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1

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...

2

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...

3

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

4

Mapping methane sources and emissions over California from direct airborne flux and VOC source tracer measurements  

NASA Astrophysics Data System (ADS)

Quantifying the contributions of methane (CH4) emissions from anthropogenic sources in the Central Valley of California is important for validation of the statewide greenhouse gas (GHG) inventory and subsequent AB32 law implementation. The state GHG inventory is largely based on activity data and emission factor based estimates. The 'bottom-up' emission factors for CH4 have large uncertainties and there is a lack of adequate 'top-down' measurements to characterize emission rates. Emissions from non-CO2 GHG sources display spatial heterogeneity and temporal variability, and are thus, often, poorly characterized. The Central Valley of California is an agricultural and industry intensive region with large concentration of dairies and livestock operations, active oil and gas fields and refining operations, as well as rice cultivation all of which are known CH4 sources. In order to gain a better perspective of the spatial distribution of major CH4 sources in California, airborne measurements were conducted aboard 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 low-altitude and mixed layer airborne CH4 and CO2 measurements alongside coincident VOC measurements. Transects during eight unique flights covered much of the Central Valley and its eastern edge, the Sacramento-San Joaquin delta and the coastal range. We report direct quantification of CH4 fluxes using real-time airborne Eddy Covariance measurements. CH4 and CO2 were measured at 1-Hz data rate using an instrument based on Cavity Ring Down Spectroscopy (CRDS) along with specific VOCs (like isoprene, methanol, acetone etc.) measured at 10-Hz using Proton Transfer Reaction Mass Spectrometer - Eddy Covariance (PTRMS-EC) flux system. Spatially resolved eddy covariance fluxes were obtained using the virtual disjunct eddy covariance method and from Wavelet Analysis along flight tracks flown in the mixed layer. Preliminary analysis of mixing ratio measurements indicate that high concentrations of CH4 occur consistently while flying above the Central Valley that are correlated to large enhancements of methanol which is an important dairy and livestock emissions tracer. The elevated CH4 mixing ratios along the eastern edge of the San Joaquin Valley highlight the contribution of topography and emissions transport to local ambient levels of CH4. Large enhancements of CH4, benzene and toluene are also observed while flying over the oil production facilities in western part of Kern county (state's top oil producing county, 10% of US production) suggesting the likelihood of fugitive emissions in the region. 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. Plumes from biomass burning, landfills and refineries encountered during different flights are also investigated. Eddy covariance based CH4 flux estimates are derived for various sources and compared with ';bottom-up' inventory estimates to verify/validate the CA methane inventory for major sources.

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

2013-12-01

5

Application of PMF in the Investigation of VOCs Emission Sources for Lake Champlain Basin  

NASA Astrophysics Data System (ADS)

Volatile Organic Compounds (VOCs) have long been considered hazardous atmospheric pollutants. VOCs account for the majority of the 188 air toxics species listed in the 1990 Clean Air Act (US). The National-Scale Air Toxics Assessment (NATA) Program established by EPA aims to coordinate national and state level efforts on concentration data collection, emission inventory, and population risk assessment. Like many other states, the State of Vermont established its Air Toxics Program which consists of seven monitoring sites, some of which started sample collection as early as 1993. This presentation focuses on an ongoing project to investigate emission sources of VOCs in the Lake Champlain Basin. Two monitoring sites, Burlington and Underhill sites were selected for their representation of two distinctly different urban and rural environments. Statistical methods including the Positive Matrix Factorization were employed. Identified likely sources, up to fourteen of them for each site, that are either common to both sites or unique to one of the two, as well as the apportionment results, will be discussed. In addition, the presentation will discuss particular challenges arisen in the source-receptor modeling processes due to low concentration levels of many VOCs, the absence of some very volatile species in the Vermont Air Toxics monitoring program, rapid chemical transformations or decompositions occurred during atmospheric transport of the VOCs, and the complexity and uncertainty in the emissions inventory.

Gao, N.; Anderson, K.; Poirot, R.

2009-04-01

6

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

7

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

8

Source Apportionment of VOCs in Edmonton, Alberta  

NASA Astrophysics Data System (ADS)

Regional emissions at Edmonton, Alberta, are complex, containing emissions from (1) transportation sources, such as cars, trucks, buses, and rail; (2) industrial sources, such as petroleum refining, light manufacturing, and fugitive emissions from holding tanks or petroleum terminals; and (3) miscellaneous sources, such as biogenic emissions and natural gas use and processing. From 2003 to 2009, whole air samples were collected at two sites in Edmonton and analyzed for over 77 volatile organic compounds (VOCs). VOCs were sampled in the downtown area (Central) and the industrial area on the eastern side of the city (East). Concentrations of most VOCs were highest at the East site. The positive matrix factorization (PMF) receptor model was used to apportion ambient concentration measurements of VOCs into eleven factors, which were associated with emissions source categories. Factors of VOCs identified in the final eleven-factor solution include transportation sources (both gasoline and diesel vehicles), industrial sources, a biogenic source, and a natural-gas-related source. Transportation sources accounted for more mass at the Central site than at the East site; this was expected because Central is in a core urban area where transportation emissions are concentrated. Transportation sources accounted for nearly half of the VOC mass at the Central site, but only 6% of the mass at the East site. Encouragingly, mass from transportation sources has declined by about 4% a year in this area; this trend is similar to the decline found throughout the United States, and is likely due to fleet turnover as older, more highly polluting cars are replaced with newer, cleaner cars. In contrast, industrial sources accounted for ten times more VOC mass at the East site than at the Central site and were responsible for most of the total VOC mass observed at the East site. Of the six industrial factors identified at the East site, four were linked to petrochemical industry production and storage. The two largest contributors to VOC mass at the East site were associated with fugitive emissions of volatile species (butanes, pentanes, hexane, and cyclohexane); together, these two factors accounted for more than 50% of the mass at the East site and less than 2% of the mass at the Central site. Natural-gas-related emissions accounted for 10% to 20% of the mass at both sites. Biogenic emissions and VOCs associated with well-mixed global background were less than 10% of the VOC mass at the Central site and less than 3% of the mass at the East site. Controllable emissions sources account for the bulk of the identified VOC mass. Efforts to reduce ozone or particulate matter precursors or exposure to toxic pollutants can now be directed to those sources most important to the Edmonton area.

McCarthy, M. C.; Brown, S. G.; Aklilu, Y.; Lyder, D. A.

2012-12-01

9

VOC EMISSION CONTROL TECHNOLOGIES FOR SHIP PAINTING FACILITIES: INDUSTRY CHARACTERIZATION  

EPA Science Inventory

The U.S. Environmental Protection Agency has the responsibility of reducing the levels of VOC emissions from the nation's stationary and mobile sources. The project was directed at assessing the levels of VOC emissions from ship painting operations with the intent of determining ...

10

Characteristics and source apportionment of VOCs measured in Shanghai, China  

NASA Astrophysics Data System (ADS)

Volatile organic compounds (VOCs) were measured from 2007 to 2010 at the center of Shanghai, China. Because VOCs are important precursors for ozone photochemical formation, detailed information of VOC sources needs to be investigated. The results show that the measured VOC concentrations in Shanghai are dominated by alkanes (43%) and aromatics (30%), following by halo-hydrocarbons (14%) and alkenes (6%). Based on the measured VOC concentrations, a receptor model (PMF; positive matrix factorization) coupled with the information related to VOC sources (the distribution of major industrial complex, meteorological conditions, etc.) is applied to identify the major VOC sources in Shanghai. The result shows that seven major VOC sources are identified by the PMF method, including (1) vehicle related source which contributes to 25% of the measured VOC concentrations, (2) solvent based industrial source to 17%, (3) fuel evaporation to 15%, (4) paint solvent usage to 15%, (5) steel related industrial production to 12%, (6) biomass/biofuel burning to 9%, and (7) coal burning to 7%. Furthermore, ozone formation potential related to VOC sources is calculated by the MIR (maximum incremental reactivity) technique. The most significant VOC source for ozone formation potential is solvent based industrial sources (27%), paint solvent usage (24%), vehicle related emissions (17%), steel related industrial productions (14%), fuel evaporations (9%), coal burning (6%), and biomass/biofuel burning (3%). The weekend effect on the VOC concentrations shows that VOC concentrations are generally higher in the weekdays than in the weekends at the sampling site, suggesting that traffic conditions and human activities have important impacts on the VOC emissions in Shanghai.

Cai, Changjie; Geng, Fuhai; Tie, Xuexi; Yu, Qiong; An, Junlin

2010-12-01

11

Source apportionment of ambient VOCS in Mumbai city  

NASA Astrophysics Data System (ADS)

Air pollution kills almost half a million Asians every year. Most of this pollution is emitted from buses, trucks, motorcycles and other forms of transport. As Asia's cities continue to expand, the rising number of vehicles has resulted in even greater pollution. Amongst the measures available to control, vehicular emission was engine modification, catalytic converters and fuel modifications. Some of these have led to emissions of some hazardous air pollutants (HAP) like volatile organic compounds (VOCs). VOC emission is an area needing attention in air quality management. This paper discusses a study on VOC concentration at major sources like traffic junction, residential area, commercial areas, industrial areas and petrol pumps in Mumbai city. CMB8 Model has been used to apportion VOCs in Mumbai city. It was observed that evaporative emissions dominate in Mumbai. In order to control VOCs in air the management strategy should thus focus on cost effective vapor recovery systems at refueling stations and in vehicles. Effective inspection and maintenance programme can reduce evaporative and exhaust VOC emissions. Modifying certain fuel parameters, like reducing benzene content in petrol will as well reduce VOC content in air. The benzene content in petrol was 3% in the year 2001 in Mumbai. Adulteration also results in high levels of VOCs in air.

Srivastava, Anjali

12

Sources of Volatile Organic Compounds (VOCs) in the UAE  

NASA Astrophysics Data System (ADS)

The gas chromatography-flame ionization detection/mass spectrometry system has been used to identify major volatile organic compounds (VOCs) sources in the UAE (latitude 24.45N; longitude 54.22E). VOCs are emitted from an extensive number of sources in urban environments including fuel production, distribution, and consumption. Transport sources contribute a substantial portion of the VOC burden to the urban atmosphere in developed regions. UAE is located at the edge of the Persian Gulf and is highly affected by emissions from petrochemical industries in neighbouring Saudi Arabia, Qatar, and Iran. VOCs emerging from these industries can be transported to the UAE with jet streams. The analysis of the collected air samples at three locations in Sharjah, UAE during the autumn and winter seasons indicates the presence of more than 100 VOC species. The concentrations of these species vary in magnitudes but the most prominent are: acetylene, ethane, propane, butane, pentane, benzene, and toluene. The possible tracers for various emission sources have also been identified such as 2-methylpentane, 1, 3-butadiene and 2, 2-dimethlybutane for vehicle exhaust, the light hydrocarbons, namely n-butane, trans-2-butene, and n-pentane for gasoline vapor, and n-nonane, n-decane, and n-undecane for diesel vapor and asphalt application processes. As various emission sources are characterized by overlapping VOC species, the ratio of possible VOC tracers are used to quantify the contribution of different sources. Our aim in this paper is to explore and discuss possible impacts of transported emissions on the local VOC emission inventory from various sources for the UAE. This work is partially supported by Office of Development and Alumni Affairs at the American University of Sharjah, U.A.E.

Abbasi, Naveed; Majeed, Tariq; Iqbal, Mazhar; Riemer, Daniel; Apel, Eric; Lootah, Nadia

13

A model for predicting VOC emission from silage  

Technology Transfer Automated Retrieval System (TEKTRAN)

Silage has been shown to be an important source of emissions of volatile organic compounds (VOCs), which are precursors to ground-level ozone. Measurements show that environmental conditions and silage properties influence emission rates, making it difficult to assess the contribution of silage to V...

14

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...

15

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

Microsoft Academic Search

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

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

2004-01-01

16

Modeling the Effects of VOC and NOx Emission Sources on Ozone Formation in Houston during the TexAQS 2000 Field Campaign  

SciTech Connect

A meteorological and chemical modeling system is used to determine the effect of ethene and propene point source emission rates on the magnitude and distribution of ozone in the vicinity of Houston. The model performance is evaluated using surface and airborne meteorological and chemical measurements made as part of the 2000 Texas Air Quality Study. A simulation that employed the reported mobile, area, biogenic, and point source emissions produced ozone mixing ratios as high as 120 ppb and distributions of nitrogen oxides that were similar to measurements at most locations, but the model underestimated ozone mixing ratios greater than 140 ppb that were located just downwind of petrochemical facilities. When the point source emission rates of ethene and propene were increased by a factor of 10, the simulated peak ozone levels were in better agreement with surface, aircraft, and lidar observations. The magnitude of the simulated ethene and olefin concentrations were in better agreement with canister samples aloft as well; however, there was still a large amount of scatter in the results. While the highest ozone mixing ratios were produced just downwind of large point source emissions of VOCs, sensitivity simulations also showed that reductions in anthropogenic emissions of NOx would be needed to reduce ozone mixing ratios over a larger area.

Jiang, Guangfeng; Fast, Jerome D.

2004-09-01

17

EVALUATION OF VOC EMISSIONS FROM HEATED ROOFING ASPHALT  

EPA Science Inventory

The report gives results of a short-term in-house project to characterize emissions from a simulated asphalt roofing kettle, performed at EPA/AEERL. ot asphalt surfacing and resurfacing has been identified as a possible significant source of volatile organic compound (VOC) emissi...

18

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

19

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...

20

Measurements of biogenic VOC emissions: sampling, analysis and calibration  

NASA Astrophysics Data System (ADS)

We describe an experimental system and techniques for sampling and analyzing biogenic emissions of volatile organic compounds (VOC). The system uses a Teflon chamber to enclose a single branch of a tree. Temperature, photosynthetic active radiation (PAR), relative humidity and carbon dioxide concentration are continuously monitored with a time resolution of five minutes. VOCs are sampled on tubes containing solid adsorbents (Tenax TA and Carbotrap) with a time resolution of 1 h. Composition and concentration of VOC emissions are measured with a gas chromatographic system equipped with a flame ionization detector (FID) for quantitative and a mass spectrometer (MS) for qualitative analysis. To calibrate the system, a diffusion source was built to produce standard mixtures of up to 36 different compounds with mixing ratios at low concentrations and high accuracy. The diffusion rates were monitored over 17 months and showed variations between 0.2 and 7.6% for monoterpenes (expect for ?-phellandrene, ?-terpinene and ?-terpinene) and between 10.6 and 22.6% for sesquiterpenes. FID response factors calculated from calibration measurements were corrected using correction factors based on the effective carbon number concept. The individual response factors of 23 compounds were combined to a mean response factor (RF m) with a value of 23,100 ?V s ng -1 and a standard deviation of 9%. The system described here was used to measure VOC emission rates of Scots pine ( Pinus sylvestris) in 1998 and 1999.

Komenda, M.; Parusel, E.; Wedel, A.; Koppmann, R.

21

Novel aqueous foams for suppressing VOC emission.  

PubMed

Reducing volatile organic compound (VOC) emissions from crude oil/gasoline distribution and storage facilities is important in controlling environmental pollution and enhancing workplace safety. Stable aqueous foam formulations are developed to provide a mass transfer barrier to the emission of VOCs during loading of gasoline. Experiments are carried out in a bench-scale foam cell using liquid hexane as oil. The foam columns of 32 cm in height were able to suppress the plateau concentration of hexane vapors in the effluent by 87% under experimental conditions tested. Vapor suppression increased with foam height but was almost insensitive to liquid viscosity. These experiments are then upscaled from bench-scale to a vessel having an exposed surface area of roughly 2 orders of magnitude higher. Gasoline is used as oil in the upscaled experiments, and the concentrations of volatile hydrocarbons in the effluent are measured during oil loading. A 40-cm-thick foam column is found to reduce the emissions by 96% for foams prepared with deionized water and by 93.8% for foams prepared with 3.5 wt % NaCl brine for 10 h of oil loading. PMID:15180071

Gautam, Pankaj S; Mohanty, Kishore K

2004-05-01

22

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

EPA Science Inventory

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

23

Estimation of VOC emission rates from FTIR measurements and whole-air canister data  

Microsoft Academic Search

Methods of estimating VOC emission rates from a point source are being field tested by the University of Kansas, in cooperation with Region VII of the U.S. EPA and Kansas State University. The methods use path-integrated VOC concentrations, meteorological data, and a form of the Gaussian dispersion equation. VOC concentrations were derived both from a whole-air canister sampling method, with

Ray E. Carter; Glen A. Marotz; Michael F. Davis; Jody L. Hudson; Charles T. Chaffin; Tim L. Marshall; Robert M. Hammaker; William G. Fateley

1995-01-01

24

VOC signatures from North American oil and gas sources (Invited)  

NASA Astrophysics Data System (ADS)

Between 2008 and 2013 UC Irvine has used its whole air sampling (WAS) technique to investigate VOC source signatures from a range of oil and gas sources in North America, including five separate field campaigns at the Alberta oil sands (1 airborne, 4 ground-based); the 2010 Deepwater Horizon oil spill (airborne and ship-based); the 2012 airborne Deep Convective Clouds and Chemistry Project (DC3) mission over oil and gas wells in Colorado, Texas and Oklahoma; and the 2013 ground-based Barnett Shale Campaign in Texas. Each campaign has characterized more than 80 individual C1-C10 VOCs including alkanes, alkenes and aromatics. For example, oil sands are an extra-heavy, unconventional crude oil that is blended with diluent in order to flow, and upgraded into synthetic crude oil. The VOC signature at the oil sands mining and upgrading facilities is alkane-rich, and the fuel gas associated with these operations has an i-butane/n-butane ratio similar to that of liquefied petroleum gas (LPG). In addition to light alkanes, enhanced levels of benzene were observed over US oil and natural gas wells during DC3, likely because of its use in hydrofracking fluid. A series of VOC emission ratios from North American petrochemical sources will be presented and compared, including oil sands, conventional oil and hydrofracking operations.

Simpson, I. J.; Marrero, J.; Blake, N. J.; Barletta, B.; Hartt, G.; Meinardi, S.; Schroeder, J.; Apel, E. C.; Hornbrook, R. S.; Blake, D. R.

2013-12-01

25

A review of the emission of VOCs from polymeric materials used in buildings  

Microsoft Academic Search

Building and furnishing materials and consumers products are important sources of formaldehyde and other volatile organic compounds (VOCs) in the indoor environment. The emission from materials is usually continuous and may last for many years in a building. The available evidence indicates that VOCs can cause adverse health effects to the building occupants and may contribute to symptoms of ‘Sick

Chuck Yu; Derrick Crump

1998-01-01

26

Odorous VOC emission following land application of swine manure slurry  

NASA Astrophysics Data System (ADS)

Swine manure is often applied to crop land as a fertilizer source. Odor emissions from land-applied swine manure may pose a nuisance to downwind populations if manure is not applied with sufficient forethought. A research project was conducted to assess the time decay of odorous volatile organic compound (VOC) emissions following land application of swine manure. Three land application methods were compared: surface application, incorporation 24 h after surface application, and injection. Emission rates were measured in field plots using a small wind tunnel and sorbent tubes. VOCs including eight volatile fatty acids, five aromatics, and two sulfur-containing compounds were quantified by gas chromatography-mass spectrometry. In most cases, a first order exponential decay model adequately described the flux versus time relationship for the 24 h period following land application, but the model sometimes overestimated flux in the 6-24 h range. The same model but with the time term squared adequately predicted flux over the entire 24 h period. Three compounds (4-methylphenol, skatole, and 4-ethylphenol) accounted for 93 percent of the summed odor activity value. First order decay constants (k) for these three compounds ranged from 0.157 to 0.996 h-1. When compared to surface application, injection of swine manure resulted in 80-95 percent lower flux for the most odorous aromatic compounds. These results show that VOC flux decreases rapidly following land application of swine manure, declining below levels of detection and near background levels after 4 to 8 h.

Parker, David B.; Gilley, John; Woodbury, Bryan; Kim, Ki-Hyun; Galvin, Geordie; Bartelt-Hunt, Shannon L.; Li, Xu; Snow, Daniel D.

2013-02-01

27

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

28

Characterization and measurement of VOC emissions from silage  

Technology Transfer Automated Retrieval System (TEKTRAN)

There is growing concern in the U.S. regarding the emission of volatile organic compounds (VOCs) from farms and their contribution to smog formation near ozone non-attainment areas. The few studies that have measured VOC emissions have identified mixed feed and the exposed silage face as major farm ...

29

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

30

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...

31

Biofiltration: An Innovative Air Pollution Control Technology For VOC Emissions  

Microsoft Academic Search

Biofiltration is a relatively recent air pollution control (APC) technology in which off-gases containing biodegradable volatile organic compounds (VOC) or inorganic air toxics are vented through a biologically active material. This technology has been successfully applied in Germany and The Netherlands in many full-scale applications to control odors, VOC and air toxic emissions from a wide range of industrial and

Gero Leson; Arthur M. Winer

1991-01-01

32

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...

33

Estimation of VOC emission factors from flux measurements using a receptor model and footprint analysis  

NASA Astrophysics Data System (ADS)

Fluxes of 18 volatile organic compounds (VOCs) collected during May to July 2008 from a tower platform 60 m above the surface in an urban Houston residential area were analyzed using receptor-oriented statistical models and an analytical flux-footprint model to resolve daytime source specific emissions rates. The Multilinear Engine version 2 (ME-2) was used to determine that five sources were responsible for the measured flux at the tower: (i) vehicle exhaust, (ii) a foam plastics industrial source with significant pentane emissions, (iii) consumer and commercial solvent use emissions, (iv) a biogenic emissions source dominated by isoprene, and, (v) evaporative fuel emissions. The estimated median daytime (0700-1900 CST) hourly emission rate from the foam plastics industry was 15.7 ± 3.1 kg h-1, somewhat higher than its permitted hourly emission rates. The median daytime vehicle exhaust VOC emission rate of 14.5 ± 2 g h-1 vehicle-1, was slightly higher than our estimation using the Motor Vehicle Emission Simulator (MOVES) with a county-representative vehicle fleet of year 2008 (11.6 ± 0.2 g h-1 vehicle-1). The median daytime evaporative fuel VOCs emission rate from parked vehicles was 2.3 ± 1.0 g h-1 vehicle-1, which is higher than MOVES estimations and could not be explained by the age of the vehicle fleet, indicating either locally higher evaporative emission sources in the footprint or an underestimation of evaporative emissions by MOVES, or both.

Kota, Sri Harsha; Park, Changhyoun; Hale, Martin C.; Werner, Nicholas D.; Schade, Gunnar W.; Ying, Qi

2014-01-01

34

Volatile organic compounds (VOCs) in air from Nisyros Island (Dodecanese Archipelago, Greece): Natural versus anthropogenic sources.  

PubMed

This study presents the chemical composition of VOCs in air and gas discharges collected at Nisyros Island (Dodecanese Archipelago, Greece). The main goals are i) to discriminate between natural and anthropogenic VOC sources and ii) to evaluate their impact on local air quality. Up to 63 different VOCs were recognized and quantitatively determined in 6 fumaroles and 19 air samples collected in the Lakki caldera, where fumarolic emissions are located, and the outer ring of the island, including the Mandraki village and the main harbor. Air samples from the crater area show significant concentrations of alkanes, alkenes, cyclic, aromatics, and S- and O-bearing heterocycles directly deriving from the hydrothermal system, as well as secondary O-bearing compounds from oxidation of primary VOCs. At Mandraki village, C6H6/?(methylated aromatics) and ?(linear)/?(branched) alkanes ratios <1 allow to distinguish an anthropogenic source related to emissions from outlet pipes of touristic and private boats and buses. PMID:23747819

Tassi, F; Capecchiacci, F; Giannini, L; Vougioukalakis, G E; Vaselli, O

2013-09-01

35

VOC Source and Inflow Characterization during the Deep Convective Cloud and Chemistry (DC3) experiment  

NASA Astrophysics Data System (ADS)

More than 50 volatile organic compounds (VOCs) were measured during the Deep Convective Clouds and Chemistry Project (DC3) field campaign, which was based out of Salina, KS May 10 - June 30, 2012. DC3 investigated the impact of deep, mid-latitude continental convective clouds on upper tropospheric composition and chemistry. The UCI Whole Air Sampler (WAS) measured VOCs on board the NASA DC-8 aircraft and the NCAR Trace Organic Gas Analyzer (TOGA) measured VOCs on board the NSF GV. Coordinated flights between the two aircraft produced a rich dataset with which to characterize the inflow and outflow of convective events. While probing storm inflow, numerous natural and anthropogenic sources were encountered, including oil and gas wells in Colorado, Texas, and Oklahoma, biomass burning, biogenic VOC emissions, and other anthropogenic sources (urban, feedlots, etc). The significant and widespread influence of oil and gas activities dominated VOC alkane distributions during DC3, in both inflow and outflow, effectively illustrating the connection between emission and fast vertical transport of VOCs into the free troposphere. We present a mass balance analysis of a flight over TX and OK, which allowed us to estimate oil and gas emissions in that region. The results from this analysis will be compared to previous work in the same area, as well as to emissions from other oil and gas regions and to model simulations from the Community Atmosphere Model with Chemistry (CAM-chem).

Blake, N. J.; Hartt, G.; Barletta, B.; Simpson, I. J.; Schroeder, J.; Hung, Y.; Marrero, J.; Gartner, A.; Hirsch, C.; Meinardi, S.; Blake, D. R.; Zhang, Y.; Apel, E. C.; Hornbrook, R. S.; Campos, T. L.; Emmons, L. K.

2013-12-01

36

Effects of NO x and VOCs from five emission sources on summer surface O3 over the Beijing-Tianjin-Hebei region  

NASA Astrophysics Data System (ADS)

The impacts of emissions from industry, power plant, transportation, residential, and biogenic sources on daily maximum surface ozone (O3DM) over the Beijing-Tianjin-Hebei (BTH) region in North China in the summer of 2007 were examined in a modeling study. The modeling system consisted of the Weather Research and Forecasting (WRF) model and the photochemical dispersion model, CAMx. The factor separation technique (FST) was used to quantify the effect of individual emission source types and the synergistic interactions among two or more types. Additionally, the effectiveness of emission reduction scenarios was explored. The industry, power plant, and transportation emission source types were found to be the most important in terms of their individual effects on O3DM. The key contributor to high surface O3 was power plant emissions, with a peak individual effect of 40 ppbv in the southwestern BTH area. The individual effect from the biogenic emission category was quite low. The synergistic effects from the combinations of each pair of anthropogenic emission types suppressed O3 formation, while the synergistic effects for combinations of three were favorable for O3 formation when the industrial and power plant emission source types coexisted. The quadruple synergistic effects were positive only with the combination of power plant, transportation, residential, and biogenic sources, while the quintuple synergistic effect showed only minor impacts on O3DM concentrations. A 30% reduction in industrial and transportation sources produced the most effective impacts on O3 concentrations, with a maximum decrease of 20 ppbv. These results suggested that the synergistic impacts among emission source types should be considered when formulating emission control strategies for O3 reduction.

Qu, Yu; An, Junling; Li, Jian; Chen, Yong; Li, Ying; Liu, Xingang; Hu, Min

2014-07-01

37

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...

38

Speciated VOC emission inventory and spatial patterns of ozone formation potential in the Pearl River Delta, China.  

PubMed

The Pearl River Delta region (PRD) of China has long suffered from severe ground-level ozone pollution. Knowledge of the sources of volatile organic compounds (VOCs) is essential for ozone chemistry. In this work, a speciated VOC emission inventory was established on the basis of updated emissions and local VOC source profiles. The top 10 species, in terms of ozone formation potentials (OFPs), consisted of isoprene, mp-xylene, toluene, ethylene, propene, o-xylene, 1,2,4-trimethylbenzene, 2-methyl-2-butene, 1-butene, and alpha-pinene. These species contributed only 35.9% to VOCs emissions but accounted for 64.1% of the OFP in the region. The spatial patterns of the VOC source inventory agreed well with city-based source apportionment results, especially for vehicle emissions and industry plus VOC product-related emissions. Mapping of the OFPs and measured ozone concentrations indicated that the formation of higher ozone in the south and southeast of the PRD region differed from that in the Conghua area, a remote area in the north of the PRD. We recommend that the priorities for the control of VOC sources include motorcycles, gasoline vehicles, and solvent use because of their larger OFP contributions. PMID:20028055

Zheng, Junyu; Shao, Min; Che, Wenwei; Zhang, Lijun; Zhong, Liuju; Zhang, Yuanhang; Streets, David

2009-11-15

39

Assessing and evaluating urban VOC emissions in mid-latitude megacities from intensive observations in Paris and Los Angeles  

NASA Astrophysics Data System (ADS)

Volatile Organic Compounds (VOC) affect urban air quality and regional climate change by contributing to ozone formation and the build-up of Secondary Organic Aerosols (SOA). Quantification of VOC emissions is a first critical step to predict VOC environmental impacts and to design effective abatement strategies. Indeed, the quality of ozone and SOA forecasts strongly depends on an accurate knowledge of the primary VOC emissions. However, commonly used bottom-up approaches are highly uncertain due to source multiplicity (combustion processes, storage and distribution of fossil fuels, solvent use, etc.) because of numerous controlling factors (driving conditions, fuel type, temperature, radiation, etc.), and their great variability in time and space. Field observations of VOC and other trace gases can provide valuable top-down constraints to evaluate VOC emission inventories at urban scales. In addition, the implementation of emission reduction measures raises the question of the increasing importance of VOC sources other than traffic. Here, we will evaluate VOC emissions of two mid-latitude megacities in the Northern Hemisphere: the Greater Paris area (Europe) and Los Angeles (USA). In 2009 and 2010, three intensive field campaigns took place in Paris and Los Angeles in the framework of the MEGAPOLI (EU FP7) and CalNex-2010 projects, respectively. Very detailed measurements of aerosol composition and properties, and their gaseous VOC precursors were carried out at ground-based sites (urban center and suburban) and on various mobile platforms. This contribution uses a comprehensive suite of VOC measurements collected by GC-MS/FID techniques at ground-based sites in both cities by a source-receptor methodology. First, emission ratios were estimated from the observations (uncertainty of ± 20%) and compared regarding regional characteristics and European vs. Californian control policies. Then, determined emission ratios were used to assess the accuracy of up-to-date emission inventories. While emission ratios agree within the uncertainties for many VOCs, remarkable differences are observed for aromatic VOCs (C7-C9) depending on the season. Moreover, the evaluation of emission inventories shows large discrepancies for VOCs for which traffic is not the dominant source. Commonalities and/or differences are also discussed in term of implication for urban atmospheric chemistry (ozone and SOA formation potential) in both megacities.

Borbon, A.; Gilman, J. B.; Kuster, W. C.; McKeen, S. A.; Holloway, J. S.; Gros, V.; Gaimoz, C.; Beekmann, M.; De Gouw, J. A.

2011-12-01

40

A refined 2010-based VOC emission inventory and its improvement on modeling regional ozone in the Pearl River Delta Region, China.  

PubMed

Accurate and gridded VOC emission inventories are important for improving regional air quality model performance. In this study, a four-level VOC emission source categorization system was proposed. A 2010-based gridded Pearl River Delta (PRD) regional VOC emission inventory was developed with more comprehensive source coverage, latest emission factors, and updated activity data. The total anthropogenic VOC emission was estimated to be about 117.4×10(4)t, in which on-road mobile source shared the largest contribution, followed by industrial solvent use and industrial processes sources. Among the industrial solvent use source, furniture manufacturing and shoemaking were major VOC emission contributors. The spatial surrogates of VOC emission were updated for major VOC sources such as industrial sectors and gas stations. Subsector-based temporal characteristics were investigated and their temporal variations were characterized. The impacts of updated VOC emission estimates and spatial surrogates were evaluated by modeling O3 concentration in the PRD region in the July and October of 2010, respectively. The results indicated that both updated emission estimates and spatial allocations can effectively reduce model bias on O3 simulation. Further efforts should be made on the refinement of source classification, comprehensive collection of activity data, and spatial-temporal surrogates in order to reduce uncertainty in emission inventory and improve model performance. PMID:25687669

Yin, Shasha; Zheng, Junyu; Lu, Qing; Yuan, Zibing; Huang, Zhijiong; Zhong, Liuju; Lin, Hui

2015-05-01

41

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...

42

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

Code of Federal Regulations, 2014 CFR

...Volatile Organic Compound (VOC) emissions from bulk gasoline terminals. 60.502 ...Standards of Performance for Bulk Gasoline Terminals § 60.502 ...Organic Compound (VOC) emissions from bulk gasoline terminals. On and...

2014-07-01

43

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

Code of Federal Regulations, 2012 CFR

...Volatile Organic Compound (VOC) emissions from bulk gasoline terminals. 60.502 ...Standards of Performance for Bulk Gasoline Terminals § 60.502 ...Organic Compound (VOC) emissions from bulk gasoline terminals. On and...

2012-07-01

44

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

Code of Federal Regulations, 2013 CFR

...Volatile Organic Compound (VOC) emissions from bulk gasoline terminals. 60.502 ...Standards of Performance for Bulk Gasoline Terminals § 60.502 ...Organic Compound (VOC) emissions from bulk gasoline terminals. On and...

2013-07-01

45

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

Code of Federal Regulations, 2011 CFR

...Volatile Organic Compound (VOC) emissions from bulk gasoline terminals. 60.502 ...Standards of Performance for Bulk Gasoline Terminals § 60.502 ...Organic Compound (VOC) emissions from bulk gasoline terminals. On and...

2011-07-01

46

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

Code of Federal Regulations, 2010 CFR

...Volatile Organic Compound (VOC) emissions from bulk gasoline terminals. 60.502 ...Standards of Performance for Bulk Gasoline Terminals § 60.502 ...Organic Compound (VOC) emissions from bulk gasoline terminals. On and...

2010-07-01

47

VOC emission into the atmosphere by trees and leaf litter in Polish forests  

NASA Astrophysics Data System (ADS)

It is generally recognized at present that the vegetation of continents is the principal source of reactive volatile organic compounds (VOC) of the atmosphere. The upper limit of the evaluation of global phytogenic VOC is 1100-1500 Tg/yr (Isidorov, 1990; Guenther et al., 1995). Although these global evaluations showing the place of phytogenic emission among of other VOC sources are important, evaluations for individual countries are also very important. This poster represents the results of the estimation of VOC emission from Polish forests. Calculations took into account the composition and age of forests. According to our estimation, the total VOC emission by the arboreal vegetation differs from 190 to 750 kt/yr, depending of weather conditions in different years. There are only few studies conducted on decaying plant material as a source of atmospheric VOCs, but still they are able to give evidence of the importance of this source. For Polish forests, the litter mass is estimated to be (16-19)?106 t/yr. These organic materials undergo decomposition by mesofauna and microorganisms. In these processes volatile organic compounds (VOC) stored in the litter and secondary metabolites of litter-destroying fungi are emitted into the atmosphere. The scale of the phenomenon makes leaf litter an important VOC source in the atmosphere. The filling of numerous gaps in researches of VOC emissions from decomposing leaf litter demands carrying out of long term field experiments in various climatic conditions. In this communication we report also the results of 3.5-year experiment on qualitative and quantitative GC-MS investigations of VOC emitted into the gas phase from leaves litter of some species of deciduous and coniferous trees of Polish forests. Apart from terpenes and their oxygenated derivatives, which are usual in plant tissues, leaf litter intensively emits vast amounts of lower alcohols and carbonyl compounds. We suppose that these volatile substances are products of vital activity of fungi which decompose leaf litter. Verification of the hypothesis was carried out in the frames of a long-term experiment on decomposition of Scots pine and common spruce litter. The experiment was conducted in natural conditions by placing litter bags on undisturbed topsoil in a forest area where pine and spruce trees prevailed. Part of the needles placed were taken out of the litter bags on the 30th, 282nd, 490th, 630th and 920th day of the experiment for subsequent isolation of fungi which colonize the litter (overall there were identified 98 species which belong to 48 genera of fungi). The experiment revealed that species composition of the fungi colonizing pine and spruce litter varies considerably. At the early stages of decomposition, dematiceous hypnomycetes, which belongs to Cladosporum, Alternaria genera as well as Hormonem genus, capable of utilizing pectin, were dominant species. At the later stages they were substituted with phycomycetes (Mucor sp.), ascomycetes (Penicillium sp.) and basidiomycetes (Trichderma sp.), the most significant group of "secondary saprophytes" able to carry out biodegradation of polysaccharides and lignin. In volatile emissions of all the 15 species of fungi there were identified 80 VOCs of different classes: terpene hydrocarbons and their oxygenated derivatives, C6-C14 aliphatic and C6-C10 aromatic hydrocarbons, C1-C8 alcohols, C2-C9 carbonyls, esters, furans, and halocarbons. VOC composition was specific for each fungi species and depended on the litter of a particular tree species from which it had been isolated. For instance, the emission rate of terpenes, alcohols and carbonyl compounds by Trichoderma polysporum isolated from pine and spruce litter was 3-5 times different. Differences in composition of VOCs emitted into the gas phase by "primary" and "secondary" fungi species which colonize pine and spruce litter are also discussed. This work was supported by Grant MNiSW N305 067 32/2411.

Isidorov, V.; Smolewska, M.; Tyszkiewicz, Z.

2009-04-01

48

Primary VOC emissions from Commercial Aircraft Jet Engines  

NASA Astrophysics Data System (ADS)

Air traffic is growing continuously [1]. The increasing number of airplanes leads to an increase of aviation emissions giving rise to environmental concerns globally by high altitude emissions and, locally on air quality at the ground level [2]. The overall impact of aviation emissions on the environment is likely to increase when the growing air transportation trend [2] is considered. The Aviation Particle Regulatory Instrumentation Demonstration Experiment (APRIDE)-5 campaign took place at Zurich Airport in 2013. In this campaign, aircraft exhaust is sampled during engine acceptance tests after engine overhaul at the facilities of SR Technics. Direct sampling from the engine core is made possible due to the unique fixed installation of a retractable sampling probe and the use of a standardized sampling system designed for the new particulate matter regulation in development for aircraft engines. Many of the gas-phase aircraft emissions, e.g. CO2, NOX, CO, SO2, hydrocarbons, and volatile organic compounds (VOC) were detected by the instruments in use. This study, part of the APRIDE-5 campaign, focuses on the primary VOC emissions in order to produce emission factors of VOC species for varying engine operating conditions which are the surrogates for the flight cycles. Previously, aircraft plumes were sampled in order to quantify VOCs by a proton transfer reaction quadrupole mass spectrometer (PTR-MS) [3]. This earlier study provided a preliminary knowledge on the emission of species such as methanol, acetaldehyde, acetone, benzene and toluene by varying engine thrust levels. The new setup was (i) designed to sample from the diluted engine exhaust and the new tool and (ii) used a high resolution time of flight PTR-MS with higher accuracy for many new species, therefore providing a more detailed and accurate inventory. We will present the emission factors for species that were quantified previously, as well as for many additional VOCs detected during the campaign. References 1."Annual Review 2013", International Air Transport Association (IATA) 2014, Page 8, available on: http://www.iata.org/about/Documents/iata-annual-review-2013-en.pdf. 2."Summary for Policymakers: IPCC Special Report Aviation and the Global Atmosphere", 1999, pp. 5-10. 3."Hydrocarbon emissions from in-use commercial aircraft during airport operations", Herndon S.C., Rogers T., Dunlea E.J., Jayne J.T., Miake-Lye R., Knighton B., Environ Sci. Technol. 2006 Jul 15;40(14):4406-13.

Kilic, Dogushan; Huang, Rujin; Slowik, Jay; Brem, Benjamin; Durdina, Lukas; Rindlisbacher, Theo; Baltensperger, Urs; Prevot, Andre

2014-05-01

49

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

E-print Network

for regional VOC emissions modeling Trevor Keenan,1 U¨ lo Niinemets,2 Santi Sabate,1,3 Carlos Gracia,1 18 November 2009. [1] VOC emissions from terrestrial ecosystems provide one of the principal controls processes have strong seasonal cycles. Although similar seasonal cycles in VOC emissions from terrestrial

Gracia, Carlos

50

AN ALTERNATIVE METHOD FOR ESTIMATING BIOGENIC VOC EMISSIONS IN EPA REGION I  

EPA Science Inventory

Regional estimates of biogenic volatile organic compound (VOC) emissions are needed for computer simulations of photochemical smog. ince forests and agricultural crops are the primary emitters of biogenic voc, it is important to develop reliable estimates of their areal coverage ...

51

The characteristics, seasonal variation and source apportionment of VOCs at Gongga Mountain, China  

NASA Astrophysics Data System (ADS)

The mixing ratio, composition and variability of volatile organic compounds (VOCs) were measured from 2008 through 2011 at Gongga Mountain Forest Ecosystem Research Station (102°00?E, 29°33?N, elevation 1640 m), a remote station in southwest China. Weekly samples were collected in the Gongga Mountain area and were analyzed using a three-stage preconcentration method coupled with GC-MS. An advance receptor model positive matrix factorization (PMF) was applied to identify and apportion the sources of VOCs. The results show that the measured VOC mixing ratio at Gongga Mountain is dominated by aromatics (35.7%) and alkanes (30.8%), followed by halocarbons (21.6%) and alkenes (11.9%). The general trend of seasonal variation shows higher mixing ratios in spring and lower mixing ratios in autumn. The effect of alkanes and aromatics on the seasonal variation of total volatile organic compounds (TVOCs) is significant. Five sources were resolved by the PMF model: (1) gasoline-related emission (the combination of gasoline exhaust and gas vapor), which contributes 35.1% of the measured VOC mixing ratios; (2) solvent use, contributing 21.8%; (3) fuel combustion, contributing 29.1%; (4) biogenic emission, contributing 5.2%; and (5) industrial, commercial and domestic sources, contributing 8.7%. The effect on this area of the long-range transport of air pollutants from highly polluted areas is significant.

Zhang, Junke; Sun, Yang; Wu, Fangkun; Sun, Jie; Wang, Yuesi

2014-05-01

52

Estimates of ozone response to various combinations of NO(x) and VOC emission reductions in the eastern United States  

NASA Technical Reports Server (NTRS)

There is increasing recognition that controls on NO(x) emissions may be necessary, in addition to existing and future Volatile Organic Compounds (VOC) controls, for the abatement of ozone (O3) over portions of the United States. This study compares various combinations of anthropogenic NO(x) and VOC emission reductions through a series of model simulations. A total of 6 simulations were performed with the Regional Oxidant Model (ROM) for a 9-day period in July 1988. Each simulation reduced anthropogenic NO(x) and VOC emissions across-the-board by different amounts. Maximum O3 concentrations for the period were compared between the simulations. Comparison of the simulations suggests that: (1) NO(x) controls may be more effective than VOC controls in reducing peak O3 over most of the eastern United States; (2) VOC controls are most effective in urban areas having large sources of emissions; (3) NO(x) controls may increase O3 near large point sources; and (4) the benefit gained from increasing the amount of VOC controls may lessen as the amount of NO(x) control is increased. This paper has been reviewed in accordance with the U.S. Environmental Protection Agency's peer and administrative review policies and approved for presentation and publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

Roselle, Shawn J.; Schere, Kenneth L.; Chu, Shao-Hang

1994-01-01

53

Evaluation of VOC emission measurement methods for paint spray booths.  

PubMed

Interest in regulations to control solvent emissions from automotive painting systems is increasing, especially in ozone nonattainment areas. Therefore, an accurate measurement method for VOC emissions from paint spray booths used in the automotive industry is needed to ascertain the efficiency of the spray booth capture and the total emissions. This paper presents the results of a laboratory study evaluating potential VOC sampling and analytical methods used in estimating paint spray booth emissions, and discusses these results relative to other published data. Eight test methods were selected for evaluation. The accuracy of each sampling and analytical method was determined using test atmospheres of known concentration and composition that closely matched the actual exhaust air from paint spray booths. The solvent mixture to generate the test atmospheres contained a large proportion of polar, oxygenated hydrocarbons such as ketones and alcohols. A series of identical tests was performed for each sampling/analytical method with each test atmosphere to assess the precision of the methods. The study identified significant differences among the test methods in terms of accuracy, precision, cost, and complexity. PMID:15658160

Eklund, B M; Nelson, T P

1995-03-01

54

[Study on the quantitative estimation method for VOCs emission from petrochemical storage tanks based on tanks 4.0.9d model].  

PubMed

VOCs emission from petrochemical storage tanks is one of the important emission sources in the petrochemical industry. In order to find out the VOCs emission amount of petrochemical storage tanks, Tanks 4.0.9d model is utilized to calculate the VOCs emission from different kinds of storage tanks. VOCs emissions from a horizontal tank, a vertical fixed roof tank, an internal floating roof tank and an external floating roof tank were calculated as an example. The consideration of the site meteorological information, the sealing information, the tank content information and unit conversion by using Tanks 4.0.9d model in China was also discussed. Tanks 4.0.9d model can be used to estimate VOCs emissions from petrochemical storage tanks in China as a simple and highly accurate method. PMID:24640914

Li, Jing; Wang, Min-Yan; Zhang, Jian; He, Wan-Qing; Nie, Lei; Shao, Xia

2013-12-01

55

Characteristics and source apportionment of VOCs measured in an industrial area of Nanjing, Yangtze River Delta, China  

NASA Astrophysics Data System (ADS)

Based on the data of volatile organic compounds (VOCs) collected continuously in the Nanjing industrial area, the VOCs temporal variability, photochemical reactivity, differences in tracer ratios, and source apportionment by principal component analysis/absolute principal component scores (PCA/APCS) were analyzed. The results showed that the total VOC concentration was 43.5 ppbv, which was 45.1% alkanes, 25.3% alkenes, 7.3% alkynes and 22.3% aromatics. There was an obvious seasonal variation in the of VOCs, with a maximum in summer and minimum in winter, as well as in the VOC components, with alkanes and alkynes highest in winter, alkenes highest in summer, and aromatics highest in spring. The VOCs exhibited significant diurnal variations, i.e. high at night and low during the day. The concentrations of nighttime VOCs were highest to lowest as follows: summer > autumn > spring > winter. By contrast, the concentrations of daytime VOCs were highest to lowest as follows: winter > summer > spring > autumn. The diurnal variation of the VOCs was the largest in autumn and the smallest in winter. The largest diurnal variation of alkanes and alkenes occurred in autumn, whereas the largest diurnal variation of aromatics and alkynes occurred in spring. Using the propylene-equivalent method, alkenes had the highest concentration, followed by aromatics and alkanes. The ratios of T/B, E/B and X/B were 1.2, 1.0 and 0.8, respectively, possibly due to the aging air mass. Based on the specific pollutant ratio method, the observation site was greatly affected by the surrounding industrial areas. The source analysis of the VOCs in the PCA/APCS mode showed that the sources consisted of industrial production sources, automobile emission sources, combustion sources, industrial production volatilization sources, solvent use sources and biogenic emission sources; in addition, there were seasonal variations. Overall, the sources related to industrial production activities accounted for 45-63% of the VOCs, followed by automobile emission sources, which accounted for 34-50%.

An, Junlin; Zhu, Bin; Wang, Honglei; Li, Yongyu; Lin, Xu; Yang, Hui

2014-11-01

56

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

NASA Astrophysics Data System (ADS)

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 250 d. 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 (butyl acetate, N-methylpyrrolidone), sealant (hexane, dimethyloctanols), and waterborne wall paint on gypsum board (1,2-propandiol, Texanol). Ten different climate conditions were tested: four different air velocities from ca. 1 cm s -1 to ca. 9 cm s -1, three different temperatures (23, 35, and 60°C), two different relative humidities (0% and 50% RH), and pure nitrogen instead of clean air supply. Additionally, two sample specimen and two different batches were compared for repeatability and homogeneity. The VOCs were sampled on Tenax TA and determined by thermal desorption and gas chromatography (FID). Quantification was carried out by individual calibration of each VOC of concern. Concentration/time profiles of the selected VOCs (i.e. their concentration decay curves over time) in a standard room were used for comparison. Primary source emissions were not affected by the air velocity after a few days to any great extent. Both the temperature and relative humidity affected the emission rates, but depended strongly on the type of BP and type of VOC. Secondary (oxidative) source emissions were only observed for the PVC and for dimethyloctanols from the sealant. The time to reach a given concentration (emission rate) appears to be a good approach for future interlaboratory comparisons of BP's VOC emissions.

Wolkoff, Peder

57

Photochemical grid model implementation and application of VOC, NOx, and O3 source apportionment  

NASA Astrophysics Data System (ADS)

For the purposes of developing optimal emissions control strategies, efficient approaches are needed to identify the major sources or groups of sources that contribute to elevated ozone (O3) concentrations. Source-based apportionment techniques implemented in photochemical grid models track sources through the physical and chemical processes important to the formation and transport of air pollutants. Photochemical model source apportionment has been used to track source impacts of specific sources, groups of sources (sectors), sources in specific geographic areas, and stratospheric and lateral boundary inflow on O3. The implementation and application of a source apportionment technique for O3 and its precursors, nitrogen oxides (NOx) and volatile organic compounds (VOCs), for the Community Multiscale Air Quality (CMAQ) model are described here. The Integrated Source Apportionment Method (ISAM) O3 approach is a hybrid of source apportionment and source sensitivity in that O3 production is attributed to precursor sources based on O3 formation regime (e.g., for a NOx-sensitive regime, O3 is apportioned to participating NOx emissions). This implementation is illustrated by tracking multiple emissions source sectors and lateral boundary inflow. NOx, VOC, and O3 attribution to tracked sectors in the application are consistent with spatial and temporal patterns of precursor emissions. The O3 ISAM implementation is further evaluated through comparisons of apportioned ambient concentrations and deposition amounts with those derived from brute force zero-out scenarios, with correlation coefficients ranging between 0.58 and 0.99 depending on specific combination of target species and tracked precursor emissions. Low correlation coefficients occur for chemical regimes that have strong nonlinearity in O3 sensitivity, which demonstrates different functionalities between source apportionment and zero-out approaches, where appropriate use depends on whether source attribution or source sensitivity is desired.

Kwok, R. H. F.; Baker, K. R.; Napelenok, S. L.; Tonnesen, G. S.

2015-01-01

58

Methodologies for evaluating sources of volatile organic chemicals (VOC) in homes  

NASA Astrophysics Data System (ADS)

After a classification of sources of VOC into four groups (continuous and intermittent, regular and irregular) and of air sampling procedures according to the duration of sampling and the sampling mode (active and passive), three representative case-studies are presented to discuss how an appropriate combination of source-type and sampling procedure can lead to a source evaluation. One of the case-studies revealed that the results of emission rate measurements carried out in the laboratory can give erroneous predictions of the substance concentrations to be expected in practice. It is concluded that evaluating sources of VOC under general toxicological and public health aspects calls for an intensive statistical treatment of measurements and questionnaires obtained from a very large number of homes.

Seifert, B.; Ullrich, D.

59

Influence of tree provenance on biogenic VOC emissions of Scots pine (Pinus sylvestris) stumps  

NASA Astrophysics Data System (ADS)

Resin-storing plant species such as conifer trees can release substantial amounts of volatile organic compounds (VOCs) into the atmosphere under stress circumstances that cause resin flow. Wounding can be induced by animals, pathogens, wind or direct mechanical damage e.g. during harvesting. In atmospheric modelling of biogenic VOCs, actively growing vegetation has been mostly considered as the source of emissions. Root systems and stumps of resin-storing conifer trees could constitute a significant store of resin after tree cutting. Therefore, we assessed the VOC emission rates from the cut surface of Scots pine stumps and estimated the average emission rates for an area with a density of 2000 stumps per ha. The experiment was conducted with trees of one Estonian and three Finnish Scots pine provenances covering a 1200 km gradient at a common garden established in central Finland in 1991. VOC emissions were dominated by monoterpenes and less than 0.1% of the total emission was sesquiterpenes. ?-Pinene (7-92% of the total emissions) and 3-carene (0-76% of the total emissions) were the dominant monoterpenes. Proportions of ?-pinene and camphene were significantly lower and proportions of 3-carene, sabinene, ?-terpinene and terpinolene higher in the southernmost Saaremaa provenance compared to the other provenances. Total terpene emission rates (standardised to +20 °C) from stumps varied from 27 to 1582 mg h-1 m-2 when measured within 2-3 h after tree cutting. Emission rates decreased rapidly to between 2 and 79 mg h-1 m-2 at 50 days after cutting. The estimated daily terpene emission rates on a hectare basis from freshly cut stumps at a cut tree density of 2000 per ha varied depending on provenance. Estimated emission ranges were 100-710 g ha-1 d-1 and 137-970 g ha-1 d-1 in 40 and in 60 year-old forest stands, respectively. Our result suggests that emission directly from stump surfaces could be a significant source of monoterpene emissions for a few weeks after logging in a Scots pine stand, but provenance properties strongly affect resin flow from root to stump surface.

Kivimäenpää, Minna; Magsarjav, Narantsetseg; Ghimire, Rajendra; Markkanen, Juha-Matti; Heijari, Juha; Vuorinen, Martti; Holopainen, Jarmo K.

2012-12-01

60

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

Microsoft Academic Search

(1) 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

Trevor Keenan; Ülo Niinemets; Santi Sabate; Carlos Gracia; Josep Peñuelas

2009-01-01

61

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

Microsoft Academic Search

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

Trevor Keenan; Ülo Niinemets; Santi Sabate; Carlos Gracia; Josep Peñuelas

2009-01-01

62

Photochemical grid model implementation of VOC, NOx, and O3 source apportionment  

NASA Astrophysics Data System (ADS)

For the purposes of developing optimal emissions control strategies, efficient approaches are needed to identify the major sources or groups of sources that contribute to elevated ozone (O3) concentrations. Source based apportionment techniques implemented in photochemical grid models track sources through the physical and chemical processes important to the formation and transport of air pollutants. Photochemical model source apportionment has been used to estimate impacts of specific sources, groups of sources (sectors), sources in specific geographic areas, and stratospheric and lateral boundary inflow on O3. The implementation and application of a source apportionment technique for O3 and its precursors, nitrogen oxides (NOx) and volatile organic compounds (VOC), for the Community Multiscale Air Quality (CMAQ) model are described here. The Integrated Source Apportionment Method (ISAM) O3 approach is a hybrid of source apportionment and source sensitivity in that O3 production is attributed to precursor sources based on O3 formation regime (e.g., for a NOx-sensitive regime, O3 is apportioned to participating NOx emissions). This implementation is illustrated by tracking multiple emissions source sectors and lateral boundary inflow. NOx, VOC, and O3 attribution to tracked sectors in the application are consistent with spatial and temporal patterns of precursor emissions. The O3 ISAM implementation is further evaluated through comparisons of apportioned ambient concentrations and deposition amounts with those derived from brute force zero-out scenarios, with correlation coefficients ranging between 0.58 and 0.99 depending on specific combination of target species and tracked precursor emissions. Low correlation coefficients occur for chemical regimes that have strong non-linearity in O3 sensitivity, which demonstrates different functionalities between source apportionment and zero-out approaches, depending on whether sources of interest are either to be accounted for pollutant levels in a given scenario, or to be perturbed to invoke alternate scenarios.

Kwok, R. H. F.; Baker, K. R.; Napelenok, S. L.; Tonnesen, G. S.

2014-09-01

63

Biogenic and Anthropogenic VOC Emissions over the Central and Southern U.S.: Results from Recent Airborne Field Campaigns (Invited)  

NASA Astrophysics Data System (ADS)

Over the last two years, the NCAR Trace Organic Gas Analyzer (TOGA), capable of quantifying over 50 individual gas-phase volatile organic compounds (VOCs), was deployed on two airborne field campaigns with flights over the central and southeast United States: Deep Convective Cloud and Chemistry (DC3), and Nitrogen, Oxidants, Mercury and Aerosol Distributions, Sources and Sinks (NOMADSS). These studies provided opportunities to sample air masses dominated by individual emissions sources, including biomass burning, oil and gas extraction, biogenic activity, and marine emissions, as well as the impact of convection on recently emitted trace gases. Using observations of biogenic VOCs, including speciated monoterpenes, we will compare our findings with NCAR CESM CAM-chem model simulations using the MEGAN emissions inventory. Likewise, we will contrast our observations of anthropogenic VOCs over the continental U.S. to model simulations with anthropogenic inventories (e.g., NEI, EDGAR).

Hornbrook, R. S.; Apel, E. C.; Riemer, D. D.; Hills, A. J.; Kaser, L.; Emmons, L. K.; Lamarque, J.; Blake, N. J.; Simpson, I. J.; Blake, D. R.; Karl, T.; Yuan, B.

2013-12-01

64

VOC source-receptor relationships in Houston during TexAQS-II  

NASA Astrophysics Data System (ADS)

During the TRAMP field campaign in August-September 2006, C 2-C 10 volatile organic compounds (VOCs) were measured continuously and online at the urban Moody Tower (MT) site. This dataset 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 (CPF) 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. At MT natural gas/crude oil contributed most to the VOC mass (27.4%), followed by liquefied petroleum gas (16.7%), vehicular exhaust (15.3%), fuel evaporation (14.3%), and aromatics (13.4%). Also petrochemical sources from ethylene (4.7%) and propylene (3.6%) play an important role. A minor fraction of the VOC mass can be attributed to biogenic sources mainly from isoprene (4.4%). 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 about a third 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, Michael; Rappenglück, Bernhard

2010-10-01

65

Spatial/temporal variations and source apportionment of VOCs monitored at community scale in an urban area.  

PubMed

This study aimed to characterize spatial/temporal variations of ambient volatile organic compounds (VOCs) using a community-scale monitoring approach and identify the main sources of concern in Paterson, NJ, an urban area with mixed sources of VOCs. VOC samples were simultaneously collected from three local source-dominated (i.e., commercial, industrial, and mobile) sites in Paterson and one background site in Chester, NJ (located ?58 km southwest of Paterson). Samples were collected using the EPA TO-15 method from midnight to midnight, one in every sixth day over one year. Among the 60 analyzed VOCs, ten VOCs (acetylene, benzene, dichloromethane, ethylbenzene, methyl ethyl ketone, styrene, toluene, m,p-xylene, o-xylene, and p-dichlorobenzene) were selected to examine their spatial/temporal variations. All of the 10 VOCs in Paterson were significantly higher than the background site (p<0.01). Ethylbenzene, m,p-xylene, o-xylene, and p-dichlorobenzene measured at the commercial site were significantly higher than the industrial/mobile sites (p<0.01). Seven VOCs (acetylene, benzene, dichloromethane, methyl ethyl ketone, styrene, toluene, and p-dichlorobenzene) were significantly different by season (p<0.05), that is, higher in cold seasons than in warm seasons. In addition, dichloromethane, methyl ethyl ketone, and toluene were significantly higher on weekdays than weekend days (p<0.05). These results are consistent with literature data, indicating the impact of anthropogenic VOC sources on air pollution in Paterson. Positive Matrix Factorization (PMF) analysis was applied for 24-hour integrated VOC measurements in Paterson over one year and identified six contributing factors, including motor vehicle exhausts (20%), solvents uses (19%), industrial emissions (16%), mobile+stationery sources (12%), small shop emissions (11%), and others (22%). Additional locational analysis confirmed the identified sources were well matched with point sources located upwind in Paterson. The study demonstrated the community-scale monitoring approach can capture spatial variation of VOCs in an urban community with mixed VOC sources. It also provided robust data to identify major sources of concern in the community. PMID:24755686

Yu, Chang Ho; Zhu, Xianlei; Fan, Zhi-hua

2014-01-01

66

Spatial/Temporal Variations and Source Apportionment of VOCs Monitored at Community Scale in an Urban Area  

PubMed Central

This study aimed to characterize spatial/temporal variations of ambient volatile organic compounds (VOCs) using a community-scale monitoring approach and identify the main sources of concern in Paterson, NJ, an urban area with mixed sources of VOCs. VOC samples were simultaneously collected from three local source-dominated (i.e., commercial, industrial, and mobile) sites in Paterson and one background site in Chester, NJ (located ?58 km southwest of Paterson). Samples were collected using the EPA TO-15 method from midnight to midnight, one in every sixth day over one year. Among the 60 analyzed VOCs, ten VOCs (acetylene, benzene, dichloromethane, ethylbenzene, methyl ethyl ketone, styrene, toluene, m,p-xylene, o-xylene, and p-dichlorobenzene) were selected to examine their spatial/temporal variations. All of the 10 VOCs in Paterson were significantly higher than the background site (p<0.01). Ethylbenzene, m,p-xylene, o-xylene, and p-dichlorobenzene measured at the commercial site were significantly higher than the industrial/mobile sites (p<0.01). Seven VOCs (acetylene, benzene, dichloromethane, methyl ethyl ketone, styrene, toluene, and p-dichlorobenzene) were significantly different by season (p<0.05), that is, higher in cold seasons than in warm seasons. In addition, dichloromethane, methyl ethyl ketone, and toluene were significantly higher on weekdays than weekend days (p<0.05). These results are consistent with literature data, indicating the impact of anthropogenic VOC sources on air pollution in Paterson. Positive Matrix Factorization (PMF) analysis was applied for 24-hour integrated VOC measurements in Paterson over one year and identified six contributing factors, including motor vehicle exhausts (20%), solvents uses (19%), industrial emissions (16%), mobile+stationery sources (12%), small shop emissions (11%), and others (22%). Additional locational analysis confirmed the identified sources were well matched with point sources located upwind in Paterson. The study demonstrated the community-scale monitoring approach can capture spatial variation of VOCs in an urban community with mixed VOC sources. It also provided robust data to identify major sources of concern in the community. PMID:24755686

Yu, Chang Ho; Zhu, Xianlei; Fan, Zhi-hua

2014-01-01

67

Uncertainty assessment of VOC emissions from paint in The Netherlands using the NUSAP system.  

PubMed

We demonstrate an innovative approach to uncertainty assessment known as the NUSAP system, to assess qualitative and quantitative uncertainty for the case of emissions of volatile organic compounds (VOC) from paint in The Netherlands. Using expert elicitation, we identified key sources of error, critical assumptions, and bias in the monitoring process. We assessed pedigree and probabilistic uncertainty of all input quantities. We used four pedigree criteria to assess the strength of the knowledge base: proxy representation, empirical basis, methodological rigour and degree of validation. Using Monte Carlo analysis, we assessed sensitivity and propagation of uncertainty. Results for sensitivity and pedigree were combined in a 'NUSAP Diagnostic Diagram', which effectively highlighted the assumption for VOC percentage of imported paint as the weakest spot in the monitoring of VOC emissions. We conclude that NUSAP facilitates systematic scrutinization of method and underlying assumptions and structures creative thinking on sources of error and bias. It provides a means to prioritise uncertainties and focus research efforts on the potentially most problematic parameters and assumptions, at the same time identifying specific weaknesses in the knowledge base. With NUSAP, nuances of meaning about quantities can be conveyed concisely and clearly, to a degree that is not possible with statistic methods only. PMID:15952522

Van der Sluijs, Jeroen P; Risbey, James S; Ravetz, Jerry

2005-06-01

68

Chlorinated volatile organic compounds (Cl-VOCs) in environment - sources, potential human health impacts, and current remediation technologies.  

PubMed

Chlorinated volatile organic compounds (Cl-VOCs), including polychloromethanes, polychloroethanes and polychloroethylenes, are widely used as solvents, degreasing agents and a variety of commercial products. These compounds belong to a group of ubiquitous contaminants that can be found in contaminated soil, air and any kind of fluvial mediums such as groundwater, rivers and lakes. This review presents a summary of the research concerning the production levels and sources of Cl-VOCs, their potential impacts on human health as well as state-of-the-art remediation technologies. Important sources of Cl-VOCs principally include the emissions from industrial processes, the consumption of Cl-VOC-containing products, the disinfection process, as well as improper storage and disposal methods. Human exposure to Cl-VOCs can occur through different routes, including ingestion, inhalation and dermal contact. The toxicological impacts of these compounds have been carefully assessed, and the results demonstrate the potential associations of cancer incidence with exposure to Cl-VOCs. Most Cl-VOCs thus have been listed as priority pollutants by the Ministry of Environmental Protection (MEP) of China, Environmental Protection Agency of the U.S. (U.S. EPA) and European Commission (EC), and are under close monitor and strict control. Yet, more efforts will be put into the epidemiological studies for the risk of human exposure to Cl-VOCs and the exposure level measurements in contaminated sites in the future. State-of-the-art remediation technologies for Cl-VOCs employ non-destructive methods and destructive methods (e.g. thermal incineration, phytoremediation, biodegradation, advanced oxidation processes (AOPs) and reductive dechlorination), whose advantages, drawbacks and future developments are thoroughly discussed in the later sections. PMID:25016450

Huang, Binbin; Lei, Chao; Wei, Chaohai; Zeng, Guangming

2014-10-01

69

Biogenic VOCs emission inventory development of temperate grassland vegetation in Xilin River basin, Inner Mongolia, China.  

PubMed

Given the key role of biogenic volatile organic compounds (VOCs) to tropospheric chemistry and regional air quality, it is important to generate accurate VOCs emission inventories. However, only a less fraction of plant species, in temperate grassland of Inner Mongolia, has been characterized by quantitative measurements. A taxonomic methodology, which assigns VOCs measurements to unmeasured species, is an applicable and inexpensive alternation for extensive VOCs emission survey, although data are needed for additional plant families and genera to further validate the taxonomic approach in grassland vegetation. In this experiment, VOCs emission rates of 178 plant species were measured with a portable photoionization detector (PID). The results showed the most of genera and some families have consistent feature of their VOCs emission, especially for isoprene, and provide the basic premise of taxonomic methodology to develop VOCs emission inventories for temperate grassland. Then, the taxonomic methodology was introduced into assigning emission rate to other 96 species, which no measured emission rates available here. A systematical emission inventory of temperate grassland vegetation in Inner Mongolia was provided and further evidence that taxonomy relationship can serve as a useful guide for generalizing the emissions behavior of many, but not all, plant families and genera to grassland vegetation. PMID:15900743

He, Nian-Peng; Han, Xing-Guo; Sun, Wei; Pan, Qing-Min

2004-01-01

70

Emission of biogenic VOCs from trees in the Lower Fraser Valley, B.C.  

SciTech Connect

Biogenic volatile organic compounds (VOC`s) are known to participate in the formation of ground level ozone. It is possible that in the areas with high emission rates from local vegetation, biogenic hydrocarbons can be of comparable importance to anthropogenic hydrocarbons in the production of this secondary air pollutant. In order to implement an effective abatement strategy, the relative importance of these biogenic emissions to the atmospheric chemistry of an area must be known. The Lower Fraser Valley located in the southwestern corner of British Columbia experiences episodes of elevated ground level ozone concentrations during the summer under the influence of a stationary high pressure system and characterized by lush coastal rain forest vegetation and extensive agriculture surfaces. During the summer of 1995 a field campaign to determine the emission rate from natural sources in the region was conducted. The emission rate from natural sources in the region was conducted. The mission rate of biogenic hydrocarbons from four tree species, Western Red Cedar (Thuja Plicata), Cottonwood (Populus Balsemifera), Douglass Fir (Pseudotsuga Menziesii) and Hemlock (Tsuga Heterophylla) was measured in the field. It was found that Cottonwood trees emit isoprene at a rate approaching 100 times greater than any of the other three species.

Drewitt, G.; Styen, D.G. [Univ. of British Columbia, Vancouver (Canada); Gillespie, T.; Curren, K. [Univ. of Guelph, Ontario (Canada)

1996-12-31

71

Modeling VOC emissions and air concentrations from the Exxon Valdez oil spill  

SciTech Connect

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 weeks of the spill. A multicomponent evaporative emissions model was developed and applied to the oil spill; the model considered the evaporation of 15 specific compounds, including benzene and toluene. Both mass transfer from the surface of the spill and diffusion through the oil layer were considered in the emissions model. Maximum emissions of toluene were calculated to equal about 20,000 kg/hr, or about 5 g/m[sup 2] hr, at a time of eight hours after the initial oil spill. Meteorological data were acquired from sources and used to estimate hourly-averaged wind velocity over the spill. Air concentrations of specific components were calculated using the ATDL area source diffusion model and the Offshore and Coastal Dispersion (OCD) model. Maximum hourly-averaged concentrations were predicted not to exceed 10 ppmv for any compound. 24 refs., 6 figs., 4 tabs.

Hanna, S.R. (Sigma Research Corp., Concord, MA (United States)); Drivas, P.J. (Gradient Corp., Cambridge, MA (United States))

1993-03-01

72

VOC species and emission inventory from vehicles and their SOA formation potentials estimation in Shanghai, China  

NASA Astrophysics Data System (ADS)

VOC species from vehicle exhaust and gas evaporation were investigated by chassis dynamometer and on-road measurements of 9 gasoline vehicles, 7 diesel vehicles, 5 motorcycles, and 4 gas evaporation samples. The SOA mass yields of gasoline, diesel, motorcycle exhausts, and gas evaporation were calculated based on the mixing ratio of individual VOC species. The SOA mass yields of gasoline and motorcycle exhaust were similar to the results of the published smog chamber study with the exception of that of diesel exhaust was 20% lower than experimental data (Gordon et al., 2013, 2014a, b). This suggests the requirement for further research on SVOC or LVOC emissions. A vehicular emission inventory was compiled based on a local survey of vehicle mileage traveled and real-world measurements of vehicle emission factors. The inventory-based vehicular initial emission ratio of OA to CO was 15.6 ?g m-3 ppmv-1. The OA production rate reached 22.3 and 42.7 ?g m-3 ppmv-1 under high-NOx and low-NOx conditions, respectively. To determine the vehicular contribution to OA pollution, the inventory-based OA formation ratios for vehicles were calculated with a photochemical-age-based parameterization method and compared with the observation-based OA formation ratios in the urban atmosphere of Shanghai. The results indicated that VOC emissions from vehicle exhaust and gas evaporation only explained 15 and 22% of the total organic aerosols observed in summer and winter, respectively. SOA production only accounted for 25 and 18% of the total vehicular OA formation in summer and winter. VOC emissions from gasoline vehicles contribute 21-38% of vehicular OA formation after 6-24 h of photochemical aging. The results suggest that vehicle emissions are an important contributor to OA pollution in the urban atmosphere of Shanghai. However, a large number of OA mass in the atmosphere still cannot be explained in this study. SOA formation contributions from other sources (e.g. coal burning, biomass burning, cooking, dust, etc.) as well as IVOCs and SVOCs from the combustion sources need to be considered in future studies.

Huang, C.; Wang, H. L.; Li, L.; Wang, Q.; Lu, Q.; de Gouw, J. A.; Zhou, M.; Jing, S. A.; Lu, J.; Chen, C. H.

2015-03-01

73

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

74

Surface emission determination of volatile organic compounds (VOC) from a closed industrial waste landfill using a self-designed static flux chamber.  

PubMed

Closed landfills can be a source of VOC and odorous nuisances to their atmospheric surroundings. A self-designed cylindrical air flux chamber was used to measure VOC surface emissions in a closed industrial landfill located in Cerdanyola del Vallès, Catalonia, Spain. The two main objectives of the study were the evaluation of the performance of the chamber setup in typical measurement conditions and the determination of the emission rates of 60 different VOC from that industrial landfill, generating a valuable database that can be useful in future studies related to industrial landfill management. Triplicate samples were taken in five selected sampling points. VOC were sampled dynamically using multi-sorbent bed tubes (Carbotrap, Carbopack X, Carboxen 569) connected to SKC AirCheck 2000 pumps. The analysis was performed by automatic thermal desorption coupled with a capillary gas chromatograph/mass spectrometry detector. The emission rates of sixty VOC were calculated for each sampling point in an effort to characterize surface emissions. To calculate average, minimum and maximum emission values for each VOC, the results were analyzed by three different methods: Global, Kriging and Tributary area. Global and Tributary area methodologies presented similar values, with total VOC emissions of 237 ± 48 and 222 ± 46 g day(-1), respectively; however, Kriging values were lower, 77 ± 17 gd ay(-1). The main contributors to the total emission rate were aldehydes (nonanal and decanal), acetic acid, ketones (acetone), aromatic hydrocarbons and alcohols. Most aromatic hydrocarbon (except benzene, naphthalene and methylnaphthalenes) and aldehyde emission rates exhibited strong correlations with the rest of VOC of their family, indicating a possible common source of these compounds. B:T ratio obtained from the emission rates of the studied landfill suggested that the factors that regulate aromatic hydrocarbon distributions in the landfill emissions are different from the ones from urban areas. Environmental conditions (atmospheric pressure, temperature and relative humidity) did not alter the pollutant emission fluxes. PMID:24176707

Gallego, E; Perales, J F; Roca, F J; Guardino, X

2014-02-01

75

Analysis of UK and European NOx and VOC emission scenarios in the Defra model intercomparison exercise  

NASA Astrophysics Data System (ADS)

Simple emission scenarios have been implemented in eight United Kingdom air quality models with the aim of assessing how these models compared when addressing whether photochemical ozone formation in southern England was NOx- or VOC-sensitive and whether ozone precursor sources in the UK or in the Rest of Europe (RoE) were the most important during July 2006. The suite of models included three Eulerian-grid models (three implementations of one of these models), a Lagrangian atmospheric dispersion model and two moving box air parcel models. The assignments as to NOx- or VOC-sensitive and to UK- versus RoE-dominant, turned out to be highly variable and often contradictory between the individual models. However, when the assignments were filtered by model performance on each day, many of the contradictions could be eliminated. Nevertheless, no one model was found to be the 'best' model on all days, indicating that no single air quality model could currently be relied upon to inform policymakers robustly in terms of NOx- versus VOC-sensitivity and UK- versus RoE-dominance on each day. It is important to maintain a diversity in model approaches.

Derwent, Richard; Beevers, Sean; Chemel, Charles; Cooke, Sally; Francis, Xavier; Fraser, Andrea; Heal, Mathew R.; Kitwiroon, Nutthida; Lingard, Justin; Redington, Alison; Sokhi, Ranjeet; Vieno, Massimo

2014-09-01

76

Contrasting winter and summer VOC mixing ratios at a forest site in the Western Mediterranean Basin: the effect of local biogenic emissions  

NASA Astrophysics Data System (ADS)

Atmospheric volatile organic compounds (VOCs) are involved in ozone and aerosol generation, thus having implications for air quality and climate. VOCs and their emissions by vegetation also have important ecological roles as they can protect plants from stresses and act as communication cues between plants and between plants and animals. In spite of these key environmental and biological roles, the reports on seasonal and daily VOC mixing ratios in the literature for Mediterranean natural environments are scarce. We conducted seasonal (winter and summer) measurements of VOC mixing ratios in an elevated (720 m a.s.l.) holm oak Mediterranean forest site near the metropolitan area of Barcelona (NE Iberian peninsula). Methanol was the most abundant compound among all the VOCs measured in both seasons. While aromatic VOCs showed almost no seasonal variability, short-chain oxygenated VOCs presented higher mixing ratios in summer, presumably due to greater emission by vegetation and increased photochemistry, both enhanced by the high temperatures and solar radiation in summer. Isoprenoid VOCs showed the biggest seasonal change in mixing ratios: they increased by one order of magnitude in summer, as a result of the vegetation's greater physiological activity and emission rates. The maximum diurnal concentrations of ozone increased in summer too, most likely due to more intense photochemical activity and the higher levels of VOCs in the air. The daily variation of VOC mixing ratios was mainly governed by the wind regime of the mountain, as the majority of the VOC species analyzed followed a very similar diel cycle. Mountain and sea breezes that develop after sunrise advect polluted air masses to the mountain. These polluted air masses had previously passed over the urban and industrial areas surrounding the Barcelona metropolitan area, where they were enriched in NOx and in VOCs of biotic and abiotic origin. Moreover, these polluted air masses receive additional biogenic VOCs emitted in the local valley by the vegetation, thus enhancing O3 formation in this forested site. The only VOC species that showed a somewhat different daily pattern were monoterpenes because of their local biogenic emission. Isoprene also followed in part the daily pattern of monoterpenes, but only in summer when its biotic sources were stronger. The increase by one order of magnitude in the concentrations of these volatile isoprenoids highlights the importance of local biogenic summer emissions in these Mediterranean forested areas which also receive polluted air masses from nearby or distant anthropic sources.

Seco, R.; Peñuelas, J.; Filella, I.; Llusià, J.; Molowny-Horas, R.; Schallhart, S.; Metzger, A.; Müller, M.; Hansel, A.

2011-07-01

77

Contrasting winter and summer VOC mixing ratios at a forest site in the Western Mediterranean Basin: the effect of local biogenic emissions  

NASA Astrophysics Data System (ADS)

Atmospheric volatile organic compounds (VOCs) are involved in ozone and aerosol generation, thus having implications for air quality and climate. VOCs and their emissions by vegetation also have important ecological roles as they can protect plants from stresses and act as communication cues between plants and between plants and animals. In spite of these key environmental and biological roles, the reports on seasonal and daily VOC mixing ratios in the literature for Mediterranean natural environments are scarce. We conducted seasonal (winter and summer) measurements of VOC mixing ratios in an elevated (720 m a.s.l.) holm oak Mediterranean forest site near the metropolitan area of Barcelona (NE Iberian Peninsula). Methanol was the most abundant compound among all the VOCs measured in both seasons. While aromatic VOCs showed almost no seasonal variability, short-chain oxygenated VOCs presented higher mixing ratios in summer, presumably due to greater emission by vegetation and increased photochemistry, both enhanced by the high temperatures and solar radiation in summer. Isoprenoid VOCs showed the biggest seasonal change in mixing ratios: they increased by one order of magnitude in summer, as a result of the vegetation's greater physiological activity and emission rates. The maximum diurnal concentrations of ozone increased in summer too, most likely due to more intense photochemical activity and the higher levels of VOCs in the air. The daily variation of VOC mixing ratios was mainly governed by the wind regime of the mountain, as the majority of the VOC species analyzed followed a very similar diel cycle. Mountain and sea breezes that develop after sunrise advect polluted air masses to the mountain. These polluted air masses had previously passed over the urban and industrial areas surrounding the Barcelona metropolitan area, where they were enriched in NOx and in VOCs of biotic and abiotic origin. Moreover, these polluted air masses receive additional biogenic VOCs emitted in the local valley by the vegetation, thus enhancing O3 formation in this forested site. The only VOC species that showed a somewhat different daily pattern were monoterpenes because of their local biogenic emission. Isoprene also followed in part the daily pattern of monoterpenes, but only in summer when its biotic sources were stronger. The increase by one order of magnitude in the concentrations of these volatile isoprenoids highlights the importance of local biogenic summer emissions in these Mediterranean forested areas which also receive polluted air masses from nearby or distant anthropic sources.

Seco, R.; Peñuelas, J.; Filella, I.; Llusià, J.; Molowny-Horas, R.; Schallhart, S.; Metzger, A.; Müller, M.; Hansel, A.

2011-12-01

78

VOC EMISSION REDUCTION STUDY AT THE HILL AIR FORCE BASE BUILDING 515 PAINTING FACILITY  

EPA Science Inventory

The report describes the development of safe and cost effective strategies for controlling volatile organic compound (voc) emissions from Air Force painting facilities. A series of sampling and analysis tests were conducted to measure hazardous constituent compound concentrations...

79

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

80

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

81

Optimizing the emission inventory of volatile organic compounds (VOCs) based on network observations  

NASA Astrophysics Data System (ADS)

Hourly observations of 56 non-methane hydrocarbons (NMHCs) performed by a network of photochemical assessment monitoring stations (PAMS) at 11 locations across Taiwan were used to evaluate 56 speciated emissions and the resulting simulations of an air quality model. Based on the PAMS observations at two urban sites, emission modification was made for the 56 PAMS species in the model. To further test the applicability of this emission correction approach, the same modified emissions were subject to seven different meteorological conditions and comparison with observations of all the 11 PAMS sites. Originally there was a minimum of only 8 of 56 species showed agreement with observations for the worst of the 11 PAMS sites and 28 of 56 species for the best site. With modified emissions, the number increased to 13-52 species across the 11 PAMS sites, demonstrating that the simple urban based correction procedure has broad applicability. When applying this modification of PAMS emissions to the simulations of other air quality gases, SO2 and NOx showed small changes compared with observations (-0.27% and -2.51%, respectively), while total VOC concentrations showed significant changes (+15.28%) as a result of the adjustment in VOC emissions (+26.7%). Although VOCs are the precursor of ozone, the relatively large changes in VOC did not seem to affect ozone formation to the similar extent, only resulting in the changes of average O3 by 2.9 ppb (+9.41%). It shows that although the emission modification improves individual VOC simulations, the performance in oxidant simulation is still largely unaltered. Although the original U.S. VOC emission profiles can capture the general features of ambient VOCs, further optimization of emissions may still be needed by referencing extensive observations, so that emissions can better fit domestic conditions and accuracy in model simulations can be improved.

Chen, Sheng-Po; Liu, Wen-Tzu; Ou-Yang, Chang-Feng; Chang, Julius S.; Wang, Jia-Lin

2014-02-01

82

Emissions of Volatile Organic Compounds (VOCs) Associated with Natural Gas Production in the Uintah Basin, Utah  

NASA Astrophysics Data System (ADS)

Technological advances such as hydraulic fracturing have led to a rapid increase in the production of natural gas from several basins in the Rocky Mountain West, including the Denver-Julesburg basin in Colorado, the Uintah basin in Utah and the Upper Green River basin in Wyoming. There are significant concerns about the impact of natural gas production on the atmosphere, including (1) emissions of methane, which determine the net climate impact of this energy source, (2) emissions of reactive hydrocarbons and nitrogen oxides, and their contribution to photochemical ozone formation, and (3) emissions of air toxics with direct health effects. The Energy & Environment - Uintah Basin Wintertime Ozone Study (UBWOS) in 2012 was focused on addressing these issues. During UBWOS, measurements of volatile organic compounds (VOCs) were made using proton-transfer-reaction mass spectrometry (PTR-MS) instruments from a ground site and a mobile laboratory. Measurements at the ground site showed mixing ratios of VOCs related to oil and gas extraction were greatly enhanced in the Uintah basin, including several days long periods of elevated mixing ratios and concentrated short term plumes. Diurnal variations were observed with large mixing ratios during the night caused by low nighttime mixing heights and a shift in wind direction during the day. The mobile laboratory sampled a wide variety of individual parts of the gas production infrastructure including active gas wells and various processing plants. Included in those point sources was a new well that was sampled by the mobile laboratory 11 times within two weeks. This new well was previously hydraulically fractured and had an active flow-back pond. Very high mixing ratios of aromatics were observed close to the flow-back pond. The measurements of the mobile laboratory are used to determine the source composition of the individual point sources and those are compared to the VOC enhancement ratios observed at the ground site. The source composition of most point sources was similar to the typical enhancement ratios observed at the ground site, whereas the new well with the flow-back pond showed a somewhat different composition.

Warneke, C.; Geiger, F.; Zahn, A.; Graus, M.; De Gouw, J. A.; Gilman, J. B.; Lerner, B. M.; Roberts, J. M.; Edwards, P. M.; Dube, W. P.; Brown, S. S.; Peischl, J.; Ryerson, T. B.; Williams, E. J.; Petron, G.; Kofler, J.; Sweeney, C.; Karion, A.; Dlugokencky, E. J.

2012-12-01

83

The effect of wet film thickness on VOC emissions from a finishing varnish.  

PubMed

Finishing varnishes, a typical type of oil-based varnishes, are widely used to shine metal, wood trim and cabinet surfaces in Hong Kong. The influence of wet film thickness on volatile organic compound (VOC) emissions from a finishing varnish was studied in an environmental test chamber. The varnish was applied on an aluminium foil with three different wet film thickness (35.2, 69.9 and 107.3 microm). The experimental conditions were 25.0 degrees C, 50.0% relative humidity (RH) with an air exchange rate of 0.5 h(-1). The concentrations of the major VOCs were monitored for the first 10 h. The air samples were collected by canisters and analysed by gas chromatography/mass selective detector (GC/MSD). Six major VOCs including toluene, chlorobenzene, ethylbenzene, m,p-xylene, o-xylene and 1,3,5-trimethylbenzene were identified and quantified. Marked differences were observed for three different film thicknesses. VOC concentrations increased rapidly during the first few hours and then decreased as the emission rates declined. The thicker the wet film, the higher the VOC emissions. A model expression included an exponentially decreasing emission rate of varnish film. The concentration and time data measured in the chamber were used to determine the parameters of empirical emission rate model. The present work confirmed that the film thickness of varnish influenced markedly the concentrations and emissions of VOCs. PMID:12526899

Lee, Shun-Cheng; Kwok, Ngai-Hong; Guo, Hai; Hung, Wing-Tat

2003-01-20

84

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

SciTech Connect

The report gives results of laboratory tests to evaluate commercially available latex paints advertised as `low-odor,` `low-VOC (volatile organic compound),` or `no-VOC.` Measurements were performed to quantify the total content of VOCs in the paints and to identify the predominant VOCs and aldehydes in the emissions following application to test substrates. The performance of the paints was evaluated and compared to that of commonly used conventional latex paints by American Society for Testing and Materials (ASTM) standard methods that measured parameters such as scrubbability, cleanability, and hiding power. The report describes the paints that were tested, the test methods, and the experimental data. Results are presented that can be used to evaluate the low-odor/low-VOC paints as alternatives to conventional latex wall paints that contain and emit higher concentrations of VOCs.

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

1999-04-01

85

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...

86

APPORTIONMENT OF RESIDENTIAL INDOOR AEROSOL, VOC AND ALDEHYDESPECIES TO INDOOR AND OUTDOOR SOURCES  

EPA Science Inventory

The average concentrations of a large number of fine particleaerosol, VOC and aldehyde species measured in ten Boise, IDresidences in wintertime have been apportioned according to theircontributions from all inside sources and all outside sources. hemethod depends on the availabi...

87

[Study on concentration, ozone production potential and sources of VOCs in the atmosphere of Beijing during Olympics period].  

PubMed

Volatile organic compounds (VOCs) is one of the key precursors of atmospheric ozone (O3), whose concentration variation influences directly the level of the photochemical pollutant O3. During Beijing Olympics, VOCs were measured near the Beijing National Stadium. Two and half-hour integrated canister samples were collected and analyzed in the morning and afternoon of each sampling day. Simultaneously, concentration, potential ozone production and sources of VOCs in the atmosphere of Beijing were studied. And the results indicated that the total VOCs species had higher concentrations in the morning (34.38 x 10(-9)), and lower in the afternoon (27.13 x 10(-9)), where the concentration of alkanes was the highest, and aromatics and alkenes came next. However, the concentrations of alkenes in the afternoon were significantly lower than those in the morning, which was 28%, and aromatics (26%) and alkanes (15%) came next. 1,2,4-Trimethylbenzene has the highest propylene-equivalent concentration (8.05 x 10(-9)C), and m/p-xylene (6.97 x 10(-9)C), toluene (6.41 x 10(-9)C) and 1,3,5-trimethylbenzene (5.64 x 10(-9) C) came next. Aromatics (47%) gives the most significant contribution to the production of O3 in the atmospheric VOCs of Beijing, and then were alkenes (40%) and alkanes (13%). Automobile emissions accounted for approximately 28% of the total VOCs, and solvent volatilization (19%), LPG leakage (15%) and industrial sources (12%) came next, from which Beijing may decrease the atmospheric VOCs. PMID:20329509

Wu, Fang-Kun; Wang, Yue-Si; An, Jun-Lin; Zhang, Jun-Gang

2010-01-01

88

Human health risk evaluation of selected VOC, SVOC and particulate emissions from scented candles.  

PubMed

Airborne compounds in the indoor environment arise from a wide variety of sources such as environmental tobacco smoke, heating and cooking, construction materials as well as outdoor sources. To understand the contribution of scented candles to the indoor load of airborne substances and particulate matter, candle emission testing was undertaken in environmentally controlled small and large emission chambers. Candle emission rates, calculated on the basis of measured chamber concentrations of volatile and semi-volatile organic compounds (VOC, SVOC) and particulate matter (PM), were used to predict their respective indoor air concentrations in a standard EU-based dwelling using 2 models: the widely accepted ConsExpo 1-box inhalation model and the recently developed RIFM 2-box indoor air dispersion model. The output from both models has been used to estimate more realistic consumer exposure concentrations of specific chemicals and PM in candle emissions. Potential consumer health risks associated with the candle emissions were characterized by comparing the exposure concentrations with existing indoor or ambient air quality guidelines or, where not existent, to established toxicity thresholds. On the basis of this investigation it was concluded that under normal conditions of use scented candles do not pose known health risks to the consumer. PMID:24582651

Petry, Thomas; Vitale, Danielle; Joachim, Fred J; Smith, Ben; Cruse, Lynn; Mascarenhas, Reuben; Schneider, Scott; Singal, Madhuri

2014-06-01

89

VOC emissions from residential combustion of Southern and mid-European woods  

NASA Astrophysics Data System (ADS)

Emissions of trace gases (carbon dioxide (CO2), carbon monoxide (CO), total hydrocarbons (THC)), and volatile organic compounds (VOCs) from combustion of European beech, Pyrenean oak and black poplar in a domestic woodstove and fireplace were studied. These woods are widely used as biofuel in residential combustion in Southern and mid-European countries. VOCs in the flue gases were collected in Tedlar bags, concentrated in sorbent tubes and analysed by thermal desorption-gas chromatography-flame ionisation detection (GC-FID). CO2 emissions ranged from 1415 ± 136 to 1879 ± 29 g kg-1 (dry basis). The highest emission factors for CO and THC, 115.8 ± 11.7 and 95.6 24.7 ± 6.3 g kg-1 (dry basis), respectively, were obtained during the combustion of black poplar in the fireplace. European beech presented the lowest CO and THC emission factors for both burning appliances. Significant differences in emissions of VOCs were observed among wood species burnt and combustion devices. In general the highest emission factors were obtained from the combustion of Pyrenean oak in the woodstove. Among the VOCs identified, benzene and related compounds were always the most abundant group, followed by oxygenated compounds and aliphatic hydrocarbons. The amount and the composition of emitted VOCs were strongly affected by the wood composition, the type of burning device and operating conditions. Emission data obtained in this work are useful for modelling the impact of residential wood combustion on air quality and tropospheric ozone formation.

Evtyugina, Margarita; Alves, Célia; Calvo, Ana; Nunes, Teresa; Tarelho, Luís; Duarte, Márcio; Prozil, Sónia O.; Evtuguin, Dmitry V.; Pio, Casimiro

2014-02-01

90

Source Signature of Volatile Organic Compounds (VOCs) associated with oil and natural gas operations in Utah and Colorado  

NASA Astrophysics Data System (ADS)

The U.S. Energy Information Administration has reported a sharp increase in domestic oil and natural gas production from "unconventional" reserves (e.g., shale and tight sands) between 2005 and 2012. The recent growth in drilling and fossil fuel production has led to environmental concerns regarding local air quality. Severe wintertime ozone events (greater than 100 ppb ozone) have been observed in Utah's Uintah Basin and Wyoming's Upper Green River Basin, both of which contain large natural gas fields. Raw natural gas is a mixture of approximately 60-95 mole percent methane while the remaining fraction is composed of volatile organic compounds (VOCs) and other non-hydrocarbon gases. We measured an extensive set of VOCs and other trace gases near two highly active areas of oil and natural gas production in Utah's Uintah Basin and Colorado's Denver-Julesburg Basin in order to characterize primary emissions of VOCs associated with these industrial operations and identify the key VOCs that are precursors for potential ozone formation. UBWOS (Uintah Basin Winter Ozone Study) was conducted in Uintah County located in northeastern Utah in January-February 2012. Two Colorado studies were conducted at NOAA's Boulder Atmospheric Observatory in Weld County in northeastern Colorado in February-March 2011 and July-August 2012 as part of the NACHTT (Nitrogen, Aerosol Composition, and Halogens on a Tall Tower) and SONNE (Summer Ozone Near Natural gas Emissions) field experiments, respectively. The C2-C6 hydrocarbons were greatly enhanced for all of these studies. For example, the average propane mixing ratio observed during the Utah study was 58 ppb (median = 35 ppb, minimum = 0.8, maximum = 520 ppb propane) compared to urban averages which range between 0.3 and 6.0 ppb propane. We compare the ambient air composition from these studies to urban measurements in order to show that the VOC source signature from oil and natural gas operations is distinct and can be clearly distinguished from typical urban emissions associated with on-road combustion sources. We show that each geologic basin has a unique VOC source signature. We will examine the effects of photochemical processing of the primary VOC emissions by comparing the composition and OH reactivity for the wintertime studies to the summertime when there is active photochemistry occurring.

Gilman, J.; Lerner, B. M.; Warneke, C.; Holloway, J. S.; Peischl, J.; Ryerson, T. B.; Young, C. J.; Edwards, P.; Brown, S. S.; Wolfe, D. E.; Williams, E. J.; De Gouw, J. A.

2012-12-01

91

Application and limitations of a mass transfer VOC emission model for a dry building material  

NASA Astrophysics Data System (ADS)

Volatile organic compound (VOC) emission from building materials into air has been quantified, characterized and modeled. Internal diffusion of VOC through a material based on Fick's law of diffusion is the basis for mass transfer modeling of diffusive emission used to estimate VOC concentrations in air over time. Current mass transfer models have been shown to appropriately estimate air VOC concentrations at approximate room temperature, while other research has shown that temperature has a profound effect on the diffusion coefficient, D, of VOC in a material. Here, a mass transfer model is operated at 23 °C and 40 °C using input parameters applicable for each temperature. The model estimates are validated against environmental test chamber data for styrene emission from a vinyl ester resin thermoset composite material. The model correlates well with the 23 °C chamber data, but underestimates chamber data by as much as 10-4 at 264 h for the 40 °C modeling. This suggests that the model requires adjustment for predicting VOC air concentrations at temperatures other than 23 °C.

Crawford, S.; Lungu, C. T.

2013-12-01

92

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

93

Assessment of VOC emissions and their control from baker's yeast manufacturing facilities. Final report  

SciTech Connect

The Environmental Protection Agency's (EPA's) Control Technology Center (CTC) conducted a study to obtain information on the baker's yeast manufacturing industry. Baker's yeast is produced by a fermentation process that generates large quantities of ethanol and acetaldehyde. Currently, 13 facilities produce baker's yeast in the United States. The volatile organic compound (VOC) emission rate from a typical facility is estimated at 82 megagrams per year (90 tons per year). The majority of these emissions occurs in the final trade fermentations. The VOC emission alternatives that were evaluated during the study were process control measures to reduce the formation of VOC emissions as well as wet scrubbers, carbon adsorbers, incinerators, condensers, and biological filters to control VOC emissions. Of these approaches, it appears that process control measures, catalytic incinerators, or a combination of add-on control techniques (e.g., wet scrubbers followed by an incinerator or a biological filter) are the most feasible approaches for controlling yeast process emissions. Based on the results of the study, the control efficiency associated with the add-on control systems is estimated to be 95 to 98 percent. The report contains information on the baker's yeast fermentation process, the number and locations of yeast plants, the potential emissions from the process, and an evaluation of potential emission control options.

Barker, R.; Williamson, M.

1992-01-01

94

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

EPA Science Inventory

The paper discusses the measurment and analysis of the patterns of formaldehyde emission from a low volatile organic compound (VOC) latex paint applied to gypsum board, using small environmental chamber tests. The formaldehyde emissions resulted in sharp increase of chamber air...

95

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

EPA Science Inventory

The patterns of formaldehyde emission from a low volatile organic compound (VOC) latex paint applied to gypsum board were measured and analyzed by small environmental chamber tests. It was found that the formaldehyde emissions resulted in sharp increase of chamber air formaldehy...

96

40 CFR Table 1 to Subpart Jjjj of... - NOX, CO, and VOC Emission Standards for Stationary Non-Emergency SI Engines ?100 HP (Except...  

Code of Federal Regulations, 2013 CFR

... NOX, CO, and VOC Emission Standards for Stationary...â¥100 HP (Except Gasoline and Rich Burn LPG...NOX , CO, and VOC Emission Standards for Stationary...100 HP (Except Gasoline and Rich Burn LPG... Manufacturedate Emission standards a...

2013-07-01

97

40 CFR Table 1 to Subpart Jjjj of... - NOX, CO, and VOC Emission Standards for Stationary Non-Emergency SI Engines ?100 HP (Except...  

Code of Federal Regulations, 2012 CFR

... NOX, CO, and VOC Emission Standards for Stationary...â¥100 HP (Except Gasoline and Rich Burn LPG...NOX , CO, and VOC Emission Standards for Stationary...100 HP (Except Gasoline and Rich Burn LPG... Manufacturedate Emission standards a...

2012-07-01

98

40 CFR Table 1 to Subpart Jjjj of... - NOX, CO, and VOC Emission Standards for Stationary Non-Emergency SI Engines ?100 HP (Except...  

Code of Federal Regulations, 2014 CFR

... NOX, CO, and VOC Emission Standards for Stationary...â¥100 HP (Except Gasoline and Rich Burn LPG...NOX , CO, and VOC Emission Standards for Stationary...100 HP (Except Gasoline and Rich Burn LPG... Manufacturedate Emission standards a...

2014-07-01

99

40 CFR Table 1 to Subpart Jjjj of... - NOX, CO, and VOC Emission Standards for Stationary Non-Emergency SI Engines ?100 HP (Except...  

Code of Federal Regulations, 2010 CFR

... NOX, CO, and VOC Emission Standards for Stationary...â¥100 HP (Except Gasoline and Rich Burn LPG...NOX , CO, and VOC Emission Standards for Stationary...100 HP (Except Gasoline and Rich Burn LPG... Manufacture date Emission standards a...

2010-07-01

100

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 the chemical loss 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, but the emission ratios of oxygenated VOCs (OVOCs) are significantly lower than those from emission inventory. The photochemical age based parameterization method is also used to investigate primary emissions and secondary formation of organic aerosol. The primary emission ratio of OA to CO are determined to be 14.9 ?g m-3 ppm-1 and 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 condition (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. SOA formation potential of primary VOC emissions determined from both field campaigns and emission inventory in China are lower than the measured SOA levels reported in Beijing and Pearl River Delta (PRD), indicating SOA formation cannot be explained by VOC oxidation in this regions. SOA budget in China is estimated to be 5.0-13.7 Tg yr-1, with a fraction of at least 2.7 Tg yr-1 from anthropogenic emissions, which are much higher than the previous estimates from regional models.

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

2013-03-01

101

VOC emissions of smouldering combustion from Mediterranean wildfires in central Portugal  

NASA Astrophysics Data System (ADS)

Emissions of trace gases and C5-C10 volatile organic compounds (VOCs) from Mediterranean wildfires occurring in Portugal in summer 2010 were studied. Fire smoke was collected in Tedlar bags and analysed for CO, CO2, total hydrocarbons (THC) and VOCs. The CO, CO2 and THC emission factors (EFs) were 206 ± 79, 1377 ± 142 and 8.1 ± 9 g kg-1 biomass burned (dry basis), respectively. VOC emissions from Mediterranean wildfires were reported for the first time. Aromatic hydrocarbons were major components of the identified VOC emissions. Among them, benzene and toluene were dominant compounds with EFs averaging 0.747 ± 0.303 and 0.567 ± 0.422 g kg-1 biomass burned (dry basis), respectively. Considerable amounts of oxygenated organic volatile compounds (OVOCs) and isoprenoids were detected. 2-Furaldehyde and hexanal were the most abundant measured OVOCs with EFs of 0.337 ± 0.259 and 0.088 ± 0.039 g kg-1 biomass burned (dry basis), respectively. The isoprenoid emissions were dominated by isoprene (EF = 0.207 ± 0.195 g kg-1 dry biomass burned) and ?-pinene (EF = 0.112 ± 0.093 g kg-1 dry biomass burned). Emission data obtained in this work are useful for validating and improving emission inventories, as well for carrying out modelling studies to assess the effects of vegetation fires on air pollution and tropospheric chemistry.

Evtyugina, Margarita; Calvo, Ana Isabel; Nunes, Teresa; Alves, Célia; Fernandes, Ana Patrícia; Tarelho, Luís; Vicente, Ana; Pio, Casimiro

2013-01-01

102

Constraints on the sources and impacts of volatile organic compounds (VOCs) over North America from tall tower measurements  

NASA Astrophysics Data System (ADS)

This dissertation presents the first-ever in-situ tall tower measurements of volatile organic compound (VOC) concentrations. The data span August 2009 through July 2012, and provide new constraints on seasonal and long-term controls on VOC sources and their atmospheric effects. The 200 m sampling height provides a large-scale footprint, while the tall tower location, near the intersection of the main North American ecosystems and at times downwind of the Twin Cities, affords information on natural emissions from some of the most important US landscapes as well as on anthropogenic sources. I interpret the dataset using an atmospheric chemical transport model (GEOS-Chem CTM), with a focus on several key atmospheric VOCs. This dissertation finds that current models underestimate methanol emission rates for younger versus older leaves. This biased seasonality means that the photochemical role for methanol early in the growing season is presently underestimated. A Bayesian inverse analysis of the tall tower observations reveals that the prior estimate of North American anthropogenic acetone sources (based on the US EPA's NEI05 inventory) is accurate to within 20%. However, biogenic acetone emissions from broadleaf trees, shrubs, and herbaceous plants are presently underestimated (˜37%), while emissions from needleleaf trees plus secondary production from biogenic precursors are overestimated by a similar amount (˜40%). Model-measurement comparisons imply that isoprene emissions in the immediate vicinity of the tall tower are accurately captured by the MEGANv2.1 biogenic inventory, but that larger-scale regional emissions are underestimated, reflecting the heterogeneous land cover in this transitional landscape. Isoprene emissions play a key role in seasonal shifts between VOC-limited chemistry in the spring and fall and NOx-limited or transitional chemistry in the summer. A Bayesian inverse analysis based on the tall tower measurements suggests that: i) the RETRO global emission inventory significantly overestimates (> two-fold) US C6-C8 aromatic emissions; ii) the US EPA's NEI08 inventory likewise overestimates the toluene flux by a factor of 3, partly reflecting a bias in the estimated non-road emissions; and iii) total annual emissions of benzene and C8 aromatics in the EPA's NEI08 are accurate to within the analysis uncertainty, but with some seasonal biases for on-road emissions.

Hu, Lu

103

VOC and hazardous air pollutant emission factors for military aircraft fuel cell inspection, maintenance, and repair operations  

SciTech Connect

Accurate emission estimation is one of the key aspects of implementation of any air quality program. The Federal Title 5 program, specially requires an accurate and updated inventory of criteria as well hazardous air pollutants (HAPs) from all facilities. An overestimation of these two categories of pollutants, may cause the facility to be classified as a major source, when in fact it may actually be a minor source, and may also trigger unnecessary compliance requirements. A good example of where overestimation of volatile organic compounds (VOCs) and HAPs is easily possible are military aircraft fuel cells inspection, maintenance, and repair operations. The military aircraft fuel tanks, which are commonly identified as fuel cells, are routinely inspected for maintenance and repairs at military aircraft handling facilities. Prior to entry into the fuel cell by an inspector, fuel cells are first drained into bowsers and then purged with fresh air; the purged air is generally released without any controls to the atmosphere through a stack. The VOC and HAPs emission factors from these operations are not available in the literature for JP-8 fuel, which is being used increasingly by military aircraft. This paper presents two methods for estimating emissions for this source type, which are based on engineering calculations and professional judgment. This paper presents several methods for estimating emissions for this source type, which are based on engineering calculations and professional judgment. There are three emission producing phases during the draining and purging operations: (1) emissions during splash loading of bowsers (unloading of fuel cells), (2) emissions from spillage of fuel during loading of bowsers, and (3) emissions from fuel cell purging operations. Results of the emission estimation, including a comparison of the two emission estimation methods are presented in this paper.

Nand, K.; Sahu, R. [Parsons Engineering Science, Inc., Pasadena, CA (United States)

1997-12-31

104

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...

105

Contrasting responses of silver birch VOC emissions to short- and long-term herbivory.  

PubMed

There is a need to incorporate the effects of herbivore damage into future models of plant volatile organic compound (VOC) emissions at leaf or canopy levels. Short-term (a few seconds to 48 h) changes in shoot VOC emissions of silver birch (Betula pendula Roth) in response to feeding by geometrid moths (Erannis defoliaria Hübner) were monitored online by proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS). In addition, two separate field experiments were established to study the effects of long-term foliage herbivory (FH, 30-32 days of feeding by geometrids Agriopis aurantiaria (Clerck) and E. defoliaria in two consecutive years) and bark herbivory (BH, 21 days of feeding by the pine weevil (Hylobius abietis L.) in the first year) on shoot and rhizosphere VOC emissions of three silver birch genotypes (gt14, gt15 and Hausjärvi provenance). Online monitoring of VOCs emitted from foliage damaged by geometrid larvae showed rapid bursts of green leaf volatiles (GLVs) immediately after feeding activity, whereas terpenoid emissions had a tendency to gradually increase during the monitoring period. Long-term FH caused transient increases in total monoterpene (MT) emissions from gt14 and sesquiterpene (SQT) emissions from Hausjärvi provenance, mainly in the last experimental season. In the BH experiment, genotype effects were detected, with gt14 trees having significantly higher total MT emissions compared with other genotypes. Only MTs were detected in the rhizosphere samples of both field experiments, but their emission rates were unaffected by genotype or herbivory. The results suggest that silver birch shows a rapid VOC emission response to short-term foliage herbivory, whereas the response to long-term foliage herbivory and bark herbivory is less pronounced and variable at different time points. PMID:24627262

Maja, Mengistu M; Kasurinen, Anne; Yli-Pirilä, Pasi; Joutsensaari, Jorma; Klemola, Tero; Holopainen, Toini; Holopainen, Jarmo K

2014-03-01

106

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.

107

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

108

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

EPA Science Inventory

The report describes the development of a model for estimating emissions of volatile organic compounds (VOCs) from petroleum refineries and synfuel plants. The model, responding to a need to define a consistent and comprehensive approach for estimating VOC emissions from these tw...

109

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

EPA Science Inventory

The report describes the development of a model for estimating emissions of volatile organic compounds (VOCs) from petroleum refineries and synfuel plants. The model, responding to a need to define a consistent and comprehensive approach for estimating VOC emissions from these tw...

110

CAPSTONE REPORT ON THE DEVELOPMENT OF A STANDARD TEST METHOD FOR VOC EMISSIONS FROM INTERIOR LATEX AND ALKYD PAINTS  

EPA Science Inventory

This document provides a detailed report on the small-chamber test method developed by EPA/NRMRL for characterizing volatile organic compound (VOC) emissions from interior latex and alkyd paints. Current knowledge about VOC, including hazardous air pollutant, emissions fr...

111

CAPSTONE REPORT ON THE DEVELOPMENT OF A STANDARD TEST METHOD FOR VOC EMISSIONS FROM INTERIOR LATEX AND ALKYD PAINTS  

EPA Science Inventory

The report gives details of a small-chamber test method, developed by EPA for characterizing volatile organic compound (VOC) emissions from inte-rior latex and alkyd paints. Current knowledge about VOC, including haz-ardous air pollutant, emissions from in-terior paints generated...

112

CAPSTONE REPORT ON THE DEVELOPMENT OF A STANDARD TEST METHOD FOR VOC EMISSIONS FROM INTERIOR LATEX PAINT AND ALKYD PAINTS  

EPA Science Inventory

The report gives details of a small-chamber test method developed by the EPA for characterizing volatile organic compound (VOC) emissions from interior latex and alkyd paints. Current knowledge about VOC, including hazardous air pollutant, emissions from interior paints generated...

113

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

114

Sensory and chemical characterization of VOC emissions from building products: impact of concentration and air velocity  

NASA Astrophysics Data System (ADS)

The emissions from five commonly used building products were studied in small-scale test chambers over a period of 50 days. The odor intensity was assessed by a sensory panel and the concentrations of selected volatile organic compounds (VOCs) of concern for the indoor air quality were measured. The building products were three floor coverings: PVC, floor varnish on beechwood parquet and nylon carpet on a latex foam backing; an acrylic sealant, and a waterborne wall paint on gypsum board. The impacts of the VOC concentration in the air and the air velocity over the building products on the odor intensity and on the emission rate of VOCs were studied. The emission from each building product was studied under two or three different area-specific ventilation rates, i.e. different ratios of ventilation rate of the test chamber and building product area in the test chamber. The air velocity over the building product samples was adjusted to different levels between 0.1 and 0.3 m s -1. The origin of the emitted VOCs was assessed in order to distinguish between primary and secondary emissions. The results show that it is reasonable after an initial period of up to 14 days to consider the emission rate of VOCs of primary origin from most building products as being independent of the concentration and of the air velocity. However, if the building product surface is sensitive to oxidative degradation, increased air velocity may result in increased secondary emissions. The odor intensity of the emissions from the building products only decayed modestly over time. Consequently, it is recommended to use building products which have a low impact on the perceived air quality from the moment they are applied. The odor indices (i.e. concentration divided by odor threshold) of primary VOCs decayed markedly faster than the corresponding odor intensities. This indicates that the secondary emissions rather than the primary emissions, are likely to affect the perceived air quality in the long run. Some of the building products continued to affect the perceived air quality despite the concentrations of the selected VOCs resulted in odor indices less than 0.1. Therefore, odor indices less than 0.1 as an accept criterion cannot guarantee that a building product has no impact on the perceived air quality.

Knudsen, H. N.; Kjaer, U. D.; Nielsen, P. A.; Wolkoff, P.

115

A framework and experimental study of an improved VOC/formaldehyde emission reference for environmental chamber tests  

NASA Astrophysics Data System (ADS)

Environmental chamber systems are usually employed in the testing of volatile organic compound (VOC) and formaldehyde emissions from building materials. The measurement accuracy of environmental chamber systems can be evaluated by VOC/formaldehyde emission references. However, the available VOC/formaldehyde emission references all have some limitations for applications to various scales of chambers. A framework for designing and using a target VOC/formaldehyde emission references to evaluate the performance of chamber systems for measuring VOC/formaldehyde emissions from building materials is studied. Liquid-inner tube diffusion-film-emission (LIFE) reference is improved in this study to meet the requirements of a target VOC/formaldehyde emission reference, such as reliability, similarity as building materials, efficiency for measurement. Equivalent emission characteristic parameters are designed for a toluene LIFE reference to perform similar to a building material. Chamber test of the LIFE reference is made in a 30 m3 stainless steel ventilated environmental chamber at 23 ± 1 °C and 50 ± 5% relative humidity. The experimental data match the predictions using LIFE emission model as well as building material emission model. The improvement of the LIFE reference enables its application for the evaluation of the performance of all kinds of environmental chambers as a general reference in tests of VOCs/formaldehyde emissions from building materials.

Wei, Wenjuan; Xiong, Jianyin; Zhao, Weiping; Zhang, Yinping

2014-01-01

116

Economic impact of incorporating RACT 1 guidelines for VOC emissions into the Illinois air pollution control regulations, R78-3 and R78-4. Final report  

Microsoft Academic Search

In order to reduce ambient ozone concentration and achieve the NAAQS, the U.S. Environmental Protection Agency has developed guidelines from the control of volatile organic compounds (VOC) emissions from stationary sources. These guidelines reflect EPA's judgment of what constitutes reasonably available control technology (RACT). The RACT guidelines were developed to aid states in revising their state implementation plans to achieve

J. J. Yates; R. K. Chaudhry; D. P. Kuhaneck; A. Kleinrath; W. H. Hallenbeck

1979-01-01

117

Measurements of volatile organic compound (VOC) emissions from wood stains using an electronic balance  

SciTech Connect

An emissions test method using an electronic balance is introduced for measuring the TVOC emission rates of oil-based wood stains, with a detailed procedure for preparing test specimens. The emission characteristics of volatile organic compounds (VOC) from an artificial wood stain and an oil-based commercial wood stain were determined. Results showed that VOC emissions from both stains included a surface evaporation and an internal diffusion sub-process. With regard to time, the entire emission period could be divided into three periods: (1) an initial evaporation-controlled period that was characterized by a high and fast decaying emission rate, (2) a transition period (following the initial period) in which the emissions transited from an evaporation-controlled to an internal diffusion-controlled process, and (3) an internal diffusion-controlled period that was characterized by a low and slowly decaying emission rate. For the commercial wood stain tested, the length of the initial period was approximately three hours, and about 46% of the emittable VOC mass was emitted during this short period. The transition period was between 3 and 6.5 hours from the start of testing and only accounted for about 4% of VOC mass emitted. The rest (about 50%) of the VOC mass was emitted in the diffusion-controlled period over a long period of time. Comparison between the commercial wood stain and an artificial wood stain suggested that the pigments/solids in the wood stain had significant effect on the time scales and amount of mass emitted during each emission period. The presence of additional VOCs in the commercial wood stain might have also affected the emission profiles. These results are useful for developing better models for predicting the emission rates. The electronic balance method was also compared with those determined from the TVOC concentrations measured at the chamber exhaust (referred to as chamber method). Results show that the two methods agreed well with each other, confirming the validity of the complete mixing assumption that is often used in environmental chamber testing. These results are useful for developing standard test protocols for testing wet building materials such as wood stains, varnishes, and paints.

Zhang, J.S.; Nong, G.; Shaw, C.Y.; Wang, J.

1999-07-01

118

ENVIRONMENTAL REGULATIONS AND TECHNOLOGY - FUGITIVE VOC EMISSIONS IN THE SYNTHETIC ORGANIC CHEMICALS MANUFACTURING INDUSTRY  

EPA Science Inventory

This 29 - page Technology Transfer Environmental Regulations and Technology publication is intended as an introduction to the Synthetic Organic Chemicals Manufacturing Industry (SOCMI) ugitive VOC emissions standards. he Clean Air Act, as amended in 1977, directed he U.S. Environ...

119

SUMMARY OF JOINT DOD, EPA RESEARCH TO CONTROL VOC AND TOXIC EMISSIONS  

EPA Science Inventory

The paper summarizes the results of joint projects conducted during last 6 years by the Department of Defense and EPA to control volatile organic compounds (VOCs) and toxic emissions. ajor emphasis has been on product coating and metal finishing: (1) paint stripping using plastic...

120

Human exposure to VOCs in indoor air: Combined effects of source and sink kinetics  

SciTech Connect

The use of models to predict human exposure to volatile organic compounds (VOCs) is an important step in the risk-based corrective action (RBCA) process, i.e., to decide whether and how much a site must be remediated to reduce human health risks to acceptable levels. Models used in the RBCA process are generally characterized by several simplifying assumptions: spatial homogeneity of concentrations within the entire indoor atmosphere, complete stripping from sources of volatilization, steady-state conditions, and inert surfaces. To address these limitations, a new model has been developed which can treat any number of building compartments with prescribed inter-zonal connectivity. The model incorporates source terms associated with soil vapor intrusion and volatilization of chemicals from contaminated water. As such, the model is capable of addressing continuous sources (vapor intrusion) as well as discrete source events associated with water usage. Finally, the model accounts for the effects of adsorptive sinks on short-term reductions in gas-phase concentrations, as well as prolonged chemical retention due to slow desorption rates. Model results illustrate the impact and differences of short-term volatilization events associated with intermittent water uses and continuous source emissions associated with soil vapor intrusion. Results also illustrate the effects of mass transfer limitations and indoor sinks on indoor air concentrations and resulting human exposure.

Won, D.; Howard, C.; Corsi, R.L. [Univ. of Texas, Austin, TX (United States). Dept. of Civil Engineering

1998-12-31

121

Eddy covariance VOC emission and deposition fluxes above grassland using PTR-TOF  

PubMed Central

Eddy covariance (EC) is the preferable technique for flux measurements since it is the only direct flux determination method. It requires a continuum of high time resolution measurements (e.g. 5-20 Hz). For volatile organic compounds (VOC) soft ionization via proton transfer reaction has proven to be a quantitative method for real time mass spectrometry; here we use a proton transfer reaction time of flight mass spectrometer (PTR-TOF) for 10 Hz EC measurements of full mass spectra up to m/z 315. The mass resolution of the PTR-TOF enabled the identification of chemical formulas and separation of oxygenated and hydrocarbon species exhibiting the same nominal mass. We determined 481 ion mass peaks from ambient air concentration above a managed, temperate mountain grassland in Neustift, Stubai Valley, Austria. During harvesting we found significant fluxes of 18 compounds distributed over 43 ions, including protonated parent compounds, as well as their isotopes and fragments and VOC-H+ – water clusters. The dominant BVOC fluxes were methanol, acetaldehyde, ethanol, hexenal and other C6 leaf wound compounds, acetone, acetic acid, monoterpenes and sequiterpenes. The smallest reliable fluxes we determined were less than 0.1 nmol m?2 s?1, as in the case of sesquiterpene emissions from freshly cut grass. Terpenoids, including mono- and sesquiterpenes, were also deposited to the grassland before and after the harvesting. During cutting, total VOC emission fluxes up to 200 nmolC m?2 s?1 were measured. Methanol emissions accounted for half of the emissions of oxygenated VOCs and a third of the carbon of all measured VOC emissions during harvesting. PMID:24348524

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

2013-01-01

122

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

123

Spatial\\/Temporal Variations and Source Apportionment of VOCs Monitored at Community Scale in an Urban Area  

Microsoft Academic Search

pThis study aimed to characterize spatial\\/temporal variations of ambient volatile organic compounds (VOCs) using a community-scale monitoring approach and identify the main sources of concern in Paterson, NJ, an urban area with mixed sources of VOCs. VOC samples were simultaneously collected from three local source-dominated (i.e., commercial, industrial, and mobile) sites in Paterson and one background site in Chester, NJ

Chang Ho Yu; Xianlei Zhu; Zhi-hua Fan

2014-01-01

124

Impacts of simulated herbivory on VOC emission profiles from coniferous plants  

NASA Astrophysics Data System (ADS)

The largest global source of volatile organic compounds (VOCs) in the atmosphere is from biogenic emissions. Plant stressors associated with a changing environment can alter both the quantity and composition of the compounds that are emitted. This study investigated the effects of one global change stressor, increased herbivory, on plant emissions from five different coniferous species: bristlecone pine (Pinus aristata), blue spruce (Picea pungens), western redcedar (Thuja plicata), grand fir (Abies grandis), and Douglas-fir (Pseudotsugas menziesii). Herbivory was simulated in the laboratory via exogenous application of methyl jasmonate, an herbivory proxy. Gas-phase species were measured continuously with a gas chromatograph coupled to a mass spectrometer and flame ionization detector (GC-MS-FID). Stress responses varied between the different plant types and even between experiments using the same set of saplings. The compounds most frequently impacted by the stress treatment were alpha-pinene, beta-pinene, 1,8-cineol, beta-myrcene, terpinolene, limonene, and the cymene isomers. Individual compounds within a single experiment often exhibited a different response to the treatment from one another.

Faiola, C. L.; Jobson, B. T.; VanReken, T. M.

2014-09-01

125

40 CFR Table 1 to Subpart Jjjj of... - NOX, CO, and VOC Emission Standards for Stationary Non-Emergency SI Engines ?100 HP (Except...  

Code of Federal Regulations, 2011 CFR

... , CO, and VOC Emission Standards for Stationary...100 HP (Except Gasoline and Rich Burn... , CO, and VOC Emission Standards for Stationary...100 HP (Except Gasoline and Rich Burn... , CO, and VOC Emission Standards for Stationary...100 HP (Except Gasoline and Rich...

2011-07-01

126

Comparison of gasoline and methanol vehicle emissions using VOC reactivity  

Microsoft Academic Search

This paper compares the mass, composition and reactivity towards ozone formation of gasoline and methanol vehicle emissions. Methods used to estimate ozone forming potential include published reactivity scales and the EPA-OZIPM model. Evaluation of the available vehicle emission measurement data does not indicate any ozone benefit for methanol. The data show a wide range in the reactivity of gasoline vehicle

C. H. Schleyer; W. J. Koehl

1990-01-01

127

APPORTIONMENT OF RESIDENTIAL INDOOR VOCS AND ALDEHYDES TO INDOOR AND OUTDOOR SOURCES IN ROANOKE  

EPA Science Inventory

The average concentrations of a large number of VOC and aldehyde species measured in ten Roanoke, Virginia residences in wintertime have been apportioned according to their contributions from all inside sources and all outside sources. he two category apportionment was accomplish...

128

Uptake and emission of VOCs near ground level below a mixed forest at Borden, Ontario  

NASA Astrophysics Data System (ADS)

Understanding of the atmosphere/forest canopy exchange of volatile organic compounds (VOCs) requires insight into the deposition, emission, and chemical reactions of VOCs below the canopy. Between 18 July and 9 August 2009, VOCs were measured with proton-transfer-reaction mass spectrometry (PTR-MS) at six heights between 1 and 6 m beneath a 23 m high mixed-forest canopy. Measured VOCs included methanol, isoprene, acetone, methacrolein and methyl vinyl ketone (MACR + MVK), monoterpenes, and sesquiterpenes. There are pronounced differences in the behaviour of isoprene and its by-products and that of the terpenes. Non-terpene mixing ratios increase with height, suggesting predominantly downward fluxes. In contrast, the terpene mixing ratios decrease with height, suggesting upward fluxes. A 1-D canopy model was used to compare results to measurements with and without surface deposition of isoprene and MACR + MVK and emissions of monoterpenes and sesquiterpenes. Results suggest deposition velocities of 2.7 mm s-1 for isoprene and 1.2 mm s-1 for MACR + MVK and daytime surface emission rates of 63 ?g m-2 h-1 for monoterpenes. The modelled isoprene surface deposition is approximately 2% of the canopy-top isoprene emissions and the modelled emissions of monoterpenes comprise approximately 15 to 27% of the canopy-top monoterpene emissions to the atmosphere. These results suggest that surface monoterpene emissions are significant for forest canopy/atmosphere exchange for this mixed-forest location and surface uptake is relatively small for all the species measured in this study.

Gordon, M.; Vlasenko, A.; Staebler, R. M.; Stroud, C.; Makar, P. A.; Liggio, J.; Li, S.-M.; Brown, S.

2014-09-01

129

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...

130

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 ...

131

Challenges in using flux chambers to measure ammonia and VOC emissions from open feedlot pen surfaces and retention ponds  

Technology Transfer Automated Retrieval System (TEKTRAN)

Few methodologies currently available to estimate ammonia and volatile organic compound (VOC) emissions from livestock operations have been adequately validated for accuracy. Flow-through flux chambers and wind tunnels are sometimes used; however, ammonia and VOC flux from pen or pond surfaces are a...

132

Characterization of VOC Emissions from Various Components of Dairy Farming and their effect on San Joaquin Valley Air Quality  

NASA Astrophysics Data System (ADS)

The San Joaquin Valley Air Basin in Central California is classified by the U.S. Environmental Protection Agency (EPA) as a serious non-attainment area for health-based eight-hour federal ozone (smog) standard (1). In August 2005, the San Joaquin Valley Air Pollution Control District issued a report identifying dairies as a main source of Volatile Organic Compounds (VOCs) and fine particulate matter in the valley (2). Among these compounds, we have found that ethanol, methanol, acetone and acetaldehyde are produced in major quantities throughout the San Joaquin valley as by-products of yeast fermentation of silage and photochemical oxidation. These oxygenates, especially ethanol, play an important role in ozone (O3) formation within the valley. Three different types of sampling protocols were employed in order to determine the degree of enhancement of the four oxygenates in the valley air shed, as well as to determine their sources, emission profiles and emission rates. An assessment of the emissions of these oxygenates in the valley was achieved using data obtained on low altitude flights through the valley and from ground level samples collected thoughout the valley. The photochemical production of ozone was calculated for each of the four oxygenates and approximately one hundred other quantified VOCs. Based on the Maximum Incremental Reactivity (MIR) scale and concentrations of each oxygenate in the atmosphere, as much as 20% of O3 production in the valley is from ethanol and its photochemical by-product acetaldehyde. Our findings suggest that improvement to the valley air quality may be obtained by focusing on instituting new silage containment practices and regulations. 1. Lindberg, J. "Analysis of the San Joaquin Valley 2007 Ozone Plan." State of California Air Resources Board. Final Draft Staff Report. 5/30/2007. 2. Crow, D., executive director/APCO. "Air Pollution Control Officer's Determination of VOC Emisison Factors for Dairies." San Joaquin Valley Air Pollution Control District. Aug. 1st 2005.

Yang, M. M.; Meinardi, S.; Krauter, C.; Blake, D.

2008-12-01

133

Needle removal by pine sawfly larvae increases branch-level VOC emissions and reduces below-ground emissions of Scots pine.  

PubMed

Climate warming is expected to increase the frequency of insect outbreaks in Boreal conifer forests. We evaluated how needle removal by the larvae of two diprionid sawfly species affects the composition and quantity of VOC emissions from Pinus sylvestris L. saplings. Feeding damage significantly increased the rate of localized VOC emissions from the damaged branch. The emissions of total monoterpenes (MTs) were dominating (96-98% of total VOCs) and increased by14-fold in Neodiprion sertifer-damaged branches and by 16-fold in Diprion pini-damaged branches compared to intact branches. Emissions of ?-3-carene, ?-pinene, sabinene, and ?-phellandrene were most responsive. Feeding damage by N. sertifer larvae increased the emission rates of total sesquiterpenes by 7-fold (4% of total VOCs) and total green leaf volatiles by 13-fold (<1% of total VOCs). The VOC emissions from N. sertifer larvae constituted nearly 25% of the total branch emissions. N. sertifer feeding in the lower branches induced 4-fold increase in MT emissions in the top crown. Defoliation of Scots pine by D. pini significantly reduced the below-ground emissions of total MTs by approximately 80%. We conclude that defoliators could significantly increase total VOC emissions from the Scots pine canopy including MT emissions from resin storing sawfly larvae. PMID:23586621

Ghimire, Rajendra P; Markkanen, Juha M; Kivimäenpää, Minna; Lyytikäinen-Saarenmaa, Päivi; Holopainen, Jarmo K

2013-05-01

134

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

PubMed Central

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

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

2014-01-01

135

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

PubMed

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

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

2014-04-01

136

Developing a Consistent Methodology to Calculate VOC and HAP Evaporative Emissions for Stage I and Stage II Operations at Gasoline Service Stations for the 1999 NEI (DRAFT V2.0)  

Microsoft Academic Search

Pacific Environmental Services, Inc. (PES) recently assisted Mr. Ron Ryan (US EPA) and the Emission Inventory and Improvement Program's (EIIP) Area Source Committee in analyzing the VOC emissions data provided in the 1999 National Emission Inventory (NEI) (draft v2.0) for Stage I and Stage II Operations at gasoline service stations. The analysis consisted of reviewing and summarizing the reported gasoline

Glenn Tracy Johnson

137

Importance of Biotic vs Abiotic Controls on VOC Emissions from Ponderosa Pine  

NASA Astrophysics Data System (ADS)

The emissions of VOCs, including monoterpenes (MTs) and 2-methyl-3-buten-2-ol (MBO), from ponderosa pine can be important contributors to the regional production of ozone and secondary organic aerosols in the Western United States. The goal of this study was to better characterize the influences of biotic and abiotic factors on the emissions of these compounds. Using PTR-MS coupled with measurements of photosynthesis and stomatal conductance (gs) we generated light and temperature curves from intact needles of mature ponderosa pine trees and used abscisic acid (ABA) to reduce gs and photosynthesis under constant light and temperature conditions. Stomatal conductance and photosynthesis were almost perfectly correlated during all our measurements, so we were unable to separate their influences. We found that increasing temperature by 10 oC increased emissions of both MTs and MBO by 80-120% even though gs and photosynthesis were reduced by ~50%. Light curves performed at 30 oC showed that gs and photosynthesis exhibited a strong control over MT and MBO emissions although the effect was more pronounced for MBO than MT emissions. In most cases a 60% reduction in gs and photosynthesis caused a ~50% reduction in MBO emissions and a 5-20% reduction in MT emissions. Using ABA we were able to induce stomatal closure while maintaining a constant light and temperature environment and we found that stomatal closure due to ABA caused declines in MT and MBO emissions that were similar in magnitude to those seen in the light curves. When compared at the same light and temperature conditions, individuals with lower gs and photosynthesis did not necessarily have lower emissions than those with higher gs and photosynthesis, indicating that gs and photosynthesis may not be good predictors of emissions between individuals, but within each individual the instantaneous changes in gs and photosynthesis did appear to exert control over the emissions of VOCs. These data show that plant physiology is an important constraint in regulating the instantaneous emissions of VOCs, but also that the relationships are modified by external temperature, probably through the increased volatility of the VOCs.

Eller, A. S.; Harley, P. C.; Monson, R. K.

2011-12-01

138

Investigation of the emissions and profiles of a wide range of VOCs during the Clean air for London project  

NASA Astrophysics Data System (ADS)

The majority of the World's population live in polluted urbanized areas. Poor air quality is shortening life expectancy of people in the UK by an average 7-8 months and costs society around £20 billion per year.[1] Despite this, our understanding of atmospheric processing in urban environments and its effect on air quality is incomplete. Air quality models are used to predict how air quality changes given different concentrations of pollution precursors, such as volatile organic compounds (VOCs). The urban environment of megacities pose a unique challenge for air quality measurements and modelling, due to high population densities, pollution levels and complex infrastructure. For over 60 years the air quality in London has been monitored, however the existing measurements are limited to a small group of compounds. In order to fully understand the chemical and physical processes that occur in London, more intensive and comprehensive measurements should be made. The Clean air for London (ClearfLo) project was conducted to investigate the air quality, in particular the boundary layer pollution, of London. A relatively new technique, comprehensive two dimensional gas chromatography (GC×GC) [2] was combined with a well-established dual channel GC (DC-GC) [3] system to provide a more comprehensive measurement of VOCs. A total of 78 individual VOCs (36 aliphatics, 19 monoaromatics, 21 oxygenated and 2 halogenated) and 10 groups of VOCs (8 aliphatic, 1 monoaromatic and 1 monoterpene) from C1-C13+ were quantified. Seasonal and diurnal profiles of these VOCs have been found which show the influence of emission source and chemical processing. Including these extra VOCs should enhance the prediction capability of air quality models thus informing policy makers on how to potentially improve air quality in megacities. References 1. House of Commons Environmental Audit Committee, Air Quality: A follow-up report, Ninth Report of session 2012-12. 2. Lidster, R.T., J.F. Hamilton, and A.C. Lewis, The application of two total transfer valve modulators for comprehensive two-dimensional gas chromatography of volatile organic compounds. Journal of Separation Science, 2011. 34(7): p. 812-821. 3. Hopkins, J.R., C.E. Jones, and A.C. Lewis, A dual channel gas chromatograph for atmospheric analysis of volatile organic compounds including oxygenated and monoterpene compounds. Journal of Environmental Monitoring, 2011. 13(8): p. 2268-2276.

Holmes, Rachel; Lidster, Richard; Hamilton, Jacqueline; Lee, James; Hopkins, James; Whalley, Lisa; Lewis, Alistair

2014-05-01

139

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

140

Application of horizontal spiral coil heat exchanger for volatile organic compounds (VOC) emission control.  

PubMed

The petroleum products have wide range of volatility and are required to be stored in bulk. The evaporation losses are significant and it is a economic as well as environmental concern, since evaporative losses of petroleum products cause increased VOC in ambient air. Control of these losses poses a major problem for the storage tank designers. Ever rising cost of petroleum products further adds to the gravity of the problem. Condensation is one of the technologies for reducing volatile organic compounds emissions. Condensation is effected by condenser, which is basically a heat exchanger and the heat exchanger configuration plays an important role. The horizontal spiral coil heat exchanger is a promising configuration that finds an application in VOC control. This paper attempts to understand underlying causes of emissions and analyse the option of horizontal spiral coil heat exchanger as vent condenser. PMID:25464701

Deshpande, P M; Dawande, S D

2013-04-01

141

Application of horizontal spiral coil heat exchanger for volatile organic compounds (VOC) emission control.  

PubMed

The petroleum products have wide range of volatility and are required to be stored in bulk. The evaporation losses are significant and it is a economic as well as environmental concern, since evaporative losses of petroleum products cause increased VOC in ambient air. Control of these losses poses a major problem for the storage tank designers. Ever rising cost of petroleum products further adds to the gravity of the problem. Condensation is one of the technologies for reducing volatile organic compounds emissions. Condensation is effected by condenser, which is basically a heat exchanger and the heat exchanger configuration plays an important role. The horizontal spiral coil heat exchanger is a promising configuration that finds an application in VOC control. This paper attempts to understand underlying causes of emissions and analyse the option of horizontal spiral coil heat exchanger as vent condenser. PMID:25508332

Deshpande, P M; Dawande, S D

2013-04-01

142

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

143

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...

144

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

145

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

146

The Amazonian Floodplains, an ecotype with challenging questions on volatile organic compound (VOC) emissions  

NASA Astrophysics Data System (ADS)

Volatile organic compound (VOC) emissions are affected by a variety of biotic and abiotic factors such as light intensity, temperature, CO2 and drought. Another factor usually overlooked but very important for the tropical rainforest in Amazonia is regular flooding. According to recent estimates, the total Amazonian floodplain area easily ranges up to 700,000 km^2, including whitewater river floodplains (várzea) blackwater regions (igapó) and further clearwater regions. Regarding the total Amazonian wetlands the area sums up to more than 2.000.000 km^2, i.e. 30% of Amazonia. To survive the flooding periods causing anoxic conditions for the root system of up to several months, vegetation has developed several morphological, anatomical and physiological strategies. One is to switch over the root metabolism to fermentation, thus producing ethanol as one of the main products. Ethanol is a toxic metabolite which is transported into the leaves by the transpiration stream. From there it can either be directly emitted into the atmosphere, or can be re-metabolized to acetaldehyde and/or acetate. All of these compounds are volatile enough to be partly released into the atmosphere. We observed emissions of ethanol, acetaldehyde and acetic acid under root anoxia. Furthermore, plant stress induced by flooding also affected leaf primary physiological processes as well as other VOC emissions such as the release of isoprenoids and other volatiles. For example, Hevea spruceana could be identified as a monoterpene emitting tree species behaving differently upon anoxia depending on the origin, with increasing emissions of the species from igapó and decreasing with the corresponding species from várzea. Contrasting such short term inundations, studies of VOC emissions under long term conditions (2-3 months) did not confirm the ethanol/acetaldehyde emissions, whereas emissions of other VOC species decreased considerably. These results demonstrate that the transfer of our knowledge based on short-term experiments is risky being transferred to an ecotype which is governed under natural conditions by long term flooding. Furthermore, contrasting such experiments with usually young trees (saplings or a few years old) nothing is known about the emission behavior of adult trees under field conditions.

Kesselmeier, J.

2012-12-01

147

Titania-catalyzed photooxidative control of airborne emissions containing nitroglycercine and VOCs  

SciTech Connect

This paper describes a method for the titania-catalyzed photo-oxidation and treatment of airborne volatile organic compounds (VOCs) containing hazardous levels of nitrolycerine (NG). Emissions from the multibase propellant production processes typically contain VOCs (ethanol and acetone) and NG at 100s and few ppmv levels, respectively. A series of photocatalytic experiments was conducted in a laminar flow reactor that employed Degussa P25{reg_sign} titania as catalyst. A low-pressure mercury resonance lamp provided ultraviolet (UV) radiation for the photoexcitation of the catalyst. Photocatalytic destruction of NG, acetone and ethanol was possible even in absence of added oxygen. In the presence if air, however, the destruction efficiencies increased significantly. The data indicated that under certain reaction conditions, it is possible to completely, photocatalytically, decompose NG, while leaving acetone and large portions of ethanol unconverted. The selective destruction of organic constituents in the waste stream can be desirable in applications involving solvent recovery.

T-Raissi, A.; Muradov, N.Z. [Florida Solar Energy Center, Cape Canaveral, FL (United States)

1993-12-31

148

BTEX and other VOC emissions from a natural gas amine treater. Topical report, February 1996  

SciTech Connect

The report presents the results of a laboratory and field study conducted under Gas Research Institute (GRI) sponsorship to measure the pickup and distribution of benzene, toluene, ethylbenzene, and xylene (BTEX) and other volatile organic compounds (VOC) to the various internal process and emssion streams in a commercial amine treater used to remove acid gas compounds (primarily hydrogen sulfide and carbon dioxide) from natural gas. A laboratory study was conducted to evaluate an analytical technique for quantifying in diethanolamine (DEA) solutions. The accuracy and precision of the technique as well a method detection limit study were carried out. In the field study, samples of the inlet natural gas, flash gas, and regenerator vent gas, lean amine, and rich amine from various locations downstream of the absorber were collected and analyzed. The results were used to determine regenerator vent emission rates and the distribution of BTEX and other VOC around the flash tank.

Skinner, F.D.; Reif, D.L.; Wilson, A.C.

1996-02-01

149

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

150

Long-term variations in natural, terrestrial VOC emissions: 1000-1990 AD  

NASA Astrophysics Data System (ADS)

Natural vegetation emits large amounts of volatile organic compounds (e.g. monoterpenes and isoprene) into the atmosphere. Estimates of the total global source of biogenic volatile organic compounds (BVOCs) in the past millennium range between 1050 and 1100 Tg yr-1 (Adams et al. 2001). BVOCs have multiple impacts on atmospheric chemistry, for example they are believed to affect ozone formation, decrease the oxidizing capacity of the troposphere and substantially alter the concentrations of tropospheric aerosol in continental regions (Seinfeld et al., 1998). Organic compounds constitute 20-90% of the submicron aerosol mass, depending on location. Most of this contribution is secondary, meaning that the emitted VOCs are oxidized in the atmosphere followed by gas-to-particle conversion of the oxidation products (Jimenez et al., 2009). BVOCs emitted by vegetation are the dominant source of secondary organic aerosol (SOA) in the atmosphere (Guenther et al., 1995). Estimates on the present-day organic aerosol budgets are improving rapidly, but it is unclear how the organic aerosol fraction has evolved in the past. Such information is, however, needed for accurate estimates on the climate forcing caused by aerosols. Understanding the factors that have governed BVOC emissions in the past is a prerequisite for completing this task. We evaluate the variability of global fluxes of isoprene, monoterpenes and sesquiterpenes over the last millennium using the Model of Emissions of Gases and Aerosols from Nature (MEGAN) (Guenther et al., 2006). MEGAN estimates the emission activity of BVOCs using meteorological (Air temperature, solar radiation, soil moisture) and landcover (Plant Functional Types (PFTs) and Leaf Area Index (LAI)) inputs. The model is driven off-line using meteorological fields from existing Max Planck Institute Earth System Model (MPI-ESM) (Jungclaus et al. 2010) millennium simulations, and reconstructions of the global changes PFTs and LAI (Kaplan et al., 2010). We evaluate the long-term response of terrestrial BVOC emission activity to variations in land-use change and climatic factors, and find that compared to preindustrial times (1000-1800 A.D.), global isoprene emissions have decreased 8%, monoterpenes emissions have increased 10% and sesquiterpenes emissions have increased 15% during the time period 1950-1990 A.D.. The results suggest that the variation of isoprene emissions is governed by land-use changes, while monoterpenenes and sesquiterpenes variations are dominated by climate variability. Adams, J.M. (2001). Chemosphere - Global Change Science, 3, 73-91 J.H. Seinfeld and S. N. Pandis. (1998). Atmospheric Chemistry and Physics . Wiley, New York Jimenez, J. L. et al. (2009). Science, 326, 1525-1529 Kaplan, J. O. et al (2010). The Holocene 21(5), 775-791 Guenther, A. et al. (1995). J. Geophys. Res., 100, 8873-8892 Hoyle, C. R. et al. (2011). Atmos. Chem. Phys., 11, 321-343 A. Guenther et al. (2006). Atmospheric Chemistry and Physics, 6:3181-3210 J. H. Jungclaus et al. (2010). Climate of the Past, 6:723-737

Acosta, J. C.; Struthers, H.; Zorita, E.; Ekman, A. M.; Riipinen, I.

2012-12-01

151

Spatial and seasonal variation and source apportionment of volatile organic compounds (VOCs) in a heavily industrialized region  

NASA Astrophysics Data System (ADS)

Source apportionment is generally applied to a time series of pollutant concentrations measured at a single site. However, in a complex airshed having multiple pollutant sources, it may be helpful to collect samples from several sites to ensure that some of them have low contributions from specific sources. Ambient air samples (n = 160) were collected by passive sampling during four seasons in 2009 and 2010 at forty different sites in Aliaga, Turkey to determine the spatial, seasonal variations and possible sources of volatile organic compounds (VOCs). Fifty-eight VOCs (?58VOC) were detected. ?58VOC concentrations ranged between 0.1 and 1770 ?g m-3 (avg ± SD, 67 ± 193 ?g m-3). Aliphatic hydrocarbons were generally predominant with a high percentage of contribution (31%-88%) at all sites. Aromatic VOCs were the second highest group (8-50%), followed by halogenated VOCs (1-24%) and oxygenated VOCs (0.04-5.9%). Highly variable spatial distribution of ambient VOC concentrations suggested that the major sources in this region were industrial plants. Generally, VOC concentrations were higher in summer than in winter probably due to increased volatilization from their sources at higher ambient temperatures. However, high atmospheric VOC concentrations were also observed in winter and fall near the petroleum refinery and petrochemical complex, probably due to the calm conditions and high atmospheric stability that is commonly encountered during the winter months in the area, restricting the dilution of pollutants. The newest version of EPA PMF (V5.0) (Positive Matrix Factorization) having the capability of handling multiple site data was used for source apportionment. Refinery and petroleum products, petrochemical industry, solvent use and industrial processes, and vehicle exhaust were the identified VOC sources in the study area, contributing 56%, 22%, 12%, and 10%, respectively to the ?58VOC concentrations. Carcinogenic risks due to lifetime exposure to seven VOCs were also estimated. Estimated risks were the highest for 1,2-dichloroethane, followed by benzene, chloroform, and carbon tetrachloride. Carcinogenic risks for trichloroethene, 1,1,2-trichloroethane, and bromoform were lower than the general acceptable risk level of 1.0 × 10-6. However, risks for 1,2-dichloroethane, benzene, chloroform, and carbon tetrachloride were substantially higher than the acceptable level. It was concluded that carcinogenic risks may reach considerably high levels for a significant portion of the population living in the study area.

Dumanoglu, Yetkin; Kara, Melik; Altiok, Hasan; Odabasi, Mustafa; Elbir, Tolga; Bayram, Abdurrahman

2014-12-01

152

Modelling VOC source impacts on high ozone episode days observed at a mountain summit in Hong Kong under the influence of mountain-valley breezes  

NASA Astrophysics Data System (ADS)

A top-down approach to evaluate high ozone (O3) formation, attributed to different emission sources, is developed for anti-cyclonic conditions in a region of Hong Kong influenced by meso-scale circulations. A near-explicit photochemical model coupled with the Master Chemical Mechanism (MCMv3.2) is used to investigate the chemical characteristics in the region. Important features have been enhanced in this model including the photolysis rates, simulated by the National Center for Atmospheric Research (NCAR) Tropospheric Ultraviolet and Visible (TUV) Radiation Model, as well as hourly variation of Volatile Organic Compound (VOC) concentration input from on-site sampling. In general, the combined model gives a reasonably good representation of high O3 levels in the region. The model successfully captured a multi-day O3 event in the autumn of 2010. Source apportionment via Positive Matrix Factorization (PMF) was carried out on the sampled VOC data, to determine the major sources in the region. Based on the outcomes of the PMF source apportionment, a sensitivity analysis using the developed photochemical model was conducted and used to estimate O3 reduction under different source removal regimes. Results indicate that vehicular emissions are the dominant VOC source contributing to O3 formation. This study has demonstrated a potentially efficient secondary pollutants control methodology, using a combined field measurements and modelling approach.

Lam, S. H. M.; Saunders, S. M.; Guo, H.; Ling, Z. H.; Jiang, F.; Wang, X. M.; Wang, T. J.

2013-12-01

153

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. ...

154

Volatile organic compounds in the Pearl River Delta: Identification of source regions and recommendations for emission-oriented monitoring strategies  

NASA Astrophysics Data System (ADS)

For the purpose of systematically characterizing the ambient volatile organic compound (VOC) levels and their emission sources in the Pearl River Delta (PRD) of China, a grid study with VOC samples simultaneously taken at 84 sites over the PRD was conducted in summer and winter of 2008 and 2009. Positive Matrix Factorization (PMF) model was applied to identify the major VOC contributing sources and their temporal and spatial variations. Nine sources were identified, with gasoline exhaust, industrial emission and LPG leakage & propellant emission the top three significant sources. They accounted for 23%, 16% and 13% of the ambient VOC levels, respectively. Control measures should be therefore targeted on mitigating the VOC emissions from the traffic-related and industrial-related sources. The total VOC level did not show strong increase from 5 a.m. to 10 a.m. during all the four sampling campaigns, which may result from stronger wind and higher mixing height at 10 a.m. Three hotspot areas with significant VOC contributions were identified by source apportionment analysis: (1) the Pearl River Estuary; (2) an area from Central Dongguan to North Shenzhen; and (3) the Zhuhai-Zhongshan-Jiangmen area. For better characterizing the roles of VOC and NOx in producing the secondary pollutants and to identify specific sources emitting excessive concentrations of precursors, the emission-oriented Photochemical Assessment Monitoring Station (PAMS) network is recommended to be established in the PRD. Three PAMS networks are suggested in correspondence to the three identified hotspot areas.

Yuan, Zibing; Zhong, Liuju; Lau, Alexis Kai Hon; Yu, Jian Zhen; Louie, Peter K. K.

2013-09-01

155

Global Emissions of Terpenoid VOCs from Terrestrial Vegetation in the Last Millennium  

SciTech Connect

We investigated the millennial variability of global BVOC emissions by using two independent numerical models: The Model of Emissions of Gases and Aerosols from Nature (MEGAN), for isoprene, monoterpene and sesquiterpene and Lund-Potsdam-Jena General Ecosystem Simulator (LPJ8 GUESS), for isoprene and monoterpenes. We found the millennial trends of global isoprene emissions to be mostly affected by land cover and atmospheric carbon dioxide changes, whereas monoterpene and sesquiterpene emission were dominated by temperature change. Isoprene emissions declined substantially in regions with large and rapid land cover change. In addition, isoprene emission sensitivity to drought proved to have signicant short term global effects. By the end of the past millennium MEGAN isoprene emissions were 634 TgC yr-1 (13% and 19% less than during during 1750-1850 and 1000- 15 1200, respectively) and LPJ-GUESS emissions were 323 TgC yr-1 (15% and 20% less than during 1750-1850 and 1000-1200, respectively). Monoterpene emissions were 89 TgC yr-1 (10% and 6% higher than during 1750-1850 and 1000-1200, respectively) in MEGAN, and 24 TgC yr-1 (2% higher and 5% 19 20 less than during 1750-1850 and 1000-1200, respectively) in LPJ-GUESS. MEGAN sesquiterpene emissions were 36 TgC yr-1 (10% and 4% higher than during1750-1850 and 1000-1200, respectively). Although both models capture similar We investigated the millennial variability of global BVOC emissions by using two independent numerical models: The Model of Emissions of Gases and Aerosols from Nature (MEGAN), for isoprene, monoterpene and sesquiterpene and Lund-Potsdam-Jena General Ecosystem Simulator (LPJ8GUESS), for isoprene and monoterpenes. We found the millennial trends ofglobal isoprene emissions to be mostly a*ected by land cover and atmospheric carbon dioxide changes, whereas monoterpene and sesquiterpene emission were dominated by temperature change. Isoprene emissions declined substantially in regions with large and rapid land cover change. In addition, isoprene emission sensitivity to drought proved to have signifcant short term global effects. By the end of the past millennium MEGAN isoprene emissions were 634 TgC yr-1 (13% and 19% less than during during 1750-1850 and 1000- 1200, respectively) and LPJ-GUESS emissions were 323 TgC yr-1 (15% and 16 17 20% less than during 1750-1850 and 1000-1200, respectively). Monoterpene emissions were 89 TgC yr-1 (10% and 6% higher than during 1750-1850 and 18 1000-1200, respectively) in MEGAN, and 24 TgC yr-1 (2% higher and 5% less than during 1750-1850 and 1000-1200, respectively) in LPJ-GUESS. MEGAN sesquiterpene emissions were 36 TgC yr-1 (10% and 4% higher than during1750-1850 and 1000-1200, respectively). Although both models capture similar emission trends, the magnitude of the emissions are different. This highlights the importance of building better constraints on VOC emissions from terrestrial vegetation.emission trends, the magnitude of the emissions are different. This highlights the importance of building better constraints on VOC emissions from terrestrial vegetation.

Acosta Navarro, J. C.; Smolander, S.; Struthers, H.; Zorita, E.; Ekman, A. M.; Kaplan, J. O.; Guenther, Alex B.; Arneth, A.; Riipinen, I.

2014-06-16

156

Reduction of VOC emissions from metal dip coating applications -- Canam Steel Corporation Point of Rocks, MD case study  

SciTech Connect

The reduction of VOC emissions from metal dip coating applications is not an environmental constraint, it is an economic opportunity. This case study shows how the industry can reap economic benefits from VOC reductions while improving air quality. The Canam Steel Corporation plant located in Point of Rocks, MD operates dip tanks for primer application on fabricated steel joists and joist girders. This process is presently subject to a regulation that limits the paint VOC content to 3.5 pounds per gallon of coating less water. As a result of the high paint viscosity associated with that regulation, the paint thickness of the dipped steel is thicker than the customers` specifications. Most of the VOC emissions can therefore be associated with the excess of paint applied to the products rather than to the required thickness of the coating. The higher paint usage rate has more than environmental consequences, it increases the cost of the applied coating. The project is to reduce the paint usage by controlling the viscosity of the coating in the tank. Experimental results as well as actual mass balance calculations show that using a higher VOC content paint would reduce the overall VOC emissions. The author explained the project to the Maryland Department of the Environment (MDE) Air and Radiation Management Administration. First, the MDE agreed to develop a new RACT determination for fabricated steel dipping operations. The new regulation would limit the amount of VOC than can be emitted to dip coat a ton of fabricated steel. Second, the MDE agreed to allow experimentation of the higher VOC content paint as a pilot project for the new regulation. This paper demonstrates the need for a RACT determination specific to fabricated steel dipping operations.

Monfet, J.P. [Canam Manac Group, Inc., Boucherville, Quebec (Canada)

1997-12-31

157

Global emissions of terpenoid VOCs from terrestrial vegetation in the last millennium  

PubMed Central

We investigated the millennial variability (1000 A.D.–2000 A.D.) of global biogenic volatile organic compound (BVOC) emissions by using two independent numerical models: The Model of Emissions of Gases and Aerosols from Nature (MEGAN), for isoprene, monoterpene, and sesquiterpene, and Lund-Potsdam-Jena-General Ecosystem Simulator (LPJ-GUESS), for isoprene and monoterpenes. We found the millennial trends of global isoprene emissions to be mostly affected by land cover and atmospheric carbon dioxide changes, whereas monoterpene and sesquiterpene emission trends were dominated by temperature change. Isoprene emissions declined substantially in regions with large and rapid land cover change. In addition, isoprene emission sensitivity to drought proved to have significant short-term global effects. By the end of the past millennium MEGAN isoprene emissions were 634 TgC yr?1 (13% and 19% less than during 1750–1850 and 1000–1200, respectively), and LPJ-GUESS emissions were 323 TgC yr?1(15% and 20% less than during 1750–1850 and 1000–1200, respectively). Monoterpene emissions were 89 TgC yr?1(10% and 6% higher than during 1750–1850 and 1000–1200, respectively) in MEGAN, and 24 TgC yr?1 (2% higher and 5% less than during 1750–1850 and 1000–1200, respectively) in LPJ-GUESS. MEGAN sesquiterpene emissions were 36 TgC yr?1(10% and 4% higher than during 1750–1850 and 1000–1200, respectively). Although both models capture similar emission trends, the magnitude of the emissions are different. This highlights the importance of building better constraints on VOC emissions from terrestrial vegetation. PMID:25866703

Acosta Navarro, J C; Smolander, S; Struthers, H; Zorita, E; Ekman, A M L; Kaplan, J O; Guenther, A; Arneth, A; Riipinen, I

2014-01-01

158

Global emissions of terpenoid VOCs from terrestrial vegetation in the last millennium  

NASA Astrophysics Data System (ADS)

We investigated the millennial variability (1000 A.D.-2000 A.D.) of global biogenic volatile organic compound (BVOC) emissions by using two independent numerical models: The Model of Emissions of Gases and Aerosols from Nature (MEGAN), for isoprene, monoterpene, and sesquiterpene, and Lund-Potsdam-Jena-General Ecosystem Simulator (LPJ-GUESS), for isoprene and monoterpenes. We found the millennial trends of global isoprene emissions to be mostly affected by land cover and atmospheric carbon dioxide changes, whereas monoterpene and sesquiterpene emission trends were dominated by temperature change. Isoprene emissions declined substantially in regions with large and rapid land cover change. In addition, isoprene emission sensitivity to drought proved to have significant short-term global effects. By the end of the past millennium MEGAN isoprene emissions were 634 TgC yr-1 (13% and 19% less than during 1750-1850 and 1000-1200, respectively), and LPJ-GUESS emissions were 323 TgC yr-1(15% and 20% less than during 1750-1850 and 1000-1200, respectively). Monoterpene emissions were 89 TgC yr-1(10% and 6% higher than during 1750-1850 and 1000-1200, respectively) in MEGAN, and 24 TgC yr-1 (2% higher and 5% less than during 1750-1850 and 1000-1200, respectively) in LPJ-GUESS. MEGAN sesquiterpene emissions were 36 TgC yr-1(10% and 4% higher than during 1750-1850 and 1000-1200, respectively). Although both models capture similar emission trends, the magnitude of the emissions are different. This highlights the importance of building better constraints on VOC emissions from terrestrial vegetation.

Acosta Navarro, J. C.; Smolander, S.; Struthers, H.; Zorita, E.; Ekman, A. M. L.; Kaplan, J. O.; Guenther, A.; Arneth, A.; Riipinen, I.

2014-06-01

159

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...

160

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...

161

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

162

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

163

Seasonal and species-specific response of VOC emissions by Mediterranean woody plant to elevated ozone concentrations  

NASA Astrophysics Data System (ADS)

Although certain factors controlling plant emission rates of volatile organic compounds (VOCs) are reasonably well understood, the influence of elevated ozone concentrations as abiotic stress is mostly unknown. Therefore, we studied the effects of ozone concentrations on seasonal biogenic volatile organic compound (BVOC) emissions by different Mediterranean plant species in open top chambers (OTC). Three ozone treatments were established: filtered air (F), non-filtered air (NF), and fumigated air (NF+) adding 40 nl l -1 of ozone over NF. We studied the response of VOC emission in saplings of four Mediterranean woody plant species and subspecies: Ceratonia siliqua L., Olea europaea L., Quercus ilex spp. ilex L., and Quercus ilex spp. rotundifolia L. as representative of natural Mediterranean vegetation. No visible symptoms were detected on the leaves. No significant effect was found on net photosynthetic rates or stomatal conductance except for an increase in net photosynthetic rates in Quercus ilex ilex in spring and summer and an overall slight increase in Quercus ilex rotundifolia. Emissions of the total VOCs from Ceratonia siliqua in summer, and from Olea europaea and Quercus ilex rotundifolia in spring increased in ozone fumigated OTC in comparison with F or NF OTC. Decreased emissions were found in Quercus ilex rotundifolia in summer. There were no significant differences between ozone fumigation treatments for the other plant species and seasons. When considering particular VOCs, the results were also variable among species and time of the year. While ?-pinene emissions decreased with ozone fumigation in Olea europaea, ?-pinene and limonene emissions increased in Quercus ilex ilex. The responses of these particular VOCs did not always match the responses of total VOCs. In spite of this strong variability, when considering overall annual data for all species and seasons, there were increased net photosynthetic rates (37%) and limonene (95%) and total VOC (45%) emission rates in ozone-fumigated plants, whereas stomatal conductance did not change. Since VOCs are precursors of ozone, the increase in BVOC emission as a consequence of elevated tropospheric ozone concentrations may lead to positive feedback mechanisms in ozone formation.

Llusià, J.; Peñuelas, J.; Gimeno, B. S.

164

On-line field measurements of VOC emissions from a spruce tree at SMEAR Estonia  

NASA Astrophysics Data System (ADS)

We have investigated VOC emissions from a Norway spruce tree (Picea abies) in a hemi-boreal mixed forest in September and October 2012, using Proton Transfer Reaction Mass Spectrometry and Gas Chromatography - Mass Spectrometry techniques, applied in a dynamic branch enclosure system that was automatically operated with an electrical compressor. Parallel to BVOC measurements a vast amount of atmospheric (CO2, CH4, H2O, CO, particles) and meteorological (temperature, relative humidity, photosynthetic active radiation, wind speed and direction, precipitation) parameters were measured in the ambient atmosphere and inside the cuvette enclosure (temperature, relative humidity, O3). Prior to the measuring period, an innovatory experimental setup was built at Järvselja forest station, in order to accomplish the detection of BVOC and minimize sampling losses. Therefore, a new inlet line, consisting of 19.4m of heated and isolated glass tube was constructed. The new inlet system applied, allowed the on-line detection and calculation of sesquiterpene (SQT) emission rates for the first time in a hemi-boreal forest site. It total, 12 atmospheric relevant BVOCs were continuously monitored for a three week period and the emission rates were derived. Along with diurnal profiles and continuous timeless, some interesting observations showed the possibility of ozone effect on SQT emissions, the possibility of radiation effect on MT emissions, the higher induced emissions due to mechanical stress and the possibility for a valid intercomparison between different spruce trees located in mountain Kleiner Feldberg (Germany) and in Järvseja forest station (Estonia).

Bourtsoukidis, Efstratios; Bonn, Boris; Noe, Steffen

2013-04-01

165

Trends in the emissions of Volatile Organic Compounds (VOCs) from light-duty gasoline vehicles tested on chassis dynamometers in Southern California  

NASA Astrophysics Data System (ADS)

We present fleet average VOC emission rate trends for the longest running in-use light-duty gasoline Vehicle Surveillance Program (VSP) in Southern California. Tailpipe emissions data from a limited number of vehicles tested as part of the VSP show that the 2003 fleet average emissions decreased by about 80% for most VOCs relative to the 1995 fleet. Vehicle evaporative emission rates decreased more than 90% for most compounds from the 1999 to the 2003 fleet. Tailpipe benzene-normalized emission rate ratios for most compounds were relatively stable. Evaporative emission rate ratios and weight percentages have changed significantly from the 1999 fleet to the 2003 fleet indicating a significant change in the evaporative emission species patterns. The tailpipe NMHC (Non-Methane HydroCarbon) emission reductions observed between the 1995 fleet and the 2003 fleet likely resulted from the retirement of non-catalyst vehicles in the fleets (49%) and the combined effect of the turn-over of catalyst-equipped vehicles and switch to Phase III gasoline (27%). Our results are consistent with those observed in the Swiss tunnel study. Benzene-normalized emission rate ratios for C2 compounds, aldehydes, and 1,3 butadiene are much higher in tailpipe exhaust than those in evaporative emissions. C4-C5 hydrocarbon ratios in evaporative emissions are much higher than those in exhaust. C8 aromatic compound ratios are comparable for tailpipe and evaporative emissions (hot-soak). Such ratio differences can be used to estimate the relative contributions of vehicle exhaust and evaporative emission to ambient VOCs. The contribution of emissions from malfunctioning vehicles to total fleet emissions increased from 16% to 32% for the 1995 fleet to the 2003 fleet even though the percentage of malfunctioning vehicles in the fleet decreased from 10% to 5%. Most malfunctioning vehicles are vehicles that are at least 10 years old and generally have higher acetylene emission rate ratios. The effective identification and control of these malfunctioning vehicles will become increasingly important for improving mobile source emission estimates as well as reducing future tailpipe emissions.

Pang, Yanbo; Fuentes, Mark; Rieger, Paul

2014-02-01

166

Effects of Environmental and Test Conditions on VOC Emissions from "Wet" Coating Materials  

E-print Network

material (wood stain). Simulation results indicate that air velocity and sample application time only concentration [mg m-3 ] Ca0 equilibrium vapor phase concentration for the wood stain [mg m-3 ] Cl initial VOC concentration in the wood stain [mg m-3 ] Cm VOC concentration in the material film [mg m-3 ] Cm, 0 initial VOC

Chen, Qingyan "Yan"

167

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

168

Specification of Biogenic VOC Emission Data in the Coupled System of Regional Climate and Atmospheric Chemistry/Aerosols Model  

NASA Astrophysics Data System (ADS)

Coupling of regional climate model RegCM (Pal et al., 2007) and atmospheric chemistry/aerosols model CAMx (Environ, 2006) is being developed at our department under the CECILIA project (EC 6th FP) with the aim to study climate forcing due to atmospheric chemistry/aerosols on regional scale. Regional climate model RegCM with the resolution of 10 km drives transport, chemistry and dry/wet deposition of the CAMx model being operated on the Central and Eastern European domain and consequently the radiative active agents from the CAMx model enter the radiative transfer schemes for the calculation of heating rate changes in the regional climate model. In order to increase the accuracy of land cover data in this model system, a new input dataset has been prepared and used for the calculation of emissions of volatile organic compounds (VOCs) from natural sources. This dataset is mainly based on the single tree species database from the european project of JRC in Ispra - Agriculture, Forestry, and Other Land Uses in Europe (AFOLU) which covers most of the model domain. For the locations where AFOLU data were not available, i.e. basically non-EU areas, the USGS Eurasia land cover database has been used. Both databases are available in 1 km resolution. Emission factors for new land cover categories were obtained either from the laboratory measurements or from the literature. The Guenther et al. (1995) model algorithm has been used for the calculation of biogenic VOC (BVOC) emission fluxes. Effects of new land cover and BVOC emission data on the CAMx model simulations of low level ozone in the year 2000 have been studied. Improvement of model results when compared with the measured data may be seen, especially in the simulation of extreme values such as ozone summer maxima. References: - ENVIRON Corp., 2006. CAMx User’s Guide, version 4.40 - Guenther A., Hewitt N., Erickson D., Fall R., Geron Ch., Graedel T., Harley P., Klinger L., Lerdau M., McKay W. A., Pierce T., Scholes B., Steinbrecher R., Tallamraju R., Taylor J., Zimmerman P., 1995. Global model of natural organic compound emissions. J. Geophys. Res. 100, 8873-8892. - Pal, J. S., Giorgi, F., Bi, X., Elguindi, N., Solomon, F., Gao, X., Rauscher, S. A., Francisco, R., Zakey, A., Winter, J., Ashfaq, M., Syed, F. S., Bell, J. L., Diffenbaugh, N. S., Karmacharya, J., Konare, A., Martinez, D., da Rocha, R. P., Sloan, L. C., and Steiner, A. L., 2007. Regional climate modeling for the developing world: The ICTP RegCM3 and RegCNET, B. Am. Meteor. Soc., 88, 1395-1409.

Zemankova, K.; Huszar, P.

2009-12-01

169

Characterization of VOCs Across Pennsylvania: Assessing Emissions from Rural, Forested, Agricultural and Natural Gas Drilling-Impacted Areas  

NASA Astrophysics Data System (ADS)

Volatile organic compounds (VOCs) of both biogenic and anthropogenic origin are important to troposphere chemistry, particularly the formation of photochemical smog and secondary organic aerosol. There is concern that increased natural gas exploration may lead to increased emissions of certain VOCs during well development and due to fugitive emissions from operational well sites and pipelines. For a six-day period in June 2012, a variety of VOCs were measured using canister sampling from a mobile measurement platform. Transects from southwestern to northeastern Pennsylvania were studied, with samples obtained in rural, forested, urban, farm-impacted and gas well-impacted sites. As expected, biogenic VOCs and isoprene oxidation products were enhanced in forested regions, while anthropogenic non-methane hydrocarbons were enhanced in urban areas. BTEX (benzene, toluene, ethylbenzene and xylenes) was enhanced in urban areas, but the concentrations of BTEX measured near developing and existing natural gas sites were similar to rural and forested sites. Halogenated hydrocarbons and Freon compounds were consistent at all site locations. We will discuss the specific concentrations and signatures of these compounds and assess the potential impact of agricultural activities and gas well development on the observed VOC concentrations and variability.

Grannas, A. M.; Fuentes, J. D.; Ramos-Garcés, F.; Wang, D. K.; Martins, D. K.

2012-12-01

170

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...

171

LOW-VOC COATINGS FOR AUTOMOBILE REFINISHING USING NOVEL POLYMER RESINS  

EPA Science Inventory

Coating operations release a significant portion of the non-mobile source, volatile organic compounds (VOCs) into the air. The U.S. EPA's Emissions Characterization and Prevention Branch has formulated novel low-VOC coatings for the automotive refinishing sector that reduce VOC l...

172

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

173

Light-Duty GDI Vehicle PM and VOC Speciated Emissions at Differing Ambient Temperatures with Ethanol Blend Gasoline  

EPA Science Inventory

With the rise in the use of ethanol-blend gasoline in the US and more manufacturers implementing gasoline direct injection (GDI) technologies, interest is increasing in how these fuel blends affect PM and VOC emissions in GDI technology vehicles. EPA conducted a study characteri...

174

EMISSIONS OF BIOGENIC OXIDANT AND PM PRECURSORS: VERY HIGH REACTIVITY VOCS AND SURFACE LAYER CHEMISTRY ABOVE FORESTS  

EPA Science Inventory

Biogenic emissions of volatile organic compounds (VOCs) -- chemicals emitted naturally by the green foliage of a forest, for example -- have been repeatedly shown to be important contributors to ozone pollution levels in many parts of the country. Recently, both the National Rese...

175

ESTIMATION OF THE RATE OF VOC EMISSIONS FROM SOLVENT-BASED INDOOR COATING MATERIALS BASED ON PRODUCT FORMULATION  

EPA Science Inventory

Two computational methods are proposed for estimation of the emission rate of volatile organic compounds (VOCs) from solvent-based indoor coating materials based on the knowledge of product formulation. The first method utilizes two previously developed mass transfer models with ...

176

Volatile Organic Compound (VOC) emissions from feedlot pen surface materials as affected by within pen location, moisture, and temperature  

Technology Transfer Automated Retrieval System (TEKTRAN)

A laboratory study was conducted to evaluate the effects of pen location, moisture, and temperature on emissions of volatile organic compounds (VOC) from surface materials obtained from feedlot pens where beef cattle were fed a diet containing 30% wet distillers grain plus solubles. Surface material...

177

Measurement and enhanced monitoring of BTEX and VOC emissions from glycol dehydrators  

SciTech Connect

The Clean Air Act Amendments of 1990 and activities by several states have resulted in increasing regulatory pressure on emissions of benzene, toluene, ethylbenzene, and xylenes (BTEX) and total volatile organic compounds (VOC) from glycol dehydration units. There are no standard sampling and analytical methods established by regulatory agencies for determining emissions from glycol dehydrators, and the methods initially used by the industry showed significant variability in results. To address this lack of methods, the Gas Research Institute (GRI) began an effort to develop measurement methods and emission estimation techniques for glycol dehydrators. Ten methods were evaluated based on the criteria of ease of use, cost, and precision and bias in a series of field experiments at ten sites. The results of the project showed that GRI-GLYCalc should be used to initially screen a large number of units and that atmospheric rich/lean glycol measurements should be made to refine these initial estimates. GRI has also initiated efforts to assist the industry in complying with enhanced monitoring requirements for glycol dehydrators. These enhanced monitoring protocols may be based on using condenser temperatures in conjunction with computer programs such as GRI-GLYCalc. Additional test data will be collected using the methods developed in the previous efforts to validate the computer program predictions for condenser control efficiencies.

Rueter, C.O.; Reif, D.L.; Menzies, W.R.; Evans, J.M.

1995-12-01

178

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...

179

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

EPA Science Inventory

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

180

Ozone trends across the United States over a period of decreasing NOx and VOC emissions.  

PubMed

In this work, we evaluate ambient ozone trends at urban, suburban, and rural monitoring sites across the United States over a period of decreasing NOx and VOC emissions (1998-2013). We find that decreasing ozone trends generally occur in the summer, in less urbanized areas, and at the upper end of the ozone distribution. Conversely, increasing ozone trends generally occur in the winter, in more urbanized areas, and at the lower end of the ozone distribution. The 95(th) percentile ozone concentrations decreased at urban, suburban, and rural monitors by 1-2 ppb/yr in the summer and 0.5-1 ppb/yr in the winter. In the summer, there are both increasing and decreasing trends in fifth percentile ozone concentrations of less than 0.5 ppb/yr at urban and suburban monitors, while fifth percentile ozone concentrations at rural monitors decreased by up to 1 ppb/yr. In the winter, fifth percentile ozone concentrations generally increased by 0.1-1 ppb/yr. These results demonstrate the large scale success of U.S. control strategies targeted at decreasing peak ozone concentrations. In addition, they indicate that as anthropogenic NOx emissions have decreased, the ozone distribution has been compressed, leading to less spatial and temporal variability. PMID:25517137

Simon, Heather; Reff, Adam; Wells, Benjamin; Xing, Jia; Frank, Neil

2015-01-01

181

ATLAS OF SOURCE EMISSION PARTICLES  

EPA Science Inventory

An atlas of various source emission particles characterized by electron optical techniques has been compiled for use by air pollution investigators. The particles studied were emitted by mobile, stationary, and natural sources. Sources included automobiles, manufacturing operatio...

182

DEVELOPMENT OF THE 1980 NAPAP (NATIONAL ACID PRECIPITATION ASSESSMENT PROGRAM) EMISSIONS INVENTORY: AREA SOURCES, PRODUCT D (VERSION 5.0)  

EPA Science Inventory

The 1980 NAPAP Emissions Inventory area source emissions data for the 48 contiguous United States are contained in the data file. Annual emissions of 11 pollutants (SO2, SO4, NOx, Pb, CO, HCl, HF, NH3, TSP, VOC, and total hydrocarbons) from 88 area source categories in 3,070 coun...

183

RESEARCH AREA -- MOBILE SOURCE OZONE PRECURSOR EMISSIONS CHARACTERIZATION AND MODELING (ATMOSPHERIC PROTECTION BRANCH - AIR POLLUTION PREVENTION AND CONTROL DIVISION, NRMRL)  

EPA Science Inventory

The objective of this program is to characterize mobile source emissions which are one of the largest sources of tropospheric ozone precursor emissions (CO, NOx, and volatile organic compounds (VOCs) in the U.S. Due to the dynamic operation of motor vehicles, emissions are highl...

184

Determination of a cost-effective air pollution control technology for the control of VOC and HAP emissions from a steroids processing plant  

SciTech Connect

A steroids processing plant located in northeastern Puerto Rico emits a combined average of 342 lb/hr of hazardous air pollutants (HAPs) and volatile organic compounds (VOCs) from various process operations. The approach that this facility used to implement maximum achievable control technology (MACT) may assist others who must contend with MACT for pharmaceutical or related manufacturing facilities. Federal air regulations define MACT standards for stationary sources emitting any of 189 HAPs. The MACT standards detailed in the NESHAPs are characterized by industry and type of emission control system or technology. It is anticipated that the standard will require HAP reductions of approximately 95%. The steroid plant`s emissions include the following pollutant loadings: VOC/HAP Emission Rate (lb/hr): Methanol 92.0; Acetone 35.0; Methylene chloride 126.0; Chloroform 25.0; Ethyl acetate 56.0; Tetrahydrofuran 5.00; and 1,4-Dioxane 3.00. The facility`s existing carbon adsorption control system was nearing the end of its useful life, and the operators sought to install an air pollution control system capable of meeting MACT requirements for the pharmaceutical industry. Several stand-alone and hybrid control technologies were considered for replacement of the carbon adsorption system at the facility. This paper examines the following technologies: carbon adsorption, membrane separation, thermal oxidation, membrane separation-carbon adsorption, and condensation-carbon adsorption. Each control technology is described; the advantages and disadvantages of utilizing each technology for the steroid processing plant are examined; and capital and operating costs associated with the implementation of each technology are presented. The rationale for the technology ultimately chosen to control VOC and HAP emissions is presented.

Hamel, T.M. [O`Brien and Gere Engineers, Inc., Syracuse, NY (United States)

1997-12-31

185

Efficient control of odors and VOC emissions via activated carbon technology.  

PubMed

This research study was undertaken to enhance the efficiency and economy of carbon scrubbers in controlling odors and volatile organic compounds (VOCs) at the wastewater collection and treatment facilities of the Bureau of Sanitation, City of Los Angeles. The butane activity and hydrogen sulfide breakthrough capacity of activated carbon were assessed. Air streams were measured for odorous gases and VOCs and removal efficiency (RE) determined. Carbon towers showed average to excellent removal of odorous compounds, VOCs, and siloxanes; whereas, wet scrubbers demonstrated good removal of odorous compounds but low to negative removal of VOCs. It was observed that the relative humidity and empty bed contact time are one of the most important operating parameters of carbon towers impacting the pollutant RE. Regular monitoring of activated carbon and VOCs has resulted in useful information on carbon change-out frequency, packing recommendations, and means to improve performance of carbon towers. PMID:25112027

Mohamed, Farhana; Kim, James; Huang, Ruey; Nu, Huong Ton; Lorenzo, Vlad

2014-07-01

186

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

187

Legal requirements for proving the fugitive VOCs emissions defense to an alleged PSD permit violation: Developing admissible evidence and expert testimony on not reasonably pass through and industry practice  

SciTech Connect

Except in specified circumstances, fugitive emissions of VOCs are not considered in determining whether a facility is a major source subject to the PSD permitting program. Violations of the permitting program may result in substantial fines and thus emitters charged with violating PSD permit requirements have a strong incentive to challenge the identification of their sites as major sources. Such a challenge will be greatly bolstered by identifying at least some of the emissions upon which the designation is based as fugitive. Developing persuasive, admissible evidence is necessary to prove the unreasonableness of collecting those emissions.

Oppenfeld, R.R. von; Hiser, E.L.; Evans, D.M. [Kane Jorden von Oppenfeld Bischoff & Biskind P.L.C., Phoenix, AZ (United States)

1997-12-31

188

VOC Control: Current practices and future trends  

SciTech Connect

One of the most formidable challenges posed by the Clean Air Act Amendments of 1990 (CAAA) is the search for efficient and economical control strategies for volatile organic compounds (VOCs). VOCs are precursors to ground-level ozone, a major component in the formation of smog. Under the CAAA, thousands of currently unregulated sources will be required to reduce or eliminate VOC emissions. In addition, sources that are currently regulated may seek to evaluate alternative VOC control strategies to meet stricter regulatory requirements such as the maximum achievable control technology (MACT) requirements in Title III of the CAAA. Because of the increasing attention being given to VOC control, the American Institute of Chemical Engineers' (AIChE) Center for Waste Reduction Technologies (CWRT) initiated a study of VOC control technologies and regulatory initiatives. A key objective of the project was to identify and describe existing VOC control technologies and air regulations, as well as emerging technologies and forthcoming regulations. That work is the basis for this article.

Moretti, E.C.; Mukhopadhyay, N. (Baker Environment, Inc., Coraopolis, PA (United States))

1993-07-01

189

METHANE EMISSIONS FROM INDUSTRIAL SOURCES  

EPA Science Inventory

The chapter identifies and describes major industrial sources of methane (CH4) emissions. or each source type examined, it identifies CH4 release points and discusses in detail the factors affecting emissions. t also summarizes and discusses available global and country-specific ...

190

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

191

DEVELOPMENT OF THE 1980 NAPAP (NATIONAL ACID PRECIPITATION ASSESSMENT PROGRAM) EMISSIONS INVENTORY: POINT SOURCES, PRODUCT B (VERSION 5.0)  

EPA Science Inventory

The 1980 NAPAP Emissions Inventory point source emissions data for the 48 contiguous United States are contained in the data file. Annual emissions of 11 pollutants (SO2, SO4, NOx, Pb, CO, HC1, HF, NH3, TSP, VOC, and total hydrocarbons) from 13,769 plants encompassing 34,483 emis...

192

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...

193

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...

194

Review of unsaturated-zone transport and attenuation of volatile organic compound (VOC) plumes leached from shallow source zones.  

PubMed

Reliable prediction of the unsaturated zone transport and attenuation of dissolved-phase VOC (volatile organic compound) plumes leached from shallow source zones is a complex, multi-process, environmental problem. It is an important problem as sources, which include solid-waste landfills, aqueous-phase liquid discharge lagoons and NAPL releases partially penetrating the unsaturated zone, may persist for decades. Natural attenuation processes operating in the unsaturated zone that, uniquely for VOCs includes volatilisation, may, however, serve to protect underlying groundwater and potentially reduce the need for expensive remedial actions. Review of the literature indicates that only a few studies have focused upon the overall leached VOC source and plume scenario as a whole. These are mostly modelling studies that often involve high strength, non-aqueous phase liquid (NAPL) sources for which density-induced and diffusive vapour transport is significant. Occasional dissolved-phase aromatic hydrocarbon controlled infiltration field studies also exist. Despite this lack of focus on the overall problem, a wide range of process-based unsaturated zone - VOC research has been conducted that may be collated to build good conceptual model understanding of the scenario, particularly for the much studied aromatic hydrocarbons and chlorinated aliphatic hydrocarbons (CAHs). In general, the former group is likely to be attenuated in the unsaturated zone due to their ready aerobic biodegradation, albeit with rate variability across the literature, whereas the fate of the latter is far less likely to be dominated by a single mechanism and dependent upon the relative importance of the various attenuation processes within individual site - VOC scenarios. Analytical and numerical modelling tools permit effective process representation of the whole scenario, albeit with potential for inclusion of additional processes - e.g., multi-mechanistic sorption phase partitioning, and provide good opportunity for further sensitivity analysis and development to practitioner use. There remains a significant need to obtain intermediate laboratory-scale and particularly field-scale (actual site and controlled release) datasets that address the scenario as a whole and permit validation of the available models. Integrated assessment of the range of simultaneous processes that combine to influence leached plume generation, transport and attenuation in the unsaturated zone is required. Component process research needs are required across the problem scenario and include: the simultaneous volatilisation and dissolution of source zones; development of appropriate field-scale dispersion estimates for the unsaturated zone; assessment of transient VOC exchanges between aqueous, vapour and sorbed phases and their influence upon plume attenuation; development of improved field methods to recognise and quantify biodegradation of CAHs; establishment of the influence of co-contaminants; and, finally, translation of research findings into more robust practitioner practice. PMID:21316792

Rivett, Michael O; Wealthall, Gary P; Dearden, Rachel A; McAlary, Todd A

2011-04-25

195

Review of unsaturated-zone transport and attenuation of volatile organic compound (VOC) plumes leached from shallow source zones  

NASA Astrophysics Data System (ADS)

Reliable prediction of the unsaturated zone transport and attenuation of dissolved-phase VOC (volatile organic compound) plumes leached from shallow source zones is a complex, multi-process, environmental problem. It is an important problem as sources, which include solid-waste landfills, aqueous-phase liquid discharge lagoons and NAPL releases partially penetrating the unsaturated zone, may persist for decades. Natural attenuation processes operating in the unsaturated zone that, uniquely for VOCs includes volatilisation, may, however, serve to protect underlying groundwater and potentially reduce the need for expensive remedial actions. Review of the literature indicates that only a few studies have focused upon the overall leached VOC source and plume scenario as a whole. These are mostly modelling studies that often involve high strength, non-aqueous phase liquid (NAPL) sources for which density-induced and diffusive vapour transport is significant. Occasional dissolved-phase aromatic hydrocarbon controlled infiltration field studies also exist. Despite this lack of focus on the overall problem, a wide range of process-based unsaturated zone — VOC research has been conducted that may be collated to build good conceptual model understanding of the scenario, particularly for the much studied aromatic hydrocarbons and chlorinated aliphatic hydrocarbons (CAHs). In general, the former group is likely to be attenuated in the unsaturated zone due to their ready aerobic biodegradation, albeit with rate variability across the literature, whereas the fate of the latter is far less likely to be dominated by a single mechanism and dependent upon the relative importance of the various attenuation processes within individual site — VOC scenarios. Analytical and numerical modelling tools permit effective process representation of the whole scenario, albeit with potential for inclusion of additional processes — e.g., multi-mechanistic sorption phase partitioning, and provide good opportunity for further sensitivity analysis and development to practitioner use. There remains a significant need to obtain intermediate laboratory-scale and particularly field-scale (actual site and controlled release) datasets that address the scenario as a whole and permit validation of the available models. Integrated assessment of the range of simultaneous processes that combine to influence leached plume generation, transport and attenuation in the unsaturated zone is required. Component process research needs are required across the problem scenario and include: the simultaneous volatilisation and dissolution of source zones; development of appropriate field-scale dispersion estimates for the unsaturated zone; assessment of transient VOC exchanges between aqueous, vapour and sorbed phases and their influence upon plume attenuation; development of improved field methods to recognise and quantify biodegradation of CAHs; establishment of the influence of co-contaminants; and, finally, translation of research findings into more robust practitioner practice.

Rivett, Michael O.; Wealthall, Gary P.; Dearden, Rachel A.; McAlary, Todd A.

2011-04-01

196

Biological anoxic treatment of O?-free VOC emissions from the petrochemical industry: a proof of concept study.  

PubMed

An innovative biofiltration technology based on anoxic biodegradation was proposed in this work for the treatment of inert VOC-laden emissions from the petrochemical industry. Anoxic biofiltration does not require conventional O2 supply to mineralize VOCs, which increases process safety and allows for the reuse of the residual gas for inertization purposes in plant. The potential of this technology was evaluated in a biotrickling filter using toluene as a model VOC at loads of 3, 5, 12 and 34 g m(-3)h(-1) (corresponding to empty bed residence times of 16, 8, 4 and 1.3 min) with a maximum elimination capacity of ?3 g m(-3)h(-1). However, significant differences in the nature and number of metabolites accumulated at each toluene load tested were observed, o- and p-cresol being detected only at 34 g m(-3)h(-1), while benzyl alcohol, benzaldehyde and phenol were detected at lower loads. A complete toluene removal was maintained after increasing the inlet toluene concentration from 0.5 to 1 g m(-3) (which entailed a loading rate increase from 3 to 6 g m(-3)h(-1)), indicating that the system was limited by mass transfer rather than by biological activity. A high bacterial diversity was observed, the predominant phyla being Actinobacteria and Proteobacteria. PMID:23811365

Muñoz, Raúl; Souza, Theo S O; Glittmann, Lina; Pérez, Rebeca; Quijano, Guillermo

2013-09-15

197

Volatile organic compound emissions from unconventional natural gas production: Source signatures and air quality impacts  

NASA Astrophysics Data System (ADS)

Advances in horizontal drilling and hydraulic fracturing over the past two decades have allowed access to previously unrecoverable reservoirs of natural gas and led to an increase in natural gas production. Intensive unconventional natural gas extraction has led to concerns about impacts on air quality. Unconventional natural gas production has the potential to emit vast quantities of volatile organic compounds (VOCs) into the atmosphere. Many VOCs can be toxic, can produce ground-level ozone or secondary organic aerosols, and can impact climate. This dissertation presents the results of experiments designed to validate VOC measurement techniques, to quantify VOC emission rates from natural gas sources, to identify source signatures specific to natural gas emissions, and to quantify the impacts of these emissions on potential ozone formation and human health. Measurement campaigns were conducted in two natural gas production regions: the Denver-Julesburg Basin in northeast Colorado and the Marcellus Shale region surrounding Pittsburgh, Pennsylvania. An informal measurement intercomparison validated the canister sampling methodology used throughout this dissertation for the measurement of oxygenated VOCs. Mixing ratios of many VOCs measured during both campaigns were similar to or higher than those observed in polluted cities. Fluxes of natural gas-associated VOCs in Colorado ranged from 1.5-3 times industry estimates. Similar emission ratios relative to propane were observed for C2-C6 alkanes in both regions, and an isopentane:n-pentane ratio ?1 was identified as a unique tracer for natural gas emissions. Source apportionment estimates indicated that natural gas emissions were responsible for the majority of C2-C8 alkanes observed in each region, but accounted for a small proportion of alkenes and aromatic compounds. Natural gas emissions in both regions accounted for approximately 20% of hydroxyl radical reactivity, which could hinder federal ozone standard compliance in downwind cities. A health risk assessment showed no increase in cancer or chronic non-cancer risk at locations near natural gas wells in Pennsylvania, but the contribution of natural gas emissions to total risk was 3-6 times higher near wells. These results will assist policy makers, natural gas producers, and citizen stakeholders in crafting effective policies to control VOC emissions from natural gas production activities.

Swarthout, Robert F.

198

Emissions of liquefied petroleum gas (LPG) from motor vehicles  

Microsoft Academic Search

Continuous on-site measurements of 50 speciated volatile organic compounds (VOCs) were conducted in downtown Guangzhou to characterize the sources and concentration profiles of ambient VOCs. The synchronicity in diurnal variation between the VOCs and NO suggests that traffic emissions were responsible for the observed VOCs in downtown Guangzhou.It was found that the three major constituent species of liquefied petroleum gas

Cheng-Hsun Lai; Chih-Chung Chang; Chieh-Heng Wang; Min Shao; Yuanhang Zhang; Jia-Lin Wang

2009-01-01

199

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

200

Comparison of the substrate effect on voc emissions from water based varnish and latex paint  

Microsoft Academic Search

Background, Aims and Scope  The building materials are recognised to be major contributors to indoor air contamination by volatile organic compounds (VOCs).\\u000a The improvement of the quality of the environment within buildings is a topic of increasing research and public interest.\\u000a Legislation in preparation by the European Commission may induce, in the near future, European Union Member States to solicit\\u000a the

Gabriela V. Silva; M. Teresa; S. D. Vasconcelos; Armando M. Santos; Eduardo O. Fernandes

2003-01-01

201

Which emission sources are responsible for the volatile organic compounds in the atmosphere of Pearl River Delta?  

PubMed

A field measurement study of volatile organic compounds (VOCs) was simultaneously carried out in October-December 2007 at an inland Pearl River Delta (PRD) site and a Hong Kong urban site. A receptor model i.e. positive matrix factorization (PMF) was applied to the data for the apportionment of pollution sources in the region. Five and six sources were identified in Hong Kong and the inland PRD region, respectively. The major sources identified in the region were vehicular emissions, solvent use and biomass burning, whereas extra sources found in inland PRD included liquefied petroleum gas and gasoline evaporation. In Hong Kong, the vehicular emissions made the most significant contribution to ambient VOCs (48 ± 4%), followed by solvent use (43 ± 2%) and biomass burning (9 ± 2%). In inland PRD, the largest contributor to ambient VOCs was solvent use (46 ± 1%), and vehicular emissions contributed 26 ± 1% to ambient VOCs. The percentage contribution of vehicular emission in Hong Kong in 2007 is close to that obtained in 2001-2003, whereas in inland PRD the contribution of solvent use to ambient VOCs in 2007 was at the upper range of the results obtained in previous studies and twice the 2006 PRD emission inventory. The findings advance our knowledge of ozone precursors in the PRD region. PMID:21316844

Guo, H; Cheng, H R; Ling, Z H; Louie, P K K; Ayoko, G A

2011-04-15

202

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

NASA Astrophysics Data System (ADS)

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

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

2011-03-01

203

Global data set of biogenic VOC emissions calculated by the MEGAN model over the last 30 years  

SciTech Connect

The Model of Emissions of Gases and Aerosols from Nature (MEGANv2.1) together with the Modern-Era Retrospective Analysis for Research and Applications (MERRA) meteorological fields were used to create a global emission dataset of biogenic VOCs available on a monthly basis for the time period of 1980 - 2010. This dataset is called MEGAN-MACC. The model estimated mean annual total BVOC emission of 760 Tg(C) yr1 consisting of isoprene (70%), monoterpenes (11%), methanol (6%), acetone (3%), sesquiterpenes (2.5%) and other BVOC species each contributing less than 2 %. Several sensitivity model runs were performed to study the impact of different model input and model settings on isoprene estimates and resulted in differences of * 17% of the reference isoprene total. A greater impact was observed for sensitivity run applying parameterization of soil moisture deficit that led to a 50% reduction of isoprene emissions on a global scale, most significantly in specific regions of Africa, South America and Australia. MEGAN-MACC estimates are comparable to results of previous studies. More detailed comparison with other isoprene in ventories indicated significant spatial and temporal differences between the datasets especially for Australia, Southeast Asia and South America. MEGAN-MACC estimates of isoprene and*-pinene showed a reasonable agreement with surface flux measurements in the Amazon andthe model was able to capture the seasonal variation of emissions in this region.

Sindelarova, K.; Granier, Claire; Bouarar, I.; Guenther, Alex B.; Tilmes, S.; Stavrakou, T.; Muller, J. F.; Kuhn, U.; Stefani, P.; Knorr, W.

2014-09-09

204

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

205

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

206

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....

207

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....

208

NOVEL CERAMIC-ORGANIC VAPOR PERMEATION MEMBRANES FOR VOC REMOVAL - PHASE II  

EPA Science Inventory

Vapor permeation with highly permeable and organic-selective membranes is becoming an increasingly popular technique for preventing VOC emissions that are generated by a variety of stationary sources, including solvent and surface coating operations, gasoline storage operat...

209

The Chicago VOC trading system : the consequences of market design for performance  

E-print Network

The Chicago cap-and-trade approach to regulating stationary source VOC emissions in the Chicago ozone non-attainment area is a pioneering program that could set a precedent for other urban areas troubled by high ozone ...

Kosobud, Richard F.

2004-01-01

210

Factors controlling natural VOC emissions in a southeastern US pine forest  

NASA Astrophysics Data System (ADS)

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 loblolly pine saplings. Terpene emission rates in spring were the highest and most volatile for slash pine trees, possibly due to the influences of bud formation and elongation. Loblolly pine emissions, under a similar environmental temperature range, revealed different seasonal patterns of emissions when compared to those for slash pines. Emission rates of monoterpenes from slash and loblolly pine trees were found to depend on temperature, season's change (e.g., bud emissions), tree age, needle surface wetness, and rough handling. It is suggested that the emission control factors besides the environmental temperature should also be taken into account in assessing regional biogenic emissions for compling a worldwide hydrocarbon emission inventory. It is also found that monoterpene emission rates could easily change over a long period of time (e.g., years), and so it is desirable to analyze the emission data based on the short term (e.g., season, month) for reasonable temperature-emission algorithm.

Kim, Jo-Chun

211

Glycol dehydrator BTEX and VOC emissions testing results at two units in Texas and Louisiana. Volume 2. Appendices A-E. Final report, February-October 1994  

SciTech Connect

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. Site 1 test results yielded BTEX emission estimates that agreed reasonably well. Site 2 atmospheric rich/lean glycol and pressurized glycol emission results agreed closely with the total capture results for both BTEX and total VOCs. GRI-GLYCalc predictions using natural gas samples taken before the glycol absorber agreed well with the total capture results for total BTEX emissions.

Rueter, C.O.; Reif, D.L.; Myers, D.B.

1995-03-01

212

Glycol dehydrator BTEX and VOC emissions testing results at two units in Texas and Louisiana. Volume 1. Technical report. Final report, February-October 1994  

SciTech Connect

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. Site 1 test results yielded BTEX emission estimates that agreed reasonably well. Site 2 atmospheric rich/lean glycol and pressurized glycol emission results agreed closely with the total capture results for both BTEX and total VOCs. GRI-GLYCalc predictions using natural gas samples taken before the glycol absorber agreed well with the total capture results for total BTEX emissions.

Rueter, C.O.; Reif, D.L.; Myers, D.B.

1995-03-01

213

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

2013-10-01

214

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

215

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

216

Study of the VOC emissions from a municipal solid waste storage pilot-scale cell: Comparison with biogases from municipal waste landfill site  

SciTech Connect

Highlights: > Follow-up of the emission of VOCs in a municipal waste pilot-scale cell during the acidogenesis and acetogenesis phases. > Study from the very start of waste storage leading to a better understanding of the decomposition/degradation of waste. > Comparison of the results obtained on the pilot-scale cell with those from 3 biogases coming from the same landfill site. > A methodology of characterization for the progression of the stabilization/maturation of waste is finally proposed. - Abstract: The emission of volatile organic compounds (VOCs) from municipal solid waste stored in a pilot-scale cell containing 6.4 tonnes of waste (storage facility which is left open during the first period (40 days) and then closed with recirculation of leachates during a second period (100 days)) was followed by dynamic sampling on activated carbon and analysed by GC-MS after solvent extraction. This was done in order to know the VOC emissions before the installation of a methanogenesis process for the entire waste mass. The results, expressed in reference to toluene, were exploited during the whole study on all the analyzable VOCs: alcohols, ketones and esters, alkanes, benzenic and cyclic compounds, chlorinated compounds, terpene, and organic sulphides. The results of this study on the pilot-scale cell are then compared with those concerning three biogases from a municipal waste landfill: biogas (1) coming from waste cells being filled or recently closed, biogas (2) from all the waste storage cells on site, and biogas (3) which is a residual gas from old storage cells without aspiration of the gas. The analysis of the results obtained revealed: (i) a high emission of VOCs, principally alcohols, ketones and esters during the acidogenesis; (ii) a decrease in the alkane content and an increase in the terpene content were observed in the VOCs emitted during the production of methane; (iii) the production of heavier alkanes and an increase in the average number of carbon atoms per molecule of alkane with the progression of the stabilisation/maturation process were also observed. Previous studies have concentrated almost on the analysis of biogases from landfills. Our research aimed at gaining a more complete understanding of the decomposition/degradation of municipal solid waste by measuring the VOCs emitted from the very start of the landfill process i.e. during the acidogenesis and acetogenesis phases.

Chiriac, R., E-mail: rodica.chiriac@univ-lyon1.fr [Universite de Lyon, Universite Lyon 1, CNRS, UMR 5615, Laboratoire des Multimateriaux et Interfaces, 43 boulevard du 11 Novembre 1918, F-69622 Villeurbanne (France); De Araujos Morais, J. [Universite Federal de Paraiba, Campus I Departamento de Engenharia Civil e Ambiental, Joao Pessoa, Paraiba (Brazil); Carre, J. [Universite de Lyon, Universite Lyon 1, CNRS, UMR 5256, Institut de Recherche sur la Catalyse et l'Environnement, 43 boulevard du 11 Novembre 1918, F-69622 Villeurbanne (France); Bayard, R. [Universite de Lyon, INSA de Lyon, Laboratoire de Genie Civil et d'Ingenierie environnementale (LGCIE), F-69622 Villeurbanne (France); Chovelon, J.M. [Universite de Lyon, Universite Lyon 1, CNRS, UMR 5256, Institut de Recherche sur la Catalyse et l'Environnement, 43 boulevard du 11 Novembre 1918, F-69622 Villeurbanne (France); Gourdon, R. [Universite de Lyon, INSA de Lyon, Laboratoire de Genie Civil et d'Ingenierie environnementale (LGCIE), F-69622 Villeurbanne (France)

2011-11-15

217

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

EPA Science Inventory

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

218

[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

219

Global dataset of biogenic VOC emissions calculated by the MEGAN model over the last 30 years  

NASA Astrophysics Data System (ADS)

The Model of Emissions of Gases and Aerosols from Nature (MEGANv2.1) together with the Modern-Era Retrospective Analysis for Research and Applications (MERRA) meteorological fields were used to create a global emission dataset of biogenic volatile organic compounds (BVOC) available on a monthly basis for the time period of 1980-2010. This dataset is called MEGAN-MACC. The model estimated mean annual total BVOC emission of 760 Tg (C) yr-1 consisting of isoprene (70%), monoterpenes (11%), methanol (6%), acetone (3%), sesquiterpenes (2.5%) and other BVOC species each contributing less than 2%. Several sensitivity model runs were performed to study the impact of different model input and model settings on isoprene estimates and resulted in differences of up to ±17% of the reference isoprene total. A greater impact was observed for a sensitivity run applying parameterization of soil moisture deficit that led to a 50% reduction of isoprene emissions on a global scale, most significantly in specific regions of Africa, South America and Australia. MEGAN-MACC estimates are comparable to results of previous studies. More detailed comparison with other isoprene inventories indicated significant spatial and temporal differences between the datasets especially for Australia, Southeast Asia and South America. MEGAN-MACC estimates of isoprene, ?-pinene and group of monoterpenes showed a reasonable agreement with surface flux measurements at sites located in tropical forests in the Amazon and Malaysia. The model was able to capture the seasonal variation of isoprene emissions in the Amazon forest.

Sindelarova, K.; Granier, C.; Bouarar, I.; Guenther, A.; Tilmes, S.; Stavrakou, T.; Müller, J.-F.; Kuhn, U.; Stefani, P.; Knorr, W.

2014-04-01

220

Effects of climate change on volatile organic compound emissions from soil and litter  

NASA Astrophysics Data System (ADS)

Our knowledge of the variability and magnitude of volatile organic compound (VOC) emissions from soil and litter is relatively limited compared to what we know about VOC emissions from terrestrial plants. With climate change expecting to alter plant community composition, nitrogen (N) deposition rates, mean annual temperatures, and precipitation patterns, it is unknown how production and consumption of VOCs from litter and soil will respond. We spent the last four years quantifying VOC emissions from soil and litter, comparing VOC emissions to CO2 emissions, and identifying the biotic and abiotic controls on emission rates with both lab and field experiments using a proton transfer reaction mass spectrometer (PTR-MS). In all studies, methanol was the dominant VOC flux. VOC emissions were not driven by abiotic processes, as microbial sources accounted for 78% to 99% of the total VOC emissions from decomposing litter. Litter chemistry was correlated with the types of VOCs emitted and the net emissions of carbon as VOCs was found to be up to 88% of that emitted as CO2 suggesting that VOCs likely represent an important component of the carbon cycle in many terrestrial systems. Nitrogen additions drastically reduced VOC emissions from litter to near zero, though it is still not understood whether this was due to an increase in consumption or a decrease in production. Finally, field and lab experiments show that temperature and moisture are both important controls of certain VOC emissions from soils, but that the effects of these factors on VOC emissions are not necessarily equivalent to their effects on CO2 emissions. Together, these series of studies are moving us toward a predictive understanding of VOC emissions from soil and litter with the ultimate goal of incorporating these VOC emissions into global models of terrestrial VOC dynamics.

Gray, C. M.; Fierer, N.

2012-12-01

221

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

Technology Transfer Automated Retrieval System (TEKTRAN)

Air emissions from swine production facilities can cause odor nuisance issues. Peroxidase enzymes have been used to treat phenolic compounds in industrial wastewaters, but little is known about their efficacy for treating swine manure. The objective of the research was to determine the optimum app...

222

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

223

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...

224

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 ...

225

Monoterpene emissions from a Pacific Northwest Old-Growth Forest and impact on regionalbiogenic VOC emission estimates  

Microsoft Academic Search

Measurements of naturalhydrocarbon emission rates are reported for an ol d-growth Pacific Northwest coniferous forest. The emission data were collected for the two dominant species Douglas-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla) during the growing season in 1997 and 1998 using branch enclosure techniques. Samples were collected at different heights from 13 to 51 m within the canopy using

Shelley Pressley; Brian Lamb; Alex Guenther; Jack Chen; Eugene Allwine

226

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

227

VOCs and OVOCs distribution and control policy implications in Pearl River Delta region, China  

NASA Astrophysics Data System (ADS)

Ambient air measurements of volatile organic compounds (VOCs) and oxygenated volatile organic compounds (OVOCs) were conducted and characterised during a two-year grid study in the Pearl River Delta (PRD) region of southern China. The present grid study pioneered the systematic investigation of the nature and characteristics of complex VOC and OVOC sources at a regional scale. The largest contributing VOCs, accounting over 80% of the total VOCs mixing ratio, were toluene, ethane, ethyne, propane, ethene, butane, benzene, pentane, ethylbenzene, and xylenes. Sub-regional VOC spatial characteristics were identified, namely: i) relatively fresh pollutants, consistent with elevated vehicular and industrial activities, around the PRD estuary; and ii) a concentration gradient with higher mixing ratios of VOCs in the west as compared with the eastern part of PRD. Based on alkyl nitrate aging determination, a high hydroxyl radical (OH) concentration favoured fast hydrocarbon reactions and formation of locally produced ozone. The photochemical reactivity analysis showed aromatic hydrocarbons and alkenes together consisted of around 80% of the ozone formation potential (OFP) among the key VOCs. We also found that the OFP from OVOCs should not be neglected since their OFP contribution was more than one-third of that from VOCs alone. These findings support the choice of current air pollution control policy which focuses on vehicular sources but warrants further controls. Industrial emissions and VOCs emitted by solvents should be the next targets for ground-level ozone abatement.

Louie, Peter K. K.; Ho, Josephine W. K.; Tsang, Roy C. W.; Blake, Donald R.; Lau, Alexis K. H.; Yu, Jian Zhen; Yuan, Zibing; Wang, Xinming; Shao, Min; Zhong, Liuju

2013-09-01

228

Plant leaves as indoor air passive samplers for volatile organic compounds (VOCs).  

PubMed

Volatile organic compounds (VOCs) enter indoor environments through internal and external sources. Indoor air concentrations of VOCs vary greatly but are generally higher than outdoors. Plants have been promoted as indoor air purifiers for decades, but reports of their effectiveness differ. However, while air-purifying applications may be questionable, the waxy cuticle coating on leaves may provide a simple, cost-effective approach to sampling indoor air for VOCs. To investigate the potential use of plants as indoor air VOC samplers, a static headspace approach was used to examine the relationship between leaf and air concentrations, leaf lipid contents and octanol-air partition coefficients (Koa) for six VOCs and four plant species. The relationship between leaf and air concentrations was further examined in an actual residence after the introduction of several chlorinated VOC emission sources. Leaf-air concentration factors (LACFs), calculated from linear regressions of the laboratory headspace data, were found to increase as the solvent extractable leaf lipid content and Koa value of the VOC increased. In the studies conducted in the residence, leaf concentrations paralleled the changing air concentrations, indicating a relatively rapid air to leaf VOC exchange. Overall, the data from the laboratory and residential studies illustrate the potential for plant leaves to be used as cost effective, real-time indoor air VOC samplers. PMID:25434272

Wetzel, Todd A; Doucette, William J

2015-03-01

229

Monoterpene emissions from a Pacific Northwest Old-Growth Forest and impact on regional biogenic VOC emission estimates  

Microsoft Academic Search

Measurements of natural hydrocarbon emission rates are reported for an old-growth Pacific Northwest coniferous forest. The emission data were collected for the two dominant species Douglas-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla) during the growing season in 1997 and 1998 using branch enclosure techniques. Samples were collected at different heights from 13 to 51m within the canopy using the

Shelley Pressley; Brian Lamb; Hal Westberg; Alex Guenther; Jack Chen; Eugene Allwine

2004-01-01

230

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

Microsoft Academic Search

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

Yeh-Chung Chien

2007-01-01

231

Characterization of odorous charge and photochemical reactivity of VOC emissions from a full-scale food waste treatment plant in China.  

PubMed

Food waste treatment plants (FWTPs) are usually associated with odorous nuisance and health risks, which are partially caused by volatile organic compound (VOC) emissions. This study investigated the VOC emissions from a selected full-scale FWTP in China. The feedstock used in this plant was mainly collected from local restaurants. For a year, the FWTP was closely monitored on specific days in each season. Four major indoor treatment units of the plant, including the storage room, sorting/crushing room, hydrothermal hydrolysis unit, and aerobic fermentation unit, were chosen as the monitoring locations. The highest mean concentration of total VOC emissions was observed in the aerobic fermentation unit at 21,748.2-31,283.3?g/m(3), followed by the hydrothermal hydrolysis unit at 10,798.1-23,144.4?g/m(3). The detected VOC families included biogenic compounds (oxygenated compounds, hydrocarbons, terpenes, and organosulfur compounds) and abiogenic compounds (aromatic hydrocarbons and halocarbons). Oxygenated compounds, particularly alcohols, were the most abundant compounds in all samples. With the use of odor index analysis and principal components analysis, the hydrothermal hydrolysis and aerobic fermentation units were clearly distinguished from the pre-treatment units, as characterized by their higher contributions to odorous nuisance. Methanthiol was the dominant odorant in the hydrothermal hydrolysis unit, whereas aldehyde was the dominant odorant in the aerobic fermentation unit. Terpenes, specifically limonene, had the highest level of propylene equivalent concentration during the monitoring periods. This concentration can contribute to the increase in the atmospheric reactivity and ozone formation potential in the surrounding air. PMID:25766011

Ni, Zhe; Liu, Jianguo; Song, Mingying; Wang, Xiaowei; Ren, Lianhai; Kong, Xin

2015-03-01

232

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Performance Standards and National Emission Standards for Hazardous Air...Standards (NSPS) and National Emission Standards for Hazardous Air...Bulk Gasoline Terminals...Organic Compound (VOC) Yes. Emissions from the Polymer...

2010-04-14

233

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. PMID:22163629

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

2010-01-01

234

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

235

40 CFR 51.322 - Sources subject to emissions reporting.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Sources subject to emissions reporting...IMPLEMENTATION PLANS Reports Source Emissions and State Action Reporting § 51.322 Sources subject to emissions reporting...requirements for reporting emissions data under the plan are in...

2010-07-01

236

Source Apportionments of Air Pollutant Emissions Sources for "Air Quality Improvement Plan" in Seoul Metropolitan Area, Korea  

NASA Astrophysics Data System (ADS)

To setup a better air quality improvement plan, we need to understand exactly how emission from each source type such as area, mobile, and point sources, including biogenic emissions influences on air pollutant concentrations. The primary goal of this study is to estimate high order sensitivity coefficients to explain non-linearity characteristics in air pollution phenomena such as ozone and particulate matters to predict their changes associated with changes in their emissions and precursors to understand the relationship between emissions and concentrations. In order to investigate influences of emissions from a region and a source type on air pollutant concentrations over the Seoul metropolitan area in the study and contributions of air pollutant species and their transports between two regions, simulations using CMAQ HDDM are planed to have the first and second sensitivity coefficients which will be used to predict air pollutant concentrations corresponding to emissions changes in future urban and air quality implementation plans. It is also expected that how air pollutants emitted from Seoul affect air quality over Kyounggi and Incheon, how emission from each source type influences on air pollutant concentrations, and contributions of different chemical species like NOx and VOC on ozone and particulate matter concentrations for a region of interest. Acknowledgements This research was supported by the project, "KEI-2007-RE-19".-

Moon, N.; Kim, S.; Byun, D. W.

2009-04-01

237

A Novel Multifunctional Photocatalytic Oxidation (PCO) Gel Preventing Mold\\/Mildew Growth and Volatile Organic Compound (VOC) Emission  

Microsoft Academic Search

With the increasing time people spend indoors, the indoor environment quality draws more and more attention. The concentration of indoor pollutants is usually much higher than outdoors, in which volatile organic compounds (VOCs) and mold\\/mildew are both major pollutants and cause many health problems to residents. Efforts devoted from academy and industry to protecting people from indoor environment problems are

Yao Gao

2011-01-01

238

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...

239

Predicting the emission of volatile organic compounds from silage systems  

Technology Transfer Automated Retrieval System (TEKTRAN)

As a precursor to smog, emission of volatile organic compounds (VOCs) to the atmosphere is an environmental concern in some regions. The major VOC emission source from farms is silage, with emissions coming from the silo face, mixing wagon, and feed bunk. The major compounds emitted are alcohols wit...

240

CONTROLLING NOX EMISSION FROM INDUSTRIAL SOURCES  

EPA Science Inventory

A number of regulatory actions focused on reducing NOx emissions from stationary combustion sources have been taken in the United States in the last decade. These actions include the Acid Rain NOx regulations, the Ozone Transport Commission's NOx ...

241

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...

242

Customizing a VOC control technology  

SciTech Connect

An extremely important but very difficult element in applying an emission control device to an exhaust stream is to chose the proper technology. Once it has been determined that recovery, rather than destruction, is appropriate, there are still several process choices available. The type of process is generally dictated by the VOC concentration and total air flow rate. Adsorption is usually chosen for low concentrations and high flow rates while refrigeration is usually best for high concentrations and low flow rates. This paper describes six applications. Adsorption was applied to two of them and condensation to the other four. Solvent vapors from a tape coating operation are recovered in an activated carbon adsorption process and reused. VOC`s from soil vapor extraction operations are captured by activated carbon which is regenerated by a mobile unit. VOC`s displaced from filling tank cars at a refinery are condensed at low temperatures in a high pressure system which uses a pressure swing dryer to remove water. Two different processes were installed to prevent VOC emissions from pharmaceutical processing plants. They both use a thermal swing dryer to remove moisture and low temperature condensation to recover the solvent. With very high concentrations of solvent in an inert gas stream, indirect condensation is used to purify the nitrogen and recover the solvent for reuse. Process flow diagrams and operating results are presented.

Enneking, J.C.

1998-12-31

243

SOURCE ASSESSMENT: ACRYLONITRILE MANUFACTURE (AIR EMISSIONS)  

EPA Science Inventory

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 plant, based on field samp...

244

SOURCE ASSESSMENT: PHTHALIC ANHYDRIDE (AIR EMISSIONS)  

EPA Science Inventory

The report gives results of an analysis of atmospheric (air) emissions from ortho-xylene- and naphthalene-based phthalic anhydride manufacturing plants. Uncontrolled and controlled emission factors are given for each species emitted to the atmosphere from each source within a typ...

245

Radiation source with shaped emission  

DOEpatents

Employing a source of radiation, such as an electric discharge source, that is equipped with a capillary region configured into some predetermined shape, such as an arc or slit, can significantly improve the amount of flux delivered to the lithographic wafers while maintaining high efficiency. The source is particularly suited for photolithography systems that employs a ringfield camera. The invention permits the condenser which delivers critical illumination to the reticle to be simplified from five or more reflective elements to a total of three or four reflective elements thereby increasing condenser efficiency. It maximizes the flux delivered and maintains a high coupling efficiency. This architecture couples EUV radiation from the discharge source into a ring field lithography camera.

Kubiak, Glenn D.; Sweatt, William C.

2003-05-13

246

CRITICAL EVALUATION OF THE DIFFUSION HYPOTHESIS IN THE THEORY OF POROUS MEDIA VOLATILE ORGANIC COMPOUND (VOC) SOURCES AND SINKS  

EPA Science Inventory

The paper proposes three alternative, diffusion-limited mathematical models to account for volatile organic compound (VOC) interactions with indoor sinks, using the linear isotherm model as a reference point. (NOTE: Recent reports by both the U.S. EPA and a study committee of the...

247

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

248

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

249

Modeling Secondary Organic Aerosol Formation From Emissions of Combustion Sources  

NASA Astrophysics Data System (ADS)

Atmospheric aerosols exert a large influence on the Earth's climate and cause adverse public health effects, reduced visibility and material degradation. Secondary organic aerosol (SOA), defined as the aerosol mass arising from the oxidation products of gas-phase organic species, accounts for a significant fraction of the submicron atmospheric aerosol mass. Yet, there are large uncertainties surrounding the sources, atmospheric evolution and properties of SOA. This thesis combines laboratory experiments, extensive data analysis and global modeling to investigate the contribution of semi-volatile and intermediate volatility organic compounds (SVOC and IVOC) from combustion sources to SOA formation. The goals are to quantify the contribution of these emissions to ambient PM and to evaluate and improve models to simulate its formation. To create a database for model development and evaluation, a series of smog chamber experiments were conducted on evaporated fuel, which served as surrogates for real-world combustion emissions. Diesel formed the most SOA followed by conventional jet fuel / jet fuel derived from natural gas, gasoline and jet fuel derived from coal. The variability in SOA formation from actual combustion emissions can be partially explained by the composition of the fuel. Several models were developed and tested along with existing models using SOA data from smog chamber experiments conducted using evaporated fuel (this work, gasoline, fischertropschs, jet fuel, diesels) and published data on dilute combustion emissions (aircraft, on- and off-road gasoline, on- and off-road diesel, wood burning, biomass burning). For all of the SOA data, existing models under-predicted SOA formation if SVOC/IVOC were not included. For the evaporated fuel experiments, when SVOC/IVOC were included predictions using the existing SOA model were brought to within a factor of two of measurements with minor adjustments to model parameterizations. Further, a volatility-only model suggested that differences in the volatility of the precursors were able to explain most of the variability observed in the SOA formation. For aircraft exhaust, the previous methods to simulate SOA formation from SVOC and IVOC performed poorly. A more physically-realistic modeling framework was developed, which was then used to show that SOA formation from aircraft exhaust was (a) higher for petroleum-based than synthetically derived jet fuel and (b) higher at lower engine loads and vice versa. All of the SOA data from combustion emissions experiments were used to determine source-specific parameterizations to model SOA formation from SVOC, IVOC and other unspeciated emissions. The new parameterizations were used to investigate their influence on the OA budget in the United States. Combustion sources were estimated to emit about 2.61 Tg yr-1 of SVOC, 1VOC and other unspeciated emissions (sixth of the total anthropogenic organic emissions), which are predicted to double SOA production from combustion sources in the United States. The contribution of SVOC and IVOC emissions to global SOA formation was assessed using a global climate model. Simulations were performed using a modified version of GISS GCM 11'. The modified model predicted that SVOC and IVOC contributed to half of the OA mass in the atmosphere. Their inclusion improved OA model-measurement comparisons for absolute concentrations, POA-SOA split and volatility (gas-particle partitioning) globally suggesting that atmospheric models need to incorporate SOA formation from SVOC and IVOC if they are to reasonably predict the abundance and properties of aerosols. This thesis demonstrates that SVOC/IVOC and possibly other unspeciated organics emitted by combustion sources are very important precursors of SOA and potentially large contributors to the atmospheric aerosol mass. Models used for research and policy applications need to represent them to improve model-predictions of aerosols on climate and health outcomes. The improved modeling frameworks developed in this dissertation are suitable for implementa

Jathar, Shantanu Hemant

250

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...

251

Comprehensive source apportionment of volatile organic compounds using observational data, two receptor models, and an emission inventory in Tokyo metropolitan area  

NASA Astrophysics Data System (ADS)

Source contributions of volatile organic compounds (VOCs) were comprehensively evaluated using an observational data set, two receptor models, and an emission inventory. Hourly concentrations of C2-C8 nonmethane hydrocarbons (NMHCs) were measured at Saitama, which is near the northern edge of Tokyo, throughout 2007. Estimates of background NMHC concentrations at the Saitama site corresponded well with median NMHC concentrations at a remote island in Japan in winter and spring. Source contributions of ?NMHCs (differences between ambient and background concentrations) calculated by the chemical mass balance (CMB) model and positive matrix factorization (PMF) corresponded with each other within a factor of 2. The two receptor models estimated that vehicle exhaust, gasoline vapor, liquefied natural gas and liquefied petroleum gas (LPG), and other evaporative sources contributed 14%-25%, 9%-16%, 7%-10%, and 49%-71%, respectively, to total VOC concentrations on a mass basis. These values agreed with the emission inventory except for the LPG values. In addition, the CMB and PMF results explained at least two thirds of the observed total ?NMHC values. These results suggest that the current emission inventory roughly captures the individual contributions and total amount of VOC emissions. However, characterization of background NMHCs is necessary to fully understand the VOC budget.

Morino, Y.; Ohara, T.; Yokouchi, Y.; Ooki, A.

2011-01-01

252

77 FR 28375 - Adequacy Status of the Submitted 2008 and 2022 VOC and NOX  

Federal Register 2010, 2011, 2012, 2013, 2014

...2008 and 2022 VOC and NOX Motor Vehicle Emissions Budgets for Transportation...MOVES2010 motor vehicle emissions budgets (MVEBs) in...Adequate Motor Vehicle Emissions Budgets...VOC (tons per NOX (tons per summer...

2012-05-14

253

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...

254

Do vehicular emissions dominate the source of C6-C8 aromatics in the megacity Shanghai of eastern China?  

PubMed

The characteristic ratios of volatile organic compounds (VOCs) to i-pentane, the indicator of vehicular emissions, were employed to apportion the vehicular and non-vehicular contributions to reactive species in urban Shanghai. Two kinds of tunnel experiments, one tunnel with more than 90% light duty gasoline vehicles and the other with more than 60% light duty diesel vehicles, were carried out to study the characteristic ratios of vehicle-related emissions from December 2009 to January 2010. Based on the experiments, the characteristic ratios of C6-C8 aromatics to i-pentane of vehicular emissions were 0.53±0.08 (benzene), 0.70±0.12 (toluene), 0.41±0.09 (m,p-xylenes), 0.16±0.04 (o-xylene), 0.023±0.011 (styrene), and 0.15±0.02 (ethylbenzene), respectively. The source apportionment results showed that around 23.3% of C6-C8 aromatics in urban Shanghai were from vehicular emissions, which meant that the non-vehicular emissions had more importance. These findings suggested that emission control of non-vehicular sources, i.e. industrial emissions, should also receive attention in addition to the control of vehicle-related emissions in Shanghai. The chemical removal of VOCs during the transport from emissions to the receptor site had a large impact on the apportionment results. Generally, the overestimation of vehicular contributions would occur when the VOC reaction rate constant with OH radicals (kOH) was larger than that of the vehicular indicator, while for species with smaller kOH than the vehicular indicator, the vehicular contribution would be underestimated by the method of characteristic ratios. PMID:25597688

Wang, Hongli; Wang, Qian; Chen, Jianmin; Chen, Changhong; Huang, Cheng; Qiao, Liping; Lou, Shengrong; Lu, Jun

2015-01-01

255

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

EPA Science Inventory

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

256

[Evaluation of volatile organic compounds (VOCs) emitted from household products by small chamber test method].  

PubMed

Identification and removal/replacement of sources of indoor air pollutants, such as volatile organic compounds (VOCs) and aldehydes, are most effective measures to reduce indoor chemical exposures. For instance, formaldehyde emissions from building materials have been successfully decreased by the restrictions on interior finishing materials under the amended Building Standard Low in Japan. This study was performed to estimate quantitatively influence of household products on indoor air quality. VOC emissions were investigated for 51 products including interior materials, bedclothes, stationeries, toys and printed matters by the small chamber test method (JIS A 1901) under the standard conditions of 28 degrees C, 50% relative humidity and 0.5 times/h ventilation. Total VOC (TVOC) emissions from the tablecloth and gloves, both of which were made of polyvinyl chloride, showed the highest emission rates; over 2000 microg/(m2 x h) after 1 day, and then rapidly decreased to less than 500 microg/(m2 x h) in a week. Among stationeries/toys for schoolchildren and infants, jigsaw puzzle and play mat exhibited higher TVOC emission rates (38 and 24 microg/(m2 x h) after 1 day, respectively). As for VOCs emitted from printed matters, high boiling-point compounds (higher than that of n-tridecane) were typically identified along with toluene, xylenes and ethylbenzene. These results revealed that VOC emissions from household products may influence significantly indoor air quality. PMID:18220050

Tanaka-Kagawa, Toshiko; Jinno, Hideto; Obama, Tomoko; Miyagawa, Makoto; Yoshikawa, Jun; Komatsu, Kazuhiro; Tokunaga, Hiroshi

2007-01-01

257

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

258

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

259

40 CFR 80.45 - Complex emissions model.  

Code of Federal Regulations, 2014 CFR

...The exhaust VOC emissions performance of gasolines shall be given by...winter exhaust VOC emissions performance of gasolines shall be given...The nonexhaust VOC emissions performance of gasolines in VOC Control...

2014-07-01

260

40 CFR 80.45 - Complex emissions model.  

Code of Federal Regulations, 2010 CFR

...The exhaust VOC emissions performance of gasolines shall be given by...winter exhaust VOC emissions performance of gasolines shall be given...The nonexhaust VOC emissions performance of gasolines in VOC Control...

2010-07-01

261

40 CFR 80.45 - Complex emissions model.  

Code of Federal Regulations, 2013 CFR

...The exhaust VOC emissions performance of gasolines shall be given by...winter exhaust VOC emissions performance of gasolines shall be given...The nonexhaust VOC emissions performance of gasolines in VOC Control...

2013-07-01

262

40 CFR 80.45 - Complex emissions model.  

Code of Federal Regulations, 2012 CFR

...The exhaust VOC emissions performance of gasolines shall be given by...winter exhaust VOC emissions performance of gasolines shall be given...The nonexhaust VOC emissions performance of gasolines in VOC Control...

2012-07-01

263

40 CFR 80.45 - Complex emissions model.  

Code of Federal Regulations, 2011 CFR

...The exhaust VOC emissions performance of gasolines shall be given by...winter exhaust VOC emissions performance of gasolines shall be given...The nonexhaust VOC emissions performance of gasolines in VOC Control...

2011-07-01

264

Temperature dependence of volatile organic compound evaporative emissions from motor vehicles  

E-print Network

summer 2001. Additional gasoline- related VOC emissions not shown in Figure 1 occur at service stationsTemperature dependence of volatile organic compound evaporative emissions from motor vehicles Juli tailpipe sources to motor vehicle volatile organic compound (VOC) emissions. Contributions were determined

Silver, Whendee

265

Coherent emission of light by thermal sources.  

PubMed

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 case with many systems, different behaviour can be expected on a microscopic scale. It has been shown recently that the field emitted by a thermal source made of a polar material is enhanced by more than four orders of magnitude and is partially coherent at a distance of the order of 10 to 100nm. Here we demonstrate that by introducing a periodic microstructure into such a polar material (SiC) a thermal infrared source can be fabricated that is coherent over large distances (many wavelengths) and radiates in well defined directions. Narrow angular emission lobes similar to antenna lobes are observed and the emission spectra of the source depends on the observation angle--the so-called Wolf effect. The origin of the coherent emission lies in the diffraction of surface-phonon polaritons by the grating. PMID:11882890

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

2002-03-01

266

Evaluation of low-VOC latex paints  

SciTech Connect

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 analysis indicated that the VOC contents of all four paints are considerably lower than those of conventional latex paints. Low-VOC emissions were confirmed by small chamber emission tests. However, sigificant emissions of several aldehydes, especially formaldehyde, were detected from two of the paints. ASTM methods were used to evaluate the hiding power, scrubbability, washability, dry to touch, and yellowing index. The results indicated that one of the low-VOC paints tested showed performance equivalent or superior to that of a widely used conventional latex paint used as a control. It was concluded that low-VOC latex paint can be a viable option to replace conventional latex paints for prevention of indoor air pollution. However, paints marketed as low-VOC may still have significant emissions of some individual VOCs, and some may not have performance characteristics matching those of conventional latex paints.

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

1999-01-01

267

Evaluation of low-VOC latex paints  

SciTech Connect

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 analysis indicated that the VOC contents of all four paints are considerably lower than those of conventional latex paints. Low-VOC emissions were confirmed by small chamber emission tests. However, sigificant emissions of several aldehydes, especially formaldehyde, were detected from two of the paints. ASTM methods were used to evaluate the hiding power, scrubbability, washability, dry to touch, and yellowing index. The results indicated that one of the low-VOC paints tested showed performance equivalent or superior to that of a widely used conventional latex paint used as a control. It was concluded that low-VOC latex paint can be a viable option to replace conventional latex paints for prevention of indoor air pollution. However, paints marketed as low-VOC may still have significant emissions of some individual VOCs, and some may not have performance characteristics matching those of conventional latex paints.

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

1999-11-01

268

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

269

NOVEL NANOPARTICULATE CATALYSTS FOR IMPROVED VOC TREATMENT DEVICES - PHASE I  

EPA Science Inventory

Catalytic oxidation of VOCs is increasingly used for treatment of large-volume emissions at relatively dilute VOC levels. The best performing catalytic oxidation devices for attainment of very high VOC destruction levels employ precious metal catalysts, the costs of which a...

270

Nitrogen Source Effects on Nitrous Oxide Emissions  

Technology Transfer Automated Retrieval System (TEKTRAN)

Effects of N fertilizer source and tillage on nitrous oxide (N2O) emissions from soils under several irrigated, crop management systems were evaluated. Irrigated corn production systems [conventional-till continuous corn (CT-CC); no-till continuous corn (NT-CC); NT corn-dry bean (NT-CDb); and NT cor...

271

Observation and modelling of OH and HO2 concentrations in Beijing and Pearl River Delta summer 2006: missing OH source in VOC rich atmosphere  

NASA Astrophysics Data System (ADS)

Ambient OH and HO2 concentrations were measured by laser induced fluorescence (LIF) during the PRIDE-PRD2006 (Program of Regional Integrated Experiments of Air Quality over the Pearl River Delta, 2006) and the CAREBEIJING2006 (Campaigns of Air Quality Research in Beijing and Surrounding Region, 2006) campaigns at rural sites close to the megacities of Guangzhou and Beijing, respectively. In PRD, the observed daily maximum OH and HO2 concentrations reached daily peak values of (15~--~26)±106 cm-3 and (3~--~25)±108 cm-3, respectively. In Beijing, the corresponding values were about (4~--~17)±106 cm-3 and (2~--~24)±108 cm-3. At both sites, the measured OH concentrations were much higher than can be explained by current chemical box models when NOx is low, pointing to a missing OH source in VOC rich air. In this presentation, we report the observed and modelled HOx concentrations, depict the general feature of the HOx system through an empirical analysis, and examine different mechanistic proposals to explain the missing OH source (Hofzumahaus et al. 2009; Lu et al., 2011). Overall, we conclude that a missing OH recycling of type HO2->OH is required for these VOC rich air masses in the transient regime between biogenic and urban influences. Recently published mechanistic updates of isoprene chemistry (e.g. MIM2+ and LIM0) developed for forest regions are not able to reproduce the observed OH in both PRD and Beijing.

Lu, K.; Rohrer, F.; Holland, F.; Fuchs, H.; Bohn, B.; Brauers, T.; Chang, C.; Hu, M.; Kita, K.; Kondo, Y.; Li, X.; Lou, S.; Oebel, A.; Shao, M.; Zeng, L.; Zhu, T.; Wahner, A.; Zhang, Y.; Hofzumahaus, A.

2011-12-01

272

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

273

EVALUATION OF LOW-VOC LATEX PAINTS  

EPA Science Inventory

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 analysis indicated that ...

274

Long-term trends in california mobile source emissions and ambient concentrations of black carbon and organic aerosol.  

PubMed

A fuel-based approach is used to assess long-term trends (1970-2010) in mobile source emissions of black carbon (BC) and organic aerosol (OA, including both primary emissions and secondary formation). The main focus of this analysis is the Los Angeles Basin, where a long record of measurements is available to infer trends in ambient concentrations of BC and organic carbon (OC), with OC used here as a proxy for OA. Mobile source emissions and ambient concentrations have decreased similarly, reflecting the importance of on- and off-road engines as sources of BC and OA in urban areas. In 1970, the on-road sector accounted for ?90% of total mobile source emissions of BC and OA (primary + secondary). Over time, as on-road engine emissions have been controlled, the relative importance of off-road sources has grown. By 2010, off-road engines were estimated to account for 37 ± 20% and 45 ± 16% of total mobile source contributions to BC and OA, respectively, in the Los Angeles area. This study highlights both the success of efforts to control on-road emission sources, and the importance of considering off-road engine and other VOC source contributions when assessing long-term emission and ambient air quality trends. PMID:25793355

McDonald, Brian C; Goldstein, Allen H; Harley, Robert A

2015-04-21

275

The impact of speciated VOCs on regional ozone increment derived from measurements at the UK EMEP supersites between 1999 and 2012  

NASA Astrophysics Data System (ADS)

The impact of 27 volatile organic compounds (VOC) on the regional O3 increment was investigated using measurements made at the UK EMEP supersites Harwell (1999-2001 and 2010-2012) and Auchencorth (2012). Ozone at these sites is representative of rural O3 in south-east England and northern UK, respectively. Monthly-diurnal regional O3 increment was defined as the difference between the regional and hemispheric background O3 concentrations, respectively derived from oxidant vs. NOx correlation plots, and cluster analysis of back trajectories arriving at Mace Head, Ireland. At Harwell, which had substantially greater regional ozone increments than at Auchencorth, variation in the regional O3 increment mirrored afternoon depletion of VOCs due to photochemistry (after accounting for diurnal changes in boundary layer mixing depth, and weighting VOC concentrations according to their photochemical ozone creation potential). A positive regional O3 increment occurred consistently during the summer, during which time afternoon photochemical depletion was calculated for the majority of measured VOCs, and to the greatest extent for ethene and m + p-xylene. This indicates that, of the measured VOCs, ethene and m + p-xylene emissions reduction would be most effective in reducing the regional O3 increment, but that reductions in a larger number of VOCs would be required for further improvement. The VOC diurnal photochemical depletion was linked to the sources of the VOC emissions through the integration of gridded VOC emissions estimates over 96 h air-mass back trajectories. This demonstrated that the effectiveness of VOC gridded emissions for use in measurement and modelling studies is limited by the highly aggregated nature of the 11 SNAP source sectors in which they are reported, as monthly variation in speciated VOC trajectory emissions did not reflect monthly changes in individual VOC diurnal photochemical depletion. Additionally, the major VOC emission source sectors during elevated regional O3 increment at Harwell were more narrowly defined through disaggregation of the SNAP emissions to 91 NFR codes (i.e. sectors 3D2 (domestic solvent use), 3D3 (other product use) and 2D2 (food and drink)). However, spatial variation in the contribution of NFR sectors to parent SNAP emissions could only be accounted for at the country level. Hence, the future reporting of gridded VOC emissions in source sectors more highly disaggregated than currently (e.g. to NFR codes) would facilitate a more precise identification of those VOC sources most important for mitigation of the impact of VOCs on O3 formation. In summary, this work presents a clear methodology for achieving a coherent VOC regional-O3-impact chemical climate using measurement data and explores the effect of limited emission and measurement species on the understanding of the regional VOC contribution to O3 concentrations.

Malley, C. S.; Braban, C. F.; Dumitrean, P.; Cape, J. N.; Heal, M. R.

2015-03-01

276

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

EPA Science Inventory

The report gives results of the collection of emissions test data st two triethylene glycol units to provide data for the comparison to GRI-GLYCalc, a computer program developed to estimate emissions from glycol dehydrators. [NOTE: Glycol dehydrators are used in the natural gas i...

277

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

EPA Science Inventory

The report gives results of the collection of emissions tests data at two triethylene glycol 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 gas indu...

278

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...

279

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...

280

Impacts of seasonal and regional variability in biogenic VOC emissions on surface ozone in the Pearl River Delta region, China  

SciTech Connect

In this study, the BVOC emissions in November 2010 over the Pearl River Delta (PRD) region in southern China have been estimated by the latest version of a Biogenic Volatile Organic Compound (BVOC) emission model (MEGAN v2.1). The evaluation of MEGAN performance at a representative forest site within this region indicates MEGAN can estimate BVOC emissions reasonably well in this region except overestimating isoprene emission in autumn for reasons that are discussed in this manuscript. Along with the output from MEGAN, the Weather Research and Forecasting model with chemistry (WRF-Chem) is used to estimate the impacts of BVOC emissions on surface ozone in the PRD region. The results show BVOC emissions increase the daytime ozone peak by *3 ppb on average, and the max hourly impacts of BVOC emissions on the daytime ozone peak is 24.8 ppb. Surface ozone mixing ratios in the central area of Guangzhou- Foshan and the western Jiangmen are most sensitive to BVOC emissions BVOCs from outside and central PRD influence the central area of Guangzhou-Foshan and the western Jiangmen significantly while BVOCs from rural PRD mainly influence the western Jiangmen. The impacts of BVOC emissions on surface ozone differ in different PRD cities, and the impact varies in different seasons. Foshan and Jiangmen being most affected in autumn, result in 6.0 ppb and 5.5 ppb increases in surface ozone concentrations, while Guangzhou and Huizhou become more affected in summer. Three additional experiments concerning the sensitivity of surface ozone to MEGAN input variables show that surface ozone is more sensitive to landcover change, followed by emission factors and meteorology.

Situ, S.; Guenther, Alex B.; Wang, X. J.; Jiang, X.; Turnipseed, A.; Wu, Z.; Bai, J.; Wang, X.

2013-12-05

281

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

282

Removal of volatile organic compounds (VOC`s) generated by Forest Product Industries using biofiltration technology  

SciTech Connect

Implementation of Clean Air Act Title V and the increasing environmental concerns of the public are imposing greater demands on the Forest Product industries to control their air emissions. As implementation of this Clean Air Act has begun, Forest Product Industries are recognizing the overall lack of historical emissions data, emissions testing information and knowledge of the economics of emission control technologies needed to reduce emissions. This study was undertaken to evaluate the types of VOC`s produced in drying and pressing wood composites, and determine how effective biofiltration technology could be used in reducing the levels of these products before they are released into the air. More specifically, the experiments were conducted to isolate microorganisms capable of degrading VOC`s and determine their biodegradation rates using bench scale biofilters.

Gilliland, G.A. [Eastman Chemical Company, Longview, TX (United States); Ramaswami, R.D.; Patel, D.N. [Grant Environmental, Englewood, CO (United States)] [and others

1995-12-31

283

Truckee Meadows PM and VOC apportionment study: Winter 1997  

SciTech Connect

An ambient monitoring and source apportionment study was carried out in the Truckee Meadows area of northern Nevada in the winter of 1997. The goal was to measure ambient levels of PM10, PM2.5, and volatile organic compounds (VOCs) and determine the relative importance of their contributing sources. Two monitoring stations, one in the downtown Reno area (urban) and the other in Sparks (residential), collected ten 24-hour samples, on a one-in-six schedule. A total of twenty PM10 (Reno and Sparks), ten PM2.5 (Sparks), and ten VOC/canister and semi-volatile/Tenax (Reno) samples were obtained. Particle samples were analyzed for mass, organic/elemental carbon, ions, ammonium, and metals. Canister samples were analyzed for C2 to C12 hydrocarbons, while Tenax cartridges were analyzed for C8 to C20 hydrocarbons. Chemical mass balance (CMB) receptor modeling was performed on both the inorganic and organic data to estimate the contributions from different sources to the observed ambient concentrations. PM2.5 comprised roughly 50% of the PM10 concentration in the Sparks area. At the downtown Reno site, geological sources, such as resuspended road dust, construction sites and unpaved roads, contributed on average about 70% of the average PM10, while the Sparks geological contribution was about 55% of the average PM10. Other major PM10 sources included motor vehicles, wood smoke, and secondary sources (ammonium sulfate and ammonium nitrate). PM2.5 was dominated by almost equal contributions from motor vehicles and wood smoke. The results are in contrast to a 1986 study, which found greater relative contributions from motor vehicles and wood burning to the observed PM10. The VOC apportionment found that the sampling site was heavily influenced by mobile source emissions, with an average sum of gasoline-vehicle exhaust, diesel exhaust, and headspace vapor of 77% of the total VOCs.

Gofa, F.; Gertler, A.W. [Desert Research Institute, Reno, NV (United States). Energy and Environmental Engineering Center; Jennison, B.; Goodrich, A. [Washoe County District Health Dept., Reno, NV (United States). Air Quality Management Div.

1998-12-31

284

40 CFR 60.694 - Permission to use alternative means of emission limitation.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for VOC Emissions From Petroleum Refinery Wastewater Systems § 60.694 Permission to use alternative means of emission limitation. (a) If, in the...

2013-07-01

285

Endocrine disrupting chemical emissions from combustion sources: diesel particulate emissions and domestic waste open burn emissions  

NASA Astrophysics Data System (ADS)

Emissions of endocrine disrupting chemicals (EDCs) from combustion sources are poorly characterized due to the large number of compounds present in the emissions, the complexity of the analytical separations required, and the uncertainty regarding identification of chemicals with endocrine effects. In this work, multidimensional gas chromatographic-mass spectrometry (MDGC-MS) was used to characterize emissions from both controlled (diesel engine) and uncontrolled (open burning of domestic waste) combustion sources. The results of this study suggest that, by using MDGC-MS, one can resolve a much greater percentage of the chromatogram and identify about 84% of these resolved compounds. This increase in resolution helped to identify and quantify various classes of polycyclic aromatic hydrocarbons (PAHs) in the combustion emissions that had not been identified previously. Significant emissions (when compared to industrial sources) of known EDCs, dioctyl phthalate (over ˜2,500,000 kg year -1) and bisphenol A (over ˜75,000 kg year -1) were estimated from uncontrolled domestic waste burning. Emissions of several suspected EDCs (oxygenated PAHs) were observed in both diesel soot and the uncontrolled domestic waste burn samples. The emission rates of known and suspected EDCs estimated in this study suggest that combustion emissions need to be characterized for EDCs to further assess its importance as a source of EDC exposure.

Sidhu, Sukh; Gullett, Brian; Striebich, Richard; Klosterman, Joy; Contreras, Jesse; DeVito, Michael

286

The Sensitivity of U.S. Surface Ozone Formation to NOx, and VOCs as Viewed from Space  

NASA Technical Reports Server (NTRS)

We investigated variations in the sensitivity of surface ozone formation in summer to precursor species concentrations of volatile organic compounds (VOCs) and nitrogen oxides (NO(x)) as inferred from the ratio of tropospheric columns of formaldehyde and nitrogen dioxide from the Aura Ozone Monitoring Instrument (OMI). The data indicate that ozone formation became: 1. more sensitive to NO(x) over most of the U.S, from 2005 to 2007 because of substantial decreases in NO(x) emissions primarily from stationary sources, and 2. more sensitive to NO(x) with increasing temperature, in part because emissions of highly reactive, biogenic isoprene increase with temperature, thus increasing the total VOC reactivity. Based on our interpretation of the data, current strategies implemented to reduce unhealthy levels of surface ozone should focus more on reducing NO(x) emissions, except in some downtown areas which have historically benefited from reductions in VOC emissions.

Duncan, Bryan N.; Yoshida, Yasuko; Sillman, Sanford; Retscher, Christian; Pickering, Kenneth E.; Martin, Randall V.; Celarier, Edward A.

2009-01-01

287

Simulated changes in biogenic VOC emissions and ozone formation from habitat expansion of Acer Rubrum (red maple)  

NASA Astrophysics Data System (ADS)

A new vegetation trend is emerging in northeastern forests of the United States, characterized by an expansion of red maple at the expense of oak. This has changed emissions of biogenic volatile organic compounds (BVOCs), primarily isoprene and monoterpenes. Oaks strongly emit isoprene while red maple emits a negligible amount. This species shift may impact nearby urban centers because the interaction of isoprene with anthropogenic nitrogen oxides can lead to tropospheric ozone formation and monoterpenes can lead to the formation of particulate matter. In this study the Global Biosphere Emissions and Interactions System was used to estimate the spatial changes in BVOC emission fluxes resulting from a shift in forest composition between oak and maple. A 70% reduction in isoprene emissions occurred when oak was replaced with maple. Ozone simulations with a chemical box model at two rural and two urban sites showed modest reductions in ozone concentrations of up to 5-6 ppb resulting from a transition from oak to red maple, thus suggesting that the observed change in forest composition may benefit urban air quality. This study illustrates the importance of monitoring and representing changes in forest composition and the impacts to human health indirectly through changes in BVOCs.

Drewniak, Beth A.; Snyder, Peter K.; Steiner, Allison L.; Twine, Tracy E.; Wuebbles, Donald J.

2014-01-01

288

DEVELOPMENT OF LASER-BASED SENSORS FOR VOC/NOX AND METALS EMISSIONS MONITORING, CP 1060-97  

EPA Science Inventory

This project addresses the growing Department of Defense (DoD) and Department of Energy (DOE) needs to monitor air emissions in order to comply with more stringent regulatory pressures, such as the Clean Air Act Amendment (CAAA). Specifically, we are focused on the development of...

289

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

2007-09-01

290

Global data set of biogenic VOC emissions calculated by the MEGAN model over the last 30 years  

NASA Astrophysics Data System (ADS)

The Model of Emissions of Gases and Aerosols from Nature (MEGANv2.1) together with the Modern-Era Retrospective Analysis for Research and Applications (MERRA) meteorological fields were used to create a global emission data set of biogenic volatile organic compounds (BVOC) available on a monthly basis for the time period of 1980-2010. This data set, developed under the Monitoring Atmospheric Composition and Climate project (MACC), is called MEGAN-MACC. The model estimated mean annual total BVOC emission of 760 Tg (C) yr-1 consisting of isoprene (70%), monoterpenes (11%), methanol (6%), acetone (3%), sesquiterpenes (2.5%) and other BVOC species each contributing less than 2%. Several sensitivity model runs were performed to study the impact of different model input and model settings on isoprene estimates and resulted in differences of up to ±17% of the reference isoprene total. A greater impact was observed for a sensitivity run applying parameterization of soil moisture deficit that led to a 50% reduction of isoprene emissions on a global scale, most significantly in specific regions of Africa, South America and Australia. MEGAN-MACC estimates are comparable to results of previous studies. More detailed comparison with other isoprene inventories indicated significant spatial and temporal differences between the data sets especially for Australia, Southeast Asia and South America. MEGAN-MACC estimates of isoprene, ?-pinene and group of monoterpenes showed a reasonable agreement with surface flux measurements at sites located in tropical forests in the Amazon and Malaysia. The model was able to capture the seasonal variation of isoprene emissions in the Amazon forest.

Sindelarova, K.; Granier, C.; Bouarar, I.; Guenther, A.; Tilmes, S.; Stavrakou, T.; Müller, J.-F.; Kuhn, U.; Stefani, P.; Knorr, W.

2014-09-01

291

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

292

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

293

Chemical loss of volatile organic compounds and its impact on the source analysis through a two-year continuous measurement  

NASA Astrophysics Data System (ADS)

Chemical loss of volatile organic compounds (VOCs) is more important than the observed VOCs, which is the real actor of the chemical process in the atmosphere. The chemical loss of VOCs might impact on the identification of VOCs sources in ambient. For this reason, VOCs with 56 species were continuously measured in the urban area of Shanghai from 2009 to 2010, and based on the measurement the chemical loss of VOCs was calculated. According to the result, the initial VOCs in Shanghai urban was (34.8 ± 20.7) ppbv, higher than the observed one by ?35%, including alkanes (?38%), aromatics (?36%), alkenes (?17%), and acetylene (?8%). The chemical reactivity of VOCs would be underestimated by ?60% if the chemical loss were ignored. The chemical loss of VOCs showed a good agreement with Ox (O3 + NO2). C7-C8 aromatics and C3-C5 alkenes contributed ?60% of consumed VOCs. Seven sources were identified and quantified from positive matrix factorization (PMF) analysis. Vehicular emissions were the largest anthropogenic source of VOCs in Shanghai urban, accounting for 27.6% of VOCs, followed by solvent usage (19.4%), chemical industry (13.2%), petrochemical industry (9.1%), and coal burning (?5%). The contribution of biogenic emissions to total VOCs was 5.8%. Besides the five local anthropogenic sources and one biogenic source, the regional transportation was identified as one important source, contributing about 20% of VOCs in Shanghai urban. Sources apportionment results from PMF analysis based on the initial VOCs showed some differences from those based on observed data and might be more appropriate to be applied into the formulation of air pollution control measures.

Wang, H. L.; Chen, C. H.; Wang, Q.; Huang, C.; Su, L. Y.; Huang, H. Y.; Lou, S. R.; Zhou, M.; Li, L.; Qiao, L. P.; Wang, Y. H.

2013-12-01

294

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

295

Source Apportionment of Stack Emissions from Research and Development Facilities Using Positive Matrix Factorization  

SciTech Connect

Emissions from research and development (R&D) facilities are difficult to characterize due to the wide variety of processes used, changing nature of research, and large number of chemicals. Positive matrix factorization (PMF) was applied to volatile organic compounds (VOCs) concentrations measured in the main exhaust stacks of four different R&D buildings to identify the number and composition of major contributing sources. PMF identified from 9-11 source-related factors contributing to the stack emissions depending on the building. The factors that were similar between buildings were major contributors to trichloroethylene (TCE), acetone, and ethanol emissions. Several other factors had similar profiles for two or more buildings but not for all four. One factor for each building was a combination of p/m-xylene, o-xylene and ethylbenzene. At least one factor for each building was identified that contained a broad mix of many species and constraints were used in PMF to modify the factors to resemble more closely the off-shift concentration profiles. PMF accepted the constraints with little decrease in model fit. Although the PMF model predicted the profiles of the off-shift samples, the percent of total emissions was under-predicted by the model versus the measured data.

Ballinger, Marcel Y.; Larson, Timothy V.

2014-12-01

296

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

297

Solutions for VOC and HAPS control on natural gas fired internal combustion engines  

SciTech Connect

Natural gas fired stationary internal combustion engines (IC engines) emit volatile organic compounds (VOC) and hazardous air pollutants (HAP) as part of their normal operations. VOC and HAP emissions are coming under increased scrutiny with the advent of such Clean Air Act Amendments of 1990 regulations as Title I`s Reasonably Available Control Technology (RACT), Title III`s Maximum Achievable Control Technology (MACT) and Title V`s Operating Permit Program (Title V). In addition, many states are imposing more stringent emission limits on these sources. These emissions may also contribute to the reportable chemicals from the total facility under SARA Title III. Numerous facilities nationwide are interested in reducing these emissions in order to comply with current requirements, to opt out of requirements or to reduce reportable chemicals. This paper will examine the source of these emissions, and discuss combustion control technologies and system operating flexibility, end-of-pipe control technologies, and system tuning opportunities which have the potential to reduce VOC and HAP emissions from IC engines. Data will be presented on potential emission reduction efficiencies achievable using the various control options. 7 refs., 4 tabs.

Marcus, J.Z. [Enviroplan, Inc., Roseland, NJ (United States); Sleigh, S. [CNG Transmission Corp., Clarksburg, WV (United States); Cotherman, R. [ENOx Technologies, Inc., Natick, MA (United States)

1996-12-31

298

Characterization and source apportionment of volatile organic compounds in urban and suburban Tianjin, China  

NASA Astrophysics Data System (ADS)

Tianjin is the third largest megacity and the fastest growth area in China, and consequently faces the problems of surface ozone and haze episodes. This study measures and characterizes volatile organic compounds (VOCs), which are ozone precursors, to identify their possible sources and evaluate their contribution to ozone formation in urban and suburban Tianjin, China during the HaChi (Haze in China) summer campaign in 2009. A total of 107 species of ambient VOCs were detected, and the average concentrations of VOCs at urban and suburban sites were 92 and 174 ppbv, respectively. Of those, 51 species of VOCs were extracted to analyze the possible VOC sources using positive matrix factorization. The identified sources of VOCs were significantly related to vehicular activities, which specifically contributed 60% to urban and 42% to suburban VOCs loadings in Tianjin. Industrial emission was the second most prominent source of ambient VOCs in both urban and suburban areas, although the contribution of industry in the suburban area (36%) was much higher than that at the urban area (16%). We conclude that controlling vehicle emissions should be a top priority for VOC reduction, and that fast industrialization and urbanization causes air pollution to be more complex due to the combined emission of VOCs from industry and daily life, especially in suburban areas.

Han, Meng; Lu, Xueqiang; Zhao, Chunsheng; Ran, Liang; Han, Suqin

2015-03-01

299

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

300

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

301

THE INTEGRATION MODELING FRAMEWORK FOR ESTIMATING MOBILE SOURCE EMISSIONS  

E-print Network

-following, vehicle dynamics, lane changing, energy, and emission models to estimate mobile source emissions directly, as well as model the intricacies of vehicle fuel consumption and emissions that result from these vehicle dynamics. Consequently, the assessment of the energy and emission impacts of alternative investments can

Rakha, Hesham A.

302

Odor and VOC Emissions from Pan Frying of Mackerel at Three Stages: Raw, Well-Done, and Charred  

PubMed Central

Many classes of odorants and volatile organic compounds that are deleterious to our wellbeing can be emitted from diverse cooking activities. Once emitted, they can persist in our living space for varying durations. In this study, various volatile organic compounds released prior to and during the pan frying of fish (mackerel) were analyzed at three different cooking stages (stage 1 = raw (R), stage 2 = well-done (W), and stage 3 = overcooked/charred (O)). Generally, most volatile organic compounds recorded their highest concentration levels at stage 3 (O), e.g., 465 (trimethylamine) and 106 ppb (acetic acid). In contrast, at stage 2 (W), the lowest volatile organic compounds emissions were observed. The overall results of this study confirm that trimethylamine is identified as the strongest odorous compound, especially prior to cooking (stage 1 (R)) and during overcooking leading to charring (stage 3 (O)). As there is a paucity of research effort to measure odor intensities from pan frying of mackerel, this study will provide valuable information regarding the management of indoor air quality. PMID:25405596

Ahn, Jeong-Hyeon; Szulejko, Jan E.; Kim, Ki-Hyun; Kim, Yong-Hyun; Kim, Bo-Won

2014-01-01

303

Measuring Spatial Variability of Vapor Flux to Characterize Vadose-zone VOC Sources: Flow-cell Experiments  

SciTech Connect

A method termed vapor-phase tomography has recently been proposed to characterize the distribution of volatile organic contaminant mass in vadose-zone source areas, and to measure associated three-dimensional distributions of local contaminant mass discharge. The method is based on measuring the spatial variability of vapor flux, and thus inherent to its effectiveness is the premise that the magnitudes and temporal variability of vapor concentrations measured at different monitoring points within the interrogated area will be a function of the geospatial positions of the points relative to the source location. A series of flow-cell experiments was conducted to evaluate this premise. A well-defined source zone was created by injection and extraction of a non-reactive gas (SF6). Spatial and temporal concentration distributions obtained from the tests were compared to simulations produced with a mathematical model describing advective and diffusive transport. Tests were conducted to characterize both areal and vertical components of the application. Decreases in concentration over time were observed for monitoring points located on the opposite side of the source zone from the local–extraction point, whereas increases were observed for monitoring points located between the local–extraction point and the source zone. The results illustrate that comparison of temporal concentration profiles obtained at various monitoring points gives a general indication of the source location with respect to the extraction and monitoring points.

Mainhagu, Jon; Morrison, C.; Truex, Michael J.; Oostrom, Martinus; Brusseau, Mark

2014-10-20

304

Measuring spatial variability of vapor flux to characterize vadose-zone VOC sources: flow-cell experiments.  

PubMed

A method termed vapor-phase tomography has recently been proposed to characterize the distribution of volatile organic contaminant mass in vadose-zone source areas, and to measure associated three-dimensional distributions of local contaminant mass discharge. The method is based on measuring the spatial variability of vapor flux, and thus inherent to its effectiveness is the premise that the magnitudes and temporal variability of vapor concentrations measured at different monitoring points within the interrogated area will be a function of the geospatial positions of the points relative to the source location. A series of flow-cell experiments was conducted to evaluate this premise. A well-defined source zone was created by injection and extraction of a non-reactive gas (SF6). Spatial and temporal concentration distributions obtained from the tests were compared to simulations produced with a mathematical model describing advective and diffusive transport. Tests were conducted to characterize both areal and vertical components of the application. Decreases in concentration over time were observed for monitoring points located on the opposite side of the source zone from the local-extraction point, whereas increases were observed for monitoring points located between the local-extraction point and the source zone. The results illustrate that comparison of temporal concentration profiles obtained at various monitoring points gives a general indication of the source location with respect to the extraction and monitoring points. PMID:25171394

Mainhagu, J; Morrison, C; Truex, M; Oostrom, M; Brusseau, M L

2014-10-15

305

Measuring spatial variability of vapor flux to characterize vadose-zone VOC sources: Flow-cell experiments  

NASA Astrophysics Data System (ADS)

A method termed vapor-phase tomography has recently been proposed to characterize the distribution of volatile organic contaminant mass in vadose-zone source areas, and to measure associated three-dimensional distributions of local contaminant mass discharge. The method is based on measuring the spatial variability of vapor flux, and thus inherent to its effectiveness is the premise that the magnitudes and temporal variability of vapor concentrations measured at different monitoring points within the interrogated area will be a function of the geospatial positions of the points relative to the source location. A series of flow-cell experiments was conducted to evaluate this premise. A well-defined source zone was created by injection and extraction of a non-reactive gas (SF6). Spatial and temporal concentration distributions obtained from the tests were compared to simulations produced with a mathematical model describing advective and diffusive transport. Tests were conducted to characterize both areal and vertical components of the application. Decreases in concentration over time were observed for monitoring points located on the opposite side of the source zone from the local-extraction point, whereas increases were observed for monitoring points located between the local-extraction point and the source zone. The results illustrate that comparison of temporal concentration profiles obtained at various monitoring points gives a general indication of the source location with respect to the extraction and monitoring points.

Mainhagu, J.; Morrison, C.; Truex, M.; Oostrom, M.; Brusseau, M. L.

2014-10-01

306

IDENTIFICATION AND CHARACTERIZATION OF MISSING AND UNACCOUNTED FOR AREA SOURCE CATEGORIES  

EPA Science Inventory

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 (CO) are estimated annuall...

307

Unspeciated Organic Emissions From Combustion Sources And Their Influence On The Secondary Organic Aerosol Budget In The United States  

NASA Astrophysics Data System (ADS)

Combustion sources are a major source of organic emissions and therefore a potentially important source for secondary organic aerosol (SOA) formation in the atmosphere. Although speciated organic emissions from combustion sources are considered in models to form SOA, a large fraction of the organics are unspeciated. In this work, we analyze data from numerous smog chamber experiments, which photo-oxidized dilute emissions from different combustion sources (on-road gasoline vehicles, aircraft, on-road diesel vehicles, wood burning and open biomass burning), to determine the contribution that unspeciated emissions make to SOA formation. An SOA model based on speciated organics is able to explain, on average, 8-31% of the SOA measured in the experiments. We hypothesize that the remainder results from the gas-phase oxidation of unspeciated emissions, which account on average for 25-75% of the non-methane organic gas (NMOG) emissions. Using the SOA data, we develop, for the first time, source-specific parameterizations to model SOA from unspeciated emissions; all sources seem to have median SOA yields similar to large n-alkanes (C12+). To assess the influence of unspeciated emissions on SOA formation regionally, we use the parameterization to predict SOA production in the United States. Using emissions data collected during the smog chamber experiments and data available in literature, we build a gross inventory for unspeciated emissions in the United States. We discover that unspeciated organics might be included in the current generation of SOA models but misallocated in terms of its SOA potential. The top six combustion sources (on- and off-road gasoline, on- and off-road diesel, open biomass and wood burning) emit 2.61 Tg yr-1 of unspeciated emissions (20% of US anthropogenic VOC emissions from combustion sources) and are estimated to form a minimum of 0.68 Tg yr-1 of SOA; the estimate is a third of the biogenic SOA produced in the US. We predict that accounting for SOA from unspeciated emissions will double modeled SOA formation from anthropogenic combustion sources. Primary organic aerosol (POA) emission factors and secondary organic aerosol (SOA) box-plots for five source categories. The colored bars on the right show the median range for the entire data.

Jathar, S.; Gordon, T.; Hennigan, C. J.; Pye, H. O.; Donahue, N. M.; Adams, P. J.; Robinson, A. L.

2012-12-01

308

Trends of VOC exposures among a nationally representative sample: Analysis of the NHANES 1988 through 2004 data sets  

NASA Astrophysics Data System (ADS)

Exposures to volatile organic compounds (VOCs) are ubiquitous due to emissions from personal, commercial and industrial products, but quantitative and representative information regarding long term exposure trends is lacking. This study characterizes trends from 1988 to 2004 for the 15 VOCs measured in blood in five cohorts of the National Health and Nutrition Examination Survey (NHANES), a large and representative sample of U.S. adults. Trends were evaluated at various percentiles using linear quantile regression (QR) models, which were adjusted for solvent-related occupations and cotinine levels. Most VOCs showed decreasing trends at all quantiles, e.g., median exposures declined by 2.5 (m,p-xylene) to 6.4 (tetrachloroethene) percent per year over the 15 year period. Trends varied by VOC and quantile, and were grouped into three patterns: similar decreases at all quantiles (including benzene, toluene); most rapid decreases at upper quantiles (ethylbenzene, m,p-xylene, o-xylene, styrene, chloroform, tetrachloroethene); and fastest declines at central quantiles (1,4-dichlorobenzene). These patterns reflect changes in exposure sources, e.g., upper-percentile exposures may result mostly from occupational exposure, while lower percentile exposures arise from general environmental sources. Both VOC emissions aggregated at the national level and VOC concentrations measured in ambient air also have declined substantially over the study period and are supportive of the exposure trends, although the NHANES data suggest the importance of indoor sources and personal activities on VOC exposures. While piecewise QR models suggest that exposures of several VOCs decreased little or any during the 1990's, followed by more rapid decreases from 1999 to 2004, questions are raised concerning the reliability of VOC data in several of the NHANES cohorts and its applicability as an exposure indicator, as demonstrated by the modest correlation between VOC levels in blood and personal air collected in the 1999/2000 cohort. Despite some limitations, the NHANES data provides a unique, long term and direct measurement of VOC exposures and trends.

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

2011-09-01

309

Trends of VOC exposures among a nationally representative sample: Analysis of the NHANES 1988 through 2004 data sets  

PubMed Central

Exposures to volatile organic compounds (VOCs) are ubiquitous due to emissions from personal, commercial and industrial products, but quantitative and representative information regarding long term exposure trends is lacking. This study characterizes trends from1988 to 2004 for the 15 VOCs measured in blood in five cohorts of the National Health and Nutrition Examination Survey (NHANES), a large and representative sample of U.S. adults. Trends were evaluated at various percentiles using linear quantile regression (QR) models, which were adjusted for solvent-related occupations and cotinine levels. Most VOCs showed decreasing trends at all quantiles, e.g., median exposures declined by 2.5 (m, p-xylene) to 6.4 (tetrachloroethene) percent per year over the 15 year period. Trends varied by VOC and quantile, and were grouped into three patterns: similar decreases at all quantiles (including benzene, toluene); most rapid decreases at upper quantiles (ethylbenzene, m, p-xylene, o-xylene, styrene, chloroform, tetrachloroethene); and fastest declines at central quantiles (1,4-dichlorobenzene). These patterns reflect changes in exposure sources, e.g., upper-percentile exposures may result mostly from occupational exposure, while lower percentile exposures arise from general environmental sources. Both VOC emissions aggregated at the national level and VOC concentrations measured in ambient air also have declined substantially over the study period and are supportive of the exposure trends, although the NHANES data suggest the importance of indoor sources and personal activities on VOC exposures. While piecewise QR models suggest that exposures of several VOCs decreased little or any during the 1990’s, followed by more rapid decreases from 1999 to 2004, questions are raised concerning the reliability of VOC data in several of the NHANES cohorts and its applicability as an exposure indicator, as demonstrated by the modest correlation between VOC levels in blood and personal air collected in the 1999/2000 cohort. Despite some limitations, the NHANES data provides a unique, long term and direct measurement of VOC exposures and trends. PMID:25705111

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

2015-01-01

310

Emission inventory of non-methane volatile organic compounds from anthropogenic sources in India  

NASA Astrophysics Data System (ADS)

This paper presents a new inventory of NMVOC emissions from anthropogenic sources in India for the year 2010. The main new element of this inventory, compared to previous work for India, is the use of new and more detailed data on solvent use sectors and oil production and distribution system. The results are presented at the national and state level for major sectors and VOC species. Finally, the annual emissions were spatially distributed at a fine resolution of 36 × 36 km2 using detailed spatial information. The total anthropogenic NMVOC emissions in India in 2010 were estimated at 9.81 Tg which is in the range of the estimates made in most other studies. The majority of emissions (60%) originated from residential combustion of biomass for cooking. Solvent use sectors and oil production and distribution contributed about 20% followed by transport (12%) and open burning of agricultural residues (7%). Specie-wise distribution shows highest contribution from alkenes and alkynes (38%), followed by alkanes (22%), and aromatics (16%).

Sharma, Sumit; Goel, Anju; Gupta, Divya; Kumar, Atul; Mishra, Arabinda; Kundu, Seema; Chatani, Satoru; Klimont, Zbigniew

2015-02-01

311

IMPACTS OF CLIMATE CHANGE AND LAND COVER CHANGE ON BIOGENIC VOLATILE ORGANIC COMPOUNDS (BVOCS) EMISSIONS IN TEXAS  

EPA Science Inventory

Significant amounts of vegetation and forests in eastern and central Texas are the source of substantial emissions of volatile organic compounds (VOCs) which, when mixed with nitrogen oxides from anthropogenic sources, can lead to ozone formation. The biogenic emis...

312

Constraining Emission Models of Luminous Blazar Sources  

NASA Astrophysics Data System (ADS)

Many luminous blazars which are associated with quasar-type active galactic nuclei display broadband spectra characterized by a large luminosity ratio of their high-energy (?-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 also typically have 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 the production of ?-rays via upscattering 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 ?-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 intraday flares occasionally observed in powerful blazar sources.

Sikora, Marek; Stawarz, ?ukasz; Moderski, Rafa?; Nalewajko, Krzysztof; Madejski, Greg M.

2009-10-01

313

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

314

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

315

Emissivity Tuned Emitter for RTPV Power Sources  

SciTech Connect

Every mission launched by NASA to the outer planets has produced unexpected results. The Voyager I and II, Galileo, and Cassini missions produced images and collected scientific data that totally revolutionized our understanding of the solar system and the formation of the planetary systems. These missions were enabled by the use of nuclear power. Because of the distances from the Sun, electrical power was produced using the radioactive decay of a plutonium isotope. Radioisotopic Thermoelectric Generators (RTGs) used in the past and currently used Multi-Mission RTGs (MMRTGs) provide power for space missions. Unfortunately, RTGs rely on thermocouples to convert heat to electricity and are inherently inefficient ({approx} 3-7% thermal to electric efficiency). A Radioisotope Thermal Photovoltaic (RTPV) power source has the potential to reduce the specific mass of the onboard power supply by increasing the efficiency of thermal to electric conversion. In an RTPV, a radioisotope heats an emitter, which emits light to a photovoltaic (PV) cell, which converts the light into electricity. Developing an emitter tuned to the desired wavelength of the photovoltaic is a key part in increasing overall performance. Researchers at the NASA Glenn Research Center (GRC) have built a Thermal Photovoltaic (TPV) system, that utilizes a simulated General Purpose Heat Source (GPHS) from a MMRTG to heat a tantalum emitter. The GPHS is a block of graphite roughly 10 cm by 10 cm by 5 cm. A fully loaded GPHS produces 250 w of thermal power and weighs 1.6 kgs. The GRC system relies on the GPHS unit radiating at 1200 K to a tantalum emitter that, in turn, radiates light to a GaInAs photo-voltaic cell. The GRC claims system efficiency of conversion of 15%. The specific mass is around 167 kg/kWe. A RTPV power source that utilized a ceramic or ceramic-metal (cermet) matrix would allow for the combination of the heat source, canister, and emitter into one compact unit, and allow variation in size and shape to optimize temperature and emission spectra.

Carl M. Stoots; Robert C. O'Brien; Troy M. Howe

2012-03-01

316

NONFERROUS INDUSTRY PARTICULATE EMISSIONS: SOURCE CATEGORY REPORT  

EPA Science Inventory

The report gives results of the development of particulate emission factors based on cutoff size for inhalable particles for the nonferrous industry. After a review of available information characterizing particulate emissions from nonferrous plants, the data were summarized and ...

317

RESEARCH ON EMISSIONS AND MITIGATION OF POP'S FROM COMBUSTION SOURCES  

EPA Science Inventory

Chapter summarizes EPA's research on emissions and control of persistent organic pollutants (POPS) from combustion sources, with emphasis on source characterization and measurement, formation and destruction mechanisms, formation prevention, and flue gas cleaning. Laboratory exp...

318

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 ...

319

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

EPA Science Inventory

The objective of this program is to characterize mobile source emissions which are one of the largest sources of tropospheric ozone precursor emissions (CO, NOx, and volotile organic compounds) in the U.S. The research objective of the Emissions Characterization and Prevention Br...

320

EMISSIONS FORECASTS FOR INDUSTRIAL PROCESS SOURCES  

EPA Science Inventory

The report gives national and regional air emissions forecasts from several sulfur oxide and nitrogen oxide (SOx and NOx) emissions control Process Model Projection Technique (PROMPT) test runs. PROMPT, one of a number of National Acid Precipitation Assessment Program emission fo...

321

Carbonyl emissions from vehicular exhausts sources in Hong Kong  

Microsoft Academic Search

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

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

2012-01-01

322

Carbonyl Emissions from Vehicular Exhausts Sources in Hong Kong  

Microsoft Academic Search

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)

Steven Sai Hang Ho; Kin Fai Ho; Shun Cheng Lee; Yan Cheng; Jian Zhen Yu; Ka Man Lam; Carrie Feng; Yu Huang

2011-01-01

323

Source localization of Jupiter's Io dependent radio emissions  

NASA Technical Reports Server (NTRS)

The peak frequencies of the Io-dependent part of the Jovian emissions are compared with the surface gyrofrequency determined from Jovian magnetic models in order to localize the source of Jovian radio emissions. The bulk of the Io-controlled emissions was found to be delayed by up to 70 deg of equatorial longitude from the predicted instantaneous position of the Io flux tube, with the L and S emissions both displaying this same unexpected behavior. It is suggested that the source of these emissions is delayed substantially with respect to Io either as an Alfven-wave delay or because of errors in the magnetic field models.

Aubier, Monique G.; Genova, Francoise; Calvert, Wynne

1988-01-01

324

N-bursty emission from Uranus: A cyclotron maser source?  

NASA Technical Reports Server (NTRS)

Ray tracing studies of RX-mode emission from the north polar regions of Uranus indicate that the n-bursty radio emission may have a source along field lines with footprints near the northern magnetic pole (perhaps in the cusp), but not necessarily associated with regions of strong UV emission. This is in contrast with similar studies for the Uranus nightside smooth radio emission, which are believed to be due to the cyclotron maser instability. Source regions can be found for both hollow and filled emission cones and for frequencies well above the local gyrofreuquency implying that mechanisms other than the cyclotron maser mechanism may be operating.

Curran, D. B.; Menietti, J. D.

1993-01-01

325

Thermal and Catalytic Incinerators for the Control of VOCs  

Microsoft Academic Search

The emission of Volatile Organic Compounds (VOCs) is attracting increasing concern both from the public and by government agencies. Among the many available control technologies for the treatment of VOC containing waste streams, incineration offers an ultimate disposal strategy rather than a means for collecting or concentrating the offending compounds. This paper describes the major, commercially available thermal and catalytic

D. R. van der Vaart; W. M. Vatvuk; A. H. Wehe

1991-01-01

326

Locating and estimating air emissions from sources of epichlorohydrin  

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 epichlorohydrin. Its intended audience includes Federal, State and local air pollution personnel and others interested in locating potential emitters of epichlorohydrin in making gross estimates of air emissions therefrom. This document presents information on 1) the types of sources that may emit epichlorohydrin; 2) process variations and release points that may be expected within these sources; and 3) available emissions information indicating the potential for epichlorohydrin release into the air from each operation.

Not Available

1985-09-01

327

REVIEW OF INDOOR EMISSION SOURCE MODELS--PART 1. OVERVIEW  

EPA Science Inventory

Indoor emission source models are mainly used as a component in indoor air quality (IAQ) and exposure modeling. They are also widely used to interpret the experimental data obtained from environmental chambers and buildings. This paper compiles 46 indoor emission source models fo...

328

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...

329

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 ...

330

Improvement of health risk factors after reduction of VOC concentrations in industrial and urban areas.  

PubMed

After reductions of fugitive and diffuse emissions by an industrial complex, a follow-up study was performed to determine the time variability of volatile organic compounds (VOCs) and the lifetime cancer risk (LCR). Passive samplers (3 M monitors) were placed outdoors (n?=?179) and indoors (n?=?75) in industrial, urban, and control areas for 4 weeks. Twenty-five compounds including n-alkanes, cycloalkanes, aromatics, chlorinated hydrocarbons, and terpenes were determined by GC/MS. The results show a significant decrease of all VOCs, especially in the industrial area and to a lesser extent in the urban area. The median outdoor concentration of benzene in the industrial area declined compared to the former study, around 85% and about 50% in the urban area, which in the past was strongly influenced by industrial emissions. Other carcinogenic compounds like styrene and tetrachloroethylene were reduced to approximately 60%. VOC concentrations in control areas remained nearly unchanged. According to the determined BTEX ratios and interspecies correlations, in contrast to the previous study, traffic was identified as the main emission source in the urban and control areas and showed an increased influence in the industrial area. The LCR, calculated for benzene, styrene, and tetrachloroethylene, shows a decrease of one order of magnitude in accordance to the decreased total VOC concentrations and is now acceptable according to values proposed by the World Health Organization. PMID:24788932

Lerner, Jorge Esteban Colman; Kohajda, Tibor; Aguilar, Myriam Elisabeth; Massolo, Laura Andrea; Sánchez, Erica Yanina; Porta, Atilio Andrés; Opitz, Philipp; Wichmann, Gunnar; Herbarth, Olf; Mueller, Andrea

2014-08-01

331

Destruction of air emissions using catalytic oxidation  

Microsoft Academic Search

This paper discusses key emission stream characteristics and hazardous air pollutant (HAP) characteristics that affect the applicability of catalytic oxidation as an air pollution control technique in which volatile organic compounds (VOCs) and vapor-phase air toxics in an air emission stream are oxidized with the help of a catalyst. Design of catalytic systems for control of point-source emissions is based

M. Kosusko; G. M. Ramsey

1988-01-01

332

Source sampling of particulate matter emissions from cotton harvesting - System field testing and emission factor development  

Technology Transfer Automated Retrieval System (TEKTRAN)

Emission factors are used in the air pollution regulatory process to quantify the mass of pollutants emitted from a source. Accurate emission factors must be used in the air pollution regulatory process to ensure fair and appropriate regulation for all sources. Agricultural sources, including cotton...

333

Application of OMI Observations to a Space-Based Indicator of NOx and VOC Controls on Surface Ozone Formation  

NASA Technical Reports Server (NTRS)

We investigated variations in the relative sensitivity of surface ozone formation in summer to precursor species concentrations of volatile organic compounds (VOCs) and nitrogen oxides (NOx) as inferred from the ratio of the tropospheric columns of formaldehyde to nitrogen dioxide (the "Ratio") from the Aura Ozone Monitoring Instrument (OMI). Our modeling study suggests that ozone formation decreases with reductions in VOCs at Ratios less than 1 and NOx at Ratios greater than 2; both NOx and VOC reductions may decrease ozone formation for Ratios between 1 and 2. Using this criteria. the OMI data indicate that ozone formation became: 1. more sensitive to NOx over most of the United States from 2005 to 2007 because of the substantial decrease in NOx emissions, primarily from stationary sources, and the concomitant decrease in the tropospheric column of NO2. and 2. more sensitive to NOx with increasing temperature, in part because emissions of highly reactive, biogenic isoprene increase with temperature, thus increasing the total VOC reactivity. In cities with relatively low isoprene emissions (e.g .. Chicago). the data clearly indicate that ozone formation became more sensitive to NOx from 2005 to 2007. In cities with relatively high isoprene emissions (e.g ., Atlanta), we found that the increase in the Ratio due to decreasing NOx emissions was not obvious as this signal was convolved with variations in the Ratio associated with the temperature dependence of isoprene emissions and, consequently, the formaldehyde concentration.

Duncan, Bryan N.; Yoshida, Yasuko; Olson, Jennifer R.; Sillman, Sanford; Martin, Randall V.; Lamsal, Lok; Hu, Yongtao; Pickering, Kenneth E.; Retscher, Christian; Allen, Dale J.; Crawford, James H.

2010-01-01

334

Release of VOCs and particles during use of nanofilm spray products.  

PubMed

Here, we present emission data on VOCs and particles emitted during simulated use of four commercial nanofilm spray products (NFPs) used for making easy-to-clean or self-cleaning surfaces on floors, ceramic tiles, and windows. The aim was to characterize the emitted VOCs and to provide specific source strength data for VOCs and particles released to the airduring use of the products. Containers with NFP were mounted on a spray-stand inside a closed stainless steel chamber with no air exchange. NFPs were sprayed in amounts corresponding to 1 m2 surface toward a target plate at a distance of 35 cm. Released VOCs were measured by a combination of air sampling on Tenax TA adsorbent followed by thermal desorption GC/MS and GC/FID analysis and real time measurements using a miniature membrane inlet mass spectrometer. Particles were measured using a fast mobility particle sizer and an aerosol particle sizer. A number of VOCs were identified, including small alcohols, ketones and ethers, chlorinated acetones, a perfluorinated silane, limonene, and cyclic siloxanes. The number of generated particles was on the order of 3 x 10(8) to 2 x 10(10) particles/m3 per g sprayed NFP and were dominated by nanosize particles. PMID:19921900

Nørgaard, Asger W; Jensen, Keld A; Janfelt, Christian; Lauritsen, Frants R; Clausen, Per A; Wolkoff, Peder

2009-10-15

335

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

Microsoft Academic Search

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

Wan-Kuen Jo; Ki-Berm Song

2001-01-01

336

A temporally and spatially resolved validation of emission inventories by measurements of ambient volatile organic compounds in Beijing, China  

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

337

CONTROL OF INDUSTRIAL VOC (VOLATILE ORGANIC COMPOUND) EMISSIONS BY CATALYTIC INCINERATION. VOLUME 6. CATALYTIC INCINERATOR PERFORMANCE AT INDUSTRIAL SITE C-4  

EPA Science Inventory

Radian Corporation is conducting a testing program for the EPA to document the performance of catalytic incinerators applied to industrial processes for volatile organic compound (VOC) control. Performance data collected at each test site is being summarized in a series of test r...

338

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 ...

339

CONTROL OF INDUSTRIAL VOC (VOLATILE ORGANIC COMPOUND) EMISSIONS BY CATALYTIC INCINERATION. VOLUME 2. FINAL REPORT ON CATALYTIC INCINERATOR PERFORMANCE AT SIX INDUSTRIAL SITES  

EPA Science Inventory

The task of meeting these objectives was accomplished in two phases. In the first phase, information was assembled from the literature on the use and cost of using catalytic incineration for VOC control. This phase of the study provides results in the following areas: A review of...

340

Design of novel Pt-structured catalyst on anodic aluminum support for VOC’s catalytic combustion  

Microsoft Academic Search

Emission control of volatile organic compounds (VOCs) is one of the priorities for environmental catalysis. Catalytic combustion is one of promising technologies for elimination of VOCs. A novel platinum-structured catalyst was designed and is presented in this work. Aluminum was used as support for the catalyst after anodic oxidation treatment and in a shifted arrangement bent, short channels are applied

Lifeng Wang; Thanh Phong Tran; Dong Vien Vo; Makoto Sakurai; Hideo Kameyama

2008-01-01

341

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

342

Emissions of volatile organic compounds during the decomposition of plant litter  

E-print Network

Emissions of volatile organic compounds during the decomposition of plant litter Christopher M plant litter decomposition, and such VOCs can have wideranging impacts on atmospheric chemistry of the relative importance of biotic versus abiotic sources of these VOCs and whether distinct types of litter

Fierer, Noah

343

FUGITIVE EMISSION SOURCES AND BATCH OPERATIONS IN SYNTHETIC ORGANIC CHEMICAL PRODUCTION  

EPA Science Inventory

This survey report was developed for the EPA for use in assessing the potential magnitude of fugitive volatile organic compound (VOC) emissions from agitator seals, cooling towers and batch operations in the production of 378 designated chemicals. The information presented in thi...

344

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

PubMed

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

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

2004-01-01

345

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

PubMed Central

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 bio-diesel 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 C9 to C16 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.

2015-01-01

346

A LOW COST CATALYTIC FILTER FOR SIMULTANEOUS VOC AND PARTICULATE REMOVAL - PHASE II  

EPA Science Inventory

Emissions of VOC's are subject to control by the EPA both because VOC's are regarded as ozone precursors and because many specific VOC's are hazardous air pollutants (HAP's) under the Clean Air Act Amendments. A number of industries generate offgases with both fine particul...

347

Use of biofilters and suspended-growth reactors to treat VOCs  

Microsoft Academic Search

The greater limits placed on volatile organic compound (VOC) emissions by the Clean Air Act Amendments have stimulated evaluation of various VOC treatment methods. Two applicable gas phase treatment technologies are biofiltration and suspended growth reactors. Biofiltration removes contaminants from gas streams that are passed through a bed of biologically active solids. An aerobic suspended-growth reactor (SGR) removes VOCs by

Aaron B Neal; Raymond C Loehr

2000-01-01

348

Receptor modeling of ambient VOC at Santiago, Chile  

NASA Astrophysics Data System (ADS)

Ambient VOC measured at a 1996 spring campaign at Santiago, Chile, have been analyzed using the receptor models UNMIX and Positive Matrix Factorization (PMF). The ambient campaign took place at two sites: a downtown site, close to major traffic emissions, and a residential site, downwind of major industrial sources and highways. At the downtown site the following source apportionments estimates were obtained: fuel evaporation, 29.7±5.6%; gasoline exhaust, 22.0±3.4%; diesel exhaust, 18.1±2.9%; biogenic, LPG and evaporative emissions, 18.0±3.4%, unexplained: 12%. At the residential site, the following source apportionment was obtained: transported gasoline exhaust, 31.2±4.1%; local gasoline exhaust, 25.5±4.0%; evaporative losses, 11.7±2.8%; LPG losses, 11.0±2.5%; biogenic emissions, 7.7±1.7%; diesel exhaust, 6.2±1.5%; unexplained, 7.7%. Thus, near 70% of ambient VOC impacts at both sites are due to mobile sources. The receptor analyses produced source profiles that had distinctive, dominant compounds; in addition, source contributions exhibited diurnal profiles that were consistent with ambient temperature and wind speed data, and the expected activity patterns within the city. Typical errors in the source contributions vary between 15% for the larger sources—like gasoline exhaust—and 25% for the smaller sources—like biogenic emissions. It was found that the number of factors given by the UNMIX model was a good starting point to refine the solution using PMF. Both models showed good performance at discriminating between source profiles that had similar compositions in subsets of common species, but PMF was able to find better, cleaner source profiles that did UNMIX. At both monitoring sites LPG losses appear mixed in with other source profiles, and this feature could not be solved by adding more source profiles in the analyses; this was likely due to a lack of C 3 measurements needed to better resolve an LPG source profile.

Jorquera, Héctor; Rappenglück, Bernhard

349

[Pollution characteristics and health risk assessment of atmospheric VOCs in the downtown area of Guangzhou, China].  

PubMed

The measurements of 31 kinds of VOCs in the ambient air of a site were carried out in the downtown of Guangzhou by online method from November 5, 2009 to November 9, 2009. The ambient level and composition characteristics, temporal variation characteristics, sources identification, and chemical reactivity of VOCs were studied, and the health risk of VOCs in the ambient air in the study area was assessed by using the international recognized health risk assessment method. Results showed that the mean and the range of the mass concentrations of 31 VOCs were 114.51 microg x m(-3) and 29.42-546.06 microg x m(-3), respectively. The mass concentrations of 31 VOCs, and those of alkanes, alkenes, and aromatics all showed a changing trend of higher in the morning and in the evening, and lower at noontime. Vehicular exhaust, gasoline and liquefied petroleum gas evaporates were the main sources of VOCs with the volatilization of paints and solvents being important emission sources. Toluene, trans-2-butene, m/p-xylene, i-butane, and 1,3,5-trimethylbenzene were the key reactive species among the 31 VOCs. Vehicular exhaust and gasoline evaporation were the main sources of VOCs leading to the formation of ozone. Health risk assessment showed that n-hexane, 1,3-butadiene, benzene, toluene, ethylbenzene, m/p-xylene and o-xylene had no appreciable risk of adverse non-cancer health effect on the exposed population, but 1, 3-butadiene and benzene had potential cancer risk. By comparing the corresponding data about health risk assessment of benzene compounds in some cities in China, it is concluded that benzene can impose relatively high cancer risk to the exposed populations in the ambient air of some cities in China. Therefore, strict countermeasures should be taken to further control the pollution of benzene in the ambient air of cities, and it is imperative to start the related studies and develop the atmospheric environmental health criteria and national ambient air quality standard for benzene in China. PMID:24640890

Li, Lei; Li, Hong; Wang, Xue-Zhong; Zhang, Xin-Min; Wen, Chong

2013-12-01

350

Quasi-monochromatic field-emission x-ray source  

SciTech Connect

By favoring the L-peak emission over the bremsstrahlung part, direct quasi-monochromatic soft x-ray emission has been obtained with a field emission (FE) x-ray source. The electron impact x-ray setup uses an arrayed cathode of carbon nanopearl FE tips as a stable cold electron source within a vacuum of 10{sup -6}-10{sup -7} Torr. The high brightness of the FE e-beam coupled with the array structure of the cold cathode allows a smoother control of the x-ray emission intensity. The wavelength of the x-ray source can be modified by the choice of target materials. Using Mo as the target material, the x-ray emission shows a peak centered at 2.45 keV with a monochromaticity between 75% and 55% and a FWHM in the range of 450 eV.

Diop, Babacar; Binh, Vu Thien [LPMCN, University of Lyon 1, Villeurbanne 69622 (France)

2012-09-15

351

Detecting Isobaric VOCs  

SciTech Connect

Volatile organic compounds (VOCs) can be monitored by proton transfer reaction (PTR) MS, in which a PTR drift tube is coupled to a quadrupole mass spectrometer. In this technique, compounds undergo proton transfer reactions when they collide with H?O? ions. This soft chemical ionization method, which results in little fragmentation, allows researchers to detect trace levels of VOCs from relatively uncomplicated spectra. Sometimes, the m/z values of VOCs are similar or identical, rendering it impossible to make a positive identification. Thus, Michael Alexander and co-workers at the Pacific Northwest National Laboratory, San Francisco State University, and Innsbruck University (Austria) developed a novel instrument that couples a PTR drift tube to an ion trap mass spectrometer, which can perform MS/MS, to produce characteristic fragments of isobaric species.

Prazeller, Peter; Palmer, Peter T.; Boscaini, Elena; Jobson, B Tom; Alexander, M. Lizabeth

2003-09-01

352

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...

353

DEVELOPMENT OF A MONITOR FOR HCN IN MOBILE SOURCE EMISSIONS  

EPA Science Inventory

Three real-time monitors for measurement of HCN concentrations in mobile source emissions have been designed, built, tested, and delivered to the Environmental Protection Agency (EPA). The important design parameters for these identical instruments were determined during the firs...

354

Air Quality: Air Pollutants, SLAC Emissions Sources, and Regulatory Reference  

E-print Network

Air Quality: Air Pollutants, SLAC Emissions Sources, and Regulatory Reference Department: Chemical permit regulations are designed to track, record, and control air pollutants belonging to several on chemical classifications. This reference outlines major categories of air pollutants found at SLAC

Wechsler, Risa H.

355

Snowmobile Contributions to Mobile Source Emissions in Yellowstone  

E-print Network

kilogram of fuel consumed. In addition, using an ultraviolet monochromator, 460 measurements of toluene estimate for the summer mobile source emissions. Use of oxygenated fuels in snowmobiles was found to reduce

Denver, University of

356

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 ...

357

IMPACT OF A PRIMARY SULFATE EMISSION SOURCE ON AIR QUALITY  

EPA Science Inventory

A one-month study was carried out at an isolated oil-fired power plant in New York State to assess the impact of primary sulfate emissions on air quality. Emissions of total sulfate from the source varied from 22 kg/hr to 82 kg/hr per boiler with the sulfuric acid concentration a...

358

CHARACTERIZATION OF EMISSIONS FROM COMBUSTION SOURCES: CONTROLLED STUDIES  

EPA Science Inventory

The paper summarizes Session I papers (given at the EPA Workshop on Characterization of Contaminant Emissions from Indoor Sources, Chapel Hill, NC, May 1985) that illustrate the progress made to date on characterizing indoor combustion emissions from unvented space heaters, gas a...

359

METHODS FOR ATTRIBUTING AMBIENT AIR POLLUTANTS TO EMISSION SOURCES  

Microsoft Academic Search

Abstract Six methods for attributing ambient pollutants to emission sources are reviewed: emissions analysis, trend analysis, tracer studies, trajectory analysis, receptor modeling, and dispersion modeling. The ranges of applicability, types of information provided, limitations, performance capabilities, and areas of active research of the different methods are compared. For primary, nonreactive pollutants whose effects of concern occur on a global scale,

Charles L. Blanchard

1999-01-01

360

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...

361

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...

362

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

363

Observation and modelling of OH and HO2 concentrations in the Pearl River Delta 2006: a missing OH source in a VOC rich atmosphere  

NASA Astrophysics Data System (ADS)

Ambient OH and HO2 concentrations were measured by laser induced fluorescence (LIF) during the PRIDE-PRD2006 (Program of Regional Integrated Experiments of Air Quality over the Pearl River Delta, 2006) campaign at a rural site downwind of the megacity of Guangzhou in Southern China. The observed OH concentrations reached daily peak values of (15-26) × 106 cm-3 which are among the highest values so far reported for urban and suburban areas. The observed OH shows a consistent high correlation with j(O1D) over a broad range of NOx conditions. The correlation cannot be reproduced by model simulations, indicating that OH stabilizing processes are missing in current models. The observed OH exhibited a weak dependence on NOx in contrast to model predictions. While modelled and measured OH agree well at NO mixing ratios above 1 ppb, a continuously increasing underprediction of the observed OH is found towards lower NO concentrations, reaching a factor of 8 at 0.02 ppb NO. A dependence of the modelled-to-measured OH ratio on isoprene cannot be concluded from the PRD data. However, the magnitude of the ratio fits into the isoprene dependent trend that was reported from other campaigns in forested regions. Hofzumahaus et al. (2009) proposed an unknown OH recycling process without NO, in order to explain the high OH levels at PRD in the presence of high VOC reactivity and low NO. Taking a recently discovered interference in the LIF measurement of HO2 into account, the need for an additional HO2 ? OH recycling process persists, but the required source strength may be up to 20% larger than previously determined. Recently postulated isoprene mechanisms by Lelieveld et al. (2008) and Peeters and Müller (2010) lead to significant enhancements of OH expected for PRD, but an underprediction of the observed OH by a factor of two remains at low NO (0.1-0.2 ppb). If the photolysis of hydroperoxy aldehydes from isoprene is as efficient as proposed by Peeters and Müller (2010), the corresponding OH formation at PRD would be more important than the primary OH production from ozone and HONO. While the new isoprene mechanisms need to be confirmed by laboratory experiments, there is probably need for other, so far unidentified chemical processes to explain entirely the high OH levels observed in Southern China.

Lu, K. D.; Rohrer, F.; Holland, F.; Fuchs, H.; Bohn, B.; Brauers, T.; Chang, C. C.; Häseler, R.; Hu, M.; Kita, K.; Kondo, Y.; Li, X.; Lou, S. R.; Nehr, S.; Shao, M.; Zeng, L. M.; Wahner, A.; Zhang, Y. H.; Hofzumahaus, A.

2011-04-01

364

Observation and modelling of OH and HO2 concentrations in the Pearl River Delta 2006: a missing OH source in a VOC rich atmosphere  

NASA Astrophysics Data System (ADS)

Ambient OH and HO2 concentrations were measured by laser induced fluorescence (LIF) during the PRIDE-PRD2006 (Program of Regional Integrated Experiments of Air Quality over the Pearl River Delta, 2006) campaign at a rural site downwind of the megacity of Guangzhou in Southern China. The observed OH concentrations reached daily peak values of (15-26) × 106 cm-3 which are among the highest values so far reported for urban and suburban areas. The observed OH shows a consistent high correlation with j(O1D) over a broad range of NOx conditions. The correlation cannot be reproduced by model simulations, indicating that OH stabilizing processes are missing in current models. The observed OH exhibited a weak dependence on NOx in contrast to model predictions. While modelled and measured OH agree well at NO mixing ratios above 1 ppb, a continuously increasing underprediction of the observed OH is found towards lower NO concentrations, reaching a factor of 8 at 0.02 ppb NO. A dependence of the modelled-to-measured OH ratio on isoprene cannot be concluded from the PRD data. However, the magnitude of the ratio fits into the isoprene dependent trend that was reported from other campaigns in forested regions. Hofzumahaus et al. (2009) proposed an unknown OH recycling process without NO, in order to explain the high OH levels at PRD in the presence of high VOC reactivity and low NO. Taking a recently discovered interference in the LIF measurement of HO2 into account, the need for an additional HO2 ? OH recycling process persists, but the required source strength may be up to 20% larger than previously determined. Recently postulated isoprene mechanisms by Lelieveld et al. (2008) and Peeters and Müller (2010) lead to significant enhancements of OH expected for PRD, but an underprediction of the observed OH by a factor of two remains at low NO (0.1-0.2 ppb). If the photolysis of hydroperoxy aldehydes from isoprene is as efficient as proposed by Peeters and Müller (2010), the corresponding OH formation at PRD would be more important than the primary OH production from ozone and HONO. While the new isoprene mechanisms need to be confirmed by laboratory experiments, there is probably need for other, so far unidentified chemical processes to explain entirely the high OH levels observed in Southern China.

Lu, K. D.; Rohrer, F.; Holland, F.; Fuchs, H.; Bohn, B.; Brauers, T.; Chang, C. C.; Häseler, R.; Hu, M.; Kita, K.; Kondo, Y.; Li, X.; Lou, S. R.; Nehr, S.; Shao, M.; Zeng, L. M.; Wahner, A.; Zhang, Y. H.; Hofzumahaus, A.

2012-02-01

365

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.

366

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

NASA Astrophysics Data System (ADS)

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 industrial activity. Monitoring was conducted in two seasons inside and outside of 159 residences in industrial, urban and suburban cities located in southeast Michigan, USA. Passive samplers were deployed at each location, and analyzed for 98 compounds. Outdoors, 46 different VOCs were detected. Benzene, toluene, p, m-xylene and carbon tetrachloride had the highest concentrations (medians from 1 to 2 ?g m -3). Concentrations were elevated in winter in the suburban community, and levels were the highest in the industrial community. Indoors, 53 VOCs were detected, and benzene, toluene, p, m-xylene, n-heptane, ?-pinene and d-limonene had the highest concentrations (medians from 1 to 17 ?g m -3). Seasonal changes were small or inconsistent. Median indoor levels among the three communities generally followed outdoor rankings. Indoor/outdoor ratios varied from 1 to 10 for most compounds, but up to 100 for several compounds, e.g., d-limonene. Over a quarter of residences had benzene, naphthalene, chloroform and carbon tetrachloride at levels giving a chronic lifetime cancer risk above 10 -5 and sometimes much higher; outdoors, these compounds gave risks exceeding 10 -6. The study identifies a number of indoor emission sources associated with specific and sometimes very high VOC exposures, reports on several VOCs that have not been measured in previous indoor and outdoor studies, and shows the importance of both indoor and outdoor sources. Measured concentrations were at an intermediate level with respect to recent measurements elsewhere in the US, suggesting that study results are broadly representative.

Jia, Chunrong; Batterman, Stuart; Godwin, Christopher

367

Characteristics and photochemical potentials of volatile organics emission from stack exhaust gas of industrial processes  

SciTech Connect

The main objective of this project was to measure the main volatile organic compounds (VOCs) in stack gas from the downstream petrochemical plants. Six pollution sources of industrial processes, including Acrylonitrile-Butadiene-Styrene (ABS), Vinyl Chloride(VC), Polyvinyl Chloride (PVC), Acrylic Resin, para-Terephthalic Acid (PTA) and Polyurethane (PU) synthetic manufacturing processes, were measured by using USEPA Method 18. The concentration and emission rate database of twenty-seven VOCs has been established. Fifty-two selected stacks were sampled and analyzed for VOCs. Analysis of emission factors and characteristics of the twenty-seven VOCs in these stacks show that the emission characteristics are various among different industrial processes. The order of the single-stack VOCs average emission factor are ABS (1.109 lbs VOCs/ton-ABS; 22 stacks) {gt} Acrylic Resin (0.651 lbs VOCs/ton-acrylic resin; 7 stacks) {gt} PU Synthetic (0.606 lbs VOCs/ton-PU synthetic; 4 stacks) {gt} PTA (0.054 lbs VOCs/ton-PTA; 4 stacks) {gt} PVC (0.014 lbs VOCs/ton-PVC; 11 stacks) {gt} VC ({lt} 0.001; 4 stacks) manufacturing processes. The emission factors of VOC in AP-42 database for the processes of are 5 to 40 times higher than those of VOCs in this research. Because of the equipment of pollutant control setting up before the emitted exhaust gas, their average emission factors in these measured processes are almost lower than those of VOCs in AP-42 database. Compared with the characteristics of VOCs, there is little similarity in VOC characteristics for the stacks of six processes between the results from this research and the data from US EPA SPECIATE data system. Furthermore, according to maximum incremental reactivities (MIR) of VOCs probed into photochemical reaction potentials, the results show that those of PTA manufacturing process have an ozone formation potential of 2.33 g O{sub 3}/g VOCs, which is higher than other processes.

Hsu, Y.C.; Tsai, J.H.; Lin, T.C.; Cheng, C.C.; Huang, Y.H.

1999-07-01

368

Aerostat-Lofted Instrument Platform and Sampling Method for Determination of Emissions from Open Area Sources  

EPA Science Inventory

Sampling emissions from open area sources, particularly sources of open burning, is difficult due to fast dilution of emissions and safety concerns for personnel. Representative emission samples can be difficult to obtain with flaming and explosive sources since personnel safety ...

369

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...

370

Source location of the Uranus smooth low-frequency emission  

NASA Astrophysics Data System (ADS)

Two very different source locations, polar and equatorial, have been suggested in the literature for the smooth low frequency emission from Uranus, detected by the Voyager 2 Planetary Radio Astronomy experiment. These possibilities are considered by studying the occultation of possible source regions by the planet with respect to the spacecraft. It is shown that a polar source region over a limited range of magnetic longitude can be excluded, while a polar source distributed along all magnetic longitudes is compatible with visibility studies. However, comparison of observations with computed intensity contours, for polar and equatorial sources, definitely favors the equatorial source model.

Rabl, G. K. F.; Ladreiter, H. P.; Rucker, H. O.; Leblanc, Y.

1991-07-01

371

Gap-filling of VOC flux data for deriving annual budgets: Case study at a mountain meadow  

NASA Astrophysics Data System (ADS)

Although the biosphere is currently thought to be the main source for atmospheric volatile organic compounds (VOCs) longer time series of VOC measurements are barely available and the accuracy VOC modeling approaches still suffers from a lack of flux measurement data. However, long-term VOC flux data sets could provide a way to improve the quality of modeling approaches and make a first step towards a better VOC quantification. We used VOC flux data of methanol, acetone, acetaldehyde and the monoterpenes, which were measured by means of a proton transfer reaction - mass spectrometer PTR-MS utilising the disjunct eddy covariance method (vDEC) above an intensively managed mountain grassland in Stubai Valley (Austria), to compare the performance of four different gap filling approaches and to get complete annual time series of the VOCs for the years 2009 and 2011. Assuming a zero flux from the grassland during the winter period, when the meadow is usually covered by snow, the average cumulative VOC fluxes above the grassland show with 103 mg C m-2 in the year 2009 and 464 mg C m-2 in the year 2011 a high inter-annual variability. The gap filling using the filling method which performs best on the data introduced mean errors of 20 mg C m-2 in 2009 and 13 mg C m-2 in 2011. Methanol was with average cumulative emission fluxes of 375 mg C m-2 and 442 mg C m-2 during the year 2009 the main compound contributing to the VOC balance during both years. The cumulative fluxes of methanol using the four different gap-filling approaches agreed within a range smaller than 7 percent in 2009 and 2 percent in 2011. During the first year (2009) the cumulative deposition fluxes of monoterpenes (on average 317 mg C m-2) turned out to have also a big influence on the overall VOC balance (its cumulative flux variation depending on the used gap filling method was less than 10 percent). All other compounds showed fluxes which were below 10 percent of the methanol emission flux in 2009 while flux contribution of the non-methanol compounds was less than 5 percent of the total budget in 2011.

Bamberger, Ines; Hörtnagl, Lukas; Hansel, Armin; Wohlfahrt, Georg

2013-04-01

372

Spacecraft mass spectrometer ion source employing field emission cathodes  

NASA Technical Reports Server (NTRS)

An ion source that utilizes a pair of thin-film field emission cathodes to provide current for electric impact ionization is studied. The field emission cathodes are composed of microscopically small needle tips and an extraction electrode; the cathodes generate a 200-eV, 0.1-mA electron beam. The multistep process for the manufacturing of the field emission cathodes is examined. The operation of the ion source, which ionizes atoms and molecules that enter the mass spectrometer with a ram velocity of about 80 km/sec, is described.

Curtis, C. C.; Hsieh, K. C.

1986-01-01

373

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

374

CRITICAL REVIEW OF OPEN SOURCE PARTICULATE EMISSION MEASUREMENTS: FIELD COMPARISON  

EPA Science Inventory

The report gives results of a review of sampling and analytical procedures used by various testing firms to quantify particulate emissions from open sources; e.g., roads and storage piles. Seven firms, who account for nearly 100 percent of all open source data in the literature, ...

375

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...

376

Snowmobile contributions to mobile source emissions in Yellowstone National Park.  

PubMed

Increases in the number of winter visitors to Yellowstone National Park during the past decade have raised concerns over the environmental impacts of snowmobiling in the park. During the 1998-99 season, more than 62,000 snowmobile and 1300 snow coach trips entered the park. Using the University of Denver's vehicle exhaust remote-sensing equipment, 1385 measurements of carbon monoxide (CO) and hydrocarbon (HC) emissions were collected from in-use snowmobiles at the west and south entrances to the park. Overall means of 392 +/- 4 g CO and 237 +/- 1 g HC were observed per kilogram of fuel consumed. In addition, using an ultraviolet monochromator, 460 measurements of toluene emissions were collected with a mean of 39 +/- 1 g toluene/kg of fuel. Using these data, a mobile source emissions inventory based on fuel use for Yellowstone National Park shows that snowmobiles account for 27% of the annual emissions of carbon monoxide and 77% of annual emissions of hydrocarbons using an equivalent best estimate for the summer mobile source emissions. Use of oxygenated fuels in snowmobiles was found to reduce CO emissions by 13.2 +/- 6.5% without an observed effect on HC emissions. Liquid-cooled sleds were found to have HC emissions 9.5 +/- 2.2% higher than those from fan-cooled sleds because of the increased intake and exhaust port sizes required in the larger liquid-cooled engines, which increases blowby in the 2-stroke engines. PMID:11478237

Bishop, G A; Morris, J A; Stedman, D H

2001-07-15

377

The infrared emission bands. III - Southern IRAS sources  

NASA Technical Reports Server (NTRS)

Airborne 5-8-micron spectra of southern IRAS sources are presented which display the strong PAH emission features. The sources studied include those in a previous paper (Cohen et al, 1986) and NGC 6302, HR 4049, and CPD -56 deg 8032. A good correlation is found between the intensity ratio of the 7.7-micron feature relative to the FIR dust continuum and nebular C/O ratio, supporting a carbonaceous carrier for these emission features. In addition, a weak PAH band is detected near 5.2 microns in several sources.

Cohen, Martin; Tielens, A. G. G. M.; Bregman, Jesse; Witteborn, Fred C.; Allamandola, L. J.; Wooden, Diane H.; Rank, David M.

1989-01-01

378

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

NASA Technical Reports Server (NTRS)

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.

1992-01-01

379

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.

380

Source location of acoustic emission in diesel engines  

Microsoft Academic Search

This paper is the third in a series developing methods of mapping acoustic emission (AE) signals and wave propagation in engines and focuses on source location techniques for the multi-source signals on relatively complex structures typical of machinery applications. Two source location techniques, a traditional wave velocity-based and an AE energy-based technique, using triangular sensor arrays, are used to locate

P. Nivesrangsan; J. A. Steel; R. L. Reuben

2007-01-01

381

Emission rates of benzene and ammonia area sources determined by spectroscopic remote measurements and inverse dispersion modeling  

NASA Astrophysics Data System (ADS)

The emission rates of diffuse and heterogeneous distributed sources are difficult to determine because point measurements are not representative. Therefore a method was further developed to determine gaseous emission rates by measurements of path-integrated mixing ratios with open-path spectroscopic systems in the exhaust plume (VOC, NH3, CH4, N2O, CO, CO2) and of meteorological parameters. Inverse dispersion modeling is used to quantify the emission rates afterwards with these data. The measurements are performed by Fourier Transform Infrared (FTIR) spectroscopy and Differential Optical Absorption Spectroscopy (DOAS) at 50 to 500 m optical path lengths about 1 to 20 m above ground level. The measurement accuracy for greenhouse gases and ammonia is about plus or minus 10% and for BTX about plus or minus 30%. The whole method was validated at a livestock building with a single exhaust chimney. The Gaussian model PAL was applied for inverse modeling to investigate limited pieces of land and isolated facilities in flat terrain. Including the accuracy of the dispersion simulations the determined emission rates have an error margin of about plus or minus 30%. Results of measurement campaigns are discussed as emission rates of ammonia from slurry spreading as well as of benzene from gas stations and a tank farm.

Schaefer, Klaus; Emeis, Stefan M.; Stockhause, Martina; Sedlmaier, Achim; Hoffmann, Herbert; Depta, Georg; Gronauer, Andreas

1999-02-01

382

X-Ray Emission from Compact Sources  

SciTech Connect

This paper presents a review of the physical parameters of neutron stars and black holes that have been derived from X-ray observations. I then explain how these physical parameters can be used to learn about the extreme conditions occurring in regions of strong gravity, and present some recent evidence for relativistic effects seen in these systems. A glossary of commonly used terms and a short tutorial on the names of X-ray sources are also included.

Cominsky, L

2004-03-23

383

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

2011-01-01

384

Pulsed, atmospheric pressure plasma source for emission spectrometry  

DOEpatents

A low-power, plasma source-based, portable molecular light emission generator/detector employing an atmospheric pressure pulsed-plasma for molecular fragmentation and excitation is described. The average power required for the operation of the plasma is between 0.02 W and 5 W. The features of the optical emission spectra obtained with the pulsed plasma source are significantly different from those obtained with direct current (dc) discharge higher power; for example, strong CH emission at 431.2 nm which is only weakly observed with dc plasma sources was observed, and the intense CN emission observed at 383-388 nm using dc plasma sources was weak in most cases. Strong CN emission was only observed using the present apparatus when compounds containing nitrogen, such as aniline were employed as samples. The present apparatus detects dimethylsulfoxide at 200 ppb using helium as the plasma gas by observing the emission band of the CH radical. When coupled with a gas chromatograph for separating components present in a sample to be analyzed, the present invention provides an apparatus for detecting the arrival of a particular component in the sample at the end of the chromatographic column and the identity thereof.

Duan, Yixiang; Jin, Zhe; Su, Yongxuan

2004-05-11

385

Modeling study of natural emissions, source apportionment, and emission control of atmospheric mercury  

NASA Astrophysics Data System (ADS)

Mercury (Hg) is a toxic pollutant and is important to understand its cycling in the environment. In this dissertation, a number of modeling investigations were conducted to better understand the emission from natural surfaces, the source-receptor relationship of the emissions, and emission reduction of atmospheric mercury. The first part of this work estimates mercury emissions from vegetation, soil and water surfaces using a number of natural emission processors and detailed (LAI) Leaf Area Index data from GIS (Geographic Information System) satellite products. East Asian domain was chosen as it contributes nearly 50% of the global anthropogenic mercury emissions into the atmosphere. The estimated annual natural mercury emissions (gaseous elemental mercury) in the domain are 834 Mg yr-1 with 462 Mg yr-1 contributing from China. Compared to anthropogenic sources, natural sources show greater seasonal variability (highest in simmer). The emissions are significant, sometimes dominant, contributors to total mercury emission in the regions. The estimates provide possible explanation for the gaps between the anthropogenic emission estimates based on activity data and the emission inferred from field observations in the regions. To understand the contribution of domestic emissions to mercury deposition in the United States, the second part of the work applies the mercury model of Community Multi-scale Air Quality Modeling system (CMAQ-Hg v4.6) to apportion the various emission sources attributing to the mercury wet and dry deposition in the 6 United States receptor regions. Contributions to mercury deposition from electric generating units (EGU), iron and steel industry (IRST), industrial point sources excluding EGU and IRST (OIPM), the remaining anthropogenic sources (RA), natural processes (NAT), and out-of-boundary transport (BC) in domain was estimated. The model results for 2005 compared reasonably well to field observations made by MDN (Mercury Deposition Network) and CAMNet (Canadian Atmospheric Mercury Measurement Network). The model estimated a total deposition of 474 Mg yr-1 to the CONUS (Contiguous United States) domain, with two-thirds being dry deposited. Reactive gaseous mercury contributed the most to 60% of deposition. Emission speciation distribution is a key factor for local deposition as contribution from large point sources can be as high as 75% near (< 100 km) the emission sources, indicating that emission reduction may result in direct deposition decrease near the source locations. Among the sources, BC contributes to about 68% to 91% of total deposition. Excluding the BC's contribution, EGU contributes to nearly 50% of deposition caused by CONUS emissions in the Northeast, Southeast and East Central regions, while emissions from natural processes are more important in the Pacific and West Central regions (contributing up to 40% of deposition). The modeling results implies that implementation of the new emission standards proposed by USEPA (United States Environmental Protection Agency) would significantly benefit regions that have larger contributions from EGU sources. Control of mercury emissions from coal combustion processes has attracted great attention due to its toxicity and the emission-control regulations and has lead to advancement in state-of-the-art control technologies that alleviate the impact of mercury on ecosystem and human health. This part of the work applies a sorption model to simulate adsorption of mercury in flue gases, onto a confined-bed of activated carbon. The model's performances were studied at various flue gas flow rates, inlet mercury concentrations and adsorption bed temperatures. The process simulated a flue gas, with inlet mercury concentration of 300 ppb, entering at a velocity of 0.3 m s-1 from the bottom into a fixed bed (inside bed diameter of 1 m and 3 m bed height; bed temperature of 25 °C) of activated carbon (particle size of 0.004 m with density of 0.5 g cm-3 and surface area of 90.25 cm2 g -1). The model result demonstrated that a batch of activated carbon

Shetty, Suraj K.

386

Proton Transfer Reaction Time-of-Flight Mass Spectrometric (PTR-TOF-MS) determination of volatile organic compounds (VOCs) emitted from a biomass fire developed under stable nocturnal conditions  

NASA Astrophysics Data System (ADS)

Combustion of solid and liquid fuels is the largest source of potentially toxic volatile organic compounds (VOCs), which can strongly affect health and the physical and chemical properties of the atmosphere. Among combustion processes, biomass burning is one of the largest at global scale. We used a Proton Transfer Reaction “Time-of-Flight” Mass Spectrometer (PTR-TOF-MS), which couples high sensitivity with high mass resolution, for real-time detection of multiple VOCs emitted by burned hay and straw in a barn located near our measuring station. We detected 132 different organic ions directly attributable to VOCs emitted from the fire. Methanol, acetaldehyde, acetone, methyl vinyl ether (MVE), acetic acid and glycolaldehyde dominated the VOC mixture composition. The time-course of the 25 most abundant VOCs, representing ?85% of the whole mixture of VOCs, was associated with that of carbon monoxide (CO), carbon dioxide (CO2) and methane (CH4) emissions. The strong linear relationship between the concentrations of pyrogenic VOC and of a reference species (i.e. CO) allowed us to compile a list of emission ratios (ERs) and emission factors (EFs), but values of ER (and EF) were overestimated due to the limited mixing of the gases under the stable (non-turbulent) nocturnal conditions. In addition to the 25 most abundant VOCs, chemical formula and concentrations of the residual, less abundant VOCs in the emitted mixture were also estimated by PTR-TOF-MS. Furthermore, the evolution of the complex combustion process was described on the basis of the diverse types of pyrogenic gases recorded.

Brilli, Federico; Gioli, Beniamino; Ciccioli, Paolo; Zona, Donatella; Loreto, Francesco; Janssens, Ivan A.; Ceulemans, Reinhart

2014-11-01

387

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

Code of Federal Regulations, 2011 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...

2011-07-01

388

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

Code of Federal Regulations, 2012 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

389

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...

2010-07-01

390

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

Code of Federal Regulations, 2014 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...

2014-07-01

391

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

Code of Federal Regulations, 2013 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...

2013-07-01

392

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

393

Ice emission and the redshifts of submillimeter sources  

E-print Network

Observations at submillimeter wavelengths have revealed a population of sources thought to be at relatively large redshifts. The position of the 850 $\\mu$m passband on the Rayleigh-Jeans portion of the Planck function leads to a maximum redshift estimate of $z\\sim$4.5 since sources will not retain their redshift independent brightness close to the peak of the Planck function and thus drop out of surveys. Here we review evidence that ice absorption is present in the spectra of local ultraluminous infrared galaxies which are often taken as analogs for the 850 $\\mu$m source population. We consider the implication of this absorption for ice induced spectral structure at far infrared wavelengths and present marginal astronomical evidence that amorphous ice may have a feature similar to crystalline ice near 150 $\\mu$m. Recent corroborative laboratory evidence is supportive of this conclusion. It is argued that early metal enrichment by pair instability SN may lead to a high ice content relative to refractory dust at high redshift and a fairly robust detection of ice emission in a $z=6.42$ quasar is presented. It is further shown that ice emission is needed to understand the 450 $\\mu$m sources observed in the GOODS-N field. We are thus encouraged to apply far infrared ice emission models to the available observations of HDF 850.1, the brightest submillimeter source in the {\\it Hubble Deep Field}. We suggest that a redshift as large as 13 may need to be considered for this source, nearly a factor of three above the usual top estimate. Inclusion of the possibility of far infrared ice emission in the spectral energy distributions of model sources generally broadens the range of redshifts to be considered for submillimeter sources compared to models without ice emission.

C. C. Dudley; M. Imanishi; P. R. Maloney

2008-02-12

394

Control for NOx Emissions from Combustion Sources  

NASA Technical Reports Server (NTRS)

The Environmental Program Office at the Kennedy Space Center is interested in finding solutions and to promote research and development (R&D) that could contribute to solve the problems of air, soil, and groundwater contamination. This study is undertaken as part of NASA's environmental stewardship program. The objective of this study involves the removal of nitrogen oxides from the flue gases of the boilers at KSC using hydrogen peroxide. Phase 1 of this study have shown the potential of this process to be used as an alternative to the current methods of treatment used in the power industry. This report summarizes the research done during the ten-week summer program. During this period, support has been given to implement the modifications suggested for Phase 2 of the project, which focus on oxidation reactions carried at lower temperatures using an ultraviolet source. The redesign and assembly of the modifications for the scrubbing system was the main objective of this research.

PozodeFernandez, Maria E.; Collins, Michelle M.

2000-01-01

395

Source apportionment of volatile organic compounds measured in Edmonton, Alberta  

NASA Astrophysics Data System (ADS)

From 2003 to 2009, whole air samples were collected at two sites in Edmonton and analyzed for over 77 volatile organic compounds (VOCs). VOCs were sampled in the downtown area (Central site) and an industrial area on the eastern side of the city (East site). Concentrations of most VOCs were highest at the East site, with an average total VOC mass concentration of 221 ?g m-3. The average total VOC mass concentration at the Central site was 65 ?g m-3. The United States Environmental Protection Agency's positive matrix factorization receptor model (EPA PMF) was used to apportion ambient concentrations of VOCs into eleven factors, which were associated with emissions sources. On average, 94 and 99% of the measured mass were apportioned by PMF at the East and Central site, respectively. Factors include transportation combustion (gasoline and diesel), industrial sources (industrial evaporative, industrial feedstock, gasoline production/storage, industrial chemical use), mixed mobile and industrial (gasoline evaporative, fugitive butane), a biogenic source, a natural gas related source, and a factor that was associated with global background pollutants transported into the area. Transportation sources accounted for more than half of the reconstructed VOC mass concentration at the Central site, but less than 10% of the reconstructed mass concentration at the East site. By contrast, industrial sources accounted for ten times more of the reconstructed VOC mass concentration at the East site than at the Central site and were responsible for approximately 75% of the reconstructed VOC mass concentration observed at the East site. Of the six industrial factors identified at the East site, four were linked to petrochemical industry production and storage. The two largest contributors to the reconstructed VOC mass concentration at the East site were associated with fugitive emissions of volatile species (butanes, pentanes, hexane, and cyclohexane); together, these two factors accounted for more than 50% of the reconstructed VOC mass concentration at the East site in contrast to less than 2% of the reconstructed mass concentration at the Central site. Natural gas related emissions accounted for 10%-20% of the reconstructed mass concentration at both sites. Biogenic emissions and VOCs associated with well-mixed global background were less than 10% of the reconstructed VOC mass concentration at the Central site and less than 3% of the reconstructed mass concentration at the East site.

McCarthy, Michael C.; Aklilu, Yayne-Abeba; Brown, Steven G.; Lyder, David A.

2013-12-01

396

A compact PTR-ToF-MS instrument for airborne measurements of VOCs at high spatio-temporal resolution  

NASA Astrophysics Data System (ADS)

Herein, we report on the development of a compact proton-transfer-reaction time-of-flight mass spectrometer for airborne measurements of volatile organic compounds (VOCs). The new instrument resolves isobaric ions with a mass resolving power (m/?m) of ~ 1000, provides accurate m/z measurements (?m < 3 mDa), records full mass spectra at 1 Hz and thus overcomes some of the major analytical deficiencies of quadrupole-MS based airborne instruments. 1 Hz detection limits for biogenic VOCs (isoprene, ?-pinene), aromatic VOCs (benzene, toluene, xylenes) and ketones (acetone, methyl ethyl ketone) range from 0.05 to 0.12 ppbV, making the instrument well-suited for fast measurements in the continental boundary layer. The instrument detects and quantifies VOCs in locally confined plumes (< 1km) which improves our capability of characterizing emission sources and atmospheric processing within plumes. A deployment during the NASA 2013 DISCOVER-AQ mission generated high vertical and horizontal resolution in situ data of VOCs and ammonia for validation of satellite retrievals and chemistry transport models.

Müller, M.; Mikoviny, T.; Feil, S.; Haidacher, S.; Hanel, G.; Hartungen, E.; Jordan, A.; Märk, L.; Mutschlechner, P.; Schottkowsky, R.; Sulzer, P.; Crawford, J. H.; Wisthaler, A.

2014-06-01

397