SO2. Instead of Filter B, as in classical SO2 cameras, the correction for aerosol can be performed by shifting the transmission window of the Fabry

  1. Distillation and detection of SO2 using a microfluidic chip.

    PubMed

    Ju, Wei-Jhong; Fu, Lung-Ming; Yang, Ruey-Jen; Lee, Chia-Lun

    2012-02-01

    A miniaturized distillation system is presented for separating sulfurous acid (H(2)SO(3)) into sulfur dioxide (SO(2)) and water (H(2)O). The major components of the proposed system include a microfluidic distillation chip, a power control module, and a carrier gas pressure control module. The microfluidic chip is patterned using a commercial CO(2) laser and comprises a serpentine channel, a heating zone, a buffer zone, a cooling zone, and a collection tank. In the proposed device, the H(2)SO(3) solution is injected into the microfluidic chip and is separated into SO(2) and H(2)O via an appropriate control of the distillation time and temperature. The gaseous SO(2) is then transported into the collection chamber by the carrier gas and is mixed with DI water. Finally, the SO(2) concentration is deduced from the absorbance measurements obtained using a spectrophotometer. The experimental results show that a correlation coefficient of R(2) = 0.9981 and a distillation efficiency as high as 94.6% are obtained for H(2)SO(3) solutions with SO(2) concentrations in the range of 100-500 ppm. The SO(2) concentrations of two commercial red wines are successfully detected using the developed device. Overall, the results presented in this study show that the proposed system provides a compact and reliable tool for SO(2) concentration measurement purposes. PMID:22159042

  2. Solubility of acid gases in a mixed solvent

    SciTech Connect

    MacGregor, R.J.; Mather, A.E.

    1987-01-01

    The solubility of hydrogen sulphide and carbon dioxide and their mixtures has been measured at 40/sup 0/ and 100/sup 0/C in a mixed solvent consisting of 20.9 wt% (2.0 M) MDEA (methyldiethanolamine), 30.5 wt% sulfolane, and 48.6 wt% water. The results have been compared with those for aqueous 2.0 M MDEA and an analogous mixed solvent, containing AMP (2-amino-2-methyl-1-propanol), which are available in the literature. At solution loadings less than 1 mol acid gas/mol MDEA, the solubility of the acid gas was lower in the mixed solvent that in the corresponding aqueous MDEA solvent; at solution loadings greater than 1 mol acid gas/mol MDEA, the reverse was true. At all loadings and at both temperatures studied, the mixed MDEA solvent absorbed equal or lesser quantities of acid gas than the comparable mixed AMP solvent. However, the shapes of the solubility curves show that the mixed MDEA solvent would be a better choice for certain industrial applications. These data were used to modify the solubility model of Deshmukh and Mather to account for the mixed solvent effects on the system thermodynamics. Results show that the model is useful as a first approximation in predicting acid gas solubilities; agreement with experiment was generally found to be within +-15%.

  3. Interspecific Variation in SO2 Flux 1

    PubMed Central

    Olszyk, David M.; Tingey, David T.

    1985-01-01

    The objective of this study was to clarify the relationships among stomatal, residual, and epidermal conductances in determining the flux of SO2 air pollution to leaves. Variations in leaf SO2 and H2O vapor fluxes were determined using four plant species: Pisum sativum L. (garden pea), Lycopersicon esculentum Mill. flacca (mutant of tomato), Geranium carolinianum L. (wild geranium), and Diplacus aurantiacus (Curtis) Jeps. (a native California shrub). Fluxes were measured using the mass-balance approach during exposure to 4.56 micromoles per cubic meter (0.11 microliters per liter) SO2 for 2 hours in a controlled environmental chamber. Flux through adaxial and abaxial leaf surfaces with closed stomata ranged from 1.9 to 9.4 nanomoles per square meter per second for SO2, and 0.3 to 1.3 millimoles per square meter per second for H2O vapor. Flux of SO2 into leaves through stomata ranged from ∼0 to 8.5 (dark) and 3.8 to 16.0 (light) millimoles per square meter per second. Flux of H2O vapor from leaves through stomata ranged from ∼0 to 0.6 (dark) to 0.4 to 0.9 (light) millimole per square meter per second. Lycopersicon had internal flux rates for both SO2 and H2O vapor over twice as high as for the other species. Stomatal conductance based on H2O vapor flux averaged from 0.07 to 0.13 mole per square meter per second among the four species. Internal conductance of SO2 as calculated from SO2 flux was from 0.04 mole per square meter per second lower to 0.06 mole per square meter per second higher than stomatal conductance. For Pisum, Geranium, and Diplacus stomatal conductance was the same or slightly higher than internal conductance, indicating that, in general, SO2 flux could be predicted from stomatal conductance for H2O vapor. However, for the Lycopersicon mutant, internal leaf conductance was much higher than stomatal conductance, indicating that factors inside leaves can play a significant role in determining SO2 flux. PMID:16664551

  4. Co-Sequestration Geochemical Modeling: Simple Brine Solution + CO2-O2-SO2

    NASA Astrophysics Data System (ADS)

    Verba, C.; Kutchko, B. G.; Reed, M. H.

    2012-12-01

    Class H well cement (LaFarge) was exposed to supercritical CO2 to evaluate the impact of brine chemistry on the well cement. Simulated experimental downhole conditions include a pressure of 28.6 MPa and a temperature of 50oC. Brine composition was formulated from the NETL NATCARB database, resulting in a simple solution of 1 M (NaCl, MgCl2, CaCl2). It was determined that the brine chemistry plays a vital role in determining the degree and type of alteration of cement in carbon sequestration conditions. The implications of co-sequestration (CO2/O2/SO2 mixtures) from of oxy-fueled combustion, coal gasification and sour gas have been considered. Geochemical modeling was conducted to understand the interaction between formation brine, cement and co-contaminant gases, using a gas composition of 95.5% CO2, 4% O2, and 1.5% SO2. The modeling results are significant in determining the validity of co-sequestering coal flue gas containing SOx gases or sour hydrocarbon gas which could potentially produce pyrite or other sulfur-bearing species in the cement via mineralization trapping. Thermodynamic components of aqueous species, gases, and minerals were used to calculate the pH and mineral saturation indices using CHIM-XPT. The computed pH of the solution is 4.34. The total sulfate molality within the brine is 0.0095 M. In experimental conditions of 600 mL of brine, 0.0057 moles of sulfate will be converted into 5.7 mL of sulfuric acid. The modeling shows that an excess of 31% O2 forms, indicating that H2S from SO2 disporportionation is oxidized to sulfate, thus no gaseous H2S will form. Remaining SO2 in the experimental headspace has a predicted mole fraction is 10-46. Additional SO2 gas added to the system produces the reaction to precipitate gypsum. Additional gas reactions precipitate gypsum, anhydrite, calcite, and dolomite.

  5. Exposure assessment of oxidant gases and acidic aerosols

    SciTech Connect

    Lioy, P.J.

    1989-01-01

    Clearly the presence of high ozone and acidic species in North America is primarily dependent upon photochemical air pollution. Evidence shows, however, that high acid exposures may occur in specific types of areas of high sulfur fuel use during the winter. At the present time, our concerns about exposure to local populations and regional populations should be directed primarily toward the outdoor activity patterns of individuals in the summer, and how those activity patterns relate to the location, duration, and concentrations of ozone and acid aerosol in photochemical air pollution episodes. Lioy Dyba and Mage et al have examined the activity patterns of children in summer camps. Because they spend more time outside than the normal population, these children form an important group of exercising individuals subject to photochemical pollution exposures. The dose of ozone inhaled by the children in the two camps was within 50% and 25% of the dose inhaled by adults in controlled clinical situations that produced clinically significant decrements in pulmonary function and increased the symptoms after 6.6 hr exposure in a given day. The chamber studies have used only ozone, whereas in the environment this effect may be enhanced by the presence of a complex mixture. The work of Lioy et al in Mendham, New Jersey found that hydrogen ion seemed to play a role in the inability of the children to return immediately to their normal peak expiratory flow rate after exposure. The camp health study conducted in Dunsville, Ontario suggested that children participating in a summer camp where moderate levels of ozone (100 ppb) but high levels of acid (46 micrograms/m3) occurred during an episode had a similar response. Thus, for children or exercising adults who are outdoors for at least one hour or more during a given day, the presence and persistence of oxidants in the environment are of particular concern. 63 references.

  6. Spectroscopic study of the photofixation of SO2 on anatase TiO2 thin films and their oleophobic properties.

    PubMed

    Topalian, Z; Niklasson, G A; Granqvist, C G; Österlund, L

    2012-02-01

    Photoinduced SO(2) fixation on anatase TiO(2) films was studied by in situ Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). The TiO(2) films were prepared by reactive DC magnetron sputtering and were subsequently exposed to 50 ppm SO(2) gas mixed in synthetic air and irradiated with UV light at substrate temperatures between 298 and 673 K. Simultaneous UV irradiation and SO(2) exposure between 373 and 523 K resulted in significant sulfur (S) deposits on crystalline TiO(2) films as determined by XPS, whereas amorphous films contained negligible amounts of S. At substrate temperatures above 523 K, the S deposits readily desorbed from TiO(2). The oxidation state of sulfur successively changed from S(4+) for SO(2) adsorbed on crystalline TiO(2) films at room temperature without irradiation to S(6+) for films exposed to SO(2) at elevated temperatures with simultaneous irradiation. In situ FTIR was used to monitor the temporal evolution of the photoinduced surface reaction products formed on the TiO(2) surfaces. It is shown that band gap excitation of TiO(2) results in photoinduced oxidation of SO(2), which at elevated temperatures become coordinated to the TiO(2) lattice through interactions with O vacancies and form sulfite and sulfate surface species. These species makes the surface acidic, which is manifested in nondetectable adherence of stearic acid to the modified surface. The modified films show good chemical stability as evidenced by sonication and repeated recycling of the films. The results suggest a new method to functionalize wide band gap oxide surfaces by means of photoinduced reactions in reactive gases at elevated substrate temperatures. In the case of anatase TiO(2) in reactive SO(2) gas, we here show that such functionalization yields surfaces with excellent oleophobic properties, as probed by adhesion of stearic acid. PMID:22204641

  7. Process for removal of ammonia and acid gases from contaminated waters

    DOEpatents

    King, C.J.; Mackenzie, P.D.

    1982-09-03

    Contaminating basic gases, i.e., ammonia and acid gases, e.g., carbon dioxide, are removed from process waters or waste waters in a combined extraction and stripping process. Ammonia in the form of ammonium ion is extracted by an immiscible organic phase comprising a liquid cation exchange component, especially an organic phosphoric acid derivative, and preferably di-2-ethyl hexyl phosphoric acid, dissolved in an alkyl hydrocarbon, aryl hydrocarbon, higher alcohol, oxygenated hydrocarbon, halogenated hydrocarbon, and mixtures thereof. Concurrently, the acidic gaseous contaminants are stripped from the process or waste waters by stripping with stream, air, nitrogen, or the like. The liquid cation exchange component has the ammonia stripped therefrom by heating, and the component may be recycled to extract additional amounts of ammonia.

  8. Process for removal of ammonia and acid gases from contaminated waters

    DOEpatents

    King, C. Judson; MacKenzie, Patricia D.

    1985-01-01

    Contaminating basic gases, i.e., ammonia, and acid gases, e.g., carbon dioxide, are removed from process waters or waste waters in a combined extraction and stripping process. Ammonia in the form of ammonium ion is extracted by an immiscible organic phase comprising a liquid cation exchange component, especially an organic phosphoric acid derivative, and preferably di-2-ethyl hexyl phosphoric acid, dissolved in an alkyl hydrocarbon, aryl hydrocarbon, higher alcohol, oxygenated hydrocarbon, halogenated hydrocarbon, and mixtures thereof. Concurrently, the acidic gaseous contaminants are stripped from the process or waste waters by stripping with steam, air, nitrogen, or the like. The liquid cation exchange component has the ammonia stripped therefrom by heating, and the component may be recycled to extract additional amounts of ammonia.

  9. 40 CFR 60.54a - Standard for municipal waste combustor acid gases.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for municipal waste combustor... for Municipal Waste Combustors for Which Construction is Commenced After December 20, 1989 and on or Before September 20, 1994 § 60.54a Standard for municipal waste combustor acid gases. (a)-(b) (c) On...

  10. 40 CFR 60.54a - Standard for municipal waste combustor acid gases.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for municipal waste combustor... for Municipal Waste Combustors for Which Construction Is Commenced After December 20, 1989 and On or Before September 20, 1994 § 60.54a Standard for municipal waste combustor acid gases. (a)-(b) (c) On...

  11. 40 CFR 60.54a - Standard for municipal waste combustor acid gases.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for municipal waste combustor... for Municipal Waste Combustors for Which Construction is Commenced After December 20, 1989 and on or Before September 20, 1994 § 60.54a Standard for municipal waste combustor acid gases. (a)-(b) (c) On...

  12. 40 CFR 60.54a - Standard for municipal waste combustor acid gases.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for municipal waste combustor... for Municipal Waste Combustors for Which Construction is Commenced After December 20, 1989 and on or Before September 20, 1994 § 60.54a Standard for municipal waste combustor acid gases. (a)-(b) (c) On...

  13. 40 CFR 60.54a - Standard for municipal waste combustor acid gases.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for municipal waste combustor... for Municipal Waste Combustors for Which Construction is Commenced After December 20, 1989 and on or Before September 20, 1994 § 60.54a Standard for municipal waste combustor acid gases. (a)-(b) (c) On...

  14. Model Simulations of the Competing Climatic Effects of SO2 and CO2.

    NASA Astrophysics Data System (ADS)

    Kaufman, Yoram J.; Chou, Ming-Dah

    1993-07-01

    Sulfur dioxide-derived cloud condensation nuclei are expected to enhance the planetary albedo, thereby cooling the planet. This effect might counteract the global warming expected from enhanced greenhouse gases. A detailed treatment of the relationship between fossil fuel burning and the SO2 effect on cloud albedo is implemented in a two-dimensional model for assessing the climate impact. Although there are large gaps in our knowledge of the atmospheric sources and sinks of sulfate aerosol, it is possible to reach some general conclusions. Using a conservative approach, results show that the cooling induced by the SO2 emission can presently counteract 50% of the CO2 greenhouse warming. Since 1980, a strong warming trend has been predicted by the model, 0.15°C, during the 1980-1990 period alone. The model predicts that by the year 2060 the SO2 cooling reduces climate warming by 0.5°C or 25% for the Intergovernmental Panel on Climate Change (IPCC) business as usual (BAU) scenario and 0.2°C or 20% for scenario D (for a slow pace of fossil fuel burning). The hypothesis is examined that the different responses between the Northern Hemisphere (NH) and the Southern Hemisphere (SH) can be used to validate the presence of the SO2-induced cooling. Despite the fact that most of the SO2-induced cooling takes place in the Northern Hemispheric continents, the model-predicted difference in the temperature response between the NH and the SH of 0.2°C in 1980 is expected to remain about the same at least until 2060. This result is a combined effect of the much faster response of the continents than the oceans and of the larger forcing due to CO2 than due to the SO2. The climatic response to a complete filtering of SO2 from the emission products in order to reduce acid rain is also examined. The result is a warming surge of 0.4°C in the first few years after the elimination of the SO2 emission.

  15. 40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... metals, acid gases, organics, and nitrogen oxides. 60.52b Section 60.52b Protection of Environment... § 60.52b Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a... (total mass), corrected to 7 percent oxygen. (d) The limits for nitrogen oxides are specified...

  16. 40 CFR 62.14103 - Emission limits for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... combustor metals, acid gases, organics, and nitrogen oxides. 62.14103 Section 62.14103 Protection of... combustor metals, acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste... nitrogen oxides in excess of the emission limits listed in table 2 of this subpart for affected...

  17. 40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... metals, acid gases, organics, and nitrogen oxides. 60.52b Section 60.52b Protection of Environment... § 60.52b Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a... (total mass), corrected to 7 percent oxygen. (d) The limits for nitrogen oxides are specified...

  18. 40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... combustor metals, acid gases, organics, and nitrogen oxides. 60.33b Section 60.33b Protection of Environment..., acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals... limits for nitrogen oxides at least as protective as the emission limits listed in table 1 of...

  19. 40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... combustor metals, acid gases, organics, and nitrogen oxides. 60.33b Section 60.33b Protection of Environment..., acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals... limits for nitrogen oxides at least as protective as the emission limits listed in table 1 of...

  20. 40 CFR 62.14103 - Emission limits for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... combustor metals, acid gases, organics, and nitrogen oxides. 62.14103 Section 62.14103 Protection of... combustor metals, acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste... nitrogen oxides in excess of the emission limits listed in table 2 of this subpart for affected...

  1. Experimental equilibrium between acid gases and ethanolamine solutions

    SciTech Connect

    Bhairi, A.M.

    1984-01-01

    The general subject area of this study is equilibrium solubility of carbon dioxide and hydrogen sulfide in solutions of some common ethanolamines. The amines studied are most widely used in the area of gas sweetening. They include monoethanolamine, diglycolamine, diethanolamine and methyldiethanolamine. Only limited data are available for some of these amines. The process involved developing simple apparatus and procedure for investigating the equilibrium solubility of carbon dioxide and hydrogen sulfide in aqueous alkanolamine solutions. The procedure uses a single equilibrium cell. No gas chromatograph nor liquid chemical analysis is required. Measurements of the solubility were made in different amine solution concentrations at acid gas partial pressures to 1000 psia and temperatures from 77 to 240{degree}F. The method used was found to be sound as indicated by the consistency and reproducibility of the data.

  2. Satellite SO2 retrievals from ash rich volcanic plumes: Comparison between different correction procedures

    NASA Astrophysics Data System (ADS)

    Corradini, S.; Pugnaghi, S.; Campion, R.; Arvani, B.; Guerrieri, L.; Merucci, L.

    2012-04-01

    Observations of volcanic degassing yield insights into the magmatic processes which control volcanic activity during both quiescent and eruptive phases. SO2 is an important volcanic gas because of its effects on the environment (e.g. acid rain, effects on plants and public health) and also because once it has reached high altitudes it can be transported over long distances, has a great residence time and can be oxidized to form sulphates. The sulphates are capable of reflecting solar radiation and causing surface cooling. For these reasons there is great interest in improving the quality and frequency of volcanic SO2 retrievals. Satellite observations have been used for a long time to monitor globally distributed volcanic activity because they offer a practical and safe source of valuable data. While no satellite sensor has been developed explicitly for volcanic observations, continuous technological improvement has achieved spatial resolutions and acquisition frequencies that allow increasingly detailed volcanological studies at local scales. Monitoring of volcanic SO2 is one of the key facilities offered by satellite remote sensing techniques both in the UV and in the TIR spectral range. During volcanic eruptions ash and gases can be emitted simultaneously. The plume ash particles (from 1 to 10 micron) tend to reduce the top of atmosphere radiance in the entire Thermal InfraRed spectral range (7-14 micron), including the channels used for the SO2 retrieval. The net effect is a significant SO2 column abundance overestimation. In this work three different ash correction procedures for SO2 volcanic plume retrieval are compared. These procedures, applied to MODIS and ASTER TIR measurements, has been used to retrieve the SO2 emission from the 2010 Eyjafjallajokull (Iceland) and the 2011 Mt. Etna (Italy) eruptions. The first procedure (P1), based on Corradini et al. 2009, needs the simultaneous presence of the 8.7 micron SO2 absorption bands, as well as the split

  3. SO2 EMISSIONS AND TIME SERIES MODELS

    EPA Science Inventory

    The paper describes a time series model that permits the estimation of the statistical properties of pounds of SO2 per million Btu in stack emissions. It uses measured values for this quantity provided by coal sampling and analysis (CSA), by a continuous emissions monitor (CEM), ...

  4. ADVANCED CONCEPTS: SO2 REMOVAL PROCESS IMPROVEMENTS

    EPA Science Inventory

    The report gives results of a study of a potassium scrubbing system that recovers useful forms of sulfur from pollutants while using a low-energy process to regenerate the absorbing medium. The report also describes two versions of a new, regenerable process for SO2 scrubbing tha...

  5. Plasma-chemical waste treatment of acid gases

    SciTech Connect

    Harkness, J.B.L.; Doctor, R.D.; Daniels, E.J.

    1993-09-01

    The research to date has shown that a H{sub 2}S waste-treatment process based on plasma-chemical dissociation technology is compatible with refinery and high-carbon-oxide acid-gas streams. The minor amounts of impurities produced in the plasma-chemical reactor should be treatable by an internal catalytic reduction step. Furthermore, the plasma-chemical technology appears to be more efficient and more economical than the current technology. The principal key to achieving high conversions with relatively low energies of dissociation is the concept of the high-velocity, cyclonic-flow pattern in the plasma reaction zone coupled with the recycling of unconverted hydrogen sulfide. Future work will include testing the effects of components that might be carried over to the plasma reactor by ``upset`` conditions in the amine purification system of a plant and testing the plasma-chemical process on other industrial wastes streams that contain potentially valuable chemical reagents. The strategy for the commercialization of this technology is to form a Cooperative Research and Development Agreement with the Institute of Hydrogen Energy and Plasma Technology of the Russian Scientific Center/Kurchatov Institute and with an American start-up company to develop an ``American`` version of the process and to build a commercial-scale demonstration unit in the United States. The timetable proposed would involve building a ``field test`` facility which would test the plasma-chemical reactor and sulfur recovery unit operations on an industrial hydrogen sulfide waste s at a scale large enough to obtain the energy and material balance data required for a final analysis of the commercial potential of this technology. The field test would then be followed by construction of a commercial demonstration unit in two to three years. The commercial demonstration unit would be a fully integrated plant consisting of one commercial-scale module.

  6. SO2 and SO in circumstellar envelopes

    NASA Astrophysics Data System (ADS)

    Guilloteau, S.; Lucas, R.; Omont, A.; Nguyen-Q-Rieu

    1986-09-01

    After its first detection in circumstellar envelopes (Lucas et al. 1986) SO2 has been systematically searched for with the IRAM 30-m telescope. It has been found in 3 new stars, with very strong lines in OH 231.8+4.2 (TA* ≈ 0.7 - 1.4K, Trot ≈ 25K, Δv ≈ 80 km s-1, TA*(SO2) > TA*(CO) ) and relatively strong ones in OH 26.5+0.6. SO has been detected for the first time in a circumstellar shell, in OH 231.8+4.2. H13CN has been observed in the same star, suggesting a very large abundance of 13C.

  7. Morphological and chemical modification of mineral dust: Observational insight into the heterogeneous uptake of acidic gases

    NASA Astrophysics Data System (ADS)

    Matsuki, Atsushi; Iwasaka, Yasunobu; Shi, Guangyu; Zhang, Daizhou; Trochkine, Dmitri; Yamada, Maromu; Kim, Yoon-Suk; Chen, Bin; Nagatani, Tetsuji; Miyazawa, Takeshi; Nagatani, Masahiro; Nakata, Hiroshi

    2005-11-01

    Aerosol samples were collected in the urban atmosphere of Beijing, China, by deploying a tethered balloon. Coarse particles (d > 1 μm) were individually analyzed using electron microscopes, to investigate the extent of dust modification by acidic gases in the atmosphere. Based on the elemental composition, irregularly shaped mineral dust was separated into carbonate and silicate groups. Both sulfate and nitrate were found to accumulate on carbonate more readily than silicate particles. Interestingly, spherical particles resembling Ca-carbonate in composition were spotted frequently in the samples. These Ca-rich spherical particles were more abundant under humid conditions, suggesting that they are deliquesced carbonate particles that formed in the atmosphere following the uptake of acidic gases. Sulfate and nitrate were more frequently detected in the Ca-rich spherical particles than in carbonate in the original solid form, indicating that the gas uptake efficiency of carbonate is further enhanced after the phase transition.

  8. Soluble species in the Arctic summer troposphere - Acidic gases, aerosols, and precipitation

    NASA Technical Reports Server (NTRS)

    Talbot, R. W.; Vijgen, A. S.; Harriss, R. C.

    1992-01-01

    The large-scale spatial distribution from 0.15-to 6 km altitude in the North American Arctic troposphere of several soluble acidic gases and major aerosol species during the summertime is reported. The distribution is found to be compositionally consistent on a large spatial scale. The summertime troposphere is an acidic environment, with HCOOH and CH3COOH the principal acidic gases while acidic sulfate aerosols dominate the particulate phase. There appears to be a surface source of NH3 over the pack ice which may originate from decay of dead marine organisms on the ice surface, evolution from surface ocean waters in open ice leads, or release from rotting sea ice. At low altitude over the pack ice this NH34 appears to partially neutralize aerosol acidity. Over sub-Arctic tundra in southeastern Alaska, inputs of marine biogenic sulfur from the Bering Sea appear to be an important source of boundary layer aerosol SO4(2-). The rainwater acidity over the tundra is typical of remote regions.

  9. Mineral dust photochemistry induces nucleation events in the presence of SO2

    PubMed Central

    Dupart, Yoan; King, Stephanie M.; Nekat, Bettina; Nowak, Andreas; Wiedensohler, Alfred; Herrmann, Hartmut; David, Gregory; Thomas, Benjamin; Miffre, Alain; Rairoux, Patrick; D’Anna, Barbara; George, Christian

    2012-01-01

    Large quantities of mineral dust particles are frequently ejected into the atmosphere through the action of wind. The surface of dust particles acts as a sink for many gases, such as sulfur dioxide. It is well known that under most conditions, sulfur dioxide reacts on dust particle surfaces, leading to the production of sulfate ions. In this report, for specific atmospheric conditions, we provide evidence for an alternate pathway in which a series of reactions under solar UV light produces first gaseous sulfuric acid as an intermediate product before surface-bound sulfate. Metal oxides present in mineral dust act as atmospheric photocatalysts promoting the formation of gaseous OH radicals, which initiate the conversion of SO2 to H2SO4 in the vicinity of dust particles. Under low dust conditions, this process may lead to nucleation events in the atmosphere. The laboratory findings are supported by recent field observations near Beijing, China, and Lyon, France. PMID:23213230

  10. SO(2, 3) noncommutative gravity model

    NASA Astrophysics Data System (ADS)

    Dimitrijević, M.; Radovanović, V.

    2014-12-01

    In this paper the noncommutative gravity is treated as a gauge theory of the non-commutative SO(2, 3)★ group, while the noncommutativity is canonical. The Seiberg-Witten (SW) map is used to express noncommutative fields in terms of the corresponding commutative fields. The commutative limit of the model is the Einstein-Hilbert action plus the cosmological term and the topological Gauss-Bonnet term. We calculate the second order correction to this model and obtain terms that are zeroth, first, ... and fourth power of the curvature tensor. Finally, we discuss physical consequences of those correction terms in the limit of big cosmological constant.

  11. Adsorptions of SO2, SOF2, and SO2F2 on Pt-modified anatase (1 0 1) surface: Sensing mechanism study

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoxing; Chen, Qinchuan; Hu, Weihua; Zhang, Jinbin

    2015-10-01

    The type and severity of faults occurring in gas-insulated switchgear (GIS) can be assessed by detecting SF6 decomposed gases, which is significant for fault diagnosis and online condition monitoring of GIS. Characteristic decomposition components of SF6 under partial discharge or overheating faults and first-principle density functional theory calculations are adopted to analyze the adsorption of SO2, SOF2, and SO2F2 on Pt-modified anatase (1 0 1) surface and to examine further the sensing mechanism of Pt-modified anatase-based gas sensor used to detect SO2, SOF2, and SO2F2. Results show that SO2F2 molecule more easily decomposes upon adsorption on the active Pt nanoparticle than SOF2 molecule. Meanwhile, SO2 molecule does not decompose. This finding explains the phenomenon in the sensing experiment of Pt-modified TiO2 nanotube array gas sensor, wherein the response of SO2F2 is higher than that of SOF2 at the optimal temperature of the sensor. Moreover, the responses of SO2F2 and SOF2 significantly change at the optimal temperature, whereas the response of SO2 is nearly unchanged.

  12. 40 CFR 96.254 - Compliance with CAIR SO2 emissions limitation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... limitation for the control period as follows: (1) For a CAIR SO2 source subject to an Acid Rain emissions...) remain in the compliance account. (2) For a CAIR SO2 source not subject to an Acid Rain emissions... number of tons of the source's excess emissions minus, if the source is subject to an Acid Rain...

  13. 40 CFR 97.254 - Compliance with CAIR SO2 emissions limitation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... period as follows: (1) For a CAIR SO2 source subject to an Acid Rain emissions limitation, the...) remain in the compliance account. (2) For a CAIR SO2 source not subject to an Acid Rain emissions... number of tons of the source's excess emissions minus, if the source is subject to an Acid Rain...

  14. Raman Scattering Sensor for On-Line Monitoring of Amines and Acid Gases

    SciTech Connect

    Uibel, Rory; Smith, Lee

    2010-05-20

    Sulfur and CO2 removal from hydrocarbon streams and power plant effluents are a major problem. The sulfur is normally in the form of H2S. These two acid gases are scrubbed using aqueous amine solutions that are difficult to control with conventional technology. Process Instruments Inc. developed Raman scattering technology for on-line, real-time monitoring of amine streams to improve their efficiency in scrubbing H2S and CO2 from hydrocarbon streams and power plant effluents. Improved control of amine and acid gas concentrations will allow refineries, natural gas processes and power plants to more efficiently scrub Sulfur and CO2, saving energy, time and financial resources.

  15. 40 CFR 62.14103 - Emission limits for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... discharged into the atmosphere from that affected facility any gases that contain mercury in excess of 0.080 milligrams per dry standard cubic meter or 15 percent of the potential mercury emission concentration (85... combustor metals, acid gases, organics, and nitrogen oxides. 62.14103 Section 62.14103 Protection...

  16. 40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... waste combustor acid gases, expressed as sulfur dioxide and hydrogen chloride, are specified in... include emission limits for hydrogen chloride at least as protective as the emission limits for hydrogen... hydrogen chloride contained in the gases discharged to the atmosphere from a designated facility is...

  17. Historical analysis of SO2 pollution control policies in China.

    PubMed

    Gao, Cailing; Yin, Huaqiang; Ai, Nanshan; Huang, Zhengwen

    2009-03-01

    Coal is not only an important energy source in China but also a major source of air pollution. Because of this, China's national sulfur dioxide (SO(2)) emissions have been the highest in the world for many years, and since the 1990s, the territory of China's south and southwest has become the third largest acid-rain-prone region in the world. In order to control SO(2) emissions, the Chinese government has formulated and promulgated a series of policies and regulations, but it faces great difficulties in putting them into practice. In this retrospective look at the history of SO(2) control in China, we found that Chinese SO(2) control policies have become increasingly strict and rigid. We also found that the environmental policies and regulations are more effective when central officials consistently give environmental protection top priority. Achieving China's environmental goals, however, has been made difficult by China's economic growth. Part of this is due to the practice of environmental protection appearing in the form of an ideological "campaign" or "storm" that lacks effective economic measures. More recently, better enforcement of environmental laws and regulations has been achieved by adding environmental quality to the performance assessment metrics for leaders at all levels. To continue making advances, China needs to reinforce the economic and environmental assessments for pollution control projects and work harder to integrate economic measures into environmental protection. Nonetheless, China has a long way to go before economic growth and environmental protection are balanced. PMID:19159968

  18. Detoxification of Dissolved SO2 (Bisulfite) by Terricolous Mosses

    PubMed Central

    BHARALI, BHAGAWAN; BATES, JEFFREY W.

    2006-01-01

    • Background and Aims The widespread calcifuge moss Pleurozium schreberi is moderately tolerant of SO2, whereas Rhytidiadelphus triquetrus is limited to calcareous soils in regions of the UK that were strongly affected by SO2 pollution in the 20th century. The proposition that tolerance of SO2 by these terricolous mosses depends on metabolic detoxification of dissolved bisulfite was investigated. • Methods The capacities of the two mosses to accelerate loss of bisulfite from aqueous solutions of NaHSO3 were studied using DTNB [5, 5-dithio-(2-nitrobenzoic acid)] to assay bisulfite, and HPLC to assay sulfate in the incubation solutions. Incubations were performed for different durations, in the presence and absence of light, at a range of solution pH values, in the presence of metabolic inhibitors and with altered moss apoplastic Ca2+ and Fe3+ levels. • Key Results Bisulfite disappearance was markedly stimulated in the light and twice as great for R. triquetrus as for P. schreberi. DCMU, an inhibitor of photosynthetic electron chain transport, significantly reduced bisufite loss. • Conclusions Bisulfite (SO2) tolerance in these terricolous mosses involves extracellular oxidation using metabolic (photo-oxidative) energy, passive oxidation by adsorbed Fe3+ (only available to the calcifuge) and probably also internal metabolic detoxification. PMID:16319108

  19. High-throughput technology for novel SO2 oxidation catalysts

    NASA Astrophysics Data System (ADS)

    Loskyll, Jonas; Stoewe, Klaus; Maier, Wilhelm F.

    2011-10-01

    We review the state of the art and explain the need for better SO2 oxidation catalysts for the production of sulfuric acid. A high-throughput technology has been developed for the study of potential catalysts in the oxidation of SO2 to SO3. High-throughput methods are reviewed and the problems encountered with their adaptation to the corrosive conditions of SO2 oxidation are described. We show that while emissivity-corrected infrared thermography (ecIRT) can be used for primary screening, it is prone to errors because of the large variations in the emissivity of the catalyst surface. UV-visible (UV-Vis) spectrometry was selected instead as a reliable analysis method of monitoring the SO2 conversion. Installing plain sugar absorbents at reactor outlets proved valuable for the detection and quantitative removal of SO3 from the product gas before the UV-Vis analysis. We also overview some elements used for prescreening and those remaining after the screening of the first catalyst generations.

  20. Fabry-Perot interferometer-based remote sensing of SO2

    NASA Astrophysics Data System (ADS)

    Kuhn, Jonas; Bobrowski, Nicole; Lübcke, Peter; Pöhler, Denis; Tirpitz, Jan-Lukas; Vogel, Leif; Platt, Ulrich

    2015-04-01

    We studied SO2 degassing from volcanoes and monitored the corresponding SO2 fluxes. Besides the effect on climate and the hazardous effects at a local scale, the absolute magnitude of SO2 fluxes or ratios of SO2 with other volcanic gases can be an indicator for volcanic activity and even help to understand and model processes in the interior of volcanoes. Due to its characteristic absorption structure, high abundance in the volcanic plume and low atmospheric background, SO2 can be easily identified and quantified by remote sensing techniques. DOAS and FTIR became standard techniques for volcanic SO2 measurements. Along with the development of portable devices they offer the advantage of simultaneous measurements of multiple gas species. However, both techniques often need complex data evaluation and observations are usually limited to a single viewing direction. Spatially resolved measurements, which are for instance required to determine gas fluxes, frequently have to be obtained sequentially leading to a relatively low time resolution. A further, today nearly established method to determine SO2 emission fluxes is the "SO2 camera". The SO2 camera has the advantage of a high spatial and temporal resolution, but is very limited in spectral information using only two wavelength channels and thus being less selective. Cross-interferences with volcanic plume aerosol, the ozone background, and other trace gases frequently cause problems in SO2 camera measurements. Here we introduce a novel passive remote sensing method for SO2 measurements in the atmosphere using a Fabry-Perot interferometer (FPI) setup. The transmission profile of this FPI consists of periodic transmission peaks that match the periodic SO2 absorption bands in the UV. In principle, this method allows imaging of two-dimensional SO2 distributions similarly to SO2 cameras. Interferences of standard SO2 cameras are greatly reduced with the FPI method. In addition, this technique can also be applied to other

  1. Biological production of acetic acid from waste gases with Clostridium ljungdahlii

    DOEpatents

    Gaddy, James L.

    1998-01-01

    A method and apparatus for converting waste gases from industrial processes such as oil refining, carbon black, coke, ammonia, and methanol production, into useful products. The method includes introducing the waste gases into a bioreactor where they are fermented to various organic acids or alcohols by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified. In an exemplary recovery process, the bioreactor raffinate is passed through an extraction chamber into which one or more non-inhibitory solvents are simultaneously introduced to extract the product. Then, the product is separated from the solvent by distillation. Gas conversion rates can be maximized by use of centrifuges, hollow fiber membranes, or other means of ultrafiltration to return entrained anaerobic bacteria from the bioreactor raffinate to the bioreactor itself, thus insuring the highest possible cell concentration.

  2. Biological production of acetic acid from waste gases with Clostridium ljungdahlii

    DOEpatents

    Gaddy, J.L.

    1998-09-15

    A method and apparatus are disclosed for converting waste gases from industrial processes such as oil refining, carbon black, coke, ammonia, and methanol production, into useful products. The method includes introducing the waste gases into a bioreactor where they are fermented to various organic acids or alcohols by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified. In an exemplary recovery process, the bioreactor raffinate is passed through an extraction chamber into which one or more non-inhibitory solvents are simultaneously introduced to extract the product. Then, the product is separated from the solvent by distillation. Gas conversion rates can be maximized by use of centrifuges, hollow fiber membranes, or other means of ultrafiltration to return entrained anaerobic bacteria from the bioreactor raffinate to the bioreactor itself, thus insuring the highest possible cell concentration. 5 figs.

  3. Improved determination of volcanic SO2 emission rates from SO2 camera images

    NASA Astrophysics Data System (ADS)

    Klein, Angelika; Lübcke, Peter; Bobrowski, Nicole; Platt, Ulrich

    2015-04-01

    SO2 cameras determine the SO2 emissions of volcanoes with a high temporal and spatial resolution. They thus visualize the plume morphology and give information about turbulence and plume dispersion. Moreover, from SO2 camera image series emission rates can be determined with high time resolution (as will be explained below), these data can help to improve our understanding of variations in the degassing regime of volcanoes. The first step to obtain emission rates is to integrate the column amount of SO2 along two different plume cross sections (ideally perpendicular to the direction of plume propagation); combined with wind speed information this allows the determination of SO2 fluxes. A popular method to determine the mean wind speed relies on estimating the time lag of the SO2 signal derived for two cross sections of the plume at different distances downwind of the source. This can be done by searching the maximum cross-correlation coefficient of the two signals. Another, more sophisticated method to obtain the wind speed is to use the optical flow technique to obtain a more detailed wind field in the plume from a series of SO2 camera images. While the cross correlation method only gives the mean wind speed between the two cross sections of the plume, the optical flow technique allows to determine the wind speed and direction for each pixel individually (in other words, a two-dimensional projection of the entire wind field in the plume is obtained). While optical flow algorithms in general give a more detailed information about the wind velocities in the volcanic plume, they may fail to determine wind speeds in homogeneous regions (i.e. regions with no spatial variation in SO2 column densities) of the plume. Usually the wind speed is automatically set to zero in those regions, which leads to an underestimation of the total SO2 emission flux. This behavior was observed more than once on a data set of SO2 camera images taken at Etna, Italy in July, 2014. For those

  4. Satellite Observations of Atmospheric SO2 from Volcanic Eruptions

    NASA Astrophysics Data System (ADS)

    Khokhar, M. F.; Platt, U.; Wagner, T.

    Volcanoes are an important source of various atmospheric trace gases. Volcanic eruptions and their emissions are sporadic and intermittent and often occur in uninhabited regions. Therefore assessing the amount and size of the gaseous and particulate emission from volcanoes is difficult. Satellite remote sensing measurements provide one well suited opportunity to overcome this difficulty. Onboard ERS-2, GOME's moderate spectral resolution enables us to apply the Differential Optical Absorption Spectroscopy (DOAS) algorithm to retrieve SO2 column densities from radiance/irradiance measurements in UV spectral region. Volcanic emissions can cause significant variations of climate on a variety of time scales; just one very large eruption can cause a measurable change in the Earth's climate with a time scale of a few years. Stratospheric aerosols produced by volcanic eruptions can influence stratospheric chemistry both through chemical reactions that take place on the surface of the aerosols and through temperature changes induced by their presence in the stratosphere. In this work we give a comprehensive overview on several volcanoes and the retrieval of SO2 column densities from GOME data for the years 1996 - 2002. The focus is on both eruption and out gassing scenarios from different volcanic eruptions in Italy, Iceland, Congo/ Zaire, Ecuador and Mexico.

  5. High harmonic generation from impulsively aligned SO2

    NASA Astrophysics Data System (ADS)

    Devin, Julien; Wang, Song; Kaldun, Andreas; Bucksbaum, Phil

    2016-05-01

    Previous work in high harmonics generation (HHG) in aligned molecular gases has mainly focused on rotational dynamics in order to determine the contributions of different orbitals to the ionization step. In our experiment, we focus on the shorter timescale of vibrational dynamics. We generate high harmonics from impulsively aligned SO2 molecules in a gas jet and record the emitted attosecond pulse trains in a home-built high resolution vacuum ultra violet (VUV) spectrometer. Using the high temporal resolution of our setup, we are able to map out the effects of vibrational wavepackets with a sub-femtosecond resolution. The target molecule, SO2 gas, is impulsively aligned by a near-infrared laser pulse and has accessible vibrations on the timescale of the short laser pulse used. We present first experimental results for the response to this excitation in high-harmonics. We observe both fast oscillations in the time domain as well as shifts of the VUV photon energy outside of the pulse overlaps. Research supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), Chemical Sciences, Geosciences, and Biosciences Division and by the National Science Foundation Graduate Research Fellowship.

  6. Measurement, analysis, and modeling of gas-to-particle conversion between ammonia, acid gases, and fine particles

    NASA Astrophysics Data System (ADS)

    Baek, Bok-Haeng

    Since 1990, the population of hogs in eastern North Carolina has increased sharply resulting in increased emissions of ammonia. An Annular Denuder System (ADS) was used, which consisted of a cyclone separator, two diffusion denuders coated with sodium carbonate and citric acid, respectively, and a filter pack consisting of Teflon and nylon filters in series. The ADS measured ammonia, acid gases, and fine particles in ambient atmosphere at a commercial hog farm in Eastern North Carolina from April 1998 to March 1999. The sodium carbonate coated denuders yielded average acid gas concentrations of 0.23 mug/m 3 HCl (+/-0.20 mug/m3); 1.10 mug/m 3 HONO (+/-1.17 mug/m3); 1.14 mug/m 3 HNO3 (+/-0.81 mug/m3), and 1.61 mug/m 3 SO2 (+/-1.58 mug/m3). The citric acid coated denuders yielded an average concentration of 17.89 mug/m 3 NH3 (+/-15.03 mug/m3). The filters yielded average fine aerosol (i.e., fine particular matter, Dp ≤ 2.5 mum) concentrations of 1.64 mug/m3 NH4+ (+/-1.26 mug/m3); 0.26 mug/m3 Cl - (+/-0.69 mug/m3); 1.92 mug/m 3 NO3- (+/-1.09 mug/m 3), and 3.18 mug/m3 SO42- (+/-3.12 mug/m3). Using the data collected from the study sites, we evaluated the seasonal variations and the effects of relative humidity on fine particle species. Based on the measurements of ammonia, acid gases, and fine particles, the mean pseudo-first-order rate constant, kS, between NH3 and H2SO4 aerosol is estimated to be 3.70 (+/-2.99) x 10-3 sec-1. The rate constant was found to increase as temperature increases, and decrease with increasing relative humidity. The equilibrium time constant was determined based on the estimated kinetic rate constants and the observed inorganic components of atmospheric aerosols. The average value of equilibrium time constant was determined to be 17.01 (+/-12.19) minutes for ambient equilibrium time between ammonia, nitric acid gas and ammonium nitrate aerosol; and 10.83 (+/-8.97) minutes for ammonia, hydrochloric acid, and ammonium chloride. The aerosol

  7. Modeling the simultaneous transport of two acid gases in tertiary amines with reversible reactions

    SciTech Connect

    Al-Ghawas, H.A.; Sandall, O.C.

    1988-10-01

    The objective of this work is to develop a model for the simultaneous mass transfer of two acid gases in tertiary amines accompanied by reversible chemical reactions. The model has been applied to the industrially important system of simultaneous absorption or desorption of CO/sub 2/ and H/sub 2/S in aqueous methyldiethanolamine (MDEA). In most applications the treated gas must be virtually free of H/sub 2/S; however, it is often not necessary or economical to remove substantial amounts of CO/sub 2/. Hence, selective removal of H/sub 2/S from gas streams such as natural or synthetic gases which contain CO/sub 2/ is desirable. In this research a film theory model describing the simultaneous diffusion and reversible reaction of two gases into reactive liquid has been used to predict the mass transfer enhancement factors of CO/sub 2/ and H/sub 2/S in aqueous MDEA solutions. The resulting unstable two point boundary value problem has been solved numerically for a range of the dimensionless parameters that characterize an important application for this system. In studying the simultaneous transport of CO/sub 2/ and H/sub 2/S, it is found that the reversibility of the reactions, under certain conditions, causes desorption to take place although absorption would be expected on the basis of overall driving forces. This showed that not only enhancement factors larger but also smaller than unity and even negative values are possible.

  8. Noble Gases and Nitrogen Released from a Lunar Soil Pyroxene Separate by Acid Etching

    NASA Astrophysics Data System (ADS)

    Rider, P. E.

    1993-07-01

    We report initial results from a series of experiments designed to measure recently implanted solar wind (SW) ions in lunar soil mineral grains [1]. An acid-etching technique similar to the CSSE method developed at ETH Zurich was used to make abundance and isotope measurements of the SW noble gas and nitrogen compositions. Among the samples examined was a pyroxene separate from soil 75081. It was first washed with H2O to remove contamination from the sample finger walls and grain surfaces. H2O also acted as a weak acid, releasing gases from near-surface sites. Treatment with H2SO3 followed the water washes. Acid pH (~1.8 to ~1.0) and temperature (~23 degrees C to ~90 degrees C) and duration of acid attack (several minutes to several days) were varied from step to step. Finally, the sample was pyrolyzed in several steps to remove the remaining gases, culminating with a high-temperature pyrolysis at 1200 degrees C. Measurements of the light noble gases were mostly consistent with those from previous CSSE experiments performed on pyroxene [2,3]. It should be noted, however, that the Zurich SEP component was not easily distinguishable in the steps where it was expected to be observed. We suspect our experimental protocol masked the SEP reservoir, preventing us from seeing its distinctive signature. The most interesting results from this sample are its Kr and Xe isotopic and elemental compositions. Pyroxene apparently retains heavy noble gases as well as ilmenite (and plagioclase [4]). The heavy noble gas element ratios from this sample along with those previously reported [5,6] are, however, considerably heavier than the theoretically determined "solar system" values [7,8]. Explanations for the difference include the possibility that the derivations are incorrect, that there is another component of lunar origin mixing with the solar component, or that some type of loss mechanism is altering the noble gas reservoirs of the grains. The Kr and Xe isotopic compositions for

  9. Market Opportunities for Austenitic Stainless Steels in SO2 Scrubbers

    NASA Astrophysics Data System (ADS)

    Michels, Harold T.

    1980-10-01

    Recent U.S. federal legislation has created new opportunities for SO2 scrubbers because all coals, even low-sulfur western coals, will probably require scrubbing to remove SO2 from gaseous combustion products. Scrubbing, the chemical absorption of SO2 by vigorous contact with a slurry—usually lime or limestone—creates an aggressive acid-chloride solution. This presents a promising market for pitting-resistant austenitic stainless steels, but there is active competition from rubber and fiberglass-lined carbon steel. Since the latter are favored on a first-cost basis, stainless steels must be justified on a cost/performance or life-cost basis. Nickel-containing austenitic alloys are favored because of superior field fabricability. Ferritic stainless steels have little utility in this application because of limitations in weldability and resulting poor corrosion resistance. Inco corrosion test spools indicate that molybdenum-containing austenitic alloys are needed. The leanest alloys for this application are 316L and 317L. Low-carbon grades of stainless steel are specified to minimize corrosion in the vicinity of welds. More highly alloyed materials may be required in critical areas. At present, 16,000 MW of scrubber capacity is operational and 17,000 MW is under construction. Another 29,000 MW is planned, bringing the total to 62,000 MW. Some 160,000 MW of scrubber capacity is expected to be placed in service over the next 10 years. This could translate into a total potential market of 80,000 tons of alloy plate for new power industry construction in the next decade. Retrofitting of existing power plants plus scrubbers for other applications such as inert gas generators for oil tankers, smelters, municipal incinerators, coke ovens, the pulp and paper industry, sulfuric acid plants, and fluoride control in phosphoric acid plants will add to this large market.

  10. Synergistic effect of Brønsted acid and platinum on purification of automobile exhaust gases.

    PubMed

    Fu, Wei; Li, Xin-Hao; Bao, Hong-Liang; Wang, Kai-Xue; Wei, Xiao; Cai, Yi-Yu; Chen, Jie-Sheng

    2013-01-01

    The catalytic purification of automobile exhaust gases (CO, NOx and hydrocarbons) is one of the most practiced conversion processes used to lower the emissions and to reduce the air pollution. Nevertheless, the good performance of exhaust gas purification catalysts often requires the high consumption of noble metals such as platinum. Here we report that the Brønsted acid sites on the external surface of a microporous silicoaluminophosphate (SAPO) act as a promoter for exhaust gas purification, effectively cutting the loading amount of platinum in the catalyst without sacrifice of performance. It is revealed that in the Pt-loaded SAPO-CHA catalyst, there exists a remarkable synergistic effect between the Brønsted acid sites and the Pt nanoparticles, the former helping to adsorb and activate the hydrocarbon molecules for NO reduction during the catalytic process. The thermal stability of SAPO-CHA also makes the composite catalyst stable and reusable without activity decay. PMID:23907148

  11. Synergistic effect of Brønsted acid and platinum on purification of automobile exhaust gases

    NASA Astrophysics Data System (ADS)

    Fu, Wei; Li, Xin-Hao; Bao, Hong-Liang; Wang, Kai-Xue; Wei, Xiao; Cai, Yi-Yu; Chen, Jie-Sheng

    2013-08-01

    The catalytic purification of automobile exhaust gases (CO, NOx and hydrocarbons) is one of the most practiced conversion processes used to lower the emissions and to reduce the air pollution. Nevertheless, the good performance of exhaust gas purification catalysts often requires the high consumption of noble metals such as platinum. Here we report that the Brønsted acid sites on the external surface of a microporous silicoaluminophosphate (SAPO) act as a promoter for exhaust gas purification, effectively cutting the loading amount of platinum in the catalyst without sacrifice of performance. It is revealed that in the Pt-loaded SAPO-CHA catalyst, there exists a remarkable synergistic effect between the Brønsted acid sites and the Pt nanoparticles, the former helping to adsorb and activate the hydrocarbon molecules for NO reduction during the catalytic process. The thermal stability of SAPO-CHA also makes the composite catalyst stable and reusable without activity decay.

  12. Synergistic effect of Brønsted acid and platinum on purification of automobile exhaust gases

    PubMed Central

    Fu, Wei; Li, Xin-Hao; Bao, Hong-Liang; Wang, Kai-Xue; Wei, Xiao; Cai, Yi-Yu; Chen, Jie-Sheng

    2013-01-01

    The catalytic purification of automobile exhaust gases (CO, NOx and hydrocarbons) is one of the most practiced conversion processes used to lower the emissions and to reduce the air pollution. Nevertheless, the good performance of exhaust gas purification catalysts often requires the high consumption of noble metals such as platinum. Here we report that the Brønsted acid sites on the external surface of a microporous silicoaluminophosphate (SAPO) act as a promoter for exhaust gas purification, effectively cutting the loading amount of platinum in the catalyst without sacrifice of performance. It is revealed that in the Pt-loaded SAPO-CHA catalyst, there exists a remarkable synergistic effect between the Brønsted acid sites and the Pt nanoparticles, the former helping to adsorb and activate the hydrocarbon molecules for NO reduction during the catalytic process. The thermal stability of SAPO-CHA also makes the composite catalyst stable and reusable without activity decay. PMID:23907148

  13. Historical Analysis of SO2 Pollution Control Policies in China

    NASA Astrophysics Data System (ADS)

    Gao, Cailing; Yin, Huaqiang; Ai, Nanshan; Huang, Zhengwen

    2009-03-01

    Coal is not only an important energy source in China but also a major source of air pollution. Because of this, China’s national sulfur dioxide (SO2) emissions have been the highest in the world for many years, and since the 1990s, the territory of China’s south and southwest has become the third largest acid-rain-prone region in the world. In order to control SO2 emissions, the Chinese government has formulated and promulgated a series of policies and regulations, but it faces great difficulties in putting them into practice. In this retrospective look at the history of SO2 control in China, we found that Chinese SO2 control policies have become increasingly strict and rigid. We also found that the environmental policies and regulations are more effective when central officials consistently give environmental protection top priority. Achieving China’s environmental goals, however, has been made difficult by China’s economic growth. Part of this is due to the practice of environmental protection appearing in the form of an ideological “campaign” or “storm” that lacks effective economic measures. More recently, better enforcement of environmental laws and regulations has been achieved by adding environmental quality to the performance assessment metrics for leaders at all levels. To continue making advances, China needs to reinforce the economic and environmental assessments for pollution control projects and work harder to integrate economic measures into environmental protection. Nonetheless, China has a long way to go before economic growth and environmental protection are balanced.

  14. Correlations between stream sulphate and regional SO2 emissions

    USGS Publications Warehouse

    Smith, R.A.; Alexander, R.B.

    1986-01-01

    The relationship between atmospheric SO2 emissions and stream and lake acidification has been difficult to quantify, largely because of the limitations of sulphur deposition measurements. Precipitation sulphate (SO4) records are mostly <5 yr in length and do not account for dry sulphur deposition. Moreover, a variable fraction of wet- and dry-deposited sulphur is retained in soils and vegetation and does not contribute to the acidity of aquatic systems. We have compared annual SO2 emissions for the eastern United States from 1976 to 1980 with stream SO4 measurements from fifteen predominantly undeveloped watersheds. We find that the two forms of sulphur are strongly correlated on a regional basis and that streams in the southeastern United States (SE) receive a smaller fraction (on average, 16%, compared with 24%) of regional sulphur emissions than do streams in the northeastern United States (NE). In addition to providing direct empirical evidence of a relationship between sulphur emissions and aquatic chemistry, these results suggest that there are significant regional differences in the fraction of deposited sulphur retained in basin soils and vegetation.The relationship between atmospheric SO//2 emissions and stream and lake acidification has been difficult to quantify, largely because of the limitations of sulphur deposition measurements. The authors have compared annual SO//2 emissions for the eastern United States from 1967 to 1980 with stream SO//4 measurements from fifteen predominantly undeveloped watersheds. They found that both the wet - and dry-deposited forms of sulphur are strongly correlated on a regional basis and that streams in the southeastern United States receive a smaller fraction (on average, 16%, compared with 24%) of regional sulphur emissions than do streams in the northeastern United States. In addition to providing direct empirical evidence of a relationship between sulphur emissions and aquatic chemistry, these results suggest that

  15. HIGH SO2 REMOVAL EFFICIENCY TESTING

    SciTech Connect

    Gary M. Blythe; James L. Phillips

    1997-10-15

    This final report describes the results of performance tests at six full-scale wet lime- and limestone-reagent flue gas desulfurization (FGD) systems. The objective of these tests was to evaluate the effectiveness of low capital cost sulfur dioxide (SO{sub 2}) removal upgrades for existing FGD systems as an option for complying with the provisions of the Clean Air Act Amendments of 1990. The upgrade options tested at the limestone-reagent systems included the use of organic acid additives (dibasic acid (DBA) and/or sodium formate) as well as increased reagent ratio (higher excess limestone levels in the recirculating slurry solids) and absorber liquid-to-gas ratio. One system also tested operating at higher flue gas velocities to allow the existing FGD system to treat flue gas from an adjacent, unscrubbed unit. Upgrade options for the one lime-based system tested included increased absorber venturi pressure drop and increased sulfite concentration in the recirculating slurry liquor.

  16. High frequency SO2 flux measurements at Semeru volcano, Indonesia, using the SO2 camera

    NASA Astrophysics Data System (ADS)

    Smekens, J.; Burton, M. R.; Clarke, A. B.; Harijoko, A.; Wibowo, H.; Sawyer, G.

    2013-12-01

    SO2 monitoring is a common technique at many volcanic centers. Recently, automated networks of scanning spectrometers have led to great improvement in frequency and accuracy of measurements. Simultaneously a new instrument has been proposed to acquire 2D images of volcanic plumes in the UV spectrum. This imaging technique (hereafter referred to as the SO2 camera) provides additional contextual information, as well as a quantitative way of determining plume velocity from a single remote location, without relying on weather reports. These advantages are to be balanced against a loss of spectroscopic information associated with using band-pass filters that reduce precision in the measurements. We have developed a custom-built acquisition and processing software to be used with the SO2 camera developed by INGV-Pisa for monitoring of Etna and Stromboli, which consists of two Quantum Scientific Imaging CCD cameras equipped with UV filters and a USB2000+ spectrometer. We have tested the instrument at two power plants in Arizona, USA. We were able to successfully measure SO2 fluxes as low as 1-2 tons/day. We also validated our method by comparing the SO2 camera measurements against high-frequency in-situ measurements (1 data point every minute) obtained from chemical sensors within the stacks. We have also used the SO2 camera during a field campaign at Semeru volcano, Indonesia, in May and June of 2013. Semeru is a persistently active explosive volcano, whose latest eruption began in 1967. Its eruptive behavior can be characterized by cyclic dome growth and collapse in the active crater and frequent small magnitude explosions occurring at periods of minutes to hours. We found that the majority of SO2 at Semeru is released during the explosive phases (instantaneous peaks of up to 40 kg/s), with passive emission levels between explosions fluctuating from 0-5 kg/s. After the initial explosive release, emission returns to background levels following an exponential decline over

  17. Interaction of NO2 and SO2 with ZnO [101 ¯] surface using density functional theory

    NASA Astrophysics Data System (ADS)

    Singh, Satvinder; Singh, Janpreet; Singh, Gurinder; Kaura, Aman; Tripathi, S. K.

    2016-05-01

    The interaction of NO2 and SO2 gases with ZnO non-polar surface are theoretically studied using ab initio calculations for gas sensing applications. The information about the adsorption scenarios of NO2 and SO2 gases are studied using DFT-GGA approximation. A stable reduced surface of ZnO is analyzed and the compatibility of theoretical results with experimental references is presented.

  18. SO2-induced stability of Ag-alumina catalysts in the SCR of NO with methane

    SciTech Connect

    She, Xiaoyan; Flytzani-Stephanopoulos, Maria; Wang, Chong M.; Wang, Yong; Peden, Charles HF

    2009-04-29

    We report on a stabilization effect on the structure and activity of Ag/Al2O3 for the selective catalytic reduction (SCR) of NOx with CH4 imparted by the presence of SO2 in the exhaust gasmixture. The reaction is carried out at temperature above 600 8C to keep the surface partially free of sulfates. In SO2-free gases, catalyst deactivation is fast and measurable at these temperatures. Time-resolved TEM analyses of used samples have determined that deactivation is due to sintering of silver from well-dispersed clusters to nanoparticles to micrometer-size particles with time-on-stream at 625 8C. However, sintering of silver was dramatically suppressed by the presence of SO2 in the reaction gas mixture. The structural stabilization by SO2 was accompanied by stable catalyst activity for the NO reduction to N2. The direct oxidation of methane was suppressed, thus the methane selectivity was improved in SO2-laden gas mixtures. In tests with high-content silver alumina with some of the silver present in metallic form, an increase in the SCR activity was found in SO2-containing gas mixtures. This is attributed to redispersion of the silver particles by SO2, an unexpected finding. The catalyst performance was reversible over many cycles of operation at 625 8C with the SO2 switched on and off in the gas mixture.

  19. Monitoring of volcanic SO2 emissions using the GOME-2 instrument

    NASA Astrophysics Data System (ADS)

    Hedelt, Pascal; Valks, Pieter; Loyola, Diego

    2014-05-01

    This contribution focusses on the GOME-2 SO2 column products from the METOP-A and B satellites. The GOME-2 SO2 column product has been developed in the framework of EUMETSAT's Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M-SAF). Satellite-based remote sensing measurements of volcanic SO2 provide critical information for reducing volcanic hazards. Volcanic eruptions may bring ash and gases (e.g. SO2) high up into the atmosphere, where a long-range transport can occur. SO2 is an important indicator for volcanic activity and an excellent tracer for volcanic eruption clouds, especially if ash detection techniques fail. SO2 can affect aviation safety: In the cabin it can cause disease and respiratory symptoms, whereas in its hydrogenated form H2SO4 it is highly corrosive and can cause damage to jet engines as well as pitting of windscreens. We will present results for volcanic events retrieved from GOME-2 solar backscattered measurements in the UV wavelength region around 320nm using the Differential Optical Absorption Spectroscopy (DOAS) method. SO2 columns are generated operationally by DLR with the GOME Data Processor (GDP) version 4.7 and are available in near-real-time, i.e. within two hours after sensing. Using data from both MetOp satellites allows for a daily global coverage. We will furthermore present current improvements to the GOME-2 SO2 column product.

  20. Imaging of SO2 emissions from anthropogenic sources as part of AROMAT campaign

    NASA Astrophysics Data System (ADS)

    Brenot, H. H.; Merlaud, A.; Meier, A.; Ruhtz, T.; Van Roozendael, M.; Stebel, K.; Constantin, D.; Belegante, L.; Dekemper, E.; Theys, N.; Campion, R.; Schuettemeyer, D.

    2015-12-01

    This study presents field campaign measurements of SO2 emissions from pollution source in Romania. Three types of instruments (SO2 camera, whisk and push broom imager) proceeded ground-based and airborne data acquisition as part of the AROMAT ESA project (monitoring of SO2 plume from a large thermoelectric plant). The SO2 camera used is an imaging system composed of two UV cameras (synchronised in space and time) allowing fast acquisitions of intensity. Each camera is equipped with the same lens and a specific narrow band-pass filter (one at the wavelength at which SO2 absorbs and one at an off-band wavelength). The combination of two UV cameras provides a 2D image of the integrated content of SO2. The Small Whisk broom Imager for trace gases monitoriNG (SWING) used in this study and developed at the Belgian Institute for Space Aeronomy (BIRA), is based on a compact ultra-violet visible spectrometer and a scanning mirror. The Airborne imaging instrument for Measurements of Atmospheric Pollution (AirMAP) constructed at the Institute of Environmental Physics of the University of Bremen (IUP), performed SO2 measurements in the UV-visible spectral range. Both whisk and push broom scanner use the DOAS technique, that is based on the relationship between the quantity of light absorbed and the number of SO2 molecules in the light path. SWING and AirMAP instruments provide scans of SO2 column density. Quantification of 2D field contents and fluxes of anthropogenic SO2 emissions from Turceni power station (Romania) are shown. Preparatory results from data acquisition in the harbour of Antwerp (monitoring of SO2 emissions from refinery and chemical industry) are also presented.

  1. Collisions and Reactions of Protic Gases with Surfactant-Coated Sulfuric Acid

    NASA Astrophysics Data System (ADS)

    Park, Seong-Chan; Glass, Samuel; Lawrence, Jennifer; Nathanson, Gilbert

    2004-03-01

    The presence of surfactant molecules on sulfuric acid droplets in the atmosphere may alter the rates of heterogeneous reactions by impeding gas entry. We perform molecular beam experiments with deuterated sulfuric acid solutions (60-68 wt % D_2SO4 at 213 K) with varying concentrations of surfactants including butanol, hexanol, and octanol. We direct a beam of a protic gas HX (X = Cl or Br) at a continuously renewed film of supercooled D_2SO_4/D_2O in vacuum and measure the fraction of thermalized HX that undergo HX→ DX exchange. Our results contradict the notion that surfactants impede gas transport. The presence of surface alcohol does not alter the rate of D_2O evaporation from the liquid surface. Our most striking result is that surface alcohol actually increases the HX→ DX exchange fraction, implying that HX dissociates more readily at the interface when alcohol is present. This enhancement may be caused by the dilution of the acid near the surface by segregated alcohol molecules, which provide additional OH groups for protonation by HX. We are now investigating other surfactants as well as other atmospheric gases.

  2. PROJECT SUMMARY: CONTROLLING SO2 EMISSIONS: A REVIEW OF TECHNOLOGIES (EPA/600/SR-00/093)

    EPA Science Inventory

    Sulfur dioxide (SO2) scrubbers may be used by electricity generating units to meet the requirements of Phase II of the Acid Rain SO2Reduction Program. Additionally, the use of scrubbers can result in reduction of mercury and particulate matter emissions. It is timely,therefore,...

  3. CONTROLLING SO2 EMISSIONS: A REVIEW OF TECHNOLOGIES (EPA/600/R-00/093)

    EPA Science Inventory

    Sulfur dioxide (SO2) scrubbers may be used by electricity generating units to meet the requirements of Phase II of the Acid Rain SO2 Reduction Program.Additionally, the use of scrubbers can result in reduction of mercury and particulate matter emissions. It is timely, therefore...

  4. Mineral dust and NOx promote the conversion of SO2 to sulfate in heavy pollution days

    NASA Astrophysics Data System (ADS)

    He, Hong; Wang, Yuesi; Ma, Qingxin; Ma, Jinzhu; Chu, Biwu; Ji, Dongsheng; Tang, Guiqian; Liu, Chang; Zhang, Hongxing; Hao, Jiming

    2014-02-01

    Haze in China has been increasing in frequency of occurrence as well as the area of the affected region. Here, we report on a new mechanism of haze formation, in which coexistence with NOx can reduce the environmental capacity for SO2, leading to rapid conversion of SO2 to sulfate because NO2 and SO2 have a synergistic effect when they react on the surface of mineral dust. Monitoring data from five severe haze episodes in January of 2013 in the Beijing-Tianjin-Hebei regions agreed very well with the laboratory simulation. The combined air pollution of motor vehicle exhaust and coal-fired flue gases greatly reduced the atmospheric environmental capacity for SO2, and the formation of sulfate was found to be a main reason for the growth of fine particles, which led to the occurrence of haze. These results indicate that the impact of motor vehicle exhaust on the atmospheric environment might be underestimated.

  5. Spatio-Temporal Analyses of CH4 and SO2 over Pakistan

    NASA Astrophysics Data System (ADS)

    Mahmood, Irfan; Imran Shahzad, Muhammad; Farooq Iqbal, Muhammad

    2016-07-01

    SO2 and associated compounds are one of main atmospheric pollutant. Moreover, methane - a potent greenhouse gas can also deteriorate the air quality of the region under certain chemical and meteorological conditions. Role of such gases in regional air quality of Pakistan have not been significantly studied. This study involves the analyses of CH4 and SO2 in terms of spatio-temporal distribution over Pakistan from the period 2004 - 2014 using space borne sensors namely Ozone Monitoring Instrument (OMI) and Advanced Infrared Sounder Instrument (AIRS) respectively. Results show an increase in SO2 concentration attributed to trans-boundary sources. Monthly Methane total column results show an increase in atmospheric concentration of methane for the period 2004-2014. Results of the study are complimented by calculating the back trajectories to identify the transport paths. The study significantly describes the regional description and convection phenomenon for SO2 and CH4.

  6. Mineral dust and NOx promote the conversion of SO2 to sulfate in heavy pollution days

    PubMed Central

    He, Hong; Wang, Yuesi; Ma, Qingxin; Ma, Jinzhu; Chu, Biwu; Ji, Dongsheng; Tang, Guiqian; Liu, Chang; Zhang, Hongxing; Hao, Jiming

    2014-01-01

    Haze in China has been increasing in frequency of occurrence as well as the area of the affected region. Here, we report on a new mechanism of haze formation, in which coexistence with NOx can reduce the environmental capacity for SO2, leading to rapid conversion of SO2 to sulfate because NO2 and SO2 have a synergistic effect when they react on the surface of mineral dust. Monitoring data from five severe haze episodes in January of 2013 in the Beijing-Tianjin-Hebei regions agreed very well with the laboratory simulation. The combined air pollution of motor vehicle exhaust and coal-fired flue gases greatly reduced the atmospheric environmental capacity for SO2, and the formation of sulfate was found to be a main reason for the growth of fine particles, which led to the occurrence of haze. These results indicate that the impact of motor vehicle exhaust on the atmospheric environment might be underestimated. PMID:24566871

  7. High temperature abatement of acid gases from waste incineration. Part II: Comparative life cycle assessment study

    SciTech Connect

    Biganzoli, Laura; Racanella, Gaia; Marras, Roberto; Rigamonti, Lucia

    2015-01-15

    Highlights: • Two scenarios of acid gases removal in WTE plants were compared in an LCA study. • A detailed inventory based on primary data has been reported for the production of the new dolomitic sorbent. • Results show that the comparison between the two scenarios does not show systematic differences. • The potential impacts are reduced only if there is an increase in the energy efficiency of the WTE plant. - Abstract: The performances of a new dolomitic sorbent, named Depurcal®MG, to be directly injected at high temperature in the combustion chamber of Waste-To-Energy (WTE) plants as a preliminary stage of deacidification, were experimentally tested during full-scale commercial operation. Results of the experimentations were promising, and have been extensively described in Biganzoli et al. (2014). This paper reports the Life Cycle Assessment (LCA) study performed to compare the traditional operation of the plants, based on the sole sodium bicarbonate feeding at low temperature, with the new one, where the dolomitic sorbent is injected at high temperature. In the latter the sodium bicarbonate is still used, but at lower rate because of the decreased load of acid gases entering the flue gas treatment line. The major goal of the LCA was to make sure that a burden shifting was not taking place somewhere in the life cycle stages, as it might be the case when a new material is used in substitution of another one. According to the comparative approach, only the processes which differ between the two operational modes were included in the system boundaries. They are the production of the two reactants and the treatment of the corresponding solid residues arising from the neutralisation of acid gases. The additional CO{sub 2} emission at the stack of the WTE plant due to the activation of the sodium bicarbonate was also included in the calculation. Data used in the modelling of the foreground system are primary, derived from the experimental tests described in

  8. High temperature abatement of acid gases from waste incineration. Part II: Comparative life cycle assessment study.

    PubMed

    Biganzoli, Laura; Racanella, Gaia; Marras, Roberto; Rigamonti, Lucia

    2015-01-01

    The performances of a new dolomitic sorbent, named Depurcal®MG, to be directly injected at high temperature in the combustion chamber of Waste-To-Energy (WTE) plants as a preliminary stage of deacidification, were experimentally tested during full-scale commercial operation. Results of the experimentations were promising, and have been extensively described in Biganzoli et al. (2014). This paper reports the Life Cycle Assessment (LCA) study performed to compare the traditional operation of the plants, based on the sole sodium bicarbonate feeding at low temperature, with the new one, where the dolomitic sorbent is injected at high temperature. In the latter the sodium bicarbonate is still used, but at lower rate because of the decreased load of acid gases entering the flue gas treatment line. The major goal of the LCA was to make sure that a burden shifting was not taking place somewhere in the life cycle stages, as it might be the case when a new material is used in substitution of another one. According to the comparative approach, only the processes which differ between the two operational modes were included in the system boundaries. They are the production of the two reactants and the treatment of the corresponding solid residues arising from the neutralisation of acid gases. The additional CO2 emission at the stack of the WTE plant due to the activation of the sodium bicarbonate was also included in the calculation. Data used in the modelling of the foreground system are primary, derived from the experimental tests described in Biganzoli et al. (2014) and from the dolomitic sorbent production plant. The results of the LCA show minor changes in the potential impacts between the two operational modes of the plants. These differences are for 8 impact categories in favour of the new operational mode based on the addition of the dolomitic sorbent, and for 7 impact categories in favour of the traditional operation. A final evaluation was conducted on the potential

  9. Mt. Pinatubo SO2 Column Measurements From Mauna Loa

    NASA Technical Reports Server (NTRS)

    Goldman, A.; Murcray, F. J.; Rinsland, C. P.; Blatherwick, R. D.; David, S. J.; Murcray, F. H.; Murcray, D. G.

    1992-01-01

    Absorption features of the nu(sub 1) band of SO2 have been identified in high resolution infrared solar absorption spectra recorded from Mauna Loa, Hawaii, on July 9 and 12, 1991, shortly after the arrival of the first eruption plume from the Mt. Pinatubo volcano in the Phillipines. A total SO2 vertical column amount of (5.1 +/- 0.5) x 10(exp 16) molecules/sq cm on July 9 has been retrieved based on nonlinear least- squares spectral fittings of 9 selected SO2 absorption features with an updated set of SO2 spectral parameters. A SO2 total column upper limit of 0.9 x 10(esp 16) molecules/sq cm deduced from measurements on September 20-24, 1991, is consistent with the dispersion of the SO2 cloud and the rapid conversion of the SO2 vapor into volcanic aerosol particles.

  10. 40 CFR 96.288 - CAIR SO2 allowance allocations to CAIR SO2 opt-in units.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false CAIR SO2 allowance allocations to CAIR... October 31 of the control period after the control period in which a CAIR SO2 opt-in unit enters the CAIR SO2 Trading Program under § 96.284(g) and October 31 of each year thereafter, the permitting...

  11. 40 CFR 96.288 - CAIR SO2 allowance allocations to CAIR SO2 opt-in units.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false CAIR SO2 allowance allocations to CAIR... October 31 of the control period after the control period in which a CAIR SO2 opt-in unit enters the CAIR SO2 Trading Program under § 96.284(g) and October 31 of each year thereafter, the permitting...

  12. 40 CFR 96.288 - CAIR SO 2 allowance allocations to CAIR SO 2 opt-in units.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false CAIR SO 2 allowance allocations to...) By no later than October 31 of the control period after the control period in which a CAIR SO2 opt-in unit enters the CAIR SO2 Trading Program under § 96.284(g) and October 31 of each year thereafter,...

  13. 40 CFR 96.288 - CAIR SO2 allowance allocations to CAIR SO2 opt-in units.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false CAIR SO2 allowance allocations to CAIR... October 31 of the control period after the control period in which a CAIR SO2 opt-in unit enters the CAIR SO2 Trading Program under § 96.284(g) and October 31 of each year thereafter, the permitting...

  14. SO2 camera measurements at Lastarria volcano and Lascar volcano in Chile

    NASA Astrophysics Data System (ADS)

    Lübcke, Peter; Bobrowski, Nicole; Dinger, Florian; Klein, Angelika; Kuhn, Jonas; Platt, Ulrich

    2015-04-01

    The SO2 camera is a remote-sensing technique that measures volcanic SO2 emissions via the strong SO2 absorption structures in the UV using scattered solar radiation as a light source. The 2D-imagery (usually recorded with a frame rate of up to 1 Hz) allows new insights into degassing processes of volcanoes. Besides the large advantage of high frequency sampling the spatial resolution allows to investigate SO2 emissions from individual fumaroles and not only the total SO2 emission flux of a volcano, which is often dominated by the volcanic plume. Here we present SO2 camera measurements that were made during the CCVG workshop in Chile in November 2014. Measurements were performed at Lastarria volcano, a 5700 m high stratovolcano and Lascar volcano, a 5600 m high stratovolcano both in northern Chile on 21 - 22 November, 2014 and on 26 - 27 November, 2014, respectively. At both volcanoes measurements were conducted from a distance of roughly 6-7 km under close to ideal conditions (low solar zenith angle, a very dry and cloudless atmosphere and an only slightly condensed plume). However, determination of absolute SO2 emission rates proves challenging as part of the volcanic plume hovered close to the ground. The volcanic plume therefore is in front of the mountain in our camera images. An SO2 camera system consisting of a UV sensitive CCD and two UV band-pass filters (centered at 315 nm and 330 nm) was used. The two band-pass filters are installed in a rotating wheel and images are taken with both filter sequentially. The instrument used a CCD with 1024 x 1024 pixels and an imaging area of 13.3 mm x 13.3 mm. In combination with the focal length of 32 mm this results in a field-of-view of 25° x 25°. The calibration of the instrument was performed with help of a DOAS instrument that is co-aligned with the SO2 camera. We will present images and SO2 emission rates from both volcanoes. At Lastarria gases are emitted from three different fumarole fields and we will attempt

  15. New discoveries enabled by OMI SO2 measurements and future missions

    NASA Astrophysics Data System (ADS)

    Krotkov, Nickolay

    2010-05-01

    -sulfur coal in its many coal-fired power plants. Recently, China's government has instituted nationwide measures to control SO2 emissions through the adoption of flue-gas desulfurization technology (FGD) on new power plants; and even greater measures were adopted in the Beijing area in anticipation of the Olympic Games. We demonstrate that the OMI can pick up both SO2 and NO2 emissions from large point sources in northern China, where large increases in both gases were observed from 2005 to 2007, over areas with newly established power plants. The OMI SO2/NO2 ratio generally agrees with the estimated emission factors for coal-fired power plants based on a bottom-up approach. Between 2007 and 2008, OMI detected little change in NO2 but dramatic decline in SO2 over the same areas. While the almost constant NO2 levels between the two years imply steady electricity generation from the power plants, the large reduction in SO2 confirms the effectiveness of the FGD units, which likely became operational between 2007 and 2008. Further development of satellite detection and monitoring of point pollution sources requires better than 10km ground resolution. We show how planned Dutch /ESA TROPOMI and NASA GEOCape missions will advance the art of measuring point source emissions in coming decade.

  16. Radiative forcing of SO2 and NOx: A case study in Beijing

    NASA Astrophysics Data System (ADS)

    Sun, Z. A.; Wang, X. Y.; Zeng, X. N.

    2006-03-01

    A case study was performed in Beijing in 2000 to observe concentrations Of SO2 and NO, in the atmosphere and to evaluate their radiative impact. It was found that the concentrations of these gases are usually high in the morning due to a temperature inversion in the boundary layer. The average concentrations obtained from the observations are much higher than those used in the McClatchey reference atmosphere. The radiative impacts of these gases are calculated using a line-by-line radiative transfer model. The results show that the radiative forcing at the surface due to SO2 is 0.0576 W m(-2) and that due to NOx is 0.0032 W m(-2). These figures are almost compatible with that due to CFC11.

  17. Vertical distribution of volcanic SO2 retrieved from IASI.

    NASA Astrophysics Data System (ADS)

    Carboni, Elisa; Grainger, Roy; Mather, Tamsin; Payle, David; Birch, Charlotte; Dudhia, Anu; Ventress, Lucy; Smith, Andy; Hayer, Caterine

    2014-05-01

    Sulphur dioxide (SO2) is an important atmospheric constituent that plays a rucial role in many atmospheric processes and its effect and lifetime are dependent on the SO2 injection altitude. In the troposphere SO2 production leads to the acidification of rainfall while in the stratosphere it oxidises to form a stratospheric H2SO4 haze that can affect climate for several years. We report applications of IASI high resolution infrared spectra to study volcanic emission of sulphur dioxide (SO2). IASI is a Fourier transform spectrometer that covers the spectral range 645 to 2760 cm-1 (3.62-15.5 um). The IASI field of view consists of four circles of 12 km inside a square of 50 x 50 km, and nominally it can achieve global coverage in 12 hours. From 2013 there were 2 IASI instruments on board both METOP A and B giving up to 4 overpasses a day. The SO2 retrieval algorithm uses measurements from 1000 to 1200 cm-1 and from 1300 to 1410 cm-1 (the 7.3 and 8.7 um SO2 bands) made by IASI on the MetOp satellite. The SO2 retrieval follows the method of Carboni et al. (2012) and retrieves SO2 amount and altitude together with a pixel by pixel comprehensive error budget analysis. It permits the quantification of SO2 amount and estimation of plume altitude, even for small eruptions in the lower troposphere (e.g. Etna lava fountains in 2011 and 2013). We present the SO2 amount described as a function of altitude, and the time evolution of SO2 burden for recent volcanic eruptions. Quantification of the total amount of SO2 over several days allows estimation of daily emission rates, and decay factors.

  18. A Balloon Sounding Technique for Measuring SO2 Plumes

    NASA Technical Reports Server (NTRS)

    Morris, Gary A.; Komhyr, Walter D.; Hirokawa, Jun; Lefer, Barry; Krotkov, Nicholay; Ngan, Fong

    2010-01-01

    This paper reports on the development of a new technique for inexpensive measurements of SO2 profiles using a modified dual-ozonesonde instrument payload. The presence of SO2 interferes with the standard electrochemical cell (ECC) ozonesonde measurement, resulting in -1 molecule of O3 reported for each molecule of SO2 present (provided [O3] > [SO2]). In laboratory tests, an SO2 filter made with Cr03 placed on the inlet side of the sonde removes nearly 100% of the SO2 present for concentrations up to 60 ppbv and remained effective after exposure to 2.8 X 10(exp 16) molecules of SO2 [equivalent to a column approximately 150 DU (1 DU = 2.69 X 10(exp 20) molecules m(exp -2))]. Flying two ECC instruments on the same payload with one filtered and the other unfiltered yields SO2 profiles, inferred by subtraction. Laboratory tests and field experience suggest an SO2 detection limit of approximately 3 pbb with profiles valid from the surface to the ozonopause [i.e., approximately (8-10 km)]. Two example profiles demonstrate the success of this technique for both volcanic and industrial plumes.

  19. Regional climatic effects of atmospheric SO2 on Mars

    NASA Technical Reports Server (NTRS)

    Postawko, S. E.; Fanale, F. P.

    1992-01-01

    The conditions under which the valley networks on Mars may have formed remains controversial. The magnitude of an atmospheric greenhouse effect by an early massive CO2 atmosphere has recently been questioned by Kasting. Recent calculations indicate that if solar luminosity were less than about 86 percent of its current value, formation of CO2 clouds in the Martian atmosphere would depress the atmospheric lapse rate and reduce the magnitude of surface warming. In light of recent revisions of magma generation on Mars during each Martian epoch, and the suggestions by Wanke et al. that the role of liquid SO2 should be more carefully explored, we have recalculated the potential greenhouse warming by atmospheric SO2 on Mars, with an emphasis on more localized effects. In the vicinity of an active eruption, the concentration of atmospheric SO2 will be higher than if it is assumed that the erupted SO2 is instantaneously globally distributed. The local steady-state concentration of SO2 is a function of the rate at which it is released, its atmospheric lifetime, and the rate at which local winds act to disperse the SO2. We have made estimates of eruption rates, length of eruption, and dispersion rates of volcanically released SO2, for a variety of atmospheric conditions and atmospheric lifetimes of SO2 to explore the maximum regional climatic effect of SO2.

  20. SO2 measurements at a high altitude site in the central Himalayas: Role of regional transport

    NASA Astrophysics Data System (ADS)

    Naja, Manish; Mallik, Chinmay; Sarangi, Tapaswini; Sheel, Varun; Lal, Shyam

    2014-12-01

    Continuous measurements of a climatically important acidic gas, SO2, were made over Nainital (29.37°N, 79.45°E; 1958 m amsl), a regionally representative site in the central Himalayas, for the first time during 2009-2011. Unlike many other sites, the SO2 levels over Nainital are higher during pre-monsoon (345 pptv) compared to winter (71 pptv). High values during pre-monsoon are attributed to the transport of air masses from regions viz. Indo-Gangetic Plain (IGP), northern India and north-East Pakistan, which are dotted with numerous industries and power plants, where coal burning occurs. Transport from the polluted regions is evinced from good correlations of SO2 with wind speed, NOy and UV aerosol index during these periods. Daytime elevations in SO2 levels, influenced by 'valley winds' and boundary layer evolution, is a persistent feature at Nainital. SO2 levels are very much lower during monsoon compared to pre-monsoon, due to oxidation losses and wet scavenging. Despite this, SO2/NOy slopes are high (>0.4) both during pre-monsoon and monsoon, indicating impacts of point sources. The SO2 levels during winter are lower as the measurement site is cut off from the plains due to boundary layer dynamics. Further, the SO2 levels during winter nights are the lowest (lesser than 50 pptv) and resemble free tropospheric conditions.

  1. Low to middle tropospheric profiles and biosphere/troposphere fluxes of acidic gases in the summertime Canadian taiga

    NASA Technical Reports Server (NTRS)

    Klemm, O.; Talbot, R. W.; Fitzgerald, D. R.; Klemm, K. I.; Lefer, B. L.

    1994-01-01

    We report features of acidic gases in the troposphere from 9 to 5000 m altitude above ground over the Canadian taiga in the summer of 1990. The measurements were conducted at a 30-m meteorological tower and from the NASA Wallops Electra aircraft as part of the joint U.S.-Canadian Arctic Boundary Layer Expedition (ABLE) 3B Northern Wetland Studies (NOWES). We sampled air for acidic gases using the mist chamber collector coupled with subsequent analysis using ion chromatography. At the tower we collected samples at two heights during a 13-day period, including diurnal studies. Using eddy flux and profile data, we estimated the biosphere/troposphere fluxes of nitric, formic, and acetic acids and sulfur dioxide. For the organic acids, emissions from the taiga in the afternoon hours and deposition during the predawn morning hours were observed. The flux intensities alone were however not high enough to explain the observed changes in mixing ratios. The measured deposition fluxes of nitric acid were high enough to have a significant influence on its mixing ratio in the boundary layer. On three days we measured vertical profiles of nitric, formic, and acetic acids through the lower to midtroposphere. We found that the chemical composition of the troposphere was extremely heterogenous. Pronounced layers of polluted air were readily apparent from our measurements. Local photochemical production and episodic long-range transport of trace components, originating from biomass burning and possibly industrial emissions, appear to have a strong influence on the composition of the troposphere and biosphere/troposphere fluxes of acidic gases at this site.

  2. SO2 ABATEMENT FOR COAL-FIRED BOILERS IN JAPAN

    EPA Science Inventory

    The report is a compilation of information on the current status of SO2 abatement technologies for coal-fired boilers in Japan, where strict ambient air quality standards for SO2 and NOx mandate the use of various air pollution control technologies. It focuses on flue gas desulfu...

  3. ACCURACY OF REMOTELY SENSED SO2 MASS EMISSION RATES

    EPA Science Inventory

    Remote sensing data of single-stack power plant emissions and local wind speed have been analyzed to determined SO2 mass flux for comparison with EPA referenced methods. Four days of SO2 data were gathered from a moving platform by three upward-viewing remote sensors -- two ultra...

  4. 40 CFR 74.22 - Actual SO2 emissions rate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....6 for natural gas For other fuels, the combustion source must specify the SO2 emissions factor. (c... (CONTINUED) SULFUR DIOXIDE OPT-INS Allowance Calculations for Combustion Sources § 74.22 Actual SO2 emissions rate. (a) Data requirements. The designated representative of a combustion source shall submit...

  5. JAPANESE ACTIVITIES IN SO2 AND NOX CONTROL

    EPA Science Inventory

    The paper reviews Japanese activities in SO2 and NOx control. From 1970 to 1985, energy use in Japan increased by 25%, and annual coal consumption rose from virtually nothing to 20 million tons, yet emissions of SO2 declined by 75% and NOx by 40%. While increases in hydroelectric...

  6. AN ADVANCED FLUE GAS MONITOR FOR SO2 - PHASE I

    EPA Science Inventory

    The development of an instrument for continuously monitoring SO2 levels in flue gas is proposed. The SO2 will be detected by means of an electrochemical sensor cell, which operates in a three-electrode potentiostatic mode. The proposed innovation is develop-ment of an advan...

  7. STATUS OF DRY SO2 CONTROL SYSTEMS: FALL 1983

    EPA Science Inventory

    The report, on the status of dry SO2 control for utility and industrial boilers in the U.S., reviews curent and recently completed research, development, and commercial activities. Dry SO2 control systems covered include: (1) spray dryers with a fabric filter or an electrostatic ...

  8. LOW NOX COMBUSTION SYSTEMS WITH SO2 CONTROL USING LIMESTONE

    EPA Science Inventory

    The paper describes EPA work on low NOx combustion systems with SO2 control using limestone. Although SO2 control in low NOx systems for both stoker and pulverized-coal-fired furnaces is under investigation at EPA, most of the current work is with pulverized coal. EPA's Limestone...

  9. Estimating SO2 emissions from a large point source using 10 year OMI SO2 observations: Afsin Elbistan Power Plant

    NASA Astrophysics Data System (ADS)

    Kaynak Tezel, Burcak; Firatli, Ertug

    2016-04-01

    SO2 pollution has still been a problem for parts of Turkey, especially regions with large scale coal power plants. In this study, 10 year Ozone Monitoring Instrument (OMI) SO2 observations are used for estimating SO2 emissions from large point sources in Turkey. We aim to estimate SO2 emissions from coal power plants where no online monitoring is available and improve the emissions given in current emission inventories with these top-down estimates. High-resolution yearly averaged maps are created on a domain over large point sources by oversampling SO2 columns for each grid for the years 2005-2014. This method reduced the noise and resulted in a better signal from large point sources and it was used for coal power plants in U.S and India, previously. The SO2 signal over selected power plants are observed with this method, and the spatiotemporal changes of SO2 signal are analyzed. With the assumption that OMI SO2 observations are correlating with emissions, long-term OMI SO2 observation averages can be used to estimate emission levels of significant point sources. Two-dimensional Gaussian function is used for explaining the relationships between OMI SO2 observations and emissions. Afsin Elbistan Power Plant, which is the largest capacity coal power plant in Turkey, is investigated in detail as a case study. The satellite scans within 50 km of the power plant are selected and averaged over a 2 x 2 km2 gridded domain by smoothing method for 2005-2014. The yearly averages of OMI SO2 are calculated to investigate the magnitude and the impact area of the SO2 emissions of the power plant. A significant increase in OMI SO2 observations over Afsin Elbistan from 2005 to 2009 was observed (over 2 times) possibly due to the capacity increase from 1715 to 2795 MW in 2006. Comparison between the yearly gross electricity production of the plant and OMI SO2 observations indicated consistency until 2009, but OMI SO2 observations indicated a rapid increase while gross electricity

  10. Next-Generation Aura/OMI NO2 and SO2 Products

    NASA Technical Reports Server (NTRS)

    Krotkov, Nickolay; Yang, Kai; Bucsela, Eric; Lamsal, Lok; Celarier, Edward; Swartz, William; Carn, Simon; Bhartia, Pawan; Gleason, James; Pickering, Ken; Dickerson, Russ

    2011-01-01

    The measurement of both SO2 and NO2 gases are recognized as an essential component of atmospheric composition missions. We describe current capabilities and limitations of the operational Aura/OMI NO2 and SO2 data that have been used by a large number of researchers. Analyses of the data and validation studies have brought to light a number of areas in which these products can be expanded and improved. Major improvements for new NASA standard (SP) NO2 product include more accurate tropospheric and stratospheric column amounts, along with much improved error estimates and diagnostics. Our approach uses a monthly NO2 climatology based on the NASA Global Modeling Initiative (GMI) chemistry-transport model and takes advantage of OMI data from cloudy scenes to find clean areas where the contribution from the trap NO2 column is relatively small. We then use a new filtering, interpolation and smoothing techniques for separating the stratospheric and tropospheric components of NO2, minimizing the influence of a priori information. The new algorithm greatly improves the structure of stratospheric features relative to the original SP. For the next-generation OMI SO2 product we plan to implement operationally the offline iterative spectral fitting (ISF) algorithm and re-process the OMI Level-2 SO2 dataset using a priori SO2 and aerosol profiles, clouds, and surface reflectivity appropriate for observation conditions. This will improve the ability to detect and quantify weak tropospheric SO2 loadings. The new algorithm is validated using aircraft in-situ data during field campaigns in China (2005 and 2008) and in Maryland (Frostburg, 2010 and DISCOVER-AQ in July 2011). The height of the SO2 plumes will also be estimated for high SO2 loading cases (e.g., volcanic eruptions). The same SO2 algorithm will be applied to the data from OMPS sensor to be launched on NPP satellite later this year. The next-generation NO2 and SO2 products will provide critical information (e

  11. Acidic gases and nitrate and sulfate particles in the atmosphere in the city of Guadalajara, México.

    PubMed

    Saldarriaga-Noreña, Hugo; Waliszewski, Stefan; Murillo-Tovar, Mario; Hernández-Mena, Leonel; de la Garza-Rodríguez, Iliana; Colunga-Urbina, Edith; Cuevas-Ordaz, Rosalva

    2012-05-01

    Atmospheric concentrations of nitrous acid, nitric acid, nitrate and sulfate particles were obtained in this study from April to June 2008 in the center of the city of Guadalajara, while concentrations of ozone, sulfur dioxide, nitrogen dioxide and meteorological parameters (temperature and relative humidity), were acquired by the Secretaría del Medio Ambiente para el Desarrollo Sustentable del Estado de Jalisco (SEMADES). The results showed that nitric acid (2.7 μg m(-3)) was 2.7 times higher than nitrous acid (1.0 μg m(-3)). The sulfur dioxide (SO(2)) concentration indicated an opposite trend to sulfate (SO(4) (2-)), with the average concentration of SO(2) (6.9 μg m(-3)) higher in almost the entire period of study. The sulfur conversion ratio (Fs, 24.9%) and nitrogen conversion ratio (Fn, 6.2%), were revealed to be similar to that reported in other urban areas during warm seasons. It is also noted that ozone is not the main oxidizer of nitrogen dioxide and sulfur dioxide. This determination was made by taking into account the slightly positively correlation determined for Fn (r(2) = 0.084) and Fs (r(2) = 0.092) with ozone that perhaps suggests there are other oxidizing species such as the radical OH, which are playing an important role in the processes of atmospheric oxidation in this area. PMID:22358115

  12. Formation of secondary aerosols from gasoline vehicle exhaust when mixing with SO2

    NASA Astrophysics Data System (ADS)

    Liu, T.; Wang, X.; Hu, Q.; Deng, W.; Zhang, Y.; Ding, X.; Fu, X.; Bernard, F.; Zhang, Z.; Lü, S.; He, Q.; Bi, X.; Chen, J.; Sun, Y.; Yu, J.; Peng, P.; Sheng, G.; Fu, J.

    2016-01-01

    Sulfur dioxide (SO2) can enhance the formation of secondary aerosols from biogenic volatile organic compounds (VOCs), but its influence on secondary aerosol formation from anthropogenic VOCs, particularly complex mixtures like vehicle exhaust, remains uncertain. Gasoline vehicle exhaust (GVE) and SO2, a typical pollutant from coal burning, are directly co-introduced into a smog chamber, in this study, to investigate the formation of secondary organic aerosols (SOA) and sulfate aerosols through photooxidation. New particle formation was enhanced, while substantial sulfate was formed through the oxidation of SO2 in the presence of high concentration of SO2. Homogenous oxidation by OH radicals contributed a negligible fraction to the conversion of SO2 to sulfate, and instead the oxidation by stabilized Criegee intermediates (sCIs), formed from alkenes in the exhaust reacting with ozone, dominated the conversion of SO2. After 5 h of photochemical aging, GVE's SOA production factor revealed an increase by 60-200 % in the presence of high concentration of SO2. The increase could principally be attributed to acid-catalyzed SOA formation as evidenced by the strong positive linear correlation (R2 = 0.97) between the SOA production factor and in situ particle acidity calculated by the AIM-II model. A high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS) resolved OA's relatively lower oxygen-to-carbon (O : C) (0.44 ± 0.02) and higher hydrogen-to-carbon (H : C) (1.40 ± 0.03) molar ratios for the GVE / SO2 mixture, with a significantly lower estimated average carbon oxidation state (OSc) of -0.51 ± 0.06 than -0.19 ± 0.08 for GVE alone. The relative higher mass loading of OA in the experiments with SO2 might be a significant explanation for the lower SOA oxidation degree.

  13. Formation of secondary aerosols from gasoline vehicle exhausts when mixing with SO2

    NASA Astrophysics Data System (ADS)

    Liu, T.; Wang, X.; Hu, Q.; Deng, W.; Zhang, Y.; Ding, X.; Fu, X.; Bernard, F.; Zhang, Z.; Lü, S.; He, Q.; Bi, X.; Chen, J.; Sun, Y.; Yu, J.; Peng, P.; Sheng, G.; Fu, J.

    2015-09-01

    Sulfur dioxide (SO2) can enhance the formation of secondary aerosols from biogenic volatile organic compounds (VOCs), but its influence on secondary aerosol formation from anthropogenic VOCs, particularly complex mixtures like vehicle exhausts, is still poorly understood. Here we directly co-introduced gasoline vehicles exhausts (GVE) and SO2, a typical pollutant from coal burning, into a smog chamber to investigate the formation of secondary organic aerosols (SOA) and sulfate aerosols through photooxidation. In the presence of high concentration of SO2, new particle formation was enhanced while substantial sulfate was formed through the oxidation of SO2. The homogenous oxidation by OH radicals contributed a negligible fraction to the conversion of SO2 to sulfate, and instead the oxidation by stabilized Criegee intermediates (sCIs), formed from alkenes in the exhaust reacting with ozone, dominated the conversion of SO2. After 5 h of photochemical aging, GVE's SOA production factor revealed an increase by 60-200 % in the presence of high concentration of SO2. This increase could largely be attributed to acid-catalyzed SOA formation, which was evidenced by the strong positive linear correlation (R2 = 0.97) between the SOA production factor and in-situ particle acidity calculated by AIM-II model. A high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS) resolved OA's relatively lower oxygen-to-carbon (O : C) and higher hydrogen-to-carbon (H : C) molar ratios for the GVE/SO2 mixture, with a much lower estimated average carbon oxidation state (OSc) of -0.51 ± 0.06 than that of -0.19 ± 0.08 for GVE alone. The relative higher mass loading of OA in the experiments with SO2 might be the major reason for the lower oxidation degree of SOA.

  14. Multi-decadal satellite measurements of passive and eruptive volcanic SO2 emissions

    NASA Astrophysics Data System (ADS)

    Carn, Simon; Yang, Kai; Krotkov, Nickolay; Prata, Fred; Telling, Jennifer

    2015-04-01

    Periodic injections of sulfur gas species (SO2, H2S) into the stratosphere by volcanic eruptions are among the most important, and yet unpredictable, drivers of natural climate variability. However, passive (lower tropospheric) volcanic degassing is the major component of total volcanic emissions to the atmosphere on a time-averaged basis, but is poorly constrained, impacting estimates of global emissions of other volcanic gases (e.g., CO2). Stratospheric volcanic emissions are very well quantified by satellite remote sensing techniques, and we report ongoing efforts to catalog all significant volcanic SO2 emissions into the stratosphere and troposphere since 1978 using measurements from the ultraviolet (UV) Total Ozone Mapping Spectrometer (TOMS; 1978-2005), Ozone Monitoring Instrument (OMI; 2004 - present) and Ozone Mapping and Profiler Suite (OMPS; 2012 - present) instruments, supplemented by infrared (IR) data from HIRS, MODIS and AIRS. The database, intended for use as a volcanic forcing dataset in climate models, currently includes over 600 eruptions releasing a total of ~100 Tg SO2, with a mean eruption discharge of ~0.2 Tg SO2. Sensitivity to SO2 emissions from smaller eruptions greatly increased following the launch of OMI in 2004, but uncertainties remain on the volcanic flux of other sulfur species other than SO2 (H2S, OCS) due to difficulty of measurement. Although the post-Pinatubo 1991 era is often classified as volcanically quiescent, many smaller eruptions (Volcanic Explosivity Index [VEI] 3-4) since 2000 have injected significant amounts of SO2 into the upper troposphere - lower stratosphere (UTLS), peaking in 2008-2011. We also show how even smaller (VEI 2) tropical eruptions can impact the UTLS and sustain above-background stratospheric aerosol optical depth, thus playing a role in climate forcing on short timescales. To better quantify tropospheric volcanic degassing, we use ~10 years of operational SO2 measurements by OMI to identify the

  15. SO 2 sorption characteristics of air sampling filter media using a new laboratory test

    NASA Astrophysics Data System (ADS)

    Batterman, Stuart; Osak, Igor; Gelman, Charles

    A significant factor in the selection of filter media used for air sampling is the formation of artifacts due to the sorption of sulfur and nitrogen oxides on the filter. These artifacts can erroneously increase measured particulate concentrations. A technique is developed to measure the uptake of SO 2 and other gases and vapors on air sampling filter media. The static chamber technique features in-chamber measurements of SO 2 concentrations using FTIR spectrometry. The filter uptake, partition coefficient, and diffusion coefficient are estimated from the loss of gaseous SO 2 in the chamber. The technique provides rapid and precise results over a wide range of filter characteristics and avoids problems related to the extraction of target analytes from the filter. A total of 12 types of filters are evaluated, including glass fiber, Teflon-coated glass fiber, nylon, quartz fiber, Teflon, Supor, Nylasorb, and acrylic copolymer membranes. Results indicate that Teflon, quartz and acrylic copolymer filters have minimal sorption of SO 2 while quartz fiber, Supor and Nylasorb filters have high to moderate uptake of SO 2.

  16. Partial discharge early-warning through ultraviolet spectroscopic detection of SO2

    NASA Astrophysics Data System (ADS)

    Zhao, Yu; Wang, Xianpei; Dai, Dangdang; Dong, Zhengcheng; Huang, Yunguang

    2014-03-01

    Surveillance of SF6 decomposition products is significant for detection of partial discharge (PD) in gas insulation switchgear (GIS). As a basis in on-site detection and diagnosis, PD early-warning aims to quickly find the abnormalities using a simple and cheap device. In this paper, SO2 is chosen as a feature product and detected through ultraviolet spectroscopy. The derivative method is employed for baseline correction and spectral enhancement. The standard gases of the main decomposition products are qualitatively and quantitatively detected. Then decomposition experiments with different defects are designed to further verify the feasibility. As a stable decomposition product under PD, SO2 is proved to be applicable for PD early-warning in the field. By selecting the appropriate wavelength range, namely 290-310 nm, ultraviolet derivative spectroscopy is sensitive enough to the trace SO2 in the decomposed gas and the interference of other products can be avoided. Fast Fourier transform could be used for feature extraction in qualitative detection. Concentrations of SO2 and other by-products increase with increasing discharge time and could be affected by the discharge energy and PD type. Ultraviolet detection based on SO2 is effective for PD early-warning but the threshold should still be carefully selected in practice.

  17. Simultaneous removal of SO2 and NO by wet scrubbing using aqueous chlorine dioxide solution.

    PubMed

    Jin, Dong-Seop; Deshwal, Bal-Raj; Park, Young-Seong; Lee, Hyung-Keun

    2006-07-31

    The present study attempts to generate chlorine dioxide (ClO(2)) gas continuously by chlorate-chloride process and to utilize it further to clean up SO(2) and NO(x) gases simultaneously from the flue gas in the lab-scale bubbling reactor. Experiments were carried out to examine the effect of various operating parameters like input SO(2) concentration, input NO concentration, pH of the reaction medium, and ClO(2) feeding rate on the SO(2) and NO(x) removal efficiencies at 45 degrees C. Complete oxidation of NO into NO(2) occurred on passing sufficient ClO(2) gas into the scrubbing solution. SO(2) removal efficiency of about 100% and NO(x) removal efficiency of 66-72% were achieved under optimized conditions. NO(x) removal efficiency decreased slightly with increasing pH and NO concentration. Input SO(2) concentration had marginal catalytic effect on NO(2) absorption. No improvement in the NO(x) removal efficiency was observed on passing excess of chlorine dioxide in the scrubbing solution. PMID:16442222

  18. BrO/SO2 molar ratios from scanning DOAS measurements in the NOVAC network

    NASA Astrophysics Data System (ADS)

    Lübcke, P.; Bobrowski, N.; Arellano, S.; Galle, B.; Garzón, G.; Vogel, L.; Platt, U.

    2013-11-01

    The molar ratio of BrO to SO2 is, like other halogen/sulphur ratios, a~possible precursor for dynamic changes in the shallow part of a volcanic system. While the predictive significance of the BrO/SO2 ratio has not been well constrained yet, it has the major advantage that this ratio can be readily measured using the remote-sensing technique Differential Optical Absorption Spectroscopy (DOAS) in the UV. While BrO/SO2 ratios have been measured during several short-term field campaigns this article presents an algorithm that can be used to obtain long-term time series of BrO/SO2 ratios from the scanning DOAS instruments of the Network for Observation of Volcanic and Atmospheric Change (NOVAC) or comparable networks. Parameters of the DOAS retrieval of both trace gases are given and the influence of co-adding spectra on the retrieval error will be investigated. Difficulties in the evaluation of spectroscopic data from monitoring instruments in volcanic environments and possible solutions are discussed. The new algorithm is demonstrated by evaluating data from the NOVAC scanning DOAS systems at Nevado del Ruiz, Colombia encompassing almost four years of measurements between November 2009 and end of June 2013. This dataset shows variations of the BrO/SO2 ratio several weeks prior to the eruption on 30 June 2012.

  19. BrO/SO2 molar ratios from scanning DOAS measurements in the NOVAC network

    NASA Astrophysics Data System (ADS)

    Lübcke, P.; Bobrowski, N.; Arellano, S.; Galle, B.; Garzón, G.; Vogel, L.; Platt, U.

    2014-06-01

    The molar ratio of BrO to SO2 is, like other halogen/sulfur ratios, a possible precursor for dynamic changes in the shallow part of a volcanic system. While the predictive significance of the BrO/SO2 ratio has not been well constrained yet, it has the major advantage that this ratio can be readily measured using the remote-sensing technique differential optical absorption spectroscopy (DOAS) in the UV. While BrO/SO2 ratios have been measured during several short-term field campaigns, this article presents an algorithm that can be used to obtain long-term time series of BrO/SO2 ratios from the scanning DOAS instruments of the Network for Observation of Volcanic and Atmospheric Change (NOVAC) or comparable networks. Parameters of the DOAS retrieval of both trace gases are given. The influence of co-adding spectra on the retrieval error and influences of radiative transfer will be investigated. Difficulties in the evaluation of spectroscopic data from monitoring instruments in volcanic environments and possible solutions are discussed. The new algorithm is demonstrated by evaluating data from the NOVAC scanning DOAS systems at Nevado del Ruiz, Colombia, encompassing almost 4 years of measurements between November 2009 and end of June 2013. This data set shows variations of the BrO/SO2 ratio several weeks prior to the eruption on 30 June 2012.

  20. Surface Hydrophobicity Causes SO2 Tolerance in Lichens

    PubMed Central

    Hauck, Markus; Jürgens, Sascha-René; Brinkmann, Martin; Herminghaus, Stephan

    2008-01-01

    Background and Aims The superhydrophobicity of the thallus surface in one of the most SO2-tolerant lichen species, Lecanora conizaeoides, suggests that surface hydrophobicity could be a general feature of lichen symbioses controlling their tolerance to SO2. The study described here tests this hypothesis. Methods Water droplets of the size of a raindrop were placed on the surface of air-dry thalli in 50 lichen species of known SO2 tolerance and contact angles were measured to quantify hydrophobicity. Key Results The wettability of lichen thalli ranges from strongly hydrophobic to strongly hydrophilic. SO2 tolerance of the studied lichen species increased with increasing hydrophobicity of the thallus surface. Extraction of extracellular lichen secondary metabolites with acetone reduced, but did not abolish the hydrophobicity of lichen thalli. Conclusions Surface hydrophobicity is the main factor controlling SO2 tolerance in lichens. It presumably originally evolved as an adaptation to wet habitats preventing the depression of net photosynthesis due to supersaturation of the thallus with water. Hydrophilicity of lichen thalli is an adaptation to dry or humid, but not directly rain-exposed habitats. The crucial role of surface hydrophobicity in SO2 also explains why many markedly SO2-tolerant species are additionally tolerant to other (chemically unrelated) toxic substances including heavy metals. PMID:18077467

  1. Measurements of SO2 in the Mount St. Helens debris

    NASA Technical Reports Server (NTRS)

    Kerr, J. B.; Evans, F. J.; Mateer, C. L.

    1982-01-01

    Routine measurements of ozone and SO2 are made with the Dobson and Brewer spectrophotometers at the Atmospheric Environment Service in Downsview Ontario. On May 20 and 21, 1980, large values of column SO2 were observed with both spectrophotometers at the time of passage of the Mount St. Helens debris. Enhanced SO2 values were first observed at 1800Z on May 20. The maximum column amount of SO2 measured was 0.06 cm at 2200 Z. On May 21, SO2 values slowly decreased from 0.03 cm at 1100 Z cm to 0.01 cm at 2000Z. Typical SO2 amounts due to pollution at the Downsview site are approximately 0.003 to 0.005 cm. At the same time of maximum SO2 enhancement, both Dobson and Brewer spectrophotometers measured a 0.040 cm decrease of total ozone. It is not clear whether the decrease of total ozone was caused by the volcanic cloud or natural ozone variability. Air mass trajectories indicate that the altitude of the debris cloud, which passed over Downsview at the time, was between 10 km and 12 km.

  2. Influence of O2 and H2O on carbothermal reduction of SO2 by oil-sand fluid coke.

    PubMed

    Feng, Wenguo; Jia, Charles Q

    2005-12-15

    To develop a new process for removing high-concentration SO2 from industrial flue gases, the carbothermal reduction of SO2 by oil-sand fluid coke at 700 degrees C was investigated by varying the inlet concentration of either O2 or H2O. Concentrations of O2 and H2O ranged from 0 to 20% and from 0 to 30%, respectively, in a stream of SO2 (18%) with the balance helium. Addition of O2 and H2O was found to enhance SO2 reduction. The enhancement was attributed to the reducing gases, CO and H2, produced by solid-gas reactions between carbon and O2 or H2O. The effects of O2 and H2O on sulfur yield, however, were bifacial: adding O2 and/or H2O increased the sulfur yield when SO2 conversion was incomplete, otherwise, it decreased the sulfur yield through the formation of sulfides such as H2S. The results of a thermodynamic analysis were in a good agreementwith the experimental results, suggesting that gas-solid reactions were slow enough to allow gas-phase equilibrium. This study indicates that carbon, such as oil-sand fluid coke, can be utilized to remove SO2 in flue gases containing O2/H2O and to convert it to elemental sulfur. PMID:16475356

  3. Supported polytertiary amines: highly efficient and selective SO2 adsorbents.

    PubMed

    Tailor, Ritesh; Abboud, Mohamed; Sayari, Abdelhamid

    2014-01-01

    Tertiary amine containing poly(propyleneimine) second (G2) and third (G3) generation dendrimers as well as polyethyleneimine (PEI) were developed for the selective removal of SO2. N-Alkylation of primary and secondary amines into tertiary amines was confirmed by FTIR and NMR analysis. Such modified polyamines were impregnated on two nanoporous supports, namely, SBA-15PL silica with platelet morphology and ethanol-extracted pore-expanded MCM-41 (PME) composite. In the presence of 0.1% SO2/N2 at 23 °C, the uptake of modified PEI, G2, and G3 supported on SBA-15PL was 2.07, 2.35, and 1.71 mmol/g, respectively; corresponding to SO2/N ratios of 0.22, 0.4, and 0.3. Under the same conditions, the SO2 adsorption capacity of PME-supported modified PEI and G3 was significantly higher, reaching 4.68 and 4.34 mmol/g, corresponding to SO2/N ratios of 0.41 and 0.82, respectively. The working SO2 adsorption capacity decreased with increasing temperature, reflecting the exothermic nature of the process. The adsorption capacity of these materials was enhanced dramatically in the presence of humidity in the gas mixture. FTIR data before SO2 adsorption and after adsorption and regeneration did not indicate any change in the materials. Nonetheless, the SO2 working capacity decreased in consecutive adsorption/regeneration cycles due to evaporation of impregnated polyamines, rather than actual deactivation. FTIR and (13)C and (15)N CP-MAS NMR of fresh and SO2 adsorbed modified G3 on PME confirmed the formation of a complexation adduct. PMID:24437448

  4. Use of sulfate reducing cell suspension bioreactors for the treatment of SO2 rich flue gases.

    PubMed

    Lens, P N L; Gastesi, R; Lettinga, G

    2003-06-01

    This paper describes a novel bioscrubber concept for biological flue gas desulfurization, based on the recycling of a cell suspension of sulfite/sulfate reducing bacteria between a scrubber and a sulfite/sulfate reducing hydrogen fed bioreactor. Hydrogen metabolism in sulfite/sulfate reducing cell suspensions was investigated using batch activity tests and by operating a completely stirred tank reactor (CSTR). The maximum specific hydrogenotrophic sulfite/sulfate reduction rate increased with 10% and 300%, respectively, by crushing granular inoculum sludge and by cultivation of this sludge as cell suspension in a CSTR. Operation of a sulfite fed CSTR (hydraulic retention time 4 days; pH 7.0; sulfite loading rate 0.5-1.5 g SO3(2-) l(-1) d(-1)) with hydrogen as electron donor showed that high (up to 1.6 g l(-1)) H2S concentrations can be obtained within 10 days of operation. H2S inhibition, however, limited the sulfite reducing capacity of the CSTR. Methane production by the cell suspension disappeared within 20 days reactor operation. The outcompetition of methanogens in excess of H2 can be attributed to CO2 limitation and/or to sulfite or sulfide toxicity. The use of cell suspensions opens perspectives for monolith or packed bed reactor configurations, which have a much lower pressure drop compared to air lift reactors, to supply H2 to sulfite/sulfate reducing bioreactors. PMID:12889613

  5. Generating Water-Soluble Noxious Gases: An Overhead Projector Demonstration

    NASA Astrophysics Data System (ADS)

    Solomon, Sally; Oliver-Hoyo, Maria; Hur, Chinhyu

    1998-12-01

    A simple, inexpensive apparatus to generate and collect water-soluble noxious gases as an overhead projector demonstration can be made from two small beakers and a Petri dish. The detection and generation of sulfur dioxide and nitrogen dioxide are described. Sulfur dioxide dissolved in water is detected using an acid-base indicator, decolorizing of anthocyanin, or reduction of permanganate. The SO2 is generated by addition of sulfite or bisulfite to a strong acid or by the addition of concentrated sulfuric acid to sugars. Nitrogen dioxide is generated by mixing copper and nitric acid and detected using an acid-base indicator.

  6. BENCH-SCALE EVALUATION OF CALCIUM SORBENTS FOR ACID GAS EMISSION CONTROL

    EPA Science Inventory

    Calcium sorbents for acid gas emission control were evaluated for effectiveness in removing SO2/HCl and SO2/NO from simulated incinerator and boiler flue gases. All tests were conducted in a bench-scale reactor (fixed-bed) simulating fabric filter conditions in an acid gas remova...

  7. Adsorption of SO2 onto oxidized and heat-treated activated carbon fibers (ACFS)

    USGS Publications Warehouse

    Daley, M.A.; Mangun, C.L.; DeBarr, J.A.; Riha, S.; Lizzio, A.A.; Donnals, G.L.; Economy, J.

    1997-01-01

    A series of activated carbon fibers (ACFs) and heat-treated oxidized ACFs prepared from phenolic fiber precursors have been studied to elucidate the role of pore size, pore surface chemistry and pore volume for the adsorption of SO2 and its catalytic conversion to H2SO4. For untreated ACFs, the initial rate of SO2 adsorption from flue gas was shown to be inversely related to pore size. At longer times, the amount of SO2 adsorbed from flue gas was dependent on both the pore size and pore volume. Oxidation of the ACFs, using an aqueous oxidant, decreased their adsorption capacity for SO2 from flue gas due to a decrease in pore volume and repulsion of the SO2 from acidic surface groups. If these samples were heat-treated to desorb the oxygen containing function groups, the amount of SO2 adsorption increased. This increase in adsorption capacity was directly correlated to the amount of CO2 evolved during heat-treatment of the oxidized ACFs. The amount of SO2 adsorbed for these samples was related to the pore size, pore surface chemistry and pore volume. This analysis is explained in more detail in this paper. ?? 1997 Elsevier Science Ltd. All rights reserved.

  8. Spatially resolved SO2 flux emissions from Mt Etna

    NASA Astrophysics Data System (ADS)

    D'Aleo, R.; Bitetto, M.; Delle Donne, D.; Tamburello, G.; Battaglia, A.; Coltelli, M.; Patanè, D.; Prestifilippo, M.; Sciotto, M.; Aiuppa, A.

    2016-07-01

    We report on a systematic record of SO2 flux emissions from individual vents of Etna volcano (Sicily), which we obtained using a permanent UV camera network. Observations were carried out in summer 2014, a period encompassing two eruptive episodes of the New South East Crater (NSEC) and a fissure-fed eruption in the upper Valle del Bove. We demonstrate that our vent-resolved SO2 flux time series allow capturing shifts in activity from one vent to another and contribute to our understanding of Etna's shallow plumbing system structure. We find that the fissure eruption contributed ~50,000 t of SO2 or ~30% of the SO2 emitted by the volcano during the 5 July to 10 August eruptive interval. Activity from this eruptive vent gradually vanished on 10 August, marking a switch of degassing toward the NSEC. Onset of degassing at the NSEC was a precursory to explosive paroxysmal activity on 11-15 August.

  9. Li/SO2 Cell for Galileo. [process control

    NASA Technical Reports Server (NTRS)

    Blagdon, L. J.; Marcoux, L.

    1981-01-01

    Some information on the special process controls for lithium sulfur dioxide (Li/SO2) batteries is presented with reference to how those controls affected the Galileo probe program and the instrument test vehicle program. The general considerations that go into any application for basically any type of battery system are discussed. Particular emphasis is given to some of the design tradeoffs which resulted because of the addition of the safety characteristics of the Li/SO2 system.

  10. Effect of Plasma Treatment on Multi-Walled Carbon Nanotubes for the Detection of H2S and SO2

    PubMed Central

    Zhang, Xiaoxing; Yang, Bing; Wang, Xiaojing; Luo, Chenchen

    2012-01-01

    H2S and SO2 are important characteristic gases of partial discharge (PD) generated by latent insulated defects in gas insulated switchgear (GIS). The detection of H2S and SO2 is of great significance in the diagnosis and assessment of the operating status of GIS. In this paper, we perform experiments on the gas sensitivity of unmodified multi-walled carbon nanotubes (MWNTs) and those modified by atmospheric pressure dielectric barrier discharge (DBD) air plasma at different times (30, 60 and 120 s) for H2S and SO2, respectively. The results show that the sensitivity and response time of modified MWNTs to H2S are both improved, whereas the opposite effects are observed for SO2. The modified MWNTs have almost zero sensitivity to SO2. Thus, the MWNTs modified by atmospheric pressure DBD air plasma present good selectivity to H2S, and have great potential in H2S detection. PMID:23012548

  11. SO2-rich equatorial basins and epeirogeny of Io

    NASA Technical Reports Server (NTRS)

    Mcewen, Alfred S.

    1991-01-01

    Comparison of Io's large scale topography with an SO2 abundance map shows that SO2 is concentrated in equatorial topographic basins. In these basins, about 30 pct. of the surface is covered by SO2 at all elevations above the mean triaxial figure, and SO2 coverage increases with decreasing elevation to as much as 56 pct. at elevations below -1.5 km. The correlation is not good from long 240 to 360 degs where bright areas are covered by red, Pele type plume fallout, and in the polar regions where the topography is poorly known. The histogram of SO2 abundance binned by elevation appears bimodal, with a secondary concentration of SO2 at high elevations, but it is not certain that this is significant. Additional observations suggest that the basins have relatively little higher frequency topographic relief. The distribution of active plumes and hotspots show no obvious correlation with the topography. However, the Pele type plume all erupted from regions higher than the mean figure, and five of the eight Prometheus type plumes are more energetic and are associated with high temperature hotspots, whereas Prometheus type plumes are long lived and require large volatile reservoirs.

  12. On the absolute calibration of SO2 cameras

    NASA Astrophysics Data System (ADS)

    Lübcke, P.; Bobrowski, N.; Illing, S.; Kern, C.; Alvarez Nieves, J. M.; Vogel, L.; Zielcke, J.; Delgado Granados, H.; Platt, U.

    2013-03-01

    Sulphur dioxide emission rate measurements are an important tool for volcanic monitoring and eruption risk assessment. The SO2 camera technique remotely measures volcanic emissions by analysing the ultraviolet absorption of SO2 in a narrow spectral window between 300 and 320 nm using solar radiation scattered in the atmosphere. The SO2 absorption is selectively detected by mounting band-pass interference filters in front of a two-dimensional, UV-sensitive CCD detector. One important step for correct SO2 emission rate measurements that can be compared with other measurement techniques is a correct calibration. This requires conversion from the measured optical density to the desired SO2 column density (CD). The conversion factor is most commonly determined by inserting quartz cells (cuvettes) with known amounts of SO2 into the light path. Another calibration method uses an additional narrow field-of-view Differential Optical Absorption Spectroscopy system (NFOV-DOAS), which measures the column density simultaneously in a small area of the camera's field-of-view. This procedure combines the very good spatial and temporal resolution of the SO2 camera technique with the more accurate column densities obtainable from DOAS measurements. This work investigates the uncertainty of results gained through the two commonly used, but quite different, calibration methods (DOAS and calibration cells). Measurements with three different instruments, an SO2 camera, a NFOV-DOAS system and an Imaging DOAS (I-DOAS), are presented. We compare the calibration-cell approach with the calibration from the NFOV-DOAS system. The respective results are compared with measurements from an I-DOAS to verify the calibration curve over the spatial extent of the image. The results show that calibration cells, while working fine in some cases, can lead to an overestimation of the SO2 CD by up to 60% compared with CDs from the DOAS measurements. Besides these errors of calibration, radiative transfer

  13. Novel process of simultaneous removal of SO2 and NO2 by sodium humate solution.

    PubMed

    Hu, Guoxin; Sun, Zhiguo; Gao, Hanyang

    2010-09-01

    A novel simultaneous flue gas desulfurization and denitrification (FGDD) process using sodium humate (HA-Na) solution was proposed. This study relates to the SO2/NO2 absorption efficiency and products of simultaneous removing SO2 and NO2 in a bubbling reactor, especially the effect of recycled water on the SO2/NO2 absorption. Under alkaline conditions, the sulfate content in S-containing compound decreases with the increase of NO2 concentration, whereas there is a contrary result under acidic conditions. Whether the absorption liquid is alkaline or acidic, the presence of NO2 improves the SO2 absorption into HA-Na solution, because NO2 may promote the oxidation of sulfite to sulfate. It seems that the presence of SO2 is unfavorable for the NO2 absorption, but the NO2 absorption efficiency can be improved with the cycle number rising due to the increasing amount of sulfite. Although all the ion concentrations of Na+,SO4(2-),SO3(2-), and NO3- have a gradual increase as the cycle number rises, the ion concentrations of SO4(2-) and Na+ are far more than that of the other ions, which results in a slight decrease of the SO2 absorption efficiency. However, the initial pH of HA-Na solution prepared by recycled water decreases from 10 to 8.1 with the cycle number increasing from 1 to 10, whereas the final pH (the pH after absorption reaction is finished) remains almost constant (3.3). The SO2 absorption efficiency is above 98% and the NO2 absorption efficiency may reach above 95% in the optimal condition in this process. The chief byproduct is a compound fertilizer consisting of humic acid (HA), sulfate, and nitrate. PMID:20704283

  14. Special Polymer/Carbon Composite Films for Detecting SO2

    NASA Technical Reports Server (NTRS)

    Homer, Margie; Ryan, Margaret; Yen, Shiao-Pin; Kisor, Adam; Jewell, April; Shevade, Abhijit; Manatt, Kenneth; Taylor, Charles; Blanco, Mario; Goddard, William

    2008-01-01

    A family of polymer/carbon films has been developed for use as sensory films in electronic noses for detecting SO2 gas at concentrations as low as 1 part per million (ppm). Most previously reported SO2 sensors cannot detect SO2 at concentrations below tens of ppm; only a few can detect SO2 at 1 ppm. Most of the sensory materials used in those sensors (especially inorganic ones that include solid oxide electrolytes, metal oxides, and cadmium sulfide) must be used under relatively harsh conditions that include operation and regeneration at temperatures greater than 100 C. In contrast, the present films can be used to detect 1 ppm of SO2 at typical opening temperatures between 28 and 32 C and can be regenerated at temperatures between 36 and 40 C. The basic concept of making sensing films from polymer/carbon composites is not new. The novelty of the present family of polymer/carbon composites lies in formulating the polymer components of these composites specifically to optimize their properties for detecting SO2. First-principles quantum-mechanical calculations of the energies of binding of SO2 molecules to various polymer functionalities are used as a guide for selecting polymers and understanding the role of polymer functionalities in sensing. The polymer used in the polymer-carbon composite is a copolymer of styrene derivative units with vinyl pyridine or substituted vinyl pyridine derivative units. To make a substituted vinyl pyridine for use in synthesizing such a polymer, poly(2-vinyl pyridine) that has been dissolved in methanol is reacted with 3-chloropropylamine that has been dissolved in a solution of methanol. The methanol is then removed to obtain the copolymer. Later, the copolymer can be dissolved in an appropriate solvent with a suspension of carbon black to obtain a mixture that can be cast and then dried to obtain a sensory film.

  15. FORMATION OF 2-METHYL TETROLS AND 2-METHYLGLYCERIC ACID IN SECONDARY ORGANIC AEROSOL FROM LABORATORY IRRADIATED ISOPRENE/NO X/SO 2/AIR MIXTURES AND THEIR DETECTION IN AMBIENT PM 2.5 SAMPLES COLLECTED IN THE EASTERN UNITED STATES

    EPA Science Inventory

    A series of isoprene/NOx/air irradiation experiments, carried out in both the absence and presence of SO2, were conducted to assess whether isoprene contributes to secondary organic aerosol (SOA) formation. In the absence of SO2 , the SOA yield of 0.002 was low. However, in th...

  16. The utilization of catalyst sorbent in scrubbing acid gases from incineration flue gas.

    PubMed

    Wey, Ming-Yen; Lu, Chi-Yuan; Tseng, Hui-Hsin; Fu, Cheng-Hao

    2002-04-01

    Catalyst sorbents based on alumina-supported CuO, CeO2, and CuO-CeO2 were applied to a dry scrubber to clean up the SO2/HCl/NO simultaneously from pilot-scale fluidized-bed incineration flue gas. In the presence of organic compounds, CO and the submicron particles SO2 and HCI removed by the fresh catalyst sorbents and NO reduced to N2 by NH3 under the catalysis of fresh and spent desulfurization/dechloridization (DeSO2/DeHCl) catalyst sorbents (copper compounds, Cu, CuO, and CuSO4) were evaluated in this paper. The fresh and spent catalyst sorbents were characterized by the Brunner-Emmett-Teller method (BET), X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), inductively coupled plasma-mass spectrometry (ICP-MS), and the elemental analyzer (EA). The study showed that the performances of CuO, CeO2, and CuO-CeO2/gamma-Al2O3 were better than that of Ca(OH)2. The removal efficiency of SO2 and HCl was 80-95% in the dry scrubber system. Under NH3/NO = 1, NO could not be reduced to N2 because it was difficult to control the ratio of air/fuel in the flue gas. For estimating the feasibility of regenerating the spent catalyst sorbents, BET and EA analyses were used. They indicated that the pore structures were nearly maintained and a small amount of carbon accumulated on their surface. PMID:12002190

  17. Measurement of SO2 and BrO at Lastarria, Lascar, and Salar de Atacama

    NASA Astrophysics Data System (ADS)

    Dinger, Florian; Osorio, Matias; Gliß, Jonas; Lübcke, Peter; Bobrowski, Nicole; Platt, Ulich; Frins, Erna; Wagner, Thomas

    2015-04-01

    In November 2014 the 12th CCVG (Commission of the Chemistry of Volcanic Gases) gas workshop took place in Northern Chile. Subject of the field trips were Lastarria (25°10' S, 68°30' W) and Lascar (23°22' S, 67°43' W), both stratovolcanoes with a height of 5700 and 5600 a.s.l., respectively. One of the goals was to investigate the SO2 and BrO emissions of these volcanoes by remote-sensing using Multi-AXial Differential Optical Absorption Spectroscopy (MAX-DOAS). The used 'mini MAX-DOAS' instrument measures scattered solar UV radiation recording spectra within a wavelength range of 294-437 nm and with a spectral resolution of 0.9 nm. The instrument took spectra sequentially at various elevation angles scanning the sky from horizon to zenith. The scanning geometry was adapted to each measurement location. At Lastarria volcano we observed SO2 slant column densities (SCDs) in the order of 1018 molecules/cm2 and BrO SCDs up to 5 - 1013 molecules/cm2. At Lascar volcano we observed SO2 SCDs up to 4 - 1017 molecules/cm2 but no significant BrO absorption features (in a preliminary evaluation). We will present SO2 fluxes and upper detection limits of BrO, and present maxima BrO/SO2 ratios of Lastarria and Lascar. Those ratios will be compared to BrO/SO2 ratios of other - previously studied - Andean volcanoes (e.g. Villarica). Furthermore, we measured the SO2 and BrO SCDs above the Salar de Atacama (23°30' S, 68°15' W), a salt pan with an area of 3000 km2. Spectra were taken in a direction where the Salar de Atacama has an extension of about 50 km and no other obvious emission sources were contributing to the SO2 and BrO absorption signals. At the Salar de Atacama we observed SO2 SCDs up to 2 - 1017 molecules/cm2 and BrO SCDs of up to 7 - 1013 molecules/cm2.

  18. On the absolute calibration of SO2 cameras

    NASA Astrophysics Data System (ADS)

    Lübcke, P.; Bobrowski, N.; Illing, S.; Kern, C.; Alvarez Nieves, J. M.; Vogel, L.; Zielcke, J.; Delgado Granados, H.; Platt, U.

    2012-09-01

    Sulphur dioxide emission flux measurements are an important tool for volcanic monitoring and eruption risk assessment. The SO2 camera technique remotely measures volcanic emissions by analysing the ultraviolet absorption of SO2 in a narrow spectral window between 305 nm and 320 nm using solar radiation scattered in the atmosphere. The SO2 absorption is selectively detected by mounting band-pass interference filters in front of a two-dimensional, UV-sensitive CCD detector. While this approach is simple and delivers valuable insights into the two-dimensional SO2 distribution, absolute calibration has proven to be difficult. An accurate calibration of the SO2 camera (i.e., conversion from optical density to SO2 column density, CD) is crucial to obtain correct SO2 CDs and flux measurements that are comparable to other measurement techniques and can be used for volcanological applications. The most common approach for calibrating SO2 camera measurements is based on inserting quartz cells (cuvettes) containing known amounts of SO2 into the light path. It has been found, however, that reflections from the windows of the calibration cell can considerably affect the signal measured by the camera. Another possibility for calibration relies on performing simultaneous measurements in a small area of the camera's field-of-view (FOV) by a narrow-field-of-view Differential Optical Absorption Spectroscopy (NFOV-DOAS) system. This procedure combines the very good spatial and temporal resolution of the SO2 camera technique with the more accurate column densities obtainable from DOAS measurements. This work investigates the uncertainty of results gained through the two commonly used, but quite different calibration methods (DOAS and calibration cells). Measurements with three different instruments, an SO2 camera, a NFOV-DOAS system and an Imaging DOAS (IDOAS), are presented. We compare the calibration-cell approach with the calibration from the NFOV-DOAS system. The respective

  19. SO2 protects the amino nitrogen metabolism of Saccharomyces cerevisiae under thermal stress

    PubMed Central

    Ancín‐Azpilicueta, Carmen; Barriuso‐Esteban, Blanca; Nieto‐Rojo, Rodrigo; Aristizábal‐López, Nerea

    2012-01-01

    Summary Thermal stress conditions during alcoholic fermentation modify yeasts' plasma membrane since they become more hyperfluid, which results in a loss of bilayer integrity. In this study, the influence of elevated temperatures on nitrogen metabolism of a Saccharomyces cerevisiae strain was studied, as well as the effect of different concentrations of SO2 on nitrogen metabolism under thermal stress conditions. The results obtained revealed that amino nitrogen consumption was lower in the fermentation sample subjected to thermal stress than in the control, and differences in amino acid consumption preferences were also detected, especially at the beginning of the fermentation. Under thermal stress conditions, among the three doses of SO2 studied (0, 35, 70 mg l−1 SO2), the highest dose was observed to favour amino acid utilization during the fermentative process, whereas sugar consumption presented higher rates at medium doses. PMID:22452834

  20. Removal of NO sub x from flue gases using the urea acidic process; Kinetics of the chemical reaction of nitrous acid with urea

    SciTech Connect

    Lasalle, A.; Roizard, C.; Midoux, N.; Bourret, P.; Dyens, P.J. )

    1992-03-01

    This paper deals with the removal of nitrogen oxides from flue gases using the acidic urea process. The chemical hydrolysis of nitrous acid, which leads to NO formation, is avoided by nitrous acid reaction with urea. Products of this reaction are gases, e.g. CO{sub 2} and N{sub 2} which can then be directly released into the atmosphere. The aim here is to determine the kinetic parameters of the chemical reaction of nitrous acid with urea. Experiments are performed in a closed stirred reactor. The manometric method (measurement of the pressure versus time curve) leads to the determination of the concentration of HNO{sub 2} and then to the chemical rate versus time. Operating parameters are the concentration of urea (333-3330 mol m{sup {minus}3}), the pH (0.75-1.25), and the temperature (3-40{degrees}C). The experimental results are as follows: the order relative to nitrous acid is 1; the rate constant decreases with pH; the influence of temperature on the rate constant can be expressed by (pH = 1) k = 1.82 {times} 10{sup 8} exp ({minus}(60400/RT)) (SI units).

  1. Model simulations of the competing climatic effects of SO2 and CO2

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram J.; Chou, Ming-Dah

    1993-01-01

    Sulfur dioxide-derived cloud condensation nuclei are expected to enhance the planetary albedo, thereby cooling the planet. This effect might counteract the global warming expected from enhanced greenhouse gases. A detailed treatment of the relationship between fossil fuel burning and the SO2 effect on cloud albedo is implemented in a two-dimensional model for assessing the climate impact. Using a conservative approach, results show that the cooling induced by the SO2 emission can presently counteract 50 percent of the CO2 greenhouse warming. Since 1980, a strong warming trend has been predicted by the model: 0.15 C during the 1980-1990 period alone. The model predicts that by the year 2060 the SO2 cooling reduces climate warming by 0.5 C or 25 percent for the Intergovernmental Panel on Climate Change (IPCC) business as usual (BAU) scenario and 0.2 C or 20 percent for scenario D (for a slow pace of fossil fuel burning). The hypothesis is examined that the different responses between the Northern Hemisphere and the Southern Hemisphere can be used to validate the presence of the SO2-induced cooling.

  2. Simultaneous control of Hg0, SO2, and NOx by novel oxidized calcium-based sorbents.

    PubMed

    Ghorishi, S Behrooz; Singer, Carl F; Jozewicz, Wojciech S; Sedman, Charles B; Srivastava, Ravi K

    2002-03-01

    Efforts to develop multipollutant control strategies have demonstrated that adding certain oxidants to different classes of Ca-based sorbents leads to a significant improvement in elemental Hg vapor (Hg0), SO2, and NOx removal from simulated flue gases. In the study presented here, two classes of Ca-based sorbents (hydrated limes and silicate compounds) were investigated. A number of oxidizing additives at different concentrations were used in the Ca-based sorbent production process. The Hg0, SO2, and NOx capture capacities of these oxidant-enriched sorbents were evaluated and compared to those of a commercially available activated carbon in bench-scale, fixed-bed, and fluid-bed systems. Calcium-based sorbents prepared with two oxidants, designated C and M, exhibited Hg0 sorption capacities (approximately 100 microg/g) comparable to that of the activated carbon; they showed far superior SO2 and NOx sorption capacities. Preliminary cost estimates for the process utilizing these novel sorbents indicate potential for substantial lowering of control costs, as compared with other processes currently used or considered for control of Hg0, SO2, and NOx emissions from coal-fired boilers. The implications of these findings toward development of multipollutant control technologies and planned pilot and field evaluations of more promising multipollutant sorbents are summarily discussed. PMID:11924858

  3. 40 CFR 52.1923 - Best Available Retrofit Requirements (BART) for SO2 and Interstate pollutant transport provisions...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...; and Units 1 and 2 of the Oklahoma Gas and Electric Sooner plant in accordance with 40 CFR 60.8 and 60... gases from other sources. Heat input shall be calculated in accordance with 40 CFR part 75. Owner or... assurance procedures for CEMS found in 40 CFR part 75. Compliance with the emission limits for SO2 shall...

  4. The effect of SO2 on mineral carbonation in batch tests

    SciTech Connect

    Summers, Cathy A.; Dahlin, David C.; Ochs, Thomas L.

    2004-01-01

    CO2 sequestration is a key element of future emission-free fossil-fueled power plants. Other constituents of flue gas must also be captured and rendered innocuous. Contemporary power plants remove SOx from exit gases, but next-generation plants may simultaneously treat CO2, SOx, and other pollutants. Pioneering tests at the U.S. Department of Energy's Albany Research Center investigated the combined treatment of CO2 and SO2 in a mineral-carbonation process. SO2 was removed from the gas stream, and as a small fraction of the total volume of mineralizing gas, it did not inhibit the carbonation reaction. The results indicate that this approach to CO2 sequestration could be used to treat multiple pollutants.

  5. Flux Calculation Using CARIBIC DOAS Aircraft Measurements: SO2 Emission of Norilsk

    NASA Technical Reports Server (NTRS)

    Walter, D.; Heue, K.-P.; Rauthe-Schoech, A.; Brenninkmeijer, C. A. M.; Lamsal, L. N.; Krotkov, N. A.; Platt, U.

    2012-01-01

    Based on a case-study of the nickel smelter in Norilsk (Siberia), the retrieval of trace gas fluxes using airborne remote sensing is discussed. A DOAS system onboard an Airbus 340 detected large amounts of SO2 and NO2 near Norilsk during a regular passenger flight within the CARIBIC project. The remote sensing data were combined with ECMWF wind data to estimate the SO2 output of the Norilsk industrial complex to be around 1 Mt per year, which is in agreement with independent estimates. This value is compared to results using data from satellite remote sensing (GOME, OMI). The validity of the assumptions underlying our estimate is discussed, including the adaptation of this method to other gases and sources like the NO2 emissions of large industries or cities.

  6. HDO and SO2 thermal mapping on Venus

    NASA Astrophysics Data System (ADS)

    Encrenaz, T.; Greathouse, T.; Richter, M.; Lacy, J.; Widemann, T.; Bézard, B.; Fouchet, T.; Atreya, S.

    2013-09-01

    We report on ground-based thermal observations of Venus using the TEXES imaging spectrometer at IRTF (Mauna Kea, Hawaii) in October 2012. Highresolution data were obtained at 7 μm and 19 μm, probing slightly different layers atop and within the cloud, and were compared with the results of our previous campaign (January 2012, [1]). Three main conclusions can be drawn: (1) An isothermal/inversion layer appears at high latitudes in the October data but not in the January data; (2) The spatial distribution of SO2 seems to show variations within a very short timescale, less than an hour; in contrast, the HDO distribution over the Venus disk shows no noticeable spatial nor temporal variation; (3) The SO2 vertical distribution is strongly depleted a few kilometers above the cloudtop. The high variability of SO2 is probably the result of its very short photodissociation lifetime.

  7. Apparatus for purifying arsine, phosphine, ammonia, and inert gases to remove Lewis acid and oxidant impurities therefrom

    DOEpatents

    Tom, Glenn M.; Brown, Duncan W.

    1991-01-08

    An apparatus for purifying a gaseous mixture comprising arsine, phosphine, ammonia, and/or inert gases, to remove Lewis acid and/or oxidant impurities therefrom, comprising a vessel containing a bed of a scavenger, the scavenger including a support having associated therewith an anion which is effective to remove such impurities, such anion being selected from one or more members of the group consisting of: (i) carbanions whose corresponding protonated compounds have a pK.sub.a value of from about 22 to about 36; and (ii) anions formed by reaction of such carbanions with the primary component of the mixture.

  8. Vitamin E protects against lipid peroxidation due to cold-SO2 coexposure in mouse lung.

    PubMed

    Ergonul, Zuhal; Erdem, Ayşen; Balkanci, Zeynep Dicle; Kilinc, Kamer

    2007-02-01

    Exposure to sulfur dioxide (SO2) and cold increases especially in the winter. SO2 or cold exposure destroys the oxidant/antioxidant balance and increases lipid peroxidation. However, the effect of coexistence of both factors has not been studied yet. Therefore, we investigated the effect of SO2 and/or repeated short-term cold exposure on the oxidant-antioxidant status and the possible protective role of vitamin E in the cardiopulmonary tissues of mice. Swiss albino mice of both sexes were assigned to eight groups. Four groups were kept at room temperature, injected either with saline or vitamin E (100 mg/kg) in the presence or absence of SO2 exposure (10 ppm, 1 h/day, 30 days). The remaining four groups received the same protocol but were exposed to cold (4 +/- 1 degrees C, 1 h/days, 30 days) instead of room temperature. On day 30, the lung and heart tissues were removed for biochemical analysis. SO2 and cold coexposure increased lactate level in the lung, and elevated thiobarbituric acid-reactive substance (TBARS) and reduced glutathione levels in both tissues, while vitamin E treatment reversed TBARS increment predominantly in the lung. In conclusion, cold and SO2 coexposure exerts more deleterious effects in the cardiopulmonary tissues, while vitamin E treatment seems to be protective, particularly in the lung. PMID:17169863

  9. SO(2) inhalation induces protein oxidation, DNA-protein crosslinks and apoptosis in rat hippocampus.

    PubMed

    Sang, Nan; Hou, Li; Yun, Yang; Li, Guangke

    2009-03-01

    Previous studies provide evidence for the possible neurotoxicity of SO(2), but little information is available about its mechanisms. In the present study, SO(2) inhalation-induced effects on the protein oxidation, DNA-protein crosslinks and apoptosis in rat hippocampus were studied, by exposing Wistar rats to SO(2) at 14, 28 and 56mg/m(3). The results indicate that the protein carbonyl content, an indicator of protein oxidation, and DNA-protein crosslink coefficient were significantly augmented with concentration-dependent properties. In addition, SO(2) inhalation at all concentrations tested caused the increases of caspase-3 activity and number of TUNEL positive staining neuron and the statistical difference was observed after 28 and 56mg/m(3) exposure, suggesting the occurrence of apoptosis. The results imply that attacking protein, nucleic acids and lipids by free radicals, generated via SO(2) derivatives in vivo, is one of the main mechanisms for SO(2)-induced injuries in central neuronal system. PMID:18722661

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  11. Volcanic SO2 plume forecasts based on UV satellite observations

    NASA Astrophysics Data System (ADS)

    Flemming, J.; Inness, A.

    2012-04-01

    We present how SO2 observations from satellites were used to facilitate forecasts of volcanic sulphur dioxide (SO2) plumes. Volcanic SO2 is often co-located with volcanic ash and can in many cases be considered as a proxy for volcanic ash. Satellite retrievals of SO2 total columns from GOME-2, OMI and SCIAMACHY for the eruptions of Grímsvötn and Eyjafjallajökull in May 2011 and 2010 were inter-compared and used to (i) estimate source strength and injection height and (ii) to provide SO2 initial conditions for forecasts by means of data assimilation. The forecasts were carried out as an activity within the European MACC project (Monitoring of atmospheric composition and climate). MACC builds and runs a near-real-time system for the forecast of global atmospheric composition using the integrated forecast system of ECMWF. Our study found that OMI retrievals had the highest maximum values and that GOME-2 observations provided the most complete spatial coverage. Basic estimates of plume parameters were inferred from the satellite retrievals by finding the best match with an ensemble of plume forecasts injected at different levels. Further, the SO2 retrievals were assimilated with ECMWF's 4D-VAR algorithm to obtain initial conditions for the plume forecasts. These initialized plume forecasts were also used to validate the consistency of the satellite observations for consecutive days. The Grímsvötn plume could mostly be predicted by the initialized forecasts, whereas the forecasts of the Eyjafjallajökull plume benefited more from the source term estimate.

  12. Measuring SO2 ship emissions with an ultraviolet imaging camera

    NASA Astrophysics Data System (ADS)

    Prata, A. J.

    2014-05-01

    Over the last few years fast-sampling ultraviolet (UV) imaging cameras have been developed for use in measuring SO2 emissions from industrial sources (e.g. power plants; typical emission rates ~ 1-10 kg s-1) and natural sources (e.g. volcanoes; typical emission rates ~ 10-100 kg s-1). Generally, measurements have been made from sources rich in SO2 with high concentrations and emission rates. In this work, for the first time, a UV camera has been used to measure the much lower concentrations and emission rates of SO2 (typical emission rates ~ 0.01-0.1 kg s-1) in the plumes from moving and stationary ships. Some innovations and trade-offs have been made so that estimates of the emission rates and path concentrations can be retrieved in real time. Field experiments were conducted at Kongsfjord in Ny Ålesund, Svalbard, where SO2 emissions from cruise ships were made, and at the port of Rotterdam, Netherlands, measuring emissions from more than 10 different container and cargo ships. In all cases SO2 path concentrations could be estimated and emission rates determined by measuring ship plume speeds simultaneously using the camera, or by using surface wind speed data from an independent source. Accuracies were compromised in some cases because of the presence of particulates in some ship emissions and the restriction of single-filter UV imagery, a requirement for fast-sampling (> 10 Hz) from a single camera. Despite the ease of use and ability to determine SO2 emission rates from the UV camera system, the limitation in accuracy and precision suggest that the system may only be used under rather ideal circumstances and that currently the technology needs further development to serve as a method to monitor ship emissions for regulatory purposes. A dual-camera system or a single, dual-filter camera is required in order to properly correct for the effects of particulates in ship plumes.

  13. Orbifold family unification in SO(2N) gauge theory

    SciTech Connect

    Kawamura, Yoshiharu; Miura, Takashi

    2010-04-01

    We study the possibility of family unification on the basis of SO(2N) gauge theory on the five-dimensional space-time, M{sup 4}xS{sup 1}/Z{sub 2}. Several SO(10), SU(4)xSU(2){sub L}xSU(2){sub R}, or SU(5) multiplets come from a single bulk multiplet of SO(2N) after the orbifold breaking. Other multiplets including brane fields are necessary to compose three families of quarks and leptons.

  14. Aura OMI observations of regional SO2 and NO2 pollution changes from 2005 to 2015

    NASA Astrophysics Data System (ADS)

    Krotkov, Nickolay A.; McLinden, Chris A.; Li, Can; Lamsal, Lok N.; Celarier, Edward A.; Marchenko, Sergey V.; Swartz, William H.; Bucsela, Eric J.; Joiner, Joanna; Duncan, Bryan N.; Folkert Boersma, K.; Pepijn Veefkind, J.; Levelt, Pieternel F.; Fioletov, Vitali E.; Dickerson, Russell R.; He, Hao; Lu, Zifeng; Streets, David G.

    2016-04-01

    The Ozone Monitoring Instrument (OMI) onboard NASA's Aura satellite has been providing global observations of the ozone layer and key atmospheric pollutant gases, such as nitrogen dioxide (NO2) and sulfur dioxide (SO2), since October 2004. The data products from the same instrument provide consistent spatial and temporal coverage and permit the study of anthropogenic and natural emissions on local-to-global scales. In this paper, we examine changes in SO2 and NO2 over some of the world's most polluted industrialized regions during the first decade of OMI observations. In terms of regional pollution changes, we see both upward and downward trends, sometimes in opposite directions for NO2 and SO2, for different study areas. The trends are, for the most part, associated with economic and/or technological changes in energy use, as well as regional regulatory policies. Over the eastern US, both NO2 and SO2 levels decreased dramatically from 2005 to 2015, by more than 40 and 80 %, respectively, as a result of both technological improvements and stricter regulations of emissions. OMI confirmed large reductions in SO2 over eastern Europe's largest coal-fired power plants after installation of flue gas desulfurization devices. The North China Plain has the world's most severe SO2 pollution, but a decreasing trend has been observed since 2011, with about a 50 % reduction in 2012-2015, due to an economic slowdown and government efforts to restrain emissions from the power and industrial sectors. In contrast, India's SO2 and NO2 levels from coal power plants and smelters are growing at a fast pace, increasing by more than 100 and 50 %, respectively, from 2005 to 2015. Several SO2 hot spots observed over the Persian Gulf are probably related to oil and gas operations and indicate a possible underestimation of emissions from these sources in bottom-up emission inventories. Overall, OMI observations have proved valuable in documenting rapid changes in air quality over different

  15. Aura OMI Observations of Regional SO2 and NO2 Pollution Changes from 2005 to 2015

    NASA Technical Reports Server (NTRS)

    Krotkov, Nickolay A.; McLinden, Chris A.; Li, Can; Lamsal, Lok N.; Celarier, Edward A.; Marchenko, Sergey V.; Swartz, William H.; Bucsela, Eric J.; Joiner, Joanna; Duncan, Bryan N.; Boersma, K. Folkert; Veefkind, J. Pepijn; Levelt, Pieternel F.; Fioletov, Vitali E.; Dickerson, Russell R.; He, Hao; Lu, Zifeng; Streets, David G.

    2016-01-01

    The Ozone Monitoring Instrument (OMI) onboard NASA's Aura satellite has been providing global observations of the ozone layer and key atmospheric pollutant gases, such as nitrogen dioxide (NO2) and sulfur dioxide (SO2), since October 2004. The data products from the same instrument provide consistent spatial and temporal coverage and permit the study of anthropogenic and natural emissions on local-to-global scales. In this paper, we examine changes in SO2 and NO2 over some of the world's most polluted industrialized regions during the first decade of OMI observations. In terms of regional pollution changes, we see both upward and downward trends, sometimes in opposite directions for NO2 and SO2, for different study areas. The trends are, for the most part, associated with economic and/or technological changes in energy use, as well as regional regulatory policies. Over the eastern US, both NO2 and SO2 levels decreased dramatically from 2005 to 2015, by more than 40 and 80 percent, respectively, as a result of both technological improvements and stricter regulations of emissions. OMI confirmed large reductions in SO2 over eastern Europe's largest coal-fired power plants after installation of flue gas desulfurization devices. The North China Plain has the world's most severe SO2 pollution, but a decreasing trend has been observed since 2011, with about a 50 percent reduction in 2012-2015, due to an economic slowdown and government efforts to restrain emissions from the power and industrial sectors. In contrast, India's SO2 and NO2 levels from coal power plants and smelters are growing at a fast pace, increasing by more than 100 and 50 percent, respectively, from 2005 to 2015. Several SO2 hot spots observed over the Persian Gulf are probably related to oil and gas operations and indicate a possible underestimation of emissions from these sources in bottom-up emission inventories. Overall, OMI observations have proved valuable in documenting rapid changes in air

  16. Aura OMI observations of regional SO2 and NO2 pollution changes from 2005 to 2014

    NASA Astrophysics Data System (ADS)

    Krotkov, N. A.; McLinden, C. A.; Li, C.; Lamsal, L. N.; Celarier, E. A.; Marchenko, S. V.; Swartz, W. H.; Bucsela, E. J.; Joiner, J.; Duncan, B. N.; Boersma, K. F.; Veefkind, J. P.; Levelt, P. F.; Fioletov, V. E.; Dickerson, R. R.; He, H.; Lu, Z.; Streets, D. G.

    2015-10-01

    The Ozone Monitoring Instrument (OMI) onboard NASA's Aura satellite has been providing global observations of the ozone layer and key atmospheric pollutant gases, such as nitrogen dioxide (NO2) and sulfur dioxide (SO2), since October 2004. The data products from the same instrument provide consistent spatial and temporal coverage and permit the study of anthropogenic and natural emissions on local-to-global scales. In this paper we examine changes in SO2 and NO2 over some of the world's most polluted industrialized regions during the first decade of OMI observations. In terms of regional pollution changes, we see both upward and downward trends, sometimes in opposite directions for NO2 and SO2, for the different study areas. The trends are, for the most part, associated with economic and/or technological changes in energy use, as well as regional regulatory policies. Over the eastern US, both NO2 and SO2 levels decreased dramatically from 2005 to 2014, by more than 40 and 80 %, respectively, as a result of both technological improvements and stricter regulations of emissions. OMI confirmed large reductions in SO2 over eastern Europe's largest coal power plants after installation of flue gas desulfurization devices. The North China Plain has the world's most severe SO2 pollution, but a decreasing trend has been observed since 2011, with about a 50 % reduction in 2012-2014, due to an economic slowdown and government efforts to restrain emissions from the power and industrial sectors. In contrast, India's SO2 and NO2 levels from coal power plants and smelters are growing at a fast pace, increasing by more than 100 and 50 %, respectively, from 2005 to 2014. Several SO2 hot spots observed over the Persian Gulf are probably related to oil and gas operations and indicate a possible underestimation of emissions from these sources in bottom-up emission inventories. Overall, OMI observations have proved to be very valuable in documenting rapid changes in air quality over

  17. The role of SO2 in volcanism on Io

    USGS Publications Warehouse

    Smith, B.A.; Shoemaker, E.M.; Kieffer, S.W.; Cook, A.F., II

    1979-01-01

    Io and Earth are the only planetary bodies known to be volcanically active; the energetics of the eruptive plumes on Io have important structural implications and are closely linked with the presence of sulphur and SO 2. ?? 1979 Nature Publishing Group.

  18. DEVELOPMENT OF AN SO2 MONITOR FOR MOBILE SOURCES

    EPA Science Inventory

    An instrument has been designed and built to monitor the concentration of SO2 in the exhaust of mobile sources. A grating assembly disperses the ultraviolet energy from a deuterium-arc source and passes five narrow spectral intervals. Three of the intervals (set A) coincide with ...

  19. Novel retrieval of volcanic SO 2 abundance from ultraviolet spectra

    NASA Astrophysics Data System (ADS)

    Salerno, G. G.; Burton, M. R.; Oppenheimer, C.; Caltabiano, T.; Tsanev, V. I.; Bruno, N.

    2009-03-01

    The recent development of fixed networks of scanning ultraviolet spectrometers for automatic determination of volcanic SO 2 fluxes has created tremendous opportunities for monitoring volcanoes but has brought new challenges in processing (and interpreting) the copious data flow they produce. A particular difficulty in standard implantation of differential optical absorption (DOAS) methods is the requirement for a clear-sky (plume-free) background spectrum. Our experience after four years of measurements with two UV scanner networks on Etna and Stromboli shows that wide plumes are frequently observed, precluding simple selection of clear-sky spectra. We have therefore developed a retrieval approach based on simulation of the background spectrum. We describe the method here and tune it empirically by collecting clear, zenith sky spectra using calibration cells containing known amounts of SO 2. We then test the performance of this optimised retrieval using clear-sky spectra collected with the same calibration cells but for variable scan angles, time of day, and season (through the course of 1 year), finding acceptable results (~ 12% error) for SO 2 column amounts. We further illustrate the analytical approach using spectra recorded at Mt. Etna during its July 2006 eruption. We demonstrate the reliability of the method for tracking volcano dynamics on different time scales, and suggest it is widely suited to automated SO 2-plume monitoring.

  20. BENCH SCALE STUDIES OF LIMESTONE INJECTION FOR SO2 CONTROL

    EPA Science Inventory

    The report gives results of experiments in a boiler simulator furnace, indicating that the parameters of major importance to SO2 capture are thermal environment, calcium/sulfur ratio, and sorbent composition. Thermal environment (local temperature) had a strong effect on the util...

  1. 76 FR 61098 - Guidance for 1-Hour SO2

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-03

    ...Notice is hereby given that the EPA has posted its draft non- binding guidance titled, ``Guidance for 1-Hour SO2 NAAQS SIP Submissions'' on its Web site. The EPA invites public comments on this guidance document during the comment period specified below, and plans to issue an updated version of the guidance after reviewing timely submitted...

  2. CHARACTERIZATION OF ADVANCED SORBENTS FOR DRY SO2 CONTROL

    EPA Science Inventory

    The paper discusses the development of new flyash/lime sorbents for removing SO2 from coal-fired flue gas. Flyash/lime weight ratios of 1:1 to 10:1 and several additives to these sorbents for promoting their reactivity were evaluated in a bench-scale reactor simulating conditions...

  3. EVALUATION OF SIMULTANEOUS SO2/NOX CONTROL TECHNOLOGY

    EPA Science Inventory

    The report gives results of work concentrating on characterizing three process operational parameters of a technology that combines sorbent injection and selective non-catalytic reduction for simultaneous sulfur dioxide/nitrogen oxide (SO2/NOx) removal from coal-fired industrial ...

  4. STATUS OF DRY SO2 CONTROL SYSTEMS: FALL 1982

    EPA Science Inventory

    The report, updating the status of dry SO2 control systems for coal-fired utility and industrial boilers in the U.S. through the Fall of 1982, is based on current and recent research, research and development, and commercial activities. Systems addressed include: (1) spray dryer/...

  5. BOILER SIMULATOR STUDIES ON SORBENT UTILIZATION FOR SO2 CONTROL

    EPA Science Inventory

    The report gives results of a program to provide process design information for sorbent utilization as applied to EPA's LIMB process. Specifically, the program was designed to investigate the role of boiler thermal history, sorbent injection location, Ca/S molar ratio, and SO2 pa...

  6. One-Dimensional SO2 Predictions for Duct Injection

    Energy Science and Technology Software Center (ESTSC)

    1993-10-05

    DIAN1D is a one-dimensional model that predicts SO2 absorption by slurry droplets injected into a flue gas stream with two-fluid atomizers. DIANUI is an interactive user interface for DIAN1D. It prepares the input file for DIAN1D from plant design specifications and process requirements.

  7. SO2 SCRUBBING TECHNOLOGIES: A REVIEW: JOURNAL ARTICLE

    EPA Science Inventory

    NRMRL-RTP-P-585 Srivastava*, R.K., Jozewicz, W., and Singer, C. SO2 Scrubbing Technologies: a Review. Environmental Progress 20 (4):219-227 (2001). EPA/600/J-02/022, Available: Environmental Progress (journal), http://www.aiche.org/publications/tocs/issuedtl.asp, [NET]. 03...

  8. Observed levels and trends of gaseous SO2 and HNO3 at Mt. Waliguan, China: results from 1997 to 2009.

    PubMed

    Lin, Weili; Xu, Xiaobin; Yu, Xiaolan; Zhang, Xiaochun; Huang, Jianqing

    2013-04-01

    Long-term measurements of SO2 and HNO3, particularly those from the background sites, are rarely reported. We present for the first time the long-term measurements of SO2 and HNO3 at Waliguan (WLG), the only global baseline station in the back-land of the Eurasian Continent. The concentrations of SO2 and HNO3 were observed at WLG from 1997 to 2009. The observed annual mean concentrations of SO2 and HNO3 at WLG were 1.28 +/- 0.41 and 0.22 +/- 0.19 microg/m3, respectively. The HNO3 concentrations were much higher in warmer seasons than in colder seasons, while the SO2 concentrations showed a nearly reversed seasonal pattern. In most months, the concentration of HNO3 was significantly correlated with that of SO2, suggesting that some common factors influence the variations of both gases and the precursors of HNO3 may partially be from the SO2-emitting sources. The SO2 concentration had a very significant (P < 0.0001) decreasing trend (-0.2 microg/(m3 x yr)) in 1997-2002, but a significant (P < 0.05) increasing trend (+0.06 microg/(m3 x yr)) in 2003-2009. The HNO3 concentration showed no statistically significant trend during 1997-2009. While the decrease of SO2 in 1997-2002 agrees with the trend of global SO2 emissions, the increase in 2003-2009 is not consistent with the decreasing trends in many other regions over the world. Trajectory analysis suggests that the airmasses from the northern Qinghai-Tibetan Plateau and the Takla Makan Desert regions contributed significantly to the increasing trends of SO2 and HNO3 at WLG in 2003-2009, with a rate of +0.13 microg/(m3 x yr) and +0.007 microg/(m3 x yr), respectively. PMID:23923781

  9. High-resolution SO2 isotopologue spectra as evidence for sulfur MIF due to SO2 self-shielding

    NASA Astrophysics Data System (ADS)

    Lyons, J. R.; Stark, G.; Blackie, D.; Pickering, J. C.

    2009-12-01

    It is well known that photolysis of some gas-phase molecules can lead to isotopic mass-independent fractionation (MIF). Several mechanisms for photolytic MIF have been proposed including 1) self-shielding during photon absorption, 2) variations in band oscillator strengths, 3) hyperfine effects, and 4) resonant curve crossing. Self-shielding, a result of line saturation in molecules with line-type absorption spectra, is observed (and predicted) in CO and N2, both of which undergo predissociation. Here, we focus on the role of self-shielding in SO2, also a predissociating molecule. Photolysis of atmospheric SO2 is believed to be the source of sulfur isotope MIF measured in early Earth sedimentary rocks (Farquhar et al. 2000). Quantitative evaluation of this hypothesis requires accurate and high-resolution absorption cross section data. We have completed 1 cm-1 resolution measurements of 32SO2, 33SO2 and 34SO2 isotopologues using a Fourier transform spectrometer (FTS) at Imperial College (IC). A detailed description of the FTS measurements will be presented by D. Blackie et al. (this meeting). Here, we present a brief overview of the data, comparison with recently published lower resolution cross section data of Danielachet et al. (2008), and interpretation via atmospheric modeling. FTS measurements were obtained at 3 pressures (0.1, 0.2 and 0.4 torr) on pure xSO2 gas (x = 32, 33 or 34) from 222 to 188 nm. Spectra were coadded to improve S/N. Visual comparison of our spectra with the lower resolution (~ 20 cm-1) spectra of Danielache et al. (2008) reveals good overall agreement for all 3 isotopologues, although the lower resolution data is unable to resolve the dense rotational structure. However, radiative transfer calculations utilizing the two sets of cross section data in a 1-D atmospheric chemistry code (assuming 10 ppb SO2) yield very different photolytic isotope fractionations. The IC cross sections yield increasing δ34S, δ33S and Δ33S values for

  10. Procedures for safe handling of off-gases from electric vehicle lead-acid batteries during overcharge

    SciTech Connect

    LaBelle, S.J.; Bhattacharyya, M.H.; Loutfy, R.O.; Varma, R.

    1980-01-25

    The potential for generation of toxic gases from lead-acid batteries has long been recognized. Prior to the current interest in electric vehicles, there were no studies specificaly oriented to toxic gas release from traction batteries, however. As the Department of Energy Demonstration Project (in the Electric and Hybrid Vehicle Program) progresses, available data from past studies and parallel health effects programs must be digested into guidance to the drivers and maintenance personnel, tailored to their contact with electric vehicles. The basic aspects of lead-acid battery operation, vehicle use, and health effects of stibine and arsine to provide electric vehicle users with the information behind the judgment that vehicle operation and testing may proceed are presented. Specifically, it is concluded that stibine generation or arsine generation at rapid enough rates to induce acute toxic response is not at all likely. Procedures to guard against low-level exposure until more definitive data on ambient concentrations of the gases are collected are presented for both charging the batteries and driving the vehicles. A research plan to collect additional quantitative data from electric traction batteries is presented.

  11. Sea salt aerosols as a reactive surface for inorganic and organic acidic gases in the Arctic troposphere

    NASA Astrophysics Data System (ADS)

    Chi, J. W.; Li, W. J.; Zhang, D. Z.; Zhang, J. C.; Lin, Y. T.; Shen, X. J.; Sun, J. Y.; Chen, J. M.; Zhang, X. Y.; Zhang, Y. M.; Wang, W. X.

    2015-10-01

    Sea salt aerosols (SSA) are dominant particles in the Arctic atmosphere and determine the polar radiative balance. SSA react with acidic pollutants that lead to changes in physical and chemical properties of their surface, which in turn alter their hygroscopic and optical properties. Transmission electron microscopy with energy-dispersive X-ray spectrometry was used to analyze morphology, composition, size, and mixing state of individual SSA at Ny-Ålesund, Svalbard, in summertime. Individual fresh SSA contained cubic NaCl coated by certain amounts of MgCl2 and CaSO4. Individual partially aged SSA contained irregular NaCl coated by a mixture of NaNO3, Na2SO4, Mg(NO3)2, and MgSO4. The comparison suggests the hydrophilic MgCl2 coating in fresh SSA likely intrigued the heterogeneous reactions at the beginning of SSA and acidic gases. Individual fully aged SSA normally had Na2SO4 cores and an amorphous coating of NaNO3. Elemental mappings of individual SSA particles revealed that as the particles ageing Cl gradually decreased, the C, N, O, and S content increased. 12C- mapping from nanoscale secondary ion mass spectrometry indicates that organic matter increased in the aged SSA compared with the fresh SSA. 12C- line scan further shows that organic matter was mainly concentrated on the aged SSA surface. These new findings indicate that this mixture of organic matter and NaNO3 on particle surfaces likely determines their hygroscopic and optical properties. These abundant SSA as reactive surfaces adsorbing inorganic and organic acidic gases can shorten acidic gas lifetime and influence the possible gaseous reactions in the Arctic atmosphere, which need to be incorporated into atmospheric chemical models in the Arctic troposphere.

  12. 40 CFR 97.288 - CAIR SO2 allowance allocations to CAIR SO2 opt-in units.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false CAIR SO2 allowance allocations to CAIR....284(g), in accordance with paragraph (b) or (c) of this section. (2) By no later than October 31 of... Trading Program under § 97.284(g) and October 31 of each year thereafter, the permitting authority...

  13. 40 CFR 97.288 - CAIR SO2 allowance allocations to CAIR SO2 opt-in units.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false CAIR SO2 allowance allocations to CAIR....284(g), in accordance with paragraph (b) or (c) of this section. (2) By no later than October 31 of... Trading Program under § 97.284(g) and October 31 of each year thereafter, the permitting authority...

  14. 40 CFR 97.288 - CAIR SO 2 allowance allocations to CAIR SO 2 opt-in units.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false CAIR SO 2 allowance allocations to....284(g), in accordance with paragraph (b) or (c) of this section. (2) By no later than October 31 of... Trading Program under § 97.284(g) and October 31 of each year thereafter, the permitting authority...

  15. 40 CFR 97.288 - CAIR SO2 allowance allocations to CAIR SO2 opt-in units.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false CAIR SO2 allowance allocations to CAIR....284(g), in accordance with paragraph (b) or (c) of this section. (2) By no later than October 31 of... Trading Program under § 97.284(g) and October 31 of each year thereafter, the permitting authority...

  16. Kinetics of SO2-ethanol-water (AVAP®) fractionation of sugarcane straw.

    PubMed

    You, Xiang; van Heiningen, Adriaan; Sixta, Herbert; Iakovlev, Mikhail

    2016-07-01

    Kinetics of SO2-ethanol-water (AVAP®) fractionation was determined for sugarcane (SC) straw in terms of pulp composition (non-carbohydrate components, cellulose, hemicelluloses) and properties (kappa number, pulp intrinsic viscosity in CED and cellulose degree of polymerization). Effect of temperature (135-165°C) and time (18-118min) was studied at fixed liquor composition (SO2/ethanol/water=12:22.5:65.5, w/w) and a liquor-to-solid ratio (4Lkg(-1)). Interpretation is given in terms of major fractionation reactions, removal of non-carbohydrate components and xylan, as well as acid hydrolysis of cellulose, and is compared to other lignocellulosic substrates (beech, spruce and wheat straw). Overall, SO2-ethanol-water process efficiently fractionates SC straw by separating cellulose from both non-carbohydrate components and xylan while reducing cellulose DP. PMID:27089426

  17. Carbon-catalyzed oxidation of SO2 by NO2 and air

    NASA Technical Reports Server (NTRS)

    Rogowski, R. S.; Schryer, D. R.; Cofer, W. R., III; Edahl, R. A., Jr.; Munavalli, S.

    1982-01-01

    A series of experiments was performed using carbon particles (commercial furnace black) as a surrogate for soot particles. Carbon particles were suspended in water, and gas mixtures were bubbled into the suspensions to observe the effect of carbon particles on the oxidation of SO2 by air and NO2. Identical gas mixtures were bubbled into a blank containing only pure water. After exposure each solution was analyzed for pH and sulfate. It was found that NO2 greatly enhances the oxidation of SO2 to sulfate in the presence of carbon particles. The amount of sulfate found in the blanks was significantly less. Under the conditions of these experiments no saturation of the reaction was observed and SO2 was converted to sulfate even in a highly acid medium (pH or = 1.5).

  18. Oxidation of SO2 by NO2 and air in an aqueous suspension of carbon

    NASA Technical Reports Server (NTRS)

    Rogowski, R. S.; Schryer, D. R.; Cofer, W. R., III; Edahl, R. A., Jr.; Munavalli, S.

    1982-01-01

    A series of experiments has been performed using carbon black as a surrogate for soot particles. Carbon black was suspended in water and gas mixtures were bubbled into the suspensions to observe the effect of carbon particles on the oxidation of SO2 by air and NO2. Identical gas mixtures were bubbled into a black containing only pure water. After exposure each solution was analyzed for pH and sulfate. It was found that NO2 greatly enhances the oxidation of SO2 to sulfate in the presence of carbon black. The amount of sulfate in the blanks was significantly less. Under the conditions of the experiments no saturation of the reaction was observed and SO2 was converted to sulfate even in a highly acid medium (pH not less than 1.5).

  19. Microwave rotational spectral study of SO2-CO

    NASA Astrophysics Data System (ADS)

    Lovas, F. J.; Sprague, M. K.

    2015-10-01

    The microwave spectrum of the molecular complex of sulfur dioxide (SO2) with carbon monoxide (CO) has been studied with a pulsed-beam Fourier Transform Microwave Spectrometer (FTMW) from a pair of gas samples of 1% by volume of SO2 and CO in Ar, and introduced via separate capillary inputs to the flow nozzle. The frequency coverage was about 7-16 GHz for various isotopomers. The molecular structure was determined with the aid of spectral studies of isotopically substituted monomers containing 13C, 18O and 34S. The rotational analyses provide the rotational and centrifugal distortion constants for all of the isotopomers analyzed. The structure determination is compared to detailed ab initio structural calculations. The electric dipole moment components along the a- and c-axis were determined from Stark effect measurements.

  20. Emissions of SO2 and NOx from biofuels in India

    NASA Astrophysics Data System (ADS)

    Gadi, Ranu; Kulshrestha, U. C.; Sarkar, A. K.; Garg, S. C.; Parashar, D. C.

    2003-07-01

    Concentrations of oxides of S and N in the atmosphere are strongly influenced by the emissions taking place from the burning of biofuels. This is particularly important in the developing countries where most of the energy requirement in the rural sector is met from biofuels. An experimental setup has been built to carry out controlled biomass burning and to derive emission factors for SO2 and NOx (NO and NO2) from various biofuels commonly used in India. Using these emission factors and the consumption data obtained from Tata Energy Research Institute's (TERI) Energy Data Directory and Yearbook 1998-99, the budget of SO2 and NOx from biofuels used in India has been estimated as 0.4 ± 0.3 and 1.0 ± 0.4 Tg, respectively, for the year 1990.

  1. Effect of airborne particle on SO 2-calcite reaction

    NASA Astrophysics Data System (ADS)

    Böke, Hasan; Göktürk, E. Hale; Caner-Saltık, Emine N.; Demirci, Şahinde

    1999-02-01

    In modern urban atmosphere, sulphur dioxide (SO 2) attacks calcite (CaCO 3) in calcareous stone-producing gypsum (CaSO 4·2H 2O) which forms crust at rain sheltered surfaces and accelerates erosion at areas exposed to rain. The airborne particles collected on stone surfaces have always been considered to enhance the gypsum crust formation and thus it is believed that they should be removed from the surface to decrease the effects of SO 2. In this study, our aim was to investigate this event by carrying out a series of experiments in laboratory using pure calcium carbonate powder to represent calcareous stone. Sodium montmorillonite, activated carbon, ferric oxide, vanadium pentoxide and cupric chloride were mixed in the pure calcium carbonate powder as substitutes of the airborne particles in the polluted atmosphere. The samples have been exposed at nearly 10 ppmv SO 2 concentrations at 90% relative humidity conditions in a reaction chamber for several days. The mineralogical composition of the exposed samples were determined by X-ray diffraction (XRD) analysis and infrared spectrometer (IR). Sulphation reaction products, calcium sulphite hemihydrate, gypsum and unreacted calcite, were determined quantitatively using IR. Exposed samples have also been investigated morphologically using a scanning electron microscope (SEM). Experimental results reveal that calcium sulphite hemihydrate is the main reaction product of the SO 2-calcite reaction. It turns out that airborne particles play an important catalytic role in the oxidation of calcium sulphite hemihydrate into gypsum, although their presence does not very significantly affect the extent of sulphation reaction. This behaviour of airborne particles is explained by the presence of liquid film on the calcium carbonate surface where a series of reactions in the gas-liquid-solid interfaces takes place.

  2. GIS-assisted dispersion of SO2 in the industrial regions.

    PubMed

    Taghizadeh, Mohamad Mehdi; Dehghani, Mansooreh; Rastgoo, Ebrahim

    2014-06-01

    Sulfur dioxide is one of the most important pollutants in urban areas which cause respiratory problems and acid rain. The aim of this research is to study the feasibility of using passive diffusive air sampling and GIS technique to determine the dispersion level of SO2 in the industrialized Zarghan area and assessing the contribution level of generating sources of SO2 in the urban areas. It is also essential to determine the contribution of other sources and dispersion radius of pollutants in the area as well. In this study, we used passive sampling method to measure the concentration of sulfur dioxide at 10 monitoring stations. Interpolation tools in ArcGIS technique create a continuous surface from measured values to predict SO2 concentration in other parts of the city. The concentrations of SO2 around Shiraz oil refinery and Dudej region located at 3 km from the oil refinery were 60 and 19 μg m(-3), respectively. In conclusion the results indicated that SO2 concentration was not exceeded the standard limit in the residential area and the role of the local highway and industrial park was not significant. PMID:26035958

  3. On the absolute calibration of SO2 cameras

    USGS Publications Warehouse

    Lübcke, Peter; Bobrowski, Nicole; Illing, Sebastian; Kern, Christoph; Alvarez Nieves, Jose Manuel; Vogel, Leif; Zielcke, Johannes; Delgados Granados, Hugo; Platt, Ulrich

    2013-01-01

    This work investigates the uncertainty of results gained through the two commonly used, but quite different, calibration methods (DOAS and calibration cells). Measurements with three different instruments, an SO2 camera, a NFOVDOAS system and an Imaging DOAS (I-DOAS), are presented. We compare the calibration-cell approach with the calibration from the NFOV-DOAS system. The respective results are compared with measurements from an I-DOAS to verify the calibration curve over the spatial extent of the image. The results show that calibration cells, while working fine in some cases, can lead to an overestimation of the SO2 CD by up to 60% compared with CDs from the DOAS measurements. Besides these errors of calibration, radiative transfer effects (e.g. light dilution, multiple scattering) can significantly influence the results of both instrument types. The measurements presented in this work were taken at Popocatepetl, Mexico, between 1 March 2011 and 4 March 2011. Average SO2 emission rates between 4.00 and 14.34 kg s−1 were observed.

  4. Co-injection of SO2 With CO2 in Geological Sequestration: Potential for Acidification of Formation Brines

    NASA Astrophysics Data System (ADS)

    Ellis, B. R.; Crandell, L. E.; Peters, C. A.

    2008-12-01

    Coal-fired power plants produce flue gas streams containing 0.02-1.4% SO2 after traditional sulfur scrubbing techniques are employed. Due to the corrosive nature of H2SO4, it will likely be necessary to remove the residual SO2 prior to carbon capture and transport; however, it may still be economically advantageous to reintroduce the SO2 to the injection stream to mitigate the cost of SO2 disposal and/or to get credits for SO2 emissions reduction. This study examines the impact of SO2 co-injection on the pH of formation brine. Using phase equilibrium modeling, it is shown that a CO2 gas stream with 1% SO2 under oxidizing conditions can create extremely acidic conditions (pH<1), but this will occur only near the CO2 plume and over a short time frame. Nearly all of the SO2 will be lost to the brine during this first phase equilibration, within approximately a decade, and the pH after the second is only 3.7, which is the pH that would occur from the carbonic acid alone. This suggests that although SO2 will create low pH values due to the formation of H2SO4, the effect will have a very limited lifespan and a localized impact spatially. SO2 is much more soluble than CO2 and as the relative of amount of SO2 to CO2 is very small, the SO2 will quickly dissolve into the formation brine. The extent of H2SO4 formation is dependent on the redox conditions of the system. Several SO2 oxidation pathways are investigated, including SO2 disproportionation which produces both sulfate and the weaker acid, H2S. Further modeling considers a time varying, diffusion limited flux of SO2. Relative to the case of instantaneous phase equilibrium, this results in a smaller decrease in pH occurring over a longer duration. Our overall conclusion is that brine acidification due to SO2 co-injection is not likely to be significant over relevant time and spatial scales.

  5. FIELD METHOD COMPARISON FOR THE CHARACTERIZATION OF ACID AEROSOLS AND GASES

    EPA Science Inventory

    This paper presents findings from two intercomparison studies of acid aerosol measurement systems, which were conducted in Uniontown and State College, PA, during the summers of 1990 and 1991, respectively. s part of these studies, acid aerosol and gas concentrations (NH3, HNO3, ...

  6. Sea salt aerosols as a reactive surface for inorganic and organic acidic gases in the arctic troposphere

    NASA Astrophysics Data System (ADS)

    Chi, J. W.; Li, W. J.; Zhang, D. Z.; Zhang, J. C.; Lin, Y. T.; Shen, X. J.; Sun, J. Y.; Chen, J. M.; Zhang, X. Y.; Zhang, Y. M.; Wang, W. X.

    2015-06-01

    Sea salt aerosols (SSA) are dominant particles in the arctic atmosphere and determine the polar radiative balance. SSA react with acidic pollutants that lead to changes of physical and chemical properties of their surface, which in turn alter their hygroscopic and optical properties. Transmission electron microscopy with energy-dispersive X-ray spectrometry was used to analyze morphology, composition, size, and mixing state of individual SSA at Ny-Ålesund, Svalbard in summertime. Individual fresh SSA contained cubic NaCl coated by certain amounts of MgCl2 and CaSO4. Individual partially aged SSA contained irregular NaCl coated by a mixture of NaNO3, Na2SO4, Mg(NO3)2, and MgSO4. The comparison suggests the hydrophilic MgCl2 coating in fresh SSA likely intrigued the heterogeneous reactions at the beginning of SSA and acidic gases. Individual fully aged SSA normally had Na2SO4 cores and an amorphous coating of NaNO3. Elemental mappings of individual SSA particles revealed that as the particles ageing Cl gradually decreased but the C, N, O, and S content increased. 12C14N- mapping from nanoscale secondary ion mass spectrometry indicates that organic matter increased in the aged SSA compared with the fresh SSA. 12C14N- line scans further show that organic matter was mainly concentrated on the aged SSA surface. These new findings indicate that this mixture of organic matter and NaNO3 on particle surfaces determines their hygroscopic and optical properties. These abundant SSA, whose reactive surfaces absorb inorganic and organic acidic gases in the arctic troposphere, need to be incorporated into atmospheric chemical models.

  7. Comparative study of the reactions of metal oxides with H2S and SO2

    NASA Astrophysics Data System (ADS)

    Sotirchos, S. V.

    1991-10-01

    The primary objective of this project is the investigation of the effects of pore structure on the capacity of porous metal oxides for removal of gaseous pollutants from flue gases of power plants (SO2) and hot coal gas (primarily H2S). Specifically, we intend to appropriately exploit the differences of the sulfidation and sulfation reactions (for instance, different molar volumes of solid products) to elucidate the dependence of the sorptive capacity of a porous sorbent on its physical microstructure. The following tasks were identified for the proposed project: (1) literature search and identification of solids to be used in experimental studies; (2) experimental study of the reaction of the chosen solids with SO2 and/or H2S; (3) experimental study of the evolution of the structure of the solids during reaction with SO2 and/or H2S using pore structure analysis and effective diffusivity measurements; and (4) model testing and validation using the obtained experimental data.

  8. Sulfide catalysts for reducing SO2 to elemental sulfur

    DOEpatents

    Jin, Yun; Yu, Qiquan; Chang, Shih-Ger

    2001-01-01

    A highly efficient sulfide catalyst for reducing sulfur dioxide to elemental sulfur, which maximizes the selectivity of elemental sulfur over byproducts and has a high conversion efficiency. Various feed stream contaminants, such as water vapor are well tolerated. Additionally, hydrogen, carbon monoxide, or hydrogen sulfides can be employed as the reducing gases while maintaining high conversion efficiency. This allows a much wider range of uses and higher level of feed stream contaminants than prior art catalysts.

  9. Double photoionization of SO 2 and fragmentation spectroscopy of SO 2++ studied by a photoion-photoion coincidence method

    NASA Astrophysics Data System (ADS)

    Dujardin, Gérald; Leach, Sydney; Dutuit, Odile; Guyon, Paul-Marie; Richard-Viard, Martine

    1984-08-01

    Doubly charged sulphur dioxide cations (SO 2++) are produced by photoionization with synchrotron radiation from ACO in the excitation-energy range 34-54 eV. A new photoion-photoion coincidence (PIPICO) experiment is described in which coincidences between photoion fragments originating from the dissociation of the doubly charged parent cation are counted. This PIPICO method enables us to study the fragmentation of individual electronically excited states of SO 2++ and to determine the corresponding absolute double-photoionization partial cross sections as a function of the excitation energy. A tentative assignment of the three observed α, β and γ SO 2++ states is given. The dissociation processes of the α and β states into the products SO + + O + are found to be non-statistical in nature; the γ state dissociates completely into three atomic fragments S + + O + + O. Three main observed features of the double-photoionization cross-section curves are discussed in the text: appearance potentials, linear threshold laws, and constant double-photoionization cross sections relative to the total ionization cross section at high energies.

  10. Evaluation of the Giggenbach bottle method using artificial fumarolic gases

    NASA Astrophysics Data System (ADS)

    Lee, S.; Jeong, H. Y.

    2013-12-01

    Volcanic eruption is one of the most dangerous natural disasters. Mt. Baekdu, located on the border between North Korea and China, has been recently showing multiple signs of its eruption. The magmatic activity of a volcano strongly affects the composition of volcanic gases, which can provide a useful tool for predicting the eruption. Among various volcanic gas monitoring methods, the Giggenbach bottle method involves the on-site sampling of volcanic gases and the subsequent laboratory analysis, thus making it possible to detect a range of volcanic gases at low levels. In this study, we aim to evaluate the effectiveness of the Giggenbach bottle method and develop the associated analytical tools using artificial fumarolic gases with known compositions. The artificial fumarolic gases are generated by mixing CO2, CO, H2S, SO2, Ar, and H2 gas streams with a N2 stream sparged through an acidic medium containing HCl and HF. The target compositions of the fumarolic gases are selected to cover those reported for various volcanoes under different tectonic environments as follows: CO2 (2-12 mol %), CO (0.3-1 mol %), H2S (0.7-2 mol %), SO2 (0.6-4 mol %), Ar (0.3-0.7 mol %), H2 (0.3-0.7 mol %), HCl (0.2-1 mol %), and HF (< 0.015 mol %). The artificial fumarolic gases are collected into an evacuated bottle partially filled with 4 M NaOH solution containing 0.5 mM Cd(CH3COO)2. While non-condensable components such as CO, Ar, H2, and N2 accumulate in the headspace of the bottle, acidic components including CO2, SO2, HCl, and HF dissolve into the alkaline solution. In case of H2S, it reacts with dissolved Cd2+ to precipitate as CdS(s). The gas accumulated in the headspace can be analyzed for CO, Ar, H2, and N2 on a gas chromatography. The alkaline solution is first separated from yellowish CdS precipitates by filtration, and then pretreated with hydrogen peroxide to oxidize dissolved SO2 (H2SO3) to SO42-. The resultant solution can be analyzed for SO2 as SO42-, HCl as Cl-, and HF

  11. Laboratory studies of interaction between trace gases and sulphuric acid or sulphate aerosols using flow-tube reactors

    NASA Astrophysics Data System (ADS)

    Leu, Ming-Taun

    Stratospheric ozone provides a protective shield for humanity and the global biosphere from harmful ultraviolet solar radiation. In past decades, theoretical models for the calculation of ozone balance frequently used gas-phase reactions alone in their studies. Since the discovery of the Antarctic ozone hole in 1985, however, it has been demonstrated that knowledge of heterogeneous reactions is needed to understand this significant natural event owing to the anthropogenic emission of chlorofluorocarbons. In this review I will briefly discuss the experimental techniques for the research of heterogeneous chemistry carried out in our laboratory. These experimental instruments include flow-tube reactors, an electron-impact ionization mass spectrometer, a chemical ionization mass spectrometer and a scanning mobility particle spectrometer. Numerous measurements of uptake coefficient (or reaction probability) and solubility of trace gases in liquid sulphuric acid have been performed under the ambient conditions in the upper troposphere and lower stratosphere, mainly 190-250 K and 40-80 wt% of H

  12. Reversible reactions between pyrite and pyrrhotite in SO2

    NASA Astrophysics Data System (ADS)

    Hausen, D. M.

    1991-04-01

    Differential thermal analysis (DTA) of iron sulfides in inert atmospheres containing varying amounts of SO2 indicates temperature-dependent reversible reactions between pyrite and pyrrhotite in the range from 350°C to 520°C. Hexagonal pyrrhotite (troilite) and sulfur dioxide interact above 350°C to form pyrite and magnetite. Pyrite decomposes endothermically to pyrrhotite and sulfur above 520°C in the same atmosphere. The sulfurization of hexagonal pyrrhotite to pyrite has been investigated kinetically by DTA and confirmed by x-ray diffraction and wet chemical analyses. The reversibility of this pyrrhotite-pyrite reaction in a sulfur dioxide atmosphere merits further metallurgical consideration.

  13. Laser stark spectroscopy of SO2 with the HCN laser

    NASA Technical Reports Server (NTRS)

    Sarker, J. C.; Johnston, L. H.; Bhattacharjee, R. L.; Sudhakaran, G. R.

    1991-01-01

    The far infrared laser Stark spectrum of SO2 was investigated using the 337-micron line of the HCN laser. Two distinct families, one originating at low field and the other at high field, were observed. The high field transition is identified. A significant fourth-order Stark shift was observed for this transition in the presence of a large second-order Stark shift. The zero-field frequency of the assigned transition was obtained by accounting for the fourth-order contribution.

  14. SO2 and NO2 over major urban regions of India: a tempo-spatial perspective

    NASA Astrophysics Data System (ADS)

    Mallik, C.; Lal, S.

    2012-12-01

    Demographic projections show that by the year 2025, 16 of the world's 29 megacities will be located in Asia, many of which have very basic problems in terms of air quality. Apart from being home to a burgeoning population, these regions of the globe are also major players in atmospheric chemistry as a result of myriad emission patterns combined with intense photochemistry. Like most of these Asian megacities, fast-paced development in some of the Indian cities has ramifications in increased emissions from industrial and transport sectors. These emissions release sulfur dioxide (SO2) and nitrogen dioxide (NO2), in addition to several pollutants, into the ambient air and have the potential to impact the chemistry and radiative balance on a regional scale. Surface measurements of these two criteria pollutants by the Central Pollution Control Board (CPCB), India during 2005-2010 from 13 urban locations in India have been analyzed to get an insight into their temporal and spatial variability. Stations are chosen to represent the entire Indian region: Indo-Gangetic plain or 'IGP' (Jalandhar, Delhi, Kanpur, Durgapur, Kolkata, Guwahati), western India (Jodhpur, Ahmedabad, Surat), central India (Nagpur, Hyderabad) and southern India (Chennai, Trivandrum). The monthly averaged surface level SO2 and NO2 have also been compared with monthly columnar averages of these gases as detected by the Ozone monitoring Instrument (OMI) over these station grids. Mean SO2 concentrations are found to be the highest for Surat (7.5 ppbv), located in a highly industrialized region. Elevated levels of NO2, observed for Durgapur and Kolkata (31 ppbv each), are close to the 24-hour 'National Ambient Air Quality' standard (30 ppbv). The surface concentrations for both SO2 and NO2 concentrations are found to be the highest during winter. Columnar SO2 over many stations show a maximum during summer monsoon. For most IGP stations, columnar NO2 values are elevated during winter. Wavelet analyses

  15. Industrial SO2 emission monitoring through a portable multichannel gas analyzer with an optimized retrieval algorithm

    NASA Astrophysics Data System (ADS)

    Sun, Youwen; Liu, Cheng; Xie, Pinhua; Hartl, Andreas; Chan, Kalok; Tian, Yuan; Wang, Wei; Qin, Min; Liu, Jianguo; Liu, Wenqing

    2016-03-01

    SO2 variability over a large concentration range and interferences from other gases have been major limitations in industrial SO2 emission monitoring. This study demonstrates accurate industrial SO2 emission monitoring through a portable multichannel gas analyzer with an optimized retrieval algorithm. The proposed analyzer features a large dynamic measurement range and correction of interferences from other coexisting infrared absorbers such as NO, CO, CO2, NO2, CH4, HC, N2O, and H2O. The multichannel gas analyzer measures 11 different wavelength channels simultaneously to correct several major problems of an infrared gas analyzer including system drift, conflict of sensitivity, interferences among different infrared absorbers, and limitation of measurement range. The optimized algorithm uses a third polynomial instead of a constant factor to quantify gas-to-gas interference. Measurement results show good performance in the linear and nonlinear ranges, thereby solving the problem that the conventional interference correction is restricted by the linearity of the intended and interfering channels. The results imply that the measurement range of the developed multichannel analyzer can be extended to the nonlinear absorption region. The measurement range and accuracy are evaluated through experimental laboratory calibration. Excellent agreement was achieved, with a Pearson correlation coefficient (r2) of 0.99977 with a measurement range from approximately 5 to 10 000 ppmv and a measurement error of less than 2 %. The instrument was also deployed for field measurement. Emissions from three different factories were measured. The emissions of these factories have been characterized by different coexisting infrared absorbers, covering a wide range of concentration levels. We compared our measurements with commercial SO2 analyzers. Overall, good agreement was achieved.

  16. A Pilot-Scale Evaluation of a New Technology to Control NO(x) Emissions from Boilers at KSC: Hydrogen Peroxide Injection into Boiler Flue Gases Followed by Wet Scrubbing of Acid Gases

    NASA Technical Reports Server (NTRS)

    Cooper, C. David

    1997-01-01

    Emissions of nitrogen oxides NO(x) are a significant problem in the United States. NO(x) are formed in any combustion process, therefore it is not surprising that NO(x) are emitted from the boilers at KSC. Research at UCF has shown (in the laboratory) that injecting H2O2 into hot simulated flue gases can oxidize the NO and NO2 to their acid gas forms, HNO2 and HNO3, respectively. These acid gases are much more water soluble than their counterparts, and theoretically can be removed easily by wet scrubbing. This technology was of interest to NASA, both for their boilers at KSC, and for their combustion sources elsewhere. However, it was necessary to field test the technology and to provide pilot-scale data to aid in design of full-scale facilities. Hence this project was initiated in May of 1996.

  17. H(2) production through electro-oxidation of SO(2): identifying the fundamental limitations.

    PubMed

    Kriek, Roelof J; Rossmeisl, Jan; Siahrostami, Samira; Björketun, Mårten E

    2014-05-28

    Sulphur dioxide (SO2), a known industrial pollutant and pulmonary irritant, is emitted to the atmosphere in excess of 120 Mt per annum. Great strides have been taken to reduce SO2 emissions, but with the growth of specifically China, and to a lesser extent India, it is on the rise again. The electrolysis of aqueous solutions of dissolved SO2 holds huge environmental potential in that SO2 is converted to sulphuric acid (H2SO4) and at the same time hydrogen gas is produced. A further benefit or incentive is that a sulphur depolarised electrolyser (SDE) operates at an applied potential that is about one volt lower than that of a regular water electrolyser. In taking this technology forward the greatest improvement to be made is in developing a suitable electrocatalyst, which is also the 'lowest hanging fruit' in that very limited research and development has been conducted on the electrocatalyst for this process. In this work, density functional theory is employed to model the electro-oxidation of SO2 on single crystal planes of the 4d and 5d transition metals. Two reaction mechanisms are considered, a HSO3 intermediate pathway and a SO3 intermediate pathway. The binding energies of all intermediates are found to scale with the surface reactivity (measured as the adsorption of OH). Irrespective of the pathway water needs to be activated and reduction of SO2 to elemental sulphur must be avoided. This requirement alone calls for an electrode potential of at least 0.7-0.8 V for all the investigated transition metals and thus challenges the proclaimed goal to operate the SDE at 0.6 V. A high chemical barrier is further found to severely limit the oxidation reaction on reactive metals. A much higher catalytic activity can be obtained on precious metals but at the cost of running the reaction at high overpotentials. PMID:24728561

  18. Kinetics of a Criegee intermediate that would survive high humidity and may oxidize atmospheric SO2.

    PubMed

    Huang, Hao-Li; Chao, Wen; Lin, Jim Jr-Min

    2015-09-01

    Criegee intermediates are thought to play a role in atmospheric chemistry, in particular, the oxidation of SO2, which produces SO3 and subsequently H2SO4, an important constituent of aerosols and acid rain. However, the impact of such oxidation reactions is affected by the reactions of Criegee intermediates with water vapor, because of high water concentrations in the troposphere. In this work, the kinetics of the reactions of dimethyl substituted Criegee intermediate (CH3)2COO with water vapor and with SO2 were directly measured via UV absorption of (CH3)2COO under near-atmospheric conditions. The results indicate that (i) the water reaction with (CH3)2COO is not fast enough (kH2O < 1.5 × 10(-16) cm(3) s(-1)) to consume atmospheric (CH3)2COO significantly and (ii) (CH3)2COO reacts with SO2 at a near-gas-kinetic-limit rate (kSO2 = 1.3 × 10(-10) cm(3) s(-1)). These observations imply a significant fraction of atmospheric (CH3)2COO may survive under humid conditions and react with SO2, very different from the case of the simplest Criegee intermediate CH2OO, in which the reaction with water dimer predominates in the CH2OO decay under typical tropospheric conditions. In addition, a significant pressure dependence was observed for the reaction of (CH3)2COO with SO2, suggesting the use of low pressure rate may underestimate the impact of this reaction. This work demonstrates that the reactivity of a Criegee intermediate toward water vapor strongly depends on its structure, which will influence the main decay pathways and steady-state concentrations for various Criegee intermediates in the atmosphere. PMID:26283390

  19. Kinetics of a Criegee intermediate that would survive high humidity and may oxidize atmospheric SO2

    PubMed Central

    Huang, Hao-Li; Chao, Wen; Lin, Jim Jr-Min

    2015-01-01

    Criegee intermediates are thought to play a role in atmospheric chemistry, in particular, the oxidation of SO2, which produces SO3 and subsequently H2SO4, an important constituent of aerosols and acid rain. However, the impact of such oxidation reactions is affected by the reactions of Criegee intermediates with water vapor, because of high water concentrations in the troposphere. In this work, the kinetics of the reactions of dimethyl substituted Criegee intermediate (CH3)2COO with water vapor and with SO2 were directly measured via UV absorption of (CH3)2COO under near-atmospheric conditions. The results indicate that (i) the water reaction with (CH3)2COO is not fast enough (kH2O < 1.5 × 10−16 cm3s−1) to consume atmospheric (CH3)2COO significantly and (ii) (CH3)2COO reacts with SO2 at a near–gas-kinetic-limit rate (kSO2 = 1.3 × 10−10 cm3s−1). These observations imply a significant fraction of atmospheric (CH3)2COO may survive under humid conditions and react with SO2, very different from the case of the simplest Criegee intermediate CH2OO, in which the reaction with water dimer predominates in the CH2OO decay under typical tropospheric conditions. In addition, a significant pressure dependence was observed for the reaction of (CH3)2COO with SO2, suggesting the use of low pressure rate may underestimate the impact of this reaction. This work demonstrates that the reactivity of a Criegee intermediate toward water vapor strongly depends on its structure, which will influence the main decay pathways and steady-state concentrations for various Criegee intermediates in the atmosphere. PMID:26283390

  20. Water independent SO2 oxidation by Stabilised Criegee Intermediates from Biogenic Alkenes

    NASA Astrophysics Data System (ADS)

    Newland, Mike; Rickard, Andrew; Vereecken, Luc; Evans, Mat; Muñoz, Amalia; Ródenas, Milagros; Bloss, William

    2015-04-01

    Biogenic VOCs account for about 90% of global VOC emissions and these are dominated by the unsaturated hydrocarbons: isoprene (600 Tg yr-1) and monoterpenes (100 Tg yr-1). Stabilized Criegee Intermediates (SCI) are thought to be formed in the atmosphere mainly from reactions of unsaturated hydrocarbons with ozone. SCI have been shown in laboratory experiments to rapidly oxidise SO2 (k > 2x10-11 cm3 s-1) and NO2 (k = 7x10-12 cm3 s-1), providing a potentially important gas phase oxidation route for these species in the atmosphere. The importance of the SCI reaction with traces gases has been shown in modelling work to be critically dependent on the ratio of the rate constants for the reaction of the SCI with these trace gases and with H2O. Such modelling work has suggested that the SCI + SO2 reaction is only likely to be important in regions with high alkene emissions, e.g. forests, and that elsewhere SCI are likely to be almost entirely quenched by reaction with water, thus negating their importance as trace gas oxidants. However, it has been shown in laboratory experiments with small SCI that the reaction rate of SCI with water is structure dependent, with anti-CH3CHOO reacting fast with H2O (k > 1x10-14 cm3 s-1), and syn-CH3CHOO reacting orders of magnitude slower (k < 2x10-16 cm3 s-1). Here we present results from a series of ozonolysis experiments performed at the EUPHORE atmospheric simulation chamber in Valencia. These experiments measure the loss of SO2, in the presence of various biogenic alkenes (isoprene and three monoterpenes: α-pinene, β-pinene and limonene), as a function of water vapour. The SO2 loss shows a dependence on relative humidity for all systems studied, decreasing with increasing relative humidity. However, for all species, there also appears to be a fraction of the SO2 loss that shows a much lower sensitivity to relative humidity. We quantify the relative rates of reaction of the SCI produced in the ozonolysis of these biogenics with

  1. Photothermal beam deflection applied to SO2 trace detection

    NASA Astrophysics Data System (ADS)

    Manzano, Francisco A.; D'Accurso, V.; Radulovich, O.

    2004-10-01

    We present the application to environmental monitoring of a compact setup for in situ trace gas detection based on photothermal beam deflection (mirage effect) spectroscopy. Gas traces measurements are performed by detecting the time-varying component of the photothermal deflection of a red diode laser beam, propagating inside the region where a pollutant is excited by another laser. In this work, detection of traces of SO2 in a mixture with Nitrogen at atmospheric pressure enclosed in a glass cell, was performed using the fourth-harmonic pulses of a 10 Hz Nd:YAG laser. It was verified by FTIR spectroscopy that negligible SO2 destruction was produced after irradiation of high pressure mixtures with 105 UV pulses. Several beam sizes and propagating angles for the UV and visible laser were tested and evaluated in order to overcome parasitic signals due to unwanted absorption in optical elements. With this setup we reached a detection limit of 5 ppbV in a hundred-second averaging time span but we estimate sub-ppbV levels can be reached by simple changes in the geometry for improving the signal to noise ratio.

  2. Supersite synergies improve volcanic SO2 flux monitoring

    NASA Astrophysics Data System (ADS)

    Burton, Michael; Di Muro, Andrea

    2014-05-01

    Both the Etna, Italy, volcano and Piton de la Fournaise (PdF), France, volcano Supersites are monitored with networks of scanning UV spectrometers. An ongoing collaboration between INGV and IPGP researchers has led to a dynamic technology transfer of novel new data analysis procedures to both networks. This new approach has been custom built to account for the particularities of both Supersites. For the Etna Supersite, the large, continuous gas emission, wide plumes and high plume height produce significant challenges for automatic networks of scanning UV spectrometers, due to the lack of a clear sky spectrum and light dilution effects. The novel approach presented here addresses both these issues. In the case of the PdF Supersite, negligible SO2 efflux is observed apart from immediately before, during and after volcanic eruptions. This necessitates a very sensitive and precise automatic analysis in order to detect the first whiffs of SO2 which act as a precursor to eruptive activity. Exactly such a solution has been developed and is demonstrated here. The technology transfer between these two Supersites promotes synergistic advantages, improving the monitoring capacity at both sites. However, until now such synergies have come about exclusively through local support from each site and the initiative of individual researchers. The full potential of such synergies can be greatly enhanced in the future if they are fully recognised and supported within the context of the Supersite initiative.

  3. Early in-flight detection of SO2 via Differential Optical Absorption Spectroscopy: a feasible aviation safety measure to prevent potential encounters with volcanic plumes

    NASA Astrophysics Data System (ADS)

    Vogel, L.; Galle, B.; Kern, C.; Delgado Granados, H.; Conde, V.; Norman, P.; Arellano, S.; Landgren, O.; Lübcke, P.; Alvarez Nieves, J. M.; Cárdenas Gonzáles, L.; Platt, U.

    2011-09-01

    Volcanic ash constitutes a risk to aviation, mainly due to its ability to cause jet engines to fail. Other risks include the possibility of abrasion of windshields and potentially serious damage to avionic systems. These hazards have been widely recognized since the early 1980s, when volcanic ash provoked several incidents of engine failure in commercial aircraft. In addition to volcanic ash, volcanic gases also pose a threat. Prolonged and/or cumulative exposure to sulphur dioxide (SO2) or sulphuric acid (H2SO4) aerosols potentially affects e.g. windows, air frame and may cause permanent damage to engines. SO2 receives most attention among the gas species commonly found in volcanic plumes because its presence above the lower troposphere is a clear proxy for a volcanic cloud and indicates that fine ash could also be present. Up to now, remote sensing of SO2 via Differential Optical Absorption Spectroscopy (DOAS) in the ultraviolet spectral region has been used to measure volcanic clouds from ground based, airborne and satellite platforms. Attention has been given to volcanic emission strength, chemistry inside volcanic clouds and measurement procedures were adapted accordingly. Here we present a set of experimental and model results, highlighting the feasibility of DOAS to be used as an airborne early detection system of SO2 in two spatial dimensions. In order to prove our new concept, simultaneous airborne and ground-based measurements of the plume of Popocatépetl volcano, Mexico, were conducted in April 2010. The plume extended at an altitude around 5250 m above sea level and was approached and traversed at the same altitude with several forward looking DOAS systems aboard an airplane. These DOAS systems measured SO2 in the flight direction and at ±40 mrad (2.3°) angles relative to it in both, horizontal and vertical directions. The approaches started at up to 25 km distance to the plume and SO2 was measured at all times well above the detection limit. In

  4. Early in-flight detection of SO2 via Differential Optical Absorption Spectroscopy: A feasible aviation safety measure to prevent potential encounters with volcanic plumes

    USGS Publications Warehouse

    Vogel, L.; Galle, B.; Kern, C.; Delgado, Granados H.; Conde, V.; Norman, P.; Arellano, S.; Landgren, O.; Lubcke, P.; Alvarez, Nieves J.M.; Cardenas, Gonzales L.; Platt, U.

    2011-01-01

    Volcanic ash constitutes a risk to aviation, mainly due to its ability to cause jet engines to fail. Other risks include the possibility of abrasion of windshields and potentially serious damage to avionic systems. These hazards have been widely recognized 5 since the early 1980s, when volcanic ash provoked several incidents of engine failure in commercial aircraft. In addition to volcanic ash, volcanic gases also pose a threat. Prolonged and/or cumulative exposure to sulphur dioxide (SO2) or sulphuric acid (H2SO4) aerosols potentially affects e.g. windows, air frame and may cause permanent damage to engines. SO2 receives most attention among the gas species commonly found in 10 volcanic plumes because its presence above the lower troposphere is a clear proxy for a volcanic cloud and indicates that fine ash could also be present. Up to now, remote sensing of SO2 via Differential Optical Absorption Spectroscopy (DOAS) in the ultraviolet spectral region has been used to measure volcanic clouds from ground based, airborne and satellite platforms. Attention has been given to vol- 15 canic emission strength, chemistry inside volcanic clouds and measurement procedures were adapted accordingly. Here we present a set of experimental and model results, highlighting the feasibility of DOAS to be used as an airborne early detection system of SO2 in two spatial dimensions. In order to prove our new concept, simultaneous airborne and ground-based measurements of the plume of Popocatepetl volcano, Mexico, were conducted in April 2010. The plume extended at an altitude around 5250 m above sea level and was approached and traversed at the same altitude with several forward looking DOAS systems aboard an airplane. These DOAS systems measured SO2 in the flight direction and at ±40 mrad (2.3◦) angles relative to it in both, horizontal and vertical directions. The approaches started at up to 25 km distance to 25 the plume and SO2 was measured at all times well above the detection

  5. Early in-flight detection of SO2 via Differential Optical Absorption Spectroscopy: a feasible aviation safety measure to prevent potential encounters with volcanic plumes

    NASA Astrophysics Data System (ADS)

    Vogel, L.; Galle, B.; Kern, C.; Delgado Granados, H.; Conde, V.; Norman, P.; Arellano, S.; Landgren, O.; Lübcke, P.; Alvarez Nieves, J. M.; Cárdenas Gonzáles, L.; Platt, U.

    2011-05-01

    Volcanic ash constitutes a risk to aviation, mainly due to its ability to cause jet engines to fail. Other risks include the possibility of abrasion of windshields and potentially serious damage to avionic systems. These hazards have been widely recognized since the early 1980s, when volcanic ash provoked several incidents of engine failure in commercial aircraft. In addition to volcanic ash, volcanic gases also pose a threat. Prolonged and/or cumulative exposure to sulphur dioxide (SO2) or sulphuric acid (H2SO4) aerosols potentially affects e.g. windows, air frame and may cause permanent damage to engines. SO2 receives most attention among the gas species commonly found in volcanic plumes because its presence above the lower troposphere is a clear proxy for a volcanic cloud and indicates that fine ash could also be present. Up to now, remote sensing of SO2 via Differential Optical Absorption Spectroscopy (DOAS) in the ultraviolet spectral region has been used to measure volcanic clouds from ground based, airborne and satellite platforms. Attention has been given to volcanic emission strength, chemistry inside volcanic clouds and measurement procedures were adapted accordingly. Here we present a set of experimental and model results, highlighting the feasibility of DOAS to be used as an airborne early detection system of SO2 in two spatial dimensions. In order to prove our new concept, simultaneous airborne and ground-based measurements of the plume of Popocatépetl volcano, Mexico, were conducted in April 2010. The plume extended at an altitude around 5250 m above sea level and was approached and traversed at the same altitude with several forward looking DOAS systems aboard an airplane. These DOAS systems measured SO2 in the flight direction and at ± 40 mrad (2.3°) angles relative to it in both, horizontal and vertical directions. The approaches started at up to 25 km distance to the plume and SO2 was measured at all times well above the detection limit. In

  6. Enhancement of acidic gases in biomass burning impacted air masses over Canada

    NASA Technical Reports Server (NTRS)

    Lefer, B. L.; Talbot, R. W.; Harriss, R. C.; Bradshaw, J. D.; Sandholm, S. T.; Olson, J. O.; Sachse, G. W.; Collins, J.; Shipham, M. A.; Blake, D. R.

    1994-01-01

    Biomass-burning impacted air masses sampled over central and eastern Canada during the summer of 1990 as part of ABLE 3B contained enhanced mixing ratios of gaseous HNO3, HCOOH, CH3COOH, and what appears to be (COOH)2. These aircraft-based samples were collected from a variety of fresh burning plumes and more aged haze layers from different source regions. Values of the enhancement factor, delta X/delta CO, where X represents an acidic gas, for combustion-impacted air masses sampled both near and farther away from the fires, were relatively uniform. However, comparison of carboxylic acid emission ratios measured in laboratory fires to field plume enhancement factors indicates significant in-plume production of HCOOH. Biomass-burning appears to be an important source of HNO3, HCOOH, and CH3COOH to the troposphere over subarctic Canada.

  7. Observations of Non-OH Oxidants of SO2 during NOMADSS and FRAPPE

    NASA Astrophysics Data System (ADS)

    Mauldin, L.; Cantrell, C. A.; Mukherjee, A. D.; Mah, R.; Apel, E. C.; Hornbrook, R. S.; Kaser, L.; Weinheimer, A. J.

    2015-12-01

    Oxidation is a key atmospheric process and impacts such issues as climate change, air quality, and acid rain. Current belief is that reactions involving OH and NO3 to be the predominate mechanism in initiating removal processes. Towards understanding these oxidative processes, the CIMS techniques for measuring OH radicals was developed. As part of this measurement a determination of non-OH SO­­­2 oxidants is made. This measurement has already changed the outlook of oxidation supporting the recent discovery that stabilized Criegee radicals (sCI) also have a significant capacity to oxidize compounds such as SO2 to ultimately form H2SO4. Here we present measurements of non-OH SO2 oxidants obtained during the Front Range Air Pollution and Photochemistry Experiment (FRAPPE) and the Nitrogen, Oxidants, Mercury, and Aerosol Distribution Sources and Sinks (NOMADSS) field campaigns. Both of these campaigns provided the opportunity to sample a broad spectrum of atmospheric environments ranging from biogenic to urban influenced air masses. These measurements reveal the sources to derive from surface emissions, with the largest concentrations observed in the boundary layer. Large non-OH SO2 oxidant concentrations are seen over areas with large emissions of biogenic species such as isoprene, supporting the idea that they are mainly stabilized Criegee radicals. However large concentrations are also seen in areas of urban outflow, possibly indicating that there may be non-OH species other than stabilized Criegees which can oxidize SO2.

  8. Flue gas SO 2/NO x control by combination of dry scrubber and electron beam

    NASA Astrophysics Data System (ADS)

    Helfritch, D. J.; Feldman, P. L.

    This study examines the feasibility of adding an electron beam between the spray dryer and the fabric filter of "dry scrubber" flue gas desulfurization (FGD) systems. The beam promises effective removal of nitrogen oxides (NO x) and sulfur dioxide (SO 2), even at higher coal-sulfur levels than usually economic for dry scrubbers. The beam excites gas molecules, promoting reactions that convert SO 2 and NO x to acids that then react with calcium compounds and are removed by the filter. The cost findings are promising for both manufacture and operation. The system uses commercially available components. The relatively low temperatures and high humidity downstream of the spray dryer favor economic beam operation. The beam removes SO 2, so the dryer can be run for economy, not high removal. Pilot scale tests will soon be carried out which are designed to verify earlier bench scale test results and to serve as the next step to full commercialization. It is expected that better than 90% SO 2 and NO x removal will be achieved.

  9. Reaction of cobalt in SO2 atmospheric at elevated temperatures

    NASA Technical Reports Server (NTRS)

    Jacobson, N. S.; Worrell, W. L.

    1983-01-01

    The reaction rate of cobalt in SO2 argon environments was measured at 650 C, 700 C, 750 C and 800 C. Product scales consist primarily of an interconnected sulfide phase in an oxide matrix. At 700 C to 800 C a thin sulfide layer adjacent to the metal is also observed. At all temperatures, the rapid diffusion of cobalt outward through the interconnected sulfide appears to be important. At 650 C, the reaction rate slows dramatically after five minutes due to a change in the distribution of these sulfides. At 700 C and 750 C the reaction is primarily diffusion controlled values of diffusivity of cobalt (CoS) calculated from this work show favorable agreement with values of diffusivity of cobalt (CoS) calculated from previous sulfidation work. At 800 C, a surface step becomes rate limiting.

  10. Reaction of cobalt in SO2 atmospheres at elevated temperatures

    NASA Technical Reports Server (NTRS)

    Jacobson, N. S.; Worrell, W. L.

    1984-01-01

    The reaction rate of cobalt in SO2 argon environments was measured at 650 C, 700 C, 750 C and 800 C. Product scales consist primarily of an interconnected sulfide phase in an oxide matrix. At 700 C to 800 C, a thin sulfide layer adjacent to the metal is also observed. At all temperatures, the rapid diffusion of cobalt outward through the interconnected sulfide appears to be important. At 650 C, the reaction rate slows dramatically after five minutes due to a change in the distribution of these sulfides. At 700 C and 750 C, the reaction is primarily diffusion controlled; values of diffusivity of cobalt (CoS) calculated from this work show favorable agreement with values of diffusivity of cobalt (CoS) calculated from previous sulfidation work. At 800 C, a surface step becomes rate limiting. Previously announced in STAR as N83-35104

  11. Noncommutative SO(2,3) gauge theory and noncommutative gravity

    NASA Astrophysics Data System (ADS)

    Dimitrijević, Marija; Radovanović, Voja

    2014-06-01

    In this paper noncommutative gravity is constructed as a gauge theory of the noncommutative SO(2,3)⋆ group, while the noncommutativity is canonical (constant). The Seiberg-Witten map is used to express noncommutative fields in terms of the corresponding commutative fields. The commutative limit of the model is the Einstein-Hilbert action with the cosmological constant term and the topological Gauss-Bonnet term. We calculate the second order correction to this model and obtain terms that are of zeroth to fourth power in the curvature tensor and torsion. Trying to relate our results with f(R) and f(T) models, we analyze different limits of our model. In the limit of big cosmological constant and vanishing torsion we obtain an x-dependent correction to the cosmological constant; i.e. noncommutativity leads to an x-dependent cosmological constant. We also discuss the limit of small cosmological constant and vanishing torsion and the teleparallel limit.

  12. Io's Thermal Regions and Non-SO2 Spectral Features

    NASA Technical Reports Server (NTRS)

    Smythe, W. D.; Soderblom, L. A.; Lopes, R. M. C.

    2003-01-01

    Several absorptions have been identified in the Galileo NIMS spectra of Io that are not related to SO2. [1,2]. These absorptions have band centers at 2.97, 3.15, 3.85, and 3.91 microns. There are also broad absorptions in the regions 1-1.3 and 3- 3.4 microns. Patterning noise in wavelength registration, arising from the pushbroom imaging and grating motion of the NIMS instrument have previously inhibited reliable mapping of weak absorptions. Recent improvements in techniques to remove the coherent pattern noise from the NIMS dataset have been made by Soderblom. This greatly improves the signal to noise ratio and enables mapping of weak spectral signatures such as the 3.15 micron absorption on Io.

  13. SO2 flux and the thermal power of volcanic eruptions

    NASA Astrophysics Data System (ADS)

    Henley, Richard W.; Hughes, Graham O.

    2016-09-01

    A description of the dynamics, chemistry and energetics governing a volcanic system can be greatly simplified if the expansion of magmatic gas can be assumed to be adiabatic as it rises towards the surface. The conditions under which this assumption is valid are clarified by analysis of the transfer of thermal energy into the low conductivity wallrocks traversed by fractures and vents from a gas phase expanding over a range of mass flux rates. Adiabatic behavior is predicted to be approached typically within a month after perturbations in the release of source gas have stabilized, this timescale being dependent upon only the characteristic length scale on which the host rock is fractured and the thermal diffusivity of the rock. This analysis then enables the thermal energy transport due to gas release from volcanoes to be evaluated using observations of SO2 flux with reference values for the H2O:SO2 ratio of volcanic gas mixtures discharging through high temperature fumaroles in arc and mantle-related volcanic systems. Thermal power estimates for gas discharge are 101.8 to 104.1 MWH during quiescent, continuous degassing of arc volcanoes and 103.7 to 107.3 MWH for their eruptive stages, the higher value being the Plinean Pinatubo eruption in 1991. Fewer data are available for quiescent stage mantle-related volcanoes (Kilauea 102.1 MWH) but for eruptive events power estimates range from 102.8 MWH to 105.5 MWH. These estimates of thermal power and mass of gas discharges are commensurate with power estimates based on the total mass of gas ejected during eruptions. The sustained discharge of volcanic gas during quiescent and short-lived eruptive stages can be related to the hydrodynamic structure of volcanic systems with large scale gaseous mass transfer from deep in the crust coupled with episodes of high level intrusive activity and gas release.

  14. Measurement and analysis of the relationship between ammonia, acid gases, and fine particles in eastern North Carolina.

    PubMed

    Baek, Bok Haeng; Aneja, Viney P

    2004-05-01

    An annular denuder system, which consisted of a cyclone separator; two diffusion denuders coated with sodium carbonate and citric acid, respectively; and a filter pack consisting of Teflon and nylon filters in series, was used to measure acid gases, ammonia (NH3), and fine particles in the atmosphere from April 1998 to March 1999 in eastern North Carolina (i.e., an NH3-rich environment). The sodium carbonate denuders yielded average acid gas concentrations of 0.23 microg/m3 hydrochloric acid (standard deviation [SD] +/- 0.2 microg/m3); 1.14 microg/m3 nitric acid (SD +/- 0.81 microg/m3), and 1.61 microg/m3 sulfuric acid (SD +/- 1.58 microg/m3). The citric acid denuders yielded an average concentration of 17.89 microg/m3 NH3 (SD +/- 15.03 microg/m3). The filters yielded average fine aerosol concentrations of 1.64 microg/m3 ammonium (NH4+; SD +/- 1.26 microg/m3); 0.26 microg/m3 chloride (SD +/- 0.69 microg/m3), 1.92 microg/m3 nitrate (SD +/- 1.09 microg/m3), and 3.18 microg/m3 sulfate (SO4(2-); SD +/- 3.12 microg/m3). From seasonal variation, the measured particulates (NH4+, SO4(2-), and nitrate) showed larger peak concentrations during summer, suggesting that the gas-to-particle conversion was efficient during summer. The aerosol fraction in this study area indicated the domination of ammonium sulfate particles because of the local abundance of NH3, and the long-range transport of SO4(2-) based on back trajectory analysis. Relative humidity effects on gas-to-particle conversion processes were analyzed by particulate NH4+ concentration originally formed from the neutralization processes with the secondary pollutants in the atmosphere. PMID:15149049

  15. Separation and identification of carboxylic acids in MALT samples from the headspace gases in Hanford tank 103C

    SciTech Connect

    Clauss, S.A.; Lucke, R.B.

    1993-08-01

    Samples of headspace gases from Westinghouse Hanford Company (WHC) waste storage tank 103C were analyzed by gas chromatography/mass spectrometry by Pacific Northwest Laboratory staff. The samples were obtained using a cryo-trap sampler designed by WHC and known as the Mobile Analytical Laboratory Trap (MALT). The samples, which were obtained in September 1989, were available in large amounts (200 mi). The specific targets for this analysis were n-butyric, i-butyric, n-valeric, and i-valeric organic acids. Of the acids targeted, only n-butyric was found, and only trace amounts of it were detected with a detection limit below 1 ppM in the extract. The levels found were so low as to cause difficulty in quantitation. All concentrations reported here are for the methanol extract solutions and not the concentrations in the headspace of tank 103C. To calculate concentrations in the headspace, the MALT sampling volume and the methanol rinse volume must be obtained from the MALT personnel at WHC.

  16. Adsorption and oxidation of SO2 by graphene oxides: A van der Waals density functional theory study

    NASA Astrophysics Data System (ADS)

    Zhang, Huijuan; Cen, Wanglai; Liu, Jie; Guo, Jiaxiu; Yin, Huaqiang; Ning, Ping

    2015-01-01

    Carbon materials have been used for low temperature (20-150 °C) catalytic removal of SO2 from the coal-burned flue gases for a long time, but the mechanism at atomic level is still controversial. Density functional theory was used to investigate the adsorption and oxidation of SO2 on elaborated graphene oxides (GOs) to discover the insights. It is found that the hydroxyl groups on GO surface possess bi-functional effects: both enhancing the adsorption of SO2 through H-bonding interaction and reducing the reaction barrier for its oxidation to SO3. The promotion of oxidation is related to a pre-activation of the surface epoxy group. Based on Bader population, charge difference and electron localization function analysis, a charge transfer channel is proposed to explain the pre-activation.

  17. Application of V2O5/WO3/TiO2 for Resistive-Type SO2 Sensors

    PubMed Central

    Izu, Noriya; Hagen, Gunter; Schönauer, Daniela; Röder-Roith, Ulla; Moos, Ralf

    2011-01-01

    A study on the application of V2O5/WO3/TiO2 (VWT) as the sensitive material for resistive-type SO2 sensor was conducted, based on the fact that VWT is a well-known catalyst material for good selective catalytic nitrogen oxide reduction with a proven excellent durability in exhaust gases. The sensors fabricated in this study are planar ones with interdigitated electrodes of Au or Pt. The vanadium content of the utilized VWT is 1.5 or 3.0 wt%. The resistance of VWT decreases with an increasing SO2 concentration in the range from 20 ppm to 5,000 ppm. The best sensor response to SO2 occurs at 400 °C using Au electrodes. The sensor response value is independent on the amount of added vanadium but dependent on the electrode materials at 400 °C. These results are discussed and a sensing mechanism is discussed. PMID:22163780

  18. Investigation of SO2, HCl and NOx, control from waste incinerators using a novel additive in a pilot scale reactor.

    PubMed

    Williams, P T; Nimmo, W; Patsias, A; Hall, W

    2006-05-01

    A pilot scale experimental investigation of the use of a novel additive, calcium magnesium acetate, for the simultaneous control of SO2, HCl and NOx has been carried out. The pilot scale reactor simulated the furnace and flue gas conditions of a typical large scale waste incinerator and was a vertical 4m high reactor operated at 80 kW. The calcium magnesium acetate was added as a wet spray to the reactor at temperatures above 750 degrees C. The influence of the calcium magnesium acetate dose rate was investigated on the simultaneous removal of SO2, HCl and NOx. Maximum reductions were achieved at a Ca/S ratio (or Ca/Cl ratio) of 2.5 and were, 70% for SO2, 45% for HCl and 18% for NOx for each of the pollutant gases respectively. PMID:16749624

  19. Continuous desulfurization and bacterial community structure of an integrated bioreactor developed to treat SO2 from a gas stream.

    PubMed

    Lin, Jian; Li, Lin; Ding, Wenjie; Zhang, Jingying; Liu, Junxin

    2015-11-01

    Sulfide dioxide (SO2) is often released during the combustion processes of fossil fuels. An integrated bioreactor with two sections, namely, a suspended zone (SZ) and immobilized zone (IZ), was applied to treat SO2 for 6months. Sampling ports were set in both sections to investigate the performance and microbial characteristics of the integrated bioreactor. SO2 was effectively removed by the synergistic effect of the SZ and IZ, and more than 85% removal efficiency was achieved at steady state. The average elimination capacity of SO2 in the bioreactor was 2.80g/(m(3)·hr) for the SZ and 1.50g/(m(3)·hr) for the IZ. Most SO2 was eliminated in the SZ. The liquid level of the SZ and the water content ratio of the packing material in the IZ affected SO2 removal efficiency. The SZ served a key function not only in SO2 elimination, but also in moisture maintenance for the IZ. The desired water content in IZ could be feasibly maintained without any additional pre-humidification facilities. Clone libraries of 16S rDNA directly amplified from the DNA of each sample were constructed and sequenced to analyze the community composition and diversity in the individual zones. The desulfurization bacteria dominated both zones. Paenibacillus sp. was present in both zones, whereas Ralstonia sp. existed only in the SZ. The transfer of SO2 to the SZ involved dissolution in the nutrient solution and biodegradation by the sulfur-oxidizing bacteria. This work presents a potential biological treatment method for waste gases containing hydrophilic compounds. PMID:26574096

  20. Acidification of rain in the presence of SO2, H2O2, O3, and HNO3

    SciTech Connect

    Overton, J.H. Jr; Durham, J.L.

    1982-01-01

    The production of acid sulfate and the accumulation of acid nitrate are calculated for falling raindrops using a physico-chemical model that accounts for the mass transfer of SO2, H2O2, O3, HNO3, and CO2. The acidification is postulated to occur through the absorption of free gaseous HNO3 and the absorption and reaction of SO2, H2O2, and O3 to yield H2SO4. Investigated are the relative effectivness of H2O2(aq) and O3(aq) for oxidizing SO2(aq) to yield H(+1) and SO-2(-2), and the role of HNO3(aq) in acidifying raindrops and influencing SO4(-2) formation. Results indicate: that H2O2 is more effective than O3, HNO3 inhibits SO4(-2) formation due to O3 oxidation, and in all cases, HNO3 is important in acidifying rain.

  1. The enhanced oxidation of SO2 by NO2 on carbon particulates

    NASA Technical Reports Server (NTRS)

    Cofer, W. R., III; Schryer, D. R.; Rogowski, R. S.

    1980-01-01

    The oxidation of SO2 on carbon particles in dry air and in air at 65% relative humidity (RH) was found to be greatly enhanced by the presence of gaseous NO2. Exposures of 20-80ppm SO2 + 10ppm NO2 on 1-mg samples of commercial carbon black were found to produce both sorption and desorption coverages (weight retained after desorption into N2) of over one order of magnitude greater than for corresponding SO2 exposures. Significant agglomeration and wetting were observed to occur progressively during exposures at 65% RH, and samples, even after 150-h exposure, rarely reached steady-state weight gain. The wetting may have regenerated fresh reactive carbon surface. Sorptions conducted in nitrogen atmospheres, rather than in air, appeared to produce slightly higher sorptions and weight retentions for equivalent exposure concentrations and times, indicating that NO2 served as the oxidizer and that molecular oxygen, or some trace constitutents in air, may have weakly inhibited the oxidation by NO2. Wet chemical analysis of the desorbed phase indicated that sulfate, presumably H2SO4 accounted for over half of the retained weight. Measurements of pH from water-quenched samples indicated a highly acidic surface phase, and suggested the oxidation process could proceed in an acidic environment.

  2. Aqueous phase oxidation of SO2 by O3 measured at the CERN CLOUD chamber

    NASA Astrophysics Data System (ADS)

    Hoyle, Christopher; Fuchs, Claudia; Gysel, Martin; Troestl, Jasmin; El Haddad, Imad; Frege, Carla; Dommen, Josef; Dias, Antonio; Jaervinen, Emma; Moehler, Ottmar; Baltensperger, Urs

    2015-04-01

    Measurements of aerosol growth due to the oxidation of SO2 by O3 in cloud droplets at temperatures of 10° C and -10° C are presented. Although this reaction has been well studied in bulk solutions at temperatures above 0° C, this is, to the best of our knowledge, the first time the reaction rate has been studied in laboratory formed, super-cooled cloud droplets. These experiments were made possible by utilising the adiabatic expansion system in the 27 m3 CLOUD (Cosmics Leaving Outdoor Droplets) chamber at CERN. Experiments were performed on both acidic (sulphuric acid) and neutral (ammonium sulphate) seed aerosol. During 6 minute cloud cycles, droplets of approximately 10μm diameter were formed, and the growth of the aerosol due to the uptake and oxidation of SO2 was measured with a scanning mobility particle sizer (SMPS). A microphysical model was developed to simulate the cloud droplet activation and growth as well as the aqueous phase chemistry. The ability of the model to accurately represent the observed aerosol growth is assessed, and the implications for the extrapolation of the SO2+O3oxidation rates to sub-zero temperatures are discussed.

  3. Modeling of SO2 dispersion from the 2014 Holuhraun eruption in Iceland using WRF-Chem

    NASA Astrophysics Data System (ADS)

    Rognvaldsson, Olafur; Arnason, Gylfi; Palsson, Thorgeir; Eliasson, Jonas; Weber, Konradin; Böhlke, Christoph; Thorsteinsson, Throstur; Tirpitz, Lukas; Platt, Ulrich; Smith, Paul D.; Jones, Roderic L.

    2015-04-01

    The fissure eruption in Holuhraun in central Iceland is the country's largest lava and gas eruption since 1783 but has produced very little volcanic ash. The eruption started in late August 2014 and is still ongoing as of January 2015. The main threat from this event has been atmospheric pollution of SO2 that is carried by wind to all parts of the country and produces elevated concentrations of SO2 that have frequently violated National Air Quality Standards (NAQS) in many population centers. The Volcanic Ash Research (VAR) group in Iceland is focused on airborne measurement of ash contamination to support safe air travel, as well as various gas concentrations. In relation to the Holuhraun eruption the VAR group has organized an investigation campaign including 10 measurement flights and performed measurements of both the source emissions and the plume distribution. SO2 concentrations measured at the source showed clear potential for creating pollution events in the toxic range and contamination of surface waters. The data obtained in the measurement campaign was used for calibration of the WRF-chem model of the dispersion of SO2 and volcanic ash concentration. The model has both been run in operational forecast mode (since mid October) as well as in a dynamical downscaling mode, to estimate the dispersion and fallout of SO2 from the plume. The model results indicate that a large part of the sulphur was precipitated in the Icelandic highlands. The first melt waters during the spring thaw are likely to contain acid sulphur compounds that can be harmful for vegetation, with the highland vegetation being the most vulnerable. These results will be helpful to estimate the pollution load on farmlands and pastures of farmers.

  4. forced overdischarge related safety aspects of Li/SO2 and Li/SOCl2 cells

    NASA Technical Reports Server (NTRS)

    Abraham, K. M.

    1983-01-01

    Results of an experiment investigating overdischarge behavior of two types of Li/SO2 cells are presented. Forced overdischarges of the Li/LiBr, CH3CN/SO2 cell can result in unsafe behavior such as venting with fire and release of toxic gases. The hazards may be minimized or eliminated by careful cell design considerations and practice of high standards of quality contol in cell manufacture. Seemingly safe cells at 25 C when forced overdischarged at -25 C, even at low currents, exhibited incipient signs of hazards. Their cathodes indicated signs of shock sensitivity. Cathode limited Li/SOCl2 cells were safe during forced overdischarge for long periods of time. Lithium limited Li/SOCl2 cells in which practically all Li had been used up before cell reversal did not exhibit hazardous behavior. Anode limited Li/SOCl2 cells, but not Li limited, exhibited detonations, all during overdischarges at relatively low current densities of or = 1 mA/sq cm 2. Anode potentials 4v with large oscillations preceeded the events. The events were confined to the anode and the temperature rose high enough to melt Ni grids.

  5. Volcanic Ash a Sink for Atmospheric Trace Species? A Laboratory Study of SO2 and O3 Uptake by Ash

    NASA Astrophysics Data System (ADS)

    Maters, E. C.; Delmelle, P.; Rossi, M. J.

    2015-12-01

    The impacts of volcanic activity on atmospheric chemistry have dominantly been viewed in relation to sulphur and halogen gas and aerosol emissions, while volcanic ash has been largely overlooked. However, solid particles in the atmosphere are increasingly recognised to be important in providing surfaces for heterogeneous reaction with trace gases such as SO2, NOx, O3 and organic compounds. Average annual emissions of ash, the <2 mm aluminosilicate particles generated during explosive eruptions, correspond to a surface area roughly equivalent to one-third to one-half of Earth's geometric surface area. Despite the substantial surface presented by airborne ash particles, interactions between ash and gases at ambient temperature have seldom been investigated. Laboratory studies with volcanic ash similar to those conducted with mineral dust from arid and semi-arid regions are much needed to understand and quantify the kinetics and mechanisms involved in heterogeneous reactions. Addressing this gap in knowledge is fundamental to better assess the capacity of ash emissions to affect atmospheric chemistry. We determined the initial uptake coefficient (γM) and the total uptake capacity (NiM) for gaseous SO2 and O3 by a compositional range of ash and glass powders in a Knudsen flow reactor. The volcanic materials exhibited γSO2 and NiSO2 values ranging from 10-3 to 10-2 and from 1011 to 1013 molecules cm-2, respectively. The solids samples also showed γO3 and NiO3 values ranging from 10-3 to 10-2 and from 1012 to 1013 molecules cm-2, respectively. Results of sequential exposure trials (SO2 then O3, O3 then SO2) suggest that SO2 and O3 do not compete for surface sites on the aluminosilicate materials, although O3 may participate in redox reactions with surface adsorbed sulphur species, enhancing the total capacity for O3 uptake by the solid. Differences in reactivity of the samples towards SO2 and O3 may be interpreted in light of variations in types and abundances of

  6. ACIDIFICATION OF RAIN IN THE PRESENCE OF SO2, H2O2, O3, AND HNO3

    EPA Science Inventory

    The production of acid sulfate and the accumulation of acid nitrate are calculated for falling raindrops using a physico-chemical model that accounts for the mass transfer of SO2, H2O2, O3, HNO3, and CO2. The acidification is postulated to occur through the absorption of free gas...

  7. Feulgen type staining with Hoffmann's violet-SO2 under exposure to UV rays.

    PubMed

    Dutt, M K

    1979-07-01

    The paper contains an account of the use of Hoffmann's violet-SO2 under exposure to UV rays during staining acid-hydrolysed DNA of mammalian tissue nuclei. Preparations stained with Hoffmann's violet-SO2 without exposure to UV rays reveal extremely pale violet nuclei but when stained under the influence of UV rays show a considerably faster reaction resulting in a very much deeper staining of the nuclei. Sections after staining with this dye-reagent require n-butanol as differentiating reagent. Possible interpretation for the increase in staining ability of this dye-reagent under exposure to UV rays has been elucidated and the reason for considering the reaction as Feulgen type has been discussed. PMID:91084

  8. Influence of Tropospheric SO2 Emissions on Particle Formation and the Stratospheric Humidity

    NASA Technical Reports Server (NTRS)

    Notholt, J.; Luo, B. P.; Fueglistaler, S.; Weisenstein, D.; Rex, M.; Lawrence, M. G.; Bingemer, H.; Wohltmann, I.; Corti, T.; Warneke, T.; vonKuhlmann, R.; Peters, T.

    2005-01-01

    Stratospheric water vapor plays an important role in the chemistry and radiation budget of the stratosphere. Throughout the last decades stratospheric water vapor levels have increased and several processes have been suggested to contribute to this trend. Here we present a mechanism that would link increasing anthropogenic SO2 emissions in southern and eastern Asia with an increase in stratospheric water. Trajectory studies and model simulations suggest that the SO2 increase results in the formation of more sulfuric acid aerosol particles in the upper tropical troposphere. As a consequence, more ice crystals of smaller size are formed in the tropical tropopause, which are lifted into the stratosphere more readily. Our model calculations suggest that such a mechanism could increase the amount of water that entered the stratosphere in the condensed phase by up to 0.5 ppmv from 1950-2000.

  9. Quantum-chemical study of CHCl3-SO2 association.

    PubMed

    Hippler, Michael

    2005-11-22

    CHCl(3)-SO(2) association is studied by high-level quantum-chemical calculations of stationary points of the dimer electronic potential-energy hypersurface, including correlated second-order Moller-Plesset and CCSD(T) calculations with basis sets up to 6-311++G(d,p). During geometry optimization, frequency, and energy calculations, a self-written computer code embedding the GAMESS ab initio program suite applies counterpoise correction of the basis set superposition error. A CH...O hydrogen-bonded complex (DeltaE(0)=-8.73 kJmol) with a 2.4 A intermolecular H...O distance and two very weak van der Waals complexes (DeltaE(0)=-3.78 and -2.94 kJmol) are located on the counterpoise-corrected potential-energy surface. The intermolecular interactions are characterized by Kitaura-Morokuma interaction energy decompositions and Mulliken electron population analyses. The unusual hydrogen bond is distinguished by a CH-bond contraction, a pronounced enhancement of the IR intensity and a shift to higher frequency ("blueshift") of the CH-stretching vibration compared to the CHCl(3) monomer. Spectroscopy and association in liquid solution is also discussed; our results provide an alternative explanation for features in the CH-stretching vibration spectrum of chloroform dissolved in liquid sulfur dioxide which have been attributed previously to an intermolecular Fermi resonance. PMID:16351260

  10. Quantum-chemical study of CHCl3-SO2 association

    NASA Astrophysics Data System (ADS)

    Hippler, Michael

    2005-11-01

    CHCl3-SO2 association is studied by high-level quantum-chemical calculations of stationary points of the dimer electronic potential-energy hypersurface, including correlated second-order Møller-Plesset and CCSD(T) calculations with basis sets up to 6-311++G(d,p). During geometry optimization, frequency, and energy calculations, a self-written computer code embedding the GAMESS ab initio program suite applies counterpoise correction of the basis set superposition error. A CH ⋯O hydrogen-bonded complex (ΔE0=-8.73kJ/mol) with a 2.4Å intermolecular H ⋯O distance and two very weak van der Waals complexes (ΔE0=-3.78 and -2.94kJ /mol) are located on the counterpoise-corrected potential-energy surface. The intermolecular interactions are characterized by Kitaura-Morokuma interaction energy decompositions and Mulliken electron population analyses. The unusual hydrogen bond is distinguished by a CH-bond contraction, a pronounced enhancement of the IR intensity and a shift to higher frequency ("blueshift") of the CH-stretching vibration compared to the CHCl3 monomer. Spectroscopy and association in liquid solution is also discussed; our results provide an alternative explanation for features in the CH-stretching vibration spectrum of chloroform dissolved in liquid sulfur dioxide which have been attributed previously to an intermolecular Fermi resonance.

  11. Theoretical assignment of the Clements bands of SO2

    NASA Astrophysics Data System (ADS)

    Lévêque, Camille; Taïeb, Richard; Köppel, Horst

    2015-10-01

    The photoabsorption spectrum of SO2 is theoretically investigated in the energy range 3.56-4.05 eV (28713-32665 cm-1). The lowest vibronic levels of the coupled excited electronic states (11A2 / 11B1) have been computed using Lanczos diagonalization of the Hamiltonian. The potential energy surfaces and the diabatization scheme used here were already successfully applied to describe the non-adiabatic dynamics of the molecule (Lévêque et al., 2013). The important vibronic states, playing a role in the experimental spectrum, have been analyzed according to their nodal pattern to propose the first theoretical assignment of the low-energy part of the spectrum. The Clements bands A-D have been assigned and exhibit contributions from numerous transitions, in the low resolution spectrum. The overlap of these transitions is shown to provide an "accidental" regularity of the Clements bands with respect to their intensities, while their regular energy spacing (∼ 220 cm-1) results from a unique series (4,n2,1).

  12. In-vivo measurement of intrauterine gases and acid-base values early in human pregnancy.

    PubMed

    Jauniaux, E; Watson, A; Ozturk, O; Quick, D; Burton, G

    1999-11-01

    A new multiparameter sensor that combines electrochemical and fibre-optic technology was used for continuous in-vivo investigation of pH, carbon dioxide partial pressure (PCO(2)), oxygen partial pressure (PO(2)), bicarbonate concentration (HCO(3)(-)), base excess, and oxygen saturation (O(2)Sat) early in human pregnancy. The sensor was inserted into the amniotic cavity and the placental bed of 16 pregnancies at 10-15 weeks gestation, before termination under general anaesthesia. Amniotic fluid and retroplacental blood from the same site were also aspirated and analysed by means of cartridges and a portable blood gas analyser. Eleven series of measurements were obtained. The variation in measurements over the 5 min of monitoring was acid-base with a sensor is stable and accurate. Such technology will be helpful in improving our understanding of the fetoplacental metabolism in normal and complicated pregnancies. PMID:10548645

  13. Sensitivity of OMI SO2 measurements to variable eruptive behaviour at Soufrière Hills Volcano, Montserrat

    NASA Astrophysics Data System (ADS)

    Hayer, C. S.; Wadge, G.; Edmonds, M.; Christopher, T.

    2016-02-01

    Since 2004, the satellite-borne Ozone Mapping Instrument (OMI) has observed sulphur dioxide (SO2) plumes during both quiescence and effusive eruptive activity at Soufrière Hills Volcano, Montserrat. On average, OMI detected a SO2 plume 4-6 times more frequently during effusive periods than during quiescence in the 2008-2010 period. The increased ability of OMI to detect SO2 during eruptive periods is mainly due to an increase in plume altitude rather than a higher SO2 emission rate. Three styles of eruptive activity cause thermal lofting of gases (Vulcanian explosions; pyroclastic flows; a hot lava dome) and the resultant plume altitudes are estimated from observations and models. Most lofting plumes from Soufrière Hills are derived from hot domes and pyroclastic flows. Although Vulcanian explosions produced the largest plumes, some produced only negligible SO2 signals detected by OMI. OMI is most valuable for monitoring purposes at this volcano during periods of lava dome growth and during explosive activity.

  14. Potential effects of clean coal technologies on acid precipitation, greenhouse gases, and solid waste disposal

    SciTech Connect

    Blasing, T.J.; Miller, R.L.; McCold, L.N.

    1993-11-01

    The US Department of Energy`s (DOE`s) Clean Coal Technology Demonstration Program (CCTDP) was initially funded by Congress to demonstrate more efficient, economically feasible, and environmentally acceptable coal technologies. Although the environmental focus at first was on sulfur dioxide (SO{sub 2}) and nitrogen oxides (NO{sub x}) because their relationship to acid precipitation, the CCTDP may also lead to reductions in carbon dioxide (CO{sub 2}) emissions and in the volume of solid waste produced, compared with conventional technologies. The environmental effects of clean coal technologies (CCTs) depend upon which (if any) specific technologies eventually achieve high acceptance in the marketplace. In general, the repowering technologies and a small group of retrofit technologies show the most promise for reducing C0{sub 2} emissions and solid waste. These technologies also compare favorably with other CCTs in terms of SO{sub 2} and NO{sub x} reductions. The upper bound for CO{sup 2} reductions in the year 2010 is only enough to reduce global ``greenhouse`` warming potential by about 1%. However, CO{sub 2} emissions come from such variety of sources around the globe that no single technological innovation or national policy change could realistically be expected to reduce these emissions by more than a few percent. Particular CCTs can lead to either increases or decreases in the amount of solid waste produced. However, even if decreases are not achieved, much of the solid waste from clean coal technologies would be dry and therefore easier to dispose of than scrubber sludge.

  15. PROCEEDINGS: JOINT SYMPOSIUM ON DRY SO2 AND SIMULTANEOUS SO2/NOX CONTROL TECHNOLOGIES (1ST). VOLUME 1. FUNDAMENTAL RESEARCH AND PROCESS DEVELOPMENT

    EPA Science Inventory

    Forty six papers describing recent advances in dry sorbent injection technologies for SO2 control were presented at the 1st Joint Symposium on Dry SO2 and Simultaneous SO2/NOx Control Technologies. These papers covered the following topics: fundamental research; pilot-scale devel...

  16. 40 CFR Appendix C to Part 72 - Actual 1985 Yearly SO2 Emissions Calculation

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PROGRAMS (CONTINUED) PERMITS REGULATION Pt. 72, App. C Appendix C to Part 72—Actual 1985 Yearly SO2... = (coal SO2 emissions) + (oil SO2 emissions) (in tons) If gas is the only fuel, gas emissions...

  17. 40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... discharged to the atmosphere from a designated facility is 27 milligrams per dry standard cubic meter... contained in the gases discharged to the atmosphere from a designated facility is 25 milligrams per dry... the gases discharged to the atmosphere from a designated facility is 10 percent (6-minute average)....

  18. 40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... facility shall cause to be discharged into the atmosphere from that affected facility any gases that... operator of an affected facility shall cause to be discharged into the atmosphere from that affected... atmosphere from that affected facility any gases that contain cadmium in excess of the limits specified...

  19. 40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... discharged to the atmosphere from a designated facility is 27 milligrams per dry standard cubic meter... contained in the gases discharged to the atmosphere from a designated facility is 25 milligrams per dry... the gases discharged to the atmosphere from a designated facility is 10 percent (6-minute average)....

  20. 40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... facility shall cause to be discharged into the atmosphere from that affected facility any gases that... operator of an affected facility shall cause to be discharged into the atmosphere from that affected... atmosphere from that affected facility any gases that contain cadmium in excess of the limits specified...

  1. Measurements of HONO, NO, NOy and SO2 in aircraft exhaust plumes at cruise

    NASA Astrophysics Data System (ADS)

    Jurkat, T.; Voigt, C.; Arnold, F.; Schlager, H.; Kleffmann, J.; Aufmhoff, H.; Schäuble, D.; Schaefer, M.; Schumann, U.

    2011-05-01

    Measurements of gaseous nitrogen and sulfur oxide emissions in young aircraft exhaust plumes give insight into chemical oxidation processes inside aircraft engines. Particularly, the OH-induced formation of nitrous acid (HONO) from nitrogen oxide (NO) and sulfuric acid (H2SO4) from sulfur dioxide (SO2) inside the turbine which is highly uncertain, need detailed analysis to address the climate impact of aviation. We report on airborne in situ measurements at cruise altitudes of HONO, NO, NOy, and SO2 in 9 wakes of 8 different types of modern jet airliners, including for the first time also an A380. Measurements of HONO and SO2 were made with an ITCIMS (Ion Trap Chemical Ionization Mass Spectrometer) using a new ion-reaction scheme involving SF5- reagent ions. The measured molar ratios HONO/NO and HONO/NOy with averages of 0.038 ± 0.010 and 0.027 ± 0.005 were found to decrease systematically with increasing NOx emission-index (EI NOx). We calculate an average EI HONO of 0.31 ± 0.12 g NO2 kg-1. Using reliable measurements of HONO and NOy, which are less adhesive than H2SO4 to the inlet walls, we derive the OH-induced conversion fraction of fuel sulfur to sulfuric acid $\\varepsilon$ with an average of 2.2 ± 0.5 %. $\\varepsilon$ also tends to decrease with increasing EI NOx, consistent with earlier model simulations. The lowest HONO/NO, HONO/NOy and $\\varepsilon$ was observed for the largest passenger aircraft A380.

  2. NOBLE GASES

    EPA Science Inventory

    The Noble Gases symposium, on which this report is based, provided comprehensive coverage of the noble gases. The coverage included, but was not limited to, the properties, biokinetics, bioeffects, production and release to the environment, detection techniques, standards, and ap...

  3. Two years of MAXDOAS measurements of NO2, HONO, SO2 and HCHO at SORPES station in Nanjing, China

    NASA Astrophysics Data System (ADS)

    Hao, Nan; Ding, Aijun; Van Roozendael, Michel; Hendrick, Francois; Shen, Yicheng; Valks, Pieter

    2015-04-01

    The Yangtze River Delta (YRD) region includes the mega-city Shanghai and the well-industrialized and urbanized areas of Zhejiang Province and Jiangsu Province, with over ten large cities, such as Hangzhou, Suzhou and Nanjing. Covering only 2% land area, this region produces over 20% of China's Gross Domestic Product (GDP) which makes it the most densely populated region and one of the most polluted regions in China. In the YRD region, knowledge gaps still exist in the understanding of the source and transport of air pollutants because only few measurement studies have been conducted. This work presents two years measurements of air pollutants including NO2, HONO, SO2, HCHO and CHOCHO at a regional back-ground site, the Station for Observing Regional Processes of the Earth System (SORPES), in the western part of the Yangtze River Delta (YRD) in eastern China. A retrieval algorithm, based on an on-line implementation of the radiative transfer code LIDORT and the optimal estimation technique, has been used to provide information on trace gases vertical profiles and vertical column densities (VCDs). The seasonal and diurnal cycles of trace gases have been studies and compared with in situ measurements. The retrieved tropospheric NO2, HCHO and SO2 VCDs were compared to satellite measurements, while the NO2 and SO2 near surface concentrations (0-200 m layer) were compared to measurements from in situ instruments at SORPES.

  4. Partitioning of HNO3, H2O2 and SO2 to cloud ice: Simulations with CMAQ

    NASA Astrophysics Data System (ADS)

    Marmo, Brain P.; Carlton, Annmarie G.; Henderson, Barron H.

    2014-05-01

    In the upper troposphere, gas phase species can partition to cloud ice, undergo chemical reaction and contribute to particle mass aloft, affecting chemical cycling in the atmosphere. This manuscript describes the first implementation of gas-to-cloud ice partitioning of three inorganic gases, HNO3, SO2 and H2O2, along with subsequent SO2 oxidation in the Community Multiscale Air Quality (CMAQ) chemical transport model. Four simulations are performed with CMAQv4.7.1 that include lightning production of NO for August 12th-25th of 2005 to investigate the impacts of ice chemistry on CMAQ-predicted gas phase mixing ratios and particle mass concentrations of associated species. Considerable episodic decreases, greater than 25%, in gas phase HNO3 are noted at pressures of 200-600 mb, with the largest changes at 300-400 mb. Effects are also induced on other gases in the nitrogen budget. NOx and HONO mixing ratios decrease up to 20%, but changes are generally less than 10%. Nitrate aerosol mass concentrations increase up to 0.15 μg m-3 for the highest model layers (100 mb). We find that phase changes in nitrogen species induced by ice partitioning are sensitive to CMAQ predictions of the aerosol phase accumulation mode ammonium to sulfate ratios [NH]:[SO]. Predicted O3 concentrations do not change (<1%). No changes in H2O2, SO2, or sulfate aerosol concentrations are observed.

  5. 40 CFR 97.220 - General CAIR SO2 Trading Program permit requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false General CAIR SO2 Trading Program... (CONTINUED) AIR PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS Permits § 97.220 General CAIR SO2 Trading Program permit requirements. (a) For each CAIR SO2...

  6. 40 CFR 97.286 - Withdrawal from CAIR SO2 Trading Program.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Withdrawal from CAIR SO2 Trading... PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS CAIR SO2 Opt-in Units § 97.286 Withdrawal from CAIR SO2 Trading Program. Except as provided under paragraph (g)...

  7. 40 CFR 96.286 - Withdrawal from CAIR SO2 Trading Program.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Withdrawal from CAIR SO2 Trading... PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR SO2 Opt-in Units § 96.286 Withdrawal from CAIR SO2 Trading Program. Except as...

  8. 40 CFR 97.625 - Compliance with TR SO2 Group 1 assurance provisions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Compliance with TR SO2 Group 1... TR SO2 Group 1 Trading Program § 97.625 Compliance with TR SO2 Group 1 assurance provisions. (a) Availability for deduction. TR SO2 Group 1 allowances are available to be deducted for compliance with the...

  9. 40 CFR 97.623 - Recordation of TR SO2 Group 1 allowance transfers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Recordation of TR SO2 Group 1... TR SO2 Group 1 Trading Program § 97.623 Recordation of TR SO2 Group 1 allowance transfers. (a) Within 5 business days (except as provided in paragraph (b) of this section) of receiving a TR SO2 Group...

  10. 40 CFR 97.711 - Timing requirements for TR SO2 Group 2 allowance allocations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Timing requirements for TR SO2 Group 2... TR SO2 Group 2 Trading Program § 97.711 Timing requirements for TR SO2 Group 2 allowance allocations. (a) Existing units. (1) TR SO2 Group 2 allowances are allocated, for the control periods in 2012...

  11. 40 CFR 97.722 - Submission of TR SO2 Group 2 allowance transfers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Submission of TR SO2 Group 2 allowance... PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS TR SO2 Group 2 Trading Program § 97.722 Submission of TR SO2 Group 2 allowance transfers. (a) An...

  12. 40 CFR 97.712 - TR SO2 Group 2 allowance allocations to new units.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false TR SO2 Group 2 allowance allocations... TR SO2 Group 2 Trading Program § 97.712 TR SO2 Group 2 allowance allocations to new units. (a) For each control period in 2012 and thereafter and for the TR SO2 Group 2 units in each State,...

  13. 40 CFR 97.711 - Timing requirements for TR SO2 Group 2 allowance allocations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Timing requirements for TR SO2 Group 2... TR SO2 Group 2 Trading Program § 97.711 Timing requirements for TR SO2 Group 2 allowance allocations. (a) Existing units. (1) TR SO2 Group 2 allowances are allocated, for the control periods in 2012...

  14. 40 CFR 97.611 - Timing requirements for TR SO2 Group 1 allowance allocations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Timing requirements for TR SO2 Group 1... TR SO2 Group 1 Trading Program § 97.611 Timing requirements for TR SO2 Group 1 allowance allocations. (a) Existing units. (1) TR SO2 Group 1 allowances are allocated, for the control periods in 2012...

  15. 40 CFR 97.725 - Compliance with TR SO2 Group 2 assurance provisions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Compliance with TR SO2 Group 2... TR SO2 Group 2 Trading Program § 97.725 Compliance with TR SO2 Group 2 assurance provisions. (a) Availability for deduction. TR SO2 Group 2 allowances are available to be deducted for compliance with the...

  16. 40 CFR 97.712 - TR SO2 Group 2 allowance allocations to new units.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false TR SO2 Group 2 allowance allocations... TR SO2 Group 2 Trading Program § 97.712 TR SO2 Group 2 allowance allocations to new units. (a) For each control period in 2012 and thereafter and for the TR SO2 Group 2 units in each State,...

  17. 40 CFR 97.725 - Compliance with TR SO2 Group 2 assurance provisions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Compliance with TR SO2 Group 2... TR SO2 Group 2 Trading Program § 97.725 Compliance with TR SO2 Group 2 assurance provisions. (a) Availability for deduction. TR SO2 Group 2 allowances are available to be deducted for compliance with the...

  18. 40 CFR 97.625 - Compliance with TR SO2 Group 1 assurance provisions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Compliance with TR SO2 Group 1... TR SO2 Group 1 Trading Program § 97.625 Compliance with TR SO2 Group 1 assurance provisions. (a) Availability for deduction. TR SO2 Group 1 allowances are available to be deducted for compliance with the...

  19. 40 CFR 97.724 - Compliance with TR SO2 Group 2 emissions limitation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Compliance with TR SO2 Group 2... TR SO2 Group 2 Trading Program § 97.724 Compliance with TR SO2 Group 2 emissions limitation. (a) Availability for deduction for compliance. TR SO2 Group 2 allowances are available to be deducted...

  20. 40 CFR 97.622 - Submission of TR SO2 Group 1 allowance transfers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Submission of TR SO2 Group 1 allowance... PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS TR SO2 Group 1 Trading Program § 97.622 Submission of TR SO2 Group 1 allowance transfers. (a) An...

  1. 40 CFR 97.624 - Compliance with TR SO2 Group 1 emissions limitation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Compliance with TR SO2 Group 1... TR SO2 Group 1 Trading Program § 97.624 Compliance with TR SO2 Group 1 emissions limitation. (a) Availability for deduction for compliance. TR SO2 Group 1 allowances are available to be deducted...

  2. 40 CFR 97.722 - Submission of TR SO2 Group 2 allowance transfers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Submission of TR SO2 Group 2 allowance... PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS TR SO2 Group 2 Trading Program § 97.722 Submission of TR SO2 Group 2 allowance transfers. (a) An...

  3. 40 CFR 97.623 - Recordation of TR SO2 Group 1 allowance transfers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Recordation of TR SO2 Group 1... TR SO2 Group 1 Trading Program § 97.623 Recordation of TR SO2 Group 1 allowance transfers. (a) Within 5 business days (except as provided in paragraph (b) of this section) of receiving a TR SO2 Group...

  4. 40 CFR 97.624 - Compliance with TR SO2 Group 1 emissions limitation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Compliance with TR SO2 Group 1... TR SO2 Group 1 Trading Program § 97.624 Compliance with TR SO2 Group 1 emissions limitation. (a) Availability for deduction for compliance. TR SO2 Group 1 allowances are available to be deducted...

  5. 40 CFR 97.611 - Timing requirements for TR SO2 Group 1 allowance allocations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Timing requirements for TR SO2 Group 1... TR SO2 Group 1 Trading Program § 97.611 Timing requirements for TR SO2 Group 1 allowance allocations. (a) Existing units. (1) TR SO2 Group 1 allowances are allocated, for the control periods in 2012...

  6. 40 CFR 97.623 - Recordation of TR SO2 Group 1 allowance transfers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Recordation of TR SO2 Group 1... TR SO2 Group 1 Trading Program § 97.623 Recordation of TR SO2 Group 1 allowance transfers. (a) Within 5 business days (except as provided in paragraph (b) of this section) of receiving a TR SO2 Group...

  7. 40 CFR 97.625 - Compliance with TR SO2 Group 1 assurance provisions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Compliance with TR SO2 Group 1... TR SO2 Group 1 Trading Program § 97.625 Compliance with TR SO2 Group 1 assurance provisions. (a) Availability for deduction. TR SO2 Group 1 allowances are available to be deducted for compliance with the...

  8. 40 CFR 97.724 - Compliance with TR SO2 Group 2 emissions limitation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Compliance with TR SO2 Group 2... TR SO2 Group 2 Trading Program § 97.724 Compliance with TR SO2 Group 2 emissions limitation. (a) Availability for deduction for compliance. TR SO2 Group 2 allowances are available to be deducted...

  9. 40 CFR 97.622 - Submission of TR SO2 Group 1 allowance transfers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Submission of TR SO2 Group 1 allowance... PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS TR SO2 Group 1 Trading Program § 97.622 Submission of TR SO2 Group 1 allowance transfers. (a) An...

  10. 40 CFR 97.725 - Compliance with TR SO2 Group 2 assurance provisions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Compliance with TR SO2 Group 2... TR SO2 Group 2 Trading Program § 97.725 Compliance with TR SO2 Group 2 assurance provisions. (a) Availability for deduction. TR SO2 Group 2 allowances are available to be deducted for compliance with the...

  11. 40 CFR 97.624 - Compliance with TR SO2 Group 1 emissions limitation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Compliance with TR SO2 Group 1... TR SO2 Group 1 Trading Program § 97.624 Compliance with TR SO2 Group 1 emissions limitation. (a) Availability for deduction for compliance. TR SO2 Group 1 allowances are available to be deducted...

  12. 40 CFR 97.723 - Recordation of TR SO2 Group 2 allowance transfers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Recordation of TR SO2 Group 2... TR SO2 Group 2 Trading Program § 97.723 Recordation of TR SO2 Group 2 allowance transfers. (a) Within 5 business days (except as provided in paragraph (b) of this section) of receiving a TR SO2 Group...

  13. 40 CFR 97.711 - Timing requirements for TR SO2 Group 2 allowance allocations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Timing requirements for TR SO2 Group 2... TR SO2 Group 2 Trading Program § 97.711 Timing requirements for TR SO2 Group 2 allowance allocations. (a) Existing units. (1) TR SO2 Group 2 allowances are allocated, for the control periods in 2012...

  14. 40 CFR 97.724 - Compliance with TR SO2 Group 2 emissions limitation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Compliance with TR SO2 Group 2... TR SO2 Group 2 Trading Program § 97.724 Compliance with TR SO2 Group 2 emissions limitation. (a) Availability for deduction for compliance. TR SO2 Group 2 allowances are available to be deducted...

  15. 40 CFR 97.723 - Recordation of TR SO2 Group 2 allowance transfers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Recordation of TR SO2 Group 2... TR SO2 Group 2 Trading Program § 97.723 Recordation of TR SO2 Group 2 allowance transfers. (a) Within 5 business days (except as provided in paragraph (b) of this section) of receiving a TR SO2 Group...

  16. 40 CFR 97.722 - Submission of TR SO2 Group 2 allowance transfers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Submission of TR SO2 Group 2 allowance... PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS TR SO2 Group 2 Trading Program § 97.722 Submission of TR SO2 Group 2 allowance transfers. (a) An...

  17. 40 CFR 97.612 - TR SO2 Group 1 allowance allocations to new units.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false TR SO2 Group 1 allowance allocations... TR SO2 Group 1 Trading Program § 97.612 TR SO2 Group 1 allowance allocations to new units. (a) For each control period in 2012 and thereafter and for the TR SO2 Group 1 units in each State,...

  18. 40 CFR 97.611 - Timing requirements for TR SO2 Group 1 allowance allocations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Timing requirements for TR SO2 Group 1... TR SO2 Group 1 Trading Program § 97.611 Timing requirements for TR SO2 Group 1 allowance allocations. (a) Existing units. (1) TR SO2 Group 1 allowances are allocated, for the control periods in 2012...

  19. 40 CFR 97.612 - TR SO2 Group 1 allowance allocations to new units.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false TR SO2 Group 1 allowance allocations... TR SO2 Group 1 Trading Program § 97.612 TR SO2 Group 1 allowance allocations to new units. (a) For each control period in 2012 and thereafter and for the TR SO2 Group 1 units in each State,...

  20. 40 CFR 97.712 - TR SO2 Group 2 allowance allocations to new units.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false TR SO2 Group 2 allowance allocations... TR SO2 Group 2 Trading Program § 97.712 TR SO2 Group 2 allowance allocations to new units. (a) For each control period in 2012 and thereafter and for the TR SO2 Group 2 units in each State,...

  1. 40 CFR 97.723 - Recordation of TR SO2 Group 2 allowance transfers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Recordation of TR SO2 Group 2... TR SO2 Group 2 Trading Program § 97.723 Recordation of TR SO2 Group 2 allowance transfers. (a) Within 5 business days (except as provided in paragraph (b) of this section) of receiving a TR SO2 Group...

  2. 40 CFR 97.612 - TR SO2 Group 1 allowance allocations to new units.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false TR SO2 Group 1 allowance allocations... TR SO2 Group 1 Trading Program § 97.612 TR SO2 Group 1 allowance allocations to new units. (a) For each control period in 2012 and thereafter and for the TR SO2 Group 1 units in each State,...

  3. 40 CFR 97.622 - Submission of TR SO2 Group 1 allowance transfers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Submission of TR SO2 Group 1 allowance... PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS TR SO2 Group 1 Trading Program § 97.622 Submission of TR SO2 Group 1 allowance transfers. (a) An...

  4. 40 CFR 97.286 - Withdrawal from CAIR SO2 Trading Program.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Withdrawal from CAIR SO2 Trading... PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS CAIR SO2 Opt-in Units § 97.286 Withdrawal from CAIR SO2 Trading Program. Except as provided under paragraph (g)...

  5. 40 CFR 96.286 - Withdrawal from CAIR SO2 Trading Program.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Withdrawal from CAIR SO2 Trading... PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR SO2 Opt-in Units § 96.286 Withdrawal from CAIR SO2 Trading Program. Except as...

  6. 40 CFR 96.286 - Withdrawal from CAIR SO2 Trading Program.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Withdrawal from CAIR SO2 Trading... PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR SO2 Opt-in Units § 96.286 Withdrawal from CAIR SO2 Trading Program. Except as...

  7. 40 CFR 96.286 - Withdrawal from CAIR SO 2 Trading Program.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Withdrawal from CAIR SO 2 Trading... PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO 2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR SO 2 Opt-in Units § 96.286 Withdrawal from CAIR SO 2 Trading Program. Except...

  8. 40 CFR 96.254 - Compliance with CAIR SO2 emissions limitation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR SO2 Allowance Tracking System § 96.254 Compliance with CAIR SO2 emissions limitation... Administrator may review and conduct independent audits concerning any submission under the CAIR SO2...

  9. 40 CFR 97.286 - Withdrawal from CAIR SO2 Trading Program.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Withdrawal from CAIR SO2 Trading... PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS CAIR SO2 Opt-in Units § 97.286 Withdrawal from CAIR SO2 Trading Program. Except as provided under paragraph (g)...

  10. 40 CFR 96.286 - Withdrawal from CAIR SO 2 Trading Program.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Withdrawal from CAIR SO 2 Trading... PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR SO 2 Opt-in Units § 96.286 Withdrawal from CAIR SO 2 Trading Program. Except...

  11. 40 CFR 97.286 - Withdrawal from CAIR SO2 Trading Program.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Withdrawal from CAIR SO2 Trading... PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS CAIR SO2 Opt-in Units § 97.286 Withdrawal from CAIR SO2 Trading Program. Except as provided under paragraph (g)...

  12. 40 CFR 97.286 - Withdrawal from CAIR SO2 Trading Program.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Withdrawal from CAIR SO2 Trading... PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS CAIR SO2 Opt-in Units § 97.286 Withdrawal from CAIR SO2 Trading Program. Except as provided under paragraph (g)...

  13. 40 CFR 60.4330 - What emission limits must I meet for sulfur dioxide (SO2)?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... sulfur dioxide (SO2)? 60.4330 Section 60.4330 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... sulfur dioxide (SO2)? (a) If your turbine is located in a continental area, you must comply with either... contains total potential sulfur emissions in excess of 26 ng SO2/J (0.060 lb SO2/MMBtu) heat input. If...

  14. 40 CFR 60.4330 - What emission limits must I meet for sulfur dioxide (SO2)?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... sulfur dioxide (SO2)? 60.4330 Section 60.4330 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... sulfur dioxide (SO2)? (a) If your turbine is located in a continental area, you must comply with either... contains total potential sulfur emissions in excess of 26 ng SO2/J (0.060 lb SO2/MMBtu) heat input. If...

  15. 40 CFR 60.4330 - What emission limits must I meet for sulfur dioxide (SO2)?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... sulfur dioxide (SO2)? 60.4330 Section 60.4330 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... sulfur dioxide (SO2)? (a) If your turbine is located in a continental area, you must comply with either... contains total potential sulfur emissions in excess of 26 ng SO2/J (0.060 lb SO2/MMBtu) heat input. If...

  16. Water droplets and ice retrievals in volcanic clouds using multispectral TIR satellite data. Correction procedure for SO2 estimation

    NASA Astrophysics Data System (ADS)

    Corradini, Stefano; Guerrieri, Lorenzo; Merucci, Luca; Pugnaghi, Sergio; Salerno, Giuseppe

    2015-04-01

    Among ash and gases, the volcanic clouds generated from several 2011-2014 Etna (Italy) lava fountains, were characterized by the huge presence of water droplets (wd) and/or ice. In some cases the wd/ice presence totally masked the ash signal and always significantly influenced the SO2 retrievals. Here the MODIS multispectral measurements are used to retrieve the volcanic wd and ice particles by means of two different techniques based on BTD (Brightness Temperature Difference) algorithm and VPR (Volcanic Plume Removal) approach. As test case the MODIS-Aqua images collected on Etna volcano the 10 April 2011 at 12:30 UTC and the 12 August 2011 at 11:15 UTC have been considered. Similarly to volcanic ashes, the wd/ice particles reduce the top of atmosphere radiance in the entire TIR spectral range, including the channels used for the SO2 retrieval. The net effect is a significant SO2 overestimation. Here two procedures for the correction of the wd/ice influence on SO2 retrieval are proposed. The results obtained from the MODIS 10 April 2011 MODIS image have been compared with the measurements collected by the FLAME ground-based network of DOAS instruments deployed on Mt. Etna.

  17. Broadband UV spectroscopy system used for monitoring of SO 2 and NO emissions from thermal power plants

    NASA Astrophysics Data System (ADS)

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

    2010-11-01

    A gas monitoring system based on broadband absorption spectroscopic techniques in the ultraviolet region is described and tested. The system was employed in real-time continuous concentration measurements of sulfur dioxide (SO 2) and nitric oxide (NO) from a 220-ton h -1 circulating fluidized bed (CFB) boiler in Shandong province, China. The emission coefficients (per kg of coal and per kWh of electricity) and the total emission of the two pollutant gases were evaluated. The measurement results showed that the emission concentrations of SO 2 and NO from the CFB boiler fluctuated in the range of 750-1300 mg m -3 and 100-220 mg m -3, respectively. Compared with the specified emission standards of air pollutants from thermal power plants in China, the values were generally higher for SO 2 and lower for NO. The relatively high emission concentrations of SO 2 were found to mainly depend on the sulfur content of the fuel and the poor desulfurization efficiency. This study indicates that the broadband UV spectroscopy system is suitable for industrial emission monitoring and pollution control.

  18. Determining the CH3SO2 --> CH3 + SO2 barrier from methylsulfonyl chloride photodissociation at 193 nm using velocity map imaging.

    PubMed

    Ratliff, Britni J; Tang, Xiaonan; Butler, Laurie J; Szpunar, David E; Lau, Kai-Chung

    2009-07-28

    These imaging experiments study the formation of the methylsulfonyl radical, CH(3)SO(2), from the photodissociation of CH(3)SO(2)Cl at 193 nm and determine the energetic barrier for the radical's subsequent dissociation to CH(3) + SO(2). We first state-selectively detect the angular and recoil velocity distributions of the Cl((2)P(3/2)) and Cl((2)P(1/2)) atoms to further refine the distribution of internal energy partitioned to the momentum-matched CH(3)SO(2) radicals. The internal energy distribution of the radicals is bimodal, indicating that CH(3)SO(2) is formed in both the ground state and low-lying excited electronic states. All electronically excited CH(3)SO(2) radicals dissociate, while those formed in the ground electronic state have an internal energy distribution which spans the dissociation barrier to CH(3) + SO(2). We detect the recoil velocities of the energetically stable methylsulfonyl radicals with 118 nm photoionization. Comparison of the total recoil translational energy distribution for all radicals to the distribution obtained from the detection of stable radicals yields an onset for dissociation at a translational energy of 70+/-2 kcal/mol. This onset allows us to derive a CH(3)SO(2) --> CH(3) + SO(2) barrier height of 14+/-2 kcal/mol; this determination relies on the S-Cl bond dissociation energy, taken here as the CCSD(T) predicted energy of 65.6 kcal/mol. With 118 nm photoionization, we also detect the velocity distribution of the CH(3) radicals produced in this experiment. Using the velocity distributions of the SO(2) products from the dissociation of CH(3)SO(2) to CH(3) + SO(2) presented in the following paper, we show that our fastest detected methyl radicals are not from these radical dissociation channels, but rather from a primary S-CH(3) bond photofission channel in CH(3)SO(2)Cl. We also present critical points on the ground state potential energy surface of CH(3)SO(2) at the //CCSD(T)/aug-cc-pV(Q + d)ZCCSD(T)/6-311++G(2df,p) level

  19. Oxidation of SO2 and formation of water droplets under irradiation of 20 MeV protons in N2/H2O/SO2

    NASA Astrophysics Data System (ADS)

    Tomita, Shigeo; Nakai, Yoichi; Funada, Shuhei; Tanikawa, Hideomi; Harayama, Isao; Kobara, Hitomi; Sasa, Kimikazu; Pedersen, Jens Olaf Pepke; Hvelplund, Preben

    2015-12-01

    We have performed an experiment on charged droplet formation in a humidified N2 gas with trace SO2 concentration and induced by 20 MeV proton irradiation. It is thought that SO2 reacts with the chemical species, such as OH radicals, generated through the reactions triggered by N2+ production. Both droplet number and droplet size increased with SO2 consumption for the proton irradiation. The total charged droplet numbers entering the differential mobility analyzer per unit time were proportional to the 0.68 power of the SO2 consumption. These two findings suggest that coagulation among the small droplets contributes to the formation of the droplets. The charged droplet volume detected per unit time is proportional to the SO2 consumption, which indicates that a constant amount of sulfur atoms is contained in a unit volume of droplet, regardless of different droplet-size distributions depending on the SO2 consumption.

  20. Optimal spectral resolution for NO2 and SO2 retrieval by Geostationary Environmental Monitoring Spectrometer (GEMS)

    NASA Astrophysics Data System (ADS)

    Chong, J.; Kim, Y. J.; Scientific Team of DOAS

    2011-12-01

    Ministry of Environment, Korea is planning an environmental geostationary satellite program as a part of MP-GEOSAT (Multi-Purpose GEOstationary SATellite), which is scheduled to be launched in 2017 (Lee S. et al., 2010). It is supposed to be placed on an orbit of approximately 36,000 kilometers high directly over the equator, which revolves in the same direction the earth rotates. Its missions include meteorological, ocean monitoring, and environmental monitoring. Especially, Geostationary Environmental Monitoring Spectrometer (GEMS) is to provide atmospheric chemistry measurements of trace gases such as O3, NO2, SO2, HCHO, and aerosol in high temporal (every 1 hour) and spatial (30x30 km2) resolution over Asia, to monitor regional transport events such as transboundary pollution and Asian dust, and to enhance our understanding on interactions between atmospheric chemistry and meteorology. In order to determine the minimum required spectral resolution of GEMS, measurement accuracy has been estimated for different spectral resolutions based on the actual satellite data as well as model simulation data of very fine spectral resolution. Absorption spectra of SCIAMACHY level 2 data (http://www.temis.nl) with spectral resolution of 0.2nm and reconstructed spectra of broader spectral resolution; 0.4, 0.6, and 0.8nm have been utilized to assess the applicability for SO2 and NO2 retrievals over GEMS spatial coverage areas using the DOAS fitting method. The relative fitting error in SO2 retrieval of each spectral resolution over southern China was determined to be 45.1, 56.1, 99.7, and 187.3 %, respectively. The relative fitting errors in NO2 retrieval of each spectral resolution over northern India were 16.2, 24.6, 32.6, and 38.9 %, respectively. Since relative fitting error in SO2 retrieval increases as the spectra resolution increases, the optimal spectrum resolution was determined to be 0.4nm. On the other hand, since the relative fitting error in NO2 retrieval is below

  1. [Analysis About Spatial and Temporal Distribution of SO2 and An Ambient SO2 Pollution Process in Beijing During 2000-2014].

    PubMed

    Cheng, Nian-liang; Zhang, Da-wei; Li, Yun-ting; Chen, Tian; Li, Jin-xiang; Dong, Xin; Sun, Rui-wen; Meng, Fan

    2015-11-01

    Spatial and temporal distribution of SO2 during 2000-2014 was all analyzed based on the SO2 monitoring data that Beijing Municipal Environmental Monitoring Center released and the formation mechanism of a typical air pollution episode in January 2014 was also investigated by combining numerical model CAM(x). Analysis results showed that mass concentration of ρ(SO2) in Beijing in 2014 decreased 69% compared to that in 2000 with an annual gradient from 2000 to 2014 of - 3.5 μg x (m3 x a)(-1). Monthly average concentration of SO2 changed in a U shape curve and from the lowest to the highest, and seasonal variations of SO2 concentrations were as follows: winter > spring > autumn > summer; concentration of SO2 in heating season was significantly higher than that in non heating season. Annual average concentration of SO2 was lower in northern and western regions while higher in six city area and southern area. Concentrations of SO2 at Shijingshan, Dongsi, Tongzhou monitoring sites were significantly decreased related to SO2 emission reduction measures. During a heavy air pollution process in January 14 - 18th 2014 there was obviously SO2 regional transportation and model simulation analysis based on PAST showed that the contribution of SO2 regional transport to Beijing was 83% with elevated power plants surrounding Beijing accounting for 21% and the four major Beijing power plants contributing about 3.5% to the SO2 concentration during this heavy air pollution process. PMID:26910979

  2. COMPARISON OF THE 1985 NAPAP EMISSIONS INVENTORY WITH THE 1985 EPA TRENDS ESTIMATE FOR INDUSTRIAL SO2 SOURCES

    EPA Science Inventory

    The report gives results of analysis of 1985 industrial sulfur dioxide (SO2) emissions from two data sources: the National Acid Precipitation Assessment Program (NAPAP) inventory and the EPA TRENDS report. These analyses conclude that the two data sources estimate comparable emis...

  3. Canopy stomatal uptake of NOX, SO2 and O3 by mature urban plantations based on sap flow measurement

    NASA Astrophysics Data System (ADS)

    Hu, Yanting; Zhao, Ping; Niu, Junfeng; Sun, Zhenwei; Zhu, Liwei; Ni, Guangyan

    2016-01-01

    Canopy stomatal uptake of NOX (NO, NO2), SO2 and O3 by three mature urban plantations (of Schima superba, Eucalyptus citriodora and Acacia auriculaeformis) were studied using the sap flow-based approach under free atmospheric conditions. The annual mean concentration for NO, NO2, SO2 and O3 were 18.2, 58.1, 12.8 and 42.4 μg m-3, respectively. The atmospheric concentration exhibited a spring or winter maximum for NO, NO2 and SO2, whereas the concentration maximum for O3 occurred in the autumn. Despite the daytime mean canopy stomatal conductance (GC) being positively related with the photosynthetically active radiation (PAR) and negatively with the vapour pressure deficit (VPD), the maximal daytime mean GC did not appear when the PAR was at its highest level or the VPD was at its lowest level because a positive correlation was noted between the daytime mean PAR and VPD (P < 0.001) under field conditions. The GC value was regulated by the cooperation of the PAR and VPD. When analysing the respective effect of the PAR or VPD on GC separately, a positive logarithmical correlation was noted between the daytime mean GC and PAR as the following equation:Gc = a × lnPAR - b (P < 0.01), and the daytime mean GC was negatively logarithmically correlated with the VPD: Gc =Gsref - m × lnVPD (P < 0.001). The daytime mean GC declined with decreases in the soil water content (SWC) under similar meteorological condition. Differences in the seasonal pattern of the canopy stomatal conductance and atmospheric concentrations led to a differentiated peak flux. The flux for NO, NO2 and SO2 exhibited a spring maximum, whereas the flux maximum for O3 appeared in the autumn or summer. The annual cumulative stomatal flux for NO, NO2, O3 and SO2 was 100.19 ± 3.76, 510.68 ± 24.78, 748.59 ± 52.81 and 151.98 ± 9.33 mg m-2 a-1, respectively. When we focus on the foliar uptake of trace gases, the effect of these gases on the vegetation in turn should be considered, particularly for regions

  4. MAX-DOAS measurements of tropospheric NO2 and SO2 during the AROMAT-campaign in Rumania in September 2014

    NASA Astrophysics Data System (ADS)

    Shaiganfar, Reza; Wagner, Thomas; Riffel, Katharina; Donner, Sebastian

    2015-04-01

    The Airborne Romanian Measurements of Aerosols and Trace gases (AROMAT) campaigh took place in Rumania during September 2014. The aim of the AROMAT campaign was to measure the spatial distribution of trace gases (mainly NO2 and SO2) and aerosols. We carried out car-borne Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements using two Mini-MAX-DOAS instruments covering the UV and visible spectral range. During the first week car-MAX-DOAS measurements were carried-out on circles around Bucharest. From these observations, together with information on the wind fields, we derive the total NOx emissions from the city. We also provide estimates on the SO2 emissions, but these estimates have rather large uncertainties because the SO2 measurements are close or below the detection limit. We also made measurements within the city to quantify the spatial gradients. This information is especially important for the validation of satellite observations. In the second week, the car-MAX-DOAS measurements were carried-out around large power plants at Turceni. During these measurements, very strong SO2 absorptions were observed downwind of the power plants. From these observations, we estimate the SO2 emissions. We also determine the NO2 / SO2 ratio and investigate its dependence on the distance from the power plant.

  5. SORPTION OF MERCURY SPECIES BY ACTIVATED CARBONS AND CALCIUM-BASES SORBENTS: EFFECT OF TEMPERATURE, MERCURY CONCENTRATION AND ACID GASES

    EPA Science Inventory

    Bench-scale studies of mercury/sorbent reactions were conducted to understand mechanistic limitations of field-scale attempts to reduce emissions of mercury from combustion processes. The effects of temperature (60 - 140 degrees C), sulfur dioxide (SO2, 1000 ppm ), hydrogen chlor...

  6. Novel process for simultaneous removal of NO(x) and SO2 from simulated flue gas by using a sustainable Ag(I)/Ag(II) redox mediator.

    PubMed

    Raju, Thasan; Chung, Sang Joon; Moon, Il Shik

    2008-10-01

    The objective of this work is to develop a sustainable process for simultaneous removal of waste gases such as NO, NO2, and SO2 by an electrochemically generated Ag(I)/Ag(II) redox mediator system. High removal efficiency was achieved for NO and SO2 by the wet scrubbing method at room temperature and atmospheric pressure. This removal is achieved through oxidation and absorption by contacting the gaseous stream with redox mediator ions that offer specific or selective solubility for the solute gases to be recovered in a wet scrubber. The process parameters such as gas velocity, liquid velocity, Ag(I) concentration, and HNO3 concentration were investigated to explore the possibility of complete removal of waste gases. The Ag(I)/Ag(II)-based mediated electrochemical oxidation process proved to be quite effective for simultaneous removal of NO, NO(x), and SO2 from the simulated flue gas mixtures containing NO and SO2 over a wide concentration range of 100-400 ppm. Studies were carried out with individual gas components for the mixture, and the effect of input NO and input SO2 concentrations on the NO(x) and SO2 removal efficiencies at 20 degrees C was examined. Complete oxidation of NO to NO2 with 100% NO removal efficiency and 92% NO(x) removal efficiency was achieved along with 100% SO2 removal efficiency, highlighting a potentially far greater efficiency of the Ag(I)/Ag(II)-based system in functionality and selectivity. Active research work in this direction is anticipated in the near future. PMID:18939587

  7. PROCEEDINGS: JOINT SYMPOSIUM ON DRY SO2 AND SIMULTANEOUS SO2/NOX CONTROL TECHNOLOGIES (1ST): VOLUME 2. POWER PLANT INTEGRATION, ECONOMICS, AND FULL-SCALE EXPERIENCE

    EPA Science Inventory

    The proceedings document the First Joint Symposium on Dry SO2 and Simultaneous SO2/NOx Control Technologies, held November 13-16, 1984, in San Diego, CA. The symposium, sponsored jointly by EPRI and EPA, was the first meeting of its kind devoted solely to the discussion of emissi...

  8. Transport of gaseous NO2 and SO2 by MAX-DOAS in Beijing and surrounding area

    NASA Astrophysics Data System (ADS)

    Xu, Jin; Li, Ang; Xie, Pinhua; Liu, Jianguo; Liu, Wenqing

    2016-04-01

    With the development of industry and urbanization, regional pollution is increasing seriously, and the cross influence between cities is becoming more frequently. Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) has been successfully applied in the remote sensing of gaseous pollutants during the past decade, it is based on scattered light of the sun, and can measure spectral in different directions, measure tropospheric and the whole atmospheric column densities of trace gases combining with radiative transfer model (RTM). This approach is very useful for the investigation of the main path of air pollution transportation. Fifteen MAX-DOAS stations which are in urban and in the path of pollution transport are set up in Beijing and surrounding area including Tianjin and Hebei province to observe the spatial and temporal distributions and regional transport of gaseous NO2 and SO2. The NO2 VCDs and profiles and SO2 VCDs are obtained. The results show that the NO2 column densities in urban are higher than surroundings, it shows that the NO2 in Beijing is mainly from the local; The SO2 column densities in other cities to the south of Beijing are obviously higher than in Beijing, so regional transport from the south of Hebei province will have a significant impact on Beijing. From the results of NO2 and SO2, the whole pollution process including incubation, generation, duration, and dispersion was observed. The vertical distribution show that NO2 concentration is mainly near the surface from 0 to 400m, and SO2 is higher in the transport process.

  9. Simultaneous removal of SO2 and trace SeO2 from flue gas: effect of SO2 on selenium capture and kinetics study.

    PubMed

    Li, Yuzhong; Tong, Huiling; Zhuo, Yuqun; Wang, Shujuan; Xu, Xuchang

    2006-12-15

    Sulfur dioxide (SO2) and trace elements are all pollutants derived from coal combustion. This study relates to the simultaneous removal of SO2 and trace selenium dioxide (SeO2) from flue gas by calcium oxide (CaO) adsorption in the moderate temperature range, especially the effect of SO2 presence on selenium capture. Experiments performed on a thermogravimetric analyzer (TGA) can reach the following conclusions. When the CaO conversion is relatively low and the reaction rate is controlled by chemical kinetics, the SO2 presence does not affect the selenium capture. When the CaO conversion is very high and the reaction rate is controlled by product layer diffusion, the SO2 presence and the product layer diffusion resistance jointly reduce the selenium capture. On the basis of the kinetics study, a method to estimate the trace selenium removal efficiency using kinetic parameters and the sulfur removal efficiency is developed. PMID:17256549

  10. Infrared absorption of CH3SO2 observed upon irradiation of a p-H2 matrix containing CH3I and SO2

    NASA Astrophysics Data System (ADS)

    Lee, Yu-Fang; Lee, Yuan-Pern

    2011-03-01

    Irradiation with a mercury lamp at 254 nm of a p-H2 matrix containing CH3I and SO2 at 3.3 K, followed by annealing of the matrix, produced prominent features at 633.8, 917.5, 1071.1 (1072.2), 1272.5 (1273.0, 1273.6), and 1416.0 cm-1, attributable to ν11 (C-S stretching), ν10 (CH3 wagging), ν8 (SO2 symmetric stretching), ν7 (SO2 antisymmetric stretching), and ν4 (CH2 scissoring) modes of methylsulfonyl radical (CH3SO2), respectively; lines listed in parentheses are weaker lines likely associated with species in a different matrix environment. Further irradiation at 365 nm diminishes these features and produced SO2 and CH3. Additional features at 1150.1 and 1353.1 (1352.7) cm-1 are tentatively assigned to the SO2 symmetric and antisymmetric stretching modes of ISO2. These assignments are based on comparison of observed vibrational wavenumbers and 18O- and 34S-isotopic shifts with those predicted with the B3P86 method. Our results agree with the previous report of transient IR absorption bands of gaseous CH3SO2 at 1280 and 1076 cm-1. These results demonstrate that the cage effect of solid p-H2 is diminished so that CH3 radicals, produced via UV photodissociation of CH3I in situ, might react with SO2 to form CH3SO2 during irradiation and upon annealing. Observation of CH3SO2 but not CH3OSO is consistent with the theoretical predictions that only the former reactions proceed via a barrierless path.

  11. Adsorption of SO2 and NO from incineration flue gas onto activated carbon fibers.

    PubMed

    Liu, Zhen-Shu

    2008-11-01

    Activated carbon fibers (ACFs) were used to remove SO2 and NO from incineration flue gas. Three types of ACFs in their origin state and after pretreatment with HNO3, NaOH, and KOH were investigated. The removal efficiencies of SO2 and NO were determined experimentally at defined SO2 and NO concentrations and at temperatures of 150, 200 and 260 degrees C. Experimental results indicated that the removal efficiencies of SO2 and NO using the original ACFs were < 56% and < 27%, respectively. All ACFs modified with HNO3, NaOH, and KOH solution could increase the removal efficiencies of SO(2) and NO. The mesopore volumes and functional groups of ACFs are important in determining the removal of SO2 and NO. When the mesopore volumes of the ACFs are insufficient for removing SO2 and NO, the functional groups on the ACFs are not important in determining the removal of SO2 and NO. On the contrary, the effects of the functional groups on the removal of SO2 and NO are more important than the mesopore volumes as the amount of mesopores on the ACFs is sufficient to remove SO2 and NO. Moreover, the removal efficiencies of SO2 and NO were greatest at 200 degrees C. When the inlet concentration of SO2 increased to 600 ppm, the removal efficiency of SO2 increased slightly and the removal efficiency of NO decreased. PMID:18083361

  12. 40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... discharged into the atmosphere from the affected facility any gases that contain mercury in excess of the... potential mercury emission concentration (85-percent reduction by weight), corrected to 7 percent oxygen... percent of the potential mercury emission concentration (85-percent reduction by weight), corrected to...

  13. 40 CFR 62.14103 - Emission limits for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... operator of an affected facility must not cause to be discharged into the atmosphere from that affected... operator of an affected facility must not cause to be discharged into the atmosphere from that affected... discharged into the atmosphere from that affected facility any gases that contain mercury in excess of...

  14. 40 CFR 62.14103 - Emission limits for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... operator of an affected facility must not cause to be discharged into the atmosphere from that affected... operator of an affected facility must not cause to be discharged into the atmosphere from that affected... discharged into the atmosphere from that affected facility any gases that contain mercury in excess of...

  15. Reactions of acetone oxide stabilized Criegee intermediate with SO2, NO2, H2O and O3

    NASA Astrophysics Data System (ADS)

    Kukui, Alexandre; Chen, Hui; Xiao, Shan; Mellouki, Wahid; Daële, Veronique

    2015-04-01

    Atmospheric aerosol particles represent a critical component of the atmosphere, impacting global climate, regional air pollution, and human health. The formation of new atmospheric particles and their subsequent growth to larger sizes are the key processes for understanding of the aerosol effects. Sulphuric acid, H2SO4, has been identified to play the major role in formation of new atmospheric particles and in subsequent particle growth. Until recently the reaction of OH with SO2 has been considered as the only important source of H2SO4 in the atmosphere. However, recently it has been suggested that the oxidation of SO2 by Criegee biradicals can be a significant additional atmospheric source of H2SO4 comparable with the reaction of SO2 with OH. Here we present some results about the reactions of the acetone oxide stabilized Criegee intermediate, (CH3)2=OO, produced in the reaction of 2,3-dimethyl-butene (TME) with O3. The formation of the H2SO4 in the reaction of acetone oxide with SO2 was investigated in the specially constructed atmospheric pressure laminar flow reactor. The Criegee intermediate was generated by ozonolysis of TME. The H2SO4, generated by addition of SO2, was directly monitored with Chemical Ionization Mass Spectrometer (SAMU, LPC2E). Relative rates of reactions of acetone oxide with SO2, NO2, H2O and ozone were determined from the dependencies of the H2SO4 yield at different concentrations of the reactants. Atmospheric applications of the obtained results are discussed in relation to the importance of this additional H2SO4 formation pathway compared to the reaction of OH with SO2.

  16. Recent SO2 camera and OP-FTIR field measurements in Mexico and Guatemala

    NASA Astrophysics Data System (ADS)

    La Spina, Alessandro; Salerno, Giuseppe; Burton, Michael

    2013-04-01

    Between 22 and 30 November 2012 a field campaign was carried out at Mexico and Guatemala with the objectives of state the volcanic gas composition and flux fingerprints of Popocatepetl, Santiaguito, Fuego and Pacaya by exploiting simultaneously UV-camera and FTIR measurements. Gases were measured remotely using instruments sensitive to ultraviolet and infrared radiation (UV spectrometer, SO2-camera and OP-FTIR). Data collection depended on the requirements of the methodology, weather condition and eruptive stage of the volcanoes. OP-FTIR measurements were carried out using the MIDAC interferometer with 0.5 cm-1 resolution. Spectra were collected in solar occultation mode in which the Sun acts as an infrared source and the volcanic plume is interposed between the Sun and the spectrometer. At Santiaguito spectra were also collected in passive mode using the lava flow as a radiation source. The SO2-camera used for this study was a dual camera system consisting of two QS Imaging 640s cameras. Each of the two cameras was outfitted with two quartz 25mm lens, coupled with two band-pass filters centred at 310nm and at 330nm. The imaging system was managed by a custom-made software developed in LabView. The UV-camera system was coupled with a USB2000+ spectrometer connected to a QP1000-2-SR 1000 micron optical fiber with a 74-UV collimating lens. For calibration of plume imagery, images of five quartz cells containing known concentration path-lengths of SO2 were taken at the end of each sampling. Between 22 and 23 November 2012 UV-camera and FTIR observations were carried out at Popocatepetl. During the time of our observation, the volcano was characterised by pulsing degassing from the summit crater forming a whitish plume that dispersed rapidly in the atmosphere according to wind direction and speed. Data were collected from the Observatorio Atmosférico Altzomoni (Universidad Nacional Autónoma de México) at 4000 metre a.s.l. and at a distance of ~12 km from the volcano

  17. Recent SO2 camera and OP-FTIR field measurements in Mexico and Guatemala

    NASA Astrophysics Data System (ADS)

    La Spina, Alessandro; Salerno, Giuseppe; Burton, Michael

    2013-04-01

    Between 22 and 30 November 2012 a field campaign was carried out at Mexico and Guatemala with the objectives of state the volcanic gas composition and flux fingerprints of Popocatepetl, Santiaguito, Fuego and Pacaya by exploiting simultaneously UV-camera and FTIR measurements. Gases were measured remotely using instruments sensitive to ultraviolet and infrared radiation (UV spectrometer, SO2-camera and OP-FTIR). Data collection depended on the requirements of the methodology, weather condition and eruptive stage of the volcanoes. OP-FTIR measurements were carried out using the MIDAC interferometer with 0.5 cm-1 resolution. Spectra were collected in solar occultation mode in which the Sun acts as an infrared source and the volcanic plume is interposed between the Sun and the spectrometer. At Santiaguito spectra were also collected in passive mode using the lava flow as a radiation source. The SO2-camera used for this study was a dual camera system consisting of two QS Imaging 640s cameras. Each of the two cameras was outfitted with two quartz 25mm lens, coupled with two band-pass filters centred at 310nm and at 330nm. The imaging system was managed by a custom-made software developed in LabView. The UV-camera system was coupled with a USB2000+ spectrometer connected to a QP1000-2-SR 1000 micron optical fiber with a 74-UV collimating lens. For calibration of plume imagery, images of five quartz cells containing known concentration path-lengths of SO2 were taken at the end of each sampling. Between 22 and 23 November 2012 UV-camera and FTIR observations were carried out at Popocatepetl. During the time of our observation, the volcano was characterised by pulsing degassing from the summit crater forming a whitish plume that dispersed rapidly in the atmosphere according to wind direction and speed. Data were collected from the Observatorio Atmosférico Altzomoni (Universidad Nacional Autónoma de México) at 4000 metre a.s.l. and at a distance of ~12 km from the volcano

  18. EXPERIMENTAL AIR EXCLUSION SYSTEM FOR FIELD STUDIES OF SO2 EFFECTS ON CROP PRODUCTIVITY

    EPA Science Inventory

    The Tennessee Valley Authority (TVA) characterized and quantified relationships among sulfur dioxide (SO2) exposure, symptomatology of injury, and yield of soybean crops, which are sensitive to SO2 and economically important to the southeastern United States. Characterization inc...

  19. Top-Down Estimates of SO2 Degassing Emissions from the Turrialba Volcano Using in Situ Measurements from Unmanned Aerial Systems and the WRF-Stilt Model

    NASA Astrophysics Data System (ADS)

    Xi, X.; Johnson, M. S.; Fladeland, M. M.; Pieri, D. C.; Diaz, J. A.; Jeong, S.; Bland, G.

    2014-12-01

    In recent years, there has been a growing interest in the continuous volcanic degassing emissions as an important natural source of sulfur-rich gases and aerosols. To investigate the impact of volcanic degassing on atmospheric chemistry and climate forcing, chemical transport models rely on emission inventories compiled from various sources. For example, the emission database from the Aerosol Comparisons between Observations and Models (AEROCOM) project derives eruptive SO2 emissions from past literature, Volcanic Explosivity Index (VEI), and limited observations from satellite and in situ instruments. Additionally, for all volcanoes with historic eruptions, AEROCOM simply assigns a constant SO2 degassing rate of 6.2x10-4 kt/day. This rudimentary estimate can lead to large uncertainties in model simulations of the volcanic SO2lifecycle and its impact on the atmospheric composition. In this study, we propose to apply inverse modeling techniques to estimate top-down SO2 emission rates from the Turrialba Volcano (10.025°N, 83.767°W) using in situ SO2 measurements from unmanned aerial systems (UASs) during March 2013. We predict SO2 mixing ratios along the UASs' flight paths based on the AEROCOM a priori SO2 emission dataset and the atmospheric trajectories and surface influence simulated by the WRF-STILT model. We incorporate a high-resolution (~ 30 m) terrain data into the model in order to account for the effects of the complex orography on the wind conditions near the volcano. The predicted SO2 mixing ratios are compared with measurements in a statistical procedure to minimize the model-data difference thereby yielding improved posterior estimates of volcanic SO2 degassing emission rates. A detailed uncertainty analysis will be conducted during this study taking into account all sources of error in the inverse modeling approach, such as the SO2 measurements, meteorological inputs, model configurations (e.g., spatial resolution, model physics parameterizations

  20. Early in-flight detection of SO2 via Differential Optical Absorption Spectroscopy: A feasible aviation safety measure to prevent potential encounters with volcanic plumes

    NASA Astrophysics Data System (ADS)

    Vogel, L.; Galle, B.; Kern, C.; Delgado Granados, H.; Conde, V.; Norman, P.; Arellano, S.; Landgren, O.; Luebcke, P.; Alvarez Nieves, J.; Cárdenas Gonzáles, L.; Platt, U.

    2010-12-01

    Volcanic ash is a hazard to aviation mainly due to its threat to jet engines with the risk of total engine failure. Other hazards consist of abrasion of windshields and damage to avionic systems. These hazards have been widely recognized since the early 1980s, when volcanic ashes provoked severe incidents of engine failure of jet aircrafts (e.g. Mt. St. Helens, USA, 1980; Mt. Galunggung, Indonesia, 1982 and Redoubt volcano, USA, 1989). In addition to volcanic ash, also volcanic gases pose a threat. Prolonged and/or cumulative exposure of sulfur dioxide (SO2) or sulfuric acid (H2SO4) aerosols potentially affects e.g. windows, air frame and provokes damage to engines. SO2 receives most attention because its presence above the lower troposphere atmosphere is a clear proxy for a volcanic plume and indicates that fine ash could also be present. One of the most recent examples of volcanic ash impairing aviation is the eruption of Eyjafjallajoküll, Iceland, between March and May 2010, which lead to temporal closure of the European air space. Although no severe incidents were reported, it affected an unprecedented number of people and had a considerable negative economic impact on carriers. Up to now, remote sensing of SO2 via Differential Optical Spectroscopy (DOAS) in the ultraviolet spectral region has primarily been used to measure volcanic clouds from satellites and ground-based platforms. Here we present a set of experimental and model data, highlighting the feasibility of DOAS to be used as an airborne early detection system of SO2 distributions in two spatial dimensions. In order to prove the concept, simultaneous airborne and ground-based measurements were conducted at Popocatépetl volcano, Mexico, in April 2010. These observations were combined with radiative transfer studies modelling the conditions at hand. The ground based measurements were made by two stationary instruments, a further, mobile instrument was used to perform vehicle traverses below the plume

  1. 40 CFR 96.220 - General CAIR SO2 Trading Program permit requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false General CAIR SO2 Trading Program... (CONTINUED) AIR PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS Permits § 96.220 General CAIR SO2 Trading Program permit requirements....

  2. 40 CFR 75.33 - Standard missing data procedures for SO2, NOX, and flow rate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... SO2, NOX, and flow rate. 75.33 Section 75.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY....33 Standard missing data procedures for SO2, NOX, and flow rate. (a) Following initial certification of the required SO2, NOX, and flow rate monitoring system(s) at a particular unit or stack...

  3. 40 CFR 75.33 - Standard missing data procedures for SO2, NOX, and flow rate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... SO2, NOX, and flow rate. 75.33 Section 75.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY....33 Standard missing data procedures for SO2, NOX, and flow rate. (a) Following initial certification of the required SO2, NOX, and flow rate monitoring system(s) at a particular unit or stack...

  4. 40 CFR 75.33 - Standard missing data procedures for SO2, NOX, and flow rate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... SO2, NOX, and flow rate. 75.33 Section 75.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY....33 Standard missing data procedures for SO2, NOX, and flow rate. (a) Following initial certification of the required SO2, NOX, and flow rate monitoring system(s) at a particular unit or stack...

  5. 40 CFR 96.253 - Recordation of CAIR SO2 allowances.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Recordation of CAIR SO2 allowances. 96.253 Section 96.253 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... CAIR SO2 Allowance Tracking System § 96.253 Recordation of CAIR SO2 allowances. (a)(1) After...

  6. 40 CFR 96.253 - Recordation of CAIR SO 2 allowances.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Recordation of CAIR SO 2 allowances. 96.253 Section 96.253 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... IMPLEMENTATION PLANS CAIR SO2 Allowance Tracking System § 96.253 Recordation of CAIR SO 2 allowances....

  7. 40 CFR 96.253 - Recordation of CAIR SO 2 allowances.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Recordation of CAIR SO 2 allowances. 96.253 Section 96.253 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... IMPLEMENTATION PLANS CAIR SO2 Allowance Tracking System § 96.253 Recordation of CAIR SO 2 allowances....

  8. 40 CFR 96.253 - Recordation of CAIR SO2 allowances.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Recordation of CAIR SO2 allowances. 96.253 Section 96.253 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... CAIR SO2 Allowance Tracking System § 96.253 Recordation of CAIR SO2 allowances. (a)(1) After...

  9. STRUCTURAL TRANSFORMATIONS IN CA-BASED SORBENTS USED FOR SO2 EMISSION CONTROL

    EPA Science Inventory

    The paper discusses structural transformations in Ca-based sorbents used for SO2 emission control. conomizer temperature injection of Ca-based sorbents is an option for dry control of SO2 emissions from coal-fired boilers. heir reactivity with SO2 was found to be a function of th...

  10. REACTIVATION OF SOLIDS FROM FURNACE INJECTION OF LIMESTONE FOR SO2 CONTROL

    EPA Science Inventory

    The paper gives results of a characterization of post-furnace injection solids and flyash mixtures and their testing in a bench-scale reactor for the removal of SO2. Virtually no SO2 removal was observed with untreated solids. High SO2 capture occurred when the samples were hydra...

  11. 40 CFR 75.33 - Standard missing data procedures for SO2, NOX, and flow rate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... SO2, NOX, and flow rate. 75.33 Section 75.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY....33 Standard missing data procedures for SO2, NOX, and flow rate. (a) Following initial certification of the required SO2, NOX, and flow rate monitoring system(s) at a particular unit or stack...

  12. JOINT ACTION OF O3 AND SO2 IN MODIFYING PLANT GAS EXCHANGE

    EPA Science Inventory

    The joint action of O3 and SO2 stress on plants was investigated. Gas exchange measurements of O3, SO2, and H2O vapor were made for garden pea. Plants were grown under controlled environments; O3, SO2, H2O vapor fluxes were evaluated with a whole-plant gas exchange chamber using ...

  13. A rapid deployment instrument network for temporarily monitoring volcanic SO2 emissions - a case study from Telica volcano

    NASA Astrophysics Data System (ADS)

    Conde, V.; Nilsson, D.; Galle, B.; Cartagena, R.; Muñoz, A.

    2014-08-01

    Volcanic gas emissions play a crucial role in describing geophysical processes; hence, measurements of magmatic gases such as SO2 can be used as tracers prior to and during volcanic crises. Different measurement techniques based on optical spectroscopy have provided valuable information when assessing volcanic crises. This paper describes the design and implementation of a network of spectroscopic instruments based on differential optical absorption spectroscopy (DOAS) for remote sensing of volcanic SO2 emissions, which is robust, portable and can be deployed in relatively short time. The setup allows the processing of raw data in situ even in remote areas with limited accessibility, and delivers pre-processed data to end users in near real time, even during periods of volcanic crisis, via a satellite link. In addition, the hardware can be used to conduct short-term studies of volcanic plumes in remote areas. We describe here tests of the network at Telica, an active volcano located in western Nicaragua, during three different measurement periods, including an eruptive crisis. The tests produced what is so far the largest data set of continuous SO2 flux measurements at this volcano. The measurements show that, during the period 2010-2013, the flux averages approximately 100 tons per day (t day-1).

  14. A rapid deployment instrument network for temporarily monitoring volcanic SO2 emissions - a study case from Telica volcano

    NASA Astrophysics Data System (ADS)

    Conde, V.; Nilsson, D.; Galle, B.; Cartagena, R.; Muñoz, A.

    2014-04-01

    Volcanic gas emissions play a crucial role in describing geophysical processes; hence measurements of magmatic gases such as SO2 can be used as tracers prior and during volcanic crises. Different measurement techniques based on optical spectroscopy have provided valuable information when assessing volcanic crises. This paper describes the design and implementation of a network of spectroscopic instruments based on Differential Optical Absorption Spectroscopy (DOAS) for remote sensing of volcanic SO2 emissions, which is robust, portable and can be deployed in relative short time. The setup allows the processing of raw data in situ even in remote areas with limited accessibility, and delivers pre-processed data to end-users in near real time even during periods of volcanic crisis, via a satellite link. In addition, the hardware can be used to conduct short term studies of volcanic plumes in remotes areas. The network was tested at Telica, an active volcano located in western Nicaragua, producing what is so far the largest data set of continuous SO2 flux measurements at this volcano.

  15. Effect of SO2 concentration on SOA formation in a photorreactor from a mixture of anthropogenic hydrocarbons and HONO

    NASA Astrophysics Data System (ADS)

    García Vivanco, Marta; Santiago, Manuel; García Diego, Cristina; Borrás, Esther; Ródenas, Milagros; Martínez-Tarifa, Adela

    2010-05-01

    Sulfur dioxide (SO2) is an important urban atmospheric pollutant, mainly produced by the combustion of fossil fuels containing sulfur. In the atmosphere, SO2 can react with OH radicals to form sulfuric acid, which can condense to form acidic aerosol. Sulfuric acid particles act as an acid catalyst for some heterogeneous carbonyl reactions like hydration, polymerization or acetals formation, which may lead to a large increase on SOA mass. In order to evaluate the effect of the SO2 concentration on SOA formation, 3 experiments were performed during the campaign carried out by CIEMAT on the EUPHORE facility (CEAM, Valencia, Spain) during June- July 2008. The objective of the campaign was to evaluate the effect of different experimental conditions on SOA formation from the photooxidation of some anthropogenic and biogenic VOCs using HONO as oxidant. Experiment on 6/17/08 was selected as base case (no SO2 was introduced) and experiments 6/26/08 and 7/1/08 were selected as high SO2 (2600 ug/m3) and low SO2 (60 ug/m3) concentration experiments respectively. In the three experiments a mixture of toluene, 1,3,5-TMB (trimethylbenzene), o-xylene and octane was selected as the parent VOCs. Single and coupled to mass spectroscopy gas cromatography (GC and GC/MS), as well as high performance liquid chromatography (HPLC) and Fourier transform infrared spectroscopy (FTIR) were used to measure the initial VOCs and oxidant concentrations decay and the formation of gas phase oxidation products through the experiments. Aerosol size distribution and concentration were measured with SMPS (scanning mobility particle sizer) and TEOM (tapered element oscillating monitor) respectively. In addition, analysis of the organic and inorganic aerosol content was also performed via filter sampling followed by GC/MS and ionic chromatography (for organic and inrganic content respectively). Comparing the filters collected in the three experiments, clearly the largest mass aerosol formation is observed

  16. Simultaneous treatment of NO and SO2 with aqueous NaClO2 solution in a wet scrubber combined with a plasma electrostatic precipitator.

    PubMed

    Park, Hyun-Woo; Choi, Sooseok; Park, Dong-Wha

    2015-03-21

    NO and SO2 gases that are generally produced in thermal power plants and incinerators were simultaneously removed by using a wet scrubber combined with a plasma electrostatic precipitator. The wet scrubber was used for the absorption and oxidation of NO and SO2, and non-thermal plasma was employed for the electrostatic precipitation of aerosol particles. NO and SO2 gases were absorbed and oxidized by aerosol particles of NaClO2 solution in the wet scrubber. NO and SO2 reacted with the generated NaClO2 aerosol particles, NO2 gas, and aqueous ions such as NO2(-), NO3(-), HSO3(-), and SO4(2-). The aerosol particles were negatively charged and collected on the surface of grounded anode in the plasma electrostatic precipitator. The NO and SO2 removal efficiencies of the proposed system were 94.4% and 100% for gas concentrations of 500 mg/m(3) and a total gas flow rate of 60 Nm(3)/h, when the molar flow rate of NaClO2 and the gas-liquid contact time were /min and 1.25 s, respectively. The total amount and number of aerosol particles in the exhaust gas were reduced to 7.553 μg/m(3) and 210/cm(3) at the maximum plasma input power of 68.8 W, which are similar to the values for clean air. PMID:25497024

  17. Measurements of Acidic Gases and Aerosol Species Aboard the NASA DC-8 Aircraft During the Pacific Exploratory Mission in the Tropics (PEM-Tropics A)

    NASA Technical Reports Server (NTRS)

    Talbot, Robert W.; Dibb, Jack E.

    1999-01-01

    We received funding to provide measurements of nitric acid (HNO3), formic acid (HCOOH), acetic acid (CH3COOH), and the chemical composition of aerosols aboard the NASA Ames DC-8 research aircraft during the PEM-Tropics A mission. These measurements were successfully completed and the final data resides in the electronic archive (ftp-gte.larc.nasa.gov) at NASA Langley Research Center. For the PEM-Tropics A mission the University of New Hampshire group was first author of four different manuscripts. Three of these have now appeared in the Journal of Geophysical Research-Atmospheres, included in the two section sections on PEM-Tropics A. The fourth manuscript has just recently been submitted to this same journal as a stand alone paper. All four of these papers are included in this report. The first paper (Influence of biomass combustion emissions on the distribution of acidic trace gases over the Southern Pacific basin during austral springtime) describes the large-scale distributions of HNO3, HCOOH, and CH3COOH. Arguments were presented to show, particularly in the middle tropospheric region, that biomass burning emissions from South America and Africa were a major source of acidic gases over the South Pacific basin. The second paper (Aerosol chemical composition and distribution during the Pacific Exploratory Mission (PEM) Tropics) covers the aerosol aspects of our measurement package. Compared to acidic gases, O3, and selected hydrocarbons, the aerosol chemistry showed little influence from biomass burning emissions. The data collected in the marine boundary layer showed a possible marine source of NH3 to the troposphere in equatorial areas. This source had been speculated on previously, but our data was the first collected from an airborne platform to show its large-scale features. The third paper (Constraints on the age and dilution of Pacific Exploratory Mission-Tropics biomass burning plumes from the natural radionuclide tracer Pb-210) utilized the unexpectedly

  18. Operational real-time monitoring of volcanic SO2 emission rates using an innovative SO2 camera system and sophisticated retrieval techniques (Invited)

    NASA Astrophysics Data System (ADS)

    Kern, C.; Burton, M. R.; Elias, T.; Luebcke, P.; Mori, T.; Esposti Ongaro, T.; Prata, F.; Sutton, A. J.; Tamburello, G.; Werner, C. A.

    2013-12-01

    With the advent of SO2 camera systems some years ago, it became possible to image volcanic SO2 plumes at high temporal and spatial resolutions. Systems operating in the ultra-violet region measure the absorption of scattered solar radiation by SO2 in a narrow wavelength channel centered around 310 nm. A first-order correction for the effect of aerosol scattering is obtained by recording coincident images in at least one additional, off-band channel, typically centered around 330 nm. The promise of measuring SO2 emission rates at time resolutions comparable to geophysical techniques has led to increasingly widespread application of such systems. Until recently, however, a number of issues made SO2 camera systems difficult to use quantitatively for continuous monitoring. For one, UV-sensitive CCD camera technology lacked the durability required for continuous use. Also, because these camera systems collect very limited spectral information the potentially complex radiative transfer of a given scene, which can significantly impact SO2 retrievals, was not quantifiable. System calibrations were typically performed using gas cell measurements, but this approach is not valid for distant or optically thick plumes, or for plumes containing ash. Finally, the use of simple correlation techniques to derive plume velocity usually required manual input and did not take into account that the velocity typically varies throughout the plume. Together, these effects could easily lead to absolute errors of 100% or more in retrieved SO2 emission rates. Here we present solutions to these major challenges. First, we describe an SO2 camera system that uses two modern UV-sensitive CCD cameras with electronic shutters that are integrated with a moderate resolution UV spectrometer. The system software retrieves plume velocity fields in two dimensions, thus improving the accuracy of the derived SO2 emission rates while at the same time providing purposeful data for the study of plume dynamics

  19. Greenhouse Gases

    MedlinePlus

    ... Greenhouse Gases Come From Outlook for Future Emissions Recycling and Energy Nonrenewable Sources Oil and Petroleum Products ... Power Wave Power Ocean Thermal Energy Conversion Biomass Wood and Wood Waste Waste-to-Energy (MSW) Landfill ...

  20. Temperature effects on the retrieval of SO2 from ultraviolet satellite observations

    NASA Astrophysics Data System (ADS)

    Yan, Huanhuan; Wang, Weihe; Chen, Liangfu

    2014-11-01

    Sulfur dioxide (SO2) has a significant impact on the urban environment pollution and global climate. Compared with regional ground monitoring networks, satellite remote sensing technology provides an unprecedented advantage for continuous, large spatial and short-revisit monitoring for atmospheric SO2. Approaches for retrieval of SO2 from ultraviolet satellite observations have been developed and applied to detection of volcanic SO2 and regional emissions. However, these retrieval algorithms do not consider the temperature variation effect on SO2 retrievals, and simply use the absorption coefficient at a constant temperature as inputs for SO2 retrievals. In this study, hyperspectral OMI measurements were used to analyze the temperature effects on the retrieval of SO2 columns. Results of DOAS algorithm showed that with increasing SO2 concentration, the retrieval errors caused by temperature effects accumulated, and the differences in SO2 columns increased to a maximum of ~25 DU (SO2 column of 293K: ~65 DU). Therefore, atmospheric temperature is an important factor which has significant influence to high precise atmospheric SO2 retrievals.

  1. Re-processing TOMS UV Measurements to Retrieve SO2 Emissions From Volcanic Eruptions

    NASA Astrophysics Data System (ADS)

    Fisher, B. L.; Krotkov, N. A.; Bhartia, P. K.; Li, C.; Haffner, D. P.; Leonard, P.; Carn, S. A.; Telling, J. W.

    2015-12-01

    The SO2 Monitoring Group at the NASA Goddard Space Flight Center is producing a new multi-satellite long term data set of volcanic SO2 column amounts and heights (MSVOLSO2L4) as part of the NASA MEaSUREs Program. Here we present re-analysis of the UV measurements (BUV) from the NASA Nimbus 7 Total Ozone Mapping Spectrometer (N7 TOMS: 1978-1993). Ozone is the dominant atmospheric absorber in the BUV spectrum, but volcanic eruptions can produce enough SO2 to be distinguished from ozone background. Quantitative retrieval of volcanic SO2 requires:1) Separation of the O3 and SO2 absorption in BUV radiances;2) Close to zero mean SO2 background;3) RT forward model that accounts for the presence of volcanic ash in the plume; 4) A priori knowledge of the ozone and SO2 vertical profiles.Our iterative retrieval algorithm returns O3 and SO2 column amounts, effective reflectivity and its spectral slope. The retrieval model also generates a 4 x 4 gain matrix for the SO2 free regions that is used to soft calibrate the measured 340 nm BUV radiance. The spectral slope implicitly accounts for the interference of volcanic ash, but more explicit ash treatment is required to better quantify SO2 errors in volcanic plumes heavily loaded with ash. This presentation will discuss the methods used to characterize the error sources and assess the quality of this unique long-term SO2 data set.

  2. Seasonal and diurnal patterns in the dispersion of SO2 from Mt. Nyiragongo

    NASA Astrophysics Data System (ADS)

    Dingwell, Adam; Rutgersson, Anna; Claremar, Björn; Arellano, Santiago; Yalire, Mathieu M.; Galle, Bo

    2016-05-01

    Mt. Nyiragongo is an active volcano located in the Democratic Republic of Congo, close to the border of Rwanda and about 15 km north of the city of Goma (∼ 1,000,000 inhabitants). Gases emitted from Nyiragongo might pose a persistent hazard to local inhabitants and the environment. While both ground- and satellite-based observations of the emissions exist, prior to this study, no detailed analysis of the dispersion of the emissions have been made. We have conducted a dispersion study, using a modelling system to determine the geographical distribution of SO2. A combination of a meteorological model (WRF), a Lagrangian particle dispersion model (FLEXPART-WRF) and flux data based on DOAS measurements from the NOVAC-network is used. Since observations can only be made during the day, we use random sampling of fluxes and ensemble modelling to estimate night-time emissions. Seasonal variations in the dispersion follows the migration of the Inter Tropical Convergence Zone. In June-August, the area with the highest surface concentrations is located to the northwest, and in December-February, to the southwest of the source. Diurnal variations in surface concentrations were determined by the development of the planetary boundary layer and the lake-/land breeze cycle around lake Kivu. Both processes contribute to low surface concentrations during the day and high concentrations during the night. However, the strong northerly trade winds in November-March weakened the lake breeze, contributing to higher daytime surface concentrations along the northern shore of Lake Kivu, including the city of Goma. For further analysis and measurements, it is important to include both seasonal and diurnal cycles in order to safely cover periods of high and potentially hazardous concentrations.

  3. Seasonal and diurnal patterns in the dispersion of SO2 from Mt. Nyiragongo

    NASA Astrophysics Data System (ADS)

    Dingwell, Adam; Rutgersson, Anna; Claremar, Björn; Arellano, Santiago; Yalire, Mathieu M.; Galle, Bo

    2016-05-01

    Mt. Nyiragongo is an active volcano located in the Democratic Republic of Congo, close to the border of Rwanda and about 15 km north of the city of Goma (∼ 1,000,000 inhabitants). Gases emitted from Nyiragongo might pose a persistent hazard to local inhabitants and the environment. While both ground- and satellite-based observations of the emissions exist, prior to this study, no detailed analysis of the dispersion of the emissions have been made. We have conducted a dispersion study, using a modelling system to determine the geographical distribution of SO2. A combination of a meteorological model (WRF), a Lagrangian particle dispersion model (FLEXPART-WRF) and flux data based on DOAS measurements from the NOVAC-network is used. Since observations can only be made during the day, we use random sampling of fluxes and ensemble modelling to estimate night-time emissions. Seasonal variations in the dispersion follows the migration of the Inter Tropical Convergence Zone. In June-August, the area with the highest surface concentrations is located to the northwest, and in December-February, to the southwest of the source. Diurnal variations in surface concentrations were determined by the development of the planetary boundary layer and the lake-/land breeze cycle around lake Kivu. Both processes contribute to low surface concentrations during the day and high concentrations during the night. However, the strong northerly trade winds in November-March weakened the lake breeze, contributing to higher daytime surface concentrations along the northern shore of Lake Kivu, including the city of Goma. For further analysis and measurements, it is important to include both seasonal and diurnal cycles in order to safely cover periods of high and potentially hazardous concentrations.

  4. SO2 columns over China: Temporal and spatial variations using OMI and GOME-2 observations

    NASA Astrophysics Data System (ADS)

    Huanhuan, Yan; Liangfu, Chen; Lin, Su; Jinhua, Tao; Chao, Yu

    2014-03-01

    Enhancements of SO2 column amounts due to anthropogenic emission sources over China were shown in this paper by using OMI and GOME-2 observations. The temporal and spatial variations of SO2 columns over China were analyzed for the time period 2005-2010. Beijing and Chongqing showed a high concentration in the SO2 columns, attributable to the use of coal for power generation in China and the characteristic of terrain and meteorology. The reduction of SO2 columns over Beijing and surrounding provinces in 2008 was observed by OMI, which confirms the effectiveness of strict controls on pollutant emissions and motor vehicle traffic before and during 2008 Olympic and Paralympic Games. The SO2 columns over China from GOME-2 (0.2-0.5 DU) were lower than those from OMI (0.6-1 DU), but both showed a decrease in SO2 columns over northern China since 2008 (except an increase in OMI SO2 in 2010).

  5. Comparison of seismic and SO2 time series recorded during eruptive phases of Tungurahua volcano (Ecuador) between 2010 and 2013

    NASA Astrophysics Data System (ADS)

    Battaglia, J.; Hidalgo, S.; Steele, A.; Arellano, S. R.; Ruiz, M. C.; Galle, B.

    2013-12-01

    Tungurahua is one of the most active volcanoes in Ecuador. It is a large andesitic stratovolcano which has been continuously erupting since 1999. Its activity has slightly changed since late 2009 and is now characterized by the occurrence of well-defined eruptive phases lasting from few weeks to months, separated by quiescence periods with a comparable duration range. Eruptive phases include the emission of ash and gases with the occurrence of Strombolian to Vulcanian explosions that can produce short runout pyroclastic flows. The monitoring networks operating on the volcano include 4 permanent DOAS instruments, 5 broadband seismic stations coupled with infrasound sensors and 5 short period seismometers. We examined the data from these instruments for the period 2010-2013 with the aim of looking for possible correlations between seismic and acoustic recordings and the amounts of SO2 emitted by the volcano. The seismicity related to eruptive/degassing processes is dominated by explosion quakes and longer duration tremors. To quantify both phenomena, we proceeded in two ways. First, we established the acoustic and seismic energies of individual explosions and calculated cumulative daily values. Secondly, to quantify the intensity of background tremor we calculated sliding median amplitudes in different frequency bands. On the other hand, NOVAC-1 type DOAS spectrometers operate during daylight only providing up to 140 daily measurements. Valid measurements are only obtained under good weather conditions, leading to irregular and sometimes sparse time series. Usually, daily average fluxes of SO2 are extrapolated from the available measurements. Alternately, we determined the daily observed SO2 masses by integrating all valid recordings during the 11 hours of daily measurement. This approach strongly reduces SO2 measured emissions during quiescence periods and provides time series having an improved correlation on a long time scale (years) with the eruptive phases of

  6. OH- Initiated Heterogeneous Oxidation of Saturated Organic Aerosols in the Presence of SO2: Uptake Kinetics and Product Identification.

    NASA Astrophysics Data System (ADS)

    Richards-Henderson, N. K.; Ward, M.; Goldstein, A. H.; Wilson, K. R.

    2014-12-01

    Gas-phase oxidation mechanisms for organic gases are often used as a starting point to understand heterogeneous oxidation. The reaction of a simple alkane hydrocarbon by OH proceeds through hydrogen abstraction and under ambient conditions leads to peroxy radical (RO2) formation. RO2 can further react to form: (1) smaller molecular weight products (i.e. fragmentation) via alkoxy radical formation and dissociation and/or (2) higher molecular weight products with oxygenated functional groups (i.e. functionalization). The ability to perturb these two pathways (functionalization vs. fragmentation) is critical for understanding the detailed reaction mechanism that control atmospheric aging chemistry of particles. At high temperatures the presence of sulfur dioxide (SO2) during organic-OH gas-phase oxidation enhances the fragmentation pathway leading to increased alkoxy formation. It is unknown if a comparative affect occurs at room temperature during a heterogeneous reaction. We used the heterogeneous reaction of OH radicals with sub-micron squalane particles in the presence and absence of SO2 as a model system to explore changes in individual mechanistic pathways. Detailed kinetic measurements were made in a flow tube reactor using a vacuum ultraviolet (VUV) photoionization aerosol mass spectrometer and oxidation products are identified from samples collected on quartz filters using thermal desorption two-dimensional chromatographic separation and ionization by either VUV (10.5 eV) or electron impact (70 eV), with detection by high resolution time of flight mass spectrometry (GCxGC-VUV/EI-HRTOFMS). In the presence of SO2 the yields of alcohols were enhanced compared to without SO2, suggesting that the alkoxy formation pathway was dominant. The results from this work will provide an experimentally-confirmed kinetic framework that could be used to model atmospheric aging mechanisms.

  7. Validation of the i-STAT system for the analysis of blood gases and acid-base status in juvenile sandbar shark (Carcharhinus plumbeus).

    PubMed

    Harter, T S; Morrison, P R; Mandelman, J W; Rummer, J L; Farrell, A P; Brill, R W; Brauner, C J

    2015-01-01

    Accurate measurements of blood gases and acid-base status require an array of sophisticated laboratory equipment that is typically not available during field research; such is the case for many studies on the stress physiology, ecology and conservation of elasmobranch fish species. Consequently, researchers have adopted portable clinical analysers that were developed for the analysis of human blood characteristics, but often without thoroughly validating these systems for their use on fish. The aim of our study was to test the suitability of the i-STAT system, the most commonly used portable clinical analyser in studies on fish, for analysing blood gases and acid-base status in elasmobranchs, over a broad range of conditions and using the sandbar shark (Carcharhinus plumbeus) as a model organism. Our results indicate that the i-STAT system can generate useful measurements of whole blood pH, and the use of appropriate correction factors may increase the accuracy of results. The i-STAT system was, however, unable to generate reliable results for measurements of partial pressure of oxygen (PO2) and the derived parameter of haemoglobin O2 saturation. This is probably due to the effect of a closed-system temperature change on PO2 within the i-STAT cartridge and the fact that the temperature correction algorithms used by i-STAT assume a human temperature dependency of haemoglobin-O2 binding; in many ectotherms, this assumption will lead to equivocal i-STAT PO2 results. The in vivo partial pressure of CO2 (PCO2) in resting sandbar sharks is probably below the detection limit for PCO2 in the i-STAT system, and the measurement of higher PCO2 tensions was associated with a large measurement error. In agreement with previous work, our results indicate that the i-STAT system can generate useful data on whole blood pH in fishes, but not blood gases. PMID:27293687

  8. SO2 flux monitoring at Stromboli with the new permanent INGV SO2 camera system: A comparison with the FLAME network and seismological data

    NASA Astrophysics Data System (ADS)

    Burton, M. R.; Salerno, G. G.; D'Auria, L.; Caltabiano, T.; Murè, F.; Maugeri, R.

    2015-07-01

    We installed a permanent SO2 camera system on Stromboli, Italy, in May 2013, in order to improve our capacity to monitor the SO2 emissions from this volcano. The camera collects images of SO2 concentrations with a period of ~ 10 s, allowing quantification of short-term processes, such as the gas released during the frequent explosions which are synonymous with Stromboli. It also allows quantification of the quiescent gas flux, and therefore comparison with the FLAME network of scanning ultraviolet spectrometers previously installed on the island. Analysis of results from the SO2 camera demonstrated a good agreement with the FLAME network when the plume was blown fully into the field of view of the camera. Permanent volcano monitoring with SO2 cameras is still very much in its infancy, and therefore this finding is a significant step in the use of such cameras for monitoring, whilst also highlighting the requirement of a favourable wind direction and strength. We found that the explosion gas emissions are correlated with seismic events which have a very long period component. There is a variable time lag between event onset time and the increase in gas flux observed by the camera as the explosion gas advects into the field of view of the camera. This variable lag is related to the plume direction, as shown by comparison with the plume location detected with the FLAME network. The correlation between explosion gas emissions and seismic signal amplitude show is consistent with a gas slug-driven mechanism for seismic event production. Comparison of the SO2 camera measurements of the quiescent gas flux shows a fair quantitative agreement with the SO2 flux measured with the FLAME network. Overall, the SO2 camera complements the FLAME network well, as it allows frequent quantification of the explosion gas flux produced by Stromboli, whose signal is in general too brief to be measured with the FLAME network. Further work is required, however, to fully automate the

  9. Use Of Cosmogenic 35S To Trace The Uptake Process Of SO2 In Aerosols In The Atmosphere

    NASA Astrophysics Data System (ADS)

    Abramian, A.; Corbin, A.

    2008-12-01

    Environmental issues, such as acid rain and global warming, are linked to increased sulfur emissions and sulfate production in the atmosphere. Sulfate aerosol particles act as cloud condensation nuclei and can reduce the greenhouse effect by the indirect effect. Our understanding of the chemical and photochemical processes that govern the chemical transformations and transport of sulfur compounds in the atmosphere is still incomplete due to the complex, multivalent nature of sulfur and uncertainties in aerosol chemistry and transport (particularly trans-oceanic). We explore the use of cosmogenically produced 35S (half-life~87 days) to trace the uptake of SO2 gas into aerosols, as a function of aerosol size, in two different environments by simultaneously collecting and measuring [35SO42- ]and [35SO2]. These measurements can in turn be used to understand the time scales of SO2 oxidation to SO42-, aerosol 'age' and boundary layer dynamics. Aerosol samples are collected on glass fiber filters twice a week at Scripps Institute of Oceanography Pier in La Jolla, CA and the San Fernando Valley, CA for a 21-day period. SO2 (g) was collected on KOH impregnated filters placed after a 4-stage aerosol filter stack. We present preliminary results for both fine and coarse aerosol sulfate [35SO4] as well as [35SO2]. These measurements were done using low-noise liquid scintillation spectroscopy. By measuring the activity of each sample repeatedly over a period of 100 days, the exponential decay of 35S was observed, confirming the identity of the radioactive signal. The coastal and inland measurements are compared and implications for the atmospheric chemistry of SO2 and SO4 are discussed. Finally, we assess the potential of using [35SO4]/[nss-SO4] as a tracer of primary sulfate and trans-oceanic transport by coupling the measurements of the cation (Na+, Ca2+, K+, Mg2+, NH4+) and anion (Cl, NO3, SO4) concentrations in the aerosols.

  10. Variability of SO2, CO and light hydrocarbons over a megacity in Eastern India: effects of emissions and transport

    NASA Astrophysics Data System (ADS)

    Mallik, C.; Ghosh, D.; Sarkar, U.; Lal, S.; Venkataramani, S.

    2013-12-01

    Continuous measurements of SO2 during March 2012 - February 2013 along with sampling based measurements of CO, CH4 and C2-C5 NMHCs were made over Kolkata (the world's 16th largest megacity in terms of population) to study emission characteristics over this South Asian megacity. The observed SO2 concentrations are comparable to several Asian sites but higher than American/European sites. Further, C3H8 and C4H10 are substantially higher over the study region compared to many other Asian cities. The mean SO2 and C2H6 concentrations during winter and post-monsoon periods were 5 and 3 times higher compared to pre-monsoon and monsoon. High levels of SO2 during winter (>6 ppbv) are attributed to regional emissions and subsequent trapping of these air masses favored by a stable atmosphere with low ventilation coefficient. Coal burning in industrial areas and power plants in eastern Indo-Gangetic Plains (IGP) are identified as potential source regions for SO2 during winter. Daytime elevations in SO2 during summer seem to be related to photo-oxidation of RSCs from a nearby landfill region. Early morning enhancements during winter for several trace gases indicate the role of boundary layer dynamics. Interspecies correlations show the dominant influence of LPG leakage and petrochemical industries to local air quality during winter apart from vehicular traffic. Correlation analysis shows that CO is dominated by biofuel combustions. Positive matrix factorization is used to identify different emission sources influencing the air quality over the study region. The concentrations over Kolkata may be interpreted as the end point of anthropogenic inputs to the IGP outflow into the Bay of Bengal (BoB) and subsequently the Indian Ocean during winter. Usefulness of these measurements (e.g. C2H2 to CO ratios) as initial values in calculating photochemical processing of air masses over the BoB will be discussed during the presentation. From the point of view of emission inventories, these

  11. Hydrophobic task-specific ionic liquids: synthesis, properties and application for the capture of SO2.

    PubMed

    Tian, Shidong; Hou, Yucui; Wu, Weize; Ren, Shuhang; Qian, Jianguo

    2014-08-15

    The capture of SO2 by ionic liquids (ILs) has drawn much attention all over the world. However, ILs can absorb not only SO2 but also water from flue gas. The removal of water from ILs is necessary for reusing the absorbent. In order to reduce the energy costs of removing water, it would be helpful to weaken the interactions between ILs and water. In this work, two kinds of hydrophobic task-specific ILs, 1-(2-diethyl-aminoethyl)-3-methylimidazolium hexafluorophosphate ([Et2NEmim] [PF6]) and 1-(2-diethyl-aminoethyl)-1-methylpyrrolidinium hexafluorophosphate ([Et2NEmpyr][PF6]), were designed and synthesized. Thermal stability and physical properties of the ILs were studied. Furthermore, the application of the ILs for the capture of SO2 and the absorption mechanism were systematically investigated. It has been found that both of the ILs are immiscible with water, and [Et2NEmim][PF6] has much lower viscosity, much higher thermal stability and much higher SO2 absorption rate than [Et2NEmpyr][PF6]. [Et2NEmim][PF6] shows high SO2 absorption capacities up to 2.11 mol SO2 per mole IL (pure SO2) and 0.94 mol SO2 per mole IL (3% SO2) under hydrous conditions at 30 °C. The result suggests that [Et2NEmim][PF6] is a promising recyclable absorbent for the capture of SO2. PMID:24998204

  12. Meteorological influence on predicting surface SO2 concentration from satellite remote sensing in Shanghai, China.

    PubMed

    Xue, Dan; Yin, Jingyuan

    2014-05-01

    In this study, we explored the potential applications of the Ozone Monitoring Instrument (OMI) satellite sensor in air pollution research. The OMI planetary boundary layer sulfur dioxide (SO2_PBL) column density and daily average surface SO2 concentration of Shanghai from 2004 to 2012 were analyzed. After several consecutive years of increase, the surface SO2 concentration finally declined in 2007. It was higher in winter than in other seasons. The coefficient between daily average surface SO2 concentration and SO2_PBL was only 0.316. But SO2_PBL was found to be a highly significant predictor of the surface SO2 concentration using the simple regression model. Five meteorological factors were considered in this study, among them, temperature, dew point, relative humidity, and wind speed were negatively correlated with surface SO2 concentration, while pressure was positively correlated. Furthermore, it was found that dew point was a more effective predictor than temperature. When these meteorological factors were used in multiple regression, the determination coefficient reached 0.379. The relationship of the surface SO2 concentration and meteorological factors was seasonally dependent. In summer and autumn, the regression model performed better than in spring and winter. The surface SO2 concentration predicting method proposed in this study can be easily adapted for other regions, especially most useful for those having no operational air pollution forecasting services or having sparse ground monitoring networks. PMID:24362515

  13. The vertical distribution of volcanic SO2 plumes measured by IASI

    NASA Astrophysics Data System (ADS)

    Carboni, Elisa; Grainger, Roy G.; Mather, Tamsin A.; Pyle, David M.; Thomas, Gareth E.; Siddans, Richard; Smith, Andrew J. A.; Dudhia, Anu; Koukouli, Mariliza E.; Balis, Dimitrios

    2016-04-01

    Sulfur dioxide (SO2) is an important atmospheric constituent that plays a crucial role in many atmospheric processes. Volcanic eruptions are a significant source of atmospheric SO2 and its effects and lifetime depend on the SO2 injection altitude. The Infrared Atmospheric Sounding Interferometer (IASI) on the METOP satellite can be used to study volcanic emission of SO2 using high-spectral resolution measurements from 1000 to 1200 and from 1300 to 1410 cm-1 (the 7.3 and 8.7 µm SO2 bands) returning both SO2 amount and altitude data. The scheme described in Carboni et al. (2012) has been applied to measure volcanic SO2 amount and altitude for 14 explosive eruptions from 2008 to 2012. The work includes a comparison with the following independent measurements: (i) the SO2 column amounts from the 2010 Eyjafjallajökull plumes have been compared with Brewer ground measurements over Europe; (ii) the SO2 plumes heights, for the 2010 Eyjafjallajökull and 2011 Grimsvötn eruptions, have been compared with CALIPSO backscatter profiles. The results of the comparisons show that IASI SO2 measurements are not affected by underlying cloud and are consistent (within the retrieved errors) with the other measurements. The series of analysed eruptions (2008 to 2012) show that the biggest emitter of volcanic SO2 was Nabro, followed by Kasatochi and Grímsvötn. Our observations also show a tendency for volcanic SO2 to reach the level of the tropopause during many of the moderately explosive eruptions observed. For the eruptions observed, this tendency was independent of the maximum amount of SO2 (e.g. 0.2 Tg for Dalafilla compared with 1.6 Tg for Nabro) and of the volcanic explosive index (between 3 and 5).

  14. Joint Action of O3 and SO2 in Modifying Plant Gas Exchange 1

    PubMed Central

    Olszyk, David M.; Tingey, David T.

    1986-01-01

    The joint action of O3 and SO2 stress on plants was investigated by determining the quantitative relationship between air pollutant fluxes and effects on stomatal conductance. Gas exchange measurements of O3, SO2, and H2O vapor were made for Pisum sativum L. (garden pea). Plants were grown under controlled environments, and O3, SO2, and H2O vapor fluxes were evaluated with a whole-plant gas exchange chamber using the mass-balance approach. Maximum O3 and SO2 fluxes per unit area (2 sided) into leaves averaged 8 nanomoles per square meter per second with exposure to either O3 or SO2 at 0.1 microliters per liter. Internal fluxes of either O3 or SO2 were reduced by up to 50% during exposure to combined versus individual pollutants; the greatest reduction occurred with simultaneous versus sequential combinations of the pollutants. Stomatal conductance to H2O was substantially altered by the pollutant exposures, with O3 molecules twice as effective as SO2 molecules in inducing stomatal closure. Stomatal conductance was related to the integrated dose of pollutants. The regression equations relating integrated dose to stomatal conductance were similar with O3 alone, O3 plus added SO2, and O3 plus SO2 simultaneously; i.e. a dose of 100 micromoles per square meter produced a 39 to 45% reduction in conductance over nonexposed plants. With SO2 alone, or SO2 plus added O3, a dose of 100 micromoles per square meter produced a 20 to 25% reduction in conductance. When O3 was present at the start of the exposure, then stomatal response resembled that for O3 more than the response for SO2. This study indicated that stomatal responses with combinations of O3 and SO2 are not dependent solely on the integrated dose of pollutants, but suggests that a metabolic synergistic effect exists. PMID:16665041

  15. Efficient fractionation of spruce by SO(2)-ethanol-water treatment: closed mass balances for carbohydrates and sulfur.

    PubMed

    Iakovlev, Mikhail; van Heiningen, Adriaan

    2012-08-01

    SO(2)-ethanol-water (SEW) lignocellulosic fractionation has the potential to overcome the present techno-economic barriers that hinder the commercial implementation of renewable transportation fuel production. In this study, SEW fractionation of spruce wood chips is examined for its ability to separate the main wood components, hemicelluloses, lignin, and cellulose, and the potential to recover SO(2) and ethanol from the spent fractionation liquid. Therefore, overall sulfur and carbohydrate mass balances are established. 95-97 % of the charged SO(2) remains in the liquid and can be fully recovered by distillation. During fractionation, hemicelluloses and lignin are effectively dissolved, whereas cellulose is preserved in the solid (fibre) phase. Hemicelluloses are hydrolysed, producing up to 50 % monomeric sugars, whereas dehydration and oxidation of carbohydrates are insignificant. The latter is proven by the closed carbohydrate material balances as well as by the near absence of corresponding by-products (furfural, hydroxymethylfurfural (HMF) and aldonic acids). In addition, acid methanolysis/GC and acid hydrolysis/high performance anion exchange chromatography (HPAEC) methods for the carbohydrate determination are compared. PMID:22740146

  16. Measurements of NO2, SO2, NH3, HNO3 and O3 in West African urban environments

    NASA Astrophysics Data System (ADS)

    Adon, Marcellin; Yoboué, Véronique; Galy-Lacaux, Corinne; Liousse, Catherine; Diop, Babakar; Doumbia, El Hadji Thierno; Gardrat, Eric; Ndiaye, Seydi Ababacar; Jarnot, Christian

    2016-06-01

    In this paper, we present the measurements of atmospheric gas concentrations of NO2, SO2, NH3, HNO3, and O3 performed at two traffic sites in the context of the POLCA (Pollution of African Capitals) program. These gases were measured using a passive sampling technique from Jan. 2008 to Dec. 2009 at Dakar and from Jun. 2008 to Dec. 2009 at Bamako. In addition, during these periods there were two intensive measurement campaigns (from 19 Jan. to 2 Feb. 2009 at Bamako and from 30 Nov. to 13 Dec. 2009 at Dakar) where real-time active analysers were used to measure NO2 and SO2. Results show that Dakar has a pollution level for NO2 and SO2 higher than that of Bamako, whereas it is lower for NH3 concentrations. Monthly values of NO2 range between 21.1 and 43.5 ppb in Dakar with an annual mean concentration of 31.7 ppb (59.6 μg/m3). NO2 values in Bamako are 9.4-22.6 ppb with a mean of 16.2 ppb. At Dakar, the mean annual NO2 limit value (21.3 ppb or 40 μg/m3) recommended by the World Health Organization (WHO) is widely exceeded. The mean annual concentration of SO2 is 15.9 ppb in Dakar and 3.6 ppb in Bamako. These differences may be explained by different sources of traffic between Bamako (with mainly gasoline vehicles) and Dakar (with mainly diesel vehicles). The annual mean NH3 concentration is about two times higher in Bamako (46.7 ppb) than in Dakar (21.1 ppb). In addition to other possible sources, we assume that the ammonia from domestic fires and uncontrolled garbage incineration may have more influence at Bamako than at Dakar. The mean annual concentrations of HNO3 and O3 are 1.3 ppb and 7.7 ppb in Dakar and 0.6 ppb and 5.1 ppb in Bamako, respectively. Seasonal variation in measured gas concentrations are low in Bamako and more pronounced in Dakar, except for HNO3 and NH3. At Dakar, NO2 and SO2 daily mean concentrations are higher during the weekdays than on weekends, when urban activities are reduced, whereas at Bamako, no significant difference was observed

  17. Missing SO2 oxidant in the coastal atmosphere? - Evidence from high resolution measurements of OH and atmospheric sulfur compounds

    NASA Astrophysics Data System (ADS)

    Berresheim, H.; Adam, M.; Monahan, C.; O'Dowd, C.; Plane, J. M. C.; Bohn, B.; Rohrer, F.

    2014-01-01

    Diurnal and seasonal variations of gaseous sulfuric acid (H2SO4) and methane sulfonic acid (MSA) were measured in N.E. Atlantic air at the Mace Head atmospheric research station during the years 2010 and 2011. The measurements utilized selected ion/chemical ionization mass spectrometry (SI/CIMS) with a detection limit for both compounds of 4.3 × 10 4 cm-3 at 5 min signal integration. The H2SO4 and MSA gas-phase concentrations were analysed in conjunction with the condensational sink for both compounds derived from 3 nm-10 μm (diameter) aerosol size distributions. Accommodation coefficients of 1.0 for H2SO4 and 0.12 for MSA were assumed leading to estimated atmospheric lifetimes of the order of 7 min and 25 min, respectively. With the SI/CIMS instrument in OH measurement mode alternating between OH signal and background (non-OH) signal evidence was obtained for the presence of one or more unknown oxidants of SO2 in addition to OH. Depending on the nature of the oxidant(s) their ambient concentration may be enhanced in the CIMS inlet system by additional production. The apparent unknown SO2 oxidant was additionally confirmed by direct measurements of SO2 in conjunction with calculated H2SO4 concentrations. The calculated concentrations were consistently lower than the measured concentrations by a factor 4.8 ± 3.4 when considering the oxidation of SO2 by OH as the only source of H2SO4. Both the OH and the background signal were also observed to increase significantly during daytime aerosol nucleation events, independent of the ozone photolysis frequency, J(O1D), and were followed by peaks in both H2SO4 and MSA concentrations. This suggests a strong relation between the unknown oxidant(s), OH chemistry, and the atmospheric photo-oxidation of biogenic iodine compounds. As to the identity of the oxidant(s), we have been able to exclude ClO, BrO, IO, and OIO as possible candidates based on ab initio calculations. Stabilized Criegee intermediates (sCI) produced from

  18. Oxidation of CS2 and COS - sources for atmospheric SO2

    NASA Technical Reports Server (NTRS)

    Logan, J. A.; Mcelroy, M. B.; Wofsy, S. C.; Prather, M. J.

    1979-01-01

    The oxidation of COS and CS2 by reaction with hydroxyl radicals is investigated as a possible source of atmospheric SO2 in remote marine regions. Calculations of the vertical profiles of SO2 were performed based on a one-dimensional photochemical model of the formation and destruction of SO2 by various processes for observed O3, CO, CH4 and H2O profiles at 15 deg S. Variations in the rate of SO2 destruction, the chosen deposition velocity and the loss due to aerosols are shown to lead to similar SO2 profiles, which indicate higher mixing ratios at high altitude, while the oxidation of dimethyl sulfide or hydrogen sulfide can not account for the profiles observed. Possible diffuse sources of CS2 and COS are indicated, and it is concluded that the oxidation of COS and possibly CS2 may provide an explanation for the existence of a uniform background level of SO2.

  19. [Removal of SO2 from flue gas by water vapor DC corona discharge].

    PubMed

    Sun, Ming; Wu, Yan

    2006-07-01

    The influence of several factors on removal rate of SO2 from flue gas in unsaturated water vapor DC corona discharge was researched. Furthermore, the experiments of the removal rate of SO2 in pulsed discharge increased by water vapor DC corona discharge plasma were conducted. The experiment system is supplied with multi-nozzle-plate electrodes and the flow of simulated flue gas is under 70 m3/h. The results show that removal rate of SO2 can be improved by increasing the concentration of water vapor, intensity of electric field or decreasing flow of simulated flue gas. In unsaturated water vapor DC corona discharge, removal rate of SO2 can be improved by 10%, when NH3 is added as NH3 and SO2 is in a mole ratio of two to one, it can reach 60%. The removal rate of SO2 can be increased by 5% in pulsed corona discharge and reach above 90%. PMID:16881295

  20. Evidence for opioid modulation and generation of prostaglandins in sulphur dioxide (SO)2-induced bronchoconstriction.

    PubMed Central

    Field, P. I.; Simmul, R.; Bell, S. C.; Allen, D. H.; Berend, N.

    1996-01-01

    BACKGROUND: Inhalation of sulphur dioxide (SO2) provokes bronchoconstriction in asthmatic subjects. Cholinergic mechanisms contribute, but other mechanisms remain undefined. The effect of morphine, an opioid agonist, on the cholinergic component of SO2-induced bronchoconstriction was investigated, and the effect of indomethacin, a cyclooxygenase inhibitor, on SO2-induced bronchoconstriction and tachyphylaxis was studied. METHODS: In the first study 16 asthmatic subjects inhaled either ipratropium bromide or placebo 60 minutes before an SO2 challenge on days 1 and 2. On day 3 an SO2 challenge was performed immediately after intravenous morphine. In the second study 15 asthmatic subjects took either placebo or indomethacin for three days before each study day when two SO2 challenges were performed 30 minutes apart. The response was measured as the cumulative dose causing a 35% fall in specific airways conductance (sGaw; PDsGaw35). RESULTS: Ipratropium bromide significantly inhibited SO2 responsiveness, reducing PDsGaw35 by 0.89 (95% CI 0.46 to 1.31) doubling doses. This effect persisted after correction for bronchodilatation induced by ipratropium bromide. The effect of ipratropium bromide and morphine on SO2 responsiveness also correlated (r2 = 0.71). In the second study SO2 tachyphylaxis developed with PDsGaw35 on repeated testing, being reduced by 0.62 (95% CI 0.17 to 1.07) doubling doses. Indomethacin attenuated baseline SO2 responsiveness, increasing PDsGaw35 by 0.5 (95% CI 0.06 to 0.93) doubling doses. CONCLUSIONS: These results suggest that opioids modulate the cholinergic component of SO2 responsiveness and that cyclooxygenase products contribute to the immediate response to SO2. PMID:8711648

  1. The vertical distribution of volcanic SO2 plumes measured by IASI

    NASA Astrophysics Data System (ADS)

    Carboni, E.; Grainger, R. G.; Mather, T. A.; Pyle, D. M.; Thomas, G.; Siddans, R.; Smith, A.; Dudhia, A.; Koukouli, M. L.; Balis, D.

    2015-09-01

    Sulphur dioxide (SO2) is an important atmospheric constituent that plays a crucial role in many atmospheric processes. Volcanic eruptions are a significant source of atmospheric SO2 and its effects and lifetime depend on the SO2 injection altitude. The Infrared Atmospheric Sounding Instrument (IASI) on the Metop satellite can be used to study volcanic emission of SO2 using high-spectral resolution measurements from 1000 to 1200 cm-1 and from 1300 to 1410 (the 7.3 and 8.7 μm SO2 bands). The scheme described in Carboni et al. (2012) has been applied to measure volcanic SO2 amount and altitude for fourteen explosive eruptions from 2008 to 2012. The work includes a comparison with independent measurements: (i) the SO2 column amounts from the 2010 Eyjafjallajökull plumes have been compared with Brewer ground measurements over Europe; (ii) the SO2 plumes heights, for the 2010 Eyjafjallajökull and 2011 Grimsvötn eruptions, have been compared with CALIPSO backscatter profiles. The results of the comparisons show that IASI SO2 measurements are not affected by underlying cloud and are consistent (within the retrieved errors) with the other measurements. The series of analysed eruptions (2008 to 2012) show that the biggest emitter of volcanic SO2 was Nabro, followed by Kasatochi and Grímsvötn. Our observations also show a tendency for volcanic SO2 to be injected to the level of the tropopause during many of the moderately explosive eruptions observed. For the eruptions observed, this tendency was independent of the maximum amount of SO2 (e.g. 0.2 Tg for Dalafilla compared with 1.6 Tg for Nabro) and of the volcanic explosive index (between 3 and 5).

  2. Mechanisms of Heightened Airway Sensitivity and Responses to Inhaled SO2 in Asthmatics

    PubMed Central

    Reno, Anita L; Brooks, Edward G; Ameredes, Bill T

    2015-01-01

    Sulfur dioxide (SO2) is a problematic inhalable air pollutant in areas of widespread industrialization, not only in the United States but also in countries undergoing rapid industrialization, such as China, and it can be a potential trigger factor for asthma exacerbations. It is known that asthmatics are sensitive to the effects of SO2; however, the basis of this enhanced sensitivity remains incompletely understood. A PubMed search was performed over the course of 2014, encompassing the following terms: asthma, airway inflammation, sulfur dioxide, IL-10, mouse studies, and human studies. This search indicated that biomarkers of SO2 exposure, SO2 effects on airway epithelial cell function, and animal model data are useful in our understanding of the body’s response to SO2, as are SO2-associated amplification of allergic inflammation, and potential promotion of neurogenic inflammation due to chemical irritant properties. While definitive answers are still being sought, these areas comprise important foci of consideration regarding asthmatic responses to inhaled SO2. Furthermore, IL-10 deficiency associated with asthma may be another important factor associated with an inability to resolve inflammation and mitigate oxidative stress resulting from SO2 inhalation, supporting the idea that asthmatics are predisposed to SO2 sensitivity, leading to asthma exacerbations and airway dysfunction. PMID:25922579

  3. Oxidation of SO2 by NO2 and O3 on carbon - Implications to tropospheric chemistry

    NASA Technical Reports Server (NTRS)

    Cofer, W. R., III; Schryer, D. R.; Rogowski, R. S.

    1984-01-01

    The oxidation of SO2 to sulfate in air at 65 percent relative humidity on carbon particles was investigated gravimetrically in the presence of NO2 and O3. Approximately 1 mg samples of carbon black were exposed to continuously flowing ppbv mixtures of SO2, SO2 + NO2 and SO2 + O3 for prescribed periods of time before desorption into dry N2. Wet chemical analysis of the particles followed desorption. NO2 and O3 were found to have little, if any, effect relative to air on sulfate yields at the concentrations studied.

  4. The global distribution, abundance, and stability of SO2 on Io

    NASA Technical Reports Server (NTRS)

    Mcewen, Alfred S.; Soderblom, Laurence A.; Johnson, Torrence V.; Matson, Dennis L.

    1988-01-01

    Voyager multispectral mosaics, earth-observed spectra, and photometric characterizations have been used to model and globally map the SO2 distribution and abundances, the bolometric hemispheric albedos, and the passive surface temperatures on Io. The SO2 is noted to be concentrated in the bright equatorial band, while being deficient in the region defined by Pele-type volcanic eruptions and the polar regions. The brightest, locally coldest areas correspond to SO2-rich regions, although many small patches occur elsewhere. These results are found to support the regional cold-trapping model for the surface and atmospheric SO2 of Fanale et al. (1982).

  5. Uncovering microRNA-mediated response to SO2 stress in Arabidopsis thaliana by deep sequencing.

    PubMed

    Li, Lihong; Xue, Meizhao; Yi, Huilan

    2016-10-01

    Sulfur dioxide (SO2) is a major air pollutant and has significant impacts on plants. MicroRNAs (miRNAs) are a class of gene expression regulators that play important roles in response to environmental stresses. In this study, deep sequencing was used for genome-wide identification of miRNAs and their expression profiles in response to SO2 stress in Arabidopsis thaliana shoots. A total of 27 conserved miRNAs and 5 novel miRNAs were found to be differentially expressed under SO2 stress. qRT-PCR analysis showed mostly negative correlation between miRNA accumulation and target gene mRNA abundance, suggesting regulatory roles of these miRNAs during SO2 exposure. The target genes of SO2-responsive miRNAs encode transcription factors and proteins that regulate auxin signaling and stress response, and the miRNAs-mediated suppression of these genes could improve plant resistance to SO2 stress. Promoter sequence analysis of genes encoding SO2-responsive miRNAs showed that stress-responsive and phytohormone-related cis-regulatory elements occurred frequently, providing additional evidence of the involvement of miRNAs in adaption to SO2 stress. This study represents a comprehensive expression profiling of SO2-responsive miRNAs in Arabidopsis and broads our perspective on the ubiquitous regulatory roles of miRNAs under stress conditions. PMID:27232729

  6. Adsorption of SO2 on bituminous coal char and activated carbon fiber

    USGS Publications Warehouse

    DeBarr, J.A.; Lizzio, A.A.; Daley, M.A.

    1997-01-01

    The SO2 adsorption behaviors of activated carbons produced from Illinois coal and of commercially prepared activated carbon fibers (ACFs) were compared. There was no relation between surface area of coal-based carbons and SO2 adsorption, whereas adsorption of SO2 on the series of ACFs was inversely proportional to N2 BET surface area. Higher surface area ACFs had wider pores and adsorbed less SO2; thus, pore size distribution is thought to play a significant role in SO2 adsorption for these materials. Oxidation with HNO3 and/or H2SO4, followed by heat treatment at 700-925 ??C to remove carbon-oxygen complexes, resulted in increased SO2 adsorption for both coal chars and ACFs. This behavior was explained by an increase in the available number of free sites, previously occupied by oxygen and now available for SO2 adsorption. The use of nitrogen-containing functional groups on ACFs of proper pore size shows promise for further increasing SO2 adsorption capacities. Knowledge of the relationship among the number of free sites, pore size, and surface chemistry on corresponding SO2 adsorption should lead to the development of more efficient adsorbents prepared from either coal or ACFs.

  7. OMI measurements of SO2 pollution over Eastern China in 2005-2008

    NASA Astrophysics Data System (ADS)

    Krotkov, N.; Pickering, K.; Witte, J.; Carn, S.; Yang, K.; Carmichael, G.; Streets, D.; Zhang, Q.; Wei, C.

    2009-05-01

    The Ozone Monitoring Instrument (OMI) on NASA Aura satellite makes global daily measurements of the total column of sulfur dioxide (SO2), a short-lived trace gas produced by fossil fuel combustion, smelting, and volcanoes. OMI seasonal to multi-year average images clearly show the world-highest consistent SO2 pollution in northeast China. China is the world's largest SO2 emitter, mostly due to the burning of high-sulfur coal in its many coal-fired power plants, which lack the technology used in many other countries to remove sulfur from smoke stack emissions. China's government has instituted nationwide measures to control SO2 emissions through the adoption of flue-gas desulfurization technology on new power plants; and even greater measures were adopted in the Beijing area in anticipation of the Olympic Games. To study the environmental effects of the emission controls we compared OMI SO2 time series over eastern China for 2005 through 2008. The time series have been done as 7-day running means of the cloud-free daily observations. By mid-March we started to see substantial periods of lower SO2 values in 2008 compared to 2007, and by mid June the 2008 values were consistently lower than 2007 and prior years. The decline is widespread with highest SO2 typically located to the south and southwest of Beijing in regions with large clusters of power plants and also around Shanghai. The decline also lasted beyond the Olympic season. We do not yet know to what extent the economic downturn in China (and reduced industrial production) contributed to lower SO2 levels in the fall of 2008. We have also compared the observed and modeled fields using University of Iowa STEM model for the period June - September 2008. The model provided SO2 vertical distributions as well as aerosol vertical profiles that were used to correct OMI operational SO2 retrievals and improve the comparisons. The OMI SO2 changes in 2008 have also been compared with the estimated changes in SO2 emissions

  8. The use of IASI in the measurement of volcanic SO2: degassing and lower tropospheric emission.

    NASA Astrophysics Data System (ADS)

    Carboni, Elisa; Grainger, Roy G.; Hayer, Catherine; Mater, Tamsin A.; Preston, James; Theys, Nicolas; Hidalgo, Silvana

    2016-04-01

    Sulphur dioxide (SO2) is an important atmospheric constituent that plays a crucial role in many atmospheric processes. Volcanic eruptions are a significant source of atmospheric SO2 and its lifetime and impact depend on the SO2 injection altitude. Measurements of volcanic SO2 emissions can offer critical insight into the current and near-future activity of volcanoes, however, the majority of active volcanoes lack regular ground-based monitoring. We exploit the spectral range of IASI, from 1000 to 1200 cm‑1 and from 1300 to 1410 cm‑1 (the 7.3 and 8.7 μm SO2 absorption bands), to study volcanic SO2. The IASI-A dataset was analysed using a rapid linear retrieval algorithm as a global survey tool to show that IASI observations detect SO2 emissions from anthropogenic sources, volcanic eruptions and certain persistently degassing volcanoes over the IASI time series. Using this linear retrieval hundreds of potential degassing volcanoes are identified around the world. An iterative optimal estimation retrieval scheme was then employed to produce a more detailed analysis of the data, with a comprehensive error budget. This algorithm is significantly more computationally intensive but allows for the estimation of both the SO2 amount and altitude of volcanic plume from recent explosive and effusive eruptions. Thermal infrared spectrometers are particularly valuable in regions where shorter wavelength observations are limited, such as during polar winter. In particular here we present two case studies: 1) The vertical distribution of SO2 during the Bardabunga eruption from September 2014 to February 2015. 2) The monthly mean trends in SO2 emission over Ecuador and Northern Kamchatka. Over Ecuador, Tungurahua showed the most persistent signal, with a strong correlation between IASI, ground-based and OMI datasets. Over Kamchatka, IASI detected clear peaks in SO2 emissions coincident with reports of elevated volcanic activity.

  9. Measurements of Acetic Acid and its Relationships with Trace Gases on Appledore Island, ME during the ICARTT Campaign

    NASA Astrophysics Data System (ADS)

    Haase, K. B.; Sive, B. C.; White, M. L.; Russo, R. S.; Ambrose, J. L.; Zhou, Y.; Talbot, R. W.

    2011-12-01

    Acetic acid is ubiquitously present in the ambient atmosphere. Acetic acid, along with formic acid, is the one of the most abundant gas phase organic acids with mixing ratios reaching into the tens of parts per billion by volume (ppbv) range, and can influence the pH of aerosols and precipitation. The magnitude of the sources and sinks of acetic acid in the environment is not well understood (~24 Tg/yr of missing emissions globally), as they are widely dispersed and measurements are relatively challenging to accomplish using established techniques. Here, the application of Proton Transfer Reaction Mass Spectrometry (PTR-MS) is explored as a technique for quantification of ambient acetic acid. Direct calibrations of PTR-MS instruments at low ppbv levels show good linearity and fast response, and during the ICARTT campaign, a PTR-MS measured acetic acid and a suite of other volatile organic compounds on Appledore Island, ME over a period of 6 weeks. During the campaign, the average mixing ratio of acetic acid on the island was 607.9 ± 341.8 (1σ) pptv with a median of 530 pptv. Mixing ratios of acetic acid observed on the island showed diurnal variations corresponding land breeze/sea breeze transport, similar to other pollutants including ozone and carbon monoxide, indicating that acetic acid was advected to the sample site, and not a product of local emissions. Additionally, no mixing ratio dependence on wind speed was found, indicating that at this location, loss due to dry deposition to the ocean during transport was minimal. Over the course of the campaign, acetic acid showed complex relationships with a range of other VOCs, indicating a diverse set of sources and further showing the utility of the PTR-MS technique for monitoring acetic acid. Mixing ratios of acetic acid showed correlations with different compounds at different times, indicating a complex source signature comprised of (1) anthropogenic emissions, (2) biomass burning, and (3) photochemical

  10. Mid-infrared detection of large longitudinal asymmetries in Io's SO 2 atmosphere

    NASA Astrophysics Data System (ADS)

    Spencer, John R.; Lellouch, Emmanuel; Richter, Matthew J.; López-Valverde, Miguel A.; Lea Jessup, Kandis; Greathouse, Thomas K.; Flaud, Jean-Marie

    2005-08-01

    -wavelength spectroscopy. This longitudinal variability in atmospheric density correlates with the longitudinal variability in the abundance of optically thick, near-UV bright SO 2 frost. However it is not clear whether the correlation results from volcanic control (regions of large frost abundance result from greater condensation of atmospheric gases supported by more vigorous volcanic activity in these regions) or sublimation control (regions of large frost abundance produce a more extensive atmosphere due to more extensive sublimation). Comparison of data taken in 2001, 2002, and 2004 shows that with the possible exception of longitudes near 180° W between 2001 and 2002, Io's atmospheric density does not appear to decrease as Io recedes from the Sun, as would be expected if the atmosphere were supported by the sublimation of surface frost, suggesting that the atmosphere is dominantly supported by direct volcanic supply rather than by frost sublimation. However, other evidence such as the smooth variation in atmospheric abundance with latitude, and atmospheric changes during eclipse, suggest that sublimation support is more important than volcanic support, leaving the question of the dominant atmospheric support mechanism still unresolved.

  11. $\\frac{{\\rm SO}(2N)}{U(N)}$ Riccati-Hartree-Bogoliubov equation based on the SO(2N) Lie algebra of the fermion operators

    NASA Astrophysics Data System (ADS)

    Nishiyama, Seiya; da Providência, João

    2015-02-01

    In this paper we present the induced representation of SO(2N) canonical transformation group and introduce (SO(2N))/(U(N)) coset variables. We give a derivation of the time-dependent Hartree-Bogoliubov (TDHB) equation on the Kähler coset space (G)/(H) = (SO(2N))/(U(N)) from the Euler-Lagrange equation of motion for the coset variables. The TDHB wave function represents the TD behavior of Bose condensate of fermion pairs. It is a good approximation for the ground state of the fermion system with a pairing interaction, producing the spontaneous Bose condensation. To describe the classical motion on the coset manifold, we start from the local equation of motion. This equation becomes a Riccati-type equation. After giving a simple two-level model and a solution for a coset variable, we can get successfully a general solution of time-dependent Riccati-Hartree-Bogoliubov equation for the coset variables. We obtain the Harish-Chandra decomposition for the SO(2N) matrix based on the nonlinear Möbius transformation together with the geodesic flow on the manifold.

  12. Development and testing of a PEM SO2-depolarized electrolyzer and an operating method that prevents sulfur accumulation

    DOE PAGESBeta

    Steimke, John L.; Steeper, Timothy J.; Colon-Mercado, Hector R.; Gorensek, Maximilian B.

    2015-09-02

    The hybrid sulfur (HyS) cycle is being developed as a technology to generate hydrogen by splitting water, using heat and electrical power from a nuclear or solar power plant. A key component is the SO2-depolarized electrolysis (SDE) cell, which reacts SO2 and water to form hydrogen and sulfuric acid. SDE could also be used in once-through operation to consume SO2 and generate hydrogen and sulfuric acid for sale. A proton exchange membrane (PEM) SDE cell based on a PEM fuel cell design was fabricated and tested. Measured cell potential as a function of anolyte pressure and flow rate, sulfuric acidmore » concentration, and cell temperature are presented for this cell. Sulfur accumulation was observed inside the cell, which could have been a serious impediment to further development. A method to prevent sulfur formation was subsequently developed. As a result, this was made possible by a testing facility that allowed unattended operation for extended periods.« less

  13. Recovery of SO2 and MgO from By-Products of MgO Wet Flue Gas Desulfurization

    PubMed Central

    Yan, Liyun; Lu, Xiaofeng; Wang, Quanhai; Guo, Qiang

    2014-01-01

    Abstract An industrial demonstration unit using natural gas as a heat source was built to calcine the by-products of MgO wet flue gas desulfurization from power plants; influencing factors on the SO2 content in calciner gas were comprehensively analyzed; and an advantageous recycling condition of MgO and SO2 from by-products was summarized. Results showed that the SO2 content in the calciner gas was increased by more than 10 times under a lower excess air coefficient, a higher feed rate, a lower crystal water in by-products, and a higher feed port position. For the tests conducted under the excess air coefficient above and below one, the effect of the furnace temperature on the SO2 content in the calciner gas was reversed. Results of activity analysis indicate that particles of MgO generated under the calcination temperature of 900–1,000°C had a high activity. In contrast, due to the slight sintering, MgO generated under the calcination temperature of 1,100°C had a low activity. To recycle SO2 as well as MgO, a temperature range of 900–927°C for TE103 is proposed. These studies will prompt the desulfurization market diversification, reduce the sulfur's dependence on imports for making sulfuric acid, be meaningful to balance the usage of the natural resource in China, and be regarded as a reference for the development of this technology for other similar developing countries. PMID:25371652

  14. Recovery of SO2 and MgO from By-Products of MgO Wet Flue Gas Desulfurization.

    PubMed

    Yan, Liyun; Lu, Xiaofeng; Wang, Quanhai; Guo, Qiang

    2014-11-01

    An industrial demonstration unit using natural gas as a heat source was built to calcine the by-products of MgO wet flue gas desulfurization from power plants; influencing factors on the SO2 content in calciner gas were comprehensively analyzed; and an advantageous recycling condition of MgO and SO2 from by-products was summarized. Results showed that the SO2 content in the calciner gas was increased by more than 10 times under a lower excess air coefficient, a higher feed rate, a lower crystal water in by-products, and a higher feed port position. For the tests conducted under the excess air coefficient above and below one, the effect of the furnace temperature on the SO2 content in the calciner gas was reversed. Results of activity analysis indicate that particles of MgO generated under the calcination temperature of 900-1,000°C had a high activity. In contrast, due to the slight sintering, MgO generated under the calcination temperature of 1,100°C had a low activity. To recycle SO2 as well as MgO, a temperature range of 900-927°C for TE103 is proposed. These studies will prompt the desulfurization market diversification, reduce the sulfur's dependence on imports for making sulfuric acid, be meaningful to balance the usage of the natural resource in China, and be regarded as a reference for the development of this technology for other similar developing countries. PMID:25371652

  15. Calculated rate constants of the chemical reactions involving the main byproducts SO2F, SOF2, SO2F2 of SF6 decomposition in power equipment

    NASA Astrophysics Data System (ADS)

    Fu, Yuwei; Rong, Mingzhe; Yang, Kang; Yang, Aijun; Wang, Xiaohua; Gao, Qingqing; Liu, Dingxin; Murphy, Anthony B.

    2016-04-01

    SF6 is widely used in electrical equipment as an insulating gas. In the presence of an electric arc, partial discharge (PD) or spark, SF6 dissociation products (such as SF2, SF3 and SF4) react with the unavoidable gas impurities (such as water vapor and oxygen), electrodes and surrounding solid insulation materials, forming several toxic and corrosive byproducts. The main stable decomposition products are SO2F, SO2F2 and SOF2, which have been confirmed experimentally to have a direct relationship with discharge faults, and are thus expected to be useful in the fault diagnosis of power equipment. Various studies have been performed of the main SF6 decomposition species and their concentrations under different types of faults. However, most of the experiments focused on the qualitative analysis of the relationship between the stable products and discharge faults. Although some theoretical research on the formation of main SF6 derivatives have been carried out using chemical kinetics models, the basic data (chemical reactions and their rate constants) adopted in the model are inaccurate and incomplete. The complex chemical reactions of SF6 with the impurities are ignored in most cases. The rate constants of some reactions obtained at ambient temperature or in a narrow temperature range are adopted in the models over a far greater range, for example up to 12 000 K, due to the difficulty in the experimental measurement and theoretical estimation of rate coefficients, particularly at high temperatures. Therefore, improved theoretical models require not only the consideration of additional SF6 decomposition reactions in the presence of impurities but also on improved values of rate constants. This paper is devoted to determining the rate constants of the chemical reactions relating to the main byproducts of SF6 decomposition in SF6 gas-insulated power equipment: SO2F, SOF2 and SO2F2. Quantum chemistry calculations with density functional theory, conventional

  16. 40 CFR 97.253 - Recordation of CAIR SO2 allowances.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Recordation of CAIR SO2 allowances. 97.253 Section 97.253 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Tracking System § 97.253 Recordation of CAIR SO2 allowances. (a)(1) After a compliance account...

  17. 40 CFR 97.253 - Recordation of CAIR SO2 allowances.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Recordation of CAIR SO2 allowances. 97.253 Section 97.253 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Tracking System § 97.253 Recordation of CAIR SO2 allowances. (a)(1) After a compliance account...

  18. 40 CFR 97.253 - Recordation of CAIR SO2 allowances.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Recordation of CAIR SO2 allowances. 97.253 Section 97.253 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Tracking System § 97.253 Recordation of CAIR SO2 allowances. (a)(1) After a compliance account...

  19. 40 CFR 97.253 - Recordation of CAIR SO2 allowances.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Recordation of CAIR SO2 allowances. 97.253 Section 97.253 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Tracking System § 97.253 Recordation of CAIR SO2 allowances. (a)(1) After a compliance account...

  20. 40 CFR 74.25 - Current promulgated SO 2 emissions limit.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Current promulgated SO 2 emissions... PROGRAMS (CONTINUED) SULFUR DIOXIDE OPT-INS Allowance Calculations for Combustion Sources § 74.25 Current promulgated SO 2 emissions limit. The designated representative shall submit the following data: (a)...

  1. 40 CFR 74.25 - Current promulgated SO2 emissions limit.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Current promulgated SO2 emissions... PROGRAMS (CONTINUED) SULFUR DIOXIDE OPT-INS Allowance Calculations for Combustion Sources § 74.25 Current promulgated SO2 emissions limit. The designated representative shall submit the following data: (a)...

  2. 40 CFR 74.25 - Current promulgated SO 2 emissions limit.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Current promulgated SO 2 emissions... PROGRAMS (CONTINUED) SULFUR DIOXIDE OPT-INS Allowance Calculations for Combustion Sources § 74.25 Current promulgated SO 2 emissions limit. The designated representative shall submit the following data: (a)...

  3. 40 CFR 74.24 - Current allowable SO 2 emissions rate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Current allowable SO 2 emissions rate... PROGRAMS (CONTINUED) SULFUR DIOXIDE OPT-INS Allowance Calculations for Combustion Sources § 74.24 Current allowable SO 2 emissions rate. The designated representative shall submit the following data: (a)...

  4. 40 CFR 74.24 - Current allowable SO 2 emissions rate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Current allowable SO 2 emissions rate... PROGRAMS (CONTINUED) SULFUR DIOXIDE OPT-INS Allowance Calculations for Combustion Sources § 74.24 Current allowable SO 2 emissions rate. The designated representative shall submit the following data: (a)...

  5. 40 CFR 74.24 - Current allowable SO2 emissions rate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Current allowable SO2 emissions rate... PROGRAMS (CONTINUED) SULFUR DIOXIDE OPT-INS Allowance Calculations for Combustion Sources § 74.24 Current allowable SO2 emissions rate. The designated representative shall submit the following data: (a)...

  6. 40 CFR 74.24 - Current allowable SO2 emissions rate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Current allowable SO2 emissions rate... PROGRAMS (CONTINUED) SULFUR DIOXIDE OPT-INS Allowance Calculations for Combustion Sources § 74.24 Current allowable SO2 emissions rate. The designated representative shall submit the following data: (a)...

  7. 40 CFR 74.25 - Current promulgated SO2 emissions limit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Current promulgated SO2 emissions... PROGRAMS (CONTINUED) SULFUR DIOXIDE OPT-INS Allowance Calculations for Combustion Sources § 74.25 Current promulgated SO2 emissions limit. The designated representative shall submit the following data: (a)...

  8. 40 CFR 74.24 - Current allowable SO2 emissions rate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Current allowable SO2 emissions rate... PROGRAMS (CONTINUED) SULFUR DIOXIDE OPT-INS Allowance Calculations for Combustion Sources § 74.24 Current allowable SO2 emissions rate. The designated representative shall submit the following data: (a)...

  9. 40 CFR 74.25 - Current promulgated SO2 emissions limit.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Current promulgated SO2 emissions... PROGRAMS (CONTINUED) SULFUR DIOXIDE OPT-INS Allowance Calculations for Combustion Sources § 74.25 Current promulgated SO2 emissions limit. The designated representative shall submit the following data: (a)...

  10. LONG-RANGE TRANSPORT AND TRANSFORMATION OF SO2 AND SULFATE

    EPA Science Inventory

    Technical descriptions and computer programs are presented for two models that calculate long-range transport, diffusion, transformation of SO2 to sulfate, and dry and precipitation deposition of initially emitted SO2. One model treats the mixing layer height as constant; the oth...

  11. Next Generation Aura-OMI SO2 Retrieval Algorithm: Introduction and Implementation Status

    NASA Technical Reports Server (NTRS)

    Li, Can; Joiner, Joanna; Krotkov, Nickolay A.; Bhartia, Pawan K.

    2014-01-01

    We introduce our next generation algorithm to retrieve SO2 using radiance measurements from the Aura Ozone Monitoring Instrument (OMI). We employ a principal component analysis technique to analyze OMI radiance spectral in 310.5-340 nm acquired over regions with no significant SO2. The resulting principal components (PCs) capture radiance variability caused by both physical processes (e.g., Rayleigh and Raman scattering, and ozone absorption) and measurement artifacts, enabling us to account for these various interferences in SO2 retrievals. By fitting these PCs along with SO2 Jacobians calculated with a radiative transfer model to OMI-measured radiance spectra, we directly estimate SO2 vertical column density in one step. As compared with the previous generation operational OMSO2 PBL (Planetary Boundary Layer) SO2 product, our new algorithm greatly reduces unphysical biases and decreases the noise by a factor of two, providing greater sensitivity to anthropogenic emissions. The new algorithm is fast, eliminates the need for instrument-specific radiance correction schemes, and can be easily adapted to other sensors. These attributes make it a promising technique for producing long-term, consistent SO2 records for air quality and climate research. We have operationally implemented this new algorithm on OMI SIPS for producing the new generation standard OMI SO2 products.

  12. 40 CFR 74.23 - 1985 Allowable SO2 emissions rate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) SULFUR DIOXIDE OPT-INS Allowance Calculations for Combustion Sources § 74.23 1985 Allowable SO2 emissions rate. (a) Data requirements. (1) The designated representative of the combustion source shall... data: (i) Allowable SO2 emissions rate of the combustion source expressed in lbs/mmBtu as defined...

  13. MODELING OF SO2 REMOVAL IN SPRAY-DRYER FLUE-GAS DESULFURIZATION SYSTEM

    EPA Science Inventory

    The report presents a comprehensive mathematical model of the SO2 removal process in a spray-dryer flue-gas desulfurization system. Simultaneous evaporation of a sorbent droplet and absorption/reaction of SO2 in the droplet are described by the corresponding heat- and mass-transf...

  14. PHYTOTOXICITY OF AIR POLLUTANTS. EVIDENCE FOR THE PHOTODETOXIFICATION OF SO2 BUT NOT O3

    EPA Science Inventory

    Pisum sativum L. cv Alsweet (garden pea) and Lycopersicon esculentum flacca Mill. (tomato) were used to evaluate the phytotoxicity of SO2 and O3 in the light and dark. Plants were grown in controlled environment chambers and exposed to SO2 or O3 in the light or dark at the same e...

  15. INTERSPECFIC VARIATION IN SO2 FLUX - LEAF SURFACE 'VERSUS' INTERNAL FLUX, AND COMPONENTS OF LEAF CONDUCTANCE

    EPA Science Inventory

    The object of the study was to clarify the relationships among stomatal, residual, and epidermal conductances in determining the flux of SO2 air pollution to leaves. Variations in leaf SO2 and H2O vapor fluxes were determined using four plant species: Pisum sativum L. (garden pea...

  16. 40 CFR 60.43Da - Standard for sulfur dioxide (SO2).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for sulfur dioxide (SO2). 60... for sulfur dioxide (SO2). (a) On and after the date on which the initial performance test is completed... reduction requirement is determined on a 24-hour basis. (d) Sulfur dioxide emissions are limited to 520...

  17. 77 FR 26444 - Revisions to Final Response To Petition From New Jersey Regarding SO2

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-04

    ... Portland Generating Station'' published on November 7, 2011. See 76 FR 69052. We initially proposed this... Regarding SO 2 Emissions From the Portland Generating Station'' published on December 22, 2011. See 76 FR... Jersey Regarding SO 2 Emissions From the Portland Generating Station'' (76 FR 69052) contain...

  18. GROWTH RESPONSE IN SPINACH TO SEQUENTIAL AND SIMULTANEOUS EXPOSURE TO NO2 AND SO2

    EPA Science Inventory

    Spinach (Spinacia oleracea) was exposed intermittently to NO2 and SO2 (2 hours/week; 0.8 or 1.5ppm) in a simultaneous or sequential fashion over the 42-day growth period. Nighttime simultaneous exposure to NO2 and SO2 reduced growth and altered assimilate partitioning to the root...

  19. USE OF COAL CLEANING FOR COMPLIANCE WITH SO2 EMISSION REGULATIONS

    EPA Science Inventory

    The report gives results of an evaluation of coal cleaning as a means of controlling SO2 emissions from coal-fired stationary sources. Coal cleaning was examined in the light of various existing and proposed SO2 emissions regulations to determine applications in which the technol...

  20. 40 CFR 60.43Da - Standard for sulfur dioxide (SO2).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for sulfur dioxide (SO2). 60... for sulfur dioxide (SO2). (a) On and after the date on which the initial performance test is completed... reduction requirement is determined on a 24-hour basis. (d) Sulfur dioxide emissions are limited to 520...

  1. 40 CFR 60.43Da - Standards for sulfur dioxide (SO2).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for sulfur dioxide (SO2). 60... Steam Generating Units § 60.43Da Standards for sulfur dioxide (SO2). (a) On and after the date on which... the percent reduction requirement is determined on a 24-hour basis. (d) Sulfur dioxide emissions...

  2. 40 CFR 60.43Da - Standards for sulfur dioxide (SO2).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for sulfur dioxide (SO2). 60... Steam Generating Units § 60.43Da Standards for sulfur dioxide (SO2). (a) On and after the date on which... the percent reduction requirement is determined on a 24-hour basis. (d) Sulfur dioxide emissions...

  3. 40 CFR 60.43Da - Standards for sulfur dioxide (SO2).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for sulfur dioxide (SO2). 60... Steam Generating Units § 60.43Da Standards for sulfur dioxide (SO2). (a) On and after the date on which... the percent reduction requirement is determined on a 24-hour basis. (d) Sulfur dioxide emissions...

  4. Variations of the BrO/SO2 ratios from Tungurahua volcano, Ecuador

    NASA Astrophysics Data System (ADS)

    Warnach, Simon; Lübcke, Peter; Dinger, Florian; Bobrowski, Nicole; Hidalgo, Silvana; Arellano, Santiago; Battaglia, Jean; Galle, Bo; Hörmann, Christoph; Ruiz, Mario; Vogel, Leif; Wagner, Thomas; Platt, Ulrich

    2016-04-01

    The amount and composition of volcanic gas emissions can yield information about magmatic processes. Apart from the SO2 emission rate, which is used as a widespread tool in monitoring volcanoes, the molar ratio of BrO/SO2 in a volcanic plume has shown the potential for interpreting volcanic activity. The evaluation of long-term spectral data collected with UV-scanning spectrometers through the Network for Observation of Volcanic and Atmospheric Change (NOVAC) using the DOAS technique can help to obtain a better understanding of the BrO/SO2 molar ratio and its correlation to magmatic processes. BrO and SO2 emissions as well as the BrO/SO2 ratio have been successfully retrieved from NOVAC data at Nevado del Ruiz (Colombia), where a decrease of the BrO/SO2 ratio was observed prior to a large eruption. We apply this evaluation algorithm to determine the plume composition of Tungurahua volcano, Ecuador, which is part of NOVAC since 2007. Different from Nevado del Ruiz the retrieved column densities of SO2 and BrO at Tungurahua are typically more than a factor of two lower during the respective period of observation. In addition, changes in the volcanic activity appear on a smaller timescale, as Tungurahua displays a succession of activity and quiescence phases. In order to still obtain robust BrO/SO2 ratios at Tungurahua, it is necessary to improve the data evaluation as well as applying a more sophisticated scheme to calculate the BrO/SO2 ratio. By combining both methods we create a time series of the BrO/SO2 ratio for several eruptive phases between 2007 and 2014. The ratio shows values between 2 and 8 × 10‑5. The variation of the BrO/SO2 ratio during these eruptive phases is compared to seismic data and volcanological phenomenological observations as well as satellite and ground based SO2 measurements. During several eruptive phases we observe an increase in the BrO/SO2 ratio on the transition from high explosive activity to low explosive activity. During the

  5. The 2014 Holuhraun volcanic eruption gas emission: a case study of an extreme SO2 concentration event

    NASA Astrophysics Data System (ADS)

    Björk Jónasdóttir, Elín; Nína Petersen, Guðrún; Björnsson, Halldór; Pfeffer, Melissa Anne; Barsotti, Sara; Jóhannsson, Þorsteinn; Dürig, Tobias

    2015-04-01

    The ongoing fissure eruption in Holuhraun associated with the volcanic unrest in Bárðarbunga, is unique among recent eruptions in Iceland for its high emission rates of volcanic gases. The plume is relatively ash free, but predominantly a bent over vapour plume and its height depends mainly on the atmospheric conditions at the eruption site. CO2 and SO2 are abundant in the primarily water vapor plume with lower concentrations of H2S, HCl and HF. During the first month and a half the preliminary SO2 flux was ~400 kg/s with some days greater than 1000 kg/s. The gas is dispersed from the eruption and transported by wind, and can lead to high pollution levels in exposed populated areas in Iceland. During high wind events and when nearby weather systems lead to rapid change in wind directions the local population has not been much affected by the emission, as the gas is transported off land and/or the pollution plume is narrow and moves around. However, during certain conditions, usually light winds and low-level temperature inversions, the concentration of gas builds up at the eruption site and then either flows down from the highlands with katabatic wind or is advected from the eruption site when the synoptic situation changes. Depending on the atmospheric conditions, high concentrations of SO2 can be transported in the boundary layer and have been detected at ground level in populated areas. Here we describe one such event, the event of 26 and 27 October 2014, when the village Höfn, in southeast-Iceland, experienced gas concentrations exceeding 14000 µg/m3, a concentration considered hazardous to health. We describe the weather conditions prior and during the event as well as the gas dispersion.

  6. Removal of SO2 from O2-containing flue gas by activated carbon fiber (ACF) impregnated with NH3.

    PubMed

    Xu, Lüsi; Guo, Jia; Jin, Feng; Zeng, Hancai

    2006-02-01

    Adsorption of SO(2) from the O(2)-containing flue gas by granular activated carbons (GACs) and activated carbon fibers (ACFs) impregnated with NH(3) was studied in this technical note. Experimental results showed that the ACFs were high-quality adsorbents due to their unique textural properties. In the presence of moisture, the desulphurization efficiency for the ACFs was improved significantly due to the formation of sulfuric acid. After NH(3) impregnation of ACF samples, nitrogen-containing functional groups (pyridyl C(5)H(4)N- and pyrrolyl C(4)H(4)N-) were detected on the sample surface by using an X-ray photoelectron spectrometer. These functional groups accounted for the enhanced SO(2) adsorption via chemisorption and/or catalytic oxidization. PMID:15982716

  7. Si-doped graphene: A promising metal-free catalyst for oxidation of SO2

    NASA Astrophysics Data System (ADS)

    Esrafili, Mehdi D.; Saeidi, Nasibeh; Nematollahi, Parisa

    2016-04-01

    This study reports favorable reaction mechanisms of SO2 oxidation by molecular O2 over Si-doped graphene by means of DFT calculations. The SO2 oxidation reaction proceeds through the following elementary steps (a) SO2 + O2 → Oads + SO3 and (b) Oads + SO2 → SO3. It is found that the first and second steps are fulfilled via the Langmuir-Hinshelwood (LH) and Eley-Rideal (ER) mechanisms, with an activation energy of 4.7 and 9.5 kcal/mol, respectively. Results show that the low-cost Si-doped graphene can be used as an efficient catalyst for SO2 oxidation at room temperature.

  8. SO2 frost - UV-visible reflectivity and Io surface coverage

    NASA Technical Reports Server (NTRS)

    Nash, D. B.; Fanale, F. P.; Nelson, R. M.

    1980-01-01

    The reflectance spectrum in the range 0.24-0.85 microns of SO2 frost is measured in light of the discovery of SO2 gas in the atmosphere of Io and the possible discovery of the frost on its surface. Frost deposits up to 1.5 mm thick were grown in vacuum at 130 K and bi-directional reflectance spectra were obtained. Typical SO2 frost is found to exhibit very low reflectivity (2-5%) at 0.30 microns, rising steeply at 0.32 microns to attain a maximum reflectivity (75-80%) at 4.0 microns and uniformly high reflectivity throughout the visible and near infrared. Comparison with the full disk spectrum of Io reveals that no more than 20% of the surface can be covered with optically thick SO2 frost. Combinations of surface materials including SO2 frost which can produce the observed spectrum are indicated.

  9. A New Method to Improve the Precision of SO2Measurement in Atmosphere

    NASA Astrophysics Data System (ADS)

    Gong, R. K.; Chen, L.; Nian, S. P.

    2006-10-01

    The thesis discusses the status quo and existent problems of SO2 measurement, explores sensor mechanism of measurement precision of SO2, and deduces the mathematical measurement model of SO2 according to Lambert-Beer Law. Aiming at the nonlinearity problem existing in the mathematical model, it employs Taylor's series expansion to resolve the problem. In addition, it designs the gas room of double optical paths to measure SO2 by infrared, which utilizes four detectors to eliminate the impact of CO2 and disturbed noise by receiving signals. Finally, through the analysis of the experimental data, it proves that this method has such features as easy implementation, high precision, strong anti-jamming capability, and real-time and on-line measurement of SO2required in the industry field.

  10. Carbon catalyzed SO2 oxidation by NO2 and O3

    NASA Technical Reports Server (NTRS)

    Cofer, W. R., III; Schryer, D. R.; Rogowski, R. S.

    1982-01-01

    The oxidation of SO2 to sulfate on carbon particles by trace quantities of NO2 and O3 was studied. Particulate carbon black was either: (1) directly exposed on the pan of a microbalance to various humidified mixtures of SO2 and oxidant gas and the resultant weight gains monitored, or (2) the gas mixtures were bubbled through aqueous suspensions of carbon black and pure water blanks. In each set of experiments the run times were varied appropriately and the yields of sulfate were determined analytically. Conversion of SO2 to sulfate was thus characterized as a function of exposure time and of oxidant gas. Carbon black was determined to be an excellent catalyst for SO2 oxidation to sulfate by both NO2 and O3. No saturation effects were observed in either experimental approach. Conversions of SO2 to sulfate did not appear pH dependent.

  11. Laboratory study of SO2 dry deposition on limestone and marble: Effects of humidity and surface variables

    USGS Publications Warehouse

    Spiker, E. C.; Hosker, R.P., Jr.; Weintraub, V.C.; Sherwood, S.I.

    1995-01-01

    The dry deposition of gaseous air pollutants on stone and other materials is influenced by atmospheric processes and the chemical characteristics of the deposited gas species and of the specific receptor material. Previous studies have shown that relative humidity, surface moisture, and acid buffering capability of the receptor surface are very important factors. To better quantify this behavior, a special recirculating wind tunnel/environmental chamber was constructed, in which wind speed, turbulence, air temperature, relative humidity, and concentrations of several pollutants (SO2, O3, nitrogen oxides) can be held constant. An airfoil sample holder holds up to eight stone samples (3.8 cm in diameter and 1 cm thick) in nearly identical exposure conditions. SO2 deposition on limestone was found to increase exponentially with increasing relative humidity (RH). Marble behaves similarly, but with a much lower deposition rate. Trends indicate there is little deposition below 20% RH on clean limestone and below 60% RH on clean marble. This large difference is due to the limestone's greater porosity, surface roughness, and effective surface area. These results indicate surface variables generally limit SO2 deposition below about 70% RH on limestone and below at least 95% RH on marble. Aerodynamic variables generally limit deposition at higher relative humidity or when the surface is wet.The dry deposition of gaseous air pollutants on stone and other materials is influenced by atmospheric processes and the chemical characteristics of the deposited gas species and of the specific receptor material. Previous studies have shown that relative humidity, surface moisture, and acid buffering capability of the receptor surface are very important factors. To better quantify this behavior, a special recirculating wind tunnel/environmental chamber was constructed, in which wind speed, turbulence, air temperature, relative humidity, and concentrations of several pollutants (SO2, O3

  12. SO2 over Central China: Measurements, Numerical Simulations and the Tropospheric Sulfur Budget

    NASA Technical Reports Server (NTRS)

    He, Hao; Li, Can; Loughner, Christopher P.; Li, Zhangqing; Krotkov, Nickolay A.; Yang, Kai; Wang, Lei; Zheng, Youfei; Bao, Xiangdong; Zhao, Guoqiang; Dickerson, Russell R.

    2012-01-01

    SO2 in central China was measured in situ from an aircraft and remotely using the Ozone Monitoring Instrument (OMI) from the Aura satellite; results were used to develop a numerical tool for evaluating the tropospheric sulfur budget - sources, sinks, transformation and transport. In April 2008, measured ambient SO2 concentrations decreased from approx.7 ppbv near the surface to approx. 1 ppbv at 1800 m altitude (an effective scale height of approx.800 m), but distinct SO2 plumes were observed between 1800 and 4500 m, the aircraft's ceiling. These free tropospheric plumes play a major role in the export of SO2 and in the accuracy of OMI retrievals. The mean SO2 column contents from aircraft measurements (0.73 DU, Dobson Units) and operational OMI SO2 products (0.63+/-0.26 DU) were close. The OMI retrievals were well correlated with in situ measurements (r = 0.84), but showed low bias (slope = 0.54). A new OMI retrieval algorithm was tested and showed improved agreement and bias (r = 0.87, slope = 0.86). The Community Multiscale Air Quality (CMAQ) model was used to simulate sulfur chemistry, exhibiting reasonable agreement (r = 0.62, slope = 1.33) with in situ SO2 columns. The mean CMAQ SO2 loading over central and eastern China was 54 kT, approx.30% more than the estimate from OMI SO2 products, 42 kT. These numerical simulations, constrained by observations, indicate that ",50% (35 to 61 %) of the anthropogenic sulfur emissions were transported downwind, and the overall lifetime of tropospheric SO2 was 38+/-7 h.

  13. Intercomparison of SO2 camera systems for imaging volcanic gas plumes

    NASA Astrophysics Data System (ADS)

    Kern, Christoph; Lübcke, Peter; Bobrowski, Nicole; Campion, Robin; Mori, Toshiya; Smekens, Jean-François; Stebel, Kerstin; Tamburello, Giancarlo; Burton, Mike; Platt, Ulrich; Prata, Fred

    2015-07-01

    SO2 camera systems are increasingly being used to image volcanic gas plumes. The ability to derive SO2 emission rates directly from the acquired imagery at high time resolution allows volcanic process studies that incorporate other high time-resolution datasets. Though the general principles behind the SO2 camera have remained the same for a number of years, recent advances in CCD technology and an improved understanding of the physics behind the measurements have driven a continuous evolution of the camera systems. Here we present an intercomparison of seven different SO2 cameras. In the first part of the experiment, the various technical designs are compared and the advantages and drawbacks of individual design options are considered. Though the ideal design was found to be dependent on the specific application, a number of general recommendations are made. Next, a time series of images recorded by all instruments at Stromboli Volcano (Italy) is compared. All instruments were easily able to capture SO2 clouds emitted from the summit vents. Quantitative comparison of the SO2 load in an individual cloud yielded an intra-instrument precision of about 12%. From the imagery, emission rates were then derived according to each group's standard retrieval process. A daily average SO2 emission rate of 61 ± 10 t/d was calculated. Due to differences in spatial integration methods and plume velocity determination, the time-dependent progression of SO2 emissions varied significantly among the individual systems. However, integration over distinct degassing events yielded comparable SO2 masses. Based on the intercomparison data, we find an approximate 1-sigma precision of 20% for the emission rates derived from the various SO2 cameras. Though it may still be improved in the future, this is currently within the typical accuracy of the measurement and is considered sufficient for most applications.

  14. Intercomparison of SO2 camera systems for imaging volcanic gas plumes

    USGS Publications Warehouse

    Kern, Christoph; Lübcke, Peter; Bobrowski, Nicole; Campion, Robin; Mori, Toshiya; Smekens, Jean-Francois; Stebel, Kerstin; Tamburello, Giancarlo; Burton, Mike; Platt, Ulrich; Prata, Fred

    2015-01-01

    SO2 camera systems are increasingly being used to image volcanic gas plumes. The ability to derive SO2 emission rates directly from the acquired imagery at high time resolution allows volcanic process studies that incorporate other high time-resolution datasets. Though the general principles behind the SO2 camera have remained the same for a number of years, recent advances in CCD technology and an improved understanding of the physics behind the measurements have driven a continuous evolution of the camera systems. Here we present an intercomparison of seven different SO2 cameras. In the first part of the experiment, the various technical designs are compared and the advantages and drawbacks of individual design options are considered. Though the ideal design was found to be dependent on the specific application, a number of general recommendations are made. Next, a time series of images recorded by all instruments at Stromboli Volcano (Italy) is compared. All instruments were easily able to capture SO2 clouds emitted from the summit vents. Quantitative comparison of the SO2 load in an individual cloud yielded an intra-instrument precision of about 12%. From the imagery, emission rates were then derived according to each group's standard retrieval process. A daily average SO2 emission rate of 61 ± 10 t/d was calculated. Due to differences in spatial integration methods and plume velocity determination, the time-dependent progression of SO2 emissions varied significantly among the individual systems. However, integration over distinct degassing events yielded comparable SO2 masses. Based on the intercomparison data, we find an approximate 1-sigma precision of 20% for the emission rates derived from the various SO2 cameras. Though it may still be improved in the future, this is currently within the typical accuracy of the measurement and is considered sufficient for most applications.

  15. Spatiotemporal variations of tropospheric SO2 over China by SCIAMACHY observations during 2004-2009

    NASA Astrophysics Data System (ADS)

    Zhang, Xingying; van Geffen, Jos; Liao, Hong; Zhang, Peng; Lou, Sijia

    2012-12-01

    This paper presents results of measurements of tropospheric sulphur dioxide (SO2) from satellite over China during 2004-2009. SCIAMACHY/ENVISAT SO2 data products have been validated by ground based remote sensing instrument MAXDOAS in China, and with predictions of the atmospheric model GEOS-Chem. The spatial and temporal distribution of tropospheric SO2 over China is discussed in this study. The result shows that the SO2 load over East China is decreasing since strong control for pollution emission in 2007 for preparation of 2008 Olympic Games in China, while the SO2 load in West China is increasing all the way during 2004-2009, which might reflect that the anthropogenic activity was added to promote the economy development in west of China. Typical seasonal variation with high pollution levels in winter and low in summer is found in the northwest of China, while the inverse seasonal variation is found for the south of China. The characteristics of tropospheric SO2 over the major cities in China were explored and found that tropospheric SO2 was partly under control from 2007 because of the policy from China government for reduction in SO2 emissions in 2006. And the SO2 value shows remarkably decrease in most of the major cities after 2007 because strong control for the pollution emission for 2008 Olympic games. Guangzhou city shows high SO2 pollution levels in summer time, since most of the coal power plants and thermal power industry are located to the south of Guangzhou city and southerly winds dominate during summer time.

  16. Acidity of vapor plume from cooling tower mixed with flue gases emitted from coal-fired power plant.

    PubMed

    Hlawiczka, Stanislaw; Korszun, Katarzyna; Fudala, Janina

    2016-06-01

    Acidity of products resulting from the reaction of flue gas components emitted from a coal-fired power plant with water contained in a vapor plume from a wet cooling tower was analyzed in a close vicinity of a power plant (710 m from the stack and 315 m from the cooling tower). Samples of this mixture were collected using a precipitation funnel where components of the mixed plumes were discharged from the atmosphere with the rainfall. To identify situations when the precipitation occurred at the same time as the wind directed the mixed vapor and flue gas plumes above the precipitation funnel, an ultrasound anemometer designed for 3D measurements of the wind field located near the funnel was used. Precipitation samples of extremely high acidity were identified - about 5% of samples collected during 12 months showed the acidity below pH=3 and the lowest recorded pH was 1.4. During the measurement period the value of pH characterizing the background acidity of the precipitation was about 6. The main outcome of this study was to demonstrate a very high, and so far completely underestimated, potential of occurrence of episodes of extremely acid depositions in the immediate vicinity of a coal-fired power plant. PMID:26950639

  17. Sulfuric acid vapor and other cloud-related gases in the Venus atmosphere - Abundances inferred from observed radio opacity

    NASA Technical Reports Server (NTRS)

    Steffes, P. G.; Eshleman, V. R.

    1982-01-01

    It is suggested that the absorbing characteristics of sulfuric acid vapor appear to reconcile what had been thought to be an inconsistency among measurements and deductions regarding the constituents of the Venus atmosphere and radio occultation, radar reflection, and radio emission measurements of its opacity. Laboratory measurements of sulfuric acid, sulfur dioxide, water vapor, and carbon dioxide are used to model relative contributions to opacity as a function of height in a way that is consistent with observations of the constituents and absorbing properties of the atmosphere. It is concluded that sulfuric acid vapor is likely to be the principal microwave absorber in the 30-50 km altitude range of the middle atmosphere of Venus.

  18. Regional differences in Chinese SO2 emission control efficiency and policy implications

    NASA Astrophysics Data System (ADS)

    Zhang, Q. Q.; Wang, Y.; Ma, Q.; Xie, Y.; He, K.

    2015-02-01

    SO2 emission control has been one of the most important air pollution policies in China since 2000. In this study, we assess regional differences in SO2 emission control efficiencies in China through the modeling analysis of four scenarios of SO2 emissions, all of which aim at reducing the national total SO2 emissions by 8% or 2.3 Tg below the 2010 emissions level, the target set by the current 12th FYP (2011-2015), but differ in the spatial implementation. The GEOS-Chem chemical transport model is used to evaluate the efficiency of each scenario on the basis of three impact metrics: surface sulfate concentration, population-weighted sulfate concentration (PWC), and sulfur export flux from China to the Western Pacific. The efficiency of SO2 control (β) is defined as the relative change of each impact metric to a 1% reduction of SO2 emissions from the 2010 baseline. The S1 scenario, which adopts a spatially uniform reduction of SO2 emissions in China, gives a β of 0.71, 0.83, and 0.67 for sulfate concentration, PWC, and export flux, respectively. By comparison, the S2 scenario, which implements all the SO2 emissions reduction over North China (NC), is found most effective in reducing national-mean surface sulfate concentrations and sulfur export fluxes, with β being 0.76 and 0.95 respectively. The S3 scenario of implementing all the SO2 emission reduction over South China (SC) has the highest β in reducing PWC (β = 0.98) because SC has the highest correlation between population density and sulfate concentration. Reducing SO2 emissions over Southwest China (SWC) is found to be least efficient on the national scale, albeit within-region benefit. The difference in β by scenario is attributable to regional differences in SO2 oxidation pathways and source-receptor relationships. Among the three regions examined here, NC shows the largest proportion of sulfate formation from gas phase oxidation, which is more sensitive to SO2 emission change than aqueous oxidation

  19. The vertical distribution of volcanic SO2 plumes measured by IASI

    NASA Astrophysics Data System (ADS)

    Carboni, Elisa; Grainger, Roy; Mather, Tamsin A.; Pyle, David M.; Thomas, Gareth; Siddans, Richard; Smith, Andrew; Dudhia, Anu; Koukouli, MariLiza; Balis, Dimitris

    2015-04-01

    Sulphur dioxide (SO2) is an important atmospheric constituent that plays a crucial role in many atmospheric processes. For example the current hiatus in global warming has been suggested to be caused by low level (< 15 km) volcanic activity (Ridley et al., 2014). Volcanic eruptions are a significant source of atmospheric SO2 and its effects and lifetime depend on the SO2 injection altitude. In the troposphere SO2 injection leads to the acidification of rainfall while in the stratosphere it oxidises to form a stratospheric H2SO4 haze that can affect climate for several years. The Infrared Atmospheric Sounding Instrument (IASI) on the Metop satellite can be used to study volcanic emission of SO2 using high-spectral resolution measurements from 1000 to 1200 cm-1 and from 1300 to 1410 cm-1 (the 7.3 and 8.7 μm SO2 bands). The scheme described in Carboni et al. (2012) has been applied to measure volcanic SO2 amount and altitude for 14 explosive eruptions from 2008 to 2012. The work includes a comparison with independent measurements: (i) the SO2 column amounts from the 2010 Eyjafjallajökull plumes have been compared with Brewer ground measurements over Europe; (ii) the SO2 plumes heights have been compared with CALIPSO backscatter profile. The results of the comparisons show that IASI SO2 measurements are not affected by underling cloud and are consistent (within the retrieved errors) with the other measurements considered. The series of analysed eruptions (2008 to 2012) show that the biggest contributor of volcanic SO2 was Nabro, followed by Kasatochi and Grímsvötn. Our observations also show a tendency of the volcanic SO2 to be injected to the level of tropopause during many explosive eruptions. For the eruptions observed, this tendency was independent of the maximum amount of SO2 erupted (e.g., 0.2 Tg for Dalafilla compared with 1.6 Tg for Nabro) and of the volcanic explosive index (between 3 and 5).

  20. Measurements of HNO3, SO2 High Resolution Aerosol SO4 (sup 2-), and Selected Aerosol Species Aboard the NASA DC-8 Aircraft: During the Transport and Chemical Evolution Over the Pacific Airborne Mission (TRACE-P)

    NASA Technical Reports Server (NTRS)

    Talbot, Robert W.; Dibb, Jack E.

    2004-01-01

    The UNH investigation during TRACE-P provided measurements of selected acidic gases and aerosol species aboard the NASA DC-8 research aircraft. Our investigation focused on measuring HNO3, SO2, and fine (less than 2 microns) aerosol SO4(sup 2-) with two minute time resolution in near-real-time. We also quantified mixing ratios of aerosol ionic species, and aerosol (210)Pb and (7)Be collected onto bulk filters at better than 10 minute resolution. This suite of measurements contributed extensively to achieving the principal objectives of TRACE-P. In the context of the full data set collected by experimental teams on the DC-8, our observations provide a solid basis for assessing decadal changes in the chemical composition and source strength of Asian continental outflow. This region of the Pacific should be impacted profoundly by Asian emissions at this time with significant degradation of air quality over the next few decades. Atmospheric measurements in the western Pacific region will provide a valuable time series to help quantify the impact of Asian anthropogenic activities. Our data also provide important insight into the chemical and physical processes transforming Asian outflow during transport over the Pacific, particularly uptake and reactions of soluble gases on aerosol particles. In addition, the TRACE-P data set provide strong constraints for assessing and improving the chemical fields simulated by chemical transport models.

  1. 40 CFR 97.721 - Recordation of TR SO2 Group 2 allowance allocations and auction results.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Recordation of TR SO2 Group 2... SO2 TRADING PROGRAMS TR SO2 Group 2 Trading Program § 97.721 Recordation of TR SO2 Group 2 allowance allocations and auction results. (a) By November 7, 2011, the Administrator will record in each TR SO2 Group...

  2. 40 CFR 97.621 - Recordation of TR SO2 Group 1 allowance allocations and auction results.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Recordation of TR SO2 Group 1... SO2 TRADING PROGRAMS TR SO2 Group 1 Trading Program § 97.621 Recordation of TR SO2 Group 1 allowance allocations and auction results. (a) By November 7, 2011, the Administrator will record in each TR SO2 Group...

  3. 40 CFR 97.721 - Recordation of TR SO2 Group 2 allowance allocations and auction results.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Recordation of TR SO2 Group 2... SO2 TRADING PROGRAMS TR SO2 Group 2 Trading Program § 97.721 Recordation of TR SO2 Group 2 allowance allocations and auction results. (a) By November 7, 2011, the Administrator will record in each TR SO2 Group...

  4. 40 CFR 97.621 - Recordation of TR SO2 Group 1 allowance allocations and auction results.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Recordation of TR SO2 Group 1... SO2 TRADING PROGRAMS TR SO2 Group 1 Trading Program § 97.621 Recordation of TR SO2 Group 1 allowance allocations and auction results. (a) By November 7, 2011, the Administrator will record in each TR SO2 Group...

  5. 40 CFR 97.621 - Recordation of TR SO2 Group 1 allowance allocations and auction results.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Recordation of TR SO2 Group 1... SO2 TRADING PROGRAMS TR SO2 Group 1 Trading Program § 97.621 Recordation of TR SO2 Group 1 allowance allocations and auction results. (a) By November 7, 2011, the Administrator will record in each TR SO2 Group...

  6. 40 CFR 97.721 - Recordation of TR SO2 Group 2 allowance allocations and auction results.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Recordation of TR SO2 Group 2... SO2 TRADING PROGRAMS TR SO2 Group 2 Trading Program § 97.721 Recordation of TR SO2 Group 2 allowance allocations and auction results. (a) By November 7, 2011, the Administrator will record in each TR SO2 Group...

  7. Toxic gases.

    PubMed Central

    Matthews, G.

    1989-01-01

    An overview of the widespread use of gases and some volatile solvents in modern society is given. The usual circumstances in which undue exposure may occur are described. The most prominent symptoms and general principles of diagnosis and treatment are given and are followed by more specific information on the commoner, more toxic materials. While acute poisonings constitute the greater part of the paper, some indication of chronic disorders arising from repeated or prolonged exposure is also given. PMID:2687827

  8. Noble Gases

    NASA Astrophysics Data System (ADS)

    Podosek, F. A.

    2003-12-01

    The noble gases are the group of elements - helium, neon, argon, krypton, xenon - in the rightmost column of the periodic table of the elements, those which have "filled" outermost shells of electrons (two for helium, eight for the others). This configuration of electrons results in a neutral atom that has relatively low electron affinity and relatively high ionization energy. In consequence, in most natural circumstances these elements do not form chemical compounds, whence they are called "noble." Similarly, much more so than other elements in most circumstances, they partition strongly into a gas phase (as monatomic gas), so that they are called the "noble gases" (also, "inert gases"). (It should be noted, of course, that there is a sixth noble gas, radon, but all isotopes of radon are radioactive, with maximum half-life a few days, so that radon occurs in nature only because of recent production in the U-Th decay chains. The factors that govern the distribution of radon isotopes are thus quite different from those for the five gases cited. There are interesting stories about radon, but they are very different from those about the first five noble gases, and are thus outside the scope of this chapter.)In the nuclear fires in which the elements are forged, the creation and destruction of a given nuclear species depends on its nuclear properties, not on whether it will have a filled outermost shell when things cool off and nuclei begin to gather electrons. The numerology of nuclear physics is different from that of chemistry, so that in the cosmos at large there is nothing systematically special about the abundances of the noble gases as compared to other elements. We live in a very nonrepresentative part of the cosmos, however. As is discussed elsewhere in this volume, the outstanding generalization about the geo-/cosmochemistry of the terrestrial planets is that at some point thermodynamic conditions dictated phase separation of solids from gases, and that the

  9. Studies of proton-irradiated SO2 at low temperatures Implications for Io

    NASA Astrophysics Data System (ADS)

    Moore, M. H.

    1984-07-01

    The infrared absorption spectrum from 3.3 to 27 microns of SO2 ice films has been measured at 20 and 88 K before and after 1-MeV proton irradiation. The radiation flux was chosen to simulate the estimated flux of Jovian magnetospheric 1-MeV protons incident on Io. After irradiation, SO3 is identified as the dominant molecule synthesized in the SO2 ice. This is also the case after irradiation of composite samples of SO2 with sulfur or disulfites. Darkening was observed in irradiated SO2 ice and in irradiated S8 pellets. Photometric and spectral measurements of the thermoluminescence of irradiated SO2 have been made during warming. The spectrum appears as a broad band with a maximum at 4450 A. Analysis of the luminescence data suggests that at Ionian temperatures irradiated SO2 ice would not be a dominant contributor to posteclipse brightening phenomena. After warming to room temperature, a form of SO3 remains along with a sulfate and S8. Based on these experiments, it is reasonable to propose that small amounts of SO3 may exist on the surface of Io as a result of irradiation synthesis in SO2 frosts.

  10. Studies of proton-irradiated SO2 at low temperatures Implications for Io

    NASA Technical Reports Server (NTRS)

    Moore, M. H.

    1984-01-01

    The infrared absorption spectrum from 3.3 to 27 microns of SO2 ice films has been measured at 20 and 88 K before and after 1-MeV proton irradiation. The radiation flux was chosen to simulate the estimated flux of Jovian magnetospheric 1-MeV protons incident on Io. After irradiation, SO3 is identified as the dominant molecule synthesized in the SO2 ice. This is also the case after irradiation of composite samples of SO2 with sulfur or disulfites. Darkening was observed in irradiated SO2 ice and in irradiated S8 pellets. Photometric and spectral measurements of the thermoluminescence of irradiated SO2 have been made during warming. The spectrum appears as a broad band with a maximum at 4450 A. Analysis of the luminescence data suggests that at Ionian temperatures irradiated SO2 ice would not be a dominant contributor to posteclipse brightening phenomena. After warming to room temperature, a form of SO3 remains along with a sulfate and S8. Based on these experiments, it is reasonable to propose that small amounts of SO3 may exist on the surface of Io as a result of irradiation synthesis in SO2 frosts.

  11. Comparison of COSPEC and two miniature ultraviolet spectrometer systems for SO2 measurements using scattered sunlight

    USGS Publications Warehouse

    Elias, Tamar; Sutton, A. Jeff; Oppenheimer, Clive; Horton, Keith A.; Garbeil, Harold; Tsanev, Vitchko; McGonigle, Andrew J.S.; Williams-Jones, Glyn

    2006-01-01

    The correlation spectrometer (COSPEC), the principal tool for remote measurements of volcanic SO2, is rapidly being replaced by low-cost, miniature, ultraviolet (UV) spectrometers. We compared two of these new systems with a COSPEC by measuring SO2 column amounts at Kīlauea Volcano, Hawaii. The two systems, one calibrated using in-situ SO2 cells, and the other using a calibrated laboratory reference spectrum, employ similar spectrometer hardware, but different foreoptics and spectral retrieval algorithms. Accuracy, signal-to-noise, retrieval parameters, and precision were investigated for the two configurations of new miniature spectrometer. Measurements included traverses beneath the plumes from the summit and east rift zone of Kīlauea, and testing with calibration cells of known SO2 concentration. The results obtained from the different methods were consistent with each other, with <8% difference in estimated SO2 column amounts up to 800 ppm m. A further comparison between the COSPEC and one of the miniature spectrometer configurations, the ‘FLYSPEC’, spans an eight month period and showed agreement of measured emission rates to within 10% for SO2 column amounts up to 1,600 ppm m. The topic of measuring high SO2 burdens accurately is addressed for the Kīlauea measurements. In comparing the foreoptics, retrieval methods, and resultant implications for data quality, we aim to consolidate the various experiences to date, and improve the application and development of miniature spectrometer systems.`

  12. Simultaneous adsorption of SO2 and NO from flue gas over mesoporous alumina.

    PubMed

    Sun, Xin; Tang, Xiaolong; Yi, Honghong; Li, Kai; Ning, Ping; Huang, Bin; Wang, Fang; Yuan, Qin

    2015-01-01

    Mesoporous alumina (MA) with a higher ability to simultaneously remove SO2 and NO was prepared by the evaporation-induced self-assembly process. The adsorption capacities of MA are 1.79 and 0.702 mmol/g for SO2 and NO, respectively. The Brunauer-Emmett-Teller method was used to characterize the adsorbent. Simultaneous adsorption of SO2 and NO from flue gas over MA in different operating conditions had been studied in a fixed bed reactor. The effects of temperature, oxygen concentration and water vapour were investigated. The experimental results showed that the optimum temperature for MA to simultaneously remove SO2 and NO was 90°C. The simultaneous adsorption capacities of SO2 and NO could be enhanced by increasing O2 when its concentration was below 5%. The changes of simultaneous adsorption capacities were not obvious when O2 concentration was above 5%. The increase in relative humidity results in an increase after dropping of SO2 adsorption capacity, whereas the adsorption capacity of NO showed an opposite trend. The results suggest that MA is a great adsorbent for simultaneous removal of SO2 and NO from flue gas. PMID:25189414

  13. Measurements of dimethyl sulfide and SO2 during GTE/CITE 3

    NASA Technical Reports Server (NTRS)

    Ferek, Ronald J.; Hegg, Dean A.

    1993-01-01

    As part of NASA's Tropospheric Experiment Chemical Instrumentation Test and Evaluation (GTE/CITE 3) Sulfur Gas Intercomparison, we conducted measurements of dimethyl sulfide (DMS) and SO2 using two techniques well suited for sampling from an aircraft due to their simplicity of design. DMS was collected by preconcentration on gold wire preceded by a KOH-impregnated filter oxidant scrubber, and analyzed by gas chromatography with flame photometric detection. SO2 was collected on K2CO3/glycerol-impregnated filters and analyzed by ion chromatography. In blind tests, both techniques produced excellent agreement with National Institutes of Standards and Technology (NIST) standards. For field measurements, the DMS technique produced excellent correlation with the mean of the six different techniques intercompared. For SO2, the five techniques intercompared were rather poorly correlated, but correlations between the three techniques which passed NIST standards tests were somewhat better. Our SO2 filter measurements exhibited rather large uncertainties due to higher than normal variabiltiy of the filter blanks, which we believe was caused by extended storage in the field. In measurements conducted off the coast of Natal, Brazil, a diurnal afternoon minimum in DMS concentrations accompanied by a corresponding maximum in SO2 concentrations was observed. However, due to rather large uncertainties in the SO2 measurements, any conclusions about the SO2 trend must by considered tentative.

  14. Sulfur dioxide (SO2) vertical column density measurements by Pandora spectrometer over the Canadian oil sands

    NASA Astrophysics Data System (ADS)

    Fioletov, Vitali E.; McLinden, Chris A.; Cede, Alexander; Davies, Jonathan; Mihele, Cristian; Netcheva, Stoyka; Li, Shao-Meng; O'Brien, Jason

    2016-07-01

    Vertical column densities (VCDs) of SO2 retrieved by a Pandora spectral sun photometer at Fort McKay, Alberta, Canada, from 2013 to 2015 were analysed. The Fort McKay site is located in the Canadian oil sands region, approximately 20 km north of two major SO2 sources (upgraders), with total emission of about 45 kt yr-1. Elevated SO2 VCD values were frequently recorded by the instrument, with the highest values of about 9 Dobson Units (DU; DU = 2.69 × 1016 molecules cm-2). Comparisons with co-located in situ measurements demonstrated that there was a very good correlation between VCDs and surface concentrations in some cases, while in other cases, elevated VCDs did not correspond to high surface concentrations, suggesting the plume was above the ground. Elevated VCDs and surface concentrations were observed when the wind direction was from south to southeast, i.e. from the direction of the two local SO2 sources. The precision of the SO2 measurements, estimated from parallel measurements by two Pandora instruments at Toronto, is 0.17 DU. The total uncertainty of Pandora SO2 VCD, estimated using measurements when the wind direction was away from the sources, is less than 0.26 DU (1σ). Comparisons with integrated SO2 profiles from concurrent aircraft measurements support these estimates.

  15. Measuring volcanic degassing of SO 2 in the lower troposphere with ASTER band ratios

    NASA Astrophysics Data System (ADS)

    Campion, Robin; Salerno, Giuseppe Giovanni; Coheur, Pierre-François; Hurtmans, Daniel; Clarisse, Lieven; Kazahaya, Kohei; Burton, Michael; Caltabiano, Tommaso; Clerbaux, Cathy; Bernard, Alain

    2010-07-01

    We present a new method for measuring SO 2 with the data from the ASTER (Advanced Spaceborne Thermal Emission and Reflectance radiometer) orbital sensor. The method consists of adjusting the SO 2 column amount until the ratios of radiance simulated on several ASTER bands match the observations. We present a sensitivity analysis for this method, and two case studies. The sensitivity analysis shows that the selected band ratios depend much less on atmospheric humidity, sulfate aerosols, surface altitude and emissivity than the raw radiances. Measurements with < 25% relative precision are achieved, but only when the thermal contrast between the plume and the underlying surface is higher than 10 K. For the case studies we focused on Miyakejima and Etna, two volcanoes where SO 2 is measured regularly by COSPEC or scanning DOAS. The SO 2 fluxes computed from a series of ten images of Miyakejima over the period 2000-2002 is in agreement with the long term trend of measurement for this volcano. On Etna, we compared SO 2 column amounts measured by ASTER with those acquired simultaneously by ground-based automated scanning DOAS. The column amounts compare quite well, providing a more rigorous validation of the method. The SO 2 maps retrieved with ASTER can provide quantitative insights into the 2D structure of non-eruptive volcanic plumes, their dispersion and their progressive depletion in SO 2.

  16. Lessons Learned from OMI Observations of Point Source SO2 Pollution

    NASA Technical Reports Server (NTRS)

    Krotkov, N.; Fioletov, V.; McLinden, Chris

    2011-01-01

    The Ozone Monitoring Instrument (OMI) on NASA Aura satellite makes global daily measurements of the total column of sulfur dioxide (SO2), a short-lived trace gas produced by fossil fuel combustion, smelting, and volcanoes. Although anthropogenic SO2 signals may not be detectable in a single OMI pixel, it is possible to see the source and determine its exact location by averaging a large number of individual measurements. We describe new techniques for spatial and temporal averaging that have been applied to the OMI SO2 data to determine the spatial distributions or "fingerprints" of SO2 burdens from top 100 pollution sources in North America. The technique requires averaging of several years of OMI daily measurements to observe SO2 pollution from typical anthropogenic sources. We found that the largest point sources of SO2 in the U.S. produce elevated SO2 values over a relatively small area - within 20-30 km radius. Therefore, one needs higher than OMI spatial resolution to monitor typical SO2 sources. TROPOMI instrument on the ESA Sentinel 5 precursor mission will have improved ground resolution (approximately 7 km at nadir), but is limited to once a day measurement. A pointable geostationary UVB spectrometer with variable spatial resolution and flexible sampling frequency could potentially achieve the goal of daily monitoring of SO2 point sources and resolve downwind plumes. This concept of taking the measurements at high frequency to enhance weak signals needs to be demonstrated with a GEOCAPE precursor mission before 2020, which will help formulating GEOCAPE measurement requirements.

  17. Mapping the BrO/SO2 ratio in the plume of Popocatépetl, Mexico with Imaging-DOAS

    NASA Astrophysics Data System (ADS)

    Zielcke, Johannes; Luebcke, Peter; Vogel, Leif; Bobrowski, Nicole; Platt, Ulrich

    2015-04-01

    Differential Optical Absorption Spectroscopy (DOAS) in the ultraviolet and visible wavelength region has become a widespread tool, not only to study the chemistry of trace gases such as sulphur dioxide (SO2) and halogen oxides (e.g. BrO, OClO) in volcanic plumes. It can also be used for volcano monitoring by observing SO2 fluxes and the molar ratio of BrO to SO2, which is a possible precursor for dynamic changes in the shallow part of a volcanic system like other halogen/sulfur ratios. This acquisition of this ratio is convenient as it can be measured with comparatively simple UV DOAS instruments. Imaging-DOAS (IDOAS) utilizes the push-broom or whisk-broom technique to create a hyperspectral image of a section of the sky, then the DOAS evaluation is applied to each pixel to derive trace gas slant column densities (SCDs). Hereby images of the SO2 and BrO distribution can be created, allowing to study the chemistry in different parts of the plume. This is especially interesting for the case of BrO, which is produced in the atmosphere and not directly emitted by volcanoes. Here we present IDOAS measurements carried out at Popocatépetl volcano, Mexico, during April 2010 and 2011. SO2 SCDs of up to 2 - 1018 molecules cm-2 and BrO SCDs of up to 7 - 1013 molecules cm-2 were detected. The determined BrO/SO2 ratios range around 3 - 10-5, comparable to several other volcanoes in the Americas. An increase in the determined BrO/SO2 ratios with distance from the vent, i.e. plume age, can be observed.

  18. The global distribution, abundance, and stability of SO2 on Io

    USGS Publications Warehouse

    McEwen, A.S.; Johnson, T.V.; Matson, D.L.; Soderblom, L.A.

    1988-01-01

    Sulfur dioxide distribution and abundances, bolometric hemispheric albedos, and passive surface temperatures on Io are modeled and mapped globally from Voyager multispectral mosaics, Earth-based spectra, and photometric descriptions. Photometric models indicate global average values for regolith porosity of 75-95% and macroscopic roughness with a mean slope angle of ~30??. Abundances of SO2 suggested by observations at uv-visible wavelengths and at 4.08 ??m are partially reconciled by intimate-mixing models; 30-50% SO2 coverage of the integral disk is indicated. Three major spectral end members, with continuous mixing, are recognized from the Voyager multispectral mosaics; one of these end members is identified as SO2. Intimate-mixing models with the three spectal end members are used to produce abundance maps for the optical surface; ~30% of Io's total optical surface consists of SO2. The SO2 is concentrated in the bright equatorial band and is relatively deficient in the region of Pele-type volcanic reuptions (long 240??-360??) and the polar regions. Temperatures are computed to vary over a 40??K range, at the same illumination angle, according to variations in surface bolometric hemispheric albedo. The brightest (and locally coldest) areas correspond to areas rich in SO2 and are concentrated in an equatorial band (??30?? lat), but many small cold patches occur elsewhere. These cold patches have radiative equilibrium temperatures ???120??K at the subsolar point, resulting in SO2 saturation vapor pressures ???10-8 bar. Midlatitude areas and the region of Pele-type plume eruptions are generally warmer (due to lower albedos). These results for surface temperatures and SO2 abundances and distribution support the regional coldtrapping model for the surface and atmospheric SO2 presented by F.P. Fanale, W.B. Banerdt, L.S. Elson, T.V. Johnson, and R.W. Zurek (1982, In Satellites of Jupiter (D. Morrison, Ed.), pp. 756-781, Univ. of Arizona Press, Tucson), although the

  19. Calculation of pressure-broadened linewidths of SO2 and NO2.

    NASA Technical Reports Server (NTRS)

    Tejwani, G. D. T.

    1972-01-01

    The Anderson-Tsao-Curnutte theory of line broadening (1949, 1962) is applied to calculate the self-broadened and N2- and O2-broadened linewidths of SO2 and NO2. Computed linewidth values are in good agreement with available experimental results and with calculations by Murphy and Boggs (1967, 1969) on four self-broadened and one nitrogen-broadened lines. Air-broadened linewidths are also calculated for SO2 at 200, 250 and 300 K. The results are considered to be useful for predicting theoretical spectra of SO2 under atmospheric conditions.

  20. Measurement of SO2 and SO3 using a tunable diode laser system

    NASA Astrophysics Data System (ADS)

    Berkoff, Timothy A.; Wormhoudt, Joda C.; Miake-Lye, R. C.

    1999-02-01

    We describe the set-up and operation of a mid-infrared (lead- salt) tunable diode laser system used to measure SO2 and SO3 levels in the exhaust plume of an aircraft engine in an altitude test chamber. These measurements were part of an on-going effort to determine the sulfur emission and conversion of SO2 to SO3 in a representative exhaust under different altitudes, power conditions, and fuel sulfur loadings. Results obtained using this set-up demonstrate the ability to measure SO2 concentrations in the low ppmv range and the possibility of detecting SO3 when it is present at similar levels.