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1

Pyrogenic and Biogenic Emissions of NMVOCs inferred from GOME Formaldehyde data  

NASA Astrophysics Data System (ADS)

The formaldehyde columns retrieved by the GOME satellite instrument between 1997 and 2002 are used together with the IMAGES global chemistry transport model and its adjoint to provide top-down estimates for biomass burning and biogenic NMVOC emissions on the global scale. The formaldehyde retrievals use the differential optical absorption spectroscopy technique (DOAS). Altitude-resolved air mass factors (AMFs), taking into account relevant parameters like surface albedo, cloud coverage and ground altitude, are consistently applied to formaldehyde profiles derived from the CTM. In view of the large number and diversity of NMVOCs involved in the production of CH2O in the troposphere, an extensive preliminary study has been conducted using the quasi-explicit chemical mechanisms (like the Master Chemical Mechanism, MCM) in order to determine the formaldehyde yields in the oxidation of the most prominent NMVOCs (ca. 20 compounds). Next, we use these results to optimize the chemical mechanism of the CTM with respect to formaldehyde production. The emissions of the most reactive CH2O precursors are optimized using the GOME CH2O data, whereas the emissions of slowly reacting species, e.g. ethane, acetone, methanol should be optimized using direct observations of these compounds. The inversion is based on the grid-based approach, previously applied to the optimization of CO fluxes in IMAGES by Stavrakou and Muller, JGR, 2006. In this framework, the biomass burning and biogenic NMVOC emissions are optimized at the horizontal resolution of 5x5 degrees of the IMAGES CTM. As the number of control parameters to be optimized in this study is quite large (on the order of 20,000 for one year), source specific spatial correlations among errors on the prior emissions are introduced in order to reduce the number of effective unknowns. Temporal correlations are also considered to account for the relationship between the emissions updates from different years and different months.

Muller, J.; Stavrakou, T.; de Smedt, I.; van Roozendael, M.

2006-12-01

2

Space-nadir observations of formaldehyde columns in the 1995-2008 period and their use for inferring NMVOC emissions through inverse modelling.  

NASA Astrophysics Data System (ADS)

Non-methane volatile organic compounds (NMVOCs) of both natural and anthropogenic origin play an important role in the formation of tropospheric ozone. Despite recent efforts to improve existing databases of NMVOC emissions, large uncertainties still remain mainly due to the diversity of the sources and the complexity of the mechanisms involved. Satellite observations of formaldehyde (CH2O) provide useful information to test and improve bottom-up inventories of NMVOC emissions because CH2O is an intermediate product in the oxidation of a large number of NMVOCs and its lifetime is only a few hours. Since 1995, global distributions of CH2O columns have been retrieved from the GOME, SCIAMACHY, OMI and GOME-2 UV-Vis nadir sounders. The retrieval of CH2O by differential absorption spectroscopy (DOAS) is challenging mainly due to the overall faintness of the CH2O signal, but also due to uncertainties in the calculation of air mass factors. To ensure the coherence of long time series of observations based on the combination of different satellite sounders, retrieval settings must be homogenized while taking into account instrumental specificities and eventual limitations of each sounder. Currently, one of the main limitations of the CH2O retrieval from UV-Vis satellites is the random error of the slant column. For single pixels, this error dominates the other sources of uncertainty. It can be reduced by averaging a large number of observations and to this regard, new instruments like OMI and GOME-2, which offer a much better global coverage of the earth, have the capacity to improve the statistics on the CH2O columns and to allow for more selective cloud screening. Recent achievements but also problems and limitations of the currently available sounders are highlighted. This points to the need for improved satellite instruments, both from LEO and GEO orbital configurations. We finally illustrate the potential of satellite CH2O observations for the inverse modelling of NMVOCs emissions, based on the use of the IMAGESv2 global tropospheric chemistry transport model. Results are shown for biogenic and pyrogenic emissions of VOCs. Anthropogenic emissions are currently more difficult to constrain because of the low signal to noise ratio of the CH2O columns in polluted regions. We discuss the interest and potential of combining CH2O observations with glyoxal measurements from the same sensors.

de Smedt, I.; van Roozendael, M.; Lerot, C.; Müller, J.-F.; Stavrakou, T.; Kurosu, T.; Wittrock, F.

2009-04-01

3

Emission and speciation of non-methane volatile organic compounds from anthropogenic sources in China  

Microsoft Academic Search

An emission inventory of non-methane volatile organic compounds (NMVOCs) from anthropogenic sources in China was compiled for the year 2005. The NMVOC emissions were 20.1Tg, of which industrial and domestic solvent use, road transportation, and bio-fuel combustion contributed 28.6%, 23.4%, and 18.0%, respectively. Emissions were speciated into 40 species according to their atmospheric photochemical reactivity, toxicity, and model applicability. Of

Wei Wei; Shuxiao Wang; Satoru Chatani; Zbigniew Klimont; Janusz Cofala; Jiming Hao

2008-01-01

4

Non-methane volatile organic compound emission inventories in Beijing during Olympic Games 2008  

NASA Astrophysics Data System (ADS)

Non-methane volatile organic compounds (NMVOCs) play important roles in ground-level ozone and secondary organic aerosol (SOA) formation. To evaluate the effectiveness of air quality control measures in Beijing in 2008, NMVOC emission inventories were compiled for June, July, August, and September with emission factors and updated activity data. Total NMVOC emissions were 22.6, 20.2, 14.9, and 14.6 Gg in June, July, August, and September, respectively. Anthropogenic NMVOC emissions were 45% lower in August than June; vehicles, solvent utilization, industrial processing, and miscellaneous sources declined by 66, 48, 15, and 75%, respectively. Anthropogenic NMVOC emissions increased in September compared with August. NMVOC emissions from petroleum storage and transport varied little during these months because of the installation of low-fugitive facilities. Reduced emissions from vehicles, industrial processing, and petroleum storage and transport contributed to the total anthropogenic reduction. Inventory uncertainties were evaluated to be [-51%, +126%], [-56%, +146%], [-58%, +161%], and [-52%, +133%] in June, July, August, and September, respectively, at the 95% confidence level.

Su, Junhua; Shao, Min; Lu, Sihua; Xie, Yangyang

2011-12-01

5

Natural emissions of non-methane volatile organic compounds, carbon monoxide, and oxides of nitrogen from North America  

Microsoft Academic Search

The magnitudes, distributions, controlling processes and uncertainties associated with North American natural emissions of oxidant precursors are reviewed. Natural emissions are responsible for a major portion of the compounds, including non-methane volatile organic compounds (NMVOC), carbon monoxide (CO) and nitric oxide (NO), that determine tropospheric oxidant concentrations. Natural sources include soil microbes, vegetation, biomass burning, and lightning. These sources are

Alex Guenther; Chris Geron; Tom Pierce; Brian Lamb; Peter Harley; Ray Fall

2000-01-01

6

Global NMVOC fluxes inferred from SCIAMACHY formaldehyde columns through 2003-2006  

NASA Astrophysics Data System (ADS)

Formaldehyde (HCHO) columns retrieved from the SCIAMACHY satellite instrument through 2003 to 2006 are used as top-down constraints to derive updated global biogenic and biomass burning flux estimates for the non-methane volatile organic compounds (NMVOCs) precursors of formaldehyde. Our interest is centered over regions experiencing strong emissions, and hence exhibit a high signal-to-noise ratio and lower measurement uncertainties. The HCHO dataset used in this study has been recently made available to the community and complements the long record of formaldehyde measurements from the GOME instrument. HCHO columns are simulated by the IMAGESv2 global chemistry- transport model. The model is driven by the Global Fire Emission Database (GFED) version 1 and 2 inventories for vegetation fires, and the MEGAN-ECMWF isoprene emission database. The adjoint of the model is implemented in a grid-based framework within which both biogenic and pyrogenic emission fluxes are derived at the model resolution. Two inversion studies are conducted using either the GFEDv1 or GFEDv2 as prior for the pyrogenic fluxes. The updated NMVOC emissions are presented and compared with results from previous studies, whereas a number of sensitivity experiments are conducted in order to assess the impact of the inversion setup on the robustness of the inferred fluxes.

Muller, J.; Stavrakou, T.; de Smedt, I.; van Roozendael, M.

2008-12-01

7

Intraannual cycles of NMVOCs in the tropical troposphere and their use for interpreting seasonal variability in CO  

NASA Astrophysics Data System (ADS)

18 month's data of non-methane volatile organic compound (NMVOC) and carbon monoxide (CO) concentrations obtained from the Cape Verde Atmospheric Observatory (Observatório Atmosferico de Cabo Verde: Humberto Duarte Fonseca CVAO, 16,848°N, 24.871°W) in the tropical Atlantic Ocean are presented here. The CO measurements demonstrate the expected sinusoidal curve driven by its loss reaction with OH, but with a smaller amplitude than modelling studies would suggest for this region. Simultaneous ethane measurements were used to derive the seasonal variation in the "nominal hydroxyl radical (OH) concentration (n[OH])" experienced along the air mass trajectory of ethane, by assuming a fixed ethane emission rate. The n[OH] represents the variability in OH concentration assuming there are no intraannual changes in ethane emissions, and was subsequently used to create seasonal fits of CO concentrations, allowing interpretation of differing sources and sinks from those of ethane. Deviation of the measured CO concentrations from their "n[OH] fit" indicates that summer sources of CO are approximately 60% higher than winter, assuming that ethane is not lost through reactions with chlorine or bromine atoms. Evidence suggests that the production of CO from the oxidation of CH4 and NMVOC and in particular from methanol, acetone and acetaldehyde (from both terrestrial and oceanic sources) is increased in this region in summer and this could be an explanation for the observations. Other NMVOC measurements are presented here as indicators of potential conflicting halogen chemistry and of alternative emission sources. Longer-term measurements of NMVOC and CO, such as those presented in this paper, are essential for our understanding of the oxidation capacity, atmospheric processes and composition of the atmosphere.

Read, K.; Carpenter, L.; Lewis, A.; Lee, J.; Neves, L.; Faria, B.

2009-04-01

8

Space-based formaldehyde measurements as constraints on volatile organic compound emissions in east and south Asia and implications for ozone  

Microsoft Academic Search

We use a continuous 6-year record (1996–2001) of GOME satellite measurements of formaldehyde (HCHO) columns over east and south Asia to improve regional emission estimates of reactive nonmethane volatile organic compounds (NMVOCs), including isoprene, alkenes, HCHO, and xylenes. Mean monthly HCHO observations are compared to simulated HCHO columns from the GEOS-Chem chemical transport model using state-of-science, “bottom-up” emission inventories from

Tzung-May Fu; Daniel J. Jacob; Paul I. Palmer; Kelly Chance; Yuxuan X. Wang; Barbara Barletta; Donald R. Blake; Jenny C. Stanton; Michael J. Pilling

2007-01-01

9

Emission and speciation of non-methane volatile organic compounds from anthropogenic sources in China  

NASA Astrophysics Data System (ADS)

An emission inventory of non-methane volatile organic compounds (NMVOCs) from anthropogenic sources in China was compiled for the year 2005. The NMVOC emissions were 20.1 Tg, of which industrial and domestic solvent use, road transportation, and bio-fuel combustion contributed 28.6%, 23.4%, and 18.0%, respectively. Emissions were speciated into 40 species according to their atmospheric photochemical reactivity, toxicity, and model applicability. Of the total emissions, alkanes account for 29.8%, followed by aromatics (21.9%), alkenes and alkynes (21.0%), and carbonyls (17.8%). Emissions at the provincial level were spatially allocated onto grids with a resolution of 36 km×36 km, according to population distribution. Furthermore, the provincial and sectoral emissions of nine toxic species, including n-hexane, 1,3-butadiene, styrene, benzene, toluene, xylene, methanol, formaldehyde, and acraldehyde, are also analyzed. Finally, the national total emissions were considered with an uncertainty of [-44%,+109%] in 95% confidence interval, by using the Monte Carlo method.

Wei, Wei; Wang, Shuxiao; Chatani, Satoru; Klimont, Zbigniew; Cofala, Janusz; Hao, Jiming

10

Boreal forest fire emissions in fresh Canadian smoke plumes: C1-C10 volatile organic compounds (VOCs), CO2, CO, NO2, NO, HCN and CH3CN  

NASA Astrophysics Data System (ADS)

Boreal regions comprise about 17% of the global land area, and they both affect and are influenced by climate change. To better understand boreal forest fire emissions and plume evolution, 947 whole air samples were collected aboard the NASA DC-8 research aircraft in summer 2008 as part of the ARCTAS-B field mission, and analyzed for 79 non-methane volatile organic compounds (NMVOCs) using gas chromatography. Together with simultaneous measurements of CO2, CO, CH4, CH2O, NO2, NO, HCN and CH3CN, these measurements represent the most comprehensive assessment of trace gas emissions from boreal forest fires to date. Based on 105 air samples collected in fresh Canadian smoke plumes, 57 of the 80 measured NMVOCs (including CH2O) were emitted from the fires, including 45 species that were quantified from boreal forest fires for the first time. After CO2, CO and CH4, the largest emission factors (EFs) for individual species were formaldehyde (2.1 ± 0.2 g kg-1), followed by methanol, NO2, HCN, ethene, ?-pinene, ?-pinene, ethane, benzene, propene, acetone and CH3CN. Globally, we estimate that boreal forest fires release 2.4 ± 0.6 Tg C yr-1 in the form of NMVOCs, with approximately 41% of the carbon released as C1-C2 NMVOCs and 21% as pinenes. These are the first reported field measurements of monoterpene emissions from boreal forest fires, and we speculate that the pinenes, which are relatively heavy molecules, were detected in the fire plumes as the result of distillation of stored terpenes as the vegetation is heated. Their inclusion in smoke chemistry models is expected to improve model predictions of secondary organic aerosol (SOA) formation. The fire-averaged EF of dichloromethane or CH2Cl2, (6.9 ± 8.6) ×10-4 g kg-1, was not significantly different from zero and supports recent findings that its global biomass burning source appears to have been overestimated. Similarly, we found no evidence for emissions of chloroform (CHCl3) or methyl chloroform (CH3CCl3) from boreal forest fires. The speciated hydrocarbon measurements presented here show the importance of carbon released by short-chain NMVOCs, the strong contribution of pinene emissions from boreal forest fires, and the wide range of compound classes in the most abundantly emitted NMVOCs, all of which can be used to improve biomass burning inventories in local/global models and reduce uncertainties in model estimates of trace gas emissions and their impact on the atmosphere.

Simpson, I. J.; Akagi, S. K.; Barletta, B.; Blake, N. J.; Choi, Y.; Diskin, G. S.; Fried, A.; Fuelberg, H. E.; Meinardi, S.; Rowland, F. S.; Vay, S. A.; Weinheimer, A. J.; Wennberg, P. O.; Wiebring, P.; Wisthaler, A.; Yang, M.; Yokelson, R. J.; Blake, D. R.

2011-03-01

11

Boreal forest fire emissions in fresh Canadian smoke plumes: C1-C10 volatile organic compounds (VOCs), CO2, CO, NO2, NO, HCN and CH3CN  

NASA Astrophysics Data System (ADS)

Boreal regions comprise about 17 % of the global land area, and they both affect and are influenced by climate change. To better understand boreal forest fire emissions and plume evolution, 947 whole air samples were collected aboard the NASA DC-8 research aircraft in summer 2008 as part of the ARCTAS-B field mission, and analyzed for 79 non-methane volatile organic compounds (NMVOCs) using gas chromatography. Together with simultaneous measurements of CO2, CO, CH4, CH2O, NO2, NO, HCN and CH3CN, these measurements represent the most comprehensive assessment of trace gas emissions from boreal forest fires to date. Based on 105 air samples collected in fresh Canadian smoke plumes, 57 of the 80 measured NMVOCs (including CH2O) were emitted from the fires, including 45 species that were quantified from boreal forest fires for the first time. After CO2, CO and CH4, the largest emission factors (EFs) for individual species were formaldehyde (2.1 ± 0.2 g kg-1), followed by methanol, NO2, HCN, ethene, ?-pinene, ?-pinene, ethane, benzene, propene, acetone and CH3CN. Globally, we estimate that boreal forest fires release 2.4 ± 0.6 Tg C yr-1 in the form of NMVOCs, with approximately 41 % of the carbon released as C1-C2 NMVOCs and 21 % as pinenes. These are the first reported field measurements of monoterpene emissions from boreal forest fires, and we speculate that the pinenes, which are relatively heavy molecules, were detected in the fire plumes as the result of distillation of stored terpenes as the vegetation is heated. Their inclusion in smoke chemistry models is expected to improve model predictions of secondary organic aerosol (SOA) formation. The fire-averaged EF of dichloromethane or CH2Cl2, (6.9 ± 8.6) × 10-4 g kg-1, was not significantly different from zero and supports recent findings that its global biomass burning source appears to have been overestimated. Similarly, we found no evidence for emissions of chloroform (CHCl3) or methyl chloroform (CH3CCl3) from boreal forest fires. The speciated hydrocarbon measurements presented here show the importance of carbon released by short-chain NMVOCs, the strong contribution of pinene emissions from boreal forest fires, and the wide range of compound classes in the most abundantly emitted NMVOCs, all of which can be used to improve biomass burning inventories in local/global models and reduce uncertainties in model estimates of trace gas emissions and their impact on the atmosphere.

Simpson, I. J.; Akagi, S. K.; Barletta, B.; Blake, N. J.; Choi, Y.; Diskin, G. S.; Fried, A.; Fuelberg, H. E.; Meinardi, S.; Rowland, F. S.; Vay, S. A.; Weinheimer, A. J.; Wennberg, P. O.; Wiebring, P.; Wisthaler, A.; Yang, M.; Yokelson, R. J.; Blake, D. R.

2011-07-01

12

Intra-annual cycles of NMVOC in the tropical marine boundary layer and their use for interpreting seasonal variability in CO  

NASA Astrophysics Data System (ADS)

Carbon monoxide and nonmethane volatile organic compounds (NMVOC) have been measured for the first time on a continuous basis in the tropical marine boundary layer of the Atlantic Ocean. CO and ethane, which have similar lifetimes with respect to OH degradation, vary intra-annually with the sinusoidal variability expected due to a primary hydroxyl radical (OH) sink, but with CO showing a smaller cycle amplitude. The ethane measurements were used to derive the seasonal variation in the nominal OH concentration (n[OH]) experienced along the air mass trajectories arriving at Cape Verde. The n[OH] represents the variability in both the true OH concentration and any intra-annual changes in ethane emissions, and was subsequently used to simulate the seasonal cycle of CO, allowing identification of potentially differing sources and sinks from those of ethane. Deviation of the observed CO from the n[OH] fit indicated that summer sources of CO are approximately 60% (30-68%) higher than winter, assuming values of ±8% and ±49% seasonal variability, respectively, in fossil fuel and biomass burning emissions of CO and ethane, and including -29% uncertainty due to the losses of ethane through reaction with chlorine atoms. The evidence suggests that secondary production of CO from the oxidation of methane (CH4) and NMVOC and in particular from methanol, acetone and acetaldehyde may be dominant summer CO sources in this region.

Read, K. A.; Lee, J. D.; Lewis, A. C.; Moller, S. J.; Mendes, L.; Carpenter, L. J.

2009-11-01

13

Inventorying emissions from nature in Europe  

Microsoft Academic Search

As part of the work of the Economic Commission for Europe of the United Nations Task Force on Emission Inventories, a new set of guidelines has been developed for assessing the emissions of sulphur, nitrogen oxides, NH3, CH4, and nonmethane volatile organic compounds (NMVOC) from biogenic and other natural sources in Europe. This paper gives the background to these guidelines,

David Simpson; Wilfried Winiwarter; Gunnar Börjesson; Steve Cinderby; Antonio Ferreiro; Alex Guenther; C. Nicholas Hewitt; Robert Janson; M. Aslam K. Khalil; Susan Owen; Tom E. Pierce; Hans Puxbaum; Martha Shearer; Ute Skiba; Rainer Steinbrecher; Leonor Tarrasón; Mats G. Öquist

1999-01-01

14

Compilation and analyses of emissions inventories for the NOAA atmospheric chemistry project. Progress report, August 1997  

SciTech Connect

Global inventories of anthropogenic emissions of oxides of nitrogen for circa 1985 and 1990 and non-methane volatile organic compounds (NMVOCs) for circa 1990 have been compiled by this project. Work on the inventories has been carried out under the umbrella of the Global Emissions Inventory Activity of the International Global Atmospheric Chemistry program. Global emissions of NOx for 1985 are estimated to be 21 Tg N/yr, with approximately 84% originating in the Northern Hemisphere. The global emissions for 1990 are 31 Tg N/yr for NOx and 173 Gg NMVOC/yr. Ongoing research activities for this project continue to address emissions of both NOx and NMVOCs. Future tasks include: evaluation of more detailed regional emissions estimates and update of the default 1990 inventories with the appropriate estimates; derivation of quantitative uncertainty estimates for the emission values; and development of emissions estimates for 1995.

Benkovitz, C.M.

1997-09-01

15

Fire emissions constrained by the synergistic use of formaldehyde and glyoxal SCIAMACHY columns in a two-compound inverse modelling framework  

NASA Astrophysics Data System (ADS)

Formaldehyde (HCHO) and glyoxal (CHOCHO) are carbonyls formed in the oxidation of volatile organic compounds (VOCs) emitted by plants, anthropogenic activities, and biomass burning. They are also directly emitted by fires. Although this primary production represents only a small part of the global source for both species, yet it can be locally important during intense fire events. Simultaneous observations of formaldehyde and glyoxal retrieved from the SCIAMACHY satellite instrument in 2005 and provided by the BIRA/IASB and the Bremen group, respectively, are compared with the corresponding columns simulated with the IMAGESv2 global CTM. The chemical mechanism has been optimized with respect to HCHO and CHOCHO production from pyrogenically emitted NMVOCs, based on the Master Chemical Mechanism (MCM) and on an explicit profile for biomass burning emissions. Gas-to-particle conversion of glyoxal in clouds and in aqueous aerosols is considered in the model. In this study we provide top-down estimates for fire emissions of HCHO and CHOCHO precursors by performing a two- compound inversion of emissions using the adjoint of the IMAGES model. The pyrogenic fluxes are optimized at the model resolution. The two-compound inversion offers the advantage that the information gained from measurements of one species constrains the sources of both compounds, due to the existence of common precursors. In a first inversion, only the burnt biomass amounts are optimized. In subsequent simulations, the emission factors for key individual NMVOC compounds are also varied.

Stavrakou, T.; Muller, J.; de Smedt, I.; van Roozendael, M.; Vrekoussis, M.; Wittrock, F.; Richter, A.; Burrows, J.

2008-12-01

16

Intra-annual cycles of NMVOC in the tropical marine boundary layer and their use for interpreting seasonal variability in CO  

Microsoft Academic Search

Carbon monoxide and nonmethane volatile organic compounds (NMVOC) have been measured for the first time on a continuous basis in the tropical marine boundary layer of the Atlantic Ocean. CO and ethane, which have similar lifetimes with respect to OH degradation, vary intra-annually with the sinusoidal variability expected due to a primary hydroxyl radical (OH) sink, but with CO showing

K. A. Read; J. D. Lee; A. C. Lewis; S. J. Moller; L. Mendes; L. J. Carpenter

2009-01-01

17

COMPILATION AND ANALYSES OF EMISSIONS INVENTORIES FOR THE NOAA ATMOSPHERIC CHEMISTRY PROJECT. PROGRESS REPORT, AUGUST 1997.  

SciTech Connect

Global inventories of anthropogenic emissions of oxides of nitrogen (NO{sub x}) for circa 1985 and 1990 and Non-Methane Volatile Organic Compounds (NMVOCs) for circa 1990 have been compiled by this project. Work on the inventories has been carried out under the umbrella of the Global Emissions Inventory Activity (GEIA) of the International Global Atmospheric Chemistry (IGAC) Program. The 1985 NO{sub x} inventory was compiled using default data sets of global emissions that were refined via the use of more detailed regional data sets; this inventory is being distributed to the scientific community at large as the GEIA Version 1A inventory. Global emissions of NO{sub x} for 1985 are estimated to be 21 Tg N y{sup -1}, with approximately 84% originating in the Northern Hemisphere. The 1990 inventories of NO{sub x} and NMVOCs were compiled using unified methodologies and data sets in collaboration with the Netherlands National Institute of Public Health and Environmental Protection (Rijksinstituut Voor Volksgezondheid en Milieuhygiene, RIVM) and the Division of Technology for Society of the Netherlands Organization for Applied Scientific Research, (IMW-TNO); these emissions will be used as the default estimates to be updated with more accurate regional data. The NMVOC inventory was gridded and speciated into 23 chemical categories. The resulting global emissions for 1990 are 31 Tg N yr{sup -1} for NO{sub x} and 173 Gg NMVOC yr{sup -1}. Emissions of NO{sub x} are highest in the populated and industrialized areas of eastern North America and across Europe, and in biomass burning areas of South America, Africa, and Asia. Emissions of NMVOCs are highest in biomass burning areas of South America, Africa, and Asia. The 1990 NO{sub x} emissions were gridded to 1{sup o} resolution using surrogate data, and were given seasonal, two-vertical-level resolution and speciated into NO and NO{sub 2} based on proportions derived from the 1985 GEIA Version 1B inventory. Global NMVOC emissions were given additional species resolution by allocating the 23 chemical categories to individual chemical species based on factors derived from the speciated emissions of NMVOCs in the U.S. from the U.S. EPA's 1990 Interim Inventory. Ongoing research activities for this project continue to address emissions of both NO{sub x} and NMVOCs. Future tasks include: (a) evaluation of more detailed regional emissions estimates and update of the default 1990 inventories with the appropriate estimates, (b) derivation of quantitative uncertainty estimates for the emission values, and (c) development of emissions estimates for 1995.

BENKOVITZ,C.M.

1997-09-01

18

Modeling of global biogenic emissions for key indirect greenhouse gases and their response to atmospheric CO2 increases and changes in land cover and climate  

Microsoft Academic Search

Natural emissions of nonmethane volatile organic compounds (NMVOCs) play a crucial role in the oxidation capacity of the lower atmosphere and changes in concentrations of major greenhouse gases (GHGs), particularly methane and tropospheric ozone. In this study, we integrate a global biogenic model within a terrestrial ecosystem model to investigate the vegetation and soil emissions of key indirect GHGs, e.g.,

Zhining Tao; Atul K. Jain

2005-01-01

19

Compilation and Analyses of Emissions Inventories for NOAA's Atmospheric Chemistry Project.  

National Technical Information Service (NTIS)

Global inventories of anthropogenic emissions of oxides of nitrogen (NO(sub x)) for circa 1985 and 1990 and Non-Methane Volatile Organic Compounds (NMVOCs) for circa 1990 have been compiled by this project. Work on the inventories has been carried out und...

C. M. Benkovitz M. A. Mubaraki

1997-01-01

20

Complex fragment emission from hot compound nuclei  

SciTech Connect

The experimental evidence for compound nucleus emission of complex fragments at low energies is used to interpret the emission of the same fragments at higher energies. The resulting experimental picture is that of highly excited compound nuclei formed in incomplete fusion processes which decay statistically. In particular, complex fragments appear to be produced mostly through compound nucleus decay. In the appendix a geometric-kinematic theory for incomplete fusion and the associated momentum transfer is outlined. 10 refs., 19 figs.

Moretto, L.G.

1986-03-01

21

Isoprene emission from Indian trees  

NASA Astrophysics Data System (ADS)

Isoprene is the most dominant non-methane volatile organic compound (NMVOC) emitted by plants. NMVOCs play an important role in regulating the composition of atmospheric trace gases including global concentration of tropospheric ozone. Our present knowledge about NMVOCs emission is mainly from studies on temperate tree species. So far information on biogenic NMVOCs emission from tropical tree species is limited. In this study, isoprene emission rates from 40 tropical Indian tree species belonging to 33 genera and 17 families were measured for the first time using a dynamic flow through enclosure chamber technique. The isoprene emission rate from plants (30°C and PAR 1000 ?molm-2s-1) ranged from undetectable to 81.5 ?g g-1 h-1 and values were found to be comparable with other studies on tropical tree species. Tree species screened for isoprene emission in the present study may be grouped into the four categories, proposed by [2001], namely, 18 species were negligible or BDL isoprene emitting (<1 ?g g-1 h-1), 6 species were low emitting (1 ? to <10 ?g g-1 h-1), 5 species were moderate emitting (10? to <25 ?g g-1 h-1), and 11 species were high isoprene emitting (?25 ?g g-1 h-1). Maximum isoprene emission rate (81.5 ?g g-1 h-1) was observed in the case of Dalbergia sissoo Linn. It was interesting to find that Citrus limon Linn., Citrus reticulata Linn., Citrus sinensis Linn., Grevillea robusta A. Cunn., and Morus alba Linn., which were earlier reported as BDL or non isoprene emitters in US [, 1998; , 2001] were found to be appreciably high isoprene emitters (0.61-21.60 ?g g-1 h-1) in the present study.

Varshney, C. K.; Singh, Abhai Pratap

2003-12-01

22

Volatile Organic Compound Emissions by Agricultural Crops  

NASA Astrophysics Data System (ADS)

Biogenic Volatile Organic Compounds (BVOCs) participate in ozone and aerosol formation, and comprise a substantial fraction of reactive VOC emission inventories. In the agriculturally intensive Central Valley of California, emissions from crops may substantially influence regional air quality, but emission potentials have not been extensively studied with advanced instrumentation for many important crops. Because crop emissions may vary according to the species, and California emission inventories are constructed via a bottom-up approach, a better knowledge of the emission rate at the species-specific level is critical for reducing uncertainties in emission inventories and evaluating emission model performance. In the present study we identified and quantified the BVOCs released by dominant agricultural crops in California. A screening study to investigate both volatile and semivolatile BVOC fractions (oxygenated VOCs, isoprene, monoterepenes, sesquiterpenes, etc.) was performed for 25 crop species (at least 3 replicates plants each), including branch enclosures of woody species (e.g. peach, mandarin, grape, pistachio) and whole plant enclosures for herbaceous species (e.g. onion, alfalfa, carrot), through a dynamic cuvette system with detection by PTRMS, in-situ GCMS/FID, and collection on carbon-based adsorbents followed by extraction and GCMS analysis. Emission data obtained in this study will allow inclusion of these crops in BVOC emission inventories and air quality simulations.

Ormeno, E.; Farres, S.; Gentner, D.; Park, J.; McKay, M.; Karlik, J.; Goldstein, A.

2008-12-01

23

GLOBAL INVENTORY OF VOLATILE ORGANIC COMPOUND EMISSIONS FORM ANTHROPOGENIC SOURCES  

EPA Science Inventory

The report describes a global inventory anthropogenic volatile organic compound (VOC) emissions that includes a separate inventory for each of seven pollutant groups--paraffins, olefins, aromatics, formaldehyde, other aldehydes, other aromatics, and marginally reactive compounds....

24

GLOBAL INVENTORY OF VOLATILE COMPOUND EMISSIONS FROM ANTHROPOGENIC SOURCES  

EPA Science Inventory

The report describes a global inventory anthropogenic volatile organic compound (VOC) emissions that includes a separate inventory for each of seven pollutant groups--paraffins, olefins, aromatics, formaldehyde, other aldehydes, other aromatics, and marginally reactive compounds....

25

Effects of additional nonmethane volatile organic compounds, organic nitrates, and direct emissions of oxygenated organic species on global tropospheric chemistry  

NASA Astrophysics Data System (ADS)

This work evaluates the sensitivity of tropospheric ozone and its precursors to the representation of nonmethane volatile organic compounds (NMVOCs) and organic nitrates. A global 3-D tropospheric chemistry/transport model (IMPACT) has been exercised initially using the GEOS-Chem chemical reaction mechanism. The model was then extended by adding emissions and photochemical reactions for aromatic and terpenoid hydrocarbons, and by adding explicit representation of hydroxy alkyl nitrates produced from isoprene. Emissions of methanol, phenol, acetic acid and formic acid associated with biomass burning were also added. Results show that O3 increases by 20% in most of the troposphere, peroxyacetyl nitrate (PAN) increases by 30% over much of the troposphere and OH increases by 10%. NOx (NO + NO2) decreases near source regions and increases in remote locations, reflecting increased transport of NOx away from source regions by organic nitrates. The increase in O3 was driven largely by the increased role of PAN as a transporter of NOx and by the rerelease of NOx from isoprene nitrates. The increased PAN production was associated with increases in methyl glyoxal and hydroxyacetone. Comparison with measured values show reasonable agreement for O3 and PAN, but model measurement agreement does not either improve or degrade in the extended model. The extended model shows improved agreement with measurements for methanol, acetic acid and peroxypropional nitrate (PPN). Results from the extended model were consistent with measured alkyl nitrates and glycolaldehyde, but hydroxyacetone and methyl glyoxal were overestimated. The latter suggests that the effect of the isoprene nitrates is somewhat smaller than estimated here. Although the model measurement comparison does not show specific improvements with the extended model, it provides a more complete description of tropospheric chemistry that we believe is important to include.

Ito, Akinori; Sillman, Sanford; Penner, Joyce E.

2007-03-01

26

Volatile organic compound emissions from dairy facilities in central California  

Technology Transfer Automated Retrieval System (TEKTRAN)

Emissions of volatile organic compounds (VOCs) from dairy facilities are thought to be an important contributor to high ozone levels in central California, but emissions inventories from these sources contain significant uncertainties. In this work, VOC emissions were measured at two central Califor...

27

Assessment of volatile organic compound emissions from ecosystems of China  

Microsoft Academic Search

Isoprene, monoterpene, and other volatile organic compound (VOC) emissions from grasslands, shrublands, forests, and peatlands in China were characterized to estimate their regional magnitudes and to compare these emissions with those from landscapes of North America, Europe, and Africa. Ecological and VOC emission sampling was conducted at 52 sites centered in and around major research stations located in seven different

L. F. Klinger; Q.-J. Li; A. B. Guenther; J. P. Greenberg; B. Baker; J.-H. Bai

2002-01-01

28

Compilation and analyses of emissions inventories for NOAA`s atmospheric chemistry project. Progress report, August 1997  

SciTech Connect

Global inventories of anthropogenic emissions of oxides of nitrogen (NO{sub x}) for circa 1985 and 1990 and Non-Methane Volatile Organic Compounds (NMVOCs) for circa 1990 have been compiled by this project. Work on the inventories has been carried out under the umbrella of the Global Emissions Inventory Activity (GEIA) of the International Global Atmospheric Chemistry (IGAC) Program. The 1985 NO{sub x} inventory was compiled using default data sets of global emissions that were refined via the use of more detailed regional data sets; this inventory is being distributed to the scientific community at large as the GEIA Version 1A inventory. Global emissions of NO{sub x} for 1985 are estimated to be 21 Tg N y{sup -1}, with approximately 84% originating in the Northern Hemisphere. The 1990 inventories of NO{sub x} and NMVOCs were compiled using unified methodologies and data sets in collaboration with the Netherlands National Institute of Public Health and Environmental Protection (Rijksinstituut Voor Volksgezondheid en Milieuhygiene, RIVM) and the Division of Technology for Society of the Netherlands Organization for Applied Scientific Research, (IMW-TNO); these emissions will be used as the default estimates to be updated with more accurate regional data. The NMVOC inventory was gridded and speciated into 23 chemical categories.

Benkovitz, C.M.; Mubaraki, M.A.

1997-09-01

29

POTENTIAL EMISSIONS OF HAZARDOUS ORGANIC COMPOUNDS FROM SEWAGE SLUDGE INCINERATION  

EPA Science Inventory

Laboratory thermal decomposition studies were undertaken to evaluate potential organic emissions from sewage sludge incinerators. Precisely controlled thermal decomposition experiments were conducted on sludge spiked with mixtures of hazardous organic compounds, on the mixtures o...

30

GLOBAL INVENTORY OF VOLATILE ORGANIC COMPOUND EMISSIONS FROM ANTHROPOGENIC SOURCES  

EPA Science Inventory

The paper discusses the development of a global inventory of anthropogenic volatile organic compound (VOC) emissions. t includes VOC estimates for seven classes of VOCs: paraffins, olefins, aromatics (benzene, toluene, xylene), formaldehyde, other aldehydes, other aromatics, and ...

31

COMPOUND FORMS OF FOSSIL FUEL FLY ASH EMISSIONS  

EPA Science Inventory

A methodology for identifying inorganic compounds in particulate emissions from fossil fuel combustion processes is described. Samples collected from power plants burning coal and oil fuels of different compositions provided a typical range of fly ashes for the investigations. El...

32

Determination of total volatile organic compound emissions from furniture polishes  

Microsoft Academic Search

In this study, an environmental test chamber with controlled temperature, relative humidity, and airflow rate was developed\\u000a to evaluate emissions of total volatile organic compounds (TVOCs) from three different kinds of furniture polish. The time\\u000a dependence of TVOC concentrations produced from the emissions of furniture polish products in the chamber was tested. TVOC\\u000a emissions from each furniture polish were compared.

Hai Guo; Frank Murray

2001-01-01

33

[Emission volatile organic compounds from new textile floor coverings].  

PubMed

The emission of formaldehyde and the other volatile organic compounds (toluene, styrene, 4-PC) and total volatile organic compounds (VOCs) from new textile floor coverings was measured with the use of environmental chamber (0.6 m3 capacity) in the following conditions: temperature 23 degrees C, relative humidity 45%, 1 exchange/hour and factor loading 1 m2 m-3. The formaldehyde was determined by using colorimetric method, VOCs by GC method. The tested carpets did not emit formaldehyde. The emission of other volatile organic compounds was very low and fulfill known requirements. PMID:12621886

Igielska, Barbara; Pecka, Irena; Sitko, Elzbieta; Nikel, Grazyna; Wiglusz, Renata

2002-01-01

34

Key unknowns in estimating atmospheric emissions from UK land management  

NASA Astrophysics Data System (ADS)

Robust emission inventories of atmospheric pollutants are critical to understanding and predicting impacts, identifying key sources and mitigation opportunities. The objective of this study was to review the extent to which UK land management is accounted for as a source of emission of ammonia (NH 3), nitrous oxide (N 2O), nitrogen oxides (NO x), organic nitrogen (N org), methane (CH 4), non-methane volatile organic compounds (NMVOC), particulate matter (PM) and heavy metals (HM), in comparison with the current state of scientific knowledge; to ascertain whether there is evidence for significant gaps or that key emission sources have been overlooked. The processes leading to emissions of NH 3, N 2O and CH 4 are largely understood and all major sources are thought to be captured in the current inventory. Quantification of uncertainties in the estimates for some of these sources is still required, as is an assessment of the potential improvement in accuracy of estimates through the development of country-specific emission factors for N 2O and CH 4 in particular. There is limited knowledge about sources and processes leading to emissions of N org and the role that these may play in local and global nitrogen budgets. Land management is known to be a source of NO x, NMVOC and PM emissions, and potentially also HM emissions. Improved quantification is required to assess the importance of land management as a source of these pollutants in comparison with other sectors and, if appropriate, to determine the potential for mitigation.

Misselbrook, T. H.; Cape, J. N.; Cardenas, L. M.; Chadwick, D. R.; Dragosits, U.; Hobbs, P. J.; Nemitz, E.; Reis, S.; Skiba, U.; Sutton, M. A.

2011-02-01

35

Emission of volatile organic compounds (VOCs) from PVC floor coverings.  

PubMed

In this study 29 PVC floor coverings were tested for emission of vinyl chloride (VC) and other volatile organic compounds (VOCs). A study on the effect of higher temperature on emission of VOCs from newly manufactured PVC flooring was also carried out. The study was conducted in climatic chamber, according to Polish Standard PN-89/Z-04021. GC method was used for analyzing of the compounds emitted. VC was not emitted from any of the floorings tested. Other VOCs were emitted in different concentrations. The influence of temperature on emission was conducted at temperatures of 23 degrees C and 35 degrees C from 2 hrs up to 180 days after introduction of materials in the chamber. The increase of temperature caused increase of total volatile organic compounds (TVOC) emission during 24 hrs of experiment. Then the emission was comparable for both temperatures. After 9 days emission of identified and unidentified compounds (TVOC) showed a rapid decay and stayed on very low level during a few months. The study conducted showed that PVC floorings after 10 days of installation in the room should not be source of indoor air contamination. PMID:10431652

Wiglusz, R; Igielska, B; Sitko, E; Nikel, G; Jarnuszkiewicz, I

1998-01-01

36

Emission of volatile organic compounds from silage: compounds, sources, and implications  

Technology Transfer Automated Retrieval System (TEKTRAN)

Silage, fermented cattle feed, has recently been identified as a significant source of volatile organic compounds (VOCs) emitted to the atmosphere. A small number of studies have measured VOC emission from silage, but not enough is known about the processes involved to accurately quantify emission r...

37

Emission of charged particles from excited compound nucleus  

SciTech Connect

The formation and decay of excited compound nucleus are studied within the dinuclear system model[1]. The cross sections of complex fragment emission are calculated and compared with experimental data for the reactions {sup 3}He+{sup 108}Ag, {sup 78,82}Kr+{sup 12}C. Angular momentum dependence of cluster emission in {sup 78}Kr+{sup 12}C and {sup 40}Ca+{sup 78}Kr reactions is demonstrated.

Kalandarov, Sh. A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Institute for Nuclear Physics, Tashkent (Uzbekistan); Adamian, G. G.; Antonenko, N. V. [Joint Institute for Nuclear Research, Dubna (Russian Federation)

2010-11-24

38

77 FR 46961 - Approval and Promulgation of Implementation Plans; Wisconsin; Volatile Organic Compound Emission...  

Federal Register 2010, 2011, 2012, 2013

...Implementation Plans; Wisconsin; Volatile Organic Compound Emission Control Measures for...Technology (RACT) for sources of Volatile Organic Compound (VOC) emissions in moderate...recordkeeping requirements, Volatile organic compounds. Dated: June 11, 2012....

2012-08-07

39

VOC (VOLATILE ORGANIC COMPOUND) FUGITIVE EMISSION PREDICTIVE MODEL - USER'S GUIDE  

EPA Science Inventory

The report discusses a mathematical model that can be used to evaluate the effectiveness of various leak detection and repair (LDAR) programs on controlling volatile organic compound (VOC) fugitive emissions from chemical, petroleum, and other process units. The report also descr...

40

Emission of complex fragments in compound nucleus decay  

SciTech Connect

The compound nucleus mechanism for complex fragment emission is discussed theoretically and demonstrated experimentally. The role of the potential energy as a function of mass asymmetry is shown in experimental charge distributions. This process is followed from near the threshold up to bombarding energies of several tens of MeV A. 12 refs., 12 figs.

Moretto, L.G.

1986-04-01

41

Volatile organic compound emission factors from roadside measurements  

Microsoft Academic Search

Volatile organic compounds (VOCs) play a significant role in the generation of urban photochemical smog. In addition, some VOCs, such as benzene, are harmful to human health. In Japan, motor vehicles are the dominant source of VOCs. Therefore, it is important to determine the emission of VOCs from vehicles in order to estimate human risk and the production mechanisms of

Hiroto Kawashima; Shigeki Minami; Yoshimichi Hanai; Akihiro Fushimi

2006-01-01

42

Volatile organic compound emissions from dry mill fuel ethanol production.  

PubMed

Ethanol fuel production is growing rapidly in the rural Midwest, and this growth presents potential environmental impacts. In 2002, the U.S. Environmental Protection Agency (EPA) and the Minnesota Pollution Control Agency (MPCA) entered into enforcement actions with 12 fuel ethanol plants in Minnesota. The enforcement actions uncovered underreported emissions and resulted in consent decrees that required pollution control equipment be installed. A key component of the consent decrees was a requirement to conduct emissions tests for volatile organic compounds (VOCs) with the goal of improving the characterization and control of emissions. The conventional VOC stack test method was thought to underquantify total VOC emissions from ethanol plants. A hybrid test method was also developed that involved quantification of individual VOC species. The resulting database of total and speciated VOC emissions from 10 fuel ethanol plants is relatively small, but it is the most extensive to date and has been used to develop and gauge compliance with permit limits and to estimate health risks in Minnesota. Emissions were highly variable among facilities and emissions units. In addition to the variability, the small number of samples and the presence of many values below detection limits complicate the analysis of the data. To account for these issues, a nested bootstrap procedure on the Kaplan-Meier method was used to calculate means and upper confidence limits. In general, the fermentation scrubbers and fluid bed coolers emitted the largest mass of VOC emissions. Across most facilities and emissions units ethanol was the pollutant emitted at the highest rate. Acetaldehyde, acetic acid, and ethyl acetate were also important emissions from some units. Emissions of total VOCs, ethanol, and some other species appeared to be a function of the beer feed rate, although the relationship was not reliable enough to develop a production rate-based emissions factor. PMID:17912928

Brady, Daniel; Pratt, Gregory C

2007-09-01

43

A biogenic volatile organic compound emission inventory for Hong Kong  

NASA Astrophysics Data System (ADS)

Biogenic volatile organic compounds (BVOCs) in the atmosphere react to form ozone and secondary organic aerosols, which deteriorate air quality, affect human health, and indirectly influence global climate changes. The present study aims to provide a preliminary assessment of BVOC emissions in Hong Kong (HKSAR). Thriteen local tree species were measured for their isoprene emission potential. Tree distribution was estimated for country park areas based on field survey data. Plant emission data obtained from measurements and the literature, tree distribution estimation data, land use information, and meteorological data were combined to estimate annual BVOC emissions of 8.6×10 9 g C for Hong Kong. Isoprene, monoterpenes, and other VOCs contributed about 30%, 40%, and 30% of the estimated total annual emissions, respectively. Although hundreds of plant species are found in Hong Kong country parks, the model results indicate that only 10 tree species contribute about 76% of total annual VOC emissions. Prominent seasonal and diurnal variations in emissions were also predicted by the model. The present study lays a solid foundation for future local research, and results can be applied for studying BVOC emissions in nearby southern China and Asian regions that share similar climate and plant distributions.

Tsui, Jeanie Kin-Yin; Guenther, Alex; Yip, Wing-Kin; Chen, Feng

44

Volatile Organic Compound Emissions from Dairy Facilities in Central California  

NASA Astrophysics Data System (ADS)

Emissions of volatile organic compounds (VOCs) from dairy facilities are thought to be an important contributor to high ozone levels in Central California, but emissions inventories from these sources contain significant uncertainties. In this work, VOC emissions were measured at two Central California dairies during 2010 and 2011. Isolation flux chambers were used to measure direct emissions from specific dairy sources, and upwind/downwind ambient profiles were measured from ground level up to heights of 60 m. Samples were collected using a combination of canisters and sorbent tubes, and were analyzed by GC-MS. Additional in-situ measurements were made using infra-red photoaccoustic detectors and Diode Laser Absorption Spectroscopy. Temperature and ozone profiles up to 250 m above ground level were also measured using a tethersonde. Substantial fluxes of a number of VOCs including alcohols, volatile fatty acids and esters were observed at both sites. Implications of these measurements for regional air quality will be discussed.

Hasson, A. S.; Ogunjemiyo, S. O.; Trabue, S.; Middala, S. R.; Ashkan, S.; Scoggin, K.; Vu, K. K.; Addala, L.; Olea, C.; Nana, L.; Scruggs, A. K.; Steele, J.; Shelton, T. C.; Osborne, B.; McHenry, J. R.

2011-12-01

45

Modeling of global biogenic emissions for key indirect greenhouse gases and their response to atmospheric CO2 increases and changes in land cover and climate  

NASA Astrophysics Data System (ADS)

Natural emissions of nonmethane volatile organic compounds (NMVOCs) play a crucial role in the oxidation capacity of the lower atmosphere and changes in concentrations of major greenhouse gases (GHGs), particularly methane and tropospheric ozone. In this study, we integrate a global biogenic model within a terrestrial ecosystem model to investigate the vegetation and soil emissions of key indirect GHGs, e.g., isoprene, monoterpene, other NMVOCs (OVOC), CO, and NOx. The combination of a high-resolution terrestrial ecosystem model with satellite data allows investigation of the potential changes in net primary productivity (NPP) and resultant biogenic emissions of indirect GHGs due to atmospheric CO2 increases and changes in climate and land use practices. Estimated global total annual vegetation emissions for isoprene, monoterpene, OVOC, and CO are 601, 103, 102, and 73 Tg C, respectively. Estimated NOx emissions from soils are 7.51 Tg N. The land cover changes for croplands generally lead to a decline of vegetation emissions for isoprene OVOC, whereas temperature and atmospheric CO2 increases lead to higher vegetation emissions. The modeled global mean isoprene emissions show relatively large seasonal variations over the previous 20 years from 1981 to 2000 (as much as 31% from year to year). Savanna and boreal forests show large seasonal variations, whereas tropical forests with high plant productivity throughout the year show small seasonal variations. Results of biogenic emissions from 1981 to 2000 indicate that the CO2 fertilization effect, along with changes in climate and land use, causes the overall up-trend in isoprene and OVOC emissions over the past 2 decades. This relationship suggests that future emission scenario estimations for NMVOCs should account for effects of CO2 and climate in order to more accurately estimate local, regional, and global chemical composition of the atmosphere, the global carbon budget, and radiation balance of the Earth-atmosphere system.

Tao, Zhining; Jain, Atul K.

2005-11-01

46

A global model of natural volatile organic compound emissions  

NASA Astrophysics Data System (ADS)

Numerical assessments of global air quality and potential changes in atmospheric chemical constituents require estimates of the surface fluxes of a variety of trace gas species. We have developed a global model to estimate emissions of volatile organic compounds from natural sources (NVOC). Methane is not considered here and has been reviewed in detail elsewhere. The model has a highly resolved spatial grid (0.5°×0.5° latitude/longitude) and generates hourly average emission estimates. Chemical species are grouped into four categories: isoprene, monoterpenes, other reactive VOC (ORVOC), and other VOC (OVOC). NVOC emissions from oceans are estimated as a function of geophysical variables from a general circulation model and ocean color satellite data. Emissions from plant foliage are estimated from ecosystem specific biomass and emission factors and algorithms describing light and temperature dependence of NVOC emissions. Foliar density estimates are based on climatic variables and satellite data. Temporal variations in the model are driven by monthly estimates of biomass and temperature and hourly light estimates. The annual global VOC flux is estimated to be 1150 Tg C, composed of 44% isoprene, 11% monoterpenes, 22.5% other reactive VOC, and 22.5% other VOC. Large uncertainties exist for each of these estimates and particularly for compounds other than isoprene and monoterpenes. Tropical woodlands (rain forest, seasonal, drought-deciduous, and savanna) contribute about half of all global natural VOC emissions. Croplands, shrublands and other woodlands contribute 10-20% apiece. Isoprene emissions calculated for temperate regions are as much as a factor of 5 higher than previous estimates.

Guenther, Alex; Hewitt, C. Nicholas; Erickson, David; Fall, Ray; Geron, Chris; Graedel, Tom; Harley, Peter; Klinger, Lee; Lerdau, Manuel; McKay, W. A.; Pierce, Tom; Scholes, Bob; Steinbrecher, Rainer; Tallamraju, Raja; Taylor, John; Zimmerman, Pat

1995-05-01

47

Effect of natural compounds on reducing formaldehyde emission from plywood  

NASA Astrophysics Data System (ADS)

The effects of natural compounds on reducing formaldehyde emission from plywood were investigated. Urea, catechin and vanillin were examined as the natural formaldehyde reducers. The microemission cell, with an internal volume of 35 ml, the maximum exposed test surface area of 177 cm 2 and an air purge flow rate of 50 ml min -1, was used to measure specific emission rate (SER). In the case of no reducer treatment, formaldehyde emission from plywood was fast and SERs were 4.4 mg m -2 h -1 at 30 °C and 15 mg m -2 h -1 at 60 °C. When this plywood was treated with the natural compounds, the SERs of formaldehyde were decreased at all temperatures. In the case of urea treatment, the SERs of formaldehyde decreased to 0.30 mg m -2 h -1 at 30 °C and 0.65 mg m -2 h -1 at 60 °C. When the urea treatment was applied to the inside of kitchen cabinet (made from plywood; 270 cm wide, 60 cm deep, 250 cm high), the concentration of formaldehyde was reduced substantially from 1600 to 130 ?g m -3. The reducing effect of formaldehyde continued during the observation period (6 months), with a mean concentration of 100 ?g m -3. Reducers in the plywood would react with released formaldehyde. Application of natural compounds such as urea, catechin and vanillin could provide a simple and effective approach for suppressing formaldehyde emission from plywood.

Uchiyama, Shigehisa; Matsushima, Erica; Kitao, Nahoko; Tokunaga, Hiroshi; Ando, Masanori; Otsubo, Yasufumi

48

Volatile organic compound emissions: an inventory for Western Europe  

SciTech Connect

The report gives details of an inventory compiled by CONCAWE and covering man-made non-methane volatile organic compound (VOC) emissions in Western Europe. The survey shows that the major man-made sources are road transport and solvents, each contributing around 40%. Total oil industry operations account for around 8%, with refining operations contribution about 2%. The major oil industry contribution comes from the distribution of gasoline, including vehicle refuelling (5%).

Edwards, A.H.; Campobasso, A.; Camps, R.; Cremer, G.; Long, M.D.

1986-01-01

49

Identification of nonmethane organic compound emissions from grassland vegetation  

Microsoft Academic Search

Emissions of nonmethane organic compounds (NMOCs) from grassland vegetation were collected in Summa® passivated stainless-steel canisters with a static enclosure technique and were analyzed by high-resolution gas chromatography with flame ionization and ion trap mass spectrometric detectors. Approximately 40NMOCs with 6–10 carbon atoms were observed in samples analyzed by high-resolution gas chromatography with the flame ionization detector. Nineteen NMOCs in

Yoshiko Fukui; Paul V. Doskey

2000-01-01

50

Compound forms of fossil fuel fly ash emissions  

Microsoft Academic Search

A methodology for determining inorganic compounds present in particulate emissions from fossil fuel combustion processes is described. Samples collected from power plants burning oil and coal fuels of different composition provided a typical range of flyashes for the investigation. X-ray diffraction, Fourier transform infrared, and chemical-phase analyses were performed to determine elemental compositions of samples. Water-soluble sulfates are the predominant

William M. Henry; Kenneth T. Knapp

1980-01-01

51

Emission and deposition of Nitrogen compounds in West Africa  

NASA Astrophysics Data System (ADS)

The atmospheric nitrogen budget depends on emission and deposition fluxes both as reduced and oxidized compounds. In West African ecosystems, data are scarce, and establishing a N budget is not an easy task. This work aims at linking data from diverse origins (surface, aircraft measurements, satellite data, modelling) to estimate emissions and deposition of N compounds in dry and wet savannas of West Africa, and to study their impact on atmospheric chemistry. In remote areas like in the Sahel, N oxidised compounds emissions are dominated by NO biogenic emissions from soils. N emissions from anthropogenic sources (biomass burning, domestic fires, fossil fuel) are less important, due to the low quantity of vegetation, and to the remoteness of big cities. N reduced compounds emissions are dominated by the release of NH3 from cattle dung. Biogenic NO emissions from soils have a direct impact on NOx and O3 concentration increase in the lower troposphere, as shown by results from aircraft and surface measurements, and from modelling (coupled dynamics/chemistry MESONH-C model, with on line emission derived from a neural network algorithm, where the NO flux is dependent on water field pore space, surface and deep soil temperature, sand percentage, pH, fertilization rate and wind speed), in the area of Niamey (Niger) in August 2006. In a second part of this work, estimated emissions of both oxidised and reduced N compounds are compared to estimate dry and wet deposition fluxes for the year 2006 in the Sahel region. The dry deposition flux is the product of modelled dry deposition velocity and the measured concentration. Concentrations have been measured in 3 stations located in dry savanna ecosystem) within the IDAF (IGAC/DEBITS/Africa) network, and dry deposition velocities have been modelled with the surface model ISBA. A first tentative of budget has been calculated for the year 2006, trying to integrate all potentially known sources and sinks in the region. Finally, the study has been extended in time and space; emissions from soils and fires have been calculated for the years 2002 to 2007, dry deposition velocities have been calculated within the same period in the 3 stations of dry savanna, plus 2 stations in wet savanna. The results show that the interannual variability in rainfall is responsible for changes in emission (both biogenic and anthropogenic) and deposition (dry and wet) fluxes, due to changes in soil moisture and temperature, LAI, and turbulence, linked to meteorological conditions. This study uses original and unique data from remote and hardly-ever-explored regions. The main conclusion of this work is that while often underestimated, savannas and seasonally dry ecosystems of the African continent play a significant role in the global nitrogen budget, and have a direct impact on the chemistry of the troposphere.

Delon, C.; Galy-Lacaux, C.; Adon, M.; Liousse, C.

2010-12-01

52

75 FR 82363 - Approval and Promulgation of Implementation Plans; Ohio; Volatile Organic Compound Emission...  

Federal Register 2010, 2011, 2012, 2013

...Implementation Plans; Ohio; Volatile Organic Compound Emission Control Measures...and letterpress printing volatile organic compound (VOC) rule for approval into...with potential VOC ink oil emissions from the...

2010-12-30

53

A biogenic volatile organic compounds emission inventory for Yunnan Province.  

PubMed

The first detailed inventory for volatile organic compounds (VOC) emissions from vegetation over Yunnan Province, China was presented. The spatially and temporally resolved inventory was developed based on a geographic information system (GIS), remote sensing (RS) data and field measurement data, such as digitized land-use data, normalized difference vegetation index (NDVI) and temperature data from direct real-time measurement. The inventory has a spatial resolution of 5 km x 5 km and a time resolution of 1 h. Urban, agriculture, and natural land-use distributions in Yunnan Province were combined with biomass factors for each land-use category to produce a spatially resolved biomass inventory. A biogenic emission inventory was developed by combining the biomass inventory with hourly emission rates for tree, shrub and ground cover species of the study area. Correcting for environmental factors, including light intensity and temperature, a value of 1.1 x 10(12) gC for total annual biogenic VOC emissions from Yunnan Province, including 6.1 x 10(11) gC for isoprene, 2.1 x 10(11) gC for monoterpenes, and 2.6 x 10(11) gC for OVOC was obtained. The highest VOC emissions occurred in the northwestern, southwestern and north region of Yunnan Province. Some uncertainties were also discussed in this study. PMID:16083102

Wang, Zhi-Hui; Bai, Yu-Hua; Zhang, Shu-Yu

2005-01-01

54

Emission of volatile organic compounds from silage: Compounds, sources, and implications  

NASA Astrophysics Data System (ADS)

Silage, fermented cattle feed, has recently been identified as a significant source of volatile organic compounds (VOCs) to the atmosphere. A small number of studies have measured VOC emission from silage, but not enough is known about the processes involved to accurately quantify emission rates and identify practices that could reduce emissions. Through a literature review, we have focused on identifying the most important compounds emitted from corn silage (the most common type of silage in the US) and the sources of these compounds by quantifying their production and emission potential in silage and describing production pathways.We reviewed measurements of VOC emission from silage and assessed the importance of individual silage VOCs through a quantitative analysis of VOC concentrations within silage. Measurements of VOC emission from silage and VOCs present within silage indicated that alcohols generally make the largest contribution to emission from corn silage, in terms of mass emitted and potential ozone formation. Ethanol is the dominant alcohol in corn silage; excluding acids, it makes up more than half of the mean mass of VOCs present. Acids, primarily acetic acid, may be important when emission is high and all VOCs are nearly depleted by emission. Aldehydes and esters, which are more volatile than acids and alcohols, are important when exposure is short, limiting emission of more abundant but less volatile compounds.Variability in silage VOC concentrations is very high; for most alcohols and acids, tolerance intervals indicate that 25% of silages have concentrations a factor of two away from median values, and possibly much further. This observation suggests that management practices can significantly influence VOC concentrations. Variability also makes prediction of emissions difficult.The most important acids, alcohols, and aldehydes present in silage are probably produced by bacteria (and, in the case of ethanol, yeasts) during fermentation and storage of silage. Aldehydes may also be produced aerobically by spoilage microorganisms through the oxidation of alcohols. Abiotic reactions may be important for production of methanol and esters. Although silage additives appear to affect VOC production in individual studies, bacterial inoculants have not shown a consistent effect on ethanol, and effects on other VOCs have not been studied. Production of acetic acid is understood, and production could be minimized, but a decrease could lead to an increase in other, more volatile and more reactive, VOCs. Chemical additives designed for controlling yeasts and undesirable bacteria show promise for reducing ethanol production in corn silage.More work is needed to understand silage VOC production and emission from silage, including: additional measurements of VOC concentrations or production in silage of all types, and an exploration of the causes of variability; accurate on-farm measurements of VOC emission, including an assessment of the importance of individual ensiling stages and practices that could reduce emission of existing VOCs; and work on understanding the sources of silage VOCs and possible approaches for reducing production.

Hafner, Sasha D.; Howard, Cody; Muck, Richard E.; Franco, Roberta B.; Montes, Felipe; Green, Peter G.; Mitloehner, Frank; Trabue, Steven L.; Rotz, C. Alan

2013-10-01

55

Modeling Emissions of Volatile Organic Compounds from New Carpets  

SciTech Connect

A simple model is proposed to account for observed emissions of volatile organic compounds (VOCs) from new carpets. The model assumes that the VOCs originate predominantly in a uniform slab of polymer backing material. Parameters for the model (the initial concentration of a VOC in the polymer, a diffusion coefficient and an equilibrium polymer/air partition coefficient) are obtained from experimental data produced by a previous chamber study. The diffusion coefficients generally decrease as the molecular weight of the VOCs increase, while the polymer/air partition coefficients generally increase as the vapor pressure of the compounds decrease. In addition, for two of the study carpets that have a styrene-butadiene rubber (SBR) backing, the diffusion and partition coefficients are similar to independently reported values for SBR. The results suggest that predictions of VOCs emissions from new carpets may be possible based solely on a knowledge of the physical properties of the relevant compounds and the carpet backing material. However, a more rigorous validation of the model is desirable.

Little, J.C.; Hodgson, A.T.; Gadgil, A.J.

1993-02-01

56

A biogenic volatile organic compounds emission inventory for Beijing  

NASA Astrophysics Data System (ADS)

The present study presents us the first detailed inventory for volatile organic compounds (VOC) emissions from vegetation over Beijing, China. The spatially and temporally resolved inventory was developed based on a Geographic Information system (GIS), Remote sensing (RS) data and field measurement data, such as digitized land-use data, normalized difference vegetation index (NDVI) and temperature and photosynthetic active radiation (PAR) data from direct real-time measurement. The inventory has a spatial resolution of 1×1 km2 and a time resolution of 1 h. Urban, agriculture, and natural land-use distributions in Beijing were combined with biomass factors for each land-use category to produce a spatially resolved biomass inventory. A biogenic emission inventory was developed by combining the biomass inventory with hourly emission rates for tree, shrub, and ground cover species of the study area. Twenty-three kinds of the emission rate data of the 39 vegetation types in Beijing were identified using a bag-enclosure sampling method followed by GC-FID analysis in our field measurement. Other emission rate data were quoted from previous study or assigned with the taxonomic method. Correcting for environmental factors, including light intensity and temperature, we arrive a value of 1.6×10 10 g C for total annual biogenic VOC emissions from Beijing, including 7.9×10 9 g C for isoprene, 3.5×10 9 g C for monoterpenes, and 4.8×10 9 g C for OVOC. Some uncertainties are also discussed in this study.

Zhihui, Wang; Yuhua, Bai; Shuyu, Zhang

57

Emission of volatile organic compounds to the atmosphere in the solvent sublation process. II. Volatile chlorinated organic compounds  

SciTech Connect

The mass of trichloroethylene, chlorobenzene, and 1,3-dichlorobenzene removed from an aqueous solution and emitted to the atmosphere during solvent sublation was determined experimentally. It was shown that the emission of these compounds in solvent sublation was reduced by 30 to 85% over air stripping under the same experimental conditions. The efficiency of removal of these compounds from water was also studied. The reduction of emissions over air stripping was more effective for the more hydrophobic and less volatile compounds. Emissions are reduced as the thickness of organic layer on the top of the column is increased. The use of decyl alcohol as the layer compound decreases emissions to a greater extent than does paraffin oil. Removal of these chlorinated volatile organic compounds from water by solvent sublation at an elevated temperature of 45{degrees}C is significantly faster than at room temperature. However, the emissions to the atmosphere are also increased.

Ososkov, V.; Kebbekus, B.; Chou, C.C. [New Jersey Inst. of Technology, Newark, NJ (United States)

1996-06-01

58

40 CFR 60.502 - Standard for Volatile Organic Compound (VOC) emissions from bulk gasoline terminals.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Standard for Volatile Organic Compound (VOC) emissions from bulk gasoline...Terminals § 60.502 Standard for Volatile Organic Compound (VOC) emissions from bulk gasoline...collection system designed to collect the total organic compounds vapors displaced from tank...

2013-07-01

59

Identification of nonmethane organic compound emissions from grassland vegetation.  

SciTech Connect

Emissions of nonmethane organic compounds (NMOCs) from grassland vegetation were collected in Summa(reg.sign) passivated stainless-steel canisters with a static enclosure technique and were analyzed by high-resolution gas chromatography with flame ionization and ion trap mass spectrometric detectors. Approximately 40 NMOCs with 6-10 carbon atoms were observed in samples analyzed by high-resolution gas chromatography with the flame ionization detector. Nineteen NMOCs in this molecular weight range (6 aliphatic oxygenates; 1 aromatic hydrocarbon; and 4 acyclic, 5 monocyclic, and 3 bicyclic monoterpenoids) were identified by ion trap mass spectrometry. Mass spectrometry was particularly useful for identifying myrcene and cis-3-hexenylacetate, which coeluted on a fused-silica capillary column coated with a 1-{mu}m-thick film of polydimethylsiloxane. An evaluation of the reactivity of the grassland emissions revealed that the aliphatic oxygenates have lifetimes of a few hours with respect to oxidation by OH and O{sub 3} in the atmosphere. This value is similar to the lifetimes of the bicyclic monoterpenoids. The expected lifetimes of the monoterpenoids with respect to oxidation by NO{sub 3} are only several minutes.

Fukui, Y.; Doskey, P. V.; Environmental Research; NASA Ames Research Center

2000-01-01

60

Emissions of Volatile and Potentially Toxic Organic Compounds from Sewage Treatment Plants and Collection Systems.  

National Technical Information Service (NTIS)

Publicly-owned treatment works (POTWs) are a source of potentially toxic organic compound (PTOC) emissions for which limited data are available. The study assesses the potential for PTOC emissions from municipal wastewater treatment plants (MWTPs) and col...

D. P. Y. Chang E. D. Schroeder R. L. Corsi

1987-01-01

61

CONTROL OF INDUSTRIAL VOC (VOLATILE ORGANIC COMPOUND) EMISSIONS BY CATALYTIC INCINERATION. VOLUME 9. QUALITY ASSURANCE  

EPA Science Inventory

Radian Corporation, under contract to the U.S. Environmental Protection Agency, performed site selection, test plan development, and performance tests of catalytic incinerators used for volatile organic compound (VOC) emissions control at industrial sites. VOC emissions are of co...

62

78 FR 24990 - Approval and Promulgation of Implementation Plans; Ohio; Volatile Organic Compound Emission...  

Federal Register 2010, 2011, 2012, 2013

...Implementation Plans; Ohio; Volatile Organic Compound Emission Control Measures for...Implementation Plan (SIP), several volatile organic compound (VOC) rules that were submitted...stationary sources, storage of volatile organic liquids, industrial cleaning...

2013-04-29

63

FACTORS CONTROLLING THE EMISSIONS OF MONOTERPENES AND OTHER VOLATILE ORGANIC COMPOUNDS  

EPA Science Inventory

Plants contain a number of volatile organic compounds, including isoprene, mono- and sesquiterpenes, alcohols, aldehydes, ketones, and esters. ndividual plant species have unique combinations of these compounds; consequently, the emission pattern for each species is also specific...

64

Non-Methane Volatile Organic Compound Measurements in the City Centre of Wroclaw, Poland  

Microsoft Academic Search

During the measurement campaign performed in August\\/ September 2005 non-methane volatile organic compounds (NMVOCs) were studied\\u000a at different locations in the city of Wroclaw, Poland. The measurements covered NMVOCs in the range of C1-C10. Samples were collected using Carbotrap and Carbosieve SIII solid adsorption tubes and analysed off-line by thermal desorption\\u000a and GC-FID analysis. Measurements were performed on purpose to

A. Niedojadlo; K. H. BECKER; Y. Elshorbany; R. Kurtenbach; P. Wiesen; A. Schady; A. Zwozdziak; J. Zwozdziak

65

Modeling of Global Biogenic Emissions for Key Indirect Greenhouse Gases (Invited)  

NASA Astrophysics Data System (ADS)

One key element of assessing the impact of human activities on climate change is to accurately estimate the emissions of not only direct but also indirect (reactive) greenhouse gases (GHGs). Direct GHGs, e.g. carbon dioxide (CO2), methane (CH4), and ozone (O3), can warm up the Earths surface by absorbing the terrestrial infrared (IR) radiation. Reactive gases, e.g. carbon monoxide (CO), nitric oxides (NOx), and non-methane volatile organic compounds (NMVOCs), though transparent to IR radiation, can impact the climate system by altering CH4 and tropospheric O3 concentrations, two important GHGs, through complex chemical processes. In this study, we integrated a biogenic model within a terrestrial ecosystem model to investigate the vegetation and soil emissions of key indirect GHGs, e.g., isoprene, monoterpene, other NMVOCs (OVOC), CO, and NOx. The combination of a high-resolution terrestrial ecosystem model with satellite data allows investigation of the potential changes in biogenic emissions of indirect GHGs due to atmospheric CO2 increases, and changes in climate and land-use practices.

Jain, A.; Yang, X.

2009-12-01

66

Predicting the emission rate of volatile organic compounds fromvinyl flooring  

SciTech Connect

A model for predicting the rate at which a volatile organic compound (VOC) is emitted from a diffusion-controlled material is validated for three contaminants (n-pentadecane, n-tetradecane, and phenol) found in vinyl flooring (VF). Model parameters are the initial VOC concentration in the material-phase (C{sub 0}), the material/air partition coefficient (K), and the material-phase diffusion coefficient (D). The model was verified by comparing predicted gas-phase concentrations to data obtained during small-scale chamber tests, and by comparing predicted material-phase concentrations to those measured at the conclusion of the chamber tests. Chamber tests were conducted with the VF placed top side up and bottom side up. With the exception of phenol, and within the limits of experimental precision, the mass of VOCs recovered in the gas phase balances the mass emitted from the material phase. The model parameters (C{sub 0}, K, and D) were measured using procedures that were completely independent of the chamber test. Gas- and material-phase predictions compare well to the bottom-side-up chamber data. The lower emission rates for the top-side-up orientation may be explained by the presence of a low-permeability surface layer. The sink effect of the stainless steel chamber surface was shown to be negligible.

Cox, Steven S.; Little, John C.; Hodgson, Alfred T.

2001-03-01

67

[Assessment of the emission of volatile organic compounds from polyurethane foams].  

PubMed

The emission of 2,4- and 2,6-diaminotoluene, triethylenediamine, diethanolamine and other volatile organic compounds from polyurethane foams was examined in environmental chamber. Tested materials did not release of amines. The emission of total volatile organic compounds showed differences for polyurethane samples but did not exceed ecological standards. PMID:15493351

Pecka, Irena; Wiglusz, Renata; Sitko, Elzbieta; Nikel, Grazyna

2004-01-01

68

Guideline series: Control of volatile organic compound emissions from offset lithographic printing. Draft report  

SciTech Connect

The report is a draft control techniques guideline (CTG) document for control of volatile organic compound emissions from offset lithographic printing. The document address sheet fed, non-heatset web, newspapers, and heat-set web offset lithographic printing. The principle emission sources addressed are fountain solution, cleaning solvents (blanket and roller washes) and heatset dryers. The purpose of a CTG document is to assist state and local air pollution agencies in developing regulations to limit emissions of volatile organic compounds.

NONE

1993-09-01

69

Acoustic emission behavior during tensile deformation of Ni 3Al intermetallic compound  

Microsoft Academic Search

Acoustic emission behavior during tensile deformation of single crystals and unidirectionally solidified specimens of Ni3Al intermetallic compound was studied. Mobile dislocation behavior in single crystals was investigated by measuring acoustic emission rms voltage. Using unidirectionally solidified specimens, effects of grain boundaries parallel to tensile axis on the acoustic emission behavior during tensile deformation of Ni3Al was examined. It was made

K. Yoshida; T. Saito; A. Zhu; H. Takagi; K. Sakamaki

1998-01-01

70

Determination of volatile organic compounds in emissions by coal-fired power stations from Spain.  

PubMed

This study concerns the emissions of volatile organic compounds (VOCs) by coal fired power stations. The main compounds are monoaromatic hydrocarbons and aliphatic hydrocarbons, chlorinated compounds have less importance. The influence of combustion parameters can not be clearly established. Emissions factors were calculated and they are smaller than those of other anthropogenic combustions. A comparative study of two sources of VOCs, power stations and motor vehicles, indicates that the environmental impact of the latter are most important. PMID:11424734

Fernández-Martínez, G; López-Vilariño, J M; López-Mahía, P; Muniategui-Lorenzo, S; Prada-Rodríguez, D; Fernández-Fernández, E

2001-05-01

71

Global emissions and models of photochemically active compounds  

SciTech Connect

Anthropogenic emissions from industrial activity, fossil fuel combustion, and biomass burning are now known to be large enough (relative to natural sources) to perturb the chemistry of vast regions of the troposphere. A goal of the IGAC Global Emissions Inventory Activity (GEIA) is to provide authoritative and reliable emissions inventories on a 1{degree} {times} 1{degree} grid. When combined with atmospheric photochemical models, these high quality emissions inventories may be used to predict the concentrations of major photochemical products. Comparison of model results with measurements of pertinent species allows us to understand whether there are major shortcomings in our understanding of tropospheric photochemistry, the budgets and transport of trace species, and their effects in the atmosphere. Through this activity, we are building the capability to make confident predictions of the future consequences of anthropogenic emissions. This paper compares IGAC recommended emissions inventories for reactive nitrogen and sulfur dioxide to those that have been in use previously. We also present results from the three-dimensional LLNL atmospheric chemistry model that show how emissions of anthropogenic nitrogen oxides might potentially affect tropospheric ozone and OH concentrations and how emissions of anthropogenic sulfur increase sulfate aerosol loadings.

Penner, J.E.; Atherton, C.S. [Lawrence Livermore National Lab., CA (United States); Graedel, T.E. [AT and T Bell Labs., Murray Hill, NJ (United States)

1993-05-20

72

MEASUREMENT OF ORGANIC COMPOUND EMISSIONS USING SMALL TEST CHAMBERS  

EPA Science Inventory

The paper discusses the measurement of organic emissions from a variety of indoor materials, using small (166 liter) environmental test chambers. he following materials were tested: adhesives, caulks, pressed wood products, floor waxes, paints, and solid insecticides. or each mat...

73

[Application of mathematical models for determination of volatile organic compounds emission from flooring adhesives].  

PubMed

An environmental chamber with controlled temperature, relative humidity, and air exchange was used to evaluate emissions of volatile organic compounds (VOC) from three flooring solvent-based adhesives. Gas chromatograph equipped with flame ionization detector was employed to measure VOC emission. The temporal change in concentration of VOC emitted from each adhesive was observed and double-exponential model was compared with a first-order emission decay model in their ability to describe measured emission factors of adhesives. It was demonstrated that the double exponential model better describes emission characteristic for experimental data than first-order model does. PMID:16610675

Wiglusz, Renata; Sitko, Elzbieta; Pecka, Irena; Nikel, Grazyna

2005-01-01

74

Characterizing biogenic emissions of sesquiterpene and oxygenated terpene compounds  

NASA Astrophysics Data System (ADS)

Evidence for very reactive biogenic VOCs (BVOCs) has been observed at Blodgett Forest, a coniferous forest in the Sierra Nevada Mountains of California. The evidence has included chemical ozone loss in the forest canopy and the presence of BVOC oxidation products in and above the canopy. To measure emission rates of these reactive BVOCs, we placed enclosures over branches of the dominant species at the site Ponderosa pine, ceanothus, and manzanita in the summer of 2005. Zero air, with ambient CO2 concentrations, flowed through the chamber system and VOC emission measurements were made by proton transfer reaction mass spectrometry (PTR-MS), solid phase microextraction (SPME) on fibers followed by direct injection into a gas chromatograph with an ion trap mass spectrometer (GC-ITMS), and by in-situ GC with a flame ionization detector (GC-FID). Multiple studies have characterized oxygenated BVOC and monoterpene emissions at this site; here we focus on the identification and quantification of sesquiterpene and oxygenated terpene emissions. We report emission profiles over the three month sampling period. We also assess the relative importance of these terpenes for chemistry in the canopy and secondary organic aerosol (SOA) formation.

Bouvier-Brown, N. C.; Holzinger, R.; Palitzsch, K.; Goldstein, A. H.

2006-12-01

75

HISTORIC EMISSIONS OF VOLATILE ORGANIC COMPOUNDS IN THE UNITED STATES FROM 1900 TO 1985  

EPA Science Inventory

The report gives an estimate of historic emissions of volatile organic compounds (VOCs) for each state (and the District of Columbia) of the contiguous U.S. Annual emissions were estimated on the national level from 1960 to 1985. For 1940, 1950, and every fifth year from 1960 to ...

76

Diffusion-controlled reference material for volatile organic compound emissions testing: Pilot inter-laboratory study  

Microsoft Academic Search

To improve the reliability and accuracy of tests used to measure emissions of volatile organic compounds (VOCs) from samples of interior building products, the National Institute of Standards and Technology (NIST) and Virginia Tech (VT) have created a program to develop reference materials with independently predictable emission rates. A diffusive reference material and associated mechanistic model have been developed and

Cynthia Howard-Reed; Zhe Liu; Jennifer Benning; Steven Cox; Daniel Samarov; Dennis Leber; Alfred T. Hodgson; Stephany Mason; Doyun Won; John C. Little

2011-01-01

77

Patterns in volatile organic compound emissions along a savanna-rainforest gradient in central Africa  

Microsoft Academic Search

In temperate regions the chemistry of the lower troposphere is known to be significantly affected by biogenic volatile organic compounds (VOCs) emitted by plants. The chemistry of the lower troposphere over the tropics, however, is poorly understood, in part because of the considerable uncertainties in VOC emissions from tropical ecosystems. Present global VOC models predict that base emissions of isoprene

L. F. Klinger; J. Greenberg; A. Guenther; G. Tyndall; P. Zimmerman; J.-M. Moutsamboté; D. Kenfack

1998-01-01

78

An Estimate of Biogenic Emissions of Volatile Organic Compounds during Summertime in China (7 pp)  

Microsoft Academic Search

Background  and Aim. An accurate estimation of biogenic emissions of VOC (volatile organic compounds) is necessary for better understanding\\u000a a series of current environmental problems such as summertime smog and global climate change. However, very limited studies\\u000a have been reported on such emissions in China. The aim of this paper is to present an estimate of biogenic VOC emissions during\\u000a summertime

Almut Heinrich; Zhiwei Han; Tijian Wang; Yoshiro Higano

2007-01-01

79

Speciation of volatile organic compound emissions for regional air quality modeling of particulate matter and ozone  

NASA Astrophysics Data System (ADS)

A new classification scheme for the speciation of organic compound emissions for use in air quality models is described. The scheme uses 81 organic compound classes to preserve both net gas-phase reactivity and particulate matter (PM) formation potential. Chemical structure, vapor pressure, hydroxyl radical (OH) reactivity, freezing point/boiling point, and solubility data were used to create the 81 compound classes. Volatile, semivolatile, and nonvolatile organic compounds are included. The new classification scheme has been used in conjunction with the Canadian Emissions Processing System (CEPS) to process 1990 gas-phase and particle-phase organic compound emissions data for summer and winter conditions for a domain covering much of eastern North America. A simple postprocessing model was used to analyze the speciated organic emissions in terms of both gas-phase reactivity and potential to form organic PM. Previously unresolved compound classes that may have a significant impact on ozone formation include biogenic high-reactivity esters and internal C6-8 alkene-alcohols and anthropogenic ethanol and propanol. Organic radical production associated with anthropogenic organic compound emissions may be 1 or more orders of magnitude more important than biogenic-associated production in northern United States and Canadian cities, and a factor of 3 more important in southern U.S. cities. Previously unresolved organic compound classes such as low vapour pressure PAHs, anthropogenic diacids, dialkyl phthalates, and high carbon number alkanes may have a significant impact on organic particle formation. Primary organic particles (poorly characterized in national emissions databases) dominate total organic particle concentrations, followed by secondary formation and primary gas-particle partitioning. The influence of the assumed initial aerosol water concentration on subsequent thermodynamic calculations suggests that hydrophobic and hydrophilic compounds may form external mixtures, and that separate treatment for these groups may be required in future air quality model simulations. The post-processing model used here overestimates the organic particle formation relative to measurements, lacks the complexity of a regional air quality model, and is not intended as an alternative to the latter. Results from the post-processing model do, however, provide guidance for the treatment of organic gases and particles in future air quality modeling work. Future air quality model simulations should attempt to speciate primary particulate organic compounds and include more detailed organic compound classes. Future emissions profile measurements should speciate gaseous high-molecular-mass organic compounds and primary organics emitted in particulate form (primary particle emissions are only available as a total particulate mass in currently available emissions data).

Makar, P. A.; Moran, M. D.; Scholtz, M. T.; Taylor, A.

2003-01-01

80

Emission of charged particles from excited compound nuclei  

SciTech Connect

The process of complex fragment emission is studied within the dinuclear system model. Cross sections of complex fragment emission are calculated and compared with experimental data for the reactions {sup 3}He+{sup nat}Ag, {sup 78,86}Kr+{sup 12}C, and {sup 63}Cu+{sup 12}C. The mass distributions of the products of these reactions, isotopic distributions for the {sup 3}He+{sup nat}Ag and {sup 78}Kr+{sup 12}C reactions, and average total kinetic energies of the products of the {sup 78}Kr+{sup 12}C reaction are predicted.

Kalandarov, Sh. A.; Adamian, G. G. [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna, RU-141980 Moscow (Russian Federation); Institute of Nuclear Physics, Tashkent, UZ-702132 Tashkent (Uzbekistan); Antonenko, N. V. [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna, RU-141980 Moscow (Russian Federation); Scheid, W. [Institut fuer Theoretische Physik der Justus-Liebig-Universitaet, D-35392 Giessen (Germany)

2010-10-15

81

Emissions of volatile organic compounds from vegetation and the implications for atmospheric chemistry  

Microsoft Academic Search

Vegetation provides a major source of reactive carbon entering the atmosphere. These compounds play an important role in (1) shaping global tropospheric chemistry, (2) regional photochemical oxidant formation, (3) balancing the global carbon cycle, and (4) production of organic acids which contribute to acidic deposition in rural areas. Present estimates place the total annual global emission of these compounds between

Fred Fehsenfeld; Jack Calvert; Ray Fall; Paul Goldan; A. B. Guenther; C. N. Hewitt; Brian Lamb; Shaw Liu; Michael Trainer; Hal Westberg; Pat Zimmerman

1992-01-01

82

Emissions of Some Organochlorine Compounds in Experimental Aluminum Degassing with Hexachloroethane  

Microsoft Academic Search

Degassing agents based on hexachloroethane (HCE) are used to remove hydrogen gas from molten aluminum, particularly in foundries and remelting plants. Previously considered fairly innocuous, recent studies of the emissions from this process have shown high yields of some toxic organochlorine compounds. To determine a wider spectrum of such compounds, a series of experimental degassings was carried out in a

Håkan B. Westberg; Anders I. Seldén; Tom Bellander

1997-01-01

83

Characterizing biogenic emissions of sesquiterpene and oxygenated terpene compounds  

Microsoft Academic Search

Evidence for very reactive biogenic VOCs (BVOCs) has been observed at Blodgett Forest, a coniferous forest in the Sierra Nevada Mountains of California. The evidence has included chemical ozone loss in the forest canopy and the presence of BVOC oxidation products in and above the canopy. To measure emission rates of these reactive BVOCs, we placed enclosures over branches of

N. C. Bouvier-Brown; R. Holzinger; K. Palitzsch; A. H. Goldstein

2006-01-01

84

The impact of air pollutant and methane emission controls on tropospheric ozone and radiative forcing: CTM calculations for the period 1990-2030  

NASA Astrophysics Data System (ADS)

To explore the relationship between tropospheric ozone and radiative forcing with changing emissions, we compiled two sets of global scenarios for the emissions of the ozone precursors methane (CH4), carbon monoxide (CO), non-methane volatile organic compounds (NMVOC) and nitrogen oxides (NOx) up to the year 2030 and implemented them in two global Chemistry Transport Models. The "Current Legislation" (CLE) scenario reflects the current perspectives of individual countries on future economic development and takes the anticipated effects of presently decided emission control legislation in the individual countries into account. In addition, we developed a "Maximum technically Feasible Reduction" (MFR) scenario that outlines the scope for emission reductions offered by full implementation of the presently available emission control technologies, while maintaining the projected levels of anthropogenic activities. Whereas the resulting projections of methane emissions lie within the range suggested by other greenhouse gas projections, the recent pollution control legislation of many Asian countries, requiring introduction of catalytic converters for vehicles, leads to significantly lower growth in emissions of the air pollutants NOx, NMVOC and CO than was suggested by the widely used IPCC (Intergovernmental Panel on Climate Change) SRES (Special Report on Emission Scenarios) scenarios (Nakicenovic et al., 2000). With the TM3 and STOCHEM models we performed several long-term integrations (1990-2030) to assess global, hemispheric and regional changes in CH4, CO, hydroxyl radicals, ozone and the radiative climate forcings resulting from these two emission scenarios. Both models reproduce realistically the observed trends in background ozone, CO, and CH4 concentrations from 1990 to 2002. For the "current legislation" case, both models indicate an increase of the annual average ozone levels in the Northern hemisphere by 5 ppbv, and up to 15 ppbv over the Indian sub-continent, comparing the 2020s with the 1990s. The corresponding higher ozone and methane burdens in the atmosphere increase radiative forcing by approximately 0.2 Wm-2. Full application of today's emissions control technologies, however, would bring down ozone below the levels experienced in the 1990s and would reduce the current radiative forcing of ozone and methane by approximately 0.1Wm-2. While methane reductions lead to lower ozone burdens and to less radiative forcing, further reductions of the air pollutants NO4 and NMVOC result in lower ozone, but at the same time increase the lifetime of methane. Control of methane emissions appears an efficient option to reduce tropospheric ozone as well as radiative forcing.

Dentener, F.; Stevenson, D.; Cofala, J.; Mechler, R.; Amann, M.; Bergamaschi, P.; Raes, F.; Derwent, R.

2004-12-01

85

MEASUREMENT OF ORGANIC COMPOUND EMISSIONS USING SMALL TEST CHAMBERS  

EPA Science Inventory

Organic compounds emitted from a variety of indoor materials have been measured using small (166 L) environmental test chambers. The paper discusses: a) factors to be considered in small chamber testing; b) parameters to be controlled; c) the types of results obtained. The follow...

86

Modeling emissions of volatile organic compounds from silage  

Technology Transfer Automated Retrieval System (TEKTRAN)

Volatile organic compounds (VOCs), necessary reactants for photochemical smog formation, are emitted from numerous sources. Limited available data suggest that dairy farms emit VOCs with cattle feed, primarily silage, being the primary source. Process-based models of VOC transfer within and from si...

87

Emission and Chemical Transformation of Biogenic Volatile Organic Compounds (echo)  

Microsoft Academic Search

Forests are complex sources of biogenic volatile organic compounds (VOC) in the planetary boundary layer. The impact of biogenic VOC on tropospheric photochem- istry, air quality, and the formation of secondary products affects our climate on a regional and global scale but is far from being understood. A considerable lack of knowledge exists concerning a forest stand as a net

R. Koppmann; T. Hoffmann; J. Kesselmeier; M. Schatzmann

2002-01-01

88

Electron Emission Studies of the IIB-VIA Semiconductor Compounds.  

National Technical Information Service (NTIS)

X-ray induced electron emission measurements were used to determine the energy levels of core electrons in ZnO, ZnS, ZnSe, ZnTe, CdO, CdS, CdSe, CdTe, HgS, HgSe and HgTe. The investigated energy range extends from the bottom of the valence band (6-8 eV be...

C. J. Vesely

1971-01-01

89

Interannual variability of Nitrogen compounds emission and deposition in West and Central Africa  

NASA Astrophysics Data System (ADS)

The atmospheric nitrogen budget depends on emission and deposition fluxes both as reduced and oxidized compounds. In this study, a first attempt at estimating the interannual variability of the nitrogen emission and deposition fluxes for the years 2002 to 2007 is made, through measurements and simulations at seven stations of the IDAF (IGAC-DEBITS-Africa) network situated in dry savanna, wet savanna and forest ecosystems. The purpose of this study is to estimate the impact of the interannual variability in precipitations on the interannual variability in emission and deposition of nitrogen compounds. The interannual variability of rains between 2002 and 2007 is responsible for changes in emission and deposition fluxes, due to changes in soil moisture and temperature, LAI, and turbulence, linked to meteorological conditions. Dry and wet deposition fluxes are presented in a companion paper (Adon et al., this session) They are calculated from measurements of NO2, HNO3 and NH3 concentrations (from passive samplers) and simulated deposition velocities, and wet deposition is calculated from NH4+ and NO3- concentration in samples of rain. This budget does not take into account organic nitrogen species. Emission fluxes are evaluated including NO biogenic emission from soils, emissions of NOx and NH3 from domestic and biomass fires, and volatilization of NH3 from animal excreta. Biogenic NO fluxes from soils are simulated in a SVAT model (ISBA), where an algorithm derived from an Artificial Neural Network has been inserted. Meteorological conditions are provided by the forcing, derived from satellite data, and developed in ALMIP (AMMA Land surface Model Intercomparison Project). Emissions of NOx and NH3 from domestic fires and biomass burning are calculated from satellite data, and volatilization of NH3 is calculated from the release of N input from animal excreta, and from the animal population in each country. This study uses original and unique data from remote and hardly-ever-explored regions. In dry savanna ecosystems, the monthly evolution of oxidized N compounds shows that the fluxes increase at the beginning of the rainy season, because of large emissions of biogenic NO (pulse events). Emission of oxidized compounds is dominated by biogenic emission from soils in dry savanna ecosystems, whereas domestic fires and biomass burning emission of oxidized compounds are more important in wet savanna and forest sites. In dry savannas, emission of NH3 is dominated by the process of volatilization from animal excreta, whereas it is dominated by emissions from domestic fires and biomass burning in wet savanna and forests.

Delon, Claire; Galy-Lacaux, Corinne; Adon, Marcellin; Liousse, Cathy; Boone, Aaron; Serça, Dominique

2010-05-01

90

Evaluating the performance of pyrogenic and biogenic emission inventories against one decade of space-based formaldehyde columns  

NASA Astrophysics Data System (ADS)

A new one-decade dataset of formaldehyde (HCHO) columns retrieved from GOME and SCIAMACHY is compared with HCHO columns simulated by an updated version of the IMAGES global chemical transport model. This model version includes an optimized chemical scheme with respect to HCHO production, where the short-term and final HCHO yields from pyrogenically emitted non-methane volatile organic compounds (NMVOCs) are estimated from the Master Chemical Mechanism (MCM) and an explicit speciation profile of pyrogenic emissions. The model is driven by the Global Fire Emissions Database (GFED) version 1 or 2 for biomass burning, whereas biogenic emissions are provided either by the Global Emissions Inventory Activity (GEIA), or by a newly developed inventory based on the Model of Emissions of Gases and Aerosols from Nature (MEGAN) algorithms driven by meteorological fields from the European Centre for Medium-Range Weather Forecasts (ECMWF). The comparisons focus on tropical ecosystems, North America and China, which experience strong biogenic and biomass burning NMVOC emissions reflected in the enhanced measured HCHO columns. These comparisons aim at testing the ability of the model to reproduce the observed features of the HCHO distribution on the global scale and at providing a first assessment of the performance of the current emission inventories. The high correlation coefficients (r>0.8) between the observed and simulated columns over most regions indicate a very good consistency between the model, the implemented inventories and the HCHO dataset. The use of the MEGAN-ECMWF inventory improves the model/data agreement in almost all regions, but biases persist over parts of Africa and the Northern Australia. Although neither GFED version is consistent with the data over all regions, a better match is achieved over Indonesia and Southern Africa when GFEDv2 is used, but GFEDv1 succeeds better in getting the correct seasonal patterns and intensities of the fire episodes over the Amazon basin, as reflected by the higher correlations calculated in this region.

Stavrakou, T.; Müller, J.-F.; de Smedt, I.; van Roozendael, M.; van der Werf, G. R.; Giglio, L.; Guenther, A.

2008-09-01

91

Carbonyl compounds and PAH emissions from CNG heavy-duty engine  

SciTech Connect

Previous works carried out in Istituto Motori laboratories have shown that natural gas is a suitable fuel for general means of transportation. This is because of its favorable effects on engine performance and pollutant emissions. The natural gas fueled engine provided the same performance as the diesel engine, met R49 emission standards, and showed very low smoke levels. On the other hand, it is well known that internal combustion engines emit some components that are harmful for human health, such as carbonyl compounds and polycyclic aromatic hydrocarbons (PAH). This paper shows the results of carbonyl compounds and PAH emissions analysis for a heavy-duty Otto cycle engine fueled with natural gas. The engine was tested using the R49 cycle that is used to measure the regulated emissions. The test analysis has been compared with an analysis of a diesel engine, tested under the same conditions. Total PAH emissions from the CNG engine were about three orders of magnitude lower than from the diesel engine. Formaldehyde emission from the CNG engine was about ten times as much as from the diesel engine, while emissions of other carbonyl compounds were comparable.

Gambino, M.; Cericola, R.; Corbo, P.; Iannaccone, S. (Istituto Motori C.N.R., Naples (Italy))

1993-10-01

92

Estimation of biogenic volatile organic compounds emissions in subtropical island--Taiwan.  

PubMed

Elevated tropospheric ozone is harmful to human health and plants. It is formed through the photochemical reactions involving volatile organic compounds (VOCs) and nitrogen oxides (NO(x)). The elevated ozone episodes occur mainly in summer months in the United States, while the high-ozone episodes frequently occur during the fall in Taiwan. The unique landscape of Taiwan produces tremendous amounts of biogenic VOCs in the mountain regions that are adjacent to concentrated urban areas. The urban areas, in turn, generate prodigious amounts of anthropogenic emissions. Biogenic VOC emissions have direct influence on tropospheric ozone formation. To explore the air quality problems in Taiwan, this study attempts to develop a biogenic VOC emission model suitable for air quality applications in Taiwan. The emission model is based on the Biogenic Emissions Inventory System Version 2 and coupled with a detailed Taiwan land use database. The 1999 total Taiwan biogenic VOC emissions were estimated at 214,000 metric tons. The emissions of isoprene, monoterpenes, and other VOCs were about 37.2%, 30.4%, and 32.4% of total biogenic VOC emissions, respectively. The annual total biogenic VOC emission per unit area was more than two times the value of that in any European country, implying that detailed emissions estimates in any size of region will benefit the global biogenic emission inventories. PMID:15993693

Chang, Ken-Hui; Chen, Tu-Fu; Huang, Ho-Chun

2005-01-07

93

Emission estimates of selected volatile organic compounds from tropical savanna burning in northern Australia  

NASA Astrophysics Data System (ADS)

Here we present measurements of a range of carbon-based compounds: carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), nonmethane hydrocarbons (NMHCs), methyl halides, and dimethyl sulfide (DMS) emitted by Australian savanna fires studied as part of the Biomass Burning and Lightning Experiment (BIBLE) phase B aircraft campaign, which took place during the local late dry season (28 August to 13 September 1999). Significant enhancements of short-lived NMHCs were observed in the boundary layer (BL) over the region of intensive fires and indicate recent emissions for which the mean transport time was estimated to be about 9 hours. Emission ratios relative to CO were determined for 20 NMHCs, 3 methyl halides, DMS, and CH4 based on the BL enhancements in the source region. Tight correlations with CO were obtained for most of those compounds, indicating the homogeneity of the local savanna source. The emission ratios were in good agreement with some previous measurements of savanna fires for stable compounds but indicated the decay of emission ratios during transport for several reactive compounds. Based on the observed emission ratios, emission factors were derived and compared to previous studies. While emission factors (g species/kg dry mole) of CO2 varied little according to the vegetation types, those of CO and NMHCs varied significantly. Higher combustion efficiency and a lower emission factor for methane in this study, compared to forest fires, agreed well with results for savanna fires in other tropical regions. The amount of biomass burned was estimated by modeling methods using available satellite data, and showed that 1999 was an above average year for savanna burning. The gross emissions of the trace gases from Australian savanna fires were estimated.

Shirai, T.; Blake, D. R.; Meinardi, S.; Rowland, F. S.; Russell-Smith, J.; Edwards, A.; Kondo, Y.; Koike, M.; Kita, K.; Machida, T.; Takegawa, N.; Nishi, N.; Kawakami, S.; Ogawa, T.

2003-02-01

94

Membrane bioreactor for control of volatile organic compound emissions  

SciTech Connect

A membrane bioreactor system that overcomes many of the limitations of conventional compost biofilters is described. The system utilizes microporous hydrophobic hollow fiber membranes for mass transfer of volatile organic compounds (VOCs) from the gas phase to a microbially active liquid phase. The reactor design provides a high biomass concentration, a method for wasting biomass, and a method for addition of pH buffers, nutrients, cometabolites, and/or other amendments. A theoretical model is developed, describing mass transfer and biodegradation in the membrane bioreactor. Reactor performance was determined in a laboratory scale membrane bioreactor over a range of gas loading rates using toluene as a model VOC. Toluene removal efficiency was greater than 98% at an inlet concentration of 100 ppm, and a gas residence time of less than 2 s. Factors controlling bioreactor performance were determined through both experiments and theoretical modeling to include: compound Henry`s law constant, membrane specific surface area, gas and VOC loading rates, liquid phase turbulence, and biomass substrate utilization rate.

Ergas, S.J. [Univ. of Massachusetts, Amherst, MA (United States). Dept. of Civil and Environmental Engineering; McGrath, M.S. [Monsanto Enviro-Chem Systems Inc., Chesterfield, MO (United States)

1997-06-01

95

Variation among different genotypes of hybrid poplar with regard to leaf volatile organic compound emissions.  

PubMed

Plantations of hybrid poplar are used in temperate regions to produce woody biomass for forestry-related industries and are likely to become more prevalent if they are used as a source of cellulose for second-generation biofuels. Species in the genus Populus are known to emit great quantities of the volatile organic compounds (VOCs) isoprene and methanol, and lesser quantities of terpene VOCs, giving poplar plantations the potential to significantly influence regional atmospheric chemistry. The goals of this study were to quantify the differences in isoprene, methanol, and monoterpene emissions from 30 hybrid poplar genotypes, determine how well VOC emissions could be explained by growth, photosynthesis, and stomatal conductance, determine whether the parental crosses that created a genotype could be used to predict its emissions, and determine whether VOC emissions from different genotypes exhibit different responses to elevated CO2. We found that 40-50% of the variation in isoprene emissions across genotypes could be explained by a combination of instantaneous photosynthesis rate and seasonal aboveground growth and 30-35% of methanol emissions could be explained by stomatal conductance. We observed a threefold range in isoprene emissions across all 30 genotypes. Both genotype and parental cross were significant predictors of isoprene and monoterpene emissions. Genotypes from P. tricocarpa X P. deltoides (T x D) crosses generally had higher isoprene emissions and lower monoterpene emissions than those from P. deltoides x P. nigra (D x N) crosses. While isoprene and monoterpene emissions generally decreased under elevated CO2 and methanol emissions generally increased, the responses varied among genotypes. Our findings suggest that genotypes with greater productivity tend to have higher isoprene emissions. Additionally, the genotypes with the lowest isoprene emissions under current CO2 are not necessarily the ones with the lowest emissions under elevated CO2. PMID:23210305

Eller, Allyson S D; de Gouw, Joost; Graus, Martin; Monson, Russell K

2012-10-01

96

Emissions of Nonmethane Organic Compounds at an Illinois (USA) Landfill: Preliminary Field Measurements  

SciTech Connect

Current US regulatory models for estimating emissions of nonmethane organic compounds (NMOCs) from municipal solid waste (MSW) landfills require field validation to determine if the models are realistic. A project was initiated to begin to develop a field method for direct measurement of landfill NMOC emissions and, concurrently, develop improved sampling and analysis methods for individual NMOCs in landfill gas matrices. Two contrasting field sites at the Greene Valley Landfill, DuPage County, Illinois, USA, were established.

Bogner, J.; Spokas, K. [Argonne National Lab., IL (United States); Niemann, M.; Niemann, L. [Rust Environment and Infrastructure, Oak Brook, IL (United States); Baker, J. [WMX Technology Center, Geneva, IL (United States)

1997-08-01

97

Volatile organic compound emissions from usaf wastewater treatment plants in ozone nonattainment areas. Master's thesis  

Microsoft Academic Search

In accordance with the 1990 Clean Air Act Amendments (CAAA), this research conducts an evaluation of the potential emission of volatile organic compounds (VOCs) from selected Air Force wastewater treatment plants. Using a conservative mass balance analysis and process specific simulation models, volatile organic emission estimates are calculated for four individual facilities--Edwards AFB, Luke AFB, McGuire AFB, and McClellan AFB--which

Ouellette

1994-01-01

98

Emission of volatile organic sulfur compounds (VOSCs) during aerobic decomposition of food wastes  

Microsoft Academic Search

Food wastes collected from typical urban residential communities were investigated for the emission of volatile organic sulfur compounds (VOSCs) during laboratory-controlled aerobic decomposition in an incubator for a period of 41 days. Emission of VOSCs from the food wastes totaled 409.9mgkg?1 (dry weight), and dimethyl disulfide (DMDS), dimethyl sulfide (DMS), methyl 2-propenyl disulfide, carbonyl sulfide and methyl 1-propenyl sulfide were

Ting Wu; Xinming Wang; Dejun Li; Zhigang Yi

2010-01-01

99

Emissions of non-methane organic compounds from a grassland site  

Microsoft Academic Search

A mixture of oxygenated hydrocarbons (OxHCs), isoprene, and monoterpenes was detected in the emissions from a grassland site in the Midwestern United States. A plot dominated by crown vetch (Coronilla varia) and bluegrass (Poa spp.), exhibited a constant decrease in emissions of total non-methane organic compounds (NMOCs) from 580 μg m⁻² hr⁻¹ in June 1992 to 150 μg m{sup -

Yoshiko Fukui; P. V. Doskey

1996-01-01

100

Emissions of volatile organic compounds from hybrid poplar depend on CO2 concentration and genotype  

Microsoft Academic Search

Hybrid poplar is a fast-growing tree species that is likely to be an important source of biomass for the production of cellulose-based biofuels and may influence regional atmospheric chemistry through the emission of volatile organic compounds (VOCs). We used proton-transfer reaction mass spectrometry to measure VOC emissions from the leaves of four different hybrid poplar genotypes grown under ambient (400

A. S. Eller; J. A. de Gouw; R. K. Monson

2010-01-01

101

New global fire emission estimates and evaluation of volatile organic compounds  

NASA Astrophysics Data System (ADS)

A daily, high-resolution, global fire emissions model has been built to estimate emissions from open burning for air quality modeling applications: The Fire INventory from NCAR (FINN version 1). The model framework uses daily fire detections from the MODIS instruments and updated emission factors, specifically for speciated non-methane organic compounds (NMOC). Global daily fire emissions have been produced for 2005-August 2010. The improvements to the emission factors has led to an increase in simulated NMOC emissions when compared to other global emission estimates, including the Global Fire Emissions Database (GFED). Speciation profiles of the NMOC, based on the ecosystem in which the fire burns, have been developed for multiple chemical mechanisms including SAPRC99 and the MOZART-4 mechanisms. Two different fire emissions inventories (GFED and FINN) for 2008 have been used as inputs to various simulations of the MOZART-4 chemical transport model. The results have been compared to detailed airborne NMOC measurements made during the ARCTAS campaign. Using these model-observation comparisons, an initial assessment of the global fire emission inventories will be provided.

Wiedinmyer, C.; Emmons, L. K.; Akagi, S. K.; Yokelson, R. J.; Orlando, J. J.; Al-Saadi, J. A.; Soja, A. J.

2010-12-01

102

Analysis of trace organic compounds in vehicle emission using REMPI/TOF-MS  

NASA Astrophysics Data System (ADS)

Emission of fuel combustion in vehicle engines is one of the most important sources of urban environmental pollution. In this paper we present a new method for detecting trace pollution gases of vehicle emissions - laser mass spectrometry. The principles of the laser mass spectrometry is combination of resonant enhanced multiphoton ionization with flight-of-time mass spectroscopy. The experimental setup and results on the exhaust gas of a motorcycle are detailed. By excitation of 248nm KrF excimer laser, benzene and other aromatic compounds are detected in the motorcycle exhaust gases. The preliminary results of the concentration change of these compounds with speed are also presented.

Li, Ziyao; Wei, Jie; Xia, Zhuhong; Gu, Xuejun; Zhang, Liandi; Kong, Xianghe; Zheng, Haiyang; Zhang, Bing

2000-10-01

103

Leaf level emissions of volatile organic compounds (VOC) from some Amazonian and Mediterranean plants  

NASA Astrophysics Data System (ADS)

As volatile organic compounds (VOCs) significantly affect atmospheric chemistry (oxidative capacity) and physics (secondary organic aerosol formation and effects), emission inventories defining regional and global biogenic VOC emission strengths are important. The aim of this work was to achieve a description of VOC emissions from poorly described tropical vegetation to be compared with the quite well investigated and highly heterogeneous emissions from Mediterranean vegetation. For this task, common plant species of both ecosystems were investigated. Sixteen plant species from the Mediterranean area, which is known for its special diversity in VOC emitting plant species, were chosen. In contrast, little information is currently available regarding emissions of VOCs from tropical tree species at the leaf level. Twelve plant species from different environments of the Amazon basin, i.e. Terra firme, Várzea and Igapó, were screened for emission of VOCs at leaf level with a branch enclosure system. Analysis of the volatile organics was performed online by a proton-transfer-reaction mass spectrometer (PTR-MS) and offline by collection on adsorbent tubes and subsequent gas chromatographic analysis. Isoprene was quantitatively the most dominant compound emitted followed by monoterpenes, methanol and acetone. Most of the Mediterranean species emitted a variety of monoterpenes, whereas only five tropical species were monoterpene emitters exhibiting a quite conservative emission pattern (?-pinene > limonene > sabinene > ?-pinene). Mediterranean plants showed additional emissions of sesquiterpenes, whereas in the case of plants from the Amazon region no sesquiterpenes were detected probably due to a lack of sensitivity in the measuring systems. On the other hand methanol emissions, an indicator of growth, were common in most of the tropical and Mediterranean species. A few species from both ecosystems showed acetone emissions. The observed heterogeneous emissions including reactive VOC species which are not easily detected by flux measurements, give reason to perform more screening at leaf level and, whenever possible, within the forests under ambient conditions.

Bracho-Nunez, A.; Knothe, N. M.; Welter, S.; Staudt, M.; Costa, W. R.; Liberato, M. A. R.; Piedade, M. T. F.; Kesselmeier, J.

2012-11-01

104

Diurnal emission of volatile compounds by Japanese beetle-damaged grape leaves  

Microsoft Academic Search

The volatile compounds liberated by Japanese beetle (Popillia japonica Newman) feeding on grape leaves (Vitis labrúsca L.) were studied. Ten consecutive collections of 3 hr duration were performed on live vines starting at 09:00 and continuing until 15:00 the following day. Release of most compounds followed a diurnal pattern, with the period of peak emission from 12:00 to 15:00 and

John H. Loughrin; Daniel A. Potter; Thomas R. Hamilton-Kemp; Matthew E. Byers

1997-01-01

105

Comparison of carbonyl compounds emissions from diesel engine fueled with biodiesel and diesel  

Microsoft Academic Search

The characteristics of carbonyl compounds emissions were investigated on a direct injection, turbocharged diesel engine fueled with pure biodiesel derived from soybean oil. The gas-phase carbonyls were collected by 2,4-dinitrophenylhydrazine (DNPH)-coated silica cartridges from diluted exhaust and analyzed by HPLC with UV detector. A commercial standard mixture including 14 carbonyl compounds was used for quantitative analysis. The experimental results indicate

Chao He; Yunshan Ge; Jianwei Tan; Kewei You; Xunkun Han; Junfang Wang; Qiuwen You; Asad Naeem Shah

2009-01-01

106

A Global inventory of volatile organic compound emissions from anthropogenic sources  

NASA Astrophysics Data System (ADS)

As part of an effort to assess the potential impacts associated with global climate change, the U.S. Environmental Protection Agency's Office of Research and Development is supporting global atmospheric chemistry research by developing global scale estimates of volatile organic compound (VOC) emissions (excluding methane). Atmospheric chemistry models require, as one input, an emissions inventory of VOCs. Consequently, a global inventory of anthropogenic VOC emissions has been developed. The inventory includes VOC estimates for seven classes of VOCs: paraffins, olefins, aromatics (benzene, toluene, xylene), formaldehyde, other aldehydes, other aromatics, and marginally reactive compounds. These classes represent general classes of VOC compounds which possess different chemical reactivities in the atmosphere. The technical approach used to develop this inventory involved four major steps. The first step was to identify the major anthropogenic sources of VOC emissions in the United States and to group these sources into 28 general source groups. Source groups were developed to represent general categories such as "sources associated with oil and natural gas production" and more specific categories such as savanna buming. Emission factors for these source groups were then developed using different techniques and data bases. For example, emission factors for oil and natural gas production were estimated by dividing the United States' emissions from oil and gas production operations by the amount of oil and natural gas produced in the United States. Multiplication of these emission factors by production/consumption statistics for other countries yielded global VOC emission estimates for specific source groups within those countries. The final step in development of the VOC inventory was to distribute emissions into 10° by 10° grid cells using detailed maps of population and industrial activity. The results of this study show total global anthropogenic VOC emissions of about 110,000 Gg/yr. This estimate is about 10% lower than global VOC inventories developed by other researchers. The study identifies the United States as the largest emitter (21% of the total global VOC), followed by the (former) USSR, China, India, and Japan. Globally, fuel wood combustion and savanna burning were among the largest VOC emission sources, accounting for over 35% of the total global VOC emissions. The production and use of gasoline, refuse disposal activities, and organic chemical and rubber manufacturing were also found to be significant sources of VOC emissions.

Piccot, Stephen D.; Watson, Joel J.; Jones, Julian W.

1992-06-01

107

Validation of emission inventories by measurements of ambient volatile organic compounds in Beijing, China  

NASA Astrophysics Data System (ADS)

Understanding the sources of volatile organic compounds (VOCs) is essential for ground-level ozone and secondary organic aerosols (SOA) abatement measures. We made measurements at 28 sites and online observations at an urban site in Beijing from July 2009 to January 2012. From these we determined the spatial and temporal distributions of VOCs, estimated their annual emission strengths based on their emission ratios relative to CO, and quantified the relative contributions of various sources using the chemical mass balance (CMB) model. The results from ambient measurements were compared with existing emission inventories to evaluate the spatial distribution, species-specific emissions, and source structure of VOCs. The measured VOC distributions revealed a hotspot in the southern suburban area of Beijing, whereas current emission inventories suggested that VOC emissions were concentrated in downtown areas. Compared with results derived from ambient measurements, the annual inventoried emissions of oxygenated VOC (OVOC) species and C2-C4 alkanes might be underestimated, while the emissions of styrene and 1,3-butadiene might be overestimated by current inventories. Source apportionment using the CMB model identified vehicular exhaust as the most important VOC source, contributing 46%, in good agreement with the 40-51% assumed by emission inventories. However, the relative contribution of solvent and paint usage obtained from the CMB model was only 5%, significantly lower than the values reported by emission inventories (14-32%). Meanwhile, the relative contribution of industrial processes calculated using the CMB model was 17%, slightly higher than that in emission inventories. These results suggested that VOCs emission strengths in southern suburban area of Beijing, annual emissions of alkenes and OVOCs, and the contributions of solvent and paint usage and industrial processes in current inventories, all require significant revision.

Wang, M.; Shao, M.; Chen, W.; Yuan, B.; Lu, S.; Zhang, Q.; Zeng, L.; Wang, Q.

2013-10-01

108

Volatile organic compound emissions from elephant grass and bamboo cultivars used as potential bioethanol crop  

NASA Astrophysics Data System (ADS)

Volatile organic compound (VOC) emissions from elephant grass (Miscanthus gigantus) and black bamboo (Phyllostachys nigra) were measured online in semi-field chamber and plant enclosure experiments during growth and harvest using proton-transfer reaction mass spectrometry (PTR-MS), proton-transfer reaction ion-trap mass spectrometry (PIT-MS) and gas chromatography-mass spectrometry (GC-MS). Both cultivars are being considered for second-generation biofuel production. Before this study, no information was available on their yearly VOC emissions. This exploratory investigation shows that black bamboo is a strong isoprene emitter (daytime 28,516 ng gdwt-1 h-1) and has larger VOC emissions, especially for wound compounds from the hexanal and hexenal families, than elephant grass. Daytime emissions of methanol, acetaldehyde, acetone + propanal and acetic acid of black bamboo were 618, 249, 351, and 1034 ng gdwt-1 h-1, respectively. In addition, it is observed that elephant grass VOC emissions after harvesting strongly depend on the seasonal stage. Not taking VOC emission variations throughout the season for annual and perennial species into account, may lead to an overestimation of the impact on local air quality in dry periods. In addition, our data suggest that the use of perennial grasses for extensive growing for biofuel production have lower emissions than woody species, which might be important for regional atmospheric chemistry.

Crespo, E.; Graus, M.; Gilman, J. B.; Lerner, B. M.; Fall, R.; Harren, F. J. M.; Warneke, C.

2013-02-01

109

[The emission flux of volatile organic compounds in the Inner Mongolia Grassland].  

PubMed

During the summer season of 2002, emissions of volatile organic compounds were firstly measured by a static enclosure technique at a grassland site in the Inner Mongolia grassland. The parameters including solar radiation, air temperature and relative humidity were also measured in the same time period. The results showed that isoprene was the main component of volatile organic compounds emitted from the grassland. Isoprene exhibited an evident diurnal, daily and seasonal variation. Solar visible radiation, air temperature and water vapor content were the main factors to affect isoprene emission, and solar visible radiation was the most important factor to control the isoprene emission. Base on the correlation analysis, when considering the affecting factors of isoprene emission, it is not only to consider solar visible radiation, temperature, but also the water vapor. It is impossible to avoid the changes of solar radiation, temperature and humidity between inside and outside the chamber by using the enclosure technique. So, it is necessary to take these effects into the considerations and modify isoprene emission. In summer 2002, the maximum emission flux (C) of isoprene was 1649.3 micrograms/(m2.h), and monthly averaged emission flux (C) in June, August and September were 886.6, 707.0 and 427.2 micrograms/(m2.h), respectively. PMID:14768559

Bai, Jianhui; Wang, Gengchen; Ren, Lixin; Baker, Brad; Zimmerman, Patrick; Liang, Baosheng

2003-11-01

110

Spatio-temporal variation of biogenic volatile organic compounds emissions in China.  

PubMed

Aiming to reduce the large uncertainties of biogenic volatile organic compounds (BVOCs) emissions estimation, the emission inventory of BVOCs in China at a high spatial and temporal resolution of 36 km × 36 km and 1 h was established using MEGANv2.1 with MM5 providing high-resolution meteorological data, based on the most detailed and latest vegetation investigations. BVOC emissions from 82 plant functional types in China were computed firstly. More local species-specific emission rates were developed combining statistical analysis and category classification, and the leaf biomass was estimated based on vegetation volume and production with biomass-apportion models. The total annual BVOC emissions in 2003 were 42.5 Tg, including isoprene 23.4 Tg, monoterpene 5.6 Tg, sesquiterpene 1.0 Tg, and other VOCs (OVOCs) 12.5 Tg. Subtropical and tropical evergreen and deciduous broadleaf shrubs, Quercus, and bamboo contributed more than 45% to the total BVOC emissions. The highest biogenic emissions were found over northeastern, southeastern, and southwestern China. Strong seasonal pattern was observed with the highest BVOC emissions in July and the lowest in January and December, with daily emission peaked at approximately 13:00 or 14:00 local time. PMID:23916627

Li, L Y; Chen, Y; Xie, S D

2013-07-31

111

Estimating the emission of volatile organic compounds (VOC) from the French forest ecosystem  

NASA Astrophysics Data System (ADS)

The present assessment of annual foliar emissions of non-methane volatile organic compounds (VOC) was carried out from a selection of 32 different varieties of trees representing 98% of the French forest. Experimental data were collected over a grid based on the 93 metropolitan departments (national districts). Specific emission potentials and foliar densities were individually assigned to each of the 32 species. Temperatures and light intensities were individually collected for all French departments. As far as possible, the specific emission factors taken into account in the algorithms used for calculating emission were characteristic of species growing in France or nearby. Average monthly and annual emissions of isoprene, monoterpenes and other volatile organic compounds (OVOC) were individually obtained for all departments and for France over the five-year period of the present investigation (1994-1998). The results indicate a periodical annual evolution of average emissions characterized by a rapid growth from March up to a maximum reached in July-August and followed by a net decrease in September-October. The emissions recorded during the months of July and August represent more than 50% of the annual values. Over the whole country, isoprene appears as the most abundant species, with an emission of 457 kt yr -1, followed by monoterpenes, 350 kt yr ?-1 and OVOC, 129 kt yr -1, such values, respectively, representing 49, 37 and 14% of the total emission. The level of VOC emissions of biogenic origin in France is 50% lower than that of anthropogenic sources. As a whole, the results are affected by a rather large uncertainty, due to the importance of calculated corrective factors, ranged between 4 and 7.

Simon, V.; Luchetta, L.; Torres, L.

112

Leaf level emissions of volatile organic compounds (VOC) from some Amazonian and Mediterranean plants  

NASA Astrophysics Data System (ADS)

Emission inventories defining regional and global biogenic volatile organic compounds (VOC) emission strengths are needed to determine the impact of VOC on atmospheric chemistry (oxidative capacity) and physics (secondary organic aerosol formation and effects). The aim of this work was to contribute with measurements of tree species from the poorly described tropical vegetation in direct comparison with the quite well-investigated, highly heterogeneous emissions from Mediterranean vegetation. VOC emission from sixteen plant species from the Mediterranean area were compared with twelve plant species from different environments of the Amazon basin by an emission screening at leaf level using branch enclosures. Analysis of the volatile organics was performed online by a proton-transfer-reaction mass spectrometer (PTR-MS) and offline by collection on adsorbent tubes and subsequent gas chromatographic analysis. Isoprene was the most dominant compound emitted followed by monoterpenes, methanol and acetone. The average loss rates of VOC carbon in relation to the net CO2 assimilation were found below 4% and indicating normal unstressed plant behavior. Most of the Mediterranean species emitted a large variety of monoterpenes, whereas only five tropical species were identified as monoterpene emitters exhibiting a quite conservative emission pattern (?-pinene < limonene < sabinene < ß-pinene). Mediterranean plants showed additional emissions of sesquiterpenes. In the case of Amazonian plants no sesquiterpenes were detected. However, missing of sesquiterpenes may also be due to a lack of sensitivity of the measuring systems. Furthermore, our screening activities cover only 1% of tree species of such tropical areas as estimated based on recent biodiversity reports. Methanol emissions, an indicator of growth, were found to be common in most of the tropical and Mediterranean species. A few species from both ecosystems showed acetone emissions. The observed heterogeneous emissions, including reactive VOC species which are not easily detected by flux measurements, give reason to perform more screening at leaf level and, whenever possible, within the forests under ambient conditions.

Bracho-Nunez, A.; Knothe, , N. M.; Welter, S.; Staudt, M.; Costa, W. R.; Liberato, M. A. R.; Piedade, M. T. F.; Kesselmeier, J.

2013-09-01

113

Oxidized and reduced biogenic nitrogen compound emissions into the rural troposphere: Characterization and modeling  

NASA Astrophysics Data System (ADS)

Using a dynamic flow-through chamber technique in conjunction with a state-of-the-art mobile laboratory, this research attempts to characterize and model oxidized and reduced biogenic nitrogen compound emissions into the rural troposphere. Nitrogen compound emissions are known to have profound effects on air quality. Consequences associated with increased emissions of oxidized and reduced nitrogen species are known to be increased tropospheric ozone production, fine particulate aerosol production, nitrate contamination of drinking water, eutrophication and acidification of soil and water bodies. It is well recognized that soil emissions can contribute a substantial percent of the total inventory for both the oxidized and reduced species, but great uncertainty still exists in this inventory. A controlled experiment involving the application of municipal waste biosolids to agricultural soils was shown to enhance NO emissions. A more detailed analysis throughout several seasons found the nitric oxide emissions from biosolid amended soils to have a strong temperature dependence and that their source strength is much larger relative to soils amended with chemically derived fertilizers. Emissions of nitric oxide from biosolid amended soils were modeled using the MultiScale Air Quality Simulation Platform (MAQSIP). Results from this model indicated that ozone concentrations can decrease by approximately 12% (in the evening) and increase by approximately 2% (during the daylight hours) when these biosolid amended soils are taken into consideration in the land use database. Emissions of ammonia from soils amended with swine waste effluent were also measured and modeled. This study revealed that while the average source strength of ammonia from soils is significantly smaller than that of the lagoons, the much larger surface area of the soils causes them to also be an important emissions source. A fundamental mechanistic mass transfer model is presented and discussed in terms of its applicability for estimating NH3 flux and was found to be an effective predictor of the NH3 emissions for time periods immediately following slurry application.

Roelle, Paul Andrew

2001-12-01

114

BIOGENIC VOLATILE ORGANIC COMPOUND EMISSIONS FROM DESERT VEGETATION OF THE SOUTHWESTERN U.S.  

EPA Science Inventory

Thirteen common plant species in the Mojave and Sonoran Desert regions of the western United States were tested for emissions of biogenic non-methane volatile organic compounds (BVOCs). Only two of the species examined emitted isoprene at rates of 10 µgCg?1 ...

115

GASEOUS HC1 AND CHLORINATED ORGANIC COMPOUND EMISSIONS FROM REFUSE FIRED WASTE-TO-ENERGY SYSTEMS  

EPA Science Inventory

The emissions from a water wall mass fired municipal waste incinerator and a refuse derived fuel (RDF) fired incinerator were sampled for chlorinated organic compounds and hydrochloric acid (HCl). The sampling was performed to evaluate the extractive sampling methods used to meas...

116

EMISSIONS OF DIOXINS AND RELATED COMPOUNDS FROM COMBUSTION AND INCINERATION SOURCES  

EPA Science Inventory

This report on the emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans was prepared as a contribution to the Pilot Study on International Information Exchange on Dioxins and Related Compounds. he report describes the state of the art with respect to combustion and th...

117

EMISSION OF VOLATILE ORGANIC COMPOUNDS FROM DRUM-MIX ASPHALT PLANTS  

EPA Science Inventory

This research program was undertaken in order to develop a quantitative estimate of the emission of volatile organic compounds (VOCs) from drum-mix asphalt plants. The study was carried out by field sampling of five drum-mix plants under a variety of operating conditions. Include...

118

Microbial community related to volatile organic compound (VOC) emission in household biowaste  

Microsoft Academic Search

Summary Malodorous emissions and potentially pathogenic microorganisms which develop during domestic organic waste collection are not only a nuisance but may also pose health risks. The aim of the present study was to determine whether the presence of spe- cific microorganisms in biowastes is directly related to the composition of the emitted volatile organic compounds (VOCs). The succession of microbial

Sabine Mayrhofer; Tomas Mikoviny; Sebastian Waldhuber; Andreas O. Wagner; Gerd Innerebner; Ingrid H. Franke-Whittle; Tilman D. Märk; Armin Hansel; Heribert Insam

2006-01-01

119

76 FR 74014 - Approval and Promulgation of Implementation Plans; Illinois; Volatile Organic Compound Emission...  

Federal Register 2010, 2011, 2012, 2013

...Compound Emission Control Measures for Chicago and Metro-East St. Louis Ozone Nonattainment...rules provide RACT requirements for the Chicago and Metro-East St. Louis 8-hour ozone...Protection Agency, 77 West Jackson Boulevard, Chicago, Illinois 60604. Hand...

2011-11-30

120

Volatile organic compound emissions from wastewater treatment plants in Taiwan: Legal regulations and costs of control  

Microsoft Academic Search

This study assessed volatile organic compound (VOC) emission characteristics from wastewater treatment plants (WWTPs) in five Taiwanese industrial districts engaged in numerous manufacturing processes, including petrochemical, science-based industry (primarily semiconductors, photo-electronics, electronic products and biological technology), as well as multiple manufacturing processes (primarily pharmaceuticals and paint manufacturing). The most aqueous hydrocarbons dissolved in the wastewater of Taiwanese WWTPs were acetone,

Wen-Hsi Cheng; Shu-Kang Hsu; Ming-Shean Chou

2008-01-01

121

Source Location and Characterization of Volatile Organic Compound Emissions at a Petrochemical Plant in Kaohsiung, Taiwan  

Microsoft Academic Search

This paper elucidated a novel approach to locating volatile organic compound (VOC) emission sources and characterizing their VOCs by database and contour plotting. The target of this survey was a petrochemical plant in Linyan, Kaohsiung County, Taiwan. Samples were taken with canisters from 25 sites inside this plant, twice per season, and analyzed by gas chromatography–mass spectrometry. The survey covered

Chin-Liang Chen; Hung Yuan Fang; Chi-Min Shu

2005-01-01

122

Biogenic volatile organic compound emissions from a lowland tropical wet forest in Costa Rica  

Microsoft Academic Search

Twenty common plant species were screened for emissions of biogenic volatile organic compounds (BVOCs) at a lowland tropical wet forest site in Costa Rica. Ten of the species examined emitted substantial quantities of isoprene. These species accounted for 35–50% of the total basal area of old-growth forest on the major edaphic site types, indicating that a high proportion of the

Chris Geron; Alex Guenther; Jim Greenberg; Henry W. Loescher; Deborah Clark; Brad Baker

2002-01-01

123

Emission of charged particles from excited compound nuclei 90,94,98Mo  

NASA Astrophysics Data System (ADS)

The production and decay processes of compound nuclei are studied in the framework of the dinuclear system model, using proximity potentials. Cross-sections for the emission of complex fragments are computed and compared against the experimental data for the reactions 78,82,86Kr + 12C. A good consistency between the results of this work and the experimental data is obtained.

Davoodabadi, S.; Nazarzadeh, P.

2013-09-01

124

An enclosure technique for measuring nonmethane organic compound emissions from grasslands  

Microsoft Academic Search

A static chamber technique for measuring emissions of nonmethane organic compounds (NMOCs) from soil surfaces and herbaceous vegetation in a natural setting has been developed. The technique involves the insertion of a polymethyl methacrylate frame into the ground. A polycarbonate chamber is placed in a water-containing trough on the frame to seal the chamber to the surface. The soil surface

Yoshiko Fukui; Paul V. Doskey

1996-01-01

125

Volatile Organic Compound Emissions from Municipal Solid Waste Disposal Sites: A Case Study of Mumbai, India  

Microsoft Academic Search

Improper solid waste management leads to aesthetic and environmental problem. Emission of volatile organic compounds is one of the problems from uncontrolled dumpsite. VOCs are well known to be hazardous to human health and are many of them are known or potential carcinogens. They also contribute to ozone formation at ground level and climate change as well. The qualitative and

Dipanjali Majumdar; Anjali Srivastava

2012-01-01

126

Emissions of Chemical Compounds and Bioaerosols During the Secondary Treatment of Paper Mill Effluents  

Microsoft Academic Search

This study identified and quantified the main chemical compounds—the substances responsible for the disagreeable odors—and the bioaerosols emitted during the biological treatment of paper mill effluents. It also identified the characteristics of the process that effects the generation or diffusion of these substances. All treatment stages were evaluated. Measuring sites were located as closely as possible to the potential emission

Nicole Goyer; Jacques Lavoie

2001-01-01

127

Characterizing and mitigating emissions of volatile organic compounds from animal feeding operations  

Technology Transfer Automated Retrieval System (TEKTRAN)

Volatile organic compounds (VOC) emitted from animal feeding operations negatively impact local and potentially regional air quality though the release of both odorous and ozone precursor molecules. Characterizing emissions of VOCs from AFOs is strongly influenced by both the method and location of ...

128

VOC (VOLATILE ORGANIC COMPOUNDS) FUGITIVE EMISSION DATA - HIGH DENSITY POLYETHYLENE PROCESS UNIT  

EPA Science Inventory

The report gives data from a 10-month study of volatile organic compound (VOC) fugitive emissions from a high density polyethylene process unit. It gives statistics on leak frequency, leak occurrence, and leak recurrence, with a leak defined as having a screening value equal to o...

129

Volatile compounds emission from canopy fine litterfall in a hemiboreal mixed forest at Järvselja  

NASA Astrophysics Data System (ADS)

The seasonal distribution of biogenic volatile organic compounds (BVOC) emissions from canopy fine litterfall was investigated over a period of two years. Three stands of a hemiboreal mixed forest were studied. The stands presented different dominant tree species: (1) Norway spruce, (2) Scots pine, and (3) Silver birch and Downy birch. The litterfall was monthly collected in litter traps. The BVOC emission of litter was sampled by placing the litter into a glass jar equipped with a vent tube and pumping the head space air through a VOC adsorbing tube (carbotrap). Adsorbed BVOCs were analyzed in a GC-MS. Fifteen compounds were quantified. Seasonal differences in the total emission of BVOCs were found, defined by a maximum in summer and a minimum in autumn and winter. During summer months, litter emissions were dominated by limonene, ?-pinene, camphene and 3-carene in the three litter types, accounting for 70-75 % of total BVOC emitted in June. 3-Carene, ?-pinene and ?-pinene were the main compounds emitted during winter time, accounting for 50-60 % of total BVOC emitted in January. Stand to stand differences were assessed. The spruce and birch dominated stands showed more similarities in their BVOC emission pattern if compared to the pine dominated stand. Together with the litterfall data, an estimation of the annual total BVOC emitted by the soil litter layer is presented for each stand type.

Portillo-Estrada, Miguel; Noe, Beate; Noe, Steffen M.

2013-04-01

130

Emissions of carbon species, organic polar compounds, potassium, and mercury from prescribed burning activities  

NASA Astrophysics Data System (ADS)

Biomass burning is an important emission source of pollutants to the atmosphere, but few studies have focused on the chemical composition of emissions from prescribed burning activities. Here we present results from a sampling campaign to quantify particulate-phase emissions from various types of prescribed fires including carbon species (Elemental Carbon: EC; Organic Carbon: OC; and Total Carbon: TC); polar organic compounds (12 different compounds and four functional classes); water-soluble potassium (K+); and mercury (Hg). We measured emissions from the following types of prescribed biomass burning in the Lake Tahoe basin located on the California/Nevada border: (i) log piles stacked and dried in the field; (ii) log piles along with green understory vegetation; and (iii) understory green vegetation and surface litter; further emissions were collected from burns conducted in a wood stove: (iv) dried wooden logs; (v) green foliage of understory vegetation collected from the field; and (vi) surface organic litter collected from the field; finally, samples were also taken from (vii) ambient air in residential areas during peak domestic wood combustion season. Results show that OC/EC ratios of prescribed burns in the field ranged from 4 to 10, but lower values (around 1) were observed in controlled stove fires. These results are consistent with an excess of OC emissions over EC found in wildfires. OC/EC ratios, however, showed clear separations between controlled wood stove combustion (higher EC) and prescribed burns in the field (lower EC). We attribute this difference to a higher combustion temperatures and dominance of flaming combustion in wood stove fires. OC positively and linearly correlated to the sum of polar organic compounds across all burn types (r2 of 0.82). The most prevalent group of polar compounds emitted during prescribed fires was resin acids (dehydroabietic, pimaric, and abietic acids), followed by levoglucosan plus mannositol. Negligible contributions were observed for inositols, arabitols, and lignin derivates. Although some of these polar compound classes are linked to specific woody or green tissues, we found no significant differences of emission ratios between different types of fires. Water-soluble K+, a common tracer for biomass combustion, showed a clear separation between understory burns (low K+) and wooden pile burns (10 to 20 times higher), suggesting that K+ can potentially be used for differentiating between green versus dry, wooden biomass combustion. Finally, Hg emissions were very low across all fire emissions collected, but were enhanced in urban air sampling which might allow for differentiating sources from biomass combustion from other urban sources.

Zhang, Y.; Obrist, D.; Zielinska, B.; Gerler, A.

2012-04-01

131

Characterization of emissions of volatile organic compounds from interior alkyd paint.  

PubMed

Alkyd paint continues to be used indoors for application to wood trim, cabinet surfaces, and some kitchen and bathroom walls. Alkyd paint may represent a significant source of volatile organic compounds (VOCs) indoors because of the frequency of use and amount of surface painted. The U.S. Environmental Protection Agency (EPA) is conducting research to characterize VOC emissions from paint and to develop source emission models that can be used for exposure assessment and risk management. The technical approach for this research involves both analysis of the liquid paint to identify and quantify the VOC contents and dynamic small chamber emissions tests to characterize the VOC emissions after application. The predominant constituents of the primer and two alkyd paints selected for testing were straight-chain alkanes (C9-C12); C8-C9 aromatics were minor constituents. Branched chain alkanes were the predominant VOCs in a third paint. A series of tests were performed to evaluate factors that may affect emissions following application of the coatings. The type of substrate (glass, wallboard, or pine board) did not have a substantial impact on the emissions with respect to peak concentrations, the emissions profile, or the amount of VOC mass emitted from the paint. Peak concentrations of total volatile organic compounds (TVOCs) as high as 10,000 mg/m3 were measured during small chamber emissions tests at 0.5 air exchanges per hour (ACH). Over 90% of the VOCs were emitted from the primer and paints during the first 10 hr following application. Emissions were similar from paint applied to bare pine board, a primed board, or a board previously painted with the same paint. The impact of other variable, including film thickness, air velocity at the surface, and air-exchange rate (AER) were consistent with theoretical predictions for gas-phase, mass transfer-controlled emissions. In addition to the alkanes and aromatics, aldehydes were detected in the emissions during paint drying. Hexanal, the predominant aldehyde in the emissions, was not detected in the liquid paint and was apparently an oxidation product formed during drying. This paper summarizes the results of the product analyses and a series of small chamber emissions tests. It also describes the use of a mass balance approach to evaluate the impact of test variables and to assess the quality of the emissions data. PMID:9798433

Fortmann, R; Roache, N; Chang, J C; Guo, Z

1998-10-01

132

Emission control of sodium compounds and their formation mechanisms during coal combustion  

SciTech Connect

In order to control emissions of sodium compounds during coal combustion, the sorbent injection technology is tested during coal combustion. Kaolin is selected as the sorbent to absorb vapors of sodium compounds evolved from the coals. In the combustion experiments, the kaolin is physically mixed with coal. Two types of coal, which have the similar coal properties, are burned. Combustion tests are conducted, using an electrically heated drop tube furnace, to study effect of kaolin addition on the capture characteristics of sodium compounds. In order to elucidate fundamentals on transformation behaviors of sodium compounds during hydrogen-air combustion, chemical kinetic simulation by elementary reactions relating to sodium compounds is also performed, varying the reaction atmosphere. As a result, the kaolin can effectively capture the vapor of sodium compounds even during coal combustion. The capture efficiency depends on the coal type. The sodium compounds for the coals, which produce many fine particles with size of less than 1 {mu}m, tend to be effectively captured by the kaolin. According to the kinetic simulation of sodium species, difference of the reaction atmosphere affects occurrence species of sodium vapor. In the combustion region, the sodium compounds become metallic sodium vapor in any reaction atmospheres due to occurrence of the reducing radical species. HCl gas rather than SO{sub 2} gas plays an important role to transform gaseous sodium compounds. 44 refs., 8 figs., 3 tabs.

Tsuyoshi Takuwa; Ichiro Naruse [Toyohashi University of Technology, Toyohashi (Japan). Department of Ecological Engineering

2007-07-01

133

Doubled volatile organic compound emissions from subarctic tundra under simulated climate warming.  

PubMed

*Biogenic volatile organic compound (BVOC) emissions from arctic ecosystems are important in view of their role in global atmospheric chemistry and unknown feedbacks to global warming. These cold ecosystems are hotspots of climate warming, which will be more severe here than averaged over the globe. We assess the effects of climatic warming on non-methane BVOC emissions from a subarctic heath. *We performed ecosystem-based chamber measurements and gas chromatography-mass spectrometry (GC-MS) analyses of the BVOCs collected on adsorbent over two growing seasons at a wet subarctic tundra heath hosting a long-term warming and mountain birch (Betula pubescens ssp. czerepanovii) litter addition experiment. *The relatively low emissions of monoterpenes and sesquiterpenes were doubled in response to an air temperature increment of only 1.9-2.5 degrees C, while litter addition had a minor influence. BVOC emissions were seasonal, and warming combined with litter addition triggered emissions of specific compounds. *The unexpectedly high rate of release of BVOCs measured in this conservative warming scenario is far above the estimates produced by the current models, which underlines the importance of a focus on BVOC emissions during climate change. The observed changes have implications for ecological interactions and feedback effects on climate change via impacts on aerosol formation and indirect greenhouse effects. PMID:20456056

Faubert, Patrick; Tiiva, Päivi; Rinnan, Asmund; Michelsen, Anders; Holopainen, Jarmo K; Rinnan, Riikka

2010-04-28

134

Emission of volatile organic compounds (VOC) from tropical plant species in India.  

PubMed

Foliar emission of volatile organic compounds (VOC) from common Indian plant species was measured. Dynamic flow enclosure technique was used and the gas samples were collected onto Tenax-GC/Carboseive cartridges. The Tenax-GC/Carboseive cartridges were attached to the thermal disorber sample injection system and the gas sample was analysed using gas chromatography (GC) with flame ionisation detection (FID). Fifty-one local plant species were screened, out of which 36 species were found to emit VOC (4 high emitter; 28 moderate emitter; and 4 low-emitter), while in the remaining 15 species no VOC emission was detected or the levels of emission were below detection limit (BDL). VOC emission was found to vary from one species to another. There was a marked seasonal and diurnal variation in VOC emission. The minimum and maximum VOC emission values were < 0.1 and 87 microgg(-1) dry leaf h(-1) in Ficus infectoria and Lantana camara respectively. Out of the 51 plant species studied, 13 species are reported here for the first time. Among the nine tree species (which were selected for detailed study), the highest average hourly emission (9.69+/-8.39 microgg(-1) dry leaf) was observed in Eucalyptus species and the minimum in Syzygium jambolanum (1.89+/-2.48 microgg(-1) dry leaf). An attempt has been made to compare VOC emission from different plant species between present study and the literature (tropical and other regions). PMID:15894050

Padhy, P K; Varshney, C K

2005-06-01

135

Inventory of fine particulate organic compound emissions from residential wood combustion in Portugal  

NASA Astrophysics Data System (ADS)

In the early fall of 2010 a survey questionnaire was conducted to assess residential wood combustion (RWC) practices in the 18 districts of mainland Portugal. This paper describes and analyses the results from a bottom-up approach, based on this telephone survey, which enabled the characterisation of RWC practices in each district. Additionally, emission factors and source profiles obtained from different RWC tests, allowed the estimation of CO, CO2, PM2.5 and particulate organic compound emissions on a country-scale. The type and number of RWC appliances, each with their specific emissions factor and the amount and type of fuel used vary significantly on a district scale. The energy consumption in RWC appliances was estimated to be 35 342 TJ y-1. The estimated emissions of PM2.5 from RWC in Portugal (10.96 kt y-1) represent 30% of the estimate for different source activities reported in a recent inventory. The national emissions of OC and EC were estimated to be 5.32 and 0.53 kt y-1, respectively. It was also estimated that the total CO2 emissions from RWC in Portugal are 1.7 Mt y-1. The levoglucosan emissions contribute with between 7.8% and 16.1% of PM2.5 emissions from RWC.

Gonçalves, Cátia; Alves, Célia; Pio, Casimiro

2012-04-01

136

Contribution of developing foliage to canopy emissions of volatile organic compounds  

NASA Astrophysics Data System (ADS)

Biogenic sources play a key role in volatile organic compounds (VOC) budget especially in rural areas. The evergreen coniferous forests are the main source of VOCs in many boreal regions. Significant seasonality in emission strength from coniferous trees has been reported, which mostly has been related to prevailing temperatures. Emission modeling is based on parameterizations obtained from short term field campaigns or intermittent measurements from mature foliage during the maximun emission period in mid-summer. However, the developing foliage may significantly differ in emission patterns (both quality and quantity) from the mature foliage, and this variability has not been accounted for in regional modeling approaches. Therefore long-term online emission measurements from developing biomass are necessary. We set up an automated system consisting of several dynamic shoot enclosures and a PTR-MS (Proton Transfer Reaction Mass Spectrometer) at the SMEAR II station (Station for Measuring forest Ecosystem-Atmosphere Relationships) in southern Finland. Emissions from both mature and developing Scots pine shoots were measured for three years over the whole spring and growing season, and the shoot and needle growth were measured simultaneously. Emission rates were calculated based on needle mass in the end of growing season, and compared with those of mature shoot. The developing shoots emitted significantly more methanol (M33), acetone (M59), isoprene + MBO (M69) and monoterpenes (M137) than the mature ones. Needle elongation rate correlated with the ratio between the emissions from developing and mature shoot. After the needle elongation period in late July, emissions from the current year shoots were equal or less than those from the previous year's shoot. The conditions during the growing season affect needle biomass growth and thus also the emission capacity of the mature foliage in the following year. During springs 2009 and 2010 the monoterpene emission rates from the developing shoots were several orders of magnitude higher than those of the mature shoots. During spring 2011 the monoterpene emissions from the developing shoot were lower than those from the mature shoot. The temperature dependency of emissions varies from year to year, and seems to be related with the growth rate of the shoot. Our results clearly demonstrate that actively growing new biomass is a strong source for VOCs in the Scots pine canopy, and indicate that the cumulative seasonal canopy emission estimates based on upscaling from mature foliage may be significantly biased. The seasonal patterns of the factors regulating emissions need to be more carefully analyzed, and the emission rate parameterisations revised for the foliage growth period.

Bäck, J.; Aalto, J.; Kolari, P.; Hari, P.; Kulmala, M.

2012-04-01

137

Biogenic emissions of volatile organic compounds from gorse (Ulex europaeus): Diurnal emission fluxes at Kelling Heath, England  

NASA Astrophysics Data System (ADS)

Volatile organic compound (VOC) emission fluxes from Gorse (Ulex europaeus) were measured during May 30-31, 1995 at Kelling Heath in eastern England by using bag enclosure and gradient methods simultaneously. The enclosure measurements were made from branches at different stages of physiological development (flowering, after flowering, and mixed). Isoprene was found to represent 90% of the total VOC emissions, and its emission rates fluctuated from 6 ng (g dwt)-1 h-1 in the early morning to about 9700 ng(g dwt)-1 h-1 at midday. Averaged emission rates standardized to 20°C were 1625, 2120, and 3700 ng (g dwt)-1 h-1 for the new grown, "mixed," and flowering branch, respectively. Trans-ocimene and ?-pinene were the main monoterpenes emitted and represented, on average, 47.6% and 36.9% of the total monoterpenes. Other monoterpenes, camphene, sabinene, ?-pinene, myrcene, limonene and ?-terpinene, were positively identified but together represented less than 1.5% of the total VOC emissions from gorse. Maximum isoprene concentrations in air at the site were measured around midday at 2 m (174 parts per trillion by volume, or pptv) and 6 m (149 pptv), and minimum concentrations were measured during the night (8 pptv at both heights). Mean daytime ?-pinene air concentrations of 141 and 60 pptv at 2 and 6 m height were determined, but trans-ocimene concentrations were less than the analytical detection limit (4 pptv), suggesting rapid chemical removal of this compound from air. The isoprene fluxes calculated by the micrometeorological gradient method showed a pattern similar to that of those calculated by the enclosure method, with isoprene emission rates maximum at midday (100 ?g m-2 h-1) and not detectable during the nighttime. Assessment of the fraction of the site covered by gorse plants enabled an extrapolation of emission fluxes from the enclosure measurements. When averaged over the 2 day experiment, isoprene fluxes of 29.8 and 27.8 ?g m-2 h-1 were obtained from the gradient and the enclosure extrapolation respectively. These isoprene fluxes to the atmosphere represented between 0.12% and 0.35% of the net assimilated carbon (as CO2) uptake rate for gorse.

Cao, X.-L.; Boissard, C.; Juan, A. J.; Hewitt, C. N.; Gallagher, M.

1997-08-01

138

Emissions of Biogenic Volatile Organic Compounds and Observations of VOC Oxidation at Harvard Forest  

NASA Astrophysics Data System (ADS)

The contribution of biogenic volatile organic compounds (BVOCs) to oxidant concentrations and secondary organic aerosol (SOA) production in forested environments depends on the emission rates of these compounds. Recent findings have suggested that the emission rates of BVOCs and the range of species emitted could be larger than previously thought. In this study, Proton Transfer Reaction Mass Spectrometry (PTR-MS) was used to obtain fast (<1 Hz) measurements of the predominant BVOC species, including isoprene, monoterpenes, and oxygenated BVOCs, above the canopy at Harvard Forest (Petersham, MA) during the summers of 2005, 2007, and 2008. Together with vertical wind data, these measurements are used to determine fluxes of BVOCs out of the forest using the virtual disjunct eddy covariance method. Concentrations of additional VOCs, including methyl vinyl ketone + methacrolein and terpene oxidation products were also measured. Isoprene is the dominant emitted species, with peak emission rates and midday mixing ratios of ca. 4 mg isoprene m-2 h-1 and ca. 5 ppbv, respectively. Isoprene emission rates are expected to vary with temperature and radiation (PAR) levels, and are compared to standard emission algorithms based on these parameters. Interannual variability in isoprene emission rates is also observed, and contributing factors are explored. In contrast to isoprene, maximum monoterpene concentrations typically were less than 1 ppbv and occurred in the early evening, with a local minimum at midday. Monoterpene fluxes are about an order of magnitude smaller than those of isoprene. The amplitude of the flux diurnal cycle suggests monoterpene emissions at Harvard Forest may exhibit light dependence as well as temperature dependence. Fluxes of oxygenated VOCs, including methanol, acetone, methyl ethyl ketone, and oxygenated terpenes that have rarely been observed previously, are also reported, and the dependence of their emission rates on factors such as time of year, temperature, radiation levels, and meteorological conditions are investigated.

McKinney, K. A.; Pho, T.; Vasta, A.; Lee, B. H.

2009-12-01

139

Contribution of flowering trees to urban atmospheric biogenic volatile organic compound emissions  

NASA Astrophysics Data System (ADS)

Emissions of biogenic volatile organic compounds (BVOC) from urban trees during and after blooming were measured during spring and early summer 2009 in Boulder, Colorado. Air samples were collected onto solid adsorbent cartridges from branch enclosures on the tree species crabapple (Malus sp.), horse chestnut (Aesculus carnea, "Ft. McNair"), honey locust (Gleditsia triacanthos, "Sunburst"), and hawthorn (Crataegus laevigata, "Pauls Scarlet"). These species constitute ~ 65% of the insect-pollinated fraction of the flowering tree canopy (excluding catkin-producing trees) from the street area managed by the City of Boulder. Samples were analyzed for C10-C15 BVOC by thermal desorption and gas chromatography coupled to a flame ionization detector and a mass spectrometer (GC/FID/MS). Identified emissions and emission rates from these four tree species during the flowering phase were found to vary over a wide range. Monoterpene emissions were identified for honey locust, horse chestnut and hawthorn. Sesquiterpene emissions were observed in horse chestnut and hawthorn samples. Crabapple flowers were found to emit significant amounts of benzyl alcohol and benzaldehyde. Floral BVOC emissions increased with temperature, generally exhibiting exponential temperature dependence. Changes in BVOC speciation during and after the flowering period were observed for every tree studied. Emission rates were significantly higher during the blooming compared to the post-blooming state for crabapple and honey locust. The results were scaled to the dry mass of leaves and flowers contained in the enclosure. Only flower dry mass was accounted for crabapple emission rates as leaves appeared at the end of the flowering period. Total normalized (30 °C) monoterpene emissions from honey locust were higher during flowering (5.3 ?gC g-1 h-1) than after flowering (1.2 ?gC g-1 h-1). The total normalized BVOC emission rate from crabapple (93 ?gC g-1 h-1) during the flowering period is of the same order as isoprene emissions from oak trees, which are among the highest BVOC flowering period floral emissions observed from plants to date. These findings illustrate that during the relatively brief springtime flowering period, floral emissions constitute by far the most significant contribution to the BVOC flux from these tree species, some of which are leafless at this time. Experimental results were integrated into the MEGAN biogenic emission model and simulations were performed to estimate the contribution of floral BVOC emissions to the total urban BVOC flux during the spring flowering period. The floral BVOC emitted during this three-month simulation are equivalent to 11% of the integrated monoterpene flux for the Boulder urban area.

Baghi, R.; Helmig, D.; Guenther, A.; Duhl, T.; Daly, R.

2012-10-01

140

Biogenic Volatile Organic Compound Emission Rates From Urban Vegetation in Southeast China  

NASA Astrophysics Data System (ADS)

Currently, the country of China is growing economically at an extraordinary pace. With this growth comes an increase in emissions of anthropogenic pollutants such as hydrocarbons and nitrogen oxides from factories and vehicles. To accurately determine the effects of these pollutants on regional ozone production, and to best determine mitigation strategies, biogenic volatile organic compound (BVOC) emissions must be considered in regional atmospheric chemistry models. To date, few studies have been carried out to determine BVOC emission factors for plant species that occur in China. Considering that approximately 20% of the world's population resides in this region, it is important to develop accurate databases for BVOC emissions for the country of China. This experiment took place during May and June of 2005 and was based in the Fairy Lake Botanical Gardens (FLBG) located to the northeast of the city of Shenzhen. The city of Shenzhen is located in southeast China in Guangdong province. The city was designated a 'special economic zone' in 1980 and has experienced intense population and economic growth ever since. The dense city is surrounded by hilly rural areas of forest on three sides, and Hong Kong to the south. The purpose of the experiment was to evaluate emissions of BVOC from plants that are important to the Shenzhen region as well as to southeastern China. Over 150 species of plants were screened for emissions of isoprene and monoterpenes. These species include most of the dominant trees and shrubs planted in the Shenzhen area. Samples were collected at the FLBG as well as at various locations around the city of Shenzhen. BVOC emission samples were collected and analyzed in one of two ways. First, a Teflon enclosure was placed over a plant's branch with a constant flow of ambient air passing through the enclosure. Samples were then pumped into a Teflon bag for analysis. Samples were analyzed within 30 minutes by gas chromatography (GC) with either a photo ionization or flame ionization detector. Second, single plant leaves were placed into a light and temperature controlled leaf cuvette. Scrubbed air was passed through the cuvette, and was then collected on adsorbent cartridges for later analysis. Sample cartridges were returned to the US and analyzed by GC with a mass spectrometry for detection and identification of compounds. Results indicate a wide range of emissions for isoprene and monoterpenes. The observed emissions are compared with previous studies and taxonomic relationships are described. The emission rate measurements will be combined with detailed satellite-based landcover distribution database and used to characterize regional biogenic VOC emissions. In addition, the results of the emission survey will be used to identify low emitting plants that can be recommended for planting in subtropical urban areas.

Baker, B.; Graessli, M.; Bai, J.; Huang, A.; Li, N.; Guenther, A.

2005-12-01

141

Emissions of volatile organic compounds inferred from airborne flux measurements over a megacity  

NASA Astrophysics Data System (ADS)

Toluene and benzene are used for assessing the ability to measure disjunct eddy covariance (DEC) fluxes of Volatile Organic Compounds (VOC) using Proton Transfer Reaction Mass Spectrometry (PTR-MS) on aircraft. Statistically significant correlation between vertical wind speed and mixing ratios suggests that airborne VOC eddy covariance (EC) flux measurements using PTR-MS are feasible. City-average midday toluene and benzene fluxes are calculated to be on the order of 15.5±4.0 mg/m2/h and 4.7±2.3 mg/m2/h respectively. These values argue for an underestimation of toluene and benzene emissions in current inventories used for the Mexico City Metropolitan Area (MCMA). Wavelet analysis of instantaneous toluene and benzene measurements during city overpasses is tested as a tool to assess surface emission heterogeneity. High toluene to benzene flux ratios above an industrial district (e.g. 10 15) including the International airport (e.g. 3 5) and a mean flux (concentration) ratio of 3.2±0.5 (3.9±0.3) across Mexico City indicate that evaporative fuel and industrial emissions play an important role for the prevalence of aromatic compounds. Based on a tracer model, which was constrained by BTEX (Benzene/Toluene/Ethylbenzene/m,p,o-Xylenes) compound concentration ratios, the fuel marker methyl-tertiary-butyl-ether (MTBE) and the biomass burning marker acetonitrile (CH3CN), we show that a combination of industrial, evaporative fuel, and exhaust emissions account for >90% of all BTEX sources. Our observations suggest that biomass burning emissions play a minor role for the abundance of BTEX compounds (0 10%) in the MCMA.

Karl, T.; Apel, E.; Hodzic, A.; Riemer, D.; Blake, D.; Wiedinmyer, C.

2008-07-01

142

Emissions of volatile organic compounds inferred from airborne flux measurements over a megacity  

NASA Astrophysics Data System (ADS)

Toluene and benzene are used for assessing the ability to measure disjunct eddy covariance (DEC) fluxes of Volatile Organic Compounds (VOC) using Proton Transfer Reaction Mass Spectrometry (PTR-MS) on aircraft. Statistically significant correlation between vertical wind speed and mixing ratios suggests that airborne VOC eddy covariance (EC) flux measurements using PTR-MS are feasible. City-median midday toluene and benzene fluxes are calculated to be on the order of 14.1±4.0 mg/m2/h and 4.7±2.3 mg/m2/h, respectively. For comparison the adjusted CAM2004 emission inventory estimates toluene fluxes of 10 mg/m2/h along the footprint of the flight-track. Wavelet analysis of instantaneous toluene and benzene measurements during city overpasses is tested as a tool to assess surface emission heterogeneity. High toluene to benzene flux ratios above an industrial district (e.g. 10-15 g/g) including the International airport (e.g. 3-5 g/g) and a mean flux (concentration) ratio of 3.2±0.5 g/g (3.9±0.3 g/g) across Mexico City indicate that evaporative fuel and industrial emissions play an important role for the prevalence of aromatic compounds. Based on a tracer model, which was constrained by BTEX (BTEX- Benzene/Toluene/Ethylbenzene/m, p, o-Xylenes) compound concentration ratios, the fuel marker methyl-tertiary-butyl-ether (MTBE) and the biomass burning marker acetonitrile (CH3CN), we show that a combination of industrial, evaporative fuel, and exhaust emissions account for >87% of all BTEX sources. Our observations suggest that biomass burning emissions play a minor role for the abundance of BTEX compounds in the MCMA (2-13%).

Karl, T.; Apel, E.; Hodzic, A.; Riemer, D. D.; Blake, D. R.; Wiedinmyer, C.

2009-01-01

143

Emission of reactive terpene compounds from orange orchards and their removal by within-canopy processes  

NASA Astrophysics Data System (ADS)

VOC emission from orange orchards was determined in the framework of two field campaigns aimed at assessing the contribution of vegetation emissions to tropospheric ozone formation in the Valencia Citrus belt. Branch emission from different varieties of Citrus sinensis and Citrus Clementi was dominated by ?-caryophyllene during the summer period and by linalool during the blossoming season (April-May). Large emission of D-limonene from soil was also measured. Data collected with the enclosure technique were upscaled to determine canopy emission rates of terpene compounds. Values obtained were compared with fluxes measured by relaxed eddy accumulation. Substantial removal of ?-caryophyllene and linalool was detected during transport from the canopy into the atmospheric boundary layer. While within-canopy removal of the sesquiterpene component was fully consistent with laboratory studies indicating the high reactivity of this compound with ozone, linalool losses were more difficult to explain. Although high canopy fluxes of acetone and acetaldehyde suggested linalool decomposition by gas-phase reactivity, removal by heterogeneous chemistry seems the more likely explanation for the observed losses.

Ciccioli, Paolo; Brancaleoni, Enzo; Frattoni, Massimiliano; di Palo, Vincenzo; Valentini, Riccardo; Tirone, Giampiero; Seufert, Guenther; Bertin, Nadia; Hansen, Ute; Csiky, Olav; Lenz, Roman; Sharma, Meeta

1999-04-01

144

The effect of temperature on the emission of formaldehyde and volatile organic compounds (VOCs) from laminate flooring — case study  

Microsoft Academic Search

The effect of temperatures of 23, 29, 50°C on formaldehyde and volatile organic compounds (VOCs) emission from laminate flooring Type A (with particleboard as substrate) and Type B (with high density fibre (HDF)) was examined. At 23 and 29°C the measurements did not show any emissions of formaldehyde and very low emissions of VOCs. At a temperature of 50°C, Type

Renata Wiglusz; El?bieta Sitko; Gra?yna Nikel; Irena Jarnuszkiewicz; Barbara Igielska

2002-01-01

145

Approaches for quantifying reactive and low-volatility biogenic organic compound emissions by vegetation enclosure techniques – Part B: Applications  

Microsoft Academic Search

The focus of the studies presented in the preceding companion paper (Part A: Review) and here (Part B: Applications) is on defining representative emission rates from vegetation for determining the roles of biogenic volatile organic compound (BVOC) emissions in atmospheric chemistry and aerosol processes. The review of previously published procedures for identifying and quantifying BVOC emissions has revealed a wide

John Ortega; Detlev Helmig; Ryan W. Daly; David M. Tanner; Alex B. Guenther; Jeffrey D. Herrick

2008-01-01

146

Extended Research on Detection of Deception Using Volatile Organic Compound (VOC) Emissions  

SciTech Connect

A system that captures and analyzes volatile organic compound (VOC) emissions from skin surfaces may offer a viable alternative method to the polygraph instrument currently in use for detecting deception in U.S. government settings. Like the involuntary autonomic central nervous system response data gathered during polygraph testing, VOC emissions from the skin may provide data that can be used to detect stress caused by deception. Detecting VOCs, then, may present a noninvasive, non-intrusive method for observing, recording, and quantifying evidence of stress or emotional change.

Center for Human Reliability Studies

2006-06-01

147

Control of volatile organic compound emissions from batch processes. Alternative control techniques information document. Final report  

SciTech Connect

The purpose of this document is to provide information on alternative control techniques for volatile organic compound (VOC) emissions from batch operations. Although the control techniques information applies to batch processing in all industries, the document focuses primarily on batch processes in the following six industries: plastic materials and resins (described by Standard Industrial Classification (SIC) Code 2821), pharmaceuticals (SIC 2833 and 2834), gum and wood chemicals (SIC 2861), cyclic crudes and intermediates (SIC 2865), industrial organic chemicals (2869), and agricultural chemicals (SIC 2879). The document contains information on emissions, controls, control options, and costs that States can use in developing rules based on reasonably available control technology.

Not Available

1994-02-01

148

Patterns in volatile organic compound emissions along a savanna-rainforest gradient in central Africa  

NASA Astrophysics Data System (ADS)

In temperate regions the chemistry of the lower troposphere is known to be significantly affected by biogenic volatile organic compounds (VOCs) emitted by plants. The chemistry of the lower troposphere over the tropics, however, is poorly understood, in part because of the considerable uncertainties in VOC emissions from tropical ecosystems. Present global VOC models predict that base emissions of isoprene from tropical rainforests are considerably higher than from savannas. These global models of VOC emissions which rely mainly on species inventories are useful, but significant improvement might be made with more ecologically based models of VOC emissions by plants. Ecosystems along a successional transect from woodland savanna to primary rainforest in central Africa were characterized for species composition and vegetation abundance using ground surveys and remotely sensed data. A total of 336 species (mostly trees) at 13 sites were recorded, and 208 of these were measured for VOC emissions at near-optimal light and temperature conditions using a leaf cuvette and hand-held photoionization detector (PID). A subset of 59 species was also sampled using conventional VOC emission techniques in order to validate the PID technique. Results of ecological and VOC emission surveys indicate both phylogenetic and successional patterns along the savanna-rainforest transect. Genera and families of trees which tend to emit isoprene include Lophira, Irvingia, Albizia, Artocarpus, Ficus, Pterocarpus, Caesalpiniaceae, Arecaceae, and Moraceae. Other taxa tend to contain stored VOCs (Annonaceae and Asteraceae). Successional patterns suggest that isoprene emissions are highest in the relatively early successional Isoberlinia forest communities and progressively decrease in the later successional secondary and primary rainforest communities. Stored VOCs appear to increase along the savanna-rainforest succession, but these data are more tentative. These findings are consistent with successional patterns of isoprene and terpene fluxes in North American forests and highlight the feasibility of constructing better predictive models of VOC emissions.

Klinger, L. F.; Greenburg, J.; Guenther, A.; Tyndall, G.; Zimmerman, P.; M'bangui, M.; Moutsamboté, J.-M.; Kenfack, D.

1998-01-01

149

Emissions of volatile organic compounds from new carpets measured in a large-scale environmental chamber  

SciTech Connect

This study was undertaken to quantify the emissions of volatile organic compounds (VOCs) released by new carpets. Samples of four typical carpets, including two with styrene-butadiene rubber (SBR) latex adhesive and two with different backings, were collected from the finish lines at manufacturers' mills. Individual VOCs released from these samples were identified, and their concentrations, emission rates and mass emissions were measured under simulated indoor conditions in a 20 m[sup 3] environmental chamber over one week periods. Concentrations and emission rates of VOCs emitted by a new SBR carpet were also measured in a house. The carpets emitted a variety of VOCs. The two SBR carpets primarily emitted 4-phenylcyclohexene (4-PCH), the source of [open quotes]new carpet[close quotes] odor, and styrene. The concentrations and emission rates of 4-PCH were similar for the two carpets, while the styrene values varied significantly. The carpet with a polyvinyl chloride backing emitted formaldehyde, vinyl acetate, isooctane, 1,2-propanediol, and 2-ethyl-1-hexanol. Of these, vinyl acetate and propanediol had the highest concentrations and emission rates. The carpet with a polyurethane backing primarily emitted butylated hydroxytoluene. With the exception of formaldehyde, little is known about the health effects of these VOCs at low concentrations. 23 refs., 3 figs., 6 tabs.

Hodgson, A.T.; Wooley, J.D.; Daisey, J.M. (Lawrence Berkeley Lab., CA (United States))

1993-03-01

150

Emissions of volatile organic compounds from new carpets measured in a large-scale environmental chamber.  

PubMed

This study was undertaken to quantify the emissions of volatile organic compounds (VOCs) released by new carpets. Samples of four typical carpets, including two with styrene-butadiene rubber (SBR) latex adhesive and two with different backings, were collected from the finish lines at manufacturers' mills. Individual VOCs released from these samples were identified, and their concentrations, emission rates and mass emissions were measured under simulated indoor conditions in a 20 m3 environmental chamber over one week periods. Concentrations and emission rates of VOCs emitted by a new SBR carpet were also measured in a house. The carpets emitted a variety of VOCs. The two SBR carpets primarily emitted 4-phenylcyclohexene (4-PCH), the source of "new carpet" odor, and styrene. The concentrations and emission rates of 4-PCH were similar for the two carpets, while the styrene values varied significantly. The carpet with a polyvinyl chloride backing emitted formaldehyde, vinyl acetate, isooctane, 1,2-propanediol, and 2-ethyl-1-hexanol. Of these, vinyl acetate and propanediol had the highest concentrations and emission rates. The carpet with a polyurethane backing primarily emitted butylated hydroxytoluene. With the exception of formaldehyde, little is known about the health effects of these VOCs at low concentrations. PMID:8457318

Hodgson, A T; Wooley, J D; Daisey, J M

1993-03-01

151

Carbonyl compound emissions from passenger cars fueled with methanol\\/gasoline blends  

Microsoft Academic Search

Carbonyl compound emissions from two passenger cars fueled with different methanol\\/gasoline blends (M15 and M100) and operated with three-way catalytic converters (TWC) were investigated. The tests were performed on a chassis dynamometer with constant volume sampling over the New European Driving Cycle (NEDC). Carbonyls were trapped on dinitrophenylhydrazine (DNPH) cartridges. The hydrazones formed on the cartridge were analyzed by means

Hong Zhao; Yunshan Ge; Chunxiao Hao; Xiukun Han; Mingliang Fu; Linxiao Yu; Asad Naeem Shah

2010-01-01

152

Emission of sulfur-bearing compounds from motor vehicle and aircraft engines. A report to congress  

Microsoft Academic Search

This report was generated in response to section 403(g) of The Clean Air Act as amended August, 1977. The report covers (1) a review of emission factors for HâSOâ, SOâ, sulfate, HâS, and carbonyl sulfide from motor vehicles, motor vehicle engines and aircraft engines; (2) a review of the known effects on health and welfare of these compounds; (3) the

Kawecki

1978-01-01

153

Investigation of carbonyl compounds in air from various industrial emission sources.  

PubMed

The emission concentrations of carbonyl compounds in air were quantified from a total of 195 man-made source units within 77 individual companies at a large industrial complex in Korea. The measurement data were evaluated both by absolute magnitude of concentration and by their relative contribution to malodor formation such as malodor degree (MD) derived from empirical formula. It was found that formaldehyde exhibited the highest mean concentration of 323ppb with a median value of 28.2ppb, while butyraldehyde recorded the highest contribution to odor formation with an MD value of 3.5 (186 (mean) and 9.8ppb (median)). The relative intensity of carbonyl emission, when compared by the sum of MD, showed the highest source strength from the food and beverage (industry sector) and scrubber (source unit). A comprehensive evaluation of the carbonyl data from diverse industrial facilities thus allowed us to describe the fundamental patterns of their emission. PMID:17765288

Kim, Ki-Hyun; Hong, Yoon-Jung; Pal, Raktim; Jeon, Eui-Chan; Koo, Yoon-Seo; Sunwoo, Young

2007-08-31

154

Nitrogen compounds emission and deposition in West African ecosystems: comparison between wet and dry savanna  

NASA Astrophysics Data System (ADS)

Surface emission and deposition fluxes of reactive nitrogen compounds have been studied in five sites of West Africa during the period 2002 to 2007. Measurements of N deposition fluxes have been performed in IDAF sites representative of main west and central African ecosystems, i.e., 3 stations in dry savanna ecosystems (from 15° N to 12° N), and 2 stations in wet savanna ecosystems (from 9° N to 6° N). Dry deposition fluxes are calculated from surface measurements of NO2, HNO3 and NH3 concentrations and simulated deposition velocities, and wet deposition fluxes are calculated from NH4+ and NO3- concentration in samples of rain. Emission fluxes are evaluated including simulated NO biogenic emission from soils, emissions of NOx and NH3 from biomass burning and domestic fires, and volatilization of NH3 from animal excreta. This paper is a tentative to understand the eventual impact of the monsoon variability from year to year, with the natural variability of local sources, on the emission and deposition N fluxes, and to compare these evolutions between dry and wet savanna ecosystems. In dry savanna ecosystems where the rain season lasts mainly from June to September, the occurence of rain correlates with the beginning of emission and deposition fluxes. This link is less obvious in wet savanna ecosystems (wet season mainly from May to October), where the surface is less submitted to drastic changes in terms of water content. Whatever the location, the natural variability of rain from year to year does not exceed 15 %, and the variability of emission and deposition magnitude ranges between 15 % and 28 %. While quasi providing the same total N budget, and due to the presence of different types of soils and vegetation, wet and dry savanna do not present the same distribution in emission and deposition fluxes contributions: in dry savanna, the emission is dominated by ammonia volatilization, and the deposition is dominated by the dry contribution. In wet savanna, emission is equally distributed between ammonia volatilization, emissions from biomass burning and natural NO emissions from soils, and wet and dry deposition are equivalent. Due to the scarcity of available data on the African continent, and despite the numerous uncertainties resulting from the different calculations and assumptions, this work is a combination of data from different origins (surface measurements, satellite and modelling) to document the atmospheric Nitrogen cycle in tropical regions.

Delon, C.; Galy-Lacaux, C.; Adon, M.; Liousse, C.; Serça, D.; Diop, B.; Akpo, A.

2012-01-01

155

Estimation of volatile organic compound emissions for Europe using data assimilation  

NASA Astrophysics Data System (ADS)

The emissions of non-methane volatile organic compounds (VOCs) over western Europe for the year 2005 are estimated via inverse modelling by assimilation of in situ observations of concentration and then subsequently compared to a standard emission inventory. The study focuses on 15 VOC species: five aromatics, six alkanes, two alkenes, one alkyne and one biogenic diene. The inversion relies on a validated fast adjoint of the chemical transport model used to simulate the fate and transport of these VOCs. The assimilated ground-based measurements over Europe are provided by the European Monitoring and Evaluation Programme (EMEP) network. The background emission errors and the prior observational errors are estimated by maximum-likelihood approaches. The positivity assumption on the VOC emission fluxes is pivotal for a successful inversion, and this maximum-likelihood approach consistently accounts for the positivity of the fluxes. For most species, the retrieved emissions lead to a significant reduction of the bias, which underlines the misfit between the standard inventories and the observed concentrations. The results are validated through a forecast test and a cross-validation test. An estimation of the posterior uncertainty is also provided. It is shown that the statistically consistent non-Gaussian approach based on a reliable estimation of the errors offers the best performance. The efficiency in correcting the inventory depends on the lifetime of the VOCs and the accuracy of the boundary conditions. In particular, it is shown that the use of in situ observations using a sparse monitoring network to estimate emissions of isoprene is inadequate because its short chemical lifetime significantly limits the spatial radius of influence of the monitoring data. For species with a longer lifetime (a few days), successful, albeit partial, emission corrections can reach regions hundreds of kilometres away from the stations. Domain-wide corrections of the emission inventories of some VOCs are significant, with underestimations of the order of a factor of 2 for propane, ethane, ethylene and acetylene.

Koohkan, M. R.; Bocquet, M.; Roustan, Y.; Kim, Y.; Seigneur, C.

2013-06-01

156

Identification of polycyclic aromatic compounds in mutagenic emissions from steel casting.  

PubMed

Workers in ferrous foundries show increased risk of lung cancer. In the steel casting process hot metal is poured into sand moulds solidified with organic binders, producing a plume of smoke containing a variety of organic compounds and showing strong mutagenicity in the Salmonella/S9 assay. We have collected the emissions produced when steel is poured into an experimental sand mould solidified with oil, clay and cereal, a widely used binder system. The organic constituents of these emissions have been fractionated by preparative reverse-phase high performance liquid chromatography (HPLC) and mutagenic fractions have been analysed by capillary column gas chromatography/mass spectrometry (GC/MS). Of the 65 compounds for which mass spectra are reported, 54 have been tentatively identified as alkyl derivatives of polycyclic aromatic compounds. Many compounds of this class are known to be carcinogenic and mutagenic. In addition, several unsubstituted polycyclic aromatic hydrocarbons, including the carcinogenic benz[a]anthracene and benzo[a]pyrene, were found to be present. PMID:3160400

Quilliam, M A; Lant, M S; Kaiser-Farrell, C; McCalla, D R; Sheldrake, C P; Kerr, A A; Lockington, J N; Gibson, E S

1985-04-01

157

Investigating Sources and Emissions of Volatile Organic Compounds in California's San Joaquin Valley  

NASA Astrophysics Data System (ADS)

Emissions of Volatile Organic Compounds (VOCs) are regulated both as primary air pollutants and as precursors to the formation of secondary organic aerosol and tropospheric ozone. The San Joaquin Valley, a non-attainment area for ozone and PM2.5, contains a variety of point, area, and mobile VOC sources that contribute to both primary and secondary pollution. Using ambient measurements of over 100 different VOCs and Intermediate Volatility Organic Compounds (IVOCs) made at multiple field sites, we assess the magnitude and importance of various VOC sources in the San Joaquin Valley. Hourly measurements were made during the spring and summer of 2010 via in-situ gas chromatography in Bakersfield, CA as part of the CalNex experiment and also at a rural site located 100 km north of Bakersfield. Additionally, in-situ measurements of fresh motor vehicle exhaust were made in Oakland's Caldecott tunnel during the summer of 2010. Measurements include a broad array of anthropogenic and biogenic VOCs ranging in size from 1 to 17 carbon atoms, including many compounds with functional groups or substituents (e.g. aldehydes, ketones, alcohols, halogens, sulfur, & nitrogen). Using statistical methods of source apportionment, covariance, source receptor modeling, and air parcel back trajectories, we assess the impact of various sources on observed VOC concentrations at our field sites in the San Joaquin Valley. Prevalent sources include gasoline and diesel-vehicle exhaust, petroleum extraction/refining, biogenic emissions from agricultural crops and natural vegetation, and emissions from dairy operations and animal husbandry. We use measurements of fresh motor vehicle emissions from the Caldecott tunnel to constrain apportionment of gasoline and diesel-related VOCs and IVOCs in the San Joaquin Valley. Initial results from Bakersfield show substantial influence from local anthropogenic VOC sources, but there is evidence for transport of emissions from both anthropogenic and biogenic sources elsewhere in the region. For example, large biogenic sources appear to be regional rather than local since concentrations of isoprene peak in the late afternoon/evening suggesting transport from northern parts of the valley. We observed elevated concentrations of numerous alcohols and carbonyls in the San Joaquin Valley; for example mixing ratios of ethanol and acetone at the Bakersfield supersite had inner quartile ranges of 1.2-9.4 ppbv and 0.58-1.6 ppbv, with daytime averages near 2 and 1 ppbv, respectively. Additionally, we assess the sources and emissions of the IVOCs observed in the San Joaquin Valley, which include polycyclic aromatic hydrocarbons, large biogenic compounds, and high molecular weight alkanes and aromatics.

Gentner, D. R.; Harley, R. A.; Weber, R.; Karlik, J. F.; Goldstein, A. H.

2011-12-01

158

The Clean Air Act and volatile organic compounds: Did plants reduce their health-indexed air emissions or shift their emissions into other media?  

Microsoft Academic Search

Do plants respond to medium-specific regulation of pollutants by reducing their emissions into that medium or by shifting their emissions into other media? I examine the impact of the U.S. Clean Air Act's ground-level ozone regulations (CAA) on the chemical manufacturing sector's health-indexed emissions of volatile organic compounds (VOC) that are reportable to the Toxic Release Inventory. I construct a

Shanti Gamper-Rabindran

2009-01-01

159

Emission of volatile organic sulfur compounds (VOSCs) during aerobic decomposition of food wastes  

NASA Astrophysics Data System (ADS)

Food wastes collected from typical urban residential communities were investigated for the emission of volatile organic sulfur compounds (VOSCs) during laboratory-controlled aerobic decomposition in an incubator for a period of 41 days. Emission of VOSCs from the food wastes totaled 409.9 mg kg -1 (dry weight), and dimethyl disulfide (DMDS), dimethyl sulfide (DMS), methyl 2-propenyl disulfide, carbonyl sulfide and methyl 1-propenyl sulfide were the five most abundant VOSCs, with shares of 75.5%, 13.5%, 4.8%, 2.2% and 1.3% in total 15 VOSCs released, respectively. The emission fluxes of major VOSCs were very low at the beginning (day 0). They peaked at days 2-4 and then decreased sharply until they leveled off after 10 days of incubation. For most VOSCs, over 95% of their emission occurred in the first 10 days. The time series of VOSC emission fluxes, as well as their significant correlation with internal food waste temperature ( p < 0.05) during incubation, suggested that production of VOSC species was induced mainly by microbial activities during the aerobic decomposition instead of as inherited. Released VOSCs accounted for 5.3% of sulfur content in the food wastes, implying that during aerobic decomposition considerable portion of sulfur in food wastes would be released into the atmosphere as VOSCs, primarily as DMDS, which is very short-lived in the atmosphere and thus usually less considered in the sources and sinks of reduced sulfur gases.

Wu, Ting; Wang, Xinming; Li, Dejun; Yi, Zhigang

2010-12-01

160

An enclosure technique for measuring nonmethane organic compound emissions from grasslands  

SciTech Connect

A static chamber technique for measuring emissions of nonmethane organic compounds (NMOCs) from soil surfaces and herbaceous vegetation in a natural setting has been developed. The technique involves the insertion of a polymethyl methacrylate frame into the ground. A polycarbonate chamber is placed in a water-containing trough on the frame to seal the chamber to the surface. The soil surface and vegetation are covered for various lengths of time, and samples of the chamber are are passively collected in preevacuated stainless steel canisters. The samples are analyzed in the laboratory by a whole-air cryogenic-preconcentration/high-resolution gas chromatographic technique with flame ionization detection. Changes in the concentrations of the NMOCs with time in the chamber are used to derive emission rates. The technique is sensitive and precise, but the occasional observation of nonlinear changes in NMOC concentrations in the chamber with the length of the covering period limits the accuracy of emission rates derived by this technique. Despite this limitation, the method is effective for identifying NMOC emissions and investigating seasonal variations of emission rates. 46 refs., 3 figs., 5 tabs.

Fukui, Yoshiko; Doskey, P.V. [Argonne National Lab., IL (United States)

1996-05-01

161

Nitrogen compounds emission and deposition in West African ecosystems: comparison between wet and dry savanna  

NASA Astrophysics Data System (ADS)

Surface emission and deposition fluxes of nitrogen compounds have been studied in five sites of West Africa during the period 2002 to 2007. Measurements of N deposition fluxes have been performed in IDAF sites representative of main west and central African ecosystems, i.e., 3 stations in dry savanna ecosystems (from 15° N to 12° N), and 2 stations in wet savanna ecosystems (from 9° N to 6° N). Dry deposition fluxes are calculated from surface measurements of NO2, HNO3 and NH3 concentrations and simulated deposition velocities, and wet deposition fluxes are calculated from NH4+ and NO3- concentration in samples of rain. Emission fluxes are evaluated including simulated NO biogenic emission from soils, emissions of NOx and NH3 from biomass burning and domestic fires, and volatilization of NH3 from animal excreta. This paper is a tentative to link the variability of rain and the intra and inter annual variability of emission and deposition processes, and to compare these evolutions between dry and wet savanna ecosystems. In dry savanna ecosystems where the rain season lasts mainly from June to September, the occurence of rain correlates with the beginning of emission and deposition fluxes. This link is less obvious in wet savanna ecosystems (wet season mainly from May to October), where the surface is less submitted to drastic changes in terms of water content. Whatever the location, the natural variability of rain from year to year does not exceed 15 %, and does not induce a strong impact on emission and deposition magnitude. Due to the scarcity of available data on the African continent, it is of first importance to combine data from different origins (surface measurements, satellite and modelling) to document the atmospheric Nitrogen cycle in these tropical regions.

Delon, C.; Galy-Lacaux, C.; Adon, M.; Liousse, C.; Serça, D.; Diop, B.; Akpo, A.

2011-07-01

162

Estimation of volatile organic compound emissions for Europe using data assimilation  

NASA Astrophysics Data System (ADS)

The emission of volatile organic compounds (VOCs) over western Europe for the year 2005 are estimated via inverse modelling, by assimilation of in situ observations of concentration and compared to a standard emission inventory. The study focuses on fifteen VOC species: five aromatics, six alkanes, two alkenes, one alkyne and one biogenic diene. The inversion relies on a validated fast adjoint of the chemistry transport model used to simulate the fate and transport of these VOCs. The assimilated ground-based measurements over Europe are provided by the European Monitoring and Evaluation Programme (EMEP) network. The background emissions errors and the prior observational errors are estimated by maximum likelihood approaches. The positivity assumptions on the VOC emission fluxes is pivotal for a successful inversion and this maximum likelihood approach consistently accounts for the positivity of the fluxes. For most species, the retrieval leads to a significant reduction of the bias, which underlines the misfit between the standard inventories and the observed concentrations. The results are validated through a forecast test and a cross-validation test. It is shown that the statistically consistent non-Gaussian approach based on a reliable estimation of the errors offers the best performance. The efficiency in correcting the inventory depends on the lifetime of the VOCs. In particular, it is shown that the use of in-situ observations using a sparse monitoring network to estimate emissions of isoprene is inadequate because its short chemical lifetime significantly limits the spatial radius of influence of the monitoring data. For species with longer lifetime (a few days), successful, albeit partial, emission corrections can reach regions hundreds of kilometres away from the stations. Domainwide corrections of the emissions inventories of some VOCs are significant, with underestimations on order of a factor of two of propane, ethane, ethylene and acetylene.

Koohkan, M. R.; Bocquet, M.; Roustan, Y.; Kim, Y.; Seigneur, C.

2012-12-01

163

Investigation and estimation of emission sources of 54 volatile organic compounds in ambient air in Tokyo  

NASA Astrophysics Data System (ADS)

Atmospheric concentrations of 52 hydrocarbons and two aldehydes at roadside and urban sites in Tokyo metropolitan area, Japan were analyzed using GC/MS and HPLC. Monthly sampling was conducted during April 2003-March 2005. Annual average concentrations of individual volatile organic compounds (VOCs) at the roadside site were 1.7-1.9 times higher than at the urban site, suggesting that vehicle exhausts strongly affect VOC concentrations. Since high temperatures and under the stagnant meteorological conditions might increase VOC concentrations in air, the levels of alkanes, alkenes, and aromatic hydrocarbons rose in summer and autumn in 2003 and 2004. The VOCs concentrations against benzene (VOCs/Bz) suggest classifying three groups of VOCs: those mainly from mobile emission sources, those mainly from stationary sources, and those comprising unstable compounds such as aldehydes and 1,3-butadiene. The VOC/Bz technique was applied to registered VOC data from the Pollutant Release and Transfer Register (PRTR). Results show that these VOCs in ambient air in Tokyo reflect the PRTR estimated release amounts. The VOC/Bz technique based on environmental monitoring data is useful to estimate non-registered VOCs such as butane and isopentane. Results show the possibility of estimating emission sources using VOC/Bz ratios from environmental monitoring data, even when sufficient information on the emission sources are not available.

Hoshi, Jun-ya; Amano, Saeko; Sasaki, Yuko; Korenaga, Takashi

164

Emission of volatile organic compounds from religious and ritual activities in India.  

PubMed

Worshipping activity is a customary practice related with many religions and cultures in various Asian countries, including India. Smoke from incense burning in religious and ritual places produces a large number of health-damaging and carcinogenic air pollutants include volatile organic compounds (VOCs) such as formaldehyde, benzene, 1,3 butadiene, styrene, etc. This study evaluates real-world VOCs emission conditions in contrast to other studies that examined emissions from specific types of incense or biomass material. Sampling was conducted at four different religious places in Raipur City, District Raipur, Chhattisgarh, India: (1) Hindu temples, (2) Muslim graveyards (holy shrines), (3) Buddhist temples, and (4) marriage ceremony. Concentrations of selected VOCs, respirable particulate matter (aerodynamic diameter, <5 ?m), carbon dioxide, and carbon monoxide were sampled from the smoke plumes. Benzene has shown highest emission factor (EF) among selected volatile organic compounds in all places. All the selected religious and ritual venues have shown different pattern of VOC EFs compared to laboratory-based controlled chamber studies. PMID:23709262

Dewangan, Shippi; Chakrabarty, Rajan; Zielinska, Barbara; Pervez, Shamsh

2013-05-25

165

Observations of volatile organic compounds during ARCTAS - Part 1: Biomass burning emissions and plume enhancements  

NASA Astrophysics Data System (ADS)

Mixing ratios of a large number of volatile organic compounds (VOCs) were observed by the Trace Organic Gas Analyzer (TOGA) on board the NASA DC-8 as part of the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) field campaign. Many of these VOCs were observed concurrently by one or both of two other VOC measurement techniques on board the DC-8: proton-transfer-reaction mass spectrometry (PTR-MS) and whole air canister sampling (WAS). A comparison of these measurements to the data from TOGA indicates good agreement for the majority of co-measured VOCs. The ARCTAS study, which included both spring and summer deployments, provided opportunities to sample a large number of biomass burning (BB) plumes with origins in Asia, California and Central Canada, ranging from very recent emissions to plumes aged one week or more. For this analysis, identified BB plumes were grouped by flight, source region and, in some cases, time of day, generating 40 individual plume groups, each consisting of one or more BB plume interceptions. Normalized excess mixing ratios (EMRs) to CO were determined for each of the 40 plume groups for up to 19 different VOCs or VOC groups, many of which show significant variability, even within relatively fresh plumes. This variability demonstrates the importance of assessing BB plumes both regionally and temporally, as emissions can vary from region to region, and even within a fire over time. Comparisons with literature confirm that variability of EMRs to CO over an order of magnitude for many VOCs is consistent with previous observations. However, this variability is often diluted in the literature when individual observations are averaged to generate an overall regional EMR from a particular study. Previous studies give the impression that emission ratios are generally consistent within a given region, and this is not necessarily the case, as our results show. For some VOCs, earlier assumptions may lead to significant under-prediction of emissions in fire emissions inventories. Notably, though variable between plumes, observed EMRs of individual light alkanes are highly correlated within BB emissions. Using the NCAR master mechanism chemical box model initialized with concentrations based on two observed scenarios, i.e., fresh Canadian BB and fresh Californian BB, both plumes are expected to experience primarily decreases in oxygenated VOCs during the first 2.5 days, such that any production in the plumes of these compounds is less than the chemical loss. Comparisons of the modeled EMRs to the observed EMRs from BB plumes estimated to be three days in age or less indicate overall good agreement and, for most compounds, no significant difference between BB plumes in these two regions.

Hornbrook, R. S.; Blake, D. R.; Diskin, G. S.; Fuelberg, H. E.; Meinardi, S.; Mikoviny, T.; Sachse, G. W.; Vay, S. A.; Weinheimer, A. J.; Wiedinmyer, C.; Wisthaler, A.; Hills, A.; Riemer, D. D.; Apel, E. C.

2011-05-01

166

A NONSTEADY-STATE ANALYTICAL MODEL TO PREDICT GASEOUS EMISSIONS OF VOLATILE ORGANIC COMPOUNDS FROM LANDFILLS. (R825689C072)  

EPA Science Inventory

Abstract A general mathematical model is developed to predict emissions of volatile organic compounds (VOCs) from hazardous or sanitary landfills. The model is analytical in nature and includes important mechanisms occurring in unsaturated subsurface landfill environme...

167

PROJECTION METHODOLOGY FOR FUTURE STATE LEVEL VOLATILE ORGANIC COMPOUND EMISSIONS FROM STATIONARY SOURCES (VERSION 1.8)  

EPA Science Inventory

The report presents the model framework used to estimate state level and national future volatile organic compound (VOC) emissions and control costs for stationary industrial and utility sources. The framework involves a projection approach using the 1980 National Acid Precipitat...

168

Study Estimating VOC (Volatile Organic Compound) Emissions from the Calumet Sewage Treatment Plant in the Chicago Area.  

National Technical Information Service (NTIS)

The emission of volatile organic compounds (VOCs) from Publicly Owned Sewage Treatment Works (POTWs) might pose an air-pollution hazard, because many VOCs are known to create a human health hazard with continuous exposure. This study estimated the annual ...

B. E. Rittmann E. Namkung

1986-01-01

169

Carbonyl compound emissions from passenger cars fueled with methanol/gasoline blends.  

PubMed

Carbonyl compound emissions from two passenger cars fueled with different methanol/gasoline blends (M15 and M100) and operated with three-way catalytic converters (TWC) were investigated. The tests were performed on a chassis dynamometer with constant volume sampling over the New European Driving Cycle (NEDC). Carbonyls were trapped on dinitrophenylhydrazine (DNPH) cartridges. The hydrazones formed on the cartridge were analyzed by means of high-performance liquid chromatography (HPLC) and detected with a variable wavelength detector. The results show that when cars were fueled with methanol/gasoline blends, carbon monoxide (CO) and total hydrocarbon (THC) emissions decreased by 9-21% and 1-55% respectively, while nitrogen oxide (NO(x)) emissions increased by 175-233%. Compared with gasoline vehicles, formaldehyde emissions with M15 and M100 were two and four times higher respectively, and total carbonyls with M15 and M100 increased by 3% and 104% respectively. With the use of the new TWC, both regulated gas pollutants and formaldehyde decreased. The new TWC caused a decrease of 5% and 31% in formaldehyde concentration for M15 and M100, respectively. Specific reactivity (SR) with the new TWC was reduced from 5.92 to 5.72 for M15 and from 7.00 to 6.93 for M100, indicating that M15 and M100 with the new TWC were friendlier to the environment. PMID:20510438

Zhao, Hong; Ge, Yunshan; Hao, Chunxiao; Han, Xiukun; Fu, Mingliang; Yu, Linxiao; Shah, Asad Naeem

2010-05-26

170

Temperature dependence of volatile organic compound evaporative emissions from motor vehicles  

NASA Astrophysics Data System (ADS)

A chemical mass balance approach is used to determine the relative contributions of evaporative versus tailpipe sources to motor vehicle volatile organic compound (VOC) emissions. Contributions were determined by reconciling time-resolved ambient VOC concentrations measured downwind of Sacramento, California, in summer 2001 with source speciation profiles. A composite liquid fuel speciation profile was determined from gasoline samples collected at Sacramento area service stations. Vapor-liquid equilibrium relationships were used to determine the corresponding headspace vapor composition. VOC concentrations measured in a highway tunnel were used to define the composition of running vehicle emissions. The chemical mass balance analysis indicated that headspace vapor contributions ranged from 7 to 29% of total vehicle-related VOC depending on time of day and day of week, with a mean daytime contribution of 17.0 ± 0.9% (mean ± 95% CI). A positive association between the headspace vapor contribution and ambient air temperature was found for afternoon hours. We estimate a 6.5 ± 2.5% increase in vapor pressure-driven evaporative emissions and at least a 1.3 ± 0.4% increase in daily total (exhaust plus evaporative) VOC emissions from motor vehicles per degree Celsius increase in maximum temperature.

Rubin, Juli I.; Kean, Andrew J.; Harley, Robert A.; Millet, Dylan B.; Goldstein, Allen H.

2006-02-01

171

Vehicular emission of volatile organic compounds (VOCs) from a tunnel study in Hong Kong  

NASA Astrophysics Data System (ADS)

Vehicle emissions of VOCs were determined in summer and winter of 2003 at the Shing Mun Tunnel, Hong Kong. One hundred and ten VOCs were quantified in this study. The average concentration of the total measured VOCs at the inlet and outlet of the tunnel were 81 250 pptv and 117 850 pptv, respectively. Among the 110 compounds analyzed, ethene, ethyne and toluene were the most abundant species in the tunnel. The total measured VOC emission factors ranged from 67 mg veh-1 km-1 to 148 mg veh-1 km-1, with an average of 115 mg veh-1 km-1. The five most abundant VOCs observed in the tunnel were, in decreasing order, ethene, toluene, n-butane, propane and i-pentane. These five most abundant species contributed over 38% of the total measured VOCs emitted. The high propane and n-butane emissions were found to be associated with LPG-fueled taxi. And fair correlations were observed between marker species (ethene, i-pentane, n-nonane, BTEX) with fractions of gasoline-fueled or diesel-fueled vehicles. Moreover, ethene, ethyne, and propene are the key species that were abundant in the tunnel but not in gasoline vapors or LPG. In order to evaluate the ozone formation potential emissions in Hong Kong, the maximum increment reactivity is calculated. It was found that about 568 mg of O3 is induced by per vehicle per kilometer traveled. Among them, ethene, propene and toluene contribute most to the ozone-formation reactivity.

Ho, K. F.; Lee, S. C.; Ho, W. K.; Blake, D. R.; Cheng, Y.; Li, Y. S.; Fung, K.; Louie, P. K. K.; Park, D.

2009-06-01

172

Approaches for quantifying reactive and low-volatility biogenic organic compound emissions by vegetation enclosure techniquest -- Part B: Applications  

EPA Science Inventory

The focus of the studies presented in the preceding companion paper (Part A: Review) and here (PArt B: Applications) is on defining representative emission rates from vegetation for determining the roles of biogenic volatile organic compound (BVOC) emissions in atmospheric chemis...

173

VOLATILE ORGANIC COMPOUND EMISSIONS FROM LATEX PAINT-PART 2. TEST HOUSE STUDIES AND INDOOR AIR QUALITY (IAQ) MODELING  

EPA Science Inventory

Emission models developed using small chamber data were combined with an Indoor Air Quality (IAQ) model to analyze the impact of volatile organic compound (VOC) emissions from latex paint on indoor environments. Test house experiments were conducted to verify the IAQ model's pred...

174

Development and evaluation of compounds for imaging of ?-amyloid plaque by means of positron emission tomography  

Microsoft Academic Search

Purpose  The proof of concept for in vivo targeting of ?-amyloid plaques (A?) in patients with Alzheimer’s disease (AD) by means of\\u000a nuclear imaging methods has been shown in recent clinical studies.\\u000a \\u000a \\u000a \\u000a Methods  For positron emission tomography (PET), the five compounds [11C]PIB, 3?[18F]FPIB, [18F]FDDNP, [11C]SB-13 and [18F]F-SB-13 have been developed by a formal charge neutralisation of agents used for staining of AD

Gjermund Henriksen; Behrooz H. Yousefi; Alexander Drzezga; Hans-Jürgen Wester

2008-01-01

175

Study of the dynamics of induced emission from organic compounds under pulsed laser pumping  

NASA Astrophysics Data System (ADS)

A numerical modeling technique has been used to study the dynamics of generation of induced emission in a series of organic compounds: coumarin (7-amino-4-methylcoumarin and 6-bromo-3-(4-(4-bromophenyl) thiazole-2-yl)-coumarin) and rhodamine 6G. The effect of concentration on the lasing wavelength (rhodamine 6G) has been elucidated, along with the lasing capability of 7-amino-4-methylcoumarin at different pump pulse durations. The reasons for the absence of lasing in 6-bromo-3-(4-(4-bromophenyl)thiazole-2-yl)-coumarin have been investigated.

Kopylova, T. N.; Artyukhov, V. Ya.; Nikonov, S. Yu.; Gadirov, R. M.

2013-09-01

176

Emission of complex fragments for compound nuclei formed far from the stability line for A{approx}120  

SciTech Connect

Experiments and calculations are presented for the emission of complex fragments (Z>2) from compound nuclei around mass 120 and for bombarding energies below 15 MeV/nucleon. It is shown that a strong enhancement in the emission of complex fragments (especially for Z=6) is expected for compound nuclei formed close or at the N=Z line. Several predictions are given that could be tested with the radioactive beams soon to be available. Also results from a recent experiment that utilizes the emission of complex fragments for {gamma}-ray nuclear spectroscopy studies are presented.

Gomez Del Campo, J.

1996-10-01

177

Qualitative and quantitative characterization of volatile organic compound emissions from cut grass.  

PubMed

Mechanical wounding of plants triggers the release of a blend of reactive biogenic volatile organic compounds (BVOCs). During and after mowing and harvesting of managed grasslands, significant BVOC emissions have the potential to alter the physical and chemical properties of the atmosphere and lead to ozone and aerosol formation with consequences for regional air quality. We show that the amount and composition of BVOCs emitted per unit dry weight of plant material is comparable between laboratory enclosure measurements of artificially severed grassland plant species and in situ ecosystem-scale flux measurements above a temperate mountain grassland during and after periodic mowing and harvesting. The investigated grassland ecosystem emitted annually up to 130 mg carbon m(-2) in response to cutting and drying, the largest part being consistently represented by methanol and a blend of green leaf volatiles (GLV). In addition, we report the plant species-specific emission of furfural, terpenoid-like compounds (e.g., camphor), and sesquiterpenes from cut plant material, which may be used as tracers for the presence of given plant species in the ecosystem. PMID:22409212

Brilli, Federico; Hörtnagl, Lukas; Bamberger, Ines; Schnitzhofer, Ralf; Ruuskanen, Taina M; Hansel, Armin; Loreto, Francesco; Wohlfahrt, Georg

2012-03-21

178

Technology status report: Off-gas treatment technologies for chlorinated volatile organic compound air emissions  

SciTech Connect

The purpose of this document is to review technologies for treatment of air streams that contain chlorinated volatile organic compounds (CVOCS) and to describe a Department of Energy Office of Technology Development program that is planned to demonstrate innovative technologies for the abatement of CVOC emissions. This report describes the first phase of testing of off-gas treatment technologies. At least one more phase of testing is planned. Guidance for the preparation of this document was provided by a predecisional draft outline issued by the Department of Energy`s Office of Technology Development. The report is intended to evaluate the technical and regulatory aspects, public acceptance, and estimated costs of technologies selected for development and testing. These technologies are compared to currently practiced or baseline methods for treatment of CVOC-laden airstreams. A brief overview is provided rather than detailed cost and data comparisons because many of these technologies have not yet been field tested. A description of other promising technologies for the treatment of CVOC emissions is also included. Trichloroethylene (TCE) and perchloroethylene (PCE) were used for industrial cleaning and solvent applications for several decades. These chemicals can be classified as CVOCS. As a result of past standard disposal practices, these types of compounds are persistent groundwater and soil contaminants throughout the United States and the Department of Energy Complex.

Rossabi, J.; Haselow, J.S.

1992-04-15

179

Technology status report: Off-gas treatment technologies for chlorinated volatile organic compound air emissions  

SciTech Connect

The purpose of this document is to review technologies for treatment of air streams that contain chlorinated volatile organic compounds (CVOCS) and to describe a Department of Energy Office of Technology Development program that is planned to demonstrate innovative technologies for the abatement of CVOC emissions. This report describes the first phase of testing of off-gas treatment technologies. At least one more phase of testing is planned. Guidance for the preparation of this document was provided by a predecisional draft outline issued by the Department of Energy's Office of Technology Development. The report is intended to evaluate the technical and regulatory aspects, public acceptance, and estimated costs of technologies selected for development and testing. These technologies are compared to currently practiced or baseline methods for treatment of CVOC-laden airstreams. A brief overview is provided rather than detailed cost and data comparisons because many of these technologies have not yet been field tested. A description of other promising technologies for the treatment of CVOC emissions is also included. Trichloroethylene (TCE) and perchloroethylene (PCE) were used for industrial cleaning and solvent applications for several decades. These chemicals can be classified as CVOCS. As a result of past standard disposal practices, these types of compounds are persistent groundwater and soil contaminants throughout the United States and the Department of Energy Complex.

Rossabi, J.; Haselow, J.S.

1992-04-15

180

The emission patterns of volatile organic compounds during aerobic biotreatment of municipal solid waste using continuous and intermittent aeration.  

PubMed

Because volatile organic compounds (VOCs) are one of the main concerns during municipal solid waste (MSW) treatment, the release patterns and the environmental effects of VOCs were investigated during laboratory-scale aerobic biotreatments of MSW with continuous and intermittent negative ventilation. When the same airflow amounts were used, intermittent ventilation was found to reduce the total VOC emissions from continuous ventilation process by 28%. In this study, 23 types of volatile organic compounds were analyzed, of which butyraldehyde, ethanol, and butanone were emitted in the highest concentrations of 748, 372, and 260 mg/m3, respectively. During the aerobic biotreatment process, ketones, aldehydes, and alcohols were primarily released during the first 4 days, accounting for 86-98% of the total VOC emissions during this period. The emission concentrations of malodorous sulfide compounds displayed two peaks on day 4 and day 9, with the contribution to the total VOC emissions being enhanced from less than 10% to 76-83%. The release of terpenes and aromatics lasted for more than 10 days with no significant emission peaks and the proportions of those compounds in the total VOCs increased gradually, but no more than 50% even at the end of the process. Considering the strength of the odors, aldehydes were the predominant contributors at the beginning of the experiment, whereas malodorous sulfide compounds became the most odorous compound as the biological process continued. Most of the VOCs emitted at the concentrations beneath the level causing health threat to the workers. PMID:22616288

He, Pin-Jing; Tang, Jia-Fu; Yang, Na; Fang, Jing-Jing; He, Xiao; Shao, Li-Ming

2012-04-01

181

Vehicular emission of volatile organic compounds (VOCs) from a tunnel study in Hong Kong  

NASA Astrophysics Data System (ADS)

Vehicle emissions of volatile organic compounds (VOCs) were determined at the Shing Mun Tunnel, Hong Kong in summer and winter of 2003. One hundred and ten VOCs were quantified in this study. The average concentration of the total measured VOCs at the inlet and outlet of the tunnel were 81 250 pptv and 117 850 pptv, respectively. Among the 110 compounds, ethene, ethyne and toluene were the most abundant species in the tunnel. The total measured VOC emission factors ranged from 67 mg veh-1 km-1 to 148 mg veh-1 km-1, with an average of 115 mg veh-1 km-1. The five most abundant VOCs observed in the tunnel were, in decreasing order, ethene, toluene, n-butane, propane and i-pentane. These five most abundant species contributed over 38% of the total measured VOCs emitted. The high propane and n-butane emissions were found to be associated with liquefied petroleum gas (LPG)-fueled taxis. Fair correlations were observed between marker species (ethene, i-pentane, n-nonane, and benzene, toluene, ethylbenzene and xylenes - BTEX) with fractions of gasoline-fueled or diesel-fueled vehicles. Moreover, ethene, ethyne, and propene are the key species that were abundant in the tunnel but not in gasoline vapors or LPG. The ozone formation potential from the VOCs in Hong Kong was evaluated by the maximum increment reactivity (MIR). It was found to be 568 mg of ozone per vehicle per kilometer traveled. Among them, ethene, propene and toluene contribute most to the ozone-formation reactivity.

Ho, K. F.; Lee, S. C.; Ho, W. K.; Blake, D. R.; Cheng, Y.; Li, Y. S.; Ho, S. S. H.; Fung, K.; Louie, P. K. K.; Park, D.

2009-10-01

182

Emission of volatile organic sulfur compounds from a heavily polluted river in Guangzhou, South China.  

PubMed

Emissions of five volatile organic sulfur compounds (VOSCs), including methanethiol, carbonyl sulfide, dimethyl sulfide, carbon disulfide, and dimethyl disulfide, from a heavily polluted river, Shijing River in Guangzhou of South China, was studied. The results showed that the amounts of all VOSCs emitted from the river increased from downstream to upstream along the river with increasing magnitude of water pollution. The emission of carbonyl sulfide was the highest among the target analytes, ranging from 23.8 microg m(-2) h(-1) to 42.6 microg m(-2) h(-1) at the water surface of Shijin River. The concentration levels of VOSCs on the riverbank were lower than those at the water surface either in Shijing River or in Liuxi River. However, the contribution of dimethyl disulfide to the total VOSCs on the riverbank was higher than that at the water surface in most sampling sites, indicating that there might be a point source of dimethyl disulfide on the riverbank besides diffusion from water surface. The 24-h semi-continuous monitoring data revealed that the emissions of VOSCs at the water surface peaked at 9:00 and 21:00, which was consistent with the water quality variability in Shijin River caused by daily tidal variation. PMID:17849226

Sheng, Yanqing; Chen, Fanzhong; Yu, Ying; Wang, Xinming; Sheng, Guoying; Fu, Jiamo; Zeng, Eddy Y

2007-09-12

183

Toxic Volatile Organic Compounds in Environmental Tobacco Smoke:Emission Factors for Modeling Exposures of California Populations  

SciTech Connect

The primary objective of this study was to measure emission factors for selected toxic air in environmental tobacco smoke (ETS) using a room-sized environmental chamber. The emissions of 23 volatile organic compounds (VOCs), including 1,3-butadiene, three aldehydes and two vapor-phase N-nitrosarnines were determined for six commercial brands of cigarettes and reference cigarette 1R4F. The commercial brands were selected to represent 62.5% of the cigarettes smoked in California. For each brand, three cigarettes were machine smoked in the chamber. The experiments were conducted over four hours to investigate the effects of aging. Emission factors of the target compounds were also determined for sidestream smoke (SS). For almost all target compounds, the ETS emission factors were significantly higher than the corresponding SS values probably due to less favorable combustion conditions and wall losses in the SS apparatus. Where valid comparisons could be made, the ETS emission factors were generally in good agreement with the literature. Therefore, the ETS emission factors, rather than the SS values, are recommended for use in models to estimate population exposures from this source. The variabilities in the emission factors (pgkigarette) of the selected toxic air contaminants among brands, expressed as coefficients of variation, were 16 to 29%. Therefore, emissions among brands were generally similar. Differences among brands were related to the smoked lengths of the cigarettes and the masses of consumed tobacco. Mentholation and whether a cigarette was classified as light or regular did not significantly affect emissions. Aging was determined not to be a significant factor for the target compounds. There were, however, deposition losses of the less volatile compounds to chamber surfaces.

Daisey, J.M.; Mahanama, K.R.R.; Hodgson, A.T.

1994-10-01

184

[Source emission characteristics and impact factors of volatile halogenated organic compounds from wastewater treatment plant].  

PubMed

A low enrichment method of using Tenax as absorbent and liquid nitrogen as refrigerant has been established to sample the volatile halogenated organic compounds in Guangzhou Liede municipal wastewater treatment plant as well as its ambient air. The composition and concentration of target halogenated hydrocarbons were analyzed by combined thermal desorption/GC-MS to explore its sources profile and impact factors. The result showed that 19 halogenated organic compounds were detected, including 11 halogenated alkanets, 3 halogenated alkenes, 3 halogenated aromatic hydrocarbons and 2 haloesters, with their total concentrations ranged from 34.91 microg x m(-3) to 127.74 microg x m(-3) and mean concentrations ranged from n.d. to 33.39 microg x m(-3). Main pollutants of the studied plant were CH2Cl2, CHCl3, CFC-12, C2H4Cl2, CFC-11, C2HCl3 and C2Cl4, they came from the wastewater by volatilization. Among the six processing units, the dehydration room showed the highest level of halogenated organic compounds, followed by pumping station, while the sludge thickener was the lowest. The emissions from pumping station, aeration tank and biochemical pool were significantly affected by temperature and humidity of environment. PMID:22468521

He, Jie; Wang, Bo-Guang; Liu, Shu-Le; Zhao, De-Jun; Tang, Xiao-Dong; Zou, Yu

2011-12-01

185

Emissions of volatile organic compounds (VOCs) from the food and drink industries of the European community  

NASA Astrophysics Data System (ADS)

Estimates were made of the amounts of volatile organic compounds (VOCs) released into the atmosphere as a result of the industrial manufacture and processing of food and drink in the European Community. The estimates were based on a review of literature sources, industrial and government contacts and recent measurements. Data were found on seven food manufacturing sectors (baking, vegetable oil extraction, solid fat processing, animal rendering, fish meal processing, coffee production and sugar beet processing) and three drink manufacturing sectors (brewing, spirit production and wine making). The principle of a data quality label is advocated to illustrate the authors' confidence in the data, and to highlight areas for further research. Emissions of ethanol from bread baking and spirit maturation were found to be the principle sources. However, significant losses of hexane and large quantities of an ill-defined mixture of partially oxidized hydrocarbons were noted principally from seed oil extraction and the drying of plant material, respectively. This latter mixture included low molecular weight aldehydes, carboxylic acids, ketones, amines and esters. However, the precise composition of many emissions were found to be poorly understood. The total emission from the food and drink industry in the EC was calculated as 260 kt yr -1. However, many processes within the target industry were found to be completely uncharacterized and therefore not included in the overall estimate (e.g. soft drink manufacture, production of animal food, flavourings, vinegar, tea, crisps and other fried snacks). Moreover, the use of data quality labels illustrated the fact that many of our estimates were based on limited data. Hence, further emissions monitoring is recommended from identified sources (e.g. processing of sugar beet, solid fat and fish meal) and from uncharacterized sources.

Passant, Neil R.; Richardson, Stephen J.; Swannell, Richard P. J.; Gibson, N.; Woodfield, M. J.; van der Lugt, Jan Pieter; Wolsink, Johan H.; Hesselink, Paul G. M.

186

Field Derived Emission Factors For Formaldehyde and other Volatile Organic Compounds in FEMA Temporary Housing Units  

SciTech Connect

Sixteen previously occupied temporary housing units (THUs) were studied to assess emissions of volatile organic compounds. The whole trailer emission factors wereevaluated for 36 VOCs including formaldehyde. Indoor sampling was carried out in the THUs located in Purvis staging yard in Mississippi, USA. Indoor temperature andrelative humidity (RH) were also measured in all the trailers during sampling. Indoor temperatures were varied (increased or decreased) in a selection of THUs using theheating, ventilation and air conditioning (HVAC) systems. Indoor temperatures during sampling ranged from 14o C to 33o C, and relative humidity (RH) varied between 35percentand 74percent. Ventilation rates were increased in some trailers using bathroom fans and vents during some of the sampling events. Ventilation rates measured during some aselection of sampling events varied from 0.14 to 4.3 h-1. Steady state indoor formaldehyde concentrations ranged from 10 mu g-m-3 to 1000 mu g-m-3. The formaldehyde concentrations in the trailers were of toxicological significance. The effects of temperature, humidity and ventilation rates were also studied. A linearregression model was built using log of percentage relative humidity, inverse of temperature (in K-1), and inverse log ACH as continuous independent variables, trailermanufacturer as a categorical independent variable, and log of the chemical emission factors as the dependent variable. The coefficients of inverse temperature, log relativehumidity, log inverse ACH with log emission factor were found to be statistically significant for all the samples at the 95percent confidence level. The regression model wasfound to explain about 84percent of the variation in the dependent variable. Most VOC concentrations measured indoors in the Purvis THUs were mostly found to be belowvalues reported in earlier studies by Maddalena et al.,1,2 Hodgson et al.,3 and Hippelein4. Emissions of TMPB-DIB (a plasticizer found in vinyl products) were found to be higher than values reported in comparable housing by Hodgson et al.,3. Emissions of phenol were also found to be slightly higher than values reported in earlier studies1,2,3. This study can assist in retrospective formaldehyde exposure assessments of THUs where estimates of the occupants indoor formaldehyde exposures are needed.

Parthasarathy, Srinandini; Maddalena, Randy L.; Russell, Marion L.; Apte, Michael G.

2010-10-01

187

The emission of volatile compounds during the aerobic and the combined anaerobic/aerobic composting of biowaste  

NASA Astrophysics Data System (ADS)

Two different biowaste composting techniques were compared with regard to their overall emission of volatile compounds during the active composting period. In the aerobic composting process, the biowaste was aerated during a 12-week period, while the combined anaerobic/aerobic composting process consisted of a sequence of a 3-week anaerobic digestion (phase I) and a 2-week aeration period (phase II). While the emission of volatiles during phase I of the combined anaerobic/aerobic composting process was measured in a full-scale composting plant, the aerobic stages of both composting techniques were performed in pilot-scale composting bins. Similar groups of volatile compounds were analysed in the biogas and the aerobic composting waste gases, being alcohols, carbonyl compounds, terpenes, esters, sulphur compounds and ethers. Predominance of alcohols (38% wt/wt of the cumulative emission) was observed in the exhaust air of the aerobic composting process, while predominance of terpenes (87%) and ammonia (93%) was observed in phases I and II of the combined anaerobic/aerobic composting process, respectively. In the aerobic composting process, 2-propanol, ethanol, acetone, limonene and ethyl acetate made up about 82% of the total volatile organic compounds (VOC)-emission. Next to this, the gas analysis during the aerobic composting process revealed a strong difference in emission profile as a function of time between different groups of volatiles. The total emission of VOC, NH 3 and H 2S during the aerobic composting process was 742 g ton -1 biowaste, while the total emission during phases I and II of the combined anaerobic/aerobic composting process was 236 and 44 g ton -1 biowaste, respectively. Taking into consideration the 99% removal efficiency of volatiles upon combustion of the biogas of phase I in the electricity generator, the combined anaerobic/aerobic composting process can be considered as an attractive alternative for aerobic biowaste composting because of its 17 times lower overall emission of the volatiles mentioned.

Smet, Erik; Van Langenhove, Herman; De Bo, Inge

188

Volatile organic compound concentrations and emission rates measured over one year in a new manufactured house  

SciTech Connect

A study to measure indoor concentrations and emission rates of volatile organic compounds (VOCs), including formaldehyde, was conducted in a new, unoccupied manufactured house installed at the National Institute of Standards and Technology (NIST) campus. The house was instrumented to continuously monitor indoor temperature and relative humidity, heating and air conditioning system operation, and outdoor weather. It also was equipped with an automated tracer gas injection and detection system to estimate air change rates every 2 h. Another automated system measured indoor concentrations of total VOCs with a flame ionization detector every 30 min. Active samples for the analysis of VOCs and aldehydes were collected indoors and outdoors on 12 occasions from August 2002 through September 2003. Individual VOCs were quantified by thermal desorption to a gas chromatograph with a mass spectrometer detector (GC/MS). Formaldehyde and acetaldehyde were quantified by high performance liquid chromatography (HPLC). Weather conditions changed substantially across the twelve active sampling periods. Outdoor temperatures ranged from 7 C to 36 C. House air change rates ranged from 0.26 h{sup -1} to 0.60 h{sup -1}. Indoor temperature was relatively constant at 20 C to 24 C for all but one sampling event. Indoor relative humidity (RH) ranged from 21% to 70%. The predominant and persistent indoor VOCs included aldehydes (e.g., formaldehyde, acetaldehyde, pentanal, hexanal and nonanal) and terpene hydrocarbons (e.g., a-pinene, 3-carene and d-limonene), which are characteristic of wood product emissions. Other compounds of interest included phenol, naphthalene, and other aromatic hydrocarbons. VOC concentrations were generally typical of results reported for other new houses. Measurements of total VOCs were used to evaluate short-term changes in indoor VOC concentrations. Most of the VOCs probably derived from indoor sources. However, the wall cavity was an apparent source of acetaldehyde, toluene and xylenes and the belly space was a source of 2-butanone, lower volatility aldehydes and aromatic hydrocarbons. Indoor minus outdoor VOC concentrations varied with time. Adjusted formaldehyde concentrations exhibited the most temporal variability with concentrations ranging from 25 {micro}g m{sup -3} to 128 {micro}g m{sup -3} and the lowest concentrations occurring in winter months when indoor RH was low. A model describing the emissions of formaldehyde from urea-formaldehyde wood products as a function of temperature, RH and concentration reasonably predicted the temporal variation of formaldehyde emissions in the house. Whole-house emissions of other VOCs generally declined over the first three months and then remained relatively constant over a several month period. However, their emissions were generally lowest during the winter months. Also, an apparent association between TVOC emissions and outdoor temperature was observed on a one-week time scale.

Hodgson, Alfred T.; Nabinger, Steven J.; Persily, Andrew K.

2004-09-01

189

Measurement of surface emission flux rates for volatile organic compounds at Technical Area 54  

SciTech Connect

The survey described in this report was conducted to estimate the mass of volatile organic compounds venting to the atmosphere from active and inactive waste disposal sites at Technical Area 54. A large number of nonintrusive passive sample collection devices were placed on the ground surface for 72 hours to characterize an area of approximately 150 acres. Results provided an indication of the boundary location of the known volatile organic plume, plume constituents, and isolated high concentration areas. The data from this survey enhanced existing data from a limited number of monitor wells currently used for plume surveillance. Results indicate that the estimated mass emission to the atmosphere is orders of magnitude lower than what is considered a small flux rate at a spill site or a Resource Conservation and Recovery Act landfill and is far below the threshold limit established by the State of New Mexico as an air quality concern.

Trujillo, V.; Morgenstern, M.; Krier, D. [Los Alamos National Lab., NM (United States); Gilkeson, R. [Weirich and Associates, Albuquerque, NM (United States)

1998-06-01

190

Effects of low concentration biodiesel blends application on modern passenger cars. Part 2: impact on carbonyl compound emissions.  

PubMed

Today in most European member states diesel contains up to 5% vol biodiesel. Since blending is expected to increase to 10% vol, the question arises, how this higher mixing ratio will affect tailpipe emissions particularly those linked to adverse health effects. This paper focuses on the impact of biodiesel on carbonyl compound emissions, attempting also to identify possible relationship between biodiesel feedstock and emissions. The blends were produced from five different feedstocks, commonly used in Europe. Measurements were conducted on a Euro 3 common-rail passenger car over various driving cycles. Results indicate that generally the use of biodiesel at low concentrations has a minor effect on carbonyl compound emissions. However, certain biodiesels resulted in significant increases while others led to decreases. Biodiesels associated with increases were those derived from rapeseed oil (approx. 200%) and palm oil (approx. 180%), with the highest average increases observed at formaldehyde and acroleine/acetone. PMID:20034715

Fontaras, Georgios; Karavalakis, Georgios; Kousoulidou, Marina; Ntziachristos, Leonidas; Bakeas, Evangelos; Stournas, Stamoulis; Samaras, Zissis

2010-01-19

191

Biogenic volatile organic compound emissions from a lowland tropical wet forest in Costa Rica  

NASA Astrophysics Data System (ADS)

Twenty common plant species were screened for emissions of biogenic volatile organic compounds (BVOCs) at a lowland tropical wet forest site in Costa Rica. Ten of the species examined emitted substantial quantities of isoprene. These species accounted for 35-50% of the total basal area of old-growth forest on the major edaphic site types, indicating that a high proportion of the canopy leaf area is a source of isoprene. A limited number of canopy-level BVOC flux measurements were also collected by relaxed eddy accumulation (REA). These measurements verify that the forest canopy in this region is indeed a significant source of isoprene. In addition, REA fluxes of methanol and especially acetone were also significant, exceeding model estimates and warranting future investigation at this site. Leaf monoterpene emissions were non-detectable or very low from the species surveyed, and ambient concentrations and REA fluxes likewise were very low. Although the isoprene emission rates reported here are largely consistent with phylogenetic relations found in other studies (at the family, genus, and species levels), two species in the family Mimosaceae, a group previously found to consist largely of non-isoprene emitters, emitted significant quantities of isoprene. One of these, Pentaclethra macroloba (Willd.) Kuntze, is by far the most abundant canopy tree species in the forests of this area, composing 30-40% of the total basal area. The other, Zygia longifolia ( Humb. & Bonpl.) Britton & Rose is a common riparian species. Our results suggest that the source strength of BVOCs is important not only to tropical atmospheric chemistry, but also may be important in determining net ecosystem carbon exchange.

Geron, Chris; Guenther, Alex; Greenberg, Jim; Loescher, Henry W.; Clark, Deborah; Baker, Brad

192

Positron emission tomography imaging and clinical progression in relation to molecular pathology in the first Pittsburgh Compound B positron emission tomography patient with Alzheimer's disease  

PubMed Central

The accumulation of ?-amyloid in the brain is an early event in Alzheimer’s disease. This study presents the first patient with Alzheimer’s disease who underwent positron emission tomography imaging with the amyloid tracer, Pittsburgh Compound B to visualize fibrillar ?-amyloid in the brain. Here we relate the clinical progression, amyloid and functional brain positron emission tomography imaging with molecular neuropathological alterations at autopsy to gain new insight into the relationship between ?-amyloid accumulation, inflammatory processes and the cholinergic neurotransmitter system in Alzheimer’s disease brain. The patient underwent positron emission tomography studies with 18F-fluorodeoxyglucose three times (at ages 53, 56 and 58 years) and twice with Pittsburgh Compound B (at ages 56 and 58 years), prior to death at 61 years of age. The patient showed a pronounced decline in cerebral glucose metabolism and cognition during disease progression, while Pittsburgh Compound B retention remained high and stable at follow-up. Neuropathological examination of the brain at autopsy confirmed the clinical diagnosis of pure Alzheimer’s disease. A comprehensive neuropathological investigation was performed in nine brain regions to measure the regional distribution of ?-amyloid, neurofibrillary tangles and the levels of binding of 3H-nicotine and 125I-?-bungarotoxin to neuronal nicotinic acetylcholine receptor subtypes, 3H-L-deprenyl to activated astrocytes and 3H-PK11195 to microglia, as well as butyrylcholinesterase activity. Regional in vivo 11C-Pittsburgh Compound B-positron emission tomography retention positively correlated with 3H-Pittsburgh Compound B binding, total insoluble ?-amyloid, and ?-amyloid plaque distribution, but not with the number of neurofibrillary tangles measured at autopsy. There was a negative correlation between regional fibrillar ?-amyloid and levels of 3H-nicotine binding. In addition, a positive correlation was found between regional 11C-Pittsburgh Compound B positron emission tomography retention and 3H-Pittsburgh Compound B binding with the number of glial fibrillary acidic protein immunoreactive cells, but not with 3H-L-deprenyl and 3H-PK-11195 binding. In summary, high 11C-Pittsburgh Compound B positron emission tomography retention significantly correlates with both fibrillar ?-amyloid and losses of neuronal nicotinic acetylcholine receptor subtypes at autopsy, suggesting a closer involvement of ?-amyloid pathology with neuronal nicotinic acetylcholine receptor subtypes than with inflammatory processes.

Kadir, Ahmadul; Marutle, Amelia; Gonzalez, Daniel; Scholl, Michael; Almkvist, Ove; Mousavi, Malahat; Mustafiz, Tamanna; Darreh-Shori, Taher; Nennesmo, Inger

2011-01-01

193

Air-surface exchange of nonmethane organic compounds at a grassland site: Seasonal variations and stressed emissions  

Microsoft Academic Search

Emissions of nonmethane organic compounds (NMOCs) were measured by a static enclosure technique at a grassland site in the midwestern United States during the growing seasons over a 2-year period. A mixture of nonmethane hydrocarbons (NMHCs) and oxygenated hydrocarbons (OxHCs) was emitted from the surface at rates exhibiting large seasonal and year-to-year variations. The average emission rate (and standard error)

Yoshiko Fukui; Paul V. Doskey

1998-01-01

194

Measurement of emissions from air pollution sources. 2: C⁠through Cââ organic compounds from medium duty diesel trucks  

Microsoft Academic Search

Gas- and particle-phase tailpipe emissions from late-model medium duty diesel trucks are quantified using a two-stage dilution source sampling system. The diesel trucks are driven through the hot-start Federal Test Procedure (FTP) urban driving cycle on a transient chassis dynamometer. Emission rates of 52 gas-phase volatile hydrocarbons, 67 semivolatile and 28 particle-phase organic compounds, and 26 carbonyls are quantified along

J. J. Schauer; M. J. Kleeman; G. R. Cass; B. R. T. Simoneit

1999-01-01

195

Blue amplified spontaneous emission from a stilbenoid-compound-doped polymer optical fiber.  

PubMed

We report on the fabrication and characteristics of a step-index glass-clad polymer optical fiber that uses a novel fluorescent stilbenoid compound for lasing and amplification applications. The compound, 1, 4-bis(4-diphenyl-amino-styryl)-benzene, is specifically designed for the blue region of the spectrum and has a very high quantum yield of 0.85 in a solid-state polymer host and a large Stokes shift. Significant spectral narrowing and superlinear increase of output intensity are observed under photoexcitation at 355 nm, which are indicative of the occurrence of amplified spontaneous emission. By means of gain spectroscopy, a large optical gain of up to 36 cm(-1) at 494 nm has been obtained for the fiber when it is transversely photoexcited at 12 mJ/cm(2) . The waveguide loss has been measured to be 0.7 cm(-1) at 494 nm. The demonstration of high gain and low waveguide loss has favorable implications for the construction of a very compact, tunable coherent light source. PMID:18059742

Kobayashi, T; Blau, W J; Tillmann, H; Hörhold, H H

2001-12-15

196

Observations of nonmethane organic compounds during ARCTAS - Part 1: Biomass burning emissions and plume enhancements  

NASA Astrophysics Data System (ADS)

Mixing ratios of a large number of nonmethane organic compounds (NMOCs) were observed by the Trace Organic Gas Analyzer (TOGA) on board the NASA DC-8 as part of the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) field campaign. Many of these NMOCs were observed concurrently by one or both of two other NMOC measurement techniques on board the DC-8: proton-transfer-reaction mass spectrometry (PTR-MS) and whole air canister sampling (WAS). A comparison of these measurements to the data from TOGA indicates good agreement for the majority of co-measured NMOCs. The ARCTAS study, which included both spring and summer deployments, provided opportunities to sample a large number of biomass burning (BB) plumes with origins in Asia, California and central Canada, ranging from very recent emissions to plumes aged one week or more. For this analysis, BB smoke interceptions were grouped by flight, source region and, in some cases, time of day, generating 40 identified BB plumes for analysis. Normalized excess mixing ratios (NEMRs) to CO were determined for each of the 40 plumes for up to 19 different NMOCs or NMOC groups. Although the majority of observed NEMRs for individual NMOCs or NMOC groups were in agreement with previously-reported values, the observed NEMRs to CO for ethanol, a rarely quantified gas-phase trace gas, ranged from values similar to those previously reported, to up to an order of magnitude greater. Notably, though variable between plumes, observed NEMRs of individual light alkanes are highly correlated within BB emissions, independent of estimated plume ages. BB emissions of oxygenated NMOC were also found to be often well-correlated. Using the NCAR Master Mechanism chemical box model initialized with concentrations based on two observed scenarios, fresh Canadian BB and fresh Californian BB, decreases are predicted for the low molecular weight carbonyls (i.e. formaldehyde, acetaldehyde, acetone and methyl ethyl ketone, MEK) and alcohols (i.e. methanol and ethanol) as the plumes evolve in time, i.e. the production of these compounds is less than the chemical loss. Comparisons of the modeled NEMRs to the observed NEMRs from BB plumes estimated to be three days in age or less indicate overall good agreement.

Hornbrook, R. S.; Blake, D. R.; Diskin, G. S.; Fried, A.; Fuelberg, H. E.; Meinardi, S.; Mikoviny, T.; Richter, D.; Sachse, G. W.; Vay, S. A.; Walega, J.; Weibring, P.; Weinheimer, A. J.; Wiedinmyer, C.; Wisthaler, A.; Hills, A.; Riemer, D. D.; Apel, E. C.

2011-11-01

197

X-ray K ? 1 emission spectra of sulfur in dialkyl sulfides and some heterocyclic compounds of sulfur  

Microsoft Academic Search

The x-ray K~ffemission spectra were obtained for the sulfur in dialkyl sulfides RzS (where R = CH~, C2Hs, C4H9, C6H13, CsHIT), diphenyl sulfide, and some heterocyclic compounds. By comparison with calculations the emission peaks were assigned to electronic transitions from levels of corresponding symmetry. In the unsaturated compounds interaction was detected between the unshared electron pair of the sulfur atom

L. N. Mazalov; A. P. Sadovskii; É. A. Gal'tsova; V. V. Murakhtanov; V. G. Torgov; V. M. Bertenev; A. P. Zeif

1973-01-01

198

Emissions of isoprenoids and oxygenated biogenic volatile organic compounds from a New England mixed forest  

NASA Astrophysics Data System (ADS)

Fluxes of biogenic volatile organic compounds, including isoprene, monoterpenes, and oxygenated VOCs measured above a mixed forest canopy in western Massachusetts during the 2005 and 2007 growing seasons are reported. Measurements were made using proton transfer reaction mass spectrometry (PTR-MS) and converted to fluxes using the disjunct eddy covariance technique. Isoprene was by far the predominant BVOC emitted at this site, with summer mid-day average fluxes of 5.3 and 4.4 mg m-2 h-1 in 2005 and 2007, respectively. In comparison, mid-day average fluxes of monoterpenes were 0.21 and 0.15 mg m-2 h-1 in each of these years. On short times scales (days), the diel pattern in emission rate compared well with a standard emission algorithm for isoprene. The general shape of the seasonal cycle and the observed decrease in isoprene emission rate in early September was, however, not well captured by the model. Monoterpene emission rates exhibited dependence on light as well as temperature, as determined from the improved fit to the observations obtained by including a light-dependent term in the model. The mid-day average flux of methanol from the canopy was 0.14 mg m-2 h-1 in 2005 and 0.19 mg m-2 h-1 in 2007, but the maximum flux was observed in spring (29 May 2007), when the flux reached 1.0 mg m-2 h-1. This observation is consistent with enhanced methanol production during leaf expansion. Summer mid-day fluxes of acetone were 0.15 mg m-2 h-1 during a short period in 2005, but only 0.03 mg m-2 h-1 averaged over 2007. Episodes of negative fluxes of oxygenated VOCs, particularly acetone, were observed periodically, especially in 2007. Thus, deposition within the canopy could help explain the low season-averaged flux of acetone in 2007. Fluxes of species of biogenic origin at mass-to-charge (m/z) ratios of 73 (0.05 mg m-2 h-1 in 2005; 0.03 mg m-2 h-1 in 2007) and 153 (5 ?g m-2 h-1 in 2007), possibly corresponding to methyl ethyl ketone and an oxygenated terpene, respectively, were also observed.

McKinney, K. A.; Lee, B. H.; Vasta, A.; Pho, T. V.; Munger, J. W.

2010-11-01

199

Emissions of isoprenoids and oxygenated biogenic volatile organic compounds from a New England mixed forest  

NASA Astrophysics Data System (ADS)

Fluxes of biogenic volatile organic compounds, including isoprene, monoterpenes, and oxygenated VOCs measured above a mixed forest canopy in central Massachusetts during the 2005 and 2007 growing seasons are reported. Mixing ratios were measured using proton transfer reaction mass spectrometry (PTR-MS) and fluxes computed by the disjunct eddy covariance technique. Isoprene was by far the predominant BVOC emitted at this site, with summer mid-day average fluxes of 5.3 and 4.4 mg m-2 hr-1 in 2005 and 2007, respectively. In comparison, mid-day average fluxes of monoterpenes were 0.21 and 0.15 mg m-2 hr-1 in each of these years. On short times scales (days), the diel pattern in emission rate compared well with a standard emission algorithm for isoprene. The general shape of the seasonal cycle and the observed decrease in isoprene emission rate in early September was, however, not well captured by the model. Monoterpene emission rates exhibited dependence on light as well as temperature, as determined from the improved fit to the observations obtained by including a light-dependent term in the model. The mid-day average flux of methanol from the canopy was 0.14 mg m-2 hr-1 in 2005 and 0.19 mg m-2 hr-1 in 2007, but the maximum flux was observed in spring (29 May 2007), when the flux reached 1.0 mg m-2 hr-1. This observation is consistent with enhanced methanol production during leaf expansion. Summer mid-day fluxes of acetone were 0.15 mg m-2 hr-1 during a short period in 2005, but only 0.03 mg m-2 h-1 averaged over 2007. Episodes of negative fluxes of oxygenated VOCs, particularly acetone, were observed periodically, especially in 2007. Thus, deposition within the canopy could help explain the low season-averaged flux of acetone in 2007. Fluxes of species of biogenic origin at mass-to-charge (m/z) ratios of 73 (0.05 mg m-2 hr-1 in 2005; 0.03 mg m-2 hr-1 in 2007) and 153 (5 ?g m-2 hr-1 in 2007), possibly corresponding to methyl ethyl ketone and an oxygenated terpene or methyl salicylate, respectively, were also observed.

McKinney, K. A.; Lee, B. H.; Vasta, A.; Pho, T. V.; Munger, J. W.

2011-05-01

200

Emissions of volatile organic compounds from Quercus ilex L. measured by Proton Transfer Reaction Mass Spectrometry under different environmental conditions  

NASA Astrophysics Data System (ADS)

Volatile organic compound (VOC) emissions of the Mediterranean holm oak (Quercus ilex L.) were investigated using a fast Proton Transfer Reaction Mass Spectrometry (PTR-MS) instrument for analysis. This technique is able to measure compounds with a proton affinity higher than water with a high time resolution of 1 s per compound. Hence nearly all VOCs can be detected on-line. We could clearly identify the emission of methanol, acetaldehyde, ethanol, acetone, acetic acid, isoprene, monoterpenes, toluene, and C10-benzenes. Some other species could be tentatively denominated. Among these are the masses 67 (cyclo pentadiene), mass 71 (tentatively attributed to methyl vinyl ketone (MVK) and metacrolein (MACR)), 73 (attributed to methyl ethyl ketone (MEK)), 85 (C6H12 or hexanol), and 95 (vinylfuran or phenol). The emissions of all these compounds (identified as well as nonidentified) together represent 99% of all masses detected and account for a carbon loss of 0.7-2.9% of the net photosynthesis. Of special interest was a change in the emission behavior under changing environmental conditions such as flooding or fast light/dark changes. Flooding of the root system caused an increase of several VOCs between 60 and 2000%, dominated by the emission of ethanol and acetaldehyde, which can be explained by the well described production of ethanol under anoxic conditions of the root system and the recently described subsequent transport and partial oxidation to acetaldehyde within the green leaves. However, ethanol emissions were dominant. Additionally, bursts of acetaldehyde with lower ethanol emission were also found under fast light/dark changes. These bursts are not understood.

Holzinger, R.; Sandoval-Soto, L.; Rottenberger, S.; Crutzen, P. J.; Kesselmeier, J.

2000-08-01

201

Plant growth-promoting rhizobacteria modulate root-system architecture in Arabidopsis thaliana through volatile organic compound emission  

Microsoft Academic Search

Extensive communication occurs between plants and microorganisms during different stages of plant development in which signaling molecules from the two partners play an important role. Volatile organic compounds (VOCs) emission by certain plant-growth promoting rhizo- bacteria (PGPR) has been found to be involved in plant growth. However, little is known about the role of bacterial VOCs in plant developmental processes.

Francisca M. Gutiérrez-Luna; José López-Bucio; Josué Altamirano-Hernández; Eduardo Valencia-Cantero; Homero Reyes de la Cruz; Lourdes Macías-Rodríguez

2010-01-01

202

CAPILLARY GAS CHROMATOGRAPHY-ATOMIC EMISSION DETECTION METHOD FOR THE DETERMINATION OF PENTYLATED ORGANOTIN COMPOUNDS: INTERLABORATORY STUDY  

EPA Science Inventory

A capillary gas chromatography-atomic emission detection (GC-AED) method was developed for the U. S. Environmental Protection Agency's Environmental Monitoring Systems Laboratory in Las Vegas, NV, for determination of selected organotin compounds. Here we report on an interlabora...

203

The effects of lamellar structure in the TiAl intermetallic compound on its acoustic emission behavior during tensile deformation  

Microsoft Academic Search

The dynamic behavior of TiAl intermetallic compounds during tensile deformation has been determined by the different appearance of the (?2 + ?) lamellar structure using the acoustic emission (AE) method. The AE events of these materials are obviously different. There is, however, no effectively direct evidence to prove the relationship between the microstructure of these TiAl alloys and the AE

A. Zhu; K. Yoshida; H. Tagaki; K. Sakamaki

1996-01-01

204

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

National Technical Information Service (NTIS)

This report presents estimates of monthly sulfur dioxide (SO(sub 2)), nitrogen oxides (NO(sub x)), and nonmethane voltatile organic compound (VOC) emissions by sector, region, and state in the contiguous United States for the years 1975 through 1988. This...

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

1990-01-01

205

Nitrogen compound emissions from fertilized soils in a maize field pine tree forest agrosystem in the southwest of France  

Microsoft Academic Search

The use of nitrogen fertilizers in agriculture is a significant source of reactive nitrogen compounds for the atmosphere. Emissions of NO, NH3, and N2O were measured on irrigated maize fields, on acidic podzols, set up in a large pine tree forest system in the southwestern part of France. Measurements were carried out over a yearly period: before, during, and after

Corinne Jambert; Robert A. Delmas; Louis Labroue; Pierre Chassin

1994-01-01

206

A new European plant-specific emission inventory of biogenic volatile organic compounds for use in atmospheric transport models  

NASA Astrophysics Data System (ADS)

We present a new European plant-specific emission inventory for isoprene, monoterpenes, sesquiterpenes and other VOC (OVOC), with a spatial resolution of 10 km, for implementation in atmospheric transport models. The inventory incorporates new data on emission factors at standard conditions for tree and crop species that became available in the last years and more accurate data on foliar biomass densities coming from several new litterfall databases. In contrast to previous emission inventories, a bioclimatic correction factor was introduced to correct the foliar biomass densities for the different plant growth conditions that can be found in Pan-Europe. The 2004-2005 averaged annual total biogenic volatile organic compound (BVOC) emissions for the Pan-European domain are estimated to be about 15 Tg with a large contribution from the OVOC class of about 6 Tg and from monoterpenes of about 5 Tg. Annual isoprene emissions are found to be about 3 Tg, insensitive to the chosen emission algorithm. For the first time crop-specific land use information and standard emission factors were employed. Contrary to former European inventories, emissions of monoterpenes and OVOC were found to originate to a large extent from agriculture. However, monoterpene standard emission factors for crops are highly uncertain and probably positively biased by measurement artifacts. Further experiments on crop emissions should be carried out to check the validity of the high emission factors for monoterpenes and OVOC. In view of future intensified use of agricultural crops as biofuels, emissions of OVOC and monoterpenes from agriculture need to be evaluated in the field.

Karl, M.; Guenther, A.; Köble, R.; Seufert, G.

2008-12-01

207

Evaluating the performance of pyrogenic and biogenic emission inventories against one decade of space-based formaldehyde columns  

NASA Astrophysics Data System (ADS)

A new one-decade (1997-2006) dataset of formaldehyde (HCHO) columns retrieved from GOME and SCIAMACHY is compared with HCHO columns simulated by an updated version of the IMAGES global chemical transport model. This model version includes an optimized chemical scheme with respect to HCHO production, where the short-term and final HCHO yields from pyrogenically emitted non-methane volatile organic compounds (NMVOCs) are estimated from the Master Chemical Mechanism (MCM) and an explicit speciation profile of pyrogenic emissions. The model is driven by the Global Fire Emissions Database (GFED) version 1 or 2 for biomass burning, whereas biogenic emissions are provided either by the Global Emissions Inventory Activity (GEIA), or by a newly developed inventory based on the Model of Emissions of Gases and Aerosols from Nature (MEGAN) algorithms driven by meteorological fields from the European Centre for Medium-Range Weather Forecasts (ECMWF). The comparisons focus on tropical ecosystems, North America and China, which experience strong biogenic and biomass burning NMVOC emissions reflected in the enhanced measured HCHO columns. These comparisons aim at testing the ability of the model to reproduce the observed features of the HCHO distribution on the global scale and at providing a first assessment of the performance of the current emission inventories. The high correlation coefficients (r>0.7) between the observed and simulated columns over most regions indicate a good consistency between the model, the implemented inventories and the HCHO dataset. The use of the MEGAN-ECMWF inventory improves the model/data agreement in almost all regions, but biases persist over parts of Africa and Australia. Although neither GFED version is consistent with the data over all regions, a better agreement is achieved over Indonesia and Southern Africa when GFEDv2 is used, but GFEDv1 succeeds better in getting the correct seasonal patterns and intensities of the fire episodes over the Amazon basin, as reflected in the significantly higher correlations calculated in this region. Although the uncertainties in the HCHO retrievals, especially over fire scenes, can be quite large, this study provides a first assessment about whether the improved methodologies and input data implemented in GFEDv2 and MEGAN-ECMWF lead to better results in the comparisons of modelled with observed HCHO column measurements.

Stavrakou, T.; Müller, J.-F.; de Smedt, I.; van Roozendael, M.; van der Werf, G. R.; Giglio, L.; Guenther, A.

2009-02-01

208

Influence of suspended particles on indoor semi-volatile organic compounds emission  

NASA Astrophysics Data System (ADS)

Semi-volatile organic compounds (SVOCs) have been attracting more and more attentions to many researchers in these years. Because SVOCs have a strong tendency for adsorption to suspended particles, we take the effect of suspended particles into account to study the transport mechanism of SVOCs in the air. We establish a mathematical model to describe the transport mechanism of SVOCs, and study the transport processes of both gas- and particle-phase di-2-ethylhexyl phthalate (DEHP) in Field and Laboratory Emission Cells (FLECs). The predictions by the proposed model not only fit well with the experimental data of previous studies, but also show that the gas-phase DEHP concentration increases rapidly in the first few seconds and increases slowly during the following 200 days due to different transport mechanisms in the two periods. Meanwhile, when the particle radiuses are of the order of micron and the air changes per hour (ACH) is large enough, the characteristic time for DEHP getting gas/particle equilibrium is much longer than the residence time of a particle in the flow field, and thus there is no significant influence of suspended particles on the total concentration of DEHP in the air. Oppositely, the influence of particles on DEHP emission will be enhanced for a cycling air flow system with a small ACH, where increasing ACH will reduce the concentrations of particle-phase SVOCs. Besides, if the particle radiuses are of the order of nanometer, decreasing the particle radiuses will shorter the characteristic time for DEHP getting gas/particle equilibrium, and finally increase the particle-phase concentration of DEHP.

Hu, Kang; Chen, Qun; Hao, Jun-Hong

2013-11-01

209

Continental background in oceanic air masses and marine emission of Volatile Organic Compounds in Drake Passage  

NASA Astrophysics Data System (ADS)

In Drake Passage, continental air masses are mixed with pure oceanic air masses, and are evolving through the circumpolar atmospheric circulation. The most probable origin of continental air is Australia and Patagonia. Atmospheric dust content and deposition rate is quite unknown in Austral region. Long term evolution of continental air over the ocean is only poorly known, even if the oceanic surface is more than 80% of the Southern Hemisphere. Recent field experiments have shown large differences between estimated and measured dust or deposition. Dust particles can be carried up from the sources into the atmosphere for long range transport. Then, dust is deposited into the ocean surface. Dust deposition can bring micro-nutrients to the marine biota as trace metals and metalloids. During transport, some trace gases are oxidized depending on their lifetimes. It is therefore possible to calculate the photochemical age of the air masses, with some tracers of the long range transport and some tracers of sources origin. The Southern Ocean is poorly characterized in term of organic compounds and trace gases. Numerous experiments have shown that marine biology, such as phytoplankton can emit volatile organic compounds (VOC) but few shipborne measurements have been performed to determine potential source or sink of selected species. Especially in austral region, recent campaigns (MANCHOT in Indian Austral Ocean in December 2004 (Colomb et al, 2009); OOMPH between Cape Town and Punta Arenas in January 2007) have shown the impact of oceanic emission on the local and global atmospheric chemistry. During the ANT XXV-4 cruise on board the Polarstern in 2009, from Punta Arenas through Drake passage to Antarctic Peninsula, 165 air samples and 25 aerosol samples were collected, distributed all along the track. Additionally we took 4 rain samples to estimate the wet deposition. All the samples were taken at the front of the crow deck. Particles size and distribution and ozone concentration were also measured continuously. Preliminary results of the campaign will be presented including: - Relation between dust, trace gases and the photochemical age of the air mass, - Dust deposition and the water soluble fraction of aerosol over the remote Austral ocean region, - Atmospheric composition and trace gases emission from marine sources, or from continental sources after a long-range transport

Colomb, Aurélie; Paris, Rodolphe; Losno, Rémi; Desboeufs, Karine; Provost, Christine

2010-05-01

210

Carbon-11-Pittsburgh compound B positron emission tomography imaging of amyloid deposition in presenilin 1 mutation carriers.  

PubMed

(11)Carbon-Pittsburgh compound B positron emission tomography studies have suggested early and prominent amyloid deposition in the striatum in presenilin 1 mutation carriers. This cross-sectional study examines the (11)Carbon-Pittsburgh compound B positron emission tomography imaging profiles of presymptomatic and mildly affected (mini-mental state examination ? 20) carriers of seven presenilin 1 mutations, comparing them with groups of controls and symptomatic sporadic Alzheimer's disease cases. Parametric ratio images representing (11)Carbon-Pittsburgh compound B retention from 60 to 90 min were created using the pons as a reference region and nine regions of interest were studied. We confirmed that increased amyloid load may be detected in presymptomatic presenilin 1 mutation carriers with (11)Carbon-Pittsburgh compound B positron emission tomography and that the pattern of retention is heterogeneous. Comparison of presenilin 1 and sporadic Alzheimer's disease groups revealed significantly greater thalamic retention in the presenilin 1 group and significantly greater frontotemporal retention in the sporadic Alzheimer's disease group. A few individuals with presenilin 1 mutations showed increased cerebellar (11)Carbon-Pittsburgh compound B retention suggesting that this region may not be as suitable a reference region in familial Alzheimer's disease. PMID:21084313

Knight, William D; Okello, Aren A; Ryan, Natalie S; Turkheimer, Federico E; Rodríguez Martinez de Llano, Sofia; Edison, Paul; Douglas, Jane; Fox, Nick C; Brooks, David J; Rossor, Martin N

2010-11-16

211

Biological Volatile Organic Compounds (BVOCs) emissions from the planktonic diatom Thalassiosira pseudonana  

NASA Astrophysics Data System (ADS)

Understanding the behavior of biological volatile organic compounds (BVOCs) is important because in the atmosphere they can be highly reactive, have short residence times, and serve as precursors to aerosol particles. . At present the origin and quantities of BVOCs are still unknown. Phytoplankton and oceanic microbes have been considered an insignificant source of BVOCs until the last few years. In this study we investigated the importance of the diatom Thalassiosira pseudonana in the release of BVOCs into the atmosphere The focus of this study was to determine: a.) BVOC production that would occur over thirty days in which the species would experience initial growth, followed by cell lysis; and b.) to address the effect of nutrient limitation on VOC emissions. Our hypothesis was that the greatest formation of BVOCs would occur during cell lysis due to the breaking of cell membranes and release of organic matter into the surface water which could then undergo photolysis. Media was grown in filtered coastal water and inoculated with T. pseudonana. Samples were taken with a trap and purge system attached to a gas chromatograph with flame ionization detector (Hewlett Packard GC-FID 6890). Two main compounds were observed: isoprene and dimethyl sulfide (DMS). These two compounds have been linked to form aerosols in the atmosphere. After cell lysis had occurred, the production of isoprene remained constant throughout the entire life cycle at approximately 1.55x 10-19 moles/cell/hr. For DMS an increase in production occurred after cell lysis with a maximum production of 2.24 x 10-17 moles/cell/hr on the 25th day of the growth cycle. Key nutrients such as phosphate, nitrate and silica were limited during a series of incubations. BVOC production decreased as nutrient limitation occurred. A secondary VOC, 2, 3-dimethyl pentane (2, 3-DMP), was observed as a by-product of the environmental media. 2, 3-DMP may be produced during the breakdown of vitamin B12 within the F/2nutrient media. Review of satellite measured chlorophyll-a ratio to BVOCs utilized in global calculations of BVOCs production suggest that the models may underestimate BVOC production because cell lysis is ignored.

Evans, T.; Mak, J. E.

2009-12-01

212

A new European plant-specific emission inventory of biogenic volatile organic compounds for use in atmospheric transport models  

NASA Astrophysics Data System (ADS)

We present a new European plant-specific emission inventory for isoprene, monoterpenes, sesquiterpenes and oxygenated VOC (OVOC), on a spatial resolution of 0.089×0.089 degrees, for implementation in atmospheric transport models. The inventory incorporates more accurate data on foliar biomass densities from several litterfall databases that became available in the last years for the main tree species in Europe. A bioclimatic correction factor was introduced to correct the foliar biomass densities of trees and crops for the different plant growth conditions that can be found in Pan-Europe. Long-term seasonal variability of agriculture and forest emissions was taken into account by implementing a new growing season concept. The 2004-2005 averaged annual total biogenic volatile organic compound (BVOC) emissions for the Pan-European domain are estimated to be about 12 Tg with a large contribution from the OVOC class of about 4.5 Tg and from monoterpenes of about 4 Tg. Annual isoprene emissions are found to be about 3.5 Tg, insensitive to the chosen emission algorithm. Emissions of OVOC were found to originate to a large extent from agriculture. Further experiments on crop emissions should be carried out to check the validity of the applied standard emission factors. The new inventory aims at a fully transparent and verifiable aggregation of detailed land use information and at the inclusion of plant-specific emission data. Though plant-specific land use data is available with relatively high accuracy, a lack of experimental biomass densities and emission data on terpenes, sesquiterpenes and oxygenated VOC, in particular for agricultural plants, currently limits the setup of a highly accurate plant-specific emission inventory.

Karl, M.; Guenther, A.; Köble, R.; Leip, A.; Seufert, G.

2009-06-01

213

The impact of air pollutant and methane emission controls on tropospheric ozone and radiative forcing: CTM calculations for the period 1990-2030  

NASA Astrophysics Data System (ADS)

To explore the relationship between tropospheric ozone and radiative forcing with changing emissions, we compiled two sets of global scenarios for the emissions of the ozone precursors methane (CH4), carbon monoxide (CO), non-methane volatile organic compounds (NMVOC) and nitrogen oxides (NOx) up to the year 2030 and implemented them in two global Chemistry Transport Models. The "Current Legislation" (CLE) scenario reflects the current perspectives of individual countries on future economic development and takes the anticipated effects of presently decided emission control legislation in the individual countries into account. In addition, we developed a "Maximum technically Feasible Reduction" (MFR) scenario that outlines the scope for emission reductions offered by full implementation of the presently available emission control technologies, while maintaining the projected levels of anthropogenic activities. Whereas the resulting projections of methane emissions lie within the range suggested by other greenhouse gas projections, the recent pollution control legislation of many Asian countries, requiring introduction of catalytic converters for vehicles, leads to significantly lower growth in emissions of the air pollutants NOx, NMVOC and CO than was suggested by the widely used and more pessimistic IPCC (Intergovernmental Panel on Climate Change) SRES (Special Report on Emission Scenarios) scenarios (Nakicenovic et al., 2000), which made Business-as-Usual assumptions regarding emission control technology. With the TM3 and STOCHEM models we performed several long-term integrations (1990-2030) to assess global, hemispheric and regional changes in CH4, CO, hydroxyl radicals, ozone and the radiative climate forcings resulting from these two emission scenarios. Both models reproduce broadly the observed trends in CO, and CH4 concentrations from 1990 to 2002.

For the "current legislation" case, both models indicate an increase of the annual average ozone levels in the Northern Hemisphere by 5ppbv, and up to 15ppbv over the Indian sub-continent, comparing the 2020s (2020-2030) with the 1990s (1990-2000). The corresponding higher ozone and methane burdens in the atmosphere increase radiative forcing by approximately 0.2 Wm-2. Full application of today's emissions control technologies, however, would bring down ozone below the levels experienced in the 1990s and would reduce the radiative forcing of ozone and methane to approximately -0.1 Wm-2. This can be compared to the 0.14-0.47 Wm-2 increase of methane and ozone radiative forcings associated with the SRES scenarios. While methane reductions lead to lower ozone burdens and to less radiative forcing, further reductions of the air pollutants NOx and NMVOC result in lower ozone, but at the same time increase the lifetime of methane. Control of methane emissions appears an efficient option to reduce tropospheric ozone as well as radiative forcing.

Dentener, F.; Stevenson, D.; Cofala, J.; Mechler, R.; Amann, M.; Bergamaschi, P.; Raes, F.; Derwent, R.

2005-07-01

214

Multiyear trends in volatile organic compounds in Los Angeles, California: Five decades of decreasing emissions  

NASA Astrophysics Data System (ADS)

Airborne measurements of volatile organic compounds (VOCs) were performed during CalNex 2010 (California Research at the Nexus of Air Quality and Climate Change) in the Los Angeles (LA) basin in May-June 2010 and during ITCT2k2 (Intercontinental Transport and Chemical Transformation) in May 2002. While CO2 enhancements in the basin were similar between the two years, the ?CO/?CO2 ratio had decreased by about a factor of two. The ?VOC/?CO emission ratios stayed relatively constant between the two years. This indicates that, relative to CO2, VOCs in the LA basin also decreased by about a factor of two since 2002. These data are compared with the results from various previous field campaigns dating back as early as 1960 and from the extensive air quality monitoring system in the LA basin going back to 1980. The results show that the mixing ratios of VOCs and CO have decreased by almost two orders of magnitude during the past five decades at an average annual rate of about 7.5%. Exceptions to this trend are the small alkanes ethane and propane, which have decreased slower due to the use and production of natural gas. A comparison with trends in London, UK shows that, due to stricter regulations at the time, VOC mixing ratios in LA decreased earlier than in London, albeit at a slower rate, such that typical mixing ratios in both cities in 2008 were at about the same level.

Warneke, Carsten; de Gouw, Joost A.; Holloway, John S.; Peischl, Jeff; Ryerson, Thomas B.; Atlas, Elliot; Blake, Don; Trainer, Michael; Parrish, David D.

2012-09-01

215

Determination of gaseous semi- and low-volatile organic halogen compounds by barrier-discharge atomic emission spectrometry.  

PubMed

A group parameter approach using "total organic halogen" is effective for monitoring gaseous organic halogen compounds, including fluorine, chlorine, and bromine compounds, generated from combustion. We described the use of barrier-discharge radiofrequency-helium-plasma/atomic emission spectrometry, for the detection of semi- and low-volatile organic halogen compounds (SLVOXs), which can be collected by Carbotrap adsorbents and analyzed using thermal desorption. The optimal carrier gas flow rates at the injection and desorption lines were established to be 100 mL/min. The detection range for SLVOXs in the gaseous samples was from 10 ng to tens of micrograms. Measuring F was more difficult than measuring C1 or Br, because the wavelength of F is close to that of air. The barrier-discharge radiofrequency-helium-plasma/atomic emission spectrometry measured from 85% to 103% of the SLVOXs in the gas sample. It has been found that Carbotrap B is appropriate for high-boiling-point compounds, and Carbotrap C is suitable for the determination of organic halogen compounds with lower boiling points, in the range 200-2300C. Under optimal analysis conditions, a chlorine-containing plastic was destroyed using different oxygen concentrations. Lower oxygen concentrations resulted in the production of lower amounts of organic halogen compounds. PMID:23586317

Sun, Yifei; Watanabe, Nobuhisa; Wang, Wei; Zhu, Tianle

2013-01-01

216

Real-world emissions of carbonyl compounds from in-use heavy-duty diesel trucks and diesel Back-Up Generators (BUGs)  

Microsoft Academic Search

Emissions of carbonyl compounds such as formaldehyde, acetaldehyde, and acrolein are of interest to the scientific and regulatory communities due to their suspected or likely impacts on human health. The present work investigates emissions of carbonyl compounds from nine Class 8 heavy-duty diesel (HDD) tractors and also from nine diesel-powered backup generators (BUGs); the former were chosen because of their

Aniket A. Sawant; Sandip D. Shah; Xiaona Zhu; J. Wayne Miller; David R. Cocker

2007-01-01

217

Influence of bio-fuels on passenger car vehicle emissions  

NASA Astrophysics Data System (ADS)

In order to reduce the emissions of air pollutants, vehicles design and fuel formulation have changed. Ultra clean vehicle technologies started to be used in increased number. As a result, the emissions composition is expected to change as well. The use of new technologies and new fuels require new emissions tests especially for non-regulated compounds. The interest in using bio fuels as alternative fuels for petroleum-based ones has increased constantly in the last years. The advantages of the bio fuels usage is given by their similar proprieties, characteristics of renew ability, biodegradability and potential beneficial effects on the exhaust emission. The study involved measurements on a roller test facility of a reference passenger car representing new technologies (emission standards, injection system). The vehicle operated by use of reference gasoline and reference gasoline blended (10 and 20%) with bio-ethanol (EtOH). The measurements used different driving cycles: ARTEMIS cycle, real world driving cycle, NEDC cycle, the standard European driving cycle and additionally, a driving cycle consisting in Idle, 30, 50, 90 km/h. The sampling positions were before and after the catalyst and in the exhaust pipe. The detailed speciation of NMVOC' (non methane volatile organic compounds) was completed by use of active carbon tubes, DNPH (2,4-dinitrophenylhydrazine) tubes and cold traps. The particles were monitored by use of an on-line EEPS (Engine Exhaust Particle Sizer). CO2, NO, NO2 and NOX (NO +NO2) were continuously monitored by use of an on- line FTIR (Fourier transform infrared spectroscopy)- MEXA system. The investigations reveal that among the carbonylic compounds 15 oxygenated species were found in engine out exhaust and only 3 in tailpipe emissions, namely formaldehyde, acetaldehyde and acroleine. These are of great interest due to their impacts on human health. The hydrocarbons emissions decrease by increased of EtOH content. New compounds were observed. The nitro-compounds found in the after engine position by increased EtOH were no more found in the exhaust gas. The results show that total particle concentration, mass and diameter decreased substantially after catalyst and filter by increased ethanol blend.

Petrea, M.; Kapernaum, M.; Wahl, C.

2009-04-01

218

Emission characteristics of nitrogen- and sulfur-containing odorous compounds during different sewage sludge chemical conditioning processes.  

PubMed

Chemical conditioners are often used to enhance sewage sludge dewaterability through altering sludge properties and flocs structure, both affect odorous compounds emissions not only during sludge conditioning but also in subsequent sludge disposal. This study was to investigate emission characteristics of ammonia (NH(3)), sulfur dioxide (SO(2)), hydrogen sulfide (H(2)S) and carbonyl sulfide (COS) generated from sewage sludge conditioned by three representative conditioners, i.e., organic polymers, iron salts and skeleton builders, F-S (Fenton's reagent and skeleton builders) composite conditioner. The results demonstrate that polyacrylamide (PAM) has an insignificant effect on emission characteristics of nitrogen- and sulfur-containing odorous compounds, because the properties, sulfur and nitrogen speciations are similar in PAM-conditioned sludge and raw sludge (RS). Significant increases of SO(2) and H(2)S emissions in the H(2)SO(4) conditioning process were observed due to the accelerated decomposition of sulfur-containing amino acids in acidic environment. Fenton peroxidation facilitates the formation of COS. CaO can reduce sulfur-containing gases emission via generation of calcium sulfate. However, under strong alkaline conditions, free ammonia or protonated amine in sludge can be easily converted to volatile ammonia, resulting in a significant release of NH(3). PMID:22902143

Liu, Huan; Luo, Guang-Qian; Hu, Hong-Yun; Zhang, Qiang; Yang, Jia-Kuan; Yao, Hong

2012-08-07

219

Modeling the influence of biogenic volatile organic compound emissions on ozone concentration during summer season in the Kinki region of Japan  

Microsoft Academic Search

Tropospheric ozone adversely affects human health and vegetation, and biogenic volatile organic compound (BVOC) emission has potential to influence ozone concentration in summer season. In this research, the standard emissions of isoprene and monoterpene from the vegetation of the Kinki region of Japan, estimated from growth chamber experiments, were converted into hourly emissions for July 2002 using the temperature and

Hai Bao; Kundan Lal Shrestha; Akira Kondo; Akikazu Kaga; Yoshio Inoue

2010-01-01

220

Model for evaluation of refinery and synfuels VOC (volatile organic compounds) emission data. Volume 1. Technical report and Appendix A. Final report, June 1983September 1984  

Microsoft Academic Search

The report describes the development of a model for estimating emissions of volatile organic compounds (VOCs) from petroleum refineries and synfuel plants. The model, responding to a need to define a consistent and comprehensive approach for estimating VOC emissions from these two sources, is a modular technique in which the entire spectrum of potential VOC emissions sources was defined in

R. G. Wetherold; G. E. Harris; F. D. Skinner; L. P. Provost

1985-01-01

221

Model for evaluation of refinery and synfuels VOC (volatile organic compounds) emission data. Volume 2. Appendices B and C. Final report, June 1983September 1984  

Microsoft Academic Search

The report describes the development of a model for estimating emissions of volatile organic compounds (VOCs) from petroleum refineries and synfuel plants. The model, responding to a need to define a consistent and comprehensive approach for estimating VOC emissions from these two sources, is a modular technique in which the entire spectrum of potential VOC emissions sources was defined in

R. G. Wetherold; G. E. Harris; F. D. Skinner; L. P. Provost

1985-01-01

222

An experimental and theoretical study of the effects of environmental conditions and nonlinear adsorption on the emission rates of volatile organic compounds from contaminated soils  

Microsoft Academic Search

Laboratory experiments were conducted to evaluate effects of soil moisture content, soil temperature, and air relative humidity on volatile organic compound (VOC) emission rates. Emission rates were substantially affected by changes in these variables representative of expected changes in the environment. Emission rates increased in response to increasing soil moisture content, soil temperature, air relative humidity, and in response to

Shonnard

1991-01-01

223

Detection of emission indices of aircraft exhaust compounds by open-path optical methods at airports  

Microsoft Academic Search

Air pollutant emission rates of aircrafts are determined with test bed measurements. Regulations exist for CO2, NO, NO2, CO concentrations, the content of total unburned hydrocarbons and the smoke number, a measure of soot. These emission indices are listed for each engine in a data base of the International Civil Aviation Organisation (ICAO) for four different Air pollutant emission rates

Gregor Schürmann; Klaus Schäfer; Carsten Jahn; Herbert Hoffmann; Selina Utzig

2005-01-01

224

Synchronous Scan and Excitation-Emission Matrix Fluorescence Spectroscopy of Water-Soluble Organic Compounds in Atmospheric Aerosols  

Microsoft Academic Search

Three-dimensional excitation–emission matrix (EEM) fluorescence spectra of water-soluble organic compounds (WSOC) from aerosol samples were measured and compared with those reported in the literature for natural dissolved organic matter. The EEM profiles of the WSOC presented three characteristic excitation\\/emission (?Exc\\/?Em) peaks: 240\\/405 nm, 310\\/405 nm and 280\\/340 nm. The fluorescence intensities at ?Exc\\/?Em˜240\\/405 nm and ?Exc\\/?Em˜310\\/405 nm are located at

Regina M. B. O. Duarte; Casimiro A. Pio; Armando C. Duarte

2004-01-01

225

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

SciTech Connect

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

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

1990-08-01

226

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

SciTech Connect

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

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

1990-08-01

227

Study of Volatile Organic Compound Emissions from Consumer and Commercial Products. Volume 2. Comprehensive Emissions Inventory. Report to Congress.  

National Technical Information Service (NTIS)

The primary purpose of the study and report to Congress is to educate the EPA and Congress on consumer and commercial products as contributors to ozone nonattainment and to identify opportunities for reduction of VOC emissions from the use of these produc...

1995-01-01

228

Air-surface exchange of nonmethane organic compounds at a grassland site: Seasonal variations and stressed emissions  

NASA Astrophysics Data System (ADS)

Emissions of nonmethane organic compounds (NMOCs) were measured by a static enclosure technique at a grassland site in the midwestern United States during the growing seasons over a 2-year period. A mixture of nonmethane hydrocarbons (NMHCs) and oxygenated hydrocarbons (OxHCs) was emitted from the surface at rates exhibiting large seasonal and year-to-year variations. The average emission rate (and standard error) of the total NMOCs around noontime on sunny days during the growing seasons for the 2-year period was 1,300±170 ?g m-2 h-1 (mass of the total NMOCs per area of enclosed soil surface per hour) or 5.5±0.9 ?g g-1 h-1 (mass of the total NMOCs per mass of dry plant biomass in an enclosure per hour), with about 10% and 70% of the emissions being composed of tentatively identified NMHCs and OxHCs, respectively. Methanol was apparently derived from both the soil and vegetation and exhibited an average emission rate of 460±73 ?g m-2 h-1 (1.4±0.2 ?g g-1 h-1), which was the largest emission among the NMOCs. The year-to-year variation in the precipitation pattern greatly affected the NMOC emission rates. Emission rates normalized to biomass density exhibited a linear decrease as the growing season progressed. The emission rates of some NMOCs, particularly the OxHCs, from vegetation subjected to hypoxia, frost, and physical stresses were significantly greater than the average values observed at the site. Emissions of monoterpenes (?- and ?-pinene, limonene, and myrcene) and cis-3-hexen-l-ol were accelerated during the flowering of the plants and were much greater than those predicted by algorithms that correlated emission rates with temperature. Herbaceous vegetation is estimated to contribute about 40% and 50% of the total NMOC and monoterpene emissions, respectively, in grasslands; the remaining contributions are from woody species within grasslands. Contributions of isoprene emissions from herbaceous vegetation in grasslands are negligible. Grasslands are estimated to contribute about 10% of the total biogenic NMOC emissions in the United States.

Fukui, Yoshiko; Doskey, Paul V.

1998-06-01

229

[Volatile organic compounds (VOCs) emitted from wood furniture--estimation of emission rate by passive flux sampler].  

PubMed

The aim of this study was to evaluate aldehydes and other volatile organic compounds (VOCs) emission from furniture, which may cause hazardous influence on human being such as sick building/sick house syndrome. In this study, VOCs emitted from six kinds of wood furniture, including three set of dining tables and three beds, were analyzed by large chamber test method (JIS A 1911). Based on the emission rates of total VOCs (TVOC), the impacts on the indoor TVOC was estimated by the simulation model with volume of 20 m3 and ventilation frequency of 0.5 times/h. The estimated increment of formaldehyde were exceeded the guideline value (100 microg/m3) in one set of dining table and one bed. The estimated TVOC increment values were exceeded the provisional target value for indoor air (400 microg/m3) in two sets of dining tables and two beds. These results revealed that VOC emissions from wood furniture may influence significantly indoor air quality. Also, in this study, to establish the alternative method for large chamber test methods, emission rates from representative five areas of furniture unit were evaluated by passive sampling method using flux sampler and emission rate from full-sized furniture was predicted. Emission rates predicted by flux passive sampler were 10-106% (formaldehyde) and 8-141% (TVOC) of the data measured using large chamber test, respectively. PMID:22259847

Jinno, Hideto; Tanaka-Kagawa, Toshiko; Furuta, Mitsuko; Shibatsuji, Masayoshi; Nishimura, Tetsuji

2011-01-01

230

Characteristics of carbonyl compounds emission from a diesel-engine using biodiesel–ethanol–diesel as fuel  

Microsoft Academic Search

Characteristics of carbonyl compounds (carbonyls) emissions from biodiesel–ethanol–diesel (BE–diesel) were investigated in a Commins-4B diesel engine and compared with those from fossil diesel. Acetaldehyde was the most abundant carbonyls in the exhaust, followed by formaldehyde, acetone, propionaldehyde and benzaldehyde. Apliphatic carbonyls emitted from BE–diesel were higher than those from diesel fuel, while formaldehyde and aromatic carbonyls were less than those

Xiaobing Pang; Xiaoyan Shi; Yujing Mu; Hong He; Shijin Shuai; Hu Chen; Rulong Li

2006-01-01

231

Emissions of reduced sulphur compounds from the surface of primary and secondary wastewater clarifiers at a Kraft Mill  

Microsoft Academic Search

Emissions of reduced sulphur compounds (RSCs) from the primary and secondary clarifiers at a Kraft mill were measured for\\u000a respectively 8 and 22 days using a floating flux chamber. In the primary clarifier, dimethyl disulphide (DMDS) had the highest\\u000a mean flux (0.83 ?g s???1 m???2) among all RSCs, and the mean flux of total reduced sulphur (TRS) was 1.53 ?g  s???1 m???2. At the secondary clarifier,

Lionel Catalan; Victor Liang; Andrea Johnson; Charles Jia; Brian O’Connor; Chris Walton

2009-01-01

232

Volatile organic compound concentrations, emission rates, and source apportionment in newly-built apartments at pre-occupancy stage.  

PubMed

The present study investigated the indoor concentrations of selected volatile organic compounds (VOCs) and formaldehyde and their indoor emission characteristics in newly-built apartments at the pre-occupancy stage. In total, 107 apartments were surveyed for indoor and outdoor VOC concentrations in two metropolitan cities and one rural area in Korea. A mass balanced model was used to estimate surface area-specific emission rates of individual VOCs and formaldehyde. Seven (benzene, ethyl benzene, toluene, m,p-xylene, o-xylene, n-hexane, and n-heptane) of 40 target compounds were detectable in all indoor air samples, whereas the first five were detected in all outdoor air samples. Formaldehyde was also predominant in the indoor air samples, with a high detection frequency of 96%. The indoor concentrations were significantly higher than the outdoor concentrations for aromatics, alcohols, terpenes, and ketones. However, six halogenated VOCs exhibited similar concentrations for indoor and outdoor air samples, suggesting that they are not major components emitted from building materials. It was also suggested that a certain portion of the apartments surveyed were constructed by not following the Korean Ministry of Environment guidelines for formaldehyde emissions. Toluene exhibited the highest emission rate with a median value of 138 ?g m(-2) h(-1). The target compounds with median emission rates greater than 20 ?g m(-2) h(-1) were toluene, 1-propanol, formaldehyde, and 2-butanone. The wood panels/vinyl floor coverings were the largest indoor pollutant source, followed by floorings, wall coverings, adhesives, and paints. The wood panels/vinyl floor coverings contributed nearly three times more to indoor VOC concentrations than paints. PMID:22698369

Shin, Seung H; Jo, Wan K

2012-06-12

233

Carbonyl compounds and PAH emissions from CNG heavy-duty engine  

Microsoft Academic Search

Previous works carried out in Istituto Motori laboratories have shown that natural gas is a suitable fuel for general means of transportation. This is because of its favorable effects on engine performance and pollutant emissions. The natural gas fueled engine provided the same performance as the diesel engine, met R49 emission standards, and showed very low smoke levels. On the

M. Gambino; R. Cericola; P. Corbo; S. Iannaccone

1993-01-01

234

Volatile organic compounds (VOCs) measured at an urban site of Beijing: intercomparisons, emission ratios and factor analysis  

NASA Astrophysics Data System (ADS)

A proton transfer reaction mass spectrometer (PTR-MS) were used to measure volatile organic compounds (VOCs) in August - September, 2010 (summer) and December, 2010 - January, 2011 (winter) at an urban site on campus of Peking University. During the summer campaign, other instruments were also deployed at the site, including a custom-built GC-MS/FID, a GC-FID/PID, whole air samples (WAS) collected in canisters, and DNPH cartridges. VOCs concentrations measured by PTR-MS in the summer campaign compared well with the GC methods for most of the measured compounds. VOCs concentrations in winter strongly correlated with the combustion tracer CO for both hydrocarbons and oxygenates VOCs (OVOCs) and emission ratios to CO were calculated from linear fits of ambient concentrations. Emission ratios of aromatics in winter were significantly lower than those in summer, which may be due to: (1) higher CO emissions from coal burning for space heating in winter of Beijing; (2) higher industrial/solvent evaporations of aromatics in summer. The VOCs dataset with 19 species from PTR-MS and 56 species from GC-MS/FID was used for PMF analysis. A solution of five factors with no rotation (fPeak=0) was determined to be the best fit. Uncertainties of PMF analysis were explored by bootstrap method. The five factors included a fresh primary emissions factor (Factor 1, 27%), an aged primary emissions factor (Factor 2, 19%), a secondary & aged factor (Factor 3, 33%), a biogenic factor (Factor 4, 4%) and an industrial-like factor (Factor 5, 17%). The fresh and aged primary factor correlated well with NOx and CO, respectively. And the secondary & aged factor correlated well with PAN and Ox (O3+NO2). The contributions in different factors for various hydrocarbons are dependent on their reactivity. Comparing the obtained factor profiles shows that the aged primary emission factor and the secondary & aged factor are photochemically connected with the fresh primary emission factor. It suggested that PMF can provide information of photochemical processes in the atmosphere. The biogenic factor has a low MVK+MACR/isoprene ratio (0.506), indicating that it represents very fresh biogenic emissions and only transport no more than 0.5 hour in the urban environment.

Yuan, B.; Shao, M.; De Gouw, J. A.; Bon, D.; Wang, M.; Lu, S.; Zeng, L.; Zhang, Q.; Liu, Y.

2011-12-01

235

Effects of a combined Diesel particle filter-DeNOx system (DPN) on reactive nitrogen compounds emissions: a parameter study.  

PubMed

The impact of a combined diesel particle filter-deNO(x) system (DPN) on emissions of reactive nitrogen compounds (RNCs) was studied varying the urea feed factor (?), temperature, and residence time, which are key parameters of the deNO(x) process. The DPN consisted of a platinum-coated cordierite filter and a vanadia-based deNO(x) catalyst supporting selective catalytic reduction (SCR) chemistry. Ammonia (NH?) is produced in situ from thermolysis of urea and hydrolysis of isocyanic acid (HNCO). HNCO and NH? are both toxic and highly reactive intermediates. The deNO(x) system was only part-time active in the ISO8178/4 C1cycle. Urea injection was stopped and restarted twice. Mean NO and NO? conversion efficiencies were 80%, 95%, 97% and 43%, 87%, 99%, respectively, for ? = 0.8, 1.0, and 1.2. HNCO emissions increased from 0.028 g/h engine-out to 0.18, 0.25, and 0.26 g/h at ? = 0.8, 1.0, and 1.2, whereas NH? emissions increased from <0.045 to 0.12, 1.82, and 12.8 g/h with maxima at highest temperatures and shortest residence times. Most HNCO is released at intermediate residence times (0.2-0.3 s) and temperatures (300-400 °C). Total RNC efficiencies are highest at ? = 1.0, when comparable amounts of reduced and oxidized compounds are released. The DPN represents the most advanced system studied so far under the VERT protocol achieving high conversion efficiencies for particles, NO, NO?, CO, and hydrocarbons. However, we observed a trade-off between deNO(x) efficiency and secondary emissions. Therefore, it is important to adopt such DPN technology to specific application conditions to take advantage of reduced NO(x) and particle emissions while avoiding NH? and HNCO slip. PMID:23214996

Heeb, Norbert V; Haag, Regula; Seiler, Cornelia; Schmid, Peter; Zennegg, Markus; Wichser, Adrian; Ulrich, Andrea; Honegger, Peter; Zeyer, Kerstin; Emmenegger, Lukas; Zimmerli, Yan; Czerwinski, Jan; Kasper, Markus; Mayer, Andreas

2012-12-05

236

Retrofitted Biotrickling Filters for Odor, VOC, H2S and Reduced Sulfur Compound Emission Control  

Microsoft Academic Search

This paper evaluates treatment of odorous compounds (hydrogen sulfide, reduced sulfur compounds, VOCs, ammonia, and total odor) in wet chemical scrubbers that were converted to biotrickling filters at the Orange County Sanitation District (OCSD), California. Results of over two years of continuous operation in five biotrickling filters are discussed. The biotrickling filters were usually operated at a gas contact time

Marc A. Deshusses; Vladimir Kogan; David Gabriel; Johannes M. Strauss; Jeffrey Brown; Edward Torres

237

Volatile organic compound emissions in relation to plant carbon fixation and the terrestrial carbon budget  

Microsoft Academic Search

A substantial amount of carbon is emitted by terrestrial vegetation as biogenic volatile organic compounds (VOC), which contributes to the oxidative capacity of the atmosphere, to particle production and to the carbon cycle. With regard to the carbon budget of the terrestrial biosphere, a release of these carbon compounds is regarded as a loss of photosynthetically fixed carbon. The significance

Jürgen Kesselmeier; Paolo Ciccioli; Uwe Kuhn; Paolo Stefani; Thomas Biesenthal; Stefanie Rottenberger; Annette Wolf; Marina Vitullo; Ricardo Valentini; Antonio Nobre; Pavel Kabat; Meinrat O. Andreae

2002-01-01

238

Final Report on Testing of Off-Gas Treatment Technologies for Abatement of Atmospheric Emissions of Chlorinated Volatile Organic Compounds  

SciTech Connect

The purpose of this report is to summarize the results of the program for off-gas treatment of atmospheric emissions of chlorinated volatile organic compounds (CVOCs), in particular trichloroethylene (TCE) and perchloroethylene (PCE). This program was funded through the Department of Energy Office of Technology Development`s VOC`s in Non-Arid Soils Integrated Demonstration (VNID). The off-gas treatment program was initiated after testing of in-situ air stripping with horizontal wells was completed (Looney et al., 1991). That successful test expectedly produced atmospheric emissions of CVOCs that were unabated. It was decided after that test that an off-gas treatment is an integral portion of remediation of CVOC contamination in groundwater and soil but also because several technologies were being developed across the United States to mitigate CVOC emissions. A single platform for testing off-gas treatment technologies would facilitate cost effective evaluation of the emerging technologies. Another motivation for the program is that many CVOCs will be regulated under the Clean Air Act Amendments of 1990 and are already regulated by many state regulatory programs. Additionally, compounds such as TCE and PCE are pervasive subsurface environmental contaminants, and, as a result, a small improvement in terms of abatement efficiency or cost will significantly reduce CVOC discharges to the environment as well as costs to United States government and industry.

Jarosch, T.R.; Haselow, J.S.; Rossabi, J.; Burdick, S.A.; Raymond, R.; Young, J.E.; Lombard, K.H.

1995-01-23

239

Emissions of non-methane organic compounds from a grassland site.  

National Technical Information Service (NTIS)

A mixture of oxygenated hydrocarbons (OxHCs), isoprene, and monoterpenes was detected in the emissions from a grassland site in the Midwestern United States. A plot dominated by crown vetch (Coronilla varia) and bluegrass (Poa spp.), exhibited a constant ...

Y. Fukui P. V. Doskey

1996-01-01

240

Kinetic model of atomic and molecular emissions in laser-induced breakdown spectroscopy of organic compounds  

Microsoft Academic Search

A kinetic model previously developed to predict the relative intensities of atomic emission lines in laser-induced breakdown\\u000a spectroscopy has been extended to include processes related to CN and C2 molecular emissions. Simulations with this model were performed to predict the relative excited-state populations. The results\\u000a from the simulations are compared with experimentally determined excited-state populations from 1,064 nm laser irradiation\\u000a of

Qianli Ma; Paul J. Dagdigian

241

Detection of emission indices of aircraft exhaust compounds by open-path optical methods at airports  

NASA Astrophysics Data System (ADS)

Air pollutant emission rates of aircrafts are determined with test bed measurements. Regulations exist for CO2, NO, NO2, CO concentrations, the content of total unburned hydrocarbons and the smoke number, a measure of soot. These emission indices are listed for each engine in a data base of the International Civil Aviation Organisation (ICAO) for four different Air pollutant emission rates of aircrafts are determined with test bed measurements. Regulations exist for CO2, NO, NO2, CO concentrations, the content of total unburned hydrocarbons and the smoke number, a measure of soot. These emission indices are listed for each engine in a data base of the International Civil Aviation Organisation (ICAO) for four different thrust levels (Idle, approach, cruise and take-off). It is a common procedure to use this data base as a starting point to estimate aircraft emissions at airports and further on to calculate the contribution of airports on local air quality. The comparison of these indices to real in use measurements therefore is a vital task to test the quality of air quality models at airports. Here a method to determine emission indices is used, where concentration measurements of CO2 together with other pollutants in the aircraft plume are needed. During intensive measurement campaigns at Zurich (ZRH) and Paris Charles De Gaulle (CDG) airports, concentrations of CO2, NO, NO2 and CO were measured. The measurement techniques were Fourier-Transform-Infrared (FTIR) spectrometry and Differential Optical Absorption Spectroscopy (DOAS). The big advantage of these methods is that no operations on the airport are influenced during measurement times. Together with detailed observations of taxiway movements, a comparison of emission indices with real in use emissions is possible.

Schürmann, Gregor; Schäfer, Klaus; Jahn, Carsten; Hoffmann, Herbert; Utzig, Selina

2005-10-01

242

Carbonyl compound emissions from a heavy-duty diesel engine fueled with diesel fuel and ethanol-diesel blend.  

PubMed

This paper presents an investigation of the carbonyl emissions from a direct injection heavy-duty diesel engine fueled with pure diesel fuel (DF) and blended fuel containing 15% by volume of ethanol (E/DF). The tests have been conducted under steady-state operating conditions at 1200, 1800, 2600 rpm and idle speed. The experimental results show that acetaldehyde is the most predominant carbonyl, followed by formaldehyde, acrolein, acetone, propionaldehyde and crotonaldehyde, produced from both fuels. The emission factors of total carbonyls vary in the range 13.8-295.9 mg(kWh)(-1) for DF and 17.8-380.2mg(kWh)(-1) for E/DF, respectively. The introduction of ethanol into diesel fuel results in a decrease in acrolein emissions, while the other carbonyls show general increases: at low engine speed (1200 rpm), 0-55% for formaldehyde, 4-44% for acetaldehyde, 38-224% for acetone, and 5-52% for crotonaldehyde; at medium engine speed (1800 rpm), 106-413% for formaldehyde, 4-143% for acetaldehyde, 74-113% for acetone, 114-1216% for propionaldehyde, and 15-163% for crotonaldehyde; at high engine speed (2600 rpm), 36-431% for formaldehyde, 18-61% for acetaldehyde, 22-241% for acetone, and 6-61% for propionaldehyde. A gradual reduction in the brake specific emissions of each carbonyl compound from both fuels is observed with increase in engine load. Among three levels of engine speed employed, both DF and E/DF emit most CBC emissions at high engine speed. On the whole, the presence of ethanol in diesel fuel leads to an increase in aldehyde emissions. PMID:20416922

Song, Chonglin; Zhao, Zhuang; Lv, Gang; Song, Jinou; Liu, Lidong; Zhao, Ruifen

2010-04-22

243

Canopy light cues affect emission of constitutive and methyl jasmonate-induced volatile organic compounds in Arabidopsis thaliana.  

PubMed

The effects of plant competition for light on the emission of plant volatile organic compounds (VOCs) were studied by investigating how different light qualities that occur in dense vegetation affect the emission of constitutive and methyl-jasmonate-induced VOCs. Arabidopsis thaliana Columbia (Col-0) plants and Pieris brassicae caterpillars were used as a biological system to study the effects of light quality manipulations on VOC emissions and attraction of herbivores. VOCs were analysed using gas chromatography-mass spectrometry and the effects of light quality, notably the red : far red light ratio (R : FR), on expression of genes associated with VOC production were studied using reverse transcriptase-quantitative PCR. The emissions of both constitutive and methyl-jasmonate-induced green leaf volatiles and terpenoids were partially suppressed under low R : FR and severe shading conditions. Accordingly, the VOC-based preference of neonates of the specialist lepidopteran herbivore P. brassicae was significantly affected by the R : FR ratio. We conclude that VOC-mediated interactions among plants and between plants and organisms at higher trophic levels probably depend on light alterations caused by nearby vegetation. Studies on plant-plant and plant-insect interactions through VOCs should take into account the light quality within dense stands when extrapolating to natural and agricultural field conditions. PMID:23845065

Kegge, Wouter; Weldegergis, Berhane T; Soler, Roxina; Eijk, Marleen Vergeer-Van; Dicke, Marcel; Voesenek, Laurentius A C J; Pierik, Ronald

2013-07-12

244

? 13C and ?D of volatile organic compounds in an alumina industry stack emission  

Microsoft Academic Search

Compound specific isotope analysis (CSIA) is becoming more widely accepted as a tool for determining the sources of contaminants and monitoring their transport and fate in the environment. However, measuring ?D of volatile organic compounds (VOCs) in atmospheric samples is still underexplored. The present study applies thermal desorption–gas chromatography–isotope ratio mass spectrometry (TD–GC–irMS) for the first time to measure stable

Christiane Vitzthum von Eckstaedt; Kliti Grice; Marisa Ioppolo-Armanios; Mark Jones

2011-01-01

245

Emissions and Secondary Organic Aerosol Production from Semivolatile and Intermediate Volatility Organic Compounds  

Microsoft Academic Search

Organic aerosols are a highly-dynamic system dominated by both variable gas-particle partitioning and chemical evolution. Important classes of organics include semivolatile and intermediate volatility organic compounds (SVOC and IVOC, respectively). SVOCs are compounds that exist in both the gas and particle phases at typical atmospheric conditions while IVOC are low-volatility vapors that exist exclusively in the gas phase. Both classes

A. L. Robinson; A. A. Presto; M. A. Miracolo; N. M. Donahue; J. H. Kroll; D. R. Worsnop

2008-01-01

246

Kinetic model of C/H/N/O emissions in laser-induced breakdown spectroscopy of organic compounds  

SciTech Connect

A kinetic model to predict the relative intensities of the atomic C/H/N/O emission lines in laser-induced breakdown spectroscopy (LIBS) has been developed for organic compounds. The model includes a comprehensive set of chemical processes involving both neutral and ionic chemistry and physical excitation and de-excitation of atomic levels affecting the neutral, ionic, and excited-state species concentrations. The relative excited-state atom concentrations predicted by this modeling are compared with those derived from the observed LIBS intensities for 355 nm ns laser irradiation of residues of two organic compounds on aluminum substrate. The model reasonably predicts the relative excited-state concentrations, as well as their time profiles. Comparison of measured and computed concentrations has also allowed an estimation of the degree of air entrainment.

Dagdigian, Paul J.; Khachatrian, Ani; Babushok, Valeri I.

2010-05-01

247

Organic Liquids Storage Tanks Volatile Organic Compounds (VOCS) Emissions Dispersion and Risk Assessment in Developing Countries: The Case of Dar-Es-Salaam City, Tanzania  

Microsoft Academic Search

The emission estimation of nine volatile organic compounds (VOCs) from eight organic liquids storage tanks companies in Dar-es-Salaam\\u000a City Tanzania has been done by using US EPA standard regulatory storage tanks emission model (TANKS 4.9b). Total VOCs atmospheric\\u000a emission has been established to be 853.20 metric tones\\/yr. It has been established further that petrol storage tanks contribute\\u000a about 87% of

Msafiri M. Jackson

2006-01-01

248

Industrial Volatile Organic Compounds (VOC) model: Regionalized projections of uncontrolled VOC emissions by source category  

SciTech Connect

In the National Acid Precipitation Assessment Program (NAPAP), Task Group B (TG-B) is responsible for developing and testing models that can be used to project fuel use and air pollutant emissions by energy use sector. As discussed in the Foreword, this work is being carried out in two phases. All activities described in this report have taken place under Phase 1 of the TG-B program. This report addresses one aspect of the system designed to supply energy-economic driver data to the TG-B emissions model set: regionalized projections of uncontrolled industrial VOC emissions by source category. The components of the energy-economic driver module are shown. 6 refs., 4 figs., 5 tabs.

South, D.W.; McDonald, J.F.; Bragen, M.J.; Boyd, G.A.; Hanson, D.A.; Rothman, D.S.

1988-11-01

249

Ambient Concentrations and Emissions of a Comprehensive Suite of Volatile Organic Compounds at the CalNex-Bakersfield Supersite  

NASA Astrophysics Data System (ADS)

Ambient concentrations of ~250 Volatile Organic Compounds (VOCs) were measured hourly via in-situ gas chromatography at the Bakersfield, CA supersite in May & June 2010 as part of the California at the Nexus between Air Quality and Climate Change (CalNex) Experiment. Measurements included anthropogenic and biogenic VOCs containing 1 to 17 carbon atoms and a variety of functional groups (e.g. aldehydes, ketones, alcohols, halogens, sulfur, & nitrogen). We quantified a very broad range of primary gas-phase organics that lead to the formation of secondary organic aerosol (SOA) and tropospheric ozone, and we also observed many gas-phase products of VOC photooxidation. Many of the observed VOCs are volatile and have been measured previously, but in this experiment we tailored the instrumentation to also measure compounds in the intermediate volatility range, which are thought to contribute significantly to SOA and have rarely or never been reported from in-situ measurements. Among the observed gas-phase VOCs with lower volatility are PAHs (e.g. naphthalene, methylnaphthalenes, and dimethylnaphthalenes), alkanes up to 17 carbon atoms, aromatics and cycloalkanes with multiple alkyl groups, and functionalized VOCs with lower volatility. Analyses of the diurnal variability, covariance between compounds, weekday/weekend differences, and statistical analyses for source apportionment such as Positive Matrix Factorization (PMF) will be utilized to establish the major sources of these compounds and estimate regional emissions. Our VOC data provides excellent context for analysis of the broad array of gas and particle phase measurements during CalNex2010, which will be used to elucidate the chemistry leading to formation of SOA and tropospheric ozone in this polluted region of California with diverse urban, industrial, agricultural, and natural emission sources.

Gentner, D. R.; Goldstein, A. H.

2010-12-01

250

Biogenic emissions and ambient concentrations of hydrocarbons, carbonyl compounds and organic acids from ponderosa pine and cottonwood trees at rural and forested sites in Central New Mexico  

Microsoft Academic Search

Direct emission rates of carbonyl compounds, carboxylic acids and hydrocarbons from Populus fremontil (cottonwood) and Pinus ponderosa (ponderosa pine) trees were studied during the summer of 1997. Ambient air concentrations of these compounds in the vicinity of the sampled trees were also identified and quantified. Study sites were Socorro, NM and Langmuir Laboratory, NM a rural and forested, high mountain

Ignacio Villanueva-Fierro; Carl J Popp; Randal S Martin

2004-01-01

251

Volatile organic compounds from vegetation in southern Yunnan Province, China: Emission rates and some potential regional implications  

NASA Astrophysics Data System (ADS)

Little information is currently available regarding emissions of biogenic volatile organic compounds (BVOCs) in southern Asia. To address the need for BVOC emission estimates in regional atmospheric chemistry simulations, 95 common plant species were screened for emissions of BVOC in and near the Xishuangbanna Tropical Biological Gardens in southern Yunnan Province, Peoples' Republic of China in February 2003. In situ measurements with leaf cuvettes and branch bag enclosures were used in combination with portable gas chromatography, flame ionization, photoionization, and mass spectral detection to identify and quantify BVOC emissions. Forty-four of the species examined emitted isoprene at rates exceeding 20 ?g C g -1 (leaf dry weight) h -1. An emphasis was placed on the genus Ficus, which is important in the region and occupies a wide range of ecological niches. Several species in the footprint of a nearby flux tower were also examined. Several palm species and an abundant fern ( Cyclosorus parasiticus) emitted substantial amounts of isoprene, and probably accounted for observed daytime mean isoprene fluxes from the understory of a Hevea brasiliensis plantation of 1.0 and 0.15 mg C m -2 h -1 during the wet and dry seasons, respectively. These measurements verify that both the forest floor and canopy in this region can be sources of isoprene. Monoterpene emissions exceeded 1.0 ?g-C g -1 (leaf dry weight) h -1 from only 4 of 38 species surveyed, including some Ficus species and H. brasiliensis. However most of the trees of the latter species were sparsely foliated due to dry season senescence, and emission factors are approximately an order of magnitude lower than those reported during the wet season. BVOC emission rates and physiology of many species are impacted by reduced moisture availability, especially Mangifera indica. South Asia is a region undergoing rapid landuse change and forest plantation establishment, with large increases in area of high BVOC-emitting species in the genera Bambusa, Elaeis, Eucalyptus, Hevea, Pinus, and Populus (among others). This could result in profound changes in atmospheric chemistry in these regions, for instance, terpene emissions from H. brasiliensis could increase wet season biogenic organic aerosol burdens by approximately a factor of 2 in the Xishuangbanna region. Increases in plantation area established with high isoprene emitting species, (e.g. Bambusa spp. and Eucalyptus spp.) are also projected for China and other parts of Southeast Asia in the near future. Thus, landcover change in South Asian landscapes is usually associated with large increases in BVOC flux with the potential to alter the atmospheric chemical composition and air quality over this rapidly developing region.

Geron, Chris; Owen, Sue; Guenther, Alex; Greenberg, Jim; Rasmussen, Rei; Hui Bai, Jian; Li, Qing-Jun; Baker, Brad

252

Volatile acetic acid and formaldehyde emission from plywood treated with boron compound  

Microsoft Academic Search

The effects of plywood on formaldehyde and volatile acetic acid emissions treated with borax and boric acid were investigated. The treated plywood samples were manufactured by using two different methods; each veneer was first impregnated by a dipping method before the first group of plywood was manufactured. The second group of plywood panels was produced by adding preservatives (borax, boric

S. Colak; G. Colakoglu

2004-01-01

253

77 FR 10424 - Approval and Promulgation of Implementation Plans; Wisconsin; Volatile Organic Compound Emission...  

Federal Register 2010, 2011, 2012, 2013

...the use of add-on control, the required overall control efficiency of 90 percent...EPA's 1996 CTG for the Control of VOC Emissions from...used to clean spray guns and spray gun lines...materials containing no more than 0.8 pounds...

2012-02-22

254

Effect of Hydroxylated Compounds on Properties and Emission of Palm Biodiesel  

Microsoft Academic Search

The Malaysian Palm Oil Board (MPOB) attempted the search for a viable alternative fuel leading to a possible substitution to the conventional diesel since 1982, using palm oil derived fuel. Numerous studies have shown that most exhaust emission encountered with conventional diesel fuel are reduced with biodiesel,with the exception of nitrogen oxides (NOx). This paper is reported on the effect

Roila Awang; Choo Yuen May

2007-01-01

255

Emission of volatile organic compounds during composting of municipal solid wastes  

Microsoft Academic Search

The objective of this study was to identify and quantify volatile and semi-volatile organic compounds (VOCs) produced during composting of the organic fraction of municipal solid wastes (MSW). A laboratory experiment was conducted using organic components of MSW that were decomposed under controlled aerobic conditions. Mixed paper primarily produced alkylated benzenes, alcohols and alkanes. Yard wastes primarily produced terpenes, alkylated

Dimitris P Komilis; Robert K Ham; Jae K Park

2004-01-01

256

Volatile organic compound emissions from automobile refinishing: Background information for promulgated standards. Final report  

SciTech Connect

A final rule for the regulation of volatile organic compounds (VOC) from automobile refinishing is being promulgated under the authority of Section 183(e) of the Clean Air Act. This document contains comments received from the public, and the EPA`s responses to these comments.

NONE

1998-08-01

257

Volatile organic compound emissions from automobile refinishing. Background information for proposed standards. Draft report  

SciTech Connect

A draft rule for the regulation of volatile organic compounds (VOC) from automible refinishing is being proposed under the authority of Section 183(e) of the Clean Air Act. This document contains information on the automobile refinish industry, and presents control options and their associated environmental and cost impacts.

NONE

1995-08-01

258

EMISSION OF ORGANIC COMPOUNDS AND COMBUSTION GASES DURING HAZARDOUSWASTE COFIRING IN A WATERTUBE PACKAGE BOILER  

EPA Science Inventory

The primary objective of this study was to evaluate the sorptionand desorption of organic compounds on combustion-generated sootduring the cofiring of hazardous organics with fuel oil in afull-scale boiler. orption of organics was accomplished by firinga watertube package boiler ...

259

Microbial communities related to volatile organic compound emission in automobile air conditioning units.  

PubMed

During operation of mobile air conditioning (MAC) systems in automobiles, malodours can occur. We studied the microbial communities found on contaminated heat exchanger fins of 45 evaporators from car MAC systems which were operated in seven different regions of the world and identified corresponding volatile organic compounds. Collected biofilms were examined by scanning electron microscopy and fluorescent in situ hybridization. The detected bacteria were loosely attached to the metal surface. Further analyses of the bacteria using PCR-based single-strand conformation polymorphism and sequencing of isolated 16S rRNA gene fragments identified highly divergent microbial communities with multiple members of the Alphaproteobacteriales, Methylobacteria were the prevalent bacteria. In addition, Sphingomonadales, Burkholderiales, Bacillales, Alcanivorax spp. and Stenotrophomonas spp. were found among many others depending on the location the evaporators were operated. Interestingly, typical pathogenic bacteria related to air conditioning systems including Legionella spp. were not found. In order to determine the nature of the chemical compounds produced by the bacteria, the volatile organic compounds were examined by closed loop stripping analysis and identified by combined gas chromatography/mass spectrometry. Sulphur compounds, i.e. di-, tri- and multiple sulphides, acetylthiazole, aromatic compounds and diverse substituted pyrazines were detected. Mathematical clustering of the determined microbial community structures against their origin identified a European/American/Arabic cluster versus two mainly tropical Asian clusters. Interestingly, clustering of the determined volatiles against the origin of the corresponding MAC revealed a highly similar pattern. A close relationship of microbial community structure and resulting malodours to the climate and air quality at the location of MAC operation was concluded. PMID:23179618

Diekmann, Nina; Burghartz, Melanie; Remus, Lars; Kaufholz, Anna-Lena; Nawrath, Thorben; Rohde, Manfred; Schulz, Stefan; Roselius, Louisa; Schaper, Jörg; Mamber, Oliver; Jahn, Dieter; Jahn, Martina

2012-11-23

260

Geogenic and atmospheric sources for volatile organic compounds in fumarolic emissions from Mt. Etna and Vulcano Island (Sicily, Italy)  

NASA Astrophysics Data System (ADS)

In this paper, fluid source(s) and processes controlling the chemical composition of volatile organic compounds (VOCs) in gas discharges from Mt. Etna and Vulcano Island (Sicily, Italy) were investigated. The main composition of the Etnean and Volcano gas emissions is produced by mixing, to various degrees, of magmatic and hydrothermal components. VOCs are dominated by alkanes, alkenes and aromatics, with minor, though significant, concentrations of O-, S- and Cl(F)-substituted compounds. The main mechanism for the production of alkanes is likely related to pyrolysis of organic-matter-bearing sediments that interact with the ascending magmatic fluids. Alkanes are then converted to alkene and aromatic compounds via catalytic reactions (dehydrogenation and dehydroaromatization, respectively). Nevertheless, an abiogenic origin for the light hydrocarbons cannot be ruled out. Oxidative processes of hydrocarbons at relatively high temperatures and oxidizing conditions, typical of these volcanic-hydrothermal fluids, may explain the production of alcohols, esters, aldehydes, as well as O- and S-bearing heterocycles. By comparing the concentrations of hydrochlorofluorocarbons (HCFCs) in the fumarolic discharges with respect to those of background air, it is possible to highlight that they have a geogenic origin likely due to halogenation of both methane and alkenes. Finally, chlorofluorocarbon (CFC) abundances appear to be consistent with background air, although the strong air contamination that affects the Mt. Etna fumaroles may mask a possible geogenic contribution for these compounds. On the other hand, no CFCs were detected in the Vulcano gases, which are characterized by low air contribution. Nevertheless, a geogenic source for these compounds cannot be excluded on the basis of the present data.

Tassi, F.; Capecchiacci, F.; Cabassi, J.; Calabrese, S.; Vaselli, O.; Rouwet, D.; Pecoraino, G.; Chiodini, G.

2012-09-01

261

Particulate Matter Sampling and Volatile Organic Compound Removal for Characterization of Spark Ignited Direct Injection Engine Emissions  

SciTech Connect

More stringent emissions regulations are continually being proposed to mitigate adverse human health and environmental impacts of internal combustion engines. With that in mind, it has been proposed that vehicular particulate matter (PM) emissions should be regulated based on particle number in addition to particle mass. One aspect of this project is to study different sample handling methods for number based aerosol measurements, specifically, two different methods for removing volatile organic compounds (VOCs). One method is a thermodenuder (TD) and the other is an evaporative chamber/diluter (EvCh). These sample handling methods have been implemented in an engine test cell with a spark ignited direct injection (SIDI) engine. The engine was designed for stoichiometric, homogeneous combustion. SIDI is of particular interest for improved fuel efficiency compared to other SI engines, however, the efficiency benefit comes with greater PM emissions and may therefore be subject to the proposed number based PM regulation. Another aspect of this project is to characterize PM from this engine in terms of particle number and composition

Matthias, Nicholas; Farron, Carrie; Foster, David E.; Andrie, Michael; Krieger, Roger; Najt, Paul; Narayanaswamy, Kushal; Solomon, Arun S.; Zelenyuk, Alla

2012-01-01

262

Vapor deposition polymerization of vinyl compounds and fabrication of OLED having double emissive layers  

Microsoft Academic Search

Physical vapor deposition polymerization was achieved by evaporating vinyl monomers followed by heat treatment. This technique was utilized for preparing a hole-transport layer (HTL) and emissive layers (EMLs) of organic light emitting diodes (OLEDs). Adivinyl derivative of tetraphenyldiaminobiphenyl, DvTPD, was used both for the HTL and for the host material of red phosphorescent EML. A vinyl derivative of bis(N-carbazolyl)benzene, vmCP,

Eiji Otsuki; Hisaya Sato; Akira Kawakami; Hideo Taka; Hiroshi Kita; Hiroaki Usui

2009-01-01

263

Influence of particulate trap oxidizers on emission of mutagenic compounds by diesel automobiles.  

PubMed

Diesel exhaust particles are known to contain mutagenic and carcinogenic chemicals. The aim of this study was to determine whether, and to what extent, catalytic particulate trap oxidizers on light-duty diesel engines may reduce the emission of particle-associated mutagenic chemicals into the environment. Exhaust particles were collected from Mercedes Benz and Volkswagen diesel automobiles, equipped with or without the manufacturer's exhaust traps, while running on a chassis dynamometer under specified load conditions. Exhaust particles were collected from a dilution tunnel onto 20" X 20" Teflon-coated fiberglass filters. Mutagenesis tests of dichloromethane (DCM) extracts of the particles were conducted using the Ames Salmonella bacterial test system. The mutation rate was calculated in terms of histidine revertants per mile of travel during a set of standard test cycles. With both vehicles the traps produced an 87-92% reduction in the total amount of particulate material collected by the filters. There was no significant change in the specific mutagenic activity (revertants per microgram of DCM particle extract) with or without the traps. These studies support the notion that installation of exhaust traps which reduce particulate emission on diesel-powered vehicles will also reduce the emission of particle-associated mutagenic and carcinogenic materials into the environment. PMID:2473105

Rasmussen, R E; Devillez, G; Smith, L R

1989-06-01

264

Entrance channel dependent light-charged particle emission of the {sup 156}Er compound  

SciTech Connect

Light-charged particle decay from the {sup 156}Er compound nucleus, populated by {sup 12}C+{sup 144}Sm and {sup 60}Ni+{sup 96}Zr at the same excitation energy, were measured in coincidence with the evaporation residues. The high energy slope of charged particle spectra for the {sup 60}Ni-induced reaction is steeper than for the {sup 12}C-induced reaction. Model calculations including particle evaporation during compound nucleus formation result in good agreement with the data. This suggests that the difference in the charged particle spectra between the two entrance channels is due to a longer formation time in the {sup 60}Ni-induced reaction. 14 refs., 3 figs.

Liang, J.F.; Bierman, J.D.; Kelly, M.P.; Sonzogni, A.A.; Vandenbosch, R.; van Schagen, J.P.S. [Washington Univ., Seattle, WA (United States). Nuclear Physics Lab.

1996-09-01

265

Asian emissions in 2006 for the NASA INTEX-B mission  

NASA Astrophysics Data System (ADS)

A new inventory of air pollutant emissions in Asia in the year 2006 is developed to support the Intercontinental Chemical Transport Experiment-Phase B (INTEX-B) funded by the National Aeronautics and Space Administration (NASA). Emissions are estimated for all major anthropogenic sources, excluding biomass burning. We estimate total Asian anthropogenic emissions in the year 2006 as follows: 47.1 Tg SO2, 36.7 Tg NOx, 298.2 Tg CO, 54.6 Tg NMVOC, 29.2 Tg PM10, 22.2 Tg PM2.5, 2.97 Tg BC, and 6.57 Tg OC. We emphasize emissions from China because they dominate the Asia pollutant outflow to the Pacific and the increase of emissions from China since 2000 is of great concern. We have implemented a series of improved methodologies to gain a better understanding of emissions from China, including a detailed technology-based approach, a dynamic methodology representing rapid technology renewal, critical examination of energy statistics, and a new scheme of NMVOC speciation for model-ready emissions. We estimate China's anthropogenic emissions in the year 2006 to be as follows: 31.0 Tg SO2, 20.8 Tg NOx, 166.9 Tg CO, 23.2 Tg NMVOC, 18.2 Tg PM10, 13.3 Tg PM2.5, 1.8 Tg BC, and 3.2 Tg OC. We have also estimated 2001 emissions for China using the same methodology and found that all species show an increasing trend during 2001-2006: 36% increase for SO2, 55% for NOx, 18% for CO, 29% for VOC, 13% for PM10, and 14% for PM2.5, BC, and OC. Emissions are gridded at a resolution of 30 min×30 min and can be accessed at our web site (http://mic.greenresource.cn/intex-b2006).

Zhang, Q.; Streets, D. G.; Carmichael, G. R.; He, K. B.; Huo, H.; Kannari, A.; Klimont, Z.; Park, I. S.; Reddy, S.; Fu, J. S.; Chen, D.; Duan, L.; Lei, Y.; Wang, L. T.; Yao, Z. L.

2009-07-01

266

Carbonyl compounds emitted by a diesel engine fuelled with diesel and biodiesel-diesel blends: Sampling optimization and emissions profile  

NASA Astrophysics Data System (ADS)

Biodiesel is emerging as a renewable fuel, hence becoming a promising alternative to fossil fuels. Biodiesel can form blends with diesel in any ratio, and thus could replace partially, or even totally, diesel fuel in diesel engines what would bring a number of environmental, economical and social advantages. Although a number of studies are available on regulated substances, there is a gap of studies on unregulated substances, such as carbonyl compounds, emitted during the combustion of biodiesel, biodiesel-diesel and/or ethanol-biodiesel-diesel blends. CC is a class of hazardous pollutants known to be participating in photochemical smog formation. In this work a comparison was carried out between the two most widely used CC collection methods: C18 cartridges coated with an acid solution of 2,4-dinitrophenylhydrazine (2,4-DNPH) and impinger bottles filled in 2,4-DNPH solution. Sampling optimization was performed using a 2 2 factorial design tool. Samples were collected from the exhaust emissions of a diesel engine with biodiesel and operated by a steady-state dynamometer. In the central body of factorial design, the average of the sum of CC concentrations collected using impingers was 33.2 ppmV but it was only 6.5 ppmV for C18 cartridges. In addition, the relative standard deviation (RSD) was 4% for impingers and 37% for C18 cartridges. Clearly, the impinger system is able to collect CC more efficiently, with lower error than the C18 cartridge system. Furthermore, propionaldehyde was nearly not sampled by C18 system at all. For these reasons, the impinger system was chosen in our study. The optimized sampling conditions applied throughout this study were: two serially connected impingers each containing 10 mL of 2,4-DNPH solution at a flow rate of 0.2 L min -1 during 5 min. A profile study of the C1-C4 vapor-phase carbonyl compound emissions was obtained from exhaust of pure diesel (B0), pure biodiesel (B100) and biodiesel-diesel mixtures (B2, B5, B10, B20, B50, B75). The ?CC of the emission concentrations were 20.5 ppmV for B0 and 15.7 ppmV for B100. When considering fuel blends, the measured ?CC were 21.4 ppmV, 22.5 ppmV, 20.4 ppmV, 14.2 ppmV, 11.4 ppmV and 14.7 ppmV, respectively, for B2, B5, B10, B20, B50 and B75. Among the target CC, both formaldehyde and acetaldehyde were the major contributors to the observed total CC levels. Except for acrolein and formaldehyde, all CC showed a clear trend of reduction in the emissions from B2 to B100 (40% reduction, on average). Both individual and total CC emission factors (pg g -1 of fuel burnt) were calculated for all tested biodiesel-diesel blends. The lowest total CC emission factor (2271 pg g -1) was found when B50 was used; the individual emission factors determined (pg g -1) were: 539.7 (formaldehyde), 1411 (acetaldehyde), 30.83 (acrolein), and 310.7 (propionaldehyde).

Guarieiro, Lílian Lefol Nani; Pereira, Pedro Afonso de Paula; Torres, Ednildo Andrade; da Rocha, Gisele Olimpio; de Andrade, Jailson B.

267

Circadian rhythmicity in emission of volatile compounds by flowers of Rosa hybrida L. cv. Honesty  

Microsoft Academic Search

.   Quantitative headspace analyses of rose flowers showed no significant differences in composition of emitted volatile compounds\\u000a between flowers on the intact plant and cut flowers placed in vase water containing sucrose at 0, 15 or 30?g??l?1. Volatile components emitted were geraniol, nerol, citronellol, E-citral, Z-citral, methylgeranylate, trans-caryophyllene, ?-cubebene, dihydro-?-ionone, 2-phenylethanol, 2-phenylethylacetate, 3,5-dimethoxytoluene and hexylacetate.\\u000a When exposed to a 12-h

Johannes P. F. G. Helsper; Jacques A. Davies; Harro J. Bouwmeester; Aafke F. Krol; Maria H. van Kampen

1998-01-01

268

Emission of volatile organic compounds during composting of municipal solid wastes.  

PubMed

The objective of this study was to identify and quantify volatile and semi-volatile organic compounds (VOCs) produced during composting of the organic fraction of municipal solid wastes (MSW). A laboratory experiment was conducted using organic components of MSW that were decomposed under controlled aerobic conditions. Mixed paper primarily produced alkylated benzenes, alcohols and alkanes. Yard wastes primarily produced terpenes, alkylated benzenes, ketones and alkanes, while food wastes primarily produced sulfides, acids and alcohols. Among 13 aromatic VOCs found in MSW composting facilities, toluene, ethylbenzene, 1,4-dichlorobenzene, p-isopropyl toluene, and naphthalene were in the largest amounts. Unseeded mixed paper, seeded mixed paper, seeded yard wastes, unseeded yard wastes, seeded food wastes and unseeded food wastes produced approximately 6.5, 6.1, 2.1, 0.83, 2.5 and 0.33 mg of 13 volatile and semi-volatile aromatic organic compounds combined, respectively, per dry kg. All VOCs were emitted early during the composting process and their production rates decreased with time at thermophilic temperatures. PMID:15026225

Komilis, Dimitris P; Ham, Robert K; Park, Jae K

2004-04-01

269

Implementation and evaluation of a comprehensive emission model for Europe  

NASA Astrophysics Data System (ADS)

Crucial input data sets for Chemical Transport Models (CTM) are the meteorological fields and the emissions data. While there are several publicly available meteorological models, the situation for European emission models is still different. European emissions data either lack spatial and temporal resolution, only cover specific countries or are proprietary and not free to use. In this work the US EPA emission model SMOKE (Sparse Matrix Operator Kernel Emissions) has been successfully adapted and partially extended to create European emissions input for CTMs. The modified version of the SMOKE emission model (SMOKE/E) uses official and publicly available data sets and statistics to create emissions of CO, NOx, SO2, NH3, PM2.5, PM10, NMVOC. Currently it supports VOC splits for several photochemical mechanisms, namely CB4, CB5 and RADM2. PM2.5 is split into elemental carbon, organic carbon, sulfate, nitrate and other particles. Additionally emissions of benzo[a]pyrene (BaP) have been modelled with SMOKE Europe. The temporal resolution of the emissions is one hour, the horizontal resolution is up to 1x1 km². SMOKE/E also implements plume in grid calculations for vertical distribution of point sources. The vertical resolution is infinitely variable and is implemented in the form of pressure levels. The area covered by the emission model at this point is Europe and it's surrounding countries, including north Africa and parts of Asia. Thus far SMOKE Europe has been used to create European emissions on a 54x54km² grid covering the whole of Europe and a 18x18km² nested grid over the North and Baltic Sea for the years 1990-2006. The currently implemented datasets allow for the calculation of emissions between 1970-2010. Besides this future emissions scenarios for the timespan 2010-2020 are being calculated using the EMEP projections. The created emissions have been statistically compared to the gridded EMEP emissions as well as to data from other emission models for the base years 2000 and 2001. The 54x54km² emissions data for 2000 were used as input for the CMAQ4.6 CTM and the calculated air concentrations were compared to EMEP measurements in Europe. Statistical comparison of Ozone and three particulate species (NH4,NO3,SO4) showed that SMOKE/E performs very good under the tested circumstances. O3 : (NMB 0.71) (SD 0.68) (F2 0.83) (CORR 0.55) using 48 Stations (hourly) NH4: (NMB 0.25) (SD 1.01) (F2 0.55) (CORR 0.53) using 8 Stations (daily) NO3: (NMB 0.42) (SD 0.60) (F2 0.40) (CORR 0.45) using 7 Stations (daily) SO4: (NMB 0.34) (SD 0.84) (F2 0.65) (CORR 0.55) using 21 Stations (daily) Abbreviations: Normalized Mean Bias (NMB), Standard Deviation (SD), Factor of 2 (F2), Correlation (CORR). The calculated air concentrations were compared with CMAQ runs using two purchased emissions datasets. It could be shown that the modified SMOKE model produces results comparable to those of commonly used European emissions data sets. For the future it is planed to implement emissions of heavy metals and polyfluorinated compounds into the SMOKE Europe model.

Bieser, Johannes; Aulinger, Armin; Matthias, Volker; Quante, Markus

2010-05-01

270

Fiber optic spectrochemical emission sensor: Detection of volatile chlorinated compounds in air and water using ultra-thin membranes  

SciTech Connect

Prior work on the fiber optic spectrochemical emission sensor called HaloSnif{trademark} has been extended to include an ultra-thin membrane which allows passage of volatile organic chlorinated compounds (VOCl). The membrane has been demonstrated to exclude H{sub 2}O during VOCl monitoring. The system is capable of measuring VOCl in gas-phase samples or aqueous solutions over a wide linear dynamic range. The lower limit of detection for trichloroethylene (TCE), perchloroethylene (PCE), carbon tetrachloride (CCl{sub 4}), and other related compounds in the gas-phase is 1 to 5 ppm{sub v/v}, and in the aqueous-phase is 5 to 10 mg/L. Waste site characterization and remediation activities often require chemical analysis in the vadose zone and in groundwater. These analyses are typically performed in analytical laboratories using widely accepted standardized methods such as gas chromatography, gas chromatography/mass spectrometry. The new developments with HaloSnif provide rapid field screening which can augment the standardized methods.

Anheier, N.C. Jr.; Olsen, K.B.; Osantowski, R.E.; Evans, J.C. Jr.; Griffin, J.W.

1993-05-01

271

Cancer risks from soil emissions of volatile organic compounds at the Lawrence Livermore National Laboratory  

SciTech Connect

The emission isolation flux chamber (EIFC) methodology was applied to Superfund investigations at the Lawrence Livermore National Laboratory Site 300 to determine if on-site workers were exposed to VOCs volatilizing from the subsurface and what, if any, health risks could be attributed to the inhalation of the VOCs volatilizing from the subsurface. During July and August of 1996, twenty, eighteen, and twenty six VOC soil vapor flux samples were collected in the Building 830, 832, and 854 areas, respectively using EIFCS. The VOC concentrations in the vapor samples were used to calculate soil flux rates which were used as input into an air dispersion model to calculate ambient air exposure-point concentrations. The exposure-point concentrations were compared to EPA Region IX Preliminary Remediation Goals (PRGs). Buildings 830 and 832 exposure-point concentrations were less then the PRGs therefore no cancer risks were calculated. The cancer risks for Building 854 ranged from 1.6 x 10{sup -7} to 2.1 x 10{sup -6}. The resultant inhalation cancer risks were all within the acceptable range, implying that on-site workers were not exposed to VOC vapors volatilizing from the subsurface soil that could have significant cancer risks. Therefore remediation in these areas would not be necessary.

Dibley, V. R., LLNL

1998-02-01

272

Theory of the 4 d ? 2 p and 4 f ? 4 d X-ray emission spectroscopies in rare-earth compounds  

Microsoft Academic Search

The 4d ? 2p X-ray emission spectra (XES) of rare-earth compounds are calculated with an impurity Anderson model with the full multiplet couplings, following the formula of a coherent second order optical process. Recent experiments are well reproduced with this model by using a constant value for the 4d core hole lifetime damping ?(4d) in light rare-earth compounds. On the

Satoshi Tanaka; Haruhiko Ogasawara; Kozo Okada; Akio Kotani

1996-01-01

273

Measurements of Volatile Organic Compounds (VOCs) from Biomass Combustion - Emission Ratios, OH Reactivities and SOA Precursors  

NASA Astrophysics Data System (ADS)

Multiple instruments including a gas chromatograph/mass spectrometer (GC/MS), a proton transfer reaction mass spectrometer (PTR-MS), a proton ion trap mass spectrometer (PIT-MS), a negative-ion proton-transfer chemical-ionization mass spectrometer (NI-PT-CIMS) and a Fourier-transform infrared spectrometer (FTIR) acquired data from 77 burns of various biomass fuels conducted at the U.S. Department of Agriculture (USDA) Forest Sciences Laboratory (FSL) in Missoula, MT in February 2009. We compare VOC measurements of oxygenates, aromatics and biogenics from the various instruments as well as from the various fuel types collected in southeastern and southwestern regions of the United States. The relative contribution of the combustion species to the total reactivity with the OH radical is calculated and compared to ambient air reactivity in various locations. Total reactivity for measured species in these fires occasionally exceeded 1000 sec-1 with the majority of this reactivity due to alkenes. In addition, we investigate the relative contribution of the combustion species to the potential for secondary organic aerosol (SOA) formation. Measurements of several compounds not previously reported in various urban ambient air measurement campaigns such as pyrazole (C3H4N2), pyrrole (C4H5N), benzofuran (C8H6O) and 2-furanaldehyde (C5H4O2), which are highly reactive with OH, will be presented.

Kuster, W. C.; Gilman, J. B.; Goldan, P. D.; Warneke, C.; Degouw, J.; Veres, P. R.; Burling, I. R.; Yokelson, R. J.

2009-12-01

274

Automobile commuter exposures to volatile organic compounds: Emissions, malfunctions, and policy  

SciTech Connect

The general population is exposed to the Volatile Organic Compounds (VOCs) n-hexane, 3-methylpentane, benzene, toluene, isooctane, xylenes, ethylbenzene, and 1,2,4-trimethylbenzene, and to carbon monoxide (CO), and formaldehyde in many microenvironments, including the passenger compartments of automobiles. This study determined the in-vehicle exposures to the above gasoline derived VOCs, carbon monoxide, and formaldehyde for automobile commuters during a suburban New Jersey and a New Jersey/New York commute. Measurements of VOC concentrations were determined within the passenger compartment of idling automobiles and along two commuting routes. Little difference in concentrations was seen between the two different interior ventilation extremes (windows open and vents on, windows closed and vents off) for properly functioning vehicles. However, exposures to all VOCs increased substantially when malfunctions occurred with the carburetor, electric choke, and fuel distribution system of one of the vehicles. These increases were largest when the vehicle`s windows were closed and ventilation system was off. Exposures to VOCs were lowest in the suburban commute, slightly higher on the New Jersey Turnpike, and highest in transit through the Lincoln Tunnel. The national daily average in-vehicle duration (93.2 minutes, or 6.5% of the day) and median in-vehicle benzene concentrations on the suburban and urban loops accounted for 9.3% and 10.3% of the total daily benzene exposures, respectively. Exposures nearly tripled for in-vehicle concentrations in the 90th percentile. Excess cancer risks from benzene exposure exceeded 1/10{sup 5} for benzene exposures above the 90th percentile. Lifetime cancer risks for formaldehyde exposures were below 1/10{sup 6}. Maximum n-hexane exposures were below the critical dose value for adverse effects to the central nervous system.

Lawryk, N.J.

1994-12-31

275

An experimental and theoretical study of the effects of environmental conditions and nonlinear adsorption on the emission rates of volatile organic compounds from contaminated soils  

SciTech Connect

Laboratory experiments were conducted to evaluate effects of soil moisture content, soil temperature, and air relative humidity on volatile organic compound (VOC) emission rates. Emission rates were substantially affected by changes in these variables representative of expected changes in the environment. Emission rates increased in response to increasing soil moisture content, soil temperature, air relative humidity, and in response to decreasing soil particle surface area. Adsorption isotherms of benzene and dichloromethane (DCM) were measured in the presence of 25 to 33% relative humidities in two soils in a static sorption chamber using an electrobalance. The isotherms were nonlinear and agreed with the BET model. Additional laboratory experiments were conducted to evaluate the effects of nonlinear adsorption of VOC on the emission rates from soils. The apparent diffusivities, D{sub app} of benzene in a low and a high surface area soil were measured at 25C. Mathematical models of VOC diffusion in soil, which were derived assuming equilibrium BET adsorption, agreed well with laboratory data. The effects of diurnal soil temperature fluctuations were modeled. Long-term enhancement of emissions occurred and instantaneous emission rates deviated substantially from an isothermal model. Another model was used to evaluate the effects of nonlinear adsorption on VOC emission rates. With increased VOC contamination levels in the soil, enhanced emission rates were predicted in accordance with laboratory experiments. An inverse model for remote sensing of VOC emission rates in the field was developed and successfully evaluated.

Shonnard, D.R.

1991-01-01

276

Emission Rates of Volatile Organic Compounds Released from Newly Produced Household Furniture Products Using a Large-Scale Chamber Testing Method  

PubMed Central

The emission rates of volatile organic compounds (VOCs) were measured to investigate the emission characteristics of five types of common furniture products using a 5?m3 size chamber at 25°C and 50% humidity. The results indicated that toluene and ?-pinene are the most dominant components. The emission rates of individual components decreased constantly through time, approaching the equilibrium emission level. The relative ordering of their emission rates, if assessed in terms of total VOC (TVOC), can be arranged as follows: dining table > sofa > desk chair > bedside table > cabinet. If the emission rates of VOCs are examined between different chemical groups, they can also be arranged in the following order: aromatic (AR) > terpenes (TER) > carbonyl (CBN) > others > paraffin (PR) > olefin (HOL) > halogenated paraffin (HPR). In addition, if emission strengths are compared between coated and uncoated furniture, there is no significant difference in terms of emission magnitude. Our results indicate that the emission characteristics of VOC are greatly distinguished between different furniture products in terms of relative dominance between different chemicals.

Ho, Duy Xuan; Kim, Ki-Hyun; Ryeul Sohn, Jong; Hee Oh, Youn; Ahn, Ji-Won

2011-01-01

277

Few long-term effects of simulated climate change on volatile organic compound emissions and leaf chemistry of three subarctic dwarf shrubs  

Microsoft Academic Search

Climate change is exposing arctic ecosystems to higher temperature, increased nutrient availability and shading due to the increasing cloud cover and the expanding forests. In this work, we assessed how these factors affect the emissions of biogenic volatile organic compounds (BVOCs) from three subarctic dwarf shrub species in a field experiment after 18 treatment years. Of the studied species the

Riikka Rinnan; A. Rinnan; Patrick Faubert; Päivi Tiiva; Jarmo K. Holopainen; Anders Michelsen

2011-01-01

278

Potential odorous volatile organic compound emissions from feces and urine from cattle fed corn-based diets with wet distillers grains and solubles  

Technology Transfer Automated Retrieval System (TEKTRAN)

Odor and volatile organic compound (VOC) emissions are a concern at animal feeding operations (AFOs). The issue has become more prevalent as human residences move into areas once occupied only by agriculture. Odors near AFOs are generally caused by odorous VOCs emitted from manure, the mixture of ...

279

Emission of alcohols and carbonyl compounds from a spark ignition engine. Influence of fuel and air/fuel equivalence ratio.  

PubMed

A spark ignition engine was used to study the impact of fuel composition and of the air/fuel equivalence (lambda) ratio on exhaust emissions of alcohols and aldehydes/ketones. Fuel blends contained eight hydrocarbons (n-hexane, 1-hexene, cyclohexane, n-octane, isooctane, toluene, o-xylene, and ethylbenzene (ETB)) and four oxygenated compounds (methanol, ethanol, 2-propanol, and methyl tert butyl ether (MTBE)). Exhaust methanol is principally produced from fuel methanol and MTBE but also from ethanol, 2-propanol, isooctane, and hexane. Exhaust ethanol and 2-propanol are produced only from the respective fuel compounds. Exhaust formaldehyde is mainly produced from fuel methanol, acetaldehyde from fuel ethanol, and propionaldehyde from straight-chain hydrocarbons. Exhaust acroleine comes from fuel 1-hexene, acetone from 2-propanol, n-hexane, n-octane, isooctane, and MTBE. Exhaust crotonaldehyde comes from fuel 1-hexene, cyclohexane, n-hexane, and n-octane, methacroleine from fuel isooctane, and benzaldehyde from fuel aromatics. Light pollutants (C1-C2) are most likely formed from intermediate species which are quite independent of the fuel composition. An increase in A increases the exhaust concentration of acroleine, crotonaldehyde, methacroleine, and decreases these of the three alcohols for the alcohol-blended fuels. The concentration of methanol, formaldehyde, propionaldehyde, and benzaldehyde is a maximum atstoichiometry. The exhaust concentration of acetaldehyde and acetone presents a complex behavior: it increases in some cases, decreases in others, or presents a maximum at stoichiometry. The concentration of four aldehydes (formaldehyde, acetaldehyde, propionaldehyde, and benzaldehyde) is also linked with the exhaust temperature and fuel H/C ratio. PMID:12075798

Zervas, E; Montagne, X; Lahaye, J

2002-06-01

280

Emissions of organo-metal compounds via the leachate and gas pathway from two differently pre-treated municipal waste materials - A landfill reactor study  

SciTech Connect

Due to their broad industrial production and use as PVC-stabilisers, agro-chemicals and anti-fouling agents, organo-metal compounds are widely distributed throughout the terrestrial and marine biogeosphere. Here, we focused on the emission dynamics of various organo-metal compounds (e.g., di,- tri-, tetra-methyl tin, di-methyl mercury, tetra-methyl lead) from two different kinds of pre-treated mass waste, namely mechanically-biologically pre-treated municipal solid waste (MBP MSW) and municipal waste incineration ash (MWIA). In landfill simulation reactors, the emission of the organo-metal compounds via the leachate and gas pathway was observed over a period of 5 months simulating different environmental conditions (anaerobic with underlying soil layer/aerated/anaerobic). Both waste materials differ significantly in their initial amounts of organo-metal compounds and their environmental behaviour with regard to the accumulation and depletion rates within the solid material during incubation. For tri-methyl tin, the highest release rates in leachates were found in the incineration ash treatments, where anaerobic conditions in combination with underlying soil material significantly promoted its formation. Concerning the gas pathway, anaerobic conditions considerably favour the emission of organo-metal compounds (tetra-methyl tin, di-methyl mercury, tetra-methyl lead) in both the MBP material and especially in the incineration ash.

Michalzik, B. [Institute of Geography, Georg-August University Goettingen, Unit of Landscape Ecology, Goldschmidtstrasse 5, 37073 Goettingen (Germany)], E-mail: bmichal@gwdg.de; Ilgen, G.; Hertel, F. [Bayreuth Institute of Terrestrial Ecosystem Research (BITOEK/BayCEER), Central Laboratory Unit, University of Bayreuth, Dr. Hans- Frisch-Strasse 1-3, 95448 Bayreuth (Germany); Hantsch, S.; Bilitewski, B. [Institute for Waste Management and Contaminated Site Treatment, Dresden University of Technology, Pratzschwitzer Strasse 15, 01796 Pirna (Germany)

2007-07-01

281

Volatile organic compounds (VOCs) emission characteristics and control strategies for a petrochemical industrial area in middle Taiwan  

Microsoft Academic Search

This study investigated VOC emissions from the largest petrochemical industrial district in Taiwan and recommended some control measures to reduce VOC emissions. In addition to the petrochemical industry, the district encompasses a chemical and fiber industry, a plastics industry and a harbor, which together produce more than 95% of the VOC emissions in the area. The sequence of VOC emission

Chia-Hsien Yen; Jao-Jia Horng

2009-01-01

282

Modeling the influence of biogenic volatile organic compound emissions on ozone concentration during summer season in the Kinki region of Japan  

NASA Astrophysics Data System (ADS)

Tropospheric ozone adversely affects human health and vegetation, and biogenic volatile organic compound (BVOC) emission has potential to influence ozone concentration in summer season. In this research, the standard emissions of isoprene and monoterpene from the vegetation of the Kinki region of Japan, estimated from growth chamber experiments, were converted into hourly emissions for July 2002 using the temperature and light intensity data obtained from results of MM5 meteorological model. To investigate the effect of BVOC emissions on ozone production, two ozone simulations for one-month period of July 2002 were carried out. In one simulation, hourly BVOC emissions were included (BIO), while in the other one, BVOC emissions were not considered (NOBIO). The quantitative analyses of the ozone results clearly indicate that the use of spatio-temporally varying BVOC emission improves the prediction of ozone concentration. The hourly differences of monthly-averaged ozone concentrations between BIO and NOBIO had the maximum value of 6 ppb at 1400 JST. The explicit difference appeared in urban area, though the place where the maximum difference occurred changed with time. Overall, BVOC emissions from the forest vegetation strongly affected the ozone generation in the urban area.

Bao, Hai; Shrestha, Kundan Lal; Kondo, Akira; Kaga, Akikazu; Inoue, Yoshio

2010-01-01

283

Emission of organic compounds from mould and core binders used for casting iron, aluminium and bronze in sand moulds.  

PubMed

Emissions from mould and core sand binders commonly used in the foundry industry have been investigated. Degradation of three different types of binders was investigated: Furfuryl alcohol (FA), phenolic urethane (PU) and resol-CO2 (RC). In each group of binders, at least two different binder compositions were tested. A test method that provides uniform test conditions is described. The method can be used as a general test method to analyse off gases from binders. Moulds, containing a standard size casting, were produced and the amount and type of organic compounds, resulting from thermal degradation of binders, was monitored when cast iron, bronze and aluminium was poured in the moulds. Binder degradation was measured by collecting off gases in a specially designed ventilation hood at a constant flow rate. Samples were taken from the ventilation system and analysed for hydrocarbons and CO content. It is shown how off-gases vary with time after pouring and shake out. Also the composition of off-gases is analysed and shown. It is further shown how the composition of off-gasses varies between different types of binders and with varying composition of the binders as well as function of the thermal load on the moulding sand. PMID:20954042

Tiedje, Niels; Crepaz, Rudolf; Eggert, Torben; Bey, Niki

2010-12-01

284

Area sources of VOC (volatile organic compounds) emissions and their contribution to tropospheric ozone concentrations. Report for July 1988-March 1989  

SciTech Connect

The paper quantifies the importance of area sources to total volatile organic compound (VOC) emissions, reviews components of EPA/AEERL's non-attainment program, discusses the status of emission control or prevention for several area sources, and reviews some of the regulatory strategies being implemented or considered by state and local air pollution agencies. In 1988, several projects were undertaken by AEERL to develop a greater understanding of the contribution to the ozone problem by area sources of VOCs. These include studies related to specific sources of VOCs, identification of consumer/commercial product control options, and determination of the regional/seasonal variations in emissions. In each study, available sources of information have been used to develop priorities for the sources of emissions contributing to the ozone non-attainment problem. Sources of data include the technical literature, contacts in industry and elsewhere in the EPA, and surveys conducted by various trade organizations.

Not Available

1989-01-01

285

New insights into halocarbon emissions in boreal regions: Forest fires and Alberta oil sands  

NASA Astrophysics Data System (ADS)

Boreal forest fires and Alberta oil sands represent two major co-located trace gas emission sources within the boreal ecosystem. During the airborne ARCTAS mission in summer 2008, UC-Irvine performed the most comprehensive characterization of halocarbon emissions from boreal forest fires to date. In summer 2008 and 2010 we also performed the first independent characterizations of halocarbon emissions from Alberta's oil sands industry. In both cases the measurements were made using whole air sampling followed by gas chromatography analysis using electron capture detection and mass spectrometer detection. In the case of boreal forest fires, of 26 speciated halocarbons that were measured, only the simplest halocarbons were emitted from the fires (CH3Cl, CH3Br, CH3I, 1,2-C2H4Cl2, C2H5Cl and CH2Br2) (Simpson et al., 2011). These compounds were released in relatively small quantities and together they represented <0.3% of the total carbon released from boreal forest fires in the form of non-methane volatile organic compounds (NMVOCs). Even though CH3Cl was the most abundantly emitted halocarbon, its average global emission from boreal forest fires (0.011 ± 0.003 Tg yr-1) was very small compared to its global source budget. The poly-chlorinated compounds CH2Cl2, CHCl3 and CH3CCl3 were not released from the fires. In the case of the Alberta oil sands, based on airborne measurements during the ARCTAS mission, 15 of 26 measured halocarbons were statistically enhanced over the oil sands compared to local background values (Simpson et al., 2010). The short-lived solvents C2HCl3, C2Cl4, C2H5Cl and CHCl3 were the most strongly enhanced halocarbons, with maximum values that were 1.5-34× the local background. A subsequent ground-based study in 2010 detected even stronger halocarbon enhancements downwind of upgraders and tailings sand at the oil sands surface mining sites. For example C2HCl3 and CHBrCl2 mixing ratios were up to 60-85× the local background values. Long-lived halocarbons such as HFC-152a, HFC-134a, HCFC-142b and HCFC-22 were also elevated downwind of the mining and upgrading operations. Together these results suggest that boreal forest fires are a relatively minor halocarbon source, and that halocarbon emissions from the Alberta oil sands industry require further investigation.

Simpson, I. J.; Barletta, B.; Meinardi, S.; Marrero, J.; Rowland, F. S.; Akagi, S. K.; Yokelson, R. J.; Blake, D. R.

2011-12-01

286

Experimental investigation on regulated and unregulated emissions of a diesel/methanol compound combustion engine with and without diesel oxidation catalyst.  

PubMed

The use of methanol in combination with diesel fuel is an effective measure to reduce particulate matter (PM) and nitrogen oxides (NOx) emissions from in-use diesel vehicles. In this study, a diesel/methanol compound combustion (DMCC) scheme was proposed and a 4-cylinder naturally-aspirated direct-injection diesel engine modified to operate on the proposed combustion scheme. The effect of DMCC and diesel oxidation catalyst (DOC) on the regulated emissions of total hydrocarbons (THC), carbon monoxide (CO), NOx and PM was investigated based on the Japanese 13 Mode test cycle. Certain unregulated emissions, including methane, ethyne, ethene, 1,3-butadiene, BTX (benzene, toluene, xylene), unburned methanol and formaldehyde were also evaluated based on the same test cycle. In addition, the soluble organic fraction (SOF) in the particulate and the particulate number concentration and size distribution were investigated at certain selected modes of operation. The results show that the DMCC scheme can effectively reduce NOx, particulate mass and number concentrations, ethyne, ethene and 1,3-butadiene emissions but significantly increase the emissions of THC, CO, NO(2), BTX, unburned methanol, formaldehyde, and the proportion of SOF in the particles. After the DOC, the emission of THC, CO, NO(2), as well as the unregulated gaseous emissions, can be significantly reduced when the exhaust gas temperature is sufficiently high while the particulate mass concentration is further reduced due to oxidation of the SOF. PMID:19919875

Zhang, Z H; Cheung, C S; Chan, T L; Yao, C D

2010-01-15

287

Using IASI and MIPAS in combination to characterise CO and other volatile organic compound emissions from fires  

NASA Astrophysics Data System (ADS)

Short-lived species emitted from wildfires, such as carbon monoxide (CO) and volatile organic compounds (VOCs), carry a lot of information on atmospheric processes relating to chemistry, convection and emission. These disruptive events are indirectly a climatological feature of the Earth's atmosphere and its climate response and occur at sufficient frequency to make studying and understanding biomass plume chemistry vital. Accurate measurement of trace gases from these events will also aid improvements in climate/chemistry models. In this study, we utilise IASI, MIPAS and ACE data to derive wildfire emissions of VOCs, in the context of two periods; the early 2009 Black Saturday fires and the BORTAS campaign fires. Using the complementary viewing angles of IASI (nadir) and MIPAS/ACE (limb), results will be shown which illustrate observations of aged plume composition, chemistry, distribution and area along with information about vertical distribution. The Black Saturday fires were a particularly severe event over South-Eastern Australia which burnt an area of 450,000 km2, with up to 400 individual fires being identified on February 7th 2009 alone. Driven by weeks of little or no rainfall and record-breaking temperatures, we show that the plumes from this event, contained enhanced VOC amounts and mixed within the lower stratosphere, reaching altitudes up to 18 km. Enhancement ratios, using CO as a reference, show potential secondary formation of HCOOH within the plume. We are able to track the evolution of the plume with IASI data for up to 20 days after the initial event. The second case study is comparison to results from a recent aircraft campaign over North America in July/August 2011 (BORTAS). The NERC-funded campaign was dedicated to studying the impact of local pollution events over North America and aged plumes originated from Asia and Siberia. In the context of the campaign aims, we investigated CO, VOC chemistry and aerosol signatures in boreal biomass plumes. The most significant event was a series of fires over North-west Ontario which we show released a significant quantity of CO and formic acid. The validation of IASI formic acid from this event with in-situ data is particularly good. We also derive the time-evolution of a variety of VOCs (including PAN) within aged plumes, using comparisons of MIPAS and ACE data. These plumes originate from both the boreal forests of North America and Siberia, and show excellent agreement between these independent datasets. Particularly large enhancements of PAN were discovered from Siberian forest fires in late July 2011.

Moore, David; Sembhi, Harjinder; Remedios, John; Tereszchuk, Keith

2013-04-01

288

Impact of rising CO 2 on emissions of volatile organic compounds: isoprene emission from Phragmites australis growing at elevated CO 2 in a natural carbon dioxide spring  

Microsoft Academic Search

Isoprene basal emission (the emission of isoprene from leaves exposed to a light intensity of 1000 m m m m mol m - - - - 2 s - - - - 1 and maintained at a temperature of 30 ? ? ? ? C) was measured in Phragmites australis plants growing under elevated CO 2 in the Bossoleto CO

P. A. SCHOLEFIELD; K. J. DOICK; B. M. J. HERBERT; P. PINELLI

289

The impact of China's vehicle emissions on regional air quality in 2000 and 2020: a scenario analysis  

NASA Astrophysics Data System (ADS)

The number of vehicles in China has been increasing rapidly. We evaluate the impact of current and possible future vehicle emissions from China on Asian air quality. We modify the Regional Emission Inventory in Asia (REAS) for China's road transport sector in 2000 using updated Chinese data for vehicle numbers, annual mileage and emission factors. We develop two scenarios for 2020: a scenario where emission factors remain the same as they were before any regulation was implemented (business-as-usual, BAU), and a scenario where Euro 3 vehicle emission standards are applied to all vehicles (except motorcycles and rural vehicles). The Euro 3 scenario is an approximation of what may be the case in 2020 as, starting in 2008, all new gasoline and diesel vehicles in China (except motorcycles) were required to meet the Euro 3 emission standards. Using the Weather Research and Forecasting model coupled with Chemistry (WRF/Chem), we examine the regional air quality response to China's vehicle emissions in 2000 and in 2020 for the BAU and Euro 3 scenarios. We evaluate the 2000 model results with observations in Japan, China, Korea, and Russia. Under BAU in 2020, emissions of carbon monoxide (CO), nitrogen oxides (NOx), non-methane volatile organic compounds (NMVOCs), black carbon (BC) and organic carbon (OC) from China's vehicles more than double compared to the 2000 baseline. If all vehicles meet the Euro 3 regulations in 2020, however, these emissions are reduced by more than 50% relative to BAU. The implementation of stringent vehicle emission standards leads to a large, simultaneous reduction of the surface ozone (O3) mixing ratios and particulate matter (PM2.5) concentrations. In the Euro 3 scenario, surface O3 is reduced by more than 10 ppbv and surface PM2.5 is reduced by more than 10 ?g m-3 relative to BAU in Northeast China in all seasons. In spring, surface O3 mixing ratios and PM2.5 concentrations in neighboring countries are also reduced by more than 3 ppbv and 1 ?g m-3, respectively. We find that effective regulation of China's road transport sector will be of significant benefit for air quality both within China and across East Asia as well.

Saikawa, E.; Kurokawa, J.; Takigawa, M.; Mauzerall, D. L.; Horowitz, L. W.; Ohara, T.

2011-04-01

290

Experimental investigation on regulated and unregulated emissions of a diesel\\/methanol compound combustion engine with and without diesel oxidation catalyst  

Microsoft Academic Search

The use of methanol in combination with diesel fuel is an effective measure to reduce particulate matter (PM) and nitrogen oxides (NOx) emissions from in-use diesel vehicles. In this study, a diesel\\/methanol compound combustion (DMCC) scheme was proposed and a 4-cylinder naturally-aspirated direct-injection diesel engine modified to operate on the proposed combustion scheme. The effect of DMCC and diesel oxidation

Z. H. Zhang; C. S. Cheung; T. L. Chan; C. D. Yao

2010-01-01

291

Mapping and Profile of Emission Sources for Airborne Volatile Organic Compounds from Process Regions at a Petrochemical Plant in Kaohsiung, Taiwan  

Microsoft Academic Search

This work surveyed five process regions inside a petro-chemical plant in Taiwan to characterize the profiles of airborne volatile organic compounds (VOCs) and locate emission sources. Samples, taken with canisters, were analyzed with gas chromatography-mass spectrometry according to the TO-14 method. Each region was deployed with 24 sampling sites, sampled twice, and 240 samples in total were measured during the

Ching-Liang Chen; Hung-Yuan Fang; Chi-Min Shu

2006-01-01

292

Monitoring of volatile compound emissions during dry anaerobic digestion of the Organic Fraction of Municipal Solid Waste by Proton Transfer Reaction Time-of-Flight Mass Spectrometry.  

PubMed

Volatile Organic Compounds (VOCs) formed during anaerobic digestion of aerobically pre-treated Organic Fraction of Municipal Solid Waste (OFMSW), have been monitored over a 30 day period by a direct injection mass spectrometric technique: Proton Transfer Reaction Time-of-Flight Mass Spectrometry (PTR-ToF-MS). Most of the tentatively identified compounds exhibited a double-peaked emission pattern which is probably the combined result from the volatilization or oxidation of the biomass-inherited organic compounds and the microbial degradation of organic substrates. Of the sulfur compounds, hydrogen sulfide had the highest accumulative production. Alkylthiols were the predominant sulfur organic compounds, reaching their maximum levels during the last stage of the process. H(2)S formation seems to be influenced by the metabolic reactions that the sulfur organic compounds undergo, such as a methanogenesis induced mechanism i.e. an amino acid degradation/sulfate reduction. Comparison of different batches indicates that PTR-ToF-MS is a suitable tool providing information for rapid in situ bioprocess monitoring. PMID:23079412

Papurello, Davide; Soukoulis, Christos; Schuhfried, Erna; Cappellin, Luca; Gasperi, Flavia; Silvestri, Silvia; Santarelli, Massimo; Biasioli, Franco

2012-09-24

293

Estimation of vehicular emission inventories in China from 1980 to 2005  

NASA Astrophysics Data System (ADS)

Multi-year inventories of vehicular emissions at a high spatial resolution of 40 km×40 km were established in China using the GIS methodology for the period 1980-2005, based on provincial statistical data from yearbooks regarding vehicles and roads, and on the emission factors for each vehicle category in each province calculated by COPERT III program. Results showed that the emissions of CH 4, CO, CO 2, NMVOC, NO x, PM 10, and SO 2 increased from 5, 1066, 19 893, 169, 174, 26, and 16 thousand tons in 1980 to 377, 36 197, 674 629, 5911, 4539, 983, and 484 thousand tons in 2005 at an annual average rate of 19%, 15%, 15%, 15%, 14%, 16%, and 15%, respectively. Statistical analysis of vehicular emissions and GDP showed that they were well positively correlated, which revealed that increase of pollutant emissions has been accompanying the growth of GDP. Spatial distribution of pollutant emissions was rather unbalanced: over three-quarters of the total emissions concentrated in developed regions of China's southeastern, northern and central areas covering only 35.2% of China's territory, while the remaining emissions were distributed over the southwestern, northwestern and northeastern regions covering as much as 64.8% of the territory. In 2005, the Beijing-Tianjin-Hebei region, the Yangtze River Delta, and the Pearl River Delta covering only 2.3%, 2.2%, and 1.9%, respectively, of the territory, generated about 10%, 19%, and 12%, respectively, of the total emissions. Since 1990, motorcycles have been the major contributors to the CH 4, CO, NMVOC, and PM 10 emissions, due to the large population. Heavy-duty vans were the major contributors to the NO x and SO 2 emissions because of high emission factors. Passenger cars contributed about one third of the emissions of each pollutant. Contributions of vehicle categories to emissions varied from province to province, due to the diversity of vehicle compositions among provinces.

Cai, Hao; Xie, Shaodong

294

GAS-PHASE MASS TRANSFER MODEL FOR PREDICTING VOLATILE ORGANIC COMPOUND (VOC) EMISSION RATES FROM INDOOR POLLUTANT SOURCES  

EPA Science Inventory

Analysis of the impact of sources on indoor pollutant concentrations and occupant exposure to indoor pollutants requires knowledge of the emission rates from the sources. Emission rates are often determined by chamber testing and the data from the chamber test are fitted to an em...

295

and Uncertainty in Stationary Natural Gas-fueled Internal Combustion Engine NOx and Total Organic Compounds Emission Factors  

Microsoft Academic Search

Quantitative methods for characterizing both variability and uncertainty are applied to case studies of emission factors for stationary natural gas-fueled internal combustion engines. NOx and Total Organic Carbon (TOC) emission data sets for lean burn engines were analyzed. Data were available for uncontrolled engines and for engines with pre-combustion chamber (PCC) and \\

H. Christopher Frey

296

Economic Impact of Revised Measurement Methods for Emissions of Sulfur Compounds, Proposed Regulations R87-31.  

National Technical Information Service (NTIS)

The study provides estimates of the economic impacts of proposed Illinois Pollution Control Board regulations governing measurement methods for sulfur dioxide emissions from coal-fired boilers in Illinois. The study also examines the methods used by facil...

F. T. DePaul J. Helm

1989-01-01

297

Organic liquids storage tanks volatile organic compounds (VOCS) emissions dispersion and risk assessment in developing countries: the case of Dar-es-Salaam City, Tanzania.  

PubMed

The emission estimation of nine volatile organic compounds (VOCs) from eight organic liquids storage tanks companies in Dar-es-Salaam City Tanzania has been done by using US EPA standard regulatory storage tanks emission model (TANKS 4.9b). Total VOCs atmospheric emission has been established to be 853.20 metric tones/yr. It has been established further that petrol storage tanks contribute about 87% of total VOCs emitted, while tanks for other refined products and crude oil were emitting 10% and 3% of VOCs respectively. Of the eight sources (companies), the highest emission value from a single source was 233,222.94 kg/yr and the lowest single source emission value was 6881.87 kg/yr. The total VOCs emissions estimated for each of the eight sources were found to be higher than the standard level of 40,000 kg/yr per source for minor source according to US EPA except for two sources, which were emitting VOCs below the standard level. The annual emissions per single source for each of the VOCs were found to be below the US EPA emissions standard which is 2,000 kg/yr in all companies except the emission of hexane from company F1 which was slightly higher than the standard. The type of tanks used seems to significantly influence the emission rate. Vertical fixed roof tanks (VFRT) emit a lot more than externally floating roof tanks (EFRT) and internally floating roof tanks (IFRT). The use of IFRT and EFRT should be encouraged especially for storage of petrol which had highest atmospheric emission contribution. Model predicted atmospheric emissions are less than annual losses measured by companies in all the eight sources. It is possible that there are other routes for losses beside atmospheric emissions. It is therefore important that waste reduction efforts in these companies are directed not only to reducing atmospheric emissions, but also prevention of the spillage and leakage of stored liquid and curbing of the frequently reported illegal siphoning of stored products. Emission rates for benzene, toluene, and xylene were used as input to CALPUFF air dispersion model for the calculation of spatial downwind concentrations from area sources. By using global positioning system (GPS) and geographical information system (GIS) the spatial benzene concentration contributed by organic liquid storage tanks has been mapped for Dar-es-Salaam City. Highest concentrations for all the three toxic pollutants were observed at Kigamboni area, possibly because the area is located at the wind prevailing direction from the locations of the storage tanks. The model predicted concentrations downwind from the sources were below tolerable concentrations by WHO and US-OSHA. The highest 24 hrs averaging time benzene concentration was used for risk assessment in order to determine maximum carcinogenic risk amongst the population exposed at downwind. Established risk for adult and children at 2.9x10(-3) and 1.9x10(-3) respectively, are higher than the acceptable US-EPA risk of 1x10(-6). It is very likely that the actual VOCs concentrations in some urban areas in Tanzania including Dar-es-Salaam City are much higher than the levels reported in this study when other sources such as petrol stations and motor vehicles on the roads are considered. Tanzania Government therefore need to put in place: an air quality policy and legislation, establish air quality guidelines and acquire facilities which will enable the implementation of air quality monitoring and management programmes. PMID:16779602

Jackson, Msafiri M

2006-05-01

298

BIOGENIC VOLATILE ORGANIC COMPOUND EMISSIONS (BVOCS) II. LANDSCAPE FLUX POTENTIALS FROM THREE CONTINENTAL SITES IN THE U.S.  

EPA Science Inventory

Landscape flux potentials for biogenic volatile organic compounds (BVOCs) were derived for three ecosystems in the continental U. S. (Fernbank Forest, Atlanta, GA; Willow Creek, Rhinelander, WI; Temple Ridge, CO). Analytical data from branch enclosure measurements reported in a ...

299

SEASONAL AND ANNUAL MODELING OF REDUCED NITROGEN COMPOUNDS OVER THE EASTERN UNITED STATES: EMISSIONS, AMBIENT LEVELS, AND DEPOSITION AMOUNTS  

EPA Science Inventory

Detailed description of the distributions and seasonal trends of atmospheric nitrogen compounds is of considerable interest given their role in formation of acidic substances, tropospheric ozone and particulate matter and nutrient loading effects resulting from their deposition t...

300

delta 13 C and deltaD of volatile organic compounds in an alumina industry stack emission  

Microsoft Academic Search

Compound specific isotope analysis (CSIA) is becoming more widely accepted as a tool for determining the sources of contaminants and monitoring their transport and fate in the environment. However, measuring deltaD of volatile organic compounds (VOCs) in atmospheric samples is still underexplored. The present study applies thermal desorption-gas chromatography-isotope ratio mass spectrometry (TD-GC-irMS) for the first time to measure stable

Christiane Vitzthum von Eckstaedt; Kliti Grice; Marisa Ioppolo-Armanios; Mark Jones

2011-01-01

301

Nitrogen saturation in the Rocky Mountains: Linking emissions, deposition, and ecosystem effects using stable isotopes of nitrogen compounds  

USGS Publications Warehouse

Elevated levels of atmospheric N deposition are affecting terrestrial and aquatic ecosystems at high elevations in Rocky Mountain National Park and adjacent areas of the Front Range of Colorado. Federal and state agencies are now working together to develop cost-effective means for reducing atmospheric N deposition. A discussion on N saturation covers the need for better understanding of N emission source areas and source types that contribute to N deposition in the Rocky Mountains Front Range of Colorado; reductions in NO emissions that resulted from Clean Air Act Amendments, which caused NO3 deposition to decrease between 1984 and 2003; factors contributing to N deposition, e.g., rapid population growth and energy development; origins of NO3, e.g., as NO emissions from fossil fuel combustion, including stationary sources (e.g. emission from coal combustion in electric generating units), and mobile sources (vehicle emissions); disperse stationary sources from energy resource development, e.g., natural gas production; and the importance of incorporating local source characterization and finer spatial and temporal sampling into future studies, which could provide additional insight into N deposition source attribution. This is an abstract of a paper presented at the 100th Annual Conference and Exhibition of the Air and Waste Management Association (Pittsburgh, PA 6/26-29/2007).

Campbell, D. H.; Nanus, L.; Bohlke, J. K.; Harlin, K.; Collett, J.

2007-01-01

302

Uncertainty assessment of potential biogenic volatile organic compound emissions from forests with the Monte Carlo method: Case study for an episode from 1 to 10 July 2000 in Poland  

Microsoft Academic Search

An uncertainty assessment of a volatile organic compounds (VOCs) emission inventory using a Monte Carlo study according to the “Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories” has been performed. For the episode of 1–10 July 2000 hourly biogenic VOC (BVOC) emissions from forests in Poland were calculated in 10 km × 10 km resolution with a

G. Smiatek; M. Bogacki

2005-01-01

303

Simultaneous determination of chlorinated organic compounds from environmental samples using gas chromatography coupled with a micro electron capture detector and micro-plasma atomic emission detector  

NASA Astrophysics Data System (ADS)

Water and sediment samples were screened simultaneously for the presence of polychlorinated organic compounds using gas chromatography (GC) coupled with an micro electron capture detector (?-ECD) and a newly developed helium plasma based on a micro-atomic emission detector (?-AED). The GC column effluent was split 15:85 between two detectors. In this way, two chromatograms, one obtained by ?-ECD and another by ?-AED, were recorded simultaneously. ?-, ?-hexachlorocyclohexane and p, p'-DDE were detected. RSDs of the monitoring results from the two detection methods were <20% for the three compounds. A detection limit of 8.5 pg and at least 3 orders of magnitude of linear range for ?-AED was observed.

Quan, Xie; Chen, Shuo; Platzer, Bernhard; Chen, Jingwen; Gfrerer, Marion

2002-01-01

304

Bioassay-directed chemical analysis of organic extracts of emissions from a laboratory-scale incinerator: Combustion of surrogate compounds  

SciTech Connect

A prototype/laboratory-scale rotary kiln (73 kW, 250,000 Btu/h) was used to examine the chemical composition and biological effects of the emissions produced when the kiln was operated under suboptimal conditions resulting from batch charging. The surrogate wastes evaluated were polyethylene (PE), polyvinylchloride (PVC), toluene (TOL), carbon tetrachloride (CC14), PE + PVC and TOL + CC14. The dichloromethane-extractable organics from particles (collected on filters) and semivolatiles (collected on XAD-2 resin) were evaluated for mutagenic activity using the Salmonella (Ames) mutagenicity assay in strain TA98 (+S9). The mutagenic potencies (revertants/microgram of extractable organics) of the emissions ranked as follows: PE > TOL > PE + PVC > TOL + CC14. The organic extracts from the PVC and CC14 emissions were not mutagenic.

DeMarini, D.M.; Williams, R.W.; Perry, E.; Lemieux, P.M.; Linak, W.P.

1992-01-01

305

Time Resolved Detection of Native Molecular Emissions and Recombination using Femtosecond Laser Induced Breakdown Spectroscopy from Organic Compounds  

NASA Astrophysics Data System (ADS)

Laser induced breakdown plasmas are ``dirty'' events yielding a mixture of ionized species, electrons, and non-ionized matter of various size. Molecular emissions have been detected in excited nanosecond plasmas microseconds after the ablation event. However, with these molecular signatures it is difficult to distinguish between native emissions and atmospheric recombination with respect to the sample probed. A time resolved study during and after the continuum of the plasma event produced from specific organic materials can yield a possible insight in identifying native molecular emission and recombination. In this study, a plasma was formed by interacting a femtosecond beam with Nitrobenzoic acid, Ammonium Nitrate, Benzylacetonitrile, Nitrophenol, and Phthalimide. Molecular spectral signatures of NO, OH+, CN, C2, and NH were monitored as a function of plasma lifetime, with a 50 nanosecond gate window, delineating a trend of growth and decay. Use of a buffer gas, Argon, has been observed suppressing the impact of atmospheric oxygen, nitrogen, and hydrogen on plasma assisted recombination.

Martinez, Jorge; Akpovo, Charlemagne; Bullock, Nathan; Allen, Susan; Johnson, Lewis

2011-06-01

306

Emission mechanism of doubly ortho-linked quinoxaline/diphenylfluorene or cis-stilbene/fluorene hybrid compounds based on the transient absorption and emission measurements during pulse radiolysis.  

PubMed

A series of bipolar OLED materials were subjected to pulsed radiolysis experiments to determine their transient absorption and lifetime profiles of the independently in situ generated radical cations and anions in solutions. Moreover, their emission behaviors from the charge recombination of their radical ions were also determined by the pulse radiolysis method. It was found the absorption bands in doubly ortho-linked quinoxaline/diphenylfluorene hybrids 1a-e are red-shifted progressively with increasing electron-donating nature at the C5 and C8 positions of the quinoxaline template. The incipient radical anions in 1a-e are mainly localized on the quinoxaline heterocyclic moiety, whereas the incipient radical cations are mainly distributed onto the attached electron-donating groups at the C5 and C8 positions of the quinoxaline template. For other doubly ortho-linked cis-stilbene derivatives 3d, 3f, and 4f, the radical anions are mainly localized on the cis-stilbene central moiety and the radical cation is mainly distributed onto both para substituents of the cis-stilbene templates. It was also shown that there is a correlation between their optoelectronic emission efficiencies and the radiolysis induced emission intensities. In addition, the charge transporting behaviors within an OLED device were found to show the relationship with transient absorption half-lives (tau(1/2)) of the radical ions. Charge recombination mechanisms in both the OLED and pulsed radiolysis experiments were proposed to rationalize these observations, allowing us to establish some guidelines for an ultimate molecular design of ideal bipolar optoelectronic materials with a judicious choice of local charge appendages in the optoelectronic templates. PMID:19385627

Wei, Yi; Samori, Shingo; Tojo, Sachiko; Fujitsuka, Mamoru; Lin, Jin-Sheng; Chen, Chien-Tien; Majima, Tetsuro

2009-05-20

307

Protocol for determining the daily volatile organic compound emission rate of automobile and light-duty truck topcoat operations  

SciTech Connect

The protocol determines the daily VOC emission rate (pounds of VOC per gallon of coating solids deposited) for a complete automobile and light-duty truck topcoat operation. The protocol is designed for use in cases where (1) the topcoat emission limit is stated in units of pounds of VOC per gallon of solids deposited, (2) compliance is to be demonstrated for each day, and (3) the entire topcoat operation (i.e., all spray booths, flash-off areas and bake ovens where topcoat is applied, dried, and cured; except final off-line repair) is treated as a single entity.

Salman, D.

1988-12-01

308

EMISSIONS FROM SLUDGE INCINERATORS WITH VENTURI AND TRAY SCRUBBERS AND WET ELECTROSTATIC PRECIPITATORS - METALS, CHROMIUM AND NICKEL COMPOUNDS, AND ORGANICS  

EPA Science Inventory

At Site 5 (continuing a numbering system initiated in a previous 4-site project) tests were only conducted for methods development purposes. At Site 6, emissions were measured at the inlet and outlet of the control device. At Site 7, an evaluation of CO and THC CEMSs was performe...

309

DIFFERENCES IN FEEDLOT SURFACE MOISTURE AND MANURE CONTENT CONTROL ODOR COMPOUND PRODUCTION, DUST POTENTIAL, GREENHOUSE GAS EMISSION, AND NUTRIENT CONTENT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Cattle feedlot surface moisture and manure content vary spatiotemporally and are likely to be important factors controlling odor, dust, greenhouse gas, and NH3 emissions. This study examined the effect of six moistures (10% to 60%) and three manure/soil mixes (5%, 25%, and 75% manure) on odor compo...

310

BIOASSAY-DIRECTED CHEMICAL ANALYSIS OF ORGANIC EXTRACTS OF EMISSIONS FROM A LABORATORY-SCALE INCINERATOR: COMBUSTION OF SURROGATE COMPOUNDS  

EPA Science Inventory

The paper describes using a prototype/pilot-scale rotary kiln (73 kill) to examine the chemical composition and biological effect's of emissions produced when operating the kiln under suboptimal conditions resulting from batch charging. he surrogate wastes evaluated included comb...

311

Spatial surrogates for the disaggregation of CORINAIR emission inventories  

NASA Astrophysics Data System (ADS)

CORINAIR atmospheric emission inventories are frequently used input data for air quality models with a domain situated in Europe. In CORINAIR emission inventories, sources are broken down over 11 major source categories. This paper presents spatial surrogates for the disaggregation of CORINAIR atmospheric emission inventories for input of air pollutants and particulate matter to grid or polygon based air quality model domains inside Europe. The basis for the disaggregation model was the CLC2000 land cover data to which statistical weights were added. Weights were population census data for residential emissions, employment statistics for agricultural and industrial area emissions, livestock statistics for ammonia emissions and annual aircraft movements for emissions realized by air transport. Additional road and off-road network information was used to disaggregate emissions realized by traffic. A comparison of top down produced emission estimates with spatially resolved national emission data for The Netherlands and the United Kingdom gave confidence in the present spatial surrogates as a tool for the top down production of atmospheric emission maps. Explained variance at a spatial resolution of 5 km was >70% for CO, NMVOC and NO x, >60% for PM10 and almost 50% for SO 2.

Maes, Joachim; Vliegen, Jo; Van de Vel, Karen; Janssen, Stijn; Deutsch, Felix; De Ridder, Koen; Mensink, Clemens

312

Henry's law constants for paint solvents and their implications on volatile organic compound emissions from automotive painting  

Microsoft Academic Search

This paper describes experimental results of equilibrium partitioning of several significant paint solvents and formaldehyde between air and water to quantify the potential for capturing and retaining the constituents in spraybooth scrubber water during automotive painting. The compounds studied are toluene, n-butanol, methyl ethyl ketone methyl propyl ketone, methyl isobutyl ketone, methyl amyl ketone, butyl cellosolve, butyl cellosolve acetate, butyl

B. R. Kim; E. M. Kalis; T. DeWulf; K. M. Andrews

2000-01-01

313

Laboratory scale evaluation of volatile organic compound emissions as indication of swine carcass degradation inside biosecure composting units  

Microsoft Academic Search

Biosecure livestock mortality composting systems have been used to dispose of diseased livestock mortalities. In those types of system, visual inspection of carcass degradation is not possible and monitoring VOCs (volatile organic compounds) released by carcasses is a new approach to assess progress of the composting process. In this study, field-scale livestock mortality composting systems were simulated and a laboratory

Neslihan Akdeniz; Jacek A. Koziel; Hee-Kwon Ahn; Thomas D. Glanville; Benjamin P. Crawford; D. Raj Raman

2010-01-01

314

CHARACTERIZATION OF LOW-VOC LATEX PAINTS: VOLATILE ORGANIC COMPOUND CONTENT, VOC AND ALDEHYDE EMISSIONS, AND PAINT PERFORMANCE  

EPA Science Inventory

The report gives results of laboratory tests to evaluate commercially available latex paints advertised as "low-odor," "low-VOC (volatile organic compound)," or "no-VOC." Measurements were performed to quantify the total content of VOCs in the paints...

315

Statistical analysis of anthropogenic non-methane VOC variability at a European background location (Jungfraujoch, Switzerland)  

NASA Astrophysics Data System (ADS)

In-situ measurements of 7 volatile hydrocarbons, CxHy, and 3 chlorinated organic compounds, CxHyClz, were performed at Jungfraujoch (Switzerland) during eight years (2000-2007). The analysis of 4-h resolved non-methane volatile organic compounds (NMVOCs) was achieved by using gas-chromatography coupled with mass spectrometry (GC-MS). Variabilities in the NMVOC time series dataset were modeled by factor analysis (positive matrix factorization, PMF). Four factors defined the solution space and could be related to NMVOC sources and atmospheric processes. In order to facilitate factor interpretations the retrieved contributions were compared with independent measurements, such as trace gases (NOx, CO, and CH4) and back trajectories. The most dominant factor (accounting on average for ~42% of the total mixing ratio of the considered NMVOCs) was found to be most active in winter, co-varying with CO and CH4 and could be related to aged combustive emissions as well as natural gas distribution. The other three factors represent both industrial and evaporative sources. Trajectory statistics suggest that the most influential anthropogenic NMVOC sources for Jungfraujoch are located in Eastern Europe, but the Po Valley has been identified as a potential source region for specific industrial sources as well. Aging of the arriving NMVOCs, the derived factors as well as limitations of the methods are discussed. This is the first report of a PMF application on NMVOC data from a background mountain site.

Lanz, V. A.; Henne, S.; Staehelin, J.; Hueglin, C.; Vollmer, M. K.; Steinbacher, M.; Buchmann, B.; Reimann, S.

2009-05-01

316

Asian emissions in 2006 for the NASA INTEX-B mission  

NASA Astrophysics Data System (ADS)

A new inventory of air pollutant emissions in Asia in the year 2006 is developed to support the Intercontinental Chemical Transport Experiment-Phase B (INTEX-B) funded by the National Aeronautics and Space Administration (NASA). Emissions are estimated for all major anthropogenic sources, excluding biomass burning. We estimate total Asian anthropogenic emissions in the year 2006 as follows: 47.1 Tg SO2, 36.7 Tg NOx, 298.2 Tg CO, 54.6 Tg NMVOC, 29.2 Tg PM10, 22.2 Tg PM2.5, 2.97 Tg BC, and 6.57 Tg OC. We emphasize emissions from China because they dominate the Asia pollutant outflow to the Pacific and the increase of emissions from China since 2000 is of great concern. We have implemented a~series of improved methodologies to gain a better understanding of emissions from China, including a detailed technology-based approach, a dynamic methodology representing rapid technology renewal, critical examination of energy statistics, and a new scheme of NMVOC speciation for model-ready emissions. We estimate China's anthropogenic emissions in the year 2006 to be as follows: 31.0 Tg SO2, 20.8 Tg NOx, 166.9 Tg CO, 23.2 Tg NMVOC, 18.2 Tg PM10, 13.3 Tg PM2.5, 1.8 Tg BC, and 3.2 Tg OC. We have also estimated 2001 emissions for China using the same methodology and found that all species show an increasing trend during 2001-2006: 36% increase for SO2, 55% for NOx, 18% for CO, 29% for VOC, 13% for PM10, and 14% for PM2.5, BC, and OC. Emissions are gridded at a resolution of 30 min×30 min and can be accessed at our web site (http://mic.greenresource.cn/intex-b2006).

Zhang, Q.; Streets, D. G.; Carmichael, G. R.; He, K.; Huo, H.; Kannari, A.; Klimont, Z.; Park, I.; Reddy, S.; Fu, J. S.; Chen, D.; Duan, L.; Lei, Y.; Wang, L.; Yao, Z.

2009-02-01

317

Asian emissions in 2006 for the NASA INTEX-B mission.  

SciTech Connect

A new inventory of air pollutant emissions in Asia in the year 2006 is developed to support the Intercontinental Chemical Transport Experiment-Phase B (INTEX-B) funded by the National Aeronautics and Space Administration (NASA). Emissions are estimated for all major anthropogenic sources, excluding biomass burning. We estimate total Asian anthropogenic emissions in the year 2006 as follows: 47.1 Tg SO{sub 2}, 36.7 Tg NO{sub x}, 298.2 Tg CO, 54.6 Tg NMVOC, 29.2 Tg PM{sub 10}, 22.2 Tg PM{sub 2.5}, 2.97 Tg BC, and 6.57 Tg OC. We emphasize emissions from China because they dominate the Asia pollutant outflow to the Pacific and the increase of emissions from China since 2000 is of great concern. We have implemented a series of improved methodologies to gain a better understanding of emissions from China, including a detailed technology-based approach, a dynamic methodology representing rapid technology renewal, critical examination of energy statistics, and a new scheme of NMVOC speciation for model-ready emissions. We estimate China's anthropogenic emissions in the year 2006 to be as follows: 31.0 Tg SO{sub 2}, 20.8 Tg NO{sub x}, 166.9 Tg CO, 23.2 Tg NMVOC, 18.2 Tg PM{sub 10}, 13.3 Tg PM{sub 2.5}, 1.8 Tg BC, and 3.2 Tg OC. We have also estimated 2001 emissions for China using the same methodology and found that all species show an increasing trend during 2001-2006: 36% increase for SO{sub 2}, 55% for NOx, 18% for CO, 29% for VOC, 13% for PM{sub 10}, and 14% for PM{sub 2.5}, BC, and OC. Emissions are gridded at a resolution of 30 min x 30 min and can be accessed at our web site (http://mic.greenresource.cn/intex-b2006).

Zhang, Q.; Streets, D. G.; Carmichael, G. R.; He, K.; Huo, H.; Kannari, A.; Klimont, Z.; Park, I.; Reddy, S.; Fu, J.S.; Chen, D.; Duan, L.; Lei, Y.; Wang, L.; Yao, Z.; Tsinghua Univ.; Univ. of Iowa; International Inst. for Applied Systems Analysis; Hankuk Univ. of Foreign Studies; UK Met Office; Univ. of Tennessee

2009-01-01

318

Signal enhancement in solution-cathode glow discharge — optical emission spectrometry via low molecular weight organic compounds  

NASA Astrophysics Data System (ADS)

HCOOH, CH3COOH, and CH3CH2OH were used as chemical modifiers in a solution-cathode glow discharge. Emission was measured directly from the discharge, without a gas-liquid separator or a secondary excitation source. Emission from Ag, Se, Pb, and Hg was strongly enhanced, and the detection limits (DL) for these elements were improved by up to an order of magnitude using a combination of HCOOH and HNO3 compared to using HNO3 alone. The DL was measured for Mg (1 ?g/L), Fe (10 ?g/L), Ni (6 ?g/L), Cu (6 ?g/L), Pb (1 ?g/L), Ag (0.1 ?g/L), Se (300 ?g/L), and Hg (2 ?g/L). Coefficients of determination (R2) were between 0.9986 and 0.9999. A voltage of 1 kV was used, which produced a current of approximately 70 mA.

Doroski, Todd A.; Webb, Michael R.

2013-10-01

319

Mapping and profile of emission sources for airborne volatile organic compounds from process regions at a petrochemical plant in Kaohsiung, Taiwan.  

PubMed

This work surveyed five process regions inside a petrochemical plant in Taiwan to characterize the profiles of airborne volatile organic compounds (VOCs) and locate emission sources. Samples, taken with canisters, were analyzed with gas chromatography-mass spectrometry according to the TO-14 method. Each region was deployed with 24 sampling sites, sampled twice, and 240 samples in total were measured during the survey period. All of the data were consolidated into a database on Excel to facilitate retrieval, statistical analysis, and presentation in the form of a table or graph, and, subsequently, the profile of VOCs was elucidated. Emission sources were located by mapping the concentration distribution of either an individual or a type of species in terms of contour maps on Surfer. Through the cross-analysis of data, the abundant VOCs included alkenes, dienes, alkanes, and aromatics. A total of 19 emission sources were located from these five regions. The sources for alkanes stood inside first, third aromatic, and fourth naphtha cracking regions, whereas the ones for alkenes were inside two naphtha cracking regions. The sources for dienes were found inside the third naphtha cracking region alone; in contrast, the sources for aromatics were universally traced except inside the third naphtha cracking region. The measured intensity for sources mostly ranged from 1000 to 7000 ppb. PMID:16805407

Chen, Ching-Liang; Fang, Hung-Yuan; Shu, Chi-Min

2006-06-01

320

Emissions and ambient distributions of Biogenic Volatile Organic Compounds (BVOC) in a Ponderosa pine ecosystem: interpretation of PTR-MS mass spectra  

NASA Astrophysics Data System (ADS)

Two proton-transfer-reaction mass spectrometry systems were deployed at the Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics and Nitrogen-Southern Rocky Mountain 2008 field campaign (BEACHON-SRM08; July to September 2008) at the Manitou Forest observatory in a Ponderosa pine woodland near Woodland Park, Colorado USA to simultaneously measure BVOC emissions and ambient distributions of their oxidation products. Here, we present mass spectral analysis in a wide range of masses (m/z=40+ to 210+) to assess our understanding of BVOC emissions and their photochemical process inside of the forest canopy. The biogenic terpenoids, 2-methyl-3-butene-2-ol (MBO, 50.2%) and several monoterpenes (MT, 33.5%) were identified as the dominant BVOC emissions from a transmission corrected mass spectrum, averaged over the daytime (11 am to 3 p.m., local time) of three days. To assess contributions of oxidation products of local BVOC, we calculate a oxidation product spectrum with the OH- and ozone-initiated oxidation product distribution mass spectra of two major BVOC at the ecosystem (MBO and ?-pinene) that were observed from laboratory oxidation experiments. A majority (~73%) of the total signal could be explained by known compounds. The remainder are attributed to oxidation products of BVOC, emitted from nearby ecosystems and transported to the site, and oxidation products of unidentified BVOC emitted from the Ponderosa pine ecosystem.

Kim, S.; Karl, T.; Guenther, A.; Tyndall, G.; Orlando, J.; Harley, P.; Rasmussen, R.; Apel, E.

2009-10-01

321

Phenolic Compounds and Cell Structure in Bilberry Leaves Affected by Emissions from a Zn–Pb Smelter  

Microsoft Academic Search

Vaccinium myrtillus L. is a common shrub in the herbaceous layer of pine forests. In connection with resistance to pollution it has been widely\\u000a used in the environmental monitoring based on heavy metal accumulations in the foliage. The present study investigates leaves\\u000a of bilberry growing under influence of emissions from a Zn–Pb smelter. Determination of heavy metal levels by AAS

D. Bia?o?ska; A. M. Zobel; M. Kura?; T. Tykarska; K. Sawicka-Kapusta

2007-01-01

322

Asthma and the indoor environment: the significance of emission of formaldehyde and volatile organic compounds from newly painted indoor surfaces  

Microsoft Academic Search

As a part of the worldwide European Community Respiratory Health Survey, possible relations between asthma and emissions\\u000a from newly painted indoor surfaces were studied. The participants (n= 562) answered a self-administered questionnaire, with questions on symptoms and indoor exposures, including indoor painting,\\u000a during the last 12 months. The participants also underwent a structured interview, spirometry, peak flow measurements at home

G. Wieslander; D. Norbäck; E. Björnsson; C. Janson; G. Boman

1996-01-01

323

Fast online emission monitoring of volatile organic compounds (VOC) in wastewater and product streams (using stripping with direct steam injection).  

PubMed

Open-loop stripping analysis (also referred to as dynamic headspace) is a very flexible and robust technology for online monitoring of volatile organic compounds in wastewater or coolant. However, the quality and reliability of the analytical results depend strongly on the temperature during the stripping process. Hence, the careful and constant heating of the liquid phase inside the stripping column is a critical parameter. In addition, this stripping at high temperatures extends the spectrum of traceable organics to less volatile and more polar compounds with detection limits down to the ppm-level. This paper presents a novel and promising approach for fast, efficient, and constant heating by the direct injection of process steam into the strip medium. The performance of the system is demonstrated for temperatures up to 75 °C and traces of various hydrocarbons in water (e.g., tetrahydrofuran, methanol, 1-propanol, n-butanol, ethylbenzene). PMID:22186871

Schocker, Alexander; Lissner, Bert

2011-12-21

324

Nanoscale structural characteristics and electron field emission properties of transition metal-fullerene compound TiC60 films  

Microsoft Academic Search

Transition-metal compound TiC60 thin films were grown by co-deposition from two separated sources of fullerene C60 powder and titanium. Study of structural properties of the films, by Raman spectroscopy, atomic force microscopy, and scanning tunneling spectroscopy reveals that the films have a deformed C60 structure with certain amount of sp3 bonds and a rough surface with a large number of

Jian Chen; Jianbin Xu; K. Xue; J. An; Ning Ke; W. Cao; H. B. Xia; J. Shi; D. C. Tian

2005-01-01

325

Atmospheric emissions and attenuation of non-methane organic compounds in cover soils at a French landfill  

Microsoft Academic Search

In addition to methane (CH4) and carbon dioxide (CO2), landfill gas may contain more than 200 non-methane organic compounds (NMOCs) including C2+-alkanes, aromatics, and halogenated hydrocarbons. Although the trace components make up less than 1% v\\/v of typical landfill gas, they may exert a disproportionate environmental burden. The objective of this work was to study the dynamics of CH4 and

C. Scheutz; J. Bogner; J. P. Chanton; D. Blake; M. Morcet; C. Aran; P. Kjeldsen

2008-01-01

326

Emission of Plutella xylostella-Induced Compounds from Cabbages Grown at Elevated CO2 and Orientation Behavior of the Natural Enemies1  

PubMed Central

Several plant species defend themselves indirectly from herbivores by producing herbivore-induced volatile compounds that attract the natural enemies of herbivores. Here we tested the effects of elevated atmospheric CO2 (720 ?mol mol?1) concentration on this indirect defense, physiological properties, and constitutive and induced emissions of white cabbage (Brassica oleracea ssp. capitata, cvs Lennox and Rinda). We monitored the orientation behavior of the generalist predator Podisus maculiventris (Heteroptera: Pentatomidae) and the specialist parasitoid Cotesia plutellae (Hymenoptera: Braconidae) to plants damaged by Plutella xylostella (Lepidoptera: Plutellidae) in the Y-tube olfactometer. Elevated CO2 levels did not affect stomatal densities but reduced specific leaf area and increased leaf thickness in cv Lennox. In addition to enhanced constitutive monoterpene emission, P. xylostella-damaged cabbages emitted homoterpene (E)-4,8-dimethyl-1,3,7-nonatriene, sesquiterpene (E,E)-?-farnesene, and (Z)-3-hexenyl acetate. Growth at elevated CO2 had no significant effect on the emissions expressed per leaf area, while minor reduction in the emission of homoterpene (E)-4,8-dimethyl-1,3,7-nonatriene and (E,E)-?-farnesene was observed at elevated CO2 in one of two experiments. The generalist predator P. maculiventris discriminated only between the odors of intact and P. xylostella-damaged cv Rinda plants grown at ambient CO2 concentration, preferring the odor of the damaged plants. The specialist parasitoid C. plutellae preferred the odor of damaged plants of both cultivars grown at ambient CO2 but did not detect damaged cv Lennox plants grown at elevated CO2. The results suggest that elevated atmospheric CO2 concentration could weaken the plant response induced by insect herbivore feeding and thereby lead to a disturbance of signaling to the third trophic level.

Vuorinen, Terhi; Nerg, Anne-Marja; Ibrahim, M.A.; Reddy, G.V.P.; Holopainen, Jarmo K.

2004-01-01

327

Emissions and ambient distributions of Biogenic Volatile Organic Compounds (BVOC) in a ponderosa pine ecosystem: interpretation of PTR-MS mass spectra  

NASA Astrophysics Data System (ADS)

Two proton-transfer-reaction mass spectrometry systems were deployed at the Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics and Nitrogen-Southern Rocky Mountain 2008 field campaign (BEACHON-SRM08; July to September, 2008) at the Manitou Forest Observatory in a ponderosa pine woodland near Woodland Park, Colorado USA. The two PTR-MS systems simultaneously measured BVOC emissions and ambient distributions of their oxidation products. Here, we present mass spectral analysis in a wide range of masses (m/z 40+ to 210+) to assess our understanding of BVOC emissions and their photochemical processing inside of the forest canopy. The biogenic terpenoids, 2-methyl-3-butene-2-ol (MBO, 50.2%) and several monoterpenes (MT, 33.5%) were identified as the dominant BVOC emissions from a transmission corrected mass spectrum (PTR-MS), averaged over the daytime (11 a.m. to 3 p.m., local time) of three days. To assess contributions of oxidation products of local BVOC, we calculate an oxidation product spectrum with the OH- and ozone-initiated oxidation product distribution mass spectra of two major BVOC emissions at the ecosystem (MBO and ?-pinene) that were observed from laboratory oxidation experiments. The majority (~76%) of the total signal in the transmission corrected PTR-MS spectra could be explained by identified compounds. The remainder are attributed to oxidation products of BVOC emitted from nearby ecosystems and transported to the site, and oxidation products of unidentified BVOC emitted from the ponderosa pine ecosystem.

Kim, S.; Karl, T.; Guenther, A.; Tyndall, G.; Orlando, J.; Harley, P.; Rasmussen, R.; Apel, E.

2010-02-01

328

Asymmetrical fission and statistical emission of complex fragments from the highly excited {sup 47}V compound nucleus  

SciTech Connect

The properties of the fully damped (deep-inelastic and orbiting) and fusion (evaporation and fission) processes have been investigated in three entrance channels leading to the same {sup 47} V compound nucleus at high excitation energies. No entrance channel effect has been observed in either the evaporation residue or the fission-like yields in contrast to the {sup 28}Si + {sup 12}C and {sup 24}Mg + {sup 16}O reactions in which the orbiting process still persists. The asymmetrical elemental distributions of the fully energy relaxed fragments are well described by fusion-fission models based respectively on the scission point and saddle point pictures. Finally a general discussion of the competition between orbiting and fusion-fission mechanisms in light heavy-ion reactions is presented in the framework of their calculated available number of open channels.

Beck, C.; Djerroud, B.; Haas, F.; Freeman, R.M.; Hachem, A.; Heusch, B.; Morsad, A.; Vuillet-A-Crilles, M.; Youlal, M.; Abe, Y. [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Dayras, R.; Wieleczko, J.P.; Legrain, R.; Pollaco, E. [CEA Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France); Ray, A.; Shapira, D.; Campo, J.G.D.; Kim, H.J. [Oak Ridge National Lab., TN (United States); Cavallaro, S.; De Fillippo, E.; Lanzano, G.; Pagano, A.; Sperduto, M.L. [Istituto Nazionale di Fisica Nucleare, Catania (Italy); Matsuse, T. [Shinshu Univ., Matsumoto, Nagano (Japan); Sanders, S.J. [Kansas Univ., Lawrence, KS (United States)

1991-12-31

329

Asymmetrical fission and statistical emission of complex fragments from the highly excited sup 47 V compound nucleus  

SciTech Connect

The properties of the fully damped (deep-inelastic and orbiting) and fusion (evaporation and fission) processes have been investigated in three entrance channels leading to the same {sup 47} V compound nucleus at high excitation energies. No entrance channel effect has been observed in either the evaporation residue or the fission-like yields in contrast to the {sup 28}Si + {sup 12}C and {sup 24}Mg + {sup 16}O reactions in which the orbiting process still persists. The asymmetrical elemental distributions of the fully energy relaxed fragments are well described by fusion-fission models based respectively on the scission point and saddle point pictures. Finally a general discussion of the competition between orbiting and fusion-fission mechanisms in light heavy-ion reactions is presented in the framework of their calculated available number of open channels.

Beck, C.; Djerroud, B.; Haas, F.; Freeman, R.M.; Hachem, A.; Heusch, B.; Morsad, A.; Vuillet-A-Crilles, M.; Youlal, M.; Abe, Y. (Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires); Dayras, R.; Wieleczko, J.P.; Legrain, R.; Pollaco, E. (CEA Centre d'Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)); Ray, A.; Shapira, D.; Campo, J.G.D.; Kim, H.J. (Oak Ridge National Lab., TN (United States

1991-01-01

330

Measurement of ?-emission branching ratios for ^{154,156,158}Gd compound nuclei: Tests of surrogate nuclear reaction approximations for (n,?) cross sections  

NASA Astrophysics Data System (ADS)

The surrogate nuclear reaction method can be used to determine neutron-induced reaction cross sections from measured decay properties of a compound nucleus created using a different reaction and calculated formation cross sections. The reliability of (n,?) cross sections determined using the Weisskopf-Ewing and ratio approximations are explored for the Gd155,157(n,?) reactions. Enriched gadolinium targets were bombarded with 22-MeV protons and ? rays were detected in coincidence with scattered protons using the Silicon Telescope Array for Reaction Studies/Livermore-Berkeley Array for Collaborative Experiments (STARS/LiBerACE) silicon and germanium detector arrays. The ?-emission probabilities for the Gd154,156,158 compound nuclei were measured at excitation energies up to 12 MeV. It is found that the approximations yield results that deviate from directly measured Gd155,157(n,?) cross sections at low energies. To extract reliable cross sections, a more sophisticated analysis should be developed that takes into account angular-momentum differences between the neutron-induced and surrogate reactions.

Scielzo, N. D.; Escher, J. E.; Allmond, J. M.; Basunia, M. S.; Beausang, C. W.; Bernstein, L. A.; Bleuel, D. L.; Burke, J. T.; Clark, R. M.; Dietrich, F. S.; Fallon, P.; Gibelin, J.; Goldblum, B. L.; Lesher, S. R.; McMahan, M. A.; Norman, E. B.; Phair, L.; Rodriquez-Vieitez, E.; Sheets, S. A.; Thompson, I. J.; Wiedeking, M.

2010-03-01

331

Determination of white phosphorus residues in ducks: An atomic emission detection/compound-independent calibration-based method of generating residue data for risk assessment and environmental monitoring  

SciTech Connect

Analysis of phosphorus concentrations in the gizzards of ducks harvested from munitions sites is necessary to ascertain if acute phosphorus toxicity was the cause of death and to estimate potential secondary hazards to predators and scavengers, such as eagles that readily consume the dead ducks. Gas chromatography-atomic emission detection analysis permitted compound-independent quantification of white phosphorus standards following analysis of the stable phosphorus-containing compound triethyl phosphate. The white phosphorus standards were then used to quantify white phosphorus residues in duck gizzard extracts by gas chromatography-flame photometric detection analysis. For gizzards containing less than 0.01 {micro}g of phosphorus, quantification was based on a three-point calibration curve. For gizzards containing 0.01 {micro}g or more of white phosphorus, single-point calibration was used. Mean recoveries for phosphorus-fortified gizzards ranged from 73 to 91%. The method limit of detection was 0.013 {micro}g of phosphorus. This method was successfully applied to the quantification of white phosphorus in ducks collected from Eagle River Flats, AK. Potential applications to risk assessment and environmental monitoring are also discussed.

Johnston, J.J.; Goldade, D.A.; Kohler, D.J.; Cummings, J.L.

2000-05-01

332

Measurement of gamma-emission branching ratios for {sup 154,156,158}Gd compound nuclei: Tests of surrogate nuclear reaction approximations for (n,gamma) cross sections  

SciTech Connect

The surrogate nuclear reaction method can be used to determine neutron-induced reaction cross sections from measured decay properties of a compound nucleus created using a different reaction and calculated formation cross sections. The reliability of (n,gamma) cross sections determined using the Weisskopf-Ewing and ratio approximations are explored for the {sup 155,157}Gd(n,gamma) reactions. Enriched gadolinium targets were bombarded with 22-MeV protons and gamma rays were detected in coincidence with scattered protons using the Silicon Telescope Array for Reaction Studies/Livermore-Berkeley Array for Collaborative Experiments (STARS/LiBerACE) silicon and germanium detector arrays. The gamma-emission probabilities for the {sup 154,156,158}Gd compound nuclei were measured at excitation energies up to 12 MeV. It is found that the approximations yield results that deviate from directly measured {sup 155,157}Gd(n,gamma) cross sections at low energies. To extract reliable cross sections, a more sophisticated analysis should be developed that takes into account angular-momentum differences between the neutron-induced and surrogate reactions.

Scielzo, N. D.; Escher, J. E.; Bernstein, L. A.; Bleuel, D. L.; Burke, J. T.; Dietrich, F. S.; Lesher, S. R.; Sheets, S. A.; Thompson, I. J. [Physical Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Allmond, J. M.; Beausang, C. W. [Department of Physics, University of Richmond, Richmond, Virginia 23173 (United States); Basunia, M. S.; Clark, R. M.; Fallon, P.; Gibelin, J.; McMahan, M. A.; Phair, L. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Goldblum, B. L. [Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States); Norman, E. B. [Physical Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States); Rodriquez-Vieitez, E. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States)

2010-03-15

333

Regional biogenic emissions of reactive volatile organic compounds (BVOC) from forests: First results on process studies, modelling and validation experiments (BEWA2000)  

NASA Astrophysics Data System (ADS)

The overall objective of the research consortia is to develop for a forest canopy a prognostic, validated emission model for primary and secondary volatile organic compounds (VOC) to be used for estimating regional biogenic emissions with a higher spatial and temporal resolution than present. To achieve this objective requires a better description of biosynthetic processes as well as chemical degradation mechanisms for reactive biogenic VOC in combination with a process-based model and latest vegetation specific land use information. Up to now several highlights were achieved within the different key activities. In the section model development a process-based isoprenoid emission model was supplemented with new differential equations especially taking into account the influence of transport-resistances for leaf gas-exchange. In biochemical process-studies related to the formation of isoprene in leaves it turned out that during daytime about 20-70% of the total carbon delivered to poplar leaves (photosynthesis + other sources) was derived from xylem-transported sugars. This finding indicates that xylem-delivered carbon may indeed act as a significant alternative carbon source for isoprenoid biosynthesis. First chemical process studies on the reaction of limonene with NO3 radicals (observed in the night and under low light conditions) in the EUPHORE (European Photoreactor) demonstrated a secondary particle formation. At the field site Waldstein (Fichtelgebirge) this reaction may result in maximum pinonealdhyde concentrations in the air and on particles observed in night periods. A first analysis of particle size distributions over the Norway spruce canopy showed the appearance of small particles (< 10nm) during early daytime. The first results demonstrate that the proposed approach of combining interdisciplinary field, laboratory and modelling exercises to address the complexity of the biosphere/atmosphere exchange of reactive trace gases will contribute significantly to enhance our knowledge in this field needed for improving process based models. However, still poorly understood processes (e.g air chemistry under low light conditions, biochemical control of VOC emission) require further studies. It will be a challenging task in the future to close the reactive carbon mass-balance and to see how the new models are able to simulate more complex situations, e.g. the results from the ECHO project.

Rappenglück, B.; Bewa2000 Team

2003-04-01

334

Global sources of non-CO2 greenhouse gas emissions: regional trends, uncertainties and options for emission reductions  

NASA Astrophysics Data System (ADS)

An overview will be presented of sources and trends of global emissions of direct non-CO2 greenhouse gases CH4, N2O and the fluorinated gases HFCs, PFCs and SF6, which are addressed in the Kyoto protocol. Special attention will be given to regional source trends, estimated uncertainties and most recent global emission trends. In addition, the most significant options for emission reductions will be discussed in view of medium term emission scenarios that were meant to illustrate future trends without the effects climate policy. For estimating the recent global emission trends a special approach was used to compile fast annual updates of the EDGAR global emission inventories, based on the more detailed previous version. We present an overview of the approaches used for this `Fast Track' for the different source sectors. Results are presented for 1995-2002 for various anthropogenic sources at regional scales including an estimate of the accuracies achieved. A similar overview will be provided for the emissions of the ozone precursors NOx, CO and NMVOC and of black carbon. Tropospheric ozone and black carbon are both greenhouse gases, which are not considered in the Kyoto protocol, but in industrialised countries the emissions that cause them are often part of environmental policy on local and regional air quality.

Olivier, J. G.; van Aardenne, J. A.; Peters, J. A.

2005-05-01

335

Production of phenolics and the emission of volatile organic compounds by perennial ryegrass (Lolium perenne L.)/Neotyphodium lolii association as a response to infection by Fusarium poae.  

PubMed

Grasses very often form symbiotic associations with Neotyphodium/Epichloë endophytic fungi. These endophytes often allow the host grass to be protected from different pathogens. However, there is little known about the mechanisms of such endophyte influence on the host. Thus, the purpose of this research was to examine the effect of the N. lolii endophyte on the total production of phenolic compounds, VOCs emission and the resistance of three perennial ryegrass genotypes infected by pathogenic Fusarium poae. Analyses of total phenolics content were performed in control (not inoculated) and inoculated plants after 1, 2, 3, 4, 5, and 6 days (DAI) and for VOCs after 0, 3, 6 and 12 DAI. The presence of endophytes significantly reduced the disease index in two of the three genotypes relative to that in E-. Plants infected by N. lolii exhibited higher production of phenolics relative to the E- plants. The highest amounts of phenolics were observed on the second and sixth DAI. Genotype Nl22 showed the strongest effect of the endophyte on the production of phenolics, which increased by over 61%. Both the endophyte infected and non-infected plants emitted most abundantly two GLVs ((Z)-3-hexenal, (Z)-3-hexen-1-yl acetate), three terpenes (linalool, (Z)-ocimene, ?-caryophyllene) and three shikimic acid pathway derivatives (benzyl acetate, indole, and methyl salicylate). The endophyte presence and the intervals of VOCs detection were a highly significant source of variation for all emitted volatiles (P<0.001). The genotype of the perennial ryegrass significantly affected only the emission of methyl salicylate (P<0.05) and ?-caryophyllene (P<0.05). Most of the VOCs ((Z)-3-hexen-1-yl acetate, (Z)-3-hexenal, linalool and methyl salicylate) reached their highest levels of emission on the sixth DAI, when averaged over genotypes and endophyte status. The results highlight the role of Neotyphodium spp. in the mediation of quadro-trophic interactions among plants, symbiotic endophytes, invertebrate herbivores and plant pathogenic fungi. Our results also confirm the fact that symbiotic plants can activate a defense reaction faster than non-symbiotic plants after a pathogen attack. Thus, N. lolii can be involved in the defense of perennial ryegrass against pathogens and potentially could be central to the host plants' protection. PMID:23566872

Pa?ka, Dariusz; Piesik, Dariusz; Jeske, Ma?gorzata; Baturo-Cie?niewska, Anna

2013-04-06

336

EMISSION, FATE, AND CONTRIBUTION OF BIOGENIC VOLATILE ORGANIC COMPOUNDS TO ORGANIC AEROSOL FORMATION IN THE PRESENCE OF ANTHROPOGENIC POLLUTION: MEASUREMENTS AND MODELING DURING SOAS  

EPA Science Inventory

The primary deliverable products will be measurements of VOC emission and deposition on spatial and temporal scales that are optimal for evaluating and improving regional models. Outcomes will include approaches for quantifying VOC emission uncertainties and identifying missing V...

337

Influence of time, surface-to-volume ratio, and heating process (continuous or intermittent) on the emission rates of selected carbonyl compounds during thermal oxidation of palm and soybean oils.  

PubMed

The aim of this work was to compare the emission rates of selected carbonyl compounds (CC) produced by palm and soybean oils when heated at 180 degrees C in the presence of air, through different time intervals and at different surface-to-volume ratios ( S/ V), in continuous and intermittent processes. The CC were collected and derivatized onto silica C18 cartridges impregnated with an acid 2,4-dinitrophenylhidrazine solution, followed by extraction with acetonitrile and analysis by HPLC-UV and, in some cases, HPLC-MS with electrospray ionization. Among the CC quantified, namely, acetaldehyde, acrolein, propanal, butanal, hexanal, 2-heptenal, and 2-octenal, acrolein was the main emission in both oils and all S/ V ratios, followed by hexanal and 2-heptenal. The soybean oil has presented greater emission rates of acrolein than palm oil. When different S/ V ratios used during the heating process of the oil were compared, the emission rates, in general, were directly related to them, although saturated and nonsaturated CC have had different behaviors toward oxidation reactions. During intermittent heating, there was a trend of increasing emission rates of saturated aldehydes, whereas the opposite was observed with unsaturated aldehydes, probably due to the reactivity of the double bond present in these compounds. PMID:18422332

da Silva, Thalita Oliveira; Pereira, Pedro Afonso de Paula

2008-04-19

338

Biogenic Volatile Organic Compound and Respiratory CO2 Emissions after 13C-Labeling: Online Tracing of C Translocation Dynamics in Poplar Plants  

PubMed Central

Background Globally plants are the primary sink of atmospheric CO2, but are also the major contributor of a large spectrum of atmospheric reactive hydrocarbons such as terpenes (e.g. isoprene) and other biogenic volatile organic compounds (BVOC). The prediction of plant carbon (C) uptake and atmospheric oxidation capacity are crucial to define the trajectory and consequences of global environmental changes. To achieve this, the biosynthesis of BVOC and the dynamics of C allocation and translocation in both plants and ecosystems are important. Methodology We combined tunable diode laser absorption spectrometry (TDLAS) and proton transfer reaction mass spectrometry (PTR-MS) for studying isoprene biosynthesis and following C fluxes within grey poplar (Populus x canescens) saplings. This was achieved by feeding either 13CO2 to leaves or 13C-glucose to shoots via xylem uptake. The translocation of 13CO2 from the source to other plant parts could be traced by 13C-labeled isoprene and respiratory 13CO2 emission. Principal Finding In intact plants, assimilated 13CO2 was rapidly translocated via the phloem to the roots within 1 hour, with an average phloem transport velocity of 20.3±2.5 cm h?1. 13C label was stored in the roots and partially reallocated to the plants' apical part one day after labeling, particularly in the absence of photosynthesis. The daily C loss as BVOC ranged between 1.6% in mature leaves and 7.0% in young leaves. Non-isoprene BVOC accounted under light conditions for half of the BVOC C loss in young leaves and one-third in mature leaves. The C loss as isoprene originated mainly (76–78%) from recently fixed CO2, to a minor extent from xylem-transported sugars (7–11%) and from photosynthetic intermediates with slower turnover rates (8–11%). Conclusion We quantified the plants' C loss as respiratory CO2 and BVOC emissions, allowing in tandem with metabolic analysis to deepen our understanding of ecosystem C flux.

Ghirardo, Andrea; Gutknecht, Jessica; Zimmer, Ina; Bruggemann, Nicolas; Schnitzler, Jorg-Peter

2011-01-01

339

An Integrated Asian Emission Inventory and Analysis of its Characteristics to Support TRACE-P  

NASA Astrophysics Data System (ADS)

New emission inventories for year 2000 were developed in support of the NASA TRACE-P experiment and the NSF/NOAA ACE-Asia and NOAA ITCT 2K2 experiments. We combined our inventories into the ACESS (Ace-Asia and Trace-P Modeling and Emission Support System) to provide integrated emissions support for these field studies. To support field experiments and complex atmospheric models, highly resolved levels of spatial, temporal, and species-component detail are needed in the emission inventories. It is also important that these emission fields correctly reflect the spatial and temporal emission profiles of sources that were operating during the time period of the field campaigns, otherwise good agreement between models and experiment cannot be expected. Knowledge of source strengths and locations is also a valuable aid for interpreting observations and model results and ultimately choosing appropriate mitigation strategies. To satisfy these requirements, we included not only the gaseous pollutants SO2, NOx, CO, NMVOCs, NH3, CO2, but particulate pollutants such as Black Carbon, Organic Carbon, PM10, and PM2.5 for the study domain of Asia. NMVOCs were further classified into 19 sub-species. The data system includes information on various emission sources - fuels, economic sector activities, and geographic distribution of human activities for anthropogenic emission sources and volcano, fire, smoke, dust,and biogenic VOC emission activities for natural emission sources. Even though there remain considerable uncertainties associated with some of the emissions values due to source data uncertainty, we nevertheless feel that the confidence level for many species is high and that the inventory will prove valuable in gaining understanding about the formation of regional air pollution in Asia and its fate. In this paper we present the emission estimates for a wide variety of trace gases and aerosols. Furthermore, we present regional characteristics, and their relationship to differences in regional fuel usage and energy usage by sector. An evaluation of these emission estimates using results from 3-dimensional models and observations based analysis will be presented.

Woo, J.; Streets, D. G.; Carmichael, G. R.; Tang, Y.; Dorwart, J.; Pinnock, S.; Fu, Q.; Yarber, K.; Kurata, G.; Thongboonchoo, N.; White, A.

2002-12-01

340

Determination of butyl- and phenyltin compounds in human urine by HS-SPME after derivatization with tetraethylborate and subsequent determination by capillary GC with microwave-induced plasma atomic emission and mass spectrometric detection.  

PubMed

A headspace solid-phase micro-extraction (HS-SPME) method was developed and optimized for gas chromatographic separation and determination of commonly found organotin compounds in human urine after potential exposure. Butyl- and phenyltin compounds were in situ derivatized to ethylated derivatives by sodium tetraethylborate (NaBEt(4)) directly in the urine matrix. The relevant parameters affecting the yield of the SPME procedure were examined using tetrabutyltin as internal standard. The method was optimized for direct use in the analysis of undiluted human urine samples and mono-, di- and tri-substituted butyl- and phenyltin compounds could be determined after a 15-min headspace extraction time at room temperature. The selectivity of the microwave-induced plasma atomic emission detector (MIP-AED) as an element specific detector in combination with the relatively selective sample preparation technique of HS-SPME allowed the interference-free detection of the organotin compounds in all cases. A quadrupole mass spectrometer was used in parallel experiments as a detector for the confirmation of the identity molecular structure of the eluted compounds. The performance characteristics of the developed method are given for the determination of mixtures of these compounds. Finally the proposed method was applied to the analysis of several human urine samples. PMID:19203626

Zachariadis, G A; Rosenberg, E

2008-12-11

341

Observing Future Changes in the Photochemical Environment over Western North America due to Changes in Foreign Emissions: Lessons from Mount Bachelor  

NASA Astrophysics Data System (ADS)

There are multiple lines of evidence that springtime O3 mixing ratios are increasing over western North America, and rising O3 precursor emissions in East Asia are cited as potentially responsible. The Asian contribution to background O3 has two components: 1) O3 has a sufficient lifetime in spring such that O3 formed in the Asian boundary layer can cross the Pacific, and 2) O3 can be formed en-route as a result of peroxyacetyl nitrate (PAN) decomposition. To confidently detect a trend in a trace species such as O3, the trend must be large relative to both the natural variability and to the long-term measurement uncertainty, or alternatively one needs many years of observations. Detection of changes to the O3 budget in the air entering North America is challenging because consistent long-term observations are sparse. We report on measurements of PAN and O3 from the summit of Mount Bachelor (43.979°N, 121.687°W; 2.7 km a.s.l). These are the first consistent multi-year springtime measurements of PAN in the free troposphere over the U.S. Pacific Northwest. We combine the observed variability in PAN and O3 at Mount Bachelor with a range of possible future trends in these species to determine the observational requirements to detect such trends. A previous study using a global chemical transport model suggested that rising Asian emissions of nitrogen oxides (NOx) and non-methane volatile organic compounds (NMVOCs) will result in a relatively larger positive trend in PAN than O3 over western North America. We show that the timescale for PAN and O3 trend detection is equivalent when the PAN trend is approximately 4 times larger than the O3 trend. This reflects greater observed relative variability in PAN than O3. Our analysis suggests that if the true O3 trend over western North America due to rising Asian precursor emissions is on the order of 1% per year, it could be corroborated at a strategic representative site like Mount Bachelor in a relatively short timeframe with a direct analysis of mean O3 concentrations. Further information on attribution could be obtained with co-located PAN measurements, data segregation techniques and chemical modeling studies.

Fischer, E. V.; Jaffe, D. A.; Weatherhead, E. C.

2011-12-01

342

Uncertainty assessment of potential biogenic volatile organic compound emissions from forests with the Monte Carlo method: Case study for an episode from 1 to 10 July 2000 in Poland  

NASA Astrophysics Data System (ADS)

An uncertainty assessment of a volatile organic compounds (VOCs) emission inventory using a Monte Carlo study according to the "Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories" has been performed. For the episode of 1-10 July 2000 hourly biogenic VOC (BVOC) emissions from forests in Poland were calculated in 10 km × 10 km resolution with a semiempirical BVOC model (seBVOC). Driving parameters of the model were land cover, temperature, light intensity, foliar biomass, leaf area index (LAI), and plant-specific emission factors. The hourly meteorology input has been modeled with the nonhydrostatic Multiscale Climate Chemistry Model (MCCM). For each of the driving parameters, probability distribution functions (PDFs) based on the normal and log-normal distributions have been identified. Repeated runs of the seBVOC model in the Monte Carlo study with random figures drawn from the probability distribution functions yield the error distribution and the uncertainties. The results show an uncertainty in isoprene emission of the entire modeled period and modeling domain in the range from -71% to 73%, in monoterpene emissions in the range of -57% to 140%, and in other VOC (OVOC) emissions in the range of -55% to 57%. Uncertainties in daily estimates for the domain were higher ranging between -84% and 98% for isoprene, -63% and 147% for monoterpenes, and 63% and 72% for other VOCs. Largest uncertainty results from errors of the emission factors followed by errors in temperature and foliar biomass. These uncertainties cover only a subset of possible variables and are less than the total uncertainty.

Smiatek, G.; Bogacki, M.

2005-12-01

343

Applicability of solid-phase microextraction combined with gas chromatography atomic emission detection (GC-MIP AED) for the determination of butyltin compounds in sediment samples  

Microsoft Academic Search

The performance of solid-phase microextraction (SPME) applied to the determination of butyltin compounds in sediment samples is systematically evaluated. Matrix effects and influence of blank signals on the detection limits of the method are studied in detail. The interval of linear response is also evaluated in order to assess the applicability of the method to sediments polluted with butyltin compounds

J. Carpinteiro; I. Rodríguez; R. Cela

2004-01-01

344

Effect of biogenic volatile organic compound emissions on tropospheric chemistry during the Atmospheric Pollution Over the Paris Area (ESQUIF) campaign in the Ile-de-France region  

Microsoft Academic Search

This paper investigates the impact of biogenic isoprene and terpene emissions on photochemical species levels in the French Ile-de-France region during several photooxidant pollution episodes in summer 1998 and 1999 during the Atmospheric Pollution Over the Paris Area (ESQUIF) project. The effect of biogenic emissions on both ozone produced on a continental scale and advected in Ile-de-France and on ozone

C. Derognat; M. Beekmann; M. Baeumle; D. Martin; H. Schmidt

2003-01-01

345

Improving processes and parameterizations in the Model of Emissions of Gases and Aerosols from Nature version 2.1 (MEGAN2.1) using eddy covariance measurements of volatile organic compound fluxes  

NASA Astrophysics Data System (ADS)

MEGAN and other biogenic emission models need to represent the major processes controlling biogenic volatile organic compound (BVOC) fluxes and provide accurate parameterizations in order to accurately estimate regional to global distributions of BVOC emissions. The development of these models previously relied on enclosure measurements to identify the controlling processes and quantify parameters within the model framework. These efforts are valuable for characterizing the general magnitude of emissions from individual plant species and the major controls over BVOC emissions, but they provide a limited capability for parameterizing regional emissions due the inherent disturbance associated with enclosure techniques and the high leaf-to-leaf variability of BVOC emissions. Land surface modeling of carbon dioxide, water and energy fluxes have benefited tremendously from the hundreds of above-canopy flux towers operating nearly continuously for many years. In contrast, there are relatively few canopy scale measurements of BVOC fluxes even though both long-term tower-based measurements and regional airborne measurements using the eddy covariance technique have been successfully demonstrated. This presentation will summarize the present availability of tower and aircraft eddy covariance measurements of BVOC fluxes and describe strategies for increasing the availability of these data and prioritizing future measurements. Results from recent tower and airborne studies will be presented and compared with previous measurements. We will compare the MEGAN representations of leaf, canopy and landscape scale processes with alternative approaches used in other models, and characterize the uncertainties of those representations within MEGAN. Eddy covariance measurements will be used to investigate the adequacy of the model framework and to improve the model parameterizations.

Guenther, A. B.; Harley, P. C.; Karl, T.; Turnipseed, A.; Goldstein, A. H.; Misztal, P. K.; Potosnak, M.

2011-12-01

346

Applicability of solid-phase microextraction combined with gas chromatography atomic emission detection (GC-MIP AED) for the determination of butyltin compounds in sediment samples.  

PubMed

The performance of solid-phase microextraction (SPME) applied to the determination of butyltin compounds in sediment samples is systematically evaluated. Matrix effects and influence of blank signals on the detection limits of the method are studied in detail. The interval of linear response is also evaluated in order to assess the applicability of the method to sediments polluted with butyltin compounds over a large range of concentrations. Advantages and drawbacks of including an SPME step, instead of the classic liquid-liquid extraction of the derivatized analytes, in the determination of butyltin compounds in sediment samples are considered in terms of achieved detection limits and experimental effort. Analytes were extracted from the samples by sonication using glacial acetic acid. An aliquot of the centrifuged extract was placed on a vial where compounds were ethylated and concentrated on a PDMS fiber using the headspace mode. Determinations were carried out using GC-MIP AED. PMID:15365677

Carpinteiro, J; Rodríguez, I; Cela, R

2004-11-01

347

Investigating the response of East Asian ozone to Chinese emission changes using a linear approach  

NASA Astrophysics Data System (ADS)

To illuminate the issue of trans-boundary O3 pollution and regional O3 reduction policies in East Asia, we have investigated the East Asian ozone (O3) response to perturbations caused by Chinese anthropogenic emissions using the Community Multiscale Air Quality (CMAQ) model, a regional chemical transport model. The O3 responses have been examined for the range between -100 and +100% changes from the Chinese emissions level in 2004 in 10% intervals. We have found that springtime and summertime O3 responses both at the source and at the downwind areas can be regarded as linear over the range between -30 and +100% changes from the current emissions level. We therefore suggest that the perturbation between -30 and +100% is sufficiently small to avoid nonlinear chemical influence on O3 formation in a model experiment to investigate East Asian scale O3 source-receptor relationships. On the other hand, the O3 response is strongly nonlinear in April at Hong Kong, where the current NMVOCs/NOx ratio is low and the O3 production regime is easily moved to the NMVOCs sensitive region. The O3 responses to the NOx emission changes have been investigated using surface O3 concentrations at remote Japanese sites and tropospheric NO2 vertical column density (NO2 VCD) over central east China both with observations and with model simulations in springtime during 2003-2009. Analysis of satellite data shows that the observed range of NO2 VCD over central east China in 2003-2009 is the range between -25 and +34% from the 2004 level, which corresponds approximately to an emission variation between -21 and +29%. The O3 concentration in the downwind region during 2003-2009 responds linearly to a change of the NO2 VCD over central east China both in the model and in the observation. The corresponding O3 responses derived from surface observations at remote Japanese sites show linear features consistent with this expectation. The doubling of emissions, i.e., approximately 1.9-fold increase in the NO2 VCD from 2004, leads to O3 increments of 5 ppbv and 8 ppbv in the model and in the observation, respectively. The modeled O3 increase due to changes in NOx emission explains approximately 60% of the observed O3 trend at remote Japanese sites. Thus, approximately 40% of the observed O3 increase is unaccounted for by the NOx emissions growth.

Yamaji, Kazuyo; Uno, Itsushi; Irie, Hitoshi

2012-08-01

348

CONTROL OF INDUSTRIAL VOC (VOLATILE ORGANIC COMPOUND) EMISSIONS BY CATALYTIC INCINERATION. VOLUME 3. CATALYTIC INCINERATOR PERFORMANCE AT INDUSTRIAL SITE C-1  

EPA Science Inventory

Radian Corporation is conducting a testing program for the EPA (Contract No. 68-02-3171, Work Assignment 50) to document the performance of catalytic incinerators applied to industrial processes for volatile organic compound (VOC) control. Performance data collected at each test ...

349

Static SPME sampling of VOCs emitted from indoor building materials: prediction of calibration curves of single compounds for two different emission cells.  

PubMed

Solid-phase microextraction (SPME) is a powerful technique, easy to implement for on-site static sampling of indoor VOCs emitted by building materials. However, a major constraint lies in the establishment of calibration curves which requires complex generation of standard atmospheres. Thus, the purpose of this paper is to propose a model to predict adsorption kinetics (i.e., calibration curves) of four model VOCs. The model is based on Fick's laws for the gas phase and on the equilibrium or the solid diffusion model for the adsorptive phase. Two samplers (the FLEC® and a home-made cylindrical emission cell), coupled to SPME for static sampling of material emissions, were studied. A good agreement between modeling and experimental data is observed and results show the influence of sampling rate on mass transfer mode in function of sample volume. The equilibrium model is adapted to quite large volume sampler (cylindrical cell) while the solid diffusion model is dedicated to small volume sampler (FLEC®). The limiting steps of mass transfer are the diffusion in gas phase for the cylindrical cell and the pore surface diffusion for the FLEC®. In the future, this modeling approach could be a useful tool for time-saving development of SPME to study building material emission in static mode sampling. PMID:21400078

Mocho, Pierre; Desauziers, Valérie

2011-03-12

350

A BIOGENIC ROLE IN EXPOSURE TO TWO TOXIC COMPOUNDS  

EPA Science Inventory

Biogenic sources play an important role in ozone and particulate concentrations through emissions of volatile organic compounds. The same emissions also contribute to chronic toxic exposures from formaldehyde and acetaldehyde because each compound arises through primary and se...

351

Applications of Open-Path Fourier Transform Infrared for Identification of Volatile Organic Compound Pollution Sources and Characterization of Source Emission Behaviors  

Microsoft Academic Search

An open-path Fourier transform infrared spectroscopy (OP-FTIR) system was set up for 3-day continuous line-averaged volatile organic compound (VOC) monitoring in a paint manufacturing plant. Seven VOCs (toluene, m-xylene, p-xylene, styrene, methanol, acetone, and 2-butanone) were identified in the ambient environment. Daytime-only batch operation mode was well explained by the time-series concentration plots. Major sources of methanol, m-xylene, acetone, and

Chitsan Lin; Naiwei Liou; Endy Sun; Edwin Corporan; Matthew DeWitt; Chester Spicer; Michael Holdren; Kenneth Cowen; Alex Laskin; David Harris; Richard Shores; Robert Kagann; Ram Hashmonay; Francesca Sprovieri; Nicola Pirrone; Larry Jacobson; Brian Hetchler; David Schmidt; Richard Nicolai; Albert Heber; Ji-Qin Ni; Steven Hoff; Jacek Koziel; Yuanhui Zhang; David Beasley; David Parker; Roxolana Kashuba; Peter Scheff; Aniket Sawant; David Cocker; J. Miller; Tony Taliaferro; David Diaz-Sanchez; William Linn; Kenneth Clark; Henry Gong; Gustavo Olivares; Johan Strom; Christer Johansson; Lars Gidhagen

2008-01-01

352

Use of thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) on identification of odorant emission focus by volatile organic compounds characterisation.  

PubMed

Volatile organic compounds (VOCs) from several different municipal solid wastes' treatment plants in Mallorca (Spain) have been analysed by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). Ambient (immission) air was collected during February and March 2011 by active sampling onto sorbents Tenax™ TA and Carboxen™ 1000. The study presents the chemical characterisation of 93 volatile organic compounds (VOCs) from an overall set of 84 immission air samples. 70 VOCs were positively identified. The linear fit for all 93 external standard calibration, from 10 mg L(-1) to 150 mg L(-1) (n=4), was within the range 0.974compounds (RSCs) and municipal solid wastes show contribution of a wide sort of VOCs. The use of a chemometric approach for variable's reduction to 12 principal components enables evaluation of similarities and dissimilarities between facilities. PCA clearly related samples to its corresponding facility on the basis of their VOCs composition and the ambient temperature. PMID:22776256

Rodríguez-Navas, Carlos; Forteza, Rafael; Cerdà, Víctor

2012-07-07

353

Importance of activity data for improving the residential wood combustion emission inventory at regional level  

NASA Astrophysics Data System (ADS)

The contribution of residential wood combustion (RWC) to emission inventory at local level was estimated using a bottom-up approach for the Lombardy Region of North Italy. A survey, based on the CATI (Computer Assisted Telephone Interviewing) method, has been undertaken through 18,000 interviews. The interviews had the objective to characterize the RWC use in this region, in term of both total and municipal wood consumption. Details on the type of appliances used in RWC were also gathered. The results of the survey were then statistically analyzed in order to allow an estimate of RWC with high spatial resolution (i.e., at municipal level) in relation to the size and altitude of the territory. The work provides new evidence of the importance of wood combustion as a key source for PM and NMVOC emissions at local level, and thus highlights the importance of technological improvements and new policies aimed at emission reduction in this sector. Considering the great differences in average PM emission factors between low efficiency appliances (fireplaces, old stoves) and high efficiency ones (new stoves, pellet burners), this work emphasizes the importance of obtaining more detailed information on the types of wood appliances used for arriving at a reliable PM emission inventory for RWC.

Pastorello, Cinzia; Caserini, Stefano; Galante, Silvia; Dilara, Panagiota; Galletti, Fabio

2011-06-01

354

Constraining CO emission estimates using atmospheric observations  

NASA Astrophysics Data System (ADS)

We apply a four-dimensional variational (4D-Var) data assimilation system to optimize carbon monoxide (CO) emissions and to reduce the uncertainty of emission estimates from individual sources using the chemistry transport model TM5. In the first study only a limited amount of surface network observations from the National Oceanic and Atmospheric Administration Earth System Research Laboratory (NOAA/ESRL) Global Monitoring Division (GMD) is used to test the 4D-Var system. Uncertainty reduction up to 60% in yearly emissions is observed over well-constrained regions and the inferred emissions compare well with recent studies for 2004. However, since the observations only constrain total CO emissions, the 4D-Var system has difficulties separating anthropogenic and biogenic sources in particular. The inferred emissions are validated with NOAA aircraft data over North America and the agreement is significantly improved from the prior to posterior simulation. Validation with the Measurements Of Pollution In The Troposphere (MOPITT) instrument shows a slight improved agreement over the well-constrained Northern Hemisphere and in the tropics (except for the African continent). However, the model simulation with posterior emissions underestimates MOPITT CO total columns on the remote Southern Hemisphere (SH) by about 10%. This is caused by a reduction in SH CO sources mainly due to surface stations on the high southern latitudes. In the second study, we compare two global inversions to estimate carbon monoxide (CO) emissions for 2004. Either surface flask observations from NOAA or CO total columns from the MOPITT instrument are assimilated in a 4D-Var framework. In the Southern Hemisphere (SH) three important findings are reported. First, due to their different vertical sensitivity, the stations-only inversion increases SH biomass burning emissions by 108 Tg CO/yr more than the MOPITT-only inversion. Conversely, the MOPITT-only inversion results in SH natural emissions (mainly CO from oxidation of NMVOCs) that are 185 Tg CO/yr higher compared to the stations-only inversion. Second, MOPITT-only derived biomass burning emissions are reduced with respect to the prior which is in contrast to previous (inverse) modeling studies. Finally, MOPITT derived total emissions are significantly higher for South America and Africa compared to the stations-only inversion. This is likely due to a positive bias in the MOPITT V4 product. This bias is also apparent from validation with surface stations and ground-truth FTIR columns. In the final study we present the first inverse modeling study to estimate CO emissions constrained by both surface (NOAA) and satellite (MOPITT) observations using a bias correction scheme. This approach leads to the identification of a positive bias of maximum 5 ppb in MOPITT column-averaged CO mixing ratios in the remote Southern Hemisphere (SH). The 4D-Var system is used to estimate CO emissions over South America in the period 2006-2010 and to analyze the interannual variability (IAV) of these emissions. We infer robust, high spatial resolution CO emission estimates that show slightly smaller IAV due to fires compared to the Global Fire Emissions Database (GFED3) prior emissions. Moreover, CO emissions probably associated with pre-harvest burning of sugar cane plantations are underestimated in current inventories by 50-100%.

Hooghiemstra, P. B.

2012-06-01

355

Road traffic emission inventory for air quality modelling and to evaluate the abatement strategies: A case of Ho Chi Minh City, Vietnam  

NASA Astrophysics Data System (ADS)

A road traffic Emission Inventory (EI) is generated for Ho Chi Minh City (HCMC), Vietnam. For generating the EI for road traffic sources, we used the new EMISENS model, which combines the top-down and bottom-up approaches. The bulk emission factors of traffic stem from another study that estimated the emission factors for HCMC by using an inverse air quality model method. The results show that the motorcycles are responsible for the bulk of traffic emissions (contributing 94% of CO, 68% of NMVOC, 61% of SO2 and 99% of CH4). Four scenarios for reducing of the traffic emissions are designed using the HCMC's plan for reduction of emissions. Two scenarios are the reduction scenarios for the year of 2015 and 2020. In addition, two scenarios are the Business as Usual scenario for the year of 2015 and 2020. If the local government does not have any plan for reduction of emissions (scenario of Business as Usual) the emissions will increase rapidly. If the government follows the planning as set out by the local managers, the emissions of the city will decrease.

Ho, Bang Quoc; Clappier, Alain

2011-07-01

356

Applications of open-path Fourier transform infrared for identification of volatile organic compound pollution sources and characterization of source emission behaviors.  

PubMed

An open-path Fourier transform infrared spectroscopy (OP-FTIR) system was set up for 3-day continuous line-averaged volatile organic compound (VOC) monitoring in a paint manufacturing plant. Seven VOCs (toluene, m-xylene, p-xylene, styrene, methanol, acetone, and 2-butanone) were identified in the ambient environment. Daytime-only batch operation mode was well explained by the time-series concentration plots. Major sources of methanol, m-xylene, acetone, and 2-butanone were identified in the southeast direction where paint solvent manufacturing processes are located. However, an attempt to uncover sources of styrene was not successful because the method detection limit (MDL) of the OP-FTIR system was not sensitive enough to produce conclusive data. In the second scenario, the OP-FTIR system was set up in an industrial complex to distinguish the origins of several VOCs. Eight major VOCs were identified in the ambient environment. The pollutant detected wind-rose percentage plots that clearly showed that ethylene, propylene, 2-butanone, and toluene mainly originated from the tank storage area, whereas the source of n-butane was mainly from the butadiene manufacturing processes of the refinery plant, and ammonia was identified as an accompanying reduction product in the gasoline desulfuration process. Advantages of OP-FTIR include its ability to simultaneously and continuously analyze many compounds, and its long path length monitoring has also shown advantages in obtaining more comprehensive data than the traditional multiple, single-point monitoring methods. PMID:18581812

Lin, Chitsan; Liou, Naiwei; Sun, Endy

2008-06-01

357

Global chlorine emissions from biomass burning: Reactive Chlorine Emissions Inventory  

Microsoft Academic Search

Emissions of reactive chlorine-containing compounds from nine discrete classes of biomass burning were estimated on a 1° latitude by 1° longitude grid based on a biomass burning inventory for carbon emissions. Variations on approaches incorporating both emission ratios relative to CO and CO2 and the chlorine content of biomass burning fuels were used to estimate fluxes and associated uncertainties. Estimated,

Jürgen M. Lobert; William C. Keene; Jennifer A. Logan; Rosemarie Yevich

1999-01-01

358

Role of fossil fuel and wood burning emissions on Volatile Organic Compounds, Carbon monoxide and Black Carbon level and variability as determined from one-year measurements in Paris.  

NASA Astrophysics Data System (ADS)

Within the French program PRIMEQUAL-FRANCIPOL 2010-2013, measurements of gaseous precursors of secondary organic aerosols have been performed at the LHVP (Laboratoire d'Hygiene de la Ville de Paris), an urban background site of Paris. A continuous real-time monitoring strategy using the high sensitivity PTR-MS (Proton Transfer Reaction- Mass Spectrometer) has been implemented for the measurements of Volatile Organic Compounds (VOCs) during a whole year (02/2010-03/2011). The data were acquired in mass-scan mode thus, allowing to follow a very wide range of analytes, namely between m/z 18 and 151. This broad range of compounds includes both well-known VOCs and less studied ones, providing a great exploration potential and the opportunity to establish novel valuable information. This unique dataset will enable to acquire a better understanding of the diurnal, weekday and seasonal trends and to determine the main sources that drive VOCs variability in Paris. The preliminary results herein aim to distinguish the biomass burning from the fuel fossil emissions and to evaluate their impact on the measured volatile organic compounds using tracers Black Carbon (BC) and carbon monoxide (CO). BC was measured and separated into fuel fossil (FF) and wood burning (WB) contributions which can both be used as tracers. The obtained FF contributions to BC are well correlated with measured concentrations of acetaldehyde (m/z 45), acetone (m/z 59), hexanal (m/z 83), probably chloroethane (m/z 85), dimethylbenzene (m/z 107) and trimethylbenzene (TMB) while WB contributions to BC correlate nicely with methanol and the mass 97, maybe related to furfural which has already been identified in smoke from woodburning.

Sarda Esteve, R.; Gros, V.; Kalogridis, A.-C.; Sciare, J.

2012-04-01

359

Compound clusters in silicon dioxide obtained by N+, C+ and B+ high-dose ion implantation: nature of the blue cathodoluminescence emission and relationship with the embedded phases  

NASA Astrophysics Data System (ADS)

SiO2 films on Si substrates have been implanted at 600 °C by N++C+, N++B+ and N++C++B+ ions at two different doses, and subsequently thermal annealed. Cathodoluminescence measurements of the samples have shown three bands at 3.45, 2.7 and 2.1 eV. The 2.7 eV band, observed in all the samples but more intense in the N+B annealed samples, is due to oxygen deficiency centers, while the 3.45 eV one, only present in N+B and N+C+B samples, seems to be related to BN or B associated centers. Infrared spectra of the implanted films showed Si-O-B and h-BN bands in samples containing B, as well as a contribution about 1200 cm-1 assigned to a ternary compound in the N+C+B implant. No modes different than those of Si-O bond have been found in samples without B.

Cervera, M.; Hernández, M. J.; Rodríguez, P.; Piqueras, J.; Avella, M.; González, M. A.; Jiménez, J.

2005-03-01

360

75 FR 77758 - Approval and Promulgation of Air Quality Implementation Plans; Delaware; Limiting Emissions of...  

Federal Register 2010, 2011, 2012, 2013

...Delaware; Limiting Emissions of Volatile Organic Compounds From Portable Fuel Containers...to Delaware's regulation for Volatile Organic Compounds (VOC) from Consumer and Commercial...1141--Limiting Emissions of Volatile Organic Compounds from Consumer and...

2010-12-14

361

40 CFR Table 1 to Subpart D of... - Volatile Organic Compound (VOC), Content Limits for Architectural Coatings  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Volatile Organic Compound (VOC), Content Limits for...PROGRAMS (CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for...

2013-07-01

362

40 CFR Table 1 to Subpart B of... - Volatile Organic Compound (VOC) Content Limits for Automobile Refinish Coatings  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Volatile Organic Compound (VOC) Content Limits for Automobile...PROGRAMS (CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for...

2013-07-01

363

40 CFR Table 1 to Subpart B of... - Volatile Organic Compound (VOC) Content Limits for Automobile Refinish Coatings  

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Volatile Organic Compound (VOC) Content Limits for Automobile...CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for Automobile...

2009-07-01

364

40 CFR Table 1 to Subpart D of... - Volatile Organic Compound (VOC), Content Limits for Architectural Coatings  

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Volatile Organic Compound (VOC), Content Limits for Architectural...CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for...

2009-07-01

365

40 CFR Table 1 to Subpart D of... - Volatile Organic Compound (VOC), Content Limits for Architectural Coatings  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Volatile Organic Compound (VOC), Content Limits for Architectural...CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for...

2010-07-01

366

Comparing optimized CO emission estimates using MOPITT or NOAA surface network observations  

NASA Astrophysics Data System (ADS)

This paper compares two global inversions to estimate carbon monoxide (CO) emissions for 2004. Either surface flask observations from the National Oceanic and Atmospheric Administration Earth System Research Laboratory (NOAA/ESRL) Global Monitoring Division (GMD) or CO total columns from the Measurement of Pollution in the Troposphere (MOPITT) instrument are assimilated in a 4D-Var framework. Inferred emission estimates from the two inversions are consistent over the Northern Hemisphere (NH). For example, both inversions increase anthropogenic CO emissions over Europe (from 46 to 94 Tg CO/yr) and Asia (from 222 to 420 Tg CO/yr). In the Southern Hemisphere (SH), three important findings are reported. First, due to their different vertical sensitivity, the stations-only inversion increases SH biomass burning emissions by 108 Tg CO/yr more than the MOPITT-only inversion. Conversely, the MOPITT-only inversion results in SH natural emissions (mainly CO from oxidation of NMVOCs) that are 185 Tg CO/yr higher compared to the stations-only inversion. Second, MOPITT-only derived biomass burning emissions are reduced with respect to the prior which is in contrast to previous (inverse) modeling studies. Finally, MOPITT derived total emissions are significantly higher for South America and Africa compared to the stations-only inversion. This is likely due to a positive bias in the MOPITT V4 product. This bias is also apparent from validation with surface stations and ground-truth FTIR columns. Our results show that a combined inversion is promising in the NH. However, implementation of a satellite bias correction scheme is essential to combine both observational data sets in the SH.

Hooghiemstra, P. B.; Krol, M. C.; Bergamaschi, P.; de Laat, A. T. J.; van der Werf, G. R.; Novelli, P. C.; Deeter, M. N.; Aben, I.; Röckmann, T.

2012-03-01

367

Compound Interest  

NSDL National Science Digital Library

Albert Einstein called compound interest the 8th wonder of the world. Find out why compound interest and the time value of money are so important. What is Interest Click on the following link to read about the different types of interest. Loans and Interest So why learn about compound interest? Using time and interest to your advantage, you can make more money than you have ever dreamed of. See how the time value of ...

Riches, Ms.

2007-10-16

368

Carbocyclic compounds  

US Patent & Trademark Office Database

Novel carbocyclic compounds are described. The compounds generally comprise an acidic group, a basic group, a substituted amino or N-acyl and a group having an optionally hydroxylated alkane moiety. Pharmaceutical compositions comprising the inhibitors of the invention are also described. Methods of inhibiting neuraminidase in samples suspected of containing neuraminidase are also described. Antigenic materials, polymers, antibodies, conjugates of the compounds of the invention with labels, and assay methods for detecting neuraminidase activity are also described.

Bischofberger; Norbert W. (San Carlos, CA); Kim; Choung U. (San Carlos, CA); Lew; Willard (San Mateo, CA); Liu; Hongtao (Foster City, CA); Williams; Matthew A. (Foster City, CA)

1998-06-09

369

Historical gaseous and primary aerosol emissions in the United States from 1990-2010  

NASA Astrophysics Data System (ADS)

An accurate description of emissions is crucial for model simulations to reproduce and interpret observed phenomena over extended time periods. In this study, we used an approach based on activity data to develop a consistent series of spatially resolved emissions in the United States from 1990 to 2010. The state-level anthropogenic emissions of SO2, NOx, CO, NMVOC, NH3, PM10 and PM2.5 for a total of 49 sectors were estimated based on several long-term databases containing information about activities and emission controls. Activity data for energy-related stationary sources were derived from the State Energy Data System. Corresponding emission factors reflecting implemented emission controls were calculated back from the National Emission Inventory (NEI) for seven years (i.e. 1990, 1995, 1996, 1999, 2001, 2002 and 2005), and constrained by the AP-42 (US EPA's Compilation of Air Pollutant Emissions Factors) dataset. Activity data for mobile sources including different types of highway vehicles and non-highway equipments were obtained from highway statistics reported by the Federal Highway Administration. The trends in emission factors for highway mobile source were informed by the 2011 National Transportation Statistics. Emissions for all non-energy related sources were either scaled by the growth ratio of activity indicators or adjusted based on the NEI trends report. Because of the strengthened control efforts, particularly for the power sector and mobile sources, emissions of all pollutants except NH3 were reduced by half over the last two decades. The emission trends developed in this study are comparable with the NEI trend report and EDGAR (Emissions Database for Global Atmospheric Research) data, but better constrained by trends in activity data. Reductions in SO2 and NOx emissions agree well with the observed changes in ambient SO2 and NO2 concentrations, suggesting that the various controls on SO2 and NOx emissions implemented over the last two decades are well represented in the emission inventories developed in this study. These inventories were processed by SMOKE and are now ready to be used for regional chemistry transport model simulations over the 1990-2010 period.

Xing, J.; Pleim, J.; Mathur, R.; Pouliot, G.; Hogrefe, C.; Gan, C.-M.; Wei, C.

2012-11-01

370

Trend Detection in Satellite Observations of Formaldehyde Tropospheric Columns Using GOME, SCIAMACHY and GOME-2 Spectrometers  

NASA Astrophysics Data System (ADS)

Being a short-lived intermediate product in the oxidation of a large number of Non-Methane Volatile Organic Compounds (NMVOCs), formaldehyde (H2CO) constitutes a useful indicator of anthropogenic, biogenic and biomass burning hydrocarbons emissions in the troposphere. Therefore, over recent years, satellite observations of H2CO have been increasingly used in combination with tropospheric chemistry transport models for constraining emission inventories of NMVOC, through top-down inversion approaches. With satellite measurements being available since the launch of ERS-2 GOME in 1995, the eventual trend in NMVOCs emissions might be investigated. Trend analysis based on satellite data sets have been successfully applied for NOx (and more recently SO2) emissions over Eastern China. However, according to the current knowledge, the contribution of anthropogenic NMVOCs to the total H2CO column is relatively small and therefore, the expected trend in H2CO is smaller than the trend in NO2 columns. Added to the fact that H2CO column measurements have larger uncertainties than corresponding NO2 data, this has so far prevented any significant trend detection from H2CO satellite data sets. In this work, consolidated global distributions of formaldehyde columns derived from GOME, SCIAMACHY and GOME-2 instruments are used to analyze the temporal evolution of H2CO over industrialized areas in the period 1996-2009. A linear model with seasonal components has been used to fit the time series, taking into account the errors on the satellite observations as well as uncertainties related to possible biases between the different instruments. Results show that Asia, and more particularly Eastern China and the city of Shanghai, are the only regions in the world where statistically significant positive trends in H2CO columns are found. The satellite-based trends in H2CO columns are compared to reported trends in the REAS bottom-up inventory of NMVOCs emission in Asia.

de Smedt, Isabelle; Stavrakou, Jenny; Müller, Jean-François; van Roozendael, Michel

2010-05-01

371

Low emission turbo compound engine system  

SciTech Connect

A diesel or HHCI engine has an air intake and an exhaust for products of combustion. A pair of turbochargers receive the products of combustion in a series relationship and an exhaust aftertreatment device receive the products of combustion from the downstream turbine. A power turbine receives the output from the exhaust aftertreatment device and an EGR system of the power turbine passes a selected portion of the output to a point upstream of the upstream turbocharger compressor. A device adds fuel to the aftertreatment device to regenerate the particulate filter and the power turbine recoups the additional energy. The power turbine may be used to drive accessories or the prime output of the engine.

Vuk; Carl T. (Denver, IA)

2011-05-31

372

Air emissions monitoring  

Microsoft Academic Search

Continuous emissions monitors (CEMs) have the dual responsibilities of initially identifying the compounds within an air or gas stream and then, as the name implies, monitoring them. Some CEMs can measure and monitor from in-situ positions within a stack or duct. Others can extract a sample from the stack or duct for remote analysis. Other types of CEMs include ultraviolet

A. L. Kilbourne; C. O. Hodson

1996-01-01

373

Sealing off volatile emissions  

Microsoft Academic Search

As legislators around the world mandate cuts in the emissions of volatile organic compounds (VOCs), plant operators in the chemical process industries (CPI) are relying on new sealing technology to reduce leaks from valves, flanges, pumps and rotating machines. Such leaks account for over 33% of all the air toxics emitted from refineries and petroleum plants. Improving seals in different

Fouhy

1995-01-01

374

PASSENGER CAR HYDROCARBON EMISSIONS SPECIATION  

EPA Science Inventory

Emission factors for over 60 individual hydrocarbon compounds were determined for four passenger cars. The cars included a 1963 Chevrolet, a 1977 Mustang, and 1978 Monarch, and 1979 LTD II. The speciation data is reported for both tailpipe and evaporative emissions. The tailpipe ...

375

Organosulfur Compounds  

NSDL National Science Digital Library

Quiz questions from the organic chemistry question bank provide students with an excellent opportunity to review key concepts. This set of questions focuses on organosulfur compounds, with a special emphasis on thiols and sulfides.

Reich, Ieva

2007-10-30

376

The Chemiluminescence of Organometallic Compounds  

NASA Astrophysics Data System (ADS)

Studies on the liquid-phase and gas-phase reactions of organometallic compounds accompanied by the emission of light are described systematically and discussed. The influence of the magnetic field on the chemiluminescence of Grignard reagents and the study of the electrochemiluminescence of solutions of organometallic compounds are examined. The ways leading to further development of the field of the chemiluminescence of organometallic compounds and certain possible applications of the phenomenon in the monitoring of industrial processes are discussed. The bibliography includes 80 references.

Tolstikov, Genrikh A.; Bulgakov, Ramil G.; Kazakov, Valeri P.

1985-11-01

377

Emissions of ozone precursors from stationary sources  

Microsoft Academic Search

This paper discusses and critiques methods used to estimate emissions of, and create both aggregate and detailed modeling inventories for, nitrogen oxides (NOx), volatile organic compounds (VOC) and carbon monoxide (CO), the main pollutants involved in ozone formation. Emissions of sulfur dioxide (SO2) and methods to project emissions into the future are also briefly discussed. Many improvements have been made

M Placet; C. O Mann; R. O Gilbert; M. J Niefer

2000-01-01

378

NANOPARTICLE EMISSIONS OF WOOD COMBUSTION PROCESSES  

Microsoft Academic Search

Wood combustion processes produce smoke emissions, that are of concern to authorities and the public. These emissions include particulate matter (PM) covered with organic compounds that are known as carcinogens and respiratory irritants. On-line analytical methods were used to monitor smoke emissions of various types of wood combustion systems. A Scanning Mobility Particle Sizer (SMPS) was utilized to determine the

U. Wieser; C. K. Gaegauf

2000-01-01

379

Modeling an air pollution episode in northwestern United States: Identifying the effect of nitrogen oxide and volatile organic compound emission changes on air pollutants formation using direct sensitivity analysis  

Microsoft Academic Search

Air quality impacts of VOCs and NOx emissions from major sources over the northwestern United States are simulated. The comprehensive nested modeling system is comprised of three models: CMAQ, WRF and SMOKE. In addition, the DDM-3D is used to determine the sensitivities of pollutant concentrations to changes in precursor emissions during a severe smog episode in July of 2006. The

Alexandra P. Tsimpidi; Marcus Trail; Yongtao Hu; Athanasios Nenes; Armistead G. Russell

2012-01-01

380

Metallic compounds  

Microsoft Academic Search

Summary 1.The chemical interaction between metals or between metals and metalloids, which results in the formation of various substances having metallic properties, is characterized essentially by the formation of metallic solutions and metallic compounds.2.The chemical resemblance. and differences between metallic elements, which are associated with the dispositions of the elements in the same or different group of the periodic system,

I. I. Kornilo

1953-01-01

381

Air emissions inventory for the Idaho National Engineering Laboratory -- 1995 emissions report  

SciTech Connect

This report presents the 1995 update of the Air Emission Inventory for the Idaho National Engineering Laboratory (INEL). The INEL Air Emission Inventory documents sources and emissions of non-radionuclide pollutants from operations at the INEL. The report describes the emission inventory process and all of the sources at the INEL, and provides non-radionuclide emissions estimates for stationary sources. The air contaminants reported include nitrogen oxides, sulfur oxides, carbon monoxide, volatile organic compounds, particulates, and hazardous air pollutants (HAPs).

NONE

1996-06-01

382

Biomass burning in Asia : annual and seasonal estimates and atmospheric emissions.  

SciTech Connect

Estimates of biomass burning in Asia are developed to facilitate the modeling of Asian and global air quality. A survey of national, regional, and international publications on biomass burning is conducted to yield consensus estimates of 'typical' (i.e., non-year-specific) estimates of open burning (excluding biofuels). We conclude that 730 Tg of biomass are burned in a typical year from both anthropogenic and natural causes. Forest burning comprises 45% of the total, the burning of crop residues in the field comprises 34%, and 20% comes from the burning of grassland and savanna. China contributes 25% of the total, India 18%, Indonesia 13%, and Myanmar 8%. Regionally, forest burning in Southeast Asia dominates. National, annual totals are converted to daily and monthly estimates at 1{sup o} x 1{sup o} spatial resolution using distributions based on AVHRR fire counts for 1999--2000. Several adjustment schemes are applied to correct for the deficiencies of AVHRR data, including the use of moving averages, normalization, TOMS Aerosol Index, and masks for dust, clouds, landcover, and other fire sources. Good agreement between the national estimates of biomass burning and adjusted fire counts is obtained (R{sup 2} = 0.71--0.78). Biomass burning amounts are converted to atmospheric emissions, yielding the following estimates: 0.37 Tg of SO{sub 2}, 2.8 Tg of NO{sub x}, 1100 Tg of CO{sub 2}, 67 Tg of CO, 3.1 Tg of CH{sub 4}, 12 Tg of NMVOC, 0.45 Tg of BC, 3.3 Tg of OC, and 0.92 Tg of NH{sub 3}. Uncertainties in the emission estimates, measured as 95% confidence intervals, range from a low of {+-}65% for CO{sub 2} emissions in Japan to a high of {+-}700% for BC emissions in India.

Streets, D. G.; Yarber, K. F.; Woo, J.-H.; Carmichael, G. R.; Decision and Information Sciences; Univ. of Iowa

2003-10-15

383

Atmospheric peroxyacetyl nitrate (PAN): a global budget and source attribution  

NASA Astrophysics Data System (ADS)

Peroxyacetyl nitrate (PAN) formed in the atmospheric oxidation of non-methane volatile organic compounds (NMVOCs), is the principal tropospheric reservoir for nitrogen oxide radicals (NOx = NO + NO2). PAN enables the transport and release of NOx to the remote troposphere with major implications for the global distributions of ozone and OH, the main tropospheric oxidants. Simulation of PAN is a challenge for global models because of the dependence of PAN on vertical transport as well as complex and uncertain NMVOC sources and chemistry. Here we use an improved representation of NMVOCs in a global 3-D chemical transport model (GEOS-Chem) and show that it can simulate PAN observations from aircraft campaigns worldwide. The immediate carbonyl precursors for PAN formation include acetaldehyde (44% of the global source), methylglyoxal (30%), acetone (7%), and a suite of other isoprene and terpene oxidation products (19%). A diversity of NMVOC emissions is responsible for PAN formation globally including isoprene (37%) and alkanes (14%). Anthropogenic sources are dominant in the extratropical Northern Hemisphere outside the growing season. Open fires appear to play little role except at high northern latitudes in spring, although results are very sensitive to plume chemistry and plume rise. Lightning NOx is the dominant contributor to the observed PAN maximum in the free troposphere over the South Atlantic.

Fischer, E. V.; Jacob, D. J.; Yantosca, R. M.; Sulprizio, M. P.; Millet, D. B.; Mao, J.; Paulot, F.; Singh, H. B.; Roiger, A.-E.; Ries, L.; Talbot, R. W.; Dzepina, K.; Pandey Deolal, S.

2013-10-01

384

Impact of an improved Cuban emissions inventory on air quality simulations  

NASA Astrophysics Data System (ADS)

The energy sector in the Central America and Caribbean regions is primarily fossil fuel based and one of the major sources of air pollution in the region. In Cuba, energy production is responsible for 99% of SO2 emissions, 98% of NOX and 94% of CO, with emissions in 2000 of 588.59 Gg, 149.57 Gg and 536.42 Gg, respectively, according to the Cuban National Inventory - CNI. Electric power generation plants, the most important sub-sector, are highlighted as point sources of high emissions, in particular, SO2. Global inventories are shown to be inaccurate for Cuba. RETRO has non-zero data for just one cell, over the city of Havana. EDGAR has deficiencies in its geographical distribution, with no emissions over the city of Havana, and the distribution of emissions by sectors is unrealistic according to the CNI: for instance, in the case of SO2, it distributes emissions nearly equally between electricity generation and the remaining sectors, which is inaccurate. More importantly, emissions are overestimated, with the notable exception of SO2 and NMVOC. The most important reasons are the particularities of Cuba, including the extensive employ of fossil fuels with little refining and high sulfur content in energy production and industrial processes such as asphalt production, and the use of low efficiency technologies. This work presents an improved emissions inventory with CNI data and detailed emissions for all major power generation plants. The impact of this improvement was assessed through numerical air quality simulations of the transport and transformation of these emissions from a regional perspective, conducted with the CCATT-BRAMS 3D atmospheric chemical transport model, developed and maintained by INPE, Brazil. Boundary conditions were supplied by global model MOCAGE with chemistry scheme RELACS. Simulations with the new inventory were conducted with CATT-BRAMS using chemical mechanism RELACS, incorporated as part of this work, for two months (January and August) of 2008, and the differences found for the observed patterns for the dispersion of pollutants at a regional scale are discussed. The behavior of the model was evaluated through sensitivity tests.

Sanchez Gacita, M.; Alonso, M. F.; Longo, K. M.; de Freitas, S. R.

2010-12-01

385

Assessment of biomass open burning emissions in Indonesia and potential climate forcing impact  

NASA Astrophysics Data System (ADS)

This paper presents an emission inventory (EI) for biomass open burning (OB) sources including forest, agro-residue and municipal solid waste (MSW) in Indonesia for year 2007. The EI covered toxic air pollutants and greenhouse gases (GHGs) and was presented as annual and monthly average for every district, and further on a grid of 0.25° × 0.25°. A rigorous analysis of activity data and emission factor ranges was done to produce the low, best and high emission estimates for each species. Development of EI methodology for MSW OB which, to our best knowledge, has not been presented in detail in the literature was a focus of this paper. The best estimates of biomass OB emission of toxic air pollutants for the country, in Gg, were: 9.6 SO2; 98 NOx; 7411 CO; 335 NMVOC; 162 NH3; 439 PM10; 357 PM2.5; 24 BC; and 147 OC. The best emission estimates of GHGs, in Gg, were: 401 CH4, 57,247 CO2; and 3.6 N2O. The low and high values of the emission estimates for different species were found to range from -86% to +260% of the corresponding best estimates. Crop residue OB contributed more than 80% of the total biomass OB emissions, followed by forest fire of 2-12% (not including peat soil fire emission) and MSW (1-8%). An inter-annual active fires count for Indonesia showed relatively low values in 2007 which may be attributed to the high rainfall intensity under the influence of La Niña climate pattern in the year. Total estimated net climate forcing from OB in Indonesia was 110 (20 year horizon) and 73 (100 year horizon) Tg CO2 equivalents which is around 0.9-1.1% of that reported for the global biomass OB for both time horizons. The spatial distribution showed higher emissions in large urban areas in Java and Sumatra Island, while the monthly emissions indicated higher values during the dry months of August-October.

Permadi, Didin Agustian; Kim Oanh, Nguyen Thi

2013-10-01

386

Treatment of Waste Gases Contaminated with Odorous Sulfur Compounds  

Microsoft Academic Search

Due to their very low odor threshold value (ppbv range), high toxicity, and potential corrosive effect, the presence of volatile sulfur compounds in waste gases deserves special attention. These sulfur compounds mainly include hydrogen sulfide, dimethyl sulfide, dimethyl disulfide, meth-anethiol, carbon disulfide, and carbonyl sulfide. Contrary to natural emissions, anthropogenic emissions may contribute to local concentrations, strongly exceeding the odor

E. Smet; P. Lens; H. Van Langenhove

1998-01-01

387

Low volatile organic compound paints  

SciTech Connect

Increasingly stringent air emission standards in various states has dictated the elimination of engineering finishes which are derived from high volatile organic compound (VOC) paint chemistries. In July 1989, Allied-Signal, Inc., Kansas City Division, Kansas City, Missouri, voluntarily closed its paint facility, due to non-compliance with local air emission standards. The following details the materials selection and evaluations which led to current processing using low VOC paints, which permitted the Allied Signal, Inc., paint facility to achieve compliance and resume operations. 1 tab.

Martinez, F.E.

1991-01-01

388

CONTROL OF HYDROCARBON EMISSIONS FROM GASOLINE LOADING BY REFRIGERATION SYSTEMS  

EPA Science Inventory

The report gives results of a study of the capabilities of refrigeration systems, operated at three temperatures, to control volatile organic compound (VOC) emissions from truck loading at bulk gasoline terminals. Achievable VOC emission rates were calculated for refrigeration sy...

389

Air quality modelling over Bogota, Colombia: Combined techniques to estimate and evaluate emission inventories  

NASA Astrophysics Data System (ADS)

Two versions of the Emission Inventory (EI) are generated for the city of Bogota, Colombia. In the first version (EI-1), CORINAIR traffic emission factors (EFs) are used. In the second (EI-2), bulk traffic EFs calculated for the city, using in situ measurements and inverse modelling techniques at street level, are used. EI-2 traffic emissions are 5, 4 and 3 times bigger than the corresponding values in EI-1, for CO, PM10 and NMVOCs, respectively. The main goal of this study consists in evaluating the two versions of the EI when introduced into a mesoscale air quality model. The AOT (accumulated exposure over a threshold) index is calculated for comparison between observed and simulated concentrations of primary pollutants. Simulated concentrations using EI-2 are closer to the observed values. This comparison allows us to extract some conclusions of the methodology used to calculate the EFs. Local factors like the driving behavior, the altitude, vehicle technology and an aged fleet cannot be totally included and corrected in the standard methodologies, and seem to be more important than obtaining very detailed and precise information on the classification of the fleet or driving speeds. Under financially limited and fast changing situations, as in the case of many developing countries, a simple methodology to estimate bulk traffic EFs and to evaluate the EI, is of utmost importance. The use of combined techniques such as in situ measurements to estimate bulk traffic EFs, and further evaluation of the inventories with numerical models, proved to be a useful tool for this purpose.

Zárate, Erika; Carlos Belalcázar, Luis; Clappier, Alain; Manzi, Veronica; Van den Bergh, Hubert

390

40 CFR 59.625 - How do I select emission families?  

Code of Federal Regulations, 2013 CFR

...COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS Control of Evaporative Emissions From New and In-Use...How do I select emission families? (a) Divide your product line into families of portable fuel containers that...

2013-07-01

391

Fun with Compound Words  

NSDL National Science Digital Library

Identify and create compound words We will be studying compound words! First we need to find out what a compound word is, go to this website and read about compound words.What is a compound word Now that you have read about compound words lets do some fun activities to help us review. First go to Compound word flashcards, here you will ...

Huggins, Ms.

2012-04-12

392

Control VOC emissions  

SciTech Connect

Hydrocarbon processing industry (HPI) operators can select volatile organic compound (VOC) reduction programs more cost-effectively using these suggestions. New environmental regulations mandate reducing VOC emissions from process units because of: (1) their potential ozone-producing reactions in the atmosphere and (2) their perceived risk from exposure. Typical VOC sources are: fugitive equipment leaks; loading/transfer operations; wastewater treatment units; storage tanks. In almost all cases, fugitive equipment leaks are the largest source of hydrocarbons and air toxics. In locations with large uncontrolled marine or product-loading facilities, loading emissions may also be high. Costs for implementing these controls are based on the referenced EPA documents and are likely to vary for specific plant conditions and requirements. The challenge facing HPI operators is selecting the most applicable and cost-effective control systems for the specific emission sources. Balancing VOC-emission reductions with capital investment is a complex problem given the many potential paths to achieve compliance. However, these suggestions provide a framework to comprehensively investigate, develop, evaluate (both for capital costs and level of emission control), implement and review results when planning VOC control strategies.

Siegell, J.H. [Exxon Research and Engineering Co., Florham Park, NJ (United States)

1995-08-01

393

Cyclopropane compound  

US Patent & Trademark Office Database

A cyclopropane compound represented by the following formula (A) or a pharmaceutically acceptable salt thereof has orexin receptor antagonism, and therefore has a potencial of usefulness for the treatment of sleep disorder for which orexin receptor antagonism is effective, for example, insomnia: ##STR00001## wherein Q represents --CH-- or a nitrogen atom, R.sub.1a and R.sub.1b each independently represent a C.sub.1-6 alkyl group and the like, R.sub.1c represents a hydrogen atom and the like, R.sub.2a, R.sub.2b, R.sub.2c and R.sub.2d each independently represent a hydrogen atom, a halogen atom, a C.sub.1-6 alkyl group and the like, R.sub.3a, R.sub.3b and R.sub.3c each independently represent a hydrogen atom, a halogen atom and the like, and R.sub.3d represents a hydrogen atom and the like.

Terauchi; Taro (Tsukuba, JP); Takemura; Ayumi (Tsukuba, JP); Doko; Takashi (Tokyo, JP); Yoshida; Yu (Tsukuba, JP); Tanaka; Toshiaki (Tsukuba, JP); Sorimachi; Keiichi (Tsukuba, JP); Naoe; Yoshimitsu (Tsukuba, JP); Beuckmann; Carsten (Tsukuba, JP); Kazuta; Yuji (Tsukuba, JP)

2012-09-18

394

Gaseous Emissions from Plants in Controlled Environments.  

National Technical Information Service (NTIS)

Plant growth in a controlled ecological life support system may entail the build-up over extended time periods of phytotoxic concentrations of volatile organic compounds produced by the plants themselves. Ethylene is a prominent gaseous emission of plants...

D. T. Dubay

1988-01-01

395

Projections of air pollutant emissions and its impacts on regional air quality in China in 2020  

NASA Astrophysics Data System (ADS)

Anthropogenic emissions of air pollutants in China influence not only local and regional environments but also the global atmospheric environment; therefore, it is important to underst