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1

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

SciTech Connect

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

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

1988-11-01

2

Improve VOC emission predictions  

SciTech Connect

Many refineries and chemical and petrochemical plants have been estimating emissions; more facilities will do emission predictions in the future. Doing a reality check on these results has not always been possible. Many questions arise such as: are these answers reasonable; what are typical estimates from other plants, where are problem sources located? Due to more stringent emission-reporting requirements, many operators need a truer picture of their VOC emission inventory. Tracking VOC emissions has heightened importance because VOC reacts with nitrogen oxides to form ozone, a regulated pollutant. The data analysis points to where critical refinery emission sources may lurk within the facility. Refiners should understand how sources impact VOC levels and source distribution when preparing facility-wide reports.

Siegell, J.H. [Exxon Research and Engineering Co., Florham Park, NJ (United States)

1997-04-01

3

Control VOC emissions  

SciTech Connect

Hydrocarbon processing industry (HPI) operators can select volatile organic compound (VOC) reduction programs more cost-effectively using these suggestions. New environmental regulations mandate reducing VOC emissions from process units because of: (1) their potential ozone-producing reactions in the atmosphere and (2) their perceived risk from exposure. Typical VOC sources are: fugitive equipment leaks; loading/transfer operations; wastewater treatment units; storage tanks. In almost all cases, fugitive equipment leaks are the largest source of hydrocarbons and air toxics. In locations with large uncontrolled marine or product-loading facilities, loading emissions may also be high. Costs for implementing these controls are based on the referenced EPA documents and are likely to vary for specific plant conditions and requirements. The challenge facing HPI operators is selecting the most applicable and cost-effective control systems for the specific emission sources. Balancing VOC-emission reductions with capital investment is a complex problem given the many potential paths to achieve compliance. However, these suggestions provide a framework to comprehensively investigate, develop, evaluate (both for capital costs and level of emission control), implement and review results when planning VOC control strategies.

Siegell, J.H. [Exxon Research and Engineering Co., Florham Park, NJ (United States)

1995-08-01

4

AREA SOURCES OF VOC EMISSIONS AND THEIR CONTRIBUTION TO TROPOSPHERIC OZONE CONCENTRATIONS  

EPA Science Inventory

The paper quantifies the importance of area sources to total volatile organic compound (VOC) emissions, reviews components of EPA/AEERL's non-attainment program, discusses the status of emission control or prevention for several area sources, and reviews some of the regulatory st...

5

EMISSIONS OF NOX, SOX, AND VOC FROM ANTHROPOGENIC SOURCES  

EPA Science Inventory

The paper addresses the compilation of a 1980 emissions inventory for use in the National Acid Precipitation Assessment Program (NAPAP). The current inventory (Version 4.0) contains point source data for 50,200 plants with more than 201,000 emission points and area source data fo...

6

VOC emission source strengths of tankers during refuelling activities determined by spectroscopic remote sensing and inverse dispersion modeling  

Microsoft Academic Search

Tankers are a wide spread and important emission source of VOC's. Up to now emission data are available from measurements inside the storage tanks to investigate explosion protection only. Different emission reduction systems are under discussion such as vapor recovery units. The environmental impact of these alternatives shall be investigated. The VOC emissions of tankers were investigated in a river

Klaus Schaefer; Herbert Hoffmann; Igor Dormuth; Carsten Jahn; Stefan M. Emeis

2002-01-01

7

[Study on foreign regulations and standards of stationary sources VOCs emission control].  

PubMed

By investigating volatile organic compounds (VOCs) emission control regulations and standards of the United States, the European Union and Japan, the suggestions on VOCs emission control and standards formulating in China were presented. Referencing foreign successful environmental management approach and experience, as well as the corresponding regulations and standards, the author believed that China can find a simple and highly effective way for controlling VOCs, through establishing the emission standards system, innovating VOCs emission control approach, improving VOCs emission control efficiency and unifying VOCs monitoring methods. PMID:22468509

Zhang, Guo-Ning; Hao, Zheng-Ping; Jiang, Mei; Wang, Hai-Lin

2011-12-01

8

Anthropogenic sources of VOC in a football stadium: Assessing human emissions in the atmosphere  

NASA Astrophysics Data System (ADS)

Measurements of gas-phase volatile organic compounds (VOCs), aerosol composition, carbon dioxide (CO2), and ozone (O3) were made inside Coface Arena in Mainz, Germany (49°59'3?N, 8°13'27?E) during a football match on April 20 2012. The VOC measurements were performed with a proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS). Observed VOCs could be classified into several distinct source categories including (1) human respiration/breath, (2) ozonolysis of skin oils, and (3) cigarette smoke/combustion. In this work, we present a detailed discussion on the scale and potential impacts of VOCs emitted as a result of these sources and their contributions on local and larger scales. Human emissions of VOCs have a negligible contribution to the global atmospheric budget (˜1% or less) for all those quantified in this study. However, fluxes as high as 0.02 g m-2 h-1 and 2 × 10-4 g m-2 h-1, for ethanol and acetone respectively are observed, suggesting the potential for significant impact on local air chemistry and perhaps regional scales. This study suggests that even in outdoor environments, situations exist where VOCs emitted as a result of human presence and activity are an important component of local air chemistry.

Veres, Patrick R.; Faber, Peter; Drewnick, Frank; Lelieveld, Jos; Williams, Jonathan

2013-10-01

9

VOC emissions of Grey poplar leaves as affected by salt stress and different N sources.  

PubMed

Nitrogen nutrition and salt stress experiments were performed in a greenhouse with hydroponic-cultured, salt-sensitive Grey poplar (Populus x canescens) plants to study the combined influence of different N sources (either 1 mm NO(3) (-) or NH(4)(+)) and salt (up to 75 mm NaCl) on leaf gas exchange, isoprene biosynthesis and VOC emissions. Net assimilation and transpiration proved to be highly sensitive to salt stress and were reduced by approximately 90% at leaf sodium concentrations higher than 1,800 microg Na g dry weight (dw)(-1). In contrast, emissions of isoprene and oxygenated VOC (i.e. acetaldehyde, formaldehyde and acetone) were unaffected. There was no significant effect of combinations of salt stress and N source, and neither NO(3)(-) or NH(4)(+) influenced the salt stress response in the Grey poplar leaves. Also, transcript levels of 1-deoxy-d-xylulose 5-phosphate reductoisomerase (PcDXR) and isoprene synthase (PcISPS) did not respond to the different N sources and only responded slightly to salt application, although isoprene synthase (PcISPS) activity was negatively affected at least in one of two experiments, despite high isoprene emission rates. A significant salt effect was the strong reduction of leaf dimethylallyl diphosphate (DMADP) content, probably due to restricted availability of photosynthates for DMADP biosynthesis. Further consequences of reduced photosynthetic gas exchange and maintaining VOC emissions are a very high C loss, up to 50%, from VOC emissions related to net CO(2) uptake and a strong increase in leaf internal isoprene concentrations, with maximum mean values up to 6.6 microl x l(-1). Why poplar leaves maintain VOC biosynthesis and emission under salt stress conditions, despite impaired photosynthetic CO(2) fixation, is discussed. PMID:18211549

Teuber, M; Zimmer, I; Kreuzwieser, J; Ache, P; Polle, A; Rennenberg, H; Schnitzler, J-P

2008-01-01

10

Using a source-receptor approach to characterise VOC behaviour in a French urban area influenced by industrial emissions  

Microsoft Academic Search

In Part I of this study (Badol C, Locoge N, Leonardis T, Gallo JC. Using a source-receptor approach to characterise VOC behaviour in a French urban area influenced by industrial emissions, Part I: Study area description, data set acquisition and qualitative data analysis of the data set. Sci Total Environ 2007; submitted as companion manuscript.) the study area, acquisition of

Caroline Badol; Nadine Locoge; Jean-Claude Galloo

2008-01-01

11

Improve VOC emission predictions  

Microsoft Academic Search

Many refineries and chemical and petrochemical plants have been estimating emissions; more facilities will do emission predictions in the future. Doing a reality check on these results has not always been possible. Many questions arise such as: are these answers reasonable; what are typical estimates from other plants, where are problem sources located? Due to more stringent emission-reporting requirements, many

Siegell

1997-01-01

12

VOC emission source strengths of tankers during refuelling activities determined by spectroscopic remote sensing and inverse dispersion modeling  

NASA Astrophysics Data System (ADS)

Tankers are a wide spread and important emission source of VOC's. Up to now emission data are available from measurements inside the storage tanks to investigate explosion protection only. Different emission reduction systems are under discussion such as vapor recovery units. The environmental impact of these alternatives shall be investigated. The VOC emissions of tankers were investigated in a river harbor. Fence-line monitoring by Differential Optical Absorption Spectroscopy (DOAS) was performed to investigate different emission sources during activities of tankers in harbors. Benzene, toluene and p-xylene concentrations were measured by a mono-static DOAS using 3 retro-reflectors. The inverse method was applied on the basis of these non-intrusive measurements of effluent concentrations in the exhaust plume and meteorological measurements to determine the emission source strengths. Inversion of effluent's dispersion was performed by a Lagrangian model driven by wind fields of the Eulerian model MISKAM considering influences from buildings and the orography upon the streaming fields. The emission source strengths were determined from unloading and loading of gasoline, from ventilation of storage tanks of tankers into ambient air which is of common practice if the tankers are operated without load or if the tankers are to be refueled with a different product than before and from using the land-site gasoline vapor recovery unit in a tank farm for ventilation.

Schaefer, Klaus; Hoffmann, Herbert; Dormuth, Igor; Jahn, Carsten; Emeis, Stefan M.

2002-02-01

13

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

SciTech Connect

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

Not Available

1989-01-01

14

VOC Emissions From Decomposing Leaf Litter  

NASA Astrophysics Data System (ADS)

The emission of VOCs from the biosphere has a profound effect on the oxidative capacity of the troposphere. Most studies of the flux of reactive carbon from the biosphere have focused on BVOC emissions at leaf and canopy scales with relatively few studies investigating BVOC emissions from soils. Here we present results describing the emissions of a suite of BVOCs from different litter types under different levels of nitrogen availability. To investigate these effects, three biochemically distinct litter types (Deschampsia sp., Acomostylis sp., and Rhododendron sp.) were coarsely ground and incubated in the dark for two months under different nitrogen regimes at optimal conditions for microbial activity. We used proton transfer reaction mass spectrometry and an infrared gas analyzer (IRGA) to monitor BVOC emissions and CO2 production rates throughout the course of the investigation. When different leaf litter types decomposed, they released distinctly different types and quantities of VOCs. However, varying nitrogen availability caused the VOC signature from some litters to change dramatically. We suggest that decomposition of leaf litter could provide a substantive source of reactive carbon to the atmosphere at local and regional scales and hypothesize that nitrogen deposition may play a role in attenuating the release of some reactive species.

Brown, E. M.; Wilkinson, M. J.; Fierer, N.; Monson, R. K.

2007-12-01

15

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...

16

Reducing VOC Press Emission from OSB Manufacturing  

SciTech Connect

Current regulations require industry to meet air emission standards with regard to particulates, volatile organic compounds (VOCs), hazardous air pollutants (HAPs) and other gases. One of many industries that will be affected by the new regulations is the wood composites industry. This industry generates VOCs, HAPs, and particulates mainly during the drying and pressing of wood. Current air treatment technologies for the industry are expensive to install and operate. As regulations become more stringent, treatment technologies will need to become more efficient and cost effective. The overall objective of this study is to evaluate the use of process conditions and chemical additives to reduce VOC/HAPs in air emitted from presses and dryers during the production of oriented strand board.

Dr. Gary D. McGinnis; Laura S. WIlliams; Amy E. Monte; Jagdish Rughani: Brett A. Niemi; Thomas M. Flicker

2001-12-31

17

Simulation Chamber Investigations of Secondary Organic Aerosol Formation From Boreal Tree Emissions: Dependence on VOC Classes  

Microsoft Academic Search

A considerable fraction of the organic aerosol component is of secondary origin, meaning it is formed through oxidation of volatile organic compounds (VOCs). Plant emissions, e.g. monoterpenes and sesquiterpenes, are a major source of VOCs in the troposphere. So far most laboratory and simulation chamber investigations on the potential to form secondary organic aerosols (SOA) from plant emissions focused on

A. Kiendler-Scharr; T. F. Mentel; E. Kleist; T. Hohaus; A. Mensah; C. Spindler; R. Tillmann; R. Uerlings; M. Dal Maso; Y. Rudich; W. Juergen

2008-01-01

18

Wind tunnels vs. flux chambers: Area source emission measurements and the necessity for VOC and odour correction factors  

Technology Transfer Automated Retrieval System (TEKTRAN)

Wind tunnels and flux chambers have been used to measure fluxes of volatile organic compounds (VOC), odour, and ammonia (NH3) with little regard to air velocity or sweep air flow rates. As a result, flux measurements have been highly variable and scientists have been in disagreement as to the better...

19

Assessment of VOC emissions from fiberglass-boat manufacturing. Final report  

SciTech Connect

The report presents an assessment of volatile organic compound (VOC) emissions from fiberglass boat manufacturing. A description of the industry structures is presented, including estimates of the number of facilities, their size, and geographic distribution. The fiberglass boat manufacturing process is described, along with sources and types of VOC emissions. Model plants representative of typical facilities are also described. Estimates of VOC emissions are presented on per plant and national bases. VOC emissions from this industry consist mainly of styrene emission from gel coating and lamination, and acetone or other solvent emissions from clean-up activities. Finally, potential VOC control technologies are evaluated for this industry, including a discussion of technical feasibility. Limited cost data are also presented.

Stockton, M.B.; Kuo, I.R.

1990-05-01

20

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

PubMed

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

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

1998-01-01

21

Biogenic VOC emissions from fresh leaf mulch and wood chips of Grevillea robusta (Australian Silky Oak)  

NASA Astrophysics Data System (ADS)

The emissions of VOC from freshly cut and shredded Grevillea robusta (Australian Silky Oak) leaves and wood have been measured. The VOC emissions from fresh leaf mulch and wood chips lasted typically for 30 and 20 h respectively, and consisted primarily of ethanol, ( E)-2-hexenal, ( Z)-3-hexen-1-ol and acetaldehyde. The integrated emissions of the VOCs were 0.38±0.04 g kg -1 from leaf mulch, and 0.022±0.003 g kg -1 from wood chips. These emissions represent a source of VOCs in urban and rural air that has previously been unquantified and is currently unaccounted for. These VOCs from leaf mulch and wood chips will contribute to both urban photochemistry and secondary organic aerosol formation. Any CH 4 emissions from leaf mulch and wood chips were <1×10 -11 g g dry mass -1 s -1.

Fedele, Rosemary; Galbally, Ian E.; Porter, Nichola; Weeks, Ian A.

22

Receptor modeling approach to VOC emission inventory validation  

SciTech Connect

The chemical-mass-balance (CMB) receptor model is a method for determining specific-source contributions of volatile organic compounds (VOCs) to concentrations of nonmethane organic compounds (NMOCs) measured in the ambient air. Because the method is based on air measurements, it offers an independent check on emission inventories developed by more traditional permit, survey, emission factor, and source-test techniques. This paper reports on the application of the CMB model to speciated NMOC air-measurement data sets collected during the summers of 1984--88 in five US cities: Detroit; Chicago; Beaumont, Tex.; Atlanta; and Washington, D.C. Sources modeled were vehicle tailpipe emissions, fugitive gasoline-vapor emissions, architectural coating solvents, emissions from graphic arts, petroleum refineries, coke ovens, and polyethylene production. Comparisons of the CMB allocation of NMOC to emission inventory allocation of VOC for each city is discussed. Agreement with Environmental Protection Agency inventories for the five cities was generally very good for vehicles. Refinery inventory estimates are lower than CMB estimates by more than a factor of 10 in Chicago and Detroit. Trajectory analysis was used to validate coefficients for coke ovens.

Kenski, D.M.; Wadden, R.A.; Scheff, P.A. [Univ. of Illinois, Chicago, IL (United States); Lonneman, W.A. [Environmental Protection Agency, Research Triangle Park, NC (United States)

1995-07-01

23

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

Microsoft Academic Search

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

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

1985-01-01

24

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

Microsoft Academic Search

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

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

1985-01-01

25

Guidance for Estimating VOC and NOx Emission Changes from MACT Rules.  

National Technical Information Service (NTIS)

This document is intended to help States prepare their emission projections by providing the information needed to determine the level of VOC and NOx reductions expected with the implementation of post-2002 MACT standards where source-specific estimates a...

2007-01-01

26

Anthropogenic VOC speciation in emission inventories: a method for improvement and evaluation  

NASA Astrophysics Data System (ADS)

Volatile organic compounds (VOCs) are important precursor compounds for the formation of ozone and other secondary organic aerosols. Anthropogenic sources of VOCs are dominated by industrial usage and transportation sources, the latter being extremely important in urban areas. Megacities and large urban conglomerations are emission hot spots that exert disproportionately large adverse health effects on the population and surrounding environment, owing to their high population density and concentrated emission sources. Exceedances of ozone air quality standards are a problem in many urban areas. Improvements in the modelling of ozone precursors would benefit our understanding of the impact of changes in emissions and the effect of future legislation on air quality. As many VOCs are extremely reactive in the atmosphere and have high ozone forming potential, improved speciation of VOCs in models could lead to better predictions of ozone levels and secondary organic aerosol formation. Previously, VOC and carbon monoxide (CO) data from urban areas around the world were compared. Significant differences in VOC concentrations were observed, however, when normalized to CO, the VOC-CO ratios were similar for many locations and over time, even as emission reductions were implemented. The largest variation was found in the lighter alkanes due to the use of alternative transportation fuels in various world regions. These ratios were grouped by region and used to develop a new speciation for surface emissions of VOCs, by applying the regional observed VOC-CO ratios to the CO emissions for the urban areas. Urban areas were defined as 150 inhabitants per km2 or greater. Model simulations were performed using the MOZART-4 chemistry transport model to assess the improved speciation of the VOC emissions. The model outputs were compared to urban observational data where available. The impact of the new speciation of the distribution of CO, OH and ozone at the global scale will be discussed. This study is being developed within the framework of the European projects CityZen, MACC, and PEGASOS.

von Schneidemesser, E.; D'angiola, A.; Granier, C.; Monks, P. S.; Law, K.

2011-12-01

27

Pilot and Full Scale Measurements of VOC Emissions from Lumber Drying of Inland Northwest Species  

SciTech Connect

Volatile organic compounds (VOCs) are precursors to ground level ozone. Ground level ozone is the major component of photochemical smog, and has been linked to a variety of adverse health effects. These health effects include cancer, heart disease, pneumonia and death. In order to reduce ground level ozone, VOC emissions are being more stringently regulated. One VOC source that may come under regulation is lumber drying. Drying lumber is known to emit VOC into the atmosphere. This research evaluates the validity of VOC emission measurements from a small-scale kiln to approximate VOC emissions from kilns at commercial mills. We also report emission factors for three lumber species commonly harvested in the northwest United States (Douglas-fir, ponderosa pine, & grand fir). This work was done with a novel tracer ratio technique at a small laboratory kiln and a large commercial lumber drying facility. The measured emission factors were 0.51 g/kgOD for Douglas-fir, 0.7 g/kgOD for ponderosa pine, and 0.15 g/kgOD for grand fir. Aldehyde emission rates from lumber drying were also measured in some experiments. Results indicate that aldehyde emissions can constitute a significant percentage of the total VOC emissions.

Fritz, Brad G.; Lamb, Brian K.; Westberg, Halvor; Folk, Richard; Knighton, B; Grimsrud, E

2004-07-01

28

NATIONAL AND REGIONAL TRENDS IN VOC AND NOX EMISSIONS FROM 1900 TO 1987  

EPA Science Inventory

The paper gives estimates of historic emissions of VOC and NOx for each state of the contiguous U.S. The emissions were estimated for anthropogenic source categories which included transportation sources, external combustion sources, industrial processes, solid waste disposal, an...

29

Effect of outside air ventilation rate on VOC concentrations and emissions in a call center  

SciTech Connect

A study of the relationship between outside air ventilation rate and concentrations of VOCs generated indoors was conducted in a call center. Ventilation rates were manipulated in the building's four air handling units (AHUs). Concentrations of VOCs in the AHU returns were measured on 7 days during a 13-week period. Indoor minus outdoor concentrations and emission factors were calculated. The emission factor data was subjected to principal component analysis to identify groups of co-varying compounds based on source type. One vector represented emissions of solvents from cleaning products. Another vector identified occupant sources. Direct relationships between ventilation rate and concentrations were not observed for most of the abundant VOCs. This result emphasizes the importance of source control measures for limiting VOC concentrations in buildings.

Hodgson, A.T.; Faulkner, D.; Sullivan, D.P.; DiBartolomeo, D.L.; Russell, M.L.; Fisk, W.J.

2002-01-01

30

Simulation Chamber Investigations of Secondary Organic Aerosol Formation From Boreal Tree Emissions: Dependence on VOC Classes  

NASA Astrophysics Data System (ADS)

A considerable fraction of the organic aerosol component is of secondary origin, meaning it is formed through oxidation of volatile organic compounds (VOCs). Plant emissions, e.g. monoterpenes and sesquiterpenes, are a major source of VOCs in the troposphere. So far most laboratory and simulation chamber investigations on the potential to form secondary organic aerosols (SOA) from plant emissions focused on single VOCs such as a-pinene. In this study we investigated the formation and growth of SOA by ozonolysis and/or photo-oxidation of the VOCs emitted by several tree species such as spruce, pine and birch. The experiments were performed in the Plant chamber of the ICG-3 in Jülich under well defined conditions for the plant. VOC emissions were transferred to a reaction chamber which was operated as a continuously stirred tank reactor. SOA formation from the VOCs was initiated by an excess of ozone and OH radicals. The results are compared to a reference study with a-pinene as the only SOA precursor. Our results indicate that the general laboratory approach of studying the formation of SOA from single components can lead to a bias in both the mass yields and the mass spectral signatures observed. Plots of maximum SOA volumes versus the total amount of carbon fed into the reaction chamber led to approximately linear relationships. The intercepts of these plots were seen as threshold for SOA formation. It was observed that this threshold was lower for the mixture of VOCs emitted from spruce, pine, and birch than for a-pinene as single compound. We therefore conclude that the threshold for SOA formation from real plant mixtures may be much lower than the threshold obtained from laboratory experiments that were focussed on single VOCs. SOA formation from stress induced VOCs will be compared to non stress induced emissions. Possible feedbacks of climate change to VOC emissions and aerosol formation will be discussed based on our experimental observations.

Kiendler-Scharr, A.; Mentel, T. F.; Kleist, E.; Hohaus, T.; Mensah, A.; Spindler, C.; Tillmann, R.; Uerlings, R.; Dal Maso, M.; Rudich, Y.; Juergen, W.

2008-12-01

31

CONTROL TECHNOLOGIES FOR FUGITIVE VOC EMISSIONS FROM CHEMICAL PROCESSES  

EPA Science Inventory

This handbook contains information concerning volatile organic compound (VOC) emissions from the synthetic organic chemicals manufacturing industry (SOCMI), petroleum refineries, on-shore natural gas processing plants, polymer manufacturing plants, benzene from particular equipme...

32

Methods for measuring VOC emission from interior paints  

Microsoft Academic Search

Summaries  Chamber tests were undertaken to rank twelve paints comprising alkyd gloss, non-drip, high solids undercoat and several emulsion\\u000a and other water-based materials, on the basis of their total VOC emission rates and the chemical composition of the VOC mixture.\\u000a Paint film thickness, airflow rate and the type of substrate were found to affect the measurement of the emission rate. A

CWF Yu; Crump

2000-01-01

33

Speciated VOC to CO Ratios in Global Megacities: towards a model emission inventory parameterization  

NASA Astrophysics Data System (ADS)

As of 2007 over half of the world's population live in urban areas. Urban air pollution is an issue in most megacities, which are loosely defined as urban areas with populations of 10 million or more. A recent modelling study showed that while megacities in Asia are concentrated into approximately 2% of the land area, they emit 10-15% of total anthropogenic emissions in Asia and contain 30% of the Asian population, therefore exerting a disproportionate impact on human health. The largest source of emissions in most megacities and urban conglomerations is vehicular-related emissions. Anthropogenic volatile organic compounds (VOCs), carbon monoxide (CO), and nitrogen oxides (NOx) are important precursor compounds to ozone and secondary organic aerosol formation and are emitted largely from vehicles in urban areas. Elevated levels of ozone, which are harmful to human health, have been observed in many urban areas and megacities. Quantifying ozone precursors and being able to model them accurately to derive the impact of emissions changes is important for policy-makers and the improvement of air quality. Certain VOCs are very reactive in the atmosphere (e.g., xylenes and benzene compounds) and therefore have very high potential for ozone and SOA formation; accurate modelling of the individual VOCs will lead to better predictions of SOA formation and ozone levels. Using speciated volatile organic compound (VOC) and carbon monoxide (CO) measurements from the Marylebone Road, a kerbside site in central London from 1998 to 2009 a number of statistical analyses have been undertaken to investigate the long-term trends in the data and the VOC to CO ratios. Long-term trends show decreases by a factor of four for the VOCs and a factor of three for the CO over the measurement period. Although significant decreases in concentration were observed the fractional contribution of the individual VOCs to the total remained similar. Over the same period VOC to CO ratios for London remained steady an indication that emissions reduction measures affected all the measured compounds equally. A comparison of VOC to CO ratios was undertaken for London and other global megacities. Remarkably similar ratios were found for all cities in developed countries. Since megacity emissions are typically dominated by vehicular emissions, the dominant source of VOCs and CO in most urban areas, it is suggested that given the similarity of VOC to CO ratios in these cities, the ratios could be used to constrain and thereby improve VOC representation in regional/global models for urban areas.

von Schneidemesser, Erika; Monks, Paul

2010-05-01

34

Evaluation of accuracy in measurements of VOC emissions with dynamic chamber system  

NASA Astrophysics Data System (ADS)

We determined the accuracy of the dynamic chamber system for measuring VOC emissions of trees and soil in the field at SMEAR II station, Hyytiälä, Southern Finland. The study was based on creating a known source of different VOCs inside the chamber and measuring the concentration dynamics in the chamber by a proton transfer reaction mass spectrometer (PTR-MS) connected to the chamber. The chamber system underestimated the artificially generated VOC emission rates at varying degree. In isoprene, monoterpene and many oxygenated VOCs the underestimation was 5-30% but in some compounds with protonated mass >100 amu the signal was almost completely lost. The underestimation mainly originated in the chamber but the length of the sample tubing also affected the observed magnitude of the standard gas emission. The systematic error was higher at high relative humidity than in drier conditions, which suggests that the thickness of the water film adsorbed on the chamber inner surfaces contributes to the VOC loss rate in the chamber. Increasing the length of the chamber closure time slightly reduced the systematic underestimation of emission in most of the studied compounds although the underestimation persisted for at least 10 min. A dynamic chamber setup enables measurement of VOC emissions with good accuracy and precision while minimising the disturbance of the chamber to the object being measured.

Kolari, Pasi; Bäck, Jaana; Taipale, Risto; Ruuskanen, Taina M.; Kajos, Maija K.; Rinne, Janne; Kulmala, Markku; Hari, Pertti

2012-12-01

35

Exploring VOC control options  

Microsoft Academic Search

Since the refineries and chemical plants handle large quantities of volatile organic compounds (VOCs), some emissions of these compounds are likely during normal operations. Based on studies in the US, the largest source of VOCs is from fugitive emissions from piping and other fluid handling components. VOCs also come from storage tanks, loading operations, and wastewater treatment. The most applicable

Siegell

1996-01-01

36

Detection and quantification of methane and VOC emissions from oil and gas production operations using remote measurements, Interim report  

EPA Science Inventory

Improved understanding of air pollutant emissions from oil and gas production operations is needed. With a steadily increasing number of production sources, the impact of emitted volatile organic compounds (VOCs) on regional ozone is potentially significant. As the separation dis...

37

Emission inventory of anthropogenic air pollutants and VOC species in the Yangtze River Delta region, China  

NASA Astrophysics Data System (ADS)

The purpose of this study is to develop an emission inventory for major anthropogenic air pollutants and VOC species in the Yangtze River Delta (YRD) region for the year 2007. A "bottom-up" methodology was adopted to compile the inventory based on major emission sources in the sixteen cities of this region. Results show that the emissions of SO2, NOx, CO, PM10, PM2.5, VOCs, and NH3 in the YRD region for the year 2007 are 2392 kt, 2293 kt, 6697 kt, 3116 kt, 1511 kt, 2767 kt, and 459 kt, respectively. Ethylene, mp-xylene, o-xylene, toluene, 1,2,4-trimethylbenzene, 2,4-dimethylpentane, ethyl benzene, propylene, 1-pentene, and isoprene are the key species contributing 77 % to the total ozone formation potential (OFP). The spatial distribution of the emissions shows the emissions and OFPs are mainly concentrated in the urban and industrial areas along the Yangtze River and around Hangzhou Bay. The industrial sources, including power plants other fuel combustion facilities, and non-combustion processes contribute about 97 %, 86 %, 89 %, 91 %, and 69 % of the total SO2, NOx, PM10, PM2.5, and VOC emissions. Vehicles take up 12.3 % and 12.4 % of the NOx and VOC emissions, respectively. Regarding OFPs, the chemical industry, domestic use of paint & printing, and gasoline vehicles contribute 38 %, 24 %, and 12 % to the ozone formation in the YRD region.

Huang, C.; Chen, C. H.; Li, L.; Cheng, Z.; Wang, H. L.; Huang, H. Y.; Streets, D. G.; Wang, Y. J.; Zhang, G. F.; Chen, Y. R.

2011-05-01

38

Control of VOC emissions from nonferrous-metal rolling processes  

SciTech Connect

The document was developed in response to increasing inquiries into the environmental impacts of nonferrous metal rolling processes that use oil as a lubricant and coolant in rolling operations. VOC emissions result from evaporative fugitive losses caused by heat generated in the rolling processes. The focus of the document is VOC emission control techniques used by copper and aluminum rolling mills. A control cost analysis is also provided for each of the control techniques addressed. The control techniques are: carbon adsorption, absorption, incineration, and lubricant substitution.

Not Available

1992-06-01

39

Location and Characterization of VOC Emissions at a Petrochemical Plant in Taiwan  

Microsoft Academic Search

This research aimed to locate and characterize emission sources for airborne volatile organic compounds (VOCs) inside a petrochemical plant in Chiayi, Taiwan. Air was sampled with canisters at 20 sites inside this plant, twice per quarter, and analyzed by gas chromatography\\/mass spectrometry following the TO–14 method. Data were interpreted by means of a database and contour maps. Alkanes were most

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

2006-01-01

40

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...

41

Source profiles of volatile organic compounds (VOCs) measured in China: Part I  

NASA Astrophysics Data System (ADS)

The profiles of major volatile organic compound (VOC) sources in China, including vehicle exhaust, gasoline vapor, paint, asphalt, industrial and residential coal burning, biomass burning, and the petrochemical industry, were experimentally determined. Source samples were taken using a dilution chamber for mobile and stationary sources, biomass burning in an actual Chinese farmer's house, and ambient air in a petrochemical industrial area. The concentrations of 92 VOC species were quantified using canister sampling and a gas chromatography-flame ionization detection/mass spectrometry system, and VOC source profiles were developed for source apportionment of VOCs in the Pearl River Delta region. Based on the measurement of source profiles, possible tracers for various emission sources were identified; e.g., 2-methylpentane and 1,3-butadiene could be used as tracers for vehicle exhaust; the characteristic compounds of architectural coating were aromatics such as toluene and m, p-xylene; the light hydrocarbons, namely n-butane, trans-2-butene, and n-pentane, dominated the composition of gasoline vapor; and n-nonane, n-decane, and n-undecane were found to be typical of diesel vapor and asphalt application processes. As different emission sources are characterized by overlapping VOC species, the ratio of possible VOC tracers could be used to assess the contribution of various sources. The ratios between n-butane and isobutane, 1,3-butadiene and isoprene, and the ratios of aromatics (e.g., toluene to benzene and ethylbenzene to m, p-xylene) in the measured sources were compared.

Liu, Ying; Shao, Min; Fu, Linlin; Lu, Sihua; Zeng, Limin; Tang, Dagang

42

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

EPA Science Inventory

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

43

Light dependency of VOC emissions from selected Mediterranean plant species  

NASA Astrophysics Data System (ADS)

The light, temperature and stomatal conductance dependencies of volatile organic compound (VOC) emissions from ten plant species commonly found in the Mediterranean region were studied using a fully controlled leaf cuvette in the laboratory. At standard conditions of temperature and light (30°C and 1000 ?mol m -2 s -1 PAR), low emitting species ( Arbutus unedo, Pinus halepensis, Cistus incanus, Cistus salvifolius, Rosmarinus officinalis and Thymus vulgaris) emitted between 0.1 and 5.0 ?g (C) (total VOCs) g -1 dw h -1, a medium emitter ( Pinus pinea) emitted between 5 and 10 ?g (C) g -1 dw h -1 and high emitters ( Cistus monspeliensis, Lavendula stoechas and Quercus sp.) emitted more than 10 ?g (C) g -1 dw h -1. VOC emissions from all of the plant species investigated showed some degree of light dependency, which was distinguishable from temperature dependency. Emissions of all compounds from Quercus sp. were light dependent. Ocimene was one of several monoterpene compounds emitted by P. pinea and was strongly correlated to light. Only a fraction of monoterpene emissions from C. incanus exhibited apparent weak light dependency but emissions from this plant species were strongly correlated to temperature. Data presented here are consistent with past studies, which show that emissions are independent of stomatal conductance. These results may allow more accurate predictions of monoterpene emission fluxes from the Mediterranean region to be made.

Owen, S. M.; Harley, P.; Guenther, A.; Hewitt, C. N.

44

VOC Emissions from the Potential Biofuel Crop, Switchgrass  

NASA Astrophysics Data System (ADS)

Volatile organic compound (VOC) emission rates during the growth and simulated harvest phases were determined for three different cultivars of switchgrass (Panicum virgatum) using laboratory chamber measurements. Switchgrass is a candidate for use in second-generation (cellulosic) ethanol production and the acerage dedicated to its growth in the USA has already increased during the past decade. We estimate that the yearly emissions from switchgrass plantations, including both the growth and harvest phases, will be on the order of 3 kg C ha-1 methanol, 1 kg C ha-1 acetaldehyde, 1 kg C ha-1 acetone, 0.9 kg C ha-1 monoterpenes, 0.5 kg C ha-1 isoprene + 1-penten-3-ol, 0.2 kg C ha-1 hexenals, and 0.1 kg C ha-1 hexenols. These emission rates are lower than those expected from Eucalyptus or Poplar plantations, which are other potential biofuel crops and have significantly higher VOC emissions.

Graus, M.; Eller, A. S.; Fall, R.; Gilman, J. B.; Kuster, W. C.; de Gouw, J. A.; Qian, Y.; Sekimoto, K.; Monson, R. K.; Warneke, C.

2010-12-01

45

SOURCES OF AIR POLLUTANTS INDOORS: VOC AND FINE PARTICULATE SPECIES  

EPA Science Inventory

The average concentrations of a large number of fine particle aerosol and VOC species measured in ten Boise ID residences in wintertime have been apportioned according to their contributions from all inside sources and all outside sources, regarded as two composite source categor...

46

On the determination of VOCs emission factors in dry building materials  

NASA Astrophysics Data System (ADS)

A comprehensive modelling study was performed to determine volatile organic compounds (VOCs) emission factors in dry building materials. In order to examine the emission characteristics of VOCs in dry building materials (carpet), an experiment was conducted, and a mathematical methodology was considered together with a numerical work for a validation. Here, a new representative airside VOCs concentration was considered in a mode different from that of previous studies, which allows us to evaluate VOCs emission factors more accurately.

Shin, Dong Min; Kim, Chang Nyung; Park, Chang-Ho; Kim, Dong-Sool; Nam, Youngsuk

2013-11-01

47

On the determination of VOCs emission factors in dry building materials  

NASA Astrophysics Data System (ADS)

A comprehensive modelling study was performed to determine volatile organic compounds (VOCs) emission factors in dry building materials. In order to examine the emission characteristics of VOCs in dry building materials (carpet), an experiment was conducted, and a mathematical methodology was considered together with a numerical work for a validation. Here, a new representative airside VOCs concentration was considered in a mode different from that of previous studies, which allows us to evaluate VOCs emission factors more accurately.

Shin, Dong Min; Kim, Chang Nyung; Park, Chang-Ho; Kim, Dong-Sool; Nam, Youngsuk

2013-07-01

48

Epirrita autumnata induced VOC emission of silver birch differ from emission induced by leaf fungal pathogen  

Microsoft Academic Search

The production of volatile organic compounds (VOCs) through the activation of different signal-transduction pathways may be induced in various biotic and abiotic stress situations having importance e. g. in insect and disease resistance. We compared the emission of VOCs emitted from silver birch Betula pendula Roth (clones 4 and 80) twigs damaged either by larvae of Epirrita autumnata, or infected

Terhi Vuorinen; Anne-Marja Nerg; L. Syrjala; Petri Peltonen; Jarmo K. Holopainen

2007-01-01

49

Emissions of VOCs at urban petrol retail distribution centres in India (Delhi and Mumbai).  

PubMed

Air pollution has assumed gigantic proportion killing almost half a million Asians every year. Urban pollution mainly comprises of emissions from buses, trucks, motorcycle other forms of motorized transport and its supporting activities. As Asia's cities continue to expand the number of vehicles have risen resulting in greater pollution. Fugitive emissions from retail distribution center in urban area constitute a major source. Petrol vapours escape during refueling adding pollutants like benzene, toluene, ethylbenzene and xylene to ambient air. This paper discusses a study on fugitive emissions of Volatile Organic Compounds (VOC) at some refueling station in two metropolitan cities of India, i.e., Mumbai and Delhi. Concentration of VOCs in ambient air at petrol retail distribution center is estimated by using TO-17 method. Concentration of benzene in ambient air in Delhi clearly shows the effect of intervention in use of petroleum and diesel fuel and shift to CNG. Chemical Mass Balance (CMB) model is used to estimate source contributions. At Delhi besides diesel combustion engines, refueling emissions are also major sources. At Mumbai evaporative emissions are found to contribute maximum to Total VOC (TVOC) concentration in ambient air. PMID:16240200

Srivastava, Anjali; Joseph, A E; More, Ajit; Patil, Sunil

2005-10-01

50

VOC Source Apportionment in Houston, TX, during TexAQS II  

NASA Astrophysics Data System (ADS)

During the TexAQS II campaign in summer 2006 (08/07/06 - 09/30/06) continuous online measurements of C2 - C10 Volatile Organic Compounds (VOCs) were performed with an online gas chromatograph (GC/FID) at the Moody Tower supersite on the University of Houston campus. In addition, VOC data were obtained by the TCEQ and Enhanced Industry Sponsored Monitoring auto-GC networks near the Houston Ship Channel area. A comparative analysis of source contributions at the Moody Tower receptor site and at one Ship Channel site representing major industrial emissions, with the goal of assessing the impact of these emissions onto the 10 km distant receptor site, were performed. The analysis of VOC results indicates complex mixtures from traffic, industrial, and biogenic sources. In order to identify and apportion these source contributions of the VOCs to the receptor site during the campaign, multivariate receptor models were applied. The results of a principal component analysis (PCA) and a positive matrix factorization (PMF) reveal a set of factors and source profiles that are associated with several anthropogenic (industrial, traffic) as well as biogenic sources.

Leuchner, M.; Rappenglueck, B.

2007-12-01

51

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

Microsoft Academic Search

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

Chia-Hsien Yen; Jao-Jia Horng

2009-01-01

52

Put the lid on VOC emissions from maintenance coatings  

SciTech Connect

After the coating film is applied to the substrate, the solvents evaporate and generally become an environmental liability. Solvents used by the coatings industry have been a major environmental issue for many years. Over the years, regulations have been aimed at reducing or eliminating photochemically reactive solvents--those that react in the atmosphere with nitrogen oxides in the atmosphere with nitrogen oxides in the presence of sunlight and heat to form ozones. Many of the solvents used in the coatings industry are, in fact, photochemically reactive. The rules regulating the maintenance coatings industry can generally be divided into three categories: 1. Rules aimed at restricting the VOCs in steel fabricating shops and paint shops. 2. Rules aimed at regulating the emission of VOCs from coatings applied in the field such as on bridges or industrial structures. 3. Rules aimed at the shipbuilding industry where coatings are applied to marine vessels. The paper discusses reducing VOCs, penetrating sealers, mastics, tank linings, inorganic zincs, topcoats--waterborne acrylics, zero-VOC urethane/water systems, and solventless topcoats.

Morgan, R.E. [Valspar Corp., Baltimore, MD (United States). Protective Coatings Div.

1996-11-01

53

Non-Destructive Evaluation of Historical Paper Based on pH Estimation from VOC Emissions  

Microsoft Academic Search

Volatile organic compounds (VOCs) emitted from materials during degradation can be a valuable source of information. In this wo rk, the emissions of furfural and acetic acid from cellulose were studied using solid-phase micro-extraction (SPME) in combination with gas chromatography-mass spectrometry. Two sampling techniques were employed: static headspace sampling using SPME for 1 h at 40 oC after 18-h sample

Irena Kralj Cigi ?; Jana Kolar; Gerrit de Bruin; Boris Pihlar

2007-01-01

54

Sources and reactivity of NMHCs and VOCs in the atmosphere: a review.  

PubMed

Nonmethane hydrocarbons (NMHCs) and volatile organic compounds (VOCs) are important species present in the environment, which results in alteration of the chemistry of atmosphere. On the global scale natural emissions of NMHCs and VOCs exceed anthropogenic emissions, although anthropogenic sources usually dominate within urban areas. Among the natural sources, vegetation is the dominant source. Oceanic and microbial production of these species is minimal as compared to other sources of input. Isoprene and terpenes are main species of NMHCs which are emitted from plants as a protective mechanism against temperature stress tolerance and protection from ravages of insects and pests. The major anthropogenic sources for NMHCs emissions are biomass burning and transportation. NMHCs play a significant role in ozone (O(3)) production in the presence of adequate concentration of oxides of nitrogen in the atmosphere. The production of O(3) is based on Maximum Incremental Reactivity (MIR) of NMHCS and VOCs. The compound's MIR multiplied by molecular weight gives Relative Ozone Productivity (ROPi). To check the reliability of current methods of measuring the NMHCs the Nonmethane Hydrocarbon Inter-comparison Experiment (NMHICE) had been designed. The sample of known composition and unknown concentration of different hydrocarbons was supplied to different laboratories worldwide and less than 50% laboratories correctly separated the unknown mixture. Atmospheric scientists throughout the world are evaluating current analytical methods being employed and are trying to correct the problems to ensure quality control in hydrocarbon analysis. PMID:19136203

Kansal, Ankur

2008-11-24

55

VOC Emission Characteristics of Petrochemical Wastewater Treatment Facilities in Southern Taiwan  

Microsoft Academic Search

The wastewater treatment plants (WWTPs) of three representative petrochemical plants in southern Taiwan were sampled to investigate their VOC emission characteristics. Generally, emissions decline along the process flow, while the VOC concentration accumulates to as much as around 2400 mg\\/m (as total hydrocarbons) at several closed vessel vents during the primary treatment. VOC emission rates (g\\/s) and fluxes (g\\/m hr) exhibit a

Wen-Hsi Cheng; Ming-Shean Chou

2003-01-01

56

Determination of radon exhalation from construction materials using VOC emission test chambers.  

PubMed

The inhalation of (222) Rn (radon) decay products is one of the most important reasons for lung cancer after smoking. Stony building materials are an important source of indoor radon. This article describes the determination of the exhalation rate of stony construction materials by the use of commercially available measuring devices in combination with VOC emission test chambers. Five materials - two types of clay brick, clinker brick, light-weight concrete brick, and honeycomb brick - generally used for wall constructions were used for the experiments. Their contribution to real room concentrations was estimated by applying room model parameters given in ISO 16000-9, RP 112, and AgBB. This knowledge can be relevant, if for instance indoor radon concentration is limited by law. The test set-up used here is well suited for application in test laboratories dealing with VOC emission testing. PMID:23374080

Richter, M; Jann, O; Kemski, J; Schneider, U; Krocker, C; Hoffmann, B

2013-03-21

57

Investigation Methods to Distinguish Between Vapor Intrusion and Indoor Sources of VOCS.  

National Technical Information Service (NTIS)

Indoor sources of volatile organic chemicals (VOCs) are ubiquitous, resulting in detectable concentrations in indoor air, often at concentrations above regulatory screening levels. At VOC contaminated sites with potential vapor intrusion concerns, the pre...

K. Gorder L. Beckley P. Philp T. Kuder T. McHugh

2010-01-01

58

Test methods for determining short and long term VOC emissions from latex paint  

SciTech Connect

The paper discusses an evaluation of latex paint (interior, water based) as a source of indoor pollution. A major objective of the research is the development of methods for predicting emissions of volatile organic compounds (VOCs) over time. Test specimens of painted gypsumboard are placed in dynamic flow-through test chambers. Samples of the outlet air are collected on Tenax sorbents and thermally desorbed for analysis by gas chromatography/flame ionization detection. These tests produce short- and long-term data for latex paint emissions of Texanol, 2-2(-butoxyethoxy)-ethanol, and glycols. Evaluation of the data shows that most of the Texanol emissions occur within the first few days, and emissions of the glycols occur over several months. This behavior may be described by an evaporative mass transfer process that dominates the short-term emissions, while long-term emissions are limited by diffusion processes within the dry paint-gypsumboard.

Krebs, K.; Lao, H.C.; Fortmann, R.; Tichenor, B.

1998-09-01

59

Fine-scale Source Distribution of Biogenic VOCs Measured by Proton-Transfer-Reaction Mass Spectrometry.  

NASA Astrophysics Data System (ADS)

We have recently deployed Proton-Transfer-Reaction Mass Spectrometry for measuring reactive biogenic trace gases at a loblolly pine plantation in North Carolina (Duke Forest) as well as a primary tropical rainforest in Costa Rica. An automated moveable inlet system allowed observations of the finescale source structure of various biogenics, such as isoprene, MVK+MAC, acetaldehyde, acetone, methanol and monoterpenes within the canopy using an inverse lagrangian dispersion model. The distribution of oxygenated compounds in general shows a complex behavior of emission and deposition. Together with eddy covariance measurements at the top of the canopy, which we compare with enclosure measurements, we are able to quantify finescale exchange processes of VOCs within the canopy. Our measurements demonstrate that the treatment of emission and deposition currently used for modeling oxygenated biogenic VOCs can only be seen as a first order approximation.

Karl, T.; Potosnak, M.; Guenther, A.; Nemitz, E.; Turnipseed, A.; Baker, B.; Geron, C.

2003-12-01

60

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

61

EVALUATION OF POTENTIAL VOC SCREENING INSTRUMENTS  

EPA Science Inventory

The report describes the evaluation of potential fugitive source emission screening instruments for analysis of volatile organic compounds (VOCs). An initial review of available portable VOC detection instruments indicated that detectors operating on several principles (i.e., fla...

62

Development of secondary electron emission gun for VOC's treatment  

Microsoft Academic Search

Summary form only given. Volatile organic compounds (VOCs) in the air cause photochemical oxidant formation and stratospheric ozone depletion. Non-thermal plasma technologies using electrical discharges or electron beam irradiation offer an energy- and cost- efficient approach to the decomposition of VOCs. In the present work, VOC removal using electron beam is studied. The electron beam was generated by a secondary

D. Kato; M. Shimizu; M. Watanabe; A. Okino; E. Hotta

2009-01-01

63

VOC Source - Receptor Relationships in Houston during TexAQS-II  

NASA Astrophysics Data System (ADS)

During the TexAQS-II field campaign in August and September 2006, C2 - C10 volatile organic compounds (VOC) were measured continuously and online at the urban Moody Tower (MT) site. This data set was compared to corresponding VOC data sets obtained at six sites located in the highly industrialized Houston Ship Channel area (HSC). Receptor modeling was performed by positive matrix factorization (PMF) at all sites. Conditional probability functions were used to determine the origin of the polluted air masses in the Houston area. A subdivision into daytime and nighttime was carried out to discriminate photochemical influences. Eight main source categories of industrial, mobile, and biogenic emissions were identified at the urban receptor site, seven and six, respectively, at the different HSC sites. Amongst these categories, natural gas / crude oil, LPG, and vehicular exhaust contributed most to the total measured VOC mass, followed by fuel evaporation, aromatics, petrochemical sources from ethylene and propylene, and biogenic sources. Based on PMF analyses of different wind sectors, the total VOC mass was estimated to be twofold at MT with wind directions from HSC compared to air from a typical urban sector, for petrochemical compounds more than threefold. Despite the strong impact of air masses influenced by industrial sources at HSC, still a significant fraction of the total mass contributions at MT can be apportioned to other sources, mainly motor vehicles and aromatic solvents. The investigation of diurnal variation in combination with wind directional frequencies revealed the greatest HSC impact at the urban site during the morning, and the least during the evening.

Leuchner, M.; Rappenglück, B.

2009-04-01

64

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

PubMed

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

Padhy, P K; Varshney, C K

2005-06-01

65

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

NASA Astrophysics Data System (ADS)

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

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

66

Ambient VOC Concentration and Emission Measurements during the MCMA 2002 and 2003 Field Campaigns  

Microsoft Academic Search

As part of the MCMA 2002 and 2003 field campaigns in Mexico City, ambient VOC samples were collected from airshed boundary sites, central urban core sites and downwind urban receptor sites. Samples were also obtained during mobile vehicle chase operations designed to obtain data on direct vehicle emissions. During MCMA 2003, additional VOC data were collected including open, long path

B. K. Lamb; E. Velasco; E. Allwine; S. Pressley; H. Westberg; B. Knighton; T. Rogers; E. Grimsrud; T. Jobson; M. Alexander; P. Prazeller; R. Volkamer; B. de Foy; L. Molina; M. Molina; M. Grutter; E. Bueno; S. Blanco; H. Wohrnschimmel; B. Cardenas; J. L. Arriaga; M. T. Limon; S. Escalona; G. S. Iglesias; P. Doskey; J. Gaffney

2004-01-01

67

Modeling VOC Emissions and Air Concentrations from the Exxon Valdez Oil Spill  

Microsoft Academic Search

During the two-week period following the Exxon Valdez oil spill in March 1989 in Prince William Sound, Alaska, toxic volatile organic compounds (VOCs) evaporated from the surface of the oil spill and were transported and dispersed throughout the region. To estimate the air concentrations of these VOCs, emissions and dispersion modeling was conducted for each hour during the first two

Steven R. Hanna; Peter J. Drivas

1993-01-01

68

Analysis and comparison of trends in concentrations and emissions of VOC and CO and VOC:CO ratios in urban European cities  

NASA Astrophysics Data System (ADS)

Since 2007, more than half of the world's population live in urban areas. Megacities, urban agglomerations with more than 10 million inhabitants, are rapidly increasing in number: in 1950 there were only two, New York and Tokyo with ~12 million, while by 2005 there were already 20, with Tokyo ranging the 35 millions. The urban atmospheres of these megacities are dominated by pollutants associated with vehicular emissions, as well as the formation of secondary pollutants responsible for photochemical smog. A comparative assessment of emissions and concentrations of volatile organic compounds (VOC) and carbon monoxide (CO) ratios in London (L) and Paris (P) is hereby presented. The work is based on three recent studies by Baker et al. (2008), Parrish et al. (2009) and von Schneidemesser et al. (in press) where concentrations of these compounds were analyzed for 28 US cities in the former and some global megacities in the second and third studies. Considering the fact that VOC provide information on the main emissions sources of cities, these studies found that even though concentrations of VOC varied greatly among cities, the ratio with the combustion tracer CO remained rather constant and was very useful for city comparison, as well as a good indicator of traffic emissions. VOC patterns in ambient air concentrations were observed to be similar in most cities, being able to consider that deviations from those patterns could be the result of measurement problems. Nevertheless, the representation of these emissions in global inventories has large uncertainties. The goal of our study is to compare and contrast emission inventory estimates with measured ambient concentrations of non-methane hydrocarbons (NMHC) and CO, as well as NMHC:CO ratios. Within the European CityZen project we have built an updated global emissions inventory with the best available datasets of anthropogenic, biomass burning and natural sources. As part of this research we will follow the same approach to compare emissions ratios between NMHC and CO for the megacities region of Paris and London and to compare these trends with measured ambient concentrations from three monitoring sites: Eltham (L) suburban station, Marylebone Road (L) kerbside station and Les Halles (P) urban station for the period 1997-2006.

D'Angiola, A.; von Schneidemesser, E.; Granier, C.; Law, K.; Monks, P. S.

2010-12-01

69

Exploring VOC control options  

SciTech Connect

Since the refineries and chemical plants handle large quantities of volatile organic compounds (VOCs), some emissions of these compounds are likely during normal operations. Based on studies in the US, the largest source of VOCs is from fugitive emissions from piping and other fluid handling components. VOCs also come from storage tanks, loading operations, and wastewater treatment. The most applicable and economic control system will depend on the specific emission source, the level of controls already in place, and the target emission level. Controls range from increased monitoring and maintenance frequency for valve leaks, to replacing rim seals on floating roof tanks, to installing a complete vapor control system at a loading facility. The costs can vary widely. A table lists options for controlling VOC emissions. The paper describes a few of these in more detail.

Siegell, J.H. [Exxon Research and Engineering Co., Florham Park, NJ (United States)

1996-06-01

70

Measurements of VOCs by proton transfer reaction mass spectrometry at a rural Ontario site: Sources and correlation to aerosol composition  

NASA Astrophysics Data System (ADS)

Proton transfer reaction mass spectrometry (PTR-MS) volatile organic compound (VOC) measurements were made at the Centre for Atmospheric Research Experiments at Egbert, Ontario, over a five week period in May to June 2007. VOCs were also analyzed by gas chromatography and with a fluorescence detector sensitive to formaldehyde. This is a well positioned site for contrasting biogenic versus anthropogenic sources. In particular, with southerly flow from Southern Ontario, the VOC signal was observed to have strong anthropogenic influence, as seen through high levels of aromatics, acetylene and NOx. With flow from the northwest, the VOCs had substantial biogenic character, with elevated mixing ratios of monoterpenes, isoprene, and possibly 2-methyl-3-buten-2-ol (MBO) with increasing temperatures. Positive matrix factorization (PMF) was applied to the PTR-MS data set yielding two noninstrumental factors, one related to primary anthropogenic emissions and one arising from secondary atmospheric oxidation. There is a tight correspondence between the composition of the submicron organic aerosol and the VOCs. In particular, (1) organic aerosol loadings highly correlate with long-lived VOC tracers such as acetone, (2) the degree of oxygenation of the organic aerosol scaled with the photochemical age of the air, as determined through the toluene-to-benzene ratio, and (3) there is a tight correlation between PMF factors from the AMS and PTR-MS data sets, with the HOA AMS factor scaling with the anthropogenic emissions PTR-MS factor and the OOA AMS factor matched to the photochemical oxidation PTR-MS factor. Finally, the PTR-MS PMF factors were used for VOC source apportionment.

Vlasenko, A.; Slowik, J. G.; Bottenheim, J. W.; Brickell, P. C.; Chang, R. Y.-W.; MacDonald, A. M.; Shantz, N. C.; Sjostedt, S. J.; Wiebe, H. A.; Leaitch, W. R.; Abbatt, J. P. D.

2009-11-01

71

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

National Technical Information Service (NTIS)

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

B. E. Rittmann E. Namkung

1986-01-01

72

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

NASA Astrophysics Data System (ADS)

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

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

73

Emission of short-chained oxygenated voc from the leaves of mature central european tree species  

NASA Astrophysics Data System (ADS)

The photolytic and oxidative destruction of volatile organic compounds (VOC) in the atmosphere results in a net production of tropospheric ozone. Oxygenated VOC (OVOC) are either directly emitted into the atmosphere or are produced there by oxidation of other hydrocarbons. Besides anthropogenic sources, the emission of OVOC by vegetation, particularly by forest ecosystems, is considered a major source of atmospheric OVOC. Exact numbers on emission rates from important tree species as well as production mechanisms that lead to the release of OVOC from leaves are, however, not known. In the present study, field campaigns were conducted in typical forest ecosystems in Germany in order to elucidate the spectrum and the amount of OVOC emitted by Central European tree species. Exchange data obtained were compared with physiological and meteorological parameters to obtain information on the factors controlling trace gas exchange. The field campaigns were accompanied by studies under controlled conditions in the laboratory. The poster presents data on carbonyl exchange between Picea abies, Fagus sylvatica, Carpinus betulus and other species and the atmosphere and indicates plant internal and meteorological factors (temperature, ambient OVOC concentrations, light intensities, water supply, etc.) that may determine exchange rates.

Kreuzwieser, J.; Cojocariu, C.; Rennenberg, H.

2003-04-01

74

Reducing VOC Press Emissions from Oriented Strand Board (OSB) Manufacturing. Final Project Report.  

National Technical Information Service (NTIS)

Current regulations require industry to meet air emission standards with regard to particulates, volatile organic compounds (VOCs), hazardous air pollutants (HAPs) and other gases. One of many industries that will be affected by the new regulations is the...

G. D. McGinnis

2001-01-01

75

VOC emissions, evolutions and contributions to SOA formation at a receptor site in eastern China  

NASA Astrophysics Data System (ADS)

Volatile organic compounds (VOCs) were measured by two online instruments (GC-FID/MS and PTR-MS) at a receptor site on Changdao Island (37.99° N, 120.70° E) in eastern China. Reaction with OH radical dominated chemical losses of most VOC species during the Changdao campaign. A photochemical-age-based parameterization method is used to calculate VOC emission ratios and to quantify the evolution of ambient VOCs. The calculated emission ratios of most hydrocarbons agree well with those obtained from emission inventory data, but determined emission ratios of oxygenated VOCs (OVOCs) are significantly higher than those from emission inventory data. The photochemical-age-based parameterization method is also used to investigate primary emissions and secondary formation of organic aerosol. The primary emission ratio of organic aerosol (OA) to CO is determined to be 14.9 ?g m-3 ppm-1, and secondary organic aeorosols (SOA) are produced at an enhancement ratio of 18.8 ?g m-3 ppm-1 to CO after 50 h of photochemical processing in the atmosphere. SOA formation is significantly higher than the level determined from VOC oxidation under both high-NOx (2.0 ?g m-3 ppm-1 CO) and low-NOx conditions (6.5 ?g m-3 ppm-1 CO). Polycyclic aromatic hydrocarbons (PAHs) and higher alkanes (> C10) account for as high as 17.4% of SOA formation, which suggests semi-volatile organic compounds (SVOCs) may be a large contributor to SOA formation during the Changdao campaign. The SOA formation potential of primary VOC emissions determined from field campaigns in Beijing and Pearl River Delta (PRD) is lower than the measured SOA levels reported in the two regions, indicating SOA formation is also beyond explainable by VOC oxidation in the two city clusters.

Yuan, B.; Hu, W. W.; Shao, M.; Wang, M.; Chen, W. T.; Lu, S. H.; Zeng, L. M.; Hu, M.

2013-09-01

76

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

SciTech Connect

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

Center for Human Reliability Studies

2006-06-01

77

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

78

The study of emission inventory on anthropogenic air pollutants and VOC species in the Yangtze River Delta region, China  

NASA Astrophysics Data System (ADS)

The purpose of this study is to develop an emission inventory for major anthropogenic air pollutants and VOC species in the Yangtze River Delta (YRD) region for the year 2007. A "bottom-up" methodology was adopted to compile the inventory based on major emission sources in the sixteen cities of this region. Results show that the emissions of SO2, NOx, CO, PM10, PM2.5, VOCs, and NH3 in the YRD region for the year 2007 are 2391.8 kt, 2292.9 kt, 6697.1 kt, 3115.7 kt, 1510.8 kt, 2767.4 kt, and 458.9 kt, respectively. Ethylene, mp-xylene, o-xylene, toluene, and 1,2,4-trimethylbenzene, 2,4-dimethylpentane, ethyl benzene, propylene, 1-pentene, and isoprene are the key species contributing 77% to the total OFPs. The spatial distribution of the emissions shows the emissions and OFPs are mainly concentrated in the urban and industrial areas along the Yangtze River and around the Hangzhou Bay. The industrial sources including power plant, other fuel combustion facilities, and non-combustion processes contribute about 97%, 86%, 89%, 91%, and 69% of the total SO2, NOx, PM10, PM2.5, and VOC emissions. Vehicles take up 12.3% and 12.4% of the NOx and VOC emissions, respectively. Regarding OFPs, chemical industry, domestic use of paint and printing, and gasoline vehicle contribute 38.2%, 23.9%, and 11.6% to the ozone formation in the YRD region.

Huang, C.; Chen, C. H.; Li, L.; Cheng, Z.; Wang, H. L.; Huang, H. Y.; Streets, D. G.; Wang, Y. J.

2011-01-01

79

Off-gas recycle for VOC emission control: Conceptual model  

Microsoft Academic Search

Capture and recycle of off-gas from a complete-mix activated-sludge reactor was evaluated as an alternative VOC-control strategy to reduce the volume and cost of off-gas treatment. A mathematical model was developed to predict the fraction of individual influent VOC compounds that are biodegraded, stripped, and discharged in the liquid and gaseous effluents of an activated-sludge reactor with off-gas recycle. The

Y. Argaman; J. L. Musterman

2009-01-01

80

Temporal and spatial variation of forest VOC emissions in Germany in the decade 1994-2003  

NASA Astrophysics Data System (ADS)

Biogenic emissions are strongly governed by temperature and light. One key issue for air quality modelling is to quantify the emission source strength variation of biogenic volatile organic compounds (BVOC) on different temporal and spatial scales. In Germany, this variation has been investigated for forests (the major source of BVOC) at country, state, and local scales over 10 years. Hourly emission rates for each vegetation period (April to October) from 1994 until 2003 were calculated in 10 km resolution. A database was compiled containing land cover, forest distribution, foliar biomass density, leaf area index (LAI) and plant specific emission potential. Meteorological input parameters were obtained using the non-hydrostatic meteorological mesoscale model MM5. The semi-empirical BVOC model (seBVOC) uses these parameters as input. SeBVOC considers in addition seasonality of the emission potentials, light extinction within the canopy as well as leaf temperature, air humidity, wind speed, and solar angle. The results show an average BVOC emission of 366 Gg, with 40 Gg isoprene, 188 Gg monoterpenes, and 138 Gg other VOC (OVOC), for the period 1994-2003. The dominating emitter type is Norway spruce ( Picea abies) contributing approximately 40% to the total BVOC. In the years 1994-2003, the annual BVOC emissions varied in the range of ±20%. However, in specific episodes and at specific locations the variation is as high as 150% compared to average emissions. Also the BVOC composition emitted is location specific. Using a sensitivity analysis, the contribution of uncertainties in estimating foliar biomass, emission potential, as well as temperature to the overall uncertainty of calculated potential surface BVOC emission rates is addressed.

Smiatek, Gerhard; Steinbrecher, Rainer

81

Sensitivity of ozone concentrations to VOC and NO x emissions in the Canadian Lower Fraser Valley  

Microsoft Academic Search

The SAPRC90 chemical mechanism module implemented in CALGRID is updated for the specific emissions and applications of the Lower Fraser Valley (LFV) of British Columbia, Canada. The kinetic and mechanistic parameters of lumped VOC reactions recalculated using the LFV emissions profiles are noticeably different from those based on default emissions profiles, indicating the importance of tailoring the parameters to specific

Weimin Jiang; Donald L. Singleton; Mark Hedley; Robert McLaren

1997-01-01

82

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

83

Odorous VOC emissions following land application of swine manure slurry  

Technology Transfer Automated Retrieval System (TEKTRAN)

Swine manure is often applied to crop land as a fertilizer source. Odor emissions from land-applied swine manure may pose a possible nuisance to downwind populations if not applied with sufficient forethought. A research project was conducted to assess the time decay of odorous volatile organic co...

84

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

85

Temporal, spatial characteristics and uncertainty of biogenic VOC emissions in the Pearl River Delta region, China  

NASA Astrophysics Data System (ADS)

Using the Global Biosphere Emissions and Interactions System model (GloBEIS), 3 × 3 km gridded and hourly biogenic volatile organic compound (BVOC) emissions in the Pearl River Delta (PRD) were estimated for the year 2006. The study used newly available land cover database, observed meteorological data, and recent measurements of emission rates for tree species in China. The results show that the total BVOC emission in the PRD region in 2006 was 296 kt (2.2 × 10 11 gC), of which isoprene contributes about 25% (73 kt, 6.4 × 10 10 gC), monoterpenes about 34% (102 kt, 8.9 × 10 10 gC), and other VOCs (OVOC) about 41% (121 kt, 6.8 × 10 10 gC). BVOC emissions in the PRD region exhibit a marked seasonal pattern with the peak emission in July and the lowest emission in January, and are mainly distributed over the outlying areas of the PRD region, where the economy and land use are less developed. The uncertainties in BVOC emission estimates were quantified using Monte Carlo simulation; the results indicate high uncertainties in isoprene emission estimates, with a relative error of -82 to +177%, ranging from 12.4 to 186.4 kt; -41 to +58% uncertainty for monoterpenes emissions, ranging from 67.7 to 181.9 kt; and -26 to +30% uncertainty in OVOC emissions, ranging from 88.8 to 156.2 kt on the 95% confidence intervals. The key uncertainty sources include emission factors and the model empirical coefficients ?, CT1, C L, and Eopt for estimating isoprene emission, and emission factors and foliar density for estimating monoterpenes and OVOC emissions. This implies that determining these empirical coefficient values properly and conducting more field measurements of emission rates of tree species are key approaches for reducing uncertainties in BVOC emission estimates. Improving future BVOC emission inventory work in the PRD region requires giving priority to research on shrub land, coniferous forests, and irrigated cropland and pasture.

Zheng, Junyu; Zheng, Zhuoyun; Yu, Yufan; Zhong, Liuju

2010-05-01

86

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

Microsoft Academic Search

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

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

2002-01-01

87

Testing VOC emission measurement techniques in wood-coating industrial processes and developing a cost-effective measurement methodology  

Microsoft Academic Search

Availability of reliable emission measurements of concentrated volatile organic compounds (VOCs) bear great significance in facilitating the selection of a feasible emission abatement technique. There are numerous methods, which can be used to measure VOC emissions, however, there is no single method that would allow sampling of the whole range of volatile organics. In addition, research efforts are usually directed

S. Ojala; U. Lassi; R. L. Keiski

2006-01-01

88

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

89

Projections of SO2, NOx, NH3 and VOC Emissions in East Asia Up to 2030  

Microsoft Academic Search

Starting from an inventory of SO2, NOx, VOC and NH3 emissions for the years 1990 and 1995 in East Asia (Japan, South and North Korea, China, Mongolia and Taiwan), the temporal development of the emissions of the four air pollutants is projected to the year 2030 based on scenarios of economic development. The projections are prepared at a regional level

Z. Klimont; J. Cofala; W. Schöpp; M. Amann; D. G. Streets; Y. Ichikawa; S. Fujita

2001-01-01

90

CHARACTERIZATION AND REDUCTION OF FORMALDEHYDE EMISSIONS FROM A LOW-VOC LATEX PAINT: JOURNAL ARTICLE  

EPA Science Inventory

NRMRL-RTP-P- 474a Chang*, J.C.S., Guo*, Z., Fortmann, R.C., and Lao, H.-C. Characterization and Reduction of Formaldehyde Emissions from a Low-VOC Latex Paint. Indoor Air 12 (1):10-16 (2002). EPA/600/J-02/187. 01/10/2000 The patterns of formaldehyde emission from a low vol...

91

On speciation of VOC localization  

NASA Astrophysics Data System (ADS)

Most of the gas-phase chemical mechanisms successfully used in gas-phase atmospheric chemical processes, such as CBM-Z, RADM2 or SAPRC-07, treat hundreds of VOC as lumped organic species by their chemical characteristics. Most of the model results are compared with total VOC observations, and it is not appropriate to compare lumped VOC simulations to observations even if there are separate VOC observations like Photochemical Assessment Monitoring Stations (PAMS). While the PAMS Air Quality Model (PAMS-AQM) is developed, separate organic species observed by PAMS without a doubt can be directly compared with model simulations. From the past case study (Chen et al., 2010), it shows a major and very significant finding in that detailed emissions of VOC in the existing emissions database are often in error in Taiwan or other countries due to the fact that the annual VOC emissions are classified into hundreds of species-specific emissions by using the speciation factors following the protocol of the U.S. EPA (AP-42). Based on all PAMS observations from 2006-2007, four base cases with well comparable meteorological simulations were selected for the unified correction for all sources in Taiwan. After the PAMS species emissions are modified, the diurnal patterns and simulation-observation correlation for most of the PAMS species are improved, and the concentration levels are more comparable with those of observations. More expanded case studies also revealed necessary corrections for the PAMS species emissions. Sensitivity analyses for lumped organic species with modified PAMS species emissions are also conducted. After modified PAMS emissions are added into lumped VOC emissions, there is an increase of only 10% of totally VOC emissions. While the sources of the lumped VOC emissions are changed, ozone formation shows no significant change with modified lumped VOC emissions. This helps to support the argument that for ozone simulation, the lumped VOC processes balance out any shortcomings in VOC details and the simulation of oxidant levels remain unchanged. But for the detail emissions of VOC, one can find out the error with local VOC speciation and make corrections.

Chen, S.; Chang, J.; Wang, J.

2011-12-01

92

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

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

93

GLOBAL INVENTORY OF VOLATILE ORGANIC COMPOUND EMISSIONS FROM ANTHROPOGENIC SOURCES  

EPA Science Inventory

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

94

Control of VOC emissions from natural gas pipeline compressor station engines. Topical report, June 1990-January 1991  

SciTech Connect

The objective of the study was to develop information in support of the following areas: VOC control technology review for compressor station prime movers; Assessment of VOC/NOx control tradeoff for natural gas compressor stations. The major emphasis of the study was in the first area--VOC control technology review. In the second part of the study, Acurex was tasked to provide a general review of existing methods for evaluating VOC emissions control for ozone abatement and to recommend a method for VOC/NOx control tradeoff analysis.

Chu, E.K.

1991-01-01

95

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.

96

[VOC emission situation and control measures of gas station in China].  

PubMed

The emission factor is used to estimate the volatile organic compound (VOC) emission caused by gas station. After considering the economical, social and population factors, the activity rate was modified, and then the fuel consumption and VOC emission trend in the next 20 years can be predicted. The result shows the VOC emission from gas station in China 2002 was 187.6kt and this number will increase to 1196kt in 2030 if no further control measures will be implemented. And the economic loss caused by gasoline vapor arrived to 0.75 billion RMB in 2002 and will be 4.78 billion RMB in 2030. The cost-benefit approach of the commercially available gasoline vapor recovery technologies in China included Stage I, Stage II and on-board refueling vapor recovery (ORVR) were analyzed, and the result shows introducing these three systems will bring larger reduce of VOC emission, and the combination of them can do a even better job. Compared with Stage II, ORVR is more efficient and cheaper, but it will take long time to implement ORVR. And it will take at least 11 years in China to convert to ORVR above 80%. So Stage II vapor recovery system may be a short term option while ORVR should be treated as the ultimate solution for controlling the vapor emission from gas stations in the future. PMID:17111597

Shen, Min-Jia; Hao, Ji-Ming; Wang, Li-Tao

2006-08-01

97

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

98

Impact of air velocity, temperature, humidity, and air on long-term voc emissions from building products  

Microsoft Academic Search

The emissions of two volatile organic compounds (VOCs) of concern from five building products (BPs) were measured in the field and laboratory emission cell (FLEC) up to 250d. The BPs (VOCs selected on the basis of abundance and low human odor thresholds) were: nylon carpet with latex backing (2-ethylhexanol, 4-phenylcyclohexene), PVC flooring (2-ethylhexanol, phenol), floor varnish on pretreated beechwood parquet

Peder Wolkoff

1998-01-01

99

Composition and emissions of VOCs in main- and side-stream smoke of research cigarettes  

NASA Astrophysics Data System (ADS)

It is well known that mainstream (MS) and sidestream (SS) cigarette smoke contains a vast number of chemical substances. Previous studies have emphasized SS smoke rather than MS smoke to which smokers are exposed, and most have used chamber tests that have several disadvantages such as wall losses. Emissions from standard research cigarettes have been measured, but relatively few constituents have been reported, and only the 1R4F (low nicotine) cigarette type has been tested. This study provides a comprehensive characterization of total, MS and SS smoke emissions for the 1R5F (ultra low nicotine), 2R4F (low nicotine), and 1R3F (standard nicotine) research cigarettes research cigarettes, including emission factors for a number of toxic compounds (e.g., benzene) and tobacco smoke tracers (e.g., 2,5-dimethyl furan). Emissions of volatile organic compounds (VOCs) and particulate matter (PM) are quantified using a dynamic dilution emission measurement system that is shown to produce accurate, rapid and reproducible results for over 30 VOCs and PM. SS and MS emissions were accurately apportioned based on a mass balance of total emissions. As expected, SS emissions greatly exceeded MS emissions. The ultra low nicotine cigarette had lower emissions of most VOCs compared to low and standard nicotine cigarettes, which had similar emissions. Across the three types of cigarettes, emissions of benzene (296-535 ?g cig -1), toluene (541-1003 ?g cig -1), styrene (90-162 ?g cig -1), 2-dimethyl furan (71-244 ?g cig -1), naphthalene (15-18 ?g cig -1) and other VOCs were generally comparable to or somewhat higher than literature estimates using chamber tests.

Charles, Simone M.; Batterman, S. A.; Jia, Chunrong

100

Connecting top down and bottom up methods for characterizing VOC emissions from petrochemical facilities  

NASA Astrophysics Data System (ADS)

In the last decade, several measurement campaigns in the Houston Galveston Brazoria (HGB) area have uncovered striking differences between emissions of highly reactive volatile organic carbon (HR-VOC) species from industrial facilities reported to regulatory agencies and observed or inferred emissions based on atmospheric data. A review of measurement based emissions estimates in light of recent insights gained from a recent full-scale controlled flare operational measurements(TCEQ Flare Study) will be presented. Links between controlled flare emissions observations and specific types of industrial operations emission will be discussed. Some of the atmospheric measurement datasets are sufficiently complete to compute specific flare combustion characteristics. One such metric, destruction and removal efficiency (DRE) directly informs inventory development by connecting the reported vent gas flow rates to HR-VOC emissions. The impact of the improved emissions estimate on HGB ambient ozone will be discussed. Primary formaldehyde emissions and the potential 'trade-off' between decreasing HR-VOC and increasing black carbon particulate emissions will also be discussed.

Herndon, S. C.; Wood, E. C.; Fortner, E.; Knighton, W. B.; Kolb, C. E.; Torres, V.; Al-Fadhli, F.; McDonald-Buller, E.; Allen, D.

2011-12-01

101

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...

102

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

103

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

Microsoft Academic Search

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

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

2006-01-01

104

MODELED RESPONSE OF PHOTOCHEMICAL OXIDANTS TO SYSTEMATIC REDUCTIONS IN ANTHROPOGENIC VOC AND NOX EMISSIONS  

EPA Science Inventory

As an exercise in model sensitivity, the Environmental Protection Agency's Regional Oxidant Model (ROM) was run for several simulations to study the impact of across-the-board reductions in anthropogenic VOC and NOx emissions on the photochemical environment of the eastern United...

105

Vertically fired fume incinerator reduces VOC, HCl emissions while adapting to limited space  

Microsoft Academic Search

Merck's Flint River plant in Albany, GA had been concerned with the control of dimethylsulfide (DMS) and methyl chloride. In November 1980, the state of Georgia enacted air pollution regulations requiring a 90% (by weight) reduction of all volatile organic compound (VOC) emission. A complete vertical incineration system was selected that could easily be installed in the available area. Total

D. A. Olson; C. P. Wickersham

1985-01-01

106

SURFACE-COATING-FREE MATERIALS AND REDUCTION OF VOC EMISSIONS FROM COATING OPERATIONS  

EPA Science Inventory

The paper discusses results of a July 1991 workshop, cosponsored by EPA and RTI, to explore the concept of surface-coating-free materials (SCFMs) and to discuss their use as a means of reducing volatile organic compound (VOC) and air toxic emissions from surface coating operation...

107

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

EPA Science Inventory

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

108

New observations of VOC emissions and concentrations in, above, and around the Central Valley of California  

NASA Astrophysics Data System (ADS)

Large portions of the Central Valley of California are out of compliance with current state and federal air quality standards for ozone and particulate matter, and the relative importance of biogenic and anthropogenic VOC emissions to their photochemical production in this region remains uncertain. In 2009-2011 multiple measurement campaigns were completed investigating the VOC emission inventory and concentration distributions. In 2009 BVOC emissions from more than 20 species of major agricultural crops in California were measured in a greenhouse using branch enclosures by both PTRMS and in-situ GC. Overall, crops were found to emit low amounts of BVOC compared to the natural forests surrounding the valley. Crops mainly emitted methanol and terpenes, with a broad array of other species emitted at lower levels, and all the measured crops showed negligible emissions of isoprene. Navel oranges were the largest crop BVOC emitters measured so a full year of flux measurements were made in an orange grove near Visalia in 2010 by eddy covariance(EC)-PTRMS with two multi-week periods of concentration measurements by hourly in-situ GC, and one month of high mass resolution flux measurements by EC-PTR-TOF-MS. The dominant BVOC emissions from the orange grove were methanol and terpenes, followed by acetone, acetaldehyde, and a low level of emissions for many other species. In 2011 aircraft eddy covariance measurements of BVOC fluxes were made by EC-PTRMS covering a large area of California as part of the California Airborne Bvoc Emission Research in Natural Ecosystem Transects (CABERNET) campaign aimed at improving BVOC emission models on regional scales, mainly profiling BVOC emissions from oak woodlands surrounding the Central Valley. In 2010, hourly in-situ VOC measurements were made via in-situ GC in Bakersfield, CA as part of the CalNex experiment. Additionally, in-situ measurements of fresh motor vehicle exhaust were made in Oakland's Caldecott tunnel. Measurements by in-situ GC included more than 200 anthropogenic and biogenic VOCs with a wide range of volatilities (up to 17 carbon atoms in size) and various functional groups (e.g. aldehydes, ketones, alcohols, halogens, sulfur, & nitrogen). Finally, in 2011 vertical profiles of VOC were made at 5 heights on a communication tower at Walnut Grove (~20 miles south of Sacramento) from 30' to 1550' by PTRMS. Results from all of these studies combined provide a novel overview of the distribution of VOC emissions and concentrations in, around, and above the Central Valley of California.

Goldstein, A. H.; Fares, S.; Gentner, D. R.; Park, J.; Weber, R.; Ormeno, E.; Holzinger, R.; Misztal, P. K.; Karl, T. R.; Guenther, A. B.; Fischer, M. L.; Harley, R. A.; Karlik, J. F.

2011-12-01

109

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

Microsoft Academic Search

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

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

2005-01-01

110

VOC PREVENTION OPTIONS FOR SURFACE COATING  

EPA Science Inventory

The paper discusses some of the volatile organic compound (VOC) prevention options for surface coating. Most small surface coating industries are considered to be stationary area sources. Although stationary area sources may account for as much as 50% of national VOC emissions, t...

111

Seasonality of monoterpene emission potentials in Quercus ilex and Pinus pinea: Implications for regional VOC emissions modeling  

NASA Astrophysics Data System (ADS)

VOC emissions from terrestrial ecosystems provide one of the principal controls over oxidative photochemistry in the lower atmosphere and the resulting air pollution. Such atmospheric processes have strong seasonal cycles. Although similar seasonal cycles in VOC emissions from terrestrial ecosystems have been reported, regional emissions inventories generally omit the effect of seasonality on emissions. We compiled measurement data on seasonal variations in monoterpene emissions potentials for two evergreen species (Quercus ilex and Pinus pinea) and used these data to construct two contrasting seasonal response functions for the inclusion in monoterpene emission models. We included these responses in the Niinemets et al. model and compared simulation results to those of the MEGAN model, both with and without its predicted seasonality. The effect of seasonality on regional monoterpene emissions inventories for European Mediterranean forests dominated by these species was tested for both models, using the GOTILWA+ biosphere model platform. The consideration of seasonality in the Niinemets et al. model reduced total estimated annual monoterpene emissions by up to 65% in some regions, with largest reductions at lower latitudes. The MEGAN model demonstrated a much weaker seasonal response than that in the Niinemets et al. model, and did not capture the between species seasonality differences found in this study. Results suggest that previous regional model inventories based on one fixed emission factor likely overestimate regional emissions, and species-specific expressions of seasonality may be necessary. The consideration of seasonality both largely reduces monoterpene emissions estimates, and changes their expected seasonal distribution.

Keenan, Trevor; Niinemets, ÜLo; Sabate, Santi; Gracia, Carlos; PeñUelas, Josep

2009-11-01

112

Emissions and photochemistry of oxygenated VOCs in urban plumes in the Northeastern United States  

NASA Astrophysics Data System (ADS)

Photochemical processes inside urban plumes in the Northeast of the United States have been studied using a highly detailed chemical model, based upon the Master Chemical Mechanism (MCM). The model results have been compared to measurements of oxygenated VOCs (acetone, methyl ethyl ketone, acetaldehyde, acetic acid and methanol) obtained during several flights of the NOAA WP-3D aircraft, which sampled plumes from the New York City area during the ICARTT campaign in 2004. The agreement between the model and the measurements was within 40 60% for all species, except acetic acid. The model results have been used to study the formation and photochemical evolution of acetone, methyl ethyl ketone and acetaldehyde. Under the conditions encountered during the ICARTT campaign, acetone is produced from the oxidation of propane (24 28%) and i-propanol (<15%) and from a number of products of i-pentane oxidation. Methyl ethyl ketone (MEK) is mostly produced from the oxidation of n-butane (20 30%) and 3-methylpentane (<40%). Acetaldehyde is formed from several precursors, mostly small alkenes, >C5 alkanes, propanal and MEK. Ethane and ethanol oxidation account, respectively, for 6 23% and 5 25% of acetaldehyde photochemical formation. The results highlight the importance of long-chain alkanes for the photochemical production of ketones and the role of hydroperoxides in sustaining their formation far from the emission sources.

Sommariva, R.; de Gouw, J. A.; Trainer, M.; Atlas, E.; Goldan, P. D.; Kuster, W. C.; Warneke, C.; Fehsenfeld, F. C.

2008-06-01

113

Emissions and photochemistry of oxygenated VOCs in urban plumes in the Northeastern United States  

NASA Astrophysics Data System (ADS)

Photochemical processes inside urban plumes in the Northeast of the United States have been studied using a highly detailed chemical model, based upon the Master Chemical Mechanism (MCM). The model results have been compared to measurements of oxygenated VOCs (acetone, methyl ethyl ketone, acetaldehyde, acetic acid and methanol) obtained during several flights of the NOAA WP-3D aircraft, which sampled plumes from the New York City area during the ICARTT campaign in 2004. The agreement between the model and the measurements was within 40-60 % for all species, except acetic acid. The model results have been used to study the formation and photochemical evolution of acetone, methyl ethyl ketone and acetaldehyde. Under the conditions encountered during the ICARTT campaign, acetone is produced from the oxidation of propane (24-28 %) and i-propanol (<15 %) and from a number of products of i-pentane oxidation. Methyl ethyl ketone (MEK) is mostly produced from the oxidation of n-butane (20-30 %) and 3-methylpentane (<40 %). Acetaldehyde is formed from several precursors, mostly small alkenes, >C5 alkanes, propanal and MEK. Ethane and ethanol oxidation account, respectively, for 6-23 % and 5-25 % of acetaldehyde photochemical formation. The results highlight the importance of alkanes for the photochemical production of ketones and the role of hydroperoxides in sustaining their formation far from the emission sources.

Sommariva, R.; de Gouw, J. A.; Trainer, M.; Atlas, E.; Goldan, P. D.; Kuster, W. C.; Warneke, C.; Fehsenfeld, F. C.

2011-07-01

114

EXPERIMENTAL ASSESSMENT OF NON-THERMAL PLASMA TECHNIQUES FOR REMOVAL OF PAPER INDUSTRY VOC EMISSIONS  

Microsoft Academic Search

The experimental assessment of non-thermal plasma techniques for treating of volatile organic compounds (VOCs) emissions from the paper industry was performed. Two types of non-thermal discharges were tested: non-equilibrium gliding arc discharge and pulsed streamer corona discharge. For the compounds of interest in this study (methanol, acetone, dimethyl sulfide and ? -pinene), high removal efficiencies were obtained with power levels

Mario G. Sobacchi; Alexei V. Saveliev; Alexander A Fridman; Alexander Gutsol; Lawrence A. Kennedy

115

APPORTIONMENT OF RESIDENTIAL INDOOR AEROSOL, VOC, AND ALDEHYDE SPECIES TO INDOOR AND OUTDOOR SOURCES, AND THEIR SOURCE STRENGTHS  

EPA Science Inventory

The average concentrations of forty-five fine particle aerosol, VOC and aldehyde species measured in ten Boise ID residences in wintertime have been apportioned according to their contributions from all inside sources and all outside sources. he method depends on the availability...

116

Summary of joint DOD/EPA research to control VOCs and toxic emissions. Rept. for Sep 84-Feb 91  

SciTech Connect

The paper summarizes the results of joint projects conducted during the last 6 years by the Department of Defense and EPA to control volatile organic compounds (VOCs) and toxic emissions. Major emphasis has been on product coating and metal finishing: (1) paint stripping using plastic media blasting, (2) carbon adsorption for methylchloroform and Freon emissions, (3) fluidized-bed catalytic incineration and hybrid carbon adsorption incineration, (4) paint spray booth wet-to-dry conversion, and (5) catalytic oxidation for controlling chlorinated VOCs.

Darvin, C.H.; Wander, J.D.

1991-01-01

117

Emission characteristics of VOCs from three fixed-roof p-xylene liquid storage tanks.  

PubMed

This study evaluates emission characteristics of volatile organic compounds (VOCs) caused by standing loss (L S) and working loss (L W) of three vertical fixed-roof p-xylene (p-X) liquid tanks during 1-year storage and filling operation. The annual net throughput of the tanks reached 70,446 t, resulting in 9,425 kg of p-X vapor emission including 5,046 kg of L S (53.54 %) and 4,379 kg of L W (46.46 %). The estimated L W of AP-42 displayed better agreement with the measured values of a VOC detector than the estimated L S of AP-42. The L S was best correlated with the liquid height of the tanks, while the L W was best correlated with the net throughput of the tanks. As a result, decreasing vapor space volume of the tanks and avoiding high net throughput of the tanks in a high ambient temperature period were considered as effective means to lessen VOC emission from the fixed-roof organic liquid storage tank. PMID:23307101

Lu, Chungsying; Huang, Hsiaoyun; Chang, Shenteng; Hsu, Shihchieh

2013-01-12

118

Dynamic relationship between the VOC emissions from a Scots pine stem and the tree water relations  

NASA Astrophysics Data System (ADS)

The stems of coniferous trees contain huge storages of oleoresin. The composition of oleoresin depends on e.g. tree species, age, provenance, health status, and environmental conditions. Oleoresin is under pressure in the extensive network of resin ducts in wood and needles. It flows out from a mechanically damaged site to protect the tree by sealing the wounded site. Once in contact with air, volatile parts of oleoresin evaporate, and the residual compounds harden to make a solid protective seal over damaged tissues. The hardening time of the resin depends on evaporation rate of the volatiles which in turn depends on temperature. The storage is also toxic to herbivores and attracts predators that restrict the herbivore damage. Despite abundant knowledge on emissions of volatile isoprenoids from foliage, very little is known about their emissions from woody plant parts. We set up an experiment to measure emissions of isoprene and monoterpenes as well as two oxygenated VOCs, methanol and acetone, from a Scots pine (Pinus sylvestris) stem and branches. The measurements were started in early April and continued until mid-June, 2012. Simultaneously, we measured the dynamics of whole stem and xylem diameter changes, stem sap flow rate and foliage transpiration rate. These measurements were used to estimate A) pressure changes inside the living stem tissue and the water conducting xylem, B) the refilling of stem water stores after winter dehydration (the ratio of sap flow at the stem base to water loss by foliage), and C) the increase in tree water transport capacity (the ratio of maximum daily sap flow rate to the diurnal variation in xylem pressure) during spring due to winter embolism refilling and/or the temperature dependent root water uptake capacity. The results show that already very early in spring, significant VOC emissions from pine stem can be detected, and that they exhibit a diurnal cycle similar to that of ambient temperature. During the highest emission period a sudden decrease in stem diameter was observed, which we hypothesize could either indicate a decrease in the pressure of living cells in connection with stem VOC emissions, or result mechanically from exudation of oleoresin from the stem. We also found that the stem water stores and xylem water transport capacity increased during periods of VOC emissions, which indicates xylem embolism refilling during times of VOC emissions. A qualitative difference was found between VOC emissions from pine stem and thick branches, the stem emissions containing more sesquiterpenes. Most of the tree biomass is in the lower part of the stem, and as stem tissues are lacking green photosynthesizing tissue the emissions are supposed to be related to damage. Our results show that emissions from tree stems are connected to the tree water relations and that they are important during the period when the foliage still is rather inactive.

Vanhatalo, Anni; Chan, Tommy; Aalto, Juho; Kolari, Pasi; Rissanen, Kaisa; Hakola, Hannele; Hölttä, Teemu; Bäck, Jaana

2013-04-01

119

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

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

120

Evaluations of NOx and highly reactive VOC emission inventories in Texas and their implications for ozone plume simulations during the Texas Air Quality Study 2006  

NASA Astrophysics Data System (ADS)

Satellite and aircraft observations made during the 2006 Texas Air Quality Study (TexAQS) detected strong urban, industrial and power plant plumes in Texas. We simulated these plumes using the Weather Research and Forecasting - Chemistry (WRF-Chem) model with input from the US EPA's 2005 National Emission Inventory (NEI-2005), in order to evaluate emissions of nitrogen oxides (NOx = NO + NO2) and volatile organic compounds (VOCs) in the cities of Houston and Dallas-Fort Worth. We compared the model results with satellite retrievals of tropospheric nitrogen dioxide (NO2) columns and airborne in-situ observations of several trace gases including NOx and a number of VOCs. The model and satellite NO2 columns agree well for regions with large power plants and for urban areas that are dominated by mobile sources, such as Dallas. However, in Houston, where significant mobile, industrial, and in-port marine vessel sources contribute to NOx emissions, the model NO2 columns are approximately 50 %-70 % higher than the satellite columns. Similar conclusions are drawn from comparisons of the model results with the TexAQS 2006 aircraft observations in Dallas and Houston. For Dallas plumes, the model-simulated NO2 showed good agreement with the aircraft observations. In contrast, the model-simulated NO2 is ~60 % higher than the aircraft observations in the Houston plumes. Further analysis indicates that the NEI-2005 NOx emissions over the Houston Ship Channel area are overestimated while the urban Houston NOx emissions are reasonably represented. The comparisons of model and aircraft observations confirm that highly reactive VOC emissions originating from industrial sources in Houston are underestimated in NEI-2005. The update of VOC emissions based on Solar Occultation Flux measurements during the field campaign leads to improved model simulations of ethylene, propylene, and formaldehyde. Reducing NOx emissions in the Houston Ship Channel and increasing highly reactive VOC emissions from the point sources in Houston improve the model's capability of simulating ozone (O3) plumes observed by the NOAA WP-3D aircraft, although the deficiencies in the model O3 simulations indicate that many challenges remain for a full understanding of the O3 formation mechanisms in Houston.

Kim, S.-W.; McKeen, S. A.; Frost, G. J.; Lee, S.-H.; Trainer, M.; Richter, A.; Angevine, W. M.; Atlas, E.; Bianco, L.; Boersma, F. K.; Brioude, J.; Burrows, J. P.; de Gouw, J.; Fried, A.; Gleason, J.; Hilboll, A.; Mellqvist, J.; Peischl, J.; Richter, D.; Rivera, C.; Ryerson, T.; Te Lintel Hekkert, S.; Walega, J.; Warneke, C.; Weibring, P.; Williams, E.

2011-07-01

121

Evaluations of NOx and highly reactive VOC emission inventories in Texas and their implications for ozone plume simulations during the Texas Air Quality Study 2006  

NASA Astrophysics Data System (ADS)

Satellite and aircraft observations made during the 2006 Texas Air Quality Study (TexAQS) detected strong urban, industrial and power plant plumes in Texas. We simulated these plumes using the Weather Research and Forecasting-Chemistry (WRF-Chem) model with input from the US EPA's 2005 National Emission Inventory (NEI-2005), in order to evaluate emissions of nitrogen oxides (NOx = NO + NO2) and volatile organic compounds (VOCs) in the cities of Houston and Dallas-Fort Worth. We compared the model results with satellite retrievals of tropospheric nitrogen dioxide (NO2) columns and airborne in-situ observations of several trace gases including NOx and a number of VOCs. The model and satellite NO2 columns agree well for regions with large power plants and for urban areas that are dominated by mobile sources, such as Dallas. However, in Houston, where significant mobile, industrial, and in-port marine vessel sources contribute to NOx emissions, the model NO2 columns are approximately 50%-70% higher than the satellite columns. Similar conclusions are drawn from comparisons of the model results with the TexAQS 2006 aircraft observations in Dallas and Houston. For Dallas plumes, the model-simulated NO2 showed good agreement with the aircraft observations. In contrast, the model-simulated NO2 is ~60% higher than the aircraft observations in the Houston plumes. Further analysis indicates that the NEI-2005 NOx emissions over the Houston Ship Channel area are overestimated while the urban Houston NOx emissions are reasonably represented. The comparisons of model and aircraft observations confirm that highly reactive VOC emissions originating from industrial sources in Houston are underestimated in NEI-2005. The update of VOC emissions based on Solar Occultation Flux measurements during the field campaign leads to improved model simulations of ethylene, propylene, and formaldehyde. Reducing NOx emissions in the Houston Ship Channel and increasing highly reactive VOC emissions from the point sources in Houston improve the model's capability of simulating ozone (O3) plumes observed by the NOAA WP-3D aircraft, although the deficiencies in the model O3 simulations indicate that many challenges remain for a full understanding of the O3 formation mechanisms in Houston.

Kim, S.-W.; McKeen, S. A.; Frost, G. J.; Lee, S.-H.; Trainer, M.; Richter, A.; Angevine, W. M.; Atlas, E.; Bianco, L.; Boersma, K. F.; Brioude, J.; Burrows, J. P.; de Gouw, J.; Fried, A.; Gleason, J.; Hilboll, A.; Mellqvist, J.; Peischl, J.; Richter, D.; Rivera, C.; Ryerson, T.; Te Lintel Hekkert, S.; Walega, J.; Warneke, C.; Weibring, P.; Williams, E.

2011-11-01

122

Silent discharge plasma for point-of-use abatement of VOC emissions. Final report ESHCOO3(b)  

SciTech Connect

Los Alamos and SEMATECH have evaluated a silent discharge plasma (SDP) device for point-of-use (POU) control of specific semiconductor VOC emissions at the source. Destruction efficiencies were initially determined at the bench scale using controlled gas mixtures and system performance was measured for simulated emissions containing a variety of volatile organic compounds (including HMDS) and PFCs. Based on this work, a field-pilot unit was designed and tested at a SEMATECH member site using two slip-streams: (1) PGMEA and HMDS gas mixture from lithography tools and the, (2) acetone, PCE and methanol from a wet bench cleaning tool. Based on the pilot test data, CoO estimates for the SDP technology show annual operating expenses (including amortized capital and installation costs, maintenance, and utilities) are $8.3K for a single 250 scfm lithotrack tool. End-of-pipe (EOP) system costs are $33.3K per 1000 scfm as compared to about $22K per 1000 scfm for a typical EOP concentrator/thermal abatement system. LANL does not recommend replacing existing EOP systems with SDP. However SDP could be easily installed in {open_quotes}niche{close_quotes} circumstances for POU control of VOCs from lithotrack tools.

Coogan, J.J.; Jassal, A.

1997-02-14

123

Application of CSIA to distinguish between vapor intrusion and indoor sources of VOCs.  

PubMed

At buildings with potential for vapor intrusion of volatile organic chemicals (VOCs) from the subsurface, the ability to accurately distinguish between vapor intrusion and indoor sources of VOCs is needed to support accurate and efficient vapor intrusion investigations. We have developed a method for application of compound-specific stable isotope analysis (CSIA) for this purpose that uses an adsorbent sampler to obtain sufficient sample mass from the air for analysis. Application of this method to five residences near Hill Air Force Base in Utah indicates that subsurface and indoor sources of tricholorethene and tetrachloroethene often exhibit distinct carbon and chlorine isotope ratios. The differences in isotope ratios between indoor and subsurface sources can be used to identify the source of these chemicals when they are present in indoor air. PMID:21650208

McHugh, Thomas; Kuder, Tomasz; Fiorenza, Stephanie; Gorder, Kyle; Dettenmaier, Erik; Philp, Paul

2011-06-21

124

VOC emissions from Norway spruce ( Picea abies L. [Karst]) twigs in the field—Results of a dynamic enclosure study  

NASA Astrophysics Data System (ADS)

During the 2002 summer intensive field campaign of BEWA2000 a proton-transfer-reaction mass spectrometer (PTR-MS) was used for online determination of volatile organic compounds (VOC) emitted by Norway spruce ( Picea abies L. [Karst]) twigs in a dynamic sampling enclosure. Emissions of isoprenoids (isoprene and monoterpenes) and oxygenated VOC (OVOC; acetaldehyde, acetone, methanol, and ethanol) were investigated. Emissions showed clear diurnal patterns with high daytime emission rates amounting to 1.8 ?g C g -1 dwt h -1 for the sum of monoterpenes and in the range of 0.1 to 0.6 ?g C g -1 dwt h -1 for isoprene>acetone>ethanol>methanol. Data were used to validate existing models on isoprene and monoterpene emissions and to discuss environmental and physiological factors affecting VOC emissions. Isoprene and acetaldehyde emission rates were best modelled applying the Guenther 1993 temperature and solar radiation algorithm. Emissions of monoterpenes, acetone and ethanol were best described by a temperature-only exponential algorithm. Using these model approaches a maximum emission variability of 66% was covered (isoprene). Poor r2 values ranging from 0.15 to 0.42 were typical for oxygenated VOC emission modelling indicating the need for model improvement e.g. development of process-based models describing the emission as a result of biochemical de novo synthesis as well as physico-chemical transport properties inside the leaves.

Grabmer, W.; Kreuzwieser, J.; Wisthaler, A.; Cojocariu, C.; Graus, M.; Rennenberg, H.; Steigner, D.; Steinbrecher, R.; Hansel, A.

125

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

126

COST EFFECTIVE VOC EMISSION CONTROL STARTEGIES FOR MILITARY, AEROSPACE,AND INDUSTRIAL PAINT SPRAY BOOTH OPERATIONS: COMBINING IMPROVED VENTILATION SYSTEMS WITH INNOVATIVE, LOW COST EMISSION CONTROL TECHNOLOGIES  

EPA Science Inventory

The paper describes a full-scale demonstration program in which several paint booths were modified for recirculation ventilation; the booth exhaust streams are vented to an innovative volatile organic compound (VOC) emission control system having extremely low operating costs. ...

127

Associations between immune function in yearling beef cattle and airborne emissions of sulfur dioxide, hydrogen sulfide, and VOCs from oil and natural gas facilities.  

PubMed

Researchers assessed the associations between airborne emissions from oil and gas field facilities and the structure and function of the immune system of yearling beef cattle in 27 herds during spring 2002. They evaluated the immune systems of these animals by enumerating B lymphocytes and T-lymphocyte subtypes (CD4, CD8, gammadelta, and WC1) in peripheral circulation and by measuring systemic antibody production in response to vaccination. Researchers prospectively measured exposure to sulfur dioxide, hydrogen sulfide, and volatile organic compounds (VOCs) by using air-quality data from passive monitors installed in pastures and wintering areas. They estimated the mean exposure of each animal over the 6-month period before the start of sample collection. The researchers used mixed models, which adjusted for clustering by herd and accounted for known risk factors, to examine potential associations between exposure to airborne sulfur dioxide, VOCs (measured as concentrations of benzene and toluene) and hydrogen sulfide, as well as proximity to emission sources (well-site density), and the immune system outcomes. Increasing exposure to VOCs measured as toluene was associated with significant CD4 T lymphocytopenia. The number of CD4 T lymphocytes was 30% lower in cattle exposed to VOCs measured as toluene in the highest quartile (> 0.823 microg/m3) than in cattle exposed in the lowest quartile (< 0.406 microg/m3). PMID:19179269

Bechtel, Daniel G; Waldner, Cheryl L; Wickstrom, Mark

2009-01-01

128

RERANKING OF AREA SOURCES IN LIGHT OF SEASONAL/ REGIONAL EMISSION FACTORS AND STATE/LOCAL NEEDS  

EPA Science Inventory

The report gives results of an effort to provide a better understanding of air pollution area sources and their emissions, to prioritize their importance as emitters of volatile organic compounds (VOCs), and to identify sources for which better emission estimation methodologies a...

129

Emission source strengths of gasoline-filling processes determined by open-path spectroscopic techniques and inverse modeling  

Microsoft Academic Search

Up to now emission source strengths of diffuse and heterogenous emission of important VOCs are not well known especially from gas stations and gasoline tank farms. To estimate the total emission of these sources non-intrusive measurements were performed by a differential optical absorption spectroscopy (DOAS) system to determine the path- integrated concentrations of exhaust compounds downwind of the source through

Klaus Schaefer; Martina Stockhause; Herbert Hoffmann; Achim Sedlmaier; Stefan M. Emeis

1998-01-01

130

Emissions of ozone precursors from stationary sources  

Microsoft Academic Search

This paper discusses and critiques methods used to estimate emissions of, and create both aggregate and detailed modeling inventories for, nitrogen oxides (NOx), volatile organic compounds (VOC) and carbon monoxide (CO), the main pollutants involved in ozone formation. Emissions of sulfur dioxide (SO2) and methods to project emissions into the future are also briefly discussed. Many improvements have been made

M Placet; C. O Mann; R. O Gilbert; M. J Niefer

2000-01-01

131

[Forming potential of secondary organic aerosols and sources apportionment of VOCs in autumn of Shanghai, China].  

PubMed

A continuous measurement was conducted in urban area of Shanghai from 1stSeptember to 21st November, 2011. The mass concentration of PM2.5 and the mixing ratio of VOCs were obtained during the period. Four pollution episodes were observed: PD1 (20th-23th September), PD2 (5th-9th October), PD3 (13rd - 18th October), PD4 (10th - 14th November). The average mass concentrations of PM2.5 were (45+/-16), (76+/-46), (57+/-36) and (122+/-92) microg.m-3, respectively. The mixing ratio of VOCs were (30.87+/-30.77) x10(-9), (32.09+/-30.69) x10(-)9, (34.04+/-28.13) x10(-9) and (44.27+/-31.58) x10(-9). Alkane, alkene and aromatic hydrocarbons accounted for 53. 58% , 27. 89% , and 10. 96% of the total VOCs, respectively. The OH radical loss rate (LOH) and the ozone formation potential (OFP) were applied to assess the chemical reactivity of VOCs, the results showed that the alkenes and aromatics were the most important contributors to LOH and OFP in the atmosphere in the urban area of Shanghai, in autumn. Fractional aerosol coefficients (FAC) and the ratio of organic carbon to element carbon (OC/EC) were used to estimate the potential formation of secondary organic aerosols (SOA) in Shanghai, the SOA concentration values obtained by the two methods were 1.43 microg.m-3 and 4.54 microg.m-3, respectively. The value predicted by OC/EC was significantly higher, which was mainly due to the low amount of SOA precursors measured in this study. The aromatics were not only the most important contributors to OFP, but also important SOA precursors. By applying the positive matrix factorization (PMF) model, six major sources were extracted to identify the sources of VOCs in autumn in Shanghai, including vehicle exhaust (24.30%), incomplete combustion (17.39%), fuel evaporation (16.01%) , LPG/NG leakage (15.21%) , petrochemical industry (14.00% ), and paint/solvent usage (13.09%). Vehicle exhaust and paint/solvent usage contain abundant aromatics species which are the most important contributors to OFP and important SOA precursors. The above two sources contributed 37.39% of the total VOCs concentration. Hence, these sources should be listed as priority of air pollution control strategy for Shanghai in future. PMID:23668105

Wang, Qian; Chen, Chang-Hong; Wang, Hong-Li; Zhou, Min; Lou, Sheng-Rong; Qiao, Li-Ping; Huang, Cheng; Li, Li; Su, Lei-Yan; Mu, Ying-Ying; Chen, Yi-Ran; Chen, Ming-Hua

2013-02-01

132

Pulsed Corona Plasma Technology for Treating VOC Emissions from Pulp Mills  

SciTech Connect

Under the DOE Office of Industrial Technologies Forest Products program various plasma technologies were evaluated under project FWP 49885 ''Experimental Assessment of Low-Temperature Plasma Technologies for Treating Volatile Organic Compound Emissions from Pulp Mills and Wood Products Plants''. The heterogeneous pulsed corona discharge was chosen as the best non-equilibrium plasma technology for control of the vent emissions from HVLC Brownstock Washers. The technology for removal of Volatile Organic Compounds (VOCs) from gas emissions with conditions typical of the exhausts of the paper industry by means of pulsed corona plasma techniques presented in this work. For the compounds of interest in this study (methanol, acetone, dimethyl sulfide and ? -pinene), high removal efficiencies were obtained with power levels competitive with the present technologies for the VOCs removal. Laboratory experiments were made using installation with the average power up to 20 W. Pilot plant prepared for on-site test has average plasma power up to 6.4 kW. The model of the Pilot Plant operation is presented.

Fridman, Alexander A.; Gutsol, Alexander; Kennedy, Lawrence A.; Saveliev, Alexei V.; Korobtsev, Sergey V.; Shiryaevsky, Valery L.; Medvedev, Dmitry

2004-07-28

133

A MECHANISTIC MODEL FOR ESTIMATING VOC EMISSIONS FROM INDUSTRIAL PROCESS DRAINS PART I: THE UNDERLYING CHANNEL. (R823335)  

EPA Science Inventory

Recent research has indicated the potential for emissions of volatile organic compound (VOCs) from industrial process drains, and a need for better understanding of the mass transfer kinetics associated with such emissions. rn this study, a two-zone model was developed in a...

134

Summary of joint DOD\\/EPA research to control VOCs and toxic emissions. Rept. for Sep 84Feb 91  

Microsoft Academic Search

The paper summarizes the results of joint projects conducted during the last 6 years by the Department of Defense and EPA to control volatile organic compounds (VOCs) and toxic emissions. Major emphasis has been on product coating and metal finishing: (1) paint stripping using plastic media blasting, (2) carbon adsorption for methylchloroform and Freon emissions, (3) fluidized-bed catalytic incineration and

C. H. Darvin; J. D. Wander

1991-01-01

135

Light-duty vehicle PM and VOC speciated emissions at differing ambient temperatues with ethanol blend gasoline  

EPA Science Inventory

With the rise in the use of ethanol-blend gasoline in the U.S., interest is increasing in how these fuel blends affect PM and VOC emissions. EPA conducted a study characterizing emissions from two flex-fuel and one non-flex-fueled light-duty vehicles operated on a chassis dynamom...

136

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

EPA Science Inventory

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

137

Comparison of three small chamber test methods for the measurement of VOC emission rates from paint.  

PubMed

The aim of this study was to demonstrate a correlation between the measurement of emission rates of volatile organic compounds (VOCs) in three different climate chambers. In order to achieve this aim, the early state of the emission process in the three chambers was investigated and the effects of some important factors on the emission rates from paint were determined. The paper presents results of measurements in three different climate chambers. For the study, a 1-m3 chamber, a field and laboratory emission cell (FLEC), and a chamber for laboratory investigation of materials pollution and air quality (CLIMPAQ) were used. The airflow and surface area were selected so that the area-specific ventilation rates were identical in the three chambers. Temperature and relative humidity were identical during all the measurements. The paint examined was a solvent-based alkyd paint intended for indoor, which use contained between 30 and 60% of white spirit in wet condition. The paint was applied to electropolished and cleaned stainless steel plates. After application, the test material was stored for 14 days for drying in a well-ventilated conditioning room before the measurements were made. After 2 weeks storage, the most pronounced emissions were pentanal, hexanal, octanal, and decanol. The period before the emission rate stabilized differed for the three chambers studied. However, all chambers gave similar emission rates within the overall uncertainty used in these experiments. PMID:12756009

Afshari, A; Lundgren, B; Ekberg, L E

2003-06-01

138

Seasonal patterns of non-terpenoid C6-C10 VOC emission from seven Mediterranean woody species.  

PubMed

The seasonal pattern of non-terpenoid C6-C10 VOC emission by seven Mediterranean woody species (Bupleurum fruticosum, Cistus albidus, Pinus halepensis, Arbutus unedo, Erica arborea, Quercus coccifera, and Q. ilex) was studied under field conditions. Branch chamber samples were sorbed on carbotrap and analyzed by thermal desorption in combination with GC-MS. These non-terpenoid C6-C10 VOC emissions were large, almost of similar magnitude to those of terpenes. Overall, maximum values were recorded in spring and summer (up to 12 microg g(-1) DM h(-1) in Q. ilex) and minimum values in autumn and winter (up to 5 microg g(-1) DM h(-1) in Q. ilex). These C6-C10 VOC emissions represented 2.82% of the photosynthetic C fixation in summer and 0.22% in winter. Some compounds such as 2-ethoxyethyl acetate were emitted by most species, others such as 3-hexen-1-ol, phenol or decanal were significantly emitted only by few species. The greatest diversity of emitted non-terpenoid C6-C10 VOCs was observed in spring and in Q. ilex. Temperature seemed a strong driver of these seasonal changes but other species-specific and seasonal factors seem involved. These results indicate that C6-C10 non-terpenoid VOCs contribute a rather significant fraction of the total biogenic VOC flux from these Mediterranean species, especially in spring and summer, and therefore should be considered in VOC emission inventories and in model predictions of tropospheric chemistry. PMID:11592412

Peñuelas, J; Llusià, J

2001-10-01

139

[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

140

National survey of MTBE and other VOCs in community drinking-water sources  

USGS Publications Warehouse

Methyl tert-butyl ether (MTBE) is a volatile organic compound (VOC) that is added to gasoline either seasonally or year round in many parts of the United States to increase the octane level and to reduce carbon monoxide and ozone levels in the air. The chemical properties and widespread use of MTBE can result in contamination of private and public drinking-water sources. MTBE contamination is a concern in drinking water because of the compound's low taste and odor threshold and potential human-health effects.

Clawges, Rick M.; Rowe, Barbara L.; Zogorski, John S.

2001-01-01

141

Emissions of selected VOC from forests: First results on measurements needed for improvement and validation of emission models  

NASA Astrophysics Data System (ADS)

Biogenic volatile organic compounds (BVOCs) play a crucial role in the formation of photo-oxidants and particles through the diverse BVOC degradation pathways. Yet, current estimations about temporal and spatial BVOC emissions, including the specific BVOC mix are rather vague. This project addresses this issue by: the determination of (a) BVOC net emission rates and (b) primary emissions of BVOCs from the trees and soils. Measurement campaigns were carried out at the Waldstein site in the Fichtelgebirge in 2001 and 2002. Primary emissions of isoprenoids from the soil and from twigs of Norway spruce (Picea abies [L.] Karst.) and stand fluxes of isoprenoids were quantified by means of REA-technique with in situ GC-FID analysis and GC-MS analysis in the laboratory. Moreover, REA-samples obtained by the system were analysed by a PTR-MS. A critical value when using the REA approach is the Businger-Oncley parameter b. For this canopy type a b value of 0.39 (threshold velocity w_o = 0.6) was determined. The PTR-MS data show clear diurnal variations of ambient air mixing ratios of VOC such as isoprene and monoterpenes, but also of oxygenated VOCs such as carbonyls and alcohols and methylvinylketone (MVK) and methacrolein (MAK), products from isoprene degradation. Four selected trees (Picea abies [L.] Karst.) were intensively screened for primary BVOC emission rates. Most abundant species are b-pinene/sabinene and camphene. They show typical diurnal patterns with high emissions during daytime. Soil emissions of NO reached 250 nmol N m-2 s-1 at soil temperatures (in 3 cm depth) of 13^oC and at a relative air humidity of 60%. Ambient air mixing ratios near the soil surface of NO reached values of up to 0.7 ppb. NO_2 and ozone mixing ratios varied between 0.1 to 1.5 ppb and 10 to 37 ppb, respectively. As expected nitrogen oxide emissions rates tend to increase with increasing surface temperature. Isoprenoid emission from the soil was low and in general near the detection limit of 0.05 nmol m-2 s-1. Canopy fluxes of isoprene reached up to 7 nmol m-2 s-1 during daytime. At the same time MVK+MAK fluxes were about 30% lower. The fluxes of the sum of monoterpenes were in the same range. Striking were the sometimes very high fluxes of methanol and acetaldehyde of up to 80 nmol m-2 s-1.

Steigner, D.; Steinbrecher, R.; Rappenglück, B.; Gasche, R.; Hansel, A.; Graus, M.; Lindinger, Ch.

2003-04-01

142

Reducing odorous VOC emissions from swine manure using soybean peroxidase and peroxides.  

PubMed

The objective of the research was to determine the optimum application rates of soybean peroxidase (SBP) plus peroxide (SBPP) for reducing odorous VOC emissions from swine manure. Industrial-grade SBP was applied in combination with liquid hydrogen peroxide (H(2)O(2)) or powdered calcium peroxide (CaO(2)) to standard phenolic solutions and swine manure, and emissions were measured in a wind tunnel. The primary odorant in the untreated manure was 4-methylphenol, which accounted for 68-81% of the odor activity value. At the optimum application rate of SBPP (50 g L(-1)), 4-methylphenol emissions were reduced from the swine manure by 62% (H(2)O(2)) and 98% (CaO(2)) after 24h (P<0.0001). The CaO(2) had a longer residence time, remaining effective for 48 h with 92% reduction in emission rates (P<0.0001), while H(2)O(2) was similar to the control at 48 h (P=0.28). PMID:22985851

Parker, David B; Cai, Lingshuang; Kim, Ki-Hyun; Hales, Kristin E; Spiehs, Mindy J; Woodbury, Bryan L; Atkin, Audrey L; Nickerson, Kenneth W; Patefield, Krista D

2012-08-17

143

On-Road Measurement of Vehichle VOC Emission Measurements During the 2003 Mexico City Metropolitan Area Field Campaign  

NASA Astrophysics Data System (ADS)

In the spring of 2003 (April 1-May 5), a multinational team of experts conducted an intensive, five-week field campaign in the Mexico City Metropolitan Area (MCMA). The overall goal of this effort was to contribute to the understanding of the air quality problem in megacities. As part of the campaign the Aerodyne Mobile Laboratory was equipped with state-of-the-art analytical instruments and deployed for measuring a variety of vehicle emissions in real time including CO2, NO2, NH3, HCHO, VOC's and volatile (at 600 °C) aerosol. The on-road measurement of vehicle VOC emissions were performed using a commercial version of the IONICON PTR-MS modified to operate onboard the mobile lab platform. A summary of the PTR-MS results from these and supporting laboratory experiments will be presented and discussed. In particular, selected chase events will be presented to illustrate the utility of the PTR-MS technique for characterizing vehicle VOC emission profiles in real time. VOC emission profiles for different vehicle engine types which include gasoline, diesel and compressed natural gas will be discussed and compared to the measurements from other high time response instruments deployed on the Aerodyne mobile van.

Knighton, W. B.; Rogers, T.; Grimsrud, E.; Herndon, S.; Allwine, E.; Lamb, B.; Velasco, E.; Westberg, H.

2004-12-01

144

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

145

A rapid and accurate method, ventilated chamber C-history method, of measuring the emission characteristic parameters of formaldehyde/VOCs in building materials.  

PubMed

The indoor pollution caused by formaldehyde and volatile organic compounds (VOCs) emitted from building materials poses an adverse effect on people's health. It is necessary to understand and control the behaviors of the emission sources. Based on detailed mass transfer analysis on the emission process in a ventilated chamber, this paper proposes a novel method of measuring the three emission characteristic parameters, i.e., the initial emittable concentration, the diffusion coefficient and the partition coefficient. A linear correlation between the logarithm of dimensionless concentration and time is derived. The three parameters can then be calculated from the intercept and slope of the correlation. Compared with the closed chamber C-history method, the test is performed under ventilated condition thus some commonly-used measurement instruments (e.g., GC/MS, HPLC) can be applied. While compared with other methods, the present method can rapidly and accurately measure the three parameters, with experimental time less than 12h and R(2) ranging from 0.96 to 0.99 for the cases studied. Independent experiment was carried out to validate the developed method, and good agreement was observed between the simulations based on the determined parameters and experiments. The present method should prove useful for quick characterization of formaldehyde/VOC emissions from indoor materials. PMID:23994652

Huang, Shaodan; Xiong, Jianyin; Zhang, Yinping

2013-08-08

146

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

147

RERANKING OF AREA SOURCES IN LIGHT OF SEASONAL/REGIONAL EMISSION FACTORS AND STAE/LOCAL NEEDS  

EPA Science Inventory

The report gives results of an effort to provide a better understanding of air pollution area sources and their emissions, to prioritize their importance as emitters of volatile organic compounds (VOCs), and to identify sources for which better emission estimation methodologies a...

148

Development of a methodology examining the behaviours of VOCs source apportionment with micro-meteorology analysis in an urban and industrial area.  

PubMed

During summer 2009, online measurements of 25 Volatile Organic Compounds (VOCs) from C6 to C10 as well as micro-meteorological parameters were simultaneously performed in the industrial city of Dunkerque. With the obtained data set, we developed a methodology to examine how the contributions of different source categories depend on atmospheric turbulences, and the results provided identification of emission modes. Eight factors were resolved by using Positive Matrix Factorization model and three of them were associated with mixed sources. The observed behaviours of contributions with turbulences lead to attribute some factors with sources at ground level, and some other factors with sources in the upper part of surface layer. The impact of vertical turbulence on the pollutant dispersion is also affected by the distance between sources and receptor site. PMID:22243843

Xiang, Yang; Delbarre, Hervé; Sauvage, Stéphane; Léonardis, Thierry; Fourmentin, Marc; Augustin, Patrick; Locoge, Nadine

2011-11-13

149

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

150

VOC emissions from a boreal forest - direct ecosystem scale measurements by PTR-MS in 2006-2008  

NASA Astrophysics Data System (ADS)

To quantify emissions of oxygenated volatile organic compounds (OVOCs) in the ecosystem scale and to assess their importance in comparison with monoterpene emissions, we carried out micrometeorological flux measurements above a Scots pine forest in southern Finland in June-September 2006, March-September 2007, and May-August 2008. These direct measurements were conducted using the disjunct eddy covariance method and proton transfer reaction mass spectrometry (PTR-MS) was used for the associated VOC mixing ratio measurements. OVOC emissions consisted of methanol, acetaldehyde, and acetone. They were of the same order of magnitude as monoterpene emissions. The compatibility of the measured monoterpene emissions with the traditional temperature dependent emission algorithm was reasonable. The measurement data will be used to study the seasonal and interannual variability of emissions.

Taipale, R.; Ruuskanen, T. M.; Kajos, M. K.; Patokoski, J.; Hakola, H.; Rinne, J.

2009-04-01

151

VOC as Renewable energy source for textile coating process: application of catalytic combustion, temperature swing adsorption method and electrically heated catalyst system  

Microsoft Academic Search

We had developed a newly improved textile coating process with much decrease of the emission of volatile organic compound (VOC), toluene, using catalytic combustion technology, temperature swing adsorption method (TSA) and electrically heated catalyst system (EHC). Catalytic burner was designed to adopt a duplication of forced diffusion combustion and premixed combustion. Low concentration VOC was accumulated to reach more than

Sung Kyu Kang; Min Woong Ryoo; In Soo Ryu; Sung June Cho; Kwang Sup Song; Yong Seog Seo

1999-01-01

152

Cost effectiveness of silent discharge plasma for point-of-use VOC emissions control in semiconductor fabrication  

SciTech Connect

Extensive research into the treatment and control of Volatile Organic Compounds (VOCs) from semiconductor industry manufacturing processes has identified the need for alternatives to existing combustion devices. Specifically, semiconductor manufacturing design is moving toward the application of effective, small-scale, abatement control technologies for specific point-of-use (POU) waste streams associated with a particular component or manufacturing tool. The consortium of companies involved in semiconductor precompetitive research and development known collectively as SEMATECH recently evaluated eleven emerging environmental technologies designed to treat POU process emissions of VOCs specific to the semiconductor industry. After rigorous technical review only one technology, the Silent Discharge Plasma (SDP) developed at Low Alamos National Laboratory, was considered to successfully meet the required technical performance standards and potential cost effectiveness necessary for continued consideration by SEMATECH in their point-of-use emissions control plans.

Cummings, M.; Booth, S.R.

1996-12-11

153

Assessment of the strategies for reducing VOCs emission from polyurea-formaldehyde resin synthetic fiber leather industry in Taiwan  

Microsoft Academic Search

This study provides a novel attempt to assess the effectiveness of control strategies for reducing volatile organic compounds (VOCs) emission from polyurea-formaldehyde resin synthetic fiber leather (PU) industry. Dimethyl formamide (DMF), major content of solvents, accounts for roughly 2500tonnes\\/year to avoid excessive viscosity of polyurea-formaldehyde and to increase facility in working. The other solvent contents, methyl ethyl ketone (MEK) and

Chang-Tang Chang; Kae-Long Lin

2006-01-01

154

Characterization of Volatile Organic Compounds (VOCs) and Their Sources in the Air of Izmir, Turkey  

Microsoft Academic Search

Air samples were collected in Izmir, Turkey at two (suburban and urban) sites during three sampling programs in 2002 and 2004\\u000a to determine the ambient concentrations of several monoaromatic, chlorinated and oxygenated volatile organic compounds (VOCs).\\u000a Samples were analyzed for 60 VOCs using gas chromatography\\/mass spectrometry and 28 compounds were detected in most samples.\\u000a On the average, urban air VOC

Tolga Elbir; Banu Cetin; Eylem Cetin; Abdurrahman Bayram; Mustafa Odabasi

2007-01-01

155

Mapping methane emission sources over California based on airborne measurements  

NASA Astrophysics Data System (ADS)

The California Global Warming Solutions Act of 2006 (AB 32) has created a need to accurately characterize the emission sources of various greenhouse gases (GHGs) and verify the existing state GHG inventory. Methane (CH4) is a major GHG with a global warming potential of 20 times that of CO2 and currently constitutes about 6% of the total statewide GHG emissions on a CO2 equivalent basis. Some of the major methane sources in the state are area sources where methane is biologically produced (e.g. dairies, landfills and waste treatment plants) making bottom-up estimation of emissions a complex process. Other potential sources include fugitive emissions from oil extraction processes and natural gas distribution network, emissions from which are not well-quantified. The lack of adequate field measurement data to verify the inventory and provide independently generated estimates further contributes to the overall uncertainty in the CH4 inventory. In order to gain a better perspective of spatial distribution of major CH4 sources in California, a real-time measurement instrument based on Cavity Ring Down Spectroscopy (CRDS) was installed in a Twin Otter aircraft for the CABERNET (California Airborne BVOC Emissions Research in Natural Ecosystems Transects) campaign, where the driving research goal was to understand the spatial distribution of biogenic VOC emissions. The campaign took place in June 2011 and encompassed over forty hours of airborne CH4 and CO2 measurements during eight unique flights which covered much of the Central Valley and its eastern edge, the Sacramento-San Joaquin delta and the coastal range. The coincident VOC measurements, obtained through a high frequency proton transfer reaction mass spectrometer (PTRMS), aid in CH4 source identification. High mixing ratios of CH4 (> 2000 ppb) are observed consistently in all the flight transects above the Central Valley. These high levels of CH4 are accompanied by high levels of methanol which is an important dairy tracer. The elevated CH4 mixing ratios, along the eastern edge of the San Joaquin valley, highlight the contribution of local meteorology, topography and emissions transport to local ambient levels of CH4. High mixing ratios of CH4, along with high levels of benzene and toluene, are observed while flying along the western edge of Kern County which is home to some of the largest active oil fields in the state. The scale of these operations and their contribution of < 3% to the state CH4 inventory suggest there is a likelihood of under-estimation of fugitive emissions from oil and gas extraction processes. VOC tracer analysis is used to evaluate the source of high CH4 emissions encountered along the eastern edge of the central Sacramento valley where fugitive emissions from natural gas fields and cultivation of rice are likely sources. Enhancement ratios of CH4 to CO2 and other VOC tracers are compared to existing emission factors from ground based measurements, dairy chamber studies, previous airplane measurements and inventory data.

Karl, T.; Guha, A.; Peischl, J.; Misztal, P. K.; Jonsson, H.; Goldstein, A. H.; Ryerson, T. B.

2011-12-01

156

Volatile organic compound emission factors from roadside measurements  

Microsoft Academic Search

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

Hiroto Kawashima; Shigeki Minami; Yoshimichi Hanai; Akihiro Fushimi

2006-01-01

157

[Characteristics of volatile organic compounds (VOCs) emitted from biofuel combustion in China].  

PubMed

Biofuel combustion is an important source of VOCs in China. Measurements were conducted to determine the characteristics of VOCs emitted from combustion of 5 typical biofuels. A carbon mass balance method was used to determine VOCs emission factors. The emission factors of the total VOCs from agricultural residues and wood combustion are (4.37 +/- 2.23) g x kg(-1) and (2.12 +/- 0.77) g x kg(-1), respectively. The emission factors of the agricultural residues are higher than those of the wood. Aromatics and aldehydes dominate the VOC emissions, both accounting for over 25% of the total VOC emissions. Distribution of VOC components from agricultural residues and wood combustion are similar, except for halogenated hydrocarbons and nitriles. On the basis of measured emission factors and the published maximum incremental reactivity values for VOCs, the ozone forming potential (OFPs) of speciated VOCs is estimated. The results indicate that the average OFPs of the total VOCs from agricultural residues and wood combustion are (16.9 +/- 8.2) g x kg(-1) and (10.8 +/- 4.9) g x kg(-1), respectively. The components with the highest OFPs values are: aldehydes, aromatics and alkenes/alkynes. Aldehydes accounts for over 50% of the total OFPs. PMID:22468511

Li, Xing-Hua; Wang, Shu-Xiao; Hao, Ji-Ming

2011-12-01

158

SOURCES OF COPPER AIR EMISSIONS  

EPA Science Inventory

The report gives results of a study to update estimates of atmospheric emissions of copper and copper compounds in the U.S. Source categories evaluated included: metallic minerals, primary copper smelters, iron and steel making, combustion, municipal incineration, secondary coppe...

159

ASSESSMENT OF NEUROBEHAVIORAL RESPONSE IN HUMANS TO LOW-LEVEL VOLATILE ORGANIC COMPOUND (VOC) SOURCES  

EPA Science Inventory

Occupants of sick buildings often complain of CNS symptoms including headache and memory loss, but little objective evidence of neurobehavioral effects exists. vailable evidence of neurobehavioral effects of low level VOC exposure representative of new buildings is reviewed. etho...

160

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....

161

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....

162

Quantifying fugitive emission of VOCs using the Solar Occultation Flux technique (SOF)  

Microsoft Academic Search

Detection limits down to 0.5 mg?m2 can be achieved which corresponds to measuring a point source of 0.5 kg?h-1 at a distance of 50 m with a precision better than 3%. Trace gas experiments show that an accuracy of 3-5% may be obtained under favorable conditions with emissions from a single point at an open field. This applies under the

Johan Mellqvist

163

A CFD modeling study of the impacts of NOx and VOC emissions on reactive pollutant dispersion in and above a street canyon  

NASA Astrophysics Data System (ADS)

A computational fluid dynamics (CFD) model that includes the carbon bond mechanism IV (CBM-IV) is developed and used to investigate reactive pollutant dispersion in and above a street canyon with an aspect ratio of 1. Fourteen emission scenarios of NOx and volatile organic compounds (VOCs) are considered. Dispersion types are classified into NO-type, NO2-type, and O3-type dispersion that exhibit concentration maxima at the street bottom, near the center of the street canyon, and above the street canyon, respectively. For the base emission scenario, the number of reactive species is 9 in the NO-type dispersion, 10 in the NO2-type dispersion, and 15 in the O3-type dispersion. As the NOx emission level decreases or the VOC emission level increases, some species in the O3-type dispersion are shifted to the NO2-type dispersion. The VOC-to-NOx emission ratio is found to be an important factor in determining the transition of dispersion type. In this transition process, OH plays a key role through a radical chain including HO2, RO, and RO2. Because of their high OH reactivities, XYL (xylene) and OLE (olefin carbon bond) among VOCs are largely responsible for the transition of dispersion type. The O3 sensitivity is examined by reducing NOx or VOC emission level by a half. Because the NO titration of O3 is more pronounced than the NO2 photolysis and the radical chain process in the street canyon, the O3 concentration therein is negatively correlated with the NOx emission level and weakly correlated with the VOC emission level. As a result, the street canyon is a negatively NOx-sensitive regime.

Kwak, Kyung-Hwan; Baik, Jong-Jin

2012-01-01

164

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

Microsoft Academic Search

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

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

165

[Study on control and management for industrial volatile organic compounds (VOCs) in China].  

PubMed

Volatile organic compounds (VOCs) emitted from industrial sources account for a large percent of total anthropogenic VOCs. In this paper, VOCs emission characterization, control technologies and management were discussed. VOCs from industrial emissions were characterized by high intensity, wide range and uneven distribution, which focused on Bejing-Tianjin Joint Belt, Shangdong Peninsula, Yangtze River Delta and the Pearl River Delta. The current technologies for VOCs treatment include adsorption, catalytic combustion, bio-degradation and others, which were applied in petrochemical, oil vapor recovery, shipbuilding, printing, pharmaceutical, feather manufacturing and so on. The scarcity of related regulations/standards plus ineffective supervision make the VOCs management difficult. Therefore, it is suggested that VOCs treatment be firstly performed from key areas and industries, and then carried out step by step. By establishing of actual reducing amount control system and more detailed VOCs emission standards and regulations, applying practical technologies together with demonstration projects, and setting up VOCs emission registration and classification-related-charge system, VOCs could be reduced effectively. PMID:22468504

Wang, Hai-Lin; Zhang, Guo-Ning; Nei, Lei; Wang, Yu-Fei; Hao, Zheng-Ping

2011-12-01

166

Applicability of gasoline containing ethanol as Thailand's alternative fuel to curb toxic VOC pollutants from automobile emission  

NASA Astrophysics Data System (ADS)

Emission rates of benzene, toluene, m-xylene, formaldehyde and acetaldehyde were measured in a fleet of 16 in-use vehicles. The test was performed on a chassis dynamometer incorporated with Bangkok Driving Cycle test mode. Three different test fuels: unleaded gasoline, gasoline blended with 10% ethanol (E10) and gasoline blended with 15% ethanol (E15) were used to determine the different compositions of exhaust emissions from various vehicles. The effects of ethanol content fuels on emissions were tested by three types of vehicles: cars with no catalytic converter installation, cars with three-way catalytic converter and cars with dual-bed catalytic converter. The test result showed wide variations in the average emission rates with different mileages, fuel types and catalytic converters (benzene: 3.33-56.48 mg/km, toluene: 8.62-124.66 mg/km, m-xylene: 2.97-51.65 mg/km, formaldehyde: 20.82-477.57 mg/km and acetaldehyde: 9.46-219.86 mg/km). There was a modest reduction in emission rate of benzene, toluene and m-xylene in cars using E10 and E15 fuels. Use of ethanol fuels, however, leads to increased formaldehyde and acetaldehyde emission rates. Our analysis revealed that alternative fuels and technologies give significant reduction in toxic VOC pollutants from automobile emission—particularly car with dual-bed catalytic converter using E10 fuel.

Leong, Shing Tet; Muttamara, S.; Laortanakul, Preecha

167

Reduction of VOC emissions by a membrane-based gas absorption process.  

PubMed

A membrane-based gas absorption (MGA) process was evaluated for the removal of volatile organic compounds (VOCs) based on C6H6/N2 mixture. The absorption of C6H6 from a C6H6/N2 mixture was investigated using a hydrophobic polypropylene hollow fiber membrane contactor and the aqueous solution of N-formyl morpholine (NFM) as absorbent. The effects of various factors on the overall mass transfer coefficient was investigated. The experimental results showed that the removal efficiency of C6H6 could reach 99.5% in present studied system. A mathematical model based on resistance-in-series concept was presented to predict the value of overall mass transfer coefficient. The average error between the predicted and experimental values is 7.9%. In addition, conventional packed columns for VOCs removal was also evaluated for comparison. PMID:19862923

Li, Rui; Xu, Jun; Wang, Lianjun; Li, Jiansheng; Sun, Xiuyun

2009-01-01

168

Evaluation of a novel assay of potential toxicity\\/neurotoxicity of carpet emissions (VOCs) in mice  

Microsoft Academic Search

A private testing laboratory utilizing the whole-body plethysmograph\\/head-only exposure apparatus outlined in the respiratory irritation assay ASTM E981-84, along with a novel exposure regimen, has reported neurotoxic effects and mortality in mice exposed to relatively low levels of volatile organic compounds (VOCs) emitted from a number of consumer products. This methodology was evaluated by exposing groups of mice, including unrestrained

W. T. Stott; M. J. Beekman; K. A. Johnson; P. J. Spencer

1997-01-01

169

Mobile source hazardous air pollutant emissions in the Seattle-Tacoma urban area. Report for February 1993-November 1994  

SciTech Connect

This paper describes mobile source hazardous air pollutant (HAP) emissions in the Seattle-Tacoma, Washington, urban area. Included in this inventory are mobile source emissions from both on-road (e.g., highway vehicles) and non-road (e.g., agricultural equipment) mobile sources. These mobile source emission estimates, summarized in this paper, were developed based on volatile organic compound (VOC) emissions and activity level data from the Seattle-Tacoma 1990 base year State Implementation Plan (SIP) emission inventory. The contribution of mobile source HAP emissions was compared to that of stationary area sources in the Seattle-Tacoma area. Mobile sources contributed about 83% of the benzene, 74% of the formaldehyde, and 88% of the 1,3-butadiene emissions.

Mangino, J.; Jones, J.W.

1994-12-31

170

Global comparison of VOC and CO observations in urban areas  

NASA Astrophysics Data System (ADS)

Speciated volatile organic compound (VOC) and carbon monoxide (CO) measurements from the Marylebone Road site in central London from 1998 through 2008 are presented. Long-term trends show statistically significant decreases for all the VOCs considered, ranging from -3% to -26% per year. Carbon monoxide decreased by -12% per year over the measurement period. The VOC trends observed at the kerbside site in London showed greater rates of decline relative to trends from monitoring sites in rural England (Harwell) and a remote high-altitude site (Hohenpeissenberg), which showed decreases for individual VOCs from -2% to -13% per year. Over the same 1998 through 2008 period VOC to CO ratios for London remained steady, an indication that emissions reduction measures affected the measured compounds equally. Relative trends comparing VOC to CO ratios between Marylebone Road and Hohenpeissenberg showed greater similarities than absolute trends, indicating that emissions reductions measures in urban areas are reflected by regional background locations. A comparison of VOC mixing ratios and VOC to CO ratios was undertaken for London and other global cities. Carbon monoxide and VOCs (alkanes greater than C 5, alkenes, and aromatics) were found to be strongly correlated (>0.8) in the Annex I countries, whereas only ethene and ethyne were strongly correlated with CO in the non-Annex I countries. The correlation results indicate significant emissions from traffic-related sources in Annex I countries, and a much larger influence of other sources, such as industry and LPG-related sources in non-Annex I countries. Yearly benzene to ethyne ratios for London from 2000 to 2008 ranged from 0.17 to 0.29 and compared well with previous results from US cities and three global megacities.

von Schneidemesser, Erika; Monks, Paul S.; Plass-Duelmer, Christian

2010-12-01

171

The reduction of formaldehyde and VOCs emission from wood-based flooring by green adhesive using cashew nut shell liquid (CNSL).  

PubMed

To discuss the reduction of formaldehyde and volatile organic compound (VOC) emissions from engineered flooring, cashew nut shell liquid (CNSL)-formaldehyde (CF) resin and CF/PVAc resin were applied for the maple face of the veneer bonding on plywood. The CF resin was used to replace urea-formaldehyde (UF) resin in the formaldehyde-based resin system in order to reduce formaldehyde and VOC emissions from the adhesives used between the plywoods and fancy veneers. For the CF/PVAc resins, 5, 10, 20 or 30% of PVAc was added to the CF resin. The CF/PVAc resins showed better bonding than the commercial natural tannin adhesive with a higher level of wood penetration. The standard formaldehyde emission test and a VOC analyzer were used to determine the formaldehyde and VOC emissions, respectively, from the engineered floorings. The CF resin and CF/PVAc resin systems with UV coating satisfied the E(1) and E(0) grades of the Korean Standard. TVOC emission was slightly increased by the PVAc addition. PMID:20362392

Kim, Sumin

2010-03-07

172

PAHs, carbonyls, VOCs and PM2.5 emission factors for pre-harvest burning of Florida sugarcane  

NASA Astrophysics Data System (ADS)

Emission factors (EFs) for hazardous polycyclic aromatic hydrocarbons (PAHs), carbonyls, and volatile organic compounds (VOCs) as well as other species such as PM2.5, elemental carbon (EC), organic carbon (OC), and tracer compounds (e.g., levoglucosan (LG) and other sugars) were investigated for sugarcane pre-harvest burning in Florida. A combustion chamber was used to simulate field burning conditions for determining EFs of both dry leaf and whole stalk biomass burning. Samples were collected from the chamber's exhaust duct following EPA sampling methods. The total PAH EFs were 7.13 ± 0.94 and 8.18 ± 3.26 mg kg-1 for dry leaf and whole sugarcane stalk burning, respectively. Carbonyl EFs were 201 ± 39 and 942 ± 539 mg kg-1 for dry leaf and whole stalk burning, respectively. PAH and carbonyl emissions were dominated by lower molecular weight compounds (e.g., naphthalene and formaldehyde, respectively). Of the aromatic VOCs studied, benzene was the predominant species. The PM2.5 EF was 2.49 ± 0.66 g kg-1, which is in range of the current published AP-42 EFs for particulate matter emissions from sugarcane burning and other sugarcane studies. The OC, EC and LG EFs were 0.16 ± 0.09 g kg-1, 0.71 ± 0.22 g kg-1, and 7.87 ± 5.42 mg kg-1, respectively. EFs of gaseous pollutants were generally lower than EFs from studies of agricultural residue combustion, likely due to the high combustion efficiency observed in this study.

Hall, Danielle; Wu, Chang-Yu; Hsu, Yu-Mei; Stormer, James; Engling, Guenter; Capeto, Krisha; Wang, Jun; Brown, Scott; Li, Hsing-Wang; Yu, Kuei-Min

2012-08-01

173

Minor Sources Of Air Pollutant Emissions  

Microsoft Academic Search

Emission source inventories for air pollutants have considered major categories such as transportation, domestic heating, electric power generation, refuse burning, industrial fuel consumption and process emissions, as well as commercial, institutional, and governmental space heat fuel burning. Not considered in such emission inventories are sources such as aerosol spray cans, ground dust, leaf burning, cosmic dust, crop dusting, perfumes, smoking,

Vincent J. Marchesani; Thomas Towers; Henry C. Wohlers

1970-01-01

174

Control of VOC emissions from natural gas pipeline compressor station engines. Topical report, June 1990January 1991  

Microsoft Academic Search

The objective of the study was to develop information in support of the following areas: VOC control technology review for compressor station prime movers; Assessment of VOC\\/NOx control tradeoff for natural gas compressor stations. The major emphasis of the study was in the first area--VOC control technology review. In the second part of the study, Acurex was tasked to provide

1991-01-01

175

VOC Destruction by Catalytic Combustion Microturbine  

SciTech Connect

This project concerned the application of a catalytic combustion system that has been married to a micro-turbine device. The catalytic combustion system decomposes the VOC's and transmits these gases to the gas turbine. The turbine has been altered to operate on very low-level BTU fuels equivalent to 1.5% methane in air. The performance of the micro-turbine for VOC elimination has some flexibility with respect to operating conditions, and the system is adaptable to multiple industrial applications. The VOC source that was been chosen for examination was the emissions from coal upgrading operations. The overall goal of the project was to examine the effectiveness of a catalytic combustion based system for elimination of VOCs while simultaneously producing electrical power for local consumption. Project specific objectives included assessment of the feasibility for using a Flex-Microturbine that generates power from natural gas while it consumes VOCs generated from site operations; development of an engineering plan for installation of the Flex-Microturbine system; operation of the micro-turbine through various changes in site and operation conditions; measurement of the VOC destruction quantitatively; and determination of the required improvements for further studies. The micro-turbine with the catalytic bed worked effectively to produce power on levels of fuel much lower than the original turbine design. The ability of the device to add or subtract supplemental fuel to augment the amount of VOC's in the inlet air flow made the device an effective replacement for a traditional flare. Concerns about particulates in the inlet flow and the presence of high sulfur concentrations with the VOC mixtures was identified as a drawback with the current catalytic design. A new microturbine design was developed based on this research that incorporates a thermal oxidizer in place of the catalytic bed for applications where particulates or contamination would limit the lifetime of the catalytic bed.

Tom Barton

2009-03-10

176

Source Assessment: Acrylonitrile Manufacture (Air Emissions).  

National Technical Information Service (NTIS)

The report gives results of an analysis of atmospheric emissions from propylene-based acrylonitrile manufacturing plants. Uncontrolled and controlled emission factors are given for each species emitted to the atmosphere from each source within a typical p...

T. W. Hughes D. A. Horn

1977-01-01

177

Towards constraining sources of Unexplored VOC and their oxidation products in the forest environments  

NASA Astrophysics Data System (ADS)

Unexplored BVOC and their oxidation products have been suspected as a main source of uncertainty for understanding tropospheric photochemical chemistry, controlling ozone and secondary organic aerosol formation on regional and global scales. For this reason, many studies have assessed the abundance of unexplored BVOC. One of the most effective ways to quantify unexplored BVOC is to compare measured and calculated OH reactivity. Previous measurements in various forest environments have consistently indicated that significant fractions of measured OH reactivity could not be explained by measured BVOC and their oxidation products. Any unaccounted OH reactivity is conventionally called “missing OH reactivity”. There is still controversy about the origins of missing OH reactivity; for example whether it is coming from unexplored BVOC emissions or unexplored oxidation products from known BVOC. To constrain the potential sources, we conducted branch enclosure OH reactivity measurements at the PROPHET site (Pellston, MI USA) for four different dominant tree species in the ecosystem during the CABINEX field campaign in 2009. We will discuss our results in the context of unexplored primary BVOC emissions and possible contributions of unmeasured oxidation products of known BVOC such as isoprene. For comparison, we will also present preliminary OH reactivity measurement results (both enclosure and ambient) from 232-MBO dominated ecosystems (Woodland Park, CO) during the BEACHON-ROCS field campaign in the summer of 2010.

Kim, S.; Guenther, A. B.; Karl, T.; Greenberg, J.; Harley, P. C.

2010-12-01

178

Select the best VOC control strategy  

Microsoft Academic Search

Volatile organic compounds (VOCs) are among the most common pollutants emitted by the chemical process industries (CPI). Accordingly, VOC emission control is a major portion of the CPI's environmental activities. Reduction of VOC emissions in areas that exceed the current national ambient air quality standard for ozone of 0.12 ppm is mandated under Title I of the Clean Air Act

E. N. Ruddy; L. A. Carroll

1993-01-01

179

National Emissions Inventory of Sources and Emissions of Silver.  

National Technical Information Service (NTIS)

A national inventory of the sources and emissions of the element silver was conducted. The study included the preparation of an overall material flow chart depicting the quantities of silver moving from sources of mining and importation through all proces...

1973-01-01

180

Determinants of personal, indoor and outdoor VOC concentrations: An analysis of the RIOPA data.  

PubMed

Community and environmental exposure to volatile organic compounds (VOCs) has been associated with a number of emission sources and activities, e.g., environmental tobacco smoke and pumping gasoline. Such factors have been identified from mostly small studies with relatively limited information regarding influences on VOC levels. This study uses data from the Relationship of Indoor Outdoor and Personal Air (RIOPA) study to investigate environmental, individual and social determinants of VOC concentrations. RIOPA included outdoor, indoor and personal measurements of 18 VOCs from 310 non-smoking households and adults in three cities and two seasons, and collected a wide range of information pertaining to participants, family members, households, and neighborhoods. Exposure determinants were identified using stepwise regressions and linear mixed-effect models. Most VOC exposure (66 to 78% of the total exposure, depending on VOC) occurred indoors, and outdoor VOC sources accounted for 5 (d-limonene) to 81% (carbon tetrachloride) of the total exposure. Personal exposure and indoor measurements had similar determinants, which depended on the VOC. Gasoline-related VOCs (e.g., benzene, methyl tertiary butyl ether) were associated with city, residences with attached garages, self-pumping of gas, wind speed, and house air exchange rate (AER). Odorant and cleaning-related VOCs (e.g., 1,4-dichlorobenzene and chloroform) also were associated with city and AER, and with house size and family members showering. Dry-cleaning and industry-related VOCs (e.g., tetrachloroethylene and trichloroethylene) were associated with city, residence water supply type, and dry-cleaner visits. These and other relationships were significant, explained from 10 to 40% of the variation, and are consistent with known emission sources and the literature. Outdoor concentrations had only two common determinants: city and wind speed. Overall, personal exposure was dominated by the home setting, although a large fraction of VOC concentrations were due to outdoor sources. City, personal activities, household characteristics and meteorology were significant determinants. PMID:24034784

Su, Feng-Chiao; Mukherjee, Bhramar; Batterman, Stuart

2013-09-10

181

75 FR 19252 - Delegation of New Source Performance Standards and National Emission Standards for Hazardous Air...  

Federal Register 2010, 2011, 2012, 2013

...Petroleum Yes. Refinery Wastewater Systems. RRR............... VOC Emissions from SOCMI Reactor Yes. Processes. SSS............... Magnetic Tape Coating Operations Yes. TTT............... Industrial Surface...

2010-04-14

182

Forest-atmosphere exchange of ozone: sensitivity to very reactive biogenic VOC emissions and implications for in-canopy photochemistry  

NASA Astrophysics Data System (ADS)

Understanding the fate of ozone within and above forested environments is vital to assessing the anthropogenic impact on ecosystems and air quality at the urban-rural interface. Observed forest-atmosphere exchange of ozone is often much faster than explicable by stomatal uptake alone, suggesting the presence of additional ozone sinks within the canopy. Using the Chemistry of Atmosphere-Forest Exchange (CAFE) model in conjunction with summer noontime observations from the 2007 Biosphere Effects on Aerosols and Photochemistry Experiment (BEARPEX-2007), we explore the viability and implications of the hypothesis that ozonolysis of very reactive but yet unidentified biogenic volatile organic compounds (BVOC) can influence the forest-atmosphere exchange of ozone. Non-stomatal processes typically generate 67 % of the observed ozone flux, but reactions of ozone with measured BVOC, including monoterpenes and sesquiterpenes, can account for only 2 % of this flux during the selected timeframe. By incorporating additional emissions and chemistry of a proxy for very reactive VOC (VRVOC) that undergo rapid ozonolysis, we demonstrate that an in-canopy chemical ozone sink of ~2 × 108 molec cm-3 s-1 can close the ozone flux budget. Even in such a case, the 65 min chemical lifetime of ozone is much longer than the canopy residence time of ~2 min, highlighting that chemistry can influence reactive trace gas exchange even when it is "slow" relative to vertical mixing. This level of VRVOC ozonolysis could enhance OH and RO2 production by as much as 1 pptv s-1 and substantially alter their respective vertical profiles depending on the actual product yields. Reaction products would also contribute significantly to the oxidized VOC budget and, by extension, secondary organic aerosol mass. Given the potentially significant ramifications of a chemical ozone flux for both in-canopy chemistry and estimates of ozone deposition, future efforts should focus on quantifying both ozone reactivity and non-stomatal (e.g. cuticular) deposition within the forest.

Wolfe, G. M.; Thornton, J. A.; McKay, M.; Goldstein, A. H.

2011-08-01

183

Forest-atmosphere exchange of ozone: sensitivity to very reactive biogenic VOC emissions and implications for in-canopy photochemistry  

NASA Astrophysics Data System (ADS)

Understanding the fate of ozone within and above forested environments is vital to assessing the anthropogenic impact on ecosystems and air quality at the urban-rural interface. Observed forest-atmosphere exchange of ozone is often much faster than explicable by stomatal uptake alone, suggesting the presence of additional ozone sinks within the canopy. Using the Chemistry of Atmosphere-Forest Exchange (CAFE) model in conjunction with summer noontime observations from the 2007 Biosphere Effects on Aerosols and Photochemistry Experiment (BEARPEX-2007), we explore the viability and implications of the hypothesis that ozonolysis of very reactive but yet unidentified biogenic volatile organic compounds (BVOC) can influence the forest-atmosphere exchange of ozone. Non-stomatal processes typically generate 67% of the observed ozone flux, but reactions of ozone with measured BVOC, including monoterpenes and sesquiterpenes, can account for only 2% of this flux during the selected timeframe. By incorporating additional emissions and chemistry of a proxy for very reactive VOC (VRVOC) that undergo rapid ozonolysis, we demonstrate that an in-canopy chemical ozone sink of ~2×108 molecules cm-3 s-1 can close the ozone flux budget. Even in such a case, the 65 min chemical lifetime of ozone is much longer than the canopy residence time of ~2 min, highlighting that chemistry can influence reactive trace gas exchange even when it is "slow" relative to vertical mixing. This level of VRVOC ozonolysis could enhance OH and RO2 production by as much as 1 pptv s-1 and substantially alter their respective vertical profiles depending on the actual product yields. Reaction products would also contribute significantly to the oxidized VOC budget and, by extension, secondary organic aerosol mass. Given the potentially significant ramifications of a chemical ozone flux for both in-canopy chemistry and estimates of ozone deposition, future efforts should focus on quantifying both ozone reactivity and non-stomatal (e.g. cuticular) deposition within the forest.

Wolfe, G. M.; Thornton, J. A.; McKay, M.; Goldstein, A. H.

2011-05-01

184

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

NASA Astrophysics Data System (ADS)

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

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

2009-12-01

185

Emissions of VOCs at Urban Petrol Retail Distribution Centres in India (Delhi and Mumbai)  

Microsoft Academic Search

Air pollution has assumed gigantic proportion killing almost half a million Asians every year. Urban pollution mainly comprises of emissions from buses, trucks, motorcycle other forms of motorized transport and its supporting activities. As Asia's cities continue to expand the number of vehicles have risen resulting in greater pollution. Fugitive emissions from retail distribution center in urban area constitute a

Anjali Srivastava; A. E. Joseph; Ajit More; Sunil Patil

2005-01-01

186

The impact of NO x , CO and VOC emissions on the air quality of Zurich airport  

Microsoft Academic Search

To study the impact of emissions at an airport on local air quality, a measurement campaign at the Zurich airport was performed from 30 June 2004 to 15 July 2004. Measurements of NO, NO2, CO and CO2 were conducted with open path devices to determine real in-use emission indices of aircraft during idling. Additionally, air samples were taken to analyse

Gregor Schürmann; Klaus Schäfer; Carsten Jahn; Herbert Hoffmann; Martina Bauerfeind; Emanuel Fleuti; Bernhard Rappenglück

2007-01-01

187

Factors controlling natural VOC emissions in a southeastern US pine forest  

Microsoft Academic Search

A one-year field study was conducted to investigate the control factors of the monoterpene emissions from slash and loblolly pine saplings at the Austin Cary Forest site in Florida. The ?-pinene, camphene, ?-pinene, myrcene, d-limonene, and ?-phellandrene were identified in the emission samples collected from native pine trees. The ?-pinene was the principal (>60%) monoterpene emitted by both slash and

Jo-Chun Kim

2001-01-01

188

VOCs in industrial, urban and suburban neighborhoods, Part 1: Indoor and outdoor concentrations, variation, and risk drivers  

Microsoft Academic Search

Information regarding indoor and ambient concentrations and exposures of volatile organic compounds (VOCs) is limited in terms of the number and types of compounds measured, the spatial and temporal variation of concentrations, and the significance of indoor and outdoor emission sources. This study characterizes a wide range of VOCs across three communities that represent a gradient of population density and

Chunrong Jia; Stuart Batterman; Christopher Godwin

2008-01-01

189

Eddy flux and leaf-level measurements of biogenic VOC emissions from mopane woodland of Botswana  

NASA Astrophysics Data System (ADS)

Biogenic volatile organic compound (BVOC) emissions were measured in a mopane woodland near Maun, Botswana in January-February 2001 as part of SAFARI 2000. This landscape is comprised of more than 95% of one woody plant species, Colophospermum mopane (Caesalpinaceae). Mopane woodlands extend over a broad area of southern Africa. A leaf cuvette technique was used to determine the emission capacities of the major vegetation and the temperature and light dependence of the emissions. In addition, relaxed eddy accumulation (REA) measurements of BVOC fluxes were made on a flux tower, where net CO2 emissions were also measured simultaneously. Large light-dependent emissions of terpenes (mostly ?-pinene and D-limonene) were observed from the mopane woodland. The diurnal BVOC emissions were integrated and compared with the CO2 flux. Monoterpene flux exceeded 3000 ?g C m-2 h-1 during the daytime period, comparable to isoprene fluxes and much higher than terpene fluxes measured in most areas. The terpene flux constituted approximately 25% of the diurnal net carbon exchange (CO2) during the experimental period. Other BVOC emissions may also contribute to the carbon exchange.

Greenberg, J. P.; Guenther, A.; Harley, P.; Otter, L.; Veenendaal, E. M.; Hewitt, C. N.; James, A. E.; Owen, S. M.

2003-07-01

190

A survey of California plant species with a portable VOC analyzer for biogenic emission inventory development  

NASA Astrophysics Data System (ADS)

An accurate estimate of the magnitude of biogenic volatile organic compound (BVOC) emissions in California's airsheds is critical for formulating effective strategies to reduce concentrations of fine particles, ozone, and other secondary air pollutants which affect human health and reduce yields of agricultural crops. However, California's natural and urban landscapes contain more than 6000 species, and the BVOC emissions from only a small fraction of these species have been characterized by quantitative measurements. A taxonomic method has been proposed to assign BVOC emission rate measurements to unmeasured species, but data are needed for additional plant families and genera to further develop and test this taxonomic approach. In the present study, BVOC emissions from more than 250 plant species were measured through a semi-quantitative method employing calibrated portable analyzers with photoionization detectors (PID). Replicate samples of live foliage were placed in plastic bags, in both light and darkened conditions, and the BVOC emissions categorized as low, medium or high. To validate our approach, for 63 plant species we compared our PID-measured BVOC emissions with published values, based on gas chromatography (GC) or GC-mass spectrometry, and found them to be well correlated. The method employed was more suited for detecting compounds with relatively higher emission rates, such as isoprene, than compounds with low emission rates, which could include monoterpenes and oxygenated compounds. For approximately 200 plant species not previously measured, the results provide further evidence that plant taxonomy can serve as a useful guide for generalizing the emissions behavior of many, but not all, plant families and genera.

Karlik, John F.; McKay, Alistair H.; Welch, Jason M.; Winer, Arthur M.

191

Putting the heat on VOCs  

Microsoft Academic Search

A tried-and-true technology for VOC control is oxidation, either catalytic or thermal. Oxidation units can destroy nearly 75 percent of the VOC and toxic emissions targeted by the Clean Air Act Amendments (CAAA) of 1990. In fact, the Hazardous Organic NESHAP (HON) rule finalized last year for synthetic chemical processors specified combustion devices as a technology of choice for treating

Cloud

1995-01-01

192

[Investigation on emission properties of biogenic VOCs of landscape plants in Shenzhen].  

PubMed

Isoprene and monoterpene emissions were characterized using flow and enclosure sampling method and GC-MS in USA for 158 species of plants growing in Shenzhen, China. This survey was designed to include all of the dominant plants within the Shenzhen region as well as unique plants such as Cycads. These are the first measurements in a subtropical Asian metropolis. Substantial isoprene emissions were observed from thirty-one species, including Caryota mitis, Adenanthera pavonina var. microsperma, Mangifera indica and Excoecoria agalloch. Monoterpene emissions were observed from fifty-two species, including Passiflora edulis, Bambusa glaucescens cv. silverstripe as well as some primitive and rare Cycadaceae and Cyatheaceae plants. For the first time some of red plants have been measured, most of them have the ability of releasing terpene. These results will be used to develop biogenic emission model estimates for Shenzhen and the surrounding region that can be used as inputs for regional air quality models. PMID:22468517

Huang, Ai-Kui; Li, Nan; Guenther, Alex; Greenberg, Jim; Baker, Brad; Graessli, Michael; Bai, Jian-Hui

2011-12-01

193

Temperature and air velocity effects on ethanol emission from corn silage  

Technology Transfer Automated Retrieval System (TEKTRAN)

Volatile organic compounds (VOCs) from agricultural sources are believed to be an important contributor to tropospheric ozone in some areas. Recent research suggests that silage is a major source of these VOCs, but only limited data exist on VOC emission from silage. Ethanol is normally the most abu...

194

Reconciling bottom-up, top-down, and direct measurements of biogenic VOC emissions  

NASA Astrophysics Data System (ADS)

Biogenic Volatile Organic compound (BVOC) emissions vary considerably on spatial scales ranging from a few meters to thousands of kilometers and temporal scales ranging from seconds to years. Accurate estimates of BVOC emissions are required for many regional air quality modeling studies and global earth system investigations. We compare results from bottom-up estimates, using The Model of Emissions of Gases and Aerosols from Nature (MEGAN), with top-down estimates, based on satellite and in-situ concentration distributions, and direct flux measurements. We describe examples of both agreement and disagreement in U.S., tropical forest and other landscapes and discuss potential explanations for differences that can exceed a factor of 2. Future measurement and modeling needs are outlined and specific activities are proposed to improve efforts to reconcile these approaches and understand the controlling processes.

Guenther, A.; Karl, T.; Wiedinmyer, C.; Barkley, M.; Palmer, P.; Muller, J. F.; Stavrakov, T.; Millet, D.

2007-12-01

195

SOURCE RECEPTOR STUDY OF VOLATILE ORGANIC COMPOUNDS AND PARTICULATE MATTER IN THE KANAWHA VALLEY, WV - PART II: ANALYSIS OF FACTORS CONTRIBUTING TO VOC AND PARTICLE EXPOSURES  

EPA Science Inventory

The Kanawha Valley region of West Virginia includes a deep river valley with a large population living in close proximity to many potential sources of ambient volatile organics compounds (VOCs). he Valley runs approximately 100 km from Alloy to Nitro and is between 100 and 200 m ...

196

DEVELOPMENT OF TRANSITION METAL OXIDE-ZEOLITE CATALYSTS TO CONTROL CHLORINATED VOC AIR EMISSIONS  

EPA Science Inventory

The paper discusses the development of transition metal oxide (TMO)-zeolite oxidation catalysts to control chlorinated volatile organic compound (CVOC) air emissions. esearch has been initiated to enhance the utility of these catalysts by the development of a sorption-catalyst sy...

197

Parameters Impacting the Emissions of Selected VOCs from the Toner for a Specific Photocopier.  

National Technical Information Service (NTIS)

The paper gives results of the measurement of emission--using a laboratory thermal desorption apparatus--from a number of nominally identical photocopier toners (manufactured for use in a specific model copier) when the toners were heated to fuser tempera...

D. B. Henschel R. C. Fortmann N. F. Roache X. Liu

2000-01-01

198

MEASUREMENT OF VOC EMISSIONS FROM PONDEROSA PINE LUMBER USING COMMERCIAL AND LABORATORY KILNS  

Microsoft Academic Search

The 1990 U.S. Clean Air Act has increased the need to know what is emitted from dryers, but measuring emissions on a commercial scale is difficult and expensive. A laboratory method would allow closer control over the process and allow process variables to be studied with reduced variability and at a lower cost. In this research project, the total hydrocarbon

Mark R. Lavery; Michael R. Milota

2001-01-01

199

Ambient volatile organic compound (VOC) concentrations around a petrochemical complex and a petroleum refinery.  

PubMed

Air samples were collected between September 2000 and September 2001 in Izmir, Turkey at three sampling sites located around a petrochemical complex and an oil refinery to measure ambient volatile organic compound (VOC) concentrations. VOC concentrations were 4-20-fold higher than those measured at a suburban site in Izmir, Turkey. Ethylene dichloride, a leaded gasoline additive used in petroleum refining and an intermediate product of the vinyl chloride process in the petrochemical complex, was the most abundant volatile organic compound, followed by ethyl alcohol and acetone. Evaluations based on wind direction clearly indicated that ambient VOC concentrations measured were affected by the refinery and petrochemical complex emissions. VOC concentrations showed seasonal variations at all sampling sites. Concentrations were highest in summer, followed by autumn, probably due to increased evaporation of VOCs from fugitive sources as a result of higher temperatures. VOC concentrations generally increased with temperature and wind speed. Temperature and wind speed together explained 1-60% of the variability in VOC concentrations. The variability in ambient VOC concentrations that could not be explained by temperature and wind speed can be attributed to the effect of other factors (i.e. wind direction, other VOC sources). PMID:12873403

Cetin, Eylem; Odabasi, Mustafa; Seyfioglu, Remzi

2003-08-01

200

INSTRUMENTAL SENSING OF STATIONARY SOURCE EMISSIONS  

EPA Science Inventory

Remote sensing methods offer a number of advantages over contact measurement methods in the area of enforcement and surveillance of emissions from stationary sources. Several techniques have been developed that can measure the gas concentration, effluent velocity, and particulate...

201

Urban modeling of organic aerosol source emissions.  

National Technical Information Service (NTIS)

A mathematical model was used to predict the characteristics of fine organic aerosol that would be present in the Los Angeles atmosphere if direct organic aerosol source emissions were transported without chemical reaction. The model was successful at tra...

L. M. Hildemann G. R. Cass M. A. Mazurek

1990-01-01

202

Characteristics of Ambient Volatile Organic Compounds (VOCs) Measured in Shanghai, China  

PubMed Central

To better understand the characteristics of ambient abundance of volatile organic compounds (VOCs) in Shanghai, one of the biggest metropolis of China, VOCs were measured with a gas chromatography system equipped with a mass-selective detector (GC/MSD) from July 2006 to February 2010. An intensive measurement campaign was conducted (eight samples per day with a 3 hour interval) during May 2009. The comparison of ambient VOCs collected in different regions of Shanghai shows that the concentrations are slightly higher in the busy commercial area (28.9 ppbv at Xujiaui) than in the urban administrative area (24.3 ppbv at Pudong). However, during the intensive measurement period, the concentrations in the large steel industrial area (28.7 ppbv at Baoshan) were much higher than in the urban administrative area (18 ppbv at Pudong), especially for alkanes, alkenes, and toluene. The seasonal variations of ambient VOC concentrations measured at the Xujiahui sampling site indicate that the VOC concentrations are significantly affected by meteorological conditions (such as wind direction and precipitation). In addition, although alkanes are the most abundant VOCs at the Xujiahui measurement site, the most important VOCs contributing to ozone formation potential (OFP) are aromatics, accounting for 57% of the total OFP. The diurnal variations of VOC concentrations show that VOC concentrations are higher on weekdays than in weekends at the Xujiahui sampling site, suggesting that traffic condition and human activities have important impacts on VOC emissions in Shanghai. The evidence also shows that the major sources of isoprene are mainly resulted from gasoline evaporation at a particular time (06:00–09:00) in the busy commercial area. The results gained from this study provide useful information for better understanding the characteristics of ambient VOCs and the sources of VOCs in Shanghai.

Cai, Chang-Jie; Geng, Fu-Hai; Tie, Xue-Xi; Yu, Qiong; Peng, Li; Zhou, Guang-Qiang

2010-01-01

203

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

PubMed

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

Shin, Seung H; Jo, Wan K

2012-06-12

204

Volatile organic compound emissions from dairy facilities in central California  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

205

Jovian S emission: Model of radiation source  

NASA Astrophysics Data System (ADS)

A physical model of the radiation source and an excitation mechanism have been suggested for the S component in Jupiter's sporadic radio emission. The model provides a unique explanation for most of the interrelated phenomena observed, allowing a consistent interpretation of the emission cone structure, behavior of the integrated radio spectrum, occurrence probability of S bursts, location and size of the radiation source, and fine structure of the dynamic spectra. The mechanism responsible for the S bursts is also discussed in connection with the L type emission. Relations are traced between parameters of the radio emission and geometry of the Io flux tube. Fluctuations in the current amplitude through the tube are estimated, along with the refractive index value and mass density of the plasma near the radiation source.

Ryabov, B. P.

1994-04-01

206

Atomic emission sources for solution spectrochemistry  

Microsoft Academic Search

Atomic emission spectrometry (AES) is used for elemental determinations in various types of samples, many of which are solutions. The most significant development in AES in the past 15 years is the development of the inert gas, electrical discharge plasma excitation source. The author compares inductively coupled plasma, direct-current plasma, and microwave-induced plasma sources. 10 references, 5 figures, 4 tables.

Andrew T. Zander

1986-01-01

207

Estimation of VOCs and semivolatiles emission rate from an intermittently aerated bioreactor  

SciTech Connect

The activated sludge process is widely employed to treat municipal and industrial wastewater. The common design considers a continuous, constant flow-rate wastewater stream and a corresponding continuous air supply. Recently, intermittently aerated bioreactors, such as the sequencing batch reactor (SBR), have found great potential for more efficient wastewater treatment. A transient model considering the emission rate of volatile and semivolatile organic compounds from an intermittently aerated bioreactor is developed and solved analytically. If the aeration time is relatively short, and/or the overall mass transfer resistance is high, a large deviation can occur from the pseudo-steady-state mass transfer model by Chern and Yu or from the conventional ASCE standard model by Matter-Mueller et al.

Liao, Y.C.; Lee, D.J. [National Taiwan Univ., Taipei (Taiwan, Province of China). Dept. of Chemical Engineering

1997-03-01

208

Ethanol emission from loose corn silage  

Technology Transfer Automated Retrieval System (TEKTRAN)

Silage and silage-containing feed on dairy farms have recently been identified as a source of volatile organic compound (VOC) emissions. In this work, we present measurements of ethanol (a dominant silage VOC) emission from loose corn silage samples made using a wind tunnel system. Flux of ethanol f...

209

A corona discharge atmospheric pressure chemical ionization source with selective NO(+) formation and its application for monoaromatic VOC detection.  

PubMed

We have developed a new type of corona discharge (CD) for atmospheric pressure chemical ionization (APCI) for application in ion mobility spectrometry (IMS) as well as in mass spectrometry (MS). While the other CD-APCI sources are able to generate H3O(+)·(H2O)n as the major reactant ions in N2 or in zero air, the present CD-APCI source has the ability to generate up to 84% NO(+)·(H2O)n reactant ions in zero air. The change of the working gas from zero air to N2 allows us to change the major reactant ions from NO(+)·(H2O)n to H3O(+)·(H2O)n. In this paper we present the description of the new CD-APCI and discuss the processes associated with the NO(+) formation. The selective formation of NO(+)·(H2O)n reactant ions offers chemical ionization based on these ions which can be of great advantage for some classes of chemicals. We demonstrate here a significant increase in the sensitivity of the IMS-MS instrument for monoaromatic volatile organic compound (VOC) detection upon NO(+)·(H2O)n chemical ionization. PMID:24081306

Sabo, Martin; Matej?ík, Stefan

2013-10-15

210

CHARACTERIZATION OF VOC EMISSIONS FROM INTERIOR MATERIALS OF RAILROAD PASSENGER CABIN AND PREPARATION OF ENVIRONMENT-FRIENDLY INTERIOR MATERIAL  

Microsoft Academic Search

The indoor air quality of railroad passenger cabin is often polluted by various pollutants. The pollutants sources of the passenger cabin are the passengers with their belongings, the inflowing outdoor air, and the interior materials like floorings, seats, paints, and adhesives. In this study, we focused on the pollutants emissions from the interior materials, and carried out the characterization of

Youngmin Cho; Duck-Shin Park; Soon-Bark Kwon

211

TV picture-tube manufacturer uses regenerative catalytic oxidizer to reduce VOC emissions  

SciTech Connect

Toshiba Display Services, a television picture-tube manufacturer in Horseheads, NY, recently was able to meet stringent state regulations to reduce emissions from two of its film applications lines by installing a regenerative catalytic oxidation system. Toshiba officials initially evaluated several technologies to control volatile organic compounds. After deciding that oxidation was the best technology for its facility, the company invited a number of suppliers to submit proposals. Because all of the oxidation technologies considered by Toshiba had the capability to achieve the destruction and removal efficiency requirement, the company combined the second and third decision elements and conducted an in-depth comparison of the initial capital and ongoing operating costs for each proposal. Officials narrowed the field to two systems--the lowest-cost regenerative thermal oxidation system on the market and a regenerative catalytic oxidation system. The company selected St. Louis, Mo.-based Monsanto Enviro-Chem Systems Inc., to install its DynaCycle{reg_sign} regenerative catalytic oxidation system, marking the first Dyna-Cycle installation in a US television picture-tube facility.

NONE

1995-11-01

212

[Pollution characteristics of VOCs in ambient air of Ji'nan City in summer].  

PubMed

Totally 56 kinds of volatile organic compounds (VOCs) in ambient air of Ji'nan City in summer 2010 were monitored by online GC to analyze their pollution characteristics and their relationship with weather conditions. The results showed that the majority of VOCs in ambient air in Ji'nan were alkanes, aromatics and olefins, accounting for 98.2% of the 56 kinds of total volatile organic compounds (TVOCs) detected. The concentrations of VOCs remained stable in June and July, and were significantly higher in mid and late August, and the quality percentages of the VOCs components showed some variations with changes in temperature. In sunny days, the diurnal variation curve of VOCs concentration had a bimodal characteristic, with the two peaks appearing in the rush hours with heavy traffic. There were no obvious bimodal distribution in rainy days and the concentrations were higher. The concentration of VOCs in ambient air in summer showed negative correlation with the wind speed and hours of sunshine, when the atmospheric stability was high, the pollutants were difficult to diffuse, which lead to increasing concentration of VOCs. The main sources of VOCs in Ji'nan are industrial emissions, motor vehicle emissions, the evaporation and leakage of gasoline, etc. PMID:23234002

Liu, Ze-Chang; Zhang, Fan; Hou, Lu-Jian; Liu, Yu-Tang; Lü, Bo

2012-10-01

213

An atmospheric emission inventory of anthropogenic and biogenic sources for Lebanon  

NASA Astrophysics Data System (ADS)

The Middle East region, which is a significant source for photochemical air pollution and a place for dust storms activities, is facing today serious air pollution problems. In this region, local inventory data are sparse and the development of an emission inventory is a challenge. In Lebanon, a small developing country in the Middle East region, data on air pollution are sketchy and the development of an emission inventory is an essential step to develop efficient emission control strategies to decrease air pollution levels. Accordingly, a temporally-resolved and spatially-distributed emission inventory was developed for Lebanon to provide quantitative information for air pollution studies as well as for use as input to air quality models. This inventory covers major anthropogenic and biogenic sources in the region with 5 km spatial resolution for Lebanon and 1 km spatial resolution for its capital city Beirut and its suburbs. The results obtained for CO, NOx, SO2, VOC, NH3, PM10 and PM2.5 show some differences with previous estimates. Emissions show different temporal and spatial patterns depending on the source categories. Major source contributions are on-road traffic (particularly in Beirut) and industry (particularly in Zouk Mikael, Jieh, Chekka, and Selaata). Pollutant ratios (CO/NOx and PM10/PM2.5) obtained from the emission inventory and ambient measurements are compared and major sources of uncertainty are identified.

Waked, A.; Afif, C.; Seigneur, C.

2011-12-01

214

Investigation of VOC radical sources in the Houston Area by the Solar Occultation Flux (SOF) method and Mobile DOAS  

NASA Astrophysics Data System (ADS)

The Solar Occultation Flux (SOF) method and mobile DOAS technique were used to measure industrial emissions of volatile organic compounds, formaldehyde, NO2 and SO2 in the Houston area during the time period April 15 to June 11, 2009. The measurements were conducted as part of the campaign FLAIR (Formaldehyde and alkenes from Large Industrial Releases) with the aim to better understand the role of formaldehyde for the photochemical production of ozone. The SOF technique is an optical method utilizing the absorption of direct solar infrared radiation in the 1.8-14 µm range for the retrieval of total columns of various species such as ethylene, propylene, ammonia and alkanes. Mobile DOAS utilizes scattered light in the ultraviolet spectral region for measurements of HCHO, SO2 and NO2. A crude chemical model has been applied to interprete whether the measured formaldehyde in the industrial emission plumes is primary emitted or secondary produced from oxidation of alkenes. The measured emissions of alkenes in the Houston Ship channel area were a factor of 10 higher than reported in the emission inventories and corresponded to about 600 kg/h for both ethene and propene. Several individual industrial sources of formaldehyde were identified in the Houston area. The emissions from these sources were relativaly small and ranged from a few kg/h up to over 40 kg/h. In most cases it was interpreted with the model that these corresponded to primary emissions of formaldehyde. However, a few large scale measurements further downwind the Houston ship channel showed formaldehyde fluxes (over 1000 kg/h) that could not be explained by the sum of the individual sources measured. These numbers are consistent with secondary production of formaldehyde from the alkene sources. Our conclusion is hence that the dominant part of the formaldehyde around the the Houston ship channel is being secondary produced from alkenes rather than coming from direct emissions.

Mellqvist, J.; Johansson, J.; Samuelsson, J.; Offerle, B.; Rappenglueck, B.

2010-12-01

215

Volatile organic compound (VOC) species data manual. Second edition  

SciTech Connect

This document contains tables of potential emissions of organic compounds for selected source categories. The species profile table format has been organized to be particularly useful in preparation of emission inventory inputs to photochemical modeling. Accompanying each VOC profile table is a brief narrative that describes process, emissions, controls, and basis of source report and data quantification. The chemical classifications include paraffin, olefin, aromatic, carbonyl (aldehydes and ketones), methane, non-reactive other than methane, and miscellaneous. Data confidence levels for each profile table have been assigned. Reports, published data, and names and titles of personal contacts are referenced for each source category.

Not Available

1980-07-01

216

Characterization of emissions sources in the California-Mexico Border Region during Cal-Mex 2010  

NASA Astrophysics Data System (ADS)

The California-Mexico border region provides an opportunity to evaluate the characteristics of the emission processes in rapidly expanding urban areas where intensive international trade and commerce activities occur. Intense anthropogenic activities, biomass burning, as well as biological and geological sources significantly contribute to high concentration levels of particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), nitrogen oxides (NOx), volatile organic compounds (VOCs), air toxics, and ozone observed in the California-US Baja California-Mexico border region. The continued efforts by Mexico and US for improving and updating the emissions inventories in the sister cities of San Diego-Tijuana and Calexico-Mexicali has helped to understand the emission processes in the border region. In addition, the recent Cal-Mex 2010 field campaign included a series of measurements aimed at characterizing the emissions from major sources in the California-Mexico border region. In this work we will present our analyzes of the data obtained during Cal-Mex 2010 for the characterization of the emission sources and their use for the evaluation of the recent emissions inventories for the Mexican cities of Tijuana and Mexicali. The developed emissions inventories will be implemented in concurrent air quality modeling efforts for understanding the physical and chemical transformations of air pollutants in the California-Mexico border region and their impacts.

Zavala, M. A.; Lei, W.; Li, G.; Bei, N.; Barrera, H.; Tejeda, D.; Molina, L. T.; Cal-Mex 2010 Emissions Team

2010-12-01

217

IMPROVING EMISSIONS ESTIMATES WITH COMPUTATIONAL INTELLIGENCE, DATABASE EXPANSION, AND COMPREHENSIVE VALIDATION  

EPA Science Inventory

The report discusses an EPA investigation of techniques to improve methods for estimating volatile organic compound (VOC) emissions from area sources. Using the automobile refinishing industry for a detailed area source case study, an emission estimation method is being developed...

218

[Volatile organic compounds (VOCs) emitted from large furniture].  

PubMed

Indoor air pollution by volatile organic compounds (VOCs), which may cause a hazardous influence on human being such as sick building (sick house) syndrome, has become a serious problem. In this study, VOCs emitted from nine pieces of home furniture, three sets of dining tables, three sets of chest of drawers and three sofas, were analyzed as potential sources of indoor air pollution by large chamber test method (JIS A 1911). Based on the emission rates of total VOC (TVOC), the impacts on the indoor TVOC was estimated by the sample model with a volume of 20 m3 and ventilation frequency of 0.5 times/h. The estimated TVOC increment values were exceeded the provisional target value for indoor air (400 microg/m3) in three sets of dining tables, one set of chest of drawer and one sofa. The estimated increment of formaldehyde were exceeded the guideline value (100 microg/m3) in one set of dining table, two sets of chest of drawers and one sofa. These results revealed that VOC emissions from 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 three parts of furniture unit were evaluated using the small chamber and emission rate from full-sized furniture was predicted. Emission rates of TVOC and formaldehyde predicted by small chamber test were 3-46% and 6-252% of the data obtained using large chamber test, respectively. PMID:22259846

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

2011-01-01

219

Biogenic VOC Emissions Measured by Solid Phase Microextraction (SPME) Fibers, Proton Transfer Reaction Mass Spectrometry (PTR-MS), and In-situ Gas Chromatography (GC)  

NASA Astrophysics Data System (ADS)

Chemical ozone loss due to reactions with biogenic VOCs has been shown to dominate ozone flux measured at Blodgett Forest, a coniferous forest in the Sierra Nevada Mountains of California. Here we report recent efforts to measure the specific biogenic VOCs involved in this chemistry at Blodgett Forest. During summer 2005, we enclosed branches of Ponderosa pine, manzanita, and ceanothus species and made VOC emission measurements by proton transfer reaction mass spectrometry (PTR-MS), solid phase microextraction (SPME) on fibers followed by direct injection into a gas chromatograph with an ion trap mass spectrometer (GC-ITMS), and by in-situ GC with a flame ionization detector (GC-FID). Zero air, with ambient CO2 concentrations, flowed through a 2-chamber system. The chamber placed directly over the branch had a 20 second residence time, and was immediately followed by a reaction chamber with a 2 minute residence time. The PTR-MS and GC-FID measurement cycled between each of the two chambers and the zero air supply. SPME fibers (65 ?m PDMS/DVB field portable) were used to sample the branch chamber. Several sesquiterpene, monoterpene, and oxygenated primary emissions were identified. The SPME fibers were particularly useful for detecting sesquiterpenes which are typically difficult to measure due to their high reactivity in the forest canopy and losses in sampling lines. Comparisons of SPME fiber data with PTR-MS and GC-FID data for sesquiterpenes (m/z 205), 4-allylanisole (m/z 149), and monoterpenes (m/z 137) will be presented to assess the actual emission rates and the complimentary information provided by each measurement approach.

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

2005-12-01

220

Emission source strengths of gasoline-filling processes determined by open-path spectroscopic techniques and inverse modeling  

NASA Astrophysics Data System (ADS)

Up to now emission source strengths of diffuse and heterogenous emission of important VOCs are not well known especially from gas stations and gasoline tank farms. To estimate the total emission of these sources non-intrusive measurements were performed by a differential optical absorption spectroscopy (DOAS) system to determine the path- integrated concentrations of exhaust compounds downwind of the source through the whole exhaust plume. Simultaneously, the meteorological parameters were measured for modeling the dispersion of the plume inversely to obtain the emission source strengths of these compounds. The emissions by road traffic were determined by an additional open-path DOAS measurement. Measurement campaigns were performed during different wether conditions and at different sources which were characterized by well defined and easy air flow conditions. The emission source strengths were calculated with the Gaussian model PAL. The determined total emission of gas stations with gasoline vapor recovery system are about 20 mg benzene per kg refueled gasoline and the emission from refueling activities vary between 1 and 9 benzene per kg refueled gasoline depending on the technical behavior of the gasoline vapor recovery system. These values which were found from measurements during times with a and without refueling activities show a high amount of diffuse emissions. The emission rates from a gasoline taken farm were measured on an open path through the middle of that area and a maximum of 8 (mu) g/(m2s) was determined.

Schaefer, Klaus; Stockhause, Martina; Hoffmann, Herbert; Sedlmaier, Achim; Emeis, Stefan M.

1998-12-01

221

Modeling mobile source emissions in presence of stationary sources  

Microsoft Academic Search

The impact of oxides of nitrogen (NOx) emissions from motor vehicles to the air quality in city-state Singapore is analyzed using AIRVIRO, a regional scale dispersion model developed by the Swedish Meteorological and Hydrological Institute. In a predominantly urban location like Singapore, it is difficult to separate out the contribution of pollutants from mobile and point sources at different locations.

Preety Mukherjee; Shekar Viswanathan; Lim Cheng Choon

2000-01-01

222

A general analytical model for formaldehyde and VOC emission/sorption in single-layer building materials and its application in determining the characteristic parameters  

NASA Astrophysics Data System (ADS)

A general analytical model for characterizing emission and sorption of formaldehyde and volatile organic compounds (VOCs) in single-layer building materials is developed. Compared with traditional models, the present model can be applicable for four kinds of typical physical processes, i.e., emission in ventilated and airtight chambers, and sorption in these two types of chambers. Based on the general analytical model, a novel method is proposed to determine the characteristic parameters (the diffusion coefficient, Dm, and the material/air partition coefficient, K) of formaldehyde and VOC sorption in ventilated and airtight chambers. It establishes a linear relationship between the logarithm of dimensionless excess concentration and sorption time, and the Dm and K can be conveniently obtained from the slope and intercept of the regression line. The results of applying the present model are compared with the experimental data in the literature. The good agreement between them not only validates the model but also demonstrates that the measured characteristic parameters are accurate and reliable. The general analytical model should prove useful for unified characterization and prediction of emission/sorption in building materials as well as for parameter measurement.

Xiong, Jianyin; Liu, Cong; Zhang, Yinping

2012-02-01

223

Static SPME sampling of VOCs emitted from indoor building materials: prediction of calibration curves of single compounds for two different emission cells.  

PubMed

Solid-phase microextraction (SPME) is a powerful technique, easy to implement for on-site static sampling of indoor VOCs emitted by building materials. However, a major constraint lies in the establishment of calibration curves which requires complex generation of standard atmospheres. Thus, the purpose of this paper is to propose a model to predict adsorption kinetics (i.e., calibration curves) of four model VOCs. The model is based on Fick's laws for the gas phase and on the equilibrium or the solid diffusion model for the adsorptive phase. Two samplers (the FLEC® and a home-made cylindrical emission cell), coupled to SPME for static sampling of material emissions, were studied. A good agreement between modeling and experimental data is observed and results show the influence of sampling rate on mass transfer mode in function of sample volume. The equilibrium model is adapted to quite large volume sampler (cylindrical cell) while the solid diffusion model is dedicated to small volume sampler (FLEC®). The limiting steps of mass transfer are the diffusion in gas phase for the cylindrical cell and the pore surface diffusion for the FLEC®. In the future, this modeling approach could be a useful tool for time-saving development of SPME to study building material emission in static mode sampling. PMID:21400078

Mocho, Pierre; Desauziers, Valérie

2011-03-12

224

Evaluation of formaldehyde and VOCs emission factors from paints in a small chamber: the effects of preconditioning time and coating weight.  

PubMed

The aims of this study were to improve the emission test method for the 20 L small chamber standardized in Korea using paints and to develop an optical test method for paints. The emission factors of the total volatile organic compounds (TVOC) and formaldehyde from oil-based paints, emulsion paints and water-dispersion paints coated at 300 g/m(2) and cured for 24 (48)h were determined using the 20 L small chamber method. The emission factors of TVOC and formaldehyde from all paints under steady state conditions were determined after 7 days with 24 (48)h of curing. The Korean standards require that paints be measured and analyzed on the third day after a test. However, the emission factors of TVOC and formaldehyde from the paints only began to stabilize 7 days after installing the samples. Until now, the emission test results have been reported mainly as concentration vs. time or emission factor vs. time profiles of TVOC and formaldehyde. The emission factors of the target volatile organic compounds (VOCs) and aldehyde types were obtained under specific test conditions according to the different coating weights. For all target volatile organic compounds and aldehyde types examined, the paint coating weight had an effect on emission. PMID:21112140

Kim, Jin-A; Kim, Sumin; Kim, Hyun-Joong; Kim, Yong-Shik

2010-11-02

225

40 CFR 62.08 - Emission inventories and source surveillance.  

Code of Federal Regulations, 2013 CFR

...Emission inventories and source surveillance. 62.08 Section 62.08...Emission inventories and source surveillance. (a) Each subpart identifies the plan provisions for source surveillance which are disapproved,...

2013-07-01

226

Revealing source signatures in ambient BTEX concentrations.  

PubMed

Management of ambient concentrations of Volatile Organic Compounds (VOCs) is essential for maintaining low ozone levels in urban areas where its formation is under a VOC-limited regime. The significant decrease in traffic-induced VOC emissions in many developed countries resulted in relatively comparable shares of traffic and non-traffic VOC emissions in urban airsheds. A key step for urban air quality management is allocating ambient VOC concentrations to their pertinent sources. This study presents an approach that can aid in identifying sources that contribute to observed BTEX concentrations in areas characterized by low BTEX concentrations, where traditional source apportionment techniques are not useful. Analysis of seasonal and diurnal variations of ambient BTEX concentrations from two monitoring stations located in distinct areas reveal the possibility to identify source categories. Specifically, the varying oxidation rates of airborne BTEX compounds are used to allocate contributions of traffic emissions and evaporative sources to observed BTEX concentrations. PMID:18289752

Zalel, Amir; Yuval; Broday, David M

2008-03-04

227

64 FR 6946 - National Emission Standards for Hazardous Air Pollutants for Source Categories; National Emission...  

Federal Register 2010, 2011, 2012, 2013

...National Emission Standards for Hazardous Air Pollutants for Source Categories; National Emission Standards for Hazardous Air Pollutants for Secondary Aluminum Production...National Emission Standards for Hazardous Air Pollutants for Source Categories;...

1999-02-11

228

63 FR 19582 - National Emission Standards for Hazardous Air Pollutants for Source Categories: National Emission...  

Federal Register 2010, 2011, 2012, 2013

...National Emission Standards for Hazardous Air Pollutants for Source Categories: National...National Emission Standards for Hazardous Air Pollutants for Source Categories: National...national emission standards for hazardous air pollutants (NESHAP) for new and...

1998-04-20

229

62 FR 52384 - National Emission Standards for Hazardous Air Pollutants for Source Categories; National Emission...  

Federal Register 2010, 2011, 2012, 2013

...National Emission Standards for Hazardous Air Pollutants for Source Categories; National Emission Standards for Hazardous Air Pollutants for Primary Aluminum Reduction...National Emission Standards for Hazardous Air Pollutants for Source Categories;...

1997-10-07

230

62 FR 49052 - National Emission Standards for Hazardous Air Pollutants for Source Categories; National Emission...  

Federal Register 2010, 2011, 2012, 2013

...National Emission Standards for Hazardous Air Pollutants for Source Categories; National Emission Standards for Hazardous Air Pollutants for Steel Pickling Facilities...National Emission Standards for Hazardous Air Pollutants for Source Categories;...

1997-09-18

231

64 FR 29490 - National Emission Standards for Hazardous Air Pollutants for Source Categories; National Emission...  

Federal Register 2010, 2011, 2012, 2013

...National Emission Standards for Hazardous Air Pollutants for Source Categories and for...National Emission Standards for Hazardous Air Pollutants for Source Categories; National Emission Standards for Hazardous Air Pollutants for Mineral Wool Production...

1999-06-01

232

62 FR 25370 - National Emission Standards for Hazardous Air Pollutants for Source Categories; National Emission...  

Federal Register 2010, 2011, 2012, 2013

...National Emission Standards for Hazardous Air Pollutants for Source Categories; National Emission Standards for Hazardous Air Pollutants for Mineral Wool Production...National Emission Standards for Hazardous Air Pollutants for Source Categories;...

1997-05-08

233

63 FR 48890 - National Emission Standards for Hazardous Air Pollutants for Source Categories; National Emission...  

Federal Register 2010, 2011, 2012, 2013

...National Emission Standards for Hazardous Air Pollutants for Source Categories; National Emission Standards for Hazardous Air Pollutants From Petroleum Refineries...National Emission Standards for Hazardous Air Pollutants for Source Categories;...

1998-09-11

234

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

235

The urban atmosphere as a non-point source for the transport of MTBE and other volatile organic compounds (VOCS) to shallow groundwater  

USGS Publications Warehouse

Infiltration and dispersion (including molecular diffusion) can transport volatile organic compounds (VOCs) from urban air into shallow groundwater. The gasoline additive methyl-tert-butyl ether (MTBE) is of special interest because of its (1) current levels in some urban air, (2) strong partitioning from air into water, (3) resistance to degradation, (4) use as an octane-booster since the 1970s, (5) rapidly increasing use in the 1990s to reduce CO and O3 in urban air, and (6) its frequent detection rat lOW microgram per liter levels in shallow urban groundwater in Denver, New England, and elsewhere. Numerical simulations were conducted using a l-D model domain set in medium sand (depth to water table = 5 m) to provide a test of whether MTBE and other atmospheric VOCs could move to shallow groundwater within the 10-15 y time frame over which MTBE has now been used in large amounts. Degradation and sorption were assumed negligible. In case 1 (no infiltration, steady atmospheric source), 10 y was not long enough to permit significant VOC movement by diffusion into shallow groundwater. Case 2 considered a steady atmospheric source plus 36 cm/y of net infiltration; groundwater at 2 m below the water table became nearly saturated with atmospheric levels of VOC within 5 y. Case 3 was similar to case 2, but considered the source to be seasonal being 'on' for only 5 of 12 months each year, as with the use of MTBE during the winter fuel-oxygenate season; groundwater at 2 m below the water table became equilibrated with 5/12 of the 'source-on' concentration within 5 y. Cases 4 and 5 added an evapotranspiration (ET) loss of 36 cm/y, resulting in no net recharge. Case 4 took the ET from the surface, and case 5 took the ET from the capillary fringe at a depth of 3.5 m. Net VOC mass transfer to shallow groundwater after 5 y was less for both cases 4 and 5 than for case 3. However, it was significantly greater for cases 4 and 5 than for case 1, even though cases 1, 4, add 5 were all no- net recharge cases. The mechanism responsible for this effect was the dispersion acting on each downward infiltration event, and also on the ET-induced flow. The ability of MTBE to reach groundwater in cases 2-5 is taken as evidence of the potential importance of urban air as a non-point source for VOCs in shallow urban groundwater. Two subcases were run for both case 4 and case 5: subcase a (water and VOCs move with ET) and subcase b (water only moves with ET).Numerical simulations were conducted using a 1-D model domain set in medium sand to provide a test of whether methyl-tert-butyl ether (MTBE) and other atmospheric volatile organic compounds could move to shallow groundwater within the 10-15 y time frame over which MTBE was used in large amounts. The gasoline additive MTBE is of special interest because of its: current levels in some urban air; strong partitioning from air into water; resistance to degradation; use as an octane-booster since the 1970s; rapidly increasing use in the 1990s to reduce CO and O3 in urban air; and its frequent detection at low microgram per liter levels in shallow urban groundwater.

Pankow, J. F.; Thomson, N. R.; Johnson, R. L.; Baehr, A. L.; Zogorski, J. S.

1997-01-01

236

Impacts of different emission sources on air quality during March 2001 in the Pearl River Delta (PRD) region  

NASA Astrophysics Data System (ADS)

This study focuses on the role played by emissions from transportation, industry and power generation on the concentrations of O 3, CO, NO, NO y and SO 2 in Guangdong province of China. Observational data of the pollutants and numerical modeling of atmospheric chemistry, transport and removal processes with STEM-2K1 and MM5 are used for March 2001. The objective is to identify the relative importance of the three emission sources on the concentrations of the pollutants. In addition, the relative importance of NO x and VOC emissions from the transportation sector for O 3 production is examined. The observations at a rural and an urban site in the region show distinctive characteristics, indicating the importance of local emissions. A comparison of the observed ratios of CO/NO x and SO 2/NO x at the two sites with those derived from the emission inventories show the usefulness of the emission inventories. A control simulation with all emissions included shows a fairly satisfactory performance of the model in terms of the comparison between the observed and modeled concentrations of CO, SO 2, NO y and O 3 at the rural site, although the observed extremes are less well simulated. Three simulations with different emission scenarios suggest that the transportation source was the main contributor to NO x, CO and O 3 concentrations accounting for 34.2%, 33.1% and 17.8% of their total concentrations, respectively. For SO 2 concentration, the main contributor is the power plant sources with a contribution rate of 32.9%. For SO 2, the doubling of emissions from the industry has a much larger effect on the ambient levels than the doubling from the transportation, whereas the increase in the transportation sector sources has approximately twice the effect of the increased industrial emission on O 3. The doubling of emissions from the transportation and industry sources would increase the O 3 concentration by about 26.7% and 8.5% for the whole region. Finally, the O 3/NO z ratio of 25 was found to be a reasonable threshold to separate NO x-limited and VOC-limited regimes concerning O 3 chemistry. It is found that the urban area is VOC-limited and the non-urban area is NO x-limited. These results have implications for O 3 control strategy for the region.

Wang, Xuemei; Carmichael, Gregory; Chen, Deliang; Tang, Youhua; Wang, Tijian

237

An in-source stretched membrane inlet for on-line analysis of VOCs in water with single photon ionization TOFMS.  

PubMed

An in-source, stretched, hollow fiber membrane (HFM) inlet has been developed to improve the sensitivity of on-line time-of-flight mass spectrometry (TOFMS) with a vacuum ultraviolet (VUV) lamp based single photon ionization (SPI) source for the direct analysis of liquid samples. A 2-cm HFM was stretched to 8 cm in length, and placed in the ion source and directly under the VUV lamp window with a distance of 15 mm. Compared with the conventional flow-through configuration under the same experimental conditions, the signal intensities of selected volatile organic compounds (VOCs) of methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), benzene, toluene and p-xylene were increased over 5-fold in magnitude, and the response time was shortened to one-third. The limits of detection (LOD) of MTBE, ETBE, benzene, toluene and p-xylene ranged from 0.25 to 1.3 ?g L(-1) with a measurement time of 60 s, and three orders of linear range were obtained with correlation coefficients of 0.9972-0.9992. The present results suggest that the in-source stretched HFM is a simple and effective way to increase the sensitivity and shorten response time of the membrane inlet, and we believe that it will also be beneficial to other types of on-line mass spectrometer for the on-line analysis of VOCs in water with a VUV lamp based SPI ion source. PMID:23907373

Hou, Keyong; Li, Fanglong; Chen, Wendong; Chen, Ping; Xie, Yuanyuan; Zhao, Wuduo; Hua, Lei; Pei, Kemei; Li, Haiyang

2013-10-01

238

NMHC emissions from Asia: sources and transport  

NASA Astrophysics Data System (ADS)

Recent rapid industrialization and economic growth in Asia changed the industrial structure, land use, and people's lifestyle resulting in a dramatic change in the amount and composition of the gas emissions from Asia. Because emissions can be transported very rapidly once convected to the free troposphere, Asian emissions can affect both local and regional air quality and climate. To access the impact of changing emission from Asia, an airborne observation campaign PEACE (the Pacific Exploration of Asian Continental Emission) phase-A and B were conducted in January and April - May 2002, respectively, sponsored by NASDA (National Space Development Agency of Japan). The concentrations of NMHCs (nonmethanehydrocarbons) and halocarbons were obtained by whole air sampling and subsequent gas chromatography analyses in the laboratory. Quantified onboard the aircraft were CO, CO2, O3, NO, NO2, NOy, H2O, SO2, aerosols, and condensation nuclei. The experiment was conducted in the vicinity of Japan and PEACE-A and B represent the local winter and spring weather conditions. The trace gas distributions in the lower troposphere were often influenced by local pollution (i.e. from Japan, Korea) while those of the long-range transport (i.e. from Europe) were occasionally seen in the upper troposphere. This is confirmed by the airmass age estimation using the ratios of short-lived gases (i.e. C2H4) vs. more stable compounds (i.e. CO). Emissions from China were distinguished using data obtained from ground-based sampling and measurements. Transport from China was seen both in the lower troposphere and upper troposphere. Some case studies on source identification will be discussed.

Shirai, T.; Blake, D. R.; Barletta, B.; Meinardi, S.; Rowland, F. S.; Chan, J. C.; Takegawa, N.; Kondo, Y.; Koike, M.; Kita, K.; Takigawa, M.; Kawakami, S.; Ogawa, T.

2002-12-01

239

40 CFR 60.25 - Emission inventories, source surveillance, reports.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Emission inventories, source surveillance, reports. 60.25 Section 60.25 Protection of Environment...Designated Facilities § 60.25 Emission inventories, source surveillance, reports. (a) Each plan shall include an...

2013-07-01

240

40 CFR 62.4622 - Emission inventories, source surveillance, reports.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Emission inventories, source surveillance, reports. 62.4622 Section 62.4622 Protection...d) Plan) § 62.4622 Emission inventories, source surveillance, reports. (a) The requirements of §...

2013-07-01

241

75 FR 31937 - Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources...  

Federal Register 2010, 2011, 2012, 2013

...CFR Part 60 Standards of Performance for New Stationary Sources and Emission Guidelines...2060-AO12 Standards of Performance for New Stationary Sources and Emission Guidelines...SUMMARY: On December 1, 2000, EPA adopted new source performance standards and...

2010-06-04

242

76 FR 15371 - Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources...  

Federal Register 2010, 2011, 2012, 2013

...CFR Part 60 Standards of Performance for New Stationary Sources and Emission Guidelines...2060-AP90 Standards of Performance for New Stationary Sources and Emission Guidelines...SUMMARY: This action promulgates EPA's new source performance standards and...

2011-03-21

243

DEVELOPING A NO-VOC WOOD TOPCOAT  

EPA Science Inventory

The paper reports an evaluation of a new low-VOC (volatile organic compound) wood coating technology, its performance characteristics, and its application and emissions testing. The low-VOC wood coating selected for the project was a two-component, water-based epoxy coating. Poly...

244

Budgets for nocturnal VOC oxidation by nitrate radicals aloft during the 2006 Texas Air Quality Study  

NASA Astrophysics Data System (ADS)

Industrial emissions in Houston, Texas, and along the U.S. Gulf Coast are a large source of highly reactive anthropogenic volatile organic compounds (VOCs), principally alkenes, that affect air quality in that region. Nighttime oxidation by either O3 or NO3 removes these VOCs. This paper presents a regional analysis of nighttime P-3 flights during the 2006 Texas Air Quality Study (TexAQS) to quantify the loss rates and budgets for both NO3 and highly reactive VOC. Mixing ratios and production rates of NO3 were large, up to 400 parts per trillion by volume (pptv) and 1-2 parts per billion by volume (ppbv) per hour, respectively. Budgets for NO3 show that it was lost primarily to reaction with VOCs, with the sum of anthropogenic VOCs (30-54%) and isoprene (10-50%) being the largest contributors. Indirect loss of NO3 to N2O5 hydrolysis was of lesser importance (14-28%) but was the least certain due to uncertainty in the aerosol uptake coefficient for N2O5. Reaction of NO3 with peroxy radicals was a small but nonzero contribution to NO3 loss but was also uncertain because there were no direct measurements of peroxy radicals. Net VOC oxidation rates were rapid (up to 2 ppbv VOC h-1 in industrial plumes) and were dominated by NO3, which was 3-5 times more important as an oxidant than O3. Plumes of high NO3 reactivity (i.e., short steady state lifetimes, on the order of 1 min) identified the presence of concentrated emissions of highly reactive VOCs from the Houston Ship Channel (HSC), which, depending on the particular VOC, may be efficiently oxidized during overnight transport.

Brown, Steven S.; Dubé, William P.; Peischl, Jeff; Ryerson, Thomas B.; Atlas, Elliot; Warneke, Carsten; de Gouw, Joost A.; Te Lintel Hekkert, Sacco; Brock, Charles A.; Flocke, Frank; Trainer, Michael; Parrish, David D.; Feshenfeld, Frederick C.; Ravishankara, A. R.

2011-12-01

245

Modeling VOC transport in simulated waste drums  

SciTech Connect

A volatile organic compound (VOC) transport model has been developed to describe unsteady-state VOC permeation and diffusion within a waste drum. Model equations account for three primary mechanisms for VOC transport from a void volume within the drum. These mechanisms are VOC permeation across a polymer boundary, VOC diffusion across an opening in a volume boundary, and VOC solubilization in a polymer boundary. A series of lab-scale experiments was performed in which the VOC concentration was measured in simulated waste drums under different conditions. A lab-scale simulated waste drum consisted of a sized-down 55-gal metal drum containing a modified rigid polyethylene drum liner. Four polyethylene bags were sealed inside a large polyethylene bag, supported by a wire cage, and placed inside the drum liner. The small bags were filled with VOC-air gas mixture and the VOC concentration was measured throughout the drum over a period of time. Test variables included the type of VOC-air gas mixtures introduced into the small bags, the small bag closure type, and the presence or absence of a variable external heat source. Model results were calculated for those trials where the VOC permeability had been measured. Permeabilities for five VOCs [methylene chloride, 1,1,2-trichloro-1,2,2-trifluoroethane (Freon-113), 1,1,1-trichloroethane, carbon tetrachloride, and trichloroethylene] were measured across a polyethylene bag. Comparison of model and experimental results of VOC concentration as a function of time indicate that model accurately accounts for significant VOC transport mechanisms in a lab-scale waste drum.

Liekhus, K.J.; Gresham, G.L.; Peterson, E.S.; Rae, C.; Hotz, N.J.; Connolly, M.J.

1993-06-01

246

Cost effectiveness of Silent Discharge Plasma for point-of-use VOC emissions control in semiconductor fabrication  

SciTech Connect

Extensive research into the treatment and control of Volatile Organic Compounds (VOCs) from semiconductor industry manufacturing processes has identified the need for alternatives to existing combustion devices. Specifically, semiconductor manufacturing design is moving toward exploiting effective, small-scale, abatement control technologies for specific point-of-use (POU) waste streams associated with a particular component or manufacturing tool. The Silent Discharge Plasma (SDP) developed at Los Alamos National Laboratory is a nonthermal plasma technology created by a dielectric-ballasted electrical discharge. Influent gas-phase pollutants are destroyed in the reactor by the free radicals or electrons generated by the plasma. This paper examines the potential for SDP to be used in niche circumstances for POU control of VOC exhaust streams specific to the semiconductor industry. A sensitivity analysis is presented, showing how SDP cost of ownership is affected by changes in the major operational parameters of exhaust flow rate, target compound, destruction removal efficiency (DRE), and electrical duty cycle. The results of cost analysis show that SDP performance and cost effectiveness are flow rate- and compound-specific. The authors conclude that the Silent Discharge Plasma is a viable, cost effective technology under high-concentration, low-flow rate regimes, and for target compounds that have been empirically shown to be conducive to destruction via free radical chemistry.

Cummings, M.; Coogan, J.

1997-07-01

247

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

Federal Register 2010, 2011, 2012, 2013

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

2012-08-07

248

Microscopic fungi as significant sesquiterpene emission sources  

NASA Astrophysics Data System (ADS)

Among the volatile organic compounds emitted by vegetation, isoprene, monoterpenes, sesquiterpenes, and their derivatives are thought to contribute to secondary organic aerosol formation. Although it is well known that microscopic fungi globally turn over vast amount of carbon by decomposing the organic matter in the soil, vegetation is considered as the exclusive source of biogenic secondary organic aerosol precursors in various atmospheric models. Secondary fungal metabolites including sesquiterpenes have been recognized as characteristic volatile organic compounds emitted by fungi. In the present study, we investigated the rates of sesquiterpene emission of microscopic fungi to establish their potential significance compared to those from vegetation. To sample the headspace of the pure culture of some common fungi, we used an aseptic flow-through apparatus designed for solid phase microextraction in our laboratory. The identified sesquiterpenes in the headspace extracts were quantified for eight strains of microscopic fungi belonging to four different genera. Our results showed that microscopic fungi emit a considerable amount of sesquiterpenes. Based on our first estimations microscopic fungi may be considered as potentially significant sesquiterpene emission sources whose contribution to secondary organic aerosol formation may be comparable to that of vegetation.

HorváTh, Eszter; Hoffer, AndráS.; Seb?K, Flóra; Dobolyi, Csaba; Szoboszlay, SáNdor; Kriszt, BaláZs; GelencséR, AndráS.

2011-08-01

249

Volatile organic compounds (VOCs) in soils  

Microsoft Academic Search

Soils may act as sources or sinks of volatile organic compounds (VOCs). Many of the formed VOCs are produced by microorganisms,\\u000a and it would be a challenge to investigate soil microbial communities by studying their VOC profile. Such “volatilomics” would\\u000a have the advantage of avoiding extraction steps that are often a limit in genomic or proteomic approaches. Abundant literature\\u000a on

Heribert Insam; Martin S. A. Seewald

2010-01-01

250

Atmospheric process evaluation of mobile source emissions  

SciTech Connect

During the past two decades there has been a considerable effort in the US to develop and introduce an alternative to the use of gasoline and conventional diesel fuel for transportation. The primary motives for this effort have been twofold: energy security and improvement in air quality, most notably ozone, or smog. The anticipated improvement in air quality is associated with a decrease in the atmospheric reactivity, and sometimes a decrease in the mass emission rate, of the organic gas and NO{sub x} emissions from alternative fuels when compared to conventional transportation fuels. Quantification of these air quality impacts is a prerequisite to decisions on adopting alternative fuels. The purpose of this report is to present a critical review of the procedures and data base used to assess the impact on ambient air quality of mobile source emissions from alternative and conventional transportation fuels and to make recommendations as to how this process can be improved. Alternative transportation fuels are defined as methanol, ethanol, CNG, LPG, and reformulated gasoline. Most of the discussion centers on light-duty AFVs operating on these fuels. Other advanced transportation technologies and fuels such as hydrogen, electric vehicles, and fuel cells, will not be discussed. However, the issues raised herein can also be applied to these technologies and other classes of vehicles, such as heavy-duty diesels (HDDs). An evaluation of the overall impact of AFVs on society requires consideration of a number of complex issues. It involves the development of new vehicle technology associated with engines, fuel systems, and emission control technology; the implementation of the necessary fuel infrastructure; and an appropriate understanding of the economic, health, safety, and environmental impacts associated with the use of these fuels. This report addresses the steps necessary to properly evaluate the impact of AFVs on ozone air quality.

NONE

1995-07-01

251

Source Analysis of Volatile Organic Compounds by Positive Matrix Factorization in Urban and Rural Environments in Beijing  

NASA Astrophysics Data System (ADS)

This study applies advance receptor model positive matrix factorization (PMF) source analysis to one-hour resolution VOC data collected at Yufa (rural site) and Peking University, or PKU (urban site), in Beijing. A range of major VOC sources was identified, including vehicle emissions, LPG, coal combustion and biogenic emissions. Vehicle activities contributed approximately 62% of VOC loading and 55% of ozone forming potential at the PKU site, compared to 38% of VOC loading and 42% of ozone forming potential at Yufa. These results indicate that the control of vehicle emissions is essential to alleviating VOC pollution, particularly in urban Beijing. We found that VOC emission strengths are relatively consistent throughout the day in the rural area; variation of mixing height therefore is a controlling factor for ground-level VOC concentration. While in the urban area, both vehicle activity and variation of mixing height strongly impact VOC levels. Local sources within Beijing appeared to contribute most of the VOCs recorded at both urban and rural areas. However, as some of the VOC species are quite reactive, VOC emitted from distant sources would have been depleted during transportation, concurrent with the formation of secondary pollutants such as ozone and sulfate. Such depletion would mean that this source apportionment analysis would tend to overestimate the ozone forming capacity of local VOC sources compared to emissions from distant sources. Nevertheless, this study illustrates that high-resolution VOC measurements, especially those with a sampling frequency on the scale of less than one day, combined with PMF, can make a strong contribution to our understanding of pollutant emissions and transport characteristics, and is a useful tool with which to formulate effective pollution control strategies.

Yuan, Z.; Lau, A. K.; Shao, M.; Louie, P. K.; Liu, S. C.; Zhu, T.

2009-05-01

252

Source analysis of volatile organic compounds by positive matrix factorization in urban and rural environments in Beijing  

NASA Astrophysics Data System (ADS)

This paper applies advance receptor model positive matrix factorization (PMF) source analysis to 1-h resolution VOC data collected at Yufa (rural site) and Peking University, or PKU (urban site), in Beijing. A range of major VOC sources was identified, including vehicle emissions, liquefied petroleum gas, coal combustion, and biogenic emissions. Vehicle activities contributed approximately 62% of VOC loading and 55% of ozone forming potential at the PKU site, compared to 38% of VOC loading and 42% of ozone forming potential at Yufa. These results indicate that the control of vehicle emissions is essential to alleviating VOC pollution, particularly in urban Beijing. We found that VOC emission strengths are relatively consistent throughout the day in the rural area; variation of mixing height therefore is a controlling factor for ground-level VOC concentration. In the urban area, both vehicle activity and variation of mixing height strongly impact VOC levels. Local sources within Beijing appeared to contribute most of the VOCs recorded at both urban and rural areas. However, as some of the VOC species are quite reactive, VOC emitted from distant sources would have been depleted during transportation, concurrent with the formation of secondary pollutants such as ozone and sulfate. Such depletion would mean that this source apportionment analysis would tend to overestimate the ozone forming capacity of local VOC sources compared to emissions from distant sources. Nevertheless, this study illustrates that high-resolution VOC measurements, especially those with a sampling frequency on the scale of less than 1 day, combined with PMF, can make a strong contribution to our understanding of pollutant emissions and transport characteristics and is a useful tool with which to formulate effective pollution control strategies.

Yuan, Zibing; Lau, Alexis Kai Hon; Shao, Min; Louie, Peter K. K.; Liu, Shaw Chen; Zhu, Tong

2009-01-01

253

Sulfur emissions to the atmosphere from natural sources  

NASA Astrophysics Data System (ADS)

To assess the relative importance of natural and anthropogenic sources the measurements of sulfur gases and fluxes during the past decade are combined to create a global emission inventory. The inventory, which is divided into 12 latitude belts, takes into account the seasonal dependence of sulfur emissions from biogenic sources. The total emissions of sulfur gases from natural sources are approximately 0.79 Tmol S/a. These emissions are 16 percent of the total sulfur emissions in the Northern Hemisphere and 58 percent in the Southern Hemisphere. The inventory clearly shows the impact of anthropogenic sulfur emissions in the region between 35 and 50 deg N.

Bates, T. S.; Lamb, B. K.; Guenther, A.; Dignon, J.; Stoiber, R. E.

1992-04-01

254

Evaluation of Low-VOC Latex Paints.  

National Technical Information Service (NTIS)

The paper gives results of an evaluation of four commercially available low-VOC (volatile organic compound) latex paints as substitutes for conventional latex paints by assessing both their emission characteristics and their performance as coatings. Bulk ...

J. C. S. Chang R. C. Fortmann N. F. Roache H. C. Lao

1999-01-01

255

PAVED ROAD PARTICULATE EMISSIONS: SOURCE CATEGORY REPORT  

EPA Science Inventory

The report gives results of extensive field tests to develop emission factors for particulate emissions generated by traffic entrainment of paved road surface particulate matter. Using roadway surface silt loading as the basis, predictive emission factor equations for each partic...

256

Variations in amounts and potential sources of volatile organic chemicals in new cars.  

PubMed

This study examines inter-brand, intra-brand and intra-model variations in volatile organic chemical (VOC) levels inside new cars. The effect of temperature on interior VOC levels was examined using model automobiles with and without the air-conditioning running. Potential sources of VOC were assessed by comparing VOC levels with two interior trims (leather and fabric) and by analyzing VOC emissions from various interior components. Five brands of new car, both domestic and imported, were tested. Twelve targeted VOCs were collected on solid sorbents and analyzed using thermal desorption and GC/FID. VOCs from interior parts and adhesives were identified using solid phase micro-extraction (SPME) coupled with GC/MS. The VOC concentrations varied markedly among brands and within models, and individual VOC levels ranged from below the detection limit (a few mug per cubic meter) to thousands of mug per cubic meter. The intra-model variability (mean, 47%) in the VOC levels was approximately 50% that within each brand (mean, 95%). Although interior trim levels affected VOC levels, the effects differed among brands. Reduction of the cabin temperature reduced most VOC levels, but the impact was not statistically significant. Screening tests for VOCs from interior parts revealed that butylated hydroxytoluene (BHT), a common anti-oxidant, was the most common chemical. Long-chain aliphatic hydrocarbons, particularly C14-C17, were identified in most grease (lubricant) samples, and toluene and xylenes were ubiquitously present in adhesive samples. Process-related compounds, such as plasticizer, were also identified in interior parts. In-cabin VOC levels varied significantly among makes/models and interior trims. Concerned consumers should purchase older new cars from manufacturers since VOC levels inside car cabins normally declines over time. Improved processes or materials with lower VOC emission potential should be used to minimize in-cabin VOC sources for new cars. PMID:17540434

Chien, Yeh-Chung

2007-05-30

257

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

Microsoft Academic Search

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

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

2006-01-01

258

Mobile IR and UV-Spectroscopic Measurements of CO, SO2 and VOC in Megacities  

Microsoft Academic Search

Three different types of optical instruments have been deployed at a field campaign in the Mexico City Metropolitan Area (MCMA) 2003 within three main applications: 1) Retrieval of total columns of CO at various positions within the MCMA. 2) Emission inventory of VOC (volatile organic compounds) and SO2 from a major industrial source in Tula 100km north of the MCMA.

J. Samuelsson; J. Mellqvist; B. Galle; B. de Foy; A. Garcia; L. T. Molina; M. J. Molina; R. Volkamer; E. Flores; M. Grutter

2004-01-01

259

Comparison of seasonal phenol and p-cresol emissions from ground-level area sources in a dairy operation in central Texas.  

PubMed

Although there are more than 200 odor-causing volatile organic compounds (VOCs), phenol and p-cresol are two prominent odor-causing VOCs found downwind from concentrated animal feeding operations (CAFOs). The VOC emissions from cattle and dairy production are difficult to quantify accurately because of their low concentrations, spatial variability, and limitations of available instruments. To quantify VOCs, a protocol following US. Environmental Protection Agency (EPA) Method TO-14A has been established based on the isolation flux chamber method and a portable gas chromatograph (GC) coupled with a purge-and-trap system. The general objective of this research was to quantify phenol and p-cresol emission rates (ERs) from different ground-level area sources (GLASs) in a free-stall dairy during summer and winter seasons using this protocol. Two-week-long sampling campaigns were conducted in a dairy operation in central Texas. Twenty-nine air samples were collected during winter and 37 samples were collected during summer from six specifically delineated GLASs (barn, loafing pen, lagoon, settling basin, silage pile, and walkway) at the free-stall dairy. Thirteen VOCs were identified during the sampling period and the GC was calibrated for phenol and p-cresol, the primary odorous VOCs identified. The overall calculated ERs for phenol and p-cresol were 2656 +/- 728 and 763 +/- 212 mg hd(-1) day(-1), respectively, during winter. Overall phenol and p-cresol ERs were calculated to be 1183 +/- 361 and 551 +/- 214 mg hd(-1) day(-1), respectively, during summer. In general, overall phenol and p-cresol ERs during winter were about 2.3 and 1.4 times, respectively, higher than those during summer. PMID:22616280

Borhan, M S; Capareda, S; Mukhtar, S; Faulkner, W B; McGee, R; Parnell, C B

2012-04-01

260

Comparison of emission ratios from on-road sources using a mobile laboratory under various driving and operational sampling modes  

NASA Astrophysics Data System (ADS)

Mobile sources produce a significant fraction of the total anthropogenic emissions burden in large cities and have harmful effects on air quality at multiple spatial scales. Mobile emissions are intrinsically difficult to estimate due to the large number of parameters affecting the emissions variability within and across vehicles types. The MCMA-2003 Campaign in Mexico City has showed the utility of using a mobile laboratory to sample and characterize specific classes of motor vehicles to better quantify their emissions characteristics as a function of their driving cycles. The technique clearly identifies "high emitter" vehicles via individual exhaust plumes, and also provides fleet average emission rates. We have applied this technique to Mexicali during the Border Ozone Reduction and Air Quality Improvement Program for the Mexicali-Imperial Valley in 2005. In this paper we analyze the variability of measured emission ratios for emitted NOx, CO, specific VOCs, NH3, and some primary fine particle components and properties obtained during the Border Ozone Reduction and Air Quality Improvement Program for the Mexicali-Imperial Valley in 2005 by deploying a mobile laboratory in roadside stationary sampling, chase and fleet average operational sampling modes. The measurements reflect various driving modes characteristic of the urban fleets. The observed variability for all measured gases and particle emission ratios is greater for the chase and roadside stationary sampling than for fleet average measurements. The fleet average sampling mode captured the effects of traffic conditions on the measured on-road emission ratios, allowing the use of fuel-based emission ratios to assess the validity of traditional "bottom-up" emissions inventories. Using the measured on-road emission ratios, we estimate CO and NOx mobile emissions of 175±62 and 10.4±1.3 metric tons/day, respectively, for the gasoline vehicle fleet in Mexicali. Comparisons with similar on-road emissions data from Mexico City indicated that fleet average NO emission ratios were around 20% higher in Mexicali than in Mexico City whereas HCHO and NH3 emission ratios were higher by a factor of 2 in Mexico City than in Mexicali. Acetaldehyde emission ratios did not differ significantly whereas selected aromatics VOCs emissions were similar or smaller in Mexicali. On-road heavy-duty diesel truck (HDDT) nitrogen oxides emissions were measured near Austin, Texas, as well as in both Mexican cities, with NOy emission ratios in Austin < Mexico City < Mexicali.

Zavala, M.; Herndon, S. C.; Wood, E. C.

2008-04-01

261

Comparison of emissions from on-road sources using a mobile laboratory under various driving and operational sampling modes  

NASA Astrophysics Data System (ADS)

Mobile sources produce a significant fraction of the total anthropogenic emissions burden in large cities and have harmful effects on air quality at multiple spatial scales. Mobile emissions are intrinsically difficult to estimate due to the large number of parameters affecting the emissions variability within and across vehicles types. The MCMA-2003 Campaign in Mexico City has showed the utility of using a mobile laboratory to sample and characterize specific classes of motor vehicles to better quantify their emissions characteristics as a function of their driving cycles. The technique clearly identifies "high emitter" vehicles via individual exhaust plumes, and also provides fleet average emission rates. We have applied this technique to Mexicali during the Border Ozone Reduction and Air Quality Improvement Program (BORAQIP) for the Mexicali-Imperial Valley in 2005. We analyze the variability of measured emission ratios for emitted NOx, CO, specific VOCs, NH3, and some primary fine particle components and properties by deploying a mobile laboratory in roadside stationary sampling, chase and fleet average operational sampling modes. The measurements reflect various driving modes characteristic of the urban fleets. The observed variability for all measured gases and particle emission ratios is greater for the chase and roadside stationary sampling than for fleet average measurements. The fleet average sampling mode captured the effects of traffic conditions on the measured on-road emission ratios, allowing the use of fuel-based emission ratios to assess the validity of traditional "bottom-up" emissions inventories. Using the measured on-road emission ratios, we estimate CO and NOx mobile emissions of 175±62 and 10.4±1.3 metric tons/day, respectively, for the gasoline vehicle fleet in Mexicali. Comparisons with similar on-road emissions data from Mexico City indicated that fleet average NO emission ratios were around 20% higher in Mexicali than in Mexico City whereas HCHO and NH3 emission ratios were higher by a factor of 2 in Mexico City than in Mexicali. Acetaldehyde emission ratios did not differ significantly whereas selected aromatics VOCs emissions were similar or smaller in Mexicali. Nitrogen oxides emissions for on-road heavy-duty diesel truck (HDDT) were measured near Austin, Texas, as well as in both Mexican cities, with NOy emission ratios in Austin < Mexico City < Mexicali.

Zavala, M.; Herndon, S. C.; Wood, E. C.; Jayne, J. T.; Nelson, D. D.; Trimborn, A. M.; Dunlea, E.; Knighton, W. B.; Mendoza, A.; Allen, D. T.; Kolb, C. E.; Molina, M. J.; Molina, L. T.

2009-01-01

262

Contribution Of Unresolved Point Sources To The Galactic Diffuse Emission  

Microsoft Academic Search

A major difficulty when studying the high energy gamma ray diffuse emission from the Galaxy is to disantangle the truly diffuse emission from that produced by unresolved sources. The detection by the HESS atmospheric Cherenkov telescope of eighteen new sources from the Galactic plane makes it possible to estimate the contribution of unresolved point sources like those detected by HESS

Sabrina Casanova; Brenda L. Dingus

2006-01-01

263

A Cherenkov-emission Microwave Source.*  

NASA Astrophysics Data System (ADS)

In an unmagnetized plasma, there is no Cherenkov emission because the phase velocity ?_? of light is greater than c. In a magnetized plasma, the situation is completely changed. There is a rich variety of plasma modes with phase velocities ?_? <= c which can couple to a fast particle. In the magnetized plasma, a fast particle, a particle beam, or even a short laser pulse excites a Cherenkov wake that has both electrostatic and electromagnetic components. Preliminary simulations indicate that at the vacuum/plasma boundary, the wake couples to a vacuum microwave with an amplitude equal to the electromagnetic component in the plasma. For a weakly magnetized plasma, the amplitude of the out-coupled radiation is approximately ?c / ?p times the amplitude of the wake excited in the plasma by the beam, and the frequency is approximately ?_p. Since plasma wakes as high as a few GeV/m are produced in current experiments, the potential for a high-power (i.e., GWatt) coherent microwave to THz source exists. In this talk, a brief overview of the scaling laws will be presented, followed by 1-D and 2-D PIC simulations. Prospects for a tuneable microwave source experiment based on this mechanism at the UCLA plasma wakefield accelerator facility will be discussed. Work supported by AFOSR Grant #F4 96200-95-0248 and DOE Grant # DE-FG03-92ER40745. ^1Now at Hughes Research Laboratories, Malibu, CA 90265.

Lai, C. H.; Yoshii, J.; Katsouleas, T.; Hairapetian, G.; Joshi, C.; Mori, W.

1996-11-01

264

A Cherenkov-emission Microwave Source*  

NASA Astrophysics Data System (ADS)

In an unmagnetized plasma, there is no Cherenkov emission because the phase velocity vf of light is greater than c. In a magnetized plasma, the situation is completely changed. There is a rich variety of plasma modes with phase velocities vf 2 c which can couple to a fast particle. In the magnetized plasma, a fast particle, a particle beam, or even a short laser pulse excites a Cherenkov wake that has both electrostatic and electromagnetic components. Preliminary simulations indicate that at the vacuum/plasma boundary, the wake couples to a vacuum microwave with an amplitude equal to the electromagnetic component in the plasma. For a weakly magnetized plasma, the amplitude of the out-coupled radiation is approximately wc/wp times the amplitude of the wake excited in the plasma by the beam, and the frequency is approximately wp. Since plasma wakes as high as a few GeV/m are produced in current experiments, the potential for a high-power (i.e., GWatt) coherent microwave to THz source exists. In this talk, a brief overview of the scaling laws will be presented, followed by 1-D and 2-D PIC simulations. Prospects for a tuneable microwave source experiment based on this mechanism at the UCLA plasma wakefield accelerator facility will be discussed. *Work supported by AFOSR Grant #F4 96200-95-0248 and DOE Grant # DE-FG03-92ER40745. 1Now at Hughes Research Laboratories, Malibu, CA 90265

Lai, C. H.; Yoshii, J.; Katsouleas, T.; Hairapetian1, G.; Joshi, C.; Mori, W.

1996-11-01

265

Comparison of Seasonal Phenol and p-cresol Emissions from Ground Level Area Sources in a Dairy Operation in Central Texas  

Microsoft Academic Search

While there are more than 200 odor-causing volatile organic compounds (VOCs), phenol and p-cresol are two prominent odor-causing VOCs found downwind from concentrated animal feeding operations (CAFOs). The VOC emissions from cattle and dairy production are difficult to quantify accurately because of their low concentrations, spatial variability, and limitations of available instruments. To quantify VOCs, a protocol following EPA method

M. S. Borhan; S. Capareda; S. Mukhtar; W. B. Faulkner; R. McGee; C. B. Parnell Jr

2011-01-01

266

Comparison of seasonal phenol and p-cresol emissions from ground-level area sources in a dairy operation in central Texas  

Microsoft Academic Search

Although there are more than 200 odor-causing volatile organic compounds (VOCs), phenol and p-cresol are two prominent odor-causing VOCs found downwind from concentrated animal feeding operations (CAFOs). The VOC emissions from cattle and dairy production are difficult to quantify accurately because of their low concentrations, spatial variability, and limitations of available instruments. To quantify VOCs, a protocol following U.S. Environmental

M. S. Borhan; S. Capareda; S. Mukhtar; W. B. Faulkner; R. McGee; C. B. Parnell Jr

2012-01-01

267

GLYCOL DEHYDRATOR BTEX AND VOC EMISSIONS TESTING RESULTS AT TWO UNITS IN TEXAS AND LOUISIANA - VOLUME I. TECHNICAL REPORT  

EPA Science Inventory

The report gives results of the collection of emissions tests data at two triethylene glycol (TEG) units to provide data for comparison to GRI-GLYCalc, a computer program developed to estimate emissions from glycol dehydrators. (NOTE: Glycol dehydrators are used in the natural ga...

268

GLYCOL DEHYDRATOR BTEX AND VOC EMISSIONS TESTING RESULTS AT TWO UNITS IN TEXAS AND LOUISIANA - VOLUME II. APPENDICES  

EPA Science Inventory

The report gives results of the collection of emissions tests data at two triethylene glycol (TEG) units to provide data for comparison to GRI-GLYCalc, a computer program developed to estimate emissions from glycol dehydrators. (NOTE: Glycol dehydrators are used in the natural ga...

269

Constraining Emission Models of Luminous Blazar Sources  

SciTech Connect

Many luminous blazars which are associated with quasar-type active galactic nuclei display broad-band spectra characterized by a large luminosity ratio of their high-energy ({gamma}-ray) and low-energy (synchrotron) spectral components. This large ratio, reaching values up to 100, challenges the standard synchrotron self-Compton models by means of substantial departures from the minimum power condition. Luminous blazars have also typically very hard X-ray spectra, and those in turn seem to challenge hadronic scenarios for the high energy blazar emission. As shown in this paper, no such problems are faced by the models which involve Comptonization of radiation provided by a broad-line-region, or dusty molecular torus. The lack or weakness of bulk Compton and Klein-Nishina features indicated by the presently available data favors production of {gamma}-rays via up-scattering of infrared photons from hot dust. This implies that the blazar emission zone is located at parsec-scale distances from the nucleus, and as such is possibly associated with the extended, quasi-stationary reconfinement shocks formed in relativistic outflows. This scenario predicts characteristic timescales for flux changes in luminous blazars to be days/weeks, consistent with the variability patterns observed in such systems at infrared, optical and {gamma}-ray frequencies. We also propose that the parsec-scale blazar activity can be occasionally accompanied by dissipative events taking place at sub-parsec distances and powered by internal shocks and/or reconnection of magnetic fields. These could account for the multiwavelength intra-day flares occasionally observed in powerful blazars sources.

Sikora, Marek; /Warsaw, Copernicus Astron. Ctr.; Stawarz, Lukasz; /Kipac, Menlo Park /Jagiellonian U., Astron. Observ. /SLAC; Moderski, Rafal; Nalewajko, Krzysztof; /Warsaw, Copernicus Astron. Ctr.; Madejski, Greg; /KIPAC, Menlo Park /SLAC

2009-10-30

270

Source Emissions in Multipollutant Air Quality Management  

Microsoft Academic Search

\\u000a This chapter discusses emissions inventories and emission control technologies in the context of a risk-based, results-oriented\\u000a multipollutant air quality management program. As contemporary emission control technologies often achieve reductions in more\\u000a than one pollutant, the chapter reviews major emissions reduction in North America as examples of multipollutant reduction\\u000a strategies for both criteria pollutants and air toxics. The chapter then comments

C. Andrew Miller

271

World Calibration Center for VOC (WCC-VOC), a new Facility for the WMO-GAW-Programme  

NASA Astrophysics Data System (ADS)

Volatile organic compounds (VOC) are recognized to be important precursors of tropospheric ozone as well as other oxidants and organic aerosols. In order to design effective control measures for the reduction of photooxidants, photochemical processes have to be understood and the sources of the precursors known. Reliable and representative measurements of VOCs are necessary to describe the anthropogenic and biogenic sources, to follow the photochemical degradation of VOCs in the troposphere. Measurement of VOCs is of key importance for the understanding of tropospheric chemistry. Tropospheric VOCs have been one of the recommended measurements to be made within the GAW programme. The purpose will be to monitor their atmospheric abundance, to characterize the various compounds with regard to anthropogenic and biogenic sources and to evaluate their role in the tropospheric ozone formation process. An international WMO/GAW panel of experts for VOC measurements developed the rational and objectives for this GAW activity and recommended the configuration and required activities of the WCC-VOC. In reflection of the complexity of VOC measurements and the current status of measurement technology, a "staged" approach was adopted. Stage 1 measurements: C2-C9 hydrocarbons, including alkanes, alkenes, alkynes, dienes and monocyclics. (The WCC-VOC operates currently under this mode). Stage 2 measurements: C10-C14 hydrocarbons, including higher homologs of the Stage 1 set as well as biogenic hydrocarbon compounds. Stage 3 measurements: Oxygenated VOCs, including alcohols, carbonyls, carboxylic acids. The Quality Assurance/Science Activity Centre (QA/SAC) Germany currently has established the World Calibration Centre for VOC (WCC-VOC). The WCC-VOC has operated in the research mode und has become operational recently. From now on, the WCC-VOC conducts one round-robin calibration audit per year at all global stations that measure VOCs and assists other stations in setting up VOC measurement capabilities. Furthermore, the WCC-VOC will promote inter-com-parison experiments with networks related to other programmes, notably EMEP and IGAC.

Rappenglueck, B.-

2002-12-01

272

Identification and Characterization of Missing or Unaccounted for Area Source Categories.  

National Technical Information Service (NTIS)

The report identifies and characterizes missing or unaccounted for area source categories. Area source emissions of particulate matter (TSP), sulfur dioxide (SO2), oxides of nitrogen (NOx), reactive volatile organic compounds (VOCs), and carbon monoxide (...

A. Chadha B. Henning D. J. Zimmerman P. R. Cawkwell S. L. Kersteter

1992-01-01

273

SOURCES, EMISSION AND EXPOSURE TO TRICHLOROETHYLENE (TCE) AND RELATED CHEMICALS  

EPA Science Inventory

This report documents the sources, emission, environmental fate and exposures for TCE, some of its metabolites, and some other chemicals known to produce identical metabolites. The major findings for TCE are: The primary sources releasing TCE to the environment ...

274

Proton emission from a laser ion source  

NASA Astrophysics Data System (ADS)

At intensities of the order of 1010 W/cm2, ns pulsed lasers can be employed to ablate solid bulk targets in order to produce high emission of ions at different charge state and kinetic energy. A special interest is devoted to the production of protons with controllable energy and current from a roto-translating target irradiated in repetition rate at 1-10 Hz by a Nd:Yag pulsed laser beam. Different hydrogenated targets based on polymers and hydrates were irradiated in high vacuum. Special nanostrucutres can be embedded in the polymers in order to modify the laser absorption properties and the amount of protons to be accelerated in the plasma. For example, carbon nanotubes may increase the laser absorption and the hydrogen absorption to generate high proton yields from the plasma. Metallic nanostrucutres may increase the electron density of the plasma and the kinetic energy of the accelerated protons. Ion collectors, ion energy analyzer, and mass spectrometers, used in time-of-flight configuration, were employed to characterize the ion beam properties. A comparison with traditional proton ion source is presented and discussed.

Torrisi, L.; Cavallaro, S.; Cutroneo, M.; Margarone, D.; Gammino, S.

2012-02-01

275

Proton emission from a laser ion source  

SciTech Connect

At intensities of the order of 10{sup 10} W/cm{sup 2}, ns pulsed lasers can be employed to ablate solid bulk targets in order to produce high emission of ions at different charge state and kinetic energy. A special interest is devoted to the production of protons with controllable energy and current from a roto-translating target irradiated in repetition rate at 1-10 Hz by a Nd:Yag pulsed laser beam. Different hydrogenated targets based on polymers and hydrates were irradiated in high vacuum. Special nanostrucutres can be embedded in the polymers in order to modify the laser absorption properties and the amount of protons to be accelerated in the plasma. For example, carbon nanotubes may increase the laser absorption and the hydrogen absorption to generate high proton yields from the plasma. Metallic nanostrucutres may increase the electron density of the plasma and the kinetic energy of the accelerated protons. Ion collectors, ion energy analyzer, and mass spectrometers, used in time-of-flight configuration, were employed to characterize the ion beam properties. A comparison with traditional proton ion source is presented and discussed.

Torrisi, L. [INFN-LNS Via S. Sofia 44, 95123 Catania (Italy); Dip.to di Fisica, Universita di Messina, V.le F.S. D'Alcontres 31, 98166 S. Agata, Messina (Italy); Cavallaro, S.; Gammino, S. [INFN-LNS Via S. Sofia 44, 95123 Catania (Italy); Cutroneo, M. [Dip.to di Fisica, Universita di Messina, V.le F.S. D'Alcontres 31, 98166 S. Agata, Messina (Italy); Margarone, D. [Institute of Physics, ASCR, v.v.i., 182 21 Prague 8 (Czech Republic)

2012-02-15

276

Biogenic VOC Emissions Measured by Solid Phase Microextraction (SPME) Fibers, Proton Transfer Reaction Mass Spectrometry (PTR-MS), and In-situ Gas Chromatography (GC)  

Microsoft Academic Search

Chemical ozone loss due to reactions with biogenic VOCs has been shown to dominate ozone flux measured at Blodgett Forest, a coniferous forest in the Sierra Nevada Mountains of California. Here we report recent efforts to measure the specific biogenic VOCs involved in this chemistry at Blodgett Forest. During summer 2005, we enclosed branches of Ponderosa pine, manzanita, and ceanothus

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

2005-01-01

277

RESEARCH AREA -- STATIONARY SOURCE EMISSIONS CHARACTERIZATION (EMISSIONS CHARACTERIZATION AND PREVENTION BRANCH, APPCD, NRMRL)  

EPA Science Inventory

Research and development of models to estimate emissions from dynamic oil and gas industry and commercial sources is the objective of this program. The Emission Characterization and Prevention Branch, the American Petroleum Institute, and the Gas Research Institute have jointly ...

278

Locating and estimating air emissions from sources of phosgene  

SciTech Connect

To assist groups interested in inventorying air emissions of various potentially toxic substances, EPA is preparing a series of documents such as this to compile available information on sources and emissions of these substances. This document deals specifically with phosgene. Its intended audience includes Federal, State and local air pollution personnel and others interested in locating potential emitters of phosgene in making gross estimates of air emissions therefrom. This document presents information on (1) the types of sources that may emit phosgene, (2) process variations and release points that may be expected within these sources, and (3) available emissions information indicating the potential for phosgene release into the air from each operation.

Not Available

1985-09-01

279

VOC Control in Kraft Mills  

SciTech Connect

The formation of volatile organic compounds (VOCs), such as methanol, in kraft mills has been an environmental concern. Methanol is soluble in water and can increase the biochemical oxygen demand. Furthermore, it can also be released into atmosphere at the process temperatures of kraft mill-streams. The Cluster Rule of the EPA now requires the control of the release of methanol in pulp and paper mills. This research program was conducted to develop a computer simulation tool for mills to predict VOC air emissions. To achieve the objective of the research program, much effort was made in the development of analytical techniques for the analysis of VOC and determination of vapor liquid partitioning coefficient of VOCs in kraft mill-streams using headspace gas chromatography. With the developed analytical tool, methanol formation in alkaline pulping was studied in laboratory to provide benchmark data of the amount of methanol formation in pulping in kraft mills and for the validation of VOC formation and vapor-liquid equilibrium submodels. Several millwide air and liquid samplings were conducted using the analytical tools developed to validate the simulation tool. The VOC predictive simulation model was developed based on the basic chemical engineering concepts, i.e., reaction kinetics, vapor liquid equilibrium, combined with computerized mass and energy balances. Four kraft mill case studies (a continuous digester, two brownstock washing lines, and a pre-evaporator system) are presented and compared with mill measurements. These case studies provide valuable, technical information for issues related to MACT I and MACT II compliance, such as condensate collection and Clean-Condensate-Alternatives (CCA).

Zhu, J.Y.; Chai, X.-S.; Edwards, L.L.; Gu, Y.; Teja, A.S.; Kirkman, A.G.; Pfromm, P.H.; Rezac, M.E.

2001-09-26

280

Area Source Emission Measurements Using EPA OTM 10  

EPA Science Inventory

Measurement of air pollutant emissions from area and non-point sources is an emerging environmental concern. Due to the spatial extent and non-homogenous nature of these sources, assessment of fugitive emissions using point sampling techniques can be difficult. To help address th...

281

REGIONAL AIR POLLUTION STUDY. POINT SOURCE EMISSION INVENTORY  

EPA Science Inventory

Emission data from stationary point sources in the St. Louis Interstate Air Quality Control Region were gathered during 1975. Data for 'criteria' pollutants were obtained on an hourly basis. Emissions from large sources were based on hourly, measured values at pertinent operating...

282

Development of a combined real time monitoring and integration analysis system for volatile organic compounds (VOCs).  

PubMed

A combined integration analysis and real time monitoring (Peak Capture System) system was developed for volatile organic compounds (VOCs). Individual integration analysis and real time monitoring can be used to qualitatively and quantitatively analyze VOCs in the atmosphere and in indoor environments and determine the variation in total VOC (TVOC) concentration with time, respectively. In the Peak Capture System, real time monitoring was used to predict future elevations in the TVOC concentration (peak), and this was used an indicator of when to collect (capture) ambient air samples for integration analysis. This enabled qualitative and quantitative analysis of VOCs when the TVOC concentration was high. We developed an algorithm to predict variation in the TVOC concentration, and constructed an automatic system to initiate air sampling for integration analysis. With the system, auto-sampling and analysis of VOCs in a conventional house were conducted. In comparison with background concentrations, the results of peak analysis enabled identification of compounds whose concentration rose. This also enabled an evaluation of possible VOC emission sources. PMID:21317996

Oka, Kentaro; Iizuka, Atsushi; Inoue, Yasuo; Mizukoshi, Atsushi; Noguchi, Miyuki; Yamasaki, Akihiro; Yanagisawa, Yukio

2010-11-26

283

Development of a Combined Real Time Monitoring and Integration Analysis System for Volatile Organic Compounds (VOCs)  

PubMed Central

A combined integration analysis and real time monitoring (Peak Capture System) system was developed for volatile organic compounds (VOCs). Individual integration analysis and real time monitoring can be used to qualitatively and quantitatively analyze VOCs in the atmosphere and in indoor environments and determine the variation in total VOC (TVOC) concentration with time, respectively. In the Peak Capture System, real time monitoring was used to predict future elevations in the TVOC concentration (peak), and this was used an indicator of when to collect (capture) ambient air samples for integration analysis. This enabled qualitative and quantitative analysis of VOCs when the TVOC concentration was high. We developed an algorithm to predict variation in the TVOC concentration, and constructed an automatic system to initiate air sampling for integration analysis. With the system, auto-sampling and analysis of VOCs in a conventional house were conducted. In comparison with background concentrations, the results of peak analysis enabled identification of compounds whose concentration rose. This also enabled an evaluation of possible VOC emission sources.

Oka, Kentaro; Iizuka, Atsushi; Inoue, Yasuo; Mizukoshi, Atsushi; Noguchi, Miyuki; Yamasaki, Akihiro; Yanagisawa, Yukio

2010-01-01

284

Contribution Of Unresolved Point Sources To The Galactic Diffuse Emission.  

NASA Astrophysics Data System (ADS)

A major difficulty when studying the high energy gamma ray diffuse emission from the Galaxy is to disantangle the truly diffuse emission from that produced by unresolved sources. The detection by the HESS atmospheric Cherenkov telescope of eighteen new sources from the Galactic plane makes it possible to estimate the contribution of unresolved point sources like those detected by HESS to the diffuse emission measured by EGRET and recently at higher energies by the Milagro Collaboration. Assuming that HESS sources have all the same intrinsic luminosity, the contribution of this new source population can account for most of the Milagro gamma-ray emission at TeV energies and for less than 10 per cent of EGRET diffuse galactic gamma-ray emission at GeV energies. Also, by combining the HESS and the Milagro results, constraints can be put on the distribution of gamma ray emitters in the Galaxy and on their luminosity.

Casanova, Sabrina; Dingus, B. L.

2006-09-01

285

Compost spreading in Mediterranean shrubland indirectly increases biogenic emissions by promoting growth of VOC-emitting plant parts  

Microsoft Academic Search

We investigated the effect of sewage sludge compost spreading on plant growth and leaf terpene emissions and content of Quercus coccifera, Rosmarinus officinalis and Cistus albidus in a Mediterranean shrubland. Measurements were performed during 3 consecutive summers on 2 different plots treated in 2002 or 2007 with 50 or 100 tons of compost per hectare, corresponding to observations carried out

Romain Olivier; Anne-Violette Lavoir; Elena Ormeño; Florent Mouillot; Stéphane Greff; Caroline Lecareux; Michael Staudt; Catherine Fernandez

2011-01-01

286

Compost spreading in Mediterranean shrubland indirectly increases biogenic emissions by promoting growth of VOC-emitting plant parts  

NASA Astrophysics Data System (ADS)

We investigated the effect of sewage sludge compost spreading on plant growth and leaf terpene emissions and content of Quercus coccifera, Rosmarinus officinalis and Cistus albidus in a Mediterranean shrubland. Measurements were performed during 3 consecutive summers on 2 different plots treated in 2002 or 2007 with 50 or 100 tons of compost per hectare, corresponding to observations carried out 2 months to 7 years after spreading. A slight nutrient enrichment of soil and leaves ( R. officinalis and C. albidus) was observed, especially for phosphorous. Terpene emissions were not affected by compost spreading, although they tended to increase on treated plots after 6 and 7 years for R. officinalis and C. albidus respectively. Terpene content was not affected by any compost treatment. Leaf and stem growth were significantly enhanced by compost spreading after 2 and/or 7 years in all species with little difference between doses. Total leaf biomass on the last growth units was increased by more than 50% in C. albidus and more than 90% in Q. coccifera. The results suggest that compost spreading in Meditteranean shrublands has no or little direct effect on leaf terpene emissions, but indirectly leads to their increase through leaf biomass enhancement. Simulation of terpene emissions at stand level revealed an increase of terpene fluxes ranging between 6 and 13%, depending on the plant species. Overall, compost spreading was assessed to result in an emission rate of 1.1 kg ha -1 y -1 for a typical Q. coccifera shrubland, but can reach 2.6 kg ha -1 y -1 for a typical R. officinalis shrubland.

Olivier, Romain; Lavoir, Anne-Violette; Ormeño, Elena; Mouillot, Florent; Greff, Stéphane; Lecareux, Caroline; Staudt, Michael; Fernandez, Catherine

2011-07-01

287

Measurements of Volatile Organic Compounds (VOCs) on Board of the Zeppelin NT during the PEGASOS Campaign in 2012  

NASA Astrophysics Data System (ADS)

Volatile Organic Compounds (VOCs) are mostly emitted at the ground and are degraded by the reactions with OH, NO3 or O3 as they rise upwards in the atmosphere. VOCs play an important role as sources and sinks for radicals in the troposphere. Up to date, most of the VOC measurements were performed from ground based platforms; the profile measurements across the whole planetary boundary layer (PBL) are still quite limited which restrained the exploring of the VOCs chemistry of the entire PBL. This although these measurements are particularly interesting, as most of the chemistry of the VOC degradation in the troposphere takes place in the PBL. Moreover, fast VOCs measurements utilizing Gas Chromatography coupled with Mass Spectrometry (GC-MS) are a challenge due to the great chemical variability of VOC species. Therefore accurate in-situ measurements of VOCs together with other species as CO, NOx, O3 and the OH reactivity, encompassing different levels of altitude and fast time resolution, would essentially improve the understanding of the VOC distribution in the lower troposphere. Here we present the setup and the modifications of the fast GC-MS system and the results of the PEGASOS Zeppelin campaigns in summer 2012. First, we present our developments and modifications of an in-flight GC-MS system to detect volatile non methane hydrocarbons (NMHC) with a time resolution of 3 minutes and a detection limit in the order of 2 pptv. The modified setup enabled us to analyze 70 different VOC species, ranging from alkanes (C4 to C11), aromatics and terpenes to oxygenated hydrocarbons (OVOC) such as alcohols and aldehydes. Second, in contrast to previous airplane studies also utilizing a GC-MS system, the Zeppelin NT as a measuring platform during the PEGASOS campaign enabled us to measure vertical profiles up to 1500m at low travelling speeds which means a high spatial resolution. We will present results for selected VOC that offer new insights on height profiles encompassing different emission regimes (anthropogenic and biogenic) in both the Netherlands and in Italy, and on the fate of VOCs in the nocturnal boundary layer. Third, we also present how the VOC concentrations relate to other substances such as CO, NOx, O3 and the OH reactivity. Especially the comparison of VOC Data with the measured OH reactivity will reveal more insight into the 'missing reactivity'. Acknowledgement: PEGASOS project funded by the European Commission under the Framework Program 7 (FP7-ENV-2010-265148)

Jäger, Julia; Hofzumahaus, Andreas; Beck, Harry; Rohrer, Franz; Broch, Sebastian; Fuchs, Hendrik; Gomm, Sebastian; Holland, Frank; Lu, Keding; Kiendler-Scharr, Astrid; Mentel, Thomas; Rose, Bernhard; Wegener, Robert; Wahner, Andreas

2013-04-01

288

Dry Sources of Plume Emissions on Enceladus  

NASA Astrophysics Data System (ADS)

Salt-bearing icy particles [1], inorganic gases [2] and organic species [2,3] emitted from Enceladus could originate in the heterogeneous icy shell that captured oceanic water and primordial solids earlier in history. A major trapping could have occurred during sinking of a dense (1.6 g/cm3) primordial rock-ice crust [4] into an early salt-, gas- and organic-bearing ocean [5]. The lack of spectral and geological signs for rocky components at the surface is consistent with the submergence of primordial crust that has not been affected by initial water-rock differentiation. The sinking could have been triggered by impacts and/or volume changes in the interior. A rapid submergence could have caused vigorous boiling and freezing of oceanic water that appeared at the surface. The low temperature of submerged crust, and cooling of surface waters may have limited major melting of sunken rock-ice blocks. Some primary spices (e.g. HCN [2]), if released from sunken rock-ice debris, could have been re-captured in ice, which limited their chemical interactions. After formation of a thin icy shell, diking events and impacts caused further trapping of salty oceanic water in multiple disrupted areas, as occurred on Europa. Condensed and soluble organic compounds, and at least some CO2, N2, CH4 and light hydrocarbons released via oceanic degassing were trapped as well. The concentration of salts in rapidly frozen oceanic water reflected oceanic composition, and the salt/water ratio in Na-rich E-ring particles [1] may represent salinity of the early ocean. In fact, the salinity inferred from the composition of salt-rich particles (4-20 g/kg H2O [1]) and salt composition matches models for the early ocean [5]. The Na-poor E-ring particles [1] may originate from a middle part of the icy shell that formed through slow downward freezing and expelling impurities into solution. The dominance of Na-poor E-ring icy grains (~93%, [1]) implies a low volume of salty ice that represents rapidly frozen early oceanic water. A lack of highly saline particles in E ring that are expected to form due to significant evaporation of an aqueous reservoir also argues for dry sources. The E-ring grains [1,3] may represent neither thick salt deposits at the core-ice boundary nor brines that may exist at that boundary today [5]. A low upper limit for atomic Na content at Enceladus [6] is consistent with Na emission in salt particles from dry sources. A low (far from eutectic) NH3/H2O ratio in plumes [2] implies dry sources as well. If present, primary species (e.g. NH3, HCN) in plums [2] and Mg silicates in E-ring particles [3] could originate from unmelted fragments of sunken primordial crust that have been incorporated into the formed icy shell. The structural heterogeneity of current icy shell may account for the chemical diversity of gases [2] and solids [1,3] emitted from Enceladus. Refs.: [1] Portberg F. et al. (2009) Nature 459, 1098-1101. [2] Waite J. et al. et al. (2009) Nature 460, 487-490. [3] Postberg F. et al. (2008) Icarus 193, 438-454. [4] Schubert G. et al. (2007) Icarus 188, 335-345. [5] Zolotov M. (2007) GRL 34, L23203. [6] Schneider N. et al. (2009) Nature 459, 1098-1101.

Zolotov, M. Y.

2009-12-01

289

Applicability of gasoline containing ethanol as Thailand's alternative fuel to curb toxic VOC pollutants from automobile emission  

Microsoft Academic Search

Emission rates of benzene, toluene, m-xylene, formaldehyde and acetaldehyde were measured in a fleet of 16 in-use vehicles. The test was performed on a chassis dynamometer incorporated with Bangkok Driving Cycle test mode. Three different test fuels: unleaded gasoline, gasoline blended with 10% ethanol (E10) and gasoline blended with 15% ethanol (E15) were used to determine the different compositions of

Shing Tet Leong; S Muttamara; Preecha Laortanakul

2002-01-01

290

Extended emission sources observed via two-proton correlations  

SciTech Connect

Two-particle correlations between light particles emitted in heavy-ion reactions may be used to extract information on the spatial extent and time development of the emission source. Such measurements have provided evidence for the formation and decay of localized regions of high excitation. An interesting aspect of these measurements is the observation that the less energetic particles are emitted from sources of larger apparent dimensions. This has been interpreted as an indication that the lower energy particles are emitted at a later, more equilibrated stage of the reaction. As originally pointed out by Koonin, the dependence of the two-particle correlation on the direction of the relative momentum, with respect to the direction of emission, may provide information on the source lifetime and shape. Although spatial and temporal effects are not strictly distinguishable, a long-lived spherical emission source will have a characteristically prolate appearance, elongated in the direction of emission. We present an analysis of the directional dependence of the two-proton correlation function and extract the shape of the proton emission source. The source shape is observed to vary from that of the compound nucleus for the emission of energetic protons to an extended spherical shape for the emission of low-energy protons, contrary to expectations for a long-lived evaporative source of compound nucleus dimensions. 2 figs.

Awes, T.C.; Ferguson, R.L.; Obenshain, F.E.; Plasil, F.; Young, G.R.; Pratt, S.; Chen, Z.; Gelbke, C.K.; Lynch, W.G.; Pochodzalla, J.

1989-01-01

291

Removal of VOCs from air by membrane-based absorption and stripping  

Microsoft Academic Search

Atmospheric emission of volatile organic compounds (VOCs) such as toluene, xylene, acetone etc. from industrial facilities causes serious environmental problems and financial losses. Existing technologies for VOC emission abatement have many strengths as well as considerable limitations. A regenerative absorption-based process for removal of VOCs from N2 in an inert, nonvolatile, organic liquid flowing in compact hollow fiber devices has

Tarun K. Poddar; Sudipto Majumdar; Kamalesh K. Sirkar

1996-01-01

292

Coherent emission of light by thermal sources  

Microsoft Academic Search

A thermal light-emitting source, such as a black body or the incandescent filament of a light bulb, is often presented as a typical example of an incoherent source and is in marked contrast to a laser. Whereas a laser is highly monochromatic and very directional, a thermal source has a broad spectrum and is usually quasi-isotropic. However, as is the

Jean-Jacques Greffet; Rémi Carminati; Karl Joulain; Jean-Philippe Mulet; Stéphane Mainguy; Yong Chen

2002-01-01

293

Sensitivity analysis of tropospheric ozone to modified biogenic emissions for the Mid-Atlantic region  

Microsoft Academic Search

Biogenic sources contribute a large portion of emissions of volatile organic compounds (VOCs), a precursor to tropospheric ozone (O3). These emissions are difficult to control and are affected by land-use and climate. A sensitivity analysis was performed using an emissions scenario with a 100% increase in biogenic emissions and another scenario with an additional 100% increase in motor vehicle emissions.

Michelle Bell; Hugh Ellis

2004-01-01

294

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

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

295

Intelligent location of simultaneously active acoustic emission sources: Part I  

Microsoft Academic Search

The intelligent acoustic emission (AE) locator is described in Part I while Part II discusses a blind source separation, time delay estimation and location of two simultaneously active continuous AE sources. Location of AE on complicated aircraft frame structures is a difficult problem of non-destructive testing. In this article an intelligent AE source locator is described. The intelligent locator is

Tadej Kosel; Igor Grabec; Franc Kosel

2003-01-01

296

Characterization of Industrial Emission Sources and Photochemistry in Houston, Texas  

NASA Astrophysics Data System (ADS)

The Houston-Galveston urban area contains a number of large industrial petrochemical emission sources that produce volatile organic compounds and nitrogen oxides. These co-located emissions result in rapid and efficient ozone production downwind. Unlike a single large power plant, the industrial complexes consist of numerous sources that can be difficult to quantify in emission inventories. During September - October 2006, the NOAA WP-3 aircraft conducted research flights as part of the second Texas Air Quality Study (TexAQS II). We examine measurements of NOx, SO2, and speciated hydrocarbons from the Houston Ship Channel, which contains a dense concentration of industrial petrochemical sources, and isolated petrochemical facilities. These measurements are used to derive source emission estimates, which are then compared to available emission inventories. We find that high hydrocarbon emissions are typical for the Houston Ship Channel and isolated petrochemical facilities. Ethene and propene are found to be major contributors to ozone formation. Ratios of C2H4 / NOx and C3H6 / NOx exceed emission inventory values by factors of 10 - 50. These findings are consistent with the first TexAQS study in 2000. We examine trends in C2H4 / NOx and C3H6 / NOx ratios between 2000 and 2006, and determine that day-to-day variability and within-plume variability exceeds any long-term reduction in ethene and propene emissions for the isolated petrochemical sources. We additionally examine downwind photochemical products formed by these alkenes.

Washenfelder, R. A.; Atlas, E. L.; Degouw, J.; Flocke, F. M.; Fried, A.; Frost, G. J.; Holloway, J.; Richter, D.; Ryerson, T. B.; Schauffler, S.; Trainer, M.; Walega, J.; Warneke, C.; Weibring, P.; Zheng, W.

2009-12-01

297

Monoterpene emissions from bark beetle infested Engelmann spruce trees  

NASA Astrophysics Data System (ADS)

Bark beetle infestation impacts the health of coniferous forests, which are an important source of volatile organic compounds (VOCs) to the atmosphere. The types and amounts of VOCs emitted from forests can influence secondary organic aerosol (SOA) formation and impact overall air quality. In this initial work, the impact of bark beetle infestation on SOA precursors from Engelmann spruce is assessed. The VOCs emitted from the trunk of infested and healthy spruce trees were sampled using both sorbent traps and evacuated canisters that were analyzed by gas chromatography/mass spectroscopy. The samples from the infested spruce tree suggest a nine-fold enhancement in the total VOC emissions. The dominant VOCs in the infested spruce trees were 3-carene, ?-pinene, and ?-pinene. The increase observed in VOCs sampled at the trunk of the infested spruce was consistent with increases observed at infested lodgepole pine trunks. However, the types and amounts of VOCs emitted from Engelmann spruce and lodgepole pine are different, which suggests that additional measures of VOC emissions are needed to characterize the impact of bark beetle infestation on VOC emissions and SOA precursors.

Amin, Hardik S.; Russo, Rachel S.; Sive, Barkley; Richard Hoebeke, E.; Dodson, Craig; McCubbin, Ian B.; Gannet Hallar, A.; Huff Hartz, Kara E.

2013-06-01

298

DIAL Measurements of Fugitive Emissions from Natural Gas Plants and the Comparison with Emission Factor Estimates  

Microsoft Academic Search

Natural gas processing is a major industry in Alberta, Canada, and a significant source of fugitive emissions of both methane and volatile organic hydrocarbon (VOCs). This project investigated fugitive emissions at natural gas processing plants in Alberta using two complementary optical measurement methods. At five gas plants, the fugitive emissions of methane and hydrocarbons ethane and larger (C2+ hydrocarbons) were

Allan K. Chambers; Mel Strosher; Tony Wootton; Jan Moncrieff; Philip McCready

299

User access to the MAP3S source emissions inventory  

SciTech Connect

An emissions inventory based on data obtained from the National Emissions Data System (NEDS), the Federal Power Commission (FPC), Environment Canada, and other agencies was compiled by the MAP3S Central Data Coordination at Brookhaven National Laboratory. Pertinent data was brought together, collated, and loaded into computerized data bases using SYSTEM 2000 as the data base management system. These data bases are available to interested users for interactive scanning or batch retrieval. The emissions inventory consists of two distinct sections: a point source inventory and an area source inventory. The point source inventory covers the continental US and Canada; information is kept at the individual source level. The area source inventory covers the continental US; information is kept on a county basis. Work is in progress to obtain a Canadian area source inventory based on census divisions.

Benkovitz, C M; Evans, V A

1981-03-01

300

METHOD FOR MEASURING CARBON FIBER EMISSIONS FROM STATIONARY SOURCES  

EPA Science Inventory

Carbon fibers are highly conductive, lightweight and of small dimensions. When released as emissions from production, manufacturing, processing and disposal sources they may become airborne and disperse over wide areas. If they settle onto electronic or electrical components they...

301

MEASUREMENT OF PM-10 EMISSIONS FROM STATIONARY SOURCES  

EPA Science Inventory

Measurements of PM-10 particulate matter emissions from stationary sources were performed using two sampling approaches currently under development. PM-10 particulate matter is defined as all particles nominally 10 micrometers aerodynamic diameter and smaller. Aerodynamic inertia...

302

40 CFR 63.1157 - Emission standards for existing sources.  

Code of Federal Regulations, 2013 CFR

...Steel Pickling-HCl Process Facilities and Hydrochloric Acid Regeneration Plants § 63.1157 Emission standards for existing sources...efficiency of less than 97 percent. (b) Hydrochloric acid regeneration plants. (1) No owner or operator of an existing...

2013-07-01

303

AIR POLLUTION: GROUND-BASED SENSING OF SOURCE EMISSIONS  

EPA Science Inventory

Some types of gaseous pollution sources, particularly extended area industrial complexes and those producing hot combustion products, cannot be monitored adequately with conventional point sampling methods. To aid in characterizing emissions from and in developing remote sensing ...

304

IRON AND STEEL PLANT OPEN SOURCE FUGITIVE EMISSION EVALUATION  

EPA Science Inventory

The report gives results of field tests aimed at increasing the reliability of equations used to predict emission factors for open fugitive emission sources at iron and steel plants. The accuracy of previously developed equations is limited by the restricted number of actual test...

305

Global Emission of Mercury from Anthropogenic Sources in 1995  

Microsoft Academic Search

An estimate of the global emission of mercury from anthropogenicsources in 1995 has been prepared. Major emphasis is placed onemissions from stationary combustion sources, non-ferrous metalproduction, pig iron and steel production, cement production andwaste disposal. About three quarters of the total emission,estimated to be about 1900 tonnes, was from combustion of fuels, particularly coal combustion in China, India, and South

E. G. Pacyna; J. M. Pacyna

2002-01-01

306

IRON AND STEEL PLANT OPEN SOURCE FUGITIVE EMISSION CONTROL EVALUATION  

EPA Science Inventory

The report gives results of measurements of the control efficiency of various techniques used to mitigate emissions from open dust sources in the iron and steel industry. Of estimated emissions of 88,800 tons/year suspended particulate in 1978 (based on a 10-plant survey), 70, 13...

307

Ammonia emissions from non-agricultural sources in the UK  

NASA Astrophysics Data System (ADS)

A detailed literature review has been undertaken of the magnitude of non-agricultural sources of ammonia (NH 3) in the United Kingdom. Key elements of the work included estimation of nitrogen (N) excreted by different sources (birds, animals, babies, human sweat), review of miscellaneous combustion sources, as well as identification of industrial sources and use of NH 3 as a solvent. Overall the total non-agricultural emission of NH 3 from the UK in 1996 is estimated here as 54 (27-106) kt NH 3-N yr -1, although this includes 11 (6-23) kt yr -1 from agriculture related sources (sewage sludge spreading, biomass burning and agro-industry). Compared with previous estimates for 1990, component source magnitudes have changed both because of revised average emissions per source unit (emission factors) and changes in the source activity between 1990 and 1996. Sources with larger average emission factors than before include horses, wild animals and sea bird colonies, industry, sugar beet processing, household products and non-agricultural fertilizer use, with the last three sources being included for the first time. Sources with smaller emission factors than before include: land spreading of sewage sludge, direct human emissions (sweat, breath, smoking, infants), pets (cats and dogs) and fertilizer manufacture. Between 1990 and 1996 source activities increased for sewage spreading (due to reduced dumping at sea) and transport (due to increased use of catalytic converters), but decreased for coal combustion. Combined with the current UK estimates of agricultural NH 3 emissions of 229 kt N yr -1 (1996), total UK NH 3 emissions are estimated at 283 kt N yr -1. Allowing for an import of reduced nitrogen (NH x) of 30 kt N yr -1 and deposition of 230 kt N yr -1, these figures imply an export of 83 kt NH 3-N yr -1. Although export is larger than previously estimated, due to the larger contribution of non-agricultural NH 3 emissions, it is still insufficient to balance the UK budget, for which around 150 kt NH 3-N are estimated to be exported. The shortfall in the budget is, nevertheless, well within the range of uncertainty of the total emissions.

Sutton, M. A.; Dragosits, U.; Tang, Y. S.; Fowler, D.

308

Source Location of Narrowband Radio Emission Detected at Saturn  

NASA Astrophysics Data System (ADS)

Since Cassini's arrival at Saturn in 2004, the Radio and Plasma Wave Science (RPWS) instrument has detected a series of narrowband radio emissions in Saturn's magnetosphere. It is believed that these narrowband emissions are first excited as electrostatic waves by electrons when the matching condition fuh = (n+1/2)fce is met, where fuh is the upper hybrid frequency and fce is the electron cyclotron frequency. These upper hybrid waves can mode convert to electromagnetic L-O waves in the presence of density gradients. We determined the polarization of the narrowband emissions and found it to be consistent with the prediction of linear mode conversion theory. To model the source region of narrowband emissions, we numerically calculated the locations where the matching condition is met in a meridian plane, using a scale height electron density model [Persoon et al., 2006] and a dipole magnetic field model. For the 5 kHz narrowband emission, the matching condition fuh = 3/2 fce is met at a radial distance of 5.6 RS and latitude of 32.6 degrees. For the 20 kHz emission, fuh = 3/2fce is met at 3.3 RS and 15.7 degrees latitude. In several selected events, Cassini went through the source region of narrowband emissions, as indicated by a strong electrostatic band preceding the radio emission. The coordinates of Cassini when the source of narrowband emissions are encountered closely match that predicted by the model. For these encounters with the narrowband emission source, we investigate the electron distribution functions obtained from the electron spectrometer (ELS) onboard Cassini, and perform an initial wave growth analysis for the electrostatic waves. For the electromagnetic radio component of narrowband emission, we employ a polarization reversal technique to determine the source locations. While the Cassini spacecraft is rotating, the apparent polarization of the radio emission measured by RPWS switches its rotation sense when the source goes through the antenna plane. By finding the intersection of the plane which contains the source with a ring of possible source locations predicted by our model, we can determine the longitudinal coordinate of the source.

Ye, S.; Gurnett, D. A.; Fischer, G.; Menietti, J. D.; Kurth, W. S.; Wang, Z.; Cecconi, B.; Zarka, P.; Rymer, A.; Young, D. T.; Coates, A. J.

2007-12-01

309

Convenient method of relative calibration of the neutron source emission rate between different source types  

Microsoft Academic Search

Neutron source emission rates are determined by absolute or relative measurement. The relative measurement is performed by comparing between a sample source and a calibrated reference source of the same type. In this calibration, the energy spectra of the sample and reference sources should be identical, since normally there exists energy dependence in the response of neutron detectors. We propose

H. Harano; T. Matsumoto; T. Shimoyama; Y. Sato; A. Uritani; Y. Hino; K. Kudo; T. Michikawa

2006-01-01

310

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

311

EMISSIONS ASSESSMENT OF CONVENTIONAL STATIONARY COMBUSTION SYSTEMS: VOLUME V: INDUSTRIAL COMBUSTION SOURCES  

EPA Science Inventory

The report characterizes air emissions from industrial external combustion sources and is the last of a series of five reports characterizing emissions from conventional combustion sources. The emissions characterization of industrial combustion sources was based on a critical ex...

312

Shallow vs. Deep Fluid Sources In Hydrothermal Systems: New Insights From VOC Composition In Fumarolic Discharges And Soil Gases Of Yellowstone National Park (USA)  

NASA Astrophysics Data System (ADS)

The origin of non-methane volatile organic compounds (VOCs) in hydrothermal fluids is related to two distinct mechanisms regulated by different thermodynamic conditions (e.g. Des Marais et al., 1981; Mango, 2000; Capaccioni and Mangani, 2001): i) thermogenic reactions, such as catalytic reforming and/or thermal cracking, which proceed within the main reservoir at medium-to-high temperature (150-350°C) and reduced conditions; ii) biodegradation processes, occurring at relatively shallow depth, where uprising fluids have <150°C and suffer oxidizing conditions. According to these considerations, the main aim of the present investigation is to discriminate the different fluid sources feeding the hydrothermal system on the basis of the C2-C15 organic compounds in fumarolic discharges and soil gases collected at the Yellowstone National Park (USA). A total of 64 and 66 different species were identified in the gas discharges and in the soil gas samples, respectively. The composition of the organic gas fraction in the fumarolic fluids is relatively homogeneous, being dominated by C2-C6 alkanes (81 %) and showing relatively high concentrations of alkenes (13 %), aromatics (3.7 %) and cyclics (1.4 %). Differently, the relative percentages of alkanes and alkenes in the soil gas, where VOC abundances are about two orders of magnitude less abundant than those in the gas discharges, are significantly lower (64 and 6.8 %, respectively) and cyclics are absent. On the other hand, oxygenated species (17.8 %), aromatics (5.6 %) and Cl-bearing compounds (4.5 %) results to be enriched with respect to those measured in the gas vents. Such compositional differences are likely to be due to the bacterial activity in the soil that causes the production of ketones, esters, alcohols, aldehydes and organic acids from the C-H species (hydrocarbons sensu strictu). Organic acids, mainly constituted by ossalic acid and traces of tartaric, malonic citric and succinic ones, were also determined in the fumarolic condensates. This seems to indicate that biodegradation likely occurs even within the hydrothermal systems, since the production of low molecular mass organic acids is to be related to bacterial activity (Arnetoli et al., 2008 and references therein). S-bearing compounds are strongly controlled by the fS values and this would explain the relatively high concentrations of these species in the H2S-rich fumarolic discharges. As far as it concerns the relatively high abundance of halogenated compounds in the soil gases, it can be suggested that the origin of these species is likely to be related to atmospheric contribution. Actually, formation of Cl- bearing species from reactions between VOCs and Cl-rich fluids, such as those of the deep hydrothermal reservoir, is still matter of debate. Therefore, we may speculate that these compounds, characterized by chemical inertness, are added to the hydrothermal fluids from meteoric water recharging the system. References: Arnetoli, M., Montegrossi, G., Buccianti, A., Gonnelli, C., 2008. J. Agricol. Food Chem., 56, 789- 795. Capaccioni, B., Mangani, F., 2001. Earth Planet. Sci. Lett., 188, 543-555. Des Marais, D.J., Donchin, J.H., Truesdell, A.H., Nehring, N.L., 1981. Nature, 292, 826-828. Mango, F.D., 2000. Geochim. Cosmochim. Acta, 64, 1265-1277.

Tassi, F.; Capecchiacci, F.; Montegrossi, G.; Caliro, S.; Chiodini, G.; Vaselli, O.

2008-12-01

313

VOCs monitoring system simulation and design  

NASA Astrophysics Data System (ADS)

The designed and simulated system will be used in the tanning industry, for Volatile Organic Compound (VOC) measurements. In this industry, about 90% of the solvent contained in the emulsions evaporates during its application, giving rise to VOC, which are at the same time hazardous atmospheric pollutants and one of the sources of ground level photochemical ozone formation. It results that a monitoring system is necessary in a leather finishing process, in order to detect hazardous VOC concentration and conducting process in order of VOC concentration diminishing. The paper presents the design of a VOC monitoring system, which includes sensors for VOCs and temperature, the conditioning circuitry for these sensors, the suction system of the gas in the hood, the data acquisition and the computing system and graphic interface. The used sensor in the detection system is a semiconductor sensor, produced by Figaro Engineering Inc., characterized by a short response time, high sensitivity at almost all VOC substances. The design of the conditioning circuitry and data acquisition is done in order to compensate the sensor response variation with temperature and to maintain the low response time of the sensor. The temperature compensation is obtained by using a thermistor circuitry, and the compensation is done within the software design. A Mitsubishi PLC is used to receive the output signals of the circuits including the sensor and of the thermistor, respectively. The acquisition and computing system is done using Mitsubishi ALPHA 2 controller and a graphical terminal, GOT 1000.

Caldararu, Florin; Vasile, Alexandru; Vatra, Cosmin

2010-09-01

314

Composite global emissions of reactive chlorine from anthropogenic and natural sources: Reactive Chlorine Emissions Inventory  

Microsoft Academic Search

Emission inventories for major reactive tropospheric Cl species (particulate Cl, HCl, ClNO2, CH3Cl, CHCl3, CH3CCl3, C2Cl4, C2HCl3, CH2Cl2, and CHClF2) were integrated across source types (terrestrial biogenic and oceanic emissions, sea-salt production and dechlorination, biomass burning, industrial emissions, fossil-fuel combustion, and incineration). Composite emissions were compared with known sinks to assess budget closure; relative contributions of natural and anthropogenic sources

William C. Keene; Archie McCulloch; Thomas E. Graedel; Jürgen M. Lobert; Michael L. Aucott; Sun Ling Gong; David B. Harper; Gary Kleiman; Pauline Midgley; Robert M. Moore; Christophe Seuzaret; William T. Sturges; Carmen M. Benkovitz; Valentin Koropalov; Leonard A. Barrie; Yi Fan Li

1999-01-01

315

WORKSHOP ON SOURCE EMISSION AND AMBIENT AIR MONITORING OF MERCURY  

EPA Science Inventory

AN EPA/ORD Workshop on Source Emission and Ambient Air Monitoring of Mercury was held on 9/13-14/99, Bloomington, Minnesota. The purpose of the workshop was to discuss the state-of-the-science in source and ambient air mercury monitoring as well as mercury monitoring research and...

316

Source Emissions in Multipollutant Air Quality Management  

EPA Science Inventory

Human activities and natural processes that emit pollutants into the ambient atmosphere are the underlying cause of all air quality problems. In a technical sense, we refer to these activities and processes as pollutant sources. Although air quality management is usually concerne...

317

CHARACTERIZATION OF NITROUS OXIDE EMISSION SOURCES  

EPA Science Inventory

The report presents a global inventory of nitrous oxide (N2O) based on reevaluation of previous estimates and additions of previously uninventoried source categories. (NOTE: N2O is both a greenhouse gas and a precursor of nitric oxide (NO) which destroys stratospheric ozone.) The...

318

Neptune's non-thermal radio emissions - Phenomenology and source locations  

NASA Astrophysics Data System (ADS)

During the inbound and the outbound leg of Voyager 2's encounter with Neptune, the Planetary Radio Astronomy (PRA) experiment aboard the spacecraft detected short radio bursts at frequencies within the range of about 500-1300 kHz, and broad-banded smoothly varying emission patterns within the frequency range from about 40-800 kHz. Both emissions can be described in terms of a period of 16.1 hours determining Neptune's rotation period. Furthermore, just near closest approach, a narrow-banded smoothly varying radio component was observed occurring between 600 and 800 kHz. After giving a brief overview about some general characteristics of Neptune's nonthermal radio emission, the source locations of Neptune's emission components are determined, using an offset tilted dipole model for Neptune's magnetic field. Assuming that the emission originates near the electron gyrofrequency a geometrical beaming model is developed in order to fit the observed emission episodes.

Rabl, Gerald K. F.; Ladreiter, H.-P.; Rucker, Helmut O.; Kaiser, Michael L.

319

DISCOVERY OF LIGHT EMISSION FROM XRF SOURCES  

Microsoft Academic Search

Fluorescent light has been detected recently along with Rb, Ba, Tb, Cu, Mo, or Ag X-rays during ?- excitation of Rubidium sulphate, Barium oxide, or Terbium peroxide salt, and Cu, Mo, or Ag metal notably at room temperature (Variable Energy X-ray source, AMC 2084, UK). This insight led to the discovery of a new atomic phenomenon that occurs in X-ray

M. A. Padmanabha Rao

320

Methane emissions from grazing cattle using point-source dispersion.  

PubMed

The ability to accurately measure greenhouse gas (GHG) emissions is essential to gauge our ability to reduce these emissions. Enteric methane from ruminants is an important but often difficult source to quantify since it depends on the amount and type of feed intake. Unfortunately, many of the available measurement techniques for estimating enteric methane emissions can impose a change in feed intake. Our study evaluates a nonintrusive technique that uses a novel approach (point-source dispersion with multiple open-path concentrations) to calculate enteric methane emissions from grazing cattle, reported as the major source of GHG in many countries, particularly Australia. A scanner with a mounted open-path laser was used to measure methane concentration across five paths above a paddock containing 18 grazing cattle over 16 d. These data were used along with wind statistics in a dispersion model (WindTrax) to estimate an average herd methane emission rate over 10-mm intervals. Enteric methane emissions from the herd grazing a combination of Rhodes grass (Chlotis gayana Kunth) and Leucaena [Leucaena leucocephala (Lam.)] averaged (+/- SD) 141 (+/- 147) g animal(-1) d(-1). In a release-recovery experiment, the technique accounted for 77% of the released methane at a single point. Our study shows the technique generates more reliable methane emissions during daytime (unstable stratification). PMID:21488489

McGinn, S M; Turner, D; Tomkins, N; Charmley, E; Bishop-Hurley, G; Chen, D

321

Cryogenic condensation puts a chill on VOCs  

SciTech Connect

Any industry that uses or handles solvents as part of the manufacturing process--production, storage or recycling--will at some point release volatile organic compounds (VOCs) into the atmosphere. It is difficult for any company to select an abatement technique that is both affordable and will meet the requirements of the specific VOC emission regulations. The selection process can be complicated because such a wide range of VOC control technologies is available. While many of these VOC control technologies satisfy regulatory requirements, the challenge is to find a technology that is not only efficient but also cost effective. One such technique uses low-temperature condensation for abatement and recovery of VOCs emitted during the manufacturing process. The low-temperature refrigeration for the system is provided by the cooling value in liquid nitrogen. Most chemical processing industries use significant quantities of liquid nitrogen in applications such as inerting, blanketing and purging; it can be reused onsite, therefore, and no additional nitrogen need be purchased. As a result, VOC control is achieved with low operating costs.

Zeiss, R.F.; Ibbetson, C.

1997-09-01

322

40 CFR 63.1505 - Emission standards for affected sources and emission units.  

Code of Federal Regulations, 2010 CFR

...Hazardous Air Pollutants for Secondary Aluminum Production Emission Standards and Operating...standards for each type of source. (b) Aluminum scrap shredder. On and after the compliance...1501, the owner or operator of an aluminum scrap shredder at a secondary...

2012-07-01

323

Emittance of a field emission electron source  

NASA Astrophysics Data System (ADS)

An analytical formula of the emittance of a field emitter is given. In contrast to thermal and photoemission, such a formula contains complexity due to the multidimensional nature of the source. A formulation of emittance is given for one- and three-dimensional (3D) field emitters. The 3D formulation makes use of the point charge model of a unit cell emitter coupled with a trajectory analysis to follow electrons to an evaluation plane where emittance is determined. The single tip theory is extended to an array and the resulting theory predicts the emittance of a Spindt-type square array of emitters 0.2 cm on a side producing 2000 A/cm2 is 23 mm mrad. Theory compares favorably with experimental measurements in the literature from ungated and gated sources. The impacts of several complications are estimated: the effects of a gate for modulating the emitter; the influence of space charge within the unit cell on the beam; and constraints imposed by modulation frequency, emitter dimensions, and rise/fall time requirements for turning a beam on and off, as determined by the array's RLC characterization.

Jensen, K. L.; O'Shea, P. G.; Feldman, D. W.; Shaw, J. L.

2010-01-01

324

Distribution of airborne particles from multi-emission source.  

PubMed

The purpose of this work was to study the distribution of airborne particles in the surroundings of an iron and steel factory in southern Finland. Several sources of particulate emissions are lying side by side, causing heavy dust loading to the environment. This complicated multi-pollutant situation was studied mainly by SEM/EDX methodology. Particles accumulated on Scots pine bark were identified and quantitatively measured according to their element content, size and shape. As a result, distribution maps of particulate elements were drawn and the amount of different particle types along the study lines was plotted. Particulate emissions from the industrial or energy production processes were not the main dust source. Most emissions were produced from the clinker crusher. Numerous stockpiles of the industrial wastes and raw materials also gave rise to particulate emissions as a result of wind erosion. It was concluded that SEM/EDX methodology is a useful tool for studying the distribution of particulate pollutants. PMID:12807259

Kemppainen, Sari; Tervahattu, Heikki; Kikuchi, Ryunosuke

2003-06-01

325

FIGARO : measuring neutron emission spectra with a white neutron source /.  

SciTech Connect

Neutron emission spectra from reactions induced by fast neutrons are of importance in basic physics and applications. Very few data are available in the literature over a wide range of incident neutron energies such as produced with a white neutron source. The FIGARO facility at the WNR/LANSCE neutron source has been established to measure such neutron emission over a range of incident neutron energies from 1 to over 100 MeV. Using the time-of-flight technique twice (once to determine the incident neutron energy and again to determine the outgoing neutron energy), we are measuring neutron emission spectra for several reactions such as (n,n') and (n,f). Neutron emission from inelastic scattering gives information on the level density of excited states of the target nucleus. Our first measurements are on structural materials such as iron.

Haight, Robert C.; O'Donnell, J. M.; Zanini, L.; Devlin, M.; Rochman, D. (Dimitri)

2002-01-01

326

X-ray emission from GPS and CSS sources  

NASA Astrophysics Data System (ADS)

Many X-ray observations of GigaHertz Peaked Spectrum and Compact Steep Spectrum sources have been made with Chandra X-ray Observatory and XMM-Newton Observatory over the last few years. The X-ray spectra contribute the important information to the total energy distribution of the compact radio sources. In addition the spatial resolution of Chandra allows for studies of the X-ray morphology of these sources on arcsec scales and provide a direct view of their environments. This paper gives a review of the current status of the X-ray observations and their contribution to our understanding of the nature of these compact radio sources. It also describes primary physical processes that lead to the observed X-ray emission and summarize X-ray emission properties expected from interactions between an expanding radio source and the intergalactic environment.

Siemiginowska, A.

2009-02-01

327

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 ...

328

Reduction of VOCs in flue gas from coal combustion by electron beam treatment  

Microsoft Academic Search

Coal combustion is one of the biggest sources of VOCs, which are emitted with various concentrations, polynuclear aromatic hydrocarbons (PAH) are known as the most dangerous, and among them, e.g. benzo(a)pyrene C20H12, benzo(g,h,I)perylene C22H12 or dibenzo(a,h)anthracene C22H14 are the most toxic according to EPA. Recent years have brought new regulations concerning PAH emission, and European countries have signed an international

A. G Chmielewski; A. Ostapczuk; Z. Zimek; J. Licki; K. Kubica

2002-01-01

329

Applications of Open-Path Fourier Transform Infrared for Identification of Volatile Organic Compound Pollution Sources and Characterization of Source Emission Behaviors  

Microsoft Academic Search

An open-path Fourier transform infrared spectroscopy (OP-FTIR) system was set up for 3-day continuous line-averaged volatile organic compound (VOC) monitoring in a paint manufacturing plant. Seven VOCs (toluene, m-xylene, p-xylene, styrene, methanol, acetone, and 2-butanone) were identified in the ambient environment. Daytime-only batch operation mode was well explained by the time-series concentration plots. Major sources of methanol, m-xylene, acetone, and

Chitsan Lin; Naiwei Liou; Endy Sun; Edwin Corporan; Matthew DeWitt; Chester Spicer; Michael Holdren; Kenneth Cowen; Alex Laskin; David Harris; Richard Shores; Robert Kagann; Ram Hashmonay; Francesca Sprovieri; Nicola Pirrone; Larry Jacobson; Brian Hetchler; David Schmidt; Richard Nicolai; Albert Heber; Ji-Qin Ni; Steven Hoff; Jacek Koziel; Yuanhui Zhang; David Beasley; David Parker; Roxolana Kashuba; Peter Scheff; Aniket Sawant; David Cocker; J. Miller; Tony Taliaferro; David Diaz-Sanchez; William Linn; Kenneth Clark; Henry Gong; Gustavo Olivares; Johan Strom; Christer Johansson; Lars Gidhagen

2008-01-01

330

VOC composition of current motor vehicle fuels and vapors, and collinearity analyses for receptor modeling.  

PubMed

The formulation of motor vehicle fuels can alter the magnitude and composition of evaporative and exhaust emissions occurring throughout the fuel cycle. Information regarding the volatile organic compound (VOC) composition of motor fuels other than gasoline is scarce, especially for bioethanol and biodiesel blends. This study examines the liquid and vapor (headspace) composition of four contemporary and commercially available fuels: gasoline (<10% ethanol), E85 (85% ethanol and 15% gasoline), ultra-low sulfur diesel (ULSD), and B20 (20% soy-biodiesel and 80% ULSD). The composition of gasoline and E85 in both neat fuel and headspace vapor was dominated by aromatics and n-heptane. Despite its low gasoline content, E85 vapor contained higher concentrations of several VOCs than those in gasoline vapor, likely due to adjustments in its formulation. Temperature changes produced greater changes in the partial pressures of 17 VOCs in E85 than in gasoline, and large shifts in the VOC composition. B20 and ULSD were dominated by C(9) to C(16)n-alkanes and low levels of the aromatics, and the two fuels had similar headspace vapor composition and concentrations. While the headspace composition predicted using vapor-liquid equilibrium theory was closely correlated to measurements, E85 vapor concentrations were underpredicted. Based on variance decomposition analyses, gasoline and diesel fuels and their vapors VOC were distinct, but B20 and ULSD fuels and vapors were highly collinear. These results can be used to estimate fuel related emissions and exposures, particularly in receptor models that apportion emission sources, and the collinearity analysis suggests that gasoline- and diesel-related emissions can be distinguished. PMID:22154341

Chin, Jo-Yu; Batterman, Stuart A

2011-12-10

331

CO2 EMISSIONS FROM BIOENERGY AND OTHER BIOGENIC SOURCES IN STATIONARY SOURCES  

EPA Science Inventory

On January 12, 2011, EPA announced a series of steps to address the treatment of biogenic CO2 emissions from stationary sources, including a detailed study of the scientific and technical issues associated with accounting for biogenic carbon dioxide emissions from stationary sour...

332

EMISSIONS ASSESSMENT OF CONVENTIONAL STATIONARY SYSTEMS: VOLUME III. EXTERNAL COMBUSTION SOURCES FOR ELECTRICITY GENERATION  

EPA Science Inventory

The report characterizes multimedia emissions from external combustion sources for electricity generation. Study results indicate that external combustion sources for electricity generation contribute significantly to the nationwide emissions burden. Flue gas emissions of NOx, SO...

333

40 CFR 63.5984 - What emission limits must I meet for tire production affected sources?  

Code of Federal Regulations, 2012 CFR

...FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Emission Limits for Tire Production Affected Sources § 63.5984 What emission limits must I...

2012-07-01

334

63 FR 50280 - National Emission Standards for Hazardous Air Pollutants for Source Categories: Pharmaceuticals...  

Federal Register 2010, 2011, 2012, 2013

...National Emission Standards for Hazardous Air Pollutants for Source Categories: Pharmaceuticals...National Emission Standards for Hazardous Air Pollutants for Source Categories: Pharmaceuticals...national emission standards for hazardous air pollutants (NESHAP) to reduce air...

1998-09-21

335

62 FR 15228 - National Emission Standards for Hazardous Air Pollutants for Source Categories; Wool Fiberglass...  

Federal Register 2010, 2011, 2012, 2013

...National Emission Standards for Hazardous Air Pollutants for Source Categories; Wool...National Emission Standards for Hazardous Air Pollutants for Source Categories; Wool...national emission standards for hazardous air pollutants (NESHAP) for new and...

1997-03-31

336

60 FR 45948 - National Emission Standards for Hazardous Air Pollutants for Source Categories: Aerospace...  

Federal Register 2010, 2011, 2012, 2013

...National Emission Standards for Hazardous Air Pollutants for Source Categories; Final...National Emission Standards for Hazardous Air Pollutants for Source Categories: Aerospace...National emission standards for hazardous air pollutants (NESHAP) for aerospace...

1995-09-01

337

64 FR 31898 - National Emission Standards for Hazardous Air Pollutants for Source Categories; Portland Cement...  

Federal Register 2010, 2011, 2012, 2013

...National Emission Standards for Hazardous Air Pollutants for Source Categories; Portland...National Emission Standards for Hazardous Air Pollutants for Source Categories; Portland...national emission standards for hazardous air pollutants (NESHAP) for new and...

1999-06-14

338

Air Emissions Guide for Air Force Mobile Sources: Methods for Estimating Emissions of Air Pollutants for Mobile Sources at U.S. Air Force Installations.  

National Technical Information Service (NTIS)

Provides a uniform approach to calculating air pollutant emissions for the most common mobile sources found at Air Force installations. This guide is the Air Force's single authoritative resource for mobile source emission estimating algorithms and emissi...

2013-01-01

339

FEASIBILITY OF DEVELOPING SOURCE SAMPLING METHODS FOR ASBESTOS EMISSIONS  

EPA Science Inventory

The objective of this program was to determine the feasibility of developing methods for sampling asbestos in the emissions of major asbestos sources: (1) ore production and taconite production, (2) asbestos-cement production, (3) asbestos felt and paper production, and (4) the p...

340

Glow discharge lamp: A light source for optical emission spectroscopy  

Microsoft Academic Search

A glow discharge lamp based on a modified version of the Grimm design has been fabricated. Its utility as a radiation source for optical emission spectrography by standardizing a method for the analysis of low alloy steels using a set of certified standards from DMRL, Hyderabad, has been demonstrated. A model has been proposed where the sputtering rates of different

K. S. Vishwanathan; V. Srinivasan; S. Nalini; T. R. Mahalingam

1990-01-01

341

PCB EMISSIONS FROM STATIONARY SOURCES: A THEORETICAL STUDY  

EPA Science Inventory

The report gives results of a theoretical assessment of polychlorinated biphenyl (PCB) formation and destruction in conventional fossil fuel fired sources. Results suggest a small but finite possibility that PCB isomers may be found in their emissions. The study was the result of...

342

MEASURING INORGANIC AND ALKYL LEAD EMISSIONS FROM STATIONARY SOURCES  

EPA Science Inventory

Described are the results from studies done to provide test methods for state and local air pollution control agencies to measure accurately the lead emissions from stationary source stacks as required in the National Ambient Air Quality Standard for Lead. Inorganic lead is colle...

343

Area Source Emission Inventory for Dougherty County, Georgia. Volume I.  

National Technical Information Service (NTIS)

This project was undertaken to prepare an inventory of area sources of particulate matter, SOx, CO, HC, and NOx emissions in the Albany area for use in analysis and modeling of air quality in this designated Air Quality Maintenance Area for the period 197...

L. J. Ungers

1975-01-01

344

Area Source Emission Inventory for Dougherty County, Georgia. Volume II.  

National Technical Information Service (NTIS)

Volume 2 contains tables of the data obtained in an inventory of area sources of particulate matter, SOx, CO, HC, and NOx emissions in the Albany area for use in analysis and modeling of air quality in this designated Air Quality Maintenance Area for the ...

L. J. Ungers

1975-01-01

345

SENSITIVITY OF RADM TO POINT SOURCE EMISSIONS PROCESSING  

EPA Science Inventory

The Regional Acid Deposition Model (RADM) and associated Engineering Model have been developed to study episodic source-receptor relationships on a regional scale. he RADM includes transport, chemical transformation, and deposition processes as well as input of emissions into the...

346

COMPARATIVE STUDY OF OPEN SOURCE PARTICULATE EMISSION MEASURING TECHNIQUES  

EPA Science Inventory

The paper gives results of a comparative study of variations in measuring and analytical techniques used to assess sources upon which emission factor data bases are built (in an effort to quantify these technique-dependent parameters). The study included a simultaneous, side-by-s...

347

Bronnen van Diffuse Bodembelasting (Sources of Diffuse Emissions to Soil).  

National Technical Information Service (NTIS)

The aim of this study was to support the policy on preventive soil protection with information on the diffuse (non-local) emissions to soil and the influence on future soil quality. This study is related to inventories on (potential) sources of local soil...

J. P. A. Lijzen A. Ekelenkamp

1995-01-01

348

Literature Review of Greenhouse Gas Emissions from Biogenic Sources.  

National Technical Information Service (NTIS)

The report gives results of a literature review of estimates of biogenic emissions of five greenhouse gases: CO2, CH4, N2O, and NOx. Review results include data and information from about 170 sources published over the past 10 years. The report's two sect...

D. Campbell M. Stockton S. Buchanan J. McLean R. Pandullo

1990-01-01

349

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

350

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

351

EPA's mobile monitoring of source emissions and near-source impact  

EPA Science Inventory

Real-time ambient monitoring onboard a moving vehicle is a unique data collection approach applied to characterize large-area sources, such as major roadways, and detect fugitive emissions from distributed sources, such as leaking oil wells. EPA's Office of Research and Developme...

352

Characterization of nitrous oxide emission sources. Final report  

SciTech Connect

Nitrous oxide (N2O) is both a greenhouse gas and a precursor of nitric oxide (NO), which destroys stratospheric ozone. This study presents a global N2O inventory based on re-evaluation of previous estimates and additions of previously uninventoried source categories. The best estimate of anthropogenic N2O is 5.7 Tg/yr, which is still much lower than natural source emissions. Much uncertainty remains about estimates for many source categories. Inadequate data are available for some categories; others are limited by a lack of reliable functional models of factors affecting emmissions rates.

Peer, R.L.; Epner, E.P.; Billings, R.S.

1995-07-01

353

75 FR 32682 - National Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial...  

Federal Register 2010, 2011, 2012, 2013

...Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial...Emission Standards for Hazardous Air Pollutants for Area Sources: Industrial...Standards of Performance for New Stationary Sources and...

2010-06-09

354

75 FR 42676 - National Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial...  

Federal Register 2010, 2011, 2012, 2013

...Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial...Emission Standards for Hazardous Air Pollutants for Area Sources: Industrial...Standards of Performance for New Stationary Sources and...

2010-07-22

355

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

NASA Astrophysics Data System (ADS)

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

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

2012-09-01

356

Source characteristics of Jovian narrow-band kilometric radio emissions  

NASA Astrophysics Data System (ADS)

New observations of Jovian narrow-band kilometric (nKOM) radio emissions were made by the Unified Radio and Plasma Wave (URAP) experiment on the Ulysses spacecraft during the Ulysses-Jupiter encounter in early February 1992. These observations have demonstrated the unique capability of the URAP instrument for determining both the direction and polarization of nKOM radio sources. An important result is the discovery that nKOM radio emission originates from a number of distinct sources located at different Jovian longitudes and at the inner and outermost regions of the Io plasma torus. These sources have been tracked for several Jovian rotations, yielding their corotational lags, their spatial and temporal evolution, and their radiation characteristics at both low latitudes far from Jupiter and at high latitudes near the planet. Both right-hand and left-hand circularly polarized nKOM sources were observed. The polarizations observed for sources in the outermost regions of the torus seem to favor extraordinary mode emission.

Reiner, M. J.; Fainberg, J.; Stone, R. G.; Kaiser, M. L.; Desch, M. D.; Manning, R.; Zarka, P.; Pedersen, B.-M.

1993-07-01

357

ON-ROAD VEHICLE EMISSIONS: USA STUDIES  

EPA Science Inventory

Several recent events in mobile sources emissions measurements have caused a major reassessment in the amounts of volatile organic compounds (VOC) and carbon monoxide (CO) in the ambient air attributed to mobile sources. hese include the comparison of real world in-use vehicle em...

358

METHOD FOR SEPARATING VOLATILE ORGANIC CARBON FROM 0.1 M3 OF AIR TO IDENTIFY SOURCES OF OZONE PRECURSORS VIA ISOTOPE (14C) MEASUREMENTS  

EPA Science Inventory

Atmospheric non-methane volatile organic compounds (VOCS) are known to play an important role in urban ozone formation during the summer. o respond to the need for a direct measure of VOC source contributions from biogenic (14C/12C=10-12) and fossil fuel (14C/12C=O) emissions, a ...

359

Estimating DNAPL composition and VOC dilution from extraction well data  

Microsoft Academic Search

Field data from a large-scale ground-water extraction system at the Savannah River Site in South Carolina indicate that considerable dilution of volatile organic compounds (VOCs) occurs at extraction wells when compared with the effective solubilities of the VOC components (TCE and PCE) in the dense, nonaqueous phase liquid (DNAPL) source zone. This dilution is believed to be due to the

R. E. Jackson; P. E. Mariner

1995-01-01

360

VOCs Speciation From Steam Boiler Stacks of Industries Located in Naucalpan  

NASA Astrophysics Data System (ADS)

Results of VOCs speciation from industrial steam boiler stacks located in Naucalpan are presented and discussed. This municipality is located north of the Metropolitan Zone of the Valley of Mexico (MZVM). Speciation of VOCs is important to generate information about sources of pollution, to update emission inventories, to study the dynamics of pollutants in the atmosphere, and to estimate possible risks of population exposure. This information is valuable for decision making on air pollution control strategies. Samples from 35 steam boilers form industries burning Diesel, LPG, or CNG were taken using the US-EPA Method 18. Selected samples from the use of different fuels were analyzed using gas chromatography and flame ionization detection (GC-FID) according to US-EPA protocol TO-14. The VOCs analyzed included alkanes of 9 carbons or less, alkenes of 7 carbons or less and aromatics (families of benzene). The results show consistency on the VOCs detected on Diesel samples. The main compounds found were 1- Butene+iButylene, m/p-Xylene, Ethane, Propene, Propane, Acetylene, 2Me-1Butene, and Toluene. The average concentrations of these compounds were in the range of 130 to 385 ppbC. The results of LPG samples did not show a definite pattern of VOCs, although light components predominate and, in some samples, Toluene and Xylene. These last components were not expected for industries reporting the use of LPG, perhaps due to the use of a combination of fuels and mistakes in the reports of fuel used at the time of sampling. The analysis of CNG samples show predominance of light VOCs, in the range of 90 to 300 ppbC. As in the case of LPG, some aromatics showed high concentrations in some samples analyzed perhaps due to the use of different fuels in the boiler. The results of this study are the first results of VOCs speciation obtained form exhaust gases from stacks of Mexican industries. The data reported are valuable to analyze emission inventories of VOCs and to better understand the dynamics of pollutants in the MZVM.

Mejia, G. M.; Tejeda, D. D.; Bremauntz, M. P.; Valdez, A.; Montufar, P. C.; Martinez, M. A.; Sierra, M. J.; Gonzalez, C. A.

2007-05-01

361

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

Microsoft Academic Search

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

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

2010-01-01

362

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

PubMed

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

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

2001-05-01

363

Quantifying natural source mercury emissions from the Ivanhoe Mining District, north-central Nevada, USA  

Microsoft Academic Search

In order to assess the importance of mercury emissions from naturally enriched sources relative to anthropogenic point sources, data must be collected that characterizes mercury emissions from representative areas and quantifies the influence of various environmental parameters that control emissions. With this information, we will be able to scale up natural source emissions to regional areas. In this study in

Mark A. Engle; Mae Sexauer Gustin; Hong Zhang

2001-01-01

364

Shallow vs. Deep Fluid Sources In Hydrothermal Systems: New Insights From VOC Composition In Fumarolic Discharges And Soil Gases Of Yellowstone National Park (USA)  

Microsoft Academic Search

The origin of non-methane volatile organic compounds (VOCs) in hydrothermal fluids is related to two distinct mechanisms regulated by different thermodynamic conditions (e.g. Des Marais et al., 1981; Mango, 2000; Capaccioni and Mangani, 2001): i) thermogenic reactions, such as catalytic reforming and\\/or thermal cracking, which proceed within the main reservoir at medium-to-high temperature (150-350°C) and reduced conditions; ii) biodegradation processes,

F. Tassi; F. Capecchiacci; G. Montegrossi; S. Caliro; G. Chiodini; O. Vaselli

2008-01-01

365

[VOCs tax policy on China's economy development].  

PubMed

In this paper, environmental tax was designed to control volatile organic compounds (VOCs) emissions. Computable general equilibrium (CGE) model was used to explore the impacts of environmental tax (in forms of indirect tax) on the macro-economy development at both national and sector levels. Different levels of tax were simulated to find out the proper tax rate. It is found out that imposing environmental tax on high emission sectors can cause the emission decreased immediately and can lead to negative impacts on macro-economy indicators, such as GDP (gross domestic products), total investment, total product and the whole consumption etc. However, only the government income increased. In addition, the higher the tax rate is, the more pollutants can be reduced and the worse economic effects can be caused. Consequently, it is suggested that, the main controlling policies of VOCs abatement should be mandatory orders, and low environmental tax can be implemented as a supplementary. PMID:22468510

Liu, Chang-Xin; Wang, Yu-Fei; Wang, Hai-Lin; Hao, Zheng-Ping; Wang, Zheng

2011-12-01

366

The infrared emission bands. III. Southern IRAS sources.  

PubMed

We present airborne 5-8 micrometers spectra of southern IRAS sources which reveal strong polycyclic aromatic hydrocarbon (PAH) emission features. The good correlation between the bands, in particular the dominant 6.2 and "7.7" micrometers features, strongly imply a common carrier, reinforcing the PAH hypothesis. However, small but detectable spectral variations exist. Planetaries have a distinctly different ratio of I(6.2)/I(7.7) than other nebulae, accompanied by a redward shift in the actual wavelength of the "7.7" micrometers peak. Further, we have detected a new feature, previously predicted from laboratory spectra of PAH molecules, at 5.2 micrometers in many of these sources. Spectra of two rare [WC 10] planetary nebular nuclei indicate a very prominent plateau of emission, linking the 6.2 and 7.7 micrometers bands. Several of our sources show definite evidence for emission structure between 14 and 23 micrometers in their IRAS Low-Resolution Spectral Atlas spectra: we attribute this structure to PAH bands. too. We have defined the "generic" spectrum of emission bands relating the mean intensities of each band to that of the strongest, near 7.7 micrometers. We have added three more planetary or protoplanetary nebulae to our correlation between 7.7 micrometers band intensity and nebular gas phase C/O ratio, namely NGC 6302, HR 4049, and the highly carbon-rich [WC 10] nucleus, CPD--56 degrees 8032. For the latter we have determined a ratio for C/O of approximately 4.8 from IUE observations. The good correlation between the intensity ratio of the "7.7" micrometers feature relative to the far-infrared dust continuum and nebular C/O also supports a carbonaceous carrier for these emission features. PMID:11542167

Cohen, M; Tielens, A G; Bregman, J; Witteborn, F C; Rank, D M; Allamandola, L J; Wooden, D H; de Muizon, M

1989-06-01

367

Mercury emissions from selected stationary combustion sources in Korea  

Microsoft Academic Search

Mercury emissions from various stationary combustion sources such as coal-fired power plants, oil-fired power plants, industrial utility oil boilers, iron manufacturing plants, and industrial waste incinerators, were measured. The US EPA (Environmental protection agency) method 101A and the Ontario hydro method were used to sample the mercury containing combustion flue gases, at the inlet of the air pollution control devices

Sung Jun Lee; Yong-Chil Seo; Jongsoo Jurng; Ji-Hyung Hong; Jin-Won Park; Jung Eun Hyun; Tai Gyu Lee

2004-01-01

368

Regulation of air-pollutant emissions from mobile sources. [Monograph  

Microsoft Academic Search

This paper reviews the history and the costs and benefits of the federal mobile air-pollutant-sources program. The author argues that the program has substantially reduced emissions from motor vehicles, but at a high cost to vehicle users. Current and prospective vehicle standards do not pass a cost\\/benefit test. He finds the overall program too ambitious and part of it poorly

1981-01-01

369

Carbonyl emissions from vehicular exhausts sources in Hong Kong.  

PubMed

Vehicular emission (VE) is one of the important anthropogenic sources for airborne carbonyls in urban area. Six types of VE-dominated samples were collected at representative locations in Hong Kong where polluted by a particular fueled type of vehicles, including (i) a gas refilling taxis station (liquefied petroleum gas [LPG] emission); (ii) a light-duty passenger car park (gasoline emission); (iii) a minibus station (diesel emission); (iv) a single-deck-bus depot (diesel emission); (v) a double-deck-bus depot (diesel emission); and (vi) a whole-food market entrance for light- and heavy-duty vehicles (diesel emission). A total of 15 carbonyls in the samples were quantified. Formaldehyde was the most abundant carbonyl among the VE-dominated samples, and its contribution to the total quantified amount on a molar basis ranged from 54.8% to 60.8%. Acetaldehyde and acetone were the next two abundant carbonyls. The carbonyls were quantified at three roadside locations in Hong Kong. The highest concentrations of formaldehyde and acetaldehyde, 22.7 +/- 8.4 and 6.0 +/- 2.8 microg/m3, respectively, were determined in the samples collected at a main transportation gate for goods between Hong Kong and Mainland China. The total quantified carbonyl concentration, 37.9 +/- 9.3 microg/m3, was the highest at an entrance of a cross-harbor tunnel in downtown area. The theoretical carbonyls compositions of the three roadside locations were estimated according to the VE-dominated sample profiles and the statistics on vehicle numbers and types during the sampling period. The measured compositions of formaldehyde were much higher than the theoretical compositions in summer, demonstrating that photochemical reactions significantly contributed to the formaldehyde production in the roadsides. PMID:22442938

Ho, Steven Sai Hang; Ho, Kin Fai; Lee, Shun Cheng; Cheng, Yan; Yu, Jian Zhen; Lam, Ka Man; Feng, Natale Sin Yau; Huang, Yu

2012-02-01

370

Recover VOCs via adsorption on activated carbon  

SciTech Connect

One of the most effective methods of controlling emissions of volatile organic compounds (VOCs) is also one of the most economical--adsorption, usually using activated carbon as the adsorbent. This process is cost-effective because it is typically able to recover many VOCs for reuse. A particularly common application of carbon adsorption for VOC control is solvent recovery. In general, solvent recovery via carbon adsorption is a logical consideration for any industrial process exhausting sizable quantities of valuable solvent (subject, of course, to the solvent's suitability for adsorption by activated carbon, as discussed later). The most commonly recovered solvents include toluene; heptane; hexane; carbon tetrachloride; acetone; ethyl acetate; methyl ethyl ketone(MEK); naphthalene; and methylene chloride. Many other solvents are also suitable for recovery by carbon adsorption. A recent CEP article discussed the basics of carbon adsorption and application of the technology to water and wastewater treatment. This article takes an in-depth look at the use of activated carbon adsorption of the control of airborne VOC emissions and solvent recovery. It outlines how to decide if carbon adsorption is suitable for an application and then explains how to implement the technology.

Ruhl, M.J. (Dedert Corp., Olympia Falls, IL (United States). Solvent Recovery Div.)

1993-07-01

371

Diagnosis of air quality through observation and modeling of volatile organic compounds (VOCs) as pollution tracers  

NASA Astrophysics Data System (ADS)

This study used selected ambient volatile organic compounds (VOCs) as pollution tracers to study the effects of meteorology on air quality. A remote coastal site was chosen as a receptor to monitor pollutants transported upwind from urban traffic and industrial sources. Large concentration variability in VOC concentrations was observed at the coastal site due to rapid changes in meteorology, which caused periodic land-sea exchange of air masses. To assure the quality of the on-line measurements, uniform concentrations of chlorofluorocarbon-113 (CFC-113) were exploited as an internal check of the instrument’s stability and the resulting data quality.A VOC speciated air quality model was employed to simulate both temporal and spatial distributions of VOC plumes. The model successfully captured the general features of the variations of toluene as a pollution tracer, which suggests that emissions and meteorology were reasonably well simulated in the model. Through validation by observation, the model can display both the temporal and spatial distribution of air pollutants in a dynamic manner. Thus, a more insightful understanding of how local air quality is affected by meteorology can be obtained.

Liu, Wen-Tzu; Hsieh, Hsin-Cheng; Chen, Sheng-Po; Chang, Julius S.; Lin, Neng-Huei; Chang, Chih-Chung; Wang, Jia-Lin

2012-08-01

372

Volatile organic compounds in suburban Ankara atmosphere, Turkey: Sources and variability  

NASA Astrophysics Data System (ADS)

In this study, concentrations of approximately 30 VOCs were measured, between January and June 2008 at a university campus in Ankara. Concentrations of measured VOCs are lower than corresponding concentrations reported for other cities in literature. Average concentrations of the measured VOCs ranged from 0.04 to 7.89 ?g m- 3. Benzene (2.18 ?g m- 3), toluene (7.89 ?g m- 3), ethylbenzene (0.85 ?g m- 3) and xylenes (2.62 ?g m- 3) (BTEX) were found as a major organics in suburban Ankara atmosphere. The measured VOCs also show well defined diurnal and weekday-weekend cycles. Toluene-to-benzene ratio (T/B) suggested that non-traffic sources can be important during summer months. The m,p-xylene-to-ethylbenzene ratio (X/E) pointed to transport of organic compounds from high-emission districts of the city. Positive matrix factorization applied to data revealed four sources, including gasoline exhaust, solvent evaporation, diesel emissions and a local laboratory source, contributing to VOC concentrations. Strengths of these sources, particularly solvent source, on total VOC concentrations showed seasonal differences. Source contributions on light and heavy VOCs were also different.

Yurdakul, Sema; Civan, Mihriban; Tuncel, Gürdal

2013-02-01

373

Deposition of terpenes to vegetation - a paradigm shift towards bidirectional VOC exchange?  

NASA Astrophysics Data System (ADS)

Biogenic volatile organic compounds (BVOCs) are important precursors for secondary organic aerosol (SOA) formation (Hallquist et al., 2009). In addition reactive BVOCs play a crucial role in local tropospheric ozone production (Atkinson, 2000). According to the present scientific understanding vegetation is recognized as a major VOC emission source rather than a deposition sink. Our recent observations however demonstrate that an uptake of terpene compounds to mountain grassland can be significant - at least under certain atmospheric conditions. After a severe hailstorm volume mixing ratios (VMR) of locally emitted terpene compounds originating from conifers located at the mountain slopes were strongly enhanced, even during daytime hours. Weeks after the hailstorm our PTR-MS and PTR-time-of-flight (PTR-TOF) instruments still measured deposition fluxes of monoterpenes (m/z 137.133), sesquiterpenes (m/z 205.195), and oxygenated terpenes (m/z 153.128) to the grassland. The total amount of terpenoids (on a carbon basis) deposited to the grassland during the weeks after the hailstorm is comparable to the total methanol emission of the entire growing season (Bamberger et al., 2011). These findings pose the question whether the terminology should be adjusted from VOC emission to VOC exchange.

Bamberger, I.; Hörtnagl, L.; Ruuskanen, T.; Schnitzhofer, R.; Müller, M.; Graus, M.; Karl, T.; Wohlfahrt, G.; Hansel, A.

2012-04-01

374

Paso del Norte ozone study VOC measurements, 1996  

SciTech Connect

The results of VOC determinations of ambient air samples collected at surface air quality monitoring sites and near sources of interest on the US and Mexican side of the border during six weeks of the 1996 Paso del Norte Ozone Study are reported. Carbonyl samples were collected on DNPH impregnated cartridges at three surface sites and analyzed by HPLC to quantify 13, C-1 to C-8 species. Whole air samples were collected in electro-polished stainless steel canisters which were returned to laboratory for determination of C-2 to C-10+ hydrocarbons by cryogenic preconcentration capillary gas chromatography with flame ionization detection (gc-fid). Several sources were sampled: rush hour traffic, propane-powered bus exhaust, automobile paint shop emissions, propane fuel, petroleum refinery, and industrial manufacturing site. Spatial and temporal characteristics of VOC species concentrations and compositions are presented. Overall surface TNMOC values ranged from 0.1 to 3.4 ppmC with the highest concentrations recorded in the morning at three vehicle-dominated sites, two in Cuidad Juarez and one in downtown El Paso. Toluene in El Paso samples and propane, which is used as a cooking and transportation fuel in Cuidad Juarez, were the most abundant hydrocarbons.

Seila, R.L.; Main, H.; Arriaga, J.L.; Martinez, G.V.; Ramadan, A.B.

1999-01-01

375

Paso del Norte ozone study VOC measurements, 1996  

SciTech Connect

The results of VOC determinations of ambient air samples collected at surface air quality monitoring sites and near sources of interest on the US and Mexican side of the border during six weeks of the 1996 Paso del Norte Ozone Study are reported. Carbonyl samples were collected on DNPH impregnated cartridges at three surface sites and analyzed by HPLC to quantify 13, C-1 to C-8 species. Whole air samples were collected in electro-polished stainless steel canisters which were returned to laboratory for determination of C-2 to C-10+ hydrocarbons by cryogenic preconcentration capillary gas chromatography with flame ionization detection (gc-fid). Several sources were sampled: rush hour traffic, propane-powered bus exhaust, automobile paint shop emissions, propane fuel, petroleum refinery, and industrial manufacturing site. Spatial and temporal characteristics of VOC species concentrations and compositions are presented. Overall surface TNMOC values ranged from 0.1 to 3.4 ppmC with the highest concentrations recorded in the morning at three vehicle-dominated sites, two in Cuidad Juarez and one in downtown El Paso. Toluene in El Paso samples and propane, which is used as a cooking and transportation fuel in Cuidad Juarez, were the most abundant hydrocarbons.

Seila, R.L.; Main, H.; Arriaga, J.L.; Martinez, G.V.; Ramadan, A.B.

1999-11-01

376

Volatile Organic Compound Emissions from Dairy Facilities in Central California  

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

377

EMISSIONS ASSESSMENT OF CONVENTIONAL STATIONARY COMBUSTION SYSTEMS: VOLUME IV. COMMERCIAL/INSTITUTIONAL COMBUSTION SOURCES  

EPA Science Inventory

The report characterizes air emissions from commercial/institutional external combustion sources and reciprocating engines and is the fourth of a series of five project reports characterizing emissions from conventional combustion sources. This characterization was based on a cri...

378

62 FR 2722 - National Emission Standards for Hazardous Air Pollutants for Source Categories: Organic Hazardous...  

Federal Register 2010, 2011, 2012, 2013

...63 National Emission Standards for Hazardous Air Pollutants for Source Categories: Organic Hazardous Air Pollutants From the Synthetic Organic Chemical...2060-AC19 National Emission Standards for Hazardous Air Pollutants for Source Categories:...

1997-01-17

379

REVISED EMISSIONS ESTIMATION METHODOLOGIES FOR INDUSTRIAL, RESIDENTIAL, AND ELECTRIC UTILITY STATIONARY COMBUSTION SOURCES  

EPA Science Inventory

The report describes the development of improved and streamlined EPA emission estimation methods for stationary combustion area sources by the Joint Emissions Inventory Oversight Group (JEIOG) research program. hese sources include categories traditionally labeled "other stationa...

380

REVISED EMISSIONS ESTIMATION METHODOLOGIES FOR INDUSTRIAL, RESIDENTIAL, AND ELECTRIC UTILITY STATIONARY COMBUSTION SOURCES  

EPA Science Inventory

The report describes the development of improved and streamlined EPA emission estimation methods for stationary combustion area sources by the Joint Emissions Inventory Oversight Group (JEIOG) research program. These sources include categories traditionally labeled "other statio...

381

40 CFR 49.128 - Rule for limiting particulate matter emissions from wood products industry sources.  

Code of Federal Regulations, 2013 CFR

...following wood products industry sources: (1... (c) What are the PM10 emission limits for wood products industry sources? These...not in lieu of, the particulate matter...emissions from direct natural gas fired or...

2013-07-01

382

Regional, new-source bubble policy for sulfur dioxide emissions in the eastern United States  

Microsoft Academic Search

This report presents an analysis of an atmospheric emissions control strategy that has the potential to reduce both costs and emissions relative to current regulations: the regional new-source bubble policy. Under a bubble (a single regulatory constraint on total emissions), a group of individual sources can choose lower-cost means of controlling their emissions. The particular strategy addressed in this report

D. G. Streets; P. J. Grogan; D. A. Hanson; T. D. Veselka

1983-01-01

383

A GIS-based approach to spatial allocation of area source solvent emissions  

Microsoft Academic Search

Current area source emission inventories estimate total emissions for various industrial, commercial, and consumer activities at the county or higher levels. The lack of emission estimates at subcounty levels severely limits the modeling and planning capabilities in urban and regional air quality management. This paper extends current area source emission inventory methodology by developing a geographical information system (GIS) based

Jian J. Dai; David M. Rocke

2000-01-01

384

Scenarios of global mercury emissions from anthropogenic sources  

NASA Astrophysics Data System (ADS)

This paper discusses the impact of air quality and climate policies on global mercury emissions in the time horizon up to 2050. Evolution of mercury emissions is based on projections of energy consumption for a scenario without any global greenhouse gas mitigation efforts, and for a 2 °C climate policy scenario, which assumes internationally coordinated action to mitigate climate change. The assessment takes into account current air quality legislation in each country, as well as provides estimates of maximum feasible reductions in mercury through 2050. Results indicate significant scope for co-benefits of climate policies for mercury emissions. Atmospheric releases of mercury from anthropogenic sources under the global climate mitigation regime are reduced in 2050 by 45% when compared to the case without climate measures. Around one third of world-wide co-benefits for mercury emissions by 2050 occur in China. An annual Hg-abatement of about 800 tons is estimated for the coal combustion in power sector if the current air pollution legislation and climate policies are adopted in parallel.

Rafaj, P.; Bertok, I.; Cofala, J.; Schöpp, W.

2013-11-01

385

Measurement of the VOC Environment from an Aircraft Platform during an Aerosol-Cloud Interaction Study Near Oklahoma City  

NASA Astrophysics Data System (ADS)

The interaction and relationship between atmospheric aerosols and ambient VOC concentrations is a current area of activity in atmospheric research both in urban and remote environments. Current atmospheric models seriously under predict the amount of secondary organic aerosol (SOA), highlighting the importance of simultaneous particle and VOC measurements and their importance to climate change models. The Cumulus Humilis Aerosol Processing Study (CHAPS) campaign was conducted in June of 2007 near Oklahoma City to investigate the mutual interaction of anthropogenic aerosols and clouds on each other. An important part of this study was characterizing the temporally and spatially resolved VOC environment in which urban aerosols and cumuliform clouds in the Oklahoma City environment exist. We report results from the proton transfer reaction mass spectrometer (PTR-MS) aboard the DOE Gulfstream 1 (G1) research aircraft to perform time-resolved measurements of the ambient VOC species and concentrations in conjunction with the suite of aerosol, trace gas and meteorological instruments aboard the G1. Several classes of VOC's were observed. Benzene, toluene, C2-benzenes and other species indicative of primary urban emissions were found in the Oklahoma City plume, strongly correlated with CO and other inorganic urban trace gases. Oxygenated species such as methanol, acetone and acetaldehyde were observed with no well defined spatial or temporal variation. Finally, species typical of biogenic emissions, isoprene and its oxidation products were seen in broad but definite spatial distributions, not correlated with the urban gas phase products as measured with the PTR-MS and other instrumentation. The concentration levels of these species and possible ground-based sources will be investigated and reported in this presentation. Correlation with aerosol instrumentation such as the Aerodyne aerosol mass spectrometer (AMS), nephelometer and other optical measurements will also be reported, both within and out of cloud environments. These correlations will be examined for possible influences of the local VOC species on the cloud-aerosol systems under study.

Alexander, M. L.; Newburn, M.; Hubbe, J.; Berg, L.; Berkowitz, C.; Springston, S.; Senum, G.; Lee, Y.; Andrews, E.

2007-12-01

386

Emission database for global atmospheric research (Edgar)  

Microsoft Academic Search

Atmospheric chemistry and climate modellers require gridded global emissions data as input into their models. To meet this urgent need a global emissions source database called EDGAR is being developed by TNO and RIVM to estimate for 1990, on a regional and on a grid basis, annual emissions of greenhouse gases (CO2, CH4, N2O, CO, NOx, non-methane VOC, SOx), of

J. G. J. Olivier; A. F. Bouwman; C. W. M. Maas; J. J. M. Berdowski

1994-01-01

387

SETTING PRIORITIES FOR CONTROL OF FUGITIVE PARTICULATE EMISSIONS FROM OPEN SOURCES  

EPA Science Inventory

The report describes setting priorities for controlling fugitive particulate emissions. Emission rate estimates of suspended particulates from open sources in the U.S. were obtained from emission factors and source extents in the literature. Major open sources, with their estimat...

388

Halocarbon sources and emissions in the western Pacific  

NASA Astrophysics Data System (ADS)

Natural, short-lived halocarbons play a role in the stratospheric ozone budget, besides the anthropogenic emitted, long-lived chlorine- and brominefluorocarbons. The tropical oceans are a known source of reactive iodine and bromine to the atmosphere in the form of iodinated and brominated methanes (VSLS), as e.g.methyl iodide (CH3I), dibromomethane (CH2Br2) and bromoform (CHBr3), which contributes to reactive bromine within the lower stratosphere. Elevated atmospheric concentrations above the oceans are related to oceanic supersaturations of the compounds, caused by photochemical and biological production. The tropical Western Pacific is of special interest since it is a largely uncharacterized region for the oceanic compounds and in certain regions a projected hot spot for their emissions and transport pathways into the stratosphere. From 9 to 25 October 2009 the IFM-GEOMAR (Kiel, Germany) conducted a cruise with RV Sonne in the tropical western Pacific to investigate trace gas emissions on a 4030 nm (7,500 km) and 60 degrees latitude covering transit between Tomakomai (Japan, 42°35,4‘N/ 141°37,5‘E) and Townsville (Australia, 19°06,6'S/ 146°50,5‘E). The ships cruise crossed various biogeochemical regimes of the northern and southern western Pacific Ocean, which differ in seawater properties, currents, productivity and atmospheric dynamics (e.g. Kuroshio Front, Northern Pacific Gyre, Pacific warm pool and Coral Seas). We will present highlights of the oceanic and atmospheric halocarbon measurements during the ships campaign, halocarbon emissions from the western Pacific Ocean, sources and the relationship between VSLS emissions and various phytoplankton functional groups, as being derived from in situ and satellite measurements.

Quack, Birgit; Atlas, Elliot; Bracher, Astrid; Dinter, Tilman; Wache, Sebastian; Wallace, Doug; Krüger, Kirstin

2010-05-01

389

Formaldehyde Source Attribution in Houston during TexAQS II and TRAMP  

Microsoft Academic Search

To determine the relative importance of primary vs secondary formaldehyde in Houston, source apportionment was performed on continuous online measurements of VOCs, formaldehyde (HCHO), CO, SO2, and HONO at one urban and two industrial sites. The results of source apportionment were used in conjunction with the meteorological, emission inventory, emission event, and back trajectory data catalogued in Air Research Information

B. Guven; E. P. Olaguer

2010-01-01

390

Source signature of volatile organic compounds from oil and natural gas operations in northeastern Colorado.  

PubMed

An extensive set of volatile organic compounds (VOCs) was measured at the Boulder Atmospheric Observatory (BAO) in winter 2011 in order to investigate the composition and influence of VOC emissions from oil and natural gas (O&NG) operations in northeastern Colorado. BAO is 30 km north of Denver and is in the southwestern section of Wattenberg Field, one of Colorado's most productive O&NG fields. We compare VOC concentrations at BAO to those of other U.S. cities and summertime measurements at two additional sites in northeastern Colorado, as well as the composition of raw natural gas from Wattenberg Field. These comparisons show that (i) the VOC source signature associated with O&NG operations can be clearly differentiated from urban sources dominated by vehicular exhaust, and (ii) VOCs emitted from O&NG operations are evident at all three measurement sites in northeastern Colorado. At BAO, the reactivity of VOCs with the hydroxyl radical (OH) was dominated by C(2)-C(6) alkanes due to their remarkably large abundances (e.g., mean propane = 27.2 ppbv). Through statistical regression analysis, we estimate that on average 55 ± 18% of the VOC-OH reactivity was attributable to emissions from O&NG operations indicating that these emissions are a significant source of ozone precursors. PMID:23316938

Gilman, J B; Lerner, B M; Kuster, W C; de Gouw, J A

2013-01-25

391

SOURCE: The Solar Ultraviolet Radiation and Correlative Emissions Mission  

NASA Astrophysics Data System (ADS)

The Solar Ultraviolet Radiation and Correlative Emissions (SOURCE) mission is intended to advance our ability to specify the spectral irradiance of the Sun in the extreme ultraviolet (EUV) wavelength range through simultaneous, radiometrically accurate measurements of the solar EUV spectral irradiance and measurements, including EUV and visible images, of solar parameters that are correlated with the EUV flux. The data will be used in combination with empirical modelling to develop and validate a more accurate system of proxy, or surrogate, indices for the solar EUV flux.

Smith, P. L.; Lean, J. L.; Christensen, A. B.; Harvey, K. L.; Judge, D. L.; Moore, R. L.; Torr, M. R.; Woods, T. N.

1993-01-01

392

Acoustic emission from single point machining: Part 1, Source mechanism  

SciTech Connect

Acoustic emission (AE) was monitored during single point, continuous machining of 4340 steel and Ti-6A1-4V as a function of heat treatment. Heat treatments which increase the strength of 4340 steel increase the amount of AE produced during deformation, while heat treatments which increase the strength of Ti-6A1-4V decrease the amount of AE produced during deformation. Trends in rms AE level during machining with increasing strength were similar for both alloys, demonstrating that chip deformation is not a major source of AE in sigle point machining. The data suggest that sliding friction between the nose and/or flank of the tool and the newly machined surface is the primary source of AE.

Heiple, C.R.; Carpenter, S.H.; Armentrout, D.L.; McManigle, A.P.

1989-01-01

393

Destruction of halogenated VOCs using premixed radiant burner  

SciTech Connect

The paper describes the destruction of halogenated volatile organic compounds (VOCs) using a premixed radiant burner. Alzeta Corporation has developed a natural-gas-fired thermal oxidizer to provide emission control for industrial exhaust streams where stringent emisson limits of VOCs are required. Measurements, made with assistance of the U.S. EPA at Research Triangle Park, NC, show destruction efficiencies (DEs) between 99.9766 and 99.999% for eight common halogenated compounds. A brief discussion of pertinent regulations and emissions of concern is presented. The EPA test program is presented with results. Three similarly designed commercial thermal oxidizers are described, including emission test results.

Bartz, D.F.; Marshall, B.N.; Bruce, K.; Lombardo, A.; Lee, C.W.

1996-06-01

394

Off-axis viewing of radiation emission by long wiggler sources  

SciTech Connect

When high-brilliance radiation is needed for experiments, insertion device sources are generally viewed on-axis. Off-axis emission of flux can be prodigious especially from wiggler sources having large emission fans. The on-axis and off-axis radiation emission characteristics from insertion device sources have been calculated extensively and are well known, but experimental verifications of some characteristics, particularly those associated with off-axis emission, are relatively few. Here measurements of the flux spectrum and apparent source size are described, as a function of horizontal emission angle, from the former X25 hybrid wiggler at the National Synchrotron Light Source (NSLS).

Berman, L.; Yin, Z.

2011-01-01

395

Sources and emission of greenhouse gases in Danube Delta lakes.  

PubMed

Production of methane and carbon dioxide as well as methane concentrations in surface waters and emissions to the atmosphere were investigated in two flow-through lake complexes (Uzlina-Isac and Puiu-Rosu-Rosulet) in the Danube Delta during post-flood conditions in May and low water level in September 2006. Retained nutrients fueled primary production and remineralization of bioavailable organic matter. This led to an observable net release of methane, particularly in the lakes Uzlina, Puiu and Rosu in May. Input from the Danube River, from redbuds and benthic release contributed to CH(4) concentrations in surface waters. In addition to significant river input of CO(2), this trace gas was released via aerobic remineralization within the water column and in top sediments. Emission patterns of CO(2) widely overlapped with those of CH(4). Generally, greenhouse gas emissions peaked in the lake complex adjacent to the Danube River in May due to strong winds and decreased with increasing hydrological distance from the Danube River. Intense remineralization of organic matter in the Danube Delta lakes results in a net source of atmospheric greenhouse gases. PMID:19506929

Pavel, Alina; Durisch-Kaiser, Edith; Balan, Sorin; Radan, Silviu; Sobek, Sebastian; Wehrli, Bernhard

2009-06-09

396

Open-path Emission Factors Derived from DOAS and FTIR Measurements in the Mexico City Metropolitan Area  

Microsoft Academic Search

Mobile sources are responsible for about 50% of VOC (volatile organic compounds) and about 70% of NOx emissions in the Mexico City Metropolitan Area (MCMA). A novel approach has been developed to derive emission factors for mobile sources that are representative of the overall vehicle fleet, using collocated open-path Differential Optical Absorption Spectroscopy (DOAS) and Fourier Transform Infrared (FTIR) spectroscopic

E. Flores; M. Grutter; B. Galle; J. Mellqvist; J. Samuelsson; B. Knighton; B. T. Jobson; R. Volkamer; L. T. Molina; M. J. Molina

2004-01-01

397

Mercury Emission from Anthropogenic Sources in Poland and Their Scenarios to the Year 2020  

Microsoft Academic Search

This paper reviews the current state of knowledge regarding sources of anthropogenic mercury emission in Poland for the year\\u000a 2005 and presents projection of mercury emission in perspective to the year 2020. These projections are treated separately\\u000a as emissions from by-product sources and from product use since abatement strategies for these two source categories are very\\u000a different. Emission projections until

Anna Glodek; Damian Panasiuk; Jozef M. Pacyna

2010-01-01

398

Progress in ultrasonic measurements research in 1990: Transient sources for acoustic emission work  

Microsoft Academic Search

Many techniques have been used by acoustic emission workers to produce rapid transient disturbances in elastic media. Techniques employing transient sources are necessary for characterizing many acoustic emission system components such as receiving transducers, transfer media, and other sources as well. Wave forms from seven types of sources were studied by performing experiments in which the source and a high

F. R. Breckenridge; T. M. Proctor; N. N. Hsu; S. E. Frick; D. G. Eitzen

1990-01-01

399

The Optical Emission from Ultraluminous X-ray Sources  

NASA Astrophysics Data System (ADS)

Ultraluminous X-ray sources (ULXs) are point-like, non-nuclear sources which exceed the Eddington luminosity for a stellar mass black hole (BH). The emission from these sources might be beamed or super-Eddington, but it has also been proposed that the compact object in these sources are intermediate mass BHs (IMBHs), which fit in the mass range between the two known populations of BH in the galaxy. The existence of IMBHs is under intense debate, and study of the X-ray data has been unable to resolve this issue. This thesis describes a model I have constructed in order to examine the optical/IR emission from these sources; an alternative channel by which their nature may be understood. I assume a binary model with a black hole accreting matter from a Roche lobe filling companion star. I consider the effects of radiative transport and radiative equilibrium in the irradiated surfaces of both the star and a thin accretion disc. I use current stellar evolutionary models as an input component in this model, and hence determine the mass, radius and age of the donor stars in a range of ULX systems, and in some cases provide limits on the BH mass. In addition I determine the mass transfer rate in these systems from the X-ray luminosity and compare this to transfer rate calculations based on the stellar evolutionary models. Since this method is independent of the optical data it is a powerful additional constraint on the parameter space. For systems where optical observations are available at multiple epochs, I make further determinations of the binary parameters based on the optical variability. Where it is possible to constrain the masses of the BHs, I find them to be consistent with BHs of up to ~100 Msun. I find that in general the donor stars are older and less massive than previously thought, and are consistent with being of spectral type B. I discuss how these results affect our understanding of the evolution and history of ULXs. I discuss how future studies of ULX optical counterparts will be even more revealing, and I make predictions for these optical campaigns, estimating binary periods, variability and the results of IR observational campaigns, which my results suggest will be a important tool in future studies of the nature of this class of sources.

Copperwheat, C. M.

2007-11-01

400

The VOC-ozone connection: a grassland case study  

NASA Astrophysics Data System (ADS)

Tropospheric ozone (O3) is formed in the presence of sunlight through the interaction of volatile organic compounds (VOCs) and NOX (NO, NO2). A photochemical equilibrium exists between NO, NO2 and O3; however in the presence of VOCs this equilibrium is broken and additional O3 is produced. O3 damages plants in several ways, most importantly by reducing net photosynthesis and growth. The extent of this damage depends on the time-integrated absorbed O3 flux (i.e. the dose), which is a function of leaf stomatal conductance and ambient O3 concentration, and further influenced by plant species specific defence mechanisms. VOCs are produced by plants through a variety of pathways and in response to large number of different driving forces. A large variety of VOCs are emitted by plants in response to stress conditions, including the foliar uptake of O3. Here we present preliminary data from an ongoing study where concurrent measurements of the fluxes of VOCs and O3 are made above a managed mountain grassland in Tyrol/Austria. Fluxes of several different VOCs are measured by means of the eddy covariance method and a proton transfer reaction mass spectrometer (PTR-MS). Fluxes of O3 are measured by both the eddy covariance method and a modified Bowen-ratio approach. The data analysis will try to identify whether VOC emissions change with the time-integrated uptake of O3 by plants.

Wohlfahrt, G.; Hoertnagl, L.; Bamberger, I.; Schnitzhofer, R.; Dunkel, J.; Hammerle, A.; Graus, M.; Hansel, A.

2008-12-01

401

Applications of open-path Fourier transform infrared for identification of volatile organic compound pollution sources and characterization of source emission behaviors.  

PubMed

An open-path Fourier transform infrared spectroscopy (OP-FTIR) system was set up for 3-day continuous line-averaged volatile organic compound (VOC) monitoring in a paint manufacturing plant. Seven VOCs (toluene, m-xylene, p-xylene, styrene, methanol, acetone, and 2-butanone) were identified in the ambient environment. Daytime-only batch operation mode was well explained by the time-series concentration plots. Major sources of methanol, m-xylene, acetone, and 2-butanone were identified in the southeast direction where paint solvent manufacturing processes are located. However, an attempt to uncover sources of styrene was not successful because the method detection limit (MDL) of the OP-FTIR system was not sensitive enough to produce conclusive data. In the second scenario, the OP-FTIR system was set up in an industrial complex to distinguish the origins of several VOCs. Eight major VOCs were identified in the ambient environment. The pollutant detected wind-rose percentage plots that clearly showed that ethylene, propylene, 2-butanone, and toluene mainly originated from the tank storage area, whereas the source of n-butane was mainly from the butadiene manufacturing processes of the refinery plant, and ammonia was identified as an accompanying reduction product in the gasoline desulfuration process. Advantages of OP-FTIR include its ability to simultaneously and continuously analyze many compounds, and its long path length monitoring has also shown advantages in obtaining more comprehensive data than the traditional multiple, single-point monitoring methods. PMID:18581812

Lin, Chitsan; Liou, Naiwei; Sun, Endy

2008-06-01

402

Particle number emissions and source signatures of an industrial facility.  

PubMed

The work presented was conducted within the scope of a larger study investigating impacts of the Stuart Oil Shale project, a facility operating to the north of the industrial city of Gladstone, Australia. The aims of the investigations were threefold: (a) the identification of the plant signatures in terms of particle size distributions in the submicrometer range (13-830 nm) through stack measurements, (b) exploring the applicability of these signatures in tracing the source contributions at locations of interest, at a distance from the plant, and (c) assessing the contribution of the plant to the total particle number concentration at locations of interest. The stack measurements conducted for three different conditions of plant operation showed that the particle size distributions were bimodal with average modal count median diameters (CMDs) of 24 (SD 4) and 52 (SD 9) nm. The average of all the particle size distributions recorded within the plant sector at a site located 4.5 km from the plant, over the sampling period when the plant was operating, also showed a bimodal distribution. The modal CMDs in this case were 27 and 50 nm, similar to those at the stack. This bimodal size distribution is distinct from the size distribution of the most common ambient anthropogenic emission source, which is vehicle emissions, and can be considered as a signature of this source. The average contribution of the plant (for plant sector winds) was estimated to be (10.0 +/- 3.8) x 10(2) particles cm(-3) and constituted approximately a 50% increase overthe local particle ambient concentration for plant sector winds. This increase in particle number concentration compared to the local background concentration, while high compared to the clean environment concentration, is not significant when compared to concentrations generally encountered in the urban environment of Brisbane. PMID:16509322

Morawska, L; Johnson, G R; He, C; Ayoko, G A; Lim, M C H; Swanson, C; Ristovski, Z D; Moore, M

2006-02-01

403

Stress-induced biogenic VOC emissions from typical European tree species, their impact on secondary organic aerosol formation and possible climate feedbacks  

NASA Astrophysics Data System (ADS)

Biogenic volatile organic compounds (BVOC) are precursors of secondary organic aerosols (SOA), which can scatter and absorb radiation. BVOC therefore indirectly impact the Earth's climate. Earth's climate is projected to change, possibly putting and vegetation under stress due to intensive heat and drought periods. Such stress situations will alter BVOC emissions that may induce feedbacks between vegetation and climate change. The main aim of our study is to determine whether such effect exists. A first step was to determine the impacts of drought and heat on BVOC emissions and subsequent SOA formation. Experiments were performed in the Juelich plant atmosphere chamber. Pine and Spruce were taken as representatives for species exhibiting storage organs for monoterpenes (MT). Beech and Birch were used as species with MT emissions closely coupled to CO2 uptake. The plants were stored under well-defined conditions of temperature and light intensity. Heat stress was induced by increasing the chamber temperature; drought stress was induced by not irrigating the plants. A fraction of the air leaving the plant chamber was fed into a reaction chamber where SOA formation was induced by OH-initiated oxidation. During stress situations the plants' BVOC emissions changed significantly. As a general feature we found that combined heat and drought stress increased MT emissions from conifers but decreased MT emissions from the broadleaf species. The former was attributed to a heat-induced breakdown of storage organs. The latter was attributed to a general breakdown of biosynthetic activity. SOA formation potentials were changed together with the MT emissions. The decrease in SOA formation potential due to the decrease of MT emissions from broadleaf species was amplified by additional emissions of green leaf volatiles (GLV). Obviously, GLV can suppress SOA formation by suppressing OH concentrations. GLV were also emitted from the conifers under heat stress. However the contribution of GLV to the BVOC mix was too low to suppress SOA formation significantly. Therefore, increases of MT emissions from heat stressed conifers followed by an increased SOA formation potential might be seen as a process leading to a negative climate feedback. This hypothesis was contested by the observation of a heat stress induced breakdown of pathogen-induced BVOC emissions. Conifers infested by aphids showed strong emissions of SQT and BVOC synthesized downstream of the shikimate pathway. Also these emissions are closely coupled to the CO2 uptake. Hence, these emissions vanished after heat stress causing a strong decrease of the SOA formation potential. At this stage it is difficult to assess whether heat and drought stress cause a negative or a positive feedbacks between vegetation and climate. Nevertheless, we conclude that such feedbacks exist. Key words: BVOC, SOA formation

Kleist, E.; Mentel, T. F.; Andres, S.; Dal Maso, M.; Hohaus, T.; Kindler-Scharr, A.; Rudich, Y.; Springer, M.; Tillmann, R.; Uerlings, R.; Wahner, A.; Wildt, J.

2011-12-01

404

Catalog of materials as potential sources of indoor air emissions. Volume 1. Insulation, wallcoverings, resilient floor coverings, carpet, adhesives, sealants and caulks, and pesticides. Final report, September 1991-September 1992  

SciTech Connect

The catalog presents a discussion of and data on constituents and emissions from products that have the potential to impact the indoor air environment. The Catalog is intended as a tool to be used by researchers to help organize the study of materials as potential sources of indoor air emmisions. Included in the catalog are sections on seven product categories: insulation, wallcoverings, resilient floor coverings, carpet, adhesives, sealants and caulks, and pesticides. Each section presents a classification scheme for the product category, sales and usage volume data, qualitative data on product composition, and quantitative and qualitative data on emission rates to the indoor air. Emissions information is presented only for volatile organic compounds (VOCs) because these are the compounds most likely to be emitted from materials found in homes and office buildings. Data tables summarizing available emissions and constituent data are provided, and are organized according to the classification scheme presented for each product category.

Leininger, A.E.; Scott, K.A.; Sarsony, E.C.; Huff, L.C.; Blackley, C.R.

1993-06-01

405

An overview of key emissions sources and ambient pollution characteristics from major cities in North America  

NASA Astrophysics Data System (ADS)

Many urban anthropogenic emission sources are difficult to characterize. They can be distributed across a spatial scale that precludes specific vector sampling. Others are difficult to identify a specific point of emissions. Novel emissions quantification methods, including fuel-based emission indicies and tracer flux ratio, are described and evaluated for a variety of urban pollution sources. These techniques can be used to quantify emissions for a large range of species including methane and carbon dioxide isotopes, formaldehyde and other toxic volatile organic carbon compounds, nitrogen oxides, carbon monoxide and black carbon particulate matter. Results from urban emissions source case-studies using a mobile laboratory either alone or in conjunction with tracer-release will be described. These include on road light duty and heavy duty vehicle emissions, in-use aircraft engine emissions at airports, and industrial emission sources.

Herndon, Scott; Fortner, Edward; Knighton, Berk; Floerchinger, Cody; Yacovitch, Tara; Roscioli, Rob; Zahniser, Mark; Nelson, David; Kolb, Charles; Zavala, Miguel; Molina, Luisa

2013-04-01

406

Uptake of VOC by sunflower  

NASA Astrophysics Data System (ADS)

To study potential VOC uptake by plants we exposed sunflower (Helianthus annuus) to different VOC in continuously stirred tank reactors. For many VOC like methanol, ethanol, acetone, methylvinylketone, isoprene or limonene no uptake was detectable within the accuracy of our analytic set up. Other VOC like hexanal, octanal, (E)-3-hexenol and nopinone were taken up by sunflower. The uptake was related to stomatal aperture. Obviously, these VOC enter the plants through stomata. In case of hexanal, octanal, and (E)-3-hexenol the uptake was only limited by stomatal aperture implying that these VOC are rapidly metabolised. For nopinone the uptake seems to be limited by a slow metabolization. Estimations of deposition velocities showed that dry deposition of these compounds cannot be neglected as sink if diffusion through stomata is the limiting step for dry deposition. In such cases the lifetime with respect to dry deposiotion is comparable to the lifetime with respect to oxidation by hydroxyl radicals.

Folkers, A.; Miebach, M.; Kleist, E.; Wildt, J.

2003-04-01

407

Alternate programs to control leaks of volatile organic compounds (VOC) from petroleum refining equipment  

SciTech Connect

Over 100 refineries are presently subject to state or local regulations covering fugitive VOC emissions. Most state and local regulations provide refiners the opportunity to request and use alternate monitoring methods, schedules, and control techniques provided the proposed alternatives achieve equivalent or greater emission reduction. The impetus of this paper is to present information on equivalent methods that have been demonstrated since promulgation of state and local regulations to control refinery equipment leaks. EPA has published valuable information on alternative control techniques and the emission reductions they achieve. The refining industry is now joined by the gas processing, synthetic organic chemical manufacturing, and polymers manufacturing industries in fugitive control VIA source performance standards (NSPS) or recently released CTG'S. This paper recommends that both control agencies and facility operators utilize the information contained in these documents and the information contained in facility records to modify current programs to achieve greater emission reductions and lower annualized costs.

Norton, R.L.; Cole, D.G.; Rhoads, T.W.

1984-01-01

408

Imaging of the Explosive Emission Cathode Plasma in a Vircator High-Power Microwave Source  

Microsoft Academic Search

Most pulsed high-power microwave sources use explosive electron emission cathodes to generate high current electron beams. In the explosive emission process, the current emitted through small field emission points becomes high enough to cause the cathode material to vaporize and form a plasma. Plasma characteristics, such as uniformity and expansion rate, will affect the performance of the microwave source. High-speed

John Walter; John Mankowski; James Dickens

2008-01-01

409

X-RAY EMISSION FROM THE SOMBRERO GALAXY: DISCRETE SOURCES  

SciTech Connect

We present a study of discrete X-ray sources in and around the bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival Chandra observations with a total exposure of {approx}200 ks. With a detection limit of L{sub X} {approx} 10{sup 37} erg s{sup -1} and a field of view covering a galactocentric radius of {approx}30 kpc (11.'5), 383 sources are detected. Cross-correlation with Spitler et al.'s catalog of Sombrero globular clusters (GCs) identified from HST/ACS observations reveals 41 X-ray sources in GCs, presumably low-mass X-ray binaries (LMXBs). Metal-rich GCs are found to have a higher probability of hosting these LMXBs, a trend similar to that found in elliptical galaxies. On the other hand, the four most luminous GC LMXBs, with apparently super-Eddington luminosities for an accreting neutron star, are found in metal-poor GCs. We quantify the differential luminosity functions (LFs) for both the detected GC and field LMXBs, whose power-law indices ({approx}1.1 for the GC-LF and {approx}1.6 for field-LF) are consistent with previous studies for elliptical galaxies. With precise sky positions of the GCs without a detected X-ray source, we further quantify, through a fluctuation analysis, the GC-LF at fainter luminosities down to 10{sup 35} erg s{sup -1}. The derived index rules out a faint-end slope flatter than 1.1 at a 2{sigma} significance, contrary to recent findings in several elliptical galaxies and the bulge of M31. On the other hand, the 2-6 keV unresolved emission places a tight constraint on the field LF, implying a flattened index of {approx}1.0 below 10{sup 37} erg s{sup -1}. We also detect 101 sources in the halo of Sombrero. The presence of these sources cannot be interpreted as galactic LMXBs whose spatial distribution empirically follows the starlight. Their number is also higher than the expected number of cosmic active galactic nuclei (52 {+-} 11 [1{sigma}]) whose surface density is constrained by deep X-ray surveys. We suggest that either the cosmic X-ray background is unusually high in the direction of Sombrero, or a distinct population of X-ray sources is present in the halo of Sombrero.

Li Zhiyuan; Jones, Christine; Forman, William R.; Kraft, Ralph P.; Stefano, Rosanne Di [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Spitler, Lee R. [Centre for Astrophysics and Supercomputing, Swinburne University, Hawthorn, VIC 3122 (Australia); Tang, Shikui; Wang, Q. Daniel [Department of Astronomy, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 01003 (United States); Gilfanov, Marat [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str 1, 85741 Garching bei Muenchen (Germany); Revnivtsev, Mikhail, E-mail: zyli@cfa.harvard.ed [Excellence Cluster Universe, Technische Universitaet Muenchen, Boltzmannstr. 2, 85748 Garching (Germany)

2010-10-01

410

Dynamics and thermodynamics of fragment emission from excited sources  

SciTech Connect

In this paper we study the process of fragmentation of highly excited Lennard-Jones drops by studying the emission of stable fragments (clusters recognizable in configuration space that live more than a minimum lifetime). We focus on the dynamics and thermodynamics of the emitting sources and show, among other things, that this kind of process is a mixture of sequential and simultaneous events and that simultaneous events have a broad time distribution. We also show how a local equilibrium scenario comes up on top of expanding collective motion, allowing us to define and explore a local temperature, which turns out to be a strongly time-dependent quantity, signaling that we are facing an out-of-equilibrium process.

Ison, M.J.; Dorso, C.O. [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellon I, Ciudad Universitaria, Nunez, 1428, Buenos Aires (Argentina)

2005-06-01

411

Polar and non-polar volatile organic compounds (VOCs) in urban Algiers and saharian sites of Algeria  

NASA Astrophysics Data System (ADS)

For the first time, polar and non-polar organic compounds from C 4 to C 20 have been identified and quantified in one urban and two saharan sites located in Algeria. They were collected on adsorption traps filled with graphitic carbons and analyzed by high-resolution gas chromatography-mass spectrometry after thermal desorption. More than 190 compounds released by man-made and biogenic sources or formed in air by degradation of photochemical smog precursors were identified in the city center of Algiers. Some of them were never reported before. During our determinations, high levels of pollution characterized the city. Transport of anthropogenic pollutants together with some biogenic emission from date palm trees was mainly responsible for the levels of VOCs measured in Melika oasis located at the entrance of the Sahara desert. Background tropospheric levels of VOCs were instead detected in Bouchene sandy site of the Sahara desert where no biogenic sources were present.

Yassaa, Noureddine; Meklati, Brahim Youcef; Brancaleoni, Enzo; Frattoni, Massimiliano; Ciccioli, Paolo

412

Progress in Ultrasonic Measurements Research in 1990: Transient Sources for Acoustic Emission Work.  

National Technical Information Service (NTIS)

Many techniques have been used by acoustic emission workers to produce rapid transient disturbances in elastic media. Techniques employing transient sources are necessary for characterizing many acoustic emission system components such as receiving transd...

D. G. Eitzen F. R. Breckenridge N. N. Hsu S. E. Frick T. M. Proctor

1990-01-01

413

40 CFR Table 3 to Subpart Xxxx of... - Emission Limits for Puncture Sealant Application Affected Sources  

Code of Federal Regulations, 2012 CFR

...FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 3 Table 3 to Subpart XXXX of Part 63âEmission Limits for Puncture...

2012-07-01

414

40 CFR Table 2 to Subpart Xxxx of... - Emission Limits for Tire Cord Production Affected Sources  

Code of Federal Regulations, 2012 CFR

...FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX, Table 2 Table 2 to Subpart XXXX of Part 63âEmission Limits for Tire Cord...

2012-07-01

415

40 CFR Table 2 to Subpart Qqqq of... - Emission Limits for Existing Affected Sources  

Code of Federal Regulations, 2012 CFR

...POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Surface Coating of Wood Building Products Pt. 63, Subpt. QQQQ, Table 2 Table 2 to Subpart QQQQ of Part 63âEmission Limits for Existing...

2012-07-01

416

Regional, New-Source Bubble Policy for Sulfur Dioxide Emissions in the Eastern United States.  

National Technical Information Service (NTIS)

This report presents an analysis of an atmospheric emissions control strategy that has the potential to reduce both costs and emissions relative to current regulations: the regional new-source bubble policy. Under a bubble (a single regulatory constraint ...

D. G. Streets P. J. Grogan D. A. Hanson T. D. Veselka

1983-01-01

417

40 CFR Table 2 to Subpart Xxxx of... - Emission Limits for Tire Cord Production Affected Sources  

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Emission Limits for Tire Cord Production Affected Sources...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt...of Part 63âEmission Limits for Tire Cord Production Affected...

2009-07-01

418

40 CFR Table 2 to Subpart Xxxx of... - Emission Limits for Tire Cord Production Affected Sources  

Code of Federal Regulations, 2010 CFR

...2010-07-01 true Emission Limits for Tire Cord Production Affected Sources...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt...of Part 63âEmission Limits for Tire Cord Production Affected...

2010-07-01