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Sample records for volatile organic matter

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

    Science.gov (United States)

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

    2003-01-01

    A new classification scheme for the speciation of organic compound emissions for use in air quality models is described. The scheme uses 81 organic compound classes to preserve both net gas-phase reactivity and particulate matter (PM) formation potential. Chemical structure, vapor pressure, hydroxyl radical (OH) reactivity, freezing point/boiling point, and solubility data were used to create the 81 compound classes. Volatile, semivolatile, and nonvolatile organic compounds are included. The new classification scheme has been used in conjunction with the Canadian Emissions Processing System (CEPS) to process 1990 gas-phase and particle-phase organic compound emissions data for summer and winter conditions for a domain covering much of eastern North America. A simple postprocessing model was used to analyze the speciated organic emissions in terms of both gas-phase reactivity and potential to form organic PM. Previously unresolved compound classes that may have a significant impact on ozone formation include biogenic high-reactivity esters and internal C6-8 alkene-alcohols and anthropogenic ethanol and propanol. Organic radical production associated with anthropogenic organic compound emissions may be 1 or more orders of magnitude more important than biogenic-associated production in northern United States and Canadian cities, and a factor of 3 more important in southern U.S. cities. Previously unresolved organic compound classes such as low vapour pressure PAHs, anthropogenic diacids, dialkyl phthalates, and high carbon number alkanes may have a significant impact on organic particle formation. Primary organic particles (poorly characterized in national emissions databases) dominate total organic particle concentrations, followed by secondary formation and primary gas-particle partitioning. The influence of the assumed initial aerosol water concentration on subsequent thermodynamic calculations suggests that hydrophobic and hydrophilic compounds may form external

  2. Volatile Organic Compounds (VOCs)

    Science.gov (United States)

    ... Contact Us Share Volatile Organic Compounds' Impact on Indoor Air Quality On this page: Introduction Sources Health Effects Levels in Homes Steps to Reduce Exposure Standards or Guidelines Additional Resources Introduction Volatile organic compounds ( ...

  3. Production of volatile fatty acids from sewage organic matter by combined bioflocculation and alkaline fermentation

    NARCIS (Netherlands)

    Khiewwijit, R.; Temmink, B.G.; Rijnaarts, H.H.M.; Keesman, K.J.

    2015-01-01

    This study explored the potential of volatile fatty acids (VFA) production from sewage by a combined high-loaded membrane bioreactor and sequencing batch fermenter. VFA production was optimized with respect to SRT and alkaline pH (pH 8–10). Application of pH shock to a value of 9 at the start of a s

  4. Assessment of volatile organic compounds and particulate matter in a dental clinic and health risks to clinic personnel.

    Science.gov (United States)

    Hong, Yu-Jue; Huang, Yen-Ching; Lee, I-Long; Chiang, Che-Ming; Lin, Chitsan; Jeng, Hueiwang Anna

    2015-01-01

    This study was conducted to assess (1) levels of volatile organic compounds (VOCs) and particulate matter (PM) in a dental clinic in southern Taiwan and (2) dental care personnel's health risks associated with due to chronic exposure to VOCs. An automatic, continuous sampling system and a multi-gas monitor were employed to quantify the air pollutants, along with environmental comfort factors, including temperature, CO2, and relative humidity at six sampling sites in the clinic over eight days. Specific VOC compounds were identified and their concentrations were quantified. Both non-carcinogenic and carcinogenic VOC compounds were assessed based on the US Environmental Protection Agency's Principles of Health Risk Assessment in terms of whether those indoor air pollutants increased health risks for the full-time dental care professionals at the clinic. Increased levels of VOCs were recorded during business hours and exceeded limits recommended by the Taiwan Environmental Protection Agency. A total of 68 VOC compounds were identified in the study area. Methylene methacrylate (2.8 ppm) and acetone (0.176 ppm) were the only two non-carcinogenic compounds that posed increased risks for human health, yielding hazard indexes of 16.4 and 4.1, respectively. None of the carcinogenic compounds increased cancer risk. All detected PM10 levels ranged from 20 to 150 μg/m(3), which met the Taiwan EPA and international limits. The average PM10 level during business hours was significantly higher than that during non-business hours (P = 0.04). Improved ventilation capacity in the air conditioning system was recommended to reduce VOCs and PM levels.

  5. Volatile organic compounds and particulate matter in child care facilities in the District of Columbia: Results from a pilot study.

    Science.gov (United States)

    Quirós-Alcalá, L; Wilson, S; Witherspoon, N; Murray, R; Perodin, J; Trousdale, K; Raspanti, G; Sapkota, A

    2016-04-01

    Many young children in the U.S. spend a significant portion of their day in child care facilities where they may be exposed to contaminants linked to adverse health effects. Exposure data on volatile organic compounds (VOCs) and particulate matter (PM) in these settings is scarce. To guide the design of a larger exposure assessment study in urban child care facilities, we conducted a pilot study in which we characterized indoor concentrations of select VOCs and PM. We recruited 14 child care facilities in the District of Columbia (Washington, DC) and measured indoor concentrations of seven VOCs (n=35 total samples; 2-5 samples per facility): benzene, carbon tetrachloride, chloroform, ethylbenzene, o-xylene, p-xylene, and toluene in all facilities; and collected real-time PM measurements in seven facilities. We calculated descriptive statistics for contaminant concentrations and computed intraclass correlation coefficients (ICC) to evaluate the variability of VOC levels indoors. We also administered a survey to collect general health information on the children attending these facilities, and information on general housekeeping practices and proximity of facilities to potential sources of target contaminants. We detected six of the seven VOCs in the majority of child care facilities with detection frequencies ranging from 71% to 100%. Chloroform and toluene were detected in all samples. Median (range) concentrations for toluene, chloroform, benzene, o-xylene, ethylbenzene, and carbon tetrachloride were: 5.6µg/m(3) (0.6-16.5µg/m(3)), 2.8µg/m(3) (0.4-53.0µg/m(3)), 1.4µg/m(3) (below the limit of detection or

  6. Measurement of fine particulate matter nonvolatile and semi-volatile organic material with the Sunset Laboratory Carbon Aerosol Monitor.

    Science.gov (United States)

    Grover, Brett D; Kleinman, Michael; Eatough, Norman L; Eatough, Delbert J; Cary, Robert A; Hopke, Philip K; Wilson, William E

    2008-01-01

    Semi-volatile organic material (SVOM) in fine particles is not reliably measured with conventional semicontinuous carbon monitors because SVOM is lost from the collection media during sample collection. We have modified a Sunset Laboratory Carbon Aerosol Monitor to allow for the determination of SVOM. In a conventional Sunset monitor, gas-phase organic compounds are removed in the sampled airstream by a diffusion denuder employing charcoal-impregnated cellulose filter (CIF) surfaces. Subsequently, particles are collected on a quartz filter and the instrument then determines both the organic carbon and elemental carbon fractions of the aerosol using a thermal/optical method. However, some of the SVOM is lost from the filter during collection, and therefore is not determined. Because the interfering gas-phase organic compounds are removed before aerosol collection, the SVOM can be determined by filtering the particles at the instrument inlet and then replacing the quartz filter in the monitor with a charcoal-impregnated glass fiber filter (CIG), which retains the SVOM lost from particles collected on the inlet filter. The resulting collected SVOM is then determined in the analysis step by measurement of the carbonaceous material thermally evolved from the CIG filter. This concept was tested during field studies in February 2003 in Lindon, UT, and in July 2003 in Rubidoux, CA. The results obtained were validated by comparison with Particle Concentrator-Brigham Young University Organic Sampling System (PC-BOSS) results. The sum of nonvolatile organic material determined with a conventional Sunset monitor and SVOM determined with the modified Sunset monitor agree with the PC-BOSS results. Linear regression analysis of total carbon concentrations determined by the PC-BOSS and the Sunset resulted in a zero-intercept slope of 0.99 +/- 0.02 (R2 = 0.92) and a precision of sigma = +/- 1.5 microg C/m3 (8%).

  7. Assessing truck driver exposure at the World Trade Center disaster site: personal and area monitoring for particulate matter and volatile organic compounds during October 2001 and April 2002.

    Science.gov (United States)

    Geyh, Alison S; Chillrud, Steven; Williams, D'Ann L; Herbstman, Julie; Symons, J Morel; Rees, Katherine; Ross, James; Kim, Sung Roul; Lim, Ho-Jin; Turpin, Barbara; Breysse, Patrick

    2005-03-01

    The destruction of the World Trade Center (WTC) in New York City on September 11, 2001, created a 16-acre debris field composed of pulverized and burning material significantly impacting air quality. Site cleanup began almost immediately. Cleanup workers were potentially exposed to airborne contaminants, including particulate matter, volatile organic compounds, and asbestos, at elevated concentrations. This article presents the results of the exposure assessment of one important group of WTC workers, truck drivers, as well as area monitoring that was conducted directly on site during October 2001 and April 2002. In cooperation with a local labor union, 54 drivers (October) and 15 drivers (April) were recruited on site to wear two monitors during their 12-hour work shifts. In addition, drivers were administered a questionnaire asking for information ranging from "first day at the site" to respirator use. Area monitoring was conducted at four perimeter locations during October and three perimeter locations during April. During both months, monitoring was also conducted at one location in the middle of the rubble. Contaminants monitored for included total dust (TD), PM10, PM2.5, and volatile organic compounds. Particle samples were analyzed for mass, as well as elemental and organic carbon content. During October, the median personal exposure to TD was 346 microg/m3. The maximum area concentration, 1742 microg/m3, was found in middle of the debris. The maximum TD concentration found at the perimeter was 392 microg/m3 implying a strong concentration gradient from the middle of debris outward. PM2.5/PM10 ratios ranged from 23% to 100% suggesting significant fire activity during some of the sampled shifts. During April, the median personal exposure to TD was 144 microg/m3, and the highest area concentration, 195 microg/m3, was found at the perimeter. During both months, volatile organic compounds concentrations were low.

  8. Exposure to Particle Matters and Hazardous Volatile Organic Compounds in Selected Hot Spring Hotels in Guangdong, China

    Directory of Open Access Journals (Sweden)

    Qiusheng He

    2016-04-01

    Full Text Available In Guangdong province, many hot springs were exploited and developed into popular places for tourist. In addition, hotels have been set up near hot spring sites to attract people, including local citizens, to spend their spare time inside these so-called “spring hotels”. In our study, indoor air quality was investigated in four hot spring hotels in Guangdong province, China. Measured indoor pollutants included CO2, CO, PM10, PM2.5 and Volatile Organic Compounds (VOCs. As the result show, high concentrations of carbon dioxide might be attributed to poor ventilation; and the variations of indoor PM10, PM2.5 concentrations were related to occupants’ activities. Alpha-pinene and toluene were the most common VOC species in the hot spring hotels other than monocyclic aromatic hydrocarbons like Benzene, Toluene, Ethylbenzene and Xylenes (BTEX, which were at medium levels among the reported indoor pollutants. High cancer risk of benzene in the newly decorated rooms should be seriously taken into consideration in the future. Indoor to Outdoor air concentration ratios (I/O for CO2 and VOCs were higher than 1, indicating their strong indoor sources. Negative correlations were found between indoor CO2 and all the other compounds, and VOCs were shown to be significantly correlated (p < 0.01 to each other, including aromatic hydrocarbons and mono-terpenes. For indoor and outdoor air compounds, correlation coefficients among all compounds did not show a significant correlation, which indicated that these pollutants had different sources. Principal components analysis by SPSS showed that indoor materials, inhabitants’ activities and respiration, cleaning products and outdoor sources were the main sources of indoor detected pollutants in hot spring hotels.

  9. atmospheric volatile organic compounds

    Directory of Open Access Journals (Sweden)

    A. R. Koss

    2016-07-01

    organic compounds (VOCs that cannot be ionized with H3O+ ions (e.g., in a PTR-MS or H3O+ CIMS instrument. Here we describe the adaptation of a high-resolution time-of-flight H3O+ CIMS instrument to use NO+ primary ion chemistry. We evaluate the NO+ technique with respect to compound specificity, sensitivity, and VOC species measured compared to H3O+. The evaluation is established by a series of experiments including laboratory investigation using a gas-chromatography (GC interface, in situ measurement of urban air using a GC interface, and direct in situ measurement of urban air. The main findings are that (1 NO+ is useful for isomerically resolved measurements of carbonyl species; (2 NO+ can achieve sensitive detection of small (C4–C8 branched alkanes but is not unambiguous for most; and (3 compound-specific measurement of some alkanes, especially isopentane, methylpentane, and high-mass (C12–C15 n-alkanes, is possible with NO+. We also demonstrate fast in situ chemically specific measurements of C12 to C15 alkanes in ambient air.

  10. Volatile and semivolatile organic compounds in laboratory peat fire emissions

    Science.gov (United States)

    Speciated volatile organic compounds (VOCs) and organic fine particulate matter (PM2.5) mass emission factors were determined from laboratory peat fire experiments. Peat samples originated from two wildlife reserves located near the coast of North Carolina, U.S. Gas and particula...

  11. Characterisation of selected volatile organic compounds in ...

    African Journals Online (AJOL)

    kshale

    2013-05-15

    May 15, 2013 ... spectrometry. K. Shale1*, J. Mukamugema2, R. J. Lues1, P. Venter3 and K. K. Mokoena1 ..... Cajka T, Riddellova K, Tomaniova M, Hajslova J (2010). Recognition of ... volatile organic compounds of coniferous needle litter.

  12. Is old organic matter simple organic matter?

    Science.gov (United States)

    Nunan, Naoise; Lerch, Thomas; Pouteau, Valérie; Mora, Philippe; Changey, Fréderique; Kätterer, Thomas; Herrmann, Anke

    2016-04-01

    Bare fallow soils that have been deprived of fresh carbon inputs for prolonged periods contain mostly old, stable organic carbon. In order to shed light on the nature of this carbon, the functional diversity profiles (MicroResp™, Biolog™ and enzyme activity spectra) of the microbial communities of long-term barefallow soils were analysed and compared with those of the microbial communities from their cultivated counterparts. The study was based on the idea that microbial communities adapt to their environment and that therefore the catabolic and enzymatic profiles would reflect the type of substrates available to the microbial communities. The catabolic profiles suggested that the microbial communities in the long-term bare-fallow soil were exposed to a less diverse range of substrates and that these substrates tended to be of simpler molecular forms. Both the catabolic and enzyme activity profiles suggested that the microbial communities from the long-term bare-fallow soils were less adapted to using polymers. These results do not fit with the traditional view of old, stable carbon being composed of complex, recalcitrant polymers. An energetics analysis of the substrate use of the microbial communities for the different soils suggested that the microbial communities from the long-term bare-fallow soils were better adapted to using readily oxidizable,although energetically less rewarding, substrates. Microbial communities appear to adapt to the deprivation of fresh organic matter by using substrates that require little investment.

  13. Factors affecting the volatilization of volatile organic compounds from wastewater

    Directory of Open Access Journals (Sweden)

    Junya Intamanee

    2006-09-01

    Full Text Available This study aimed to understand the influence of the wind speed (U10cm, water depth (h and suspended solids (SS on mass transfer coefficient (KOLa of volatile organic compounds (VOCs volatilized from wastewater. The novelty of this work is not the method used to determine KOLa but rather the use of actual wastewater instead of pure water as previously reported. The influence of U10cm, h, and SS on KOLa was performed using a volatilization tank with the volume of 100-350 L. Methyl Ethyl Ketone (MEK was selected as a representative of VOCs investigated here in. The results revealed that the relationship between KOLa and the wind speeds falls into two regimes with a break at the wind speed of 2.4 m/s. At U10cm 2.4 m/s, KOLa increased more rapidly. The relationship between KOLa and U10cm was also linear but has a distinctly higher slope. For the KOLa dependency on water depth, the KOLa decreased significantly with increasing water depth up to a certain water depth after that the increase in water depth had small effect on KOLa. The suspended solids in wastewater also played an important role on KOLa. Increased SS resulted in a significant reduction of KOLa over the investigated range of SS. Finally, the comparison between KOLa obtained from wastewater and that of pure water revealed that KOLa from wastewater were much lower than that of pure water which was pronounced at high wind speed and at small water depth. This was due the presence of organic mass in wastewater which provided a barrier to mass transfer and reduced the degree of turbulence in the water body resulting in low volatilization rate and thus KOLa. From these results, the mass transfer model for predicting VOCs emission from wastewater should be developed based on the volatilization of VOCs from wastewater rather than that from pure water.

  14. Volatile halocarbons emissions through interaction of saltwater intrusion and terrestrial organic matter along a salinity gradient in coastal southeastern United States

    Science.gov (United States)

    Jiao, Y.; Wang, J. J.; Chow, A. T.; Rhew, R. C.

    2015-12-01

    Freshwater wetlands along the coast of southeastern United States can be subjected to inputs of halogens from seawater intrusion following long-term sea level rise. The interaction of halogens with organic-rich sediments can lead to the formation of organohalogens. In this study, we report field and laboratory emission rates of volatile halocarbons (methyl halides and chloroform) along a salinity gradient in coastal South Carolina, including freshwater forest, degraded oligohaline forest, and salt marsh. For chloroform, the oligohaline (intermediate) forest showed the largest mean emissions, compared to the freshwater forest and mesohaline saltmarsh. Soil cores were measured intact live, spread out live, intact dead, and spread out dead. Interestingly, the dead soil and live soil incubations showed no statistical difference in chloroform emissions, suggesting that their formation is predominately abiotic. For methyl chloride and methyl bromide, saltmarsh soils were sources while freshwater forest and degraded oligohaline forest soils were sinks. Sterilization of soils caused emissions rates to be higher, even converting sinks to sources, suggesting that live microorganisms and enzymes in the soils were sinks for the methyl halides, thereby masking the abiotic production rates. The simultaneous production and consumption of methyl halides in these soils is consistent with prior studies investigating the bidirectional fluxes of these compounds. Our study indicates that long-term sea level rise that turns freshwater forest wetlands to degraded forest wetlands or saltmarsh can significantly change the halocarbon biogeochemistry in southeastern United States.

  15. Volatile organic compound emissions from silage systems

    Science.gov (United States)

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

  16. What to do with volatile organic matter in the next century?; Wat doen we met vluchtige organische stoffen in de volgende eeuw?

    Energy Technology Data Exchange (ETDEWEB)

    Hofmeijer, P.L. [Ministerie van Volkshuisvesting, Ruimtelijke Ordening en Milieubeheer VROM, The Hague (Netherlands)

    1999-08-01

    Until the year 2001 the emission of volatile organic carbons in the Netherlands from stationary sources and products will be dealt with by the KWS 2000-covenant. In this covenant the Dutch authorities and industry agreed upon taking about 100 VOC-reducing measures. This approach was successful; we expect to reach our 2001-target: a VOC-reduction of about 50% (against 1981). However, in the future, the Netherlands has to realize more VOC-emission reduction in order to reduce exposure to high concentrations of tropospheric ozone. The Netherlands are still facing large emissions of VOC due to its population density, traffic and industrial activity, and because its neighbouring countries are facing similar problems. On top of that, there is new research indicating that long, direct exposure to VOC can cause health problems, e.g. neuro-toxic disease, infertility and hearing problems. Reasons enough to start a VOC-reduction possibility study in cooperation with the Dutch industry. After it is clear which VOC-reduction measures can be taken under what conditions and at which costs, we will try to reach an agreement on a new, post-2000 VOC-policy. It is clear however, that a large part of the VOC-emission in the Netherlands (excluding mobile sources and incineration) is from solvents in a limited number of products, e.g. paint, hair sprays and cleaning agents. That`s why the Netherlands insists on guidelines of the European Committee for VOC-containing products, in order to limit the amount of VOC per product drastically

  17. What to do with volatile organic matter in the next century?; Wat doen we met vluchtige organische stoffen in de volgende eeuw?

    Energy Technology Data Exchange (ETDEWEB)

    Hofmeijer, P.L. [Ministerie van Volkshuisvesting, Ruimtelijke Ordening en Milieubeheer VROM, The Hague (Netherlands)

    1999-08-01

    Until the year 2001 the emission of volatile organic carbons in the Netherlands from stationary sources and products will be dealt with by the KWS 2000-covenant. In this covenant the Dutch authorities and industry agreed upon taking about 100 VOC-reducing measures. This approach was successful; we expect to reach our 2001-target: a VOC-reduction of about 50% (against 1981). However, in the future, the Netherlands has to realize more VOC-emission reduction in order to reduce exposure to high concentrations of tropospheric ozone. The Netherlands are still facing large emissions of VOC due to its population density, traffic and industrial activity, and because its neighbouring countries are facing similar problems. On top of that, there is new research indicating that long, direct exposure to VOC can cause health problems, e.g. neuro-toxic disease, infertility and hearing problems. Reasons enough to start a VOC-reduction possibility study in cooperation with the Dutch industry. After it is clear which VOC-reduction measures can be taken under what conditions and at which costs, we will try to reach an agreement on a new, post-2000 VOC-policy. It is clear however, that a large part of the VOC-emission in the Netherlands (excluding mobile sources and incineration) is from solvents in a limited number of products, e.g. paint, hair sprays and cleaning agents. That's why the Netherlands insists on guidelines of the European Committee for VOC-containing products, in order to limit the amount of VOC per product drastically.

  18. Volatile Organic Compounds are Ghosts for Organic Solar Cells

    Directory of Open Access Journals (Sweden)

    Prakash R. Somani

    2014-11-01

    Full Text Available All our efforts to demonstrate a multifunctional device – photovoltaic gas sensor (i.e. solar cell which show photovoltaic action depending on the gas / volatile organic compounds (VOC in the surrounding atmosphere yielded negative results. Photovoltaic performance of the organic solar cells under study degraded – almost permanently by exposing them to volatile organic compounds (VOCs. Although, the proposed multifunctional device could not be demonstrated; Present investigations yielded very important result that organic solar cells have problems not only with oxygen and humidity (known facts but also with many VOCs and hazardous gases – making lamination / encapsulation step mandatory for their practical utilization.

  19. Organic Matter Management

    Energy Technology Data Exchange (ETDEWEB)

    Izaurralde, Roberto C.; Cerri, Carlos C.

    2002-01-01

    Soil organic matter (S)M) is an essential attribute of soil quality with a key role in soil conservation and sustainable agriculture. Many practices-some involving land use changes-have been shown to increase SOM and thus received considerable attention for their possible role in climate change mitigation. Carbon sequestration in managed soils occurs when there is a net removal of atmospheric CO2 because of the balance between carbon inputs (net primary productivity) and outputs (soil respiration, management-related C emissions). Soil C sequestration has the additional appeal that all its practices conform to principles of sustainable agriculture (e.g., reduced tillage, erosion control, diverse cropping systems, improved soil fertility). Long-term field experiments have been instrumental to increase our understanding of SOM dynamics. This chapter presents fundamental concepts to guide readers on the role of SOM in sustainable agriculture and climate change mitigation.

  20. Arctic River organic matter transport

    Science.gov (United States)

    Raymond, Peter; Gustafsson, Orjan; Vonk, Jorien; Spencer, Robert; McClelland, Jim

    2016-04-01

    Arctic Rivers have unique hydrology and biogeochemistry. They also have a large impact on the Arctic Ocean due to the large amount of riverine inflow and small ocean volume. With respect to organic matter, their influence is magnified by the large stores of soil carbon and distinct soil hydrology. Here we present a recap of what is known of Arctic River organic matter transport. We will present a summary of what is known of the ages and sources of Arctic River dissolved and particulate organic matter. We will also discuss the current status of what is known about changes in riverine organic matter export due to global change.

  1. Dissolved Organic Matter in Freshwaters

    Science.gov (United States)

    Perdue, E. M.; Ritchie, J. D.

    2003-12-01

    Organic matter in freshwaters exists as dissolved molecules, colloids, and particles. It is appropriate to regard these distinctions as dynamic, however, because organic matter can be interconverted readily between these forms by dissolution and precipitation, sorption and desorption, aggregation and disaggregation, etc. Dissolved organic matter (DOM), the subject of this chapter, is defined operationally as the fraction of organic matter in a water sample that passes through a 0.45 μm filter. In the authors' opinion, the scientific literature on organic matter in freshwaters will be better reflected in this review, if data are considered without regard to the manner in which water samples may have been filtered. This more general approach is warranted because: * many submicron colloids and some microorganisms can pass through 0.45 μm filters; * the effective pore size of a 0.45 μm filter is usually unknown, because it is decreased by partial clogging during the filtration of a water sample; * some important studies have been conducted on unfiltered samples or on samples that were filtered through other types of filters; and * some important studies have been conducted on samples that were concentrated with ultrafiltration (UF), nanofiltration (NF), or reverse osmosis (RO) membranes.As methods for fractionation and isolation of organic matter in freshwaters have evolved, and as the intensity of research has waxed and waned in various academic disciplines, a rich and potentially confusing nomenclature has evolved for organic matter in freshwaters. Some of the more commonly encountered descriptors and their associated acronyms, if any, are yellow organic acids (YOAs), aquatic humus, DOM, and natural organic matter (NOM). Regardless of the terminology used in the original literature, the organic matter in freshwaters is referred to as DOM in this review, except when it is necessary to be more specific.

  2. TMVOC, simulator for multiple volatile organic chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Pruess, Karsten; Battistelli, Alfredo

    2003-03-25

    TMVOC is a numerical simulator for three-phase non-isothermal flow of water, soil gas, and a multicomponent mixture of volatile organic chemicals (VOCs) in multidimensional heterogeneous porous media. It is an extension of the TOUGH2 general-purpose simulation program developed at the Lawrence Berkeley National Laboratory. TMVOC is designed for applications to contamination problems that involve hydrocarbon fuel or organic solvent spills in saturated and unsaturated zones. It can model contaminant behavior under ''natural'' environmental conditions, as well as for engineered systems, such as soil vapor extraction, groundwater pumping, or steam-assisted source remediation. TMVOC is upwards compatible with T2VOC (Falta et al., 1995) and can be initialized from T2VOC-style initial conditions. The main enhancements in TMVOC relative to T2VOC are as follows: a multicomponent mixture of volatile organic chemicals can be modeled; any and all combinations of the three phases water-oil-gas are treated; several non-condensible gases may be present; diffusion is treated in all phases in a manner that is fully coupled with phase partitioning. This paper gives a brief summary of the methodology used in TMVOC as well as highlighting some implementation issues. Simulation of a NAPL spill and subsequent remediation is discussed for a 2-D vertical section of a saturated-unsaturated flow problem.

  3. Making organization research matter

    DEFF Research Database (Denmark)

    Flyvbjerg, Bent

    2006-01-01

    research or any of the social sciences. Second, we must address problems that matter to groups in the local, national, and global communities in which we live, and we must do it in ways that matter; we must focus on issues of context, values, and power, as advocated by great social scientists from...... Aristotle and Machiavelli to Max Weber and Pierre Bourdieu. Finally, we must effectively and dialogically communicate the results of our research to our fellow citizens and carefully listen to their feedback. If we do this – focus on specific values and interests in the context of particular power relations...

  4. The destruction of organic matter

    CERN Document Server

    Gorsuch, T T

    1970-01-01

    International Series of Monographs in Analytical Chemistry, Volume 39: The Destruction of Organic Matter focuses on the identification of trace elements in organic compounds. The monograph first offers information on the processes involved in the determination of trace elements in organic matters, as well as the methods not involving complete destruction of these elements. The text surveys the sources of errors in the processes responsible in pinpointing elements in organic compounds. These processes include sampling, disruption of the samples, manipulation, and measurements. The book

  5. Temperature-induced volatility of molecular markers in ambient airborne particulate matter

    Directory of Open Access Journals (Sweden)

    C. R. Ruehl

    2010-08-01

    Full Text Available Molecular markers are organic compounds used to represent known sources of particulate matter (PM in statistical source apportionment studies. The utility of molecular markers depends on, among other things, their ability to represent PM volatility under realistic atmospheric conditions. We measured the particle-phase concentrations and temperature-induced volatility of commonly-used molecular markers in California's heavily polluted San Joaqin Valley. Concentrations of elemental carbon, organic carbon, levoglucosan, and polycyclic aromatic hydrocarbons were not reduced by mild (~10 K heating. In contrast, both hopane/sterane and n-alkane concentrations were reduced, especially during the summer sampling events at the urban site. These results suggest that hopanes and steranes have effective saturation concentrations ~1 μg m−3, and therefore can be considered semi-volatile in realistic ambient conditions. The volatility behavior of n-alkanes during the urban summer is consistent with that predicted for absorption by suberic acid (a C8 diacid using a group contribution modelling method. Observations can also be matched by an absorbent whose composition is based on recently-obtained high-resolution aerosol mass spectrometer factors (approximately 33% "hydrocarbon-like" and 67% oxygenated organic aerosol. The diminished volatility of the n-alkanes, hopanes, and steranes during rural and/or winter experiments could be explained by a more oxygenated absorbing phase along with a non-absorptive partitioning mechanism, such as adsorption to soot. This suggests that the temperature-induced volatility of large hydrocarbons in PM is most important if a relatively non-polar absorbing organic phase exists. While the activity coefficients of most organic aerosol compounds may be close to unity, the assumption of ideality for large hydrocarbons (e.g., hopanes may result in large errors in partitioning calculations.

  6. Organic matter in meteorites.

    Science.gov (United States)

    Llorca, Jordi

    2004-12-01

    Some primitive meteorites are carbon-rich objects containing a variety of organic molecules that constitute a valuable record of organic chemical evolution in the universe prior to the appearance of microorganisms. Families of compounds include hydrocarbons, alcohols, aldehydes, ketones, carboxylic acids, amino acids, amines, amides, heterocycles, phosphonic acids, sulfonic acids, sugar-related compounds and poorly defined high-molecular weight macromolecules. A variety of environments are required in order to explain this organic inventory, including interstellar processes, gas-grain reactions operating in the solar nebula, and hydrothermal alteration of parent bodies. Most likely, substantial amounts of such organic materials were delivered to the Earth via a late accretion, thereby providing organic compounds important for the emergence of life itself, or that served as a feedstock for further chemical evolution. This review discusses the organic content of primitive meteorites and their relevance to the build up of biomolecules.

  7. FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

    Energy Technology Data Exchange (ETDEWEB)

    John F. Schabron; Joseph F. Rovani Jr.; Theresa M. Bomstad

    2002-06-01

    Western Research Institute (WRI) initiated exploratory work towards the development of new field screening methodology and a test kit to measure halogenated volatile organic compounds (VOCs) in the field. Heated diode and corona discharge sensors are commonly used to detect leaks of refrigerants from air conditioners, freezers, and refrigerators. They are both selective to the presence of carbon-halogen bonds. Commercially available heated diode and corona discharge leak detectors were procured and evaluated for halogenated VOC response. The units were modified to provide a digital readout of signal related to VOC concentration. Sensor response was evaluated with carbon tetrachloride and tetrachloroethylene (perchloroethylene, PCE), which represent halogenated VOCs with and without double bonds. The response characteristics were determined for the VOCs directly in headspace in Tedlar bag containers. Quantitation limits in air were estimated. Potential interferences from volatile hydrocarbons, such as toluene and heptane, were evaluated. The effect of humidity was studied also. The performance of the new devices was evaluated in the laboratory by spiking soil samples and monitoring headspace for halogenated VOCs. A draft concept of the steps for a new analytical method was outlined. The results of the first year effort show that both devices show potential utility for future analytical method development work towards the goal of developing a portable test kit for screening halogenated VOCs in the field.

  8. Feed and organic matter

    DEFF Research Database (Denmark)

    Dalsgaard, Anne Johanne Tang

    2011-01-01

    Organic waste from fish production is conventionally measured as BOD5 (biological oxygen demand measured during 5 days) and COD (chemical oxygen demand (includes BOD5)). Organic waste is of particular concern for several reasons. The easily degradable part (BOD5) may have an immediate, negative...... impact on the receiving water body by reducing dissolved oxygen concentrations and increasing sedimentation. Within aquaculture systems, a high organic load may affect fish health and performance directly (e.g., gill disease) as well as indirectly (proliferation of pathogenic bacteria and parasites......, reduction of dissolved oxygen concentrations, etc.). In recirculating aquaculture systems (RAS), a high organic load caused by limited water exchange may affect biofilter performance by favouring heterotrophic bacteria at the expense of autotrophic, nitrifying bacteria. Organic waste in RAS primarily...

  9. Volatile organic compound detection using nanostructured copolymers.

    Science.gov (United States)

    Li, Bo; Sauvé, Genevieve; Iovu, Mihaela C; Jeffries-El, Malika; Zhang, Rui; Cooper, Jessica; Santhanam, Suresh; Schultz, Lawrence; Revelli, Joseph C; Kusne, Aaron G; Kowalewski, Tomasz; Snyder, Jay L; Weiss, Lee E; Fedder, Gary K; McCullough, Richard D; Lambeth, David N

    2006-08-01

    Regioregular polythiophene-based conductive copolymers with highly crystalline nanostructures are shown to hold considerable promise as the active layer in volatile organic compound (VOC) chemresistor sensors. While the regioregular polythiophene polymer chain provides a charge conduction path, its chemical sensing selectivity and sensitivity can be altered either by incorporating a second polymer to form a block copolymer or by making a random copolymer of polythiophene with different alkyl side chains. The copolymers were exposed to a variety of VOC vapors, and the electrical conductivity of these copolymers increased or decreased depending upon the polymer composition and the specific analytes. Measurements were made at room temperature, and the responses were found to be fast and appeared to be completely reversible. Using various copolymers of polythiophene in a sensor array can provide much better discrimination to various analytes than existing solid state sensors. Our data strongly indicate that several sensing mechanisms are at play simultaneously, and we briefly discuss some of them.

  10. 40 CFR 60.462 - Standards for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

    ... Coil Surface Coating § 60.462 Standards for volatile organic compounds. (a) On and after the date on... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for volatile organic compounds. 60.462 Section 60.462 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  11. 40 CFR 60.542 - Standards for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

    ... Rubber Tire Manufacturing Industry § 60.542 Standards for volatile organic compounds. (a) On and after... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for volatile organic compounds. 60.542 Section 60.542 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  12. 40 CFR 60.442 - Standard for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds... Pressure Sensitive Tape and Label Surface Coating Operations § 60.442 Standard for volatile organic compounds. (a) On and after the date on which the performance test required by § 60.8 has been...

  13. 40 CFR 60.622 - Standards for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

    ... Petroleum Dry Cleaners § 60.622 Standards for volatile organic compounds. (a) Each affected petroleum... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for volatile organic compounds. 60.622 Section 60.622 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  14. 40 CFR 60.582 - Standard for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds. 60.582 Section 60.582 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Flexible Vinyl and Urethane Coating and Printing § 60.582 Standard for volatile organic compounds. (a)...

  15. 40 CFR 60.712 - Standards for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

    ... Magnetic Tape Coating Facilities § 60.712 Standards for volatile organic compounds. Each owner or operator... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for volatile organic compounds. 60.712 Section 60.712 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  16. 40 CFR 60.432 - Standard for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds. 60.432 Section 60.432 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Graphic Arts Industry: Publication Rotogravure Printing § 60.432 Standard for volatile organic...

  17. 40 CFR 60.492 - Standards for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

    ... Beverage Can Surface Coating Industry § 60.492 Standards for volatile organic compounds. On or after the... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for volatile organic compounds. 60.492 Section 60.492 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  18. 40 CFR 60.392 - Standards for volatile organic compounds

    Science.gov (United States)

    2010-07-01

    ... Automobile and Light Duty Truck Surface Coating Operations § 60.392 Standards for volatile organic compounds... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for volatile organic compounds 60.392 Section 60.392 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  19. 40 CFR 60.722 - Standards for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

    ... volatile organic compounds. (a) Each owner or operator of any affected facility which is subject to the... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for volatile organic compounds. 60.722 Section 60.722 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  20. 40 CFR 60.452 - Standard for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds. 60.452 Section 60.452 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Industrial Surface Coating: Large Appliances § 60.452 Standard for volatile organic compounds. On or...

  1. 40 CFR 60.602 - Standard for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds. 60.602 Section 60.602 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Synthetic Fiber Production Facilities § 60.602 Standard for volatile organic compounds. On and after...

  2. 40 CFR 60.742 - Standards for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

    ... Polymeric Coating of Supporting Substrates Facilities § 60.742 Standards for volatile organic compounds. (a... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for volatile organic compounds. 60.742 Section 60.742 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  3. BIOCONCENTRATION FACTORS FOR VOLATILE ORGANIC COMPOUNDS IN VEGETATION

    Science.gov (United States)

    Samples of air and leaves were taken at the University of Nevada-Las Vegas campus and analyzed for volatile organic compounds using vacuum distillation coupled with gas chromatography/mass spectrometry. The data were used to estimate the bioconcentration of volatile organic compo...

  4. Radionuclide - Soil Organic Matter Interactions

    DEFF Research Database (Denmark)

    Carlsen, Lars

    1985-01-01

    Interactions between soil organic matter, i.e. humic and fulvic acids, and radionuclides of primary interest to shallow land burial of low activity solid waste have been reviewed and to some extent studied experimentally. The radionuclides considered in the present study comprise cesium, strontium...

  5. Volatile organic compound remedial action project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1991-12-01

    This Environmental Assessment (EA) reviews a proposed project that is planned to reduce the levels of volatile organic compound (VOC) contaminants present in the Mound domestic water supply. The potable and industrial process water supply for Mound is presently obtained from a shallow aquifer via on-site production wells. The present levels of VOCs in the water supply drawn from the on-site wells are below the maximum contaminant levels (MCLs) permissible for drinking water under Safe Drinking Water Act (SDWA; 40 CFR 141); however, Mound has determined that remedial measures should be taken to further reduce the VOC levels. The proposed project action is the reduction of the VOC levels in the water supply using packed tower aeration (PTA). This document is intended to satisfy the requirements of the National Environmental Policy Act (NEPA) of 1969 and associated Council on Environmental Quality regulations (40 CFR parts 1500 through 1508) as implemented through U.S. Department of Energy (DOE) Order 5440.1D and supporting DOE NEPA Guidelines (52 FR 47662), as amended (54 FR 12474; 55 FR 37174), and as modified by the Secretary of Energy Notice (SEN) 15-90 and associated guidance. As required, this EA provides sufficient information on the probable environmental impacts of the proposed action and alternatives to support a DOE decision either to prepare an Environmental Impact Statement (EIS) or issue a Finding of No Significant Impact (FONSI).

  6. Volatile Organic Compound Analysis in Istanbul

    Science.gov (United States)

    Ćapraz, Ö.; Deniz, A.; Öztürk, A.; Incecik, S.; Toros, H.; Coşkun, M.

    2012-04-01

    Volatile Organic Compound Analysis in Istanbul Ö. Çapraz1, A. Deniz1,3, A. Ozturk2, S. Incecik1, H. Toros1 and, M. Coskun1 (1) Istanbul Technical University, Faculty of Aeronautics and Astronautics, Department of Meteorology, 34469, Maslak, Istanbul, Turkey. (2) Istanbul Technical University, Faculty of Chemical and Metallurgical, Chemical Engineering, 34469, Maslak, Istanbul, Turkey. (3) Marmara Clean Air Center, Ministry of Environment and Urbanization, Nişantaşı, 34365, İstanbul, Turkey. One of the major problems of megacities is air pollution. Therefore, investigations of air quality are increasing and supported by many institutions in recent years. Air pollution in Istanbul contains many components that originate from a wide range of industrial, heating, motor vehicle, and natural emissions sources. VOC, originating mainly from automobile exhaust, secondhand smoke and building materials, are one of these compounds containing some thousands of chemicals. In spite of the risks to human health, relatively little is known about the levels of VOC in Istanbul. In this study, ambient air quality measurements of 32 VOCs including hydrocarbons, halogenated hydrocarbons and carbonyls were conducted in Kağıthane (Golden Horn) region in Istanbul during the winter season of 2011 in order to develop the necessary scientific framework for the subsequent developments. Kağıthane creek valley is the source part of the Golden Horn and one of the most polluted locations in Istanbul due to its topographical form and pollutant sources in the region. In this valley, horizontal and vertical atmospheric motions are very weak. The target compounds most commonly found were benzene, toluene, xylene and ethyl benzene. Concentrations of total hydrocarbons ranged between 1.0 and 10.0 parts per billion, by volume (ppbv). Ambient air levels of halogenated hydrocarbons appeared to exhibit unique spatial variations and no single factor seemed to explain trends for this group of

  7. Measurement of volatile organic compounds inside automobiles.

    Science.gov (United States)

    Fedoruk, Marion J; Kerger, Brent D

    2003-01-01

    The objective of the current study was to evaluate the types and concentrations of volatile organic compounds (VOCs) in the passenger cabin of selected sedan automobiles under static (parked, unventilated) and specified conditions of operation (i.e., driving the vehicle using air conditioning alone, vent mode alone, or driver's window half open). Data were collected on five different passenger sedan vehicles from three major automobile manufacturers. Airborne concentrations were assessed using 90-min time-weighted average (TWA) samples under U.S. Environmental Protection Agency (USEPA) Method IP-1B to assess individual VOC compounds and total VOCs (TVOCs) calibrated to toluene. Static vehicle testing demonstrated TVOC levels of approximately 400-800 microg/m(3) at warm interior vehicle temperatures (approximately 80 degrees F), whereas TVOCs at least fivefold higher were observed under extreme heat conditions (e.g., up to 145 degrees F). The profile of most prevalent individual VOC compounds varied considerably according to vehicle brand, age, and interior temperature tested, with predominant compounds including styrene, toluene, and 8- to 12-carbon VOCs. TVOC levels under varied operating conditions (and ventilation) were generally four- to eightfold lower (at approximately 50-160 microg/m(3)) than the static vehicle measurements under warm conditions, with the lowest measured levels generally observed in the trials with the driver's window half open. These data indicate that while relatively high concentrations of certain VOCs can be measured inside static vehicles under extreme heat conditions, normal modes of operation rapidly reduce the inside-vehicle VOC concentrations even when the air conditioning is set on recirculation mode.

  8. Organic matter in the universe

    CERN Document Server

    Kwok, Sun

    2012-01-01

    Authored by an experienced writer and a well-known researcher of stellar evolution, interstellar matter and spectroscopy, this unique treatise on the formation and observation of organic compounds in space includes a spectroscopy refresher, as well as links to geological findings and finishes with the outlook for future astronomical facilities and solar system exploration missions. A whole section on laboratory simulations includes the Miller-Urey experiment and the ultraviolet photolysis of ices.

  9. Measuring the atmospheric organic aerosol volatility distribution: a theoretical analysis

    Directory of Open Access Journals (Sweden)

    E. Karnezi

    2014-01-01

    Full Text Available Organic compounds represent a significant fraction of submicrometer atmospheric aerosol mass. Even if most of these compounds are semi-volatile in atmospheric concentrations, the ambient organic aerosol volatility is quite uncertain. The most common volatility measurement method relies on the use of a thermodenuder (TD. The aerosol passes through a heated tube where its more volatile components evaporate leaving the less volatile behind in the particulate phase. The typical result of a~thermodenuder measurement is the mass fraction remaining (MFR, which depends among other factors on the organic aerosol (OA vaporization enthalpy and the accommodation coefficient. We use a new method combining forward modeling, introduction of "experimental" error and inverse modeling with error minimization for the interpretation of TD measurements. The OA volatility distribution, its effective vaporization enthalpy, the mass accommodation coefficient and the corresponding uncertainty ranges are calculated. Our results indicate that existing TD-based approaches quite often cannot estimate reliably the OA volatility distribution, leading to large uncertainties, since there are many different combinations of the three properties that can lead to similar thermograms. We propose an improved experimental approach combining TD and isothermal dilution measurements. We evaluate this experimental approach using the same model and show that it is suitable for studies of OA volatility in the lab and the field.

  10. Biogenic volatile organic compounds - small is beautiful

    Science.gov (United States)

    Owen, S. M.; Asensio, D.; Li, Q.; Penuelas, J.

    2012-12-01

    While canopy and regional scale flux measurements of biogenic volatile organic compounds (bVOCs) are essential to obtain an integrated picture of total compound reaching the atmosphere, many fascinating and important emission details are waiting to be discovered at smaller scales, in different ecological and functional compartments. We concentrate on bVOCs below ground to allelopathy. A gradient of monoterpene concentration was found in soil around Pinus sylvestris and Pinus halepensis, decreasing with distance from the tree. Some compounds (α-pinene, sabinene, humulene and caryophyllene) in mineral soil were linearly correlated with the total amount of each compound in the overlying litter, indicating that litter might be the dominant source of these compounds. However, α-pinene did not fall within the correlation, indicating a source other than litter, probably root exudates. We also show that rhizosphere bVOCs can be a carbon source for soil microbes. In a horizontal gradient from Populus tremula trees, microbes closest to the tree trunk were better enzymatically equipped to metabolise labeled monoterpene substrate. Monoterpenes can also increase the degradation rate in soil of the persistant organic pollutants, likely acting as analogues for the cometabo-lism of polychlorinated biphenyls (PCBs) Flowers of a ginger species (Alpinia kwangsiensis) and a fig species (Ficus hispida) showed different bVOC signals pre- and post pollination. For Ficus hispida, there are three floral stages of a fig-wasp dependency mechanism: receptive, post pollinator and interfloral. Of 28 compounds detected, transcaryophyllene with trans-β-farnesene were the most important at the receptor stage, trans-caryophyllene was the most abundant at the post-pollinator stage, and isoprene was the most abundant in the interfloral stage. Alpinia kwangsiensis presents two morphologies for the reproductive parts of the flower. The "anaflexistyle" morphology has the flower style lowered in the

  11. Volatile and semivolatile organic compounds in laboratory peat fire emissions

    Data.gov (United States)

    U.S. Environmental Protection Agency — Supporting information Tables S3 and S4 list emission factors in g/kg of speciated volatile and particulate organic compounds emitted from peat burning. Peat samples...

  12. Temperature-induced volatility of molecular markers in ambient airborne particulate matter

    Directory of Open Access Journals (Sweden)

    C. R. Ruehl

    2011-01-01

    Full Text Available Molecular markers are organic compounds used to represent known sources of particulate matter (PM in statistical source apportionment studies. The utility of molecular markers depends on, among other things, their ability to represent PM volatility under realistic atmospheric conditions. We measured the particle-phase concentrations and temperature-induced volatility of commonly-used molecular markers in California's heavily polluted San Joaqin Valley. Concentrations of elemental carbon, organic carbon, levoglucosan, and polycyclic aromatic hydrocarbons were not reduced by mild (~10 K heating. In contrast, both hopane/sterane and n-alkane concentrations were reduced, especially during the summer sampling events at the urban site. These results suggest that hopanes and steranes have effective saturation concentrations ~1 μg m−3, and therefore can be considered semi-volatile. The volatility of an individual compound depends both on its inherent properties (primarily vapour pressure and the interactions between itself and any potential absorbing phase. The volatility behavior of n-alkanes during the urban summer is consistent with that predicted for absorption by suberic acid (a C8 diacid using a group contribution modelling method. Observations can also be matched by an absorbent whose composition is based on recently-obtained high-resolution aerosol mass spectrometer factors (approximately 33% "hydrocarbon-like" and 67% oxygenated organic aerosol. The reduced evaporation of the n-alkanes, hopanes, and steranes with mild heating during rural and/or winter experiments could be explained by a more oxygenated absorbing phase along with a non-absorptive partitioning mechanism, such as adsorption to soot. This suggests that the temperature-induced volatility of large hydrocarbons in PM is most important if a relatively non-polar absorbing organic phase exists. While the activity coefficients of most organic

  13. Total volatile organic compounds (TVOC) in indoor air quality investigations

    DEFF Research Database (Denmark)

    Mølhave, L.; Clausen, Geo; Berglund, B.

    1997-01-01

    The amount of volatile organic compounds (VOCs) in indoor air, usually called TVOC (total volatile organic compounds), has been measured using different definitions and techniques which yield different results. This report recommends a definition of TVOC referring to a specified range of VOCs...... for characterizing indoor pollution and for improving source control as required from the points of view of health, comfort, energy efficiency and sustainability. (C) Indoor Air (1997)....

  14. MATRIX-VBS (v1.0): implementing an evolving organic aerosol volatility in an aerosol microphysics model

    Science.gov (United States)

    Gao, Chloe Y.; Tsigaridis, Kostas; Bauer, Susanne E.

    2017-02-01

    The gas-particle partitioning and chemical aging of semi-volatile organic aerosol are presented in a newly developed box model scheme, where its effect on the growth, composition, and mixing state of particles is examined. The volatility-basis set (VBS) framework is implemented into the aerosol microphysical scheme MATRIX (Multiconfiguration Aerosol TRacker of mIXing state), which resolves mass and number aerosol concentrations and in multiple mixing-state classes. The new scheme, MATRIX-VBS, has the potential to significantly advance the representation of organic aerosols in Earth system models by improving upon the conventional representation as non-volatile particulate organic matter, often also with an assumed fixed size distribution. We present results from idealized cases representing Beijing, Mexico City, a Finnish forest, and a southeastern US forest, and investigate the evolution of mass concentrations and volatility distributions for organic species across the gas and particle phases, as well as assessing their mixing state among aerosol populations. Emitted semi-volatile primary organic aerosols evaporate almost completely in the intermediate-volatility range, while they remain in the particle phase in the low-volatility range. Their volatility distribution at any point in time depends on the applied emission factors, oxidation by OH radicals, and temperature. We also compare against parallel simulations with the original scheme, which represented only the particulate and non-volatile component of the organic aerosol, examining how differently the condensed-phase organic matter is distributed across the mixing states in the model. The results demonstrate the importance of representing organic aerosol as a semi-volatile aerosol, and explicitly calculating the partitioning of organic species between the gas and particulate phases.

  15. MATRIX-VBS (v1.0): Implementing an Evolving Organic Aerosol Volatility in an Aerosol Microphysics Model

    Science.gov (United States)

    Gao, Chloe Y.; Tsigaridis, Kostas; Bauer, Susanne E.

    2017-01-01

    The gas-particle partitioning and chemical aging of semi-volatile organic aerosol are presented in a newly developed box model scheme, where its effect on the growth, composition, and mixing state of particles is examined. The volatility-basis set (VBS) framework is implemented into the aerosol microphysical scheme MATRIX (Multiconfiguration Aerosol TRacker of mIXing state), which resolves mass and number aerosol concentrations and in multiple mixing-state classes. The new scheme, MATRIX-VBS, has the potential to significantly advance the representation of organic aerosols in Earth system models by improving upon the conventional representation as non-volatile particulate organic matter, often also with an assumed fixed size distribution. We present results from idealized cases representing Beijing, Mexico City, a Finnish forest, and a southeastern US forest, and investigate the evolution of mass concentrations and volatility distributions for organic species across the gas and particle phases, as well as assessing their mixing state among aerosol populations. Emitted semi-volatile primary organic aerosols evaporate almost completely in the intermediate-volatility range, while they remain in the particle phase in the low-volatility range. Their volatility distribution at any point in time depends on the applied emission factors, oxidation by OH radicals, and temperature. We also compare against parallel simulations with the original scheme, which represented only the particulate and non-volatile component of the organic aerosol, examining how differently the condensed-phase organic matter is distributed across the mixing states in the model. The results demonstrate the importance of representing organic aerosol as a semi-volatile aerosol, and explicitly calculating the partitioning of organic species between the gas and particulate phases.

  16. FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

    Energy Technology Data Exchange (ETDEWEB)

    John F. Schabron; Joseph F. Rovani, Jr.; Theresa M. Bomstad

    2003-07-01

    Western Research Institute (WRI) is continuing work toward the development of new screening methodology and a test kit to measure halogenated volatile organic compounds (VOCs) in the field. Heated diode and corona discharge sensors are commonly used to detect leaks of refrigerants from air conditioners, freezers, and refrigerators. They are both selective to the presence of halogens. In prior work, the devices were tested for response to carbon tetrachloride, heptane, toluene, and water vapors. In the current work, sensor response was evaluated with sixteen halogenated VOCs relative to carbon tetrachloride. The results show that the response of the various chlorinated VOCs is within an order of magnitude of the response to carbon tetrachloride for each of the sensors. Thus, for field screening a single response factor can be used. Both types of leak detectors are being further modified to provide an on-board LCD signal readout, which is related to VOC concentration. The units will be fully portable and will operate with 115-V line or battery power. Signal background, noise level, and response data on the Bacharach heated diode detector and the TIF corona discharge detector show that when the response curves are plotted against the log of concentration, the plot is linear to the upper limit for the particular unit, with some curvature at lower levels. When response is plotted directly against concentration, the response is linear at the low end and is curved at the high end. The dynamic ranges for carbon tetrachloride of the two devices from the lower detection limit (S/N=2) to signal saturation are 4-850 vapor parts per million (vppm) for the corona discharge unit and 0.01-70 vppm for the heated diode unit. Additional circuit modifications are being made to lower the detection limit and increase the dynamic response range of the corona discharge unit. The results indicate that both devices show potential utility for future analytical method development work toward

  17. Fate of Volatile Organic Compounds in Constructed Wastewater Treatment Wetlands

    Science.gov (United States)

    Keefe, S.H.; Barber, L.B.; Runkel, R.L.; Ryan, J.N.

    2004-01-01

    The fate of volatile organic compounds was evaluated in a wastewater-dependent constructed wetland near Phoenix, AZ, using field measurements and solute transport modeling. Numerically based volatilization rates were determined using inverse modeling techniques and hydraulic parameters established by sodium bromide tracer experiments. Theoretical volatilization rates were calculated from the two-film method incorporating physicochemical properties and environmental conditions. Additional analyses were conducted using graphically determined volatilization rates based on field measurements. Transport (with first-order removal) simulations were performed using a range of volatilization rates and were evaluated with respect to field concentrations. The inverse and two-film reactive transport simulations demonstrated excellent agreement with measured concentrations for 1,4-dichlorobenzene, tetrachloroethene, dichloromethane, and trichloromethane and fair agreement for dibromochloromethane, bromo-dichloromethane, and toluene. Wetland removal efficiencies from inlet to outlet ranged from 63% to 87% for target compounds.

  18. Organic matters: investigating the sources, transport, and fate of organic matter in Fanno Creek, Oregon

    Science.gov (United States)

    Sobieszczyk, Steven; Keith, Mackenzie K.; Goldman, Jami H.; Rounds, Stewart A.

    2015-01-01

    The term organic matter refers to the remnants of all living material. This can include fallen leaves, yard waste, animal waste, downed timber, or the remains of any other plant and animal life. Organic matter is abundant both on land and in water. Investigating organic matter is necessary for understanding the fate and transport of carbon (a major constituent of organic matter).

  19. Photodissolution of soil organic matter

    Science.gov (United States)

    Mayer, L.M.; Thornton, K.R.; Schick, L.L.; Jastrow, J.D.; Harden, J.W.

    2012-01-01

    Sunlight has been shown to enhance loss of organic matter from aquatic sediments and terrestrial plant litter, so we tested for similar reactions in mineral soil horizons. Losses of up to a third of particulate organic carbon occurred after continuous exposure to full-strength sunlight for dozens of hours, with similar amounts appearing as photodissolved organic carbon. Nitrogen dissolved similarly, appearing partly as ammonium. Modified experiments with interruption of irradiation to include extended dark incubation periods increased loss of total organic carbon, implying remineralization by some combination of light and microbes. These photodissolution reactions respond strongly to water content, with reaction extent under air-dry to fully wet conditions increasing by a factor of 3-4 fold. Light limitation was explored using lamp intensity and soil depth experiments. Reaction extent varied linearly with lamp intensity. Depth experiments indicate that attenuation of reaction occurs within the top tens to hundreds of micrometers of soil depth. Our data allow only order-of-magnitude extrapolations to field conditions, but suggest that this type of reaction could induce loss of 10-20% of soil organic carbon in the top 10. cm horizon over a century. It may therefore have contributed to historical losses of soil carbon via agriculture, and should be considered in soil management on similar time scales. ?? 2011 Elsevier B.V.

  20. Are Some Fungal Volatile Organic Compounds (VOCs) Mycotoxins?

    OpenAIRE

    Bennett, Joan W.; Arati A. Inamdar

    2015-01-01

    Volatile organic compounds (VOCs) are carbon-compounds that easily evaporate at room temperature. Toxins are biologically produced poisons; mycotoxins are those toxins produced by microscopic fungi. All fungi emit blends of VOCs; the qualitative and quantitative composition of these volatile blends varies with the species of fungus and the environmental situation in which the fungus is grown. These fungal VOCs, produced as mixtures of alcohols, aldehydes, acids, ethers, esters, ketones, terpe...

  1. Measurement of volatile organic compounds in human blood.

    OpenAIRE

    Ashley, D L; Bonin, M A; Cardinali, F L; McCraw, J. M.; Wooten, J V

    1996-01-01

    Volatile organic compounds (VOCs) are an important public health problem throughout the developed world. Many important questions remain to be addressed in assessing exposure to these compounds. Because they are ubiquitous and highly volatile, special techniques must be applied in the analytical determination of VOCs. The analytical methodology chosen to measure toxicants in biological materials must be well validated and carefully carried out; poor quality assurance can lead to invalid resul...

  2. Do Time-Varying Covariances, Volatility Comovement and Spillover Matter?

    OpenAIRE

    Lakshmi Balasubramanyan

    2005-01-01

    Financial markets and their respective assets are so intertwined; analyzing any single market in isolation ignores important information. We investigate whether time varying volatility comovement and spillover impact the true variance-covariance matrix under a time-varying correlation set up. Statistically significant volatility spillover and comovement between US, UK and Japan is found. To demonstrate the importance of modelling volatility comovement and spillover, we look at a simple portfo...

  3. Determination of non-volatile and volatile organic acids in Korean traditional fermented soybean paste (Doenjang).

    Science.gov (United States)

    Shukla, Shruti; Choi, Tae Bong; Park, Hae-Kyong; Kim, Myunghee; Lee, In Koo; Kim, Jong-Kyu

    2010-01-01

    Organic acids are formed in food as a result of metabolism of large molecular mass compounds. These organic acids play an important role in the taste and aroma of fermented food products. Doenjang is a traditional Korean fermented soybean paste product that provides a major source of protein. The quantitative data for volatile and non-volatile organic acid contents of 18 samples of Doenjang were determined by comparing the abundances of each peak by gas (GC) and high performance liquid chromatography (HPLC). The mean values of volatile organic acids (acetic acid, butyric acid, propionic acid and 3-methyl butanoic acid), determined in 18 Doenjang samples, were found to be 91.73, 29.54, 70.07 and 19.80 mg%, respectively, whereas the mean values of non-volatile organic acids, such as oxalic acid, citric acid, lactic acid and succinic acid, were noted to be 14.69, 5.56, 9.95 and 0.21 mg%, respectively. Malonic and glutaric acids were absent in all the tested samples of Doenjang. The findings of this study suggest that determination of organic acid contents by GC and HPLC can be considered as an affective approach to evaluate the quality characteristics of fermented food products.

  4. Organic and volatile elements in the solar system

    Directory of Open Access Journals (Sweden)

    Remusat L.

    2012-01-01

    Full Text Available Chondrites and comets have accreted primitive materials from the early solar system. Those materials include organics, water and other volatile components. The most primitive chondrites and comets have undergone few modifications on their respective parent bodies and can deliver to laboratories components that were present at the origin of the protosolar nebula. Here I present a review of the organic material and volatile components that have been studied in the most primitive chondrites, and the last data from the stardust mission about the cometary record. This paper focuses on materials that can be studied in laboratories, by mass spectrometry, ion probes or organic chemistry techniques.

  5. Detection of volatile organic peroxides in indoor air.

    Science.gov (United States)

    Hong, J; Maguhn, J; Freitag, D; Kettrup, A

    2001-12-01

    A supercritical fluid extraction cell filled with adsorbent (Carbotrap and Carbotrap C) was used directly as a sampling tube to enrich volatile organic compounds in air. After sampling, the analytes were extracted by supercritical fluid CO2 with methanol as modifier. Collected organic peroxides were then determined by a RP-HPLC method developed and validated previously using post-column derivatization and fluorescence detection. Some volatile organic peroxides were found in indoor air in a new car and a newly decorated kitchen in the lower microg m(-3) range. tert-Butyl perbenzoate, di-tert-butyl peroxide, and tert-butylcumyl peroxide could be identified.

  6. Volatile organic compounds and oxides of nitrogen. Further emission reductions

    Energy Technology Data Exchange (ETDEWEB)

    Froste, H. [comp.

    1996-12-31

    This report presents the current status in relation to achievement of the Swedish Environmental target set by Parliament to reduce emission of volatile organic compounds by 50 per cent between 1988 and 2000. It also instructed the Agency to formulate proposed measures to achieve a 50 per cent reduction of emission of nitrogen oxides between 1985 and 2005. The report presents an overall account of emission trends for volatile organic compounds (from all sectors) and nitrogen oxides (from the industry sector) and steps proposed to achieve further emission reductions. 43 refs

  7. Role of organic volatile profiles in clinical diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Zlatkis, A. (Univ. of Houston, TX); Brazell, R.S.; Poole, C.F.

    1981-06-01

    The organic volatile constituents of biological fluids contain clinically useful diagnostic information for the recognition of metabolic disorders in man. To gain access to this information, it was necessary to develop the methodology for reproducibly stripping the trace concentrations of volatiles from biological fluids (dynamic headspace, gas phase-stripping, solvent extraction, and the transevaporator technique), to separate the complex extracts by high-resolution capillary column gas chromatography, and to develop computer-aided data-handling and pattern-recognition techniques for analyzing the immense amount of information generated. The normal and pathological organic volatiles identified by gas chromatography-mass spectrometry in urine, serum, and breast milk are tabulated. Clinical applications of the above techniques to the study and diagnosis of diabetes mellitus, respiratory virus infection, renal insufficiency, and cancer are described.

  8. 76 FR 18893 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Volatile Organic Compound...

    Science.gov (United States)

    2011-04-06

    ... Organic Compound Emission Control Measures for Lithographic and Letterpress Printing in Cleveland AGENCY... volatile organic compound (VOC) rule. These rule revisions specify compliance dates for subject facilities... approved offset lithographic and letterpress printing volatile organic compound (VOC) rule for...

  9. 76 FR 4835 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Volatile Organic Compound...

    Science.gov (United States)

    2011-01-27

    ... Organic Compound Reinforced Plastics Composites Production Operations Rule AGENCY: Environmental... control of volatile organic compound (VOC) emissions from reinforced plastic composites production..., Volatile organic compounds. Dated: January 14, 2011. Susan Hedman, Regional Administrator, Region...

  10. 76 FR 41086 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Volatile Organic Compound...

    Science.gov (United States)

    2011-07-13

    ... Organic Compound Reinforced Plastic Composites Production Operations Rule AGENCY: Environmental Protection...) a new rule for the control of volatile organic compound (VOC) emissions from reinforced plastic..., Reporting and recordkeeping requirements, Volatile organic compounds. Dated: June 24, 2011. Susan...

  11. Priming of native soil organic matter by pyrogenic organic matter

    Science.gov (United States)

    DeCiucies, Silene; Dharmakeerthi, Saman; Whitman, Thea; Woolf, Dominic; Lehmann, Johannes

    2015-04-01

    Priming, in relation to pyrogenic organic matter (PyOM), describes the change in mineralization rate of non-pyrogenic ("native") soil organic matter (nSOM) due to the addition of PyOM. Priming may be 'positive', in that the addition of pyC increases the mineralization rate of native SOM, or 'negative', in that the mineralization rate of nSOM is decreased. Reasons for increased mineralization may include: (i) co-metabolism: microbial decomposition of labile C-additions increases microbial activity, and facilitates additional decomposition of npSOC by active enzymes; (ii) stimulation: substrate additions result in lifted pH, nutrient, oxygen, or water constraints resulting in increased microbial activity. Decreased mineralization may be a result of: (i) inhibition: the opposite of stimulation whereby constraints are aggravated by substrate addition. Substrate addition may also cause inhibition by interfering with enzymes or signaling compounds; (ii) preferential substrate utilization: labile fraction of PyOM additions are preferentially used up by microbes thus causing a decrease in nSOC decomposition; (iii) sorption: organic compounds are adsorbed onto PyOM surfaces, decreasing their rate of mineralization; (iv) stabilization: formation of organo-mineral associations forms stable SOC pools. We have conducted a suite of experiments to investigate these potential interactions. In a seven year long incubation study, PyOM additions increased total OM mineralization for the first 2.5 years, was equal to control after 6.2 years, and was 3% lower after 7.1 years. Cumulative nSOM mineralization was 23% less with the PyOM additions than without, and over 60% of the added PyOM was present in the labile soil fraction after the 7.1 year incubation. Two additional incubation studies, one with and without plants, showed greater nSOM mineralization in the short term and lower nSOM mineralization over the long term. Increased nSOC mineralization due to the presence of plants was

  12. Influence of volatile organic compounds on Fusarium graminearum mycotoxin production

    Science.gov (United States)

    Volatile organic compounds (VOCs) are involved in a diverse range of ecological interactions. Due to their low molecular weight, lipophilic nature, and high vapor pressure at ambient temperatures, they can serve as airborne signaling molecules that are capable of mediating inter and intraspecies com...

  13. Predicting the emission of volatile organic compounds from silage systems

    Science.gov (United States)

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

  14. Volatile organic compounds of whole grain soft winter wheat

    Science.gov (United States)

    The aroma from volatile organic compounds (VOCs) is an indicator of grain soundness and also an important quality attribute of grain foods. To identify the inherent VOCs of wheat grain unaffected by fungal infestation and other extrinsic factors, grains of nine soft wheat varieties were collected at...

  15. Modeling emissions of volatile organic compounds from silage

    Science.gov (United States)

    Photochemical smog is a major air pollution problem and a significant cause of premature death in the U.S. Smog forms in the presence of volatile organic compounds (VOCs), which are emitted primarily from industry and motor vehicles in the U.S. However, dairy farms may be an important source in so...

  16. Qualitative analysis of volatile organic compounds on biochar

    Science.gov (United States)

    Qualitative identification of sorbed volatile organic compounds (VOCs) on biochar was conducted by headspace thermal desorption coupled to capillary gas chromatographic-mass spectrometry. VOCs may have a mechanistic role influencing plant and microbial responses to biochar amendments, since VOCs ca...

  17. Organic matter and soil moisture content and double cropping with organic matter sourceplants

    OpenAIRE

    John Bako Baon; Aris Wibawa

    2005-01-01

    Double cropping of coffee with organic matter source plants is thought to increase organic matter content of soil. This study examined the effect of double cropping of coffee and organic matter source plants on soil organic matter content and yield of coffee plants. Arabica coffee trees in Andungsari Experimental Station (Bondowoso district), 1400 m asl. and climate type C; and Robusta coffee trees in Sumberasin Experimental Station (Malang district), 550 m asl. and climate type C, were used ...

  18. Quantifying the volatility of organic aerosol in the southeastern US

    Science.gov (United States)

    Saha, Provat K.; Khlystov, Andrey; Yahya, Khairunnisa; Zhang, Yang; Xu, Lu; Ng, Nga L.; Grieshop, Andrew P.

    2017-01-01

    The volatility of organic aerosols (OA) has emerged as a property of primary importance in understanding their atmospheric life cycle, and thus abundance and transport. However, quantitative estimates of the thermodynamic (volatility, water solubility) and kinetic parameters dictating ambient-OA gas-particle partitioning, such as saturation concentrations (C∗), enthalpy of evaporation (ΔHvap), and evaporation coefficient (γe), are highly uncertain. Here, we present measurements of ambient-OA volatility at two sites in the southeastern US, one at a rural setting in Alabama dominated by biogenic volatile organic compounds (BVOCs) as part of the Southern Oxidant and Aerosol Study (SOAS) in June-July 2013, and another at a more anthropogenically influenced urban location in North Carolina during October-November 2013. These measurements applied a dual-thermodenuder (TD) system, in which temperature and residence times are varied in parallel to constrain equilibrium and kinetic aerosol volatility properties. Gas-particle partitioning parameters were determined via evaporation kinetic model fits to the dual-TD observations. OA volatility parameter values derived from both datasets were similar despite the fact that measurements were collected in distinct settings and seasons. The OA volatility distributions also did not vary dramatically over the campaign period or strongly correlate with OA components identified via positive matrix factorization of aerosol mass spectrometer data. A large portion (40-70 %) of measured ambient OA at both sites was composed of very-low-volatility organics (C∗ ≤ 0.1 µg m-3). An effective ΔHvap of bulk OA of ˜ 80-100 kJ mol-1 and a γe value of ˜ 0.5 best describe the evaporation observed in the TDs. This range of ΔHvap values is substantially higher than that typically assumed for simulating OA in atmospheric models (30-40 kJ mol-1). TD data indicate that γe is on the order of 0.1 to 0.5, indicating that repartitioning

  19. Organic matter mineralization in marine systems

    NARCIS (Netherlands)

    Middelburg, J.J.; Vlug, T.; Van der Nat, F.J.

    1993-01-01

    Many of the reactions and biogeochemical processes that occur in the marine environment are related directly or indirectly to the mineralization of organic matter. Decomposition of organic matter is responsible for the recycling of essential nutrients, for the oxygen balance of the ocean and its sed

  20. Organic matter mineralization in marine systems

    NARCIS (Netherlands)

    Middelburg, J.J.; Vlug, T.; Van der Nat, F.J.

    1993-01-01

    Many of the reactions and biogeochemical processes that occur in the marine environment are related directly or indirectly to the mineralization of organic matter. Decomposition of organic matter is responsible for the recycling of essential nutrients, for the oxygen balance of the ocean and its

  1. When Organization Fails: Why Authority Matters

    DEFF Research Database (Denmark)

    Blaschke, Steffen

    2015-01-01

    Review of: James R. Taylor and Elizabeth J. Van Every / When Organization Fails: Why Authority Matters. (New York: Routledge, 2014. 220 pp. ISBN: 978 0415741668)......Review of: James R. Taylor and Elizabeth J. Van Every / When Organization Fails: Why Authority Matters. (New York: Routledge, 2014. 220 pp. ISBN: 978 0415741668)...

  2. Size-dependence of volatile and semi-volatile organic carbon content in phytoplankton cells

    Directory of Open Access Journals (Sweden)

    Sergio eRuiz-Halpern

    2014-07-01

    Full Text Available The content of volatile and semivolatile organic compounds (VOC and SOC, measured as exchangeable dissolved organic carbon (EDOC, was quantified in 9 phytoplanktonic species that spanned 4 orders of magnitude in cell volume, by disrupting the cells and quantifying the gaseous organic carbon released. EDOC content varied 4 orders of magnitude, from 0.0015 to 14.12 pg C cell-1 in the species studied and increased linearly with increasing phytoplankton cell volume following the equation EDOC (pg C cell-1 = -2.35 x cellular volume (CV, µm3 cell-1 0.90 (± 0.3, with a slope (0.90 not different from 1 indicating a constant increase in volatile carbon as the cell size of phytoplankton increased. The percentage of EDOC relative to total cellular carbon was small but varied 20 fold from 0.28 % to 5.17 %, and no obvious taxonomic pattern in the content of EDOC was appreciable for the species tested. The cell release rate of EDOC is small compared to the amount of carbon in the cell and difficult to capture. Nonetheless, the results point to a potential flux of volatile and semivolatile phytoplankton-derived organic carbon to the atmosphere that has been largely underestimated and deserves further attention in the future.

  3. Nanostructured Polypyrrole-Based Ammonia and Volatile Organic Compound Sensors.

    Science.gov (United States)

    Šetka, Milena; Drbohlavová, Jana; Hubálek, Jaromír

    2017-03-10

    The aim of this review is to summarize the recent progress in the fabrication of efficient nanostructured polymer-based sensors with special focus on polypyrrole. The correlation between physico-chemical parameters, mainly morphology of various polypyrrole nanostructures, and their sensitivity towards selected gas and volatile organic compounds (VOC) is provided. The different approaches of polypyrrole modification with other functional materials are also discussed. With respect to possible sensors application in medicine, namely in the diagnosis of diseases via the detection of volatile biomarkers from human breath, the sensor interaction with humidity is described as well. The major attention is paid to analytes such as ammonia and various alcohols.

  4. History of Martian volatiles - Implications for organic synthesis.

    Science.gov (United States)

    Fanale, F. P.

    1971-01-01

    A theoretical reconstruction of the history of Martian volatiles indicates that Mars probably possessed a substantial reducing atmosphere at the outset of its history, and that its present tenuous and more oxidized atmosphere is the result of extensive chemical evolution. As a consequence, it is probable that Martian atmospheric chemical conditions, now hostile with respect to abiotic organic synthesis in the gas phase, were initially favorable. Evidence indicating the chronology and degradational history of Martian surface features, surface mineralogy, bulk volatile content, internal mass distribution, and thermal history suggests that Mars catastrophically developed a substantial reducing atmosphere as the result of rapid accretion.

  5. Nanostructured Polypyrrole-Based Ammonia and Volatile Organic Compound Sensors

    Directory of Open Access Journals (Sweden)

    Milena Šetka

    2017-03-01

    Full Text Available The aim of this review is to summarize the recent progress in the fabrication of efficient nanostructured polymer-based sensors with special focus on polypyrrole. The correlation between physico-chemical parameters, mainly morphology of various polypyrrole nanostructures, and their sensitivity towards selected gas and volatile organic compounds (VOC is provided. The different approaches of polypyrrole modification with other functional materials are also discussed. With respect to possible sensors application in medicine, namely in the diagnosis of diseases via the detection of volatile biomarkers from human breath, the sensor interaction with humidity is described as well. The major attention is paid to analytes such as ammonia and various alcohols.

  6. Nanostructured Polypyrrole-Based Ammonia and Volatile Organic Compound Sensors

    Science.gov (United States)

    Šetka, Milena; Drbohlavová, Jana; Hubálek, Jaromír

    2017-01-01

    The aim of this review is to summarize the recent progress in the fabrication of efficient nanostructured polymer-based sensors with special focus on polypyrrole. The correlation between physico-chemical parameters, mainly morphology of various polypyrrole nanostructures, and their sensitivity towards selected gas and volatile organic compounds (VOC) is provided. The different approaches of polypyrrole modification with other functional materials are also discussed. With respect to possible sensors application in medicine, namely in the diagnosis of diseases via the detection of volatile biomarkers from human breath, the sensor interaction with humidity is described as well. The major attention is paid to analytes such as ammonia and various alcohols. PMID:28287435

  7. History of Martian volatiles - Implications for organic synthesis.

    Science.gov (United States)

    Fanale, F. P.

    1971-01-01

    A theoretical reconstruction of the history of Martian volatiles indicates that Mars probably possessed a substantial reducing atmosphere at the outset of its history, and that its present tenuous and more oxidized atmosphere is the result of extensive chemical evolution. As a consequence, it is probable that Martian atmospheric chemical conditions, now hostile with respect to abiotic organic synthesis in the gas phase, were initially favorable. Evidence indicating the chronology and degradational history of Martian surface features, surface mineralogy, bulk volatile content, internal mass distribution, and thermal history suggests that Mars catastrophically developed a substantial reducing atmosphere as the result of rapid accretion.

  8. Natural Organic Matter in Ecosystems - a Review

    Directory of Open Access Journals (Sweden)

    Kosobucki Przemysław

    2014-12-01

    Full Text Available One of the most essential parameters limiting the potential use of the ecosystem (soil, water is the content of the organic matter. The natural organic matter (NOM is a ubiquitous component of the lithosphere and hydrosphere that constitutes one of the largest reservoirs of the carbon in the environment. Natural organic substances play several important functions in ecosystems and they are necessary for their normal functioning. Despite many years of the research and using many advanced analytical techniques, their structure has not been fully explained. The main aim of this review is to present the actual state of the knowledge about the natural organic matter and provide a comprehensive overview of the research that has explored up to date in this matter. The additional attention was focused on the relations within and between humic and fulvic acids in terrestrial and aquatic environments. Special attention is focused on the analytical methods used to analysis natural organic matter

  9. Metal organic frameworks as sorption media for volatile and semi-volatile organic compounds at ambient conditions

    Science.gov (United States)

    Vellingiri, Kowsalya; Szulejko, Jan E.; Kumar, Pawan; Kwon, Eilhann E.; Kim, Ki-Hyun; Deep, Akash; Boukhvalov, Danil W.; Brown, Richard J. C.

    2016-06-01

    In this research, we investigated the sorptive behavior of a mixture of 14 volatile and semi-volatile organic compounds (four aromatic hydrocarbons (benzene, toluene, p-xylene, and styrene), six C2-C5 volatile fatty acids (VFAs), two phenols, and two indoles) against three metal-organic frameworks (MOFs), i.e., MOF-5, Eu-MOF, and MOF-199 at 5 to 10 mPa VOC partial pressures (25 °C). The selected MOFs exhibited the strongest affinity for semi-volatile (polar) VOC molecules (skatole), whereas the weakest affinity toward was volatile (non-polar) VOC molecules (i.e., benzene). Our experimental results were also supported through simulation analysis in which polar molecules were bound most strongly to MOF-199, reflecting the presence of strong interactions of Cu2+ with polar VOCs. In addition, the performance of selected MOFs was compared to three well-known commercial sorbents (Tenax TA, Carbopack X, and Carboxen 1000) under the same conditions. The estimated equilibrium adsorption capacity (mg.g‑1) for the all target VOCs was in the order of; MOF-199 (71.7) >Carboxen-1000 (68.4) >Eu-MOF (27.9) >Carbopack X (24.3) >MOF-5 (12.7) >Tenax TA (10.6). Hopefully, outcome of this study are expected to open a new corridor to expand the practical application of MOFs for the treatment diverse VOC mixtures.

  10. Copper corrosion originated by volatile organic acid vapours; Corrosion del cobre por acidos organicos volatiles

    Energy Technology Data Exchange (ETDEWEB)

    Cano, E.; Polo, J. L.; Kong, D. Y.; Mora, E. M.; Lopez-Caballero, J. A.; Bastidas, J. M.

    2004-07-01

    The corrosion of copper in the presence of volatile organic acids is frequent. Thus, for example, it is known that failures by corrosion of the copper tubes take place in the air conditioning equipment, caused by volatile organic acids emitted by oils used in their manufacturing. Another frequent case is the corrosion of copper objects caused by the acids emitted by the materials used in packing, wood and resins, amongst others. This communication presents the corrosion results of copper exposed to 100% relative humidity and different concentrations (10-300ppm) of formic (HCOOH), acetic (CH{sub 3}COOH), propionic (CH{sub 3}CH{sub 2}COOH) and butyric (CH{sub 3}(CH{sub 2}){sub 2}COOH) acid vapours, for short exposure times. the techniques used were gravimetric analysis, scanning electron microscopy (SEM) and X-ray diffraction (XRD). (Author) 9 refs.

  11. Can volatile organic compounds be markers of sea salt?

    Science.gov (United States)

    Silva, Isabel; Coimbra, Manuel A; Barros, António S; Marriott, Philip J; Rocha, Sílvia M

    2015-02-15

    Sea salt is a handmade food product that is obtained by evaporation of seawater in saltpans. During the crystallisation process, organic compounds from surroundings can be incorporated into sea salt crystals. The aim of this study is to search for potential volatile markers of sea salt. Thus, sea salts from seven north-east Atlantic Ocean locations (France, Portugal, Continental Spain, Canary Islands, and Cape Verde) were analysed by headspace solid-phase microextraction combined with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry. A total of 165 compounds were detected, ranging from 32 to 71 compounds per salt. The volatile composition revealed the variability and individuality of each salt, and a set of ten compounds were detected in all samples. From these, seven are carotenoid-derived compounds that can be associated with the typical natural surroundings of ocean hypersaline environment. These ten compounds are proposed as potential volatile markers of sea salt.

  12. Environmental factors regulating soil organic matter chlorination

    Science.gov (United States)

    Svensson, Teresia; Montelius, Malin; Reyier, Henrik; Rietz, Karolina; Karlsson, Susanne; Lindberg, Cecilia; Andersson, Malin; Danielsson, Åsa; Bastviken, David

    2016-04-01

    Natural chlorination of organic matter is common in soils. Despite the widespread abundance of soil chlorinated soil organic matter (SOM), frequently exceeding soil chloride abundance in surface soils, and a common ability of microorganisms to produce chlorinated SOM, we lack fundamental knowledge about dominating processes and organisms responsible for the chlorination. To take one step towards resolving the terrestrial chlorine (Cl) puzzle, this study aims to analyse how environmental factors influence chlorination of SOM. Four factors were chosen for this study: soil moisture (W), nitrogen (N), chloride (Cl) and organic matter quality (C). These factors are all known to be important for soil processes. Laboratory incubations with 36Cl as a Cl tracer were performed in a two soil incubation experiments. It was found that addition of chloride and nitrogen seem to hamper the chlorination. For the C treatment, on the other hand, the results show that chlorination is enhanced by increased availability of labile organic matter (glucose and maltose). Even higher chlorination was observed when nitrogen and water were added in combination with labile organic matter. The effect that more labile organic matter strongly stimulated the chlorination rates was confirmed by the second separate experiment. These results indicate that chlorination was not primarily a way to cut refractory organic matter into digestible molecules, representing one previous hypothesis, but is related with microbial metabolism in other ways that will be further discussed in our presentation.

  13. Quantitative estimates of the volatility of ambient organic aerosol

    Directory of Open Access Journals (Sweden)

    C. D. Cappa

    2010-01-01

    Full Text Available Measurements of the sensitivity of organic aerosol (OA, and its components mass to changes in temperature were recently reported by Huffman et al. (2009 using a tandem thermodenuder-aerosol mass spectrometer (TD-AMS system in Mexico City and the Los Angeles area. Here, we use these measurements to derive quantitative estimates of aerosol volatility within the framework of absorptive partitioning theory using a kinetic model of aerosol evaporation in the TD. OA volatility distributions (or "basis-sets" are determined using several assumptions as to the enthalpy of vaporization (ΔHvap. We present two definitions of "non-volatile OA," one being a global and one a local definition. Based on these definitions, our analysis indicates that a substantial fraction of the organic aerosol is comprised of non-volatile components that will not evaporate under any atmospheric conditions, on the order of 50–80% when the most realistic ΔHvap assumptions are considered. The sensitivity of the total OA mass to dilution and ambient changes in temperature has been assessed for the various ΔHvap assumptions. The temperature sensitivity is relatively independent of the particular ΔHvap assumptions whereas dilution sensitivity is found to be greatest for the low (ΔHvap = 50 kJ/mol and lowest for the high (ΔHvap = 150 kJ/mol assumptions. This difference arises from the high ΔHvap assumptions yielding volatility distributions with a greater fraction of non-volatile material than the low ΔHvap assumptions. If the observations are fit using a 1 or 2-component model the sensitivity of the OA to dilution is unrealistically high. An empirical method introduced by Faulhaber et al. (2009 has also been used to independently estimate a volatility distribution for the ambient OA and is found to give results consistent with the high and variable ΔHvap assumptions. Our

  14. Isolation and preconcentration of volatile organic compounds from water; Review

    Energy Technology Data Exchange (ETDEWEB)

    Namiesnik, J.; Gorecki, T.; Biziuk, M.; Torres, L. (Technical Univ. of Gdansk (Poland) Ecole Nationale Superieure de Chimie, Toulouse (France))

    1990-10-01

    Methods for the isolation and/or concentration of volatile organic compounds from water samples for trace organic analysis by gas chromatography are reviewed. The following basic groups of methods are discussed: liquid-liquid extraction, adsorption on solid sorbents, extraction with gas (gas stripping and static and dynamic headspace techniques) and membrane processes. The theoretical bases of these methods are discussed. Experimental arrangements for the isolation and/or concentration of volatile compounds from water are presented and discussed with respect to their efficiency. The applicability of the described methods to the isolation and/or concentration of various organic compounds from waters of various origins is discussed. 26 figs., 7 tabs., 695 refs.

  15. A large source of low-volatility secondary organic aerosol.

    Science.gov (United States)

    Ehn, Mikael; Thornton, Joel A; Kleist, Einhard; Sipilä, Mikko; Junninen, Heikki; Pullinen, Iida; Springer, Monika; Rubach, Florian; Tillmann, Ralf; Lee, Ben; Lopez-Hilfiker, Felipe; Andres, Stefanie; Acir, Ismail-Hakki; Rissanen, Matti; Jokinen, Tuija; Schobesberger, Siegfried; Kangasluoma, Juha; Kontkanen, Jenni; Nieminen, Tuomo; Kurtén, Theo; Nielsen, Lasse B; Jørgensen, Solvejg; Kjaergaard, Henrik G; Canagaratna, Manjula; Maso, Miikka Dal; Berndt, Torsten; Petäjä, Tuukka; Wahner, Andreas; Kerminen, Veli-Matti; Kulmala, Markku; Worsnop, Douglas R; Wildt, Jürgen; Mentel, Thomas F

    2014-02-27

    Forests emit large quantities of volatile organic compounds (VOCs) to the atmosphere. Their condensable oxidation products can form secondary organic aerosol, a significant and ubiquitous component of atmospheric aerosol, which is known to affect the Earth's radiation balance by scattering solar radiation and by acting as cloud condensation nuclei. The quantitative assessment of such climate effects remains hampered by a number of factors, including an incomplete understanding of how biogenic VOCs contribute to the formation of atmospheric secondary organic aerosol. The growth of newly formed particles from sizes of less than three nanometres up to the sizes of cloud condensation nuclei (about one hundred nanometres) in many continental ecosystems requires abundant, essentially non-volatile organic vapours, but the sources and compositions of such vapours remain unknown. Here we investigate the oxidation of VOCs, in particular the terpene α-pinene, under atmospherically relevant conditions in chamber experiments. We find that a direct pathway leads from several biogenic VOCs, such as monoterpenes, to the formation of large amounts of extremely low-volatility vapours. These vapours form at significant mass yield in the gas phase and condense irreversibly onto aerosol surfaces to produce secondary organic aerosol, helping to explain the discrepancy between the observed atmospheric burden of secondary organic aerosol and that reported by many model studies. We further demonstrate how these low-volatility vapours can enhance, or even dominate, the formation and growth of aerosol particles over forested regions, providing a missing link between biogenic VOCs and their conversion to aerosol particles. Our findings could help to improve assessments of biosphere-aerosol-climate feedback mechanisms, and the air quality and climate effects of biogenic emissions generally.

  16. 75 FR 2090 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Volatile Organic Compound...

    Science.gov (United States)

    2010-01-14

    ... Organic Compound Automobile Refinishing Rules for Indiana AGENCY: Environmental Protection Agency (EPA... relations, Nitrogen dioxide, Ozone, Reporting and recordkeeping requirements, Volatile organic compounds... Plan (SIP). These rule revisions extend the applicability of Indiana's approved volatile...

  17. A Novel Type of Oil—generating Organic Matter —Crystal—enclosed Organic Matter

    Institute of Scientific and Technical Information of China (English)

    周中毅; 裴存民; 等

    1992-01-01

    The comparative study of organic matter in carbonate rocks and argillaceous rocks from the same horizon indicates that the organic thermal maturities of carbonate rocks are much lower than those of argillaceous rocks .Ana extensive analysis of extracted and inclused organic matter from the same sample shows that inclused organic matter is different from extracted organic matter,and the thermal maturity of the former is usually lower than that of the latter in terms of biomarker structural parameters.It seems that carbonate mineras could preserve organic matter and retard organic maturation.The inclused organic matter,abundant in most carbonate rocks,will be released from minerals and transformed into oil and gas during the high-thermal maturity stage.

  18. Chemodestructive fractionation of soil organic matter

    Science.gov (United States)

    Popov, A. I.; Rusakov, A. V.

    2016-06-01

    The method of chemodestructive fractionation is suggested to assess the composition of soil organic matter. This method is based on determination of the resilience of soil organic matter components and/or different parts of organic compounds to the impact of oxidizing agents. For this purpose, a series of solutions with similar concentration of the oxidant (K2Cr2O7), but with linearly increasing oxidative capacity was prepared. Chemodestructive fractionation showed that the portion of easily oxidizable (labile) organic matter in humus horizons of different soil types depends on the conditions of soil formation. It was maximal in hydromorphic soils of the taiga zone and minimal in automorphic soils of the dry steppe zone. The portion of easily oxidizable organic matter in arable soils increased with an increase in the rate of organic fertilizers application. The long-lasting agricultural use of soils and burying of the humus horizons within the upper one-meter layer resulted in the decreasing content of easily oxidizable organic matter. It was found that the portion of easily oxidizable organic matter decreases by the mid-summer or fall in comparison with the spring or early summer period.

  19. 78 FR 11119 - Air Quality: Revision to Definition of Volatile Organic Compounds-Exclusion of trans

    Science.gov (United States)

    2013-02-15

    ... AGENCY 40 CFR Part 51 RIN 2060-AQ38 Air Quality: Revision to Definition of Volatile Organic Compounds...: Proposed rule. SUMMARY: The EPA is proposing to revise the definition of volatile organic compounds (VOCs..., Reporting and recordkeeping requirements, Volatile organic compounds. Dated: February 4, 2013. Lisa...

  20. Determination of organic chemicals in human whole blood: preliminary method development for volatile organics

    Energy Technology Data Exchange (ETDEWEB)

    Cramer, P.H.; Boggess, K.E.; Hosenfeld, J.M.; Remmers, J.C.; Breen, J.J.; Robinson, P.E.; Stroup, C.

    1988-04-01

    This article introduces a method for the detection and confirmation of selected volatile organics at parts-per-trillion (ppt) levels in whole human blood. Intended for routine use, the method consists of a dynamic headspace purge of water-diluted blood where a carrier gas sweeps the surface of the sample and removes a quantifiable amount of the volatile organics from the blood and into an adsorbent trap. The organics are thermally desorbed form the adsorbent trap and onto the analytical column in a gas-chromatographic/mass-spectrometric (GC/MS) system where limited mass-scan data are taken for qualitative and quantitative identification. The method can be employed for compounds normally defined as volatile organics, such as those on the EPA priority-pollutant-volatiles list. Method validation results and limited population-survey results are also presented here.

  1. Methods in plant foliar volatile organic compounds research 1

    OpenAIRE

    Materić, Dušan; Bruhn, Dan; Turner, Claire; Morgan, Geraint; Mason, Nigel J.; Gauci, Vincent

    2015-01-01

    Plants are a major atmospheric source of volatile organic compounds (VOCs). These secondary metabolic products protect plants from high-temperature stress, mediate in plant–plant and plant–insect communication, and affect our climate globally. The main challenges in plant foliar VOC research are accurate sampling, the inherent reactivity of some VOC compounds that makes them hard to detect directly, and their low concentrations. Plant VOC research relies on analytical techniques for trace gas...

  2. Marine Vibrio Species Produce the Volatile Organic Compound Acetone

    OpenAIRE

    Nemecek-Marshall, M; Wojciechowski, C; Kuzma, J.; Silver, G. M.; Fall, R.

    1995-01-01

    While screening aerobic, heterotrophic marine bacteria for production of volatile organic compounds, we found that a group of isolates produced substantial amounts of acetone. Acetone production was confirmed by gas chromatography, gas chromatography-mass spectrometry, and high-performance liquid chromatography. The major acetone producers were identified as nonclinical Vibrio species. Acetone production was maximal in the stationary phase of growth and was stimulated by addition of l-leucine...

  3. Volatile organic compound optical fiber sensors: a review

    OpenAIRE

    Arregui, Francisco J.; Candido Bariain; Matias, Ignacio R; Cesar Elosua

    2006-01-01

    Volatile organic compound (VOC) detection is a topic of growing interest with applications in diverse fields, ranging from environmental uses to the food or chemical industries. Optical fiber VOC sensors offering new and interesting properties which overcame some of the inconveniences found on traditional gas sensors appeared over two decades ago. Thanks to its minimum invasive nature and the advantages that optical fiber offers such as light weight, passive nature, low attenuation and the...

  4. New graphene fiber coating for volatile organic compounds analysis.

    Science.gov (United States)

    Zhang, GuoJuan; Guo, XiaoXi; Wang, ShuLing; Wang, XueLan; Zhou, YanPing; Xu, Hui

    2014-10-15

    In the work, a novel graphene-based solid phase microextraction-gas chromatography/mass spectrometry method was developed for the analysis of trace amount of volatile organic compounds in human exhaled breath vapor. The graphene fiber coating was prepared by a one-step hydrothermal reduction reaction. The fiber with porous and wrinkled structure exhibited excellent extraction efficiency toward eight studied volatile organic compounds (two n-alkanes, five n-aldehydes and one aromatic compound). Meanwhile, remarkable thermal and mechanical stability, long lifespan and low cost were also obtained for the fiber. Under the optimal conditions, the developed method provided low limits of detection (1.0-4.5ngL(-1)), satisfactory reproducibility (3.8-13.8%) and acceptable recoveries (93-122%). The method was applied successfully to the analysis of breath samples of lung cancer patients and healthy individuals. The unique advantage of this approach includes simple setup, non-invasive analysis, cost-efficient and sufficient sensitivity. The proposed method supply us a new possibility to monitor volatile organic compounds in human exhaled breath samples.

  5. Physicochemical characterization of organic matter during co ...

    African Journals Online (AJOL)

    TCHEGUENI

    Key words: Shea-nut cake, composting, organic matter, goat manure. ... analysis. All analyses were performed on samples taken at the beginning, after 30, 90 and 180 days of ..... Maturity assessment of composted olive mill wastes using UV.

  6. Volatile and semivolatile organic compounds in laboratory peat fire emissions

    Science.gov (United States)

    George, Ingrid J.; Black, Robert R.; Geron, Chris D.; Aurell, Johanna; Hays, Michael D.; Preston, William T.; Gullett, Brian K.

    2016-05-01

    In this study, volatile and semi-volatile organic compound (VOCs and SVOCs) mass emission factors were determined from laboratory peat fire experiments. The peat samples originated from two National Wildlife Refuges on the coastal plain of North Carolina, U.S.A. Gas- and particle-phase organic compounds were quantified by gas chromatography-mass spectrometry and by high pressure liquid chromatography. Hazardous air pollutants (HAPs) accounted for a large fraction (∼60%) of the speciated VOC emissions from peat burning, including large contributions of acetaldehyde, formaldehyde, benzene, toluene, and chloromethane. In the fine particle mass (PM2.5), the following organic compound classes were dominant: organic acids, levoglucosan, n-alkanes, and n-alkenes. Emission factors for the organic acids in PM2.5 including n-alkanoic acids, n-alkenoic acids, n-alkanedioic acids, and aromatic acids were reported for the first time for peat burning, representing the largest fraction of organic carbon (OC) mass (11-12%) of all speciated compound classes measured in this work. Levoglucosan contributed to 2-3% of the OC mass, while methoxyphenols represented 0.2-0.3% of the OC mass on a carbon mass basis. Retene was the most abundant particulate phase polycyclic aromatic hydrocarbon (PAH). Total HAP VOC and particulate PAH emissions from a 2008 peat wildfire in North Carolina were estimated, suggesting that peat fires can contribute a large fraction of state-wide HAP emissions.

  7. An approach to the use of fixed carbon-volatile matter graph

    NARCIS (Netherlands)

    Radovanović, Milan; Jankes, Goran

    1986-01-01

    The use of the fixed carbon-volatile matter (FC-VM) graph for quick calculations of proximate analysis data, as well as for simple presentation of coal classification is illustrated. From the position of the VM and FC values of a coal on the graph (on an ‘as received’ basis) it is possible to determ

  8. A large source of low-volatility secondary organic aerosol

    DEFF Research Database (Denmark)

    Ehn, Mikael; Thornton, Joel A.; Kleist, Einhard

    2014-01-01

    at significant mass yield in the gas phase and condense irreversibly onto aerosol surfaces to produce secondary organic aerosol, helping to explain the discrepancy between the observed atmospheric burden of secondary organic aerosol and that reported by many model studies. We further demonstrate how these low......-volatility vapours can enhance, or even dominate, the formation and growth of aerosol particles over forested regions, providing a missing link between biogenic VOCs and their conversion to aerosol particles. Our findings could help to improve assessments of biosphere-aerosol-climate feedback mechanisms, and the air...

  9. Determination of Volatile Organic Compounds in Selected Strains of Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Ivan Milovanović

    2015-01-01

    Full Text Available Microalgal biomass can be used in creating various functional food and feed products, but certain species of microalgae and cyanobacteria are known to produce various compounds causing off-flavour. In this work, we investigated selected cyanobacterial strains of Spirulina, Anabaena, and Nostoc genera originating from Serbia, with the aim of determining the chemical profile of volatile organic compounds produced by these organisms. Additionally, the influence of nitrogen level during growth on the production of volatile compounds was investigated for Nostoc and Anabaena strains. In addition, multivariate techniques, namely, principal component analysis (PCA and hierarchical cluster analysis (HCA, were used for making distinction among different microalgal strains. The results show that the main volatile compounds in these species are medium chain length alkanes, but other odorous compounds such as 2-methylisoborneol (0.51–4.48%, 2-pentylfuran (0.72–8.98%, β-cyclocitral (0.00–1.17%, and β-ionone (1.15–2.72% were also detected in the samples. Addition of nitrogen to growth medium was shown to negatively affect the production of 2-methylisoborneol, while geosmin was not detected in any of the analyzed samples, which indicates that the manipulation of growth conditions may be useful in reducing levels of some unwanted odor-causing components.

  10. [Generic method for determination of volatile organic solvents in cosmetics].

    Science.gov (United States)

    Da, Jing; Huang, Xianglu; Wang, Gangli; Cao, Jin; Zhang, Qingsheng

    2014-11-01

    A generic screening, confirmation and determination method was established based on 36 commonly used volatile organic solvents in cosmetics by headspace gas chromatography- mass spectrometry (GC-MS). This method included a database for pilot screening and identifi- cation of those solvents and their quantitative method. Pilot screening database was composed by two sections, one was household section built by two columns with opposite polarities (col- umn VF-1301 ms and DB-5 ms) using retention index in different column systems as qualitative parameter, and the other was NIST MS search version 2.0. Meanwhile, the determination method of the 36 volatile solvents was developed with GC-MS. Cosmetic samples were dissolved in water and transferred to a headspace vial. After 30 min equilibration at 60 °C, the samples were analyzed by GC-MS equipped with a capillary chromatographic column VF-1301 ms. The external calibration was used for quantification. The limits of detection were from 0.01 to 3.3 μg/g, and the recoveries were from 60.77% to 126.6%. This study provided a generic method for pilot screening, identification, and quantitation of volatile organic solvents in cosmetics, and may solve the problem that different analytical methods need to be developed for different targeted compounds and pilot screening for potential candidate solvent residues.

  11. Organic matter and soil moisture content and double cropping with organic matter sourceplants

    Directory of Open Access Journals (Sweden)

    John Bako Baon

    2005-05-01

    Full Text Available Double cropping of coffee with organic matter source plants is thought to increase organic matter content of soil. This study examined the effect of double cropping of coffee and organic matter source plants on soil organic matter content and yield of coffee plants. Arabica coffee trees in Andungsari Experimental Station (Bondowoso district, 1400 m asl. and climate type C; and Robusta coffee trees in Sumberasin Experimental Station (Malang district, 550 m asl. and climate type C, were used as experimental sites of this study which lasted for five years. Organic matter source plants consisted of some species that can be routinedly pruned and surface applied to coffee soil, and other creeping species that not being pruned, however the organic matter source derived from their fallen leaves. Application of farm manure and control (neither organic matter source plants nor farm yard manure were used as comparison treatments. Results indicate that Ramayana (Cassia spectabilis had vigorus growth resulting in greater biomass production compared to lamtoro (Leucaena leucocephala, mogania (Moghania macrophylla and even kaliandra (Calyandra calothyrsus which produced greater biomass among organic matter source plants grown in Arabica coffee farming. Double cropping of coffee with organic matter source plants did not affect soil organic matter content of Arabica and Robusta coffee farmings, though farm yard manure application increased soil organic matter content and soil bulk density, especially of Robusta coffee farm. Soil moisture content examined in dry season was not affected by double cropping. In contrary, Robusta coffee farm applied with farm yard manure had higher soil moisture content. At Arabica coffee farm, double cropping did not influence green coffee yield, on the other hand Ramayana reduced green coffee yield of Robusta coffee while farm yard manure increased the yield.Keywords : Coffeea arabica, Coffeea canephora, organic matter, soil

  12. Volatile Organic Compound Emissions from Dairy Facilities in Central California

    Science.gov (United States)

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

    2011-12-01

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

  13. Secondary organic aerosols formed from oxidation of biogenic volatile organic compounds in the Sierra Nevada Mountains of California

    Science.gov (United States)

    Cahill, Thomas M.; Seaman, Vincent Y.; Charles, M. Judith; Holzinger, Rupert; Goldstein, Allen H.

    2006-08-01

    Biogenic volatile organic compound (BVOC) emissions, such as isoprene and terpenes, can be oxidized to form less volatile carbonyls, acids, and multifunctional oxygenated products that may condense to form secondary organic aerosols (SOA). This research was designed to assess the contribution of oxidized BVOC emissions to SOA in coniferous forests by collecting high-volume particulate samples for 6 days and 5 nights in the summer of 2003. The samples were analyzed for acids, carbonyls, polyols and alkanes to quantify oxidized BVOCs. Terpene and isoprene oxidation products were among the most abundant chemical species detected with the exception of hexadecanoic acid, octadecanoic acid and two butyl esters of unknown origin. The terpene oxidation products of pinonic acid, pinic acid, nopinone and pinonaldehyde showed clear diurnal cycles with concentrations two- to eight-fold higher at night. These cycles resulted from the diurnal cycles in gaseous terpene concentrations and lower temperatures that enhanced condensation of semivolatile chemicals onto aerosols. The terpene-derived compounds averaged 157 ± 118 ng/m3 of particulate organic matter while the isoprene oxidation compounds, namely the 2-methyltetrols and 2-methylglyceric acid, accounted for 53 ± 19 ng/m3. Together, the terpene and isoprene oxidation products represented 36.9% of the identified organic mass of 490 ± 95 ng/m3. PM10 organic matter loadings in the region were approximately 2.1 ± 1.2 μg/m3, so about 23% of the organic matter was identified and at least 8.6% was oxidized BVOCs. The BVOC oxidation products we measured were significant, but not dominant, contributors to the regional SOA only 75 km downwind of the Sacramento urban area.

  14. The Fate of Non-Volatile Organic Chemicals in The Agricultural Environment

    Directory of Open Access Journals (Sweden)

    Mohammad A. Batiha

    2007-01-01

    Full Text Available Multimedia dynamic model of the fate of non-volatile organic chemicals (NVOC in the agricultural environment is described. The modeled environment, consisting of up to three major surfaces environmental compartments, includes air, agricultural soil, and surface water. This model is based on the aquivalence approach suggested by Mackay and co-workers in 1989. As the movement of chemicals in the environment is closely associated with the movement of air, water and organic matter, the complete steady state mass budgets for air, water and particulate organic carbon (POC between the model compartments are described. All of the model equations, which are expressed in aquivalence notation, the mass balance for NVOC in the environmental surfaces compartments at dynamic state, and equations for the calculation of partitioning, overall persistence, total amount, total concentrations at dynamic state and intermedia fluxes of organic chemicals between air, water, and soil at steady-state are provided.

  15. Emission of Biogenic Volatile Organic Compounds in the Arctic

    DEFF Research Database (Denmark)

    Lindwall, Frida

    Emissions of biogenic volatile organic compounds (BVOCs) from arctic ecosystems are scarcely studied and the effect of climate change on BVOC emissions even less so. BVOCs are emitted from all living organisms and play a role for atmospheric chemistry. The major part of BVOCs derives from plants,......, arctic BVOC emissions will become more important for the global BVOC budget as well as for the regional climate due to the positive and negative climate warming feedbacks.......Emissions of biogenic volatile organic compounds (BVOCs) from arctic ecosystems are scarcely studied and the effect of climate change on BVOC emissions even less so. BVOCs are emitted from all living organisms and play a role for atmospheric chemistry. The major part of BVOCs derives from plants...... growing seasons, low temperatures and low statured plants, occurs at twice the speed of the global average. Changes in temperature and precipitation patterns have consequences for soil, plant species distribution, plant biomass and reproductive success. Emission and production of BVOCs are temperature...

  16. Soil organic matter in the Netherlands

    NARCIS (Netherlands)

    Conijn, J.G.; Lesschen, J.P.

    2015-01-01

    Soil organic matter (SOM) and especially decreasing SOM are since many decades on the agenda of different stakeholders due to the importance of SOM for various issues ranging from local crop profitability to global climate change. Globally large amounts of organic carbon are stored in the soil and

  17. Are Some Fungal Volatile Organic Compounds (VOCs) Mycotoxins?

    Science.gov (United States)

    Bennett, Joan W; Inamdar, Arati A

    2015-09-22

    Volatile organic compounds (VOCs) are carbon-compounds that easily evaporate at room temperature. Toxins are biologically produced poisons; mycotoxins are those toxins produced by microscopic fungi. All fungi emit blends of VOCs; the qualitative and quantitative composition of these volatile blends varies with the species of fungus and the environmental situation in which the fungus is grown. These fungal VOCs, produced as mixtures of alcohols, aldehydes, acids, ethers, esters, ketones, terpenes, thiols and their derivatives, are responsible for the characteristic moldy odors associated with damp indoor spaces. There is increasing experimental evidence that some of these VOCs have toxic properties. Laboratory tests in mammalian tissue culture and Drosophila melanogaster have shown that many single VOCs, as well as mixtures of VOCs emitted by growing fungi, have toxic effects. This paper describes the pros and cons of categorizing toxigenic fungal VOCs as mycotoxins, uses genomic data to expand on the definition of mycotoxin, and summarizes some of the linguistic and other conventions that can create barriers to communication between the scientists who study VOCs and those who study toxins. We propose that "volatoxin" might be a useful term to describe biogenic volatile compounds with toxigenic properties.

  18. Are Some Fungal Volatile Organic Compounds (VOCs Mycotoxins?

    Directory of Open Access Journals (Sweden)

    Joan W. Bennett

    2015-09-01

    Full Text Available Volatile organic compounds (VOCs are carbon-compounds that easily evaporate at room temperature. Toxins are biologically produced poisons; mycotoxins are those toxins produced by microscopic fungi. All fungi emit blends of VOCs; the qualitative and quantitative composition of these volatile blends varies with the species of fungus and the environmental situation in which the fungus is grown. These fungal VOCs, produced as mixtures of alcohols, aldehydes, acids, ethers, esters, ketones, terpenes, thiols and their derivatives, are responsible for the characteristic moldy odors associated with damp indoor spaces. There is increasing experimental evidence that some of these VOCs have toxic properties. Laboratory tests in mammalian tissue culture and Drosophila melanogaster have shown that many single VOCs, as well as mixtures of VOCs emitted by growing fungi, have toxic effects. This paper describes the pros and cons of categorizing toxigenic fungal VOCs as mycotoxins, uses genomic data to expand on the definition of mycotoxin, and summarizes some of the linguistic and other conventions that can create barriers to communication between the scientists who study VOCs and those who study toxins. We propose that “volatoxin” might be a useful term to describe biogenic volatile compounds with toxigenic properties.

  19. Volatile organic compounds in the unsaturated zone from radioactive wastes

    Science.gov (United States)

    Baker, Ronald J.; Andraski, Brian J.; Stonestrom, David A.; Luo, Wentai

    2012-01-01

    Volatile organic compounds (VOCs) are often comingled with low-level radioactive wastes (LLRW), but little is known about subsurface VOC emanations from LLRW landfills. The current study systematically quantified VOCs associated with LLRW over an 11-yr period at the USGS Amargosa Desert Research Site (ADRS) in southwestern Nevada. Unsaturated-zone gas samples of VOCs were collected by adsorption on resin cartridges and analyzed by thermal desorption and GC/MS. Sixty of 87 VOC method analytes were detected in the 110-m-thick unsaturated zone surrounding a LLRW disposal facility. Chlorofluorocarbons (CFCs) were detected in 100% of samples collected. Chlorofluorocarbons are powerful greenhouse gases, deplete stratospheric ozone, and are likely released from LLRW facilities worldwide. Soil-gas samples collected from a depth of 24 m and a horizontal distance 100 m south of the nearest waste-disposal trench contained >60,000 ppbv total VOCs, including >37,000 ppbv CFCs. Extensive sampling in the shallow unsaturated zone (0–2 m deep) identified areas where total VOC concentrations exceeded 5000 ppbv at the 1.5-m depth. Volatile organic compound concentrations exceeded background levels up to 300 m from the facility. Maximum vertical diffusive fluxes of total VOCs were estimated to be 1 g m-2 yr-1. Volatile organic compound distributions were similar but not identical to those previously determined for tritium and elemental mercury. To our knowledge, this study is the first to characterize the unsaturated zone distribution of VOCs emanating from a LLRW landfill. Our results may help explain anomalous transport of radionuclides at the ADRS and elsewhere.

  20. Water-Air Volatilization Factors to Determine Volatile Organic Compound (VOC Reference Levels in Water

    Directory of Open Access Journals (Sweden)

    Vicenç Martí

    2014-06-01

    Full Text Available The goal of this work is the modeling and calculation of volatilization factors (VFs from water to air for volatile organic compounds (VOCs in order to perform human health risk-based reference levels (RLs for the safe use of water. The VF models have been developed starting from the overall mass-transfer coefficients (Koverall concept from air to water for two interaction geometries (flat surface and spherical droplets in indoor and outdoor scenarios. For a case study with five groups of risk scenarios and thirty VOCs, theoretical VFs have been calculated by using the developed models. Results showed that Koverall values for flat and spherical surface geometries were close to the mass transfer coefficient for water (KL when Henry’s law constant (KH was high. In the case of spherical drop geometry, the fraction of volatilization (fV was asymptotical when increasing KH with fV values also limited due to Koverall. VFs for flat surfaces were calculated from the emission flux of VOCs, and results showed values close to 1000KH for the most conservative indoor scenarios and almost constant values for outdoor scenarios. VFs for spherical geometry in indoor scenarios followed also constant VFs and were far from 1000KH. The highest calculated VF values corresponded to the E2A, E2B, E3A and E5A scenarios and were compared with experimental and real results in order to check the goodness of flat and sphere geometry models. Results showed an overestimation of calculated values for the E2A and E2B scenarios and an underestimation for the E3A and E5A scenarios. In both cases, most of the calculated VFs were from 0.1- to 10-times higher than experimental/real values.

  1. Stability of volatile organics in environmental soil samples

    Energy Technology Data Exchange (ETDEWEB)

    Maskarinec, M.P.; Bayne, C.K.; Jenkins, R.A.; Johnson, L.H.; Holladay, S.K.

    1992-11-01

    This report focuses on data generated for the purpose of establishing the stability of 19 volatile organic compounds in environmental soil samples. The study was carried out over a 56 day (for two soils) and a 111 day (for one reference soil) time frame and took into account as many variables as possible within the constraints of budget and time. The objectives of the study were: 1) to provide a data base which could be used to provide guidance on pre-analytical holding times for regulatory purposes; and 2) to provide a basis for the evaluation of data which is generated outside of the currently allowable holding times.

  2. Stability of volatile organics in environmental soil samples. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Maskarinec, M.P.; Bayne, C.K.; Jenkins, R.A.; Johnson, L.H.; Holladay, S.K.

    1992-11-01

    This report focuses on data generated for the purpose of establishing the stability of 19 volatile organic compounds in environmental soil samples. The study was carried out over a 56 day (for two soils) and a 111 day (for one reference soil) time frame and took into account as many variables as possible within the constraints of budget and time. The objectives of the study were: 1) to provide a data base which could be used to provide guidance on pre-analytical holding times for regulatory purposes; and 2) to provide a basis for the evaluation of data which is generated outside of the currently allowable holding times.

  3. Volatile organic compound (VOC) emissions during malting and beer manufacture

    Science.gov (United States)

    Gibson, Nigel B.; Costigan, Gavin T.; Swannell, Richard P. J.; Woodfield, Michael J.

    Estimates have been made of the amounts of volatile organic compounds (VOCs) released during different stages of beer manufacture. The estimates are based on recent measurements and plant specification data supplied by manufacturers. Data were obtained for three main manufacturing processes (malting, wort processing and fermentation) for three commercial beer types. Some data on the speciation of emitted compounds have been obtained. Based on these measurements, an estimate of the total unabated VOC emission. from the U.K. brewing industry was calculated as 3.5 kta -1, over 95% of which was generated during barley malting. This value does not include any correction for air pollution control.

  4. Synthesis of Carbon Nanotubes and Volatile Organic Compounds Detection

    Directory of Open Access Journals (Sweden)

    Sobri S.

    2016-01-01

    Full Text Available In this work, the adsorption effect of volatile organic compounds (chloroacetophenone, acetonitrile and hexane towards the change of resistance of CNTs pellet as sensor signal was investigated. CNTs used in this research were synthesized using Floating Catalyst – Chemical Vapor Deposition (FC-CVD method in optimum condition. The synthesized CNTs were characterized using Scanning Electron Microscopy (SEM, Transmission Electron Microscopy (TEM and Raman Spectroscopy. The variation of resistance changes towards the tested gases were recorded using a multimeter. CNTs sensor pellet showed good responses towards the tested gases, however, the sensitivity, response time and recovery time of sensor pellet need to be optimized.

  5. Volatile organic compound emission profiles of four common arctic plants

    DEFF Research Database (Denmark)

    Vedel-Petersen, Ida; Schollert, Michelle; Nymand, Josephine;

    2015-01-01

    The biogenic volatile organic compound (BVOC) emissions from plants impact atmosphere and climate. The species-specific emissions, and thereby the atmospheric impact, of many plant species are still unknown. Knowledge of BVOC emission from arctic plants is particularly limited. The vast area...... and relatively high leaf temperature give the Arctic potential for emissions that cannot be neglected. This field study aimed to elucidate the BVOC emission profiles for four common arctic plant species in their natural environment during the growing season. BVOCs were sampled from aboveground parts of Empetrum...

  6. The sampling apparatus of volatile organic compounds for wood composites

    Institute of Scientific and Technical Information of China (English)

    SHENJun; ZHAOLin-bo; LIUYu

    2005-01-01

    Terpenes, aldehydes, ketones, benzene, and toluene are the important volatile organic compounds (VOCs) emitted from wood composites. A sampling apparatus of VOCs for wood composites was designed and manufactured by Northeast Forestry University in China.The concentration of VOCs derived from wood based materials, such as flooring, panel wall, finishing, and furniture can be sampled in a small stainless steel chambers. A protocol is also developed in this study to sample and measure the new and representative specimens. Preliminary research showed that the properties of the equipment have good stability. The sort and the amount of different components can be detected from it. The apparatus is practicable.

  7. Review on Volatile Organic Compounds Emission from Wood Composites

    Institute of Scientific and Technical Information of China (English)

    LIU Yu; YU Yaoming; SHEN Jun; LIU Ming

    2006-01-01

    The problem of indoor air quality (IAQ) is mainly caused by the volatile organic compounds (VOC) emission from the wood-based composites. As a material for decoration, furniture manufacturing or building, wood-based composite is one of the sources of VOC emissions. Most of them are formaldehyde, terpene, ketone and benzene. The paper reviews on VOC emission of wood-based composites at home and abroad, including the source of the VOC, its impacts on IAQ, its emission during processing and using, the usual sampling and analyse methods of VOC in different conditions. Meanwhile, main problems existed in the past researches are summarized and some suggestions are put forward.

  8. Sorption of Organic Compounds in Soil Organic Matter

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Soil organic matter (SOM)is the predominant component for sorption of hydrophobic organic compouds in soil and sorption by SOM ultimately affects chemical fate and availability in soil ,and the degree of remedia tion success of contaminated soils. This paper summarizes the latest development on sorption of organic com pounds in soil (natural) organic matter, addresses four sorption mechanisms: surface adsorption, solid - phase partitioning,dual-mode sorption,and fixed-pore sorption model ,and presents future research directions as well.

  9. Priming of Native Soil Organic Matter by Pyrogenic Organic Matter

    Science.gov (United States)

    DeCiucies, S.; Lehmann, J.; Woolf, D.; Whitman, T.

    2016-12-01

    Within the global carbon (C) cycle, soil C makes up a critical and active pool. Pyrogenic C, (PyC) or black C, contributes to this pool, and has been shown to change the turnover rate of the non-pyrogenic soil organic carbon (nSOC) associated with it. This change in rate of mineralization is referred to as priming, which can be negative or positive. There are many possible mechanisms that may be causing this priming effect, both biological and chemical. This study employs incubation experiments to identify and parse these potential mechanisms, focusing on negative priming mechanisms which may have importance in global carbon storage and carbon cycling models. Continuous respiration measurements of soil/char and soil/biomass incubations using isotopically labeled biomass (13C and 15N) indicate that priming interactions are more significant in soils with higher carbon contents, and that higher temperature chars induce more negative priming over time. Current incubations are exploring the effects of chars pyrolyzed at different temperatures, chars extracted of DOC versus non-extracted, soils with differing carbon contents, and the effects of pH and nutrient adjusting incubations. We will continue to examine the contribution of the different mechanisms by isolating variables such as nutrient addition, soil texture, char application rate, and mineral availability. We anticipate that sorption on PyOM surfaces are important in nSOM stabilization and will continue to study these effects using highly labeled substrates and nano secondary ion mass spectrometry (nano-SIMS).

  10. Volatile organic compounds associated with Plasmodium falciparum infection in vitro.

    Science.gov (United States)

    Correa, Ricardo; Coronado, Lorena M; Garrido, Anette C; Durant-Archibold, Armando A; Spadafora, Carmenza

    2017-05-02

    In order to identify new ways to prevent transmission of vector-borne diseases such as malaria, efforts have been made to understand how insects are attracted to humans. Vector-host interaction studies have shown that several volatile compounds play an important role in attracting mosquitoes to human targets. A headspace solid-phase micro-extraction/gas chromatography-mass spectrometry (HSPME GC-MS) analysis of the volatile organic composition of extracellular vesicles (EVs) and supernatants of ultracentrifugation (SNUs) was carried out in Plasmodium falciparum-infected cultures with high and low parasitemias. A list of 18 volatile organic compounds (VOCs) was obtained from the EVs of both infected and uninfected RBCs with 1,2,3-Propanetriol, diacetate (diacetin) increased in the infected EVs, regardless of the parasitemia of the culture. The supernatant analysis, however, gave off 56 VOCs, with pentane 2,2,4-trimethyl being present in all the SNUs of uninfected erythrocytes but absent from the parasite-infected ones. Standing out in this study was hexanal, a reported insect attractant, which was the only VOC present in all samples from SNUs from infected erythrocytes and absent from uninfected ones, suggesting that it originates during parasite infection. The hexanal compound, reportedly a low-level component found in healthy human samples such as breath and plasma, had not been found in previous analyses of P. falciparum-infected patients or cultures. This compound has been reported as an Anopheles gambiae attractant in plants. While the compound could be produced during infection by the malaria parasite in human erythrocytes, the A. gambiae attraction could be used by the parasite as a strategy for transmission.

  11. Evaporation of volatile organic compounds from human skin in vitro.

    Science.gov (United States)

    Gajjar, Rachna M; Miller, Matthew A; Kasting, Gerald B

    2013-08-01

    The specific evaporation rates of 21 volatile organic compounds (VOCs) from either human skin or a glass substrate mounted in modified Franz diffusion cells were determined gravimetrically. The diffusion cells were positioned either on a laboratory bench top or in a controlled position in a fume hood, simulating indoor and outdoor environments, respectively. A data set of 54 observations (34 skin and 20 glass) was assembled and subjected to a correlation analysis employing 5 evaporative mass transfer relationships drawn from the literature. Models developed by Nielsen et al. (Prediction of isothermal evaporation rates of pure volatile organic compounds in occupational environments: a theoretical approach based on laminar boundary layer theory. Ann Occup Hyg 1995;39:497-511.) and the U.S. Environmental Protection Agency (Peress, Estimate evaporative losses from spills. Chem Eng Prog 2003; April: 32-34.) were found to be the most effective at correlating observed and calculated evaporation rates under the various conditions. The U.S. EPA model was selected for further use based on its simplicity. This is a turbulent flow model based only on vapor pressure and molecular weight of the VOC and the effective air flow rate u. Optimum values of u for the two laboratory environments studied were 0.23 m s(-1) (bench top) and 0.92 m s(-1) (fume hood).

  12. Transport, behavior, and fate of volatile organic compounds in streams

    Science.gov (United States)

    Rathbun, R.E.

    2000-01-01

    Volatile organic compounds (VOCs) are compounds with chemical and physical properties that allow the compounds to move freely between the water and air phases of the environment. VOCs are widespread in the environment because of this mobility. Many VOCs have properties that make them suspected or known hazards to the health of humans and aquatic organisms. Consequently, understanding the processes affecting the concentration and distribution of VOCs in the environment is necessary. The transport, behavior, and fate of VOCs in streams are determined by combinations of chemical, physical, and biological processes. These processes are volatilization, absorption, wet and dry deposition, microbial degradation, sorption, hydrolysis, aquatic photolysis, oxidation, chemical reaction, biocon-centration, advection, and dispersion. The relative importance of each of these processes depends on the characteristics of the VOC and the stream. The U.S. Geological Survey National Water-Quality Assessment Program selected 55 VOCs for study. This article reviews the characteristics of the various processes that could affect the transport, behavior, and fate of these VOCs in streams.

  13. Organic Matter in the Contemporary Ocean

    Science.gov (United States)

    Eglinton, T. I.; Repeta, D. J.

    2003-12-01

    This chapter summarizes selected aspects of our current understanding of the organic carbon (OC) cycle as it pertains to the modern ocean, including underlying surficial sediments. We briefly review present estimates of the size of OC reservoirs and the fluxes between them. We then proceed to highlight advances in our understanding that have occurred since the late 1980s, especially those which have altered our perspective of the ways organic matter is cycled in the oceans. We have focused on specific areas where substantial progress has been made, although in most cases our understanding remains far from complete. These are the fate of terrigenous OC inputs in the ocean, the composition of oceanic dissolved organic matter (DOM), the mechanisms of OC preservation, and new insights into microbial inputs and processes. In each case, we discuss prevailing hypotheses concerning the composition and fate of organic matter derived from the different inputs, the reactivity and relationships between different organic matter pools, and highlight current gaps in our knowledge.The advances in our understanding of organic matter cycling and composition has stemmed largely from refinements in existing methodologies and the emergence of new analytical capabilities. Molecular-level stable carbon and nitrogen isotopic measurements have shed new light on a range of biogeochemical processes. Natural abundance of radiocarbon data has also been increasingly applied as both a tracer and source indicator in studies of organic matter cycling. As for 13C, bulk 14C measurements are now complemented by measurements at the molecular level, and the combination of these different isotopic approaches has proven highly informative. The application of multinuclear solid- and liquid-state nuclear magnetic resonance (NMR) spectroscopy has provided a more holistic means to examine the complex array of macromolecules that appears to comprise both dissolved and particulate forms of organic matter. New

  14. A Study of Thermal Analyses and Fundamental Combustion Characteristics for Thermal Utility with Biomass Volatile Matter

    Science.gov (United States)

    Ida, Tamio; Namba, Kunihiko; Sano, Hiroshi

    Based on un-use biomass utilities, Carbonized technology is noticed as material utilities and solid fuel. Therefore, this technology is tackling by national project as large-scale utilities. But, this technology is dehydrated volatiles matter during carbonized from biomass. Especially, Woody tar into one of volatile matter has vicious handling to get into trouble in carbonized equipment. In this study, we propose to get fundamental knowledge for effective thermal utility through thermal decompositions and fundamental combustion properties on experimental results. Woody tar has high caloric value (approximately 30MJ/kg) and high carbon ration. On the other hand, a woody vinegar liquid has thermal decomposition property close to water property with heat absorption as evaporation latent heat of water. In fundamental combustion experimental result, a woody tar has fl ammable combustion and surface combustion. Especially, a total combustion and ignition time properties has hyperbola relation to environment temperatures in furnace.

  15. Emission of Biogenic Volatile Organic Compounds in the Arctic

    DEFF Research Database (Denmark)

    Lindwall, Frida

    Emissions of biogenic volatile organic compounds (BVOCs) from arctic ecosystems are scarcely studied and the effect of climate change on BVOC emissions even less so. BVOCs are emitted from all living organisms and play a role for atmospheric chemistry. The major part of BVOCs derives from plants...... in the atmosphere. This may warm the climate due to a prolonged lifetime of the potent greenhouse gas methane in the atmosphere. However, oxidized BVOCs may participate in formation or growth of aerosols, which in turn may mitigate climate warming. Climate change in the Arctic, an area characterized by short...... dependent and the emissions will increase in a future warmer climate. The aims of this dissertation were to study BVOC emission rates and blends from arctic ecosystems and to reveal the effect of climate change on BVOC emissions from the Arctic. BVOC emissions were measured in ambient and modified...

  16. Cyclodextrin-based microsensors for volatile organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, B.; Johnson, S.; Shi, J.; Yang, Xiaoguang

    1997-10-01

    Host-guest chemistry and self-assembly techniques are being explored to develop species selective thin-films for real-time sensing of volatile organic compounds (VOCs). Cyclodextrin (CD) and calixarene (CA) molecules are known to form guest-host inclusion complexes with a variety of organic molecules. Through the control of the cavity size and chemical functionality on the rims of these bucket-like molecules, the binding affinities for formation of inclusion complexes can be controlled and optimized for specific agents. Self-assembly techniques are used to covalently bond these reagent molecules to the surface of acoustic transducers to create dense, highly oriented, and stable thin films. Self-assembly techniques have also been used to fabricate multilayer thin film containing molecular recognition reagents through alternating adsorption of charged species in aqueous solutions. Self-assembly of polymeric molecules of the SAW device was also explored for fabricating species selective interfaces.

  17. Organic matter stocks in temperate forest soil

    OpenAIRE

    Schöning, Ingo

    2006-01-01

    In temperate forests, more than 60% of the total carbon reserves are located in forest floor and mineral soil. The main objectives of this study were (1) to investigate the composition and radiocarbon age of organic matter (OM) pools of different stability in mineral soils, (2) to identify associations between iron oxides and specific carbon species, and (3) to analyse the small scale spatial variability of soil organic carbon (SOC) stocks. Composition, radiocarbon age and associations betwee...

  18. Soil architecture and distribution of organic matter

    NARCIS (Netherlands)

    Kooistra, M.J.; Noordwijk, van M.

    1996-01-01

    The biological component of soil structure varies greatly in quality and quantity, occurs on different scales, and varies throughout the year. It is far less predictable than the physical part and human impact. The occurrence and distribution of organic matter depends on several processes, related t

  19. Determination of organic chemicals in human whole blood: Preliminary method development for volatile organics

    Energy Technology Data Exchange (ETDEWEB)

    Cramer, P.H.; Boggess, K.E.; Hosenfeld, J.M. (Midwest Research Institute, Kansas City, MO (USA)); Remmers, J.C.; Breen, J.J.; Robinson, P.E.; Stroup, C. (Environmental Protection Agency, Washington, DC (USA))

    1988-05-01

    Extensive commercial, industrial, and domestic use of volatile organic chemicals, virtually assures that the general population will be exposed to some level of this class of chemicals. Because blood interacts with the respiratory system and is a major component of the body, it is likely that the analysis of blood will show exposure to volatile organics. Monitoring of the blood in conjunction with monitoring of xenobiotic levels in urine and adipose tissue is an effective way to assess the total body burden resulting from exposure to a chemical. This article introduces a method for the detection and confirmation of selected volatile organics at parts-per-trillion (ppt) levels in whole human blood. Intended for routine use, the method consists of a dynamic headspace purge of water-diluted blood where a carrier gas sweeps the surface of the sample and removes a quantifiable amount of the volatile organics from the blood and into an adsorbent trap. The organics are thermally desorbed from the adsorbent trap and onto the analytical column in a gas-chromatographic/mass-spectrometric (GC/MS) system where limited mass-scan data are taken for qualitative and quantitative identification. Method validation results and limited population-survey results are also presented here.

  20. 40 CFR 60.112b - Standard for volatile organic compounds (VOC).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds... organic compounds (VOC). (a) The owner or operator of each storage vessel either with a design capacity... for Volatile Organic Liquid Storage Vessels (Including Petroleum Liquid Storage Vessels) for...

  1. Development of novel biofilters for treatment of volatile organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, D.F. [Environmental Protection Agency, Cincinnati, OH (United States). National Risk Management Research Lab.; Govind, R. [Univ. of Cincinnati, OH (United States). Dept. of Chemical Engineering

    1995-12-31

    Biofiltration involves contacting a contaminated gas stream with immobilized microorganisms in a contactor to biodegrade the contaminants. It is emerging as an attractive technology for removing low concentrations (i.e., less than 800 ppmv) of volatile organic chemicals (VOCs) from air. Compared with other technologies, biofiltration fully mineralizes the contaminants, is inexpensive and reliable, and requires no posttreatment. In the study described in this paper, four types of media consisting of porous ceramic monoliths with several straight passages were studied to determine the effects of adsorptive and nonadsorptive media on biofilter startup time, dynamic response to step changes in inlet substrate concentration, biofilm adherence, and overall VOC-removal efficiency. Volatile compounds studied were benzene, toluene, ethylbenzene, m-xylene, and o-xylene. Adsorbing media such as activated carbon, when compared with nonadsorbing media such as ceramic, exhibit faster biofilter startup, are more stable to dynamic changes in inlet concentration, and attain higher VOC-removal efficiencies due to better adherence of biofilm on media surfaces.

  2. Biogenic Emissions of Volatile Organic Compounds by Urban Forests

    Institute of Scientific and Technical Information of China (English)

    CENTRITTOMauro; LIUShirong; LORETOFrancesco

    2005-01-01

    All plants emit a wide range of volatile compounds, the so-called biogenic volatile organic compounds (BVOC). BVOC emissions have received increased scientific attention in the last two decades because they may profoundly influence the chemical and physical properties of the atmosphere, and may modulate plant tolerance to heat, pollutants, oxidative stress and abiotic stresses, and affect plant-plant and plant-insect interactions. Urban forestry may have a high impact on atmospheric composition, air quality, environment,and quality of life in urban areas. However, few studies have been carried out where the emission of BVOC could have important consequence for the quality of air and contribute to pollution episodes. A screening of BVOC emission by the mixed stand constituting urban forests is therefore required if emissions are to be reliably predicted. Monitoring the emission rates simultaneously with measurements of air quality, plant physiology and micrometeorology on selected urban forests, will allow detailed quantitative information on the inventory of BVOC emissions by urban vegetation to be compiled. This information will make it possible to propose an innovative management of urban vegetation in cities characterised by heavy emissions of anthropogenic pollutants, aiming at the abatement of BVOC emissions through the introduction or selection of non-BVOC emitting species in urban areas subjected to pollution episodes and in the new afforestation areas covering peri-urban parks, green belts and green corridors between peri-urban rural areas and the conurbations.

  3. First Characterisation of Volatile Organic Compounds Emitted by Banana Plants.

    Science.gov (United States)

    Berhal, Chadi; De Clerck, Caroline; Fauconnier, Marie-Laure; Levicek, Carolina; Boullis, Antoine; Kaddes, Amine; Jijakli, Haïssam M; Verheggen, François; Massart, Sébastien

    2017-05-16

    Banana (Musa sp.) ranks fourth in term of worldwide fruit production, and has economical and nutritional key values. The Cavendish cultivars correspond to more than 90% of the production of dessert banana while cooking cultivars are widely consumed locally around the banana belt production area. Many plants, if not all, produce Volatile Organic Compounds (VOCs) as a means of communication with their environment. Although flower and fruit VOCs have been studied for banana, the VOCs produced by the plant have never been identified despite their importance in plant health and development. A volatile collection methodology was optimized to improve the sensitivity and reproducibility of VOCs analysis from banana plants. We have identified 11 VOCs for the Cavendish, mainly (E,E)-α-farnesene (87.90 ± 11.28 ng/μl), methyl salicylate (33.82 ± 14.29) and 6-methyl-5-hepten-2-one (29.60 ± 11.66), and 14 VOCs for the Pacific Plantain cultivar, mainly (Z,E)-α-farnesene (799.64 ± 503.15), (E,E)-α-farnesene (571.24 ± 381.70) and (E) β ocimene (241.76 ± 158.49). This exploratory study paves the way for an in-depth characterisation of VOCs emitted by Musa plants.

  4. Wildlife ecological screening levels for inhalation of volatile organic chemicals.

    Science.gov (United States)

    Gallegos, Patricia; Lutz, Jill; Markwiese, James; Ryti, Randall; Mirenda, Rich

    2007-06-01

    For most chemicals, evaluation of ecological risk typically does not address inhalation because ingestion dominates exposure. However, burrowing ecological receptors have an increased exposure potential from inhalation at sites contaminated with volatile chemicals in the subsurface. Evaluation of ecological risk from contaminants like volatile organic chemicals (VOCs) is constrained by a lack of relevant ecological screening levels (ESLs). To address this need, inhalation ESLs were developed for 16 VOCs: Acetone, benzene, carbon tetrachloride, chloroform, chloromethane, dichlorodifluoromethane, 1,1-dichloroethane, 1,2-dichloroethane, 1,1-dichloroethene, methylene chloride, tetrachloroethene, toluene, 1,1,1-trichloroethane, trichloroethene, trichlorofluoromethane, and total xylene. These ESLs are based on Botta's pocket gopher (Thomomys bottae) as a representative fossorial receptor. The ESLs are presented with an emphasis on the process for developing inhalation toxicity reference values to illustrate the selection of suitable toxicity data and effect levels from the literature. The resulting ESLs provide a quantitative method for evaluating ecological risk of VOCs through comparison to relevant exposure data such as direct burrow-air measurements. The toxicity reference value development and ESL calculation processes and assumptions detailed here are provided as bases from which risk assessors can use or refine to suit site-specific needs with respect to toxicity and exposure inputs.

  5. Volatile organic compound emissions from Larrea tridentata (creosotebush)

    Science.gov (United States)

    Jardine, K.; Abrell, L.; Kurc, S. A.; Huxman, T.; Ortega, J.; Guenther, A.

    2010-12-01

    We present results from the CREosote ATmosphere Interactions through Volatile Emissions (CREATIVE 2009) field study in southern Arizona aimed at quantifying emission rates of VOCs from creosotebush (Larrea tridentata) during the summer 2009 monsoon season. This species was chosen because of its vast distribution in North and South American deserts and because its resins have been reported to contain a rich set of volatile organic compounds (VOC). While a variety of ecosystems have been investigated for VOC emissions, deserts remain essentially unstudied, partially because of their low biomass densities and water limitations. However, during the North American monsoon, a pronounced increase in rainfall from an extremely dry June (80 mm) occurs over large areas of the Sonoran desert in the southwestern United States and northwestern Mexico. We observed a strong diurnal pattern of branch emissions and ambient concentrations of an extensive suite of VOCs with maxima in early afternoon. These include VOCs typically observed in forest sites (oxygenated VOCs and volatile isoprenoids) as well as a large number of other compounds, some of which have not been previously described from any plant including 1-chloro-2-methoxy-benzene and isobutyronitrile. Although generally considered to be derived from anthropogenic sources, we observed emissions of aromatic compounds including benzene, and a broad range of phenolics. Dimethyl sulfide emissions from creosotebush were higher than reported from any previously studied plant suggesting that terrestrial ecosystems should be reconsidered as an important source of this climatically important gas. We also present direct, primary emission measurements of isoprene and its apparent oxidation products methyl vinyl ketone, methacrolein, and 3-methyl furan (the later three compounds are typically assumed to form from secondary reactions within the atmosphere), as well as a group of compounds considered to be fatty acid oxidation products

  6. Volatile organic compound emissions from Larrea tridentata (creosotebush

    Directory of Open Access Journals (Sweden)

    J. Ortega

    2010-07-01

    Full Text Available The emission of Volatile Organic Compounds (VOCs from plants impacts both climate and air quality by fueling atmospheric chemistry and by contributing to aerosol particles. While a variety of ecosystems have been investigated for VOC emissions, deserts remain essentially unstudied, partially because of their low biomass densities and water limitations. However, during the North American monsoon, a pronounced increase in rainfall from an extremely dry June (<5 mm precipitation to a rainy July (>80 mm occurs over large areas of the Sonoran desert in the Southwestern United States and Northwestern Mexico. We present results from the CREosote ATmosphere Interactions through Volatile Emissions (CREATIVE 2009 field study in Southern Arizona aimed at quantifying emission rates of VOCs from creosotebush (Larrea tridentata during the summer 2009 monsoon season. This species was chosen because of its vast distribution in North and South American deserts and because its resins have been reported to contain a rich set of VOCs. We observed a strong diurnal pattern with branch emissions and ambient concentrations of an extensive suite of VOCs with maxima in early afternoon. These include VOCs typically observed in forest sites (oxygenated VOCs and volatile isoprenoids as well as a large number of other compounds, some of which have not been previously described from any plant including 1-chloro-2-methoxy-benzene and isobutyronitrile. Although generally considered to be derived from anthropogenic sources, we observed emissions of aromatic compounds including benzene, and a broad range of phenolics. Dimethyl sulfide emissions from creosotebush were higher than reported from any previously studied plant suggesting that terrestrial ecosystems should be reconsidered as an important source of this climatically important gas. We also present direct, primary emission measurements of isoprene and its apparent oxidation products methyl vinyl ketone, methacrolein, and 3

  7. Volatile organic compound emissions from Larrea tridentata (creosotebush

    Directory of Open Access Journals (Sweden)

    A. Guenther

    2010-12-01

    Full Text Available We present results from the CREosote ATmosphere Interactions through Volatile Emissions (CREATIVE 2009 field study in southern Arizona aimed at quantifying emission rates of VOCs from creosotebush (Larrea tridentata during the summer 2009 monsoon season. This species was chosen because of its vast distribution in North and South American deserts and because its resins have been reported to contain a rich set of volatile organic compounds (VOC. While a variety of ecosystems have been investigated for VOC emissions, deserts remain essentially unstudied, partially because of their low biomass densities and water limitations. However, during the North American monsoon, a pronounced increase in rainfall from an extremely dry June (80 mm occurs over large areas of the Sonoran desert in the southwestern United States and northwestern Mexico. We observed a strong diurnal pattern of branch emissions and ambient concentrations of an extensive suite of VOCs with maxima in early afternoon. These include VOCs typically observed in forest sites (oxygenated VOCs and volatile isoprenoids as well as a large number of other compounds, some of which have not been previously described from any plant including 1-chloro-2-methoxy-benzene and isobutyronitrile. Although generally considered to be derived from anthropogenic sources, we observed emissions of aromatic compounds including benzene, and a broad range of phenolics. Dimethyl sulfide emissions from creosotebush were higher than reported from any previously studied plant suggesting that terrestrial ecosystems should be reconsidered as an important source of this climatically important gas. We also present direct, primary emission measurements of isoprene and its apparent oxidation products methyl vinyl ketone, methacrolein, and 3-methyl furan (the later three compounds are typically assumed to form from secondary reactions within the atmosphere, as well as a group of compounds considered to be fatty acid

  8. Development and mining of a volatile organic compound database.

    Science.gov (United States)

    Abdullah, Azian Azamimi; Altaf-Ul-Amin, Md; Ono, Naoaki; Sato, Tetsuo; Sugiura, Tadao; Morita, Aki Hirai; Katsuragi, Tetsuo; Muto, Ai; Nishioka, Takaaki; Kanaya, Shigehiko

    2015-01-01

    Volatile organic compounds (VOCs) are small molecules that exhibit high vapor pressure under ambient conditions and have low boiling points. Although VOCs contribute only a small proportion of the total metabolites produced by living organisms, they play an important role in chemical ecology specifically in the biological interactions between organisms and ecosystems. VOCs are also important in the health care field as they are presently used as a biomarker to detect various human diseases. Information on VOCs is scattered in the literature until now; however, there is still no available database describing VOCs and their biological activities. To attain this purpose, we have developed KNApSAcK Metabolite Ecology Database, which contains the information on the relationships between VOCs and their emitting organisms. The KNApSAcK Metabolite Ecology is also linked with the KNApSAcK Core and KNApSAcK Metabolite Activity Database to provide further information on the metabolites and their biological activities. The VOC database can be accessed online.

  9. Lability of Secondary Organic Particulate Matter

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Pengfei; Li, Yong Jie; Wang, Yan; Giles, Mary K.; Zaveri, Rahul A.; Bertram, Allan K.; Martin, Scot T.

    2016-10-24

    Accurate simulations of the consenctrations of atmospheric organic particulate matter (PM) are needed for predicting energy flow in the Earth’s climate system. In the past, simulations of organic PM widely assume equilibrium partitioning of semivolatile organic compounds (SVOCs) between the PM and surrounding vapor. Herein, we test this assumption by measuring evaporation rates and associated vapor mass concentration of organic films representative of atmospheric PM. For films representing anthropogenic PM, evaporation rates and vapor mass concentrations increased above a threshold relative humidity (RH), indicating equilibrium partitioning above a transition RH but not below. In contrast for films representing biogenic PM, no threshold was observed, indicating equilibrium partitioning at all RHs. The results suggest that the mass lability of atmospheric organic PM can differ in consequential ways among Earth’s natural biomes, polluted regions, and regions of land-use change, and these differences need to be considered when simulating atmospheric organic PM.

  10. Catabolism of volatile organic compounds influences plant survival.

    Science.gov (United States)

    Oikawa, Patricia Y; Lerdau, Manuel T

    2013-12-01

    Plants emit a diverse array of phytogenic volatile organic compounds (VOCs). The production and emission of VOCs has been an important area of research for decades. However, recent research has revealed the importance of VOC catabolism by plants and VOC degradation in the atmosphere for plant growth and survival. Specifically, VOC catabolism and degradation have implications for plant C balance, tolerance to environmental stress, plant signaling, and plant-atmosphere interactions. Here we review recent advances in our understanding of VOC catabolism and degradation, propose experiments for investigating VOC catabolism, and suggest ways to incorporate catabolism into VOC emission models. Improving our knowledge of VOC catabolism and degradation is crucial for understanding plant metabolism and predicting plant survival in polluted environments.

  11. [Binding of Volatile Organic Compounds to Edible Biopolymers].

    Science.gov (United States)

    Misharina, T A; Terenina, M B; Krikunova, N I; Medvedeva, I B

    2016-01-01

    Capillary gas chromatography was used to study the influence of the composition and structure of different edible polymers (polysaccharides, vegetable fibers, and animal protein gelatin) on the binding of essential oil components. The retention of volatile organic compounds on biopolymers was shown to depend on their molecule structure and the presence, type, and position of a functional group. The maximum extent of the binding was observed for nonpolar terpene and sesquiterpene hydrocarbons, and the minimum extent was observed for alcohols. The components of essential oils were adsorbed due mostly to hydrophobic interactions. It was shown that the composition and structure of a compound, its physico-chemical state, and the presence of functional groups influence the binding. Gum arabic and guar gum were found to bind nonpolar compounds to a maximum and minimum extent, respectively. It was demonstrated the minimum adsorption ability of locust bean gum with respect to all studied compounds.

  12. Study on Volatile Organic Components from Chinese Fir Wood

    Institute of Scientific and Technical Information of China (English)

    HUANG Luohua; QIN Tefu; OHIRA Tatsuro

    2006-01-01

    The volatile organic compounds(VOCs) are emitted by a wide array of products, which include a variety of chemicals, some of them may have short- and long-term adverse health effects. Several analytical instrument including gas chromatograph, high preferment liquid chromatograph, mass spectrometry and solid phase microextraction (SPME) technique were used in this study. The results showed the aldehyde and ketone components of Chinese fir wood were little composed of formaldehyde, syn-acetaldehyde, anti-acetadehyde and acrolein, VOCs obtained by Tenax GR absorber consisted of the major component cedrene (42.92%) and another 28 components, and the major components of the VOCs from the sample by using solid phase microextraction (SPME) technique were cedrene and cedrol.

  13. Emissions of biogenic volatile organic compounds & their photochemical transformation

    Science.gov (United States)

    Yu, Zhujun; Hohaus, Thorsten; Tillmann, Ralf; Andres, Stefanie; Kuhn, Uwe; Rohrer, Franz; Wahner, Andreas; Kiendler-Scharr, Astrid

    2015-04-01

    Natural and anthropogenic activities emit volatile organic compounds (VOC) into the atmosphere. While it is known that land vegetation accounts for 90% of the global VOC emissions, only a few molecules' emission factors are understood. Through VOCs atmospheric oxidation intermediate products are formed. The detailed chemical mechanisms involved are insufficiently known to date and need to be understood for air quality management and climate change predictions. In an experiment using a PTR-ToF-MS with the new-built plant chamber SAPHIR-PLUS in Forschungszentrum Juelich, biogenic emissions of volatile organic compounds (BVOC) from Quercus ilex trees were measured. The BVOC emissions were dominated by monoterpenes, minor emissions of isoprene and methanol were also observed with the overall emission pattern typical for Quercus ilex trees in the growing season. Monoterpenes and isoprene emissions showed to be triggered by light. Additionally, their emissions showed clear exponential temperature dependence under constant light condition as reported in literature. As a tracer for leaf growth, methanol emission showed an abrupt increase at the beginning of light exposure. This is explained as instantaneous release of methanol produced during the night once stomata of leaves open upon light exposure. Emission of methanol showed a near linear increase with temperature in the range of 10 to 35 °C. BVOC were transferred from the plant chamber PLUS to the atmospheric simulation chamber SAPHIR, where their oxidation products from O3 oxidation were measured with PTR-ToF-MS. Gas phase oxidation products such as acetone and acetaldehyde were detected. A quantitative analysis of the data will be presented, including comparison of observations to the Master Chemical Mechanism model.

  14. Crude glycerol combustion: Particulate, acrolein, and other volatile organic emissions

    KAUST Repository

    Steinmetz, Scott

    2013-01-01

    Crude glycerol is an abundant by-product of biodiesel production. As volumes of this potential waste grow, there is increasing interest in developing new value added uses. One possible use, as a boiler fuel for process heating, offers added advantages of energy integration and fossil fuel substitution. However, challenges to the use of crude glycerol as a boiler fuel include its low energy density, high viscosity, and high autoignition temperature. We have previously shown that a refractory-lined, high swirl burner can overcome challenges related to flame ignition and stability. However, critical issues related to ash behavior and the possible formation of acrolein remained. The work presented here indicates that the presence of dissolved catalysts used during the esterification and transesterification processes results in extremely large amounts of inorganic species in the crude glycerol. For the fuels examined here, the result is a submicron fly ash comprised primarily of sodium carbonates, phosphates, and sulfates. These particles report to a well-developed accumulation mode (0.3-0.7 μm diameter), indicating extensive ash vaporization and particle formation via nucleation, condensation, and coagulation. Particle mass emissions were between 2 and 4 g/m3. These results indicate that glycerol containing soluble catalyst is not suitable as a boiler fuel. Fortunately, process improvements are currently addressing this issue. Additionally, acrolein is of concern due to its toxicity, and is known to be formed from the low temperature thermal decomposition of glycerol. Currently, there is no known reliable method for measuring acrolein in sources. Acrolein and emissions of other volatile organic compounds were characterized through the use of a SUMMA canister-based sampling method followed by GC-MS analysis designed for ambient measurements. Results indicate crude glycerol combustion produces relatively small amounts of acrolein (∼15 ppbv) and other volatile organic

  15. MATRIX-VBS: implementing an evolving organic aerosol volatility in an aerosol microphysics model

    OpenAIRE

    Gao, Chloe Y.; Tsigaridis, Kostas; Bauer, Susanne E.

    2016-01-01

    We have implemented an existing aerosol microphysics scheme into a box model framework and extended it to represent gas-particle partitioning and chemical ageing of semi-volatile organic aerosols. We then applied this new research tool to investigate the effects of semi-volatile organic species on the growth, composition and mixing state of aerosol particles in case studies representing several different environments. The volatility-basis set (VBS) framework is implemented into the aerosol mi...

  16. Influence of ventilation type in volatile organic compounds exposure: poultry case

    OpenAIRE

    Viegas, Susana; Monteiro, ANA; Manteigas, Vítor; Carolino, Elisabete; Viegas, Carla

    2012-01-01

    Agricultural workers especially poultry farmers are at increased risk of occupational respiratory diseases. Epidemiological studies showed increased prevalence of respiratory symptoms and adverse changes in pulmonary function parameters in poultry workers. In poultry production volatile organic compounds (VOCs) presence can be due to some compounds produced by molds that are volatile and are released directly into the air. These are known as microbial volatile organic compounds (MVOCs). Be...

  17. Analysis of Organic matter from cloud particles

    Science.gov (United States)

    Bank, Shelton; Castillo, Raymond

    1987-03-01

    Organic matter collected from filtration of two separate cloud events was analysed by Fourier Transform Infrared Spectroscopy. Particles collected from different size filters were separated by color and each type of particle gave rise to a characteristic spectrum. The major constituents were identified as complex proteins and cellulose. Additionally, some degraded material (likely protein) and an unidentified orange-brown material were present. Finally some trace components were identified as wax, oil, silicon oil, polyvinyl chloride, calcium carbonate, clay, sand and polyethylene.

  18. Organic matter matters for ice nuclei of agricultural soil origin

    Directory of Open Access Journals (Sweden)

    Y. Tobo

    2014-04-01

    Full Text Available Heterogeneous ice nucleation is a~crucial process for forming ice-containing clouds and subsequent ice-induced precipitation. The importance for ice nucleation of airborne desert soil dusts composed predominantly of minerals is relatively well understood. On the other hand, the potential influence of agricultural soil dusts on ice nucleation has been poorly recognized, despite recent estimates that they may account for up to ∼25% of the global atmospheric dust load. We have conducted freezing experiments with various dusts, including agricultural soil dusts derived from the largest dust source region in North America. Here we show evidence for the significant role of soil organic matter (SOM in particles acting as ice nuclei (IN under mixed-phase cloud conditions. We find that the ice nucleating ability of the agricultural soil dusts is similar to that of desert soil dusts, but is reduced to almost the same level as that of clay minerals (e.g., kaolinite after either H2O2 digestion or dry heating to 300 °C. In addition, based on chemical composition analysis, we show that organic-rich particles are more important than mineral particles for the ice nucleating ability of the agricultural soil dusts at temperatures warmer than about −36 °C. Finally, we suggest that such organic-rich particles of agricultural origin (namely, SOM particles may contribute significantly to the ubiquity of organic-rich IN in the global atmosphere.

  19. 40 CFR 60.112a - Standard for volatile organic compounds (VOC).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds (VOC). 60.112a Section 60.112a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Commenced After May 18, 1978, and Prior to July 23, 1984 § 60.112a Standard for volatile organic...

  20. 40 CFR 60.542a - Alternate standard for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

    ... Rubber Tire Manufacturing Industry § 60.542a Alternate standard for volatile organic compounds. (a) On... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Alternate standard for volatile organic compounds. 60.542a Section 60.542a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  1. 40 CFR 60.312 - Standard for volatile organic compounds (VOC).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds (VOC). 60.312 Section 60.312 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Surface Coating of Metal Furniture § 60.312 Standard for volatile organic compounds (VOC). (a) On...

  2. 40 CFR 60.112 - Standard for volatile organic compounds (VOC).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds (VOC). 60.112 Section 60.112 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... After June 11, 1973, and Prior to May 19, 1978 § 60.112 Standard for volatile organic compounds...

  3. 75 FR 57412 - Approval and Promulgation of Implementation Plans Alabama: Volatile Organic Compounds

    Science.gov (United States)

    2010-09-21

    ... ``volatile organic compounds'' (VOCs) found at Alabama Administrative Code section 335-3-1-.02(gggg... AGENCY 40 CFR Part 52 Approval and Promulgation of Implementation Plans Alabama: Volatile Organic Compounds AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing...

  4. 75 FR 82363 - Approval and Promulgation of Implementation Plans; Ohio; Volatile Organic Compound Emission...

    Science.gov (United States)

    2010-12-30

    ... AGENCY 40 CFR Part 52 Approval and Promulgation of Implementation Plans; Ohio; Volatile Organic Compound... printing volatile organic compound (VOC) rule for approval into the Ohio State Implementation Plan (SIP... mercury at 20 degrees Celsius. This rule also contains the appropriate test methods ] for determining...

  5. 40 CFR Table 2 to Subpart II of... - Volatile Organic HAP (VOHAP) Limits for Marine Coatings

    Science.gov (United States)

    2010-07-01

    ... (Surface Coating) Pt. 63, Subpt. II, Table 2 Table 2 to Subpart II of Part 63—Volatile Organic HAP (VOHAP... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Volatile Organic HAP (VOHAP) Limits for Marine Coatings 2 Table 2 to Subpart II of Part 63 Protection of Environment...

  6. Peer reviewed: Characterizing aquatic dissolved organic matter

    Science.gov (United States)

    Leenheer, Jerry A.; Croué, Jean-Philippe

    2003-01-01

    Whether it causes aesthetic concerns such as color, taste, and odor; leads to the binding and transport of organic and inorganic contaminants; produces undesirable disinfection byproducts; provides sources and sinks for carbon; or mediates photochemical processes, the nature and properties of dissolved organic matter (DOM) in water are topics of significant environmental interest. DOM is also a major reactant in and product of biogeochemical processes in which the material serves as a carbon and energy source for biota and controls levels of dissolved oxygen, nitrogen, phosphorus, sulfur, numerous trace metals, and acidity.

  7. Microlayer source of oxygenated volatile organic compounds in the summertime marine Arctic boundary layer

    Science.gov (United States)

    Mungall, Emma L.; Abbatt, Jonathan P. D.; Wentzell, Jeremy J. B.; Lee, Alex K. Y.; Thomas, Jennie L.; Blais, Marjolaine; Gosselin, Michel; Miller, Lisa A.; Papakyriakou, Tim; Willis, Megan D.; Liggio, John

    2017-06-01

    Summertime Arctic shipboard observations of oxygenated volatile organic compounds (OVOCs) such as organic acids, key precursors of climatically active secondary organic aerosol (SOA), are consistent with a novel source of OVOCs to the marine boundary layer via chemistry at the sea surface microlayer. Although this source has been studied in a laboratory setting, organic acid emissions from the sea surface microlayer have not previously been observed in ambient marine environments. Correlations between measurements of OVOCs, including high levels of formic acid, in the atmosphere (measured by an online high-resolution time-of-flight mass spectrometer) and dissolved organic matter in the ocean point to a marine source for the measured OVOCs. That this source is photomediated is indicated by correlations between the diurnal cycles of the OVOC measurements and solar radiation. In contrast, the OVOCs do not correlate with levels of isoprene, monoterpenes, or dimethyl sulfide. Results from box model calculations are consistent with heterogeneous chemistry as the source of the measured OVOCs. As sea ice retreats and dissolved organic carbon inputs to the Arctic increase, the impact of this source on the summer Arctic atmosphere is likely to increase. Globally, this source should be assessed in other marine environments to quantify its impact on OVOC and SOA burdens in the atmosphere, and ultimately on climate.

  8. Catalytic oxidation of volatile organic compounds (VOCs) - A review

    Science.gov (United States)

    Kamal, Muhammad Shahzad; Razzak, Shaikh A.; Hossain, Mohammad M.

    2016-09-01

    Emission of volatile organic compounds (VOCs) is one of the major contributors to air pollution. The main sources of VOCs are petroleum refineries, fuel combustions, chemical industries, decomposition in the biosphere and biomass, pharmaceutical plants, automobile industries, textile manufacturers, solvents processes, cleaning products, printing presses, insulating materials, office supplies, printers etc. The most common VOCs are halogenated compounds, aldehydes, alcohols, ketones, aromatic compounds, and ethers. High concentrations of these VOCs can cause irritations, nausea, dizziness, and headaches. Some VOCs are also carcinogenic for both humans and animals. Therefore, it is crucial to minimize the emission of VOCs. Among the available technologies, the catalytic oxidation of VOCs is the most popular because of its versatility of handling a range of organic emissions under mild operating conditions. Due to that fact, there are numerous research initiatives focused on developing advanced technologies for the catalytic destruction of VOCs. This review discusses recent developments in catalytic systems for the destruction of VOCs. Review also describes various VOCs and their sources of emission, mechanisms of catalytic destruction, the causes of catalyst deactivation, and catalyst regeneration methods.

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

    Science.gov (United States)

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

    2013-11-01

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

  10. Spectroscopic characterization of dissolved organic matter isolated from rainwater.

    Science.gov (United States)

    Santos, Patrícia S M; Otero, Marta; Duarte, Regina M B O; Duarte, Armando C

    2009-02-01

    Rainwater is a matrix containing extremely low concentrations (in the range of muM C) of dissolved organic carbon (DOC) and for its characterization, an efficient extraction procedure is essential. A recently developed procedure based on adsorption onto XAD-8 and XAD-4 resins in series was used in this work for the extraction and isolation of rainwater dissolved organic matter (DOM). Prior to the isolation and fractionation of DOM, and to obtain sufficient mass for the spectroscopic analyses, individual rainwater samples were batched together according to similar meteorological conditions on a total of three composed samples. The results of the isolation procedure indicated that the resin tandem procedure is not applicable for rainwater DOM since the XAD-4 resin caused samples contamination. On the other hand, the XAD-8 resin allowed DOM recoveries of 39.9-50.5% of the DOC of the original combined samples. This recovered organic fraction was characterized by UV-visible, molecular fluorescence, FTIR-ATR and 1H NMR spectroscopies. The chemical characterization of the rainwater DOM showed that the three samples consist mostly of hydroxylated and carboxylic acids with a predominantly aliphatic character, containing a minor component of aromatic structures. The obtained results suggest that the DOM in rainwater, and consequently in the precursor atmospheric particles, may have a secondary origin via the oxidation of volatile organic compounds from different origins.

  11. 77 FR 38725 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Volatile Organic...

    Science.gov (United States)

    2012-06-29

    ... Organic Compounds; Consumer Products AGENCY: Environmental Protection Agency (EPA). ACTION: Direct final... more stringent than, EPA's national consumer products rule, ``National Volatile Organic Compound... requirement for floor wax strippers that ensures that product packaging clearly indicates ``light/medium''...

  12. The Decompositioning of Volatile-Matter of Tanjung Enim Coal by using Thermogravimetry Analyzer (TGA

    Directory of Open Access Journals (Sweden)

    Nukman Nukman

    2010-10-01

    Full Text Available Coal is a nature material which a kind of energy source. The decompotition of coal could analyze by heat treated using thermogravimetry analyzer. The decomposition of the volatile matter for three kinds of Tanjung Enim coal could be known. The value of activation energy that be found diference, then for Semi Anthracite, Bitumonius and Sub Bituminous Coal, the initial temperatures are 60.8 oC, 70.7 oC, 97.8oC, and the last temperatures are 893.8 oC, 832 oC, 584.6oC.

  13. Datasets used in the manuscript titled "Nitrate radicals and biogenic volatile organic compounds: oxidation, mechanisms and organic aerosol"

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset documents that all of the data used in the manuscript "Nitrate radicals and biogenic volatile organic compounds: oxidation, mechanisms, and organic...

  14. Influence of volatile organic compounds of varnish-and-paint materials on the workers organism on the industrial enterprises

    Directory of Open Access Journals (Sweden)

    Г.І. Архіпова

    2010-02-01

    Full Text Available In article describes the reasons of air contamination in working area of endustrial enterprises, defines main ways of incoming and mechanism of action of volatile organic compounds of paintwork material on the organisms of workers.

  15. Repeated application of organic waste affects soil organic matter composition

    DEFF Research Database (Denmark)

    Peltre, Clément; Gregorich, Edward G.; Bruun, Sander

    2017-01-01

    of different types of carbon compounds in soil. The objective of this study was to identify and characterise changes in soil organic matter (SOM) composition after repeated applications of organic waste. Soil from the CRUCIAL field experiment in Denmark was sampled after 12 years of annual application...... that there was accumulation in soil of different C compounds for the different types of applied organic waste, which appeared to be related to the degree to which microbial activity was stimulated and the type of microbial communities applied with the wastes or associated with the decomposition of applied wastes...

  16. Clay-associated organic matter in kaolinitic and smectitic soils

    NARCIS (Netherlands)

    Wattel-Koekkoek, E.J.W.

    2002-01-01

    The primary source of soil organic matter is plant debris of all kinds, such as dead roots, leaves and branches that enter into the soil and are then biologically decomposed at variable rates. Organic matter has many different important functions on a local and global scale. Soil organic matter is a

  17. Clay-associated organic matter in kaolinitic and smectitic soils

    NARCIS (Netherlands)

    Wattel-Koekkoek, E.J.W.

    2002-01-01

    The primary source of soil organic matter is plant debris of all kinds, such as dead roots, leaves and branches that enter into the soil and are then biologically decomposed at variable rates. Organic matter has many different important functions on a local and global scale. Soil organic matter is a

  18. Abiotic Bromination of Soil Organic Matter.

    Science.gov (United States)

    Leri, Alessandra C; Ravel, Bruce

    2015-11-17

    Biogeochemical transformations of plant-derived soil organic matter (SOM) involve complex abiotic and microbially mediated reactions. One such reaction is halogenation, which occurs naturally in the soil environment and has been associated with enzymatic activity of decomposer organisms. Building on a recent finding that naturally produced organobromine is ubiquitous in SOM, we hypothesized that inorganic bromide could be subject to abiotic oxidations resulting in bromination of SOM. Through lab-based degradation treatments of plant material and soil humus, we have shown that abiotic bromination of particulate organic matter occurs in the presence of a range of inorganic oxidants, including hydrogen peroxide and assorted forms of ferric iron, producing both aliphatic and aromatic forms of organobromine. Bromination of oak and pine litter is limited primarily by bromide concentration. Fresh plant material is more susceptible to bromination than decayed litter and soil humus, due to a labile pool of mainly aliphatic compounds that break down during early stages of SOM formation. As the first evidence of abiotic bromination of particulate SOM, this study identifies a mechanistic source of the natural organobromine in humic substances and the soil organic horizon. Formation of organobromine through oxidative treatments of plant material also provides insights into the relative stability of aromatic and aliphatic components of SOM.

  19. Biodegradation of volatile organic compounds by five fungal species

    Energy Technology Data Exchange (ETDEWEB)

    Qi, B.; Moe, W.M. [Dept. of Civil and Environmental Engineering, Louisiana State Univ., Baton Rouge, LA (United States); Kinney, K.A. [Dept. of Civil Engineering, Univ. of Texas, Austin (United States)

    2002-07-01

    Five fungal species, Cladosporium resinae (ATCC 34066), Cladosporium sphaerospermum (ATCC 200384), Exophiala lecanii-corni (CBS 102400), Mucor rouxii (ATCC 44260), and Phanerochaete chrysosporium (ATCC 24725), were tested for their ability to degrade nine compounds commonly found in industrial off-gas emissions. Fungal cultures inoculated on ceramic support media were provided with volatile organic compounds (VOCs) via the vapor phase as their sole carbon and energy sources. Compounds tested included aromatic hydrocarbons (benzene, ethylbenzene, toluene, and styrene), ketones (methyl ethyl ketone, methyl isobutyl ketone, and methyl propyl ketone), and organic acids (n-butyl acetate, ethyl 3-ethoxypropionate). Experiments were conducted using three pH values ranging from 3.5 to 6.5. Fungal ability to degrade each VOC was determined by observing the presence or absence of visible growth on the ceramic support medium during a 30-day test period. Results indicate that E. lecanii-corni and C. sphaerospermum can readily utilize each of the nine VOCs as a sole carbon and energy source. P. chrysosporium was able to degrade all VOCs tested except for styrene under the conditions imposed. C. resinae was able to degrade both organic acids, all of the ketones, and some of the aromatic compounds (ethylbenzene and toluene); however, it was not able to grow utilizing benzene or styrene under the conditions tested. With the VOCs tested, M. rouxii produced visible growth only when supplied with n-butyl acetate or ethyl 3-ethoxypropionate. Maximum growth for most fungi was observed at a pH of approximately 5.0. The experimental protocol utilized in these studies is a useful tool for assessing the ability of different fungal species to degrade gas-phase VOCs under conditions expected in a biofilter application. (orig.)

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

    Science.gov (United States)

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

    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.

  1. Biofiltration for control of volatile organic compounds (VOCS)

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, D.F. [Environmental Protection Agency, Cincinnati, OH (United States); Govind, R. [Univ. of Cincinnati, OH (United States)

    1995-10-01

    Air biofiltration is a promising technology for control of air emissions of biodegradable volatile organic compounds (VOCs). In conjunction with vacuum extraction of soils or air stripping of ground water, it can be used to mineralize VOCs removed from contaminated soil or groundwater. The literature describes three major biological systems for treating contaminated air bioscrubbers, biotrickling filters and biofilters. Filter media can be classified as: bioactive fine or irregular particulates, such as soil, peat, compost or mixtures of these materials; pelletized, which are randomly packed in a bed; and structured, such as monoliths with defined or variable passage size and geometry. The media can be made of sorbing and non-absorbing materials. Non-bioactive pelletized and structured media require recycled solutions of nutrients and buffer for efficient microbial activity and are thus called biotrickling filters. Extensive work has been conducted to improve biofiltration by EPA`s Risk Reduction Engineering Laboratory and the University of Cincinnati in biofilters using pelletized and structured media and improved operational approaches. Representative VOCs in these studies included compounds with a range of aqueous solubilities and octanol-water partition coefficients. The compounds include iso-pentane, toluene, methylene chloride, trichloroethylene (TCE), ethyl benzene, chlorobenzene and perchloroethylene (PCE) and alpha ({alpha}-) pinene. Comparative studies were conducted with peat/compost biofilters using isopentane and {alpha}-pinene. Control studies were also conducted to investigate adsorption/desorption of contaminants on various media using mercuric chloride solution to insure the absence of bioactivity.

  2. Methods in plant foliar volatile organic compounds research.

    Science.gov (United States)

    Materić, Dušan; Bruhn, Dan; Turner, Claire; Morgan, Geraint; Mason, Nigel; Gauci, Vincent

    2015-12-01

    Plants are a major atmospheric source of volatile organic compounds (VOCs). These secondary metabolic products protect plants from high-temperature stress, mediate in plant-plant and plant-insect communication, and affect our climate globally. The main challenges in plant foliar VOC research are accurate sampling, the inherent reactivity of some VOC compounds that makes them hard to detect directly, and their low concentrations. Plant VOC research relies on analytical techniques for trace gas analysis, usually based on gas chromatography and soft chemical ionization mass spectrometry. Until now, these techniques (especially the latter one) have been developed and used primarily by physicists and analytical scientists, who have used them in a wide range of scientific research areas (e.g., aroma, disease biomarkers, hazardous compound detection, atmospheric chemistry). The interdisciplinary nature of plant foliar VOC research has recently attracted the attention of biologists, bringing them into the field of applied environmental analytical sciences. In this paper, we review the sampling methods and available analytical techniques used in plant foliar VOC research to provide a comprehensive resource that will allow biologists moving into the field to choose the most appropriate approach for their studies.

  3. Characterization of volatile organic compounds from different cooking emissions

    Science.gov (United States)

    Cheng, Shuiyuan; Wang, Gang; Lang, Jianlei; Wen, Wei; Wang, Xiaoqi; Yao, Sen

    2016-11-01

    Cooking fume is regarded as one of the main sources of urban atmospheric volatile organic compounds (VOCs) and its chemical characteristics would be different among various cooking styles. In this study, VOCs emitted from four different Chinese cooking styles were collected. VOCs concentrations and emission characteristics were analyzed. The results demonstrated that Barbecue gave the highest VOCs concentrations (3494 ± 1042 μg/m3), followed by Hunan cuisine (494.3 ± 288.8 μg/m3), Home cooking (487.2 ± 139.5 μg/m3), and Shandong cuisine (257.5 ± 98.0 μg/m3). The volume of air drawn through the collection hood over the stove would have a large impact on VOCs concentration in the exhaust. Therefore, VOCs emission rates (ER) and emission factors (EF) were also estimated. Home cooking had the highest ER levels (12.2 kg/a) and Barbecue had the highest EF levels (0.041 g/kg). The abundance of alkanes was higher in Home cooking, Shandong cuisine and Hunan cuisine with the value of 59.4%-63.8%, while Barbecue was mainly composed of alkanes (34.7%) and alkenes (39.9%). The sensitivity species of Home cooking and Hunan cuisine were alkanes, and that of Shandong cuisine and Barbecue were alkenes. The degree of stench pollution from cooking fume was lighter.

  4. [Ion mobility spectrometry for the isomeric volatile organic compounds].

    Science.gov (United States)

    Han, Hai-yan; Jia, Xian-de; Huang, Guo-dong; Wang, Hong-mei; Li, Jian-quan; Jin, Shun-ping; Jiang, Hai-he; Chu, Yan-nan; Zhou, Shi-kang

    2007-10-01

    Ion mobility spectrometry (IMS) is based on determining the drift velocities, which the ionized sample molecules attain in the weak electric field of a drift tube at atmospheric pressure. The drift behavior can be affected by structural differences of the analytes, so that ion mobility spectrometry has the ability to separated isomeric compounds. In the present article, an introduction to IMS is given, followed by a description of the instrument used for the experiments to differentiate isomeric compounds. Positive ion mobility spectras of three kinds of isomeric volatile organic compounds were studied in a homemade high-resolution IMS apparatus with a discharge ionization source. The study includes the differences in the structure of carbon chain, the style of function group, and the position of function group. The reduced mobility values were determined, which are in very good agreement with the previously reported theoretical values using neural network theory. The influence of the structural features of the substances and including the size and shape of the molecule has been investigated. The reduced mobility values increases in the order: alcohols ion mobility spectra of the constitutional isomers studied reflect the influence of structural features. In order to calibrate or determine the detection limits and the sensitivity of the ion mobility spectrometry, the exponential dilution flask (EDF) was used. Using this method, the detection limit of the analytes can reach the order of magnitude of ng x L(-1).

  5. Volatile organic silicon compounds: the most undesirable contaminants in biogases.

    Science.gov (United States)

    Ohannessian, Aurélie; Desjardin, Valérie; Chatain, Vincent; Germain, Patrick

    2008-01-01

    Recently a lot of attention has been focused on volatile organic silicon compounds (VOSiC) present in biogases. They induce costly problems due to silicate formation during biogas combustion in valorisation engine. The cost of converting landfill gas and digester gas into electricity is adversely affected by this undesirable presence. VOSiC in biogases spark off formation of silicate deposits in combustion chambers. They engender abrasion of the inner surfaces leading to serious damage, which causes frequent service interruptions, thus reducing the economic benefit of biogases. It is already known that these VOSiC originate from polydimethylsiloxanes (PDMS) hydrolysis. PDMS (silicones) are used in a wide range of consumer and industrial applications. PDMS are released into the environment through landfills and wastewater treatment plants. There is a lack of knowledge concerning PDMS biodegradation during waste storage. Consequently, understanding PDMS behaviour in landfill cells and in sludge digester is particularly important. In this article, we focused on microbial degradation of PDMS through laboratory experiments. Preliminary test concerning anaerobic biodegradation of various PDMS have been investigated. Results demonstrate that the biotic step has an obvious influence on PDMS biodegradation. IWA Publishing 2008.

  6. Volatile organic emissions from the distillation and pyrolysis of vegetation

    Directory of Open Access Journals (Sweden)

    J. P. Greenberg

    2006-01-01

    Full Text Available Leaf and woody plant tissue (Pinus ponderosa, Eucalyptus saligna, Quercus gambelli, Saccharum officinarum and Oriza sativa were heated from 30 to 300°C and volatile organic compound (VOC emissions were identified and quantified. Major VOC emissions were mostly oxygenated and included acetic acid, furylaldehyde, acetol, pyrazine, terpenes, 2,3-butadione, phenol and methanol, as well as smaller emissions of furan, acetone, acetaldehyde, acetonitrile and benzaldehyde. Total VOC emissions from distillation and pyrolysis were on the order of 10 gC/kgC dry weight of vegetation, as much as 33% and 44% of CO2 emissions (gC(VOC/gC(CO2 measured during the same experiments, in air and nitrogen atmospheres, respectively. The emissions are similar in identity and quantity to those from smoldering combustion of woody tissue and of different character than those evolved during flaming combustion. VOC emissions from the distillation of pools and endothermic pyrolysis under low turbulence conditions may produce flammable concentrations near leaves and may facilitate the propagation of wildfires. VOC emissions from charcoal production are also related to distillation and pyrolysis; the emissions of the highly reactive VOCs from production are as large as the carbon monoxide emissions.

  7. [Determination of volatile organic compounds in atmospheric environment].

    Science.gov (United States)

    Chen, H W; Li, G K; Li, H; Zhang, Z X; Wang, B G; Li, T; Luo, H K

    2001-11-01

    It is well known that volatile organic compounds (VOCs) are the main photochemical pollutants and ozone precursors of the photochemical smog. Investigation of photochemical pollution in the ambient air must focus on VOCs, but the concentration of VOCs in ambient air is in a very low level (10(-9)-10(-12), volume fraction), so there are difficulties in the determination of VOCs. In this work, based on the TO14A and TO15 methods recommended by the Environmental Protection Agency of United States, an improved method for the determination of fifty-six VOCs, mainly O3 precursors, in atmospheric environment was developed. Operating conditions of VOCs preconcentrator, gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) were optimized. Air sample was first frozen by liquid nitrogen, and then H2O and CO2 were eliminated in the VOCs preconcentrator. The preconcentrated VOCs sample was injected to GC and detected by MS or hydrogen flame ionization detector (FID). The C2-C10 hydrocarbons were separated effectively in capillary columns under the high concentration of CO2. The detection limits were 0.1 microgram.m-3 and the relative standard deviations were in the range from 2.57% to 9.82%. This method has been used for the determination of VOCs in real samples. The results were satisfactory.

  8. Diurnal characteristics of volatile organic compounds in the Seoul atmosphere

    Science.gov (United States)

    Na, Kwangsam; Kim, Yong Pyo; Moon, Kil Choo

    Concentrations of volatile organic compounds (VOCs) were measured at a site in central Seoul from 8 to 13 September 1998. On each sampling day, three 2-h-integrated canister samples were collected in the morning, afternoon and evening, respectively, to observe diural variations of VOCs. Most of the VOCs species showed diurnal variations with higher concentrations during the morning and evening, and lower concentrations during the afternoon. However, in the afternoon, the concentrations of aromatic compounds, closely correlated with solvent usage such as toluene, ethylbenzene, m-/p-xylene, and o-xylene, were slightly higher than or comparable to those in the morning. This may be due to the increase of evaporative emissions derived from the rise in ambient temperature and additional sources such as the use of solvents in painting, printing and dry cleaning. To estimate the participation of individual VOCs in ozone formation, propylene equivalent concentrations were calculated. The results showed that toluene was the most dominant contributor to ozone formation as well as ambient VOC concentrations. Toluene/benzene and m-/ p-xylene/benzene ratios showed a high observed in the afternoon and a low observed in the morning and evening. This may be because the contribution of evaporative emissions by solvent usage on the ambient VOC concentrations is more dominant than those of vehicle-related emissions and photochemical loss.

  9. Emission characteristics of volatile organic compounds from semiconductor manufacturing.

    Science.gov (United States)

    Chein, HungMin; Chen, Tzu Ming

    2003-08-01

    A huge amount of volatile organic compounds (VOCs) is produced and emitted with waste gases from semiconductor manufacturing processes, such as cleaning, etching, and developing. VOC emissions from semiconductor factories located at Science-Based Industrial Park, Hsin-chu, Taiwan, were measured and characterized in this study. A total of nine typical semiconductor fabricators (fabs) were monitored over a 12-month period (October 2000-September 2001). A flame ionization analyzer was employed to measure the VOC emission rate continuously in a real-time fashion. The amount of chemical use was adopted from the data that were reported to the Environmental Protection Bureau in Hsin-chu County as per the regulation of the Taiwan Environmental Protection Administration. The VOC emission factor, defined as the emission rate (kg/month) divided by the amount of chemical use (L/month), was determined to be 0.038 +/- 0.016 kg/L. A linear regression equation is proposed to fit the data with the correlation coefficient (R2)=0.863. The emission profiles of VOCs, which were drawn using the gas chromatograph/mass spectrometer analysis method, show that isopropyl alcohol is the dominant compound in most of the fabs.

  10. Constituents of volatile organic compounds of evaporating essential oil

    Science.gov (United States)

    Chiu, Hua-Hsien; Chiang, Hsiu-Mei; Lo, Cho-Ching; Chen, Ching-Yen; Chiang, Hung-Lung

    2009-12-01

    Essential oils containing aromatic compounds can affect air quality when used indoors. Five typical and popular essential oils—rose, lemon, rosemary, tea tree and lavender—were investigated in terms of composition, thermal characteristics, volatile organic compound (VOC) constituents, and emission factors. The activation energy was 6.3-8.6 kcal mol -1, the reaction order was in the range of 0.6-0.8, and the frequency factor was 0.01-0.24 min -1. Toluene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, n-undecane, p-diethylbenzene and m-diethylbenzene were the predominant VOCs of evaporating gas of essential oils at 40 °C. In addition, n-undecane, p-diethylbenzene, 1,2,4-trimethylbenzene, m-diethylbenzene, and 1,2,3-trimethylbenzene revealed high emission factors during the thermogravimetric (TG) analysis procedures. The sequence of the emission factors of 52 VOCs (137-173 mg g -1) was rose ≈ rosemary > tea tree ≈ lemon ≈ lavender. The VOC group fraction of the emission factor of aromatics was 62-78%, paraffins were 21-37% and olefins were less than 1.5% during the TG process. Some unhealthy VOCs such as benzene and toluene were measured at low temperature; they reveal the potential effect on indoor air quality and human health.

  11. A biogenic volatile organic compounds emission inventory for Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi-hui; BAI Yu-hua; ZHANG Shu-yu

    2005-01-01

    The first detailed inventory for volatile organic compounds(VOC) emissions from vegetation over Yunnan Province, China was presented. The spatially and temporally resolved inventory was developed based on a geographic information system (GIS), remote sensing(RS) data and field measurement data, such as digitized land-use data, normalized difference vegetation index (NDVl) and temperature data from direct real-time measurement. The inventory has a spatial resolution of 5 km × 5 km and a time resolution of 1 h.Urban, agriculture, and natural land-use distributions in Yunnan Province were combined with biomass factors for each land-use category to produce a spatially resolved biomass inventory. A biogenic emission inventory was developed by combining the biomass inventory with hourly emission rates for tree, shrub and ground cover species of the study area. Correcting for environmental factors, including light intensity and temperature, a value of 1.1 × 1012 gC for total annual biogenic VOC emissions from Yunnan Province, including 6.1 × 1011 gCfor isoprene, 2.1 × 1011 gC for monoterpenes, and 2.6 × 1011 gC for OVOC was obtained. The highest VOC emissions occurred in the northwestern, southwestern and north region of Yunnan Province. Some uncertainties were also discussed in this study.

  12. Analysis of volatile organic compounds released during food decaying processes.

    Science.gov (United States)

    Phan, Nhu-Thuc; Kim, Ki-Hyun; Jeon, Eui-Chan; Kim, Uk-Hun; Sohn, Jong Ryeul; Pandey, Sudhir Kumar

    2012-03-01

    A number of volatile organic compounds (VOCs) including acetone, methyl ethyl ketone, toluene, ethylbenzene, m,p-xylene, styrene, and o- xylene released during food decaying processes were measured from three types of decaying food samples (Kimchi (KC), fresh fish (FF), and salted fish (SF)). To begin with, all the food samples were contained in a 100-mL throwaway syringe. These samples were then analyzed sequentially for up to a 14-day period. The patterns of VOC release contrasted sharply between two types of fish (FF and SF) and KC samples. A comparison of data in terms of total VOC showed that the mean values for the two fish types were in the similar magnitude with 280 ± 579 (FF) and 504 ± 1,089 ppmC (SF), while that for KC was much lower with 16.4 ± 7.6 ppmC. There were strong variations in VOC emission patterns during the food decaying processes between fishes and KC that are characterized most sensitively by such component as styrene. The overall results of this study indicate that concentration levels of the VOCs differed significantly between the food types and with the extent of decaying levels through time.

  13. Volatile organic compounds in fourteen U.S. retail stores.

    Science.gov (United States)

    Nirlo, E L; Crain, N; Corsi, R L; Siegel, J A

    2014-10-01

    Retail buildings have a potential for both short-term (customer) and long-term (occupational) exposure to indoor pollutants. However, little is known about volatile organic compound (VOC) concentrations in the retail sector and influencing factors, such as ventilation, in-store activities, and store type. We measured VOC concentrations and ventilation rates in 14 retail stores in Texas and Pennsylvania. With the exception of formaldehyde and acetaldehyde, VOCs were present in retail stores at concentrations well below health guidelines. Indoor formaldehyde concentrations ranged from 4.6 ppb to 67 ppb. The two mid-sized grocery stores in the sample had the highest levels of ethanol and acetaldehyde, with concentrations up to 2.6 ppm and 92 ppb, respectively, possibly due to the preparation of dough and baking activities. Indoor-to-outdoor concentration ratios indicated that indoor sources were the main contributors to indoor VOC concentrations for the majority of compounds. There was no strong correlation between ventilation and VOC concentrations across all stores. However, increasing the air exchange rates at two stores led to lower indoor VOC concentrations, suggesting that ventilation can be used to reduce concentrations for some specific stores.

  14. Volatile organic compounds emissions from gasoline and diesel powered vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Mugica, V [Universidad Autonoma Metropolitana, Mexico, D.F. (Mexico); Vega, E; Sanchez, G; Reyes, E; Arriaga, J. L [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Chow, J; Watson, J; Egami, R [Desert Research Institute, Reno, NV (United States)

    2001-01-01

    In this research, volatile organic compound emissions were characterized from gasoline and diesel vehicles. Sampling campaigns in the Metropolitan Area of Mexico City were designed and carried out in tunnels, crossroads, and truck and bus terminals. The samples were analyzed with gas chromatography getting more than 250 different compounds, being more or less 60 of them the 80% of all the emissions. The most abundant are the two carbon compounds, as a result of the combustion, and compounds related to fuels compositions, like isopentane, xylenes, toluene among others. The profiles obtained in tunnels and crossroads were very similar with the exception of the 3 and 4 carbon compounds, which were found in bigger proportion in the profiles at crossroads. This may probably be due to the blend with the ambient air. The profiles corresponding to trucks and buses have a smaller content of two carbon compounds and a bigger content of xylenes, toluene and ethylbenzene. The variations in the proportions of the compounds allow differentiating the profiles of vehicles using gasoline and diesel. [Spanish] En este trabajo se caracterizaron las emisiones de compuestos organicos volatiles provenientes de vehiculos a gasolina y a diesel. Para ello, se disenaron diversas campanas de muestreo en la zona Metropolitana de la Ciudad de Mexico, en tuneles, cruceros y estaciones de camiones de carga y autobuses. Las muestras se analizaron con cromatografia, de gases obteniendose mas de 250 compuestos distintos, de los cuales aproximadamente 60 corresponden a mas del 80% de las emisiones. Los compuestos mas abundantes son los de dos carbonos, resultado de la combustion, y 4 carbonos que se encontraron en mayor proporcion en los perfiles de cruceros, lo cual se debe probablemente a la mezcla con el aire ambiente. Los perfiles correspondientes a camiones de carga y autobuses tienen un menor contenido de compuestos de dos carbonos y un mayor contenido de xilenos, tolueno y etilbenceno. Estas

  15. Assessing Emissions of Volatile Organic Componds from Landfills Gas

    Directory of Open Access Journals (Sweden)

    Fahime Khademi

    2016-01-01

    Full Text Available Background: Biogas is obtained by anaerobic decomposition of organic wastes buried materials used to produce electricity, heat and biofuels. Biogas is at the second place for power generation after hydropower and in 2000 about 6% of the world power generation was allocated to biogas. Biogas is composed of 40–45 vol% CO2, 55–65 vol% CH4, and about 1% non-methaneVOCs, and non-methane volatile organic compounds. Emission rates are used to evaluate the compliance with landfill gas emission regulations by the United States Environmental Protection Agency (USEPA. BTEX comounds affect the air quality and may be harmful to human health. Benzene, toluene, ethylbenzene and xylene isomers that are generally called BTEX compounds are the most abundant VOCs in biogas. Methods: Sampling of VOCs in biogas vents was operated passively or with Tedlar bags. 20 samples were collected from 40 wells of old and new biogas sites of Shiraz’ landfill. Immediately after sampling, the samples were transferred to the laboratory. Analysis of the samples was performed with GC-MS. Results: The results showed that in the collection of the old and new biogas sites, the highest concentration of VOCs was observed in toluene (0.85ppm followed by benzene (0.81ppm, ethylbenzene (0.13ppm and xylene (0.08ppm. Conclusion: The results of the study showed that in all samples, most available compounds in biogas vents were aromatic hydrocarbon compounds.These compounds’ constituents originate from household hazardous waste materials deposited in the landfill or from biological/chemical decomposition processes within the landfill.

  16. Mapping Soil Organic Matter with Hyperspectral Imaging

    Science.gov (United States)

    Moni, Christophe; Burud, Ingunn; Flø, Andreas; Rasse, Daniel

    2014-05-01

    Soil organic matter (SOM) plays a central role for both food security and the global environment. Soil organic matter is the 'glue' that binds soil particles together, leading to positive effects on soil water and nutrient availability for plant growth and helping to counteract the effects of erosion, runoff, compaction and crusting. Hyperspectral measurements of samples of soil profiles have been conducted with the aim of mapping soil organic matter on a macroscopic scale (millimeters and centimeters). Two soil profiles have been selected from the same experimental site, one from a plot amended with biochar and another one from a control plot, with the specific objective to quantify and map the distribution of biochar in the amended profile. The soil profiles were of size (30 x 10 x 10) cm3 and were scanned with two pushbroomtype hyperspectral cameras, one which is sensitive in the visible wavelength region (400 - 1000 nm) and one in the near infrared region (1000 - 2500 nm). The images from the two detectors were merged together into one full dataset covering the whole wavelength region. Layers of 15 mm were removed from the 10 cm high sample such that a total of 7 hyperspectral images were obtained from the samples. Each layer was analyzed with multivariate statistical techniques in order to map the different components in the soil profile. Moreover, a 3-dimensional visalization of the components through the depth of the sample was also obtained by combining the hyperspectral images from all the layers. Mid-infrared spectroscopy of selected samples of the measured soil profiles was conducted in order to correlate the chemical constituents with the hyperspectral results. The results show that hyperspectral imaging is a fast, non-destructive technique, well suited to characterize soil profiles on a macroscopic scale and hence to map elements and different organic matter quality present in a complete pedon. As such, we were able to map and quantify biochar in our

  17. Microcantilever sensors coated with a sensitive polyaniline layer for detecting volatile organic compounds.

    Science.gov (United States)

    Steffens, C; Leite, F L; Manzoli, A; Sandovall, R D; Fatibello, O; Herrmann, P S P

    2014-09-01

    This paper describes a silicon cantilever sensor coated with a conducting polymer layer. The mechanical response (deflection) of the bimaterial (the coated microcantilever) was investigated under the influence of several volatile compounds-methanol, ethanol, acetone, propanol, dichloroethane, toluene and benzene. The variations in the deflection of the coated and uncoated microcantilevers when exposed to volatile organic compounds were evaluated, and the results indicated that the highest sensitivity was obtained with the coated microcantilever and methanol. The uncoated microcantilever was not sensitive to the volatile organic compounds. An increase in the concentration of the volatile organic compound resulted in higher deflections of the microcantilever sensor. The sensor responses were reversible, sensible, rapid and proportional to the volatile concentration.

  18. Volatility of organic aerosol and its components in the megacity of Paris

    Science.gov (United States)

    Paciga, Andrea; Karnezi, Eleni; Kostenidou, Evangelia; Hildebrandt, Lea; Psichoudaki, Magda; Engelhart, Gabriella J.; Lee, Byong-Hyoek; Crippa, Monica; Prévôt, André S. H.; Baltensperger, Urs; Pandis, Spyros N.

    2016-02-01

    Using a mass transfer model and the volatility basis set, we estimate the volatility distribution for the organic aerosol (OA) components during summer and winter in Paris, France as part of the collaborative project MEGAPOLI. The concentrations of the OA components as a function of temperature were measured combining data from a thermodenuder and an aerosol mass spectrometer (AMS) with Positive Matrix Factorization (PMF) analysis. The hydrocarbon-like organic aerosol (HOA) had similar volatility distributions for the summer and winter campaigns with half of the material in the saturation concentration bin of 10 µg m-3 and another 35-40 % consisting of low and extremely low volatility organic compounds (LVOCs with effective saturation concentrations C* of 10-3-0.1 µg m-3 and ELVOCs C* less or equal than 10-4 µg m-3, respectively). The winter cooking OA (COA) was more than an order of magnitude less volatile than the summer COA. The low-volatility oxygenated OA (LV-OOA) factor detected in the summer had the lowest volatility of all the derived factors and consisted almost exclusively of ELVOCs. The volatility for the semi-volatile oxygenated OA (SV-OOA) was significantly higher than that of the LV-OOA, containing both semi-volatile organic components (SVOCs with C* in the 1-100 µg m-3 range) and LVOCs. The oxygenated OA (OOA) factor in winter consisted of SVOCs (45 %), LVOCs (25 %) and ELVOCs (30 %). The volatility of marine OA (MOA) was higher than that of the other factors containing around 60 % SVOCs. The biomass burning OA (BBOA) factor contained components with a wide range of volatilities with significant contributions from both SVOCs (50 %) and LVOCs (30 %). Finally, combining the bulk average O : C ratios and volatility distributions of the various factors, our results are placed into the two-dimensional volatility basis set (2D-VBS) framework. The OA factors cover a broad spectrum of volatilities with no direct link between the average volatility and

  19. Bioactivity of volatile organic compounds produced by Pseudomonas tolaasii

    Directory of Open Access Journals (Sweden)

    Pietro eLo Cantore

    2015-10-01

    Full Text Available Pseudomonas tolaasii is the main bacterial pathogen of several mushroom species. In this paper we report that strains of P. tolaasii produce volatile substances inducing in vitro mycelia growth inhibition of Pleurotus ostreatus and P. eryngii, and Agaricus bisporus and P. ostreatus basidiome tissue blocks brown discoloration. P. tolaasii strains produced the volatile ammonia but not hydrogen cyanide. Among the volatiles detected by GC-MS, methanethiol, dimethyl disulfide, and 1-undecene were identified. The latter, when assayed individually as pure compounds, led to similar effects noticed when P. tolaasii volatiles natural blend was used on mushrooms mycelia and basidiome tissue blocks. Furthermore, the natural volatile mixture, resulted toxic toward lettuce and broccoli seedling growth. In contrast, pure volatiles showed different activity according to their nature and/or doses applied. Indeed, methanethiol resulted toxic at all the doses used, while dimethyl disulfide toxicity was assessed till a quantity of 1.25 µg, below which it caused, together with 1-undecene ( 10 µg, broccoli growth increase.

  20. An original data treatment for infrared spectra of organic matter, application to extracted soil organic matter

    Science.gov (United States)

    Gomes Rossin, Bruna; Redon, Roland; Raynaud, Michel; Nascimento, Nadia Regina; Mounier, Stéphane

    2017-04-01

    Infrared spectra of extracted organic matter are easy and rapid to do, but generally hard to interpreted over the presence or not of certain organic functions. Indeed, the organic matter is a complex mixture of molecules often having absorption overlapping and it is also difficult to have a well calibrated or normalised spectra due to the difficulty to have a well known solid content or homogeneity for a sample (Monakhova et al. 2015, Tadini et al. 2015, Bardy et al. 2008). In this work, the IRTF (InfraRed Fourier Transform) spectra were treated by an original algorithm developed to obtain the principal components of the IRTF spectra and their contributions for each sample. This bilinear decomposition used a PCA initialisation and the principal components were estimated from vectors calculated by PCA and linearly combined to provide non-negative signals minimizing a criterion based on cross-correlation. Hence, using this decomposition, it is possible to define IRTF signal of organic matter fractions like humic acid or fulvic acid depending on their origin like surface of depth of soil profiles. The method was used on a set of sample from Upper Negro River Basin (Amazon, Brazil) (Bueno,2009), where three soils sequences from surface to two meter depth containing 10 slices each. The sequences were sampled on a podzol well drain, a hydromorphic podzol and a cryptopodzol. From the IRTF data five representative component spectra were defined for all the extracted organic matter , and using other chemical composition information, a mechanism of organic matter fate is proposed to explain the observed results. Bardy, M., E. Fritsch, S. Derenne, T. Allard, N. R. do Nascimento, and G. T. Bueno. 2008. "Micromorphology and Spectroscopic Characteristics of Organic Matter in Waterlogged Podzols of the Upper Amazon Basin." Geoderma 145 (3-4): 222-30. Bueno, G.T. Appauvrissement et podzolisation des latérites du baissin du Rio Negro et gênese dês Podzols dans le haut bassin

  1. Stability of Ferrihydrite and Organic Matter in Ferrihydrite-Organic Matter Associations

    Science.gov (United States)

    Eusterhues, K.; Totsche, K. U.

    2015-12-01

    Iron oxides can bind particularly large amounts of organic matter (OM) and seem to be an important control on OM storage in many soils. To better understand the interactions between Fe oxides and OM, we produced ferrihydrite-OM associations by adsorption and coprecipitation in laboratory experiments. Because ferrihydrites are often formed in OM-rich solutions, we assume that coprecipitation is a common process in nature. In contrast to adsorption on pre-existing ferrihydrite surfaces, coprecipitation involves adsorption, occlusion (physical entrapment of OM), formation of Fe-OM complexes, and poisoning of ferrihydrite growth. The reactivity of coprecipitates may therefore differ from ferriydrites with adsorbed OM. Incubation experiments with an inoculum extracted from a Podzol forest-floor were carried out to quantify the mineralization of the adsorbed and coprecipitated organic matter. These experiments showed that the association with ferrihydrite stabilized the associated organic matter, but that differences in the degradability of adsorbed and coprecipitated organic matter were small. We therefore conclude that coprecipitation does not lead to a significant formation of microbial inaccessible organic matter domains. Microbial reduction experiments were performed using Geobacter bremensis. We observed that increasing amounts of associated OM led to decreasing initial reaction rates and a decreasing degree of dissolution. Reduction of coprecipitated ferrihydrites was faster than reduction of ferrihydrites with adsorbed OM. Our data demonstrate that the association with ferrihydrite can effectively stabilize labile polysaccharides. Vice versa, these polysaccharides may protect ferrihydrite from reduction by Geobacter-like bacteria. However, a challenge for future studies will be to link formation and degradation of mineral-organic associations to natural porous systems, that is, to the complex interplay of mass transport and microbial distribution in the

  2. Transport of volatile organic compounds across the capillary fringe

    Science.gov (United States)

    McCarthy, Kathleen A.; Johnson, Richard L.

    1993-01-01

    Physical experiments were conducted to investigate the transport of a dissolved volatile organic compound (trichloroethylene, TCE) from shallow groundwater to the unsaturated zone under a variety of conditions including changes in the soil moisture profile and water table position. Experimental data indicated that at moderate groundwater velocities (0.1 m/d), vertical mechanical dispersion was negligible and molecular diffusion was the dominant vertical transport mechanism. Under these conditions, TCE concentrations decreased nearly 3 orders of magnitude across the capillary fringe and soil gas concentrations remained low relative to those of underlying groundwater. Data collected during a water table drop showed a short-term increase in concentrations throughout most of the unsaturated zone, but these concentrations quickly declined and approached initial values after the water table was returned to its original level. In the deep part of the unsaturated zone, the water table drop resulted in a long-term decrease in concentrations, illustrating the effects of hysteresis in the soil moisture profile. A two-dimensional random walk advection-diffusion model was developed to simulate the experimental conditions, and numerical simulations agreed well with experimental data. A simpler, one-dimensional finite-difference diffusion-dispersion model was also developed. One-dimensional simulations based on molecular diffusion also agreed well with experimental data. Simulations which incorporated mechanical dispersion tended to overestimate flux across the capillary fringe. Good agreement between the one- and two-dimensional models suggested that a simple, one-dimensional approximation of vertical transport across the capillary fringe can be useful when conditions are appropriate.

  3. Urinary Volatile Organic Compounds for the Detection of Prostate Cancer.

    Directory of Open Access Journals (Sweden)

    Tanzeela Khalid

    Full Text Available The aim of this work was to investigate volatile organic compounds (VOCs emanating from urine samples to determine whether they can be used to classify samples into those from prostate cancer and non-cancer groups. Participants were men referred for a trans-rectal ultrasound-guided prostate biopsy because of an elevated prostate specific antigen (PSA level or abnormal findings on digital rectal examination. Urine samples were collected from patients with prostate cancer (n = 59 and cancer-free controls (n = 43, on the day of their biopsy, prior to their procedure. VOCs from the headspace of basified urine samples were extracted using solid-phase micro-extraction and analysed by gas chromatography/mass spectrometry. Classifiers were developed using Random Forest (RF and Linear Discriminant Analysis (LDA classification techniques. PSA alone had an accuracy of 62-64% in these samples. A model based on 4 VOCs, 2,6-dimethyl-7-octen-2-ol, pentanal, 3-octanone, and 2-octanone, was marginally more accurate 63-65%. When combined, PSA level and these four VOCs had mean accuracies of 74% and 65%, using RF and LDA, respectively. With repeated double cross-validation, the mean accuracies fell to 71% and 65%, using RF and LDA, respectively. Results from VOC profiling of urine headspace are encouraging and suggest that there are other metabolomic avenues worth exploring which could help improve the stratification of men at risk of prostate cancer. This study also adds to our knowledge on the profile of compounds found in basified urine, from controls and cancer patients, which is useful information for future studies comparing the urine from patients with other disease states.

  4. Diagnosing Tibetan pollutant sources via volatile organic compound observations

    Science.gov (United States)

    Li, Hongyan; He, Qiusheng; Song, Qi; Chen, Laiguo; Song, Yongjia; Wang, Yuhang; Lin, Kui; Xu, Zhencheng; Shao, Min

    2017-10-01

    Atmospheric transport of black carbon (BC) from surrounding areas has been shown to impact the Tibetan environment, and clarifying the geographical source and receptor regions is crucial for providing guidance for mitigation actions. In this study, 10 trace volatile organic compounds (VOCs) sampled across Tibet are chosen as proxies to diagnose source regions and related transport of pollutants to Tibet. The levels of these VOCs in Tibet are higher than those in the Arctic and Antarctic regions but much lower than those observed at many remote and background sites in Asia. The highest VOC level is observed in the eastern region, followed by the southern region and the northern region. A positive matrix factorization (PMF) model found that three factors-industry, biomass burning, and traffic-present different spatial distributions, which indicates that different zones of Tibet are influenced by different VOC sources. The average age of the air masses in the northern and eastern regions is estimated to be 3.5 and 2.8 days using the ratio of toluene to benzene, respectively, which indicates the foreign transport of VOC species to those regions. Back-trajectory analyses show that the Afghanistan-Pakistan-Tajikistan region, Indo-Gangetic Plain (IGP), and Meghalaya-Myanmar region could transport industrial VOCs to different zones of Tibet from west to east. The agricultural bases in northern India could transport biomass burning-related VOCs to the middle-northern and eastern zones of Tibet. High traffic along the unique national roads in Tibet is associated with emissions from local sources and neighboring areas. Our study proposes international joint-control efforts and targeted actions to mitigate the climatic changes and effects associated with VOCs in Tibet, which is a climate sensitive region and an important source of global water.

  5. Assessment of volatile organic compound emissions from ecosystems of China

    Science.gov (United States)

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

    2002-11-01

    Isoprene, monoterpene, and other volatile organic compound (VOC) emissions from grasslands, shrublands, forests, and peatlands in China were characterized to estimate their regional magnitudes and to compare these emissions with those from landscapes of North America, Europe, and Africa. Ecological and VOC emission sampling was conducted at 52 sites centered in and around major research stations located in seven different regions of China: Inner Mongolia (temperate), Changbai Mountain (boreal-temperate), Beijing Mountain (temperate), Dinghu Mountain (subtropical), Ailao Mountain (subtropical), Kunming (subtropical), and Xishuangbanna (tropical). Transects were used to sample plant species and growth form composition, leafy (green) biomass, and leaf area in forests representing nearly all the major forest types of China. Leafy biomass was determined using generic algorithms based on tree diameter, canopy structure, and absolute cover. Measurements of VOC emissions were made on 386 of the 541 recorded species using a portable photo-ionization detector method. For 105 species, VOC emissions were also measured using a flow-through leaf cuvette sampling/gas chromatography analysis method. Results indicate that isoprene and monoterpene emissions, as well as leafy biomass, vary systematically along gradients of ecological succession in the same manner found in previous studies in the United States, Canada, and Africa. Applying these results to a regional VOC emissions model, we arrive at a value of 21 Tg C for total annual biogenic VOC emissions from China, compared to 5 Tg C of VOCs released annually from anthropogenic sources there. The isoprene and monoterpene emissions are nearly the same as those reported for Europe, which is comparable in size to China.

  6. Stable carbon isotope ratios of ambient aromatic volatile organic compounds

    Science.gov (United States)

    Kornilova, Anna; Huang, Lin; Saccon, Marina; Rudolph, Jochen

    2016-09-01

    Measurements of mixing ratios and stable carbon isotope ratios of aromatic volatile organic compounds (VOC) in the atmosphere were made in Toronto (Canada) in 2009 and 2010. Consistent with the kinetic isotope effect for reactions of aromatic VOC with the OH radical the observed stable carbon isotope ratios are on average significantly heavier than the isotope ratios of their emissions. The change of carbon isotope ratio between emission and observation is used to determine the extent of photochemical processing (photochemical age, ∫ [OH]dt) of the different VOC. It is found that ∫ [OH]dt of different VOC depends strongly on the VOC reactivity. This demonstrates that for this set of observations the assumption of a uniform ∫ [OH]dt for VOC with different reactivity is not justified and that the observed values for ∫ [OH]dt are the result of mixing of VOC from air masses with different values for ∫ [OH]dt. Based on comparison between carbon isotope ratios and VOC concentration ratios it is also found that the varying influence of sources with different VOC emission ratios has a larger impact on VOC concentration ratios than photochemical processing. It is concluded that for this data set the use of VOC concentration ratios to determine ∫ [OH]dt would result in values for ∫ [OH]dt inconsistent with carbon isotope ratios and that the concept of a uniform ∫ [OH]dt for an air mass has to be replaced by the concept of individual values of an average ∫ [OH]dt for VOC with different reactivity.

  7. Determination of the solubility of low volatility liquid organic compounds in water using volatile-tracer assisted headspace gas chromatography.

    Science.gov (United States)

    Zhang, Shu-Xin; Chai, Xin-Sheng; Barnes, Donald G

    2016-02-26

    This study reports a new headspace gas chromatographic method (HS-GC) for the determination of water solubility of low volatility liquid organic compounds (LVLOs). The HS-GC analysis was performed on a set of aqueous solutions containing a range of concentrations of toluene-spiked (as a tracer) LVLOs, from under-saturation to over-saturation. A plot of the toluene tracer GC signal vs. the concentration of the LVLO results in two lines of different slopes that intersect at the concentration corresponding to the compound's solubility in water. The results showed that the HS-GC method has good precision (RSD solubility of LVLOs at elevated temperatures. This approach should be of special interest to those concerned about the impact of the presence of low-volatility organic liquids in waters of environmental and biological systems.

  8. Magmatic MORB Volatiles, Seafloor Hydrothermal Systems and Abiotic Organic Synthesis

    Science.gov (United States)

    Holloway, J. R.

    2007-12-01

    A plausible model for the origin of the observed C-O-H volatiles observed in MORB glasses is that they were incorporated in primary melts of the upwelling mantle. Based on the observed ferric/ferrous ratios in MORB glass, it is probable that the MORB source mantle contained diamond or graphite, depending on pressure. If true, then during partial mantle melting the graphite/diamond would react with FeO1.5 in garnet/spinel and clinopyroxene to form CO2 which would dissolve in the melt as carbonate ion. Using equation of state models for CO2 activity and ferric/ferrous ratios in the magma it is possible to model the amount of carbonate dissolved in the basaltic magma as a function of the degree of melting (Holloway and O'Day, 2000). The results require that rising MORB magma will become saturated in CO2 at depths much greater than those proposed for MORB magma chambers. Conversely H2O values observed in MORB glasses are far below saturation. However as CO2 reaches saturation and exsolves from the melt the low fO2 imposed by the low ferric/ferrous ratio results in a high H2/H2O ratio in the exsolving supercritical fluid. We have shown that fluids with this composition produce methanol (CH3OH) in the presence of magnetite at seafloor hydrothermal P-T conditions in a flow-through system (Voglesonger, et al., 2001) and that aqueous methanol solutions react in montmorillonite clay interlayers to form a wide variety of complex hydrocarbon molecules, the most abundant being hexamethyl benzene (Williams, et al., 2005). Methyl stearate (C17H35COOCH3) was also observed in moderate amounts. Holloway, J. R. and P. A. O'Day (2000). "Production of CO2 and H2 by Diking-Eruptive Events at Mid-Ocean Ridges: Implications for Abiotic Organic Synthesis and Global Geochemical Cycling." International Geology Review 42: 673-683. Voglesonger, K. M., J. R. Holloway, E. E. Dunn, P. J. Dalla-Betta and P. A. O'Day (2001). "Experimental Abiotic Synthesis of Methanol in Seafloor Hydrothermal

  9. Exchange of volatile organic compounds in the boreal forest floor

    Science.gov (United States)

    Aaltonen, Hermanni; Bäck, Jaana; Pumpanen, Jukka; Pihlatie, Mari; Hakola, Hannele; Hellén, Heidi; Aalto, Juho; Heinonsalo, Jussi; Kajos, Maija K.; Kolari, Pasi; Taipale, Risto; Vesala, Timo

    2013-04-01

    Terrestrial ecosystems, mainly plants, emit large amounts of volatile organic compounds (VOCs) into the atmosphere. In addition to plants, VOCs also have less-known sources, such as soil. VOCs are a very diverse group of reactive compounds, including terpenoids, alcohols, aldehydes and ketones. Due to their high reactivity, VOCs take part in formation and growth of secondary organic aerosols in the atmosphere and thus affect also Earth's radiation balance (Kulmala et al. 2004). We have studied boreal soil and forest floor VOC fluxes with chamber and snow gradient techniques we were developed. Spatial and temporal variability in VOC fluxes was studied with year-round measurements in the field and the sources of boreal soil VOCs in the laboratory with fungal isolates. Determination of the compounds was performed mass spectrometrically. Our results reveal that VOCs from soil are mainly emitted by living roots, above- and belowground litter and microbes. The strongest source appears to be litter, in which both plant residuals and decomposers play a role in the emissions. Soil fungi showed high emissions of lighter VOCs, like acetone, acetaldehyde and methanol, from isolates. Temperature and moisture are the most critical physical factors driving VOC fluxes. Since the environment in boreal forests undergoes strong seasonal changes, the VOC flux strength of the forest floor varies markedly during the year, being highest in spring and autumn. The high spatial heterogeneity of the forest floor was also clearly visible in VOC fluxes. The fluxes of other trace gases (CO2, CH4 and N2O) from soil, which are also related to the soil biological activity and physical conditions, did not show correlations with the VOC fluxes. These results indicate that emissions of VOCs from the boreal forest floor account for as much as several tens of percent, depending on the season, of the total forest ecosystem VOC emissions. This emphasises that forest floor compartment should be taken into

  10. Online measurements of the emissions of intermediate-volatility and semi-volatile organic compounds from aircraft

    Directory of Open Access Journals (Sweden)

    E. S. Cross

    2013-08-01

    Full Text Available A detailed understanding of the climate and air quality impacts of aviation requires measurements of the emissions of intermediate-volatility and semi-volatile organic compounds (I/SVOCs from aircraft. Currently both the amount and chemical composition of aircraft I/SVOC emissions remain poorly characterized. Here we characterize I/SVOC emissions from aircraft, using a novel instrument for the online, quantitative measurement of the mass loading and composition of low-volatility organic vapors. Emissions from the NASA DC8 aircraft were sampled on the ground 143 m downwind of the engines and characterized as a function of engine power from idle (4% maximum rated thrust through 85% power. Results show that I/SVOC emissions are highest during engine idle operating conditions, with decreasing but non-zero I/SVOC emissions at higher engine powers. Comparison of I/SVOC emissions with total hydrocarbon (THC measurements, VOC measurements, and an established emissions profile indicates that I/SVOCs comprise 10–20% of the total organic gas-phase emissions at idle, and an increasing fraction of the total gas-phase organic emissions at higher powers. Positive matrix factorization of online mass spectra is used to identify three distinct types of I/SVOC emissions: aliphatic, aromatic and oxygenated. The volatility and chemical composition of the emissions suggest that unburned fuel is the dominant source of I/SVOCs at idle, while pyrolysis products make up an increasing fraction of the I/SVOCs at higher powers. Oxygenated I/SVOC emissions were detected at lower engine powers (≤30% and may be linked to cracked, partially oxidized or unburned fuel components.

  11. Volatile organic compound (VOC) determination in working atmospheres; Determinacion de compuestos organicos volatiles (VOC) en ambiente laboral

    Energy Technology Data Exchange (ETDEWEB)

    Blass A, Georgina; Panama T, Luz A; Corrales C, Deyanira [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2003-07-01

    The present work describes, in a synthesized way, the implementation and application of procedures based on the normativity related to the subject of the volatile organic compounds (Volatile Organic Compounds VOC), that allow to sample, quantify and evaluate the present contamination in the working atmosphere of a refinery due to the fugitive emissions of VOC and other substances. In accordance with the corresponding normativity, more than 189 organic compounds denominated dangerous air polluting agents (Hazardous Air Pollutants, HAP) can be found in a working atmosphere, but they are the 11 main HAP that can be found in a refinery. In the present article the work made for the sampling and quantification of 5 of the 11 dangerous polluting agents of the air: benzene, toluene, xylene, iso-octane and naphthalene. [Spanish] El presente trabajo describe, de manera sintetizada, la implementacion y aplicacion de procedimientos basados en la normatividad relacionada al tema de los compuestos organicos volatiles (Volatil Organic Compounds, VOC), que permiten muestrear, cuantificar y evaluar la contaminacion presente en el ambiente laboral de una refineria debido a las emisiones fugitivas de VOC y otras sustancias. De acuerdo con la normatividad correspondiente, mas de 189 compuestos organicos denominados contaminantes peligrosos del aire (Hazardous Air Pollutants, HAP), pueden ser encontrados en un ambiente laboral, pero son 11 los principales HAP que pueden ser hallados en una refineria. En el presente articulo se informa el trabajo realizado para el muestreo y cuantificacion de 5 de los 11 contaminantes peligrosos del aire: benceno, tolueno, xileno, iso-octano y naftaleno.

  12. Online measurements of the emissions of intermediate-volatility and semi-volatile organic compounds from aircraft

    Directory of Open Access Journals (Sweden)

    E. S. Cross

    2013-03-01

    Full Text Available A detailed understanding of the climate and air quality impacts of aviation requires detailed measurements of the emissions of intermediate-volatility and semi-volatile organic compounds (I/SVOCs from aircraft. Currently both the amount and chemical composition of aircraft I/SVOC emissions remain poorly characterized. Here we characterize I/SVOC emissions from aircraft, using a novel instrument for the online, quantitative measurement of the mass loading and composition of low-volatility organic vapors. Emissions from the NASA DC8 aircraft were sampled on the ground, 143 m downwind of the engines and characterized as a function of engine power from ground idle (~4% maximum rated thrust through 85% power. Results show that I/SVOC emissions are highest during engine-idle operating conditions, with decreasing but non-zero I/SVOC emissions at higher engine powers. Comparison of I/SVOC emissions with total hydrocarbon (THC measurements, VOC measurements, and an established emissions profile indicates that I/SVOCs comprise 10–20% of the total organic gas phase emissions at idle, and an increasing fraction of the total gas phase organic emissions at higher powers. Positive matrix factorization of online mass spectra is used to identify three distinct types of I/SVOC emissions: aliphatic, aromatic and oxygenated. The volatility and chemical composition of the emissions suggest that unburned fuel is the dominant source of I/SVOCs at idle, while pyrolysis products make up an increasing fraction of the I/SVOCs at higher powers. Oxygenated I/SVOC emissions were detected at lower engine powers (≤30% and may be linked to cracked, partially oxidized or unburned fuel components.

  13. Characteristics of natural organic matter affect sorption of organic contaminants

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Several soil samples were used to study how the characteristics of natural organic matter (NOM) affect sorption of organic compounds. These soils contains different amounts and types of NOM. Aromaticity of NOM (percentage of aromatic carbons) was determined from solid-state CPMAS 13C NMR spectra and the soil effective polarity was computed from the equation developed by Xing et al. Naphthalene was used to examine the sorption characteristics of NOM. Both aromaticity and polarity of NOM strongly affected sorption of naphthalene. Old NOM showed higher affinity than that in the surface, young soils. Sorption increased with increasing aromaticity and decreasing polarity. Thus, the sorption coefficients of organic contaminants cannot be accurately predicted without some consideration of NOM characteristics.

  14. Screening of natural organic volatiles from Prunus mahaleb L. honey: coumarin and vomifoliol as nonspecific biomarkers

    National Research Council Canada - National Science Library

    Jerković, Igor; Marijanović, Zvonimir; Staver, Mladenka Malenica

    2011-01-01

    ...) were used for the analysis of Prunus mahaleb L. honey samples. Screening was focused toward chemical composition of natural organic volatiles to determine if it is useful as a method of determining honey-sourcing...

  15. Analysis of breath volatile organic compounds as a screening tool for detection of Tuberculosis in cattle

    Science.gov (United States)

    • Keywords: bovine tuberculosis; Mycobacterium bovis; breath analysis; volatile organic compound; gas chromatography; mass spectrometry; NaNose • Introduction: This presentation describes two studies exploring the use of breath VOCs to identify Mycobacterium bovis infection in cattle. • Methods: ...

  16. 78 FR 55234 - Approval and Promulgation of Implementation Plans; Indiana; Volatile Organic Compound Emission...

    Science.gov (United States)

    2013-09-10

    ... Compound Emission Control Measures for Industrial Solvent Cleaning for Northwest Indiana AGENCY... of Environmental Management (IDEM) submitted revisions to its volatile organic compound (VOC... less than or equal to 8 millimeters of mercury; (2) several work practices must be...

  17. Predicting partitioning of volatile organic compounds from air into plant cuticular matrix by quantum chemical descriptors

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on theoretical linear solvation energy relationship and quantum chemical descriptors computed by AM1 Hamiltonian, a new model is developed to predict the partitioning of some volatile organic compounds between the plant cuticular matrix and air.

  18. Factors that influence the volatile organic compound content in human breath

    NARCIS (Netherlands)

    Blanchet, L.; Smolinska, Agnieszka; Baranska, Agnieszka; Tigchelaar-Feenstra, E.; Swertz, M.; Zhernakova, A.; Dallinga, J. W.; Wijmenga, C.; van Schooten, Frederik J.

    Background. Thousands of endogenous and exogenous volatile organic compounds (VOCs) are excreted in each breath. Inflammatory and deviant metabolic processes affect the level of endogeneous VOCs, which can serve as specific biomarkers for clinical diagnosis and disease monitoring. Important issues

  19. PERTURBATION OF VOLTAGE-SENSITIVE Ca2+ CHANNEL FUNCTION BY VOLATILE ORGANIC SOLVENTS.

    Science.gov (United States)

    The mechanisms underlying the acute neurophysiological and behavioral effects of volatile organic compounds (VOCs) remain to be elucidated. However, the function of neuronal ion channels is perturbed by VOCs. The present study examined effects of toluene (TOL), trichloroethylene ...

  20. APPLICATION OF MICROWAVE IRRADIATION FOR THE TREATMENT OF ADSORBED VOLATILE ORGANIC COMPOUNDS ON GRANULAR ACTIVATED CARBON

    National Research Council Canada - National Science Library

    A Dehdashti; A Khavanin; A Rezaee; H Assilian; M Motalebi

    2011-01-01

      The purpose of this laboratory scale experimental research was to investigate the application of integrated microwave irradiation and granular activated carbon adsorption for removing volatile organic compounds (VOCs...

  1. Promotion of plant growth by Pseudomonas fluorescens strain SS101 via novel volatile organic compounds

    NARCIS (Netherlands)

    Park, Yong-Soon; Dutta, Swarnalee; Ann, Mina; Raaijmakers, Jos M.; Park, Kyungseok

    2015-01-01

    Abstract Volatile organic compounds (VOCs) from plant growth-promoting rhizobacteria (PGPR) play key roles in modulating plant growth and induced systemic resistance (ISR) to pathogens. Despite their significance, the physiological functions of the specific VOCs produced by Pseudomonas fluorescens

  2. PERTURBATION OF VOLTAGE-SENSITIVE Ca2+ CHANNEL FUNCTION BY VOLATILE ORGANIC SOLVENTS.

    Science.gov (United States)

    The mechanisms underlying the acute neurophysiological and behavioral effects of volatile organic compounds (VOCs) remain to be elucidated. However, the function of neuronal ion channels is perturbed by VOCs. The present study examined effects of toluene (TOL), trichloroethylene ...

  3. PERTURBATION OF VOLTAGE-SENSITIVE CALCIUM FUNCTION IN PHEOCHROMOCYTOMA CELLS BY VOLATILE ORGANIC SOLVENTS.

    Science.gov (United States)

    Volatile organic solvents such as toluene (TOL) and trichloroethylene perturb nervous system function and share characteristic effects with other central nervous system depressants such as anesthetic gasses, ethanol, benzodiazepines and barbiturates. Recently, mechanistic studies...

  4. VOLATILE ORGANIC COMPOUNDS INHIBIT HUMAN AND RAT NEURONAL NICOTINIC ACETYLCHOLINE RECEPTORS EXPRESSED IN XENOPUS OOCYTES.

    Science.gov (United States)

    This manuscript provides evidence to indicate that rats and humans are equally sensitive at the pharmacodynamic level to effects of volatile organic compounds.? This manuscript also presents novel data that provides a plausible mechanism, disruption of ion channel functi...

  5. VOLATILE ORGANIC COMPOUND EMISSION RATES FROM MIXED DECIDUOUS AND CONIFEROUS FORESTS IN NORTHERN WISCONSIN, USA

    Science.gov (United States)

    Biogenic emissions of volatile organic compounds (VOC) from forests play an important role in regulating the atmospheric trace gas composition including global tropospheric ozone concentrations. However, more information is needed on VOC emission rates from different forest regio...

  6. Effect of Organic Matter on Manganese Solubility

    Directory of Open Access Journals (Sweden)

    Emilene Andrade

    2002-03-01

    Full Text Available The objective of this study was to re-evaluate some aspects of the relative importance of organic matter on Mn solubility in acid soil conditions. Field study showed that black oats, oil seed radish, elephant grass, lupin, leucaena, and coffee leaves serving as mulch decreased Mn solubility as compared with bare soil. The decrease in Mn solubility with plant mulch was related to increase in soil moisture content. Laboratory study showed that increasing temperature from 25 to 100ºC increased Mn solubility and total soil organic carbon was little changed; from 150 to 200ºC increased both Mn solubility and organic carbon oxidation, and up to 300ºC decreased Mn solubility and stoped organic carbon oxidation . Aluminum solubility always increased with increasing temperature. Organic matter exerted a control in both Mn and Al solubilities in acid soils.O estudo foi conduzido com objetivo de reavaliar alguns aspectos da importância relativa da matéria orgânica na solubilidade do Mn em solos ácidos. Em condição de campo cobertura morta com resíduos de aveia preta, nabo forrageiro, napier, tremoço, leucena e folhas de café diminuíram a solubilidade de Mn quando comparada com o solo descoberto. A redução na solubilidade do Mn em solo coberto com resíduos vegetais foi relacionada com o teor de umidade do solo. Estudos de laboratório demonstraram que o aumento da temperatura de 25 para 100ºC aumentou a solubilidade do Mn com pouca alteração no teor de carbono do solo; de 150 a 200ºC aumentou ambas a solubilidade do Mn e a oxidação do carbono orgânico e acima de 300ºC diminuiu a solubilidade do Mn e completou a oxidação do carbono orgânico. A solubilidade do Al sempre aumentou com a elevação da temperatura. A matéria orgânica influenciou diretamente a solubilidade do Mn e do Al.

  7. Starting life requires more than organic matter

    Science.gov (United States)

    Pascal, R.

    2015-10-01

    A physicochemical approach is proposed to study requirements for the origin of life in agreement with developments made in Systems Chemistry for several decades. Emphasis is made on the occurrence of environments generating abiotic chemical systems making more of themselves under far from equilibrium conditions. It follows that the presence of organic matter is only one of the components needed for the process of chemical evolution leading to life. The presence of an energy source with a potential equivalent to that of visible light is needed to render the activation step kinetically irreversible and the reproduction loop a unidirectional flux of reactants. This condition is required in order that reproduction follows an exponential law and dynamic kinetic stability governs the evolution toward the selection of improved variants. According to these views, no fundamental difference can be found between the chemical and biological stages of evolution.

  8. Dynamic measurement of coal thermal properties and elemental composition of volatile matter during coal pyrolysis

    Directory of Open Access Journals (Sweden)

    Rohan Stanger

    2014-01-01

    Full Text Available A new technique that allows dynamic measurement of thermal properties, expansion and the elemental chemistry of the volatile matter being evolved as coal is pyrolysed is described. The thermal and other properties are measured dynamically as a function of temperature of the coal without the need for equilibration at temperature. In particular, the technique allows for continuous elemental characterisation of tars as they are evolved during pyrolysis and afterwards as a function of boiling point. The technique is demonstrated by measuring the properties of maceral concentrates from a coal. The variation in heats of reaction, thermal conductivity and expansion as a function of maceral composition is described. Combined with the elemental analysis, the results aid in the interpretation of the chemical processes contributing to the physical and thermal behaviour of the coal during pyrolysis. Potential applications in cokemaking studies are discussed.

  9. Volatile Organic Compound Investigation Results, 300 Area, Hanford Site, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Robert E.; Williams, Bruce A.; Smith, Ronald M.

    2008-07-07

    Unexpectedly high concentrations of volatile organic compounds (VOC) were discovered while drilling in the unconfined aquifer beneath the Hanford Site’s 300 Area during 2006. The discovery involved an interval of relatively finer-grained sediment within the unconfined aquifer, an interval that is not sampled by routine groundwater monitoring. Although VOC contamination in the unconfined aquifer has been identified and monitored, the concentrations of newly discovered contamination are much higher than encountered previously, with some new results significantly higher than the drinking water standards. The primary contaminant is trichloroethene, with lesser amounts of tetrachloroethene. Both chemicals were used extensively as degreasing agents during the fuels fabrication process. A biological degradation product of these chemicals, 1,2-dichloroethene, was also detected. To further define the nature and extent of this contamination, additional characterization drilling was undertaken during 2007. Four locations were drilled to supplement the information obtained at four locations drilled during the earlier investigation in 2006. The results of the combined drilling indicate that the newly discovered contamination is limited to a relatively finer-grained interval of Ringold Formation sediment within the unconfined aquifer. The extent of this contamination appears to be the area immediately east and south of the former South Process Pond. Samples collected from the finer-grained sediment at locations along the shoreline confirm the presence of the contamination near the groundwater/river interface. Contamination was not detected in river water that flows over the area where the river channel potentially incises the finer-grained interval of aquifer sediment. The source for this contamination is not readily apparent. A search of historical documents and the Hanford Waste Information Data System did not provide definitive clues as to waste disposal operations and

  10. Airborne flux measurements of biogenic volatile organic compounds over California

    Science.gov (United States)

    Misztal, P. K.; Karl, T.; Weber, R.; Jonsson, H. H.; Guenther, A. B.; Goldstein, A. H.

    2014-03-01

    Biogenic Volatile Organic Compound (BVOC) fluxes were measured onboard the CIRPAS Twin Otter aircraft as part of the California Airborne BVOC Emission Research in Natural Ecosystem Transects (CABERNET) campaign during June 2011. The airborne virtual disjunct eddy covariance (AvDEC) approach used measurements from a PTR-MS and a wind radome probe to directly determine fluxes of isoprene, MVK + MAC, methanol, monoterpenes, and MBO over ∼10 000 km of flight paths focusing on areas of California predicted to have the largest emissions of isoprene. The Fast Fourier Transform (FFT) approach was used to calculate fluxes over long transects of more than 15 km, most commonly between 50 and 150 km. The Continuous Wavelet Transformation (CWT) approach was used over the same transects to also calculate "instantaneous" fluxes with localization of both frequency and time independent of non-stationarities. Vertical flux divergence of isoprene is expected due to its relatively short lifetime and was measured directly using "racetrack" profiles at multiple altitudes. It was found to be linear and in the range 5% to 30% depending on the ratio of aircraft altitude to PBL height (z / zi). Fluxes were generally measured by flying consistently at 400 ± 50 m (a.g.l.) altitude, and extrapolated to the surface according to the determined flux divergence. The wavelet-derived surface fluxes of isoprene averaged to 2 km spatial resolution showed good correspondence to Basal Emission Factor (BEF) landcover datasets used to drive biogenic VOC (BVOC) emission models. The surface flux of isoprene was close to zero over Central Valley crops and desert shrublands, but was very high (up to 15 mg m-2 h-1) above oak woodlands, with clear dependence of emissions on temperature and oak density. Isoprene concentrations of up to 8 ppb were observed at aircraft height on the hottest days and over the dominant source regions. While isoprene emissions from agricultural crop regions, shrublands, and

  11. Effects of trace volatile organic compounds on methane oxidation

    Directory of Open Access Journals (Sweden)

    Wilai Chiemchaisri

    2001-06-01

    Full Text Available The effects of volatile organic compounds (VOCs on methane oxidation in landfill cover soils were examined. The batch experiments were conducted using single and mixed VOCs, such as, dichloromethane (DCM, trichloroethylene (TCE, tetrachloroethylene (PCE, and benzene. The results from all combinations showed a decrease in methane oxidation rate with increase in VOC concentrations. Moreover, inhibition effects of TCE and DCM were found higher than benzene and PCE. The reduction of methane oxidation by benzene and PCE could be attributed to the toxicity effect, whereas TCE and DCM were found to exhibit the competitive-inhibition effect. When the soil was mixed with DCM, no methane oxidation was found. Damage to the cell’s internal membrane was found in a methanotrophic culture exposed to VOC gases which is the attachment site of a key enzyme needed for methane oxidationOs efeitos dos compostos orgânicos voláteis (VOCs na oxidação do metano em camadas superficiais do solo. Os experimentos foram conduzidos usando somente VOCs ou mistura do mesmo, como, diclorometano (DCM, tricloroetileno (TCE, tetracloroetileno (PCE, e benzeno. Os resultados de todas as combinações mostraram uma diminuição na taxa da oxidação do metano com aumento nas concentrações de VOC. Além disso, os efeitos da inibição de TCE e de DCM foram mais elevados do que do benzeno e PCE. A redução da oxidação do metano pelo benzeno e PCE poderia ser atribuída ao efeito da toxicidade, visto que TCE e DCM exibiram o efeito de competição-inibição. Quando o solo foi misturado com o DCM, nenhuma oxidação do metano foi encontrada. Os danos à membrana interna celular foi observada em uma cultura metanotrófica exposta aos gases de VOC que é o local de ligação de uma enzima chave necessário para a oxidação do metano.

  12. [Determination of Alcoholysis Degree and Volatile Matter of Poly-Vinyl Alcohol Using Diffuse-Reflection Near Infrared Spectroscopy].

    Science.gov (United States)

    Xie, Jin-chun; Yuan, Hong-fu; Yan, Xiang-jun; Zhao, Xin-liang; Song, Chun-feng; Wang, Xiao-ming; Li, Xiao-yu

    2016-01-01

    A new method using reflection NIR technology was developed to determine the alcoholysis degree and volatile matter of Poly-vinyl alcohol (PVA). 120 samples were used in this research. NIR spectra of the sample were scanned by the spectrometer from 1 000 to 1 800 nm. The alcoholysis degree and volatile matter were determined by the national standard method of volumetric and gravimetric method respectivily. Partial least squares (PLS1) was used to establish the quantitative correction model of alcoholysis degree and volatile matter of PVA. The corrected relationship (Rc) of alcoholysis degree and volatile matter was 0.976 and 0.981 respectively. The corrected standard deviation(SEC) was 0.176 and 0.197. The predicted relationship (R(p)) was 0.967 and 0.969. The predicted deviation(SEP) was 0.202 and 0.193. The test for actual samples showed that the NIR method was fitted for the requirement of PVA analysis.

  13. Rapid changes of induced volatile organic compounds in Pinus massoniana

    Institute of Scientific and Technical Information of China (English)

    REN Qin; JIN Youju; HU Yongiian; CHEN Huajun; LI Zhenyu

    2007-01-01

    Using the thermal-desorption cold trap gas chromatography/mass spectrometer(TCT-GC-MS)technique,the composition and relative contents of volatile compounds were analyzed in undamaged(control),insect-damaged(ID)and artificially-damaged(AD)leaves ofPinus massoniana in field at different times and levels of damage.Results showed that although volatile substances were highly released earlier in AD leaves plants,they were significantly less abundant in AD than in ID leaves treatments.Also,the damage level considerably influenced the changes of induced volatile products from leaves.Compared with the control,the emission rate of camphene,β-pinene,phellandrene,caryophyllene and(E)farnesene was high after 1 h in 25%-40% ID-affected leaves,whereas that of tricyclene,myrcene,camphene,β-Pinene,phellandrene and caryophyllene reached its maximum after 24 h in 60%-75% D-affected leaves.In the same manner,some volatile compounds in the AD leaves treatment displayed their peaks just after 1 h,but others after 24 h.The AD and ID leaves at the damage level of 25%-40% did not exhibit an obvious regularity with time;however,in 60%- 75% AD leaves,peaks of volatile substances were attained after 1 or 2 h.Our results also showed that the relative content ofβ-pinene increased and was higher in damaged than control plants,β-pinene plays an important role in inducing the insect resistance of P.massoniana trees.

  14. Organic nitrate aerosol formation via NO3 + biogenic volatile organic compounds in the southeastern United States

    Science.gov (United States)

    Ayres, B. R.; Allen, H. M.; Draper, D. C.; Brown, S. S.; Wild, R. J.; Jimenez, J. L.; Day, D. A.; Campuzano-Jost, P.; Hu, W.; de Gouw, J.; Koss, A.; Cohen, R. C.; Duffey, K. C.; Romer, P.; Baumann, K.; Edgerton, E.; Takahama, S.; Thornton, J. A.; Lee, B. H.; Lopez-Hilfiker, F. D.; Mohr, C.; Wennberg, P. O.; Nguyen, T. B.; Teng, A.; Goldstein, A. H.; Olson, K.; Fry, J. L.

    2015-12-01

    Gas- and aerosol-phase measurements of oxidants, biogenic volatile organic compounds (BVOCs) and organic nitrates made during the Southern Oxidant and Aerosol Study (SOAS campaign, Summer 2013) in central Alabama show that a nitrate radical (NO3) reaction with monoterpenes leads to significant secondary aerosol formation. Cumulative losses of NO3 to terpenes are correlated with increase in gas- and aerosol-organic nitrate concentrations made during the campaign. Correlation of NO3 radical consumption to organic nitrate aerosol formation as measured by aerosol mass spectrometry and thermal dissociation laser-induced fluorescence suggests a molar yield of aerosol-phase monoterpene nitrates of 23-44 %. Compounds observed via chemical ionization mass spectrometry (CIMS) are correlated to predicted nitrate loss to BVOCs and show C10H17NO5, likely a hydroperoxy nitrate, is a major nitrate-oxidized terpene product being incorporated into aerosols. The comparable isoprene product C5H9NO5 was observed to contribute less than 1 % of the total organic nitrate in the aerosol phase and correlations show that it is principally a gas-phase product from nitrate oxidation of isoprene. Organic nitrates comprise between 30 and 45 % of the NOy budget during SOAS. Inorganic nitrates were also monitored and showed that during incidents of increased coarse-mode mineral dust, HNO3 uptake produced nitrate aerosol mass loading at a rate comparable to that of organic nitrate produced via NO3 + BVOCs.

  15. Comprehensive characterization of atmospheric organic matter in Fresno, California fog water

    Science.gov (United States)

    Herckes, P.; Leenheer, J.A.; Collett, J.L.

    2007-01-01

    Fogwater collected during winter in Fresno (CA) was characterized by isolating several distinct fractions and characterizing them by infrared and nuclear magnetic resonance (NMR) spectroscopy. More than 80% of the organic matter in the fogwater was recovered and characterized. The most abundant isolated fractions were those comprised of volatile acids (24% of isolated carbon) and hydrophilic acids plus neutrals (28%). Volatile acids, including formic and acetic acid, have been previously identified as among the most abundant individual species in fogwater. Recovered hydrophobic acids exhibited some properties similar to aquatic fulvic acids. An insoluble particulate organic matter fraction contained a substantial amount of biological material, while hydrophilic and transphilic fractions also contained material suggestive of biotic origin. Together, these fractions illustrate the important contribution biological sources make to organic matter in atmospheric fog droplets. The fogwater also was notable for containing a large amount of organic nitrogen present in a variety of species, including amines, nitrate esters, peptides, and nitroso compounds. ?? 2007 American Chemical Society.

  16. Improved exposure estimation in soil screening and clean-up criteria for volatile organic chemicals.

    Science.gov (United States)

    DeVaull, George E

    2017-02-18

    Soil clean-up criteria define acceptable concentrations of organic chemical constituents for exposed humans. These criteria sum the estimated soil exposure over multiple pathways. Assumptions for ingestion, dermal contact, and dust exposure generally presume a chemical persists in surface soils at a constant concentration level for the entire exposure duration. For volatile chemicals this is an unrealistic assumption. A calculation method is presented for surficial soil criteria which include volatile depletion of chemical for these uptake pathways. The depletion estimates compare favorably with measured concentration profiles and with field measurements of soil concentration. Corresponding volatilization estimates compare favorably with measured data for a wide range of volatile and semi-volatile chemicals, including instances with and without the presence of a mixed-chemical residual phase. Selected examples show application of the revised factors in estimating screening levels for benzene in surficial soils. This article is protected by copyright. All rights reserved.

  17. Pyrolysis-combustion 14C dating of soil organic matter

    Science.gov (United States)

    Wang, Hong; Hackley, Keith C.; Panno, Samuel V.; Coleman, Dennis D.; Liu, Jack Chao-li; Brown, Johnie

    2003-11-01

    Radiocarbon ( 14C) dating of total soil organic matter (SOM) often yields results inconsistent with the stratigraphic sequence. The onerous chemical extractions for SOM fractions do not always produce satisfactory 14C dates. In an effort to develop an alternative method, the pyrolysis-combustion technique was investigated to partition SOM into pyrolysis volatile (Py-V) and pyrolysis residue (Py-R) fractions. The Py-V fractions obtained from a thick glacigenic loess succession in Illinois yielded 14C dates much younger but more reasonable than the counterpart Py-R fractions for the soil residence time. Carbon isotopic composition (δ 13C) was heavier in the Py-V fractions, suggesting a greater abundance of carbohydrate- and protein-related constituents, and δ 13C was lighter in the Py-R fractions, suggesting more lignin- and lipid-related constituents. The combination of 14C dates and δ 13C values indicates that the Py-V fractions are less biodegradation resistant and the Py-R fractions are more biodegradation resistant. The pyrolysis-combustion method provides a less cumbersome approach for 14C dating of SOM fractions. With further study, this method may become a useful tool for analyzing unlithified terrestrial sediments when macrofossils are absent.

  18. Contributions of individual reactive biogenic volatile organic compounds to organic nitrates above a mixed forest

    Directory of Open Access Journals (Sweden)

    K. A. Pratt

    2012-11-01

    Full Text Available Biogenic volatile organic compounds (BVOCs can react in the atmosphere to form organic nitrates, which serve as NOx (NO + NO2 reservoirs, impacting ozone and secondary organic aerosol production, the oxidative capacity of the atmosphere, and nitrogen availability to ecosystems. To examine the contributions of biogenic emissions and the formation and fate of organic nitrates in a forest environment, we simulated the oxidation of 57 individual BVOCs emitted from a rural mixed forest in northern Michigan. Key BVOC-oxidant reactions were identified for future laboratory and field investigations into reaction rate constants, yields, and speciation of oxidation products. Of the total simulated organic nitrates, monoterpenes contributed ~70% in the early morning at ~12 m above the forest canopy when isoprene emissions were low. In the afternoon, when vertical mixing and isoprene nitrate production were highest, the simulated contribution of isoprene-derived organic nitrates was greater than 90% at all altitudes, with the concentration of secondary isoprene nitrates increasing with altitude. Notably, reaction of isoprene with NO3 leading to isoprene nitrate formation was found to be significant (~8% of primary organic nitrate production during the daytime, and monoterpene reactions with NO3 were simulated to comprise up to ~83% of primary organic nitrate production at night. Lastly, forest succession, wherein aspen trees are being replaced by pine and maple trees, was predicted to lead to increased afternoon concentrations of monoterpene-derived organic nitrates. This further underscores the need to understand the formation and fate of these species, which have different chemical pathways and oxidation products compared to isoprene-derived organic nitrates and can lead to secondary organic aerosol formation.

  19. Investigating Photosensitized Properties of Natural Organic Matter and Effluent Organic Matter

    KAUST Repository

    Niu, Xi-Zhi

    2013-05-01

    The photosensitized processes significantly enhance photolysis of various chemicals in the aqueous system with dissolved organic matter (DOM) as sensitizer. The excitation of chromophores on the DOM molecule further generates reactive species as triplet states DOM, singlet oxygen, hydroxyl radical, carbonate radical etc. We investigated the photosensitization properties of Beaufort Fulvic Acid, Suwannee River Fulvic Acid, South Platte River Fulvic Acid, and Jeddah wastewater treatment plant effluent organic matter with a sunlight simulator. DOM photochemical properties were characterized by observing their performances in 3DOM*, singlet oxygen, hydroxyl radical production with indirect probing protocols. Sensitized degradation of 0.1 μM and 0.02 μM 2, 4, 6- Trimethylphenol exhibited higher pseudo-first-order rate constant than that of 10 μM. Pre-irradiated DOMs were found to be depressed in photochemical properties. Photolysis of 5 different contaminants: ibuprofen, bisphenol A, acetaminophen, cimetidine, and caffeine were found to be enhanced in the presence of sensitizers. The possible reaction pathways were revealed. Long time irradiance induced change in contaminants degradation kinetics in some DOM solutions, which was proposed to be due to the irradiation initiated indirect transformation of DOMs. Key Words: Photolysis Dissolved Organic Matter, Triplet State DOM, Singlet Oxygen, Hydroxyl Radical, Contaminants Degradation.

  20. Concentrations and flux measurements of volatile organic compounds (VOC) in boreal forest soil

    Science.gov (United States)

    Mäki, Mari; Aaltonen, Hermanni; Heinonsalo, Jussi; Hellén, Heidi; Pumpanen, Jukka; Bäck, Jaana

    2017-04-01

    and August. Organic soil is formed by organic matter which contains energy rich compounds for microbial decomposition and fine root biomass is also highest in soil surface (Helmisaari et al., 2007). With these analyses, we aim at distinguishing the VOC sinks and sources in the soil layers and quantifying the potential role of VOC uptake by soil microbiota. Asensio, D., Yuste, J. C., Mattana, S., Ribas, À., Llusià, J., and Peñuelas, J.: Litter VOCs induce changes in soil microbial biomass C and N and largely increase soil CO2 efflux. Plant and soil, 360(1-2), 163-174, doi:10.1007/s11104-012-1220-9, 2012. Ditengou, F. A., Müller, A., Rosenkranz, M., Felten, J., Lasok, H., van Doorn, M. M., Legue, V., Palme, K., Schnitzler, J.-P., and Polle, A. Volatile signalling by sesquiterpenes from ectomycorrhizal fungi reprogrammes root architecture. Nature communications, 6:6279, doi:10.1038/ncomms7279, 2015. Helmisaari, H. S., Derome, J., Nöjd, P., & Kukkola, M.: Fine root biomass in relation to site and stand characteristics in Norway spruce and Scots pine stands. Tree Physiology, 27(10), 1493-1504, 2007. Hung, R., Lee, S., and Bennett, J. W.: Arabidopsis thaliana as a model system for testing the effect of Trichoderma volatile organic compounds. Fungal Ecology, 6(1), 19-26, doi:10.1016/j.funeco.2012.09.005, 2013.

  1. [Emission model of volatile organic compounds from materials used indoors].

    Science.gov (United States)

    Han, K

    1998-11-30

    Various materials, such as wall-paper, floor-wax, paint, multicolor wall-coat, air freshener and mothball were experimented in a simulated test chamber under constant selected temperature, humidity and air exchange rate. The relation between the total VOCs concentration and time was regressed by four emission models and the surface emission rate was calculated. The regressed results indicated the similarity among four emission models for the liquid materials with volatile-solvent such as paint and multicolor wall-coat. But for low volatile solid materials, such as wall-paper, floor-wax, mothball, the sink model and the empirical model were better than the dilution model and vapor pressure model. Only for air freshener, it was improper to the total VOCs concentration as a parameter.

  2. RT-MATRIX: Measuring Total Organic Carbon by Photocatalytic Oxidation of Volatile Organic Compounds

    Science.gov (United States)

    2008-01-01

    Volatile organic compounds (VOCs) inevitably accumulate in enclosed habitats such as the International Space Station and the Crew Exploration Vehicle (CEV) as a result of human metabolism, material off-gassing, and leaking equipment. Some VOCs can negatively affect the quality of the crew's life, health, and performance; and consequently, the success of the mission. Air quality must be closely monitored to ensure a safe living and working environment. Currently, there is no reliable air quality monitoring system that meets NASA's stringent requirements for power, mass, volume, or performance. The ultimate objective of the project -- the development of a Real-Time, Miniaturized, Autonomous Total Risk Indicator System (RT.MATRIX).is to provide a portable, dual-function sensing system that simultaneously determines total organic carbon (TOC) and individual contaminants in air streams.

  3. Adsorption of volatile organic compounds in porous metal-organic frameworks functionalized by polyoxometalates

    Science.gov (United States)

    Ma, Feng-Ji; Liu, Shu-Xia; Liang, Da-Dong; Ren, Guo-Jian; Wei, Feng; Chen, Ya-Guang; Su, Zhong-Min

    2011-11-01

    The functionalization of porous metal-organic frameworks (Cu 3( BTC) 2) was achieved by incorporating Keggin-type polyoxometalates (POMs), and further optimized via alkali metal ion-exchange. In addition to thermal gravimetric analysis, IR, single-crystal X-ray diffraction, and powder X-ray diffraction, the adsorption properties were characterized by N 2 and volatile organic compounds (VOCs) adsorption measurements, including short-chain alcohols ( C<4), cyclohexane, benzene, and toluene. The adsorption enthalpies estimated by the modified Clausius-Clapeyron equation provided insight into the impact of POMs and alkali metal cations on the adsorption of VOCs. The introduction of POMs not only improved the stability, but also brought the increase of adsorption capacity by strengthening the interaction with gas molecules. Furthermore, the exchanged alkali metal cations acted as active sites to interact with adsorbates and enhanced the adsorption of VOCs.

  4. Control of postharvest Botrytis fruit rot of strawberry by volatile organic compounds of Candida intermedia.

    Science.gov (United States)

    Huang, R; Li, G Q; Zhang, J; Yang, L; Che, H J; Jiang, D H; Huang, H C

    2011-07-01

    A study was conducted to identify volatile organic compounds or volatiles produced by Candida intermedia strain C410 using gas chromatography-mass spectrometry, and to determine efficacy of the volatiles of C. intermedia in suppression of conidial germination and mycelial growth of Botrytis cinerea and control of Botrytis fruit rot of strawberry. Results showed that, among 49 volatiles (esters, alcohols, alkenes, alkanes, alkynes, organic acids, ketones, and aldehydes) identified from C. intermedia cultures on yeast extract peptone dextrose agar, two compounds, 1,3,5,7-cyclooctatetraene and 3-methyl-1-butanol, were the most abundant. Synthetic chemicals of 1,3,5,7-cyclooctatetraene; 3-methyl-1-butanol; 2-nonanone; pentanoic acid, 4-methyl-, ethyl ester; 3-methyl-1-butanol, acetate; acetic acid, pentyl ester; and hexanoic acid, ethyl ester were highly inhibitory to conidial germination and mycelial growth of B. cinerea. Inhibition of conidial germination and mycelial growth of B. cinerea by volatiles of C. intermedia was also observed. Meanwhile, results showed that incidence and severity of Botrytis fruit rot of strawberry was significantly (P fruit to the volatiles from C. intermedia cultures or C. intermedia-infested strawberry fruit. These results suggest that the volatiles of C. intermedia C410 are promising biofumigants for control of Botrytis fruit rot of strawberry.

  5. Effects of airborne volatile organic compounds on plants.

    Science.gov (United States)

    Cape, J N

    2003-01-01

    Routine measurements of volatile organic compounds (VOCs) in air have shown that average concentrations are very much smaller than those used in laboratory experiments designed to study the effects of VOCs on plants. However, maximum hourly concentrations of some VOCs can be 100 times larger than the average, even in rural air. Experimental studies have rarely extended for longer than a few days, so there is little information on potential long-term effects of exposure to small concentrations. This review considers the available evidence for long-term effects, based on laboratory and field data. Previous reviews of the literature from Germany and the USA are cited, prior to an assessment of the effects of individual VOCs. Although hydrocarbons from vehicle exhausts have been implicated in the observed effects on roadside vegetation, the evidence suggests that it is the nitrogen oxides in the exhaust gases that are mostly responsible. There is evidence that aromatic hydrocarbons can be metabolised in plants, although the fate of the metabolites is not known. There is a large literature on the effects of ethylene, because of its role as a plant hormone. Effects have been reported in the field, in response to industrial emissions, and dose-response experiments over several weeks in laboratory studies have clearly identified the potential for effects at ambient concentrations. The main responses are morphological (e.g. epinasty), which may be reversible, and on the development of flowers and fruit. Effects on seed production may be positive or negative, depending on the exposure concentration. Chlorinated hydrocarbons have been identified as potentially harmful to vegetation, but only one long-term experiment has studied dose-response relationships. As for ethylene, the most sensitive indication of effect was on seed production, although long-term accumulation of trichloroacetic acid in tissue may also be a problem. There is little evidence of the direct effects of

  6. Airborne flux measurements of biogenic volatile organic compounds over California

    Directory of Open Access Journals (Sweden)

    P. K. Misztal

    2014-03-01

    Full Text Available Biogenic Volatile Organic Compound (BVOC fluxes were measured onboard the CIRPAS Twin Otter aircraft as part of the California Airborne BVOC Emission Research in Natural Ecosystem Transects (CABERNET campaign during June 2011. The airborne virtual disjunct eddy covariance (AvDEC approach used measurements from a PTR-MS and a wind radome probe to directly determine fluxes of isoprene, MVK + MAC, methanol, monoterpenes, and MBO over ∼10 000 km of flight paths focusing on areas of California predicted to have the largest emissions of isoprene. The Fast Fourier Transform (FFT approach was used to calculate fluxes over long transects of more than 15 km, most commonly between 50 and 150 km. The Continuous Wavelet Transformation (CWT approach was used over the same transects to also calculate "instantaneous" fluxes with localization of both frequency and time independent of non-stationarities. Vertical flux divergence of isoprene is expected due to its relatively short lifetime and was measured directly using "racetrack" profiles at multiple altitudes. It was found to be linear and in the range 5% to 30% depending on the ratio of aircraft altitude to PBL height (z / zi. Fluxes were generally measured by flying consistently at 400 ± 50 m (a.g.l. altitude, and extrapolated to the surface according to the determined flux divergence. The wavelet-derived surface fluxes of isoprene averaged to 2 km spatial resolution showed good correspondence to Basal Emission Factor (BEF landcover datasets used to drive biogenic VOC (BVOC emission models. The surface flux of isoprene was close to zero over Central Valley crops and desert shrublands, but was very high (up to 15 mg m−2 h−1 above oak woodlands, with clear dependence of emissions on temperature and oak density. Isoprene concentrations of up to 8 ppb were observed at aircraft height on the hottest days and over the dominant source regions. While isoprene emissions from agricultural crop regions

  7. Analytical modeling of the subsurface volatile organic vapor concentration in vapor intrusion

    OpenAIRE

    Shen, Rui; Pennell, Kelly G.; Suuberg, Eric M.

    2013-01-01

    The inhalation of volatile and semi-volatile organic compounds that intrude from a subsurface contaminant source into indoor air has become the subject of health and safety concerns over the last twenty years. Building subslab and soil gas contaminant vapor concentration sampling have become integral parts of vapor intrusion field investigations. While numerical models can be of use in analyzing field data and in helping understand the subslab and soil gas vapor concentrations, they are not w...

  8. Comparison of Methanol and Tetraglyme as Extraction Solvents for Determination of Volatile Organics in Soil

    Science.gov (United States)

    1987-11-01

    determining volatile organics in soil can be classified into thefollowing groups: 1. Static or dynamic headspace analysis 2. Solvent extraction-direct...methods based on the dynamic headspace method whereby the volatiles are stripped from a soil/water slurry using a conventional purge-and-trap instrument...651. Brazell, R.S. and MP. Maskarinec (1981) Dynamic headspace analysis of solid waste materials. Journal of High Resolution Chromatography and

  9. Mapping forest soil organic matter on New Jersey's coastal plain

    Science.gov (United States)

    Brian J. Clough; Edwin J. Green; Richard B. Lathrop

    2012-01-01

    Managing forest soil organic matter (SOM) stocks is a vital strategy for reducing the impact of anthropogenic carbon dioxide emissions. However, the SOM pool is highly variable, and developing accurate estimates to guide management decisions has remained a difficult task. We present the results of a spatial model designed to map soil organic matter for all forested...

  10. Seasonal distribution of organic matter in mangrove environment of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Jagtap, T.G.

    Water and sediments were studied for the distribution of suspended matter, organic carbon and nitrogen Suspended matter ranged from 3-373 mg.l-1 while particulate organic carbon (POC) from 0.03-9.94 mg.l-1 POC value showed significant correlation...

  11. Modeling organic aerosols in a megacity: potential contribution of semi-volatile and intermediate volatility primary organic compounds to secondary organic aerosol formation

    Directory of Open Access Journals (Sweden)

    A. Hodzic

    2010-06-01

    Full Text Available It has been established that observed local and regional levels of secondary organic aerosols (SOA in polluted areas cannot be explained by the oxidation and partitioning of anthropogenic and biogenic VOC precursors, at least using current mechanisms and parameterizations. In this study, the 3-D regional air quality model CHIMERE is applied to estimate the potential contribution to SOA formation of recently identified semi-volatile and intermediate volatility organic precursors (S/IVOC in and around Mexico City for the MILAGRO field experiment during March 2006. The model has been updated to include explicitly the volatility distribution of primary organic aerosols (POA, their gas-particle partitioning and the gas-phase oxidation of the vapors. Two recently proposed parameterizations, those of Robinson et al. (2007 ("ROB" and Grieshop et al. (2009 ("GRI" are compared and evaluated against surface and aircraft measurements. The 3-D model results are assessed by comparing with the concentrations of OA components from Positive Matrix Factorization of Aerosol Mass Spectrometer (AMS data, and for the first time also with oxygen-to-carbon ratios derived from high-resolution AMS measurements. The results show a substantial enhancement in predicted SOA concentrations (2–4 times with respect to the previously published base case without S/IVOCs (Hodzic et al., 2009, both within and downwind of the city leading to much reduced discrepancies with the total OA measurements. Model improvements in OA predictions are associated with the better-captured SOA magnitude and diurnal variability. The predicted production from anthropogenic and biomass burning S/IVOC represents 40–60% of the total measured SOA at the surface during the day and is somewhat larger than that from commonly measured aromatic VOCs, especially at the T1 site at the edge of the city. The SOA production from the continued multi-generation S/IVOC oxidation products continues actively

  12. Chemically-resolved volatility measurements of organic aerosol fom different sources.

    Science.gov (United States)

    Huffman, J A; Docherty, K S; Mohr, C; Cubison, M J; Ulbrich, I M; Ziemann, P J; Onasch, T B; Jimenez, J L

    2009-07-15

    A newly modified fast temperature-stepping thermodenuder (TD) was coupled to a High Resolution Time-of-Flight Aerosol Mass Spectrometer for rapid determination of chemically resolved volatility of organic aerosols (OA) emitted from individual sources. The TD-AMS system was used to characterize primary OA (POA) from biomass burning, trash burning surrogates (paper and plastic), and meat cooking as well as chamber-generated secondary OA (SOA) from alpha-pinene and gasoline vapor. Almost all atmospheric models represent POA as nonvolatile, with no allowance for evaporation upon heating or dilution, or condensation upon cooling. Our results indicate that all OAs observed show semivolatile behavior and that most POAs characterized here were at least as volatile as SOA measured in urban environments. Biomass-burning OA (BBOA) exhibited a wide range of volatilities, but more often showed volatility similar to urban OA. Paper-burning resembles some types of BBOA because of its relatively high volatility and intermediate atomic oxygen-to-carbon (O/C) ratio, while meat-cooking OAs (MCOA) have consistently lower volatility than ambient OA. Chamber-generated SOA under the relatively high concentrations used intraditional experiments was significantly more volatile than urban SOA, challenging extrapolation of traditional laboratory volatility measurements to the atmosphere. Most OAs sampled show increasing O/C ratio and decreasing H/C (hydrogen-to-carbon) ratio with temperature, further indicating that more oxygenated OA components are typically less volatile. Future experiments should systematically explore a wider range of mass concentrations to more fully characterize the volatility distributions of these OAs.

  13. Environmental Aspects of Two Volatile Organic Compound Groundwater Treatment Designs at the Rocky Flats Site - 13135

    Energy Technology Data Exchange (ETDEWEB)

    Michalski, Casey C.; DiSalvo, Rick; Boylan, John [Stoller LMS Team, 11025 Dover Street, Suite 1000, Westminster, CO 80021 (United States)

    2013-07-01

    DOE's Rocky Flats Site in Colorado is a former nuclear weapons production facility that began operations in the early 1950's. Because of releases of hazardous substances to the environment, the federally owned property and adjacent offsite areas were placed on the CERCLA National Priorities List in 1989. The final remedy was selected in 2006. Engineered components of the remedy include four groundwater treatment systems that were installed before closure as CERCLA-accelerated actions. Two of the systems, the Mound Site Plume Treatment System and the East Trenches Plume Treatment System, remove low levels of volatile organic compounds using zero-valent iron media, thereby reducing the loading of volatile organic compounds in surface water resulting from the groundwater pathway. However, the zero-valent iron treatment does not reliably reduce all volatile organic compounds to consistently meet water quality goals. While adding additional zero-valent iron media capacity could improve volatile organic compound removal capability, installation of a solar powered air-stripper has proven an effective treatment optimization in further reducing volatile organic compound concentrations. A comparison of the air stripper to the alternative of adding additional zero-valent iron capacity to improve Mound Site Plume Treatment System and East Trenches Plume Treatment System treatment based on several key sustainable remediation aspects indicates the air stripper is also more 'environmentally friendly'. These key aspects include air pollutant emissions, water quality, waste management, transportation, and costs. (authors)

  14. Demonstration of Novel Sampling Techniques for Measurement of Turbine Engine Volatile and Non-Volatile Particulate Matter (PM) Emissions

    Science.gov (United States)

    2015-12-30

    comparing the size distributions of particles obtained at the VPS outlet to those from a bypass tube of the same length. An ideal volatile particle...E-14 Bias Valve Calibration Gases 3-Way Bypass Valve Filter 8 Lpm 8 Lpm 3 Lpm Teflon Filter Sampler (Mass + SO4) Pump Teflon Filter Sampler (Mass...Calibration Gases Rear Door CA Analytical THC LI-COR CO2 Vent Pump Ecotech SO2 Pump (a) (b

  15. Enhanced Volatile Organic Compounds emissions and organic aerosol mass increase the oligomer content of atmospheric aerosols

    Science.gov (United States)

    Kourtchev, Ivan; Giorio, Chiara; Manninen, Antti; Wilson, Eoin; Mahon, Brendan; Aalto, Juho; Kajos, Maija; Venables, Dean; Ruuskanen, Taina; Levula, Janne; Loponen, Matti; Connors, Sarah; Harris, Neil; Zhao, Defeng; Kiendler-Scharr, Astrid; Mentel, Thomas; Rudich, Yinon; Hallquist, Mattias; Doussin, Jean-Francois; Maenhaut, Willy; Bäck, Jaana; Petäjä, Tuukka; Wenger, John; Kulmala, Markku; Kalberer, Markus

    2016-10-01

    Secondary organic aerosol (SOA) accounts for a dominant fraction of the submicron atmospheric particle mass, but knowledge of the formation, composition and climate effects of SOA is incomplete and limits our understanding of overall aerosol effects in the atmosphere. Organic oligomers were discovered as dominant components in SOA over a decade ago in laboratory experiments and have since been proposed to play a dominant role in many aerosol processes. However, it remains unclear whether oligomers are relevant under ambient atmospheric conditions because they are often not clearly observed in field samples. Here we resolve this long-standing discrepancy by showing that elevated SOA mass is one of the key drivers of oligomer formation in the ambient atmosphere and laboratory experiments. We show for the first time that a specific organic compound class in aerosols, oligomers, is strongly correlated with cloud condensation nuclei (CCN) activities of SOA particles. These findings might have important implications for future climate scenarios where increased temperatures cause higher biogenic volatile organic compound (VOC) emissions, which in turn lead to higher SOA mass formation and significant changes in SOA composition. Such processes would need to be considered in climate models for a realistic representation of future aerosol-climate-biosphere feedbacks.

  16. Productions of Volatile Organic Compounds (VOCs) in Surface Waters from Reactions with Atmospheric Ozone

    Science.gov (United States)

    Hopkins, Frances; Bell, Thomas; Yang, Mingxi

    2017-04-01

    Ozone (O3) is a key atmospheric oxidant, greenhouse gas and air pollutant. In marine environments, some atmospheric ozone is lost by reactions with aqueous compounds (e.g. dissolved organic material, DOM, dimethyl sulfide, DMS, and iodide) near the sea surface. These reactions also lead to formations of volatile organic compounds (VOCs). Removal of O3 by the ocean remains a large uncertainty in global and regional chemical transport models, hampering coastal air quality forecasts. To better understand the role of the ocean in controlling O3 concentrations in the coastal marine atmosphere, we designed and implemented a series of laboratory experiments whereby ambient surface seawater was bubbled with O3-enriched, VOC-free air in a custom-made glass bubble equilibration system. Gas phase concentrations of a range of VOCs were monitored continuously over the mass range m/z 33 - 137 at the outflow of the bubble equilibrator by a proton transfer reaction - mass spectrometer (PTR-MS). Gas phase O3 was also measured at the input and output of the equilibrator to monitor the uptake due to reactions with dissolved compounds in seawater. We observed consistent productions of a variety of VOCs upon reaction with O3, notably isoprene, aldehydes, and ketones. Aqueous DMS is rapidly removed from the reactions with O3. To test the importance of dissolved organic matter precursors, we added increasing (milliliter) volumes of Emiliania huxleyi culture to the equilibrator filled with aged seawater, and observed significant linear increases in gas phase concentrations of a number of VOCs. Reactions between DOM and O3 at the sea-air interface represent a potentially significant source of VOCs in marine air and a sink of atmospheric O3.

  17. Dissolved Organic Matter and Emerging Contaminants in Urban Stream Ecosystems

    Science.gov (United States)

    Kaushal, S. S.; Findlay, S.; Groffman, P.; Belt, K.; Delaney, K.; Sides, A.; Walbridge, M.; Mayer, P.

    2009-05-01

    We investigated the effects of urbanization on the sources, bioavailability and forms of natural and anthropogenic organic matter found in streams located in Maryland, U.S.A. We found that the abundance, biaoavailability, and enzymatic breakdown of dissolved organic carbon (DOC), dissolved organic nitrogen (DON), and dissolved organic phosphorus (DOP) increased in streams with increasing watershed urbanization suggesting that organic nutrients may represent a growing form of nutrient loading to coastal waters associated with land use change. Organic carbon, nitrogen, and phosphorus in urban streams were elevated several-fold compared to forest and agricultural streams. Enzymatic activities of stream microbes in organic matter decomposition were also significantly altered across watershed land use. Chemical characterization suggested that organic matter in urban streams originated from a variety of sources including terrestrial, sewage, and in-stream transformation. In addition, a characterization of emerging organic contaminants (polyaromatic cyclic hydrocarbons, organochlorine pesticides, and polybrominated diphenyl ether flame retardents), showed that organic contaminants and dissolved organic matter increase with watershed urbanization and fluctuate substantially with changing climatic conditions. Elucidating the emerging influence of urbanization on sources, transport, and in-stream transformation of organic nutrients and contaminants will be critical in unraveling the changing role of organic matter in urban degraded and restored stream ecosystems.

  18. Vehicular emissions of organic particulate matter in Sao Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    B. S. Oyama

    2015-12-01

    Full Text Available Vehicular emissions have a strong impact on air pollution in big cities. Many factors affect these emissions: type of vehicle, type of fuel, cruising velocity, and brake use. This study focused on emissions of organic compounds by Light (LDV and Heavy (HDV duty vehicle exhaust. The study was performed in the city of Sao Paulo, Brazil, where vehicles run on different fuels: gasoline with 25 % ethanol (called gasohol, hydrated ethanol, and diesel (with 5 % of biodiesel. The vehicular emissions are an important source of pollutants and the principal contribution to fine particulate matter (smaller than 2.5 μm, PM2.5 in Sao Paulo. The experiments were performed in two tunnels: Janio Quadros (TJQ where 99 % of the vehicles are LDV, and Rodoanel Mario Covas (TRA where up to 30 % of the fleet was HDV. The PM2.5 samples were collected on quartz filters in May and July 2011 at TJQ and TRA, respectively, using two samplers operating in parallel. The samples were analyzed by Thermal-Desorption Proton-Transfer-Reaction Mass-Spectrometry (TD-PTR-MS, and by Thermal-Optical Transmittance (TOT. The organic aerosol (OA desorbed at TD-PTR-MS represented around 30 % of the OA estimated by the TOT method, mainly due to the different desorption temperatures, with a maximum of 870 and 350 °C for TOT and TD-PTR-MS, respectively. Average emission factors (EF organic aerosol (OA and organic carbon (OC were calculated for HDV and LDV fleet. We found that HDV emitted more OA and OC than LDV, and that OC emissions represented 36 and 43 % of total PM2.5 emissions from LDV and HDV, respectively. More than 700 ions were identified by TD-PTR-MS and the EF profiles obtained from HDV and LDV exhibited distinct features. Nitrogen-containing compounds measured in the desorbed material up to 350 °C contributed around 20 % to the EF values for both types of vehicles, possibly associated with incomplete fuel burning. Additionally, 70 % of the organic compounds measured from the

  19. Vehicular emissions of organic particulate matter in Sao Paulo, Brazil

    Science.gov (United States)

    Oyama, B. S.; Andrade, M. F.; Herckes, P.; Dusek, U.; Röckmann, T.; Holzinger, R.

    2015-12-01

    Vehicular emissions have a strong impact on air pollution in big cities. Many factors affect these emissions: type of vehicle, type of fuel, cruising velocity, and brake use. This study focused on emissions of organic compounds by Light (LDV) and Heavy (HDV) duty vehicle exhaust. The study was performed in the city of Sao Paulo, Brazil, where vehicles run on different fuels: gasoline with 25 % ethanol (called gasohol), hydrated ethanol, and diesel (with 5 % of biodiesel). The vehicular emissions are an important source of pollutants and the principal contribution to fine particulate matter (smaller than 2.5 μm, PM2.5) in Sao Paulo. The experiments were performed in two tunnels: Janio Quadros (TJQ) where 99 % of the vehicles are LDV, and Rodoanel Mario Covas (TRA) where up to 30 % of the fleet was HDV. The PM2.5 samples were collected on quartz filters in May and July 2011 at TJQ and TRA, respectively, using two samplers operating in parallel. The samples were analyzed by Thermal-Desorption Proton-Transfer-Reaction Mass-Spectrometry (TD-PTR-MS), and by Thermal-Optical Transmittance (TOT). The organic aerosol (OA) desorbed at TD-PTR-MS represented around 30 % of the OA estimated by the TOT method, mainly due to the different desorption temperatures, with a maximum of 870 and 350 °C for TOT and TD-PTR-MS, respectively. Average emission factors (EF) organic aerosol (OA) and organic carbon (OC) were calculated for HDV and LDV fleet. We found that HDV emitted more OA and OC than LDV, and that OC emissions represented 36 and 43 % of total PM2.5 emissions from LDV and HDV, respectively. More than 700 ions were identified by TD-PTR-MS and the EF profiles obtained from HDV and LDV exhibited distinct features. Nitrogen-containing compounds measured in the desorbed material up to 350 °C contributed around 20 % to the EF values for both types of vehicles, possibly associated with incomplete fuel burning. Additionally, 70 % of the organic compounds measured from the aerosol

  20. Methods for Determining Organic Matter and Colour in Water

    Directory of Open Access Journals (Sweden)

    Ramunė Albrektienė

    2011-02-01

    Full Text Available The article examines different methods for determining organic matter and colour in water. Most of organic compounds in water have a humic substance. These substances frequently form complexes with iron. Humic matter gives water a yellow-brownish colour. Water filtration through conventional sand filters does not remove colour and organic compounds, and therefore complicated water treatment methods shall be applied. The methods utilized for organic matter determination in water included research on total organic carbon, permanganate index and the bichromate number of UV absorption of 254 nm wave length. The obtained results showed the greatest dependence between water colour and permanganate index. However, UV adsorption could be used for organic matter determination during the operation of a water treatment plant and the start-up of plants as easy and fast methods.Article in Lithuanian

  1. Changes in River Organic Matter Through Time.

    Science.gov (United States)

    Hudson, N.; Baker, A.; Ward, D.

    2006-12-01

    fluorescence, as an increase in pH was also observed in these samples. This work illustrates the dynamic character of river organic matter within a timescale and under conditions that are representative of the natural system.

  2. Variations in organic matter bound in fluffy layer suspended matter from the Pomeranian Bay (Baltic Sea

    Directory of Open Access Journals (Sweden)

    Ksenia Pazdro

    2001-12-01

    Full Text Available Fluffy layer suspended matter (FLSM and surface sediment samples from the Pomeranian Bay were examined for fatty acid, lipid and organic matter contents. FLSM is a several-centimetre-thick layer of fairly concentrated particulate matter lying on the sea floor significantly affecting the flux of matter to depositional basins. Analyses of fatty acids were used to establish sources and decomposition rates of labile organic matter along a transect from the shallow, highly dynamic, Odra estuary to the Arkona Basin, a deep, low energy, depositional area. In FLSM and sediments respectively, the ranges of organic matter contents were 4.0-25.0% and 5.1-23.0%, those of lipids 0.1-5.4% and 0.30-1.67%, and those of fatty acids 50-991 µg g-1 dry wt. and 100-546 µg g-1 dry wt. In shallow waters, the contents of these compounds are very variable, mirroring variations in biological activity and hydrological conditions. The high percentage of polyunsaturated fatty acids in shallow areas indicates the presence of fresh, undegraded, labile organic matter of autochthonous origin. Fatty acids, the most labile components, are transported as suspended matter attached to minerals and finally accumulated in the depositional area in the form of condensed organic macromolecules. The intensity of bacterial decomposition of organic matter in this system is reflected in the high percentage of branched fatty acids. The low fatty acid content in the organic matter is attributed to the high rate of decomposition of the labile organic matter. No linear correlation was found between the contents of fatty acids and lipids.

  3. Effect of granular activated carbon concentration on the content of organic matter and salt, influencing E. coli activity and survival in fluidized bed disinfection reactor

    NARCIS (Netherlands)

    Racyte, J.; Langenhoff, A.A.M.; Ribeiro, A.F.M.M.R.; Paulitsch-Fuchs, A.H.; Bruning, H.; Rijnaarts, H.

    2014-01-01

    Granular activated carbon (GAC) is used in water treatment systems, typically to remove pollutants such as natural organic matter, volatile organic compounds, chlorine, taste, and odor. GAC is also used as a key component of a new technology that combines a fluidized bed reactor with radio frequency

  4. Volatile organic compounds released by blowfly larvae and pupae: new perspectives in forensic entomology.

    Science.gov (United States)

    Frederickx, C; Dekeirsschieter, J; Brostaux, Y; Wathelet, J-P; Verheggen, F J; Haubruge, E

    2012-06-10

    To evaluate postmortem intervals (PMIs), one should take into account the determined age of necrophagous flies present on the cadaver. However, PMI determination needs further improvement, and rapid and accurate approaches have therefore to be developed. While previous studies have focussed on insect cuticular hydrocarbons, here we explore the volatile profile released by larvae and pupae of Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae). We monitored changes in volatile compounds daily, by headspace solid-phase microextraction, followed by gas chromatography-mass spectrometry. Branched and unbranched hydrocarbons, alcohols, esters and acids were identified, and the volatile profile was shown to vary, in both composition and quantity, with the age of the larva/pupa under investigation. We concluded, based on the analysis of the released volatile organic compounds, that it is possible to increase the accuracy of the estimated PMI, through improved estimation of the age of blowflies present on the cadaver.

  5. Nitrate radicals and biogenic volatile organic compounds: oxidation, mechanisms, and organic aerosol

    Science.gov (United States)

    Ng, Nga Lee; Brown, Steven S.; Archibald, Alexander T.; Atlas, Elliot; Cohen, Ronald C.; Crowley, John N.; Day, Douglas A.; Donahue, Neil M.; Fry, Juliane L.; Fuchs, Hendrik; Griffin, Robert J.; Guzman, Marcelo I.; Herrmann, Hartmut; Hodzic, Alma; Iinuma, Yoshiteru; Jimenez, José L.; Kiendler-Scharr, Astrid; Lee, Ben H.; Luecken, Deborah J.; Mao, Jingqiu; McLaren, Robert; Mutzel, Anke; Osthoff, Hans D.; Ouyang, Bin; Picquet-Varrault, Benedicte; Platt, Ulrich; Pye, Havala O. T.; Rudich, Yinon; Schwantes, Rebecca H.; Shiraiwa, Manabu; Stutz, Jochen; Thornton, Joel A.; Tilgner, Andreas; Williams, Brent J.; Zaveri, Rahul A.

    2017-02-01

    Oxidation of biogenic volatile organic compounds (BVOC) by the nitrate radical (NO3) represents one of the important interactions between anthropogenic emissions related to combustion and natural emissions from the biosphere. This interaction has been recognized for more than 3 decades, during which time a large body of research has emerged from laboratory, field, and modeling studies. NO3-BVOC reactions influence air quality, climate and visibility through regional and global budgets for reactive nitrogen (particularly organic nitrates), ozone, and organic aerosol. Despite its long history of research and the significance of this topic in atmospheric chemistry, a number of important uncertainties remain. These include an incomplete understanding of the rates, mechanisms, and organic aerosol yields for NO3-BVOC reactions, lack of constraints on the role of heterogeneous oxidative processes associated with the NO3 radical, the difficulty of characterizing the spatial distributions of BVOC and NO3 within the poorly mixed nocturnal atmosphere, and the challenge of constructing appropriate boundary layer schemes and non-photochemical mechanisms for use in state-of-the-art chemical transport and chemistry-climate models. This review is the result of a workshop of the same title held at the Georgia Institute of Technology in June 2015. The first half of the review summarizes the current literature on NO3-BVOC chemistry, with a particular focus on recent advances in instrumentation and models, and in organic nitrate and secondary organic aerosol (SOA) formation chemistry. Building on this current understanding, the second half of the review outlines impacts of NO3-BVOC chemistry on air quality and climate, and suggests critical research needs to better constrain this interaction to improve the predictive capabilities of atmospheric models.

  6. Nitrate radicals and biogenic volatile organic compounds: oxidation, mechanisms, and organic aerosol

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Nga Lee; Brown, Steven S.; Archibald, Alexander T.; Atlas, Elliot; Cohen, Ronald C.; Crowley, John N.; Day, Douglas A.; Donahue, Neil M.; Fry, Juliane L.; Fuchs, Hendrik; Griffin, Robert J.; Guzman, Marcelo I.; Herrmann, Hartmut; Hodzic, Alma; Iinuma, Yoshiteru; Jimenez, José L.; Kiendler-Scharr, Astrid; Lee, Ben H.; Luecken, Deborah J.; Mao, Jingqiu; McLaren, Robert; Mutzel, Anke; Osthoff, Hans D.; Ouyang, Bin; Picquet-Varrault, Benedicte; Platt, Ulrich; Pye, Havala O. T.; Rudich, Yinon; Schwantes, Rebecca H.; Shiraiwa, Manabu; Stutz, Jochen; Thornton, Joel A.; Tilgner, Andreas; Williams, Brent J.; Zaveri, Rahul A.

    2017-01-01

    Oxidation of biogenic volatile organic compounds (BVOC) by the nitrate radical (NO3) represents one of the important interactions between anthropogenic emissions related to combustion and natural emissions from the biosphere. This interaction has been recognized for more than 3 decades, during which time a large body of research has emerged from laboratory, field, and modeling studies. NO3-BVOC reactions influence air quality, climate and visibility through regional and global budgets for reactive nitrogen (particularly organic nitrates), ozone, and organic aerosol. Despite its long history of research and the significance of this topic in atmospheric chemistry, a number of important uncertainties remain. These include an incomplete understanding of the rates, mechanisms, and organic aerosol yields for NO3-BVOC reactions, lack of constraints on the role of heterogeneous oxidative processes associated with the NO3 radical, the difficulty of characterizing the spatial distributions of BVOC and NO3 within the poorly mixed nocturnal atmosphere, and the challenge of constructing appropriate boundary layer schemes and non-photochemical mechanisms for use in state-of-the-art chemical transport and chemistry–climate models.

    This review is the result of a workshop of the same title held at the Georgia Institute of Technology in June 2015. The first half of the review summarizes the current literature on NO3-BVOC chemistry, with a particular focus on recent advances in instrumentation and models, and in organic nitrate and secondary organic aerosol (SOA) formation chemistry. Building on this current understanding, the second half of the review outlines impacts of NO3-BVOC chemistry on air quality and climate, and suggests critical research needs to better constrain this interaction to improve the predictive capabilities of atmospheric models.

  7. Volatile organic metabolites identify patients with breast cancer, cyclomastopathy, and mammary gland fibroma.

    Science.gov (United States)

    Wang, Changsong; Sun, Bo; Guo, Lei; Wang, Xiaoyang; Ke, Chaofu; Liu, Shanshan; Zhao, Wei; Luo, Suqi; Guo, Zhigang; Zhang, Yang; Xu, Guowang; Li, Enyou

    2014-06-20

    The association between cancer and volatile organic metabolites in exhaled breaths has attracted increasing attention from researchers. The present study reports on a systematic study of gas profiles of metabolites in human exhaled breath by pattern recognition methods. Exhaled breath was collected from 85 patients with histologically confirmed breast disease (including 39 individuals with infiltrating ductal carcinoma, 25 individuals with cyclomastopathy and from 21 individuals with mammary gland fibroma) and 45 healthy volunteers. Principal component analysis and partial least squares discriminant analysis were used to process the final data. The volatile organic metabolites exhibited significant differences between breast cancer and normal controls, breast cancer and cyclomastopathy, and breast cancer and mammary gland fibroma; 21, 6, and 8 characteristic metabolites played decisive roles in sample classification, respectively (P fibroma patients, and patients with cyclomastopathy (P < 0.05). The identified three volatile organic metabolites associated with breast cancer may serve as novel diagnostic biomarkers.

  8. 78 FR 62451 - Air Quality: Revision to Definition of Volatile Organic Compounds-Exclusion of 2,3,3,3...

    Science.gov (United States)

    2013-10-22

    ... AGENCY 40 CFR Part 51 RIN 2060-AR70 Air Quality: Revision to Definition of Volatile Organic Compounds.... SUMMARY: The EPA is taking final action to revise the regulatory definition of volatile organic compounds... those organic compounds of carbon that form ozone through atmospheric photochemical reactions....

  9. Volatile organic compounds of polyethylene vinyl acetate plastic are toxic to living organisms.

    Science.gov (United States)

    Meng, Tingzhu Teresa

    2014-01-01

    Volatile organic compounds (VOCs) in polyvinyl chloride (PVC) plastic products readily evaporate; as a result, hazardous gases enter the ecosystem, and cause cancer in humans and other animals. Polyethylene vinyl acetate (PEVA) plastic has recently become a popular alternative to PVC since it is chlorine-free. In order to determine whether PEVA is harmful to humans, this research employed the freshwater oligochaete Lumbriculus variegatus as a model to compare their oxygen intakes while they were exposed to the original stock solutions of PEVA, PVC or distilled water at a different length of time for one day, four days or eight days. During the exposure periods, the oxygen intakes in both PEVA and PVC groups were much higher than in the distilled water group, indicating that VOCs in both PEVA and PVC were toxins that stressed L. variegatus. Furthermore, none of the worms fully recovered during the24-hr recovery period. Additionally, the L. variegatus did not clump together tightly after four or eight days' exposure to either of the two types of plastic solutions, which meant that both PEVA and PVC negatively affected the social behaviors of these blackworms. The LD50 tests also supported the observations above. For the first time, our results have shown that PEVA plastic has adverse effects on living organisms, and therefore it is not a safe alternative to PVC. Further studies should identify specific compounds causing the adverse effects, and determine whether toxic effect occurs in more complex organisms, especially humans.

  10. Degradation of natural organic matter: A thermodynamic analysis

    Science.gov (United States)

    LaRowe, Douglas E.; Van Cappellen, Philippe

    2011-04-01

    The oxidative degradation of organic matter is a key process in the biogeochemical functioning of the earth system. Quantitative models of organic matter degradation are therefore essential for understanding the chemical state and evolution of the Earth's near-surface environment, and to forecast the biogeochemical consequences of ongoing regional and global change. The complex nature of biologically produced organic matter represents a major obstacle to the development of such models, however. Here, we compare the energetics of the oxidative degradation of a large number of naturally occurring organic compounds. By relating the Gibbs energies of half reactions describing the complete mineralization of the compounds to their average nominal carbon oxidation state, it becomes possible to estimate the energetic potential of the compounds based on major element (C, H, N, O, P, S) ratios. The new energetic description of organic matter can be combined with bioenergetic theory to rationalize observed patterns in the decomposition of natural organic matter. For example, the persistence of cell membrane derived compounds and complex organics in anoxic settings is consistent with their limited catabolic potential under these environmental conditions. The proposed approach opens the way to include the thermodynamic properties of organic compounds in kinetic models of organic matter degradation.

  11. Sensory and Physiological Effects on Humans of Combined Exposures to Air Temperatures and Volatile Organic Compounds

    DEFF Research Database (Denmark)

    Mølhave, Lars; Liu, Zunyong; Jørgensen, Anne Hempel

    1993-01-01

    Ten healthy humans were exposed to combinations of volatile organic compounds (VOCs) and air temperature (0 mg/m3 and 10 mg/m3 of a mixture of 22 volatile organic compounds and 18, 22 and 26° C). Previously demonstrated effects of VOCs and thermal exposures were replicated. For the first time nasal...... cross-sectional areas and nasal volumes, as measured by acoustic rhinometry, were shown to decrease with decreasing temperature and increasing VOC exposure. Temperature and pollutant exposures affected air quality, the need for more ventilation, skin humidity on the forehead, sweating, acute sensory...

  12. Is resistant soil organic matter more sensitive to temperature than the labile organic matter?

    Directory of Open Access Journals (Sweden)

    C. Fang

    2006-01-01

    Full Text Available A recent paper by Knorr et al. (2005a suggested that the decomposition of resistant soil organic matter is more temperature sensitive than labile organic matter. In Knorr et al.'s (2005a model, the reference decay rate was presumed to be same for all pools of soil carbon. We refit Knorr et al.'s (2005a model but allow both the activation energy and the reference decay rate to vary among soil C pools. Under these conditions, a similar fit to measured data can be obtained without invoking the assumption that the resistant C pool is more temperature sensitive than the labile pool. Other published evidence does not unequivocally support Knorr et al.'s (2005a hypothesis of increased temperature sensitivity of resistant pools of soil carbon. Because of the lack of experimental data, Knorr et al.'s (2005a conclusion that the decomposition of the resistant SOM is more temperature sensitive than the labile pool is premature.

  13. 碰碰香挥发物化学成分分析%Chemical components of Plectranthus tomentosa volatile matters

    Institute of Scientific and Technical Information of China (English)

    熊伟; 金荷仙; 蔡宝珍

    2011-01-01

    为探明碰碰香Plectranthus tomentosa叶片挥发物的组成及其相对含量,以长势优的成年碰碰香为研究对象,采用顶空套袋法,并在热脱附系统(TDS)条件下用气相色谱-质谱联用仪(GC-MS)对收集气体进行分析检测.测出叶片挥发物有44种,包括烷烃、烯烃等8类化合物,烯烃中的萜烯类化合物有22种(相对含量为83.32%),其中柠檬烯含量最多(相对含量为47.61%);同时结合保留指数分析碰碰香叶片挥发物化学成分,比单独使用GC-MS其结果更加准确可靠.%This study was conducted to determine the composition of volatile matter from leaves of Plectranthus tomentosa and the relative contribution to its aromatherapy. The dynamic headspace collection method for total dissolved solids (TDS), was used to extract volatile matter of adult P. Tomentosa in good condition, and a gas chromatograph-mass spectrometer (GC-MS) was utilized to detect the composition of the extract. Results showed 44 kinds of volatile matter including eight types of compounds, such as alkanes and olefins. Also, 22 types of terpenoids (relative content of 83.32%)were found with Limonene having the highest level of simple carbohydrates (relative content of 47.61%). Thus, this work demonstrated that a retention index of P. Tomentosa volatile matter from leaves could provide a complementary and convenient method for accurate analysis, which may be helpful for the further exploitation.

  14. Particulate organic matter in the sea: the composition conundrum.

    Science.gov (United States)

    Lee, Cindy; Wakeham, Stuart; Arnosti, Carol

    2004-12-01

    As organic matter produced in the euphotic zone of the ocean sinks through the mesopelagic zone, its composition changes from one that is easily characterized by standard chromatographic techniques to one that is not. The material not identified at the molecular level is called "uncharacterized". Several processes account for this transformation of organic matter: aggregation/disaggregation of particles resulting in incorporation of older and more degraded material; recombination of organic compounds into geomacromolecules; and selective preservation of specific biomacromolecules. Furthermore, microbial activities may introduce new cell wall or other biomass material that is not easily characterized, or they may produce such material as a metabolic product. In addition, black carbon produced by combustion processes may compose a fraction of the uncharacterized organic matter, as it is not analyzed in standard biochemical techniques. Despite these poorly-defined compositional changes that hinder chemical identification, the vast majority of organic matter in sinking particles remains accessible to and is ultimately remineralized by marine microbes.

  15. Interstellar chemistry recorded in organic matter from primitive meteorites.

    Science.gov (United States)

    Busemann, Henner; Young, Andrea F; Alexander, Conel M O'd; Hoppe, Peter; Mukhopadhyay, Sujoy; Nittler, Larry R

    2006-05-05

    Organic matter in extraterrestrial materials has isotopic anomalies in hydrogen and nitrogen that suggest an origin in the presolar molecular cloud or perhaps in the protoplanetary disk. Interplanetary dust particles are generally regarded as the most primitive solar system matter available, in part because until recently they exhibited the most extreme isotope anomalies. However, we show that hydrogen and nitrogen isotopic compositions in carbonaceous chondrite organic matter reach and even exceed those found in interplanetary dust particles. Hence, both meteorites (originating from the asteroid belt) and interplanetary dust particles (possibly from comets) preserve primitive organics that were a component of the original building blocks of the solar system.

  16. Exploratory Research - Using Volatile Organic Compounds to Separate Heterotrophic and Autotrophic Forest Soil Respiration

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Scott D [Mississippi State Univ., Mississippi State, MS (United States)

    2015-02-09

    The initial focus of this project was to develop a method to partition soil respiration into its components (autotrophic, heterotrophic etc.) using the fingerprint of volatile organic compounds (VOCs) from soils. We were able to identify 63 different VOCs in our study; however, due to technical difficulties we were unable to take reliable measurements in order to test our hypotheses and develop this method. In the end, we changed the objectives of the project. Our new objectives were to characterize the effects of species and soil moisture regime on the composition of soil organic matter. We utilized the soils from the greenhouse experiment we had established for the soil VOC study and determined the lignin biomarker profiles of each of the treatments. We found that moisture had a significant effect on the carbon content of the soils with the low moisture treatments having higher carbon content than the high moisture treatments. We found that the relative yield of syringyl phenols (SP), ligin (Lig), and substituted fatty acids (SFA) were elevated in deciduous planted pots and reduced in conifer planted pots relative to plant-free treatments. Our results suggest nuttall oak preserved lignin and SFA, while loblolly pine lost lignin and SFA similarly to the plant free treatments. Since we did not find that the carbon concentrations of the soils were different between the species, nuttall oak probably replaced more native soil carbon than loblolly pine. This suggests that relative to loblolly pine, nuttall oak is a priming species. Since priming may impact soil carbon pools more than temperature or moisture, determining which species are priming species may facilitate an understanding of the interaction that land use and climate change may have on soil carbon pools.

  17. Pyrogenic organic matter can alter microbial communication

    Science.gov (United States)

    Masiello, Caroline; Gao, Xiaodong; Cheng, Hsiao-Ying; Silberg, Jonathan

    2016-04-01

    Soil microbes communicate with each other to manage a large range of processes that occur more efficiently when microbes are able to act simultaneously. This coordination occurs through the continuous production of signaling compounds that are easily diffused into and out of cells. As the number of microbes in a localized environment increases, the internal cellular concentration of these signaling compounds increases, and when a threshold concentration is reached, gene expression shifts, leading to altered (and coordinated) microbial behaviors. Many of these coordinated behaviors have biogeochemically important outcomes. For example, methanogenesis, denitrification, biofilm formation, and the development of plant-rhizobial symbioses are all regulated by a simple class of cell-cell signaling molecules known as acyl homoserine lactones (AHLs). Pyrogenic organic matter in soils can act to disrupt microbial communication through multiple pathways. In the case of AHLs, charcoal's very high surface area can sorb these signaling compounds, preventing microbes from detecting each others' presence (Masiello et al., 2014). In addition, the lactone ring in AHLs is vulnerable to pH increases accompanying PyOM inputs, with soil pH values higher than 7-8 leading to ring opening and compound destabilization. Different microbes use different classes of signaling compounds, and not all microbial signaling compounds are pH-vulnerable. This implies that PyOM-driven pH increases may trigger differential outcomes for Gram negative bacteria vs fungi, for example. A charcoal-driven reduction in microbes' ability to detect cell-cell communication compounds may lead to a shift in the ability of microbes to participate in key steps of C and N cycling. For example, an increase in an archaeon-specific AHL has been shown to lead to a cascade of metabolic processes that eventually results in the upregulation of CH4 production (Zhang et al., 2012). Alterations in similar AHL compounds leads to

  18. Development of an In-Fiber Nanocavity Towards Detection of Volatile Organic Gases

    OpenAIRE

    Arregui, Francisco J.; Candido Bariain; Matias, Ignacio R; Cesar Elosua

    2006-01-01

    A fiber optic sensor for Volatile Organic Compounds (VOCs) detection has been developed and characterized for some organic gasses. The sensor is based on a novel vapochromic material, which is able to change its optical properties in presence of organic vapors in a reversely way. A nano Fabry Perot is constructed onto a cleaved ended optical fiber pigtail by Electrostatic Self Assembly method (ESA), doping this structure with the vapochromic material. Employing a reflection scheme, a chang...

  19. Role of Aerosol Liquid Water in Secondary Organic Aerosol Formation from Volatile Organic Compounds.

    Science.gov (United States)

    Faust, Jennifer A; Wong, Jenny P S; Lee, Alex K Y; Abbatt, Jonathan P D

    2017-02-07

    A key mechanism for atmospheric secondary organic aerosol (SOA) formation occurs when oxidation products of volatile organic compounds condense onto pre-existing particles. Here, we examine effects of aerosol liquid water (ALW) on relative SOA yield and composition from α-pinene ozonolysis and the photooxidation of toluene and acetylene by OH. Reactions were conducted in a room-temperature flow tube under low-NOx conditions in the presence of equivalent loadings of deliquesced (∼20 μg m(-3) ALW) or effloresced (∼0.2 μg m(-3) ALW) ammonium sulfate seeds at exactly the same relative humidity (RH = 70%) and state of wall conditioning. We found 13% and 19% enhancements in relative SOA yield for the α-pinene and toluene systems, respectively, when seeds were deliquesced rather than effloresced. The relative yield doubled in the acetylene system, and this enhancement was partially reversible upon drying the prepared SOA, which reduced the yield by 40% within a time scale of seconds. We attribute the high relative yield of acetylene SOA on deliquesced seeds to aqueous partitioning and particle-phase reactions of the photooxidation product glyoxal. The observed range of relative yields for α-pinene, toluene, and acetylene SOA on deliquesced and effloresced seeds suggests that ALW plays a complicated, system-dependent role in SOA formation.

  20. Performance of rotating drum biofilter for volatile organic compound removal at high organic loading rates

    Institute of Scientific and Technical Information of China (English)

    YANG Chunping; CHEN Hong; ZENG Guangming; ZHU Xueqing; SUIDAN Makram T

    2008-01-01

    Uneven distribution of volatile organic compounds (VOCs) and biomass,and excess biomass accumulation in some biofilters hinder the application of biofiltration technology.An innovative multilayer rotating drum biofilter (RDB) was developed to correct these problems.The RDB was operated at an empty bed contact time (EBCT) of 30 s and a rotational rate of 1.0 r/rain.Diethyl ether was chosen as the model VOC.Performance of the RDB was evaluated at organic loading rates of 32.1,64.2,128,and 256 g ether/(m3·h) (16.06 g ether/(m3·h) ≈1.0 kg chemical oxygen demand (COD)/(m3·d)).The EBCT and organic loading rates were recorded on the basis of the medium volume.Results show that the ether removal efficiency decreased with an increased VOC loading rate.Ether removal efficiencies exceeding 99% were achieved without biomass control even at a high VOC loading rate of 128 g ether/(m3·h). However,when the VOC loading rate was increased to 256 g ether/(m3·h),the average removal efficiency dropped to 43%.Nutrient limitation possibly contributed to the drop in ether removal efficiency.High biomass accumulation rate was also observed in the medium at the two higher ether loading rates,and removal of the excess biomass in the media was necessary to maintain stable performance. This work showed that the RDB is effective in the removal of diethyl ether from waste gas streams even at high organic loading rates. The results might help establish criteria for designing and operating RDBs.

  1. Removal of volatile organic compounds using amphiphilic cyclodextrin-coated polypropylene.

    Science.gov (United States)

    Lumholdt, Ludmilla; Fourmentin, Sophie; Nielsen, Thorbjørn T; Larsen, Kim L

    2014-01-01

    Polypropylene nonwovens were functionalised using a self-assembled, amphiphilic cyclodextrin coating and the potential for water purification by removal of pollutants was studied. As benzene is one of the problematic compounds in the Water Framework Directive, six volatile organic compounds (benzene and five benzene-based substances) were chosen as model compounds. The compounds were tested as a mixture in order to provide a more realistic situation since the wastewater will be a complex mixture containing multiple pollutants. The volatile organic compounds are known to form stable inclusion complexes with cyclodextrins. Six different amphiphilic cyclodextrin derivatives were synthesised in order to elucidate whether or not the uptake abilities of the coating depend on the structure of the derivative. Headspace gas chromatography was used for quantification of the uptake exploiting the volatile nature of benzene and its derivatives. The capacity was shown to increase beyond the expected stoichiometries of guest-host complexes with ratios of up to 16:1.

  2. Expanding the modular ester fermentative pathways for combinatorial biosynthesis of esters from volatile organic acids.

    Science.gov (United States)

    Layton, Donovan S; Trinh, Cong T

    2016-08-01

    Volatile organic acids are byproducts of fermentative metabolism, for example, anaerobic digestion of lignocellulosic biomass or organic wastes, and are often times undesired inhibiting cell growth and reducing directed formation of the desired products. Here, we devised a general framework for upgrading these volatile organic acids to high-value esters that can be used as flavors, fragrances, solvents, and biofuels. This framework employs the acid-to-ester modules, consisting of an AAT (alcohol acyltransferase) plus ACT (acyl CoA transferase) submodule and an alcohol submodule, for co-fermentation of sugars and organic acids to acyl CoAs and alcohols to form a combinatorial library of esters. By assembling these modules with the engineered Escherichia coli modular chassis cell, we developed microbial manufacturing platforms to perform the following functions: (i) rapid in vivo screening of novel AATs for their catalytic activities; (ii) expanding combinatorial biosynthesis of unique fermentative esters; and (iii) upgrading volatile organic acids to esters using single or mixed cell cultures. To demonstrate this framework, we screened for a set of five unique and divergent AATs from multiple species, and were able to determine their novel activities as well as produce a library of 12 out of the 13 expected esters from co-fermentation of sugars and (C2-C6) volatile organic acids. We envision the developed framework to be valuable for in vivo characterization of a repertoire of not-well-characterized natural AATs, expanding the combinatorial biosynthesis of fermentative esters, and upgrading volatile organic acids to high-value esters. Biotechnol. Bioeng. 2016;113: 1764-1776. © 2016 Wiley Periodicals, Inc.

  3. Assessing the fate of biodegradable volatile organic contaminants in unsaturated soil filter systems

    Science.gov (United States)

    Thullner, Martin; de Biase, Cecilia; Hanzel, Joanna; Reger, Daniel; Wick, Lukas; Oswald, Sascha; van Afferden, Manfred; Schmidt, Axel; Reiche, Nils; Jechalke, Sven

    2010-05-01

    The assessment of contaminant biodegradation in the subsurface is challenged by various abiotic processes leading to a reduction of contaminant concentration without a destructive mass removal of the contaminant. In unsaturated porous media, this interplay of processes is further complicated by volatilization. Many organic contaminants are sufficiently volatile to allow for significant fluxes from the water phase into the soil air, which can eventually lead to an emission of contaminants into the atmosphere. Knowledge of the magnitude of these emissions is thus required to evaluate the efficiency of bioremediation in such porous media and to estimate potential risks due to these emissions. In the present study, vertical flow constructed wetlands were investigated at the pilot scale as part of the SAFIRA II project. The investigated wetland system is intermittently irrigated by contaminated groundwater containing the volatile compounds benzene and MTBE. Measured concentration at the in- and outflow of the system demonstrate a high mass removal rate, but the highly transient flow and transport processes in the system challenge the quantification of biodegradation and volatilization and their contribution to the observed mass removal. By a combination of conservative solute tracer tests, stable isotope fractionation and measurements of natural radon concentration is the treated groundwater is was possible to determine the contribution of biodegradation and volatilization to total mass removal. The results suggest that for the investigated volatile compounds biodegradation is the dominating mass removal process with volatilization contributing only to minor or negligible amounts. These results can be confirmed by reactive transport simulations and were further supported by laboratory studies showing that also gas phase gradients of volatile compounds can be affected by biodegradation suggesting the unsaturated zone to act as a biofilter for contaminants in the soil air.

  4. Transformations of particles, metal elements and natural organic matter in different water treatment processes

    Institute of Scientific and Technical Information of China (English)

    YAN Ming-quan; WANG Dong-sheng; SHI Bao-you; WEI Qun-shan; QU Jiu-hui; TANG Hong-xiao

    2007-01-01

    Characterizing namral organic matter(NOM),particles and elements in different water treatment processes Can give a useful information to optimize water treatment operations.In this article,transformations of particles,metal elements and NOM in a pilot-scale water treatment plant were investigated by laser light granularity system,particle counter,glass-fiber membrane filtration,inductively coupled plasma-optical emission spectroscopy,ultra filtration and resin absorbents fractionation.The results showed that particles,NOM and trihalomethane formation precursors were removed synergistically by sequential treamaent of different processes. Preozonation markedly changed the polarity and molecular weight of NOM.and it could be conducive to the following coagulation processthrough destabilizing particles and colloids;mid-ozonation enhanced the subsequent granular activated carbon(GAC)filtration process by decreasing molecular weight of organic matters.Coagulation-flotation and GAC were more efficient in removing fixed suspended solids and larger particles;while sand-filtration was more effcient in removing volatile suspended solids and smaller particles.Flotation performed better than sedimentation in terms of particle and NOM removal.The type of coagulant could greatly affect the performance of coagulation-flotation.Pre-hydrolyzed composite coagulant(HPAC)was superior to FeCl3 concerning the removals of hydrophobic dissolved organic carbon and volatile suspended solids.The leakages of flocs from sand-filtration and microorganisms from GAC should be mitigated to ensure the reliability of the whole treatment system.

  5. 40 CFR 60.502 - Standard for Volatile Organic Compound (VOC) emissions from bulk gasoline terminals.

    Science.gov (United States)

    2010-07-01

    ... (VOC) emissions from bulk gasoline terminals. 60.502 Section 60.502 Protection of Environment... SOURCES Standards of Performance for Bulk Gasoline Terminals § 60.502 Standard for Volatile Organic Compound (VOC) emissions from bulk gasoline terminals. On and after the date on which § 60.8(a) requires a...

  6. ECOS E-MATRIX Methane and Volatile Organic Carbon (VOC) Emissions Best Practices Database

    Energy Technology Data Exchange (ETDEWEB)

    Parisien, Lia [The Environmental Council Of The States, Washington, DC (United States)

    2016-01-31

    This final scientific/technical report on the ECOS e-MATRIX Methane and Volatile Organic Carbon (VOC) Emissions Best Practices Database provides a disclaimer and acknowledgement, table of contents, executive summary, description of project activities, and briefing/technical presentation link.

  7. Electrospun Polyurethane Fibers for Absorption of Volatile Organic Compounds from Air

    NARCIS (Netherlands)

    Scholten, E.; Bromberg, L.; Rutledge, G.C.; Hatton, T.A.

    2011-01-01

    Electrospun polyurethane fibers for removal of volatile organic compounds (VOC) from air with rapid VOC absorption and desorption have been developed. Polyurethanes based on 4,4-methylenebis(phenylisocyanate) (MDI) and aliphatic isophorone diisocyanate as the hard segments and butanediol and

  8. SCREENING PROCESSED MILK FOR VOLATILE ORGANIC COMPOUNDS USING VACUUM DISTILLATION/GAS CHROMATOGRAPHY/MASS SPECTROMETRY

    Science.gov (United States)

    An adaptation of Office of Solid Waste and Emergency Response' Test Methods for Evaluating Solid Waste Physical/Chemical Methods (SW-846) method 8261 to analyze milk for an expanded list of volatile organic compounds is presented. The milk matriz exhibits a strong affinity for o...

  9. Modeling emissions of volatile organic compounds from silage storages and feed lanes

    Science.gov (United States)

    An initial volatile organic compound (VOC) emission model for silage sources, developed using experimental data from previous studies, was incorporated into the Integrated Farm System Model (IFSM), a whole-farm simulation model used to assess the performance, environmental impacts, and economics of ...

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

    Science.gov (United States)

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

  11. Emission of volatile organic compounds after land application of cattle manure

    Science.gov (United States)

    Beef cattle manure can serve as a valuable source of nutrients for crop production. However, emissions of volatile organic compounds (VOCs) following land application may pose an odor nuisance to downwind populations. This study was conducted to evaluate the effects of application method, diet, so...

  12. WORKSHOP REPORT - CONSIDERATIONS FOR DEVELOPING LEACHING TEST METHODS FOR SEMI- AND NON-VOLATILE ORGANIC COMPOUNDS

    Science.gov (United States)

    The report provides a summary of the information exchange at a workshop on the potential for release of semi- or non-volatile organic constituents at contaminated sites where sub-surface treatment has been used to control migration, and from waste that is disposed or re-used. The...

  13. Emission of volatile organic compounds as affected by rate of application of cattle manure

    Science.gov (United States)

    Beef cattle manure can serve as a valuable nutrient source for crop production. However, emissions of volatile organic compounds (VOCs) following land application may pose a potential off-site odor concern. This study was conducted to evaluate the effects of land application method, N- application...

  14. Can ornamental potted plants remove volatile organic compounds from indoor air? - a review

    DEFF Research Database (Denmark)

    Dela Cruz, Majbrit; Christensen, Jan H.; Thomsen, Jane Dyrhauge;

    2014-01-01

    Volatile organic compounds (VOCs) are found in indoor air, and many of these can affect human health (e.g. formaldehyde and benzene are carcinogenic). Plants affect the levels of VOCs in indoor environments, thus they represent a potential green solution for improving indoor air quality...

  15. MEASUREMENTS OF VOLATILE ORGANIC COMPOUNDS AND PARTICLES DURING APPLICATION OF LATEX PAINT WITH AN AIRLESS SPRAYER

    Science.gov (United States)

    The paper discusses experiments, conducted at EPA's Indoor Air Quality Research House, to measure airborne concentrations of volatile organic compounds (VOCs) and particles during and following the spray-application of latex wall paint. (NOTE: Paint may be applied indoors by a v...

  16. ISOTOPIC (14C) AND CHEMICAL COMPOSITION OF ATMOSPHERIC VOLATILE ORGANIC COMPOUND FRACTIONS - PRECURSORS TO OZONE FORMATION

    Science.gov (United States)

    Atmospheric volatile organic compounds (VOCs) are an important factor in the production of ozone near ground level [3]. Many hydrocarbons originate from auto exhaust. However, a number of VOCs, e.g., isoprene, are known to be natural in origin. To develop reliable models for un...

  17. Electrospun Polyurethane Fibers for Absorption of Volatile Organic Compounds from Air

    NARCIS (Netherlands)

    Scholten, E.; Bromberg, L.; Rutledge, G.C.; Hatton, T.A.

    2011-01-01

    Electrospun polyurethane fibers for removal of volatile organic compounds (VOC) from air with rapid VOC absorption and desorption have been developed. Polyurethanes based on 4,4-methylenebis(phenylisocyanate) (MDI) and aliphatic isophorone diisocyanate as the hard segments and butanediol and tetrame

  18. 77 FR 14324 - National Volatile Organic Compound Emission Standards for Aerosol Coatings-Addition of Dimethyl...

    Science.gov (United States)

    2012-03-09

    .... Email: a-and-r-docket@epa.gov . Fax: (202) 566-9744. Mail: U.S. Postal Service, send comments to: EPA... Factors AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: The EPA is proposing to amend the National Volatile Organic Compound Emission Standards for Aerosol Coatings final rule...

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

    Science.gov (United States)

    Twenty common plant species were screened for emissions of biogenic volatile organic compounds (BVOCS) at a lowland tropical wet forest site in Costa Rica. Ten of the species. examined emitted substantial quantities of isoprene. These species accounted for 35-50% of the total bas...

  20. Removal of H2S and volatile organic sulfur compounds by silicone membrane extraction

    NARCIS (Netherlands)

    Manconi, I.; Lens, P.N.L.

    2009-01-01

    BACKGROUND: This study explores an alternative process for the abatement and/or desulfurization of H2S and volatile organic sulfur compounds (VOSC) containing waste streams, which employs a silicone-based membrane to simultaneously remove H2S and VOSC. An extractive membrane reactor allows the selec

  1. Cold Temperature and Biodiesel Fuel Effects on Speciated Emissions of Volatile Organic Compounds from Diesel Trucks

    Science.gov (United States)

    Speciated volatile organic compounds (VOCs) were measured in diesel exhaust from three medium heavy-duty trucks equipped with modern aftertreatment technologies. Emissions testing was conducted on a chassis dynamometer at two ambient temperatures (-6.7°C and 21.7°C) operating on ...

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

    NARCIS (Netherlands)

    Kesselmeier, J.; Ciccioli, P.; Kuhn, U.; Stefani, P.; Biesenthal, T.; Rottenberger, S.; Wolf, A.; Vitullo, M.; Valentini, R.; Nobre, A.; Kabat, P.; Andreae, M.O.

    2002-01-01

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

  3. Removal of volatile organic compounds in vertical flow filters: predictions from Reactive Transport Modeling

    NARCIS (Netherlands)

    De Biase, C.; Maier, U.; Baeder-Bederski, O.; Bayer, P.; Oswald, S.E.; Thullner, M.

    2011-01-01

    Vertical flow filters are containers filled with porous medium that are recharged from top and drained at the bottom, and are operated at partly saturated conditions. They have recently been suggested as treatment technology for groundwater containing volatile organic compounds (VOCs). Numerical rea

  4. Removal of volatile organic compounds in vertical flow filters: predictions from Reactive Transport Modeling

    NARCIS (Netherlands)

    De Biase, C.; Maier, U.; Baeder-Bederski, O.; Bayer, P.; Oswald, S.E.; Thullner, M.

    2011-01-01

    Vertical flow filters are containers filled with porous medium that are recharged from top and drained at the bottom, and are operated at partly saturated conditions. They have recently been suggested as treatment technology for groundwater containing volatile organic compounds (VOCs). Numerical rea

  5. Volatile Organic Compound Emissions from USAF Wastewater Treatment Plants in Ozone Nonattainment Areas

    Science.gov (United States)

    1994-09-01

    Levels," in Toxicity Reduction in Industrial Effluents. Editors P.W. Lankford and W.W. Eckenfelder , Jr. New York NY: Van Nostrand Reinhold, 1990. 50...Argaman, Yerachmiel. "Stripping of Volatile Organics," in Toxicity Reduction in Industrial Effluents. Editors P.W. Lankford and W.W. Eckenfelder , Jr New

  6. Treatment of volatile organic contaminants in a vertical flow filter: Relevance of different removal processes

    NARCIS (Netherlands)

    De Biase, C.; Reger, D.; Schmidt, A.; Jechalke, S.; Reiche, N.; Martínez-Lavanchy, P.M.; Rosell, M.; Van Afferden, M.; Maier, U.; Oswald, S.E.; Thullner, M.

    2011-01-01

    Vertical flow filters and vertical flow constructed wetlands are established wastewater treatment systems and have also been proposed for the treatment of contaminated groundwater. This study investigates the removal processes of volatile organic compounds in a pilot-scale vertical flow filter. The

  7. Development of the colorimetric sensor array for detection of explosives and volatile organic compounds in air

    DEFF Research Database (Denmark)

    Kostesha, Natalie; Alstrøm, Tommy Sonne; Johnsen, C

    2010-01-01

    In the framework of the research project 'Xsense' at the Technical University of Denmark (DTU) we are developing a simple colorimetric sensor array which can be useful in detection of explosives like DNT and TNT, and identification of volatile organic compounds in the presence of water vapor in air...

  8. SUPERCRITICAL FLUID EXTRACTION OF SEMI-VOLATILE ORGANIC COMPOUNDS FROM PARTICLES

    Science.gov (United States)

    A nitrogen oxide flux chamber was modified to measure the flux of semi-volatile organic compounds (SVOCs). Part of the modification involved the development of methods to extract SVOCs from polyurethane foam (PUF), sand, and soil. Breakthroughs and extraction efficiencies were ...

  9. FINAL REPORT: MEMBRANE-MEDIATED EXTRACTION AND BIODEGRADATION OF VOLATILE ORGANIC COMPOUNDS FROM AIR

    Science.gov (United States)

    The report describes feasibility tests of a two-step strategy for air pollution control applicable to exhaust air contaminated with volatile organic compounds (VOCs) from painting aircraft. In the first step, the VOC-contaminated air passes over coated, polypropylene, hollow-fibe...

  10. Detection of diseased plants by analysis of volatile organic compound emission

    NARCIS (Netherlands)

    Jansen, R.M.C.; Wildt, J.; Kappers, I.F.; Bouwmeester, H.J.; Hofstee, J.W.; Henten, van E.

    2011-01-01

    This review focuses on the detection of diseased plants by analysis of volatile organic compound (VOC) emissions. It includes an overview of studies that report on the impact of infectious and noninfectious diseases on these emissions and discusses the specificity of disease-induced emissions. The

  11. A POLYMER-CERAMIC COMPOSITE MEMBRANE FOR RECOVERING VOLATILE ORGANIC COMPOUNDS FROM WASTEWATERS BY PERVAPORATION

    Science.gov (United States)

    A composite membrane was constructed on a porous ceramic support from a block copolymer of styrene and butadiene (SBS). It was tested in a laboratory pervaporation apparatus for recovering volatile organic compounds (VOCs) such a 1,1,1-trichloroethane (TCA) and trichloroethylene ...

  12. OPTIMIZATION OF MULTICOMPONENT PERVAPORATION FOR REMOVAL OF VOLATILE ORGANIC COMPOUNDS FROM WATER

    Science.gov (United States)

    Optimal operation of a hollow fiber membrane module for pervaporative removal of multicomponent volatile organic compounds (VOCs) from wastewater was studied. A shell-and-tube heat-exchange type of hollow fiber module was considered for treatment of a wastewater containing toluen...

  13. Removal of volatile organic compounds in vertical flow filters: predictions from Reactive Transport Modeling

    NARCIS (Netherlands)

    De Biase, C.; Maier, U.; Baeder-Bederski, O.; Bayer, P.; Oswald, S.E.; Thullner, M.

    2011-01-01

    Vertical flow filters are containers filled with porous medium that are recharged from top and drained at the bottom, and are operated at partly saturated conditions. They have recently been suggested as treatment technology for groundwater containing volatile organic compounds (VOCs). Numerical

  14. Design and Analysis of SAW Based MEMS Gas Sensor for the Detection of Volatile Organic Gases

    Directory of Open Access Journals (Sweden)

    Staline Johnson

    2014-03-01

    Full Text Available This paper portrays the design and analysis of SAW based MEMS gas sensor for the detection of volatile organic gases. The gas sensor consists of interdigitated transducers modeled on a piezoelectric substrate and covered by a thin film of polyisobutylene (PIB which acts as the sensing layer. The piezoelectric substrate material used is YZ cut Lithium Niobate (LiNbO3 and electrodes used are made of Aluminium (Al. Mass loading effect on the sensing layer is used for the detection of volatile organic gases. The design and simultions were carried out by using comsol multiphysics software based on Finite Element Method (FEM for analytical simulations. The resonant frequency of the SAW device was determined and simulations are carried out by exposing the sensor to 100 ppm of various volatile organic gases and corresponding shift in resonant frequency for various gases are determined. The reduction in the resonant frequency is used for the detection of volatile organic gases such as chloromethane, dichloromethane, trichloromethane, tetrachloroethene, carbon tetrachloride and trichloroethylene.

  15. Detection of diseased plants by analysis of volatile organic compound emission

    NARCIS (Netherlands)

    Jansen, R.M.C.; Wildt, J.; Kappers, I.F.; Bouwmeester, H.J.; Hofstee, J.W.; Henten, van E.

    2011-01-01

    This review focuses on the detection of diseased plants by analysis of volatile organic compound (VOC) emissions. It includes an overview of studies that report on the impact of infectious and noninfectious diseases on these emissions and discusses the specificity of disease-induced emissions. The r

  16. Structure of phase-separated ferroelectric/ semiconducting polymer blends for organic non-volatile memories

    NARCIS (Netherlands)

    Mcneill, C.R.; Asadi, K.; Watts, B.; Blom, P.W.M.; Leeuw, D.M. de

    2010-01-01

    The phase-separated structure of blends of the ferroelectric polymer P(VDF-TrFE) and the semiconducting polymer P3HT used in organic non-volatile memories is revealed with soft X-ray spectromicroscopy. These thin-film blends show a columnar morphology, with P3HT-rich columns enclosed in a continuous

  17. Treatment of volatile organic contaminants in a vertical flow filter: Relevance of different removal processes

    NARCIS (Netherlands)

    De Biase, C.; Reger, D.; Schmidt, A.; Jechalke, S.; Reiche, N.; Martínez-Lavanchy, P.M.; Rosell, M.; Van Afferden, M.; Maier, U.; Oswald, S.E.; Thullner, M.

    2011-01-01

    Vertical flow filters and vertical flow constructed wetlands are established wastewater treatment systems and have also been proposed for the treatment of contaminated groundwater. This study investigates the removal processes of volatile organic compounds in a pilot-scale vertical flow filter.

  18. Analysis of selected volatile organic compounds at background level in South Africa.

    Science.gov (United States)

    Ntsasa, Napo; Tshilongo, James; Lekoto, Goitsemang

    2017-04-01

    Volatile organic compounds (VOC) are measured globally at urban air pollution monitoring and background level at specific locations such as the Cape Point station. The urban pollution monitoring is legislated at government level; however, the background levels are scientific outputs of the World Meteorological Organisation Global Atmospheric Watch program (WMO/GAW). The Cape Point is a key station in the Southern Hemisphere which monitors greenhouse gases and halocarbons, with reported for over the past decade. The Cape Point station does not have the measurement capability VOC's currently. A joint research between the Cape Point station and the National Metrology Institute of South Africa (NMISA) objective is to perform qualitative and quantitative analysis of volatile organic compounds listed in the GAW program. NMISA is responsible for development, maintain and disseminate primary reference gas mixtures which are directly traceable to the International System of Units (SI) The results of some volatile organic compounds which where sampled in high pressure gas cylinders will be presented. The analysis of samples was performed on the gas chromatography with flame ionisation detector and mass selective detector (GC-FID/MSD) with a dedicate cryogenic pre-concentrator system. Keywords: volatile organic compounds, gas chromatography, pre-concentrator

  19. INHIBITORY EFFECTS OF VOLATILE ORGANIC COMPOUNDS ON NEURONAL NICOTINIC ACETYLCHOLINE RECEPTORS.

    Science.gov (United States)

    INHIBITORY EFFECTS OF VOLATILE ORGANIC COMPOUNDS ON NEURONAL NICOTINIC ACETYLCHOLINE RECEPTORS. A.S. Bale*; P.J. Bushnell; C.A. Meacham; T.J. Shafer Neurotoxicology Division, NHEERL, ORD, US Environmental Protection Agency, Research Triangle Park, NC, USA Toluene (TOL...

  20. INHIBITION OF HUMAN A7 NEURONAL NICOTINIC ACETYLCHOLINE RECEPTORS BY THE VOLATILE ORGANIC SOLVENT TRICHLOROETHYLENE.

    Science.gov (United States)

    Volatile organic compounds such as toleune, trichloroethylene and perchloroethylene are potent and reversible blockers of voltage-gated calcium current in nerve growth factor (NGF)-differentiated pheochromocytoma (PC12) cells. It is hypothesized that effects of VOCs on ICa contri...

  1. Volatile organic compound emmission rates from mixed deciduous and coniferous foest in Northern Wisconsin, USA

    Science.gov (United States)

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

    1999-01-01

    Biogenic emissions of volatile organic compounds {VOC) from forests play an important role in regulating the atmospheric trace gas composition including global tropospheric ozone concentrations. However, more information is needed on VOC emission rates from different forest regions of the world to understand regional and global impacts and to implement possible...

  2. Carbon cycle: Ocean dissolved organics matter

    Science.gov (United States)

    Amon, Rainer M. W.

    2016-12-01

    Large quantities of organic carbon are stored in the ocean, but its biogeochemical behaviour is elusive. Size-age-composition relations now quantify the production of tiny organic molecules as a major pathway for carbon sequestration.

  3. Flexible non-volatile memory devices based on organic semiconductors

    Science.gov (United States)

    Cosseddu, Piero; Casula, Giulia; Lai, Stefano; Bonfiglio, Annalisa

    2015-09-01

    The possibility of developing fully organic electronic circuits is critically dependent on the ability to realize a full set of electronic functionalities based on organic devices. In order to complete the scene, a fundamental element is still missing, i.e. reliable data storage. Over the past few years, a considerable effort has been spent on the development and optimization of organic polymer based memory elements. Among several possible solutions, transistor-based memories and resistive switching-based memories are attracting a great interest in the scientific community. In this paper, a route for the fabrication of organic semiconductor-based memory devices with performances beyond the state of the art is reported. Both the families of organic memories will be considered. A flexible resistive memory based on a novel combination of materials is presented. In particular, high retention time in ambient conditions are reported. Complementary, a low voltage transistor-based memory is presented. Low voltage operation is allowed by an hybrid, nano-sized dielectric, which is also responsible for the memory effect in the device. Thanks to the possibility of reproducibly fabricating such device on ultra-thin substrates, high mechanical stability is reported.

  4. RECEPTOR MODEL COMPARISONS AND WIND DIRECTION ANALYSES OF VOLATILE ORGANIC COMPOUNDS AND SUBMICROMETER PARTICLES IN AN ARID, BINATIONAL, URBAN AIRSHED

    Science.gov (United States)

    The relationship between continuous measurements of volatile organic compounds sources and particle number was evaluated at a Photochemical Assessment Monitoring Station Network (PAMS) site located near the U.S.-Mexico Border in central El Paso, TX. Sources of volatile organic...

  5. Supramolecular Soft Matter Applications in Materials and Organic Electronics

    CERN Document Server

    Nakanishi, Takashi

    2011-01-01

    The pivotal text that bridges the gap between fundamentals and applications of soft matter in organic electronics Covering an expanding and highly coveted subject area, Supramolecular Soft Matter enlists the services of leading researchers to help readers understand and manipulate the electronic properties of supramolecular soft materials for use in organic opto-electronic devices, such as photovoltaics and field effect transistors, some of the most desired materials for energy conservation. Rather than offering a compilation of current trends in supramolecular soft matter, this book bridges

  6. Constraining the Volatility Distributions and Possible Diffusion Limitations of Secondary Organic Aerosols Using Laboratory Dilution Experiments

    Science.gov (United States)

    Ye, Q.; Robinson, E. S.; Mahfouz, N.; Sullivan, R. C.; Donahue, N. M.

    2016-12-01

    Secondary organic aerosols (SOA) dominate the mass of fine particles in the atmosphere. Their formation involves both oxidation of volatile organics from various sources that produce products with uncertain volatilities, and diffusion of these products into the condensed phase. Therefore, constraining volatility distribution and diffusion timescales of the constituents in SOA are important in predicting size, concentration and composition of SOA, as well as how these properties of SOA evolve in the atmosphere. In this work, we demonstrate how carefully designed laboratory isothermal dilution experiments in smog chambers can shed light into the volatility distribution and any diffusion barriers of common types of SOA over time scales relevant to atmospheric transport and diurnal cycling. We choose SOA made from mono-terpenes (alpha-pinene and limonene) and toluene to represent biogenic and anthropogenic SOA. We look into how moisture content can alter any evaporation behaviors of SOA by varying relative humidity during SOA generation and during dilution process. This provides insight into whether diffusion in the condensed phase is rate limiting in reaching gas/particle equilibrium of semi-volatile organic compounds. Our preliminary results show that SOA from alpha-pinene evaporates continuously over several hours of experiments, and there is no substantial discernible differences over wide ranges of the chamber humidity. SOA from toluene oxidation shows slower evaporation. We fit these experimental data using absorptive partitioning theory and a particle dynamic model to obtain volatility distributions and to predict particle size evolution. This in the end will help us to improve representation of SOA in large scale chemical transport models.

  7. Composition and reactivity of ferrihydrite-organic matter associations

    Science.gov (United States)

    Eusterhues, Karin; Hädrich, Anke; Neidhardt, Julia; Küsel, Kirsten; Totsche, Kai

    2014-05-01

    The formation of organo-mineral associations affects many soil forming processes. On the one hand, it will influence soil organic matter composition and development, because the complex organic matter mixtures usually fractionate during their association with mineral surfaces. Whereas the associated fraction is supposed to be stabilized, the non-associated fraction remains mobile and available to degradation by microorganisms. On the other hand, the organic coating will completely change the interface properties of Fe oxides such as solubility, charge and hydrophobicity. This in turn will strongly influence their reactivity towards nutrients and pollutants, the adsorption of new organic matter, and the availability of ferric Fe towards microorganisms. To better understand such processes we produced ferrihydrite-organic matter associations by adsorption and coprecipitation in laboratory experiments. As a surrogate for dissolved soil organic matter we used the water-extractable fraction of a Podzol forest-floor layer under spruce. Sorptive fractionation of the organic matter was investigated by 13C NMR and FTIR. Relative to the original forest-floor extract, the ferrihydrite-associated OM was enriched in polysaccharides but depleted in aliphatic C and carbonyl C, especially when adsorption took place. Liquid phase incubation experiments were carried out with an inoculum extracted from the podzol forest-floor under oxic conditions at pH 4.8 to quantify the mineralization of the adsorbed and coprecipitated organic matter. These experiments showed that the association with ferrihydrite stabilized the associated organic matter, but that differences in the degradability of adsorbed and coprecipitated organic matter were small. We therefore conclude that coprecipitation does not lead to a significant formation of microbial inaccessible organic matter domains. Microbial reduction experiments were performed using Geobacter bremensis. We observed that increasing amounts of

  8. Volatile Metabolites

    Directory of Open Access Journals (Sweden)

    Daryl D. Rowan

    2011-11-01

    Full Text Available Volatile organic compounds (volatiles comprise a chemically diverse class of low molecular weight organic compounds having an appreciable vapor pressure under ambient conditions. Volatiles produced by plants attract pollinators and seed dispersers, and provide defense against pests and pathogens. For insects, volatiles may act as pheromones directing social behavior or as cues for finding hosts or prey. For humans, volatiles are important as flavorants and as possible disease biomarkers. The marine environment is also a major source of halogenated and sulfur-containing volatiles which participate in the global cycling of these elements. While volatile analysis commonly measures a rather restricted set of analytes, the diverse and extreme physical properties of volatiles provide unique analytical challenges. Volatiles constitute only a small proportion of the total number of metabolites produced by living organisms, however, because of their roles as signaling molecules (semiochemicals both within and between organisms, accurately measuring and determining the roles of these compounds is crucial to an integrated understanding of living systems. This review summarizes recent developments in volatile research from a metabolomics perspective with a focus on the role of recent technical innovation in developing new areas of volatile research and expanding the range of ecological interactions which may be mediated by volatile organic metabolites.

  9. Natural organic matter properties in Swedish agricultural streams

    Science.gov (United States)

    Bieroza, Magdalena; Kyllmar, Katarina; Bergström, Lars; Köhler, Stephan

    2016-04-01

    We have analysed natural organic matter (NOM) properties in 18 agricultural streams in Sweden covering a broad range of environmental (climate, soil type), land use and water quality (nutrient and concentrations, pH, alkalinity) characteristics. Stream water samples collected every two weeks within an ongoing Swedish Monitoring Programme for Agriculture have been analysed for total/dissolved organic carbon, absorbance and fluorescence spectroscopy. A number of quantitative and qualitative spectroscopic parameters was calculated to help to distinguish between terrestrially-derived, refractory organic material and autochthonous, labile material indicative of biogeochemical transformations of terrestrial NOM and recent biological production. The study provides insights into organic matter properties and carbon budgets in agricultural streams and improves understanding of how agricultural catchments transform natural and anthropogenic fluxes of organic matter and nutrients to signals observed in receiving waters.

  10. Modeling organic matter stabilization during windrow composting of livestock effluents.

    Science.gov (United States)

    Oudart, D; Paul, E; Robin, P; Paillat, J M

    2012-01-01

    Composting is a complex bioprocess, requiring a lot of empirical experiments to optimize the process. A dynamical mathematical model for the biodegradation of the organic matter during the composting process has been developed. The initial organic matter expressed by chemical oxygen demand (COD) is decomposed into rapidly and slowly degraded compartments and an inert one. The biodegradable COD is hydrolysed and consumed by microorganisms and produces metabolic water and carbon dioxide. This model links a biochemical characterization of the organic matter by Van Soest fractionating with COD. The comparison of experimental and simulation results for carbon dioxide emission, dry matter and carbon content balance showed good correlation. The initial sizes of the biodegradable COD compartments are explained by the soluble, hemicellulose-like and lignin fraction. Their sizes influence the amplitude of the carbon dioxide emission peak. The initial biomass is a sensitive variable too, influencing the time at which the emission peak occurs.

  11. Advanced solid-state NMR spectroscopy of natural organic matter.

    Science.gov (United States)

    Mao, Jingdong; Cao, Xiaoyan; Olk, Dan C; Chu, Wenying; Schmidt-Rohr, Klaus

    2017-05-01

    Solid-state NMR is essential for the characterization of natural organic matter (NOM) and is gaining importance in geosciences and environmental sciences. This review is intended to highlight advanced solid-state NMR techniques, especially a systematic approach to NOM characterization, and their applications to the study of NOM. We discuss some basics of how to acquire high-quality and quantitative solid-state (13)C NMR spectra, and address some common technical mistakes that lead to unreliable spectra of NOM. The identification of specific functional groups in NOM, primarily based on (13)C spectral-editing techniques, is described and the theoretical background of some recently-developed spectral-editing techniques is provided. Applications of solid-state NMR to investigating nitrogen (N) in NOM are described, focusing on limitations of the widely used (15)N CP/MAS experiment and the potential of improved advanced NMR techniques for characterizing N forms in NOM. Then techniques used for identifying proximities, heterogeneities and domains are reviewed, and some examples provided. In addition, NMR techniques for studying segmental dynamics in NOM are reviewed. We also briefly discuss applications of solid-state NMR to NOM from various sources, including soil organic matter, aquatic organic matter, organic matter in atmospheric particulate matter, carbonaceous meteoritic organic matter, and fossil fuels. Finally, examples of NMR-based structural models and an outlook are provided. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Organic Matter in Space (IAU S251)

    Science.gov (United States)

    Kwok, Sun; Sanford, Scott

    2009-01-01

    Preface; From the local organising committee; Organising committee; Conference participants; Opening address of Symposium 251 C. Cesarsky; Session I. Observations of organic compounds beyond the Solar System William Irvine, Ewine van Dishoeck, Yvonne Pendleton and Hans Olofsson; Session II. Organic compounds within the Solar System Scott Sandford, Ernst Zinner and Dale Cruikshank; Session III. Laboratory analogues of organic compounds in space Max Bernstein and Thomas Henning; Banquet speech; Author index; Object index.

  13. Sensing of volatile organic compounds by copper phthalocyanine thin films

    Science.gov (United States)

    Ridhi, R.; Saini, G. S. S.; Tripathi, S. K.

    2017-02-01

    Thin films of copper phthalocyanine have been deposited by thermal evaporation technique. We have subsequently exposed these films to the vapours of methanol, ethanol and propanol. Optical absorption, infrared spectra and electrical conductivities of these films before and after exposure to chemical vapours have been recorded in order to study their sensing mechanisms towards organic vapours. These films exhibit maximum sensing response to methanol while low sensitivities of the films towards ethanol and propanol have been observed. The changes in sensitivities have been correlated with presence of carbon groups in the chemical vapours. The effect of different types of electrodes on response-recovery times of the thin film with organic vapours has been studied and compared. The electrodes gap distance affects the sensitivity as well as response-recovery time values of the thin films.

  14. ORGANIC VOLATILE IMPURITIES AND THEIR REGULATORY LIMITS: A PHARMACEUTICL PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    VIVEK CHAVDA

    2013-01-01

    Full Text Available Impurities in drug substances and drug products have been important regulatory issues in the Office of Generic Drugs by having significant impact on the approvability of Abbreviated New Drug Application (ANDAs. Organic solvents are commonly used in the pharmaceutical industry as reaction media, in separation and purification of synthesis products and also for cleaning of equipments. As residual solvents are not desirable substances in a final product, different methods for their removal may be used, provided they fulfill safety criteria. After the drying process, analysis need to be performed to check if amounts of solvents used at any step of the production do not exceed acceptable limits (taken from ICH Guideline or from pharmacopoeias. Also new solvents like supercritical fluids or ionic liquids are developed to replace traditional organic solvents in the pharmaceutical production processes. This review was grafted to provide information regarding OVI and/or residual solvent.

  15. A luminescent mixed-lanthanide-organic framework sensor for decoding different volatile organic molecules.

    Science.gov (United States)

    Zhan, Chao; Ou, Sha; Zou, Chao; Zhao, Min; Wu, Chuan-De

    2014-07-01

    A flexible tripodal polyaromatic acid (4,4',4″-(((2,4,6-trimethylbenzene-1,3,5-triyl)-tris(methylene))-tris(oxy))tribenzoic acid, H3TCM) was used to adapt the coordination sites of lanthanide ions for the construction of microporous lanthanide-organic frameworks (LOFs) [LnTCM(H2O)2]·3DMF·H2O (Ln-TCM; Ln = La, Eu, and/or Tb). In these LOFs, the emission band of TCM matches well with the excitation energy of lanthanide ions (Eu(3+) and Tb(3+)) which results in high-efficient resonance energy transfer from TCM to lanthanide ions. Moreover, the mixed EuxTb1-x-TCM has tunable pores to adapt different induced-fit-type host-guest interactions which can modulate both the energy transfer efficiency from TCM to Ln(3+) ions and the energy allocation between Eu(3+) and Tb(3+) ions in the luminescence spectra. We demonstrate that the Eu(x)Tb(1-x)-TCM sensor has the capability of decoding different volatile organic molecules (VOMs) with a clearly differentiable and unique emission intensity ratio of (5)D0 → (7)F2 (Eu(3+), 614 nm) to (5)D4 → (7)F5 (Tb(3+), 545 nm) transitions for every different VOM. Compared with the traditional absolute emission intensity method, such a self-referencing emission intensity strategy has generated self-calibrating, highly differentiable, and very stable luminescent signals for decoding different VOMs from the unique Eu(x)Tb(1-x)-TCM platform, which has great potential for practical applications.

  16. The prey's scent - Volatile organic compound mediated interactions between soil bacteria and their protist predators.

    Science.gov (United States)

    Schulz-Bohm, Kristin; Geisen, Stefan; Wubs, E R Jasper; Song, Chunxu; de Boer, Wietse; Garbeva, Paolina

    2017-03-01

    Protists are major predators of bacteria in soils. However, it remains unknown how protists sense their prey in this highly complex environment. Here, we investigated whether volatile organic compounds (VOCs) of six phylogenetic distinct soil bacteria affect the performance of three different soil protists and how that relates to direct feeding interactions. We observed that most bacteria affected protist activity by VOCs. However, the response of protists to the VOCs was strongly dependent on both the bacterial and protist interacting partner. Stimulation of protist activity by volatiles and in direct trophic interaction assays often coincided, suggesting that VOCs serve as signals for protists to sense suitable prey. Furthermore, bacterial terpene synthase mutants lost the ability to affect protists, indicating that terpenes represent key components of VOC-mediated communication. Overall, we demonstrate that volatiles are directly involved in protist-bacterial predator-prey interactions.

  17. Attraction of the gypsy moth to volatile organic compounds (VOCs) of damaged Dahurian larch.

    Science.gov (United States)

    Li, Jing; Valimaki, Sanna; Shi, Juan; Zong, Shixiang; Luo, Youqing; Heliovaara, Kari

    2012-01-01

    Olfactory responses of the gypsy moth Lymantria dispar (L.) (Lepidoptera: Lymantriidae), a major defoliator of deciduous trees, were examined in Inner Mongolia, China. We studied whether the gypsy moth adults are attracted by the major volatile organic compounds (VOCs) of damaged Larix gmelinii (Dahurian larch) foliage and compared the attractiveness of the plant volatiles with that of the synthetic sex pheromone. Our results indicated that the VOCs of the Dahurian larch were effective in attracting gypsy moth males especially during the peak flight period. The VOCs also attracted moths significantly better than the sex pheromone of the moth. Our study is the first trial to show the responses of adult gypsy moths to volatile compounds emitted from a host plant. Electroantennogram responses of L. gmelinii volatiles on gypsy moths supported our field observations. A synergistic effect between host plant volatiles and sex pheromone was also obvious, and both can be jointly applied as a new attractant method or population management strategy of the gypsy moth.

  18. Characterisation of volatile organic compounds in stemwood using solid-phase microextraction.

    Science.gov (United States)

    Wajs, A; Pranovich, A; Reunanen, M; Willför, S; Holmbom, B

    2006-01-01

    Solid-phase microextraction (SPME), hydrodistillation and dynamic headspace combined with GC and GC-MS were applied and compared for the analysis of volatile organic compounds (VOCs) from coniferous wood. The SPME conditions (type of fibre, size of wood sample, temperature and exposure time) were optimised, and more than 100 VOCs and semi-volatile compounds extracted and identified from the sapwood and heartwood of Norway spruce (Picea abies). The total number of mono- and sesquiterpenes eluted and identified was similar for the SPME and hydrodistillation methods, but more semi-volatile compounds were released by hydrodistillation. By applying dynamic headspace at room temperature, it was possible to analyse only the most volatile compounds. The qualitative composition of VOCs was similar in spruce sapwood and heartwood, although Z-beta-ocimene occurred only in sapwood while fenchol was present only in heartwood. SPME sampling coupled with GC, applied here to the analysis of VOCs released from stemwood of firs for the first time, is a convenient, sensitive, fast, solvent-free and simple method for the determination of wood volatiles. The technique requires much smaller sample amounts compared with hydrodistillation, and the total amount of VOCs extracted and identified is higher than that obtained by hydrodistillation or dynamic headspace. The relative ratios of the main mono- and sesquiterpenes and -terpenoids were similar using the SPME-GC and hydrodistillation methods.

  19. Emission of volatile organic compounds and production of secondary organic aerosol from stir-frying spices.

    Science.gov (United States)

    Liu, Tengyu; Liu, Qianyun; Li, Zijun; Huo, Lei; Chan, ManNin; Li, Xue; Zhou, Zhen; Chan, Chak K

    2017-12-01

    Cooking is an important source of volatile organic compounds (VOCs) and a potential source of secondary organic aerosol (SOA) both indoors and outdoors. In this study, VOC emissions from heating corn oil and stir-frying spices (i.e. garlic, ginger, myrcia and zanthoxylum piperitum (Sichuan pepper)) were characterized using an on-line membrane inlet vacuum ultraviolet single-photon ionization time-of-flight mass spectrometer (VUV-SPI-TOFMS). VOC emissions from heating corn oil were dominated by aldehydes, which were enhanced by factors of one order of magnitude when stir-frying spices. Stir-frying any of the spices studied generated large amounts of methylpyrrole (m/z 81). In addition, stir-frying garlic produced abundant dihydrohydroxymaltol (m/z 144) and diallyldisulfide (DADS) (m/z 146), while stir-frying ginger, myrcia and zanthoxylum piperitum produced abundant monoterpenes (m/z 136) and terpenoids (m/z 152, 154). SOA formed from emissions of stir-frying spices through reactions with excess ozone in a flow reactor as well as primary organic aerosol (POA) emissions were characterized using a scanning mobility particle sizer (SMPS) and a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS). Stir-frying garlic and ginger generated similar POA concentrations to those from heating corn oil while stir-frying myrcia and zanthoxylum piperitum generated double the amount of emissions. No SOA was observed from stir-frying garlic and ginger. The rates of SOA production from stir-frying myrcia and zanthoxylum piperitum were 1.8μgmin(-1)gspice(-1) and 8.7μgmin(-1)gspice(-1), equivalent to 13.4% and 53.1% of their own POA emission rates, respectively. Therefore, the contribution of stir-frying spices to ambient organic aerosol levels is likely dominated by POA. The rates of total terpene emission from stir-frying myrcia and zanthoxylum piperitum were estimated to be 5.1μgmin(-1)gspice(-1) and 24.9μgmin(-1)gspice(-1), respectively. Our results suggest

  20. Scalable printed electronics: an organic decoder addressing ferroelectric non-volatile memory

    Science.gov (United States)

    Ng, Tse Nga; Schwartz, David E.; Lavery, Leah L.; Whiting, Gregory L.; Russo, Beverly; Krusor, Brent; Veres, Janos; Bröms, Per; Herlogsson, Lars; Alam, Naveed; Hagel, Olle; Nilsson, Jakob; Karlsson, Christer

    2012-08-01

    Scalable circuits of organic logic and memory are realized using all-additive printing processes. A 3-bit organic complementary decoder is fabricated and used to read and write non-volatile, rewritable ferroelectric memory. The decoder-memory array is patterned by inkjet and gravure printing on flexible plastics. Simulation models for the organic transistors are developed, enabling circuit designs tolerant of the variations in printed devices. We explain the key design rules in fabrication of complex printed circuits and elucidate the performance requirements of materials and devices for reliable organic digital logic.

  1. Scalable printed electronics: an organic decoder addressing ferroelectric non-volatile memory

    Science.gov (United States)

    Ng, Tse Nga; Schwartz, David E.; Lavery, Leah L.; Whiting, Gregory L.; Russo, Beverly; Krusor, Brent; Veres, Janos; Bröms, Per; Herlogsson, Lars; Alam, Naveed; Hagel, Olle; Nilsson, Jakob; Karlsson, Christer

    2012-01-01

    Scalable circuits of organic logic and memory are realized using all-additive printing processes. A 3-bit organic complementary decoder is fabricated and used to read and write non-volatile, rewritable ferroelectric memory. The decoder-memory array is patterned by inkjet and gravure printing on flexible plastics. Simulation models for the organic transistors are developed, enabling circuit designs tolerant of the variations in printed devices. We explain the key design rules in fabrication of complex printed circuits and elucidate the performance requirements of materials and devices for reliable organic digital logic. PMID:22900143

  2. Scalable printed electronics: an organic decoder addressing ferroelectric non-volatile memory.

    Science.gov (United States)

    Ng, Tse Nga; Schwartz, David E; Lavery, Leah L; Whiting, Gregory L; Russo, Beverly; Krusor, Brent; Veres, Janos; Bröms, Per; Herlogsson, Lars; Alam, Naveed; Hagel, Olle; Nilsson, Jakob; Karlsson, Christer

    2012-01-01

    Scalable circuits of organic logic and memory are realized using all-additive printing processes. A 3-bit organic complementary decoder is fabricated and used to read and write non-volatile, rewritable ferroelectric memory. The decoder-memory array is patterned by inkjet and gravure printing on flexible plastics. Simulation models for the organic transistors are developed, enabling circuit designs tolerant of the variations in printed devices. We explain the key design rules in fabrication of complex printed circuits and elucidate the performance requirements of materials and devices for reliable organic digital logic.

  3. Remove volatile organic compounds (VOCs) with membrane separation techniques

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Membrane separation, a new technology for removing VOCs including pervaporation, vapor permeation, membrane contactor, and membrane bioreactor was presented. Comparing with traditional techniques, these special techniques are an efficient and energy-saving technology. Vapor permeation can be applied to recovery of organic solvents from exhaust streams. Membrane contactor could be used for removing or recovering VOCs from air or wastewater. Pervaporation and vapor permeation are viable methods for removing VOCs from wastewater to yield a VOC concentrate which could either be destroyed by conventional means, or be recycled for reuse.

  4. Microbial bioavailability regulates organic matter preservation in marine sediments

    NARCIS (Netherlands)

    Koho, K.A.; Nierop, K.G.J.; Moodley, L.; Middelburg, J.J.; Pozzato, L.; Soetaert, K.; van der Plicht, J.; Reichart, G.J.

    2013-01-01

    Burial of organic matter (OM) plays an important role in marine sediments, linking the short-term, biological carbon cycle with the long-term, geological subsurface cycle. It is well established that low-oxygen conditions promote organic carbon burial in marine sediments. However, the mechanism

  5. Organic Matter Application Can Reduce Copper Toxicity in Tomato Plants

    Science.gov (United States)

    Campbell, Brian

    2010-01-01

    Copper fungicides and bactericides are often used in tomato cultivation and can cause toxic Cu levels in soils. In order to combat this, organic matter can be applied to induce chelation reactions and form a soluble complex by which much of the Cu can leach out of the soil profile or be taken up safely by plants. Organic acids such as citric,…

  6. Organic Matter Application Can Reduce Copper Toxicity in Tomato Plants

    Science.gov (United States)

    Campbell, Brian

    2010-01-01

    Copper fungicides and bactericides are often used in tomato cultivation and can cause toxic Cu levels in soils. In order to combat this, organic matter can be applied to induce chelation reactions and form a soluble complex by which much of the Cu can leach out of the soil profile or be taken up safely by plants. Organic acids such as citric,…

  7. Organic Matter of the Mulhouse Basin, France: A synthesis

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Hofmann, P.; Huc, A.Y.; Carpentier, B.; Schaeffer, P.; Albrecht, P.; Keely, B.J.; Maxwell, J.R.; Leeuw, J.W. de; Leythaeuser, D.

    1993-01-01

    The lower Oligocene evaporite sequence of the Mulhouse Basin (France) contains organic matter-rich marl deposits. These marls display an overall cyclic variation of sedimentation rate, organic carbon content, hydrogen index and selected molecular parameters over a 30 m thick stratigraphic interval.

  8. Bacterial utilization of size-fractionated dissolved organic matter

    Digital Repository Service at National Institute of Oceanography (India)

    Khodse, V.B.; Bhosle, N.B.

    Dissolved organic matter (DOM) is an important source of organic carbon for sustaining the growth of heterotrophic bacteria. The bacterial utilization of high-molecular-weight (HMW; greater than 30 kDa to 0.22 mu m) and low-molecular-weight (LMW...

  9. Organic Aerosol Volatility Parameterizations and Their Impact on Atmospheric Composition and Climate

    Science.gov (United States)

    Tsigaridis, Konsta; Bauer, Susanne E.

    2015-01-01

    Despite their importance and ubiquity in the atmosphere, organic aerosols are still very poorly parameterized in global models. This can be explained by two reasons: first, a very large number of unconstrained parameters are involved in accurate parameterizations, and second, a detailed description of semi-volatile organics is computationally very expensive. Even organic aerosol properties that are known to play a major role in the atmosphere, namely volatility and aging, are poorly resolved in global models, if at all. Studies with different models and different parameterizations have not been conclusive on whether the additional complexity improves model simulations, but the added diversity of the different host models used adds an unnecessary degree of variability in the evaluation of results that obscures solid conclusions.

  10. Organic matter degradation in Lake Baikal - a sediment trap study

    DEFF Research Database (Denmark)

    Schubert, Carsten J.; Niggemann, Jutta; Lomstein, Bente Aagaard

    Lake Baikal offers a unique opportunity to study water column processes in a freshwater system with conditions similar to oceanic systems, e. g. great water depth and oxygenated water column. Investigations on sediment trap material provide information on the early stages of organic matter...... and composition of amino acids and fatty acids. The extent of organic matter degradation in the water column of Lake Baikal is reflected in the fluxes of total organic carbon, chlorins, amino acids, and fatty acids at different water depths. In line with earlier studies in marine systems, the labile compounds......, and the Fatty Acid Index [2]. All indicators showed consistent trends, indicating that the diagenetic stage of the sediment trap material increased with increasing water depth. This study of sediment trap material from Lake Baikal provided interesting insights in organic matter degradation in this unique...

  11. Validation of thermodesorption method for analysis of semi-volatile organic compounds adsorbed on wafer surface.

    Science.gov (United States)

    Hayeck, Nathalie; Gligorovski, Sasho; Poulet, Irène; Wortham, Henri

    2014-05-01

    To prevent the degradation of the device characteristics it is important to detect the organic contaminants adsorbed on the wafers. In this respect, a reliable qualitative and quantitative analytical method for analysis of semi-volatile organic compounds which can adsorb on wafer surfaces is of paramount importance. Here, we present a new analytical method based on Wafer Outgassing System (WOS) coupled to Automated Thermal Desorber-Gas chromatography-Mass spectrometry (ATD-GC-MS) to identify and quantify volatile and semi-volatile organic compounds from 6", 8" and 12" wafers. WOS technique allows the desorption of organic compounds from one side of the wafers. This method was tested on three important airborne contaminants in cleanroom i.e. tris-(2-chloroethyl) phosphate (TCEP), tris-(2-chloroisopropyl) phosphate (TCPP) and diethyl phthalate (DEP). In addition, we validated this method for the analysis and quantification of DEP, TCEP and TCPP and we estimated the backside organic contamination which may contribute to the front side of the contaminated wafers. We are demonstrating that WOS/ATD-GC-MS is a suitable and highly efficient technique for desorption and quantitative analysis of organophosphorous compounds and phthalate ester which could be found on the wafer surface.

  12. Overview of one transistor type of hybrid organic ferroelectric non-volatile memory

    Institute of Scientific and Technical Information of China (English)

    Young; Tea; Chun; Daping; Chu

    2015-01-01

    Organic ferroelectric memory devices based on field effect transistors that can be configured between two stable states of on and off have been widely researched as the next generation data storage media in recent years.This emerging type of memory devices can lead to a new instrument system as a potential alternative to previous non-volatile memory building blocks in future processing units because of their numerous merits such as cost-effective process,simple structure and freedom in substrate choices.This bi-stable non-volatile memory device of information storage has been investigated using several organic or inorganic semiconductors with organic ferroelectric polymer materials.Recent progresses in this ferroelectric memory field,hybrid system have attracted a lot of attention due to their excellent device performance in comparison with that of all organic systems.In this paper,a general review of this type of ferroelectric non-volatile memory is provided,which include the device structure,organic ferroelectric materials,electrical characteristics and working principles.We also present some snapshots of our previous study on hybrid ferroelectric memories including our recent work based on zinc oxide nanowire channels.

  13. Distribution of volatile organic compounds in Madrid (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Pastor, R.M.; Garcia-Alonso, S.; Quejido Cabezas, A.J. [CIEMAT, Madrid (Spain)

    1999-07-01

    From November 1995 to October 1996, airborne concentrations of VOCs were measured in the Madrid area to study the organic pollution in general, and the correlation between different pollutants in relation to such parameters as location and season. Mean concentrations for up to 90 compounds were measured at four test sites, including both urban and suburban areas. At the urban sites, maximum concentrations occurred in the autumn and winter, whereas minimum concentrations were reached in summer and spring. Similar changes were obtained for the less-contaminated site located in the SE of the city, whereas a different pattern was found at the site in the NW of the city due to meteorological aspects. Mean levels of hydrocarbons in Madrid were quite similar to those found in other European cities. Chemometrical techniques were applied to the set of data in order to assess the influence of such factors as traffic, temperature and seasonal variations on the VOC levels. (orig.)

  14. The effect of natural organic matter on bioaccumulation and toxicity of chlorobenzenes to green algae.

    Science.gov (United States)

    Zhang, Shuai; Lin, Daohui; Wu, Fengchang

    2016-07-05

    The effect of natural organic matter (NOM) on toxicity and bioavailability of hydrophobic organic contaminants (HOCs) to aquatic organisms has been investigated with conflicting results and undefined mechanisms, and few studies have been conducted on volatile HOCs. In this study, six volatile chlorobenzenes (CBs) with 1-6 chlorine substitutions were investigated for their bioaccumulation in an acute toxicity to a green alga (Chlorella pyrenoidosa) in the presence/absence of Suwannee River NOM (SRNOM). The fluorescence quenching efficiency of SRNOM increased as the number of chlorine substitutions of CBs increased. SRNOM increased the cell-surface hydrophobicity of algae and decreased the release rates of algae-accumulated CBs, thus increasing the concentration factor (CF) and accumulation of the CBs in the algae. SRNOM increased the toxicity of monochlorobenzene and 1,2-dichlorobenzene, decreased the toxicity of pentachlorobenzene and hexachlorobenzene, and had no significant effect on the toxicity of 1,2,3-trichlorobenzene and 1,2,3,4-tetrachlorobenzene. Relationships between the 96 h CF/IC50 (i.e., the CB concentration leading to a 50% algal growth reduction compared with the control) and physicochemical properties of CBs with/without SRNOM were established, providing reasonable explanations for the experimental results. These findings will help with the accurate assessment of ecological risks of organic pollutants in the presence of NOM.

  15. Model studies of volatile diesel exhaust particle formation: organic vapours involved in nucleation and growth?

    Science.gov (United States)

    Pirjola, L.; Karl, M.; Rönkkö, T.; Arnold, F.

    2015-02-01

    High concentration of volatile nucleation mode particles (NUP) formed in the atmosphere during exhaust cools and dilutes have hazardous health effects and impair visibility in urban areas. Nucleation mechanisms in diesel exhaust are only poorly understood. We performed model studies using two sectional aerosol dynamics process models AEROFOR and MAFOR on the formation of particles in the exhaust of a diesel engine, equipped with an oxidative after-treatment system and running with low fuel sulphur content (FSC), under laboratory sampling conditions where the dilution system mimics real-world conditions. Different nucleation mechanisms were tested; based on the measured gaseous sulphuric acid (GSA) and non-volatile core and soot particle number concentrations of the raw exhaust, the model simulations showed that the best agreement between model predictions and measurements in terms of particle number size distribution was obtained by barrierless heteromolecular homogeneous nucleation between GSA and semi-volatile organic vapour (for example adipic acid) combined with the homogeneous nucleation of GSA alone. Major growth of the particles was predicted to occur by the same organic vapour at concentrations of (1-2) ×1012cm-3. The pre-existing core and soot mode concentrations had opposite trend on the NUP formation, and maximum NUP formation was predicted if a diesel particle filter (DPF) was used. On the other hand, NUP formation was ceased if the GSA concentration was less than 1010cm-3 which suggests, based on the measurements, the usage of biofuel to prevent volatile particles in diesel exhaust.

  16. Analysis of organic volatile flavor compounds in fermented stinky tofu using SPME with different fiber coatings.

    Science.gov (United States)

    Liu, Yuping; Miao, Zhiwei; Guan, Wei; Sun, Baoguo

    2012-03-26

    The organic volatile flavor compounds in fermented stinky tofu (FST) were studied using SPME-GC/MS. A total of 39 volatile compounds were identified, including nine esters, seven alcohols, five alkenes, four sulfides, three heterocycles, three carboxylic acids, three ketones, two aldehydes, one phenol, one amine and one ether. These compounds were determined by MS, and conformed by comparison of the retention times of the separated constituents with those of authentic samples and by comparison of retention indexes (RIs) of separated constituents with the RIs reported in the literature. The predominant volatile compound in FST was indole, followed by dimethyl trisulfide, phenol, dimethyl disulfide and dimethyl tetrasulfide. In order to find a better extraction time, the extraction times was optimized for each type of SPME fiber; the results show that the best extraction time for Carboxen/PDMS is 60 min, for PDMS/DVB 30 min, for DVB/CAR/PDMS 60 min and for PDMS 75 min. Of the four fibers used in this work, Carboxen/PDMS is found to be the most suitable to extract the organic volatile flavor compounds in fermented stinky tofu.

  17. Analysis of Organic Volatile Flavor Compounds in Fermented Stinky Tofu Using SPME with Different Fiber Coatings

    Directory of Open Access Journals (Sweden)

    Wei Guan

    2012-03-01

    Full Text Available The organic volatile flavor compounds in fermented stinky tofu (FST were studied using SPME-GC/MS. A total of 39 volatile compounds were identified, including nine esters, seven alcohols, five alkenes, four sulfides, three heterocycles, three carboxylic acids, three ketones, two aldehydes, one phenol, one amine and one ether. These compounds were determined by MS, and conformed by comparison of the retention times of the separated constituents with those of authentic samples and by comparison of retention indexes (RIs of separated constituents with the RIs reported in the literature. The predominant volatile compound in FST was indole, followed by dimethyl trisulfide, phenol, dimethyl disulfide and dimethyl tetrasulfide. In order to find a better extraction time, the extraction times was optimized for each type of SPME fiber; the results show that the best extraction time for Carboxen/PDMS is 60 min, for PDMS/DVB 30 min, for DVB/CAR/PDMS 60 min and for PDMS 75 min. Of the four fibers used in this work, Carboxen/PDMS is found to be the most suitable to extract the organic volatile flavor compounds in fermented stinky tofu.

  18. Development of a direct exposure system for studying the mechanisms of central neurotoxicity caused by volatile organic compounds

    OpenAIRE

    2015-01-01

    Many volatile organic compounds (VOCs) used in work places are neurotoxic. However, it has been difficult to study the cellular mechanisms induced by a direct exposure to neurons because of their high volatility. The objective of this study was to establish a stable system for exposing brain slices to VOCs. With a conventional recording system for brain slices, it is not possible to keep a constant bath concentration of relatively highly volatile solvents, e.g. 1-bromopropane (1-BP). Here we ...

  19. Effects of Organic Matter on the Growth of Thiobacillus intermedius

    Science.gov (United States)

    London, Jack; Rittenberg, Sydney C.

    1966-01-01

    London, Jack (University of California, Los Angeles), and Sydney C. Rittenberg. Effects of organic matter on the growth of Thiobacillus intermedius. J. Bacteriol. 91:1062–1069. 1966.—Yeast extract, glucose, glutamate, and other organic materials stimulate the rate and extent of growth of Thiobacillus intermedius in thiosulfate broth. Growth did not occur in glucose or glutamate mineral salts medium in the absence of thiosulfate, although a stable variant was obtained which grows on yeast extract alone. Cells harvested from media supplemented with organic matter have a reduced rate of thiosulfate oxidation (20 to 30% of autotrophic), oxidize the organic supplement, and have an additive rate of oxidation in the presence of both the organic substrate and thiosulfate. Carboxydismutase synthesis is repressed, and the incorporation of bicarbonate carbon into cell material is almost completely eliminated by the presence of organic matter in the growth medium. It is concluded that the availability of organic matter eliminates the autotrophic assimilatory mechanisms of T. intermedius but not its autotrophic energy-generating system. The data are discussed in relation to the existence of “obligate” chemoautotrophic bacteria. PMID:5929743

  20. Demonstration of Novel Sampling Techniques for Measurement of Turbine Engine Volatile and Non-Volatile Particulate Matter (PM) Emissions

    Science.gov (United States)

    2016-09-01

    found in the WP1627 project report and several journal manuscripts [25,32, 33]. 3.2.4.1 VPS Validation Experiments in Laboratory Conditions The vapor...certification process. Due to the cleaner burning engines and lack of compliance-type quantitative information, the smoke number is inadequate for...PM samples from diluted engine exhaust from the DC, CDP or plume for elemental and organic carbon (EC/OC) and sulfur product analysis. The EPA mobile

  1. Organic matter in comets and cometary dust.

    Science.gov (United States)

    Llorca, Jordi

    2005-03-01

    Comets are primitive conglomerates of the solar system containing a mixture of frozen gases, refractory grains, and carbonaceous particles rich in biogenic elements. The dramatic display of comets is mostly caused by a cloud of micrometer-sized dust particles that leave the comet nucleus when frozen gases sublimate as they approach the Sun. Analyses of cometary dust captured in the stratosphere together with data obtained from space missions to comets have revealed the presence of a great variety of organic molecules. Since substantial amounts of cometary dust were gently deposited on Earth, their organic content could have played a major role in prebiotic processes prior to the appearance of microorganisms. This review discusses the description and implications for life of the organic content of comets and cometary dust.

  2. Transplanting an organization: how does culture matter.

    Science.gov (United States)

    Munich, Richard L

    2011-01-01

    Cultural differences are often cited as a major obstacle to the successful transition/integration into new situations of organizations. In this contribution, the author details the changing cultural factors impacting the operation and move of the Menninger Clinic from autonomous status to an affiliation with and first year of operation in the Baylor College of Medicine and Methodist Hospital Health Care System. Both functional and dysfunctional consequences are outlined, and specific examples illustrate how the organization's leadership and staff struggled to adapt during this complicated process. Based on the experience within the Clinic, general recommendations for managing such an acculturation are provided.

  3. Organic Matter in Space - an Overview

    CERN Document Server

    Van Dishoeck, E F

    2008-01-01

    Organic compounds are ubiquitous in space: they are found in diffuse clouds, in the envelopes of evolved stars, in dense star-forming regions, in protoplanetary disks, in comets, on the surfaces of minor planets, and in meteorites and interplanetary dust particles. This brief overview summarizes the observational evidence for the types of organics found in these regions, with emphasis on recent developments. The Stardust sample-return mission provides the first opportunity to study primitive cometary material with sophisticated equipment on Earth. Similarities and differences between the types of compounds in different regions are discussed in the context of the processes that can modify them. The importance of laboratory astrophysics is emphasized.

  4. Bacterial Selection from Shrimp Ponds for Degradation of Organic Matters

    OpenAIRE

    Powtongsook, S.; Chanpun, K.; Suntornsuk, W.

    2007-01-01

    Accumulation of ammonia, nitrite and hydrogen sulfide in a shrimp pond is generally caused by incomplete degradation of residual organic matters from overfeeding and from organic wastes released by shrimps. The phenomenon affects shrimp growth and survival rate. The objectives of this investigation were to screen for a bacterial strain able to digest organic residues and to evaluate the changes of residues by bacterial activities under natural conditions. The results from this work showed tha...

  5. Poly(L-aspartic acid) derivative soluble in a volatile organic solvent for biomedical application.

    Science.gov (United States)

    Oh, Nam Muk; Oh, Kyung Taek; Youn, Yu Seok; Lee, Eun Seong

    2012-09-01

    In order to develop a novel functional poly(L-amino acid) that can dissolve in volatile organic solvents, we prepared poly[L-aspartic acid-g-(3-diethylaminopropyl)]-b-poly(ethylene glycol) [poly(L-Asp-g-DEAP)-b-PEG] via the conjugation of 3-diethylaminopropyl (DEAP) to carboxylate groups of poly(L-Asp) (M(n) 4 K)-b-PEG (M(n) 2 K). This poly(L-aspartic acid) derivative evidenced a relatively high solubility in volatile organic solvents such as dichloromethane, chloroform, and acetone. We fabricated a model nanostructure (i.e., polymeric micelle) using poly(L-Asp-g-DEAP)-b-PEG by the film rehydration method, which involves the simple removal of the volatile organic solvent (dichloromethane) used to dissolve polymer, reducing concerns about organic solvents remaining in a nano-sized particle. Interestingly, this micelle showed the pH-stimulated release of encapsulated model drug [i.e., doxorubicin (DOX)] due to the protonation of DEAP according to the pH of the solution. We expect that this poly(L-aspartic acid) derivative promises to provide pharmaceutical potential for constituting a new stimuli-sensitive drug carrier for various drug molecules.

  6. Assessment of indoor levels of volatile organic compounds and carbon dioxide in schools in Kuwait.

    Science.gov (United States)

    Al-Awadi, Layla

    2017-08-22

    Indoor air quality (IAQ) in schools is a matter of concern because children are most vulnerable and sensitive to pollutant exposure. Conservation of energy at the expense of ventilation in heating, ventilation, and air conditioning (HVAC) systems adversely affects IAQ. Extensive use of new materials in building, fitting, and refurbishing emit various pollutants such that the indoor environment creates its own discomfort and health risks. Various schools in Kuwait were selected to assess their IAQ. Comprehensive measurements of volatile organic compounds (VOCs) consisting of 72 organic compounds consisting of aliphatic (C3-C6), aromatic (C6-C9), halogenated (C1-C6), and oxygenated (C2-C9) functional groups in indoor air were made for the first time in schools in Kuwait. The concentrations of indoor air pollutants revealed hot spots (science preparation rooms, science laboratories, arts and crafts classes/paint rooms, and woodworking shops/decoration rooms where local sources contributed to the buildup of pollutants in each school. The most abundant VOC pollutant was chlorodifluoromethane - R22 (ClF2CH), which leaked from air conditioning (AC) systems due to improper operation and maintenance. The other copious VOCs were alcohols and acetone at different locations due to improper handling of the chemicals and their excessive uses as solvents. Indoor carbon dioxide (CO2) levels were measured, and these levels reflected the performance of HVAC systems; a specific rate or lack of ventilation affected the IAQ. Recommendations are proposed to mitigate the buildup of indoor air pollutants at school sites. Implication Indoor Air Quality in elementary schools has been subject of extreme importance due to susceptibility and sensibility of children to air pollutants. The schools were selected based on their surrounding environment especially downwind direction from the highly industrialized zone in Kuwait. Extensive sampling from different sites in four schools for

  7. Inputs of organic matter to the ocean

    NARCIS (Netherlands)

    Duce, R.A.; Duursma, E.K.

    1977-01-01

    The first objective of this introductory paper is to summarize our present understanding of the quantities of total organic carbon produced in the ocean by photosynthesis and non-biotic photochemical reactions, and the amount entering the ocean from rivers, the atmosphere, and the sediments. In this

  8. Organic matter decomposition in simulated aquaculture ponds

    NARCIS (Netherlands)

    Torres Beristain, B.

    2005-01-01

    Different kinds of organic and inorganic compounds (e.g. formulated food, manures, fertilizers) are added to aquaculture ponds to increase fish production. However, a large part of these inputs are not utilized by the fish and are decomposed inside the pond. The microbiological decomposition of the

  9. Effect of Fertilizer and Incorporated Organic Matter

    African Journals Online (AJOL)

    organic residues and fertilizer application on gaseous N20 fluxes was studied in a field trial at .... Natural fallow served as the control. .... calculated as (total fluxes from the 15 kg urea ha "'-treatment) - (total fluxes from the 0 .... SAS Release 8.1.

  10. Degradation Mechanisms of Colloidal Organic Matter in Biofilm Reactors

    DEFF Research Database (Denmark)

    Larsen, Tove; Harremoës, Poul

    1994-01-01

    The degradation mechanisms of colloidal organic matter in biofilm reactors have been studied in an idealized laboratory reactor system with soluble starch as a model substrate. Batch tests and experiments with different reactor configurations have shown that for this specific substrate, bulk liquid......-diffusible organic matter in a biofilm reactor. DH depends on the combined volumetric and surface hydraulic loading rate, Q2/(AV). In full-scale wastewater treatment plants, the degradation mechanism presented in this paper can explain important differences between the performance of trickling filters and RBC...... hydrolysis is the mechanism for transforming non-diffusible organic matter into biofilm diffusible substrate. A simplified mathematical description has led to the identification of the degree of hydrolysis, DH, as the parameter expressing the major difference between degradation of diffusible and non...

  11. Studies of volatiles and organic materials in early terrestrial and present-day outer solar system environments

    Science.gov (United States)

    Sagan, Carl; Thompson, W. Reid; Chyba, Christopher F.; Khare, B. N.

    1991-01-01

    A review and partial summary of projects within several areas of research generally involving the origin, distribution, chemistry, and spectral/dielectric properties of volatiles and organic materials in the outer solar system and early terrestrial environments are presented. The major topics covered include: (1) impact delivery of volatiles and organic compounds to the early terrestrial planets; (2) optical constants measurements; (3) spectral classification, chemical processes, and distribution of materials; and (4) radar properties of ice, hydrocarbons, and organic heteropolymers.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-06-01

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

  13. Prediction of air to liver partition coefficient for volatile organic compounds using QSAR approaches.

    Science.gov (United States)

    Dashtbozorgi, Zahra; Golmohammadi, Hassan

    2010-06-01

    In this work a quantitative structure-activity relationship (QSAR) technique was developed to investigate the air to liver partition coefficient (log Kliver) for volatile organic compounds (VOCs). Suitable set of molecular descriptors was calculated and the important descriptors were selected by GA-PLS methods. These variables were served as inputs to generate neural networks. After optimization and training of the networks, they were used for the calculation of log Kliver for the validation set. The root mean square errors for the neural network calculated log Kliver of training, test, and validation sets are 0.100, 0.091, and 0.112, respectively. Results obtained reveal the reliability and good predictivity of neural network for the prediction of air to liver partition coefficient for volatile organic compounds.

  14. [Emission characteristics and hazard assessment analysis of volatile organic compounds from chemical synthesis pharmaceutical industry].

    Science.gov (United States)

    Li, Yan; Wang, Zhe-Ming; Song, Shuang; Xu, Zhi-Rong; Xu, Ming-Zhu; Xu, Wei-Li

    2014-10-01

    In this study, volatile organic compounds (VOCs) released from chemical synthesis pharmaceutical industry in Taizhou, Zhejiang province were analyzed quantitatively and qualitatively. The total volatile organic compounds (TVOCs) was in the range of 14.9-308.6 mg · m(-3). Evaluation models of ozone formation potentials (OFP) and health risk assessment were adopted to preliminarily assess the environmental impact and health risk of VOCs. The results showed that the values of OFP of VOCs were in the range of 3.1-315.1 mg · m(-3), based on the maximum incremental reactivity, the main principal contribution was toluene, tetrahydrofuran (THF), acetic ether etc. The non-carcinogenic risk and the carcinogen risk fell in the ranges of 9.48 x 10(-7)-4.98 x 10(-4) a(-1) and 3.17 x 10(-5)- 6.33 x 10(-3). The principal contribution of VOCs was benzene, formaldehyde and methylene chloride.

  15. A method for the combined measurement of volatile and condensable organic AMC in semiconductor applications

    Science.gov (United States)

    Miller, Charles M.; Zaloga, Emily C.; Lobert, Jürgen M.

    2014-04-01

    Monitoring airborne molecular contamination (AMC) at the parts per trillion (ppt) level in cleanroom environments, scanner applications and compressed gas lines is essential for processes, equipment and yield-control. For the operation of EUV tools, in particular, volatile organic contamination is known to have as much impact as condensable organic compounds, which requires a suitable sampling and measurement methodology. Some of the current industry standards use sample traps comprised of porous 2,6-diphenylene-oxide polymer resin, such as Tenax®, for measuring volatile organic (6 C atoms, about toluene and higher) AMC. Inherent problems associated with these traps are a number of artifacts and chemical reactions that reduce accuracy of reported organic AMC concentrations. The break-down of the polymeric material forms false positive artifacts when used in the presence of reactive gases, such as nitrous acid and ozone, which attack and degrade the polymer to form detectable AMC. Most importantly, these traps have poor capture efficiency for volatile organic compounds (VOC). To address the disadvantages of polymer-based sample traps, we developed a method based on carbonaceous, multi-layered adsorbent traps to replace the 2,6-diphenylene-oxide polymer resin sample trap type. Along with the new trap's ability to retain volatile organics, the trap was found to provide artifact-free results. With industry trends towards detecting more contaminants while continuously reducing required reporting limits for those compounds, artifact-free and accurate detection of AMC is needed at the parts per quadrillion (ppq) level. The proposed, multi-layered trap substantially increases laboratory productivity and reduces cost by eliminating the need to analyze condensable and volatile organic compounds in two separate methods. In our studies, even some organic compounds with six C-atoms, that are part of exposure tool OEM requirements, were not effectively retained by polymeric

  16. Assessing Day-to-Day Volatility: Does the Trading Time Matter?

    Directory of Open Access Journals (Sweden)

    José Valentim Machado Vicente

    2014-06-01

    Full Text Available The aim of this study is to examine whether investors who trade daily but at different times have distinct perceptions about the risk of an asset. In order to capture the uncertainty faced by these investors, we define the volatility perceived by investors as the distribution of standard deviations of daily returns calculated from intraday prices collected randomly. We find that this distribution has a high degree of dispersion. This means that different investors may not share the same opinion regarding the variability of returns of the same asset. Moreover, the close-to-close volatility is often less than the median of the volatility distribution perceived by investors while the open-to-open volatility is greater than that statistic. From a practical point of view, our results indicate that volatilities estimated using traditional samples of daily returns (i.e., close-to-close and open-to-open returns may not do a good job when used as inputs in financial models since they may not properly capture the risk investors are exposed.

  17. Scavenging of soluble organic matter from the prebiotic oceans.

    Science.gov (United States)

    Nissenbaum, A

    1976-12-01

    The existence of hot or cold "nutrient broth" or "primeval soup" is challenged on the basis of the recent geochemistry of soluble organic carbon in the oceans. Most of the dissolved organic carbon is recycled quickly by organisms, but the residual, biologically refractive, organic matter is efficiently scavenged from the oceans (residence time of 1000 to 3500 years) by nonbiologically mediated chemical and physical processes, such as adsorption on sinking minerals, polymerization and aggregation to humic type polymers or by aggregation to particulate matter through bubbling and sinking of this material to the ocean bottom. Since there is no reason to believe that such nonbiological scavenging was not operative in the prebiotic oceans as well, then the prolonged existence of "organic soup" is very doubtful. The question of the origin of life is thus assumed to be related to solid-liquid interfacial activity, and the answer may be associated with sediment-water interaction rather than with solution chemistry.

  18. Performance specifications for technology development: Application for characterization of volatile organic compounds in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, S.E.; Doskey, P.V.; Erickson, M.D.; Lindahl, P.C.

    1994-07-01

    This report contains information about technology development for the monitoring and remediation of environmental pollution caused by the release of volatile organic compounds. Topics discussed include: performance specification processes, gas chromatography, mass spectrometer, fiber-optic chemical sensors, infrared spectroscopy, Raman spectroscopy, piezoelectric sensors and electrochemical sensors. These methods are analyzed for their cost efficiency, accuracy, and the ability to meet the needs of the customer.

  19. Non-methane volatile organic compound flux from a subarctic mire in Northern Sweden

    OpenAIRE

    Bäckstrand, Kristina; Crill, Patrick M.; Mastepanov, Mikhail; Christensen, Torben R.; Bastviken, David

    2011-01-01

    Biogenic NMVOCs are mainly formed by plants and microorganisms. They have strong impact on the local atmospheric chemistry when emitted to the atmosphere. The objective of this study was to determine if there are significant emissions of non-methane volatile organic compounds (NMVOCs) from a subarctic mire in northern Sweden. Subarctic peatlands in discontinuous permafrost regions are undergoing substantial environmental changes due to their high sensitivity to climate warming and there is ne...

  20. Sensory eye irritation in humans exposed to mixtures of volatile organic compounds

    DEFF Research Database (Denmark)

    Hempel-Jørgensen, Anne Hempel; Kjærgaard, Søren K.; Mølhave, Lars;

    1999-01-01

    Eight subjects participated in a controlled eyes-only exposure study of human sensory irritation in ocular mucosal tissue. The authors investigated dose-response properties and the additive effects of three mixtures of volatile organic compounds. The dose-response relationships for these mixtures...... to as simple agonism. Finally, the authors addressed the comparability of two methods to measure sensory irritation intensity (visual analogue scale and a comparative scale). The results indicated that the two rating methods produced highly comparable results....

  1. Bioactive and volatile organic compounds in Southern Brazilian blackberry (Rubus Fruticosus) fruit cv. Tupy

    OpenAIRE

    Andressa Carolina Jacques; Fábio Clasen Chaves; Rui Carlos Zambiazi; Márcia Campos Brasil; Elina Bastos Caramão

    2014-01-01

    Blackberry (Rubus fruticosus, cultivar Tupy), an expanding fruit crop in southern Brazil, is greatly appreciated for its flavor and bioactive potential with limited characterization of its metabolite content. The purpose of this study was to characterize the bioactive and volatile organic compound (VOC) content of mature blackberry fruit of cultivar Tupy. Gallic acid, (-)-epicatechin, ferulic acid, and quercetin were the main phenolic compounds found in mature fruit. Among the VOCs identified...

  2. Volatile Organic Compound (VOC) Testing at Building 348, Kelly AFB, Texas.

    Science.gov (United States)

    1987-11-01

    At the request of HQ AFLC/ SGB , the USAFOEHL conducted a stack sampling survey to determine total volatile organic compounds (VOC) being emitted from...Occupational and Environmental Health Laboratory (USAFOEHL/ECQ). The survey was requested by HQ AFLC/ SGB .to estimate VOC emissions through each of...stardards. 2. Range and Sensitivity 2.1 This method was validated over the range of 1417-5940 mg/M at an atmospheric temperature and pressure of 24 0C

  3. Influence of organic matter on collembolan communities in reedbed habitats

    Science.gov (United States)

    Uteseny, K.; Drapela, T.; Frouz, J.

    2009-04-01

    The combination of the organic matter, micro-climatic environments and plant cover belongs to important factors for the distribution of soil meso-fauna, especially Collembola. There are no studies attending to these factors on collembolan communities in reedbed vegetation. The main goals of our investigation were therefore to compare diversity of Collembola in redbed habitats of Lake Neudsiedl, eastern Austria, and to assess particularly the role of organic matter with regard to the collembolan community structure. Soil samples were taken from April 1997 to October 1997 at fifteen study sites covered with Phragmatis australis of different age. Changes in the structure and composition of the assemblages of Collembola were examined.

  4. Do soils loose phosphorus with dissolved organic matter?

    Science.gov (United States)

    Kaiser, K.; Brödlin, D.; Hagedorn, F.

    2014-12-01

    During ecosystem development and soil formation, primary mineral sources of phosphorus are becoming increasingly depleted. Inorganic phosphorus forms tend to be bound strongly to or within secondary minerals, thus, are hardly available to plants and are not leached from soil. What about organic forms of phosphorus? Since rarely studied, little is known on the composition, mobility, and bioavailability of dissolved organic phosphorus. There is some evidence that plant-derived compounds, such as phytate, bind strongly to minerals as well, while microbial compounds, such as nucleotides and nucleic acids, may represent more mobile fractions of soil phosphorus. In some weakly developed, shallow soils, leaching losses of phosphorus seem to be governed by mobile organic forms. Consequently, much of the phosphorus losses observed during initial stages of ecosystem development may be due to the leaching of dissolved organic matter. However, the potentially mobile microbial compounds are enzymatically hydrolysable. Forest ecosystems on developed soils already depleted in easily available inorganic phosphorus are characterized by rapid recycling of organic phosphors. That can reduce the production of soluble forms of organic phosphorus as well as increase the enzymatic hydrolysis and subsequent plant uptake of phosphorus bound within dissolved organic matter. This work aims at giving an outlook to the potential role of dissolved organic matter in the cycling of phosphorus within developing forest ecosystems, based on literature evidence and first results of ongoing research.

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

    Science.gov (United States)

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

    2014-05-15

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

  6. Volatile organic compounds of Thai honeys produced from several floral sources by different honey bee species.

    Science.gov (United States)

    Pattamayutanon, Praetinee; Angeli, Sergio; Thakeow, Prodpran; Abraham, John; Disayathanoowat, Terd; Chantawannakul, Panuwan

    2017-01-01

    The volatile organic compounds (VOCs) of four monofloral and one multifloral of Thai honeys produced by Apis cerana, Apis dorsata and Apis mellifera were analyzed by headspace solid-phase microextraction (HS-SPME) followed by gas chromatography and mass spectrometry (GC-MS). The floral sources were longan, sunflower, coffee, wild flowers (wild) and lychee. Honey originating from longan had more VOCs than all other floral sources. Sunflower honey had the least numbers of VOCs. cis-Linalool oxide, trans-linalool oxide, ho-trienol, and furan-2,5-dicarbaldehyde were present in all the honeys studied, independent of their floral origin. Interestingly, 2-phenylacetaldehyde was detected in all honey sample except longan honey produced by A. cerana. Thirty-two VOCs were identified as possible floral markers. After validating differences in honey volatiles from different floral sources and honeybee species, the results suggest that differences in quality and quantity of honey volatiles are influenced by both floral source and honeybee species. The group of honey volatiles detected from A. cerana was completely different from those of A. mellifera and A. dorsata. VOCs could therefore be applied as chemical markers of honeys and may reflect preferences of shared floral sources amongst different honeybee species.

  7. Biocide effects of volatile organic compounds produced by potential biocontrol rhizobacteria on Sclerotinia sclerotiorum

    Directory of Open Access Journals (Sweden)

    Annalisa eGiorgio

    2015-10-01

    Full Text Available Six rhizobacteria isolated from common bean and able to protect bean plants from the common bacterial blight causal agent, were in vitro evaluated for their potential antifungal effects toward different plant pathogenic fungi, mostly soil-borne. By dual culture assays, the above bacteria resulted producing diffusible and volatile metabolites which inhibited the growth of the majority of the pathogens under study. In particular, the latter substances highly affected the mycelium growth of Sclerotinia sclerotiorum strains, one of which was selected for further studies either on mycelium or sclerotia.Gas chromatographic analysis of the bacterial volatiles led to the identification of an array of volatile organic compounds (VOCs. Time course studies showed the modification of the VOCs profile along a period of 5 days. In order to evaluate the single detected VOC effects on fungal growth, some of the pure compounds were tested on S. sclerotiorum mycelium and their minimal inhibitory quantities were determined. Similarly, the minimal inhibitory quantities on sclerotia germination were also defined. Moreover, observations by light and transmission electron microscopes highlighted hyphae cytoplasm granulation and ultrastructural alterations at cell organelles, mostly membranes, mitochondria and endoplasmic reticulum. The membranes appeared one of the primary targets of bacterial volatiles, as confirmed by haemolytic activity observed for the majority of pure VOCs. However, of interest is the alteration observed on mitochondria as well.

  8. Volatile organic compounds produced by the phytopathogenic bacterium Xanthomonas campestris pv. vesicatoria 85-10

    Directory of Open Access Journals (Sweden)

    Teresa Weise

    2012-04-01

    Full Text Available Xanthomonas campestris is a phytopathogenic bacterium and causes many diseases of agricultural relevance. Volatiles were shown to be important in inter- and intraorganismic attraction and defense reactions. Recently it became apparent that also bacteria emit a plethora of volatiles, which influence other organisms such as invertebrates, plants and fungi. As a first step to study volatile-based bacterial–plant interactions, the emission profile of Xanthomonas c. pv. vesicatoria 85-10 was determined by using GC/MS and PTR–MS techniques. More than 50 compounds were emitted by this species, the majority comprising ketones and methylketones. The structure of the dominant compound, 10-methylundecan-2-one, was assigned on the basis of its analytical data, obtained by GC/MS and verified by comparison of these data with those of a synthetic reference sample. Application of commercially available decan-2-one, undecan-2-one, dodecan-2-one, and the newly synthesized 10-methylundecan-2-one in bi-partite Petri dish bioassays revealed growth promotions in low quantities (0.01 to 10 μmol, whereas decan-2-one at 100 μmol caused growth inhibitions of the fungus Rhizoctonia solani. Volatile emission profiles of the bacteria were different for growth on media (nutrient broth with or without glucose.

  9. Volatile organic compounds produced by the phytopathogenic bacterium Xanthomonas campestris pv. vesicatoria 85-10.

    Science.gov (United States)

    Weise, Teresa; Kai, Marco; Gummesson, Anja; Troeger, Armin; von Reuß, Stephan; Piepenborn, Silvia; Kosterka, Francine; Sklorz, Martin; Zimmermann, Ralf; Francke, Wittko; Piechulla, Birgit

    2012-01-01

    Xanthomonas campestris is a phytopathogenic bacterium and causes many diseases of agricultural relevance. Volatiles were shown to be important in inter- and intraorganismic attraction and defense reactions. Recently it became apparent that also bacteria emit a plethora of volatiles, which influence other organisms such as invertebrates, plants and fungi. As a first step to study volatile-based bacterial-plant interactions, the emission profile of Xanthomonas c. pv. vesicatoria 85-10 was determined by using GC/MS and PTR-MS techniques. More than 50 compounds were emitted by this species, the majority comprising ketones and methylketones. The structure of the dominant compound, 10-methylundecan-2-one, was assigned on the basis of its analytical data, obtained by GC/MS and verified by comparison of these data with those of a synthetic reference sample. Application of commercially available decan-2-one, undecan-2-one, dodecan-2-one, and the newly synthesized 10-methylundecan-2-one in bi-partite Petri dish bioassays revealed growth promotions in low quantities (0.01 to 10 μmol), whereas decan-2-one at 100 μmol caused growth inhibitions of the fungus Rhizoctonia solani. Volatile emission profiles of the bacteria were different for growth on media (nutrient broth) with or without glucose.

  10. Volatile organic compounds of Thai honeys produced from several floral sources by different honey bee species

    Science.gov (United States)

    Pattamayutanon, Praetinee; Angeli, Sergio; Thakeow, Prodpran; Abraham, John; Disayathanoowat, Terd; Chantawannakul, Panuwan

    2017-01-01

    The volatile organic compounds (VOCs) of four monofloral and one multifloral of Thai honeys produced by Apis cerana, Apis dorsata and Apis mellifera were analyzed by headspace solid-phase microextraction (HS-SPME) followed by gas chromatography and mass spectrometry (GC-MS). The floral sources were longan, sunflower, coffee, wild flowers (wild) and lychee. Honey originating from longan had more VOCs than all other floral sources. Sunflower honey had the least numbers of VOCs. cis-Linalool oxide, trans-linalool oxide, ho-trienol, and furan-2,5-dicarbaldehyde were present in all the honeys studied, independent of their floral origin. Interestingly, 2-phenylacetaldehyde was detected in all honey sample except longan honey produced by A. cerana. Thirty-two VOCs were identified as possible floral markers. After validating differences in honey volatiles from different floral sources and honeybee species, the results suggest that differences in quality and quantity of honey volatiles are influenced by both floral source and honeybee species. The group of honey volatiles detected from A. cerana was completely different from those of A. mellifera and A. dorsata. VOCs could therefore be applied as chemical markers of honeys and may reflect preferences of shared floral sources amongst different honeybee species. PMID:28192487

  11. Analysis of volatile organic compound from Elaeis guineensis inflorescences planted on different soil types in Malaysia

    Science.gov (United States)

    Muhamad Fahmi, M. H.; Ahmad Bukhary, A. K.; Norma, H.; Idris, A. B.

    2016-11-01

    The main attractant compound for Eleidobius kamerunicus to male spikelet Elaeis guineensis (oil palm) were determined by analyzing volatile organic compound extracted from E. guineenses inflorescences planted on different soil types namely peat soil, clay soil and sandy soil. Anthesizing male oil palm inflorescences were randomly choosen from palm aged between 4-5 years old age. Extraction of the volatiles from the oil palm inflorescences were performed by Accelerated Solvent Extraction method (ASE). The extracted volatile compound were determined by using gas chromatography-mass spectrometry. Out of ten identified compound, estragole was found to be a major compound in sandy soil (37.49%), clay soil (30.71%) and peat soil (27.79%). Other compound such as 9,12-octadecadieonic acid and n-hexadecanoic acid were found as major compound in peat soil (27.18%) and (7.45%); sandy soil (14.15 %) and (9.31%); and clay soil (30.23%) and (4.99%). This study shows that estragole was the predominant volatile compound detected in oil palm inflorescences with highly concentrated in palm planted in sandy soil type.

  12. Detection of organic matter in interstellar grains.

    Science.gov (United States)

    Pendleton, Y J

    1997-06-01

    Star formation and the subsequent evolution of planetary systems occurs in dense molecular clouds, which are comprised, in part, of interstellar dust grains gathered from the diffuse interstellar medium (DISM). Radio observations of the interstellar medium reveal the presence of organic molecules in the gas phase and infrared observational studies provide details concerning the solid-state features in dust grains. In particular, a series of absorption bands have been observed near 3.4 microns (approximately 2940 cm-1) towards bright infrared objects which are seen through large column densities of interstellar dust. Comparisons of organic residues, produced under a variety of laboratory conditions, to the diffuse interstellar medium observations have shown that aliphatic hydrocarbon grains are responsible for the spectral absorption features observed near 3.4 microns (approximately 2940 cm-1). These hydrocarbons appear to carry the -CH2- and -CH3 functional groups in the abundance ratio CH2/CH3 approximately 2.5, and the amount of carbon tied up in this component is greater than 4% of the cosmic carbon available. On a galactic scale, the strength of the 3.4 microns band does not scale linearly with visual extinction, but instead increases more rapidly for objects near the Galactic Center. A similar trend is noted in the strength of the Si-O absorption band near 9.7 microns. The similar behavior of the C-H and Si-O stretching bands suggests that these two components may be coupled, perhaps in the form of grains with silicate cores and refractory organic mantles. The ubiquity of the hydrocarbon features seen in the near infrared near 3.4 microns throughout out Galaxy and in other galaxies demonstrates the widespread availability of such material for incorporation into the many newly forming planetary systems. The similarity of the 3.4 microns features in any organic material with aliphatic hydrocarbons underscores the need for complete astronomical observational

  13. Biofiltration kinetics for volatile organic compounds (VOCs) and development of a structure-biodegradability relationship

    Energy Technology Data Exchange (ETDEWEB)

    Govind, R.; Wang, Z. [Univ. of Cincinnati, OH (United States). Dept. of Chemical Engineering; Bishop, D.F. [Environmental Protection Agency, Cincinnati, OH (United States). National Risk Management Research Lab.

    1997-12-31

    In recent years, regulation of hazardous air pollutants under the Clean Air Act and its amendments, has emerged as a major environmental issue. Major sources of volatile organic compounds (VOCs) in air are chemical production plants, manufacturing sites using common solvents, combustion sources, and waste treatment operations, such as waste water treatment plants, vacuum extraction of contaminated soils, and ground water stripping operations. Biofiltration is an emerging technology for treatment of biodegradable volatile organic compounds (VOCs) present in air. In biofiltration, the contaminants are contacted with active microorganisms present either in naturally bioactive materials, such as soil, peat, compost, etc., or immobilized on an inactive support media. Design of biofilters requires information on biodegradation kinetics which controls biofilter size. In this paper, an experimental microbiofilter system is presented which can be used to measure biofiltration kinetics for any volatile organic compound. A mathematical model is used to derive the Monod biokinetic parameters from the experimental data. Finally, a structure-bioactivity relationship is derived for estimating the biofiltration biokinetic parameters for a variety of VOCs.

  14. Highly sensitive electromembrane extraction for the determination of volatile organic compound metabolites in dried urine spot.

    Science.gov (United States)

    Suh, Joon Hyuk; Eom, Han Young; Kim, Unyong; Kim, Junghyun; Cho, Hyun-Deok; Kang, Wonjae; Kim, Da Som; Han, Sang Beom

    2015-10-16

    Electromembrane extraction coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for determination of ten volatile organic compound metabolites in dried urine spot samples. The dried urine spot approach is a convenient and economical sampling method, wherein urine is spotted onto a filter paper and dried. This method requires only a small amount of sample, but the analysis sometimes suffers from low sensitivity, which can lead to analytical problems in the detection of minor components in samples. The newly developed dried urine spot analysis using electromembrane extraction exhibited improved sensitivity and extraction, and enrichment of the sample was rapidly achieved in one step by applying an electric field. Aliquots of urine were spotted onto Bond Elut DMS cards and dried at room temperature. After drying, the punched out dried urine spot was eluted with water. Volatile organic compound metabolites were extracted from the sample through a supported liquid membrane into an alkaline acceptor solution inside the lumen of a hollow fiber with the help of an electric potential. The optimum extraction conditions were determined by using design of experiments (fractional factorial design and response surface methodology). Satisfactory sensitivity was achieved and the limits of quantification (LOQ) obtained were lower than the regulatory threshold limits. The method was validated by assessing the linearity, precision, accuracy, recovery, reproducibility, stability, and matrix effects. The results were acceptable, and the developed method was successfully applied to biological exposure monitoring of volatile organic compound metabolites in fifty human urine samples.

  15. Soil Samplers: New Techniques for Subsurface Sampling for Volatile Organic Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Susan Sorini; John Schabron; Joseph Rovani; Mark Sanderson

    2009-03-31

    Soil sampling techniques for volatile organic analysis must be designed to minimize loss of volatile organic compounds (VOCs) from the soil that is being sampled. Preventing VOC loss from soil cores that are collected from the subsurface and brought to the surface for subsampling is often difficult. Subsurface bulk sample retrieval systems are designed to obtain intact cylindrical cores of soil ranging anywhere from one to four inches in diameter, and one to several feet in length. The current technique that is used to subsample these soil cores for VOC analysis is to expose a horizontal section of the soil core to the atmosphere; screen the exposed soil using a photoionization detector (PID) or other appropriate device to locate contamination in the soil core; and use a hand-operated coring tool to collect samples from the exposed soil for analysis. Because the soil core can be exposed to the atmosphere for a considerable length of time during screening and sample collection, the current sub-sampling technique provides opportunity for VOCs to be lost from the soil. This report describes three alternative techniques from the current technique for screening and collecting soil samples from subsurface soil cores for VOC analysis and field testing that has been done to evaluate the techniques. Based on the results of the field testing, ASTM D4547, Standard Guide for Sampling Waste and Soils for Volatile Organic Compounds, was revised to include information about the new techniques.

  16. Andic soils : mineralogical effect onto organic matter dynamics, organic matter effect onto mineral dynamics, or both?

    Science.gov (United States)

    Basile-Doelsch, Isabelle; Amundson, Ronald; Balesdent, Jérome; Borschneck, Daniel; Bottero, Jean-Yves; Colin, Fabrice; de Junet, Alexis; Doelsch, Emmanuel; Legros, Samuel; Levard, Clément; Masion, Armand; Meunier, Jean-Dominique; Rose, Jérôme

    2014-05-01

    From a strictly mineralogical point of view, weathering of volcanic glass produces secondary phases that are short range ordered alumino-silicates (SRO-AlSi). These are imogolite tubes (2 to 3 nm of diameter) and allophane supposedly spheres (3.5 to 5 nm). Their local structure is composed of a curved gibbsite Al layer and Si tetrahedra in the vacancies (Q0). Proto-imogolites have the same local structure but are roof-shape nanoparticles likely representing the precursors of imogolite and allophanes (Levard et al. 2010). These structures and sizes give to the SRO-AlSi large specific surfaces and high reactivities. In some natural sites, imogolites and allophanes are formed in large quantities. Aging of these phases may lead to the formation of more stable minerals (halloysite, kaolinite and gibbsite) (Torn et al 1997). In natural environments, when the weathering of volcanic glass is associated with the establishment of vegetation, the soils formed are generally andosols. These soils are particularly rich in organic matter (OM), which is explained by the high ability of SRO-AlSi mineral phases to form bonds with organic compounds. In a first order "bulk" approach, it is considered that these bonds strongly stabilize the organic compounds as their mean age can reach more than 10 kyrs in some studied sites (Basile-Doelsch et al. 2005; Torn et al. 1997). However, the structure of the mineral phases present in andosols deserves more attention. Traditionally, the presence in the SRO-AlSi andosols was shown by selective dissolution approaches by oxalate and pyrophosphate. Using spectroscopic methods, mineralogical analysis of SRO-AlSi in andosols samples showed that these mineral phases were neither imogolites nor allophanes as originally supposed, but only less organized structures remained in a state of proto-imogolites (Basile-Doelsch al. 2005 ; Levard et al., 2012). The presence of OM would have an inhibitory effect on the formation of secondary mineral phases, by

  17. Potential contribution of semi-volatile and intermediate volatility primary organic compounds to secondary organic aerosol in the Mexico City region

    Directory of Open Access Journals (Sweden)

    A. Hodzic

    2010-01-01

    Full Text Available It has been established that observed local and regional levels of secondary organic aerosols (SOA in polluted areas cannot be explained by the oxidation and partitioning of anthropogenic and biogenic VOC precursors, at least using current mechanisms and parameterizations. In this study, the 3-D regional air quality model CHIMERE is applied to quantify the contribution to SOA formation of recently identified semi-volatile and intermediate volatility organic vapors (S/IVOC in and around Mexico City for the MILAGRO field experiment during March 2006. The model has been updated to include explicitly the volatility distribution of primary organic aerosols (POA, their gas-particle partitioning and the gas-phase oxidation of the vapors. Two recently proposed parameterizations, those of Robinson et al. (2007 ("ROB" and Grieshop et al. (2009 ("GRI" are compared and evaluated against surface and aircraft measurements. The 3-D model results are assessed by comparing with the concentrations of OA components from Positive Matrix Factorization of Aerosol Mass Spectrometer (AMS data, and for the first time also with oxygen-to-carbon ratios derived from high-resolution AMS measurements.

    The results show a substantial enhancement in predicted SOA concentrations (3–6 times with respect to the previously published base case without S/IVOCs (Hodzic et al., 2009, both within and downwind of the city leading to much reduced discrepancies with the total OA measurements. The predicted anthropogenic POA levels are found to agree within 20% with the observed HOA concentrations for both the ROB and GRI simulations, consistent with the interpretation of the emissions inventory by previous studies. The impact of biomass burning POA within the city is underestimated in comparison to the AMS BBOA, presumably due to insufficient nighttime smoldering emissions. Model improvements in OA predictions are associated with the better-captured SOA magnitude and diurnal

  18. Composition of dissolved organic matter in groundwater

    Science.gov (United States)

    Longnecker, Krista; Kujawinski, Elizabeth B.

    2011-05-01

    Groundwater constitutes a globally important source of freshwater for drinking water and other agricultural and industrial purposes, and is a prominent source of freshwater flowing into the coastal ocean. Therefore, understanding the chemical components of groundwater is relevant to both coastal and inland communities. We used electrospray ionization coupled with Fourier-transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) to examine dissolved organic compounds in groundwater prior to and after passage through a sediment-filled column containing microorganisms. The data revealed that an unexpectedly high proportion of organic compounds contained nitrogen and sulfur, possibly due to transport of surface waters from septic systems and rain events. We matched 292 chemical features, based on measured mass:charge ( m/z) values, to compounds stored in the Kyoto Encyclopedia of Genes and Genomes (KEGG). A subset of these compounds (88) had only one structural isomer in KEGG, thus supporting tentative identification. Most identified elemental formulas were linked with metabolic pathways that produce polyketides or with secondary metabolites produced by plants. The presence of polyketides in groundwater is notable because of their anti-bacterial and anti-cancer properties. However, their relative abundance must be quantified with appropriate analyses to assess any implications for public health.

  19. Adsorption combined with ultrafiltration to remove organic matter from seawater.

    Science.gov (United States)

    Tansakul, Chatkaew; Laborie, Stéphanie; Cabassud, Corinne

    2011-12-01

    Organic fouling and biofouling are the major severe types of fouling of reverse osmosis (RO) membranes in seawater (SW) desalination. Low pressure membrane filtration such as ultrafiltration (UF) has been developed as a pre-treatment before reverse osmosis. However, UF alone may not be an effective enough pre-treatment because of the existence of low-molecular weight dissolved organic matter in seawater. Therefore, the objective of the present work is to study a hybrid process, powdered activated carbon (PAC) adsorption/UF, with real seawater and to evaluate its performance in terms of organic matter removal and membrane fouling. The effect of different PAC types and concentrations is evaluated. Stream-activated wood-based PAC addition increased marine organic matter removal by up to 70% in some conditions. Moreover, coupling PAC adsorption with UF decreased UF membrane fouling and the fouling occurring during short-term UF was totally reversible. It can be concluded that the hybrid PAC adsorption/UF process performed in crossflow filtration mode is a relevant pre-treatment process before RO desalination, allowing organic matter removal of 75% and showing no flux decline for short-term experiments.

  20. Caracterisation of anthropogenic contribution to the coastal fluorescent organic matter

    Science.gov (United States)

    El Nahhal, Ibrahim; Nouhi, Ayoub; Mounier, Stéphane

    2015-04-01

    It is known that most of the coastal fluorescent organic matter is of a terrestrial origin (Parlanti, 2000; Tedetti, Guigue, & Goutx, 2010). However, the contribution of the anthropogenic organic matter to this pool is not well defined and evaluated. In this work the monitoring of little bay (Toulon Bay, France) was done in the way to determine the organic fluorescent response during a winter period. The sampling campaign consisted of different days during the month of December, 2014 ( 12th, 15th, 17th, 19th) on 21 different sampling sites for the fluorescence measurements (without any filtering of the samples) and the whole month of December for the bacterial and the turbidity measurements. Excitation Emission Matrices (EEMs) of fluorescence (from 200 to 400 nm and 220 to 420 nm excitation and emission range) were treated by parallel factor analysis (PARAFAC).The parafac analysis of the EEM datasets was conducted using PROGMEEF software in Matlab langage. On the same time that the turbidity and bacterial measurement (particularly the E.Coli concentration) were determined. The results gives in a short time range, information on the the contribution of the anthropogenic inputs to the coastal fluorescent organic matter. In addition, the effect of salinity on the photochemical degradation of the anthropogenic organic matter (especially those from wastewater treatment plants) will be studied to investigate their fate in the water end member by the way of laboratory experiments. Parlanti, E. (2000). Dissolved organic matter fluorescence spectroscopy as a tool to estimate biological activity in a coastal zone submitted to anthropogenic inputs. Organic Geochemistry, 31(12), 1765-1781. doi:10.1016/S0146-6380(00)00124-8 Tedetti, M., Guigue, C., & Goutx, M. (2010). Utilization of a submersible UV fluorometer for monitoring anthropogenic inputs in the Mediterranean coastal waters. Marine Pollution Bulletin, 60(3), 350-62. doi:10.1016/j.marpolbul.2009.10.018

  1. Interstellar and Solar System Organic Matter Preserved in Interplanetary Dust

    Science.gov (United States)

    Messenger, Scott; Nakamura-Messenger, Keiko

    2015-01-01

    Interplanetary dust particles (IDPs) collected in the Earth's stratosphere derive from collisions among asteroids and by the disruption and outgassing of short-period comets. Chondritic porous (CP) IDPs are among the most primitive Solar System materials. CP-IDPs have been linked to cometary parent bodies by their mineralogy, textures, C-content, and dynamical histories. CP-IDPs are fragile, fine-grained (less than um) assemblages of anhydrous amorphous and crystalline silicates, oxides and sulfides bound together by abundant carbonaceous material. Ancient silicate, oxide, and SiC stardust grains exhibiting highly anomalous isotopic compositions are abundant in CP-IDPs, constituting 0.01 - 1 % of the mass of the particles. The organic matter in CP-IDPs is isotopically anomalous, with enrichments in D/H reaching 50x the terrestrial SMOW value and 15N/14N ratios up to 3x terrestrial standard compositions. These anomalies are indicative of low T (10-100 K) mass fractionation in cold molecular cloud or the outermost reaches of the protosolar disk. The organic matter shows distinct morphologies, including sub-um globules, bubbly textures, featureless, and with mineral inclusions. Infrared spectroscopy and mass spectrometry studies of organic matter in IDPs reveals diverse species including aliphatic and aromatic compounds. The organic matter with the highest isotopic anomalies appears to be richer in aliphatic compounds. These materials also bear similarities and differences with primitive, isotopically anomalous organic matter in carbonaceous chondrite meteorites. The diversity of the organic chemistry, morphology, and isotopic properties in IDPs and meteorites reflects variable preservation of interstellar/primordial components and Solar System processing. One unifying feature is the presence of sub-um isotopically anomalous organic globules among all primitive materials, including IDPs, meteorites, and comet Wild-2 samples returned by the Stardust mission.

  2. Aggregation of organic matter by pelagic tunicates

    Energy Technology Data Exchange (ETDEWEB)

    Pomeroy, L.R. (Univ. of Georgia, Athens); Deibel, D.

    1980-07-01

    Three genera of pelagic tunicates were fed concentrates of natural seston and an axenic diatom culture. Fresh and up to 4-day-old feces resemble flocculent organic aggregates containing populations of microorganisms, as described from highly productive parts of the ocean, and older feces resemble the nearly sterile flocculent aggregates which are ubiquitous in surface waters. Fresh feces consist of partially digested phytoplankton and other inclusions in an amorphous gelatinous matrix. After 18 to 36 h, a population of large bacteria develops in the matrix and in some of the remains of phytoplankton contained in the feces. From 48 to 96 h, protozoan populations arise which consume the bacteria and sometimes the remains of the phytoplankton in the feces. Thereafter only a sparse population of microorganisms remains, and the particles begin to fragment. Water samples taken in or below dense populations of salps and doliolids contained greater numbers of flocculent aggregates than did samples from adjacent stations.

  3. Volatile organo-selenium speciation in biological matter by solid phase microextraction-moderate temperature multicapillary gas chromatography with microwave induced plasma atomic emission spectrometry detection

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, C.; Sanz Landaluze, J.; Ximenez-Embun, P.; Madrid-Albarran, Y.; Camara, C

    2004-01-16

    Microwave induced plasma atomic emission spectrometry (MIP-AES) in combination with multicapillary (MC) gas chromatography could be proven to be useful for element specific detection of volatile species. Solid phase microextraction (SPME) was used for preconcentration and sample-matrix separation. The fiber desorption unit as well as the heating control for the MC column were in-house developed and multicapillary column was operated at moderate temperatures (30-100 deg. C). The method was optimized for organo-selenium species (dimethylselenide (DMSe), diethylselenide (DEtSe) and dimethyldiselenide (DMDSe)), using a chemometric approach. Stationary phases for the separation column were optimized using a conventional GC and contrasted with the results obtained with the MC. Application was focussed on selenium accumulating biological matter, such as lupine, yeast, Indian mustard and garlic. These samples were grown in hydroponic solution containing inorganic selenium (Na{sub 2}SeO{sub 3} and Na{sub 2}SeO{sub 4}). SPME sampling was carried out in fixed volume flow boxes in headspace above the living plants and in vials using treated samples. Results demonstrate inorganic selenium transformation into volatile organic species during metabolism. Separation is fast, a chromatogram can be obtained in less than 3 min and detection limits were at sub-ppb level for all investigated species. The system is independent from the use of a conventional gas chromatographic oven and can be used as a versatile alternative to highly cost intensive methods such as GC-ICP-MS.

  4. Ultrathin organic semiconductor films--soft matter effect.

    Science.gov (United States)

    Wang, Tong; Yan, Donghang

    2014-05-01

    The growth of organic semiconductor thin films has been a crucial issue in organic electronics, especially the growth at the early stages. The thin-film phase has been found to be a common phenomenon in many organic semiconductor thin films, which is closely related with the weak van der Waals interaction between organic molecules, the long-range interaction between organic molecules and the substrate, as well as the soft matter characteristics of ultrathin films. The growth behavior and soft matter characteristics of the thin-film phase have great effects on thin film morphology and structure, for example, the formation and coalescence of grain boundaries, which further influences the performance of organic electronic devices. The understanding of thin-film phase and its intrinsic quality is necessary for fabricating large-size, highly ordered, continuous and defect-free ultrathin films. This review will focus on the growth behavior of organic ultrathin films, i.e., the level of the first several molecular layers, and provide an overview of the soft matter characteristics.

  5. Microorganisms Associated with Volatile Organic Compound Production in Spoilt Mango Fruits

    Directory of Open Access Journals (Sweden)

    Aliyu D. Ibrahim

    2015-11-01

    Full Text Available Microorganisms associated with the production of volatile compound in spoilt mango fruits sold in Sokoto town were isolated and identified. The organisms include seven species of bacteria and a species of yeast. These include Bacillus pumilus, Bacillus firmus, Brevibacillus laterosporus, Morganella morganii, Paenibacillus alvei, Staphylococcus saccharolyticus, Listeria monocytogenes and Candida krusei respectively. GC-MS analysis revealed the presence of eleven and sixteen volatile organic compound in the healthy and spoilt ripe mango fruits. Octadecanoic acid, oleic acid, 1 – Butanol, 3 – methyl-, carbonate (2:1 and 3,7 – Dimethyl nonane were common to both healthy and spoilt fruits with the first three having higher concentration in healthy fruits than spoilt while the later had higher concentration in the spoilt. One methyl group of 3,3- Dimethyl hexane in healthy fruit was shifted to position two to yield 2,3-Dimethyl hexane in the spoilt fruits. 2,2-Dimethylbutane, Methyl(methyl-4-deoxy-2,3-di-O-methyl.beta.1-threo-hex-4-enopyranosid urinate, 3-(4-amino-phenyl-2-(toluene-4-sulfonylamino-propionic acid, 2-Methyl-3-heptanone, 3,5-Nonadien-7-yn-2-ol, (E,E, Butanoic acid, 1,1-dimethylethyl ester, 1-methyl-3-beta.phenylethyl-2,4,5-trioxoimidazolidine, Pentanoic acid, 2,2-dimethyl, ethyl ester (Vinyl 2,2-dimethylpentanoate, 4-Methyurazole, 1-Tridecyn- 4 – 9 – ol, 1-Hexyl-1-nitrocyclohexane were unique to spoilt fruits. This study suggests that these unique volatile metabolites could be exploited as biomarkers to discriminate pathogens even when more than one disease is present thereby curbing post harvest loss during storage after further validation and the volatile organic compound could form the basis for constructing a metabolomics database for Nigeria.

  6. Can particulate organic matter reveal emerging changes in soil organic carbon?

    DEFF Research Database (Denmark)

    Simonsson, Magnus; Kirchmann, Holger; Magid, Jakob

    2014-01-01

    . Although organic matter in Fraction B had a higher intrinsic sensitivity to soil management, which was partly able to overcome the larger errors, we concluded that an observer would be more likely to detect changes by measuring total organic C and N, when monitoring decadal changes in C and N pools......This study assessed whether particulate organic matter (POM) in sand fractions, isolated by wet sieving after treatment with Na hexametaphosphate, can be a sensitive indicator of incipient changes in the content and composition of soil organic matter. In five long-term field experiments including....... This makes the investigated POM fractions less suitable as indicators for changes in soil C stocks. However, the C/N ratio of Fraction B showed a distinct signature of the history of organic matter input to the soil, which was absent in the C/N ratio of the total fine earth....

  7. Biodegradable organic matter in municipal solid waste incineration bottom ash.

    Science.gov (United States)

    Zhang, Shuo; Herbell, Jan-Dirk; Gaye-Haake, Birgit

    2004-01-01

    For investigation of the behavior of municipal solid waste incineration bottom ash in landfill, we have analysed bottom ash samples taken after the quench tank as well as after five months of storage in the laboratory for elements and organic constituents. Water extractable organic carbon, particulate organic carbon, amino acids, hexosamines and carbohydrates considerably decreased during the five months of storage and their spectra revealed microbial reworking. This shows that the organic matter present in the bottom ash after incineration can provide a substrate for microbial activity. The resulting changes of the physico-chemical environment may effect the short-term behavior of the bottom ash in landfill. Copyright 2004 Elsevier Ltd.

  8. Non-methane volatile organic compounds in Africa: A view from space

    Science.gov (United States)

    Marais, Eloise Ann

    Isoprene emissions affect human health, air quality, and the oxidative capacity of the atmosphere. Globally anthropogenic non-methane volatile organic compounds (NMVOC) emissions are lower than that of isoprene, but local hotspots are hazardous to human health and air quality. In Africa the tropics are a large source of isoprene, while Nigeria appears as a large contributor to regional anthropogenic NMVOC emissions. I make extensive use of space-based formaldehyde (HCHO) observations from the Ozone Monitoring Instrument (OMI) and the chemical transport model (CTM) GEOS-Chem to estimate and examine seasonality of isoprene emissions across Africa, and identify sources and air quality consequences of anthropogenic NMVOC emissions in Nigeria. To estimate isoprene emissions I first developed a filtering scheme to remove (1) contamination from biomass burning and anthropogenic influences; and (2) displacement of HCHO from the isoprene emission source diagnosed with the GEOS-Chem CTM. Conversion to isoprene emissions is with NOx-dependent GEOS-Chem HCHO yields, obtained as the local sensitivity S of the HCHO column ΩHCHO to a perturbation Delta in isoprene emissions EISOP (S = DeltaΩHCHO/DeltaE ISOP). The error in OMI-derived isoprene emissions is 40% at low levels of NOx and 40-90% under high-NOx conditions and is reduced by spatial and temporal averaging to the extent that errors are random. Weak isoprene emission seasonality in equatorial forests is driven predominantly by temperature, while large seasonality in northern and southern savannas is driven by temperature and leaf area index. The largest contribution of African isoprene emissions to surface ozone and particulate matter, determined with GEOS-Chem, of 8 ppbv and 1.5 μg m-3, respectively, is over West Africa. The OMI HCHO data feature a large enhancement over Nigeria that is due to anthropogenic NMVOC emissions. With the OMI HCHO data, coincident satellite observations of atmospheric composition, aircraft

  9. Development of an In-Fiber Nanocavity Towards Detection of Volatile Organic Gases

    Directory of Open Access Journals (Sweden)

    Francisco J. Arregui

    2006-06-01

    Full Text Available A fiber optic sensor for Volatile Organic Compounds (VOCs detection has beendeveloped and characterized for some organic gasses. The sensor is based on a novelvapochromic material, which is able to change its optical properties in presence of organicvapors in a reversely way. A nano Fabry Perot is constructed onto a cleaved ended opticalfiber pigtail by Electrostatic Self Assembly method (ESA, doping this structure with thevapochromic material. Employing a reflection scheme, a change in the intensity modulatedreflected signal at 850 nm have been registered. The response of the sensor has beenevaluated for five different VOCs, and a deeper study has been made for vapors of threedifferent alcohols.

  10. Integration of organic based Schottky junctions for crossbar non-volatile memory applications

    DEFF Research Database (Denmark)

    Katsia, E.; Tallarida, G.; Ferrari, S.

    2008-01-01

    Small size Schottky junctions using two different synthesized organic semiconductors (oligophenylene-vinylenes) were integrated by standard UV lithography into crossbar arrays. The proposed integration scheme can be applied to a wide class of organics without affecting material properties. Current......-voltage characteristics were studied in order to investigate which of the tested compounds could possibly reach the requirements for non-volatile memory applications. All the investigated devices displayed good rectifying properties, ranging from 10(2) to 10(4). On the other hand, one of the compounds reveals higher...

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

    Science.gov (United States)

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

    2014-06-01

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

  12. Analysis of build-up of heavy metals and volatile organics on urban roads in gold coast, Australia.

    Science.gov (United States)

    Mahbub, Parvez; Goonetilleke, Ashantha; Ayoko, Godwin A; Egodawatta, Prasanna; Yigitcanlar, Tan

    2011-01-01

    Urban water quality can be significantly impaired by the build-up of pollutants such as heavy metals and volatile organics on urban road surfaces due to vehicular traffic. Any control strategy for the mitigation of traffic related build-up of heavy metals and volatile organic pollutants should be based on the knowledge of their build-up processes. In the study discussed in this paper, the outcomes of a detailed experimental investigation into build-up processes of heavy metals and volatile organics are presented. It was found that traffic parameters such as average daily traffic, volume over capacity ratio and surface texture depth had similar strong correlations with the build-up of heavy metals and volatile organics. Multicriteria decision analyses revealed that that the 1-74 microm particulate fraction of total suspended solids (TSS) could be regarded as a surrogate indicator for particulate heavy metals in build-up and this same fraction of total organic carbon could be regarded as a surrogate indicator for particulate volatile organics build-up. In terms of pollutants affinity, TSS was found to be the predominant parameter for particulate heavy metals build-up and total dissolved solids was found to be the predominant parameter for the potential dissolved particulate fraction in heavy metals buildup. It was also found that land use did not play a significant role in the build-up of traffic generated heavy metals and volatile organics.

  13. Lyophilization and Reconstitution of Reverse Osmosis Concentrated Natural Organic Matter

    Science.gov (United States)

    Disinfection by-product (DBP) research can be complicated by difficulties in shipping large water quantities and changing natural organic matter (NOM) characteristics over time. To overcome these issues, it is advantageous to have a reliable method for concentrating and preservin...

  14. The energetic and chemical signatures of persistent soil organic matter

    DEFF Research Database (Denmark)

    Barré, Pierre; Plante, Alain F.; Cecillon, Lauric

    2016-01-01

    A large fraction of soil organic matter (OM) resists decomposition over decades to centuries as indicated by long radiocarbon residence times, but the mechanisms responsible for the long-term (multi-decadal) persistence are debated. The current lack of mechanistic understanding limits our ability...

  15. Selective depletion of organic matter in mottled podzol horizons

    NARCIS (Netherlands)

    Buurman, P.; Schellekens, J.; Fritze, H.; Nierop, K.G.J.

    2007-01-01

    Abstract: Some well-drained podzols on quartz sands in the Netherlands and neighbouring Belgium and Germany show mottling in all horizons due to selective removal of organic matter. Phospholipid analysis and morphology of the mottles suggests that this removal is due to activity of fungi. Investigat

  16. Lyophilization and Reconstitution of Reverse Osmosis Concentrated Natural Organic Matter

    Science.gov (United States)

    Disinfection by-product (DBP) research can be complicated by difficulties in shipping large water quantities and changing natural organic matter (NOM) characteristics over time. To overcome these issues, it is advantageous to have a reliable method for concentrating and preservin...

  17. Advanced solid-state NMR spectroscopy of natural organic matter

    Science.gov (United States)

    Solid-state NMR is essential for the characterization of natural organic matter (NOM) and is gaining importance in geosciences and environmental sciences. This review is intended to highlight advanced solid-state NMR techniques, especially the systematic approach to NOM characterization, and their ...

  18. Large ancient organic matter contributions to Arctic marine sediments (Svalbard)

    NARCIS (Netherlands)

    Kim, J.-H.; Peterse, F.; Willmott, V.; Klitgaard Kristensen, D.; Baas, M.; Schouten, S.; Sinninghe Damsté, J.S.

    2011-01-01

    Soils, fine-grained ice-rafted detritus (IRD), coals, and marine surface sediments in the Arctic realm (Svalbard) were collected in 2007 and 2008 to characterize organic matter (OM) sources in Arctic marine sediments. Bulk geochemical (C : N ratio and stable carbon isotopic composition) parameters s

  19. Large ancient organic matter contributions to Arctic marine sediments (Svalbard)

    NARCIS (Netherlands)

    Kim, J.-H.; Peterse, F.; Willmott, V.; Klitgaard Kristensen, D.; Baas, M.; Schouten, S.; Sinninghe Damsté, J.S.

    2011-01-01

    Soils, fine-grained ice-rafted detritus (IRD), coals, and marine surface sediments in the Arctic realm (Svalbard)were collected in 2007 and 2008 to characterize organic matter (OM) sources in Arctic marine sediments. Bulkgeochemical (C : N ratio and stable carbon isotopic composition) parameters sug

  20. SOMPROF: A vertically explicit soil organic matter model

    NARCIS (Netherlands)

    Braakhekke, M.C.; Beer, M.; Hoosbeek, M.R.; Kruijt, B.; Kabat, P.

    2011-01-01

    Most current soil organic matter (SOM) models represent the soil as a bulk without specification of the vertical distribution of SOM in the soil profile. However, the vertical SOM profile may be of great importance for soil carbon cycling, both on short (hours to years) time scale, due to

  1. Reactivity of Organic Matter and other Reductants in Aquifer Sediments

    NARCIS (Netherlands)

    Hartog, N.

    2003-01-01

    The molecular composition and the carbon isotope signature of sedimentary organic matter (SOM) and indicate that SOM is predominantly derived from higher land plants in sediments of both terrestrial as marine origins. The reactivity of SOM in the aquifer sediments studied is determined by the extent

  2. Organic matter dynamics in coarse sandy calcareous soils

    NARCIS (Netherlands)

    Pronk, A.A.; Reuler, van H.

    2011-01-01

    The decomposition of organic matter in coarse sandy calcareous soils (beach sand) is thought to be much higher than in acid fine sandy soils but relatively little research is performed on these soils. Laboratory incubation experiments in which the release of soil carbon (C) is determined may overest

  3. Inner filter correction of dissolved organic matter fluorescence

    DEFF Research Database (Denmark)

    Kothawala, D.N.,; Murphy, K.R.; Stedmon, Colin

    2013-01-01

    The fluorescence of dissolved organic matter (DOM) is suppressed by a phenomenon of self-quenching known as the inner filter effect (IFE). Despite widespread use of fluorescence to characterize DOM in surface waters, the advantages and constraints of IFE correction are poorly defined. We assessed...

  4. Phase partitioning and volatility of secondary organic aerosol components formed from α-pinene ozonolysis and OH oxidation: the importance of accretion products and other low volatility compounds

    Directory of Open Access Journals (Sweden)

    F. D. Lopez-Hilfiker

    2015-02-01

    Full Text Available We measured a large suite of gas and particle phase multi-functional organic compounds with a Filter Inlet for Gases and AEROsols (FIGAERO coupled to a high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS developed at the University of Washington. The instrument was deployed on environmental simulation chambers to study monoterpene oxidation as a secondary organic aerosol (SOA source. We focus here on results from experiments utilizing an ionization method most selective towards acids (acetate negative ion proton transfer, but our conclusions are based on more general physical and chemical properties of the SOA. Hundreds of compounds were observed in both gas and particle phases, the latter being detected upon temperature programmed thermal desorption of collected particles. Particulate organic compounds detected by the FIGAERO HR-ToF-CIMS are highly correlated with, and explain at least 25–50% of, the organic aerosol mass measured by an Aerodyne Aerosol Mass Spectrometer (AMS. Reproducible multi-modal structures in the thermograms for individual compounds of a given elemental composition reveal a significant SOA mass contribution from large molecular weight organics and/or oligomers (i.e. multi-phase accretion reaction products. Approximately 50% of the HR-ToF-CIMS particle phase mass is associated with compounds having effective vapor pressures 4 or more orders of magnitude lower than commonly measured monoterpene oxidation products. The relative importance of these accretion-type and other extremely low volatility products appears to vary with photochemical conditions. We present a desorption temperature based framework for apportionment of thermogram signals into volatility bins. The volatility-based apportionment greatly improves agreement between measured and modeled gas–particle partitioning for select major and minor components of the SOA, consistent with thermal decomposition during desorption causing

  5. Synthesis of refractory organic matter in the ionized gas phase of the solar nebula.

    Science.gov (United States)

    Kuga, Maïa; Marty, Bernard; Marrocchi, Yves; Tissandier, Laurent

    2015-06-01

    In the nascent solar system, primitive organic matter was a major contributor of volatile elements to planetary bodies, and could have played a key role in the development of the biosphere. However, the origin of primitive organics is poorly understood. Most scenarios advocate cold synthesis in the interstellar medium or in the outer solar system. Here, we report the synthesis of solid organics under ionizing conditions in a plasma setup from gas mixtures (H2(O)-CO-N2-noble gases) reminiscent of the protosolar nebula composition. Ionization of the gas phase was achieved at temperatures up to 1,000 K. Synthesized solid compounds share chemical and structural features with chondritic organics, and noble gases trapped during the experiments reproduce the elemental and isotopic fractionations observed in primitive organics. These results strongly suggest that both the formation of chondritic refractory organics and the trapping of noble gases took place simultaneously in the ionized areas of the protoplanetary disk, via photon- and/or electron-driven reactions and processing. Thus, synthesis of primitive organics might not have required a cold environment and could have occurred anywhere the disk is ionized, including in its warm regions. This scenario also supports N2 photodissociation as the cause of the large nitrogen isotopic range in the solar system.

  6. A mass transfer model for predicting emission of the volatile organic compounds in wet building materials

    Institute of Scientific and Technical Information of China (English)

    ZHANG Tao; JIA Li

    2008-01-01

    A new mass transfer model is developped to predict the volatile organic compounds (VOCs) from fresh wet building materials. The dry section of wet materials during the process of VOC emission from wet building materials is considered in this new model, differing from the mass transfer-based models in other literatures. The mechanism of effect of saturated vapor pressure on the surface of wet building materials in the process of VOC emission is discussed. The concentration of total volatile organic compounds (TVOC) in the building materials gradually decreases as the emission of VOCs begins, and the vapor pressure of VOCs on the surface of wet building materials decreases in the case of newly wet building materials. To ensure the partial pressure of VOCs on the surface of wet building materials to be saturated vapor pressure, the interface of gas-wet layer is lowered, and a dry layer of no-volatile gases in the material is formed. Compared with the results obtained by VB model, CFD model and the ex-periment data, the results obtained by the present model agree well with the results obtained by CFD model and the experiment data. The present model is more accurate in predicting emission of VOC from wet building materials than VB model.

  7. Final report on CCQM-K47: Volatile organic compounds in methanol

    Science.gov (United States)

    Pérez Urquiza, Melina; Maldonado Torres, Mauricio; Mitani, Yoshito; Schantz, Michele M.; Duewer, David L.; May, Wille E.; Parris, Reenie M.; Wise, Stephen A.; Kaminski, Katja; Philipp, Rosemarie; Win, Tin; Rosso, Adriana; Kim, Dal Ho; Ishikawa, Keiichiro; Krylov, A. I.; Kustikov, Y. A.; Baldan, Annarita

    2013-01-01

    At the October 2005 CCQM Organic Analysis Working Group Meeting (IRMM, Belgium), the decision was made to proceed with a Key Comparison study (CCQM-K47) addressing the calibration function for the determination of volatile organic compounds (VOCs) used for water quality monitoring. This was coordinated by CENAM and NIST. Benzene, o-xylene, m-xylene and p-xylene were chosen as representative VOCs. The solvent of choice was methanol. Key Comparison CCQM-K47 demonstrated the capabilities of participating NMIs to identify and measure the four target VOCs in a calibration solution using GC-based methods. The measurement challenges in CCQM-K47, such as avoiding volatility loss, achieving adequate chromatographic resolution and isolating potential interferences, are typical of those required for value-assigning volatile reference materials. Participants achieving comparable measurements for all four VOCs in this Key Comparison should be capable of providing reference materials and measurements for VOCs in solutions when present at concentration levels greater than 10 µg/g. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  8. Removal of volatile organic compounds using amphiphilic cyclodextrin-coated polypropylene

    Directory of Open Access Journals (Sweden)

    Ludmilla Lumholdt

    2014-11-01

    Full Text Available Polypropylene nonwovens were functionalised using a self-assembled, amphiphilic cyclodextrin coating and the potential for water purification by removal of pollutants was studied. As benzene is one of the problematic compounds in the Water Framework Directive, six volatile organic compounds (benzene and five benzene-based substances were chosen as model compounds. The compounds were tested as a mixture in order to provide a more realistic situation since the wastewater will be a complex mixture containing multiple pollutants. The volatile organic compounds are known to form stable inclusion complexes with cyclodextrins. Six different amphiphilic cyclodextrin derivatives were synthesised in order to elucidate whether or not the uptake abilities of the coating depend on the structure of the derivative. Headspace gas chromatography was used for quantification of the uptake exploiting the volatile nature of benzene and its derivatives. The capacity was shown to increase beyond the expected stoichiometries of guest–host complexes with ratios of up to 16:1.

  9. The Relationship Between Dissolved Organic Matter Composition and Organic Matter Optical Properties in Freshwaters

    Science.gov (United States)

    Aiken, G.; Spencer, R. G.; Butler, K.

    2010-12-01

    Dissolved organic matter (DOM) chemistry and flux are potentially useful, albeit, underutilized, indicators of watershed characteristics, climate influences on watershed hydrology and soils, and changes associated with resource management. Source materials, watershed geochemistry, oxidative processes and hydrology exert strong influences on the nature and reactivity of DOM in aquatic systems. The molecules that comprise DOM, in turn, control a number of environmental processes important for ecosystem function including light penetration and photochemistry, microbial activity, mineral dissolution/precipitation, and the transport and reactivity of hydrophobic compounds and metals (e.g. Hg). In particular, aromatic molecules derived from higher plants exert strong controls on aquatic photochemistry, and on the transport and biogeochemistry of metals. Assessment of DOM composition and transport, therefore, can provide a basis for understanding watershed processes and biogeochemistry of rivers and streams. Here we present results of multi-year studies designed to assess the seasonal and spatial variability of DOM quantity and quality for 57 North American Rivers. DOM concentrations and composition, based on DOM fractionation on XAD resins, ultraviolet (UV)/visible absorption and fluorescence spectroscopic analyses, and specific compound analyses, varied greatly both between sites and seasonally within a given site. DOM in these rivers exhibited a wide range of concentration (4000 µM C* L-1) and specific ultra-violet absorbance at 254 nm (SUVA254) (0.6 to 5 L *mg C-1 *m-1), an optical measurement that is an indicator of aromatic carbon content. In almost all systems, UV absorbance measured at specific wavelengths (e.g. 254 nm) correlated strongly with DOM and hydrophobic organic acid (HPOA) content (aquatic humic substances). The relationships between dissolved organic carbon (DOC) concentration and absorbance for the range of systems were quite variable due to

  10. Assessment of volatile organic compounds in surface water at Canal Creek, Aberdeen Proving Ground, Maryland, November 1999-September 2000

    Science.gov (United States)

    Phelan, Daniel J.; Olsen, Lisa D.; Senus, Michael P.; Spencer, Tracey A.

    2001-01-01

    The purpose of this report is to describe the occurrence and distribution of volatile organic compounds in surface-water samples collected by the U.S. Geological Survey in the Canal Creek area of Aberdeen Proving Ground, Maryland, from November 1999 through September 2000. The report describes the differences between years with below normal and normal precipitation, the effects of seasons, tide stages, and location on volatile organic compound concentrations in surface water, and provides estimates of volatile organic concentration loads to the tidal Gunpowder River. Eighty-four environmental samples from 20 surface-water sites were analyzed. As many as 13 different volatile organic compounds were detected in the samples. Concentrations of volatile organic compounds in surface-water samples ranged from below the reporting limit of 0.5 micrograms per liter to a maximum of 50.2 micrograms per liter for chloroform. Chloroform was detected most frequently, and was found in 55 percent of the environmental samples that were analyzed for volatile organic compounds (46 of 84 samples). Carbon tetrachloride was detected in 56 percent of the surface-water samples in the tidal part of the creek (34 of 61 samples), but was only detected in 3 of 23 samples in the nontidal part of the creek. 1,1,2,2-Tetrachloroethane was detected in 43 percent of the tidal samples (26 of 61 samples), but was detected at only two nontidal sites and only during November 1999. Three samples were collected from the tidal Gunpowder River about 300 feet from the mouth of Canal Creek in May 2000, and none of the samples contained volatile organic compound concentrations above detection levels. Volatile organic compound concentrations in surface water were highest in the reaches of the creek adjacent to the areas with the highest known levels of ground-water contamination. The load of total volatile organic compounds from Canal Creek to the Gunpowder River is approximately 1.85 pounds per day (0

  11. First results on headspace-solid phase microextraction-gas chromatography/mass spectrometry of volatile organic compounds emitted by wax objects in museums.

    Science.gov (United States)

    Lattuati-Derieux, A; Thao, S; Langlois, J; Regert, M

    2008-04-11

    Sampling volatile organic compounds (VOCs) emitted by a large variety of materials is nowadays a very useful technique for analytical purpose. In the field of cultural heritage, it can be applied to identify some constituents of museum artefacts off-gassing VOCs without sampling on the object itself. In this study, we focused on objects made of wax. First volatiles emitted by a reference beeswax were trapped and identified by headspace-solid phase microextraction (HS-SPME)-gas chromatography and mass spectrometry (GC/MS). This allowed to identify numerous volatile biomarkers, namely saturated n-alkanes from C(10) to C(21), saturated n-carboxylic acids containing 6-12 carbon atoms, benzene and cinnamic derivatives that may be considered as volatile biomarkers of beeswax. The SPME strategy was then performed at the Orsay museum (Paris) in a showcase containing a wax sculpture "Le Mineur de la Loire" by J.-J. Carriès. The use of beeswax in this sculpture was unequivocally confirmed by the VOCs concentrated in the showcase, together with a set of characteristic molecular compounds identified by HT-GC/MS. HS-SPME-GC/MS thus appears to be a powerful in situ and non-invasive analytical technique that allows to identify natural substances in the field of cultural heritage without any sampling of solid matter from the object. The results obtained are promising for orientating the strategy of preventive conservation related to works of art characterised by important emission of VOCs.

  12. Volatile organic compounds and Photobacterium phosphoreum associated with spoilage of modified-atmosphere-packaged raw pork

    DEFF Research Database (Denmark)

    Nieminen, Timo T.; Dalgaard, Paw; Björkroth, Johanna

    2016-01-01

    Accumulation of volatile organic compounds was monitored in association with sensory quality, bacterial concentrations and culture-independent microbial community analyses in raw pork loin and pork collar during storage under high-oxygen modified atmosphere at +4°C. Of the 48 volatile compounds....... According to the culture-dependent and culture-independent characterization of bacterial communities, Brochothrix thermosphacta, lactic acid bacteria (Carnobacterium, Lactobacillus, Lactococcus, Leuconostoc, Weissella) and Photobacterium spp. predominated in pork samples. Photobacterium spp., typically...... not associated with spoilage of meat, were detected also in 8 of the 11 retail packages of pork investigated subsequently. Eleven isolates from the pork samples were shown to belong to Photobacterium phosphoreum by phenotypic tests and sequencing of the 16S rRNA and gyrB gene fragments. Off-odors in pork samples...

  13. Volatile organic compounds in pharmacy – the range of the problem

    Directory of Open Access Journals (Sweden)

    Marzena Jamrógiewicz

    2013-09-01

    Full Text Available The sensitivity and chemical instability of the active pharmaceutical ingredients (API may result in the formation and emission of volatile substances which affect not only the stability of the medicinal product, but also leads to changes of physicochemical properties, causing negative pharmacologic effects sometimes toxic. For this reason, it is important to conduct routine stability tests, as well as, to determine gaseous degradation products using modern analytical methods, often unconventional. Knowledge of medicinal chemistry, physical chemistry, technology and toxicology is needed to provide a stable form of the drug and its utmost therapeutic effect. Available guidelines on determined volatile organic compounds (VOCs present in samples of drug substances have been verified , types of VOCs have been specified and classified. Current literature reviewed shows the results of determination of VOCs in active drug compounds and medicinal products, including discussion on various possibilities of their detection and identification. Currently used methods are based on gas chromatography and ion mobility spectrometry IMS.

  14. Analytical modeling of the subsurface volatile organic vapor concentration in vapor intrusion.

    Science.gov (United States)

    Shen, Rui; Pennell, Kelly G; Suuberg, Eric M

    2014-01-01

    The inhalation of volatile and semi-volatile organic compounds that intrude from a subsurface contaminant source into indoor air has become the subject of health and safety concerns over the last twenty years. Building subslab and soil gas contaminant vapor concentration sampling have become integral parts of vapor intrusion field investigations. While numerical models can be of use in analyzing field data and in helping understand the subslab and soil gas vapor concentrations, they are not widely used due to the perceived effort in setting them up. In this manuscript, we present a new closed-form analytical expression describing subsurface contaminant vapor concentrations, including subslab vapor concentrations. The expression was derived using Schwarz-Christoffel mapping. Results from this analytical model match well the numerical modeling results. This manuscript also explores the relationship between subslab and exterior soil gas vapor concentrations, and offers insights on what parameters need to receive greater focus in field studies.

  15. Accretion and Preservation of Organic Matter in Carbonaceous Chondrites as Revealed by NanoSIMS Imaging.

    Science.gov (United States)

    Remusat, L.; Guan, Y.; Eiler, J.

    2008-12-01

    Carbonaceous chondrites are the most primitive known meteorites. Their parent bodies accreted several discrete components of the early solar system: CAIs, other silicates, oxides, sulfides, ice, organics, and noble gases. Radioactive decay of short live radionucleides quickly heated these parent bodies and drove thermal metamorphism and aqueous alteration of their constituents. Despite this post-acretionary modification, at least some components of the organic matter in the carbaceous chondrites retained distinctive isotopic and molecular properties that may relate to their pre-acretionary origins in the protosolar nebula or in the molecular cloud that gave birth to it [1]. These processes that gave rise to early solar-system organic matter and the extent to which it was modified by parent body processes are still a matter of debate [2]. We have acquired NanoSIMS images of matrices of several CI, CM, CR and CV chondrites to document, in- situ, the distribution of organics and their textural and chemical relationships to co-existing inorganic components. Importantly, we performed these analyses on essentially unmodified fragments of matrix material pressed into indium, rather than on extracts, which have been the focus of most previous work on meteoritic organic matter. Specifically, we simultaneously collected H, D, 12C, 18O, 26CN, 28Si and 32S with a spatial resolution of 200 nm. Inorganic constituents of the imaged domains were determined by SEM imaging and EDS analysis. We identify two textural classes of organic constituents: diffuse organic matter and organic particles ~ 1 micron in diameter. The particles are common and do not exhibit any textural association with any inorganic matrix constituent. This distribution is consistent with previous observations by fluorescence optical microscopy [3]. These organic particles are likely primarily composed of insoluble organic matter (IOM) that grew prior to accretion as pure organic particules and was preserved in

  16. Exposure to Volatile Organic Compounds and Possibility of Exposure to By-product Volatile Organic Compounds in Photolithography Processes in Semiconductor Manufacturing Factories.

    Science.gov (United States)

    Park, Seung-Hyun; Shin, Jung-Ah; Park, Hyun-Hee; Yi, Gwang Yong; Chung, Kwang-Jae; Park, Hae-Dong; Kim, Kab-Bae; Lee, In-Seop

    2011-09-01

    The purpose of this study was to measure the concentration of volatile organic compound (VOC)s originated from the chemicals used and/or derived from the original parental chemicals in the photolithography processes of semiconductor manufacturing factories. A total of four photolithography processes in 4 Fabs at three different semiconductor manufacturing factories in Korea were selected for this study. This study investigated the types of chemicals used and generated during the photolithography process of each Fab, and the concentration levels of VOCs for each Fab. A variety of organic compounds such as ketone, alcohol, and acetate compounds as well as aromatic compounds were used as solvents and developing agents in the processes. Also, the generation of by-products, such as toluene and phenol, was identified through a thermal decomposition experiment performed on a photoresist. The VOC concentration levels in the processes were lower than 5% of the threshold limit value (TLV)s. However, the air contaminated with chemical substances generated during the processes was re-circulated through the ventilation system, thereby affecting the airborne VOC concentrations in the photolithography processes. Tens of organic compounds were being used in the photolithography processes, though the types of chemical used varied with the factory. Also, by-products, such as aromatic compounds, could be generated during photoresist patterning by exposure to light. Although the airborne VOC concentrations resulting from the processes were lower than 5% of the TLVs, employees still could be exposed directly or indirectly to various types of VOCs.

  17. Natural organic matter properties in Swedish agricultural streams

    Science.gov (United States)

    Bieroza, Magdalena; Kyllmar, Katarina; Bergström, Lars; Köhler, Stephan

    2017-04-01

    The following paper shows natural organic matter (NOM) properties of stream water samples collected from 8 agricultural streams and 12 agricultural observational fields in Sweden. The catchments and observational fields cover a broad range of environmental (climate, soil type), land use and water quality (nutrient and concentrations, pH, alkalinity) characteristics. Stream water samples collected every two weeks within an ongoing Swedish Monitoring Programme for Agriculture have been analysed for total/dissolved organic carbon, absorbance and fluorescence spectroscopy. A number of quantitative and qualitative spectroscopic parameters was calculated to help to distinguish between terrestrially-derived, refractory organic material and autochthonous, labile material indicative of biogeochemical transformations of terrestrial NOM and recent biological production. The study provides insights into organic matter properties and carbon budgets in agricultural streams and improves understanding of how agricultural catchments transform natural and anthropogenic fluxes of organic matter and nutrients. The insights from the grab sampling are supported by high-frequency turbidity, fulvic-like and tryptophan-like fluorescence measurements with in situ optical sensor.

  18. HUMIFIED FRACTION OF ORGANIC MATTER DUE TO PLANT MIXTURE CULTIVATION

    Directory of Open Access Journals (Sweden)

    TONY JARBAS FERREIRA CUNHA

    2016-01-01

    Full Text Available The aim of this study was to assess the organic matter changes in quantity and quality, particularly of the humic fraction in the surface layer (0–20 cm, of a Typic Plinthustalf soil under different management of plant mixtures used as green manure for mango (Mangifera indica L. crops. The plant mixtures, which were seeded between rows of mango trees, were formed by two groups of leguminous and non-leguminous plants. Prior to sowing, seeds were combined in different proportions and compositions constituting the following treatments: 100% non-leguminous species (NL; 100% leguminous species (L; 75% L and 25% NL; 50% L and 50% NL; 25% L and 75% NL; and 100% spontaneous vegetation, considered a control. The plant mixtures that grew between rows of mango trees caused changes in the chemical composition of the soil organic matter, especially for the treatments 50% L and 50% NL and 25% L and 75% NL, which increased the content of humic substances in the soil organic matter. However, the treatment 25% L and 75% NL was best at minimising loss of total organic carbon from the soil. The humic acids studied have mostly aliphatic characteristics, showing large amounts of carboxylic and nitrogen groups and indicating that most of the organic carbon was formed by humic substances, with fulvic acid dominating among the alkali soluble fractions.

  19. Cumulative effects of biochar, mineral and organic fertilizers on soil organic matter

    Science.gov (United States)

    Plaza, César; López-de-Sá, Esther G.; Gascó, Gabriel; Méndez, Ana; Zaccone, Claudio

    2016-04-01

    We investigated the effect of three consecutive annual applications of biochar at rates of 0 and 20 t ha-1, in a factorial combination with a mineral fertilizer (NPK and nitrosulfate) and two types of organic amendment (municipal solid waste compost and sewage sludge), on soil organic matter in a field experiment under Mediterranean conditions. Biochar increased significantly soil organic C content and C/N ratio. In biochar-amended soils, soil organic C increased significantly with the addition of municipal solid waste compost and sewage sludge. To capture organic matter protection mechanisms related to aggregation and mineral interaction, the soil samples will be fractionated into free (unprotected), intra-macroaggregate, intra-microaggregate, and mineral-associated organic matter pools, and the isolated fractions will be subjected to further chemical and spectroscopic analysis.

  20. Microbial bioavailability regulates organic matter preservation in marine sediments

    Directory of Open Access Journals (Sweden)

    K. A. Koho

    2012-09-01

    Full Text Available Burial of organic matter (OM plays an important role in marine sediments, linking the short-term, biological carbon cycle with the long-term, geological subsurface cycle. It is well established that low-oxygen conditions promote organic carbon burial in marine sediments. However, the mechanism remains enigmatic. Here we report biochemical quality, microbial degradability, OM preservation and accumulation along an oxygen gradient in the Indian Ocean. Our results show that more OM, and of biochemically higher quality, accumulates under low oxygen conditions. Nevertheless, microbial degradability does not correlate with the biochemical quality of OM. This decoupling of OM biochemical quality and microbial degradability, or bioavailability, violates the ruling paradigm that higher quality implies higher microbial processing. The inhibition of bacterial OM remineralisation may play an important role in the burial of organic matter in marine sediments and formation of oil source rocks.

  1. Influence of pasture-based feeding systems on fatty acids, organic acids and volatile organic flavour compounds in yoghurt.

    Science.gov (United States)

    Akbaridoust, Ghazal; Plozza, Tim; Trenerry, V Craige; Wales, William J; Auldist, Martin J; Ajlouni, Said

    2015-08-01

    The influence of different pasture-based feeding systems on fatty acids, organic acids and volatile organic flavour compounds in yoghurt was studied. Pasture is the main source of nutrients for dairy cows in many parts of the world, including southeast Australia. Milk and milk products produced in these systems are known to contain a number of compounds with positive effects on human health. In the current study, 260 cows were fed supplementary grain and forage according to one of 3 different systems; Control (a traditional pasture based diet offered to the cows during milking and in paddock), PMR1 (a partial mixed ration which contained the same supplement as Control but was offered to the cows as a partial mixed ration on a feedpad), PMR 2 (a differently formulated partial mixed ration compared to Control and PMR1 which was offered to the cows on a feedpad). Most of the yoghurt fatty acids were influenced by feeding systems; however, those effects were minor on organic acids. The differences in feeding systems did not lead to the formation of different volatile organic flavour compounds in yoghurt. Yet, it did influence the relative abundance of these components.

  2. The role of low-volatility organic compounds in initial particle growth in the atmosphere

    Science.gov (United States)

    Tröstl, Jasmin; Chuang, Wayne K.; Gordon, Hamish; Heinritzi, Martin; Yan, Chao; Molteni, Ugo; Ahlm, Lars; Frege, Carla; Bianchi, Federico; Wagner, Robert; Simon, Mario; Lehtipalo, Katrianne; Williamson, Christina; Craven, Jill S.; Duplissy, Jonathan; Adamov, Alexey; Almeida, Joao; Bernhammer, Anne-Kathrin; Breitenlechner, Martin; Brilke, Sophia; Dias, Antònio; Ehrhart, Sebastian; Flagan, Richard C.; Franchin, Alessandro; Fuchs, Claudia; Guida, Roberto; Gysel, Martin; Hansel, Armin; Hoyle, Christopher R.; Jokinen, Tuija; Junninen, Heikki; Kangasluoma, Juha; Keskinen, Helmi; Kim, Jaeseok; Krapf, Manuel; Kürten, Andreas; Laaksonen, Ari; Lawler, Michael; Leiminger, Markus; Mathot, Serge; Möhler, Ottmar; Nieminen, Tuomo; Onnela, Antti; Petäjä, Tuukka; Piel, Felix M.; Miettinen, Pasi; Rissanen, Matti P.; Rondo, Linda; Sarnela, Nina; Schobesberger, Siegfried; Sengupta, Kamalika; Sipilä, Mikko; Smith, James N.; Steiner, Gerhard; Tomè, Antònio; Virtanen, Annele; Wagner, Andrea C.; Weingartner, Ernest; Wimmer, Daniela; Winkler, Paul M.; Ye, Penglin; Carslaw, Kenneth S.; Curtius, Joachim; Dommen, Josef; Kirkby, Jasper; Kulmala, Markku; Riipinen, Ilona; Worsnop, Douglas R.; Donahue, Neil M.; Baltensperger, Urs

    2016-05-01

    About half of present-day cloud condensation nuclei originate from atmospheric nucleation, frequently appearing as a burst of new particles near midday. Atmospheric observations show that the growth rate of new particles often accelerates when the diameter of the particles is between one and ten nanometres. In this critical size range, new particles are most likely to be lost by coagulation with pre-existing particles, thereby failing to form new cloud condensation nuclei that are typically 50 to 100 nanometres across. Sulfuric acid vapour is often involved in nucleation but is too scarce to explain most subsequent growth, leaving organic vapours as the most plausible alternative, at least in the planetary boundary layer. Although recent studies predict that low-volatility organic vapours contribute during initial growth, direct evidence has been lacking. The accelerating growth may result from increased photolytic production of condensable organic species in the afternoon, and the presence of a possible Kelvin (curvature) effect, which inhibits organic vapour condensation on the smallest particles (the nano-Köhler theory), has so far remained ambiguous. Here we present experiments performed in a large chamber under atmospheric conditions that investigate the role of organic vapours in the initial growth of nucleated organic particles in the absence of inorganic acids and bases such as sulfuric acid or ammonia and amines, respectively. Using data from the same set of experiments, it has been shown that organic vapours alone can drive nucleation. We focus on the growth of nucleated particles and find that the organic vapours that drive initial growth have extremely low volatilities (saturation concentration less than 10-4.5 micrograms per cubic metre). As the particles increase in size and the Kelvin barrier falls, subsequent growth is primarily due to more abundant organic vapours of slightly higher volatility (saturation concentrations of 10-4.5 to 10

  3. 77 FR 16981 - Air Quality: Revision to Definition of Volatile Organic Compounds-Exclusion of a Group of Four...

    Science.gov (United States)

    2012-03-23

    ... AGENCY 40 CFR Part 51 RIN 2060-AO17 Air Quality: Revision to Definition of Volatile Organic Compounds... organic compounds (VOCs) for purposes of preparing State Implementation Plans (SIPs) to attain the... VOCs that can be released into the atmosphere. VOCs are those organic compounds of carbon which...

  4. Development and validation of a portable gas phase standard generation and calibration system for volatile organic compounds

    Science.gov (United States)

    P. Veres; J. B. Gilman; J. M. Roberts; W. C. Kuster; C. Warneke; I. R. Burling; J. de Gouw

    2010-01-01

    We report on the development of an accurate, portable, dynamic calibration system for volatile organic compounds (VOCs). The Mobile Organic Carbon Calibration System (MOCCS) combines the production of gas-phase VOC standards using permeation or diffusion sources with quantitative total organic carbon (TOC) conversion on a palladium surface to CO2 in the presence of...

  5. A novel inlet system for on-line chemical analysis of semi-volatile submicron particulate matter

    Directory of Open Access Journals (Sweden)

    P. Eichler

    2014-09-01

    Full Text Available We herein present the concept of a novel modular inlet system that allows using gas-phase analyzers for on-line chemical characterization of semi-volatile submicron particles. The "chemical analysis of aerosol on-line" (CHARON inlet consists of a gas-phase denuder for stripping off gas-phase analytes, an aerodynamic lens for particle enrichment in the sampling flow and a thermo-desorption unit for particle volatilization prior to chemical analysis. We coupled the CHARON inlet to a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS which quantitatively detects most organic analytes and ammonia. The combined set-up measures submicron organic and ammonium nitrate/sulfate particles online. Two proof-of-principle studies were carried out for demonstrating the analytical power of the new set-up in analyzing primarily emitted and secondarily generated particles. Oxygenated organics and their partitioning between the gas and the particulate phase were observed from the reaction of limonene with ozone. Abundant quasi-molecular ions of organic particulate constituents were observed when submicron particles were sampled from diluted mainstream cigarette smoke.

  6. Methodology for the detection of contamination by hydrocarbons and further soil sampling for volatile and semi-volatile organic enrichment in former petrol stations, SE Spain

    Directory of Open Access Journals (Sweden)

    Rosa María Rosales Aranda

    2012-01-01

    Full Text Available The optimal detection and quantification of contamination plumes in soil and groundwater by petroleum organic compounds, gasoline and diesel, is critical for the reclamation of hydrocarbons contaminated soil at petrol stations. Through this study it has been achieved a sampling stage optimization in these scenarios by means of the location of potential contamination areas before sampling with the application of the 2D electrical resistivity tomography method, a geophysical non destructive technique based on resistivity measurements in soils. After the detection of hydrocarbons contaminated areas, boreholes with continuous coring were performed in a petrol station located in Murcia Region (Spain. The drillholes reached depths down to 10 m and soil samples were taken from each meter of the drilling. The optimization in the soil samples handling and storage, for both volatile and semi-volatile organic compounds determinations, was achieved by designing a soil sampler to minimize volatilization losses and in order to avoid the manual contact with the environmental samples during the sampling. The preservation of soil samples was performed according to Europe regulations and US Environmental Protection Agency recommendations into two kinds of glass vials. Moreover, it has been taken into account the determination techniques to quantify the hydrocarbon pollution based on Gas Chromatography with different detectors and headspace technique to reach a liquid-gas equilibrium for volatile analyses.

  7. Aggregate Development and Organic Matter Storage in Mediterranean Mountain Soils

    Institute of Scientific and Technical Information of China (English)

    R.M.POCH; M.ANT(U)NEZ

    2010-01-01

    Soil aggregation and organic matter of soils from the pre-Pyrenean range in Catalonia (NE Spain) were studied, in order to assess their quality as carbon sinks and also to select the best soil management practices to preserve their quality.Aggregate stability, organic carbon and micromorphology were investigated. The highest amount of organic carbon was found in alluvial, deep soils (228 Mg C ha-1), and the lowest was in a shallow, stony soil with a low plant cover (78 Mg C ha-1). Subsurface horizons of degraded soils under pastures were the ones with smaller and less-stable aggregates.Fresh residues of organic matter (OM) were found mostly in interaggregate spaces. Within the aggregates there were some organic remains that were beginning to decompose, and also impregnative nodules of amorphous OM. Although OM was evenly distributed among the aggregate fractions, the larger blocky peels had more specific surface, contained less decomposed OM and had a lower organic/mineral interphase than smaller crumb aggregates, which were also more stable.Soil carbon storage was affected primarily by the OM inputs in the surface horizons. In order to store organic carbon over the mid- and long-term periods, the mechanisms favouring structuration through biological activity and creating small aggregates with intrapedal stable microporosities seemed to be the most effective.

  8. Detection of rare species of volatile organic selenium metabolites in male golden hamster urine.

    Science.gov (United States)

    Kwak, Jae; Ohrnberger, Sarah A; Valencak, Teresa G

    2016-07-01

    Selenium has been considered as an essential trace element in mammals and its intake comes mainly from food. Mammals can metabolize both inorganic and organic species, and urinary excretion is the primary elimination route of selenium. Selenosugars and trimethylselenonium ion have been identified as major urinary metabolites. Other metabolites have been reported, but they were detected in some studies and not in others. Still, a large portion of the ingested selenium eliminated from the body is unknown. Volatile selenium species may account for a certain portion of the unknown species since they can easily be lost during sample analyses. While we analyzed male golden hamster urine in search of potential volatile pheromone(s), four volatile selenium compounds were detected. They were dimethyl selenenylsulfide, dimethyl diselenide, dimethyl bis(thio)selenide, and dimethyl selenodisulfide. When the urine samples were aged and dried for 48 h, dimethyl selenodisulfide tended to increase, while others decreased. The increase might be due to the formation of dimethyl selenodisulfide via reaction of dimethyl diselenide and dimethyl trisulfide whose concentration increased as urine aged. To our knowledge, dimethyl bis(thio)selenide and dimethyl selenodisulfide have never been demonstrated in urine. It remains to be determined whether these species are common metabolites in other animals or hamster-specific.

  9. Analysis of volatile organic compounds in compost samples: A potential tool to determine appropriate composting time.

    Science.gov (United States)

    Zhu, Fengxiang; Pan, Zaifa; Hong, Chunlai; Wang, Weiping; Chen, Xiaoyang; Xue, Zhiyong; Yao, Yanlai

    2016-12-01

    Changes in volatile organic compound contents in compost samples during pig manure composting were studied using a headspace, solid-phase micro-extraction method (HS-SPME) followed by gas chromatography with mass spectrometric detection (GC/MS). Parameters affecting the SPME procedure were optimized as follows: the coating was carbon molecular sieve/polydimethylsiloxane (CAR/PDMS) fiber, the temperature was 60°C and the time was 30min. Under these conditions, 87 compounds were identified from 17 composting samples. Most of the volatile components could only be detected before day 22. However, benzenes, alkanes and alkenes increased and eventually stabilized after day 22. Phenol and acid substances, which are important factors for compost quality, were almost undetectable on day 39 in natural compost (NC) samples and on day 13 in maggot-treated compost (MC) samples. Our results indicate that the approach can be effectively used to determine the composting times by analysis of volatile substances in compost samples. An appropriate composting time not only ensures the quality of compost and reduces the loss of composting material but also reduces the generation of hazardous substances. The appropriate composting times for MC and NC were approximately 22days and 40days, respectively, during the summer in Zhejiang.

  10. Laboratory experimental simulations: Chemical evolution of the organic matter from interstellar and cometary ice analogs

    Science.gov (United States)

    Abou Mrad, N.; Vinogradoff, V.; Duverney, F.; Danger, G.; Theulé, P.; Borget, F.; Chiavassa, T.

    2015-01-01

    This contribution addresses the different approaches that are developed in our laboratory to study the chemical evolution of organic matter in stellar or interplanetary environments. In the first approach, starting from interstellar or cometary ice analogs subjected to different energy processes (thermal, photochemical), we aim to explain the mechanism of formation of key molecules (RING project: Reactivity in INterstellar ice Grains) such as HMT, POM or amino acid precursors that are or may be detected in future space missions. In a second approach, we are interested in the detection of volatile molecules sublimating from ice analogs when these latter are heated and/or irradiated (VAHIIA project: Volatile Analysis from the Heating of Interstellar Ice Analogs) through an online experimental device coupling the simulation chamber where ices are formed to a GC-MS instrument. The objective is thus to simulate the effects of the ice material warming when a young star forms or when a comet becomes active. This project provides an inventory of molecules that can be found in hot corinos or in the gaseous phase of comets. In a third approach, we analyze the organic matter contained in the refractory residues that can be considered as cometary analogs (RAHIIA Project: Residue Analysis from the Heating of Interstellar Ice Analogs) using very high resolution mass spectrometry (VHRMS). The results of these analyses show that residues present an important molecular diversity. This technique gives also the possibility to determine the elementary composition of these residues that can be compared to the meteorite composition. These residues can then be a basic material to develop, in a specific planetary environment, a prebiotic chemistry.

  11. Effect of Cultivation on Soil Organic Matter and Aggregate Stability

    Institute of Scientific and Technical Information of China (English)

    A.WILLIAMS; XING Bao-Shan; P.VENEMAN

    2005-01-01

    Agricultural sustainability relates directly to maintaining or enhancing soil quality. Soil quality studies in Canada during the 1980's showed that loss of soil organic matter (SOM) and soil aggregate stability was standard features of non-sustainable land management in agroecosystems. In this study total soil organic carbon (SOC), particulate organic matter (POM), POM-C as a percentage of total SOC, and aggregate stability were determined for three cultivated fields and three adjacent grassland fields to assess the impact of conventional agricultural management on soil quality. POM was investigated using solid-state 13C nuclear magnetic resonance (NMR) to determine any qualitative differences that may be attributed to cultivation. Results show a highly significant loss in total SOC, POM and aggregate stability in the cultivated fields as compared to the grassland fields and a significant loss of POM-C as a percentage of total SOC.Integrated results of the NMR spectra of the POM show a loss in carbohydrate-C and an increase in aromatic-C in the cultivated fields, which translates to a loss of biological lability in the organic matter. Conventional cultivation decreased the quantity and quality of SOM and caused a loss in aggregate stability resulting in an overall decline in soil quality.

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

    Science.gov (United States)

    Boczkaj, Grzegorz; Przyjazny, Andrzej; Kamiński, Marian

    2014-07-01

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

  13. Differential mercury volatilization by tobacco organs expressing a modified bacterial merA gene

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Mercury pollution is a major environmental problem accompanying industrial activities. Most of the mercury released ends up and retained in the soil as complexes of the toxic ionic mercury (Hg2+), which then can be converted by microbes into the even more toxic methylmercury which tends to bioaccumulate. Mercury detoxification of the soil can also occur by microbes converting the ionic mercury into the least toxic metallic mercury (Hg0) form, which then evaporates. The remediation potential of transgenic plants carrying the MerA gene from E. Coli encoding mercuric ion reductase could be evaluated. A modified version of the gene, optimized for plant codon preferences (merApe9, Rugh et al. 1996), was introduced into tobacco by Agrobacterium-mediated leaf disk transformation. Transgenic seeds were resistant to HgCl2 at 50 μM, and some of them (10-20%) could germinate on media containing as much as 350 μM HgCl2, while the control plants were fully inhibited or died on 50μM HgCl2. The rate of elemental mercury evolution from Hg2+ (added as HgCl2) was 5-8 times higher for transgenic plants than the control. Mercury volatilization by isolated organs standardized for fresh weight was higher (up to 5 times) in the roots than in shoots or the leaves. The data suggest that it is the root system of the transgenic plants that volatilizes most of the reduced mercury (Hg0). It also suggests that much of the mercury need not enter the vascular system to be transported to the leaves for volatilization. Transgenic plants with the merApe9 gene may be used to mercury detoxification for environmental improvement in mercury-contaminated regions more efficiently than it had been predicted based on data on volatilization of whole plants via the upper parts only (Rugh et al. 1996).

  14. Fabrication of spray-printed organic non-volatile memory devices for low cost electronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Cha, An-Na [Soft Innovative Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, San 101 Eunha-ri, Bongdong-eup, Wanju-gun, Jeollabuk-do (Korea, Republic of); Professional Graduate School of Flexible and Printable Electronics and Polymer Materials Fusion Research Center, Chonbuk National University, 664-14, Deokjin-dong, Deokjin-gu, Jeonju-si, Jeollabuk-do 561-756 (Korea, Republic of); Ji, Yongsung [Soft Innovative Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, San 101 Eunha-ri, Bongdong-eup, Wanju-gun, Jeollabuk-do (Korea, Republic of); Lee, Sang-A [Soft Innovative Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, San 101 Eunha-ri, Bongdong-eup, Wanju-gun, Jeollabuk-do (Korea, Republic of); Department of Polymer-Nano Science and Technology, Chonbuk National University, 664-14 Duckjin-dong, Duckjin-gu, Jeonju 561-756 (Korea, Republic of); Noh, Yong-Young [Department of Energy and Materials Engineering, Dongguk University, 26 Pil-dong, 3-Ga, Jung-gu, Seoul 100-715 (Korea, Republic of); Na, Seok-In [Professional Graduate School of Flexible and Printable Electronics and Polymer Materials Fusion Research Center, Chonbuk National University, 664-14, Deokjin-dong, Deokjin-gu, Jeonju-si, Jeollabuk-do 561-756 (Korea, Republic of); Bae, Sukang; Lee, Sanghyun [Soft Innovative Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, San 101 Eunha-ri, Bongdong-eup, Wanju-gun, Jeollabuk-do (Korea, Republic of); Kim, Tae-Wook, E-mail: twkim@kist.re.kr [Soft Innovative Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, San 101 Eunha-ri, Bongdong-eup, Wanju-gun, Jeollabuk-do (Korea, Republic of)

    2015-01-15

    Highlights: • PS:PCBM-based organic non-volatile memory devices was fabricated using spray printing. • The thickness of the film was controlled by adjusting the concentration of the PS:PCBM solutions. • The roughness of spray-printed films was poorer than that of the spin-coated film. • The minimum thickness of the printed film influenced the memory behavior more than the surface roughness. • The spray printed PS:PCBM showed excellent unipolar switching, reliability, retention, and endurance characteristics. - Abstract: We fabricated polystyrene (PS) and 6-phenyl-C61 butyric acid methyl ester (PCBM) based organic non-volatile memory devices using a spray printing technique. Due to the distinct operational properties of this technique, significant differences were observed in the macro- and microscopic features (e.g., the film quality and surface roughness) of the devices. The thickness of the film was successfully controlled by adjusting the concentration of the PS:PCBM solutions sprayed. Although the roughness of the spray-printed films was poorer than that of the spin-coated film, negligible differences were observed in the basic memory characteristics (e.g., the operation voltage range, turn on and off voltage, retention and endurance). In particular, the printing-based organic memory devices were successfully switched, as exhibited by the on/off ratio greater than two orders of magnitude at 0.3 V read voltage. The resistance state of all of the devices was maintained for more than 10{sup 4} s, indicating their non-volatile characteristics.

  15. Volatile organic compound emissions from arctic vegetation highly responsive to experimental warming

    Science.gov (United States)

    Rinnan, Riikka; Kramshøj, Magnus; Lindwall, Frida; Schollert, Michelle; Svendsen, Sarah H.; Valolahti, Hanna

    2017-04-01

    Arctic areas are experiencing amplified climate warming that proceeds twice as fast as the global temperature increase. The increasing temperature is already causing evident alterations, e.g. changes in the vegetation cover as well as thawing of permafrost. Climate warming and the concomitant biotic and abiotic changes are likely to have strong direct and indirect effects on emission of volatile organic compounds (VOCs) from arctic vegetation. We used long-term field manipulation experiments in the Subarctic, Low Arctic and High Arctic to assess effects of climate change on VOC emissions from vegetation communities. In these experiments, we applied passive warming with open-top chambers alone and in combination with other experimental treatments in well-replicated experimental designs. Volatile emissions were sampled in situ by drawing air from plant enclosures and custom-built chambers into adsorbent cartridges, which were analyzed by thermal desorption and gas chromatography-mass spectrometry in laboratory. Emission increases by a factor of 2-5 were observed under experimental warming by only a few degrees, and the strong response seems universal for dry, mesic and wet ecosystems. In some cases, these vegetation community level responses were partly due to warming-induced increases in the VOC-emitting plant biomass, changes in species composition and the following increase in the amount of leaf litter (Valolahti et al. 2015). In other cases, the responses appeared before any vegetation changes took place (Lindwall et al. 2016) or even despite a decrease in plant biomass (Kramshøj et al. 2016). VOC emissions from arctic ecosystems seem more responsive to experimental warming than other ecosystem processes. We can thus expect large increases in future VOC emissions from this area due to the direct effects of temperature increase, and due to increasing plant biomass and a longer growing season. References Kramshøj M., Vedel-Petersen I., Schollert M., Rinnan

  16. Bacterial Selection from Shrimp Ponds for Degradation of Organic Matters

    Directory of Open Access Journals (Sweden)

    Powtongsook, S.

    2007-01-01

    Full Text Available Accumulation of ammonia, nitrite and hydrogen sulfide in a shrimp pond is generally caused by incomplete degradation of residual organic matters from overfeeding and from organic wastes released by shrimps. The phenomenon affects shrimp growth and survival rate. The objectives of this investigation were to screen for a bacterial strain able to digest organic residues and to evaluate the changes of residues by bacterial activities under natural conditions. The results from this work showed that the isolated strain, Bacillus cereus S1, had the highest protease activity (57.1 U/ml with the presence of glucoamylase and lipase activities (4.5 and 0.13 U/ml, respectively. Under an aseptic condition in 1-L flasks containing seawater with 0.1% shrimp feed, B. cereus S1 degraded organic matters and significantly reduced chemical oxygen demand (COD (70.8%. An amount of ammonia-nitrogen was increased during the first 5 days of incubation due to the degradation of organic compounds in shrimp feed. However, it declined afterward with nitrate-nitrogen increase and unchanged nitrite nitrogen content. Under natural conditions in 10-L glass jars containing seawater with 0.05% shrimp feed and 0.05% sediment, B. cereus S1 and a commercial bacterial product (Inpicin-G could reduce COD (4.5% and 15.8%, respectively and biochemical oxygen demand (BOD (35.1 and 11.4%, respectively. However, similar changes of ammonia-nitrogen, nitrate-nitrogen and nitrite-nitrogen contents in water samples were observed. The results indicate that this selected bacterium could reduce organic compound accumulations on a laboratory scale. In addition, the strain did not produce any enterotoxins compared to a toxin standard. Therefore, the bacterium, Bacillus cereus S1, could be applied to decrease organic matters accumulated in shrimp pond without any harm to shrimps or consumers.

  17. Volatile compounds emission and health risk assessment during composting of organic fraction of municipal solid waste

    DEFF Research Database (Denmark)

    Mustafa, Muhammad Farooq; Liu, Yanjun; Duan, Zhenhan

    2017-01-01

    Degradation of mechanically sorted organic fraction (MSOF) of municipal solid waste in composting facilities is among the major contributors of volatile compounds (VCs) generation and emission, causes nuisance problems and health risks on site as well as in the vicinages. The aim of current study...... was to determine the seasonal (summer and winter) variation and human health risk assessment of VCs in the ambient air of different processing units in MSOF at composting plant in China. Average concentration of VCs was 58.50 and 138.03 mg/m3 in summer and winter respectively. Oxygenated compounds were found...

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

    Energy Technology Data Exchange (ETDEWEB)

    Center for Human Reliability Studies

    2006-06-01

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

  19. Impact of air pressure on volatile organic compound emissions from a carpet

    Institute of Scientific and Technical Information of China (English)

    高鹏; 邓琴琴; LIN; Chao-hsin; 杨旭东

    2009-01-01

    The measurement of volatile organic compound (VOC) emissions from materials is normally conducted under standard environmental conditions, i.e., (23±1) ℃ temperature, (50±5)% relative humidity, and 0.1 MPa pressure. In order to define VOC emissions in non-standard environmental conditions, it is necessary to study the impact of key environmental parameters on emissions. This paper evaluates the impact of air pressure on VOC emissions from an aircraft carpet. The correlation between air pressure and VOC diffusion coefficient is derived, and the emission model is applied to studying the VOC emissions under pressure conditions of less than 0.1 MPa.

  20. Volatile tritiated organic acids in stack effluents and in air surrounding contaminated materials

    Energy Technology Data Exchange (ETDEWEB)

    Belot, Y.; Camus, H.; Marini, T.; Raviart, S. (Institut de Protection et de Surete Nucleaire (France))

    1993-06-01

    A small fraction of the tritium released into the atmosphere from tritium-handling or solid waste storage facilities was shown to be in the form of volatile organic acids. The same compounds were also found, but at a much higher proportion, in the tritium evolved at room temperature from highly contaminated materials placed under air atmospheres. This might be due to the oxidation and labeling of hydrocarbon(s) by mechanisms that are presumably of a radiolytic nature. The new forms could have an impact on operational requirements and waste management strategies within a tritium facility and a fusion reactor hall. Further data are needed to assess the related doses.

  1. Radon, volatile organic compounds and water chemistry in springs around Popocatepetl volcano, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Segovia, N.; Pena, P.; Lopez, M.B.E.; Cisniega, G. [Inst. Nacional de Investigaciones Nucleares, Mexico D.F. (Mexico); Valdes, C.; Armienta, M.A.; Mena, M. [Inst. de Geofisica, UNAM, Ciudad Univ., Mexico D.F. (Mexico)

    2003-07-01

    Popocatepetl volcano is a high-risk active volcano in Central Mexico where the highest population density in the country is settled. Radon in the soil and groundwater together with water chemistry from samples of nearby springs is analysed as a function of the 2002-2003 volcanic activity. Soil radon indicated fluctuations related both to the meteorological and sporadic explosive events. Groundwater radon showed essentially differences in concentration due to the specific characteristics of the studied springs. Water chemistry showed also stability along the monitoring period indicating differences between springs. No anthropogenic pollution from volatile organic compounds was observed. (orig.)

  2. Bioactive and volatile organic compounds in Southern Brazilian blackberry (Rubus Fruticosus fruit cv. Tupy

    Directory of Open Access Journals (Sweden)

    Andressa Carolina Jacques

    2014-09-01

    Full Text Available Blackberry (Rubus fruticosus, cultivar Tupy, an expanding fruit crop in southern Brazil, is greatly appreciated for its flavor and bioactive potential with limited characterization of its metabolite content. The purpose of this study was to characterize the bioactive and volatile organic compound (VOC content of mature blackberry fruit of cultivar Tupy. Gallic acid, (--epicatechin, ferulic acid, and quercetin were the main phenolic compounds found in mature fruit. Among the VOCs identified in 'Tupy' blackberry were important flavor components characteristic of fruit berries, including hydrocarbons, alcohols, aldehydes, ketones, esters, and terpenoids. Some of the VOCs had not been previously found in blackberry, while others have been associated with typical blackberry flavor.

  3. Micro- and Nanostructured Metal Oxide Chemical Sensors for Volatile Organic Compounds

    Science.gov (United States)

    Alim, M. A.; Penn, B. G.; Currie, J. R., Jr.; Batra, A. K.; Aggarwal, M. D.

    2008-01-01

    Aeronautic and space applications warrant the development of chemical sensors which operate in a variety of environments. This technical memorandum incorporates various kinds of chemical sensors and ways to improve their performance. The results of exploratory investigation of the binary composite polycrystalline thick-films such as SnO2-WO3, SnO2-In2O3, SnO2-ZnO for the detection of volatile organic compound (isopropanol) are reported. A short review of the present status of the new types of nanostructured sensors such as nanobelts, nanorods, nanotube, etc. based on metal oxides is presented.

  4. Multiscale Modelling Approach for a Fungal Biofilter Unit for the Hydrophobic Abatement of Volatile Organic Compounds

    DEFF Research Database (Denmark)

    Vergara-Fernández, A.; Rebolledo-Castro, J.; Morales Rodriguez, Ricardo

    2011-01-01

    Currently, biofiltration has become a viable and potential alternative for the treatment of airstreams with low concentrations of hydrophobic volatile organic compounds (VOCs), which can employ to this end, diverse microorganisms (such as, bacteria, fungal or microbial consortia, etc.) growing...... a biofilm. Usually, the design, analysis and scale-up of this kind of units have been mainly done via experimental approach, which can be costly in terms of time and resources. Therefore, the objective of this work is to introduce mathematical model for the prediction and simulation of a fungal biofilter...

  5. Development of a Surface Acoustic Wave Sensor for In-Situ Monitoring of Volatile Organic Compounds

    Directory of Open Access Journals (Sweden)

    Jerome L. Wright

    2003-07-01

    Full Text Available This paper describes the development of a surface-acoustic-wave (SAW sensor that is designed to be operated continuously and in situ to detect volatile organic compounds. A ruggedized stainless-steel package that encases the SAW device and integrated circuit board allows the sensor to be deployed in a variety of media including air, soil, and even water. Polymers were optimized and chosen based on their response to chlorinated aliphatic hydrocarbons (e.g., trichloroethylene, which are common groundwater contaminants. Initial testing indicates that a running-average data-logging algorithm can reduce the noise and increase the sensitivity of the in-situ sensor.

  6. Size-fractionated production and bioavailability of dissolved organic matter

    DEFF Research Database (Denmark)

    Knudsen-Leerbeck, Helle; Bronk, Deborah A.; Markager, Stiig

    Production and bioavailability of dissolved organic matter was quantified on a time scale of two days from size fractions ranging from bacteria to zooplankton in the York River, Virginia. The goal was to find the main contributor to DOM. Batch incubation experiments were labeled with N15-ammonium...... was mainly in the phytoplankton size fraction, which on average contributed 62 % of total particulate nitrogen and 61 % of total particulate carbon. Up to 5 ± 0.4 μmol dissolved organic nitrogen L-1 and 33 ± 6.2 μmol dissolved organic carbon L-1 was produced during the incubation. Bioavailability...... of phytoplankton produced dissolved organic carbon was 12 ± 1 % and higher than in the presence of bacteria, microzooplankton, or copepods (7 ± 3 %). The pattern for bioavailability of dissolved organic nitrogen was less clear and ranged from 4 – 7 %. This study revealed that phytoplankton was the main contributor...

  7. Strong Fluorescent Smart Organogel as a Dual Sensing Material for Volatile Acid and Organic Amine Vapors.

    Science.gov (United States)

    Xue, Pengchong; Yao, Boqi; Wang, Panpan; Gong, Peng; Zhang, Zhenqi; Lu, Ran

    2015-11-23

    An L-phenylalanine derivative (C12PhBPCP) consisting of a strong emission fluorophore with benzoxazole and cyano groups is designed and synthesized to realize dual responses to volatile acid and organic amine vapors. The photophysical properties and self-assembly of the said derivative in the gel phase are also studied. C12PhBPCP can gelate organic solvents and self-assemble into 1 D nanofibers in the gels. UV/Vis absorption spectral results show H-aggregate formation during gelation, which indicates strong exciton coupling between fluorophores. Both wet gel and xerogel emit strong green fluorescence because the cyano group suppresses fluorescence quenching in the self-assemblies. Moreover, the xerogel film with strong green fluorescence can be used as a dual chemosensor for quantitative detection of volatile acid and organic amine vapors with fast response times and low detection limits owing to its large surface area and amplified fluorescence quenching. The detection limits are 796 ppt and 25 ppb for gaseous aniline and trifluoroacetic acid (TFA), respectively.

  8. The role of low-volatility organic compounds in initial particle growth in the atmosphere

    CERN Document Server

    Tröstl, Jasmin; Gordon, Hamish; Heinritzi, Martin; Yan, Chao; Molteni, Ugo; Ahlm, Lars; Frege, Carla; Bianchi, Federico; Wagner, Robert; Simon, Mario; Lehtipalo, Katrianne; Williamson, Christina; Craven, Jill S; Duplissy, Jonathan; Adamov, Alexey; Almeida, Joao; Bernhammer, Anne-Kathrin; Breitenlechner, Martin; Brilke, Sophia; Dias, Antònio; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Fuchs, Claudia; Guida, Roberto; Gysel, Martin; Hansel, Armin; Hoyle, Christopher R; Jokinen, Tuija; Junninen, Heikki; Kangasluoma, Juha; Keskinen, Helmi; Kim, Jaeseok; Krapf, Manuel; Kürten, Andreas; Laaksonen, Ari; Lawler, Michael; Leiminger, Markus; Mathot, Serge; Möhler, Ottmar; Nieminen, Tuomo; Onnela, Antti; Petäjä, Tuukka; Piel, Felix M; Miettinen, Pasi; Rissanen, Matti P; Rondo, Linda; Sarnela, Nina; Schobesberger, Siegfried; Sengupta, Kamalika; Sipilä, Mikko; Smith, James; Steiner, Gerhard; Tomè, Antònio; Virtanen, Annele; Wagner, Andrea C; Weingartner, Ernest; Wimmer, Daniela; Winkler, Paul M; Ye, Penglin; Carslaw, Kenneth S; Curtius, Joachim; Dommen, Josef; Kirkby, Jasper; Kulmala, Markku; Riipinen, Ilona; Worsnop, Douglas R; Donahue, Neil M; Baltensperger, Urs

    2016-01-01

    About half of present-day cloud condensation nuclei originate from atmospheric nucleation, frequently appearing as a burst of new particles near midday. Atmospheric observations show that the growth rate of new particles often accelerates when the diameter of the particles is between one and ten nanometres. In this critical size range, new particles are most likely to be lost by coagulation with pre-existing particles, thereby failing to form new cloud condensation nuclei that are typically 50 to 100 nanometres across. Sulfuric acid vapour is often involved in nucleation but is too scarce to explain most subsequent growth, leaving organic vapours as the most plausible alternative, at least in the planetary boundary layer. Although recent studies predict that low-volatility organic vapours contribute during initial growth, direct evidence has been lacking. The accelerating growth may result from increased photolytic production of condensable organic species in the afternoon, and the presence of a possible Kelv...

  9. Removal of Indoor Volatile Organic Compounds via Photocatalytic Oxidation: A Short Review and Prospect

    Directory of Open Access Journals (Sweden)

    Yu Huang

    2016-01-01

    Full Text Available Volatile organic compounds (VOCs are ubiquitous in indoor environments. Inhalation of VOCs can cause irritation, difficulty breathing, and nausea, and damage the central nervous system as well as other organs. Formaldehyde is a particularly important VOC as it is even a carcinogen. Removal of VOCs is thus critical to control indoor air quality (IAQ. Photocatalytic oxidation has demonstrated feasibility to remove toxic VOCs and formaldehyde from indoor environments. The technique is highly-chemical stable, inexpensive, non-toxic, and capable of removing a wide variety of organics under light irradiation. In this paper, we review and summarize the traditional air cleaning methods and current photocatalytic oxidation approaches in both of VOCs and formaldehyde degradation in indoor environments. Influencing factors such as temperature, relative humidity, deactivation and reactivations of the photocatalyst are discussed. Aspects of the application of the photocatalytic technique to improve the IAQ are suggested.

  10. Removal of Indoor Volatile Organic Compounds via Photocatalytic Oxidation: A Short Review and Prospect.

    Science.gov (United States)

    Huang, Yu; Ho, Steven Sai Hang; Lu, Yanfeng; Niu, Ruiyuan; Xu, Lifeng; Cao, Junji; Lee, Shuncheng

    2016-01-04

    Volatile organic compounds (VOCs) are ubiquitous in indoor environments. Inhalation of VOCs can cause irritation, difficulty breathing, and nausea, and damage the central nervous system as well as other organs. Formaldehyde is a particularly important VOC as it is even a carcinogen. Removal of VOCs is thus critical to control indoor air quality (IAQ). Photocatalytic oxidation has demonstrated feasibility to remove toxic VOCs and formaldehyde from indoor environments. The technique is highly-chemical stable, inexpensive, non-toxic, and capable of removing a wide variety of organics under light irradiation. In this paper, we review and summarize the traditional air cleaning methods and current photocatalytic oxidation approaches in both of VOCs and formaldehyde degradation in indoor environments. Influencing factors such as temperature, relative humidity, deactivation and reactivations of the photocatalyst are discussed. Aspects of the application of the photocatalytic technique to improve the IAQ are suggested.

  11. Shrinkage Behavior of Polystyrene-based Foam Molded Parts Depending on Volatile Matter Content and Other Factors

    Science.gov (United States)

    Ghafafian, Carineh

    Polymer foam materials play a large role in the modern world. Expanded polystyrene (EPS) bead foam is a lightweight, low density, and good thermal and acoustic insulating material whose properties make it attractive for a number of applications, especially as building insulation. However, EPS also experiences post-molding shrinkage; it shrinks dimensionally from its molded size after processing. This means parts must be stored in warehouses until they are considered stable by the industry standard, DIN EN 1603. This often takes 11--18 weeks and is thus very timely and expensive. This study aims to decrease the post-molding shrinkage time of EPS foam by understanding the mechanisms of shrinkage behavior. Samples were split into two groups based on their amount of initial volatile matter content and storage conditions, then compared to a control group. Based on thermogravimetric analysis and gas chromatography with mass spectrometry, the volatile matter content and composition was found to not be the sole contributor to EPS foam dimensional stability. Residual stress testing was done with the hole drilling method and Raman spectroscopy. As this type of testing has not been done with polymer foams before, the aim was to see if either method could reliably produce residual stress values. Both methods measured residual stress values with unknown accuracy. All samples stored at a higher temperature (60°C) reached dimensional stability by the end of this study. Thus, air diffusion into EPS foam, encouraged by the high temperature storage, was found to play a significant role in post-molding shrinkage.

  12. [Characteristics and environmental significance of soil dissolved organic matter].

    Science.gov (United States)

    Zhao, Jinsong; Zhang, Xudong; Yuan, Xing; Wang, Jing

    2003-01-01

    Soil is a complex ecosystem with multi-interface. A numerous studies on soil dissolved organic matter (DOM) were carried out, and proved that DOM was one of the most active chemical components in the environment. Increasing attention has been paid on the study of soil DOM, especially in recent years, and the study has become an interdisciplinary focus in the fields of soil science, ecology, and environmental science due to the important roles of DOM in the biogeochemical cycles of carbon, nitrogen, phosphorus, sulfur, etc. In addition, DOM has significant effects on pedogenesis, growth and metabolism of soil microorganisms, decomposition and transformation of soil organic matter, and transport of pollutants in soils. The recent literatures about extraction methods, origin, composition, contents and controlling factors, bioavailability, and environmental significance of DOM were therefore reviewed, and future research aspects on this topic were also proposed.

  13. Characteristics of volatile compounds removal in biogas slurry of pig manure by ozone oxidation and organic solvents extraction

    Institute of Scientific and Technical Information of China (English)

    Yujun Wang; Lianshuang Feng; Xiaosong Zhao; Xiulan Ma; Jingmin Yang; Huiqing Liu; Sen Dou

    2013-01-01

    Biogas slurry is not suitable for liquid fertilizer due to its high amounts of volatile materials being of complicated composition and peculiar smell.In order to remove volatiles from biogas slurry efficiently,the dynamic headspace and gas chromatography-mass spectrometry were used to clear the composition of volatiles.Nitrogen stripping and superfluous ozone were also used to remove volatiles from biogas slurry.The results showed that there were 21 kinds of volatile compounds in the biogas slurry,including sulfur compounds,organic amines,benzene,halogen generation of hydrocarbons and alkanes,some of which had strong peculiar smell.The volatile compounds in biogas slurry can be removed with the rate of 53.0% by nitrogen stripping and with rate of 81.7% by the oxidization and stripping of the superfluous ozone.On this basis,the removal rate of the volatile compounds reached 99.2%by chloroform and n-hexane extraction,and almost all of odor was eliminated.The contents of some dissolved organic compounds decreased obviously and however main plant nutrients had no significant change in the biogas slurry after being treated.

  14. Cool oxygen plasma oxidation of the organic matter of coal

    Energy Technology Data Exchange (ETDEWEB)

    Korobetskii, I.A.; Nazimov, S.A.; Romanchuk, V.V. [COAL-C Ltd., Kemerovo (Russian Federation)

    1997-12-31

    Oxidation of the sapropelitic coals has been carried out by cool oxygen plasma. The changes in concentration of oxygen- and hydrogen-containing groups of organic matter were observed by photoacoustic FTIR-spectroscopy during the cool oxygen plasma oxidation (COPO). The accumulation of oxygen-containing bands, such as C-O and O-H, during COPO was shown. The complete elimination of aromatic and aliphatic structure occurred in first two hours of oxidation. (orig.)

  15. The Biogeochemistry of Chromophoric Dissolved Organic Matter in Coastal Waters

    Science.gov (United States)

    2016-06-07

    The Biogeochemistry of Chromophoric Dissolved Organic Matter in Coastal Waters Robert F. Chen Environmental , Coastal and Ocean Sciences University of...properties to governing physical processes in high energy environments such as coastal seas. In addition, large spatial coverage over a wide range of...optical measurements of CDOM. In order to reliably predict the important photochemical, biological, and chemical processes governing CDOM, and hence its

  16. Simultaneous Microwave Extraction and Separation of Volatile and Non-Volatile Organic Compounds of Boldo Leaves. From Lab to Industrial Scale

    Directory of Open Access Journals (Sweden)

    Loïc Petigny

    2014-04-01

    Full Text Available Microwave extraction and separation has been used to increase the concentration of the extract compared to the conventional method with the same solid/liquid ratio, reducing extraction time and separate at the same time Volatile Organic Compounds (VOC from non-Volatile Organic Compounds (NVOC of boldo leaves. As preliminary study, a response surface method has been used to optimize the extraction of soluble material and the separation of VOC from the plant in laboratory scale. The results from the statistical analysis revealed that the optimized conditions were: microwave power 200 W, extraction time 56 min and solid liquid ratio of 7.5% of plants in water. Lab scale optimized microwave method is compared to conventional distillation, and requires a power/mass ratio of 0.4 W/g of water engaged. This power/mass ratio is kept in order to upscale from lab to pilot plant.

  17. Thermodynamics of uranium/organic matter interactions in hydrothermal systems

    Science.gov (United States)

    Richard, L.

    2003-04-01

    Organic matter is commonly encountered in and around uranium and other ore deposits, which raises the question of the role played by organic compounds in the formation of these deposits (Landais and Gize, 1997). One of the best known examples is the observation of uraninite crystals entrapped within solid bitumens in the Oklo natural reactors. This observation led Nagy et al. (1991) to propose that a liquid, aliphatic-rich bitumen may have acted as a reductant to precipitate uraninite from hydrothermal solutions according to the reaction VIUO2+2(aq)+H_2O(l)=IVUO2(c)+2H^+(aq)+0.5 O2(g). The liquid bitumen was simultaneously oxidized into a polyaromatic solid, which may be represented by the reaction 2.7n- C20H42(l) + 17.85 O2(g) = C54H42(c)+35.7 H_2O(l) where n-C20H42(l) denotes n-eicosane present in the liquid bitumen, and C54H42(c) represents an idealized polyaromatic solid. Recent advances in theoretical organic geochemistry made it possible to generate a comprehensive thermodynamic database for hundreds of crystalline, liquid, gas and aqueous organic compounds of geochemical interest (Shock and Helgeson, 1990; Shock, 1995; Amend and Helgeson, 1997; Helgeson et al., 1998; Richard and Helgeson, 1998; Richard, 2001), which can be used together with thermodynamic properties for uranium-bearing minerals and aqueous species (Grenthe et al., 1992; Shock et al., 1997) to characterize uranium/organic matter interactions in hydrothermal systems as a function of temperature, pressure, oxygen fugacity, and organic matter composition. Activity-fO_2 diagrams have been constructed at a series of temperatures and pressures to investigate possible genetic relationships between uranium mineralizations and solid bitumens of various compositions.

  18. Xiphinema americanum as Affected by Soil Organic Matter and Porosity.

    Science.gov (United States)

    Ponchillia, P E

    1972-07-01

    The effects of four soil types, soil porosity, particle size, and organic matter were tested on survival and migration of Xiphinema americanum. Survival and migration were significantly greater in silt loam than in clay loam and silty clay soils. Nematode numbers were significantly greater in softs planted with soybeans than in fallow softs. Nematode survival was greatest at the higher of two pore space levels in four softs. Migration of X. americanum through soft particle size fractions of 75-150, 150-250, 250-500, 500-700, and 700-1,000 mu was significantly greater in the middle three fractions, with the least occurring in the smallest fraction. Additions of muck to silt loam and loamy sand soils resulted in reductions in survival and migration of the nematode. The fulvic acid fraction of muck, extracted with sodium hydroxide, had a deleterious effect on nematode activity. I conclude that soils with small amounts of air-filled pore space, extremes in pore size, or high organic matter content are deleterious to the migration and survival of X. americanum, and that a naturally occurring toxin affecting this species may be present in native soft organic matter.

  19. Temperature sensitivity of organic-matter decay in tidal marshes

    Science.gov (United States)

    Kirwan, M. L.; Guntenspergen, G. R.; Langley, J. A.

    2014-09-01

    Approximately half of marine carbon sequestration takes place in coastal wetlands, including tidal marshes, where organic matter contributes to soil elevation and ecosystem persistence in the face of sea-level rise. The long-term viability of marshes and their carbon pools depends, in part, on how the balance between productivity and decay responds to climate change. Here, we report the sensitivity of labile soil organic-matter decay in tidal marshes to seasonal and latitudinal variations in temperature measured over a 3-year period. We find a moderate increase in decay rate at warmer temperatures (3-6% per °C, Q10 = 1.3-1.5). Despite the profound differences between microbial metabolism in wetlands and uplands, our results indicate a strong conservation of temperature sensitivity. Moreover, simple comparisons with organic-matter production suggest that elevated atmospheric CO2 and warmer temperatures will accelerate carbon accumulation in marsh soils, and potentially enhance their ability to survive sea-level rise.

  20. Matrix protected organic matter in a river dominated margin: A possible mechanism to sequester terrestrial organic matter?

    Science.gov (United States)

    Mead, Ralph N.; Goñi, Miguel A.

    2008-06-01

    The provenance of organic matter in surface sediments from the northern Gulf of Mexico was investigated by analyzing the compositions of lipid biomarkers ( n-alkanes, fatty acids, sterols) liberated after a series of chemical treatments designed to remove different organo-mineral matrix associations (i.e. freely extractable, base-hydrolyzable, unhydrolyzable). Bulk analyses of the organic matter (carbon content, carbon:nitrogen ratios, stable and radiocarbon isotopic analyses) were also performed on the intact sediments and their non-hydrolyzable, demineralized residue. We found recognizable lipids from distinct sources, including terrestrial vascular plants, bacteria and marine algae and zooplankton, within each of the isolated fractions. Based on the lipid signatures and bulk compositions, the organic matter within the unhydrolyzable fractions appeared to be the most diagenetically altered, was the oldest in age, and had the highest abundance of terrigenous lipids. In contrast, the base-hydrolyzable fraction was the most diagentically unaltered, had the youngest ages and was most enriched in N and marine lipids. Our results indicate that fresh, autochthonous organic matter is the most important contributor to base-hydrolyzable lipids, whereas highly altered allochthonous sources appear to be predominant source of unhydrolyzable lipids in the surface sediments from the Atchafalaya River shelf. Overall, the lipid biomarker signatures of intact sediments were biased towards the autochthonous source because many of the organic compounds indicative of degraded, terrigenous sources were protected from extraction and saponification by organo-mineral matrices. It is only after these protective matrices were removed by treatment with HCl and HF that these compounds became evident.

  1. Development of a fast GC/MS-system for airborne measurements of Volatile Organic Compounds

    Science.gov (United States)

    Wenk, Ann-Kathrin; Wegener, Robert; Hofzumahaus, Andreas; Wahner, Andreas

    2010-05-01

    Volatile Organic Compounds (VOC) determine the radical chemistry of the atmosphere. They can serve both as sources, or sinks for radicals. Mass spectrometry linked to gas chromatography (GC/MS) is a widespread technique in environmental analysis since it can be used to separate and analyze any compound which can be evaporated and pass the analytical column with very high precision and a good sensitivity. The use of special chromatographic phases and long capillary columns enables the quantification of a wide range of compounds with little interference from other sample constituents. An in situ GC/MS consists in principle of three compartments, 1) a preconcentration unit where the sample is extracted from the air, focussed onto a small volume and volatilized, 2) a chromatographic system where the analytes are separated on the analytical column and 3) a mass spectrometer where the compounds are ionized and detected. VOC have to be preconcentrated due to their low concentration level and in order to get enough sensitivity for analysis. The aim of this project was to develop an in situ GC/MS system to analyze volatile Nonmethane Hydrocarbons (NMHC) and Oxygenated Volatile Organic Compounds (OVOC) for the High Altitude and LOng Range Research Aircraft (HALO). In contrast to other analytical instruments a GC/MS works discontinuously. The preconcentration unit is either heated up when the compounds are volatilized or cooled down when substances are adsorbed. The same is true for the GC oven. It is heated up when the compounds are separated or it is cooled down to be ready for the next injection. On a system with a single GC oven, these processes will inevitably lengthen the whole analytical procedure. To speed up the analytical process the GC/MS system described here was equipped with two GC ovens and two adsorption units. While the components are adsorbed in one adsorption unit, in the other unit the components are desorbed and transferred to the GC unit. The second GC

  2. Determination of fine particulate semi-volatile organic material at three eastern U.S. sampling sites.

    Science.gov (United States)

    Warner, K S; Eatough, D J; Stockburger, L

    2001-09-01

    Correct assessment of fine particulate carbonaceous material as a function of particle size is, in part, dependent on the determination of semi-volatile compounds, which can be lost from particles during sampling. This study gives results obtained for the collection of fine particulate carbonaceous material at three eastern U.S. sampling sites [Philadelphia, PA; Shenandoah National Park, VA; and Research Triangle Park (RTP), NC] using diffusion denuder technology. The diffusion denuder samplers allow for the determination of fine particulate organic material with no artifacts, due to the loss of semi-volatile organic particulate compounds, or collection of gas-phase organic compounds by the quartz filter during sampling. The results show that an average of 41, 43, and 59% of fine particulate organic material was lost as volatilized semi-volatile organic material during collection of particles on a filter at Philadelphia, RTP, and Shenandoah, respectively. The particle size distribution of carbonaceous material retained by a filter and lost from a filter during sampling was obtained for the samples collected at Philadelphia and Shenandoah. The carbonaceous material retained by the particles during sampling was found predominantly in particles smaller than 0.4 microm in aerodynamic diameter. In contrast, the semi-volatile organic material lost from the particles during sampling had a mass median diameter of approximately 0.5 microm.

  3. Plutonium Immobilization and Mobilization by Soil Organic Matter

    Energy Technology Data Exchange (ETDEWEB)

    Santschi, Peter H. [Texas A& M University, Galveston, TX (United States); Schwehr, Kathleen A. [Texas A& M University, Galveston, TX (United States); Xu, Chen [Texas A& M University, Galveston, TX (United States); Athon, Matthew [Texas A& M University, Galveston, TX (United States); Ho, Yi-Fang [Texas A& M University, Galveston, TX (United States); Hatcher, Patrick G. [Old Dominion Univ., Norfolk, VA (United States); Didonato, Nicole [Old Dominion Univ., Norfolk, VA (United States); Kaplan, Daniel I. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-08

    The human and environmental risks associated with Pu disposal, remediation, and nuclear accidents scenarios stems mainly from the very long half-lives of several of its isotopes. The SRS, holding one-third of the nation’s Pu inventory, has a long-term stewardship commitment to investigation of Pu behavior in the groundwater and downgradient vast wetlands. Pu is believed to be essentially immobile due to its low solubility and high particle reactivity to mineral phase or natural organic matter (NOM). For example, in sediments collected from a region of SRS, close to a wetland and a groundwater plume, 239,240Pu concentrations suggest immobilization by NOM compounds, as Pu correlate with NOM contents. Micro-SXRF data indicate, however, that Pu does not correlate with Fe. However, previous studies reported Pu can be transported several kilometers in surface water systems, in the form of a colloidal organic matter carrier, through wind/water interactions. The role of NOM in both immobilizing or re-mobilizing Pu thus has been demonstrated. Our results indicate that more Pu (IV) than (V) was bound to soil colloidal organic matter (COM), amended at far-field concentrations. Contrary to expectations, the presence of NOM in the F-Area soil did not enhance Pu fixation to the organic-rich soil, when compared to the organic-poor soil or the mineral phase from the same soil source, due to the formation of COM-bound Pu. Most importantly, Pu uptake by organic-rich soil decreased with increasing pH because more NOM in the colloidal size desorbed from the particulate fraction at elevated pH, resulting in greater amounts of Pu associated with the COM fraction. This is in contrast to previous observations with low-NOM sediments or minerals, which showed increased Pu uptake with increasing pH levels. This demonstrates that despite Pu immobilization by NOM, COM can convert Pu into a more mobile form. Sediment Pu concentrations in the SRS F-Area wetland were correlated to total organic

  4. Production of fluorescent dissolved organic matter in Arctic Ocean sediments

    Science.gov (United States)

    Chen, Meilian; Kim, Ji-Hoon; Nam, Seung-Il; Niessen, Frank; Hong, Wei-Li; Kang, Moo-Hee; Hur, Jin

    2016-12-01

    Little is known about the production of fluorescent dissolved organic matter (FDOM) in the anoxic oceanic sediments. In this study, sediment pore waters were sampled from four different sites in the Chukchi-East Siberian Seas area to examine the bulk dissolved organic carbon (DOC) and their optical properties. The production of FDOM, coupled with the increase of nutrients, was observed above the sulfate-methane-transition-zone (SMTZ). The presence of FDOM was concurrent with sulfate reduction and increased alkalinity (R2 > 0.96, p  0.95, p oceans.

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

    Science.gov (United States)

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

    2013-10-01

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

  6. Relating CCN activity, volatility, and droplet growth kinetics of β-caryophyllene secondary organic aerosol

    Directory of Open Access Journals (Sweden)

    A. Asa-Awuku

    2009-02-01

    Full Text Available This study investigates the droplet formation characteristics of secondary organic aerosol (SOA formed during the ozonolysis of sesquiterpene β-caryophyllene (with and without hydroxyl radicals present. Emphasis is placed on understanding the role of semi-volatile material on Cloud Condensation Nucleus (CCN activity and droplet growth kinetics. Aging of β-caryophyllene SOA significantly affects all CCN-relevant properties measured throughout the experiments. Using a thermodenuder and two CCN instruments, we find that CCN activity is a strong function of temperature (activation diameter at ~0.6% supersaturation: 100±10 nm at 20°C and 130±10 nm at 35°C, suggesting that the hygroscopic fraction of the SOA is volatile. The water-soluble organic carbon (WSOC is extracted from the SOA and characterized with Köhler Theory Analysis (KTA; the results suggest that the WSOC is composed of low molecular weight (<200 g mol−1 slightly surface-active material that constitute 5–15% of the SOA mass. These properties are similar to the water-soluble fraction of monoterpene SOA, suggesting that predictive understanding of SOA CCN activity requires knowledge of the WSOC fraction but not its exact speciation. Droplet growth kinetics of the CCN are found to be strongly anticorrelated with WSOC fraction, suggesting that the insoluble material in the SOA forms a kinetic barrier that delays droplet growth. Overall, volatilization effects can increase activation diameters by 30%, and depress droplet growth rate by a factor of two; these results may have important implications for the droplet formation characteristics of SOA, and the atmospheric relevance of CCN measurements carried out at temperatures different from ambient.

  7. Model studies of volatile diesel exhaust particle formation: are organic vapours involved in nucleation and growth?

    Science.gov (United States)

    Pirjola, L.; Karl, M.; Rönkkö, T.; Arnold, F.

    2015-09-01

    A high concentration of volatile nucleation mode particles (NUP) formed in the atmosphere when the exhaust cools and dilutes has hazardous health effects and it impairs the visibility in urban areas. Nucleation mechanisms in diesel exhaust are only poorly understood. We performed model studies using two sectional aerosol dynamics process models AEROFOR and MAFOR on the formation of particles in the exhaust of a diesel engine, equipped with an oxidative after-treatment system and running with low fuel sulfur content (FSC) fuel, under laboratory sampling conditions where the dilution system mimics real-world conditions. Different nucleation mechanisms were tested. Based on the measured gaseous sulfuric acid (GSA) and non-volatile core and soot particle number concentrations of the raw exhaust, the model simulations showed that the best agreement between model predictions and measurements in terms of particle number size distribution was obtained by barrier-free heteromolecular homogeneous nucleation between the GSA and a semi-volatile organic vapour combined with the homogeneous nucleation of GSA alone. Major growth of the particles was predicted to occur due to the similar organic vapour at concentrations of (1-2) × 1012 cm-3. The pre-existing core and soot mode concentrations had an opposite trend on the NUP formation, and the maximum NUP formation was predicted if a diesel particle filter (DPF) was used. On the other hand, the model predicted that the NUP formation ceased if the GSA concentration in the raw exhaust was less than 1010 cm-3, which was the case when biofuel was used.

  8. Volatile organic compounds from native potato-associated Pseudomonas as potential anti-oomycete agents.

    Directory of Open Access Journals (Sweden)

    Mout eDeVrieze

    2015-11-01

    Full Text Available The plant kingdom represents a prominent biodiversity island for microbes that associate with the below- or aboveground organs of vegetal species. Both the root and the leaf represent interfaces where dynamic biological interactions influence plant life. Beside well-studied communication strategies based on soluble compounds and protein effectors, bacteria were recently shown to interact both with host plants and other microbial species through the emissions of volatile organic compounds (VOCs. Focusing on the potato late blight-causing agent Phytophthora infestans, this work addresses the potential role of the bacterial volatilome in suppressing plant diseases. In a previous study, we isolated and identified a large collection of strains with anti-Phytophthora potential from both the phyllosphere and the rhizosphere of potato. Here we report the characterization and quantification of their emissions of biogenic volatiles, comparing 16 Pseudomonas strains differing in i origin of isolation (phyllosphere vs. rhizosphere, ii in vitro inhibition of P. infestans growth and sporulation behavior, and iii protective effects against late blight on potato leaf discs. We systematically tested the pharmacological inhibitory activity of core and strain-specific single compounds against P. infestans mycelial growth and sporangial behavior in order to identify key effective candidate molecules present in the complex natural VOCs blends. We envisage the plant bacterial microbiome as a reservoir for functional VOCs and establish the basis for finding the primary enzymatic toolset that enables the production of active components of the volatile bouquet in plant-associated bacteria. Comprehension of these functional interspecies interactions will open perspectives for the sustainable control of plant diseases in forthcoming agriculture.

  9. Photocatalytic Removal of Microbiological Consortium and Organic Matter in Greywater

    Directory of Open Access Journals (Sweden)

    Nazmiye Cemre Birben

    2016-06-01

    Full Text Available This study aimed to investigate TiO2 photocatalytic degradation of synthetically-prepared greywater samples with differing compositional contents of organic matter (OM, anion concentration, and microbiological consortium. Treatment efficiency was followed through removal of organic matter content in terms of dissolved organic carbon (DOC, specific spectroscopic parameters, and bacterial inactivation. Photocatalytic degradation kinetics were expressed by pseudo first-order kinetic modeling. The best DOC removal rates were attained for greywater samples containing OM with lower molecular size fractions. In addition, either enhancing or reducing the effect of common anions as radical scavengers were observed depending on the composition and concentration of variables in the greywater matrix. Moreover, possibility of a photocatalytic disinfection process was found to be of a bacteria type specific in OM-loaded synthetic greywater samples. Photocatalytic destruction of fecal streptococci required longer irradiation periods under all conditions. Bacterial removal rates were found to be in the order of total coliform > fecal coliform > fecal streptococci, for low organic load greywater, and fecal coliform > total coliform > fecal streptococci, for high organic load greywater.

  10. Car indoor air pollution by volatile organic compounds and aldehydes in Japan

    Directory of Open Access Journals (Sweden)

    Kouichi Tatsu

    2016-06-01

    Full Text Available Fifty-five organic substances including volatile organic compounds (VOCs and aldehydes present in indoor air were measured from 24 car cabins in Japan. A screening-level risk assessment was also performed. Acetaldehyde (3.81–36.0 μg/m3, formaldehyde (3.26–26.7 μg/m3, n-tetradecane (below the method quantification limit (organic compounds originated from the car interior materials. Total volatile organic compound (TVOC concentrations in 14 car cabins (58% of all car cabins exceeded the advisable values established by the Ministry of Health, Labour and Welfare of Japan (400 μg/m3. The highest TVOC concentration (1136 μg/m3 was found in a new car (only one month since its purchase date. Nevertheless, TVOC concentrations exceeded the advisable value even for cars purchased over 10 years ago. Hazard quotients (HQs for formaldehyde obtained using measured median and highest concentrations in both exposure scenarios for occupational use (residential time in a car cabin was assumed to be 8 h were higher than that expected, a threshold indicative of potential adverse effects. Under the same exposure scenarios, HQ values for all other organic compounds remained below this threshold.

  11. Radiocarbon Dating of Soil Organic Matter Fractions in Andosols in Northern Ecuador

    NARCIS (Netherlands)

    Tonneijck, Femke H.; Plicht, Johannes van der; Jansen, Boris; Verstraten, Jacobus M.; Hooghiemstra, Henry

    2006-01-01

    Volcanic ash soils (Andosols) may offer great opportunities for paleoecological studies, as suggested by their characteristic accumulation of organic matter (OM). However, understanding of the chronostratigraphy of soil organic matter (SOM) is required. Therefore, radiocarbon dating of SOM is

  12. Air monitoring of volatile organic compounds at relevant receptors during hydraulic fracturing operations in Washington County, Pennsylvania.

    Science.gov (United States)

    Maskrey, Joshua R; Insley, Allison L; Hynds, Erin S; Panko, Julie M

    2016-07-01

    A 3-month air monitoring study was conducted in Washington County, Pennsylvania, at the request of local community members regarding the potential risks resulting from air emissions of pollutants related to hydraulic fracturing operations. Continuous air monitoring for total volatile organic compounds was performed at two sampling sites, including a school and a residence, located within 900 m of a hydraulic fracturing well pad that had been drilled prior to the study. Intermittent 24-hour air samples for 62 individual volatile organic compounds were also collected. The ambient air at both sites was monitored during four distinct periods of unconventional natural gas extraction activity: an inactive period prior to fracturing operations, during fracturing operations, during flaring operations, and during another inactive period after operations. The results of the continuous monitoring during fracturing and flaring sampling periods for total volatile organic compounds were similar to the results obtained during inactive periods. Total volatile organic compound 24-hour average concentrations ranged between 0.16 and 80 ppb during all sampling periods. Several individual volatile compounds were detected in the 24-hour samples, but they were consistent with background atmospheric levels measured previously at nearby sampling sites and in other areas in Washington County. Furthermore, a basic yet conservative screening level evaluation demonstrated that the detected volatile organic compounds were well below health-protective levels. The primary finding of this study was that the operation of a hydraulic fracturing well pad in Washington County did not substantially affect local air concentrations of total and individual volatile organic compounds.

  13. Characterization of fine organic particulate matter from Chinese cooking

    Institute of Scientific and Technical Information of China (English)

    HE Ling-yan; HU Min; WANG Li; HUANG Xiao-feng; ZHANG Yuan-hang

    2004-01-01

    PM2.5 samples were collected by a three-stage cascade impactor at two kinds of Chinese restaurants to characterize fine organic particulate matter from Chinese cooking sources. Major individual organic compounds have been quantified by GC/MS, including series of alkanes, n-alkanoic acids, n-alkanals, alkan-2-ones and PAHs.Alkanes and ketones make up a significant fraction of particle-phase organic compounds, ranging from C11 to C26,and C9 to C19, respectively. In addition, other organic compound classes have been identified, such as alkanols,esters, furans, lactones, amides, and nitriles. The mass concentrations of fine particles, alkanes, n-alkanoic acids and PAHs in air emitted from the Uigur style cooking are hundreds times higher than ambient PM2.5 in Beijing.

  14. The Venus flytrap attracts insects by the release of volatile organic compounds.

    Science.gov (United States)

    Kreuzwieser, Jürgen; Scheerer, Ursel; Kruse, Jörg; Burzlaff, Tim; Honsel, Anne; Alfarraj, Saleh; Georgiev, Plamen; Schnitzler, Jörg-Peter; Ghirardo, Andrea; Kreuzer, Ines; Hedrich, Rainer; Rennenberg, Heinz

    2014-02-01

    Does Dionaea muscipula, the Venus flytrap, use a particular mechanism to attract animal prey? This question was raised by Charles Darwin 140 years ago, but it remains unanswered. This study tested the hypothesis that Dionaea releases volatile organic compounds (VOCs) to allure prey insects. For this purpose, olfactory choice bioassays were performed to elucidate if Dionaea attracts Drosophila melanogaster. The VOCs emitted by the plant were further analysed by GC-MS and proton transfer reaction-mass spectrometry (PTR-MS). The bioassays documented that Drosophila was strongly attracted by the carnivorous plant. Over 60 VOCs, including terpenes, benzenoids, and aliphatics, were emitted by Dionaea, predominantly in the light. This work further tested whether attraction of animal prey is affected by the nutritional status of the plant. For this purpose, Dionaea plants were fed with insect biomass to improve plant N status. However, although such feeding altered the VOC emission pattern by reducing terpene release, the attraction of Drosophila was not affected. From these results it is concluded that Dionaea attracts insects on the basis of food smell mimicry because the scent released has strong similarity to the bouquet of fruits and plant flowers. Such a volatile blend is emitted to attract insects searching for food to visit the deadly capture organ of the Venus flytrap.

  15. Distribution of Total Volatile Organic Compounds at taxi drivers in Tehran

    Directory of Open Access Journals (Sweden)

    Seyyed Mohammad Javad Golhosseini

    2015-06-01

    Full Text Available Air pollution is currently the most serious environmental health threat worldwide. Volatile Organic Compounds (VOC are considered as the main effective factors in causing air pollution. Vehicles are among the major sources which emit these compounds, so it seems that automobiles’ microenvironment is one of the places where people are exposed to high concentration of VOC. Evaluating the exposure amount of Total Volatile Organic Compounds (TVOC can indeed be used as an indicator to estimate the amount of exposure to every individual VOC. This study was conducted on the concentration of TVOC inside Tehran taxies for a period of one year. For this purpose, a real time instrument equipped with photo-ionization detector (PID was used. Consequently, the highest and the lowest measured TVOC in taxies equaled 3.33 ppm and 0.72 ppm, respectively. In addition, the arithmetic mean of TVOC concentration was 1.77±0.53 ppm inside the examined taxies. In this study, the parameters like measurement time, climate and vehicle conditions were found to have significant effect on the amount of exposure to TVOC.

  16. The impact of plants on the reduction of volatile organic compounds in a small space.

    Science.gov (United States)

    Song, Jeong-Eun; Kim, Yong-Shik; Sohn, Jang-Yeul

    2007-11-01

    This study aims at examining the reduction of indoor air contaminants by plants placed in an indoor space. Field measurements were performed using Aglaonema brevispathum, Pachira aquatica, and Ficus benjamiana, which were verified as air-purifying plants by NASA. Three conditions for the amount of plants and positions were used in two separate rooms whose dimensions are identical. The concentration of Volatile Organic Compounds (VOCs) was monitored three hours after the plants were placed and three days after the plants were placed. The variations of concentration of Benzene, Toluene, Etylbenzene, and Xylene (BTEX), as well as Formaldehyde, which are all known as the major elements of Volatile Organic Compounds were monitored. The amount of reduction in concentration of Toluene and Formaldehyde was monitored 3 hours and 3 days after the plants were placed in the space. The reduction in the concentration of Benzene, Toluene, Etylbenzene, Xylene, and Formaldehyde was significantly greater when plants were present. When plants were placed near a window, the reduction of concentration was greater. The more plants were used, the more a reduction of indoor air contaminants occurred. The effect of reducing the concentration of air contaminants increased when the amount of plants increased, and when the plants were placed in sunny area. The concentration of Toluene was reduced by 45.6 microg/m(3) when 10% of the model space was occupied by Aglaonema brevispathum.

  17. Native Fluorescence Detection Methods and Detectors for Naphthalene and/or Other Volatile Organic Compound Vapors

    Science.gov (United States)

    Hug, William F. (Inventor); Bhartia, Rohit (Inventor); Reid, Ray D. (Inventor); Lane, Arthur L. (Inventor)

    2014-01-01

    Naphthalene, benzene, toluene, xylene, and other volatile organic compounds have been identified as serious health hazards. This is especially true for personnel working with JP8 jet fuel and other fuels containing naphthalene as well as other hazardous volatile organic compounds (VOCs). Embodiments of the invention are directed to methods and apparatus for near-real-time in-situ detection and accumulated dose measurement of exposure to naphthalene vapor and other hazardous gaseous VOCs. The methods and apparatus employ excitation of fluorophors native or endogenous to compounds of interest using light sources emitting in the ultraviolet below 300 nm and measurement of native fluorescence emissions in distinct wavebands above the excitation wavelength. The apparatus of some embodiments are cell-phone-sized sensor/dosimeter "badges" to be worn by personnel potentially exposed to naphthalene or other hazardous VOCs. The badge sensor of some embodiments provides both real time detection and data logging of exposure to naphthalene or other VOCs of interest from which both instantaneous and accumulated dose can be determined. The badges employ a new native fluorescence based detection method to identify and differentiate VOCs. The particular focus of some embodiments are the detection and identification of naphthalene while other embodiments are directed to detection and identification of other VOCs like aromatic hydrocarbons such as benzene, toluene, and xylene.

  18. Levels and source apportionment of volatile organic compounds in southwestern area of Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Rodolfo Sosa, E. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico); Humberto Bravo, A. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico)], E-mail: hbravo@servidor.unam.mx; Violeta Mugica, A. [Universidad Autonoma Metropolitana, Azcapotzalco, D.F. (Mexico); Pablo Sanchez, A. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico); Emma Bueno, L. [Centro Nacional de Investigacion y Capacitacion Ambiental, Instituto Nacional de Ecologia (Mexico); Krupa, Sagar [Department of Plant Pathology, University of Minnesota, St. Paul, MN 55108 (United States)

    2009-03-15

    Thirteen volatile organic compounds (VOCs) were quantified at three sites in southwestern Mexico City from July 2000 to February 2001. High concentrations of different VOCs were found at a Gasoline refueling station (GS), a Condominium area (CA), and at University Center for Atmospheric Sciences (CAS). The most abundant VOCs at CA and CAS were propane, n-butane, toluene, acetylene and pentane. In comparison, at GS the most abundant were toluene, pentane, propane, n-butane, and acetylene. Benzene, a known carcinogenic compound had average levels of 28, 35 and 250 ppbC at CAS, CA, and GS respectively. The main contributing sources of the measured VOCs at CA and CAS were the handling and management of LP (Liquid Propane) gas, vehicle exhaust, asphalt works, and use of solvents. At GS almost all of the VOCs came from vehicle exhaust and fuel evaporation, although components of LP gas were also present. Based on the overall results possible abatement strategies are discussed. - Volatile organic compounds were quantified in order to perform their source apportionment in southwestern area of Mexico City.

  19. Volatile Organic Analyzer (VOA) in 2006: Repair, Revalidation, and Restart of Elektron Event

    Science.gov (United States)

    Limero, Thomas

    2007-01-01

    The Volatile Organic Analyzer (VOA) was launched to the International Space Station (ISS) in August 2001 and was the first instrument to provide near real-time measurement of volatile organic compounds in a spacecraft atmosphere. The VOA performed an analysis of the ISS air approximately twice a month for most of its operation through May 2003. This intermittent operation, caused by a software interface issue with the ISS communication bus, slowed the validation of the VOA. However, operational validation was completed in 2003 when analysis of air samples collected in grab sample containers (GSCs) compared favorably with simultaneous VOA runs (1). The VOA has two channels that provide redundant function, albeit at slightly reduced performance, when only one channel is operating (2). Most target compounds can be detected on both channels. In January 2003, the VOA identified a malfunction in the channel 2 preconcentrator and it shut down that channel. The anomaly profile suggested that a fuse might have failed, but the root cause could not be determined. In May 2003, channel 1 was shut down when the detector s elevated temperature could not longer be maintained. Since both VOA channels were now deactivated, VOA operations ended until an in-flight repair could be planned and executed. This paper describes the process to repair the VOA and to revalidate it for operations, and then an account is given of the VOA s contribution following a contingency event on ISS.

  20. Metal-organic molecular device for non-volatile memory storage

    Energy Technology Data Exchange (ETDEWEB)

    Radha, B., E-mail: radha.boya@manchester.ac.uk, E-mail: kulkarni@jncasr.ac.in; Sagade, Abhay A.; Kulkarni, G. U., E-mail: radha.boya@manchester.ac.uk, E-mail: kulkarni@jncasr.ac.in [Chemistry and Physics of Materials Unit and DST Unit on Nanoscience, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore 560064 (India)

    2014-08-25

    Non-volatile memory devices have been of immense research interest for their use in active memory storage in powered off-state of electronic chips. In literature, various molecules and metal compounds have been investigated in this regard. Molecular memory devices are particularly attractive as they offer the ease of storing multiple memory states in a unique way and also represent ubiquitous choice for miniaturized devices. However, molecules are fragile and thus the device breakdown at nominal voltages during repeated cycles hinders their practical applicability. Here, in this report, a synergetic combination of an organic molecule and an inorganic metal, i.e., a metal-organic complex, namely, palladium hexadecylthiolate is investigated for memory device characteristics. Palladium hexadecylthiolate following partial thermolysis is converted to a molecular nanocomposite of Pd(II), Pd(0), and long chain hydrocarbons, which is shown to exhibit non-volatile memory characteristics with exceptional stability and retention. The devices are all solution-processed and the memory action stems from filament formation across the pre-formed cracks in the nanocomposite film.