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1

Characterizing reduced sulfur compounds and non-methane volatile organic compounds emissions from a swine concentrated animal feeding operation  

Microsoft Academic Search

Reduced sulfur compounds (RSCs) and non-methane volatile organic compounds (NMVOCs) emissions from concentrated animal feeding operations (CAFOs) have become a potential environmental and human health concern. Both RSCs and NMVOCs contribute to odor. In addition, RSCs also have the potential to form fine particulate matter (PMfine) and NMVOCs the potential to form ozone. Measurements of RSCs and NMVOCs emissions were

Ian Cooper Rumsey

2010-01-01

2

Impacts of NMVOC emissions on human health in European countries for 2000–2010: Use of sector-specific substance profiles  

NASA Astrophysics Data System (ADS)

Non-methane volatile organic compounds (NMVOC) are known to cause damages to human health via two main pathways, viz. the direct toxic effects exerted by certain substances (termed here human toxicity) and their indirect effects related to photochemical ozone formation (POF). To comprehensively assess the damages at national level and thus define adequate air pollution abatement policies, substance breakdowns are needed. However, these are not readily available as total NMVOC emissions are only reported at sector level. In this study, we developed a reproducible methodology that combines available speciation profiles, i.e. distributions of substances emitted per type of sources, and sectoral NMVOC information to reach country-specific, substance-specific emission profiles. Annual emission inventories, including 270 single substances and 52 unrefined groups of substances, were determined for 31 European countries within the period 2000–2010. Using life cycle impact assessment methods for POF and human toxicity, impacts on human health were quantified. The results indicated that a strong linear correlation exists between POF impacts and the total NMVOC emissions, suggesting that air pollution abatement policies could use total NMVOC emissions as a proxy for reducing these impacts. Despite underlying uncertainties, the results also demonstrated that the POF impacts from NMVOC are negligible compared to their direct toxic impacts. The analysis of the results revealed that the toxic impacts (i) are caused by few substances, such as formaldehyde, acrolein and furan, (ii) primarily stem from transportation sectors and from residential sources, and (iii) are found not to correlate with total NMVOC emissions. Our findings therefore suggest the need for supporting air pollution abatement strategies with comprehensive impact assessments, which, in addition to complementing emission- and concentration-based indicators, should allow identifying country-specific improvement potentials at substance and sector levels.

Laurent, Alexis; Hauschild, Michael Z.

2014-03-01

3

NMVOCs speciated emissions from mobile sources and their effect on air quality and human health in the metropolitan area of Buenos Aires, Argentina  

NASA Astrophysics Data System (ADS)

Since 2007, more than half of the world's population live in urban areas. Urban atmospheres are dominated by pollutants associated with vehicular emissions. Transport emissions are an important source of non-methane volatile organic compounds (NMVOCs) emissions, species of high interest because of their negative health effects and their contribution to the formation of secondary pollutants responsible for photochemical smog. NMVOCs emissions are generally not very well represented in emission inventories and their speciation presents a high level of uncertainty. In general, emissions from South American countries are still quite unknown for the international community, and usually present a high degree of uncertainty due to the lack of available data to compile emission inventories. Within the Inter-American Institute for Global Change Research (IAI, www.iai.int) projects, UMESAM (Urban Mobile Emissions in South American Megacities) and SAEMC (South American Emissions, Megacities and Climate, http://saemc.cmm.uchile.cl/), the effort was made to compute on-road transport emission inventories for South American megacities, namely Bogota, Buenos Aires, Lima, Sao Paulo and Santiago de Chile, considering megacities as urban agglomerations with more than 5 million inhabitants. The present work is a continuation of these projects, with the aim to extend the calculated NMVOCs emissions inventory into the individual species required by CTMs. The on-road mobile sector of the metropolitan area of Buenos Aires (MABA), Argentina, accounted for 70 Gg of NMVOCs emissions for 2006, without considering two-wheelers. Gasoline light-duty vehicles were responsible for 64% of NMVOCs emissions, followed by compressed natural gas (CNG) light-duty vehicles (22%), diesel heavy-duty vehicles (11%) and diesel light-duty vehicles (7%). NMVOCs emissions were speciated according to fuel and technology, employing the European COPERT (Ntziachristos & Samaras, 2000) VOCs speciation scheme for gasoline and diesel vehicles and the USEPA SPECIATE (Simon et al., 2010) profile for CNG vehicles. NMVOCs emissions were composed of 31% aromatic compounds, 29% linear alkanes, 20% olefins, 12% ramified alkanes, 7% aldehydes and negligible contributions from cycloalkanes, ketones, Polycyclic Aromatic Hydrocarbons (PAHs) and other NMVOCs. Aromatic compounds dominated gasoline light-duty vehicles' emissions (~45%), while linear alkanes those of CNG light-duty vehicles (~80%). Aldehydes' contributions increased for diesel light and heavy-duty vehicles. VOCs speciation schemes for transport emissions were collected from the literature from Europe, USA, Asia, Oceania and Latin America with the aim to account for the associated uncertainty by compound for each fuel and technology type. The resulting individual NMVOCs emissions were used to calculate the corresponding tropospheric ozone formation (Carter, 1994), as well as the human toxicity potential in terms of 1.4 dichlorobenzene. Olefins and aromatic compounds in terms of species, and gasoline in terms of fuels, were found to impose the highest risk in urban environments regarding air quality and human health.

D'Angiola, Ariela; Dawidowski, Laura; Gomez, Dario; Granier, Claire

2014-05-01

4

Chemical speciation and source apportionment of Non-Methane Volatile Organic Compounds (NMVOCs) in a Middle Eastern country  

NASA Astrophysics Data System (ADS)

NMVOCs, emitted from various sources, are of particular interest since they contribute to the formation of tropospheric ozone, PAN and secondary organic aerosols resulting in negative impacts on human health, climate and on the environment. To identify abatement measures, a profound knowledge of emission sources and their composition is a prerequisite. Air pollution in the Middle East region remains difficult to assess and understand because of a lack of ground-based measurements and the limited information on NMVOC chemical speciation and source apportionment. Based on a large database of NMVOC observations obtained in Beirut, the capital of Lebanon (a developing country in the Middle East region, located in Western Asia on the eastern shore of the Mediterranean Sea), the overall objective of this work is to apportion the sources of NMVOCs encountered in Lebanon. First, source profiles were determined with field measurements close to the main potential emitters namely the road transport, gasoline vapour, power generation and solvent uses. The results obtained are compared to other studies held in other regions and are used to assess the emission inventory developed for Lebanon. Secondly, two intensive field campaigns were held in a receptor site in Beirut during summer 2011 and winter 2012 in order to obtain a large time resolved dataset. The PMF analysis of this dataset was applied to apportion anthropogenic sources in this area. In both seasons, combustion (road transport and power generation) and gasoline evaporation, especially in winter, were the main sources contributing to the NMVOCs in Beirut. The results will support model implementation especially by completing the emission inventory established for the year 2010 by Waked et al. 2012 according to the EEA/EMEP guidelines because of the lack of Lebanon-specific emission factor.

Salameh, Therese; Sauvage, Stéphane; Afif, Charbel; Borbon, Agnès; Locoge, Nadine

2014-05-01

5

Net radiative forcing responses to regional CO and NMVOC reductions  

NASA Astrophysics Data System (ADS)

Recent studies suggest that short-lived pollutants and their precursors be considered in near-term climate mitigation strategies, in addition to national air quality programs, but their associated forcings vary based on the region of emissions. Here we quantify the net radiative forcing (RF) impacts of regional anthropogenic carbon monoxide (CO) and non-methane volatile organic compound (NMVOC) emissions due to changes in the tropospheric concentrations of ozone (O3), methane (CH4), and aerosols (carbonaceous and sulfate), to inform future coordinated actions addressing air quality and climate forcing. We present the RF from CO and NMVOC emission reductions from 10 regions (North America, South America, Europe, Former Soviet Union, Southern Africa, India, East Asia, Southeast Asia, Australia and New Zealand, and Middle East and Northern Africa). The global chemical transport model MOZART-4 is used to simulate tropospheric concentration changes, using the IPCC AR5 Representative Concentration Pathway 8.5 (RCP 8.5) emissions inventory for 2005 and global meteorology from the Goddard Earth Observing System Model, version 5 (GEOS-5) for the years 2004-2005. We utilize the NOAA Geophysical Fluid Dynamics Laboratory standalone radiative transfer model to calculate the stratospheric-adjusted net RF for each regional CO and NMVOC reduction, relative to the base. We find that global annual net RF per unit change in emissions ranges from -0.115 to -0.131 mW m-2 / Tg CO for CO reductions, and -0.0035 to -0.436 mW m-2 / Tg C for NMVOC reductions, with the regions in the tropics providing the greatest improvements (Middle East, Southeast Asia, and India CO reductions, and Middle East, Africa, and India NMVOC reductions). The net RF distributions for the CO and NMVOC reductions show widespread cooling across the northern and southern hemispheres corresponding to the patterns of O3 and CH4 decreases, and localized positive and negative net RFs due to increases and decreases in aerosols. The strongest annual net RF impacts occur within the tropics (28 S - 28 N) followed by the northern mid-latitudes (28 N - 60 N), independent of reduction region for CO, and for many of the NMVOC regional reductions. The small variation in RF per unit emissions for CO, among world regions (coefficient of variation = 0.045), suggests that the error would be small in using a uniform global warming potential (GWP), and in possibly including CO in international climate agreements. In contrast, NMVOCs show greater variability among the reduction regions (coefficient of variation = 0.48), suggesting that regionally-specific GWPs may be more appropriate for NMVOCs.

Fry, M. M.; Schwarzkopf, M. D.; Adelman, Z.; Naik, V.; West, J.

2012-12-01

6

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

7

Mapping Asian anthropogenic emissions of non-methane volatile organic compounds to multiple chemical mechanisms  

NASA Astrophysics Data System (ADS)

An accurate speciation mapping of non-methane volatile organic compounds (NMVOC) emissions has an important impact on the performance of chemical transport models (CTMs) in simulating ozone mixing ratios and secondary organic aerosols. Taking the INTEX-B Asian NMVOC emission inventory as the case, we developed an improved speciation framework to generate model-ready anthropogenic NMVOC emissions for various gas-phase chemical mechanisms commonly used in CTMs in this work, by using an explicit assignment approach and updated NMVOC profiles. NMVOC profiles were selected and aggregated from a wide range of new measurements and the SPECIATE database v.4.2. To reduce potential uncertainty from individual measurements, composite profiles were developed by grouping and averaging source profiles from the same category. The fractions of oxygenated volatile organic compounds (OVOC) were corrected during the compositing process for those profiles which used improper sampling and analyzing methods. Emissions of individual species were then lumped into species in different chemical mechanisms used in CTMs by applying mechanism-dependent species mapping tables, which overcomes the weakness of inaccurate mapping in previous studies. Emission estimates for individual NMVOC species differ between one and three orders of magnitude for some species when different sets of profiles are used, indicating that source profile is the most important source of uncertainties of individual species emissions. However, those differences are diminished in lumped species as a result of the lumping in the chemical mechanisms. Gridded emissions for eight chemical mechanisms at 30 min × 30 min resolution as well as the auxiliary data are available at http://mic.greenresource.cn/intex-b2006. The framework proposed in this work can be also used to develop speciated NMVOC emissions for other regions.

Li, M.; Zhang, Q.; Streets, D. G.; He, K. B.; Cheng, Y. F.; Emmons, L. K.; Huo, H.; Kang, S. C.; Lu, Z.; Shao, M.; Su, H.; Yu, X.; Zhang, Y.

2014-06-01

8

Air quality and radiative forcing impacts of anthropogenic volatile organic compound emissions from ten world regions  

NASA Astrophysics Data System (ADS)

Non-methane volatile organic compounds (NMVOCs) influence air quality and global climate change through their effects on secondary air pollutants and climate forcers. Here we simulate the air quality and radiative forcing (RF) impacts of changes in ozone, methane, and sulfate from halving anthropogenic NMVOC emissions globally and from 10 regions individually, using a global chemical transport model and a standalone radiative transfer model. Halving global NMVOC emissions decreases global annual average tropospheric methane and ozone by 36.6 ppbv and 3.3 Tg, respectively, and surface ozone by 0.67 ppbv. All regional reductions slow the production of peroxyacetyl nitrate (PAN), resulting in regional to intercontinental PAN decreases and regional NOx increases. These NOx increases drive tropospheric ozone increases nearby or downwind of source regions in the Southern Hemisphere (South America, Southeast Asia, Africa, and Australia). Some regions' NMVOC emissions contribute importantly to air pollution in other regions, such as East Asia, the Middle East, and Europe, whose impact on US surface ozone is 43%, 34%, and 34% of North America's impact. Global and regional NMVOC reductions produce widespread negative net RFs (cooling) across both hemispheres from tropospheric ozone and methane decreases, and regional warming and cooling from changes in tropospheric ozone and sulfate (via several oxidation pathways). The 100 yr and 20 yr global warming potentials (GWP100, GWP20) are 2.36 and 5.83 for the global reduction, and 0.079 to 6.05 and -1.13 to 18.9 among the 10 regions. The NMVOC RF and GWP estimates are generally lower than previously modeled estimates, due to the greater NMVOC/NOx emissions ratios simulated, which result in less sensitivity to NMVOC emissions changes and smaller global O3 burden responses, in addition to differences in the representation of NMVOCs and oxidation chemistry among models. Accounting for a fuller set of RF contributions may change the relative magnitude of each region's impacts. The large variability in the RF and GWP of NMVOCs among regions suggest that regionally specific metrics may be necessary to include NMVOCs in multi-gas climate trading schemes.

Fry, M. M.; Schwarzkopf, M. D.; Adelman, Z.; West, J. J.

2014-01-01

9

Historical industrial emissions of non-methane volatile organic compounds in China for the period of 1980–2010  

NASA Astrophysics Data System (ADS)

This paper presents a new classification of industrial sector on basis of a source-tracing method for the historical industrial emissions of non-methane volatile organic compounds (NMVOCs). The industrial sources were divided into four major source categories: production of NMVOCs, storage and transport, industrial processes using NMVOCs as raw materials, and processes using NMVOCs-containing products. Multiyear emission inventories of NMVOCs from industrial sources were established for the period of 1980–2010 in China, covering 98 contributing industrial sources. The inventories were developed by the emission factor method, and further gridded at a spatial resolution of 50 km × 50 km based on GIS methodology, using population data as spatial surrogate. The result showed that China's industrial NMVOCs emissions had increased by 11.6 times at an average annual rate of 8.5% from 1.15 Tg in 1980 to 13.35 Tg in 2010. The four major source categories generated 19.6% (2.63 Tg, production of NMVOCs), 9.6% (1.295 Tg, storage and transport), 13.2% (1.769 Tg, industrial processes using NMVOCs as raw materials), and 57.4% (7.662 Tg, processes using NMVOCs-containing products) of the total emissions from China in 2010. Moreover, the top four industrial emissions sources were oil refinery, architectural decoration, machinery equipment and printing, accounted for 48.3% all together. With respect to the spatial distribution, the emissions mostly occurred in the eastern, northern and southern parts of China, all being much higher than that in the western part. The top four emission provinces were Shandong, Jiangsu, Guangdong, and Zhejiang, accounting for 38.3% of the national emissions. As for the past 30 years, the national industrial NMVOCs emissions increased year-by-year, being in pace with the accelerated industrialization process and the sharp economic growth, especially the rapid expansion of the high-emission industries. Particularly, the oil refinery, product oil and solvent distribution, architectural decoration, and mechanical equipment manufacture became the four largest contributors, accounting for 15.9–34.3%, 6.5–10.2%, 7–8%, and 6–7% of national industrial NMVOCs.

Qiu, Kaiqiong; Yang, Lixian; Lin, Junmin; Wang, Peitao; Yang, Yi; Ye, Daiqi; Wang, Liming

2014-04-01

10

Characterizing reduced sulfur compounds and non-methane volatile organic compounds emissions from a swine concentrated animal feeding operation  

NASA Astrophysics Data System (ADS)

Reduced sulfur compounds (RSCs) and non-methane volatile organic compounds (NMVOCs) emissions from concentrated animal feeding operations (CAFOs) have become a potential environmental and human health concern. Both RSCs and NMVOCs contribute to odor. In addition, RSCs also have the potential to form fine particulate matter (PMfine) and NMVOCs the potential to form ozone. Measurements of RSCs and NMVOCs emissions were made from both an anaerobic lagoon and barn at a swine CAFO in North Carolina. Emission measurements were made over all four seasonal periods. In each seasonal period, measurements were made from both the anaerobic lagoon and barn for ˜1 week. RSC and NMVOCs samples were collected using passivated canisters. Nine to eleven canister samples were taken from both the lagoon and barn over each sampling period. The canisters were analyzed ex-situ using gas chromatography flame ionization detection (GC-FID). Hydrogen sulfide (H2S) measurements were made in-situ using a pulsed fluorescence H2S/SO2 analyzer. During sampling, measurements of meteorological and physiochemical parameters were made. H2S had the largest RSC flux, with an overall average lagoon flux of 1.33 mug m-2 min-1. The two main RSCs identified by the GC-FID, dimethyl sulfide (DMS) and dimethyl disulfide (DMDS), had overall average lagoon fluxes an order of magnitude lower, 0.12 and 0.09 mug m-2 min-1, respectively. Twelve significant NMVOCs were identified in lagoon samples (ethanol, 2-ethyl-1-hexanol, methanol, acetaldehyde, decanal, heptanal, hexanal, nonanal, octanal, acetone, methyl ethyl ketone, and 4-methylphenol). The overall average fluxes for these NMVOCs, ranged from 0.08 mug m-2 min-1 (4-methylphenol) to 2.11 mug m-2 min-1 (acetone). Seasonal H2S barn concentrations ranged from 72-631 ppb. DMS and DMDS seasonal concentrations were 2-3 orders of magnitude lower. There were six significant NMVOCs identified in barn samples (methanol, ethanol, acetone 2-3 butanedione, acetaldehyde and 4-methylphenol). Their overall average NMVOCs concentrations ranged from 2.87 ppb (4-methylphenol) to 16.21 ppb (ethanol). The overall average barn normalized emissions were 3.3 g day-1 AU-1 (AU (animal unit) = 500 kg) for H2S, 0.018 g day-1 AU-1 for DMS and 0.037 g day -1 AU-1 for DMDS. Normalized overall average NMVOC emissions ranged from 0.45 g day-1 AU-1 for ethanol to 0.16 g day-1 AU-1 for acetaldehyde. Barn H2S concentrations were generally one to two orders of magnitude above their odor thresholds. DMDS concentrations also regularly exceeded the lower limit of an odor threshold. Four NMVOCs (2-3 butanedione, decanal, 4-methylphenol and nonanal) had barn concentrations exceeding an odor threshold. Using overall average lagoon and barn emissions, the emissions from swine CAFOs in North Carolina were estimated. H2S had the largest RSC emission with an estimated North Carolina emission of 1.46 million kg yr -1, which was ˜21% of total North Carolina H2S emissions. Ethanol was the NMVOC with the largest North Carolina emission with an emission of 206,367 kg yr-1.

Rumsey, Ian Cooper

11

Characterizing non-methane volatile organic compounds emissions from a swine concentrated animal feeding operation  

NASA Astrophysics Data System (ADS)

Emissions of non-methane volatile organic compounds (NMVOCs) were determined from a swine concentrated animal feeding operation (CAFO) in North Carolina. NMVOCs were measured in air samples collected in SUMMA and fused-silica lined (FSL) canisters and were analyzed using a gas chromatography flame ionization detection (GC-FID) system. Measurements were made from both an anaerobic lagoon and barn in each of the four seasonal sampling periods during the period June 2007 through April 2008. In each sampling period, nine to eleven canister samples were taken from both the anaerobic lagoon and barn over a minimum of four different days during a period of ˜1 week. Measurements of meteorological and physiochemical parameters were also made during the sampling period. In lagoon samples, six NMVOCs were identified that had significantly larger emissions in comparison to other NMVOCs. This included three alcohols (ethanol, 2-ethyl-1-hexanol, and methanol), two ketones (acetone and methyl ethyl ketone (MEK)) and an aldehyde (acetaldehyde). The overall average fluxes for these NMVOCs, ranged from 0.18 ?g m -2 min -1 for 2-ethyl-1-hexanol to 2.11 ?g m -2 min -1 for acetone, with seasonal fluxes highest in the summer for four (acetone, acetaldehyde, 2-ethyl-1-hexanol and MEK) of the six compounds In barn samples, there were six NMVOCs that had significantly larger concentrations and emissions in comparison to other NMVOCs. These consisted of two alcohols (methanol and ethanol), an aldehyde (acetaldehyde), two ketones (acetone and 2,3-butanedione), and a phenol (4-methylphenol). Overall average barn concentration ranged from 2.87 ppb for 4-methylphenol to 16.12 ppb for ethanol. Overall average normalized barn emission rates ranged from 0.10 g day -1 AU -1 (1 AU (animal unit) = 500 kg of live animal weight) for acetaldehyde to 0.45 g day -1 AU -1 for ethanol. The NMVOCs, 4-methylphenol and 2,3-butanedione, which have low odor thresholds (odor thresholds = 1.86 ppb and 0.068-0.264 ppb for 4-methylphenol, and = 4.37 ppb and 1.42-7.39 ppb for 2-3-butanedione) and an offensive odor were identified in canister samples. Both 4-methylphenol and 2,3-butanedione barn concentrations exceeded their odor thresholds frequently. HAPs were identified in lagoon samples (methanol, acetaldehyde and MEK) and barn samples (methanol, acetaldehyde and 4-methylphenol) that were also classified as NMVOCs with significantly larger lagoon and barn emissions in comparison with other NMVOCs. The overall average lagoon fluxes and overall average normalized barn emissions for NMVOCs reported in this paper were used to estimate their North Carolina swine CAFO emissions. Of the NMVOCs, ethanol was estimated to have the largest North Carolina swine CAFO emission at 206,367 kg yr -1. The barns were found to have higher emissions than the lagoons for all NMVOCs, contributing between 68.6 to ˜100% of individual compounds estimated North Carolina swine CAFO emissions.

Rumsey, Ian C.; Aneja, Viney P.; Lonneman, William A.

2012-02-01

12

Characterizing Non-Methane Volatile Organic Compounds Emissions from a Swine Concentrated Animal Feeding Operation  

NASA Astrophysics Data System (ADS)

The emission of NMVOCs from swine concentrated animal feeding operations (CAFOs) in North Carolina is of concern, due to their contribution to odor. In addition, of the 188 listed hazardous air pollutants (HAPs), 162 are classified as NMVOCs. NMVOCs emissions were determined over four seasonal sampling periods from an anaerobic lagoon and barn at a swine CAFO in North Carolina. Sampling was conducted during the period June 2007 through April 2008. Air samples were collected using SUMMA and fused-silca lined (FSL) canisters and were analyzed for NMVOCs using a gas chromatography flame ionization detection (GC-FID) system. Nine to eleven canister samples were collected from both the anaerobic lagoon and the barn over a ~1 week sampling period, with samples collected on a minimum of four different days. Measurements of meteorological and physiochemical parameters were made during the lagoon and barn sampling. Six NMVOCs (acetone, acetaldehyde, ethanol, 2-ethyl-1-hexanol, methanol and methyl ethyl ketone (MEK)) were identified in lagoon samples, that were classified as having significantly larger emissions in comparison to other NMVOCs. Overall average lagoon fluxes of these NMVOCs ranged from 0.18 ug m-2 min-1 for 2-ethyl-1-hexanol to 2.11 ug m-2 min-1 for acetone. In barn samples there were also six NMVOCs (acetaldehyde, acetone, 2,3-butanedione, ethanol, methanol and 4-methylphenol) that were classified as having significantly larger emissions in comparison to other compounds. Overall average concentrations for these six compounds ranged from 2.87 ppb for 4-methylphenol to 16.12 ppb for ethanol. The overall average normalized emissions ranged from 0.10 g day-1 AU-1 (AU = one animal unit, representing 500 kg of live animal weight) for acetaldehyde to 0.45 g day-1 AU-1 for ethanol. Eight odorous compounds were identified in lagoon and barn samples. These were 2,3-butanedione, decanal, ethylbenzene, heptanal, hexanal, 4-methylphenol, nonanal, and octanal. Of the eight compounds, 4-methylphenol and 2,3-butanedione were the compounds that exceeded their odor thresholds the most frequently. Four HAPs were identified in lagoon and barn samples that were also classified as having significantly larger lagoon and barn emissions in comparison to other NMVOCs. These were methanol, 4-methylphenol, acetaldehyde and MEK. The overall average lagoon fluxes and the overall average normalized barn emissions for the reported NMVOCs were used to estimate their swine CAFO emissions for North Carolina. Three NMVOCs were estimated to have considerably larger North Carolina swine CAFO emissions than the other NMVOCs. These were ethanol, acetone and methanol, with emissions of 206,367 kg yr-1, 134,765 kg yr-1 and 134,732 kg yr-1, respectively. The majority of individual compounds' North Carolina swine CAFO emissions were from barns, with barns contributing between 68.6% to ~ 100%.

Aneja, V. P.; Rumsey, I. C.; Lonneman, W. A.

2011-12-01

13

Mapping Asian anthropogenic emissions of non-methane volatile organic compounds to multiple chemical mechanisms  

NASA Astrophysics Data System (ADS)

An accurate speciation mapping of non-methane volatile organic compounds (NMVOC) emissions has an important impact on the performance of chemical transport models (CTMs) in simulating ozone mixing ratios and secondary organic aerosols. In this work, we developed an improved speciation framework to generate model-ready anthropogenic Asian NMVOC emissions for various gas-phase chemical mechanisms commonly used in CTMs by using an explicit assignment approach and updated NMVOC profiles, based on the total NMVOC emissions in the INTEX-B Asian inventory for the year 2006. NMVOC profiles were selected and aggregated from a wide range of new measurements and the SPECIATE database. To reduce potential uncertainty from individual measurements, composite profiles were developed by grouping and averaging source profiles from the same category. The fractions of oxygenated volatile organic compounds (OVOC) were corrected during the compositing process for those profiles which used improper sampling and analyzing methods. Emissions of individual species were then lumped into species in different chemical mechanisms used in CTMs by applying mechanism-dependent species mapping tables, which overcomes the weakness of inaccurate mapping in previous studies. Gridded emissions for eight chemical mechanisms are developed at 30 min × 30 min resolution using various spatial proxies and are provided through the website: http://mic.greenresource.cn/intex-b2006. Emission estimates for individual NMVOC species differ between one and three orders of magnitude for some species when different sets of profiles are used, indicating that source profile is the most important source of uncertainties of individual species emissions. However, those differences are diminished in lumped species as a result of the lumping in the chemical mechanisms.

Li, M.; Zhang, Q.; Streets, D. G.; He, K. B.; Cheng, Y. F.; Emmons, L. K.; Huo, H.; Kang, S. C.; Lu, Z.; Shao, M.; Su, H.; Yu, X.; Zhang, Y.

2013-12-01

14

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

15

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

16

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

17

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

18

Estimating the biogenic emissions of non-methane volatile organic compounds from the North Western Mediterranean vegetation of Catalonia, Spain.  

PubMed

An estimation of the magnitude of non-methane volatile organic compounds (NMVOCs) emitted by vegetation in Catalonia (NE of the Iberian Peninsula, Spain), in addition to their superficial and temporal distribution, is presented for policy and scientific (photochemical modelling) purposes. It was developed for the year 2000, for different time resolutions (hourly, daily, monthly and annual) and using a high-resolution land-use map (1-km2 squared cells). Several meteorological surface stations provided air temperature and solar radiation data. An adjusted mathematical emission model taking account of Catalonia's conditions was built into a geographic information system (GIS) software. This estimation uses the latest information, mainly relating to: (1) emission factors; (2) better knowledge of the composition of Catalonia's forest cover; and (3) better knowledge of the particular emission behaviour of some Mediterranean vegetal species. Results depict an annual cycle with increasing values in the March-April period with the highest emissions in July-August, followed by a decrease in October-November. Annual biogenic NMVOCs emissions reach 46.9 kt, with monoterpenes the most abundant species (24.7 kt), followed by other biogenic volatile organic compounds (e.g. alcohols, aldehydes and acetone) (16.3 kt), and isoprene (5.9 kt). These compounds signify 52%, 35% and 13%, respectively, of total emission estimates. Peak hourly total emission for a winter day could be less than 10% of the corresponding value for a summer day. PMID:15262170

Parra, R; Gassó, S; Baldasano, J M

2004-08-15

19

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

20

Chemical nonlinearities in relating intercontinental ozone pollution to anthropogenic emissions  

NASA Astrophysics Data System (ADS)

Model studies typically estimate intercontinental influence on surface ozone by perturbing emissions from a source continent and diagnosing the ozone response in the receptor continent. Since the response to perturbations is non-linear due to chemistry, conclusions drawn from different studies may depend on the magnitude of the applied perturbation. We investigate this issue for intercontinental transport between North America, Europe, and Asia with sensitivity simulations in three global chemical transport models. In each region, we decrease anthropogenic emissions of NOx and nonmethane volatile organic compounds (NMVOCs) by 20% and 100%. We find strong nonlinearity in the response to NOx perturbations outside summer, reflecting transitions in the chemical regime for ozone production. In contrast, we find no significant nonlinearity to NOx perturbations in summer or to NMVOC perturbations year-round. The relative benefit of decreasing NOx vs. NMVOC from current levels to abate intercontinental pollution increases with the magnitude of emission reductions.

Wu, Shiliang; Duncan, Bryan N.; Jacob, Daniel J.; Fiore, Arlene M.; Wild, Oliver

2009-03-01

21

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

22

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

Microsoft Academic Search

Global inventories of anthropogenic emissions of oxides of nitrogen (NOâ) 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 NOâ inventory

C. M. Benkovitz; M. A. Mubaraki

1997-01-01

23

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

24

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

Microsoft Academic Search

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 \\

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

2004-01-01

25

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

Microsoft Academic Search

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 \\

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

2005-01-01

26

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

27

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

28

Estimating the biogenic emissions of non-methane volatile organic compounds from the North Western Mediterranean vegetation of Catalonia, Spain  

Microsoft Academic Search

An estimation of the magnitude of non-methane volatile organic compounds (NMVOCs) emitted by vegetation in Catalonia (NE of the Iberian Peninsula, Spain), in addition to their superficial and temporal distribution, is presented for policy and scientific (photochemical modelling) purposes. It was developed for the year 2000, for different time resolutions (hourly, daily, monthly and annual) and using a high-resolution land-use

R. Parra; S. Gassó; J. M. Baldasano

2004-01-01

29

Transport and distribution of primary and secondary nonmethane volatile organic compounds in east Asia under continental outflow conditions  

Microsoft Academic Search

A regional scale three-dimensional atmospheric chemistry model is used to study the transport and chemistry of nonmethane volatile organic compounds (NMVOCs) in east Asia. A springtime episode during the month of May 1987 is investigated. The emission estimates of ethane, propane, and ethene from our calculations in east Asia are ~1.6, ~1.3, and ~5.2 Tg C\\/yr, respectively. The model calculated

Mahesh J. Phadnis; Gregory R. Carmichael

2000-01-01

30

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....

31

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....

32

EMISSION OF VOLATILE COMPOUNDS BY SEEDS UNDER DIFFERENT ENVIRONMENTAL CONDITIONS  

EPA Science Inventory

Small mammals locate buried wet seeds more efficiently than buried dry seeds. This may be attributable to emission of volatile compounds by the seeds. To test this hypothesis I measured emission of volatile compounds from seeds of three plant species (Pinus contorta, Purshia tr...

33

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

34

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

35

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...

36

Biological aspects of constructing volatile organic compound emission inventories  

Microsoft Academic Search

The: emission of volatile organic compounds (VOCs) from vegetation is subject to numerous biological controls. Past inventories have relied heavily on empirical models which are limited in their ability to simulate the response of organisms to short- and long-term changes in their growth environment. In this review we consider the principal biochemical, physiological and ecological controls over VOC emission with

Ray Fall; Mt Lerdau; Td Sharkey

1995-01-01

37

Characterization of total volatile organic compound emissions from paints  

Microsoft Academic Search

Recently, Homeswest in Western Australia and Murdoch University developed a project to construct low allergen houses (LAH) in a newly developed suburb. All potential volatile organic compound (VOC) emission materials used in LAH are required to be measured before the construction of LAH, to ensure they are low VOCs emission materials. To protect people sensitive to exposure to VOCs it

H. Guo; F. Murray

2000-01-01

38

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

39

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

40

Characterization of total volatile organic compound emissions from paints  

Microsoft Academic Search

Recently, Homeswest in Western Australia and Murdoch University developed a project to construct low allergen houses (LAH)\\u000a in a newly developed suburb. All potential volatile organic compound (VOC) emission materials used in LAH are required to\\u000a be measured before the construction of LAH, to ensure they are low VOCs emission materials. To protect people sensitive to\\u000a exposure to VOCs it

H. Guo; F. Murray

2000-01-01

41

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

42

A global model of natural volatile organic compound emissions  

Microsoft Academic Search

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

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

1995-01-01

43

Volatile organic compound (VOC) emissions from soil and litter samples  

Microsoft Academic Search

The production of nonmethane volatile organic compounds (VOCs) by soil microbes is likely to have an important influence on soil ecology and terrestrial biogeochemistry. However, soil VOC production has received relatively little attention, and we do not know how the emissions of microbially-produced VOCs vary across soil and litter types. We collected 40 root-free soil and litter samples from a

Jonathan W. Leff; Noah Fierer

2008-01-01

44

How do emission patterns in megacities affect regional air pollution?  

NASA Astrophysics Data System (ADS)

Megacities around the world show distinctly different emission patterns in terms of absolute amounts and emission ratios of individual chemical compounds due to varying socio-economic developments and technological standards. The emission patterns influence the chemical reactivity of the urban pollution plume, and hence determine air quality in and around megacity areas. In this study, which is part of the European project CITYZEN (megaCITY - Zoom for the ENvironment), the effects of emission changes in four selected megacity areas on air pollution were investigated: BeNeLux (BNL), Istanbul (IST), Pearl River Delta (PRD) and Sao Paulo (SAP). The study aims at answering the question: how would air pollution in megacity X change if it had the same urban emissions per capita as megacity Y? Model simulations with the global chemistry climate model ECHAM5-MOZ were carried out for the year 2001 using a resolution of about 2 degrees in the horizontal and of 31 levels (surface to 10 hPa) in the vertical. The model was driven by meteorological input data from the ECMWF ERA Interim reanalysis. Emissions were taken from the gridded global ACCMIP emission inventory recently established for use in chemistry-climate simulations in connection to the IPCC-AR5 assessments (Lamarque et al. 2010). We carried out sensitivity simulations where emission patterns from each of the megacity areas were replaced by those from all others. This was done on the basis of the per capita emissions for each species and sector averaged over the respective region. Total per capita CO and NMVOC emissions are highest in PRD and lowest in SAP while total per capita NOx emissions are highest in BNL and lowest in SAP. There are strong differences in the relative contribution of the urban sectors to total emissions of individual compounds. As a result, each of the four megacity areas exhibits a very characteristic NMVOC speciation profile which determines the NMVOC-related photochemical ozone (O_3) creation potential. Compared to the emissions used in the reference simulation, changing per capita urban emissions in BNL into those of IST or SAP will lead to reduction in total megacity emissions of CO and NOx by between 40 to 80% and of between 5 to 20% for NMVOC. When the per capita emissions for PRD are applied, only NOx decreases (by 50%) while CO and NMVOC increase by between 20 and 40%. Similar changes occur when the emissions are interchanged in the other three regions. Annual mean ambient O_3 concentrations in the entire BNL megacity domain are elevated by 3 to 8 ppb in all sensitivity runs and a significant effect is also found outside the main megacity area. In the IST and PRD megacity areas, O_3 levels increase or decrease by 1 to 5 ppb when the per capita emissions from the other regions are used. For the SAP megacity area, all scenarios lead to a reduction of annual mean O_3 levels by more than 4 ppb in the north-western section of the domain while increases up to 3 ppb are predicted for some southern regions. We will also present an analysis of changes in the photochemical regimes related to altered emission patterns. The study can contribute directly to the development of air pollution abatement strategies.

Heil, A.; Richter, C.; Schroeder, S.; Schultz, M. G.

2010-12-01

45

VOC (VOLATILE ORGANIC COMPOUND EMISSION FACTORS FOR THE NAPAP (NATIONAL ACID PRECIPITATION ASSESSMENT PROGRAM) EMISSION INVENTORY  

EPA Science Inventory

The report gives results of the generation of emission factors for volatile organic compound (VOC) emissions for a number of source classification categories (SCCs), as part of the National Acid Precipitation Assessment Program (NAPAP). Each SCC represents a process or function t...

46

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

47

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

48

Emission of Volatile Sulfur Compounds from Spruce Trees 1  

PubMed Central

Spruce (Picea Abies L.) trees from the same clone were supplied with different, but low, amounts of plant available sulfate in the soil (9.7-18.1 milligrams per 100 grams of soil). Branches attached to the trees were enclosed in a dynamic gas exchange cuvette and analyzed for the emission of volatile sulfur compounds. Independent of the sulfate supply in the soil, H2S was the predominant reduced sulfur compound continuously emitted from the branches with high rates during the day and low rates in the night. In the light, as well as in the dark, the rates of H2S emission increased exponentially with increasing water vapor flux from the needles. Approximately 1 nanomole of H2S was found to be emitted per mole of water. When stomata were closed completely, only minute emission of H2S was observed. Apparently, H2S emission from the needles is highly dependent on stromatal aperture, and permeation through the cuticle is negligible. In several experiments, small amounts of dimethylsulfide and carbonylsulfide were also detected in a portion of the samples. However, SO2 was the only sulfur compound consistently emitted from branches of spruce trees in addition to H2S. Emission of SO2 mainly proceeded via an outburst starting before the beginning of the light period. The total amount of SO2 emitted from the needles during this outburst was correlated with the plant available sulfate in the soil. The diurnal changes in sulfur metabolism that may result in an outburst of SO2 are discussed.

Rennenberg, Heinz; Huber, Beate; Schroder, Peter; Stahl, Klaus; Haunold, Werner; Georgii, Hans-Walter; Slovik, Stefan; Pfanz, Hardy

1990-01-01

49

ECCAD : Emissions of Atmospheric Compounds and Compilation of Ancillary Data  

NASA Astrophysics Data System (ADS)

There is considerable uncertainty in estimating surface emissions of atmospheric compounds for the recent past and up to now, no single data set exists which would describe the geographical and temporal distribution of emissions for all species relevant to air quality, atmospheric composition change and climate change in a comprehensive and consistent manner. We will describe the ECCAD project, which has two major goals. The first goal is to provide scientific users with an easy access to a large number of existing datasets on surface emissions of atmospheric compounds at the global and regional scales. We are also providing access to ancillary data required to quantify surface emissions. The other goal is to provide data manipulation tools as well as statistical information over the different regions (climatic regions, continents, oceans, OECD regions, etc.). These tools allow an easy identification of each dataset characteristicss and differences between the datasets. Visualization tools are also provided, and the users can download the data of interest. The data in ECCAD are currently used in different international projects. The most recent addition to the database include the emissions developed in support of the IPCC AR5 report, and the data used in the MACC and CITYZEN European projects. The emissions are provided as gridded data at a 0.5 or 1° spatial resolution. Time periodicity and temporal coverage periods vary among the datasets from one year to up to 150 years. The database will be described, and examples of the tools will be presented. We will also provide information on the access to the datasets.

Sabine, Darras; Claire, Granier; Vincent, Pignot; Renaud, Bodichon; Aude, Mieville; Cathy, Liousse; Mireille, Paulin; Cathy, Boonne

2010-05-01

50

ECCAD : Emission of Atmospheric Compounds & Compilation of Ancillary Data  

NASA Astrophysics Data System (ADS)

There is considerable uncertainty in estimating surface emissions of atmospheric compounds for the recent past and up to now, no single data set exists which would describe the geographical and temporal distribution of emissions for all species relevant to air quality, atmospheric composition change and climate change in a comprehensive and consistent manner. We will describe the ECCAD project, which has two major goals. The first goal is to provide scientific users with an easy access to a large number of existing datasets on surface emissions of atmospheric compounds at the global and regional scales. We are also providing access to ancillary data required to quantify surface emissions. The other goal is to provide data manipulation tools as well as statistical information over the different regions (climatic regions, continents, oceans, OECD regions, etc.). These tools allow an easy identification of each dataset characteristics and differences between the datasets. Visualization tools are also provided, and the users can download the data of interest. The data in ECCAD are currently used in different international projects. The most recent addition to the database include the emissions developed in support of the IPCC AR5 report, and the data used in the MACC and CITYZEN European projects. The emissions are provided as gridded data at a 0.5 or 1° spatial resolution. Time periodicity and temporal coverage periods vary among the datasets from one year to up to 150 years. The database will be described, and examples of the tools will be presented. We will also provide information on the access to the datasets.

Darras, S.; Granier, C.; Pignot, V.; Bodichon, R.; Boonne, C.; Liousse, C.; Paulin, M.

2010-12-01

51

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

Code of Federal Regulations, 2013 CFR

...Organic Compound (VOC) emissions from bulk gasoline terminals. 60.502 Section 60...SOURCES Standards of Performance for Bulk Gasoline Terminals § 60.502 Standard for...Organic Compound (VOC) emissions from bulk gasoline terminals. On and after the...

2013-07-01

52

Volatile organic compound emission factors from roadside measurements  

NASA Astrophysics Data System (ADS)

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 photochemical smog. In this study, we estimated emission factors with a methodology that considered the following points: (1) real-world emissions, (2) individual VOCs, (3) low vehicle speeds, (4) low investigation cost, and (5) user-friendly methodology. Samples were collected approximately 5 m from each side of National Route No. 467 in Kanagawa Prefecture, Japan. Sampling consisted of twelve 1-h sampling periods at three points on three dates: 21 February 2003 (7:00-19:00), 13 May 2003 (7:00-19:00), and 13 September 2003 (8:00-20:00). The samples were analyzed using GC/FID and GC/MS. In addition, information on vehicle types, traffic volumes, and weather conditions was collected from beside the road. Emission factors of individual VOCs were estimated from the measured data by running the CALINE4 dispersion model as an inverse model. The average speed of all vehicles was 22 km h -1; 81.3% of all vehicles were light-duty vehicles, 12.3% were heavy-duty vehicles, and 6.5% were motorcycles. We estimated the emission factors of 34 individual VOCs. The emission factors for all vehicles combined averaged over all sampling days ranged from 0.25 to 51 mg vehicle -1 km -1. The emission factors of benzene and toluene were 5.2 and 17 mg vehicle -1 km -1, respectively. In addition, the estimated emission factors were compared with those estimated from other recent studies. The emission factors for light-duty vehicles (LDVs), heavy-duty vehicles (HDVs), and motorcycles separately were also estimated by using a non-negative least squares method. However, these emission factors were found to be unreliable for the current sample size; therefore, the sample size needed to estimate reliable emission factors was calculated.

Kawashima, Hiroto; Minami, Shigeki; Hanai, Yoshimichi; Fushimi, Akihiro

53

[Research advances on volatile organic compounds emission inventory of plants].  

PubMed

Reference to relative literatures in recent years, model building and calculation on volatile organic compound (VOC) emission inventory of plants were summarized in different spatial scales, the total annual VOC emission amounts from Vegetation in China are in the range from 12.4 Tg x a(-1) to 28.4 Tg x a(-1). For garden plants in Beijing, the annual VOC emissions are approximately 38 500 tons C in 2000. Furthermore, in order to determine reduction strategies for Beijing urban atmospheric major pollutants, the contribution of garden plant VOC emissions to the ozone and secondary organic aerosol (SOA) formation was presented, compared to garden plant in the same period, the largest contribution to ozone formation comes from aromatic hydrocarbons and olefin which are exhausted from anthropogenic activity, besides, the aromatic hydrocarbons exhausted from anthropogenic activity is also a main contribution source for the potential formation of SOA. In the meantime, it is suggested to focus on emission control of VOCs which are emitted from urban anthropogenic sources. PMID:24640923

Xie, Jun-Fei; Li, Yan-Ming

2013-12-01

54

Secondary particle emission from a ferromagnetic binary compound  

SciTech Connect

Secondary ion emission from an ion-bombarded binary compound in the ferro- and paramagnetic states has been studied using experimental methods and molecular dynamics simulations. The experiments were performed with a widely used NiPd binary compound, which was bombarded by obliquely incident 10-keV Ar ions. It is established that the intensity of Ni{sup +} and Pd{sup +} ion emission from a polycrystalline NiPd sample decreases significantly when it passes from the ferromagnetic to paramagnetic state. This effect is explained by a change in the surface binding energy and density of surface states at the Fermi level and by a cumulative process related to sputtering. The energies and directions of emission of secondary particles from poly- and single-crystalline NiPd samples in the ferromagnetic state have been jointly studied. It is established that the maximum of the polar angular distribution of secondary particles deviates toward the normal to the irradiated surface with a decrease in their energy. A difference in the azimuthal distribution of emitted Ni and Pd particles has been observed during the bombardment of a (001)NiPd crystal face and explained by specific features of correlated collisions. The best agreement of experimental data with the results of molecular dynamics simulations is obtained if the calculations are performed with allowance for an experimentally established modified composition of the three uppermost surface layers [39].

Minnebaev, K. F.; Tolpin, K. A.; Yurasova, V. E., E-mail: yurasova@physics.msu.ru [Moscow State University, Department of Physics (Russian Federation)

2013-02-15

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

Sources and Controls on Oceanic Emission of Volatile Iodinated Compounds  

NASA Astrophysics Data System (ADS)

Volatile iodinated compounds (VICs) influence tropospheric and stratospheric chemistry and have globally significant impacts on the concentrations and lifetimes of climatically active gases. The atmospheric lifetimes of VICs vary substantially, reflecting not only the relative reactivity of each chemical species but also how far they may be transported vertically in the atmosphere. Semi-lagrangian, open ocean experiments allowed the rates of net change of several VICs to be determined in the sub-tropical open ocean. When combined with measured and modeled rates of loss from the water column, including photolysis, chemical transformation and air-sea exchange, the ';gross' production rates of several VICs can be estimated. We compare the production rates of polyhalogenated versus monohalogenated compounds in the open-ocean environments, in part to examine whether they may be derived from contrasting primary sources. Estimates of air-sea flux based on water-column measurements of concentration and wind-based transfer velocity parameterizations from several field campaigns allow the dominant VIC vectors of iodine to the marine boundary layer to be determined. How this water-column derived VIC air-sea flux compares in magnitude and composition to emissions of reactive iodine potentially generated by processes at the air-sea interface involving ozone and iodide is assessed.

Archer, S. D.; Smyth, T.; Stephens, J.; Nightingale, P. D.

2013-12-01

57

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...

58

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

59

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...

60

Factors Controlling the Emissions of Monoterpenes and Other Volatile Organic Compounds.  

National Technical Information Service (NTIS)

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

D. T. Tingey D. P. Turner J. A. Weber

1990-01-01

61

Reduction of volatile organic compound emissions from the application of traffic markings. Final report  

Microsoft Academic Search

Traditional traffic marking materials (solvent-borne paints) are a source of volatile organic compound (VOC) emissions. The study was conducted to evaluate alternative traffic-marking techniques that can be used to reduce VOC emissions from this source. This document provides information on traffic marking application processes, VOC emissions and emission reductions, and costs associated with the alternative marking techniques. The primary conclusions

G. A. Aurand; M. B. Turner; C. J. Athey; R. M. Neulicht

1988-01-01

62

Emissions of volatile organic compounds from architectural materials with indoor applications  

Microsoft Academic Search

The objectives of this study were to identify the major organic compounds emitted by some typical building construction and interior finish materials, quantify emissions of organic solvents from representative adhesives that have indoor applications, and evaluate methods for the rapid screening of architectural materials for organic emissions. Organic compounds emitted by 15 building construction and interior finish materials and by

A. T. Hodgson; J. R. Girman; A. S. Newton; A. Winkes

1983-01-01

63

Atmospheric nitrogen compounds II: emissions, transport, transformation, deposition and assessment  

NASA Astrophysics Data System (ADS)

The Atmospheric Nitrogen Compounds II: Emissions, Transport, Transformation, Deposition and Assessment workshop was held in Chapel Hill, NC from 7 to 9 June 1999. This international conference, which served as a follow-up to the workshop held in March 1997, was sponsored by: North Carolina Department of Environment and Natural Resources; North Carolina Department of Health and Human Services, North Carolina Office of the State Health Director; Mid-Atlantic Regional Air Management Association; North Carolina Water Resources Research Institute; Air and Waste Management Association, RTP Chapter; the US Environmental Protection Agency and the North Carolina State University (College of Physical and Mathematical Sciences, and North Carolina Agricultural Research Service). The workshop was structured as an open forum at which scientists, policy makers, industry representatives and others could freely share current knowledge and ideas, and included international perspectives. The workshop commenced with international perspectives from the United States, Canada, United Kingdom, the Netherlands, and Denmark. This article summarizes the findings of the workshop and articulates future research needs and ways to address nitrogen/ammonia from intensively managed animal agriculture. The need for developing sustainable solutions for managing the animal waste problem is vital for shaping the future of North Carolina. As part of that process, all aspects of environmental issues (air, water, soil) must be addressed as part of a comprehensive and long-term strategy. There is an urgent need for North Carolina policy makers to create a new, independent organization that will build consensus and mobilize resources to find technologically and economically feasible solutions to this aspect of the animal waste problem.

Aneja, Viney P.; Roelle, Paul A.; Murray, George C.; Southerland, James; Erisman, Jan Willem; Fowler, David; Asman, Willem A. H.; Patni, Naveen

64

Trace gas compound emissions from municipal landfill sanitary sites  

NASA Astrophysics Data System (ADS)

The literature on certain aspects of trace gas compounds emitted from Municipal Landill Sanitary Sites is reviewed. Aspects covered are the formation, nature and origin of such compounds, as well as the problems caused by them. Risks posed to human health and the environment by even low concentrations of these compounds are examined and methods to reduce and control them discussed.

Brosseau, Josée; Heitz, Michèle

65

Study on fugitive emission model of volatile organic compounds and effects of additives on the emission rate  

Microsoft Academic Search

In order to effectively control air quality in a plant, the Volatile Organic Compounds (VOCs) emission model was developed to study the effects of influential factors on emission rate. The emission rates of MEK(methyl ethyl ketone), TOL(toluene, ANONE(cyclohexanone) were about in the range of 16.1 × 10 to 101.0 × 10 mg\\/m\\/hr\\/(g?MEK), 14.3 × 10 to 88.1 × 10 mg\\/m\\/hr\\/(g?TOL),

1994-01-01

66

Temporal variation of trace compound emission on the working surface of a landfill in Beijing, China  

NASA Astrophysics Data System (ADS)

The temporal variation of trace component emissions from the working surface of a landfill in Beijing was investigated. Specific days in a year were selected as representatives for all four seasons. Different chemical species were quantified in all four seasons with the following average concentrations: spring: 41 compounds, 2482.6 ?g m?3; summer: 59 compounds, 4512.6 ?g m?3; fall: 66 compounds, 2438.4 ?g m?3; and winter: 54 compounds, 2901 ?g m?3. The detected compounds included sulfur compounds, oxygenated compounds, aromatics, hydrocarbons, halogenated compounds, and terpenes. Oxygenated compounds were the most abundant compound in most samples. Isobutane, ethyl alcohol, limonene, butane, toluene, and trichlorofluoromethane were recognized as the most abundant compounds on the working surface throughout the year. This study would bring new light in assessing the particle pollution in urban areas and the effect of trace components on landfill odor.

Duan, Zhenhan; Lu, Wenjing; Li, Dong; Wang, Hongtao

2014-05-01

67

NATURAL EMISSIONS OF NON-METHANE VOLATILE ORGANIC COMPOUNDS, CARBON MONOXIDE, AND OXIDES OF NITROGEN FROM NORTH AMERICA  

EPA Science Inventory

The magnitudes, distributions, controlling processes and uncertainties associated with North American natural emissions of oxidant precursors are reviewed. Natural emissions are repsonsible for a major portion of the compounds, including non-methane volatile organic compounds (N...

68

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

69

Seasonal biogenic volatile organic compound emission trends of four coniferous tree species  

NASA Astrophysics Data System (ADS)

Many studies on biogenic volatile organic compounds (BVOC) have characterized emission rates with dependencies on temperature and light radiation. Few studies have examined emission trends in relation to seasonal variation. In this study, BVOC emissions of several coniferous tree species were monitored in Boulder, Colorado for one complete seasonal cycle between 2009 and 2010. Four coniferous tree species native to Colorado were selected; a ponderosa pine, blue spruce, douglas fir and bristlecone pine. BVOC emissions were collected using branch enclosure methods and sampled onto solid adsorbent cartridges with subsequent analysis by thermal desorption, gas chromatography-mass spectrometry. Tree species were sampled monthly for 3 to 5 days time period throughout the entire year. Temperature and photosynthetically active radiation were monitored concurrently with emission samples. Monoterpenes and oxidized monoterpenes were the dominant BVOC emissions. Emissions from all tree species displayed strong temperature dependence with highest emission rates observed between May - July and minimal emissions during the winter season.

Daly, R. W.; Helmig, D.; Guenther, A. B.; Baghi, R.; Baroch, C.; Borke, C.

2010-12-01

70

VOLATILE ORGANIC COMPOUNDS FROM VEGETATION IN SOUTHERN YUNNAN PROVINCE, CHINA: EMISSION RATES AND SOME POTENTIAL REGIONAL IMPLICATIONS  

EPA Science Inventory

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 BVO...

71

Emissions of volatile organic compounds by coal-fired power stations  

Microsoft Academic Search

Al~traet--This study concerns the emissions of volatile organic compounds (VOC) by coal-fired power stations. The most abundant compounds are aldehydes (formaldehyde and acetaldehyde), aliphatic and aromatic hydrocarbons (toluene, xylenes, ethylbenzene and benzene) and chlorinated hydrocarbons (tetrachlorocthene). The relative importance of combustion parameters determining the level and the nature of emissions is described. The most important of these is th,e load

J. P. GARCIA; S. BEYNE-MASCLET; G. MOUVIER; P MASCLET

1992-01-01

72

Measurements of biogenic non-methane organic compound emissions from grasslands  

SciTech Connect

Non-methane organic compounds (NMOCs) play an important role in the formation of photochemical oxidants in the troposphere. NMOCs originate from both anthropogenic and biogenic sources. Many organic compounds of biogenic origins are more reactive than those of anthropogenic origin because of the presence of internal double bonds within their molecular structure. The objective of this investigation was to examine the seasonal variation of NMOC emissions from grasslands and determine the environmental factors that control the emissions. An enclosure system was chosen as the most appropriate sampling technique for measuring emissions from herbaceous vegetation, and an analysis method using cryogenic preconcentration/high resolution gas chromatography was established. Emission rates were measured at a fixed location in a natural grassland during 1992 and 1993. Measurements were also made at various locations within the same site where the vegetation was harvested after the emission rates were determined. Emission rates of NMOCs for grasslands are not as large as those reported for forests. However the emissions of oxygenated hydrocarbons exceeded the emissions of monoterpenes and have not previously been identified as important forest-type emissions. A framework for parameterizing the NMOC emissions from grasslands based on seasonal and instantaneous variations of the emission rate measurements was developed. Temperature, hypoxia induced by water saturated soil, and frost were key environmental factors affecting both the composition and magnitude of NMOC emissions.

Fukui, Yoshiko

1994-12-31

73

REASSESSMENT OF BIOGENIC VOLATILE ORGANIC COMPOUND EMISSIONS IN THE ATLANTA AREA  

EPA Science Inventory

The paper discusses a reassessment of biogenic volatile organic compound (BVOC) emissions in the Atlanta area, using a new system for specific tree genera at hourly and county levels. (NOTE: Localized estimates of BVOC emissions are important inputs for photochemical oxidant simu...

74

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

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

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

77

Emissions of acetic acid and other volatile organic compounds from different species of solid wood  

Microsoft Academic Search

The emission of volatile organic compounds (VOC) from wood and wood products are important in evaluating the impact on the\\u000a indoor environment from different materials. The results from analyses of emissions from nine different wood species are presented\\u000a in this article. The measurements were made with Field and Laboratory Emission Cell (FLEC) and with Head-Space (HS) analyses\\u000a and the results

M. Risholm-Sundman; M. Lundgren; E. Vestin; P. Herder

1998-01-01

78

Recent changes in particulate air pollution over China observed from space and the ground: effectiveness of emission control.  

PubMed

The Chinese government has moved aggressively since 2005 to reduce emissions of a number of pollutants including primary particulate matter (PM) and sulfur dioxide (SO(2)), efforts inadvertently aided since late 2008 by economic recession. Satellite observations of aerosol optical depth (AOD) and column nitrogen dioxide (NO(2)) provide independent indicators of emission trends, clearly reflecting the sharp onset of the recession in the fall of 2008 and rebound of the economy in the latter half of 2009. Comparison of AOD with ground-based observations of PM over a longer period indicate that emission-control policies have not been successful in reducing concentrations of aerosol pollutants at smaller size range over industrialized regions of China. The lack of success is attributed to the increasing importance of anthropogenic secondary aerosols formed from precursor species including nitrogen oxides (NO(x)), non-methane volatile organic compounds (NMVOC), and ammonia (NH(3)). PMID:20828193

Lin, Jintai; Nielsen, Chris P; Zhao, Yu; Lei, Yu; Liu, Yang; McElroy, Michael B

2010-10-15

79

Volatile Organic Compound Emissions from Dry Mill Fuel Ethanol Production  

Microsoft Academic Search

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

Daniel Brady; Gregory C. Pratt; L.-W. Chen; M. C. Chang; Norman Robinson; Dana Trimble; Steven Kohl; John Watson; Hsing-Wang Li; Yee-Lin Wu; Wen-Jhy Lee; Guo-Ping Chang-Chien; Joao Gomes; Joana Nascimento; Helena Rodrigues; David Schaad; James Halley; Vince Alaimo; David Epperson; Miriam Lev-On; Hal Taback; Jeffrey Siegell; Karin Ritter; Yu Zhou; Lixin Fu; Linglin Cheng; Pao-Wen Liu; Qingzhong Yuan; Kalliat Valsaraj; Danny Reible; Clinton Willson; Wipada Sanongraj; Yongsheng Chen; John Crittenden; Hugo Destaillats; David Hand; David Perram; Roy Taylor; Sangil Lee; Armistead Russell; Karsten Baumann

2007-01-01

80

Modeling toxic compounds from nitric oxide emission measurements  

Microsoft Academic Search

Determining the amount and rate of degradation of toxic pollutants in soil and groundwater is difficult and often requires invasive techniques, such as deploying extensive monitoring well networks. Even with these networks, degradation rates across entire systems cannot readily be extrapolated from the samples. When organic compounds are degraded by microbes, especially nitrifying bacteria, oxides or nitrogen (NOx) are released

Daniel A. Vallero; Jeffrey Peirce; Ki Don Cho

2009-01-01

81

Off-season biogenic volatile organic compound emissions from heath mesocosms: responses to vegetation cutting.  

PubMed

Biogenic volatile organic compounds (BVOCs) affect both atmospheric processes and ecological interactions. Our primary aim was to differentiate between BVOC emissions from above- and belowground plant parts and heath soil outside the growing season. The second aim was to assess emissions from herbivory, mimicked by cutting the plants. Mesocosms from a temperate Deschampsia flexuosa-dominated heath ecosystem and a subarctic mixed heath ecosystem were either left intact, the aboveground vegetation was cut, or all plant parts (including roots) were removed. For 3-5 weeks, BVOC emissions were measured in growth chambers by an enclosure method using gas chromatography-mass spectrometry. CO2 exchange, soil microbial biomass, and soil carbon and nitrogen concentrations were also analyzed. Vegetation cutting increased BVOC emissions by more than 20-fold, and the induced compounds were mainly eight-carbon compounds and sesquiterpenes. In the Deschampsia heath, the overall low BVOC emissions originated mainly from soil. In the mixed heath, root, and soil emissions were negligible. Net BVOC emissions from roots and soil of these well-drained heaths do not significantly contribute to ecosystem emissions, at least outside the growing season. If insect outbreaks become more frequent with climate change, ecosystem BVOC emissions will periodically increase due to herbivory. PMID:23966983

Rinnan, Riikka; Gierth, Diana; Bilde, Merete; Rosenørn, Thomas; Michelsen, Anders

2013-01-01

82

Formation and emission of volatile polonium compound by microbial activity and polonium methylation with methylcobalamin.  

PubMed

We observed biologically mediated emission of Po from culture solution inoculated sea sediment extract and incubated under natural light/dark cycle condition or dark condition the emitted Po compound would be lipophilic because of effective collection in organic solvent. Sterilization of the culture medium with antibiotics or CuSO4 completely suppressed growth of microorganisms and resulted in no emission of Po, indicating biological activity of microorganisms is responsible for formation and emission of volatile Po compound. Po emission also occurred when seawater was used as a culture medium. Our finding indicates a possibility of biotic source for atmospheric Po in the environment, which has been believed to be originated from abiotic sources. We compared emission behavior of Po and S in the culture experiments, the elements belong to XVI group in the Periodical Table, and consider that their emission mechanisms involved would be different though the emission of both elements is supported by biological activity of microorganisms. One of the chemical forms of S emitted was confirmed to be dimethyl sulfide (DMS) but that of Po is not known. Methylation experiments of Po with methylcobalamin demonstrated a formation and emission of volatile Po compound. The methylation of Po with methylcobalamin might be related to the observed Po emission in the culture experiments. PMID:11478248

Momoshima, N; Song, L X; Osaki, S; Maeda, Y

2001-07-15

83

Modeling toxic compounds from nitric oxide emission measurements  

NASA Astrophysics Data System (ADS)

Determining the amount and rate of degradation of toxic pollutants in soil and groundwater is difficult and often requires invasive techniques, such as deploying extensive monitoring well networks. Even with these networks, degradation rates across entire systems cannot readily be extrapolated from the samples. When organic compounds are degraded by microbes, especially nitrifying bacteria, oxides or nitrogen (NO x) are released to the atmosphere. Thus, the flux of nitric oxide (NO) from the soil to the lower troposphere can be used to predict the rate at which organic compounds are degraded. By characterizing and applying biogenic and anthropogenic processes in soils the rates of degradation of organic compounds. Toluene was selected as a representative of toxic aromatic compounds, since it is inherently toxic, it is a substituted benzene compound and is listed as a hazardous air pollutant under Section 12 of the Clean Air Act Amendments of 1990. Measured toluene concentrations in soil, microbial population growth and NO fluxes in chamber studies were used to develop and parameterize a numerical model based on carbon and nitrogen cycling. These measurements, in turn, were used as indicators of bioremediation of air toxic (i.e. toluene) concentrations. The model found that chemical concentration, soil microbial abundance, and NO production can be directly related to the experimental results (significant at P < 0.01) for all toluene concentrations tested. This indicates that the model may prove useful in monitoring and predicting the fate of toxic aromatic contaminants in a complex soil system. It may also be useful in predicting the release of ozone precursors, such as changes in reservoirs of hydrocarbons and oxides of nitrogen. As such, the model may be a tool for decision makers in ozone non-attainment areas.

Vallero, Daniel A.; Peirce, Jeffrey; Cho, Ki Don

84

Effects of bulking agent addition on odorous compounds emissions during composting of OFMSW.  

PubMed

The effects of rice straw addition level on odorous compounds emissions in a pilot-scale organic fraction of municipal solid waste (OFMSW) composting plant were investigated. The cumulative odorous compounds emissions occurred in a descending order of 40.22, 28.71 and 27.83mg/drykg of OFMSW for piles with rice straw addition level at ratio of 1:10, 2:10 and 3:10 (mixing ratio of rice straw to OFMSW on a wet basis), respectively. The mixing ratio of rice straw to OFMSW had a statistically significant effect on the reduction of malodorous sulfur compounds emissions, which had no statistically significant effect on the reduction of VFAs, alcohols, aldehydes, ketones, aromatics and ammonia emissions during composting, respectively. The cumulative emissions of malodorous sulfur compounds from piles with the increasing rice straw addition level were 1.17, 1.08 and 0.88mg/drykg of OFMSW, respectively. The optimal mixing ratio of rice straw to OFMSW was 1:5. Using this addition level, the cumulative malodorous sulfur compounds emissions based on the organic matter degradation were the lowest during composting of OFMSW. PMID:24820662

Shao, Li-Ming; Zhang, Chun-Yan; Wu, Duo; Lü, Fan; Li, Tian-Shui; He, Pin-Jing

2014-08-01

85

Regional atmospheric emissions determined from measurements at Jeju Island, Korea: Halogenated compounds from China  

NASA Astrophysics Data System (ADS)

High-frequency in-situ measurements of a wide range of halogenated compounds including chlorofluorocarbons (CFCs), halons, hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), perfluorinated compounds (PFCs), sulfur hexafluoride (SF6), and other chlorinated and brominated compounds have been made at Gosan (Jeju Island, Korea). Regional emissions of HCFC-22 (CHClF2) calculated from inverse modeling were combined with interspecies correlation methods to estimate national emissions for China, a major emitter of industrial halogenated gases. Our results confirm the signs of successful phase-out of primary ozone-depleting species such as CFCs, halons and many chlorinated or brominated compounds, along with substantial emissions of replacement HCFCs. Emissions derived for HFCs, PFCs, and SF6 were compared to published estimates and found to be a significant fraction of global totals. Overall, Chinese emissions of the halogenated compounds discussed here represent 19(14-17)% and 20(15-26)% of global emissions when evaluated in terms of their Ozone Depletion Potentials and 100-year Global Warming Potentials, respectively.

Kim, Jooil; Li, Shanlan; Kim, Kyung-Ryul; Stohl, Andreas; Mühle, Jens; Kim, Seung-Kyu; Park, Mi-Kyung; Kang, Dong-Jin; Lee, Gangwoong; Harth, Christina M.; Salameh, Peter K.; Weiss, Ray F.

2010-06-01

86

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 contaminants 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-nitrosamines 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 ({mu}g/cigarette) 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. [Lawrence Berkeley Lab., CA (United States)

1994-10-01

87

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

88

Dielectric barrier discharge carbon atomic emission spectrometer: universal GC detector for volatile carbon-containing compounds.  

PubMed

It was found that carbon atomic emission can be excited in low temperature dielectric barrier discharge (DBD), and an atmospheric pressure, low power consumption, and compact microplasma carbon atomic emission spectrometer (AES) was constructed and used as a universal and sensitive gas chromatographic (GC) detector for detection of volatile carbon-containing compounds. A concentric DBD device was housed in a heating box to increase the plasma operation temperature to 300 °C to intensify carbon atomic emission at 193.0 nm. Carbon-containing compounds directly injected or eluted from GC can be decomposed, atomized, and excited in this heated DBD for carbon atomic emission. The performance of this new optical detector was first evaluated by determination of a series of volatile carbon-containing compounds including formaldehyde, ethyl acetate, methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol, and absolute limits of detection (LODs) were found at a range of 0.12-0.28 ng under the optimized conditions. Preliminary experimental results showed that it provided slightly higher LODs than those obtained by GC with a flame ionization detector (FID). Furthermore, it is a new universal GC detector for volatile carbon-containing compounds that even includes those compounds which are difficult to detect by FID, such as HCHO, CO, and CO2. Meanwhile, hydrogen gas used in conventional techniques was eliminated; and molecular optical emission detection can also be performed with this GC detector for multichannel analysis to improve resolution of overlapped chromatographic peaks of complex mixtures. PMID:24328147

Han, Bingjun; Jiang, Xiaoming; Hou, Xiandeng; Zheng, Chengbin

2014-01-01

89

Variations in the emissions of volatile organic compounds from the toner for a specific photocopier.  

PubMed

A laboratory thermal desorption apparatus was used to measure emissions from a number of nominally identical photocopier toners--manufactured to meet the specifications of one specific model copier--when these toners were heated to fuser temperature (180-200 degrees C). The objective was to assess how potential volatile organic compound (VOC) emissions from the toner for a given copier can vary, depending upon the production run and the supplier. Tests were performed on a series of toner (and associated raw polymer feedstock) samples obtained directly from a toner manufacturer, representing two production runs using a nonvented extrusion process, and on toner cartridges purchased from two local retailers, representing three different production lots (histories unknown). The results showed that the retailer toners consistently had up to 350% higher emissions of some major compounds (expressed as microgram of compound emitted/g of toner), and up to 100% lower emissions of others, relative to the manufacturer toners (p < or = 0.01). The manufacturer toners from one production run had emissions of certain compounds, and of total VOCs, that were modestly higher (13-18%) than those from the other run (p < or = 0.01). The emission differences between the retailer and manufacturer toners are probably due to differences in the manufacturing processes and/or feedstocks used to produce the toners from these different sources. PMID:11355458

Henschel, D B; Fortmann, R C; Roache, N F; Liu, X

2001-05-01

90

Biogenic volatile organic compound emissions from desert vegetation of the southwestern US  

NASA Astrophysics Data System (ADS)

Thirteen common plant species in the Mojave and Sonoran Desert regions of the western US were tested for emissions of biogenic non-methane volatile organic compounds (BVOCs). Only two of the species examined emitted isoprene at rates of 10 ?g C g -1 h -1or greater. These species accounted for <10% of the estimated vegetative biomass in these arid regions of low biomass density, indicating that these ecosystems are not likely a strong source of isoprene. However, isoprene emissions from these species continued to increase at much higher leaf temperatures than is observed from species in other ecosystems. Five species, including members of the Ambrosia genus, emitted monoterpenes at rates exceeding 2 ?g C g -1 h -1. Emissions of oxygenated compounds, such as methanol, ethanol, acetone/propanal, and hexanol, from cut branches of several species exceeded 10 ?g C g -1 h -1, warranting further investigation in these ecosystems. Model extrapolation of isoprene emission measurements verifies recently published observations that desert vegetation is a small source of isoprene relative to forests. Annual and daily total model isoprene emission estimates from an eastern US mixed forest landscape were 10-30 times greater than isoprene emissions estimated from the Mojave site. Monoterpene (and possibly oxygenated terpene and sesquiterpene) emissions may be more comparable, as annual forest terpene emission model estimates were 3-8 times greater than those from the Mojave Desert, and were within a factor of 2 for peak summertime fluxes. Primary productivity and leaf biomass of desert ecosystems are very dependent on annual precipitation, and our model results indicate that there can be at least a three-fold difference in total annual BVOC emissions between dry and wet years. We recommend additional studies of desert plant BVOC emissions, especially those that focus on sesquiterpenes, oxygenated compounds, and the effects of soil moisture, temperature, humidity, and seasonality. Landscape flux studies are needed to test BVOC model estimates and to verify BVOC influences on regional atmospheric chemistry.

Geron, Chris; Guenther, Alex; Greenberg, Jim; Karl, Thomas; Rasmussen, Rei

91

Selective detection of carbon-13-labeled compounds by gas chromatography/emission spectroscopy  

SciTech Connect

This paper describes a technique which also provides selective GC detection of compounds with excess {sup 13}C content. Molecular emission from CO bands in the vacuum ultraviolet region is monitored with an atomic emission detector (AED) (4,5). Samples can also be analyzed for C, H, O, N, S, P, Cl, F, etc. by changing the reagent and makeup gas flows. This combination of {sup 13}C specificity with atomic information is useful in the identification of unknown compounds, especially when combined with mass spectral data, as shown by Hooker and DeZwaan (6).

Quimby, B.D.; Dryden, P.C.; Sullivan, J.J. (Hewlett-Packard Company, Avondale, PA (USA))

1990-11-15

92

Analyzing thermally unstable natural organic compounds by secondary ion emission with the MI 1201 mass spectrometer  

SciTech Connect

The authors consider the secondary-emission mass spectra of biorganic compounds of various classes and evaluate the scope for determining their molecular masses and structures. A Cs/sup +/ primary beam was used because cesium is the heaviest of the nonradioactive alkali metals, and the yield of secondary molecular ions is the higher the heavier the primary ion. The authors present secondary-emission mass spectra for biorganic compounds of various classes 18 out of 20 genetically coded amino acids and thyroxine, nucleotides, steroids, sulfonic acid derivatives, and a disaccharide: sucrose.

Malakov, K.V.; Dobychin, S.L.; Turkina, M.Y.

1986-09-01

93

NATURAL EMISSIONS OF NON-METHANE VOLATILE ORGANIC COMPOUNDS, CARBON MONOXIDE, AND OXIDES OF NITROGEN FROM NORTH AMERICA. (R825259)  

EPA Science Inventory

Abstract 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 o...

94

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

95

SPATIAL AND SOURCE TYPE DISTRIBUTION OF EMISSIONS OF SELECTED TOXIC VOLATILE ORGANIC COMPOUNDS IN THE UNITED STATES IN 1990  

EPA Science Inventory

The annual anthropogenic emission, principal contributing source types, and spatial distributions for selected toxic volatile organic compounds (VOCS) are presented for the United States. oxic compounds addressed include acrylonitrile, benzene, perchloroethylene, and trichloroeth...

96

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

97

The contribution of evaporative emissions from gasoline vehicles to the volatile organic compound inventory in Mexico City.  

PubMed

The strategy for decreasing volatile organic compound emissions in Mexico has been focused much more on tailpipe emissions than on evaporative emissions, so there is very little information on the contribution of evaporative emissions to the total volatile organic compound inventory. We examined the magnitudes of exhaust and evaporative volatile organic compound emissions, and the species emitted, in a representative fleet of light-duty gasoline vehicles in the Metropolitan Area of Mexico City. The US "FTP-75" test protocol was used to estimate volatile organic compound emissions associated with diurnal evaporative losses, and when the engine is started and a journey begins. The amount and nature of the volatile organic compounds emitted under these conditions have not previously been accounted in the official inventory of the area. Evaporative emissions from light-duty vehicles in the Metropolitan Area of Mexico City were estimated to be 39 % of the total annual amount of hydrocarbons emitted. Vehicles built before 1992 (16 % of the fleet) were found to be responsible for 43 % of the total hydrocarbon emissions from exhausts and 31 % of the evaporative emissions of organic compounds. The relatively high amounts of volatile organic compounds emitted from older vehicles found in this study show that strong emission controls need to be implemented in order to decrease the contribution of evaporative emissions of this fraction of the fleet. PMID:24526614

Schifter, I; Díaz, L; Rodríguez, R; González-Macías, C

2014-06-01

98

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

99

Rendering plant emissions of volatile organic compounds during sterilization and cooking processes.  

PubMed

The rendering process emits odorous volatile compounds in the atmosphere; if these volatile organic compounds (VOCs) are not handled properly they can cause a serious environmental problem. During this process not all emitted compounds are odorous and hazardous but some of them have been found associated with health problems. Samples were collected in the plastic bags from the Arnout rendering plant. In this study, VOCs emission from two different processes (cooking and sterilization) was compared. For the analysis of various emitted compounds, gas chromatograph and mass spectrophotometer were used. A sterilization process was added in the rendering plant to inactivate the prion protein from meat bone meal prepared during the rendering process. The identification of mass spectrum was performed by using a mass spectral database system. The most odorous classes of compounds identified were aliphatic hydrocarbons (HCs) (29.24%), furans (28.74%), aromatic HCs (18.32%), most important sulphur-containing compounds (12.15%), aldehyde (10.91%) and ketones (0.60%). Emissions released during cooking and sterilization were 32.73 x 10(2) and 36.85 x 10(2) mg m(-3), respectively. In this study, it was observed that after the addition of the sterilization process VOCs' emissions were increased. A total of 87 mg m(-3) dimethyl disulphide (DMS) was detected only during the cooking process, whereas dimethly trisulphide (DMTS) was detected in both cooking (300 mg m(-3)) and sterilization (301 mg m(-3)) processes. About 11 mg m3 of DMS was detected during the cooking process, which was a small concentration compared with 299 mg m(-3) found during the sterilization process. At high temperature and pressure, DMTS and DMS were released more than any other sulphur-containing compounds. A condenser was applied to control the combined emission and it was successful in the reduction of VOCs to 22.83 x 10(2) mg m(-3) (67% reduction). PMID:24701929

Bhatti, Z A; Maqbool, F; Langenhove, H V

2014-01-01

100

Development and evaluation of a mass spectrometer-based continuous emission monitor for volatile organic compound emissions from combustion devices.  

PubMed

A mass spectrometer-based continuous emission monitor (MS-CEM) for organic compound emissions from combustion devices was developed and evaluated at the Louisiana State University (LSU) pilot-scale rotary kiln incinerator (RKI). The MS-CEM consists of a stack probe, heat-traced sampling line, vacuum pump, particulate filter, Nafion@ dryer and mass spectrometer. The mass spectrometer includes a computer that controls and optimizes the operation of the unit. The MS-CEM is capable of continuously analyzing up to 40 different volatile organic compounds on a real-time basis. The MS-CEM is capable of analyzing, computing and recording the analytical results for each and up to 40 different organic compounds in less than 0.3 s. Four different volatile organic compounds were mixed together and injected into the baghouse inlet while simultaneously analyzing each organic component exiting the RKI stack gas. The results obtained from MS-CEM were compared with the material balance values. The system response time (including the MS-CEM) varies from 1.1 to 1.5 min. PMID:11280990

Wada, E T; Sterling, A M

2001-01-01

101

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

102

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

2013-11-01

103

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...

104

BIOGENIC VOLATILE ORGANIC COMPOUND EMISSIONS FROM A LOWLAND TROPICAL WET FOREST IN COSTA RICA  

EPA Science Inventory

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 bas...

105

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 ...

106

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...

107

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...

108

Effects of nonmethane volatile organic compounds on microbial community of methanotrophic biofilter.  

PubMed

Effects of nonmethane volatile organic compounds (NMVOCs) on methanotrophic biofilter were investigated. Laboratory-scale biofilters packed with pumice and granular-activated carbon (10:1, w/w) were operated with CH4 and NMVOCs including dimethyl sulfide (DMS) and benzene/toluene (B/T). DMS alone exhibited a positive effect on the methanotrophic performance; however, the coexistence of B/T removed this effect. B/T alone exerted no effect on the performance. Pyrosequencing and quantitative PCR revealed that the NMVOCs strongly influenced the bacterial and methanotrophic communities but not the population density of methanotrophs. DMS alone diversified and changed both bacterial and methantrophic communities, but its effects were nullified by the presence of B/T. Canonical correspondence analysis revealed significant correlations between the NMVOCs and community composition and significant interaction between DMS and B/T. DMS did not affect the distribution of types I/II methanotrophs (60/40), while B/T increased the abundance of type I to 82 %. DMS and B/T favored the growth of the methanotrophic bacteria Methylosarcina and Methylomonas, respectively. These results suggest that NMVOCs can be a significant abiotic factor influencing methane biofiltration. PMID:23053093

Kim, Tae Gwan; Lee, Eun-Hee; Cho, Kyung-Suk

2013-07-01

109

Diurnal and seasonal variability of gasoline-related volatile organic compound emissions in Riverside, California.  

PubMed

On- and off-road mobile sources are the dominant contributors to urban anthropogenic volatile organic compound (AVOC) emissions. Analyses of gasoline samples from California for both summer and winter indicate significant differences in liquid fuel and vapor chemical composition due to intentional seasonal adjustments. Ambient concentrations of 55 VOCs were measured via in situ gas chromatography in the 2005 Study of Organic Aerosols at Riverside (SOAR) during both summer and fall. A chemical mass balance analysis was used to differentiate vapor pressure-driven VOC emissions from other motor vehicle-related emissions such as tailpipe exhaust. Overall, fuel vapor emissions accounted for 31 +/- 2% of gasoline-related VOC in Riverside; California's emission factor model similarly estimates 31% of gasoline-related VOC emissions are fuel vapor. The diurnal pattern of vapor pressure-driven VOC source contributions is relatively stable around 10 microg/m3, while whole gasoline (i.e., tailpipe) contributions peak at approximately 60 microg/m3 during the morning commute. There is no peak in whole gasoline source contributions during the afternoon, due to rapid dilution associated with high mixing heights and wind speeds in the Riverside area. The relationship between estimated gasoline-related VOC and observed carbon monoxide concentrations in this study is similar to California's 2005 emission inventory; we calculated a VOC to CO mass ratio of 0.086 +/- 0.006 (95% CI) compared to 0.097 in the emission inventory for all gasoline-related sources. PMID:19603630

Gentner, Drew R; Harley, Robert A; Miller, Angela M; Goldstein, Allen H

2009-06-15

110

Emission of reactive compounds and secondary products from wood-based furniture coatings  

NASA Astrophysics Data System (ADS)

Emissions of organic fragmentation products, so-called "secondary emission products" and reactive species from wood-based furniture coatings have been studied in 1 m 3 test chambers. the climatic conditions were representative of indoor environments. Relevant compounds and compound groups were the wetting agent 2,4,7,9-tetramethyl-5-dicyne-4,7-diol (T4MDD), the plasticiser di-2-ethyl-hexyl-phthalate (DEHP), aliphatic aldehydes, monoterpenes, photoinitiator fragments, acrylic monomers/reactive solvents and diisocyanate monomers. Such substances may affect human health in several ways. Aliphatic aldehydes and some photoinitiator fragments are of strong odour, while acrylates and diisocyanates cause irritation of skin, eyes and upper airways. Terpenes and reactive solvents like styrene undergo indoor chemistry in the presence of ozone, nitrogen oxides or hydroxy radicals. Secondary emission products and reactive species can achieve significant indoor concentrations. On the other hand, it has been reported that even small quantities can cause health effects. In the cases of indoor studies with special regard to emissions from furniture, chemical analysis should always include these compounds.

Salthammer, T.; Schwarz, A.; Fuhrmann, F.

111

Speciated non-methane organic compounds emissions from food cooking in Mexico  

NASA Astrophysics Data System (ADS)

Non-methane organic compound (NMOC) emissions from different sorts of food preparation sites, were quantified for the first time in Mexico, in order to develop emission profiles for further application in the chemical mass balance receptor model (CMB). Restaurants using charcoal grills and LP gas stoves, "tortiller?´as", food frying places and rotisseries were sampled using SUMMA ® stainless-steel canisters to analyse NMOC by high-resolution gas chromatography. The results obtained show that profiles determined from food cooking processes have similarities to those found in LP gas combustion, which is the most common fuel in Mexico used for this purpose, although there were differences in the relative composition of propane and butane in both cases. This suggests that, the rates of combustion of propane and butane are different. It has also been detected that propene, a reactive olefin is produced during the combustion process. The obtained profiles of restaurants, rotisseries and fried food show an important contribution of two carbon compounds (ethane, ethylene and acetylene) that can be attributed to the complex process of grease and meat cooking. The presence of these compounds cannot be attributed to vehicular sources since the concentrations are higher than in ambient air. These were also determined from aromatic compounds such as benzene, toluene and xylene in the combustion of vegetal charcoal. The measured concentrations indicate that NMOC emissions from cooking may become an important indoor source of NMOC under crowded conditions in closed places.

Mugica, V.; Vega, E.; Chow, J.; Reyes, E.; Sánchez, G.; Arriaga, J.; Egami, R.; Watson, J.

112

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

113

Volatile organic compound emissions from latex paint--Part 1. Chamber experiments and source model development.  

PubMed

Latex paints are widely used in residential and commercial indoor environments. The surface areas covered by the paints in these environments are relatively large. Thus, latex paints have the potential for having a major impact on indoor air quality (IAQ). A study was undertaken to develop methods for evaluating the impact of latex paint emission on IAQ. Small chamber experiments using stainless steel and painted and unpainted gypsum board substrates were conducted to determine the emission characteristics of latex paint. The emissions from the stainless steel were relatively short lived (3 to 4 days), whereas the emissions from gypsum board lasted for over 200 days. Because gypsum board is a common substrate for latex paint, all emission models were developed for the gypsum board substrates. The data from the small chamber tests led to the development of two empirical and two mass-transfer-based source emission models. Approximately 100 to 200 days of data were required to estimate the parameters required for the empirical models. Only 8 days of data were required to estimate the parameters for the mass-transfer-based models. The final models use paint formulation and mass transfer correlations to predict the emissions of the major individual volatile organic compounds emitted by latex paint. PMID:10195271

Sparks, L E; Guo, Z; Chang, J C; Tichenor, B A

1999-03-01

114

Emissions of volatile organic compounds from dry leaf litter and their dependence on temperature  

NASA Astrophysics Data System (ADS)

Emissions of several volatile organic compounds (VOCs) from dry leaf litter at temperatures in the range 20 - 100°C are measured for different plant species. The emission rates of ethane, ethene, propane, propene, n-pentane and methyl chloride increase exponentially with temperature and follow the Arrhenius relation. Emission rates up to 650 ng/gdw/hr were measured for hydrocarbons at 70°C, while for methyl chloride emission rates up to 18 ?g/gdw/hr were measured at this temperature. Activation energies derived from the Arrhenius plots are generally higher than 50 kJ/mol, which is an indication that the emissions are of abiotic origin. The emission of VOCs from dry leaf litter decreases in time, due to depletion of the precursor reservoirs. At low temperatures (20 - 30°C) the decrease is very slow, but at higher temperatures (80 - 100°C) it is noticeable on a timescale of hours. Our results show that hydrocarbons can be produced in the leaf, but the production requires oxygen. Emissions of methyl chloride from dry leaves can be significant for the global budget of methyl chloride.

Derendorp, Leonie; Holzinger, Rupert; Wishkerman, Asher; Keppler, Frank; Röckmann, Thomas

2010-05-01

115

Emissions of halogenated compounds in East Asia determined from measurements at Jeju Island, Korea.  

PubMed

High-frequency in situ measurements at Gosan (Jeju Island, Korea) during November 2007 to December 2008 have been combined with interspecies correlation analysis to estimate national emissions of halogenated compounds (HCs) in East Asia, including the chlorofluorocarbons (CFCs), halons, hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF(6)), and other chlorinated and brominated compounds. Our results suggest that overall China is the dominant emitter of HCs in East Asia, however significant emissions are also found in South Korea, Japan and Taiwan for HFC-134a, HFC-143a, C(2)F(6), SF(6), CH(3)CCl(3), and HFC-365mfc. The combined emissions of CFCs, halon-1211, HCFCs, HFCs, PFCs, and SF(6) from all four countries in 2008 are 25.3, 1.6, 135, 42.6, 3.6, and 2.0 kt/a, respectively. They account for approximately 15%, 26%, 29%, 16%, 32%, and 26.5% of global emissions, respectively. Our results show signs that Japan has successfully phased out CFCs and HCFCs in compliance with the Montreal Protocol (MP), Korea has started transitioning from HCFCs to HFCs, while China still significantly consumes HCFCs. Taiwan, while not directly regulated under the MP, is shown to have adapted the use of HFCs. Combined analysis of emission rates and the interspecies correlation matrix presented in this study proves to be a powerful tool for monitoring and diagnosing changes in consumption of HCs in East Asia. PMID:21649439

Li, Shanlan; Kim, Jooil; Kim, Kyung-Ryul; Mühle, Jens; Kim, Seung-Kyu; Park, Mi-Kyung; Stohl, Andreas; Kang, Dong-Jin; Arnold, Tim; Harth, Christina M; Salameh, Peter K; Weiss, Ray F

2011-07-01

116

[Elimination of volatile compounds of leaf tobacco from air emissions using biofiltration].  

PubMed

The composition of the volatile organic compounds (VOCs) of various leaf tobacco brands and their blends has been studied. The differences in the content of nicotine, solanone, tetramethyl hexadecenol, megastigmatrienones, and other compounds, determining the specific tobacco smell, have been revealed. A microbial consortium, which is able to deodorize simulated tobacco emissions and decompose nicotine, has been formed by long-term adaptation to the VOCs of tobacco leaves in a laboratory reactor, functioning as a trickle-bed biofilter. Such a biofilter eliminates 90% of the basic toxic compound (nicotine) and odor-active compounds; the filtration efficiency does not change for tobacco brands with different VOC concentrations or in the presence of foreign substances. The main strains, isolated from the formed consortium and participating in the nicotine decomposition process, belong to the genera Pseudomonas, Bacillus, and Rhodococcus. An examination of the biofilter trickling fluid has shown full decomposition of nicotine and odor-active VOCs. The compounds, revealed in the trickling fluid, did not have any odor and were nontoxic. The obtained results make it possible to conduct scaling of the biofiltration process to eliminate odor from air emissions in the tobacco industry. PMID:23035576

Zagustina, N A; Misharina, T A; Vepritski?, A A; Zhukov, V G; Ruzhitski?, A O; Terenina, M B; Krikunova, N I; Kulikova, A K; Popov, V O

2012-01-01

117

Electron emission from discontinuous gold-carbon compound film on etched porous aluminum oxide  

NASA Astrophysics Data System (ADS)

An electron emitter composed of discontinuous gold-carbon compound conducting film on etched porous aluminum oxide (PAO) layer is proposed in this letter. The PAO layer is located between two 30 ?m spaced cathode and grid electrode, and is etched in diluted phosphoric acid to introduce roughness on the soda lime glass surface and enhance discontinuity of the conducting film. Electron emission with good uniformity and stability is reproducibly obtained. The electron emission efficiency is higher than 2% at an anode voltage of 3 kV.

Wang, Zengmei; Li, Dejie; Yao, Baolun; Wang, Jian

2006-08-01

118

Effect of arsenic compounds on Vibrio fischeri light emission and butyrylcholinesterase activity  

Microsoft Academic Search

The effect of organic arsenic compounds and inorganic As(V) and As(III) on Vibrio fischeri luminescence and butyrylcholinesterase activity were evaluated using Microtox and microcalorimetric analysis. Organic arsenic\\u000a compounds were arsenocholine (AsC), arsenobetaine (AsB), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA) and the\\u000a antibiotic 4-hydroxy-3-nitrobenzene arsonic acid (HNAA, Roxarsone(R)). HNAA, As(III) and As(V) were found to inhibit Vibrio fischeri light emission whereas

E. Fulladosa; J. Debord; I. Villaescusa; J. C. Bollinger; J. C. Murat

2007-01-01

119

Determination of n-butylated trialkyllead compounds by gas chromatography with microwave plasma emission detection  

SciTech Connect

An analytical gas chromatographic procedure is described for the determination of trialkyllead compounds in aqueous media. The analyte compounds are extracted into benzene from an aqueous solution saturated with sodium chloride. They are then quantitatively converted into n-butyltrialkyllead derivatives by reaction with an n-butyl Grignard reagent. Precolumn Tenax trap enrichment of the derived trialkylbutylleads enables determination to low parts per billion levels to be carried out. Also investigated are extraction efficiencies and injection split ratios onto a fused silica capillary column. Lead specific detection is by atmospheric pressure microwave induced plasma spectrometric emission. Data are presented for a wastewater effluent sample. 3 figures.

Estes, S.A.; Uden, P.C.; Barnes, R.M.

1982-12-01

120

Determination of n-butylated trialkyllead compounds by gas chromatography with microwave plasma emission detection  

SciTech Connect

An analytical gas chromatographic procedure is described for the determination of trialkyllead compounds in aqueous media. The analyte compounds are extracted into benzene from an aqueous solution saturated with sodium chloride. They are then quantitatively converted into n-butyltrialkyllead derivatives by reaction with an n-butyl Grignard reagent. Precolumn Tenax trap enrichment of the derived trialkylbutylleads enables determination to low ppB levels to be carried out. Also investigated are extraction efficiencies and injection split ratios onto a fused silica capillary column. Lead specific detection is by atmospheric pressure microwave induced plasma spectrometric emission. Data are presented for a wastewater effluent sample. 21 references, 3 figures.

Estes, S.A.; Uden, P.C.; Barnes, R.M.

1982-12-01

121

Modelling of emission of volatile organic compounds from building materials—estimation of gas-phase mass transfer coefficient  

Microsoft Academic Search

A mathematical model is developed to predict Volatile Organic Compound (VOC) emission rates from homogeneous materials. The model considers both mass diffusion and mass convection processes in the boundary layer between the material surface and the air flow. Establishing the relationship between the surface air flow and emission rate; the model, therefore can predict the material emission rate under different

Fariborz Haghighat; Ying Zhang

1999-01-01

122

An improved model for estimating emissions of volatile organic compounds from forests in the eastern United States  

Microsoft Academic Search

Regional estimates of biogenic volatile organic compound (BVOC) emissions are important inputs for models of atmospheric chemistry and carbon budgets. Since forests are the primary emitters of BVOCs, it is important to develop reliable estimates of their areal coverage and BVOC emission rate. A new system is developed to estimate these emissions for specific tree genera at hourly and county

Christopher D. Geron; Alex B. Guenther; Thomas E. Pierce

1994-01-01

123

Variable emissions of microbial volatile organic compounds (MVOCs) from root-associated fungi isolated from Scots pine  

Microsoft Academic Search

Soils emit a large variety of volatile organic compounds. In natural ecosystems, measurements of microbial volatile organic compound (MVOC) exchange rates between soil and atmosphere are difficult due to e.g. the spatial heterogeneity of the belowground organisms, and due to the many potential sources for the same compounds. We measured in laboratory conditions the MVOC emission rates and spectra of

Jaana Bäck; Hermanni Aaltonen; Heidi Hellén; Maija K. Kajos; Johanna Patokoski; Risto Taipale; Jukka Pumpanen; Jussi Heinonsalo

2010-01-01

124

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

125

Emission rates of selected volatile organic compounds and formaldehyde in newly constructed apartment  

Microsoft Academic Search

Since volatile organic compounds (VOCs) and formaldehyde (HCHO) associates with building and finishing materials such as paints,\\u000a varnishes, and adhesives, the emission rates of VOCs and HCHO in indoor environments of newly constructed apartment according\\u000a to floor levels were estimated using mass balance model. Mean indoor concentrations of benzene, toluene, styrene, and HCHO\\u000a in middle floors were higher than those

Sanghyo Sim; Jeongsuk Moon; Yoonshin Kim; Junghee Tae

2010-01-01

126

Emissions of non-methane organic compounds and carbon dioxide from forest floor cores  

Microsoft Academic Search

Forest floor emissions of CO[sub 2] and non-methane volatile organic compounds (NMOCs) were measured to determine their contribution to C losses from forests. Forest floor cores 19 cm in diameter and approximately 10 cm deep were obtained from beneath loblolly pine (Pinus taeda L), oak-maple (Quercus-Acer), and yellow-poplar (Liriodendron tulipifera L) trees on the Walker Branch Watershed, Oak Ridge, TN.

P. J. Hanson; W. A. Hoffman

2009-01-01

127

Carbonyl Compounds and Toxicity Assessments of Emissions from a Diesel Engine Running on Biodiesels  

Microsoft Academic Search

This study elucidates the effect of biodiesel on the emission of carbonyl compounds generated from a diesel engine (generator), and the related biotoxicity characteristics. The Microtox test and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay were conducted to evaluate the acute toxicity and cytotoxicity, respectively, of gaseous extracts from diesel engine exhaust. The engine was tested using diesel fuel and biodiesel blends (10,

Yu-Yin Liu; Ta-Chang Lin; Ying-Jan Wang; Wei-Lun Ho; John Koupal; Fred Minassian; Hannah Murray; Mani Natarajan; Fenfen Zhu; Masaki Takaoka; Kazuyuki Oshita; Shinsuke Morisawa; Hiroshi Tsuno; Yoshinori Kitajima; Wan-Fu Chiang; Hung-Yuan Fang; Chao-Hsiung Wu; Chang-Jun Huang; Ching-Yuan Chang; Yu-Min Chang; Ching-Liang Chen; Anders Nielsen; Lars Nielsen; Anders Feilberg; Knud Christensen; Janet Yanowitz; Robert McCormick; Lei Yu; Shichen Jia; Qinyi Shi; Tsang-Jung Chang; Hong-Ming Kao; Yu-Ting Wu; Wei-Hua Huang; Patrick Goodman; David Rich; Ariana Zeka; Luke Clancy; Douglas Dockery; Thomas Lavery; Christopher Rogers; Ralph Baumgardner; Kevin Mishoe; Wei-Chin Chen; Hsun-Yu Lin; Chung-Shin Yuan; Chung-Hsuang Hung; Li He; Guo Huang; Guangming Zeng; Hongwei Lu

2009-01-01

128

A Study on Dynamic Volatile Organic Compound Emission Characterization of Water-Based Paints  

Microsoft Academic Search

Volatile organic compounds (VOCs) emitted from surface coatings have caused growing public concern for air quality. Even the low-emitted VOC impact from water-based paints on indoor air quality in urban areas has caused concern. This paper presents experimental data using a mathematical model to simulate dynamic VOC emissions from water-based paints that is based on mass transfer and molecular diffusion

Yu-Min Chang; Wei-Hsing Hu; Wen-Bing Fang; Shiao-Shing Chen; Chang-Tang Chang; Hsiao-Wei Ching

2011-01-01

129

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

130

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

131

Emissions of volatile organic compounds from cut grass and clover are enhanced during the drying process  

NASA Astrophysics Data System (ADS)

The release of volatile organic compounds (VOCs) by drying grass and clover leaves and stems was studied in the laboratory using proton-transfer chemical-ionization mass spectrometry, which enables the simultaneous, on-line monitoring of VOC concentrations. A burst of VOC emissions due to cutting the leaves and stems was followed by a second, more intense emission lasting for several hours when the vegetation was starting to dry out. In addition to (Z)-3-hexenal, (Z)-3-hexenol, and hexenyl acetate, that were emitted by the plant tissue in response to the wounding, enhanced emissions of methanol, acetaldehyde, acetone, butanone, and possibly formaldehyde were observed. These findings may have important implications for regional air quality in agricultural and urban areas.

de Gouw, Joost A.; Howard, Carleton J.; Custer, Thomas G.; Fall, Ray

132

[Preliminary study concerning emissions of the volatile organic compounds from cooking oils].  

PubMed

Cooking oil fume is one of the important sources of atmospheric volatile organic compounds (VOCs), which are the key precursors of ozone and secondary organic aerosols in air. In this study, the production of cooking oil fume was simulated by heating typical pure vegetable oils (peanut oil, sunflower oil, soybean oil, olive oil and blend oil) at different temperatures in beakers to investigate the VOCs emission characteristics. The emitted VOCs were sampled with a Tenax adsorption tube and analyzed using GC-MS after thermal desorption. The results showed that the emission of VOCs increased with the increase of the heating temperature for all the investigated cooking oils, and at a given temperature, the blend oil emitted the lowest amount of VOCs. The VOCs emission intensity at different heating temperatures fitted well with binomial equations and ranged from 1.6-11.1 mg x (kg x min)(-1). PMID:23243847

He, Wan-Qing; Tian, Gang; Nie, Lei; Qu, Song; Li, Jing; Wang, Min-Yan

2012-09-01

133

Emissions of oxygenated volatile organic compounds from open crop burning in Yangtze River Delta region, China  

NASA Astrophysics Data System (ADS)

Measurements of volatile organic compounds (VOCs) were made by gas chromatography/flame ionization detection/mass spectrometry (GC/FID/MS) and proton transfer reaction-mass spectrometry (PTR-MS) at Rudong, a rural area of Central East China in June 2010. During the campaign we identified several plumes originated from open biomass burning by the simultaneous enhancements of carbon monoxide and acetonitrile. Based on positive matrix factorization (PMF) analysis, the contribution of biomass burning was in the range from 60 to 80% for the plumes. We found that oxygenated VOCs were predominant for these events. The emission ratios of OVOCs to CO for open crop burnings derived in this work were found to be high. Combined with the updated CO emissions of 12.7 Tg per year from crop burning, we estimated OVOC emissions from crop burning can be about 1.2 Tg per year, accounting for substantial amount of VOCs emitted from crop burning.

Tanimoto, H.; Kudo, S.; Pan, X.; Inomata, S.; Saito, S.; Kanaya, Y.; Wang, Z.

2013-12-01

134

High-resolution X-ray emission spectroscopy of molybdenum compounds.  

PubMed

High-resolution molybdenum K-edge X-ray emission spectroscopy (XES) was used to characterize the K beta(4) and K beta' ' valence-to-core transition bands in the oxo-Mo compounds K(2)MoO(4), MoO(S(2)CNEt(2))(2), and MoO(2)(S(2)CNEt(2))(2). The K beta(4) and K beta' ' emission bands are attributed to transitions to the Mo 1s core hole from molecular orbitals possessing primarily molybdenum 4d and oxygen 2s character, respectively. This communication describes the first assignment of the K beta' ' interatomic band in the emission spectra of molybdenum complexes. Additionally, the K beta(4) and K beta' 'transitions are shown to be sensitive to the chemical and electronic environment of the metal, suggesting that high-resolution XES might be an effective method for elucidating the nature of the molybdenum centers in biological systems. PMID:15819540

Doonan, Christian J; Zhang, Limei; Young, Charles G; George, Simon J; Deb, Aniruddha; Bergmann, Uwe; George, Graham N; Cramer, Stephen P

2005-04-18

135

Development of a material with reproducible emission of selected volatile organic compounds - ?-Chamber study.  

PubMed

Volatile organic compounds (VOCs) found indoors have the potential to affect human health. Typical sources include building materials, furnishings, cleaning agents, etc. To address this risk, chemical emission testing is used to assess the potential of different materials to pollute indoor air. One objective of the European Joint Research Project "MACPoll" (Metrology for Chemical Pollutants in Air) aims at developing and testing a reference material for the quality control of the emission testing procedure. Furthermore, it would enable comparison of measurement results between test laboratories. The heterogeneity of the majority of materials makes it difficult to find a suitable reference sample. In the present study, styrene, 2-ethyl-1-hexanol, N-methyl-?-pyrrolidone, lindane, n-hexadecane, 1,2-dimethyl- and 1,2-di-n-butyl-phthalate were added to 12 commercially available lacquers (6 alkyd and 6 acrylic polymer based lacquers) serving as carrier substrate. After homogenization, the mixtures were loaded into a Markes Micro-Chamber/Thermal Extractor (?-CTE™) for curing and investigation of the emission behavior for each compound. For almost all of the investigated chemicals, the preferred glossy acrylic lacquer showed emissions that were reproducible with a variation of less than 20% RSD. Such lacquer systems have therefore been shown to be good candidates for use as reference materials in inter-laboratory studies. PMID:24418066

Nohr, Michael; Horn, Wolfgang; Wiegner, Katharina; Richter, Matthias; Lorenz, Wilhelm

2014-07-01

136

Behavior of VOCs and Carbonyl Compounds Emission from Different Types of Wallpapers in Korea  

PubMed Central

Emissions of volatile organic compounds (VOCs) and carbonyls from three types of commercially available wallpapers (i.e., PVC-coated, paper-backed, natural material-coated) in Korea were evaluated using a 20 L small chamber. A total of 332 products were tested for emission factors, frequencies of occurrence and composition ratios. Toluene and formaldehyde concentrations were below Korean standard values for all products; however, the total VOC (TVOC) concentrations exceeded current standards (4.0 mg/m2·h) for 30 products. The TVOC emission factor for PVC-coated wallpapers, for which polymer materials are used in the manufacturing process, was seven and 16 times higher than those of paper-backed and natural material-coated wallpapers, respectively. The detection frequencies for toluene and formaldehyde were the highest (82.5%) and fourth highest (79.5%), respectively among the 50 target chemical species. The composition ratios for BTEX ranged from 0.3% to 5.1% and unidentified VOCs, which were not qualitatively analyzed using standard gas methods, ranged from 90.2% to 94.8%. Among six carbonyl compounds (acrolein was not detected in any type of wallpaper), acetone had the highest concentrations in PVC-coated (44.6%) and paper-backed (66.6%) wallpapers. Formaldehyde emissions were highest (64.6%) for natural material-coated wallpapers, a result of the formaldehyde-based resin used in the manufacturing process for these products.

Lim, Jungyun; Kim, Suejin; Kim, ARong; Lee, Wooseok; Han, Jinseok; Cha, Jun-Seok

2014-01-01

137

Behavior of VOCs and carbonyl compounds emission from different types of wallpapers in Korea.  

PubMed

Emissions of volatile organic compounds (VOCs) and carbonyls from three types of commercially available wallpapers (i.e., PVC-coated, paper-backed, natural material-coated) in Korea were evaluated using a 20 L small chamber. A total of 332 products were tested for emission factors, frequencies of occurrence and composition ratios. Toluene and formaldehyde concentrations were below Korean standard values for all products; however, the total VOC (TVOC) concentrations exceeded current standards (4.0 mg/m²·h) for 30 products. The TVOC emission factor for PVC-coated wallpapers, for which polymer materials are used in the manufacturing process, was seven and 16 times higher than those of paper-backed and natural material-coated wallpapers, respectively. The detection frequencies for toluene and formaldehyde were the highest (82.5%) and fourth highest (79.5%), respectively among the 50 target chemical species. The composition ratios for BTEX ranged from 0.3% to 5.1% and unidentified VOCs, which were not qualitatively analyzed using standard gas methods, ranged from 90.2% to 94.8%. Among six carbonyl compounds (acrolein was not detected in any type of wallpaper), acetone had the highest concentrations in PVC-coated (44.6%) and paper-backed (66.6%) wallpapers. Formaldehyde emissions were highest (64.6%) for natural material-coated wallpapers, a result of the formaldehyde-based resin used in the manufacturing process for these products. PMID:24747540

Lim, Jungyun; Kim, Suejin; Kim, Arong; Lee, Wooseok; Han, Jinseok; Cha, Jun-Seok

2014-04-01

138

Emission of volatile sulfur compounds during composting of municipal solid waste (MSW).  

PubMed

Volatile sulfur compounds (VSCs) are the main source for malodor from composting plants. In this study, the VSCs generated from composting of 15-80 mm municipal solid waste (T0), kitchen waste (T1) and kitchen waste mixed dry cornstalks (T2) were measured in 60 L reactors with forced aeration for a period of 30 days. The VSCs detected in all treatments were hydrogen sulfide (H2S), methyl mercaptan (MM), dimethyl sulfide (DMS), carbon bisulfide (CS2) and dimethyl disulfide (DMDS). Over 90% of the VSCs emissions occurred during the first 15 days, and reached their peak values at days 4-7. The emission profiles of five VSCs species were significantly correlated with internal materials temperature and outlet O2 concentration (p<0.05). Total emissions of the VSCs were 216.1, 379.3 and 126.0 mg kg(-1) (dry matter) for T0, T1 and T2, respectively. Among the five VSCs, H2S was the most abundant compound with 39.0-43.0% of total VSCs released. Composting of kitchen waste from separate collection posed a negative influence on the VSC and leachate production because of its high moisture content. An addition of dry cornstalks at a mixing ratio of 4:1 (wet weight) could significantly reduce the VSCs emissions and avoid leachate. Compared to pure kitchen waste, VSCs were reduced 66.8%. PMID:23312132

Zhang, Hongyu; Schuchardt, Frank; Li, Guoxue; Yang, Jinbing; Yang, Qingyuan

2013-04-01

139

Emission rates of selected volatile organic compounds from skin of healthy volunteers.  

PubMed

Gas chromatography with mass spectrometric detection (GC-MS) coupled with solid phase micro-extraction as pre-concentration method (SPME) was applied to identify and quantify volatile organic compounds (VOCs) emitted by human skin. A total of 64 C4-C10 compounds were quantified in skin emanation of 31 healthy volunteers. Amongst them aldehydes and hydrocarbons were the predominant chemical families with eighteen and seventeen species, respectively. Apart from these, there were eight ketones, six heterocyclic compounds, six terpenes, four esters, two alcohols, two volatile sulphur compounds, and one nitrile. The observed median emission rates ranged from 0.55 to 4,790 fmol cm(-2)min(-1). Within this set of analytes three volatiles; acetone, 6-methyl-5-hepten-2-one, and acetaldehyde exhibited especially high emission rates exceeding 100 fmol cm(-2)min(-1). Thirty-three volatiles were highly present in skin emanation with incidence rates over 80%. These species can be considered as potential markers of human presence, which could be used for early location of entrapped victims during Urban Search and Rescue Operations (USaR). PMID:24768920

Mochalski, Pawe?; King, Julian; Unterkofler, Karl; Hinterhuber, Hartmann; Amann, Anton

2014-05-15

140

Emission rates of selected volatile organic compounds from skin of healthy volunteers  

PubMed Central

Gas chromatography with mass spectrometric detection (GC–MS) coupled with solid phase micro-extraction as pre-concentration method (SPME) was applied to identify and quantify volatile organic compounds (VOCs) emitted by human skin. A total of 64 C4-C10 compounds were quantified in skin emanation of 31 healthy volunteers. Amongst them aldehydes and hydrocarbons were the predominant chemical families with eighteen and seventeen species, respectively. Apart from these, there were eight ketones, six heterocyclic compounds, six terpenes, four esters, two alcohols, two volatile sulphur compounds, and one nitrile. The observed median emission rates ranged from 0.55 to 4790 fmol cm?2 min?1. Within this set of analytes three volatiles; acetone, 6-methyl-5-hepten-2-one, and acetaldehyde exhibited especially high emission rates exceeding 100 fmol cm?2 min?1. Thirty-three volatiles were highly present in skin emanation with incidence rates over 80%. These species can be considered as potential markers of human presence, which could be used for early location of entrapped victims during Urban Search and Rescue Operations (USaR).

Mochalski, Pawel; King, Julian; Unterkofler, Karl; Hinterhuber, Hartmann; Amann, Anton

2014-01-01

141

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

142

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

143

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

144

Ozone formation potentials of organic compounds from different emission sources in the South Coast Air Basin of California  

NASA Astrophysics Data System (ADS)

Different organic compounds exhibit different propensities for ozone formation. Two approaches were used to study the ozone formation potentials or source reactivities of different anthropogenic organic compounds emission categories in California's South Coast Air Basin (SoCAB). The first approach was based on the combination of total organic gases (TOG) emission speciation profiles and the maximum incremental reactivity (MIR) scale of organic species. The second approach quantified ozone impacts from different emission sources by performing 3-dimensional air quality model sensitivity analysis involving increased TOG emissions from particular sources. The source reactivities derived from these two approaches agree reasonably well for 58 anthropogenic organic compounds emission categories in the SoCAB. Both approaches identify TOG emissions from mobile sources as having the highest reactivity. Source reactivities from both approaches were also combined with TOG emissions from each source category to produce a 2005 reactivity-based anthropogenic TOG emission inventory for the SoCAB. The top five reactivity-based anthropogenic TOG emission sources in the SoCAB during 2005 were: light-duty passenger cars, off-road equipment, consumer products, light-duty trucks category 2 (i.e., 3751-5750 lb), and recreational boats. This is in contrast to the mass-based TOG emission inventory, which indicates that livestock waste and composting emission categories were two of the five largest mass-based anthropogenic TOG emission sources. The reactivity-based TOG emission inventory is an important addition to the mass-based TOG emission inventory because it represents the ozone formation potentials from emission sources and can be used to assist in determining targeted sources for developing organic compounds reduction policies.

Chen, Jianjun; Luo, Dongmin

2012-08-01

145

On-road emission measurements of reactive nitrogen compounds from three California cities.  

PubMed

The three California cities of San Jose, Fresno, and West Los Angeles (wLA) were visited during March 2008 to collect on-road emission measurements of reactive nitrogen compounds from light-duty vehicles. At the San Jose and wLA sites, comparison with historical measurements showed that emissions of carbon monoxide (CO), hydrocarbons (HC), and nitric oxide (NO) continue to decrease in the on-road fleet, yet the ratio of nitrogen dioxide (NO(2)) to NO in new diesel vehicles appears to be undergoing large increases. A small fleet of 2007 diesel ambulances measured in Fresno was found to have more than 60% of their emitted oxides of nitrogen as NO(2). Ammonia (NH(3)) emissions are shown to have a strong dependence on model year and vehicle specific power. NH(3) means are 0.49 +/- 0.02, 0.49 +/- 0.01, and 0.79 +/- 0.02 g/kg of fuel for San Jose, Fresno, and wLA, respectively, with the larger emissions at the wLA site likely due to driving mode. NH(3) at these locations was found to account for 25%, 22%, and 27% of the molar fixed nitrogen emissions, respectively. Using these mean values to construct a national fuel-based NH(3) inventory results in a range of 210000 to 330000 short tons of NH(3) annually from light-duty vehicles. PMID:20380434

Bishop, Gary A; Peddle, Allison M; Stedman, Donald H; Zhan, Tao

2010-05-01

146

Semivolatile and volatile organic compound emissions from wood-fired hydronic heaters.  

PubMed

Emissions including polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), polyaromatic hydrocarbons (PAHs), and volatile organic compounds (VOCs), were sampled from different wood-fired hydronic heater (HH) technologies. Four commercially available HH technologies were studied: a single-stage conventional combustor with natural updraft, a three-stage downdraft combustion system, a bottom-fed pellet burner, and a two-stage heater with both a combustion and gasification chamber. The fuel consisted of three wood types (red oak, white pine, and white ash), one hardwood pellet brand, and one fuel mixture containing 95% red oak and 5% residential refuse by weight. The various HHs and fuel combinations were tested in a realistic homeowner fuel-charging scenario. Differences in emission levels were found between HH technologies and fuel types. PCDD/PCDF emissions ranged from 0.004 to 0.098 ng toxic equivalency/MJ(input) and PAHs from 0.49 to 54 mg/MJ(input). The former was increased by the presence of 5% by weight refuse. The white pine fuel had the highest PAH emission factor, while the bottom fed pellet burner had the lowest. The major VOCs emitted were benzene, acetylene, and propylene. The highest emissions of PAHs, VOCs, and PCDDs/PCDFs were observed with the conventional unit, likely due to the rapid changes in combustion conditions effected by the damper opening and closing. PMID:22765760

Aurell, Johanna; Gullett, Brian K; Tabor, Dennis; Touati, Abderrahmane; Oudejans, Lukas

2012-07-17

147

Variable emissions of microbial volatile organic compounds (MVOCs) from root-associated fungi isolated from Scots pine  

NASA Astrophysics Data System (ADS)

Soils emit a large variety of volatile organic compounds. In natural ecosystems, measurements of microbial volatile organic compound (MVOC) exchange rates between soil and atmosphere are difficult due to e.g. the spatial heterogeneity of the belowground organisms, and due to the many potential sources for the same compounds. We measured in laboratory conditions the MVOC emission rates and spectra of eight typical fungi occurring in boreal forest soils. The studied species are decomposers ( Gymnopilus penetrans, Ophiostoma abietinum), ectomycorrhizal ( Cenococcum geophilum, Piloderma olivaceum, Suillus variegatus, Tomentellopsis submollis) and endophytic fungi ( Meliniomyces variabilis, Phialocephala fortinii). The MVOC emissions contained altogether 21 known and 6 unidentified compounds whose emission rates were >0.1 ?g g(DW) -1 h -1. The most abundant compounds were the short-chain carbonyl compounds (acetone and acetaldehyde). The greatest carbonyl emissions were measured from P. olivaceum (1.9 mg acetone g(DW) -1 h -1) and P. fortinii (0.114 mg acetaldehyde g(DW) -1 h -1). Terpenoid emissions (isoprene, mono- and sesquiterpenes) were detected from some fungal cultures, but in relatively small amounts. We conclude that soil micro-organisms can potentially be responsible for significant emissions of volatiles, especially short-chain oxygenated compounds, to the below-canopy atmosphere.

Bäck, Jaana; Aaltonen, Hermanni; Hellén, Heidi; Kajos, Maija K.; Patokoski, Johanna; Taipale, Risto; Pumpanen, Jukka; Heinonsalo, Jussi

2010-09-01

148

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

149

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

150

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

2013-11-01

151

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

152

Volatile organic compound emission rates from mixed deciduous and coniferous forests in Northern Wisconsin, USA  

NASA Astrophysics Data System (ADS)

Biogenic emissions of volatile organic compounds (VOC) from forests play an important role in regulating the atmospheric trace gas composition including global tropospheric ozone concentrations. However, more information is needed on VOC emission rates from different forest regions of the world to understand regional and global impacts and to implement possible mitigation strategies. The mixed deciduous and coniferous forests of northern Wisconsin, USA, were predicted to have significant VOC emission rates because they are comprised of many genera (i.e. Picea, Populus, Quercus, Salix) known to be high VOC emitters. In July 1993, a study was conducted on the Chequamegon National Forest near Rhinelander, WI, to identify and quantify VOC emitted from major trees, shrubs, and understory herbs in the mixed northern forests of this region. Emission rates were measured at various scales - at the leaf level with cuvettes, the branch level with branch enclosures, the canopy level with a tower based system, and the landscape level with a tethered balloon air sampling system. Area-average emission rates were estimated by scaling, using biomass densities and species composition along transects representative of the study site. Isoprene (C 5H 8) was the primary VOC emitted, although significant quantities of monoterpenes (C 10H 16) were also emitted. The highest emission rates of isoprene (at 30°C and photosynthetically active radiation of 1000 ?mol m -2 s -1) were from northern red oak ( Quercus rubra, >110 ?g(C) g -1 h -1); aspen ( Populus tremuloides, >77); willow ( Salix spp., >54); and black spruce ( Picea mariana, >10). Emission rates of hybrid poplar clones ranged from 40 to 90 ?g(C) g -1 h -1 at 25°C; those of Picea provenances were generally <10, and emission rates of a hybrid between North American and European spruces were intermediate to parental rates. More than 30 species of plants were surveyed from the sites, including several from previously unstudied genera such as Alnus, Chamaedaphne, Ledum, Tilia, Rubus, and Sphagnum. Based on the measured isoprene concentrations in the daytime atmospheric surface layer and mixed layer, area-averaged fluxes of isoprene were estimated to be about 1 mg(C) m -2 h -1. This estimate agrees reasonably well with model predictions. Our results indicate that mixed forests in the Lake States region of the USA are a significant source of reactive VOC to the atmosphere. Accurate estimates of these emissions are required for determining appropriate regulatory air pollution control strategies. Future studies are needed to extrapolate these estimates to other landscapes and to better understand the factors controlling observed variations in VOC emissions.

Isebrands, J. G.; Guenther, A. B.; Harley, P.; Helmig, D.; Klinger, L.; Vierling, L.; Zimmerman, P.; Geron, C.

153

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...

154

Control of Volatile Organic Compound Emissions from Volatile Organic Liquid Storage in Floating and Fixed Roof Tanks. Guideline Series.  

National Technical Information Service (NTIS)

Control Techniques Guidelines (CTG) are documents prepared by the EPA that serve as guidance to States in developing reasonably available control technology (RACT). The CTG's contain volatile organic compound (VOC) emissions and control technology informa...

1993-01-01

155

Characteristics of volatile organic compounds emission profiles from hot road bitumens.  

PubMed

A procedure for the investigation and comparison of volatile organic compounds (VOCs) emission profiles to the atmosphere from road bitumens with various degrees of oxidation is proposed. The procedure makes use of headspace analysis and gas chromatography with universal as well as selective detection, including gas chromatography-mass spectrometry (GC-MS). The studies revealed that so-called vacuum residue, which is the main component of the charge, contains variable VOC concentrations, from trace to relatively high ones, depending on the extent of thermal cracking in the boiler of the vacuum distillation column. The VOC content in the oxidation product, so-called oxidized paving bitumen, is similarly varied. There are major differences in VOC emission profiles between vacuum residue and oxidized bitumens undergoing thermal cracking. The VOC content in oxidized bitumens, which did not undergo thermal cracking, increases with the degree of oxidation of bitumens. The studies revealed that the total VOC content increases from about 120ppm for the raw vacuum residue to about 1900ppm for so-called bitumen 35/50. The amount of volatile sulfur compounds (VSCs) in the volatile fraction of fumes of oxidized bitumens increases with the degree of oxidation of bitumen and constitutes from 0.34% to 3.66% (w/w). The contribution of volatile nitrogen compounds (VNCs) to total VOC content remains constant for the investigated types of bitumens (from 0.16 to 0.28% (w/w) of total VOCs). The results of these studies can also find use during the selection of appropriate bitumen additives to minimize their malodorousness. The obtained data append the existing knowledge on VOC emission from oxidized bitumens. They should be included in reports on the environmental impact of facilities in which hot bitumen binders are used. PMID:24875867

Boczkaj, Grzegorz; Przyjazny, Andrzej; Kami?ski, Marian

2014-07-01

156

Gas phase carbonyl compounds in ship emissions: Differences between diesel fuel and heavy fuel oil operation  

NASA Astrophysics Data System (ADS)

Gas phase emission samples of carbonyl compounds (CCs) were collected from a research ship diesel engine at Rostock University, Germany. The ship engine was operated using two different types of fuels, heavy fuel oil (HFO) and diesel fuel (DF). Sampling of CCs was performed from diluted exhaust using cartridges and impingers. Both sampling methods involved the derivatization of CCs with 2,4-Dinitrophenylhydrazine (DNPH). The CCs-hydrazone derivatives were analyzed by two analytical techniques: High Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD) and Gas Chromatography-Selective Ion Monitoring-Mass Spectrometry (GC-SIM-MS). Analysis of DNPH cartridges by GC-SIM-MS method has resulted in the identification of 19 CCs in both fuel operations. These CCs include ten aliphatic aldehydes (formaldehyde, acetaldehyde, propanal, isobutanal, butanal, isopentanal, pentanal, hexanal, octanal, nonanal), three unsaturated aldehydes (acrolein, methacrolein, crotonaldehyde), three aromatic aldehyde (benzaldehyde, p-tolualdehyde, m,o-molualdehyde), two ketones (acetone, butanone) and one heterocyclic aldehyde (furfural). In general, all CCs under investigation were detected with higher emission factors in HFO than DF. The total carbonyl emission factor was determined and found to be 6050 and 2300 ?g MJ-1 for the operation with HFO and DF respectively. Formaldehyde and acetaldehyde were found to be the dominant carbonyls in the gas phase of ship engine emission. Formaldehyde emissions factor varied from 3500 ?g MJ-1 in HFO operation to 1540 ?g MJ-1 in DF operation, which is 4-30 times higher than those of other carbonyls. Emission profile contribution of CCs showed also a different pattern between HFO and DF operation. The contribution of formaldehyde was found to be 58% of the emission profile of HFO and about 67% of the emission profile of DF. Acetaldehyde showed opposite behavior with higher contribution of 16% in HFO compared to 11% for DF. Heavier carbonyls (more than two carbon atoms) showed also more contribution in the emission profile of the HFO fuel (26%) than in DF (22%).

Reda, Ahmed A.; Schnelle-Kreis, J.; Orasche, J.; Abbaszade, G.; Lintelmann, J.; Arteaga-Salas, J. M.; Stengel, B.; Rabe, R.; Harndorf, H.; Sippula, O.; Streibel, T.; Zimmermann, R.

2014-09-01

157

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

2010-08-01

158

Emissions of volatile organic compounds during the decomposition of plant litter  

NASA Astrophysics Data System (ADS)

Volatile organic compounds (VOCs) are emitted during plant litter decomposition, and such VOCs can have wide-ranging impacts on atmospheric chemistry, terrestrial biogeochemistry, and soil ecology. However, we currently have a limited understanding of the relative importance of biotic versus abiotic sources of these VOCs and whether distinct types of litter emit different types and quantities of VOCs during decomposition. We analyzed VOCs emitted by microbes or by abiotic mechanisms during the decomposition of litter from 12 plant species in a laboratory experiment using proton transfer reaction mass spectrometry (PTR-MS). Net emissions from litter with active microbial populations (non-sterile litters) were between 0 and 11 times higher than emissions from sterile controls over a 20-d incubation period, suggesting that abiotic sources of VOCs are generally less important than biotic sources. In all cases, the sterile and non-sterile litter treatments emitted different types of VOCs, with methanol being the dominant VOC emitted from litters during microbial decomposition, accounting for 78 to 99% of the net emissions. We also found that the types of VOCs released during biotic decomposition differed in a predictable manner among litter types with VOC profiles also changing as decomposition progressed over time. These results show the importance of incorporating both the biotic decomposition of litter and the species-dependent differences in terrestrial vegetation into global VOC emission models.

Gray, Christopher M.; Monson, Russell K.; Fierer, Noah

2010-09-01

159

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

160

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

161

Non-methane biogenic volatile organic compound emissions from boreal peatland microcosms under warming and water table drawdown  

Microsoft Academic Search

Boreal peatlands have significant emissions of non-methane biogenic volatile organic compounds (BVOCs). Climate warming is expected to affect these ecosystems both directly, with increasing temperature, and indirectly, through water table drawdown following increased evapotranspiration. We assessed the combined effect of warming and water table drawdown on the BVOC emissions from boreal peatland microcosms. We also assessed the treatment effects on

Patrick Faubert; Paivi Tiiva; Tchamga Achille Nakam; Jarmo K. Holopainen; Toini Holopainen; Riikka Rinnan

2011-01-01

162

Non-Methane Biogenic Volatile Organic Compound Emissions from a Subarctic Peatland Under Enhanced UV-B Radiation  

Microsoft Academic Search

Boreal and subarctic peatlands have been extensively studied for their major role in the global carbon balance. However, study efforts have so far neglected the contribution of these ecosystems to the non-methane biogenic volatile organic compound (BVOC) emissions, which are important in the atmospheric chemistry and feedbacks on climate change. We aimed at estimating the BVOC emissions from a subarctic

Patrick Faubert; Päivi Tiiva; A. Rinnan; J. Rasanen; Jarmo K. Holopainen; Toini Holopainen; E. Kyro; Riikka Rinnan

2010-01-01

163

MODEL FOR EVALUATION OF REFINERY AND SYNFUELS VOC (VOLATILE ORGANIC COMPOUNDS) EMISSION DATA. VOLUME 1. TECHNICAL REPORT AND APPENDIX A  

EPA Science Inventory

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 tw...

164

MODEL FOR EVALUATION OF REFINERY AND SYNFUELS VOC (VOLATILE ORGANIC COMPOUNDS) EMISSION DATA. VOLUME 2. APPENDICES B AND C  

EPA Science Inventory

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 tw...

165

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

166

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

167

Source location and characterization of volatile organic compound emissions at a petrochemical plant in Kaohsiung, Taiwan.  

PubMed

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 1 whole year. By consolidated into a database, the data could be readily retrieved, statistically analyzed, and clearly presented in both table and graph forms. It followed from the cross-analysis of the database that the abundant types of VOCs were alkanes, alkenes/dienes, and aromatics, all of which accounted for 99% of total VOCs. By contour plotting, the emission sources for alkanes, aromatics, and alkenes/ dienes were successfully located. Through statistical analysis, the database could provide the range and 90% confidence interval of each species from each emission source. Both alkanes and alkene/dienes came from tank farm and naphtha cracking units and were mainly composed of C3-C5 members. Regarding aromatics, benzene, toluene, and xylenes were the primary species; they were emitted from tank farm, aromatic units, and xylene units. PMID:16295274

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

2005-10-01

168

Emissions of volatile organic compounds and particulate matter from small-scale peat fires  

NASA Astrophysics Data System (ADS)

Air pollution emitted from peat fires can negatively impact regional air quality, visibility, climate, and human health. Peat fires can smolder over long periods of time and, therefore, can release significantly greater amounts of carbon into the atmosphere per unit area compared to burning of other types of biomass. However, few studies have characterized the gas and particulate emissions from peat burning. To assess the atmospheric impact of peat fires, particulate matter (PM) and volatile organic compounds (VOCs) were quantified from controlled small-scale peat fire experiments. Major carbon emissions (i.e. CO2, CO, methane and total hydrocarbons) were measured during the peat burn experiments. Speciated PM mass was also determined from the peat burns from filter and polyurethane foam samples. Whole air samples were taken in SUMMA canisters and analyzed by gas chromatography-mass spectrometry to measure 82 trace VOCs. Additional gaseous carbonyl species were measured by sampling with dinitrophenylhydrazine-coated cartridges and analyzed with high performance liquid chromatography. VOCs with highest observed concentrations measured from the peat burns were propylene, benzene, chloromethane and toluene. Gas-phase carbonyls with highest observed concentrations included acetaldehyde, formaldehyde and acetone. Emission factors of major pollutants will be compared with recommended values for peat and other biomass burning.

George, I. J.; Black, R.; Walker, J. T.; Hays, M. D.; Tabor, D.; Gullett, B.

2013-12-01

169

Abiotic emissions of methane and reduced organic compounds from organic matter  

NASA Astrophysics Data System (ADS)

Recent laboratory studies show that the important greenhouse gas methane, but also other reduced atmospheric trace gases, can be emitted by abiotic processes from organic matter, such as plants, pure organic compounds and soils. It is very difficult to distinguish abiotic from biotic emissions in field studies, but in laboratory experiments this is easier because it is possible to carefully prepare/sterilize samples, or to control external parameters. For example, the abiotic emissions always show a strong increase with temperature when temperatures are increased to 70C or higher, well above the temperature optimum for bacterial activity. UV radiation has also been clearly shown to lead to emission of methane and other reduced gases from organic matter. Interesting information on the production mechanism has been obtained from isotope studies, both at natural abundance and with isotope labeling. For example, the methoxyl groups of pectin were clearly identified to produce methane. However, analysis of the isotopic composition of methane from natural samples clearly indicates that there must be other molecular mechanisms that lead to methane production. Abiotic methane generation could be a ubiquitous process that occurs naturally at low rates from many different sources.

Roeckmann, T.; Keppler, F.; Vigano, I.; Derendorp, L.; Holzinger, R.

2012-12-01

170

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

171

GLOBal Organic Emissions NETwork (GLOBOENET) tools and strategies for quantifying canopy-scale biogenic volatile organic compound emissions (Invited)  

NASA Astrophysics Data System (ADS)

The first efforts to estimate global biogenic volatile organic compound (BVOC) emissions were conducted about 50 years ago. These initial BVOC emission estimates were based solely on enclosure measurements but were soon followed in the 1970s by the first successful attempts to measure canopy-scale BVOC fluxes using micrometeorological flux measurement techniques. Above canopy flux measurements have now been applied in many different landscapes but nearly all of these studies are short term observations that are not readily available which has limited their use in model development and evaluation. This is in contrast to the community that is measuring exchanges of carbon dioxide (CO2), water vapor, and energy which has established a number of regional networks which comprise the global FLUXNET network. This network has allowed the testing of both models and satellite-derived methods of estimating surface exchanges over a variety of ecosystems and over long temporal scalesThis global network of micrometeorological tower sites also provides an opportunity to establish networks for investigating exchanges of other constituents that are exchanged between terrestrial ecosystems and the atmosphere. We have initiated a community activity, called GLOBOENET, to facilitate and coordinate efforts to measure BVOC fluxes at micrometeorological tower sites. This effort includes 1) PTRMS based eddy covariance systems that can be used to quantify fluxes of a large number of BVOC at selected locations and 2)low-cost and low-power Relaxed Eddy Accumulation (REA) systems for long-term flux measurements of a subset of BVOC at a larger number of sites. This presentation will describe the GLOBOENET tools and strategies and present some recent results. The development and application of a third generation REA system will be described along with new approaches for quantifying canopy-scale fluxes of BVOC, such as sesquiterpenes, that are difficult to measure. Results from temperate and tropical sites will be presented and a strategy for extending these observations and using them to evaluate and improve biogenic VOC emission models will be discussed.

Guenther, A. B.; Duhl, T.; Karl, T.; Kim, S.; Shertz, S.; Turnipseed, A.

2010-12-01

172

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.

173

Analysis of Malodorous Sulfur Gases and Volatile Organometalloid Compounds in Landfill Gas Emissions Using Capillary Gas Chromatography with Programmed Temperature Vaporization Injection and Atomic Emission Detection  

Microsoft Academic Search

Volatile compounds containing Group V and Group VI elements in landfill gases are of concern as a source of toxic pollutants and unpleasant odors. Conventional analytical techniques for these compounds e.g. ICP-MS, ICP-AES are complicated, expensive and time consuming. The use of a simple programmed temperature vaporization injection (PTV) technique coupled to gas chromatography with atomic emission detection (GC-AED) has

Suwannee Junyapoon; Keith Bartle; Andrew Ross; Michael Cooke

2002-01-01

174

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

175

Tracing CO2 fluxes and plant volatile organic compound emissions by stable isotopes  

NASA Astrophysics Data System (ADS)

Plant metabolic processes exert a large influence on global climate and air quality through the emission of the greenhouse gas CO2 and volatile organic compounds (VOCs). Despite the enormous importance, processes controlling plant carbon allocation into primary and secondary metabolism, such as respiratory CO2 emission and VOC synthesis, remains unclear. The vegetation exerts a large isotopic imprint on the atmosphere through both, photosynthetic carbon isotope discrimination and fractionation during respiratory CO2 release (?13Cres). While the former is well understood, many processes driving carbon isotope fractionation during respiration are unknown1. There are striking differences in variations of ?13Cres between plant functional groups, which have been proposed to be related to carbon partitioning in the metabolic branching points of the respiratory pathways and secondary metabolism, which are linked via a number of interfaces including the central metabolite pyruvate2. Notably, it is a known substrate in a large array of secondary pathways leading to the biosynthesis of many volatile organic compounds (VOCs), such as volatile isoprenoids, oxygenated VOCs, aromatics, fatty acid oxidation products, which can be emitted by plants. Here we investigate if carbon isotope fractionation in light and dark respired CO2 is associated with VOC emissions in the atmosphere. Specifically, we hypothesize that a high carbon flux through the pyruvate into various VOC synthesis pathways is associated with a pronounced 13C-enrichment of respired CO2 above the putative substrate, as it involves the decarboxylation of the 13C-enriched C-1 from pyruvate. Based on simultaneous real-time measurements of stable carbon isotope composition of branch respired CO2 (CRDS) and VOC fluxes (PTR-MS) we traced carbon flow into these pathways by pyruvate positional labeling. We demonstrated that in a Mediterranean shrub the 13C-enriched C-1 from pyruvate is released in substantial amounts as CO2 in the light. Simultaneously, naturally 13C depleted C-2 and C-3 carbon atoms of the acetyl-moiety are emitted as a variety of VOCs. Moreover, during light-dark transitions leaf emission bursts of the oxygenated metabolite acetaldehyde were observed as part of the PDH bypass pathway in the cytosol2. This may be a new piece of evidence for the origin of 13C-enriched ?13CO2 which is released during Light-Enhanced Dark Respiration (LEDR). Our study provides the first evidence that the isotopic signature of respired CO2 is closely linked to carbon partitioning between anabolic and catabolic pathways and plants strategies of carbon investment into secondary compound synthesis. Werner C. & Gessler A. (2011) Diel variations in the carbon isotope composition of respired CO2 and associated carbon sources: a review of dynamics and mechanisms. Biogeosciences 8, 2437-2459 Jardine K, Wegener F, Abrell L, vonHaren J, Werner C (2014) Phytogenic biosynthesis and emission of methyl acetate. PCE 37, 414-424.

Werner, Christiane; Wegener, Frederik; Jardine, Kolby

2014-05-01

176

Emissions of volatile organic compounds from building materials and consumer products  

NASA Astrophysics Data System (ADS)

EPA's TEAM Study of personal exposure to volatile organic compounds (VOC) in air and drinking water of 650 residents of seven U.S. cities resulted in the identification of a number of possible sources encountered in peoples' normal daily activities and in their homes. A follow-up EPA study of publicaccess buildings implicated other potential sources of exposure. To learn more about these potential sources, 15 building materials and common consumer products were analyzed using a headspace technique to detect organic emissions and to compare relative amounts. About 10-100 organic compounds were detected offgassing from each material. Four mixtures of materials were then chosen for detailed study: paint on sheetrock; carpet and carpet glue; wallpaper and adhesives; cleansers and a spray pesticide. The materials were applied as normally used, allowed to age 1 week (except for the cleansers and pesticides, which were used normally during the monitoring period), and placed in an environmentally controlled chamber. Organic vapors were collected on Tenax-GC over a 4-h period and analyzed by GC-MS techniques. Emission rates and chamber concentrations were calculated for 17 target chemicals chosen for their toxic, carcinogenic or mutagenic properties. Thirteen of the 17 chemicals were emitted by one or more of the materials. Elevated concentrations of chloroform, carbon tetrachloride, 1,1,1-trichloroethane, n-decane, n-undecane, p-dichlorobenzene, 1,2-dichloroethane and styrene were produced by the four mixtures of materials tested. For some chemicals, these amounts were sufficient to account for a significant fraction of the elevated concentrations observed in previous indoor air studies. We conclude that common materials found in nearly every home and place of business may cause elevated exposures to toxic chemicals.

Wallace, Lance A.; Pellizzari, Edo; Leaderer, Brian; Zelon, Harvey; Sheldon, Linda

177

Estimating the impact of natural and anthropogenic emissions on cloud chemistry: the influence of organic compounds  

NASA Astrophysics Data System (ADS)

In order to estimate the anthropogenic influence of gas and aerosol emissions from the Petroleum Industry in maritime zones with clouds of small vertical extent, a numerical 1D Eulerian cloud-chemical model with detailed microphysics (Alfonso and Raga, 2002) is used to simulate the influence of water soluble organic compounds (WSOC) and organic+inorganic gas emissions on cloud development. Following Mircea et al. (2002), we tested the sensitivity of the cloud and precipitation development in the classical inorganic case (CIC) and the inorganic+organic case (IOC) with respect to CCN compositions. The results indicate an increase in the droplet concentration for the IOC, and a delay in the development of precipitation. The pH spectral evolution was studied during both the development and precipitation stages. The influence of the diffusion of formic acid and its generation by oxidation of hydrated formaldehyde in the aqueous phase result in a reduction in the pH of precipitation in the range between 0.05 and 0.15 pH units (from 1 to 3%) for the high ambient SO2 concentration (20 ppb) and between 0.2-0.5 pH units (from 4 to 10%) for the low ambient SO2 concentration (1 ppb) case.

Alfonso, L.; Raga, G. B.

2004-01-01

178

Temporal variation of volatile organic compounds and their major emission sources in Seoul, Korea.  

PubMed

This study examines the characteristics of volatile organic compounds (VOCs) and their major emission sources at the Bulgwang site in Seoul, Korea. The annual levels of VOCs (96.2-121.1 ppb C) have shown a decreasing trend from 2004 to 2008. The most abundant component in Seoul was toluene, which accounted for over 23.5 % of the total VOCs on the parts per billion on a carbon basis, and the portions of alkanes with two to six carbons constituted the largest major lumped group, ranging from 40.1 to 48.4 % (45.3 ± 3.7 %) of the total VOCs. Major components of the solvent (toluene, m/p-xylene, o-xylene, and ethylbenzene) showed high in daytime and summer and low in nighttime and winter due mainly to the variation of the ambient temperature. The species mostly emitted from gasoline vapor (i/n-butane, i/n-pentane, n-hexane, and 2-methylpentane) and vehicular exhaust (ethylene, acetylene, and benzene) showed bimodal peaks in the diurnal variation around the commuting hours because of the high traffic volume. For the 14 out of 15 highest concentration species, the weekend effect was only evident on Sundays because of the stepwise implementation of the 5-day work-week system. Principal components analysis (PCA) was applied in order to identify the sources of the 15 highest concentration VOCs and, as a result, three principal components such as gasoline vapor (48.9 %), vehicular exhaust (17.9 %), and evaporation of solvents (9.8 %) were obtained to explain a total of 76.6 % of the data variance. Most influential contributing sources at the sampling site were traffic-related ones although the use of solvent was the dominant emission source based on the official emission inventory. PMID:23728967

Shin, H J; Roh, S A; Kim, J C; Lee, S J; Kim, Y P

2013-12-01

179

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

2010-07-01

180

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

181

Detection of organic compound signatures in infra-red, limb emission spectra observed by the MIPAS-B2 instrument  

Microsoft Academic Search

Organic compounds play a central role in troposphere chemistry and increasingly are a viable target for remote sensing observations. In this paper, infra-red spectral features of three organic compounds are investigated in thermal emission spectra recorded by a balloon-borne instrument, MIPAS-B2, operating at high spectral resolution. It is demonstrated, for the first time, that PAN and acetone can be detected

J. J. Remedios; G. Allen; A. M. Waterfall; H. Oelhaf; A. Kleinert

2006-01-01

182

Emissions from sludge incinerators with venturi and tray scrubbers and wet electrostatic precipitators: Metals, chromium and nickel compounds, and organics  

SciTech Connect

A comprehensive test program was developed to determine the ratios of hexavalent to total chromium and nickel subsulfide to total nickel for a typical municipal wastewater sludge incinerator under normal combustion conditions and improved combustion conditions. Emissions of metals, hexavalent chromium, nickel subsulfide, polychlorinated dibenzodioxins and furans (PCDD/PCDFs), semi-volatile and volatile organic compounds, carbon monoxide (CO), and total hydrocarbons (THCs) from two multiple hearth incinerators and a fluidized bed incinerator were measured. The emissions were controlled at each unit with venturi scrubbers and, on two of the units, emissions from wet electrostatic precipitators (ESPs) were determined. Flue gas sampling was conducted at the inlet and outlet of the air pollution control devices at three separate sites. Gas concentrations, mass emission rates, metals-to-particulate ratios, and emissions factors were reported. Analytical results for the process samples were reported.

Bostian, H.E.; DeWees, W.G.; Crumpler, E.P.; Lewis, F.M.

1993-01-01

183

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

184

AN IMPROVED MODEL FOR ESTIMATING EMISSIONS OF VOLATILE ORGANIC COMPOUNDS FROM FORESTS IN THE EASTERN UNITED STATES (Journal)  

EPA Science Inventory

Regional estimates of biogenic volatile organic compound (BVOC) emissions are important inputs for models of atmospheric chemistry and carbon budgets. Since forests are the primary emitters of BVOCs, it is important to develop reliable estimates of their areal coverage and BVOC e...

185

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...

186

Biogenic volatile organic compound emissions (BVOCs) I. Identifications from three continental sites in the U.S  

Microsoft Academic Search

Vegetation composition and biomass were surveyed for three specific sites in Atlanta, GA; near Rhinelander, WI; and near Hayden, CO. At each research site emissions of biogenic volatile organic compounds (BVOCs) from the dominant vegetation species were sampled by enclosing branches in bag enclosure systems and sampling the equilibrium head space onto multi-stage solid adsorbent cartridges. Analysis was performed using

Detlev Helmig; Lee F. Klinger; Alex Guenther; Lee Vierling; Chris Geron; Patrick Zimmerman

1999-01-01

187

An Evaluation of Hazardous Air Pollutants and Volatile Organic Compound Emissions from Tank Barges in Memphis, TN  

EPA Science Inventory

Many urban centers have population centers near river ports, which may be affected by volatile organic compound (VOC) and hazardous air pollutant (HAP) emissions from tank barge traffic. This study will examine Memphis, Tennessee and West Memphis, Arkansas. Both cities (located ...

188

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

189

Emission and excitation characteristics and internal quantum efficiencies of vacuum-ultraviolet excited Pr3+ -doped fluoride compounds  

NASA Astrophysics Data System (ADS)

We report on the spectroscopic investigation of Pr3+ -doped binary, ternary, and quaternary fluoride compounds exhibiting photon cascade emission. Under vacuum-ultraviolet synchrotron excitation at wavelengths below 200 nm in the 4f5d bands of the Pr3+ ion the emission spectra show intraconfigurational 4f-4f transitions originating from the S01 and P03 multiplets. In the ternary and quaternary compounds investigated, i.e., Ca-, Sr-, Ba-, and Rb-fluorides, broadband emission due to transitions from the 4f5d level of Pr3+ are also observed. The different types of emission transitions observed in the compounds investigated were analyzed in detail. The internal quantum efficiency for the visible spectral range (390 nm-750 nm), ?vis , is determined with the help of the Judd-Ofelt theory and the branching ratios of the S01 emission transitions. The dependence of this quantum efficiency ?vis from the ionic radius of the second cation (R2nd) , the effective ligand distance, and the coordination number is investigated.

Kück, Stefan; Sokólska, Irena; Henke, Markus; Scheffler, Thomas; Osiac, Eugen

2005-04-01

190

Volatile Organic Compound (VOC) Emissions from Dairy Cows and Their Waste  

NASA Astrophysics Data System (ADS)

Biogenic VOCs are typically defined as those directly emitted from plants, but approximately 6% of global net primary production is consumed by cattle that carry out enteric fermentation and then emit VOCs that could also be considered biogenic. Current regulatory estimates suggest that dairy cattle in central California emit VOCs at rates comparable to those from passenger vehicles in the region, and thus contribute significantly to the extreme non-attainment of ozone standards there. We report PTR-MS measurements of ammonia and VOCs, and cavity-enhanced-absorption gas analyzer (Los Gatos Research, Inc.) measurements of CH4, emitted from dairy cattle in various stages of pregnancy/lactation and their waste. Experiments were conducted in chambers at UC Davis that simulate freestall cow housing conditions. CH4 fluxes ranged from 125-374 lb/cow/year. The compounds with the highest fluxes from '3 cows+waste' treatments were: ammonia (1-18), methanol (0-2.3), acetone+propanal (0.2-0.7), dimethylsulfide (0-0.4), and mass 109 (likely ID = p-cresol; 0-0.3) in lb/cow/year. Mass 60 (likely ID = trimethylamine) and acetic acid were also abundant. There were 10s of additional compounds with detectable, but small, emissions. A few compounds that were likely emitted (i.e. ethanol, formaldehyde, and dimethylamine) were not quantified by the PTR-MS. The total flux for all measured organic gases (TOG = CH4 + PTR-MS VOCs(including acetone+propanal)) averaged 246±45 lb/cow/year for '3 cows+waste' treatments, and was dominated by methane (>98%). TOG flux for 'waste only' treatments averaged 1.1±0.1 lb/cow/year, and was instead dominated by VOC (>84%). The PTR-MS VOCs as a percent of TOG (0.6±0.2%) emitted from '3 cows+waste' treatments in chamber conditions was a factor of 10 smaller than that currently estimated by the California Air Resources Board. In addition, the ozone forming potentials of the most abundant VOCs are only about 10% those of typical combustion or plant-derived VOCs, implying dairy cattle have a smaller effect on ozone formation than currently assumed by air districts in central California.

Shaw, S.; Holzinger, R.; Mitloehner, F.; Goldstein, A.

2005-12-01

191

A temporally and spatially resolved 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 aerosol (SOA) abatement measures. We made VOC measurements at 27 sites and online observations at an urban site in Beijing from July 2009 to January 2012. Based on these measurement data, we determined the spatial and temporal distribution of VOCs, estimated their annual emission strengths based on their emission ratios relative to carbon monoxide (CO), and quantified the relative contributions of various sources using the chemical mass balance (CMB) model. These results from ambient measurements were compared with existing emission inventories to evaluate the spatial distribution, species-specific emissions, and source structure of VOCs in Beijing. 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 may be underestimated, while the emissions of styrene and 1,3-butadiene may be overestimated by current inventories. Source apportionment using the CMB model identified vehicular exhaust as the most important VOC source, with the relative contribution of 49%, in good agreement with the 40-51% estimated by emission inventories. The relative contribution of paint and solvent utilization obtained from the CMB model was 14%, significantly lower than the value of 32% reported by one existing inventory. Meanwhile, the relative contribution of liquefied petroleum gas (LPG) usage calculated using the CMB model was 6%, whereas LPG usage contribution was not reported by current emission inventories. These results suggested that VOC emission strengths in southern suburban area of Beijing, annual emissions of C2-C4 alkanes, OVOCs and some alkenes, and the contributions of solvent and paint utilization and LPG usage in current inventories all require significant revisions.

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

2014-06-01

192

Infant exposure to emissions of volatile organic compounds from crib mattresses.  

PubMed

Infants spend most of their time sleeping and are likely to be exposed to elevated concentrations of chemicals released from their crib mattresses. Small-scale chamber experiments were conducted to determine the area-specific emission rates (SERs) of volatile organic compounds (VOCs) in a collection of twenty new and used crib mattresses. All mattress samples were found to emit VOCs and the mean values of total VOC (TVOC) SERs were 56 ?g/m(2)h at 23 °C and 139 ?g/m(2)h at 36 °C. TVOC SERs were greater for new mattresses compared to used ones and were influenced by the type of foam material and the presence of mattress cover layer. A variety of VOCs were identified, with polyurethane foam releasing a greater diversity of VOCs compared to polyester foam. Large-scale chamber experiments were conducted with an infant thermal manikin. TVOC concentrations sampled in the breathing zone and interior pore air of the crib mattress foam were found to be greater than the bulk room air by factors in the range of 1.8 to 2.4 and 7.5 to 21, respectively. The results suggest that crib mattresses are an important source of VOCs and infant exposure to VOCs are possibly elevated in their sleep microenvironments. PMID:24548111

Boor, Brandon E; Järnström, Helena; Novoselac, Atila; Xu, Ying

2014-03-18

193

Re-Evaluation of Clinical Dementia Diagnoses with Pittsburgh Compound B Positron Emission Tomography  

PubMed Central

Objectives There is an overlap regarding Pittsburgh compound B (PIB) retention in patients clinically diagnosed as Alzheimer's disease (AD) and non-AD dementia. The aim of the present study was to investigate whether there are any differences between PIB-positive and PIB-negative patients in a mixed cohort of patients with neurodegenerative dementia of mild severity regarding neuropsychological test performance and regional cerebral glucose metabolism measured with [18F]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET). Methods Eighteen patients clinically diagnosed as probable AD or frontotemporal dementia were examined with PIB PET, FDG PET and neuropsychological tests and followed for 5-9 years in a clinical setting. Results The PIB-positive patients (7 out of 18) had slower psychomotor speed and more impaired visual episodic memory than the PIB-negative patients; otherwise performance did not differ between the groups. The initial clinical diagnoses were changed in one third of the patients (6 out of 18) during follow-up. Conclusions The subtle differences in neuropsychological performance, the overlap of hypometabolic patterns and clinical features between AD and non-AD dementia highlight the need for amyloid biomarkers and a readiness to re-evaluate the initial diagnosis.

Degerman Gunnarsson, M.; Lindau, M.; Santillo, A.F.; Wall, A.; Engler, H.; Lannfelt, L.; Basun, H.; Kilander, L.

2013-01-01

194

[Emission characteristics and safety evaluation of volatile organic compounds in manufacturing processes of automotive coatings].  

PubMed

Emission characteristics of volatile organic compounds (VOCs) were investigated in an automotive coating manufacturing enterprise. Air samples were taken from eight different manufacturing areas in three workshops, and the species of VOCs and their concentrations were measured by gas chromatography-mass spectrometry (GC-MS). Safety evaluation was also conducted by comparing the concentration of VOCs with the permissible concentration-short term exposure limit (PC-STEL) regulated by the Ministry of Health. The results showed that fifteen VOCs were detected in the indoor air of the automotive coatings workshop, including benzene, toluene, ethylbenzene, xylene, ethyl acetate, butyl acetate, methyl isobutyl ketone, propylene glycol monomethyl ether acetate, trimethylbenzene and ethylene glycol monobutyl ether, Their concentrations widely ranged from 0.51 to 593.14 mg x m(-3). The concentrations of TVOCs were significantly different among different manufacturing processes. Even in the same manufacturing process, the concentrations of each component measured at different times were also greatly different. The predominant VOCs of indoor air in the workshop were identified to be ethylbenzene and butyl acetate. The concentrations of most VOCs exceeded the occupational exposure limits, so the corresponding control measures should be taken to protect the health of the workers. PMID:24640895

Zeng, Pei-Yuan; Li, Jian-Jun; Liao, Dong-Qi; Tu, Xiang; Xu, Mei-Ying; Sun, Guo-Ping

2013-12-01

195

Salt Lakes of Western Australia - Emissions of natural volatile organic compounds  

NASA Astrophysics Data System (ADS)

Western Australia is a semi-/arid region that is heavily influenced by global climate change and agricultural land use. The area is known for its many saline lakes with a wide range of hydrogeochemical parameters. This area has been repeatedly investigated since 2006 and consists of ephemeral saline and saline groundwater sourced lakes with a pH reaching from 2.5 to 7.1. The semi-/arid region was originally covered by natural eucalyptus forests, but land-use has changed considerably after large scale deforestation from 1950 to 1970. Today the region is mostly used for growing wheat and live stock. The deforestation led to a rising groundwater table, bringing dissolved salts and minerals to the surface. In the last decades, a concurrent alteration of rain periods has been observed. A reason could be the regional formation of ultra-fine particles that were measured with car-based and airborne instruments around the salt lakes in several campaigns between 2006 and 2011. These ultra-fine particles emitted from the lakes and acting as cloud condensation nuclei can modify cloud microphysics and thus suppress rain events [1]. New data from a campaign in 2012 accentuates the importance of these hyper saline environments for the local climate. Ground-based particle measurements around the salt lakes in 2012 were accompanied by novel chamber experiments directly on the lakes. The 1.5 m³ cubic chamber was constructed from transparent PTFE foil permitting photochemistry within while preventing dilution of the air due to lateral wind transport. This experimental setup allows linking the measured data directly to the chemistry of and above the salt lakes. Another advantage of the PTFE chamber is the enrichment of volatile organic compounds (VOC) that are emitted from salt lakes as possible precursors for the ultra-fine particles. Chamber air was sampled using stainless steel canisters. Sediment, crust and water samples were taken for investigation of potential VOC emissions in the laboratory using GC-MS technique. Different VOC and halogenated volatile compounds (VOX), exceeding atmospheric background concentrations, where identified from the sampled chamber air. Their enrichment or depletion over the time in the chamber allows for postulated reaction pathways leading to the formation of ultra-fine particles. Soil and water samples showed a variety of highly volatile and semi-volatile VOC/VOX. An abiotic formation of these VOC/VOX seems conclusive due to iron-catalysed reactions below the salt crust [2]. The salt crust is the link through which VOC/VOX pass from the soil/groundwater to the atmosphere. During desiccation salt crystals grow, trapping gases as fluid inclusions (FI). The study of FI provides qualitative emission data of VOC/VOX during desiccation which can be released upon wetting to the atmosphere. This study includes the emission of VOC/VOX from hyper saline terrestrial environments and their role in the atmospheric formation of climate relevant ultra-fine particles. [1] Junkermann et al., 2009, Atmos.Chem.Phys., 9, 6531-6539 [2] Huber et al., 2009, Environ.Sci.Technol., 43 (13), 4934-4939

Sattler, Tobias; Krause, Torsten; Schöler, Heinfried; Kamilli, Katharina; Held, Andreas; Zetzsch, Cornelius; Ofner, Johannes; Junkermann, Wolfgang; Atlas, Elliot

2013-04-01

196

Compound  

NASA Astrophysics Data System (ADS)

We have prepared Ce-doped polycrystalline AgSbTe2.01 compounds from high-purity elements by a melt-quench technique followed by spark plasma sintering, and their thermoelectric transport properties have been investigated in the temperature range of 300 K to 625 K. The actual concentration of Ce was much less than the initial composition, but roughly proportional to it. Small additions of Ce shifted the composition of the homogeneity range from the nearly ideal atomic ratio Ag:Sb:Te = 0.98:1.02:2.01 toward Sb rich (Ag poor), and led to the reemergence of Ag2Te impurity in AgSbTe2 compound. The Ce-doped samples possessed lower electrical conductivity compared with the undoped AgSbTe2.01 compound at room temperature, but the carrier mobility and effective mass were essentially constant, indicating intact band structure near the covalent band maximum upon Ce substitution for Sb. Due to the decrease of lattice vibration anharmonicity resulting from Ce substitution for Sb, the lattice conductivity of the Ce-doped samples was about 0.1 W m-1 K-1 higher than that of the AgSbTe2.01 sample, and the magnitude spanned the range from 0.30 W m-1 K-1 to 0.55 W m-1 K-1. A ZT of 1.20 was achieved at about 615 K for the AgSb0.99Ce0.01Te2.01 sample.

Du, B.; Li, H.; Tang, X.

2014-06-01

197

Biogenic volatile organic compound (BVOC) emissions from forested areas in Turkey: Determination of specific emission rates for thirty-one tree species.  

PubMed

Normalized biogenic volatile organic compound (BVOC) emission rates for thirty one tree species that cover the 98% of national forested areas in Turkey were determined. Field samplings were performed at fourteen different forested areas in Turkey using a specific dynamic enclosure system. The selected branches of tree species were enclosed in a chamber consisted of a transparent Nalofan bag. The air-flows were sampled from both inlet and outlet of the chamber by Tenax-filled sorbent tubes during photosynthesis of trees under the presence of sunlight. Several environmental parameters (temperature, humidity, photosynthetically active radiation-PAR, and CO2) were continuously monitored inside and outside the enclosure chamber during the samplings. Collected samples were analyzed using a gas chromatography mass spectrometry (GC/MS) system equipped with a thermal desorber (TD). Sixty five BVOCs classified in five major groups (isoprene, monoterpenes, sesquiterpenes, oxygenated sesquiterpenes, and other oxygenated compounds) were analyzed. Emission rates were determined by normalization to standard conditions (1000?mol/m(2)s PAR and 30°C temperature for isoprene and 30°C temperature for the remaining compounds). In agreement with the literature, isoprene was mostly emitted by broad-leaved trees while coniferous species mainly emitted monoterpenes. Several tree species such as Sweet Chestnut, Silver Lime, and European Alder had higher monoterpene emissions although they are broad-leaved species. High isoprene emissions were also observed for a few coniferous species such as Nordmann Fir and Oriental Spruce. The highest normalized total BVOC emission rate of 27.1?g/gh was observed for Oriental Plane while South European Flowering Ash was the weakest BVOC emitter with a total normalized emission rate of 0.031?g/gh. Monoterpene emissions of broad-leaved species mainly consisted of sabinene, limonene and trans-beta-ocimene, while alpha-pinene, beta-pinene and beta-myrcene were generally emitted by coniferous species. Oxygenated compounds were the third most prominent BVOC group and sesquiterpenes had slightly lower contributions. PMID:24858222

Aydin, Yagmur Meltem; Yaman, Baris; Koca, Husnu; Dasdemir, Okan; Kara, Melik; Altiok, Hasan; Dumanoglu, Yetkin; Bayram, Abdurrahman; Tolunay, Doganay; Odabasi, Mustafa; Elbir, Tolga

2014-08-15

198

Compound  

NASA Astrophysics Data System (ADS)

Recently, Cu-based chalcogenides such as Cu3SbSe4, Cu2Se, and Cu2SnSe3 have attracted much attention because of their high thermoelectric performance and their common feature of very low thermal conductivity. However, for practical use, materials without toxic elements such as selenium are preferable. In this paper, we report Se-free Cu3SbS4 thermoelectric material and improvement of its figure of merit ( ZT) by chemical substitutions. Substitutions of 3 at.% Ag for Cu and 2 at.% Ge for Sb lead to significant reductions in the thermal conductivity by 37% and 22%, respectively. These substitutions do not sacrifice the power factor, thus resulting in enhancement of the ZT value. The sensitivity of the thermal conductivity to chemical substitutions in these compounds is discussed in terms of the calculated phonon dispersion and previously proposed models for Cu-based chalcogenides. To improve the power factor, we optimize the hole carrier concentration by substitution of Ge for Sb, achieving a power factor of 16 ?W/cm K2 at 573 K, which is better than the best reported for Se-based Cu3SbSe4 compounds.

Suzumura, Akitoshi; Watanabe, Masaki; Nagasako, Naoyuki; Asahi, Ryoji

2014-06-01

199

Global fire emission estimates (2007-2012) derived from inversion of formaldehyde columns  

NASA Astrophysics Data System (ADS)

Wildfires have a strong impact on the chemistry and composition of the atmosphere and the radiative forcing. The fire emission estimates bear, however, important uncertainties due to the limited amount of field measurements, uncertainties in satellite burned area products, as well as empirical relations used for fuel type allocations. Atmospheric inversions are an alternative approach that provides new independent constraints on the fire estimates. This method involves measurements of trace gases combined with atmospheric models, where optimization algorithms are used to minimize the discrepancy between the model and the observations by adjusting the emission estimates. In this communication, we present global emission estimates of non-methane volatile organic compounds (NMVOCs), inferred from inversion of formaldehyde (HCHO) columns retrieved from the Global Ozone Monitoring Experiment-2 (GOME-2) instrument (De Smedt et al., 2012). The IMAGESv2 global CTM provides the relationship between the emissions and the vertical columns. The Global Fire Emissions Database version 3 (GFEDv3, van der Werf et al., 2010) is used as a priori bottom-up inventory in the model. The agreement between formaldehyde columns calculated by the IMAGESv2 model and the formaldehyde columns from GOME-2 is optimized using the adjoint modelling technique (Stavrakou et al., 2009). The obtained top-down fire emission estimates between 2007 and 2012 are available at the GlobEmission data portal (http://www.globemission.eu) on a monthly basis and at 0.5°x0.5° spatial resolution. The emission estimates are evaluated against three independent emission inventories: GFEDv3 (van der Werf et al., 2010), GFAS (Kaiser et al., 2012) and FINN (Wiedinmyer et al., 2011). Furthermore, simulated CO columns over the fire-affected regions will be compared with CO columns retrieved from the IASI sensor (George et al., 2009).

Bauwens, Maite; Stavrakou, Trissevgeni; Müller, Jean-Francois; De Smedt, Isabelle; Van Roozendael, Michel

2014-05-01

200

Mutagenicity of Polycyclic Aromatic Compounds (PAC), Identified in Source Emissions and Ambient Air.  

National Technical Information Service (NTIS)

Several polycyclic aromatic compounds including nitrated and oxygenated derivatives of polycyclic aromatic hydrocarbons were tested for mutagenic activity in the Salmonella/ microsome assay. Among the compounds tested the isomer mix of nitro-1-hydroxypyre...

M. Moeller I. Hagen T. Randahl

1985-01-01

201

Scaling law of angular emission distributions of laser ablated particle pulses from monoatomic and compound targets  

Microsoft Academic Search

In the present experiment we have investigated angular emission distributions of freely expanding laser produced plasma pulses quantitatively and over a wide mass range (27–184) both for monoatomic and binary species. The following major results have been obtained: (1) All emission shapes can be closely fitted by Gauß-functions. (2) The emission cones of all species steepen continuously as a function

S. N. Srivastava; K. Rohr

2005-01-01

202

Do volatile organic compound emissions of Tunisian cork oak populations originating from contrasting climatic conditions differ in their responses to summer drought?  

Microsoft Academic Search

The intrinsic variability of volatile organic compound emissions and photosynthetic parameters in response to two drying cycles was investigated on Quercus suber L. saplings originating from three Tunisian populations native to contrasting climates. Emissions mainly included monoterpenes plus traces of sesquiterpenes and methylsalicylate that steadily decreased during the experiment unrelated to treatments. Instead, monoterpene emissions increased by 30% during a

Michael Staudt; Amel Ennajah; Florent Mouillot; Richard Joffre

2008-01-01

203

A comprehensive emission inventory of biogenic volatile organic compounds in Europe: improved seasonality and land-cover  

NASA Astrophysics Data System (ADS)

Biogenic volatile organic compounds (BVOC) emitted from vegetation are important for the formation of secondary pollutants such as ozone and secondary organic aerosols (SOA) in the atmosphere. Therefore, BVOC emission are an important input for air quality models. To model these emissions with high spatial resolution, the accuracy of the underlying vegetation inventory is crucial. We present a BVOC emission model that accommodates different vegetation inventories and uses satellite-based measurements of greenness instead of pre-defined vegetation periods. This approach to seasonality implicitly treats effects caused by water or nutrient availability, altitude and latitude on a plant stand. Additionally, we test the influence of proposed seasonal variability in enzyme activity on BVOC emissions. In its present setup, the emission model calculates hourly emissions of isoprene, monoterpenes, sesquiterpenes and the oxygenated volatile organic compounds (OVOC) methanol, formaldehyde, formic acid, ethanol, acetaldehyde, acetone and acetic acid. In this study, emissions based on three different vegetation inventories are compared with each other and diurnal and seasonal variations in Europe are investigated for the year 2006. Two of these vegetation inventories require information on tree-cover as an input. We compare three different land-cover inventories (USGS GLCC, GLC2000 and Globcover 2.2) with respect to tree-cover. The often-used USGS GLCC land-cover inventory leads to a severe reduction of BVOC emissions due to a potential miss-attribution of broad-leaved trees and reduced tree-cover compared to the two other land-cover inventories. To account for uncertainties in the land-cover classification, we introduce land-cover correction factors for each relevant land-use category to adjust the tree-cover. The results are very sensitive to these factors within the plausible range. For June 2006, total monthly BVOC emissions decreased up to -27% with minimal and increased up to +71% with maximal factors, while in January 2006, the changes in monthly BVOC emissions were -54 and +56% with minimal and maximal factors, respectively. The new seasonality approach leads to a reduction in the annual emissions compared with non-adjusted data. The strongest reduction occurs in OVOC (up to -32%), the weakest in isoprene (as little as -19%). If also enzyme seasonality is taken into account, however, isoprene reacts with the steepest decrease of annual emissions, which are reduced by -44% to -49%, annual emissions of monoterpenes reduce between -30 and -35%. The sensitivity of the model to changes in temperature depends on the climatic zone but not on the vegetation inventory. The sensitivity is higher for temperature increases of 3 K (+31% to +64%) than decreases by the same amount (-20 to -35%). The climatic zones "Cold except summer" and "arid" are most sensitive to temperature changes in January for isoprene and monoterpenes, respectively, while in June, "polar" is most sensitive to temperature for both isoprene and monoterpenes. Our model predicts the oxygenated volatile organic compounds to be the most abundant fraction of the annual European emissions (3571-5328 Gg yr-1), followed by monoterpenes (2964-4124 Gg yr-1), isoprene (1450-2650 Gg yr-1) and sesquiterpenes (150-257 Gg yr-1). We find regions with high isoprene emissions (most notably the Iberian Peninsula), but overall, oxygenated VOC dominate with 43-45% (depending on the vegetation inventory) contribution to the total annual BVOC emissions in Europe. Isoprene contributes between 18-21%, monoterpenes 33-36% and sesquiterpenes contribute 1-2%. We compare the concentrations of biogenic species simulated by an air quality model with measurements of isoprene and monoterpenes in Hohenpeissenberg (Germany) for both summer and winter. The agreement between observed and modelled concentrations is better in summer than in winter. This can partly be explained with the difficulty to model weather conditions in winter accurately, but also with the increased an

Oderbolz, D. C.; Aksoyoglu, S.; Keller, J.; Barmpadimos, I.; Steinbrecher, R.; Skjøth, C. A.; Plaß-Dülmer, C.; Prévôt, A. S. H.

2013-02-01

204

A novel approach to emission modelling of biogenic volatile organic compounds in Europe: improved seasonality and land-cover  

NASA Astrophysics Data System (ADS)

Biogenic volatile organic compounds (BVOC) emitted from vegetation are important for the formation of secondary pollutants such as ozone and secondary organic aerosols (SOA) in the atmosphere. Therefore, BVOC emission are an important input for air quality models. To model these emissions with high spatial resolution, the accuracy of the underlying vegetation inventory is crucial. We present a BVOC emission model that accommodates different vegetation inventories and uses satellite-based measurements of greenness instead of pre-defined vegetation periods. This approach to seasonality implicitly treats effects caused by water or nutrient availability, altitude and latitude on a plant stand. Additionally, we test the influence of proposed seasonal variability in enzyme activity on BVOC emissions. In its present setup, the emission model calculates hourly emissions of isoprene, monoterpenes, sesquiterpenes and the oxygenated volatile organic compounds (OVOC) methanol, formaldehyde, formic acid, ethanol, acetaldehyde, acetone and acetic acid. In this study, emissions based on three different vegetation inventories are compared with each other and diurnal and seasonal variations in Europe are investigated for the year 2006. Two of these vegetation inventories require information on tree-cover as an input. We compare three different land-cover inventories (USGS GLCC, GLC2000 and Globcover 2.2) with respect to tree-cover. The often-used USGS GLCC land-cover inventory leads to a severe reduction of BVOC emissions due to a potential miss-attribution of broad-leaved trees and reduced tree-cover compared to the two other land-cover inventories. To account for uncertainties in the land-cover classification, we introduce land-cover correction factors for each relevant land-use category to adjust the tree-cover. The results are very sensitive to these factors within the plausible range. For June 2006, total monthly BVOC emissions decreased up to -27% with minimal and increased up to +71% with maximal factors, while in January 2006, the changes in monthly BVOC emissions were -54 and +56% with minimal and maximal factors, respectively. The new seasonality approach leads to a reduction in the annual emissions compared with non-adjusted data. The strongest reduction occurs in OVOC (up to -32%), the weakest in isoprene (as little as -19%). If also enzyme seasonality is taken into account, however, isoprene reacts with the steepest decrease of annual emissions, which are reduced by -44% to -49%, annual emissions of monoterpenes reduce between -30 and -35%. The sensitivity of the model to changes in temperature depends on the climatic zone but not on the vegetation inventory. The sensitivity is higher for temperature increases of 3 K (+31% to +64%) than decreases by the same amount (-20 to -35%). The climatic zones "Cold except summer" and "arid" are most sensitive to temperature changes in January for isoprene and monoterpenes, respectively, while in June, "polar" is most sensitive to temperature for both isoprene and monoterpenes. Our model predicts the oxygenated volatile organic compounds to be the most abundant fraction of the annual European emissions (3571-5328 Gg yr-1), followed by monoterpenes (2964-4124 Gg yr-1), isoprene (1450-2650 Gg yr-1) and sesquiterpenes (150-257 Gg yr-1). We find regions with high isoprene emissions (most notably the Iberian Peninsula), but overall, oxygenated VOC dominate with 43-45% (depending on the vegetation inventory) contribution to the total annual BVOC emissions in Europe. Isoprene contributes between 18-21%, monoterpenes 33-36% and sesquiterpenes contribute 1-2%. We compare the concentrations of biogenic species simulated by an air quality model with measurements of isoprene and monoterpenes in Hohenpeissenberg (Germany) for both summer and winter. The agreement between observed and modelled concentrations is better in summer than in winter. This can partly be explained with the difficulty to model weather conditions in winter accurately, but also with the increased an

Oderbolz, D. C.; Aksoyoglu, S.; Keller, J.; Barmpadimos, I.; Steinbrecher, R.; Skjøth, C. A.; Plaß-Dülmer, C.; Prévôt, A. S. H.

2012-08-01

205

Top-Down Constraints on the Emissions of Anthropogenic Volatile Organic Compounds from a Mega-City  

NASA Astrophysics Data System (ADS)

During the CalNex study in May-June of 2010, an extensive set of volatile organic compounds (VOCs) was measured in the Los Angeles basin and its in- and outflow areas. Measurements were made from the NOAA WP-3D research aircraft, the research vessel Atlantis and a ground site in Pasadena, California. In this presentation, the results are used to derive top-down constraints on the emissions of anthropogenic VOCs from this North-American megacity. The VOC data from CalNex in 2010 are put in perspective by comparing them with results from an earlier flight of the NOAA WP-3D in the Los Angeles basin in 2002, from a number of other earlier studies and from two different air quality monitoring networks. Strongly decreasing trends of ~7% per year are observed for most VOCs that are emitted from motor vehicles or photo-chemically produced from these emissions. Decreasing trends are less strong for small alkanes, which are mostly from natural gas related emissions, and oxygenated VOCs produced from them. The composition of urban VOC emissions was determined using the data obtained by gas-chromatography mass spectrometry at the ground site in Pasadena. Emission ratios of hydrocarbons versus ethyne were obtained using two methods. First, emission ratios were determined from nighttime data only. Second, the degree of photochemical processing of the sampled air masses was estimated, and emission ratios were determined by extrapolating to a zero photochemical age. Both methods agreed within the combined uncertainties for most VOCs. The composition of urban VOC emissions in Los Angeles was compared with other urban regions including in the U.S. and Europe and found to be similar. Measurements of ethanol at the ground site in Pasadena showed much higher mixing ratios than observed earlier in the northeastern U.S. The difference is attributed in part to the strongly increased use of fuel ethanol in the U.S.: in 2010, about 10% of gasoline consisted of ethanol, whereas that percentage was about 1% in the early 2000s. The relative importance of emissions and photochemical formation of oxygenated VOCs is also studied using data from the ground site in Pasadena. It is found that aldehydes, ketones and glyoxal have significant direct emissions in addition to secondary formation sources. The direct emissions are not well represented in emission inventories. Acids have no or small direct emissions but significant secondary formation that is difficult to account for using our best understanding of the gas-phase chemistry. Alcohols have direct emission sources but no or small secondary formation.

De Gouw, J. A.; Warneke, C.; Borbon, A.; Gilman, J. B.; Kuster, W. C.; Parrish, D. D.; Atlas, E. L.; Blake, D. R.

2012-12-01

206

Comparative oxidation and net emissions of methane and selected non-methane organic compounds in landfill cover soils.  

PubMed

The surface emissions of methane (CH4) and non-methane organic compounds (NMOCs) were determined at two different areas at a French landfill: a permanently covered and fully vegetated area (40 cm coarse sand + 80 cm of loam) and a temporarily covered area (40 cm of coarse sand). The 37 NMOCs quantified in the landfill gas samples included alkanes (C1-C10), alkenes (C1-C4), halogenated hydrocarbons (including (H)CFCs), and aromatic hydrocarbons. Both positive and negative CH4 fluxes ranging from -0.01 to 0.008 g m(-2) d(-1) were measured from the permanently covered cell. However, high spatial variation was observed, and a hot spot with a high flux (10 g m(-2) d(-1)) was identified. A higher CH4 emission occurred from the temporarily covered cell (CH4 flux of 49.9 g m(-2) d(-1)) as compared to the permanently covered cell. The NMOC fluxes from the permanently covered zone were all very small with both positive and negative fluxes in the order of 10(-7) to 10(-5) g m(-2) d(-1). Higher and mainly positive NMOC fluxes in the order of 10(-5) to 10(-4) g m(-2) d(-1) were obtained from the temporarily covered zone. The lower emission from the permanently covered and fully vegetated cell was attributable to the thicker soil layer, which functions as microbial habitat for methanotrophic bacteria. The NMOC oxidation capacity was investigated in soil microcosms incubated with CH4. Maximal oxidation rates for the halogenated aliphatic compounds varied between 0.06 and 8.56 microg (g of soil)(-1) d(-1). Fully substituted hydrocarbons (tetrachloromethane, perchloroethylene, CFC-11, CFC-12, and CFC-113) were not degraded in the presence of CH4 and O2. Benzene and toluene were rapidly degraded, giving very high maximal oxidation rates (28 and 39 microg (g of soil)(-1) d(-1)). On the basis of the emission measurements and the batch experiments conducted, a general pattern was observed between emissions and biodegradability of various NMOCs. The emissions mainly consisted of compounds that were not degradable or slowly degradable, while an uptake of easily degradable compounds was registered. As an example, perchloroethylene, trichloromethane, CFC-11, and CFC-12 were emitted, while atmospheric consumption of aromatic hydrocarbons and lower chlorinated hydrocarbons such as vinyl chloride, dichloromethane, and chloromethane was observed. This study demonstrates that landfill soil covers show a significant potential for CH4 oxidation and co-oxidation of NMOCs. Under certain conditions, landfills may even function as sinks for CH4 and selected NMOCs, like aromatic hydrocarbons and lower chlorinated compounds. PMID:14655701

Schuetz, Charlotte; Bogner, Jean; Chanton, Jeffrey; Blake, Donald; Morcet, Muriel; Kjeldsen, Peter

2003-11-15

207

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

208

Cleaner co-combustion of lignite–biomass–waste blends by utilising inhibiting compounds of toxic emissions  

Microsoft Academic Search

In this paper, the co-combustion behaviour of coal with wastes and biomass and the related toxic gaseous emissions were investigated. The objective of this work is to add on towards a cleaner co-combustion of lignite–waste–biomass blends by utilizing compounds that could inhibit the formation of toxic pollutants. A series of co-combustion tests was performed in a pilot scale incinerator, and

G. Skodras; A. Palladas; S. P. Kaldis; G. P. Sakellaropoulos

2007-01-01

209

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 Panga; Xiaoyan Shia; Yujing Mu; Hong He; Shijin Shuaib; Hu Chen; Rulong Lib

210

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

2012-10-01

211

[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

212

Emission of volatile organic compounds by apple trees under spider mite attack and attraction of predatory mites.  

PubMed

Emission rates of volatile organic compounds (VOCs) from Pirus malus L. subsp. mitis (Wallr.) var. Golden Delicious and var. Starking attacked by the phytophagous mite Panonychus ulmi Koch, and their attractiveness to the predatory mites Amblyseius andersoni Chant and Amblyseius californicus McGregor, were studied during three years. A large variability was found in the emission of individual VOCs depending on the infestation, the apple tree variety and the date. There were larger total VOC emission rates and larger total VOC leaf concentrations in apple trees attacked by phytophagous mites, especially in the var. Starking. In infested trees of this variety, there were also more predatory mites. An olfactometer assay showed that predatory mites preferentially chose branches infested by Panonychus ulmi (85% went to infested branches vs 15% to uninfested control branches) indicating that volatiles may be used as cues to find their prey. PMID:11508530

Llusià, J; Peñuelas, J

2001-01-01

213

An improved model for estimating emissions of volatile organic compounds from forests in the eastern United States  

SciTech Connect

Regional estimates of biogenic volatile organic compound (BVOC) emissions are important inputs for models of atmospheric chemistry and carbon budgets. Since forests are the primary emitters of BVOCs, it is important to develop reliable estimates of their areal coverage and BVOC emission rate. A new system is developed to estimate these emissions for specific tree genera at hourly and county level resolution. The U.S. Department of Agriculture, Forest Service Forest Inventory and Analysis Eastwide Database is used to describe the areal extent, species composition, and tree diameter distributions of United States forests. Horizontal canopy occupancy by genera is then estimated as a function of diameter at breast height. Growing season peak foliar masses are derived from the empirical literature for canopies of deciduous and coniferous genera. A simple canopy model is used to adjust photosynthetically active solar radiation at five vertical levels in the canopy. Leaf temperature and photosynthetically active radiation derived from ambient conditions above the forest canopy are then used to drive empirical equations to estimate genus level emission rates of BVOCs vertically through forest canopies. These genera level estimates are then aggregated to regional levels for comparison with the regulatory model currently used and for input into air quality models. The proposed model yields isoprene emission rate estimates for specific countries that are 5 to 10 times higher (and total BVOC emission rates that are 3 to 5 times higher) than the Environmental Protection Agency BVOC emission rate model currently used. Emission estimates of isoprene and monoterpenes from the new system compare favorably with rates measured at various forested sites in the United States.

Geron, C.D.; Guenther, A.B.; Pierce, T.E. [Air and Energy Research Laboratory, NC (United States)]|[National Center for Atmospheric Research, Boulder, CO (United States)]|[NOAA, NC (United States)

1994-06-01

214

Emissions of volatile organic compounds and leaf structural characteristics of European aspen (Populus tremula) grown under elevated ozone and temperature.  

PubMed

Northern forest trees are challenged to adapt to changing climate, including global warming and increasing tropospheric ozone (O(3)) concentrations. Both elevated O(3) and temperature can cause significant changes in volatile organic compound (VOC) emissions as well as in leaf anatomy that can be related to adaptation or increased stress tolerance, or are signs of damage. Impacts of moderately elevated O(3) (1.3x ambient) and temperature (ambient + 1 degrees C), alone and in combination, on VOC emissions and leaf structure of two genotypes (2.2 and 5.2) of European aspen (Populus tremula L.) were studied in an open-field experiment in summer 2007. The impact of O(3) on measured variables was minor, but elevated temperature significantly increased emissions of total monoterpenes and green leaf volatiles. Genotypic differences in the responses to warming treatment were also observed. alpha-Pinene emission, which has been suggested to protect plants from elevated temperature, increased from genotype 5.2 only. Isoprene emission from genotype 2.2 decreased, whereas genotype 5.2 was able to retain high isoprene emission level also under elevated temperature. Elevated temperature also caused formation of thinner leaves, which was related to thinning of epidermis, palisade and spongy layers as well as reduced area of palisade cells. We consider aspen genotype 5.2 to have better potential for adaptation to increasing temperature because of thicker photosynthetic active palisade layer and higher isoprene and alpha-pinene emission levels compared to genotype 2.2. Our results show that even a moderate elevation in temperature is efficient enough to cause notable changes in VOC emissions and leaf structure of these aspen genotypes, possibly indicating the effort of the saplings to adapt to changing climate. PMID:19448266

Hartikainen, Kaisa; Nerg, Anne-Marja; Kivimäenpää, Minna; Kontunen-Soppela, Sari; Mäenpää, Maarit; Oksanen, Elina; Rousi, Matti; Holopainen, Toini

2009-09-01

215

Impact of California Reformulated Gasoline on Motor Vehicle Emissions. 2. Volatile Organic Compound Speciation and Reactivity  

Microsoft Academic Search

This paper addresses the impact of California phase 2 reformulated gasoline (RFG) on the composition and reactivity of motor vehicle exhaust and evaporative emissions. Significant changes to gasoline properties that occurred in the first half of 1996 included an increase in oxygen content; decreases in alkene, aromatic, benzene, and sulfur contents; and modified distillation properties. Vehicle emissions were measured in

Thomas W. Kirchstetter; Brett C. Singer; Robert A. Harley; Gary R. Kendall; James M. Hesson

1999-01-01

216

Environmental Chamber Test Protocol for Measuring Chemical Emissions, Including Sulfur Compounds from Drywall with Preliminary Results  

Microsoft Academic Search

Recently, drywall produced in China has been implicated as the cause of health complaints and corrosion of metal components in houses, with sulfur compounds as the potential source. Federal and state agencies are interested in determining if sulfur containing chemicals are being released from this drywall and identifying the compounds. To assist these agencies, as well as product manufacturers and

Stephany I. Mason; Tony Worthan

217

Role of management strategies and environmental factors in determining the emissions of biogenic volatile organic compounds from urban greenspaces.  

PubMed

Biogenic volatile organic compound (BVOC) emissions from urban greenspace have recently become a global concern. To identify key factors affecting the dynamics of urban BVOC emissions, we built an estimation model and utilized the city of Hangzhou in southeastern China as an example. A series of single-factor scenarios were first developed, and then nine multifactor scenarios using a combination of different single-factor scenarios were built to quantify the effects of environmental changes and urban management strategies on urban BVOC emissions. Results of our model simulations showed that (1) annual total BVOC emissions from the metropolitan area of Hangzhou were 4.7 × 10(8) g of C in 2010 and were predicted to be 1.2-3.2 Gg of C (1 Gg = 10(9) g) in our various scenarios in 2050, (2) urban management played a more important role in determining future urban BVOC emissions than environmental changes, and (3) a high ecosystem service value (e.g., lowest BVOC/leaf mass ratio) could be achieved through positive coping in confronting environmental changes and adopting proactive urban management strategies on a local scale, that is, to moderately increase tree density while restricting excessive greenspace expansion and optimizing the species composition of existing and newly planted trees. PMID:24811523

Ren, Yuan; Ge, Ying; Gu, Baojing; Min, Yong; Tani, Akira; Chang, Jie

2014-06-01

218

Influence of the spatial resolution of satellite-derived vegetation parameters on the biogenic Volatile Organic Compounds (VOC) emission modeling  

NASA Astrophysics Data System (ADS)

Vegetation is a natural source of Volatile Organic Compounds (VOC) that plays an important role in atmospheric chemistry. The main objective of the current study is to implement a model to quantify process-based VOC emissions from plants that focuses on the relationship between the sensitivity of VOC emission estimates to spatial resolution data, based on scientific knowledge and vegetation dynamics derived from satellite observations. The Normalized Difference Vegetation Index (NDVI) and Leaf Area Index (LAI) were elected to examine this issue using different resolutions of satellite-derived products: 22m from the DEIMOS-1 satellite, and 250m and 1000m provided by MODIS. The study is focused on an area of 80×80km2 in Portugal for 2011. Detailed land cover and meteorological data are also included in the emission quantification algorithm. The primary outcomes were determined using a multi-scale analysis showing spatial and temporal variations in the vegetation parameters and modeling results. The results confirm that the emissions model is highly sensitive to the spatial resolution of the satellite-derived data, resulting in about a 30% difference in total isoprene emissions for the study area.

Silveira, Carlos M. S.; Tchepel, Oxana A.

2014-03-01

219

Sectoral emission inventories of greenhouse gases for 1990 on a per country basis as well as on 1°×1°  

Microsoft Academic Search

A set of global greenhouse gas emission inventories has been compiled per source category for the 1990 annual emissions of the direct greenhouse gases CO2, CH4 and N2O, as well as of the indirect greenhouse gases (ozone precursors) CO, NOx and NMVOC, and of SO2. The inventories are available by sector, both on a per country\\/region basis and on a

J. G. J. Olivier; A. F. Bouwman; J. J. M. Berdowski; C. Veldt; J. P. J. Bloos; A. J. H. Visschedijk; C. W. M. van der Maas; P. Y. J. Zandveld

1999-01-01

220

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

221

Influences of chlorine content on emission of HCl and organic compounds in waste incineration using fluidized beds.  

PubMed

HCl and some organic compounds are the precursors of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) in municipal solid waste incinerators. In this work, a lab-scale fluidized bed incinerator is adopted to study the relationship between the organic and the inorganic chlorine contents of artificial wastes and the emissions of HCl and organic compounds. The lower threshold limit (LTL) of chlorine content below which HCl and organic compounds are not generated is studied. Experimental results showed that organic chlorides had a greater potential to release chlorine than inorganic chlorides. The generation of organic pollutants fell, but the emissions of HCl increased with the temperature. The concentrations of chlorophenols (CPs)/chlorobenzenes (CBs) increased with chlorine contents. No LTL existed for HCl regardless of whether CaO was added. The LTL for CPs was between 0.1 and 0.3wt% of inorganic chloride, but there was none for organic sources. For CBs, the LTL was between 0.5 and 1.0wt% for inorganics at 700 and 800 degrees C, but 0.1-0.3 wt% at 700 degrees C and 0.3-0.5 wt% at 800 degrees C for organics. The production of PAHs and benzene, toluene, ethylbenzene and xylene (BTEX) was related to the surplus hydrogen ions that were not reacted with the chlorine. Adding CaO inhibited the production of HCl, CBs and CPs, but did not seriously affect PAHs and BTEX. PMID:17320369

Wey, M Y; Liu, K Y; Yu, W J; Lin, C L; Chang, F Y

2008-01-01

222

Emissions of volatile organic compounds from stationary combustion sources: Numerical modeling capabilities  

SciTech Connect

A collaborative research program initiated to study the emissions of a wide variety of chemical species from stationary combustion systems. These product species have been included in the Clean Air act legislation and their emissions must be rigidly controlled, but there is a need for much better understanding of the physical and chemical mechanisms that produce and consume them. We are using numerical modeling study the chemical reactions and fluid mechanical factors that occur in industrial processes: we are examining systems including premixed and diffusion flames, stirred reactors and plug flow reactors in these modeling studies to establish the major factors leading to emissions of these chemicals. In addition, we are applying advanced laser diagnostic techniques to validate the model predictions and to study the possibilities of developing sophisticated sensors to detect emissions of undesirable species in real time. This paper will discuss the organization of this collaborative effort and its results to date.

Seebold, J.G. [Chevron Research and Technology Co., Richmond, CA (United States); Kee, R.J.; Lutz, A.J. [Sandia National Labs., Albuquerque, NM (United States); Pitz, W.J.; Westbrook, C.K. [Lawrence Livermore National Lab., CA (United States); Senkan, S. [California Univ., Los Angeles, CA (United States)

1992-09-01

223

ANALYSIS OF SOCMI (SYNTHETIC ORGANIC CHEMICAL MANUFACTURING INDUSTRY) VOC (VOLATILE ORGANIC COMPOUND) FUGITIVE EMISSIONS DATA  

EPA Science Inventory

The report gives results of an examination of fugitive emission data from Synthetic Organic Chemical Manufacturing Industry (SOCMI) processing units (Collected under earlier EPA studies) for correlations between process variables and leak frequency. Although line temperature did ...

224

Volcanic Emissions of Halides and Sulfur Compounds to the Troposphere and Stratosphere  

Microsoft Academic Search

Estimates have been made of the annual emissions of HC1, HF, and SO2 to the troposphere and stratosphere from volcanic eruptions. The estimated annual emission rates to the troposphere are 7.5 X 105, 3.8 X 104, and 7.5 X 106 metric tons, respectively, and those to the stratosphere are 2.8 x 104, 1.4 x 10 a, and 2.8 X 105,

Richard D. Cadle

1975-01-01

225

Comparative Study of Automotive, Aircraft and Biogenic Emissions of Aldehydes and Aromatic Compounds  

Microsoft Academic Search

Air samples were collected in three well characterized locations in the city of Rio de Janeiro, Brazil: downtown, the idle\\u000a and taxi way areas of the national airport and an urban forest, where the main emissions are from vehicular, aircraft and\\u000a biogenic sources, respectively. Aldehydes and BTEX concentrations show a characteristic profile which may be attributed to\\u000a the emission sources.

C. S. Guimarães; D. Custodio; R. C. S. de Oliveira; L. S. Varandas; G. Arbilla

2010-01-01

226

Historical gaseous and primary aerosol emissions in the United States from 1990 to 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 (non-methane volatile organic compounds), 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 Emissions 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 equipment 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, NOx, CO and EC (speciation of PM2.5 by SMOKE, Sparse Matrix Operator Kernel Emissions) emissions agree well with the observed changes in ambient SO2, NO2, CO and EC concentrations, suggesting that the various controls on 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.

2013-08-01

227

Plasma Source Development for Effective Dissociation and Abatement of Perfluorinated Compounds for the Reduction of Gas Emissions  

NASA Astrophysics Data System (ADS)

Perfluorinated gas compounds (PFCs) are widely used in the semiconductor industry for etching process and for cleaning of chemical vapor deposition (CVD) systems. However, most of these compounds have very high infrared adsorbance strengths and long life times (i.e. several times greater than carbon dioxide). Thus their emissions can strongly contribute to global warming if left unabated. To reduce PFC emissions, the industry has adopted high power density, sub-atmospheric plasma sources to completely dissociate F-bearing compounds at the point of use or to completely convert PFC emissions within the post process exhaust stream. Many electrodeless plasma sources have been applied including microwave, conventional inductive, and ferrite-based inductive plasma devices. As a general scaling rule, most all of these devices provide effective electric field strengths on the order 1-10 V/cm and power densities of 0.1-10 W/cm3 into electronegative discharges at pressures ranging from 0.1-100 Torr. To explore one contemporary example, we examine the properties a ferrite-based, inductively-coupled plasma source as applied to typical processes used in CVD chamber clean and PFC-based etching processes. Along with the operational properties of this device, we examine mass spectroscopy measurements of residual gases from the source when used to (1) fully dissociate high flows of pure NF3 and mixtures of C3F8/O2 and (2) abate moderate flows of CF4, C2F6 and SF6 in combination with O2 or H2O vapor. Also, we review select plasma engineering topics related to these PFC abatement approaches whose study would greatly advance the performance and cost effectiveness of plasma abatement technology within the industry.

Mahoney, Leonard J.

2001-10-01

228

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

229

Biogenic volatile organic compound emissions (BVOCs). I. Identifications from three continental sites in the U.S.  

PubMed

Vegetation composition and biomass were surveyed for three specific sites in Atlanta, GA; near Rhinelander, WI; and near Hayden, CO. At each research site emissions of biogenic volatile organic compounds (BVOCs) from the dominant vegetation species were sampled by enclosing branches in bag enclosure systems and sampling the equilibrium head space onto multi-stage solid adsorbent cartridges. Analysis was performed using a thermal desorption technique with gas chromatography (GC) separation and mass spectrometry (MS) detection. Identification of BVOCs covering the GC retention index range (stationary phase DB-1) from approximately 400 to 1400 was achieved (volatilities C4-C14). PMID:10101861

Helmig, D; Klinger, L F; Guenther, A; Vierling, L; Geron, C; Zimmerman, P

1999-04-01

230

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

231

Significant light and temperature dependent monoterpene emissions from European beech (Fagus sylvatica L.) and their potential impact on the European volatile organic compound budget  

Microsoft Academic Search

By using a dynamic branch enclosure system the emission of monoterpenes from European beech (Fagus sylvatica L.) was investigated during two consecutive summer vegetation periods in the years of 2002 and 2003 in Germany. All measurements were performed under field conditions within the framework of the ECHO project (Emission and Chemical Transformation of Biogenic Volatile Organic Compounds, AFO 2000). European

T. Dindorf; U. Kuhn; L. Ganzeveld; G. Schebeske; P. Ciccioli; C. Holzke; R. Köble; G. Seufert; J. Kesselmeier

2006-01-01

232

Emissions of terpenoids, benzenoids, and other biogenic gas-phase organic compounds from agricultural crops and their potential implications for air quality  

NASA Astrophysics Data System (ADS)

Agriculture comprises a substantial fraction of land cover in many regions of the world, including California's San Joaquin Valley, which is out of compliance with state and federal standards for tropospheric ozone and particulate matter (PM2.5). Emissions from vegetation and other biogenic and anthropogenic sources react in the atmosphere to produce ozone and secondary organic aerosol, which comprises a substantial fraction of PM2.5. Using data from three measurement campaigns, we examine emissions of reactive gas-phase organic carbon from agricultural crops and their potential to impact regional air quality relative to anthropogenic emissions in California's San Joaquin Valley. Emission rates for a suite of biogenic terpenoid compounds were measured in a greenhouse for 25 representative crops from California in 2008, and ambient measurements of terpenoids and other biogenic compounds in the volatile and intermediate-volatility organic compound range were made over an orange orchard in a rural area of the San Joaquin Valley during two seasons in 2010: summer and spring flowering. When accounting for both emissions of reactive precursors and the deposition of ozone to an orange orchard, the net effect of the orange trees is a net source of ozone in the springtime during flowering, and relatively neutral for most of the summer until the fall when it becomes a sink. Flowering was a major emission event and caused a large increase in emissions including a suite of compounds that had not been measured in the atmosphere before. Such biogenic emission events need to be better parameterized in models as they have significant potential to impact regional air quality since emissions increase by an order of magnitude. In regions like the San Joaquin Valley, the mass of biogenic emissions from agricultural crops during the summer (without flowering) and the potential ozone and secondary organic aerosol formation from these emissions are on the same order as anthropogenic emissions from motor vehicles and must be considered in air quality models and secondary pollution control strategies.

Gentner, D. R.; Ormeño, E.; Fares, S.; Ford, T. B.; Weber, R.; Park, J.-H.; Brioude, J.; Angevine, W. M.; Karlik, J. F.; Goldstein, A. H.

2013-11-01

233

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

234

Emissions of volatile organic compounds from large?scale incineration plants  

Microsoft Academic Search

This paper gives results of the measurements and evaluation of emissions from seven Swedish incineration plants. The investigated incinerators ranged from 12 to 80 MW, and include Martin grate, Von Roll grate, Overthrust (W+E) grate, Vereinige Kesselwerke (V+K) grate, travelling grate, vibration grate and circulating fluidized bed (CFB) types. The analytical techniques used include online carbon monoxide (CO), nitrogen oxides

X. J. Zhang

1998-01-01

235

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

236

EMISSION OF SULFUR-BEARING COMPOUNDS FROM MOTOR VEHICLE AND AIRCRAFT ENGINES. A REPORT TO CONGRESS  

EPA Science Inventory

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 H2SO4, SO2, sulfate, H2S, and carbonyl sulfide from motor vehicles, motor vehicle engines and aircraft engines; (2) a revie...

237

Acoustic emission analysis as a non-destructive test procedure for fiber compound structures  

NASA Technical Reports Server (NTRS)

The concept of acoustic emission analysis is explained in scientific terms. The detection of acoustic events, their localization, damage discrimination, and event summation curves are discussed. A block diagram of the concept of damage-free testing of fiber-reinforced synthetic materials is depicted. Prospects for application of the concept are assessed.

Block, J.

1983-01-01

238

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

239

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

240

CHARACTERIZATION OF EMISSIONS OF VOLATILE ORGANIC COMPOUNDS FROM INTERIOR ALKYD PAINT  

EPA Science Inventory

Alkyd paint continues to be used indoors for application to wood trim, cabinet surfaces, and some kitchen and bathroom walls. Paint may represent a significant source of volatile organic compounds (VOCs) indoors depending on the frequency of use and amount of surface paint. The U...

241

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

Microsoft Academic Search

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

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

2003-01-01

242

Emissions of volatile organic compounds during the decomposition of plant litter  

Microsoft Academic Search

Volatile organic compounds (VOCs) are emitted during plant litter decomposition, and such VOCs can have wide-ranging impacts on atmospheric chemistry, terrestrial biogeochemistry, and soil ecology. However, we currently have a limited understanding of the relative importance of biotic versus abiotic sources of these VOCs and whether distinct types of litter emit different types and quantities of VOCs during decomposition. We

Christopher M. Gray; Russell K. Monson; Noah Fierer

2010-01-01

243

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

2013-10-01

244

White Paper Highly Reactive Volatile Organic Compound (HRVOC) Emissions from CAFOs  

Microsoft Academic Search

Concentrated animal feeding operations (CAFOs) are facing serious challenges of responding to new regulations soon to be implemented in California limiting emissions of reactive organic gases (ROGs). The justifications for these new regulations are the federal and state (SB700) requirements to bring areas classified as ozone non-attainment into attainment and the time-lines set by EPA. Ozone is formed by reaction

S. Capareda; S. Mukhtar; B. Shaw; C. Parnell; R. Flocchini

245

Control of atmospheric emissions of volatile organic compounds using impregnated active carbons  

Microsoft Academic Search

The combination of carbon adsorption with catalytic complete oxidation for control of emissions of n-hexane, 2,3-dimethylbutane, cyclohexane and benzene is analysed in this paper. The activities of activated carbons prepared with almond shells and impregnated with CoO, Co3O4 and CrO3 were compared, in relation with carbon structure, catalyst content and catalyst species. The microcatalytic–chromatographic technique developed was very suitable for

M. C. M Alvim Ferraz; S Möser; M Tonhäeuser

1999-01-01

246

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

247

Location and characterization of emission sources for airborne volatile organic compounds inside a refinery in Taiwan.  

PubMed

This study aimed to locate VOC emission sources and characterized their emitted VOCs. To avoid interferences from vehicle exhaust, all sampling sites were positioned inside the refinery. Samples, taken with canisters, were analyzed by GC-MS according to TO-14 method. The survey period extended from Febrary 2004 to December 2004, sampling twice per season. To interpret a large number of VOC data was a rather difficult task. This study featured using ordinary application software, Excel and Surfer, instead of expensive one like GIS, to overcome it. Consolidating data into a database on Excel facilitated retrieval, statistical analysis and presentation in the form of either table or graph. The cross analysis of the data suggested that the abundant VOCs were alkanes, alkenes, aromatics and cyclic HCs. Emission sources were located by mapping the concentration distribution of these four types of VOCs in terms of contour maps on Surfer. During eight surveys, five emission sources were located and their VOCs were characterized. PMID:16741796

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

2006-09-01

248

Laser emission from the transition-metal compound LiSrCrF6  

NASA Astrophysics Data System (ADS)

We have demonstrated laser action in the transition-metal compound LiSrCrF6. A Ti:sapphire laser was employed to pump into the long-wavelength absorption wing in order to mimic the AlGaAs laser-diode wavelengths. Slope efficiencies greater than 30 percent were measured with a crystal having passive losses of the order of 3-5 percent/cm.

Smith, Larry K.; Payne, Stephen A.; Krupke, William F.; Deloach, Laura D.; Morris, Robert; O'dell, E. W.; Nelson, D. J.

1993-02-01

249

Serratia odorifera : analysis of volatile emission and biological impact of volatile compounds on Arabidopsis thaliana  

Microsoft Academic Search

Bacteria emit a wealth of volatiles. The combination of coupled gas chromatography\\/mass spectrometry (GC\\/MS) and proton-transfer-reaction\\u000a mass spectrometry (PTR-MS) analyses provided a most comprehensive profile of volatiles of the rhizobacterium Serratia odorifera 4Rx13. An array of compounds, highly dominated by sodorifen (approximately 50%), a bicyclic oligomethyl octadiene, could\\u000a be detected. Other volatiles included components of the biogeochemical sulfur cycle such

Marco Kai; Elena Crespo; Simona M. Cristescu; Frans J. M. Harren; Wittko Francke; Birgit Piechulla

2010-01-01

250

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

Microsoft Academic Search

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

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

2008-01-01

251

Interim 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 briefly summarize the results to date of the off-gas treatment program for atmospheric emissions of chlorinated volatile organic compounds (CVOCs), in particular trichloroethylene (TCE) and perchloroethylene (PCE). This program is part of the Department of Energy`s Office of Technology Development`s Integrated Demonstration for Treatment of Organics in Soil and Water at a Non-Arid Site. The off-gas treatment program was initiated after testing of in-situ air stripping with horizontal wells was completed. That successful test expectedly produced atmospheric emissions of CVOCs that were unabated. It was decided after that test that an off-gas treatment program would complement the Integrated Demonstration not only because 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 US to mitigate CVOC emissions. A single platform for testing off-gas treatment technologies would facilitate systematic and unbiased evaluation of the emerging technologies.

Haselow, J.S.; Jarosch, T.R.; Rossabi, J.; Burdick, S.; Lombard, K.

1993-12-01

252

A new V-shaped organic fluorescent compound integrated with crystallization-induced emission enhancement and intramolecular charge transfer.  

PubMed

The emission behavior of a new V-shaped organic fluorescent compound (p,p?-bis(2-aryl-1,3,4-oxadiazol-5-yl)diphenyl sulfone (OZA-SO)), consisting of diethylamino (donor) and sulfone (acceptor) units, has been studied in various polar solvents and with different morphologies. As expected, there is the gradual transition from the locally excited state to the intramolecular charge-transfer (ICT) state with the increasing solvent polarity. The photoluminescence intensity of OZA-SO initially decreases with a low water fraction (f(w)), owing to ICT effect, and then increases with a high f(w), owing to crystallization-induced emission enhancement. At the same time, the fluorescence lifetime of OZA-SO increases from 0.062?ns in dimethylformamide (DMF) to 5.80?ns in a solution containing 90?% water, and then to 7.49?ns in a solution containing 60?% water. Furthermore, the solid-state emission of OZA-SO can be tuned reversibly from green to yellow by fuming/grinding or fuming/heating owing to morphological changes. This color-switchable feature of OZA-SO may have potential applications in optical-recording and temperature-sensing materials. PMID:23821372

Gu, Pei-Yang; Zhang, You-Hao; Liu, Gao-Yan; Ge, Jian-Feng; Xu, Qing-Feng; Zhang, Qichun; Lu, Jian-Mei

2013-09-01

253

Ozone reactivity of biogenic volatile organic compound (BVOC) emissions during the Southeast Oxidant and Aerosol Study (SOAS)  

NASA Astrophysics Data System (ADS)

Recent studies on atmospheric chemistry in the forest environment showed that the total reactivity by biogenic volatile organic compound (BVOC) emission is still not well understood. During summer 2013, an intensive field campaign (Southeast Oxidant and Aerosol Study - SOAS) took place in Alabama, U.S.A. In this study, an ozone reactivity measurement system (ORMS) was deployed for the direct determination of the reactivity of foliage emissions. The ORMS is a newly developed measurement approach, in which a known amount of ozone is added to the ozone-free air sample stream, with the ORMS measuring ozone concentration difference between before and after a glass flask flow tube reaction vessel (2-3 minutes of residence time). Emissions were also collected onto adsorbent cartridges to investigate the discrepancy between total ozone reactivity observation and reactivity calculated from identified BVOC. Leaf and canopy level experiments were conducted by deploying branch enclosures on the three dominant tree species at the site (i.e. liquidambar, white oak, loblolly pine) and by sampling ambient air above the forest canopy. For the branch enclosure experiments, BVOC emissions were sampled from a 70 L Teflon bag enclosure, purged with air scrubbed for ozone, nitrogen oxides. Each branch experiment was performed for 3-5 days to collect at least two full diurnal cycle data. In addition, BVOCs were sampled using glass tube cartridges for 2 hours during daytime and 3 - 4 hours at night. During the last week of campaign, the inlet for the ORMS was installed on the top of scaffolding tower (~30m height). The ozone loss in the reactor showed distinct diurnal cycle for all three tree species investigated, and ozone reactivity followed patterns of temperature and light intensity.

Park, J.; Guenther, A. B.; Helmig, D.

2013-12-01

254

Non-methane volatile organic compounds predict odor emitted from five tunnel ventilated broiler sheds.  

PubMed

Non-methane volatile organic compounds (NMVOCs) emitted from mechanically ventilated poultry sheds in similar stages (32-36 d) of broiler production were measured by thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS), then identified using parallel factor analysis (PARAFAC2) and the NIST11 database. Calibration models predicting odor measured by dilution olfactometry from NMVOC concentrations via orthogonal projection to latent structures (O-PLS) made good predictions (Rp(2)=0.83-0.87, RMSEp=137-175OU) using one to eight NMVOCs with either one or two latent variables representing odor concentration and character, respectively. Similar changes in odorant composition were observed in each sampling campaign, with samples collected early in the day more odorous and more sulfurous than samples collected later in the day. High litter moisture favored sulfur-containing odorants over alcohols, aldehydes and ketones but had little bearing on perceived odor, whereas high bird density favored alcohols, aldehydes and ketones over sulfur-containing odorants. Eight VOCs that were important predictors of odor across all sheds in order of decreasing importance were dimethyl sulfide (DMS), dimethyl trisulfide (DMTS), 2-3 butanedione, 3-methyl-butanal, 1-butanol, 3-methyl-1-butanol, acetoin, and 2-butanone. Four additional NMVOCs also influenced perceived odor although less predictably; these were n-hexane, 2-butanol, dimethyl disulfide (DMDS), and 1-octen-3-ol. All of the odorants are associated with microbial or fungal activity in the litter and manure, except n-hexane, which may originate from hexane-extracted soybean meal in the chicken feed. The organosulfides measured in this study may have arisen from the field sites as well as from the degradation of thiols captured on sorbent tubes during analysis by TD-GC/MS. PMID:24188627

Murphy, Kathleen R; Parcsi, Gavin; Stuetz, Richard M

2014-01-01

255

Bright white-light emission from a single organic compound in the solid state.  

PubMed

White-light-emitting materials and devices have attracted enormous interest because of their great potential for various lighting applications. We herein describe the light-emitting properties of a series of new difunctional organic molecules of remarkably simple structure consisting of two terminal 4-pyridone push-pull subunits separated by a polymethylene chain. They were found to emit almost "pure" white light as a single organic compound in the solid state, as well as when incorporated in a polymer film. To the best of our knowledge, they are the simplest white-light-emitting organic molecules reported to date. PMID:24677585

Yang, Qing-Yuan; Lehn, Jean-Marie

2014-04-25

256

Reduction of dioxin-like compound emissions from a Waelz plant with adsorbent injection and a dual baghouse filter system.  

PubMed

Previous study indicates that the polychlorinated dibenzo-p-dioxin and -dibenzofurans (PCDD/F) concentration measured in the stack gas of the Waelz plant investigated reached 194 ng-TEQ/(N m3) (TEQ = toxic equivalence), due to the relatively high potential of PCDD/F formation and a low PCDD/F removal efficiency (<70%) achieved with the baghouse filter (BF). In September 2006, the Taiwan government setthe PCDD/F emission limit for existing Waelz plants as 1.0 ng-I-TEQO/(N m3). The retrofit technology for reducing PCDD/F emissions from the existing Waelz plant was evaluated at the same time. Carbon-type adsorbent injection technology was adopted in early 2006 to reduce the emission of dioxin-like compounds at the Waelz plant investigated. Flue gases and ambient air samplings were conducted during the two stages of retrofit to evaluate the removal efficiency of dioxin-like compounds at the Waelz plant investigated. At stage 1, by applying adsorbent injection + single baghouse filter (SBF), the PCDD/F and polychlorinated biphenyl (PCB) concentrations measured in the stack gas at the Waelz plant were 4.62 ng-TEQ/(N m3) and 0.08 ng-TEQ(WHO)/(N m3) (TEQ(WHO) = World Health Organization TEQ), respectively, as the adsorbent injection rate was controlled at 40 kg/h (or 540 mg/ (N m3)). At stage 2, the PCDD/F and PCB concentration measured at stack gas, achieved with adsorbent injection + dual baghouse filter (DBF) system, were further reduced to 0.235 + 0.04 ng-I-TEQ/(N m3) (I-TEQ = International TEQ) and 0.004 + 0.002 ng-TEQ(WHO)/(N m3) with the adsorbent injection rate at 16 kg/h (or 215 mg/(N m3)). In the meantime, the atmospheric PCDD/F concentrations measured in the vicinity area of the Waelz plant were greatly reduced from 568-1465 to 48.9-130 fg-I-TEQ/m3. Higher removal efficiency (>99.8%) achieved at a lower adsorbent injection rate (16 kg/h) of the adsorbent injection + DBF system also significantly reduced the total PCDD/-F and PCB emission flows (per kg of electric arc furnace dust treated) to 1925 ng-I-TEQ and 30.5 ng-TEQ(WHO), respectively. PMID:18409645

Chi, Kai Hsien; Chang, Shu Hao; Chang, Moo Been

2008-03-15

257

The emission characteristics and the related malodor intensities of gaseous reduced sulfur compounds (RSC) in a large industrial complex  

NASA Astrophysics Data System (ADS)

In this study, the concentrations of major reduced sulfur compounds (RSC: H 2S, CH 3SH, DMS, CS 2 and DMDS) were determined from various emission sources located within the Ban-Wall (BW)/ Si-Hwa (SH) industrial complex in Ansan city, Korea. The measurement data were obtained from a total of 202 individual points at 77 individual companies during 2004-2005. The highest RSC concentration levels came most dominantly from H 2S (300 (mean) and 0.86 ppb (median)) followed by CS 2, while the results of CH 3, DMS, and DMDS are notably lower at the mean concentration levels of a few ppb. These data were evaluated further after being grouped into two different classification schemes: 9 industry sectors and 9 processing unit types. The strongest emissions of RSC, when evaluated among different industry sectors, are generally found from such industry types as leather, food, paper/pulp, as well as waste/sewage related ones. In contrast, when these RSC data are compared across different processing units, the highest values were seen most frequently from such units as junction boxes, aeration tanks, and settling tanks. The assessment of data in terms of relative contribution to malodor intensity showed that H 2S and CH 3SH are more important than others. The overall results of the present study suggest that information combining RSC speciation and types of anthropogenic activities may be used to distinguish the patterns of odorous pollution in areas affected by strong source processes.

Kim, Ki-Hyun; Jeon, Eui-Chan; Choi, Ye-Jin; Koo, Youn-Seo

258

Characterization of Volatile Organic Compound (VOC) Emissions at Sites of Oil Sands Extraction and Upgrading in northern Alberta  

NASA Astrophysics Data System (ADS)

The crude oil reserves in Canada's oil sands are second only to Saudi Arabia, holding roughly 173 billion barrels of oil in the form of bitumen, an unconventional crude oil which does not flow and cannot be pumped without heating or dilution. Oil sands deposits are ultimately used to make the same petroleum products as conventional forms of crude oil, though more processing is required. Hydrocarbons are the basis of oil, coal and natural gas and are an important class of gases emitted into the atmosphere during oil production, particularly because of their effects on air quality and human health. However, they have only recently begun to be independently assessed in the oil sands regions. As part of the 2008 ARCTAS airborne mission, whole air samples were collected in the boundary layer above the surface mining operations of northern Alberta. Gas chromatography analysis revealed enhanced concentrations of 53 VOCs (C2 to C10) over the mining region. When compared to local background levels, the measured concentrations were enhanced up to 1.1-400 times for these compounds. To more fully characterize emissions, ground-based studies were conducted in summer 2010 and winter 2011 in the oil sands mining and upgrading areas. The data from the 200 ground-based samples revealed enhancements in the concentration of 65 VOCs. These compounds were elevated up to 1.1-3000 times above background concentrations and include C2-C8 alkanes, C1-C5 alkyl nitrates, C2-C4 alkenes and potentially toxic aromatic compounds such as benzene, toluene, and xylenes.

Marrero, J.; Simpson, I. J.; Meinardi, S.; Blake, D. R.

2011-12-01

259

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

260

Analysis of the emissions of volatile organic compounds from the compression ignition engine fueled by diesel–biodiesel blend and diesel oil using gas chromatography  

Microsoft Academic Search

This paper describes the procedures of the analysis of pollutant gases, as volatile organic compounds (benzene, toluene, ethylbenzene, o-xylene, m-xylene and p-xylene) emitted by engines, using high-resolution gas chromatography (HRGC). In a broad sense, CI engine burning diesel was compared with B10 and a drastic reduction was observed in the emissions of the aromatic compounds by using B10. Especially for

S. L. Ferreira; A. M. dos Santos; G. R. de Souza; W. L. Polito

2008-01-01

261

Detection of organic compound signatures in infra-red, limb emission spectra observed by the MIPAS-B2 balloon instrument  

Microsoft Academic Search

Organic compounds play a central role in troposphere chemistry and increasingly are a viable target for remote sensing observations. In this paper, infra-red spectral features of three organic compounds are investigated in thermal emission spectra recorded on a flight on 8 May 1998 near Aire sur l'Adour by a balloon-borne instrument, MIPAS-B2, operating at high spectral resolution. It is demonstrated,

J. J. Remedios; G. Allen; A. M. Waterfall; H. Oelhaf; A. Kleinert; D. P. Moore

2007-01-01

262

Erbium-ytterbium-yttrium compounds for light emission at 1.54microm  

NASA Astrophysics Data System (ADS)

Silicon microphotonics? has emerged as the leading technology to overcome the interconnect bottleneck that limits a further increase of computation power following Moore's law. Optical interconnects between different electronic microprocessors in an electronic-photonic integrated circuit (EPIC) can provide a fast, low-loss and highbandwidth alternative to electrical interconnects, which suffer from issues such as resistive heating, RC delays and channel crosstalk at an increasing device density. A crucial device in such an electronic-photonic integrated circuit is a compact, highgain and low power optical amplifier to compensate for signal attenuation due to propagation losses and to recover signal strength after subsequent 3dB splits during fanout of the optical signal to different microprocessors. Erbium ions (Er3+) are an excellent candidate to provide amplification around .. = 1.54pm for optical telecommunications. Erbium-doped fiber amplifiers (EDFAs) have already enabled long-haul optical data. transmission through silica optical fibers, but scaling down a fiber amplifier to an on-chip erbium-doped waveguide amplifier (EDWA) brings along significant materials and device design challenges. In this thesis, erbium-ytterbium oxide (Erx Yb2-xO 3) and erbium-ytterbium-yttrium silicate (ErxYhyY 2-x-ySi2O7) compounds are investigated as novel materials systems for the development of EDWAs. The high erbium and ytterbium solubility (>1022 cm-3) and refractive index (1.71 < n < 1.92) make these materials excellent candidates for compact, low-power optical amplifiers. Erx Yb2-xO 3 and ErxYhyY2-x-ySi2O 7 thin films were deposited on SiO2 and analyzed structurally and optically. The role of ytterbium in these compounds is twofold. First, ytterbium can be used as an alternative to yttrium for dilution of the erbium concentration in order to mitigate parasitic concentration quenching effects. Second, ytterbium acts as a sensitizer for erbium during optical pumping at lambda = 980nm. Comparison of the different oxide and silicate thin films reveals that the alpha-disilicate phase is the best candidate for an EDWA gain medium pumped at lambda = 980nm. By means of rate and propagation equations, the composition of an Er xYhyY2-x-ySi2O7 gain medium was optimized for application as a 3dB EDWA. The optimal composition was found to be Er0.025Yb0.200Yb0.200Y1.775Si 2O7, which provides a 1.5dB/cm gain at only 3mW of pump power. In terms of the figure of merit 3dB gain/(device area ? pump power), this material outperforms other EDWA materials reported in literature. (Copies available exclusively from MIT Libraries, libraries.mit.edu/docs - docs mit.edu)

Vanhoutte, Michiel

263

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

264

Emissions of terpenoids, benzenoids, and other biogenic gas-phase organic compounds from agricultural crops and their potential implications for air quality  

NASA Astrophysics Data System (ADS)

Agriculture comprises a substantial, and increasing, fraction of land use in many regions of the world. Emissions from agricultural vegetation and other biogenic and anthropogenic sources react in the atmosphere to produce ozone and secondary organic aerosol, which comprises a substantial fraction of particulate matter (PM2.5). Using data from three measurement campaigns, we examine the magnitude and composition of reactive gas-phase organic carbon emissions from agricultural crops and their potential to impact regional air quality relative to anthropogenic emissions from motor vehicles in California's San Joaquin Valley, which is out of compliance with state and federal standards for tropospheric ozone PM2.5. Emission rates for a suite of terpenoid compounds were measured in a greenhouse for 25 representative crops from California in 2008. Ambient measurements of terpenoids and other biogenic compounds in the volatile and intermediate-volatility organic compound ranges were made in the urban area of Bakersfield and over an orange orchard in a rural area of the San Joaquin Valley during two 2010 seasons: summer and spring flowering. We combined measurements from the orchard site with ozone modeling methods to assess the net effect of the orange trees on regional ozone. When accounting for both emissions of reactive precursors and the deposition of ozone to the orchard, the orange trees are a net source of ozone in the springtime during flowering, and relatively neutral for most of the summer until the fall, when it becomes a sink. Flowering was a major emission event and caused a large increase in emissions including a suite of compounds that had not been measured in the atmosphere before. Such biogenic emission events need to be better parameterized in models as they have significant potential to impact regional air quality since emissions increase by several factors to over an order of magnitude. In regions like the San Joaquin Valley, the mass of biogenic emissions from agricultural crops during the summer (without flowering) and the potential ozone and secondary organic aerosol formation from these emissions are on the same order as anthropogenic emissions from motor vehicles and must be considered in air quality models and secondary pollution control strategies.

Gentner, D. R.; Ormeño, E.; Fares, S.; Ford, T. B.; Weber, R.; Park, J.-H.; Brioude, J.; Angevine, W. M.; Karlik, J. F.; Goldstein, A. H.

2014-06-01

265

From emissions to ambient mixing ratios: on-line seasonal field measurements of volatile organic compounds over a Norway spruce dominated forest in central Germany  

NASA Astrophysics Data System (ADS)

Biogenic volatile organic compounds (BVOC) are substantial contributors to atmospheric chemistry and physics and demonstrate the close relationship between biosphere and atmosphere. Their emission rates are highly sensitive to meteorological and environmental changes with concomitant impacts on atmospheric chemistry. We have investigated seasonal isoprenoid and oxygenated VOC (oxVOC) fluxes from a Norway spruce (Picea abies) tree in Central Germany and explored the emission responses under various atmospheric conditions. Emission rates were quantified by using dynamic branch enclosure and Proton Transfer Reaction-Mass Spectrometry (PTR-MS) techniques. Additionally, ambient mixing ratios were derived through application of a new box model treatment on the dynamic chamber measurements. These are compared in terms of abundance and origin with the corresponding emissions. Isoprenoids govern the BVOC emissions from Norway spruce, with monoterpenes and sesquiterpenes accounting for 50.8 ± 7.2% and 19.8 ± 8.1% respectively of the total emissions. Normalizing the VOC emission rates, we have observed a trend of reduction of carbon containing emissions from April to November, with an enhancement of oxVOC. Highest emission rates were observed in June for all measured species, with the exception of sesquiterpenes that were emitted most strongly in April. We exploit the wide range of conditions experienced at the site to filter the dataset with a combination of temperature, ozone and absolute humidity values in order to derive the emission potential and temperature dependency development for the major chemical species investigated. A profound reduction of monoterpene emission potential (E30) and temperature dependency (?) was found under low temperature regimes, combined with low ozone levels (E30MT, LTLO3=56 ± 9.1 ng g(dw)-1 h-1, ?MT,LTLO3=0.03±0.01 K-1) while a combination of both stresses was found to alter their emissions responses with respect to temperature substantially (E30MT,HTHO3=1420.1 ± 191.4 ng g(dw)-1 h-1, ?MT,HTHO3=0.15 ± 0.02 K-1). Moreover, we have explored compound relationships under different atmospheric condition sets, addressing possible co-occurrence of emissions under specific conditions. Finally, we evaluate the temperature dependent algorithm that seems to describe the temperature dependent emissions. Highest emission deviations were observed for monoterpenes and these emission fluctuations were attributed to a fraction which is triggered by an additional light dependency.

Bourtsoukidis, E.; Williams, J.; Kesselmeier, J.; Jacobi, S.; Bonn, B.

2013-11-01

266

X-ray Kbeta- and L2,3-emission bands of pure silicon and silicon in Mo-Si compounds  

Microsoft Academic Search

The intensity distribution of Kbeta- and L2,3-emission bands of pure silicon and silicon in MoSi2, Mo5Si3 and Mo3Si are investigated. Some of the aspects of the electronics structure of these compounds are discussed.

V. V. Nemoshkalenko; A. P. Shpak; V. P. Krivitsky; L. I. Nikolajev

1973-01-01

267

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

268

Mass transfer of volatile organic compounds from painting material in a standard field and laboratory emission cell  

Microsoft Academic Search

The field and laboratory emission cell (FLEC) is becoming a standard method of characterizing pollutant emissions from building materials. It is significant to use the emission profiles from FLEC to scale the emissions of building materials in real buildings. The dynamics of mass transfer in such an FLEC are the key to perform this task. In this study, the mass

L. Z. Zhang; J. L. Niu

2003-01-01

269

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

270

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

271

Estimation of biogenic volatile organic compound (BVOC) emissions from the terrestrial ecosystem in China using real-time remote sensing data  

NASA Astrophysics Data System (ADS)

Because of the high emission intensity and reactivity, biogenic volatile organic compounds (BVOCs) play a significant role in the terrestrial ecosystems, human health, secondary pollution, global climate change and the global carbon cycle. Past estimations of BVOC emissions in China were based on outdated algorithms and limited meteorological data, and there have been significant inconsistences between the land surface parameters of dynamic models and those of BVOC estimation models, leading to large inaccuracies in the estimated results. To refine BVOC emission estimations for China and to further explore the role of BVOCs in atmospheric chemical processes, we used the latest algorithms of MEGAN (Model of Emissions of Gases and Aerosols from Nature) with MM5 (the Fifth-Generation Mesoscale Model) providing highly resolved meteorological data, to estimate the biogenic emissions of isoprene (C5H8) and seven monoterpene species (C10H16) in 2006. Real-time MODIS (Moderate Resolution Imaging Spectroradiometer) data were introduced to update the land surface parameters and improve the simulation performance of MM5, and to modify the influence of leaf area index (LAI) and leaf age deviation from standard conditions. In this study, the annual BVOC emissions for the whole country totaled 12.97 Tg C, a relevant value much lower than that given in global estimations but higher than the past estimations in China. Therein, the most important individual contributor was isoprene (9.36 Tg C), followed by ?-pinene (1.24 Tg C yr-1) and ?-pinene (0.84 Tg C yr-1). Due to the considerable regional disparity in plant distributions and meteorological conditions across China, BVOC emissions presented significant spatial-temporal variations. Spatially, isoprene emission was concentrated in South China, which is covered by large areas of broadleaf forests and shrubs. On the other hand, Southeast China was the top-ranking contributor of monoterpenes, in which the dominant vegetation genera consist of evergreen coniferous forests (mainly Pinus massoniana). Temporally, BVOC emissions primarily occurred in July and August during periods of high temperatures, high solar radiation and dense plant cover, with daily emissions peaking at about 13:00~14:00 hours (Beijing Time, BJT) and reaching their lowest values at night. Additionally, emissions of volatile organic compounds (VOCs) of biogenic origin (14.7 Tg yr-1) were approximately one-third less than anthropogenic emissions (23.2 Tg yr-1) and showed distinct spatial distributions. We present a reasonable estimation of BVOC emissions, which provides important information for further exploration of the role of BVOCs in atmospheric processes.

Li, M.; Huang, X.; Li, J.; Song, Y.

2012-04-01

272

The contribution of vehicular emission to the atmospheric concentrations of carbon compounds in the Metropolitan Area of Sao Paulo  

NASA Astrophysics Data System (ADS)

It is recognized that megacities have regional and global effects on climate, and that aerosols and Green House Gases (GHG) constitute the principal tracer of those effects. Such is the case in the Metropolitan Area of Sao Paulo (MASP), one of the largest mega-cities in the world. MASP has a population of almost 20 million inhabitants. The main source of air pollution is the transport sector. In this region, there are approximately 6.5 million passenger cars and commercial vehicles: 85% light duty, 3% heavy-duty diesel vehicles (diesel + 3% bio-diesel) and 12% motorcycles. Of the light duty vehicle, approximately 55% burn a mixture (v/v) of 78% gasoline with 22% ethanol (referred to as gasohol), 4% use hydrated ethanol (95% ethanol + 5% water), 38% flexible fuel vehicles capable of burning both gasohol as hydrated ethanol, and 2% use diesel. In average 50% of the fuel used in MASP is ethanol what brings the necessity of more studies to understand the formation of photochemical oxidants and secondary particles. According to the São Paulo State Environmental Protection Agency, 97% of carbon monoxide (CO), 85% of hydrocarbons (HC), 82% of nitrogen oxides (NOx), 36% of sulfur dioxide emitted, and 36% of all inhalable particulate matter (PM10) are emitted by the vehicular fleet. Concerning particles, 75% of the Fine Particle Concentration is related to the burning of fuel, mainly diesel. The fine particles are composed of Organic Carbon (40%), Black Carbon (30%), ions (15%) and metals. It is known that the soot is warming the climate and is important to the radiative balance. Another important driver to the radiative balance, the CO2 is mainly emitted by the transport sector, which is responsible for 57% of its emission. A comprehensive project under development has the objective of determine the role of MASP as the source of gaseous and particle compounds to the atmosphere of the region and in a mesoscale perspective. The project with funding from the São Paulo Science Foundation, called NARROWING THE UNCERTAINTIES ON AEROSOL AND CLIMATE CHANGES IN SÃO PAULO STATE - NUANCE-SPS, comprising various subprojects, employ measurements and modeling to study gaseous and particles in the atmosphere: sources; evolution in the atmosphere; formation of secondary particles; deposition; and potential impact on the climate and human health. Ground-based and vertical profile measurements are being performed (in situ, ozonesondes and LIDAR). Emission inventory is being elaborated based on the measurements of emission factors from the vehicular fleet. The formation of ozone and fine particles is being modeled with the WRF-Chem (weather and research forecast with chemistry) model. The influence of the megacity emission to the concentration of the secondary pollutants is being evaluated and correlated to health impacts.

Andrade, M.; Fornaro, A.; Miranda, R.; Ynoue, R. Y.; Freitas, E. D.; LAPAt-Laboratorio de Analise dos Processos Atmosfericos

2013-05-01

273

Emissions of volatile and potentially toxic organic compounds from waste-water treatment plants and collection systems (Phase 2). Volume 1. Project summaries. Final report  

SciTech Connect

The objectives of the Phase II research project on emission of potentially toxic organic compounds (PTOCs) from wastewater treatment plants were fivefold: (1) assessment of the importance of gaseous emissions from municipal wastewater collection systems; (2) resolution of the discrepancy between the measured and estimated emissions (Phase I), from the Joint Water Pollution Control Plant (JWPCP) operated by the County Sanitation Districts of Los Angeles County (CSDLAC); (3) determination of airborne concentrations of PTOCS immediately downwind of an activated sludge aeration process at the City of Los Angeles' Hyperion Treatment Plant (HTP); (4) a modeling assessment of the effects of transient loading on emissions during preliminary and primary treatment at a typical municipal wastewater treatment plant (MWTP); (5) a preliminary investigation of effects of chlorination practices on haloform production. Volume 1, for which the abstract was prepared, contains a summary of results from each project; Volume 2 contains the discussion regarding the modeling of collection system emissions; Volume 3 addresses methods development and field sampling efforts at the JWPCP and HTP, data on emissions from a mechanically ventilated sewer and results of some preliminary haloform formation studies in wastewaters; and Volume 4 discusses aspects of the emissions modeling problem.

Chang, D.P.Y.; Schroeder, E.D.; Corsi, R.L.; Guensler, R.; Meyerhofer, J.A.

1991-08-01

274

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

275

Subjective cognition and amyloid deposition imaging: a Pittsburgh Compound B positron emission tomography study in normal elderly individuals  

PubMed Central

Background Subjective cognitive impairment (SCI) as an early clinical manifestation in Alzheimer disease (AD) is a central and highly debated question. Objective To study the relationship between subjective cognition and the neuropathological hallmark of AD, amyloid-beta (A?) deposition, imaged with [11C]-Pittsburg compound B (PiB) - positron emission tomography (PET), in normal elderly individuals. Design Cross-sectional analysis. Subjects Forty-eight cognitively normal elderly subjects (11 with high PiB uptake and 28 with low PiB uptake) were included. All underwent clinical and neuropsychological evaluations and MRI and PET scanning. Results High PiB subjects showed significantly lower performance than low PiB subjects on an episodic memory measure, and were less confident about their general memory abilities when required to evaluate themselves relative to other people of the same age. High and low PiB groups did not differ on the accuracy of their cognitive self-reports compare to objective cognitive performance. General memory self-reports from the whole group were significantly correlated to regional PiB uptake in the right medial prefrontal cortex (PFC)/anterior cingulate cortex (ACC) and in the right precuneus/posterior cingulate cortex (PCC). Reduced confidence about memory abilities was associated with greater PiB in these brain regions. All results are independent of demographic variables and depressive affects. Conclusions Our findings suggest that a decrease of self-confidence about memory abilities in cognitively normal elderly subjects is related to the neuropathological hallmark of AD measured with PiB-PET imaging. The relevance of SCI in the early stages of the AD pathological process is addressed.

Perrotin, Audrey; Mormino, Elizabeth C.; Madison, Cindee M.; Hayenga, Amynta O.; Jagust, William J.

2012-01-01

276

[Polar neutral organic compounds (POCN) in city aerosols. 2. Measuring of emissions from domestic fuel and vehicle exhaust and from immission particles in Berlin (West)].  

PubMed

During April and May 1985, some emission samples from private coal firing (domestic fuel) were taken and were fired with two different kind of coal (bituminous and brown coal). Also, measurements were done under different combustion conditions (low and high concentrations of oxygenium during the combustion process). In June and November 1985, some emission samples from heavy diesel-engines were taken in a special tunnel equipment, at different engine conditions. During September 1985, also suspended particulates in a highway traffic tunnel were taken. All these samples were taken using high volume cascade impactors which give a fractionation of the suspended particulates into different particle sizes, according to their retention behaviour in the human respiratory system. The results of these emission samples and samples in the highway tunnel were compared with prior immission measurements of urban suspended particulates in Berlin-West, during January 1984. The etherextractable organic matter (= EEOM) of the total suspended particulate matter (= TPM) was determined using ultrasonic extraction method. The EEOM was separated into an acidic (= AF), a basic (= BF) and a neutral fraction (= NF) by dissolution in acidic and basic agents. Of the neutral fraction (NF), further separation was done into aliphatic compounds (= AIP), polycyclic aromatic hydrocarbons (= PAH) and polar neutral organic compounds (POCN) by using thin layer chromatography. From the PAH and POCN, single compounds were identified by gas chromatographic analysis with dual capillary collumns and internal standard method. All organic fractions were tested to their mutagenic activity in the Salmonella typhimurium mammalian microsome bioassay by Ames. The following results were gained: the neutral fraction (NF) made the highest part of the EEOM (greater than or equal to 60%) whereas the part of the AF amounted to 10-25% and of the basic fraction (BF) to approximatively 5-20%. Making further separation of the NF, some differences between the emission sources were gained. Now, the AIP amounted to a percentage of ca. 15% of the NF for coal firing emissions and to ca. 20-40% for diesel-emissions and samples in the highway tunnel. The percentages of the PAH and POCN varied in dependence of the combustion conditions on both emission sources and amounted to 20-50% for the PAH and 30-50% for the POCN. The gas chromatographic analysis showed also differences between the two emission sources. So, for coal firing emissions, higher concentrations for phenanthrene, benzo(a)-pyrene and dibenz(a.h)anthracene (for PAH) and 9-fluorenone (for POCN) were gained.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2448974

Moriske, H J; Freise, R; Schneider, C; Rüden, H

1987-10-01

277

Evolution and Transport of Pollutants over a Mediterranean Coastal Area: The Influence of Biogenic Volatile Organic Compound Emissions on Ozone Concentrations.  

NASA Astrophysics Data System (ADS)

A computational simulation of a typical sea-breeze situation and the transport and evolution of photochemical pollutants on the Spanish east coast is performed, and the influence of biogenic volatile organic compound (BVOC) emissions on the ozone concentrations formed is studied. The detailed land cover patterns and the topography of the area have been taken into account with the aid of a geographical information system. A meteorological prognostic simulation is performed as a first step, reproducing successfully the sea-breeze formation and comparing favorably with the observations. A BVOC emissions inventory is constructed for the area, which, in combination with the available anthropogenic emissions, indicates that the study area is more VOC than NOx sensitive with respect to the ozone concentrations formed. Based on the meteorological simulation and emissions inventories, a photochemical dispersion simulation is performed for two cases, with and without the BVOC emissions. The ozone evolution patterns are simulated successfully as compared with the available data. The inclusion of BVOC emissions has a minor effect on the calculated ozone concentrations, except in one case for which the morning peak ozone concentration is captured by the model only if the BVOC emissions are taken into account. This result leads to the conclusion that, under certain circumstances, BVOC can play an important role in ozone formation. The discrepancies in the modeled NOx concentrations are attributed to inaccuracies in the anthropogenic emissions inventory and suggest that the study area may be influenced by external factors that were not taken into account and require further investigation. This study was performed in the framework of the European Commission Biogenic Emissions in the Mediterranean Area (BEMA) project.

Andronopoulos, Spyros; Passamichali, Artemis; Gounaris, Nikos; Bartzis, John G.

2000-04-01

278

Volatile organic compound emissions induced by the aphid Myzus persicae differ among resistant and susceptible peach cultivars and a wild relative.  

PubMed

Little is known on aphid-induced emissions of volatile organic compounds (VOCs) from trees and particularly on their intraspecific variability in association with resistance traits. We compared VOC emissions from five peach cultivars (Prunus persica (L.) Batsch) and a wild relative (Prunus davidiana (Carrière) Franch) that differ in their level (susceptible/resistant) and type (antixenosis, antibiosis) of resistance to the green peach aphid, Myzus persicae (Sulzer). Additionally, the kinetics of VOC induction in response to aphids was compared with that by mechanical wounding. Qualitative and overall quantitative differences among peach genotypes were found in VOC emissions that were mainly composed of methyl-salicylate, farnesenes, (E)-?-ocimene and (E)-4,8-dimethyl-1,3,7-nonatriene. Irrespective of the type of resistance, all resistant genotypes had increased VOC emissions upon aphid attack, while in susceptible genotypes emissions remained low. Emission increases were highest in the genotypes that express increased aphid resistance during second infestations, which had also the highest proportions of methyl-salicylate in their emissions. VOC induction by aphids proceeded slowly with a delay of several hours. Artificial wounding of leaves did not result in emissions of aphid-induced VOCs but caused an immediate burst of green leaf volatiles and benzaldehyde. We conclude that VOC induction in resistant peach cultivars is part of a general defence syndrome that is being avoided or suppressed by M. persicae in the susceptible genotypes. The induction likely involves an aphid-specific elicitor and (methyl)-salicylate in the subsequent signalling and regulation processes that should include gene activation due to the marked delay in the emission response. The results are compared with those of the literature and discussed in view of their ecological and environmental significance. PMID:20739428

Staudt, Micheal; Jackson, Benjamin; El-Aouni, Hanane; Buatois, Bruno; Lacroze, Jean-Philippe; Poëssel, Jean-Luc; Sauge, Marie-Helene

2010-10-01

279

Emission of Biogenic Volatile Organic Compounds: An Overview of Field, Laboratory and Modelling Studies Performed during the `Tropospheric Research Program' (TFS) 1997–2000  

Microsoft Academic Search

The present paper summarises results on the emission of biogenicvolatile organic compounds (BVOC) achieved within the frame of thenational `German Tropospheric Research Programme' (TFS) between 1997 and2000. Field measurements were carried out at the meteorologicalmonitoring station `Hartheimer Wald' located in the vicinity of Freiburg(upper Rhine valley), Germany, within a pine plantation dominated byScots pine (Pinus sylvestris L.). The measured BVOC

J.-P. Schnitzler; N. Bauknecht; N. Brüggemann; W. Einig; R. Forkel; R. Hampp; A. C. Heiden; U. Heizmann; T. Hoffmann; C. Holzke; L. Jaeger; M. Klauer; M. Komenda; R. Koppmann; J. Kreuzwieser; H. Mayer; H. Rennenberg; G. Smiatek; R. Steinbrecher; J. Wildt; W. Zimmer

2002-01-01

280

Exposure to volatile organic compounds for individuals with occupations associated with potential exposure to motor vehicle exhaust and\\/or gasoline vapor emissions  

Microsoft Academic Search

Workers who work near volatile organic compounds (VOCs) source(s), motor vehicle exhausts and\\/or gasoline vapor emissions, are suspected to be exposed to highly-elevated VOC levels during their work-time. This study confirmed this suspicion and evaluated the work-time exposure VOCs for traffic police officers, parking garage attendants, service station attendants, roadside storekeepers and underground storekeepers, by measuring the concentrations of six

Wan-Kuen Jo; Ki-Berm Song

2001-01-01

281

Predicting chemotherapeutic response to small-cell lung cancer of platinum compounds by thallium-201 single-photon emission computerized tomography  

Microsoft Academic Search

Thallium-201 single-photon emission computerized tomography (SPECT) was used to clarify the relationship between 201Tl uptake and the response in chemotherapy to platinum compounds in 21 patients with small-cell lung cancer. 201Tl-SPECT scans were obtained twice: at 15 min (early scan) and 120 min (delayed scan) after an intravenous injection of 111 MBq (3 mCi) of thallium-201 chloride. We obtained the

Y Tokuchi; H Isobe; H Takekawa; T Hanada; T Ishida; S Ogura; K Itoh; M Furudate; K Saito; Y Kawakami

1998-01-01

282

Characterization of low-VOC latex paints: Volatile organic compound content, VOC and aldehyde emissions, and paint performance. Final report, January 1997January 1999  

Microsoft Academic Search

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 and to identify the predominant VOCs and aldehydes in the emissions following application to test substrates. The performance of the paints was evaluated and compared

R. Fortmann; H. C. Lao; A. Ng; N. Roache

1999-01-01

283

Foerbraenningsteknisk minimering av emission av klorerade organiska foereningar vid avfallsfoerbraenning, etapp 1. (Minimization of emission of chlorinated organic compounds at refuse incineration, stage 1).  

National Technical Information Service (NTIS)

This project aims at elucidating which parameters are the most important in 'dioxin'-emission. The study comprises four specific areas: * Development of experimental rig for simulation of refuse boilers. * Development of fuels for simulation of municipal ...

I. Faengmark S. Marklund C. Rappe B. Stroemberg N. Berge

1990-01-01

284

New metal-anion radical framework materials: Co(II) compounds showing ferromagnetic to antiferromagnetic phase transition at about 344 K, and Zn(II) compounds exhibiting terminal anion ligand induced direct white-light-emission.  

PubMed

The preparation, X-ray crystallography, EPR, magnetic and luminescent investigation of new metal-anion radical framework materials based on a new anion radical ligand generated by in situ deprotonation of a stable zwitterionic radical are described herein. N,O,N-tripodal anion radical ligand (bipo(-)?) links metal cations, giving rise to four isostructural one-dimensional metal-organic frameworks, [M(bipo(-)?)(L)](n) [M = Zn, L = HCOO(-) (1), SCN(-) (1a), N(3)(-) (1b); M = Co, L = Br(-) (3)]. The tripodal bipo(-)? ligand and one co-ligand, 1,4-benzenedicarboxylate, coordinate to metals leading to two isostructural two-dimensional metal-organic frameworks, [M(bipo(-)?)(BDC)(0.5)](n) [M = Zn (2) and Co (4)]. The two Co(II) compounds are the first examples that exhibit unusual ferromagnetic to antiferromagnetic phase transition with transition temperature over room temperature, which can be demonstrated by the cooling and warming measurements of susceptibility. Compound 4 also exhibits long-range magnetic ordering with the critical temperature at about 44 K proved by ac susceptibility measurements. The metal-radical frameworks exhibit distinctly different fluorescence emissions. Especially, the isomorphous one-dimensional Zn(II) compounds show interesting terminal anion ligand-induced photoluminescent color changes, including direct and invariable white-light-emission with terminal SCN(-) ligand. PMID:21384049

Yong, Guo-Ping; Li, Ying-Zhou; Li, Chong-Fu; Zhang, Yi-Man; She, Wen-Long

2011-04-28

285

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...

286

Opportunity Analysis for Recovering Energy from Industrial Waste Heat and Emissions  

SciTech Connect

United States industry consumed 32.5 Quads (34,300 PJ) of energy during 2003, which was 33.1% of total U.S. energy consumption (EIA 2003 Annual Energy Review). The U.S. industrial complex yields valuable goods and products. Through its manufacturing processes as well as its abundant energy consumption, it supports a multi-trillion dollar contribution to the gross domestic product and provides millions of jobs in the U.S. each year. Industry also yields waste products directly through its manufacturing processes and indirectly through its energy consumption. These waste products come in two forms, chemical and thermal. Both forms of waste have residual energy values that are not routinely recovered. Recovering and reusing these waste products may represent a significant opportunity to improve the energy efficiency of the U.S. industrial complex. This report was prepared for the U.S. Department of Energy Industrial Technologies Program (DOE-ITP). It analyzes the opportunity to recover chemical emissions and thermal emissions from U.S. industry. It also analyzes the barriers and pathways to more effectively capitalize on these opportunities. A primary part of this analysis was to characterize the quantity and energy value of the emissions. For example, in 2001, the industrial sector emitted 19% of the U.S. greenhouse gases (GHG) through its industrial processes and emitted 11% of GHG through electricity purchased from off-site utilities. Therefore, industry (not including agriculture) was directly and indirectly responsible for emitting 30% of the U.S. GHG. These emissions were mainly comprised of carbon dioxide (CO2), but also contained a wide-variety of CH4 (methane), CO (carbon monoxide), H2 (hydrogen), NMVOC (non-methane volatile organic compound), and other chemicals. As part of this study, we conducted a survey of publicly available literature to determine the amount of energy embedded in the emissions and to identify technology opportunities to capture and reuse this energy. As shown in Table E-1, non-CO2 GHG emissions from U.S. industry were identified as having 2180 peta joules (PJ) or 2 Quads (quadrillion Btu) of residual chemical fuel value. Since landfills are not traditionally considered industrial organizations, the industry component of these emissions had a value of 1480 PJ or 1.4 Quads. This represents approximately 4.3% of the total energy used in the United States Industry.

Viswanathan, Vish V.; Davies, Richard W.; Holbery, Jim D.

2006-04-01

287

Estimation of biogenic volatile organic compound (BVOC) emissions from the terrestrial ecosystem in China using real-time remote sensing data  

NASA Astrophysics Data System (ADS)

Because of the high emission rate and reactivity, biogenic volatile organic compounds (BVOCs) play a significant role in the terrestrial ecosystems, human health, secondary pollution, global climate change and the global carbon cycle. Past estimations of BVOC emissions in China were based on outdated algorithms and coarsely resolved meteorological data, and there have been significant inconsistences between the land surface parameters of dynamic models and those of BVOC estimation models, leading to large inaccuracies in the estimated results. To refine BVOC emission estimations for China and to further explore the role of BVOCs in the atmosphere, we used the latest algorithms of MEGAN (Model of Emissions of Gases and Aerosols from Nature), with MM5 (the Fifth-Generation Mesoscale Model) providing highly resolved meteorological data, to estimate the biogenic emissions of isoprene (C5H8) and seven monoterpene species (C10H16) in 2006. Real-time MODIS (Moderate Resolution Imaging Spectroradiometer) data were introduced to update the land surface parameters and to improve the simulation performance of MM5, and to determine the influence of leaf area index (LAI) and leaf age deviation from standard conditions. In this study, the annual BVOC emissions for the whole country totaled 12.97 Tg C, a relevant value compared with past studies. Therein, the most important individual contributor was isoprene (9.36 Tg C yr-1), followed by ?-pinene (1.24 Tg C yr-1) and ?-pinene (0.84 Tg C yr-1). Due to the considerable regional disparity in plant distributions and meteorological conditions across China, BVOC emissions presented significant spatial and temporal variations. Spatially, isoprene emission was concentrated in South China, which is covered by large areas of broadleaf forests and shrubs. While Southeast China was the top-ranking contributor of monoterpenes, in which the dominant vegetation genera consist of evergreen coniferous forests. Temporally, BVOC emissions primarily occurred in July and August, with daily emissions peaking at about 13:00∼14:00 h (Beijing Time, BJT). In this study, we present an improved estimation of BVOC emissions, which provides important information for further exploration of the role of BVOCs in atmospheric processes.

Li, M.; Huang, X.; Li, J.; Song, Y.

2012-03-01

288

Analysis of C 1, C 2, and C 10 through C 33 particle-phase and semi-volatile organic compound emissions from heavy-duty diesel engines  

NASA Astrophysics Data System (ADS)

To meet increasingly stringent regulations for diesel engines, technologies such as combustion strategies, aftertreatment components, and fuel composition have continually evolved. The emissions reduction achieved by individual aftertreatment components using the same engine and fuel has been assessed and published previously ( Liu et al., 2008a,b,c). The present study instead adopted a systems approach to evaluate the net effect of the corresponding technologies for model-year 2004 and 2007 engines. The 2004 engine was equipped with an exhaust gas recirculation (EGR) system, while the 2007 engine had an EGR system, a crankcase emissions coalescer, and a diesel particulate filter. The test engines were operated under the transient federal test procedure and samples were collected with a source dilution sampling system designed to stimulate atmospheric cooling and dilution conditions. The samples were analyzed for elemental carbon, organic carbon, and C 1, C 2, and C 10 through C 33 particle-phase and semi-volatile organic compounds. Of the more than 150 organic species analyzed, the largest portion of the emissions from the 2004 engine consisted of formaldehyde, acetaldehyde, and naphthalene and its derivatives, which were significantly reduced by the 2007 engine and emissions technology. The systems approach in this study simulates the operation of real-world diesel engines, and may provide insight into the future development of integrated engine technology. The results supply updated information for assessing the impact of diesel engine emissions on the chemical processes, radiative properties, and toxic components of the atmosphere.

Gerald Liu, Z.; Berg, Devin R.; Vasys, Victoria N.; Dettmann, Melissa E.; Zielinska, Barbara; Schauer, James J.

289

Measurement of fugitive volatile organic compound emissions from a petrochemical tank farm using open-path Fourier transform infrared spectrometry  

NASA Astrophysics Data System (ADS)

Fugitive emission of air pollutants is conventionally estimated based on standard emission factors. The Vertical Radial Plume Mapping (VRPM) technique, as described in the US EPA OTM-10, is designed to measure emission flux by directly monitoring the concentration of the plume crossing a vertical plane downwind of the site of interest. This paper describes the evaluation results of implementing VRPM in a complex industrial setting (a petrochemical tank farm). The vertical plane was constructed from five retroreflectors and an open-path Fourier transform infrared spectrometer. The VRPM configuration was approximately 189.2 m in width × 30.7 m in height. In the accompanying tracer gas experiment, the bias of the VRPM estimate was less than 2% and its 95% confidence interval contained the true release rate. Emission estimates of the target VOCs (benzene, m-xylene, o-xylene, p-xylene, and toluene) ranged from 0.86 to 2.18 g s-1 during the 14-day field campaign, while estimates based on the standard emission factors were one order of magnitude lower, possibly leading to an underestimation of the impact of these fugitive emissions on air quality and human health. It was also demonstrated that a simplified 3-beam geometry (i.e., without one dimensional scanning lines) resulted in higher uncertainties in the emission estimates.

Wu, Chang-Fu; Wu, Tzong-gang; Hashmonay, Ram A.; Chang, Shih-Ying; Wu, Yu-Syuan; Chao, Chun-Ping; Hsu, Cheng-Ping; Chase, Michael J.; Kagann, Robert H.

2014-01-01

290

Measurements of volatile organic compounds at a suburban ground site (T1) in Mexico City during the MILAGRO 2006 campaign: Measurement comparison, emission ratios, and source attribution  

SciTech Connect

Volatile organic compound (VOC) mixing ratios were measured with two different instruments at the T1 ground site in Mexico City during the Megacity Initiative: Local and Global Research Observations (MILAGRO) campaign in March of 2006. A gas chromatograph with flame ionization detector (GC-FID) quantified 18 light alkanes, alkenes and acetylene while a proton-transfer-reaction ion-trap mass spectrometer (PIT-MS) quantified 12 VOC species including oxygenated VOCs (OVOCs) and aromatics. A GC separation system was used in conjunction with the PIT-MS (GC-PIT-MS) to evaluate PIT-MS measurements and to aid in the identification of unknown VOCs. The VOC measurements are also compared to simultaneous canister samples and to two independent proton-transfer-reaction mass spectrometers (PTR-MS) deployed on a mobile and an airborne platform during MILAGRO. VOC diurnal cycles demonstrate the large influence of vehicle traffic and liquid propane gas (LPG) emissions during the night and photochemical processing during the afternoon. Emission ratios for VOCs and OVOCs relative to CO are derived from early-morning measurements. Average emission ratios for non-oxygenated species relative to CO are on average a factor of {approx}2 higher than measured for US cities. Emission ratios for OVOCs are estimated and compared to literature values the northeastern US and to tunnel studies in California. Positive matrix factorization analysis (PMF) is used to provide insight into VOC sources and processing. Three PMF factors were distinguished by the analysis including the emissions from vehicles, the use of liquid propane gas and the production of secondary VOCs + long-lived species. Emission ratios to CO calculated from the results of PMF analysis are compared to emission ratios calculated directly from measurements. The total PIT-MS signal is summed to estimate the fraction of identified versus unidentified VOC species.

Bon, D.M.; Springston, S.; M.Ulbrich, I.; de Gouw, J. A.; Warneke, C.; Kuster, W. C.; Alexander, M. L.; Baker, A.; Beyersdorf, A. J.; Blake, D.; Fall, R.; Jimenez, J. L., Herndon, S. C.; Huey, L. G.; Knighton, W. B.; Ortega, J.; Vargas, O.

2011-03-16

291

Differences in source emission rates of volatile organic compounds in inner-city residences of New York City and Los Angeles.  

PubMed

The Toxics Exposure Assessment Columbia-Harvard (TEACH) Project characterized personal, indoor, and outdoor concentrations of a suite of volatile organic compounds (VOCs) for high school students living in New York City (NYC) and Los Angeles (LA). This paper presents the analysis of VOC measurements collected indoors and outdoors for 46 students' homes in NYC and for 41 students' homes in LA across two seasons. Dual-sorbent thermal desorption tubes were used for the collection of 15 VOCs and C(18) 2,4-dinitrophenylhydrazine-coated cartridges were used for the collection of seven aldehydes. Air-exchange rates (AERs) were also measured using a perfluorocarbon tracer gas method. The AERs were lower in the winter in both cities, averaging 1 h(-1) in NYC and 1.4 h(-1) in LA, compared with 1.8 h(-1) in NYC in the summer and 2.5 h(-1) in LA in the fall. Higher AERs were generally associated with lower indoor-outdoor ratios with significant differences for the compounds with indoor sources, including chloroform, 1,4-dichlorobenzene, and formaldehyde. Using a mass-balance model to account for AER and other housing parameters, effective source emission rates (SER) were calculated for each compound. Based on I/O ratios and source emission rates, VOCs could be divided into: (1). indoor-source-influenced compounds, (2). those with contributions from both indoor and outdoor sources, and (3). those with mostly outdoor sources. Significant indoor sources were found for the following six compounds (mean emission rates presented): chloroform (0.11 mg/h), 1,4-dichlorobenzene (19 mg/h), formaldehyde (5 mg/h), acetaldehyde (2 mg/h), benzaldehyde (0.6 mg/h), and hexaldehyde (2 mg/h). Although chloroform had variable I/O ratios across seasons, SERs, which accounted for AER, were similar in both cities for both seasons (e.g., LA means 0.12 and 0.11 mg/h in winter and fall, respectively). Formaldehyde had substantially higher indoor emission rates in the summer in NYC compared to winter (3.8 vs. 1.6 mg/h) but lower in the fall in LA compared to winter (4.3 vs. 5.0 mg/h). Uncertainty analysis determined that source strength calculations were not sensitive to measurement error for a subset of homes in LA. PMID:15118751

Sax, Sonja N; Bennett, Deborah H; Chillrud, Steven N; Kinney, Patrick L; Spengler, John D

2004-01-01

292

The influence of ozone precursor emissions from four world regions on tropospheric composition and radiative climate forcing  

NASA Astrophysics Data System (ADS)

Ozone (O3) precursor emissions influence regional and global climate and air quality through changes in tropospheric O3 and oxidants, which also influence methane (CH4) and sulfate aerosols (SO42-). We examine changes in the tropospheric composition of O3, CH4, SO42- and global net radiative forcing (RF) for 20% reductions in global CH4 burden and in anthropogenic O3 precursor emissions (NOx, NMVOC, and CO) from four regions (East Asia, Europe and Northern Africa, North America, and South Asia) using the Task Force on Hemispheric Transport of Air Pollution Source-Receptor global chemical transport model (CTM) simulations, assessing uncertainty (mean ± 1 standard deviation) across multiple CTMs. We evaluate steady state O3responses, including long-term feedbacks via CH4. With a radiative transfer model that includes greenhouse gases and the aerosol direct effect, we find that regional NOx reductions produce global, annually averaged positive net RFs (0.2 ± 0.6 to 1.7 ± 2 mWm-2/Tg N yr-1), with some variation among models. Negative net RFs result from reductions in global CH4 (-162.6 ± 2 mWm-2 for a change from 1760 to 1408 ppbv CH4) and regional NMVOC (-0.4 ± 0.2 to -0.7 ± 0.2 mWm-2/Tg C yr-1) and CO emissions (-0.13 ± 0.02 to -0.15 ± 0.02 mWm-2/Tg CO yr-1). Including the effect of O3 on CO2 uptake by vegetation likely makes these net RFs more negative by -1.9 to -5.2 mWm-2/Tg N yr-1, -0.2 to -0.7 mWm-2/Tg C yr-1, and -0.02 to -0.05 mWm-2/Tg CO yr-1. Net RF impacts reflect the distribution of concentration changes, where RF is affected locally by changes in SO42-, regionally to hemispherically by O3, and globally by CH4. Global annual average SO42- responses to oxidant changes range from 0.4 ± 2.6 to -1.9 ± 1.3 Gg for NOxreductions, 0.1 ± 1.2 to -0.9 ± 0.8 Gg for NMVOC reductions, and -0.09 ± 0.5 to -0.9 ± 0.8 Gg for CO reductions, suggesting additional research is needed. The 100-year global warming potentials (GWP100) are calculated for the global CH4 reduction (20.9 ± 3.7 without stratospheric O3 or water vapor, 24.2 ± 4.2 including those components), and for the regional NOx, NMVOC, and CO reductions (-18.7 ± 25.9 to -1.9 ± 8.7 for NOx, 4.8 ± 1.7 to 8.3 ± 1.9 for NMVOC, and 1.5 ± 0.4 to 1.7 ± 0.5 for CO). Variation in GWP100 for NOx, NMVOC, and CO suggests that regionally specific GWPs may be necessary and could support the inclusion of O3 precursors in future policies that address air quality and climate change simultaneously. Both global net RF and GWP100 are more sensitive to NOx and NMVOC reductions from South Asia than the other three regions.

Fry, Meridith M.; Naik, Vaishali; West, J. Jason; Schwarzkopf, M. Daniel; Fiore, Arlene M.; Collins, William J.; Dentener, Frank J.; Shindell, Drew T.; Atherton, Cyndi; Bergmann, Daniel; Duncan, Bryan N.; Hess, Peter; MacKenzie, Ian A.; Marmer, Elina; Schultz, Martin G.; Szopa, Sophie; Wild, Oliver; Zeng, Guang

2012-04-01

293

Emission, oxidation, and secondary organic aerosol formation of volatile organic compounds as observed at Chebogue Point, Nova Scotia  

Microsoft Academic Search

We report the detection of a class of related oxygenated compounds by proton-transfer-reaction mass-spectrometry (PTR-MS) that have rarely or never been observed as a group using in situ instrumentation. Measurements were made as part of the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) 2004 in Chebogue Point, Nova Scotia. The detected class of compounds discussed here includes

R. Holzinger; D. B. Millet; B. Williams; A. Lee; N. Kreisberg; S. V. Hering; J. Jimenez; J. D. Allan; D. R. Worsnop; A. H. Goldstein

2007-01-01

294

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

295

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

296

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

297

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

298

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...

299

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...

300

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...

301

USE OF BIOASSAY-DIRECTED CHEMICAL ANALYSIS FOR IDENTIFYING MUTAGENIC COMPOUNDS IN URBAN AIR AND COMBUSTION EMISSIONS  

EPA Science Inventory

Bioassay-directed chemical analysis fractionation has been used for 30 years to identify mutagenic classes of compounds in complex mixtures. Most studies have used the Salmonella (Ames) mutagenicity assay, and we have recently applied this methodology to two standard reference sa...

302

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

303

Experimental Study of the Shape Equilibration and Fission of the Compound Nucleus sup 161 Ho Accompanying alpha Emission.  

National Technical Information Service (NTIS)

In the system 200 MeV sup 37 Cl+ sup 124 Sn the angular correlation of the alpha particles emitted before fission in coincidence with fission fragments was measured relatively to the spin direction of the compound-nucleus system sup 161 Ho*. Identificatio...

B. Lindl

1985-01-01

304

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

305

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

306

Bioassay-Directed Chemical Analysis of Organic Extracts of Emissions from a Laboratory-Scale Incinerator: Combustion of Surrogate Compounds  

Microsoft Academic Search

A prototype\\/laboratory-scale rotary kiln (73 kW, 250000Btu\\/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 (CCl4), PE + PVC, and TOL + CCl4. The dichloromethane-extractable organics from particles (collected

DAVID M. DeMARINI; RON W. WILLIAMS; ERICA PERRY; PAUL M. LEMIEUX; WILLIAM P. LINAK

1992-01-01

307

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

2012-03-01

308

Volatile organic compound emissions from the oil and natural gas industry in the Uinta Basin, Utah: point sources compared to ambient air composition  

NASA Astrophysics Data System (ADS)

The emissions of volatile organic compounds (VOCs) associated with oil and natural gas production in the Uinta Basin, Utah were measured at a ground site in Horse Pool and from a NOAA mobile laboratory with PTR-MS instruments. The VOC compositions in the vicinity of individual gas and oil wells and other point sources such as evaporation ponds, compressor stations and injection wells are compared to the measurements at Horse Pool. High mixing ratios of aromatics, alkanes, cycloalkanes and methanol were observed for extended periods of time and short-term spikes caused by local point sources. The mixing ratios during the time the mobile laboratory spent on the well pads were averaged. High mixing ratios were found close to all point sources, but gas wells using dry-gas collection, which means dehydration happens at the well, were clearly associated with higher mixing ratios than other wells. Another large source was the flowback pond near a recently hydraulically re-fractured gas well. The comparison of the VOC composition of the emissions from the oil and natural gas wells showed that wet gas collection wells compared well with the majority of the data at Horse Pool and that oil wells compared well with the rest of the ground site data. Oil wells on average emit heavier compounds than gas wells. The mobile laboratory measurements confirm the results from an emissions inventory: the main VOC source categories from individual point sources are dehydrators, oil and condensate tank flashing and pneumatic devices and pumps. Raw natural gas is emitted from the pneumatic devices and pumps and heavier VOC mixes from the tank flashings.

Warneke, C.; Geiger, F.; Edwards, P. M.; Dube, W.; Pétron, G.; Kofler, J.; Zahn, A.; Brown, S. S.; Graus, M.; Gilman, J.; Lerner, B.; Peischl, J.; Ryerson, T. B.; de Gouw, J. A.; Roberts, J. M.

2014-05-01

309

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

Microsoft Academic Search

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.

D. R. Gentner; A. H. Goldstein

2010-01-01

310

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

311

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

312

In vitro-in vivo study on the effects of plant compounds on rumen fermentation, microbial abundances and methane emissions in goats.  

PubMed

Two in vitro and one in vivo experiments were conducted to investigate the effects of a selection of plant compounds on rumen fermentation, microbial concentration and methane emissions in goats. Treatments were: control (no additive), carvacrol (CAR), cinnamaldehyde (CIN), eugenol (EUG), propyl propane thiosulfinate (PTS), propyl propane thiosulfonate (PTSO), diallyl disulfide (DDS), a mixture (40 : 60) of PTS and PTSO (PTS+PTSO), and bromochloromethane (BCM) as positive control with proven antimethanogenic effectiveness. Four doses (40, 80, 160 and 320 µl/l) of the different compounds were incubated in vitro for 24 h in diluted rumen fluid from goats using two diets differing in starch and protein source within the concentrate (Experiment 1).The total gas production was linearly decreased (P<0.012) by all compounds, with the exception of EUG and PTS+PTSO (P? 0.366). Total volatile fatty-acid (VFA) concentration decreased (P? 0.018) only with PTS, PTSO and CAR, whereas the acetate:propionate ratio decreased (P? 0.002) with PTS, PTSO and BCM, and a tendency (P=0.064) was observed for DDS. On the basis of results from Experiment 1, two doses of PTS, CAR, CIN, BCM (160 and 320 µl/l), PTSO (40 and 160 µl/l) and DDS (80 and 320 µl/l) were further tested in vitro for 72 h (Experiment 2). The gas production kinetics were affected (P? 0.045) by all compounds, and digested NDF (DNDF) after 72 h of incubation was only linearly decreased (P? 0.004) by CAR and PTS. The addition of all compounds linearly decreased (P? 0.009) methane production, although the greatest reductions were observed for PTS (up to 96%), DDS (62%) and BCM (95%). No diet-dose interaction was observed. To further test the results obtained in vitro, two groups of 16 adult non-pregnant goats were used to study in vivo the effect of adding PTS (50, 100 and 200 mg/l rumen content per day) and BCM (50, 100 and 160 mg/l rumen content per day) during the 9 days on methane emissions (Experiment 3). The addition of PTS and BCM resulted in linear reductions (33% and 64%, respectively, P? 0.002) of methane production per unit of dry matter intake, which were lower than the maximum inhibition observed in vitro (87% and 96%, respectively). We conclude that applying the same doses in vivo as in vitro resulted in a proportional lower extent of methane decrease, and that PTS at 200 mg/l rumen content per day has the potential to reduce methane emissions in goats. Whether the reduction in methane emission observed in vivo persists over longer periods of treatments and improves feed conversion efficiency requires further research. PMID:24237672

Martínez-Fernández, G; Abecia, L; Martín-García, A I; Ramos-Morales, E; Hervás, G; Molina-Alcaide, E; Yáñez-Ruiz, D R

2013-12-01

313

Analysis of organic compounds by particle beam/hollow cathode atomic emission spectroscopy:? determinations of carbon and hydrogen in amino acids.  

PubMed

A detailed evaluation of the analytical characteristics of a particle beam/hollow cathode glow discharge atomic emission spectroscopy (PB/HC-AES) system is described for applications in the area of organic sample analysis. The optimization of sample introduction, nebulization parameters, and glow discharge conditions was performed for the elemental analysis (focusing on C and H) of a group of amino acids. By use of a high-efficiency thermoconcentric nebulizer, analyte particles are introduced into a heated hollow cathode glow discharge source, in either flow injection or continuous-flow mode, for subsequent vaporization/atomization and excitation. Nebulization temperature, solvent composition, and liquid flow rate were studied to elucidate their roles in the ultimate analyte emission characteristics for organic compound analysis. The hollow cathode operating discharge current and gas pressure were optimized, with the general responses found to be similar to those for the case of metal analysis. Background interferences from solvent and additive media on carbon and hydrogen determinations were studied and substantially reduced. The analytical response curves for carbon and hydrogen present in amino acids were obtained using 200 ?L injection volumes, showing less than 10% RSD for replicate injections over a concentration range of 10-250 ppm, with detection limits of 3 and 1 ppm, respectively, for C (I) and H (I) emission. Subsequent studies of the response of carbon and hydrogen emission signal intensities to differences in amino acid stoichiometries suggest a capability of the PB/HC-AES system for the determination of empirical formulas based on H (I)/C (I) intensity ratios. PMID:21639264

You, J; Dempster, M A; Marcus, R K

1997-09-01

314

Emissions from India's transport sector: Statewise synthesis  

NASA Astrophysics Data System (ADS)

A decentralized emission inventories are prepared for road transport sector of India in order to design and implement suitable technologies and policies for appropriate mitigation measures. Globalization and liberalization policies of the government in 90's have increased the number of road vehicles nearly 92.6% from 1980-1981 to 2003-2004. These vehicles mainly consume non-renewable fossil fuels, and are a major contributor of green house gases, particularly CO 2 emission. This paper focuses on the statewise road transport emissions (CO 2, CH 4, CO, NO x, N 2O, SO 2, PM and HC), using region specific mass emission factors for each type of vehicles. The country level emissions (CO 2, CH 4, CO, NO x, N 2O, SO 2 and NMVOC) are calculated for railways, shipping and airway, based on fuel types. In India, transport sector emits an estimated 258.10 Tg of CO 2, of which 94.5% was contributed by road transport (2003-2004). Among all the states and Union Territories, Maharashtra's contribution is the largest, 28.85 Tg (11.8%) of CO 2, followed by Tamil Nadu 26.41 Tg (10.8%), Gujarat 23.31 Tg (9.6%), Uttar Pradesh 17.42 Tg (7.1%), Rajasthan 15.17 Tg (6.22%) and, Karnataka 15.09 Tg (6.19%). These six states account for 51.8% of the CO 2 emissions from road transport.

Ramachandra, T. V.; Shwetmala

315

Electrothermal vaporization — inductively coupled plasma-atomic emission spectrometry for trace metal determination in uranium and thorium compounds without prior matrix separation  

NASA Astrophysics Data System (ADS)

The electrothermal vaporization (ETV) mode of sample introduction into inductively coupled plasma (ICP) has been examined for its suitability for the analysis of trace metals in uranium and thorium compounds without prior chemical separation of the matrices using atomic emission spectrometry (AES). The ETV interfaced with an ICP torch adapted for glove box operation, has led to determination of sub-nanogram amounts of Al, Be, Ca, Cd, Co, Cr, Cu, Mg, Mn, Na, Ni, Zn, Dy, Eu, Gd and Sm using 10 ?l of the sample aliquot containing 200 ?g of U/Th matrix with a precision of 1-2%RSD. The results obtained here especially for rare earths in the presence of the matrix are of significance.

Purohit, Paru J.; Goyal, Neelam; Thulasidas, S. K.; Page, A. G.; Sastry, M. D.

2000-08-01

316

Optical Emission Spectrometry of Plasma in Low-Damage Sub-100 nm Tungsten Gate Reactive Ion Etching Process for Compound Semiconductor Transistors  

NASA Astrophysics Data System (ADS)

In this study, we investigate in situ optical emission spectra from plasma in the reactive ion etching (RIE) of tungsten, a suitable candidate for gate metallization in compound-semiconductor-based high-mobility channel devices. This results in a detailed understanding of the effects of etching parameters vital to reducing etch induced damage and improving etching performance. A SF6 based chemistry was used with other functional gases, such as N2, O2, and CHF3. Van de Pauw (VdP) structures on GaAs based high electron mobility transistor (HEMT) layer structures were used for evaluating plasma-induced damage in the RIE process. The optimised process results in a maximum increase of 15% in the sheet resistance of the semiconductor material. Etched tungsten line widths down to 25 nm with well controlled profile were obtained by adjusting the etching conditions based on the understanding of the etching mechanism.

Li, Xu; Zhou, Haiping; Wilkinson, Chris D. W.; Thayne, Iain G.

2006-10-01

317

Atmospheric emissions and attenuation of non-methane organic compounds in cover soils at a French landfill.  

PubMed

In addition to methane (CH(4)) and carbon dioxide (CO(2)), landfill gas may contain more than 200 non-methane organic compounds (NMOCs) including C(2+)-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 CH(4) and NMOCs in the landfill cover soils overlying two types of gas collection systems: a conventional gas collection system with vertical wells and an innovative horizontal gas collection layer consisting of permeable gravel with a geomembrane above it. The 47 NMOCs quantified in the landfill gas samples included primarily alkanes (C(2)-C(10)), alkenes (C(2)-C(4)), halogenated hydrocarbons (including (hydro)chlorofluorocarbons ((H)CFCs)), and aromatic hydrocarbons (BTEXs). In general, both CH(4) and NMOC fluxes were all very small with positive and negative fluxes. The highest percentages of positive fluxes in this study (considering all quantified species) were observed at the hotspots, located mainly along cell perimeters of the conventional cell. The capacity of the cover soil for NMOC oxidation was investigated in microcosms incubated with CH(4) and oxygen (O(2)). The cover soil showed a relatively high capacity for CH(4) oxidation and simultaneous co-oxidation of the halogenated aliphatic compounds, especially at the conventional cell. Fully substituted carbons (TeCM, PCE, CFC-11, CFC-12, CFC-113, HFC-134a, and HCFC-141b) were not degraded in the presence of CH(4) and O(2). Benzene and toluene were also degraded with relative high rates. This study demonstrates that landfill soil covers show a significant potential for CH(4) oxidation and co-oxidation of NMOCs. PMID:18032020

Scheutz, C; Bogner, J; Chanton, J P; Blake, D; Morcet, M; Aran, C; Kjeldsen, P

2008-01-01

318

Standardization of flux chamber and wind tunnel flux measurements for quantifying volatile organic compound and ammonia emissions from area sources at animal feeding operations  

NASA Astrophysics Data System (ADS)

A variety of portable wind tunnels and flux chambers have been used to measure fluxes of volatile organic compounds (VOC) and ammonia (NH3) at animal feeding operations (AFO). However, there has been little regard to the extreme variation and potential inaccuracies caused by air velocity or sweep air flow rates that are either too low or too high to simulate field conditions. There is a need for correction factors to standardize flux chamber and wind tunnel measurements. In this manuscript, we present results of water evaporative flux and VOC flux measurements with the EPA flux chamber and a small wind tunnel. In the EPA flux chamber, water evaporative flux was positively correlated with sweep air flow rate (SAFR) between 1 and 20 L min-1 (r2 = 0.981-0.999) and negatively correlated with sweep air relative humidity between 0 and 80% (r2 = 0.982-0.992). Emissions of gas-film controlled compounds like NH3 and VOC at AFOs were positively correlated with evaporation rates between 0.6 and 2.8 mm d-1. We demonstrate a simple methodology for standardizing and comparing different chamber types by measuring water evaporation within the chamber using a gravimetric mass balance approach under controlled laboratory conditions. A water evaporative flux ratio correction factor (EFRCF) was used to improve the accuracy of field-measured VOC and NH3 chamber flux measurements. In a field study, both the EPA flux chamber (SAFR = 5 L min-1) and small wind tunnel (SAFR = 1 L min-1) underestimated the true field emissions of VOC, with EFRCFs of 2.42 and 3.84, respectively. EFRCFs are recommended for all but the driest of soil and manure conditions.

Parker, David; Ham, Jay; Woodbury, Bryan; Cai, Lingshuang; Spiehs, Mindy; Rhoades, Marty; Trabue, Steve; Casey, Ken; Todd, Rick; Cole, Andy

2013-02-01

319

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

320

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

321

Characterizing Emissions of Volatile Organic Compounds (VOCs) from Oil and Natural Gas Operations in Haynesville, Fayetteville, and Marcellus Shale Regions via Aircraft Observations During SENEX 2013  

NASA Astrophysics Data System (ADS)

The 2013 SENEX (Southeast Nexus) field campaign took place in June and July 2013 with to ascertain how the interaction of natural and anthropogenic emissions influence climate change and air quality throughout the southeastern United States. Five of the research flights utilizing the NOAA WP-3D aircraft focused on areas of intensive oil and natural gas production from various shale plays. These areas included the Haynesville shale in eastern Texas and western Louisiana, the Fayetteville shale in northern Arkansas, and the Marcellus shale in western Pennsylvania. According to the U.S. Energy Information Administration's (EIA) Annual Energy Outlook 2013 report, (1) the Haynesville, Fayetteville, and Marcellus shale collectively account for approximately 75% of the dry shale gas produced in the U.S., and (2) shale gas is expected to provide the largest source of growth in the U.S. natural gas supply over the next few decades. Depending on the particular shale formation, raw natural gas can contain significant amounts of non-methane hydrocarbons in the form of natural gas liquids (e.g., ethane, propane, butanes) and natural gas condensate (e.g., pentanes, cycloalkanes, and aromatics). Trace gases including methane, aromatics, formaldehyde, other oxygenated VOCs, carbon monoxide, and nitrogen oxides were measured by multiple instruments aboard the NOAA WP-3D research aircraft. Up to 72 whole air samples (WAS) were collected in flight and analyzed in the field post-flight for a variety of volatile organic compounds (VOCs). Whole air samples provide a detailed chemical snapshot that can be combined with higher time-resolved measurements in order to provide a more comprehensive chemical analysis. In this presentation, we will compare the emissions composition of the Haynesville, Fayetteville, and Marcellus shale plays to investigate the relative importance of primary VOC emissions on the formation of secondary pollutants such as ozone, oxygenated VOCs, and secondary organic aerosol.

Gilman, J.; Lerner, B. M.; Dumas, M.; Hughes, D.; Jaksich, A.; Hatch, C. D.; Graus, M.; Peischl, J.; Pollack, I. B.; Ryerson, T. B.; Holloway, J.; Trainer, M.; Aikin, K.; Kaiser, J.; Keutsch, F. N.; Wolfe, G. M.; Hanisco, T. F.; Warneke, C.; De Gouw, J. A.

2013-12-01

322

Biologically produced volatile compounds: N2O emissions from the soil and the N2O global budget  

NASA Technical Reports Server (NTRS)

N2O dynamics were studied at the soil-atmosphere interface and their effects on the global N2O budget. Troposphere nitrous oxide (N2O) concentration has increased by 0.2 to 0.4 pct. per year over the period 1975 to 1982, amounting to a net addition to the atmosphere of 2.8 to 5.6 Tg N2O-N per year. This perturbation, if continued into the future, will affect stratospheric chemical cycles, and the thermal balance of the Earth. In turn it will have direct and indirect global effects on the biosphere. The only well documented heat sinks identified to date are the stratospheric photolytic decomposition processes. However, quantitatively, they do not account for all the known sources. Emission from soils is the least understood and most variable component in the N2O budget. An automated field station that will measure N2O fluxes and interchanges over long periods of time is being developed. At each station, the source/sink relations of N2O at the soil-atmosphere interface will be measured and their relations to environmental conditions are documented and quantified. The results from the perennial measurements will generate the data base on which global budgets for N2O will be constructed and related to ecosystem parameters.

Banin, A.; Whitten, R.; Livingston, G.; Lawless, J.

1985-01-01

323

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

SciTech Connect

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 carbitol, and n-methyl-2-pyrrolidinone. A set of field data collected at a Ford Motor Company assembly plant was also analyzed to determine whether data were consistent with the equilibrium phenomenon. The primary findings include: (a) There were more than six orders of magnitude difference in the Henry's law constants among the solvents studied. A solvent with a smaller constant is less easily stripped from water. The Henry's law constants decrease in the following order: toluene and xylenes > methyl ethyl ketone > n-butanol > butyl cellosolve acetate > butyl cellosolve > formaldehyde > butyl carbitol > n-methyl-2-pyrrolidinone. (b) Field data showed accumulation of n-methyl-2-pyrrolidinone and stable concentrations of butyl carbitol, butyl cellosolve, and n-butanol in the paint-sludge pit water during a 2-month period. Stable concentrations indicate a continuous, balanced capture and stripping of the solvents. Data were consistent with measured Henry's law constants. (c) The low Henry's law constant for formaldehyde is the result of the fact that it is hydrated when dissolved in water.

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

2000-02-01

324

Secretions from the ventral eversible gland of Spodoptera exigua caterpillars activate defense-related genes and induce emission of volatile organic compounds in tomato, Solanum lycopersicum  

PubMed Central

Background Plant induced defense against herbivory are generally associated with metabolic costs that result in the allocation of photosynthates from growth and reproduction to the synthesis of defense compounds. Therefore, it is essential that plants are capable of sensing and differentiating mechanical injury from herbivore injury. Studies have shown that oral secretions (OS) from caterpillars contain elicitors of induced plant responses. However, studies that shows whether these elicitors originated from salivary glands or from other organs associated with feeding, such as the ventral eversible gland (VEG) are limited. Here, we tested the hypothesis that the secretions from the VEG gland of Spodoptera exigua caterpillars contain elicitors that induce plant defenses by regulating the expression of genes involved in the biosynthesis of volatile organic compounds (VOCs) and other defense-related genes. To test this hypothesis, we quantified and compared the activity of defense-related enzymes, transcript levels of defense-related genes and VOC emission in tomato plants damaged by S. exigua caterpillars with the VEG intact (VEGI) versus plants damaged by caterpillars with the VEG ablated (VEGA). Results The quantified defense-related enzymes (i.e. peroxidase, polyphenol oxidase, and lipoxigenase) were expressed in significantly higher amounts in plants damaged by VEGI caterpillars than in plants damaged by VEGA caterpillars. Similarly, the genes that encode for the key enzymes involved in the biosynthesis of jasmonic acid and terpene synthase genes that regulate production of terpene VOCs, were up-regulated in plants damaged by VEGI caterpillars. Moreover, the OS of VEGA caterpillars were less active in inducing the expression of defense genes in tomato plants. Increased emissions of VOCs were detected in the headspace of plants damaged by VEGI caterpillars compared to plants damaged by VEGA caterpillars. Conclusion These results suggest that the VEG of S. exigua caterpillars contains elicitors of late plant defense signaling in tomato which trigger defense-related enzymatic activity, regulate expression of defense-related genes, and induce emission of plant VOCs. These signaling cascades may have important ramifications for plant-insect and tritrophic interactions.

2014-01-01

325

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

NASA Astrophysics Data System (ADS)

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 feces and urine. Wet distillers grains with solubles (WDGS) are a by-product of the ethanol industry, and WDGS have become a staple in many beef cattle finishing diets. The objective of this research was to determine specific VOC emissions from frozen feces and urine of cattle fed steam-flaked corn (SFC)-based diets containing 0, 15, 30, or 45% WDGS. No differences in flux were detected across dietary treatments for phenol, indole, skatole, or 4-methylphenol (P > 0.23). Dimethyl disulfide and dimethyl trisulfide flux in feces were not different across treatments (P > 0.35) and the flux of volatile fatty acids (VFA) such as acetic, propionic, isobutyric, butyric, isovaleric, and valeric were not different across treatments (P > 0.25). There was a tendency for dimethyl disulfide flux from urine to be greater for cattle consuming an SFC-based diet with 15% WDGS than the other diets (P = 0.10). Furthermore, flux of acetic, propionic, isobutyric, butyric, and isovaleric acid from the urine were not different (P > 0.61) across dietary treatment. There were no significant differences in odor activity value (OAV) across treatments for feces, and only a tendency for dimethyl disulfide in the feces (P = 0.09). Thus, there was no obvious indication that feeding WDGS in conjunction with SFC affects flux of odor or odorous VOC from beef manure. The summed OAV was three times higher in the urine than feces, and a single odorous compound (4-methylphenol) accounted for 97.6%and 67.3% of the OAV in urine and feces, respectively. Therefore, engineering or dietary strategies to reduce odor from beef cattle manure should focus on controlling or reducing 4-methylphenol concentrations in the urine and feces.

Hales, Kristin E.; Parker, David B.; Cole, N. Andy

2012-12-01

326

Global chemical transport model study of ozone response to changes in chemical kinetics and biogenic volatile organic compounds emissions due to increasing temperatures: Sensitivities to isoprene nitrate chemistry and grid resolution  

Microsoft Academic Search

Global modeling studies show a wide variability in the response of the O3 budget to climate change as projected by applying Intergovernmental Panel on Climate Change scenarios in climate models. We employ sensitivity studies to elucidate the major uncertainties in the response of tropospheric O3 to perturbations in biogenic volatile organic compounds (BVOC) emissions and reaction rate coefficients due to

Akinori Ito; Sanford Sillman; Joyce E. Penner

2009-01-01

327

Monitoring the emission of volatile organic compounds from flowers of Jasminum sambac using solid-phase micro-extraction fibers and gas chromatography with mass spectrometry detection.  

PubMed

Solid-phase micro-extraction (SPME) was studied as a solvent free alternative method for the extraction and characterization of volatile compounds in intact and plucked flowers of Jasminum sambac at different day time intervals using gas chromatography (GC-FID) and gas chromatography-quadrupole mass spectrometry. The analytes identified included alcohols, esters, phenolic compounds, and terpenoids. The main constituents identified in the flower aroma using different fibers were cis-3-hexenyl acetate, (E)-beta-ocimene, linalool, benzyl acetate, and (E,E)-alpha-farnesene. The benzyl acetate proportion decreased from morning to afternoon and then increased in evening collections. PDMS fiber showed a high proportion of (E,E)-alpha-farnesene in jasmine floral aroma. Among other constituents identified, cis-3-hexenyl acetate, linalool, and benzyl acetate were major aroma contributors in plucked and living flowers extracts using PDMS/DVB, Carboxen/PDMS, and DVB/Carboxen/PDMS fibers. PDMS/DVB recorded the highest emission for benzyl acetate while the (E)-beta-ocimene proportion was highest in DVB/Carboxen/PDMS when compared with the rest. The highest linalool content, with increasing proportion from morning to noon, was found using mixed coating fibers. Almost negligible volatile adsorption was recorded for the polyacrylate fiber for intact flower aroma, whereas it was most effective for benzyl acetate, followed by indole under plucked conditions. Moreover, the highest amounts extracted, evaluated from the sum of peak areas, were achieved using Carboxen/PDMS, and DVB/Carboxen/PDMS. Introduction of a rapid, and solvent free SPME method for the analysis of multicomponent volatiles can be successfully employed to monitor the extraction and characterization of flower aroma constituents. PMID:21941909

Pragadheesh, Vppalayam Shanmugam; Yadav, Anju; Chanotiya, Chandan Singh; Rout, Prasanta Kumar; Uniyal, Girish Chandra

2011-09-01

328

Emissions of biogenic volatile organic compounds and subsequent photochemical production of secondary organic aerosol in mesocosm studies of temperate and tropical plant species  

NASA Astrophysics Data System (ADS)

Silver birch (Betula pendula) and three Southeast Asian tropical plant species (Ficus cyathistipula, Ficus benjamina and Caryota millis) from the pantropical fig and palm genera were grown in a purpose-built and environment-controlled whole-tree chamber. The volatile organic compounds emitted from these trees were characterised and fed into a linked photochemical reaction chamber where they underwent photooxidation under a range of controlled conditions (RH ∼65-89%, VOC/NOx ∼3-9 and NOx ∼2 ppbV). Both the gas phase and the aerosol phase of the reaction chamber were monitored in detail using a comprehensive suite of on-line and off-line, chemical and physical measurement techniques. Silver birch was found to be a high monoterpene and sesquiterpene, but low isoprene emitter, and its emissions were observed to produce measureable amounts of SOA via both nucleation and condensation onto pre-existing seed aerosol (YSOA 26-39%). In contrast, all three tropical species were found to be high isoprene emitters with trace emissions of monoterpenes and sesquiterpenes. In tropical plant experiments without seed aerosol there was no measurable SOA nucleation, but aerosol mass was shown to increase when seed aerosol was present. Although principally isoprene emitting, the aerosol mass produced from tropical fig was mostly consistent (i.e., in 78 out of 120 aerosol mass calculations using plausible parameter sets of various precursor specific yields) with condensation of photooxidation products of the minor VOCs co-emitted; no significant aerosol yield from condensation of isoprene oxidation products was required in the interpretations of the experimental results. This finding is in line with previous reports of organic aerosol loadings consistent with production from minor biogenic VOCs co-emitted with isoprene in principally-isoprene emitting landscapes in Southeast Asia. Moreover, in general the amount of aerosol mass produced from the emissions of the principally-isoprene-emitting plants, was less than would be expected from published single-VOC experiments, if co-emitted species were solely responsible for the final SOA mass. Interpretation of the results obtained from the fig data sets, leaves room for a potential role for isoprene in inhibiting SOA formation under certain ambient atmospheric conditions, although instrumental and experimental constraints impose a level of caution in the interpretation of the results. Concomitant gas and aerosol phase composition measurements also provide a detailed overview of numerous key oxidation mechanisms at work within the systems studied and their combined analysis provides insight into the nature of the SOA formed.

Wyche, K. P.; Ryan, A. C.; Hewitt, C. N.; Alfarra, M. R.; McFiggans, G.; Carr, T.; Monks, P. S.; Smallbone, K. L.; Capes, G.; Hamilton, J. F.; Pugh, T. A. M.; MacKenzie, A. R.

2014-06-01

329

Emission profile of 18 carbonyl compounds, CO, CO 2, and NO x emitted by a diesel engine fuelled with diesel and ternary blends containing diesel, ethanol and biodiesel or vegetable oils  

NASA Astrophysics Data System (ADS)

The impact of vehicular emissions on air depends, among other factors, on the composition of fuel and the technology used to build the engines. The reduction of vehicular emissions requires changes in the fuel composition, and improving the technologies used in the manufacturing of engines and for the after-treatment of gases. In general, improvements to diesel engines have targeted not only emission reductions, but also reductions in fuel consumption. However, changes in the fuel composition have been shown to be a more rapid and effective alternative to reduce pollution. Some factors should been taken into consideration when searching for an alternative fuel to be used in diesel engines, such as emissions, fuel stability, availability and its distribution, as well as its effects on the engine durability. In this work, 45 fuel blends were prepared and their stability was evaluated. The following mixtures (v/v/v) were stable for the 90-day period and were used in the emission study: diesel/ethanol - 90/10%, diesel/ethanol/soybean biodiesel - 80/15/5%, diesel/ethanol/castor biodiesel - 80/15/5%, diesel/ethanol/residual biodiesel - 80/15/5%, diesel/ethanol/soybean oil - 90/7/3%, and diesel/ethanol/castor oil - 90/7/3%. The diesel/ethanol fuel showed higher reduction of NO x emission at a lower load (2 kW) when compared with pure diesel. The other fuels showed a decrease of NO x emissions in the ranges of 6.9-75% and 4-85% at 1800 rpm and 2000 rpm, respectively. The combustion efficiencies of the diesel can be enhanced by the addition of the oxygenate fuels, like ethanol and biodiesel/vegetable oil, resulting in a more complete combustion in terms of NO x emission. In the case of CO 2 the decreases were in the ranges of 5-24% and 4-6% at 1800 rpm and 2000 rpm, respectively. Meanwhile, no differences were observed in CO emission. The carbonyl compounds (CC) studied were formaldehyde, acetaldehyde, propionaldehyde, acrolein, acetone, crotonaldehyde, butyraldehyde, butanone, benzaldehyde, isovaleraldehyde, valeraldehyde, o-toluenaldehyde, m-toluenaldehyde, p-toluenaldehyde, hexaldehyde, octaldehyde, 2,5-dimethylbenzaldehyde, and decaldehyde. Among them, formaldehyde, acetaldehyde, acetone, and propionaldehyde showed the highest emission concentrations. When ternary blend contains vegetable oil, there is a strong tendency to increase the emissions of the high weight CC and decrease the emissions of the low weight CC. The highest concentration of acrolein was observed when the fuel contains diesel, ethanol and biodiesel. With the exception of NO x, the use of ternary blended fuels resulted on the increase in the emission rates of the studied compounds.

Guarieiro, Lílian Lefol Nani; de Souza, Amanda Figueiredo; Torres, Ednildo Andrade; de Andrade, Jailson B.

330

Evaluation of the stability of a mixture of volatile organic compounds on sorbents for the determination of emissions from indoor materials and products using thermal desorption/gas chromatography/mass spectrometry.  

PubMed

The standard method for the determination of volatile organic compounds (VOCs) in indoor and test chamber air (ISO 16000-6:2011) specifies sampling onto the sorbent Tenax TA followed by analysis using thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS). The informative Annex D to the standard suggests the use of multi-sorbent samplers to extend the volatility range of compounds which can be determined. The aim of this study was to investigate the storage performance of Tenax TA and two multi-sorbent tubes loaded with a mixture of nine VOCs of relevance for material emissions testing. The sorbent combinations tested were quartz wool/Tenax TA/Carbograph™ 5TD and quartz wool/Tenax TA/Carbopack™ X. A range of loading levels, loading conditions (humidities and air volume), storage times (1-4 weeks) and storage conditions (refrigerated and ambient) were investigated. Longer term storage trials (up to 1 year) were conducted with Tenax TA tubes to evaluate the stability of tubes used for proficiency testing (PT) of material emissions analyses. The storage performance of the multi-sorbent tubes tested was found to be equal to that for Tenax TA, with recoveries after 4 weeks storage of within about 10% of the amounts loaded. No consistent differences in recoveries were found for the different loading or storage conditions. The longer term storage trials also showed good recovery for these compounds, although two other compounds, hexanal and BHT, were found to be unstable when stored on Tenax TA. The results of this study provide confidence in the stability of nine analytes for up to 4 weeks on two multi-sorbent tubes for material emissions testing and the same compounds loaded on Tenax TA sorbent for a recently introduced PT scheme for material emissions testing. PMID:24877978

Brown, Veronica M; Crump, Derrick R; Plant, Neil T; Pengelly, Ian

2014-07-11

331

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

332

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...

333

In-Situ UHV Low Temperature Ballistic-Electron-Emission Microscope for nm-Scale Imaging and Spectroscopy of Novel Compound Semiconductor Materials.  

National Technical Information Service (NTIS)

This report summarizes the status of development of a new in situ, UHV low temperature Ballistic Electron Emission Microscope (BEEM) for study of localized transport through metal semiconductor heterostructures. Phase 1, which involves the development of ...

V. Narayanamurti

1997-01-01

334

Examination of ras oncoproteins in human plasma from healthy controls and workers exposed to petroleum emissions, including benzene-related compounds  

Microsoft Academic Search

Ras oncoproteins in blood plasma from workers exposed to petroleum emissions and unexposed controls were examined from Polish and Estonian samples. Twenty-four workers and 35 unexposed controls were examined from Poland and 97 exposed and 40 unexposed controls from Estonia. Of the Estonian workers, 50 were exposed to benzene in a benzene production plant and 47 to polyaromatic hydrocarbons and

D Anderson; J. A Hughes; M. H Brinkworth; A Cebulska-Wasilewska; E Nizankowska; B Graca; T Veidebaum; K Peltonen; M Sorsa

1999-01-01

335

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 ...

336

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

2011-05-01

337

Influence of olive ( cv Grignano) fruit ripening and oil extraction under different nitrogen regimes on volatile organic compound emissions studied by PTR-MS technique  

Microsoft Academic Search

Volatile organic compounds of extra virgin olive oils obtained from the local Italian cultivar Grignano were measured by proton\\u000a transfer reaction–mass spectrometry (PTR-MS). Oils were extracted by olives harvested at different ripening stages across\\u000a veraison, performing each extraction step and the whole extraction process in nitrogen atmosphere to observe the changes in the volatile\\u000a profiles of the oils. Principal component

Alice Vezzaro; Andrea Boschetti; Rossana Dell’Anna; Roberto Canteri; Mariano Dimauro; Angelo Ramina; Massimo Ferasin; Claudio Giulivo; Benedetto Ruperti

2011-01-01

338

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

2012-11-01

339

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...

340

The Influence of Ozone Precursor Emissions from Four World Regions on Tropospheric Composition and Radiative Climate Forcing  

NASA Technical Reports Server (NTRS)

Ozone (O3) precursor emissions influence regional and global climate and air quality through changes in tropospheric O3 and oxidants, which also influence methane (CH4) and sulfate aerosols (SO4 (sup 2-)). We examine changes in the tropospheric composition of O3, CH4, SO4 (sup 2-) and global net radiative forcing (RF) for 20% reductions in global CH4 burden and in anthropogenic O3 precursor emissions (NOx, NMVOC, and CO) from four regions (East Asia, Europe and Northern Africa, North America, and South Asia) using the Task Force on Hemispheric Transport of Air Pollution Source-Receptor global chemical transport model (CTM) simulations, assessing uncertainty (mean plus or minus 1 standard deviation) across multiple CTMs. We evaluate steady state O3 responses, including long-term feedbacks via CH4. With a radiative transfer model that includes greenhouse gases and the aerosol direct effect, we find that regional NOx reductions produce global, annually averaged positive net RFs (0.2 plus or minus 0.6 to 1.7 2 mWm(sup -2)/Tg N yr(sup -1), with some variation among models. Negative net RFs result from reductions in global CH4 (-162.6 plus or minus 2 mWm(sup -2) for a change from 1760 to 1408 ppbv CH4) and regional NMVOC (-0.4 plus or minus 0.2 to 0.7 plus or minus 0.2 mWm(sup -2)/Tg C yr(sup -1) and CO emissions (-0.13 plus or minus 0.02 to -0.15 plus or minus 0.02 mWm(sup-2)/Tg CO yr(sup-1). Including the effect of O3 on CO2 uptake by vegetation likely makes these net RFs more negative by -1.9 to- 5.2 mWm(sup -2)/Tg N yr(sup -1), -0.2 to -0.7 mWm(sup -2)/Tg C yr(sup -1), and -0.02 to -0.05 mWm(sup -2)/ Tg CO yr(sup -1). Net RF impacts reflect the distribution of concentration changes, where RF is affected locally by changes in SO4 (sup -2), regionally to hemispherically by O3, and globally by CH4. Global annual average SO4 2 responses to oxidant changes range from 0.4 plus or minus 2.6 to -1.9 plus or minus 1.3 Gg for NOx reductions, 0.1 plus or minus 1.2 to -0.9 plus or minus 0.8 Gg for NMVOC reductions, and -0.09 plus or minus 0.5 to -0.9 plus or minus 0.8 Gg for CO reductions, suggesting additional research is needed. The 100-year global warming potentials (GWP(sub 100)) are calculated for the global CH4 reduction (20.9 plus or minus 3.7 without stratospheric O3 or water vapor, 24.2 plus or minus 4.2 including those components), and for the regional NOx, NMVOC, and CO reductions (18.7 plus or minus 25.9 to 1.9 plus or minus 8.7 for NOx, 4.8 plus or minus 1.7 to 8.3 plus or minus 1.9 for NMVOC, and 1.5 plus or minus 0.4 to 1.7 plus or minus 0.5 for CO). Variation in GWP(sub 100) for NOx, NMVOC, and CO suggests that regionally specific GWPs may be necessary and could support the inclusion of O3 precursors in future policies that address air quality and climate change simultaneously. Both global net RF and GWP100 are more sensitive to NOx and NMVOC reductions from South Asia than the other three regions.

Fry, Meridith; Naik, Vaishali; West, J. Jason; Schwarzkopf, M. Daniel; Fiore, Arlene M.; Collins, William J.; Dentener, Frank J.; Shindell, Drew T.; Atherton, Cyndi; Bergmann, Daniel; Duncan, Bryan N.; Hess, Peter; MacKenzie, Ian A.; Marmer, Elina; Schultz, Martin G.; Szopa, Sophie; Wild, Oliver; Zeng, Guang

2012-01-01

341

CONTINUOUS EMISSION MONITORING DEMONSTRATION PROGRAM  

EPA Science Inventory

Continuous emissions monitoring of hazardous and mixed waste thermal treatment processes is desired for verification of emission compliance, process control, and public safety perception. pecies of particular interest include trace metals and organic compounds resulting from inco...

342

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.  

PubMed

Air quality impacts of volatile organic compound (VOC) and nitrogen oxide (NO(x)) emissions from major sources over the northwestern United States are simulated. The comprehensive nested modeling system comprises three models: Community Multiscale Air Quality (CMAQ), Weather Research and Forecasting (WRF), and Sparse Matrix Operator Kernel Emissions (SMOKE). In addition, the decoupled direct method in three dimensions (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 average simulated 8-hr daily maximum O3 concentration is 48.9 ppb, with 1-hr O3 maxima up to 106 ppb (40 km southeast of Seattle). The average simulated PM2.5 (particulate matter with an aerodynamic diameter < 2.5 microm) concentration at the measurement sites is 9.06 microg m(-3), which is in good agreement with the observed concentration (8.06 microg m(-3)). In urban areas (i.e., Seattle, Vancouver, etc.), the model predicts that, on average, a reduction of NO(x) emissions is simulated to lead to an increase in average 8-hr daily maximum O3 concentrations, and will be most prominent in Seattle (where the greatest sensitivity is -O.2 ppb per % change of mobile sources). On the other hand, decreasing NO(x) emissions is simulated to decrease the 8-hr maximum O3 concentrations in remote and forested areas. Decreased NO(x) emissions are simulated to slightly increase PM2.5 in major urban areas. In urban areas, a decrease in VOC emissions will result in a decrease of 8-hr maximum O3 concentrations. The impact of decreased VOC emissions from biogenic, mobile, nonroad, and area sources on average 8-hr daily maximum O3 concentrations is up to 0.05 ppb decrease per % of emission change, each. Decreased emissions of VOCs decrease average PM2.5 concentrations in the entire modeling domain. In major cities, PM2.5 concentrations are more sensitive to emissions of VOCs from biogenic sources than other sources of VOCs. These results can be used to interpret the effectiveness of VOC or NO(x) controls over pollutant concentrations, especially for localities that may exceed National Ambient Air Quality Standards (NAAQS). Implications: The effect of NO(x) and VOC controls on ozone and PM2.5 concentrations in the northwestern United States is examined using the decoupled direct method in three dimensions (DDM-3D) in a state-of-the-art three-dimensional chemical transport model (CMAQ). NO(x) controls are predicted to increase PM2.5 and ozone in major urban areas and decrease ozone in more remote and forested areas. VOC reductions are helpful in reducing ozone and PM2.5 concentrations in urban areas. Biogenic VOC sources have the largest impact on O3 and PM2.5 concentrations. PMID:23155861

Tsimpidi, Alexandra P; Trail, Marcus; Hu, Yongtao; Nenes, Athanasios; Russell, Armistead G

2012-10-01

343

ENDOCRINE DISRUPTING CHEMICAL EMISSIONS FROM COMBUSTION SOURCES: DIESEL PARTICULATE EMISSIONS AND DOMESTIC WASTE OPEN BURN EMISSIONS  

EPA Science Inventory

Emissions of endocrine disrupting chemicals (EDCs) from combustion sources are poorly characterized due to the large number of compounds present in the emissions, the complexity of the analytical separations required, and the uncertainty regarding identification of chemicals with...

344

Characterization of Halyomorpha halys (brown marmorated stink bug) biogenic volatile organic compound emissions and their role in secondary organic aerosol formation.  

PubMed

The formation of aerosols is a key component in understanding cloud formation in the context of radiative forcings and global climate modeling. Biogenic volatile organic compounds (BVOCs) are a significant source of aerosols, yet there is still much to be learned about their structures, sources, and interactions. The aims of this project were to identify the BVOCs found in the defense chemicals of the brown marmorated stink bug Halymorpha halys and quantify them using gas chromatography-mass spectrometry (GC/MS) and test whether oxidation of these compounds by ozone-promoted aerosol and cloud seed formation. The bugs were tested under two conditions: agitation by asphyxiation and direct glandular exposure. Tridecane, 2(5H)-furanone 5-ethyl, and (E)-2-decenal were identified as the three most abundant compounds. H. halys were also tested in the agitated condition in a smog chamber. It was found that in the presence of 100-180 ppm ozone, secondary aerosols do form. A scanning mobility particle sizer (SMPS) and a cloud condensation nuclei counter (CCNC) were used to characterize the secondary aerosols that formed. This reaction resulted in 0.23 microg/ bug of particulate mass. It was also found that these secondary organic aerosol particles could act as cloud condensation nuclei. At a supersaturation of 1%, we found a kappa value of 0.09. Once regional populations of these stink bugs stablilize and the populations estimates can be made, the additional impacts of their contribution to regional air quality can be calculated. PMID:24344570

Solomon, Danielle; Dutcher, Dabrina; Raymond, Timothy

2013-11-01

345

Influence of olive (cv Grignano) fruit ripening and oil extraction under different nitrogen regimes on volatile organic compound emissions studied by PTR-MS technique.  

PubMed

Volatile organic compounds of extra virgin olive oils obtained from the local Italian cultivar Grignano were measured by proton transfer reaction-mass spectrometry (PTR-MS). Oils were extracted by olives harvested at different ripening stages across veraison, performing each extraction step and the whole extraction process in nitrogen atmosphere to observe the changes in the volatile profiles of the oils. Principal component analysis carried out on the full spectral signature of the PTR-MS measurements showed that the stage of ripening has a stronger effect on the global definition of volatile profiles than the use of nitrogen during oil extraction. The fingerprint-like chemical information provided by the spectra were used to construct a heat map, which allowed the dynamical representation of the multivariate nature of mass evolution during the ripening process. This provided the first evidence that some groups of volatile organic compounds displayed a time course of regulation with coordinated increasing or decreasing trends in association with specific stages of fruit ripening. PMID:21225248

Vezzaro, Alice; Boschetti, Andrea; Dell'Anna, Rossana; Canteri, Roberto; Dimauro, Mariano; Ramina, Angelo; Ferasin, Massimo; Giulivo, Claudio; Ruperti, Benedetto

2011-03-01

346

Trends of greenhouse gas emissions from the road transport sector in India.  

PubMed

The road transport sector is the largest consumer of commercial fuel energy within the transportation system in India and accounts for nearly 35% of the total liquid commercial fuel consumption by all sectors. Gasoline and diesel consumption for road transportation have quadrupled between 1980 and 2000 due to about nine times increase in the number of vehicles and four-fold increase in freight and passenger travel demands. The paper elaborates the trends of energy consumption and consequent emissions of greenhouse gases such as CO(2), CH(4) and N(2)O and ozone precursor gases like CO, NO(x) and NMVOC in the road transport sector in India for the period from 1980 to 2000. For the first time, efforts have been made to apportion the fuels, both diesel and gasoline, across different categories of vehicles operating on the Indian roads. In order to generate more comprehensive and complete emission estimates, additionally, other minor fuel types like light diesel oil and fuel oil along with lubricants have also been taken into account. Emission estimates have revealed that nearly 27 Mt of CO(2) were emitted in 1980, increasing to about 105 Mt in 2000. Similar trends have also been observed for other gases. Further scope for improvements in emission estimation is possible by generating country specific emission factors for different vehicle categories and improvement in documentation of fuel consumption at segregated levels by fuel types and vehicle types. PMID:17977579

Singh, Anil; Gangopadhyay, S; Nanda, P K; Bhattacharya, S; Sharma, C; Bhan, C

2008-02-01

347

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

348

Low volatile organic compound paints  

Microsoft Academic Search

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

1991-01-01

349

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

350

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

351

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

352

Reduction on NOx emissions on urban areas by changing specific vehicle fleets: effects on NO2 and O3 concentration  

NASA Astrophysics Data System (ADS)

The largest amount of NOx emissions in urban areas comes from on-road traffic, which is the largest contributor to urban air pollution (Colvile et al., 2001). Currently different strategies are being tested in order to reduce its effects; many of them oriented to the reduction of the unitary vehicles emissions, by alternative fuels use (such as biofuels, natural gas or hydrogen) or introduction of new technologies (such as hybrid electric vehicles or fuel cells). Atmospheric modelling permits to predict their consequences on tropospheric chemistry (Vautard et al., 2007). Hence, this work assesses the changes on NO2 and O3 concentrations when substituting a 10 per cent of the urban private cars fleets by petrol hybrid electric cars (HEC) or by natural gas cars (NGC) in Madrid and Barcelona urban areas (Spain). These two cities are selected in order to highlight the different patterns of pollutants transport (inland vs. coastal city) and the different responses to emissions reductions. The results focus on a typical summertime episode of air pollution, by means of the Eulerian air quality model ARW- WRF/HERMES/CMAQ, applied with high resolution (1-hr, 1km2) since of the complexity of both areas under study. The detailed emissions scenarios are implemented in the HERMES traffic emissions module, based on the Copert III-EEA/EMEP-CORINAIR (Nztiachristos and Samaras, 2000) methodology. The HEC introduction reduces NOx emissions from on-road traffic in a 10.8 per cent and 8.2 per cent; and the NGC introduction in a 10.3 per cent and 7.8 per cent, for Madrid and Barcelona areas, respectively. The scenarios also affect the NMVOCs reduction (ranging from -3.1 to -6.9 per cent), influencing the tropospheric photochemistry through the NOx/NMVOCs ratio. The abatement of the NO photooxidation but also to the reduction on primary NO2 involves a decrease on NO2 levels centred on urban areas. For example, the NO2 24-hr average concentration in downtown areas reduces up to 8 per cent (-6 ?g m-3 on average). The urban areas are VOC-controlled, therefore the reduction on NOx emissions involves a minor increase on tropospheric O3 concentration (Jiménez and Baldasano, 2004), up to 1.5 per cent at some points. Nevertheless, the O3 precursors reduction has positive effects in the downwind areas affected by the urban plume, slightly reducing the O3 levels, but at the regional scale the reduction applied on urban traffic emissions has negligible effects. Both scenarios tested are very similar in terms of emissions reductions and air quality changes, which means that the NOx/NMVOCs ratio do not involve an O3-sensitivity regime variation among scenarios. The HEC scenario is more effective in reducing NO2 levels in urban areas than the NGC scenario (with maximum reductions affecting a larger area) and involves a larger increase in urban O3 concentration.

Goncalves, M.; Jimenez, P.; Baldasano, J.

2007-12-01

353

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

354

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.

1998-06-09

355

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

356

Reducing emissions of carbonyl compounds and regulated harmful matters from a heavy-duty diesel engine fueled with paraffinic/biodiesel blends at one low load steady-state condition  

NASA Astrophysics Data System (ADS)

This study investigated the emissions of carbonyl compounds (CBCs) and regulated harmful matters (traditional pollutants) from an HDDE (heavy-duty diesel engine) at one low load steady-state condition, 24.5% of the max load (40 km h -1), using five test fuels: premium diesel fuel (D100), P100 (100% palm-biodiesel), P20 (20% palm-biodiesel + 80% premium diesel fuel), PF80P20 (80% paraffinic fuel + 20% palm-biodiesel), and PF95P05 (95% paraffinic fuel + 5% palm-biodiesel). Experimental results indicate that formaldehyde was the major carbonyl in the exhaust, accounting for 70.3-75.4% of total CBC concentrations for all test fuels. Using P100 and P20 instead of D100 in the HDDE increased CBC concentrations by 9.74% and 2.89%, respectively. However, using PF80P20 and PF95P05 as alternative fuels significantly reduced CBC concentrations by 30.3% and 24.2%, respectively. Using PF95P05 instead of D100 decreased CBCs by 30.3%, PM by 11.1%, THC by 39.0%, CO by 34.0%, NOx by 24.3%, and CO 2 by 7.60%. The wide usage of paraffinic-palmbiodiesel blends as alternative fuels could protect the environment. However, it should be noted that only one engine operated at one low load steady-state condition was investigated.

Lin, Yuan-Chung; Wu, Tzi-Yi; Ou-Yang, Wen-Chung; Chen, Chung-Bang

357

Polybenzimidazole compounds  

DOEpatents

A PBI compound includes imidazole nitrogens at least a portion of which are substituted with a moiety containing a carbonyl group, the substituted imidazole nitrogens being bonded to carbon of the carbonyl group. At least 85% of the nitrogens may be substituted. The carbonyl-containing moiety may include RCO--, where R is alkoxy or haloalkyl. The PBI compound may exhibit a first temperature marking an onset of weight loss corresponding to reversion of the substituted PBI that is less than a second temperature marking an onset of decomposition of an otherwise identical PBI compound without the substituted moiety. The PBI compound may be included in separatory media. A substituted PBI synthesis method may include providing a parent PBI in a less than 5 wt % solvent solution. Substituting may use more than 5 equivalents in relation to the imidazole nitrogens to be substituted.

Klaehn, John R. (Idaho Falls, ID); Peterson, Eric S. (Idaho Falls, ID); Orme, Christopher J. (Shelley, ID); Jones, Michael G. (Chubbuck, ID); Wertsching, Alan K. (Idaho Falls, ID); Luther, Thomas A. (Idaho Falls, ID); Trowbridge, Tammy L. (Idaho Falls, ID)

2011-11-22

358

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

359

Polybenzimidazole compounds  

DOEpatents

A PBI compound that includes imidazole nitrogens, at least a portion of which are substituted with an organic-inorganic hybrid moiety. At least 85% of the imidazole nitrogens may be substituted. The organic-inorganic hybrid moiety may be an organosilane moiety, for example, (R)Me.sub.2SiCH.sub.2--, where R is selected from among methyl, phenyl, vinyl, and allyl. The PBI compound may exhibit similar thermal properties in comparison to the unsubstituted PBI. The PBI compound may exhibit a solubility in an organic solvent greater than the solubility of the unsubstituted PBI. The PBI compound may be included in separatory media. A substituted PBI synthesis method may include providing a parent PBI in a less than 5 wt % solvent solution. Substituting may occur at about room temperature and/or at about atmospheric pressure. Substituting may use at least five equivalents in relation to the imidazole nitrogens to be substituted or, preferably, about fifteen equivalents.

Klaehn, John R. (Idaho Falls, ID); Peterson, Eric S. (Idaho Falls, ID); Wertsching, Alan K. (Idaho Falls, ID); Orme, Christopher J. (Shelley, ID); Luther, Thomas A. (Idaho Falls, ID); Jones, Michael G. (Pocatello, ID)

2010-08-10

360

Therapeutic compounds  

US Patent & Trademark Office Database

The present invention relates to pyrazolopyridines and imidazopyridines which are inhibitors of the kinase PDK1 and are thus useful for the treatment of myeloproliferative disorders or cancer. The compounds are also useful as inhibitors of other kinases such as FGFR3, NTRK3, RP-S6K and WEE1. Furthermore, the present compounds also selectively inhibit microtubule affinity regulating kinase (MARK) and are therefore useful for the treatment or prevention of Alzheimer's disease.

2013-06-04

361

75 FR 34671 - 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 Consumer Products AGENCY...Delaware concerning the control of volatile organic compounds (VOC). The revision amends...41)--Limiting Emissions of Volatile Organic Compounds from Consumer and...

2010-06-18

362

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

363

Low emission turbo compound engine system  

DOEpatents

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

364

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

365

Low emissions diesel fuel  

DOEpatents

A method and matter of composition for controlling NO{sub x} emissions from existing diesel engines. The method is achieved by adding a small amount of material to the diesel fuel to decrease the amount of NO{sub x} produced during combustion. Specifically, small amounts, less than about 1%, of urea or a triazine compound (methylol melamines) are added to diesel fuel. Because urea and triazine compounds are generally insoluble in diesel fuel, microemulsion technology is used to suspend or dissolve the urea or triazine compound in the diesel fuel. A typical fuel formulation includes 5% t-butyl alcohol, 4.5% water, 0.5% urea or triazine compound, 9% oleic acid, and 1% ethanolamine. The subject invention provides improved emissions in heavy diesel engines without the need for major modifications.

Compere, A.L.; Griffith, W.L.; Dorsey, G.F.; West, B.H.

1998-05-05

366

Compound radiator  

NASA Astrophysics Data System (ADS)

Standard radiator design with a plate facing cold space on one side and the warm spacecraft at the other side suffers from considerable parasitic heat load to the radiator even when the back of the radiator is covered with the best Multi Layer Insulation (MLI) available. In addition, performance of the plate radiator depends crucially on its insulation which might well deteriorate over a long duration mission. In an attempt to address these manifest and potential problems the concept of a compound radiator was worked out. First tests confirm model calculations; the compound radiator marks a very significant improvement over a standard plate radiator.

Thomsen, Knud

1991-12-01

367

Reducing Indoor Air Emissions from Dry-Process Photocopy Machines.  

National Technical Information Service (NTIS)

The paper discusses reducing indoor air emissions from dry-process photocopy machines. These emissions include: volatile organic compounds (VOCs), ozone, and particles. By measuring emissions in a large test chamber, reviewing the literature, and interact...

K. W. Leovic C. M. Northeim J. A. Calcagni L. S. Sheldon D. A. Whitaker

1997-01-01

368

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

369

Magnesium compounds  

USGS Publications Warehouse

Seawater and natural brines accounted for about 63% of US magnesium compounds production during 2000. Premier Services in Florida, Dow Chemical in Michigan, Martin Marietta Magnesia Specialties, and Rohm & Haas recovered dead-burned and caustic-calcined magnesias from seawater. And Premier Services' recoveries, in Nevada, were from magnasite.

Kramer, D. A.

2001-01-01

370

Magnesium compounds  

USGS Publications Warehouse

Seawater and natural brines accounted for about 60 percent of U.S. magnesium compounds production during 2002. Dead-burned and caustic-calcined magnesias were recovered from seawater by Premier Chemicals in Florida. They were also recovered from well brines in Michigan by Dow Chemical, Martin Marietta Magnesia Specialties and Rohm & Haas. And they were recovered from magnesite in Nevada by Premier Chemicals.

Kramer, D. A.

2003-01-01

371

Magnesium compounds  

USGS Publications Warehouse

In 2005, seawater and natural brines accounted for 51% of US magnesium compounds production. World magnesia production was estimated to be 14.5 Mt. Most of the production came from China, North Korea, Russia and Turkey. Although no specific production figures are available, Japan and the United States are estimated to account for almost one-half of the world's capacity from seawater and brines.

Kramer, D. A.

2006-01-01

372

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 ...

373

Magnesium compounds  

USGS Publications Warehouse

Seawater and natural brines accounted for about 60% of US magnesium compounds production in 2001. Dead-burned and caustic-calcined magnesias were recovered from seawater in Florida by Premier Chemicals. They were also recovered from Michigan well brines by Dow Chemical, Martin Marietta Magnesia Specialties and Rohm & Haas. And Premier Chemicals recovered dead-burned and caustic-calcined magnesias from magnesite in Nevada. Reilly Industries and Great Salt Lake Minerals recovered magnesium chloride brines from the Great Salt Lake in Utah.