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1

[Anthropogenic VOC emission inventory and contribution from industrial sources in Ningbo].  

PubMed

Ningbo is an important industrial city in eastern China and is also the economic center in the south wing of the Yangtze River Delta (YRD). Recently, the VOC emissions from the local industrial activities and its effects on both the regional air quality and people's health were getting more and more attention. The anthropogenic VOC emission inventory of Ningbo in 2010 was established with collecting comprehensive activity data of anthropogenic sources. Furthermore, the industrial sectors were studied and the significant industries were identified with their contribution quantified. The result shows that the amount of anthropogenic VOC emission in Ningbo in 2010 is 176 kt. Industry, transportation and residential source are the most important VOC anthropogenic sources in Ningbo, which accounted for 62.0%, 17.2% and 15.5% respectively. Synthetic materials manufacturing and refined petroleum products manufacturing are the most important VOC emitting industries, which contributed 18.6% and 13.1% of the total VOC amount respectively, signifying the influence of these two industries to the VOC emissions in Ningbo. PMID:25244829

Li, Xuan; Wang, Xue-Song; Liu, Zhong; Wu, Liang; Weng, Yan-Bo; Hu, Jie

2014-07-01

2

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

3

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

4

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

5

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

Microsoft Academic Search

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,

V. Isidorov; M. Smolewska; Z. Tyszkiewicz

2009-01-01

6

Emission characteristics of VOCs from athletic tracks.  

PubMed

Dynamic and flow-through flux chambers are convenient tools for field measurements of gas or VOC emission flux from solid surfaces in the field. This study was undertaken to collect on site and quantify the emissions of volatile organic compounds (VOCs) released from athletic running tracks. Three typical types of tracks, one synthetic rubber and two tracks (types I and II) consisting mainly of polyurethane, were studied. They were all installed with adhesives and backings, both of which contributed significant amount of VOCs. VOCs released from the track surface were collected with a flux chamber and subsequently analyzed by a gas chromatograph/mass spectrometer (GC/MS). Also, for each track and at each selected time the emission flux and mass emission were measured on site under outdoor conditions over a period of 40 min. GC/MS analyses show that the VOCs emitted include 2-methyl furan, butanal, methyl ethyl ketone, benzene, heptane, methyl isobutyl ketone, toluene+octane, hexanal, nonane+ethylbenzene, xylenes+styrene, propyl benzene, decane, 1,3,5-trimethyl benzene, 1,2,4-trimethyl benzene, 1,2, 3-trimethyl benzene and undecane. Of these, hexanal was the common and principal compound for all three types of tracks. 2-Methyl furan and methyl isobutyl ketone were the characteristic compounds for the synthetic rubber and the type II of polyurethane tracks, respectively. In the field studies, no unique compounds were found in the type I of polyurethane tracks. For each of these three types of tracks the total-VOCs emission flux was correlated to the track age and track surface temperature. The results of multiple regression analysis showed good correlation. The type II polyurethane track had the highest decay rate, while the synthetic rubber track had the lowest decay rate. Two years after the track installation, the VOC concentrations measured at 1.5 m above the track, the breathing height of school children, were not significantly higher than the background levels. PMID:10611425

Chang, F H; Lin, T C; Huang, C I; Chao, H R; Chang, T Y; Lu, C S

1999-12-23

7

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...

8

HISTORIC EMISSIONS OF VOC AND NOX IN THE UNITED STATES FROM 1900 TO 1985  

EPA Science Inventory

The paper discusses historic emissions of volatile organic compounds (VOCs) and nitrogen oxides (NOx) in the U.S. from 1900 to 1985. otal VOC emissions have increased over the study period with peaks around 1930 and 1970. In 1900, transportation sources contributed 2 of the total...

9

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

PubMed

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

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

1998-01-01

10

Biofiltration: an innovative air pollution control technology for VOC emissions.  

PubMed

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 public sector sources. Control efficiencies of more than 90 percent have been achieved for many common air pollutants. Due to lower operating costs, biofiltration can provide significant economic advantages over other APC technologies if applied to off-gases that contain readily biodegradable pollutants in low concentrations. Environmental benefits include low energy requirements and the avoidance of cross media transfer of pollutants. This paper reviews the history and current status of biofiltration, outlines its underlying scientific and engineering principles, and discusses the applicability of biofilters for a wide range of specific emission sources. PMID:1958341

Leson, G; Winer, A M

1991-08-01

11

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...

12

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

13

EVALUATION OF VOC (VOLATILE CARBON) EMISSIONS FROM WASTEWATER SYSTEMS (SECONDARY EMISSIONS)  

EPA Science Inventory

The technical objective of this project was to obtain data for evaluating volatile carbon (VOC) emissions from wastewater treatment facilities for the synthetic organic chemicals manufacturing industry (SOCMI). VOC emissions data were obtained using the Concentration-Profile tech...

14

VOC EMISSIONS FROM AN AIR FRESHENER IN THE INDOOR ENVIRONMENT  

EPA Science Inventory

The paper describes results of tests, conducted in the U.S. Environmental Protection Agency (EPA) large chamber facility, that investigated emissions of volatile organic compounds (VOCS) from one electrical plug-in type air freshener with pine-scented refills. VOCs were measured ...

15

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

16

Quantifying VOC emissions for the strategic petroleum reserve.  

SciTech Connect

A very important aspect of the Department of Energy's (DOE's) Strategic Petroleum Reserve (SPR) program is regulatory compliance. One of the regulatory compliance issues deals with limiting the amount of volatile organic compounds (VOCs) that are emitted into the atmosphere from brine wastes when they are discharged to brine holding ponds. The US Environmental Protection Agency (USEPA) has set limits on the amount of VOCs that can be discharged to the atmosphere. Several attempts have been made to quantify the VOC emissions associated with the brine ponds going back to the late 1970's. There are potential issues associated with each of these quantification efforts. Two efforts were made to quantify VOC emissions by analyzing VOC content of brine samples obtained from wells. Efforts to measure air concentrations were mentioned in historical reports but no data have been located to confirm these assertions. A modeling effort was also performed to quantify the VOC emissions. More recently in 2011- 2013, additional brine sampling has been performed to update the VOC emissions estimate. An analysis of the statistical confidence in these results is presented here. Arguably, there are uncertainties associated with each of these efforts. The analysis herein indicates that the upper confidence limit in VOC emissions based on recent brine sampling is very close to the 0.42 ton/MMB limit used historically on the project. Refining this estimate would require considerable investment in additional sampling, analysis, and monitoring. An analysis of the VOC emissions at each site suggests that additional discharges could be made and stay within current regulatory limits.

Knowlton, Robert G.; Lord, David L.

2013-06-01

17

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...

18

ASSESSMENT OF VOC EMISSIONS FROM FIBERGLASS BOAT MANUFACTURING  

EPA Science Inventory

The report presents an assessment of volatile organic compound (VOC) emissions from fiberglass boat manufacturing. Description of the industry structure is presented, including estimates of the number of facilities, their size, and geographic distribution. The fiberglass boat m...

19

ASSESSMENT OF VOC EMISSIONS FROM FIBERGLASS BOAT MANUFACTURING  

EPA Science Inventory

The report presents an assessment of volatile organic compound (VOC) emissions from fiberglass boat manufacturing. escription of the industry structure is presented, including estimates of the number of facilities, their size, and geographic distribution. he fiberglass boat manuf...

20

A Novel New Approach to VOC and HAP Emission Control  

E-print Network

HAP (Hazardous Air Pollutant) and VOC (Volatile Organic Compound) thermal emission control devices (ECD) usually require large amounts of energy to operate. They also require large capital investments in heat recovery options and large amounts...

McGinness, M.

21

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

NASA Astrophysics Data System (ADS)

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

von Schneidemesser, Erika; Monks, Paul

2010-05-01

22

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

23

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

24

Using a source-receptor approach to characterise VOC behaviour in a French urban area influenced by industrial emissions. Part II: source contribution assessment using the Chemical Mass Balance (CMB) model.  

PubMed

In Part I of this study (Badol C, Locoge N, Leonardis T, Gallo JC. Using a source-receptor approach to characterise VOC behaviour in a French urban area influenced by industrial emissions, Part I: Study area description, data set acquisition and qualitative data analysis of the data set. Sci Total Environ 2007; submitted as companion manuscript.) the study area, acquisition of the one-year data set and qualitative analysis of the data set have been described. In Part II a source profile has been established for each activity present in the study area: 6 profiles (urban heating, solvent use, natural gas leakage, biogenic emissions, gasoline evaporation and vehicle exhaust) have been extracted from literature to characterise urban sources, 7 industrial profiles have been established via canister sampling around industrial plants (hydrocarbon cracking, oil refinery, hydrocarbon storage, lubricant storage, lubricant refinery, surface treatment and metallurgy). The CMB model is briefly described and its implementation is discussed through the selection of source profiles and fitting species. Main results of CMB modellings for the Dunkerque area are presented. (1) The daily evolution of source contributions for the urban wind sector shows that the vehicle exhaust source contribution varies between 40 and 55% and its relative increase at traffic rush hours is hardly perceptible. (2) The relative contribution of vehicle exhaust varies from 55% in winter down to 30% in summer. This decrease is due to the increase of the relative contribution of hydrocarbon storage source reaching up to 20% in summer. (3) The evolution of source contributions with wind directions has confirmed that in urban wind sectors the contribution of vehicle exhaust dominate with around 45-55%. For the other wind sectors that include some industrial plants, the contribution of industrial sources is around 60% and could reach 80% for the sector 280-310 degrees , which corresponds to the most dense industrial area. (4) The pollution in Dunkerque has been globally characterised taking into account the frequency of wind directions and contributions of sources in each wind direction for the whole year. It has been concluded that contribution of industrial sources is below 20% whereas vehicle exhaust contribution is superior to 40%. PMID:17936336

Badol, Caroline; Locoge, Nadine; Galloo, Jean-Claude

2008-01-25

25

Characterising sources and sinks of rural VOC in eastern France.  

PubMed

Fifty non-methane hydrocarbons (NMHC) and seventeen carbonyl compounds were measured at a French rural site from 1997 to 2001, as part of the EMEP programme. Data handling was based on an original source-receptor approach. First, the examination of the levels and trends was completed by the comparison of the seasonal distribution of rural and urban VOC/acetylene ambient ratios. This analysis has shown that most of the compounds derived from mixing and photochemical transformation of mid-range transported urban pollutants from the downwind urban area. Then, identified sources and sinks were temporally apportioned. Urban air masses mixing explains, at least, 80% of the wintertime levels of anthropogenic NMHC and isoprene. In summer, photochemistry dominates the day-to-day distribution of anthropogenic NMHC whilst summertime isoprene is also controlled by in-situ biogenic emissions. Then, the results of C(1)-C(3) carbonyls were discussed with respect to their direct biogenic and anthropogenic emissions and photochemical production through the [carbonyl/auto-exhaust tracers] emission ratio. Diluted vehicle exhaust emissions mainly contribute to the total content of lower aldehydes in winter while other processes control lower ketones. Secondary production is predominant in summer with at least a 50% high intensity. Its dependence upon temperature and radiation is also demonstrated. Finally, the importance of the primary and secondary biogenic production of acetone and formaldehyde is assessed. In particular, biogenic contribution would explain 37 +/- 25% of acetone levels in summer. PMID:15488583

Borbon, Agnès; Coddeville, Patrice; Locoge, Nadine; Galloo, Jean-Claude

2004-11-01

26

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...

27

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

28

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

NASA Astrophysics Data System (ADS)

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

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

2011-05-01

29

Contribution of traffic emissions to indoor airborne VOCs  

SciTech Connect

The contribution of nearby vehicle traffic to indoor airborne volatile organic compound levels and to personal exposures was examined to determine the importance of this source. Indoor and outdoor levels of selected VOCs, aldehydes, ketones, and ethanol were measured at 10 homes in Toronto, on sidewalks near the traffic source, indoors and in the backyards or balconies of apartments (outdoors). Concurrently, air exchange rates were measured at each home with a perfluorocarbon tracer method. All the residences were within 1 km of urban intersections with traffic counts of more than 20,000 vehicles per day. Average concentrations of hexane, 1,3-butadiene, toluene, benzene and propionaldehyde decreased in the order: street level > indoor > outdoor. These compounds occur in vehicle emissions, and the contribution of outdoor to indoor concentrations ranged from 24 to 88 % suggesting that traffic emissions contributed to indoor pollutant level through the process of air exchange. For other compounds different trends were observed. Indoors concentrations were greater than outdoors for ethylacetate, tetrachlorethane, pinene, limonene, 1,4-dichlorobenzene, naphthalene, formaldehyde, acetaldehyde and ethanol, for example. These compounds are common in consumer products, and the contribution of outdoor to indoor concentrations ranged from 2 to 44%. The differences in street and backyard (outdoor) concentrations for some compounds were large due to the presence of nearby vehicles at street level sampling sites, indicating that the impact of traffic on human exposures (pedestrians on sidewalks and occupants of vehicles) is potentially large, compared to the impact of general background urban air pollutants.

Otson, R.; Williams, D.T. [Health Canada, Ottawa, Ontario (Canada); Fellin, P. [Conor Pacific Environmental Ltd., Toronto, Ontario (Canada)

1998-12-31

30

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...

31

VOC Emissions from the Potential Biofuel Crop, Switchgrass  

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

32

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

NASA Astrophysics Data System (ADS)

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

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

33

[Characteristics of volatile organic compounds (VOCs) emission from electronic products processing and manufacturing factory].  

PubMed

Based on the EPA method T0-11 and 14/15 for measurement of toxic organics in air samples, fast VOCs detector, Summa canister and DNPH absorbent were used to determine the VOCs concentrations and the compositions in the ambient air of the workshops for different processes as well as the emission concentration in the exhaust gas. In all processes that involved VOCs release, concentrations of total VOCs in the workshops were 0.1-0.5 mg x m(-3), 1.5-2.5 mg x m(-3) and 20-200 mg x m(-3) for casting, cutting and painting respectively. Main compositions of VOCs in those workshops were alkanes, eneynes, aromatics, ketones, esters and ethers, totally over 20 different species. The main compositions in painting workshop were aromatics and ketones, among which the concentration of benzene was 0.02-0.34 mg x m(-3), toluene was 0.24-3.35 mg x m(-3), ethyl benzene was 0.04-1.33 mg x m(-3), p-xylene was 0.13-0.96 mg x m(-3), m-xylene was 0.02-1.18 mg x m(-3), acetone was 0.29-15.77 mg x m(-3), 2-butanone was 0.06-22.88 mg x m(-3), cyclohexene was 0.02-25.79 mg x m(-3), and methyl isobutyl ketone was 0-21.29 mg x m(-3). The VOCs emission from painting process was about 14 t x a(-1) for one single manufacturing line, and 840 t x a(-1) for the whole factory. According to the work flows and product processes, the solvent used during painting process was the main source of VOCs emission, and the exhaust gas was the main emission point. PMID:24640894

Cui, Ru; Ma, Yong-Liang

2013-12-01

34

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

35

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 ...

36

VOC source identification from personal and residential indoor, outdoor and workplace microenvironment samples in EXPOLIS-Helsinki, Finland  

NASA Astrophysics Data System (ADS)

Principal component analyses (varimax rotation) were used to identify common sources of 30 target volatile organic compounds (VOCs) in residential outdoor, residential indoor and workplace microenvironment and personal 48-h exposure samples, as a component of the EXPOLIS-Helsinki study. Variability in VOC concentrations in residential outdoor microenvironments was dominated by compounds associated with long-range transport of pollutants, followed by traffic emissions, emissions from trees and product emissions. Variability in VOC concentrations in environmental tobacco smoke (ETS) free residential indoor environments was dominated by compounds associated with indoor cleaning products, followed by compounds associated with traffic emissions, long-range transport of pollutants and product emissions. Median indoor/outdoor ratios for compounds typically associated with traffic emissions and long-range transport of pollutants exceeded 1, in some cases quite considerably, indicating substantial indoor source contributions. Changes in the median indoor/outdoor ratios during different seasons reflected different seasonal ventilation patterns as increased ventilation led to dilution of those VOC compounds in the indoor environment that had indoor sources. Variability in workplace VOC concentrations was dominated by compounds associated with traffic emissions followed by product emissions, long-range transport and air fresheners. Variability in VOC concentrations in ETS free personal exposure samples was dominated by compounds associated with traffic emissions, followed by long-range transport, cleaning products and product emissions. VOC sources in personal exposure samples reflected the times spent in different microenvironments, and personal exposure samples were not adequately represented by any one microenvironment, demonstrating the need for personal exposure sampling.

Edwards, Rufus D.; Jurvelin, J.; Koistinen, K.; Saarela, K.; Jantunen, M.

37

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

Microsoft Academic Search

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

Chia-Hsien Yen; Jao-Jia Horng

2009-01-01

38

Preliminary insights into the chemical composition and emissions of urban VOCs in the East Mediterranean  

NASA Astrophysics Data System (ADS)

The Mediterranean region is an area where polluted air masses coming from Eastern and Central Europe increase air pollution, particularly during stagnation periods, together with intense solar radiation. It was demonstrated that the eastern coast of the Mediterranean Sea suffers from this kind of phenomena. Favorable weather conditions, remote sources, high urban and biogenic emissions lead to the formation of secondary pollutants (ozone and secondary organic aerosols, SOA), which may have significant impacts on health and climate. However, data are sparse in this region. The ECOCEM (Emission and Chemistry of Organic Carbon in the East Mediterranean - Beirut) project aims to improve our understanding of air pollution in this area by studying the composition of the gaseous and particulate phases in Beirut (Lebanon). Beirut is located on the eastern border of the Mediterranean basin. The goal of the project, which is taking place over two intensive field campaigns (July 2011 and February 2012), is to provide valuable observations on the composition and the temporal evolution of organics (summer versus winter),to identify and quantify the relative importance of sources of volatile organic compounds (VOCs) and aerosols (SOA) and to study the role of VOCs in the first oxidation steps of SOA formation. For that purpose, a large suite of primary and secondary VOCs (>60) were measured during the summertime campaign (July 2nd to July 17th 2011) at one suburban site in Beirut. Techniques encompass off-line sampling on carbonaceous sorbent tubes (2-hour time resolution) and liquid coil scrubbing (1-hour time resolution), an on-line GCFID (1-hour time resolution) and a PTR-MS (4-min time resolution). We will discuss here the atmospheric composition of VOCs in relation with their emissions. In particular, these data provide useful constraints to evaluate the first temporally and spatially resolved national emission inventory that was built for the year 2010. Preliminary results show that the summer mixing ratios of anthropogenic VOCs (aromatics and light alkanes) and secondary VOCs (acetaldehyde) mixing ratios could be 2 to 4 times higher than northern latitude megacities (Paris and Los Angeles). While traffic seems to control the diurnal variability of primary VOCs, other significant sources are suspected to contribute to aromatics and light alkane levels.

Sauvage, S.; Borbon, A.; Afif, C.; Bechara, J.; Leonardis, T.; Fronval, I.; Waked, A.; Brioude, J.; Locoge, N.

2011-12-01

39

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

40

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

41

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

PubMed

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

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

2013-10-01

42

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

43

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

44

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

45

Temperature and light dependence of the VOC emissions of Scots pine  

Microsoft Academic Search

The volatile organic compound (VOC) emission rates of Scots pine (Pinus sylvestris L.) were measured from trees growing in a natural forest environment at two locations in Finland. The observed total VOC emission rates varied between 21 and 874 ngg-1 h-1 and 268 and 1670 ngg-1 h-1 in southern and northern Finland, respectively. A clear seasonal cycle was detected with

V. Tarvainen; H. Hakola; H. Hellén; J. Bäck; P. Hari; M. Kulmala

2005-01-01

46

Evaluation of speciated VOC emission factors for Air Force hush houses  

SciTech Connect

Data published in: ``Engine and Hush House Emissions from a TF30-P109 Jet Engine Tested at Cannon Air Force Base, NM`` by Radian Corporation and ``Aircraft Emissions. Characterization: TF41-A2, TF30-P103 , and TF30-P109 Engines`` by Battelle are reviewed and compared. Specifically CO, NO{sub x}, and VOC emission factors using EPA Method 19 are addressed, with comparisons between JP-4 and JP-8 jet fuels. CO and NO{sub x} emissions for JP-4 and JP-8 jet fuels were found to be essentially the same. VOC emission data exhibited high variability. Problems inherent in speciated VOC emission testing are discussed. A limiting of speciated VOC emission testing, with emission factor estimation based on fuel content is proposed.

Sullivan, P.D. [Armstrong Lab., Tyndall AFB, FL (United States); Stevens, D.K. [Utah State Univ., Logan, UT (United States)

1997-12-31

47

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

48

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

49

PREDICTING THE EMISSIONS OF INDIVIDUAL VOCS FROM PETROLEUM-BASED INDOOR COATINGS  

EPA Science Inventory

The indoor use of petroleum-based coating materials may cause elevated volatile organic compound (VOC) concentrations. This paper presents a newly developed mass transfer model for estimating the emissions of individual VOCs from freshly coated surfaces. Results of a four-step va...

50

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

51

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

NASA Astrophysics Data System (ADS)

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

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

2012-11-01

52

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

NASA Astrophysics Data System (ADS)

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

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

2011-01-01

53

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

54

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

55

Comparing the VOC emissions between air-dried and heat-treated Scots pine wood  

NASA Astrophysics Data System (ADS)

The emissions of volatile organic compounds (VOCs) from air-dried Scots pine wood and from heat-treated Scots pine wood were compared with GC-MS analysis. Air-dried wood blocks released about 8 times more total VOCs than heat-treated (24 h at 230°C) ones. Terpenes were clearly the main compound group in the air-dried wood samples, whereas aldehydes and carboxylic acids and their esters dominated in the heat-treated wood samples. Only 14 compounds out of 41 identified individual compounds were found in both wood samples indicating considerable changes in VOC emission profile during heat-treatment process. Of individual compounds ?-pinene, 3-carene and hexanal were the most abundant ones in the air-dried wood. By contrast, in the heat-treated wood 2-furancarboxaldehyde, acetic acid and 2-propanone were the major compounds of VOC emission. Current emission results reveal that significant chemical changes have occurred, and volatile monoterpenes and other low-molecular-weight compounds have evaporated from the wood during the heat-treatment process when compared to air-dried wood. Major chemical changes detected in VOC emissions are explained by the thermal degradation and oxidation of main constituents in wood. The results suggest that if heat-treated wood is used in interior carpentry, emissions of monoterpenes are reduced compared to air-dried wood, but some irritating compounds might be released into indoor air.

Manninen, Anne-Marja; Pasanen, Pertti; Holopainen, Jarmo K.

56

A STUDY ON THE VOCS EMISSION RATES OF HOME ELECTRICAL APPLIANCES  

Microsoft Academic Search

Home electrical appliances release hazardous chemical substances produced by the effects of heating during their operation. The present study investigated the emission rates of chemical substances on home electrical appliances such as microwave ovens, vacuum cleaners, electric heaters, electric blankets, multimedia players, electronic dictionaries, MD players and notebook PCs. The VOCs emission rates of comparatively small products were measured using

Atsuo Nozaki; Yasunori Narita

57

A Survey of California Plant Species With a Portable VOC Analyzer for Biogenic Emission Inventory Development  

Microsoft Academic Search

An accurate estimate of the magnitude of biogenic volatile organic compound (BVOC) emissions relative to anthropogenic VOC emissions in California's airsheds is critical for formulating effective strategies to reduce concentrations of fine particles, ozone, and other secondary air pollutants which affect human health and reduce yields of agricultural crops. However, California's natural landscapes contain more than 5800 listed species, and

J. F. Karlik; A. M. Winer

2001-01-01

58

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

EPA Science Inventory

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

59

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...

60

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

61

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

62

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

63

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...

64

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...

65

Copyright (c) 2000 Water Environment Federation. All Rights Reserved. Odors and VOC Emissions 2000  

E-print Network

Copyright (c) 2000 Water Environment Federation. All Rights Reserved. Odors and VOC Emissions 2000S) is an odorous gas produced from animal manure. It is toxic to humans and animals at high emitted from animal facilities. It is colorless but has a very pungent odor similar to rotten eggs

Ni, Jiqin "Jee-Chin"

66

MEASUREMENT OF VOC EMISSIONS FROM WOOD REMEDIAL TREATMENT: CHAMBER TESTS AND FIELD EXPERIMENTS  

E-print Network

are presented in Table 1. The area specific air flow rate was chosen as representative of the surface of a frame Test parameters CSTB CTBA Test chamber Glass, 0.05 m3 (CLIMPAQ) Stainless steel, 1 m3 Temperature 23MEASUREMENT OF VOC EMISSIONS FROM WOOD REMEDIAL TREATMENT: CHAMBER TESTS AND FIELD EXPERIMENTS F

Paris-Sud XI, Université de

67

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

EPA Science Inventory

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

68

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...

69

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

70

Observational constraints on biogenic VOC emission model estimates (Invited)  

NASA Astrophysics Data System (ADS)

Chemistry and transport models require accurate estimates of biogenic volatile organic compound (BVOC) emissions in order to simulate the atmospheric constituents controlling air quality and climate, such as ozone and particles, and so the uncertainties associated with BVOC estimates may be limiting the development of effective air quality and climate management strategies. BVOC emission models include driving variables and algorithms that span scales from the leaf level to entire landscapes. While considerable effort has been made to improve BVOC emission models in the past decades, there have been relatively few attempts to quantify the uncertainties associated with these estimates or to rigorously assess emission modeling approaches. This presentation will summarize the availability of observations that can be used to constrain BVOC emission models including flux measurements (leaf enclosure, above canopy tower, and aircraft platforms) and ambient concentrations of BVOC and their products. Results from studies targeting specific BVOC emission processes (e.g., the response of isoprene emission to drought and the response of monoterpene emissions to bark beetle attack) will be shown and the application of these observations for BVOC model evaluation will be discussed. In addition, the results from multi-scale BVOC emission studies (leaf enclosure, whole canopy flux tower, regional aircraft eddy covariance) will be presented and a approach for incorporating these observations into a community model testbed will be described and used to evaluate regional BVOC emission models.

Guenther, A. B.

2013-12-01

71

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.; Muller, M.; Schnitzhofer, R.; Karl, T.; Graus, M.; Bamberger, I.; Hortnagl, L.; Brilli, F.; Wohlfahrt, G.; Hansel, A.

2013-01-01

72

Factors influencing pollutant gas emissions of VOC recuperative incinerators—Large-scale parametric study  

Microsoft Academic Search

This work establishes quantitative links between the operation parameters—plus one geometrical parameter—and the gas pollutant emissions of a recuperative incinerator (RI) of volatile organic compounds (VOCs). Using experimental design methodology, and based on a large number of experiments carried out on a half-industrial-scale pilot unit, mathematical expressions are established to calculate each of the pollutant emissions from the value of

S. Salvador; Y. Kara; J.-M. Commandré

2006-01-01

73

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

74

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

75

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 ...

76

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

NASA Astrophysics Data System (ADS)

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

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

2005-12-01

77

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...

78

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

79

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

80

Temperature and light dependence of the VOC emissions of Scots pine  

NASA Astrophysics Data System (ADS)

The volatile organic compound (VOC) emission rates of Scots pine (Pinus sylvestris L.) were measured from trees growing in a natural forest environment at two locations in Finland. The emission rate measurements were carried out using a dynamic flow through technique with samples collected on adsorbent tubes and analyzed using thermodesorption followed by a gas chromatograph with a mass-selective detector (GC-MS). The standard emission potentials (at 303.15 K and 1000 µmol photons m-2 s-1) were calculated for the measured compounds using nonlinear regression to fit the experimental data to temperature and light dependent emission algorithms. The observed total VOC emission rates varied between 21 and 874 ng/g(dw)*h and 268 and 1670 ng/g(dw)*h in southern and northern Finland, respectively. A clear seasonal cycle was detected with high emission rates in early spring, a decrease of the emissions in late spring and early summer, high emissions again in late summer, and a gradual decrease in autumn. The main emitted compounds were ?3-carene (southern Finland) and ?- and ?-pinene (northern Finland), with approximate relative contributions of 60-70% and 60-85% of the total observed monoterpene emission rates, respectively. Sesquiterpene (?-caryophyllene) and 2-methyl-3-buten-2-ol (MBO) emissions were initiated in early summer at both sites. The observed MBO emission rates were between 1 and 3.5% of the total monoterpene emission rates. The sesquiterpene emission rates varied between 2 and 5% of the total monoterpene emission rates in southern Finland, but were high (40%) in northern Finland in spring. Most of the measured emission rates were found to be well described by the temperature dependent emission algorithm. The calculated standard emission potentials were high in spring and early summer, decreased somewhat in late summer, and were high again towards autumn. The experimental coefficient ? ranged from 0.025 to 0.19 (average 0.10) in southern Finland, with strongest temperature dependence in spring and weakest in late summer. Only the emission rates of 1,8-cineole were found to be both light and temperature dependent. However, there were irregularities with the performance of the exponential temperature algorithm, and our results suggest that especially during the spring recovery period of the vegetation there may be several different processes contributing to the VOC emissions of Scots pine.

Tarvainen, V.; Hakola, H.; Hellén, H.; Bäck, J.; Hari, P.; Kulmala, M.

2004-10-01

81

Temperature and light dependence of the VOC emissions of Scots pine  

NASA Astrophysics Data System (ADS)

The volatile organic compound (VOC) emission rates of Scots pine (Pinus sylvestris L.) were measured from trees growing in a natural forest environment at two locations in Finland. The observed total VOC emission rates varied between 21 and 874 ngg-1 h-1 and 268 and 1670 ngg-1 h-1 in southern and northern Finland, respectively. A clear seasonal cycle was detected with high emission rates in early spring, a decrease of the emissions in late spring and early summer, high emissions again in late summer, and a gradual decrease in autumn.

The main emitted compounds were ?3-carene (southern Finland) and ?- and ?-pinene (northern Finland), with approximate relative contributions of 60-70% and 60-85% of the total observed monoterpene emission rates, respectively. Sesquiterpene (?-caryophyllene) and 2-methyl-3-buten-2-ol (MBO) emissions were initiated in early summer at both sites. The observed MBO emission rates were between 1 and 3.5% of the total monoterpene emission rates. The sesquiterpene emission rates varied between 2 and 5% of the total monoterpene emission rates in southern Finland, but were high (40%) in northern Finland in spring.

Most of the measured emission rates were found to be well described by the temperature dependent emission algorithm. The calculated standard emission potentials were high in spring and early summer, decreased somewhat in late summer, and were high again towards autumn. The experimental coefficient ? ranged from 0.025 to 0.19 (average 0.10) in southern Finland, with strongest temperature dependence in spring and weakest in late summer. Only the emission rates of 1,8-cineole were found to be both light and temperature dependent.

Tarvainen, V.; Hakola, H.; Hellén, H.; Bäck, J.; Hari, P.; Kulmala, M.

2005-03-01

82

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

83

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

PubMed

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

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

2013-08-01

84

Numerical modeling of VOC emissions from ozone reactions with human-worn clothing in an aircraft cabin  

E-print Network

the emissions of several major VOCs, including acetone, 4-oxopentanal (4-OPA), nonanal, and decanal, from ozone). These compounds are emitted as gases from a variety of indoor materials such as paints, furniture, and building

Chen, Qingyan "Yan"

85

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

86

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

87

Field emission electron source  

DOEpatents

A novel field emitter material, field emission electron source, and commercially feasible fabrication method is described. The inventive field emission electron source produces reliable electron currents of up to 400 mA/cm.sup.2 at 200 volts. The emitter is robust and the current it produces is not sensitive to variability of vacuum or the distance between the emitter tip and the cathode. The novel emitter has a sharp turn-on near 100 volts.

Zettl, Alexander Karlwalter (Kensington, CA); Cohen, Marvin Lou (Berkeley, CA)

2000-01-01

88

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

89

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

Microsoft Academic Search

Proton transfer reaction mass spectrometry (PTR-MS) volatile organic compound (VOC) measurements were made at the Centre for Atmospheric Research Experiments at Egbert, Ontario, over a five week period in May to June 2007. VOCs were also analyzed by gas chromatography and with a fluorescence detector sensitive to formaldehyde. This is a well positioned site for contrasting biogenic versus anthropogenic sources.

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

2009-01-01

90

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

NASA Astrophysics Data System (ADS)

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

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

2011-07-01

91

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

NASA Astrophysics Data System (ADS)

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

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

2011-11-01

92

A standard reference for chamber testing of material VOC emissions: Design principle and performance  

NASA Astrophysics Data System (ADS)

Environmental chambers are widely used to test formaldehyde and other volatile organic compound (VOC) emissions from indoor materials and furniture. However, there is a lack of a proven method to assess the precision of the test results of the chamber system. In this paper, we describe a new standard reference, LIFE (liquid-inner tube diffusion-film-emission), to address this problem. This reference has the following salient features: (1) Constant emission rate, with less than 3.0% change with an ambient airflow speed (>0.014 m/s) at furniture emission range (0.1-1.0 mg/m 3 in a 30 m 3 chamber with air change rate of 1/h) under standard chamber test conditions as specified by ISO 16000-9 (23 °C, 50% RH); (2) Long duration of emissions, on the order of 1000 h; (3) Easy to store, apply and maintain. The design principle and criteria of the LIFE reference are presented. An analytical model and dimensionless analysis were applied to optimize the factors influencing the emission rate, and experiments were conducted to validate the analytical results. In addition, the equivalent emission parameters of the reference, i.e., the initial emittable concentration, the diffusion coefficient and the partition coefficient, were determined through a three-parameter optimizing regression. This can then be used to check the reliability of a chamber method for testing these three parameters. The developed standard reference should prove useful for calibrating chamber systems for indoor material/furniture VOC emissions tests.

Wei, Wenjuan; Zhang, Yinping; Xiong, Jianyin; Li, Mu

2012-02-01

93

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

94

Characterization of VOC Sources during the Texas Air Quality Study 2000 Using Proton-Transfer-Reaction Mass Spectrometry  

NASA Astrophysics Data System (ADS)

We used Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) for continuous real-time monitoring of volatile organic compounds (VOCs) at a site near the Houston Ship Channel during the Texas Air Quality Study 2000. Anthropogenic aromatics, alkenes, methanol, acetaldehyde, formaldehyde, acetone/propanal, a C7-Ketone, HCN and acrylonitrile were the most prominent compounds observed. Propene was the most abundant light-weight hydrocarbon detected by this technique, and was highly correlated with its oxidation products, formaldehyde and acetaldehyde, with typical propene-acetaldehyde ratios close to 1 in propene-dominated plumes. In the case of aromatic species the high time resolution of the obtained dataset helped in identifying different anthropogenic sources (e.g. industrial from urban emissions) and testing current emission inventories. In addition, a comparison with results from complimentary techniques (gas chromatography, differential optical absorption spectroscopy) was used to assess the selectivity of this on-line technique in a complex urban and industrial VOC matrix and give an interpretation of mass scans obtained by `soft' chemical ionization using proton-transfer via H3O+.

Karl, T.; Jobson, T.; William, K.; Williams, E.; Stutz, J.; Goldan, P.; Fall, R.; Fehsenfeld, F.; Lindinger, W.

2002-12-01

95

A Framework for Estimating Groundwater Concentrations of VOCs Emanating from a Vadose Zone Source (Invited)  

NASA Astrophysics Data System (ADS)

Soil vapor extraction (SVE) is a prevalent remediation approach for volatile organic compounds (VOCs) in the vadose zone. To support selection of an appropriate endpoint, i.e., the VOC concentration at which the remedy can be terminated for site closure or for transition to another remedy, an evaluation is needed to determine whether vadose zone contamination has been diminished sufficiently to protect groundwater. When vapor-phase diffusive transport is an important component of the overall contaminant fate and transport from a vadose zone source, a numerical analysis has shown that the expected groundwater concentration is controlled by a limited set of parameters, including site-specific dimensions, vadose zone properties, and source characteristics. Based on that approach, a framework was developed for estimating the VOC concentration in groundwater emanating from a vadose zone source. The framework uses results from three-dimensional VOC transport simulations for a matrix of parameter value combinations covering a range of potential site conditions. Interpolation and scaling processes are then applied to estimate contaminant concentrations at compliance (monitoring) wells for specific site conditions of interest. The framework has been incorporated into a user-friendly Microsoft Excel-based spreadsheet tool, which is made available to the public. The spreadsheet methodology provides a less computationally intensive alternative to three-dimensional multiphase modeling, while still allowing for parameter sensitivity and uncertainty analyses. In many cases, the framework spreadsheet may be appropriate to consider the effect of a diminishing vadose zone source over time. In this presentation, the conceptual model and spreadsheet development will be discussed.

Oostrom, M.; Truex, M.; Rice, A. K.; Carroll, K. C.; Simon, M. A.; Becker, D.

2013-12-01

96

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

97

Pulsed Corona Plasma Technology for Treating VOC Emissions from Pulp Mills  

SciTech Connect

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

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

2004-07-28

98

Advanced pumped storage hydroelectric power may reduce NO{sub x} and VOC emissions  

SciTech Connect

As a severe ozone nonattainment area, the New York/New Jersey metropolitan area faces the difficult challange of reducing emissions of nitrogen oxides (NO{sub x}) and volatile organic compounds (VOCs), the primary precursors of ground-level ozone. An ambitious, $2.4 billion undertaking, known as the Mt. Hope project, may help the metropolitan area - and the entire Mid-Atlantic Ozone Transport Region (OTR) - attain ozone compliance. The project includes a new 2,000-MW electricity storage facility, which would allow thermal power plants in the region to run more efficiently and reduce NO{sub x} and VOC emissions, especially at times of critical ozone levels. The Mt. Hope project is the subject of a recent study that analyzed, potential reductions in ozone precursors from project implementation. According to the study, NO{sub x} emissions could be reduced by up to 50 tons per day and $91 million per year could potentially be saved if the project is implemented. Advanced pumped storage (APS) improves significantly on the conventional method. The Mt. Hope project, for example, is expected to consume only 22% more electricity than it generates. APS facilities are designed to switch from power-receiving to power-generating modes frequently in response to demand - up to 20 times a day in the Mt. Hope design. 1 ref., 1 fig.

NONE

1995-05-01

99

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. ...

100

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

101

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...

102

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...

103

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

104

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

PubMed

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

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

2011-01-01

105

A Survey of California Plant Species With a Portable VOC Analyzer for Biogenic Emission Inventory Development  

NASA Astrophysics Data System (ADS)

An accurate estimate of the magnitude of biogenic volatile organic compound (BVOC) emissions relative to anthropogenic VOC emissions in California's airsheds is critical for formulating effective strategies to reduce concentrations of fine particles, ozone, and other secondary air pollutants which affect human health and reduce yields of agricultural crops. However, California's natural landscapes contain more than 5800 listed species, and urban landscapes contain hundreds more. A taxonomic method has been proposed to assign BVOC emission rate measurements to unmeasured species, but data were needed for additional plant families and genera to further develop the taxonomic approach. Replicate samples of live foliage of more than 250 plant species were placed in plastic bags, in both light and darkened conditions, and the BVOC emissions measured with a calibrated portable analyzer unit (PAU), and categorized as low, medium or high. To validate the PAU approach we compared our PAU-measured BVOC emissions for approximately 60 plant species with published values based on gas chromatography (GC) and GC-mass spectrometry and found them to be well correlated. For approximately 200 plant species not previously measured, the PAU data indicated that plant taxonomy served as a useful method for characterizing the magnitude and nature of emissions (either light or dark, or both). The method employed was more suited for detecting isoprene emissions, due to their relatively higher magnitudes, than emissions of monoterpenes or oxygenated compounds. The results provide further evidence that plant taxonomy can serve as a useful guide for generalizing the emissions behavior of many, but not all, plant families and genera.

Karlik, J. F.; Winer, A. M.

2001-12-01

106

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

107

Effect of bake-out on reducing VOC emissions and concentrations in a residential housing unit with a radiant floor heating system  

Microsoft Academic Search

This study analyzed the effect of bake-out on reducing VOC emissions and indoor concentrations in a residential housing unit with a radiant floor heating system. The effect of an elevated temperature on VOC emissions from a wallpaper assembly, plywood flooring assembly, and particle board (as an example of furniture material) was investigated in a small-scale chamber. Simultaneously, in the residential

Dong Hwa Kang; Dong Hee Choi; Seung Min Lee; Myoung Souk Yeo; Kwang Woo Kim

2010-01-01

108

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 ...

109

CONTROL OF INDUSTRIAL VOC (VOLATILE ORGANIC COMPOUND) EMISSIONS BY CATALYTIC INCINERATION. VOLUME 1. ASSESSMENT OF CATALYTIC INCINERATION AND COMPETING CONTROLS  

EPA Science Inventory

The report is part of a two-phase EPA effort to assess the performance, suitability, and costs of various technologies to control emissions of volatile organic compounds (VOCs). In Phase 1, information was assembled from the literature on the use and cost of using catalytic incin...

110

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...

111

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...

112

Simulation of VOC emissions from treatment of an industrial wastewater in a biological treatment system  

SciTech Connect

At an Air Products` chemical plant, wastewater is treated biologically prior to its discharge to a nearby river. The wastewater treatment system consists of a large aeration basin with gravity clarification for solids-liquid separation. The aeration basin utilizes floating surface aerators for providing oxygen and mixing energy and treats an average of 1.2 MGD of wastewater flow. The biological system operates at a 4 day HRT and F/M (TOC basis) of 0.06 and consistently produces a final effluent low in BOD and TSS. A number of pertinent organic compounds such as acetaldehyde, methanol, methyl acetate and vinyl acetate are present in the waste feed to the bio-system. EPA modeling data for a completely mixed biological system suggests that a large fraction of the organic compounds in the feed may be air stripping causing high reportable SARA emission numbers. It is believed that EPA model overstates the VOC emissions to air from a well operated biological system. This project was initiated to simulate the biological wastewater treatment system and to determine relative emission of the four named compounds to air.

Agarwal, R.K.; Larson, M.A. [Air Products and Chemicals, Inc., Allentown, PA (United States)

1995-12-31

113

Reduction of Volatile Organic Compound Emissions from Automobile Refinishing,  

National Technical Information Service (NTIS)

Automobile refinishing (repainting) is a source of volatile organic compound (VOC) emissions. The study was conducted to evaluate available techniques that can be used to reduce VOC emissions from this source. The document provides information on the step...

C. Athey, C. Hester, M. McLaughlin, R. M. Neulicht, M. B. Turner

1988-01-01

114

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...

115

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...

116

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...

117

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

118

Catalytic oxidation of VOC`s and air toxics  

SciTech Connect

Catalytic oxidation for VOC control of stationary sources has been in use since the 1940`s for energy recovery and odor control. Widespread use of catalytic oxidation, as a means for controlling emissions began in earnest in the early 1970`s with the passage of the Clean Air Act of 1970. Since that time, catalytic technology has undergone many improvements and advancements. Some of these include higher destruction efficiencies at lower temperatures, poison resistance, enhanced durability and the ability to effectively control halogenated hydrocarbon compounds. This is particularly important for meeting the Title III requirements, since many of the air toxics regulated under Title III are halogenated VOC`s. This paper will describe catalytic oxidation, how it works, its benefits and limitations, its cost relative to thermal, and describe recent technology advances.

Lassen, M.A.; Chu, W. [Johnson Matthey, Wayne, PA (United States)

1995-12-31

119

Temperature and moisture effect on spore emission in the fungal biofiltration of hydrophobic VOCs.  

PubMed

The effect of temperature and moisture on the elimination capacity (EC), CO(2) production and spore emission by Fusarium solani was studied in biofilters packed with vermiculite and fed with n- pentane. Three temperatures (15, 25 and 35°C) were tested and the highest average EC (64 g m(-3) h(-1)) and lower emission of spores (2.0 × 10(3) CFU m(-3) air) were obtained at 25°C. The effect of moisture content of the packing material indicates that the highest EC (65 g m(-3) h(-1)) was obtained at 50 % moisture. However, lowest emission (1.3 × 10(3) CFU m(-3) air) was obtained at 80 % moisture. Furthermore, the results show that a slight decrease in spore emission was found with increasing moisture content. In all cases, the depletion of the nitrogen source in the biofilter induced the sporulation, a decay of the EC and increased spore emission. PMID:22375544

Vergara-Fernández, Alberto; Salgado-Ísmodes, Vanida; Pino, Miguel; Hernández, Sergio; Revah, Sergio

2012-01-01

120

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

121

Comparison of VOC emissions between air-dried and heat-treated Norway spruce ( Picea abies), Scots pine ( Pinus sylvesteris) and European aspen ( Populus tremula) wood  

NASA Astrophysics Data System (ADS)

Heat-treated wood is an increasingly popular decoration material. Heat-treatment improves dimensional stability of the wood and also prevents rot fungus growth. Although production of heat-treated wood has been rapidly increasing, there is only little information about the VOC emissions of heat-treated wood and its possible influences on indoor air quality. In the present study, VOC emissions from three untreated (air-dried) and heat-treated wood species were compared during a four weeks test period. It appeared that different wood species had clearly different VOC emission profiles. Heat-treatment was found to decrease VOC emissions significantly and change their composition. Especially, emissions of terpenes decreased from softwood samples and aldehydes from European aspen samples. Emissions of total aldehydes and organic acids were at the same level or slightly higher from heat treated than air-dried softwood samples. In agreement with another recent study, the emissions of furfural were found to increase and those of hexanal to decrease from all the wood species investigated. In contrast to air-dried wood samples, emissions of VOCs were almost in steady state from heat treated wood samples even in the beginning of the test.

Hyttinen, Marko; Masalin-Weijo, Marika; Kalliokoski, Pentti; Pasanen, Pertti

2010-12-01

122

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...

123

Assessment of Neurobehavioral Response in Humans to Low-Level Volatile Organic Compound (VOC) Sources.  

National Technical Information Service (NTIS)

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

D. A. Otto

1991-01-01

124

Emission rates of C 8-C 15 VOCs from seaweed and sand in the inter-tidal zone at Mace Head, Ireland  

NASA Astrophysics Data System (ADS)

Emission fluxes for a range of C 8-C 15 volatile organic compounds (VOCs) were determined from the seaweed Fucus spiralis (spiral wrack) and an adjacent sand surface during low tide on the coastline of Mace Head, Ireland. These two surface types, assessed using dynamic flux chamber systems, are typical of the Mace Head inter-tidal zone. A range of n-alkanes and oxygenates were routinely identified in the measurement of chamber air. Examination of the odd/even n-alkane ratios and use of the carbon preference index (CPI) suggested a biogenic source for these compounds (CPIs >2 in for all samples). Fluxes of n-pentadecane, the most predominant n-alkane, ranged from 0.2 to 5.1 ?g m -2 h -1 (0.9-24 nmol m -2 h -1), while oxygenates such as nonanal and decanal had fluxes ranging from <0.1 to 4.4 ?g m -2 h -1 (<0.1-31 nmol m -2 h -1) and <0.1 to 4.6 ?g m -2 h -1 (<0.1-30 nmol m -2 h -1), respectively. Seaweed emission rates for n-pentadecane were correlated with photosynthetically active radiation (PAR) ( rs=0.94) while emissions from sand showed correlation with temperature ( rs=0.85). This suggests a possible biochemical route controlling the release of n-pentadecane from spiral wrack, and temperature-driven volatilisation from sand. Volatilisation from residual seawater trapped in the sand may explain the comparable flux of both n-alkanes and oxygenates from this surface. Unlike the n-alkanes, oxygenate fluxes from sand correlate with PAR, suggesting a photodependent production from organic carbon residues present in seawater. Comparison with previous flux estimates from coastal seawater indicates that the two source types ( Fucus spiralis and bare sand) are significant but not dominant sources of these VOCs.

Sartin, J. H.; Halsall, C. J.; Hayward, S.; Hewitt, C. N.

125

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

126

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

127

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.

128

Survey of cadmium emission sources  

SciTech Connect

This document presents technical data used to support decision making on the need for listing cadmium under Section 108(a)(1), Section 112(b)(1)(A), or Section 111(b)(1)(A) as required by Section 122 of the Clean Air Act, as amended in 1977. Data are presented describing potential sources of cadmium emissions, control techniques used for cadmium emission control, estimated controlled and uncontrolled cadmium emissions, estimated ambient air quality, and compliance status. The results of special dispersion modeling are presented for incineration, interaction of smelters, and for interaction of sources in the New York City - New Jersey area.

Not Available

1981-09-01

129

Southern California Edison's (SCE) Research Program for Industrial Volatile Organic Compound (VOC) Emissions Control  

E-print Network

capabilities coupled with external consultant support to survey the technological options available. Technology alternatives considered include process modifications, application improvements, and add-on control systems. Our final step was to select... through our Research program of pilot demonstrations. The two key elements that are necessary for the success of this VOC program are the understanding of AQMD regulations as they affect our customers and the knowledge of our customers' process...

Sung, R. D.; Cascone, R.; Reese, J.

130

Evaluation of VOC recovery strategies  

Microsoft Academic Search

Many manufactured items receive surface coatings for decoration and\\/or protection against damage. In a number of places along\\u000a the production line emissions of (VOC) Volatile Organic Compounds can occur. Because VOC are a major contributor to photochemical\\u000a smog, control of VOC emissions is a major concern for the industries' commitment to the environment. Approaches for process\\u000a optimisation have a long

J. Geldermann; M. Treitz; H. Schollenberger; O. Rentz

2006-01-01

131

SOURCES OF COPPER AIR EMISSIONS  

EPA Science Inventory

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

132

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

NASA Astrophysics Data System (ADS)

This study investigated the impacts of seasonal and regional variability in biogenic volatile organic compounds (BVOCs) on surface ozone over the Pearl River delta (PRD) region in southern China in 2010 with the WRF-Chem/MEGAN (Weather Research and Forecasting coupled with Chemistry/Model of Emissions of Gases and Aerosols from Nature) modeling system. Compared to observations in the literature and this study, MEGAN tends to predict reasonable BVOC emissions in summer, but may overestimate isoprene emissions in autumn, even when the local high-resolution land-cover data and observed emission factors of BVOCs from local plant species are combined to constrain the MEGAN BVOC emissions model. With the standard MEGAN output, it is shown that the impact of BVOC emissions on the surface ozone peak is ~3 ppb on average with a maximum of 24.8 ppb over the PRD region in autumn, while the impact is ~10 ppb on average, with a maximum value of 34.0 ppb in summer. The areas where surface ozone is sensitive to BVOC emissions are different in autumn and in summer, which is primarily due to the change of prevailing wind over the PRD; nevertheless, in both autumn and summer, the surface ozone is most sensitive to the BVOC emissions in the urban area because the area is usually VOC-limited. Three additional experiments concerning the sensitivity of surface ozone to MEGAN input variables were also performed to assess the sensitivity of surface ozone to MEGAN drivers, and the results reveal that land cover and emission factors of BVOCs are the most important drivers and have large impacts on the predicted surface ozone.

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

2013-12-01

133

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

SciTech Connect

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

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

2011-03-16

134

Volatile organic compounds (VOCs) in urban air: How chemistry affects the interpretation of positive matrix factorization (PMF) analysis  

NASA Astrophysics Data System (ADS)

Volatile organic compounds (VOCs) were measured online at an urban site in Beijing in August-September 2010. Diurnal variations of various VOC species indicate that VOCs concentrations were influenced by photochemical removal with OH radicals for reactive species and secondary formation for oxygenated VOCs (OVOCs). A photochemical age-based parameterization method was applied to characterize VOCs chemistry. A large part of the variability in concentrations of both hydrocarbons and OVOCs was explained by this method. The determined emission ratios of hydrocarbons to acetylene agreed within a factor of two between 2005 and 2010 measurements. However, large differences were found for emission ratios of some alkanes and C8 aromatics between Beijing and northeastern United States secondary formation from anthropogenic VOCs generally contributed higher percentages to concentrations of reactive aldehydes than those of inert ketones and alcohols. Anthropogenic primary emissions accounted for the majority of ketones and alcohols concentrations. Positive matrix factorization (PMF) was also used to identify emission sources from this VOCs data set. The four resolved factors were three anthropogenic factors and a biogenic factor. However, the anthropogenic factors are attributed here to a common source at different stages of photochemical processing rather than three independent sources. Anthropogenic and biogenic sources of VOCs concentrations were not separated completely in PMF. This study indicates that photochemistry of VOCs in the atmosphere complicates the information about separated sources that can be extracted from PMF and the influence of photochemical processing must be carefully considered in the interpretation of source apportionment studies based upon PMF.

Yuan, Bin; Shao, Min; de Gouw, Joost; Parrish, David D.; Lu, Sihua; Wang, Ming; Zeng, Limin; Zhang, Qian; Song, Yu; Zhang, Jianbo; Hu, Min

2012-12-01

135

Modeled and observed ozone sensitivity to mobile-source emissions in Mexico City  

NASA Astrophysics Data System (ADS)

The emission characteristics of mobile sources in the Mexico City Metropolitan Area (MCMA) have changed significantly over the past few decades in response to emission control policies, advancements in vehicle technologies and improvements in fuel quality, among others. Along with these changes, concurrent non-linear changes in photochemical levels and criteria pollutants have been observed, providing a unique opportunity to understand the effects of perturbations of mobile emission levels on the photochemistry in the region using observational and modeling approaches. The observed historical trends of ozone (O3), carbon monoxide (CO) and nitrogen oxides (NOx) suggest that ozone production in the MCMA has changed from a low to a high VOC-sensitive regime over a period of 20 years. Comparison of the historical emission trends of CO, NOx and hydrocarbons derived from mobile-source emission studies in the MCMA from 1991 to 2006 with the trends of the concentrations of CO, NOx, and the CO/NOx ratio during peak traffic hours also indicates that fuel-based fleet average emission factors have significantly decreased for CO and VOCs during this period whereas NOx emission factors do not show any strong trend, effectively reducing the ambient VOC/NOx ratio. This study presents the results of model analyses on the sensitivity of the observed ozone levels to the estimated historical changes in its precursors. The model sensitivity analyses used a well-validated base case simulation of a high pollution episode in the MCMA with the mathematical Decoupled Direct Method (DDM) and the standard Brute Force Method (BFM) in the 3-D CAMx chemical transport model. The model reproduces adequately the observed historical trends and current photochemical levels. Comparison of the BFM and the DDM sensitivity techniques indicates that the model yields ozone values that increase linearly with NOx emission reductions and decrease linearly with VOC emission reductions only up to 30% from the base case. We further performed emissions perturbations from the gasoline fleet, diesel fleet, all mobile (gasoline plus diesel) and all emission sources (anthropogenic plus biogenic). The results suggest that although large ozone reductions obtained in the past were from changes in emissions from gasoline vehicles, currently significant benefits could be achieved with additional emission control policies directed to regulation of VOC emissions from diesel and area sources that are high emitters of alkenes, aromatics and aldehydes.

Zavala, M.; Lei, W.; Molina, M. J.; Molina, L. T.

2009-01-01

136

Modeled and observed ozone sensitivity to mobile-source emissions in Mexico City  

NASA Astrophysics Data System (ADS)

The emission characteristics of mobile sources in the Mexico City Metropolitan Area (MCMA) have changed significantly over the past few decades in response to emission control policies, advancements in vehicle technologies and improvements in fuel quality, among others. Along with these changes, concurrent non-linear changes in photochemical levels and criteria pollutants have been observed, providing a unique opportunity to understand the effects of perturbations of mobile emission levels on the photochemistry in the region using observational and modeling approaches. The observed historical trends of ozone (O3), carbon monoxide (CO) and nitrogen oxides (NOx) suggest that ozone production in the MCMA has changed from a low to a high VOC-sensitive regime over a period of 20 years. Comparison of the historical emission trends of CO, NOx and hydrocarbons derived from mobile-source emission studies in the MCMA from 1991 to 2006 with the trends of the concentrations of CO, NOx, and the CO/NOx ratio during peak traffic hours also indicates that fuel-based fleet average emission factors have significantly decreased for CO and VOCs during this period whereas NOx emission factors do not show any strong trend, effectively reducing the ambient VOC/NOx ratio. This study presents the results of model analyses on the sensitivity of the observed ozone levels to the estimated historical changes in its precursors. The model sensitivity analyses used a well-validated base case simulation of a high pollution episode in the MCMA with the mathematical Decoupled Direct Method (DDM) and the standard Brute Force Method (BFM) in the 3-D CAMx chemical transport model. The model reproduces adequately the observed historical trends and current photochemical levels. Comparison of the BFM and the DDM sensitivity techniques indicates that the model yields ozone values that increase linearly with NOx emission reductions and decrease linearly with VOC emission reductions only up to 30% from the base case. We further performed emissions perturbations from the gasoline fleet, diesel fleet, all mobile (gasoline plus diesel) and all emission sources (anthropogenic plus biogenic). The results suggest that although large ozone reductions obtained in the past were from changes in emissions from gasoline vehicles, currently significant benefits could be achieved with additional emission control policies directed to regulation of VOC emissions from diesel and area sources that are high emitters of alkenes, aromatics and aldehydes.

Zavala, M.; Lei, W. F.; Molina, M. J.; Molina, L. T.

2008-08-01

137

VOCs Speciation From Steam Boiler Stacks of Industries Located in Naucalpan  

Microsoft Academic Search

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

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

2007-01-01

138

Motor vehicle emission factors of NMHC, CO, NO{sub x} and VOCs pattern in photochemical reactions inside the tunnel  

SciTech Connect

Motor vehicle emission factors of CO, NO{sub x} and nonmethane hydrocarbons (NMHC) were measured inside the Chung-Cheng Tunnel of Kaohsiung in Taiwan. The results were compared with the corresponding values calculated by Mobile Taiwan-1.0 and Mobile-5b models. Concentrations of individual hydrocarbon species were also determined, and reactivity of organic species from motor vehicles calculated through use of MIR scale. Results show that the average emission factors of CO, NMHC, and NO{sub x} inside the Chung-Cheng Tunnel were 6.25, 1.51, and 1.02g/veh-km, respectively. The error range of the emission factors was 45%. Concentrations of isopentane, 2-methylpentane, benzene and toluene are the dominant species. Emission factors predicted by Mobile Taiwan-1.0 were much higher than those actually measured. However, values predicted by Mobile-5b did closely match the observed data. The MIR/VOCs ratios found inside the Tunnel differ significantly from those reported for Fort McHenry Tunnel and Tuscarora Tunnel, which is probably due to difference in driving patterns and fuel compositions.

Tsai, J.H.; Hsu, Y.C.; Chen, H.W. [National Cheng-Kung Univ., Tainan (Taiwan, Province of China); Lin, W.Y. [Tajen Junior College of Pharmacy, Pington (Taiwan, Province of China)

1998-12-31

139

Monoterpene emissions from rubber trees (Hevea brasiliensis) in a changing landscape and climate: chemical speciation and environmental control  

Microsoft Academic Search

Emissions of biogenic volatile organic compounds (VOCs) have important roles in ecophysiology and atmospheric chemistry at a wide range of spatial and temporal scales. Tropical regions are a major global source of VOC emissions and magnitude and chemical speciation of VOC emissions are highly plant-species specific. Therefore it is important to study emissions from dominant species in tropical regions undergoing

YONG-FENG W A NG; S USAN M. O WEN; Q ING-JUN L I; J O S E P P E NUELAS

140

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

141

CONTROL OF INDUSTRIAL VOC (VOLATILE ORGANIC COMPOUND) EMISSIONS BY CATALYTIC INCINERATION. VOLUME 5. CATALYTIC INCINERATOR PERFORMANCE AT INDUSTRIAL SITE C-3  

EPA Science Inventory

The report is part of a two-phase EPA effort to assess the performance, suitability, and costs of various technologies to control emissions of volatile organic compounds (VOCs). In Phase 1, information was assembled from the literature on the use and cost of using catalytic incin...

142

CONTROL OF INDUSTRIAL VOC (VOLATILE ORGANIC COMPOUND) EMISSIONS BY CATALYTIC INCINERATION. VOLUME 7. CATALYTIC INCINERATOR PERFORMANCE AT INDUSTRIAL SITE C-5  

EPA Science Inventory

The report is part of a two-phase EPA effort to assess the performance, suitability, and costs of various technologies to control emissions of volatile organic compounds (VOCs). In Phase 1, information was assembled from the literature on the use and cost of using catalytic incin...

143

CONTROL OF INDUSTRIAL VOC (VOLATILE ORGANIC COMPOUND) EMISSIONS BY CATALYTIC INCINERATION. VOLUME 8. CATALYTIC INCINERATOR PERFORMANCE AT INDUSTRIAL SITE C-6  

EPA Science Inventory

The report is part of a two-phase EPA effort to assess the performance, suitability, and costs of various technologies to control emissions of volatile organic compounds (VOCs). In Phase 1, information was assembled from the literature on the use and cost of using catalytic incin...

144

Development of a novel methodology for indoor emission source identification  

NASA Astrophysics Data System (ADS)

The objective of this study was to develop and evaluate a methodology to identify individual sources of emissions based on the measurements of mixed air samples and the emission signatures of individual materials previously determined by Proton Transfer Reaction-Mass Spectrometry (PTR-MS), an on-line analytical device. The methodology based on signal processing principles was developed by employing the method of multiple regression least squares (MRLS) and a normalization technique. Samples of nine typical building materials were tested individually and in combination, including carpet, ceiling material, gypsum board, linoleum, two paints, polyolefine, PVC and wood. Volatile Organic Compound (VOC) emissions from each material were measured in a 50-liter small-scale chamber. Chamber air was sampled by PTR-MS to establish a database of emission signatures unique to each individual material. The same task was performed to measure combined emissions from material mixtures for the application and validation of the developed signal separation method. Results showed that the proposed method could identify the individual sources under laboratory conditions with two, three, five and seven materials present. Further experiments and investigation are needed for cases where the relative emission rates among different compounds may change over a long-term period.

Han, K. H.; Zhang, J. S.; Knudsen, H. N.; Wargocki, P.; Chen, H.; Varshney, P. K.; Guo, B.

2011-06-01

145

Road-Network-Based Spatial Allocation of On-Road Mobile Source Emissions in the Pearl River Delta Region, China, and Comparisons with Population-Based Approach  

Microsoft Academic Search

Gridded air pollutant emission inventories are prerequisites for using air quality models to assess air pollution control strategies and predict air quality. A precise gridded emission inventory will help improve the accuracy of air quality simulation. Mobile source emissions are one of the major contributors to volatile organic compound (VOC) and nitrogen oxide (NOx) pollutants, the precursors of ozone formation.

Junyu Zheng; Wenwei Che; Xuemei Wang; Peter Louie; Liuju Zhong; Morton Barlaz; Jeff Chanton; Roger Green; Elizabeth Vega; Douglas Lowenthal; Hugo Ruiz; Elizabeth Reyes; John Watson; Judith Chow; Mar Viana; Xavier Querol; Andres Alastuey; Mark Gibson; Mathew Heal; David Bache; Andrew Hursthouse; Iain Beverland; Susanne Craig; Colin Clark; Mike Jackson; Nicholas Nussbaum; Dongzi Zhu; Hampden Kuhns; Claudio Mazzoleni; M.-C. Chang; Hans ller; David Sodeman; Sebastian Uppapalli; Melanie Sattler; Divya Garrepalli; Chandraprakash Nawal; Daniel Burgard; Melissa Provinsal; Lien-Te Hsieh; Ya-Fen Wang; Gia-Hao Kuo; Lin-Chi Wang; Guo-Ping Chang-Chien; Pedro Sanhueza; Monica Torreblanca; Luis Diaz-Robles; L. Schiappacasse; Maria Silva; Teresa Astete

2009-01-01

146

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

PubMed

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

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

2013-12-01

147

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

148

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

Microsoft Academic Search

An accurate estimate of the magnitude of biogenic volatile organic compound (BVOC) emissions in California's airsheds is critical for formulating effective strategies to reduce concentrations of fine particles, ozone, and other secondary air pollutants which affect human health and reduce yields of agricultural crops. However, California's natural and urban landscapes contain more than 6000 species, and the BVOC emissions from

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

2002-01-01

149

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

PubMed Central

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

2014-01-01

150

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

NASA Astrophysics Data System (ADS)

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

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

151

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 ...

152

Reduction of VOC emission from natural flours filled biodegradable bio-composites for automobile interior  

Microsoft Academic Search

Various experiments, such as the thermal extract (TE) method, field and emission cell (FLEC) method and 20L small chamber, were performed to examine the total volatile organic compound (TVOC) emissions from bio-composites. The TVOC of neat poly(lactic acid) (PLA) was ranged from 0.26mg\\/m2h to 4.11mg\\/m2h with increasing temperature. For both PLA bio-composites with pineapple flour and destarched cassava flour, the

Ki-Wook Kim; Byoung-Ho Lee; Sumin Kim; Hyun-Joong Kim; Ju-Ho Yun; Seung-Eul Yoo; Jong Ryeul Sohn

2011-01-01

153

Temperature and moisture effect on spore emission in the fungal biofiltration of hydrophobic VOCs  

Microsoft Academic Search

The effect of temperature and moisture on the elimination capacity (EC), CO2 production and spore emission by Fusarium solani was studied in biofilters packed with vermiculite and fed with n- pentane. Three temperatures (15, 25 and 35°C) were tested and the highest average EC (64 g m h) and lower emission of spores (2.0 × 10 CFU m air) were obtained at

Alberto Vergara-Fernández; Vanida Salgado-Ísmodes; Miguel Pino; Sergio Hernández; Sergio Revah

2012-01-01

154

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

155

C6-Green leaf volatiles trigger local and systemic VOC emissions in tomato  

E-print Network

an equimolar amount of methyl jasmonate triggered only local emissions of terpenes. Labeling studies with 13 CO acid (JA), its methyl ester, certain amino acid conjugates, Glc esters, and various hydroxylated forms and salicylic acid derivatives vary among plant species, C6-volatiles produced from the catalytic activity

Paré, Paul W.

156

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 ...

157

Biomass burning contributions to ambient VOCs species at a receptor site in the Pearl River Delta (PRD), China.  

PubMed

Ambient VOCs were measured by a proton transfer reaction-mass spectrometer (PTR-MS) at a receptor site in the Pearl River Delta (PRD) during October 19-November 18, 2008. Biomass burning plumes are identified by using acetonitrile as tracer, and enhancement ratios (ERs) of nine VOCs species relative to acetonitrile are obtained from linear regression analysis and the source-tracer-ratio method. Enhancement ratios determined by the two different methods show good agreement for most VOCs species. Biomass burning contributions are investigated by using the source-tracer-ratio method. Biomass burning contributed 9.5%-17.7% to mixing ratios of the nine VOCs. The estimated biomass burning contributions are compared with local emission inventories. Large discrepancies are observed between our results and the estimates in two emission inventories. Though biomass burning emissions in TRACE-P inventory agree well with our results, the VOCs speciation for aromatic compounds may be not appropriate for Guangdong. PMID:20507061

Yuan, Bin; Liu, Ying; Shao, Min; Lu, Sihua; Streets, David G

2010-06-15

158

A Coupled Airflow and Source/Sink Model for Simulating Indoor VOC and Q. Chen2  

E-print Network

02139, USA Abstract In this paper, a numerical model is presented to study the indoor air quality (IAQ; Indoor air quality; Emissions; Sorption; Ventilation; Modeling. Practical Implications Traditionally exposures" Indoor Air, 11(4), 257-269. #12;2 Introduction Indoor environment is important to workers' health

Chen, Qingyan "Yan"

159

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

SciTech Connect

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

NONE

1995-11-01

160

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

161

Classification of OH Radio Emission Sources.  

National Technical Information Service (NTIS)

Those OH emission sources which emit most strongly at 1665 or 1667 MHz seem to be associated with H II regions, whereas those OH emission sources which emit most strongly at 1720 or 1612 MHz seem to be associated with combinations of non-thermal radio sou...

J. A. Ball, D. H. Staelin

1968-01-01

162

Source Contributions to VOC's to Ozone Formation in Southeast Texas Using a Source-oriented Air Quality Model  

E-print Network

of approximately 28% to ozone formation. Wildfires contribute to as much 11% of ozone formation on days of high wildfire activity. The model results show that biogenic emissions account for a significant amount of ozone formation in the rural areas. Both highway...

Krishnan, Anupama

2011-08-08

163

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

PubMed

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

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

2011-01-01

164

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 ...

165

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...

166

Aerostat-lofted instrument and sampling method for determination of emissions from open area sources.  

PubMed

An aerostat-borne instrument and sampling method was developed to characterize air samples from area sources, such as emissions from open burning. The 10 kg battery-powered instrument system, termed "the Flyer", is lofted with a helium-filled aerostat of 4m nominal diameter and maneuvered by means of one or two tethers. The Flyer can be configured variously for continuous CO? monitoring, batch sampling of semi-volatile organic compounds (SVOCs), volatile organic compounds (VOCs), black carbon, metals, and PM by size. The samplers are controlled by a trigger circuit to avoid unnecessary dilution from background sampling when not within the source plume. The aerostat/Flyer method was demonstrated by sampling emissions from open burning (OB) and open detonation (OD) of military ordnance. A carbon balance approach was used to derive emission factors that showed excellent agreement with published values. PMID:21840564

Aurell, Johanna; Gullett, Brian K; Pressley, Christopher; Tabor, Dennis G; Gribble, Robert D

2011-10-01

167

Source apportionment of stack emissions from research and development facilities using positive matrix factorization  

NASA Astrophysics Data System (ADS)

Research and development (R&D) facility emissions are difficult to characterize due to their variable processes, changing nature of research, and large number of chemicals. Positive matrix factorization (PMF) was applied to volatile organic compound (VOC) 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 between 9 and 11 source-related factors contributing to stack emissions, depending on the building. Similar factors between buildings were major contributors to trichloroethylene (TCE), acetone, and ethanol emissions; other factors had similar profiles for two or more buildings but not all four. 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.

Ballinger, Marcel Y.; Larson, Timothy V.

2014-12-01

168

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

PubMed

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

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

2013-10-01

169

Characterization of emission sources into the indoor environment. Appendix volume to final report, March 1982-March 1985. Draft report  

SciTech Connect

The appendix to the final report on Characterization of Emission Sources in the Indoor Environment provides the experimental protocols for sampling and data analysis; emission rates of CO, NO, NO/sub 2/, and NOx from range-top burners as calculated from mass balance experiments; statistical charts and tables; calibration curves for CO, NOx, CO/sub 2/, SO/sub 2/, and hydrocarbons; quality-assurance procedures for monitoring of CO and oxides of nitrogen; and ion chromatograms for background and samples analyzed for VOC emission from range-top burners.

Moschandreas, D.J.; Relwani, S.; O'Neill, H.J.; Cole, J.T.; Elkins, R.H.

1985-03-01

170

INFLUENCE OF BIOGENIC EMISSIONS ESTIMATES ON OZONE PRECURSORCONTROL REQUIREMENTS FOR ATLANTA  

EPA Science Inventory

Emission estimates of volatile organic compounds (VOC) from naturalsources (biogenic emissions) are comparable to emissions fromanthropogenic sources in some regions of the U.S. esults from aprevious modeling study indicated that inclusion of biogenicemissions can substantially i...

171

Modeling VOC transport in simulated waste drums  

SciTech Connect

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

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

1993-06-01

172

60 FR 10654 - Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources...  

Federal Register 2010, 2011, 2012, 2013

...waste incineration cause the release of...largest known source of dioxin emissions...emissions from all sources is one of the...of sources that cause, or contribute...emissions (i.e., sources whose construction...requires these sources to control emissions...elements for the source category...

1995-02-27

173

Synchro-Compton emission from superluminal sources  

NASA Technical Reports Server (NTRS)

The application of synchro-Compton theory to real compact radio sources, the question of a self-Compton origin of the X-rays in radio-loud quasars and active galactic nuclei, and the phenomenology of superluminal motion are discussed in a review of research concerning synchro-Compton emission from superluminal sources. After examining the basic synchro-Compton theory of ideal sources, applications of the theory to real sources is discussed. It is concluded that the Compton problem and total energy requirements are not substantially mitigated by considering source structures more complicated than the multiple, uniform-component model used by most investigators. Also, alternatives to the standard model of superluminal motion are discussed, focusing on the assumptions usually made when interpreting superluminal sources.

Marscher, Alan P.

1987-01-01

174

Volatile organic compounds (VOCs) in soils  

Microsoft Academic Search

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

Heribert Insam; Martin S. A. Seewald

2010-01-01

175

Relationship between air exchange rate and indoor VOC levels  

SciTech Connect

It is often assumed that the air quality is better in leaky than in airtight buildings. To test this anecdotal hypothesis, data from two Canadian surveys were examined. Indoor measurements of 28 volatile organic compounds (VOCs) were made by means of a passive sampling method during the 24 to 48 h study periods in both studies, and air exchange rates were determined by the perfluorocarbon tracer approach. The air exchange rates ranged between about 0.1 to 2.5 air changes per hour in 54 test homes in the Greater Toronto Area (GTA). Other information on building age and construction, renovation activities and occupant activities that potentially influenced indoor VOC concentrations in the homes was collected by means of a questionnaire. The statistical relationships between the concentrations of VOCs and air exchange were determined. Correlation coefficients between the airborne concentrations of each VOC and the air exchange rates for the homes were all < 0.1 indicating that the relationship between the air exchange and indoor VOC concentrations is tenuous. Since the questionnaire responses did not provide quantitative estimates of indoor emissions, a quantitative correlation between responses and indoor concentrations could not be established nor was a consistent pattern evident between these responses and the occurrence of high indoor concentrations. The lack of definitive quantitative relationships is not surprising considering the complexity of indoor environments, the lack of a detailed inventory of indoor sources and their emission rates and a lack of information or understanding of indoor sinks. The findings, on the effect of air exchange rates and the value of questionnaires in studies on indoor VOCs are consistent with findings in other similar studies.

Otson, R.; Williams, D.T. [Health Canada, Ottawa, Ontario (Canada); Fellin, P. [Conor Pacific Environmental, Toronto, Ontario (Canada)

1998-12-31

176

40 CFR 63.843 - Emission limits for existing sources.  

Code of Federal Regulations, 2012 CFR

...Emission limits for existing sources. 63.843 Section 63...HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) ...Hazardous Air Pollutants for Primary Aluminum Reduction Plants...Emission limits for existing sources. (a) Potlines....

2012-07-01

177

40 CFR 63.843 - Emission limits for existing sources.  

Code of Federal Regulations, 2013 CFR

...Emission limits for existing sources. 63.843 Section 63...HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) ...Hazardous Air Pollutants for Primary Aluminum Reduction Plants...Emission limits for existing sources. (a) Potlines....

2013-07-01

178

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...

179

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

180

Evaluation of Low-VOC Latex Paints.  

National Technical Information Service (NTIS)

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

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

1999-01-01

181

Monochromatic Photo-Field Electron Emission Sources  

NASA Astrophysics Data System (ADS)

Laser-pulsed photo-field-emission sources with high coherence and brightness are needed for time-resolved electron microscopy. Our ongoing work explores the possibility of using sharpened semiconductor electron emitters to achieve this goal. Intrinsic GaAs field-emission sources have been prepared from cleaved needles that are clipped into refractory metal holders. These needles are chemically sharpened and surface cleaned by field-desorption and electron-bombardment heating. Field emission I-V curves have been analyzed, with and without laser illumination, which demonstrate a range of metallic and semiconductor characteristics. He-Ne laser illumination has been observed to increase field emission currents by more then an order of magnitude. The band structure of a semiconductor can be used to create a lower bound on the energy of photo-excited field-emitted electrons, producing a beam whose energy width is E=Eg-h? (bandgap Eg). Energy analysis is planned using a hemispherical analyzer, aimed at achieving an energy spread less than the 0.26 eV of conventional W tips. Calculations are underway to understand complications arising from surface effects and bulk transport. NNSA award DE-PS52-05NA funds this research.

Vecchione, Theodore; Hembree, Gary; Weierstall, Uwe; Spence, John; Browning, Nigel

2007-03-01

182

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

NASA Astrophysics Data System (ADS)

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

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

183

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...

184

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...

185

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...

186

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...

187

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

188

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

Federal Register 2010, 2011, 2012, 2013

...production major source category was based...would be major sources of HAPs. These...including antimony, arsenic, beryllium...recurrence of the cause of a deviation...Existing Affected Sources and Emission Units...operation/ Affected source/emission unit...All affected sources and emission...

1999-02-11

189

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

190

62 FR 45124 - Emission Guidelines for Existing Sources and Standards of Performance for New Stationary Sources...  

Federal Register 2010, 2011, 2012, 2013

...Part 60 Emission Guidelines for Existing Sources and Standards of Performance for New Stationary Sources: Large Municipal Waste Combustion Units...2016-AD04 Emission Guidelines for Existing Sources and Standards of Performance for New...

1997-08-25

191

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

192

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

193

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

NASA Astrophysics Data System (ADS)

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

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

2011-07-01

194

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

Code of Federal Regulations, 2013 CFR

... 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

195

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

NASA Astrophysics Data System (ADS)

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

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

2009-05-01

196

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

NASA Astrophysics Data System (ADS)

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

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

2009-01-01

197

Indoor air quality (IAQ) assessment in a multistorey shopping mall by high-spatial-resolution monitoring of volatile organic compounds (VOC).  

PubMed

In order to assess indoor air quality (IAQ), two 1-week monitoring campaigns of volatile organic compounds (VOC) were performed in different areas of a multistorey shopping mall. High-spatial-resolution monitoring was conducted at 32 indoor sites located in two storehouses and in different departments of a supermarket. At the same time, VOC concentrations were monitored in the mall and parking lot area as well as outdoors. VOC were sampled at 48-h periods using diffusive samplers suitable for thermal desorption. The samples were then analyzed with gas chromatography-mass spectrometry (GC-MS). The data analysis and chromatic maps indicated that the two storehouses had the highest VOC concentrations consisting principally of terpenes. These higher TVOC concentrations could be a result of the low efficiency of the air exchange and intake systems, as well as the large quantity of articles stored in these small spaces. Instead, inside the supermarket, the food department was the most critical area for VOC concentrations. To identify potential emission sources in this department, a continuous VOC analyzer was used. The findings indicated that the highest total VOC concentrations were present during cleaning activities and that these activities were carried out frequently in the food department. The study highlights the importance of conducting both high-spatial-resolution monitoring and high-temporal-resolution monitoring. The former was able to identify critical issues in environments with a complex emission scenario while the latter was useful in interpreting the dynamics of each emission source. PMID:24448884

Amodio, M; Dambruoso, P R; de Gennaro, Gianluigi; de Gennaro, L; Loiotile, A Demarinis; Marzocca, A; Stasi, F; Trizio, L; Tutino, M

2014-12-01

198

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

199

Supplement for "VOCs Emissions, Evolutions and Contributions to SOA1 Formation at a Receptor Site in Eastern China"2  

E-print Network

in Mexico City14 showed that ethyl acetate from industrial emissions can also fragment to m/z 61 channel and the average temperature was35 9.9±3.8 °C. Temperature was strongly depended on the large-scale weather system was conducted in the transit period between winter34 and spring. Temperature varied in the range of 0-20 °C

Meskhidze, Nicholas

200

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.

201

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

202

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

Microsoft Academic Search

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

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

2012-01-01

203

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

Microsoft Academic Search

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

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

2011-01-01

204

62 FR 48348 - Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources...  

Federal Register 2010, 2011, 2012, 2013

...for New Stationary Sources and Emission Guidelines for Existing Sources: Hospital/Medical...action promulgates new source performance standards...infectious waste. Sources are required to achieve...concentrations can cause toxic effects...

1997-09-15

205

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

206

Underestimated public health risks caused by overestimated VOC removal in wastewater treatment processes.  

PubMed

The uncontrolled release of volatile organic compounds (VOCs) from wastewater treatment plants (WWTPs) and the adverse health effects on the public have been of increasing concern. In this study, a lab-scale bioreactor was prepared to analyze the mass distribution of three aromatic (benzene, toluene, and xylenes) and four chlorinated VOCs (chloroform, carbon tetrachloride, trichloroethylene, and tetrachloroethylene) among the air, water and sludge phases in wastewater treatment processes. The VOC distribution through a full-scale WWTP in northern China was further investigated with respect to the effects of seasonal temperature variations and treatment technologies, followed by the cancer risk assessment using a steady-state Gaussian plume model (Industrial Source Complex) to simulate the atmospheric behaviors of the VOCs emitted from the WWTP. It was found that three aromatic hydrocarbons, notably benzene, were more readily released from the wastewater into the atmosphere, whereas the chlorinated compounds except chloroform were mainly present in the water phase through the treatment processes. The primary clarifier was the technology releasing high levels of VOCs into the atmosphere from the wastewater. The extents of volatilization or biodegradation, two important mechanisms to remove VOCs from wastewater, appeared to be determined by the physicochemical characteristics of the compounds, as the influence of treatment technologies (e.g., aeration) and seasonal temperature variations was rather limited. More importantly, the people living in the areas even more than 4 km away from the WWTP were still potentially exposed to cancer risks exceeding the regulatory threshold limit. The findings described the complex nature of VOC emissions from WWTPs and quantitatively indicated that the associated health impacts on the public near the WWTPs could be severely underestimated, whereas their treatment efficiencies by wastewater treatment technologies were overestimated. Instead of fully controlling the VOC release from WWTPs, the identification and abatement of important VOC species with regard to the atmospheric emission and health concerns is one possible alternative approach to effectively minimize the environmental and public health impacts by VOCs released from this particular source. PMID:24337048

Yang, Junchen; Wang, Kun; Zhao, Qingliang; Huang, Likun; Yuan, Chung-Shin; Chen, Wei-Hsiang; Yang, Wen-Bin

2014-02-01

207

40 CFR 63.1157 - Emission standards for existing sources.  

Code of Federal Regulations, 2010 CFR

...PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL...EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES...Emission Standards for Hazardous Air Pollutants for Steel Pickling-HCl...Facilities and Hydrochloric Acid Regeneration Plants § 63.1157...

2010-07-01

208

40 CFR 63.1157 - Emission standards for existing sources.  

Code of Federal Regulations, 2011 CFR

...PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL...EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES...Emission Standards for Hazardous Air Pollutants for Steel Pickling-HCl...Facilities and Hydrochloric Acid Regeneration Plants § 63.1157...

2011-07-01

209

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

210

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

PubMed

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

211

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

212

A Comparison of Screening and Refined Exposure Models for Evaluating Toluene Air Emissions from a Washing Machine  

Microsoft Academic Search

Residential clothes washing machines are potential air emission sources for volatile organic compounds (VOCs). The U.S. Environmental Protection Agency has a screening model to predict the potential inhalation exposure to VOC emissions from a washing machine into room air. They also have a refined exposure model that can be extrapolated to evaluate a washing machine. The objectives of this study

David McCready

2012-01-01

213

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 ...

214

Source Emissions in Multipollutant Air Quality Management  

Microsoft Academic Search

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

C. Andrew Miller

215

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...

216

Asbestos Emissions from Baghouse Controlled Sources  

Microsoft Academic Search

There is virtually no information published on the absolute efficiency of baghouses in reducing the emissions of fine particles of asbestos. This lack of information is unfortunate because serious occupational health problems may result from the common practice of recirculating air to conserve energy. Emission testing has been conducted at five asbestos processing plants where the emissions are controlled by

COLIN F. HARWOOD; DAVID K. OESTREICH; PAUL SIEBERT; JOHN D. STOCKHAM

1975-01-01

217

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...

218

Mobile source and livestock feed contributions to regional ozone formation in Central California.  

PubMed

A three-dimensional air quality model with 8 km horizontal resolution was applied to estimate the summertime ozone (O(3)) production from mobile sources and fermented livestock feed in California's San Joaquin Valley (SJV) during years 2000, 2005, 2010, 2015, and 2020. Previous studies have estimated that animal feed emissions of volatile organic compounds (VOCs) have greater O(3) formation potential than mobile-source VOC emissions when averaging across the entire SJV. The higher spatial resolution in the current study shows that the proximity of oxides of nitrogen (NO(x)) and VOC emissions from mobile sources enhances their O(3) formation potential. Livestock feed VOC emissions contributed 3-4 ppb of peak O(3) (8-h average) in Tulare County and 1-2 ppb throughout the remainder of the SJV during the CCOS 2000 July-August episode. In total, livestock feed contributed ~3.5 tons of the ground level peak O(3) (8 h average) in the SJV region, and mobile VOC contributed ~12 tons in this episode. O(3) production from mobile sources is declining over time in response to emissions control plans that call for cleaner fuels and engines with advanced emissions controls. Projecting forward to the year 2020, mobile-source VOC emissions are predicted to produce ~3 tons of the ground level peak O(3)(8-h average) and livestock feed VOC emissions are predicted to contribute ~2.5 tons making these sources nearly equivalent. PMID:22304388

Hu, Jianlin; Howard, Cody J; Mitloehner, Frank; Green, Peter G; Kleeman, Michael J

2012-03-01

219

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

220

Wavelength swept amplified spontaneous emission source.  

PubMed

We present a new, alternative approach to realize a wavelength swept light source with no fundamental limit to sweep speed. Amplified spontaneous emission (ASE) light alternately passes a cascade of optical gain elements and tunable optical bandpass filters. We show that for high sweep speeds, the control signal for the different filters has to be applied with a defined, precise phase delay on the order of nanoseconds, to compensate for the light propagation time between the filters and ensure optimum operation. At a center wavelength of 1300 nm sweep rates of 10 kHz, 100 kHz and 340 kHz over a sweep range of 100 nm full width and an average power of 50 mW are demonstrated. For application in optical coherence tomography (OCT), an axial resolution of 12 microm (air), a sensitivity of 120 dB (50 mW) and a dynamic range of 50 dB are achieved and OCT imaging is demonstrated. Performance parameters like coherence properties and relative intensity noise (RIN) are quantified, discussed and compared to the performance of Fourier Domain Mode Locked (FDML) lasers. Physical models for the observed difference in performance are provided. PMID:20372613

Eigenwillig, Christoph M; Biedermann, Benjamin R; Wieser, Wolfgang; Huber, Robert

2009-10-12

221

Silicon Nanoparticles: Source of Extended Red Emission?  

E-print Network

We have reviewed the characteristics of the extended red emission (ERE) as observed in many dusty astronomical environments, in particular, the diffuse interstellar medium of the Galaxy. The spectral nature and the photon conversion efficiency of the ERE identify the underlying process as highly efficient photoluminescence by an abundant component of interstellar dust. We have compared the photoluminescence properties of a variety of carbon- and silicon-based materials proposed as sources for the ERE with the observationally established constraints. We found that silicon nanoparticles provide the best match to the spectrum and the efficiency requirement of the ERE. If present in interstellar space with an abundance sufficient to explain the intensity of the ERE, silicon nanoparticles will also contribute to the interstellar 9.7 micron Si-O stretch feature in absorption, to the near- and mid-IR nonequilibrium thermal background radiation, and to the continuum extinction in the near- and far-UV. About 36% of the interstellar silicon depleted into the dust phase would be needed in the form of silicon nanoparticles, amounting to less than 5% of the interstellar dust mass. We propose that silicon nanoparticles form through the nucleation of SiO in oxygen-rich stellar mass outflows and that they represent an important small-grain component of the interstellar dust spectrum.

A. N. Witt; K. D. Gordon; D. G. Furton

1998-05-01

222

Proton emission from a laser ion source.  

PubMed

At intensities of the order of 10(10) W?cm(2), ns pulsed lasers can be employed to ablate solid bulk targets in order to produce high emission of ions at different charge state and kinetic energy. A special interest is devoted to the production of protons with controllable energy and current from a roto-translating target irradiated in repetition rate at 1-10 Hz by a Nd:Yag pulsed laser beam. Different hydrogenated targets based on polymers and hydrates were irradiated in high vacuum. Special nanostrucutres can be embedded in the polymers in order to modify the laser absorption properties and the amount of protons to be accelerated in the plasma. For example, carbon nanotubes may increase the laser absorption and the hydrogen absorption to generate high proton yields from the plasma. Metallic nanostrucutres may increase the electron density of the plasma and the kinetic energy of the accelerated protons. Ion collectors, ion energy analyzer, and mass spectrometers, used in time-of-flight configuration, were employed to characterize the ion beam properties. A comparison with traditional proton ion source is presented and discussed. PMID:22380289

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

2012-02-01

223

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

224

The QUISTOR as a pulsed-extraction source for time-of-flight mass spectrometry of VOCs in air  

SciTech Connect

Recently, the authors have been developing the ion trap/time-of-flight mass spectrometer (IT/TOF-MS) as a new instrument for real-time air analysis. The ion trap is an attractive pulsed-extraction source for TOF-MS because of its ion storage capability and its potential for high extraction efficiencies. In the IT/TOF-MS ion trap the entire ion cloud is extracted toward the exit endcap, as compared to 50% in an ion trap mass spectrometer. Moreover, the ion trap pulsed-extraction source can tolerate high background pressures and excessive space charge. The work presented here focuses on the development of the ion trap to improve the overall performance of the IT/TOF-MS used for air monitoring. A number studies have been performed to determine the best conditions for extraction of the ion cloud with the proper spatial and velocity distributions for focusing in the TOF-MS. Results from these investigations have led to improvements in ion trap operation. Detection limits are generally in the low to sub-ppb (V/V) range for analysis between times 10 and 100 ms. Resolution exceeds 2000 m/{Delta}m at FWHM. Mass accuracy is routinely 0.05% and scan-to-scan variations are less than 5%.

Chambers, D.M.; Thomas, S.W.; Grace, L.I.; Andresen, B.D. [Lawrence Livermore National Lab., CA (United States)

1995-12-31

225

Biogenic volatile emissions from the soil.  

PubMed

Volatile compounds are usually associated with an appearance/presence in the atmosphere. Recent advances, however, indicated that the soil is a huge reservoir and source of biogenic volatile organic compounds (bVOCs), which are formed from decomposing litter and dead organic material or are synthesized by underground living organism or organs and tissues of plants. This review summarizes the scarce available data on the exchange of VOCs between soil and atmosphere and the features of the soil and particle structure allowing diffusion of volatiles in the soil, which is the prerequisite for biological VOC-based interactions. In fact, soil may function either as a sink or as a source of bVOCs. Soil VOC emissions to the atmosphere are often 1-2 (0-3) orders of magnitude lower than those from aboveground vegetation. Microorganisms and the plant root system are the major sources for bVOCs. The current methodology to detect belowground volatiles is described as well as the metabolic capabilities resulting in the wealth of microbial and root VOC emissions. Furthermore, VOC profiles are discussed as non-destructive fingerprints for the detection of organisms. In the last chapter, belowground volatile-based bi- and multi-trophic interactions between microorganisms, plants and invertebrates in the soil are discussed. PMID:24689847

Peñuelas, J; Asensio, D; Tholl, D; Wenke, K; Rosenkranz, M; Piechulla, B; Schnitzler, J P

2014-08-01

226

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

227

2-.mu.m Fiber Amplified Spontaneous Emission (ASE) Source.  

National Technical Information Service (NTIS)

A 2-(mu)m fiber Amplified Spontaneous Emission (ASE) source provides a wide emission bandwidth and improved spectral stability/purity for a given output power. The fiber ASE source is formed from a heavy metal oxide multicomponent glass selected from germ...

J. Geng, J. Wu S. Jiang

2007-01-01

228

REGIONAL AIR POLLUTION STUDY. POINT SOURCE EMISSION INVENTORY  

EPA Science Inventory

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

229

Dry Sources of Plume Emissions on Enceladus  

NASA Astrophysics Data System (ADS)

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

Zolotov, M. Y.

2009-12-01

230

Registration for the Hanford Site: Sources of radioactive emissions  

SciTech Connect

This Registration Application serves to renew the registration for all Hanford Site sources of radioactive air emissions routinely reported to the State of Washington Department of Health (DOH). The current registration expires on August 15, 1993. The Application is submitted pursuant to the Washington Administrative Code (WAC) Chapter 246--247, and is consistent with guidance provided by DOH for renewal. The Application subdivides the Hanford Site into six major production, processing or research areas. Those six areas are in the 100 Area, 200 East Area, 200 West Area, 300 Area, 400 Area, and 600 Area. Each major group of point sources within the six areas listed above is represented by a Source Registration for Radioactive Air Emissions form. Annual emissions. for the sources are listed in the ``Radionuclide Air Emissions Report for the Hanford Site,`` published annually. It is a requirement that the following Statement of Compliance be provided: ``The radioactive air emissions from the above sources do meet the emissions standards contained in Chapter 173-480-040 WAC, Ambient Air Quality Standards and Emissions Limits for Radionuclides. As the Statement of Compliance pertains to this submittal, the phrase ``above sources`` is to be understood as meaning the combined air emissions from all sources registered by this submittal.

Silvia, M.J.

1993-04-01

231

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

232

Extended emission sources observed via two-proton correlations  

SciTech Connect

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

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

1989-01-01

233

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

PubMed

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

Chin, Jo-Yu; Batterman, Stuart A

2012-03-01

234

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

Federal Register 2010, 2011, 2012, 2013

...lists HAP believed to cause adverse health or environmental...each standard for major sources must require the maximum...ensure that all major sources of air toxic emissions...controlled and lower emitting sources in each category. This...citizens that each major source of toxic air...

1997-09-18

235

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

Federal Register 2010, 2011, 2012, 2013

...each standard for major sources require the maximum...ensure that all major sources of air toxic emissions...controlled and lower emitting sources in each category. This...citizens that each major source of toxic air pollution...largest quantities are arsenic and lead compounds...These toxic metals can cause effects such as...

1998-04-20

236

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

237

User access to the MAP3S source emissions inventory  

SciTech Connect

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

Benkovitz, C M; Evans, V A

1981-03-01

238

[Study on volatile organic compounds emission of straw combustion and management countermeasure in Wuhan city].  

PubMed

Straw combustion is an important anthropogenic source of volatile organic compounds (VOCs) in China. Emissions of VOCs from straw combustion significantly affect climate forcing and human health. A reliable estimation of VOCs emission from the source is the important prerequisite for emission impact assessment and control strategy in the urban or regional areas. VOCs emissions from straw combustion in Wuhan City and the districts were estimated by factor analysis method, which was based on the yield of major farm crops in the period of 2005-2011. Moreover, Cultivated-land Emission Intensity (Ie) and Regional Emission Intensity (Ir) were also calculated. VOCs Emissions from straw combustion in Wuhan City were (3,163 +/- 139) t in the period of 2005-2011; Ie and Ir was (1.52 +/- 0.06) t x km(-2) and (0.37 +/- 0.02) t x km(-2), respectively; Straw combustion of grain and oilseed crops was the main source of the emissions; 21 kinds of VOCs should be listed as the priority control pollutants for straw combustion in Wuhan City. The order of successively decreasing VOCs emission of districts in Wuhan City was Huangpi District, Xinzhou District, Jiangxia District, Caidian District, Hannan District, and Dongxihu District, the former 4 districts contributed to almost 90% VOCs emissions of the Wuhan City. Huangpi District, Xinzhou District, Jiangxia District, and Hannan District should be regarded as priority control areas of VOCs emission from straw combustion in Wuhan City. Much attention should be paid to Jiangxia District, which was nationally representative. Ie and Ir are important basic data for ecological risk assessment of some kind of pollutants emitted from straw combustion in the urban or regional areas. Furthermore, straw utilization model according to agricultural cyclic economy is a feasible way to cope with the environmental problem of straw combustion. PMID:24640888

Huang, Bi-Jie

2013-12-01

239

Assessment of control strategies for reducing volatile organic compound emissions from the polyvinyl chloride wallpaper production industry in Taiwan.  

PubMed

This study attempts to assess the effectiveness of control strategies for reducing volatile organic compound (VOC) emission from the polyvinyl chloride (PVC) wallpaper production industry. In Taiwan, methyl ethyl ketone, TOL, and cyclohexanone have comprised the major content of solvents, accounting for approximately 113,000 t/yr to avoid excessive viscosity of plasticizer dioctyl phthalate (DOP) and to increase facility in working. Emissions of these VOCs from solvents have caused serious odor and worse air quality problems. In this study, 80 stacks in five factories were tested to evaluate emission characteristics at each VOC source. After examining the VOC concentrations in the flue gases and contents, the VOC emission rate before treatment and from fugitive sources was 93,000 and 800 t/yr, respectively. In this study, the semiwet electrostatic precipitator is recommended for use as cost-effective control equipment. PMID:16739797

Chang, Chang-Tang; Chiou, Chyow-Shan

2006-05-01

240

Possible nightside source dominance in nonthermal radio emissions from Uranus  

NASA Technical Reports Server (NTRS)

Desch and Kaiser (1984) have formulated a radiometric Bode's law from which they have attempted to estimate the low frequency, nonthermal radio power of the magnetosphere of Uranus. It is shown here that, if Uranus possesses a magnetosphere, it is more likely that the radio emission is from the nightside as opposed to the dayside as assumed by Desch and Kaiser. A nightside source for the radio emissions would radically alter the predicted time for direct observations of the emissions.

Curtis, S. A.

1985-01-01

241

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...

242

METHOD FOR MEASURING CARBON FIBER EMISSIONS FROM STATIONARY SOURCES  

EPA Science Inventory

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

243

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...

244

EFFECTIVE SAMPLING TECHNIQUES FOR PARTICULATE EMISSIONS FROM ATYPICAL STATIONARY SOURCES  

EPA Science Inventory

Sampling techniques for measuring particulate emissions from four 'atypical' stationary source categories were developed and evaluated. The categories include low effluent velocity streams, extended dimensions, partially or totally unconfined flow, and saturated gas streams or ga...

245

40 CFR 63.1157 - Emission standards for existing sources.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

246

40 CFR 63.1157 - Emission standards for existing sources.  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

247

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 ...

248

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.

249

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

250

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...

251

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...

252

[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

253

Asbestos emissions from baghouse controlled sources.  

PubMed

There is virtually no information published on the absolute efficiency of baghouses in reducing the emmisions of fine particles of asbestos. This lack of information is unfortunate because serious occupational health problems may result from the common practice of recirculating air to conserve energy. Emission testing has been conducted at five asbestos processing plants where the emissions are controlled by baghouses. The results showed that the mass removal efficiency frequently exceeded 99.00%. Membrane filter samples of the effluent were examined by optical and electron microscope. It was observed that despite the high mass efficiency, the number of fibers emitted, which were greater than 1.5 mum in length, was about 10(4)-10(5) fibers/m3, while the number of fibers less than 1.5 mum was 10(7)-10(8) fibers/m3. The significance of the size of the fibers in terms of probably health impact is briefly discussed. PMID:1227285

Harwood, C F; Oestreich, D K; Siebert, P; Stockham, J D

1975-08-01

254

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.

255

Reduction of volatile organic compound emissions from automobile refinishing  

SciTech Connect

Automobile refinishing (repainting) is a source of volatile organic compound (VOC) emissions. The study was conducted to evaluate available techniques that can be used to reduce VOC emissions from this source. The document provides information on the steps involved in the refinishing process which result in emissions, available emission reduction techniques, VOC emission levels, VOC emission reductions, and costs associated with the reduction techniques. Techniques investigated include (1) reduced-VOC cleaners, (2) replacement of lacquers with enamels, (3) replacement of enamels with polyurethanes, (4) replacement of solvent-borne primers with waterborne primers, (5) replacement of conventional clearcoats with higher-solids clearcoats, (6) installation of cleanup solvent recovery systems, (7) replacement of conventional spray guns with higher transfer efficiency equipment, and (8) add-on controls. The primary conclusions from the study are: (1) the use of available techniques could result in VOC emission reductions ranging from 3-50% of the current estimated baseline emissions from typical refinishing shops; and (2) the annualized costs for many of the available techniques are less than the cost of current practices.

Athey, C.; Hester, C.; McLaughlin, M.; Neulicht, R.M.; Turner, M.B.

1988-10-01

256

Methane Emissions from Point and Area Sources in California  

NASA Astrophysics Data System (ADS)

Airborne measurements of methane (CH4), carbon monoxide (CO), sulfur dioxide, ammonia, and nitric oxides were made aboard the NOAA WP-3D during May and June 2010, during the CalNex (Research at the Nexus of Air Quality and Climate Change) field campaign based out of Ontario, California. Emission ratios of CH4 to these other trace gas species are calculated from observations downwind of point sources and compared to national emissions inventories. Further, background urban ratios of CH4 to CO are established, and enhancements from known area CH4 sources, such as rice paddies and cattle ranches, are analyzed. Finally, significant methane emissions from point sources not in emissions inventories are examined.

Peischl, J.; Ryerson, T. B.; Frost, G. J.; Holloway, J. S.; McKeen, S. A.; Neuman, J.; Nowak, J. B.; Pollack, I. B.; Roberts, J. M.; Trainer, M.; Parrish, D. D.

2010-12-01

257

Source profiles of volatile organic compounds associated with solvent use in Beijing, China  

NASA Astrophysics Data System (ADS)

Compositions of volatile organic compound (VOC) emissions from painting applications and printing processes were sampled and measured by gas chromatography-mass spectrometry/flame ionization detection (GC-MS/FID) in Beijing. Toluene and C8 aromatics were the most abundant species, accounting for 76% of the total VOCs emitted from paint applications. The major species in printing emissions included heavier alkanes and aromatics, such as n-nonane, n-decane, n-undecane, toluene, and m/p-xylene. Measurements of VOCs obtained from furniture paint emissions in 2003 and 2007 suggest a quick decline in benzene levels associated with formulation changes in furniture paints during these years. A comparison of VOC source profiles for painting and printing between Beijing and other parts of the world showed significant region-specific discrepancies, probably because of different market demands and environmental standards. We conducted the evaluation of the source reactivities for various VOC emission sources. The ozone formation potential (OFP) for unit mass of VOCs source emissions is the highest for paint applications. Substituting solvent-based paints by water-based in Beijing will lead to an OFP reduction of 152,000 tons per year, which is more than 1/4 of the OFPs for VOCs emissions from vehicle exhaust in the city.

Yuan, Bin; Shao, Min; Lu, Sihua; Wang, Bin

2010-05-01

258

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, ...

259

Source- and Age-Resolved Mechanistic Air Quality Models: Model Development and Application in Southeast Texas  

E-print Network

compounds (VOCs) and nitrogen oxides (NOx). Quantitative knowledge of the contributions of different emissions sources to O3 and PM is helpful to better understand their formation mechanisms and develop effective control strategies. Tagged reactive tracer...

Zhang, Hongliang

2012-07-16

260

Noise source emissions, Davis Canyon site, Utah  

SciTech Connect

This report has been prepared for the purpose of documenting the development of the data provided to the Repository Project Management (RPM) organization. The data provided encompass all phases of activity, from site preparation through the exploratory shaft facility (ESF) and repository construction and operation, and decommissioning. Noise environments expected from construction and operation of transportation corridors associated with the activity were also modeled. The data for the construction of transportation corridors were provided by Bechtel National, Inc. Use of the quietest equipment available within the proven state of the art was assumed, as was the use of acoustical enclosures to the extent practical. The programmatic assumptions are based on the noise-sensitive nature of the Canyonlands National Park. Another feature of the data is the use of 1/3-octave-band rather than 1/1-octave-band resolution of emission spectra. This was done to permit evaluation of audibility of sounds reaching the park.

Not Available

1987-07-01

261

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

262

40 CFR Table 1 to Subpart B of... - Volatile Organic Compound (VOC) Content Limits for Automobile Refinish Coatings  

Code of Federal Regulations, 2013 CFR

...Organic Compound (VOC) Content Limits for Automobile Refinish Coatings 1 Table 1 to Subpart...Organic Compound Emission Standards for Automobile Refinish Coatings Pt. 59, Subpt...Organic Compound (VOC) Content Limits for Automobile Refinish Coatings Coating...

2013-07-01

263

40 CFR Table 1 to Subpart B of... - Volatile Organic Compound (VOC) Content Limits for Automobile Refinish Coatings  

Code of Federal Regulations, 2010 CFR

...Organic Compound (VOC) Content Limits for Automobile Refinish Coatings 1 Table 1 to Subpart...Organic Compound Emission Standards for Automobile Refinish Coatings Pt. 59, Subpt...Organic Compound (VOC) Content Limits for Automobile Refinish Coatings Coating...

2010-07-01

264

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

265

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.

266

VOCs and IVOCs in the Los Angeles Basin: Quantification and Correlation to Regional Demographics  

NASA Astrophysics Data System (ADS)

Volatile organic compounds (VOCs) and intermediate volatility VOCs (IVOCs) are hydrocarbons that participate in chemical reactions affecting air quality and climate. VOCs and IVOCs, classified separately due to differences in effective saturation constants, both contribute to ozone and aerosol formation. IVOCs are not typically measured in ambient VOC studies because they are easily lost to sampling surfaces. Additionally, many VOCs and IVOCs, particularly aromatic hydrocarbons, are of concern because they have high respiratory uptake and accumulate in adipose tissue. The purpose of this study is to quantify VOCs and IVOCs in residential neighborhoods around the Los Angeles basin using a portable and inexpensive analytical method and to overlay these data with regional demographics. Hayesep-Q adsorbent cartridges were used to sample ambient air, followed by solvent extraction and analysis by Gas Chromatography and Mass Spectrometry (GC-MS). Data will be presented from a pilot study consisting of measurements made at 7 sites over 3 weeks in summer 2013. Results suggest a correlation between higher mixing ratios of anthropogenic compounds and low income status. For example, 92% of the variation in 1,2,3-trimethylbenzene concentrations can be explained by the linear relationship between these mixing ratios and the percentage of household income less than $20,000 in each neighborhood (R2 = 0.917). Communities most at risk from the emission of these compounds will likely be located near sources (i.e. roadways, freeways, flight paths) and thus are typically low-income and not a part of the California Air Resources Board monitoring system.

Carrasco, E.; Bouvier-Brown, N. C.

2013-12-01

267

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

268

Distribution of airborne particles from multi-emission source.  

PubMed

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

Kemppainen, Sari; Tervahattu, Heikki; Kikuchi, Ryunosuke

2003-06-01

269

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

270

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

271

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

272

2-.mu.m fiber amplified spontaneous emission (ASE) source  

NASA Technical Reports Server (NTRS)

A 2-.mu.m fiber Amplified Spontaneous Emission (ASE) source provides a wide emission bandwidth and improved spectral stability/purity for a given output power. The fiber ASE source is formed from a heavy metal oxide multicomponent glass selected from germanate, tellurite and bismuth oxides and doped with high concentrations, 0.5-15 wt. %, thulium oxides (Tm.sub.2O.sub.3) or 0.1-5 wt% holmium oxides (Ho.sub.2O.sub.3) or mixtures thereof. The high concentration of thulium dopants provide highly efficient pump absorption and high quantum efficiency. Co-doping of Tm and Ho can broaden the ASE spectrum.

Jiang, Shibin (Inventor); Wu, Jianfeng (Inventor); Geng, Jihong (Inventor)

2007-01-01

273

CO2 EMISSIONS FROM BIOENERGY AND OTHER BIOGENIC SOURCES IN STATIONARY SOURCES  

EPA Science Inventory

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

274

73 FR 1916 - National Emission Standards for Hazardous Air Pollutants for Source Categories: Gasoline...  

Federal Register 2010, 2011, 2012, 2013

...control requirements on sources within the source category that met the definition...regulated under the Major Source NESHAP. Area sources of HAP emissions within...standards for the major sources in each source category. Once we...

2008-01-10

275

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

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

276

DETECTING SMALL LOW EMISSION RADIATING SOURCES Moritz Allmaras  

E-print Network

security. A technique of detecting such sources using Compton type cameras is developed, which is shown of the Department of Homeland Security is to prevent smuggling of weapon-grade nuclear materials (e.g., [24 particles. For instance, the -cameras most commonly used in SPECT (Single Photon Emission Computed

277

FEASIBILITY OF DEVELOPING SOURCE SAMPLING METHODS FOR ASBESTOS EMISSIONS  

EPA Science Inventory

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

278

MEASURING INORGANIC AND ALKYL LEAD EMISSIONS FROM STATIONARY SOURCES  

EPA Science Inventory

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

279

COMPARATIVE STUDY OF OPEN SOURCE PARTICULATE EMISSION MEASURING TECHNIQUES  

EPA Science Inventory

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

280

REVIEW OF INDOOR EMISSION SOURCE MODELS: PART 2. PARAMETER ESTIMATION  

EPA Science Inventory

This review consists of two sections. Part I provides an overview of 46 indoor emission source models. Part 2 (this paper) focuses on parameter estimation, a topic that is critical to modelers but has never been systematically discussed. A perfectly valid model may not be a usefu...

281

PCB EMISSIONS FROM STATIONARY SOURCES: A THEORETICAL STUDY  

EPA Science Inventory

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

282

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

NASA Astrophysics Data System (ADS)

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

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

2012-09-01

283

Source Characterization of Volatile Organic Compounds Affecting the Air Quality in a Coastal Urban Area of South Texas  

PubMed Central

Selected Volatile Organic Compounds (VOC) emitted from various anthropogenic sources including industries and motor vehicles act as primary precursors of ozone, while some VOC are classified as air toxic compounds. Significantly large VOC emission sources impact the air quality in Corpus Christi, Texas. This urban area is located in a semi-arid region of South Texas and is home to several large petrochemical refineries and industrial facilities along a busy ship-channel. The Texas Commission on Environmental Quality has setup two continuous ambient monitoring stations (CAMS 633 and 634) along the ship channel to monitor VOC concentrations in the urban atmosphere. The hourly concentrations of 46 VOC compounds were acquired from TCEQ for a comprehensive source apportionment study. The primary objective of this study was to identify and quantify the sources affecting the ambient air quality within this urban airshed. Principal Component Analysis/Absolute Principal Component Scores (PCA/APCS) was applied to the dataset. PCA identified five possible sources accounting for 69% of the total variance affecting the VOC levels measured at CAMS 633 and six possible sources affecting CAMS 634 accounting for 75% of the total variance. APCS identified natural gas emissions to be the major source contributor at CAMS 633 and it accounted for 70% of the measured VOC concentrations. The other major sources identified at CAMS 633 included flare emissions (12%), fugitive gasoline emissions (9%), refinery operations (7%), and vehicle exhaust (2%). At CAMS 634, natural gas sources were identified as the major source category contributing to 31% of the observed VOC. The other sources affecting this site included: refinery operations (24%), flare emissions (22%), secondary industrial processes (12%), fugitive gasoline emissions (8%) and vehicle exhaust (3%). PMID:19139530

Sanchez, Marciano; Karnae, Saritha; John, Kuruvilla

2008-01-01

284

Emissions from laboratory combustion of wildland fuels: emission factors and source profiles.  

PubMed

Combustion of wildland fuels represents a major source of particulate matter (PM) and light-absorbing elemental carbon (EC) on a national and global scale, but the emission factors and source profiles have not been well characterized with respect to different fuels and combustion phases. These uncertainties limit the accuracy of current emission inventories, smoke forecasts, and source apportionments. This study investigates the evolution of gaseous and particulate emission and combustion efficiency by burning wildland fuels in a laboratory combustion facility. Emission factors for carbon dioxide (CO2), carbon monoxide (CO), total hydrocarbon (THC), nitrogen oxides (NO(x)), PM, light extinction and absorption cross sections, and spectral scattering cross sections specific to flaming and smoldering phases are reported. Emission factors are generally reproducible within +/- 20% during the flaming phase, which, despite its short duration, dominates the carbon emission (mostly in the form of CO2) and the production of light absorption and EC. Higher and more variable emission factors for CO, THC, and PM are found during the smoldering phase, especially for fuels containing substantial moisture. Organic carbon (OC) and EC mass account for a majority (i.e., > 60%) of PM mass; other important elements include potassium, chlorine, and sulfur. Thermal analysis separates the EC into subfractions based on analysis temperature demonstrating that high-temperature EC (EC2; at 700 degrees C) varies from 1% to 70% of PM among biomass burns, compared to 75% in kerosene soot. Despite this, the conversion factor between EC and light absorption emissions is rather consistent across fuels and burns, ranging from 7.8 to 9.6 m2/g EC. Findings from this study should be considered in the development of PM and EC emission inventories for visibility and radiative forcing assessments. PMID:17626431

Chen, L W Antony; Moosmüller, Hans; Arnott, W Patrick; Chow, Judith C; Watson, John G; Susott, Ronald A; Babbitt, Ronald E; Wold, Cyle E; Lincoln, Emily N; Hao, Wei Min

2007-06-15

285

ProVoc  

NSDL National Science Digital Library

Learning a new language can be daunting, but this handy application can make this process a bit friendlier. With ProVoc, users can download existing vocabulary sets for English, French, German, Italian, Spanish, Danish, and dozens of other languages. After that, they can run through these words at their leisure on their computer or their iPod for convenience. Finally, the site also includes a FAQ section that answers any number of topical questions about the application. This version is compatible with computers running Mac OS X 10.3 and newer.

2007-01-01

286

Accurate Simulation of Acoustic Emission Sources in Composite Plates  

NASA Technical Reports Server (NTRS)

Acoustic emission (AE) signals propagate as the extensional and flexural plate modes in thin composite plates and plate-like geometries such as shells, pipes, and tubes. The relative amplitude of the two modes depends on the directionality of the source motion. For source motions with large out-of-plane components such as delaminations or particle impact, the flexural or bending plate mode dominates the AE signal with only a small extensional mode detected. A signal from such a source is well simulated with the standard pencil lead break (Hsu-Neilsen source) on the surface of the plate. For other sources such as matrix cracking or fiber breakage in which the source motion is primarily in-plane, the resulting AE signal has a large extensional mode component with little or no flexural mode observed. Signals from these type sources can also be simulated with pencil lead breaks. However, the lead must be fractured on the edge of the plate to generate an in-plane source motion rather than on the surface of the plate. In many applications such as testing of pressure vessels and piping or aircraft structures, a free edge is either not available or not in a desired location for simulation of in-plane type sources. In this research, a method was developed which allows the simulation of AE signals with a predominant extensional mode component in composite plates requiring access to only the surface of the plate.

Prosser, W. H.; Gorman, M. R.

1994-01-01

287

Low VOC drying of lumber and wood panel products. Progress report No. 5  

SciTech Connect

This progress report summarizes three accomplishments in a study of low volatile organic compound (VOC) drying of lumber and wood panel products. A mathematical model for predicting moisture emissions from particle was constructed and is being extended to VOCs. VOCs emissions from drying boards show that VOCs appear to be evenly released from all surfaces. Preliminary results from monthly analyses of loblolly pines indicate that resin acids appear to decrease between March to August, and that no consistent trends are apparent for terpenes. 3 refs., 13 figs., 1 tab.

Wild, P.; Yan, Hui; Banerjee, S. [and others

1997-10-01

288

Gap-filling strategies for annual VOC flux data sets  

PubMed Central

Up to now the limited knowledge about the exchange of volatile organic compounds (VOCs) between the biosphere and the atmosphere is one of the factors which hinders more accurate climate predictions. Complete long-term flux data sets of several VOCs to quantify the annual exchange and validate recent VOC models are basically not available. In combination with long-term VOC flux measurements the application of gap-filling routines is inevitable in order to replace missing data and make an important step towards a better understanding of the VOC ecosystem-atmosphere exchange on longer time scales. We performed VOC flux measurements above a mountain meadow in Austria during two complete growing seasons (from snowmelt in spring to snow reestablishment in late autumn) and used this data set to test the performance of four different gap-filling routines, mean diurnal variation (MDV), mean gliding window (MGW), look up tables (LUT) and linear interpolation (LIP), in terms of their ability to replace missing flux data in order to obtain reliable VOC sums. According to our findings the MDV routine was outstanding with regard to the minimization of the gap-filling error for both years and all quantified VOCs. The other gap-filling routines, which performed gap-filling on 24 h average values, introduced considerably larger uncertainties. The error which was introduced by the application of the different filling routines increased linearly with the number of data gaps. Although average VOC fluxes measured during the winter period (complete snow coverage) were close to zero, these were highly variable and the filling of the winter period resulted in considerably higher uncertainties compared to the application of gap-filling during the measurement period. The annual patterns of the overall cumulative fluxes for the quantified VOCs showed a completely different behavior in 2009, which was an exceptional year due to the occurrence of a severe hailstorm, compared to 2011. Methanol was the compound which contributed with 381.5 mgCm?2 and 449.9 mgCm?2 most to the cumulative VOC carbon emissions in 2009 and 2011, respectively. In contrast to methanol emissions, however, considerable amounts of monoterpenes (?327.3 mgCm?2) were deposited to the mountain meadow in consequence to the hailstorm in 2009. Other quantified VOCs had considerably lower influences on the annual patterns. PMID:24363783

Bamberger, I.; Hörtnagl, L.; Walser, M.; Hansel, A.; Wohlfahrt, G.

2013-01-01

289

Acoustic emission source mechanisms for steel bridge material  

NASA Astrophysics Data System (ADS)

Over the past twenty years acoustic emission (AE) has been studied for applications to the structural health monitoring (SHM) of metallic structures. The success of AE for prognosis of in-service steel bridges depends on the reliability of the received AE signals. The emphasis of this paper is on the characterization of acoustic emission source mechanisms for ASTM A572 grade 50 steel. The source characterization was aided by Digital Imaging Correlation (DIC) and Scanning Electronic Microscopy (SEM). The results indicate that both ductile and brittle mechanisms can produce AE during fatigue crack growth in the steel. However, the fracture mechanisms are predominately ductile. A key preliminary finding is that fatigue crack extension does not generally produce AE events in the early stage of fatigue crack growth for the steel bridge material investigated.

Hossain, M.; Yu, J.; Ziehl, P.; Caicedo, J.; Matta, F.; Guo, S.; Sutton, M.

2013-01-01

290

The value of emissions from a single source (Invited)  

NASA Astrophysics Data System (ADS)

Forcing by aerosols and traditional air pollutants is short-lived, occuring within the first year after emission. This forcing can be up to half the magnitude of the forcing by long-lived species integrated over 100 years after emission. There is presently no way to value the immediacy and spatial distribution of the response to short-lived climate forcers. Searches for equivalence have been based on metrics such as the Global Temperature Potential that do not fully capture these features of the response. Discussions about reducing short-lived climate forcers are in full swing, with upcoming initiatives sponsored by the Clean Air and Climate Coalition. These proposals have been supported by global modeling results that show pronounced temperature decreases resulting from such initiatives. Each such model result is a single realization of our understanding of the complex Earth system response to a group of spatially and technologically diverse mitigation measures. In this presentation, we propose a framework that reflects the near-term and long-term nature of climate impact for emissions from a single source. Uncertainty in both response and emission characteristics are represented in this structure. The framework is then used to depict the potential value of changes in small residential and industrial sources, such as brick kilns, cooking stoves, heating stoves, and kerosene lamps.

Bond, T. C.; Chen, Y.

2013-12-01

291

UV emissions from low energy artificial light sources.  

PubMed

Energy efficient light sources have been introduced across Europe and many other countries world wide. The most common of these is the Compact Fluorescent Lamp (CFL), which has been shown to emit ultraviolet (UV) radiation. Light Emitting Diodes (LEDs) are an alternative technology that has minimal UV emissions. This brief review summarises the different energy efficient light sources available on the market and compares the UV levels and the subsequent effects on the skin of normal individuals and those who suffer from photodermatoses. PMID:24313558

Fenton, Leona; Moseley, Harry

2014-01-01

292

Fundamental mass transfer modeling of emission of volatile organic compounds from building materials  

NASA Astrophysics Data System (ADS)

In this study, a mass transfer theory based model is presented for characterizing the VOC emissions from building materials. A 3-D diffusion model is developed to describe the emissions of volatile organic compounds (VOCs) from individual sources. Then the formulation is extended to include the emissions from composite sources (system comprising an assemblage of individual sources). The key parameters for the model (The diffusion coefficient of the VOC in the source material D, and the equilibrium partition coefficient k e) were determined independently (model parameters are determined without the use of chamber emission data). This procedure eliminated to a large extent the need for emission testing using environmental chambers, which is costly, time consuming, and may be subject to confounding sink effects. An experimental method is developed and implemented to measure directly the internal diffusion (D) and partition coefficients ( ke). The use of the method is illustrated for three types of VOC's: (i) Aliphatic Hydrocarbons, (ii) Aromatic Hydrocarbons and ( iii) Aldehydes, through typical dry building materials (carpet, plywood, particleboard, vinyl floor tile, gypsum board, sub-floor tile and OSB). Then correlations for predicting D and ke based solely on commonly available properties such as molecular weight and vapour pressure were proposed for each product and type of VOC. These correlations can be used to estimate the D and ke when direct measurement data are not available, and thus facilitate the prediction of VOC emissions from the building materials using mass transfer theory. The VOC emissions from a sub-floor material (made of the recycled automobile tires), and a particleboard are measured and predicted. Finally, a mathematical model to predict the diffusion coefficient through complex sources (floor adhesive) as a function of time was developed. Then this model (for diffusion coefficient in complex sources) was used to predict the emission rate from material system (namely, substrate//glue//vinyl tile).

Bodalal, Awad Saad

293

Uranian H Ly-alpha emission - The interstellar wind source  

NASA Technical Reports Server (NTRS)

IUE observation of Uranian emissions in hydrogen Lyman alpha (H Ly-alpha) over the past four years have recently been summarized by Clarke et al. (1985). Over this time period they find an average H Ly-alpha brightness of 1260 R which they estimate is composed of 200 R of solar scattered radiation and 1060 R from a collisional source. A third component, not considered by previous authors, is the reflection of H Ly-alpha emissions from the interstellar wind. Hydrogen in the interstellar wind forms an extended source of H Ly-alpha whose importance relative to the solar flux increases with distance from the sun. The present paper demonstrates that scattering of interstellar H Ly-alpha is more important than scattering of solar H Ly-alpha for reasonable values of H column abundance and, in fact, may make up 10-40 percent of the observed signal. Large H column abundances are still required to explain the H Ly-alpha brightness solely on the basis of resonant scattering; therefore it is likely that the emissions are due in part to collisional sources and in part to the scattering of interstellar H Ly-alpha with solar scattering playing a minor role.

Yelle, R. V.; Sandel, B. R.

1986-01-01

294

Mitigation strategies for methane emissions from agricultural sources  

SciTech Connect

Anthropogenic emissions of CH{sub 4} account for 70% of total global emissions of this greenhouse gas. Current anthropogenic emissions of CH{sub 4} in the US are estimated to be between 24-30 Tg CH{sub 4} or 7-9% of the global anthropogenic total. By comparison the US is responsible for 27% of anthropogenic emissions of CO{sub 2} from fossil fuel use. Table 1 shows that the major anthropogenic sources of CH{sub 4} in the US are landfills (37%), domestic livestock and livestock waste (31%) and the coal mining/natural gas/petroleum industries (28%). On a global basis it is estimated that US landfills contribute 30% to the global landfill total, whereas livestock (including waste) and the coal mining/natural gas/petroleum industries each contribute about 8% to their respective global totals. The US is an insignificant contributor (< 1%) to global emissions of CH{sub 4} from rice paddies.

Duxbury, J.M. [Cornell Univ., Ithaca, NY (United States)

1993-12-31

295

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

NASA Astrophysics Data System (ADS)

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

Yurdakul, Sema; Civan, Mihriban; Tuncel, Gürdal

2013-02-01

296

73 FR 14125 - National Emission Standards for Hazardous Air Pollutants: Area Source Standards for Plating and...  

Federal Register 2010, 2011, 2012, 2013

...potential to cause more emissions...polishing area sources, all the PM...the affected source to the control...or, for new sources, want to control...polishing area source category...bubbles which cause the misting...is another source of emissions...and polishing sources, at 10...

2008-03-14

297

Carbonyl emissions from vehicular exhausts sources in Hong Kong.  

PubMed

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

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

2012-02-01

298

Atmospheric measurement of point source fossil fuel CO2 emissions  

NASA Astrophysics Data System (ADS)

We use the Kapuni Gas Treatment Plant to examine methodologies for atmospheric monitoring of point source fossil fuel CO2 (CO2ff) emissions. The Kapuni plant, located in rural New Zealand, removes CO2 from locally extracted natural gas and vents that CO2 to the atmosphere, at a rate of ~0.1 Tg carbon per year. The plant is located in a rural dairy farming area, with no other significant CO2ff sources nearby, but large, diurnally varying, biospheric CO2 fluxes from the surrounding highly productive agricultural grassland. We made flask measurements of CO2 and 14CO2 (from which we derive the CO2ff component) and in situ measurements of CO2 downwind of the Kapuni plant, using a Helikite to sample transects across the emission plume from the surface up to 100 m a.g.l. We also determined the surface CO2ff content averaged over several weeks from the 14CO2 content of grass samples collected from the surrounding area. We use the WindTrax plume dispersion model to compare the atmospheric observations with the emissions reported by the Kapuni plant, and to determine how well atmospheric measurements can constrain the emissions. The model has difficulty accurately capturing the fluctuations and short-term variability in the Helikite samples, but does quite well in representing the observed CO2ff in 15 min averaged surface flask samples and in ~1 week integrated CO2ff averages from grass samples. In this pilot study, we found that using grass samples, the modeled and observed CO2ff emissions averaged over one week agreed to within 30%. The results imply that greater verification accuracy may be achieved by including more detailed meteorological observations and refining 14CO2 sampling strategies.

Turnbull, J. C.; Keller, E. D.; Baisden, W. T.; Brailsford, G.; Bromley, T.; Norris, M.; Zondervan, A.

2013-11-01

299

Atmospheric measurement of point source fossil CO2 emissions  

NASA Astrophysics Data System (ADS)

We use the Kapuni Gas Treatment Plant to examine methodologies for atmospheric monitoring of point source fossil fuel CO2 (CO2ff) emissions. The Kapuni plant, located in rural New Zealand, removes CO2 from locally extracted natural gas and vents that CO2 to the atmosphere, at a rate of ~0.1 Tg carbon per year. The plant is located in a rural dairy farming area, with no other significant CO2ff sources nearby, but large, diurnally varying, biospheric CO2 fluxes from the surrounding highly productive agricultural grassland. We made flask measurements of CO2 and 14CO2 (from which we derive the CO2ff component) and in situ measurements of CO2 downwind of the Kapuni plant, using a Helikite to sample transects across the emission plume from the surface up to 100 m above ground level. We also determined the surface CO2ff content averaged over several weeks from the 14C content of grass samples collected from the surrounding area. We use the WindTrax plume dispersion model to compare the atmospheric observations with the emissions reported by the Kapuni plant, and to determine how well atmospheric measurements can constrain the emissions. The model has difficulty accurately capturing the fluctuations and short-term variability in the Helikite samples, but does quite well in representing the observed CO2ff in 15 min averaged surface flask samples and in ~ one week integrated CO2ff averages from grass samples. In this pilot study, we found that using grass samples, the modeled and observed CO2ff emissions averaged over one week agreed to within 30%. The results imply that greater verification accuracy may be achieved by including more detailed meteorological observations and refining 14C sampling strategies.

Turnbull, J. C.; Keller, E. D.; Baisden, T.; Brailsford, G.; Bromley, T.; Norris, M.; Zondervan, A.

2014-05-01

300

The source location of certain Jovian decametric radio emissions  

NASA Technical Reports Server (NTRS)

Evidence is presented which supports the concept that certain of the Jovian decametric radio waves originate as northern hemisphere extraordinary mode cyclotron emissions. The wave signals received by Voyager 1 near 10 MHz shortly after the closest approach to Jupiter were found to exhibit cusps in the fringe pattern which can be attributed to Faraday rotation in the Io plasma torus. At nearly the same time, the wave polarization near 1 MHz was found to exhibit a sudden reversal of its rotation sense, indicating that the wave path for those frequencies had also become perpendicular to the magnetic field at the spacecraft. It was determined that the waves came from the northern hemisphere at progressively lower altitudes with increasing frequency, and if the source is assumed to be associated with an L = 6 field line, the emission appears to have occurred near the source cyclotron frequency somewhere in the local midnight sector. The evidence indicates that the source is at the Io flux tube and that the emitted wave mode must have been extraordinary. In addition, the emitted wave polarization must have been substantially noncircular which would require a low plasma density near the source, much like that which occurs with auroral kilometric radiation at the earth.

Calvert, W.

1983-01-01

301

40 CFR 63.3091 - What emission limits must I meet for an existing affected source?  

Code of Federal Regulations, 2013 CFR

...POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Surface Coating of Automobiles and Light-Duty Trucks Emission Limitations § 63.3091 What emission limits must I meet for an existing...

2013-07-01

302

Scenarios of global mercury emissions from anthropogenic sources  

NASA Astrophysics Data System (ADS)

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

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

2013-11-01

303

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

EPA Science Inventory

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

304

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

EPA Science Inventory

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

305

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

Code of Federal Regulations, 2012 CFR

... false What emission limits must I meet for tire production affected sources? 63.5984 Section...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Emission Limits for Tire Production Affected Sources § 63.5984...

2012-07-01

306

40 CFR Table 1 to Subpart Xxxx of... - Emission Limits for Tire Production Affected Sources  

...2014-07-01 false Emission Limits for Tire Production Affected Sources 1 Table...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX...XXXX of Part 63—Emission Limits for Tire Production Affected Sources As...

2014-07-01

307

40 CFR Table 1 to Subpart Xxxx of... - Emission Limits for Tire Production Affected Sources  

Code of Federal Regulations, 2011 CFR

...2009-07-01 true Emission Limits for Tire Production Affected Sources 1 Table...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX...XXXX of Part 63—Emission Limits for Tire Production Affected Sources As...

2011-07-01

308

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

Code of Federal Regulations, 2013 CFR

... true What emission limits must I meet for tire production affected sources? 63.5984 Section...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Emission Limits for Tire Production Affected Sources § 63.5984...

2013-07-01

309

40 CFR Table 2 to Subpart Xxxx of... - Emission Limits for Tire Cord Production Affected Sources  

Code of Federal Regulations, 2010 CFR

...2010-07-01 true Emission Limits for Tire Cord Production Affected Sources 2 ...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX...XXXX of Part 63—Emission Limits for Tire Cord Production Affected Sources As...

2010-07-01

310

40 CFR Table 1 to Subpart Xxxx of... - Emission Limits for Tire Production Affected Sources  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Emission Limits for Tire Production Affected Sources 1 Table...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX...XXXX of Part 63—Emission Limits for Tire Production Affected Sources As...

2012-07-01

311

40 CFR Table 1 to Subpart Xxxx of... - Emission Limits for Tire Production Affected Sources  

Code of Federal Regulations, 2013 CFR

...2012-07-01 true Emission Limits for Tire Production Affected Sources 1 Table...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX...XXXX of Part 63—Emission Limits for Tire Production Affected Sources As...

2013-07-01

312

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

Code of Federal Regulations, 2010 CFR

... true What emission limits must I meet for tire production affected sources? 63.5984 Section...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Emission Limits for Tire Production Affected Sources § 63.5984...

2010-07-01

313

40 CFR Table 2 to Subpart Xxxx of... - Emission Limits for Tire Cord Production Affected Sources  

Code of Federal Regulations, 2011 CFR

...2009-07-01 true Emission Limits for Tire Cord Production Affected Sources 2 ...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX...XXXX of Part 63—Emission Limits for Tire Cord Production Affected Sources As...

2011-07-01

314

40 CFR Table 2 to Subpart Xxxx of... - Emission Limits for Tire Cord Production Affected Sources  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Emission Limits for Tire Cord Production Affected Sources 2 ...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX...XXXX of Part 63—Emission Limits for Tire Cord Production Affected Sources As...

2012-07-01

315

40 CFR Table 2 to Subpart Xxxx of... - Emission Limits for Tire Cord Production Affected Sources  

...2014-07-01 false Emission Limits for Tire Cord Production Affected Sources 2 ...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX...XXXX of Part 63—Emission Limits for Tire Cord Production Affected Sources As...

2014-07-01

316

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

... false What emission limits must I meet for tire production affected sources? 63.5984 Section...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Emission Limits for Tire Production Affected Sources § 63.5984...

2014-07-01

317

40 CFR Table 2 to Subpart Xxxx of... - Emission Limits for Tire Cord Production Affected Sources  

Code of Federal Regulations, 2013 CFR

...2012-07-01 true Emission Limits for Tire Cord Production Affected Sources 2 ...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX...XXXX of Part 63—Emission Limits for Tire Cord Production Affected Sources As...

2013-07-01

318

40 CFR Table 1 to Subpart Xxxx of... - Emission Limits for Tire Production Affected Sources  

Code of Federal Regulations, 2010 CFR

...2010-07-01 true Emission Limits for Tire Production Affected Sources 1 Table...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Pt. 63, Subpt. XXXX...XXXX of Part 63—Emission Limits for Tire Production Affected Sources As...

2010-07-01

319

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

Code of Federal Regulations, 2011 CFR

... true What emission limits must I meet for tire production affected sources? 63.5984 Section...Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing Emission Limits for Tire Production Affected Sources § 63.5984...

2011-07-01

320

64 FR 17460 - National Emission Standards for Hazardous Air Pollutants for Source Categories: Amendment for...  

Federal Register 2010, 2011, 2012, 2013

...Hazardous Air Pollutants for Source Categories: Amendment for...Hazardous Air Pollutants for Source Categories: Amendment for...compliance flexibility for affected sources without any adverse environmental...controlling the largest emissions source at their facilities....

1999-04-09

321

Source impact quantification of anthropogenic and biogenic emissions on regional ozone in the Mexico-U.S. border area using direct sensitivity analysis  

SciTech Connect

Transboundary air pollution between the US and Mexico has received increased attention since the late '70s. The Mexico-US border area provides the opportunity to investigate ozone air pollution at urban and rural scales in the presence of very different anthropogenic and biogenic emission characteristics. In order to elucidate the impact of control strategies to reduce air pollution levels, an understanding of pollutant transport across the border is necessary, as well as a characterization of major anthropogenic and biogenic emission sources of ozone precursors. A previous air quality modeling study of the border area lacked a biogenic emissions inventory. In this study, an episodic biogenic hydrocarbon and nitric oxide emission inventory was developed for the Mexico-US border area using GIS data and the Biogenic Emissions Inventory System (BEIS2). Then, the evolution of air pollutants was simulated using an Eulerian photochemical airshed model with the emission inventory accounting for both anthropogenic and biogenic emissions. Ground-level ozone was compared with a previous simulation that only incorporated anthropogenic emissions. Ozone levels increased throughout the domain, especially in the urban areas. Model performance, in general, improved against the run without biogenics, though results were biased towards ozone overprediction. The sensitivity of the ozone field to biogenic and anthropogenic emissions was calculated using a decoupled direct method for three dimensional air quality models (DDM-3D). DDM-3D revealed NO{sub x}-inhibited and VOC-limited areas. Finally, DDM-3D was used to analyze quantitatively the impact of different emission sources on ground-level ozone at urban and rural scales.

Mendoza-Dominguez, A.; Wilkinson, J.G.; Yang, Y.J.; Russell, A.G.

1999-07-01

322

Modeling unsteady-state VOC transport in simulated waste drums. Revision 1  

SciTech Connect

This report is a revision of an EG&G Idaho informal report originally titled Modeling VOC Transport in Simulated Waste Drums. A volatile organic compound (VOC) transport model has been developed to describe unsteady-state VOC permeation and diffusion within a waste drum. Model equations account for three primary mechanisms for VOC transport from a void volume within the drum. These mechanisms are VOC permeation across a polymer boundary, VOC diffusion across an opening in a volume boundary, and VOC solubilization in a polymer boundary. A series of lab-scale experiments was performed in which the VOC concentration was measured in simulated waste drums under different conditions. A lab-scale simulated waste drum consisted of a sized-down 55-gal metal drum containing a modified rigid polyethylene drum liner. Four polyethylene bags were sealed inside a large polyethylene bag, supported by a wire cage, and placed inside the drum liner. The small bags were filled with VOC-air gas mixture and the VOC concentration was measured throughout the drum over a period of time. Test variables included the type of VOC-air gas mixtures introduced into the small bags, the small bag closure type, and the presence or absence of a variable external heat source. Model results were calculated for those trials where the permeability had been measured.

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

1994-01-01

323

Major sources of exposure to benzene and other volatile organic chemicals  

Microsoft Academic Search

The major sources of human exposure to about a dozen volatile organic chemicals (VOCs) have recently been identified. For nearly every chemical, the major sources of exposure are completely different from the major sources of emissions. This finding implies that current environmental regulations and control strategies are misdirected. Important sources of exposure are typically not regulated in any way, whereas

Lance Wallace

1990-01-01

324

mVOC: a database of microbial volatiles  

PubMed Central

Scents are well known to be emitted from flowers and animals. In nature, these volatiles are responsible for inter- and intra-organismic communication, e.g. attraction and defence. Consequently, they influence and improve the establishment of organisms and populations in ecological niches by acting as single compounds or in mixtures. Despite the known wealth of volatile organic compounds (VOCs) from species of the plant and animal kingdom, in the past, less attention has been focused on volatiles of microorganisms. Although fast and affordable sequencing methods facilitate the detection of microbial diseases, however, the analysis of signature or fingerprint volatiles will be faster and easier. Microbial VOCs (mVOCs) are presently used as marker to detect human diseases, food spoilage or moulds in houses. Furthermore, mVOCs exhibited antagonistic potential against pathogens in vitro, but their biological roles in the ecosystems remain to be investigated. Information on volatile emission from bacteria and fungi is presently scattered in the literature, and no public and up-to-date collection on mVOCs is available. To address this need, we have developed mVOC, a database available online at http://bioinformatics.charite.de/mvoc. PMID:24311565

Lemfack, Marie Chantal; Nickel, Janette; Dunkel, Mathias; Preissner, Robert; Piechulla, Birgit

2014-01-01

325

Near-field beamforming analysis for acoustic emission source localization.  

PubMed

This paper attempts to introduce a near-field acoustic emission (AE) beamforming method to estimate the AE source locations by using a small array of sensors closely placed in a local region. The propagation characteristics of AE signals are investigated based on guided wave theory to discuss the feasibility of using beamforming techniques in AE signal processing. To validate the effectiveness of the AE beamforming method, a series of pencil lead break tests at various regions of a thin steel plate are conducted. The potential of this method for engineering applications are explored through rotor-stator rubbing tests. The experimental results demonstrate that the proposed method can effectively determine the region where rubbing occurs. It is expected that the work of this paper may provide a helpful analysis tool for near-field AE source localization. PMID:22209088

He, Tian; Pan, Qiang; Liu, Yaoguang; Liu, Xiandong; Hu, Dayong

2012-07-01

326

Visualization of the exothermal VOC adsorption in a fixed-bed activated carbon adsorber  

Microsoft Academic Search

Activated carbon fixed beds are classically used to remove volatile organic compounds (VOCs) present in gaseous emissions. In such use, an increase of local temperature due to exothermal adsorption has been reported; some accidental fires in the carbon bed due to the removal of high concentrations of ketones have been published. In this work, removal of VOCs was performed in

P. Le Cloirec; P. Pré; F. Delage; S. Giraudet

2012-01-01

327

Visualization of the exothermal VOC adsorption in a fixed-bed activated carbon adsorber  

Microsoft Academic Search

Activated carbon fixed beds are classically used to remove volatile organic compounds (VOCs) present in gaseous emissions. In such use, an increase of local temperature due to exothermal adsorption has been reported; some accidental fires in the carbon bed due to the removal of high concentrations of ketones have been published. In this work, removal of VOCs was performed in

P. Le Cloirec; P. Pré; F. Delage; S. Giraudet

2011-01-01

328

Characterization of selenium in ambient aerosols and primary emission sources.  

PubMed

Atmospheric selenium (Se) in aerosols was investigated using X-ray absorption near-edge structure (XANES) spectroscopy and X-ray fluorescence (XRF) microscopy. These techniques were used to determine the oxidation state and elemental associations of Se in common primary emission sources and ambient aerosols collected from the greater Atlanta area. In the majority of ambient aerosol and primary emission source samples, the spectroscopic patterns as well as the absence of elemental correlations suggest Se is in an elemental, organic, or oxide form. XRF microscopy revealed numerous Se-rich particles, or hotspots, accounting on average for ?16% of the total Se in ambient aerosols. Hotspots contained primarily Se(0)/Se(-II). However, larger, bulk spectroscopic characterizations revealed Se(IV) as the dominant oxidation state in ambient aerosol, followed by Se(0)/Se(-II) and Se(VI). Se(IV) was the only observed oxidation state in gasoline, diesel, and coal fly ash, while biomass burning contained a combination of Se(0)/Se(-II) and Se(IV). Although the majority of Se in aerosols was in the most toxic form, the Se concentration is well below the California Environmental Protection Agency chronic exposure limit (?20000 ng/m(3)). PMID:25075640

De Santiago, Arlette; Longo, Amelia F; Ingall, Ellery D; Diaz, Julia M; King, Laura E; Lai, Barry; Weber, Rodney J; Russell, Armistead G; Oakes, Michelle

2014-08-19

329

Significance of the Development of VOC Sensors  

NASA Astrophysics Data System (ADS)

The environmental problems relevant to VOC, such as sick house syndrome and air pollution, have attracted attention more and more. Japanese government has recently set forth the measure to VOC by amendments to related codes and regulations. The measurement technology and sensors for hazardous chemical substances, formaldehyde, toluene and xylene, are important to control the VOC level. The development of VOC sensors is desired because it is possible to measure VOC concentration simply and quickly, which makes it possible to realize the constant self-management of VOC and to check the real time change of VOC level. Since the performance requirements to a VOC sensor depend much on the applications, it is necessary to figure out the required specifications before starting the development of target VOC sensors. High performance VOC sensors applicable to many application fields are required to construct a secure and safe society.

Matsubara, Ichiro; Itoh, Toshio; Murayama, Norimitsu

330

40 CFR 63.5988 - What emission limitations must I meet for puncture sealant application affected sources?  

Code of Federal Regulations, 2012 CFR

...emission limitations must I meet for puncture sealant application affected sources? 63...Manufacturing Emission Limitations for Puncture Sealant Application Affected Sources § 63...emission limitations must I meet for puncture sealant application affected sources?...

2012-07-01

331

40 CFR 63.5988 - What emission limitations must I meet for puncture sealant application affected sources?  

Code of Federal Regulations, 2011 CFR

...emission limitations must I meet for puncture sealant application affected sources? 63...Manufacturing Emission Limitations for Puncture Sealant Application Affected Sources § 63...emission limitations must I meet for puncture sealant application affected sources?...

2011-07-01

332

40 CFR 63.5988 - What emission limitations must I meet for puncture sealant application affected sources?  

Code of Federal Regulations, 2010 CFR

...emission limitations must I meet for puncture sealant application affected sources? 63...Manufacturing Emission Limitations for Puncture Sealant Application Affected Sources § 63...emission limitations must I meet for puncture sealant application affected sources?...

2010-07-01

333

40 CFR 63.5988 - What emission limitations must I meet for puncture sealant application affected sources?  

...emission limitations must I meet for puncture sealant application affected sources? 63...Manufacturing Emission Limitations for Puncture Sealant Application Affected Sources § 63...emission limitations must I meet for puncture sealant application affected sources?...

2014-07-01

334

40 CFR 63.5988 - What emission limitations must I meet for puncture sealant application affected sources?  

Code of Federal Regulations, 2013 CFR

...emission limitations must I meet for puncture sealant application affected sources? 63...Manufacturing Emission Limitations for Puncture Sealant Application Affected Sources § 63...emission limitations must I meet for puncture sealant application affected sources?...

2013-07-01

335

Evaluation of emission control strategies to reduce ozone pollution in the Paso del Norte region using a photochemical air quality modeling system  

NASA Astrophysics Data System (ADS)

Air pollution emissions control strategies to reduce ozone precursor pollutants are analyzed by applying a photochemical modeling system. Simulations of air quality conditions during an ozone episode which occurred in June, 2006 are undertaken by increasing or reducing area source emissions in Ciudad Juarez, Chihuahua, Mexico. Two air pollutants are primary drivers in the formation of tropospheric ozone. Oxides of nitrogen (NOx) and volatile organic compounds (VOC) undergo multiple chemical reactions under favorable meteorological conditions to form ozone, which is a secondary pollutant that irritates respiratory systems in sensitive individuals especially the elderly and young children. The U.S. Environmental Protection Agency established National Ambient Air Quality Standards (NAAQS) to limit ambient air pollutants such as ozone by establishing an 8-hour average concentration of 0.075 ppm as the threshold at which a violation of the standard occurs. Ozone forms primarily due reactions in the troposphere of NOx and VOC emissions generated primarily by anthropogenic sources in urban regions. Data from emissions inventories indicate area sources account for ˜15 of NOx and ˜45% of regional VOC emissions. Area sources include gasoline stations, automotive paint bodyshops and nonroad mobile sources. Multiplicity of air pollution emissions sources provides an opportunity to investigate and potentially implement air quality improvement strategies to reduce emissions which contribute to elevated ozone concentrations. A baseline modeling scenario was established using the CAMx photochemical air quality model from which a series of sensitivity analyses for evaluating air quality control strategies were conducted. Modifications to area source emissions were made by varying NOx and / or VOC emissions in the areas of particular interest. Model performance was assessed for each sensitivity analysis. Normalized bias (NB) and normalized error (NE) were used to identify variability of the PREDICTED to OBSERVED ozone concentrations of both BASELINE model and simulations with modified emissions assessed by the sensitivity analysis. All simulations were found to vary within acceptable ranges of these two criteria variables. Simulation results indicate ozone formation in the PdN region is VOC-limited. Under VOC-limited conditions, modifications to NOx emissions do not produce a marked increase or decrease in ozone concentrations. Modifications to VOC emissions generated the highest variability in ozone concentrations. Increasing VOC emissions by 75% produced results which minimized model bias and error when comparing PREDICTED and OBSERVED ozone concentrations. Increasing VOC emissions by 75% either alone or in combination with a 75% increase in NOx emissions generated PREDICTED ozone concentrations very near to OBSERVED ozone. By evaluating the changes in ambient ozone concentrations through photochemical modeling, air quality planners may identify the most efficient or effective VOC emissions control strategies for area sources. Among the strategies to achieve emissions reductions are installation of gasoline vapor recovery systems, replacing high-pressure low-volume surface coating paint spray guns with high-volume low-pressure spray paint guns, requiring emissions control booths for surface coating operations as well as undertaking solvent management practices, requiring the sale of low VOC paint solvents in the surface-coating industry, and requiring low-VOC solvents in the dry cleaning industry. Other strategies to reduce VOC emissions include initiating Eco-Driving strategies to reduce fuel consumption from mobile sources and minimize vehicle idling at the international ports of entry by reducing bridge wait times. This dissertation depicts a tool for evaluating impacts of emissions on regional air quality by addressing the highly unresolved fugitive emissions in the Paso del Norte region. It provides a protocol for decision makers to assess the effects of various emission control strategies in the region. Impacts of specific sourc

Valenzuela, Victor Hugo

336

Particle number emissions and source signatures of an industrial facility.  

PubMed

The work presented was conducted within the scope of a larger study investigating impacts of the Stuart Oil Shale project, a facility operating to the north of the industrial city of Gladstone, Australia. The aims of the investigations were threefold: (a) the identification of the plant signatures in terms of particle size distributions in the submicrometer range (13-830 nm) through stack measurements, (b) exploring the applicability of these signatures in tracing the source contributions at locations of interest, at a distance from the plant, and (c) assessing the contribution of the plant to the total particle number concentration at locations of interest. The stack measurements conducted for three different conditions of plant operation showed that the particle size distributions were bimodal with average modal count median diameters (CMDs) of 24 (SD 4) and 52 (SD 9) nm. The average of all the particle size distributions recorded within the plant sector at a site located 4.5 km from the plant, over the sampling period when the plant was operating, also showed a bimodal distribution. The modal CMDs in this case were 27 and 50 nm, similar to those at the stack. This bimodal size distribution is distinct from the size distribution of the most common ambient anthropogenic emission source, which is vehicle emissions, and can be considered as a signature of this source. The average contribution of the plant (for plant sector winds) was estimated to be (10.0 +/- 3.8) x 10(2) particles cm(-3) and constituted approximately a 50% increase overthe local particle ambient concentration for plant sector winds. This increase in particle number concentration compared to the local background concentration, while high compared to the clean environment concentration, is not significant when compared to concentrations generally encountered in the urban environment of Brisbane. PMID:16509322

Morawska, L; Johnson, G R; He, C; Ayoko, G A; Lim, M C H; Swanson, C; Ristovski, Z D; Moore, M

2006-02-01

337

The GEIA global gridded inventory of anthropogenic VOCs  

SciTech Connect

Modeling assessments of the atmospheric chemistry, air quality and climatic conditions of the past, present and future require as input inventories of emissions of the appropriate chemical species constructed on appropriate spatial and temporal scales. The task of the Global Emissions Inventories Activity (GEIA) of the International Global Atmospheric Chemistry Project (IGAC) is the production of global inventories suitable for a range of research applications. Current GEIA programs are generally based on addressing emissions by species; an international working group of interested participants cooperates in the work needed to compile each inventory. The work of the GEIA program addressing the compilation of a global inventory of anthropogenic emissions of Volatile Organic Compounds (VOCs) gridded with 1{degree} resolution is presented. Past studies were used to identify anthropogenic activities according to their contribution to global VOC emissions, based on results of these initial studies, activity and species groupings for emissions reporting have been selected. Current status of the work of the committee is discussed. Detailed information on available activity rates, emission factors, and speciation profiles for each defined sector is being compiled. Links to investigators working on the compilation of VOC emissions on a regional level have been established.

Benkovitz, C.M. [Brookhaven National Lab., Upton, NY (United States); Berdowski, J.J.M.; Veldt, C. [IMW-TNO, Delft (Netherlands)

1995-04-01

338

GENERAL DESIGN STUDY OF PILOT VOC CONTROL UNITS  

EPA Science Inventory

The Industrial Environmental Research Laboratory (IERL), in support of the Office of Air Quality Planning and Standards Volatile Organic Compounds (VOC) Program, has established a project for design, construction and operation of four pilot emission control units which will be tr...

339

76 FR 35806 - Amendments to National Emission Standards for Hazardous Air Pollutants for Area Sources: Plating...  

Federal Register 2010, 2011, 2012, 2013

...for the trade. Regulated sources do not include chromium electroplating and chromium anodizing sources, as those sources are subject to 40 CFR part 63, subpart N, ``Chromium Emissions From Hard and Decorative Chromium...

2011-06-20

340

An overview of key emissions sources and ambient pollution characteristics from major cities in North America  

NASA Astrophysics Data System (ADS)

Many urban anthropogenic emission sources are difficult to characterize. They can be distributed across a spatial scale that precludes specific vector sampling. Others are difficult to identify a specific point of emissions. Novel emissions quantification methods, including fuel-based emission indicies and tracer flux ratio, are described and evaluated for a variety of urban pollution sources. These techniques can be used to quantify emissions for a large range of species including methane and carbon dioxide isotopes, formaldehyde and other toxic volatile organic carbon compounds, nitrogen oxides, carbon monoxide and black carbon particulate matter. Results from urban emissions source case-studies using a mobile laboratory either alone or in conjunction with tracer-release will be described. These include on road light duty and heavy duty vehicle emissions, in-use aircraft engine emissions at airports, and industrial emission sources.

Herndon, Scott; Fortner, Edward; Knighton, Berk; Floerchinger, Cody; Yacovitch, Tara; Roscioli, Rob; Zahniser, Mark; Nelson, David; Kolb, Charles; Zavala, Miguel; Molina, Luisa

2013-04-01

341

BASELINE EMISSIONS FORECASTS FOR INDUSTRIAL NON-BOILER SOURCES  

EPA Science Inventory

The report gives regional air emission forecasts from three Process Model Projection Technique (PROMPT) runs. These estimates illustrate a range of possible future emissions. PROMPT, one of a number of National Acid Precipitation Assessment Program emission forecasting models, pr...

342

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

...emission limitations or other control measures that are part of the applicable...emission limitations or other control measures that are part of the plan...emission limitations and other control measures that are part of the...

2014-07-01

343

Aggregation and analysis of volatile organic compound emissions for regional modeling  

NASA Astrophysics Data System (ADS)

A general two-step procedure for aggregating the hundreds of reported volatile organic compounds (VOCs) into a much smaller set of lumped classes appropriate for regional airshed modeling is described. In the first step, the compounds are condensed into a manageable number of emission categories which could be adapted to a variety of molecularly-based lumped chemical mechanisms. In the second step, the emissions are further aggregated into a smaller set of VOC classes which directly correspond to those in a particular model's mechanism. The application of this procedure is illustrated by aggregating the National Acid Precipitation Assessment Program (NAPAP) anthropogenic VOC emissions inventory the U.S. first into the 32-class system, and then into the groups of model species used in the latest version of the Regional Acid Deposition Model (RADM2.0). The importance of different VOC categories and source types on regional pollution production is explored by comparing the contributions of each of the emissions groupings, RADM model species, and major emissions sources, to total moles carbon VOC reacted in model simulations. For this particular anthropogenic inventory and chemical mechanism, it is found that over 50% of the moles carbon reacted is associated with mobile sources. Such analysis can help indicate which uncertainties in anthropogenic emissions inventories may have the greatest impact on results of regional simulations.

Middleton, Paulette; Stockwell, William R.; Carter, William P. L.

344

PAH diagnostic ratios for the identification of pollution emission sources.  

PubMed

Polycyclic aromatic hydrocarbon (PAH) diagnostic ratios have recently come into common use as a tool for identifying and assessing pollution emission sources. Some diagnostic ratios are based on parent PAHs, others on the proportions of alkyl-substituted to non-substituted molecules. The ratios are applicable to PAHs determined in different environmental media: air (gas + particle phase), water, sediment, soil, as well as biomonitor organisms such as leaves or coniferous needles, and mussels. These ratios distinguish PAH pollution originating from petroleum products, petroleum combustion and biomass or coal burning. The compounds involved in each ratio have the same molar mass, so it is assumed they have similar physicochemical properties. Numerous studies show that diagnostic ratios change in value to different extents during phase transfers and environmental degradation. The paper reviews applications of diagnostic ratios, comments on their use and specifies their limitations. PMID:22243855

Tobiszewski, Marek; Namie?nik, Jacek

2012-03-01

345

Emission Characteristics and Stability of Laser Ion Sources  

SciTech Connect

A new classification of laser ion sources concerning their pulse-to-pulse reproducibility in the ion emission is proposed. In particular, we distinguish between plasmas according to the electron distribution changing its characteristics at a laser intensity threshold of 10{sup 14} W/cm{sup 2}. Well reproducible continuous pulsed ion currents are typical for the intensity below the threshold. In contrast to this plasma the 'two-temperature' plasma arising for the intensity above this threshold shows not only a separation of charges in space and time but it also shows irregular and intense outbursts of ions similar to a self pulsing instability leading to a chaos. The sequence of fast ion outbursts visible on time-of-flight spectra is sensitive to details of non-linear interaction of the sub-nanosecond laser beam with the generated plasma.

Krasa, J.; Velyhan, A.; Krousky, E.; Laska, L.; Rohlena, K.; Jungwirth, K. [Institute of Physics A.S.C.R., v.v.i., Prague, 182 21 (Czech Republic); Ullschmied, J. [Institute of Plasma Physics A.S.C.R., v.v.i., Prague, 182 20 (Czech Republic); Lorusso, A.; Velardi, L.; Nassisi, V. [Department of Physics, University of Salento, Laboratorio di Elettronica Applicata e Strumentazione, L.E.A.S. I.N.F.N. sez. di Lecce, CP 193, 73100 Lecce (Italy); Czarnecka, A.; Ryc, L.; Parys, P.; Wolowksi, J. [Institute of Plasma Physics and Laser Microfusion, 00-908 Warsaw (Poland)

2010-10-13

346

Commuter exposures to VOCs in Boston, Massachusetts.  

PubMed

This study examines the commuter's exposure to six gasoline-related volatile organic compounds (VOCs): benzene, toluene, ethylbenzene, m-/p-xylene, o-xylene, and formaldehyde. The VOC concentrations to which commuters were exposed in four different commuting modes (driving, subway, walking, and biking) in Boston, Massachusetts, are compared. The VOC concentrations in participants' homes and offices were also measured. Factors that could influence in-vehicle VOC concentrations, such as different traffic patterns, car model and vehicle ventilation conditions, were also evaluated. Driving a private car was associated with higher VOC concentrations and commuting on urban roadways resulted in the highest VOC concentrations. The use of car heaters resulted in higher in-vehicle VOC concentrations. The longer the subway commuters stayed underground, the higher their VOC exposures. The home-to-work car or subway commute represented about 10 to 20 percent of an individual's total VOC exposure for these compounds. PMID:1799446

Chan, C C; Spengler, J D; Ozkaynak, H; Lefkopoulou, M

1991-12-01

347

Commuter exposures to VOCs in Boston, Massachusetts  

SciTech Connect

This study examines the commuter's exposure to six gasoline-related volatile organic compounds (VOCs): benzene, toluene, ethylbenzene, m-/p-xylene, o-xylene, and formaldehyde. The VOC concentrations to which commuters were exposed in four different commuting modes (driving, subway, walking, and biking) in Boston, Massachusetts, are compared. The VOC concentrations in participants' homes and offices were also measured. Factors that could influence in-vehicle VOC concentrations, such as different traffic patterns, car model and vehicle ventilation conditions, were also evaluated. Driving a private car was associated with higher VOC concentrations and commuting on urban roadways resulted in the highest VOC concentrations. The use of car heaters resulted in higher in-vehicle VOC concentrations. The longer the subway commuters stayed underground, the higher their VOC exposures. The home-to-work car or subway commute represented about 10 to 20 percent of an individual's total VOC exposure for these compounds.

Chan, C.C.; Spengler, J.D.; Ozkaynak, H.; Lefkopoulou, M. (Harvard School of Public Health, Boston, MA (United States))

1991-12-01

348

Volatile organic compound sources for Southern Finland  

NASA Astrophysics Data System (ADS)

Volatile organic compounds (VOCs) have several sources, both biogenic and anthropogenic. Emissions of biogenic VOCs in a global scale are estimated to be an order of magnitude higher than anthropogenic ones. However, in densely populated areas and during winter time the anthropogenic VOC emissions dominate over the biogenic ones. The aim of this study was to clarify potential local sources and source areas of VOCs in different seasons. Diurnal behaviour in winter and spring were also compared at two different sites in Finland: SMEAR II and III (Station for Measuring Ecosystem - Atmosphere Relations). SMEAR II is a rural site located in Hyytiälä in Southern Finland 220 km North-West from Helsinki whereas SMEAR III is background urban site located 5 km from the downtown of Helsinki. The volume mixing ratios of VOCs were measured with a proton-transfer-reaction mass spectrometer (PTR-MS, Ionicon Analytik GmbH, Austria) during years 2006-2011. Other trace gases such as CO, NOXand SO2 were also measured in both sites and used for source analysis. Source areas for long term VOC measurements were investigated with trajectory analysis and sources for local and regional concentrations were determined by Unmix multivariate receptor model. Forest fires affect air quality and the biggest smoke plumes can be seen in satellite images and even hinder visibility in the plume areas. They provide temporally and spatially well-defined sources that can be used to verify source area estimates. During the measurement periods two different forest fire episodes with several hotspots, happened in Russia. Forest fires which showed up in these measurements were in 2006 near the border of Finland in Vyborg area and 2010 in Moscow area. Forest fire episodes were clearly observed in trajectory analysis for benzene, toluene and methanol and also CO and NOX. In addition to event sources continuous source areas were determined. Anthropogenic local sources seemed to be dominant during winter in both sites. However during spring biogenic influence increased. In addition to source analysis this behaviour was visible in enhanced diurnal cycles of VOCs (Patokoski et al., 2014, in press). We will present important sources and source areas for Southern Finland's concentrations. References: Patokoski, J., Ruuskanen, T.M., Hellén, H., Taipale, R., Grönholm, T., Kajos, M.K., Petäjä, T., Hakola, H., Kulmala, M. & Rinne, J., 2014. Winter to spring transition and diurnal variation of VOCs in Finland at an urban background site and a rural site. Boreal Env. Res. 19. In press.

Patokoski, Johanna; Ruuskanen, Taina M.; Kajos, Maija K.; Taipale, Risto; Rantala, Pekka; Aalto, Juho; Ryyppö, Timo; Hakola, Hannele; Rinne, Janne

2014-05-01

349

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

NASA Astrophysics Data System (ADS)

Hybrid poplar is a fast-growing tree species that is likely to be an important source of biomass for the production of cellulose-based biofuels and may influence regional atmospheric chemistry through the emission of volatile organic compounds (VOCs). We used proton-transfer reaction mass spectrometry to measure VOC emissions from the leaves of four different hybrid poplar genotypes grown under ambient (400 ppm) and elevated (650 ppm) carbon dioxide concentration (CO2). The purpose of this experiment was to determine whether VOC emissions are different among genotypes and whether these emissions are likely to change as atmospheric CO2 rises. Methanol and isoprene made up over 90% of the VOC emissions and were strongly dependent on leaf age, with young leaves producing primarily methanol and switching to isoprene production as they matured. Monoterpene emissions were small, but tended to be higher in young leaves. Plants grown under elevated CO2 emitted smaller quantities of both methanol and isoprene, but the magnitude of the effect was dependent on genotype. Isoprene emission rates from mature leaves dropped from ~35 to ~28 nmol m-2 s-1 when plants were grown under elevated CO2. Emissions from individuals grown under ambient CO2 varied more based on genotype than those grown under elevated CO2, which means that we might expect smaller differences between genotypes in the future. Genotype and CO2 also affected how much carbon (C) individuals allocated to the production of VOCs. The emission rate of C from VOCs was 0.5 - 2% of the rate at which C was assimilated via net photosynthesis. The % C emitted was strongly related to genotype; clones from crosses between Populus deltoides and P. trichocarpa (T x D) allocated a greater % of their C to VOC emissions than clones from crosses of P. deltoids and P. nigra (D x N). Individuals from all four genotypes allocated a smaller % of their C to the emission of VOCs when they were grown under elevated CO2. These results illustrate that even in closely related individuals there are inherent differences in VOC emissions that are not due to simple differences in metabolic rates and that elevated CO2 reduces these inherent differences. Even though VOC rates were lower under elevated CO2 they were still much higher than emissions reported for switchgrass, another biofuel species, which means that future regional air quality around biofuel plantations will be influenced by the choice of biofuel species.

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

2010-12-01

350

The Estimation of CO2 Emission Factors for Combustion Sources in Oil and Gas Processing Plants  

Microsoft Academic Search

CO2 emission factors developed from fuel-specific data are more reliable than published average emission factors. In this article, CO2 emission factors were estimated for main combustion sources including gas turbines, boilers, and gas flares in an Iranian oil and gas processing plant using a fuel analysis method as well as direct measurements. In general, the emission factors for gas flares

D. Kahforoushan; E. Fatehifar; J. Soltan

2010-01-01

351

Source fingerprints for receptor modeling of volatile organics  

SciTech Connect

The development of receptor models for the determination of the sources of an ambient air pollution requires that the composition of the pollutant at the point of emissions be known. For this study, composition information for 10 sources of volatile organic compounds (VOC) were evaluated and source fingerprints developed. The source categories include motor vehicles, gasoline vapor, petroleum refineries, architectural coatings, graphic arts, waste-water treatment, vapor degreasing, dry cleaning, automobile assembly (including body painting), and polyethylene production. The fingerprints are presented for a group of 23 compounds. These compounds were selected for a variety of reasons including ease of measurement in the ambient environment, compound toxicity, reactivity, and usefulness in previous receptor modeling applications. In general, the data for sources of VOC are remarkably consistent from study to study. Because the profiles for many of the sources of VOC are controlled by physical and chemical process (e.g. combustion) and not raw material composition, the fingerprints have general applicability.

Scheff, P.A. (Illinois Institute of Chicago (USA)); Wadden, R.A.; Bates, B.A. (Univ. of Illinois, Chicago (USA)); Aronian, P.F. (UOP Inc., Des Plaines, IL (USA))

1989-04-01

352

EVALUATION AND PERFORMANCE ASSESSMENT OF INNOVATIVE LOW-VOC CONTACT ADHESIVES IN WOOD LAMINATING OPERATIONS  

EPA Science Inventory

The report gives results of an evaluation and assessment of the perfor-mance, economics, and emission reduction potential upon application of low-volatile organic compound (VOC) waterborne contact adhesive formulations specifically ina manual laminating operation for assembling s...

353

Modeled and observed ozone sensitivity to mobile-source emissions in Mexico City  

E-print Network

The emission characteristics of mobile sources in the Mexico City Metropolitan Area (MCMA) have changed significantly over the past few decades in response to emission control policies, advancements in vehicle technologies ...

Zavala, M.

354

75 FR 31895 - National Emission Standards for Hazardous Air Pollutants for Area Sources: Industrial, Commercial...  

Federal Register 2010, 2011, 2012, 2013

...numerical emissions limits, alternative approaches...work practice, or operational standard, or...sources that took operational limits to attain area...work practice, or operational standard, or combination...applicable emission limits: Table 1 to...

2010-06-04

355

40 CFR 63.1158 - Emission standards for new or reconstructed sources.  

Code of Federal Regulations, 2010 CFR

...PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL...EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES...Emission Standards for Hazardous Air Pollutants for Steel Pickling-HCl...Facilities and Hydrochloric Acid Regeneration Plants § 63.1158...

2010-07-01

356

40 CFR 63.1158 - Emission standards for new or reconstructed sources.  

Code of Federal Regulations, 2011 CFR

...PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL...EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES...Emission Standards for Hazardous Air Pollutants for Steel Pickling-HCl...Facilities and Hydrochloric Acid Regeneration Plants § 63.1158...

2011-07-01

357

[Characteristics of odors and VOCs from sludge direct drying process].  

PubMed

Co-processing sewage sludge by using the high-temperature feature of cement kiln can realize harmless disposal and energy recycling. In this paper, investigation on characteristics of the flue gas from sludge drying process was carried out in Guangzhou Heidelberg Yuexiu Cement Co., LTD. The composition and the main source of odors and volatile organic compounds (VOCs) emitted during the drying process were analyzed, aimed to provide scientific basis for the treatment of sewage sludge. Results showed that there were a large number of malodorous substances and VOCs in the flue gas. Sulfur dioxide and other sulfur-containing compounds were the main components in the malodorous substances, while benzene derivatives were predominant in VOCs. The compositions of odors and VOCs were influenced by the characteristics of the sludge and the heat medium (kiln tail gas). Total organic compounds in the sludge were significantly decreased after drying. Other organic substances such as volatile fatty acid, protein, and polysaccharide were also obviously reduced. The organic matter in sludge was the main source of VOCs in the flue gas. Part of sulfurous substances, such as sulfur dioxide, carbon disulfide, were from sulfur-containing substances in the sludge, and the rest were from the kiln tail gas itself. PMID:25338358

Chen, Wen-He; Deng, Ming-Jia; Luo, Hui; Zhang, Jing-Ying; Ding, Wen-Jie; Liu, Jun-Xin; Liu, Jun-Xin

2014-08-01

358

40 CFR 63.1316 - PET and polystyrene affected sources-emissions control provisions.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false PET and polystyrene affected sources-emissions...Group IV Polymers and Resins § 63.1316 PET and polystyrene affected sources—emissions...operator of an affected source producing PET using a continuous process shall...

2011-07-01

359

40 CFR 63.1316 - PET and polystyrene affected sources-emissions control provisions.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2011-07-01 true PET and polystyrene affected sources-emissions...Group IV Polymers and Resins § 63.1316 PET and polystyrene affected sources—emissions...operator of an affected source producing PET using a continuous process shall...

2012-07-01

360

40 CFR 63.1316 - PET and polystyrene affected sources-emissions control provisions.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false PET and polystyrene affected sources-emissions...Group IV Polymers and Resins § 63.1316 PET and polystyrene affected sources—emissions...operator of an affected source producing PET using a continuous process shall...

2013-07-01

361

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

362

Volatile Organic Compounds (VOCs)  

MedlinePLUS

... Basic Information on Pollutants and Sources of Indoor Air Pollution Asbestos Biological Pollutants Carbon Monoxide (CO) Formaldehyde/Pressed ... provides general solutions for resolving the syndrome. Indoor Air Pollution: An Introduction for Health Professionals Assists health professionals ( ...

363

Solution for acoustic field of thermo-acoustic emission from arbitrary source  

NASA Astrophysics Data System (ADS)

In this work, an expression for acoustic field of thermo-acoustic (TA) emission from arbitrary source is presented by deriving the solutions of TA emission from spherical surface and point source in gas and then taking advantage of the point sources superposition and the surface heat distribution factor. Accordingly, the computational analysis of acoustic pressure field of TA emission is extended to three-dimensional cases. The theory developed in this work is in good agreement with the experimental results and applicable for solving many complex and important TA emission problems including nanothermophones and phased array and impulse-driven TA emissions.

Hu, Hanping; Wang, Dongdong; Wang, Zedong

2014-10-01

364

Source location of the smooth high-frequency radio emissions from Uranus  

NASA Technical Reports Server (NTRS)

The source location of the smooth high-frequency radio emissions from Uranus has been determined. Specifically, by fitting the signal dropouts which occurred as Voyager traversed the hollow center of the emission pattern to a symmetrical cone centered on the source magnetic field direction at the cyclotron frequency, a southern-hemisphere (nightside) source was found at approximately 56 deg S, 219 deg W. The half-angle for the hollow portion of the emission pattern was found to be 13 deg.

Farrell, W. M.; Calvert, W.

1989-01-01

365

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

Federal Register 2010, 2011, 2012, 2013

...Air Pollutants for Source Categories; Wool...Air Pollutants for Source Categories; Wool...new and existing sources in wool fiberglass...include three metals (arsenic, chromium, lead...to these HAPs can cause reversible or irreversible...plants that are major sources to meet emission...Background B. NESHAP for Source Categories C....

1997-03-31

366

71 FR 59301 - National Emission Standards for Hazardous Air Pollutants for Area Sources: Polyvinyl Chloride and...  

Federal Register 2010, 2011, 2012, 2013

...Copper Smelting source category listing...metal emissions (arsenic, cadmium, chromium...and Beryllium source category was based...EPA ensure that sources representing 90...production include arsenic, cadmium, lead...nonferrous area source category was listed...production area sources? 1....

2006-10-06

367

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

Federal Register 2010, 2011, 2012, 2013

...major stationary sources. The annual compliance...facilities are major sources of HAP emissions...these pollutants can cause reversible or irreversible...are influenced by source-specific characteristics...least 2,869 major source aerospace manufacturing...million if all affected sources use chemical...

1995-09-01

368

ASPHALTIC CONCRETE INDUSTRY PARTICULATE EMISSIONS: SOURCE CATEGORY REPORT  

EPA Science Inventory

The report describes the development of particulate emission factors based on cutoff size for inhalable particles for the asphaltic concrete industry. After review of available information characterizing particulate emissions from asphalt concrete plants, the data were summarized...

369

7, 1470714745, 2007 VOCs measurements  

E-print Network

of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking two pollution episodes; however,10 the chemical composition of the VOCs did not exhibit noticeable of products, including electronics, communication, paper, garments and textiles, food, shoes, and plastic.5

Boyer, Edmond

370

VOCS IN MEXICO CITY AIR  

EPA Science Inventory

Mexico City, with nearly 20 million people, 3 million vehicles, and 35,000 industrial businesses, has severe photochemical air pollution. he 0, standard of 0.11 ppm is exceeded over 300 days of the year. ecause of the role of VOCs in the production of ozone, a study of the concen...

371

VOC Control in Kraft Mills  

Microsoft Academic Search

The formation of volatile organic compounds (VOCs), such as methanol, in kraft mills has been an environmental concern. Methanol is soluble in water and can increase the biochemical oxygen demand. Furthermore, it can also be released into atmosphere at the process temperatures of kraft mill-streams. The Cluster Rule of the EPA now requires the control of the release of methanol

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

2001-01-01

372

Sources and Controls on Oceanic Emission of Volatile Iodinated Compounds  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

373

Binary Pulsar Shock Emissions as Galactic Gamma-Ray Sources  

E-print Network

We address several issues regarding the interpretation of galactic \\ggg-ray sources. We consider powerful pulsars in binaries producing X-ray and gamma-ray {\\it unpulsed} emission from the shock interaction of relativistic pulsar winds with circumbinary material. Nebular mass outflows from companion stars of binary pulsars can provide the right {\\it calorimeters} to transform a fraction of the electromagnetic and kinetic energy of pulsar winds into high energy radiation. We discuss the physics of interaction of relativistic pulsar winds with gaseous material and show that the conditions in pulsar binary systems might be ideal to constrain shock acceleration mechanisms and pulsar wind composition and structure. We briefly discuss the example of the 47~ms pulsar PSR~1259-63 orbiting around a massive Be~star companion and monitored by X-ray and gamma-ray instruments during its recent periastron passage. In addition to young pulsars in massive binaries, also a class of recycled millisecond pulsars in low-mass binaries can be interesting high energy emitters.

M. Tavani

1995-02-10

374

Sources of variability in distortion product otoacoustic emissions  

PubMed Central

The goal of this study was to determine the extent to which the variability seen in distortion product otoacoustic emissions (DPOAEs), among ears with normal hearing, could be accounted for. Several factors were selected for investigation, including behavioral threshold, differences in middle-ear transmission characteristics either in the forward or the reverse direction, and differences in contributions from the distortion and reflection sources. These variables were assessed after optimizing stimulus parameters for individual ears at each frequency. A multiple-linear regression was performed to identify whether the selected variables, either individually or in combination, explained significant portions of variability in DPOAE responses. Behavioral threshold at the f2 frequency and behavioral threshold squared at that same frequency explained the largest amount of variability in DPOAE level, compared to the other variables. The combined model explained a small, but significant, amount of variance in DPOAE level at five frequencies. A large amount of residual variability remained, even at frequencies where the model accounted for significant amounts of variance. PMID:18681596

Garner, Cassie A.; Neely, Stephen T.; Gorga, Michael P.

2008-01-01

375

Modelling the NO emissions from wildfires at the source level  

NASA Astrophysics Data System (ADS)

There is a growing interest to characterize fire plumes in order to control air quality during wildfire episodes and to estimate the carbon and ozone balance of fire emissions. A numerical approach has been used to study the mechanisms of NO formation at the source level in wildfires given that NO plays an important role on the formation of ground-level ozone. The major reaction mechanisms involved in NO chemistry have been identified using reactions path analysis. Accordingly, a two-step global kinetic scheme in the gas phase has been proposed herein to account for the volatile fuel-bound nitrogen (fuel-N) conversion to NO, considering that the volatile fraction of fuel-N is released as NH3. Data from simulations using the PSR code from CHEMKIN-II package with a detailed kinetic mechanism (GDF-kin® 3.0) have been used to calibrate and evaluate the global model under typical wildfire conditions in terms of the composition of the degradation gases of vegetation, the equivalence ratio, the range of temperatures and the residence time.

Pérez-Ramirez, Y.; Santoni, P.-A.; Darabiha, N.

2013-12-01

376

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

Federal Register 2010, 2011, 2012, 2013

...businesses within the source category, two separate sources of information...subcategorize other source categories. Response...new and existing sources. Response: No...following types of sources are subject to...1) An area source that...

1999-06-01

377

Real-Time Observations of Secondary Aerosol Formation and Aging from Different Emission Sources and Environments  

NASA Astrophysics Data System (ADS)

To investigate atmospheric processing of direct urban and wildfire emissions, we deployed a photochemical flow reactor (Potential Aerosol Mass, PAM) with submicron aerosol size and chemical composition measurements during FLAME-3, a biomass-burning study at USDA Fire Sciences Laboratory in Missoula, MT, and CalNex, a field study investigating the nexus of air quality and climate change at a receptor site in the LA-Basin at Pasadena, CA. The reactor produces OH concentrations up to 4 orders of magnitude higher than in ambient air, achieving equivalent aging of ~2 weeks in 5 minutes of processing. The OH exposure (OHexp) was stepped every 20 min in both field studies. Results show the value of this approach as a tool for in-situ evaluation of changes in OA concentration and composition due to photochemical processing. In FLAME-3, the average OA enhancement factor was 1.42 × 0.36 of the initial POA. Reactive VOCs, such as toluene, monoterpenes, and acetaldehyde, decreased with increased OHexp; however, formic acid, acetone, and some unidentified OVOCs increased after significant exposure. Net SOA formation in the photochemical reactor increased with OHexp, typically peaking around 3 days of equivalent atmospheric photochemical age (OHexp ~3.9e11 molecules cm-3 s), then leveling off at higher exposures. Unlike other studies, no decrease in OA is observed at high exposure, likely due to lower max OHexp in this study due to very high OH reactivity. The amount of additional OA mass added from aging is positively correlated with initial POA concentration, but not with the total VOC concentration or the concentration of known SOA precursors. The mass of SOA formed often exceeded the mass of the known VOC precursors, indicating the likely importance of primary semivolatile/intermediate volatility species, and possibly of unidentified VOCs as SOA precursors in biomass burning smoke. Results from CalNex show enhancement of OA and inorganic aerosol from gas-phase precursors. The OA mass enhancement from aging was highest at night and correlated with trimethylbenzene concentrations, indicating the dominance of highly reactive VOC emissions as SOA precursors in the LA Basin. Aging in the reactor mimics atmospheric processing as the elemental composition of ambient and reactor measurements, when plotted in a Van Krevelen diagram, follow similar slopes; additionally, reactor measurements extend over a larger range of oxygen-to-carbon ratios (O/C) compared to that observed in the LA-Basin. While reactor aging always increases O/C, often beyond maximum ambient levels, we observe a transition from functionalization to fragmentation oxidation reactions at intermediate OHexp, with fragmentation dominating at very high OHexp. Maximum net SOA production is observed between 3-6 days of aging and decreases at higher exposures. A traditional SOA model with mostly aromatic precursors underpredicts the amount of SOA formed by an order-of-magnitude, which is consistent with model evaluations for ambient air at many polluted locations.

Ortega, A. M.; Palm, B. B.; Hayes, P. L.; Day, D. A.; Cubison, M.; Brune, W. H.; Hu, W.; Flynn, J. H.; Grossberg, N.; Lefer, B. L.; Rappenglueck, B.; Bon, D.; Graus, M.; Warneke, C.; Gilman, J.; Kuster, W.; De Gouw, J. A.; Jimenez, J. L.

2013-12-01

378

Seasonal variation of VOC concentrations above a boreal coniferous forest  

Microsoft Academic Search

Biogenic volatile organic compound (VOC) concentrations in ambient air were measured in Central Finland from April 2000 to April 2002. The concentrations of isoprene increased in May and declined in September, but the concentrations of its oxidation products, methacrolein and methyl vinyl ketone, remained at about 100ppt level also after that suggesting they might have anthropogenic sources as well. The

H Hakola; V Tarvainen; T Laurila; V Hiltunen; H Hellén; P Keronen

2003-01-01

379

40 CFR Table 1 to Subpart Kkkk of... - Emission Limits for New or Reconstructed Affected Sources  

Code of Federal Regulations, 2010 CFR

...Reconstructed Affected Sources 1 Table 1 to Subpart KKKK of Part...AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards...Subpt. KKKK, Table 1 Table 1 to Subpart KKKK...coatingsb. Two-piece food cans—all coatings...

2010-07-01

380

Global mercury emissions to the atmosphere from anthropogenic and natural sources  

NASA Astrophysics Data System (ADS)

This paper provides an up-to-date assessment of global mercury emissions from anthropogenic and natural sources. On an annual basis, natural sources account for 5207 Mg of mercury released to the global atmosphere, including the contribution from re-emission processes, which are emissions of previously deposited mercury originating from anthropogenic and natural sources, and primary emissions from natural reservoirs. Anthropogenic sources, which include a large number of industrial point sources, are estimated to account for 2320 Mg of mercury emitted annually. The major contributions are from fossil-fuel fired power plants (810 Mg yr-1), artisanal small scale gold mining (400 Mg yr-1), non-ferrous metals manufacturing (310 Mg yr-1), cement production (236 Mg yr-1), waste disposal (187 Mg yr-1) and caustic soda production (163 Mg yr-1). Therefore, our current estimate of global mercury emissions suggests that the overall contribution from natural sources (primary emissions+re-emissions) and anthropogenic sources is nearly 7527 Mg per year, the uncertainty associated with these estimates are related to the typology of emission sources and source regions.

Pirrone, N.; Cinnirella, S.; Feng, X.; Finkelman, R. B.; Friedli, H. R.; Leaner, J.; Mason, R.; Mukherjee, A. B.; Stracher, G. B.; Streets, D. G.; Telmer, K.

2010-02-01

381

Global mercury emissions to the atmosphere from anthropogenic and natural sources  

NASA Astrophysics Data System (ADS)

This paper provides an up-to-date assessment of global mercury emissions from anthropogenic and natural sources. On an annual basis, natural sources account for 5207 Mg of mercury released to the global atmosphere, including the contribution from re-emission processes, which are emissions of previously deposited mercury originating from anthropogenic and natural sources, and primary emissions from natural reservoirs. Anthropogenic sources, which include a large number of industrial point sources, are estimated to account for 2320 Mg of mercury emitted annually. The major contributions are from fossil-fuel fired power plants (810 Mg yr-1), artisanal small scale gold mining (400 Mg yr-1), non-ferrous metals manufacturing (310 Mg yr-1), cement production (236 Mg yr-1), waste disposal (187 Mg yr-1) and caustic soda production (163 Mg yr-1). Therefore, our current estimate of global mercury emissions suggests that the overall contribution from natural sources (primary emissions + re-emissions) and anthropogenic sources is nearly 7527 Mg per year, the uncertainty associated with these estimates are related to the typology of emission sources and source regions.

Pirrone, N.; Cinnirella, S.; Feng, X.; Finkelman, R. B.; Friedli, H. R.; Leaner, J.; Mason, R.; Mukherjee, A. B.; Stracher, G. B.; Streets, D. G.; Telmer, K.

2010-07-01

382

CONTROL OF HYDROCARBON EMISSIONS FROM GASOLINE LOADING BY REFRIGERATION SYSTEMS  

EPA Science Inventory

The report gives results of a study of the capabilities of refrigeration systems, operated at three temperatures, to control volatile organic compound (VOC) emissions from truck loading at bulk gasoline terminals. Achievable VOC emission rates were calculated for refrigeration sy...

383

Primary sources of selected POPs: regional and global scale emission inventories  

Microsoft Academic Search

During the last decade, a number of studies have been devoted to the sources and emissions of Persistent Organic Pollutants (POPs) at regional and global scales. While significant improvements in knowledge have been achieved for some pesticides, the quantitative understanding of the emission processes and emission patterns for “non-pesticide” POPs are still considered limited. The key issues remaining for the

Knut Breivik; Ruth Alcock; Yi-Fan Li; Robert E Bailey; Heidelore Fiedler; Jozef M Pacyna

2004-01-01

384

Tracking the sources of tropospheric ozone  

NASA Astrophysics Data System (ADS)

Tropospheric ozone is a harmful pollutant with adverse effects on human health and ecosystems. As well as these effects, tropospheric ozone is also a powerful greenhouse gas, with an anthropogenic radiative forcing one quarter of that of CO2. Along with methane and atmospheric aerosol, tropospheric ozone belongs to the so-called Short Lived Climate forcing Pollutants, or SLCP. Recent work has shown that efforts to reduce concentrations of SLCP in the atmosphere have the potential to slow the rate of near-term climate change, while simultaneously improving public health and reducing crop losses. Unlike many other SLCP, tropospehric ozone is not directly emitted, but is instead influenced by two distinct sources: transport of air from the ozone-rich stratosphere; and photochemical production in the troposphere from the emitted precursors NOx (oxides of nitrogen), CO (Carbon Monoxide), and VOC (volatile organic compounds, including methane). Better understanding of the relationship between ozone production and the emissions of its precursors is essential for the development of targeted emission reduction strategies. Several modeling methods have been employed to relate the production of tropospheric ozone to emissions of its precursors; emissions perturbation, tagging, and adjoint sensitivity methods all deliver complementary information about modelled ozone production. Most studies using tagging methods have focused on attribution of tropospheric ozone production to emissions of NOx, even though perturbation methods have suggested that tropospheric ozone is also sensitive to VOC, particularly methane. In this set of studies we examine the attribution of tropospheric ozone to emissions of VOC using a tagging approach, whereby each VOC oxidation intermediate in model chemical mechanisms is tagged with the identity of its primary emitted compound, allowing modelled ozone production to be directly attributed to all emitted VOCs in the model. Using a global model we examine the spatial and temporal extent of NOx-limited and VOC-limited regions with respect to ozone production chemistry, and we explore the sensitivity of the attributed ozone production to choices made during the tagging of the chemical mechanism. Using a regional model, we explore the extent to which transported VOC oxidation intermediates can be responsible for ozone production downwind of the original emissions source. Using a box model, we perform a detailed comparison of chemical mechanisms, examining the degree to which the explicitness of the representation of VOC oxidation intermediates influences the ozone production potential of VOC under idealised conditions. We also investigate uncertainties in the speciation of VOC emissions, as represented in state of the art emission inventories, and examine the extent to which these uncertainties can influence modelled ozone production. The representation of the emission of biogenic VOCs (BVOC) in our models is also improved. In particular, we implement a relationship between ozone stress and increased BVOC emissions. This is expected to be particularly important for urban trees. Based on the results of these studies, we recommend emission control measures based on their effectiveness in mitigating ozone air quality and climate forcing.

Butler, T. M.; Churkina, G.; Coates, J.; Grote, R.; Mar, K.; von Schneidemesser, E.; Zhu, S.

2013-12-01

385

Chemical composition of emissions from urban sources of fine organic aerosol  

Microsoft Academic Search

A dilution source sampling system was used to collect primary fine aerosol emissions from important sources of urban organic aerosol, including a boiler burning No. 2 fuel oil, a home fireplace, a fleet of catalyst-equipped and noncatalyst automobiles, heavy-duty diesel trucks, natural gas home appliances, and meat cooking operations. Alternative dilution sampling techniques were used to collect emissions from cigarette

Lynn M. Hildemann; Gregory R. Markowski; Glen R. Cass

1991-01-01

386

GLOBAL METHANE EMISSIONS FROM MINOR ANTHROPOGENIC SOURCES AND BIOFUEL COMBUSTION IN RESIDENTIAL STOVES (JOURNAL)  

EPA Science Inventory

Most global methane (CH4) budgets have failed to include emissions from a diverse group of minor anthropogenic sources. Individually, these minor sources emit small quantities of CH4, but collectively, their contributions to the budget may be significant. In this paper, CH4 emiss...

387

Air Quality: New Emissions Source Requirements Department: Chemical and General Safety  

E-print Network

Air Quality: New Emissions Source Requirements Department: Chemical and General Safety Program: Air Quality Owner: Program Manager Authority: ES&H Manual, Chapter 30, Air Quality1 All new sources that involve actual or potential air emissions must be evaluated by the air quality program manager beforehand

Wechsler, Risa H.

388

REGIONAL AIR POLLUTION STUDY: POINT AND AREA SOURCE ORGANIC EMISSION INVENTORY  

EPA Science Inventory

An inventory of organic emissions from stationary and mobile sources has been assembled for the St. Louis Air Quality Control Region. The inventory covers point and area sources for process, combustion and evaporative emissions. A breakdown into five categories has been assigned ...

389

Instantaneous Io flux tube as the source of Jovian DAM: Possible second harmonic emissions  

Microsoft Academic Search

To determine if the source of the Jovian Io-dependent DAM (decametric) emission is along the instantaneous Io flux tube (IIFT), the authors compare the results of ray-tracing calculations to radio emission data obtained by the Planetary Radio Astronomy instrument on board Voyager 1 and 2. They assume RX mode gyroemission at frequencies near the local gyrofrequency and sources along field

J. D. Menietti; D. B. Curran

1990-01-01

390

Instantaneous Io flux tube as the source of Jovian DAM - Possible second harmonic emissions  

Microsoft Academic Search

To determine if the source of the Jovian Io-dependent DAM (decametric) emission is along the instantaneous Io flux tube (IIFT), the results of ray-tracing calculations are compared with radio emission data obtained by the Planetary Radio Astronomy instruments on Voyager 1 and 2. RX mode gyroemission at frequencies near the local gyrofrequency and sources along field lines within the active

J. D. Menietti; D. B. Curran

1990-01-01

391

Model estimate of mercury emission from natural sources in East Asia  

Microsoft Academic Search

East Asia is one of the largest source regions that release mercury into the atmosphere. Although extensive studies have been devoted to estimating the anthropogenic mercury emission, little is known about mercury emission from natural sources in the region. In this study, we adapt the algorithms developed previously, coupled with detailed GIS data and satellite LAI products, to estimate mercury

Suraj K. Shetty; Che-Jen Lin; David G. Streets; Carey Jang

2008-01-01

392

[Characteristics of VOCs and their photochemical reactivity in autumn in Nanjing northern suburb].  

PubMed

A continuous observation campaign was carried out with the GC5000 volatile organics online monitoring system and the EMS system for one month in November 2011 in the northern suburb of Nanjing, and 56 VOC components and reactive gases (NO(x), CO and O3) were measured. The results showed that the VOC hourly averaged volume fraction in Nanjing northern suburb was about 48.17 x 10(-9), and the minimum value of VOCs occurred at 16:00. The diurnal variation showed a bimodal characteristic, indicating the significant impact of motor vehicle emission. The VOC concentration and O3 concentration exhibited negative correlation in the daytime. The average OH consumption rate of VOCs was approximately 3.26 x 10(-12) cm3 x (molecule x s)(-1), and the largest incremental reactivity was about 3.26 mol x mol(-1); Alkenes contributed the largest-parts of the OH consumption rate (L(OH)) and the ozone formation potential (OFP), followed by aromatics. Although alkanes were the most abundant components of VOCs in the atmosphere, it is not the main contributor of L(OH) and OFP. The key active components in VOCs were ethylene, propylene, 1-butene, m,p-xylene and isoprene, etc. The dominant factor of ozone formation was VOCs in this observation. PMID:24191532

Li, Yong-Yu; Zhu, Bin; An, Jun-Lin; Gao, Jin-Hui; Xia, Li; Zhang, Xiang-Zhi; Qin, Wei; Tang, Li-Li

2013-08-01

393

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

Federal Register 2010, 2011, 2012, 2013

...because it is known to cause, or may be reasonably...January 31, 1994). Sources that handle hydrogen...ensure that all major sources of air toxic emissions...controlled and lower emitting sources in each category. This...citizens that each major source of toxic air...

1998-09-21

394

Experimental biomass burning emission assessment by combustion chamber  

NASA Astrophysics Data System (ADS)

Biomass burning is a significant source of several atmospheric gases and particles and it represents an important ecological factor in the Mediterranean ecosystem. In this work we describe the performances of a recently developed combustion chamber to show the potential of this facility in estimating the emission from wildland fire showing a case study with leaves, small branches and litter of two representative species of Mediterranean vegetation, Quercus pubescens and Pinus halepensis. The combustion chamber is equipped with a thermocouple, a high resolution balance, an epiradiometer, two different sampling lines to collect organic volatile compounds (VOCs) and particles, a sampling line connected to a Proton Transfer Reaction Mass-Spectrometer (PTR-MS) and a portable analyzer to measure CO and CO2 emission. VOCs emission were both analyzed with GC-MS and monitored on-line with PTR-MS. The preliminary qualitative analysis of emission showed that CO and CO2 are the main gaseous species emitted during the smoldering and flaming phase, respectively. Many aromatics VOCs as benzene and toluene, and many oxygenated VOC as acetaldehyde and methanol were also released. This combustion chamber represents an important tool to determine the emission factor of each plant species within an ecosystem, but also the contribution to the emissions of the different plant tissues and the kinetics of different compound emissions during the various combustion phases. Another important feature of the chamber is the monitoring of the carbon balance during the biomass combustion.

Lusini, Ilaria; Pallozzi, Emanuele; Corona, Piermaria; Ciccioli, Paolo; Calfapietra, Carlo

2014-05-01

395

Measurement and Correlation of Ambient VOCs in Windsor, Ontario, Canada and Detroit, Michigan, USA  

NASA Astrophysics Data System (ADS)

An air quality study has been carried out in Windsor, Ontario, Canada and Detroit, Michigan, USA as part of a pilot research study undertaken by the Geospatial Determinants of Health Outcomes Consortium (GeoDHOC), a multidisciplinary, international effort aimed at understanding the health effects of air pollution in urban environments. Exposure to volatile organic compounds has long been associated with adverse health conditions such as atrophy of skeletal muscles, loss of coordination, neurological damage, dizziness, throat, nose, and eye irritation, nervous system depression, liver damage, and respiratory symptoms. Twenty-six species of ambient volatile organic compounds (VOCs) were monitored during a 2-week period in September, 2008 at 100 sites across Windsor and Detroit, using 3M # 3500 Organic Vapour Monitors. Ten species with highest concentrations were selected for further investigation; Toluene (mean concentration =4.14 ?m/m3), (m+p)-Xylene (2.30 ?m/m3), Hexane (1.87 ?m/m3), Benzene (1.37 ?m/m3), 1,2,4-Trimethylbenzene (0.87 ?m/m3), Dichloromethane (0.77 ?m/m3), Ethylbenzene (0.68 ?m/m3), o-Xylene (0.63 ?m/m3), n-Decane (0.42 ?m/m3), and 1,3,5-Trimethylbenzene (0.39 ?m/m3). Comparison to a similar investigation in Sarnia, Ontario in October 2005 revealed that the mean concentrations of VOCs were higher in Windsor-Detroit for all species by a significant margin (31-958%), indicating substantial impact of local industrial and vehicular emissions in the WindsorVDetroit area. For most VOCs, the concentrations were higher in Detroit than in Windsor. The mean concentration of total VOC was 9.7 ?m/m3 in Windsor, which is slightly higher than that in Sarnia in 2005 (7.9 um/m3), whilst total VOC concentration in Detroit was much higher (16.5 ?m/m3). There were strong correlations among several of the 10 species, with the highest Pearson correlation coefficients (r=0.78 - 0.99, p<0.05) amongst the BTEX (benzene, toluene, ethylbenzene, and xylenes) group, suggesting common sources of these species. The BTEX correlation for this study was in good agreement with that from the Sarnia results (Spearman rank correlation coefficient r=0.75 - 0.99), suggesting that one species may act as a proxy for the others in geographically similar regions.

Miller, L. J.; You, H.; Xu, X.; Molaroni, S.; Lemke, L.; Weglicki, L.; Krouse, H.; Krajenta, R.

2009-05-01

396

Emission Source Model of Jupiter's H + 3Aurorae: A Generalized Inverse Analysis of Images  

Microsoft Academic Search

We mapped the distribution of H+3emissions in Jupiter's polar regions utilizing 3.4-?m images acquired with ProtoCAM at the NASA IRTF. Two data sets, one acquired on February 28 and the other on March 22, 1992, were analyzed independently. A sequence of image mosaics was used to constrain the parameters of an emission source model. The emission source model utilizes an

Takehiko Satoh; John E. P. Connerney; Richard L. Baron

1996-01-01

397

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

NASA Astrophysics Data System (ADS)

Forests are complex sources of biogenic volatile organic compounds (VOC) in the planetary boundary layer. The impact of biogenic VOC on tropospheric photochem- istry, air quality, and the formation of secondary products affects our climate on a regional and global scale but is far from being understood. A considerable lack of knowledge exists concerning a forest stand as a net source of reactive trace com- pounds, which are transported directly into the planetary boundary layer (PBL). In particular, little is known about the amounts of VOC which are processed within the canopy. The goal of ECHO, which is presented in this poster, is to investigate these questions and to improve our understanding of biosphere-atmosphere interactions and their effects on the PBL. The investigation of emissions, chemical processing and vertical transport of biogenic VOC will be carried out in and above a mixed forest stand in Jülich, Germany. A large set of trace gases, free radicals and meteorologi- cal parameters will be measured at different heights in and above the canopy, covering concentrations of VOC, CO, O3, organic nitrates und NOx as well as organic aerosols. For the first time concentration profiles of OH, HO2, RO2 und NO3 radicals will be measured as well together with the actinic UV radiation field and photolysis frequen- cies of all relevant radical precursors (O3, NO2, peroxides, oxygenated VOC). The different tasks of the field experiments will be supported by simulation experiments investigating the primary emission and the uptake of VOC by the plants in stirred tank reactors, soil parameters and soil emissions in lysimeter experiments, and the chem- ical processing of the trace gases as observed in and above the forest stand in the atmosphere simulation chamber SAPHIR. The planning and interpretation of the field experiments is supported by simulations of the field site in a wind tunnel.

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

398

Source locations of narrowband radio emissions detected at Saturn  

Microsoft Academic Search

Since Cassini's arrival at Saturn in 2004, the Radio and Plasma Wave Science instrument has detected numerous narrowband (NB) radio emission events. These emissions, mostly detected around 5 and 20 kHz, usually occur periodically for several days after intensifications of Saturn kilometric radiation. We present calculations based on an electron density profile of Saturn's plasma torus and a dipole magnetic

Sheng-Yi Ye; D. A. Gurnett; G. Fischer; B. Cecconi; J. D. Menietti; W. S. Kurth; Z. Wang; G. B. Hospodarsky; P. Zarka; A. Lecacheux

2009-01-01

399

Ammonia emissions from non-agricultural sources in the UK  

Microsoft Academic Search

A detailed literature review has been undertaken of the magnitude of non-agricultural sources of ammonia (NH3) 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 NH3 as a solvent. Overall the

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

2000-01-01

400

Study Pinpoints Sources of Polluting Vehicle Emissions (Fact Sheet)  

SciTech Connect

Unburned lubricant produces 60%-90% of organic carbon emissions. While diesel fuel is often viewed as the most polluting of conventional petroleum-based fuels, emissions from gasoline engines can more significantly degrade air quality. Gasoline exhaust is at least as toxic on a per-unit-mass basis as diesel exhaust, and contributes up to 10 times more particulate matter (PM) to the emission inventory. Because emissions from both fuels can gravely impact health and the environment, researchers at the National Renewable Energy Laboratory (NREL) launched a study to understand how these pollutants relate to fuels, lubricants, and engine operating conditions. NREL's Collaborative Lubricating Oil Study on Emissions (CLOSE) project tested a variety of vehicles over different drive cycles at moderate (72 F) and cold (20 F) temperatures. Testing included: (1) Normal and high-emitting light-, medium-, and heavy-duty vehicles; (2) Gasoline, diesel, and compressed natural gas (CNG)-powered vehicles; (3) New and aged lubricants representative of those currently on the market; and (4) Gasoline containing no ethanol, E10, Texas-mandated low-emission diesel fuel, biodiesel, and CNG. The study confirmed that normally functioning emission control systems for gasoline light-duty vehicles are very effective at controlling organic carbon (OC) emissions. Diesel vehicles without aftertreatment emission control systems exhibited OC emissions approximately one order of magnitude higher than gasoline vehicles. High-emitter gasoline vehicles produced OC emissions similar to diesel vehicles without exhaust aftertreatment emission control. Exhaust catalysts combusted or converted more than 75% of lubricating oil components in the exhaust gases. Unburned crankcase lubricant made up 60%-90% of OC emissions. This OC represented 20%-50% of emitted PM in all but two of the vehicles. Three-way catalysts proved effective at reducing most of the OC. With high PM emitters or vehicles with deteriorated aftertreatment, high-molecular-weight fuel components and unburned lubricant were emitted at higher rates than in vehicles in good repair, with functioning emissions systems. Light-duty gasoline, medium-duty diesel, and heavy-duty natural gas vehicles produced more particles with fresh oil than with aged oil. The opposite trend was observed in light- and medium-duty high PM emitters. This effect was not readily apparent with heavy-duty diesel vehicles, perhaps because the lubricant represented a much smaller fraction of the total PM in those trucks.

Not Available

2012-03-01

401

Acidic deposition: state of science and technology. Report 25. Technologies and other measures for controlling emissions: Performance, costs, and applicability. Final report  

Microsoft Academic Search

The report focuses on the control options available to reduce the level of SO2, NO, and VOC emissions from the principle anthropogenic sources: electric utility and industrial boilers, industrial processes, and mobile sources. For each of these sources, the objective of the report is to summarize, through a comprehensive review, the status, applicability, performance, cost, secondary effects, and by-products of

D. W. South; J. L. Gillette; M. J. Bernard; D. G. Arey; K. A. McDermott

1990-01-01

402

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

SciTech Connect

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

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

1993-03-01

403

VOCs in fixed film processes. 2: Model studies  

SciTech Connect

Under the US Clean Air Act Amendments, fugitive emissions of volatile organic contaminants (VOCs) from waste-water-treatment facilities have been identified as a potentially significant source of air pollution. Models incorporating liquid-gas mass-transfer and biofilm mass-transfer resistances were developed for trickling filters (TF) and rotating biological contractors (RBC). Biodegradation and volatilization coefficients were estimated from the previously described pilot-scale studies. The volatilization coefficients of a given compound in the TF and RBC were generally constant across the experimental conditions investigated. While biodegradation-rate coefficients were constant in the TF across experimental conditions, in the RBC the biodegradation-rate coefficients appeared to be greatest under conditions of low loading and high disc rotation speed and lowest under conditions of high loading and low disk rotational speed. The biofilm was completely penetrated by most of the contaminants and diffusional resistance did not limit the rate of biodegradation of any of the compounds. In the RBC, diffusion in the biofilm appeared to be limiting the biodegradation of toluene, o-xylene, and 1,3,5-trimethylbenzene. The ratio of gas- and liquid-phase mass-transfer coefficients ranged from 91.4 for the TF to 5.6 for the RBC. Due to the relatively wide confidence intervals associated with these estimates, the values could not be statistically differentiated, however, the results suggest a significant contribution of gas-phase resistance to mass transfer in some cases.

Parker, W.J. [Carleton Univ., Ottawa, Ontario (Canada). Dept. of Civil and Environmental Engineering; Monteith, H.D. [Enviromega Ltd., Hamilton, Ontario (Canada); Melcer, H. [Brown and Caldwell Consultants, Seattle, WA (United States)

1996-07-01

404

New device for time-averaged measurement of volatile organic compounds (VOCs).  

PubMed

Contamination by volatile organic compounds (VOCs) in the environment is an increasing concern since these compounds are harmful to ecosystems and even to human health. Actually, many of them are considered toxic and/or carcinogenic. The main sources of pollution come from very diffuse focal points such as industrial discharges, urban water and accidental spills as these compounds may be present in many products and processes (i.e., paints, fuels, petroleum products, raw materials, solvents, etc.) making their control difficult. The presence of these compounds in groundwater, influenced by discharges, leachate or effluents of WWTPs is especially problematic. In recent years, law has been increasingly restrictive with the emissions of these compounds. From an environmental point of view, the European Water Framework Directive (2000/60/EC) sets out some VOCs as priority substances. This binding directive sets guidelines to control compounds such as benzene, chloroform, and carbon tetrachloride to be at a very low level of concentration and with a very high frequency of analysis. The presence of VOCs in the various effluents is often highly variable and discontinuous since it depends on the variability of the sources of contamination. Therefore, in order to have complete information of the presence of these contaminants and to effectively take preventive measures, it is important to continuously control, requiring the development of new devices which obtain average concentrations over time. As of today, due to technical limitations, there are no devices on the market that allow continuous sampling of these compounds in an efficient way and to facilitate sufficient detection limits to meet the legal requirements which are capable of detecting very sporadic and of short duration discharges. LABAQUA has developed a device which consists of a small peristaltic pump controlled by an electronic board that governs its operation by pre-programming. A constant flow passes through a glass cell containing adsorbent material where the VOCs are retained. The adsorbent used, made in LABAQUA, is a mixture of alginic acid and activated carbon. Due to its high permeability it allows the passage and retention of THMs in a suitable way, thus solving many of the problems of other common adsorbents. Also, to avoid degradation of the adsorbent, it is wrapped in a low density polyethylene (LDPE) membrane. After a sampling period of between 1 and 14 days, the adsorbent is collected and analyzed in the laboratory to quantify the VOC average concentration. This device resolves some of the limitations of the classical sampling system (spot samples), since we will take into account the fluctuations in the concentration of VOCs by averaging the same over time. This study presents the results obtained by the device for quantifying the VOCs legislated in the Directive 2000/60/EC. We present the validation of linearity over time and the limits of quantification, as well as the results of sample rate (Rs) obtained for each compound. The results demonstrate the high robustness and high sensitivity of the device. In addition the system has been validated in real waste water samples, comparing the results obtained with this device with the values of classical spot sampling, obtaining excellent results. PMID:24388502

Santiago Sánchez, Noemí; Tejada Alarcón, Sergio; Tortajada Santonja, Rafael; Llorca-Pórcel, Julio

2014-07-01

405

Analysis of Odor-Causing VOCs and Semi-VOCs Associated with Particulate Matter in Swine Barns Using SPME-GC-MS-Olfactometry  

NASA Astrophysics Data System (ADS)

Swine operations can affect air quality by emissions of odor, volatile organic compounds (VOCs) and other gases, and particulate matter (PM). Particulate matter has been proposed to be an important pathway for carrying odor. However, little is known about the odor-VOCs-PM interactions. In this research, continuous PM sampling was conducted simultaneously with three collocated TEOM analyzers inside a 1000-head swine finish barn located in central Iowa. Each TEOM (tapered element oscillating microbalance) was fitted with total suspended particulate (TSP), PM-10, PM-2.5 and PM-1 preseparators. Used filters were stored in 40 mL vials and transported to the laboratory. VOCs adsorbed/absorbed