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Sample records for gases so2 no2

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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.

  15. 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...

  16. 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.

  17. 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

  18. 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

  19. Satellite observations of SO2, NO2, CO, and aerosol over China

    NASA Astrophysics Data System (ADS)

    Massie, S.; Wu, F.; Krotkov, N.; Levelt, P.; Chu, A.

    2009-04-01

    Satellite observations of SO2, NO2, CO, and aerosol over China are related to demographic population density, emissions inventories, industrial production, and thermal power plant geospatial distributions. Similarities and differences in the geospatial distributions of SO2, NO2, CO, and aerosol are identified. Ozone Monitoring Instrument (OMI) SO2 and NO2 atmospheric columns, Measurements of Pollution in the Troposphere (MOPITT) CO columns, and Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depths over China are analyzed during 2005-2007. A comparison of OMI NO2 and University of Columbia gridded population maps indicates a close correspondence between centers of enhanced NO2 and population, with enhanced NO2 and SO2 co-located along the geospatial arc from Shijiazhuang to Luoyang in Hebei, Shanxi, and Henan provinces of China. The region near 35 N and 112 E in northern Henan and southern Shanxi provinces has maxima in NO2, SO2, and CO, which is co-located with power plant number density and population centers. Trends in Global Ozone Monitoring Experiment (GOME) and Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) NO2 over China from 1996 - 2007, and OMI NO2 from 2004-2008, are compared, and placed in context, to other regions of the world. In accord with previous studies, trends in GOME and SCIAMACHY NO2 over China during 1996-2007 are positive, while trends over Europe and the United States are negative. OMI NO2 columns increase by 8.7 % per year over eastern China (20-30 N, 110-123 E) in the winters of 2004-2008.

  20. 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.

  1. Satellite and ground based seasonal variability of NO2 and SO2 over New Delhi, India

    NASA Astrophysics Data System (ADS)

    Pandey, Alok K.; Kumar, Ram P.; Kumar, Krishan

    2015-10-01

    Remote sensing technology application emerges as a useful tool for exploring atmospheric pollution revelation in the last two decade. In this study, we used Aura satellite Ozone Monitoring Instrument (OMI) tropospheric NO2 and pbl SO2 retrieval data (October 2004 - September 2013) to generate a composite spatial map of different seasons over New Delhi National Capital Region (NCR). For surface measurements, we used Central Pollution Control Board (CPCB) NO2 and SO2 data (January 2005 - December 2013). Further, we compared the satellite retrievals data to the surface measurements. A higher NO2 concentration in both OMI and CPCB stations measurements are obtained in winter season followed by summer and minimum in monsoon months. OMI SO2 concentration is higher in monsoon months and almost comparable in summer and winter seasons. We obtained a statistically significant correlation between OMI tropospheric NO2 and CPCB surface measurements.

  2. 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.

  3. 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.

  4. UV Fourier transform measurements of tropospheric O3, NO2, SO2, benzene, and toluene.

    PubMed

    Vandaele, A C; Tsouli, A; Carleer, M; Colin, R

    2002-01-01

    Using the differential optical absorption spectroscopy (DOAS) technique and a Fourier transform spectrometer, NO2, SO2, O3, benzene. and toluene were measured during three measurement campaigns held in Brussels in 1995, 1996, and 1997. The O3 concentrations could be explained as the results of the local photochemistry and the dynamical properties of the mixing layer. NO2 concentrations were anti-correlated to the O3 concentrations, as expected. SO2 also showed a pronounced dependence on car traffic. Average benzene and toluene concentrations were, respectively 1.7 ppb and between 4.4 and 6.6 pbb, but high values of toluene up to 98.8 ppb were observed. SO2 concentrations and to a lesser extent, those of NO2 and 03, were dependent on the wind direction. Ozone in Brussels has been found to be influenced by the meteorological conditions prevailing in central Europe. Comparisons with other measurements have shown that 03 and SO2 data are in general in good agreement, but our NO2 concentrations seem to be generally higher. PMID:11806447

  5. GROWTH RESPONSE IN RADISH TO SEQUENTIAL AND SIMULTANEOUS EXPOSURES OF NO2 AND SO2

    EPA Science Inventory

    Sequential and simultaneous exposures of radish Raphanus sativus L. cv. Cherry Belle to 0.8 microliters per liter nitrogen dioxide (NO2) and 0.8 microliters per liter sulphur dioxide (SO2) were conducted under both day- and night-time conditions to examine the effects on growth a...

  6. 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).

  7. 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).

  8. 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.

  9. 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.

  10. Health risks of NO 2, SPM and SO 2 in Delhi (India)

    NASA Astrophysics Data System (ADS)

    Pandey, Jai Shanker; Kumar, Rakesh; Devotta, Sukumar

    There is increasingly growing evidence linking urban air pollution to acute and chronic illnesses amongst all age groups. Therefore, monitoring of ambient concentrations of various air pollutants as well as quantification of the dose inhaled becomes quite important, specially in view of the fact that in many countries, policy decisions for reducing pollutant concentrations are mainly taken on the basis of their health impacts. The dose when gets combined with the likely responses, indicates the ultimate health risk (HR). Thus, as an extension of our earlier studies, HR has been estimated for three pollutants, namely, suspended particulate matter (SPM), nitrogen dioxide (NO 2) and sulfur dioxide (SO 2) for Delhi City in India. For estimation and analyses, three zones have been considered, namely, residential, industrial and commercial. The total population has been divided into three age classes (infants, children and adults) with different body weights and breathing rates. The exercise takes into account age-specific breathing rates, body weights for different age categories and occupancy factors for different zones. Results indicate that health risks due to air pollution in Delhi are highest for children. For all age categories, health risks due to SO 2 (HR_SO 2) are the lowest. Hence, HR_SO 2 has been taken as the reference with respect to which HR values due to SPM and NO 2 have been compared. Taking into account all the age categories and their occupancy in different zones, average HR values for NO 2 and SPM turn out to be respectively 22.11 and 16.13 times more than that for SO 2. The present study can be useful in generating public awareness as well as in averting and mitigating the health risks.

  11. Ship emissions of SO2 and NO2: DOAS measurements from airborne platforms

    NASA Astrophysics Data System (ADS)

    Berg, N.; Mellqvist, J.; Jalkanen, J.-P.; Balzani, J.

    2012-05-01

    A unique methodology to measure gas fluxes of SO2 and NO2 from ships using optical remote sensing is described and demonstrated in a feasibility study. The measurement system is based on Differential Optical Absorption Spectroscopy using reflected skylight from the water surface as light source. A grating spectrometer records spectra around 311 nm and 440 nm, respectively, with the telescope pointed downward at a 30° angle from the horizon. The mass column values of SO2 and NO2 are retrieved from each spectrum and integrated across the plume. A simple geometric approximation is used to calculate the optical path. To obtain the total emission in kg h-1 the resulting total mass across the plume is multiplied with the apparent wind, i.e. a dilution factor corresponding to the vector between the wind and the ship speed. The system was tested in two feasibility studies in the Baltic Sea and Kattegat, from a CASA-212 airplane in 2008 and in the North Sea outside Rotterdam from a Dauphin helicopter in an EU campaign in 2009. In the Baltic Sea the average SO2 emission out of 22 ships was (54 ± 13) kg h-1, and the average NO2 emission was (33 ± 8) kg h-1, out of 13 ships. In the North Sea the average SO2 emission out of 21 ships was (42 ± 11) kg h-1, NO2 was not measured here. The detection limit of the system made it possible to detect SO2 in the ship plumes in 60% of the measurements when the described method was used. A comparison exercise was carried out by conducting airborne optical measurements on a passenger ferry in parallel with onboard measurements. The comparison shows agreement of (-30 ± 14)% and (-41 ± 11)%, respectively, for two days, with equal measurement precision of about 20%. This gives an idea of the measurement uncertainty caused by errors in the simple geometric approximation for the optical light path neglecting scattering of the light in ocean waves and direct and multiple scattering in the exhaust plume under various conditions. A tentative

  12. Ship emissions of SO2 and NO2: DOAS measurements from airborne platforms

    NASA Astrophysics Data System (ADS)

    Berg, N.; Mellqvist, J.; Jalkanen, J.-P.; Balzani, J.

    2011-10-01

    A unique methodology to measure gas fluxes of SO2 and NO2 from ships has been developed in a Swedish national project using optical remote sensing. The measurement system is based on Differential Optical Absorption Spectroscopy using reflected skylight from the water surface as light source. A grating spectrometer records spectra around 311 nm and 440 nm, respectively, with the telescope pointed downward at a 30° angle from the horizon. The mass column values of SO2 and NO2 are retrieved from each spectrum and integrated across the plume. To obtain the total emission in kg h-1 the resulting total mass across the plume is multiplied with the apparent wind, i.e. a dilution factor corresponding to the vector between the wind and the ship speed. The system was tested in two feasibility studies in the Baltic Sea and Kattegat, from a CASA-212 airplane in 2008 and in the North Sea outside Rotterdam from a Dauphin helicopter in an EU campaign in 2009. In the Baltic Sea the average SO2 emission out of 22 ships was (54 ± 13) kg h-1, and the average NO2 emission was (33 ± 8) kg h-1, out of 13 ships. In the North Sea the average SO2 emission out of 21 ships was (42 ± 11) kg h-1, NO2 was not measured here. The system was able to detect plumes of SO2 in 60% of the measurements when the described method was used. The optical measurement carried out on a passenger ferry on two consecutive days was compared to onboard emission data obtained from analysed fuel content and power consumption. The comparison shows agreement of (-30 ± 14) % and (-41 ± 11) %, respectively, for two days, with equal measurement precision of about 20%, this indicates the presence of systematic error sources that are yet unaccounted for when deriving the flux. Two such error sources are the difficulty in estimating the optical path of the ocean scattered light due to waves, and direct and multiple scattering in the exhaust plume. Rough estimates of these sources have been accounted for in the total

  13. 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

  14. 40 CFR 53.32 - Test procedures for methods for SO2, CO, O3, and NO2.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Test procedures for methods for SO2, CO... for SO2, CO, O3, and NO2. (a) Comparability. Comparability is shown for SO2, CO, O3, and NO2 methods.... (4) A 1-hour measurement consists of the integral of the instantaneous concentration over a...

  15. 40 CFR 53.32 - Test procedures for methods for SO2, CO, O3, and NO2.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 6 2012-07-01 2012-07-01 false Test procedures for methods for SO2, CO... for SO2, CO, O3, and NO2. (a) Comparability. Comparability is shown for SO2, CO, O3, and NO2 methods.... (4) A 1-hour measurement consists of the integral of the instantaneous concentration over a...

  16. 40 CFR 53.32 - Test procedures for methods for SO2, CO, O3, and NO2.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Test procedures for methods for SO2, CO... for SO2, CO, O3, and NO2. (a) Comparability. Comparability is shown for SO2, CO, O3, and NO2 methods.... (4) A 1-hour measurement consists of the integral of the instantaneous concentration over a...

  17. 40 CFR 53.32 - Test procedures for methods for SO2, CO, O3, and NO2.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Test procedures for methods for SO2, CO... for SO2, CO, O3, and NO2. (a) Comparability. Comparability is shown for SO2, CO, O3, and NO2 methods.... (4) A 1-hour measurement consists of the integral of the instantaneous concentration over a...

  18. 40 CFR 53.32 - Test procedures for methods for SO2, CO, O3, and NO2.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Test procedures for methods for SO2, CO... for SO2, CO, O3, and NO2. (a) Comparability. Comparability is shown for SO2, CO, O3, and NO2 methods.... (4) A 1-hour measurement consists of the integral of the instantaneous concentration over a...

  19. 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...

  20. Carbon catalysis in the aqueous oxidation of SO2 by NO2 and air

    NASA Technical Reports Server (NTRS)

    Schryer, D. R.; Schryer, J.; Cofer, W. R., III; Vay, S. A.

    1984-01-01

    Sulfur dioxide and an oxidant gas (air or NO2) were bubbled through aqueous suspensions of both washed and unwashed carbon black as well as through samples of wash water, which contained whatever soluble species were originally present on the carbon, and high-purity water. The sulfate yields obtained showed the washed and unwashed carbon to be equally catalytic for the oxidation of SO2 to sulfate by both oxidants, whereas little sulfate was generated in either the wash water or high-purity water in the absence of carbon. These results indicate that the sulfate yields produced in aqueous suspensions of the carbon studied are due to catalysis by the carbon particles rather than by soluble species dissolved from them.

  1. 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.

  2. 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.

  3. Long path monitoring of tropospheric O3, NO2, H2CO and SO2

    NASA Technical Reports Server (NTRS)

    Vandaele, A. C.; Carleer, M.; Colin, R.; Simon, P. C.

    1994-01-01

    Concentrations of tropospheric O3, NO2, H2CO, and SO2 have been measured on the Campus of the 'Universite Libre de Bruxelles' on a routine basis since October 1990. The long path system consists of a source lamp, a first 30 cm f/8 Cassegrain type telescope which collimates the light onto a slightly parabolic mirror placed on the roof of a building situated 394 m away from the laboratory. The light is sent back into a second 30 cm Cassegrain telescope. This telescope has been modified so that the output beam is a 5 cm diameter parallel beam. This beam is then focused onto the entrance aperture of the BRUKER IFS120HR fourier transform spectrometer. The two telescopes are mounted on alignment devices and the external mirror is equipped with a driving system operated from the laboratory. The choice of the light source (either a 1000 W high pressure 'ozone free' xenon lamp or a 250 W tungsten filament) and of the detector (either a solar blind UV-diode or a silicon diode) depended on the spectral region studied. These regions lie respectively from 26,000 cm(exp -1) to 30,000 cm(exp -1) (260-380 nm) and from 14,000 cm(exp -1) to 30,000 cm(exp -1) (330-700 nm). The spectra have been recorded at the resolution of 16 cm(exp -1) and with a dispersion of 7.7 cm(exp -1). They have been measured during the forward and the backward movements of the mobile mirror, in double sided mode; each spectrum is an average of 2000 scans. The time required to record a spectrum is about 45 minutes. The shape of the raw spectra in the two investigated regions are represented.

  4. Response of needle sulphur and nitrogen concentrations of Scots pine versus Norway spruce to SO2 and NO2.

    PubMed

    Manninen, S; Huttunen, S

    2000-03-01

    The results of two field studies and an open-top chamber fumigation experiment showed that the response of mature Scots pine to SO(2) and NO(2) differed from that of mature Norway spruce. Moreover, the response of pine seedlings to SO(2) and NO(2) differed from that of mature trees. The greater increase in the needle total S concentrations of pine suggested more abundant stomatal uptake of SO(2) compared to spruce. Both pine seedlings and mature trees also seemed to absorb more N from atmospheric deposition. Mature pine was able to assimilate SO(4)(2-) derived from SO(2) into organic S more effectively than mature spruce at the high S and N deposition sites, whereas both pine and spruce seedlings accumulated SO(4)-S under NO(2)+SO(2) exposure. Spruce, in turn, accumulated SO(4)-S even when well supplied with N. Net assimilation of SO(4)(2-) in conifer seedlings was enhanced markedly by elevated temperature. To protect the northern coniferous forests against the harmful effects of S and N deposition, it is recommended that the critical level for SO(2) as a growing season mean be set at 5-10 microg m(-3) and NO(2) at 10-15 microg m(-3), depending on the 'effective temperature sum' and/or whether SO(2) and NO(2) occur alone or in combination. PMID:15092988

  5. 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.

  6. Electron transfer and multi-atom abstraction reactions between atomic metal anions and NO, NO2 and SO2

    NASA Astrophysics Data System (ADS)

    Butson, J. M.; Curtis, S.; Mayer, P. M.

    2016-05-01

    The atomic metal anions Fe-, Cs-, Cu- and Ag- were reacted with NO, NO2 and SO2 to form intact NO-, NO2- and SO2- with no fragmentation. Yields for the molecular anions ranged from 4 to 97% and were found to correlate to the exothermicity of the electron transfer process. Sequential oxygen atom extraction was found to take place between the metal anions and NO and NO2. Reactions between NO2 and Fe- resulted in FeO-, FeO2- and FeO3- while reactions of Cu- with NO2 resulted in CuO- and CuO2-. Reactions of Cu- and Ag- with NO resulted in CuO- and AgO- respectively.

  7. Measurements of NO2, SO2, O3, benzene and toluene using differential optical absorption spectroscopy (DOAS) in Shanghai, China.

    PubMed

    Hao, Nan; Zhou, Bin; Chen, Dan; Sun, Yi; Gao, Song; Chen, Limin

    2006-01-01

    NO2, SO2, O3, benzene, and toluene were measured in Taopu industry park of Shanghai during the period June to August 2003 by differential optical absorption spectroscopy (DOAS) technique. The daily average concentrations of SO2, NO2, and O3 ranged from 5.7 ppb to 40 ppb, 22 ppb to 123 ppb, and 10.6 ppb to 23 ppb respectively. SO2 and NO2 concentrations were found to depend on wind direction. The diurnal variation of NO2 concentrations had two peaks due to traffic emission. Our DOAS measurements of NO2, SO2 and O3 were compared with the conventional measurement instruments (API automatic monitoring instrument). The concept of a percent difference (PD) and linear regression methods were employed to study the difference between DOAS and API instruments. The correlation analysis between PD values and meteorological parameters and analysis of abnormal higher absolute PD values indicated that the lower visibility induced the bad compatibility between the two systems. The results showed that both systems exhibited strong compatibility with good correlation, therefore the DOAS system is able to provide reliable information on distribution patterns of major air pollutants. Average benzene and toluene concentrations were 1.4 and 8.0 ppb respectively. PMID:16948427

  8. A Decade of Change in NO2 and SO2 over the Canadian Oil Sands As Seen from Space

    NASA Technical Reports Server (NTRS)

    Mclinden, Chris A.; Fioletov, Vitali; Krotkov, Nickolay A.; Li, Can; Boersma, K. Folkert; Adams, Cristen

    2015-01-01

    A decade (20052014) of observations from the Ozone Monitoring Instrument (OMI) were used to examine trends in nitrogen dioxide(NO2) and sulfur dioxide (SO2) over a large region of western Canada and the northern United States, with a focus on the Canadian oil sands. In the oil sands, primarily over an area of intensive surface mining, NO2 tropospheric vertical column densities (VCDs) are seen to be increasing by as much as 10year, with the location of the largest trends in a newly developing NO2 lobe well removed from surface monitoring stations. SO2 VCDs in the oil sands have remained approximately constant. The only other significant increase in the region was seen in NO2 over Bakken gas fields in North Dakota which showed increases of up to5yr. By contrast, other locations in the region show substantial declines in both pollutants, providing strong evidence to the efficacy of environmental pollution control measures implemented by both nations. The OMI-derived trends were found to be consistent with those from the Canadian surface monitoring network, although in the case of SO2, it was necessary to apply a correction in order to remove the residual signal from volcanic eruptions present in the OMI data.

  9. A Decade of Change in NO2 and SO2 over the Canadian Oil Sands As Seen from Space.

    PubMed

    McLinden, Chris A; Fioletov, Vitali; Krotkov, Nickolay A; Li, Can; Boersma, K Folkert; Adams, Cristen

    2016-01-01

    A decade (2005-2014) of observations from the Ozone Monitoring Instrument (OMI) were used to examine trends in nitrogen dioxide (NO2) and sulfur dioxide (SO2) over a large region of western Canada and the northern United States, with a focus on the Canadian oil sands. In the oil sands, primarily over an area of intensive surface mining, NO2 tropospheric vertical column densities (VCDs) are seen to be increasing by as much as 10%/year, with the location of the largest trends in a newly developing NO2 "lobe" well removed from surface monitoring stations. SO2 VCDs in the oil sands have remained approximately constant. The only other significant increase in the region was seen in NO2 over Bakken gas fields in North Dakota which showed increases of up to 5%/yr. By contrast, other locations in the region show substantial declines in both pollutants, providing strong evidence to the efficacy of environmental pollution control measures implemented by both nations. The OMI-derived trends were found to be consistent with those from the Canadian surface monitoring network, although in the case of SO2, it was necessary to apply a correction in order to remove the residual signal from volcanic eruptions present in the OMI data. PMID:26642237

  10. Improved Satellite Retrievals of NO2 and SO2 over the Canadian Oil Sands and Comparisons with Surface Measurements

    NASA Technical Reports Server (NTRS)

    McLinden, C. A.; Fioletov, V.; Boersma, K. F.; Kharol, S. K.; Krotkov, N.; Lamsal, L.; Makar, P. A.; Martin, R. V.; Veefkind, J. P.; Yang, K.

    2014-01-01

    Satellite remote sensing is increasingly being used to monitor air quality over localized sources such as the Canadian oil sands. Following an initial study, significantly low biases have been identified in current NO2 and SO2 retrieval products from the Ozone Monitoring Instrument (OMI) satellite sensor over this location resulting from a combination of its rapid development and small spatial scale. Air mass factors (AMFs) used to convert line-of-sight "slant" columns to vertical columns were re-calculated for this region based on updated and higher resolution input information including absorber profiles from a regional-scale (15 km × 15 km resolution) air quality model, higher spatial and temporal resolution surface reflectivity, and an improved treatment of snow. The overall impact of these new Environment Canada (EC) AMFs led to substantial increases in the peak NO2 and SO2 average vertical column density (VCD), occurring over an area of intensive surface mining, by factors of 2 and 1.4, respectively, relative to estimates made with previous AMFs. Comparisons are made with long-term averages of NO2 and SO2 (2005-2011) from in situ surface monitors by using the air quality model to map the OMI VCDs to surface concentrations. This new OMI-EC product is able to capture the spatial distribution of the in situ instruments (slopes of 0.65 to 1.0, correlation coefficients of greater than 0.9). The concentration absolute values from surface network observations were in reasonable agreement, with OMI-EC NO2 and SO2 biased low by roughly 30%. Several complications were addressed including correction for the interference effect in the surface NO2 instruments and smoothing and clear-sky biases in the OMI measurements. Overall these results highlight the importance of using input information that accounts for the spatial and temporal variability of the location of interest when performing retrievals.

  11. 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.

  12. Aura OMI observations of changes in SO2 and NO2 emissions at local, regional and global scales

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    Space-based pollution monitoring from current and planned satellite UV-Vis spectrometers play an increasingly important role in studies of tropospheric chemistry and also air quality applications to help mitigate anthropogenic and natural impacts on sensitive ecosystems, and human health. We present long-term changes in tropospheric SO2 and NO2 over some of the most polluted industrialized regions of the world observed by the Ozone Monitoring Instrument (OMI) onboard NASA's Aura satellite. Using OMI data, we identified about 400 SO2 "hot spots" and estimated emissions from them. In many regions emissions and their ambient pollution levels have decreased significantly, such as over eastern US, Europe and China. OMI observed about 50% reduction in SO2 and NO2 pollution over the North China plain in 2012-2014 that can be attributed to both government efforts to restrain emissions from the power and industrial sectors and the economic slowdown. While much smaller, India's SO2 and NO2 emissions from coal power plants and smelters are growing at a fast pace, increasing by about 200% and 50% from 2005 to 2014. Over Europe and the US OMI-observed trends agree well with those from available in situ measurements of surface concentrations, deposition and emissions data. However, for some regions (e.g., Mexico, Middle East) the emission inventories may be incomplete and OMI can provide emission estimates for missing sources, such as SO2 sources observed over the Persian Gulf. It is essential to continue long-term overlapping satellite data records of air quality with increased spatial and temporal resolution to resolve point pollution sources using oversampling technique. We discuss how Aura OMI pollution measurements and emission estimates will be continued with the US JPSS and European Sentinel series for the next 20 years and further enhanced by the addition of three geostationary UV-VIS instruments.

  13. 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.

  14. O3, SO2, NO2, and UVB measurements in Beijing and Baseline Station of northwestern part of China

    NASA Technical Reports Server (NTRS)

    Guo, Song; Zhou, Xiuji; Zhang, Xiachun

    1994-01-01

    A MKII Brewer ozone spectrometer was used in Beijing from Oct. 1990 to June 1991 to measure O3, SO2 and UVB radiation. And since Nov. 1991 a new MKIV Brewer spectrometer, which can take the measurements of O3, SO2, NO2 and UVB radiation, has been set up in Beijing. The MKII Brewer spectrometer was moved to Qinghai baseline station which is on the Qinghai-tibetean plateau in the northwestern part of China. Both the data in Beijing and Qinghai baseline station has been analyzed and some results will be shown here along with the ozone profiles botained through the Umkehr program given by AES of Canada for the Brewer ozone spectrometer.

  15. NO2 and SO2 dispersion modeling and relative roles of emission sources over Map Ta Phut industrial area, Thailand.

    PubMed

    Chusai, Chatinai; Manomaiphiboon, Kasemsan; Saiyasitpanich, Phirun; Thepanondh, Sarawut

    2012-08-01

    Map Ta Phut industrial area (MA) is the largest industrial complex in Thailand. There has been concern about many air pollutants over this area. Air quality management for the area is known to be difficult, due to lack of understanding of how emissions from different sources or sectors (e.g., industrial, power plant, transportation, and residential) contribute to air quality degradation in the area. In this study, a dispersion study of NO2 and SO2 was conducted using the AERMOD model. The area-specific emission inventories of NOx and SO2 were prepared, including both stack and nonstack sources, and divided into 11 emission groups. Annual simulations were performed for the year 2006. Modeled concentrations were evaluated with observations. Underestimation of both pollutants was Jbund, and stack emission estimates were scaled to improve the modeled results before quantifying relative roles of individual emission groups to ambient concentration overfour selected impacted areas (two are residential and the others are highly industrialized). Two concentration measures (i.e., annual average area-wide concentration or AC, and area-wide robust highest concentration or AR) were used to aggregately represent mean and high-end concentrations Jbfor each individual area, respectively. For AC-NO2, on-road mobile emissions were found to be the largest contributor in the two residential areas (36-38% of total AC-NO2), while petrochemical-industry emissions play the most important role in the two industrialized areas (34-51%). For AR-NO2, biomass burning has the most influence in all impacted areas (>90%) exceptJor one residential area where on-road mobile is the largest (75%). For AC-SO2, the petrochemical industry contributes most in all impacted areas (38-56%). For AR-SO2, the results vary. Since the petrochemical industry was often identified as the major contributor despite not being the largest emitter, air quality workers should pay special attention to this emission group

  16. Four years of ground-based MAX-DOAS observations of aerosols, NO2, SO2 and HCHO in Wuxi, China

    NASA Astrophysics Data System (ADS)

    Wang, Yang; Lampel, Johannes; Wagner, Thomas; Li, Ang; Xie, Pinhua; Wu, Dexia; Beirle, Steffen

    2016-04-01

    Understanding the temporal variation and spatial distribution of the abundances of nitrogen dioxide (NO2), sulphur dioxide (SO2), formaldehyde (HCHO) and aerosols is necessary to study their role in tropospheric chemistry and to estimate their importance among anthropogenic emissions. To accomplish this, we operated a Multi AXis - Differential Optical Absorption Spectroscopy (MAX-DOAS) instrument from May 2011 to Nov 2014 in Wuxi, China. A new inversion algorithm PriAM (profile inversion algorithm of aerosol extinction and trace gas concentration) developed at AIOFM in cooperation with MPIC based on the optimal estimation algorithm is applied to obtain tropospheric profiles of trace gases and aerosols from the long-term observations. The performance of the inversion algorithm is evaluated by comparisons with other independent techniques for a period longer than one year. The cloud effect on the retrieved column densities, surface concentrations and profiles of the trace gases and aerosols is evaluated using of a cloud classification scheme based on the MAX-DOAS measurements themselves. From this study recommendations for the quality of the MAX-DOAS results for different cloud scenarios are given. Further, the MAX-DOAS results are used to characterize the seasonal, diurnal, and weekly variations of NO2, SO2, HCHO and aerosols. Systematic weekly variations are found for all the species, indicating a significant contribution of anthropogenic emissions to the observed abundances. The good correlations between the trace gases and aerosols, especially for HCHO, indicate a significant contribution of secondary aerosols from the precursors to the total aerosol load. We use the wind dependence of the pollutants to identify the dominating sources. High values are observed when the wind comes from the direction of industrial areas.

  17. Evaluating emissions of HCHO, HONO, NO2, and SO2 from point sources using portable Imaging DOAS

    NASA Astrophysics Data System (ADS)

    Pikelnaya, O.; Tsai, C.; Herndon, S. C.; Wood, E. C.; Fu, D.; Lefer, B. L.; Flynn, J. H.; Stutz, J.

    2011-12-01

    Our ability to quantitatively describe urban air pollution to a large extent depends on an accurate understanding of anthropogenic emissions. In areas with a high density of individual point sources of pollution, such as petrochemical facilities with multiple flares or regions with active commercial ship traffic, this is particularly challenging as access to facilities and ships is often restricted. Direct formaldehyde emissions from flares may play an important role for ozone chemistry, acting as an initial radical precursor and enhancing the degradation of co-emitted hydrocarbons. HONO is also recognized as an important OH source throughout the day. However, very little is known about direct HCHO and HONO emissions. Imaging Differential Optical Absorption Spectroscopy (I-DOAS), a relatively new remote sensing technique, provides an opportunity to investigate emissions from these sources from a distance, making this technique attractive for fence-line monitoring. In this presentation, we will describe I-DOAS measurements during the FLAIR campaign in the spring/summer of 2009. We performed measurements outside of various industrial facilities in the larger Houston area as well as in the Houston Ship Channel to visualize and quantify the emissions of HCHO, NO2, HONO, and SO2 from flares of petrochemical facilities and ship smoke stacks. We will present the column density images of pollutant plumes as well as fluxes from individual flares calculated from I-DOAS observations. Fluxes from individual flares and smoke stacks determined from the I-DOAS measurements vary widely in time and by the emission sources. We will also present HONO/NOx ratios in ship smoke stacks derived from the combination of I-DOAS and in-situ measurements, and discuss other trace gas ratios in plumes derived from the I-DOAS observations. Finally, we will show images of HCHO, NO2 and SO2 plumes from control burn forest fires observed in November of 2009 at Vandenberg Air Force Base, Santa Maria

  18. Interconversion of chromium species during air sampling: effects of O3, NO2, SO2, particle matrices, temperature, and humidity.

    PubMed

    Huang, Lihui; Fan, Zhihua Tina; Yu, Chang Ho; Hopke, Philip K; Lioy, Paul J; Buckley, Brian T; Lin, Lin; Ma, Yingjun

    2013-05-01

    The interconversion between Cr(VI), a pulmonary carcinogen, and Cr(III), an essential human nutrient, poses challenges to the measurement of Cr(VI) in airborne particles. Chamber and field tests were conducted to identify the factors affecting Cr(VI)-Cr(III) interconversion in the basic filter medium under typical sampling conditions. In the chamber tests, isotopically enriched (53)Cr(VI) and (50)Cr(III) were spiked on diesel particulate matter (DPM) and secondary organic aerosol (SOA) that were precollected on a basic MCE filter. The filter samples were then exposed to clean air or the air containing SO2 (50 and 160 ppb), 100 ppb O3, or 150 ppb NO2 for 24 h at 16.7 LPM flow rate at designated temperature (20 and 31 °C) and RH (40% and 70%) conditions. Exposure to 160 ppb SO2 had the greatest effect on (53)Cr(VI) reduction, with (53)Cr(VI) recovery of 31.7 ± 15.8% (DPM) and 42.0 ± 7.9% (SOA). DPM and SOA matrix induced (53)Cr(VI) reduction when exposed to clean air while reactive oxygen species in SOA could promote (50)Cr(III) oxidation. Deliquescence when RH increased from 40% to 70% led to conversion of Cr(III) in SOA, whereas oxidized organics in DPM and SOA enhanced hygroscopicity and thus facilitated Cr(VI) reduction. Field tests showed seasonal variation of Cr(VI)-Cr(III) interconversion during sampling. Correction of the interconversion using USEPA method 6800 is recommended to improve accuracy of ambient Cr(VI) measurements. PMID:23550818

  19. Detection of urban O3, NO2, H2CO, and SO2 using Fourier transform spectroscopy

    NASA Astrophysics Data System (ADS)

    Vandaele, Ann Carine; Carleer, M.; Colin, R.; Simon, Paul C.

    1993-02-01

    Concentrations of SO2, NO2, H2CO, and O3 have been measured regularly since October 1990 at the urban site of the Campus of the Universite Libre de Bruxelles, using the differential optical absorption spectroscopy (DOAS) technique associated with a Fourier Transform Spectrometer. The experimental set up has already been described elsewhere (Vandaele et al., 1992). It consists of a source (either a high pressure xenon lamp or a tungsten filament) and an 800 m long path system. The spectra are recorded in the 26,000 - 38,000 cm-1 and 14,000 - 30,000 cm-1 spectral regions, at the dispersion of 7.7 cm-1. The analytical method of the DOAS technique is based on the fact that in atmospheric measurements, it is impossible to obtain an experimental blank spectrum. Therefore, the Beer-Lambert law has to be rewritten as: I equals I'oen(Delta (sigma) d) where I is the measured intensity, Io the measured intensity from which all absorption structures have been removed, n the concentration, d the optical path length, and (Delta) (sigma) the differential absorption cross section of the molecule. Numerous methods for determining I'o exist. Fourier transform filtering has been used in this work. This method defines I'o as the inverse Fourier transform of the lower frequencies portion of the power spectrum of the experimental data. A least squares procedure is then applied in order to determine the concentration of the desired molecules.

  20. Quantitative observation of boundary-layer NO2/SO2 from total-column measurements. New possibilities for space-based observations?

    NASA Astrophysics Data System (ADS)

    Knepp, T.; Pippin, M. R.; Cowen, L.; Murray, J.; Fishman, J.; Neil, D. O.; Martin, R.; Sorkin, A.; Jennings, T.; Szykamn, J.; Martins, D. K.; Thompson, A. M.; Stauffer, R. M.; Herman, J. R.; Cede, A.; Abuhassan, N.

    2011-12-01

    NO2 and SO2 are criteria pollutants that play key roles in the formation of O3 and particulate matter. NO2 is significantly associated with mortality, has far reaching effects on crop yield/photosynthesis (Fishman et al. 2010), atmospheric oxidative capacity, and radiation balance either directly or via its role in ozone/radical chemistry. Major sources of NOx (NO + NO2) and SO2 include motor vehicles, power plants, fossil fuel combustion, burning biomass fuel, and natural sources (e.g. wildfires and volcanoes). GEO-CAPE (Geostationary Coastal and Air Pollution Events mission) will be in a geo-stationary orbit over the United States with improved resolution allowing observation of hourly city-scale emissions. However, estimation of surface NO2/SO2 from total-column data is complicated due to meteorological dynamics and dimensional incongruities. NASA's Chemistry And Physics of the Atmospheric Boundary Layer Experiment (CAPABLE; Langley Research Center, Hampton VA) was established to improve our understanding of these relationships. Collocated at CAPABLE are a direct-sun spectrometer (Pandora), which has previously been shown to have good agreement with OMI's NO2 retrieval, from which column NO2 and SO2 are retrieved with two-minute resolution, and surface NO2/SO2 instruments. Using the EDAS40 model for mixed-depth height we present a methodology for estimating surface NO2 from column observations that accounts for approximately 75% of the variability. Furthermore, Pandora is capable of detecting SO2 emissions from a small power plant approximately 10km NNE of the site, while OMI consistently detects no change in its corresponding pixel. Herein we present our methodology and discuss its applicability to future remote sensing missions and space-based emissions monitoring/regulation.

  1. Nocturnal Vertical Gradients of O3, NO2, NO3, HONO, HCHO, and SO2 in Los Angeles, CA, during CalNex 2010

    NASA Astrophysics Data System (ADS)

    Tsai, J.; Pikelnaya, O.; Hurlock, S. C.; Wong, K.; Cheung, R.; Haman, C. L.; Lefer, B. L.; Stutz, J.

    2010-12-01

    Nocturnal chemistry, through the conversion and removal of air pollutants, plays an important role in determining the initial condition for photochemistry during the following day. In the stable nocturnal boundary layer (NBL) the interplay between suppressed vertical mixing and surface emissions of NOx and VOCs can result in pronounced vertical trace gas profiles. The resulting altitude dependence of nocturnal chemistry makes the interpretation of ground observations challenging. In particular, the quantification of the nocturnal loss of NOx, due to NO3 and N2O5 chemistry, requires observations throughout the entire vertical extent of the NBL. The formation of daytime radical precursors, such as HONO, is also altitude dependent. An accurate assessment of their impact on daytime chemistry requires measurements of their profiles during the night and morning. Here we present observations from the CalNex-LA experiment, which took place from May 15 to June 15, 2010 on the east side of the Los Angeles Basin, CA. A Long-Path Differential Optical Absorption Spectrometer (LP-DOAS) was set up on the roof of the Millikan library (265 m asl, 35m agl) on the campus of the California Institute of Technology. Four retroreflector arrays were mounted about 5 -7 km North-East of the instrument at 310m, 353m, 487m and 788 m asl. The vertical profiles of NO3, HONO, NO2, O3, HCHO, and SO2 were retrieved at altitude intervals of 35-78m, 78-121m, 121-255m and 255-556m above the ground. During many nights vertical gradients were observed, with elevated NO2 and HONO concentrations near the surface and larger ozone and NO3 concentrations aloft. Simultaneous ceilometer observations of the NBL structure show the impact of meteorology on the vertical trace gas distributions. We will discuss the consequences of trace gases gradients on the nocturnal NOx budget.

  2. Field performance evaluation of Maxxam passive samplers for regional monitoring of ambient SO2, NO2 and O3 concentrations in Alberta, Canada

    NASA Astrophysics Data System (ADS)

    Bari, Md. Aynul; Curran, Rhonda Lee T.; Kindzierski, Warren B.

    2015-08-01

    A field performance evaluation of Maxxam passive samplers was carried out for ambient concentrations of sulfur dioxide (SO2), nitrogen dioxide (NO2) and ground-level ozone (O3). Monthly passive and hourly continuous air monitoring data from four regional air monitoring networks in Alberta, Canada were evaluated over a 5-year period (2006-2010). Monthly concentrations were relatively low, ranging from 0.1 to 3.9 ppb, 0.2-18.1 ppb and 10.1-56.1 ppb for SO2, NO2 and O3, respectively. From duplicate passive sampling, geometric mean precision values were 17.9%, 14.8% and 4.7% for SO2, NO2 and O3, respectively. Geometric mean of the relative error (as a measure of accuracy) was 30% (median = 33%, interquartile range, IQR 15-63%) for SO2 and 32% (median = 40%, IQR = 25-64%) for NO2. O3 measurements had a better measure of accuracy with a geometic mean relative error of 12% (median = 17%, IQR = 8-27%) and met the acceptable level recommended by United States National Institute of Safety and Health (NIOSH) and the European Union (EU) Directive (±25%). From reduced major axis (RMA) analysis, bias (systematic error) is apparent in the Maxxam passive samplers in the field resulting in overestimation of ambient SO2 and O3 concentrations and underestimation of NO2 concentrations relative to continuous analyzers. Seasonal influences were observed for accuracy of passive SO2 and O3 measurements. A poor association was found between passive versus continuous concentrations for SO2 and O3 during the winter and the summer, respectively.

  3. 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

  4. A model-based analysis of SO2 and NO2 dynamics from coal-fired power plants under representative synoptic circulation types over the Iberian Peninsula.

    PubMed

    Valverde, Víctor; Pay, María T; Baldasano, José M

    2016-01-15

    Emissions of SO2 and NO2 from coal-fired power plants are a significant source of air pollution. In order to typify the power plants' plumes dynamics and quantify their contribution to air quality, a comprehensive characterisation of seven coal-fired power plant plumes has been performed under six representative circulation types (CTs) identified by means of a synoptic classification over the Iberian Peninsula. The emission and the transport of SO2 and NO2 have been simulated with the CALIOPE air quality forecasting system that couples the HERMES emission model for Spain and WRF and CMAQ models. For the facilities located in continental and Atlantic areas (As Pontes, Aboño, and Compostilla) the synoptic advection controls pollutant transport, however for power plants located along the Mediterranean or over complex-terrains (Guardo, Andorra, Carboneras, and Los Barrios), plume dynamics are driven by a combination of synoptic and mesoscale mountain-valley and sea-land breezes. The contribution of power plants to surface concentration occurs mainly close to the source (<20 km) related to a fumigation process when the emission injection takes place within the planetary boundary layer reaching up to 55 μg SO2 m(-3) and 32 μg NO2 m(-3). However, the SO2 and NO2 plumes can reach long distances (>250 km from the sources) especially for CTs characterised by Atlantic advection. PMID:26433330

  5. 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

  6. Operational O3M-SAF trace gas column products: GOME-2 ozone, NO2, BrO, SO2 and CH2O

    NASA Astrophysics Data System (ADS)

    Hao, Nan; Valks, Pieter; Loyola, Diego; de Smedt, Isabelle; van Roozendael, Michel; Theys, Nicolas; Rix, Meike; Koukouli, Mariliza; Balis, Dimitris; Lambert, Jean-Christopher; Pinardi, Gaia; Zimmer, Walter; Emmadi, Sunil

    This contribution focuses on the operational GOME-2 trace gas column products developed at the German Aerospace Centre, in the framework of EUMETSAT's Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M-SAF). We present an overview of the retrieval algorithms and exemplary results for ozone, NO2, BrO, SO2 and CH2O. These trace gas column products are retrieved with the GOME Data Processor (GDP) version 4.x algorithm and the UPAS system. Total ozone and NO2 are retrieved with the Differential Optical Absorption Spectroscopy (DOAS) method using the UV wavelength region around 330 nm and 435 nm respectively. An additional algorithm is applied to retrieve the tropospheric NO2 column for polluted con-ditions. The operational ozone and NO2 products are available for the users in near real time, i.e. within two hours after sensing. SO2 emissions from volcanic and anthropogenic sources can be measured by GOME-2 around 320 nm. For BrO and CH2O, optimal DOAS fitting windows have been determined for GOME-2 in the UV wavelength region. The GOME-2 ozone, total and tropospheric NO2, SO2, BrO, CH2O and cloud products from DLR have reached the operational EUMETSAT O3M-SAF status. All these products are routinely available to the users via EUMETCast, WMO/GTS and FTP in HDF5 and BUFR format. We present initial validation results for GOME-2 products using ground-based measurements, as well as comparisons with other satellite products, such as those from SCIAMACHY and OMI. The use of tropospheric NO2, SO2 and CH2O columns for air quality applications will be presented, including temporal evolution analyses for China. Furthermore, we will show examples of BrO under polar winter conditions.

  7. Benzene, toluene, ozone, NO 2 and SO 2 measurements in an urban street canyon in Thessaloniki, Greece

    NASA Astrophysics Data System (ADS)

    Kourtidis, Kostas A.; Ziomas, Ioannis; Zerefos, Christos; Kosmidis, Evangelos; Symeonidis, Panayotis; Christophilopoulos, Epaminondas; Karathanassis, Stavros; Mploutsos, Antonios

    Benzene, toluene, sulphur dioxide, ozone and nitrogen dioxide were measured at a mean level of 13.5 m above ground in a narrow, four-lane street canyon (height 30 m, width 20 m) in Thessaloniki, Greece during the period January-July 1997 by means of a commercial differential optical absorption spectrometer (OPSIS DOAS). Primary pollutant levels were found to be 2.5-4.4 times higher during the cold part of the year than during the warm part of the year, the winter/summer ratio increasing with the reaction rate constant with OH for each of the measured species. Ozone, on the other hand, exhibited a winter/summer ratio of 0.36. NO 2 originates from both primary and secondary sources; its winter/summer concentration ratio of 1.4 lies, therefore, between those of primary pollutants and ozone. Pollution levels were influenced considerably by wind speed, while for the street canyon under study wind direction did not influence pollutant levels considerably. While primary pollution was found to decrease with increasing wind speed, ozone increased. Benzene mean levels during the study period were around 6 ppb and hence much higher than the EU annual limit value of 5 μg m -3 (1.44 ppb at STP). Toluene mean levels were around 14 ppb and hence also several times above the WHO recommendation of 2 ppb for 24 h. The apportionment of traffic emissions in four time zones used in most inventories in urban airshed models was tested using benzene and toluene measurements at low (<1 m s -1) wind speeds. The agreement between model emissions and calculated emissions apportionment into the four time zones was good, except for Zone D (23:00-1:59), where model inventory emissions were somewhat too low.

  8. Operational O3M-SAF trace-gas column products: GOME-2 tropospheric NO2, SO2 and BrO

    NASA Astrophysics Data System (ADS)

    Valks, P.; Hao, N.; Rix, M.; Lambert, J.-C.; Pinardi, G.; van Roozendael, M.; Theys, N.; Loyola, D.

    2009-04-01

    This contribution focuses on the operational GOME-2 trace-gas column products developed at the German Aerospace Centre, in the framework of EUMETSAT's Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M-SAF). We present the algorithms and exemplary results of tropospheric NO2, total BrO and SO2. These trace-gas column products are retrieved from GOME-2 solar backscattered measurements in the UV/VIS wavelength region, using the Differential Optical Absorption Spectroscopy (DOAS) method. Total NO2 is routinely retrieved with the GOME Data Processor (GDP) version 4.2 using the 425-450 nm wavelength region. An additional algorithm is applied to derive the tropospheric NO2 column for polluted conditions: after subtracting the estimated stratospheric component from the total column, the tropospheric NO2 column is determined using an air mass factor based on monthly climatological NO2 profiles from the MOZART-2 model. SO2 emissions from volcanic and anthropogenic sources can be measured by GOME-2 using the UV wavelength region around 320 nm. With GOME-2, it is possible to detect and track volcanic SO2 in near-real time and on a global scale, which is of particular importance for volcanic early warning services. For the GOME-2 retrieval of the total BrO column, current research focuses on the optimisation of the DOAS fitting window in the UV wavelength region. BrO columns retrieved from the baseline GOME fitting window (344.6-359 nm) show relatively large noise levels. Therefore, the use of an alternative fitting window has been analysed. More than two years of tropospheric NO2, total BrO and SO2 measurements are now available from GOME-2. We present initial validation results using ground-based measurements, as well as comparisons with other satellite products, such as those from SCIAMACHY and OMI. The use of tropospheric NO2 columns for air quality applications will be presented. We will show examples of BrO from volcanic eruptions and under

  9. MAX-DOAS measurements and satellite validation of tropospheric NO2 and SO2 vertical column densities at a rural site of North China

    NASA Astrophysics Data System (ADS)

    Jin, Junli; Ma, Jianzhong; Lin, Weili; Zhao, Huarong; Shaiganfar, Reza; Beirle, Steffen; Wagner, Thomas

    2016-05-01

    North China (NC), namely Huabei in Chinese, is one of the most severely polluted regions in China, and the air pollution issues in this region have received a worldwide attention. We performed ground-based Multi Axis Differential Absorption Spectroscopy (MAX-DOAS) measurements at Gucheng, (39°08‧N, 115°40‧E), a rural site of North China about 110 km southwest of Beijing, from September 2008 to September 2010. The tropospheric vertical column densities (VCDs) of NO2 and SO2 were retrieved using the so-called geometric approximation. The results show that the tropospheric NO2 and SO2 VCDs over NC have nearly the same seasonal variation pattern, with the maximum in winter and minimum in summer, while their diurnal variations are different. We also compared the tropospheric NO2 and SO2 VCDs from our MAX-DOAS measurements with several products of corresponding OMI (Ozone Monitoring Instrument) satellite observations. While in summer good agreement is found, the satellite observations systematically underestimate the tropospheric NO2 in winter over the polluted rural area of NC, probably mostly due to the so called aerosol shielding effect. In contrast, for SO2 no such clear conclusion can be drawn, probably owing to the larger uncertainties from MAX-DOAS and in particular satellite retrievals. This indicates that improvements of the retrieval algorithm for MAX-DOAS and off-line corrections of satellite measurements for the tropospheric SO2 VCDs should be given more emphasis in the future.

  10. Satellite-observed NO2, SO2, and HCHO Vertical Column Densities in East Asia: Recent Changes and Comparisons with Regional Model

    NASA Astrophysics Data System (ADS)

    Kim, H. C.; Lee, P.; Kim, S.; Mok, J.; Yoo, H. L.; Bae, C.; Kim, B. U.; Lim, Y. K.; Woo, J. H.; Park, R.

    2015-12-01

    This study reports the recent changes in tropospheric NO2, SO2, and HCHO vertical column densities (VCD) in East Asia observed from multiple satellites, highlighting especially the annual trend changes of NO2 and SO2 over Beijing-Tianjin-Hebei (BTH) region of China since 2010. Tropospheric VCD data from Global Ozone Monitoring Experiment (GOME), SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY), Ozone Monitoring Instrument (OMI) and GOME-2, retrieved from the Royal Netherlands Meteorological Institute (KNMI) and OMI National Aeronautics and Space Administration (NASA) standard products, are utilized to investigate the annual trends of NO2, SO2, and HCHO VCDs from 2001 to 2015. They are also compared with simulations from Community Multi-scale Air Quality Model (CMAQ) based forecast system by the Integrated Multi-scale Air Quality System for Korea (IMAQS-K) of Ajou University. Until 2011, the changes in NO2 VCD over East Asian countries agree well with the findings of previous research, including the impact of the economic downturn during 2008-2009 and the subsequent quick recovery in China. After peaking in 2011, the NO2 VCD observations from active instruments (OMI and GOME-2) over China started to show a slower decreasing trend, mostly led by the rapid changes in the BTH region in northern China. On the other hand, SO2 started to decline earlier, from 2007, but inclined back from 2010 to 2012, and then back to declining trend since 2012. While satellite observations show dramatic recent changes, the model could not reproduce those changes mostly due to its use of fixed emission inventory. We conclude that rapid update of latest emission inventory is necessary for an accurate forecast of regional air quality in east Asia, especially for upcoming international sports events in PyeongChang (Korea), Tokyo (Japan) and Beijing (China) in 2018, 2020 and 2022, respectively.

  11. Operational O3M-SAF trace gas column products: GOME-2 NO2, BrO, SO2 and CH2O

    NASA Astrophysics Data System (ADS)

    Hao, Nan; Valks, P.; de Smedt, I.; Emmadi, S.; Lambert, J.-C.; Loyola, D.; Pinardi, G.; Rix, M.; van Roozendael, M.; They, N.

    2010-05-01

    This contribution focuses on the operational GOME-2 trace gas column products developed at the German Aerospace Centre, in the framework of EUMETSAT's Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M-SAF). We present an overview of the retrieval algorithms and exemplary results for NO2, BrO, SO2 and CH2O. These trace gas column products are retrieved with the GOME Data Processor (GDP) version 4.4 using the Differential Optical Absorption Spectroscopy (DOAS) method in the UV and VIS wavelength regions. Total NO2 is retrieved in the 425-450 nm and an additional algorithm is applied to retrieve the tropospheric NO2 column for polluted conditions. The operational GOME-2 NO2 product is available for the users in near real time, i.e. within two hours after sensing. SO2 emissions from volcanic and anthropogenic sources can be measured by GOME-2 using the UV wavelength region around 320 nm. For BrO and CH2O, optimal DOAS fitting windows have been determined for GOME-2 in the UV wavelength region. The GOME-2 SO2, BrO and CH2O products have reached the operational O3M-SAF status, and are routinely available to the users. More than three years of operational trace gas column measurements are now available from GOME-2. We present initial validation results using ground-based measurements, as well as comparisons with other satellite products, such as those from SCIAMACHY and OMI. The use of tropospheric NO2, SO2 and CH2O columns for air quality applications will be presented, including temporal evolution analyses for China. Furthermore, we will show examples of BrO under polar winter conditions.

  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. A four-channel portable solar radiometer for measuring particulate and/or aerosol opacity and concentration of NO2 and SO2 in stack plumes

    NASA Technical Reports Server (NTRS)

    Exton, R. J.; Gregory, R. W.

    1976-01-01

    Solar absorption radiometry has been investigated as a method of measuring stackplume effluents. A simple and inexpensive instrument was constructed for observing the sun at four wavelengths: 800, 600, 400, and 310 nm. Higher wavelength channels measured the effect of the particulates and NO2, and an ultraviolet channel measured the contribution of SO2 to the attenuation. Stack-plume measurements of opacity and concentration of NO2 and SO2 were in basic agreement with in-stack measurements. The major limitation on the use of the radiometer is the requirement for an accessible viewing position which allows the sun-plume-observer relationship to be attained. It was concluded that the solar radiometer offers an inexpensive method for monitoring plume effluents when the viewing position is not restricted.

  14. Scanning and mobile multi-axis DOAS measurements of SO2 and NO2 emissions from an electric power plant in Montevideo, Uruguay

    NASA Astrophysics Data System (ADS)

    Frins, E.; Bobrowski, N.; Osorio, M.; Casaballe, N.; Belsterli, G.; Wagner, T.; Platt, U.

    2014-12-01

    In March 2012 the emissions of NO2 and SO2 from a power station located on the east side of Montevideo Bay (34° 53‧ 10″ S, 56° 11‧ 49″ W) were quantified by simultaneously using mobile and scanning multi-axis differential optical absorption spectroscopy (in the following mobile DOAS and scanning DOAS, respectively). The facility produces electricity by means of two technologies: internal combustion motors and steam generators. The motors are powered with centrifuged heavy oil and produce a maximum power of 80 MW approximately. The steam generators produce approximately 305 MW and are powered with heavy fuel oil. We compare the emissions obtained from the measured slant column densities (mobile DOAS and scanning DOAS) with the emissions estimated from fuel mass balance. On one occasion it was possible to distinguish between the two types of sources, observing two plumes with different SO2 and NO2 emission rates. During the period of the campaign the mean SO2 emission flux was determined to be 0.36 (±0.12) kg s-1 and 0.26 (±0.09) kg s-1 retrieved from mobile and scanning DOAS respectively, while the calculated SO2 flux from the sulphur content of the fuel was 0.34 (±0.03) kg s-1. The average NO2 flux calculated from mobile DOAS was determined to be 11 (±3) × 10-3 kg s-1. Using the scanning DOAS approach a mean NO2 flux of 5.4 (±1.7) × 10-3 kg s-1 was obtained, which is significantly lower than by the mobile measurements. The differences between the results of mobile MAX-DOAS measurements and scanning DOAS measurements are most probably caused by the variability and the limited knowledge of the wind speed and direction.

  15. 40 CFR Figure C-1 to Subpart C of... - Suggested Format for Reporting Test Results for Methods for SO 2, CO, O 3, NO 2

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Results for Methods for SO 2, CO, O 3, NO 2 C Figure C-1 to Subpart C of Part 53 Protection of Environment... Pt. 53, Subpt. C, Fig. C-1 Figure C-1 to Subpart C of Part 53—Suggested Format for Reporting Test... Difference Table C-1 spec. Pass or fail Low 1 ____ pPM 2 to ____ pPM 3 4 5 6 Medium 1 ____ pPM 2 to ____...

  16. 40 CFR Figure C-1 to Subpart C of... - Suggested Format for Reporting Test Results for Methods for SO 2, CO, O 3, NO 2

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Results for Methods for SO 2, CO, O 3, NO 2 C Figure C-1 to Subpart C of Part 53 Protection of Environment... Pt. 53, Subpt. C, Fig. C-1 Figure C-1 to Subpart C of Part 53—Suggested Format for Reporting Test... Difference Table C-1 spec. Pass or fail Low 1 ____ ppm 2 to ____ ppm 3 4 5 6 Medium 1 ____ ppm 2 to ____...

  17. 40 CFR Figure C-1 to Subpart C of... - Suggested Format for Reporting Test Results for Methods for SO 2, CO, O 3, NO 2

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Results for Methods for SO 2, CO, O 3, NO 2 C Figure C-1 to Subpart C of Part 53 Protection of Environment... Pt. 53, Subpt. C, Fig. C-1 Figure C-1 to Subpart C of Part 53—Suggested Format for Reporting Test... Difference Table C-1 spec. Pass or fail Low 1 ____ ppm 2 to ____ ppm 3 4 5 6 Medium 1 ____ ppm 2 to ____...

  18. 40 CFR Figure C-1 to Subpart C of... - Suggested Format for Reporting Test Results for Methods for SO 2, CO, O 3, NO 2

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Results for Methods for SO 2, CO, O 3, NO 2 C Figure C-1 to Subpart C of Part 53 Protection of Environment... Pt. 53, Subpt. C, Fig. C-1 Figure C-1 to Subpart C of Part 53—Suggested Format for Reporting Test... Difference Table C-1 spec. Pass or fail Low 1 ____ ppm 2 to ____ ppm 3 4 5 6 Medium 1 ____ ppm 2 to ____...

  19. 40 CFR Figure C-1 to Subpart C of... - Suggested Format for Reporting Test Results for Methods for SO 2, CO, O 3, NO 2

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Results for Methods for SO 2, CO, O 3, NO 2 C Figure C-1 to Subpart C of Part 53 Protection of Environment... Pt. 53, Subpt. C, Fig. C-1 Figure C-1 to Subpart C of Part 53—Suggested Format for Reporting Test... Difference Table C-1 spec. Pass or fail Low 1 ____ ppm 2 to ____ ppm 3 4 5 6 Medium 1 ____ ppm 2 to ____...

  20. Case studies on summertime measurements of O3, NO2, and SO2 with a DOAS system in an urban semi-industrial region in Athens, Greece.

    PubMed

    Psiloglou, Betaasil E; Larissi, Ioanna K; Petrakis, Muichael; Paliatsos, Athanasios G; Antoniou, Alphantonis; Viras, Loisos G

    2013-09-01

    The objective of this study is to analyze the concentrations of SO2, NO2, and O3 measured by a Differential Optical Absorption Spectroscopy (DOAS) system that was operating at the campus of Technological Education Institute of Piraeus during 2008 and 2009 warm periods (July to September) in relation to the prevailing meteorological conditions. The DOAS system was operating in a particularly polluted area of the West part of Attica basin on a continuous basis, measuring the concentration levels of the main pollutants (O3, NO2, and SO2) as well as aromatic hydrocarbon substances (benzene, toluene, and xylene). According to the analysis, the SO2 concentration levels at this measuring site are rather high and this may be attributed to the characteristics of this measuring site. Proximity of roadways and local circulation are just some of the factors that can affect the concentration levels of monitoring of pollutant concentrations such as NO2 and surface ozone. The results provide evidence for the occurrence of an atmospheric phenomenon that produces higher ozone concentrations during weekends despite lower concentrations of ozone precursors. This phenomenon is known as the weekend effect. PMID:23430070

  1. Evaluation of Chronic Obstructive Pulmonary Disease (COPD) attributed to atmospheric O3, NO2, and SO2 using Air Q Model (2011-2012 year).

    PubMed

    Ghanbari Ghozikali, Mohammad; Heibati, Behzad; Naddafi, Kazem; Kloog, Itai; Oliveri Conti, Gea; Polosa, Riccardo; Ferrante, Margherita

    2016-01-01

    Chronic obstructive pulmonary disease (COPD) is an important disease worldwide characterized by chronically poor airflow. The economic burden of COPD on any society can be enormous if not managed. We applied the approach proposed by the World Health Organization (WHO) using the AirQ2.2.3 software developed by the WHO European Center for Environment and Health on air pollutants in Tabriz (Iran) (2011-2012 year). A 1h average of concentrations of ozone (O3), daily average concentrations of nitrogen dioxide (NO2) and sulfur dioxide (SO2) were used to assess human exposure and health effect in terms of attributable proportion of the health outcome and annual number of excess cases of Hospital Admissions for COPD (HA COPD). The results of this study showed that 2% (95% CI: 0.8-3.1%) of HA COPD were attributed to O3 concentrations over 10 μg/m(3). In addition, 0.7 % (95% CI: 0.1-1.8%) and 0.5% (95% CI: 0-1%) of HA COPD were attributed to NO2 and SO2 concentrations over 10 μg/m(3) respectively. In this study, we have shown that O3, NO2 and SO2 have a significant impact on COPD hospitalization. Given these results the policy decisions are needed in order to reduce the chronic pulmonary diseases caused by air pollution and furthermore better quantification studies are recommended. PMID:26599588

  2. 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

  3. 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.

  4. Ship-based MAX-DOAS measurements of tropospheric NO2 and SO2 in the South China and Sulu Sea

    NASA Astrophysics Data System (ADS)

    Schreier, S. F.; Peters, E.; Richter, A.; Lampel, J.; Wittrock, F.; Burrows, J. P.

    2015-02-01

    In November 2011, ship-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements were performed within the SHIVA campaign on board RV Sonne in the South China and Sulu Sea. Spectral measurements for a total of eleven days could be used to retrieve tropospheric slant column densities (SCDs) of nitrogen dioxide (NO2) and sulfur dioxide (SO2) in the marine environment. The NO2 fit was performed following recommendations developed during the CINDI campaign and adapted for the ship-based measurements. We found that the inclusion of a cross section for liquid water and an empirical correction spectrum accounting for the effects of liquid water and vibrational Raman scattering (VRS) slightly improved the NO2 fit quality, especially at lower elevation angles and for lower NO2 levels. The conversion of SCDs into tropospheric NO2 vertical columns (TVC NO2) has been achieved using both a simple geometric approach and the Bremian advanced MAX-DOAS Retrieval Algorithm (BREAM), which is based on the optimal estimation method and accounts for atmospheric radiative transfer. We found good agreement between the geometric approach using the 15° measurements and BREAM, revealing that measurements at 15° elevation angle can be used for retrieving TVC NO2 in tropical marine environments when SZA is smaller than 75°. As expected, the values of TVC NO2 were generally low (<0.5 × 1015 molec cm-2) when no sources of NOx were in proximity to the RV Sonne. However, we found increased values of TVC NO2 (>2 × 1015 molec cm-2) in the morning when the RV Sonne was heading along the coast of Borneo. This is in good agreement with satellite measurements. The results of the profile retrieval show that the boundary layer values of NO2 are <30 pptv in the open and clean tropical marine environment. Interestingly, we also found elevated tropospheric SO2 amounts for measurements taken in a busy shipping lane, consistent with the time series of tropospheric NO2.

  5. 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.

  6. Vertical Profiles of SO2 and NO2 in the Alberta Oil Sands: MAX-DOAS Measurements and Comparison to in-situ Instrumentation

    NASA Astrophysics Data System (ADS)

    Davis, Zoe; Lobo, Akshay; McLaren, Robert

    2015-04-01

    Understanding the levels of industrially emitted gas pollutants in the Alberta oil sands is essential to making quality environmental management decisions but is currently limited due to scarcity of top-down quantification studies. Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements of nitrogen dioxide (NO2) and sulfur dioxide (SO2) , important tropospheric trace gas pollutants, contributes to improved knowledge of these pollutants' levels, vertical distributions and chemical transformations. A mini-MAX-DOAS instrument measured spectra at multiple viewing elevation angles in order to retrieve NO2 and SO2 differential slant column densities (dSCDs) at an Environment Canada research site north of Fort McMurray, Alberta in the fall of 2013. For the first time in the oil sands, tropospheric vertical profiles of NO2 and SO2 were retrieved by applying the optimal estimation technique to the MAX-DOAS measurements. The DOAS fit retrievals of SO2 dSCDs were validated by comparison with retrievals obtained with a quartz calibration cell with known SO2 SCD placed in front of the MAX-DOAS telescope at multiple elevation angles on a clean day. Retrieved SO2 dSCDs varied significantly from the true value depending on the chosen wavelength fitting interval. At the lowest wavelength intervals, interference by stray light and O3 differential structures significantly reduced dSCDs and caused an elevation angle dependence. These results indicate that MAX-DOAS dSCD retrieval settings, particularly for weak absorbers with differential absorption structures in low-intensity spectral regions, must be chosen carefully in order to achieve the most accurate results. Tropospheric vertical column densities (VCDs) and vertical profile retrievals of NO2, SO2 and aerosol extinction during significant pollution events will be illustrated. Trace gas vertical profiles exhibited significant variability between days and at different times of day and were often spatially

  7. A comprehensive study over the recent important reduction in SO2 and NO2 emissions from the power plants located in S-E Europe using space observations

    NASA Astrophysics Data System (ADS)

    Bocǎnealǎ, Corina; Constantin, Daniel-Eduard; Theys, Nicolas; Merlaud, Alexis; Van Roozendael, Michel

    2016-04-01

    The aim of this study is to investigate the recent important reduction of atmospheric SO2 and NO2 emissions from several power plants located in S-E Europe during 2005-2014 using space observations. The study is focused over three large power plants which are located in Romania and Bulgaria: Turceni (44.66°N, 23.38°E), Rovinari (44.9°N, 23.15°E) and Stara Zagora (42.43°N, 25.65°E). The space observations used in this work are based on OMI (Ozone Monitoring Instrument) and GOME-2 (Global Ozone Monitoring Experiment Measurements) measurements. The results obtained using data from satellites are compared with in-situ observations and calculated emissions. The OMI and GOME-2 observed SO2 and NO2 content is well correlated with the in-situ data and calculated SO2 and NOx emissions. This study investigates the potential of using satellite observations as an instrument to check quality air as a standard procedure by governmental and non-governmental institutions. To this aim, we compared the emissions calculated from ground and space with the European Directive 2001/80/EC which refers to the limitation of emissions of certain pollutants by large combustion plants.

  8. Spatiotemporal variations of air pollutants (O3, NO2, SO2, CO, PM10, and VOCs) with land-use types

    NASA Astrophysics Data System (ADS)

    Yoo, J.-M.; Jeong, M.-J.; Kim, D.; Stockwell, W. R.; Yang, J.-H.; Shin, H.-W.; Lee, M.-I.; Song, C.-K.; Lee, S.-D.

    2015-09-01

    The spatiotemporal variations of surface air pollutants (O3, NO2, SO2, CO, and PM10) with four land-use types, residence (R), commerce (C), industry (I) and greenbelt (G), have been investigated at 283 stations in South Korea during 2002-2013, using routinely observed data. The volatile organic compound (VOC) data at nine photochemical pollutant monitoring stations available since 2007 were utilized in order to examine their effect on the ozone chemistry. The land-use types, set by the Korean government, were generally consistent with the satellite-derived land covers and with the previous result showing anti-correlation between O3 and NO2 in diverse urban areas. The relationship between the two pollutants in the Seoul Metropolitan Area (SMA) residence land-use areas was substantially different from that outside of the SMA, probably due to the local differences in vehicle emissions. The highest concentrations of air pollutants in the diurnal, weekly, and annual cycles were found in industry for SO2 and PMPM10, in commerce for NO2 and CO, and in greenbelt for O3. The concentrations of air pollutants, except for O3, were generally higher in big cities during weekdays, while O3 showed its peak in suburban areas or small cities during weekends. The weekly cycle and trends of O3 were significantly out of phase with those of NO2, particularly in the residential and commercial areas, suggesting that vehicle emission was a major source in those areas. The ratios of VOCs to NO2 for each of the land-use types were in the order of I (10.2) > C (8.7) > G (3.9) > R (3.6), suggesting that most areas in South Korea were likely to be VOC-limited for ozone chemistry. The pollutants (NO2, SO2, CO, and PMPM10 except for O3 have decreased, most likely due to the effective government control. The total oxidant values (OX = O3 + NO2) with the land-use types were analyzed for the local and regional (or background) contributions of O3, respectively, and the order of OX (ppb) was C (57

  9. Transverse approach between real world concentrations of SO2, NO2, BTEX, aldehyde emissions and corrosion in the Grand Mare tunnel.

    PubMed

    Ameur-Bouddabbous, I; Kasperek, J; Barbier, A; Harel, F; Hannoyer, B

    2012-01-01

    With regard to automotive traffic, a tunnel-type semi enclosed atmosphere is characterized by a higher concentration of gaseous pollutants than on urban traffic roads and highlights the gaseous effluent species having an impact on material degradation. Therefore, a transverse approach between air quality and its consequences upon the longevity of materials is necessary, implying better knowledge of tunnel atmosphere and a better understanding of material degradation inside a tunnel for operating administration. Gaseous pollutant measurements carried out in a road tunnel in Rouen (Normandy) give the real world traffic concentrations of experimental exposure conditions. The sampling campaigns, achieved in summer and winter include SO2, NO2, BTEX and aldehyde analyses. Effluent profiles in the upward and downward tubes have been established. The current work shows that SO2, NO2, formaldehyde, acetaldehyde, propanal and butanal must be considered in the degradation process of materials in a stuffy environment. As regards NO2, its concentration depends on the modification of the automotive fleet. The total aldehyde concentrations indicate no particular trend between the two bores. Formaldehyde, acetaldehyde, propanal, butanal and acrolein species are the most abundant species emitted by vehicles and represent 90% to 95% of the total aldehyde emissions. PMID:23513445

  10. 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

  11. 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.

  12. Inter-comparison of MAX-DOAS Retrieved Vertical Profiles of Aerosol Extinction, SO2 and NO2 in the Alberta Oil Sands with LIDAR Data and GEM-MACH Air Quality Model.

    NASA Astrophysics Data System (ADS)

    Davis, Zoe; Friess, Udo; Strawbridge, Kevin; Whiteway, James; Aggarwal, Monika; Makar, Paul; Li, Shao-Meng; O'Brien, Jason; Baray, Sabour; Schnitzler, Elijah; Olfert, Jason S.; Osthoff, Hans D.; Lobo, Akshay; McLaren, Robert

    2016-04-01

    Understanding industrial emissions of trace gas pollutants in the Alberta oil sands is essential to maintaining air quality standards and informing public policy. Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements of trace gases can improve knowledge of pollutant levels, vertical distribution and chemical transformation. During an intensive air measurement campaign to study emissions, transport, transformation and deposition of oil sands air pollutants from August to September of 2013, a MAX-DOAS instrument was deployed at a site north of Fort McMurray, Alberta to determine the vertical profiles of aerosol extinction, NO2 and SO2 through retrieval from the MAX-DOAS spectral measurements using an optimal estimation method. The large complement of data collected from multiple instruments deployed during this field campaign provides a unique opportunity to validate and characterize the performance of the MAX-DOAS vertical profile retrievals. Aerosol extinction profiles determined from two Light Detection and Ranging (LIDAR) instruments, one collocated and the other on a Twin Otter aircraft that flew over the site during the study, will be compared to the MAX-DOAS aerosol extinction profile retrievals. Vertical profiles of NO2 and SO2 retrieved from the MAX-DOAS measurements will be further compared with the composite vertical profiles measured from the flights of a second aircraft, the NRC-Convair 580, over the field site during the same measurement period. Finally, the MAX-DOAS retrieved tropospheric vertical column densities (VCDs) of SO2 and NO2 will be compared to the predicted VCDs from Environment and Climate Change Canada's Global Environmental Multi-scale - Modelling Air quality and Chemistry (GEM-MACH) air quality model over the grid cell containing the field site. Emission estimates of SO2 from the major oil mining facility Syncrude Mildred Lake using the MAX-DOAS VCD results, validated through the detailed characterization above

  13. Differential optical absorption spectrometer measurement of NO 2, SO 2, O 3, HCHO and aromatic volatile organics in ambient air of Kaohsiung Petroleum Refinery in Taiwan

    NASA Astrophysics Data System (ADS)

    Chiu, Kong Hwa; Sree, Usha; Hong Tseng, Sen; Wu, Chien-Hou; Lo, Jiunn-Guang

    UV-differential optical absorption spectrometer (DOAS) technique is considered as a promising technique to detect gaseous pollutants and was applied to conduct one-week continuous measurements in the Chinese Petroleum (CPC) refinery plant located in Lin Yuan industrial park of Kaohsiung, Southern Taiwan. With the combination of local meteorological information, including solar radiation, wind direction and speed, the results showed that the concentrations of aromatic compounds and formaldehyde (HCHO) were higher at night while the values of ozone, NO 2 and SO 2 were high during the day. The major source of aromatics was the aromatic extraction unit in the refinery while NO 2 and SO 2 were mainly emitted from chimneys with not very high average concentrations. Formaldehyde concentration was above 50 ppbv during night. There exists an apparent correlation between the variation of ground-level ozone concentration and photochemical reactions. The results indicate that in addition to benzene and toluene, ozone is a deleterious pollutant. The commercial DOAS system provides reliable information on distribution patterns of major air pollutants depending on their concentration levels in ambient air.

  14. A Longitudinal Study of Sick Building Syndrome (SBS) among Pupils in Relation to SO2, NO2, O3 and PM10 in Schools in China

    PubMed Central

    Zhang, Xin; Li, Fan; Zhang, Li; Zhao, Zhuohui; Norback, Dan

    2014-01-01

    There are fewer longitudinal studies from China on symptoms as described for the sick building syndrome (SBS). Here, we performed a two-year prospective study and investigated associations between environmental parameters such as room temperature, relative air humidity (RH), carbon dioxide (CO2), nitrogen dioxide (NO2), sulphur dioxide (SO2), ozone (O3), particulate matter (PM10), and health outcomes including prevalence, incidence and remission of SBS symptoms in junior high schools in Taiyuan, China. Totally 2134 pupils participated at baseline, and 1325 stayed in the same classrooms during the study period (2010–2012). The prevalence of mucosal symptoms, general symptoms and symptoms improved when away from school (school-related symptoms) was 22.7%, 20.4% and 39.2%, respectively, at baseline, and the prevalence increased during follow-up (P<0.001). At baseline, both indoor and outdoor SO2 were found positively associated with prevalence of school-related symptoms. Indoor O3 was shown to be positively associated with prevalence of skin symptoms. At follow-up, indoor PM10 was found to be positively associated with new onset of skin, mucosal and general symptoms. CO2 and RH were positively associated with new onset of mucosal, general and school-related symptoms. Outdoor SO2 was positively associated with new onset of skin symptoms, while outdoor NO2 was positively associated with new onset of skin, general and mucosal symptoms. Outdoor PM10 was found to be positively associated with new onset of skin, general and mucosal symptoms as well as school-related symptoms. In conclusion, symptoms as described for SBS were commonly found in school children in Taiyuan City, China, and increased during the two-year follow-up period. Environmental pollution, including PM10, SO2 and NO2, could increase the prevalence and incidence of SBS and decrease the remission rate. Moreover, parental asthma and allergy (heredity) and pollen or pet allergy (atopy) can be risk factors

  15. Emission measurements of alkenes, alkanes, SO2, and NO2 from stationary sources in Southeast Texas over a 5 year period using SOF and mobile DOAS

    NASA Astrophysics Data System (ADS)

    Johansson, John K. E.; Mellqvist, Johan; Samuelsson, Jerker; Offerle, Brian; Lefer, Barry; Rappenglück, Bernhard; Flynn, James; Yarwood, Greg

    2014-02-01

    A mobile platform for flux measurements of VOCs (alkanes and alkenes), SO2, and NO2 emissions using the Solar Occultation Flux (SOF) method and mobile differential optical absorption spectroscopy (DOAS) was used in four different studies to measure industrial emissions. The studies were carried out in several large conglomerates of oil refineries and petrochemical industries in Southeast and East Texas in 2006, 2009, 2011, and 2012. The measured alkane emissions from the Houston Ship Channel (HSC) have been fairly stable between 2006 and 2011, averaging about 11,500 kg/h, while the alkene emissions have shown greater variations. The ethene and propene emissions measured from the HSC were 1511 kg/h and 878 kg/h, respectively, in 2006, while dropping to roughly 600 kg/h for both species in 2009 and 2011. The results were compared to annual inventory emissions, showing that measured VOC emissions were typically 5-15 times higher, while for SO2 and NO2 the ratio was typically 0.5-2. AP-42 emission factors were used to estimate meteorological effects on alkane emissions from tanks, showing that these emissions may have been up to 35-45% higher during the studies than the annual average. A more focused study of alkene emissions from a petrochemical complex in Longview in 2012 identified two upset episodes, and the elevation of the total emissions during the measurement period due to the upsets was estimated to be approximately 20%. Both meteorological and upset effects were small compared to the factor of 5-15, suggesting that VOC emissions are systematically and substantially underestimated in current emission inventories.

  16. Inter-conversion of Chromium Species During Air Sampling: Effects of O3, NO2, SO2, Particle Matrices, Temperature and Humidity

    PubMed Central

    Huang, Lihui; Fan, Zhihua (Tina); Yu, Chang Ho; Hopke, Philip K.; Lioy, Paul J.; Buckley, Brian T.; Lin, Lin; Ma, Yingjun

    2013-01-01

    The inter-conversion between Cr(VI), a pulmonary carcinogen, and Cr(III), an essential human nutrient, poses challenges to the measurement of Cr(VI) in airborne particles. Chamber and field tests were conducted to identify the factors affecting Cr(VI)-Cr(III) inter-conversion in the basic filter medium under typical sampling conditions. In the chamber tests, isotopically enriched 53Cr(VI) and 50Cr(III) were spiked on diesel particulate matter (DPM) and secondary organic aerosol (SOA) that were pre-collected on a basic MCE filter. The filter samples were then exposed to clean air or the air containing SO2 (50 and 160 ppb), 100 ppb O3, or 150 ppb NO2 for 24 hours at 16.7 LPM flow rate at designated temperature (20 and 31°C) and RH (40% and 70%) conditions. Exposure to 160 ppb SO2 had the greatest effect on 53Cr(VI) reduction, with 53Cr(VI) recovery of 31.7 ± 15.8% (DPM) and 42.0 ± 7.9% (SOA). DPM and SOA matrix induced 53Cr(VI) reduction when exposed to clean air while reactive oxygen species in SOA could promote 50Cr(III) oxidation. Deliquescence when RH increased from 40% to 70% led to conversion of Cr(III) in SOA, whereas oxidized organics in DPM and SOA enhanced hygroscopicity and thus facilitated Cr(VI) reduction. Field tests showed seasonal variation of Cr(VI)-Cr(III) inter-conversion during sampling. Correction of the inter-conversion using USEPA method 6800 is recommended to improve accuracy of ambient Cr(VI) measurements. PMID:23550818

  17. Theoretical study of the NO, NO2, CO, SO2, and NH3 adsorptions on multi-diameter single-wall MoS2 nanotube

    NASA Astrophysics Data System (ADS)

    Cao, Rongfang; Zhou, Bo; Jia, Cuifang; Zhang, Xiaodong; Jiang, Zhenyi

    2016-02-01

    On the basis of first-principles calculations, the ability of a single-wall MoS2 nanotube to detect NO, NO2, CO, SO2, and NH3 gas molecules is studied. The most stable adsorption configurations, adsorption energies, and charge transfers are calculated. Among these gas molecules, the NO molecule has the biggest interaction with the MoS2 nanotube. The adsorption energy of NO on the nanotube is 129.3 meV, which is almost double compared to that for the monolayer (74.4 meV). The charge density difference calculation shows that all the molecules on the MoS2 nanotube act as electron acceptors except NH3. The charge transfer between NO and the nanotube is still one order of magnitude higher than that for the monolayer. Compared with the results for these molecules adsorbed on the MoS2 monolayer, the nanotube is more sensitive, especially for the NO molecule. Moreover, a comparative study of MoS2 nanotubes with different diameters (curvatures) indicates that the NO adsorption capability of the outer surface decreases on the increasing radius. It is predicted that the MoS2 nanotube with a smaller diameter should increase the stability and sensitivity of MoS2-based field-effect-transistor (FET) sensors.

  18. Measurements of industrial emissions of VOCs, NH3, NO2 and SO2 in Texas using the Solar Occultation Flux method and mobile DOAS

    NASA Astrophysics Data System (ADS)

    Mellqvist, J.; Samuelsson, J.; Rivera, C.; Lefer, B.; Patel, M.

    2007-12-01

    Solar Occultation Flux (SOF) measurements of olefines and alkanes have been conducted to pin-point and quantify the largest sources of olefines and alkanes in the vicinity of Houston and in south eastern Texas during September 2006. The SOF measurements were part of the extensive summer campaign TexAQS 2006, included in the Second Texas Air Quality Study (TexAQS II). The SOF technique is an optical method utilizing the absorption of direct solar infrared radiation in the 1.8-14 micrometer range for retrieval of total columns of various species such as ethylene, propylene, ammonia and alkanes. The instrument is carried on a mobile platform, making it possible to conduct transects of the emission plume downwind an industry, and thus integrate all the molecules of the plume cross section in real time. By multiplying with the plume wind speed, the total flux emerging from the source is obtained. Flux estimates with SOF were obtained for the large petrochemical and refining complexes around the Houston area. This was done in parallell with airborne plume studies by other parties. The primary research goal was to supply a data set for emission inventory comparisons and for input to models looking at the strong ozone production in Texas. The SOF measurements show that the hourly gas emissions from the Houston Ship channel area correspond to about 1 metric ton of ethylene, 1.5 tons of propylene, 12 tons of alkanes, 1/4 ton of NH3 and about 5 tons of SO2 and NO2. For the VOCs this is an order of magnitude or greater than reported VOC emissions in the 2004 inventory.

  19. Gas-Phase Ozonolysis of Cycloalkenes: Formation of Highly Oxidized RO2 Radicals and Their Reactions with NO, NO2, SO2, and Other RO2 Radicals.

    PubMed

    Berndt, Torsten; Richters, Stefanie; Kaethner, Ralf; Voigtländer, Jens; Stratmann, Frank; Sipilä, Mikko; Kulmala, Markku; Herrmann, Hartmut

    2015-10-15

    The gas-phase reaction of ozone with C5-C8 cycloalkenes has been investigated in a free-jet flow system at atmospheric pressure and a temperature of 297 ± 1 K. Highly oxidized RO2 radicals bearing at least 5 O atoms in the molecule and their subsequent reaction products were detected in most cases by means of nitrate-CI-APi-TOF mass spectrometry. Starting from a Criegee intermediate after splitting-off an OH-radical, the formation of these RO2 radicals can be explained via an autoxidation mechanism, meaning RO2 isomerization (ROO → QOOH) and subsequently O2 addition (QOOH + O2 → R'OO). Time-dependent RO2 radical measurements concerning the ozonolysis of cyclohexene indicate rate coefficients of the intramolecular H-shifts, ROO → QOOH, higher than 1 s(-1). The total molar yield of highly oxidized products (predominantly RO2 radicals) from C5-C8 cycloalkenes in air is 4.8-6.0% affected with a calibration uncertainty by a factor of about two. For the most abundant RO2 radical from cyclohexene ozonolysis, O,O-C6H7(OOH)2O2 ("O,O" stands for two O atoms arising from the ozone attack), the determination of the rate coefficients of the reaction with NO2, NO, and SO2 yielded (1.6 ± 0.5) × 10(-12), (3.4 ± 0.9) × 10(-11), and <10(-14) cm(3) molecule(-1) s(-1), respectively. The reaction of highly oxidized RO2 radicals with other peroxy radicals (R'O2) leads to detectable accretion products, RO2 + R'O2 → ROOR' + O2, which allows to acquire information on peroxy radicals not directly measurable with the nitrate ionization technique applied here. Additional experiments using acetate as the charger ion confirm conclusively the existence of highly oxidized RO2 radicals and closed-shell products. Other reaction products, detectable with this ionization technique, give a deeper insight in the reaction mechanism of cyclohexene ozonolysis. PMID:26392132

  20. 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.

  1. 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.

  2. Estimating Surface NO2 and SO2 Mixing Ratios from Fast-Response Total Column Observations and Potential Application to Geostationary Missions

    EPA Science Inventory

    Total-column nitrogen dioxide (NO2) data collected by a ground-based sun-tracking spectrometer system 21 (Pandora) and an photolytic-converter-based in-situ instrument collocated at NASA’s Langley Research Center in 22 Hampton, Virginia were analyzed to study the relationship bet...

  3. Polymer-gas reactions (air pollutants: NO2 and SO2) as function of pressure, UV light, temperature, and morphology: A survey

    NASA Technical Reports Server (NTRS)

    Jellinek, H. H. G.

    1972-01-01

    Reactions of various polymers, such as polystyrene and its stereo-specific isomers, butylrubber, nylon, etc., with nitrogen dioxide and sulfur-dioxide were studied over the past few years. More recently, work has been initiated on the influence of polymer morphology on degradation of polymers in presence of these gases, near UV radiation and oxygen. Unexpected effects have been observed during chain scission near room temperature. Thus, for instance, isotactic polystyrene of various crystallinities, as far as extent and type are concerned, show marked differences in their degradation characteristics. Thus, for instance, crystalline polymers show faster degradation than amorphous ones, which seems to be contrary to expectations. However, this phenomenon can be explained in quite a consistent manner. The importance of all these reactions in connection with air pollution is briefly discussed.

  4. Detecting CO, NO and NO2 gases by Boron-doped graphene nanoribbon molecular devices

    NASA Astrophysics Data System (ADS)

    Xie, Zhen; Zuo, Xi; Zhang, Guang-Ping; Li, Zong-Liang; Wang, Chuan-Kui

    2016-07-01

    Combining nonequilibrium Green's function method and density functional theory, an azulene-like dipole molecule sandwiched between two graphene nanoribbon (GNR) electrodes are explored to gas sensors. Both the pristine zigzag edged GNR and Boron-doped armchair-edged GNR are considered in this study. It shows that certain specific toxic molecules CO, NO and NO2 would adsorb on the doped Boron atoms of the GNR, resulting in a dramatic change in the current-voltage profile. Changes in the subbands of electrodes, induced by gas adsorption, are responsible for the variation of current. The devices are thus demonstrated to be sensitive nanosensors for these toxic gases.

  5. 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

  6. [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

  7. NH 4+, NO 3-, and SO 42- in roadside and rural size-resolved particles and transformation of NO 2/SO 2 to nanoparticle-bound NO 3-/SO 42-

    NASA Astrophysics Data System (ADS)

    Lin, Chih-Chung; Huang, Kuo-Lin; Chen, Shui-Jen; Liu, Shaw-Chen; Tsai, Jen-Hsiung; Lin, Yuan-Chung; Lin, Wen-Yinn

    This study investigates ammonium, nitrate, and sulfate (NH 4+, NO 3-, and SO 42-) in size-resolved particles (particularly nano (PM 0.01-0.056)/ultrafine (PM 0.01-0.1)) and NO x/SO 2 collected near a busy road and at a rural site. The average (mass) cumulative fraction of secondary inorganic aerosols (SO 42-+NO 3-+NH 4+) in nano or ultrafine particles at the roadside was found to be three to four times that at the rural site. The above three secondary inorganic aerosol species were present in similar cumulative fractions in particles of size 1-18 μm at both sites; however, dissimilar fractions were observed for Cl -, Na +, and K +. The nitrogen ratios (NRs: NR = NO 3--N/(NO 3--N + NO 2-N)), sulfur ratios (SRs: SR = SO 42--S/(SO 42--S + SO 2-S)), dNR/D P (derivative of NR with respect to D P (particle diameter)), and dSR/D P (derivative of SR with respect to D P) at the roadside were higher than those at the rural site for nano/ultrafine particles. At both sites (particularly the roadside), the nanoparticles had significantly higher dNR/D P and dSR/D P values than differently sized particles, implying that NO 3-/SO 42- (from NO 2/SO 2 transformation or NO 3-/SO 42- deposition) were present on these particles.

  8. 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

  9. Spatial and temporal variations in atmospheric VOCs, NO2, SO2, and O3 concentrations at a heavily industrialized region in Western Turkey, and assessment of the carcinogenic risk levels of benzene

    NASA Astrophysics Data System (ADS)

    Civan, Mihriban Yılmaz; Elbir, Tolga; Seyfioglu, Remzi; Kuntasal, Öznur Oğuz; Bayram, Abdurrahman; Doğan, Güray; Yurdakul, Sema; Andiç, Özgün; Müezzinoğlu, Aysen; Sofuoglu, Sait C.; Pekey, Hakan; Pekey, Beyhan; Bozlaker, Ayse; Odabasi, Mustafa; Tuncel, Gürdal

    2015-02-01

    Ambient concentrations of volatile organic compounds (VOCs), nitrogen dioxide (NO2), sulphur dioxide (SO2) and ground-level ozone (O3) were measured at 55 locations around a densely populated industrial zone, hosting a petrochemical complex (Petkim), a petroleum refinery (Tupras), ship-dismantling facilities, several iron and steel plants, and a gas-fired power plant. Five passive sampling campaigns were performed covering summer and winter seasons of 2005 and 2007. Elevated concentrations of VOCs, NO2 and SO2 around the refinery, petrochemical complex and roads indicated that industrial activities and vehicular emissions are the main sources of these pollutants in the region. Ozone concentrations were low at the industrial zone and settlement areas, but high in rural stations downwind from these sources due to NO distillation. The United States Environmental Protection Agency's positive matrix factorization receptor model (EPA PMF) was employed to apportion ambient concentrations of VOCs into six factors, which were associated with emissions sources. Traffic was found to be highest contributor to measured ∑VOCs concentrations, followed by the Petkim and Tupras. Median cancer risk due to benzene inhalation calculated using a Monte Carlo simulation was approximately 4 per-one-million population, which exceeded the U.S. EPA benchmark of 1 per one million. Petkim, Tupras and traffic emissions were the major sources of cancer risk due to benzene inhalation in the Aliaga airshed. Relative contributions of these two source groups changes significantly from one location to another, demonstrating the limitation of determining source contributions and calculating health risk using data from one or two permanent stations in an industrial area.

  10. The effect of anthropogenic activity on BTEX, NO2, SO2, and CO concentrations in urban air of the spa city of Sopot and medium-industrialized city of Tczew located in North Poland.

    PubMed

    Marć, Mariusz; Bielawska, Michalina; Simeonov, Vasil; Namieśnik, Jacek; Zabiegała, Bożena

    2016-05-01

    The major goal of the present study is to compare the air quality of two urban locations situated in Northern Poland - the spa City of Sopot and the medium-industrialized city of Tczew using chemometric methods. As a criterion for the assessment of atmospheric air quality, measurements of benzene, toluene, ethylbenzene and total xylenes were used (collected from atmospheric air using diffusion-type passive samplers) as well as measurements of inorganic compounds - CO, NO2 and SO2, which were subject to routine control and determined by means of automatic analysers. Studies related to determination of defined chemical compounds in the urban air in the monitored area were performed from January 2013 to December 2014. By interpreting the results obtained and using basic multivariate statistical tools (cluster analysis and principal components analysis), major sources of emissions of determined pollutants in the air in urbanized areas were defined. The study also shows the potential influence of the sea breeze on concentrations of chemical compounds in the atmospheric air in the spa city of Sopot. PMID:26990845

  11. Application of a long-path differential optical absorption spectrometer (LP-DOAS) on the measurements of NO(2), SO(2), O(3), and HNO(2) in Gwangju, Korea.

    PubMed

    Lee, Jeongsoon; Kim, Ki-Hyun; Kim, Young J; Lee, Jaihoon

    2008-03-01

    A differential optical absorption spectrometer (DOAS) technique has been applied to monitor airborne trace pollutants including NO(2), SO(2), O(3), and HNO(2) in the ultraviolet (UV) region (290-350 nm) over a 1.5 km beam path (two ways) during an intensive measurement campaign held at Gwangju, Korea (March 2002). Their mean mixing ratios (and standard deviations) were computed as 11.3 (8.8), 1.9 (1.7), 17.1 (19.3), and 0.5 (0.4)ppbv, respectively. As a means to evaluate the performance of the long-path DOAS (LP-DOAS) system with conventional point monitoring systems (PMS), correlation analysis was conducted between the two data sets. These data sets were then inspected to account for the influence of the environmental conditions on the correlation strength between the two systems, especially with respect to light level and wind speed. To facilitate the comparison, correlation analyses were conducted after dividing the data sets for those parameters into several classes. The strength of the correlations between DOAS and meteorological parameters was also examined to evaluate their effects on the DOAS performance. It was found that, among the four pollutant species, O(3) is the most sensitive to changes in meteorological conditions in relation with atmospheric mixing conditions. The overall results of our study indicate that open-path monitoring techniques can be used to effectively diagnose air quality and be substituted for the conventional point monitoring methods with the proper consideration of those parameters affecting the DOAS sensitivity (e.g., light level and wind speed). PMID:17335958

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. 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...

  4. 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.

  5. 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.

  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. 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

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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), ...

  14. 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...

  15. 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...

  16. 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.

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. 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

  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. MERCURY SPECIATION IN COMBUSTION SYSTEMS: STUDIES WITH SIMULATED FLUE GASES AND MODEL FLY ASHES

    EPA Science Inventory

    The paper gives results of a bench-scale study of the effects of flue gas and fly ash parameters on the oxidation of elemental mercury in simulated flue gases containing hydrogen chloride (HCl), nitric oxide (NO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and water vapor (H2O...

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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...

  14. 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...

  15. 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,...

  16. 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...

  17. Statistical persistence of air pollutants (O3,SO2,NO2 and PM10) in Mexico City

    NASA Astrophysics Data System (ADS)

    Meraz, M.; Rodriguez, E.; Femat, R.; Echeverria, J. C.; Alvarez-Ramirez, J.

    2015-06-01

    The rescaled range (R / S) analysis was used for analyzing the statistical persistence of air pollutants in Mexico City. The air-pollution time series consisted of hourly observations of ozone, nitrogen dioxide, sulfur dioxide and particulate matter obtained at the Mexico City downtown monitoring station during 1999-2014. The results showed that long-range persistence is not a uniform property over a wide range of time scales, from days to months. In fact, although the air pollutant concentrations exhibit an average persistent behavior, environmental (e.g., daily and yearly) and socio-economic (e.g., daily and weekly) cycles are reflected in the dependence of the persistence strength as quantified in terms of the Hurst exponent. It was also found that the Hurst exponent exhibits time variations, with the ozone and nitrate oxide concentrations presenting some regularity, such as annual cycles. The persistence dynamics of the pollutant concentrations increased during the rainy season and decreased during the dry season. The time and scale dependences of the persistence properties provide some insights in the mechanisms involved in the internal dynamics of the Mexico City atmosphere for accumulating and dissipating dangerous air pollutants. While in the short-term individual pollutants dynamics seems to be governed by specific mechanisms, in the long-term (for monthly and higher scales) meteorological and seasonal mechanisms involved in atmospheric recirculation seem to dominate the dynamics of all air pollutant concentrations.

  18. 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

  19. First Global Maps of Stratospheric and Tropospheric NO2 from OMI

    NASA Technical Reports Server (NTRS)

    Bucsela, Eric J.; Celarier, Edward A.; Wenig, Mark O.; Gleason, James F.; Veefkind, J. Pepijn

    2004-01-01

    The Ozone Monitoring Instrument (OMI) was launched successfully in July 2004, as one of four instruments on the EOS Aura satellite. OMI makes hyperspectral measurements that are used to retrieve column densities of critical trace gases, including formaldehyde, BrO, SO2 and NO2 . We present the first results from the OM1 operational NO2 algorithm and demonstrate its ability to retrieve the tropospheric and stratospheric components of NO2. The DOAS method is used to determine slant column densities, and initial air mass factors (AMFs) are used. to give initial estimates of the vertical column densities (VCDs). VCDs from up to 15 consecutive orbits are collected, and a spatial filtering technique is applied to extract the synoptic-scale features characteristic of the stratospheric, field. features to be evidence of tropospheric excess NO2 , and apply an AMF appropriate to polluted conditions, to obtain an improved retrieval of the NO2 total VCD. We describe the assumptions underlying the algorithm in detail, and show global maps of NO2 VCDs, based on the first operational data from OMI.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Effect of SO2 and Photolysis on Photooxidized Diesel Fuel Secondary Organic Aerosol Composition

    NASA Astrophysics Data System (ADS)

    MacMillan, A. C.; Blair, S. L.; Lin, P.; Laskin, A.; Laskin, J.; Nizkorodov, S.

    2014-12-01

    Diesel fuel (DSL) and sulfur dioxide (SO2) are important precursors to secondary organic aerosol (SOA) formation. DSL is often co-emitted with SO2 and NO2, thus it is important to understand the possible effects of SO2 on DSL SOA composition. Additionally, DSL SOA composition can be affected by photochemical aging processes such as photolysis. In this study, DSL SOA was first prepared under dry, high-NOx conditions with various concentrations of SO2 by photooxidation in a smog chamber. The SOA was then stripped of excess oxidants and gaseous organics with a denuder train and the resulting particles were photolyzed at various photolysis times in a quartz flow tube. The SOA composition, photochemical aging, properties, and mass concentration, before and after direct photolysis in the flow tube, were examined using several techniques. High-resolution mass spectrometry (HR-MS) was performed on DSL SOA samples to investigate the effect of SO2 on molecular level composition. SOA composition as a function of photolysis time was measured with an aerosol mass spectrometer (AMS). HR-MS results show that organosulfates are produced in DSL SOA. Both AMS and HR-MS results show that photolysis also has an effect on composition; though, this is more apparent in the HR-MS results than in the AMS results. In summary, both the presence of SO2 and solar radiation has an effect on DSL SOA composition.

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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 ...

  11. 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...

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. Sulfate Formation Enhanced by a Cocktail of High NOx, SO2, Particulate Matter, and Droplet pH during Haze-Fog Events in Megacities in China: An Observation-Based Modeling Investigation.

    PubMed

    Xue, Jian; Yuan, Zibing; Griffith, Stephen M; Yu, Xin; Lau, Alexis K H; Yu, Jian Zhen

    2016-07-19

    In recent years in a few Chinese megacities, fog events lasting one to a few days have been frequently associated with high levels of aerosol loading characterized by high sulfate (as high as 30 μg m(-3)), therefore termed as haze-fog events. The concomitant pollution characteristics include high gas-phase mixing ratios of SO2 (up to 71 ppbv) and NO2 (up to 69 ppbv), high aqueous phase pH (5-6), and smaller fog droplets (as low as 2 μm), resulting from intense emissions from fossil fuel combustion and construction activities supplying abundant Ca(2+). In this work, we use an observation-based model for secondary inorganic aerosols (OBM-SIA) to simulate sulfate formation pathways under conditions of haze-fog events encountered in Chinese megacities. The OBM analysis has identified, at a typical haze-fogwater pH of 5.6, the most important pathway to be oxidation of S(IV) by dissolved NO2, followed by the heterogeneous reaction of SO2 on the aerosol surface. The aqueous phase oxidation of S(IV) by H2O2 is a very minor formation pathway as a result of the high NOx conditions suppressing H2O2 formation. The model results indicate that the unique cocktail of high fogwater pH, high concentrations of NO2, SO2, and PM, and small fog droplets are capable of greatly enhancing sulfate formation. Such haze-fog conditions could lead to rapid sulfate production at night and subsequently high PM2.5 in the morning when the fog evaporates. Sulfate formation is simulated to be highly sensitive to fogwater pH, PM, and precursor gases NO2 and SO2. Such insights on major contributing factors imply that reduction of road dust and NOx emissions could lessen PM2.5 loadings in Chinese megacities during fog events. PMID:27331615

  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. Formation of HNO 2 on aerosol surfaces during foggy periods in the presence of NO and NO 2

    NASA Astrophysics Data System (ADS)

    Notholt, J.; Hjorth, J.; Raes, F.

    A commercial Differential Optical Absorption Spectrometer (DOAS), measuring trace gases absorbing in the u.v./vis region was used for obtaining information on aerosol parameters (e.g. total surface) based on the observed Mie scattering. This procedure allows simultaneous measurements of trace gas concentrations and aerosol parameters within the same air volume. A series of measurements of HNO 2, NO 2, NO, SO 2 and aerosol parameters was performed at Ispra in northern Italy. The observations show a rapid formation of gaseous HNO 2 during foggy episodes and give direct evidence of an important contribution of reactions on wet aerosols to the transformation of tropospheric NO x into HNO 2.

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. [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

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. 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...

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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 ...

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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...

  13. 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...

  14. 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...

  15. 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 ...

  16. 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/...

  17. 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...

  18. 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.

  19. 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...

  20. 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

  1. 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

  2. Kinetics of the reaction HO2 + NO2 + M yields HO2NO2 + M

    NASA Technical Reports Server (NTRS)

    Sander, S. P.; Peterson, M. E.

    1984-01-01

    The flash photolysis/ultraviolet absorption technique was used to measure the rate constants for the reaction HO2 + NO2 + M yields HO2NO2 + M over the pressure range 50-700 torr and temperature range 229-362 K using He, O2, and N2 as diluent gases. The data were fit to the expression derived by Troe (1979) and co-workers for describing the pressure and temperature dependence of reactions in the falloff region. By combining these data with recent measurements of the rate constant for HO2NO2 thermal decomposition values of 73.8 + or - 2 eu for the standard entropy and -12.6 + or - kcal/mol for the standard enthalpy of formation of HO2NO2 were obtained. A significant enhancement in the rate constant was observed when water vapor was added to the system.

  3. Light-Induced SO2 Photochemistry at the Mineral Dust Surface

    NASA Astrophysics Data System (ADS)

    Styler, S. A.; Doussin, J.; Formenti, P.; Donaldson, D.

    2013-12-01

    The uptake of SO2 by mineral dust is believed to proceed first by formation of surface-bound sulfite, which can subsequently be oxidized to sulfate not only by co-sorbed O3 and NO2 but also by photooxidants such as Fe and Ti present within the dust itself. In the first phase of this study, we investigated the effect of light upon SO2 uptake by Fe2O3, TiO2, illite, feldspar, and mineral dust samples obtained from Niger, Tunisia, and China. We determined the initial uptake coefficient of SO2 at the surface of dust samples under both light and dark conditions using a photochemical Knudsen cell, and then measured the relative quantities of sulfite and sulfate formed at the surface of these films using ion chromatography. In the second phase of this study, which was performed in the CESAM atmospheric chamber, we explored the possibility that light-induced production of surface-sorbed sulfate might result in enhanced dust hygroscopicity by measuring changes in dust particle size distribution as a function of exposure to SO2 and light under a range of relative humidity conditions.

  4. Quenching of the fluorescence of NO2

    NASA Technical Reports Server (NTRS)

    Braslavsky, S.; Heicklen, J.

    1972-01-01

    The fluorescence yield of NO2 was monitored at 25 C with incident wavelengths of 4047, 4358, and 4800A at fluorescence wavelengths of 4860, 5577, and 6300A. The NO2 pressure was varied between 0.004 and 0.080 torr. Measurements were taken both in the absence of foreign gases and in the presence of up to 30 torr. He, N2, and O2 at each NO2 pressure. In the absence of foreign gases, the self quenching follows a Stern-Volmer quenching mechanism, but foreign-gas quenching shows marked deviations from this mechanism. Both from lifetime and kinetic considerations, it is argued that the electronic state formed by absorption of the radiation cannot be the emitting state. Emission occurs from several vibrational levels of the emitting state, the various vibrational levels being formed by collisional cascade reactions. The appropriate quenching rate constant ratios were measured and tabulated. Even the two electronic state mechanism is insufficient to explain all the observations.

  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. 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...

  7. 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...

  8. 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...

  9. 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...

  10. Observations of atmospheric trace gases by MAX-DOAS in the coastal boundary layer over Jiaozhou Bay

    NASA Astrophysics Data System (ADS)

    Li, Xianxin; Wang, Zhangjun; Meng, Xiangqian; Zhou, Haijin; Du, Libin; Qu, Junle; Chen, Chao; An, Quan; Wu, Chengxuan; Wang, Xiufen

    2014-11-01

    Atmospheric trace gases exist in the atmosphere of the earth rarely. But the atmospheric trace gases play an important role in the global atmospheric environment and ecological balance by participating in the global atmospheric cycle. And many environmental problems are caused by the atmospheric trace gases such as photochemical smog, acid rain, greenhouse effect, ozone depletion, etc. So observations of atmospheric trace gases become very important. Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) developed recently is a kind of promising passive remote sensing technology which can utilize scattered sunlight received from multiple viewing directions to derive vertical column density of lower tropospheric trace gases like ozone, sulfur dioxide and nitrogen dioxide. It has advantages of simple structure, stable running, passive remote sensing and real-time online monitoring automatically. A MAX-DOAS has been developed at Shandong Academy of Sciences Institute of Oceanographic Instrumentation (SDIOI) for remote measurements of lower tropospheric trace gases (NO2, SO2, and O3). In this paper, we mainly introduce the stucture of the instrument, calibration and results. Detailed performance analysis and calibration of the instrument were made at Qingdao. We present the results of NO2, SO2 and O3 vertical column density measured in the coastal boundary layer over Jiaozhou Bay. The diurnal variation and the daily average value comparison of vertical column density during a long-trem observation are presented. The vertical column density of NO2 and SO2 measured during Qingdao oil pipeline explosion on November 22, 2013 by MAX-DOAS is also presented. The vertical column density of NO2 reached to a high value after the explosion. Finally, the following job and the outlook for future possible improvements are given. Experimental calibration and results show that the developed MAX-DOAS system is reliable and credible.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Pulsed sub-microsecond dielectric barrier discharge treatment of simulated glass manufacturing industry flue gas: removal of SO2 and NOx

    NASA Astrophysics Data System (ADS)

    Khacef, A.; Cormier, J. M.

    2006-03-01

    Experiments were carried out to investigate the removal of SO2 and NOx from simulated glass manufacturing industry flue gas containing O2, N2, NO, NO2, CO2, SO2 and H2O using a sub-microsecond pulsed dielectric barrier discharge (DBD) at atmospheric pressure. Removal efficiencies of SO2 and NOx (NO+NO2) were achieved as a function of gas temperature for two specific energies and two initial NO, NO2 and SO2 concentrations. The higher SO2 and NOx removal efficiencies were achieved in a gas stream containing 163 ppm of SO2, 523 ppm of NO, 49 ppm of NO2, 14% of CO2, 8% of O2, 16% of H2O and N2 as balance. The experimental results were evaluated using the energy cost or W-value (eV/molecule removed). About 100% of SO2 and 36% of NOx were removed at a gas temperature of 100 °C with an energy cost of about 45 eV/molecule removed and 36 eV/molecule removed, respectively. These results indicate that DBD plasmas have the potential to remove SO2 and NOx from gas streams without additives.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. An Examination of NOx, SO2, and CO Emissions from East Texas Power Plants

    NASA Astrophysics Data System (ADS)

    Peischl, J.; Ryerson, T. B.; Holloway, J. S.; Aikin, K. C.; Frost, G. J.; Fehsenfeld, F. C.

    2007-12-01

    Emissions from several East Texas power plants were measured from aircraft during the 2000 and 2006 Texas Air Quality Studies. One-second measurements were made of NOy, SO2, CO, and CO2 during these flights. NOy (total reactive nitrogen) is used as a proxy for power plant NOx (NO + NO2) emissions to account for any reactions that may have occurred between emission and measurement. Emission ratios of NOy, SO2, and CO to CO2 were calculated from the closest down-wind transects of plumes from seven power plants. Emission ratios were also calculated with hourly data from the Continuous Emission Monitoring System (CEMS). The aircraft data show substantial (25-80 percent) reductions in NOx emissions from four of the power plants between 2000 and 2006, whereas SO2 and CO emissions from all plants appear to be largely unchanged during this time. Emission ratios calculated from the aircraft and from hourly CEMS data in 2006 agree to within an average of approximately 10 percent, which suggests the CEMS data are a fair representation of power plant emissions.

  6. Studies on potential emission of hazardous gases due to uncontrolled open-air burning of waste vehicle tyres and their possible impacts on the environment

    NASA Astrophysics Data System (ADS)

    Shakya, Pawan R.; Shrestha, Pratima; Tamrakar, Chirika S.; Bhattarai, Pradeep K.

    Uncontrolled open-air burning of waste vehicle tyres causing environmental pollution has become a popular practice in Nepal despite official ban considering the environment and public health hazards. In this study, an experimental model was set up in a laboratory scale in an attempt to understand the potential emission of hazardous gases such as CO, SO 2 and NO 2 due to such activities in Kathmandu Valley and their possible impacts on the environment. For this purpose, four types of tyre were collected representing two from passenger car and two from motorbike category. The emission level of CO in the tyre smoke was measured with a CO gas detector tube while SO 2 and NO 2 were determined by UV-visible spectrophotometer. Among the three types of the gases analyzed, SO 2 was emitted in significantly high levels by all the representative tyre samples. The emission levels of CO, SO 2 and NO 2 ranged from 21to 49, 102to 820 and 3to 9 μg g -1, respectively. Results revealed that the emission levels also varied with the tyre types and qualities. The potential emission of the hazardous gases per representative scrap tyre mass was also estimated. Results indicate that the gaseous pollutants due to the tyre fires could make a significant contribution for deterioration of the environmental condition of the Valley or elsewhere.

  7. AOTF-based NO2 camera, results from the AROMAT-2 campaign

    NASA Astrophysics Data System (ADS)

    Dekemper, Emmanuel; Fussen, Didier; Vanhamel, Jurgen; Van Opstal, Bert; Maes, Jeroen; Merlaud, Alexis; Stebel, Kerstin; Schuettemeyer, Dirk

    2016-04-01

    A hyperspectral imager based on an acousto-optical tunable filter (AOTF) has been developed in the frame of the ALTIUS mission (atmospheric limb tracker for the investigation of the upcoming stratosphere). ALTIUS is a three-channel (UV, VIS, NIR) space-borne limb sounder aiming at the retrieval of concentration profiles of important trace species (O3, NO2, aerosols and more) with a good vertical resolution. An optical breadboard was built from the VIS channel concept and is now serving as a ground-based remote sensing instrument. Its good spectral resolution (0.6nm) coupled to its natural imaging capabilities (6° square field of view sampled by a 512x512 pixels sensor) make it suitable for the measurement of 2D fields of NO2, similarly to what is nowadays achieved with SO2 cameras. Our NO2 camera was one of the instruments that took part to the second Airborne ROmanian Measurements of Aerosols and Trace gases (AROMAT-2) campaign in August 2015. It was pointed to the smokestacks of the coal and oil burning power plant of Turceni (Romania) in order to image the exhausted field of NO2 and derive slant columns and instantaneous emission fluxes. The ultimate goal of the AROMAT campaigns is to prepare the validation of TROPOMI onboard Sentinel-5P. We will briefly describe the instrumental concept of the NO2 camera, its heritage from the ALTIUS mission, and its advantages compared to previous attempts of reaching the same goal. Key results obtained with the camera during the AROMAT-2 campaign will be presented and further improvements will be discussed.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. Variation of stratospheric NO2 during the solar eclipse

    NASA Technical Reports Server (NTRS)

    Elansky, Nikolay F.; Elokhov, Alexander S.

    1994-01-01

    The numerical modeling of the changes of the concentration of trace gases in the atmosphere during the eclipse shows that the NO2 total content in the vertical column increases approximately by 80 percent. The first observations of the NO2 total content during the eclipse of 1981 have given 60 plus or minus 20 percent. In the observations of 1990 the more precise methods and instruments for stratospheric NO2 measurements were used. The surface ozone, NO, and NO2 concentrations were under control. The results of the observations give the increasing of the stratospheric NO2 during the eclipse by 55 plus or minus 6 percent. The maximum increasing of the NO2 content is observed at the moment of the maximum phase.

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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

  19. Atmospheric trace gases monitoring by UV-vis spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Xie, Pinhua; Li, Ang; Wu, Fengcheng; Qin, Min; Hu, Rezhi; Xu, Jin; Si, Fuqi; Liu, Jianguo; Liu, Wenqing

    2016-04-01

    Due to rapidly economic development, air pollution has become an important issue in China. Phenomena such as regional haze in winter and high O3 concentration in summer are strongly related to increasing trace species. For better understanding the air pollution formation, it is necessary to know spatial and temporal distribution of trace species in the atmosphere. UV-vis spectroscopic techniques are of great advantages for trace species monitoring to meet several requirements, e.g. versatility, high sensitivity, good temporal resolution and field applicability. We have studied and developed various trace gases monitoring techniques and instruments based on UV-vis spectroscopic technique for in-situ measurements and remote sensing, e.g. LP-DOAS, IBBCEAS, CRDS, MAX-DOAS and mobile DOAS for NO2, SO2, HCHO, HONO, NO3, and N2O5 etc. The principle, instrumentation and inversion algorithm are presented. As typical applications of these techniques, investigation of the evolution of HONO and NO3 radicals over Beijing area, measurements of regional pollution in NCP and YRD are discussed in the aspects of HONO and nocturnal NO3 radical characteristics, trace gases (NO2, SO2 etc.) temporal and spatial distribution, pollution transport pathway, emission sources.

  20. Pentafluoronitrosulfane, SF5NO2.

    PubMed

    Lu, Norman; Thrasher, Joseph S; von Ahsen, Stefan; Willner, Helge; Hnyk, Drahomir; Oberhammer, Heinz

    2006-02-20

    The synthesis of pentafluoronitrosulfane, SF5NO2, is accomplished either by reacting N(SF5)3 with NO2 or by the photolysis of a SF5Br/NO2 mixture using diazo lamps. The product is purified by treatment with CsF and repeated trap-to-trap condensation. The solid compound melts at -78 degrees C, and the extrapolated boiling point is 9 degrees C. SF5NO2 is characterized by 19F, 15N NMR, IR, Raman, and UV spectroscopy as well as by mass spectrometry. The molecular structure of SF5NO2 is determined by gas electron diffraction. The molecule possesses C2v symmetry with the NO2 group staggering the equatorial S-F bonds and an extremely long 1.903(7) Angstroms S-N bond. Calculated bond enthalpies depend strongly on the computational method: 159 (MP2/6-311G++(3df)) and 87 kJ mol(-1) (B3LYP/6-311++G(3df)). The experimental geometry and vibrational spectrum are reproduced reasonably well by quantum chemical calculations. PMID:16471994

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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).

  6. Production of NO2 from Photolysis of Peroxyacetyl Nitrate

    NASA Technical Reports Server (NTRS)

    Mazely, Troy L.; Friedl, Randall R.; Sander, Stanley P.

    1965-01-01

    Peroxyacetyl nitrate (PAN) vapor was photolyzed at 248 nm, and the NO2 photoproduct was detected by laser-induced fluorescence. The quantum yield for the production of NO2 from PAN photolysis was determined by comparison to HNO3 photolysis data taken under identical experimental conditions. The average of data collected over a range of total pressures, precursor concentrations, and buffer gases was 0.83 +/- 0.09 for the NO2 quantum yield, where the statistical uncertainty is 2 standard deviations.

  7. 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.

  8. Mass transfer in the absorption of SO2 and NO(x) using aqueous euchlorine scrubbing solution.

    PubMed

    Deshwal, Bal-Raj; Lee, Hyung-Keun

    2009-01-01

    Attempts have been made to generate euchlorine gas by chlorate-chloride process and to utilize it further to clean up SO2 and NO(x) from the flue gas in a lab scale bubbling reactor. Preliminary experiments were carried out to determine the gas and liquid phase mass transfer coefficients and their correlation equations have been established. Simultaneous removal of SO2 and NO(x) from the simulated flue gas using aqueous euchlorine scrubbing solution has been investigated. Euchlorine oxidized NO into NO2 completely and the later subsequently absorbed into the scrubbing solution in the form of nitrate. SO2 removal efficiency around 100% and NO(x) removal efficiency around 72% were achieved under optimal conditions. Mass balance has been confirmed by analyzing the sulfate, nitrate, euchlorine and chloride ion using ion chromatograph/auto-titrator and comparing it with their corresponding calculated values. PMID:19402415

  9. 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

  10. 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.

  11. 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...

  12. 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...

  13. 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...

  14. Global Reactive Gases in the MACC project

    NASA Astrophysics Data System (ADS)

    Schultz, M. G.

    2012-04-01

    In preparation for the planned atmospheric service component of the European Global Monitoring for Environment and Security (GMES) initiative, the EU FP7 project Monitoring of Atmospheric Composition and Climate (MACC) developed a preoperational data assimilation and modelling system for monitoring and forecasting of reactive gases, greenhouse gases and aerosols. The project is coordinated by the European Centre for Medium-Range Weather Forecast (ECMWF) and the system is built on ECMWF's Integrated Forecasting System (IFS) which has been coupled to the chemistry transport models MOZART-3 and TM5. In order to provide daily forecasts of up to 96 hours for global reactive gases, various satellite retrieval products for ozone (total column and profile data), CO, NO2, CH2O and SO2 are either actively assimilated or passively monitored. The MACC system is routinely evaluated with in-situ data from ground-based stations, ozone sondes and aircraft measurements, and with independent satellite retrievals. Global MACC reactive gases forecasts are used in the planning and analysis of large international field campaigns and to provide dynamical chemical boundary conditions to regional air quality models worldwide. Several case studies of outstanding air pollution events have been performed, and they demonstrate the strengths and weaknesses of chemical data assimilation based on current satellite data products. Besides the regular analyses and forecasts of the tropospheric chemical composition, the MACC system is also used to monitor the evolution of stratospheric ozone. A comprehensive reanalysis simulation from 2003 to 2010 provides new insights into the interannual variability of the atmospheric chemical composition.

  15. 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.

  16. Selective Improvement of NO2 Gas Sensing Behavior in SnO2 Nanowires by Ion-Beam Irradiation.

    PubMed

    Kwon, Yong Jung; Kang, Sung Yong; Wu, Ping; Peng, Yuan; Kim, Sang Sub; Kim, Hyoun Woo

    2016-06-01

    We irradiated SnO2 nanowires with He ions (45 MeV) with different ion fluences. Structure and morphology of the SnO2 nanowires did not undergo noticeable changes upon ion-beam irradiation. Chemical equilibrium in SnO2/gas systems was calculated from thermodynamic principles, which were used to study the sensing selectivity of the tested gases, demonstrating the selective sensitivity of the SnO2 surface to NO2 gas. Being different from other gases, including H2, ethanol, acetone, SO2, and NH3, the sensor response to NO2 gas significantly increases as the ion fluence increases, showing a maximum under an ion fluence of 1 × 10(16) ions/cm(2). Photoluminescence analysis shows that the relative intensity of the peak at 2.1 eV to the peak at 2.5 eV increases upon ion-beam irradiation, suggesting that structural defects and/or tin interstitials have been generated. X-ray photoelectron spectroscopy indicated that the ionic ratio of Sn(2+/)Sn(4+) increases by the ion-beam irradiation, supporting the formation of surface Sn interstitials. Using thermodynamic calculations, we explained the observed selective sensing behavior. A molecular level model was also established for the adsorption of NO2 on ion-irradiated SnO2 (110) surfaces. We propose that the adsorption of NO2-related species is considerably enhanced by the generation of surface defects that are comprised of Sn interstitials. PMID:27167241

  17. 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...

  18. 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)...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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,...

  5. 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...

  6. 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...

  7. 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...

  8. 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,...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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,...

  10. 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...

  11. 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,...

  12. 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,...

  13. 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...

  14. 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,...

  15. 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...

  16. 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)...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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)...

  2. 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...

  3. 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)...

  4. 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)...

  5. 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...

  6. 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...

  7. 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...

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. Simultaneous absorption of NOx and SO2 from flue gas with pyrolusite slurry combined with gas-phase oxidation of NO using ozone.

    PubMed

    Sun, Wei-yi; Ding, Sang-lan; Zeng, Shan-shan; Su, Shi-jun; Jiang, Wen-ju

    2011-08-15

    NO was oxidized into NO(2) first by injecting ozone into flue gas stream, and then NO(2) was absorbed from flue gas simultaneously with SO(2) by pyrolusite slurry. Reaction mechanism and products during the absorption process were discussed in the followings. Effects of concentrations of injected ozone, inlet NO, pyrolusite and reaction temperature on NO(x)/SO(2) removal efficiency and Mn extraction rate were also investigated. The results showed that ozone could oxidize NO to NO(2) with selectivity and high efficiency, furthermore, MnO(2) in pyrolusite slurry could oxidize SO(2) and NO(2) into MnSO(4) and Mn(NO(3))(2) in liquid phase, respectively. Temperature and concentrations of injected ozone and inlet NO had little impact on both SO(2) removal efficiency and Mn extraction rate. Specifically, Mn extraction rate remained steady at around 85% when SO(2) removal efficiency dropped to 90%. NO(x) removal efficiency increased with the increasing of ozone concentration, inlet NO concentration and pyrolusite concentration, however, it remained stable when reaction temperature increased from 20°C to 40°C and decreased when the flue gas temperature exceeded 40°C. NO(x) removal efficiency reached 82% when inlet NO at 750 ppm, injected ozone at 900 ppm, concentration of pyrolusite at 500 g/L and temperature at 25°C. PMID:21620564

  13. [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

  14. A review of available LC/50/ data. [on toxic gases encountered in fires

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.

    1977-01-01

    Several gaseous products of pyrolysis and combustion have been evaluated for LC/50/, defined as the concentration of toxic gas in the atmosphere being inhaled by test animals that will produce death in 50% of the animals within a given time period. The products tested included CO, HCl, HF, HCN, NO2, and SO2. It was found that HCN and NO2 were consistently the most toxic of the gases reviewed, and that mice were more susceptible than rats to HCl and HF, although less susceptible than rats to NO2. Extrapolation of LC/50/ data to humans indicates that metabolic rate may be a valid basis for extrapolation when the toxicity mechanism is interference with oxygen transport and utilization, or pulmonary edema, but not when it is irritation and damage to the upper respiratory tract.

  15. Potential Impacts of two SO2 oxidation pathways on regional sulfate concentrations: acqueous-hase oxidation by NO2 and gas-phase oxidation by Stabilized Criegee Intermediates

    EPA Science Inventory

    We examine the potential impacts of two additional sulfate production pathways using the Community Multiscale Air Quality modeling system. First we evaluate the impact of the aqueous-phase oxidation of S(IV) by nitrogen dioxide using two published rate constants, differing by 1-2...

  16. 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...

  17. 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

  18. 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.

  19. 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

  20. An air quality management system as a tool for establishing a SO 2- and NOx-policy

    NASA Astrophysics Data System (ADS)

    Bovenkerk, M.; Builtjes, P. J. H.; Zwerver, S.

    A description is given of the development and use of an Air Quality Management System (AQMS) directed to the support of policy decisions made with respect to the conservation and improvement of clean air in the Netherlands. The AQMS consists of three separate modules oriented to economy, transmission and impact assessment. Application of the AQMS to SO 2 has led to the construction of an environmental decision scheme, in which maximum acceptable emission levels are given as a function of the primary and secondary SO 2-air quality standard, the S import-export balance and acidification. Together with information on the socio-economic impacts and the energy options this formed the basis for the political decision to limit future SO 2-emissions in the Netherlands to a value not higher than 500 × 10 6 kg y -1, in fact to establish a ceiling value for the emissions of SO 2. For NOx the AQMS is still under development, so at the moment it is not possible to formulate a complete NOx-environmental decision scheme. Up till now the emphasis has been on the development of the transmission module of the AQMS for NOx, i.e. the impact of domestic and foreign emissions. The results of this module are presented in the paper. The (partly preliminary) results of the AQMS-calculations point out the importance of long-range transport of NOx and photochemical precursors and products for the countrywide NO 2-pattern. The results emphasize the need for the abatement of NOx [and especially hydrocarbons (HC)] on a European scale. Also abatement of automobile exhaust is needed in order to prevent violation of the NO 2-standard at sites with high circulation of traffic.

  1. 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

  2. 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

  3. 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...

  4. Precursor gases of aerosols in the Mount St. Helens eruption plumes at stratospheric altitudes

    NASA Technical Reports Server (NTRS)

    Inn, E. C. Y.; Vedder, J. F.; Condon, E. P.; Ohara, D.

    1982-01-01

    Nineteen stratospheric samples from the eruption plumes of Mount St. Helens were collected in five flight experiments. The plume samples were collected at various altitudes from 13.1 to 20.7 km by using the Ames cryogenic sampling system on board the NASA U-2 aircraft. The enriched, cryogenically collected samples were analyzed by chromatography. The concentrations of aerosols precursor gases (OCS, SO2, and CS2), CH3Cl, N2O, CF2Cl2, and CFCl3 were measured by gas chromatography. Large enhancement of the mixing ratio of SO2 and moderate enhancement of CS2 and OCS were found in the plume samples compared with similar measurement under pre-volcanic conditions. A fast decay rate of the SO2 mixing ratio in the plume was observed. Measurement of Cl(-), SO2(2-), and NO3(-) by ion chromatography was also carried out on water solutions prepared from the plume samples. The results obtained with this technique imply large mixing ratios of HCl, (NO + NO2 + HNO3), and SO2, in which these constituents are the respective sources of the anions. Measurement of the Rn222 concentration in the plume was made. Other stratospheric constituents in the plume samples, such as H2O, CO2, CH4, and CO, were also observed.

  5. 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

  6. 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....

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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....

  12. 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....

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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 ...

  18. 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).

  19. 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.

  20. 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

  1. 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 ...

  2. Hot exhaust gases with passive FTIR emission spectroscopy

    NASA Astrophysics Data System (ADS)

    Heland, Joerg; Schaefer, Klaus; Haus, Rainer

    1998-12-01

    Passive FTIR emission spectroscopy using a commercial medium resolution instrument with a telescope has been applied to analyze the hot exhaust gases of various combustion sources, such as industrial and building smoke stacks, aircraft engines, flares, and forest fires. To interpret the remotely measured spectra a multi-layer, line-by-line spectra retrieval software using the molecular spectral databases HITRAN and HITEMP has been developed, validated and successfully used to determine the exhaust gas temperatures and the concentrations of CO2, H2O, CO, N2O, CH4, NO, NO2, SO2, and HCl for different combustion conditions of the sources. In this paper the feasibility and the setup of passive IR measurements, the basic theory of radiative transfer and special features of the commercially available spectra analysis code are described. In addition, the results of the different measurement applications are summarized.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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).

  8. 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

  9. 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.

  10. A NOx and SO2 gas analyzer using deep-UV and violet light-emitting diodes for continuous emissions monitoring systems

    NASA Astrophysics Data System (ADS)

    Higashi, Ryoichi; Taniguchi, Yu; Akao, Kozo; Koizumi, Kazuhiro; Hirayama, Noritomo; Nakano, Yoshiaki

    2014-02-01

    A nitrogen oxides (NOx) and sulfur dioxide (SO2) gas analyzer using deep ultraviolet (DUV) and violet light- emitting diodes (LEDs) is developed. The LEDs with wavelengths of 280 nm and 400 nm were alternately turned on to detect SO2 and nitrogen dioxide (NO2) absorption. Nitric oxide (NO) was converted to NO2 with an ozonizer. In order to reduce water interference caused by water adsorption onto an inner surface of a gas ow cell, collimating optics reducing re ected lights were designed. As a result, less than 1% by full scale (%F.S.) of uctuation, 2%F.S. of drift and 0.5%F.S. of water interference were achieved in 0-50 ppm concentration range. Conversion efficiency from NO to NO2 was over 95%.

  11. 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

  12. 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

  13. Simultaneous SO2 and NO removal from flue gas based on TiO2 photocatalytic oxidation.

    PubMed

    Zhao, Yi; Han, Jing; Shao, Yuan; Feng, Yana

    2009-12-14

    A new approach to the simultaneous removal of SO2 and NO from flue gas, by TiO2 photocatalysis based on UV irradiation technology, is presented. Experiments on the simultaneous desulphurization and denitrification were carried out using this photocatalyst in a self-designed photocatalytic reactor. Under the optimal experimental conditions, a removal efficiency of 98% for SO2 and 50% for NO was achieved. Scanning electron microscopy, transmission electron microscopy and X-ray energy spectrometry were used to observe the surface characteristics of the TiO2 photocatalyst. It was found that the surface of the quartz sand carrier was covered with Ti, on which the Si content of the quartz sand carrier was similar to the Ti content, indicating that the quartz sand supported the TiO2 membrane well. Based on the results of X-ray photoelectron spectroscopy (XPS) and chemical analysis of the resulting products, the SO2 and NO removal mechanisms were revealed. Sulphate was the main desulphurization product and nitrite was the main denitrification product. In the removal reaction, NO was rapidly oxidized to NO2 and absorbed in the chemical reaction. PMID:20184000

  14. Ground-based imaging differential optical absorption spectroscopy of atmospheric gases.

    PubMed

    Lohberger, Falko; Hönninger, Gerd; Platt, Ulrich

    2004-08-20

    We describe a compact remote-sensing instrument that permits spatially resolved mapping of atmospheric trace gases by passive differential optical absorption spectroscopy (DOAS) and present our first applications of imaging of the nitrogen dioxide contents of the exhaust plumes of two industrial emitters. DOAS permits the identification and quantification of various gases, e.g., NO2, SO2, and CH2O, from their specific narrowband (differential) absorption structures with high selectivity and sensitivity. With scattered sunlight as the light source, DOAS is used with an imaging spectrometer that is simultaneously acquiring spectral information on the incident light in one spatial dimension (column). The second spatial dimension is scanned by a moving mirror. PMID:15352396

  15. DFT investigation on molecular structure of zirconia nanoparticle and its adsorption structures with elementary gases

    NASA Astrophysics Data System (ADS)

    Kaewruksa, Benjawan; Vchirawongkwin, Viwat; Ruangpornvisuti, Vithaya

    2016-03-01

    The geometry optimizations of zirconia nanoparticle (ZrO2-NP), represented by the high symmetric (ZrO2)12 cluster and its adsorption configurations with diatomic (H2, N2, O2, CO and NO), triatomic (CO2, N2O, NO2, H2O, SO2 and H2S) and polyatomic (C2H2, C2H4, CH4 and NH3) gases were carried out using density functional theory method. Adsorption energies of all relevant gases on the ZrO2-NP obtained by the B3LYP and M06-2X methods are reported. Two types of adsorption sites on the ZrO2-NP, the planar and the v-shaped sites of Zr centers which adsorption strength of the former is higher than the later, were found. The zirconia nanoparticle applied for detecting oxygen molecule via its conductivity measurement could be recommended.

  16. 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

  17. 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

  18. 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).

  19. 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

  20. Endohedral metallofullerenes, M@C60 (M = Ca, Na, Sr): selective adsorption and sensing of open-shell NOx gases.

    PubMed

    Tawfik, Sherif Abdulkader; Cui, X Y; Ringer, S P; Stampfl, C

    2016-08-21

    Based on density-functional theory and non-equilibrium Green's function calculations, we demonstrate that endohedral metallofullerenes (EMFs) are reactive to open-shell gases, and therefore have the potential application as selective open-shell gas sensors. The adsorption of eight gas species (CO, H2O, H2S, NO2, NO, SO2, O2 and NH3) on three EMFs (M@C60, M = Ca, Na and Sr) shows that the adsorption energies of the EMFs towards NO2 and NO are significantly higher than the closed-shell species. Moreover, the high selectivity appears relatively insensitive to the inserted metal atoms. The calculated current-voltage characteristics of gold-M@C60-gold structures (M = Ca, Na) show that the adsorption of NO2 leads to significant change in conductivity, suggesting a potential application as an EMF gas resistive sensing device. PMID:27426253

  1. 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.

  2. [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

  3. 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

  4. 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).

  5. 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

  6. 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).

  7. 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

  8. 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.

  9. Photoenhanced NO2 loss on simulated urban grime

    NASA Astrophysics Data System (ADS)

    Ammar, R.; Monge, M. E.; D'Anna, B.; George, C.

    2010-12-01

    Solid and liquid particles provide surfaces for heterogeneous reaction, influencing the abundance and distribution of trace gases affecting air quality in urban environments. However, condensed matter can even be found on films coating urban surfaces (such as roads and buildings), also called “urban grime”. The present study focuses on the heterogeneous reaction between gaseous NO2 and solid films used as a proxy of “urban grime”. These reactions were investigated under simulated atmospheric conditions with respect to relative humidity, NO2 concentration and irradiation using a coated wall flow tube reactor. This proxy was tested by the mixture of organic compounds (pyrene), inorganic compounds (potassium nitrate) and Metals (iron oxide). The geometric steady-state uptake coefficients (γgeo) obtained when pyrene/KNO3 films are exposed to 50 ppbv of NO2 ranged from 1.12×10-7 in the dark to 2.67×10-6 under near-UV irradiation (300-420 nm) and decreased with increasing NO2 concentration in the range 30-120 ppbv. The NO2 removal is linearly dependent on the light intensity with release of gas-phase NO and HONO, which rapidly photodissociates to form OH in the troposphere. The analysis of this film by IC and GC-MS showed the formation of nitrite ion and traces of 1-nitropyrene. A light-induced reaction mechanism is proposed for this system. The results discussed here suggest that urban “grime” on windows and buildings containing PAHs may be a key player in urban air pollution. The presence of iron oxide in the film is currently being treated in order to know its effect and reactivity towards organic compounds and gas-phase NO2 under irradiation and to see how can real urban film surfaces be photoenhanced in the presence of gas-phase NO2.

  10. Screening of inorganic gases released from firework-rockets by a gas chromatography/whistle-accelerometer method.

    PubMed

    Chen, Kuan-Fu; Wu, Hui-Hsin; Lin, Chien-Hung; Lin, Cheng-Huang

    2013-08-30

    The use of an accelerometer for detecting inorganic gases in gas chromatography (GC) is described. A milli-whistle was connected to the outlet of the GC capillary and was used instead of a classical GC detector. When the GC carrier gases and the sample gases pass through the milli-whistle, a sound is produced, leading to vibrational changes, which can be recorded using an accelerometer. Inorganic gases, including SO2, N2 and CO2, which are released from traditional Chinese firework-rockets at relatively high levels as the result of burning the propellant and explosive material inside could be rapidly determined using the GC/whistle-accelerometer system. The method described herein is safe, the instrumentation is compact and has potential to be modified so as to be portable for use in the field. It also can be used in conjunction with FID (flame ionization detector) or TCD (thermal conductivity detector), in which either no response for FID (CO2, N2, NO2, SO2, etc.) or helium gas is needed for TCD, respectively. PMID:23891209

  11. [Effects of gaseous compositions the on simultaneous removal of NO(x) and SO2 from simulated flue gas by ammonia absorption].

    PubMed

    Wang, Hong; Zhu, Tian-Le; Wang, Mei-Yan

    2013-01-01

    The effects of NO(x) oxidation ratio, O2 and SO2 concentrations in simulated flue gas as well as addition of S(IV) oxidation inhibitor NaS2O3 on the simultaneous removal of SO2 and NO(x) by ammonia absorption were investigated under the conditions of pH 5.9-6.1 and aqueous S(IV) concentration > or = 1.0 mol x L(-1). The research results showed that NO2 could be effectively absorbed by ammonium sulfite, but the NO absorption was negligible. Therefore, NO oxidation is the premise of NO(x) removal. Aqueous S(IV) concentration is a key factor affecting NO2 absorption removal, the higher the O2 concentration or the lower the SO2 concentration, the faster the aaqueous S(IV) concentration decreased, which resulted in a faster decrease of NO2 removal efficiency. S(IV) oxidation was inhibited to some extent by the addition of oxidation inhibitor S2O3(2-) into the absorption solution. As a result, the decrease of NO2 removal efficiency became slower. PMID:23487913

  12. 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

  13. 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.

  14. 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.

  15. $\\frac{{\\rm SO}(2N)}{U(N)}$ 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.

  16. Mobile MAX-DOAS observation of NO2 and comparison with OMI satellite data in the western coastal areas of the Korean peninsula.

    PubMed

    Chong, Jihyo; Kim, Young J; Gu, Myojeong; Wagner, Thomas; Song, Chul H

    2016-01-01

    Ground-based MAX-DOAS measurements have been used to retrieve column densities of atmospheric absorbers such as NO2, SO2, HCHO, and O3. In this study, mobile MAX-DOAS measurements were conducted to map the 2-D distributions of atmospheric NO2 in the western coastal areas of the Korean peninsula. A Mini-MAX-DOAS instrument was mounted on the rooftop of a mobile lab vehicle with a telescope mounted parallel to the driving direction, pointing forward. The measurements were conducted from 21 to 24 December 2010 along the western coastal areas from Gomso harbor (35.59N, 126.61E) to Gunsan harbor (35.98N, 126.67E). During mobile MAX-DOAS observations, high elevation angles were used to avoid shades from nearby obstacles. For the determination of the tropospheric vertical column density (VCD), the air mass factor (AMF) was retrieved by the so-called geometric approximation. The NO2 VCDs from 20 and 45 degree elevation angles were retrieved from mobile MAX-DOAS measurements. The tropospheric NO2 VCDs derived from mobile MAX-DOAS measurements were compared directly to those retrieved by the OMI satellite observations. Mobile MAX-DOAS VCD was in good agreement with OMI tropospheric VCD on most days. However, OMI tropospheric VCD was much higher than that of mobile MAX-DOAS on 23 December 2010. One probable reason for this difference is that OMI retrieval might overestimate NO2 VCD under haze conditions, when a pollution plume was transported over the measurement site. The mobile MAX-DOAS observations reveal much finer spatial patterns of NO2 distributions, which can provide useful information for the validation of satellite observation of atmospheric trace gases. PMID:26239513

  17. 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

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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)...

  3. 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)...

  4. 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)...

  5. 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)...

  6. 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)...

  7. 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)...

  8. 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)...

  9. 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)...

  10. 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)...

  11. 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)...

  12. 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...

  13. 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...

  14. 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...

  15. 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.

  16. 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.

  17. 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...

  18. 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,...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. Satellite observations of NO2 trend over Romania.

    PubMed

    Constantin, Daniel-Eduard; Voiculescu, Mirela; Georgescu, Lucian

    2013-01-01

    Satellite-based measurements of atmospheric trace gases loading give a realistic image of atmospheric pollution at global, regional, and urban level. The aim of this paper is to investigate the trend of atmospheric NO2 content over Romania for the period 1996-2010 for several regions which are generally characterized by different pollutant loadings, resulting from GOME-1, SCIAMACHY, OMI, and GOME-2 instruments. Satellite results are then compared with ground-based in situ measurements made in industrial and relatively clean areas of one major city in Romania. This twofold approach will help in estimating whether the trend of NO2 obtained by means of data satellite retrievals can be connected with the evolution of national industry and transportation. PMID:24453819

  11. Satellite Observations of NO2 Trend over Romania

    PubMed Central

    Voiculescu, Mirela; Georgescu, Lucian

    2013-01-01

    Satellite-based measurements of atmospheric trace gases loading give a realistic image of atmospheric pollution at global, regional, and urban level. The aim of this paper is to investigate the trend of atmospheric NO2 content over Romania for the period 1996–2010 for several regions which are generally characterized by different pollutant loadings, resulting from GOME-1, SCIAMACHY, OMI, and GOME-2 instruments. Satellite results are then compared with ground-based in situ measurements made in industrial and relatively clean areas of one major city in Romania. This twofold approach will help in estimating whether the trend of NO2 obtained by means of data satellite retrievals can be connected with the evolution of national industry and transportation. PMID:24453819

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Sulfur tolerance of selective partial oxidation of NO to NO2 in a plasma

    SciTech Connect

    Penetrante, B; Brusasco, R M; Merritt, B T; Vogtlin, G E

    1999-08-24

    Several catalytic aftertreatment technologies rely on the conversion of NO to NO2 to achieve efficient reduction of NOx and particulates in diesel exhaust. These technologies include the use of selective catalytic reduction of NOx with hydrocarbons, NOx adsorption, and continuously regenerated particulate trapping. These technologies require low sulfur fuel because the catalyst component that is active in converting NO to NO2 is also active in converting SO2 to SO3 . The SO3 leads t o increase in particulates and/or poison active sites on the catalyst. A non-thermal plasma can be used for the selective partial oxidation of NO to NO2 in the gas-phase under diesel engine exhaust conditions. This paper discusses how a non-thermal plasma can efficiently oxidize NO to NO2 without oxidizing SO2 to SO3 .

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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).

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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

  11. Primary quantum yields of NO2 photodissociation

    NASA Technical Reports Server (NTRS)

    Gardner, Edward P.; Sperry, Paul D.; Calvert, Jack G.

    1987-01-01

    The quantum yields of formation of NO, O2, and NO2 loss are measured for NO2 vapor at low pressures (0.13-0.30 torr) irradiated at 334-405 nm wavelengths and temperature in the range 273-370 K in order to study the primary quantum efficiencies of NO2 photodecomposition. The temperature and wavelength dependences of the primary quantum efficiencies are examined. It is observed that the primary quantum efficiencies increase rapidly from near zero at 424 nm to near unity for excitation at wavelengths less than 394 nm. The theory of Pitts et al. (1964) that the energy deficiency for photodissociation of NO2 excited at wavelengths greater than 397.9 nm is due to the rotational and vibrational energy of the NO2 molecules is confirmed by the data. Values for the primary quantum yields of NO2 photodecomposition as a function of wavelength are presented.

  12. 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

  13. Kinetics of soot oxidation by NO2

    SciTech Connect

    Shrivastava, ManishKumar B.; Nguyen, Anh; Zheng, Zhongqing; Wu, Hao-Wei; Jung, Hee-Jung

    2010-06-15

    Modern technologies use NO2 to promote low temperature soot oxidation for diesel particulate filter regeneration. Most previous methods studied soot oxidation with NO2 using offline methods such as thermo-gravimetric analysis (TGA). In this study, the online aerosol-technique of high-temperature oxidation tandem differential mobility analysis (HTO-TDMA) is used to study kinetics of soot oxidation with NO2 under N2 environment. This method has significant advantages over previous offline methods in reducing heat and mass transfer diffusion limitations to the soot surface. Soot particles are exposed to varying temperature and NO2 concentration inside the furnace resulting from thermal decomposition of NO2 to NO. This causes soot oxidation rates to vary throughout the furnace. In this study, variations in temperatures, NO2 concentrations and particle residence times are thoroughly accounted for the first time, and soot oxidation rates are derived. Soot oxidation rate is calculated as a function of Arrhenius rate constant Asoot, activation energy Esoot, and partial pressure of NO2 PNO2 within the furnace at temperatures ranging 500- 950 C. Results suggest Asoot and Esoot values for soot oxidation with NO2 of 1.68 nm K-0.5 s-1 (Nm-2)-n and 46.5 kJ mol-1 respectively. The activation energy for soot oxidation with NO2 is significantly lower than oxidation with air. However, ppm levels of NO2 cause soot oxidation at low temperatures suggesting NO2 is a stronger oxidant than O2. This study also shows that a semi-empirical approach with just a few kinetic parameters could represent varying soot oxidation rates in a diesel engine cylinder or on a diesel particulate filter. Further studies should be directed towards understanding synergistic effects of other oxidants as O2 and H2O in addition to NO2 using the HTO-TDMA method.

  14. 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.

  15. 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.

  16. 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.`

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. Measurements of SO2 concentration and atmospheric structure in Delta and Breton wildlife refuges

    SciTech Connect

    Hsu, S.A.

    1995-04-01

    A field program designed to measure the ambient concentrations of SO2 as well as pertinent meteorological parameters was conducted during the summer of 1993. Three stations were established in the EPA Class 1 areas of Breton and Delta Wildlife Refuges near the mouth of the Mississippi River. It was found that the SO2 concentration measured throughout the monitoring duration was only 2% of the National maximum allowable once per year. The passage of a weak cold front in September showed that the SO2 concentrations were higher when the wind blew from land to the Gulf than under normal summer conditions when the wind blew from the Gulf toward land.

  9. Regional differences in Chinese SO2 emission control efficiency and policy implications

    NASA Astrophysics Data System (ADS)

    Zhang, Q. Q.; Wang, Y.; Ma, Q.; Yao, Y.; Xie, Y.; He, K.

    2015-06-01

    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 to reduce the national total SO2 emissions by 8% or 2.3 Tg below the 2010 emissions level, the target set by the current twelfth Five-Year Plan (FYP; 2011-2015), but differ in spatial implementation. The GEOS-Chem chemical transport model is used to evaluate the efficiency of each scenario on the basis of four impact metrics: surface SO2 and sulfate concentrations, 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 in SO2 emissions from the 2010 baseline. The S1 scenario, which adopts a spatially uniform reduction in SO2 emissions in China, gives a β of 0.99, 0.71, 0.83, and 0.67 for SO2 and sulfate concentrations, 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 SO2 and sulfate concentrations and sulfur export fluxes, with β being 1.0, 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 with large benefits within the region. The difference in β by scenario is attributable to the regional difference in SO2 oxidation pathways and the source-receptor relationship. Among the three regions examined here, NC shows the largest proportion of sulfate formation through gas

  10. Industrial SO2 emissions monitoring using a portable multi-channel gas analyzer with an optimized retrieval algorithm

    NASA Astrophysics Data System (ADS)

    Sun, Y. W.; Liu, C.; Xie, P. H.; Hartl, A.; Chan, K. L.; Tian, Y.; Wang, W.; Qin, M.; Liu, J. G.; Liu, W. Q.

    2015-12-01

    In this paper, we demonstrate achieving accurate industrial SO2 emissions monitoring using a portable multi-channel gas analyzer with an optimized retrieval algorithm. The introduced analyzer features with large dynamic measurement range and correction of interferences from other co-existing infrared absorbers, e.g., NO, CO, CO2, NO2, CH4, HC, N2O and H2O. Both effects have been the major limitations of industrial SO2 emissions monitoring. The multi-channel gas analyzer measures 11 different wavelength channels simultaneously in order to achieve correction of 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 makes use of a 3rd polynomial rather than a constant factor to quantify gas-to-gas interference. The measurement results show good performance in both linear and nonlinear range, thereby solving the problem that the conventional interference correction is restricted by the linearity of both intended and interfering channels. The result implies that the measurement range of the developed multi-channel analyzer can be extended to the nonlinear absorption region. The measurement range and accuracy are evaluated by experimental laboratory calibration. An excellent agreement was achieved with a Pearson correlation coefficient (r2) of 0.99977 with measurement range from ~5 ppmv to 10 000 ppmv and measurement error <2 %. The instrument was also deployed for field measurement. Emissions from 3 different factories were measured. The emissions of these factories have been characterized with different co-existing infrared absorbers, covering a wide range of concentration levels. We compared our measurements with the commercial SO2 analyzers. The overall good agreements are achieved.

  11. Soot and SO2 contribution to the supersites in the MILAGRO campaign from elevated flares in the Tula Refinery

    NASA Astrophysics Data System (ADS)

    Almanza, V. H.; Molina, L. T.; Sosa, G.

    2012-11-01

    This work presents a simulation of the plume trajectory emitted by flaring activities of the Miguel Hidalgo Refinery in Mexico. The flame of a representative sour gas flare is modeled with a CFD combustion code in order to estimate emission rates of combustion by-products of interest for air quality: acetylene, ethylene, nitrogen oxides, carbon monoxide, soot and sulfur dioxide. The emission rates of NO2 and SO2 were compared with measurements obtained at Tula as part of MILAGRO field campaign. The rates of soot, VOCs and CO emissions were compared with estimates obtained by Instituto Mexicano del Petróleo (IMP). The emission rates of these species were further included in WRF-Chem model to simulate the chemical transport of the plume from 22 to 27 March of 2006. The model presents reliable performance of the resolved meteorology, with respect to the Mean Absolute Error (MAE), Root Mean Square Error (RMSE), mean bias (BIAS), vector RMSE and Index of Agreement (IOA). WRF-Chem outputs of SO2 and soot were compared with surface measurements obtained at the three supersites of MILAGRO campaign. The results suggest a contribution of Tula flaring activities to the total SO2 levels of 18% to 27% at the urban supersite (T0), and of 10% to 18% at the suburban supersite (T1). For soot, the model predicts low contribution at the three supersites, with less than 0.1% at three supersites. According to the model, the greatest contribution of both pollutants to the three supersites occurred on 23 March, which coincides with the third cold surge event reported during the campaign.

  12. Molecular transport and phase transition of polycrystalline ice doped with HCl and SO2 near its melting point

    NASA Astrophysics Data System (ADS)

    Lu, H.; McCartney, S.; Sadtchenko, V.

    2007-12-01

    HCl and SO2 are major trace gases in atmosphere, which greatly affects chemical properties of atmospheric ice particles. A particular interest to atmospheric science is the effects of impurities on molecular transport and phase transition at grain boundaries in polycrystalline ice. Effects of doped HCl and SO2 on transport and phase transition at grain boundary of 2-4 micrometer polycrystalline ice were studied using a novel technique - Fast Thermal Desorption Spectroscopy (FTDS) [1] in the temperature range from -2 to -20 deg. C. In these experiments, H2O/D2O/H2O sandwich-like polycrystalline ice films doped with HCl and SO2 were vapor- deposited on the surface of a thin filament positioned in a vacuum chamber and maintained initially at cryogenic temperatures. After the deposition, the temperature of the filament was rapidly raised to a value near ice melting point, thus, initiating rapids H/D exchange reaction at the interface of H2O and D2O layers. Diffusion controlled rate of isotopic exchange in the desorbing film was monitored with a sensitive mass-spectrometer making it possible to gain quantitative information of the extent of diffusion of chemical species along the grain boundaries in polycrystalline ice samples. Comparisons of the experimental results in pure and doped polycrystalline ice show that water self diffusivity at the grain boundaries is significantly enhanced (by at least an order of magnitude) in the presence of HCl or SO2. The strong, non- Arrhenius, dependence of the water self-diffusivity on temperature indicates that this is due to grain boundary premelting [2], which may occur at temperatures as low as 10 deg. below ice melting point. We will discuss implication of this and other results of our FTDS experiments to various environmental phenomena. References: 1. Haiping Lu, Stephanie A. McCartney, M. Chonde, D. Smyla, and Vlad Sadtchenko, Fast thermal desorption spectroscopy study of morphology and vaporization kinetics of polycrystalline

  13. High-sensitivity detection of hazardous SO(2) using 266 nm UV laser.

    PubMed

    Gondal, Mohammed A; Dastageer, Mohamed A

    2008-08-01

    Pulsed laser resonant photoacoustic spectroscopy was applied for detection of highly toxic SO(2) with 266 nm as the excitation source. An extra-cavity longitudinal resonant cell, was designed and fabricated to enhance the sensitivity of the system, which is capable of detecting the trace amount of SO(2). As a process of signal-to-noise ratio optimization, the parametric dependence of the PA signal was carried out and the sensitivity achieved with our system was as low as 4 ppb, which is considered to be a sufficient level for the detection of ambient SO(2) in the atmosphere. This study could be an antecedent for the design of a portable SO(2) sensor. PMID:18584428

  14. On Io's 2.788-micron band: Origin by SO2 or H2O?

    NASA Technical Reports Server (NTRS)

    Nash, Douglas B.

    1994-01-01

    Laboratory reflectance spectra of SO2 frost and ice and thin H2O frost show that the recently reported band at 2.788 microns in Io's disk-integrated spectrum can be qualitatively explained by the presence of solid SO2 on Io's surface. However, the reported width of the Io band is too great to be explained by SO2 frost or ice alone. Lab spectra presented here, and other data cited here, show clearly that solid SO2 has a strong band at 2.789 microns, and that Io should have such a band. These results do not support the claim of Bregman et al. that H2O is the primary cause of the Io band.

  15. On Io's 2.788-micron band: Origin by SO2 or H2O?

    NASA Astrophysics Data System (ADS)

    Nash, D. B.

    1994-02-01

    Laboratory reflectance spectra of SO2 frost and ice and thin H2O frost show that the recently reported band at 2.788 microns in Io's disk-integrated spectrum can be qualitatively explained by the presence of solid SO2 on Io's surface. However, the reported width of the Io band is too great to be explained by SO2 frost or ice alone. Lab spectra presented here, and other data cited here, show clearly that solid SO2 has a strong band at 2.789 microns, and that Io should have such a band. These results do not support the claim of Bregman et al. that H2O is the primary cause of the Io band.

  16. BrO/SO2 ratios at Popocatepetl volcano during increased activity in 2012

    NASA Astrophysics Data System (ADS)

    Fickel, M.; Delgado Granados, H.

    2012-12-01

    Since its reactivation in 1994 after many decades of inactivity, Popocatepetl volcano has been showing long periods of quiescent degassing and some events of intensified activity in connection with dome building and destruction processes. During a period of increased activity of the volcano, which began in April 2012, mobile ultraviolet DOAS measurements and stationary DOAS scans were performed to quantify SO2 fluxes and BrO/SO2 ratios within the volcanic plume. The results of these measurements are presented in the context of the volcanic activity, which consisted of increased emission of gas and ash and Vulcanian type explosions. In general, SO2 emissions were high during the period April-June 2012 and so the BrO emissions, however, the BrO/SO2 ratios did not change strongly before, during and after the increased activity.

  17. Electrochemical processes in a high power Li-SO2 source

    NASA Astrophysics Data System (ADS)

    Ksenzhek, O. S.; Shembel, E. M.

    1983-11-01

    It is noted in the present study of factors defining the characteristics of a high power Li-SO2 chemical current source that, while the solid phase product of SO2's cathodic reduction passivates the electrode surface, it is gradually dissolved after deenergizing. The specific characteristics of the Li-SO2 cell are therefore higher on intermittent than on continuous discharge. The rate of SO2 cathodic reduction and the electrochemical stability range are greater in perchlorate than in bromide solutions, and the discharge capacity is higher in acetonitrile solutions than in those based on propylene carbonate. The anodic behavior of a Li electrode is determined by the properties of the film passivating its surface, and the polarization resistance at anodic dissolution is practically equal to the ohmic resistance of the film, whose electrochemical properties are conditioned by its semiconductive nature.

  18. Flue gas treatment for SO2 removal with air-sparged hydrocyclone technology.

    PubMed

    Bokotko, Romuald P; Hupka, Jan; Miller, Jan D

    2005-02-15

    Laboratory results from an initial study on the removal of SO2 from gas mixtures are reported using air-sparged hydrocyclone (ASH) technology. Tap water and alkaline solutions were used for absorption, and the influence of gas flow rate, water flow rate, and length of the ASH unit were investigated. The research results indicate thatthe air-sparged hydrocyclone can be used as a highly efficient absorber for SO2 emissions. The ASH allows for 97% SO2 removal using water alone for sulfur dioxide content in the gas phase of 5 g/m3. All SO2 is removed in weakly alkaline solution (0.01 mol NaOH/dm3). PMID:15773494

  19. Plasma-chemical oxidation of SO2 in air by pulsed electron beams

    NASA Astrophysics Data System (ADS)

    Novoselov, Y. N.; Mesyats, G. A.; Kuznetsov, D. L.

    2001-04-01

    The results are given of detailed experimental studies of the model flue gas mixture irradiation by pulsed electron beams and electron-beam-initiated non-self-sustained discharges. The effects of the electron beam parameters, the external electric field and the composition of irradiated gas on the process of sulphur dioxide SO2 removal are analysed. We demonstrate the existence of optimum values of the electron beam current density and pulse duration, and of the external electric field strength, at which the energy required to remove one SO2 molecule is minimum. The energy cost and removal rate are given as functions of the concentration of SO2, oxygen and water vapour in the mixture. The concentration limit that divides the chain and radical mechanisms of SO2 removal is determined.

  20. FACTORS AFFECTING DRY DEPOSITION OF SO2 ON FORESTS AND GRASSLANDS

    EPA Science Inventory

    Deposition velocities for SO2 over forests and grasslands are derived through a mass conservation approach using established empirical relations descriptive of the atmospheric transport of a gaseous contaminant above and within a vegetational canopy. Of particular interest are si...

  1. A relationship between agricultural NH 3 emissions and the atmospheric SO 2 content over industrial areas

    NASA Astrophysics Data System (ADS)

    Möller, Detlev; Schieferdecker, Helmut

    In an industrial area of the GDR, where there are major locations of lignite strip mines and lignite-fired power stations, a decline in the mean large-area SO 2 concentration was observed despite a slight increase in SO 2 emissions, between 1970 and 1980. It was found that the NH 3 emissions from biogenic sources had increased by some 20 per cent in the same period. This paper shows that a growing NH 3 concentration produces a nonlinear reduction of the SO 2 content of the atmosphere. In relative terms, the greatest such effect is observed in cases where NH 3 concentrations are low ( < 5 ppbv). Atmospheric NH 3 increases the relative percentage of the SO 2 wet deposition. Alkaline fly ashes derive their importance from the fact that NH 3 is formed from soil-deposited NH 4+ and can be re-released into the atmosphere, thus possibly giving rise to multiple cycles.

  2. A laboratory study of the effect of NO 2 on the atmospheric corrosion of zinc

    NASA Astrophysics Data System (ADS)

    Castaño, J. G.; de la Fuente, D.; Morcillo, M.

    Studies on the effect of NO x on zinc corrosion are scarce and their results are variable and at times seemingly contradictory. This paper reports laboratory tests involving the dry deposition on zinc surfaces of 800 μg m -3 NO 2, alone and in combination with 800 μg m -3 SO 2, at temperatures of 35 and 25 °C and relative humidities of 90% and 70%. From the gravimetric results obtained and from the characterisation of the corrosion products by optical microscopy, scanning electron microscopy (SEM/EDX), grazing incidence X-ray diffraction (GIXD) and X-ray photoelectron spectroscopy (XPS), it has been verified that the corrosive action of NO 2 alone is negligible compared with SO 2. However, an accelerating effect has been observed when NO 2 acts in conjunction with SO 2 at 25 °C and 90% RH. At 35 °C and 90% RH, the accelerating effect is smaller, and at low relative humidities (70%), the synergistic effect is only slight, which suggests it may be favoured by the presence of moisture. In those cases where an accelerating effect has been observed, a greater proportion of sulphate ions has been found in the corrosion products, and nitrogen compounds have not been detected, indicating that NO 2 participates indirectly as a catalyst of the oxidation of SO 2 to sulphate.

  3. Changes in SO2 flux degassing regime prior to the 2014 Stromboli eruption

    NASA Astrophysics Data System (ADS)

    Tamburello, Giancarlo; Delle Donne, Dario; Ripepe, Maurizio; Bitetto, Marcello; Cosenza, Paolo; Giudice, Gaetano; Riccobono, Giuseppe; Aiuppa, Alessandro

    2015-04-01

    Volcanic eruptions are often accompanied by release of huge amounts of magmatic SO2. Capturing sizeable precursory SO2 flux variations prior to eruption has revealed far more challenging, instead, in spite of the recent progresses in instrumental gas monitoring. Here, we report on the SO2 fluxes variations we detected at Stromboli volcano prior to the effusive eruption started on the 6th August 2014. The SO2 fluxes were regularly quantified at high-rate (0.5 Hz) using two fully autonomous permanent SO2 camera devices installed - within the framework the ERC-FP7 project "Bridge"- at two sites located at 0.5 km (Roccette) and 1.75 km (Sciara del Fuoco rim) distance from the crater terrace. This system provided sufficient spatial resolution, (~0.4 m) to allow for separate evaluation of gas emissions from the centrals/NE craters (CC and NEC, ~150 t/d on average) and from the northern hornitos (NH, ~15 t/d on average) that was active in summer 2014. Notwithstanding its marginal contribution to the total SO2 flux, the NH was vigorously active before the effusive eruption onset, and produced a large number of ash-free explosions, which individual SO2 output was easily measurable at high sampling rate with the SO2 cameras. From the beginning of June 2014, the NH exhibited a progressive increase of its explosive SO2 release (from ~1 t/d up to ~5 t/d) which culminated in correspondence with a sequence of lava overflows on the beginning of July 2014. A notable correlation between the explosive degassing pattern and co-acquired acoustic pressure and satellite-derived Volcanic Radiative Power was observed. The relative contributions of the individual degassing craters to the total gas emissions varied in response to the displacement of the magma level within the conduits, with the largest SO2 fluxes being observed during lava overflows. Our results here indicate detectable changes in the relative gas contribution from the different craters and in their degassing modes, although

  4. Measurements of volcanic SO2 with ASTER. Comparison with automated scanning DOAS measurements

    NASA Astrophysics Data System (ADS)

    Campion, R. A.; Salerno, G. G.; Bernard, A. M.; Burton, M.; Coheur, P.; Caltabiano, T.

    2009-12-01

    Sulfur dioxide (SO2) emitted by volcanoes has an important impact on the environment and climate and is also a critical parameter for volcano monitoring. A number of satellites operating in the ultra violet and in the Thermal infrared can measure SO2. However a lot of work has still to be done towards a rigorous validation of SO2 measurements from space. ASTER (Advanced Spaceborne Thermal Emission Reflection radiometer) acquires images in the thermal infrared (TIR) with a resolution of 90m/pixel, which enables to quantify the SO2 fluxes emitted in small-scale tropospheric plumes. ASTER images are processed with radiative transfer simulations and a band ratio algorithm to produce maps of SO2 column amounts. The band ratios (B10+B12)/B11 and B14/B11 are used for their insensitivity to variations in ground altitude and atmospheric humidity, two variables that often complicate SO2 retrievals in the TIR. Their sensitivity to surface emissivity is also reduced. So far, the ground validation of satellite SO2 measurements has been complex due to logistics difficulties and the lack of strictly simultaneous measurements. Recently the development of permanent networks of scanning DOAS on several active volcanoes has provide a wealth of ground based SO2 measurements that can be exploited for validating satellite-based measurements. We will present the results of comparisons between SO2 Column Amount (CA) and fluxes measured by ASTER and by the FLAME network of Mt. Etna. The two independent measurements sets are in good agreement in magnitude. Fluxes range from 2000 to 5000 T/days and column amounts from 0 to 4 g/m2. CAs measured by ASTER present a 0.5g/m2 random dispersion and no systematic bias compared to DOAS measurements. However the CAs measured by DOAS are subject to increase at low-scanning angles. These results constitute a rigorous ground validation of ASTER SO2, and provides valuable insights into accuracy and precision on both methodologies. Figure 1: Comparison

  5. SO2 in the Fall in the Arctic: Source Identification Using Sulfur Isotopes

    NASA Astrophysics Data System (ADS)

    Norman, A. L.; Seguin, A.; Rempillo, O. T.

    2011-12-01

    The Arctic atmosphere, although far from industrial sources, has a large anthropogenic SO2 load. Sulfur dioxide can have other sources including from dimethylsulphide (DMS) oxidation. One way to distinguish between these two types of SO2 is through sulfur isotope apportionment. During the Fall seasons of 2007 and 2008 aerosol sulfate and SO2 were measured at two sites in the Arctic. One site was on board the Canadian Coast Guard Ship, The Amundsen, as it traveled throughout the Arctic and the other site was at Alert, Nunavut, Canada. Sulfur dioxide concentrations at Alert varied between 0.02 and 18 nmol/m3 throughout the study with a median of 0.4 nmol/m3. δ34S values ranged between 0 and +11%. Concentrations and δ34S values aboard the Amundsen were much more diverse with concentrations ranging between 0.09 and 134 nmol/m3 (2007 median = 9.4 nmol/m3; 2008 median = 2.0 nmol/m3) and δ34S values ranging between -15 and +18%. High concentrations of SO2 on board the Amundsen were not directly from the Amundsen itself as there was no correlation with peaks in coincident CO2 measurements. Low concentrations of SO2 may, in a few instances, be associated with DMS oxidation. Negative δ34S values were present for samples collected near the Amundsen Gulf and are consistent with a third source of SO2 in the Arctic. This is likely the local source of SO2 from the Smoking Hills in the North West Territories. Distinguishing between these sources of SO2 in the Arctic and the importance of local verses regional sources will be discussed.

  6. SO2 interaction with Zn(0001) and ZnO(0001) and the influence of water

    NASA Astrophysics Data System (ADS)

    Önsten, Anneli; Stoltz, Dunja; Palmgren, Pål; Yu, Shun; Claesson, Thomas; Göthelid, Mats; Karlsson, Ulf O.

    2013-02-01

    Photoelectron spectroscopy has been used to study room temperature adsorption of sulfur dioxide on clean and water exposed (0001) surfaces of zinc and zinc oxide. Water has no significant effect either on clean or on SO2 exposed Zn(0001) at the low water pressures used (p < 10- 7 mbar). In the case of the zinc-terminated ZnO(0001) surface, however, water adsorbs dissociatively and OH groups are shown to have a considerable effect on SO2 surface reactions. A strong oxidation reaction occurs between Zn(0001) and SO2 giving various sulfur containing species. On ZnO(0001), SO2 interacts mainly with oxygen sites giving SO3 or SO4 species. It is shown that the ZnO(0001) sample preparation procedure can have large effects on surface chemical and physical properties. Samples cleaned by four different preparation procedures are investigated, namely sputtering only and sputtering followed by annealing at 450 °C, 530 °C and 600-650 °C. Annealing at 600 °C leads to a transition from a partly OH-terminated surface to a triangularly structured surface free from OH groups. Adsorption of SO2 on the latter surface leads to a decreased surface conductivity, which hampers photoemission measurements. Water is shown to block SO2 adsorption sites on both 450 °C and 530 °C annealed samples. On the latter sample, SO2 reduction has been observed to a small extent on the clean surface and to a larger extent when the surface is prehydroxylated. Here, we speculate that water, similar to hydrogen, generates surface zinc clusters on ZnO(0001). Zinc clusters could enable charge transfer to the antibonding LUMO of the SO2 molecule and subsequent dissociation.

  7. Yield response curves of crops exposed to SO 2 time series

    NASA Astrophysics Data System (ADS)

    Male, Larry; Preston, Eric; Neely, Grady

    Six species (alfalfa, onion, lettuce, radish, red clover, Douglas fir) were exposed in field growth chambers to both constant concentration and stochastic SO 2 time series. Yield response curves were generated with median concentrations ranging from 0 to 20 pphm. Constant concentration treatments were found to underestimate yield loss compared with the pollutant time series treatments. An heuristic model of plant assimilation of SO 2 is presented to explain this result.

  8. Simultaneous oxidation of NO, SO2 and Hg0 from flue gas by pulsed corona discharge.

    PubMed

    Xu, Fei; Luo, Zhongyang; Cao, Wei; Wang, Peng; Wei, Bo; Gao, Xiang; Fang, Mengxiang; Cen, Kefa

    2009-01-01

    A process capable of simultaneously oxidizing NO, SO2, and Hg0 was proposed, using a high-voltage and short-duration positive pulsed corona discharge. By focusing on NO, SO2, and Hg0 oxidation efficiencies, the influences of pulse peak voltage, pulse frequency, initial concentration, electrode number, residence time and water vapor addition were investigated. The results indicate that NO, SO2 and Hg0 oxidation efficiencies depend primarily on the radicals (OH, HO2, O) and the active species (O3, H2O2, etc.) produced by the pulsed corona discharge. The NO, SO2 and Hg0 oxidation efficiencies could be improved as pulse peak voltage, pulse frequency, electrode number and residence time increased, but they were reduced with increasing initial concentrations. By adding water vapor, the SO2 oxidation efficiency was improved remarkably, while the NO oxidation efficiency decreased slightly. In our experiments, the simultaneous NO, SO2, and Hg0 oxidation efficiencies reached to 40%, 98%, and 55% with the initial concentrations 479 mg/m3, 1040 mg/m3, and 15.0 microg/m3, respectively. PMID:19634444

  9. 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

  10. 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

  11. Identification of Large Emission Sources of SO2 in Mexico Megacity